Biomedical subjects

T Kaneko

Publications and source records attributed to T Kaneko.

At least 307 records · Page 17Linked to original sources

PubMed1999

Blood biochemical characteristics, cecal microbiota and short-chain fatty acid composition in fistula implanted rats.

We raised an experimental rat implanted with a cecal fistula and investigated various characteristics of fistula-implanted rats. Male F344/N Sic rats at 14 weeks of age were divided into three groups, the fistula group (n = 5) which consisted of fistula-implanted rats, the sham group (n = 7) which consisted of sham-operated rats, and the control group (n = 7) which were not subjected to any surgical procedure. Four weeks after the fistula implantation surgery, we compared the blood biochemical indices, the microflora composition and the short-chain fatty acids (SCFA) concentration in cecal contents of fistula-implanted rats with those of sham-operated and control rats. The blood albumin concentration of the fistula group was significantly lower than that of the sham group and the control group, and the hematocrit value of the fistula group was significantly lower than that of the control group, but there were no significant differences in the SCFA concentration and the microflora composition among these three groups. In conclusion, it was considered that the fistula-implanted rats are useful for taking cecal contents and determining the microflora composition and the metabolites concentration at any time, without disturbing the physiological functions of the intestinal tract.

Animals↗

PubMed1999

Impairment of glucose tolerance in normal adults following a lowered carbohydrate intake.

Some normal people are falsely classified as having impaired glucose tolerance (IGT) if they are given an oral glucose tolerance test (OGTT) when their last meal contained very few carbohydrates. In this study, the duration of carbohydrate restriction was extended to one and three days and the relationship between the carbohydrate restriction and the glucose tolerance after an OGTT was examined. Two different groups of normal subjects were placed on high-carbohydrate (80% carbohydrates) and low-carbohydrate (10%) diets before an OGTT; one group for one day and the other for 3 days. None of the subjects showed impairment of glucose tolerance when placed on the high-carbohydrate regimens. In contrast, 3 of 12 subjects and 2 of 8 subjects placed on the low-carbohydrate diets for 1 and 3 days, respectively, were classified as having IGT. The impairment of glucose tolerance was invariably accompanied by an increase in the fasting plasma free fatty acid level. The longer the period of carbohydrate restriction, the severer was the glucose tolerance impairment. However, the number of subjects who were classified as having IGT did not depend on the duration of carbohydrate restriction. The impairment of glucose tolerance after carbohydrate restriction may be associated with the Randle effect, which is the activation of the glucose-free fatty acid cycle.

Adult↗

PubMed1999

A case of an electrical burn in the oral cavity of an adult.

Electrical burns in the oral cavity account for 2.2% of all electrical burns and only 0.12% of all burns; thus, the incidence of electrical burns in the oral cavity is relatively low. As this type of injury occurs in the oral cavity when an individual sucks or chews on a live electrical wire, extension cord, plug, or outlet, most cases occur in toddlers or preschool children, and adult cases are extremely rare. Here we describe a case of an electrical burn in a 56-year-old man who accidentally bit the electric wire of a cleaner while carrying out repairs. Conservative treatment, without surgery, was performed. Two years after the injury, a slight scar and a small tongue deformity remain, but no functional disturbance has been observed.

Burns, Electric↗

PubMed1999

So-called simple bone cyst of the jaw: a family of pseudocysts of diverse nature and etiology.

The nature and etiology of so-called simple bone cyst (SBC) are still a subject of debate. Our comprehensive review of the literature suggests that SBC, which appears histologically to be a single entity, has different natures and etiologies, resulting in divergent clinical features. In addition, an interesting case of mandibular SBC in an 11-year-old girl is presented with details of radiographic changes over a 7-year period. Fully documented patient records revealed that this lesion originated in the apical area of the first molar and took about 4 years to develop into a clinically evident bony expansion.

Child, Preschool↗

PubMed1999

cAMP enhances insulin secretion by an action on the ATP-sensitive K+ channel-independent pathway of glucose signaling in rat pancreatic islets.

Cyclic AMP potentiates glucose-stimulated insulin release by actions predominantly at a site, or sites, distal to the elevation of the cytosolic free Ca2+ concentration ([Ca2+]i). Glucose also acts at a site, or sites, distal to the elevation of [Ca2+]i via the ATP-sensitive K+ channel (K+ATP channel)-independent signaling pathway. Accordingly, using rat pancreatic islets, we studied the location of the action of cAMP and its interaction with the glucose pathway. Forskolin, an activator of adenylyl cyclase, raised intracellular cAMP levels and enhanced KCl-induced (Ca2+ -stimulated) insulin release in the presence, but not in the absence, of glucose. Thus, cAMP has no direct effect on Ca2+ -stimulated insulin release. The interaction between cAMP and glucose occurs at a step distal to the elevation of [Ca2+]i because forskolin enhancement of KCl-induced insulin release, in the presence of glucose, was demonstrated in the islets treated with diazoxide, a K+ATP channel opener. The enhancement of insulin release was not associated with any increase in [Ca2+]i. Furthermore, the interaction between cAMP and glucose was unequivocally observed even under stringent Ca2+ -free conditions, indicating the Ca2+ -independent action of cAMP. This action of cAMP is physiologically relevant, because not only forskolin but also glucagon-like peptide 1, glucose-dependent insulinotropic polypeptide, and pituitary adenylyl cyclase activating polypeptide exerted similar actions. In conclusion, the cAMP/protein kinase A pathway has no direct effect on Ca2+ -stimulated insulin exocytosis. Rather, it strongly potentiates insulin release by increasing the effectiveness of the K+ATP channel-independent action of glucose.

Adenosine Triphosphate↗

PubMed1999

Augmentation of Ca2+-stimulated insulin release by glucose and long-chain fatty acids in rat pancreatic islets: free fatty acids mimic ATP-sensitive K+ channel-independent insulinotropic action of glucose.

Glucose augments Ca2+-stimulated insulin release from the pancreatic beta-cell in an ATP-sensitive K+ channel (K(ATP) channel)-independent manner. In studying the mechanisms underlying this action, we used rat pancreatic islets and examined the effects of exogenous free fatty acids (FFAs), which are precursors of long-chain acyl-CoA (LC-CoA), on KCl-induced Ca2+-stimulated insulin release. Myristate, palmitate, and stearate augmented insulin release induced by 50 mmol/l KCl in the presence of 2.8 mmol/l glucose. Added acutely, their potency was weak compared with that of glucose-induced augmentation. The FFA-induced augmentation became much greater, however, when islets were preincubated with FFAs under stringent Ca2+-free conditions (with 1 mmol/l EGTA) before the KCl stimulation. Under these conditions, 16.7 mmol/l glucose augmented 13-fold insulin release induced by 50 mmol/l KCl, whereas palmitate or myristate (both at a free concentration of 10 micromol/l) produced 5.8- and 5.2-fold augmentations. Effects of FFAs and glucose were concentration-dependent. The temporal profiles of augmentation induced by 11.1 mmol/l glucose and 10 micromol/l palmitate were similar. Glucose and palmitate caused almost identical augmentation patterns for the initial 10 min of stimulation; subsequently, glucose augmentation was better sustained than palmitate augmentation. This suggests the existence of a longer-term glucose-specific signaling moiety that cannot be mimicked by FFAs. Our results provide direct evidence that FFAs can mimic the K(ATP) channel-independent action of glucose. Taking these results together with previous results, we conclude that glucose augments Ca2+-stimulated insulin release, at least in part, by increasing malonyl-CoA and cytosolic LC-CoA. However, one or more other glucose-specific signaling molecules are required for the full expression of augmentation.

Adenosine Triphosphate↗

PubMed1999

[A preventive and therapeutic measures for upper gastrointestinal disorders occurred after successful eradication of Helicobacter pylori].

According to the increasing the eradication therapy of Helicobacter pylori, endoscopists should pay an attention to a newly occurrence of upper gastrointestinal disorders after therapy. Most cases with gastric and duodenal erosion were asymptomatic and temporary that therapeutic approach are unnecessary. Some cases of gastro-esophageal reflux disease (GERD) required medication for a long period. About 2/3 of the cases basically had hiatal hernia. We have to pay an attention to the occurrence of GERD, when patient have hernia. The recurrence of peptic ulcer were seen in special condition such as use of nonsteroidal anti-inflammatory drugs, mental stress, or coexistence of other disease. It is important to get fully informed consent from all patients before eradication therapy including these unsatisfactory results.

Adult↗

PubMed1999

[Mapping-guided focal cryoablation and endoaneurysmorrhaphy for a case of ischemic ventricular tachycardia with left ventricular aneurysm].

A 74-year-old woman admitted with exertional dyspnea. Echocardiography revealed the giant left ventricular aneurysm. In the hospital course, she fell into sustained monomorphic ventricular tachycardia. Coronary angiogram showed complete obstruction of the LAD. Left ventricular ejection fraction was 20%. The origin of tachycardia seems to be at infero-apicallateral area of LV by electrophysiology study. Because of the failure of RF energy ablation, we planned mapping-guided cryoablation, CABG and endoaneurysmorrhaphy. To prevent air embolism and myocardial ischemic damage for long aortic cross clamp, intraoperative endocardial mapping was carried out on beating heart due to continuous normothermic coronary blood perfusion (300 ml/min) from the aortic root cannula under aortic clamping. Cold crystalloid cardioplegia changed into the root cannula after EPS, focal cryoablation (-100 degrees C) was performed 3 times on cardiac arrest. Sustained VT was not inducible in the following study. CABG and endoaneurysmorrhaphy was performed on repeated cardiac arrest during single aortic clamp. Postoperative course was uneventful, and she discharged 8 weeks after the operation.

Aged↗

PubMed1999

Epitope analysis of a prostate-specific antigen (PSA) C-terminal-specific monoclonal antibody and new aspects for the discrepancy between equimolar and skewed PSA assays.

BACKGROUND: Immunoassays to measure prostate-specific antigen (PSA) often give different values for the same patient samples, and the calibrators among commercial immunoassays are not interchangeable. We developed three novel assays to quantify the free and complexed forms of PSA in serum. METHODS: We synthesized 46 peptides, which encompassed the entire PSA molecule, and determined the interactions between selected monoclonal antibodies (MAbs) and those peptides or the intact PSA molecule. RESULTS: MAb PA313 did not cross-react with human glandular kallikrein (hK2), which has 78% amino acid homology to PSA. This MAb bound with KD = 40 nmol/L to the C-terminal peptide of PSA and distinguished between a synthetic peptide derived from PSA (PSA46A: NH2-C-R226KWIKDTIVANP237-COOH) that differed from one derived from hK2 (PSA46B: NH2-C-R226KWIKDTAANP237-COOH) by a single amino acid. Only the MAb combination of PA313/PA121 showed equimolar reactivity with PSA and with PSA complexed with alpha1-antichymotrypsin (PSA-ACT). The free form of PSA (F-PSA) was determined by MAbs PA313/FPA503, and the amount of complexed PSA (C-PSA) in PSA-ACT was determined by alphaACT/PA313. The total PSA (T-PSA) measured by either of the equimolar assays (PA313/PA121 or Tandem-R) was consistent with the sum of F-PSA and C-PSA. In contrast, T-PSA by a skewed assay (IMx) was higher than F-PSA + C-PSA when the ratio of F-PSA to T-PSA (F/T) was >0.15. T-PSA measured by IMx was nearly equal to F-PSA/0.55 + C-PSA. The coefficient 0.55 reflected different reactivities of the IMx assay with PSA-ACT and PSA. CONCLUSION: The discrepancy between the values measured by equimolar and skewed assays depends on the ratio of free to total PSA in the sample.

Amino Acid Sequence↗

PubMed1999

[Anesthesia experience of three patients with partial intramural coronary artery].

We experienced three patients with partial intramural coronary artery diagnosed preoperatively. We gave balanced anesthesia using narcotics and non-narcotic analgesics for non-cardiac surgery, administering phenylephrine against hypotension. The anesthetic course was relatively stable. According to the special pathophysiology of this disease, tachycardia and hypotension associated with anesthesia should be avoided, and special caution is needed when nitroglycerine is used due to its adverse effect on systolic narrowing of the coronary artery.

Aged↗

PubMed1999

[Typical thymic carcinoid tumor with multiple metastases diagnosed by pleural effusion cytology].

A 57-year-old man was referred and admitted to our hospital because of anterior mediastinal tumors and pericardial effusion. Although his condition had been diagnosed as thymic cancer by another hospital, a cytologic examination of pleural effusion specimens obtained a positive stain for chromogranin A, and yielded a diagnosis of thymic carcinoid tumor with multiple metastases. Despite irradiation and relief therapy, the patient died 8 months later. A histopathologic examination of the thymic tumor at autopsy revealed typical carcinoid patterns. The cytologic examination proved capable of accurately diagnosing the carcinoid tumor. Although such tumors are usually considered to have a good prognosis, unfavorable outcomes are also a possibility, as was demonstrated in this case.

Carcinoid Tumor↗

PubMed1999

[Persistent primitive olfactory artery: report of 5 cases].

Five cases of a persistent primitive olfactory artery are reported. The anomalous artery coursed anteromedially along the ipsilateral olfactory nerve and made a hairpin turn, supplying the circulation of the anterior cerebral artery. It was proposed that a primitive embryonic olfactory artery had remained as this artery. A cerebral aneurysm was located at the hairpin curve of the artery. Hemodynamic stress is considered to have an important role in aneurysm formation. Any aneurysm occurring at an artery should be considered for surgical treatment.

Aged↗

PubMed1999

[Multiple chemical sensitivities: case definition, etiology and relations to allergy, poisoning, psychogenic illness etc].

Multiple Chemical Sensitivities (MCS) have been defined as an acquired disorder characterized by recurrent symptoms, referable to multiple organ systems, occurring in response to demonstrable exposure to many chemically unrelated compounds at doses far below those established in the general population to cause harmful effects; no single widely accepted test of physiologic function can be shown to correlate with symptoms (Cullen MR, 1987). The etiology of MCS is hypothesized as a toxicant-induced loss of tolerance to multiple chemicals with subsequent manifestation of multiple-organ symptoms triggered by low-level exposure to such chemicals. The involvement of multiple organs might be attributed to a neurogenic switching mechanism. The final diagnosis of MCS is to rely on provocation of symptoms in a exposure chamber by a double-blind method. Relations of MCS to allergy, poisoning, psychogenic illness, chemical sensitivity, idiopathic environmental intolerances etc. are discussed in terms of case definition and etiology of these disorders.

Diagnosis, Differential↗

PubMed1999

[Changes in the fractal component of spectral analysis of heart rate variability and systolic blood pressure variability during the head-up tilt test].

Blood pressure and heart rate change are related to the level of physical activity, and are correlated with each other. Heart rate and blood pressure signals were investigated by coarse graining spectral analysis and changes in the harmonic and non-harmonic (fractal) power were examined during the head-up tilt test. Fourteen healthy subjects, 9 men and 5 women (mean age 30.4 +/- 1.0 years) completed the test protocol of 15 min supine rest followed by the head-up tilt (80 degrees) test. Heart rate was measured continuously with standard bipolar leads and electrocardiography. A finger cuff was placed on the left index finger for beat-by-beat recording of systolic blood pressure based on the continuous noninvasive method, and the impulse train was stored on a personal computer for spectral analysis. The harmonic component, the integrated powers in the low-frequency and high-frequency regions, and the fractal component were then calculated. The fractal component was plotted on a log power versus log frequency plane with spectral index beta estimated as the slope of the linear regression of this 1/f beta plot. RR-interval was significantly shorter during the head-up tilt position than in the supine rest position with a marked reduction in the high-frequency power. The ratio of fractal component for total power was increased and the slope beta of the 1/f beta relationship was significantly greater in the head-up tilt (1.61 +/- 0.05) than in the supine rest (0.92 +/- 0.07) position. Systolic blood pressure showed a significant increase during head-up tilt, and marked increases in high-frequency power and fractal power. However, both the ratio of fractal component for total power and the slope beta remained unchanged. Further studies are needed to clarify whether the slope beta is essentially stable or variable in some conditions.

Adult↗

PubMed1999

[A 13-week subchronic oral toxicity study of haematococcus color in F344 rats].

A 13-week oral repeated dose toxicity study of haematococcus color, a food additive mainly composed of astaxanthin, was conducted in male and female F344 rats. Rats were randomly divided into 4 groups each consisting of 10 males and 10 females and given CRF-1 powder diet containing 0%, 0.025%, 0.075%, and 0.25% haematococcus color, correspond to 0%, 0.5%, 1.5%, and 5% as the product. None of the animals died during the administration period. There were no exposure-related changes in body weight gain or food consumptions. Serum biochemical examinations showed dose-related increase in cholesterol, but the differences were slight and not defined as an adverse effect. No effects related to treatment were noted in hematological examinations and organ weights, and no abnormalities that could be ascribed to exposure to heamatococcus color were observed in histopathological examinations. In conclusion, ingestion of haematococcus color in the diet for 13 weeks does not cause any toxicological changes in F344 rats.

Animals↗

PubMed1999

[A combination of low-dose carboplatin (CBDCA) and radiation therapy in head and neck cancer patients--response and hematologenic toxicity].

A combination of carboplatin (CBDCA) and radiation therapy was performed in patients with head and neck cancer. The intravenous administration of CBDCA at a weekly dose of 100 mg/body was combined with external irradiation at a dose of 1.8 Gy/day x 5/week during the same therapy period. We evaluated the effects of this method not only on survival and neoadjuvant chemotherapy in patients with advanced cancer but also on local control and prevention of distant metastases in patients with early cancer. The subjects consisted of 31 patients with head and neck cancer who visited the Department of Otolaryngology, Showa University Hospital, Kanto Rosai Hospital and Yokohama Rosai Hospital between March 1993 and March 1995. Squamous cell carcinoma was found in all but one patient who had adenocarcinoma in the parotid gland. The patients were 27 males and 4 females ranging between 40 and 81 years of age (mean, 59 years). Twenty-six patients had previously untreated tumor, while 5 patients had recurrent tumor. The clinical stage was Stage I in 6, Stage II in 10, Stage III in 5 and Stage IV in 10 patients. The original site of cancer was the larynx in 9, hypopharynx in 6, nasopharynx in 6 and elsewhere in 10 patients. The combined therapy was repeated for 2-9 courses (mean, about 5 courses). The total dose of CBDCA was 500 mg on average with a maximum of 900 mg. The total effective rate of the combined therapy was 93.3% with 12 cases of complete response (CR) and 16 cases of partial response (PR). The effective rate in patients with previously untreated tumor was 92% because one patient showed a minor response (MR) and one patient showed no change (NC). The effective rate in patients with recurrent tumor was 100%. Concerning the clinical stage, all patients with Stage I-III disease showed CR or PR, while MR was found in 1, NC in 1 and progressive disease (PD) in 1 of 10 patients with Stage IV disease, resulting in an effective rate of 71.4%. There were no CRs in Stage IV patients. Therapy was terminated due to side effects in 2 patients. Excellent safety was confirmed by laboratory data.

Adult↗

PubMed1998

Structural analysis of Arabidopsis thaliana chromosome 5. VIII. Sequence features of the regions of 1,081,958 bp covered by seventeen physically assigned P1 and TAC clones.

A total of 17 Pl and TAC clones each representing an assigned region of chromosome 5 were isolated from P1 and TAC genomic libraries of Arabidopsis thaliana Columbia, and their nucleotide sequences were determined. The length of the clones sequenced in this study summed up to 1,081,958 bp. As we have previously reported the sequence of 9,072,622 bp by analysis of 125 P1 and TAC clones, the total length of the sequences of chromosome 5 determined so far is now 10,154,580 bp. The sequences were subjected to similarity search against protein and EST databases and analysis with computer programs for gene modeling. As a consequence, a total of 253 potential protein-coding genes with known or predicted functions were identified. The positions of exons which do not show apparent similarity to known genes were also assigned using computer programs for exon prediction. The average density of the genes identified in this study was 1 gene per 4277 bp. Introns were observed in 74% of the potential protein genes, and the average number per gene and the average length of the introns were 4.3 and 168 bp, respectively. The sequence data and gene information are available on the World Wide Web database KAOS (Kazusa Arabidopsis data Opening Site) at http://www.kazusa.or.jp/arabi/.

Arabidopsis↗

PubMed1998

Morphological transformation of liposomes caused by assembly of encapsulated tubulin and determination of shape by microtubule-associated proteins (MAPs).

To examine the role of cytoskeletons in cellular morphogenesis, we generated liposomes encapsulating tubulin, with or without microtubule-associated proteins (MAPs), and observed their transformation using dark-field microscopy. When tubulin was polymerized with MAPs in liposomes, liposomes were transformed into a "bipolar" shape with a central sphere and two tubular membrane protrusions that aligned in a straight line. On the other hand, when pure tubulin was polymerized in liposomes without MAPs, they initially transformed into a bipolar shape but subsequently re-transformed into a "monopolar" shape, i.e. a sphere with only one straight tubular portion. This re-transformation occurred in two ways: first, by shortening of one of the tubular portions due to microtubule disassembly; or second, by fluctuation of the central sphere toward one of the ends without shortening of the tube portion. MAPs prevented this re-transformation, and their role in stabilizing the shape of transformed liposomes was studied by the co-sedimentation method. The results show that MAPs, particularly MAP1 and MAP2, mediate binding between microtubules and the liposomal membrane. However, MAP2 by itself did not bind to liposomes, but was able to stabilize bipolar liposomes. This stabilization is caused not only by direct links between microtubules and liposomes, but also by prevention of Brownian motion of microtubules through an increase in friction.

Liposomes↗