Endoplasmic Reticulum-Targeting Self-Assembly Nanosheets Promote Autophagy and Regulate Immunosuppressive Tumor Microenvironment for Efficient Photodynamic Immunotherapy

The poor efficiency and low immunogenicity of photodynamic therapy (PDT), and the immunosuppressive tumor microenvironment (ITM) lead to tumor recurrence and metastasis. In this work, TCPP-TER -Zn@RSV nanosheets (TZR NSs) that co-assembled from the endoplasmic reticulum (ER)-targeting photosensitizer TCPP-TER -Zn nanosheets (TZ NSs for short) and the autophagy promoting and indoleamine-(2, 3)-dioxygenase (IDO) inhibitor-like resveratrol (RSV) are fabricated to enhance antitumor PDT. TZR NSs exhibit improved therapeutic efficiency and amplified immunogenic cancer cell death (ICD) by ER targeting PDT and ER autophagy promotion. TZR NSs reversed the ITM with an increase of CD8+ T cells and reduce of immunosuppressive Foxp3 regulatory T cells, which effectively burst antitumor immunity thus clearing residual tumor cells. The ER-targeting TZR NSs developed in this paper presents a simple but valuable reference for high-efficiency tumor photodynamic immunotherapy.

Lunasin ameliorates glucose utilization in C2C12 myotubes and metabolites profile in diet-induced obese mice benefiting metabolic disorders

AIMS

Obesity is the main cause of low-grade inflammation and oxidation, resulting in insulin resistance. This study aimed to investigate the effects of a seed peptide lunasin on glucose utilization in C2C12 myotubes and the metabolite profiles in obese mice.

MAIN METHODS

C2C12 myotubes were challenged by palmitic acid (PA) to mimic the obese microenvironment and inflammation, cell vitality, and glucose utilization were determined. C57BL6/j mice were divided into low-fat diet (LF), high-fat diet (HF), and HF with intraperitoneally injected lunasin (HFL) groups. Glucose intolerance and metabolite profiles of the tissues were analyzed.

KEY FINDINGS

In vitro, C2C12 myotubes treated with lunasin showed decreased proinflammatory cytokines and increased cell vitality under palmitic acid conditions. Lunasin improved glucose uptake and glucose transporter 4 expression by activating insulin receptor substrate-1 and AKT phosphorylation. Next-generation sequencing revealed that lunasin regulates genes expression by promoting insulin secretion and decreasing oxidative stress. In vivo, HF mice showed increased tricarboxylic acid cycle and uric acid metabolites but decreased bile acids metabolites and specific amino acids. Lunasin intervention improved glucose intolerance and modulated metabolites associated with increased insulin sensitivity and decreased metabolic disorders.

SIGNIFICANCE

This study is the first to reveal that lunasin is a promising regulator of anti-inflammation, anti-oxidation, and glucose utilization in myotubes and ameliorating glucose uptake and metabolite profiles in obese mice, contributing to glucose homeostasis and benefiting metabolic disorders.

[Application of supraclavicular fasciocutaneous island flap for reconstruction after removal of tumors in parotid and auricle area]

Objective: To evaluate the efficacy of supraclavicular fasciocutaneous island flap (SIF) for repairing the defect of parotid or auricle regions after tumor resection. Methods: From February 2019 to June 2021, 12 patients (11 males and 1 female, aged 54-77 years old), of whom 4 with parotid adenoid cystic carcinoma and 8 with auricular basal cell carcinoma underwent reconstruction surgery for postoperative defects in the parotid gland area and auricular area with SIF in the Department of Otorhinolaryngology Head and Neck Surgery, the Second Xiangya Hospital of Central South University and their clinical data were retrospectively analyzed. Size of the SIF, time for harvesting SIF, neck lymph node dissection and postoperative complications were recorded. Results: The flap areas were (6-9) cm × (8-13) cm, and the harvesting time for SIF ranged from 40 to 80 min, averaging 51.7 min. The donor sites were directly closed. All patients underwent ipsilateral levels Ⅰ-Ⅲ neck dissection, with 4 cases undergoing additional level Ⅳ neck dissection and 2 cases undergoing level Ⅳ-Ⅴ neck dissection. Of the 12 SIF, 10 were completely survival and 2 had flap arterial crisis with partial flap necrosis, in addition, 1 had donor site wound dehiscence. With follow-up of 10-42 months, there were no tumor recurrences in 10 patients, 1 patient was lost to follow-up at 10 months postoperatively, and 1 patient experienced local tumor recurrence at 11 months after surgery and died 15 months later. Conclusion: SIF is an easily harvested flap with good skin features matching the skin in parotid and auricle regions and less damage to donor site, and this flap has no need for microvascular anastomosis technique. SIF is feasible and effective for repairing defects in parotid and auricle area.

[Feasibility and efficacy of preserving internal branch of superior laryngeal nerve in endoscopic surgery for hypopharyngeal squamous cancer: an observational study]

Objective: This study was performed to investigate the feasibility of preservation of internal branch of superior laryngeal nerve(ibSLN) during transoral endoscopic surgery for hypopharyngeal squamous cancer(HSCC) and the influence on patient's swallowing function after operation. Methods: From May 2020 to June 2021, the data of 29 HSCC patients who required for transoral endoscopic surgery in the Department of Otorhinolaryngology Head and Neck Surgery, the Second Xiangya Hospital of Central South University were prospectively included, and the included patients were divided into two groups randomly by lottery. According to whether ibSLN was actively dissected during operation, they were divided into ibSLN preservation group (n=15) and control group (n=14, without ibSLN preservation). Operation time, intraoperative hemorrhage, intraoperative neck dissection, postoperative radiotherapy, postoperative recurrence within 1 year, retention and swallowing function, the recovery of oral soft diet and the quality of life were compared between two groups. SPSS 25.0 software was used for statistical analysis. Results: The study included 29 eligible patients, including 25 males and 4 females.The age ranged from 42 to 67 (56.07±5.93) years. There were no significant differences(P>0.05) between 2 groups in the following data,including age(t=-0.56), gender(χ2=0.01), TNM stage(T stageχ2=0.29, N stage χ2=0.02), pathological diagnosis(χ2=0.03), preoperative swallowing function(χ2=0.00) and M. D. Anderson Dysphagia Inventory(MDADI) score(global t=0.55, emotional t=0.16, functional t=0.60, physical t=0.64), operation time(t=1.62) and intraoperative hemorrhage(t=-1.46), intraoperative neck dissection(χ2=0.01), postoperative radiotherapy(χ2=0.32), postoperative recurrence within 1 year(P>0.050). The swallowing function was evaluated by water swallowing test after operation. The swallowing function of ibSLN preservation group was better than control group, and the difference between two groups was statistically significant on the 1st (χ2=4.44, P=0.035), 5th (χ2=4.24, P=0.039) and 7th (χ2=4.55, P=0.033) day after operation. On the 14th day after operation, the MDADI scores of patients in the ibSLN preservation group were higher than those in the control group in global (t=2.45, P=0.021), functional (t=2.54, P=0.017) and physical (t=2.24, P=0.034) dimensions, except for emotional dimension (t=1.89, P=0.070). The median time of oral soft diet(U=23.00, P<0.001), normal oral diet(U=21.00, P<0.001) and the nasogastric tube removal time (U=18.50, P<0.001) in ibSLN preservation group was 2 days, 5 days and 6 days respectively, earlier than that in control group, which had statistically significant difference. Conclusion: Our results show that it is feasible to preserve the ibSLN during HSCC transoral endoscopic surgery, which can achieve rapid recovery of postoperative swallowing function.

Evaluation of CRISPR-Based Assays for Rapid Detection of SARS-CoV-2: A Systematic Review and Meta-Analysis

PURPOSE

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the pathogen of coronavirus disease 2019. Diagnostic methods based on the clustered regularly interspaced short palindromic repeats (CRISPR) have been developed to detect SARS-CoV-2 rapidly. Therefore, a systematic review and meta-analysis were performed to assess the diagnostic accuracy of CRISPR for detecting SARS-CoV-2 infection.

MATERIALS AND METHODS

Studies published before August 2021 were retrieved from four databases, using the keywords "SARS-CoV-2" and "CRISPR." Data were collected from these publications, and the sensitivity, specificity, negative likelihood ratio (NLR), positive likelihood ratio (PLR), and diagnostic odds ratio (DOR) were calculated. The summary receiver operating characteristic curve was plotted for analysis with MetaDiSc 1.4. The Stata 15.0 software was used to draw Deeks' funnel plots to evaluate publication bias.

RESULTS

We performed a pooled analysis of 38 independent studies shown in 30 publications. The reference standard was reverse transcription-quantitative PCR. The results indicated that the sensitivity of CRISPR-based methods for diagnosis was 0.94 (95% CI 0.93-0.95), the specificity was 0.98 (95% CI 0.97-0.99), the PLR was 34.03 (95% CI 20.81-55.66), the NLR was 0.08 (95% CI 0.06-0.10), and the DOR was 575.74 (95% CI 382.36-866.95). The area under the curve was 0.9894.

CONCLUSION

Studies indicate that a diagnostic method based on CRISPR has high sensitivity and specificity. Therefore, this would be a potential diagnostic tool to improve the accuracy of SARS-CoV-2 detection.

Effect of Agkistrodon halys antivenom in patients bit by green pit viper and the prognostic role of the disease - a retrospective cohort study

BACKGROUND AND AIMS

In Mainland China and Hong Kong, health authorities utilize Agkistrodon halys antivenom in the treatment of patients who sustained bites from green pit vipers. However, the treatment benefit of Agkistrodon halys antivenom among such patients is still controversial. The purpose of this study is to evaluate the coagulation parameters normalization time of Agkistrodon halys antivenom in patients who sustained green pit viper bites and explore independent risk factors of patient prognosis.

METHODS

Data were extracted from the Donghua Hospital Information System. Comparison of the two groups of patients - who used antivenom (GPUA) and who did not use antivenom (GPNUA) were performed using stratified analysis, univariate and multivariate ordered logistic regression models to evaluate the coagulation parameters normalization time. Univariate and multivariate ordered logistic regression models were used to explore independent risk factors of patient prognosis.

RESULTS

Between the GPUA and GPNUA groups, there is no significant difference in the coagulation parameters normalization time with the treatment of Agkistrodon halys antivenom. GPNUA consumed more cryoprecipitate and platelets and had a lower cost. The patient's severity of the bite, first coagulation profile, and dosages of fresh frozen plasma, platelet, and red cell suspension was found to be risk factors for the normalization time of coagulation parameters.

CONCLUSIONS

The therapeutic effect of Agkistrodon halys antivenom in green pit vipers bite patients is not quite satisfying. In addition, more attention should be paid to the first coagulation profile, blood clotting factors indices, platelet count (PLT), and hemoglobin when treating such patients.

Diagnostic value of Lipoarabinomannan antigen for detecting Mycobacterium tuberculosis in adults and children with or without HIV infection

Objectives

Even today, tuberculosis (TB) remains a leading public health problem; yet, the current diagnostic methods still have a few shortcomings. Lipoarabinomannan (LAM) provides an opportunity for TB diagnosis, and urine LAM detection seems to have a promising and widely applicable prospect.

Design or methods

Four databases were systematically searched for eligible studies, and the quality of the studies was evaluated using the quality assessment of diagnostic accuracy studies‐2 (QUADAS‐2). Graphs and tables were created to show sensitivity, specificity, likelihood ratios, diagnostic odds ratio (DOR), the area under the curve (AUC), and so on.

Results

Based on the included 67 studies, the pooled sensitivity of urine LAM was 48% and specificity was 89%. In the subgroup analyses, the FujiLAM test had higher sensitivity (69%) and specificity (92%). Furthermore, among patients infected with human immunodeficiency virus (HIV), 50% of TB patients were diagnosed using a urine LAM test. Besides, the CD4+ cell count was inversely proportional to the sensitivity.

Conclusions

Urine LAM is a promising diagnostic test for TB, particularly using the FujiLAM in HIV‐infected adults whose CD4+ cell count is ≤100 per μl. Besides, the urine LAM test shows various sensitivities and specificities in different subgroups in terms of age, HIV infection status, CD4+ cell count, and testing method.

[Bayesian network Meta-analysis of traditional Chinese medicine injections combined with antiviral western medicine in treatment of influenza]

To systematically evaluate the efficacy and safety of traditional Chinese medicine injections combined with antiviral wes-tern medicine in the treatment of influenza by Bayesian network Meta-analysis. Four Chinese databases(CNKI, Wanfang, VIP, CBM) and three English databases(PubMed, EMbase, Cochrane Library) were retrieved by computer for randomized controlled trials(RCT) about the comparison between the combined administration of traditional Chinese medicine injections with antiviral western medicine(or with placebo) and the single administration of antiviral western medicine in the treatment of influenza, or the comparison between two different traditional Chinese medicine injections combined with antiviral western medicine in the treatment of influenza. The retrieval time was from the establishment of the databases to July 2020. Two researchers independently screen out the literatures and extracted the data according to the inclusion criteria and exclusion criteria. The included studies were evaluated by the Cochrane 5.1 bias risk assessment tool, and data analysis was conducted by ADDIS 1.16.8 and Stata 14.0. A total of 49 literatures about 5 061 cases were included finally, involving six traditional Chinese medicine injections, namely Reduning Injection, Xiyanping Injection, Tanreqing Injection, Yanhuning Injection, Qingkailing Injection and Shuanghuanglian Injection. The results of network Meta-analysis,(1)in terms of total effective rate, 6 traditional Chinese medicine injections combined with antiviral western medicine was better than antiviral western medicine alone. In terms of probability sorting, Shuanghuanglian Injection combined with antiviral western medicine ranked first.(2)There was no significant statistical difference in adverse reaction rate among all groups, but Reduning Injection ranked first in the probability sorting, due to the least side effects.(3)In terms of antipyretic time, Yanhuning Injection, Xiyanping Injection and Tanreqing Injection combined with antiviral western medicine was better than antiviral western medicine alone and Xiyanping Injection ranked first in the probability sorting.(4)In terms of cough relief time, Qingkailing Injection and Tanreqing Injection combined with antiviral western medicine was better than antiviral western medicine alone and Qingkailing Injection was superior to Yanhuning Injection. Qingkailing Injection combined with antiviral western medicine ranked first in the probability sorting.(5)In terms of the length of hospital stay, Xiyanping Injection, Tanreqing Injection and Reduning Injection combined with antiviral western medicine was superior to antiviral western medicine alone, and Reduning Injection ranked first in the probability sorting due to the shortest hospital stay. Because of the small quantity and low quality of included studies, the results of this study shall be regarded cautiously and comprehensively. In the future, multi-center, large-sample and clinical randomized controlled trials shall be conducted to verify the results.

[A nested case-control study on relationship of traditional and combined lipid metabolism indexes with incidence of diabetes]

Objective: To explore the relationship between lipid indicators and the incidence of diabetes, and to compare the diabetes prediction and identification power of traditional lipid combined lipid indicators, in order to explore the best alternative indicators for identifying and predicting diabetes. Methods: Based on the Jinchang cohort, a nested case-control study was conducted in 1 025 new cases of diabetes after excluding patients with malignant tumor and related endocrine, circulatory system disease, then an age (±2 years), gender matched 1∶1 control group of 1 025 cases was set to analyze the relationship between the incidence of diabetes and lipid parameters. Results: Among the traditional lipid parameters, the fourth quartile of TG, TC, and LDL-C indicated higher risks of developing diabetes, which was 14.00 times (95%CI: 9.73-20.15), 2.15 times (95%CI: 1.65-2.79) and 1.66 times (95%CI: 1.29-2.14) than that of the first quartile, respectively. The risk of developing diabetes indicated by the fourth quartile of HDL-C was 0.21 times than that indicated by the first quartile (95%CI: 0.15-0.28). In the combined lipid parameters, the fourth quartile of TG/HDL-C, TC/HDL-C, LDL-C/HDL-C and non-HDL-C indicated higher risks of developing diabetes, which was 14.86 times (95%CI: 10.35-21.34), 8.12 times (95%CI: 5.94-11.01), 5.85 times (95%CI:4.34-7.88) and 5.20 times (95%CI: 3.85-7.03) than that indicated by the first quartile, respectively. The areas under the ROC curve of TG, TC, HDL-C, LDL-C, TG/HDL-C, TC/HDL-C, LDL-C/HDL-C and non-HDL-C were 0.76 (95%CI: 0.74-0.78), 0.59 (95%CI: 0.57-0.61), 0.67 (95%CI: 0.65-0.69), 0.57 (95%CI: 0.55-0.59), 0.77 (95%CI: 0.75-0.78), 0.73 (95%CI: 0.71-0.75), 0.69 (95%CI: 0.67-0.71) and 0.66 (95%CI: 0.64-0.68), respectively. The optimal diabetes predicting point cuts of TG, TC, HDL-C, LDL-C, TG/HDL-C, TC/HDL-C, LDL-C/HDL-C and non-HDL-C were 1.40, 4.70, 1.28, 3.25, 1.17, 3.43, 2.46, and 3.58 mmol/L, respectively. Conclusions: Lipid metabolic disorder is a risk factor for diabetes. TG and TG/HDL-C are the good lipid metabolism indicators for the prediction of diabetic.

[Relationship of body mass index and blood pressure with diabetes: a nested case-control study]

Objective: To explore the relationship of body mass index and blood pressure with the incidence of diabetes in Jinchang cohort. Methods: We designed a nested case-control study, a total of 29 572 workers who had no history of diabetes in baseline survey in Jinchang cohort were selected as the study cohort from June 2011 to December 2013. After 2 year follow-up, 1 021 workers with first diagnosed diabetes were selected as the case group, after 1∶1 matching according to the same gender and age ±2 years among those without diabetes, circulatory system, or endocrine system diseases during the same follow-up period, 1 021 controls was selected and 2 042 subjects were finally included. We used multivariate conditional logistic regression model, additive interaction model and multiplicative interaction model to explore the relationship of body mass index and blood pressure with the incidence of diabetes. Results: After adjusting for factors such as occupation, alcohol use, family history of diabetes, hyperuricemia, hypercholesterolemia, hypertriglyceridemia, low-HDL cholesterolemia and high-LDL cholesterolemia, multivariate conditional logistic regression analysis showed that the risk of diabetes increased with body mass index and blood pressure. Hypertension and overweight/obesity had a multiplicative interaction on the incidence of diabetes. The risks of diabetes in men and women with hypertension and overweight/obese were 2.04 times (95%CI: 1.54-2.69) and 3.88 times (95%CI: 2.55-5.91) higher than those in men and women with normal body weight and blood pressure, respectively. In the combination of BMI and blood pressure, obese individuals with SBP≥160 mmHg were 4.57 times (95%CI: 2.50-8.34) more likely to have diabetes than those with normal BMI and SBP, obese individuals with DBP≥90 mmHg were 3.40 times (95%CI: 2.19-5.28) more likely to have diabetes than those with normal BMI and DBP. Conclusions: Overweight/obesity and hypertension can increase the risk of diabetes. Health education about body weight and blood pressure controls should be strengthened to reduce the risk of diabetes.

[Prospective cohort study of relationship of triglyceride, fasting blood-glucose and triglyceride glucose product index with risk of hypertension]

Objective: To investigate the relationship of triglyceride (TG), fasting blood glucose (FPG) and triglyceride glucose product index (TyG) with the incidence of hypertension, and provide basic data for the prevention and treatment of hypertension in the population. Methods: A total of 23 581 individuals who met the research criteria in Jinchang cohort were selected as the research subjects, the Cox proportional hazard model was used to analyze the relationship of TG, FPG, and TyG with the risk of hypertension. A stratified analysis was conducted by sex. Results: After adjusting for confounding factors, compared with the normal TG group, the HR(95%CI) of the elevated TG margin group and the elevated group were 1.16 (1.01-1.34) and 1.49 (1.30-1.70), respectively in the total population. Among men, they were 1.13 (1.01-1.27) and 1.17 (1.06-1.30), and among women, they were 1.05 (0.88-1.26) and 1.06 (0.88-1.28). Compared with the normal FPG group, the HR (95%CI) of the FPG-impaired group were 1.29 (1.13-1.48) in the total population, 1.26 (1.08-1.48) in men and 1.59 (1.14-2.21) in women. Taking the lowest quartile array as a reference, the HR (95%CI) of the highest quartile array of TyG was 1.73 (1.45-2.07) in the total population, 1.32 (1.14-1.53) in men and 1.87 (1.37-2.54) in women. TG, FPG had a nonlinear dose-response relationship with the risk of hypertension, while TyG had a linear correlation with the risk of hypertension. Conclusions: Higher TG, FPG, and TyG levels are independent risk factors for the incidence of hypertension. People with higher TG, FPG and TyG are at high risk for hypertension, to which close attention should be paid in the prevention and treatment of hypertension.

[Progress of cohort studies in countries from Asia and Europe]

Objective: To share related knowledge and experiences with countries along the line, literature regarding current cohort studies was summarized. Distribution, establishment and development of cohort studies among large prospective general population were analyzed in 17 countries of Western Asia and the 16 countries of Central and Eastern Europe. Methods: Literature review was conducted to collect basic information on cohort studies, with descriptive study used to analyze the characteristics of these cohort studies. Results: There were 562 cohort studies with sample size as more than 1 000 stated in Western Asia and Central and Eastern Europe, including 468 (83.27%) carried out in the nation itself and 94 (16.73%) with international multicentered collaboration. According to the nature of cohort studies, 347 (61.74%) were etiologically based. As for the contents involved, 310 (55.16%) of them targeted on chronic/non-communicable diseases, 125 (22.24%) concentrated on maternal and child health. Among those on chronic/non-communicable diseases, 51 (16.45%) were on cancers and 83 (26.77%) on cardiovascular disease studies. There appeared 10 large prospective cohort studies targeting on general population, mainly ongoing in Iran and European countries, with a duration of 8-29 years, including 4 of them with sample size as more than 50 000. In terms of the contents, epidemiological investigation, physical examination and biological samples collection took the major parts. Few papers were published in 9 out of the 10 cohort studies at the early stage of those projects but the number of papers increased annually and stabilized to certain extent. Conclusions: The regional distribution of cohort studies carried out in countries from the Western Asia and Central and Eastern European areas appeared unbalanced. Contents of these designs would mainly involve etiological studies, with focus on non-communicable diseases as cancer, cardiovascular disease, diabetes, respiratory diseases, mental and psychological diseases, and maternal and infant health etc.. However, only few large prospective cohort studies would base on general population.

Adverse pregnancy outcomes on the risk of overweight offspring: a population-based retrospective study in Xiamen, China

The growth trajectory of Chinese preschoolers still remains unclear. Our objective was to determine whether there was an association between adverse pregnancy outcomes and overweight offspring. We analyzed population-based retrospective cohort data from the Medical Birth Registry of Xiamen, which comprised 33,157 children examined from 1 to 6 years of age. Longitudinal analyses were used to evaluate the growth trajectories of offspring body mass index (BMI). Multivariate logistic regression was used to assess the effects of two adverse pregnancy outcomes, gestational diabetes mellitus (GDM) and being large-for-gestational age (LGA), on childhood overweight. Offspring of mothers with GDM and LGA has a higher annual BMI z-score from 1 to 6 years of age (all P < 0.05). But, a higher annual BMI z-score was only observed in children aged 1-5 years in models 1-3. Overall BMI z-score of offspring aged 1-6 who were born to mothers with GDM and LGA were also higher in models 1-3 (all P < 0.05). Additionally, offspring of mothers with GDM and LGA had a higher risk for overweight in model 1, from 1 to 6 years of age (odds ratio (OR), 1.814; 95% confidence interval (CI), 1.657-1.985; P < 0.0001). However, this association was attenuated after adjusting for maternal pre-pregnancy BMI (OR, 1.270; 95% CI, 0.961-1.679; P = 0.0930). Offspring of mothers with GDM and LGA had a higher BMI z-score and increased risk for overweight. Indeed, intrauterine exposure to maternal GDM and LGA could bias offspring to overweight, whereas maternal pre-pregnancy BMI may play a key role in offspring overweight for children born to mothers with GDM and LGA.

[Effects of chronic intermittent hypoxia on blood pressure and vascular remodeling]

Objective: To investigate blood pressure and vascular remodeling of OSAS by establishing the chronic-intermittent hypoxia model in rat. Methods: Experiments were performed on 35 adult male Sprague-Dawley rats. Animals were randomly divided into four groups: unhandled control group (with 5 rats in it), CIH group at 9/6/3 weeks (with 10 ratsin each group). Rats in CIH group went through 8-hour intermittent hypoxia everyday, and those in control group were raising normally. After 9-week experiment, blood pressure was measured. The changes of the following indexes were observed: pathological changes of aorta and the middle aorta thickness (HE staining), the collagen of aorta wall (Masson staining). The experimental data were analyzed by SPSS 24.0 statistical software. The variance was analyzed by one-way analysis of variance, and the irregularity was selected using the calibration t test. Results: The systolic and diastolic blood pressures of the CIH9, 6, and 3 weeks groups and the control group were: (127±13) and (79±9), (124±11) and (81±7), (101±11) and (75±9), (91±10) and (65±9) mmHg (1 mmHg=0.133 kPa). The systolic blood pressure and diastolic blood pressure of the rats in the week of CIH 9 and 6 weeks were significantly higher than the control group (F=14.64, P=0.000; F=6.81, P=0.000). There was no significant difference in the mean blood pressure between the three groups of CIH and the control group. Membrane thickness in CIH9, 6 and 3 weeks and control group were: (20±2), (19±2), (14±2), (13±3) μm. Compared with the control group, the aortic pathology and thickness of the middle layer of the CIH9 and 6 weeks group were significantly thicker (F=20.24, P=0.000), but there was no significant difference between the CIH3 week group and the control group; the collagen deposition was unchanged compared with the control group. Conclusion: Intermittent hypoxia for 6 weeks or more in rats resulted in the increasement of blood pressure, morphological changes of aorta and vascular remodeling in thickened media.

Effects of Prepregnancy Body Mass Index, Weight Gain, and Gestational Diabetes Mellitus on Pregnancy Outcomes: A Population-Based Study in Xiamen, China, 2011-2018

BACKGROUND

It is unclear that how prepregnancy body mass index (BMI), gestational weight gain (GWG), and gestational diabetes mellitus (GDM) affect pregnancy outcomes in -China. Thus, we explored how BMI, GWG, and GDM affect the risks of adverse pregnancy outcomes.

METHODS

We performed a retrospective, population-based study included all births in Xiamen, China, 2011-2018. Demographic data and pregnancy outcomes of 73,498 women were acquired from the Medical Birth Registry of Xiamen. Women were categorized into groups on prepregnancy BMI and GWG in order to assess the risk of pregnancy outcomes. Multivariable logistic regression was performed to evaluate risk factors.

RESULTS

Overall, 6,982 (9.37%) women were obese, and 8,874 (12.07%) women were overweight. Obese women are more vulnerable to cesarean delivery, preterm birth, large-for-gestational age (LGA), and macrosomia (crude OR [cOR] 2.00, 1.89-2.12; 1.35, 1.20-1.51; 2.12, 1.99-2.26; 2.53, 2.25-2.86, respectively, adjusted ORs 1.73, 1.62-1.84; 1.25, 1.10-1.42; 2.03, 1.90-2.18; 2.77, 2.44-3.16, respectively). Similar results were observed in overweight women (cORs 1.49, 1.42-1.57; 1.02, 0.91-1.15; 1.60, 1.50-1.70; 2.01, 1.78-2.26, respectively). Furthermore, women who gain weight in excessive group were 1.43, 2.06, and 2.16 times to deliver cesarean, LGA, and macrosomia, respectively. Additionally, GDM women were easily subjected to cesarean section, preterm birth, LGA, low birth weight, and macrosamia (cORs 1.52, 1.55, 1.52, 1.37, 1.27, respectively).

CONCLUSIONS

Obesity prior to pregnancy, excessive GWG, and GDM were all associated with increased odds of cesarean, LGA, and macrosomia. Blood glucose and weight control before and during pregnancy are needed that may reduce the complications of pregnancy.

Automatic methods for alveolar bone loss degree measurement in periodontitis periapical radiographs

BACKGROUND AND OBJECTIVE

Periodontitis involves progressive loss of alveolar bone around the teeth. Hence, automatic alveolar bone loss measurement in periapical radiographs can assist dentists in diagnosing such disease. In this paper, we propose an automatic length-based alveolar bone loss measurement system with emphasis on a cementoenamel junction (CEJ) localization method: CEJ_LG.

METHOD

The bone loss measurement system first adopts the methods TSLS and ABLifBm, which we presented previously, to extract teeth contours and bone loss areas from periodontitis radiograph images. It then applies the proposed methods to locate the positions of CEJ, alveolar crest (ALC), and apex of tooth root (APEX), respectively. Finally the system computes the ratio of the distance between the positions of CEJ and ALC to the distance between the positions of CEJ and APEX as the degree of bone loss for that tooth. The method CEJ_LG first obtains the gradient of the tooth image then detects the border between the lower enamel and dentin (EDB) from the gradient image. Finally, the method identifies a point on the tooth contour that is horizontally closest to the EDB.

RESULTS

Experimental results on 18 tooth images segmented from 12 periodontitis periapical radiographs, including 8 views of upper-jaw teeth and 10 views of lower-jaw teeth, show that 53% of the localized CEJs are within 3 pixels deviation (∼ 0.15 mm) from the positions marked by dentists and 90% have deviation less than 9 pixels (∼ 0.44 mm). For degree of alveolar bone loss, more than half of the measurements using our system have deviation less than 10% from the ground truth, and all measurements using our system are within 25% deviation from the ground truth.

CONCLUSION

Our results suggest that the proposed automatic system can effectively estimate degree of horizontal alveolar bone loss in periodontitis radiograph images. We believe that our proposed system, if implemented in routine clinical practice, can serve as a valuable tool for early and accurate diagnosis of alveolar bone loss in periodontal diseases and also for assessing the status of alveolar bone following various types of non surgical and surgical and regenerative therapy. For overall system improvement, a more objective comparison by using transgingival bone measurement with a periodontal probe as the ground truth and enhancing the localization algorithms of these three critical points are the two major tasks.

Engineering the Structural and Electronic Phases of MoTe2 through W Substitution

MoTe₂ is an exfoliable transition metal dichalcogenide (TMD) that crystallizes in three symmetries: the semiconducting trigonal-prismatic 2H- or α-phase, the semimetallic and monoclinic 1T^'- or β-phase, and the semimetallic orthorhombic γ-structure. The 2H-phase displays a band gap of ∼1 eV making it appealing for flexible and transparent optoelectronics. The γ-phase is predicted to possess unique topological properties that might lead to topologically protected nondissipative transport channels. Recently, it was argued that it is possible to locally induce phase-transformations in TMDs, through chemical doping, local heating, or electric-field to achieve ohmic contacts or to induce useful functionalities such as electronic phase-change memory elements. The combination of semiconducting and topological elements based upon the same compound might produce a new generation of high performance, low dissipation optoelectronic elements. Here, we show that it is possible to engineer the phases of MoTe₂ through W substitution by unveiling the phase-diagram of the Mo_1-xW_xTe₂ solid solution, which displays a semiconducting to semimetallic transition as a function of x. We find that a small critical W concentration x_c ∼ 8% stabilizes the γ-phase at room temperature. This suggests that crystals with x close to x_c might be particularly susceptible to phase transformations induced by an external perturbation, for example, an electric field. Photoemission spectroscopy, indicates that the γ-phase possesses a Fermi surface akin to that of WTe₂.

Alveolar bone-loss area localization in periodontitis radiographs based on threshold segmentation with a hybrid feature fused of intensity and the H-value of fractional Brownian motion model

BACKGROUND AND OBJECTIVE

Periodontitis involves progressive loss of alveolar bone around the teeth. Hence, automatic alveolar bone-loss (ABL) measurement in periapical radiographs can assist dentists in diagnosing such disease. In this paper, we propose an effective method for ABL area localization and denote it as ABLIfBm.

METHOD

ABLIfBm is a threshold segmentation method that uses a hybrid feature fused of both intensity and texture measured by the H-value of fractional Brownian motion (fBm) model, where the H-value is the Hurst coefficient in the expectation function of a fBm curve (intensity change) and is directly related to the value of fractal dimension. Adopting leave-one-out cross validation training and testing mechanism, ABLIfBm trains weights for both features using Bayesian classifier and transforms the radiograph image into a feature image obtained from a weighted average of both features. Finally, by Otsu's thresholding, it segments the feature image into normal and bone-loss regions.

RESULTS

Experimental results on 31 periodontitis radiograph images in terms of mean true positive fraction and false positive fraction are about 92.5% and 14.0%, respectively, where the ground truth is provided by a dentist. The results also demonstrate that ABLIfBm outperforms (a) the threshold segmentation method using either feature alone or a weighted average of the same two features but with weights trained differently; (b) a level set segmentation method presented earlier in literature; and (c) segmentation methods based on Bayesian, K-NN, or SVM classifier using the same two features.

CONCLUSION

Our results suggest that the proposed method can effectively localize alveolar bone-loss areas in periodontitis radiograph images and hence would be useful for dentists in evaluating degree of bone-loss for periodontitis patients.

Teeth segmentation of dental periapical radiographs based on local singularity analysis

Teeth segmentation for periapical raidographs is one of the most critical tasks for effective periapical lesion or periodontitis detection, as both types of anomalies usually occur around tooth boundaries and dental radiographs are often subject to noise, low contrast, and uneven illumination. In this paper, we propose an effective scheme to segment each tooth in periapical radiographs. The method consists of four stages: image enhancement using adaptive power law transformation, local singularity analysis using Hölder exponent, tooth recognition using Otsu's thresholding and connected component analysis, and tooth delineation using snake boundary tracking and morphological operations. Experimental results of 28 periapical radiographs containing 106 teeth in total and 75 useful for dental examination demonstrate that 105 teeth are successfully isolated and segmented, and the overall mean segmentation accuracy of all 75 useful teeth in terms of (TP, FP) is (0.8959, 0.0093) with standard deviation (0.0737, 0.0096), respectively.

Long-term follow-up of a phase III study comparing radiotherapy with or without weekly oxaliplatin for locoregionally advanced nasopharyngeal carcinoma

BACKGROUND

Previous results from our trial showed that adding oxaliplatin to radiotherapy (RT) increased survival in patients with locoregionally advanced nasopharyngeal carcinoma (NPC) at 2 years. Here, we present the data of long-term efficacy and late toxic effects.

PATIENTS AND METHODS

Between January 2001 and January 2003, 115 Patients with nonkeratinizing/undifferentiated locoregionally advanced NPC were randomly to receive either RT alone (n = 56) or plus concurrent oxaliplatin 70 mg/m(2) weekly for six cycles (n = 59).

RESULTS

After a median follow-up of 114 months (range 18-139 months), the 5-year overall survival (OS) and metastasis-free survival (MFS) rates in the concurrent chemoradiotherapy (CCRT) group were significantly higher than those observed in the RT-alone group (OS, 73.2% versus 60.2%, P = 0.028; MFS, 74.7% versus 63.0%, P = 0.027). However, CCRT did not improve locoregional failure-free survival significantly. Subgroup analyses showed that the superiorities of CCRT mainly existed in the T3-4N0-1 stage subgroup (OS: HR = 0.394, P = 0.034). The grade 3/4 late toxic effects were similar in the two groups.

CONCLUSION(S)

The long-term follow-up data confirms the role of CCRT as a treatment of locoregionally advanced NPC. Oxaliplatin can be considered as an alternative optional therapeutic regimen for these patients due to its high efficiency and low toxic effect.

Phase II study of sorafenib in combination with cisplatin and 5-fluorouracil to treat recurrent or metastatic nasopharyngeal carcinoma

BACKGROUND

We aimed to investigate the efficacy and tolerability of sorafenib combined with cisplatin and 5-fluorouracil (5-FU) in patients with recurrent or metastatic nasopharyngeal carcinoma (NPC).

PATIENTS AND METHODS

It was a Simon two-stage designed trial. Chemotherapy-naive patients with recurrent or metastatic disease were enrolled. The regimen was sorafenib 400 mg orally b.i.d., cisplatin 80 mg/m(2) i.v. day 1, and 5-FU 1000 mg/m(2)/day CIV for 4 days, repeated every 21 days. After a maximum of six cycles of chemotherapy, patients received maintenance of sorafenib.

RESULTS

In total, 54 patients were enrolled. The objective response rate reached 77.8%, including 1 complete response and 41 partial responses. The median progression-free survival was 7.2 months (95% CI 6.8-8.4 months), and the median overall survival was 11.8 months (95% CI 10.6-18.7 months). Major toxic effects included hand-foot skin reaction, myelosuppression, and gastrointestinal (GI) reaction. The incidence of hemorrhage was 22.2%, and one patient with liver metastases died of GI bleeding. Contrast-enhanced ultrasonography was carried out in a subset of patients with liver metastases.

CONCLUSION

Combination of sorafenib, cisplatin (80 mg/m(2)) and 5-FU (3000 mg/m(2)) was tolerable and feasible in recurrent or metastatic NPC. Further randomized trials to compare sorafenib plus cisplatin and 5-FU with standard dose of cisplatin plus 5-FU in NPC are warranted.

Host-Specific Phytotoxic Polysaccharide from Apple Tissue Infected by Erwinia amylovora

A toxin isolated from apple fruit tissue infected by Erwinia amylovora is 98 percent galactose in polymeric form, 0.375 percent protein, and has an average molecular weight of approximately 165,000. Young shoots of rosaceous, but not nonrosaceous, species wilt in a manner characteristic of the disease when placed in toxin solutions with concentrations as low as 10 micrograms per milliliter. Varieties of apple and pear susceptible to Erwinia amylovora wilt in 1 to 3 hours, whereas resistant varieties display symptoms 12 to 24 hours after treatment.

Co-expression of neighboring genes in the zebrafish (Danio rerio) genome

Neighboring genes in the eukaryotic genome have a tendency to express concurrently, and the proximity of two adjacent genes is often considered a possible explanation for their co-expression behavior. However, the actual contribution of the physical distance between two genes to their co-expression behavior has yet to be defined. To further investigate this issue, we studied the co-expression of neighboring genes in zebrafish, which has a compact genome and has experienced a whole genome duplication event. Our analysis shows that the proportion of highly co-expressed neighboring pairs (Pearson’s correlation coefficient R>0.7) is low (0.24% ~ 0.67%); however, it is still significantly higher than that of random pairs. In particular, the statistical result implies that the co-expression tendency of neighboring pairs is negatively correlated with their physical distance. Our findings therefore suggest that physical distance may play an important role in the co-expression of neighboring genes. Possible mechanisms related to the neighboring genes’ co-expression are also discussed.

Multiple eruptive dermatofibromas in a patient with dermatomyositis taking prednisolone and methotrexate

Dermatofibroma (DF) is a common, benign, dermal tumor, often occurring as a single lesion. Multiple eruptive DFs are rare and usually associated with autoimmune diseases, immunosuppressant therapy, or both. We present the case of a 28-year-old woman with dermatomyositis who developed multiple eruptive DFs after undergoing methotrexate and corticosteroid treatment. Immunosuppressants such as methotrexate and corticosteroids might cause multiple eruptive DFs.

Role of polypyrimidine tract binding protein in the function of the hepatitis B virus posttranscriptional regulatory element

The hepatitis B virus posttranscriptional regulatory element (PRE) is an RNA element that increases the expression of unspliced mRNAs, apparently by facilitating their export from the nucleus. We have identified a cellular protein that binds to the PRE as the polypyrimidine tract binding protein (PTB), which shuttles rapidly between the nucleus and the cytoplasm. Mutants of the PRE with mutations in PTB binding sites show markedly decreased activity, while cells that stably overexpress PTB show increased PRE-dependent gene expression. Export of PTB from the nucleus, like PRE function, is blocked by a mutant form of Ran binding protein 1 but not by leptomycin B. Therefore, PTB is important for PRE activity and appears to function as an export factor for PRE-containing mRNAs.

Effect of MMA-g-UHMWPE grafted fiber on mechanical properties of acrylic bone cement

Ultrahigh molecular weight polyethylene (UHMWPE) fibers were treated with argon plasma for 5 min, followed by uv irradiation in methyl methacrylate (MMA)-chloroform solution for 5 h to obtain MMA-g-UHMWPE grafted fiber. The grafting content was estimated by the titration of esterification method. The grafting amount of 5280 nmol/g was the largest for the MMA concentration at 18.75 vol%. To improve the mechanical properties of acrylic bone cement, pure UHMWPE fiber and MMA-g-UHMWPE fiber were added to the surgical Simplex. P radiopaque bone cement. The mechanical properties including tensile strength, tensile modulus, compressive strength, bending strength, and bending stiffness were measured. Dynamic mechanical analysis was also performed. By comparing the effect of the pure UHMWPE fiber and MMA-g-UHMWPE grafted fiber on the mechanical properties of acrylic bone cement, it was found that the acrylic bone cement with MMA-g-UHMWPE grafted fiber had a more significant reinforcing effect than that with untreated UHMWPE fiber. This might be due to the improvement of the interfacial bonding between the grafted fibers and the acrylic bone cement matrix.

Affinity chromatographic screening of soluble combinatorial peptide libraries

Affinity chromatography using immobilized S-protein was used for the screening of affinity peptide ligands from two soluble peptide libraries. Peptide library I consisted of octamers with glycine (G) at both termini of each peptide, i.e. GXXXXXXG. The six center positions were constructed using random sequences of six L-amino acids (Y, N, F, E, V, and L). Peptide library II also consisted of octamers but with glycine and valine (V) at both termini of each peptide (GVZZZZVG). The four variable center positions of peptide library II were random sequences of 18 L-amino acids. Peptides that were retained specifically on the immobilized S-protein column were eluted by 2% acetic acid. The peptides in the acid eluate were further separated using reversed-phase HPLC. Each separated peptide fraction was collected and the peptide sequences deconvoluted by mass spectrometry (MS/MS). The screenings of peptide libraries I and II resulted in 12 and 7 affinity peptides, respectively. Eight out of the twelve peptides from peptide library I contained the clear consensus sequence NFEV. Peptide library II resulted in affinity peptides with the sequences GVNFEVVG, GVNFTVVG and GVFFEL(I)VG. The advantages and limitations of affinity chromatography in peptide library screening are discussed.

The peripheral analgesic effect of tramadol in reducing propofol injection pain: a comparison with lidocaine

BACKGROUND AND OBJECTIVES

Tramadol and metoclopramide have a local anesthetic effect similar to lidocaine following intradermal injection. When metoclopramide was retained in the venous system for 1 minute, it was found to be as effective as lidocaine in reducing propofol injection pain. Using this metoclopramide model, the effects of tramadol in reducing pain on propofol injection was investigated.

METHODS

One hundred five patients were randomly allocated to receive 50 mg tramadol (group T), 60 mg lidocaine (group L), or normal saline (group NS) as pretreatment to reduce pain on propofol injection. Following venous occlusion with a tourniquet (70 mm Hg), one of the drugs was intravenously administered. Venous retention of the drug was maintained for 1 minute. Immediately after the tourniquet release, intravenous injection of 100 mg propofol (10 mL) at a rate of 0.5 mL/s followed. Pain assessment was made after each injection.

RESULTS

Transient minor injection pain and local skin reactions were significantly greater with tramadol than with lidocaine (P < .05). Both tramadol and lidocaine significantly reduced the incidence and intensity of propofol injection pain when compared with normal saline (P < .05).

CONCLUSIONS

Using -minute retention in veins, both tramadol and lidocaine significantly reduced propofol injection pain. A local anesthetic activity is postulated.

Clearance of murine leukaemia virus from monoclonal antibody solution by a hydrophilic PVDF microporous membrane filter

Continuous cell lines (used in the manufacture of monoclonal antibodies and other therapeutic proteins) may harbour retroviral particles; nevertheless, they are deemed acceptable if the production system is validated for clearance of these contaminants. As part of a campaign to evaluate and validate appropriate virus removal methodologies for monoclonal immunoglobulin G (IgG) products, studies were undertaken with a hydrophilic polyvinylidene fluoride (PVDF) microporous membrane-the Ultipor(R) VF grade DV50 virus removal membrane. Testing conducted with murine leukaemia virus, a specific model virus used in viral validation studies to document removal of retroviruses, demonstrated a greater that 7 log clearance by the Ultipor(R) VR grade DV50 membrane. Filterability testing established the feasibility of positioning the filter at either of two different stages during manufacture. The results presented in this study demonstrate that membrane filtration through the Ultipor VF grade DV50 virus removal filter can constitute part of the purification regimen to effect removal of endogenous retrovirus-like contaminants from monoclonal IgG products.

Affinity purification of von Willebrand factor using ligands derived from peptide libraries

The chromatographic purification of vWF (von Willebrand Factor) from human plasma represents a challenge because it consists of multimers with molecular weights ranging from 0.5 to 10 million Daltons. Phage peptide library screening yielded a lead peptide (RLRSFY) that interacts with vWF. Conservative substitutions of terminal residues of the lead peptide led to a second peptide, RVRSFY, which was more efficient in the affinity chromatographic purification of vWF from protein mixtures. Adsorption isotherm measurements indicated multiple interactions between vWF and the immobilized peptide RVRSFY. Increases in peptide density on the chromatographic supports resulted in stronger association constants and higher maximum protein binding capacities. When the peptide density was lower than 32 mg/mL, there was no measurable interaction between vWF and immobilized peptide RVRSFY in HEPES buffer containing 0.5 M NaCl at pH 7. An increase in peptide density from 32 to 60 mg/mL increased the association constants from 0.9 x 10(6) to 2 x 10(6) (M-1). Divalent salts (calcium and magnesium chloride) were used to elute the retained vWF with 82.5% of the activity recovered. The interactions between vWF and the immobilized peptide RVRSFY are dominated by ionic attractions and also involve hydrophobic interactions at close contact. Finally, the purification of vWF from crude material PEG filtrate of a cryoprecipitate of human plasma is demonstrated using affinity chromatography with immobilized N-acetyl-RVRSFYK.

Isolation of endogenous modulators for the GABAA and taurine receptors

Several endogenous brain substances which inhibit [3H]muscimol binding were isolated, and one of them has been purified to apparent homogeneity. The purification involved the extraction of brain tissue with water, followed by several steps of gel filtration column chromatography and high performance liquid chromatography (HPLC). The muscimol binding inhibitor (MBI) thus obtained appeared to be homogeneous as judged from the elution profile of an HPLC column, in which a symmetrical peak was obtained when the eluate was monitored at either 220 or 280 nm. Furthermore, the MBI activity coincided with the absorption peak. The purified MBI is not gamma-amino butyric acid (GABA), beta-alanine or taurine since these amino acids are clearly separated from the MBI in the purification procedures. The MBI has no effect on benzodiazepine (BZ) binding or glutamate binding to their respective receptors. However, the MBI is a more potent inhibitor for [3H]taurine binding than that of [3H]muscimol binding. The MBI appears to be a small molecule (< 2000 Da) that is heat and acid/base stable. The chemical nature of the MBI is currently under investigation.

Aggregation and disaggregation kinetics of human blood platelets: Part II. Shear-induced platelet aggregation

A population balance equation (PBE) mathematical model for analyzing platelet aggregation kinetics was developed in Part I (Huang, P. Y., and J. D. Hellums. 1993. Biophys. J. 65: 334-343) of a set of three papers. In this paper, Part II, platelet aggregation and related reactions are studied in the uniform, known shear stress field of a rotational viscometer, and interpreted by means of the model. Experimental determinations are made of the platelet-aggregate particle size distributions as they evolve in time under the aggregating influence of shear stress. The PBE model is shown to give good agreement with experimental determinations when either a reversible (aggregation and disaggregation) or an irreversible (no disaggregation) form of the model is used. This finding suggests that for the experimental conditions studied disaggregation processes are of only secondary importance. During shear-induced platelet aggregation, only a small fraction of platelet collisions result in the binding together of the involved platelets. The modified collision efficiency is approximately zero for shear rates below 3000 s-1. It increases with shear rates above 3000 s-1 to about 0.01 for a shear rate of 8000 s-1. Addition of platelet chemical agonists yields order of magnitude increases in collision efficiency. The collision efficiency for shear-induced platelet aggregation is about an order of magnitude less at 37 degrees C than at 24 degrees C. The PBE model gives a much more accurate representation of aggregation kinetics than an earlier model based on a monodispersed particle size distribution.

Aggregation and disaggregation kinetics of human blood platelets: Part III. The disaggregation under shear stress of platelet aggregates

In the preceding two papers (1, 2), a population balance equation (PBE) mathematical model was developed, validated, and applied to the analysis of platelet aggregation kinetics under the influence of hydrodynamic shear stress. The present work involves the application of the model to the analysis of platelet reactions under shear stress in circumstances where disaggregation processes are of dominant importance: the disaggregation of aggregates formed in response to added agonists. Aggregation-disaggregation experiments were performed in the constant shear field of a rotational viscometer, and the evolution of the particle size distribution was determined by use of an electronic particle counter. The PBE model was used to simulate the experimental results. Exploratory calculations made it possible to reduce a rather complete, complex model to a more tractable form which retains the capability of simulating the experimental observations. For the experimental conditions studied, disaggregation by a splitting mechanism was found to be of dominant importance. The surface erosion mechanism can be neglected without significant impact on results. Physical reasoning confirmed by exploratory calculations showed that a discontinuous form of the breakage rate expression which incorporates a minimum friable particle size, gives significantly better results than a continuous expression. A simple step function void fraction parameter was found to be at least as successful as a more complicated, continuous function. The resulting simplified model has the potential of increasing our understanding of kinetics and mechanisms of platelet reactions, and of characterizing the state of platelet activity. Hence, it may be useful in efforts to understand thrombotic and hemostatic processes.

Aggregation and disaggregation kinetics of human blood platelets: Part I. Development and validation of a population balance method

Hydrodynamic shear stress of sufficient intensity is known to cause platelet activation and aggregation and to alter the effects of biochemical platelet agonists and antagonists. In this work, a population balance equation (PBE) model is developed for analysis of platelet aggregation and disaggregation kinetics under the influence of a shear field. The model incorporates both aggregation and disaggregation by splitting and/or erosion mechanisms. This paper, the first of a series of three, deals with the formulation, simplification, and validation of the PBE and with the estimation of parameters involved in the PBE. These population parameters include collision efficiency, void fraction (related to the particle collision diameter), and the breakage rate coefficient. The platelet particle size distribution is determined experimentally, both initially and at some later times. The PBE can then be used to match satisfactorily the observed particle histograms, by appropriate choice of parameters of the model as functions of time, platelet size, and magnitude of physical or chemical stimuli. Besides providing information on adhesive forces and on the rates of aggregation and disaggregation, these parameters infer the physical properties of platelets and platelet aggregates. These properties are of potential value in increasing our understanding of the processes involved in thrombotic disease and/or therapy. A numerical procedure for solving the PBE is validated by application to simple cases for which analytical solutions are available. The model is applied to analysis of experiments, and parameter sensitivity studies are used to order the importance of the parameters and to reduce the complexity of the model. The simplified model is shown to give good agreement with experimental observations.

Mechanistic studies of electrostatic potentials on antigen--antibody complexes for bioanalyses

A concept involving the use of antibodies conjugated with reporter molecules for the direct sensing on the subtle changes in the local electrostatic environment of antigen-antibody complexes due to the antigen binding was proposed and demonstrated. The studies including the effect of solution conditions on the extent and magnitude of the electrostatic potentials around the antigen-antibody complex and the quantitative dependence of the distance between the reporter molecule and the antigen-antibody binding site on the effectiveness of the reporter molecule for sensing the antigen-antibody binding event are presented and discussed. Basic understanding of induced changes in the electrostatic potentials on the antigen-antibody complex is essential for implementing the proposed direct sensing mechanism.

Studies on function of Hb Jianghua [beta 120 (GH3) Lys----Ile]

Hemoglobin Jianghua (Hb Jianghua) is a new fast--moving hemoglobin variant found in China, being named after the county where it was detected. Having its primary structure analysed, we report in this paper the results of studies on its function. The absorption spectrum, response to allosteric effectors and oxygen equilibrium of the chromatographically purified Hb Jianghua showed its characteristics similar to those of purified Hb A. Its alkaline Bohr effect was normal. This indicates that a substitution of isoleucine for the 120th lysine residue of the beta chain had no significant influence upon the function of Hb molecule.

The occurrence of phytoferritin and its relationship to effectiveness of soybean nodules

Polyacrylamide gel electrophoresis and electron microscopy revealed that accumulation of iron-protein in soybean nodules is influenced by nodule age, mutation in bradyrhizobia, and rhizobial/bradyrhizobial strain-soybean cultivar interactions. Iron-protein concentrations (micrograms per milligram protein) were inversely related to heme concentrations (nanomoles per milligram protein), with correlation coefficients (r values) ranging from -0.98 in young nodules to -0.83 in mature ones. Bradyrhizobium japonicum symbiotic mutants HS 129 and HS 145 (Nod(+) Fix(-)) produced nodules high in iron-protein. Electrophoresis of homogenate prepared from nodules on Lee 68 produced by B. japonicum HS 129 yielded two different forms of the iron-proteins, 570 and 600 kilodaltons. The 570 kilodalton iron-protein isolated by preparative polyacrylamide gel electrophoresis behaved like horse-spleen-ferritin in responses to iron-stains, heat stability, ultraviolet absorption spectrum, iron unloading and reloading, and characteristic appearance in electron micrographs. These properties led to the conclusion that the 570 kilodalton iron-protein is phytoferritin. The nodule phytoferritin differed from horse-spleen-ferritin in electrophoretic mobility, serological properties, and molecular size and was distinct from most other known phytoferritins in that it was composed of different subunit types.

Ultrastructure of the cell wall of Erwinia amylovora

Thin sectioned cells of Erwinia amylovora revealed two electron-dense layers in their walls when fixed at 24 to 27 C and three when fixed at 4 C.

Morphology and ultrastructure of normal rod-shaped and filamentous forms of Erwinia amylovora

Filamentous cells of Erwinia amylovora were usually 3 to 35 times longer than the normal rod-shaped ones, and only the former produced minicells.