Biomedical subjects

H Sakamoto

Publications and source records attributed to H Sakamoto.

At least 505 records · Page 28Linked to original sources

PubMed1994

Rapid techniques for DNA extraction from routinely processed archival tissue for use in PCR.

AIMS: To evaluate the ability of four rapid DNA extraction methods to provide DNA for the polymerase chain reaction (PCR) from routinely fixed, paraffin wax embedded archival tissues. METHODS: Eighteen blocks of various tissues, 18 blocks of cervical cancer specimens, and nine blocks of B cell lymphomas were investigated. Both normal and biopsy specimen sized tissues were studied. DNA was extracted using four methods: boiling for 20 minutes in distilled water; boiling for 20 minutes in 5% Chelex-100 resin solution; 3-hour proteinase K digestion; and 3-hour proteinase K digestion, followed by boiling in 5% Chelex-100. Different exons of the p53 gene, human papillomavirus type 16 (HPV 16) sequence, and immunoglobulin heavy chain (IgH) gene rearrangement were amplified from the extracts. RESULTS: The Chelex boiling, proteinase K digestion, and proteinase K digestion-Chelex boiling methods produced DNA suitable for amplification in all of the 45 samples. Boiling in water yielded insufficient template for the PCR in three of the 45 cases (7%), and in six of 42 positive cases (14%) much fainter bands were observed, mostly when the processed material was either biopsy specimen sized or a B cell lymphoma sample. Fragments of the p53 gene were successfully amplified up to 408 base pairs in water boiled extracts, up to 647 in Chelex boiled preparates, and up to 984 in proteinase K digested and proteinase K digested-Chelex boiled samples, although with decreased sensitivity in the last case. All of the templates were reusable after 3 months of storage at -20 degrees C. CONCLUSIONS: Chelex boiling, proteinase K digestion, and proteinase K digestion followed by Chelex boiling produce suitable templates for the PCR from a large variety of paraffin wax embedded tissues. As the simple 20 minute boiling method in 5% Chelex-100 solution requires minimal manipulation and time, it could be useful, especially in the routine processing of large amounts of material.

Base Sequence↗

PubMed1994

Origin, course and distribution of the superior gluteal nerve.

Ten pelvic halves of six Japanese male cadavers were dissected in order to obtain precise anatomical knowledge of the course and distribution of the superior gluteal nerve. The more anterior parts of the glutei medius and minimus, innervated by branches of the superior gluteal nerve, were revealed to originate more cranially, and the tensor fasciae latae was innervated by the cranialmost element of the nerve. Based on these findings, it might be proposed that the course and distribution of the superior gluteal nerve are directly influenced by the anterior rotation of the gluteus medius.

Buttocks↗

PubMed1994

Presence of bronchoalveolar lavage fluid necessary for platelet activating factor-induced ciliary depression.

Many different mediators have been implicated in allergic responses and allergic diseases of the respiratory tract. The influence of several allergic inflammatory mediators on the ciliary activity has been well studied. However, ciliary responsiveness to platelet-activating factor (PAF) is yet to be established conclusively. Our study concerns the response of normal tracheal cilia from the guinea pig during an in vitro contact with PAF. PAF at concentrations between 10(-10) and 10(-8) M never affected the ciliary activity. On the other hand, such concentrations of PAF inhibited the ciliary activity in a dose-response fashion within 5 min in the presence of alveolar macrophages. Such a ciliary dysfunction should allow allergens and other molecules to easily invade epithelium and submucosa of the airway, resulting in an increased epithelial permeability which might be a mild manifestation of airway hyperresponsiveness and make a significant contribution to further airway hyperresponsiveness.

Animals↗

PubMed1994

Exaggerated vascular response due to endothelial dysfunction and role of the renin-angiotensin system at early stage of renal hypertension in rats.

We investigated whether endothelial dysfunction might contribute to the exaggerated vasoconstriction that was induced by the administration of norepinephrine at the early stage of one-kidney, one-clip renal hypertension (1K1C) in rats. We also studied the role of the renin-angiotension system in this phenomenon. Male Wistar rats were killed 48 hours after the induction of renal artery stenosis or sham operation, and ring preparations of the thoracic aorta were obtained. The isometric contraction and relaxation of aortic strips produced by norepinephrine and acetylcholine, respectively, were recorded with a force-displacement transducer. The aorta of 1K1C rats showed a significantly (P < .05) exaggerated contractile response to norepinephrine as compared with that of control rats. Rubbing the endothelium and treatment with methylene blue or NG-monomethyl L-arginine acetate augmented the contractile responses to norepinephrine to a greater extent in control rats than in 1K1C rats; therefore, the responses of the groups did not differ significantly. In the second experiment, rats received 0.05% captopril, 0.02% enalapril, or 0.02% nicardipine in the drinking water for 1 day before and for 48 hours after the induction of renal artery stenosis or sham operation. The increased contractile responses of the aorta to norepinephrine in 1K1C rats were normalized to the level of the control rats by treatment with either captopril or enalapril but not with nicardipine. These results suggest that the endothelial dysfunction may contribute to the exaggerated norepinephrine-induced vasoconstriction observed in the 1K1C rats and that angiotensin I-converting enzyme inhibitors can restore the endothelial function.

Acetylcholine↗

PubMed1994

Endothelin (ET)-3 stimulates cyclic guanosine 3',5'-monophosphate production via ETB receptor by producing nitric oxide in isolated rat glomerulus, and in cultured rat mesangial cells.

We investigated the effects of endothelins on receptor-mediated cyclic nucleotide metabolism in rat glomerulus, inner medullary collecting duct (IMCD), and also in cultured rat glomerular mesangial cells. Endothelin (ET)-3 dose-dependently stimulated cGMP accumulation in glomerulus, which was higher than that of ET-1 or ET-2. ETB receptor agonist IRL 1620 produced cGMP in a dose-dependent manner, mimicking the effect of ET-3. ETA receptor antagonist BQ123-Na did not inhibit ET-3- or IRL 1620-stimulated cGMP generation. NG-monomethyl-L-arginine (L-NMMA) significantly inhibited ET-3- or IRL 1620-induced cGMP production, suggesting that ET-3- or IRL 1620-stimulated cGMP generation was mediated through nitric oxide (NO). Intracellular Ca chelator BAPTA/AM and calmodulin antagonist W-7, but not Ca channel blocker nicardipine, significantly inhibited ET-3- or IRL 1620-induced cGMP generation. In cultured rat mesangial cells, ET-3 stimulated cGMP generation through NO in the presence of fetal calf serum, which was not inhibited by addition of BQ123-Na. In IMCD, ET-3 had no stimulative effect on cGMP generation. We conclude that ET-3 stimulates NO-induced cGMP generation through ETB receptor in glomerulus. This effect seems to be mediated through intracellular Ca/calmodulin, but not through Ca influx via L-type Ca channel. Mesangial cells can be a source of NO coupled to ETB receptor activation in glomerulus. From these results, mesangial ETB receptor may work to counteract the vasoconstrictive effect of endothelin caused via ETA receptor in glomerulus.

1-Methyl-3-isobutylxanthine↗

PubMed1994

A clinical and pathologic study of a large Japanese family with Machado-Joseph disease tightly linked to the DNA markers on chromosome 14q.

The gene locus for Machado-Joseph disease (MJD) has been mapped to chromosome 14q by linkage analysis, mainly using a single large Japanese family. We studied the clinical and neuropathologic findings of this family with MJD, comparing them with those of spinocerebellar ataxia 1 (SCA1) and spinocerebellar ataxia 2 (SCA2) families. The pedigree included 30 affected persons in 125 members of five generations. Neurologic examination of 21 patients revealed that dystonia, difficulty in eyelid opening, slowness of movements, bulging eyes, and facial-lingual fasciculation-like movements or myokymia are characteristic of this MJD family, although these three autosomal dominant spinocerebellar degenerations have several neurologic signs and symptoms in common. In contrast with SCA1 and SCA2, degeneration of the subthalamopallidal system and relative sparing of the olivocerebellar system were the main neuropathologic features of MJD.

Adult↗

PubMed1994

A new device for indirect blood pressure measurement in rabbits.

We evaluated the reliability of a new device for indirect measurement of systolic blood pressure in normal and hypertensive New Zealand White rabbits. This device consisted of an ear unit composed of an air chamber and sensitive photoelectric sensors, and was connected to an apparatus used for the tail-cuff method. Systolic blood pressure was determined by simultaneous recordings of pulse volume oscillations of the central ear artery and the chamber pressure. The blood pressure in 8 normal rabbits was 116 +/- 7/78 +/- 6 mmHg (mean +/- SEM) by direct measurement and 100 +/- 6 mmHg by indirect measurement. In a one-kidney, one-clip hypertensive model, the new device showed that blood pressure increased from 100 +/- 7 to 158 +/- 7 mmHg over 4 weeks. After nicardipine was injected, blood pressure fell from 191 +/- 10/114 +/- 10 to 117 +/- 7/72 +/- 8 mmHg as measured by the direct method, and from 158 +/- 7 to 92 +/- 6 mmHg as measured by the new device. A strong correlation (r = 0.91, p < 0.01) was observed between direct and indirect measurements. Our findings indicate that this device provides rapid, easy and reliable measurement of blood pressure in rabbits.

Animals↗

PubMed1994

Principal component analysis, using the measurements during running and swimming test, in thoroughbred horses.

To investigate whether the running exercise fitness of individual horses could be assessed by a standardized swimming exercise test, the results of multivariate analysis of the exercise parameters measured during incremental running and swimming tests were compared. Ten thoroughbred horses were subjected to different types of exercise tests on a track or in a pool, and the maximum heart rate during and the blood lactate concentration immediately after the exercise were examined. Serial exercise parameters (VLA2, VLA4, LA0, V150, V200, HRS, HRLA2, HRLA4) referred to as the indices related to the adaptation of cardiovascular or metabolic systems were computed using the relationships between these measurements and velocity during each test, and were analyzed by a multivariate procedure, i.e. the principal component analysis. The correlation diagram between the exercise parameters on the first two component axes in running were similar to that in swimming. When the exercise fitness in each horse was compared between running and swimming, three horses trained by short-term endurance exercise were statistically distinguished in both tests and differed as a group from the other horses. Therefore, it is thought that evaluation of the exercise fitness in swimming using the multivariate analysis is useful for predicting poor performing horses on a track.

Animals↗

PubMed1994

The validity of swimming training for two-year-old thoroughbreds.

To investigate the validity of swimming training, the following matters were considered: 1) changes in the performance capacity, 2) changes in the constitution and 3) frequency of locomotor diseases. These were evaluated during a training program including both conventional exercise on a track and swimming. In this study, 24 two-year-old thoroughbred horses were studied, and divided into the following three groups: Group A, trained by only running; Group B, trained by running plus a gradual increase in swimming; Group C, trained by running plus constant swimming. As a result of standardized exercise tests, only the intercepts of the 3 regression curves between the speed and the blood lactate concentration in Group B increased significantly as the training progressed. While the growth in height in Groups B and C were greater than in Group A, the increase in girth and weight in Groups B and C were smaller than in Group A. The percentages with locomotor diseases during this experiment in Groups A, B, and C were 62.5%, 12.5% and 25.0%, respectively, and there was a significant difference (p < 0.05) between Group A and Group B. As mentioned, it was suggested that a training program including swimming training is seen as being useful for improvement in performance capacity, since it can reduce locomotor diseases in young horses and allow for smooth progress in future training.

Animals↗

PubMed1994

Changes of serum amylase, its isozyme fractions and amylase-creatinine clearance ratio in dogs with experimentally induced acute pancreatitis.

To investigate the diagnostic application of amylase to canine pancreatic diseases, serum amylase activities, its isozyme fractions and amylase-creatinine clearance ratio (ACCR) were analyzed in normal intact dogs and dogs experimentally induced acute pancreatitis. There was no statistic difference between normal male and female dogs. Amylase specific activities in pancreatic tissue extracts were more than 2,300 times higher than that in serum, and were also higher than those in other tissues; parotid and mandibular salivary glands, lung, heart, liver, spleen, duodenum, jejunum, ileum and kidney. Following the chloroform injection into the pancreatic tissue, WBC increased from 6 to 240 hr and serum glucose significantly increased at 72 and 96 hr, and no urine glucose was detected. BUN as well as serum and urine creatinine showed normal levels. ACCR increased until 96 hr without statistic significance. Serum amylase activities increased significantly after 3 hr and its isozyme was separated into 4 fractions (Amy1-Amy4) in contrast to 3 fractions (Amy2-Amy4) in intact dogs. Since this extra Amy1 seen from 1 hr increasing after 6 hr similarly to other 3 fractions, the evaluation of serum amylase and its isozyme fractions was indicated to be useful for the diagnosis of acute pancreatitis in dogs.

Acute Disease↗

PubMed1994

An interleukin-6 secreting myxoma in a hypertrophic left ventricle.

We describe a patient who had both a left ventricular myxoma and left ventricular hypertrophy; the myxoma was subsequently excised and revealed to produce interleukin-6. The combination of left ventricular myxoma and ventricular hypertrophy is uncommon. Interleukin-6 secreted from the myxoma may be an important factor in the pathogenesis of ventricular hypertrophy in this patient.

Aged↗

PubMed1994

Aldosterone response to adrenocorticotrophin and furosemide in primary aldosteronism after prolonged spironolactone treatment.

We evaluated the effects of prolonged spironolactone treatment on aldosterone secretion in patients with primary aldosteronism. The patients were hospitalized and underwent a furosemide test with or without dexamethasone, as well as an adrenocorticotrophin (ACTH) test. In untreated patients, neither plasma renin activity (PRA) nor plasma aldosterone showed a response in the furosemide test. In patients receiving spironolactone, furosemide increased significantly both the PRA and the plasma aldosterone concentration (from 2.6 +/- 0.8 to 7.0 +/- 2.0 micrograms.l-1.h-1 (p < 0.05) and from 345.6 +/- 55.8 to 492.7 +/- 76.8 ng/l (p < 0.05), mean +/- SEM, respectively). Dexamethasone administration had no effect on the results of the furosemide test (p > 0.1). However, dexamethasone tended to decrease the basal plasma aldosterone concentration in the untreated patients, but not in the patients receiving spironolactone. In the ACTH test, the plasma aldosterone concentration increased significantly in the untreated patients (from 549.0 +/- 69.8 to 1169.3 +/- 165.5 ng/l, p < 0.01), but there was no significant aldosterone response in the spironolactone-treated patients (from 885.5 +/- 204.9 to 1260.3 +/- 289.2 ng/l, p > 0.1). We conclude that aldosterone secretion is mainly dependent on ACTH in the untreated patients with primary aldosteronism and is more strongly regulated by the renin-angiotensin system during spironolactone treatment.

Adrenocorticotropic Hormone↗

PubMed1994

[Effects of sex hormone on the dilatation of urinary tubule and acidophil body in NON mice].

The influences of sex hormones on the dilatation of the urinary tubules and acidophil bodies were histologically investigated in NON (Non-Obese Non-diabetic) mice. Although the dilatation of the proximal tubules and acidophil bodies in NON mice were observed only in female but not in male, a slight dilatation and a few bodies were also observed in castrated male NON mice. Moreover, in ovariectomized female NON mice the dilatation and bodies were less compared with intact female NON mice. Estradiol administration induced prominent dilatation and numerous acidophil bodies, while the administration of testosterone showed a complete preventive effect. Therefore, it is suggested that the dilatation of the tubules and the acidophil bodies can be profoundly influenced by sex hormones.

Animals↗

PubMed1994

Collagen gel contraction induced by retinal pigment epithelial cells and choroidal fibroblasts involves the protein kinase C pathway.

Contraction of intraocular fibrous membranes is an important feature in the pathogenesis of retinal detachment in proliferative vitreoretinopathy (PVR). Collagen gel contraction is a useful in vitro model of membrane contraction in PVR. We studied the role of protein kinase C (PKC) in collagen gel contraction induced by bovine choroidal fibroblasts and retinal pigment epithelial (RPE) cells. Collagen gels embedded with the cells were formed in culture dishes and gel contraction was evaluated. The PKC stimulator, phorbol 12-myristate 13-acetate (PMA), and the protein phosphatase 1 and 2A inhibitor, okadaic acid (OA), were used to evaluate the role of the PKC-mediated phosphorylation system in this gel contraction. Fifteen min incubation with PMA stimulated gel contraction, but 180 min incubation had no effect. Choroidal fibroblast- but not RPE cell-induced gel contraction was stimulated by OA. These effects were inhibited by the broad spectrum protein kinase inhibitor staurosporine and the specific PKC antagonist calphostin C. Transforming growth factor-beta (TGF-beta)1 and TGF-beta 2, which are known to be present in eyes with PVR, were evaluated to determine their effect on gel contraction. Both TGF-beta 1 and 2 had a stimulatory effect on contraction of gels seeded with choroidal fibroblasts and RPE cells, but staurosporine and calphostin C inhibited this TGF-beta-induced gel contraction. These results indicate that activation of PKC/protein phosphorylation is an important factor in gel contraction caused by choroidal fibroblasts and RPE cells, and that TGF-beta-induced gel contraction is mediated at least in part via the PKC pathway.

Animals↗

PubMed1994

[Echocardiographic assessment of cardiac basal hypertrophy represented by increased base to mid thickness ratio (B/M ratio) in the ventricular septum and its relation to age].

The basal part of the interventricular septum may easily become hypertrophic because it is exposed to strong hemodynamic stress compared to the other portions of the left ventricle. We measured the end-diastolic interventricular wall thickness both at the base and in the midsection by 2D echocardiography in 122 normotensives, and examined whether the basal thickness increases with age. The basal thickness (B) increased with age in both sexes. In males the thickness averaged 10.1 mm in the 50-59 age group, 10.2 m in those aged 60-69 and 11.4 mm (p < 0.01) in those 70 or older compared to 9.4 mm in those aged 49 or younger. In females it was 8.1 mm (p < 0.05) in the 50-59 age group, 8.3 mm (p < 0.05) in those aged 60-69 and 10.0 mm (p < 0.01) in those 70 or older compared to 6.8 mm in those 49 or younger. Concerning the midwall thickness (M), there were no significant changes among the respective age groups in either sex. As a result, a close correlation was found between the B/M ratio, a new and simple index for basal hypertrophy, and age (R = 0.46, p < 0.01 in males and R = 0.43, p < 0.01 in females). Comparison of the B/M ratio between the two age groups 49 or younger and 70 or older was as follows; 1.08 vs 1.30 (p < 0.01) in males and 1.01 vs 1.27 (p < 0.01) in females. Increase of basal hypertrophy in the aged was clearly indicated by the B/M ratio.

Adult↗

PubMed1994

Cerebrospinal fluid edema associated with shunt obstruction.

The authors report four hydrocephalic children with cerebrospinal fluid (CSF) edema extending along the ventricular catheter of an obstructed CSF shunt. Three of the patients exhibited massive CSF edema along the ventricular catheter, yet they manifested neither ventricular enlargement nor apparent periventricular CSF edema despite increased intraventricular pressure. These findings suggested ventricular tautness. The remaining patient, who had dilated ventricles with periventricular CSF edema, displayed CSF edema in a limited area along the ventricular catheter. Replacement of the obstructed peritoneal catheter of the shunt resulted in rapid improvement of the edema in all patients. In the three patients with massive CSF edema, however, a small lesion remained in the subcortical white matter along the ventricular catheter as demonstrated by computerized tomography and/or magnetic resonance imaging 3 to 5 years after shunt revision. It is concluded that shunt obstruction may result in massive CSF edema along the ventricular catheter in hydrocephalic children who have ventricular tautness after installation of the shunt causing irreversible although usually asymptomatic damage to the affected area of the brain.

Adult↗

PubMed1994

[Evaluation of the method of treating non-Hodgkin's lymphoma].

Forty-two patients with non-Hodgkin's lymphoma were treated between October 1983 and December 1992 in the department of Otolaryngology, Kagawa Medical School Hospital. The twenty-six of these patients whose tumor originated in Waldeyer's ring and who were diagnosed as Stage I or II have been reviewed. In principle, method of treatment was a combination of chemotherapy and radiotherapy. Between 1983 to 1987, COP was primarily used (9 cases) as combination chemotherapy, and after 1988 CHOP was used (17 cases). VAMA was used to treat the poor response and recurring cases. The five-year estimated overall survival rates calculated by the Kaplan-Meier method were 33.3% and 94.1% in the COP and CHOP groups, respectively. We investigated age, stage, cell type and grade, as factors related to recovery, but except for cell type, there were no significant differences in overall survival. The most serious side effect was decreased leucocyte count, but we prescribed G-CSF and were able to continue treatment.

Adult↗

PubMed1994

[Immunohistological study of dendritic cells and macrophages in sino-nasal lesions--distributions in metaplastic squamous epithelium and squamous cell carcinoma].

Dendritic cells, macrophages and lymphocytes infiltrating the epithelia of sino-nasal lesions were investigated immunohistochemically using antibody S-100 protein for dendritic cells, Ki-M1P for macrophages, MT1 for T-cells and L26 for B-cells, respectively. Seventy-five specimens of sino-nasal mucosae involving 51 cases of metaplastic squamous epithelium (MSE), 12 of inverted papilloma, 1 of atypical hyperplasia and 11 of squamous cell carcinoma (SCC) were studied. Dendritic cells were observed in 12 cases of MSE (23.5%), in 4 of inverted papilloma (33.3%), and in 6 of SCC (54.5%). More dendritic cells were found infiltrating MSE of the infective and fibrotic types than of the mild and edematous types, histopathologically. Furthermore, infiltration correlated with the degree of squamous differentiation in MSE, but not in SCC. The number of macrophages was significantly smaller in MSE than in columnar ciliated epithelium, while that in SCC was significantly greater than that in MSE. With dendritic cell infiltration macrophages in MSE as well as SCC and T-cells in and around the carcinoma were often increased. These findings suggest that dendritic cells may be attracted to maturative squamous epithelium, and may play an important role in the immunologic defence mechanisms of MSE. Dendritic cells, in contrast, may play a role in the cellular immune response of T-cells against the carcinoma.

Adolescent↗