Possible significance of cells within intraluminal collagen masses in equine oviducts

In addition to the unique feature of retention of unfertilized ova, the oviducts of mares frequently contain large intraluminal masses with a fibrillar component and some cells. The aim of this study was to identify the cells and examine their relationship to the extracellular components of these masses. Intraluminal masses were examined both in situ and flushed from the oviducts. The nature of the contained cells and their relationship to the fibrils were examined by light microscopy and by transmission and scanning electron microscopy. In some mares the large masses distended the oviduct, but neither loss of the oviductal epithelium nor damage to this epithelium was seen. Electron microscopy verified that the principal cellular component was fibroblasts, and that the fibrils were type I collagen. Collagen masses collected shortly after ovulation frequently contained viable fibroblasts with collagen fibrils associated with their cell surfaces and with surface clefts. Although such collagen masses were present in pregnant and nonpregnant mares, masses with viable fibroblasts were chronologically associated with recent ovulation. It was concluded that connective tissue drawn into the oviduct at ovulation is retained, and collagen synthesis continues at least for a few days. Although the fibroblasts eventually disintegrate, the collagen remains and may in some cases aggregate within the oviductal lumen to the extent that oviductal transport and embryonic viability could be affected.     

Power control mixing C/I balancing and constant-received signalstrength in CDMA mobile communications system

A power control algorithm mixing C/I balancing with constant-received power control has been proposed. It is shown that the outage probability can be reduced by using the new algorithm. The new algorithm also provides better performance than the approximated optimum centralised power control algorithm if the number of removed mobiles is small     

Differential susceptibilities of Anopheles albimanus and Anopheles pseudopunctipennis to infections with coindigenous Plasmodium vivax variants VK210 and VK247 in southern Mexico

The susceptibilities to coindigenous Plasmodium vivax of colonized Anopheles albimanus and Anopheles pseudopunctipennis from southern Mexico were investigated by simultaneous feeding with infected blood obtained from patients. The genes encoding circumsporozoite protein variant types (VK210 and VK247) in blood samples were determined by PCR and oligonucleotide probe hybridization. A. albimanus was more susceptible to VK210, and A. pseudopunctipennis was more susceptible to VK247.     

Effects of vitamin E and C supplementation on oxidative stress and viral load in HIV-infected subjects

OBJECTIVES: The HIV-infected population is known to be oxidatively stressed and deficient in antioxidant micronutrients. Since in vitro replication of HIV is increased with oxidative stress, this study assessed the effect of antioxidant vitamin supplementation on lipid peroxidation, a measure of oxidative stress, and viral load in humans. DESIGN: A randomized placebo-controlled, double-blind study. METHODS: Forty-nine HIV-positive patients were randomized to receive supplements of both DL-alpha-tocopherol acetate (800 IU daily) and vitamin C (1000 mg daily), or matched placebo, for 3 months. Plasma antioxidant micronutrient status, breath pentane output, plasma lipid peroxides, malondialdehyde and viral load were measured at baseline and at 3 months. New or recurrent infections for the 6-month period after study entry were also recorded. RESULTS: The vitamin group (n = 26) had an increase in plasma concentrations of alpha-tocopherol (P < 0.0005) and vitamin C (P < 0.005) and a reduction in lipid peroxidation measured by breath pentane (P < 0.025), plasma lipid peroxides (P < 0.01) and malondialdehyde (P < 0.0005) when compared with controls (n = 23). There was also a trend towards a reduction in viral load (mean +/- SD changes over 3 months, -0.45 +/- 0.39 versus +0.50 +/- 0.40 log10 copies/ml; P = 0.1; 95% confidence interval, -0.21 to -2.14). The number of infections reported was nine in the vitamin group and seven in the placebo group. CONCLUSION: Supplements of vitamin E and C reduce oxidative stress in HIV and produce a trend towards a reduction in viral load. This is worthy of larger clinical trials, especially in HIV-infected persons who cannot afford new combination therapies.     

Protein kinase Cdelta-dependent induction of manganese superoxide dismutase gene expression by microtubule-active anticancer drugs

Bacterial lipopolysaccharide can induce manganese superoxide dismutase (MnSOD) gene expression in a variety of cells. Paclitaxel (taxol) shares many properties of lipopolysaccharide. Here we report that paclitaxel can induce MnSOD gene expression in human lung adenocarcinoma cell line A549 in a time- and dose-dependent manner. Additional anticancer drugs, vinblastine and vincristine, also induced MnSOD gene expression. We have shown previously (Das, K. C., and White, C. W. (1997) J. Biol. Chem. 272, 14914-14920) that these drugs can activate protein kinase C (PKC). The PKC agonists thymeleatoxin (0.5 microM) and 12-deoxyphorbol 13-phenylacetate 20-acetate (dPPA; 10 nM) potently induced MnSOD gene expression. Calphostin C and GF109203X, both specific inhibitors of PKC, each inhibited MnSOD gene expression by anticancer agents. Down-regulation of PKC by prolonged treatment with phorbol 12-myristate 13-acetate (PMA) also inhibited induction of MnSOD by anticancer drugs, indicating an important role of PKC in MnSOD signaling by these agents. Of 11 PKC isoenzymes, only PKCdelta translocated to the cell membrane after stimulation with anticancer drugs. By contrast, dPPA, PMA, and thymeleatoxin caused translocation of PKCalpha, betaI, delta, and mu isotypes. Anticancer drug-stimulated cells also had increased total PKC activity in membrane and cytosolic fractions. Thus, paclitaxel, vinblastine, and vincristine each specifically activate PKCdelta, whereas PMA, thymeleatoxin, and dPPA activate multiple isoenzymes. PKCdelta was the only isoform activated by each agent in both groups of compounds effective in MnSOD induction.     

The effect of expanding Medicaid prenatal services on birth outcomes

OBJECTIVES: Over 80% of US states have implemented expansions in prenatal services for Medicaid-enrolled women, including case management, nutritional and psychosocial counseling, health education, and home visiting. This study evaluates the effect of Washington State's expansion of such services on prenatal care use and low-birthweight rates. METHODS: The change in prenatal care use and low-birthweight rates among Washington's Medicaid-enrolled pregnant women before and after initiation of expanded prenatal services was compared with the change in these outcomes in Colorado, a control state. RESULTS: The percentage of expected prenatal visits completed increased significantly, from 84% to 87%, in both states. Washington's low-birthweight rate decreased (7.1% to 6.4%, P = .12), while Colorado's rate increased slightly (10.4% to 10.6%, P = .74). Washington's improvement was largely due to decreases in low-birthweight rates for medically high-risk women (18.0% to 13.7%, P = .01, for adults; 22.5% to 11.5%, P = .03, for teenagers), especially those with preexisting medical conditions. CONCLUSIONS: A statewide Medicaid-sponsored support service and case management program was associated with a decrease in the low-birthweight rate of medically high-risk women.     

Lyapunov-function-based design of fuzzy logic controllers and itsapplication on combining controllers

This paper presents the design of fuzzy logic controllers (FLCs) for nonlinear systems with guaranteed closed-loop stability and its application on combining controllers. The design is based on heuristic fuzzy rules. Although each rule in the FLC refers to a stable closed-loop subsystem, the overall system stability cannot be guaranteed when all these rules are applied together. In this paper, it is proved that if each subsystem is stable in the sense of Lyapunov (ISL) under a common Lyapunov function, the overall system is also stable ISL. Since no fuzzy plant model is involved, the number of subsystems generated is relatively small, and the common Lyapunov function can be found more easily. To probe further, an application of this design approach to an inverted pendulum system that combines a sliding-mode controller (SMC) and a state feedback controller (SFC) is reported. Each rule in this FLC has an SMC or an SFC in the consequent part. The role of the FLC is to schedule the final control under different antecedents. The stability of the whole system is guaranteed by the proposed design approach. More importantly, the controller thus designed can keep the advantages and remove the disadvantages of the two conventional controllers     

Segmental small bowel allograft--ischemic injury and regeneration

PURPOSE: Small bowel transplantation (SBT) is the ultimate treatment for intestinal failure. It remains unclear as to which intestinal segment is more suitable for use in segmental SBT. The current study aims to assess the susceptibility of various parts of small intestine to ischemia and reperfusion injury and their capacity for regeneration. METHODS: Thirty-two segments of pig jejunum and ileum were isolated with intact vascular pedicles that were clamped for periods varying from 1/2 to 8 hours. Biopsy specimens were taken immediately before clamp release and 20 minutes afterwards. All segments were anastomosed together before abdominal closure. Laparotomy was performed 24 hours later, and biopsy specimens were taken at all segments. All specimens were examined histologically by a pathologist. RESULTS: Evidence of injury was detected after 1.5 hours of ischemia at jejunum, but only after 5 hours at ileum. More severe injury was noted at the initial period on reperfusion, but there was no further deterioration at the later period. Complete reepithelialization occurred after 24 hours even where there had been total villous sloughing at reperfusion, but regeneration was impossible when the crypts had been damaged completely. CONCLUSIONS: Ileum, because it is more resistant to ischemia and reperfusion injury, may be preferred for segmental SBT. Regeneration of the bowel epithelium is fast, provided that the crypts are not damaged completely.     

Enhancement of the AMPLICOR enterovirus PCR test with a coprecipitant

The incorporation of a commercially available coprecipitant into the AMPLICOR enterovirus PCR test specimen preparation enhanced the sensitivity and reproducibility of this assay. Fifty-five previously tested archived cerebrospinal fluids (CSF) specimens were tested in a blind study in duplicate with and without Pellet Paint coprecipitant (Novagen, Inc., Madison, Wis.). Of these specimens, 26 had previously been determined to be positive and 29 had previously been determined to be negative. All previously positive CSF specimens were positive when Pellet Paint was used and only 18 were positive without Pellet Paint. No previously negative specimens were positive on repeat testing with or without Pellet Paint. The background signal was not affected by the addition of Pellet Paint. These data support the utility of a coprecipitant in minimizing false-negative results.     

Replication checkpoint requires phosphorylation of the phosphatase Cdc25 by Cds1 or Chk1

Checkpoints maintain the order and fidelity of events of the cell cycle by blocking mitosis in response to unreplicated or damaged DNA. In most species this is accomplished by preventing activation of the cell-division kinase Cdc2, which regulates entry into mitosis. The Chk1 kinase, an effector of the DNA-damage checkpoint, phosphorylates Cdc25, an activator of Cdc2. Phosphorylation of Cdc25 promotes its binding to 14-3-3 proteins, preventing it from activating Cdc2. Here we propose that a similar pathway is required for mitotic arrest in the presence of unreplicated DNA (that is, in the replication checkpoint) in fission yeast. We show by mutagenesis that Chk1 functions redundantly with the kinase Cds1 at the replication checkpoint and that both kinases phosphorylate Cdc25 on the same sites, which include serine residues at positions 99, 192 and 359. Mutation of these residues reduces binding of 14-3-3 proteins to Cdc25 in vitro and disrupts the replication checkpoint in vivo. We conclude that both Cds1 and Chk1 regulate the binding of Cdc25 to 14-3-3 proteins as part of the checkpoint response to unreplicated DNA.