Detection of HTLV-II in breastmilk of HTLV-II infected mothers.
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Biomedical subjects
Publications and source records attributed to T Woods.
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The object of the paper is to provide the basis to decide whether testing for drug use should be used, taking into consideration individual and social benefits and costs that the results of the tests could originate. In the analysis, special attention is paid to the fact that the actual costs of the tests themselves are not the most important elements of the social costs of a testing program. The most important costs are those generated by the defective results of the tests. They can provide false positive results, meaning that a nonuser is identified as a user, or false negative results in which a user is not identified as such. Social costs of the false positive results range from lowered worker morale to legal suits, while the false negative results eliminate any benefit that the identification of drug users could have. Combining all these elements, Correa and Woods specify a mathematical procedure as a decision tool to be used for determining whether a testing program should be implemented in specific industries or groups of industries. A complete implementation of the model is not carried out due to the lack of the required statistical information. However, preliminary trials showed that the conceptual and mathematical framework is operational, and that the model prepared could be used as a guideline for collecting the most appropriate data for decision making.
General guidelines are presented for the use of cluster-sample surveys for health surveys in developing countries. The emphasis is on methods which can be used by practitioners with little statistical expertise and no background in sampling. A simple self-weighting design is used, based on that used by the World Health Organization's Expanded Programme on Immunization (EPI). Topics covered include sample design, methods of random selection of areas and households, sample-size calculation and the estimation of proportions, ratios and means with standard errors appropriate to the design. Extensions are discussed, including stratification and multiple stages of selection. Particular attention is paid to allowing for the structure of the survey in estimating sample size, using the design effect and the rate of homogeneity. Guidance is given on possible values for these parameters. A spreadsheet is included for the calculation of standard errors.
Anatomic distances along retroperitoneal, inguinal, and infrainguinal segments of the vas deferens were measured in 14 formalin fixed cadavers and in 15 recently postmortem males. There were no significant differences in segment lengths between the two groups nor between the right and left vasa. Data from the recent postmortem group reveals a mean length of 5.83 +/- .65 cm to be gained from retroperitoneal mobilization of the vas deferens. This information is important to surgical decisions in cases of microsurgical repair of obstructive azoospermia resulting from damage to the inguinal segment of the vas deferens. Data on other vasal segment lengths is beneficial for planning repair in other complex cases of obstructive azoospermia as well.
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Resistance to Adriamycin (ADR) is frequently dependent upon enhanced efflux associated with the expression of the MDR1-encoded P membrane glycoprotein. Since enhanced expression of the MDR1 gene in ADR-resistant cells may be the result of spontaneous genetic mutation or amplification, it is presumed to be relatively stable and unalterable. Yet, reducing ADR efflux could increase sensitivity, and has been attempted using calcium channel blockers and other drugs. However, since the tumor cell microenvironment varies with respect to pH because of differences in vascularization, oxygenation, and metabolite clearance, the possibility exists that these factors could influence drug transport and the critical biochemical pathways which determine cytotoxicity, even in resistant cells. Using flow cytometric analysis of ADR fluorescence, the influx and efflux of 10 microM ADR dissolved in MES buffer (pH 6.5) and 4-(2-hydroxyethylene)-1-piperazineethanesulfonic acid buffer (pH 7.5 and 8.5) was measured in sensitive P388 and resistant P388/R84 cells in vitro. Substantially enhanced uptake of ADR was detected at alkaline pH in both cell populations, while the proportion of ADR-positive cells and the level of ADR uptake was decreased at lower pH. Acidification reduced ADR efflux, whereas alkalinization increased efflux when the uptake pH was 6.5 or 7.5. At uptake pH 8.5, the pH of the external buffer had little effect, even in resistant cells. In resistant cells in an alkaline microenvironment, ADR transport and retention were superior to that observed in sensitive cells in an acidic microenvironment. No differences were observed in ADR transport when the transmembrane pH gradient was equilibrated. These observations are especially relevant to the effect of ADR on tumor cell subpopulations that are acidic, and in which drug diffusion is inefficient. Efforts to alkalinize tumor cells prior to ADR therapy might reduce ADR resistance, even of genetic origin.
Relatively nonmyelotoxic drugs and drug combinations were investigated for their ability to eliminate malignant cells from human bone marrow. In vitro 90% inhibitory concentration (IC90) doses were established on granulocyte macrophage colony-forming units (GM-CFU) in culture of bone marrow by using the GM-CFU assay for the following drugs: 4-hydroperoxycyclophosphamide (4-HC), Adriamycin, L-asparaginase, bleomycin, hydrocortisone, VP-16, spirogermanium, Taxol, and vincristine. The leukemic cell kill efficiency of these drugs at IC90 doses was compared with that of 4-HC on acute lymphoid leukemia (ALL) cell lines by using the limiting-dilution assay. Under these conditions, no single drug was superior to 4-HC. To increase the in vitro effect in leukemic cell kill, combinations of vincristine with hydrocortisone, Adriamycin, VP-16, and 4-HC were investigated. Vincristine at 1 to 5 micrograms/mL increased the marrow cytotoxicity of hydrocortisone, Adriamycin, and VP-16, but it was protective (subadditive) with 4-HC. Vincristine and 4-HC in combination was additive to supraadditive on ALL cell lines, increased the leukemic cell kill by one to two logs above 4-HC alone at IC90 doses (P less than .05), and was not affected by the addition of excess marrow cells. The recommended doses for chemopurging in clinical studies are vincristine, 1 to 5 micrograms/mL, plus 4-HC, 5 micrograms/mL.
As part of an ongoing investigation into nosocomial Legionella infections at Stanford University Medical Center (SUMC), we applied the technique of restriction endonuclease analysis (REA) to determine strain differences among three species, including Legionella pneumophila, Legionella dumoffii, and Legionella micdadei. A total of 26 human and environmental water isolates from SUMC were selected for REA and compared with control strains that were not epidemiologically linked to SUMC. REA results were compared with results of alloenzyme typing, typing by monoclonal antibodies, and plasmid fingerprinting in all but L. micdadei strains. REA and alloenzyme typing showed that SUMC patient isolates were derived from distinct strains of three species. L. pneumophila strains from SUMC patients were genotypically identical to those isolated from potable water. REA was especially useful in proving that SUMC L. dumoffii patient isolates were derived from a single strain and that patients may have been exposed to a common source(s). REA typing correlated well with alloenzyme typing. These methods complement serologic typing of L. pneumophila and provide discriminating capability between strains of other Legionella species such as L. dumoffii, for which serologic types have not been identified. In addition, REA typing is somewhat easier to perform than alloenzyme typing and can be done in clinical laboratories.
Analgesic effect, labor outcome, safety and consumer satisfaction were compared in 170 primigravid women; 50 using TENS initially for pain relief, 20 using entonox, 50 pethidine + promazine and 50 lumbar epidural. 88% choosing epidural related it fully effective. 90% using entonox, 96% using TENS and 54% given pethidine + promazine found partial relief. 82% of patients given TENS and 80% given pethidine + promazine required additional analgesia. This was also needed by one of the 20 patients choosing entonox. Women using entonox alone had the shortest labors and women using lumbar epidural, the longest. Operative delivery was significantly more common in women receiving lumbar epidural. No significant inter-group differences were noted in cord pH or Apgar scores. Parturients and midwives both gave high consumer satisfaction ratings to all methods--except for pethidine + promazine, whose use must therefore be questioned. The analgesic efficacy of lumbar epidural outweighs any possible side effects. Entonox appears suited to those able to cope with the earlier part of labor, drug-free. Realization of the potential of TENS requires the design of machines specifically to cope with the quality of the pain of labor.
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The analgesic effects of transcutaneous electrical nerve stimulation (TENS) in labour and effects on outcome were investigated in a double-blind TENS/TENS placebo controlled trial in 100 primigravidae and 50 women in their third labour. There were no differences between the TENS and the TENS placebo users in terms of pain concept or relief, and only 12 and 13% of primigravidae and 48 and 39% of the para 2 women completed labour without requiring other analgesia in their respective groups. The primigravidae who used either TENS or TENS placebo alone had shorter labours than those who required further analgesia. Although the outcome of labour for mother and infant were similar in the two groups, there was a higher operative delivery rate in women who also had epidural analgesia. There were highly significant differences between the TENS and the TENS placebo users in terms of favourable and unfavourable comments by the mothers and the midwives at 1 and 24 h after delivery. The evident consumer satisfaction for TENS suggests TENS has a part to play in analgesia in labour but the equivocal findings in terms of factors associated with pain relief points to the need for apparatus more specifically designed to cope with the special characteristics of the pain of labour.
BKS-2 is an immature B cell lymphoma that undergoes apoptotic cell death when signaled via its surface IgM receptor. To study the signaling components of surface IgM mediated apoptosis in B lymphoma cells, we generated mutants of BKS-2 that were resistant to anti-IgM induced apoptosis. One mutant cell line, 1.B5, did not undergo apoptotic cell death upon treatment with anti-IgM antibodies and also did not exhibit elevation of intracellular Ca2+ in response to cross-linking of surface IgM. This appeared to be due to a defect in protein tyrosine kinase (PTK) activity since fewer proteins were tyrosine phosphorylated in the mutant cells stimulated with anti-IgM when compared to wild type BKS-2. Subsequently, we showed that protein tyrosine kinases lyn and blk were inducibly tyrosine phosphorylated in the wild type BKS-2 but not in 1.B5 mutant cells in response to anti-IgM. Also the kinase activity of lyn was elevated in the wild type but not in mutant cells upon triggering through surface IgM. Furthermore, tyrosine phosphorylation of CD19, a known substrate of lyn, was inducible in anti-IgM stimulated BKS-2 cells but severely reduced in 1.B5 cells. In contrast, kinase activity of another src kinase, blk, was increased on anti-IgM stimulation in both wild type and mutant cells. Surprisingly, syk, a non-src protein tyrosine kinase important for surface IgM mediated signaling, was tyrosine phosphorylated in the lyn deficient mutant cells as well as in the wild type BKS-2 cells. Furthermore, anti-IgM induced increase in kinase activity of syk was similar in the mutant and wild type cells. Thus, in contrast to other studies that propose syk to be a downstream target of src family kinases, syk may act upstream of lyn in immature B cells. Consistent with a functional syk, its target, phospholipase gamma2 (PLC-gamma2) was normally tyrosine phosphorylated in mutant cells.