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Biomedical subjects

K Kitamura

Publications and source records attributed to K Kitamura.

At least 307 records · Page 17Linked to original sources

Plasma adrenomedullin levels in patients with non-insulin dependent diabetes mellitus: close relationships with diabetic complications.

The present study was undertaken to determine plasma adrenomedullin levels in patients with non-insulin dependent diabetes mellitus (NIDDM) to elucidate the potential involvement in the pathogenesis of diabetic complications. The patients were 24 males and 21 females with ages of 55 +/- 2.1 years (mean +/- SEM). Plasma adrenomedullin levels were 5.94 +/- 0.44 pmol/l in patients with NIDDM, and were not affected by plasma glucose concentration. The plasma adrenomedullin increased dependent on the severity of diabetic nephropathy and retinopathy. Plasma levels of adrenomedullin positively correlated with various parameters, including serum creatinine levels, urinary excretion of protein, and systolic blood pressure. In contrast, there were negative correlations between the coefficient variation (CV) of RR intervals and plasma adrenomedullin, and between the conduction velocity of ulnar nerves and plasma adrenomedullin levels. These results indicate that the increase in plasma adrenomedullin was closely related to diabetic complications, which may be dependent on the development of microangiopathy.

Adrenomedullin↗

Dissociation of adrenomedullin concentrations in plasma and cerebrospinal fluid in pregnant and non-pregnant women.

Adrenomedullin (AM), a potent vasodilator peptide, has been shown to act within the central nervous system to modulate fluid and electrolyte balance. AM-immunoreactive cells have been found in the anterior pituitary gland and the choroid plexus of humans. In addition, AM activity has been implicated in the regulation of maternal circulation during pregnancy. To determine the relationship between AM concentration in the cerebrospinal fluid (CSF) and plasma, we measured AM levels in CSF and plasma of pregnant (group P, n = 12) and non-pregnant (group NP, n = 10) women scheduled to undergo gynecologic or obstetric surgery. In both groups, the concentration of AM in the plasma exceeded that in the CSF. Plasma AM concentration was significantly higher in pregnant than non-pregnant women (17.3+/-5.8 vs 5.1+/-1.4 pmol/l, mean +/- S.D.; P<0.01), whereas CSF AM concentration did not differ between the two groups (1.3+/-0.9 and 0.9+/-0.4 pmol/l in groups P and NP respectively). No significant correlation was found between AM concentrations in the CSF and plasma. The present findings suggest that AM is present in the CSF and that its concentration in the CSF is regulated independently from that in the plasma.

Adrenomedullin↗

Improvement of a mouse feeder for chemical toxicology testing.

A mouse feeder in common use in the US was modified to eliminate spillage, contamination by excreta and formation of food aggregates. The improved feeder consists of a glass jar which holds 100 g of meal-type feed, an inner metal mesh tube, a marble placed inside the inner mesh tube, and a snap-on metal lid. Female mice [B6C3F1 and CD-1(ICR)] were housed 5 animals/cage. Only slight contamination by feces, but not by urine, was observed in a 13-week feeding study with Japanese meal-type food and the improved feeder. Food spillage also decreased. Food consumption was significantly higher in cages with the conventional Japanese feeder than in the improved one, but no difference was observed between the two feeders in body weight gain.

Animal Feed↗

Role of endothelium and adventitia on eugenol-induced relaxation of rabbit ear artery precontracted by histamine.

Eugenol (> or = 0.1 mM) inhibited the contractions induced by various stimulants, such as 90 mM extracellular K+ solution ([K+]0), histamine and noradrenaline in the rabbit ear artery. Inhibitory actions of eugenol occurred in a concentration-dependent manner, however, eugenol more dominantly inhibited the histamine-induced contraction than those induced by either 90 mM [K+]0 solution or noradrenaline. Removal of both endothelium and adventitia did not change the inhibitory actions of eugenol on the 90 mM [K+]0- and noradrenaline-induced contractions, however, attenuated those on the histamine-induced contraction. Chlorphenylamine abolished the histamine-induced contraction, but neither cimetidine, ranitidine nor thioperamide modified the eugenol actions on the contractions induced by histamine. Pretreatment with nitric oxide syntheses inhibitor NG-nitro-L-arginine (LNNA; 100 microM), but not soluble guanylate cyclase inhibitor methylene blue (MB; 10 microM), prevented endothelium/adventitia-dependent augmentation of the eugenol-induced relaxation on the histamine-induced contraction. When an intact tissue, but not an endothelium/adventitia-denuded tissue, was placed at the up-stream close to the other denuded preparation (test preparation), histamine-induced contraction observed in the test preparation tended to be augmented. Similarly, eugenol-induced relaxation was also augmented by the same treatment. Eugenol (0.3 mM) inhibited the excitatory junction potentials (EJPs) without hyperpolarization of the membrane. However, a high concentration of eugenol (1 mM) slightly hyperpolarized the membrane (ca. 5 mV). No transient enhancement of amplitude of EJP was recorded. These results suggest that eugenol may inhibit the histamine-induced muscle contraction directly, and the inhibition is augmented by the adventitia and endothelium partly by vasoactive substances, which were released from the adventitia/endothelium-derived substances in rabbit ear artery.

Animals↗

Simultaneous activation of Ca(2+)-dependent K+ and Cl- currents by various forms of stimulation in the membrane of smooth muscle cells from the rabbit basilar artery.

In smooth muscle cells isolated from cerebral blood vessels, histamine activates Cl- channels through an elevation of intracellular Ca2+. We investigated whether Cl- currents were also evoked by adenosine triphosphate (ATP) or caffeine in isolated smooth muscle cells from the rabbit basilar artery using the perforated patch-clamp technique. Bath application of 10 microM ATP or 1 mM caffeine (holding potential -60 mV) activated transient inward currents. With prolonged bath application of 10 microM ATP or 1 mM caffeine, oscillatory inward current were sporadically generated. At a holding potential of -40 mV, transient Cl- currents were induced by 10 microM histamine, 10 microM ATP, and 1 mM caffeine, following activation of a K+ current. At -10 or -20 mV, histamine predominantly activated the K+ current. A repetitively activated outward current was induced by membrane depolarization. These results suggest that oscillations in intracellular Ca2+ induced by histamine, ATP, and caffeine caused Cl(-)-current activation at the resting membrane potential. This Cl- current may depolarize the membrane and, thus activate voltage-dependent currents, including a Ca(2+)-dependent K+ current. Both the Ca(2+)-dependent K+ and Cl- currents induced by various stimuli may contribute to the modulation of Ca2+ influx by reinforcing membrane depolarization.

Adenosine Triphosphate↗

Mp colorectal cancer should be defined as early colorectal cancer.

Little is known about the clinicopathologic features of mp colorectal cancer, defined as a cancer where the depth of invasion is limited to within the mucosa, the submucosa and the proper muscle. This study was designed to determine the clinicopathologic features of mp colorectal cancers. From 1973 to 1993, 83 mp colorectal cancer and 66 sm colorectal cancer patients were treated in our department and were enrolled in this study. During the same period, 66 patients with sm colorectal cancer defined as a cancer where the depth of invasion is limited to within the mucosa and the submucosa, were treated. The clinicopathologic findings of these patients were determined retrospectively from their hospital records. Clinicopathologic differences in sm and mp colorectal cancers were compared with sm and mp gastric cancers. The incidence of mp colorectal cancer increased from 7.9% in 1973-1977 to 16.2% in 1988-1993. An advanced macroscopic appearance, a larger tumor size, lymph node metastasis and lymph vessel invasion were more predominant in mp than sm colorectal cancer. Multivariate analysis demonstrated that these clinicopathologic factors were not statistically independent prognostic factors for mp colorectal cancer patients. There was no statistical difference in postoperative survival between sm and mp colorectal cancer patients. Mp colorectal cancer should be defined as early colorectal cancer, because the postoperative survival rate does not differ between mp and sm colorectal cancers, and the clinicopathologic differences between these two are negligible.

Colorectal Neoplasms↗

Disturbance of consciousness associated with hypophosphatemia in a chronically alcoholic patient.

A 69-year-old man with chronic alcoholism was admitted to our hospital due to disturbance of consciousness and oliguria. Emergency laboratory examination revealed metabolic acidosis, hypoglycemia, hyponatremia, mild liver dysfunction, acute renal failure and rhabdomyolysis. After administration of fluids and nutrients and continuous hemodiafiltration, he recovered from all signs and symptoms except for disturbance of consciousness after 7 days. Since severe hypophosphatemia persisted, we administered adequate phosphates, and then his level of consciousness normalized. We discuss the relationships among alcohol abuse, hypophosphatemia and disturbance of consciousness, and recommend that hypophosphatemia be considered a potential cause of disturbance of consciousness in alcoholic patients.

Acidosis↗

[Topical treatment of onychomycosis by occlusive dressing using bifonazole cream containing 40% urea].

Topical treatment with an antifungal agent was performed in 70 cases of onychomycosis (69 cases of tinea unguium and 1 case of Candida onychomycosis). The patients were treated every night by occlusive dressing using bifonazole cream containing 40% urea, and then by simple application of 1% bifonazole solution in the morning. During the treatment period, the softened affected nails were removed as completely as possible with nail clippers and files. The nails were observed every two weeks, and the efficacy was evaluated after 12 weeks. Two cases were excluded and 28 cases dropped out leaving 40 cases for efficacy evaluation. Among the 40 patients, 20 appeared to be mycologically negative (mycological cure rate: 50.0%). Clinical response was judged by the changes in opacity and thickness of the nails. Nine patients were evaluated as showing "marked improvement" and 16 as showing "improvement" (improvement rate: 62.5%). Erosion was noted as an adverse reaction in 2 patients. In one patient, treatment was stopped and the lesion was improved by antibiotic ointment, and in another, treatment was resumed when erosion was cured by discontinuation of the treatment. These results suggest that the topical treatment of onychomycosis by occlusive dressing is a useful method for those patients who have difficulties in or do not wish to be treated with oral antifungal agents.

Administration, Topical↗

[Prefectural health administration's view on otorhinolaryngological care in medical rural areas].

In a previous study, we investigated otorhinolaryngological care by the general practitioners in medical rural areas and demonstrated that a close relationship between general practitioners and otorhinolaryngologists was necessary. In the present study, a survey of prefectural health administration's views on otorhinolaryngological care in medical rural areas was performed. A questionnaire for otorhinolaryngological care in medical rural areas was sent to the divisions of health administration in the 47 prefectures of Japan. Of these prefectures, 46 (97.9%) responded. About 80% of respondents have medical rural areas, and the otorhinolaryngological care is inadequate in most areas. General practitioners of internal medicine or surgery are primarily demanded in about 75% of the prefectures. Otorhinolaryngological care in medical rural areas has never been considered in most prefectures. Because the need for otorhinolaryngological medical care will increase, prefectural health administrations need to pay more attention to otorhinolaryngological care in medical rural areas, and a close relationship between general practitioners, otorhinolaryngologists, and the administration should be established.

Community Health Services↗

[Mediastinal neurilemmoma originating in the right phrenic nerve: a case report].

We report on a 31-year-old man with a mediastinal neurilemmoma originating in the right phrenic nerve. The patient was admitted because of abnormal chest X-ray shadows observed during a routine checkup. A preoperative diagnosis of bronchial cyst in the mediastinum was made. The tumor was resected by video-assisted thoracic surgery. It was 3 x 4 x 3 cm in size, weighted 15 g, and originated in the right phrenic nerve. The histopathologic diagnosis was mediastinal neurilemmoma. Only 14 cases have been reported in the Japanese literature.

Adult↗

[Application of monoclonal antibody for drug delivery system--missile therapy for cancer].

Clinical applications of monoclonal antibody for selective delivery of anticancer drug, toxin and radioisotope were reviewed. The difficulties in preparation and clinical application of chemoimmunoconjugate were pointed out. Also the difficulties of immunotoxin in clinical trial due to its high toxicity had been discussed and it is assumed that development of blocked ricin may overcome many problems related to toxicities. Clinically most advanced immunoconjugate seems to be radioimmunoconjugate. Among three types of immunoconjugates preparation of radioimmunoconjugate is easiest and some promising clinical trials were introduced in this review.

Animals↗

Activation of protein phosphatase 1alpha promoter in ascites hepatoma cells.

We have already reported the nucleotide sequence of 5'-flanking region of rat PP1alpha gene and identified the promoter region in NIH3T3 cells. Here we determined the promoter activity of PP1alpha gene in ascites hepatoma cells and compared with that of hepatocytes. Reporter analysis showed that the promoter activity was enhanced in an ascites hepatoma AH13 compared with normal hepatocytes at two regions, -37 to -198 bp and -492 to -848 bp upstream of the translation start site. At -37 to -198 bp region with high GC content, binding of Sp1 was markedly increased in all of five ascites hepatomas examined. At -492 to -848 bp region, two bands were clearly detected in two of the five ascites hepatomas, AH13 and AH7974F, by gel shift analysis. These results strongly suggest that the increase in PP1alpha mRNA expression in ascites hepatomas is at least in part due to the enhanced promoter activity of PP1alpha gene.

Animals↗

Protection against dynorphin-(1-8) hydrolysis in membrane preparations by the combination of amastatin, captopril and phosphoramidon.

The amounts of dynorphin-(1-8) [dyn-(1-8)] and its seven hydrolysis products, Y, YG, YGG, YGGF, YGGFL, YGGFLR and YGGFLRR, were estimated after incubating dyn-(1-8) with a membrane fraction from either guinea-pig ileum or striatum for various times at 37 degrees C. The major hydrolysis products during the initial 5-min incubation were YGGFLR and Y, which indicates that dipeptidyl carboxypeptidase and aminopeptidase activities were mainly involved in the hydrolysis. After 60 min of incubation, dyn-(1-8) was completely hydrolyzed in both membrane preparations. When the ileal and the striatal preparations were incubated for 60 min in the presence of both captopril, a dipeptidyl carboxypeptidase inhibitor, and amastatin, an aminopeptidase inhibitor, 63.8 and 49.3% of dyn-(1-8), respectively, were hydrolyzed. The YGG fragment was the major hydrolysis product in both preparations. When the ileal and the striatal membrane fractions were incubated with dyn-(1-8) in the presence of three peptidase inhibitors, captopril, amastatin and phosphoramidon (an inhibitor of endopeptidase-24.11), approximately 95% of the opioid octapeptide remained intact in both cases. This shows that dyn-(1-8) was almost exclusively hydrolyzed by three enzymes, amastatin-sensitive aminopeptidase, captopril-sensitive dipeptidyl carboxypeptidase I and phosphoramidon-sensitive endopeptidase-24.11, in both ileal and striatal membranes. Additionally, the Ke (equilibrium dissociation constant) values of selective antagonists against dyn-(1-8) and its initial main hydrolysis product YGGFLR in two isolated preparations pretreated with the three peptidase inhibitors indicate that the latter acts on mu receptors in guinea pig ileum but delta receptors in mouse vas deferens and the former acts on kappa receptors in both preparations. It is indicated, therefore, that in the absence of peptidase inhibitors endogenously released dyn-(1-8) acts either through dyn-(1-8) itself on kappa receptors or through YGGFLR on mu or delta receptors depending on both the three peptidase activities and the three receptor type densities at the target synaptic membrane.

Animals↗

[Postoperative management of the preserved rectal segment in patients with familial polyposis: the use of 5-fluorouracil suppositories and green tea extract to inhibit tumor growth].

We report the clinical details of seven patients with familial polyposis. They underwent subtotal colectomy with ileorectostomy, and were treated with 5-fluorouracil suppositories and green tea extract after surgery. Some regression of the polyps in the preserved rectal segment was observed, and no rectal cancer developed in any of these patients.

Adenomatous Polyposis Coli↗

Transaxillary approach for the endoscopic extirpation of benign breast tumors.

Cosmetic factors in the treatment of breast disease have long been neglected despite the fact that patients are highly concerned about the length and extent of the incision. Recent developments in both endoscopy and endoscopic devices have now made it possible to reach breast mass(es) from small incisions in the axilla. We describe the successful extirpation of a giant fibroadenoma of the breast in a 20-year-old woman, using a 3-mm or 10-mm endoscope and a 3-mm or 5-mm endoscopic device with a transaxillary approach. A scar-free breast with an excellent cosmetic result was achieved by use of this technique and these devices. Benign tumors (both single large tumors and multiple masses) are therefore considered to be ideal candidates for this type of minimally invasive endoscopic surgery.

Adult↗

[Fundamental and clinical studies on tazobactam/piperacillin in the pediatric field].

Pharmacokinetics, efficacy and safety of tazobactam/piperacillin (TAZ/PIPC), a new beta-lactamase inhibitor combined with a penicillin antibiotic, were studied in pediatrics and the following results were obtained. 1) Serum concentration and urinary excretion of TAZ/PIPC after intravenous administration at a dose of 46 mg/kg to one child were investigated. Serum half-lives were 0.5 hours for TAZ and 0.6 hours for PIPC, while the urinary recovery rates in the first 6 hours after administration, were 61.6% and 56.3% respectively. 2) TAZ/PIPC was administered at a dose of 46.0-73.5 mg/kg t.i.d. for 3-13 days to 10 patients, 6 with respiratory infection, 1 with pharyngotonsillitis, 1 with pertussis and 2 with soft tissue infection of skin. Clinical response were excellent in 5 cases and good in 5 cases, and the efficacy rate was 100%. Bacteriologically, 2 strains (Staphylococcus aureus and Streptococcus pyogenes) isolated from 2 patients were eradicated after the treatment. As for adverse reaction, mild skin rash was observed in 1 case but disappeared within 2 days after withdrawal of the drug. As for abnormal laboratory test results decrease in neutrophiles and increase in eosinophiles in each 1 case were observed, which were, however, normalized after administration. From the above results, tazobactam/piperacillin was considered to be a useful antibiotic in the pediatric field.

Bacterial Infections↗