Differential effects of inhibitors of monoamine oxidase Types A and B on the adrenergic system of the rabbit iris.

Topical instillation of inhibitors of monoamine oxidase Types A and B into the rabbit eye, followed by the administration of a releaser of monoamines (Ro 4-1284), induces strong and sustained dilation of the iris. The mydriatic pattern differs markedly with A- and B-inhibitors and with the duration of the inhibitor treatment. The Type B inhibitor, deprenyl, prevents the degradation of exogenous 2-phenylethylamine and possibly of the endogenous amine X capable of releasing monoamines from a compartment less accessible to Ro-1284.     

Chemotherapy of autochthonous leukemias induced by 7,12-dimethylbenz(a)anthracene in long evans rats

Summary A total of 111 autochthonous (primary) acute rat leukemias of the diffuse-hepatic type which had been induced by 7,12-dimethylbenz(a)anthracene were treated with mono- and combination chemotherapy. The survival time of treated rats increased significantly compared to untreated controls. A combination of vincristine (VCR), adriamycin (ADR), and cytosine arabinoside (Ara-C) was superior to a combination of VCR and ADR as well as to a monotherapy with Cyclophosphamide, BCNU, VCR, ADR, and Ara-C.     

Mercury, food webs, and marine mammals: implications of diet and climate change for human health

We modeled the flow of methyl mercury, a toxic global pollutant, in the Faroe Islands marine ecosystem and compared average human methyl mercury exposure from consumption of pilot whale meat and fish (cod, Gadus morhua) with current tolerable weekly intake (TWI) levels. Under present conditions and climate change scenarios, methyl mercury increased in the ecosystem, translating into increased human exposure over time. However, we saw greater changes as a result of changing fishing mortalities. A large portion of the general human population exceed the TWI levels set by the World Health Organization [WHO; 1.6 microg/kg body weight (bw)], and they all exceed the reference dose (RfD) of 0.1 microg/kg bw/day set by the U.S. Environmental Protection Agency (EPA; equivalent to a TWI of 0.7 microg/kg bw). As a result of an independent study documenting that Faroese children exposed prenatally to methyl mercury had reduced cognitive abilities, pregnant women have decreased their intake of whale meat and were below the TWI levels set by the WHO and the U.S. EPA. Cod had approximately 95% lower methyl mercury concentrations than did pilot whale. Thus, the high and harmful levels of methyl mercury in the diet of Faroe Islanders are driven by whale meat consumption, and the increasing impact of climate change is likely to exacerbate this situation. Significantly, base inflow rates of mercury into the environment would need to be reduced by approximately 50% to ensure levels of intake below the WHO TWI levels, given current levels of whale consumption.     

Influence of ischemia on heart-rate variability in chronic hemodialysis patients

BACKGROUND: Sudden cardiac death occurring in patients with end-stage renal disease (ESRD) may be related to poor autonomic function with a significant decreased heart-rate variability (HRV). In addition, coronary artery disease has a high prevalence in this population and accounts for 50% of deaths. In the present study, relationships between HRV and myocardial ischemic abnormalities revealed by myocardial scintigraphy (MS) were evaluated in 32 chronic hemodialysis patients. METHODS: We prospectively studied 32 chronic hemodialysis patients. Each underwent MS and 24 h electrocardiography at baseline for analysis of time and frequency domain the day of dialysis. Three periods were analyzed: during dialysis session, the morning after (nondialytic period), and in a 24 h period. Patients were included in group 1 (seven women, 11 men; mean age: 62+/-19 years) when MS revealed no ischemia, whereas patients were included in group 2 (seven women, seven men; mean age: 63.1+/-20 years) when MS revealed ischemic lesions. RESULTS: A student+/-test revealed that during the nondialytic period, two important markers of HRV, percentage of delta RR>50 ms (pNN50) (4.5+/-4.04 in group 1 versus 1.7+/-1.4 in group 2), and root mean square of delta RR (rMSSD) (27.7+/-13.4 versus 19.7+/-6.8) were significantly reduced in group 2 compared with values in group 1. No significant difference appears between the two groups for standard deviation of normal to normal intervals (SDNN), mean heart rate, and spectral analysis. CONCLUSION: Patients with ESRD and myocardial ischemia revealed by MS have reduced parasympathetic activity during the nondialytic period. Correlations between parameters of HRV and ischemic lesions revealed by MS have been shown for the first time.     

Chemotherapy of meningeal leukemia in rats (L5222)

An experimental model of meningeal leukemia in syngenic BDIX rats was developed by intracerebral inoculation of leukemic cells from the transplantable acute leukemia L5222. Using the bioassay technic, the proliferation of the L5222 in the central nervous system and in the body was studied. According to the number of leukemic cells in the meninges and brain, an early, advanced, and preterminal stage of meningeal leukemia can be distinguished. Chemotherapeutic studies with BCNU and cyclophosphamide yielded cures in a high percentage of cases when treatment began at an early stage of meningeal leukemia. In advanced and preterminal stages, only BCNU showed a large number of cures. This model for meningeal leukemia was used as a screening system for new nitrosoureas. Preliminary results on chemotherapeutic activity showed a marked superiority of the water-soluble 1-(2-hydroxyethyl)-3-(2-chloroethyl)-3-nitrosourea in comparison to BCNU.     

Childhood idiopathic thrombocytopenic purpura in the Nordic countries: epidemiology and predictors of chronic disease

AIM: To describe the epidemiology of idiopathic thrombocytopenic purpura (ITP) in the Nordic countries, to define clinical subgroups and to investigate factors predicting chronic disease. METHODS: A prospective registration was done from 1998 to 2000, including all children with newly diagnosed ITP aged 0-14 y and at least one platelet count <30 x 10(9)/l. RESULTS: 506 children were registered and 423 followed for 6 mo. The incidence was 4.8/10(5) per year. Most children were aged 0-7 y (78%), with a predominance of boys, while patients aged 8-14 y had equal representation of the two sexes. There were seasonal variations determined by variations in postinfectious cases with sudden onset. The platelet count was <10 x 10(9)/l in 58%, but bleeding manifestations were mild or moderate in 97%. The insidious form (symptoms for more than 2 wk) was more frequent in older children and girls, showed little seasonal variation, had milder manifestations and ran a chronic course in more than half the cases. Intracranial haemorrhages did not occur in the first 6 mo after diagnosis. Chronic ITP developed in 25%. The strongest predictor of chronic disease was insidious onset of symptoms (OR 5.97). CONCLUSION: In the Nordic countries, ITP mainly affects children aged 0-7 y, with a winter bulk of postinfectious cases superimposed on a steady occurrence of non-infectious cases. Clinically, it may be useful to distinguish between children with sudden versus insidious onset of symptoms rather than between different age groups.     

Acceptability and feasibility of continuous diaphragm use among sex workers in Madagascar

OBJECTIVES: The diaphragm, a woman controlled, reusable contraceptive device, might prevent some sexually transmitted infections (STIs). We assessed the acceptability and feasibility of use of silicone Wide-Seal Arcing Diaphragms (Milex Products, Chicago, IL, USA) by sex workers in Madagascar. METHODS: Over 8 weeks, we evaluated method acceptability by examining patterns of and problems with women's diaphragm use. We also evaluated several measures of study feasibility, including recruitment and follow up methods. RESULTS: 91 women from three cities (Antananarivo, Tamatave, and Mahajanga) participated, and 87 (96%) completed follow up. At enrolment, participants reported a median of six sex acts with five clients in the previous week. During the follow up period, participants reported a median of three sex acts with three clients during the previous 2 days, and self reported continuous diaphragm use during the previous day increased from 87% to 93%. Seven women became pregnant (incidence 53 pregnancies per 100 woman years). Self reported use of male condoms and diaphragms was fairly constant over the study period: women reported condom use in 61% to 70% of acts and diaphragms in 95% to 97% of acts. The number of participants reporting diaphragm problems decreased from 15 (16%) at the first visit to six (7%) at the final visit. 20 women (22%) needed replacement devices during follow up because their original diaphragms were lost, were the wrong size, or became seriously damaged. CONCLUSIONS: Given the high use and steady decrease in reported problems during the study, we believe diaphragms are acceptable and feasible in this resource poor, low education sex worker population.