[Phenotype and genotype analyses of two pedigrees with inherited fibrinogen deficiency]

Objective: To analyze the phenotype and genotype of two pedigrees with inherited fibrinogen (Fg) deficiency caused by two heterozygous mutations. We also preliminarily probed the molecular pathogenesis. Methods: The prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT) and plasma fibrinogen activity (Fg∶C) of all family members (nine people across three generations and three people across two generations) were measured by the clotting method. Fibrinogen antigen (Fg:Ag) was measured by immunoturbidimetry. Direct DNA sequencing was performed to analyze all exons, flanking sequences, and mutated sites of FGA, FGB, and FGG for all members. Thrombin-catalyzed fibrinogen polymerization was performed. ClustalX 2.1 software was used to analyze the conservatism of the mutated sites. MutationTaster, PolyPhen-2, PROVEAN, SIFT, and LRT online bioinformatics software were applied to predict pathogenicity. Swiss PDB Viewer 4.0.1 was used to analyze the changes in protein spatial structure and molecular forces before and after mutation. Results: The Fg∶C of two probands decreased (1.28 g/L and 0.98 g/L, respectively). The Fg∶Ag of proband 1 was in the normal range of 2.20 g/L, while it was decreased to 1.01 g/L in proband 2. Through genetic analysis, we identified a heterozygous missense mutation (c.293C>A; p.BβAla98Asp) in exon 2 of proband 1 and a heterozygous nonsense mutation (c.1418C>G; p.BβSer473*) in exon 8 of proband 2. The conservatism analysis revealed that Ala98 and Ser473 presented different conservative states among homologous species. Online bioinformatics software predicted that p.BβAla98Asp and p.BβSer473* were pathogenic. Protein models demonstrated that the p.BβAla98Asp mutation influenced hydrogen bonds between amino acids, and the p.BβSer473* mutation resulted in protein truncation. Conclusion: The dysfibrinogenemia of proband 1 and the hypofibrinogenemia of proband 2 appeared to be related to the p.BβAla98Asp heterozygous missense mutation and the p.BβSer473* heterozygous nonsense mutation, respectively. This is the first ever report of these mutations.

[Development of a Ranking Tool for Scientificity, Transparency and Applicability of Clinical Practice Guidelines]

Objective: To address the limitations of existing methods and tools for evaluating clinical practice guidelines, we aimed to develop a comprehensive instrument focusing on the three main dimensions of guideline development: scientificity, transparency, applicability. We will use it to rank the guidelines according to the scores. We abbreviated it as STAR, and its reliability, validity and usability were also tested. Methods: A multidisciplinary expert working group was set up, including methodologists, statisticians, journal editors, medical professionals, and others. Scoping review, Delphi methods and hierarchical analysis were used to determine the final checklist of STAR. Results: The new instrument contained 11 domains and 39 items. Intrinsic reliability of each domain was indicated by Cronbach's α coefficient, with a average value of 0.646. The Cohen's kappa coefficients for methodological evaluators and clinical evaluators were 0.783 and 0.618. The overall content validity index was 0.905. The R2 for the criterion validity analysis was 0.76. The average score for usability of the items was 4.6, and the mean time spent to evaluate each guideline was 20 minutes. Conclusion: The instrument has good reliability, validity and evaluating efficiency, and can be used for evaluating and ranking guidelines more comprehensively.

Improved tenderness of beef from bulls supplemented with active dry yeast is related to matrix metalloproteinases and reduced oxidative stress

Supplementing diets with active dry yeast (ADY, Saccharomyces cerevisiae) improves the carcass quality grade of beef cattle and the tenderness of beef. The relevant mechanisms have not been fully elucidated, but may be related to the effect of ADY on oxidative stress and the activity of matrix metalloproteinases (MMPs). To provide further insight into these mechanisms, this study evaluated the influence of ADY supplementation on growth performance, carcass traits, meat quality, concentrations of MMPs in serum (MMP-2, MMP-9 and MMP-13), oxidative stress indices and antioxidant capacity indices in beef cattle. Forty-six crossbred Simmental × Yanbian bulls (∼18 months of age, BW 436 ± 35 kg) participated in a 145-day finishing trial. ADY supplementation significantly improved marbling deposition, intramuscular fat content, and beef tenderness (P < 0.05); altered individual fatty acid proportions in the beef and increased saturated fatty acids while decreasing polyunsaturated fatty acids (P < 0.05); significantly decreased the abundance of reactive oxygen species in serum and meat; significantly increased the level of superoxide dismutase in meat (P < 0.05); tended to increase the level of catalase (P = 0.075) in serum and glutathione reductase (P = 0.066) in meat; and increased the secretion of MMPs. The improvement of beef tenderness following ADY supplementation of finishing bulls is related to the effects of ADY on the secretion of MMPs and the lowering of oxidative stress.

[Clinical phenotype and gene mutation analysis of 12 patients with hereditary protein C deficiency in different families]

Objective: To investigate the molecular pathogenesis and clinical features of unrelated 12 patients with inherited coagulation protein C (PC) deficiency in Chinese population. Methods: The PC activity (PC:A) and PC antigen (PC:Ag) were detected by chromogenic substrate and enzyme linked immunosorbent assay, respectively. The nine exons and flanking sequences of the protein C (PROC) gene were amplified by polymerase chain reaction with direct sequencing, and the suspected mutations were validated by reverse sequencing (clone sequencing for deletion mutations) . Results: The PC:A of the 12 probands decreased significantly, ranging from 18% to 55%, and the PC:Ag of the 10 probands decreased significantly. Eleven mutations were found, out of which four mutations [c.383G>A (p.Gly128Asp) , c.997G>A (p.Ala291Thr) , c.1318C>T (p.Arg398Cys) , and c.532G>C (p.Leu278Pro) ] were discovered for the first time. Six mutations were in the serine protease domain, four mutations were located in epidermal growth factor (EGF) -like domains, and one mutation was located in activation peptide. There were two deletion mutations (p.Met364Trp fsX15 and p.Lys192del) , and the rest were missense mutations. Mutations p.Phe181Val and p.Arg189Trp were identified in three unrelated families. All mutations may be inherited, and consanguineous marriages were reported in two families. Among the probands, nine cases had venous thrombosis, two cases had poor pregnancy manifestations, and one case had purpura. Conclusion: Patients with PC deficiency caused by PROC gene defects are prone to venous thrombosis, especially when there are other thrombotic factors present at the same time.

[Analysis of a pedigree with inherited factor V deficiency caused by compound heterozygous mutation]

Objective: To explore the molecular pathogenesis of a family with hereditary factor Ⅴ (FⅤ) deficiency. Methods: All the exons, flanking sequences, 5' and 3' untranslated regions of the F5 of the proband, and the corresponding mutation sites of the family members were analyzed via direct DNA sequencing. The CAT measurement was used to detect the amount of thrombin produced. The ClustalX software was used to analyze the conservation of mutation sites. The online bioinformatics software, Mutation Taster, PolyPhen-2, PROVEAN, LRT, and SIFT were applied to predict the effects of mutation sites on protein function. The Swiss-PdbViewer software was used to analyze the changes in the protein model and intermolecular force before and after amino acid variation. Results: The proband had a heterozygous missense mutation c.1258G>T (p.Gly392Cys) in exon 8 of the F5, and a heterozygous deletion mutation c.4797delG (p.Glu1572Lys fsX19) in exon 14, which results in a frameshift and produces a truncated protein. Her grandfather and father had p.Gly392Cys heterozygous variation, whereas her maternal grandmother, mother, little aunt, and cousin all had p.Glu1572LysfsX19 heterozygous variation. The ratio of proband's thrombin generation delay to peak time was significantly increased. Conservation analysis results showed that p.Gly392 was located in a conserved region among the 10 homologous species. Five online bioinformatics software predicted that p.Gly392Cys was pathogenic, and Mutation Taster also predicted p.Glu1572Lys fsX19 as a pathogenic variant. Protein model analysis showed that the replacement of Gly392 by Cys392 can lead to the extension of the original hydrogen bond and the formation of a new steric hindrance, which affected the stability of the protein structure. Conclusion: The c.1258G>T heterozygous missense mutation in exon 8 and the c.4797delG heterozygous deletion mutation in exon 14 of the F5 may be responsible for the decrease of FⅤ levels in this family.

Effect of Lonicera japonica extract on lactation performance, antioxidant status, and endocrine and immune function in heat-stressed mid-lactation dairy cows

Here, we examined the effects of Lonicera japonica extract (LJE) on lactation performance, antioxidant status, and endocrine and immune function in heat-stressed mid-lactation dairy cows. Twenty-four healthy Chinese Holstein mid-lactation dairy cows, all with similar milk yield (30.0 ± 1.0 kg/d), parity (2.5 ± 0.3), and days in milk (105 ± 5 d) were allocated to 4 groups using a randomized complete block design: a negative control group (without LJE supplementation; CON) and groups that received LJE at 14, 28, and 56 g/d. The experiment lasted 10 wk over a hot summer, with a pre-feeding period of 2 wk. Cows were exposed to heat stress, as the average temperature-humidity index was greater than 72. The results showed that LJE had no effect on respiration rate; however, it reduced the rectal temperature of dairy cows experiencing heat stress in both a linear and quadratic manner; the lowest (39.03°C) was recorded for the LJE-28 group, lower than the CON group. Supplementation with LJE did not affect dry matter intake, milk yield, or milk composition. The majority of biochemical parameters in serum were unaffected by supplementation with different amounts of LJE; the exception was creatinine, which was reduced quadratically. Compared with the CON group, serum triiodothyronine concentrations increased significantly in the LJE-28 group. Addition of LJE to the diet increased thyroxine concentrations quadratically; values peaked at 18.62 ng/mL in the LJE-28 group. Furthermore, supplementation with increasing amounts of LJE quadratically increased the activity of glutathione peroxidase and total antioxidant capacity in serum but decreased concentration of malondialdehyde. Although we detected no differences in the concentrations of IgA, IgM, or cytokines, dairy cows in the LJE-28 group had higher IgG and IL-4 concentrations than did cows in the CON group. Supplementation with LJE increased concentrations of IgG and IL-4 in the serum quadratically but decreased that of IL-2. Finally, heat shock protein 72 concentrations in the serum tended to fall quadratically as the amount of LJE increased. In summary, LJE had no negative effects on lactation performance but helped to alleviate heat stress by improving antioxidant status and promoting endocrine and immune functions. Supplementation with LJE at 28 g/d is recommended for lactating dairy cows experiencing heat stress during hot summers.

[Risk considerations of periodontal tissues reconstructions in the strategies of orthodontic treatment]

With the increase of adult patients seeking for orthodontic treatment, the influence of periodontal tissue on orthodontic treatment has gradually become the focus. For patients with periodontitis, it is essential to controlling the severity of periodontitis prior to orthodontic treatment. Periodontal disease can cause additional bone loss and make the orthodontic treatment complicated. Reducing the risk of orthodontic treatment in this situation is our major concern. In addition to periodontitis, orthodontic treatment may also cause gingival recession. On the other hand, the alveolar bone defects such as bone fenestration and bone dehiscence are common in some patients without periodontitis. For these patients, we should take more care of the interrelationship between bone defects and orthodontic treatment. This article briefly demonstrates the risk considerations of periodontal supporting tissue in orthodontic therapy focusing on the influence of periodontitis, gingival recession and alveolar bone fenestration and dehiscence.

Effects of dietary energy and crude protein levels on growth performance, blood profiles, and carcass traits in growing-finishing pigs

This experiment was conducted to evaluate the effect of dietary energy and crude protein (CP) levels on growth performance, blood profiles, and carcass traits in growing-finishing pigs. A total of 180 crossbred pigs ([Yorkshire × Landrace] × Duroc) with an average body weight of 30.96 ± 3.068 kg were used for a 12-week feeding trial. Experimental pigs were allotted to a 2 × 3 factorial arrangement using a randomized complete block (RCB) design. The first factor was two levels of dietary metabolizable energy (ME) density (13.40 MJ/kg or 13.82 MJ/kg), and the second factor was three dietary CP levels based on subdivision of growing-finishing phases (high: 18%/16.3%/16.3%/13.2% middle: 17%/15.3%/15.3%/12.2% and low: 16%/14.3%/14.3%/11.2%). Average daily gain (ADG) and gain-feed ratio (G:F ratio) decreased as dietary CP level was decreased linearly (linear, p < 0.05; p < 0.05, respectively) in the early growing period, and G:F ration also decreased as dietary CP level was decreased linearly (linearly, p < 0.05) over the whole growing phase. Over the entire experimental period, G:F ratio decreased as dietary ME level decreased (p = 0.01). Blood urea nitrogen (BUN) concentration was increased as dietary energy level decreased in growing period (p < 0.01). During finishing period, total protein concentration was decreased by lower dietary energy level (p < 0.05). In this study, there were no significant differences in proximate factors, physiochemical properties, muscle TBARS assay results, pH changes, or color of pork by dietary treatments. However, saturated fatty acid (SFA) increased (p < 0.01) and polyunsaturated fatty acid (PUFA) decreased (p < 0.05) when ME was decreased by 0.42 MJ/kg in growing-finishing pig diets. In addition, monounsaturated fatty acid (MUFA) tended to increase when CP level was decreased in growing-finishing pig diets (p = 0.06). A growing-finishing diet of 13.82 MJ/kg diet of ME with the high CP level can improve growth performance and show better fatty acids composition of pork.

Effects of dietary energy and protein levels on reproductive performance in gestating sows and growth of their progeny

This experiment was conducted to evaluate the effect of dietary energy and crude protein (CP) levels on reproductive performance, litter performance, milk quality, and blood profiles in gestating sows. A total of 59 multiparous sows (Yorkshire × Landrace) with similar body weights (BW), backfat thickness (BF), and parity were assigned to one of six treatments with 9 or 10 sows per treatment using a 2 × 3 factorial arrangement and completely randomized design. The first factor was two levels of dietary metabolizable energy (ME) density (13.40 or 13.82 MJ/kg) and the second factor was three dietary protein levels based from 35 day in gestating phases (10.5%, 12%, and 13.5%). Backfat thickness change in lactating sows decreased linearly as CP level increased (p = 0.03). Increased energy level in the gestating sow diet tended to increase the total number of piglets born (p = 0.07), but piglet weight decreased (p = 0.02). Dietary CP level had a negative effect on colostrum quality. Casein, protein, total solid, and solids-not-fat concentrations decreased linearly and lactose level increased linearly as CP level in the gestating sow diet increased (casein%: p = 0.03; protein%: p = 0.04; lactose%: p = 0.06; total solids: p = 0.03; solid-not-fat: p = 0.03, respectively). However, improving ME by 0.42 MJ/kg had no significant effect on the chemical composition of sow colostrum. There were no significant differences in blood glucose concentration in gestating sows when sows were fed different levels of energy during gestation, but blood glucose increased at 21 day of lactation when energy increased by 0.42 MJ/kg (p = 0.04). Blood urea nitrogen concentration increased linearly when dietary CP levels increased at 110 day in gestation, 24-hours postpartum, and 21 days of lactation (linear, p < 0.05, p < 0.05, and p < 0.05, respectively), and it also increased when dietary energy increased at 110 days of gestation and 24-hours postpartum (p < 0.01, and p < 0.01, respectively). A gestating sow diet containing 13.82 MJ/kg ME and 10.5% CP can improve reproductive performance, litter performance, and colostrum quality.

[Transurethral bipolar plasmakinetic prostatectomy for benign prostatic hyperplasia in high-risk and senior patients in China: a systematic review and meta-analysis]

Objective: To evaluate the effectiveness and safety of transurethral bipolar plasmakinetic prostatectomy in the treatment of benign prostatic hyperplasia in high-risk and senior patients in China. Methods: The PubMed, Cochrane Library, CBM, CNKI and WanFang databases were searched with computer for collecting relevant interventional case series from establishment dates to September 14, 2018. After quality evaluation and data extraction independently conducted by two authors, the Meta-analysis was performed using the Comprehensive Meta-analysis V2 software. Results: Eighteen studies involving 1 899 patients are included. Maximum flow rate increased to 12.28 ml/s (95%CI: 8.42-16.14), 12.88 ml/s (95%CI: 9.85-15.92) ,14.32 ml/s (95%CI: 10.47-18.18), 14.93 ml/s (95%CI: 10.19-19.67) and 20.00 ml/s (95%CI: 19.08-20.92) in 1, 3, 6, 12 and 24 months after surgery, respectively. International prostate symptom score decreased to -18.60 (95%CI: -23.20--14.00), -17.62 (95%CI: -20.21--15.03), -19.14 (95%CI: -20.70--17.59), -19.06 (95%CI: -21.53--16.60) and -22.90 (95%CI: -24.26--21.54), respectively. Quality of life decreased to -2.38 (95%CI: -4.26--0.50), -3.39 (95%CI: -4.57--2.21),-3.75 (95%CI: -4.14--3.36), -3.36(95%CI: -4.56--2.16), and -4.58(95%CI: -4.75--4.41). Post void residual decreased to -231.16 ml (95%CI: -288.30--174.01), -76.10 ml (95%CI: -116.71--35.50), -159.90 ml(95%CI: -207.21--112.59) and -87.70 ml (95%CI: -91.91--83.48). The event rate of postoperative adverse reactions all were not high. Conclusion: Transurethral bipolar plasmakinetic prostatectomy has better clinical efficacy and no obvious side effects in the treatment of benign prostatic hyperplasia in high-risk and senior patients in China.

Effects of dietary energy and crude protein levels on growth performance, blood profiles, and nutrient digestibility in weaning pigs

Objective

This experiment was conducted to investigate the effect of reducing dietary metabolic energy (ME) and crude protein (CP) levels on growth performance, blood profiles, and nutrient digestibility in weaning pigs.

Methods

A total of 240 crossbred pigs (Duroc×[Landrace×Yorkshire]) with an average body weight of 8.67±1.13 kg were used for a 6-week feeding trial. Experimental pigs were allotted to a 2×3 factorial arrangement using a randomized complete block design. The first factor was two levels of dietary ME density (low ME level, 13.40 MJ/kg or high ME level, 13.82 MJ/kg) and the second factor was three dietary CP levels based on subdivision of early and late weaning phases (low CP level, 19.7%/16.9%; middle CP level, 21.7%/18.9%; or high CP level, 23.7%/20.9%).

Results

Over the entire experimental period, there were no significant difference in body weight among groups, but a decrease in diet energy level was associated with an increase in average daily feed intake (p = 0.02) and decrease in gain-feed ratio (G:F) ratio (p<0.01). Decreased CP levels in the diet were associated with a linear increase in average daily gain (p< 0.05) and quadratic increase in G:F ratio (p<0.05). In the early weaning period, blood urea nitrogen concentration tended to increase when ME in the diet decreased and decrease when CP level in the diet decreased (p = 0.09, p<0.01, respectively). Total protein concentration tended to increase when CP level was reduced (p = 0.08). In the late weaning period, blood urea nitrogen concentration decreased linearly as CP level decreased (p<0.01). The CP and crude fat digestibility decreased when ME was decreased by 0.42 MJ/kg (p = 0.05, p = 0.01, respectively). The CP digestibility increased linearly as CP level decreased (p = 0.01).

Conclusion

A weaning pig diet containing high ME level (13.82 MJ/kg) and low CP level (19.7%/16.9%) can improve pig growth performance and nutrient digestibility.

Effect of Dietary sugar beet pulp supplementation on growth performance, nutrient digestibility, fecal Microflora, blood profiles and Diarrhea incidence in weaning pigs

Background

In 2006, the European Union (EU) has decided to forbid use of antibiotics as growth promoters. Although many researches had been conducted about fiber source as alternatives of antibiotics, there are still lack of reports in the literature about the optimum level of sugar beet pulp supplementation, affecting growth performance and nutrient digestibility in weaning pigs. Therefore, different level of sugar beet pulp was added to diets to determine the effects of sugar beet pulp supplementation on growth performance, nutrient digestibility, fecal microflora, blood profile and incidence of diarrhea in weaning pigs.

Methods

A total of 200 weaning pigs [(Yorkshire × Landrace) × Duroc], averaging 9.01 ± 1.389 kg of initial body weight were, allotted to 5 treatments in a randomized complete block (RCB) design. Each treatment was composed of 4 replicates with 10 pigs per pen. The treatments were control treatment: Corn-SBM basal diet + ZnO (phase 1: 0.05%; phase 2; 0.03%) and four different levels of sugar beet pulp were supplemented in Corn-SBM basal diet (3, 6, 9 or 12%). Two phase feeding programs (phase 1: 1–2 weeks; phase 2: 3–5 weeks) were used for 5 week of growth trial.

Results

In feeding trial, there were no significant differences in growth performance and incidence of diarrhea among treatments. The E.coli counts were not significantly different among dietary treatments but linear response was observed in Lactobacillus counts as sugar beet pulp supplementation increased (P < 0.05). In addition, IGF-1, IgA and IgG were not affected by dietary treatments. However, the BUN concentration was decreased when pigs were fed the treatments of diets with SBP compared to that of control treatment (P < 0.05). In nutrient digestibility, crude fiber and NDF digestibilities were improved as the sugar beet pulp increased (P < 0.05). However, digestibilities of crude ash, crude fat, crude fiber and nitrogen retention were not affected by dietary sugar beet pulp levels.

Conclusion

This experiment demonstrated that sugar beet pulp can be supplemented in weaning pigs’ diet instead of ZnO to prevent postweaning diarrhea without any detrimental effect on growth performance.

Are Economic Development and Education Improvement Associated with Participation in Transnational Terrorism?

Using transnational terrorism data from 1980 to 2000, this study empirically examines the relationships between frequency of participation in transnational terrorism acts and economic development and education improvement. We find an inverse U-shaped association between the frequency of various nationals acting as perpetrators in transnational terrorism acts and per capita income in their respective home countries. As per capita incomes increase from relatively low levels, frequencies of participation in transnational terrorism increase. However, at sufficiently higher levels of per capita income, further increase in per capita income is negatively associated with the rate of participation in transnational terrorism. Education improvement from elementary to secondary is positively correlated with frequency of participation in transnational terrorism events, whereas further improvement from secondary to tertiary level is negatively correlated with participation in transnational terrorism. We also find that citizens of countries with greater openness to international trade, lower degree of income inequality, greater economic freedom, larger proportion of population with tertiary education, and less religious prevalence participate in transnational terrorism events less frequently.

Evaluation of mental status HIV-infected patients: implications for treatment

OBJECTIVES

The aim of the study was to explore factors that may influence mental health status of HIV-infected patients, and to figure out a method that could effectively classify the patients by evaluating the severity of their mental health problems.

METHODS

Eighty-five patients were recruited and divided into two groups: the low risk group (LRG, n = 38) and the high risk group (HRG, n = 47). All patients finished Symptom Check-List 90 Revised (SCL-90-R) which is a multidimensional questionnaire designed to screen for a broad range of psychological problems.

RESULTS

SCL-90-R scores of HRG were significantly higher than those of the general population and did not differ from those of psychosomatic outpatients. Scores of LRG were significantly lower than those of psychosomatic outpatients and did not differ from those of the general population in most subscales. HIV-infected men having sex with men and unemployed patients had much higher incidence of mental health problems.

CONCLUSION

Besides undistinguishable group psychotherapy, we call for a clinical screening by psychological questionnaires at the first step, and then at-risk or high-risk patients should be given corresponding and individualized treatments. More attention and health care should be given to HIV-infected men who have sex with men and unemployed patients.

Effect of morphine on the release of excitatory amino acids in the rat hind instep: Pain is modulated by the interaction between the peripheral opioid and glutamate systems

Behavioral evidence supports a role for peripheral glutamate receptors in normal nociceptive transmission. In this study, we examined the release of the excitatory amino acids, glutamate and aspartate, in the s.c. perfusate of the rat hind instep by in vivo microdialysis. Antidromic stimulation of the sciatic nerve and noxious stimuli in the form of heat stimulation and local application of capsaicin cream (1%) to the instep caused an increase in excitatory amino acid release. This capsaicin-induced excitatory amino acid release was suppressed by pretreatment with capsaicin. Both systemic (10 mg/kg, i.v.) and local injections (10(-5) M in the perfusate) of morphine inhibited the increase in excitatory amino acid release evoked by local application of capsaicin cream to the instep. This inhibitory effect of morphine was antagonized by naloxone either given systemically (5 mg/kg, i.v.) or locally (10(-5) M). These results suggest that excitatory amino acids are released from small diameter afferent fibers by heat stimulation in the periphery or local application of capsaicin cream, and that activation of opioid receptors, present on the peripheral endings of small-diameter afferent fibers, can regulate noxious stimulus-induced excitatory amino acid release.

Practical synthesis of D-cyclopent-2-enone, the key intermediate of carbocyclic nucleosides

An efficient and practical method for the synthesis of (4R,5R)-4,5-O-isopropylidene-cyclopent-2-enone was developed from D-ribose by using a ring-closing metathesis reaction.

Antiviral activity of cyclopentenyl nucleosides against orthopox viruses (Smallpox, monkeypox and cowpox)

An improved method for the synthesis of enantiomerically pure D-cyclopentenyl nucleosides has been accomplished and their antiviral activity against orthopox viruses have been evaluated. The key intermediate, L-cyclopent-2-enone 13 was prepared from D-ribose using a ring closing metathesis reaction in eight steps. Among the synthesized nucleosides, the adenine 2 (Neplanocin A), cytosine 14, and 5-F-cytosine 15 analogues exhibited potent anti-orthopox virus activity, including smallpox virus.

Genes required for ionizing radiation resistance in yeast

The ability of Saccharomyces cerevisiae to tolerate ionizing radiation damage requires many DNA-repair and checkpoint genes, most having human orthologs. A genome-wide screen of diploid mutants homozygous with respect to deletions of 3,670 nonessential genes revealed 107 new loci that influence gamma-ray sensitivity. Many affect replication, recombination and checkpoint functions. Nearly 90% were sensitive to other agents, and most new genes could be assigned to the following functional groups: chromatin remodeling, chromosome segregation, nuclear pore formation, transcription, Golgi/vacuolar activities, ubiquitin-mediated protein degradation, cytokinesis, mitochondrial activity and cell wall maintenance. Over 50% share homology with human genes, including 17 implicated in cancer, indicating that a large set of newly identified human genes may have related roles in the toleration of radiation damage.

Intestinal bacterial beta-glucuronidase activity of patients with colon cancer

The fecal beta-glucuronidase activity of patients with colon cancer and healthy controls were measured to determine the relationship between the fluctuation of intestinal bacterial beta-glucuronidase and colon cancer. The fecal beta-glucuronidase activity of patients with colon cancer was 1.7 times higher than that of the healthy controls. However, when these fecal specimens were sonicated, the enzyme activity of patients with colon cancer was 12.1 times higher than that of the healthy controls. The fecal beta-glucuronidase activity of human intestinal bacteria was drastically induced by its substrate or the bile secreted after a subcutaneous injection of 1,2-dimethylhydrazine (DMH) and benzo[a]pyrene into rats. DMH- and benzo[a]pyrene-treated biles induced beta-glucuronidase activity in the human intestinal microflora by approximately 1.5- and 2.3-fold, respectively. They also induced beta-glucuronidase in E. coli HGU-3, which is a beta-glucuronidase-producing bacterium from the human intestine. D-saccharic acid 1,4-lactone similarly inhibited fecal beta-glucuronidase in several patients with colon cancer in addition to the healthy controls. This suggests that potent beta-glucuronidase activity is a prime factor in the etiology of colon cancer.

Protein tyrosine kinase inhibitors modulate radiosensitivity and radiation-induced apoptosis in K562 cells

We studied the modulating effect of protein tyrosine kinase inhibitors on the response of cells of the human chronic myelogenous leukemia cell line K562 to radiation. The radiosensitivity of the cells was increased by treatment with herbimycin A and decreased by treatment with genistein. This modulating effect of protein tyrosine kinase inhibitors on radiation sensitivity was associated with the alteration of the mode of radiation-induced cell death. After X irradiation, the cells arrested in the G(2) phase of the cell cycle, but these TP53(-/-) cells were unable to sustain cell cycle arrest. This G(2)-phase checkpoint deficit caused cell death. The morphological pattern of cell death was characterized by swelling of the cytoplasmic compartments, cytosolic vacuolation, disruption of the plasma membrane, less evident nuclear condensation, and faint DNA fragmentation, all of which were consistent with oncosis or cytoplasmic apoptosis. The nonreceptor protein tyrosine kinase inhibitor herbimycin A accelerated the induction of typical apoptosis by X irradiation, which was demonstrated by morphological assessments using nuclear staining and electron microscopy as well as oligonucleosomal fragmentation and caspase 3 activity. Herbimycin A is known to be a selective antagonist of the BCR/ABL kinase of Philadelphia chromosome-positive K562 cells; this kinase blocks the induction of apoptosis after X irradiation. Our results showed that the inhibition of protein tyrosine kinase by herbimycin A enhanced radiation-induced apoptosis in K562 cells. This effect was associated with the activation of caspase 3 and rapid abrogation of the G(2)-phase checkpoint with progression out of G(2) into G(1) phase. In contrast, the receptor-type protein tyrosine kinase inhibitor genistein protected K562 cells from all types of radiation-induced cell death through the inhibition of caspase 3 activity and prolonged maintenance of G(2)-phase arrest. Further investigations using this model may give valuable information about the mechanisms of radiation-induced apoptosis and about the radiosensitivity and radioresistance of chronic myelogenous leukemia cells having the Philadelphia chromosome.

Cellular mechanisms of baroreceptor integration at the nucleus tractus solitarius

The autonomic nervous system makes important contributions to the homeostatic regulation of the heart and blood vessels through arterial baroreflexes, and yet our understanding of the central nervous system mechanisms is limited. The sensory synapse of baroreceptors in the nucleus tractus solitarius (NTS) is unique because its participation is obligatory in the baroreflex. Here we describe experiments targeting this synapse to provide greater understanding of the cellular mechanisms at the earliest stages of the baroreflex. Our approach utilizes electrophysiology, pharmacology, and anatomical tracers to identify and evaluate key elements of the sensory information processing in NTS.

The 3'-->5' exonuclease of DNA polymerase delta can substitute for the 5' flap endonuclease Rad27/Fen1 in processing Okazaki fragments and preventing genome instability

Many DNA polymerases (Pol) have an intrinsic 3'-->5' exonuclease (Exo) activity which corrects polymerase errors and prevents mutations. We describe a role of the 3'-->5' Exo of Pol delta as a supplement or backup for the Rad27/Fen1 5' flap endonuclease. A yeast rad27 null allele was lethal in combination with Pol delta mutations in Exo I, Exo II, and Exo III motifs that inactivate its exonuclease, but it was viable with mutations in other parts of Pol delta. The rad27-p allele, which has little phenotypic effect by itself, was also lethal in combination with mutations in the Pol delta Exo I and Exo II motifs. However, rad27-p Pol delta Exo III double mutants were viable. They exhibited strong synergistic increases in CAN1 duplication mutations, intrachromosomal and interchromosomal recombination, and required the wild-type double-strand break repair genes RAD50, RAD51, and RAD52 for viability. Observed effects were similar to those of the rad27-null mutant deficient in the removal of 5' flaps in the lagging strand. These results suggest that the 3'-->5' Exo activity of Pol delta is redundant with Rad27/Fen1 for creating ligatable nicks between adjacent Okazaki fragments, possibly by reducing the amount of strand-displacement in the lagging strand.

Balloon dacryocystoplasty: results and factors influencing outcome in 350 patients

PURPOSE

To evaluate the initial and long-term results of balloon dacryocystoplasty in the treatment of epiphora caused by obstruction of the lacrimal system with analysis of the procedure's favorable effects.

MATERIALS AND METHODS

Four hundred thirty eyes of 350 patients with obstructions of the lacrimal system were enrolled. Dacryocystoplasty was performed with use of a balloon catheter and a ball-tipped guide wire. The lesions were categorized according to cause, severity, site of the obstruction, and diameter and inflation time of the balloon. The technical success, initial success (improvement of symptoms after 1 week), and long-term patency rates were calculated. These rates in each group were compared with the chi(2) test and the Kaplan-Meier method.

RESULTS

The overall technical success rate was 95.3%. The overall initial success rate was 57.4%. There was no significant complication except for mild epistaxis in 12%. The 2-month, 1-year, and 5-year patency rates were 48.2%, 39.4%, and 36.9%, respectively. Initial success was influenced by the severity (P =.014) and the site (P <.001) of the obstruction, and the diameter of the balloon (P =.047). Long-term patency was affected by the site of the obstruction (P <.001) and the balloon inflation time (P <.001). Among the 183 initially ineffective and 88 recurrent cases, 62 underwent repeat balloon dacryocystoplasty, and the initial success rate was 38.7%.

CONCLUSIONS

The initial success rate of balloon dacryocystoplasty is relatively low. However, long-term patency can be expected in cases with initial success. Some additional factors also should be considered for better results.

Caspase 3-mediated cleavage of p21WAF1/CIP1 associated with the cyclin A-cyclin-dependent kinase 2 complex is a prerequisite for apoptosis in SK-HEP-1 cells

Apoptosis of SK-HEP-1 human hepatoma cells induced by treatment with ginsenoside Rh2 (G-Rh2) is associated with rapid and selective activation of cyclin A-associated cyclin-dependent kinase 2 (Cdk2). Here, we show that in apoptotic cells, the Cdk inhibitory protein p21(WAF1/CIP1), which is associated with the cyclin A-Cdk2 complex, undergoes selective proteolytic cleavage. In contrast, another Cdk inhibitory protein, p27(KIP1), which is associated with cyclin A-Cdk2 and cyclin E-Cdk2 complexes, remained unaltered during apoptosis. Ectopic overexpression of p21(WAF1/CIP1) suppressed apoptosis as well as cyclin A-Cdk2 activity induced by treatment of SK-HEP-1 cells with G-Rh2. The suppressive effects of p21(WAF1/CIP1) were much higher in the cells transfected with p21D112N, an expression vector that encodes a p21(WAF1/CIP1) mutant resistant to caspase 3 cleavage. Overexpression of cyclin A in SK-HEP-1 cells dramatically up-regulated cyclin A-Cdk2 activity and accordingly enhances apoptosis induced by treatment with G-Rh2. These up-regulating effects were blocked by coexpression of a dominant negative allele of cdk2. Furthermore, olomoucine, a specific inhibitor of Cdks, also blocked G-Rh2-induced apoptosis. These data suggest that the induction of apoptosis in human hepatoma cells treated with G-Rh2 occurs by a mechanism that involves the activation of cyclin A-Cdk2 by caspase 3-mediated cleavage of p21(WAF1/CIP1).

Fission yeast hrp1, a chromodomain ATPase, is required for proper chromosome segregation and its overexpression interferes with chromatin condensation

Hrp1 of Schizosaccharomyces pombe is a member of the CHD protein family, characterized by a chromodomain, a Myb-like telobox-related DNA-binding domain and a SNF2-related helicase/ATPase domain. CHD proteins are thought to be required for modification of the chromatin structure in transcription, but the exact roles of CHD proteins are not known. Here we examine the sub-cellular localization and biochemical activity of Hrp1 and the phenotypes of hrp1 Delta and Hrp1-overexpressing strains. Fluorescence microscopy revealed that Hrp1 protein is targeted to the nucleus. We found that Hrp1 exhibited DNA-dependent ATPase activity, stimulated by both single- and double-stranded DNA. Overexpression of Hrp1 caused slow cell growth accompanied by defective chromosome condensation in anaphase resulting in a 'cut' (celluntimelytorn) phenotype and chromosome loss. The hrp1 Delta mutation also caused abnormal anaphase and mini-chromosome loss phenotypes. Electron micrographs demonstrated that aberrantly shaped nucleoli appeared in Hrp1-overexpressing cells. Therefore, these results suggest that Hrp1 may play a role in mitotic chromosome segregation and maintenance of chromatin structure by utilizing the energy from ATP hydrolysis.

Characterization and gene cloning of monoclonal antibody specific for the hepatitis B virus X protein

The hepatis B virus X protein (HBx) has been thought to be implicated in the development of hepatocellular carcinoma. Although many functions of HBx have been reported, it is not clear which of HBx functions is important in hepatocellular carcinogenesis. To study HBx function, we produced a monoclonal anti-HBx Ab secreted by hybridoma cell clone H7 and mapped its epitope to a region of HBx between amino acids 29 and 48 by Western blot with truncated forms of HBx and by enzyme-linked immunoadsorbent assay (ELISA) with synthetic HBx peptides. The variable regions of H7 anti-HBx Ab were cloned by polymerase chain reaction using the degenerate-primers and by the 5' rapid amplification-cDNA end method. The sequence analyses revealed that the variable gene segments of the heavy and light chains are the members of mouse heavy chain variable gene 1 family and kappa light chain variable gene 2 family, respectively. In addition, J(H)2 or Jkappa4 gene segment at the end of the heavy-chain or light-chain variable region and DSP2.x gene segment in the CDR 3 of heavy chain were identified.

Diagnostic criteria for malignancy in bile cytology and its usefulness

Fifty three bile specimens from 42 patients were reviewed to assess the diagnostic role of the bile cytology and to define more reliable cytologic indicators of malignancy. Forty three bile specimens came from 34 patients with malignant biliary strictures and 10 bile specimens were from eight patients with benign conditions. There were no false positives. The diagnostic specificity of bile cytology was 100% while diagnostic sensitivity was 55.8%. Overall diagnostic accuracy was 64.2%. We identified four key criteria as cytologic indicators of malignancy among 20 variables by using multiple regression analysis: loss of honeycomb arrangement, hyperchromatism, increased N/C ratio, and coarse chromatin. When bile specimens with three or more of these four criteria are thought to represent malignancy, the sensitivity of diagnosis of malignancy was 65.2%, specificity was 90% and diagnostic accuracy was 69.8%.

Aloesin and arbutin inhibit tyrosinase activity in a synergistic manner via a different action mechanism

In this study, we present evidence that cotreatment of aloesin and arbutin inhibits tyrosinase activity in a synergistic manner by acting through a different action mechanism. Aloesin or arbutin similarly inhibited enzyme activity of human- and mushroom-tyrosinases with an IC50 value of 0.1 or 0.04 mM, respectively. Lineweaver-Burk plots of the enzyme kinetics data showed that aloesin inhibited tyrosinase activity noncompetitively with a Ki value of 5.3 mM, whereas arbutin did it competitively (Maeda, 1996). We then examined whether cotreatment of these agents inhibits the tyrosinase activity in a synergistic manner. The results showed that 0.01 mM aloesin in the presence of 0.03 mM arbutin inhibited activity of mushroom by 80% of the control value and the reverse was also true. The inhibitory effects were calculated to be synergistic according to the Bürgi method. Taken together, we suggest that aloesin along with arbutin inhibits in synergy melanin production by combined mechanisms of noncompetitive and competitive inhibitions of tyrosinase activity.

ATP-sensitive and Ca2+-activated K+ channel activities in the rat locus coeruleus neurons during metabolic inhibition

Locus coeruleus (LC) is the significant nucleus for consciousness and it is sensitive to metabolic inhibition. We investigated the effects of a metabolic inhibitor sodium cyanide (NaCN) on the rat dissociated LC neurons using nystatin-perforated patch recordings. Under voltage-clamp (VH=-40 mV), application of NaCN evoked outward currents composed of ATP-sensitive and Ca2+-dependent K+ channel currents (IKATP and IKCa2+). Onset of IKATP was faster than that of IKCa2+. Prolonged application of NaCN brought IKATP rundown but not IKCa2+ rundown. Okadaic acid prevented IKATP rundown, indicating that KATP channels are deactivated by dephosphorylation with protein phosphatase.

The immediate effect of bilateral superior obliuqe tenotomy on primary position horizontal binocular alignment

PURPOSE

To evaluate the effect on primary position horizontal binocular alignment of superior oblique tenotomy for A-pattern exotropia with bilateral superior oblique overaction using new surgical and anesthesia techniques.

SUBJECTS AND METHODS

We performed intraoperatively adjustable horizontal strabismus surgery under topical anesthesia in 6 cases of A-pattern exotropia. After adjusting the horizontal deviation nearly to orthotropia in primary position, we measured the angle of horizontal deviation in up-, primary, and downgaze positions. This was followed by bilateral superior oblique tenotomy and remeasurement of the horizontal deviation in the same 3 positions. Postoperatively we remeasured the deviation at one day, one month and three months.

RESULTS

There was no immediate change in the horizontal deviation in primary position in 2 of the 6 patients, and 3-8 delta of immediate esotropic shift in 4 of the 6 patients (average 3.3 delta) after bilateral superior oblique tenotomy. At 3 months postop' the small esotropia noted at the immediate postop' measurement became orthotropic. There was a tendency of increased exotropic shift or becoming exotropic in those patients with slight exotropia or orthotropia at the immediate postop' measurement. But these shifts were minimal.

CONCLUSION

When combined surgery of superior oblique and horizontal muscle is planned for A-pattern exotropia, the effect of bilateral superior oblique tenotomy on the primary position horizontal binocular alignment can be disregarded.

Functional reconstitution of a heteromeric cyclic nucleotide-gated channel of Caenorhabditis elegans in cultured cells

The tax-4 and tax-2 genes of Caenorhabditis elegans are essential for normal olfaction, gustation, and thermosensation, suggesting that they have a role in sensory transduction. The predicted products of these genes are similar to the cyclic nucleotide-gated (CNG) channel subunits used in vertebrate vision and olfaction: TAX-4 is highly related to those alpha subunits, while TAX-2 is most closely related to the beta subunits of the rod phototransduction channels. TAX-4 has previously been shown to form a highly sensitive cGMP-gated channel when expressed in human HEK293 cells. Here we show that TAX-4 and TAX-2 form a heteromeric channel when expressed in HEK293 cells, but TAX-2 does not form a channel on its own. Since these genes are expressed in the same neurons, most of the native channels in C. elegans are likely to be hetero-oligomers of TAX-4 and TAX-2 subunits, with TAX-4 as the alpha subunit and TAX-2 acting as a modifying beta subunit. The heteromeric TAX-4/TAX-2 channel is 25-fold less sensitive to cGMP than the TAX-4 channel, but it remains highly selective for cGMP over cAMP. The heteromeric channel and the TAX-4 homomeric channel differ in their blockage by divalent cations and in their single channel properties. These results suggest that cGMP is used as the second messenger during sensory signal transduction in C. elegans, and that distinct roles for alpha and beta subunits of CNG channels are conserved in vertebrate and invertebrate signal transduction.

Modulation of the glycine response by Ca2+-permeable AMPA receptors in rat spinal neurones

1. In acutely isolated rat sacral dorsal commisural nucleus (SDCN) neurones, application of kainate (KA) reversibly potentiated glycine-evoked Cl- currents (IGly) in a concentration-dependent manner. 2. The cellular events underlying the interaction between non-NMDA receptors and glycine receptors were studied by using nystatin-perforated patch and cell-attached single-channel recording modes. 3. The action of KA was not accompanied by a shift in the reversal potential for IGly. In dose-response curves, KA potentiated IGly without significantly changing glycine binding affinity. 4. GYKI 52466 blocked while NS-102 had no effect on the KA-induced potentiation of IGly. 5. The potentiation was reduced when KA was applied in a Ca2+-free extracellular solution or in the presence of BAPTA AM, and was independent of the activation of voltage-dependent Ca2+ channels. 6. Pretreatment with KN-62, a selective Ca2+-calmodulin-dependent protein kinase II (CaMKII) inhibitor, abolished the action of KA. Inhibition of calcineurin converted the KA-induced potentiation to a sustained one. 7. Single-channel recordings revealed that KA decreased the mean closing time of glycine-gated single-channel activity, resulting in an increase in the probability of channel opening. 8. It is proposed that Ca2+ entry through AMPA receptors modulates the glycine receptor function via coactivation of CaMKII and calcineurin in SDCN neurones. This interaction may provide a new postsynaptic mechanism for control of inhibitory synaptic signalling and represent one of the important regulatory mechanisms of spinal nociception.

Temperature-dependent effect of zolpidem on the GABAA receptor-mediated response at recombinant human GABAA receptor subtypes

The effects of zolpidem on the two forms of recombinant human GABAA receptors (alpha1beta2gamma2s and alpha3beta2gamma2s) at different temperatures were functionally investigated, using the whole-cell patch recording configuration. In both forms, zolpidem potentiated the response to GABA in a concentration-dependent manner. At 16 degrees C, the apparent dissociation constant (KD) values for the alpha1beta2gamma2s and alpha3beta2gamma2s forms were 3.7 x 10(-8) and 5.6 x 10(-7) M, respectively. When the temperature was increased to 36 degrees C, the KD values for the alpha1beta2gamma2s and alpha3beta2gamma2s forms were 2.1 x 10(-7) and 1.5 x 10(-6) M, respectively. Although the affinity ratio was reduced from 15.1 to 7.1-fold the selectivity of zolpidem for the alpha1beta2gamma2s still remained at 36 degrees C.

Characterization of electrogenic Na/K pump in rat neostriatal neurons

The electrogenic Na/K pump current (Ip) was studied in the dissociated neostriatal neurons of the rat by using the nystatin-perforated patch recording mode. The Ip was activated by external K+ in a concentration-dependent manner with an EC50 of 0.7 mM at a holding potential (VH) of -40 mV. Other monovalent cations also caused Ip and the order of potency was Tl+>K+, Rb+>NH4+, Cs+>>>Li+. The Ip decreased with membrane hyperpolarization in an external solution containing 150 mM Na+, while the Ip did not show such voltage dependency without external Na+. Ouabain showed a steady-state inhibition of Ip in a concentration- and temperature-dependent manner at a VH of -40 mV. The IC50 values at 20 and 30 degrees C were 7.1 x 10(-6) and 1.3 x 10(-6) M, respectively. The decay of Ip after adding ouabain well fitted with a single exponential function. At a VH of -40 Mv, the association (k+1) and dissociation (k-1) rate constants estimated from the time constant of the current decay at 20 degrees C were 4.0 x10(2) s-1 M-1 and 6.3 x 10(-3) s-1, respectively. At 30 degrees C, k+1 increased to 2.8 x 10(3) s-1 M-1 while k-1 showed no such change with a value of 1.8 x 10(-3) s-1. A continuous Na+ influx was demonstrated by both the Na+-dependent leakage current and tetrodotoxin-sensitive Na+ current, which resulted in the continuous activation of the Na/K pump. It was thus concluded that the Na/K pump activity was well-maintained in the dissociated rat neostriatal neurons with distinct functional properties and that the activity of the pump was tightly connected with Na+ influxes.

Reduction of Coupling Loss in a One-to-many Collimating System for a Wavelength Division (de)Multiplexer

In a 1 x N wavelength division (de)multiplexer, N receiving (Rx-) gradient-index-rod lenses (GRIN's) are connected to a common transmitting (Tx-) GRIN. All GRIN's are a little longer (DZ(0) for the Tx- and DZ(i) with i = 1, 2, ..., N for the Rx-GRIN's) than the quarter-pitch. To reduce the average coupling loss and the deviations, DZ(0) and DZ(i) are optimized independently (unequally) or equally by computer programming for small N, such as N = 4 and 8. For a larger N (e.g., 16), a relay GRIN is required, which is a little (DZ(r)) longer than the half-pitch. The best position of the relay GRIN is located between the seventh and the eighth Rx-GRIN's. Other parameters including DZ(0), DZ(i), and DZ(r) are all optimized. As a result the (de)multiplexer has lower losses.

Tandospirone-induced K+ current in acutely dissociated rat dorsal raphe neurones

1. The effects of tandospirone (TDS) on dissociated rat dorsal raphe neurones were investigated using the patch-clamp method. 2. Under current-clamp conditions, TDS hyperpolarized the cell membrane, resulting in the reduction of firing rates. 3. Under voltage-clamp conditions, TDS induced an inward rectifying K+ current in a concentration-dependent manner. 4. The TDS-induced K+ currents (I(TDS)) were mimicked by 8-OH-DPAT, a 5-HT1A agonist. The I(TDS) was blocked by spiperone, a 5-HT1A receptor antagonist, in a concentration-dependent manner. 5. N-Ethylmaleimide, an agent which uncouples between the receptor and the G-protein, irreversibly blocked the I(TDS). 6. In neurones perfused intracellularly with a pipette-solution containing GTP using the conventional whole-cell patch recording, the I(TDS) showed a gradual rundown. When the neurones were perfused with GTPgammaS, TDS activated the inwardly rectifying K+ current in an irreversible manner. 7. In the inside-out patch recording mode, TDS-activated single K+ channel currents (i(TDS)) which also showed an inward rectification. When the GDP in cytosolic side was completely replaced with GTP, the open probability of i(TDS) significantly increased. 8. These results indicate that the activation of 5-HT1A receptors by TDS directly opens the inward rectifying K+ channels via a G-protein mediated process.

Inhibitory effects of procainamide on rabbit platelet aggregation and thromboxane B2 production in vitro

AIM

To study the influences of procainamide (PA) on thrombin-induced rabbit platelet aggregation and thromboxane B2 (TXB2) production in vitro.

METHODS

Turbidimetry and radioimmunoassay were used.

RESULTS

PA 8.5, 34, 136, and 544 mumol.L-1 inhibited thrombin-induced platelet aggregation and TXB2 production, and the inhibitory rates were 45% +/- 37%, 48% +/- 32%, 88% +/- 23%, 92% +/- 15% and 53% +/- 24%, 65% +/- 26%, 90% +/- 6%, 95% +/- 6%, respectively. There was positive correlation between PA concentration and efficiency of inhibition of platelet aggregation and TXB2 production, and also between the inhibition % of platelet aggregation and that of production of TXB2. The three linear equations and main parameters were Y = 0.2075X-4.9157, r = 0.9985; Y = 0.9546X-34.6724, r = 0.9921; Y = 0.8202X + 19.7062, r = 0.9921.

CONCLUSION

PA inhibited thrombin-induced platelet aggregation and TXB2 production in rabbits.

Isolation and characterization of hrp1+, a new member of the SNF2/SWI2 gene family from the fission yeast Schizosaccharomyces pombe

The SNF2/SWI2 ATPase/helicase family comprises proteins from a variety of species, which serve a number of functions, such as transcriptional regulation, maintenance of chromosome stability during mitosis, and various types of DNA repair. Several proteins with unknown functions are also included in this family. The number of genes that belong to this family is rapidly expanding, which makes it easier to analyze the common biological functions of the family members. This study was designed to clone the SNF2/SWI2 helicase-related genes from the fission yeast Schizosaccharomyces pombe in the hope that this would help to elucidate the common functions of the proteins in this family. The hrp1+ (helicase-related gene from S. pombe) gene was initially cloned by PCR amplification using degenerate primers based on conserved SNF2 motifs within the ERCC6 gene, which encodes a protein involved in DNA excision repair. The hrp1+ ORF codes for an 1373-amino acid polypeptide with a molecular mass of 159 kDa. Like other SNF2/SWI2 family proteins, the deduced amino acid sequence of Hrp1 contains DNA-dependent ATPase/7 helicase domains, as well as a chromodomain and a DNA-binding domain. This configuration is similar to that of mCHD1 (mouse chromo-ATPase/helicase-DNA-binding protein 1), suggesting that Hrp1 is a S. pombe homolog of mCHD1, which is thought to function in altering the chromatin structure to facilitate gene expression. Northern blot analysis showed that the hrp1+ gene produces a 4.6-kb transcript, which reaches its maximal level just before the cells enter the exponential growth phase, and then decreases gradually. DNA-damaging agents, such as MMS, MNNG and UV, decrease the rate of transcription of hrp1+. Deletion of the hrp1+ gene resulted in accelerated cell growth. On the other hand, overexpression of Hrp1 caused a reduction in growth rate. These results indicate that hrp1+ may act as a negative regulator of cellular growth.

Developmental changes of GABA(A) receptor-chloride channels in rat Meynert neurons

The developmental changes of GABA(A) receptors were investigated in Meynert neurons freshly dissociated from day 0, 2 week-, and 6 month-old rats using both nystatin and gramicidin perforated patch recording modes under voltage-clamp conditions. The age-related changes in the current amplitude and threshold concentration in the concentration-response relationships for GABA indicated the developmental alteration of the GABA(A) receptor subunits and the channel density. The GABA-induced E(Cl-) measured by the gramicidin perforated patch mode shifted to more negative with development. The decay time constant of GABAergic inhibitory postsynaptic spontaneous currents (sIPSCs) in the synaptic active zone accelerated with aging. The GABA-induced currents were potentiated in a concentration dependent manner in the presence of benzodiazepine (BZP) agonists, diazepam (DZP) and zolpidem (ZPM). The potentiation rate of DZP on the GABA(A) response decreased with aging, but not in the case of ZPM, which demonstrated a stronger action in the aging rat neurons. These results suggested that the GABA(A) receptor x Cl- channel complexes may thus change both the assembly and interaction of subunits as well as their functional roles with aging.

Pleomorphic adenoma of the trachea

A case of salivary gland type pleomorphic adenoma of the trachea in a 48-year-old woman is presented. Pleomorphic adenoma is extremely rare in the trachea. The behavior of this tumor in the trachea appears to be similar to its counterpart in other sites and distinctly different from the more frequently encountered epithelial tumors.

Effects of benzodiazepine receptor agonists in neurones acutely dissociated from the rat neostriatum

To understand the properties of benzodiazepine receptor in the neostriatum, we examined the potentiating effects of diazepam, triazolam and brotizolam on the GABA(A) receptor-mediated Cl- current in dissociated rat neostriatal neurones using the nystatin-perforated patch recording configuration. Neurones were classified into large and small neurones, on their somatic size. In the large neurones, which are putative cholinergic interneurones, all the benzodiazepine receptor agonists recognized a single effective site. However, in the small neurones, which are mostly considered to be projecting neurones, the effect of brotizolam was best described when two effective sites were assumed. Therefore, the properties of benzodiazepine receptor differed among large and small neurones while at least two kinds of functional binding sites were also found to exist in small neurones.

A new mouse gene, SRG3, related to the SWI3 of Saccharomyces cerevisiae, is required for apoptosis induced by glucocorticoids in a thymoma cell line

We isolated a new mouse gene that is highly expressed in thymocytes, testis, and brain. This gene, SRG3, showed a significant sequence homology to SWI3, a yeast transcriptional activator, and its human homolog BAF155. SRG3 encodes 1,100 amino acids and has 33-47% identity with SWI3 protein over three regions. The SRG3 protein contains an acidic NH2 terminus, a myb-like DNA binding domain, a leucine-zipper motif, and a proline- and glutamine-rich region at its COOH terminus. Rabbit antiserum raised against a COOH-terminal polypeptide of the SRG3 recognized a protein with an apparent molecular mass of 155 kD. The serum also detected a 170-kD protein that seems to be a mouse homologue of human BAF170. Immunoprecipitation of cell extract with the antiserum against the mouse SRG3 also brought down a 195-kD protein that could be recognized by an antiserum raised against human SWI2 protein. The results suggest that the SRG3 protein associates with a mouse SWI2. The SRG3 protein is expressed about three times higher in thymocytes than in peripheral lymphocytes. The expression of anti-sense RNA to SRG3 mRNA in a thymoma cell line, S49.1, reduced the expression level of the SRG3 protein, and decreased the apoptotic cell death induced by glucocorticoids. These results suggest that the SRG3 protein is involved in the glucocorticoid-induced apoptosis in the thymoma cell line. This implicates that the SRG3 may play an important regulatory role during T cell development in thymus.