Biomedical subjects

H Naito

Publications and source records attributed to H Naito.

At least 73 records · Page 4Linked to original sources

PubMed1999

Management of urinary complications in Crohn's disease.

Among the 127 patients who underwent surgical treatment for Crohn's disease at Tohoku University Hospital, urinary complications were noted in 13 patients (10.2%), including urolithiasis in 6 patients (4.7%), a ureteral obstruction in 4 (3.1%), and urinary fistula in 3 (2.4%). In patients with urolithiasis, conservative therapy was effective. An ureteral obstruction was detected on the right side in all 4 of these cases because of the inflamed terminal ileum. In 2 of the 4 cases, the symptoms improved by either preoperative total parenteral nutrition or elemental diet therapy. A resection of the inflamed intestine was necessary in all cases. In patients with urinary fistulas, a resection of the inflamed intestine combined with a reconstruction of the urinary tract was carried out after total parenteral nutrition. In conclusion, conservative therapy with preoperative total parenteral nutrition or elemental diet therapy proved to be effective for a ureteral obstruction since it improved the intestinal inflammation. As a definitive treatment, surgery is still necessary for the management of urinary fistulas and ureteral obstruction. Based on our findings, patients with urolithiasis in Crohn's disease should thus be treated conservatively in the same way as patients without Crohn's disease.

Adolescent↗

PubMed1999

Turcot syndrome with colonic obstruction and small intestinal invagination: report of a case.

We report herein the case of a 16-year-old boy diagnosed as having Turcot syndrome, otherwise known as glioma-polyposis syndrome. The patient was transferred from the Department of Neurosurgery where he was undergoing investigation of a brain tumor, to the Department of Medicine for investigation of gastrointestinal symptoms. The patient was diagnosed as having Turcot syndrome, and was then transferred to the Department of Surgery for treatment of an obstruction in the sigmoid colon and small intestinal invagination. A subtotal colectomy with side-to-end ileoproctostomy and release of the invaginations was carried out. Multiple polyps were found in the colon, two of which, including a large polyp that obstructed the colonic lumen, were confirmed histologically to be adenocarcinoma. The remaining polyps were adenomas. A biopsy of the brain tumor confirmed a diagnosis of astrocytoma (WHO grade II). This case report describes the characteristic features of Turcot syndrome presented by this patient.

Adenocarcinoma↗

PubMed1999

Familial hyperparathyroidism: report of a case.

We report herein a case of familial primary hyperparathyroidism diagnosed in a 23-year-old woman who presented with hypercalcemia and urolithiasis. The parathyroid gland was removed, and pathological examination revealed chief cell adenoma. The proband's younger sister had undergone surgery for parathyroid adenoma at the age of 19, and her aunt had a history of urolithiasis with a high level of serum parathyroid hormone. We have not yet found evidence of any other endocrine disorders suggesting multiple endocrine neoplasia (MEN) type 1 in this pedigree.

Adenoma↗

PubMed1999

Exercise training protects against contraction-induced lipid peroxidation in the diaphragm.

Endurance exercise training promotes a small but significant increase in antioxidant enzyme activity in the costal diaphragm (DIA) of rodents. It is unclear if these training-induced improvements in muscle antioxidant capacity are large enough to reduce oxidative stress during prolonged contractile activity. To test the hypothesis that training-related increases in DIA antioxidant capacity reduces contraction-induced lipid peroxidation, we exercise trained adult female Sprague-Dawley (n = 7) rats on a motor-driven treadmill for 12 weeks at approximately 75% maximal O2 consumption (90 min/day). Control animals (n = 8) remained sedentary during the same 12-week period. After training, DIA strips from animals in both experimental groups were excised and subjected to an in vitro fatigue contractile protocol in which the muscle was stimulated for 60 min at a frequency of 30 Hz, every 2 s, with a train duration of 330 m. Compared to the controls, endurance training resulted in an increase (P < 0.05) in diaphragmatic non-protein thiols and in the activity of the antioxidant enzyme superoxide dismutase. Following the contractile protocol, lipid peroxidation was significantly lower (P < 0.05) in the trained DIA compared to the controls. These data support the hypothesis that endurance exercise training-induced increases in DIA antioxidant capacity protect the muscle against contractile-related oxidative stress.

Animals↗

PubMed1999

Colonization of microflora in mice: mucosal defense against luminal bacteria.

To investigate the pathogenesis of inflammatory bowel disease, it is critical to develop a system that uses simple and reproducible models for analyzing the "normal" mucosal defense mechanism. In the present study, germ-free mice were conventionalized by the oral administration of microorganisms prepared from the feces of genetically identical mice. Histological assessment and mucin characterization of small intestine and colon were then carried out. Histological findings in the gut were site-dependent and clearly time-dependent. Acute inflammation was most evident in the cecum. The cecal mucosa exhibited hyperplastic changes in epithelial cells, infiltration of polymorphonuclear cells, crypt abscesses, and epithelial projections on the epithelial surface 7 days after conventionalization. Some of the changes were similar to those seen in human ulcerative colitis. The histological findings in the conventionalized mice were comparable to those in specific pathogen-free mice after 28 days. Mucin histochemistry revealed that bacterial colonization altered the number of rectal goblet cells and the mucin composition in a time-dependent fashion. Although this model shares only some characteristics of human inflammatory bowel disease, it is unique in demonstrating the acquisition of mucosal defense. Understanding of this process is critical for the elucidation of inflammatory bowel disease pathogenesis.

Animals↗

PubMed1999

Isolation of bacteria from cervical lymph nodes in patients with oral cancer.

Thirty patients with oral mucosal cancer were studied in relation to oral mucosal damage and bacterial translocation to the regional lymph nodes in the neck. All 30 patients (gingiva 11, tongue 13, cheek mucosa four, oral floor two) underwent extensive, clean-contaminated, head-and-neck surgery (including neck dissection) with free flap reconstruction. A total of 153 lymph nodes was harvested for microbial and histological examination. Viable bacteria were isolated from 70 lymph nodes (45.8%) from 25 patients (83.3%). Bacterial cells in the nodes were detected by scanning electron microscopy. Bacterial translocation was found more often in metastatic nodes (75.0%) than in uninvolved nodes (40.3%) (p = 0.015; chi2 test). Gingival carcinoma yielded 56.4% of bacterial growth in the regional lymph nodes compared to tongue (40.3%), oral floor (40.0%) and cheek mucosa (37.5%). As the gingival carcinoma group includes more T4 cases (11/11; 100%) than the other three groups (7/19; 36.8%), bacterial translocation in uninvolved nodes could be caused by the size and invasion of the primary oral tumor. Oral streptococci (Streptococcus intermedius, Strep. constellatus, Strep. oralis, Strep. mitis, Strep. sanguis, Strep. salivarius) were the most common isolates. Aerobic enteric bacteria (Enterococcus, Escherichia, Klebsiella etc.) were also found in the lymph nodes. Among the anaerobic bacteria, Peptostreptococcus spp. were isolated from 12 patients. Damaged oral mucosa in patients with oral cancer might allow the new bacterial colonization on the surface and subsequently drain the bacteria into the regional lymph nodes as well as the general circulation.

Bacteria↗

PubMed1999

Prevalence of GBV-C/hepatitis G virus viraemia among blood donors, health care personnel, chronic non-B non-C hepatitis, chronic hepatitis C and hemodialysis patients in Egypt.

A new RNA virus, designated GBV-C/hepatitis G virus (HGV) has been identified recently. To evaluate the prevalence of GBV-C/HGV infection among Egyptians, five groups were enrolled in this study: group I, healthy blood donors (82); group II, health care personnel (30); group III, chronic non-B non-C hepatitis patients (63); group IV, chronic hepatitis C patients (100); group V, renal dialysis patients (79). GBV-C/HGV-RNA was detected by nested reverse transcription-polymerase chain reaction (RT-PCR) using primers derived from 5'-non coding region of GBV-C/HGV. GBV-C/HGV-RNA was detected in 57 of 354 tested sera with an overall prevalence of 16.1%. Meanwhile, isolated GBV-C/HGV infection was detected in 16/57 (28.1%), GBV-C/HGV coinfection with hepatitis C virus (HCV) in 37/57 (64.9%) and with hepatitis B virus (HBV) in 4/57 (7.6%) of cases. The highest prevalence was encountered among dialysis patients reaching 30% followed by chronic hepatitis C (14%), blood donors (12.2%), chronic non-B non-C hepatitis (11.1%), whereas the lowest prevalence rate of 6.6% was detected among health care personnel. Nucleotide sequence analysis in three Egyptians confirmed that these PCR products were derived from GBV-C/HGV genome and all isolates classified into US/European type (type 2) of GBV-C/HGV genotypes. The risk factors of all cases were non-transfusion parenteral exposure, e.g. reusing syringes, dental treatment, surgery, invasive medical maneuvers, with an exception of renal dialysis patients who have had repeated blood transfusion. It is concluded that there is a relatively high prevalence of GBV-C/HGV-RNA among different Egyptian groups compared to international figures. The main risk factors were direct percutaneous exposure rather than blood transfusion. The Egyptian GBV-C/HGV isolates are very similar to the American isolate PNF 2161.

Base Sequence↗

PubMed1999

Neurological prognosis correlated with variations over time in the number of subependymal nodules in tuberous sclerosis.

In tuberous sclerosis (TS), brain CT reveals subependymal nodules, cortical tubers and white matter lesions. This study is a retrospective analysis of the relationship between the variations over time in the number of subependymal nodules and the clinical course in cases of tuberous sclerosis. Twenty-four children with tuberous sclerosis, who attended the National Children's Hospital as outpatients, were followed by means of brain CT examinations for 7 years and 1 month on average. Cranial MRI was also performed in 22 cases. Brain CT disclosed subependymal nodules already in early infancy. In almost all cases, the number of subependymal nodules gradually increased with age, especially around the frontal horn of the lateral ventricle. The increase stopped at around age 10. The cases with five or more subependymal nodules at the initial or subsequent CT examination ( 17 patients; Group A) exhibited a significantly greater number of cortical tubers than those with less than five (five patients; Group B) and had white matter lesions unlike Group B. In addition, the number of cases with either infantile spasms or mental retardation was significantly higher in Group A than Group B (P < 0.005). In conclusion, the number of ventricular subependymal nodules may allow prediction of the severity of the cerebral dysfunction in TS. Our results suggest that its variation may reflect the degree of the embryologic disorder when neuronal cells grow in the early gestational period.

Adolescent↗

PubMed1999

Intragastric capsaicin stimulates motility of upper gut and proximal colon via distinct pathways in conscious dogs.

The aim of the present study was to investigate the effect and mechanism of action of intragastric and intraduodenal capsaicin on gastrointestinal motility. Five mongrel dogs were equipped with eight strain gauge force transducers on the stomach, small intestine, and proximal colon. In the interdigestive state, capsaicin was administered into the gastric or duodenal lumen. The effects of atropine, hexamethonium, ondansetron, and FK888 on capsaicin-induced contractions were studied. Intragastric capsaicin induced contractions within 15 min in the gastric antrum, duodenum, proximal jejunum, and proximal colon. These stimulatory effects were inhibited by atropine at all sites; by hexamethonium in the small intestine and colon; by ondansetron in the antrum, duodenum, and colon; and by FK888 in the antrum and colon, respectively. Intraduodenal capsaicin had no effect on contractility. Stimulation of afferent fibers by capsaicin in the stomach but not in the duodenum augments contractile activity in local and distant regions of the gut via distinct pathways.

Animals↗

PubMed1999

Remodeling of vascular wall in Crohn's disease.

To clarify the changes in vascular resistance in Crohn's disease, we studied changes in the thickness of arterial media histometrically. The resected specimens of mesenterium and intestine from 18 patients with Crohn's disease were used. Each intestinal lesion was classified into three grades: no inflammation, exudative change, and fibrosing change. In the ileum, significant atrophy in the media of the submucosal peripheral arteries was noted during exudative and fibrosing changes, while in the submucosal larger vessels or in the mesenterium, the thickness of the arterial media did not change. In the colon, atrophy in the media of the submucosal arteries was noted in all stages except in the larger vessel during exudative change, while no significant changes were noted in the mesenterium. In conclusion, it is suggested that circulatory disturbance occurs even in the early stage in Crohn's disease, and there seems to be increased vascular resistance in the area between the deep submucosal and the distal mesenteric arteries.

Adult↗

PubMed1999

Neurological complications after stem cell transplantation in childhood.

We analyzed the incidence of neurological complications in 77 patients receiving stem cell transplantation (SCT), and 12 patients (15.8%) had the following symptoms: convulsions, intracranial hemorrhage, and leukoencephalopathy. Although statistically not significant, neurological complications were seen more frequently in patients after allogeneic transplantation, and in those with acute graft-versus-host disease (GVHD) exceeding grade II. The most significant risk factor for neurological complications was identified as unrelated donor allogenic transplantation (P = 0.016). Complications were categorized into three groups, based on time of onset and symptoms: (1) convulsions during the conditioning period, (2) intracranial hemorrhage during the period of granulocyte recovery, and (3) leukoencephalopathy at around 2 months after SCT. We propose awareness of the risks of neurological complications in each period after SCT so that immediate and effective treatment of patients can be instigated.

Adolescent↗

PubMed1999

Obesity is associated with increased myocardial oxidative stress.

OBJECTIVE: To determine: 1) whether obesity predisposes the myocardium to oxidative stress as evidenced by higher tissue levels of myocardial lipid peroxidation, and 2) what cellular mechanisms are responsible for this predisposition. DESIGN: Comparative, descriptive study of the myocardial tissue of lean and obese Fatty Zucker animals. ANIMALS: 12 month old lean (-/fa; n = 6; mean body weight = 590 g) and obese (fa/fa; na = 7; mean body weight= 882 g) male Fatty Zucker rats. MEASUREMENTS: Basal lipid peroxidation (assessed using thiobarbituric reactive acid substances (TBARS) and cumene hydroperoxide equivalents), oxidative and antioxidant enzyme activities (citrate synthase (CS), superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT), thiol content, heat shock protein expression (HSP72/73) and TBARS concentrations following an iron-mediated challenge in vitro. RESULTS: Compared to lean, lipid peroxidation was greater (P < 0.05) in the left ventricle (LV) from obese rats as indicated by higher levels of lipid hydroperoxides (mean = 11.48 vs 13.7 cumene hydroperoxide equivalents (CHPE)/mg lipid) and TBARS (mean = 11.1 vs 13.9 nMol/mg lipid.). The activity of the manganese isoform of superoxide dismutase in the LV was higher (P < 0.05) in obese animals, compared to controls (mean = 135 vs 117 U/mg protein). In contrast, LV catalase and glutathione peroxidase activities did not differ (P > 0.05) between groups. Also, LV levels of HSP 72 (inducible) and 73 (constitutive) did not differ (P > 0.05)( between lean and obese animals. Following an iron-stimulated oxidative challenge in vitro, TBARS concentration was significantly greater (P < 0.05) in LV of obese rats compared to the lean (mean = 12.7 vs 16.7 nMol/mg lipid). CONCLUSIONS: These results support the notion that obesity predisposes the myocardium to oxidative stress. However, the postulate that obesity is associated with elevated myocardial antioxidant enzyme activities and HSPs was only partially supported by these findings.

Animals↗

PubMed1999

The effects of exercise duration on adrenal HSP72/73 induction in rats.

This study investigated the effects of varying durations of exercise training on heat shock proteins 72 and 73 (HSP72/73) induction in the rat adrenal gland. Female Sprague-Dawley rats (120 days old) were assigned to either a sedentary control group (C) or one of the three endurance exercise training groups. Trained animals ran on a treadmill at approximately 75% VO2max for 10 weeks (4-5 days week-1) at one of the three different exercise durations (30 min day-1=T30, 60 min day-1=T60, or 90 min day-1=T90). All durations of exercise training resulted in an increase in the HSP72 levels (P < 0.0001). The magnitude of the training-induced elevation in the HSP72 levels in the adrenal gland increased as a function of the training duration ( approximately 60-fold increase in T90; approximately 40-fold increase in T60; and approximately 15-fold increase in T30). Longer exercise durations (>60 min day-1), also resulted in small but significant increase in HSP73 level ( approximately 1.2-fold increase in both T60 and T90; P < 0.05). These results demonstrate that the physiological stress created by chronic treadmill running can induce both HSP72 and HSP73 in rat adrenal gland. Increased levels of adrenal HSP72/73 expression during rigorous exercise, may be one of the adaptive mechanisms of the adrenals to cope with an increased dose of stress.

Adaptation, Physiological↗

PubMed1999

Lipopolysaccharide- and proinflammatory cytokine-induced energy production in intestinal and colonic epithelial cell lines.

BACKGROUND: Although epithelial cells in ulcerative colitis may be metabolically deficient, it remains unknown whether epithelial cells modulate energy metabolism in inflamed mucosa. The purpose of the present study is to investigate whether inflammatory mediators such as lipopolysaccharide (LPS), interleukin-1beta (IL-1beta), IL-6, and tumor necrosis factor-alpha (TNF-alpha) alter energy metabolism in epithelial cells. METHODS: Adenosine 5'-triphosphate (ATP) levels in HT29 cells cultured with LPS, IL-1beta, IL-6, or TNF-alpha were measured with high-performance liquid chromatography, using a reversed-phase chromatography column. Cellular and mitochondrial (antimycin A-sensitive) respiration rates were determined polarographically, using a Clark-type oxygen electrode. RESULTS: When the cells were cultured with LPS, IL-6, and TNF-alpha but not IL-1beta, ATP levels increased significantly at 6 h, followed by a decrease at 24 h. Enhancement of oxygen consumption, which was completely blocked by antimycin A, was also shown at 3 h by the exposure to these substrates. CONCLUSION: LPS and proinflammatory cytokines induced cellular ATP generated by mitochondrial phosphorylation. An active energy production in epithelial cells on the exposure to inflammatory mediators may be critical for escape from chronic mucosal inflammation.

Adenosine Triphosphate↗

PubMed1999

A case of interleukin-6-producing malignant fibrous histiocytoma originating in the heart.

Primary cardiac malignant fibrous histiocytoma is extremely rare and its pathophysiological characteristics remain largely unknown. We treated a female patient with persistent fever and disseminated intravascular coagulation. Since ultrasonic echocardiography revealed the presence of a cardiac tumor and her serum interleukin-6 level was elevated, we speculated she had a cardiac myxoma. Histological examination of the surgically resected specimen, however, revealed that the tumor was malignant fibrous histiocytoma. Although her disseminated intravascular coagulation and heart failure were transiently improved after operation, local recurrence and systemic metastasis occurred and she died 7 weeks after operation. Using the autopsied specimen, we examined whether the malignant fibrous histiocytoma constitutively synthesized interleukin-6. The interleukin-6 content in the tumor was high, consistent with interleukin-6 production by the tumor. This was confirmed by immunohistochemical analysis. To our knowledge, this is the first report demonstrating interleukin-6 production by a cardiac malignant fibrous histiocytoma.

Aged↗

PubMed1999

Characterization of human serum mannan-binding protein promoter.

Serum mannan binding protein (MBP), a mannose/N-acetylglusosamine-specific lectin, is important in innate immunity. In order to elucidate the mechanism underlying the wide intra- and interracial variety in the MBP serum level, we have studied the transcriptional regulation of human MBP. Rapid amplification of cDNA ends (5' RACE) analysis of Hep G2 RNA indicated the presence of a novel exon, designated as "exon 0," upstream of previously identified exon 1 [Taylor, M.E. et al. (1989) Biochem. J. 262, 763-771]. Two MBP mRNAs with different sized 5'-noncoding regions were detected: the longer transcript starts at exon 0 and the shorter one at exon 1. Promoter analysis involving a luciferase assay vector revealed that the transcript starting from exon 1 predominates over that starting from exon 0. In addition, a hepatocyto-specific nuclear factor, (HNF)-3, which is known to control the expression of hepatocyto-specific genes, up-regulates the transcription of human MBP from exon 1, while a glucocorticoid, which is known to up-regulate acute phase proteins, markedly suppresses MBP transcription. Recently, polymorphisms were found to occur in the promoter region at two positions [Madsen, H.O. et al. (1995) J. Immunol. 155, 3013-3020]. Functional promoter analysis indicated that three haplotype variants as to these positions, HY, LY, and LX, exhibit high, medium and low promoter activity, respectively, in accordance with the results of a previous population study.

Base Sequence↗

PubMed1999

Identification of a novel genotype of hepatitis G virus in Southeast Asia.

Hepatitis G virus (HGV) isolates obtained from 20 Myanmarese and 10 Vietnamese subjects were analyzed. A cluster of isolates not belonging to any known genotype of HGV was found in five Myanmarese subjects and three Vietnamese subjects by phylogenetic analysis, and we classified this new genotype as type 4. These results revealed that the HGV genome can be classified into at least four major genotypes.

5' Untranslated Regions↗

PubMed1999

Induction of epithelial Na+ channel in rat ileum after proctocolectomy.

In patients with colectomy, epithelial transport function in the remnant small intestine can be regulated in response to the increased fecal electrolyte and fluid loss. Using a rat colectomy model, we investigated the Na+ and K+ transport mechanisms underlying the intestinal response. Proctocolectomy with ileoanal anastomosis was performed on rats. The small intestinal mucosa was mounted in Ussing chambers; then short-circuit currents and 22Na+ fluxes were measured. mRNA expression of the epithelial Na+ channel (ENaC) was determined by Northern blotting. Amiloride-sensitive, electrogenic Na+ absorption appeared in the ileum after proctocolectomy. This functional change was accompanied by the chronological induction of mRNAs for alpha-, beta-, and gamma-subunits of the ENaC in the ileum. Tetraethylammonium-sensitive short-circuit current was also activated. We conclude that electrogenic Na+ absorption and probably K+ secretion are induced in the ileum after proctocolectomy. This induction of electrogenic Na+ absorption is probably mediated by the increase in the mRNA levels for all three types of subunits of the ENaC and may contribute to the recovery from the increased fecal Na+ loss.

Aldosterone↗