Effects of GYKI 52466 on early vasospasm in rats.

OBJECTIVE: The pathogenesis and treatment of cerebral vasospasm (CV) after subarachnoid hemorrhage (SAH) remains a matter of discussion. The authors investigated the efficacy of GYKI 52466, a 2,3-benzodiazepine that is a selective and potent alpha-amino-3-hydroxy-5-methylisoxazole-4-proprionic acid (AMPA) receptor antagonist, in a rat femoral artery vasospasm model. METHODS: Twenty-seven Wistar albino rats were used in this study. The animals were divided into 3 groups of 9 animals each: sham-operated control (group 1), vasospasm group (group 2), and vasospasm-plus-treatment group (group 3). In groups 2 and 3, autologous blood (0.1 mL) was applied to a 1-cm segment of the femoral artery, which was then wrapped with a silicone cuff. One minute after blood application, the rats in group 3 received an intraperitoneal injection of 15 mg/kg GYKI 52466 every 12 h for 24 h. Responses to blood application and treatment were evaluated with light and electron microscopy examinations of femoral artery specimens at 72 h. RESULTS: On light microscope examination, the mean diameters of the arterial lumens in groups 1, 2, and 3 were 514.47+/-15.3, 317.63+/-12.1, and 503.91+/-9.6 microm, respectively. At 24 h, the mean arterial wall thickness in group 1 was 77.69+/-4.2 microm. This mean thickness in group 2 increased to 164.82+/-9.1 microm. After GYKI treatment in group 3, the mean arterial wall thickness measured 95.37+/-5.3 microm. In group 2 rats, electron microscopy demonstrated various changes including marked luminal narrowing and increased wall thickness in the femoral arterial wall. The most striking finding were the degenerative changes in the endothelium, which presented as a corrugated appearance of the internal elastic lamina. Rats in group 3 had endothelia that were slightly constricted and smooth muscle cells that were relaxed; changes in the vessel wall and internal elastic lamina were less prominent in these rats than in the rats of group 2. CONCLUSIONS: The results of the present study suggest that GYKI 52466 inhibited AMPA receptors and induced relaxation of smooth muscle cells in the wall of the femoral artery in a rat model. This substance may be a protective and therapeutic agent in the treatment of cerebral vasospasm.

The R110C mutation in Notch3 causes variable clinical features in two Turkish families with CADASIL syndrome.

Mutations in Notch3 gene are responsible for the cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). It is a late onset neurological disorder recognized by recurrent strokes and dementia. We describe here the clinical and molecular findings of three unrelated Turkish families with CADASIL syndrome. Two of the families were identified to have the same mutation, p.R110C (c.C328T), located in exon 3 of the Notch3 gene. Interestingly, the phenotypic expression of the disease in these two families was markedly different in severity and age of onset implicating additional genetic and/or non-genetic modulating factors involved in the pathogenesis. In addition, we identified the novel p.C201R (c.T601C) mutation in exon 4 of the Notch3 gene in a proband of the third family with two consecutive stroke-like episodes and typical MRI findings. Mutations described here cause an odd number of cysteines in the N-terminal of the EGF domain of Notch3 protein, which seems to have an important functional effect in the pathophysiology of CADASIL. The phenotypic variability in families carrying the same molecular defect as presented here makes the prediction of prognosis inconceivable. Although DNA analysis is effective and valuable in diagnosing approximately 90% of the CADASIL patients, lack of genotype-phenotype correlation and prognostic parameters makes the presymptomatic genetic counseling very difficult.

A Case with Micromegakaryocytes.

UNLABELLED: A boy with no previous history of bleeding presented with ecchymoses and splenomegaly. He was followed up for thrombocytopenia and micromegakaryocytes for 20 months till clinically malignancy was diagnosed. Micromegakaryocytes must always be treated with suspicion, as they may provide an important clue for dyshematopoesis. KEY WORDS: Micromegakaryocytes, Leukemia, Dismegakaryopoesis.

Case report: liver function abnormalities in a severe case of hyperreactio luteinalis.

Rare causes of liver dysfunction in pregnancy may pose a challenge to the consulting gastroenterologist or hepatologist from both the diagnostic and therapeutic standpoints. We describe here liver function abnormalities in a case of hyperreactio luteinalis with light and electron microscopic findings.

Persistent vacuoles in leukocytes: familial Jordans anomaly.

Multiple persistent vacuoles were seen in the neutrophils, monocytes and eosinophils of a 9 year old boy and his 10 year old sister. The siblings were both asymptomatic. In the bone marrow, the cytoplasmic vacuoles were also present in the promyelocytes, myelocytes and metamyelocytes, but not in the myeloblasts and they tended to be single and large in immature cells. The cytoplasmic vacuoles did not stain with PAS, Sudan Black or Oil Red O; Sudan III positivity of the vacuoles was found only in a very small number of granulocytes. The vacuoles appeared as round and bright bodies with phase contrast microscopy. By electron microscopy, the vacuoles contained material of low electron density and had no surrounding membrane. Granulocyte functions were unimpaired. Muscle biopsy showed normal morphology. This anomalous vacuolization of the leukocytes is consistent with familial Jordans anomaly.

Mitochondria-lytic action of warfarin in lymphocytes.

Warfarin given as a single dose of 20 mg induces lysis of mitochondria in lymphocytes from chronic and acute lymphocytic leukemias studied under the electron microscope. Normal lymphocytes remain unchanged. This cytotoxic actin may be due to superoxide radicals produced in the malignant cells by warfarin, which is a potent electron-transferring substance.