Maternal and fetal effects of heroin addiction during pregnancy

Heroin addiction during pregnancy has been reported to be associated with adverse maternal and perinatal effects. In a study of a large obstetric service in Dallas, pregnancy outcome and health status of infants born to 24 heroin addicts were compared to those in a group of 100 unexposed women and their infants. Women who used heroin during pregnancy tended to use other substances (tobacco, alcohol, cocaine) more often than did controls. The frequency of preterm birth was increased significantly in women who abused heroin during pregnancy. Sexually transmitted diseases were not increased in frequency in pregnant heroin addicts as compared to women who did not use heroin during pregnancy. Heroin addicts had infants who were significantly shorter and lighter in weight than did controls. No significant differences in head circumference or frequency of congenital anomalies were observed.     

Visual acuity: Its relation to the form sense and the application of this relationship to medicolegal problems

Vision is a light and form sense. From the ability of the eye to discriminate detail of form is evolved the function of resolving power.The problem in medicolegal cases is the determination of the percentage loss of functional values. To determine these percentage functional disabilities, the relation between visual acuities and the associated functional losses must be established on a mathematical basis.The term “visual acuity” does not include the concept of function. Acuity notations are not fractions of vision nor are they fractional equivalents of resolving power.Comparing the successive gradations of acuity notations in the geometrical progression of Green and assuming that acuity notations express fractional ability of the form sense, it is shown that the better the acuity the poorer is functional ability—when vision is good it has relatively poor resolving power. This disproves the assumption.A method for computing the functional and proportionate value for acuity notations has been established. By this method each equal increase in the visual angle reduces visual resolving power (efficiency) by the same percentage.By application of this method to the medicolegal problem of evaluating visual disabilities, for identical degrees of damage to function identical percentage losses are established.     

Mycology quality assessment: United Kingdom national scheme.

A mycology quality assessment scheme introduced in 1986 was assessed: 289 laboratories participated in the scheme, and six distributions, each containing four specimens, were made. Levels of performance varied considerably among participating laboratories: performance was highest with the commoner organisms distributed, but some laboratories, encouragingly, achieved a consistently high level of species identification. A questionnaire distributed to participants showed that a wide range of methods are commonly used, some of which are contrary to good practice. As the scheme continues, selection of organisms considered to be relevant and of use to participants will become difficult.     

A study of the effects of frequency of probe data collection and graph characteristics on teachers' visual analysis

Teachers often rely on visual analysis of graphed student performance data to evaluate progress and make program decisions. However, because collecting data can be time consuming and interfere with instruction, teachers would like to know how much data is necessary to make reliable judgments. To investigate the effect of frequency of data collection on teachers' judgments and decisions, this study addressed the question of whether teachers' judgments differ according to frequency of data collection, whether teachers' judgments differ according to type of trend, and whether teachers' judgments based on different types of graphs vary with frequency of data collection. A set of 16 graphs of actual student performance data was analyzed by 59 teachers of students with moderate to profound handicaps. The data were analyzed by a two-factor repeated measures design, and results indicated that when asked to evaluate student performance, teachers' judgments tended to be consistent and accurate when the graphed data represented continuous and systematic improvement in performance. However, when the data represented a decrease in performance, no change, or highly variable performance, judgments tended to differ by frequency. When asked to make program recommendations, teachers' judgments tended to differ by frequency for all types of trends.     

Anaesthesia and postoperative pain management for bilateral lung volume reduction surgery.

Bilateral lung volume reduction surgery was introduced into Australia in 1995 for treatment of selected patients with emphysema. We present our experience of the anaesthetic management of our first 55 cases and describe factors associated with outcome. There were four postoperative deaths (7%). Mean (SD) total operation time was 231 (72) minutes. Median intensive care unit (ICU) stay was 26 hours. There was a significant improvement in postoperative lung function (FEV1, VC, 6-minute walk test, all P < 0.001). Eight patients (15%) required reintubation for respiratory failure; three of these patients subsequently died. With multivariate analysis, total operation time was the only significant predictor of length of ICU stay R2 = 0.25, P = 0.001), which itself was the only significant predictor of hospital stay duration (R2 = 0.36, P < 0.001).     

Acute toxicity tests using rotifers : IV. Effects of cyst age, temperature, and salinity on the sensitivity of Brachionus calyciflorus

Several aspects of the response to toxicants using a standardized toxicity test with the freshwater rotifer Brachionus calyciflorus are described. Test animals are obtained by hatching cysts which produce animals of similar age and physiological condition. The acute toxicity of 28 compounds is described with 24-hr LC₅₀'s. The LC₅₀'s span five orders of magnitude, from silver at 0.008 mg · liter⁻¹ to benzene at more than 1000 mg · liter⁻¹. Control mortality in 84 tests averaged 2% with a standard deviation of 3%, indicating very consistent test sensitivity. Only once in 84 trials did a test fail because of excessive control mortality, yielding a failure rate of 1.2%. Cyst age from 0 to 18 months had no effect on the sensitivity of neonates to reference toxicants. Both high and low temperatures increased rotifer sensitivity to reference toxicants. Copper sensitivity was greater at 10, 25, and 30°C compared with results at 20°C. Likewise, sodium pentachlorophenol toxicity was greater at 10 and 30°C compared with results at 20°C. Survivorship curves at 25°C of neonates under control conditions indicated that mortality begins at about 30 hr. This places a practical limit on toxicant exposure for the assay of 24 hr. B. calyciflorus cysts hatch at salinities up to 5 ppt and acute toxicity tests using pentachlorophenol at this salinity yielded LC₅₀'s about one-half those of standard freshwater. B. calyciflorus is preferred over Brachionus plicatilis for toxicity tests in salinities up to 5 ppt because it is consistently more sensitive.     

Febrile seizure. Caring for patients--and their parents

Management of febrile seizure involves diagnosis and treatment of the underlying cause and assessment of risk factors for recurrence. What should physicians tell anxious parents about this frightening occurrence? Is prophylaxis with anticonvulsant agents appropriate? The authors address these questions and discuss the changing approach to management of febrile seizure.