In vitro anti-trichomonad effectiveness of a gossypol-metronidazol blend

With the aid of the Basic Sequential Analytical Simplex Method the in vitro anti-trichomonad effectiveness of several metronidazole/gossypol blends was determined. While the combination that produced 50% of growth inhibition on trichomonad cultures (IC(50)) contained 15.1 muM gossypol and 0.087 muM metronidazole, the IC(50) of metronidazole and gossypol tested separately was 38.08 muM and 0.195 muM, respectively. Thus, the IC(50) of mixed gossypol and metronidazole was, respectively 60.34 and 55.4% lower than that of each separated drug. Whereas metronidazole is usually administered orally, gossypol, used as spermicide, is formulated as pessary. In such conditions the absorption of metronidazole is very efficient while that of gossypol is strikingly poor. The above suggest that a gossypol-metronidazole anti-trichomoniasis therapeutic scheme could be as effective as metronidazole alone, but less toxic.     

Relationship between Cigarette Dose and Perceived Risk of Lung Cancer

BACKGROUND: Most people are aware that smoking cigarettes increases the risk of ill health, in particular of lung cancer. The precise way in which they relate amount of exposure to smoke and level of health risk has not, however, been determined. METHODS: A convenience sample of 155 French adolescents and adults ages 15 to 75 rated the risk of "smoker's cancer"--the popular term for lung cancer--in 24 scenarios depicting eight levels of daily cigarette consumption of three concentrations of nicotine. The data were analyzed according to functional measurement methodology to ascertain the forms of the relationship between exposure and perceived risk. RESULTS: All subjects perceived that the risk of smoker's cancer increased as smoking increased. Yet at high levels of consumption, additional cigarettes were generally judged to result in decreasing increments of risk, regardless of the nicotine content of the cigarettes and the sex and smoking status of the participants. Adolescents, however, were more likely than adults to perceive a linear, rather than a negatively accelerated, relationship. CONCLUSIONS: The actual form of the relationship between the dose of cigarette smoke and risk of lung cancer is either linear or positively accelerated. Public health educators and physicians should be aware that, at least in France, many people, particularly adults, incorrectly perceive this relationship as negatively accelerated.     

Electroconvulsive Therapy in Adolescents

Because of the limited number of case reports on the use of electroconvulsive therapy (ECT) in adolescent psychiatric patients, we retrospectively reviewed the medical records of 20 young patients who underwent ECT. They constituted all the patients 相似文献   

How do normal subjects learn a simple adaptative task: How and why do paranoid schizophrenic patients fail?

Summary The authors studied the behavior of normal subjects and paranoid schizophrenic patients in a simple problem-solving situation. The schizophrenics were divided into two sample groups, one of individuals under treatment and the other of individuals not under treatment.The learning process involved in this problem-solving situation is very similar to an instrumental conditioning, and can be understood by means of the following assumptions: (1) the subjects use decision functions in reacting to the stimuli, although they may be not fully aware of this; (2) learning is the result of successive transformations of these decisions in the course of time; (3) the changes have specific probabilities and are related to (a) those responses which are made to the latest stimuli, and (b) a differential probability for decision functions which were effective, or only interrupted painful reinforcement, or were completely ineffective.In schizophrenics further factors of importance were (1) an inertia factor and (2) the rigidly continued use of unsuccessful or only partially successful decision criteria.The authors used a systems theory based on Galois field theory and a calculus of operators specifying three groups of subjects. A computer program based on these hypotheses was tested in a simulation experiment.The statistical evaluation of the results showed a congruence between the theoretical approach and the experimental data.This work was carried out with financial support from the Institute de Alta Cultura, Lisbon, between 1970 and 1974     

Acquired hyperoxaluria and haematuria in children

Two children with extensive ileal resection are reported. They developed gross haematuria of non-glomerular origin, without stones or nephrocalcinosis. Previous reports indicate that acquired hyperoxaluria is common in children with a variety of intestinal disorders. Our patients had hyperoxaluria. We think that hyperoxaluria may be the cause of haematuria through a pathogenetic mechanism similar to the one ascribed to haematuria secondary to hypercalciuria and hyperuricosuria.     

Effects of Sex,Handedness, Stimulus and Visual Field on “Mental Rotation”

Shepard's mental rotation paradigm (e.g. Shepard and Metzler, 1971) was modified to allow tachistoscopic presentation of stimuli at varying angles of orientation (0° to 180°) in the right and left visual fields. Thirty male and thirty female subjects divided into three handedness groups (right-handers, non-familial and familial left-handers) judged whether a stimulus was a standard form or its mirror image. In general response times for correct judgements (RT_c) increased monotonically as a function of angle of orientation though the curves tended to be negatively accelerated rather than linear. Right-handers showed a slower rate of increase in RT_c as a function of angle than either left-handed group. Mean RT_c and the rate of increase in RT_c were equivalent for the two sexes and for the two visual fields. Both mean RT_cs and on the rate of increase in RT_c varied as a function of the stimulus.Error rates also increased monotonically as a function of angle of orientation. No sex or handedness differences in error rates were found. However, errors increased significantly less rapidly when stimuli were presented in the left visual field. It is argued that right hemisphere specialization for spatial processing minimizes the rate of increase in errors.The present failure to find sex differences may be of interest and it is argued that rapid presentation of stimuli results in subjects setting maximum and minimun response times. Within this relatively restricted “bandwith” of response times males and females may perform spatial tasks equally efficiently. Some confirmation for this hypothesis vs. an alternative based upon differences in hemispheric organization was found in a second experiment.     

Effect of carbon disulphide intoxication on fecal excretion of end products of cholesterol metabolism

Summary The aim of this study was to compare the time course of ¹⁴C-steroid excretion following administration of ¹⁴C-cholesterol in normal and CS₂intoxicated rats. The excretion of steroid with the feces was evaluated in the normal and CS₂ intoxicated rats at the end of 7 month exposure to CS₂. The results of the experiment indicated that in rats exposed to CS₂ excretion of ¹⁴C-steroid is lower. It was due to a reduced excretion of ¹⁴C-bile acid fraction while at the same time the share of sterol + rose. On the basis of our former results which excluded the influence of CS₂ on absorption of cholesterol and indicated its effect on cholesterol synthesis it was revealed in this experiment that intoxication with CS₂ also inhibits cholesterol degradation. Disturbances of both processes can be essential for accumulation of cholesterol in blood of animals intoxicated with CS₂.This investigation has been carried out under the Polish-American agreement No. 05-008-2 with the Occupational Health Program, U.S. Public Health Service     

Specific language impairment in families: evidence for co-occurrence with reading impairments.

Two family aggregation studies report the occurrence and co-occurrence of oral language impairments (LIs) and reading impairments (RIs). Study 1 examined the occurrence (rate) of LI and RI in children with specific language impairment (SLI probands), a matched control group, and all nuclear family members. Study 2 included a larger sample of SLI probands, as well as their nuclear and extended family members. Probands and their family members who met specific criteria were classified as language and/or reading impaired based on current testing. In Study 1, the rates of LI and RI for nuclear family members (excluding probands) were significantly higher than those for control family members. In the SLI families, affected family members were more likely to have both LI and RI than either impairment alone. In Study 2, 68% of the SLI probands also met the diagnostic classification for RI. The language and RI rates for the other family members, excluding probands, were 25% and 23% respectively, with a high degree of co-occurrence of LI and RI (46%) in affected individuals. Significant sex ratio differences were found across generations in the families of SLI probands. There were more male than female offspring in these families, and more males than females were found to have both LIs and RIs. Results demonstrate that when LIs occur within families of SLI probands, these impairments generally co-occur with RIs. Our data are also consistent with prior findings that males show impairments more often than females.     

Microcystin production by Radiocystis fernandoi (Chroococcales, Cyanobacteria) isolated from a drinking water reservoir in the city of Belém, PA, Brazilian Amazonia region.

During the monitoring of toxic cyanobacteria in the Utinga Reservoir, which is the main drinking water supply for the city of Belém, PA, Brazil, a Radiocystis fernandoi strain (SPC714) was isolated. This non-axenic strain was submitted to a toxicity bioassay with mice and microcystin production analyzed by HPLC-DAD. The species was identified based on cultured and natural preserved material. Morphometric, developmental and reproductive characteristics were analyzed. The strain was cultured in liquid ASM-1 medium, at 25+/-1 degrees C, at an incident irradiance of 20 micromol photon m(-2)s(-1) and constant aeration. At the end of the exponential growth phase, cells were lyophilized and submitted to toxicity tests. The strain showed high toxicity to mice, by intraperitoneal route, with an approximate LD100 of 60 mg kg(-1) of body weight, producing characteristic symptoms of hepatotoxicity. Analyses performed by HPLC-DAD confirmed the production of microcystins, in a concentration of 3.83 microg mg(-1) of lyophilized cells. This is the first reference related to the toxicity of the genus Radiocystis.