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Biomedical subjects

K Seki

Publications and source records attributed to K Seki.

At least 109 records · Page 6Linked to original sources
PubMed1998

Immunohistochemical study of the c-kit expressing cells and connexin 43 in the guinea-pig digestive tract.

The distribution of the c-kit receptor expressing cells and gap junction protein, connexin (Cx) 43 in the guinea-pig stomach (antrum), small intestine (jejunum) and colon (ascending) was studied by immunohistochemistry. The anti-c-kit protein immunopositive cells were regularly observed in the myenteric region throughout all three organs. The immunopositive cells were also sparsely distributed in the circular muscle layer of both the stomach and the colon, but not in the small intestine. They were densely located in the regions of the deep muscular plexus (DMP) of the small intestine and submuscular plexus (SMP) of the colon. In contrast, strong immunoreactivity to anti-Cx 43 antibody was observed in almost the entire thickness of the circular muscle layer of the stomach and the small intestine, but not in the colon. Dense immunoreaction deposits were observed in the region of the DMP and SMP. However, only very weak immunoreactivity to anti-Cx 43 antibody was detected in the myenteric region of all three organs. These results suggest that the c-kit receptor expressing cells or interstitial cells of Cajal (ICC) in the myenteric region of the three organs, and in the SMP of the colon, are poorly coupled with the bulk of circular muscle tissue by gap junctions, while ICC in the DMP and in the circular muscle layer of the stomach couple well with the surrounding muscle tissue.

Animals↗
PubMed1998

What is line bisection in unilateral spatial neglect? Analysis of perceptual and motor aspects in line bisection tasks.

Three patients with unilateral spatial neglect could detect the difference of length between the right and left segments when a line had a transection mark. To examine the effect of response mode, the manual line bisection task and a new "line bisection task by fixation" were given to the patients. In tasks that used lines with no landmark, they showed apparent rightward errors. The results suggest that line bisection is not a task that examines the ability of patients with neglect to compare the right and left extents of a line. Where to fixate as the subjective midpoint may determine the rightward errors of bisection, whether manual response is used or not.

Aged↗
PubMed1998

Hypoproteinemia caused by tricuspid regurgitation: report of a case.

A case of tricuspid regurgitation (TR) complicated by severe hypoproteinemia is presented herein. A 68-year-old man who had undergone coronary artery bypass grafting (CABG) for postinfarction angina suffered repeated inferior myocardial infarction due to obstruction of the proximal right coronary artery, 3 years after which he developed systemic edema. Investigations revealed TR associated with hypoproteinemia; however, treatment consisting of aggressive diuretic therapy and albumin administration proved ineffective. The hypoproteinemia manifested as protein-losing enteropathy clinically, and the tricuspid valve was replaced to eliminate high venous pressure. The serum protein levels became normalized after the operation. Although TR is generally well tolerated in the absence of pulmonary hypertension, surgical management is recommended for patients with severe protein deficiency resistant to medical treatment.

Aged↗
PubMed1998

Pick's disease: selective occurrence of apolipoprotein E-immunoreactive Pick bodies in the limbic system.

We carried out immunohistochemical examination of apolipoprotein E (apoE) in brains from two patients with Pick's disease. In these cases 1 and 2, the APOE genotypes were epsilon 3/4 and epsilon 3/3, respectively. In both cases, numerous argyrophilic globular intraneuronal inclusions, Pick bodies (PBs), were distributed widely throughout the brain, and immunohistochemically were occasionally positive for apoE. Interestingly, such apoE-immunoreactive PBs were virtually restricted to neurons in the limbic system; in the dentate gyrus, the proportion of apoE-immunoreactive PBs relative to the total number of argyrophilic PBs was 5.0% in case 1 and 2.7% in case 2, whereas in the frontal and temporal neocortices it was less than 0.1% in both cases. Diffuse cytoplasmic immunoreactivity for apoE was found in only a few limbic system neurons without PBs in both cases. In conclusion, it is considered that apoE may not be positively involved in the process of PB formation and that the preferential distribution of apoE-immunoreactive PBs in the limbic system may reflect the presence of certain regional factors associated with the synthesis or metabolism of apoE in this particular system.

Aged↗
PubMed1998

Further observations on the gap-junction-rich cells in the deep muscular plexus of the rat small intestine.

Interstitial cells forming many large gap junctions in the region of the deep muscular plexus of the rat small intestine were studied by electron microscopy and by three-dimensional cell models reconstructed from serial ultrathin sections. Two different profiles of cells were observed. Cells of the first profile are characterized by an elongated cell shape and by less electron-dense cytoplasm, containing many mitochondria, well-developed Golgi apparatus and free ribosomes. They mainly connect with smooth muscle cells of the main circular layer. In a three-dimensional cell model, the total area of the gap junctions occupies 1.3% of the cell surface. Cells of the second profile are characterized by the frequent occurrence of slender cytoplasmic processes, higher electron-dense cytoplasm, containing mitochondria, Golgie apparatus and well-developed rough endoplasmic reticulum, and numerous caveolae on the cell membrane. In this cell model, gap junctions occupy 0.8% of the cell surface. The ratio of gap junctions with the same profile of cells to the total gap junction area is 37.7%, which is more than three times greater than the 9.9% in cells of the first profile. These cells were closely associated with nerve terminals. It is likely that these cells with different profiles constitute subtypes with each other and cooperate for regulation of intestinal motility via the transmission of nerve signals.

Animals↗
PubMed1998

Clinical significance of serum levels of CD44 variant exons 8-10 protein in colorectal cancer.

We examined serum levels of a CD44 splice variant that contained variant exons 8-10 (CD44v8-10) as a tumor marker in colorectal cancer patients. We performed enzyme-linked immunosorbent assays in 81 sera obtained from 71 colorectal cancer patients and 10 healthy controls. Serum CD44v8-10 levels were significantly higher in the colorectal cancer patients than in the healthy controls (0.209 +/- 0.098 versus 0.114 +/- 0.019 OD; P < 0.01). There was a close correlation between immunohistochemical expression and serum CD44v8-10 levels. Surgical resection of the tumors resulted in a reduction of serum CD44v8-10 levels. There was no significant correlation between serum CD44v8-10 level and serosal invasion or histologic type. However, a significant correlation was observed between serum CD44v8-10 level and lymphatic or venous invasion. In addition, serum CD44v8-10 levels were significantly higher in carcinomas associated with lymph node or liver metastasis than in those without metastasis. These findings suggest the usefulness of serum CD44v8-10 level in the prediction of colorectal cancer metastasis.

Biomarkers, Tumor↗
PubMed1998

Monomeric calcitonin in pregnant women and in cord blood.

OBJECTIVE: To determine whether monomeric calcitonin levels are increased during pregnancy. METHODS: Monomeric calcitonin was measured by immunoradiometric assay in maternal blood during pregnancy (n = 50) as well as in paired maternal and umbilical venous and arterial blood (n = 18) collected at term deliveries. RESULTS: Maternal monomeric calcitonin levels were not increased during pregnancy and puerperium compared with levels in nonpregnant women (power = .8). There was no significant difference between umbilical venous and arterial monomeric calcitonin levels (mean [+/- standard deviation] 18.56 +/- 8.37 versus 18.74 +/- 10.46 ng/L, respectively). Cord blood levels were much higher than were maternal blood levels (2.57 +/- 1.93 ng/L). CONCLUSION: Maternal monomeric calcitonin levels were not increased during pregnancy and puerperium compared to nonpregnant women, whereas cord blood levels were much higher than maternal blood levels.

Adult↗
PubMed1998

Effect of maternal hydration on oligohydramnios: a comparison of three volume expansion methods.

OBJECTIVE: To determine the effect of maternal hydration with intravenous (i.v.) isotonic fluid, i.v. hypotonic fluid, and oral water on amniotic fluid index (AFI) in women with oligohydramnios. METHODS: Patients with low AFI and gestational age over 35 weeks without maternal complications were randomized into four groups (2 L/2 h i.v. isotonic fluid, 2 L/2 h i.v. hypotonic fluid, 2 L/2 h oral water, control). Maternal plasma osmolality, AFI, hematocrit, and hemoglobin concentration were measured before and after hydration. RESULTS: Eighty-four patients (n=21/group) completed the study without any maternal adverse effects. The mean increase in AFI after hydration was significantly greater in the i.v. hypotonic and oral water groups (2.8+/-1.9, P < .001; 3.8 +/-1.9, P < .001, respectively), but not in the i.v. isotonic group (0.5+/-1.1), compared with the control group (0.5+/-1.1). Significant decreases in maternal hematocrit and hemoglobin concentration were found only after i.v. isotonic hydration (32.0+/-2.9 to 29.5+/-2.3, P < .001; 11.0+/-1.6 to 10.1+/-1.4, P < .001, respectively). Changes in maternal osmolality correlated with the changes in AFI in both the i.v. hypotonic group (r=.58, P < .001) and oral water group (r =.63, P < .001). CONCLUSION: Maternal hydration with either i.v. hypotonic fluid or oral water increases AFI in oligohydramnios. Maternal osmotic change rather than maternal volume expansion had a more direct impact on increasing amniotic fluid volume with short-term acute hydration.

Adult↗
PubMed1998

Relation between the size of motor units and the spectral characteristics of their action potentials. kazuseki@iname.com.

OBJECTIVE: The purpose of this study was to clarify the influence of the size of an individual motor unit on the spectral characteristics of its motor unit action potentials (MUAPs). METHODS: In 4 human subjects, we first averaged the isometric force and the surface EMG signals triggered by the intramuscularly recorded action potentials of each motor unit during voluntary isometric contraction. Then, we obtained averaged twitch contraction curves, averaged MUAPs derived from surface EMG signals (S-MUAPs), and the power spectrum of the S-MUAPs. Finally, we tested for correlations among these results in each subject. RESULTS: There was a positive correlation among the mean power frequency of the S-MUAPs, the maximal amplitude of the S-MUAPs, and the maximal twitch tension of their motor unit in each subject (r = 0.58-0.85; P < 0.05). CONCLUSIONS: Since the twitch tension and the amplitude of the S-MUAPs are well-known predictors of the size of motor units, we conclude that the spectral characteristics of the S-MUAPs reflect the size of the motor unit from which they originate.

Action Potentials↗
PubMed1998

Primary liposarcoma of the stomach: a case report and a review of the literature.

Primary liposarcoma of the stomach is rare and only seven cases have been described in the English literature. Here we report the eighth case, which occurred in a 68-year-old woman who presented with repeated tarry stools and hematemesis. Endoscopic examination revealed a large ulcerated submucosal mass at the gastric angle. The patient was treated by total gastrectomy. On microscopic examination, the tumor showed the features of a well differentiated sclerosing liposarcoma. Immunohistochemically, many spindle to stellate tumor cells were diffusely positive for vimentin and CD34. Positivity for S-100 protein was found in the adipocytic component, including lipoblasts, in addition to some spindle-shaped tumor cells. On ultrastructural examination, the spindle to stellate cells had features characteristic of fibroblasts. No recurrence or metastasis was seen during 13 months. Liposarcoma of the stomach has to be considered in the differential diagnosis with other submucosal lesions, such as gastric lipoma and gastrointestinal stromal tumor.

Aged↗
PubMed1998

Inhibitory effect of bacterial attachment on candidal growth due to adherence with mannose-sensitive pili.

A bacterial strain with affinity to Candida albicans was successfully obtained from a natural environment. An uncovered Petri dish containing a suspension of heat-killed C. albicans cells was allowed to stand in a laboratory for several days. Some bacteria which had adhered to the candidal cells were tested for their ability to agglutinate the cells. A bacterial strain, designated later as CAB-1, was found to agglutinate candidal cells through bridging by mannose-sensitive pili. CAB-1 showed similar bacteriological characteristics to those of Citrobacter freundii by ID test. The adherence of CAB-1 to candidal cell was precisely presented by scanning electron microscopy. The inhibitory effect of CAB-1 attachment to candidal cells on the growth of Candida was also preliminarily confirmed.

Agglutination↗
PubMed1998

Occurrence of coagulase serotype among Staphylococcus aureus strains isolated from healthy individuals--special reference to correlation with size of protein-A gene--.

One-hundred-and-nineteen strains of Staphylococcus aureus isolated from healthy individuals for 3 years between 1991 and 1993 were subjected to an investigation on the producibility of proteins including protein A, coagulase, enterotoxins and toxic-shock syndrome toxin-1. Especially, protein A was the center of our interest. Among these strains, 69, 43, 3 and 1 strains were found to have the protein-A gene containing 5, 4, 3 and 2 IgG-binding domains, respectively. On the other hand, only one strain was devoid of the protein-A gene. There were some differences in the profile of the coagulase serotype between the group with 4 IgG-binding domains and that with 5 IgG-binding domains. Differences in the profile of toxin production were also observed between the two groups.

Coagulase↗
PubMed1998

Epidemiologic typing of methicillin-resistant Staphylococcus aureus in neonate intensive care units using pulsed-field gel electrophoresis.

To elucidate the mode of dissemination of methicillin-resistant Staphylococcus aureus (MRSA) in neonate intensive care units (NICUs), a total of 223 isolates from 3 separate hospitals were investigated between 1994 and 1996 by a DNA fingerprinting technique with pulsed-field gel electrophoresis (PFGE). Exoprotein profiles of some strains were also examined using SDS-polyacrylamide gel-electrophoresis (SDS-PAGE) and the assessment of enzyme/toxin production such as coagulase, enterotoxin and TSST-1. Judging from the strain typing data from PFGE results and the epidemiological data, 2 different types of PFGE patterns (A and B) and their subtypes (A', A'' and B') were identified. The A type including A' and A'' (comprising approximately 95% of the isolates) was markedly dominant. Only 5% of the isolates belonged to type B and subtype B'. On the other hand, MRSA isolated from adult patients admitted to the same hospital showed many different PFGE patterns. The results strongly suggested that some strain(s) with specific PFGE pattern(s) is prevalent in NICUs. Furthermore, isolates which expressed the same PFGE pattern did not always express the same SDS-PAGE pattern. There were some isolates with different abilities to produce coagulase, enterotoxin C and toxic-shock syndrome toxin (TSST)-1, and the abilities had no relation with a particular type of PFGE pattern. Therefore, a combination of PFGE analysis and biochemical analyses of coagulase, enterotoxin C and TSST-1 may provide us with more detailed information for the epidemiological study of MRSA in NICUs.

Adult↗
PubMed1998

Different effects of fibronectin on the phagocytosis of Staphylococcus aureus and coagulase-negative staphylococci by murine peritoneal macrophages.

Fibronectin is known to be an important factor in colonization by Staphylococcus aureus of host tissues as well as other extracellular matrix proteins such as collagen and laminin. We investigated the effect of fibronectin on the phagocytosis of the S. aureus Cowan I strain by macrophages and of coagulase-negative staphylococci (CNS) strains for comparison. Fibronectin-reduced serum in place of normal serum lowered the phagocytic activity of the macrophages on the Cowan I strain. Purified fibronectin enhanced the phagocytic activity of the strain in a dose-dependent manner. On the other hand, fibronectin did not show any opsonic effect on the ingestion of CNS strains, though the binding of fibronectin occurred equally well in CNS strains and the Cowan I strain. Fibronectin-binding protein (FnBP), the specific fibronectin receptor on the surface on S. aureus, was detected in both the Cowan I strain and CNS strains. Polymerase chain reaction confirmed that not only the Cowan I strain, but also CNS strains possessed the FnBP gene. These results indicate that fibronectin shows an opsonic effect on the S. aureus, Cowan I strain but not on CNS strains, and suggest that the binding of fibronectin to FnBP is not sufficient for efficient phagocytosis of the staphylococci strains by macrophages.

Adhesins, Bacterial↗
PubMed1998

Adenosarcoma of the uterine cervix presenting as a cervical polyp.

A case of adenosarcoma arising from the uterine cervix of a 55-year-old female who complained of vaginal discharge is reported. A polyp, 6 x 2 x 1.5 cm in size, identified in the cervical canal was clinically diagnosed as benign cervical polyp and resected. Histologically, the polyp was composed of benign epithelial components and sarcomatous stroma wherein periglandular hypercellularity and some mitoses including atypical ones were noted. Immunohistochemically, stromal cells were positive for muscle-type actins, desmin and estrogen receptor. Adenosarcoma is a rare, biphasic tumor of the uterus and usually presents as a polypoid mass in the endometrial cavity. When they arise from the cervix, adenosarcomas may be confused with benign cervical polyps clinically and pathologically. As the former often recurs, microscopic differentiation is crucial for further treatment.

Actins↗
PubMed1998

An outbreak of hepatitis A in a day-care center: immunoprophylaxis with human immunoglobulin.

BACKGROUND: An outbreak of seven cases of hepatitis A (HA) occurred in a day-care center. Five of the cases were children attending the center, one was a nurse and one was the mother of a child. It is probable that the first case with HA was a male child infected by an unknown source. METHODS AND RESULTS: Human immunoglobulin (HIG) was administered to both children and staff at the center following which there were no new cases of infection among in-center contacts. However, a new case of HA among household contacts developed 3 weeks following the treatment of in-center contacts. CONCLUSIONS: The outbreak may have been prevented if the sibling (case 2) of the source case of infection (case 1) had been given HIG as soon as infection had been confirmed. Additionally, the data suggest that HIG for prevention of HA should be given not only to children but also to their parents.

Adult↗
PubMed1998

Comparison of chemotherapies with methotrexate, VP-16 and actinomycin-D in low-risk gestational trophoblastic disease. Remission rates and drug toxicities.

OBJECTIVE: To compare the efficiency and toxicity of four chemotherapeutic regimens in low-risk gestational trophoblastic disease. METHODS: Since 1974, 247 patients with low-risk gestational trophoblastic disease have been treated with 5-day intramuscular methotrexate (MTX) (conventional MTX), 5-day intravenous drip infusion of VP-16, 5-day intravenous actinomycin-D (Act-D) or 8-day alternating intramuscular MTX-folic acid (MTX-CF) at Chiba University School of Medicine. We compared the primary remission rate, the response of human chorionic gonadotropin and the prevalence of drug toxicities in these 4 regimens. RESULTS: The primary remission rate was 73.6% in the conventional MTX regimen, 90.1% in VP-16, 84.0% in Act-D, and 60.0% in MTX-CF. The primary remission rate was significantly higher in the VP-16 and Act-D regimens than in the conventional MTX and MTX-CF regimens. The response rate was significantly higher in the VP-16 regimen than in the other 3 regimens. The drug toxicity with VP-16 and Act-D was less than that with conventional MTX and MTX-CF regimens. CONCLUSIONS: The VP-16 regimen was highly effective and less toxic for gestational trophoblastic disease compared with other chemotherapeutic regimens.

Antibiotics, Antineoplastic↗