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Biomedical subjects

N Yoshimura

Publications and source records attributed to N Yoshimura.

At least 469 records · Page 26Linked to original sources
PubMed1991

[Continuous hemofiltration vs hemodialysis for the acute renal failure after cardiovascular surgery].

Recently we have performed continuous hemofiltration (CHF) for the patients of acute renal failure after cardiovascular surgery. In this article, we discuss the effectiveness of CHF in the acute phase of renal failure after cardiovascular surgery compared with hemodialysis (HD). CHF group included 12 cases, and HD group included 19 cases. Two cases (16.7%) of CHF group and two cases (10.5%) of HD group were survived and discharged from hospital. Filtration volume of CHF (93.8 +/- 81.0 l) was significantly higher than that of HD (27.1 +/- 22.9 l), but filtration rate of CHF (410 +/- 87.4 ml/H) was significantly lower than that of HD (572 +/- 167 ml/H). Thus CHF removed excess water more gently and effectively than HD. Because the influence to the hemodynamics of CHF was much less than that of HD, we were able to start CHF (4.3 +/- 4.6 days after operation, BUN: 55.3 +/- 19.5 mg/dl), Cr: 3.95 +/- 0.63 mg/dl) significantly earlier than HD (7.8 +/- 4.1 days after operation, BUN: 113.1 +/- 29.4 mg/dl, Cr: 6.10 +/- 1.04 mg/dl). We needed high dose catecholamine or blood transfusion for the 11 cases (57.3%) of HD group during HD, but we needed them for only 1 case (8.3%) of CHF group. We concluded that CHF was safer and more useful than HD in the treatment of acute renal failure after cardiovascular surgery.

Acute Kidney Injury↗
PubMed1991

[Clinical studies of isosorbide dinitrate spray in postoperative patients].

We investigated the effect of isosorbide dinitrate (ISDN) single spray, containing 1.25 mg of ISDN, on cardiovascular and respiratory functions in eight postoperative patients. Concentrations of plasma ISDN and its metabolites were also investigated. Hemodynamic as well as blood gas studies were performed at 4 points (before, plus 10, 30 and 60 minutes after administration of ISDN) and the blood levels of ISDN and its metabolites were measured at 5 points (before, plus 5, 10, 30 and 60 minutes after administration of ISDN). Mean arterial pressure (MAP), mean pulmonary arterial pressure (MPAP), cardiac index (CI), pulmonary capillary wedge pressure (PCWP) and central venous pressure (CVP) decreased significantly and heart rate (HR) increased significantly at 10 and 30 minutes after the spray. The maximum changes observed of each parameters were MAP 7%, MPAP 22%, CI 9%, PCWP 33%, CVP 36% and HR 6%. Systemic and pulmonary vascular resistance indices did not change significantly throughout the study. PaO2 decreased significantly only at 10 minutes after the spray. Plasma ISDN concentration showed the maximum value of 56.3 ng.ml-1 at 5 minutes after the spray. After this value, the concentrations decreased rapidly. From this study, we conclude that single spray of ISDN is effective in decreasing preload promptly, but it is not effective in decreasing afterload. When using the spray, we should pay attention to pulmonary oxygenation.

Adult↗
PubMed1990

Simian T cell leukemia virus type-1-specific killer T cells in naturally infected African green monkey carriers.

Studies were made on the cellular immunity of 13 African green monkeys (Cercopithecus aethiops) naturally infected with Simian T cell leukemia virus type 1 (STLV-1), closely related to human T cell leukemia virus type 1. They were classified into 3 groups: 1) progressed carrier, 2) carrier, and 3) normal control. This grouping was made according to their hematologic features, i.e., number of peripheral white blood cells, existence of blastoid cells, presence of STLV-1 Ag on PBL and anti-STLV-1 antibody titers. None of the STLV-1 carriers showed any clinical signs, but STLV-1-specific killer T cells was detected in these PBL without in vitro stimulation. In vitro studies on Ag stimulation showed that the STLV-1-specific killer T cells had been fully activated in vivo, and that no augmentation of in vitro stimulation with STLV-1 Ag was necessary, and that primary in vitro stimulation of normal control PBL was not sufficient to induce specific killer T cells. In addition NK cell activity in PBL of infected monkeys were significantly higher than those in the uninfected.

Animals↗
PubMed1990

Suppression of human retinal pigment epithelial cell proliferation by hyperthermia.

To investigate the effects of hyperthermia on the proliferation of retinal pigment epithelial cells, in vitro growth of cultured human retinal pigment epithelial cells was studied following heat treatment. Forty-eight hours after plating, heat treatment of 37 degrees C and 41 degrees C to 45 degrees C for 30 or 60 minutes was given to retinal pigment epithelial cells. On days 1, 3, and 7, cell proliferation was evaluated by cell number counting and by DNA synthesis analysis. Hyperthermia gave statistically significant suppression of cell growth above 43 degrees C heat treatment and absolute cell number reduction above 44 degrees C on the seventh day. Deoxyribonucleic acid synthesis was significantly suppressed with 43 degrees C for 60 minutes or above 44 degrees C heat treatment. Hyperthermia may be a potential new therapy for proliferative vitreoretinopathy.

Cell Count↗
PubMed1990

Evaluation of radiation therapy for experimental proliferative vitreoretinopathy in rabbits.

We evaluated effects of radiation therapy on experimental proliferative vitreoretinopathy (PVR) induced in rabbits by double gas compression of the vitreous followed by homologous dermal-skin fibroblast injection. Electrons were irradiated in two rabbit groups. Group A animals (20 eyes) received 1000 cGy of irradiation immediately after cell injection; group B rabbits (9 eyes), which showed pucker formation 7 days after cell injection, were irradiated on that day at the same dose as was given to group A rabbit. Control animals (14 eyes) were not irradiated. The incidences of traction retinal detachment on day 28 were: control, 86%; group A, 10%; and group B, 22%. There were statistically significant differences between control and group A values and between control and group B values. No significant difference was found between group A and group B. Irradiation of 1000 cGy did not alter the histological picture of experimental PVR. The results showed that radiation suppressed the development of PVR when applied not only immediately after cell injection but also during pucker stages.

Animals↗
PubMed1990

Alpha 1-adrenergic receptor-mediated excitation from the locus coeruleus of the sacral parasympathetic preganglionic neuron.

Electrophysiological studies using alpha-chloralose anesthetized cats were performed to elucidate whether or not noradrenaline derived from the locus coeruleus (LC) activates sacral intermediolateral (IML) cell column neurons, from which the sacral parasympathetic neurons originate. LC stimulation induced a spike in the sacral IML cell column neurons (parasympathetic interneurons), which were not antidromically activated by stimulation of the pelvic nerve, with a mean latency of 65.4 +/- 4.64 msec (mean +/- S.E., n = 12). In the sacral IML cell column neurons (parasympathetic preganglionic neurons), which were antidromically activated by pelvic nerve stimulation with a mean latency of 5.32 +/- 1.23 msec, LC stimulation also elicited a spike with the mean latency of 67.9 +/- 4.53 msec (n = 7). Iontophoretic application of prazosin, an alpha 1-adrenergic blocking agent, inhibited spikes elicited by LC stimulation in 8 of 12 sacral parasympathetic interneurons tested, but no alterations of LC stimulation-induced spikes were seen during iontophoretic application of sotalol, a beta-blocking agent. In contrast, spikes elicited by LC stimulation in the sacral parasympathetic preganglionic neurons tested were not affected by iontophoretic application of either prazosin or sotalol. These results suggests that noradrenaline derived from the LC activities the parasympathetic interneurons in the sacral IML cell column through alpha 1-adrenergic receptors, thereby inducing excitation of the sacral parasympathetic neurons receiving impulses from the interneuron.

Animals↗
PubMed1990

Mediation of micturition reflex by central norepinephrine from the locus coeruleus in the cat.

We examined whether norepinephrine originating in the locus coeruleus mediates the micturition reflex in anesthetized cats. 6-Hydroxydopamine, a catecholamine neurotoxin, injected bilaterally into the locus coeruleus markedly decreased catecholamine fluorescence in the lesioned area and induced urinary retention after 72 to 84 hr. At this time, there was no or only slight contraction of the urinary bladder induced by its distension, while the contraction was noted before the treatment. However, phenylephrine, an alpha 1-receptor agonist, applied intrathecally in 6-hydroxydopamine-treated animals induced moderate bladder contraction. In sham-operated animals, the bladder contraction on its distension was inhibited by intrathecally applied prazosin, an alpha 1-receptor antagonist. Thus, in the micturition reflex, norepinephrine derived from the locus coeruleus acts on the alpha 1-adrenergic receptors in the sacral cord, and induces urinary bladder contraction via activation of the sacral parasympathetic preganglionic neurons.

Animals↗
PubMed1990

Medical and surgical complications of renal transplantation: diagnosis and management.

Renal transplantation is a common modality of therapy in end-stage renal failure, but it has the potential of developing many complications, both surgical and medical in nature. In transplantation surgery, more than in any other type of surgery, prevention of these complications is essential. This includes attention to many details, including optimum organ salvage, preservation, implantation, and postoperative care. Although infection has decreased in frequency and severity with the advent of antiviral and antibacterial agents, prevention, early diagnosis, and suitable treatment with appropriate antibiotic(s) will be necessary to obtain desirable results and to reduce morbidity and mortality. It should be stressed that although careful attention to the patients and adjustment of the immunosuppressive regimen may mitigate much of the gastrointestinal, hematologic, and osteogenic complications, high incidence of cancer of the skin and mucous membrane continues.

Bacterial Infections↗
PubMed1990

The effects of perioperative portal venous inoculation with donor lymphocytes on renal allograft survival in the rat. I. Specific prolongation of donor grafts and suppressor factor in the serum.

In order to investigate the in vivo functional role of the liver in the immune responses in organ transplantation, effects of perioperative portal venous p.v. administration of donor lymphocytes on renal allograft survival were tested in the rat kidney transplant model. Donor lymphocytes were prepared from BN (BN, RT-1n) or third-party DA (RT1a) rat spleens and lymph nodes and injected p.v. or intravenously to Lewis (LEW, RT-1l) hosts on the day of transplantation (day 0). Untreated LEW hosts rejected BN renal grafts at 7.8 +/- 0.6 days (n = 10). Intravenous administration of 1 x 10(8) BN cells to LEW hosts on day 0 caused a slight, but not significant, prolongation of renal allograft survival (MST = 9.5 +/- 3.0 days, n = 13, NS), whereas portal venous inoculation of 1 x 10(8) BN cells on day 0 remarkably prolonged renal graft survival to 22.2 +/- 5.3 (n = 10, P less than 0.01). The prolongation of graft survival was antigen-specific; the administration of 1 x 10(8) DA cells p.v. to LEW hosts did not prolong the survival of BN renal grafts (MST = 7.4 +/- 0.8, n = 5). Spleen cells from p.v. treated LEW hosts 10 days after transplantation had no suppressor effect on the one-way MLC reaction of normal LEW responder cells toward donor BN or third-party DA stimulators. On the other hand, when serum from p.v.-treated LEW hosts was added to MLC at a concentration of 3 per cent of total volume, it suppressed the MLC reaction toward donor BN cells by 71.6 per cent, but not toward third-party DA stimulators (-8.5 per cent suppression, NS). Histological examination of p.v.-treated LEW hosts at 10 days after transplantation revealed that the liver had normal lobular architecture without expansion of portal tracts and infiltration of inflammatory cells. On the other hand, the transplanted kidney demonstrated a moderate mononuclear cell infiltration around the artery without an interstitial hemorrhage. Moreover, adoptive transfer of the serum from p.v.-treated LEW rats into the virgin secondary LEW hosts significantly prolonged the graft survival of BN kidneys from 7.8 days to 18.9 +/- 5.5 days (P less than 0.01), but not third-party DA graft survivals (MST = 7.5 +/- 0.6 days), indicating that an antigen-specific tolerogenic factor was released into the circulation through the process of allogeneic cells in the liver.

Animals↗
PubMed1990

The effects of perioperative portal venous inoculation with donor lymphocytes on renal allograft survival in the rat. II. Phenotypic and functional analyses of graft-infiltrating cells.

Phenotype, donor-specific cytolytic activity, and helper activity to release cytokines of cells infiltrating within renal allografts of hosts rendered unresponsive by perioperative administration of donor lymphocytes via the portal vein (p.v.) were investigated in order to analyze the mechanism of prolongation of allograft survival. Graft-infiltrating cells (GIC) were obtained from Lewis (LEW, RT-1l) hosts inoculated perioperatively with 1 x 10(8) donor Brown-Norway (BN, RT-1n) lymphocytes p.v., a group that displays prolonged renal allograft survival (MST: 22.2 +/- 5.3 days, n = 10) compared with an uninoculated control group (MST: 7.8 +/- 0.6 days, n = 10, P less than 0.01). The percentages of cytotoxic/suppressor T cells (OX-8+) and Ia-positive cells (OX-6+) in GIC (23.1 +/- 4.4% and 9.0 +/- 2.0%, respectively) and in spleen cells (7.5 +/- 2.6% and 8.5 +/- 1.1%, respectively) from p.v.-inoculated LEW hosts on day 6 postgrafting were significantly lower than those of uninoculated control recipients (GIC: OX-8; 39.4 +/- 8.2%, OX-6; 23.0 +/- 1.9%. SP cell: OX-8; 21.6 +/- 9.9%, OX-6; 12.7 +/- 0.4%, P less than 0.05). Cytolytic activity of GIC from tolerant hosts on day 6 postgrafting toward donor blastoid lymphocytes was significantly decreased (19.0 +/- 1.2% at E/T = 50), compared with that from control allografts during ongoing rejection (51.5 +/- 5.3%, P less than 0.01). The amounts of in vitro cytokine production of GIC from tolerant hosts after mitogen stimulation were remarkably decreased (IL-2: 8.7 +/- 1.4 U/ml, IL-3: 15.4 +/- 0.6 U/ml, and BSF-2: 24.6 +/- 3.5 U/ml) than those of uninoculated control hosts during ongoing rejection (IL-2: 19.6 +/- 2.9 U/ml, IL-3: 22.2 +/- 2.7 U/ml, and BSF-2: 67.5 +/- 13.2 U/ml, P less than 0.05). These results demonstrated that activation of both Tc cells and Th cells was inhibited in the spleen and in situ in renal allografts following administration of donor lymphocytes through the portal vein.

Animals↗
PubMed1990

Chronological observations of histological changes, cytochrome oxidase activity and copper level in the brain of the postnatal brindled mouse.

Neuropathological and enzyme-histochemical studies were performed on brindled mouse hemizygotes (BMs) and normal littermates at the age of 2 days, 7 days, 11 days and 14 days, together with an investigation of their tissue copper levels. A greatly increased copper concentration was confirmed in the kidney and intestine and a greatly reduced concentration in the liver and brain of BMs. The copper concentration in the brain increased gradually with age in the normal littermates, whereas this did not occur in BMs. There was no significant difference in the tissue copper concentration between the cerebrum and the cerebellum-brainstem in BMs or in normal littermates. Light and electron microscopy of the BM brain revealed progressive neuronal degeneration in association with increased mitochondrial changes (ballooning and crista disintegration). Enzyme histochemical examinations demonstrated a progressive comparative decrease (i.e., an increased difference from normal) of cytochrome oxidase activity in the BM brain. These data suggest that progressive degeneration of the brain in Menkes' disease is attributable to mitochondrial degeneration caused by a comparative decrease of both copper concentration and cytochrome oxidase activity in the brain.

Animals↗
PubMed1990

A case of undifferentiated carcinoma arising in the mandible.

A case of undifferentiated carcinoma arising in the minor salivary gland is reported. Preoperative chemotherapy, surgery and postoperative immunotherapy were performed and good results were obtained for 15 months after surgery. However, metastasis to the lung occurred 18 months after surgery. The histologic diagnosis, clinical findings and origin of this tumor are discussed.

Carcinoma↗
PubMed1990

Down's syndrome in middle age. Topographical distribution and immunoreactivity of brain lesions in an autopsied patient.

A 45-year-old patient with Down's syndrome was autopsied. The brain, weighing 800 g, was small in size, and serial sections revealed generalized gyral atrophy and ventricular dilatation. In the gray matter, there was diffuse neuronal degeneration characterized by numerous neurofibrillary tangles (NFTs), senile plaques and frequent amyloid angiopathy. Histochemical and electron microscopical analyses of these lesions showed no qualitative difference from those in Alzheimer's disease. A topographical study of NFTs showed that they were numerous in the limbic system and cerebral neocortex. Various numbers of NFTs were seen in the olfactory bulb, thalamus, medial geniculate body, innominate substance, putamen, caudate, pallidum, central gray, reticular formation, certain midline nuclei of the brainstem, substantia nigra, red nucleus and dorsal vagal nucleus. This distribution pattern was not different qualitatively from that in Alzheimer's disease, and such a similarity was especially evident in the olfactory bulb, where many tufted and mitral cells as well as anterior olfactory nucleus cells showed NFTs. These common features of brain pathology in Down's syndrome and Alzheimer's disease may be due to a specific gene defect in both diseases.

Aging↗