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Biomedical subjects

H Kawamura

Publications and source records attributed to H Kawamura.

At least 217 records · Page 12Linked to original sources
PubMed1993

Differential regional hemodynamic changes produced by L-glutamate stimulation of the locus coeruleus.

The locus coeruleus (LC) exerts an inhibitory influence on the cardiovascular system. Microinjection of the excitatory amino acid, L-glutamate, into the LC elicits a decrease in arterial pressure as a result of a decrease in total peripheral resistance (TPR). The aim of the present study was to examine the role of the LC in the regulation of the regional hemodynamics. Employing anesthetized rats, the blood flow to the renal, mesenteric and hind-limb vascular beds was measured with an electromagnetic flowmeter. The changes in regional blood flow and vascular resistance evoked by chemical stimulation of the LC were examined separately in each region. During the depressor response elicited by LC stimulation, the hind-limb and renal vascular resistance was significantly decreased, while the mesenteric resistance was unchanged. The vasodilatation appeared to be more prominent in the hind-limb muscle than in the systemic circulation. Renal nerve denervation attenuated the decrease in renal vascular resistance elicited by LC stimulation. However, a small part of this response still remained in the denervated kidney. The present results suggest therefore that: (1) LC neurons exert differential hemodynamic effects on the hind-limb muscle, renal and mesenteric vascular beds; (2) the largest contribution to the decrease in TPR is related to vasodilatation in the hind-limb muscles; and (3) the renal vasodilation elicited by LC stimulation is not mediated solely by the renal innervation.

Animals↗
PubMed1993

Patellar metastases. A report of two cases.

Primary bone tumours and metastases of the patella are rare. We report two cases of metastases, one from a carcinoma of the salivary gland which was bilateral and the other from extramammary Paget's disease with invasive carcinoma.

Adult↗
PubMed1993

Ultrastructure and morphometry of testicular Leydig cells and the interstitial components correlated with testosterone in aging rats.

The ultrastructure of testicular interstitium in young and aged adult rats was analysed using morphometric methods, and the plasma testosterone concentration was measured. With increasing age there was an augmentation in the volume of collagen fibrils in the intercellular matrix and in blood vessels. During the aging process (approximately two years) the average volume of the Leydig cell decreased from 1364 microns 3 to 637 microns 3, but the number of Leydig cells in paired testes increased from 53 x 10(6) to 113 x 10(6). The absolute volume of smooth surfaced endoplasmic reticulum (SER) per Leydig cell amounted in aged rats to 78% of that in young adult rats. The total amount of SER in paired testes increased by 62% with aging. The present analysis suggests that the ability of SER to maintain peripheral testosterone concentration decreases with age. In young adult rats the absolute volume of peroxisomes per Leydig cell correlated significantly with the concentration of testosterone in blood and also with the absolute volume of SER per Leydig cell. These results combined with ultrastructural observations of close apposition of peroxisomes and SER suggest that peroxisomes have a role in testosterone secretion by Leydig cells.

Aging↗
PubMed1993

Titanium lymph node pigmentation in the reconstruction plate system of a mandibular bone defect.

A case of titanium pigmentation that involved a submandibular lymph node is reported. A 41-year old man had been treated for ameloblastoma by partial resection of the mandible followed by reconstruction with the use of a titanium plate to bridge the mandibular defect. Titanium pigmentation occurred in the surrounding soft tissue adjacent to the plate and within a submandibular lymph node 2 years after reconstruction.

Adult↗
PubMed1993

Immunohistochemical detection of proliferating cell nuclear antigen (PCNA)/cyclin in human prostate adenocarcinoma.

Tissue specimens from 12 patients with adenocarcinoma of the prostate and 7 patients with benign prostate hypertrophy were stained by an indirect immunoperoxidase method using antiproliferating cell nuclear antigen (PCNA) monoclonal antibody. The PCNA labeling index was determined by counting the number of PCNA-labeled cells in the tissue sections. Average PCNA labeling index of the benign prostate hypertrophy was 1.2 +/- 0.5%. Poorly differentiated tumors averaged 7.6 +/- 3.9% labeling versus 4.6 +/- 1.3% in moderately differentiated tumors, and well differentiated tumor in the series had a PCNA labeling index of 2.5 +/- 0.9%. The PCNA labeling indices for atypical hyperplasia were 1.9, and 4.1%, respectively. Our preliminary results suggest that the measurement of PCNA labeling index in prostate cancer may prove to be a new objective and quantitative assay of biological potential of individual tumor.

Adenocarcinoma↗
PubMed1993

The effect of androgen and estrogen on secretory epithelial cells and basal cells of the rat ventral prostate after long-term castration.

After long-term castration, rats were injected with cotton seed oil, testosterone- and estradiol-17 beta-cypionate (CS, TC and EC). The height of the epithelial cells of the ventral prostates from the castrated rats increased after TC and EC-injection. The secretory and basal cells formed two layers of epithelium, an inner layer near the lumen with pale nuclei and another layer with dark nuclei. These two layers could result from a reduction of secretory epithelial cells. Castration decreased the ratio of secretory cells to basal cells (S/B). TC-injection increased the ratio of S/B because of the secretory epithelial cell growth. Longer dark cells may be transient cells, appearing during the differentiation of basal cells into secretory epithelial cells. A sheet branching off from the basal lamina was observed. Androgen may stimulate the synthesis of the lamina, but whether it induces the synthesis or turnover of the basal lamina has not been established. EC increased the ventral prostatic weight and secretory epithelial cell height and induced the appearance of crystalline granules. Increase in S/B ratio may result from an increase in the secretory epithelial cells, but not from basal cell multiplication due to squamous metaplasia. The ratio is significantly correlated to the weight of the ventral prostate, but not to the secretory epithelial cell height. Its value could indicate the multiplication of secretory epithelial cells, differentiation of basal cells into epithelial cells, or both. It is probable that basal cells do not change in number, but control the size of the rat ventral prostate in response to the hormone level.

Animals↗
PubMed1993

Effects of alpha,beta-blocker, arotinolol chloride, on 24-h blood pressure--difference between elderly and younger hypertensive patients.

To assess the effect of age on the circadian blood pressure (BP) after an alpha,beta-adrenergic blocker, the ambulatory BP was measured before and after arotinolol chloride administration in nine younger (mean age 49.1 years) and 14 older (72.1 years) patients with essential hypertension. After a 4-week control period, arotinolol chloride was administered twice daily (08:00 and 20:00 hours) for 8 weeks and the ambulatory BP was measured non-invasively at the end of the control and treatment period. Arotinolol significantly reduced the daytime systolic BP from 152.3 to 140.9 mmHg (P < 0.05) and night-time systolic BP from 137.3 to 122.3 mmHg (P < 0.01) in the younger hypertensive patients. In contrast, in the older group, the night-time systolic BP did not show a significant change, although the daytime systolic BP was significantly reduced from 155.0 to 142.2 mmHg (P < 0.02). Diastolic BP in both groups was significantly reduced by arotinolol during the day and night. Night-time reduction of BP was significantly less in the older group (-8.6 vs -15.1 mmHg for the systolic pressure P < 0.01; -5.8 vs -9.8 mmHg for the diastolic pressure P < 0.01).

Adrenergic beta-Antagonists↗
PubMed1993

A simple system for stereotactic volumetric resection.

Stereotactic volumetric resection of deep-seated intracerebral lesions is generally believed to require expensive and complex facilities. The authors report a simple system for stereotactic craniotomy, in which the software in the computed tomographic scanner and a personal computer are used for preoperative planning and intraoperative orientation.

Brain Neoplasms↗
PubMed1993

Application of enzyme-linked immunosorbent assay for the seroepizootiological survey of antibodies against porcine cytomegalovirus.

Enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies against porcine cytomegalovirus (PCMV) was developed using the OF-1 strain of PCMV as an antigen. Results of the ELISA were compared to those of indirect fluorescent antibody (IFA) and serum neutralization (SN) tests. ELISA and IFA test were found to be extremely sensitive more than SN test. All of 11 tested sera were highly reactive in both ELISA and IFA test, but 6 of them were antibody-negative in the SN test. The retrospective survey of 436 fattening pig sera collected in Japan in 1981 showed that 433 (99.4%) of them were highly antibody-positive in ELISA.

Animals↗
PubMed1993

[The dose-response study of sparfloxacin against skin and soft tissue structure infections in the field of surgery].

Sparfloxacin (SPFX), a new oral quinolone antimicrobial, was evaluated for the clinical efficacy against skin/soft tissue structural and osteomyelitic infections. SPFX was administered to a total of 101 patients with various infections such as infected atheroma, periproctal abscess, subcutaneous abscess, wound infections, felon, cellulitis, furuncle, pilonidal sinus, sappurative mastitis, lymphangitis, hemorrhoidal fistula, osteomyelitis. The clinical efficacy in the evaluable 101 cases was assessed by the physician in charge as excellent in 19 cases, good in 64, fair in 11 and poor in 7, the efficacy rate being 82.2%. In contrast, the clinical efficacy in 101 evaluable cases by the criteria of the committee as excellent in 36 cases, good in 45, fair in 8, and poor in 12, the efficacy rate being 80.2%. Clinical efficacy rating was not significantly difference between 200 mg/day group and 300 mg/day group. The bacteriological eradication rate was 86.5% in 53 cases with monomicrobial infection and 90.3% in 33 cases with polymicrobial infections. Of 18 cases whose infections were previously intractable with other drugs and treated thereafter with SPFX, 15 were judged in the efficacy as excellent or good. The side effects observed in 2 cases during the treatment were epigastralgia and nausea which were tolerable and did not require withdrawal of SPFX. No abnormal laboratory value was found in the several required tests. The MIC values measured for 108 strains (90.0%) of 120 clinical isolated of 35 species were lower than 0.78 microgram/ml.

Administration, Oral↗
PubMed1993

[A coronary aneurysm of left main trunk associated with localized dissecting aneurysms of thoracic and abdominal aorta].

A 47-year-old man who had undergone surgery of a dissecting thoracic aortic aneurysm was admitted for a localized, dissecting abdominal aortic aneurysm. Preoperative coronary arteriogram incidentally showed a coronary artery aneurysm (CAA) of the left main trunk. Prior to the operation for abdominal aortic aneurysm, that for the CAA was performed under standard cardiopulmonary bypass conditions with antegrade and retrograde coronary sinus cold blood cardioplegia. A longitudinal incision of the aneurysmal wall was made for the removal of a small thrombus and, the ostia of the left anterior descending artery (LAD), circumflex artery (LCX), intermediate artery (IM) and main trunk were closed from the inside of the aneurysm. The aneurysmal wall was closed without resection of the whole aneurysm. Finally, coronary artery bypass grafting to LAD, LCX and IM was performed. Postoperative course was uneventful with patency of all grafts. The retrograde coronary sinus cardioplagia is effective to prevent thromboembolism of distal coronary arteries due to the antegrade cardioplagia.

Adult↗
PubMed1993

[Surgical treatment of double-outlet right ventricle with left ventricular outflow tract obstruction].

Three patients with double-outlet right ventricle (DORV) and left ventricular outflow tract obstruction (LVOTO) were described. In each patient, LVOTO was produced by restrictive VSD which resulted from malalignment of the conal musculature and a discrete subaortic membrane. All patients underwent surgical repair with enlargement of the ventricular septal defect and rerouting of the outflow tract from the left ventricle to the aorta. One patient died of congestive heart failure three months postoperatively. Causes of LVOTO and surgical management of DORV with LVOTO were discussed.

Cardiac Surgical Procedures↗
PubMed1992

Age-related changes in radial-arm maze learning and basal forebrain cholinergic systems in senescence accelerated mice (SAM).

Age-related changes in learning performance and the brain cholinergic system were studied in a senescence accelerated mice-prone series (SAM-P/8) and a senescence accelerated mice-resistant series (SAM-R/1, control) bred under specific pathogen-free conditions. In a radial-arm maze task, SAM-P/8 mice at 4 and 12 months of age showed virtually no significant impairment in working memory or reference memory compared with SAM-R/1 mice at the same age, although they needed more time to complete a trial than SAM-R/1. In contrast, in a passive avoidance task, SAM-P/8 showed a marked age-accelerated deficit in acquisition performance relative to SAM-R/1. Also, SAM-P/8 showed an age-accelerated decrease in locomotion and rearing in an open-field box. At the end of these behavioral tasks, neurochemical analyses showed that there were no differences in the concentrations of acetylcholine (ACh) in the cortex, hippocampus, striatum, midbrain, or cerebellum between SAM-P/8 and SAM-R/1. Although SAM-P/8 mice did not demonstrate any age-accelerated decline in radial-arm maze performance, they showed a normal age-related decline particularly in working memory, equal to that observed in SAM-R/1. Also, ACh levels in the aged groups of SAM-P/8 showed a significant decrease related to normal aging in the hippocampus and striatum, and a slight decrease in the cortex compared to the young group of the same strain. Thus, we found that SAM-P/8 show dissociative effects of aging in spatial learning and passive avoidance performance.

Aging↗
PubMed1992

A novel monoclonal antibody against carbohydrates of L1 cell adhesion molecule causes an influx of calcium in cultured cortical neurons.

We have studied the function of carbohydrates of the L1 molecule, a member of the immunoglobulin superfamily of adhesion molecules, using a novel monoclonal antibody, mAb-L1(2E12), against L1 molecule. This antibody was specific for the 200 kDa component of mouse L1 molecule and its epitope was N-linked for complex-type oligosaccharides. The mAb-L1(2E12) was found to induce a rise in intracellular Ca2+ concentration ([Ca2+]i) in cultured mouse embryonic cortical neurons. The rise in [Ca2+]i was dependent on the concentrations of mAb-L1(2E12). The rise seemed to be due to an influx of extracellular Ca2+ as EGTA treatment abolished it. Both cadmium and nifedipine blocked the effect of mAb-L1(2E12), suggesting the Ca2+ influx was through voltage-operated Ca2+ channels, particularly L-type Ca2+ channels. These results provide an important insight for understanding the mechanisms by which oligosaccharides of the L1 molecule influence various functions of neural cells.

Animals↗
PubMed1992

Immunoreactive corticotropin-releasing hormone levels in the hypothalamus of female Wistar fatty rats.

We have studied immunoreactive corticotropin-releasing hormone (CRH) levels in the hypothalamus of female Wistar fatty rats, a strain with the fa gene transferred from the Zucker rat to the Wistar Kyoto rat, in an attempt to understand the role of CRH in the development of obesity. A study was conducted with 5-week- and 12-week-old female Wistar fatty rats and lean littermates. There was no significant difference in hypothalamic CRH levels between lean and obese rats at the age of 5 weeks (1887 +/- 99.6 vs. 1767 +/- 124 pg/tissue; mean +/- S.E.M.). Hypothalamic CRH immunoreactivities, however, were significantly lower in 12-week-old obese rats (2361 +/- 132 pg/tissue) than those in lean littermates (2992 +/- 118 pg/tissue; P less than 0.05). The difference of CRH contents between the lean and obese group becomes apparent as they grow up and develop obesity.

Aging↗