Biomedical subjects

M Ohta

Publications and source records attributed to M Ohta.

At least 1,423 records · Page 79Linked to original sources

PubMedDate not supplied

Tumor necrosis factor-alpha regulates inducible nitric oxide synthase gene expression in the portal hypertensive gastric mucosa of the rat.

Increased expression of both nitric oxide synthase (NOS) and tumor necrosis factor-alpha (TNF-alpha) have been implicated in the hyperdynamic circulation of portal hypertension. Since overexpression of these proteins would affect gastric mucosal defenses, which are impaired in portal hypertension, we examined the expression and interrelationships of TNF-alpha and NOS in the gastric mucosa of portal hypertensive rats. Following staged portal vein ligation, gastric strips from portal hypertensive rats were incubated in organ culture medium with or without TNF-alpha antibody. The expression of TNF-alpha and NOS mRNAs was assessed by reverse transcription-polymerase chain reaction (RT-PCR) at baseline and after 1, 2, and 6 hours of incubation. RT-PCR demonstrated a threefold increase in inducible NOS mRNA and a 50% increase in TNF-alpha mRNA expression at baseline in portal hypertensive animals as compared to sham-operated animals. In tissue incubated with TNF-alpha neutralizing antibody, inducible NOS mRNA expression was significantly decreased by 40%, 70%, and 80% after 1, 2, and 6 hours, respectively. Since increased TNF-alpha and NOS production could potentially impair gastric mucosal defenses, our findings suggest a major role for these proteins in the development of portal hypertensive gastropathy.

Animals↗

PubMedDate not supplied

Portal hypertension triggers local activation of inducible nitric oxide synthase gene in colonic mucosa.

Recently a new clinical entity "portal hypertensive colopathy" has been reported. It involves vascular abnormalities and bleeding. Because nitric oxide may mediate these changes, we studied whether portal hypertension affects nitric oxide synthase in portal hypertensive colonic mucosa. In portal hypertensive and sham-operated rats the following studies were done: (1) colonic mucosal blood flow, (2) quantitative histologic examination, (3) reverse transcription-polymerase chain reaction for nitric oxide synthase mRNA, (4) nitric oxide synthase activity assay, and (5) immunostaining for nitric oxide synthase. In portal hypertensive rats, colonic mucosal blood flow and the number of submucosal veins were significantly increased in comparison to sham-operated rats. The mRNA expression and enzyme activity for inducible nitric oxide synthase (but not constitutive nitric oxide synthase) were significantly increased in portal hypertensive rats. Fluorescence signal intensity for inducible nitric oxide synthase in endothelia of mucosal and submucosal veins was significantly higher in portal hypertensive rats than in sham-operated rats. Portal hypertension activates inducible nitric oxide synthase gene and protein in colonic mucosal vessels. The excess of nitric oxide generated by overexpressed inducible nitric oxide synthase may play an important role in the development of vascular and hemodynamic abnormalities characterizing portal hypertensive colopathy.

Animals↗

PubMedDate not supplied

Analysis of medical needs on day 7 after the tsunami disaster in Papua New Guinea.

INTRODUCTION: Because of great intervening distances, international medical relief activities in catastrophic, sudden-onset disasters often do not begin until days 5-7 after the precipitating event. The medical needs of those affected and what public health problems exist in the community in the week after the tsunami disaster in Papua New Guinea(PNG) were investigated. METHODS: The Japan Medical Team for Disaster Relief (JMTDR) conducted investigative hearings at the District Office responsible for the management of the disaster, the Care Center, and the Hospitals in Aitape, Vanimo, and Wewak in PNG. RESULTS: The numbers of in-patients in the Aitape, Vanimo, and Wewak Hospitals, and in the Care Center in Aitape were 291, > 300, 68, and 104, respectively. The exact number of people affected was unknown at the Aitape District Office. There was no lack of medical supplies and drugs in the hospital, but the Care Center in Aitape did not have sufficient quantities of antibiotics. No outbreak of communicable disease occurred, despite the presence of risk factors such as the dense concentration of affected people and the constant prevalence of malaria and diarrhea. The water at Wewak General Hospital contained chlorine and was suitable for drinking, but that elsewhere contained bacteria. CONCLUSIONS: On about the 7th day after the event, the available information still was incomplete, and it was a time to shift from initial emergency activities to specialized medical care. Although no outbreak of communicable disease actually occurred, there was much anxiety about it because of the risk factors present. For effective medical care at this stage, it is essential to conduct a survey of actual medical needs that also include epidemiological factors.

Anti-Bacterial Agents↗

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Hospital disaster preparedness in Osaka, Japan.

PURPOSE: To investigate the adequacy of hospital disaster preparedness in the Osaka, Japan area. METHODS: Questionnaires were constructed to elicit information from hospital administrators, pharmacists, and safety personnel about self-sufficiency in electrical, gas, water, food, and medical supplies in the event of a disaster. Questionnaires were mailed to 553 hospitals. RESULTS: A total of 265 were completed and returned (Recovery rate; 48%). Of the respondents, 16% of hospitals that returned the completed surveys had an external disaster plan, 93% did not have back-up plans to accept casualties during a disaster if all beds were occupied, 8% had drugs and 6% had medical supplies stockpiled for disasters. In 78% of hospitals, independent electric power generating plants had been installed. However, despite a high proportion of power-plant equipment available, 57% of hospitals responding estimated that emergency power generation would not exceed six hours due to a shortage of reserve fuel. Of the hospitals responding, 71% had reserve water supply, 15% of hospitals responding had stockpiles of food for emergency use, and 83% reported that it would be impossible to provide meals for patients and staff with no main gas supply. CONCLUSIONS: No hospitals fulfilled the criteria for adequate disaster preparedness based on the categories queried. Areas of greatest concern requiring improvement were: 1) lack of an external disaster plan; and 2) self-sufficiency in back-up energy, water, and food supply. It is recommended that hospitals in Japan be required to develop plans for emergency operations in case of an external disaster. This should be linked with hospital accreditation as is done for internal disaster plans.

Accreditation↗

PubMedDate not supplied

Two forms of transforming growth factor-beta distinguished by multipotential haematopoietic progenitor cells.

Type-beta transforming growth factors (TGF-beta s) are polypeptides that act hormonally to control proliferation and differentiation of many cell types. Two distinct homodimeric TGF-beta polypeptides, TGF-beta 1 and TGF-beta 2 have been identified which show approximately 70% amino-acid sequence similarity. Despite their structural differences, TGF-beta 1 and TGF-beta 2 are equally potent at inhibiting epithelial cell proliferation and adipogenic differentiation. The recent immunohistochemical localization of high levels of TGF-beta in the bone marrow and haematopoietic progenitors of the fetal liver has raised the possibility that TGF-beta s might be involved in the regulation of haematopoiesis. Here we show that TGF-beta 1, but not TGF-beta 2, is a potent inhibitor of haematopoietic progenitor cell proliferation. TGF-beta 1 inhibited colony formation by murine factor-dependent haematopoietic progenitor cells in response to interleukin-3 (IL-3) or granulocyte-macrophage colony stimulating factor (GM-CSF), as well as colony formation by marrow progenitor cells responding to CSF-1 (M-CSF). The progenitor cell lines examined were approximately 100-fold more sensitive to TGF-beta 1 than TGF-beta 2, and displayed type-I TGF-beta receptors with affinity approximately 20-fold higher for TGF-beta 1 than TGF-beta 2. These results identify TGF-beta 1 as a novel regulator of haematopoiesis that acts through type-I TGF-beta receptors to modulate proliferation of progenitor cells in response to haematopoietic growth factors.

Cell Division↗

PubMedDate not supplied

Topographic distribution of aquaporin 2 mRNA in the kidney of dehydrated rats.

BACKGROUND: Stimulation of arginine vasopressin results in an immediate redistribution of water channels (aquaporin 2; AQP2) in the apical membrane of the collecting ducts, leading to water reabsorption. Water restriction for >/=24 h increases AQP2 proteins in the whole collecting duct which is highest in the inner medulla of the kidney, indicating that dehydration enhances synthesis of this protein. Although increased expression of AQP2 mRNA under this condition has been reported, the increased ratio of mRNA expression in the three regions of the kidney, cortex, outer medulla, and inner medulla, during the dehydration is still unclear. METHODS: We investigated the AQP2 transcripts using male Sprague-Dawley rats deprived of water for 24 h. Mimic cDNA for competitive polymerase chain reaction (PCR) was constructed by deleting 180 bp at the middle of a 780-bp partial PCR product for rat AQP2 cDNA. In situ hybridization of the kidney and Northern blotting of inner medulla were performed using a 60-bp oligo-cDNA probe which identified rat AQP2 transcripts in the collecting duct. RESULTS: Dehydration resulted in a significant increase in plasma osmolality and arginine vasopressin concentration and urinary osmolality. Competitive PCR demonstrated that dehydration increased AQP2 transcripts in all parts of the kidney, but was highest in the inner medulla. Northern blotting confirmed the high increased rate of AQP2 transcription in the inner medulla. In situ hybridization showed markedly intensified signals in the inner medulla of dehydrated rats. CONCLUSIONS: Our data indicate that dehydration increases the abundance of AQP2 transcripts which may be closely associated with enhancement in AQP2 protein synthesis reported previously. This topographically variable increase in transcription is considered to be one of the mechanisms involved in long-term regulation of water permeability in the collecting duct.

Animals↗

PubMedDate not supplied

E-PASS (The Estimation of Physiologic Ability and Surgical Stress) scoring system helps the prediction of postoperative morbidity and mortality in thoracic surgery.

OBJECTIVE: When a new scoring system, 'E-PASS', standing for the Estimation of Physiologic Ability and Surgical Stress that predicts the postoperative surgical risk by quantification of the patient's reserve and surgical stress applied to a population of general thoracic surgery patients, it should be investigated if this system could help us or not. METHODS: The comprehensive risk score (CRS) of the E-PASS and the clinical course were evaluated retrospectively in 282 consecutive patients with primary lung cancer (group A), and in 458 patients who underwent elective thoracic operations (group B). RESULTS: The morbidity and mortality rates in both group A and group B increased as the CRS increased. The CRS correlated significantly with the morbidity score, length of stay and cost of hospitalization. CONCLUSIONS: E-PASS scoring system may be useful in surgical decision-making and evaluating quality of care in patients who are tolerable for lung resection.

Adult↗

PubMedDate not supplied

Borrelia burgdorferi-seropositive chronic encephalomyelopathy: Lyme neuroborreliosis? An autopsied report.

A 36-year-old Japanese woman presented with progressive cerebellar signs and mental deterioration of subacute course after her return from the USA. Her serum antibody to spirochete Borrelia burgdorferi was significantly elevated. A necropsy 4 years after her initial neurological signs revealed multifocal inflammatory change in the cerebral cortex, thalamus, superior colliculus, dentate nucleus, inferior olivary nucleus and spinal cord. The lesions showed spongiform change, neuronal cell loss, astrocytosis and proliferation of activated microglial cells. The internal capsule was partially vacuolated and the spinal cord, notably at the thoracic level, was demyelinated and cavitated in the lateral funiculus. Microglial cells aggregated within and around the spongiform lesions and microglial nodules were present in the medulla oblongata. Use of Warthin-Starry stain demonstrated silver-impregnated organisms strongly suggesting B. burgdorferi in the central nervous tissues. The dentate nucleus and inferior olivary nucleus showed the most advanced lesions with profound fibrillary gliosis. Occlusive vascular change was relatively mild, and fibrous thickening of the leptomeninges with lymphocyte infiltrates was localized in the basal midbrain. The ataxic symptoms were due to the dentate and olivary nucleus lesions and mental deterioration was attributable to the cortical and thalamic lesions. Spongiform change, neuronal cell loss, and microglial activation are characteristic pathological features in the present case. The cerebellar ataxia and subsequent mental deterioration are unusual clinical features of Lyme neuroborreliosis. Spirochete B. burgdorferi can cause focal inflammatory parenchymal change in the central nervous tissues and the present case may be an encephalitic form of Lyme neuroborreliosis.

Adult↗

PubMedDate not supplied

Phase II study of vinorelbine in heavily previously treated small cell lung cancer. Japan Lung Cancer Vinorelbine Study Group.

Twenty-four previously treated patients with refractory or relapsed small cell lung cancer (SCLC) were entered into a prospective, multicenter phase II study. All 24 patients had been pretreated with some form of cisplatin-based chemotherapy. The median time of chemotherapy was 4.2 months (range 1.4-9.4 months). Patients were treated with a dose of 25 mg/m2 of vinorelbine weekly. Twenty-four patients were eligible for response and for toxicity. Partial response was observed in 3 out of 24 eligible patients (12.5%; 95% confidence interval, 2.7-32.4%). All 3 patients who responded had previous chemotherapy including vincristine. The most common toxicity was leukopenia (91.7%, 66.7% in WHO 3-4 grade) and anemia (70.8%, 20.8% in WHO 3 grade). Nonhematological toxicities were moderate and mild. These results support a two-state sequential study design of previously untreated patients for further phase II study in SCLC.

Aged↗

PubMedDate not supplied

Computed tomographic measurement of local cerebral blood flow by xenon enhancement.

The present technique was developed to overcome some of the disadvantages of measuring cerebral blood flow by radionuclide methods, such as poor localization of flow values and errors that result if the brain is pathological and local partition coefficients are altered. Serial CT scanning in humans was carried out during and after inhalation of 50 to 70% non-radioactive xenon. This diffusible gas with high atomic number enhanced gray matter first by 19 +/- 4 Hounsfield Units (HU) and later white matter by 24 +/- 4 HU. The regionality of flow values were cursored on CT pictures with a high spatial resolution of 4 X 4 mm (64 pixels) or 0.16cm2 X 0.5cm. In seven normal subjects, blood flow in gray matter was 82 +/- 11 ml/100gm/min and that in white matter 24 +/- 5ml/100gm/min. The partition coefficient (lambda), which is not obtainable in vivo by radionuclide scanning, was 0.9 +/- 0.1 for normal gray matter, 1.4 +/- 0.2 for normal white matter. Reduced flow, 13% in gray matter and 46% in white matter, was found in a large infarct secondary to complete occlusion of middle cerebral artery. In edematous tissue, blood flow was not significantly impaired in gray matter but was reduced to 29 to 54% in white matter. Local lambda values were reduced to 0.6-0.9 in edematous tissue, and 0.3-0.7 in infarction. This method appears to have several advantages over conventional isotope methods of measuring cerebral blood flow and provides useful clinical and research information.

Adult↗

PubMedDate not supplied

Hand-Schüller-Christian disease with occult diabetes insipidus, cardiac failure and renal dysfunction.

A 60-year-old man was diagnosed as Hand-Schüller-Christian disease due to the triad of exophthalmus, decalcification of the bone, and diabetes insipidus. He had xanthogranuloma on the face and a nuchal region, and unusual complications of ADH-resistant diabetes insipidus due to renal dysfunction, and chronic cardiac failure. Urine osmolality was hypotonic, but urine volume was within the normal limit, despite the presence of central diabetes insipidus. Hypophyseal, adrenal and thyroid function were not remarkable. The skin biopsy showed the infiltration of eosinophilic granuloma cells. Treatment with vincristine was effective to regress the xanthogranuloma. Diabetes insipidus was not treated because of the absence of polyuria and polydipsia.

Acute Kidney Injury↗

PubMedDate not supplied

Augmented antitumour effects of combined treatment with hyperthermia and tumour necrosis factor on human gastric cancer xenotransplanted into nude mice.

Hyperthermia combined with recombinant human tumour necrosis factor (rH-TNF) was evaluated for antitumour efficacy in vivo. Use was made of human gastric cancer tissues xenografted into nude mice. When 100, 300, 600, and 1200 units of rH-TNF (2.4 x 10(6) units/mg protein) were given twice intraperitoneally, tumour regression did not occur in any animal. In contrast, a remarkable suppression of tumour growth was observed when 600 and 1200 units of rH-TNF was given in combination with hyperthermia at 43.5 +/- 0.1 degrees C. No effects were evident with the regimen of 100 and 300 units of rH-TNF plus hyperthermia at the same temperature, as compared with evidence obtained with hyperthermia alone. The tumoral blood flow, determined by the hydrogen diffusion method, decreased immediately after hyperthermia alone or hyperthermia plus 1200 units of rH-TNF, whereas a slight decrease was seen after rH-TNF alone. When hyperthermia plus 1200 units of rH-TNF were given, there was a remarkable delay in reversion to pretreatment values of tumoral blood flow, as compared to findings with rH-TNF only or heat only. These results are discussed in relation to the antitumour and side-effects of rH-TNF.

Animals↗

PubMedDate not supplied

Metabolism of 11-deoxycortisol by cytochrome P450(11 beta): identification of reaction products by 1H-NMR and LC/MS-APCI method.

A hitherto-unidentified steroid produced in the reaction mixture of 11-deoxycortisol with bovine cytochrome P450(11 beta) reconstitution system was purified by repeated HPLCs, and subjected to 1H-NMR analysis. The result suggested that the new metabolite was 19-oxo-11-deoxycortisol. This was further confirmed by a new analytical technique using LC/MS equipped with atmospheric pressure chemical ion (APCI)-analyzer.

Atmospheric Pressure↗

PubMedDate not supplied

Clinical role of Tc-99m-MIBI scintigraphy in non-Hodgkin's lymphoma.

This study was designed to investigate the relationship between Tc-99m-hexakis-2-methoxyisobutylisonitrile (MIBI) scintigraphy and outcome of treatment in patients with non-Hodgkin's lymphoma (NHL). Forty-five patients with NHL were studied with Tc-99m-MIBI before any treatment. Images of the lesions were obtained at 20 min and 2 h after radionuclide administration. Visual semi-quantitative interpretation was performed for Tc-99m-MIBI (grade 0-4) scintigraphy. Patients underwent 3-5 cycles of CHOP chemotherapy with/without involved field radiotherapy for large tumors. Their responses to treatment were evaluated at the end of chemotherapy and during the follow-up period. Forty of 45 patients (89%) showed abnormal uptake of Tc-99m-MIBI. There was no correlation between intensity of MIBI accumulation and response to chemotherapy. However, patients with negative or decreased MIBI activity 2 h after radionuclide administration showed worse response to chemotherapy compared to those with continued MIBI activity. MIBI activity could not predict the development of relapse in the follow-up study. In this study, the number of patients was small and we could not reach definite conclusions. However, we think that MIBI scintigraphy is not valuable for predicting the chemotherapy outcome in patients with NHL.

Adult↗

PubMedDate not supplied

Systemic effects of ethanolamine oleate in analbuminemic rats.

BACKGROUND/AIMS: The present study was an attempt to clarify whether only serum albumin inactivates ethanolamine oleate (EO) in vivo and whether EO has an adverse effect on the lung, kidney, and liver in the presence of analbuminemia. METHODOLOGY: Fifty-five female Nagase Analbuminemia Rats (NAR) and 55 female Sprague-Dawley Rats (SDR) were injected with 5% EO in the left femoral vein. Changes in respiratory, renal, and hepatic function and the extent of hemolysis following the injection of the EO were examined. RESULTS: In both groups, a transient but significant increase was seen in serum hemoglobin at up to 1 hour after injection of EO. No significant changes in PaO2, PaCO2, blood urea nitrogen, or serum creatinine following injection of EO were seen in either group. The total bilirubin significantly increased within 30 min in the SDR group, but this increase was prolonged for 5 days in the NAR group. Glutamic pyruvic transaminase (GPT) increased for 12 hours in the NAR group, while no change was seen in the SDR group. CONCLUSIONS: These observations suggest that EO may have hepatotoxic effects, that serum albumin may afford protection, and that other humoral substances which inactivate EO, including serum globulin, may be present.

Alanine Transaminase↗

PubMedDate not supplied

Laparoscopic splenectomy: the latest modern technique.

BACKGROUND/AIMS: Recent advances in technical instruments have resulted in increased safety and simplicity in laparoscopic surgery. The purpose of this article is to introduce our latest operative techniques for laparoscopic splenectomy. METHODOLOGY: The patient is placed in the right semidecubitus position and the gastrosplenic ligament including the short gastric vessels was performed by using an ultrasonically activated scalpel. The splenic artery and vein were resected at the splenic hilum with an autosuture device. The electromechanical morcellator was used to remove the spleen. RESULTS: The laparoscopic splenectomy was successfully performed in all 74 patients from 1992-1997. There was no deaths related to the operation. Conversion to open surgery with a small incision of 5 cm was required in one patient with advanced liver cirrhosis and portal hypertension and 45 patients with portal hypertension. CONCLUSIONS: A laparoscopic splenectomy is considered to be a safe and feasable modality for the treatment for hematologic disorders of both the spleen and other benign tumors.

Humans↗

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Disasters↗

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Surgical treatment of a patient with idiopathic portal hypertension and hepatic encephalopathy.

Idiopathic portal hypertension is clinically characterized by splenomegaly and portal hypertension. Hepatic encephalopathy is rare in cases with idiopathic portal hypertension. In a 59-year-old man with recurrent hepatic encephalopathy for one year, a large splenorenal shunt was detected in the computed tomography and angiography, and liver biopsy revealed a portal fibrosis consistent with idiopathic portal hypertension. Devascularization of the upper stomach, splenectomy and closure of the splenorenal shunt were done. The patient has had no experience of encephalopathy since the operation even without drug treatment. Surgery should be considered for treatment of chronic hepatic encephalopathy in patients with idiopathic portal hypertension and portosystemic shunts.

Angiography↗