Nitroreductases and glutathione transferases that act on 4-nitroquinoline 1-oxide and their differential induction by butylated hydroxyanisole in mice.

These studies concern the initial steps in 4-nitroquinoline 1-oxide (4NQO) metabolism in relation to mechanisms of anticarcinogenesis. Butylated hydroxyanisole (BHA) administration by a protocol known to inhibit the pulmonary tumorigenicity of 4NQO in A/HeJ mice enhanced hepatic and pulmonary activities for 4NQO metabolism by two major pathways, conjugative detoxification and nitroreductive activation. High-performance liquid chromatography analysis showed approximate doubling of two types of glutathione transferase subunits with 4NQO-conjugating activity in livers of BHA-treated mice. Similar increases were observed in hepatic 4NQO-conjugating activity and in Vmax, while Km for 4NQO was 39 to 43 microM. Pulmonary 4NQO-glutathione transferase activity increased 24 to 29%. DT diaphorase activity toward 4NQO was elevated 3.3-fold in livers and 2.7-fold in lungs of BHA-treated mice. However, the predominant 4NQO reductase of liver and lung was dicumarol resistant, had a strong preference for NADH, and showed little if any response to BHA. This Mr 200,000 enzyme, partially purified from livers of Swiss mice, exhibited the stoichiometry of 2-NADH/4NQO expected for reduction of 4NQO to 4-hydroxyaminoquinoline 1-oxide. Its high affinity for 4NQO (Km, 15 microM) signified a much greater influence on 4NQO metabolism than DT diaphorase (Km, 208 microM). The dicumarol-resistant 4NQO reductase differed from several known cytosolic nitroreductases. The results suggest that protection by BHA may result from alteration of the balance between 4NQO activation and conjugation.     

Intensity-dependent regional cerebral blood flow during 1-Hz repetitive transcranial magnetic stimulation (rTMS) in healthy volunteers studied with H215O positron emission tomography: I. Effects of primary motor cortex rTMS.

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) affects the excitability of the motor cortex and is thought to influence activity in other brain areas as well. We combined the administration of varying intensities of 1-Hz rTMS of the motor cortex with simultaneous positron emission tomography (PET) to delineate local and distant effects on brain activity. METHODS: Ten healthy subjects received 1-Hz rTMS to the optimal position over motor cortex (M1) for producing a twitch in the right hand at 80, 90, 100, 110, and 120% of the twitch threshold, while regional cerebral blood flow (rCBF) was measured using H(2)(15)O and PET. Repetitive transcranial magnetic stimulation (rTMS) was delivered in 75-pulse trains at each intensity every 10 min through a figure-eight coil. The regional relationship of stimulation intensity to normalized rCBF was assessed statistically. RESULTS: Intensity-dependent rCBF increases were produced under the M1 stimulation site in ipsilateral primary auditory cortex, contralateral cerebellum, and bilateral putamen, insula, and red nucleus. Intensity-dependent reductions in rCBF occurred in contralateral frontal and parietal cortices and bilateral anterior cingulate gyrus and occipital cortex. CONCLUSIONS: This study demonstrates that 1-Hz rTMS delivered to the primary motor cortex (M1) produces intensity-dependent increases in brain activity locally and has associated effects in distant sites with known connections to M1.     

Josephine Goldmark (1877–1950): A Biographic Sketch

Josephine Goldmark was one of those remarkable early-twentieth-century American women who, while seeking independence and fulfillment in their own lives, devoted themselves to humanitarian causes and social reform. She was deeply involved in efforts to improve working conditions for women and children. Her work led her into the arena of nursing, especially public health nursing, where she contributed significantly to the development of the profession.     

Extracapsular cataract extraction, posterior chamber lens insertion, and pars plana vitrectomy in one operation

Extracapsular cataract extraction (ECCE), placement of a posterior chamber intraocular lens (PC IOL), and pars plana vitrectomy were combined in a single operation in 24 patients. Sixteen of these, 11 of whom are diabetic, have had 6 months or more of follow-up. In all cases, excellent visualization of the posterior segment was obtained, and the surgical objectives were achieved. No diabetic patient without preoperative neovascularization of the iris had this complication later. The advantages and disadvantages of alternative techniques are discussed.     

Eating attitudes as related to demographic and personality characteristics: a high school survey

A survey of 577 high school students was conducted to assess attitudes toward eating and their relationship to demographic and personality characteristics. Students completed a demographic questionnaire, and Eating Attitude Test (EAT-26) and the Basic Personality Inventory (A-BPI). When a cut-off score of 20 on EAT-26 was applied, overall prevalence of disordered eating attitude was found to be 7.5%. Groups scoring in pathological versus normal ranges showed no significant difference in mean age, socioeconomic status or race. The former group reported significantly shorter height and lower body weight. Of the subjects, 6.06% reported weight below the 10th percentile. This subgroup did not vary from those above the 10th percentile on sociodemographic and psychopathological variables, nor in prevalence of abnormal eating attitudes. Analysis of the A-BPI data showed subjects with abnormal eating attitudes had increased psychopathology in several areas, with greater neurotic tendencies, lower self-esteem and higher levels of deviant thinking and behaviour.     

Postantibiotic effect of clarithromycin alone and combined with ethambutol against Mycobacterium avium complex.

The postantibiotic effect (PAE) of clarithromycin alone and in combination with ethambutol was determined for two clinical blood isolates of Mycobacterium avium complex. An average PAE, ranging from 5.5 to 18.0 h, was noted for each isolate at each clarithromycin concentration except when isolate B was exposed to clarithromycin at the MIC. The addition of ethambutol did not enhance the PAE observed with clarithromycin alone. The clinical implications of the PAE of clarithromycin for M. avium complex remain to be determined.