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Biomedical subjects

M Saitoh

Publications and source records attributed to M Saitoh.

At least 19 recordsLinked to original sources

Molecular structure of the C beta catalytic subunit of rat cAMP-dependent protein kinase and differential expression of C alpha and C beta isoforms in rat tissues and cultured cells.

A full-length cDNA clone encoding the C beta catalytic subunit of cAMP-dependent protein kinase (PKA) was isolated from a rat brain cDNA library. A 1.1 kb cDNA containing the entire coding region encodes for a protein of 351 amino acids that shows more than 95% sequence homology to the C beta subunits in mouse, bovine and human. Northern blot analysis showed distinct patterns of C alpha and C beta mRNA expression in the brain and various peripheral tissues. The C alpha mRNA was widespread and highly expressed in brain, heart, adrenal gland, testis, lung, kidney, spleen and liver, whereas the C beta mRNA was unevenly expressed in the brain and adrenal gland and in much lesser amounts in other tissues. The C alpha mRNA was evenly distributed and highly expressed through various regions of the brain, while the C beta mRNA was expressed in lesser amounts and was unevenly distributed. In neuronal and glial cultured cells, C alpha mRNA was also predominantly expressed but C beta mRNA was undetectable. The differential distribution between the C subunit isoforms of PKA suggests that individual subunits are involved in specialized functions.

Amino Acid Sequence

Parathyroid hormone stimulates ATP-dependent calcium pump activity by a different mode in proximal and distal tubules of the rat.

A new technique was developed to isolate basolateral membrane vesicles individually from proximal and distal tubules of the rat cortex. This new technique enabled us to study differences in their kinetics and mechanisms of hormonal regulation of Ca pump between proximal and distal tubules. The Ca pump in distal tubule has very high affinity (42.6 nM Ca2+) and the one in proximal tubule has relatively low affinity (75.6 nM Ca2+). Parathyroidectomy (PTX) decreased the Vmax of Ca pump activity in proximal tubule (4.68 +/- 0.99 vs. 9.08 +/- 2.21 nmol 45Ca2+/min per mg protein BLMV, P less than 0.05), while it increased Km in distal tubule (93.1 +/- 11.0 vs. 35.1 +/- 16.1 nM Ca2+, P less than 0.05). Restoration of serum Ca2+ concentration by 1,25(OH)2D3 supplement could not reverse these changes by PTX in Ca pump activity in either the proximal or the distal tubule. In conclusion, this study strongly suggested that parathyroid hormone stimulated Ca pump activity by increasing the Vmax in proximal tubule and by increasing the affinity in distal tubule. 1,25(OH)2D3 does not have a direct effect on the basolateral membrane Ca pump activity.

Adenosine Triphosphate

Comparative teratogenicity of di-n-butyltin diacetate with n-butyltin trichloride in rats.

Teratological tests were conducted on di-n-butyltin diacetate (DBTA), and n-butyltin trichloride (MBTC). Pregnant Wistar rats were treated orally with DBTA at doses of 0, 1.7, 5.0, 10.0, and 15.0 mg/kg/day or with MBTC at doses of 0, 50, 100, 200, and 400 mg/kg/day during days 7-17 of gestation. Cesarean sections were performed on day 20 of gestation. Thymic atrophy of the pregnant rats was observed in a dose-dependent manner by DBTA treatment. The incidence of dead or resorbed fetuses and total resorption fetuses increased at the highest dose of DBTA. The incidence of fetuses with external malformations, such as cleft mandible, cleft lower lip, ankyloglossia (tongue-tie) and schistoglossia (cleft tongue), increased in a dose-dependent manner by DBTA treatment. The incidence of fetuses with skeletal malformations such as anomaly of mandibular fixation, fused ribs, fused cervical vertebral arches and fused thoracic vertebral arches also increased at 10.0 and 15.0 mg/kg. However, MBTC, one of the main metabolites of di-n-butyltin, failed to show any evidence of tetatogenic activity at any doses tested. The results indicate that DBTA has potent teratogenic effects on rat fetuses, and DBTA is different from MBTC with respect to teratogenic effects.

Animals

Expression of feline immunodeficiency virus gag gene in Escherichia coli.

The gag gene of a Japanese feline immunodeficiency virus (FIV) isolate, designated as FIV TM 2, was expressed in Escherichia coli as a fusion protein with TrpE. Using this expressed protein, an enzyme-linked immunosorbent assay was developed for detection of antibodies to FIV gag protein in feline sera. With serum samples from a cat experimentally infected with FIV, it was demonstrated that the period of seroconversion detected by this method corresponded to that by Western blotting.

Cloning, Molecular

Immunofluorescent antibody response to lactic dehydrogenase virus in different strains of mice.

The development of antibody against lactic dehydrogenase virus in five strains of mice (NZB x NZWF1, BALB/c, C.B-17, ICR and C.B-17 scid or SCID mice) was examined by indirect immunofluorescence (IIF) of infected liver sections. IIF antibody appeared 1 to 3 weeks and rose progressively 2 to 4 weeks after infection in four strains of mice (NZB x NZWF1, BALB/c, C.B-17 and ICR mice). SCID mice did not develop antibody. These results suggest that IIF may be applicable for detecting LDV infection in many other ordinary strains of mice.

Animals

A hematological remission by clonal hematopoiesis after treatment with recombinant human granulocyte-macrophage colony-stimulating factor and erythropoietin in a patient with therapy-related myelodysplastic syndrome.

We treated a patient with therapy-related myelodysplastic syndrome (MDS) with human recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) and erythropoietin (Epo). The patient achieved a hematological remission which continued for more than 16 months despite discontinuation of the treatment. Before the treatment with GM-CSF and Epo the patient had severe pancytopenia, required frequent red cell transfusions, and experienced episodes of severe infection, but after the therapy he no longer needed transfusion and no longer had the infection. While the patient remained in hematological remission, bone marrow examination revealed trilineage dysplasia, and cytogenetic analysis showed an abnormal karyotype [48, XY, +8, +der(1q5p)] in 100% of the metaphases examined. These findings suggest that the hematological remission of this patient may not result from the recovery of the non-clonal hematopoiesis of a normal clone, but result from the monoclonal hematopoiesis of a neoplastic clone.

Blood Cell Count

Selective renal tumour biopsy under ultrasonic guidance.

Selective renal biopsy under ultrasonic guidance has been used widely because it provides safe and accurate tissue sampling. Using this technique, we biopsied 36 renal tumours and obtained specimens in 35 cases. Histology of the biopsy coincided with that of the surgical specimen in 18/21 cases. Dissemination of tumour cells, thought to have been caused by needle biopsy and/or surgical manipulation, was observed in only 1 case of sarcoma. The method thus proved effective in determining treatment and it is suggested that it should be used in accordance with the criteria which we have devised.

Adult

Cardiovascular and sympathetic nervous responses to mental stress in hyperthyroid patients.

We measured the cardiovascular and sympathetic nervous responses to mental stress in subjects with hyperthyroidism. Ten hyperthyroid subjects and 10 age- and sex-matched normal subjects performed mental arithmetic. At rest, the heart rate was higher in hyperthyroid subjects than in normal subjects, but systolic blood pressure, plasma norepinephrine, and epinephrine concentrations did not differ between the two groups. Systolic blood pressure and heart rate during stress, and the changes in blood pressure and in plasma epinephrine concentration from rest to stress, were higher in hyperthyroid subjects than in normal subjects. Therefore, cardiovascular and adrenal responses to mental stress were abnormally high in subjects with hyperthyroidism.

Adolescent

Cardiovascular and sympathetic nervous response to dynamic exercise in patients with essential hypertension.

To investigate the relationship among systolic blood pressure (SBP) during exercise (EX), left ventricular hypertrophy (LVH) and plasma norepinephrine concentration (NE) in patients with essential hypertension (HT), 20 patients with HT and 20 age- and sex-matched normal subjects were studied using treadmill testing. According to the change in SBP from rest to EX (delta SBP), patients with HT were classified into two groups (group I, n = 12, delta SBP less than 72 mmHg: group II, n = 8, delta SBP greater than or equal to 72 mmHg). There were no significant differences between the two groups with regard to SBP at rest, NE at rest and NE on EX. However, SBP at peak EX, delta SBP and the incidence of LVH were greater in group II than in group I. We conclude that exaggerated SBP response to EX in patients with HT is related to LVH.

Adult

Thermal coefficients of paste-paste type pulp capping cements.

Thermal coefficients of four kinds of commercially available paste-paste type pulp capping cements were examined. Control reference samples were made of dentin. A thermal coefficient analyzer was used, heating specimens for a few nanoseconds by a xenon flash bulb and measuring thermal changes by using a thermocouple. Thermal coefficients were examined by this non-steady state method. Thermal conductivities of all cements were almost the same or lower than that of dentin. Therefore, when each cement was heated, the penetrating energy was almost the same or lower than that of dentin. The thickness of the cements was converted into that of the dentin by using the obtained thermal conductivity. The 1-mm thickness of the examined cements were equal to between 0.97-mm and 2.10-mm thicknesses of lost dentin. The use of a pulp capping cement provided better pulp protection from thermal stimuli than did the same thickness of dentin.

Calcium Hydroxide

[Argyrophilic nucleolar organizer region proteins (Ag-NORs) in human central nervous tumors].

A silver colloid staining technique for identifying nucleolar organizer region-associated proteins (Ag-NORs) was applied to 17 primary gliomas and 16 meningiomas. These comprised 8 glioblastomas, one pleomorphic xanthoastrocytoma, 8 benign astrocytoma, 10 nonrecurrent meningiomas and 6 recurrent meningiomas, in which the mean number of Ag-NORs' per nuclei, were 3.37, 2.34, 2.57, 2.16 and 2.80 respectively, identifying significant differences among these groups. Ag-NORs of four giant cell glioblastomas showed low numbers of Ag-NORs, suggesting better prognosis. In spite of the time consuming and complicated counting method Ag-NORs is reproductive and useful as a tool for estimating the proliferating potential of various brain tumors, and appears to widely applicable in clinical laboratories.

Adolescent

Nasal T-cell lymphoma associated with hemophagocytic syndrome. Immunohistochemical and genotypic studies.

A 53-year-old man with nasal T-cell lymphoma exhibited hemophagocytic syndrome as a terminal event. Immunohistochemical studies revealed that neoplastic cells were derived from T cells. Genotypic analysis of DNA samples that were obtained from the frozen tissue specimens demonstrated clonal rearrangements of the T-cell receptor beta-chain genes. No rearrangement was observed in the immunoglobulin heavy-chain gene. To our knowledge, only three cases of nasal T-cell lymphoma with hemophagocytic syndrome have been reported before the present case. All of these cases occurred in Oriental patients. The present report suggests the beneficial effect of high-dose glucocorticoid therapy on the prolongation of survival compared with that of the other three cases.

Gene Rearrangement, beta-Chain T-Cell Antigen Rece

[Preparation of the first draft of environmental health criteria for acetonitrile: production process of the draft].

Acetonitrile is a high-polarity aprotic organic solvent used in DNA synthesizers, HPLC, and electrochemistry. In addition, it is used larger amounts at petrochemical companies and pharmaceutical firms. Preparation of an Environmental Health Criteria (EHC) monograph for acetonitrile was started in 1986, and its first draft except the environmental section was completed on June 21, 1991. The environmental section has been prepared by Dr. S. Dobson (ITE/UK). The first draft was circulated to EHC Contact Points for comment in March 1992.

Acetonitriles

[Studies of diet management and insulin resistance in obese pregnant women].

In an attempt to determine the principles of diet management in obese pregnant women, the association between maternal weight gain during pregnancy (Group I; weight reduction, Group II; +0-4 kg, Group III; +5-9 kg, Group IV; +10 kg-) and the incidence of the complications was investigated in 151 obese pregnant women. Studies on glucose tolerance and insulin binding to erythrocytes were also undertaken. 1) In Group I, the incidences of C/S, forceps delivery, prolonged labor and complication of PIH were lower than those of other groups. There were no heavy-for-dates and light-for-dates babies in Group I, differing from the other three groups. 2) Plasma levels of glucose and insulin were high in obese pregnant women on 75 g OGTT in the second trimester. The binding sites of insulin to erythrocytes were significantly decreased in obese pregnant women. In conclusion, the risks of pregnancy complicated by obesity were high. Insulin resistance was a characteristic of obese pregnant women. The results of this study suggested that the nutritional requirements for very obese pregnant women should be restricted to maintaining the same weight or losing weight during the course of pregnancy to minimize maternal and perinatal risks.

Blood Glucose

[A retrospective comparison study of patients old and young with non-Hodgkin's lymphoma].

One hundred patients with diffuse non-Hodgkin's lymphoma were treated with combination chemotherapy including adriamycin. Seventy-one patients were under age 70 and 29 were 70 years or older. The clinical characteristics of the two groups were similar, except that the patients showed elevated serum BUN were in the elderly group. The complete remission rate in the elderly patients (66%) was slightly lower than that in the younger patients (75%) (p = NS). The average length of survival in the elderly patients was significantly shorter than in the younger patients (p less than 0.05) (projected 5-year survival: 28 +/- 11% vs 52 +/- 7%). The duration of remission for all patients in the elderly patients did not differ from that in the younger patients (projected 2-year survival: 40 +/- 10% vs 45 +/- 6%). Death during the induction chemotherapy from causes other than lymphoma occurred in 14% of patients over 70-year-old and in one percent of younger patients. At relapse, the response rate was significantly lower in the elderly patients than in the younger patients (CR+PR: 28% vs 78%, p = 0.03). To prevent toxic death in remission induction therapy, drug dose elderly patients should be attenuated according to their general conditions and performance status.

Age Factors

[A case of dural sarcoidosis].

A 26 year-old man, who was treated for meningitis in our hospital previously, was rehospitalized 1 year later because he developed disturbance of consciousness, gait disturbance and urinary incontinence. Blood examination revealed accelerated ESR, elevated GPT, slight elevation of serum Ca, strong positive CRP, and a decrease in PHA and Con A. ACE was within normal range and tuberculin reaction was negative. Lumbar puncture revealed that the initial pressure was 310 mmH2O, cells were 152/3, and protein was 343 mg/dl. Bilateral hilar lymphadenopathy was absent in chest X ray film. Head CT revealed enlarged lateral ventricles and irregularly enhancing nodular lesions in the anterior half of the falx cerebri, and abnormally strong enhancement of the choroid plexus. Ventriculoperitoneal shunt was performed. As a diagnosis was difficult to obtain from the clinical data, biopsy of the nodular lesions was performed. The histopathologic diagnosis was sarcoidosis. Steroid hormone was administered thereafter, and the nodular lesions of the falx disappeared in the follow-up. In the literature, only 8 cases of sarcoidosis of the dura mater have been reported. Since intracranial sarcoidosis is a part of systemic sarcoidosis, its diagnosis is not difficult in most cases. However, in cases difficult to diagnose as in our case, biopsy may be necessary. When nodular lesion occurs in the dura mater, sarcoidosis must be included as a possibility in the differential diagnosis in addition to the usual meningioma, lymphoma, and metastatic brain tumor.

Adult

[An experience of laser therapy of lung cancer complicated with hemophilia A].

We applied an endoscopic Nd-YAG laser therapy for an early hilar lung cancer complicated with hemophilia A in a patient of 62-year-old male. Abnormality was pointed out by means of sputum cytology. But, no shadow of tumor was observed by chest x-ray films and computed tomogram. By a bronchoscopy, a mild irregular mucomembrane and stenosis without tumor were exhibited. By means of cytological diagnosis of an abrasive-washing specimen of that region, the presence of squamous cell carcinoma was proved. Also, he was diagnosed as factor VIII deficient hemophilia A. So we performed him a laser therapy in place of the operation and with an intrabronchial arterial infusion. After the laser treatment, the conditions progressed better without any recurrence but about one and a half years later, an intrapulmonary metastasis occurred. Then, radiation and chemotherapy have been applied and at present, the patient is in a good state although under the tumor-bearing condition.

Carcinoma, Squamous Cell