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Biomedical subjects

N Hamada

Publications and source records attributed to N Hamada.

At least 19 recordsLinked to original sources
PubMed1992

[Detection and serotyping of HRVs collected from children with acute gastroenteritis in winter of 1986 to 1991].

Fecal samples from sporadic acute gastroenteritis patients who visited at a pediatrician during five consecutive winter seasons in Kurume City located at north part of Kyushu district. Fecal samples were subjected to detection of rotavirus and other viruses and study of yearly changes in serotype of rotavirus. The rate of group A rotavirus positives in third winter and other consecutive winters were 12.5%, 40 to 65%, respectively. 60% specimens were successfully serotyped: 58% was serotype 1.22% was serotype 3.6% was serotype 2, and 14% was serotype 4. The dominant serotype in first, fourth and fifth winter was type 1. However in second winter each serotype of rotavirus was almost equally detected. During five consecutive winters six patients visited at the same pediatrician twice more than two months interval. They all had acute gastrointestinal symptoms. In six patients rotavirus was detective just once.

Acute Disease↗
PubMed1992

Radioimmunoassay for calcitonin gene-related peptide and its measurement in sera of patients with thyroid disease.

To investigate serum levels of calcitonin gene-related peptide (CGRP), we developed a sensitive radioimmunoassay (RIA). RIA for CGRP in serum can present some problems: the serum may degradate the tracer during incubation and suppress the antigen-antibody reaction. We avoided these problems by using aprotinin and CGRP-free serum instead of a buffer for the standard curve. We detected serum CGRP in all 39 healthy subjects when CGRP-free serum was not used for the standard curve, but 34 of these subjects had serum CGRP levels below the detection limit (less than 80 pmol/l) when CGRP-free serum was used for the standard curve. We defined the normal range for serum CGRP as below 100.8 pmol/l, which was the maximum level found in the healthy subjects. We studied serum levels of this peptide in patients with thyroid diseases, because the thyroid may be one origin of circulating CGRP. Four of 10 patients with medullary thyroid carcinoma had elevated serum levels of CGRP. Seven of 24 patients with subacute thyroiditis had elevated serum levels of CGRP, but at least one year after clinical recovery, CGRP was undetectable in all. Seven of the 37 patients with hypothyroidism had elevated serum levels of CGRP. None of the patients with hyperthyroidism, adenomatous goiter, thyroid adenoma, or thyroid carcinoma had elevated serum CGRP levels. It is necessary to use a standard curve obtained by the addition of aprotinin and CGRP-free serum to the assay standards to measure serum CGRP levels. Some patients with subacute thyroiditis, hypothyroidism, or medullary thyroid carcinoma had elevated serum CGRP levels.

Adult↗
PubMed1992

Kawasaki disease complicated by acute myocardial infarction due to thrombotic occlusion of coronary aneurysms 19 years after onset.

A 25-year-old man with a history of Kawasaki disease from the age of 7 had acute inferior myocardial infarction. Emergency right coronary arteriogram showed successive coronary aneurysms at the proximal to middle portion of the right coronary artery, and total occlusion at the proximal segment. Intracoronary thrombolysis was performed and the right coronary artery was recanalized. On left coronary arteriography, coronary aneurysms and mild localized stenoses at the inlet and outlet of the aneurysms were found. It was suggested that the myocardial infarction was caused by thrombotic occlusion of coronary aneurysms complicated with Kawasaki disease.

Adult↗
PubMed1992

[Myocardial perfusion and left ventricular function during exercise evaluated by 201Tl myocardial scintigraphy and 99mTc radionuclide ventriculography in patients treated with PTCA].

To evaluate the effects of percutaneous transluminal coronary angioplasty (PTCA), we investigated myocardial ischemia and left ventricular function during exercise before and after successful PTCA in 30 patients. We used extent and severity scores of 201thallium (201Tl) exercise myocardial scintigraphy to assess myocardial ischemia and determined global and regional left ventricular ejection fraction (EF and REF) of 99mTc-RBC exercise radionuclide ventriculography to assess left ventricular function. The extent and severity scores of stress images were significantly less after PTCA than before PTCA. The scores of the redistribution images were unchanged before and after PTCA. Global EF during exercise was significantly higher after PTCA than before PTCA. There was no difference in resting global EF between before and after PTCA. Myocardial ischemia induced by exercise was semi-quantitatively analyzed as transient perfusion defect with severity score. Severity score was significantly less after PTCA than before PTCA. delta EF, which was obtained by subtraction of resting global EF from exercise one, was significantly higher after PTCA than before PTCA. However, the degree of improvement in myocardial ischemia and left ventricular function varied from patient to patient. In 17 patients with one-vessel left anterior descending artery disease, delta REF, which was determined by subtracting resting regional EF from exercise one, was significantly higher in septal and apical segments after PTCA than before PTCA. Myocardial ischemia and left ventricular function under exercise were alleviated by PTCA. However, the degree of improvement varied from patient to patient and it might have been affected by various factors including coronary dissection, edema, thrombus, restenosis, spasm, side branch stenosis or occlusion, distal thrombus, and myocardial hibernation.

Aged↗
PubMed1992

[Left-sided gallbladder with accessory liver accompanied by intrahepatic cholangiocarcinoma].

A 66-year-old female of left-sided gallbladder with accessory liver was reported. These anomalies were recognized during an operation of intrahepatic cholangiocarcinoma. The gallbladder was located with its liver bed at the lateral segment of the liver. The cystic duct branched from the right side of the common bile duct, and turned in hairpin form in the left direction. The cystic artery branched from the right hepatic artery. There was the accessory liver on the wall of the gallbladder. A careful identification of the cystic duct and the portal vein was advocated in surgery of the left-sided gallbladder.

Adenoma, Bile Duct↗
PubMed1992

[A case report of bone metastasis diagnosed by MRI and effectively treated with UFT after breast conserving therapy for breast cancer].

A 66-year-old woman with left breast cancer (medullary carcinoma; T1cN1M0; Stage II A) was treated with breast conserving therapy combined with lumpectomy, radiotherapy, chemotherapy and endocrine therapy beginning in March, 1990. She complained of back pain and was diagnosed as having bone metastasis to the lower thoracic spine by bone scintigram and MRI examination in September, 1990. Oral administration of UFT (300 mg/day) was started, and 5 months later, back pain disappeared; nineteen months later, no definite findings of bone metastasis were observed on bone scintigram and MRI. It was concluded that long-term oral administration of UFT is an effective remedy for bone metastasis after breast conserving therapy for breast cancer.

Administration, Oral↗
PubMed1992

[An experimental study on the rejection phenomenon of multi-visceral allografts in pigs].

Multi-visceral allografts including the liver, pancreas and gastrointestinal tract were transplanted in 10 pigs. Eight of them survived for 7 to 21 days. Histopathological changes were studied in the liver, pancreas and gastrointestinal tract. An en bloc transplantation revealed no particular course after transplantation than those individual organ transplantation. The status of rejection was assessed by our histological criteria, which are divided into 5 grades about the liver and 4 grades about other organs according to the severity of the acute rejection. A higher grade of rejection was apparently in the small and large intestine especially after the 10th post-transplanted day (Grade II to III in the small and large intestine v. Grade 0 to II in the liver, stomach and pancreas). The study suggests the existence of organ specific susceptibility to rejection in multi-visceral organ transplantation.

Animals↗
PubMed1991

Dietary restriction permits normal parturition and lactation but suppresses mouse mammary tumor virus proviral transcription even after mammary involution.

Dietary restriction of C3H/Ou mice prevents development of spontaneous mammary adenocarcinoma by suppressing mammary expression of the mouse mammary tumor virus (MMTV) via a mechanism which may involve prolactin. In the present study, dietary restriction of 40% was imposed for 16 weeks on nulliparous C3H/Ou mice, interrupted by ad libitum consumption at mating and continued only during pregnancy and lactation, with 40% energy restriction reimposed at the end of lactation. The results show that mammary MMTV mRNA expression levels of chronic energy intake restricted (CEIR) mice and ad libitum fed mice are similar and elevated during early lactation, when all mice of both groups are being fed ad libitum energy levels. In spite of this, and in marked contrast, when CEIR dams are returned to 40% dietary restriction following the weaning of litters, mammary MMTV transcription is suppressed to levels 4-5-fold less than those measured in mammary glands from ad libitum fed controls. Within the 38 weeks of study, 73% of ad libitum fed uniparous mice at risk and 11% of CEIR uniparous mice at risk developed mammary tumors, yet mice of both dietary groups delivered and weaned healthy litters with comparable efficiency. When dietary restriction is maintained in CEIR mice during pregnancy and lactation, efficiency of conception and litter size are reduced, and MMTV transcription is suppressed even during lactation. Mean serum prolactin levels were not significantly different among dietary groups. These findings show that the level of MMTV transcription is rigorously influenced by dietary energy level, and that 40% dietary restriction of C3H/Ou mice not only suppresses mammary MMTV transcription and prevents mammary tumor development in uniparous mice, but also permits normal conception, gestation, lactation, and the production of healthy litters as long as the nutritional demands of gestation and lactation are met.

Adenocarcinoma↗
PubMed1991

A case of clinically diagnosed pure septal infarction.

Interventricular septal involvement in myocardial infarction is usually associated with infarction of the left ventricular anterior free wall, as the obstruction is at the major portion of the left anterior descending coronary artery. Acute myocardial infarction with obstruction only of the first septal branch is rare. We describe here a case of pure septal infarction. The case was diagnosed by emergency coronary arteriogram (CAG). Although the patient had a large first septal branch, his global left ventricular function was preserved. Abnormal findings were localized in only septal region as determined by left ventriculography (LVG), two-dimensional echocardiography (2DE), and 99mtechnetium pyrophosphate (99m Tc-PYP) and 201thallium (201Tl) myocardial scintigraphy.

Adult↗
PubMed1991

Thyroid microsomal antigen in Graves' thyroid is not different from that in normal thyroid.

Differences from normal in microsomal antigen (M-Ag) may be involved in the development of autoimmune thyroid disease. We compared the M-Ag in Graves' thyroid immunologically and biochemically to that in normal thyroid. The concentration of M-Ag, measured with an enzyme-linked immunosorbent assay, was significantly greater in the Graves' microsomes than in normal microsomes. Binding of a patient's microsomal antibody to Graves' microsomes was completely inhibited when the serum was first incubated with normal thyroid microsomes. Sodium dodecylsulfate-polyacrylamide gel electrophoresis and Western blotting were done with a monoclonal antibody to denatured M-Ag. In both Graves' and normal thyroids, M-Ag existed as 107-, 101-, and 95-kDa peptides. After incubation with V8 protease, the residual antigenic peptide had a molecular weight of less than 60,000 and after incubation with trypsin, 95- and 87-kDa peptides and several smaller antigenic peptides were found. There were no significant differences in the pattern of normal and Graves' microsomes after digestion. Two-dimensional gel electrophoresis of Graves' microsomes showed that the isoelectric point for the 107-kDa peptide was at pH 7.2; that for the 101-kDa peptide was at pH 6.2, and that for the 95-kDa peptide was at 6.5. These values were not different from those observed for normal microsomes. These results indicate that M-Ag in Graves' thyroid does not differ from that in normal thyroid, and that microsomal antibodies in autoimmune thyroid disease probably do no arise from differences in the antigen.

Autoantigens↗
PubMed1991

Why no simple relationship between thyroid peroxidase activity-inhibiting immunoglobulins and thyroid function in autoimmune thyroid disease?

We have reported that some anti-thyroid peroxidase antibodies inhibit the activity of thyroid peroxidase in vitro. These thyroid peroxidase activity-inhibiting immunoglobulins seem to inhibit thyroid function in some patients, but the relationship between thyroid peroxidase activity-inhibiting immunoglobulins and thyroid function is not simple. We designed this study to explore this lack of a simple relationship. We stained immunoglobulin G deposits by immunofluorescence staining or the peroxidase-antiperoxidase method, and stained endogenous thyroid peroxidase activity by enzyme histochemistry in thyroid sections. When cryostat thyroid sections were incubated with thyroid peroxidase activity-inhibiting immunoglobulins, immunoglobulin G deposits were seen as lines of stain on the apical border and as intracellular staining, and endogenous thyroid peroxidase activity was inhibited. In paraffin-embedded thyroid sections from 5 Hashimoto's patients and 6 Graves' patients, immunoglobulin G deposits were not found on the apical border of the follicular epithelium. In frozen thyroid sections from 22 Graves' patients, no clear deposits of immunoglobulin G on this apical border were seen. In organ-cultured thyroid slices incubated with thyroid peroxidase activity-inhibiting immunoglobulins, endogenous thyroid peroxidase activity was not inhibited. In conclusion, thyroid peroxidase activity-inhibiting immunoglobulins may reach its antigen only with difficulty. This is one of the reasons why no simple relationship is observed between thyroid peroxidase activity-inhibiting immunoglobulins and thyroid function.

Antigens↗
PubMed1990

[The clinical course of Hashimoto's thyroiditis during a 5 year observation period in relation to the change in thyroid function and the titers of the antithyroid antibody].

In order to discover whether or not thyroid function in patients with Hashimoto's disease will move toward hypothyroidism with age, we investigated the thyroid function and antithyroid antibody titers at the initial examination and 5 years later in 181 patients with goitrous Hashimoto's thyroiditis. Pregnant patients and those within 1 year of the postpartum period were excluded. The thyroid function was assessed before medication or at least one month after stopping it. At the initial examination, 52% (94 cases) of the cases were euthyroid, 24% (44 cases) were subclinically hypothyroid and 24% (43 cases) were hypothyroid. It was not observed whether the incidence of hypothyroidism tended to be greater in older patients or in patients with longer duration of illness. Five years later, 68% of euthyroid patients at the initial examination remained in euthyroid state, 18% had become subclinically hypothyroid, and 9% were hypothyroid. The thyroid function was not evaluated in 5% of the patients because they were under treatment with 1-thyroxine. In the patients with subclinical hypothyroidism at the initial examination, 30% had become euthyroid, 23% remained subclinically hypothyroid, 32% had become hypothyroid and 16% were not evaluated. Thirty percent of the patients with hypothyroidism at the initial examination had become euthyroid, 7% were subclinically hypothyroid, 28% remained hypothyroid and 35% were not evaluated. The higher the titer of TGHA, the higher the percentage of hypothyroidism at the first examination. A similar but much stronger tendency was observed in the patients with a higher titer of MCHA. In the patients with a higher titer of TGHA, the number of hypothyroid patients approximately doubled after 5 years, although such a tendency was not observed in the patients with a higher titer of MCHA. In patients with persistent hypothyroidism, the age was significantly higher, the serum concentration of T3 lower and the titer of TGHA at the initial examination and MCHA 5 years later higher than in the patients with transient hypothyroidism. The titer of MCHA was significantly decreased 5 years later in patients with transient hypothyroidism. From these results, it is indicated that in patients with goitrous hypothyroidism, the incidence of hypothyroidism was higher in the cases with high titers of antithyroid antibody than in those with low titers, and that in the patients with transient hypothyroidism, the age was lower, the serum level of T3 higher and the titer of TGHA lower than in the cases with permanent hypothyroidism.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1990

Identification and determination of sulphamethazine and N4-acetylsulphamethazine in meat by high-performance liquid chromatography with photodiode-array detection.

A simple and selective method for the determination of sulphamethazine (SMT) and its metabolite, N4-acetylsulphamethazine (N4-AcSMT), in meat by high-performance liquid chromatography (HPLC) with photodiode-array detection was developed. The drugs were extracted from meat with 0.2% metaphosphoric acid-methanol (6:4), followed by a Bond-Elut C18 clean-up procedure. The HPLC separation was carried out on a Supersphere RP-18e column (125 X 4.0 mm I.D.) using 0.05 M sodium dihydrogenphosphate (pH 4.5)-acetonitrile (8:2) as the mobile phase at a flow-rate of 0.5 ml/min, and monitored with a photodiode-array detector. The recoveries of SMT and N4-AcSMT from meat fortified at 0.5 micrograms/g were 90.1-93.3 and 93.0-94.4%, respectively, with coefficients of variation of 1.9-3.2 and 1.5-2.7%. The limits of detection were 0.02 micrograms/g for each drug. SMT was found in ten samples of imported meat (12.5%) at levels ranging from 0.05 to 1.05 micrograms/g.

Animals↗
PubMed1990

A trial of molecular epidemiology using bovine enteroviruses isolated monthly from cattle.

Enteroviruses were isolated monthly for one year from feces in the intestine of 47 cattle. Judging from the isolation panel, it was suggested that endemic infection occurs. Genetic changes of isolated enteroviruses were traced using RNase T1 oligonucleotide fingerprint analysis and nonparametric distance scaling. Using some characteristics transitions of fingerprint patterns we could also trace some strains. These analyses suggested that in some strains drastic genetic changes may occur, which coincide with additional infections transmitted from other cows. Furthermore, it was indicated that the genetic changes of viruses isolated from cow R13 were not very drastic, but genetic changes were drastic for viruses isolated from cow R19. Overall, we could never observe the same fingerprint pattern using RNase T1. This study suggests that genetic changes tend to accumulate as time elapses, and at the same time, infection decreases.

Animals↗
PubMed1990

Prolactin effects on the dietary regulation of mouse mammary tumor virus proviral DNA expression.

Chronic energy-intake restriction inhibits mouse mammary tumor virus (MMTV)-induced mammary tumors in C3H/Ou mice by greater than 90%. We have shown that associated with suppression of mammary tumorigenesis there is a reduction or inhibition of circulating prolactin, MMTV particles expressed, and MMTV mRNA transcription in mammary glands (and in most organs tested). To understand the concerted action of prolactin, energy-consumption level, and MMTV on inducing mammary tumors, experiments were designed to control prolactin and energy levels in order to evaluate their effects on MMTV mRNA expression. Mice on restricted diets were grafted with adenohypophyses, and mice fed ad libitum were treated with the dopaminomimetic agent octahydrobenzo [g]quinoline. Adenohypophyseal grafting significantly increased prolactin in dietary (energy)-restricted mice, and this effect was associated with an increase in MMTV mRNA expression within the mammary gland; a linear correlation between prolactin levels and MMTV mRNA expression in the mammary gland was found. Conversely, elimination of the nocturnal peak of circulating prolactin by i.p. injection of dopaminomimetic octahydrobenzo [g]quinoline to mice fed ad libitum delayed (by 8 weeks) and reduced (even as long as 25 weeks) mammary gland MMTV mRNA expression. These findings associate prolactin influences with MMTV mRNA production in mice and help explain the link between chronic energy-intake restriction and reduced MMTV gene expression.

Aminoquinolines↗
PubMed1990

Suppression of mouse mammary tumor proviral DNA and protooncogene expression: association with nutritional regulation of mammary tumor development.

Chronic energy intake restriction (CEIR) reduces mouse mammary tumor virus (MMTV)-induced mammary tumors in C3H/Ou mice. Fewer than 10% of C3H/Ou mice developed mammary tumors during 88 wk of study when subjected to CEIR regardless of calorie source (fat vs. carbohydrate). By contrast, 100% of mice fed ad libitum diets relatively high in fat or carbohydrate or a commercial diet developed tumors by 35-40 wk. MMTV proviral DNA transcription was shown to be activated in spleen, liver, lung, kidney, small intestine, and mammary gland of mice consuming these diets ad libitum. By contrast, these messages were suppressed by CEIR in all tissues analyzed except spleen. MMTV proviral messages in liver and mammary gland increased with age in full-fed mice and were suppressed by CEIR. These findings suggest that the nutritional regulation of MMTV proviral DNA expression is tissue-specific. In CEIR mice the suppressed MMTV proviral DNA transcripts in mammary gland and liver increased with time in association with the delayed onset of mammary tumors. Mammary tumorigenesis in C3H mice is associated with integration of MMTV proviral DNA, which appears to activate a putative mammary tumor protooncogene, int-1. CEIR apparently decreases the frequency of viral reintegration adjacent to the int-1 gene and thus inhibits expression of int-1 and probably an initiation step in mammary tumorigenesis. Expression of other putative protooncogenes, int-2 and ras, in liver tissue was also reduced by CEIR. These findings indicate that both initiation and promotion of mammary tumorigenesis are influenced by CEIR in C3H/Ou mice.

Animals↗
PubMed1990

Inhibition by immunoglobulin G of synthesis of thyroid hormone in thyroid cultures from hypothyroid patients with goitrous Hashimoto's thyroiditis.

Recently, thyroid microsomal antigen was identified as thyroid peroxidase, and thyroid microsomal antibody was found to inhibit thyroid peroxidase activity in vitro. We investigated the possibility that anti-microsomal antibody inhibits the iodination of tyrosine, in vivo. Immunoglobulin G with or without anti-microsomal antibody from hypothyroid patients with goitrous Hashimoto's thyroiditis inhibited thyroid hormone synthesis in cultured slices of normal human thyroid tissue. IgGs with anti-microsomal antibody inhibited 125I thyroidal uptake and thyroid hormone synthesis stimulated by TSH more than normal IgG did. However, the same results were obtained with IgGs without anti-microsomal antibody. This effect did not involve anti-microsomal antibody, anti-thyroglobulin antibody, TSH-binding inhibitor immunoglobulin, thyroid stimulation-blocking immunoglobulin, or the cAMP level of the thyroid tissue. The ratio of organic I to inorganic I with stimulation by TSH in slices incubated with IgG from hypothyroid patients with goitrous Hashimoto's thyroiditis or normal IgG was not significantly different, but was significantly higher in slices incubated with methylmercaptoimidazole. Therefore, IgG from hypothyroid patients with goitrous Hashimoto's thyroiditis mainly suppressed 125I thyroidal uptake, rather than inhibiting thyroid peroxidase activity. In addition, this IgG was present in the serum of 11 of the 12 hypothyroid patients with Hashimoto's thyroiditis studied. This IgG may be involved in the mechanism that causes hypothyroidism in some patients with goitrous Hashimoto's disease.

Adult↗