Search PubMed⌕ Search

Biomedical subjects

K Yamaguchi

Publications and source records attributed to K Yamaguchi.

At least 55 records · Page 3Linked to original sources
PubMed2003

Colonic transit time and rectoanal videomanometry in Parkinson's disease.

BACKGROUND: Constipation is a prominent lower gastrointestinal tract dysfunction that occurs frequently in Parkinson's disease (PD). OBJECTIVE: To investigate colonic transport and dynamic rectoanal behaviour during filling and defecation in patients with PD. METHODS: Colonic transit time (CTT) and rectoanal videomanometry analyses were performed in 12 patients with PD (10 men and 2 women; mean age, 68 years, mean duration of disease, five years; mean Hoehn and Yahr grade, 3; decreased stool frequency (<3 times a week) in six, difficulty in stool expulsion in eight) and 10 age matched normal control subjects (7 men and 3 women; mean age, 62 years; decreased stool frequency in two, difficulty in stool expulsion in two). RESULTS: In the PD patients, CTT was significantly prolonged in the rectosigmoid segment (p<0.05) and total colon (p<0.01) compared with the control subjects. At the resting state, anal closure and squeeze pressures of PD patients were lower than those in control subjects, though not statistically significant. However, the PD patients showed a smaller increase in abdominal pressure on coughing (p<0.01) and straining (p<0.01). The sphincter motor unit potentials of the patients were normal. During filling, PD patients showed normal rectal volumes at first sensation and maximum desire to defecate, and normal rectal compliance. However, they showed smaller amplitude in phasic rectal contraction (p<0.05), which was accompanied by an increase in anal pressure that normally decreased, together with leaking in two patients. During defecation, most PD patients could not defecate completely with larger post-defecation residuals (p<0.01). PD patients had weak abdominal strain and smaller rectal contraction on defecation than those in control subjects, though these differences were not statistically significant. However, the PD patients had larger anal contraction on defecation (p<0.05), evidence of paradoxical sphincter contraction on defecation (PSD). CONCLUSIONS: Slow colonic transit, decreased phasic rectal contraction, weak abdominal strain, and PSD were all features in our PD patients with frequent constipation.

Adult↗
PubMed2003

Association of CYP2A6 deletion polymorphism with smoking habit and development of pulmonary emphysema.

BACKGROUND: Nicotine is responsible for smoking dependence and is mainly metabolised by CYP2A6. Several types of genetic polymorphism of CYP2A6 have been reported, but their relation to smoking habit and chronic obstructive pulmonary disease (COPD) phenotypes has not been fully clarified. METHODS: 203 current or ex-smokers (lifelong cigarette consumption (CC) >/=10 pack years) with subclinical and established COPD phenotypes were clinically evaluated and pulmonary function tests and a chest CT scan were performed (smoker group). The non-smoker group consisted of 123 healthy volunteers. CYP2A6 genotypes were determined in both groups. RESULTS: The percentage of subjects with a CYP2A6del allele (genotype D) was lower in heavy smokers (20.5%, n=88, CC >/=60 pack years) than in light smokers (37.4%, n=115, CC 10-59 pack years, chi(2)=6.8, p=0.01) or non-smokers (36.1%, n=122, chi(2)=6.0, p=0.01); lower in ex-smokers (20.7%, n=111) than in current smokers (41.3%, n=92, chi(2)=10.1, p<0.01); and lower in smokers with a high LAA (low attenuation area) score on the chest CT scan (18.4%, n=76, LAA >/=8.0) than in those with a low LAA score (37.0%, n=127, LAA <8.0, chi(2)=7.8, p<0.01). CONCLUSIONS: Subjects with the CYP2A6del allele tend not to be heavy habitual smokers but can be light habitual smokers. The CYP2A6del polymorphism may inhibit smokers from giving up smoking, but appears to function as a protective factor against the development of pulmonary emphysema independent of smoking habit.

Aged↗
PubMed2003

Expression analysis of vascular endothelial growth factors and their relationships to lymph node metastasis in human colorectal cancer.

This study was undertaken to determine whether expressions of the vascular endothelial growth factor (VEGF) family (VEGF-A, VEGF-B, VEGF-C, and VEGF-D) are correlated with clinicopathological parameters, with particular reference to lymph node metastasis in colorectal cancer. Total RNA was isolated from 82 surgical specimens of colorectal cancer and matched to normal mucosa with (n = 41) or without (n = 41) lymph node metastasis. The mRNA expression of each VEGF family member was quantified by real-time quantitative (RTQ) RT-PCR assay. VEGF-B and VEGF-C mRNA were significantly higher both in the tumors with lymph node metastasis (p = 0.027 and p = 0.024, respectively) and in tumors with lymphatic invasion (p = 0.042 and p = 0.005, respectively). In contrast, VEGF-D mRNA was down-regulated in tumors with lymphatic involvement (p = 0.047). Among the other clinicopathological factors, we noted that VEGF-A mRNA was higher in tumors with liver metastasis than in those without (p = 0.018) and was higher in tumors with venous invasion than in those without (p = 0.007). The results of this study demonstrate that high levels of VEGF-B, C and low levels of VEGF-D mRNA expression are associated with lymph node metastasis and lymphatic involvement. These results suggest that a balance among VEGF-B, VEGF-C, and VEGF-D might contribute to the lymphangiogenic process and metastasis in colorectal cancer.

Aged↗
PubMed2002

Development of port-site metastasis after pneumoperitoneum.

BACKGROUND: Port-site metastasis is a critical problem in laparoscopic cancer surgery; the pathogenesis and means of prevention are still unclear. The aim of this study was to clarify by scanning electron microscopy the initial morphologic changes in the development of port-site metastasis. METHODS: Fifteen nude mice were injected with human gastric cancer (MKN 45) cells. Mice were killed on days 0, 3, and 8 (n = 5 each day) after intraperitoneal injection of 5 x 105 cancer cells and carbon dioxide (CO2) pneumoperitoneum at 4-6 mmHg for 20 min. The abdominal wall with the port sites was harvested and examined under both light and scanning electron microscopy. RESULTS: Immediately after CO2 pneumoperitoneum (day 0), the abdominal peritoneum was peeled away and the muscular layer was destroyed at the port site in all mice. Several cancer cells were attached to the injured port sites. On day 3, the subperitoneal tissue and muscular layer defects were replaced by granulation tissue, and several cancer cells were observed in the subperitoneal tissue. On day 8, a small nodule was macroscopically visible at the port site; it was completely covered by mesothelial cells and consisted of numerous cancer cells. CONCLUSIONS: Free cancer cells appear to attach to the injured port sites immediately after CO2 pneumoperitoneum, and these are associated with the development of port-site metastasis after laparoscopic cancer surgery.

Animals↗
PubMed2002

High expression of transgenes mediated by hybrid retroviral vectors in hepatocytes: comparison of promoters from murine retroviruses in vitro and in vivo.

To achieve high transgene expression in the liver, we have compared the reporter gene expression among various murine retroviral long terminal repeats (LTRs) or leader sequences in vitro. Transient reporter gene expression assays revealed the highest gene expression by the polycythemic strain of spleen focus-forming virus (SFFVp) LTR in differentiated hepatocellular carcinoma cell lines, HuH-7 and PLC/PRF/5. However, remarkable difference was not observed among LTRs in other types of human liver tumor cell lines. Essentially the same results were obtained by infecting these cells with a series of retroviral vectors. Repression of transgene expression was observed by the leader sequences from Moloney murine leukemia virus (MoMLV), but not from mouse embryonic stem cell virus (MESV). Strengths of the promoters were further compared in murine hepatocytes in vivo. Although the proportions of genomic integration were almost the same, higher gene expression was observed by the FMEV-type vector, which contained the SFFVp LTR and the MESV leader, in comparison with that by the MoMLV-based vector. Thus, FMEV-type vectors may represent a novel type of vectors for human gene therapy with hepatocytes.

Animals↗
PubMed2002

Differences in the fatigue of masticatory and neck muscles between male and female.

The purpose of this study was to investigate the nature of fatigue and recovery of masticatory and neck muscles and the differences between sexes in normal subjects during experimentally induced loading. Subjects consisted of eight males (mean age: 27.6 years) and eight females (mean age: 24.2 years) selected from the volunteers in the Faculty of Dentistry, Hiroshima University. The inclusion criteria for the subjects were as follows: (1) good general health, (2) normal horizontal and vertical skeletal relationships, (3) no severe malocclusions and (4) no complaints of temporomandibular disorders. Each subject was requested to bite an occlusal-force meter with 98, 196 and 294 N forces on the first molar region per side for 45 s. Activities of the masseter and sternocleidomastoid (SCM) muscles were recorded during these performances. Fatigue and recovery ratios were calculated with mean power frequency of power spectrum using a fast Fourier transform algorithm. Significant differences in the fatigue ratios between both sexes were found for the masseter muscle with 98, 196 and 294 N bite forces. Meanwhile, the SCM presented a significant difference between both sexes only at 98 N biting. Significant differences in the recovery ratios between both sexes were more prominent in the masseter muscle than in the SCM. These results suggest that the differences in muscle endurance between sexes may have some association with higher susceptibility of craniomandibular disorders in females than in males.

Adult↗
PubMed2002

Association of dietary fatty acids with urinary oxalate excretion in calcium oxalate stone-formers in their fourth decade.

OBJECTIVE: To examine the influence of the dietary intake of fatty acid on urinary oxalate excretion in calcium oxalate stone-formers in their fourth decade, as previous reports show that animal fat intake is associated with urinary oxalate excretion. PATIENTS AND METHODS: The dietary intake of 58 idiopathic stone-formers in their fourth decade was recorded using the dietary-record method. The patients collected 24-h urine samples at home and their urinary oxalate excretion was measured in a clinical biochemistry laboratory. The results were used to determine the relationship between the dietary intake of fatty acids and urinary oxalate excretion. Associations between urinary oxalate excretion and dietary contents of animal fat, animal protein and various fatty acids were assessed using Spearman's correlation coefficient and multiple regression. RESULTS: The dietary content of arachidonic acid was positively correlated with urinary oxalate excretion, as assessed by univariate and multivariate analysis. CONCLUSION: The association between arachidonic acid and oxalate excretion suggests that arachidonic acid increases the intestinal absorption of oxalate and increases the clearance of oxalate in the kidneys.

Adult↗
PubMed2002

Laparoscopic adrenalectomy: comparison of transperitoneal and retroperitoneal approaches.

OBJECTIVE: To compare the effectiveness and efficiency of transperitoneal anterior laparoscopic adrenalectomy with that of retroperitoneal posterior laparoscopic adrenalectomy. PATIENTS AND METHODS: A retrospective comparison was undertaken of 28 patients who underwent transperitoneal anterior laparoscopy with 22 patients who underwent retroperitoneal posterior laparoscopy between April 1994 and November 2000. There were 18 men and 32 women (mean age 51.0 years, range 23-68) with varying diagnoses. Of the 50 patients, 31 had primary aldosteronism, eight had Cushing's syndrome, three had phaeochromocytoma, one had an 18-hydroxydeoxycorticosterone-induced adenoma and seven had non-functioning adrenal adenoma. Adrenal tumours were confirmed by hormonal assays, biochemical tests and computed tomography. To determine the site of the functioning adenoma, hormones were assayed from adrenal vein sampling. Thirty adrenal tumours were located on the right and 20 on the left. RESULTS: There were no significant differences in general demographic variables between the transperitoneal and retroperitoneal groups. The mean duration of surgery for transperitoneal and retroperitoneal laparoscopy was 202 and 221 min, respectively, and the mean blood loss 113 and 192 mL, respectively. The time to first oral intake, days to full diet, time until ambulatory and duration of hospitalization did not differ significantly between the two approaches. As the body mass index increased, the duration of surgery increased for both approaches. As more procedures were performed the duration of surgery decreased for both approaches. CONCLUSIONS: There were no significant differences between the transperitoneal and retroperitoneal approaches for laparoscopic adrenalectomy.

Adrenal Gland Diseases↗
PubMed2002

Similarities and differences between Alzheimer's disease and vascular dementia from the viewpoint of nutrition.

Dietary habits were compared in patients with Alzheimer's disease (AD) and those with vascular dementia (VaD). Twenty-seven patients with AD, 15 patients with VaD, and 49 age-matched controls were enrolled. Nutritional status was assessed using a semiquantified food-frequency questionnaire. Dietary habits were very similar in male patients with AD and VaD. Both groups had significantly higher energy intake than their energy demands: +25% for AD and +35% for VaD, respectively. However, major sources of energy were different: grains and animal fats for AD versus only grains for VaD. Calculation of nutrients revealed excess intake of n-6 polyunsaturated fatty acids (PUFA) and relative deficiencies of multiple vitamins including antioxidants, vitamin C and carotene, and the vitamin B group. In contrast, dietary habits in female patients with AD differed significantly from those of male patients. Female patients consumed significantly lower amounts of fish and green vegetables. Calculation of nutrients showed absolute deficiencies of n-3 PUFA, multiple vitamins, and minerals. Our results show that AD and VaD are similar from the viewpoint of nutrition, except for the higher consumption of animal fats for AD patients, probably reflecting Westernization of dietary habits in recent years. Nutrition may be relevant to the pathogenesis of dementia through many processes. Higher intake of energy and lower intake of antioxidants may exaggerate the process of dementia through oxidative stress. Excessive amounts of n-6 PUFA or deficiency of n-3 PUFA may cause chronic inflammation, platelet aggregation, or endothelial dysfunction of microvasculature. Nutrition may be useful for preventing dementia, although gender-specific differences must be taken into account.

Aged↗
PubMed2002

Correlation between cathepsin D expression and p53 protein nuclear accumulation in oesophageal squamous cell carcinoma.

AIM: The lysosomal protease cathepsin D has been reported to be associated with tumour progression in malignant tumours. Expression of the gene encoding cathepsin D is known to be stimulated by oestrogen in mammary cancer cells. Recent experiments revealed that a p53 DNA binding site is located in the promoter region of the cathepsin D gene. This fact indicates that cathepsin D expression may correlate with p53 protein expression. The purpose of this study is to evaluate the expression patterns of the cathepsin D and p53 proteins in oesophageal squamous cell carcinoma (SCC). METHODS: In 154 patients with oesophageal SCC, expression of the cathepsin D and p53 proteins was measured in tumours by means of immunohistochemistry using monoclonal antibodies against cathepsin D (clone, 1C11) and p53 (clone, BP53-12). RESULTS: Cathepsin D was detected in tumour cells, although it was not found in normal oesophageal epithelium adjacent to carcinoma. High cathepsin D expression (positive tumour cells > 10%) was detected in 76 of 154 cases (49%) and high p53 nuclear expression (positive tumour cells > 50%) was detected in 70 cases (46%). High cathepsin D expression was significantly associated with invasive tumour growth (p = 0.002), poor prognosis (p = 0.049), and nuclear accumulation of p53 protein (p = 0.001). Overexpression of both p53 and cathepsin D was seen in 45 of the 154 cases (29.2%). In addition, there was a positive correlation between the cathepsin D index (percentage of cathepsin D positive tumour cells) and Ki-67 labelling index (percentage of Ki-67 positive tumour cells) in 154 oesophageal SCCs (rho = 0.257; p = 0.009). However, in multivariate survival analysis, cathepsin D expression by the tumours was not an independent prognostic factor in patients with oesophageal SCC (p = 0.236). CONCLUSIONS: The expression of cathepsin D by cancer cells may play an important role in the invasive growth of oesophageal SCC. Overexpression of both p53 and cathepsin D was seen frequently in tumours; p53 gene abnormalities may correlate with cathepsin D overexpression in oesophageal SCC.

Aged↗
PubMed2002

NOS and COX isoforms and abnormal microvessel responses to CO2 and H+ in hyperoxia-injured lungs.

The aim of the present study was to compare microvessel responses to hypercapnic and isocapnic acidosis in hyperoxia-injured lungs and to assess the role of constitutive and inducible forms of nitric oxide synthase (NOS) and cyclo-oxygenase (COX). Real-time confocal luminescence microscopy was used to measure changes in the diameter of acinar arterioles, venules and capillaries in response to stimulation with hypercapnic and isocapnic acidosis in isolated rat lungs injured by 90% oxygen exposure for 48 h. Observations were made with and without inhibition of constitutive (endothelial constitutive NOS (ecNOS) and COX-1) and inducible isoforms (iNOS and COX-2) of NOS and COX. Upregulation of NOS was assessed by measuring enzyme levels in lung homogenates by Western blot analysis and enhancement of the COX-related pathway was judged from perfusate concentrations of 6-ketoprostaglandin F1alpha. ecNOS and COX-1, but not iNOS and COX-2, were upregulated in hyperoxia-injured lungs. The nitric oxide produced by ecNOS attenuated COX-1 activity in injured arterioles and venules, but carbon dioxide enhanced it, leading to paradoxical dilatation of these microvessels under hypercapnic conditions with ecNOS inhibition. Although a high hydrogen ion concentration was unnecessary for excitation of COX-1, venule constriction in response to H+ was enhanced by COX-1 inhibition. Constitutive, but not inducible, isoforms of cyclo-oxygenase and nitric oxide synthase play an important role in abnormal microvessel responses to carbon dioxide and hydrogen ions in hyperoxia-injured lungs.

Acidosis, Respiratory↗
PubMed2002

Fenofibrate improves insulin sensitivity in connection with intramuscular lipid content, muscle fatty acid-binding protein, and beta-oxidation in skeletal muscle.

We investigated the effect of fenofibrate, a peroxisome proliferator-activated receptor-alpha agonist, on insulin sensitivity including lipid metabolism in skeletal muscle. Six-week-old male Sprague-Dawley rats were divided into two groups: those fed a standard chow (control) or a fructose-rich chow (fructose-fed rats (FFRs)) for 6 weeks. FFRs were treated either with a vehicle or with 30 mg/kg per day of fenofibrate for the last 2 weeks. Insulin sensitivity (M-value) was estimated by the euglycemic hyperinsulinemic glucose clamp method. Fatty acid-binding protein (FABP) in skeletal muscle was measured by ELISA, and the expression of FABP mRNA was analyzed by semi-quantitative RT-PCR. The serum and muscle triglyceride (sTG and mTG) levels and the activity of 3-hydroxyacyl-CoA dehydrogenase (HADH), a beta-oxidation enzyme, in muscle were also determined. FFRs showed a lower M-value and higher blood pressure, sTG and mTG than did the control group. The mTG was correlated positively with sTG and negatively with the M-value. Fenofibrate treatment for 2 weeks did not change blood pressure but significantly improved the M-value, sTG and mTG. FABP content and mRNA in the soleus muscle were significantly elevated in FFRs compared with those in the control group. Fenofibrate treatment further increased FABP. The HADH activity was comparable between the control group and FFRs, but significantly increased by fenofibrate treatment. These results suggest that fenofibrate improves insulin sensitivity not only by lowering serum lipids and subsequent influx of fatty acids into muscles but also by reducing intramuscular lipid content via further induction of FABP and stimulation of beta-oxidation in muscles.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed2002

Detection of mycobacteria in patients with pulmonary tuberculosis undergoing chemotherapy using MGIT and egg-based solid medium culture systems.

SETTING: National Minami-Yokohama Hospital, Kanagawa, Japan. OBJECTIVE: To compare the performance of a liquid medium system using the Mycobacteria Growth Indicator Tube (MGIT) with that of the conventional Japanese culture system using egg-based Ogawa medium, equivalent to Lowenstein-Jensen medium, in cases with pulmonary tuberculosis on chemotherapy. DESIGN: A single-centre prospective case study of 61 hospitalised patients from 1 May to 31 July 1998 on a standard 6-month regimen of anti-tuberculosis chemotherapy including isoniazid, rifampin, streptomycin or ethambutol, and pyrazinamide. Sputum cultures using both culture systems were performed bi-weekly up to week 16 of treatment, and were further monitored by MGIT alone at the end of chemotherapy and every 6 months after the end of chemotherapy up to 2 years. RESULTS: The detection time by MGIT gradually became longer with the progression of chemotherapy. The recovery rate at weeks 2, 4, 6, 8, and 10 by MGIT were significantly higher (P < 0.05) than on the Ogawa slants. Although one case was microbiologically diagnosed as a relapse, using the more sensitive MGIT system did not increase the relapse rate. CONCLUSION: The gradual prolongation of detection time with the progression of treatment and an attainment of negativity of sputum culture at 4 months after chemotherapy could be a useful intermediate marker to monitor the efficacy of treatment for patients with pulmonary tuberculosis by the MGIT system. Further evaluation is necessary to establish the utility of MGIT in monitoring the treatment process.

Antitubercular Agents↗
PubMed2002

Detection of peritoneal micrometastases by reverse transcriptase-polymerase chain reaction targeting carcinoembryonic antigen and cytokeratin 20 in colon cancer patients.

Peritoneal recurrence after curative resection of malignant tumor with negative cytology is considered to be caused by microscopic dissemination of the exfoliated cancer cells from primary tumors to serosal surfaces at the time of operation, not detectable with conventional diagnostic tools. We applied the reverse transcriptase-polymerase chain reaction (RT-PCR) for carcinoembryonic antigen (CEA) and cytokeratin 20 (CK 20) to detect micrometastatic foci in the peritoneal cavity of colon cancer patients. Cytological samples taken by peritoneal lavage from a series of 79 colon cancer patients were analyzed microscopically, for CEA levels, and by RT-PCR analysis using nested primers for CEA and CK 20. Cases with both CEA and CK 20 signals were defined as PCR-positive. This RT-PCR method proved both sensitive (1 tumor cell/10(6) non-tumor cells on preparation of serial colorectal cancer cell dilutions) and specific (no false positive results, 0/23 tested in our control experiment). Intraperitoneal micrometastatic cells were detected in peritoneal lavage 7.6% by cytology, 17.7% by CEA levels, and 24.1% by RT-PCR (significantly higher than by cytology: p=0.0046). RT-PCR detection rate increased in parallel with pathological depth of tumor invasion, and also a pathological stage-dependence was suggested according to the tumor-node-metastasis classification of the International Union Against Cancer. Our results suggest that CEA and CK 20 mRNA identification by RT-PCR appeared to be reliable and may be useful for early diagnosis in peritoneal dissemination of colon cancer.

Aged↗