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Biomedical subjects

H Kawakami

Publications and source records attributed to H Kawakami.

At least 163 records · Page 9Linked to original sources

Relation between postpacing T wave changes and myocardial scintigraphic characteristics in patients with ventricular demand pacemaker.

The aim of this study was to elucidate the cause of T wave changes after ventricular pacing using thallium 201 single photon emission computed tomography (Tl-SPECT). Tl-SPECT was performed in 20 patients with sick sinus syndrome who had negative T wave after ventricular pacing and had had a ventricular demand pacemaker (VVI) implanted. Patients who have stenotic coronary arteries were excluded from the study. From the analysis of Tl-SPECT, extent score was calculated as the ischemic region. Data in patients with SSS were compared with those in 20 normal controls (NC). Thallium perfusion defects in patients with VVI were observed and distributed mainly in apex and inferior regions on the polar map. The extent score in patients with VVI was significantly higher than that in NC (56.4 +/- 21.6% vs 3.2 +/- 6.4%, P < 0.01). The washout rate of thallium 201 in the defect area was significantly lower in patients with VVI than in NC (27.4 +/- 10.2% vs 46.8 +/- 12.3%, P < 0.01). These results suggest that T wave changes after ventricular pacing are closely related to myocardial ischemia.

Aged↗

Effects of dietary nucleotides on lipid metabolism and learning ability of rats.

To investigate the effects of dietary nucleotides on lipid metabolism and learning ability, male Sprague-Dawley rats were fed with a nucleotides-supplemented diet or a nucleotides-free diet for 5 weeks. The content of nucleotides in the diet was 1.0% and their composition resembled that in human milk. The content of phosphatidylcholine (PC) and the ratio of PC to phosphatidylethanolamine (PE) in the cerebral cortex of rats fed the nucleotides-supplemented diet were significantly higher than that of rats fed the nucleotides-free diet. However, there was no difference in the content of PC and the ratio of PC to PE in the liver between the two groups. The levels of docosahexaenoic acid (C22:6n-3) and arachidonic acid (C20:4n-6) in the cerebral PC fraction were higher in rats fed the nucleotides-supplemented diet. The learning ability of rats fed the nucleotides-supplemented diet, which was evaluated by the water-filled multiple T-maze test and passive avoidance test, was superior to the of rats fed the nucleotides-free diet. The results presented here suggest that dietary nucleotides may influence lipid metabolism of the cerebral cortex and contribute to the rise in learning ability of rats.

Animals↗

Inhibition of cholera toxin by human milk fractions and sialyllactose.

The effects of human milk fractions on clolera toxin B subunit binding to monosialoganglioside 1 (GM1) were investigated. Human milk, human defatted milk, whey, and a low-molecular-weight fraction of human milk inhibited the binding, but casein did not inhibit it. The inhibitory activity of whey from bovine-milk-based infant formula was less than that of whey from human milk. Differences in composition between human and bovine whey seemed to influence the extent of the inhibitory activity. Sialylated oligosaccharides were considered to be the possible components that inhibited cholera toxin. The effects of sialyllactose, a predominant sialylated component of human milk, on cholera toxin-induced diarrhea were investigated by the rabbit intestinal loop method. Sialyllactose inhibited the cholera toxin inducing fluid accumulation, although neither sialic acid nor lactose had an effect on it. The results suggest that sialyllactose is responsible for the inhibitory activity of milk on cholera toxin.

Animals↗

Inhibitory effects of milk gangliosides on the adhesion of Escherichia coli to human intestinal carcinoma cells.

The effects of milk gangliosides and their derivatives on the adhesion of enterotoxigenic and enteropathogenic Escherichia coli to Caco-2 cells, a human intestinal carcinoma cell line, were investigated. Human milk gangliosides inhibited the adhesion of enterotoxigenic E. coli to Caco-2 cells in the same proportion, regardless of the lactational stage, but bovine milk gangliosides were less effective. The most effective inhibitor was monosialoganglioside 1 (GM1); the adhesion rate of enterotoxigenic E. coli in the presence of GM1 was less than 20% of the positive control. The adhesion of E. coli was also depressed to 31.4% by monosialoganglioside 3 (GM3). However, the inhibitory effect of disialoganglioside 3 (GD3) was less than that of GM3. GD3 lactone, ceramide lactoside, and N-acetylneuraminic acid did not inhibit E. coli adhesion to Caco-2 cells. GM3 also inhibited the adhesion of enteropathogenic E. coli to Caco-2 cells. Thus, these results suggest that GM3 possibly behaves as a physiological component in the intestinal tract of infants to protect them against enteric infections.

Animals↗

Gastric myoelectrical activities in elderly human subjects--surface electrogastrographic observations.

To investigate the alteration of the gastric electrical activities by aging, we performed electrogastrography (EGG) on 13 asymptomatic young human subjects under 60 years old (the young group) and 12 subjects over 60 years (the elderly group). Surface EGG was recorded at fasting state for 30 minutes in each subject. We expressed the frequency distribution of surface EGG in each subject with the median value of frequency distribution (FMED) to represent the center of the electrical activities, and the interquartile range of frequency distribution (FIQR) as the indicator of regularity. FMED in the young group was 3.0: [2.9, 3.4] (median: [range]) cycles per minute (cpm), while it was 3.3: [3.0, 4.0] in the elderly group which showed statistically a significant difference between the groups (p = 0.01). FIQR in the young group was 0.5: [0.1, 1.8] and that in the elderly group was 0.55: [0.4, 1.7], which was not significantly different statistically. These data showed that aging increases the frequencies of the rhythm of surface EGG, without disturbing its regularity. This change may be a part of a spectrum of physiological changes accompanied with aging, and are unlikely to have clinico-pathological significance.

Adult↗

Immunocytochemical localization of estrogen and progesterone receptors (ER & PgR) in breast cancer.

The localization of estrogen receptors (ER) and progesterone receptors (PgR) in human breast cancer was examined light and electron microscopically by using specific monoclonal antibodies. Among the breast cancer patients, ER-positive (ER[+]) cases were shown by enzyme immunoassay (EIA) to account for 58.9% (63/107), and 63.5% of these cases were women in the postmenopausal state. The PgR-positive (PgR[+]) rate was 50.5% (54/107), with 44.4% of these positive cases being postmenopausal women. The rates of ER(+) and PgR(+), ER negative (ER[-]) and PgR negative (PgR[-]), and ER(+) and PgR(-) cases were 43.9% (47/107), 34.6% (37/107) and 15.0% (16/107), respectively. Although ER(-) and PgR(+) cases were in few number, they were found (6.5%, 7/107). These results correlated well with those obtained by the immunocytochemical method. In either case, i.e anti-ER or anti-PgR reaction, positive nuclei and negative nuclei were found intermingled with each other in a given visual field. In electron microscopy, both anti-ER and anti-PgR antibodies bound to sites in the euchromatin area of the nucleus.

Antibodies, Monoclonal↗

Preoperative localization of brain lesions by magnetic resonance imaging with a marking device. Technical note.

A new technique for preoperative localization of brain lesions using magnetic resonance imaging and a marking device is described. The projection of lesions, especially superficial brain tumors, is demonstrated on the scalp, with an acceptable tolerance for open procedures. This simple and inexpensive method, which was use in a group of 34 patients, can assist surgeons in planning an operative approach to intracranial lesions.

Brain↗

[Effect of horizontal lithotomy position on spread of hyperbaric dibucaine spinal anesthesia].

We have studied the effect of horizontal lithotomy position on the spread of hyperbaric dibucaine spinal anesthesia. In three groups of 20 patients, 7.2 mg of hyperbaric dibucaine was injected intrathecally in the lateral decubitus position. In group supine, the patients were kept in supine horizontal position in which patient's legs and thighs were extended throughout the operation. In group lithotomy A, immediately after the spinal injection, the patients were placed into the lithotomy position. In group lithotomy B, after the spinal injection, the patients were placed immediately in the supine horizontal position for 15 min and then placed into the lithotomy position. There were no significant differences in height of sensory blockade among the three groups. The lithotomy position did not significantly affect the level of sensory blockade with hyperbaric dibucaine.

Adult↗

Immunohistochemical localization of the glucose transporter GLUT1 in choroid plexus papillomas.

Normal chroid plexus tissue and five choroid plexus papillomas were examined with antibody specific for the glucose transporter GLUT1, one isoform of facilitated-diffusion glucose transporters, using the avidin-biotin-peroxidase complex (ABC) technique. GLUT1 in normal choroid plexus was localized at the basolateral plasma membrane of almost all epithelial cells. In three of five tumors, GLUT1 immunoreactivity was observed. A positive reaction was demonstrated at the plasma membrane of tumor cells. The number of GLUT1-positive cells was, however, much smaller than that of the normal choroid plexus. Our results suggest that GLUT1 expression in the choroid plexus is restrained during the course of transformation and that choroid plexus papilloma is composed of various differentiation tumor cells.

Adolescent↗

[The clinical scoring system for predicting the risk of intraoperative and postoperative bronchospasm].

Patients with bronchial asthma (BA) are usually considered to have a high risk of developing bronchospasm (BS) during anesthesia. Our clinical scoring system for preoperative assessment in BA patients was used to predict the risk of intraoperative and postoperative BS. Thirty two patients with a history of BA were studied retrospectively, assessing preoperatively with our clinical scoring system; Bronchial Asthma Risk Index Score (BARIS). BARIS was composed of a total of ten items. Five of them were scored before inhalation of bronchodilators and remaining five items were scored after the inhalation. Each item was scored by 0, 1, or 2. Four of 32 patients developed BS peroperatively (BS group). Twenty eight patients developed no BS peroperatively (control group). The total scores of pre-inhalation five items were 4.8 +/- 1.9 in BS group and 2.0 +/- 1.3 in control group, and the total scores of post-inhalation five items were 4.0 +/- 1.4 in BS group and 1.3 +/- 1.0 in control group. There were significant differences between the two groups (P < 0.05, Mann-Whitney U-test). We conclude that BARIS is useful in evaluating the risk of peroperative bronchospasm in patients with a history of bronchial asthma.

Aged↗

Personality deviation and gastric motility in patients with functional dyspepsia.

We studied gastric motor functions by scintigraphic gastric emptying analysis and surface electrogastrography (EGG), and personality trait deviation in patients with functional dyspepsia. Delayed gastric emptying was observed in 17/35 patients and reduced normal EGG activity in 22/35 functional dyspepsia patients. There was a highly significant negative correlation between the gastric retention rate (at 150 min) and the duration of normal EGG waves. Abnormally high T scores on the Minnesota Multiphasic Personality Inventory (MMPI) test (70 or above) were found in 14/21 patients. Hypochondriasis (Hs) and conversion hysteria (Hy) were the most common abnormal findings. Ninety percent of functional dyspepsia patients (19/21) had either gastric dysmotility and/or psychological deviation. Although there was no significant correlation between gastric dysmotility and deviation in personality traits in functional dyspepsia patients, these data suggest that brain-gut interactions may play an important role in the symptoms of functional dyspepsia.

Adolescent↗

Real-time beam monitoring in dynamic conformation therapy.

PURPOSE: Although portal imaging is a promising method of verification during static multiport irradiation, it cannot be applied directly to dynamic irradiation such as rotational conformation with multileaf collimator movement. A real-time beam monitoring system based on megavoltage computed tomography scanning has been developed to establish a verification method for the rotational conformation technique. METHODS AND MATERIALS: Exit beam through the patient is extracted by the same detector unit as used for megavoltage scanning during the actual treatment. Beam edge is defined as the 50% level of the maximum dose of the detector array. Megavoltage computed tomography is done after patient setup and just prior to the actual irradiation. Detected beam pathways are overlaid on this image approximately every 1 s. Therapists can monitor correlation between the target and actual beam pathways on a real-time computer display. RESULTS: The accuracy of field edge detection has been proven to be less than 2 mm from various measurements. Real-time monitoring is more useful in rotational conformation than in static multiport irradiation due to dynamic movement of the collimator. Field errors were identified in two of 54 sessions using this method. CONCLUSIONS: Although several limitations remain to be solved, the method presented is a useful tool for treatment verification of high accuracy radiation therapy, particularly rotational conformation irradiation.

Brain Neoplasms↗

Ciliary neurotrophic factor induced-increase in beta-amyloid precursor protein mRNA in rat C6 glioma cells.

The effect of ciliary neurotrophic factor (CNTF) on beta-amyloid precursor protein (APP) gene expression was investigated in cultured rat C6 glioma cells and human SH-SY5Y neuroblastoma cells. CNTF increased APP mRNA abundance in C6 glioma cells in a dose-dependent manner, with an approximately 3-fold increase in maximum observed after 24 h with a concentration of 1 ng/ml. However, no significant differences in the splicing pattern of the three major isoforms of APP mRNA were apparent between control and CNTF-treated C6 glioma cells. CNTF had no effect on APP mRNA abundance in SH-SY5Y neuroblastoma cells. These findings suggest that CNTF can modulate APP mRNA expression and might affect amyloidogenesis in Alzheimer's disease.

Amyloid beta-Protein Precursor↗

Cloning and expression of a human glutamate transporter.

A complementary DNA clone was isolated from human brain that encodes a glutamate transporter. Injection of RNA transcribed from this cDNA into Xenopus oocytes resulted in expression of a transport activity with a high affinity for glutamate (Km = 78.4 microM) and a dependency on external Na+. The cDNA sequence predicts a protein of 542 amino acids that is highly homologous to the congeneric proteins from rat and mouse brains. RNA blotting analyses revealed the expression both in the brain and in peripheral tissues.

Amino Acid Sequence↗

Expression of Lewis(x) sugar structure in the liver metastasis of mouse colon carcinoma (colon 26) cells.

Immunohistochemical aspects of the process of experimentally induced metastasis were examined by light and electron microscopy employing a series of labeled carbohydrate-specific monoclonal antibodies as probes. Liver metastasis was induced by injecting mouse colon carcinoma cell (colon 26) into the spleen of Balb/c mice. Labeled anti-Lewis(x) (Le(x)) antibody stained the metastasized colon 26 cells strongly compared with the heterogeneous and faint staining in non-metastasized tumor foci in the spleen or in the subcutaneous space. Other antibodies having specificities for Lewis-related antigens other than Le(x), e.g. those against Le(y), Le(a), Le(b), sialyl Le(x) and sialyl Le(a), did not show any differences in binding between metastasized cells and non-metastasized tumor foci. Immunoelectron microscopy revealed the expression of Le(x)-carbohydrate in the plasma membranes as well as in the intercellular spaces of metastasized colon 26 cells in the liver. Based on these results, it is likely that sugar chains containing the Le(x)-carbohydrate structure are involved in the interactions between colon 26 cells and hepatic cells during the process of liver metastasis.

Animals↗

CAG expansions in a novel gene for Machado-Joseph disease at chromosome 14q32.1.

We have identified a novel gene containing CAG repeats and mapped it to chromosome 14q32.1, the genetic locus for Machado-Joseph disease (MJD). In normal individuals the gene contains between 13 and 36 CAG repeats, whereas most of the clinically diagnosed patients and all of the affected members of a family with the clinical and pathological diagnosis of MJD show expansion of the repeat-number (from 68-79). Southern blot analyses and genomic cloning demonstrates the existence of related genes. These results raise the possibility that similar abnormalities in related genes may give rise to diseases similar to MJD.

Adult↗