Sequence variants in the pancreatic islet beta-cell inwardly rectifying K+ channel Kir6.2 (Bir) gene: identification and lack of role in Caucasian patients with NIDDM

The septate gregarine parasites of flour beetles (Tribolium spp.) include Gregarina minuta Ishii, 1914, a relatively small species in which both primite and satellite possess an obvious protomerite, and a larger species that lacks the satellite protomerite. The latter species has been placed in the genera Didymophyes and Hirmocystis by various authors, but studies reported here demonstrate that this species, herein described as Gregarina triboliorum, exhibits early pairing and produces oocyst chains, both characteristics of the genus Gregarina. The oocysts of this new species are described for the first time. In addition, experimental infections using oocyst from single gametocysts reveal that oocyst chain number is variable but is typically 1, 2, or 4. Prior experiments involving a related beetle, Tenebrio molitor, demonstrated extreme host specificity within the 4 Gregarina species parasitizing larval and adult hosts. However, G. triboliorum is not limited either stadially or specially, infecting both adults and larvae of Tribolium confusum and Tribolium castaneum.     

Assembly and analysis of conical models for the HIV-1 core

The genome of the human immunodeficiency virus (HIV) is packaged within an unusual conical core particle located at the center of the infectious virion. The core is composed of a complex of the NC (nucleocapsid) protein and genomic RNA, surrounded by a shell of the CA (capsid) protein. A method was developed for assembling cones in vitro using pure recombinant HIV-1 CA-NC fusion proteins and RNA templates. These synthetic cores are capped at both ends and appear similar in size and morphology to authentic viral cores. It is proposed that both viral and synthetic cores are organized on conical hexagonal lattices, which by Euler's theorem requires quantization of their cone angles. Electron microscopic analyses revealed that the cone angles of synthetic cores were indeed quantized into the five allowed angles. The viral core and most synthetic cones exhibited cone angles of approximately 19 degrees (the narrowest of the allowed angles). These observations suggest that the core of HIV is organized on the principles of a fullerene cone, in analogy to structures recently observed for elemental carbon.     

Diffuse leptomeningeal gliomatosis associated with multifocal CNS infarcts

BACKGROUND: Widespread dissemination of astrocytoma throughout the cerebrospinal fluid is unusual, especially as the initial presentation in a patient, and association with cerebral infarcts is rare. CASE DESCRIPTION A 47-year-old man subacutely developed progressive headache and backache, vomiting, altered consciousness, and numbness in both arms. Brain computerized axial tomography showed calcification in the fourth ventricle and magnetic resonance imaging demonstrated diffuse meningeal enhancement, a lesion in the canal of Magendie, and T2-weighted hyperintense lesions in several locations. Angiography showed vasospasm/vasculopathy involving multiple cerebral vessels. Biopsy of the fourth ventricular mass revealed a subependymoma with an overlying leptomeningeal anaplastic astrocytoma with numerous Rosenthal fibers. The patient was treated with three doses of intrathecal methotrexate via lumbar puncture but suddenly became unresponsive and died 6 days later, 8 weeks after initial symptoms. Autopsy demonstrated the subependymoma and a widespread leptomeningeal anaplastic astrocytoma, which showed no clear-cut origin from the subependymoma, but microscopically infiltrated the left medial temporal lobe. Multiple subacute and acute infarcts of the brain, brain stem, and upper spinal cord were seen only in areas with leptomeningeal tumor. CONCLUSION Glioma cells surrounding and focally permeating central nervous system vessels without lumenal occlusion can lead to vasospasm and widespread infarcts.     

Isolated lung perfusion with tumor necrosis factor for pulmonary metastases

BACKGROUND: A phase I trial was initiated to define the feasibility and safety of single-lung isolation perfusion with tumor necrosis factor-alpha, interferon-gamma, and moderate hyperthermia for patients with unresectable pulmonary metastases. METHODS: Twenty patients with lung metastases (Ewing's, 2; sarcoma, 8; melanoma, 6; other, 4) were considered for single-lung isolation perfusion with 0.3 to 6.0 mg of tumor necrosis factor-alpha and 0.2 mg interferon-gamma delivered through an oxygenated pump circuit. Sixteen perfusions were performed in 15 patients (bilateral in 1). Metastases were completely resected (no single-lung isolation perfusion) in 3 patients, 1 patient had extrapulmonary disease, and one single-lung isolation perfusion was aborted for mechanical reasons. RESULTS: There were no significant changes in systemic arterial blood pressure or cardiac output during perfusion. Systolic pulmonary artery pressure increased with isolation, but returned to pre-single-lung isolation perfusion levels after clamp release. The maximum systemic tumor necrosis factor-alpha level was 8 ng/mL, whereas pump-circuit levels ranged from 200 to 10,976 ng/mL. There were no deaths, and the mean hospitalization period was 9 days (range, 5 to 34 days). A short-term (6 to 9 month) unilateral decrease in perfused nodules was noted in 3 patients (melanoma in 1, adenoid cystic carcinoma in 1, renal cell carcinoma in 1). CONCLUSIONS: Future studies using a combination of biologic modifiers, chemotherapy, and hyperthermia should be pursued to define active cytotoxic agents that will preserve underlying pulmonary function.     

Torsional hot workability in 0.47C-0.86Mn-0.5Cr-B steel from 650°c to 870°C

A 0.45 C steel (AISI 50B44) was heat-treated to produce either the spheroidized or pearlitic microstructure. Specimens were torsionally deformed in the temperature range of 650°C to 870°C and equivalent strain-rate range of 0.17 to 4.85 s⁻¹. In the ferrite regime, the lamellar structure exhibited much higher maximum stresses and work softening, followed by lower fracture strains, than did the spheroidal structure. Moreover, the carbide plates began to break up, whereas the spheroids only grew larger. In the austenite regime, their behaviors were almost identical; the peak stress was less and the ductility much higher than in the ferritic regime. The dynamically recrystallized austenitic grain size was larger as the temperature rose or the strain rate declined. Constitutive relationships were determined for the three distinct structures: (a) ferritic, spheroidized carbide; (b) ferritic, lamellar carbide; and (c) austenitic carbide. The work softening in the ferritic conditions can be interpreted as resulting from spheroidization or coalescence of the carbides as the matrix undergoes dynamic recovery. The peak stress followed by softening to a steady state in the austenite is related to dynamic recrystallization.     

Prognostic values of echocardiography compared with clinical variables in suspected heart disease. Multivariate analysis of long-term prognosprognosis in 456 patients

The aim of the study was to evaluate the prognostic significance of clinical and echocardiographic data in patients referred for echocardiography in a retrospective analysis. Four hundred and fifty-six patients from a district hospital were studied. Survival after three years was 64%. Multivariate analysis identified five factors with independent prognostic information (relative risks of death are shown in brackets): left ventricular wall motion index (WMI) < or = 1.2 by echocardiography (2.5), status as in-patient (2.1), age > 65 years (1.7), clinical heart failure (1.9) and atrial fibrillation (1.5). When information on age, hospitalisation status, heart failure and heart rhythm had already been entered in the Cox model, echocardiographic results such as decreased WMI and dilated right ventricle still gave further prognostic information. We conclude that among conventional clinical and echocardiographic data WMI was the strongest predictor of long-term survival, and, despite prior knowledge of major clinical features, echocardiography provided further prognostic information.