Research progress of opaque bubble layer created in corneal stroma during femtosecond laser surgery / 国际眼科杂志(Guoji Yanke Zazhi)

Femtosecond laser-assisted laser in situ keratomileusis(FS-LASIK)and small incision lenticule extraction(SMILE)are the mainstream corneal refractive surgeries at present. Despite efficacy, safety and predictability they have showed in refractive error correction, there are still complications relating to femtosecond laser, such as suction loss and opaque bubble layer(OBL), due to that the production of corneal flap or lenticule is dependent on the femtosecond laser. OBL is a complication that is unique to femtosecond laser surgery and the bubbles are generated from photo-disruptive effect towards corneal tissues which consisted of water vapor and carbon dioxide, and OBL gradually formed when the bubbles are trapped in the stroma. The bubbles can influence the intraoperative manipulation and postoperative visual quality. This review discusses the mechanism, grading, classification, and influencing factors of OBL and its effects on intraoperative manipulations and postoperative recovery, in the hope of providing reference and basis for further clinical studies.

A safer alternative approach to penetrating keratoplasty in opaque corneas

Background: This video demonstrates a useful technique of keratoplasty which can be routinely undertaken by all surgeons when imaging modalities such as anterior segment optical coherence tomography are not available and prior patient history is not forthcoming. Purpose: To demonstrate a technique of lamellar separation and layer by layer removal of host cornea when dealing with keratoplasty in perforated corneal ulcers, adherent leucomas, dense corneal opacities, which obscure visualization of the iris and anterior chamber details. Synopsis: In this video, we demonstrate penetrating keratoplasty in a failed opacified graft with iridocorneal adhesions, with no visualization of anterior chamber details. Lamellar dissection of the host cornea is done starting at its periphery and moving centrally, with gentle peeling of the superficial layers, the epithelium and bulk of stroma, following which, the deeper portion of the cornea is dissected and separated from underlying adherent iris tissue. Layer by layer separation allows better visualization through the remaining thin layers of the cornea. This permits fine dissection and layered removal of the cornea, thereby avoiding injury to iris and lens. Debulking of the host cornea decreases the force that is needed to be applied to separate adherent iris tissue from the host cornea, and reduces the chances of sudden entry into the anterior chamber and subsequent damage to the iris or lens. This also reduces the chance of iris tears, iridodialysis and bleeding from the iris and helps maintain iris integrity, which is essential intraoperatively for protection of lens and anterior chamber formation, and to avoid glare and photophobia postoperatively. Preventing iris damage also reduces the chances of formation of peripheral anterior synechiae (PAS), which can predispose to graft rejection, graft failure and secondary glaucoma. Highlights: Layer by layer corneal separation beginning inside the graft host junction, careful separation of iridocorneal adhesions and PAS is a helpful technique to optimally preserve the anterior segment anatomy during difficult cases of penetrating keratoplasty.

Effect of opaque bubble layer on the ocular cylotorsion compensation during FS-LASIK procedures / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To evaluate the effect of opaque bubble layer(OBL)on the ocular cylotorsion compensation during FS-LASIK procedures. <p>METHODS: Prospectively clinical study. From July 2019 to September 2019, two-hundred FS-LASIK patients(400 eyes)were randomly included into this study. The total OBL incidence, flap-out OBL incidence, flap-in OBL incidence, incidence of dynamic cyclotorsion component(DCC)and incidence of static cyclotorsion component(SCC)were statistically analyzed. <p>RESULTS: OBL developed in 183 eyes of 400 FS-LASIK eyes, with a total OBL incidence of 45.8%. DCC was successfully performed on 397 eyes, with a total DCC incidence of 99.2%. SCC was successfully performed on 293 eyes, with a total SCC incidence of 73.2%. Neither flap-out OBL nor flap-in OBL could disturb the successful implementation of DCC during the operation(<i>P</i>>0.05). Both flap-out OBL and flap-in OBL could impact the SCC implementation and make it fail(<i>P</i><0.05).<p>CONCLUSION: OBL can result in failure of SCC implementation during the FS-LASIK procedures.

Effect of different energy settings of SMILE on stage Ⅰ opaque bubble layer and visual quality / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To explore the effect of different energy parameters of femtosecond laser small incision lenticule extraction(SMILE)on stage Ⅰ opaque bubble layer(OBL)and visual quality. <p>METHODS: A retrospective analysis of the clinical data of 216 patients(432 eyes)who came to our hospital for SMILE surgery from July 2018 to December 2019. According to whether stage Ⅰ OBL occurred, they were divided into OBL group(42 eyes)and non-OBL group(390 eyes). The age, visual acuity parameters, corneal parameters, microlens parameters and energy parameters were compared between the two groups, and multivariate regression analysis was used to analyze the relationship between the difference in energy settings and the OBL of stage Ⅰ. The uncorrected visual acuity(UCVA), best corrected visual acuity(BCVA), and modulation transfer function cut-off spatial frequency(MTF_cut-off), Strehl Ratio(SR)and Objective Scattering Index(OSI)with energy parameters of 130, 135, 140, 145, and 150 nJ before and 1mo after surgery were compared. The correlation between energy parameters and stage Ⅰ OBL, UCVA, BCVA, MTF_cut-off, SR, OSI were analyzed. <p>RESULTS: Multivariate regression analysis showed that the energy setting with a difference of 5nJ did not show an association with stage Ⅰ OBL. In the different energy parameter groups, LogMAR UCVA, MTF_cut-off, and OSI at 1mo after surgery were improved compared with preoperatively(<i>P</i><0.05), and the difference between the groups were statistically significant(<i>F</i>=75.712, 15.304, 26.293, all <i>P</i><0.05). SMILE intraoperative energy parameters were negatively correlated with UCVA(<i>r</i>=-0.272), MTF_cut-off(<i>r</i>=-0.132), and OSI(<i>r</i>=-0.151)1mo after surgery(<i>P</i><0.05). <p>CONCLUSION: When using a 4.5μm dot pitch, in the usual energy range, the lower the energy, the better the postoperative visual quality, but it does not significantly affect the incidence of stage Ⅰ OBL during SMILE surgery.

Study of masking ability of laminate veneers for discolored teeth / 北京大学学报(医学版)

OBJECTIVE@#To select the most effective method among different masking treatments, such as different thickness and transparence, tissue surface's opaque coating, and opaque resin cement to restore discolored teeth esthetically by porcelain veneer.@*METHODS@#Four extracted intact maxillary central incisors were prepared for porcelain veneer restoration and each three heat pressed porcelain veneers from three thicknesses (0.8 mm, 1.0 mm, 1.2 mm) and two transparency(high transparence, HT and low transparence, LT))in Vita shade A2 were fabricated for each tooth, in total of 72 pieces. The surfaces of three prepared teeth were then painted to mimic situations of severe dental fluorosis, severe tetracycline teeth, and necrotic teeth. Each of the veneers was temporarily cemented to the corresponding tooth surface using try-in cements with three different colors (transparent, opaque, and yellow), then used the shade guide (3D master) and electronic colorimeter (easy shade) to record the shade of each porcelain veneer through hue, lightness, and chroma reading. After that, high-transparence porcelain veneers in thickness of 0.8 mm was fused with a layer of opaque porcelain in tissue surface, and were shade matched again after cementation. Statistic treatments were performed to analyze the difference in each masking method.@*RESULTS@#For each 0.2 mm increase in the veneer thickness of porcelain, the average lightness was reduced by 1 unit, while the chroma was not changed which was independent of the type of the resin cements. When the thickness of the porcelain veneer was decreased to 0.8 mm, the opacity effect was not remarkable even if a low-transparence porcelain veneer was used. Transparent and yellow resin cements had poor opaque performance, while opaque resin cement could reduce the lightness by 2 units and the chroma was also reduced. The opaque layer of the tissue surface could be applied uniformly, and the lightness and chroma could be reduced to Vita 2M1 to 2M1.5 levels regardless of the color of resin cements, which suggested a stable opacity effect for different discolored teeth in this study.@*CONCLUSION@#For porcelain veneer restoration of discolored teeth, thickened veneers are the most effective means to display a natural transmittance and color. Tissue surface's opacity coatings and opaque resin cements can also be used to reduce grayscale and increase lightness.

ABC genotyping and putative virulence factors of Candida albicans clinical isolates

Aims@#Candida albicans is a diploid yeast which interacts with the host in a complex nature involving several fungal virulence factors and host’s response. In this study, we investigated the different ABC genotypes of 26 clinical C. albicans isolates which is based on the presence of absence of transposable intron in the 25S rDNA, and the phenotypic expression of their virulence factors: phospholipase production, esterase production, haemolytic activities, biofilm formation, and white-opaque switching. @*Methodology and results@#In this study, we investigated the ABC genotypes of 26 clinical C. albicans isolates, and the phenotypic expression of their virulence factors. The C. albicans isolates were tested for their in vitro abilities in exhibiting the following virulence factors: phospholipase, biofilm, esterase, hemolysin and phenotypic switching. Phospholipase activities and biofilm formation were detected in 57.7% and 65.38% of the isolates, respectively. All of the isolates showed phenotypic white-type colony, while none showed esterase and hemolytic activities. ABC genotyping revealed that 50% of the isolates were grouped under Genotype A, followed by Genotype C (42.3%), and B (7.69%). @*Conclusion, significance and impact of study@#This study provides information in regard to virulence potential and the ABC genotype of C. albicans from the Philippines.

An Exome-seq Based Tool for Mapping and Selection of Candidate Genes in Maize Deletion Mutants / 基因组蛋白质组与生物信息学报·英文版

Despite the large number of genomic and transcriptomic resources in maize, there is still much to learn about the function of genes in developmental and biochemical processes. Some maize mutants that were generated by gamma-irradiation showed clear segregation for the kernel phenotypes in B73 × Mo17 F2 ears. To better understand the functional genomics of kernel development, we developed a mapping and gene identification pipeline, bulked segregant exome sequencing (BSEx-seq), to map mutants with kernel phenotypes including opaque endosperm and reduced kernel size. BSEx-seq generates and compares the sequence of the exon fraction from mutant and normal plant F2 DNA pools. The comparison can derive mapping peaks, identify deletions within the mapping peak, and suggest candidate genes within the deleted regions. We then used the public kernel-specific expression data to narrow down the list of candidate genes/mutations and identified deletions ranging from several kb to more than 1 Mb. A full deletion allele of the Opaque-2 gene was identified in mutant 531, which occurs within a ∼200-kb deletion. Opaque mutant 1486 has a 6248-bp deletion in the mapping interval containing two candidate genes encoding RNA-directed DNA methylation 4 (RdDM4) and AMP-binding protein, respectively. This study demonstrates the efficiency and cost-effectiveness of BSEx-seq for causal mutation mapping and candidate gene selection, providing a new option in mapping-by-sequencing for maize functional genomics studies.

Clinical comparative observation of SMlLE operation design of different thickness of corneal cap / 国际眼科杂志(Guoji Yanke Zazhi)

AlM: To compare the impact of different thickness of corneal cap design on small incision lenticule extraction ( SMlLE) operation.METHODS: Forty-six cases of myopia patients ( 92 eyes) intends to SMlLE operation in our hospital were collected , and were randomly divided into 2 groups:corneal cap thickness design for 110μm in group A and 120μm in group B. Other operation parameters designs were consistent. All patients were surgeried by the same surgeon. The incidence of opaque bubble layer ( OBL ) , the ratio of difficult separation of lens, uncorrected visual acuity ( UCVA ) of each time points, and spherical equivalent ( SE) were compared.RESULTS: lntraoperative OBL incidence rate of 110μm group was higher than that of 120μm group with significant difference between the two group (P0. 05). SE were compared at 7d and 6mo after operation, showed no significant difference (P>0. 05)CONCLUSlON: Compared with 120μm group, corneal cap design SMlLE operation in 110μm group are more prone to OBL and difficult separation of lens, thus affects UCVA and postoperative recovery rate. There is no significant difference in long-term UCVA.

Hemitórax opaco / Opaque hemithorax

Se presenta un paciente adulto de 58 años de edad, quien acudió a consulta por síntomas inespecíficos, relacionados con infección respiratoria, remitido desde el área de salud con una radiografía de tórax representativa de un hemitórax opaco que fue interpretada como neumonía lobar. Se realizaron diversas técnicas de imagen que incluyeron tomografía axial computarizada, angiografía pulmonar y angiotomografía que permitieron efectuar el diagnóstico diferencial de hemitórax opaco y definitivo de hipoplasia pulmonar, así como descartar anomalías asociadas. Los estudios imagenológicos permiten realizar el diagnóstico diferencial de hemitórax opaco y definitivo de hipoplasia pulmonar, así como las anomalías vasculares anexas, lo que posibilita tomar conducta y seguimiento médico adecuados.

A male 58-year-old patient presents with non-specific symptoms related to respiratory infection. The patient had been referred from his health area with a chest radiograph showing an opaque hemithorax which was interpreted as lobar pneumonia. Various imaging techniques were performed, including computerized axial tomography, pulmonary angiography and angiotomography, allowing to make the differential diagnosis of opaque hemithorax and the definitive diagnosis of pulmonary hypoplasia, and rule out associated anomalies. Imaging studies make it possible to make a differential diagnosis of opaque hemithorax and a definitive diagnosis of pulmonary hypoplasia, as well as related vascular anomalies, allowing the application of adequate clinical management and follow-up.

Unilateral lung hypoplasia: A rare cause of unilateral opaque hemithorax in chest X-ray in a young boy.

Congenital abnormalities of lung are very rare entity, and very often under or misdiagnosed by physicians. The present case, a 12-year boy, who was initially diagnosed as unilateral massive pleural effusion with collapse of lung, and after thorough investigation, including CT scan of thorax, fiber-optic bronchoscopy, and echocardiography, a final diagnosis of unilateral lung hypoplasia was made. So if a teenager present with a unilateral opaque hemithorax in chest X-ray, this entity may be a differential diagnosis.

Colon Transit Time According to Physical Activity Level in Adults

BACKGROUND/AIMS: Physical activity (PA) is associated with a reduced risk of colorectal cancer. Thus, we examined the colon transit time (CTT) according to the physical activity level (PAL) in Korean adults. METHODS: The study subjects were 49 adults: 24 males and 25 females. The subjects used an accelerometer for 7 consecutive days to measure the 1-week PAL. The subjects took a capsule containing 20 radio-opaque markers for 3 days. On the fourth day, a supine abdominal radiography was performed. According to the total activity count of all study subjects, the upper 25%, middle 50% and lower 25% were classified into the high (H), moderate (M) and low (L) physical activity (PA) groups, respectively. RESULTS: The total CTT was significantly longer in the female (25.8 hours) than in the male subjects (7.4 hours) (P = 0.002). In regard to difference on PAL, although there was no significant difference among the male subjects, the right CTT in the female subjects was significantly shorter in H group than in M group (P = 0.048), and the recto-sigmoid CTT was significantly shorter in H group than in L group (P = 0.023). Furthermore, there were significant differences in total CTT between L and M groups (P = 0.022), M and H groups (P = 0.026) and between L and H groups (P = 0.002). CONCLUSIONS: The female, but not male, subjects showed that moderate and high PAL assisted colon transit.

Opacity and masking effect of the opaque shade composite resins / 대한치과보존학회지

The purpose of this study was to assess the background color-interceptive ability and opacity of opaque shade composites (Universal composite, Filtek Z350, Charisma, Clearfil ST, Palpaque Estelite, Esthet-X, and Metafil Flo). Twenty four background specimens (diameter 5.5 mm, thickness 3.0 mm) with Root dentin Mustard (Bisco, Schaumburg, IL, USA) were made. The CIE L*a*b* value of background specimens was measured by a spectrophotometer (Spectrolino, GretagMacbeth, Regensdorf, Switzerland). Three specimens in every group were filled on the background specimens. The surface color of samples was measured by a spectrophotometer in 3.0 mm and every thickness to 0.5 mm while grinding. The color difference in the background color along with 3.0 mm specimen gauged the masking effect in each thickness while grinding and polishing. The opacity was calculated in 1 mm thick specimens. The opacity was in the decreasing order of Clearfil ST, Metafil Flo, Filtek Z350, Palpaque Estelite, Universal composite, Charisma, and Esthet-X (p < 0.05). As the thickness get reduced, L* value showed decreasing, a* increasing tendency. The surface color difference between pair of the 3.0 mm thick specimen and after grinding in same opaque resin was above 3.3 except Clearfil ST and Metafil Flo. The color difference (DeltaE*) between pair of background specimen and opaque resin builtup specimen showed more than 10.0 regardless kinds and thickness. The variance in opacity characteristics and color of the opaque composites is dependent upon manufacturer. When using the opaque resin, the optical properties of each material must be considered as well as cavity.

Contrast Test of Injection Indisposition between Disome and Monomer Diagnostic Opaque in Femoral Arteriogram / 医疗卫生装备

Objective To compare the safety and efficiency of non -ionic monomer diagnostic opaque, iodixanol (Visipaque) and that of non -ionic disomer diagnostic opaque, iohexol (Omnipaque). Methods By comparing retrospectively the DSA opacification of 60 patients from 2006 to 2007, patients′ indispositions, adverse reactions and pictorial efficiency were recorded respectively. Results In the control group, iodixanol showed less indisposition caused by injection than iohexol and there′ s no obvious difference of indisposition. Both images met diagnostic requirements. Conclusion Both iodixanol and iohexol are safe, efficient and well -tolerant diagnostic opaque. Iodixanol is better than iohexol in indisposition caused by injection.

Colonic Transit Time in Chronic Constipated Patients

PURPOSE: In most instances, constipation is considered as idiopathic or functional. The total colonic transit time, traced by radio-opaque markers, makes possible the identification of the colon segment that has the motility alteration that causes constipation. We measured the total and segmental colonic transit time in children with chronic idiopathic constipation and compared the results with those without constipation to determine whether the classification of constipation according to colonic transit time is effective or not on management of functional constipation. METHODS: A study was performed on 15 children aged from 7 to 13, with functional chronic constipation and on 10 without constipation. In all of them the total and segmental colonic transit time were measured with radio-opaque markers. The children ingested 24 markers each on three successive days, and on the fourth day a plain abdominal radiograph was performed. RESULTS: In the nonconstipated children, the total colonic transit time(mean+/-SD) was 30.7+/-10.5 hours, in the right colon 4.7+/-3.3 hours, in the left colon 4.6+/-2.3 hours, and in the rectosigmoid 21.4+/-10.3 hours. In the constipated children, the total colonic transit time was 51.5+/-16.8 hours, in the right colon 13.1+/-6.8 hours, in the left colon 14.3+/-9.8 hours, and in the rectosigmoid 24.1+/-12.6 hours. There was a statistically significant difference(P<0.05) in the total colonic transit time and in both the right and left colon transit times between the constipation and the control group. CONCLUSION: The measurement of total and segmental colonic transit time is a simple method that allows one to distinguish constipation due to colonic dysfunction(right colon and left colon) from constipation due to distal obstruction(rectosigmoid).

Clinical usefulness of KolomarkTM, a Korean radio-opaque marker for measuring colon transit time / 대한내과학회지

BACKGROUND: Among various methods for measuring colon transit time, radio-opaque marker study is simple, reproducible and economical method. The commonly used marker, Sitzmarks (Konsyl Pharmaceuticals Inc. Texas) had limitation in its use due to expensiveness and difficulty in importation. We thought that the new domestic marker comparable to Sitzmarks is necessary and made a Kolomark (Korean colon marker)TM. The comparison of radio-opaqueness and the measurement of colon transit times by two markers were done. METHODS: In two 1000 ml beakers, 350 ml of rice-gruel, several chicken-bones and ten rings of Sitzmarks and KolomarkTM were mixed separately. Then, X-ray films of the two beakers were taken. The digital image file was analyzed by Image and the value of pixels were obtained. These were repeated five times. Colon transit times were measured in 60 healthy persons stratified by age, 30 by Sitzmarks and 30 by KolomarkTM. RESULTS: The mean value of pixel of KolomarkTM was much lower than that of Sitzmarks. The difference between background or beaker and KolomarkTM was much greater than that of Sitzmarks . There was no significant difference between colon transit time studied by Sitzmarks and KolomarkTM. CONCLUSION: KolomarkTM, a more radio-opaque and cheaper marker than Sitzmarks will be applied usefully for measuring colon transit time.

The Development of Kolomark(TM), A Korean Radio-opaque Marker for Measuring Colon Transit Time / 대한소화관운동학회지

BACKGROUND/AIMS: Colon transit time is a useful method for assessing colonic motor function and classifying the type of idiopathic chronic constipation. Among various methods, a radio-opaque marker study is a simple, reproducible and economical method. The commonly used marker, Sitzmarks(R)(Konsyl Pharmaceuticals Inc. Texas) had limitations in its use due to expensiveness and difficulty in importation. We thought that a new domestic marker comparable to Sitzmarks(R) was necessary and we developed Kolomark (Korean colon marker)(TM). The radio-opaqueness of Kolomark(TM) was compared to that of Sitzmarks(R). METHODS: In two 1000ml of beakers, 350ml of rice-gruel, several chicken-bones and ten rings of Sitzmarks(R) and Kolomark(TM) were mixed separately. Then, X-ray films of the two beakers were taken. The digital image file was analyzed by image(R), a medical image processing program, and the value of pixels were obtained. These were repeated five times. RESULTS: The mean value of pixel of Kolomark(TM) was much lower than that of Sitzmarks(R). The difference between background or beaker and Kolomark(TM) was much greater than that of Sitzmarks. CONCLUSION: Kolomark(TM), a Korean colon marker which is more radio-opaque and cheaper than Sitzmarks(R) is developed and further study is needed to prove its clinical usefulness.