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Biomedical subjects

H Itoh

Publications and source records attributed to H Itoh.

At least 739 records · Page 41Linked to original sources
PubMed1995

Stenosis enhances role of platelets in growth of regional thrombus and intimal wall thickening in rat carotid arteries.

The authors present the results of a study in which stenosis was induced, resulting in either thrombus or intimal wall thickening, in rat carotid arteries. At > or = 75% stenosis in mildly denuded arteries, an acute and occlusive thrombus formation was induced, but the thrombus was significantly reduced in thrombocytopenia. Thrombus formation near the site of stenosis decreased with decreasing degree of stenosis, whereas the percent formation in the distal region (percent total thrombus) increased. Numerous mural platelet microthrombi were noted at the distal region of the stenosed arteries. After chronic 50% stenosis of the carotid artery for 2 weeks, significant intimal thickening was observed, without any occlusive thrombus formation. The combination with mild denudation was critical in eliciting the effect of stenosis. The magnitude of intimal growth in the stenosed artery was marked by day 6 and plateaued thereafter, whereas it was slight in nonstenosed arteries. The 5-bromodeoxyuridine index of the cells of the medial layer at day 3 was significantly increased by the stenosis, and the effect was reversed in thrombocytopenia. Complete reendothelialization of the intimal surface was observed by 7 to 10 days after surgery in the stenosed arteries. These findings suggest that the introduction of stenosis in these arteries enhances the interaction of platelets with the damaged arterial walls under abnormal fluid shear and that this enhancement leads to acute and occlusive thrombus formation associated with more marked stenosis as well as to sustained increase of intimal wall thickness in less marked stenosis.

Animals↗
PubMed1995

Pulmonary lymphangioleiomyomatosis: a report of 46 patients including a clinicopathologic study of prognostic factors.

The clinical and pathologic features of 46 patients from Japan, Korea, and Taiwan with pulmonary lymphangioleiomyomatosis (LAM) were studied. Only two (5%) among 40 evaluable treatments were assessed to be effective. Some prognostic factors of LAM were recognized. A reduction of the forced expiratory volume in one second/forced vital capacity (FEV1/FVC) ratio was a poor prognostic factor at 2 yr after the first examination, with a statistically significant difference (p < 0.05). An increase in the percentage of predicted total lung capacity (%TLC) correlated with a poor prognosis at 2, 3, and 5 yr after the first examination, with statistically significant differences (p < 0.05). Histologically, two types of pulmonary lesions were observed; a predominantly cystic type and a predominantly muscular type. Patients with predominantly cystic LAM lesions showed a tendency to a poor prognosis from 2 to 5 yr after the biopsy. Among open lung biopsy findings, higher grades of abnormal areas were unfavorable as a prognostic factor from 2 to 5 yr after the biopsy, with statistically significant differences (p < 0.05). Higher grades of cystic lesions correlated inversely with survival at 2, 4, and 5 yr after the lung biopsy, with statistically significant differences (p < 0.05).

Adult↗
PubMed1995

Rapid transcriptional activation and early mRNA turnover of brain natriuretic peptide in cardiocyte hypertrophy. Evidence for brain natriuretic peptide as an "emergency" cardiac hormone against ventricular overload.

We previously demonstrated that brain natriuretic peptide (BNP) is a cardiac hormone mainly produced in the ventricle, while the major production site of atrial natriuretic peptide (ANP) is the atrium. To assess the pathophysiological role of BNP in ventricular overload, we have examined the gene expression of BNP, In comparison with that of ANP, in a model of cardiac hypertrophy using cultured neonatal rat ventricular cardiocytes. During cardiocyte hypertrophy evoked by endothelin-1, Phenylephrine, or PMA, the steady state level of BNP mRNA increased as rapidly as the "immediate-early" induction of the c-fos gene expression, and reached a maximal level within 1 h. Actinomycin D, a transcriptional inhibitor, completely diminished the response, while the translational blocked with cycloheximide did not inhibit it. In contrast, ANP mRNA began to increase 3 h after the stimulation, and accumulated during cardiocyte hypertrophy. The BNP secretion from ventricular cardiocytes was also stimulated, more rapidly than the ANP secretion. Furthermore, the turnover of BNP mRNA was significantly faster than that of ANP mRNA, being consistent with the existence of AUUUA motif in the 3'-untranslated region of BNP mRNA. These results demonstrate that the gene expression of BNP is distinctly regulated from that of ANP at transcriptional and posttranscriptional levels, and indicate that the characteristics of the BNP gene expression are suitable for its possible role as an " emergency" cardiac hormone against ventricular overload.

Animals↗
PubMed1995

Inhibitory effect of beta-glucosyl-phenolic hydroxamic acids against urease in the presence of microfloral beta-glucosidase.

Three glucosyl-phenolic hydroxamates, 4-O-(beta-D-glucopyranosyl) benzohydroxamic acid, 4-O-(beta-D-glucopyranosyl)hippuric hydroxamic acid, and 3-[4-O-(beta-D-glucopyranosyl)phenyl]propionohydroxamic acid (Glc-PPHA), were hydrolyzed to their corresponding aglycones by beta-glucosidase of intestinal flora of rat without any major adverse hydrolysis in vitro. Inhibitory potency of these glucosyl-hydroxamates on urease was recovered to the same extent as that of the corresponding aglycone hydroxamates by preincubation for 2h with rat intestinal flora. p-Hydroxyphenylpropionohydroxamic acid inhibited noncompetitively jack-bean urease activity and its glucose-ligated form, Glc-PPHA inhibited it competitively. A single oral dose of Glc-PPHA tended to inhibit urease activity in proximal colon contents of rat at 6 h after administration (p = 0.06). After 14C-urea was orally administered to rat, 14CO2 was collected for to measure the ureolysis in vivo. Expired 14CO2 was limited to 40% by a single oral dose of Glc-PPHA during 6 h, and 75% of intestinal ureolysis was repressed during the first 1 h in the breath test.

Animals↗
PubMed1995

Antitumor active fucoidan from the brown seaweed, umitoranoo (Sargassum thunbergii).

Neutral and acidic polysaccharides and their protein complexes were fractionated and purified from the brown seaweed umitoranoo (Sargassum thunbergii) by fractional extraction, iron-exchange chromatography, and gel filtration. Thirty-one polysaccharide fractions were obtained and tested for antitumor activity in mice with Ehrlich carcinoma transplanted i.p. Two of the fractions, GIV-A ([alpha]25D -127 degrees and mol. wt., 19,000) and GIV-B ([alpha]25D -110 degrees and mol. wt., 13,500) had such activity. On the basis of chemical and spectral analyses, these compounds were found to be a fucoidan or L-fucan containing approx. 30% sulfate ester groups per fucose residue, about 10% uronic acid, and less than 2% protein.

Animals↗
PubMed1995

Plasma brain natriuretic peptide concentrations in healthy children from birth to adolescence: marked and rapid increase after birth.

The aim of the present study is to establish the normal range and to determine the developmental changes of plasma brain natriuretic peptide (BNP) concentrations in children. We measured plasma BNP concentrations as well as atrial natriuretic peptide (ANP) concentrations in 58 healthy children from birth to adolescence and in the umbilical vein of 20 healthy neonates using highly sensitive immunoradiometric assays. The plasma BNP concentration was the highest at 0 days of age and descended through maturation to be almost constant and to be at the adult level at 3 months of age. The plasma BNP concentration at 0 days of age (56.7 +/- 49.6 fmol/ml; mean +/- SD) was 25 to 30 times higher than the adult level and 21 times higher than that in the umbilical vein (2.7 +/- 1.4 fmol/ml). The plasma ANP concentration at 0 days of age was not significantly different from that in the umbilical vein. The ratio of BNP to ANP was also the highest at 0 days of age (1.39 +/- 0.72) and decreased through maturation to be at the adult level at 3 months of age. Thus, the plasma BNP concentration in healthy subjects showed a marked, rapid and preferential increase immediately after birth, suggesting that BNP has a physiological role distinct from that of ANP in the perinatal circulatory changes from fetus to neonate.

Adolescent↗
PubMed1995

[The control of smooth muscle tissues by nonadrenergic noncholinergic (NANC) nerve fibres in the autonomic nervous system].

Smooth muscle cells distributed in the visceral organs are under the control of the autonomic nervous system, and contraction or relaxation of the muscle cells plays an important physiological role in the control of blood pressure, motility of the digestive, respiratory and urinary tracts and secretion. Recent physiological, pharmacological and histochemical investigations indicate that neurotransmitters other than acetylcholine or noradrenaline are involved in peripheral autonomic neuro-effector transmission, and these neurotransmitters are generally termed non-adrenergic, non-cholinergic (NANC) neurotransmitters. The neurotransmitters responsible for excitatory and inhibitory NANC neurotransmission (e-NANC and i-NANC respectively) have not been conclusively identified, but ATP, nitric oxide (NO) and peptides such as VIP and substance P are candidates for these roles. In this review, we discuss the possible role of ATP and NO as e- or i-NANC neurotransmitter in the digestive, respiratory and urinary tracts. Much of the work on NANC innervation in the digestive tract has been carried out on the circular muscle layers of the ileum. This receives inhibitory NANC innervation with ATP responsible for fast relaxation and VIP, and possibly NO, for the slow response. Early and late excitatory junction potentials can be recorded in the presence of atropine. The second is due to substance P since it is blocked in the presence of spantide and by desensitization of the tissue with high doses of substance P. The transmitter responsible for the early NANC contraction has not been identified. Electrical field stimulation (EFS) applied to the tracheal smooth muscle during contraction induced by 5-HT in the presence of atropine and guanethidine elicited monophasic NANC relaxation. By contrast, NANC relaxation elicited in the smaller airways was biphasic, comprising an initial fast component followed by a second slow one. L-NAME selectively abolished the first component without affecting the second. VIP-antagonists or alpha-chymotrypsin considerably attenuated the amplitude of the L-NAME insensitive relaxation. These results indicate that at least two neurotransmitters, possibly NO or NO-containing compounds and VIP, are involved in i-NANC neurotransmission in the airway. In the urinary bladder a large, transient atropine resistant contraction occurs in response to pelvic nerve stimulation. This is blocked by alpha, beta methylene ATP suggesting that it is due to ATP. There is no evidence of inhibitory innervation. In the urethra contraction is completely blocked by atropine and guanethidine; a rapid NANC relaxation is abolished by drugs that block NO synthesis. Nerves containing peptides supply both urethra and bladder and may also be involved. These results suggest that all visceral smooth muscles may receive inhibitory NANC innervation involving NO. ATP produces contraction of the urinary bladder but relaxation of the digestive tract. The role of peptides is not yet clear but there is evidence that substance P may be an excitatory transmitter and VIP an inhibitory transmitter in many organs.

Adenosine Triphosphate↗
PubMed1995

Induction of 73-kDa and 90-kDa heat shock protein expression in HL60 cells during differentiation.

We investigated the expression of heat shock proteins HSP73 and HSP90 in human promyelocytic line HL60 during their differentiation induced by phorbor ester and all trans retinoic acid (ATRA). Polyclonal antibodies which had been raised against HSPs purified from bovine brains were used to detect human HSPs. Semiquantitation of HSPs was performed by immunoblotting. Induction of monocytoid and granulocytoid differentiation with phorbor ester and ATRA was accompanied by increased expression of HSP73 and HSP90 with distinct kinetics. Increased expression of both HSPs was confirmed by immunocytochemical studies. Our results suggest that HSP73 and HSP90 may be involved in differentiation of HL60 cells.

Animals↗
PubMed1995

Non-insulin-dependent diabetes mellitus complicated with idiopathic hypoparathyroidism.

We report a case of non-insulin-dependent diabetes mellitus (NIDDM) complicated with idiopathic hypoparathyroidism. A 74-year-old male was hospitalized because of diplopia. He was revealed to have NIDDM. The levels of serum Ca and intact-PTH were 6.3 mg/dl and < 5 pg/ml, respectively. Brain computed tomography revealed abnormal calcification in the cerebral basal ganglia and the cerebellum. After recovery from hypocalcemia, the endogenous insulin secretion was normalized. It is suggested that the pathogenesis of NIDDM in this patient may have been related to an insulin secretory defect as a result of hypocalcemia in addition to the hereditary risk.

Aged↗
PubMed1995

Induction of heat-shock proteins HSP73 and HSP90 in rat kidneys after ischemia.

We examined rat kidneys for serial expressions of two major heat-shock proteins (HSPs), HSP73 and HSP90, after 60 min of unilateral renal ischemia up to day 28. Immunohistochemical studies showed that HSP73 and HSP90 were rapidly induced in the cytoplasm of injured epithelial cells of the S3 segment of proximal tubules and were again induced in the cytoplasm of regenerative cells in this segment from day 3. In epithelial cells of the Henle's loops, HSP90 was also induced in the cytoplasm of both injured and regenerative cells, but HSP73 was not induced in this portion. Furthermore, a transient accumulation of HSP73 into the nucleus was observed in epithelial cells of papillary collecting ducts shortly after ischemia. Serial immunoblot analysis of isotonic buffer extractable fractions from ischemic kidneys revealed the induction of both HSP73 and HSP90 in the degenerative and regenerative phases: the maximal inductions in the two phases were at 3-6 and on days 5-7, respectively. These results demonstrate that HSP73 and HSP90 are induced in injured tubular epithelial cells with a regional heterogeneity during the degenerative and regenerative phases after renal ischemia and suggest that these HSPs are involved in the process of postischemic cellular recovery.

Animals↗
PubMed1995

A case report of colonic ileus due to eosinophilic nodular lesions caused by Gnathostoma doloresi infection.

Gnathostomiasis is primarily a disease of the skin characterized as creeping eruption or mobile erythema. However, larval Gnathostoma sometimes migrate into an unexpected site to elicit serious illness. Here we describe a case of colonic ileus caused by Gnathostoma doloresi. The patient was a 57-year-old man living in Miyazaki Prefecture, Japan, which is known as an area endemic for this parasite. One week after having eaten a few slices of the flesh of a snake (Agkistrodon halys), he developed severe abdominal pain. An abdominal radiograph revealed multiple gas-fluid levels with a distended bowel of an inverted U shape. A barium enema revealed a tumor in the ascending colon near the hepatic flexure that was surgically removed by simple colonic resection. An oblique section of a parasite surrounded by massive infiltration of eosinophils was found by postoperative histopathologic examination. The entire body of the advanced third-stage larva of G. doloresi was dissected from a specimen-embedded paraffin block.

Animals↗
PubMed1995

[Laser-TURP with a lateral firing fiber for contact irradiation].

We have operated 25 BPH patients with transurethral Nd-YAG laser ablation for prostate from June of 1993 till December of 1993. We used UltraLine fiber for contact laser irradiation of the prostate. This is a lateral firing quartz fiber with high density laser energy output, and so made it possible for us to vaporize prostatic tissue rapidly and deeply. We used 60 Watts of power for all cases. For the prostates larger than 50 cm3, limited resection after laser ablation allowed early relief of patients' symptoms. Two months after the treatment, average flow rate improved from 3.7 ml/sec to 7.8 ml/sec. Volume of residual urine decreased from 48.4 ml to 17.0 ml. Twenty-four percent decrease of prostatic volume was also recognized with transrectal sonography. Only 4 patients complained of transient urinary retention, although another 3 or 5 days catheter placement relieved their symptoms. Bleeding was negligible and the other postoperative complications were not recognized at all. Laser-TURP is a new treatment that is effective, less morbid and economical, compared with the ordinary TUR-P. So it will soon become an alternative method to electrocautery TUR-P.

Aged↗
PubMed1995

The influence of arm movements on a vertical jump.

The influence of arm lowering movements (ALM) on a vertical jump with all but the ankle joints immobilized was studied in five healthy volunteers. Subjects were instructed to rapidly lower both arms after takeoff when jumping from an initial position with the elbows flexed. They performed the jumps either with their hands empty or holding 4 kg dumbbells. ALM prolonged the time subjects were airborne, especially when holding the dumbbells. Protocol for the experiment required that subjects maintain maximum angular velocity of the ankle joint, vertical platform force, and electromyographic monitoring from the triceps surae muscle. Positive acceleration of the head increased in the ALM jumps, and became even more pronounced when the jumps were performed with dumbbells. This increase in head acceleration was inversely proportional to the downward acceleration of the hands. These results indicate that prolonging a vertical jump depends on ALM in the air.

Acceleration↗
PubMed1995

[Primary pulmonary alveolar proteinosis--clinical observation of 68 patients in Japan].

The clinical features of 68 Japanese patients (53 men and 15 women; mean age 44 years) with primary pulmonary alveolar proteinosis were reviewed. Pulmonary alveolar proteinosis was diagnosed from histologic findings after open lung biopsy (n = 7) or transbronchial lung biopsy (n = 61). Major symptoms were a dry cough (24.2%) and dyspnea or shortness of breath on exertion (51.5%), but one third of the patients were asymptomatic. Crackles were audible in 30% of the patients, but clubbing (6%) and cyanosis (4%) were rare. Ten patients had been occupationally exposed to dust. Slightly less than half (46%) of the patients first presented with symptoms, and the remainder (54%) first presented with abnormal pulmonary infiltrates seen on chest roentgenograms taken during general health examinations. Many patients had abnormally high levels of LDH and CEA in serum (62% and 63%, respectively). Restrictive pulmonary dysfunction (%VC < 80%) was seen in 31% of the patients, an abnormally low DLco (%DLco < 70%) was seen in 62%,m and hypoxemia (PaO2 < 80 mmHg) was seen in 67%. Arterial blood gas tension was closely correlated with the severity of disease in these patients. Chest roentgenograms usually showed bilateral symmetric alveolar infiltrates, mainly distributed from hilar areas toward the pleura, but on CT scans many of the shadows were mixed with alveolar and interstitial infiltrates of various extent along the pulmonary arteries and bronchi. There was no apparent relation between chest roentgenographic findings and chest CT findings in these patients. Neither the extension nor other characteristics of shadows in the chest roentgenograms and chest CT scans were closely related to symptoms, laboratory data, or pulmonary function in these patients. Symptoms were alleviated and chest roentgenographic findings improved in 82% of the 51 patients who underwent therapeutic bronchoalveolar lavage, and in 94% of the 17 patients who did not undergo that procedure. In patients who underwent therapeutic bronchoalveolar lavage and also in those who recovered spontaneously, both diffusing capacity and blood gas values improved significantly. When compared to the patients who did not undergo therapeutic bronchoalveolar lavage, significantly more of those who did undergo that procedure has initial PaO2 values below 60 mmHg, and fewer of them had values greater than 80 mmHg. Thus, a PaO2 below 60 mmHg may be an indication for therapeutic bronchoalveolar lavage in patients with this disease. During the follow-up period (mean 5 years, range 2 months to 23 years), four patients had pneumothorax and none died of pulmonary alveolar proteinosis.

Adult↗
PubMed1995

CT-pathology correlation of pulmonary tuberculosis.

Pulmonary tuberculosis is a chronic granulomatous disease characterized radiologically by nodules, air-space consolidation, propensity for cavitation, and calcification, and pathologically by caseating granulomas or pneumonia, and a great propensity for fibrosis and dystrophic calcification. Primary tuberculosis typically appears as air-space consolidation with hilar or mediastinal lymphadenitis. Postprimary tuberculosis appears most commonly as nodular and linear opacities at the lung apex. CT findings of early bronchogenic spread of postprimary tuberculosis are centrilobular 2- to 4-mm nodules or branching linear structure, 5- to 8-mm poorly defined nodules, lobular consolidation, cavities, and thickening of interlobular septa. Centrilobular nodules or branching linear lesions and poorly defined nodules on CT scan correspond to caseation materials filling the bronchioles, and centrilobular air-space consolidation with caseation necrosis. Poorly defined nodule or lobular consolidation usually consists of central caseation necrosis and peripheral nonspecific inflammation. Cavitation usually occurs at the centrilobular area and may progress to a larger coalescent cavity. With antituberculous therapy, resolution typically occurs from the peripheral portion of the poorly defined nodule or lobular consolidation and results in varying degrees of fibrous bands, bronchovascular distortion, emphysema, and bronchiectasis. Miliary tuberculosis appears as well-defined randomly distributed nodules on CT scan that correspond with nodules consisting of central caseation necrosis and peripheral epitheloid and fibrous tissue. Analysis of CT images on the basis of pathologic correlation is helpful in understanding the morphology of pulmonary tuberculosis.

Adult↗
PubMed1995

Hamster alpha 1B-adrenergic receptor directly activates Gs in the transfected Chinese hamster ovary cells.

A prototypic Ca(2+)-mobilizing hormone receptor, alpha 1-adrenergic receptor (alpha 1AR), stimulates cAMP accumulation. The mechanism underlying this phenomenon was previously suggested to be secondary to phosphatidylinositol hydrolysis-protein kinase C activation in some cells. We transfected Chinese hamster ovary (CHO)-K1 cells with hamster alpha(1B)AR cDNA and isolated cells stably expressing alpha(1B)AR (CHO alpha 1B cells). We investigated the molecular mechanism underlying the alpha 1AR-mediated cAMP production in the CHO alpha 1B cells. Norepinephrine (NE) stimulated intracellular calcium mobilization and cAMP production through alpha(1B)AR. Pretreatment with a phospholipase C inhibitor, U-73,122 (10 microM), abolished the NE-induced intracellular calcium response, whereas it did not affect the NE-stimulated cAMP production. Treatment with various agents (protein kinase C inhibitors, calcium ionophore, cyclo-oxygenase inhibitor, or pertussis toxin) had little effect on the NE-induced cAMP production. The parent CHO and CHO alpha 1B cells contained similar amounts of Gs alpha (42 and 45 kDa, respectively), as detected with immunoblot analysis, and exhibited similar extents of cAMP synthesis with cholera toxin and forskolin. Adenylyl cyclase activity in the CHO alpha 1B cell membranes was also enhanced by NE. Furthermore, incubation of CHO alpha 1B cell membranes with antiserum directed against the carboxyl-terminal portion of Gs alpha inhibited the NE-stimulated adenylyl cyclase activity. Taken together, the results indicate that the alpha(1B)AR-mediated cAMP synthesis in CHO alpha 1B cells reflects direct stimulation of Gs-adenylyl cyclase. Therefore, the alpha 1AR-stimulated cAMP production observed in some native tissues may involve the multiple mechanisms of the direct activation of Gs-adenylyl cyclase and a secondary effect through activation of phosphatidylinositol hydrolysis.

Adenylate Cyclase Toxin↗
PubMed1995

[Chemohyperthermic peritoneal perfusion and subtotal peritonectomy for peritonitis carcinomatosa in gastroenteric cancer].

A new operative procedure, called subtotal peritonectomy (SP), in combination with chemohyperthermic peritoneal perfusion, was developed for the treatment of peritonitis carcinomatosa in gastrointestinal cancer. SP includes resection of primary lesion, colon, small bowel, spleen, and gall bladder and parietal peritonectomy. Six patients with gastric cancer and two patients with colon cancer underwent these procedures. A great deal of discharge from the peritoneal cavity, an increase in systemic vascular resistance index, and a decrease in central venous pressure represented much decrease in circulatory volume on days 1 to 2 postoperatively. This state improved at 3 to 4 days after operation. Histopathological study revealed multiple peritoneal seedings with negative surgical margins in all patients. There were no related deaths though bleeding, perforation, and abscess occurred in two patients each. One patient died of peritoneal recurrence after one year, but the other have survived.

Adult↗