Biomedical subjects
Publications and source records attributed to M Yagi.
In a screening series of bioactive components in edible and medicinal plants, we found that Calumbae Radix (Colombo root, 1% powdered feed, for 5 d) and its component, columbin (20-40 mg/kg/d, for 5 d, orally), shortened the sleeping time induced by a urethane and alpha-chloralose mixture and prolonged the sleeping time induced by hexobarbital in mice.
This study was designed to compare the renal effects of atrial (A-type) natriuretic peptide (ANP) on control (saline-injected) rats and rats with non-oliguric acute renal failure induced by cisplatin. The results obtained here are summarized as follows: (1) In the metabolic cage study, cisplatin-treated rats showed increases in blood urea nitrogen and serum creatinine while creatinine clearance decreased to the lowest levels on day 4. A transient increase in urinary protein was observed at day 4. (2) ANP infusion significantly increased urine flow rate (UFR), creatinine clearance (CCr), fractional excretion rates of sodium (FENa) and chloride (FECl), and urinary phosphorus and magnesium (Mg) excretions in a dose-dependent manner without affecting renal plasma flow and fractional excretion rates of potassium and urea in cisplatin-treated rats. (3) Renal effects of ANP on UFR, CCr, FENa, FECl and excretion of Mg were more pronounced in cisplatin-treated rats compared to control rats although markedly blunted responses to ANP have been reported in nephrotic patients and nephrotic animals induced by adriamycin and aminonucleoside. (4) Histological examination showed extensive necrosis of the S3 segment of the proximal tubule located in the outer stripe of the outer medulla with minimal glomerular abnormalities in the kidney of cisplatin-treated rats. In conclusion, the main mechanism of the increased renal responses to ANP is considered to be due to an increased delivery of sodium, fluid and ANP itself to the inner medullary collecting duct which is the major renal site of action of ANP under the condition of acute proximal tubular necrosis by cisplatin.
To evaluate intestinal motility after 80% massive distal small bowel resection (MSBR), we continuously monitored interdigestive and postprandial bowel motility using bipolar electrodes and/or contractile strain gage force transducers in conscious beagle dogs before, and at 0-4 weeks and 8-13 months after the surgery. Fasting duodenal migrating myoelectric (or motor) complexes (MMCs) occurred at longer intervals in the short-term after 80% MSBR than in controls, and were simulated in long-term that in controls. MMCs arising from the duodenum were often migrated to the proximal jejunum, the jejunum above the anastomosis, and to the terminal ileum beyond the anastomosis. The velocity of duodenal MMC propagation was slowed in every intestinal segment in the short-term, and had not recovered even long after the operation. The duration of the postprandial period without duodenal MMCs was prolonged significantly in the short-term, and still remained longer in the long-term than in controls. These findings suggest that changes in gut motility after MSBR tend to compensate for the shorter intestine and maintain small bowel absorption early postoperatively, and adaptations of motility would occur over the long-term to increased intestinal absorption.
Long-term survivors (> or = 5 years) of pancreatoduodenal carcinoma were evaluated. The absence of retropancreatic invasion seemed to be an important factor for long-term survival in carcinoma of the pancreatic head, carcinoma of the intrapancretic bile duct confined within the bile duct wall, and stage II papilla of Vater carcinoma. The mode of infiltration was INF alpha or INF beta, with a low infiltration tendency. Lymph node metastasis, when present, was confined to the pancreatic head. It is noteworthy that two of the patients with intrapancreatic bile duct cancer had perineural infiltration to the pancreatic head plexus. In patients treated by extended resection, postoperative malnutrition and diarrhea was severe, indicating the importance of long-term nutritional management.
It has been suggested that the number of argyrophilic nucleolar organizer regions (AgNORs) correlates with cellular activity and the aggressiveness of malignancy. The mean number of AgNORs per nucleus may, therefore, be a prognostic factor for hepatocellular carcinoma (HCC). The purpose of this study was to evaluate the prognostic significance of the number of AgNORs in HCC. The silver-staining technique was applied to surgically resected specimens to indicate AgNORs. Eighty-nine of the specimens were of HCC, 23 were of normal liver adjacent to HCC, and 32 were of cirrhotic liver adjacent to HCC. The number of AgNORs of HCC (mean +/- SD, 3.26 +/- 1.23) was significantly higher than those of normal liver (1.37 +/- 0.13) and cirrhotic liver (1.49 +/- 0.14). The number of AgNORs was significantly correlated with serum alpha-fetoprotein level, tumor size, portal vein invasion, and Edmondson-Steiner histological grade. In patients undergoing curative resection, the survival rate of those with a high number (> 3.04) of AgNORs was significantly worse than that of those with a low number (< or = 3.04) of AgNORs. Multivariate analysis showed that the number of AgNORs was a significant prognostic indicator in patients without portal vein invasion, and portal vein invasion was the only significant variable when all patients undergoing curative resection were assessed together. The results of this study suggest that the number of AgNORs is useful as an indicator of the grade of malignancy and as a predictor of the prognosis of patients with HCC who do not have portal vein involvement.
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Human platelet glycoprotein Ib beta (GPIb beta) (M(r) 22,000) is part of the GPIb-V-IX system that constitutes the receptor for von Willebrand factor and mediates platelet adhesion in the arterial circulation. The four members of the receptor (GPs Ib alpha, Ib beta, V, and IX) share structural and functional features. Individually, GPIb beta contributes to surface expression of the receptor and participates in transmembrane signaling through phosphorylation of its intracellular domain. To define the structure of the GPIb beta gene, a cosmid clone from a human genomic library was analyzed. The transcriptional start site was located by both primer extension and the "anchored" polymerase chain reaction. Similar to the genes for Ib alpha, V, and IX, the Ib beta gene is compact with a single 274-base intron inserted into the 5' end of the open reading frame. The 5'-flanking region of the gene contains both GATA and ets sites that are also found in the 5' promoter regions of other described megakaryocyte/platelet genes. The GPIb beta gene was localized to chromosome 22q11.2 by fluorescence in situ hybridization. The GPIb beta gene has a simple structure, similar to that of other described megakaryocyte/platelet genes, including those of the GPIb-V-IX system.
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OBJECTIVE: To study the pathophysiological features of acute low-tone sensorineural hearing loss without vertigo (ALHL) and its correlation with Meniere's disease. DESIGN: Retrospective review of medical charts of patients with ALHL. SETTING: University hospital clinic. PARTICIPANTS: Eighty consecutive patients with ALHL, including 45 patients whose conditions were followed up for more than 3 years (average, 5 years 2 months; range, 3 years 3 months to 8 years). OUTCOME MEASURES: Age and sex distributions and results of audiological and neuro-otological tests, initial outcome, recurrence rates, and differences between patients with and without recurrence. RESULTS: About 75% (62/80) of the patients were between the ages of 30 and 60 years and the female-male ratio was 2:6. Positive glycerol test results were found in 74% (26/35) of patients and abnormally increased negative summating potential/action potential ratio in 63% (50/80). No abnormalities were found on neuro-otological tests. Hearing loss improved within 3 months in 84% (67/80) of the patients. Of 45 patients followed up for more than 3 years, 28 (62%) showed no evidence of recurrence, 12 (27%) developed cochlear Meniere's disease, and five (11%) developed classic Meniere's disease. No significant differences were found at the first examination between patients with and without recurrence. CONCLUSIONS: These results suggest that ALHL may be caused by endolymphatic hydrops confined to the cochlea and that ALHL does not always lead to cochlear or classic Meniere's disease.
We report herein the unusual case of a 10-year-old girl in whom a neoplasm developed in the head of the pancreas. Complete extirpation of the tumor was performed, which was histologically classified as a "solid and cystic tumor of the pancreas." Postoperative DNA analysis revealed a diploid pattern. The patient remains well with no sign of tumor recurrence 2 years after her operation. Thus, complete tumor extirpation without pancreatectomy is recommended for pediatric patients when there is no direct invasion to the adjacent organs or distant tumor metastasis.
BACKGROUND/AIMS: Prognostic analysis on hepatocellular carcinoma (HCC) in patients undergoing hepatectomy is necessary to determine the clinical value of hepatectomy on prognosis. METHODS: Survival and disease-free survival were analyzed in 104 HCC patients undergoing hepatectomy using clinicopathologic factors by univariate and multivariate analyses. The value of the International Union Against Cancer (UICC) TNM classification on prognosis was assessed in the patients. RESULTS: In multivariate analysis, portal vein invasion was the most influential factor. The difference between stage 1 and 2 or stage 3 and 4A using UICC's TNM classification was not significant with respect to survival or disease-free survival. The UICC's classification was modified as follows; stage 1, solitary tumor without vascular invasion; stage 2, solitary or multiple tumor(s) involving adjacent to vessel branch; stage 3, tumor(s) involving major vessel branch or with regional lymph nodal metastasis; and stage 4, tumor(s) with distant metastasis. The differences between each stage in the modified classification were significant with respect to disease-free survival. CONCLUSIONS: The UICC's TNM classification was not of prognostic significance. Further studies on survival in patients with HCC are necessary to evaluate the value of the UICC's TNM classification; some modification may be necessary.
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)
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)
A study was designed to determine whether oesophageal carcinomas can be induced through reflux of duodenal contents. Male Wistar rats weighing 230-250 g were divided into three groups according to the surgical procedure performed: (1) the duodenal contents were directed into the forestomach through a stoma (duodeno-forestomach reflux); (2) the duodenal contents were regurgitated into the forestomach through the glandular stomach (duodeno-glandular-forestomach reflux); and (3) a sham operation was performed as a control. Animals were fed standard CRF-1 solid food and tap water that was not exposed to carcinogens and were sacrificed 50 weeks post-operatively. While no neoplasia was observed in any of the 32 control rats, 4/11 (36%) with duodeno-forestomach reflux and 3/18 (17%) animals with duodeno-glandular-forestomach reflux developed carcinomas in the lower oesophagus and forestomach. The incidence in each group was significantly higher than in the controls (P < 0.01 and P < 0.05 respectively). Six of the seven lesions consisted of squamous cell carcinomas, and one was a mucinous adenocarcinoma. Oesophageal columnar epithelial metaplasia was observed in two (18%) of the animals with duodeno-forestomach reflux. Carcinomas were always surrounded by chronic inflammatory changes, including regenerative thickening, basal cell hyperplasia and dysplasia. Additional well-differentiated adenocarcinomas were observed in the prepyloric antrum of 6/18 (33%) animals with duodeno-glandular-forestomach reflux. These findings indicate that chronic reflux of duodenal contents may cause oesophageal carcinoma.
The Research Committee of the Ministry of Health and Welfare in Japan has defined hearing loss of unknown etiology with fairly high-speed progression as idiopathic bilateral sensorineural hearing loss (IBSH). Its diagnostic criteria consist of the following: that it is (1) progressive, (2) with bilateral involvement, and (3) of unknown etiology. In this study, we evaluated the clinical course in 20 cases of IBSH. Many cases of IBSH finally showed symmetrical profound sensorineural hearing loss. The clinical course of IBSH consisted of various combinations of the following four states: (1) fixed hearing, (2) rapid progression, (3) pathological slow progression and (4) physiological slow progression.
The DNA strand-breaking activities of 9 quinolones, widely used as antimicrobial agents and suspected to induce photo-dermatological disorders in humans, were examined under irradiation using standard domestic fluorescent lamps. Two quinolones, tosufloxacin and enoxacin, converted the supercoiled covalently closed circular plasmid DNA to the open circular form under visible light irradiation. The maximum of photodynamic single strand-breaking activity for tosufloxacin was found to be 12% at 50 microM and that of enoxacin was 33% at a concentration of 2 mM. The DNA strand-breaking activities of photoirradiated tosufloxacin and enoxacin were markedly inhibited by NaN3 but only partially by D-mannitol, superoxide dismutase (SOD) and catalase did not inhibit these activities. These results suggest that some quinolone antimicrobial agents can be activated by visible light and induce phototoxic DNA damage in various organisms. We should carefully investigate such phototoxic activities during the development of new quinolones to avoid producing phototoxic disorders in man.