[Research progress on anti-inflammatory effects of plant-derived cannabinoid type 2 receptor modulators]

Excessive and persistent inflammatory responses are a potential pathological condition that can lead to diseases of various systems, including nervous, respiratory, digestive, circulatory, and endocrine systems. Cannabinoid type 2 receptor(CB2R) belongs to the G protein-coupled receptor family and is widely distributed in immune cells, peripheral tissues, and the central nervous system. It plays a role in inflammatory responses under various pathological conditions. The down-regulation of CB2R activity is an important marker of inflammation and and CB2R modulators have been shown to have anti-inflammatory effects. This study explored the relationship between CB2R and inflammatory responses, delved into its regulatory mechanisms in inflammatory diseases, and summarized the research progress on CB2R modulators from plants other than cannabis, including plant extracts and monomeric compounds, in exerting anti-inflammatory effects. The aim is to provide new insights into the prevention and treatment of inflammatory diseases.

NR0B1 suppresses ferroptosis through upregulation of NRF2/c-JUN-CBS signaling pathway in lung cancer cells

Ferroptosis has demonstrated significant potential in treating radiochemotherapy-resistant cancers, but its efficacy can be affected by recently discovered ferroptosis suppressors. In this study, we discovered that NR0B1 protects against erastin- or RSL3-induced ferroptosis in lung cancer cells. Transcriptomic analysis revealed that NR0B1 significantly interfered with the expression of 12 ferroptosis-related genes, and the expression level of NR0B1 positively correlated with that of c-JUN, NRF2, and CBS. We further revealed that NR0B1 suppression of ferroptosis depended on the activities of c-JUN, NRF2, and CBS. NR0B1 directly promoted the expression of NRF2 and c-JUN and indirectly upregulated CBS expression through enhancing NRF2 and/or c-JUN transcription. Moreover, we showed that NR0B1 depletion restrained xenograft tumor growth and facilitated RSL3-induced ferroptosis in the tumors. In conclusion, our findings uncover that NR0B1 suppresses ferroptosis by activating the c-JUN/NRF2-CBS signaling pathway in lung cancer cells, providing new evidence for the involvement of NR0B1 in drug resistance during cancer therapy.

[Impact of different diagnostic criteria for assessing mild micro-hepatic encephalopathy in liver cirrhosis: an analysis based on a prospective, multicenter, real-world study]

Objective: To compare the differences in the prevalence of mild micro-hepatic encephalopathy (MHE) among patients with cirrhosis by using the psychometric hepatic encephalopathy score (PHES) and the Stroop smartphone application (Encephal App) test. Methods: This prospective, multi-center, real-world study was initiated by the National Clinical Medical Research Center for Infectious Diseases and the Portal Hypertension Alliance and registered with International ClinicalTrials.gov (NCT05140837). 354 cases of cirrhosis were enrolled in 19 hospitals across the country. PHES (including digital connection tests A and B, digital symbol tests, trajectory drawing tests, and serial management tests) and the Stroop test were conducted in all of them. PHES was differentiated using standard diagnostic criteria established by the two studies in China and South Korea. The Stroop test was evaluated based on the criteria of the research and development team. The impact of different diagnostic standards or methods on the incidence of MHE in patients with cirrhosis was analyzed. Data between groups were differentiated using the t-test, Mann-Whitney U test, and χ (2) test. A kappa test was used to compare the consistency between groups. Results: After PHES, the prevalence of MHE among 354 cases of cirrhosis was 78.53% and 15.25%, respectively, based on Chinese research standards and Korean research normal value standards. However, the prevalence of MHE was 56.78% based on the Stroop test, and the differences in pairwise comparisons among the three groups were statistically significant (kappa = -0.064, P < 0.001). Stratified analysis revealed that the MHE prevalence in three groups of patients with Child-Pugh classes A, B, and C was 74.14%, 83.33%, and 88.24%, respectively, according to the normal value standards of Chinese researchers, while the MHE prevalence rates in three groups of patients with Child-Pugh classes A, B, and C were 8.29%, 23.53%, and 38.24%, respectively, according to the normal value standards of Korean researchers. Furthermore, the prevalence rates of MHE in the three groups of patients with Child-Pugh grades A, B, and C were 52.68%, 58.82%, and 73.53%, respectively, according to the Stroop test standard. However, among the results of each diagnostic standard, the prevalence of MHE showed an increasing trend with an increasing Child-Pugh grade. Further comparison demonstrated that the scores obtained by the number connection test A and the number symbol test were consistent according to the normal value standards of the two studies in China and South Korea (Z = -0.982, -1.702; P = 0.326, 0.089), while the other three sub-tests had significant differences (P < 0.001). Conclusion: The prevalence rate of MHE in the cirrhotic population is high, but the prevalence of MHE obtained by using different diagnostic criteria or methods varies greatly. Therefore, in line with the current changes in demographics and disease spectrum, it is necessary to enroll a larger sample size of a healthy population as a control. Moreover, the establishment of more reliable diagnostic scoring criteria will serve as a basis for obtaining accurate MHE incidence and formulating diagnosis and treatment strategies in cirrhotic populations.

[Survey of Helicobacter pylori levofloxacin and clarithromycin resistance rates and drug resistance genes in Ningxia, 2020-2022]

Objective: To explore the rate of Helicobacter pylori (Hp) resistance to levofloxacin and clarithromycin and the common mutation patterns of resistance genes in Ningxia, and to assess the concordance between phenotypic resistance and genotypic resistance. Methods: Cross-sectional study. Patients diagnosed with Hp infection in 14 hospitals in Ningxia region from February 2020 to May 2022 were retrospectively selected. Hp strains were isolated from gastric biopsy specimens of Hp-infected patients and subjected to phenotypic drug sensitivity testing and detection of resistance genes to analyze the rate of Hp resistance to levofloxacin and clarithromycin and the common mutation patterns of resistance genes in Ningxia region; and the concordance rate and Kappa concordance test were used to assess the concordance between phenotypic resistance and genotypic resistance. Results: A total of 1 942 Hp strains were isolated and cultured, and among the infections, 1 069 cases (55.0%) were male and 873 cases (45.0%) were female, aged (50.0±12.5) years (15-86 years). The rates of Hp resistance to levofloxacin and clarithromycin in Ningxia were 42.1% (818/1 942) and 40.1% (779/1 942), respectively, and the rate of dual resistance to both was 22.8% (443/1 942). The rate of resistance to levofloxacin and clarithromycin of Hp strains from female patients was higher than in male patients (levofloxacin: 50.4%(440/873) vs 35.4%(378/1 069); clarithromycin: 44.4%(388/873) vs 36.6%(391/1 069), both P<0.001). Among the GyrA gene mutations associated with levofloxacin resistance, the differences in mutation rate of amino acid at positions 87 and 91 were statistically significant in both drug-resistant and sensitive strains(both P<0.001), except for Asn87Thr. Hp strains were statistically significant for levofloxacin (Kappa=0.834, P<0.001) and clarithromycin (Kappa=0.829, P<0.001) had good concordance in resistance at the phenotypic and genotypic levels. Conclusion: The resistance of Hp to levofloxacin and clarithromycin in Ningxia region is severe, and there is good consistency between genotypic and phenotypic resistance.

[Status of HVPG clinical application in China in 2021]

Objective: The investigation and research on the application status of Hepatic Venous Pressure Gradient (HVPG) is very important to understand the real situation and future development of this technology in China. Methods: This study comprehensively investigated the basic situation of HVPG technology in China, including hospital distribution, hospital level, annual number of cases, catheters used, average cost, indications and existing problems. Results: According to the survey, there were 70 hospitals in China carrying out HVPG technology in 2021, distributed in 28 provinces (autonomous regions and municipalities directly under the central Government). A total of 4 398 cases of HVPG were performed in all the surveyed hospitals in 2021, of which 2 291 cases (52.1%) were tested by HVPG alone. The average cost of HVPG detection was (5 617.2±2 079.4) yuan. 96.3% of the teams completed HVPG detection with balloon method, and most of the teams used thrombectomy balloon catheter (80.3%). Conclusion: Through this investigation, the status of domestic clinical application of HVPG has been clarified, and it has been confirmed that many domestic medical institutions have mastered this technology, but it still needs to continue to promote and popularize HVPG technology in the future.

[Clinical effects of free transplantation of expanded thoracodorsal artery perforator flaps in reconstructing cervical cicatrix contracture deformity after burns]

Objective: To explore the clinical effects of free transplantation of expanded thoracodorsal artery perforator flaps in reconstructing cervical cicatrix contracture deformity after burns. Methods: A retrospective observational study was conducted. From May 2018 to April 2021, 11 patients with cervical cicatrix contracture deformity after burns who met the inclusion criteria were admitted to the First Affiliated Hospital of Air Force Medical University, including 3 males and 8 females, aged 5 to 46 years, with a course of cervical cicatrix contracture deformity of 5 months to 8 years. The degree of cervical cicatrix contracture deformity was degree Ⅰ in one patient, degree Ⅱ in nine patients, and degree Ⅲ in one patient. In the first stage, according to the sizes of neck scars, one rectangular skin and soft tissue expander (hereinafter referred to as expander) with rated capacity of 200 to 600 mL was placed in the back. The expansion time was 4 to 12 months with the total normal saline injection volume being 3.0 to 3.5 times of the rated capacity of expander. In the second stage, free expanded thoracodorsal artery perforator flaps with areas of 10 cm×7 cm to 24 cm×13 cm were cut out to repair the wounds with areas of 9 cm×6 cm to 23 cm×12 cm which was formed after cervical cicatectomy. The main trunk of thoracodorsal artery and vein were selected for end-to-end anastomosis with facial artery and vein, and the donor sites were directly closed. The survival of flaps and healing of flap donor sites were observed on the 14th day post surgery. The appearances and cicatrix contracture deformity of the flaps, recovery of cervical function, and scar hyperplasia of donor sites were followed up. Results: On the 14th day post surgery, the flaps of ten patients survived, while ecchymosis and epidermal necrosis occurred in the center of flap of one patient and healed 2 weeks after dressing change. On the 14th day post surgery, the flap donor sites of 11 patients all healed well. During the follow-up of 6-12 months post surgery, the flaps of ten patients were similar to the skin around the recipient site in texture and color, while the flap of one patient was slightly swollen. All of the 11 patients had good recovery of cervical function and no obvious scar hyperplasia nor contracture in the flaps or at the donor sites. Conclusions: Application of expanded thoracodorsal artery perforator flaps can restore the appearance and function of the neck, and cause little damage to the donor site in reconstructing the cervical cicatrix contracture deformity after burns, which is worthy of clinical reference and application.

[Research progress on natural cannabinoid receptor type 2( CB2R)regulators and their effects on bone metabolism]

Cannabinoid receptor type 2( CB2 R),a member of the G protein-coupled receptor( GPCR) superfamily,has a variety of biological activities,such as regulating pain response,resisting inflammation and fibrosis,and mediating bone metabolism. Some CB2 R regulators exhibit a good regulatory effect on bone metabolism. Cannabinoids in Cannabis sativa can cause psychoactive effects despite various pharmacological actions they exerted by targeting CB2 R. Therefore,it is of great significance to discover CB2 R regulators in non-Cannabis plants for finding new lead compounds without psychoactive effects and elucidating the action mechanism of plant drugs. The present study clarifies the discovery,structure,and physiological functions of CB2 R,especially its regulatory effects on bone metabolism,summarized CB2 R regulators extracted from non-Cannabis plants,and systematically analyzes the regulatory effects of CB2 R regulators on bone metabolism in animals,osteoblasts,and osteoclasts,to provide a scientific basis for the discovery of new CB2 R regulators and the development of anti-osteoporotic drugs.

[Prevalence and risk factors of allergic rhinitis: a Meta-analysis]

Objective:To clarify the morbidity and risk factors of allergic rhinitis (AR) in China so as to provide scientific basis for prevention of AR in the relevant populations.Method:Pubmed,Embase,Web of science,Cochrane Library,CNKI,VIP,Wanfang Data,CBM databases were searched for associated studies. The prevalence and risk factors of AR in China were retrieved from individual studies and the pooled estimates generated by R3.2.3 software.Result:Thirty-one cross-sectional studies were included in the Meta-analysis. The results indicated that the incidences of AR in Chinese children were 15.79%(95%CI 15.13-16.45).The highest prevalence is 17.20% in central China,the lowest is 13.94% in eastern China. The incidences of AR in Chinese adult were 13.26% (95%CI 12.05-14.47).The highest prevalence is 15.45% in southern China,the lowest is 10.93% in southwestern China. The pooled odds ratio (OR) values of family history (5.40),dust exposure history (2.04),drug allergy history (2.83),history of asthma(4.45),environmental tobacco smoking(ETS)(2.00),water damage (1.50),upholstering(1.41),pollen allergy(17.18),molds(1.31),keeping pets (1.29),cockroach (1.69).Conclusion:A study on the epidemic tendency of AR in China showed the morbidity of AR in Chinese children is higher than adult. Moreover,prevalence vary from region to region. Eleven kinds of risk factors mentioned above play imperative roles in the pathogenesis of AR. The early interventions which are associated with risk factors should be implemented in AR.

Characterization of tissue chromogranin A (CgA) immunostaining and clinicohistopathological changes for the 125 Chinese patients with primary small cell carcinoma of the esophagus

The rarity of primary small cell carcinoma of the esophagus (PSCE) has limited the clinical feature and survival analysis with large sample size. Tissue chromogranin A (CgA) protein expression has been reported to be a useful biomarker for diagnosing PSCE. Interestingly, recent studies have indicated tissue CgA as a significant prognostic marker in multiple human cancers, but without PSCE. The present study, thus, was undertaken to characterize the clinicopathological changes and to evaluate the associations of tissue CgA expression with clinical response on Chinese PSCE patients. All the 125 PSCE patients were enrolled from our 500,000 esophageal and gastric cardia carcinoma databases (1973-2015), constructed by the cooperative team from more than 700 hospitals in China and established by Henan Key Laboratory for Esophageal Cancer Research in Henan, China. Immunostaining for CgA showed that CgA was mainly located in cytoplasm of tumor cells with a positive detection rate of 44.6%. The CgA positive expression rate in PSCE at lower segment of the esophagus (72.2%) was higher than that at middle segment (41.5%) (P = 0.001). However, CgA protein expression did not correlated with lymph node metastasis (P = 0.767), TNM staging (P = 0.740), tumor invasion (P = 0.253), gender (P = 0.262), and age (P = 0.250). Multivariate survival analysis showed that the patients with higher CgA protein expression had a superior long survival than those without CgA expression (P = 0.037). The clinicopathological analysis showed that PSCE occurred predominantly in male (M:F = 1.9:1) at the middle segment (68%) of the esophagus. Histologically, 89.6% were pure PSCE and 10.4% were mixed type with either squamous cell carcinoma (8%) or adenocarcinoma (2.4%). It was noteworthy that, with the in-depth invasion from T1 to T2 and T3, the positive lymph node metastasis rate increased dramatically from 38%, 56% to 74%, respectively. The survival rates of 1-, 2-, 3-, and 5-year were 64%, 35%, 18%, and 7%, respectively. The Kaplan-Meier survival analysis showed that the young patients (≤60 years) had longer survival than the elderly (P = 0.011). Interestingly, multivariate survival analysis revealed that the patients with mixed PSCE had a significantly better survival than those with pure PSCE (P = 0.015). Furthermore, the median survival time for the patients with and without lymph node metastasis was 1.16 and 2.03 years, respectively. But, the difference was not significant (P = 0.143). Univariate analysis did not show any survival influence by gender, tumor location, tumor invasion depth, and TNM staging. It was noteworthy that, of the 13 early PSCE patients (T1N0M0), only one patient had more than 5 year survival, the others died with less than one or two year (65%). The present study indicates that the PSCE is of badly worsen prognosis, even in the pathological early stage. Tissue CgA protein expression is a promising maker not only for diagnosis and also for prognosis. Further assessment is needed to establish specific PSCE pathological staging system and to clarify the mechanisms of CgA protein in PSCE progression and prognosis.

[Investigation of pregestational diabetes mellitus in 15 hospitals in Guangdong province]

Objective: To investigate the morbidity, diagnostic profile and perinatal outcome of pregestational diabetes mellitus (PGDM) in 15 hospitals in Guangdong province. Methods: A total of 41 338 women delivered in the 15 hospitals during the 6 months, 195 women with PGDM (PGDM group) and 195 women with normal glucose test result (control group) were recruited from these tertiary hospitals in Guangdong province from January 2016 to June 2016. The morbidity and diagnostic profile of PGDM were analyzed. The complications during pregnancy and perinatal outcomes were compared between the two groups. In the PGDM group, pregnancy outcomes were analyzed in women who used insulin treatment (n=91) and women who did not (n=104). Results: (1) The incidence of PGDM was 0.472%(195/41 338). Diabetes mellitus were diagnosed in 59 women (30.3%, 59/195) before pregnancy, and 136 women (69.7%,136/195) were diagnosed as PGDM after conceptions. Forty-six women (33.8%) were diagnosed by fasting glucose and glycohemoglobin (HbA1c) screening. (2) The maternal age, pre-pregnancy body mass index (BMI) , prenatal BMI, percentage of family history of diabetes, incidence of macrosomia, concentration of low density lipoprotein were significantly higher in PGDM group than those in control group (all P<0.05). Women in PGDM group had significantly higher HbA1c concentration ((6.3±1.3)% vs (5.2±0.4)%) , fasting glucose [(6.3±2.3) vs (4.8±1.1) mmol/L], oral glucose tolerance test (OGTT) -1 h glucose ((12.6±2.9) vs (7.1±1.3) mmol/L) and OGTT-2 h glucose [(12.0±3.0) vs (6.4±1.0) mmol/L] than those in control group (P<0.01). (3) The morbidity of preterm births was significantly higher (11.3% vs 1.0%, P<0.01), and the gestational age at delivery in PGDM group was significantly smaller [(37.6±2.3) vs (39.2±1.2) weeks, P<0.01]. Cesarean delivery rate in the PGDM group (70.8% vs 29.7%) was significantly higher than the control group (P<0.01). There was significantly difference between PGDM group and control in the neonatal male/female ratio (98/97 vs 111/84, P=0.033). The neonatal birth weight in PGDM group was significantly higher ((3 159±700) vs (3 451±423) g, P<0.01) . And the incidence of neonatal hypoglycemia in the PGDM group was higher than the control group (7.7% vs 2.6%, P=0.036). (4) In the PGDM group, women who were treated with insulin had a smaller gestational age at delivery [(36.9±2.9) vs (37.9±2.5) weeks, P<0.01], and the neonates had a higher neonatal ICU (NICU) admission rate (24.2% vs 9.6%, P<0.01). Conclusions: The morbidity of PGDM in the 15 hospitals in Guangdong province is 0.472%. The majority of PGDM was diagnosed during pregnancy; HbA1c and fasting glucose are reliable parameters for PGDM screening. Women with PGDM have obvious family history of diabetes and repeated pregnancy may accelerate the process of diabetes mellitus. Women with PGDM have higher risk for preterm delivery and neonatal hypoglycemia. Unsatisfied glucose control followed by insulin treatment may increase the need for NICU admission.

[High glucose promotes gap junctional communication in cultured neonatal cardiac fibroblasts via AMPK activation]

Cardiac fibroblasts are known to be essential for adaptiveresponses in the patho- genesis of cardiovascular diseases, and increased intercellular communication of myocardial cells and cardiac fibroblasts acts as a crucial factor in maintaining the functional integrity of the heart. AMP-activated kinase (AMPK) is a key stress signaling kinase, which plays an important role in promoting cell survival and improving cell function. However, the underlying link between AMPK and gap junctional communication (GJIC) is still poorly understood. In this study, a connection between AMPK and GJIC in high glucose-mediated neonatal cardiac fibroblasts was assessed using fibroblast migration, measurement of dye transfer and connexin43 (Cx43) expression. 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR) and Compound C (CC) were used to regulate AMPK activity. The levels of cell migration and Cx43 protein expression in neonatal cardiac fibroblasts increased during high glucose treatment, accompanied by developed dye transfer. In addition, high glucose induced abundant phosphorylation of AMPK. Suppression of AMPK phosphorylation using CC reduced dye transfer, cell migration and Cx43 protein expression in neonatal cardiac fibroblasts, whereas the activation of AMPK using AICAR mimicked the high glucose-mediated cell migration, Cx43 protein expression and dye transfer enhancement. AMPK appears to participate in regulating GJIC in high-glucose-treated neonatal cardiac fibroblasts, including cell migration, dye transfer, Cx43 expression and distribution.

Targeting role of glioma stem cells for glioblastoma multiforme

Glioblastoma multiforme (GBM) is known to be the most common and lethal malignant primary brain tumor. Despite vigorous basic and clinical studies over the past decades, the prognosis of patients with GBM has remained dismal. The fundamental problem with these malignancies occurs due to tumor cells' highly infiltrative nature, precluding a complete surgical resection, and a productive or acquired resistance to cytotoxic therapy. Recent studies demonstrated that GBMs exhibited remarkable cellular heterogeneity and hierarchy containing self-renewing glioma stem cells (GSCs). The malignant growth of GBM can be propagated and sustained by GSCs that are endowed with highly efficient clonogenic and tumor initiation capacities. GSCs can be identified with technical support and are responsible for the invasive potential and recurrence of GBMs. They share core signaling pathways with normal neural stem cells, but also display critical distinctions that provide important clues for useful therapeutic targets. Therefore, targeting GSCs becomes priorities for the development of novel therapeutic paradigms. Herein, we reviewed the existing and promising targeting therapies for GSCs which could effectively inhibit the tumor invasion, proliferation and recurrence of GBMs. Significant features of GSCs, such as invasive growth pattern, angiogenic potential, resistance to traditional therapy and differentiation, are important therapeutic targets. More promising strategies should target GSCs themselves by taking advantages of highthroughput technologies and dissecting the intrinsic molecular nature of GSCs. Novel chemical medicines targeting these GSCs may represent one of the most important directions. Hopefully, this could shed a light on the path we are going to.

Serum Levels of Calcitonin Gene-Related Peptide and Substance P are Decreased in Patients with Diabetes Mellitus and Coronary Artery Disease

OBJECTIVE: This study evaluated serum levels of the neuropeptides calcitonin gene-related peptide (CGRP) and substance P (SP) in coronary artery disease (CAD) patients with and without a history of diabetes mellitus (DM). METHODS: Patients undergoing coronary angiography for suspected myocardial ischaemia were divided into four groups depending on their clinical status: control group (no CAD or DM; n = 44), DM group (DM without CAD; n = 46), CAD group (stable CAD without DM; n = 44) and DM + CAD group (stable CAD with DM; n = 50). Serum levels of CGRP and SP were determined using radioimmunoassays. RESULTS: CGRP and SP levels in the DM and CAD groups were significantly lower than in the control group. The lowest levels of CGRP and SP were observed in the DM + CAD group. There were no significant differences in CGRP and SP levels between the DM group and the CAD group. CONCLUSION: CGRP and SP may have a role in the pathogenesis of CAD in patients with diabetes.

Du-Zhong (Eucommia ulmoides Oliv.) cortex extract prevent OVX-induced osteoporosis in rats

Du-Zhong, rich in polyphenolic compounds such as lignans, phenolic acid, and flavonoids, is a kidney-tonifying herbal medicine with a long history of safe use for treatment of bone fractures and joint diseases in China. In the present study, we examined whether Du-Zhong cortex extract (DZCE) with graded doses exerted its preventive effects on estrogen deficiency-induced osteoporosis. Eighty 3-month-old female Sprague-Dawley rats were used and randomly assigned into sham-operated group (Sham) and five ovariectomy (OVX) subgroups, i.e. OVX with vehicle (OVX); OVX with 17alpha-ethinylestradiol (E(2), 25 microg/kg/day); OVX with DZCE of graded doses (100, 300, or 500 mg/kg/day). Daily oral administration of DZCE or E(2) started on week 4 after OVX for 16 weeks. Treatment with DZCE at higher doses (300 or 500 mg/kg/day) was found to be able to significantly prevent OVX-induced decrease in biomechanical quality of femur such as maximum stress and Young's modulus. The mechanical changes were associated with the prevention of a further bone mineral density (BMD) decrease or even with some improvements in microarchitecture. DZCE dose-dependently inhibited total BMD decrease in the femur caused by OVX, which was accompanied by a significant decrease in skeletal remodeling, as was evidenced by the decreased levels of the bone turnover markers osteocalcin (OC), alkaline phosphatese (ALP), deoxypyridinoline (DPD), and urinary Ca and P excretions. muCT analysis of the femoral metaphysis showed that DZCE at the highest doses (500 mg/kg/day) significantly prevents decrease in bone volume/tissue volume (BV/TV), connect density (Conn.D), trabecula number (Tb.N) and trabecula thickness (Tb.Th), and increase in trabecula separation (Tb.Sp) and structure model index (SMI) in OVX rats. We conclude that 16 weeks of DZCE treatment improves bone biomechanical quality through modifications of BMD, and trabecular microarchitecture without hyperplastic effect on uterus, and it might be a potential alternative medicine for treatment of postmenopausal osteoporosis.

A Novel Bursting Mechanism of Type A Neurons in Injured Dorsal Root Ganglia

Using intracellular recording in vivo, the bursting behaviors were investigated in the neurons of chronically compressed dorsal root ganglia of the adult rat. In most cases, the first spike of a burst emerged from amplitude-increasing damped subthreshold membrane potential oscillation (SMPO) and the discharge terminated by an amplitude-decreasing damped SMPO. The rhythms of these bursting behaviors are all irregular. Since some researchers found that the stochastic dynamics can also produce similar bursting pattern, the deterministic dynamics of interevent interval (IEI) series obtained from raw membrane potential recording was detected by extraction of the hierarchy of unstable periodic orbits (UPOs) in the windowed IEI series. The results showed a number of statistically significant UPOs of order-one, order-two, and order-three. These orbits form a complex but predictable lattice of regions in which the dynamics of the bursting occurrence is deterministic. Based on a complete classification scheme, the investigated bursting can be depicted by the elliptic bursting dynamics. The significance of the finding that a neuron in the injured dorsal root ganglion has such dynamics is also discussed.

Effects of homocysteine on number and activity of endothelial progenitor cells from peripheral blood

The aim of this study is to investigate whether homocysteine (Hcy) has influences on endothelial progenitor cells (EPCs) number and activity. Total mononuclear cells (MNCs) were isolated from peripheral blood by Ficoll density gradient centrifugation, and then the cells were plated on fibronectin-coated culture dishes. After 7 d cultured, attached cells were stimulated with Hcy (to make a series of final concentrations: 10, 50, 100 and 200 micromol/l) or vehicle control for the respective time points (6, 12, 24 and 48 h). EPCs were characterized as adherent cells double positive for DiLDL uptake and lectin binding by direct fluorescent staining under a laser scanning confocal microscope. EPCs proliferation, migration and in vitro vasculogenesis activity were assayed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, modified Boyden chamber assay and in vitro vasculogenesis kit, respectively. EPCs adhesion assay was performed by replating those on fibronectin-coated dishes, and then adherent cells were counted. Incubation of isolated human MNCs with Hcy dose and time dependently decreased the number of EPCs, maximum at 200 micromol/l, 24 h (approximately 50% reduction, P < 0.01). In addition, Hcy dose and time dependently impaired EPC proliferative, migratory, adhesive and in vitro vasculogenesis capacity. In conclusion, hyperHcy may induce the reduction of EPCs with decreased functional activity.

Subthreshold membrane potential oscillations of type A neurons in injured DRG

An abundance of subthreshold membrane potential oscillations (SMPOs) at resting potential was observed in the neurons of chronically compressed dorsal root ganglia (DRG) using intracellular recording in vivo. Out of 386 neurons, 63 type A neurons displayed SMPOs. Three types of SMPOs were distinguished based on their characterizations of oscillation: (1) A regular pattern of SMPO emerged consistently with a mean frequency of 86 Hz and mean amplitudes of 3.3 mV. (2) A spindle-like pattern of SMPO was denominated by a spindle alteration of its amplitude. (3) An irregular pattern of SMPO had no rule on its change of amplitude and frequency. Compared with normal DRG neurons and injured DRG neurons but without SMPO, the injured DRG neurons with SMPO had the lowest spike rheobase, in accordance with the detection of spike accommodation. No significant differences among the three groups can be found in either membrane potential or input resistance. Further observation showed that the spontaneous discharge of hyperexcitable neurons usually occurred on the depolarizing phase of oscillations. In addition, the regular pattern of SMPO was based on the period and integer multiple patterns of spontaneous discharges. The spindle-like pattern of SMPO contributed to spontaneous bursting discharge. The irregular pattern of SMPO had a striking relation with irregular spontaneous discharge. The results show that neurons with SMPO in injured DRG have a higher excitability than those without SMPO, and that the SMPO underlie the patterns of spontaneous discharges, suggesting that SMPO is the basic electrophysiological change of hyperexcitable neurons.

Subthreshold membrane oscillations underlying integer multiples firing from injured sensory neurons

Integer multiples firing (IMF), a special temporal pattern of firing, was recently observed in spontaneous discharge from injured dorsal root ganglion (DRG) neurons. To investigate the mechanism underlying IMF, the injured DRG neurons of rat were recorded intracellulary. Of 64 recorded A-neurons discharging spontaneously, eight fired spikes in the IMF pattern. Interspike interval (ISI) time series of IMF showed a structure of distinct bands on scatter map. Regular subthreshold membrane oscillations (SMOs) with relatively stable amplitude and frequency were observed on all eight IMF neurons. IMF could be induced from the neurons in periodic firing by local application of tetrodotoxin (TTX), a Na+ channel antagonist. During this process, the amplitude of SMOs varied markedly. Some SMOs were below action potential threshold so that they did not trigger spikes. Nor did some SMOs, though their amplitude were obviously beyond the threshold measured from nearby spikes. The results indicate that regular SMOs existent in injured DRG A-neurons underlie IMF, and the TTX-induced transformation of firing pattern from periodic to integer multiples may occur in two ways: decreasing the amplitude of SMOs and/or elevating action potential threshold.

[Sympathetic-sensory coupling in neuropathic pains]

Peripheral tissue and nerve injury lead to chronic pain symptoms, including spontaneous pain, allodynia and hyperalgesia. Sympathetic nervous system involves in pathological changes above, either through development of abnormal sympathetic function or through its effects on abnormally functioning afferent nerves, thereby to cause many neuropathic pains. This review focuses on the progress at present of sympathetic-sensory coupling and its receptors, intracellular and neural mechanisms.

Adrenergic sensitivity of neurons with non-periodic firing activity in rat injured dorsal root ganglion

In this study, we compared the sensitivity of non-periodically and periodically active neurons in chronically compressed dorsal root ganglion in rats to norepinephrine and sympathetic stimulation. Forty-nine of 58 (84.5%) neurons with non-periodic activity showed responses to norepinephrine, whereas only five of 48 (10.4%) neurons with periodic activity displayed any response. The dose-response relationship of norepinephrine to the irregular burst pattern neurons shifted towards the left significantly compared to that of the periodic activity neurons. Responses to norepinephrine became apparent in eight neurons after their periodic firing activity was transformed into the non-periodic firing activity through the increase in Ca(2+). Changes in the time-response curves indicate a higher sensitivity of irregular burst pattern neurons to sympathetic stimulation than the periodic activity neurons. Finally, deterministic dynamics contained within the interburst interval series for non-periodic activity were identified. From these results, we suggest that the non-periodic activity neurons have a higher adrenergic sensitivity than those displaying periodic activity, and that this sensitivity may depend on the deterministic chaos within its firing dynamic system.

[Relationship between the sensitivity to tetraethylammonium and firing patterns of injured dorsal root ganglion neurons]

In order to study the relationship between the firing patterns of injured dorsal root ganglion (DRG) neurons of rat and their sensitivity to tetraethylammonium (TEA), spontaneous activities from single fibers of chronically compressed DRG neurons were recorded. Two patterns of spontaneous activity were found: periodic pattern and non-periodic pattern. These two types of neurons showed different sensitivity to TEA with 27.3% in periodic and 93.2% in non-periodic firing neurons responding to TEA (2 mmol/L) (P<0.01). The responses to TEA of different concentrations were greater in the non-periodic firing neurons than in the periodic firing ones (P<0.01). The responses to TEA became apparent in 5 neurons after their periodic firing pattern was transformed into non-periodic firing pattern through an increase in Ca(2+). The non-periodic interburst interval of the bursting discharge decreased significantly while the periodic burst interspike interval had no response to TEA. The unstable period orbits were found in bursting discharge, indicating deterministic chaos during bursting discharge. It is concluded that non-periodic firing neurons with chaos are more sensitive to TEA than periodic firing neurons.

Detection of determinism within time series of irregular burst firing from the injured sensory neuron

Irregular burst firing is spontaneously generated by rat dorsal root ganglion neuron after chronic compression. To investigate the time series of burst firing, we recorded interspike intervals (ISIs) of single-unit firing in vitro and processed the ISIs to obtain interevent intervals (IEIs). Then, two non-linear methods were applied to detect deterministic dynamic behaviors in IEI series. No evidence for the existence of determinism was found with non-linear prediction method. Using unstable periodic orbit identification method, significant period-1 orbits were identified in all 10 data, period-2 orbits in eight, and period-3 orbits in six. The results indicate that there exist significant deterministic behaviors in the time series of irregular burst firing from the injured sensory neuron.

Studies of detrusor-sphincter synergia and dyssynergia during micturition in rats via fractional Brownian motion

In normal humans, the bladder is supposed to empty by a synergistic contraction of the detrusor and relaxation of the sphincter during micturition. By contrast, suprasacral spinal cord injury (SCI) patients usually will have both of them contract simultaneously and result in the so-called detrusor-sphincter dyssynergia. In this study, the cystometrograms of the detrusor and the electromyograms of external urethral sphincter of intact and SCI female Wistar rats are used to investigate the detrusor-sphincter synergia and dyssynergia during micturition. Due to the statistical self-similarity of the waveforms, the cystometrogram is modeled as discrete-time fractional Brownian motion and the electromyogram as discrete-time fractional Gaussian noise. Fractal dimensions of both of them are calculated and used as indices in the investigation of synergia. Results indicate that, for intact rats, the sphincter muscle is not only active but also recruited in a synchronous fashion with the detrusor. Furthermore, clear-cut measure using the fractal dimensions can be used to diagnose detrusor-sphincter synergia and dyssynergia.

[Alteration of sensitivity of supraoptic nucleus neurons to cytokine in the hypothalamic slices from the rat after lipopolysaccharide injection]

Using the whole cell patch clamp technique, the effects of interleukin 1beta (IL-1beta) and IL-2 on the membrane potential and spontaneous discharges in the supraoptic nucleus (SON) neurons from the rat hypothalamic slices in vitro were examined to determine the changes in sensitivity of supraoptic nucleus neurons to cytokine. The results obtained are as follows. IL-1beta (100 U/ml) hyperpolarized the SON neurons from the control rats (n=15) and the rats 9 d after i.p. lipopolysaccharide (LPS) (n=20), and decreased the rate of their spontaneous discharges. When 100 U/ml IL-2 was perfused, most SON neurons (n=14) from the control rats were hyperpolarized and the spontaneous firing decreased, but the rest (n=3) remained unchanged. When IL-2 (100 U/ml) was applied, 19 neurons out of the 45 SON neurons from the rats 9 days after i.p. LPS were depolarized accompanied with an increase of the discharges, 16 did not show significant changes in both membrane potential and spontaneous discharges, the rest 10 were hyperpolarized and their discharges were suppressed. These results show that the sensitivity of part of SON neurons from the immuned rat to cytokine IL-2 was altered, suggesting that IL-2 may be involved in modulation of the activity of SON neurons and thus play a role in modulation of the immune response.

Mechanical and thermal hyperalgesia and ectopic neuronal discharge after chronic compression of dorsal root ganglia

Chronic compression of the dorsal root ganglion (CCD) was produced in adult rats by implanting a stainless steel rod unilaterally into the intervertebral foramen, one rod at L(4) and another at L(5). Two additional groups of rats received either a sham surgery or an acute injury consisting of a transient compression of the ganglion. Withdrawal of the hindpaw was used as evidence of a nocifensive response to mechanical and thermal stimulation of the plantar surface. In addition, extracellular electrophysiological recordings of spontaneous discharges were obtained from dorsal root fibers of formerly compressed ganglia using an in vitro nerve-DRG-dorsal root preparation. The mean threshold force of punctate indentation and the mean threshold temperature of heating required to elicit a 50% incidence of foot withdrawal ipsilateral to the CCD were significantly lower than preoperative values throughout the 35 days of postoperative testing. The number of foot withdrawals ipsilateral to the CCD during a 20-min contact with a temperature-controlled floor was significantly increased over preoperative values throughout postoperative testing when the floor was 4 degrees C (hyperalgesia) and, to a lesser extent, when it was 30 degrees C (spontaneous pain). Stroking the foot with a cotton wisp never elicited a reflex withdrawal before surgery but did so in most rats tested ipsilateral to the CCD during the first 2 postoperative weeks. In contrast, the CCD produced no changes in responses to mechanical or thermal stimuli on the contralateral foot. The sham operation and acute injury produced no change in behavior other than slight, mechanical hyperalgesia for approximately 1 day, ipsilateral to the acute injury. Ectopic spontaneous discharges generated within the chronically compressed ganglion and, occurring in the absence of blood-borne chemicals and without an intact sympathetic nervous system, were recorded from neurons with intact, conducting, myelinated or unmyelinated peripheral nerve fibers. The incidence of spontaneously active myelinated fibers was 8.61% for CCD rats versus 0.96% for previously nonsurgical rats. We hypothesize that a chronic compression of the dorsal root ganglion after certain injuries or diseases of the spine may produce, in neurons with intact axons, abnormal ectopic discharges that originate from the ganglion and potentially contribute to low back pain, sciatica, hyperalgesia, and tactile allodynia.

[Protein kinase a mediated excitatory adrenergic effect on chronically compressed dorsal root ganglion neurons in rats]

With a model of chronically compressed dorsal root ganglion (CCD), the present study was undertaken to test how the plasticity of sympathetic-sensory coupling is and whether the coupling is mediated by intracellular messenger PKA by analysing extracellularly recorded spontaneous activity of single A-fibers originating from the CCD neurons in vitro. Eighty-five out of 95 neurons from injured DRGs during application of norepinephrine (NE) were adrenosensitive. Among the 85 neurons, 44 exhibited excitation, 21 showing excitation followed by suppression, 6 displaying alternated excitation and suppression, and 14 suppression. In addition, adrenosensitivity was observed in 15 silent injured DRGs. The excitatory effect of NE was blocked by alpha 1 and alpha 2 adrenoceptor antagonists yohimbine (10 mumol/L) or prazosin (5 mumol/L). Rp-cAMPS (50-250 mumol/L, n = 6), a specific inhibitor of PKA, and H-89 (10 mumol/L, n = 6), an inhibitor of PKA catalytic subunit, obviously suppressed the NE-evoked excitation. Furthermore, the excitatory effect of NE was attenuated by SQ 22, 536 (1 mmol/L), an adenylate cyclase inhibitor (n = 6). The above results demonstrate that injury to DRG neuron body triggered the adrenosensitivity, which was mediated by alpha 1, alpha 2 adrenoceptors and PKA.

[Pattern and dynamic changes of integer multiples in spontaneous discharge of injured dorsal root ganglion neurons]

For the purpose of the present investigation, spontaneous discharges of dorsal root ganglion (DRG) neurons of the rats, which had undergone 3-10 days' chronic compression, were studied. It was found that the interspike interval (ISI) of 17 out of 156 fibers had integer multiples temporal rhythm pattern, in which all the ISI were integer multiples of a basic ISI and a return map of their ISI could be constructed as a crystal grid structure. This temporal pattern could be modified by Na+ channel and K+ channel on their membranes. These data indicated the presence of some irregular discharge trains with their intrinsic regularity.

Relationship between calcium-dependent potassium channel and ectopic spontaneous discharges of injured dorsal root ganglion neurons in the rat

The ectopic spontaneous discharges (ESD) of single myelinated dorsal root fiber originated from the injured dorsal root ganglion (DRG) neurons were recorded in vivo. When [Ca(2+)](o) perfusing the injured DRG had been enhanced or caffeine been used, the ESD was inhibited in dose-dependent manner, while using Ni(2+) or EGTA, the ESD facilitated. The increment of [K(+)](o) and the use of TEA could both facilitate the ESD in dose-dependent manner. Apamin, a special antagonist of calcium-dependent potassium channel (K(Ca)), had markedly increased the number of ESD. These results suggest that the generation of ESD has close relation to the activity of K(Ca) channel.

Fractal geometry in urodynamics of lower urinary tract

The physiological signals are usually extremely complicated and difficult to analyze. Recently, investigators have tried the fractal dimension that can characterize roughness and self-similarity of them. It turns out that it is also suitable for obtaining the modalities of lower urinary tract during normal micturition. In this investigation, the external urethral sphincter electromyogram (EUS EMG) and the cystometrogram (CMG) of the Wistar rats under both room temperature and cold water stimulation of the bladder are studied. The modified relative differential box-counting (RDBC) method is used to calculate the fractal dimensions of EMG and CMG time series. According to the experimental results, the modalities of micturition for the Wistar rats can be characterized as normal if both the fractal dimensions of EMG and CMG are of low values during voiding. Furthermore, the technique is validated in identifying the dyssynergia of the bladder and EUS under cold water stimulation.

Terrestrial gamma ray dose rates of Brunei Darussalam

GPS-indexed in-situ and car-borne survey of terrestrial gamma-ray dose rates were carried out in Brunei and adjacent areas using two portable NaI(Tl) counters. The mean and population weighted average dose rates for Brunei are 34 and 33 nGy/h, respectively. The car-borne data and the in-situ data when spectral analysed separately, were found to show fractal behaviour with D of 1.7 and 1.8, respectively. A contour map of the dose rates was also produced.

[Apamin sensitive component of Ca(2+)-activated K+ current of afterhyperpolarization, IAHP, in dorsal root ganglion neurons in rat]

Whole-cell voltage clamp technique was used to record the tail current in freshly isolated dorsal root ganglion (DRG) neurons of rat with an aim to investigate whether these neurons possess an apamin sensitive component of Ca(2+)-activated K+ current, IAHP. The results are as follows: (1) the amplitudes of the tail currents increased from 9.3 +/- 2.8 pA to 64.1 +/- 3.4 pA (P < 0.001) when the depolarizing duration was increased from 1 ms to 180 ms; (2) the amplitudes of the tail current were reduced when repolarizing pulses were applied, with a reversal potential of about -63 mV; (3) the amplitude of the tail current was significantly depressed or even almost completely blocked by extracellularly applied 500 mumol/L Cd2+ or intracellularly applied 11 mmol/L EGTA; (4) the amplitudes of the tail currents were decreased by about (26.32 +/- 3.9)% (P < 0.01) after 200 nmmol/L apamin was extracellularly applied; and (5) the fast component of the tail current was sensitive to 10 mmol/L TEA while the slow component was insensitive. These results suggest that an apamin sensitive component of Ca(2+)-activated K+ current may be present in afterhyperpolarization of DRG neurons.

[Alteration of inositol phosphate metabolism in aortic smooth muscle cells from spontaneously hypertensive rat]

The changes of inositol phosphates in quiescent and GTP gamma S activated vascular smooth muscle cells (VSMC) derived from aorta of spontaneously hypertensive rat (SHR) were examined. The inositol phosphate assay revealed that there was no difference in the inositol-1, 4, 5-triphosphate (InsP3) level between the quiescent VSMCs of SHR and that of normotensive Wistar-Kyoto rats (WKY). G-protein activator GTP gamma S caused a dose- and time-dependent increase in the InsP3 level in VSMCs. Activated G proteins increased significantly the InsP3 level in VSMCs of SHR. In conclusion, the highly sensitive reactivity to GTP gamma S in the generation of InsP3 in VSMCs from SHR may be related to the possible abnomality of the number, substructure or function of some components in G proteins, phosphoinositide turnover.

[G proteins-phosphoinositide pathways in hypertension]

The second messenger inositol-1,4,5-trisphosphate (InsP3) comes from two major pathways, one is initiated by a family of G protein-linked receptors and the other by receptors linked by tyrosine kinases. These separate receptors activate phospholipase C to hydrolyse phosphatidylinositol-4,5-bisphosphate to give both diacylglycerol and InsP3. The latter then mobilizes stored calcium and promotes an influx of external calcium. The alpha subunit of a newly discovered G protein (Gq) has recently been shown to stimulate the activity of PLC-beta 1. The alpha subunits of the Gq class of G proteins includes G alpha q, G alpha 11, G alpha 14, G alpha 15 and G alpha 16. The important pathologic changes in hypertension are arteriolar spasm and wall thickening. Many vasoactive substances can induce contractile response and proliferation of vascular smooth muscle cells and increase InsP3 level. However, the hypertension does not cause any persistent change in Gq.

Effect of modified calm conditions on nuclear dispersion estimates

When the definition of calm in atmospheric diffusion analyses is changed from 0.5 m s-1 to 0.1 m s-1, actual and more accurate low wind speeds and wind directions can be used to calculate the average air concentrations due to continuous releases of radionuclides at 10-m stack height more realistically and accurately. However, this modified calm condition has little affect on the calculated adult thyroid exposure for a postulated accident.

Lack of inotropic effect of cyclosporin A in isolated guinea pig left atria

OBJECTIVE

Cyclosporin A is being widely used to prevent graft rejection in organ transplantation and to treat autoimmune diseases. Since various toxic side effects have been observed, the aim of this study was to look for even a subtle deleterious effect of cyclosporin A on cardiac inotropy in electrically stimulated guinea pig left atria.

METHODS

The left atrial muscles of guinea pigs, in Tyrode's solution containing 2.7 or 5.4 mM potassium, were electrically stimulated by one of two methods: (1) continuously at 3 Hz, during which cyclosporin A was applied cumulatively (from 10(-9) to 10(-5) M); or (2) stimulated intermittently at 2.5 Hz in 5 mM cyclosporin A, with rest periods of 4 s duration interposed every 4 min. The effects of cyclosporin A on contractile force were observed for 150 min in the first stimulation method, and the effects on the steady state contractile force and amplitude of post-rest contraction were observed for 240 min in the second method.

RESULTS

The steady state contractile force of the atria declined within the 4 h period at 2.7 mM potassium in Tyrode's solution both in the cyclosporin A group (n = 10) and in the control group (n = 5) to 68(SD 11)% and to 63(4)%, respectively. After 4 h the amplitudes of the post-rest contraction were 101(16)% and 101(4)% in cyclosporin A and control groups, respectively. At 5.4 mM potassium, the following values were obtained (cyclosporin A v control): steady state force 70(8)% (n = 11) v 69(8)% (n = 5); post-rest force 105(9)% v 102(7)%.

CONCLUSIONS

Cyclosporin A does not influence the steady state contractile force or the amplitude of the post-rest contraction, suggesting the absence of inotropic effects on isolated guinea pig left atria.

[Humoral factors in the modulation of sustained discharges of polymodal nociceptors]

By using a model of sustained discharges of polymodal nociceptors (PMN) due to injection of a compound algogenic substance into the skin in anesthetized rats, it was found that stimulation of the sciatic nerve inhibited or facilitated at first and then inhibited the PMN sustained discharges markedly. In a crossperfused preparation, stimulation of the sciatic nerve of donor rat caused the similar effects on sustained discharges of PMN of the recipient rat. Injection of the animal serum after stimulation of the sciatic nerve affected PMN activity obviously. The inhibitory course of most units could not be reversed by naloxone. In the animal tolerance to morphine, the effects of stimulation of the sciatic nerve could still be obtained. Preadministration of reserpine almost completely abolished the facilitatory effect. The results indicate that sustained activity of PMN could be modulated by some humoral factors due to somatic afferents. The inhibitory substances in the humoral factor seem to be both opioid and nonopioid in nature. The facilitatory substance seem to be a catecholamine.

Development of an automated human sperm quality system

A computer-automated system, including hardware and software components, is developed for objective assessment of human sperm density and other characteristics, including morphological abnormalities and motility. The hardware component essentially consists of an IBM AT, a relatively low-cost image processing board and other inexpensive commercially available instruments. On the other hand, the software component is developed through the incorporation of image analysis, pattern recognition and modelling techniques with the knowledge of human reproduction from the available literature. The whole system is expected to produce a practical and cost-effective means for the routine assessment of human semen quality.

Platelet-fibrin interaction in the suspension and under flow conditions

Interactions between platelets and fibrin are important in hemostasis but often confused with platelet-fibrinogen interactions. A stirred mixture of solubilized fibrin and washed platelets at neutral pH range showed drastic reduction in turbidity and concomitant platelet adhesion onto newly formed fibrin strands. This platelet-fibrin interaction did not require platelet activation nor did it cause platelet aggregation. A device consisting of a parallel-plate flow chamber mounted on a fluorescence microscope has been constructed to allow direct visualization and recording of platelet-fibrin interaction under flow conditions. Platelets in whole blood adhered to the fibrin-coated portion but not to the uncoated portion of the flow chamber. Slow motion playback of video tapes indicated that the adhesion phenomenon was a dynamic process that involved attaching, detaching, relocation and transient contact. The fibrin coating influenced platelet adhesion both by increasing the number of cells making short-term attachments to the surface and by increasing the duration of cells attached to the surface. These observations provided basic characteristics of platelet-fibrin interaction.

[The facilitatory effect of sympathetic efferents on sustained discharges of polymodal nociceptors]

Injection of a compound algogenic substance into receptive field of the skin induced sustained discharges of polymodal nociceptors in rats. The sustained discharges were obviously increased by stimulation of the sympathetic nerve innervating the receptive field. Initial facilitation was followed by the inhibition of discharges in partial units. The sympathetic effect can be activated repeatedly and lasted for a prolonged time. Injection of norepinephrine (5 micrograms/0.2 ml) into the local artery could cause the similar effect. Results indicate that the sympathetic efferents facilitates the sustained discharges of polymodal nociceptors. The possibility of producing causalgia and contrary results of experiments were discussed.

Direct platelet-fibrin interaction that does not require platelet activation

Interactions between platelets and fibrin are important in hemostasis but often confused with platelet-fibrinogen interactions. Fibrin solubilized in NaBr-acetic acid formed polymers in neutral pH buffers. A stirred mixture of solubilized fibrin and washed human platelets at neutral pH range showed drastic reduction in turbidity and concomitant platelet adhesion onto newly formed fibrin strands. Optimally, more than 99% of platelets could be associated with fibrin, whereas only 3% of erythrocytes were trapped in the fibrin network under similar conditions. This platelet-fibrin interaction was fibrin concentration dependent and polymerization stage dependent. It preceded any detectable platelet release of serotonin. Gly-Pro-Arg-Pro (250 times in excess) retarded the kinetics of fibrin polymerization as well as that of platelet-fibrin interaction. However, factors affecting platelet activation showed little effect on platelet-fibrin interaction. Our results support the existence of a platelet-fibrin interaction that does not require platelet activation.

Intra-hisian block associated with unusual etiologies

One hundred and sixty-nine patients underwent electrophysiologic study for atrioventricular block. Forty-five (27%) had intra-Hisian block. Four of these 45 patients had unusual etiologies: rheumatoid arthritis, cysticercosis cellulosae, Behcet's disease, and Takayasu aorto-arteritis. Their clinical and electrophysiologic features are described in detail.

Factors affecting the production of amphotericin A

Factors affecting amphotericin A synthesis of Streptomyces nodosus, NDMC-034 were studied. Iron, magnesium and manganese were found to stimulate amphotericin A synthesis at concentrations ranging from 10-100 microM. The optimum inoculum size, and the pH of production medium before sterilization for producing amphotericin A, were found to be near 10% (v/v) and pH 7.8, respectively. Carrying out fermentation in a complex medium using pharmamedia as nitrogen source resulted in an amphotericin A yield of up to 3.4 g/liter. A novel isolation and purification process for amphotericin A from the fermentation broth was developed, using an extracting isopropyl alcohol and methanolic solution containing 2% CaCl2. Amphotericin A exhibits a much lower acute toxicity in mice than amphotericin B.