[Clinical characteristics of COVID-19 Omicron variant infection in children with allergic diseases]

Objective: To analyze the clinical characteristics of infection of COVID-19 Omicron variants in children with allergic diseases. Methods: This was a cross-sectional retrospective study. A total of 657 pediatric patients with allergic diseases aged between 0-17 years confirmed with COVID-19 infection were enrolled from the Children's Hospital affiliated to Capital Institute of Pediatrics from January to March 2023. The median age was 6.6(4.7,9.9) years, with 443 males (67.4%) and 214 females (32.6%). Demographic data, vaccination status, clinical manifestations, therapeutic drugs, and other data were collected. The patients were then divided into different groups according to the age, type of allergic diseases and vaccination status, and their clinical characteristics were compared. Results: A total of 657 children with allergic diseases were included in this study, among them 568 with asthma. Fever is the most common symptoms after COVID-19 infection (627/657, 95.4%), and 509 children (77.5%) with high fever. Cough was observed in 446 (67.9%) and fatigue in 167 (25.4%) cases.10 cases (1.5%) were diagnosed as pneumonia. The proportion of pharyngalgia(22%,84/382, χ2=19.847, P<0.01), fatigue (31.7%, 121/382,χ2=23.831, P<0.01), headache(34.6%, 132/382,χ2=57.598, P<0.01), muscle joint pain(16.0%, 61/382,χ2=22.289, P<0.01) and vomiting(11.0%, 42/382,χ2=12.756, P<0.01) were highest in the>6 years group. Children younger than 3 years had the lowest proportion of runny nose(8.8%, 5/57,χ2=8.411, P<0.01), cough(45.6%, 26/57,χ2=6.287, P<0.05) and expectoration(7.0%, 4/57,χ2=5.950, P<0.05). 62.8%(137/218) of the patients in 3-6 year group had the highest rate of cough(χ2=6.287, P<0.05), with a higher proportion of wheezing (10.1%, 22/218). Cough and/or wheezing symptoms were most quickly relieved in the 6 year old group, who had a highest proportion of 68.8%(260/382) in duration of respiratory symptoms within 1 week compared with 52.2% (114/218)of 3-6 years group and 41.2% (22/57)of<3 year group, respectively(χ2=23.166, P<0.01). The asthma group had a significant higher proportion of cough(59.7% vs 41.6%, χ2=10.310, P<0.01), wheezing (8.5% vs 0.0%, χ2=8.114, P<0.01) and expectoration (19.2% vs 7.9%, χ2=10.310, P<0.01) than that of non-asthma group. Besides, patients with cough and/or wheezing in the asthma group had more impact on exercise and sleep (16.1% vs 0, χ2=5.436, P<0.05) and a longer duration over 4 weeks (25.1% vs 3.7%, χ2=6.244, P<0.05). Conclusions: The most common symptoms in children with allergy infected with COVID-19 Omicron variant were fever and cough. Children under 3 years of age had relatively fewer respiratory symptoms while those with asthma or aged 3-6 years were more likely to have cough and wheezing and longer duration of symptoms. The data suggested that the prevention and management of COVID-19 should be strengthened in children with allergy.

[Clinical characteristics of children with IgE-mediated cow's milk protein allergy]

Objective: To analyze the clinical characteristics of children with IgE-mediated cow's milk protein allergy (CMPA) and provide a basis for disease management and prevention. Methods: A cross-sectional study was conducted to analyze 142 children aged 0-12 years who were diagnosed with IgE-mediated CMPA in Capital Institute of Pediatrics Affiliated Children's Hospital from 2020 to 2022. There were 79 males (55.6%) and 63 females (44.4%), with an average age of 14 (8, 27) months. 61 cases (43.0%) were in the <1-year-old group, 54 cases (38.0%) in the 1-3-year-old group, and 27 cases (19.0%) in the >3-year-old group. Data on demographic data, clinical manifestations, mean wheel diameter of skin prick test and serum specific IgE level were collected. The serum cow's milk protein sIgE and component sIgE were measured by ImmunoCAP fully automated system of fluorescence enzyme-linked immunosorbent assay, and statistically analyzed using chi-square test, nonparametric tests, correlation. Results: Cutaneous symptoms were the first and most frequent in 142 children (97.9%, 139/142 cases), followed by digestive (29.6%, 42/142 cases) and respiratory symptoms (27.5%, 39/142 cases).The proportion of children with respiratory symptoms after consuming cow's milk was significantly higher in the>3 years age group than those in the infant and toddler groups(66.7% vs 19.7%,χ2=18.396,P<0.01;66.7% vs 16.7%,χ2=20.250,P<0.01), and the symptoms involving ≥3 systems were also significantly higher than those in the other two groups(37.0% vs 13.1%,χ2=6.597,P<0.05;37.0% vs 7.4%,χ2=12.120,P<0.01). The average cow's milk SPT diameter and serum sIgE levels in the>3 years age group were significantly higher than those in the infant and toddler groups (Z=-4.682, P<0.01; Z=-3.498, P<0.01); (Z=-4.463, P<0.01; Z=-6.463, P<0.01). The most common cow's milk component protein were β-lactoglobulin(65.1%,56/86 cases) and casein (57.0%, 49/86 cases). Multiple-sensitization rate of the patients were 54.9%. Egg white (43.7%, 62/142 cases) was the most common co-sensitization food allergen while mold (12.7%, 18/142 cases) and weed pollen (12.7%, 18/142 cases) were the main co-sensitization aeroallergens. The proportion of multiple-sensitization to aeroallergens in the children group was the highest (51.9%, 14/27 cases), followed by the toddler group (29.6%, 16/54 cases), and the infant group was the least (3.3%, 2/61 cases). There was a significant difference among these three groups (χ2=7.476, P<0.05). Conclusion: Skin and mucosal symptoms are the most common in CMPA patients. The proportion of respiratory symptoms and multisystem involvement increased with age as well as the wheal diameter in skin test and serum sIgE level elevated. CMPA patients older than 3 years had the highest proportion of aeroallergen sensitization and airway allergic diseases.

[Research advances in chest tightness variant asthma]

Chest tightness variant asthma (CTVA) is a special type of asthma with chest tightness as the only or main symptom. Due to the lack of typical asthma symptoms such as coughing, wheezing, shortness of breath, and positive signs in chest, it is easy to be missed or misdiagnosed in clinical practice. The onset of chest tightness variant asthma is insidious, and there is few research and attention both domestic and international, so there is no unified diagnosis and treatment standard especially in childhood asthma. This article expounds the related research advances in chest tightness variant asthma, in order to increase clinical attention and provide reference and basis for the prevention of the disease as well as the formulation of diagnosis and treatment strategies.

Classification of colorectal cancer into clinically relevant subtypes based on genes and mesenchymal cells

BACKGROUND

Most studies on subtype identification of colorectal cancer (CRC) were based on expressions of either genes or immune cells. However, few studies have hitherto used the combination of genes with immune and stroma cells for subtype identification.

METHODS

Dataset GSE17536 was obtained from the Gene Expression Omnibus (GEO) database. The xCell algorithm was used to estimate the composition and density of 64 cell types, including immune and stroma cell types. Clustering analysis was then conducted on the top 3000 most variable genes from a total of 20,174 genes for CRC subtype identification. We employed the ensemble method of Similarity network fusion and 112 Consensus Clustering (SNF-CC) for cancer subtype identification. Reactome pathway analysis was conducted to identify the impact of the representative genes on prognosis. The results were validated in independent gene expression data from dataset GSE17537.

RESULTS

In this study, we identified 3 clinically relevant subtypes and their representative genes, immune and stroma cells. Moreover, we confirmed the correlation of these subtypes with their clinical characteristics. The representative genes of the subtype with poor prognosis correlated with extracellular matrix structural constituent, while the subtype with good prognosis correlated with Toll-like receptor signaling pathway or chemokine signaling pathway. However, different subtypes were associated with distinct cell subtypes; the subtype with poor prognosis had a high abundance of fibroblasts and endothelial cells; the subtype with median prognosis had a higher abundance of immune cells, such as CD4 + T-cell, Th2 cells and aDC; the subtype with good prognosis had a higher abundance of NKT.

CONCLUSION

This study highlights the utility of immune and innate cells, especially during gene analysis, to provide the theoretical basis for personalized treatment in colorectal cancer patients.

[Characteristics and changes of sensitization patterns of major allergens in children from 2010 to 2020 in a hospital of pediatric in Beijing]

Objective: To analyze the sensitization characteristics and change of major allergens in children from 2010 to 2020 in Beijing, so as to provide basis for diagnosis, treatment and prevention of allergic diseases in children. Methods: A retrospective study was conducted to analyze the children who were suspected of allergic diseases and tested for serum immunoglobulin E (total IgE and specific IgE) in the children's Hospital Affiliated to the Capital Institute of Pediatrics from January 2010 to December 2020. A total of 45 746 children aged 0-17 years in Beijing were enrolled with a median (interquartile range) of 3.8 (2.5, 5.3) years. There were 28 918 boys (63.2%) and 16 828 girls (36.8%) and 14 984 cases (32.8%) in the infant group (<3 years old), 22 049 cases (48.2%) in the preschool group (3-6 years old), and 8 713 cases (19.0%) in the school-age group (6 years old and above). Immunocap allergen detection system (fluorescence enzyme-linked immunosorbent assay) was used to detect and the characteristics and change trend of allergens during 11 years were statistically analyzed by Chi square test. Results: The top three positive rates of single food allergens sIgE were egg white 42.6% (2 788/6 577 tests), milk 38.4% (2 606/6 782 tests) and wheat 31.8% (1 417/4 449 tests), and the sequence of single inhaled allergens were Ragweed 42.6% (440/1 034 tests), Artemisia 38.4% (1 045/3 191 tests) and Alternaria alternata 31.3% (3 358/10 725 tests). The positive detection rates of egg white 47.0%(1 904/4 048 tests), milk 41.9%(1 769/4 226 tests) and wheat 33.9%(973/2 870 tests) in the infant group were the highest, and there have statistically significant(χ²=91.495, 73.907, 16.966, P<0.05). The positive rates of fx1 (22.5%, 121/537 tests), peanut (24.9%, 111/446 tests), soybean (20.0%, 74/370 tests) and shrimp (7.48%, 44/588 tests) were the highest in the school-age group(χ²=14.436, 10.751, 11.569, 13.703, P<0.05). The most common inhaled allergens were Alternaria alternata (14.8%, 422/2 859 tests) in the infant group, Ambrosia (34.5%, 143/415 tests) and Alternaria alternata (33.5%, 1 762/5 254 tests) in the preschool group, while in the school-age group were Ambrosia (56.4%, 282/500 tests) and Artemisia (48.2%, 573/1 189 tests). The positive rates of egg white, milk, wheat, sesame seed and peanut varied from 2010 to 2020, showing a trend of falling first and then rising(χ²=10.293,χ²=12.066,χ²=7.402,χ²=32.458,χ²=31.747,P<0.05).The positive detection rates of soybean showed a significant downward trend (21.4%, 173/809 tests in 2010, 15.4%, 70/455 tests in 2020, χ²=6.751,P=0.009), while that of shrimp and crab were at a stable low level(χ²=0.263, 1.346;P>0.05). From 2010 to 2020, mold (26.7%, 1 066/3 998 tests in 2010, 40.2% 1 705/4 243 tests in 2020), grass pollen (19.8%, 259/1 308 tests in 2010, 39.3%, 1 472/3 746 tests in 2020), tree pollen(17%, 180/1 058 tests in 2010, 29.8%, 916/3 075 tests in 2020) and animal dander (18.5%, 111/601 tests in 2010, 26.6%, 672/2 522 tests in 2020) were all showed significant upward trend (χ²=168.600, 163.601, 65.931 and 17.271 respectively, P<0.001) but dust mites (30.7%, 1 270/4 132 tests in 2010, 26.7%, 1 126/4 221 tests in 2020) showed a significant downward trend(χ²=16.822,P<0.001).In 2010, the most common inhaled allergen was dust mite 30.7% (1 270/4 132 tests), followed by mold 26.7% (1 066/3 998 tests), while they were mold 40.2% (1 705/1 243 tests), and grass pollen 39.3% (1 472/3 746 texts) respectively in 2020. Conclusion: In the past 11 years, the main food allergens in children were still egg white and milk, wheat, but the mold and pollen gradually replaced dust mite as the most common inhaled allergen.

[Clinical characteristics of IgE-mediated cow's milk protein allergy in children]

Objective: To analyze the clinical features of IgE-mediated cow's milk protein allergy (CMPA) in children aged 0-5 years. Methods: This cross-sectional study collected the data on children diagnosed with CMPA in the Department of Allergy at the Children's Hospital of the Capital Institute of Pediatrics from October 2019 to November 2020 and improved peripheral blood routine,total IgE defection, milk specific IgE (sIgE) defection,SPT and milk component defection,diagnosis of severe anaphylaxis based on clinical manifestations. Rank-sum test and chi-square test are used for statistical analysis of clinical characteristics between groups. Results: A total of 106 children (67 boys and 39 girls) were enrolled with the age of 15 (8, 34) months, including 42 cases (≤ 1 year of age), 39 cases (>1-<3 years of age) and 25 cases(≥3 years of age), the onset age of 6 (5, 8) months. Among them, 95 cases (89.6%) were reacted after consuming milk or its products, 42 cases (39.6%) had reaction due to skin contact and 11 cases (10.4%) reacted after exclusive breastfeeding. The onset time of milk product consumption was 45 (1, 120) min, skin contact pathway was 10 (5, 30) min and symptoms in breastfeeding pathway was 121 (61, 180) min. There was statistical difference among the time of symptoms (χ²=77.01, P<0.001).The cutaneous reaction was most common (100 cases, 94.3%), followed by digestive (20 cases, 18.9%) and respiratory (16 cases, 15.1%), and the nervous symptoms (1 case, 0.9%) were uncommon and 24 cases (22.6%) had at least one episode of anaphylaxis. There were 87 cases (82.1%) also diagnosed with other food allergies, 94 cases (88.7%) with previous eczema, 57 cases (53.8%) with history of rhinitis, and 23 cases (21.7%) with history of wheezing. The total IgE level was 191.01 (64.71, 506.80) kU/L, and the cow's milk sIgE level was 3.03 (1.11, 15.24) kU/L. The maximum diameter of the wheal in SPT was 8.2 (4.0, 12.0) mm. Component resolved diagnosis showed that 77 cases (81.9%) were sensitized to at least one out of 4 main components, including casein, α lactalbumin, β lactoglobulin and bovine serum albumin.The possibility of anaphylaxis in children with milk sIgE grade Ⅳ-Ⅵ was higher than that in children with grade 0-Ⅲ (57.7% (15/26) vs. 12.5% (10/80), OR=9.545, 95%CI 3.435-26.523). Children with milk SPT ≥+++ had a higher probability of anaphylaxis than those with milk SPT ≤++ (34.4% (11/32) vs. 11.5% (3/26), OR=4.016, 95%CI 0.983-16.400). Anaphylaxis were more common in α lactalbumin positive children than in negative children (34.3% (13/38) vs. 14.2% (8/56), χ²=1.23，P=0.042). Conclusions: CMPA in children has early onset and diversified clinical manifestations, which are mainly cutaneous symptoms. Most children are sensitized to at least one allergen component. Serum sIgE level, SPT reaction and allergen components play important roles in the diagnosis and evaluation of CMPA, and higher milk sIgE level may predict a higher risk of anaphylaxis.

The Immune Landscape of Hepatitis B Virus-Related Acute Liver Failure by Integration Analysis

Hepatitis B virus-related acute liver failure (HBV-ALF) is a common type of liver failure, associated with high short-term mortality and morbidity rates. However, the immune landscape of HBV-ALF and its correlation with cell death are currently unknown. Based on 3 Gene Expression Omnibus data sets, infiltrated immune cells were quantified by single-sample gene set enrichment analysis method. The expression levels of immune genes and the abundance of immune cells in liver failure were compared with those in normal liver. The enrichment scores of cell death gene sets from Kyoto Encyclopedia of Genes and Genomes (KEGG) were calculated by gene set variation analysis method, and a protein-protein interaction (PPI) network was constructed using Cytoscape. Besides 21 differentially expressed immune genes, we identified 11 types of differentially infiltrated immune cells in HBV-ALF compared with normal liver. Enriched pathways of these immune genes mainly consisted of chemokine receptors, chemokine binding, interleukin-10 signaling, and TNFs bind their physiological receptors by Reactome pathway analysis. In addition, the enrichment scores of apoptosis and necroptosis pathway instead of autophagy and ferroptosis were increased in liver failure compared with normal liver. PPI network and gene cluster analysis of immune genes and apoptosis and necroptosis genes suggested that hub genes were mainly related to immune response and apoptosis. In summary, our study offers a conceptual framework to understand the immune landscape of HBV-ALF, which might help to improve prognosis.

The association of plasma acyl ghrelin level with alcohol craving in early abstinent alcohol dependent patients

Background

Craving plays an important role in maintenance of alcohol dependence. Earlier studies have analyzed the role of ghrelin in craving and their results have been heterogenous. Acyl ghrelin is its more active form as it crosses the blood brain barrier. Hence we aimed to examine the relationship between plasma acyl ghrelin and craving in Indian patients having alcohol dependence syndrome.

Methods

The present study was a hospital-based prospective study. A total of 60 drug-naive patients of alcohol dependence and 30 healthy controls were included. After taking informed consent fasting blood samples were collected from them on day 1 and tested for plasma acyl ghrelin level. Fasting blood samples were repeated in all cases on day 14. During this time, we also assessed the patients' cravings by obsessive compulsive drinking scale, and alcohol craving questionnaire; and withdrawal by clinical institute withdrawal assessment for alcohol scale. These scales were repeated on day 14. Data analysis was done by SPSS version 25.0.

Results

Plasma concentrations of acyl ghrelin increased significantly during early abstinence in patients from day 1 to day 14 (P < 0.0001). Pearson correlation test revealed a trend of positive correlation between plasma concentration of acyl ghrelin on day 14 and severity of craving on day 1.

Conclusion

Our results suggest the plasma concentration of acyl ghrelin may be a predictor of severity of alcohol craving during early abstinence. Anti-craving drugs acting on acyl ghrelin level in brain may open an innovative avenue for optimum treatment of alcohol dependence.

Activated Hepatic Stellate Cells Induce Infiltration and Formation of CD163+ Macrophages via CCL2/CCR2 Pathway

Background: Activated hepatic stellate cells (aHSCs) regulate the function of immune cells during liver fibrosis. As major innate cells in the liver, macrophages have inducible plasticity. Nevertheless, the mechanisms through which aHSCs regulate macrophages' phenotype and function during liver fibrosis and cirrhosis remain unclear. In this study, we examined the immunoregulatory function of aHSCs during liver fibrosis and explored their role in regulating macrophage phenotype and function. Methods: A total of 96 patients with different stages of chronic hepatitis B-related liver fibrosis were recruited in the study. Metavir score system was used to evaluate the degree of fibrosis. The expression of hepatic CCL2 and M2 phenotype macrophage marker CD163 were detected by immunohistochemistry, and the relationship among hepatic CD163, CCL2, and fibrosis scores were also explored. In the in vitro model, the aHSCs isolated from human liver tissues and THP-1-derived M0-type macrophages (M0MΦ) were co-cultured to observe whether and how aHSCs regulate the phenotype and function of macrophages. To explore whether CCL2/CCR2 axis has a crucial role in macrophage phenotypic changes during liver fibrosis, we treated the M0MΦ with recombinant human CCL2 or its specific receptor antagonist INCB-3284. Furthermore, we used LX2 and TGF-β-activated LX2 to mimic the different activation statuses of aHSCs to further confirm our results. Results: In patients, the infiltration of M2 macrophages increased during the progression of liver fibrosis. Intriguingly, as a key molecule for aHSC chemotactic macrophage aggregation, CCL2 markedly up-regulated the expression of CD163 and CD206 on the macrophages, which was further confirmed by adding the CCR2 antagonist (INCB 3284) into the cell culture system. In addition, the TGF-β stimulated LX2 further confirmed that aHSCs up-regulate the expression of CD163 and CD206 on macrophages. LX2 stimulated with TGF-β could produce more CCL2 and up-regulate other M2 phenotype macrophage-specific markers, including IL-10, ARG-1, and CCR2 besides CD163 and CD206 at the gene level, indicating that the different activation status of aHSCs might affect the final phenotype and function of macrophages. Conclusions: The expression of the M2 macrophage marker increases during liver fibrosis progression and is associated with fibrosis severity. AHSCs can recruit macrophages through the CCL2/CCR2 pathway and induce M2 phenotypic transformation.

Bayesian network to predict hepatitis B surface antigen seroclearance in chronic hepatitis B patients

There is a need for an interpretable, accurate and interactions-considered model for predicting hepatitis B surface antigen (HBsAg) seroclearance. We aimed to construct a Bayesian network (BN) model using available medical records to predict HBsAg seroclearance in chronic hepatitis B (CHB) patients, and to evaluate the model's performance. This was a case-control study. A total of 1966 consecutive CHB patients (mean age 39.04 ± 11.23 years) between January 2006 and June 2015 were included. The demographic and clinical characteristics, laboratory data and imaging parameters were obtained and used to build a BN model to estimate the probability of HBsAg seroclearance. Baseline serum HBsAg and hepatitis Be antigen (HBeAg) levels, virological response and HBeAg seroclearance were the most significant predictors of HBsAg seroclearance. The post-test probability table showed that patients with baseline HBsAg concentrations ≤2000 IU/mL, negative baseline HBeAg, an initial virological response and without HBeAg seroclearance (i.e. no recurrence of HBeAg positivity during follow-up) were most likely to have HBsAg seroclearance. The constructed BN model had an area under the receiver operating characteristic curves of 0.896 (95% confidence interval [CI]: 0.892, 0.899), a sensitivity of 0.840 (95% CI: 0.833, 0.846), a specificity of 0.880 (95% CI: 0.876, 0.884) and an accuracy of 0.878 (95% CI: 0.874, 0.882) for predicting HBsAg seroclearance. The established BN model accurately estimated the probability of HBsAg seroclearance and is a promising tool to assist clinical decision-making.

[A follow-up study of six years' outcome of children with asthma in urban area of Beijing]

Objective: To understand the outcome of asthma in children from urban area of Beijing and the factors associated with the outcome. Methods: A total of 497 children with asthma diagnosed in the epidemiological survey of childhood asthma in urban area of Beijing in 2010 were selected in this study. Telephone follow-up was conducted in 2016 to obtain information about asthma attack, emergency visit, hospitalization, medication and disease control, and data of comorbidities of allergic diseases from 1 year earlier. Enumeration data were compared using chi-square test, measurement data were compared by rank sum test. The multi-factor logistic regression analysis was employed for the relationship between the related factors and asthma, Kaplan-Meier survival analysis and COX regression was employed to understand the relationship between the related factors and the course of the disease. Results: Questionnaires were conducted in 366 children, of whom 66.7% (244/366) were male, and 33.3% (122/366) were female.Compared with 2010, the rate of asthma attack and emergency room visits in children in last 12 months were significantly lower (19.1%(70/366) vs. 57.1%(284/497), and 3.0% (11/366) vs.19.7% (98/497), χ(2)=125.910 and 53.352, both P<0.01). There was no significant change in the proportion of allergic rhinitis and atopic dermatitis in last 12 months compared with that 6 years ago (both P>0.05). The number of children with clinical remission (2 years and above) was 75.4% (276/366). The number of children without remission within 2 years was 24.6% (90/366). The majority of children without remission were less than 12 years old boys (52.4% (33/63) vs. 30.9% (56/181) , χ(2)=9.273, P<0.01) . The proportion of children without remission associated with allergic rhinitis (67.8%(61/90)), atopic dermatitis (30.0%(27/90)), first-degree relatives with asthma (68.9%(62/90)) was higher than that of children with remission (51.8%(143/276), 17.0%(47/276), and 54.7%(151/276), respectively, χ(2)=7.013, 7.079, 5.608, respectively, all P<0.05). The proportion of children without remission who used control drugs was (33.3%(30/90)), which was higher than that in children with remission (7.2%(20/276), χ(2)=39.158, P<0.01). Multiple logistic regression showed that boy (OR=2.402 (1.611-3.580), P<0.05), later onset (OR=4.339 (>3-6 years old vs. 0-3 years old), OR=2.630(>6 years old vs. 0-3 years old), χ(2)=18.512, 31.371, 6.510, all P<0.05) were independent risk factors for asthma remission. COX regression analysis showed that the use of control drugs (HR=0.705 (0.515-0.964), χ(2)=4.795, P<0.05) was the relevant factor in the course of the disease. Conclusions: With the increase of age, the incidence of asthma in children in Beijing city in recent 12 months reduced. Male and late onsets were independent risk factors for asthma remission. The use of control drugs was the relevant factor in the course of the disease.

Expression and function of the Scn5a-encoded voltage-gated sodium channel NaV 1.5 in the rat jejunum

BACKGROUND

The SCN5A-encoded voltage-gated sodium channel NaV 1.5 is expressed in human jejunum and colon. Mutations in NaV 1.5 are associated with gastrointestinal motility disorders. The rat gastrointestinal tract expresses voltage-gated sodium channels, but their molecular identity and role in rat gastrointestinal electrophysiology are unknown.

METHODS

The presence and distribution of Scn5a-encoded NaV 1.5 was examined by PCR, Western blotting and immunohistochemistry in rat jejunum. Freshly dissociated smooth muscle cells were examined by whole cell electrophysiology. Zinc finger nuclease was used to target Scn5a in rats. Lentiviral-mediated transduction with shRNA was used to target Scn5a in rat jejunum smooth muscle organotypic cultures. Organotypic cultures were examined by sharp electrode electrophysiology and RT-PCR.

KEY RESULTS

We found NaV 1.5 in rat jejunum and colon smooth muscle by Western blot. Immunohistochemistry using two other antibodies of different portions of NaV 1.5 revealed the presence of the ion channel in rat jejunum. Whole cell voltage-clamp in dissociated smooth muscle cells from rat jejunum showed fast activating and inactivating voltage-dependent inward current that was eliminated by Na(+) replacement by NMDG(+) . Constitutive rat Scn5a knockout resulted in death in utero. NaV 1.5 shRNA delivered by lentivirus into rat jejunum smooth muscle organotypic culture resulted in 57% loss of Scn5a mRNA and several significant changes in slow waves, namely 40% decrease in peak amplitude, 30% decrease in half-width, and 7 mV hyperpolarization of the membrane potential at peak amplitude.

CONCLUSIONS & INFERENCES

Scn5a-encoded NaV 1.5 is expressed in rat gastrointestinal smooth muscle and it contributes to smooth muscle electrophysiology.

Memantine improves spatial learning and memory impairments by regulating NGF signaling in APP/PS1 transgenic mice

Memantine (MEM) is used for improving the cognitive impairments of the patients suffering from Alzheimer's disease (AD) by multiple neuroprotective mechanisms. However, it is still not clear whether nerve growth factor (NGF) signaling is involved in the mechanisms of MEM. The present study investigated the neuroprotective effects of MEM treatment on the cognitive performance and amyloidosis in APP/PS1 transgenic mice, and disclosed the NGF-related mechanism of MEM. We found that MEM treatment improved the cognitive performance by decreasing the escape latency and path length in the navigation test, by shortening the duration in target quadrant and reducing the frequency to pass through the target in probe trial, and by prolonging the latency and decreasing the frequencies of entering the dark compartment in passive avoidance test. The over-expressions of Aβ(1-42) and amyloid precursor protein (APP) were also decreased in the brains of APP/PS1 mice. Interestingly, MEM treatment improved the decreased NGF levels in APP/PS1 mice. Furthermore, NGF/TrkA signaling was activated by increasing the phosphorylation levels of tyrosine kinase (TrkA), proto-oncogene serine/threonine-protein kinase, Raf1 (c-Raf), extracellular regulated protein kinases (ERK)1/2 and cAMP-response element binding protein (CREB) after MEM treatment. Simultaneously, MEM also inhibited NGF/p75(NTR) signaling via decreasing the cleavage substrate of p75(NTR), increasing the JNK2 phosphorylation and decreasing the levels of p53 and cleaved-caspase 3. Therefore, the dual-regulation on NGF signaling was attributed to the improvements of cognitive deficits and Aβ depositions in APP/PS1 mice. In conclusion, MEM treatment activated the NGF/TrkA signaling, and inhibited the p75(NTR) signaling in APP/PS1 mice to ameliorate the behavioral deficits and amyloidosis, indicating that NGF signaling was a new potential target of MEM treatment for AD therapy.

Effect of endogenous hydrogen sulfide on the transwall gradient of the mouse colon circular smooth muscle

A transwall gradient in resting membrane potential (RMP) exists across the circular muscle layer in the mouse colon. This gradient is dependent on endogenous generation of CO. H2S is also generated in muscle layers of the mouse colon. The effect of endogenously generated H2S on the transwall gradient is not known. The aim was to investigate the role of endogenous H2S. Our results showed that the CSE inhibitor dl-propargylglycine (PAG, 500 μm) had no effect on the transwall gradient. However, in preparations pretreated with the nitric oxide synthase inhibitor N-nitro-l-arginine (l-NNA, 200 μm) and in nNOS-knockout (KO) mouse preparations, PAG shifted the transwall gradient in the depolarizing direction. In CSE-KO-nNOS-KO mice, the gradient was shifted in the depolarizing direction. Endogenous generation of NO was significantly higher in muscle preparations of CSE-KO mice compared to wild-type (WT) mice. The amplitude of NO-mediated slow inhibitory junction potentials (S-IJPs) evoked by electric field stimulation was significantly higher in CSE-KO mouse preparations compared to the amplitude of S-IJPs in wild-type mouse preparations. CSE was present in all submucosal ganglion neurons and in almost all myenteric ganglion neurons. Eleven per cent of CSE positive neurons in the submucosal plexus and 50% of CSE positive neurons in the myenteric plexus also contained nNOS. Our results suggest that endogenously generated H2S acts as a stealth hyperpolarizing factor on smooth muscle cells to maintain the CO-dependent transwall gradient and inhibits NO production from nNOS.

Metabolite differences in the lenticular nucleus in type 2 diabetes mellitus shown by proton MR spectroscopy

BACKGROUND AND PURPOSE

Previous studies by using proton MR spectroscopy found metabolite abnormalities in the cerebral cortex and white matter of patients with type 2 diabetes mellitus. The present study was undertaken to detect metabolite differences in the lenticular nuclei and thalamus in patients with T2DM.

MATERIALS AND METHODS

Twenty subjects with T2DM and 22 age-matched control subjects underwent single-voxel MR spectroscopy in the left and right lenticular nuclei and left and right thalami. NAA/Cr and Cho/Cr ratios were calculated. Brain lactic acid, fasting blood glucose, and glycosylated hemoglobin levels were also monitored.

RESULTS

The NAA/Cr ratio was lower in the left lenticular nuclei of subjects with T2DM (P = .007), whereas the Cho/Cr ratio was increased in both the and right lenticular nuclei (P = .001). The NAA/Cr ratio was negatively correlated with FBG in the left (r = -0.573, P = .008) and right nuclei (r = -0.564, P = .010). It was also negatively correlated to HbA1c in the left (r = -0.560, P = .010) and right (r = -0.453, P = .045) nuclei. The Cho/Cr ratio was positively correlated with these variables (P < .05). No significant differences in NAA/Cr or Cho/Cr ratios were observed in the thalamus of patients with T2DM. Lactic acid was not detected in any of the patients in the study.

CONCLUSIONS

The different metabolic statuses of the lenticular nuclei and thalamus suggest different effects of T2DM in each of these brain nuclei, with the lenticular nuclei being more vulnerable than the thalamus. The abnormal metabolic status was observed before lesions had appeared in these brain areas.

Mitotic and meiotic behavior of rye chromosomes in wheat - Psathyrostachys huashanica amphiploid x triticale progeny

The dynamics of rye chromosomes during mitosis and meiosis was analyzed in a subset comprising 33 F3 lines from the cross of wheat, Psathyrostachys huashanica amphiploid (AABBDDNsNs) and hexaploid triticale (AABBRR), as visualized by genomic in situ hybridization. The results indicated that 31 of the total lines contained 4-14 rye chromosomes. Twenty-eight combinations had more rye chromosomes than the F1 hybrids, suggesting the occurrence of spontaneous quantitative increment. No P. huashanica chromosomes were detected in all of the combinations tested. Mitotic analysis showed that rye chromosomes progressed normally with the wheat counterparts without loss. However, abnormal meiosis was found in almost all lines. Similar progression between wheat and rye genomes appeared from interphase to metaphase I. It was at anaphase I that many rye univalents lagged behind those of wheat, followed by equational division. This resulted in the formation of chromosomal segments and micronuclei at telophase I or II. Micronuclei could also be generated from the immobilized univalents in the periphery of cells. Synapsis and translocations between wheat and rye genomes, chromosome bridges, and unreduced gametes were detected. Therefore, it is proposed that rye chromosome elimination may involve chromatid lagging, fragmentation and micronucleation, or the immobilization of certain univalents during meiosis instead of mitosis in the relatively advanced generations. This mechanism, together with spontaneous incremental increase of rye chromosome number, permitted the generation of various germplasms for wheat improvement.

Transcriptional regulation of neurodevelopmental and metabolic pathways by NPAS3

The basic helix-loop-helix PAS (Per, Arnt, Sim) domain transcription factor gene NPAS3 is a replicated genetic risk factor for psychiatric disorders. A knockout (KO) mouse model exhibits behavioral and adult neurogenesis deficits consistent with human illness. To define the location and mechanism of NPAS3 etiopathology, we combined immunofluorescent, transcriptomic and metabonomic approaches. Intense Npas3 immunoreactivity was observed in the hippocampal subgranular zone-the site of adult neurogenesis--but was restricted to maturing, rather than proliferating, neuronal precursor cells. Microarray analysis of a HEK293 cell line over-expressing NPAS3 showed that transcriptional targets varied according to circadian rhythm context and C-terminal deletion. The most highly up-regulated NPAS3 target gene, VGF, encodes secretory peptides with established roles in neurogenesis, depression and schizophrenia. VGF was just one of many NPAS3 target genes also regulated by the SOX family of transcription factors, suggesting an overlap in neurodevelopmental function. The parallel repression of multiple glycolysis genes by NPAS3 reveals a second role in the regulation of glucose metabolism. Comparison of wild-type and Npas3 KO metabolite composition using high-resolution mass spectrometry confirmed these transcriptional findings. KO brain tissue contained significantly altered levels of NAD(+), glycolysis metabolites (such as dihydroxyacetone phosphate and fructose-1,6-bisphosphate), pentose phosphate pathway components and Kreb's cycle intermediates (succinate and α-ketoglutarate). The dual neurodevelopmental and metabolic aspects of NPAS3 activity described here increase our understanding of mental illness etiology, and may provide a mechanism for innate and medication-induced susceptibility to diabetes commonly reported in psychiatric patients.

The 3Ns chromosome of Psathyrostachys huashanica carries the gene(s) underlying wheat stripe rust resistance

Stripe rust (Puccinia striiformis tritici (Pst)) is one of the most destructive diseases of wheat in the world. Exploiting and utilizing stripe rust resistance genes of wild species has become an essential strategy for resistance breeding. Psathyrostachyshuashanica Keng ex Kuo is a wild species in Triticeae that has been used for wheat improvement because of its high resistance or immunity to stripe rust. In this study, 9 wheat-P. huashanica addition lines were characterized by Giemsa C-banding, genomic in situ hybridization (GISH), and disease resistance evaluation. Giemsa C-banding and GISH demonstrated that lines 163-5, 165-1, 183-5, 240-3, and 240-4 are P. huashanica 3Ns chromosome monosomic addition lines; lines 183-1 and 183-20 are P. huashanica 3Ns chromosome disomic addition lines; line 165-20 is a P. huashanica 3Ns and 4Ns chromosomes double disomic addition line, and line 219-1 is a P. huashanica 1Ns and 3Ns/5A chromosomes double disomic addition-substitution line. All these addition lines with P. huashanica 3Ns chromosome(s) expressed high resistance or immunity to stripe rust. By comparing the series of wheat-P. huashanica chromosome addition lines, we concluded that the P. huashanica 3Ns chromosome carries the gene(s) for resistance or immunity to stripe rust. These addition lines can be used as a donor source of novel stripe rust resistance to wheat breeding programs.

The transwall gradient across the mouse colonic circular muscle layer is carbon monoxide dependent

Gastric and small intestinal circular smooth muscle layers have a transwall resting membrane potential (RMP) gradient that is dependent on release of carbon monoxide (CO) from interstitial cells of Cajal (ICCs). Our aim was to determine whether a RMP gradient exists in the mouse colon and whether the gradient is CO dependent. Microelectrodes were used to record RMPs from muscle cells at different depths of the circular muscle layer from wild-type and heme oxygenase-2-knockout (HO-2-KO) mice. A transwall RMP gradient was present in wild-type mice. The CO scavenger oxyhemoglobin (20 μM) and the heme oxygenase inhibitor chromium mesoporphyrin IX (CrMP, 5 μM) abolished the transwall gradient. The gradient was absent in HO-2-KO mice. Tetrodotoxin (1 μM) caused a significant depolarization in circular smooth muscle cells throughout the circular muscle layer and abolished the transwall gradient. Removal of the submucosal neurons abolished the gradient. The majority of submucosal neurons contained HO-2 immunoreactivity (HO-2-IR), while ICCs did not. These data show for the first time that a transwall gradient exists across the circular smooth muscle layer of the mouse colon, that the gradient is due to CO, and that the source of CO is the submucosal neurons.

Species dependent expression of intestinal smooth muscle mechanosensitive sodium channels

A mechanosensitive Na(+) current carried by Na(v)1.5 is present in human intestinal circular smooth muscle and contributes to regulation of intestinal motor function. Expression of this channel in different species is unknown. Our aim was to determine if Na(+) currents and message for the alpha subunit of the Na(+) channel (SCN5A) are found in circular smooth muscle cells of human, dog, pig, mouse and guinea pig jejunum. Currents were recorded using patch clamp techniques. Message for SCN5A was investigated using laser capture microdissection and reverse transcription polymerase chain reaction (RT-PCR). Na(+) currents were identified consistently in human and dog smooth muscle cells; however, Na(+) current was not found in pig (0/20) or guinea pig smooth muscle cells (0/21) and found only one mouse cell (1/21). SCN5A mRNA was found in circular muscle of human, dog, and mouse, but not in pig or guinea pig, and not in mouse longitudinal or mucosal layers. In summary, SCN5A message is expressed in, and Na(+) current recorded from, circular muscle layer of human and dog but not from pig and guinea pig. These data show that there are species differences in expression of the SCN5A-encoded Na(v)1.5 channel, suggesting species-specific differences in the electrophysiological response to mechanical and depolarizing stimuli.

Mediators of non-adrenergic non-cholinergic inhibitory neurotransmission in porcine jejunum

The purpose of this study was to determine the non-adrenergic non-cholinergic inhibitory neurotransmitter in pig jejunum. Intracellular electrical activity was recorded from circular smooth muscle cells. Inhibitory junction potentials (IJPs) evoked by electrical field stimulation were inhibited by tetrodotoxin (1 micromol L(-1)), omega-conotoxin GVIA (0.1 micromol L(-1)) tetrodotoxin, apamin (1 micromol L(-1)), 1-[6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl]-1H-pyrrole-2,5-dione (U-73122; 10 micromol L(-1)) but not by N omega-nitro-l-arginine (l-NNA; 100 micromol L(-1)), haemoglobin (10 micromol L(-1)), 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; 10 micromol L(-1)) or 9-(tetrahydro-2-furyl)adenine (SQ-22536; 10 micromol L(-1)). S-nitroso-N-acetylpenicillamine (SNAP) hyperpolarized the membrane potential. This was inhibited by ODQ (3 micromol L(-1)) and charybdotoxin (0.1 micromol L(-1)). Adenosine-5-triphosphate (ATP; 100 micromol L(-1)) and 2-methylthio ATP (2-MeS-ATP; 100 micromol L(-1)) did not hyperpolarize the membrane potential and 6-N-N-diethyl-beta- gamma -dibromomethylene-d-adenosine-5'-triphosphate (ARL67156; 100 micromol L(-1)) did not modify IJPs. Carbon monoxide (CO; 10%) and tricarbonyl dichlororuthenium dimer ([Ru(CO3Cl2)]2; 100 micromol L(-1)) hyperpolarized the membrane potential however zinc, copper and tin protoporphyrin IX (100 micromol L(-1)) did not alter IJPs. Vasoactive intestinal peptide (VIP) hyperpolarized the membrane potential but 4-Cl-d-Phe6-Leu17-VIP (1 micromol L(-1)) did not modify IJPs. Pituitary adenylate cyclase activating peptide (PACAP)38 (0.5 micromol L(-1)) hyperpolarized the membrane potential. This was inhibited by apamin (1 micromol L(-1)) but not by tetrodotoxin (1 micromol L(-1)). Pituitary adenylate cyclase activating peptide6-38 (1 micromol L(-1)) inhibited IJPs. These data suggest that inhibitory neurotransmission in pig jejunum is mediated partly by PACAP.

Kit/stem cell factor receptor-induced phosphatidylinositol 3'-kinase signalling is not required for normal development and function of interstitial cells of Cajal in mouse gastrointestinal tract

Signalling mediated by the receptor tyrosine kinase c-Kit is required for normal development of interstitial cells of Cajal (ICC). c-Kit activates several signalling pathways, including the phosphatidylinositol 3'-kinase (PI3'-kinase) pathway. The signals required for ICC development and maintenance are not well understood. Studies indicate a role for PI3'-kinase. We studied ICC function and morphology in mice homozygous for the tyrosine 719 to phenylalanine c-Kit mutation, which disrupts all PI3'-kinase binding to c-Kit. Functionally, the electrical slow waves in the jejunum and inhibitory junction potentials were normal in adult mutants. Morphologically, the distribution of ICC was not altered in mutants. There was no difference in the density of ICC in the jejunum of adults or newborns from quantitative analysis of c-Kit immunoreactivity. The number of ICC obtained in culture was the same using mutants or wild-type littermates. The density and organization of nerves in the jejunum of mutants was not affected. Deletion of c-Kit-induced PI3'-kinase signalling does not affect the function or development of ICC in the mouse. This is an important and counterintuitive result, given the role of PI3'-kinase signalling downstream of c-Kit and the role of both c-Kit and PI3'-kinase individually in ICC development.

Nutrient cycling in a tropical seasonal rain forest of Xishuangbanna, Southwest China. Part 1: tree species: nutrient distribution and uptake

Tropical rain forests are characterized by large numbers of the species with diverse growth habits. The objective of the present study was to determine the distribution of nutrient content in the major trees of the tropical rain forests in Xishuangbanna. This will improve the understanding of the nutrient losses from such sites that result from harvesting and flow of nutrients within the ecosystem and lead to the development of effective and rational forest management strategies. Based on the results in this study, the distribution of nutrients among biomass components of trees varied: The ordering of major elements concentrations was K > N > Mg > Ca > P in branch, stem and root tissues but was N > K > Mg > Ca > P in leaves. The maximum amount of all nutrients per ha occurred in the stems followed by branches, roots and leaves. Of the total uptake of 6167.7 kg ha(-1) of all nutrients, the contribution of various nutrients was found to be N (2010.6 t ha(-1)), P (196.3 t ha(-1)), K (2123.8 kg ha(-1)), Ca (832 kg ha(-1)) and Mg (1005 kg ha(-1)). However, comparing the nutrient uptake of other tropical and sub tropical forests, the results indicated that rates for the Xishuangbanna forests were 20-35% lower than previously reported values.

[Species composition and diversity of soil mesofauna in the 'Holy Hills' fragmentary tropical rain forest of Xishuangbanna, China]

The species composition and diversity of soil mesofauna were examined in fragmented dry tropical seasonal rainforest of tow 'Holy Hills' of Dai nationality, compared with the continuous moist tropical seasonal rain forest of Nature Reserve in Xishuangbanna area. 5 sample quadrats were selected along the diagonal of 20 m x 20 m sampling plot, and the samples of litterfall and 0-3 cm soil were collected from each 50 cm x 10 cm sample quadrat. Animals in soil sample were collected by using dry-funnel(Tullgren's), were identified to their groups according to the order. The H' index, D.G index and the pattern of relative abundance of species were used to compare the diversity of soil mesofauna. The results showed that the disturbance of vegetation and soil resulted by tropical rainforest fragmentation was the major factor affecting the diversity of soil mesofauna. Because the fragmented forest was intruded by some pioneer tree species and the "dry and warm" effect operated, this forest had more litterfall on the floor and more humus in the soil than the continuous moist rain forest. The soil condition with more soil organic matter, total N and P, higher pH value and lower soil bulk density became more favorable to the soil mesofauna. Therefore, the species richness, abundance and diversity of soil mesofauna in fragmented forests were higher than those in continuous forest, but the similarity of species composition in fragmented forest to the continuous forest was minimal. Soil mesofauna diversity in fragmented forests did not change with decreasing fragmented area, indicating that there was no species-area effect operation in this forest. The pattern of relative abundance of species in these forest soils was logarithmic series distribution.

Electrophysiological effects of GABA on cat pancreatic neurons

In mammalian peripheral sympathetic ganglia GABA acts presynaptically to facilitate cholinergic transmission and postsynaptically to depolarize membrane potential. The GABA effect on parasympathetic pancreatic ganglia is unknown. We aimed to determine the effect of locally applied GABA on cat pancreatic ganglion neurons. Ganglia with attached nerve trunks were isolated from cat pancreata. Conventional intracellular recording techniques were used to record electrical responses from ganglion neurons. GABA pressure microejection depolarized membrane potential with an amplitude of 17.4 +/- 0.7 mV. Electrically evoked fast excitatory postsynaptic potentials were significantly inhibited (5.4 +/- 0.3 to 2.9 +/- 0.2 mV) after GABA application. GABA-evoked depolarizations were mimicked by the GABA(A) receptor agonist muscimol and abolished by the GABA(A) receptor antagonist bicuculline and the Cl(-) channel blocker picrotoxin. GABA was taken up and stored in ganglia during preincubation with 1 mM GABA; beta-aminobutyric acid application after GABA loading significantly (P < 0.05) increased depolarizing response to GABA (15.6 +/- 1.0 vs. 7.8 +/- 0.8 mV without GABA preincubation). Immunolabeling with antibodies to GABA, glial cell fibrillary acidic protein, protein gene product 9.5, and glutamic acid decarboxylase (GAD) immunoreactivity showed that GABA was present in glial cells, but not in neurons, and that glial cells did not contain GAD, whereas islet cells did. The data suggest that endogenous GABA released from ganglionic glial cells acts on pancreatic ganglion neurons through GABA(A) receptors.

Amplitude modulation of pulsatile insulin secretion by intrapancreatic ganglion neurons

Neuron activity and insulin release were measured simultaneously from 33 preparations of intrapancreatic canine ganglia and pancreatic parenchyma adjacent to the ganglia. The electrical activity of single neurons of the ganglia was recorded with intracellular microelectrodes, and insulin release from the attached islets was determined with an enzyme-linked immunosorbent assay. Insulin release was 62 +/- 18 fmol preparation/min in the presence of 10 mmol/l glucose and pulsatile (3.7 +/- 0.4 min/pulse). Corresponding measurements of neuronal electrical activity showed a stable membrane potential of -53.5 +/- 0.6 mV. Short, high-frequency (20 Hz) preganglionic nerve stimulation evoked action potentials and, in 46% of the preparations, a threefold rise in the insulin secretory rate associated with increased amplitude of the insulin pulses. The effects were blocked by 10 micromol/l tetrodotoxin (TTX). In other preparations, continuous low-frequency (0.05-0.5 Hz) preganglionic nerve stimulation evoked action potentials and, in 50% of the preparations, a gradual increase of insulin release associated with augmentation of insulin pulse amplitude without alteration of the duration. The effects were blocked by 50 micromol/l hexamethonium (HEX). In the remaining preparations, no change in insulin release was observed during nerve stimulation. In the absence of stimulation, neither TTX nor HEX affected the membrane potential or insulin secretion. These first simultaneous measurements of intrapancreatic ganglion activity and insulin secretion are consistent with amplitude modulation of pulsatile insulin secretion induced by changes in electrical activity in a population of intrapancreatic ganglion neurons.

Protein A tangential flow affinity membrane cartridge for extracorporeal immunoadsorption therapy

Tangential flow affinity membrane cartridge (TFAMC) is a new model of immunoadsorption therapy for hemoperfusion. Recombinant Protein A was immobilized on the membrane cartridge through Schiff base formation for extracorporeal IgG and immune complex removal from blood. Flow characteristics, immunoadsorption capacity and biocompatibility of protein A TFAMC were studied. The results showed that the pressure drop increased with the increasing flow rate of water, plasma and blood, demonstrating reliable strength of membrane at high flow rate. The adsorption capacities of protein A TFAMC for IgG from human plasma and blood were measured. The cartridge with 139 mg protein A immobilized on the matrix (6 mg protein A/g dry matrix) adsorbed 553 mg IgG (23.8 mg IgG/g dry matrix) from human plasma and 499.4 mg IgG (21.5 mg IgG/g dry matrix) from human blood, respectively. The circulation time had a major influence on IgG adsorption capacity, but the flow rate had little influence. Experiments in vitro and in vivo confirmed that protein A TFAMC mainly adsorbed IgG and little of other plasma proteins, and that blood cell damage was negligible. The extracorporeal circulation system is safe and reliable.

Leptin modulates fast synaptic transmission in dog pancreatic ganglia

The aim of this study was to determine whether leptin modulates neuronal activity in intrapancreatic ganglion neurons. Intracellular recordings were made in dog pancreatic neurons. Recombinant mouse leptin (313 nM) was added by superfusion. When leptin was present, fast EPSPs which were subthreshold in normal Krebs solution reached threshold for firing action potentials. However, leptin had no significant (P > 0.05, n = 18) effect on either the resting membrane potential or on membrane input resistance. To determine whether leptin increased the postsynaptic sensitivity to acetylcholine, the response was tested by pressure ejection of acetylcholine. Acetylcholine evoked a 9.4+/-2.2 mV (mean +/- SEM, n = 5) depolarization in normal Krebs solution. In the presence of leptin, the response was not significantly different (9.6+/-2.4 mV, P > 0.05). The results suggest that leptin modulates fast synaptic transmission in pancreatic ganglion neurons by acting on presynaptic nerve terminals.

[Protein A tangential flow membrane chromatographic column used for immunoadsorption therapy]

Tangential flow membrane chromatographic column is a new model of immunoadsorption therapy from blood. The results showed that the structure of the column and the flowing channel had a little damages for blood cells. The relation of flow-rate and backpressure with water, plasma and blood individually as the fluid flowing through the column has been studied. It was observed that backpressures increased with fluid viscosity, when flow-rate of blood was 120 mL/min and the backpressure reached 0.093 MPa; The adsorption capacity of protein A of the column for IgG from human plasma has been measured. When plasma and blood individually circulated through the column for 1 h, the column with 139 mg protein A immobilized on the matrix (6 mg protein A/g dry matrix) adsorbed 553 mg IgG (23.8 mg IgG/g dry matrix) from human plasma and 499.4 mg IgG (21.5 mg IgG/g dry matrix) from human blood respectively. The circulation time had a great influence on IgG adsorption capacity; but the circulation rate had a little influence on IgG adsorption capacity. The result of extracoporeal blood perfusion for dog showed that the Protein A column has good blood biocompatibility.

Nocturnal reduction of blood pressure and the antihypertensive response to a diuretic or angiotensin converting enzyme inhibitor in obese hypertensive patients. TROPHY Study Group

During a 12-week, multicenter study to evaluate the efficacy and safety of lisinopril and hydrochlorothiazide (HCTZ) for the treatment of obesity-related hypertension, ambulatory blood pressure (ABP) monitoring was performed both at baseline and at study completion in 124 patients. Patients were randomized to three groups: placebo, lisinopril (10, 20, or 40 mg/day), or HCTZ (12.5, 25, or 50 mg/day). All groups were matched with regard to sex, race, age, body mass index, and waist/hip ratio. The primary analysis of ABP data revealed that both lisinopril and HCTZ effectively lowered mean 24-h systolic (SBP) and diastolic (DBP) blood pressure compared with placebo, (mean change from baseline SBP/DBP: -12.0/-8.2, -10.6/-5.5, and -0.3/-0.5 mm Hg, respectively); however, lisinopril lowered DBP better than HCTZ (P < .05). Secondary analyses of groups revealed that men responded better to lisinopril than HCTZ (-11.9/-7.3 v -6.6/-3.5 mm Hg, respectively), whereas women responded well to both drugs. White patients responded better to lisinopril than HCTZ, whereas black patients showed a significant response to HCTZ only. Response to treatment was also influenced by patient classification of 24-h blood pressure profiles, ie, "dipper" or "nondipper." Overall, the majority of obese hypertensives were nondippers. Nondippers (n = 82) responded well to both drugs (-10.4/-6.9 v -12.5/-5.7 mm Hg, P < .05 v placebo), whereas dippers (n = 42) responded to lisinopril (-11.7/ -9.4 mm Hg, P < .05 v placebo and HCTZ), but not HCTZ (-5.6/-4.1 mm Hg, P = NS v placebo). Results of 24-h ABP data show that both lisinopril and HCTZ are effective therapies for obesity-related hypertension and that response to treatment is influenced by sex, race, and dipper/nondipper status.

Cholinergic transmission in pancreatic ganglia of the cat

Although there is considerable evidence indicating the existence of important cholinergic neural regulation of pancreatic function, very little is known about the action of acetylcholine on pancreatic ganglion neurons. The present study was undertaken to determine the effect of pressure microejection of acetylcholine and muscarine on ganglion cell excitability of the cat pancreas. Recordings were made in vitro from ganglion neurons located in the head region of the pancreas. Acetylcholine evoked a fast- and a slow-developing membrane depolarization in the majority of neurons tested. A decrease in membrane input resistance accompanied the fast depolarizing response, whereas an increase in input resistance accompanied the slow depolarizing response. The fast response was mimicked by 1,1-dimethyl-4-phenylpiperazinium iodide and nicotine and antagonized by hexamethonium. The slow depolarizing response was mimicked by muscarine and antagonized by atropine and pirenzepine. The dependence of the slow depolarization on extracellular K+ and the distinct voltage dependence of the slow depolarization suggest that activation of muscarinic receptors was due to inactivation of IM. The slow excitatory postsynaptic potential and associated increase in excitability evoked by repetitive nerve stimulation was partially cholinergic dependent in the majority of neurons tested. It was concluded that cholinergic transmission in cat pancreatic ganglia involves nicotinic and M1 receptors that mediate fast and slow synaptic transmission, respectively, and that activation of M1 receptors modifies the output firing frequency.

Cat pancreatic neurons: morphology, electrophysiological properties, and responses to 5-HT

Light and confocal microscopy was used to study the anatomy and morphology of cat pancreatic ganglia. Intracellular microelectrodes were used to examine the electrophysiological properties of neurons in the head, body, and tail regions of the pancreas and to compare their responses to 5-hydroxytryptamine (5-HT). Pancreatic ganglia were oval shaped, joined by interconnecting nerves. Several head to tail gradients were found: (1) ganglion cell numbers decreased from head to tail; (2) the incidence of ongoing synaptic activity was higher for neurons located in the head region; (3) ganglion neurons in the head region received a greater number of converging synaptic inputs; (4) a greater percentage of neurons in the head region responded to 5-HT; (5) a greater percentage of neurons in the head region exhibited depolarizing responses mediated by 5-HT3 receptors; and (6) late slow-excitatory postsynaptic potentials recorded from neurons in the head region were more often antagonized by 5-HT1P receptor antagonists. It was concluded that cat pancreatic ganglia are sites of convergence and integration of synaptic inputs arriving from multiple sources. Serotonergic inputs from enteropancreatic nerves, if they exist in the cat pancreas, would be expected to have a significant influence on the excitability of neurons located in the head region compared to neurons located in the tail region of the pancreas.

Nitric oxide is a neuromodulator in cat pancreatic ganglia: histochemical and electrophysiological study

This study examined the distribution of NADPH-diaphorase (NADPH-d) activity in cat pancreatic ganglia and the electrophysiological effects of nitric oxide (NO) donors, NO and the effect of endogenously released NO. The majority (64%) of pancreatic ganglion neurons stained positive for NADPH-d. Large nerve trunks contained numerous non-varicose NADPH-d positive fibers. NADPH-d positive nerve fibers within individual ganglia were varicosed. L-Arginine, sodium nitroprusside and NO, applied in the vicinity of the impaled neuron, evoked a hyperpolarizing response and initiated fast excitatory postsynaptic potentials (EPSPs) in the majority of neurons tested. The hyperpolarizing response was not affected by low Ca2+ (0.1 mM), high Mg2+ (15 mM). Pretreatment with nitro-L-arginine increased the amplitude of slow EPSPs in about 50% of neurons tested. These results support the hypothesis that NO plays a role in ganglionic transmission in the cat pancreas.

Anticomplement activity in human aqueous humor

Twenty-six samples of human aqueous humor from patients with cataract and glaucoma were analyzed on anticomplement activity. The mean inhibitory rate was 15.32 +/- 14.60%, ranging from 0.93 to 60.02%. The inhibitory effect appeared in a dose-dependent manner. No significant differences were found between males and females (p > 0.05) and between samples of different age (p > 0.05). We revealed that aqueous humor had an inhibitory effect on complement activity. This indicates that human aqueous humor has an immune regulatory function.

Enzyme characteristics of two distinct forms of mouse 3 beta-hydroxysteroid dehydrogenase/delta 5-delta 4-isomerase complementary deoxyribonucleic acids expressed in COS-1 cells

The enzyme 3 beta-hydroxysteroid dehydrogenase/delta 5-delta 4-Isomerase (3 beta HSD) catalyzes the conversion of delta 5-3 beta-hydroxysteroids to delta 4-3-ketosteroids, an essential step in the biosynthesis of all biologically active steroid hormones. We previously reported the isolation of three distinct mouse cDNAs for 3 beta HSD (3 beta HSD I, II, and III) and tissue-specific expression of their mRNAs. 3 beta HSD I is expressed only in gonads and adrenal glands, and 3 beta HSD II and III are expressed in both liver and kidneys. In the current study, we present data which demonstrate that transiently expressed 3 beta HSD I and 3 beta HSD III proteins can catalyze the conversion of the delta 5-steroids, pregnenolone and dehydroepiandrosterone, to their respective delta 4-3-ketosteroids, progesterone and androstenedione. They also can dehydrogenate the 3 beta-hydroxy group of the 5 alpha-reduced steroid 5 alpha-androstanediol to yield dihydrotestosterone in the presence of the cofactor NAD+. The Km values of the expressed 3 beta HSD I (for each of these substrates) were all below 0.2 microM. Km values of 3 beta HSD III were greater for all substrates, with the greatest increase observed for pregnenolone, which was over 10-fold greater. Both forms of expressed protein can catalyze the reduction of dihydrotestosterone to 5 alpha-androstanediol in the presence of the cofactor NADH, but with considerably higher Km values (5.5 microM for form I and 6.8 microM for form III). The observed maximum velocity of form I was much higher for all substrates examined. RNase protection and immunoblot analysis of expressed 3 beta HSD I and III indicate that the difference in maximum velocity reflect differences in the steady state levels of mRNA and amounts of protein. In addition, the expressed 3 beta HSD III protein analyzed by Western blot has a lower mobility than the 3 beta HSD I protein, both similar in mol wt to the 3 beta HSD proteins detected in mouse liver and adrenal glands, respectively. These data demonstrate that an isoform of 3 beta HSD expressed in liver and kidney has the capacity to convert delta 5-3 beta-hydroxysteroids to delta 4-3-ketosteroids. The data suggest that a homologous human 3 beta HSD isoform could play an important role in cases of genetic deficiency of the gonadal and adrenal isoform.

Hormonal regulation of steroidogenic enzyme gene expression in Leydig cells

In normal mouse Leydig cells, steady state levels of mRNA of CYP11A, 3β-hydroxysteroid dehydrogenase Δ⁵- >Δ⁴-isomerase (3βHSD), and CYP17 are differentially regulated. There is high basal expression of 3βHSD and CYP11A mRNA, while expression of CYP17 mRNA is absolutely dependent on cAMP stimulation. cAMP is required for maximal expression of all three enzymes. The expression of CYP11A in normal mouse Leydig cells is repressed by glucocorticoids. Glucocorticoids also repress both basal and cAMP-induced expression of 3βHSD mRNA, but do not repress the synthesis or mRNA levels of CYP17. cAMP induction of 3βHSD mRNA can be observed only when aminoglutethimide (AG), an inhibitor of cholesterol metabolism, is added to the Leydig cell cultures. The addition of AG also markedly increases cAMP induction of CYP17 mRNA levels. Addition of testosterone or the androgen agonist, mibolerone, to cAMP plus AG treated cultures reduced 3βHSD and CYP17 mRNA levels to levels comparable to those observed when cells were treated with cAMP only. These data indicate that testosterone acting via the androgen receptor represses expression of both CYP17 and 3βHSD. The role of protein synthesis in mediating the cAMP induction of 3βHSD, CYP17 and CYP11A was examined. The addition of cycloheximide, an inhibitor of protein synthesis, to cAMP treated cultures for 24 h completely suppressed both constitutive and cAMP-induced 3βHSD mRNA levels. Cycloheximide also repressed cAMP-induced levels of CYP17 to 12% of levels observed in the absence of cycloheximide. In sharp contrast, treatment for 24 h with cycloheximide did not suppress cAMP induction of CYP11A mRNA, but reduced basal levels by approx. 50%. These data indicate that newly synthesized protein(s) are required for cAMP induction of CYP17 and 3βHSD mRNA levels, but not for CYP11A mRNA. A mouse Cyp17 genomic clone containing the entire coding region plus 10 kb of 5' flanking region has been isolated. Fragments of 5' flanking sequences were subcloned into vectors containing the CAT reporter gene and transfected into MA-10 Leydig cells. Transfected cells were treated with cAMP and expression was determined by measuring CAT activity. A cAMP responsive element was identified in a region between -245 and -346 bp relative to the transcription initiation site of Cyp17. Cotransfection into MA-10 Leydig cells of constructs containing 4.5 kb of Cyp17 5' flanking sequences together with a mouse androgen receptor expression vector demonstrate a dose dependent repression of cAMP-induced Cyp17 transcription by the androgen receptor. Studies with the mouse Cyp11a gene demonstrate that the 5' flanking region of the gene contains sequences between 2.5 and 5 kb that are necessary for expression of mouse Cyp11a in Leydig cells but not in adrenal cells.

Glucocorticoid and cyclic adenosine 3'5'-monophosphate-mediated induction of cholesterol side-chain cleavage cytochrome P450 (P450scc) in MA-10 tumor Leydig cells. Increases in mRNA are cycloheximide sensitive

The regulation of cholesterol side-chain cleavage enzyme (P450scc) was investigated in MA-10 tumor Leydig cells. We recently demonstrated that the constitutive and cAMP-stimulated expression of P450scc in normal mouse Leydig cells is negatively regulated by glucocorticoids. We now report that glucocorticoids have the opposite effect in MA-10 cells causing a 1.7-fold increase in the rate of P450scc synthesis and a 2.1-fold increase in the amount of P450scc mRNA. Treatment of MA-10 cells with 10 microM 8-bromo-cAMP (8-Br-cAMP) (cAMP) resulted in a 1.7-fold increase in P450scc synthesis and a 3-fold increase in P450scc mRNA. Combined treatment with dexamethasone and cAMP resulted in additive increases in synthesis (2.8-fold) and mRNA (5.3-fold). Increases in de novo synthesis and mRNA levels were reflected by modest increases in the amount of immunoreactive P450scc enzyme protein. Dexamethasone-mediated stimulation in synthesis and accumulation of P450scc mRNA were blocked by the antiglucocorticoid RU-486. Cycloheximide blocked both cAMP- and dexamethasone-induced increases but had no effect on constitutive levels of P450scc mRNA. Treatment of MA-10 cells with 10 microM 8-Br-cAMP had no effect on cell morphology and stimulated progesterone accumulation to a minor degree. Treatment of MA-10 cells with 1 mM 8-Br-cAMP resulted in cell rounding and loss of cells from culture dishes. The results of this study demonstrate that: 1) dexamethasone increases P450scc de novo synthesis and mRNA levels in MA-10 tumor Leydig cells, opposite to the effect in normal Leydig cells; 2) dexamethasone- and cAMP-stimulated increases occur via distinct mechanisms; 3) and synthesis of protein factor(s) is required to mediate the action of both dexamethasone and cAMP.

Association of Ki-ras with amplified DNA sequences, detected in human ovarian carcinomas by a modified in-gel renaturation assay

A modified in-gel DNA renaturation technique, which detects DNA sequences amplified greater than 7-fold in human DNA, was used to analyze gene amplification in surgical specimens of primary and metastatic ovarian carcinomas. Amplified DNA sequences were detected in two of eight tumors. Hybridization of these samples with different oncogene probes revealed that both tumors contained an amplified Ki-ras gene, which in one case was coamplified with c-myc. In one of the tumors, Ki-ras was found to be amplified in both the primary tumor and three different metastatic nodules. No mutations at codons 12 or 61 of Ki-ras were detected in these tumors. No additional cases of Ki-ras or c-myc amplification were detected by Southern hybridization in the tumors that were found to be amplification negative by modified in-gel renaturation assays. These results indicate that gene amplification in ovarian carcinomas is likely to involve the Ki-ras oncogene.

trans-activation and autoregulation of gene expression by the immediate-early region 2 gene products of human cytomegalovirus

The major immediate-early (IE) gene region mapping at coordinates 0.71 to 0.74 in the genome of human cytomegalovirus (HCMV) gives rise to a series of overlapping spliced IE mRNAs that are all under the transcriptional control of the complex IE68 promoter-enhancer region. We show here that one of the phosphorylated nuclear proteins encoded by this region behaves as a powerful but nonspecific trans-activator of gene expression. In transient chloramphenicol acetyltransferase (CAT) assay experiments with Vero cells all relatively weak heterologous target promoters tested, including those of herpes simplex virus IE175 and delayed-early genes, adenovirus E3, the enhancerless simian virus 40 early gene, and the human beta interferon gene, were stimulated between 30- and 800-fold by cotransfection with the HindIII C fragment of HCMV (Towne) DNA. In contrast, expression of the homologous HCMV IE68-CAT gene but not SV2-CAT was specifically repressed. Inactivation mapping studies of the effector DNA, together with dose-response comparisons with subclones from the region, revealed that an intact 7.1-kilobase sequence encompassing both the IE1 and IE2 coding regions (exons 1 to 5) in the major IE transcription complex was required for both the nonspecific trans-activation and autoregulatory responses. The IE1 coding region alone (exons 1 to 4) was inactive, but both functions were restored by insertion of the IE2 coding region (exon 5) in the correct orientation downstream from the IE1 coding region. Internal deletions or inserted terminator codons in IE1 (exon 4) still gave efficient trans-activation and autoregulation, whereas the insertion of terminator codons in IE2 (exon 5) abolished both activities. Finally, IE2 (exon 5) sequences only (under the direct transcriptional control of the strong simian CMV IE94 promoter) were still able to specifically down regulate IE68-CAT expression but failed to exhibit trans-activation properties. Therefore, the IE2 gene product(s) of HCMV appear likely to be key control proteins involved in gene regulation during HCMV infection.