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Biomedical subjects

Y Ohsawa

Publications and source records attributed to Y Ohsawa.

At least 55 records · Page 3Linked to original sources
PubMed1998

Familial amyotrophic lateral sclerosis with widespread vacuolation and hyaline inclusions.

This report presents a familial amyotrophic lateral sclerosis (FALS) patient with widespread vacuoles and hyaline inclusions strongly immunostained with the anti-superoxide dismutase (SOD1) antibody. The overall pathologic similarity between our non-SOD1-linked FALS patient and transgenic mice expressing a mutated human SOD1 gene suggests that common pathogenetic mechanisms other than an SOD1 mutation exist in the development of these diseases.

Aged↗
PubMed1998

An ultrastructural and immunohistochemical study of PC12 cells during apoptosis induced by serum deprivation with special reference to autophagy and lysosomal cathepsins.

In addition to the caspase family of proteinases, cathepsin D, a lysosomal aspartic proteinase, has been suggested to act as a proapoptotic mediator in mammalian cells. To further understand the roles of cathepsins B and D in apoptosis of the cells, we examined the precise alteration processes of ultrastructures and immunoreactivity for these enzymes in PC12 cells cultured under serum deprivation. Laser scanning microscopy showed immunoreactivity for cathepsins B and D to be finely distributed in the cytoplasm of PC12 cells at the onset of culture under serum deprivation. At 3 h after the onset of culture, the immunoreactivity for cathepsin B slightly decreased in the cells, while immunodeposits for cathepsin D in the cells became more intense and larger in size than those at 0 h. Positive staining for TUNEL in nuclei of the cells appeared at 6 h, though fewer in number. Corresponding to the increase in the number of TUNEL-positive cells at 12 h and 24 h, the immunoreactivity for cathepsin B was drastically diminished in the cells, whereas that for cathepsin D was significantly augmented, especially in TUNEL-positive cells. Electron microscopically, autophagic vacuoles/autolysosomes appeared in the cytoplasm of the cells 3 h after the onset of culture. A distinct nuclear change showing relatively condensed chromatin first appeared in the peripheral part of the nuclei at 6 h. The number of PC12 cells having nuclei with chromatin condensation increased especially at 24 h, while these cells showed shrinkage of both their cytoplasm and nuclei. Dense bodies and autophagic vacuoles with limiting membranes were seen in these cells. These results showing the occurrence of autophagy and imbalance of protein amounts between cathepsins B and D during apoptosis may argue for our hypothesis that these enzymes are, in part, involved in the cell death cascade for PC12 cells following serum deprivation.

Animals↗
PubMed1998

Immunocytochemical localization of chromogranin A and secretogranin II in female rat gonadotropes.

Ultrastructures of pituitary gonadotropes are known to show a prominent sex-related difference: typical male rat gonadotropes contain both large- and small-sized granules, whereas typical female rat gonadotropes appear to exhibit uniformly small-sized granules. Our preceding studies have demonstrated that two representative granins, chromogranin A (CgA) and secretogranin II (SgII), are separately localized to each type of granule in male rat gonadotropes. To clarify whether or not there is a certain relationship between granin proteins and characteristic features of secretory granules in female rat gonadotropes, we examined the expression levels and immunocytochemical localizations of CgA and SgII in the cells. Northern blot and immunoblot analyses demonstrated that both CgA and SgII were synthesized and stored in the female pituitary, although the amount of CgA was much lower in the female than that in the male pituitary. Immunocytochemical observations clarified that gonadotropes in the female pituitary possessed intermediate secretory granules containing both CgA and SgII, in addition to solely CgA-positive and SgII-positive ones. However, secretory granules containing CgA in the female gonadotropes were much smaller in size and appeared less frequently than those in the male cells, whereas no sexual difference was discerned in SgII-positive granules. Moreover, the size and appearance of CgA-positive secretory granules varied depending on stages of the estrous cycle. These findings suggest that the size and appearance of secretory granules containing CgA are closely associated with the expression and storage levels of CgA in the pituitary.

Animals↗
PubMed1997

Immunocytochemical localization of lysosomal cysteine and aspartic proteinases, and ubiquitin in rat epidermis.

To analyze the degradation system in epidermal cells during their generation, differentiation, and cell death, immunocytochemical localization of lysosomal cysteine and aspartic proteinases, an endogenous cysteine proteinase inhibitor, cystatin beta, and ubiquitin were examined using rat sole skin. By confocal laser microscopy, granular immunodeposits for lysosomal proteinases were well demonstrated in epidermal cells; immunoreactivity for cathepsins B and C was prominent in the lower spinous and basal layers, while that for cathepsins L and D was intense in the upper spinous and granular layers, although immunoreactivity for cathepsin D was also detected in the lower epidermal layers. Immunoreactivity for cathepsin H was weakly detected only in the spinous layer, where there were some intensely immunopositive cells with processes which were also immunopositive for S-100 alpha, indicating that these cells were Langerhans cells. Diffuse immunoreactivity for cystatin beta was intense in the spinous and granular layers and weak in the basal layer. In addition, we also examined the localization of ubiquitin, which is a signal peptide for cytosolic proteolysis; clear-cut granular immunodeposits for ubiquitin were detected in spinous and granular cells, and some were co-localized with cathepsin B immunoreactivity. In the basal layer, mitotic cells were strongly immunopositive for ubiquitin. These results suggest that cysteine and aspartic proteinases are involved in the lysosomal system of the epidermis, showing different distributions in the epidermal layers depending on the enzymes examined. Moreover, ubiquitin may be associated with the cell cycle-dependent degradation in basal cells while it also participates in the non-lysosomal proteolysis and probably, lysosomal proteolysis in the spinous and granular cells.

Animals↗
PubMed1996

Phasic motor activity reduction occurring with horizontal rapid eye movements during REM sleep is disturbed in infantile spasms.

Single polysomnography was performed before treatment in 17 patients with infantile spasms (IS) (13 with a cryptogenic type and 4 with a symptomatic one). Their sleep components during rapid eye movement (REM) sleep were compared with those in 22 age-matched controls. The tonic muscle atonia during REM sleep was observed in all IS patients as in controls. The amount of REM sleep in IS patients was significantly lower, while the incidences of gross movements, phasic chin muscle activity, and bursts of horizontal rapid eye movements were identical with those in controls. The phasic inhibition index (PII), i.e., the rate of simultaneous occurrence of phasic chin muscle activity and bursts of horizontal rapid eye movements, was significantly higher in IS than in controls. The PII value was the only parameter that reflected our patients' prognosis among the obtained REM sleep parameters. We presume that the elevated PII in IS reflects the weakness of the phasic motor activity reduction occurring with horizontal rapid eye movements, and attribute this disturbance to a functional instability of the rostral pontine tegmentum. We propose that PII is a useful parameter for assessing the prognosis of IS. Considering the neural basis for elevated PII in IS, this index is expected to provide a clue for explaining the pathophysiology of IS.

Case-Control Studies↗
PubMed1996

Lysosomal cysteine and aspartic proteinases and ubiquitin in rat and human urinary bladder epithelium.

To examine localization of cysteine and aspartic proteinases, and ubiquitin in rat and human urinary bladders, immunocytochemistry was applied to the tissues. In semi-thin sections, immunoreactivity for cathepsins B and D was densely localized throughout epithelial layers of rats and humans, while that for cathepsins H and L was mainly localized in rat superficial and human intermediate cells. Immunoreactivity for cathepsin C was relatively high in rat and human epithelia, especially in humans. Immunoreactivity for ubiquitin was detected in rat and human epithelial cells. By electron microscopy, vesicular or heterogeneously dense lysosomes labeled with immunogold particles indicating cathepsin B were seen in rat and human epithelial cells; particularly, they often appeared near fusiform vesicles in rat superficial cells and in human intermediate and superficial cells. By double immunostaining, lysosomes with or without vesicular structures were co-labeled with immunogold particles showing both cathepsin B and ubiquitin. The results suggest that cathepsins B, C, H, and L, and cathepsin D are involved in the lysosomal system of rat and human bladder epithelia. Moreover, considering that ubiquitin is a cofactor in the soluble ATP-dependent proteolysis, the results may also indicate that epithelial cells actively form autophagolysosomes.

Animals↗
PubMed1996

[Hemilateral hydrothorax and atelectasis during laparoscopic Nissen fundoplication].

A 57-year-old woman, weighing 75 kg, with gastroesophageal sliding hernia, received laparoscopic Nissen fundoplication under general anesthesia. Although artificial ventilation was carried out uneventfully when the surgery started, sudden decreases in SpO2 and thoraco-pulmonary compliance were noted after insufflation of CO2. Breath sound was not audible on the left lung. We suspected that inadvertent pneumothorax was produced, but chest X-ray and transesophageal echocardiography at the end of surgery revealed the presence of left hemilateral hydrothorax with pulmonary atelectasis. She was ventilated artificially and given diuretics and albumin solution for 3-days before extubation. We speculated on two reasons for the event: a possibility of perforation of the diaphragm manipulated by surgeons, and that of transition of fluid used for irrigation just below the diaphragm. Pulmonary atelectasis could be induced with hemilateral lung ventilation because cephalad shifting of the diaphragm might follow the intraperitoneal insufflation. We conclude that laparoscopic surgery with insufflation of gas and irrigation with fluid requires careful attention if the laparoscopic surgery is sustained with insufflation and irrigation.

Anesthesia, General↗
PubMed1994

Analysis of a new fluoroquinolone derivative (Q-35) in human scalp hair as an index of drug exposure and as a time marker in hair.

Scalp hair samples were obtained every month for three months after administration from healthy male volunteers who participated in the phase I study of a new antimicrobial fluoroquinolone derivative (Q-35). Hairs were cut into 1 cm long pieces successively from the scalp end. Corresponding pieces of 5 hair strands were dissolved in 1 M NaOH and assessed for Q-35 by HPLC. The drug was detectable in the hairs of all subjects taking either a single (400 mg, n = 6) or repeated oral doses of Q-35 (400 mg/day for 6.5 days, total 2600 mg, n = 6). The hair portions containing the drug were shown in most subjects to move outwards along the hair shafts month by month in proportion to the hair growth rate of about 1 cm/month. Q-35 (600 mg/day) was also given to 6 healthy male volunteers for 6.5 days (total 3900 mg) and hair samples were obtained 1 and 3 months after administration. When Q-35 was analyzed along a single hair shaft, the drug was detectable only in 1-2 consecutive 1 cm long pieces, which were also shown to move outwards along the hair shaft with time. A detailed analysis revealed that the drug was contained only in 2-4 consecutive 2.5 mm long pieces of a single hair collected after 3 months, showing that there was no significant axial diffusion of the drug along the hair shaft with time.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Resulting long-term intestinal motility in dogs following construction of a reversed jejunal segment after extensive small bowel resection.

To evaluate the long-term function and effective motility of a reversed jejunal segment after extensive small bowel resection, the authors continuously measured postoperative bowel motility during interdigestive and postprandial periods in conscious dogs 6 to 10 months after surgery. The long-term findings were compared with previously reported short-term results measured 2 to 4 weeks after the operation. In the long-term follow-up dogs with a 20-cm reversed jejunal segment constructed after extensive (75% to 80%) small bowel resection, the fasting duodenal migrating myoelectric (or motor) complex (MMC) was often interrupted in the jejunum above the reversed segment, and did not migrate smoothly to the reversed segment or terminal ileum. The MMCs arising from the duodenum predominantly propagated to the ileum through the inherent anatomic continuity of the bowel. In addition, brief small discordant contractions were frequent in the reversed segment and the jejunum, above the proximal anastomosis. These findings are similar to those of the MMC propagation pattern noted 2 to 4 weeks after surgery. However, the postprandial duration without duodenal MMC activity was significantly shorter in the dogs with long-term follow-up than in those with short-term follow-up (both were longer than in control dogs). Marked dilatation of the jejunum and reversed jejunal segment was noted across the proximal anastomosis. These results suggest that the transit time and passage of intestinal contents can be delayed and stagnated for at least 10 months after extensive small bowel resection with a 20-cm reversed jejunal segment.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗
PubMed1994

Long-term results after nonshunt operations for esophageal varices in children.

The clinical results of nonshunt operations for esophageal varices in 15 children were evaluated. The varices were caused by congenital extrahepatic portal obstruction (EHPO) in 10, liver cirrhosis or fibrosis (C/F) in 3, and idiopathic portal hypertension (IPH) in 2. The operative procedures were transthoracic esophageal transection with paraesophageal devascularization (TR) for 2 EHPO patients under 5 years of age, TR combined with splenectomy and paragastric devascularization (Sugiura procedure) for 11 (8 EHPO, 3 C/F), and splenectomy with devascularization (SP) or splenectomy for the 2 IPH patients. In the EHPO patient under 5 years of age, TR is associated with a likelihood of gastric or esophageal hemorrhage resulting from hypersplenism, gastric congestion, or persistent distal esophageal varices, which can be treated with partial splenic arterial embolization (PSE), endosclerotherapy, or an additional abdominal procedure. The Sugiura procedure has provided satisfactory long-term results, without rebleeding from esophageal varices, in patients with EHPO and C/F for 1 to 20 years. But EHPO patients who undergo the Sugiura procedure before age 6 can have gastric hemorrhage, because of mucosal congestion, for more than 10 years after the procedure, and selective gastric arterial embolization (GAE) might be necessary. In some EHPO patients, especially young ones who have variceal bleeding, a significant increase in hepatopetal portal flow may not develop, but hepatofugal natural shunts may progress. Therefore we recommend direct operative procedures, ie, TR for patients < or = 6 years of age and a one- or two-stage Sugiura procedure for those over 7 years old.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Sensitive method for determination of nicorandil in human plasma by reversed-phase high-performance liquid chromatography with ultraviolet detection.

A sensitive method for the determination of nicorandil, an anti-anginal drug, has been developed. The method involves solid-phase extraction of the drug and an internal standard using a Bond-Elut PH extraction column, liquid-liquid extraction with methyl acetate and dichloromethane, and reversed-phase high-performance liquid chromatography on a mu Bondapak C18 column with an ultraviolet detector. The limit of determination in plasma was 3 ng/ml and the intra-day coefficient of variation (n = 7) was less than 10%.

Anti-Arrhythmia Agents↗
PubMed1993

Lysosomal cysteine and aspartic proteinases, acid phosphatase, and an endogenous cysteine proteinase inhibitor, cystatin-beta, in rat osteoclasts.

To understand the bone resorption and lysosomal proteinases in osteoclasts, we examined by immunohistochemistry the localization of lysosomal cysteine and aspartic proteinases, acid phosphatase, and cystatin-beta in the rat tibial bone. Immunoreactivity for cathepsins B, C, H, and L, cathepsin D, acid phosphatase, and cystatin-beta was demonstrated in various cells of the bone tissue; in particular, large multinucleated osteoclasts attached to the bone surface and chondroclasts in the proximal growth plate. These cells showed intense immunoreactivity for these lysosomal enzymes and cystatin-beta. Bone surface-lining osteoblasts displayed distinct immunoreactivity for cathepsins B, C, D, H, and acid phosphatase, while osteocytes often exhibited that for cathepsins D, H and acid phosphatase. Chondrocytes in the growth plate demonstrated intense immunoreactivity for cathepsins B, D, and acid phosphatase. Immunoreactivity for cystatin-beta was detected in osteoclasts and chondroclasts only. Large, round multinucleated cells free from the bone surface exhibited weak, faint, or no immunoreactivity for the lysosomal enzymes and cystatin-beta. These results suggest that lysosomal cysteine and aspartic proteinases may play a role in the degradation of organic constituents of the bone matrix. Moreover, cystatin-beta can serve as an excellent marker protein for osteoclasts.

Acid Phosphatase↗
PubMed1993

[Relationship between abdominal fat distribution assessed by computed tomography and serum lipids in the elderly].

A nutritional assessment is necessary to evaluate the pathophysiological state of patients, and serum lipids are one of the factors which must be evaluated. Body fat distribution is considered to be associated with cardiac diseases, metabolic diseases and hypertension. In this study, we performed quantitative measurements of fat distribution by X-ray computed tomography (CT) in 31 elderly outpatients. Thirteen males (mean age 74.8 years) and 18 females (mean age 75.4 years) were examined by abdominal CT. All subjects had body mass indices within the normal range and did not have malignant disease, hyperlipidemia, liver dysfunction or diabetes mellitus. CT scans were carried out at the level of the middle abdomen; these scan slices included intraabdominal fat which consisted of omental, retroperitoneal and perirenal adipose tissues. Subcutaneous fat areas and intraabdominal fat areas were measured from six 10-mm-thick slice films using a 2-dimensional computerized calculator. The relationship between serum lipids and fat distribution was also examined. The ratio of intraabdominal adipose tissue area to subcutaneous adipose tissue area (V/S) was higher in males than in females. V/S correlated positively with serum triacylglycerol and correlated negatively with serum HDL-Ch. These results suggest that the measurement of body fat distribution is important to evaluate lipid metabolism and nutritional states in the elderly.

Adipose Tissue↗
PubMed1992

An experience of cell sorting using samples isolated from paraffin-embedded tissue of neuroblastoma.

Flow cytometric DNA content analyses were performed on samples from 72 patients with neuroblastoma. Nuclear suspensions obtained from paraffin-embedded samples were prepared using the method described by Schutte et al. Determination of DNA ploidy was possible in 62 out of 72 patients. DNA diploidy was detected in 23 (37.1%) and DNA aneuploidy was found in 39 (62.9%) of these 62 patients. Cell sorting was performed on two peak areas of the DNA histogram of samples with aneuploidy. The sorted cells of the first peak area were composed of small round cells and were considered to be normal lymphocytes. The sorted cells of the second peak area were composed of relatively large cells with obvious nucleoli and were considered to be neuroblastoma cells. Thus, two cell components could be distinguished by cell sorting. It is concluded that cell sorting may be of benefit in giving detailed information about DNA histograms, even in samples obtained from paraffin-embedded tissue.

Cell Separation↗
PubMed1992

Intestinal myoelectric activity and contractile motility in dogs with a reversed jejunal segment after extensive small bowel resection.

To evaluate the functioning and effectiveness of a reversed jejunal segment after extensive small bowel resection, we continuously measured the postoperative bowel motility (using bipolar electrodes and/or contractile strain gage force transducers) in interdigestive and postprandial conscious dogs at 2 to 5 weeks after surgery. The fasting duodenal migrating myoelectric (or motor) complex (MMC) occurred at markedly longer intervals in dogs with a 20-cm reversed jejunal segment created after 75% to 80% extensive small bowel resection (group 3) than in dogs that received extensive resection alone (group 2) or dogs that underwent construction of a reversed jejunal segment without bowel resection (group 1). The MMC arising from the duodenum was often interrupted at the jejunum above the proximal anastomosis and did not migrate smoothly to the reversed segment or terminal ileum in group 3. In addition, brief small discordant contractions were frequent in the reversed segment and the jejunum above the proximal anastomosis in group 3. The duration of the postprandial period without duodenal MMC activity was significantly prolonged in groups 2 and 3. These results suggest that the transit time and passage of intestinal contents were delayed and that the periodical MMC was disturbed in group 3. The delay of transit time was due to prolongation of the interval between duodenal MMCs, the interruption of MMC propagation at the jejunum above the proximal anastomosis, the dominance of MMCs that followed the inherent anatomical continuity of the bowel, and discordant movements across the proximal anastomosis. Functional obstruction could be a potential problem in a 20-cm reversed jejunal segment inserted after extensive small bowel resection.

Anastomosis, Surgical↗
PubMed1991

Flow cytometric DNA analysis of neuroblastoma: prognostic significance of DNA ploidy in unfavorable group.

Flow cytometric DNA content analyses were performed on samples of 54 patients with neuroblastoma. DNA aneuploidy was detected in 55.6% of the 54 patients. A high incidence of DNA aneuploidy was observed in patients with prognostically favorable variables such as age (less than 1 year), clinical stage (I, II, or IVs), and primary site (extraadrenal sites). DNA aneuploidy was predominant in surviving patients, even in those with unfavorable variables. In patients 1 year old or more, the survival rate among those with DNA aneuploidy was 58.8% compared with 28.6% in patients with diploidy. Likewise, in patients with advanced stage (III or IV) neuroblastoma, the survival rate among those with DNA aneuploidy was 63.2% compared with 30.4% in patients with DNA diploidy. It is concluded that DNA content analysis is of value in predicting the prognosis of patients with neuroblastoma.

Adrenal Gland Neoplasms↗
PubMed1991

Effect of protein deprivation on insulin-like growth factor-binding proteins in rats.

The effect of protein deprivation on plasma concentration of insulin-like growth factor-binding proteins (IGFBP) was studied in rats. A significant decrease in the concentration of IGFBP of molecular weight (mass) approximately 40 kDa was observed in protein-deprived rats. There was no prominent effect of protein deprivation on the concentration of IGFBP with molecular weights of about 30 kDa or 22-24 kDa. The binding capacity to plasma IGFBP of exogenously-added 125I-labelled insulin-like growth factor-1 (125I-IGF-1) was also studied. IGFBP of molecular weight about 30 and 22-24 kDa (the native form of this protein is presumed to be 29 kDa) in protein-deprived rat plasma bound more 125I-IGF-1 than those in protein-fed rat plasma. This suggested that these IGFBP in protein-deprived rat plasma are relatively unsaturated by endogenous IGF-1. The response of IGFBP to protein deprivation which was elucidated in the present investigations add further evidence to our previous assumption that IGFBP play an important role in protein nutrition.

Animals↗