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Biomedical subjects

K Ishida

Publications and source records attributed to K Ishida.

At least 217 records · Page 12Linked to original sources
PubMed1997

Extrapancreatic action of truncated glucagon-like peptide-I in Otsuka Long-Evans Tokushima Fatty rats, an animal model for non-insulin-dependent diabetes mellitus.

To clarify the mechanism(s) of the antidiabetic effects of truncated glucagon-like peptide-1 (GLP-1) in diabetics, we examined its insulinotropic and extrapancreatic effects in a newly established strain of spontaneously non-insulin-dependent diabetic (NIDDM) rats, Otsuka Long-Evans Tokushima Fatty (OLETF) rats, that received a continuous infusion of truncated GLP-1 620 pmol/d/kg (G group, n = 12) or of vehicle (V group, n = 12) for 4 weeks by Alzet pump. Nonfasting plasma glucose levels were significantly lower (P < .05) in the G group than in the V group (7.0 +/- 0.67 v 9.1 +/- 1.7 mmol/L), and fasting plasma immunoreactive insulin (IRI) levels were lower in the former than in the latter (0.63 +/- 0.31 v 0.78 +/- 0.25 nmol/L). At day 15 of infusion, the G group showed an attenuated plasma glucose response to an oral glucose load, but had plasma IRI levels comparable to those in the V group. A long-term infusion of truncated GLP-1 increased the glucose infusion rate (GIR) significantly (P < .05) during a euglycemic-hyperinsulinemic clamp test (59.0 +/- 14.8 mumol/kg/min for group G v 38.9 +/- 12.2 for group V), but hepatic glucose output (HGO) did not differ significantly for either group. Uptake of 2-deoxy-D-glucose (2DG) by peripheral muscles in the G group was as much as 2.4-fold higher than in the V group (5.52 +/- 2.04 v 2.29 +/- 0.97 mumol/100 g muscle weight/min). We conclude from these data that truncated GLP-1, in addition to its well-known incretin effect, is capable of augmenting insulin action in peripheral tissues of diabetics, which can contribute, in part, to improve glucose intolerance in OLETF rats.

Administration, Oral↗
PubMed1997

Cochlear implant after reconstruction of the external bony canal wall and tympanic cavity in radically mastoidectomized patients with cholesteatoma.

One of the postoperative complications of cochlear implants in patients, who previously received radical mastoidectomy, is an exposure of electrode by breakdown of thin epithelium in the open mastoid cavity. To avoid such complications, in the first stage, radical mastoidectomy with the reconstruction of the posterior bony canal wall and mastoid obliteration with bone chips and plates and the creation of the new tympanic cavity, were performed. One or 3 years later, implantation of a 22-channel cochlear implant, as the second stage procedure, was successfully performed in three patients with profound sensorineural hearing loss, due to cholesteatoma in the side of the ear in which cochlear implantation was indicated. The advantages of this technique are as follows: (1) Electrode is protected from the cavity problems, such as chronic infection or erosion of the epithelium in the open mastoid cavity; and (2) reconstruction of the new tympanic cavity and tympanic membrane is beneficial for avoidance of electrode exposure in the mastoid and tympanic cavity.

Aged↗
PubMed1997

Effects of fructose-induced hypertriglyceridemia on hepatorenal toxicity of acetaminophen in rats: role of pharmacokinetics and metabolism of acetaminophen.

Fructose-induced hypertriglyceridemic rats become resistant to hepatotoxicity and susceptible to nephrotoxicity of acetaminophen (APAP), as compared with normal ones. The present study was designed to test the hypothesis that alterations in the distribution of APAP and in the intrinsic susceptibility to toxicants are responsible for the alteration in hepatorenal toxicity of APAP in fructose-induced hypertriglyceridemic rats. Following APAP-administration (750 mg/kg, i.p.), fructose-pretreated rats (25% fructose in drinking water for 5 weeks) showed nephrotoxicity of APAP more promptly and more severely than normal ones. Renal APAP-concentrations at the early phase (15 and 30 min. after APAP-administration) were significantly greater in fructose-pretreated rats than those in normal ones. Plasma and hepatic APAP concentrations in fructose-pretreated rats were greater than those in normal ones only at the later phase (plasma; 6 hr, liver; 6 and 12 hr after APAP-administration). There were no significant differences in the APAP-induced depletion of hepatic and renal glutathione and in the basal hepatic and renal cytochrome P-450 contents between these rats. Fructose-pretreated rats were also more susceptible to p-aminophenol (PAP), a nephrotoxic metabolite of APAP, than normal rats. Therefore, enhanced susceptibility to APAP-nephrotoxicity in fructose-pretreated rats may be due, at least in part, to increased renal APAP concentration and increased intrinsic susceptibility to the metabolic nephrotoxicant.

Acetaminophen↗
PubMed1997

Effects of fructose-induced hypertriglyceridemia on hepatorenal toxicity of acetaminophen in rats. II. Role of enhancement of fructose metabolism and overproduction of triglyceride in the liver and kidney on hepatorenal toxicity of acetaminophen.

Fructose-induced hypertriglyceridemic rats are resistant to hepatoxicity and susceptible to nephrotoxicity of acetaminophen (APAP) as compared with normal ones. The present studied were designed to evaluate how fructose-treatment affects the developmental mode of hepatorenal toxicity of APAP. First, following fructose-pretreatment for various durations (1 day, 1 week or 3 weeks), 1-day-fructose-pretreatment induced hypertriglyceridemia and enhancement of APAP-nephrectoxicity simultaneously. However, it took at least 3 weeks for fructose-pretreatment to reduce APAP-hepatotoxicity. Second, following fructose, sucrose or glucose-pretreatment for 3 weeks, fructose-pretreated rats showed marked hypertriglyceridemia and modification of APAP-hepatorenal toxicity. Sucrose-pretreated rats showed less effects than fructose-pretreated rats. Glucose-pretreated rats showed no changes in plasma triglyceride and APAP-hepatorenal toxicity. Third, rats with hypertriglyceridemia induced by olive oil or Triton WR-1339 which did not produce enhanced metabolism and triglyceride-overproduction in the liver and kidney showed no modification of APAP-hepatorenal toxicity. Pretreatment of glycerol which was metabolized in liver and kidney and induced an overproduction of triglyceride resulted in an enhancement of APAP-nephrotoxicity. These results indicate that an enhancement of fructose metabolism and an overproduction of triglyceride in liver and kidney are responsible for the modification of APAP-hepatorenal toxicity in fructose-induced hypertriglyceridemic rats.

Acetaminophen↗
PubMed1997

Enhanced nephrotoxicity of acetaminophen in fructose-induced hypertriglyceridemic rats: contribution of oxidation and deacetylation of acetaminophen to an enhancement of nephrotoxicity.

Fructose-induced hypertriglyceridemic Sprague-Dawley (SD) rats become resistant to hepatotoxicity and susceptible to nephrotoxicity of acetaminophen (APAP) as compared with normal SD rats. Fischer-344 rats, which are susceptible to APAP nephrotoxicity, have two toxic metabolic pathways involving cytochrome P450-dependent oxidation of APAP to N-acetyl-p-benzoquinone imine (NAPQI) and P450-independent deacetylation of APAP to p-aminophenol (PAP). SD rats, however, have only the former pathway. This study was undertaken to investigate whether alterations in the metabolic pathways of APAP and in the intrinsic susceptibility to toxic metabolites are responsible for an enhancement of APAP nephrotoxicity in the fructose-pretreated SD-rats. In the non-pretreated rats, the inhibition of APAP oxidation by the MFO inhibitor, piperonyl butoxide, and deacetylation by carboxyesterase inhibitor, bis(p-nitrophenyl)phosphate, did not alter APAP-induced renal lesions. In contrast, these inhibitors protected the fructose-pretreated rats from APAP-induced renal lesions. Since there were no differences in the severity of gentamicin-, chloroform, and 45 min-ischemia/reperfusion-induced renal lesions between the non-pretreated and the fructose-pretreated rats, it is unlikely that the increased intrinsic susceptibility to chemicals and their metabolites in the fructose-pretreated rats is a major factor in the enhancement of APAP nephrotoxicity. These results indicate that the enhancement of APAP nephrotoxicity in the fructose-pretreated rats is due, at least in part, to an alteration in metabolic pathways of APAP.

Acetaminophen↗
PubMed1997

Enhanced nephrotoxicity of acetaminophen in fructose-induced hypertriglyceridemic rats: effect of partial hepatectomy.

Fructose-induced hypertriglyceridemic rats become resistant to hepatotoxicity and susceptible to nephrotoxicity of acetaminophen (APAP). Enhanced susceptibility to APAP nephrotoxicity in fructose-pretreated rats is due, at least in part, to increased renal APAP concentration at the early phase (15 and 30 min after APAP administration). However, the mechanism of an increase in renal APAP concentration is still obscure. The present study was designed to test the hypothesis that a decrease in capacity of hepatic APAP metabolism is responsible for an increase in renal APAP concentration in fructose-pretreated rats. Non-pretreated rats and fructose-pretreated rats (25% fructose in drinking water for 3 weeks) received 70% or 90% partial hepatectomy (PH) or sham operation at 1 hr before APAP administration (600 or 750 mg/kg, i.p.). PH did not potentiate APAP nephrotoxicity and renal APAP concentration, and fructose-pretreated rats showed server renal lesions and greater renal APAP concentration than non-pretreated rats irrespective of PH. The result indicates that an increase in renal APAP concentration in the fructose-pretreated rats has no relation to an alteration in hepatic metabolic capacity of APAP.

Acetaminophen↗
PubMed1997

Kawaguchipeptin B, an antibacterial cyclic undecapeptide from the cyanobacterium Microcystis aeruginosa.

Kawaguchipeptin B, an antibacterial cyclic undecapeptide, was isolated from the cultured cyanobacterium Microcystis aeruginosa (NIES-88). Its structure was elucidated as 1 on the basis of 2D NMR data and chemical degradation. Kawaguchipeptin B (1) inhibited the growth of the Gram-positive bacterium Staphylococcus aureus at a concentration of 1 microgram/mL (MIC).

Anti-Bacterial Agents↗
PubMed1997

Expression of neurotrophic factors in cultured human retinal pigment epithelial cells.

PURPOSE: To see if cultured human retinal pigment epithelial (RPE) cells have the capacity to synthesize neurotrophins, including nerve growth factor (NGF), brain-derived growth factor (BDNF), and neurotrophin-3 (NT-3). METHODS: Expression of mRNAs for the neurotrophins was studied by the reverse transcription polymerase chain reaction (PCR) method. Quantitative analysis of the gene expression was done by using a semiquantitative PCR method. Secretion of NGF-like immunoreactivity (NGF-LI) into the culture medium was analyzed by enzyme immunoassay (EIA). RESULTS: Cultured human RPE cells were found to express mRNAs for NGF, BDNF and NT-3. In the conditioned culture medium of the human RPE, 9.44 +/- 0.62 pg/ml (mean +/- SEM, n = 6) NGF-LI was found. Pretreatment of human RPE cells with interleukin-l (IL-1) (20 ng/ml), phorbol myristate acetate (PMA) (100 ng/ml) or tumor necrosis factor-alpha (TNF-alpha) (40 ng/ml) was found to increase the mRNA expression of neurotrophins and also to increase secretion of NGF-LI into the culture medium. CONCLUSIONS: Our data demonstrate that cultured human RPE cells have the capacity to synthesize neurotrophins, and that various stimulations can up-regulate gene and protein expression of NGF by these cells.

Brain-Derived Neurotrophic Factor↗
PubMed1997

External biliary jejunal drainage through a percutaneous endoscopic gastrostomy for tube-fed patients with obstructive jaundice.

We describe a new procedure, which can help patients with obstructive jaundice improve their quality of life (QOL). Although percutaneous transhepatic biliary drainage (PTBD) can relieve jaundice, the procedure has some disadvantages. Percutaneous endoscopic gastrostomy (PEG) is a useful method for providing nutritional support to patients unable to swallow. We have combined these two techniques. We used the combination ofa 20-F catheter and a 9-F jejunal catheter for PEG. The PTBD catheter and the 9-F jejunal catheter are connected outside the patient's body. Externally drained bile from the PTBD catheter can flow back into the jejunum, and the opening between the 20-F catheter and the 9-F jejunal catheter is used for tube feeding. This procedure was adopted in a patient. Since the procedure, the patient's nutritional status and daily living activities have improved. We conclude that the procedure is useful for tube-fed patients with obstructive jaundice.

Aged↗
PubMed1997

MAD-related genes on 18q21.1, Smad2 and Smad4, are altered infrequently in esophageal squamous cell carcinoma.

The MAD (mothers against decapentaplegic)-related genes, Smad2 (former name MADR2 or JV18-1) and Smad4 (former name DPC4), have been identified on chromosome 18q21.1. We analyzed 30 primary esophageal squamous cell carcinomas (ESCC) and 7 cell lines derived from ESCC for intragenic mutations and loss of heterozygosity (LOH) of the Smad2 and Smad4 genes. LOH was detected in 5 of 14 (35%) informative cases. However, no mutations in either gene were detected in either the primary carcinomas or the cell lines, and only a G-to-A base transition within the 3'-untranslated region of the Smad4 gene was observed in a carcinoma. There were no homozygous deletions in either of the genes in the cell lines. MAD-related genes on chromosome 18q21.1 are altered infrequently in ESCC.

Carcinoma, Squamous Cell↗
PubMed1997

[Comparison of echograms by a microscanner and histological findings of the common bile duct, in vitro study].

To confirm the relationship between the layer structure of the common bile duct by a microscanner (MS) and its histological features, we performed a study using the pinning method with needles and catgut. The locations of 67 needles inserted at random depths in 29 slices of the resected common bile duct from 18 patients were confirmed both by a MS and a microscope. The wall of the common bile duct was delineated as a two- (42 points) or three-layer structure (25 points); "low and high" or "high, low, and high echoic layers" from the mucosal side. A fibrotic layer (ss 1) was often (56/67 points, 16/18 patients) seen in the subserosa (ss) containing nerves and vessels larger than 100 mu in diameter. Among the 51 needle echoes demonstrated in the inner hypoechoic layer, 2 were located in the mucosa (m), 12 in the fm, 19 in the af, 17 in the ss 1, and 1 in the fatty layer of the ss (ss 2). Five of the 6 needles in the outer hyperechoic layer were in the ss 2, and 1 was in the pancreatic parenchyma (pa). Four of the 8 needles at the border between the inner hypoechoic layer and the outer hyperechoic layer histologically corresponded to fm, af, ss 1, and pa, respectively, and the other four corresponded to ss 2. From these results, we conclude that the inner hypoechoic layer contains not only m, fm, and af, but also ss 1. Therefore, this should be kept in mind for the preoperative assessment of the depth of bile duct carcinoma by MS.

Bile Duct Neoplasms↗
PubMed1997

A modified stapling technique for esophagojejunostomy after total or proximal gastrectomy.

BACKGROUND: Stapling devices reduce the leakage rate of digestive tract anastomoses, but they increase the risk of strictures. We investigated a newly modified technique of end-to-end anastomosis stapling in esophagojejunostomy after total or proximal gastrectomy. STUDY DESIGN: A modified stapling technique (using a stapled anastomosis between esophageal mucosal and intact jejunal layers, with hand-sewn seromuscular sutures between the esophagus and jejunum) was used in 21 patients (modified group), while a conventionally stapled anastomosis was performed in 17 patients (conventional group). The incidence and severity of dysphagia and the size of the anastomosis as determined from x ray films were compared in the two groups. RESULTS: The modified technique provided significantly better results for dysphagia severity than the conventional method (p = 0.0025). Most of the patients in the modified group had mild dysphagia, and most patients in the conventional group complained of moderate or severe dysphagia. In the modified group, the inner diameter of the anastomosis was 12.1 +/- 2.5 mm, significantly larger than that in the conventional group (10.0 +/- 1.8 mm; p = 0.009). CONCLUSIONS: The use of our modified stapling technique can minimize the risk of anastomotic stricture and the feeling of dysphagia after esophagojejunostomy.

Aged↗
PubMed1997

Cause and repair of flap necrosis over cochlear implant.

OBJECTIVE: The aim of this report was to study the cause and treatment of flap-related complications over cochlear implant. SETTING: The study was performed in an academic tertiary referral center. PATIENT: A 53-year-old Japanese male patient had had two retro-auricular skin incisions for tympanomastoidectomy in the postauricular region before implantation of a cochlear implant. He also had worn a helmet daily during work in his factory. INTERVENTIONS: Corrective surgery was performed for reformation of the local blood supply to the overlying skin flap and reinforcement of the tissue overlying the implant by use of a superiorly based temporal muscle and fascia flap that were sutured with an inferiorly based muscle and fascia flap. RESULTS: We successfully transposed the flap covering the implant without explantation of the implant. CONCLUSIONS: The delayed development of flap necrosis was thought to be due to pressure necrosis produced by the band in the patient's helmet lying on the skin over the implant and to poor local blood supply in the postauricular area stemming from the two previous skin incisions for mastoid surgery performed for cholesteatoma. In those patients who wear helmets, it is important to position the cochlear implant sufficiently behind the ear and to avoid the use of a helmet.

Cochlear Implants↗
PubMed1997

[Clinical experiences with the insertion of dynamic stent for the patients with esophago-tracheal fistula due to advanced esophageal carcinoma--two case reports].

We experienced two cases who were inserted dynamic stent (a tracheobronchial silicone stent) to treat esophago-tracheal fistula due to advanced esophageal carcinoma. This procedure permitted to perform esophageal bypass operation under intubated general anesthesia in the first case. After operation, severe coughing improved so much and he could start oral intake and resulted in better performance status. In the second case, by the insertion of dynamic stent general condition recovered well, so he could achieve full course of chemo-radiotherapy and enter in partial response. Esophago-tracheal fistula due to advanced esophageal carcinoma markedly worsens performance status and its treatment is usually very difficult. The insertion of dynamic stent may improved their quality of life, make it possible to achieve further therapy and improve their prognosis.

Aged↗
PubMed1997

[Advances in molecular biological investigation of blood group-active substances on the human red blood cell].

Blood group antigens on the human red blood cell are originally of serological significance. Recent advances in molecular biology and genetics have greatly increased our knowledge of the chemical structures, functions, and genetic backgrounds of these antigens. Carbohydrate antigens are widely expressed in various tissues, whereas protein(polypeptide) antigens are generally specific to the surface molecules of erythroid cells, suggesting their possible roles in membrane structure and function (transporters, receptors, adhesion molecules, and enzymes). This paper reviewed the recent topics with special regard to clinical significance including blood transfusion, and discussed.

ABO Blood-Group System↗
PubMed1997

[Femoral to radial artery pressure gradient in the patients undergoing coronary artery bypass graft under normothermic cardiopulmonary bypass].

Femoral to radial artery pressure gradient was evaluated in 14 patients undergoing coronary artery bypass graft under normothermic cardiopulmonary bypass (CPB). CPB was instituted at a flow rate of 2.6 l.min-1.m-2, using non-pulsatile pump and blood temperature of pump arterial line was controlled to maintain bladder temperature between 36 and 37 degrees C. Pressure gradients occurred 30 min after commencement of CPB and the mean gradients of systolic, diastolic and mean artery pressure were maximum all at the end of CPB (38 +/- 7 mmHg, 4 +/- 1 mmHg and 10 +/- 2 mmHg). These pressure gradients remained until the end of the surgery. Throughout the operation, nasopharyngeal and blood temperature remained unchanged, while mean palm temperature increased from 31.8 degrees C (after induction) to 34.6 degrees C (30 min after commencement of CPB) and thereafter remained between 33.3 and 33.9 degrees C. This increase in peripheral temperature might indicate that normothermic CPB was accompanied by peripheral vasodilatation. These results indicate that the magnitude of femoral to radial pressure gradient during normothermic CPB is similar to that during mild hypothermic CPB.

Aged↗
PubMed1997

Isolation of cDNA clones for genes that are expressed in the tail region of the ascidian tailbud embryo.

An ascidian tailbud embryo is comprised of the anterior trunk and posterior tail. We constructed cDNA libraries of the tail region and trunk region of the ascidian Halocynthia roretzi. The screening of the tail library by tail single-stranded cDNA minus the trunk library RNA as a probe, yielded cDNA clones for genes that are expressed in the tail epidermis, visceral ganglion, trunk lateral cells, muscle cells, and certain regions of the tail. Among them, a cDNA clone for a gene designated HrPost-1 is described in detail. HrPost-1 encodes a novel, possible secreted protein of 238 amino acids. The expression of the gene is zygotic. HrPost-1 transcript was first evident in the posterior B-line blastomeres including muscle cells and endodermal strand cells of the gastrula-stage embryo, and the expression in these regions disappeared by the early tailbud stage. Around neurulation, the HrPost-1 transcript appeared in epidermal cells of the posterior-most region of the embryo. As development proceeded, the gene expression spread anteriorly in the epidermal cells of the neurula and tailbud embryo, and thus at the early-to-mid tailbud stage, HrPost-1 expression appeared to define the boundary between the trunk and tail epidermis. These results suggest that, in addition to tissue-specific genes, the activities of a set of region-specific genes are associated with tail formation in the ascidian embryo.

Amino Acid Sequence↗