Biomedical subjects

H Nakata

Publications and source records attributed to H Nakata.

At least 145 records · Page 8Linked to original sources

PubMed1995

Early blood-brain barrier disruption after high-dose single-fraction irradiation in rats.

We studied the effect of high-dose single-fraction irradiation on the permeability of the blood-brain barrier (BBB) in rat brains. Immunohistochemistry with an antibody to serum albumin was used as a sensitive method for detecting the extravasation of endogenous serum components. Extravasation of albumin was detected as early as 1 day after irradiation with 20 or 40 Gy. Immunoreactivity reached its maximum after 3 days, gradually decreased during the following few weeks and had disappeared by day 30. Extravasation was much greater after irradiation with 80 Gy and continued to increase during the whole period of the experiment (6 days). Disruption of BBB this early after irradiation has not been previously documented. The time course of observed serum albumin extravasation, however, agrees well with the previous ultrastructural evidence for increased BBB permeability after irradiation with 27 Gy in monkey brains. This transient impairment of BBB may contribute to the reversible neurological symptoms after radiosurgery. It may also allow drugs that normally not pass the BBB to do so and thus disperse in the brain when administered at this time.

Animals↗

PubMed1995

Serum antibody against Helicobacter pylori assayed by a new capture ELISA.

We developed a highly specific detection technique for serum antibody, using a monoclonal antibody to a specific antigen of Helicobacter pylori. A monoclonal antibody preparation that reacted with the 54-kDa molecule of H. pylori antigens was obtained. Using this preparation, an antigen-capture enzyme-linked immunosorbent assay (ELISA) was established by fixation of the monoclonal antibody, followed by reaction with sonicated whole cell antigens. The serum antibody titers of patients with gastritis and peptic ulcers were significantly higher than control titers, and the antibody titer correlated with the histological severity of gastritis. Patients positive for H. pylori by bacterial culture had higher titers than H. pylori-negative patients. Our new ELISA may be useful for the diagnosis of H. pylori infections and for evaluation of the severity of gastric inflammation.

Antibodies, Bacterial↗

PubMed1995

Establishment of primary epithelial cell culture from elutriated rat gastric mucosal cells.

Proliferating cells in the gastric mucosal epithelium were successfully enriched by counterflow elutriation in a medium-sized cell fraction. When inoculated on culture plates coated with E-C-L cell attachment matrix, these cells differentiated into mucus-producing cells after reaching confluence. Northern blot analysis did not detect any transcript of the proton pump, histidine decarboxylase, somatostatin, or pepsinogen I, indicating the absence of parietal, ECL, D, and chief cells in the confluent monolayer. These mucus-producing cell monolayers that respond to various growth factors may be a suitable model with which to investigate the function of gastric mucus cells in vitro.

Animals↗

PubMed1995

Copresence of prostaglandin EP2 and EP3 receptors on gastric enterochromaffin-like cell carcinoid in African rodents.

BACKGROUND & AIMS: Prostaglandins (PGs) have important roles in the regulation of gastric acid secretion. The aim of this study was to examine the possible presence of PG receptors on the gastric enterochromaffin-like (ECL) carcinoid of Mastomys natalensis, which might be a useful model of normal ECL cells. METHODS: A [3H]PGE2 binding experiment was performed by using the ECL tumor membrane, and intracellular signal transduction was studied in the cells. In addition, Northern blot analysis using EP2 and EP3 receptor complementary DNAs was conducted. RESULTS: [3H]PGE2 specifically bound to the tumor cell membrane, and the binding was displaced by various PGs with a potency order of PGE1 = PGE2 > enprostil > PGF2 alpha. Although PGE1 and PGE2 stimulated 5'-cyclic adenosine monophosphate (cAMP) production, neither PGF2 alpha nor enprostil had any effect. On the other hand, all of PGE1, PGE2, PGF2 alpha, and enprostil attenuated the forskolin-induced cAMP production. Moreover, enprostil inhibited histamine release induced by forskolin. However, on pertussis toxin treatment, PGE2 paradoxically enhanced the forskolin-induced increase of cAMP production. Finally, the presence of EP2 and EP3 receptor messenger RNAs was confirmed by RNA blot analysis. CONCLUSIONS: The ECL carcinoid tumor cells of Mastomys seem to possess two subtypes of PGE receptor: EP2 linked to cAMP production and EP3 coupled with inhibitory guanosine 5'-triphosphate-binding proteins mediating the inhibition of cAMP production.

Animals↗

PubMed1995

Gene expression of keratinocyte and hepatocyte growth factors during the healing of rat gastric mucosal lesions.

BACKGROUND & AIMS: The factors that stimulate the growth of gastric mucosal cells during gastric mucosal healing are not completely understood. This study was designed to investigate the gene expression of keratinocyte growth factor (KGF) and hepatocyte growth factor (HGF) in the healing of gastric mucosal lesions. METHODS: Northern blot analysis and reverse-transcription polymerase chain reaction were used to show HGF and KGF messenger RNA. RESULTS: Transcripts of HGF and KGF were not shown in rat gastric mucosal epithelium but were found in submucosal and muscular layers under normal conditions. When acute gastric mucosal lesions were induced by indomethacin treatment, expression of HGF messenger RNA was augmented in submucosal, muscular, or serosal layers, whereas the transcript of KGF was not influenced. When rat gastric mucosal epithelial cell line RGM1 and rat gastric mucosal primary culture cells were incubated with HGF or KGF, their proliferation was enhanced. CONCLUSIONS: The results showed increased gene expression of HGF together with constant production of KGF during gastric mucosal healing.

Acetates↗

PubMed1995

CT of pulmonary metastases with pathological correlation.

CT, including high-resolution CT, has become an essential means of imaging to evaluate pulmonary metastases. The underlying pathological processes of pulmonary metastases can be observed well on CT images, but they are not always specific. Several important CT features correlate with histopathological findings: (1) margin of nodule; (2) hemorrhage accompanying a metastatic nodule; (3) calcification; (4) cavitation; (5) sterilized metastasis; (6) small metastatic nodules in the lobules; (7) lymphangitic carcinomatosis; (8) tumor emboli; and (9) pleural metastases. For reasonable use of CT in pulmonary metastases, these various CT manifestations and their limitations must be understood.

Humans↗

PubMed1995

Efficacy of lansoprazole and amoxicillin in eradicating Helicobacter pylori: evaluation using 13C-UBT and Monoclonal H. pylori antibody testing.

Combination therapy with lansoprazole (LPZ) and amoxicillin (AMPC) was administered to eradicate Helicobacter pylori. Changes in eradication rates were monitored and serum antibody titers, levels of pepsinogens I and II (PI and PII), and gastrin were measured. The 40 subjects were divided into two groups: one group received LPZ 30 mg alone, and the other received LPZ 30 mg and AMPC 1,500 mg concomitantly. AMPC was administered for 2 weeks before completion of LPZ treatment. Maintenance therapy was cimetidine 400 mg. The presence of H. pylori was evaluated using the urea breath test (UBT). The clearance rate was 12.5% and the eradication rate was 0% in the LPZ group, and the corresponding rates in the LPZ with AMPC group were 41.6 and 25.0%, respectively. Serum monoclonal H. pylori antibody titers decreased in patients in whom bacterial eradication had been achieved. Serum PI was significantly reduced in those patients in whom eradication had been achieved. Serum PII and gastrin levels also tended to decrease in patients in whom eradication had been achieved, but no such changes were observed in the other patients. Further research into drug treatment and evaluation methods for bacterial eradication is required.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed1995

Increased frequency of apolipoprotein epsilon 2 allele in non-insulin dependent diabetic (NIDDM) patients with nephropathy.

The genetic polymorphism of apolipoprotein E (epsilon 2, epsilon 3 and epsilon 4) is associated with lipid abnormalities. It has been suggested that lipid abnormalities may contribute to the development and progression of kidney diseases, including diabetic nephropathy. Thus, in this study we compared the apo E allele frequencies among 146 non-insulin-dependent diabetic (NIDDM) patients with nephropathy, 135 NIDDM patients without nephropathy and 576 of the general Japanese population. The epsilon 2 allele frequency was significantly higher in diabetic patients with nephropathy (7.2%) and with renal failure (9.7%) than in diabetic patients without nephropathy (2.6%) and in the general Japanese population (3.7%). It is concluded that there is a possibility that the epsilon 2 allele is associated with nephropathy in NIDDM.

Alleles↗

PubMed1995

Intramuscular myxoma with fibrous dysplasia: a report of two cases with a review of the literature.

Two cases are reported of a rare association of intramuscular myxoma with fibrous dysplasia in a 70 and 40 year old Japanese woman, respectively. One of them had a solitary intramuscular myxoma, and the other patient suffered from two intramuscular tumors that had been initially misdiagnosed as myxoid liposarcoma. Only 24 cases of this kind of association have been recorded in the literature. This association should be taken into consideration to avoid inappropriate treatment, when cases of myxoid soft tissue tumor with a bone lesion are encountered.

Adult↗

PubMed1995

Idiopathic chronic eosinophilic pneumonia associated with noncaseating epithelioid granulomas.

A 34 year old Japanese woman was referred to our university hospital due to pulmonary opacities and bilateral hilar lymphadenopathy on chest X-ray. She also had uveitis, erythematous skin nodules, and oral and genital ulcers. Laboratory data showed eosinophilia in the circulation and bronchoalveolar lavage fluid. Histological study revealed massive eosinophilic infiltration and noncaseating epithelioid granulomas in the lung and mediastinal lymph node, without evidence of vasculitis. Pulmonary opacities, lymphadenopathy, and blood eosinophilia promptly improved with corticosteroid therapy. In this patient, idiopathic chronic eosinophilic pneumonia overlapped with features of sarcoidosis and Behçet's disease.

Adult↗

PubMed1995

Malignant fibrous histiocytoma presenting as an endobronchial polyp of the carina.

A 64 year old man was admitted to hospital due to dyspnoea and stridor. A peduncular polyp of the carina was found at bronchoscopy. Histological examination of the tumour after resection with endoscopic electronsurgery revealed malignant fibrous histiocytoma (MFH) of myxoid type. With endoscopic neodymiumyttrium aluminium garnet (Nd-YAG) laser surgery, residual tumour was eliminated. To our knowledge this is the first case with malignant fibrous histiocytoma appearing as a polyp of the carina.

Bronchial Neoplasms↗

PubMed1995

Relationship between respiratory muscle strength and lean body mass in men with COPD.

It has been suggested that low body weight may be associated with decreased respiratory muscle function in COPD, but the precise mechanism is not known. Since body compositional change inevitably accompanies body weight change, we decided to study the possible relationship between respiratory muscle strength and body composition in patients with COPD. We studied respiratory muscle strength, pulmonary function, and body composition in 24 Japanese male patients with COPD. Patients were divided into two groups according to their body weight (group A, body weight lower than 80% of ideal body weight vs group B, 80% or more) and a comparison was made together with age-matched controls (group C). Maximal inspiratory mouth pressure (PImax) and maximal expiratory mouth pressure (PEmax) were measured by a previously reported method. Body compositional analysis was performed using dual energy x-ray absorptiometry (DXA; Norland XR26). It showed significantly lower fat body mass (FAT), FAT/body weight%, and lean body mass (LEAN) in group A than those in group B. The PImax in group A was significantly lower than that in group B and C (44.2 +/- 13.8, 76.4 +/- 29.9, and 88.6 +/- 18.1 cm H2O, respectively). PEmax in group A was also significantly lower than that in group B and group C (61.9 +/- 20.1, 86.7 +/- 26.8, and 90.4 +/- 17.6 cm H2O, respectively). Both PImax and PEmax were significantly correlated with LEAN (r = 0.656, r = 0.591, p < 0.01, respectively) in patients with COPD. These results show that respiratory muscle strength is closely associated with body weight and lean body mass in patients with COPD. The present approach to compare respiratory muscle strength with lean body mass should be useful for studying the mechanism of respiratory muscle weakness in patients with COPD.

Absorptiometry, Photon↗

PubMed1995

Malignant hemangioendothelioma of the aorta.

We present a rare case of aortic malignant hemangioendothelioma with a mural growth pattern in which the endothelial nature was confirmed by immunohistochemical demonstration of Factor VIII-related antigen. Aortic sarcomas and malignant hemangioendotheliomas in the literature are reviewed.

Aorta↗

PubMed1995

Systemic capillary leak syndrome associated with multiple myeloma of IgG kappa type.

A case of systemic capillary leak syndrome in a 67-year-old woman is reported. The patient suddenly presented with severe edema and hypotension associated with an increased hematocrit and a decreased level of serum albumin, suggesting capillary hyperpermeability. The patient had IgG kappa monoclonal gammopathy in association with not only a slight increase in plasma cells in the bone marrow but also several punched out lesions in the skull, indicating multiple myeloma. Although most of the cases of systemic capillary leak syndrome reported previously were accompanied by monoclonal gammopathy, this appears to be the first case in which capillary leak syndrome developed in a patient with multiple myeloma.

Aged↗

PubMed1995

Distortion-product otoacoustic emissions in experimentally induced hydropic ears.

The postoperative changes of distortion-product otoacoustic emissions (DPOAEs) and cochlear potentials were examined using 15 albino guinea pigs in which endolymphatic hydrops was induced by obliterating the endolymphatic sac. DPOAEs (geometric mean: 4,6 and 8 kHz) were measured once before and every week after surgery. At the 2nd (n = 5), 4th (n = 5) and 12th (n = 5) postoperative weeks, endocochlear potential (EP) and compound action potential (CAP) were measured. Although the reduction in DPOAEs at 8 kHz was first detected at the 12th week, the amplitude of DPOAEs at 4 and 6 kHz was already reduced at the first week and decreased gradually thereafter. In contrast to these results, the CAP threshold was not elevated at the 2nd week and a slight increase was first detected at the 4th week. The results obtained in the present study suggest that DPOAEs are more sensitive than CAP in detecting the presence of hydrops.

Action Potentials↗

PubMed1995

Effect of acoustic overstimulation on the hydropic ear.

The effect of acoustic overstimulation (2 kHz pure tone) on the compound action potential (CAP) threshold was investigated at frequencies ranging from 2 to 16 kHz using albino guinea pigs, both normal and with experimentally induced endolymphatic hydrops. The hydropic ears were less susceptible to acoustic overstimulation than the normal ears. As the CAP threshold was raised, the frequency exhibiting the greatest CAP threshold shift increased in both animal groups. The tendency was more noticeable in the hydropic ears than in the normal ears. These results are discussed from the aspect of cochlear hydrodynamics.

Action Potentials↗

PubMed1995

[Thymic lymphoid hyperplasia of myasthenia gravis patients: correlation with clinical features and efficacy of thymectomy].

Thirty nine thymus tissues from myasthenia gravis patients without thymoma who underwent extended thymectomy were evaluated on thymic lymphoid hyperplasia with special emphasis on clinical features and the efficacy of thymectomy. Of 39 patients, 31 were women, but 3 of 7 patients without thymic lymphoid hyperplasia were men. The hyperplastic index of the thymus correlated largely with serum anti-Ach-R antibody titers before surgery. Age, myasthenic type and preoperative duration of the symptoms were almost unrelated to the hyperplastic change in the thymus. The effect of thymectomy was more remarkable in the patients with the hyperplastic thymus than that in them without it, who obtained still no remission after surgery, although the remission rate of them with it reached to 25%. Of 7 patients without the hyperplastic thymus, 4 had no detectable antibody to acetylcholine receptor, whereas in 32 patients with it only 2 were seronegative. This negative immunological factor might make adverse response to thymectomy. Although unfavorable response to thymectomy were observed in the patients without the hyperplastic thymus, most of them were significantly improved through a supplementary treatment with steroid after surgery. Thymectomy was a favorable treatment for myasthenia gravis patients with thymic lymphoid hyperplasia, whereas in them without it the result of thymectomy was unsatisfactory.

Adolescent↗

PubMed1995

Pulmonary cryptococcal infection in an untreated patient with sarcoidosis.

A 36-year-old housewife was referred to our hospital in March, 1993. Her chest X ray films showed mediastinal and bilateral hilar lymphadenopathy. She was confirmed to have pulmonary sarcoidosis. We did not administer any medications for her. Four months after the diagnosis of sarcoidosis, opacities with cavitation appeared on the chest X ray. Histologic findings of lung biopsy specimens revealed granulomas with the existence of encapsulated Cryptococci. We administered an antifungal drug, itraconazole. The opacities were greatly improved by the medication. We report focal pulmonary cryptococcal infection in an untreated patient with sarcoidosis.

Adult↗