Distribution and role of aspartate in the nervous system of the chaetognath Sagitta

Forty-nine female workers in the shoemaking industry, exposed to a solvent mixture containing benzene and twenty-seven non-exposed controls, were investigated. Concentrations of benzene and toluene in the working atmosphere, as well as benzene and toluene in blood and phenols in pre- and post-shift urine as parameters of biological monitoring, were determined. In order to assess hematotoxic risk, a complete blood cell count with differential, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, reticulocytes, serum iron, alkaline phosphatase in neutrophils and red blood cell glycerol lysis time were determined in all subjects. Benzene concentrations in the workplace atmosphere at the shoemaking factory ranged from 1.9 to 14.8 ppm (median = 5.9). Significant difference in benzene in blood (p = 0.005) and phenol in post-shift urine (p = 0.003) between exposed workers and controls confirmed exposure to benzene. Hemoglobin level (p = 0.02) and mean corpuscular hemoglobin concentration (p = 0.0002) in the shoe workers were lower, and band neutrophils (p = 0.005) and mean corpuscular volume (p = 0.03) higher, than in controls. Red blood cell glycerol lysis time was significantly higher (p = 0.000001) in shoe workers (X +/- SD = 41.6 +/- 8.9) than in controls (X +/- SD = 31.1 +/- 6.5) and showed a significant correlation with exposure biomarkers. The results confirm that benzene exposure below 15 ppm may produce qualitative abnormalities, particularly macroerythrocytosis and increased red cell glycerol resistance, in the absence of an overt quantitative decrease in circulating blood cells. Increased resistance to the hemolytic action of glycerol is a potentially useful biological monitoring procedure in medical surveillance of benzene exposed workers. The results of this study suggest that potential threshold concentration for hematologic effects of benzene is lower than 15 ppm.     

Is semen quality related to the year of birth among Danish infertility clients?

BACKGROUND: There is circumstantial evidence that human sperm count may have declined during past decades. The purpose of this study was to identify the association between semen quality and year of birth. METHODS: The study comprised 8608 men consulting four Danish medical centres from 1968 to 1992 because of infertility. Data on semen quality and urogenital disorders were obtained from medical records while lifestyle data were collected from a subset of the population by a postal questionnaire (response 80%). Semen characteristics were analysed as a linear function of year of birth, centre, season and calendar year at time of semen examination, sexual abstinence and lifestyle factors. Effects of age were accounted for by restriction and stratified analysis. RESULTS: The sperm count declined with increasing year of birth at two of the four centres, but this association disappeared when confounders were adjusted for. Within the subset of men born 1950-1970 we revealed a decrease in the average sperm count by 1.9 mill/ml (95% confidence interval [CI]: 1.45, 2.27) per one advancing year of birth. This finding was consistent across centres even after adjustment for effects of covariates. The proportion of morphologically normal sperm cells changed in parallel with the sperm count, while semen volume did not decline in any time periods. CONCLUSIONS: We found a birth cohort effect on sperm count and morphology among Danish infertile men born after 1950 but not in men born in the first part of the century. The findings are compatible with an environmental impact during prenatal life but the evidence is far from unequivocal.     

Mutation Lys758 --> Ile of the sarcoplasmic reticulum Ca2+-ATPase enhances dephosphorylation of E2P and inhibits the E2 to E1Ca2 transition

The highly conserved lysine residue Lys758 in the fifth stalk segment of the sarcoplasmic reticulum Ca2+-ATPase was substituted with either isoleucine or arginine by site-directed mutagenesis. The substitution with arginine was without significant effects on Ca2+-ATPase function, whereas multiple changes of functional characteristics were observed with the Lys758 --> Ile mutant. These included insensitivity of ATPase activity to the calcium ionophore A23187, an alkaline shift of the pH dependence of ATPase activity, reduced maximum molecular turnover rate and steady-state phosphorylation level, reduced apparent affinities for Ca2+ and inorganic phosphate, as well as increased sensitivity to inhibition by vanadate. Analysis of the partial reaction steps of the enzyme cycle traced these changes to two steps. The rate of dephosphorylation of the ADP-insensitive phosphoenzyme intermediate (E2P) was increased, irrespective of variations of pH, K+, Ca2+, and dimethyl sulfoxide concentration. In addition, the rate of conversion of the dephosphoenzyme with low Ca2+ affinity (E2) to the Ca2+-bound form activated for phosphorylation (E1Ca2) was reduced in the mutant, and the ATP-induced rate enhancement of this step required higher ATP concentrations in the mutant compared with the wild type.     

Management of flatback and related kyphotic decompensation syndromes

STUDY DESIGN: The authors, in this retrospective study, examined a group of patients with flatback syndrome and a related kyphotic decompensation syndrome. Results of nonrealignment treatment as well as revision surgery with sagittal realignment were reviewed. OBJECTIVES: To determine effectiveness of physical therapy and limited surgical (instrumentation removal) as well as major realignment surgical treatment in the sagittally malaligned spine. SUMMARY OF BACKGROUND DATA: Flatback is a sagittal plane deformity associated with distraction instrumentation for scoliosis correction. Kyphotic decompensation syndrome involves malaligned fusions from the sacrum for disease other than scoliosis. Several studies describe surgical realignment for flatback involving instrumentation systems no longer commonly applied. Guidelines for a systematic approach to flatback and kyphotic decompensation syndromes are lacking. METHODS: Forty-eight patients with flatback and kyphotic decompensation syndromes were reviewed. Treatment groups were defined by treatment approach and level of previous fusion. Effectiveness of treatment was reviewed in terms of radiographic sagittal alignment and self-reported pain. RESULTS: Twenty patients were treated without realignment revision surgery. Twenty-eight patients were treated with anterior and posterior osteotomies and realignment with instrumentation. For patients originally fused to the sacrum, realignment averaged 12 cm. Pain was reduced from 7 to 3 (10-point scale). In patients fused to L4 or L5, realignment averaged 7 cm. Pain was reduced from 6 to 2. Magnetic resonance imaging revealed viable caudal discs in four patients who were consequently spared extension of fusion to the sacrum. CONCLUSIONS: Treatment without realignment surgery demonstrated long-term success in 27% of cases. The latter all had two intact discs below the previous fusion and sagittal malalignment less than 4 cm. Realignment surgery effectively reduced pain in patients failing a conservative approach.     

Oxygen in the field hospitals: current experience in the military health service]

A fifty per cent oxygen ratio locks quite sufficient for putting at sleep war wounded patient. After the present time, every french field surgical structures are equipped with oxygen extractors. Furthermore, those teams have at heir disposal for several years, oxygen generators, working with sodium chlorate candels. Those one can fill oxygen cylinders (3.5 l at 90 or 150 bars), providing pure oxygen, which will ever be essential under exceptional conditions. During war period, the supply difficulties demand to have at disposal two different production capabilities for oxygen administration.     

Time course evolution of ventilatory responses to inspiratory unloading in patients

Inspiratory muscle unloading decreases ventilatory drive. In this study, we examined the time course of this effect in patients with chronic obstructive pulmonary disease receiving two modes of ventilatory support: pressure support ventilation (PSV), during which each cycle was assisted, and biphasic positive airway pressure (BIPAP), set up in such a manner that one spontaneous breath took place between two consecutive pressure-assisted breaths. The first breath following the switch from spontaneous breathing to PSV was associated with an increase in tidal volume (VT) and a drop in mean transdiaphragmatic pressure (mean Pdi) and inspiratory work (WI) performed per liter but with unchanged values of esophageal occlusion pressure at 100 ms (Pes 0.1), diaphragmatic electrical activity (EMGdi), and WI performed by breath. The same phenomena were observed for the assisted breath of BIPAP as compared with the preceding spontaneous breath. During the subsequent breaths of PSV, Pes 0.1, EMGdi, and WI performed per breath decreased progressively up to the sixth to eighth breaths, and VT returned to pre-PSV values. We conclude that in patients with chronic obstructive pulmonary disease the decrease in ventilatory drive associated with PSV takes place from the first breath onwards but requires six to eight breaths to be fully achieved. During BIPAP, as a consequence of the kinetics of the PSV-induced downregulation of ventilatory drive, assisted breaths following spontaneous breaths are characterized by an enhanced inspiratory efficiency.     

Postoperative outcome of Crohn's disease in 30 children

BACKGROUND: Thirty children operated on for Crohn's disease (CD) were reviewed (1975-1994). The aim of the study was to assess their postoperative outcome. PATIENTS: 19 boys and 11 girls, aged 15.3 (2) years (range 11.3-20) at surgery were studied. RESULTS: Surgical indications were acute complications of CD and chronic intestinal illness. Six months after surgery, 11 of 12 patients had been weaned off steroids, and 22 of 23 patients were weaned off nutritional support; 17 patients without recurrence had a mean (SD) weight gain of 2.1 (8) kg and a height gain of 3.36 (3) cm. During 3.1 (2.7) years follow up, 12 patients (40%) had a recurrence of the disease after 19.4 (14) months (means (SD)): supra-anastomotic recurrence (six), severe perianal disease (two), and chronic illness (four). Six of 14 patients who were treated with mesalazine (13) or azathioprine (one) had recurrences. The postoperative recurrence rate was 50% at two years. CONCLUSION: Surgical treatment modifies the immediate outcome of severe or complicated CD, but does not prevent recurrence, despite localised resection or prophylactic postoperative treatment. Extension of the disease before surgery seems to be a major risk factor for postoperative recurrence in children.