[Utilization of basic medical insurance data in cancer-related researches in China]

Objective: To explore the utilization of cancer-related data from basic medical insurance databases in China, and promote the application of medical insurance data in cancer prevention and treatment. Methods: Database PubMed, Web of Science, Wanfang, and CNKI were used to select related research papers using data from basic medical insurance system in China published by December 2021. Descriptive analysis was conducted in terms of the number of publications, types of cancer, primary research contents and author affiliations. Results: A total of 65 papers were included in the study. The number of publications increased rapidly after 2016. The most studied cancer type was lung cancer, and healthcare costs were the most common research contents. Fujian, Beijing, and Anhui have made a better use of cancer-related medical insurance databases compared to other provincial regions. The accessibility of the New Rural Cooperative Medical Scheme data was limited due to the high regional barriers, while the accessibility of the urban basic medical insurance data was relatively high. The researchers from Peking University and Fudan University had higher utilization of basic medical insurance data compared with those from other institutions. Conclusions: The utilization of cancer-related data from basic medical insurance databases in China is limited because of poor accessibility, insufficient data sharing, and regional restrictions. Thus, it is urgent to improve data accessibility and promote the integration and utilization of regional medical insurance data.

An improved method for determining frequency of multiple variants of SARS-CoV-2 in wastewater using qPCR assays

Wastewater-based surveillance has become an effective tool around the globe for indirect monitoring of COVID-19 in communities. Variants of Concern (VOCs) have been detected in wastewater by use of reverse transcription polymerase chain reaction (RT-PCR) or whole genome sequencing (WGS). Rapid, reliable RT-PCR assays continue to be needed to determine the relative frequencies of VOCs and sub-lineages in wastewater-based surveillance programs. The presence of multiple mutations in a single region of the N-gene allowed for the design of a single amplicon, multiple probe assay, that can distinguish among several VOCs in wastewater RNA extracts. This approach which multiplexes probes designed to target mutations associated with specific VOC's along with an intra-amplicon universal probe (non-mutated region) was validated in singleplex and multiplex. The prevalence of each mutation (i.e. VOC) is estimated by comparing the abundance of the targeted mutation with a non-mutated and highly conserved region within the same amplicon. This is advantageous for the accurate and rapid estimation of variant frequencies in wastewater. The N200 assay was applied to monitor frequencies of VOCs in wastewater extracts from several communities in Ontario, Canada in near real time from November 28, 2021 to January 4, 2022. This includes the period of the rapid replacement of the Delta variant with the introduction of the Omicron variant in these Ontario communities in early December 2021. The frequency estimates using this assay were highly reflective of clinical WGS estimates for the same communities. This style of qPCR assay, which simultaneously measures signal from a non-mutated comparator probe and multiple mutation-specific probes contained within a single qPCR amplicon, can be applied to future assay development for rapid and accurate estimations of variant frequencies.

[Analysis on the status quo of the awareness rate of core knowledge of cancer prevention and treatment and its influencing factors among residents in Liaoning Province in 2021]

Objective: To analyze the status quo of the knowledge and related factors of cancer prevention and treatment among residents in Liaoning Province in 2021. Methods: From August to November 2021, through network sampling method, 17 474 permanent residents aged 15-69 years in Liaoning Province were surveyed. The WeChat public account was used to collect information such as demographic characteristics and core knowledge of cancer prevention and treatment. The Chi-square test was used to compare the difference of the level of the cancer prevention and treatment knowledge among different groups. The multivariate logistic regression model was used to analyze the related factors. Results: Among the 17 474 subjects, 43.1% (7 528) were male and 58.7% (10 262) were urban residents. The overall awareness rate was 72.3%, and the awareness rate of cancer cognition, prevention, early diagnosis and treatment, cancer management and rehabilitation were 71.4%, 67.6%, 72.7%, 83.4% and 63.5%, respectively. The multivariate logistic regression model showed that the residents who were man (OR: 0.850, 95%CI: 0.781-0.925), in rural areas (OR: 0.753, 95%CI: 0.694-0.817), 55-59 years old (OR: 0.851, 95%CI: 0.751-0.963), quitters (OR: 0.721, 95%CI: 0.640-0.813) and smoker (OR: 0.724, 95%CI: 0.654-0.801) had lower awareness rates, while the residents who were 35-54 years old (OR: 1.312, 95%CI: 1.202-1.432), with an educational level of junior high school/senior high school/college degree or above (OR: 1.834-5.130, 95%CI: 1.575-6.047), technical personnel (OR: 1.592, 95%CI: 1.367-1.854), civil servant/institution staff (OR: 1.282, 95%CI: 1.094-1.503), enterprise/business/service staff (OR: 1.218, 95%CI: 1.071-1.385), retired (OR: 1.324, 95%CI: 1.114-1.573) and with family history of cancer (OR: 1.369, 95%CI: 1.266-1.481) had higher awareness rates. Conclusion: The level of the awareness of core knowledge of cancer prevention and treatment among residents in Liaoning Province has met the requirements of the Healthy China Action. Region, gender, education level, age, family history of cancer and smoking are relevant factors.

Irisin in atherosclerosis

Irisin, a novel exercise-induced myokine, has been shown to play important roles in increasing white adipose tissue browning, regulating energy metabolism and improving insulin resistance. Growing evidence suggests a direct role for irisin in preventing atherosclerosis (AS) by inhibiting oxidative stress, improving dyslipidemia, facilitating anti-inflammation, reducing cellular damage and recovering endothelial function. In addition, some studies have noted that serum irisin levels play an essential role in cardiovascular diseases (CVDs) risk prediction, highlighting that irisin has the potential to be a useful predictive marker and therapeutic target of AS, especially in monitoring therapeutic efficacy. This review summarizes the understanding of irisin-mediated regulation in essential biological pathways and functions in atherosclerosis and prompts further exploitation of the biological properties of irisin in the pathogenesis of atherosclerosis.

Genome-wide scanning for CHD1L gene in papillary thyroid carcinoma complicated with type 2 diabetes mellitus

PURPOSE

Papillary thyroid carcinoma (PTC) represents the most common subtype of thyroid cancer (TC). This study was set out to explore the potential effect of CHD1L on PTC and type 2 diabetes mellitus (T2DM).

METHODS

We searched for T2DM susceptibility genes through the GWAS database and obtained T2DM-related differentially expressed gene from the GEO database. The expression and clinical data of TC and normal samples were collated from the TCGA database. Receiver operating characteristic (ROC) curve analysis was subsequently applied to assess the sensitivity and specificity of the CHD1L for the diagnosis of PTC. The MCP-counter package in R language was then utilized to generate immune cell score to evaluate the relationship between CHD1L expression and immune cells. Then, we performed functional enrichment analysis of co-expressed genes and DEGs to determine significantly enriched GO terms and KEGG to predict the potential functions of CHD1L in PTC samples and T2DM adipose tissue.

RESULTS

From two genes (ABCB9, CHD1L) were identified to be DEGs (p < 1 * 10^-5) that exerted effects on survival (HR > 1, p < 0.05) in PTC and served as T2DM susceptibility genes. The gene expression matrix-based scoring of immunocytes suggested that PTC samples with high and low CHD1L expression presented with significant differences in the tumor microenvironment (TME). The enrichment analysis of CHD1L co-expressed genes and DEGs suggested that CHD1L was involved in multiple pathways to regulate the development of PTC. Among them, Kaposi sarcoma-associated herpesvirus infection, salmonella infection and TNF signaling pathways were highlighted as the three most relevant pathways. GSEA analysis, employed to analyze the genome dataset of PTC samples and T2DM adipose tissue presenting with high and low expression groups of CHD1L, suggests that these differential genes are related to chemokine signaling pathway, leukocyte transendothelial migration and TCELL receptor signaling pathway.

CONCLUSION

CHD1L may potentially serve as an early diagnostic biomarker for PTC, and a target of immunotherapy for PTC and T2DM.

Chemerin in atherosclerosis

Atherosclerosis (AS), a chronic arterial disease, is characterized by endothelial dysfunction, inflammatory reactions and lipid accumulation in parallel with aberrant angiogenesis and vascular smooth muscle cell (VSMC) proliferation. Adipose tissue has been suggested to have an integral influence on metabolism and endocrine secretion, while there have been increasing concerns about the possible involvement of adipokines in cardiovascular diseases, including AS. Here, we focused on chemerin, an adipokine highly expressed in adipose tissue, with strong evidence of an association with inflammation, endothelial dysfunction, metabolic disorder, aberrant angiogenesis, VSMC proliferation and calcification. In this review, we discuss chemerin and its receptors in the pathogenesis of AS. However, the existing data assign various, even contradictory, roles to chemerin in atherosclerosis, such as inhibiting vascular calcification and impairing endothelial function. Current studies focusing on its anti- and pro-atherogenic effects have pinpointed its distinct role in specific cell types and contexts in the pathogenesis of atherosclerosis. Therefore, the gaps in current knowledge regarding the specific role played by chemerin in the etiology of AS require additional future studies. It seems reasonable to suggest that targeted chemerin therapy can be developed as an innovative approach for treating AS.

Adipokines in vascular calcification

Adipose tissue (AT), a critical endocrine gland, is capable of producing and secreting abundant adipokines. Adipokines act on distant or adjacent organ tissues via paracrine, autocrine, and endocrine mechanism, which play attractive roles in the regulation of glycolipid metabolism and inflammatory response. Increasing evidence shows that adipokines can connect obesity with cardiovascular diseases by serving as promoters or inhibitors in vascular calcification. The chronic hypoxia in AT, caused by the adipocyte hypertrophy, is able to trigger imbalanced adipokine generation, which leads to apoptosis, osteogenic differentiation of vascular smooth muscle cells (VSMCs), vascular inflammation, and abnormal deposition of calcium and phosphorus in the vessel wall. The objectives of this review aim at providing a brief summary of the crucial influence of major adipokines on the formation and development of vascular calcification, which may contribute to better understanding these adipokines for establishing the appropriate therapeutic strategies to counteract obesity-associated vascular calcification.

[The Breast Cancer Cohort Study in Chinese Women: the methodology of population-based cohort and baseline characteristics]

Objective: Breast cancer has been the first cancer among women with the incidence increasing gradually. In September 2016, the Breast Cancer Cohort Study in Chinese Women (BCCS-CW) was initiated, aiming to establish a standardized and sharable breast cancer-specific cohort by integrating the existing cohort resource and improving the quality of follow-up. The BCCS-CW may provide a research basis and platform for the precision prevention and treatment of breast cancer in etiology identification, prevention, early diagnosis, treatment, and prognosis prediction. Methods: We conducted a population-based perspective cohort by questionnaire interview, anthropometry, biological specimens, breast ultrasound and mammography. The cohort was followed by using regional health surveillance and ad hoc survey. Results: Finally, BCCS-CW included 112 118 women, in which 55 419 women completed the standardized investigation and blood specimens were collected from 54 304 women. The mean age of participants was 51.7 years old, 62.7% were overweight or obese, and 48.9% were menopausal. Conclusion: The BCCS-CW will provide population-based cohort resource and research platform for the precise prevention and treatment of breast cancer in Chinese women.

[Epidemiological study of occupational diseases in Shenzhen City, China in 2006~2017]

Objective: To study the epidemiological characteristics of occupational diseases in Shenzhen City, China in 2006-2017, and to provide a scientific basis for prevention and control of occupational diseases. Methods: Cases of occupational diseases in 2006-2017 were collected from the Information System of Occupational Diseases and Occupational Health. A statistical analysis was performed to identify the characteristics of the disease distribution in terms of spectrum of disease, year, area, industry, type of economy and enterprise scale. Results: A total of 1673 cases of occupational disease (64 types, 8 classes) were diagnosed and reported in 2006-2017, chemical poisoning (31.50%) , ear, nose and throat diseases (28.21%) , and pneumoconiosis and other respiratory diseases (21.34%) were the most three commonest occupational diseases. The constituent of ratio of ear, nose and throat diseases and occupational diseases caused by physical factors increased in turn, the constituent of chemical poisoning, pneumoconiosis and other respiratory diseases, and skin disease reduced in turn, which all showed the difference was statistically significant (P<0.01) . Occupational diseases were often seen in districts of Baoan, Longgang, Longhua and Pingshan, as well as in private economy and small enterprise, mainly occurred in manufacturing industry. Conclusion: The incidence of occupational diseases increased steadily in 2006-2017, and we need to strengthen common occupational diseases, especially occupational noise-induced hearing loss, pay attention to districts of Baoan, Longgang, Longhua and Pingshan, as well as private economy and small enterprise.

[A Meta-analysis on the association between sleep duration and metabolic syndrome in adults]

Objective: To quantitatively evaluate the relationship between sleep duration and metabolic syndrome in adults in order to set up programs on prevention and treatment of metabolic syndrome in this population. Methods: Relevant studies were identified by systematically searching databases before October 2019. All statistical analyses were under the use of Stata 11.0. Results: A total of 656 319 participants including 150 638 cases with metabolic syndrome were involved in thes 38 articles. A U-shaped relationship between sleep duration and metabolic syndrome was noticed. For short and long sleep duration, the OR=1.11 (95%CI: 1.07-1.16) and 1.10 (95%CI: 1.03-1.18), respectively. Subgroup analyses on cross-sectional studies revealed that factors as men, aged under 60 years, being Asians or Caucasians would increase the risk of metabolic syndrome by 6%, 14%, 9%, and 24%, respectively for those with short sleep duration. Factors as aged 60 years and above, being black and with long sleep duration, would increase the risks of metabolic syndrome by 13% and 19%, respectively in women. In subgroup analyses on cohort studies, positive correlation between short sleep duration and metabolic syndrome was observed in both Asian (RR=1.10, 95%CI: 1.07-1.13) and in Caucasians (RR=1.56, 95%CI: 1.08-2.26) populations. Conclusions: Results of this study revealed an association between metabolic syndrome and the duration of sleep. We understand that sleep is a behavior that can be changed step by step, through adequate intervention programs, to reduce the risk of metabolic syndrome which has become an important public health issue.

The role of miR-145 in promoting the fibrosis of pulmonary fibroblasts

The effects of miR-145 (microRNA 145) on M. pneumoniae (MP)-infected MRC-5 (Medical Research Council cell strain 5) cell TGF-β/Smad (transforming growth factor beta/Smad) fibrosis pathway were explored through constructing MP-infected MRC-5 cell models. In addition, the qPCR (quantitative real-time polymerase chain reaction) and Western blot were applied to detect the mRNA and protein expressions of miR-145, TGF-β1 (transforming growth factor beta 1), Smad3, Smad4, MMP2 (matrix metalloproteinase 2), FN1 (fibronectin 1), ELN (elastin) and COLI α1 (collagen type I alpha 1) signaling molecules in TGF-β/Smad fibrosis pathway. The results showed that the expression of miR-145 in MRC-5 cells was significantly increased after MP infection. In addition, miR-145 inhibited the fibrosis promoting TGF-β/Smad pathway by targeting Smad3, a key factor in the TGF-β/Smad pathway. It can be concluded that, in the process of MP infection, the expression of miR-145 is stimulated to negatively regulate the fibrosis-promoting pathway of TGF-β/Smad.

[Prevalence, awareness, treatment and control of hypertension in elderly residents in Hebei province]

Objective: To understand the prevalence, awareness, treatment and control of hypertension in elderly residents in Hebei province. Methods: Elderly residents aged ≥60 were selected though multistage clustering sampling during August to December, 2015. Design based methods were adopted to analyze the prevalence, awareness, treatment and control of hypertension in local residents of Hebei. Results: A total of 2 501 elderly adults were included in the study. The overall prevalence rate of hypertension was 63.7% (58.3% in males, 69.0% in females), the awareness rate of hypertension was 42.4% (35.7% in males, 48.0% in females), the treatment rate was 38.2% (32.0% in males, 43.3% in females), and the control rate was 9.0% (8.1% in males, 9.7% in females). The results of multivariate analysis indicated that age, sex, degree of education, BMI and central obesity were the factors influencing the prevalence, awareness, treatment and control of hypertension in elderly population in Hebei. Conclusions: The prevalence of hypertension was high, but the rates of awareness, treatment and control of hypertension were low in elderly residents in Hebei. The influences of overweight, obesity and central obesity on hypertension were significant in the elderly. It is necessary to standard the management of hypertension and reduce the risk factors for hypertension in elderly population to improve the control of hypertension.

Combined 3D-tomography and 3D-power Doppler for vascular imaging of the liver

This study aimed to investigate the role of three-dimensional color tomographic ultrasound (3D-CTU) and three-dimensional color power Doppler (3D-CPD) imaging in diagnostics of liver lesions. Based on 3D-anatomical sectional structures of the liver, we used 3D-CTU and 3D-CPD techniques to reconstitute 3D-images of lobes, segments, and intra-segmental blood vessels, and lesions of the liver. With the use of this technique, we were able to generate 3D vascular patterns of liver lobes, segments and tumor lesions, and their spatial relationship. The observed vascular patterns of intra- and peri-tumor (including surrounding lobes and segments) and the spatial relation can be used for accurate positioning of liver lesions.

[Prevalence of diabetes in adults in Hebei province]

Objective: To understand the prevalence of diabetes in adults in Hebei province. Methods: The survey was conducted among the local residents aged ≥18 years, who were selected through multi stage cluster sampling from September 2013 to April 2014. Design-based methods were used to analyze the prevalence in the last 12 months. Results: A total of 7 678 adults were included in the study. The overall prevalence of diabetes in Hebei was 12.9% (13.1% in men and 12.8% in women), there was no sex specific difference in diabetes prevalence (P=0.09). The prevalence was higher in urban residents (16.2%) than that in rural residents (12.1%), the difference was significant (P<0.01). The prevalence of diabetes increased with age (P<0.01). The prevalence of impaired fasting glucose was 5.1%, the difference was significant between men and women and between rural area and urban area (P<0.01). The prevalence of impaired glucose tolerance was 10.4%. The difference of prevalence of impaired glucose tolerance in men and women and between rural area and urban area was not significant. The rates of awareness, treatment and control of diabetes were 50.7%, 46.3% and 37.5%, respectively. Women had higher awareness rate and treatment rate of diabetes than men, the difference was significant (P<0.01). Conclusions: The prevalence of diabetes was high in adults in Hebei province, the difference in diabetes prevalence between urban area and rural area was significant. The prevalence of impaired fasting glucose and impaired glucose tolerance were high, but the rates of awareness, treatment and control of diabetes were low.

Comprehensive genomic profiling of anal squamous cell carcinoma reveals distinct genomically defined classes

BACKGROUND

Squamous cell cancers of the anal canal (ASCC) are increasing in frequency and lack effective therapies for advanced disease. Although an association with human papillomavirus (HPV) has been established, little is known about the molecular characterization of ASCC. A comprehensive genomic analysis of ASCC was undertaken to identify novel genomic alterations (GAs) that will inform therapeutic choices for patients with advanced disease.

PATIENTS AND METHODS

Hybrid-capture-based next-generation sequencing of exons from 236 cancer-related genes and intronic regions from 19 genes commonly rearranged in cancer was performed on 70 patients with ASCC. HPV status was assessed by aligning tumor sequencing reads to HPV viral genomes. GAs were identified using an established algorithm and correlated with HPV status.

RESULTS

Sixty-one samples (87%) were HPV-positive. A mean of 3.5 GAs per sample was identified. Recurrent alterations in phosphoinositol-3-kinase pathway (PI3K/AKT/mTOR) genes including amplifications and homozygous deletions were present in 63% of cases. Clinically relevant GAs in genes involved in DNA repair, chromatin remodeling, or receptor tyrosine kinase signaling were observed in 30% of cases. Loss-of-function mutations in TP53 and CDKN2A were significantly enhanced in HPV-negative cases (P < 0.0001).

CONCLUSIONS

This is the first comprehensive genomic analysis of ASCC, and the results suggest new therapeutic approaches. Differing genomic profiles between HPV-associated and HPV-negative ASCC warrants further investigation and may require novel therapeutic and preventive strategies.

Association between the epithelial cadherin -160C/A gene polymorphism and diffuse gastric cancer risk: a meta-analysis

Several previous studies have investigated whether the -160C/A epithelial cadherin promoter polymorphism confers an increased risk of diffuse gastric cancer (DGC), but conflicting results have been reported. To explore further the association of this polymorphism with DGC susceptibility, we performed an extensive search of relevant studies and conducted a meta-analysis to obtain a more precise estimate. We conducted a systematic literature search using the databases EMBASE, PubMed, and Web of Knowledge for reports published before August 2012 that met certain criteria. Information was carefully and independently extracted from all eligible publications by 2 of the authors. Twelve distinct data sets from 10 case-control studies were analyzed. They included 1115 cases of DGC and 2965 controls. Although none of the genotypes was associated with DGC risk, a slight trend of increased risk was found among A allele carriers [odds ratio (OR) = 1.237, 95% confidence interval (95%CI), 0.940-1.627], CA heterozygotes (OR = 1.229, 95%CI = 0.938-1.610), and AA homozygotes (OR = 1.146, 95%CI = 0.684-1.918). However, when the cases were stratified by ethnicity, a diverging trend occurred in AA homozygotes between the Asian group (OR = 0.710, 95%CI = 0.328-1.536) and its Caucasian counterpart (OR = 1.434, 95%CI = 0.657-3.131). Taken together, the summarized analyses of these case-control studies demonstrated that the -160A of the epithelial cadherin gene exhibited no significant association with susceptibility for DGC; however, the results suggested that it is a potential genetic risk factor in both Asians and Caucasians. Additional large-scale, well-designed studies are necessary to confirm whether AA homozygosity is a protective factor in Asians.

Activation of liver X receptors inhibits pancreatic islet beta cell proliferation through cell cycle arrest

AIMS/HYPOTHESIS

Liver X receptors (LXRs) are important transcriptional regulators of lipid homeostasis and proliferation in several cell types. However, the roles of LXRs in pancreatic beta cells have not been fully established. The aim of this study was to investigate the effects of LXRs on pancreatic beta cell proliferation.

METHODS

Gene expression was analysed using real-time RT-PCR. Transient transfection and reporter gene assays were used to determine the transcriptional activity of LXRs in pancreatic beta cells. Cell viability and proliferation were analysed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), DNA fluorometric, BrdU labelling and [(3)H]thymidine incorporation assays. Cell cycle distribution was investigated by flow cytometry analysis. Adenovirus-based RNA interference was used to knockdown LXRalpha, LXRbeta and p27 in MIN6 cells and mouse islets.

RESULTS

We found that both Lxralpha (also known as Nr1h3) and Lxrbeta (also known as Nr1h2) were expressed and transactivated the LXR response element in HIT-T15 and MIN6 cells. Activation of LXRs dose-dependently inhibited pancreatic beta cell viability and proliferation. This was accompanied by beta cell cycle arrest at the G1 phase. Furthermore, LXR activation increased levels of the p27 protein by inhibiting its degradation. Knockdown of p27 reversed these effects of LXR activation on growth inhibition and cell cycle arrest.

CONCLUSIONS/INTERPRETATION

Our observations indicate that LXR activation inhibits pancreatic beta cell proliferation through cell cycle arrest. A well-known regulator of pancreatic beta cell cycle progression, p27, is upregulated and mediates the effects of LXRs on growth inhibition in beta cells. These observations suggest the involvement of aberrant activation of LXR in beta cell mass inadequacy, which is an important step in the development of type 2 diabetes.

Prostaglandin E2 regulates Foxo activity via the Akt pathway: implications for pancreatic islet beta cell dysfunction

AIMS/HYPOTHESIS

Prostaglandin E(2) (PGE(2)) is a well-recognised inhibitor of glucose-stimulated insulin secretion (GSIS). The aim of this study was to investigate the signalling pathway of PGE(2) in beta cell function regulation in HIT-T15 cells and isolated rat islets.

MATERIALS AND METHODS

mRNA levels of the prostaglandin E receptor 3 (Ptger3) were measured by real-time PCR. Western blot analysis was used to detect changes in the levels of PTGER3, phosphorylated and total Akt, phosphorylated and total forkhead box 'Other' (Foxo). Transient transfection and reporter assays were used to measure Foxo transcriptional activity. The biological significance of PGE(2) in beta cell function was analysed using MTT, flow cytometry and GSIS assays.

RESULTS

We found that treating HIT-T15 cells with exogenous PGE(2) stimulated Ptger3 gene expression specifically, and diminished cAMP generation. These were accompanied by the downregulation of Akt and Foxo phosphorylation in HIT-T15 cells and isolated rat islets. Moreover, PGE(2) upregulated basal and partially reversed constitutively active Akt-inactivated Foxo transcriptional activity. Furthermore, GSIS was impaired in PGE(2)-treated HIT-T15 cells and isolated islets. However, the dosage used in the above experiments did not affect beta cell viability and apoptosis. In addition, insulin-like growth factor 1 (IGF-1) pretreatment reversed the effects of PGE(2), and wortmannin treatment abolished the preventive effects of IGF-1.

CONCLUSIONS/INTERPRETATION

Our observations strongly suggest that PGE(2) can induce pancreatic beta cell dysfunction through the induction of Ptger3 gene expression and inhibition of Akt/Foxo phosphorylation without impacting beta cell viability. These results shed light on the mechanisms of PGE(2) actions in pancreatic beta cell dysfunction.

Physicochemical characterization of cellulose from perennial ryegrass leaves (Lolium perenne)

In this study, we investigated the physicochemical properties of the cellulosic preparations obtained from both untreated perennial ryegrass leaves and de-juiced leaves. It was found that treatment at 22 degrees C with 18% NaOH and 18% KOH for 2h, and 10% NaOH and 10% KOH for 16 h yielded 28.2%, 28.8%, 22.7%, 23.4%, respectively, of 'cellulose' residue from untreated ryegrass leaves and 35.7%, 36.8%, 32.8% and 34.6%, respectively, from the de-juiced leaves. For each cellulosic fraction, the glucose content was 71.6%, 69.6%, 67.8%, 66.7%, 69.7%, 68.6%, 63.9% and 61.7%, respectively. The structure of the cellulose samples was examined using FTIR and CP/MAS (13)C NMR spectroscopy and X-ray diffraction. The cellulosic preparations were free of bound lignin except for noticeable amounts of residual hemicelluloses (28.4-38.3%), and had intrinsic viscosities between 275.1 and 361.0 mL/g, along with molecular weights from 144,130 to 194,930 g/mol. This study found that the cellulose samples isolated from both de-juiced ryegrass leaves and the untreated leaves had a much lower percent crystallinity (33.0-38.6%) than that from wood-based fibres (60-70%) and had much shorter fibres (0.35-0.49 mm) than those of either cereal straws, bagasse or wood. In addition, a partial disruption of the hydrogen bonds and microfibrils may occur during the de-juicing process by mechanical activity, which results in a decreased cellulose crystallinity and fibre length. These findings are significant in relation to hydrolysing ryegrass cellulose for bio-ethanol production.

Fractional and structural characterization of hemicelluloses from perennial ryegrass (Lolium perenne) and cocksfoot grass (Dactylis glomerata)

Sequential three-stage treatments with 80% EtOH containing 0.2% NaOH, 2.5% H2O2-0.2% EDTA containing 1.5% NaOH and 2.5% H2O2-0.2% TAED containing 1.0% NaOH at 75 degrees C for 3h released 8.0% and 10.4%, 79.1% and 77.0% and 12.9% and 12.5% of the original hemicelluloses from perennial grass and cocksfoot grass, respectively. It was found that the four alkaline peroxide-soluble hemicellulosic fractions contained higher amounts of xylose (33.4-38.2%), uronic acids (9.3-15.3%) and rhamnose (3.0-3.9%), but were lower in glucose (25.1-28.3%), galactose (13.3-15.3%) and mannose (0.4-1.5%) than those of the two alkaline EtOH-soluble hemicellulosic fractions in which glucose (32.9-36.0%), xylose (20.1-22.6%), arabinose (14.1-21.4%), galactose (16.6-19.9%), mannose (4.1-9.9%) and uronic acids (3.4-7.4%) were the major sugar components. 13C NMR spectroscopy confirmed that all the six hemicellulosic fractions were composed of galactoarabinoxylans, 4-O-methylglucuronoarabinoxylans and beta-glucan. In addition, the studies showed that the four alkaline peroxide-soluble hemicellulosic fractions were more linear and acidic and had larger molecular weights (Mw, 28,400-38,650 g mol(-1)) than those of the two alkaline EtOH-soluble hemicellulosic fractions (Mw, 16,460-17,420 g mol(-1)).

Comparative study of alkali- and acidic organic solvent-soluble hemicellulosic polysaccharides from sugarcane bagasse

Two-stage treatments of sugarcane bagasse with mild alkali and acidic 1,4-dioxane were performed. Pretreatment with 1M NaOH aqueous solution at 20, 25, 30, 35, and 40 degrees C for 18 h released 55.5%, 57.3%, 59.1%, 60.9%, and 62.1% of the original hemicelluloses, respectively. Post-treatment of the corresponding alkali-treated residue with 1,4-dioxane-2M HCl (9:1, v/v) at 87 degrees C for 2h, respectively, degraded 11.6%, 11.9%, 11.4%, 10.9%, and 10.6% of hemicelluloses (% dry starting material). It was found that the five alkali-soluble hemicellulosic preparations contained a much higher amounts of xylose (78.0-82.2%) and slightly higher uronic acids (4.8-5.8%), mainly 4-O-methyl-alpha-d-glucopyranosyluronic acid, but were lower in arabinose (9.3-11.7%) and glucose (2.2-4.1%) than those of the corresponding five acidic dioxane-degraded hemicellulosic fractions in which xylose (44.9-46.8%), arabinose (35.9-38.1%), and glucose (13.0-13.7%) were the major sugar constituents. The studies revealed that the five alkali-soluble hemicellulosic preparations were more linear and acidic, and had a large molecular weight (35,200-37,430 g mol(-1)) than those of the hemicellulosic fractions (12,080-13,320 g mol(-1)) degraded during the acidic dioxane post-treatment. This demonstrated that the post-treatment with acidic dioxane under the condition used resulted in substantial degradation of the hemicellulosic polymers. The 10 hemicellulosic samples were further characterized by FT-IR and 1H and 13C NMR spectroscopy, GPC and thermal analysis, and the results are reported.

Acetylation of sugarcane bagasse using NBS as a catalyst under mild reaction conditions for the production of oil sorption-active materials

Sugarcane bagasse was esterified with acetic anhydride using N-bromosuccinimide as a catalyst under mild conditions in a solvent free system. The extent of acetylation was measured by weight percent gain, which varied from 2.1% to 24.7% by changing the reaction temperature (25-130 degrees C) and duration (0.5-6.0 h). N-Bromosuccinimide was found to be a novel and highly effective catalyst for acetylation of hydroxyl groups in bagasse. At a concentration of 1% of the catalyst in acetic anhydride, a weight percent gain of 24.7% was achieved at 120 degrees C for 1 h, compared with 5.1% for the un-catalyst reaction under the same reaction condition. FT-IR and CP-MAS 13C-NMR studies produced evidence for acetylation. The thermal stability of the products decreased slightly upon chemical modification, but no significant decrease in thermal stability was observed for WPG > or = 24.7%. More importantly, the acetylation significantly increased hydrophobic properties of the bagasse. The oil sorption capacity of the acetylated bagasse obtained at 80 degrees C for 6 h, was 1.9 times higher than the commercial synthetic oil sorbents such as polypropylene fibres. Therefore, these oil sorption-active materials can be used to substitute non-biodegradable materials in oil spill cleanup.

[Research progress of methods of heart rate variability analysis]

One of the hotspots in the analysis of ECG is heart rate variability (HRV). In the present, the method mostly used for the analysis of HRV signal is linear analysis, and nonlinear analysis seldom used. Research progress of several methods of HRV analysis is presented. Principles and characteristics of using nonlinear analysis for the study of HRV are analyzed in detail. Fractal dimension, complexity and approximate entropy are discussed.

Preparation of recombinant human GDNF by baculovirus expression system and analysis of its biological activities

Recombinant human glial cell line-derived neurotrophic factor (GDNF) has been expressed at high levels and produced in large quantities in baculovirus-infected Trichoplusia ni cells (Tn-5B1-4). The glycosylated protein was purified using immunoaffinity chromatography and gel filtration. Pure, recombinant human GDNF promoted the survival and morphological differentiation of embryonic dopaminergic neurons and enhanced axonal regeneration after sciatic nerve transection. Because recombinant bioactive human GDNF can be obtained in large quantities, and purified to near homogeneity, they are suitable for evaluation in animal models.

Study on binding of REEs with water-soluble polysaccharides in fern

The binding of rare earth elements (REEs) with water-soluble polysaccharides of nondeproteinization and deproteinization in the leaves of the fern Dicranopteris dichotoma was studied by molecular activation analysis (MAA). Two cold-water-soluble polysaccharides (extracted by 75% ethanol and 90% ethanol, respectively) and one hot-water-soluble polysaccharide (extracted by 90% ethanol) were separated using biochemical separation techniques. The eight rare earth elements (La, Ce, Nd, Sm, Eu, Tb, Yb, and Lu) in these polysaccharides were determined by instrumental neutron activation analysis. Our new results showed that the REEs were bound firmly with the water-soluble polysaccharides in the plant, regardless of whether nondeproteinization or deproteinization was used. The molecular-weight (MW) measurement demonstrated that REEs were mainly bound with low-MW (10,000-20,000) polysaccharides.

Phase I trial of orally administered pentosan polysulfate in patients with advanced cancer

Tumor angiogenesis is critically important to tumor growth and metastasis. We have shown that pentosan polysulfate (PPS) is an effective inhibitor of heparin-binding growth factors in vitro and can effectively inhibit the establishment and growth of tumors in nude mice. Following completion of our Phase I trial of s.c. administered PPS, we performed a Phase I trial of p.o. administered PPS in patients with advanced cancer to determine the maximum tolerated dose (MTD) and toxicity profile and to search for any evidence for biological activity in vivo. Patients diagnosed with advanced, incurable malignancies who met standard Phase I criteria and who did not have a history of bleeding complications were enrolled, in cohorts of three, to receive PPS p.o. t.i.d., at planned doses of 180, 270, 400, 600, and 800 mg/m2. Patients were monitored at least every 2 weeks with physical exams and weekly with hematological, chemistry, stool hemoccult, and coagulation blood studies, and serum and urine samples for PPS and basic fibroblastic growth factor (bFGF) levels were also taken. The PPS dose was escalated in an attempt to reach the MTD. Eight additional patients were enrolled at the highest dose to further characterize the toxicity profile and biological in vivo effects of PPS. A total of 21 patients were enrolled in the three cohorts of doses 180 (n = 4), 270 (n = 3), and 400 (n = 14) mg/m2. The most severe toxicities seen were grade 3 proctitis and grade 4 diarrhea; however, 20 of the 21 patients had evidence of grade 1 or 2 gastrointestinal (GI) bleeding. These toxicities became evident at a much earlier time point as the dose was increased, but their severities were similar at all dose levels. There were no objective responses, although three patients had prolonged stabilization of previously progressing disease. Pharmacokinetic analysis suggested marked accumulation of PPS upon chronic administration. Serum and urine bFGF levels failed to show a consistent, interpretable pattern; however the data suggested an inverse relationship between PPS and bFGF levels in vivo. A MTD could not be determined using the daily t.i.d. dosing schedule due to the development of grade 3/4 GI toxicity (proctitis) at all dose levels studied. PPS, administered p.o. at doses of 400 mg/m2 t.i.d., did not cause significant systemic toxicity, but most patients developed moderate-to-severe GI toxicity within 1-2 months. The cause of the GI toxicity was unclear, but it was readily reversible upon cessation of the agent. The suggestion of an inverse relationship between PPS and bFGF supports further study of PPS as an antiangiogenic agent. The tested doses and schedule cannot be recommended for further study. Subsequent murine experiments showed PPS to be more effective as an anticancer agent when it is given intermittently. We propose a study of PPS given on a weekly schedule in further clinical trials.

Explaining variable absorption of a hypolipidemic agent (CGP 43371) in healthy subjects by gamma scintigraphy and pharmacokinetics

The gastrointestinal absorption of a hypolipidemic agent (CGP 43371) was investigated using an external scintigraphy technique in six healthy men. After an overnight fast, subjects received a single 800-mg oral dose of CGP 43371 (4 capsules of 200 mg each) and one capsule of radioactive samarium-153 oxide (100-130 microCi) as a nonabsorbable marker of gastrointestinal transit and fecal recovery for CGP 43371. In vivo gastrointestinal transit of samarium-153 was monitored via gamma scintigraphy for 48 hours after administration to coincide with blood sampling. Samarium-153 content in whole fecal samples was determined by external gamma scintigraphy, and CGP 43371 content in both fecal and plasma samples was determined using high-performance liquid chromatography (HPLC). The results of fecal analysis indicated that transit of the two compounds in the gastrointestinal tract were similar, and bioavailability of CGP 43371 was calculated to be 9% based on the difference between the cumulative amounts of the nonabsorbable radioactive marker and CGP 43371 found in the feces. The onset of drug absorption occurred 4 hours after administration when radioactive samarium-153 was in the distal small bowel, and peak plasma drug level occurred 6 hours after administration, which corresponded with the arrival of samarium-153 in the terminal ileum and ileal/cecal junction. This observation supported the concept that primary absorption of this compound was in the distal to terminal portion of the ileum. Although the onset of drug absorption was delayed, it was curious that the rate of gastric emptying also affected the extent of absorption. A positive correlation (r = 0.91) between area under the drug curve (AUC) and area under the transit curve (AUTC) of the gastric emptying showed that longer gastric residence improved oral absorption of CGP 43371.

Comparative pharmacokinetics and bioavailability of nitroglycerin and its metabolites from Transderm-Nitro, Nitrodisc, and Nitro-Dur II systems using a stable-isotope technique

The pharmacokinetics and bioavailability of nitroglycerin (GTN) and its metabolites, 1,2-glyceryl dinitrate (1,2-GDN) and 1,3-glyceryl dinitrate (1,3-GDN), were compared after a single 14-hour application of Transderm-Nitro (Ciba-Geigy, Summit, NJ), Nitrodisc (GD Searle, Chicago, IL), and Nitro-Dur II (Key Pharmaceuticals, Kenilworth, NJ) systems to 18 healthy male subjects on 3 separate occasions. A 14-hour intravenous infusion of 15N-labeled GTN was given simultaneously to correct for changes in systemic clearance during the application of each system. Plasma concentrations of 15N-labeled GTN, unlabeled GTN, and their corresponding dinitrate metabolites were measured using a gas chromatography/mass spectrometry method. Results showed that the plasma concentration profiles of nitroglycerin and its metabolites for the three systems were similar during and after system removal. Mean (SD) total amounts (AUCp x CLiv) of GTN transdermally available after adjustment for 15N-labeled GTN clearance were 5.3 (2.1), 5.3 (2.0), and 5.4 (2.6) mg for Transderm-Nitro, Nitrodisc, and Nitro-Dur II, respectively. Mean (SD) AUC values for 1,2-GDN were 44.6 (15.8), 44.3 (16.1), and 42.8 (19.3) ng.h/mL for the 3 systems. Corresponding AUC values for 1,3-GDN were 9.3 (2.9), 9.7 (2.9), and 8.7 (3.0) ng.h/mL. Statistical analysis of the log-transformed data based on 90% conventional confidence interval showed that all 3 systems delivered equivalent amounts of nitroglycerin into the systemic circulation. The AUC ratios for 1,3-GDN to GTN, but not 1,2-GDN to GTN, were statistically different for the intravenous and transdermal routes during all 3 system applications, indicating that the formation and metabolism of 1,3-GDN was dependent on route of administration.

Pharmacokinetic interaction study between benazepril and amlodipine in healthy subjects

Pharmacokinetic interaction between benazepril (ACE inhibitor) and amlodipine (calcium channel blocker) was studied in 12 healthy subjects. Single doses of benazepril hydrochloride (10-mg tablet) and amlodipine besylate (tablet equivalent to 5 mg amlodipine) were administered alone or in combination according to a three-way, Latin-Square, randomized cross-over design. Serial blood samples were collected following each administration for the determination of benazepril and its active metabolite benazeprilat and amlodipine. The mean values of AUC (0-4 h), Cmax and Tmax for benazepril given as combination versus given alone were 161 vs 140 ng.h.ml-1, 168 vs 149 ng.ml-1, and 0.5 vs 0.6 h. The mean values of AUC (0-24 h), Cmax and Tmax for benazeprilat after benazepril given as combination versus given alone were 1470 vs 1410 ng.h.ml-1, 292 vs 257 ng.ml-1, and 1.7 vs 1.5 h. The mean values of AUC (0-144 h), Cmax and Tmax for amlodipine given as combination versus given alone were 118 vs 114 ng.h.ml-1, 2.5 vs 2.3 ng.ml-1, and 8.3 vs 9.0 h. The differences in these pharmacokinetic parameters between the combination and monotherapy treatments were not statistically significant based on ANOVA. The results of this study indicate that no pharmacokinetic interaction existed between the two drugs.

Effect of food on the relative bioavailability of a hypolipidemic agent (CGP 43371) in healthy subjects

The relative bioavailability of a capsule formulation and the effects of food on the pharmacokinetics of a hypolipidemic agent (CGP 43371) in 12 healthy subjects were examined. Each subject randomly received a single dose of 800 mg of CGP 43371, either as a dispersion formulation under fasting conditions or as a capsule formulation under fasting and fed conditions in a three-way crossover design with a washout period of 2 weeks between each treatment. Serial blood samples were collected at frequent intervals up to 96 h after each treatment. The concentrations of CGP 43371 in plasma were determined by a normal-phase HPLC method. Similar mean pharmacokinetic data (peak plasma drug concentration, 0.16 versus 0.18 micrograms/mL; area under the plasma drug concentration-time curve from time zero to infinity, 4.56 versus 4.22 micrograms.h/mL; time to the peak plasma drug concentration, 10.3 versus 10.2 h; lag time, 3.7 versus 3.8 h; and terminal elimination half-life, 17.8 versus 15.0 h) for the dispersion and capsule formulations under fasting conditions indicated that both formulations were bioequivalent with respect to the rate and extent of absorption. In contrast, the mean peak plasma drug concentration (2.01 micrograms/mL) and area under the curve from time zero to infinity (57.35 micrograms.h/mL) for the capsule formulation with food were enhanced approximately 11- and 14-fold, respectively, when compared with that without food. The corresponding mean lag time (2.1 h) was decreased approximately 50%. These differences in pharmacokinetic parameters were statistically significant, on the basis of an analysis of variance.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of food on the relative bioavailability of fadrozole hydrochloride

The effect of food on the pharmacokinetic disposition of fadrozole hydrochloride was evaluated in nine healthy male and female volunteers. Single 12 mg doses of fadrozole were orally administered to subjects immediately following a standardized meal or after fasting for 12 h, in a randomized crossover design. No statistically significant treatment differences were detected for the pharmacokinetic parameters AUC and half-life. Cmax was significantly reduced by 15% for the fed treatment relative to the fasted treatment, and tmax was delayed by 39%. These findings indicate that the concomitant ingestion of food with fadrozole delays the gastric emptying and/or absorption of fadrozole, but has no effect on the extent of absorption.

Pharmacokinetic disposition of multiple-dose transdermal nicotine in healthy adult smokers

The pharmacokinetics and cardiovascular effects of nicotine and its major metabolite, cotinine, were characterized during repeated once-daily application for 5 days of a 30-cm2 nicotine transdermal system, Nicotine TTS (Habitrol), to nine healthy, black, adult, male smokers. Subjects abstained from smoking throughout the study. Pharmacokinetic analysis indicated that nicotine was delivered from Nicotine TTS for the 24-hr application period averaging 0.76 mg/cm2/24 hr, and at a relatively constant rate compared to other modes of drug administration. The transdermal clearance of nicotine, 1351 ml/min, coincided with reported values following intravenous nicotine administration; however, the terminal-phase half-life, 5.0 hr, did not. An analysis of the components of variance contributing to the variability in nicotine delivery from repetitive application of Nicotine TTS indicated that the in vivo transdermal permeation of nicotine is rate limited by both the device and the intrinsic skin conductivity. Clinical cardiovascular side effects were negligible as an apparent result of subclinical vasopressive nicotine concentrations, although drug activity with regard to other effects was manifested.

Changes of nerve excitability and urinary deltamethrin in sprayers

The nerve excitability of median nerve as well as the urinary deltamethrin and its metabolite dibromovinyl-dimethyl-cyclopropane carboxylic acid (Br2A) were detected in 24 deltamethrin sprayers in an assessment of the exposure and effect of deltamethrin. Twenty-nine male, unexposed referents of the same age range were also selected. The urinary deltamethrin and its metabolite Br2A were detectable by GC and HPLC in the sprayers after exposure. The nerve excitability detected with an electromyograph and pairs of stimuli at variable intervals showed that there was a prolongation of supernormal period in median nerve of the exposed group after a 3-d spraying compared with that before spraying which became more significant 2 d after cessation of exposure. In the mean time, no change of supernormal period in the median nerve of reference group was found at the 3-d interval. Nearly half of the sprayers had a supernormal period prolonged by more than 4 ms after spraying, whereas nearly none of the reference group showed similar changes after repeated examinations. Although there was neither correlation between the nerve excitability changes and the urinary deltamethrin or Br2A excretion, nor was a case of acute deltamethrin poisoning diagnosed, the non invasive technique used for nerve excitability detection in this study seems to be valuable in studying deltamethrin toxicity on human.

Levels of exposure and biological monitoring of pyrethroids in spraymen

To assess the exposure response relation of pyrethroids in spraymen, 50 adult male cotton growers were selected and divided into three groups, one group to spray pyrethroids for one day, two groups to spray for three days. Deltamethrin, fenvalerate, and a deltamethrin methamidophos mixture were sprayed by appropriate subgroups for five hours a day. Exposure levels were evaluated by measuring the air concentration, dermal exposure concentration, and urinary content of pyrethroids by gas chromatography. Air concentrations of deltamethrin at the breathing zone were 0.01-0.89 microgram/m3 in the deltamethrin exposed group. For fenvalerate, air concentrations were 0.06-1.98 micrograms/m3. Dermal exposure, particularly on the legs, feet, and hands was appreciable and indicated that this was the main route of absorption. In those spraying for one day, urinary deltamethrin was not detectable by 12 hours after the beginning of exposure whereas fenvalerate was still detectable up to 24 hours after first exposure. Both pyrethroids could be detected two days after the end of three day spraying. Health effects were investigated by interview and physical examination. Twenty nine spraymen complained of abnormal facial sensations that developed mostly two to three hours from the start of pyrethroid spraying and that disappeared by 24 hours after exposure ceased. Some had dizziness, headache, and nausea, but no subject was diagnosed as having acute pyrethroid poisoning. The symptoms showed no significant correlation with urinary pyrethroid excretion. Blood cholinesterase activity of spraymen using the pyrethroid methamidophos mixture did not change.

An epidemiological study on occupational acute pyrethroid poisoning in cotton farmers

A cross sectional survey on the prevalence of acute pyrethroid poisoning in cotton farmers was conducted in 1987 and 1988. A total of 3113 pyrethroid spraymen (2230 men (71.6%) and 883 women (28.4%] were interviewed after spraying and followed up for 72 hours. Adverse effects of pyrethroid exposure were found in 834 of them (26.8%) manifested as abnormal facial sensations, dizziness, headache, fatigue, nausea, or loss of appetite. Only 10 subjects, who developed significant systemic symptoms and had signs of listlessness or muscular fasciculation, were diagnosed as having mild occupational acute pyrethroid poisoning with a prevalence of 0.31% in subjects exposed to pure pyrethroids and 0.38% in subjects exposed to pyrethroid organophosphate mixtures. Measurements of pyrethroid concentrations in the air of the breathing zone, in skin pads, and in urine samples showed that dermal contamination is the main route of exposure to pyrethroids in cotton growers. Preventive measures are recommended.

Fructose 1-6 diphosphate prevents intestinal ischemic reperfusion injury and death in rats

This study of ischemic and postischemic reperfusion intestinal injury in rats evaluates the potential therapeutic value of fructose 1-6 diphosphate on the basis of its ability to enhance anaerobic carbohydrate metabolism during ischemia and to prevent additional tissue injury after reestablishing blood flow by inhibiting the neutrophils to produce oxygen free radicals. In pursuit of this goal, 28 rats were randomized into 4 groups: pretreated with fructose 1-6 diphosphate (n = 7); pretreated with glucose (n = 7); post-reperfusion treated with fructose 1-6 diphosphate (n = 7); and post-reperfusion treated with saline (n = 7). Five additional rats were sham operated. Following 30 min occlusion of the superior mesenteric artery, all rats received their respective treatments for 5 days. Post-reperfusion arterial pressure was significantly lower in the control rats (p less than 0.001) as well as when compared with the fructose 1-6 diphosphate groups (p less than 0.001). Significant increase in white blood cell counts occurred in the controls (p less than 0.001), whereas in the fructose 1-6 diphosphate groups white blood cell counts were no different from preischemic values. All control rats that died in less than 5 days had transmural intestinal necrosis, whereas in 3 of the controls that survived 5 days, partial intestinal necrosis was noted. Only one fructose 1-6 diphosphate-treated rat had partial intestinal necrosis. The overall 5-day survival was 100% for sham-operated rats, 93% for fructose 1-6 diphosphate-treated rats, and 21% for controls (fructose 1-6 diphosphate vs. controls, p less than 0.001; fructose 1-6 diphosphate vs. sham, NS). The results are discussed and explained in terms of the postulated mechanism based on the pharmacological properties of fructose 1-6 diphosphate.

[An experimental study on the use of the umbilical vein in blood vessel transplantation and its clinical application]

An experimental study of human umbilical vein in the use of femoral artery and jugular vein transplantation was carried out, and three patients suffering from superior vena caval obstruction were operated on by umbilical vein transplantation. The patients were followed up for 4-7 months with good results. It was found that the umbilical vein was a very good alternative in blood vessel transplantation for its lacking valves, its even caliber, its easiness to obtain, its length of up to 20 cm and a caliber of 0.3-1.0 cm, its ability to bear a pressure of up to 300 mmHg, and its causing no rejection after glutaraldehyde pretreatment. The processing and preserving of the umbilical vein were presented in detail, and its clinical implication was discussed.

Time-dependent absorption of phenprobamate following multiple dosing in rats

Unusual serum profiles of phenprobamate, a centrally skeletal muscle relaxant, were observed in Sprague Dawley rats receiving multiple doses of phenprobamate suspension. The concentrations of phenprobamate were higher after the morning doses than after the evening doses, synchronizing with the day-night pattern of drug administration. Crossover studies were conducted to investigate the apparent time-dependent kinetics of phenprobamate. Phenprobamate emulsion was orally administered as a single dose to a group of six rats at 0900 hr and again, after a washout period of 3 days, at 2100 hr. Another group of six rats was treated similarly with intraperitoneal drug administration. Blood samples were collected at various times for 12 hr. The AUCs were 146.56 +/- 31.77 micrograms.hr/ml for the morning oral dose and 111.31 +/- 21.32 micrograms.hr/ml for the evening oral dose (P less than 0.001). Administered intraperitoneally, the AUCs were 179.89 +/- 37.50 and 185.58 +/- 28.51 micrograms.hr/ml for the morning and evening doses, respectively, the difference of which was not significant. The paired t test indicated a significant morning-evening difference in AUC following oral but not intraperitoneal drug administration. This suggests the absorption rather than metabolism as a contributing factor to the time-dependent kinetics of phenprobamate in rats.

High-performance liquid chromatographic analysis, plasma protein binding and red blood cell partitioning of phenprobamate

A new high-performance liquid chromatographic procedure for the analysis of phenprobamate, a skeletal muscle relaxant in biologic fluids was developed. The method used a C18 reverse phase column, a mobile phase of methanol/acetonitrile/water (33:15:52), and UV detection at 215 nm. The assay procedure was applied to the determination of phenprobamate binding to rat and human plasma proteins using the equilibrium dialysis method. In addition, the red blood cell/plasma partitioning was determined in the whole blood of rats and humans. Phenprobamate exhibited a moderate binding to plasma proteins of rat (74.3 +/- 2.2 per cent) and human (80.5 +/- 1.1 per cent). The protein binding was concentration-independent in the range of 10 to 80 micrograms ml-1. Phenprobamate binding to plasma proteins was also determined in the presence of 10 micrograms ml-1 acetaminophen. The protein binding of phenprobamate was not significantly altered by acetaminophen (74.4 +/- 0.6 per cent for rat plasma; 75.7 +/- 1.6 per cent for human plasma). The distribution ratios of phenprobamate between the red blood cells and plasma were greater than unity, 1.86 and 1.59 in rat and human, respectively, indicating a preferential partitioning of the drug in the red blood cells.