Flow cytometric characterization of rat thymus cells in a radiation-dominated model of combined injury

Thymuses of rats that had been: a) gamma-irradiated [500 cGy whole-body radiation (R)], or b) thermally injured [20% BSA dorsal, scald burn (TI)], or c) combined injured [irradiation followed by burn (CI)] were studied for involution and recovery processes after sublethal treatments. The expression of surface antigens on thymic cells before and after injuries was evaluated using the monoclonal antibodies (mcAB) MRC OX4, MRC OX7, MRC OX8, W3/13 HLK, and W3/25 and flow cytometric analysis. Thymic cellularity decreased to less than 1% of normal (N), age-matched rats by 4 days after R or CI. Recovery reached 60% to 70% of N by 28 days post treatments. TI caused a biphasic thymic recovery pattern with nadirs of 40% of N on days 7 and 21. Recovery at day 28 was similar to that after R and CI. Expression of OX7, OX8, W3/13, and W3/25 antigens all reached nadirs of 40% of N by day 4 after R and CI. Recovery of antigen expression, except for W3/25, was near completion by day 7 after R and CI. Changes in antigen expression after TI were less pronounced for all mcAB tested. Decreases in labeling of thymocytes with the helper T-cell marker, W3/25, observed after TI, could not be correlated with elevated expressions of the suppressor/cytotoxic T-lymphocyte antigen, OX8. Variations in relative labeling of nonlymphoid thymic cells with OX4 (Ia-antigen) reflected the disappearance and recovery of radiosensitive lymphoid thymocytes. The similarity of results after R and CI demonstrate that the model of CI is 'radiation-dominated.' The addition of burn injury to radiation trauma had no synergistically damaging effect on the parameters studied.     

Prevalence of Chlamydia trachomatis and Mycoplasma pneumoniae in children with and without pharyngitis

The prevalence of Chlamydia trachomatis, Mycoplasma pneumoniae, group A beta-hemolytic streptococcus, and other treatable organisms was studied in children with and without pharyngitis. Children aged 2 to 12 years were evaluated between November 1985 and April 1986 in three family practice offices in the Salt Lake City area. Chlamydia trachomatis was not detected in the pharynx of any of the children studied. Mycoplasma pneumoniae was cultured from 5 percent of the 242 children studied, group A beta-hemolytic streptococcus from 30 percent, non-group A beta-hemolytic streptococcus from 5 percent, Hemophilus influenzae from 4 percent, and Staphylococcus aureus from 14 percent. The symptoms reported were not statistically associated with any organism isolated, and clinical signs of pharyngitis were associated only with the presence of group A beta-hemolytic streptococcus. Based on these results, management of pharyngitis in children should continue to be based on the detection and treatment of group A beta-hemolytic streptococcus.     

Medical removals of the Multiload IUD

In a follow-up evaluation of 3721 Multiload IUD users, the removal rate for medical reasons other than bleeding/pain was only 2.6 per 100 women at three years. Most of these removals were for reasons that appeared to be unrelated to IUD use. The removal rate for pelvic inflammatory disease was 0.3 per 100 woman years. Women were followed up for up to three years after removal of their IUDs. Among women with PID at least 70% of those who desired pregnancy subsequently became pregnant, a rate similar to that of women who had their IUDs electively removed to become pregnant. The study provides further data on the safety of intrauterine contraception.

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Resumen Durante el seguimiento de 3721 usuarias del DIU Multiload, la tasa de remociones por otras razones médicas que sangrado/dolor, fué de 2.6 por 100 mujeres en tres años. La mayoría de estas remociones fueron hechas por razones que parecen no estar relacionadas con el uso del DIU. La tasa de remociones por enfermedad inflamatoria pelviana fué de 0.3 por 100 años-mujer. Las mujeres tuvieron seguimiento hasta tres años después de la remoción de sus DIU. Entre las mujeres con enfermedad inflamatoria pelviana, al menos 70% de las que desearon un embarazo lo consiguieron; una tasa similar a la de mujeres que eligieron la remoción del DIU para quedar embarazadas. El estudio proporciona más información sobre la inocuidad de la anticoncepción intrauterina.

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Résumé Lors d'une évaluation de suivi effectuée sur 3721 utilisatrices de DIU Multiload, le taux de retrait pour des raisons médicales autres que des pertes sanguines/douleurs n'a atteint que 2,6 pour cent des femmes après trois ans. La plupart de ces retraits ont été pratiqués pour des raisons qui ne semblaient pas liées à l'utilisation du DIU. Le taux de retrait pour cause d'inflammation pelvienne s'est élevé à 0,3 pour cent femmes-an. Les femmes ont été suivies pendant des périodes allant jusqu'à trois ans après le retrait du DIU. Parmi les patientes qui avaient contracté une inflammation pelvienne, 70% au moins de celles qui souhaitaient une grossesse sont par la suite devenues enceintes; taux semblable à celui des femmes qui avaient choisi de ne plus porter leur DIU précisément pour avoir un enfant. Cette étude fournit des données supplémentaires sur la sécurité qu'apporte la contraception intrautérine.

     

Comparative dermal carcinogenesis of shale and petroleum-derived distillates

Ten test materials derived from petroleum or hydrotreated shale oils were applied 3 times/week for up to 105 weeks to the shaved skin of 25 male and 25 female C3H/HeN mice per group. Mineral oil and benzo(a) pyrene (0.15%) were control materials. Clinical observations were recorded during the study. At death, histopathologic examination was conducted on skin, internal organs and any gross lesions. Exposures to some materials were ended midway in the study due to severe irritation. Chronic toxicity of all materials was limited to inflammatory and degenerative skin changes. Significant increases over control incidence of skin tumors (squamous cell carcinoma and fibrosarcoma) occurred with both petroleum and shale-derived naphtha (21%, 50%), Jet A (26%, 28%), JP-4 (26%, 50%), and crude oils (84%, 54%). Severely hydrotreated shale oil and petroleum and shale-derived diesel distillates were not considered tumorigenic. Results indicate that toxicity of comparable petroleum and shale-derived fractions was qualitatively similar and confirm earlier findings that hydrotreating reduces or eliminates carcinogenicity of raw shale oil.     

Report of the Canadian Hypertension Society Consensus Conference: 2. Nonpharmacologic management and prevention of hypertensive disorders in pregnancy

OBJECTIVE: To provide Canadian physicians with comprehensive, evidence-based guidelines for the nonpharmacologic management and prevention of gestational hypertension and pre-existing hypertension during pregnancy. OPTIONS: Lifestyle modifications, dietary or nutrient interventions, plasma volume expansion and use of prostaglandin precursors or inhibitors. OUTCOMES: In gestational hypertension, prevention of complications and death related to either its occurrence (primary or secondary prevention) or its severity (tertiary prevention). In pre-existing hypertension, prevention of superimposed gestational hypertension and intrauterine growth retardation. EVIDENCE: Articles retrieved from the pregnancy and childbirth module of the Cochrane Database of Systematic Reviews; pertinent articles published from 1966 to 1996, retrieved through a MEDLINE search; and review of original randomized trials from 1942 to 1996. If evidence was unavailable, consensus was reached by the members of the consensus panel set up by the Canadian Hypertension Society. VALUES: High priority was given to prevention of adverse maternal and neonatal outcomes in pregnancies with established hypertension and in those at high risk of gestational hypertension through the provision of effective nonpharmacologic management. BENEFITS, HARMS AND COSTS: Reduction in rate of long-term hospital admissions among women with gestational hypertension, with establishment of safe home-care blood pressure monitoring and appropriate rest. Targeting prophylactic interventions in selected high-risk groups may avoid ineffective use in the general population. Cost was not considered. RECOMMENDATION: Nonpharmacologic management should be considered for pregnant women with a systolic blood pressure of 140-150 mm Hg or a diastolic pressure of 90-99 mm Hg, or both, measured in a clinical setting. A short-term hospital stay may be required for diagnosis and for ruling out severe gestational hypertension (preeclampsia). In the latter case, the only effective treatment is delivery. Palliative management, dependent on blood pressure, gestational age and presence of associated maternal and fetal risk factors, includes close supervision, limitation of activities and some bed rest. A normal diet without salt restriction is advised. Promising preventive interventions that may reduce the incidence of gestational hypertension, especially with proteinuria, include calcium supplementation (2 g/d), fish oil supplementation and low-dose acetylsalicylic acid therapy, particularly in women at high risk for early-onset gestational hypertension. Pre-existing hypertension should be managed the same way as before pregnancy. However, additional concerns are the effects on fetal well-being and the worsening of hypertension during the second half of pregnancy. There is, as yet, no treatment that will prevent exacerbation of the condition. VALIDATION: The guidelines share the principles in consensus reports from the US and Australia on the nonpharmacologic management of hypertension in pregnancy.