Problematic alcohol use among gay, bisexual, and other men who have sex with men in Canada: the role of proximal stressors and anxiety

BACKGROUND

Gay, bisexual, and other men who have sex with men (GBM) report high rates of problematic alcohol use, anxiety, and depression. This may, in part, be due to stressors related to their sexual identity (i.e., minority stressors). However, few studies have examined both distal and proximal stressors, as well as the specific psychological mechanisms by which these stressors may be related to alcohol use outcomes, in a representative sample of GBM. We explored the relationship between distal and proximal stressors and alcohol use outcomes, as well as the role of anxiety and depression as potential mediators of these relationships.

METHODS

We analyzed the baseline data of 2,449 GBM from Engage, a cohort study of sexually active GBM recruited using respondent-driven sampling (RDS) in Montreal, Toronto, and Vancouver from February 2017 to August 2019. Using structural equation modeling, we examined the associations between distal minority stressors (i.e., experiences of heterosexist harassment, rejection, and discrimination), proximal minority stressors (i.e., internalized homonegativity, concerns about acceptance, concealment, and lack of affirmation), anxiety and depression, and alcohol consumption and alcohol use problems. RDS-adjusted analyses controlled for age, income, sexual orientation, ethnicity, recruitment city, and HIV serostatus.

RESULTS

There were positive direct associations between distal stress and proximal stress, anxiety, and depression, but not alcohol use outcomes. Proximal stress had a positive direct association with anxiety, depression, and alcohol use problems, but not alcohol consumption. Anxiety was positively associated with alcohol consumption and alcohol use problems. Depression was negatively associated with alcohol consumption but not alcohol use problems. Regarding indirect effects, distal stress was associated with alcohol use outcomes via proximal stress and anxiety, but not via depression.

CONCLUSIONS

We found support for a minority stress model as it relates to alcohol use outcomes among GBM. Findings suggest that proximal minority stress and anxiety differentially impact the problematic alcohol use among GBM who experience heterosexist discrimination. Clinical providers should consider incorporating the treatment of proximal minority stressors and anxiety into existing alcohol interventions for GBM.

[Evaluation of the efficacy of urine-based lipoarabinomannan antigen test in the diagnosis of pulmonary tuberculosis]

Objective: To analyze the diagnostic efficacy of urinary lipoarabinomannan (LAM) antigen detection method in tuberculosis patients, and to provide an experimental basis for the clinical application of urinary LAM kit in China. Methods: From March to May 2023, 228 patients with lung diseases [134 male, 94 female, age 20-82 (44.8±16.7) years] were prospectively collected in Beijing Chest Hospital, Capital Medical University, including 143 pulmonary tuberculosis patients and 85 non-tuberculosis patients. Urine and sputum samples from patients were collected for traditional etiological detection and urinary LAM antigen detection. The screening results of each positive detection combination were analyzed, and the difference analysis and regression analysis were performed. Results: The detection sensitivity and specificity of the urinary LAM kit were 46.2% (95%CI: 37.9%-54.7%) and 96.5% (95%CI: 89.3%-99.1%), respectively, with an overall coincidence rate of 64.9%. The detection rate of LAM antigen detection and GeneXpert MTB/RIF (Xpert) combined (60.8%, 87/143) was significantly higher than that of Xpert alone (49.7%, 71/143), and the difference was statistically significant (P<0.05). The results of risk factor analysis showed that the risk of negative urinary LAM antigen test results increased significantly as the bacterial load decreased. Conclusions: Urine LAM antigen detection method has a high specificity and can be combined with traditional methods to effectively improve the detection rate. Urinary LAM antigen detection method still has limitations, such as the influence of bacterial load and the inability to distinguish nontuberculosis mycobacteria samples, which needs further experimental verification.

[Clinical application of combination of different types of free perforator flaps in the repair of complex wounds in extremities]

Objective: To investigate the clinical application effects of combination of different types of free perforator flaps in the repair of complex wounds in extremities. Methods: A retrospective observational study was conducted. From January 2018 to June 2022, 11 patients with complex wounds in extremities who met the inclusion criteria was admitted to the Affiliated Hospital of Zunyi Medical University, including 8 males and 3 females, aged 28 to 55 years. The wounds in the upper extremities in 4 cases and in the lower extremities in 7 cases were repaired with different combination of free perforator flaps. After debridement, the wound area was 7.0 cm×6.0 cm-28.0 cm×12.0 cm. A combination of different types of perforator flaps were applied, including the perforator tri-leaf flap of the descending branch of the lateral femoral circumflex artery in 6 cases, the descending branch of lateral femoral circumflex artery combined with oblique branch perforating branch flap in 2 cases, the lobulated flap of the descending branch of the lateral femoral circumflex artery combined with the contralateral medial plantar artery perforator flap in 2 cases, and the bilateral perforator flap of the descending branch of lateral femoral circumflex artery combined with great toe nail flap in 1 case, with the size of a single flap ranged from 2.0 cm×2.0 cm-25.0 cm×6.0 cm. The donor site was repaired by direct suture, skin grafting, or flap transplantation. During free flap transplantation, the flap was cut and split according to the distribution of perforators, and end-to-end or end-to-side anastomosis was performed between the donor area and the recipient area. After surgery, the survival of transplanted flap in the primary recipient site, the occurrence of vascular crisis, the wound healing in the flap donor site, and the survival of transplanted skin or flap in the flap donor site were observed. During follow-up, the blood supply, appearance and texture of the transplanted flap in the primary recipient site were observed; and at the same time, the weight bearing of the plantar receiving area, the presence of sliding, ulcers, and sinus tracts of the flap, and the appearance and function of the hand were observed; the complications in the donor area were observed. Results: After surgery, one patient's transplanted flap in the primary recipient site had vascular crisis but survived after exploration+vein graft bridging; partial necrosis occurred in one lobe of anterolateral thigh lobulated flap transplanted to the primary recipient site in one patient and recovered after dressing change+skin grafting, and the different types of perforator flap transplanted to the primary recipient site in the other 9 patients all survived. After surgery, the wound with direct suture at the donor site healed well, and the skin or flap transplanted to the donor area survived well. During 3-24 months of follow-up, the blood supply, appearance, and texture of the transplanted flap at the primary recipient site were good. In two patients, the anterolateral thigh flap combined with the medial plantar flap were used to repair plantar defects. The plantar receiving area was able to bear weight, and the texture of the flaps in the recipient area was close to the normal plantar skin, without flap sliding, ulcer, or sinus tract formation. In one patient, bilateral anterolateral thigh flap combined with great toe nail flap were used to repair hand combined with soft forearm defect, and the appearance and function of hand, especially thumb were good. Only linear scar was left in the donor site without other obvious complications. Conclusions: The combination of different types of perforator flaps is a reliable clinical method to repair complex wounds in extremities with high safety, good efficacy, and less complications.

[Quantitative analysis of myelofibrosis and its prognostic significance in patients with myelodysplastic syndrome]

Objective: To quantitatively analyze the reticulin fiber intensity density (RFD) in patients with myelodysplastic syndrome (MDS) by using the computer-aided grid point method, and preliminarily explore its correlation with the prognosis of MDS patients. Methods: Bone marrow (BM) slices from 32 primary MDS patients treated in Tongren Hospital Shanghai Jiao Tong University School of Medicine from February 2017 to December 2019 were observed. Images were taken by the optical microscope imaging system after the Gomori staining. The computer grid marking software was developed according to the principle of the mesh micrometer to assess RFD, meanwhile, the artificial semi-quantitative were used to assess the fibrosis of bone marrow. The co-relation between the above two methods was evaluated, and the relationship between RFD and prognosis of MDS patients were further investigated with Cox regression analysis. Results: Of the patients, there were 17 males and 15 females with a median age of 69 years (32-91 years). The RFD quantitatively analyzed by the computer-based method was positively correlated with the myelofibrosis grade by the artificial semi-quantitative analysis (r=0.497, P=0.004). The RFD in patients diagnosed with MDS complicated with excess blasts (MDS-EB) was significantly higher than that in the non-MDS-EB group((9.55%±0.75%) vs (1.71%±0.23%), P<0.001). Cox regression model analysis showed that the RFD of MDS patients had better prognostic value when compared with the artificial semi-quantitative analysis, which was also a poor prognostic factor (RR=1.337, 95%CI: 1.085-1.648, P=0.006). The overall survival (OS) of patients with RFD>5.54% was significantly shorter than that with RFD≤5.54% (P=0.001). The OS of MDS-EB patients with RFD>9.81% was significantly shorter than that in patients with RFD≤9.81% (P=0.003). Conclusion: Abnormal proliferative fibrosis of bone marrow is a potential high-risk factor for poor prognosis of MDS patients.

[Effects on learning and memory and mitochondrial energy metabolism in hippocampus of mice by subacute exposure to n-hexane]

Objective: To study the effects on learning and memory, mitochondrial energy metabolism and ATPase activity of hippocampus in mice with subacute exposure to n-hexane. Methods: The SPF 40 Kunming mice were randomly divided into low, middle and high dose groups and control groups according to different dosages. Each group consisted of 10 mice. The mice were given n-hexane by gavage, the mice in the low, middle and high dose groups were given 0.2 ml/d of n-hexane at concentrations of 500, 1000 and 2000 mg/kg respectively, while the mice in the control group were given 0.2 ml/d of cooking oil once a day for 28 days. The y-type maze test, the activity of ATP Enzyme, mitochondrial respiratory chain enzyme complex Ⅰ-IV, the mrna of mitochondrial fusion gene (MFn1, Mfn2) and fission gene (FIs1) in brain tissues were performed. Results: Except for the wrong reaction times of low-dose exposure group in the first test, there existed significantly different in the first and second Y-maze tests in exposure groups and control group (P<0.05) ; in low, middle and high-dose group, the Na(+)-K(+)-ATPase activities were (8.27±2.65) , (5.38±1.55) , (3.55±1.69) μmol/gprot/h, and Ca(2+)-Mg(2+)-ATPase activities were (10.32±2.96) , (7.19±1.94) and (4.49±1.33) μmol/gprot/h, respectively. Compared with those in control group, the activities of Na(+)-K(+)-ATPase and Ca(2+)-Mg(2+)-ATPase decreased significantly in middle-dose group and high-dose group (P<0.05) . Compared with those in control group, the activities of mitochondrial respiratory chain enzyme complex I-IV in each dose group were significantly decreased (P<0.05) . The expressions of Mfn1mRNA and Mfn2mRNA in each dose group was significantly lower than those in control group (P<0.05) . Conclusion: Subacute exposure to n-hexane can result in the decrease of activities of mitochondrial respiratory chain enzyme complex in hippocampus of mice, which may lead to the disorder of mitochondrial energy metabolism by the decrease of ATPase activity and the imbalance of mitochondrial fusion-division, which must be one of the mechanisms of impairment of learning and memory of mice induced by n-hexane.

[Analysis of trends on smoking prevalence and its risk factors in Shaanxi province 2007-2015]

Objective: To analyze the trend of smoking prevalence and its risk factors among adults in Shaanxi province from 2007 to 2015. Methods: We used data from China Chronic Disease and Risk Factor Surveillance in 2007, 2010, 2013 and 2015. The current smoking prevalence and trends of the four surveys were calculated. Its risk factors were analyzed by multivariate logistic regression from each survey and then from all pooled data of the three surveys. Results: The number of participants in 2007, 2010, 2013 and 2015 was 1 542, 3 000, 10 166 and 6 330, respectively. The current smoking prevalence dropped from 34.34% in 2007 to 26.22% in 2013, but increased to 28.33% in 2015 (trend χ(2) test: Z=2.53, P=0.01). The results from four pooled data showed that the current smoking prevalence of men was higher than that of women (OR=75.03, 95%CI: 63.57-88.55). The current smoking prevalence of people aged 45-59 was higher than that of people aged 18-44 (OR=1.28, 95%CI: 1.15-1.41). In addition, the current smoking prevalence of those who were educated for 7-9 years and more than 9 years were higher than those who were educated for less than 6 years (people with education for 7-9 years OR=1.44, 95%CI: 1.29-1.61; people with education >9 years OR=1.43, 95%CI: 1.26-1.63). The current smoking prevalence of the single was lower than those of married/cohabitants (OR=0.54, 95%CI: 0.37-0.77). The current smoking prevalence of retirees were lower than those of employees (OR=0.46, 95%CI: 0.38-0.57) and smoking prevalence of alcohol drinkers were higher than those of non-drinkers (OR=2.92, 95%CI: 2.67-3.19). Conclusion: From 2007 to 2015, the current smoking prevalence of Shaanxi population was high and the trends remained stable. It is necessary to strengthen smoking control and health education for men, people over 45 years old, people with education level 7 years and above, and working personnel in Shaanxi province.

[Differentiation of prostatitis and clinically significant prostate cancer in peripheral zone using the prostate imaging-reporting and data system]

Objective: To determine whether clinically significant prostate cancer (PCa) and prostatitis in the peripheral zone can be distinguished using prostate imaging reporting and data system version 1 (PI-RADS V1) and version 2(PI-RADS V2). Methods: Between September 2010 and August 2016, mpMRI data of 77 patients with PCa and 29 prostatitis obtained at 3.0 T were collected in Zhangjiagang Hospital Affiliated to Soochow University. Every lesion was scored according to PI-RADS (V1 and V2), as well as a sum score and a PI-RADS V2 score. The non-parametric Kruskal-Wallis test was used to assess differences between PCa and prostatitis regarding PS3, PS4 and PI-RADS V2 score. The diagnostic performance of PI-RADS V1 and V2 for detection of prostatitis in peripheral zone was compared by analyzing ROC curve. Results: The PI-RADS V1 score for PS3, PS4 and the PI-RADS V2-score were all significantly higher for PCa (PS3:12.1±2.1; PS4:16.2±2.9; V2:4.6±0.8) than for prostatitis (PS3:8.0±0.7; PS4:10.6±1.0; V2:3.0±0.5) (all P<0.01). Of these parameters, PS4 achieved the highest predictive value for the presence of prostatitis with an AUC of 0.937, sensitivity and specificity were 87.0%, 97.0% with a threshold of 12.5. Conclusion: Prostatitis can be differentiated from clinically significant PCa in peripheral zone on mpMRI using PI-RADS system, PS4 achieved better results compared to PS3 and V2.

[Clinical effects of dorsal perforator fascia pedicle flap of the deep palmar arch in the repair of skin and soft tissue defects of finger web area]

Objective: To explore the clinical effects of dorsal perforator fascia pedicle flap of the deep palmar arch in the repair of skin and soft tissue defects of finger web area. Methods: Eleven patients (7 males and 4 females, aged from 18 to 73 years) with soft tissue defects of finger web area in distal dorsal side were admitted to Xinhua Hospital (Chongming) of Shanghai Jiao Tong University School of Medicine from October 2010 to September 2018. The sizes of skin and soft tissue defects ranged from 2.5 cm×1.5 cm to 6.0 cm×2.5 cm. According to the origin, course, branches, and distribution of the dorsal perforator of deep palmar arch, and the anatomical characteristics with vascular network of dorsal carpal and dorsal metacarpal, dorsal perforator fascia pedicle flaps of the deep palmar arch from the back of the injured hands were designed and transferred to repair the wounds of finger web area in distal dorsal side. The sizes of the flaps of patients ranged from 3.5 cm×2.0 cm to 6.5 cm×3.0 cm. The donor sites were sutured directly or covered with free forearm full-thickness skin graft. The clinical effects and swelling degree of flaps in early and late stages were evaluated during the follow-up of 3 to 36 months post surgery. Results: All the flaps survived in 11 patients, the incisions in donor and recipient sites were healed. During the follow-up of 3 to 36 months post surgery, the survival of flaps was good, and the appearance, color, and elasticity were close to normal skin, with two-point discrimination distance of 7 to 10 mm and sensory function recovery of grade S(3). The wounds in donor site had small scar without infection. The efficacy was evaluated as satisfactory in 8 patients, general in 3 patients, and dissatisfactory in no patient. Flap swelling rating in early stage was 1st degree in 7 patients, 2nd degree in 2 patients, and 3rd degree in 2 patients. Flap swelling rating in late stage was 1st degree in 8 patients, 2nd degree in 2 patients, and 3rd degree in 1 patient. The extension and flexion of the metacarpal and interphalangeal joints were basically normal and the patients were satisfied with the outcomes. Conclusions: Based on the dorsal perforator of deep palmar arch, dorsal perforator fascia pedicle flap of the deep palmar arch is reliable to transfer to repair skin and soft tissue defects of finger web area in distal dorsal side, which is worthy of promotion in clinic.

Sculpting nanoparticle dynamics for single-bacteria-level screening and direct binding-efficiency measurement

Particle trapping and binding in optical potential wells provide a versatile platform for various biomedical applications. However, implementation systems to study multi-particle contact interactions in an optical lattice remain rare. By configuring an optofluidic lattice, we demonstrate the precise control of particle interactions and functions such as controlling aggregation and multi-hopping. The mean residence time of a single particle is found considerably reduced from 7 s, as predicted by Kramer’s theory, to 0.6 s, owing to the mechanical interactions among aggregated particles. The optofluidic lattice also enables single-bacteria-level screening of biological binding agents such as antibodies through particle-enabled bacteria hopping. The binding efficiency of antibodies could be determined directly, selectively, quantitatively and efficiently. This work enriches the fundamental mechanisms of particle kinetics and offers new possibilities for probing and utilising unprecedented biomolecule interactions at single-bacteria level.

Optical trapping is a versatile tool for biomedical applications. Here, the authors use an optofluidic lattice to achieve controllable multi-particle hopping and demonstrate single-bacteria-level screening and measurement of binding efficiency of biological binding agents through particle-enabled bacteria hopping.

[Molecular biological and clinical characteristics of respiratory syncytial virus in children with bronchiolitis]

Objective: To investigate the clinical characteristics of respiratory syncytial virus(RSV)bronchiolitis and molecular biological characteristics of RSV in children in Beijing. Method: In a systematic retrospective study, 2 296 nasopharyngeal aspirates (NPA) were collected from children diagnosed with bronchiolitis from July 2006 to June 2016 for respiratory virus screening using direct immunofluorescence assay (DFA). For specimens positive for RSV, subgroup A or B was confirmed by real time RT-PCR and genotype of RSV was determined by amplifying the full G glycoprotein gene and sequencing. Clinical data were evaluated by the modified Tal score to compare the severity between RSV subtypes, as well as genotypes. Statistical analyses were performed using t test, Mann-Whitney U test and χ(2) test. Result: In 2 296 bronchiolitis cases, 961(41.9%) were RSV positive, including 719(74.8%) RSV A and 236 (24.6%) RSV B. The dominant RSV subtype changed from year to year: A-A-B-B-A-A-B-AB-A-AB and more bronchiolitis cases were identified in RSV A dominant years. Six genotypes of RSV A (NA1, NA2, NA3, NA4, GA5 and ON1) and 5 genotypes of RSV B (BA3, BA7, BA9, BA10 and CB1) were prevalent in Beijing. The dominant genotypes of RSV A were NA1 (55.9%) with high rates (50.0%-100%) before 2014 and ON1 (39.1%), mainly detected after 2014, while BA9 (90.6%) was the absolute dominant RSV B genotype. No significant difference in the severity of bronchiolitis was shown between cases of RSV A and B. Children positive for NA1 were more likely to stay longer in hospital (Median time: 8 days) compared to the group positive for ON1(Median time: 6 days ) (U=1.035, P=0.005) and had higher proportion of moderate to severe degree symptoms (Moderate: 41.0%, Severe: 10.0%) compared with ON1 group (Moderate: 22.9%, Severe: 4.3%) (U=9.785, P=0.008). In the group positive for ON1, more children had fever (ON1: 38.6%, NA1: 15.0%) (χ(2)=11.064, P=0.001) and more were younger than 3 months(ON1: 54.3%, NA1: 33.0%) (χ(2)=77.408, P<0.001). Conclusion: The dominant RSV subgroup changed from year to year with a shifting pattern. The correlation between RSV genotypes and the severity of disease was documented in the study.

[Effects of lappaconitine on pain and inflammatory response of severely burned rats and the mechanism]

Objective: To explore the effects of lappaconitine (LA) on pain and inflammatory response of severely burned rats and the mechanism. Methods: Forty SD rats were divided into healthy+ normal saline group, sham injury+ normal saline group, pure burn group, burn+ LA group, and healthy+ LA group according to the random number table (the same dividing method below), with 8 rats in each group. Rats in pure burn and burn+ LA groups were inflicted with about 32% total body surface area deep partial-thickness scald (hereinafter referred to as burn) on the back and right hind. Rats in sham injury+ normal saline group were sham injured. Rats in burn+ LA group were intraperitoneally injected with 1 g/L LA solution in the dosage of 4 mL/kg at 2.0 h before injury and post injury hour (PIH) 0 (immediately), 24.0, 48.0, and 72.0. Rats in healthy+ LA group were intraperitoneally injected with LA solution in the same dose at the same time points as above, and rats in healthy+ normal saline and sham injury+ normal saline groups were intraperitoneally injected with normal saline in the dose of 4 mL/kg at the same time points as above. At 1.5 h before injury and PIH 12.5, 24.5, 36.5, 48.5, and 72.5, the paw withdrawal mechanical threshold (PWMT) of injured rats was detected, and their pain behaviors were observed. The same observation and detection were conducted in rats without injury in the two groups at the same time points as above. Another 32 SD rats were divided into normal saline group, trinitrophenyl (TNP)-ATP group, minocyline group, pyridoxal-phosphate-6-azophenyl-2', 4'-disulfonic acid (PPADS) group, with 8 rats in each group, and all the rats were inflicted with the same burn injury as above. At PIH 48.0, rats in normal saline group were intrathecally injected with 10 μL normal saline; rats in TNP-ATP group were intrathecally injected with 10 μL TNP-ATP in the concentration of 30 nmol/μL; rats in minocyline group were intrathecally injected with 10 μL minocyline in the concentration of 5 g/L; rats in PPADS group were intrathecally injected with 10 μL PPADS in the concentration of 10 nmol/μL. The PWMT of rats was detected at 0.5 h before injection and 0.5 h after. At PIH 72.5, the tissue in the dorsal horn of spinal cord of rats in sham injury+ normal saline, pure burn, and burn+ LA groups was harvested to observe the co-expression of P2X(4) receptor and OX42 receptor with immunofluorescent staining and to observe the expression of P2X(4) receptor and count the positive cells with immunohistochemical staining. The venous blood was harvested for determination of serum content of tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) with enzyme-linked immunosorbent assay. The same observation and determination were conducted in rats without injury in the two groups at the same time point as above. Data were processed with one-way analysis of variance, analysis of variance for repeated measurement, SNK test, paired t test, and Bonferroni correction. Results: (1) There were no abnormal activity in rats of healthy+ normal saline, sham injury+ normal saline, healthy+ LA groups at all time points. Until PIH 72.5, rats in pure burn group were in poor mental state; red and swollen manifestation and blister were observed in burn wounds on the back and right hind; imbalance in gait, lick, bite, and scratch were observed occasionally. Fewer behaviors such as lick, bite, and limp were observed in rats in burn+ LA group than in pure burn group, and the red and swollen manifestation in wounds of rats in burn+ LA group dissipated faster than that in pure burn group. (2) At 1.5 h before injury, there were no significant differences in the PWMT values of rats in healthy+ normal saline, sham injury+ normal saline, pure burn, burn+ LA, and healthy+ LA groups (F=0.106, P>0.05). PWMT values of rats in pure burn group were significantly lower than those in the other 4 groups at all post injury time points (with P values below 0.05). PWMT values of rats in burn+ LA group were significantly lower than those in healthy+ normal saline, sham injury+ normal saline, and healthy+ LA groups at all post injury time points (with P values below 0.05). (3) At 0.5 h before injection, PWMT values of rats in normal saline, TNP-ATP, PPADS, and minocyline groups were close, respectively 15.3±0.8, 15.1±1.0, 15.3±0.9, and 15.6±1.1 (F=0.343, P>0.05). At 0.5 h after injection, PWMT values of rats in normal saline group and PPADS group were respectively 15.2±1.2 and 14.8±1.0, which were significantly lower than 20.8±1.4 and 26.3±1.0 in TNP-ATP group and minocyline group respectively (with P values below 0.05). PWMT values of rats in normal saline and PPADS groups were similar before and after injection (with t values respectively 0.073 and -0.772, P values above 0.05), while those of rats in TNP-ATP and minocyline groups were higher after injection than before injection (with t values respectively -10.180 and -20.813, P values below 0.01). (4) At PIH 72.5, co-expression of P2X(4) receptor and OX42 receptor was observed in a few microglias of rats in healthy+ normal saline, sham injury+ normal saline, and healthy+ LA groups, while co-expression of P2X(4) receptor and OX42 receptor was observed in a large number of microglias of rats in pure burn and burn+ LA groups. At PIH 72.5, more P2X(4) receptor positive cells were observed in rats in pure burn group than in the other 4 groups (with P values below 0.05), and more P2X(4) receptor positive cells were observed in rats in burn+ LA group than in healthy+ normal saline, sham injury+ normal saline, and healthy+ LA groups (with P values below 0.05). (5) At PIH 72.5, the serum content of TNF-α and IL-1β of rats in pure burn group was significantly higher than that in the other 4 groups (with P values below 0.001). The serum content of TNF-α and IL-1β of rats in burn+ LA group was significantly lower than that in healthy+ normal saline, sham injury+ normal saline, and healthy+ LA groups (with P values below 0.001). Conclusions: LA has significant analgesic effects on severely burned rats, and it can ameliorate the excessive inflammational situation. The mechanism may be related to its inhibition of expression of P2X(4) receptor in microglias in the dorsal horn of spinal cord and reduction in the release of inflammatory factors TNF-α and IL-1β.

Apodized waveguide arrays induced by photorefractive nonlinear surface waves

A new type of nonlinear waveguides, photorefractive surface optical waveguides is suggested, which can be induced by photorefractive surface waves on the boundary of photorefractive crystal. The disturbed refractive index distribution of such waveguides behaves as a periodic lattice with apodized envelope, thus we call them photorefractive surface apodized waveguide arrays. Moreover, the dispersion relation and corresponding modes are analyzed. It is very interesting that the dispersion curves of index-guided modes and Bragg-guided modes couple and intertwine with each other, and anti-crossings instead of crossings between them hence generate some mini-gaps. Moreover there exists a type of extraordinary modes constituted by the splice of index-guided modes and Bragg-guided modes.

Observation of photorefractive surface waves in self-defocusing LiNbO3:Fe crystal

Photorefractive (PR) surface waves (SWs) in self-defocusing LiNbO(3):Fe are studied theoretically and experimentally. We demonstrate that SWs can also be formed in a self-defocusing nonlinear medium and that the nonlocal nonlinearity (such as the diffusion component of PR nonlinearity in this Letter) is the essential cause. The forming process of PR SWs with a self-deflection course of light beams has been observed. The results indicate the possibility of concentrating light energy in self-defocusing media, taking advantage of SWs.

Surface dark screening solitons

We report on the existence of surface dark screening solitons at the interface between a dielectric medium (air) and a self-defocusing nonlinear material, taking advantage of photorefractive diffusion and drift nonlinearities. It is very interesting that a surface dark soliton is just like half of a dark soliton in bulk, but not a whole dark soliton propagating along surface. The excitation, propagation, and stability of this type of soliton are studied by using the beam-propagation method. Another interesting thing is that this type of dark soliton can be excited by a planar light beam without a necessary dark notch.

Giant enhancement of surface second-harmonic generation using photorefractive surface waves with diffusion and drift nonlinearities

Giant enhancement of second-harmonic generation (SHG) with 83.4%/W coversion efficiency is obtained, taking advantage of photorefractive surface waves with diffusion and drift nonlinearity. In this method, the self-bending induced by diffusion nonlinearity can be utilized at the surface and can solve the phase-mismatch problem in bulk due to beam self-bending. With drift nonlinearity, an applied external electric filed and background illumination can further constringe surface waves to the surface and consequently enhance SHG, which provides the possibility and flexibility of control.

Spatial pattern and heterogeneity of soil organic carbon and nitrogen in sand dunes related to vegetation change and geomorphic position in Horqin Sandy Land, Northern China

To assesses the effect of geomorphology, topography, and vegetation changes on spatial pattern of soil organic carbon (C) and total nitrogen (N) in sand dunes, we used the quantitative methods to examine the spatial heterogeneity of vegetation cover, soil organic C, and total N in an 11-year naturally restored mobile dune (RMD11) and a 20-year naturally restored mobile dune (RMD20) that had been fenced to exclude grazing in Horqin Sandy Land, northern China. Our results showed that the vegetation cover, plant density, species number and diversity, soil organic C, and total N increased from RMD11 to RMD20 and increased from the 50 x 50-m plot (crest) to the 100 x 100-m plot (slope) in each dune. Geostatistical analysis showed that the spatial structural variance accounted for the largest proportion of the total sample variance in vegetation cover, soil organic C, and total N in each dune plot. Calculated spatial autocorrelation ranges of vegetation cover, soil organic C, and total N increased from RMD11 to RMD20, indicating that longer time since vegetation restoration results in a more homogeneous distribution of vegetation cover, soil organic C, and total N in sand dunes. In addition, the spatial continuity of vegetation cover, soil organic C, and total N decreased from the 50 x 50-m plot (crest) to the 100 x 100-m plot (slope) in each dune. These results suggest that the spatial distribution of soil organic C and total N in sand dunes is associated closely with geomorphic position related to the dune crest and slope, relative elevation of sampling site, and vegetation cover. Understanding the principles of this relationship between them may guide strategies for the conservation and management of semiarid dune ecosystems.

(2+1)D surface solitons in virtue of the cooperation of nonlocal and local nonlinearities

We introduce a type of (2+1)D surface soliton in virtue of the cooperation of nonlocal and local nonlinearities. Furthermore, taking advantage of diffusion and drift nonlinearity this type of surface soliton is demonstrated theoretically and experimentally in a storintium barium nitrate crystal. The dynamics behavior of the excitation and propagation of this type of surface soliton are studied using the beam-propagation method and the nonlinear equation of light rays.

Effects of 2-hydroxypropyl-beta-cyclodextrin on pharmacokinetics of digoxin in rabbits and humans

Considering the narrow therapeutic index of digoxin and the low range between the safe and toxic serum concentrations of this drug, to evaluate the relative bioavailability of tablets and oral solution is necessary. The pharmacokinetic properties of digoxin after oral administration of its hydroxypropyl-beta-cyclodextrin (HPCD) inclusion complex to rabbits and human volunteers were investigated in comparison with those of commercially available tablets. The aqueous solubility of digoxin was enhanced by HPCD for about 2000 times at HPCD concentration of 50% (w/v). But in a human bioavailability study no significant difference was observed in the extent of absorption (AUC(0-t)) and Cmax between the two formulations. Time to reach peak was significantly shorter for the solution than for the tablets (p < 0.01). The pharmacokinetic results from the rabbit study were similar to human studies and no significant difference was observed for AUC, Cmax and Tmax. As the bioavailability of both tablets and solution is equivalent HPCD based oral digoxin solution could serve as an alternative to tablets.

[Microstructure of erbium-doped Si-rich thermal oxidation SiO2/Si luminescent thin films]

Er ions with 108 keV to a dose of 1 x 10(17) cm-2 were implanted into Si-rich thermal oxidation SiO2/Si thin film using metal vapor vacuum arc (MEVVA) ion source implanter. Er concentration in as-implanted sample, which was attained to -10 at % correspond to the level of -10(21) atoms.cm-3, was analyzed by Rutherford back-scattering (RBS) and X-ray photoelectron spectroscope (XPS). Contents of Er, Si and O in annealed samples were investigated using XPS at room temperature. It showed that Si content was increased and SiO2 content was decreased with increasing the fluence of Si ions. It was found by use dof reflective high energy electron diffraction (RHEED) and atomic force microscope (AFM) that needle micro-crystalline Si in the surface of annealed samples had been formed and Er segregation and precipitation were formed little. Photoluminescence around 1.54 microns from Er-doped Si-rich thermal oxidized SiO2/Si thin film were studied with a He-Cd laser pumping at 414.6 nm at the low temperature of 77 K and room-temperature (RT).

[Effect of ICAM-1/LFA-1 on hypoxia/reoxygenation injury of cardiomyocytes mediated by neutrophils]

AIM

To observe the effect of hypoxia/reoxygenation on the adherence of neutrophils to cardiomyocytes and to investigate the effect of ICAM-1/LFA-1 on hypoxia/reoxygenation injury of cardiomyocytes mediated by neutrophils.

METHODS

Count adhered neutrophils to cardiomyocytes suffering hypoxia, hypoxia/reoxygenation and normal culture, as well as adhered neutrophils that were blocked by anti ICAM-1 and LFA-1 monoclonal antibodies. Release of lactate dehydrogenase (LDH) was determined as injury index of cardiomyocytes.

RESULTS

Adherence of with normal culture group (P < 0.01). The neutrophils to cardiomyocytes with hypoxia/reoxygenation were significantly increased compared lease of LDH by cardiomyocytes was also significantly increased (P < 0.01). There was no significant difference between hypoxia group and normal control (P > 0.05). The adherence of neutrophils to hypoxia/reoxygenation cardiomyocytes was significantly inhibited by anti-ICAM-1 and anti-LFA-1 antibody compared with normal culture group (P < 0.01). While release of LDH markedly decreased (P < 0.01).

CONCLUSIONS

Hypoxia/reoxygenation increased the adherence of neutrophils to cardiomyocytes. ICAM-1 and LFA-1 mediated the enhanced adherence of neutrophils to hypoxia/reoxygenation cardiomyocytes. Anti-ICAM-1 and anti-LFA-1 antibody attenuated the cytotoxic effects of neutrophils on hypoxia/reoxygenated cardiomyocytes. These results suggested that the damage of neutrophils on cardiomyocytes is partly mediated by ICAM-1/LFA-1. Anti ICAM-1 and LFA-1 antibody are both beneficial in protecting hypoxia/reoxygenation cardiomyocytes from injury mediated by neutrophils.

Human papillomavirus and p53 protein immunoreactivity in condylomata acuminatum and squamous cell carcinoma of penis

AIM

To determine the immunoreactive pattern of human papillomavirus (HPV) antigen and p53 protein in condylomata acuminatum (CA) and squamous cell carcinoma (SCC) of penis.

METHODS

Immunohistochemistry for HPV and p53 were performed in 40 specimens of formalin fixed, paraffin embedded tissues using a polyclonal (rabbit) antibody against HPV and a monoclonal (mouse) antibody against human p53 protein. Twenty one cases of CA and nineteen cases of SCC were examined.

RESULTS

HPV antigen was detected in all 21 CA and 2 penile SCC. p53 protein overexpression was observed in 12 of 19 (63%) SCC in which 6 cases were strong positive. Five of 21 CA (24%) showed low-grade p53 protein overexpression.

CONCLUSION

CA is related to HPV infection and some cases show p53 protein low-grade overexpression. In contrast, p53 protein overexpression is common in penile SCC, which is seldom related to HPV infection.

[Nucleic acid hybridization technique detection of enterovirus RNA in myocarditis]

Forty five specimens from human myocarditic or myopathic tissues were examined for enteroviruses by in situ hybridization with 2 biotin labelled generic enterovirus probes pCBIII/35 and pCBIII/51. Positive hybridization signals were obtained in 12 samples (26.6%). Enterovirus RNA were obtained in 5 out of these 12 samples (41.7%) by the presence of positive hybridization signals with a coxsackie B3 virus type-specific probe pCBIII/29. The positive hybridization signals were primarily localized within the cytoplasm of single or several myocytes and the myocardial interstitial tissues, and were also occasionally seen within the cytoplasm of endotheliocytes of blood vessels in the myocardium.

[Clinical pathological study of resected thymus from 104 myasthenia gravis patients]

One hundred and four thymuses from patients with myasthenia gravis were reviewed for clinical pathological manifestations. 6 cases were examined by immunohistochemical techniques with CK, EMA, CEA, UCHT1, T4, T8, L26, S-100 and electronmicroscopy. 73 cases had long term follow-up after thymectomy. Microscopically, there was lymphocytic hyperplasia associated with formation of germinal centers and branching proliferation of capillaries, which were characteristic. Electronmicroscopically there were abundant cytoplasmic projections of lymphocytes. Interdigitating pattern of the projections were frequently seen between the lymphocytes and crevice-like patterns were formed between the endothelial cells of capillaries. Immunohistochemically, the thymus had both proliferation of T cells (UCHT1, T4) and B cell reaction (L26) as well as CK and S-100 positive cell expression. It is suggested that the prognosis of myasthenia gravis after resection of thymus is related to clinical type, age and pathological changes. 95.1% of adult type I or II cases which were associated with hyperplasia of lymphoid tissue of the thymus, but not thymomas, improved after thymectomy and had better prognosis than others.

[Comparison of the ultrastructural and clinical studies on myocardium in patients with congenital heart disease]

Right ventricle myocardium of 25 cases of tetralogy of Fallot and 11 cases of ventricle septal defect were studied by both light and electron microscopy. Normal human myocardium from 4 cases were used as the control. The resulting data indicate that the mean muscle diameter correlated significantly with the course of disease, mean pressure of right ventricle and diameter of ventricle septal defect. In 6 cases with congenital heart disease, the myocardium was atrophic and presented with 2 types of ultrastructural features: accumulation of Z-line material or hyperplasia of the mitochondria. The significance of these ultrastructural findings in congenital heart disease is discussed.

Protective effects of silybin and tetrandrine on the outcome of spontaneously hypertensive rats subjected to acute coronary artery occlusion

The effects of silybin and tetrandrine on the survival of spontaneously hypertensive rats subjected to acute coronary artery occlusion were investigated. The mortality after acute coronary occlusion in spontaneously hypertensive rats (66.7%) was higher than that of control Wistar-Kyoto rats (20%, P < 0.05). Oral administration of silybin (300 mg/kg daily) for 8-12 days reduced mortality in spontaneously hypertensive rats (0, P < 0.01 in comparison with untreated spontaneously hypertensive rats). Administration of tetrandrine 40 mg/kg daily for 8-12 days reduced the mortality to some extent (22.2%, P = 0.051, as compared with control rats). Silybin reduced blood pressure and the incidence of post-occlusion arrhythmias in spontaneously hypertensive rats to the same extent as tetrandrine. Both silybin and tetrandrine decreased the severity of ventricular hypertrophy. Although there were significant decreases in risk zone and infarct zone in silybin- and tetrandrine-treated rats, the ratio of infarct to risk zone was not changed. The results implies that silybin may be beneficial when used in hypertensive patients who develop acute myocardial infarction.

Plasma levels of cyclic nucleotides in chronic congestive heart failure and their clinical implication

Plasma levels of cyclic nucleotides were determined by radioimmunoassay in 196 cardiac patients and 50 normal persons. Plasma levels of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) increased with the deterioration of cardiac function. The level of cGMP was correlated with the cardiothoracic ratio, ratio of pre-ejection period and left ventricular ejection time, the intracardiac diameter, left ventricular ejection fraction and left ventricular short axis shortening (r = 0.55, r = 0.50, r = 0.55, r = -0.53 and r = -0.50, respectively; P < 0.001). There were only weak correlations between the level of cAMP and the cardiothoracic ratio, the ratio of pre-ejection period and the left ventricular ejection time, left ventricular ejection fraction, and left ventricular short axis shortening (r = 0.35, r = 0.38, r = -0.28 and r = -0.31, respectively; P < 0.01). The correlations between cGMP and mean pulmonary artery pressure (r = 0.48; P < 0.05) and mean left atrial pressure (r = 0.55; P < 0.01) were also significant. In patients who had received cardioversion and valve replacement the plasma cGMP level decreased significantly. During the follow-up period, 29 of 108 patients died (26.9%), the initial plasma levels of cAMP and cGMP in the dead group were significantly higher than those in the survival group (27.41 +/- 1.13 and 31.11 +/- 3.33 vs. 21.56 +/- 0.60 and 17.45 +/- 1.05 nmol/l, respectively; P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

[Effects of silybin on acute myocardial infarction and reperfusion injury in anesthetized rats]

The effects of silybin (Sil) on myocardial infarction size and ischemia- and reperfusion-induced arrhythmias were studied in anesthetized open chest Sprague-Dawley rats. It was found that pretreatment with Sil 20, 50, and 80 mg.kg-1 iv reduced significantly infarct size by 34.7%, 35.0%, and 50.6% respectively at 4 h after ligation. Sil prevented ischemic arrhythmia only at the dose of 80 mg.kg-1. In reperfusion experiment, pretreatment with Sil 20 mg.kg-1 decreased significantly reperfusion-induced arrhythmia.

Histopathologic study of cholestasis induced by total parenteral nutrition or intraperitoneal sepsis in rats

Wistar rats were divided into two groups, intraperitoneal sepsis group (group IS) and total parenteral nutrition group (group TPN), to evaluate the characteristics of pathologic alterations in rats with cholestasis. Biochemical assay showed that cholestasis developed in both groups after 10 days. Light microscopic examination of liver specimens revealed that the degeneration in the intermediate and external zone of hepatolobules was the major alteration in group IS, and group TPN showed characteristic dilation of central veins and hepatic sinuses and the proliferation of Kupffer cells with marked phagocytosis. Electron microscopic pictures presented the enlargement of bile canaliculi with altered microvilli in group IS and many highly electron-dense bile particles within cytoplasm and secondary lysosomes near dilated bile canaliculi in group TPN. It is concluded that there were different histopathologic alterations of liver specimens in TPN-supported animals and septic animals when cholestasis developed. It is unsuitable to take intraperitoneal sepsis as a unique factor of cholestasis in TPN-supported rats. Bile stasis is only one sign of TPN-induced hepatic lesion, which needs further exploration to determine its causes and mechanisms.

Changes of plasma immuno-reactive beta-endorphin content in patients with congestive heart failure and their clinical significance

Immunoreactive beta-endorphin (ir-beta-EP) content in plasma was measured by radioimmunoassay in 101 cardiac patients and 30 normal subjects. The results showed that plasma ir-beta-EP levels in patients of Class II (New York Heart Association Classification), Class III and Class IV were significantly higher than those in the normal group and those in patients of Class I (43.14 +/- 2.80, 54.25 +/- 4.47, 79.28 +/- 8.96 ng/L vs 24.23 +/- 2.13, and 24.98 +/- 3.35 ng/L, respectively, P less than 0.01). Plasma concentration of ir-beta-EP in patients complicated with atrial fibrillation was significantly higher than that in patients without atrial fibrillation (56.27 +/- 4.13 vs 44.66 +/- 3.41 ng/L, P less than 0.05). Ir-beta-EP contents in plasma were correlated positively to the cardiothoracic ratios (r = 0.63, P less than 0.001) and PEP/LVET ratios (r = 0.33, P less than 0.01), and were correlated negatively to the left ventricular ejection fraction and axis shortening (r = -0.41 and r = -0.39, P less than 0.001). These results indicated that plasma ir-beta-EP content may serve as a parameter in evaluating cardiac dysfunction.

[Electron microscopic study on the diagnosis of 223 neoplasms]

223 neoplasms were submitted to electron microscopic (EM) study and diagnosis during a three-year period. It was demonstrated that EM provided a more precise pathologic diagnosis in 135 cases (60%), corrected the original diagnosis by light microscopy (LM) in 11 cases (5%) and confirmed diagnosis made by LM in 62 cases (28%). Anyhow, EM failed to give a good turn to the diagnosis in 15 cases (7%), because of unsatisfactory specimen provided or improperly processed. EM contributes greatly to the diagnosis of neuroendocrine tumors and the neoplasms from skin and soft tissue. The study verified that EM is of significant diagnostic value, for its capability of more accurately defining the histogenesis of certain tumors.

Human pituitary somatotroph adenoma and prolactinoma: an ultrastructural and immunoelectron microscopical study

17 cases of pituitary somatotroph adenoma and 38 cases of prolactinoma were studied with electron microscopy and immunoelectron microscopy using protein A-gold complex. 4 adenomas were shown by immunoelectron microscopy to contain simultaneously growth hormone (GH)-producing and prolactin (PRL)-producing cells. 6 cases were classified as densely granulated GH adenomas and 11 as sparsely granulated variant, whereas only 3 adenomas out of 38 prolactinomas were identified as densely granulated adenomas. The present study showed that not all cells with fibrous bodies possessed secretory granules positive for GH, and in some cells with fibrous bodies PRL-producing granules were also detected. Misplaced exocytosis was found frequently in the sparsely granulated prolactinomas. From these findings it may be suggested that fibrous bodies are not a morphological feature characteristic of pituitary somatotroph adenomas.

[A study of the relation of the expression of beta-microglobulin and hepatocytic lesions in hepatitis B]

Beta 2-Microglobulin expression on hepatocyte membrane was studied in 117 liver biopsies from patients with acute and chronic hepatitis B and in 11 subjects with normal liver function, using immunohistochemical PAP method. In normal liver beta 2-microglobulin could not be detected on hepatocyte membrane, compared with that in subjects with normal liver, in asymptomatic HBsAg carrier and in patients with chronic persistent hepatitis, there is significant enhancement of beta 2-microglobulin expression in patients with acute mild hepatitis and chronic mild active hepatitis. Beta 2-Microglobulin expression in patients with chronic active hepatitis with moderate to severe activity and cirrhosis has a significant enhancement, when compared with acute mild hepatitis and chronic mild active hepatitis. Moreover, location of beta 2-microglobulin expression on hepatocyte membrane was associated with lesion of hepatocytes. Enhanced expression of beta 2-microglobulin on hepatocyte membrane in acute and chronic hepatitis B probably reflects enhanced display of HLA-ABC antigens and may influence the course of hepatitis B virus infection by increasing susceptibility of T cell-mediated hepatocytelysis.

[Plasma level of cyclic nucleotides in patients with congestive heart failure and their clinical significance]

Plasma concentrations of cyclic nucleotides were determined by radioimmunoassay in 196 cardiac patients. The results showed that plasma concentrations of cyclic AMP and cyclic GMP increased with the deterioration of cardiac function. Plasma cyclic GMP concentrations were correlated positively to the cardiothoracic ratios (CTR), PEP/LVET, and the intracardiac diameters measured by echocardiography respectively (r = 0.55 r = 0.50, and r = 0.55, P less than 0.001), and were correlated negatively to the left ventricular ejection fractions (LVEF) and LV short axis shortenings (LVSAS) (r = -0.53 and r = -0.50 respectively, P less than 0.001). There were only weak correlations between plasma cyclic AMP concentrations and CTR, PEP/LVET ratios, LVEF and LVSAS (r = 0.35, r = 0.38, r = 0.28, and r = -0.31, respectively, P less than 0.01). The correlations between plasma cyclic GMP concentrations and mean pulmonary artery pressures (r = 0.48, P less than 0.05) and mean left atrial pressures (r = 0.55, P less than 0.01) were also significant. In patients who had received cardioversion and valve replacement, plasma cyclic GMP concentrations decreased significantly. Thus the plasma concentrations of cyclic nucleotides could be used as a useful parameter in evaluation of cardiac function and therapeutic effect.

[Electron microscopic observations of Campylobacter pyloridis in chronic gastritis]

Gastric biopsies from 150 cases of chronic gastritis were studied by electron microscopy. The infection rates of Campylobacter pyloridis (CP) were 95.3% (85 cases) and 69.2% (65 cases) in superficial gastritis and atrophic gastritis respectively. A close relationship was seen between quantity of the bacteria and activity of the disease. Electron microscopy showed that CP usually damaged the columnar and pit cells of the stomach, resulting in necrosis and active inflammation of the mucosa, and infection of CP might act as a very important pathogenic factor of chronic gastritis.