Unaltered neuronal and glial counts in animal models of magnetic seizure therapy and electroconvulsive therapy.

Anatomical evidence of brain damage from electroconvulsive therapy (ECT) is lacking; but there are no modern stereological studies in primates documenting its safety. Magnetic seizure therapy (MST) is under development as a less invasive form of convulsive therapy, and there is only one prior report on its anatomical effects. We discerned no histological lesions in the brains of higher mammals subjected to electroconvulsive shock (ECS) or MST, under conditions that model closely those used in humans. We sought to extend these findings by determining whether these interventions affected the number of neurons or glia in the frontal cortex or hippocampus. Twenty-four animals received 6 weeks of ECS, MST, or anesthesia alone, 4 days per week. After perfusion fixation, numbers of neurons and glia in frontal cortex and hippocampus were determined by unbiased stereological methods. We found no effect of either intervention on volumes or total number or numerical density of neurons or glia in hippocampus, frontal cortex, or subregions of these structures. Induction of seizures in a rigorous model of human ECT and MST therapy does not cause a change in the number of neurons or glia in potentially vulnerable regions of brain. This study, while limited to young, healthy, adult subjects, provides further evidence that ECT and MST, when appropriately applied, do not cause structural damage to the brain.

The number of oogonia and somatic cells in the human female embryo and fetus in relation to whether or not exposed to maternal cigarette smoking.

BACKGROUND: Prenatal exposure to maternal cigarette smoking or compounds of cigarette smoke is associated with serious reproductive hazards such as apoptotic death of oogonia in murine offspring and decreased fecundability in human offspring. The present study addresses potential effects of in utero exposure to cigarette smoking. METHODS: Twenty-nine human first-trimester ovaries from legal abortions [aged 38-64 days post-conception (p.c.)] were collected. Mothers filled out a questionnaire about their smoking habits and delivered a urine sample for cotinine analysis. The ovarian cell numbers were estimated using stereological methods. RESULTS: A non-linear correlation between the numbers of oogonia and somatic cells in relation to age of the embryo/fetus was shown in 28 ovaries, including the first estimates performed in ovaries younger than 47 days p.c. Prenatal exposure to smoke showed a significant decrease in the number of somatic cells (P < or = 0.01). The number of oogonia was not significantly associated with prenatal exposure to maternal smoking (P < or = 0.09). The ratio between the two cell types decreased considerably from 1:45 to 1:23 from 38 to 46 days p.c. and was not affected by smoking. CONCLUSIONS: Oogonia proliferate and/or invade the developing ovary at a much faster relative rate than somatic cells. In utero exposure to maternal smoking significantly reduces the number of somatic cells from Days 38 to 64 p.c. Since oocytes cannot survive without being enclosed by somatic cells in a follicle, reduction in the somatic cells number may have long-range consequences on the number of oocytes available in adult life and on the future fertility of female offspring exposed to smoking in utero.

Validation of the MetaMax II portable metabolic measurement system.

The purpose of this study was to investigate the validity of the MetaMax II portable metabolic measurement system against the Douglas Bag technique. Nine recreationally active male subjects were included in a validation at 100 W, 10 well-trained male subjects at 200 W and 10 well-trained males at 250 W and at maximal exercise (volitional fatigue at a mean workload of 325 W). All testing was performed on an electronically braked bicycle at 60 rpm. At 100 W, the influence on MetaMax II measurements of adding a Douglas Bag breathing valve in series to the MetaMax II was investigated. The oxygen uptake was, for the MetaMax II, at 100 W mean 0.03 l x min (-1) higher (p < 0.01), at 200 W mean 0.02 l x min (-1) (n. s.) lower, at 250 W mean 0.04 l x min (-1) (n. s.) higher, and at 325 W mean 0.11 l x min (-1) (p < 0.05) higher. The carbon dioxide excretion was, for the MetaMax II, at 100 W mean 0.06 l x min (-1) (p < 0.01) lower, at 200 W mean 0.11 l x min (-1) (p < 0.05) lower, at 250 W mean 0.03 l x min (-1) (n. s.) lower, and at 325 W mean 0.16 l x min (-1) (p < 0.05) lower. The addition of a breathing valve in series to the MetaMax II resulted in lower breathing frequency, a higher ventilated tidal volume, and an affected gas measurement validation. In conclusion, the MetaMax II was found to be valid for metabolic gas measurements between 100 and at least 250 W.

Morphology of tracheal scar after resection with CO2-laser and high-frequency cutting loop. A study in normal pigs.

In 6 pigs a bronchoscopical resection of the tracheal mucosa was performed using CO2-laser on one side, and an electric high-frequency cutting loop (ECL) on the other. The pigs were sacrificed 3 months later. On macroscopic examination the tracheal mucosa appeared almost normal on the laser-resected side, while severe deformation was seen after ECL treatment. Microscopically the respiratory epithelium had regenerated irrespective of the instrument used. After laser resection the subepithelial tissue had a normal width and consisted of collagen fibrils with few vessels and sparse fragmented elastic tissue. The cartilage showed necrosis and pericellular fibrosis. The scar tissue after ECL was a broad cellular and richly vascularized connective tissue. The content of elastic fibres was markedly greater than after laser resection. The cartilage showed small irregular necroses lined by pyknotic nuclei. In neither case had the gland regenerated. Both CO2-laser and ECL caused severe (but not identical) damage to the tissue, clearly visible after 3 months. However, the deformation caused by ECL was not seen at the laser-resected sites, which makes the laser technique seem preferable--where economy permits.

Postanaesthetic arousal time in elderly patients. A double-blind study of glycopyrrolate and atropine.

Postanaesthetic arousal time was studied in elderly patients given either glycopyrrolate 0.01 mg kg-1 or atropine 0.02 mg kg-1 before antagonism of neuromuscular blockade. Forty patients (age greater than or equal to 65 yr) undergoing elective hip replacement were included in a double-blind study. Arousal was scored for 2 h after recovery using a modified scoring system. No difference in arousal time was found between the two groups.

Distribution of different fibre types in human skeletal muscles. I. Method for the preparation and analysis of cross-sections of whole tibialis anterior.

The aim of this study was to examine whether small biopsy specimens are representative of the whole human skeletal muscle or whether the different fibre types are unevenly distributed at different depths of the muscle. Ten micrometre thick cross-sections of whole human tibialis anterior were prepared using LKB PMV Cryo-Microtomes with a stroke length of 160 to 480 mm and the sections were stained for myofibrillar ATPase according to a modified procedure. The total and relative number of different fibres (Types 1 and 2) was determined in every 9th mm2 of the section. The data obtained were analysed by means of a computer program, which allowed assessment of bivariate data in the form of contour plots. The total number of fibres varied greatly between individuals (from 96 000 to 162 000; five individuals). The relative number of different fibres varied systematically in all individuals as a function of depth in the muscle. There was a gradual, often dramatic, relative increase in Type 2 fibre occurrence from the surface of the muscle (about 10--25%) towards the deeper regions (30--50%), the maximum being approximately along a line slightly posterior to the middle of the muscle. Additionally, superficial peaks were seen in places. In conclusion, the fibre type distribution in the tibialis anterior is not random. These results point to the importance of defining biopsy depth.