Cell cycle control and CDC28/Cdc2 homologue and related gene cloning of Cryptococcus neoformans]

In Cryptococcus neoformans the DNA content of cells having tiny buds varied rather widely, depending on growth phases and strains used. Typically, buds of C. neoformans emerged soon after initiation of DNA synthesis in the early exponential phase. However, bud emergence was delayed to G2 during transition to the stationary phase, and in the early stationary phase budding scarcely occurred, although roughly half of the cells completed DNA synthesis. The timing of budding in C. neoformans was shifted to later cell cycle points with progression of the growth phase of the culture. Similarly, a deficit in oxygen was demonstrated to delay the timing of budding, prolong the G2 phase and cause accumulation of cells after DNA synthesis, but before commitment to budding. The C. neoformans homologue of the main cell cycle control gene CDC28/Cdc2 was isolated using degenerate RT-PCR. The full-length coding region was then amplified using primers to target the regions around the start and stop codons. The gene was called CnCdk1 and was found to have high homologies to S. cerevisiae CDC28 and S. pombe cdc2. To determine its function, its ability to rescue S. cerevisiae cdc28-temperature sensitive mutants was tested. S. cerevisiae cdc28-4 and cdc28-1N strains transformed with the pYES2-CnCdk1 construct exhibited growth at the restrictive temperature. Results of the sequence analysis and the ability of CnCdk1 to complement the S. cerevisiae cdc28-ts mutations support its assumed role as the CDC28/cdc2 homologue in C. neoformans.     

The cholecystohepatic circulation of trichloroethylene and its metabolites in dogs

In order to examine the cholecystohepatic circulation of trichloroethylene (TRI) and its metabolites, we injected the gallbladder with TRI and its metabolites, i.e. chloral hydrate (CH), free-trichloroethanol (F-TCE), trichloroacetic acid (TCA) and conjugated-trichloroethanol (Conj-TCE), using anesthetized dogs. The absorption rates of water from the gallbladder were 25-30% 2 h after administration for all substances. The absorption rates of substances were 65-70% in the CH, F-TCE and TRI groups, and 40-50% in the Conj-TCE and TCA groups 2 h after the administration. Conj-TCE in the blood absorbed from the gallbladder has a tendency to be directly transported to the venous system rather than to be taken into hepatocytes in the liver. All of the administered substances, in particular, F-TCE might be metabolized to other substances in the gallbladder.     

Treatment of orthognathic problems related to scleroderma

Scleroderma is a generalized disorder characterized by abnormalities of the small arteries and vasculature resulting in thickening and prominent fibrosis of the affected tissues. Its etiology remains uncertain. All connective tissue and certain internal organs, notably the gastrointestinal tract, heart, lung, and kidneys, as well as skin, are typically involved. Mandibular movement can become severely restricted when the facial skin is affected, sometimes resulting in secondary changes to both the mandible itself and the temporomandibular joint. We present 2 cases in which we improved facial aesthetics and mandibular function by surgically correcting malocclusion with a Le Fort I osteotomy and maxillary intrusion in patients with manifestations of scleroderma in the face and neck.     

Temporal Delta Wave and Ischemic Lesions on MRI

Abstract: The present study was designed to determine the clinical significance of a temporal low-voltage irregular delta wave (TLID) on EEG. Among 808 EEG records examined during one year at our hospital, the TLID was commonly detected in patients with clinically diagnosed ischemic brain diseases such as multiple infarction. Subsequently, a relation of the TLID to ischemic lesions on MRI was examined in 50 elderly depressive patients. It was found that there was a close correlation between the occurrence of the TLID and small ischemic lesions on MRI (p<0.001). These results suggest that the TLID is a valuable indicator of minor ischemic changes of the brain.     

Localization by immunoelectron microscopy of spanning protein of triad junction in terminal cisternae/triad vesicles

Summary Polyclonal antibodies have been developed against the junctional feet or spanning protein from skeletal muscle triads. These probes in combination with immunogold labels have been used to localize the spanning protein by electron microscope of isolated vesicles from terminal cisternae/triads. The spanning protein antibodies specifically bind to the electron dense junctional feet. In vesicles permeabilized by hypotonic treatment or by saponin, some gold particles may be seen on the luminal side of the vesicle. Trypsin treatment of vesicles causes complete loss of the 300 K spanning protein from SDS gels while dot blots show that some but not all the antigenic activity is lost. This treatment is associated with the loss of the electron dense projections from the membrane surface and is coincident with the loss of immunogold staining when antibody is added to the intact vesicles. On the other hand, in experiments in which the luminal portions of the isolated vesicles have been made accessible to the polyclonal antibodies by sectioning lightly fixed vesicles before immunogold tagging, extensive gold labelling was found to occur in trypsin treated vesicles which have lost detectable projections from the cytoplasmic side of the membrane. These data support the view that the spanning protein projects from the sarcoplasmic reticulum towards the transverse tubules but further suggest that spanning protein extends into and probably through the sarcoplasmic reticulum membrane in accord with the proposition that it is a Ca²⁺ channel.Nomenclature SP spanning protein - SR sarcoplasmic reticulum - TC terminal cisternae - T-tubule transverse tubule - HMW high molecular weight - ELISA enzyme linked immunosorbent assay - PMSF phenylmethyl sulphonylfluoride - SDS sodium dodecyle sulphate     

Acute myocardial infarction: comparison of results of Tl-201, Tc-99m pyrophosphate and In-111 antimyosin Fab imagings]

To evaluate the extent and characteristics of infarct areas, we performed indium-111 monoclonal antimyosin Fab (InAM), thallium-201 (TL) and Tc-99m pyrophosphate (PYP) imagings in 17 patients with acute myocardial infarction, and tried to find out the mechanism that causes difference of these imagings. In each study, the extent scores as an index of the infarct area were obtained by single photon emission computed tomography (SPECT), and comparisons were made between the results obtained. The overlap between InAM and TL imagings obtained by SPECT was evaluated. Location, severity, extent and patterns of accumulation were compared between InAM and PYP with both planar image and SPECT. The extent scores of InAM correlated well with those of TL (r = 0.73, p < 0.01). However, the overlap of both methods was recognized in 8 of 17 patients, in whom wall thickness of the infarct area as obtained by echocardiography was well preserved. The left ventricular regional asynergy was mild in 6 of these 8 patients. Coronary angiography showed poor or no collateral circulation in these cases. Although there were generally close correlations of the extent scores between InAM and PYP, discrepancy was noted in 2 cases for location; 2 for severity, 5 for extent, and 3 for patterns of accumulation. These differences may be attributed to the timings of imaging, coronary reperfusion and different mechanisms of accumulation. In conclusion, the extent of acute myocardial infarction obtained by InAM correlates well with those obtained by TL and PYP, with some exceptions.     

Role of progenitor endothelial cells in cardiovascular disease and upcoming therapies.

The field of cell-based transplantation has expanded considerably and is poised to become an established cardiovascular therapy in the near future. In this review, we will focus on endothelial progenitor cells (EPCs), which are immature cells capable of differentiating into mature endothelial cells. EPCs share many surface marker antigens such as CD34, AC133, Flk-1, etc. with hematopoietic stem cells (HSCs) and the major source of EPCs as well as HSCs is the bone marrow (BM). BM-derived EPCs are mobilized into peripheral blood and recruited to the foci of pathophysiological neovascularization and reendothelialization, thereby contributing to vascular regeneration. Severe EPC dysfunction is an indicator of poor prognosis and severe endothelial dysfunction. Indeed, number of circulating EPCs and their migratory activity are reduced in patients with diabetes, coronary artery disease (CAD), or subjects with multiple coronary risk factors. Effective neovascularization induced by EPC transplantation for hindlimb, myocardial, and cerebral ischemia has been demonstrated in many preclinical studies, and early clinical trials of EPC transplantation in chronic and acute CAD indicate safety and feasibility of myocardial cell-based therapies. For therapeutic reendothelialization in patients undergoing percutaneous coronary intervention, CD34 antibody-coated stents have been used clinically to capture circulating EPCs at the injury sites and enhance reendothelialization and safety of stents. Further development in cell processing technology for efficient isolation, expansion, mobilization, recruitment, and transplantation of EPCs into target tissues are underway and expected to be tested in clinical trials in the near future.