Research progress on the stress-strain index of Corvis ST / 国际眼科杂志(Guoji Yanke Zazhi)

Corneal visualization Scheimpflug technology(Corvis ST)is currently the most commonly used clinical device for assessing in vivo corneal biomechanics. The new parameter stress-strain index(SSI)has been a hot topic of clinical research in recent years, which not only directly reflect corneal biomaterial stiffness, but also closely correlates with the progression of certain diseases. SSI was generated based on the predictions of corneal behavior using finite element(FE)numerical modeling to simulate the effects of intraocular pressure and Corvis ST jets. The SSI algorithm does not change with central corneal thickness(CCT), intraocular pressure, or biomechanically corrected intraocular pressure(BIOP), but it is clearly associated with altered collagen fibres in the corneosclera. The principles of SSI, the relationship between age and SSI, the relationship between axial length and SSI, the relationship between myopia and SSI, and the application of SSI are summarized and concluded.

FVB/NJ strain as a mouse model for cutaneous leishmaniasis by Leishmania (L.) amazonensis

BACKGROUND Leishmaniases encompass a spectrum of neglected diseases caused by parasites of the genus Leishmania, grouped in two forms: tegumentary and visceral leishmaniasis. OBJECTIVES In this study, we propose Friend Virus B NIH Jackson (FVB/NJ) mouse strain as a new experimental model of infection with Leishmania (Leishmania) amazonensis, the second most prevalent agent of tegumentary leishmaniasis in Brazil. METHODS AND FINDINGS We performed in vitro infections of FVB/NJ macrophages and compared them with BALB/c macrophages, showing that BALB/c cells have higher infection percentages and a higher number of amastigotes/cell. Phagocytosis assays indicated that BALB/c and FVB/NJ macrophages have similar capacity to uptake parasites after 5 min incubations. We also investigated promastigotes' resistance to sera from FVB/NJ and BALB/c and observed no difference between the two sera, even though FVB/NJ has a deficiency in complement components. Finally, we subcutaneously infected FVB/NJ and BALB/c mice with 2 × 106 parasites expressing luciferase. Analysis of lesion development for 12 weeks showed that FVB/NJ and BALB/c mice have similar lesion profiles and parasite burdens. MAIN CONCLUSIONS This work characterises for the first time the FVB/NJ mouse as a new model for tegumentary leishmaniasis caused by Leishmania (L.) amazonensis.

Age-related variations in corneal stress-strain index in the Indian population

Purpose: To report age?related variations in corneal stress–strain index (SSI) in healthy Indians. Methods: It was a retrospective study where healthy Indian individuals aged between 11 and 70 years who had undergone corneal biomechanics assessment using Corvis ST between January 2017 and December 2021 were enrolled. Composite corneal biomechanical parameters and corneal SSI were abstracted from Corvis ST and compared across different age groups using one?way analysis of variance (ANOVA). Also, Pearson’s correlation was used to evaluate the association between age and SSI. Results: Nine hundred and thirty?six eyes of 936 patients with ages between 11 and 77 years with mean ± SD intraocular pressure (IOP) and pachymetry of 16.52 ± 2.10 mmHg and 541.13 ± 26.39 ?s, respectively. Composite corneal biomechanical parameters such as deformation amplitude ratio max at 1 mm (P < 0.001) and 2 mm (P < 0.001), biomechanically corrected IOP (P = 0.004), stiffness parameter at A1 (P < 0.001, Corvis biomechanical index (P < 0.018), and SSI (P < 0.001) were found to be significantly different as a function of age group. We noted a statistically significant positive association of SSI with age (P < 0.001), spherical equivalent refractive error (P < 0.001), and IOP (P < 0.001) and a significant negative association with anterior corneal astigmatism (P < 0.001) and Anterior chamber depth (ACD) (P < 0.001). Also, SSI was positively associated with SPA1 and bIOP, whereas negatively associated with integrated radius, max inverse radius, and Max Deformation amplitude (DA) ratio at 1 mm and 2 mm. Conclusion: We noted a positive association of corneal SSI with age in normal healthy Indian eyes. This information could be helpful for future corneal biomechanical research.

Assessment of short forms of recurrent atrial extra systoles by echocardiography with left atrial strain in ambulatory patients without organic cardiopathy / Evaluación de formas cortas de extrasístoles auriculares recurrentes mediante ecocardiografía con deformación auricular izquierda en pacientes ambulatorios sin cardiopatía orgánica

Abstract Aim: To analyse the potential usefulness and clinical relevance of the assessment by echocardiography with left atrial strain, based on the myocardial atrial deformation curves with speckle-tracking velocity vector imaging (VVI), in the analysis of short-form recurrent atrial extra systoles in ambulatory patients not suffering from organic cardiopathy. Methods: We designed a descriptive, prospective, and observational study including 270 patients between the ages of 18 and 75 assessed during an outpatient cardiology consultation attended due to palpitations over a period of two years. Using ambulatory electrocardiographic monitoring, we selected cases with short forms of repetitive atrial extrasystole, isolated or recurrentatrial fibrillation and a control group formed by those patients without repetitive ectopia. All patients underwent a thorough echocardiographic study during their first cardiological visit. Results: The analysis of the dynamic curves segmental deformation generated after an atrial extrasystole can reveal different points of origin of the extrasystole and detect specific anatomical alterations in the interatrial conduction at the level of the Bachmann's fascicle showing different models of electro anatomical activation possibly involved in the appearance of repetitive forms. Higher values of dyssynchrony between the septal and lateral wall and elongation in the time of interatrial electromechanical conduction could also be related to the existence of repetitive ectopic beats. Conclusions: Our ambulatory study employing the left atrial longitudinal strain, particularly in its segmental analysis, provides new insights into its the usefulness and potential clinical relevance.

Resumen Objetivo: Analizar la utilidad y relevancia clínica de la evaluación mediante ecocardiografía basada en las curvas de deformación auricular miocárdica con imágenes vectoriales de velocidad (VVI) de speckle-tracking, en el análisis de las extrasístoles auriculares recurrentes de corta duración en pacientes ambulatorios sin cardiopatía orgánica. Métodos: Se diseñó un estudio descriptivo, prospectivo y observacional que incluyó a 270 pacientes de entre 18 y 75 años evaluados durante una consulta externa de cardiología a la que acudieron por palpitaciones durante un periodo de dos años. Mediante el uso de monitorización electrocardiográfica ambulatoria, se seleccionaron casos con formas cortas de extrasistolia auricular repetitiva, fibrilación auricular aislada o repetitiva y un grupo control formado por aquellos pacientes sin ectopia repetitiva. Todos los pacientes se sometieron a un estudio ecocardiográfico exhaustivo durante su primera visita cardiológica. Resultados: El análisis de las curvas dinámicas de deformación segmentaria generadas tras un extrasístole auricular diferentes modelos de activación electroanatómica posiblemente implicados en la aparición de formas repetitivas. Valores mayores de disincronía entre la pared septal y lateral y el alargamiento en el tiempo de conducción electromecánica intraauricular pudieran también relacionarse con la existencia de latidos ectópicos repetitivos. Conclusiones: Nuestro estudio ambulatorio empleando la deformación longitudinal auricular izquierda, particularmente en su análisis segmentario, proporciona nuevas perspectivas sobre su utilidad y potencial relevancia clínica.

The 20/20/20 rule: Practicing pattern and associations with asthenopic symptoms

Purpose: The present work style and lifestyle have increased the digital device use. Therefore, an increase in digital eyestrain is to be expected. We undertook a survey during coronavirus disease 2019 (COVID?19) pandemic to investigate the practice of 20/20/20 rule and its association with digital device use and asthenopic symptoms. While this rule is commonly advised, little is known about its validity. Methods: An online survey form was disseminated through social media and emails. The questions for eye?related symptoms were similar to the convergence insufficiency symptom survey (CISS). Participants with age ?5 years were included, with parents completing the survey for children (?16 years). Results: A total of 432 participants (mean ± standard deviation [SD]: 26.06 ± 13.92 years) were enrolled, of which 125 responses were for children. The 20/20/20 rule was practiced only by 34% of the participants either regularly (n = 38) or occasionally (n = 109). Those who had complaints of burning sensation and headache tended to practice this rule. Among adult participants, more females (47%) practiced this rule when compared to males (23%). Also, adult females significantly (P = 0.04) had more symptoms score when compared to males. In children, no such gender difference was found. Conclusion: Only one?third of participants practice the 20/20/20 rule at least occasionally. More number of adult females being symptomatic and practicing in greater number could be due to higher prevalence of dry eye condition in females. While the symptom of burning sensation could be related to dry eye, that of headache could be related to refractive error or binocular vision dysfunctions

A study on correlation of computer vision syndrome and dry eye disease and knowledge regarding its associated factors amongst health professionals

Purpose: To know the magnitude and determinants of dry eye syndrome among health professionals and to study the correlation of computer vision syndrome with dry eye disease. Methods: In total, 501 participants took part in the study, which included history followed by baseline ocular examination, which included visual acuity using Snellen’s chart and anterior segment examination using a slit lamp. Later, a questionnaire was administered to health professionals to be filled out for analysis in the present study. Results: The symptoms reported occasionally were burning (35.5%), itching (34.5%), foreign body sensation 22.6%, and tearing (35.3%). The majority of participants used mobiles and laptops (56.1%) as a display. Also, 53.3% of participants have heard about dry eye syndrome, and the source of information was from friends and doctors in 17% of participants. One hundred twenty?one participants (24.2%) had taken the consultation for ocular symptoms. Eighty?six participants had mild, 29 participants had moderate, and 6 participants had severe dry eye disease, respectively. Conclusion: The pandemic effect, and the drastic shift of educational media from the classroom to the digital platform have increased the use of mobiles, laptops, or other digital pads for learning. This has increased the risk for health professionals.

Subcostal right ventricular free wall strain in patients with pulmonary hypertension / Strain subcostal de la pared libre del ventriculo derecho en pacientes con hipertensión pulmonar

Abstract Right ventricular longitudinal strain (RVLS) is frequently used as a measure of right ventricular systolic function. Abnormal RV strain is associated with poor prognosis in patients with pulmonary hyper tension (PH); however, the measure is not always easy to obtain in patients with poor apical acoustic windows. Objective: This study aims to analyze the RVLS and determine if there is a difference when measured from the apical and subcostal views. Methods: In this cross-sectional study, we analyzed 22 adult outpatients (≥ 18 years old), 81% female, mean age 49.9 ± 17.3 years, with a diagnosis of PH using right heart catheterization, followed from January 2016 to January 2020. Results: RVLS measured in the RV free wall from the apical views was -15% (-19% to -10%) and subcostal views -14.5% (-18% to -11%) were highly correlated (Person's r = 0.969, p < 0.0001). Segment by segment analysis did not show significant differences either: basal four-chamber vs. sub costal view was -16.5% (-21% to -11%) vs. -15.5% (-20% to -11%), p = 0.99, mid four-chamber view vs. subcotal view was -16.5% (-21% to -12%) vs. -16.5% (-20% to -11%), p = 0.87, apical four-chamber view vs. subcostal view was -12% (-18% to -8%) vs. -13.5% (-19% to -10%), p = 0.93. Conclusion: Subcostal RVLS free wall is a feasible and accurate alternative to conventional RVLS free wall from the apical view in patients with pulmonary hypertension and could be useful in patients with poor acoustic apical four-chamber windows.

Resumen El strain longitudinal del ventrículo derecho (SLVD) permite medir la función sistólica del ventrículo derecho (VD). La disminución del strain (deformación) del VD se asocia con mal pronóstico en pacientes con hipertensión pulmonar (HP), pero no siempre es fácil de obtener en pacientes con mala ventana acústica apical. Objetivo: Este estudio tiene como objetivo analizar el SLVD y determinar si las vistas apical y subcostal son comparables. Métodos: En este estudio transversal, se incluyeron 22 pacientes adultos ambulatorios (≥18 años), 81% mujeres, edad promedio 49.9 ± 17.3 años, con diagnóstico de HP mediante cateterismo cardíaco derecho, seguidos desde enero de 2016 hasta enero de 2020. Se midió la deformación de la pared libre del ventrículo derecho desde las vistas de cuatro cámaras apical y cuatro cámaras subcostal. Resultados: El SLVD medido en la pared libre del VD desde la vista apical fue -15% (-19% a -10%) vs. -14.5% (-18% a -11%) cuando se midió desde la vista subcostal (p = 0,99). El análisis segmento por s egmento tampoco mostró diferencias significativas: el segmento basal apical vs. subcostal fue -16.5% (-21% a -11%) vs. -15.5% (-20% a -11%), p = 0.99, el segmento medio apical vs. la vista subcotal fue -16.5% (-21% a -12%) vs. a -16.5% (-20% a -11%), p = 0.87, el segmento apical vs. la vista subcostal fue -12% (-18% a -8%) frente a -13.5% (-19% a -10%), p = 0.93. Conclusión: En pacientes con HP, el SLVD obtenido en la pared libre subcostal es una alternativa útil en los casos con ventana acústica apical subóptima.

Value of the strain ratio in the differential diagnosis of intraocular tumors by elastosonography: A retrospective case-control study

Purpose: To examine the role of the strain ratio in elastosonography for the differential diagnosis of common intraocular tumors such as choroidal melanoma, choroidal hemangioma, choroidal metastatic carcinoma, and retinoblastoma. Methods: This study included patients suffering from intraocular space?occupying lesions and who visited Beijing Tongren Eye Center of Beijing Tongren Hospital affiliated to Capital Medical University from June 2016 to March 2020. All patients underwent a physical examination, fundus examination with mydriasis, color Doppler ultrasonography, elastosonography, magnetic resonance imaging (MRI), and fundus angiography within 1 week. All patients were grouped as choroidal melanoma, choroidal metastatic carcinoma, retinoblastoma, choroidal hemangioma, and optic disk melanocytoma. A receiver operating characteristic (ROC) curve analysis was performed to assess the strain ratio for diagnosing malignant intraocular tumors. Results: A total of 155 patients (161 eyes) were recruited. The strain ratios measured were 39.59 ± 15.92 for choroidal melanoma, 36.85 ± 13.64 for choroidal metastatic carcinoma, 38.93 ± 17.27 for retinoblastoma, 13.42 ± 10.93 for choroidal hemangioma, and 3.84 ± 1.32 for optic disk melanocytoma. The strain ratios of the three malignant lesions were significantly higher than those of the two benign lesions (all P < 0.001). The area under the ROC curve was 0.95 ± 0.028. The optimal cutoff point was 22.67, with 85.7% sensitivity and 96.4% specificity. Conclusion: There were significant differences in elasticity between the malignant and benign intraocular tumors. The strain ratio using elastosonography could serve as an important auxiliary examination to distinguish between benign and malignant intraocular tumors

Phenotypic and molecular characterization of Staphylococcus aureus isolates conducted in nares of psoriatic patients attending a public hospital in Argentina / Caracterización fenotípica y molecular de aislamientos de Staphylococcus aureus portados en narinas de pacientes con psoriasis que concurren a un hospital público en Argentina

Abstract Although Staphylococcus aureus increases its relative abundance in psoriasis when compared with the microbiome of healthy subjects, it is not the most important microorganism underlying this disease. However, there is scant data on the role and molecular features of S. aureus strains in psoriasis; therefore, the aim of this study was to evaluate nasal carriage of this microorganism, its phenotypic and molecular characteristics as well as the impact of host factors on its carriage in psoriatic patients. The presence of S. aureus was analyzed in nasal swabs from 46 healthy volunteers and 50 psoriatic patients by conventional microbiology techniques. Nasal carriage of S. aureus was higher in psoriatic patients than in the control group (37.24% vs 22.98%, respectively), being associated to sex (male), age (adults) and severity of the disease (more frequent in moderate and severe cases). Determination of antibiotic resistance detected 12% of (-lactam resistant isolates, with variable accompanying resistance to macrolides, aminoglycosides and fluoroquinolones. No resistance to rifampicin, vancomycin, mupirocin or trimethoprim/sulfamethoxazole was found. A preliminary molecular characterization of the isolates was performed by PCR amplification of virulence genes. Molecular characterization of the strains did not reveal a predominant strain in psoriatic patients. Although we established host factors related to increased carriage of S. aureus in psoriatic patients, we could not establish the predominance of one type of strain. Genomic and transcriptomic analysis of the isolated strains would be necessary to address this point.

Resumen A pesar de que Staphylococcus aureus incrementa su abundancia relativa en la psoriasis cuando se compara con el microbioma de personas sanas, no es el microorganismo más importante subyacente a la enfermedad. Sin embargo, existen pocos datos sobre el papel y las características moleculares de las cepas de S. aureus en pacientes con psoriasis. Nuestro objetivo fue evaluar la portación nasal de este microorganismo, sus características fenotípicas y moleculares, y el impacto de factores del hospedador sobre dicha portación en estos pacientes. Se analizó la presencia de S. aureus en hisopados nasales de 46 voluntarios sanos y 50 pacientes con psoriasis mediante técnicas microbiológicas convencionales. Se encontró mayor portación en pacientes con psoriasis que en el grupo control (37,24% vs. 22,98%, respectivamente) y esta estuvo asociada al sexo (masculino), la edad (adultos) y la gravedad de la enfermedad (más frecuente en casos moderados a graves). El 12% de los aislamientos de S. aureus mostraron resistencia a betalactámicos, con resistencia acompañante a macrólidos, aminoglucósidos y fluoroquinolonas en grado variable. No se encontró resistencia a rifampicina, vancomicina, mupirocina o trimetroprima/sulfametoxazol. Se realizó una caracterización molecular preliminar de los aislamientos por amplificación de genes de virulencia mediante PCR. Si bien se identificaron factores relacionados con el hospedador que incrementan la portación nasal de S. aureus en pacientes con psoriasis, la caracterización molecular de las cepas no reveló ninguna característica genotípica predominante asociada a esta afección. Se necesitan más estudios genómicos y transcriptómicos para profundizar en esta caracterización.

Strain echocardiography in predicting LV dysfunction in RV apical pacing

Right ventricular (RV) pacing is associated with a reduction in left ventricular (LV) systolic function, thought to be mediated by pacing-induced ventricular dyssynchrony. The prevalence of heart failure after RV pacing is reported to range from 31±3%. We studied 60 subjects with high-grade atrioventricular block and Complete Heart Block (CHB) scheduled to undergo right ventricular apical pacing. 2D echocardiography was done at baseline, 1 month and 12 months. Pacing-induced cardiomyopathy was defined as a reduction in LVEF to <45%. Strain was evaluated off-line from digitally stored images using all advanced software package (cardiac wall motion quantification (CMQ); Toshiba Medical Systems). Longitudinal strain for individual myocardial segments was measured from the apical four-chamber, two-chamber and long axis views (16 segment AHA/ASE model). None had LV dysfunction at baseline based on 2D and strain echo imaging. Subsequently 18 patients were detected to develop low GLS score (less than -14.5) at 1 month. On subsequent follow up at 1 year, all 18 patients developed LV dysfunction on 2D Echocardiography. Thus Strain imaging with GLS score helped in early detection of LV dysfunction in RV apical pacing subjects. Pacing-induced cardiomyopathy had significant association with high grade AV block with pacemaker dependency. It had no significant associations with other comorbidities like diabetes, hypertension, ischemic heart disease or with the type of medication intake. However there was a statistically significant association with heart failure

Significant production of vanillin and in vitro amplification of ech gene in local bacterial isolates

Abstract Vanillin is the major component which is responsible for flavor and aroma of vanilla extract and is produced by 3 ways: natural extraction from vanilla plant, chemical synthesis and from microbial transformation. Current research was aimed to study bacterial production of vanillin from native natural sources including sewage and soil from industrial areas. The main objective was vanillin bio-production by isolating bacteria from these native sources. Also to adapt methodologies to improve vanillin production by optimized fermentation media and growth conditions. 47 soil and 13 sewage samples were collected from different industrial regions of Lahore, Gujranwala, Faisalabad and Kasur. 67.7% bacterial isolates produced vanillin and 32.3% were non-producers. From these 279 producers, 4 bacterial isolates selected as significant producers were; A3, A4, A7 and A10. These isolates were identified by ribotyping as A3 Pseudomonas fluorescence (KF408302), A4 Enterococcus faecium (KT356807), A7 Alcaligenes faecalis (MW422815) and A10 Bacillus subtilis (KT962919). Vanillin producers were further tested for improved production of vanillin and were grown in different fermentation media under optimized growth conditions for enhanced production of vanillin. The fermentation media (FM) were; clove oil based, rice bran waste (residues oil) based, wheat bran based and modified isoeugenol based. In FM5, FM21, FM22, FM23, FM24, FM30, FM31, FM32, FM34, FM35, FM36, and FM37, the selected 4 bacterial strains produced significant amounts of vanillin. A10 B. subtilis produced maximum amount of vanillin. This strain produced 17.3 g/L vanillin in FM36. Cost of this fermentation medium 36 was 131.5 rupees/L. This fermentation medium was modified isoeugenol based medium with 1% of isoeugenol and 2.5 g/L soybean meal. ech gene was amplified in A3 P. fluorescence using ech specific primers. As vanillin use as flavor has increased tremendously, the bioproduction of vanillin must be focused.

Resumo A vanilina é o principal componente responsável pelo sabor e aroma do extrato de baunilha e é produzida de três formas: extração natural da planta da baunilha, síntese química e transformação microbiana. A pesquisa atual teve como objetivo estudar a produção bacteriana de vanilina a partir de fontes naturais nativas, incluindo esgoto e solo de áreas industriais. O objetivo principal era a bioprodução de vanilina por meio do isolamento de bactérias dessas fontes nativas. Também para adaptar metodologias para melhorar a produção de vanilina por meio de fermentação otimizada e condições de crescimento. Foram coletadas 47 amostras de solo e 13 de esgoto de diferentes regiões industriais de Lahore, Gujranwala, Faisalabad e Kasur; 67,7% dos isolados bacterianos produziram vanilina e 32,3% eram não produtores. Desses 279 produtores, 4 isolados bacterianos selecionados como produtores significativos foram: A3, A4, A7 e A10. Esses isolados foram identificados por ribotipagem como fluorescência A3 Pseudomonas (KF408302), A4 Enterococcus faecium (KT356807), A7 Alcaligenes faecalis (MW422815) e A10 Bacillus subtilis (KT962919). Os produtores de vanilina foram posteriormente testados para produção aprimorada de vanilina e foram cultivados em diferentes meios de fermentação sob condições de crescimento otimizadas para produção aprimorada de vanilina. Os meios de fermentação (FM) foram: à base de óleo de cravo, à base de resíduos de farelo de arroz (resíduos de óleo), à base de farelo de trigo e à base de isoeugenol modificado. Em FM5, FM21, FM22, FM23, FM24, FM30, FM31, FM32, FM34, FM35, FM36 e FM37, as 4 cepas bacterianas selecionadas produziram quantidades significativas de vanilina. A10 B. subtilis produziu quantidade máxima de vanilina. Essa cepa produziu 17,3 g / L de vanilina em FM36. O custo desse meio de fermentação 36 foi de 131,5 rúpias / L. Esse meio de fermentação foi um meio à base de isoeugenol modificado com 1% de isoeugenol e 2,5 g / L de farelo de soja. O gene ech foi amplificado em A3 P. fluorescence usando primers específicos para ech. Como o uso da vanilina como sabor aumentou tremendamente, a bioprodução da vanilina deve ser focada.

Significant production of vanillin and in vitro amplification of ech gene in local bacterial isolates / Produção significativa de vanilina e amplificação in vitro do gene ech em isolados bacterianos locais

Abstract Vanillin is the major component which is responsible for flavor and aroma of vanilla extract and is produced by 3 ways: natural extraction from vanilla plant, chemical synthesis and from microbial transformation. Current research was aimed to study bacterial production of vanillin from native natural sources including sewage and soil from industrial areas. The main objective was vanillin bio-production by isolating bacteria from these native sources. Also to adapt methodologies to improve vanillin production by optimized fermentation media and growth conditions. 47 soil and 13 sewage samples were collected from different industrial regions of Lahore, Gujranwala, Faisalabad and Kasur. 67.7% bacterial isolates produced vanillin and 32.3% were non-producers. From these 279 producers, 4 bacterial isolates selected as significant producers were; A3, A4, A7 and A10. These isolates were identified by ribotyping as A3 Pseudomonas fluorescence (KF408302), A4 Enterococcus faecium (KT356807), A7 Alcaligenes faecalis (MW422815) and A10 Bacillus subtilis (KT962919). Vanillin producers were further tested for improved production of vanillin and were grown in different fermentation media under optimized growth conditions for enhanced production of vanillin. The fermentation media (FM) were; clove oil based, rice bran waste (residues oil) based, wheat bran based and modified isoeugenol based. In FM5, FM21, FM22, FM23, FM24, FM30, FM31, FM32, FM34, FM35, FM36, and FM37, the selected 4 bacterial strains produced significant amounts of vanillin. A10 B. subtilis produced maximum amount of vanillin. This strain produced 17.3 g/L vanillin in FM36. Cost of this fermentation medium 36 was 131.5 rupees/L. This fermentation medium was modified isoeugenol based medium with 1% of isoeugenol and 2.5 g/L soybean meal. ech gene was amplified in A3 P. fluorescence using ech specific primers. As vanillin use as flavor has increased tremendously, the bioproduction of vanillin must be focused.

Resumo A vanilina é o principal componente responsável pelo sabor e aroma do extrato de baunilha e é produzida de três formas: extração natural da planta da baunilha, síntese química e transformação microbiana. A pesquisa atual teve como objetivo estudar a produção bacteriana de vanilina a partir de fontes naturais nativas, incluindo esgoto e solo de áreas industriais. O objetivo principal era a bioprodução de vanilina por meio do isolamento de bactérias dessas fontes nativas. Também para adaptar metodologias para melhorar a produção de vanilina por meio de fermentação otimizada e condições de crescimento. Foram coletadas 47 amostras de solo e 13 de esgoto de diferentes regiões industriais de Lahore, Gujranwala, Faisalabad e Kasur; 67,7% dos isolados bacterianos produziram vanilina e 32,3% eram não produtores. Desses 279 produtores, 4 isolados bacterianos selecionados como produtores significativos foram: A3, A4, A7 e A10. Esses isolados foram identificados por ribotipagem como fluorescência A3 Pseudomonas (KF408302), A4 Enterococcus faecium (KT356807), A7 Alcaligenes faecalis (MW422815) e A10 Bacillus subtilis (KT962919). Os produtores de vanilina foram posteriormente testados para produção aprimorada de vanilina e foram cultivados em diferentes meios de fermentação sob condições de crescimento otimizadas para produção aprimorada de vanilina. Os meios de fermentação (FM) foram: à base de óleo de cravo, à base de resíduos de farelo de arroz (resíduos de óleo), à base de farelo de trigo e à base de isoeugenol modificado. Em FM5, FM21, FM22, FM23, FM24, FM30, FM31, FM32, FM34, FM35, FM36 e FM37, as 4 cepas bacterianas selecionadas produziram quantidades significativas de vanilina. A10 B. subtilis produziu quantidade máxima de vanilina. Essa cepa produziu 17,3 g / L de vanilina em FM36. O custo desse meio de fermentação 36 foi de 131,5 rúpias / L. Esse meio de fermentação foi um meio à base de isoeugenol modificado com 1% de isoeugenol e 2,5 g / L de farelo de soja. O gene ech foi amplificado em A3 P. fluorescence usando primers específicos para ech. Como o uso da vanilina como sabor aumentou tremendamente, a bioprodução da vanilina deve ser focada.

Evaluation of right ventricular function using two-dimensional speckle tracking echocardiography and analysis of the risk factors for right ventricular dysfunction in patients with silicosis / 中华劳动卫生职业病杂志

Objective: To evaluate the right ventricular function using two-dimensional speckle tracking echocardiography (2-D STE) and analyze the associated risk factors of right ventricular dysfunction in patients with silicosis. Methods: All 104 patients with silicosis treated in the Department of Occupational Medicine and Toxicology in Beijing Chao-Yang Hospital, Capital Medical University from May 2021 to September 2022 were enrolled in this study in October 2022. The clinical information of patients such as general data, arterial blood gas analysis and pulmonary function test were collected. The right ventricular function of patients was evaluated by 2-D STE-derived right ventricular free wall longitudinal strain (RVFWLS) and conventional echocardiographic-derived parameters, including right ventricular fractional area change (RVFAC), tricuspid annular plane systolic excursion (TAPSE) and doppler tissue imaging-derived tricuspid lateral annular systolic velocity (S'), respectively. Based on their RVFWLS, the patients were divided into right ventricular dysfunction group and normal right ventricular function group. Risk factors for right ventricular dysfunction in patients with silicosis were analyzed using binary logistic regression analysis. Results: A total of 104 silicosis patients were enrolled, with aneverage age (65.52±11.18) years old, among whom including 57 cases diagnosed with stage Ⅰ/Ⅱ silicosis and 47 cases diagnosed with stage Ⅲ silicosis. 26 (25.00%) patients concurrent right ventricular dysfunction. The abnormal rates of RVFAC, TAPSE and S' in patients were 16.35% (17 cases), 21.15% (22 cases) and 6.73% (7 cases), respectively. The RVFAC and TAPSE in right ventricular dysfunction group were lower than those in normal right ventricular function group, and the incidence of pulmonary arterial systolic pressure ≥36 mmHg was higher than that in normal right ventricular function group (P<0.05). Logistic regression analysis showed that arterial partial pressure of oxygen (OR=0.932, 95%CI: 0.885-0.981, P=0.007) was the protective factor, and the forced expiratory volume in 1 second (FEV(1)) /forced vital capacity (FVC) ratio<70% (OR=5.484, 95%CI: 1.049-28.662, P=0.044) and stage Ⅲ silicosis (OR=6.343, 95%CI: 1.698-23.697, P=0.007) were the risk factors for silicosis patients concurrent right ventricular dysfunction. Conclusion: The incidence of right ventricular dysfunction is higher in patients with stage Ⅲ silicosis than that in patients with stage Ⅰ/Ⅱ silicosis. Using 2-D STE can help the early detection of silicosis with right ventricular dysfunction. Hypoxemia, airflow limitation and the stage Ⅲ silicosis are the risk factors for silicosis patients concurrent right ventricular dysfunction.

Genome sequencing and analysis of BCG strain for vaccine production in China / 上海预防医学

ObjectiveTo conduct the sequencing and preliminarily analysis of the whole genome of BCG Shanghai D2PB302 strain （hereinafter referred to as BCG Shanghai D2 strain）， which has been used exclusively for the vaccine production in China. MethodsThe DNA of of BCG Shanghai D2 strain （D2-JIA12-1） was extracted， and the whole genome was sequenced by Pacbio-RS Ⅱ. The sequence data was assembled by Smrtlink and polished with the illumina data. Genes， tRNA and rRNA were predicted based on the sequence data. The functional annotation of predicted genes was performed through BLASTP. The IVE-TB antigen gene and MTBVAC were selected as the target sequences to be compared with Mycobacterium tuberculosis H37Rv （NC_000962.3）. ResultsThe sequence length of BCG Shanghai D2 strain was 4 045 232 bp， and the GC content was 65.66%. A total of 4 259 protein-encoding genes were predicted， with an average gene size of 933 bp. 2 476 genes had biological functions and others were hypothetical proteins.144 virulence genes were obtained by comparing with the VFDB. There were 29 type Ⅶ secretion system genes and 10 PE/PPE protein family genes. ConclusionThe whole genome sequence of BCG Shanghai D2 strain is clarified. It lays a broad foundation for subsequent detection of the stability of major antigen genes.

Screening,identification,enzymatic characteristics and optimization of fermentation condition of a high alkaline xylanase-producing strain / 中国生物制品学杂志

@#ObjectiveTo screen a high alkaline xylanase-producing strain,subject to molecular identification and characterization of enzymatic property,and optimize its fermentation condition.MethodsThe farmland soil samples from Shanxi,Henan and Zhejiang Provinces were collected aseptically,from which the high xylanase-producing strains were screened by enrichment culture,isolation and identification of 16S r DNA,and determined for enzymatic properties.The carbon source(xylan,lactose,soluble starch,sucrose,bran and glucose),nitrogen source[ammonium oxalate,peptone,yeast powder,(NH_4)_2SO_4,NH_4Cl,Na NO_3,urea,beef extract,bean powder,KNO_3,(NH_4)_2HPO_4or random mixture of two of peptone,yeast powder,beef extract,(NH_4)_2HPO_4and bean powder],metal ion[CuCl_2,MgCl_2,ZnCl_2,Al_2(SO_4)_3,CoCl_2,MnCl_2,AgNO_3,NaCl,CaCl_2,FeCl_2,BaCl_2 and FeCl_3],pH value(3.0～10.0)in medium and the fermentation temperature(25,28,30,33,35,37 and 40℃)were optimized by single factor test,while the contents of components[xylan,(NH_4)_2HPO_4and bean powder]by response surface method.The high alkaline xylanase-producing strain was fermented by using the optimized medium under the optimized condition,and determined for xylanase activity,and the result was compared with that predicated in model.ResultsA high alkaline xylanase-producing strain named as SX6-18 was screened and identified as Paemibacillus based on 16s rDNA sequence analysis.The xylanase produced by the strain maintained more than 70%of relative activity at temperatures of 25～55℃and pH 6.0～10.0.Mg(2+)promoted while Fe(2+)promoted while Fe(3+),Mn(3+),Mn(2+)and Cu(2+)and Cu(2+)inhibited the activity of xylanase.The optimal carbon source,nitrogen source and metal ion of the medium were xylan,bean powder+(NH_4)_2HPO_4 and Fe(2+)inhibited the activity of xylanase.The optimal carbon source,nitrogen source and metal ion of the medium were xylan,bean powder+(NH_4)_2HPO_4 and Fe(3+),while the optimal p H value and temperature for fermentation were 8.0 and 30℃，respectively.However,the optimal component contents were 15.00 g/L xylan,3.03 g/L(NH_4)_2HPO_4and 3.28 g/L bean powder.The activity of xylanase cultured in optimized medium under opti-mized condition for fermentation reached 701.08 U/m L,which was closed to the expected value(693.96 U/m L).ConclusionA high alkaline xylanase-producing strain SX6-18 was successfully screened,which maintained relatively high enzyme activity in alkaline condition.This study laid a foundation of application of xylanase in papermaking and washing fields.

Left Ventricle Longitudinal Strain Parameters Are Effective for Differentiating Cardiac Amyloidosis from Primary Hypertensive Left Ventricular Hypertrophy / 中山大学学报(医学科学版)

ObjectiveTo clarify the value of the left ventricular longitudinal strain（LVLS）parameters in patients with cardiac amyloidosis （CA） and primary hypertension with left ventricular hypertrophy （HLVH）. MethodsForty-one patients confirmed with CA were selected and assigned to CA with hypertension group （n =14） and pure CA group （n=27） based on the initial diagnosis with or without hypertension. Twenty patients with primary hypertension-induced left ventricular hypertrophy （HLVH group） and twenty healthy controls were also selected， matching for gender， age， and body surface area. Clinical data， conventional echocardiography parameters were collected and LVLS parameters were measured. Within-group variations were compared among the four groups， and pairwise comparisons were conducted between groups. The sensitivity and specificity of each parameter in predicting CA were judged by the receiver operator characteristic （ROC） curvy in CA and HLVH patients with left ventricular ejection fraction （LVEF） preserved. ResultsAmong the conventional echocardiography parameters， LVEF and left ventricular end-diastolic diameter （LVEDD） were lower in the CA with hypertension group and pure CA group compared with the higher values in the HLVH group and control group. Whereas， left ventricular posterior wall thickness （LVPWT）， relative wall thickness （RWT）， and average E/e' were higher in the two CA groups compared with the HLVH group （all P＜0.05）.Among the LVLS parameters， Global longitudinal strain （GLS） was the worst in the CA with hypertension group so as pure CA group， modest in the HLVH group， and highest in the control group. On the contrary， relative longitudinal strain and ejection fraction strain ratio （EFSR） were the highest in the CA with hypertension group so as to pure CA group， modest in the HLVH group， and lowest in the control group （all P＜0.05）. ROC analysis showed that when LVEF was preserved， the absolute value of GLS less than 14.35% and EFSR higher than 4.28 could effectively distinguish CA from HLVH （all AUCs＞0.9，all P＜0.05）； meanwhile GLS showed high sensitivity（100%） and EFSR showed great specificity（95%）. There were not statistically significance in any parameter between CA with hypertension group and pure CA group（all P＞0.05）. ConclusionWhether CA was complicated with hypertension or not， there were statistically significance among routine echocardiography and LVLS parameters compared with HLVH. In particular， GLS and EFSR are accurate in predicting CA in patients with myocardial hypertrophy and preserved LVEF.

Effects of Cyclic Strain on Neural Differentiation of Rat Bone Marrow-Derived Mesenchymal Stem Cells / 医用生物力学

Objective To study the mechanical effects of cyclic strain on neural differentiation of rat bone marrow mesenchymal stem cells (rBMSCs). Methods The rBMSCs were subjected to cyclic strain for 24 hours andthen cultured for 5 days. The expression of neural markers and the phosphorylation of relative signaling pathway proteins were evaluated. The stress distribution on cell surface was analyzed by finite element method. The differentially expressed genes induced by strain were identified by RNA sequencing analysis. Results The 0. 5 Hz strain with 5% magnitude could significantly induce higher expression of neural markers and elevated phosphorylation level of extracellular-signal-regulated kinase (ERK), protein kinase B (AKT) and mammalian target of rapamycin ( mTOR). KEGG pathway analysis showed that the focal adhesion and ECM-receptor interaction were significantly enriched under cyclic strain. Conclusions Cyclic strain could change the interaction of cells with the extracellular matrix ( ECM) and enhance the AKT/ mTOR and ERK pathway, finally promote rBMSC neural differentiation. Knowledge about the impact of mechanical stimulation on BMSC neural differentiation is expected to improve the efficiency of stem cell differentiation, shed light on device design for tissue engineering, and promote clinical application of mesenchymal stem cells in neural issue repair and regeneration.

Cardiac magnetic resonance-feature tracking technique can assess cardiac function and prognosis in patients with myocardial amyloidosis / 南方医科大学学报

OBJECTIVE@#To quantitatively assess cardiac functions in patients with cardiac amyloidosis (CA) and hypertrophic cardiomyopathy (HCM) using cardiac magnetic resonance-feature tracking (CMR-FT) technique and evaluate the prognostic value of CMR-FT in patients with CA.@*METHODS@#We retrospectively collected the data from 31 CA patients with systemic amyloidosis confirmed by Congo red staining and serum immunohistochemistry after extracardiac tissue biopsy undergoing CMR at our hospital from March, 2013 to June, 2021.Thirty-one age and gender matched patients with asymmetric left ventricular wall hypertrophy and 31 healthy individuals without organic or functional heart disease served as the controls.Radial, circumferential and longitudinal strains and strain rates of the left ventricle at the global level and in each myocardial segment (basal, middle and apical) were obtained with CMR-FT technique and compared among the 3 groups.The predictive value of myocardial strains and strain rates for all-cause mortality in CA patients was analyzed using a stepwise COX regression model.@*RESULTS@#The left ventricular volume, myocardial mass, ejection fraction and cardiac output differed significantly among the groups (P < 0.05).Except for apical longitudinal strain, the global and segmental strains were all significantly lower in CA group than in HCM group (P < 0.05).The global and segmental strains were all significantly lower in CA group than in the healthy individuals (P < 0.05).The basal strain rates in the 3 directions were significantly lower in CA group than in the healthy individuals (P < 0.05), but the difference in apical strain rates was not statistically significant between the two groups.Multivariate stepwise COX analysis showed that troponin T (HR=1.05, 95%CI: 1.01-1.10, P=0.017) and middle peak diastolic circumferential strain rate (HR=6.87, 95%CI: 1.52-31.06, P=0.012) were strong predictors of death in CA patients.@*CONCLUSION@#Strain and strain rate parameters derived from CMR-FT based on cine sequences are new noninvasive imaging markers for assessing cardiac impairment in CA and cardiac function changes in HCM, and provide independent predictive information for all-cause mortality in CA patients.

Development and verification of an indirect ELISA method for determination of specific IgG antibody against SARS-CoV-2 variant strain in rhesus monkey serum / 中国生物制品学杂志

@#Objective To develop and verify an indirect ELISA method for determination of specific IgG antibody of rhesus monkey serum against SARS-CoV-2 variant strain. Methods An indirect ELISA method for the determination of specific IgG antibody was developed using inactivated SARS-CoV-2 Beta variant strain inactivated vaccine as coating antigen,and optimized for the coating antigen concentration(1,2 and 4 μg/mL),dilution of serum(1∶800～1∶12 800),blocking solution(PBST containing 1% BSA,2% BSA,1% skim milk,2% skim milk and 1% BSA + 1% skim milk),blocking time(30,60 and 90 min),dilution of secondary antibody(1∶5 000,1∶10 000,1∶15 000 and 1∶20 000),incubation time of serum and secondary antibody(30,60 and 90 min),and TMB reaction time(5,10,15,20,25 and 30 min). 60 negative serum samples of rhesus monkeys were detected by the developed method,and the negative and positive critical values were determined. The sensitivity and precision of the methodology were verified. In addition,the specific IgG antibody and neutralizing antibody against SARS-CoV-2 Beta variant strain in 44 serum samples of rhesus monkey were detected by the developed method and microneutralization method,and the correlation and consistency between the two methods were compared. Results The optimum detection conditions were determined:the coating antigen concentration was 1 μg/mL;the blocking solution was PBST containing 1% skim milk,and the blocking time was 30 min;the serum samples to be tested were diluted to 1∶1 600 and incubated for 90 min,and the secondary antibody was diluted to 1∶10 000 and incubated for 30 min;the color development time of substrate was 25 min. The positive critical value and negative critical value of the method was 0. 093 and 0. 084 respectively,and the detection values between them were judged as suspicious. The dilution of5 positive serum samples that showed positive results was 1∶51 200;the coefficients of variation(CVs)of precision were all less than 15%. There was a strong correlation between IgG antibody titer and neutralizing antibody level in the 44 rhesus monkey serum samples(r = 0. 858 0,P < 0. 000 1);the total coincidence rate of the two methods was 90. 9%,the positive coincidence rate was 93. 6%,and the negative coincidence rate was 84. 6%;the consistency test Kappa value was 0. 783 8(95% CI:0. 586 5～0. 981 0). Conclusion The developed indirect ELISA method for eletermination of specific IgG antibody against SARS-CoV-2 Beta variant strain in rhesus monkey serum has good sensitivity and precision,and has strong consistency with microneutralization method,which can be used for the determination of IgG antibody in rhesus monkey serum.

Online Learning and Its Short-term Impact on Digital Engagement and Digital-related Health Symptoms Amongst University Students During the COVID-19 Pandemic

@#Introduction: The COVID-19 pandemic has precipitated a rapid shift of learning and education from traditional means to digital platforms. This paper aims to examine the impact of online learning on digital engagement and digital-related health symptoms among university students one year into the coronavirus pandemic. Methods: Data was collected through a self-administered online questionnaire after ethical approval. The questionnaire was adapted from the previously published Lifestyle Study in Youth Questionnaire. Through the questionnaire, the perception of students toward online learning was probed and recorded. Digital engagement and digital-related health symptoms were compared before and during the COVID-19 lockdown. Results: The majority (97.5%) of respondents preferred face-to-face learning. The time spent on digital devices was 1.8 times higher during COVID-19 than before the COVID-19 lockdown (t-test = -18.86, p<0.0001). The total hours of sleep were reduced during COVID-19 lockdown (0.6 hours lesser) (t-test = -3.92, p<0.0001). The Wilcoxon Signed Ranks Test revealed significant changes in digital-related health symptoms (15 out of 17) due to the COVID-19 lockdown. Digital eye strain, dry eye syndrome, carpal tunnel syndrome, and upper quadrant postural and muscle strain emerged (p<0.05). Conclusion: Most university students favoured face-to-face learning compared to online learning. There was a two-fold rise in digital engagement during the COVID-19 lockdown. As a result, it has seemed to translate into reduced sleeping hours. The short-term impact of the coronavirus pandemic on digital-related health symptoms amongst university students was apparent. The long-term effects require further investigations to facilitate fact-based decision-making.