Progesterone induces a rapid increase in [Ca2+]in of Xenopus laevis oocytes.

Progesterone causes a rapid increase in the intracellular free calcium level in fully grown amphibian oocytes. When albino Xenopus laevis oocytes were microinjected with the Ca-specific photoprotein aequorin, the calcium-induced luminescence from this protein increased at 40-60 sec after the addition of progesterone and returned to the control level within 5-6 min. No further change in the aequorin glow could be detected through the remainder of the maturation period. This transient increase in cytoplasmic free calcium may be involved in controlling the resumption of oocyte maturation.     

Suppressive serum, suppressor lymphocytes, and death from burns

Both suppressor lymphocytes and serum immunosuppressive factors have been found in patients who have had major thermal burns, and may inhibit host resistance to the bacteria invariably present in burn wounds. However, the relationship and clinical importance of these two manifestations of impaired immune reactivity are poorly understood. Eighteen patients (aged 20-84 years) with full thickness burns of varying severity have been studied, and the clinical course related to the presence of nonspecific immunosuppressive serum and circulating suppressor lymphocytes. Serum factors capable of suppressing the phytohemagglutinin (PHA) response of normal lymphocytes usually appeared early and were detected in 15 of the 18 patients at some time during the illness. Thirteen of these patients developed systemic infection. Depression of the PHA response of peripheral blood lymphocytes was much less common and was associated with this finding died. No patients who did not have severe depression of the lymphocyte response to PHA died. Nonadherent leukocyte (NA leukocyte) populations exhibiting a depressed PHA response were capable of suppressing the PHA response of normal human lymphocytes and, therefore, contained suppressor cells.     

Studies on Rh Prophylaxis

One hundred and seventy-eight (178) Rh-negative volunteers, distributed into a treated and control series of six groups each, were studied to establish: (i) approximately 70 per cent of Rh-negative individuals are susceptible to being immunized by a single injection of Rh-positive blood; (ii) that, for immunologically susceptible individuals, the frequency of immunization increases with the volume of Rh-positive erythrocytes administered; and (iii) that a possible relationship exists between potency of Rh immune globulin and effectivity. This relationship can be used to calculate an effective dose of Rh immune globulin in the treatment of large feto-maternal hemorrhages or accidental tranfusions of Rh-positive blood to Rh-negative women.     

Randomized trial of four-layer and two-layer bandage systems in the management of chronic venous ulceration

To compare a four-layer bandage system with a two-layer system in the management of chronic venous leg ulceration, a prospective randomized open parallel groups trial was undertaken. In total, 112 patients newly presenting to leg ulcer services with chronic leg ulceration, screened to exclude the presence of arterial disease (ankle brachial pressure index <0.8) and causes of ulceration other than venous disease, were entered into the trial. Patients were randomized to receive either four-layer (Profore) or two-layer (Surepress) high-compression elastic bandage systems. In all, 109 out of 112 patients had at least one follow-up. After 24 weeks, 50 out of 57 (88%) patients randomized to the four-layer bandage system with follow-up had ulcer closure (full epithelialization) compared with 40 out of 52 (77%) on the two-layer bandage, hazard ratio = 1.18 (95% confidence interval 0.69-2.02), p = 0.55. After 12 weeks, 40 out of 57 (70%) patients randomized to the four-layer bandage system with follow-up had ulcer closure compared with 30 out of 52 (58%) on the two-layer bandage, odds ratio = 4.23 (95% confidence interval 1.29-13.86), p = 0.02. Withdrawal rates were significantly greater on the two-layer bandage (30 out of 54; 56%) compared with the four-layer bandage system (8 out of 58; 14%), p < 0.001, and the number of patients with at least one device-related adverse incident was significantly greater on the two-layer bandaging system (15 out of 54; 28%) compared with four-layer bandaging (5 out of 54; 9%), p = 0.01. The higher mean cost of treatment in the two-layer bandaging system arm over 24 weeks ($1374 [ pound 916] vs. $1314 [ pound 876]) was explained by the increased mean number of bandage changes (1.5 vs. 1.1 per week) with the two-layer system. In conclusion, the four-layer bandage offers advantages over the two-layer bandage in terms of reduced withdrawal from treatment, fewer adverse incidents, and lower treatment cost.     

Morphological and morphometric studies of the dysmyelinating mutant, the Long Evans shaker rat

The Long Evans shaker (les) rat is a recently identified CNS myelin mutant with an autosomal recessive mode of inheritance. Although scattered myelin sheaths are present in some areas of the CNS, most notably the ventral spinal cord in the young neonatal rat, this myelin is gradually lost, and 8-12 weeks little myelin is present throughout the CNS. Despite this severe myelin deficiency, some mutants may live beyond one year of age. Rare, thin myelin sheaths that are present early in development lack myelin basic protein (MBP) and on ultrastructural examination are poorly compacted and lack a major dense line. Many oligodendrocytes develop an accumulation of vesicles and membranous bodies, but no abnormal cell death is observed. In the optic nerve, cell kinetic studies show an increase in proliferation at early time points in les, while total glial cell counts are also increased in les from 2 months of age. In situ hybridization studies demonstrate that the numbers of mature oligodendrocytes are similar to controls early in life and increase with time compared to controls. There is both a progressive astrocyte hypertrophy and microgliosis. While les has a mutation in the myelin basic protein (mbp) gene, it is dissimilar in both genotype and phenotype to the previously described mbp mouse mutants, shiverer (shi) and shiverermld. Unlike shi and its allele, where myelin increases with time and oligodendrocytes become ultrastructurally normal, les oligodendrocytes are permanently disabled, continue to demonstrate cytoplasmic abnormalities, and fail to produce myelin beyond the first weeks of life.     

Preoperative optimization of cardiovascular hemodynamics improves outcome in peripheral vascular surgery. A prospective, randomized clinical trial.

The hypothesis that optimizing hemodynamics using pulmonary artery (PA) catheter (preoperative 'tune-up') would improve outcome in patients undergoing limb-salvage arterial surgery was tested. Eighty-nine patients were randomized to preoperative tune-up either in the surgical intensive care unit (SICU) (group 1) or the preinduction room (group 2) or to control (group 3). The tune-up consisted of fluid loading, afterload reduction, and/or inotropic support to achieve predetermined endpoints. Patients with a PA catheter had significantly fewer adverse intraoperative events (p less than 0.05), less postoperative cardiac morbidity (p less than 0.05), and less early graft thrombosis (p less than 0.05) than the control group. The overall study mortality rate was 3.4%, with a mortality rate of 9.5% in the control group and 1.5% in the PA catheter groups. There were no differences in ICU length of stay (LOS), hospital LOS, or total hospital costs, although the percentage of cost from complications was higher in group 3 (p greater than 0.05). In this group of patients, preoperative cardiac assessment and optimization is associated with improved outcome.     

Psychological factors influence the success of coronary artery surgery.

Thirty-six patients with angina were investigated by treadmill exercise testing and coronary angiography prior to coronary artery surgery. Severity of angina was judged by interview and self-assessment visual analogue scale and all patients were psychiatrically assessed. Further physical and psychiatric assessments were made at 3 and 6 months postoperatively. Eleven patients (31%) had significant psychiatric morbidity preoperatively and these had worse symptom scores and exercise tolerance compared with non-psychiatric cases, despite equivalent coronary angiographic findings and left ventricular function. Post-operatively, exercise tolerance improved equally in both groups but psychiatric cases remained significantly more symptomatic. Psychiatric morbidity remained unchanged throughout the study. We conclude that almost one third of patients with severe angina have psychiatric morbidity which is associated with a poor symptomatic response to coronary artery surgery, despite objective improvement in exercise tolerance. Ways of improving the symptomatic response to surgery in patients with coexisting psychiatric morbidity should be studied.