Analysis of occurrence and influencing factors of fundus arteriosclerosis in HIVAIDS patients after long-term highly active antiretroviral therapy / 中国热带医学

@#Abstract: Objective　To investigate the fundus arteriosclerosis and its influencing factors in HIV/AIDS patients after long-term highly active antiretroviral therapy (HAART). Methods　The clinical basic data and fundus examination data of 203 HIV/AIDS patients before and after HAART in the Fourth People 's Hospital of Nanning from January 2020 to June 2022 were collected to evaluate the occurrence of fundus arteriosclerosis and analyze its influencing factors. Results　Of the 203 HIV/AIDS patients, 159 patients developed fundus arteriosclerosis, with an incidence of 78.33%, including 33 patients with grade Ⅰ(20.75%), 87 patients with grade Ⅱ (54.72%), 28 patients with grade Ⅲ(17.61%), and 11 patients (6.92%) with Grade Ⅳ. Before HAART, there was no significant difference in CD4+T lymphocyte count, CD8+T lymphocyte count, viral load, white blood cell count, platelet count, hemoglobin, serum creatinine, blood urea nitrogen, triacylglycerol, total cholesterol, fasting blood glucose, alanine aminotransferase, aspartate aminotransferase and serum total bilirubin between the atherosclerosis group and normal group (P>0.05). After 6 months of HAART, CD8+T lymphocyte count, triacylglycerol and fasting blood glucose in atherosclerosis group were significantly higher than those in normal group (P<0.05). In the stratified comparison of CD4+ and CD8+ lymphocyte counts after 6 months of HAART, the proportion of patients with CD4+ lymphocyte count (CD4+)<200 (cells/μL) in the atherosclerosis group was significantly higher than that in the normal group; the proportion of patients with CD4+ lymphocyte count (CD4+)≥500 (cells/μL) was significantly lower than that in the normal group; the proportion of patients with CD8+ lymphocyte count CD8+≥ 800/μL was significantly higher than that in the normal group (all P<0.05). Binary logistic regression analysis showed that opportunistic infection, HIV course, CD4+T, CD8+T lymphocyte count after HAART and triglyceride were independent risk factors for ocular fundus atherosclerosis in HIV/AIDS patients (all P<0.05). Conclusions　The incidence of ocular fundus arteriosclerosis is high in HIV/AIDS patients. More than 4 years of HIV course, combined opportunistic infection, Low CD4+T lymphocyte count after 6 months of HAART, high CD8+T lymphocyte count and high triglyceride level are independent risk factors for ocular fundus arteriosclerosis in HIV/AIDS patients. Fundus screening should be performed before and after HAART in such population, HAART program should be formulated for the risk of cardiovascular disease, and risk management of cardiovascular disease should be strengthened during treatment to improve patient outcomes.

[Germplasm resource evaluation of Chrysanthemi Indici Flos based on color and chemical components].

This study explored the correlation between color and chemical components of Chrysanthemi Indici Flos(CIF), aiming at providing a reference for its procurement, evaluation, and breeding. Colorimeter and ultra-performance liquid chromatograph(UPLC) were used to determine the color(lightness-shade chromaticity value L~*, red-green chromaticity value a~*, yellow-blue chromati-city value b~*) and chemical components(cynaroside, linarin, luteolin, apigenin, and chlorogenic acid) of 84 CIF germplasms, respectively. Diversity analysis, correlation analysis, regression analysis, and cluster analysis were performed. The results showed that the color and chemical components of CIF were diversified. Chlorogenic acid was in significantly positive correlation with L~* and b~* and significantly negative correlation with a~*. Cynaroside and grey relational grade γ_i of chemical components were in significantly po-sitive correlation with b~* and L~*, respectively, whereas linarin, luteolin, and apigenin had no significant correlation with L~*, a~*, or b~*. The 84 CIF germplasms were clustered into 4 clades. In addition, germplasms in clade Ⅲ had higher γ_i and total color value(E~*_(ab)) than those in other clades, with the best quality and color, and a germplasm with the highest quality, bright yellow color, and highest content of linarin was screened out in this clade. Thus, CIF with bright yellow color had high content of cymaroside and chlorogenic acid and thereby high quality. In summary, the color can be used to quickly predict the quality of CIF. Our results provided data for the evaluation of CIF quality by color and a reference for its procurement and breeding.

[Electrophysiological and behavioral responses of gall midge, Jaapiella sp. to volatiles of host plant Lycium barbarum]. / 枸杞红瘿蚊对寄主植物挥发物的电生理和行为反应.

Plant-derived volatiles are important for guiding herbivorous insects to their host plants. Jaapiella sp. (Diptera: Cecidomyiidae) is the most serious pest of Lycium barbarum. The young flower buds of L. barbarum are attractive to females of Jaapiella sp. for oviposition in the field. In this study, we compared response of Jaapiella sp. to volatiles from flower buds of L. barbarum at different stages, and clarified the crucial semiochemicals attracting Jaapiella sp. to lay eggs. Volatiles from young and mature flower buds were collected using SPME, and then identified and quantified by gas chromatography-mass spectrometry (GC-MS). Both electrophysiological and behavior experiments were conducted to measure the attraction of eight synthetic compounds to females and screen the crucial components based on gas chromatography-electroantennogram detection (GC-EAD) and Y-tube bioassays, respectively. Results showed that qualitative and quantitative diffe-rences between two odor profiles. Consistent electroantennographic response was observed for eight compounds from headspace collections, of which five synthetic compounds (3-carene, camphene, terpinolene, d-limonene, and (+)-pinene) were essential for significant preference or avoidance. Our results indicated that these compounds from L. barbarum flower buds could be effective candidates as oviposition attractant or repellents of Jaapiella sp., which would be helpful in the exploitation of new control agent to Jaapiella sp. in the field.

[Hormone response of Lycium barbarum to gall mite Aceria pallida and effects of exogenous salicylic acid on the infestation and development of gall mite]. / å®å¤æž¸æžå¯¹æž¸æžç˜¿èž¨ä¸ºå®³çš„å† æºæ¿€ç´ å“åº”åŠå¤–æºæ°´æ¨é ¸å¯¹æž¸æžç˜¿èž¨çš„å½±å“.

To investigate the hormone responses of Lycium barbarum to Aceria pallida infestation and the effects of exogenous salicylic acid on the infestation and development of gall mite, four phytohormones (salicylic acid (SA), jasmonic acid (JA), Auxin, and abscisic acid (ABA)) of L. barbarum leaves infested with A. pallida were determined by LC-MS/MS. Moreover, the effects of exogenous SA on the growth of gall and mite population were investigated. The results showed that contents of SA and JA in leaves infested with A. pallida were significantly higher (4.0 and 13.0 folds, respectively) than that in control, but that of Auxin and ABA did not change. The growth of gall was inhibited significantly by exogenous SA, with the inhibition increasing with the prolongation of treatment time. Meanwhile, mite population in galls treated with SA was significantly lower than that in control. Our results suggested that A. pallida could induce SA and JA resistance of L. barbarum, and that the exogenous SA could inhibit the growth of gall and mite population. Exogenous SA could be potentially used in A. pallida prevention.

[Metabolomics analysis of Lycium barbarum leaves after Aceria pallida infestation].

Aceria pallida is one of the most common pests in the main production areas of Lycium barbarum in China. The mite mainly feeds on foliage, leading to local tissue deformation and formation of massive galls, which seriously affects the growth and yield of L. barbarum. However, little is known about the influence of galling organisms on plant primary and secondary metabolism. In order to compare the metabolites differences between healthy and the mite infested leaves of wolfberry, and provide a scientific basis for the development and utilization of the galled leaves, L. barbarum seedlings were infested with A. pallida artificially in the laboratory, the metabolites of L. barbarum leaves were determined by LC-MS/MS. Our results showed that the leaves were rich in amino acids and flavonoid compounds. A total of 204 compounds from 16 classes were detected in L. barbarum leaves based on LC-MS/MS. The primary metabolites are mainly amino acids, and the secondary metabolites are mainly organic acids and flavonoids. The content of the metabolite in the leaves of L. barbarum was significantly affected by the mite, 30 metabolites such as flavonoids and phenylpropanoids were significantly changed, 21 metabolites were up-regulated and 9 metabolites were down-regulated significantly. There were 8 compounds which has pharmacological and biological activity, such as eriodictyol, isorhamnetin-3-O-neohesperidoside and scopoletin up-regulated significantly. Based on the above findings, we suggest that the galled leaves of L.barbarum have a potential to be developed in the future.

Ultrastructure of gap junction and Cx43 expression in gastric cancer tissues of the patients.

INTRODUCTION: Gap junctions are intercellular channels formed by connexin facilitating communication between cells by allowing transfer of ions and small signaling molecules. Connexin 43 (Cx43) is the most ubiquitous connexin in human tissues. Ample evidence suggests the role of gap junction and its connexins such as connexin 43 in human cancers including gastric cancer, which has an important place in the worldwide incidence of cancer and cancer-related deaths. Due to a number of contradictory studies and insufficient detailed examination in specific cancers, such as gastric cancer, more data on the role of gap junctions and their connexins such as Cx43 involved in gastric cancer remain necessary. MATERIAL AND METHODS: Transmission electron microscopy, Western blotting and RT-PCR were used to show the ultrastructure damage of the gap junction in the gastric carcinoma tissue as well as the expression of Cx43 protein and mRNA, respectively. RESULTS: Ultrastructure damage of the gap junction in gastric carcinoma tissue was shown while poorly differentiated tissue experienced greater damage. The expression of Cx43 protein and mRNA was higher in healthy gastric tissue than in carcinomatous gastric tissue (p < 0.05). There was higher expression of Cx43 protein and mRNA in high-medium differentiation than in poor differentiation (p < 0.05). Cx43 protein and mRNA expression is not statistically significant for different ages and sex (such as for > 56 and ≤ 56 years) (p > 0.05). CONCLUSIONS: Ultrastructural changes of gap junctions with abnormal Cx43 expression are associated with occurrence and development of gastric cancer, which provides a new research direction for gastric cancer pathogenesis and targeted therapy.

A triazole-based fluorescence probe for detecting Hg2+ ions and its biological application.

A new compound, ethyl 5-phenyl-2-(p-tolyl)-2H-1,2,3-triazole-4-carboxylate was successfully introduced and synthesized as a novel rhodamine B derivative named REPPC, and characterized by 1 H nuclear magnetic resonance (NMR), 13 C NMR, and high resolution mass spectrometry (HRMS). It showed an obvious fluorescence and UV-visible light absorption enhancement towards Hg2+ ion without interference from common metal ions in N,N-dimethylformamide-H2 O (pH 7.4). The spirolactam ring moiety of rhodamine in REPPC was converted to the open-ring form generating a 1:1 complex with the intervention of a mercury ion, verified by electrospray ionization-mass spectroscopy testing and density functional theory calculation. REPPC was used to visualize the level of mercury ions in living HeLa cells with encouraging results.

[Overwintering status and species identification of gall mite in major wolfberry production areas].

To identify the wolfberry gall mite species and their overwintering situation in different wolfberry production areas and to provide a scientific basis for their prevention and control. We investigate the phoresy overwintering situation of gall mite, and identify the species of gall mite. Our results showed that the phoretic gall mite was Aceria pallida in all the production areas. The phoresy of gall mite was a common occurrence in different production areas, and the phoresy probability was above 75%. The phoretic behavior of wolfberry gall mite occurred commonly in the other production areas. The control of this mite in different production areas should pay attention to their phoretic behavior.

Structural equation modeling analysis of social support, coping strategies, depression and suicidal ideation among people living with HIV/AIDS in Changsha, China.

INTRODUCTION: People living with HIV/AIDS (PLWHA) have a higher rate of suicide compared to the general population. Psychosocial factors closely correlate with suicidal ideation and it is essential to explain the relationships between related factors among PLWHA. OBJECTIVES: To establish a structural equation model and examine direct and indirect effects of social support, coping strategy, depression symptoms and suicidal ideation among PLWHA. PATIENTS AND METHODS: A total of 504 PLWHA completed a set of questionnaires in the HIV clinic of Changsha Infectious Disease Hospital between December 2015 and January 2016. RESULTS: Among the 504 respondents, a total of 27.2% (n=137) had experienced suicidal ideation in their lifetime. The goodness of fit for the two structural equations model was highly satisfactory. Depression symptoms had a significant direct impact on suicidal ideation (ß 1=0.401, ß 2=0.422), while problem-focused coping (ß=-0.067), emotion-focused coping (ß=-0.081) and social support (ß=-0.137) had a significant indirect effect with suicidal ideation via depression symptoms. Factors of total effects were ranked from large to small as follows: depression, social support, emotion-focused coping and problem-focused coping. CONCLUSION: Findings provide more understanding of direct and indirect associations between variables, suggesting that depression screening services, and the strengthening of social support and psychological care services among PLWHA can potentially prevent suicide.

[Key Production Process of Nitrous Oxide and Nitrogen Sources in Tuojia River].

The nitrogen (N) pollution of water is a common global problem. To understand the key production process of N2 O and identify the dominant N sources, Tuojia River, a typical agricultural watershed in a subtropical area, was investigated. To analyze the characteristics of dual nitrate isotopes (δ15N-NO3-,δ18O-NO3-) in water, and N isotope (δ15Norg) and carbon-nitrogen ratio (C/N) in sediment organic matter from four reaches(S1-S4), the stable isotopes method was used. The results showed that the sources of nitrate varied significantly among river segments and were affected by agricultural production and human habitation on the land surface. The average δ15N-NO3- in reaches S1, S2, S3, and S4 were 1.72‰, 2.62‰, 4.10‰, and -1.28‰, respectively, while the average δ18O-NO3- were 2.60‰,-0.06‰, 0.85‰, and -0.62‰. The N in terrestrial soil made a large contribution to nitrate sources in reach S1, while soil N, ammonium N fertilizer, and manure played a main role in reaches S2 and S3. Most of the nitrate came from ammonium N fertilizer in reach S4. We also found that δ15Norg in sediment organic matter ranged from -0.69‰ to 11.21‰, and C/N was between 7.30 and 12.02. The mean δ15Norg in reaches S1-S4 were 1.91‰, 2.96‰, 4.72‰, and 3.23‰, respectively, and the mean C/N values were 10.62, 8.63, 9.05, and 9.22, respectively. Although there were some differences in δ15Norg among reaches S2-S4, the dominant N source was sewage in those reaches. However, soil organic matter was the main N source in the sediments of reach S1. The mean δ18O-NO3- in reaches S1-S4 were -7.01‰,-0.17‰,-0.28‰, and -0.60‰, respectively, indicating that nitrification was the key N2 O production process in these reaches. The ratios of δ15N-NO3- and δ18O-NO3- were 0.66,-41.01,-30.23, and 9.39 in reaches S1-S4, respectively. Finally, we found that there was a positive correlation between NO3--N and δ15N-NO3-. To summarize, the N transformation and N2 O production could be dominated by the nitrification process in Tuojia River.

The evaluation of acute toxicity, antimicrobial activity of 1-phenyl-5-p-tolyl-1H-1, 2, 3-triazole, and binding to human serum albumin.

1-Phenyl-5-p-tolyl-1H-1, 2, 3-triazole (PPTA) was a synthesized compound. The result of acute toxicities to mice of PPTA by intragastric administration indicated that PPTA did not produce any significant acute toxic effect on Kunming strain mice. It exhibited the various potent inhibitory activities against two kinds of bananas pathogenic bacteria, black sigatoka and freckle, when compared with that of control drugs and the inhibitory rates were up to 64.14% and 43.46%, respectively, with the same concentration of 7.06 mM. The interaction of PPTA with human serum albumin (HSA) was studied using fluorescence polarization, absorption spectra, 3D fluorescence, and synchronous spectra in combination with quantum chemistry and molecular modeling. Multiple modes of interaction between PPTA and HSA were suggested to stabilize the PPTA-HSA complex, based on thermodynamic data and molecular modeling. Binding of PPTA to HSA induced perturbation in the microenvironment around HSA as well as secondary structural changes in the protein.

A globally convergent QP-free algorithm for nonlinear semidefinite programming.

In this paper, we present a QP-free algorithm for nonlinear semidefinite programming. At each iteration, the search direction is yielded by solving two systems of linear equations with the same coefficient matrix; [Formula: see text] penalty function is used as merit function for line search, the step size is determined by Armijo type inexact line search. The global convergence of the proposed algorithm is shown under suitable conditions. Preliminary numerical results are reported.

[Residue degradation dynamics of spinetoram in wolfberry].

The safety interval period and residue dynamics of two main components (XDE-175-J and XDE-175-L) of spinetoram in wolfberry were measured. Field experiment design and sampling method were carried out according to the "Guideline on pesticide residue trials". The wolfberry samples were extracted with acetonitrile by ultrasonic, and analyzed by UPLC-MS/MS. The wolfberry was sprayed with 6% spinetoram suspension concentrate (SC) at recommended dosage (1 500 times) and doubling dosage (750 times) (one time) at fructescence of wolfberry. The half-lives of spinetoram residue under recommended dosage treatment was 3.65-4.25 d, and all the fresh and dried fruits conform to first order kinetics equation. The dissipation rate was over 95% in fresh and dried fruits at 14 d after application. In conclusion, spinetoram belongs to the easily degradable pesticide type.

[Dissipation dynamics of spirodiclofen in wolfberry fruit].

The dissipation of spirodiclofen in fresh fruit and dry fruit of wolfberry was detected in this study to provide a reference for its safe application.According to Pesticide Residue Test Criteria of China, the open-field experiment was conducted in Zhongning courty of Ningxia province, and the dissipation of spirodiclofen was studied by acetonitrile extraction and HPLC-MS/MS detection. The results showed that the half-lives of spirodiclofen in fresh wolfberry fruit and dry wolfberry fruit were 6.9-11.2 days and 8.5-10.4 days, respectively. Spirodiclofen belongs to the easily degradable pesticide type. According to the maximum residue limits (0.5 mg•kg⁻¹) of spirodiclofen of EU for wolfberry, after recommended dosage being sprayed for once, fresh wolfberry fruit was safe to eat after 5 days, and dry wolfberry fruit was safe to eat after 21 days.

[Preliminary studies on critical control point of traceability system in wolfberry].

As a traditional Chinese medicine, wolfberry (Lycium barbarum) has a long cultivation history and a good industrial development foundation. With the development of wolfberry production, the expansion of cultivation area and the increased attention of governments and consumers on food safety, the quality and safety requirement of wolfberry is higher demanded. The quality tracing and traceability system of production entire processes is the important technology tools to protect the wolfberry safety, and to maintain sustained and healthy development of the wolfberry industry. Thus, this article analyzed the wolfberry quality management from the actual situation, the safety hazard sources were discussed according to the HACCP (hazard analysis and critical control point) and GAP (good agricultural practice for Chinese crude drugs), and to provide a reference for the traceability system of wolfberry.

[Changes in plasma levels of atrial natriuretic peptide, endothelin-1 and von Willebrand factor among newborns with persistent pulmonary hypertension].

OBJECTIVE: To investigate the changes in plasma levels of atrial natriuretic peptide (ANP), endothelin-1 (ET-1) and von Willebrand factor (vWF), and their significance among newborns with persistent pulmonary hypertension (PPH). METHODS: Sixty-six newborns with PPH (case group) (mild: 26 cases; moderate: 21 cases; severe: 19 cases), as well as 40 newborns without PPH (control group) who were hospitalized in the same period, were enrolled. The control group underwent echocardiography on admission. The case group underwent echocardiography before treatment (with refractory hypoxemia) and after 7 days of treatment for measurement of pulmonary artery systolic pressure (PASP). Meanwhile, plasma levels of ANP, ET-1 and vWF were measured using ELISA. RESULTS: Before treatment, the case group had significantly higher plasma levels of ANP, ET-1 and vWF than the control group (P<0.05), and these indices increased as PASP rose. After 7 days of treatment, the children with mild or moderate PPH showed normal PASP, and their plasma levels of ANP, ET-1 and vWF were not significantly different from those of control group. The children with severe PPH had significant decreases in all indices, but they were significantly higher than those of the control group. Plasma levels of ANP, ET-1 and vWF were significantly positively correlated with PASP before and after treatment (P<0.01). CONCLUSIONS: Changes in plasma levels of ANP, ET-1 and vWF can reflect PASP in newborns with PPH during treatment. Dynamic monitoring of these indices can help to judge the severity of PPH and guide treatment.

[Association of age-related hearing loss with ion transporter KCNQ1 and NKCC1 in cochlea of C57BL/6J mice].

OBJECTIVE: To investigate the age-related expression of KCNQ1 and NKCC1 ion transporters in the stria vascularis in the cochlea of C57BL/6J mice, and to analyze the relationship between the two ion transporters and age-related hearing loss. METHODS: Auditory function of C57BL/6J mice was measured by auditory brainstem response (ABR) at the ages of 4, 8, 14, 24, 40 weeks old respectively. The location of KCNQ1 and NKCC1 ion transporters in the cochlea of C57BL/6J mice was detected by immunohistochemistry staining. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect the levels of KCNQ1 and NKCC1 mRNA in the cochlea of C57BL/6J mice at different ages. RESULTS: The mean values for ABR thresholds in response to click, 4 kHz and 8 kHz sound stimulus of C57BL/6J mice gradually increased with age. The ABR thresholds of the mice of over 14 weeks age were significantly elevated in comparison with lower ages (P < 0.05). In the lateral wall of C57BL/6J mice cochlea, the KCNQ1 protein was mainly expressed at the apical membrane of the strial marginal cells. The localization of NKCC1 protein was mainly present at the basolateral membrane of the stria marginal cells, spiral ligament and the fibrocytes in the inferior portion of spiral limbus. Expression of KCNQ1 and NKCC1 protein in cochlea of C57BL/6J mice showed age-related decreasing. The level of KCNQ1 and NKCC1 mRNA in cochlea of C57BL/6J also showed a age-related decreasing trend. There was a significant reducing of KCNQ1 mRNA level between C57BL/6J mice of 40 and 4 weeks old (P < 0.05). In comparison with the C57BL/6J mice of 4 weeks old, the NKCC1 mRNA levels of 24 and 40 weeks old also showed significant reducing (P < 0.05). CONCLUSIONS: The mean value for ABR thresholds of C57BL/6J mice gradually increased with age. Expression of KCNQ1 and NKCC1 protein in the stria vascularis of C57BL/6J mice decreases with age. The levels of KCNQ1 and NKCC1 mRNA in cochlea of C57BL/6J showed a age-related reducing trend. Regulating after post-translation may also participate in the adjusting of the age-related decreasing of KCNQ1 and NKCC1 protein in the cochlea of C57BL/6J mice. KCNQ1 and NKCC1 ion transporters may play a critical role in maintaining normal hearing function of inner ear.

Raf kinase inhibitor protein correlates with sensitivity of nasopharyngeal carcinoma to radiotherapy.

Raf kinase inhibitory protein (RKIP) is a metastasis suppressor whose expression is reduced in nasopharyngeal carcinoma (NPC) tissues and is absent in NPC metastases. To investigate the effect of RKIP on radiosensitivity of NPC, high metastatic 5-8F with low RKIP expression and non-metastatic 6-10B with high RKIP expression were stably transfected with plasmids that expressed sense and antisense RKIP cDNA. Overexpression of RKIP sensitized 5-8F cells to radiation-induced cell death, G(2)-M cell cycle arrest and apoptosis. In contrast, downexpression of RKIP in 6-10B cells protected cells from radiation-induced cell death, G(2)-M cell cycle arrest and apoptosis. In addition, RKIP expression altered the radiosensitivity of NPC cells through MEK and ERK phosphorylation changes of Raf-1/MEK/ERK signaling pathway. We further investigated the RKIP expression in NPC patients and its association with patients' survival after radiotherapy. Downexpression of RKIP was significantly correlated with advanced clinical stage, lymph node metastasis and radioresistance. Furthermore, survival curves showed that patients with RKIP downexpression had a poor prognosis and induced relapse. Multivariate analysis confirmed that RKIP expression was an independent prognostic indicator. The data suggested that RKIP was a potential biomarker for the radiosensitivity and prognosis of NPC, and its dysregulation might play an important role in the radioresistance of NPC.

[Rapid cochlea lesion induced by co-administration of kanamycin and furosemide in mouse].

OBJECTIVE: To investigate the ototoxicity of co-administration of kanamycin and furosemide in mouse and establish a reliable model to induce a sensorineural hearing loss. METHODS: CBA/J mice strain was selected, with the age around 3-4 weeks old, to be received a single subcutaneous injection of kanamycin at dose of 1 g/kg and another single intraperitoneal injection of furosemide at dose of 0.4 g/kg 30 - 45 min afterward. The auditory brainstem response (ABR) threshold shift was tested. The series of experimental methods including propidium iodide, phalloidin staining, semithin section toluidine blue staining, TUNEL, scanning electron microscopy and transmission electron microscopy were applied to observe the characteristics of the lesion of cochlea and hair cells. The time course was set as following: before injection, 12, 24, 48 hours and 1, 2, 4, 12 weeks after injections, respectively. RESULTS: The ABR threshold shift was firstly presented a significant increase at 12 h after injection at 2, 4, 8 kHz, then the ABR threshold kept going up during next 36 h until it was presented a stable level around 90 dB. Pathological examination showed an absence of outer hair cells at basal turn rapidly since 12 h after treatment, and then by 48 h the most commonly observed lesion, where all outer hair cells throughout the length of the cochlea were killed, in the contrast, however, the inner hair cells loss were delayed and mild. TUNEL-positive nuclei demonstrated that most hair cells died via an apoptotic pathway. In scanning electron microscopy abundance of necrotic outer hair cells were detected by 24 h after treatment, in which reticular lamina were collapsed. Then all outer hair cells were replaced by expansion of heads of supporting cells. At 48 h after treatment, marginal cells presented a swollen and some of them were observed to be fused. In addition, spherical cell extrusion appeared to leak out from some marginal cells. By 2 weeks, nearly all microvillus were lost and marginal cells presented a shape of stone-like change. A significant and progressive decrease in strial vascularis thickness was found, of which the reason probably related with a reduction in volume of marginal cells. CONCLUSION: This systemic protocol eliminates hair cells extensively in vivo, and it could be a reliable model to examine different aspects of cochlear pathology in transgenic or mutant mice strains.

[Expression of plasma membrane Ca²(+)-ATPase isoform 2 in spiral ganglion cells of newborn rats].

OBJECTIVE: To study the expression of plasma membrane Ca(2+)-ATPase isoform 2 (PMCA2) in spiral ganglion cell (SGC) from inner ear of newborn rats and further check PMCA2 splice variants at site A and C. METHODS: Spiral ganglion tissues isolated from cochlea of newborn rats (P3-P4) were cultured and identified in vitro. The cochlea of newborn rats (P3-P4) were isolated and cut into frozen sections. The expression of PMCA2 was detected by immunofluorescence analyses. The SGC cultured in 4 wells of the 6-well culture plate were collected and the total RNA was extracted by Trizol and reverse transcribed to cDNA. The site A and C splice variants of PMCA2 were respectively checked by nested PCR and common PCR. RESULTS: The SGC grew well with good refraction and showed positive immunoreactivity for neuronal marker NF-200. Strong green fluorescence could be seen in cytomembrane, cytoplasm and neuritis, as well showing SGC immunoreactivity for PMCA2 antibody. In the cochlear sections, the spiral ganglion tissues were strongly stained by PMCA2. PMCA2z was present at splice site A, but PMCA2b and PMCA2c were present at splice site C. CONCLUSION: SGC from newborn rats strongly expresses PMCA2 and different splice variants are present at PMCA2 splice site A and C.