Structure and sequence of the mouse V1a and V1b vasopressin receptor genes

The structural organization and 5'-flanking region of the mouse V1a and V1b vasopressin receptor genes were determined. The mouse V1a receptor gene was located within an 8-kb XbaI fragment, and the mouse V1b receptor gene was located within a 14-kb EcoRV fragment. Both genes were comprised of two coding exons that were separated by a 2.3-kb and a 8.0-kb intron, respectively, located before the respective seventh transmembrane domain of the receptor sequence. The availability of these genes would allow us to study the functional role of V1a and V1b receptors by disrupting the gene in mice.     

Effect of ticlopidine on exercise-induced platelet aggregation and exercise tolerance time in patients with ischemic heart disease

Platelet aggregation is one of the most important mechanisms for acute myocardial infarction during exercise. We sought to evaluate the effect of ticlopidine (TP) on platelet aggregation (PA) during exercise in patients with ischemic heart disease (IHD). We studied 38 patients with IHD, 26 patients with effort angina pectoris, and 12 patients with a previous myocardial infarction. In protocol I, subjects were divided into two groups. Drugs altering platelet aggregation were withheld 2-4 weeks before the study in 25 patients (control group). TP (200 mg/day) was administered for 7 days in 13 patients (ticlopidine group). A symptom-limited modified Bruce protocol treadmill exercise test was performed. PA was measured at rest and after exercise by using optical densitometry induced by adenosine diphosphate (ADP). PA ratio (percentage of maximum) was compared. In protocol II, in 12 patients, treadmill exercise test and PA measurement were performed with and without TP. PA significantly increased after exercise in control (from 51.7+/-23.3% to 64.4+/-27.7%, p < 0.01) and ticlopidine (from 31.9+/-10.5% to 42.0+/-20.4%, p < .01) groups; however, its grade was lower in the ticlopidine group than in the control group. After exercise, PA was lower in the ticlopidine group than in control group (42.0+/-20.4% vs. 64.4+/-27.7%; p < 0.01). In the same patients, PA was lower with TP than without TP after exercise. Treadmill exercise-tolerance time was greater in the ticlopidine group than in the control group, but not statistically significant (762.3+/-139.2 vs. 711.6+/-169.6 s; NS). Exercise-tolerance time was significantly greater with TP than without TP in same patient (791.7+/-98.9 vs. 733.3+/-152.8 s; p < .05). TP suppressed the increase of PA during exercise and increased the exercise-tolerance time in patients with IHD.     

Arthus tonsillitis in the rabbit. Histological findings and fibrinolytic activity in the blood

Arthus-type hypersensitivity was induced experimentally in the tonsils of rabbits. Histopathological studies were performed on the Arthus tonsillitis so produced, and estimations of the plasma fibrinolytic activity were made on the blood of these rabbits. The findings obtained by macroscopic inspection of the tonsil revealed significant bleeding and swelling. Furthermore, the histopathological studies demonstrated bleed and infiltration of leukocytes into various parts of the parenchyma and connective tissue surrounding the tonsil during the early stages of tonsillitis. From the results concerning certain parameters of the fibrinolytic system in the blood, it was demonstrated that, during the early stage of tonsillitis, the fibrinolytic activity increased and whole plasmin was consumed. Based on the above findings, it seems that the change in fibrinolytic activity found in rabbits affected by Arthus tonsillitis closely resembles that in patients suffering from acute tonsillitis.     

Purine phosphoribosyltransferase activities in guinea pig epidermis

Purine phosphoribosyltransferase activities in normal and experimental hyperkeratotic epidermis of guinea pig skin were demonstrated quantitatively by a new microassay method. The ratio of HGPRTase with hypoxanthine as a substrate to APRTase activity in normal and hyperkeratotic epidermis was found to be 0.94 and 0.60, respectively. The HGPRTase and APRTase activities expressed as micromoles per gram wet weight per min. were increased in experimental hyperkeratotic epidermis and it is suggested that the salvage pathway for purine nucleotide biosynthesis is activated in experimental hyperkeratotic epidermis. The pH optimum of these enzymes and their stability in the frozen state were also demonstrated.     

Membranous lipodystrophy

Summary The case is described of a 35-year-old housewife diagnosed as having membranous lipodystrophy (as described by Nasu et al. in 1970 and called lipomembranous polycystic osteodysplasia by Hakola in 1972). The main symptom of this patient was a slowly progressive dementia. Skeletal symptoms were not seen. The computerized tomogram of the brain showed calcification of bilateral basal ganglia and the plain roentgenograms of the bones revealed cystic radiolucent areas at the distal end of the bones of the patient's extremities. Histological examination of the curetted material from the right talus revealed a membranocystic pattern. The fatty tissue curetted from the cyst of the talus and the lysosomal enzymes of the white blood cells were biochemically normal. A possible relationship between this disease entity and connective disorders is considered.     

Does severe nutcracker phenomenon cause pediatric chronic fatigue?

BACKGROUND: In the past five years we experienced 9 fatigued disabled children who were intermittently or persistently absent from school. PATIENTS: They had been suspected to be burdened with psychosomatic disorders, having orthostatic hypotension, postural tachycardia, or other autonomic dysfunction symptoms. RESULTS: Investigating the cause of moderate orthostatic proteinuria in some of them, we found by chance severe typical nutcracker phenomenon (NC), which was present in all 9 children complaining of chronic fatigue. CONCLUSION: Their symptoms filled the criteria of chronic fatigue syndrome or idiopathic chronic fatigue (CFS/CF). An association between severe NC and autonomic dysfunction symptoms in children with CFS/CF has been presented.     

False leukemia-lymphoma cell lines: an update on over 500 cell lines.

Human leukemia-lymphoma (LL) cell lines represent an extremely important resource for research in a variety of fields and disciplines. As the cell lines are used as in vitro model systems in lieu of primary cell material, it is crucial that the cells in the culture flasks faithfully correspond to the purported objects of study. Obviously, proper authentication of cell line derivation and precise characterization are indispensable requirements to use as model systems. A number of studies has shown an unacceptable level of LL cell lines to be false. We present here the results of authenticating a comprehensively large sample (n = 550) of LL cell lines mainly by DNA fingerprinting and cytogenetic evaluation. Surprisingly, near-identical incidences (ca 15%) of false cell lines were observed among cell lines obtained directly from original investigators (59/395: 14.9%) and from secondary sources (23/155: 14.8%) implying that most cross-contamination is perpetrated by originators, presumably during establishment. By comparing our data with those published, we were further able to subclassify the false cell lines as (1) virtual: cross-contaminated with and unretrievably overgrown by other cell lines during initiation, never enjoying independent existence; (2) misidentified: cross-contaminated subsequent to establishment so that an original prototype may still exist; or (3) misclassified: unwittingly established from an unintended (often normal) cell type. Prolific classic leukemia cell lines were found to account for the majority of cross-contaminations, eg CCRF-CEM, HL-60, JURKAT, K-562 and U-937. We discuss the impact of cross-contaminations on scientific research, the reluctance of scientists to address the problem, and consider possible solutions. These findings provide a rationale for mandating the procurement of reputably sourced LL cell lines and their regular authentication thereafter.     

Metastasis to the iris in squamous cell lung cancer

A 72-year-old Japanese woman, suffering from squamous cell lung cancer with brain metastasis, underwent 2 courses of combination chemotherapy, consisting of cisplatin and vindesine. Although both the primary tumor and the brain metastasis regressed markedly, she developed left ocular pain with blurred vision. An abnormal mass was found in the left iris, and cytologic examination of the aqueous aspirate revealed a few malignant cells, which, when examined by electron microscopy, were considered to be derived from squamous cell carcinoma of the lung.