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Biomedical subjects

T Saitoh

Publications and source records attributed to T Saitoh.

At least 289 records · Page 16Linked to original sources
PubMed1992

Localization of protein kinase C in human skeletal muscle.

The immunolocalization of protein kinase C (PKC) isozymes alpha, beta I and beta II, was investigated in human skeletal muscle. All three isozymes were present on the muscle fiber surface membrane and within the muscle fibers. The alpha-isozyme was most clearly delineated on the surface membrane of the muscle fiber and on small blood vessels in the connective tissue. The axons of myelinated intramuscular nerves stained intensely for the beta I isozyme, whereas the endoneurial connective tissue reacted more strongly for the alpha- and beta II-isozymes. PKC isozymes may regulate intracellular signal transduction in human skeletal muscle, as in the other tissues, but their exact role in muscle remains unknown.

Adult↗
PubMed1992

The role of alterations in free radical metabolism in mediating cognitive impairments in Down's syndrome.

Down's syndrome (DS) is a genetic disorder involving an excess of chromosome 21 (trisomy 21) in approximately 96% of the cases and comprises approximately 15% of the population with mental retardation (Heller, 1969). In addition to the constitutional mental deficiencies associated with the syndrome many DS patients develop dementia associated with Alzheimer's disease (AD) in their later years of life (Thase et al., 1984). The genetic locus for Cu,Zn-superoxide dismutase (SOD1), a key enzyme in free radical metabolism, is located on chromosome 21, and the activity level of this enzyme is elevated by approximately 50% in a variety of cells of DS patients (see Kedziora and Bartosz, 1988; Sinet, 1982). Because alterations in free radical metabolism may be involved in neuronal death and may be associated with a number of pathological manifestations of DS, it is important to understand the role of free radical metabolism in cognitive impairments of DS, the topic discussed in this chapter.

Aging↗
PubMed1992

Reverse flow in the intracranial arteries--the possible significance of comparative flow in the anterior cerebral and the basilar arteries.

Four infants with reverse flow patterns of the intracranial arteries are reported. Two with severe brain damage, had a reverse flow pattern in the anterior cerebral artery, which was recorded during the recovery stage from cardiac arrest. The other two patients showed a reverse flow pattern in the basilar artery and had a good prognosis. Reverse flow in the anterior cerebral artery suggests severe brain damage, but that in the basilar artery does not.

Basilar Artery↗
PubMed1992

Morphological characteristics of a transplantable nephroblastoma (NB-Y) in F344 rats and the relation of tumour growth to hyper-reninaemia in NB-Y-bearing rats.

A transplantable tumour, designated NB-Y, was established from a spontaneous nephroblastoma in an F344 rat. NB-Y was serially passaged in syngeneic rats by subcutaneous implantation up to the 49th generation. The transplants grew into nodules with an average diameter of 5 cm and average weight of 92.9 g 4 weeks after implantation. The primary tumour and NB-Y consisted mainly of sheets or clusters of undifferentiated blastemal cells, which reacted immunohistochemically for vimentin but not for keratin. Renin-containing cells were observed in the small blood vessel walls within the primary tumour, but neoplastic cells of both primary tumour and NB-Y failed to stain for renin. Plasma renin activity was significantly higher (40.7 ng per ml per h) in transplanted rats 4 weeks after implantation compared with non-transplanted controls (28.0 ng per ml per h). Hyperplastic juxtaglomerular cells were often observed in rats bearing NB-Y. Sinusoidal dilatation was present in the liver, adrenal glands, pituitary gland and bone marrow of recipients, suggesting abnormal blood flow provoked via the renin-angiotensin system. The present study revealed the development of hyper-reninaemia in NB-Y-bearing rats, but its pathogenesis remains unknown.

Anemia↗
PubMed1992

Alpha 2-adrenergic modulation of pancreatic glucagon secretion in rats.

The present study was designed to clarify the mechanism of adrenergic modulation of pancreatic glucagon secretion in rats under physiological conditions by 1) epinephrine infusion alone or together with adrenergic blockers and 2) administration of adrenergic agonists. Intravenous infusion of epinephrine alone (1 microgram/kg/min, equal to 0.7 nmol/kg/min) caused a significant increase in glucagon secretion. Phentolamine (an alpha blocker) or yohimbine (an alpha 2 blocker) administration completely inhibited the increase of glucagon secretion caused by epinephrine infusion, but neither the administration of bunazosin (an alpha 1 blocker) nor beta blockers inhibited it. Infusion of clonidine (an alpha 2 agonist) caused significant increase of glucagon secretion even at a low dose of 0.5 nmol/kg/min, although infusion of neither an alpha 1 nor a beta 2 agonist caused it even at the high dose of 40.0 nmol/kg/min. It is concluded that the alpha 2 receptor mechanism plays the most important role in the adrenergic modulation of glucagon secretion in rats under physiological conditions.

Adrenergic alpha-Agonists↗
PubMed1992

Balloon cystoscopy with neodymium:YAG laser.

We performed balloon cystoscopy for the diagnosis of gross hematuria as well as for the treatment of bladder tumor using the neodymium:YAG laser. Animal experiments were done to evaluate the efficacy of laser irradiation through the balloon, which proved to have the same effect as conventional laser irradiation. A total of 40 patients with bladder diseases was observed and treated by balloon cystoscopy, and the results were examined comparatively. Even with gross hematuria the structure of the mucosa and the tumor could be observed in detail without irrigating the inside of the bladder. Most bladder tumors were successfully treated with laser irradiation through the balloon through the optic lens system. Therefore, balloon cystoscopy appears to be a useful endoscopic modality in neodymium:YAG laser surgery for the treatment of bladder tumor.

Animals↗
PubMed1992

Simultaneous measurements of adenosine deaminase activity and tuberculostearic acid in pleural effusions for the diagnosis of tuberculous pleuritis.

Adenosine deaminase (ADA) activity and tuberculostearic acid (TSA) levels in pleural effusions were measured in 18 patients with active tuberculous pleuritis, 16 patients suspected of having tuberculous pleuritis, 14 patients with carcinomatous pleuritis, and 19 patients suffering from pleuritis of non-malignant and non-tuberculous etiology. In the patients with active tuberculous pleuritis, ADA was elevated in 56% and TSA was positive in 78%. In 83% of these patients, either ADA was elevated or TSA was positive. ADA was elevated together with a positive TSA in 50%. In contrast, TSA was positive in only 6% and ADA was elevated in 24% of the patients with non-tuberculous pleuritis, and none of these patients showed the combination of an elevation of ADA and a positive TSA. These results suggest that simultaneous measurements of both ADA and TSA in pleural effusions are useful for the diagnosis of tuberculous pleuritis.

Adenosine Deaminase↗
PubMed1992

Islet amyloid polypeptide/amylin in pancreatic beta-cell line derived from transgenic mouse insulinoma.

We examined the production and secretion of IAPP in a beta-cell line, MIN6, which is derived from an insulinoma obtained by targeted expression of the SV40 T-antigen gene in a transgenic mouse. RNA blot analysis revealed an abundance of IAPP and insulin II mRNA in the cells, findings comparable with those in the pancreas of a normal mouse. The presence of IAPP and insulin was confirmed immunohistochemically and by RIA. Analysis of the reverse-phase HPLC identified IAPP in cells with authentic mouse IAPP. Raising the glucose concentration from 5.6 to 25 mM failed to induce increments in IAPP and insulin II mRNAs. The cells secrete IAPP and insulin for short- and long-term incubations in response to concentration of glucose in the medium. These features resemble those of islet cells from normal animals. This beta-cell line will aid in analyzing the regulation of IAPP gene expression and the mechanisms of IAPP biosynthesis and secretion.

Amyloid↗
PubMed1992

Histological characteristics of lupus nephritis in F1 mice with chronic graft-versus-host reaction across MHC class II difference.

Renal lesions at the chronic phase of MHC class-II-disparate graft-versus-host reaction (GVHR) were examined. To induce GVHR, C57BL/6 (B6) spleen cells were injected twice into either (B6 x bm12)F1 (class-II-disparate), (B6 x bm1)F1 (class-I-disparate) or (bm1 x bm12)F1 mice (class-I + II-disparate). For comparison, (C57BL/10 x DBA/2)F1 (BDF1) mice injected with DBA/2 spleen cells were also used. (B6 x bm12)F1 and BDF1 recipients showed marked elevation of anti-DNA antibodies, circulating immune complexes (CIC) and the number of immunoglobulin producing cells (IgPC). At 20 weeks after cell injection, severe immune complex glomerulonephritis (ICGN) was observed in (B6 x bm12)F1 recipients, but was far less severe in (bm1 x bm12)F1 recipients and was not observed in (B6 x bm1)F1 recipients. ICGN was also observed in BDF1 recipients at 12 weeks after cell injection. By immunofluorescent microscopy, IC deposition was detected along the capillary loops and also in the mesangial area in (B6 x bm12)F1 recipients, while BDF1 recipients showed only a capillary pattern. By light microscopy, the renal lesion of (B6 x bm12)F1 recipients appeared similar to those of BDF1 recipients. Histologically, (B6 x bm12)F1 recipients serve as a good model for lupus glomerulonephritis induced by class-II-disparate GVHR.

Animals↗
PubMed1992

[The pathogenesis of hypercalciuria from the aspect of the response to human parathyroid hormone in Ca containing stone formers].

In order to clarify the pathogenesis of hypercalciuria, the response to extrinsic human parathyroid hormone (h-PTH) was studied the 21 patients with calcium containing urinary stone(s) and 5 normal controls (NO). The stone patients were classified into 3 groups from the result of the oral calcium loading test, i.e. Non-hypercalciura (NH, n = 8) and absorptive hypercalciuria (AH, n = 8) and renal hypercalciuria (RH, n = 5). Only in the AH group, urinary excretion of calcium (u-Ca) was strongly correlated to that of sodium (u-Na) in pre-load of h-PTH, and both increments were also correlated in post-load of h-PTH. As of this fact the increase in Na excretion seems to be responsible for a cause of hypercalciuria in the AH group. There was a significant correlation between the value of %TRP in pre-load of h-PTH and the rate of urinary phosphorus (P) increment between pre-load and post-load of h-PTH in the NO and NH groups. However, this relationship was not found in the AH and RH groups. These findings indicate that there is response disorder of P to h-PTH. In addition, serum P was low, plasma 1,25 (OH)2D was high, N-c-AMP was low in the AH group, whereas both serum P and %TRP were low in the RH group in pre-load of h-PTH. These findings are compatible with the primary renal P leak.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Ultrastructural renal damage after shock wave exposure].

This report clarified the direct damage to renal cell ultrastructure on shock wave exposure. The renal cortex of the rabbit was exposed to the shock waves (1200 bar) generated by the piezo-ceramics. The change was examined by electron microscopy immediately after 20 shots exposure and 500 shots exposure as well as one week after 500 shots exposure. In all groups, the most critical damage was observed in the proximal tubule. Immediately after 20 shots exposure, large vacuoles were found to be enclosed by infoldings in the proximal tubular cell. The damaged cell lost its brush border and jutted out into the lumen. The ruins of organelles (nuclei, mitochondria, etc.) were seen in the lumina of proximal and distal tubules. The damage progressed, in the 500 shots exposure group, to include the distal tubular cytoplasm. One week after the 500 shots exposure, a few of atrophic tubular cells were found in wide scars. The tubular cell which contained a deformed nucleus and destroyed organelles was desquamated from the basement membrane. The change in the tubular cell after shock wave exposure was apparently different from that after such intervention as one hour ischemia. It was concluded that the direct damage to renal cells by underwater shock wave exposure was really present.

Animals↗
PubMed1992

[Clinical experience of local thermotherapy in the treatment of benign prostatic hyperplasia].

Thirty-five patients with benign prostatic hyperplasia (age range: 45-88 years; average: 67.5 years) underwent local thermotherapy with prostathermer. Clinical therapeutic effect was evaluated in 30 of the 35 patients: 2 patients interrupting from therapy and 3 receiving pretherapeutic indwelling catheters were not included. A total of 6 treatments (2 per week) were performed, each lasting for 60 minutes. As for subjective improvement, improvement of nocturia was noted in 70.0% of all patients and sense of residual urine in 70.7%. Post-therapeutic nocturnal and daytime decreases in urination frequency were statistically significant (p less than 0.01). Objective improvement in residual urine volume occurred in 19 of the 30 cases, and elevation in uroflowmetric maximal flow rate following therapy was statistically significant (p less than 0.05). Among complications ascribable to catheter insertion were urethral bleeding (3 cases), epididymitis (1 case) and pyuria (1 case). Therapeutic result based primarily on subjective symptoms and partly on objective findings was fairly good in 17 cases (about 57%), and slightly good in 25 cases (about 83%). In conclusion, this therapy seems to be useful in the treatment of benign prostatic hyperplasia.

Aged↗
PubMed1992

[Calcium-dependent signaling of acid secretion in isolated parietal cells from guinea pigs and its modification by ethanol].

Treatment of isolated parietal cells from guinea pig gastric mucosa with ethanol caused a rapid increase in [Ca2+]i and concomitant decrease in the capacity for carbachol-stimulated acid secretion in a dose dependent manner. Carbachol rapidly increased the [Ca2+]i from trimethoxybenzoic acid 8-(diethylamino)-octyl ester sensitive intracellular pool. In contrast, the increase with ethanol was through La3+ sensitive Ca2+ channel from external source, which suppressed the Ca2+ response subsequently stimulated with carbachol. Pretreatment of the cells with EGTA or La3+ completely prevented the elevation of [Ca2+]i with ethanol and preserved the Ca2+ response to carbachol. These findings indicate that ethanol-induced elevation of [Ca2+]i may desensitize the stimulation of carbachol. Furthermore, treatment of the parietal cells with ethanol increased the activity of protein kinase C in both cytosolic and membrane fractions of the cells. Activation of protein kinase C with phorbol diester suppressed the capacity for acid secretion. These results suggest that ethanol may inhibit the carbachol-stimulated acid secretion through the desensitization of Ca2+ response and the activation of protein kinase C.

Animals↗
PubMed1992

[A case of systemic arterial supply to normal lung without sequestrated lung].

A 19-year-old man was admitted to our hospital because of bloody sputum. His chest radiograph showed funicular shadows adjacent to the descending aorta in the left lower lobe and absence of vascular structures in the lower portion of the left hilum. His chest CT showed increased vascularity and slightly increased parenchymal density in the left basal segments. No cystic lesions were observed on CT. Angiographic examinations revealed that the left basal segments were supplied by an aberrant artery arising from the thoracic aorta, instead of the pulmonary artery. Left lower lobectomy was performed. Gross findings at surgery and histological examination confirmed the diagnosis of systemic arterial supply to normal lung without sequestrated lung. The main histological findings of the specimen were hemorrhage in alveolar spaces and dilatation of vessels. These findings seemed to correspond to the CT findings. We consider that CT is useful for the diagnosis of this disease.

Adult↗
PubMed1992

[Clinical use of the measurement of functional residual capacity during non-panting breathing--study on healthy subjects and respiratory patients].

The functional residual capacity (FRC) has been measured by gas dilution technique (GA) and body plethysmographic technique (BP) using the panting maneuver (PA). However, this maneuver is difficult to perform for patients who experience discomfort in breathing, and in cases of chronic obstructive pulmonary diseases, the FRC value measured by panting maneuver overestimates the true FRC value. Thus, in order to minimize these factors, we measured FRC during non-panting breathing (NP) using a BP device (BX-82, Minato Co., Osaka) and compared the results with the usual two methods. One hundred healthy subjects (Group I), 72 patients with restrictive ventilatory disorder (Group II, %VC = 62.7%) and 66 patients with pulmonary emphysema (Group III, FEV1.0% = 44.9%) were studied. All measurements were performed under 0.5 Hz respiratory frequency. The non-panting FRC measurement was performed by closing the mouth shutter of the BP for about 500 msec at the end of both the expiratory and inspiratory phase. From the box volume change and mouth pressure change, lisajous curves were formed and fitted by linear regression method. From this regression line, the volume of FRC was calculated. The obtained data had no significant differences among them, and there was a significant relationship between each technique. The correlation coefficient of non-panting breathing technique in Group III was slightly poor compared with the other techniques, and we therefore tried to re-classify Group III into small groups according to the severity of obstruction. It was subsequently found that this technique did not have the tendency to give a higher FRC value with increase in obstructive disorder.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Delayed sternal closure after cardiac surgery].

Following cardiac surgery, approximation of sternum will produce systemic hypotension or elevation of left atrial and central venous pressures. A new criteria for delayed sternal closure is proposed. Sternal closure has to be delayed when mean left atrial or central venous pressures increased over 2 mmHg at the tentative closure. In seven cases (3.5%) of consecutive 201 patients was delayed the sternal closure under the above mentioned state, all survived and received the successful closure later. One of them died of congestive heart failure four months after the operation and one died of the rupture of the ascending aortic pseudoaneurysm eleven months after the initial operation. Microbiological examination of the mediastinal and pericardial contents obtained at the final sternal closure were negative in all cases. Comparing the total cardiopulmonary bypass time, ventricular fibrillation time, and myocardial ischemic time between in the secondary closure group and in the primary closure group, the total bypass time and the ventricular fibrillation time of the former were significantly longer than the latter, but the ischemic time revealed no difference. In conclusions, persistent elevation of left atrial or central venous pressures after cardiac surgery at the tentative sternal closure seems the reliable predictor for the delayed closure of the sternum. Careful post-operative management prevents serious mediastinal infection. Delayed sternal closure is preferable procedure for the patient with brittle hemodynamics after open heart surgery.

Adult↗
PubMed1992

Casein kinase II alteration precedes tau accumulation in tangle formation.

Previous studies have shown altered casein kinase II (CK-II) in Alzheimer's disease (AD). For the present study, the authors analyzed CK-II immunoreactivity at various stages of tangle formation using quantitative laser confocal microscopy and immunoelectron microscopy. AD hippocampal pyramidal cells without neurofibrillary tangles (NFTs) displayed 15% more anti-tau immunoreactivity (P less than 0.01) and 43% more anti-CKII immunolabeling than controls (P less than 0.001). In AD, tangle-bearing hippocampal neurons with strong anti-tau immunoreactivity (threefold increase from controls) showed a significant 22% increase in anti-CKII immunolabeling (P less than 0.01), compared with those without NFTs. Neurons with early neurofibrillary changes showed diffuse anti-CKII immunostaining in their cytoplasm and cell processes. In tangle-bearing neurons, in which a higher level of tau immunoreactivity was detected, anti-CKII immunolabeling was distributed along a fibrillar meshwork in cell bodies and processes. Linear regression analysis of anti-CKII and anti-tau immunoreactivity in AD showed a positive correlation (r = 0.53, P less than 0.001). At the ultrastructural level, anti-CKII was immunolocalized to the paired helical filaments (PHF) of the tangle-bearing neurons, as well as to PHF in neuropil threads and some dystrophic neurites in plaques. These results suggest a possible role for CK-II in tangle formation.

Aged↗