The central actions of lidocaine and a pesticide, chlordimeform

The injection of 300–1000 μg of lidocaine or chlordimeform (CDM) into the lateral ventricles of rats lightly anaesthetized with urethane produced similar dose-dependent pressor (or depressor) responses. Stimulation of the dorsal raphe nucleus caused suppression of the spontaneous EEG recorded from bipolar electrodes implanted in the amygdala. Intraventricular lidocaine and CDM blocked the raphe-mediated suppression of the amygdala EEG activity.

Higher doses (3–4 mg) of intraventricular lidocaine or CDM resulted in clonic limb movements, spikes in the amygdala EEG and blood pressure oscillation. All seizure manifestations could be blocked by intense raphe stimulation or by intravenous diazepam (1 mg/kg).

These studies indicate a central origin for the secondary pressor response that is observed with higher intravenous doses (10–50 mg/kg) of lidocaine or CDM.     

The sensitivity of human bone marrow granulocyte/monocyte precursor cells to phenylbutazone,oxyphenbutazone and gamma-hydroxyphenylbutazone in vitro, with observations on the bone marrow colony formation in phenylbutazone-induced granulocytopoenia

The inhibitory actions of phenylbutazone, oxyphenbutazone and γ-hydroxyphenylbutazone on the growth of human bone marrow granulocyte/monocyte colonies in vitro have been compared. Oxyphenbutazone is more toxic than phenylbutazone in this system, γ-hydroxyphenylbutazone is inhibitory over a wider concentration-range than either phenylbutazone or oxyphenbutazone, but has about the same inhibitory potency as phenylbutazone at concentrations corresponding to the peak plasma concentrations during treatment. Three patients who had recovered from phenylbutazone-induced bone marrow depression with neutropoenia were studied. The proliferative capacity of the bone marrow from all three patients was reduced as judged by the measured formation of granulocyte/monocyte colonies in vitro. The sensitivity of the patients' bone marrow to inhibition by either phenylbutazone (two patients) or by oxyphenbutazone (three patients) was compared with that of normal subjects' bone marrow. Increased sensitivity to phenylbutazone was demonstrated in the patients. The difference between the patients' and normal subjects' marrow with respect to their sensitivity to oxyphenbutazone was insignificant. The present results are compared with the results of similar studies with other drugs which produce neutropoenia. It is concluded that they are not inconsistent with the suggestion that phenylbutazone-induced neutropoenia is due to an underlying marrow abnormality.     

Exposure to cigarette smoking and children's growth

An analysis of data from 5903 children from a study of primary schools in England and Scotland in 1982 showed that the number of cigarettes smoked by the parents at home was significantly associated with the attained height of their children. This relation was statistically significant after allowing for parents' height, child's birthweight, mother's smoking during pregnancy, overcrowding and number of older siblings. Number of cigarettes smoked at home was more strongly related to height than number of cigarettes smoked by the mother during pregnancy. The results suggest that passive smoking may have an effect on the height of a child independent of genetic factors, the social environment and mother's smoking in pregnancy. Whether this is a direct effect of parents' smoking on the child's growth remains unclear.     

Ultrasound diagnosis of fetal genitourinary tract anomalies

Specific diagnoses of fetal genitourinary anomalies can be made with current high resolution ultrasound. Accurate diagnosis is essential if fetal intervention is contemplated.     

The validity of reported parental height in inner city areas in England

The validity of self-reported height was assessed in a sample of Afro-Caribbean, Asian and Caucasian parents. Asian mothers overestimated their height (p less than 0.01) and Caucasian mothers overestimated that of their child's father. The standard deviations of the differences between reported and measured height, with the exception of Caucasian mothers, were large (between 4.33 cm and 11.18 cm). It is concluded that self-reported height from subjects living in inner city areas in Britain should be interpreted with great caution.     

Middle Ear Pressure Variation: Effect of Nitrous Oxide

Previous studies examining middle ear pressure changes due to inhalant anesthesia, including nitrous oxide, have cited equivocal results. An investigation was performed to closely monitor changes in middle ear pressure during middle ear surgery. Baseline tympanometry was performed before anesthesia, and middle ear pressure was then documented in 1-min time intervals. A total of 97 subjects were studied; 51 received nitrous oxide and halothane, and 46 received halothane alone. Results indicate that nitrous oxide causes significantly greater pressure fluctuations than halothane alone. There were no effects for time of surgery, type of fluid, or baseline. Pressure fluctuation was attributed to eustachian tube function. Case studies are presented to demonstrate subject variability, and suggestions for validation study procedures are presented.     

Growth status and the risk of contracting primary tuberculosis.

A case of open tuberculous infection in a member of staff at a primary school resulted in an outbreak in which nearly a quarter of the children in the school contracted a primary infection. The growth status of these children was compared with that in the non-infected children before the outbreak and on two occasions after the outbreak. The children with tuberculous infection were taller and fatter than the controls before and after the outbreak but differences were not always statistically significant. Among children with a good nutritional status the thin and small child is at no greater risk of contracting primary tuberculous infection than other children.