Focal cortical dysfunction and blood-brain barrier disruption in patients with Postconcussion syndrome.

Postconcussion syndrome (PCS) refers to symptoms and signs commonly occurring after mild head injury. The pathogenesis of PCS is unknown. The authors quantitatively analyzed EEG recordings, localized brain sources for abnormal activity, and correlated it with imaging studies. Data from 17 patients with neurologic symptomatology consistent with ICD-10 criteria for PCS was analyzed. Normalized quantitative EEG (QEEG) revealed significantly higher power in the delta band and lower power in the alpha band compared with matched controls. The generators for the abnormal rhythms were focally localized in neocortical regions. Brain computerized tomography and/or MRI did not reveal focal abnormality at the time of diagnosis. Single photon emission computed tomography (SPECT) after 99mTc-ethylcysteinate dimer administration showed a focal reduction in perfusion in 85% (n = 11) of the patients, and abnormal blood-brain barrier (BBB) after 99mTc-diethylenetriaminepentaacetic acid administration in 73% (n = 8). In 75% of these patients, low-resolution brain electromagnetic tomography analysis showed that the generators for abnormal rhythms were closely related to the anatomic location of the BBB lesion. These data point to focal cortical dysfunction in conjunction with BBB disruption and hypoperfusion as a possible mechanism of pathogenesis in at least some PCS patients, and offer QEEG and SPECT as important tools in evaluating these patients.     

Arterial regeneration over polydioxanone prostheses in the rabbit

We analyzed histologic, ultrastructural, and functional characteristics of rabbit aortic conduits regenerated over absorbable polydioxanone prostheses. Twenty-eight polydioxanone-elicited prosthesis/tissue complexes harvested two weeks to 12 months following implantation were analyzed grossly; photographed; sectioned for light, scanning, and transmission electron microscopy; and studied for compliance, bursting strength, and prostacyclin and thromboxane metabolite contents. No aortic-related deaths or hemorrhages occurred. Smooth regenerated conduits without stenoses were seen in 27 of 28 specimens, with one small aneurysm. Transprosthetic myofibroblast migration and proliferation paralleled the kinetics of macrophage-mediated prosthetic dissolution, which was consequently delayed compared with polyglycolic acid prostheses. Confluent endothelial-like luminal surfaces were present after two weeks. Progressive inner capsular thickening ended after three months at 420 micron. Ex vivo compliance curves resembled arterial elasticity. Regenerated tissue withstood 1200 mm Hg of systolic pressure, and 6-keto-prostaglandin F1 alpha to thromboxane B2 ratios did not differ from normal control specimens.     

Endocrinology: Human chorionic gonadotrophin is a better luteal support than progesterone in ultrashort gonadotrophin-releasing hormone agonist/menotrophin in-vitro fertilization cycles

In an attempt to determine the best luteal support in in-vitrofertilization (IVF) cycles treated with gonadotrophin-releasinghormone agonist (GnRHa) and human menopausal gonadotrophin (HMG)by the ultrashort protocol, 60 patients were prospectively randomizedfor either i.m. progesterone or human chorionic gonadotrophin(HCG) luteal support. The two groups did not differ in the meannumber of oocytes retrieved and embryos replaced, nor in themean age of the patients and the amount of HMG used. HCG maintainedhigher levels of oestradiol and progesterone during the lutealphase. Conception rate was significantly higher in the HCG group.We conclude that HCG is superior to i.m. progesterone as lutealsupport in IVF cycles in which GnRHa is used in the ultrashortprotocol.     

Individual implantation rate: proposal for a new index for evaluation of assisted reproduction results

Objective: To assess whether implantation in assisted reproductive technology (ART) cycles is a random event.Design: Retrospective analysis of results.Setting: Division for Reproductive Endocrinology and ART, Department of Obstetrics and Gynecology, Haemek Medical Center, Afula, Israel.Patient(s): A cohort of all cycles reaching ET from July 1, 1995, through June 30, 1996, and a cohort of all pregnancies recorded from January 1, 1995, through October 31, 1996.Intervention(s): None.Main Outcome Measure(s): Rate of multifetal pregnancy in relation to overall pregnancy rate. The number of gestational sacs observed by sonography, out of transferred embryos in conception cycles, was defined as the individual implantation rate.Result(s): Of 367 ETs, 75 (20.4%) yielded pregnancies, of which 31 (41%) were multifetal. Considering the mean number of embryos transferred (3.67), if implantation would have been random, multifetal gestation rate should have been only 14.8%, significantly less than the observed rate. In 110 pregnancies recorded between January 1995 and October 1996, individual implantation rate was 49.4% ± 27.1% in intracytoplasmic sperm injection cycles compared with 40.5% ± 20.4% in IVF cycles.Conclusion(s): Embryo implantation is not a random event. The index of individual implantation rate may help shed light on mechanisms underlying implantation.     

Prenatal hypoxia down regulates the GABA pathway in newborn mice cerebral cortex; partial protection by MgSO4.

The fetal and newborn brain is particularly susceptible to hypoxia, which increases the risk for neurodevelopmental deficits, seizures, epilepsy and life-span motor, behavioral and cognitive disabilities. Here, we report that prenatal hypoxia at gestation day 17 in mice caused an immediate decrease in fetal cerebral cortex levels of glutamate decarboxylase, a key proteins in the GABA pathway. While maternal MgSO4 treatment prior to hypoxia did not have an early effect, it did accelerate maturation at a later stage based on the observed protein expression profile. In addition, MgSO4 reversed the hypoxia-induced loss of a subpopulation of inhibitory neurons that express calbindin in cortex at postnatal day 14. In the hippocampus, responses to prenatal hypoxia were also evident 4 days after the hypoxia. However, in contrast to the observations in cerebral cortex, hypoxia stimulated key protein expression in the hippocampus. The hippocampal response to hypoxia was also reversed by maternal MgSO4 treatment. The data presented here suggests that decreased levels of key proteins in the GABA pathway in the cerebral cortex may lead to high susceptibility to seizures and epilepsy in newborns after prenatal or perinatal hypoxia and that maternal MgSO4 treatment can reverse the hypoxia-induced deficits in the GABA pathway.     

Anti-heart autoantibodies in ischaemic heart disease patients.

One hundred and ninety-nine ischaemic heart disease (IHD) patients were studied with regard to the prevalence of anti-heart autoantibodies (AHA). The incidence of AHA in IHD patients was 1%: one out of 102 patients who suffered acute myocardial infarction (AMI), one out of seventy-two patients who suffered from acute coronary insufficiency (ACI), and none out of twenty-five patients with other signs and symptoms of IHD, had AHA in their sera. An additional 2% of patients who suffered from AMI developed detectable antibody levels during a follow-up period of 15 days. In comparison,, 53% of patients (eight out of fifteen) who underwent heart surgery and who had no AHA prior to operation, developed these antibodies in their sera during 1-2 weeks following operation.     

Glutathione peroxidase activity in various types of blood cells in multiple sclerosis

Previous studies demonstrated a significantly lower mean activity of glutathione peroxidase (GSH-Px) in erythrocytes of patients with multiple sclerosis than in control groups of normal subjects or patients with various neurological disorders. The present investigation has demonstrated that, in contradistinction to erythrocytes, a normal activity of GSH-Px is found in lymphocytes, granulocytes and platelets of multiple sclerosis patients. These results were obtained both with hydrogen peroxide, which serves as a specific substrate for selenium dependent GSH-Px, and t-butyl hydroperoxide which reacts both with selenium dependent and independent GSH-Px.     

Mumps virus and ovarian cancer.

Thirty-four patients with carcinoma of the ovary were compared with controls matched for age, sex and racial origin. Previous mumps infection was determined by taking a history from the patient, by complement fixation test and by estimating neutralizing antibody titre. No significant differences between the two groups were found for any of the three methods used to estimate previous exposure to mumps virus. Therefore this study did not confirm previous hypotheses that mumps infection confers a significant degree of protection against the development of ovarian cancer. A relatively small proportion of cases could possibly be due to lack of such protection, but in this study not more than 30% at the 5% fiducial limit.