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Biomedical subjects

A Umeda

Publications and source records attributed to A Umeda.

At least 37 records · Page 2Linked to original sources
PubMed1996

Epidemiologic application of pulsed-field gel electrophoresis to an outbreak of Campylobacter fetus meningitis in a neonatal intensive care unit.

An outbreak of nosocomial Campylobacter fetus meningitis occurred in a neonatal intensive care unit (NICU). Eight C. fetus strains were isolated from 4 infants with meningitis, the mother of the index patient and 2 infants who were asymptomatic intestinal carriers. The pulsed-field gel electrophoresis (PFGE) pattern with the restriction endonucleases Smal and Sall were found to be identical for the nosocomial C. fetus isolates, but the patterns were different from those of sporadic strains. These nosocomial strains were strongly suspected to be a single strain. The finding revealed that the index patient was infected by the mother, and that the outbreak developed from this patient by cross-infection. This is the first confirmed nosocomial C. fetus meningitis outbreak spread by cross-infection in a NICU.

Adult↗
PubMed1995

Reduction of tissue edema by microdialysis.

OBJECTIVE: This is the first report (to our knowledge) of the use of tissue microdialysis to reduce tissue edema. In this study, a hyperosmotic solution was perfused through microdialysis catheters, allowing direct treatment of interstitial edema by osmosis. DESIGN: First, the catheter and perfusate characteristics were tested in vitro. A physiologic, controlled trial was then performed, with two outcome variables: osmolarity of the effluent and tissue water content. SUBJECTS: Twenty male Sprague-Dawley rats. One rat was withdrawn. INTERVENTIONS: Tissue microdialysis catheters were implanted in the rats. The control side of the animals was not perfused. The experimental side was perfused for 9 hours. RESULTS: Osmolarity of the perfusate was reduced 16.5 mOsm after passing through the catheter, indicating that fluid was removed from the tissue. Tissue edema was reduced by an average 1.8 mL of fluid per 100 g of wet tissue. CONCLUSIONS: Tissue microdialysis removed tissue fluid and reduced edema. This treatment may have a beneficial effect on edematous tissues. Potential use and limitations of this therapeutic modality are discussed.

Animals↗
PubMed1995

Immunohistochemical analysis of rat and human respiratory cilia with anti-dynein antibody: comparison between normal cilia and pathological cilia in primary ciliary dyskinesia.

Wistar Imamichi rat and human respiratory cilia were examined with anti-dynein antibody (AD2), which is specific for sea urchin sperm flagellar dynein. AD2-labelled fresh-frozen normal rat and human cilia stained clearly by immunofluorescence and the peroxidase-antiperoxidase (PAP) technique. On immunoelectron microscopy, AD2 labelled the outer dynein arms of normal human cilia. Paraffin-embedded normal human cilia also stained by immunofluorescence, although not always clearly. Neither the cilia of WIC-Hyd male rats, an animal model of Kartagener's syndrome, nor human cilia from patients with primary ciliary dyskinesia (PCD) reacted positively by the immunofluorescence or PAP technique. Western blots of normal rat cilia yielded a single band of about 450 kDa. In conclusion, AD2 recognizes the outer arm dynein heavy chains of healthy cilia and may be useful in diagnosing and classifying PCD light microscopically especially when only paraffin-embedded specimens are available. This approach may be of potential use for better defining and classifying PCD.

Adolescent↗
PubMed1995

Typing of Staphylococcus aureus colonising human nasal carriers by pulsed-field gel electrophoresis.

Colonisation by Staphylococcus aureus in the nares of 120 outpatients and 63 healthy adults was studied for c. 2 years. Two states of carriage of S. aureus were confirmed: persistent carriage and persistent non-carriage. The states of carriage and non-carriage were quite stable and > 60% of the population of any of the study groups were stable non-carriers. The results of typing the strains isolated from the same individuals at different times with DNA fingerprinting by digestion with SmaI enzyme showed that all the stable carriers were persistently infected with the same strain and that changes in the strain seldom occurred.

Adult↗
PubMed1995

Typing of Staphylococcus epidermidis colonizing in human nares by pulsed-field gel electrophoresis.

From the nares of 11 healthy adults, 253 strains of coagulase negative staphylococcus were isolated and 88% of them were identified as Staphylococcus epidermidis using the API STAPH system. Chromosomal DNA fingerprinting of the isolated strains revealed that each person carried multiple types of S. epidermidis in his or her nares. The colonization of the strains was not stable; the types of the isolates changed in the first and the second examinations 5 months apart. The results contrasted with previous findings in which only one strain of S. aureus colonized persistently in the nares of healthy adults.

Adult↗
PubMed1995

Indirect hemagglutination assay for antibodies to Escherichia coli lipopolysaccharides O157, O111 and O26 in patients with hemolytic uremic syndrome.

We examined sera from 10 patients with hemolytic uremic syndrome (HUS) and 51 controls, with and without diarrhea, for antibodies to Escherichia coli lipopolysaccharides (LPS) O157, O111 and O26 using the indirect hemagglutination (IHA) assay. A significant rise (to a titer of > or = 2560) in IHA antibody to O157 LPS was detected in eight of the 10 HUS patients, to O111 in two patients, one of whom showed concomitantly an antibody rise to O157, but to O26 in no patients. The IHA titers fell rapidly after the acute phase of the illness. Of the control sera 15 (29.4%) non-specifically agglutinated uncoated sheep red blood cells (SRBC) at a titer of > or = 80, six (3.9%) at > or = 320 and the maximum was 640. In spite of the relatively low level of non-specific agglutination the IHA appeared to be a useful screening method to identify verotoxin-producing E. coli infections at the early stage of HUS because the titers were clearly higher than non-specific agglutination and the assay is easy to perform and gives results quickly. Artificial carriers are being considered for use in place of SRBC to diminish the non-specific hemagglutination.

Antibodies, Bacterial↗
PubMed1995

[Role of serotonin in impaired gas exchange during pulmonary embolism].

Although serotonin has been reported to play a substantial role in cardiopulmonary dysfunction, the quantitative effects of serotonin, released from activated platelets, on the development of alveolar flooding and on impaired gas exchange in pulmonary embolism have not been systematically investigated. To elucidate the effects of serotonin on pulmonary hemodynamics, accumulation of edema fluid in alveolar space, and impairment of gas exchange in acute pulmonary embolism, 20 mongrel dogs were given 0.4-0.6 g/kg of glass beads with a diameter of 100 microns, via the internal jugular vein. Before and after embolization, pulmonary hemodynamics, systemic hemodynamics, blood gases, and the distribution of ventilation-perfusion ratios (VA/Q) in the lung were measured, with and without a newly developed selective antagonist of the serotonin S2 receptor, DV-7028. VA/Q distribution was determined by applying the multiple inert gas elimination technique. After glass-bead embolization, the animals that did not receive DV-7028 showed significant increases in pulmonary arterial pressure and in extravascular lung water, widened alveolar-arterial O2 tension differences, and appreciable development of low VA/Q areas (0 < VA/Q < or = 0.1). These changes were prevented in the animals that received DV-7028. However, DV-7028 did not affect the formation of high VA/Q areas (VA/Q > 10). In conclusion, in acute canine pulmonary embolism serotonin not only induces pulmonary hypertension and pulmonary edema, but also worsens gas exchange through the formation of low VA/Q areas.

Acute Disease↗
PubMed1995

Stabilization of biological specimens by the use of plasma polymerized hydrocarbon film for imaging with an atomic force microscope.

An atomic force microscope makes imaging of biological molecules possible at high resolution. To this end all samples have to be fixed securely to a flat solid support so that they cannot be displaced by the scanning tip. We herein describe a new method to fix the biological samples to glass surfaces by depositing a thin layer of plasma polymerized methane gas in a high vacuum chamber. Such samples can thus be imaged repeatedly by an atomic force microscope without any loss of image quality.

Bacteriophage T4↗
PubMed1994

Cloning of feline p53 tumor-suppressor gene and its aberration in hematopoietic tumors.

Alterations of the p53 tumor-suppressor gene have been observed in a variety of human and mouse tumors. For investigation of the role of this gene in tumors of cats, feline p53 cDNA was molecularly cloned from a feline lymph-node cDNA library. The cloned cDNA (FF53) contained the whole open reading frame of p53 gene encoding 386 amino acids. The amino-acid sequence of the feline p53 gene showed 82.1% and 74.9% similarities with those of the human and mouse counterparts, respectively, and had structural characteristics in common with the p53 genes of several other species. Aberrations of the p53 gene were investigated by RT-PCR and single-strand conformation polymorphism analyses. Of 10 primary hematopoietic tumors and 3 lymphoma cell lines examined, one lymphoma and one lymphoma cell line had a point mutation of the p53 gene, resulting in single amino-acid substitutions.

Amino Acid Sequence↗
PubMed1994

High concentrations of conjugated bile acids inhibit bacterial growth of Clostridium perfringens and induce its extracellular cholylglycine hydrolase.

To investigate the effects of conjugated bile acid on bacterial growth and cholylglycine hydrolase activity, Clostridium perfringens from human feces was exposed to varying concentrations of taurine- or glycine-conjugated chenodeoxycholic acid. Extracellular enzyme activity was determined by deconjugation of radiolabeled taurocholic acid and viable cells were counted after anaerobic culture at 37 degrees C for 24 h. Viable cells were decreased with more than 1.0 mg of conjugated chenodeoxycholic acid per mL and there were no viable cells with 10.0 mg of bile acid per mL. Although total enzyme activity was decreased according to the bile acid concentration, enzyme activity per bacterium was increased between 1.0 and 4.0 mg/mL. There were no statistically significant differences between the types of conjugation. It was concluded that conjugated bile acids may exert inhibitory effect on bacterial growth and extracellular cholylglycine hydrolase activity in Clostridium perfringens. However, under the physiologic condition in the human intestine, conjugated bile acid might induce production of extracellular cholyglycine hydrolase per bacterium.

Amidohydrolases↗
PubMed1994

Characterisation of the external surfaces of Pseudomonas aeruginosa isolated from human blood and respiratory tract.

The surface structures of the cell envelopes of 16 clinical isolates of Pseudomonas aeruginosa were examined by electronmicroscopy with the new fixation technique of freeze-substitution. Two types of structures were observed among the organisms. In one group of strains, mostly isolated from blood, a dense fibrous layer c. 30 nm thick was found around the outer-membrane surface, whereas no such structure was observed in the other group of isolates, most of which were from sputum. Lipopolysaccharides extracted from the isolates with a dense fibrous layer were found by SDS-PAGE to have long O-polysaccharide chains, whereas strains without such a layer mostly had lipopolysaccharides that lacked high mol. wt. O-polysaccharide chains.

Bacteremia↗
PubMed1994

Serum inhibits penicillin-induced L-form growth in Staphylococcus aureus: a note of caution on the use of serum in cultivation of bacterial L-forms.

Heat-inactivated horse serum inhibited penicillin-induced L-form colony formation in Staphylococcus aureus when included in an osmotically stabilized culture medium. Most, perhaps all, L-form colonies that appeared with low frequencies on the serum-supplemented medium were of the penicillin-independent, stable type. This relationship must be taken into account when use of serum is considered for L-form cultivation.

Blood↗
PubMed1994

Assessment of an ultrathin bronchoscope that allows cytodiagnosis of small airways.

We developed a new type of bronchoscope (BF-2.7T) and cytology brush (BC-0.7T) that permit collection of pulmonary cells during direct observation of the small airways. This kind of cell collection has been previously impossible. With our cytology brush, 3.58 +/- 2.76 x 10(4) cells were collected from small airways. The rate of living cells was 33.13 +/- 3.61 percent from the small airways. Analysis of endoscopic findings and investigation of pulmonary cells are very important for elucidating the pathophysiologic state of the small airways. The use of the BF-2.7T allowed collection of cancer cells under direct endoscopic vision in all five patients with peripheral lung cancer. They also contribute to our understanding of the relationship between exogenous factors and cells that compose the lung, and will provide means for treatment and prevention of diseases.

Adenocarcinoma↗