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Biomedical subjects

K Kanazawa

Publications and source records attributed to K Kanazawa.

At least 37 records · Page 2Linked to original sources
PubMed2000

Variations in motor evoked potential latencies in the anal sphincter system with sacral magnetic stimulation.

PURPOSE: The anal sphincter system of the skeletal musculature consists of various parts but functions as a single unit. The motor latencies measured at the puborectalis, deep external anal sphincter, superficial external anal sphincter, and subcutaneous external anal sphincter have yet to be clearly elucidated. This study was designed to measure the motor latencies of these sphincters separately and to investigate the electrophysiologic heterogeneity of the anal sphincter system. METHODS: In 20 preoperative patients with colon cancer without either neurologic or anorectal diseases, motor evoked potentials were taken separately bilaterally at levels measuring approximately 5, 3.8, 2.6, and 1.5 cm from the perineal skin using a concentric needle electrode after magnetic stimulation on the sacral region. These latencies were considered to be separately measured at the puborectalis, deep, superficial, and subcutaneous external anal sphincter. RESULTS: The motor latencies (median (95 percent confidence interval)) were 4.33 (4.1-4.93; right) and 4.24 (3.97-5.22; left) ms at the 5 cm level; 5.96 (5.45-7.32; right) and 6.44 (5.49-8.20; left) ms at the 3.8 cm level; 9.28 (7.99-11.21; right) and 8.88 (7.68-10.93; left) ms at the 2.6 cm level; and 11.06 (9.69-14.13; right) and 9.18 (8.09-10.31; left) ms at the 1.5 cm level. Significant differences were seen in the latencies between the 5 cm level and the other levels and between the 3.8 cm level and the other levels. CONCLUSIONS: The motor latencies in the anal sphincter system significantly varied depending on the distance from the skin. The latency may be shortest in the puborectalis and increasingly longer in the deep, superficial, and subcutaneous EAS, in that order.

Aged↗
PubMed2000

Development of duodenal cancer in a patient with familial adenomatous polyposis.

A Japanese woman with familial adenomatous polyposis in whom a duodenal ampullary adenoma underwent malignant change during a 10-year follow-up period is reported. After restorative proctocolectomy in 1989, and extensive small bowel resection for desmoid disease in 1991, regular surveillance duodenoscopies, including three to nine biopsies (mean, 4.8) were performed annually or biannually. Until 1995, the endoscopic findings of duodenal polyposis (including an ampullary polyp) did not progress and the histopathology did not worsen. In 1996, there was an increase in the number and size of the duodenal polyps, and the ampulla of Vater looked enlarged. Open surgery was discussed but not proceeded with because of the risk for short bowel syndrome. In January 1998, she was admitted with a diagnosis of acute pancreatitis. Duodenoscopy and radiological examination revealed that an advanced ampullary cancer had developed, and histopathology revealed a well-differentiated adenocarcinoma. Multiple hepatic metastases and ascites led to her death, in June, 1998. This in-vivo demonstration of the adenoma-carcinoma sequence highlights current limitations in the surveillance and treatment of duodenal lesions.

Adenomatous Polyposis Coli↗
PubMed2000

Cytokine and hormonal responses in laparoscopic-assisted colectomy and conventional open colectomy.

Interleukin-6 (IL-6) is an important mediator of the acute phase response and a sensitive marker of tissue damage. This study was conducted to investigate the fluctuation of serum cytokine and hormonal levels during the perioperative period after laparoscopic-assisted colectomy (LAC), and the data were compared with those after conventional open colectomy (OPEN). The subjects comprised eight patients who underwent OPEN and eight who underwent LAC. Blood samples were obtained by peripheral vein puncture before the induction of anesthesia, then 2, 4, 6, 8, 24, 48, and 72 h after skin incision to measure the levels of serum IL-6, adrenocorticotropic hormone (ACTH), cortisol, and antidiuretic hormone (ADH). The level of serum IL-6 increased significantly during the perioperative course in both groups; however, the level 4 h after the commencement of surgery and the peak level were significantly lower in the LAC group than in the OPEN group (P < 0.05). Plasma ACTH, cortisol, and ADH rapidly increased in both groups, but there was no significant difference between them. The IL-6 levels in collected ascites samples were not significantly different between the two groups. The changes in serum IL-6 levels indicate that LAC is less invasive than conventional open colectomy. These findings corresponded well with the clinical courses of the patients who underwent the two types of operations.

Adrenocorticotropic Hormone↗
PubMed2000

Esterification of polyunsaturated fatty acids by various forms of immobilized lipase from Rhizomucor miehei.

Ethyl esterification specificity of a lipase from Rhizomucor miehei for polyunsaturated fatty acids (PUFA) was compared at 1 and 100 mM to study molecular recognition of PUFA. The chemical shift of methylene adjacent to carboxyl groups in the nuclear magnetic resonance spectrum of docosahexaenoic acid (DHA) in ethanol moved to a lower magnetic field as the concentration of DHA increased, suggesting that the degree of dissociation of DHA decreased. Specificity constants or apparent second-order rate constants (Vmax/Km or catalytic power) for 1 mM esterification by immobilized lipases were higher than the native lipase. Immobilized hydrophobic carrier of low mass transfer resistance for the esterification substrate may improve maximal velocity and affinity for the substrate. Higher specificity constants for 1 mM substrates were observed using immobilized lipases fixed on an anion exchange resin with glutaraldehyde and on a cation exchange carrier with carbodiimide. Activity yields measured with 1 mM PUFA substrate were high. For the substrates at a concentration of 100 mM, higher specific constants with these bifunctional reagents were not observed but higher activity yields were found.

Anions↗
PubMed2000

T102C polymorphism of the serotonin (5-HT) 2A receptor gene in patients with non-fatal acute myocardial infarction.

Serotonin (5-HT), released from activated platelets, has been implicated in the pathogenesis of acute myocardial infarction (AMI). 5-HT induces platelet aggregation and vascular contraction through 5-HT2A receptor activation at sites of coronary atherosclerosis, leading to thrombus formation. Recently, a 5-HT2A receptor gene T102C polymorphism has been reported to be associated with clinical response to 5-HT2A receptor antagonist in patients with schizophrenia, suggesting this polymorphism of the gene affects the 5-HT2A receptor function. To investigate the relationship between the T102C polymorphism and AMI, we conducted a case-control study of 255 non-fatal AMI patients and 255 control subjects. Among the patients, the prevalence of TT genotype was significantly higher than in controls (32.5 vs. 24.3%; P<0.05). In male patients (n=216), the prevalence was much higher than in control subjects (33.8 vs. 24. 1%, P<0.03). In multiple logistic regression models, odds ratio of TT genotype was 1.45 (95% CI 0.96-2.20) in all and 1.61 (95% CI 1. 03-2.53) (P<0.05) in males. The association of T102C polymorphism of the 5-HT2A receptor gene with non-fatal AMI was statistically significant and independent of other risk factors in males. The TT genotype of the 5-HT2A receptor gene may enhance susceptibility to AMI. Our observations suggest that the T102C polymorphism of the 5-HT2A receptor gene can serve as a new genetic marker for AMI.

Aged↗
PubMed2000

High content of dopamine, a strong antioxidant, in Cavendish banana.

A strong water-soluble antioxidant was identified in the popular commercial banana Musa cavendishii. It is dopamine, one of the catecholamines. For suppressing the oxygen uptake of linoleic acid in an emulsion and scavenging a diphenylpicrylhydrazyl radical, dopamine had greater antioxidative potency than glutathione, food additives such as butylated hydroxyanisole and hydroxytoluene, flavone luteolin, flavonol quercetin, and catechin, and similar potency to the strongest antioxidants gallocatechin gallate and ascorbic acid. Banana contained dopamine at high levels in both the peel and pulp. Dopamine levels ranged from 80-560 mg per 100 g in peel and 2.5-10 mg in pulp, even in ripened bananas ready to eat. Banana is thus one of the antioxidative foods.

Antioxidants↗
PubMed2000

Carvedilol improves endothelium-dependent dilatation in patients with coronary artery disease.

OBJECTIVE: Flow-mediated, endothelium-dependent dilatation (FMD) of the coronary and peripheral circulation is impaired by increased oxidative stress in patients with coronary artery disease (CAD). Carvedilol is a novel beta-blocker that also shows an antioxidant effect in vitro. However, the effect of carvedilol on endothelial dysfunction associated with established coronary atherosclerosis has not been examined in the clinical setting. METHODS: We studied 29 patients with CAD, including 17 with recent myocardial infarction and 12 with stable effort angina pectoris. Nineteen patients received carvedilol (10 with infarction and 9 with angina), and 10 were treated with placebo (7 with infarction and 3 with angina). We also studied 13 age- and sex-matched control subjects. Brachial FMD during reactive hyperemia and nitroglycerin-induced, endothelium-independent dilatation were assessed by high-resolution ultrasound. RESULTS: FMD was smaller in patients with CAD compared with controls, although nitroglycerin-induced dilatation was similar. Carvedilol significantly improved FMD after long-term treatment (5. 1% +/- 0.4% at baseline to 7.8% +/- 0.3% after 4 months; P <.01) but not after short-term treatment (5.1% +/- 0.4% at baseline to 5.0% +/- 0.7% after 2 hours). Placebo therapy had no effect on endothelial dysfunction. Neither carvedilol nor placebo had an effect on nitroglycerin-induced dilatation after short- and long-term treatment. Long-term carvedilol therapy also significantly decreased the plasma level of thiobarbituric acid-reactive substances compared with placebo (carvedilol, 5.8 +/- 0.4 nmol/mL to 4.6 +/- 0.3 nmol/mL, P <.01; placebo, 5.9 +/- 0.4 nmol/mL to 5.8 +/- 0.4 nmol/mL, P = not significant). CONCLUSION: These findings suggest that the improvement of endothelial function by carvedilol may be caused by its antioxidant activity.

Adrenergic beta-Antagonists↗
PubMed2000

End-to-side pudendal nerve anastomosis for the creation of a new reinforcing anal sphincter in dogs.

BACKGROUND: An ideal reinforcing neo-sphincter should be innervated by the pudendal nerve to work in coordination with the external anal sphincter. The aim of this study was to create a skeletal muscle innervated by the pudendal nerve without inducing external anal sphincter morbidity. METHODS: Seven dogs were used. On the right side of each dog, the distal end of the transected nerve innervating the biceps femoris muscle was anastomosed to the perineural window of the pudendal nerve, where the epineurium was excised over a small area without injuring the funiculus. Reinnervation was studied 5 months after the operations. The left side of the dogs was used as a control. RESULTS: For all 7 dogs, there was no macroscopic difference detected in the external anal sphincter. For 6 dogs, the biceps femoris muscle was preserved after end-to-side pudendal nerve anastomosis. After the pudendal nerve central to the anastomosis site was electrically stimulated, the external anal sphincter contracted in all dogs. After end-to-side pudendal nerve anastomosis, the biceps femoris muscle contracted with the evoked potential in 5 dogs (71%) and demonstrated electric activity at rest in 3 dogs (43%), but there was no reflex activity after anal stimulation. The ratio of type 1 to type 2 muscle fiber in the biceps femoris muscle after end-to-side pudendal nerve anastomosis significantly changed and became the same as that in the external anal sphincter. The diameter of type 2 muscle fibers in the biceps femoris muscle significantly decreased after surgery. In addition, regenerated myelinated axons were observed in a cross section of the anastomosed nerve in 6 dogs. CONCLUSIONS: End-to-side pudendal nerve anastomosis is a promising technique for the creation of an anal sphincter in patients who have fecal incontinence. The technique preserved the original external anal sphincter and created a skeletal muscle that was innervated by the pudendal nerve in 71% of the dogs studied. This newly innervated skeletal muscle was capable of contracting in coordination with the original external anal sphincter on electric stimulation and also demonstrated characteristics closely similar to those of the external anal sphincter.

Anal Canal↗
PubMed2000

Hysteroscopic appearance of the mid-secretory endometrium: relationship to early phase pregnancy outcome after implantation.

A total of 172 patients who underwent hysteroscopic assessment of the endometrium and then became pregnant, was analysed retrospectively to explore the relationship between endoscopic findings and early phase pregnancy outcome after implantation. Histological examination of the endometrium and assay of serum progesterone and oestrogen were carried out simultaneously with hysteroscopy. Of 172 patients, 12 were excluded. Of the remaining 160 patients, 62 (38.8%) were classified endoscopically as having 'good' mid-secretory endometrium and 98 (61.3%) as 'poor', between one and four cycles prior to the conception cycle. There were no clinical differences between these two groups, except that the frequency of patients with a history of early abortion was significantly higher in the 'poor' group (25.5%) than in the 'good' group (8.1%) (P < 0.05). Of 160 pregnancies, 118 persisted successfully to live birth, but 42 ended in early pregnancy loss. The incidence of early abortion was significantly higher in the 'poor' group (33.7%) than in the 'good' group (14.5%) (P < 0.05). Significant differences were observed between the two groups for histological dating of the endometrium (P < 0.05) but not for serum progesterone and oestradiol concentrations or progesterone:oestradiol ratio. In conclusion, our data suggest that the hysteroscopic appearance of the mid-secretory endometrium at this stage of the menstrual cycle is a better prognostic factor for pregnancy outcome than hormonal data.

Adult↗
PubMed2000

Combined effects of meropenem and aminoglycosides on Pseudomonas aeruginosa in vitro.

To investigate combinations of antibiotics against Pseudomonas aeruginosa, the in vitro effects of combinations of meropenem with each of three aminoglycosides, arbekacin, amikacin and netilmicin, were evaluated using an agar dilution chequerboard technique. The combinations of meropenem and aminoglycosides were effective against almost all P. aeruginosa strains tested, which included meropenem-resistant strains. Increased synergic effects were observed in combinations that included arbekacin or amikacin. None of the combinations had an antagonistic effect. Most of the synergic and additive effects were achieved at clinically relevant concentrations.

Aminoglycosides↗
PubMed2000

Treatment of malignant ovarian germ cell tumors with preservation of fertility: reproductive performance after persistent remission.

To describe our experience with malignant ovarian germ cell tumors with special reference to reproductive performance after remission, medical records of 31 patients were reviewed. The mean age at diagnosis was 18.6 years. Tumor by stage was I in 16 cases, II in 5, III in 5, IV in 3, and recurrence in 2. Histology was dysgerminoma in 7 cases, yolk sac tumor in 10, immature teratoma in 7, choriocarcinoma in 1, and mixed-type tumor in 6. Conservative surgery for fertility preservation was performed in 21 cases. Postoperative chemotherapy was given to all cases except two with stage Ia dysgerminoma. Of 31 cases, 4 including one fertility-preserved case died of disease. The other 27 cases including 20 fertility-preserved cases were successfully treated. Twenty-five cases (92.6%) have been followed longer than 60 months and 13 cases (48.1%) longer than 120 months. By the last follow-up, 8 of the 20 fertility-preserved cases delivered a total of 9 normal babies. Of the remaining 12 nonpregnant cases, 3 married, 9 have had regular menses, and 3 have had menstrual problems. Two of the latter three cases have been in hypergonadotropic anovulatory cycles. One patient has been diagnosed with tubal infertility caused by peritubal adhesion. Thus, management of the disease with fertility preservation is safe and the majority of patients can attain or retain normal ovarian function and reproductive potential.

Adolescent↗
PubMed2000

Use of fusion images of I-131 metaiodobenzylguanidine, SPECT, and magnetic resonance studies to identify a malignant pheochromocytoma.

Pheochromocytoma is a chromaffin tumor in which 10% are extra-adrenal and 10% are malignant. I-131 metaiodobenzylguanidine (MIBG) scintigraphy has an important role in the identification of these tumors and investigation of metastatic lesions. The authors describe a 36-year-old woman who underwent resection of a malignant left adrenal pheochromocytoma who was thought to have metastases in the liver and para-aortic lymph nodes. Fusion images of I-131 MIBG SPECT and magnetic resonance studies were obtained to properly identify the metastatic lesions. These fusion images helped greatly in subsequent surgery.

3-Iodobenzylguanidine↗
PubMed2000

Therapeutic value of selective salpingography for infertile women with patent fallopian tubes: the impact on pregnancy rate.

OBJECTIVE: To determine the therapeutic value of selective salpingography (SSG) for infertile women with patent fallopian tubes. DESIGN: Retrospective, case-control analysis. SETTING: University Hospital, infertility clinic. PATIENTS: Infertile cases with patent tubes documented by hysterosalpingography (HSG) or by HSG followed by laparoscopic examination (n = 80). INTERVENTION(S): Hysteroscopic SSG. MAIN OUTCOME MEASURE(S): Patency rate of tubes by SSG. Pregnancy rate following SSG. RESULT(S): Eighty cases were divided into the study group (SSG performed, 37 cases) and the case-control group (SSG not performed, 43 cases). Successful SSG of at least one tube was obtained in all of 37 cases (100%) in whom SSG was attempted. A patency rate of 95.9% was documented in the 73 cannulated tubes of these cases. The total subsequent pregnancy rate (48.6%) within 12 months of follow-up after SSG was significantly higher than that (11.6%) obtained in the control group (p < 0.001). The cumulative pregnancy rate in the study group was also significantly higher than that in the control group (p < 0.001). CONCLUSION(S): The findings of the present study encourage the application of SSG to infertile women, either as a sole therapeutic approach or in association with other methods of assisted reproductive technology, even if their fallopian tubes are shown to be patent by HSG.

Adult↗
PubMed2000

Endothelial nitric oxide synthase gene mutation and human leukocyte antigen analyzed in three cases of familial vasospastic angina pectoris.

A 50-year-old woman with rest angina underwent cardiac catheterization; coronary angiography in the presence of acetylcholine revealed 99% coronary spasm of the proximal left anterior descending artery. The patient's 82-year-old mother was also admitted to hospital with rest angina. Her Holter electrocardiogram showed ST-segment elevation during the attack at rest and coronary angiography showed 99% spasm of the right coronary artery and 90% spasm of the left coronary artery. Both women complained of chest pain during the spasm, which was accompanied by ST-segment depression. The 62-year-old brother of the original patient was also found to have coronary spasm of the left coronary artery. Human leukocyte antigen was analyzed in the 2 women: A2, B51, CW1, DR8 and DQ1 were common factors. A Glu298Asp point mutation of the endothelial nitric oxide synthase gene was investigated in both parents, their 2 daughters and 2 sons, but was not detected in the 3 patients, and was detected only in the 90-year-old father who did not suffer from angina. Nor was the T-786-C mutation found in the 3 cases. Other causes of familial spasm need to be elucidated.

Aged↗
PubMed2000

Cytochrome P4501A1-inhibitory action of antimutagenic anthraquinones in medicinal plants and the structure-activity relationship.

We have earlier found that flavones and flavonols in vegetables specifically inhibited one of the carcinogenesis-related enzymes, cytochrome P450 (CYP) 1A1, and subsequently suppressed the mutagenicity of food-derived carcinogens. In this study, we explored other candidates for the enzyme inhibitor in Chinese medicinal plants. Some of them were antimutagenic toward 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2). For example, Rheum officinale contained large amounts of anthraquinones as the active compounds, 3.4 mg of emodin, 2.1 mg of chrysophanol and 1.8 mg of rhein in 10 g of dry matter. Anthraquinones showed similar IC50 values for antimutagenicity against Trp-P-2 to those for inhibition of the N-hydroxylation activity of CYP1A1 toward Trp-P-2, indicating that the antimutagenicity was attributable to CYP inhibition. The structure-activity relationships were then examined with 14 commercial chemicals, and it was found that the interaction with an enzyme required three rings and an oxygen group in the side ring. This characteristic is similar to that of flavones and flavonols.

Anthraquinones↗