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Biomedical subjects

A Hayashi

Publications and source records attributed to A Hayashi.

At least 127 records · Page 7Linked to original sources
PubMed1998

Structure, chromosomal location, and expression profile of EXTR1 and EXTR2, new members of the multiple exostoses gene family.

Hereditary multiple exostoses (EXT) is an autosomal dominant disorder that is characterized by the appearance of multiple outgrowths of the long bones (exostoses) at their epiphyses. Genetical heterogeneities have segregated at least on chromosome 8, 11, and 19 and been designated EXT1, EXT2, and EXT3, respectively. Recently, the responsible genes for EXT1 and EXT2 have been isolated and appeared to define a structurally related gene family. In the present study, we have identified novel genes which share significant sequence homologies with the EXT genes. The predicted protein products of the novel EXT-related genes, EXTR and EXTR2 (for EXT-related genes 1 and 2), consist of 919 and 330 amino acid residues, respectively. These genes were transcribed ubiquitously in various tissues. Based on PCR-assisted analyses of both a human/rodent mono-chromosomal hybrid cell panel and a radiation hybrid mapping panel, EXTR1 was localized to the chromosome 8p21 region, where loss of heterozygosity has been frequently observed in various tumors, and EXTR2 was assigned to the chromosome 1p21 region, where osteopetrosis, a dominant hereditary disease of bone, has been mapped by genetic linkage analysis, implying that the protein products of these two EXT-related genes, as well as of the EXT genes, have potential tumor suppressor activity.

Amino Acid Sequence↗
PubMed1998

Horner's syndrome associated with mononeuritis multiplex due to cytomegalovirus as the initial manifestation in a patient with AIDS.

We report on a 60-year-old male with AIDS who presented Horner's syndrome that was associated with mononeuritis multiplex due to cytomegalovirus (CMV) infection. This is the first case who presented Homer's syndrome in the course of AIDS. Horner's syndrome associated with mononeuritis multiplex in this patient was the initial manifestation without any opportunistic infections. Since Horner's syndrome and mononeuritis multiplex in the present case were both improved by ganciclovir, it is important to consider CMV infection when Horner's syndrome or mononeuritis multiplex is observed in immunocompromised patients, such as those with HIV-1 infection or AIDS, even if they do not show any other opportunistic infections.

AIDS-Related Opportunistic Infections↗
PubMed1998

Pneumatic displacement of subretinal hemorrhage without tissue plasminogen activator.

OBJECTIVE: To assess the efficacy and complications of intravitreal injection of perfluoropropane gas for displacement of subretinal hemorrhage (SRH), without the use of tissue plasminogen activator. PATIENTS AND METHODS: Pure perfluoropropane gas (0.4-0.5 mL) was injected into the vitreous cavity in 5 patients with SRH involving the fovea because of age-related macular degeneration (4 eyes) or ruptured retinal arterial macroaneurysm (1 eye). The patients were instructed to maintain a prone position. RESULTS: Visual acuity ranged from 20/300 to 20/2000 before gas injection. On the day after gas injection, SRH was dramatically displaced in 3 eyes and slightly displaced with a reduction in the thickness of subfoveal hemorrhage in the remaining 2 eyes. Final visual acuity improved in all cases, ranging from 20/15 to 20/220. Three eyes had a final visual acuity of 20/50 or better. Vitreous hemorrhage caused by migration of SRH into the vitreous cavity and retinal detachment each occurred in 1 eye, and both complications were successfully treated by vitrectomy. CONCLUSIONS: Gas injected into the vitreous cavity can displace SRH without the use of tissue plasminogen activator in some cases. Visual acuity after gas injection may be improved, making this treatment an alternative to evacuation of SRH with vitrectomy.

Aged↗
PubMed1998

Reassessment of H-reflex recovery curve using the double stimulation procedure.

We conducted two types of experiments to assess the validity of the H-reflex recovery test, using double stimulation to test soleus motoneuron pool excitability in healthy and spastic subjects. One type dealt with the mechanical effect of the conditioning H reflex on the ankle joint; the other type with the effect of change in reflex size. The mechanical effect was tested both with the ankle joint fixed (FX) and free to move (FR). Differences between FX and FR conditions commenced with relaxation of soleus muscle contraction by the conditioning H reflex. In the FR condition, abrupt facilitation occurred, and changed to marked depression. We conclude that specific facilitation and inhibition in the FR condition were secondary effects of group Ia inflows caused by the ankle extensor muscle stretching on relaxation. In some spastic patients as well as in controls, facilitation due to the mechanical effect in the FR condition was observed despite the FX condition. The effects of systematic changes on soleus H-reflex size were investigated at conditioning-test intervals of 80 ms, so as to avoid mechanical effects. When conditioning and test reflexes were the same size, the amount of recovery increased as the H-reflex size increased. Comparison of the relation between amount of recovery and H-reflex size, expressed as a percentage of Mmax, showed no significant difference between the two groups. We speculate that the stronger recovery of spasticity mentioned in previous literature may have resulted from the fact that relatively greater H reflexes were tested in those studies. In conclusion, the present study indicates that double stimulation is not appropriate for assessing spinal motoneuron pool "excitability increase" in spasticity.

Electric Stimulation↗
PubMed1998

Resection of malignant fibrous histiocytoma invading the thoracic aorta.

We report a case of surgically resected malignant fibrous histiocytoma which arose in the posterior mediastinum. Tumor removal with the required sufficient-margin and the resection of the affected thoracic aorta, led to flaccid paraplegia below the tenth thoracic level. This patient is now surviving with no evidence of recurrence at 42 months after the operation. Although malignant fibrous histiocytoma in the thorax generally shows a poor prognosis, this patient with complete resection could have a relatively long survival.

Aged↗
PubMed1998

Expression of bcl-2 homologue mRNAs in rat liver allograft: rejection-induced cell apoptosis is associated with upregulation of bax and bcl-xs expression.

Apoptosis is considered to play an important role in rejection of organ transplants, although the precise mechanism has not been elucidated. In this study, we screened for the expression of bcl-2 homologues (bcl-2, bax, bcl-xl, and bcl-xs) and Fas ligand (FasL) by RT-PCR method in grafts during acute rejection in rats following liver transplantation. Both bax and bcl-xs (inducers of apoptosis) mRNA levels increased steadily in the allografted group from postoperative day (POD) 2 to 8, while no remarkable changes of bcl-2 and bcl-xl expression (inhibitors of apoptosis) were recognized. Significant induction of FasL gene expression was observed in the allografted group on POD 4 and expression gradually decreased thereafter, although minimal FasL mRNA expression was seen in isografts. Our results indicated, for the first time, that rejection-induced cell apoptosis is closely associated with upregulation of bax and bcl-xs expression besides FasL, but not with down-regulation of bcl-xl.

Animals↗
PubMed1998

In vitro degradation of tropoelastin by reactive oxygen species.

The effects of reactive oxygen species (ROS) on elastin molecules (tropoelastin) were studied in vitro. ROS generated by ultraviolet A and hematoporphyrin rapidly degraded tropoelastin within 5 min. Their degradative activity was inhibited by the addition of NaN3. Treatment of tropoelastin with copper sulfate/ascorbic acid resulted in degradation of tropoelastin producing fragments of molecular weight 45, 30 and 10 kDa within 30 min. The degradation of tropoelastin was partially blocked by the addition of mannitol. ROS induced by the xanthine/xanthine oxidase system also degraded tropoelastin within 6 h. The degradation was blocked by catalase but not by superoxide dismutase (SOD). ROS generated by copper-ascorbate seems to be unique in that it cleaves relatively specific sites of the tropoelastin molecule. Thus ROS may play a degradative role in elastin metabolism which may cause the elastolytic changes or the deposition of fragmented elastic fibers in photoaged skin or age-related elastolytic disorders.

Ascorbic Acid↗
PubMed1998

A model of chronic hypotony in the rabbit.

BACKGROUND: Chronic hypotony is an important cause of functional failure after proliferative vitreoretinopathy (PVR) surgery even if the retina is successfully reattached. The purpose of this study was to create a relevant model of chronic hypotony in the rabbit. METHODS: Eighteen pigmented rabbits weighing 3-4 kg were used in our experiment. We performed pars plana lensectomy on 14 eyes of 14 rabbits with a fragmatome and a vitreous cutter. At the end of surgery, we injected 0.2 ml of phosphate-buffered saline containing 1,00,000 cultured rabbit dermal fibroblasts over the epiciliary area. As a control, we performed pars plana lensectomy alone on four eyes of four rabbits. The intraocular pressure (IOP) was measured on days 7, 14, 21, 28. Two rabbits were killed on day 7 and prepared for histology. Two additional rabbits were killed on day 14, and the remaining ten rabbits were killed on day 28. RESULTS: All 14 eyes following lensectomy and fibroblast injection had an IOP less than 5 mm Hg on each follow-up and a mean of 2.5 +/- 0.6 mm Hg (mean +/- SD) on day 28. Four control eyes with lensectomy alone had an IOP of 7.5 +/- 2.1 mm Hg on day 28 (P < 0.05). On gross examination, we identified a variety of pathologic changes, including the development of a fibrous translucent epiciliary membrane that caused distortion of ciliary processes, iridociliary adhesion and anterior displacement of the peripheral retina on day 28. Microscopic examination of eyes obtained on day 28 showed changes in the ciliary epithelium that included absence or atrophy of the non-pigmented ciliary epithelium, atrophy and cystic vacuolization of the pigmented ciliary epithelium, and interstitial edema of the ciliary body stroma. CONCLUSION: We have created a model of chronic hypotony with epiciliary membrane using cultured fibroblasts in the rabbit. This model may be useful to help elucidate the pathophysiology of chronic hypotony and to investigate potential treatments.

Animals↗
PubMed1998

Endobronchial metastasis from rectal adenocarcinoma: report of a case.

We herein report a case of late endobronchial metastasis after the resection of a primary rectal adenocarcinoma. A 51-year-old man underwent a resection of rectal adenocarcinoma. Five years postoperatively, he underwent a right sleeve upper lobectomy for a right endobronchial tumor. The resected tumor was diagnosed to be endobronchial metastasis from rectal adenocarcinoma. Therefore, the relationship between the two tumors was analyzed using deoxyribonucleic acid (DNA) flow cytometry and immunohistochemical staining. Endobronchial adenocarcinoma had strong homogeneous staining patterns and identical biochemical characteristics to rectal adenocarcinoma.

Adenocarcinoma↗
PubMed1998

Assignment of the ZIP kinase gene to human chromosome 19p13.3 by somatic hybrid analysis and fluorescence in-situ hybridization.

A cDNA for a putative member of the serine/threonine kinase family was cloned from an adult human testis cDNA library. The predicted translation product was identical to ZIP kinase, which has been suggested to play an important role in the induction of apoptosis. The messenger RNA was ubiquitously expressed in various tissues. The chromosomal location of the gene was determined by fluorescence in-situ hybridization and polymerase chain reaction-based analyses with both a human/rodent monochromosomal hybrid cell panel and a radiation hybrid mapping panel. This gene was mapped on the q13.3 region of chromosome 19.

Adult↗
PubMed1998

Cloning, expression analysis, and chromosomal localization of HIP1R, an isolog of huntingtin interacting protein (HIP1).

Huntington disease (HD) is an inherited neurodegenerative disorder which is associated with CAG expansion in the coding region of the gene for huntingtin protein. Recently, a huntingtin interacting protein, HIP1, was isolated by the yeast two-hybrid system. Here we report the isolation of a cDNA clone for HIP1R (huntingtin interacting protein-1 related), which encodes a predicted protein product sharing a striking homology with HIP1. RT-PCR analysis showed that the messenger RNA was ubiquitously expressed in various human tissues. Based on PCR-assisted analysis of a radiation hybrid panel and fluorescence in situ hybridization, HIP1R was localized to the q24 region of chromosome 12.

Adaptor Proteins, Signal Transducing↗
PubMed1998

Chromosomal assignment of the gene for human DNA-PKcs interacting protein (KIP) on chromosome 15q25.3-q26.1 by somatic hybrid analysis and fluorescence in situ hybridization.

We report the chromosomal location of the gene for DNA-PKcs interacting protein KIP. Based on fluorescence in situ hybridization and polymerase chain reaction (PCR)-based analyses with both a human/rodent monochromosomal hybrid cell panel and a radiation hybrid mapping panel, this gene was mapped to q25.3-q26.1 region on chromosome 15.

Calcium-Binding Proteins↗
PubMed1998

Visual function after foveal translocation with scleral shortening in patients with myopic neovascular maculopathy.

PURPOSE: To document the visual outcome after successful foveal translocation with intentional retinal detachment and scleral shortening for the treatment of myopic neovascular maculopathy. METHODS: Two severely myopic patients with subfoveal neovascular membranes underwent surgical translocation of the fovea to an area of healthy retinal pigment epithelium by means of scleral shortening and intentional retinal detachment. In the postoperative period, monocular and binocular visual function were studied. RESULTS: In one patient, best-corrected visual acuity improved from 20/150 to 20/20 postoperatively. In the second patient, acuity initially improved from 20/70 to 20/30. In both patients, the fixation point shifted from the site of the neovascular membrane. Oblique astigmatism developed and was managed with hard contact lenses. Diplopia and subjective torsion occurred transiently. Micropsia occurred in one patient. Peripheral fusion assessed by Worth four-dot testing after resolution of diplopia disclosed suppression in the nondominant eye in both cases. CONCLUSIONS: Foveal translocation with intentional retinal detachment and scleral shortening was useful in improving visual acuity in two patients with myopic neovascular maculopathy. Diplopia and aniseikonia occurred but resolved over time as suppression developed. This technique is promising for patients with myopic neovascular maculopathy.

Adult↗
PubMed1998

Anatomic and functional recovery of the fovea after foveal translocation surgery without large retinotomy and simultaneous excision of a neovascular membrane.

PURPOSE: To document the anatomic and functional recovery of the fovea after foveal translocation surgery with scleral shortening and simultaneous excision of a neovascular membrane in a patient with age-related macular degeneration. METHOD: Case report. RESULTS: The visual acuity of a 54-year-old woman with age-related macular degeneration improved from 20/200 to 20/50 after excision of subretinal neovascular membrane and foveal translocation surgery in the right eye. Fixation shifted inferonasally 0.6 disk diameters, corresponding to the direction of foveal translocation, as shown by scanning laser ophthalmoscope microperimetry. Postoperative optical coherence tomography through fixation disclosed normal foveal concavity and intact retinal pigment epithelium. CONCLUSION: Anatomic and functional recovery of the fovea was confirmed in a patient with age-related macular degeneration after foveal translocation surgery with scleral shortening and simultaneous excision of a neovascular membrane.

Female↗
PubMed1998

A distamycin A-inducible fragile site, FRA8E, located in the region of the hereditary multiple exostoses gene, is not involved in HPV16 DNA integration and amplification.

The rare fragile site is a specific point on a chromosome that is expressed as an isochromatid gap or break under certain conditions of cell culture and is inherited in a Mendelian codominant fashion. Five folate-sensitive fragile sites were cloned, and the molecular basis of fragile site mutation was shown to be a new class of mutation, called dynamic mutation, resulting from an allelic expansion of (CCG)n repeats. The mechanism responsible for other types of rare fragile sites, i.e., distamycin A-inducible and BrdU-requiring, is unknown, although cytogenetic studies suggested that these fragile sites play a mechanistic role in breakage and recombination and may also be integration and modification sites of foreign viral DNA genomes. A distamycin A-inducible fragile site, FRA8E, is mapped to 8q24.1 in which various loci implicated in genomic instability are located. Here we identified a YAC clone spanning both FRA8E and the hereditary multiple exostosis (EXT1) gene, using fluorescence in situ hybridization (FISH) analysis of a yeast artificial chromosome (YAC) contig. By using P1 clones as probes, the FRA8E locus was further localized to a 400-kb region including the EXT1 gene. Furthermore, the integration and amplification site of human papillomavirus 16 DNA in the ASCC (argyrophil small cell carcinoma) cells were shown not to coincide with FRA8E, but to be involved in an extensively broad genomic region of 8q24.1, including the c-myc gene.

Chromosome Fragile Sites↗
PubMed1998

Meiotic behaviours of chromosomes and microtubules in budding yeast: relocalization of centromeres and telomeres during meiotic prophase.

BACKGROUND: Meiosis is a process of universal importance in eukaryotic organisms, generating variation in the heritable haploid genome by recombination and re-assortment of chromosomes. The intranuclear movement of chromosomes is expected to achieve pairing and recombination of homologous chromosomes during meiosis. Meiosis in the budding yeast Saccharomyces cerevisiae has been extensively studied, both genetically and by molecular biology; here we report cytological observations of meiotic chromosomal events in this organism. RESULTS: Using fluorescence microscopy, we have examined the behaviour of chromosomes and microtubules during meiosis in S. cerevisiae. We first observed the dynamic behaviour of nuclei in living cells using jellyfish green fluorescent protein (GFP) fused with nucleoplasmin, a Xenopus oocyte nuclear protein. The characterization of nuclear movement in living cells was extended by an analysis of chromosomes and microtubules in fixed specimens. In addition, the nuclear localization of centromeres and telomeres was determined by indirect immunofluorescence microscopy in synchronous populations of meiotic cells. While telomeres remain in clusters of 5-8 throughout meiosis, centromeres change their nuclear localization dramatically during the progression of meiosis: centromeres are first clustered at a single site near the spindle-pole body before the induction of meiosis, and become scattered during the meiotic prophase. CONCLUSIONS: Our observations have demonstrated that nuclear and cytoskeletal reorganization take place with meiosis in S. cerevisiae. In particular, the distinct relocalization of centromeres during meiosis indicates a considerable movement of chromosomes within the meiotic prophase nucleus.

Cell Nucleus↗
PubMed1998

The lateral thigh V-Y flap for the repair of ischial defects.

The lateral thigh fasciocutaneous flap described by Maruyama et al in 1984 is a useful method for the repair of ischial and trochanteric defects. We clinically re-evaluated the potential vascular territory of the nutrient artery for this flap, i.e., the first profunda perforator, and have newly designed the postero-lateral thigh V-Y flap in the area including the proximal two-thirds of the posterior thigh. This flap was applied to five difficult or recurrent ischial defects, and satisfactory results were obtained in all cases. For the reconstruction of ischial defects, the postero-lateral thigh V-Y flap has the following advantages; the proximal and well-vascularised portion of the flap is inserted into the area of the previously excised pressure sore, and this flap can potentially be readvanced if a recurrent pressure sore should develop. A Z-plasty can be performed to prevent excessive tension on the skin closure at the junction of the V-Y advancement flap. The postero-lateral thigh V-Y flap can be considered one of the first-line options for both primary and recurrent ischial pressure sores.

Adult↗