Biomedical subjects

Y Yoshida

Publications and source records attributed to Y Yoshida.

At least 415 records · Page 23Linked to original sources

PubMed1998

A case of congenital mumps infection complicated with persistent pulmonary hypertension.

A low-birth-weight female baby was admitted with respiratory distress after birth. Her mother had been diagnosed with mumps 4 weeks and 5 days prior to delivery. Mumps IgM antibody was elevated in the neonate and mumps virus ribonucleic acid was detected in the umbilical cord blood by reverse transcription-polymerase chain reaction. The perinatal virus infection was complicated with persistent pulmonary hypertension of the newborn and pulmonary hemorrhage. Successful treatment included the use of high frequency oscillation ventilation together with the administration of artificial surfactant.

Antibodies, Viral↗

PubMed1998

Morphological study of the intrapharyngeal ganglia and ganglionic neurons in cats.

The distribution, number and nature of intrapharyngeal ganglia and their neurons in cats were examined by means of serial sections, histochemical and immunohistochemical methods. Six to eight large ganglia around the palatine tonsils and five to eight small ganglia in the laterodorsal wall of pharyngeal mucous membrane were observed. The intrapharyngeal ganglionic neuron (25-30 microns in diameter) totalled 600-800 and more than 80% of them were located around the palatine tonsils. The ganglionic neurons were acetylcholinesterase reaction positive. On immunohistochemistry, many choline acetyltransferase-immunoreactive and vasoactive intestinal polypeptide-immunoreactive neurons and a few tyrosine hydroxylase-immunoreactive nerve cells were found, but no calcitonin gene-related peptide-immunoreactive or substance P-immunoreactive neurons were recognized in the ganglion. The present findings indicate that intrapharyngeal ganglionic neurons are mainly parasympathetic and partially sympathetic in nature.

Acetylcholinesterase↗

PubMed1998

Morphological observation of laryngeal motoneurons by means of cholera toxin B subunit tracing technique.

Gross anatomical and histological studies and immunohistochemical demonstration of cholera toxin B subunit used as a retrograde tracer were performed to investigate distinct muscle fibre bundles (MFBs) in the feline intrinsic laryngeal muscles (ILMs) and to characterize the respective supplying motoneurons in the nucleus ambiguus (AM). Distinct bundles were observed in all ILMs except the lateral cricoarytenoid muscle. Motoneurons supplying MFBs related to phonation located more medially than others. Motoneuron size did not differ between distinct MFBs in the same muscle. Neurodendrites for the cricothyroid muscle (CT) and adductor motoneurons extended dorsomedially, ventrolaterally and ventromedially, while those for the posterior cricoarytenoid muscle (PCA) motoneurons stretched dorsomedially and ventrolaterally. We conclude that distinct MFBs in ILMs play different roles in laryngeal functions, and that corresponding motoneurons have their own specific visceroneural nature allowing regulation of complex laryngeal functions. To receive information from the central nervous system, laryngeal motoneuron dendrites extended to regions locating respiratory, phonatory and swallowing neurons.

Animals↗

PubMed1998

Parvalbumin distribution in the musculature of the pharyngo-oesophageal segment.

The composition and size of muscle fibre types in the hyopharyngeus (HP), thyropharyngeus (TP), cricopharyngeus (CP) and cervical oesophageal muscle (CE) from 6 normal adult cats were investigated using parvalbumin (PA) immunohistochemistry. Fibre types I, IIA and IIB were identified in all muscles. HP and TP revealed predominance of type II fibres (74.8% and 75.2%, respectively), whilst CP and CE showed predominance of type I fibres (72.6% and 82.2%, respectively). The mean diameter of narrow fibres was greater in type II (23.9 microm) than in type I fibres (21.7 microm). The results seem to reflect the physiological features of each muscle, i.e. short rapid contractions of HP and TP, sustained contraction of CP and slow peristaltic movements of CE.

Animals↗

PubMed1998

CYP51-like gene of Mycobacterium tuberculosis actually encodes a P450 similar to eukaryotic CYP51.

A CYP51-like gene (Z80226) of Mycobacterium tuberculosis was expressed in Escherichia coli. The product exhibited absorption spectra characteristic of P450. The expressed P450 formed a stoichiometric complex with ketoconazole, one of the specific ligands of CYP51. These findings indicate that the CYP51-like gene of M. tuberculosis actually encodes a P450 having active-site environments similar to those of CYP51, confirming the predicted orthologous nature of this gene to eukaryotic CYP51. Although eukaryotic CYP51s are membrane-binding proteins, the expressed product was accumulated only in the soluble fraction of the host cells.

Amino Acid Sequence↗

PubMed1998

Pancreatic diabetes in Japan.

Pancreatic diabetes is usually a complication of other pancreatic disorders. Diabetes was a complication in 55.5% of 2,774 patients with chronic pancreatitis (CP) in Japan. More than half of alcoholic patients with CP in our clinic showed diabetes, and approximately 50% of those patients with diabetes were treated with insulin injections. On the other hand, cases of nonalcoholic CP showed mild endocrine dysfunction in terms of diabetic frequency and severity. Epidemiologic studies suggest that diabetes resulting from chronic pancreatitis accounts for <0.8% of all Japanese patients with diabetes. In patients with CP, B-cell dysfunction occurred first, followed by disturbances in A-cell function. Decreased insulin secretion during postprandial periods plays an important role in pancreatic diabetes. The fasting level of blood glucose is not useful for the diagnosis of the early stage of pancreatic diabetes. The glucose-tolerance test should be performed to diagnose early-stage diabetes in patients with CP with normal fasting blood glucose levels. For control of blood glucose in diabetic patients with CP, multiple injections of short-acting effective insulin before the meal are necessary. The incidence of long-term diabetic complications, diabetic retinopathy, nephropathy and neuropathy, in patients with CP with diabetes are not less than those in patients with primary diabetes.

Chronic Disease↗

PubMed1998

Endoscopic diagnosis of lower intestinal lesions of leukaemia and malignant lymphoma.

There have been only a few endoscopic studies with respect to lower intestinal lesions of leukaemia and malignant lymphoma, although there have been many autopsy studies of these lesions. The aim of this study was to clarify these lesions using endoscopy. Colonoscopy was performed on 11 of 341 patients with leukaemia and on 32 of 105 patients with malignant lymphoma for frequent diarrhoea, anal bleeding or abnormal findings on barium enema examination, between April 1984 and September 1994. In eight of the 11 patients with leukaemia on whom endoscopy was performed, nine lesions were found; aphthoid ulcers, small ulcers or large tumours due to leukaemic infiltration were found in five, and colorectal adenoma was found in only one patient. Antibiotic-associated haemorrhagic colitis or pseudomembranous colitis was found in one patient each. In 10 of the 32 patients with malignant lymphoma, 11 lesions were found. The following were found in one patient each: large lymphomatous tumours, a large lymphomatous ulcer, multiple small polypoid lesions, multiple lymphomatous polyposis; and colorectal cancer or adenoma in six patients. However, the autopsy findings in patients with both diseases were mostly pseudomembrane formation or ulcers due to fungal and/or bacterial infection. It is concluded that accurate endoscopic diagnosis of lower intestinal lesions in patients with leukaemia or malignant lymphoma is essential for staging and treatment of these diseases and for determining their prognosis. Most lesions in leukaemia are aphthoid and small ulcers are due to leukaemic infiltration or antibiotics; most lesions in malignant lymphoma are elevated lesions such as cancer, adenoma or lymphomatous lesions as determined by endoscopy. This is in contrast to pseudomembrane formation or ulcers due to fungal and/or bacterial infection which are detected at autopsy.

Adult↗

PubMed1998

Detection of Coxiella burnetii specific DNA in blood samples from Japanese patients with chronic nonspecific symptoms by nested polymerase chain reaction.

The nested polymerase chain reaction (PCR) was used for direct species-specific detection of Coxiella burnetii in blood samples from 52 patients with chronic nonspecific symptoms, but no diagnostic or treatment history of Q fever. All patients had been in ill-health with general fatigue, muscle and joint pain, headache, etc., for one to more than 10 years. Seventeen (33%) showed evidence of C. burnetii infection, based on amplification of 438-bp fragments specific to C. burnetii by nested PCR, and 94% of positive patients reported close contact with animals. In contrast, five (9.6%) of 52 samples from healthy adult controls and two (2.8%) of 70 cord blood samples were positive by nested PCR. These data suggest a high prevalence of infection among adult patients with long term, nonspecific complaints who live in close contact with animals and the possible existence of a chronic post-acute Q fever syndrome in Japan.

Adolescent↗

PubMed1998

[Evaluation of immunochromatography-based rapid detection kit for fecal Escherichia coli O157].

"Quix" is an immunochromatography-based direct detection kit for the E. coli O157 LPS antigen in the patient's stool. The present study was conducted to evaluate the efficacy of the kit for rapid diagnosis of enterohemorrhagic Escherichia coli (EHEC) O157 infection. Sensitivity of the kit was determined using a pure culture of a clinical isolate of E. coli O157. Analytical sensitivity was found to be 5 x 10(5) CFU/ml. When compared with the culture method using fecal samples of 64 patients and with bloody diarrhea, sensitivity and specificity were 95.0% (19/20) and 86.4% (38/44), respectively, and overall agreement to culture method was 89.1% (57/64). One patient was found positive by culture method while negative in the present method, where the sample contained a low number of the cells less than the detection limit. Four of the six patients with a negative result by culture method and positive in the present method, were confirmed E. coli O157 infection by positive IgM antibody response against the E. coli O157 LPS. The discrepancy between the two methods seemed to be attributable to antibiotic administration. In one patient, Salmonella urbana (O30(1)30(2)) was detected. The O30(1) antigen of this bacterium is well known to be identical to the E. coli O157 antigen. When the present method was compared with an ELISA-based E. coli O157 LPS antigen detection kit, sensitivity and specificity were 100% (11/11) and 82.1% (23/28), and overall agreement to ELISA method was 87.2% (34/39). From these findings, Quix is useful as a rapid diagnostic kit in the primary clinics, outpatient or bedside use. E. coli O157 LPS antigen in patient's fecal samples can be detected in about five minutes with this simple procedure. Early diagnosis using such a simple kit will largely contribute for the early treatment and prevention of severe complications of the E. coli O157 infection.

Antigens, Bacterial↗

PubMed1998

Identification of a genetic locus essential for serotype b-specific antigen synthesis in Actinobacillus actinomycetemcomitans.

A large gene cluster associated with the biosynthesis of the serotype-specific polysaccharide antigen (SPA) of Actinobacillus actinomycetemcomitans Y4 (serotype b) was cloned and characterized. Western blot analysis showed that Escherichia coli DH5alpha, containing a plasmid carrying this cluster, produced a polysaccharide which reacted with a monoclonal antibody directed against the SPA of A. actinomycetemcomitans Y4. High-performance liquid chromatography analysis indicated that the polysaccharide produced by an E. coli transformant, as well as A. actinomycetemcomitans Y4 SPA, was composed of rhamnose and fucose. Furthermore, using various derivatives of the plasmid, we demonstrated that the cloned 13-kb BssHII-BspHI fragment was indispensable for SPA synthesis in E. coli DH5alpha. The 24,909-bp nucleotide sequence, which included this fragment and its flanking regions, was determined. In the sequenced area, 24 open reading frames (ORFs) with the same orientation were found. Most of these were located sequentially within a short distance of each other. Many of the deduced amino acid sequences were similar to the gene products of the polysaccharide synthetic genes of other bacteria. The average G+C content (37.7%) of all 24 ORFs in the sequenced area was lower than that (45.6%) of the whole chromosome of A. actinomycetemcomitans Y4. It is noteworthy the average G+C content of the nine ORFs in the 8.5-kb central region of the 13-kb BssHII-BspHI fragment indispensable for SPA synthesis in E. coli was found to be especially low (27.0%).

Acetylglucosamine↗

PubMed1998

Gab1 acts as an adapter molecule linking the cytokine receptor gp130 to ERK mitogen-activated protein kinase.

Gab1 has structural similarities with Drosophila DOS (daughter of sevenless), which is a substrate of the protein tyrosine phosphatase Corkscrew. Both Gab1 and DOS have a pleckstrin homology domain and tyrosine residues, potential binding sites for various SH2 domain-containing adapter molecules when they are phosphorylated. We found that Gab1 was tyrosine phosphorylated in response to various cytokines, such as interleukin-6 (IL-6), IL-3, alpha interferon (IFN-alpha), and IFN-gamma. Upon the stimulation of IL-6 or IL-3, Gab1 was found to form a complex with phosphatidylinositol (PI)-3 kinase and SHP-2, a homolog of Corkscrew. Mutational analysis of gp130, the common subunit of IL-6 family cytokine receptors, revealed that neither tyrosine residues of gp130 nor its carboxy terminus was required for tyrosine phosphorylation of Gab1. Expression of Gab1 enhanced gp130-dependent mitogen-activated protein (MAP) kinase ERK2 activation. A mutation of tyrosine 759, the SHP-2 binding site of gp130, abrogated the interactions of Gab1 with SHP-2 and PI-3 kinase as well as ERK2 activation. Furthermore, ERK2 activation was inhibited by a dominant negative p85 PI-3 kinase, wortmannin, or a dominant negative Ras. These observations suggest that Gab1 acts as an adapter molecule in transmitting signals to ERK MAP kinase for the cytokine receptor gp130 and that SHP-2, PI-3 kinase, and Ras are involved in Gab1-mediated ERK activation.

Adaptor Proteins, Signal Transducing↗

PubMed1998

Optic neuritis and human T-lymphotropic virus type 1-associated myelopathy: a case report.

A 50-year-old woman with human T-lymphotropic virus type 1-associated myelopathy developed sudden loss of vision in her left eye. The patient had a relative afferent pupillary defect and a large central scotoma on visual field examination, but no abnormal findings were apparent upon slitlamp microscopy and funduscopic examination. A diagnosis of retrobulbar optic neuritis was made. We discuss the possible association of human T-lymphotropic virus type 1 infection.

Evoked Potentials, Visual↗

PubMed1998

A TEM study of two water-based adhesive systems bonded to dry and wet dentin.

To keep the exposed collagen scaffold penetrable to resin, it has been recommended that the conditioned dentin surface be maintained in a visibly moist condition, a clinical technique commonly referred to as wet bonding. In this study, resin-dentin interfaces produced with two water-based adhesive systems--OptiBond (OPTI, Kerr) and Scotchbond Multi-Purpose (SBMP, 3M)--were compared by transmission electron microscopy, following the application of either a dry- or a wet-bonding technique. The hypothesis advanced was that the ultramorphology of the hybrid layer would differ depending on which bonding method was applied. A morphologically well-organized hybrid layer of collagen fibrils intermingled with resin in tiny interfibrillar channels was consistently formed by the OPTI system. The SBMP system was found to produce a hybrid layer with a more variable ultrastructure, less distinctly outlined collagen fibrils, and a characteristic electron-dense phase located at its surface. No major differences in hybrid layer ultrastructure were observed when the two adhesive systems investigated were bonded to either dry or wet dentin. When the adhesives were dry-bonded, no ultrastructural evidence of collapsed demineralized collagen, incompletely or not at all infiltrated by resin, could be detected. In addition, when the two adhesives were bonded to wet dentin, no signs of overwetting phenomena, that would have indicated that water was ineffectively removed, were apparent. It has been hypothesized that the amount of water provided with the hydrophilic primer solution of either of the two adhesive systems investigated suffices to re-hydrate and re-expand the gently air-dried and collapsed collagen network. Further research should be directed to determine whether this hypothesized self-rewetting effect can be extrapolated to other adhesive systems that provide water-based primers.

Adhesives↗

PubMed1998

Induction of Ad4BP/SF-1, steroidogenic acute regulatory protein, and cytochrome P450scc enzyme system expression in newly established human granulosa cell lines.

We have established immortalized human granulosa cells by triple transfection of primary cells obtained from in vitro fertilization patients with SV40 DNA, Ha-ras oncogene, and a temperature sensitive (ts) mutant of the tumor suppressor gene p53 (p53val135). Forty-one clones were isolated, and their steroidogenic responses were analyzed. While all the cell lines proliferate rapidly and show only traces of progesterone production, upon stimulation with 50 microM of forskolin (FK), which elevates intracellular cAMP, they become steroidogenic as evidenced by progesterone production. The steroidogenic response of the cell lines was stable even after 20 generations and several cycles of freezing and thawing. A highly responsive cell line (HO-23) was further examined for characteristics of the steroidogenic response. Cells stimulated with FK and 8-Br-cAMP produced high levels of pregnenolone, progesterone, and 20alpha-hydroxy-4-pregnen-3-one (20alpha-OH-progesterone) comparable with amounts produced by highly differentiated primary human granulosa-luteal cells. Hydrocortisone and dexamethasone highly augment the cAMP-stimulated progesterone production, whereas testosterone and PRL enhanced cAMP-induced progesterone synthesis only moderately. Estradiol, insulin-like growth factor I, and insulin showed no significant effect on cAMP-induced steroidogenesis. The phorbol ester TPA, and basic fibroblast growth factor, dramatically suppress cAMP-induced production of progesterone, whereas bovine corneal endothelial cell ECM (BCE/ECM) enhanced cAMP-induced progesterone and antagonized basic fibroblast growth factor suppression of cAMP-induced steroidogenesis. Steroidogenic factor 1 (Ad4BP/SF-1) was expressed in control cells, and its expression was augmented by FK, whereas the steroidogenic acute regulatory protein showed low expression in the nonstimulated cells but was clearly elevated upon cAMP stimulation and was slightly decreased by TPA in cAMP-stimulated cells. Expression of the electron carrier adrenodoxin (ADX), which is a part of the cytochrome P450scc enzyme system, was very low in nonstimulated cells but was dramatically elevated in FK- and 8-Br-cAMP-stimulated cells, whereas no reduction of ADX was evident in cells costimulated with FK and TPA. Immunocytochemical studies revealed a weak staining of ADX in mitochondria of nonstimulated cells and intensive staining in highly clustered mitochondria of FK- or 8-Br-cAMP-stimulated cells. Only moderate reduction in ADX staining was evident in cells costimulated with FK and TPA. These unique cell lines can provide a useful model for the investigation of induced steroidogenesis in human granulosa cells.

Animals↗

PubMed1998

Effect of methylcarbonylmethyl 2(S)-[4-(4-guanidino-benzoyloxy)phenyl] propionate methanesulfonate (TT-S24) on experimental pancreatitis in rats.

The effect of methylcarbonylmethyl 2(S)-14-(4-guanidino-benzoyloxy) phenyl] propionate methanesulfonate (TT-S24) on experimental pancreatitis in rats was examined in comparison with that of camostat. TT-S24 showed a preventive effect on increases in plasma amylase activity and pancreatic weight induced by cerulein injection. TT-S24 also reduced an increase in plasma amylase activity induced by taurocholate. TT-S24 effectively prevented the mortality induced by an injection of a mixture of trypsin and taurocholate. TT-S24 showed no effect on an increase in amylase activity 6 h after duodenum ligation (closed duodenal loop pancreatitis), indicating that the drug had no effect on the initiation and propagation step of closed duodenal loop pancreatitis. On the other hand, TT-S24 reduced an increase in amylase activity 6 h after release of the duodenum ligation. TT-S24 showed anti-trypsin, anti-kallikrein, anti-thrombin and anti-plasmin activities. The effect of TT-S24 on some experimental pancreatitis models was nearly equal to or somewhat more potent in most instances to that of camostat. Therefore, TT-S24 should be useful in the clinical treatment of pancreatitis.

Amylases↗

PubMed1998

Expression of growth factor ligand and their receptor mRNAs in bovine ova during in vitro maturation and after fertilization in vitro.

We analyzed the expression of mRNAs for growth factor [epidermal growth factor (EGF), insulin-like growth factor-I (IGF-I), basic fibroblast growth factor (bFGF) and platelet-derived growth factor A chain (PDGF-A)] and their receptor (R) by reverse transcription-polymerase chain reaction in bovine ova during oocyte maturation in vitro (0-21 hr) and after fertilization in vitro (6-144 hr: zygotes to blastocysts). Transcripts for EGF were not found before fertilization. Transcripts for IGF-I were present in immature oocytes immediately after collection and in embryos from the 2-cell stage onward. Transcripts for bFGF were present in all stages of oocyte maturation and after fertilization up to the 16-cell stage. Transcripts for PDGF-A were present in all stages of oocyte maturation and after fertilization up to the 2-cell stage. Transcripts for ErbB3 (a member of the EGF-R subfamily), and bFGF-R were present in all stages of oocyte maturation, after fertilization up to the 2-cell stage, and the blastocyst stage. Transcripts for IGF-I-R and PDGF-Ralpha were present in all stages of oocyte maturation and embryo development. The results of this study showed that eight different messages for growth factor and their receptor were detectable in bovine ova during oocyte maturation and/or after fertilization in vitro and their expression patterns were the gene-specific rather than the developmental stage of bovine ova.

Animals↗

PubMed1998

Effect of methylcarbonylmethyl 2(S)-[4-(4-guanidinobenzoyloxy) phenyl] propionate methanesulfonate (TT-S24) on pancreatic secretion in rats.

The effect of methylcarbonylmethyl 2(S)-[4-(4-guanidinobenzoyloxy) phenyl] propionate methanesulfonate (TT-S24), a newly synthesized trypsin inhibitor, on exocrine pancreatic secretion was examined and compared with that of camostat in rats. Intraduodenal (i.d.) administration of TT-S24 and camostat resulted in an increase in volume, amylase concentration and amylase output of pancreatic juice. Although i.v. injection of TT-S24 and camostat (3 mg/kg) had no effect on the pancreatic juice volume, TT-S24 (i.v.) dose-dependently increased pancreatic juice volume under acetylcholine (10 micrograms/kg/min) infusion. In addition, the weight of pancreases from WBN rats was significantly increased by 28 day oral administration of TT-S24 (100 mg/kg) with a potency similar to that observed with camostat.

Acetylcholine↗

PubMed1998

Responses of trabecular and cortical bone turnover and bone mass and strength to bisphosphonate YH529 in ovariohysterectomized beagles with calcium restriction.

Thirty-six beagles, 18 months of age, underwent ovariohysterectomy (OHX) or a sham operation. Sham-operated animals were given a diet with standard calcium (1.4%) (group 1, n = 6) or a restricted calcium diet (0.14%) (group 2, n = 6). The OHX animals were given the restricted calcium diet and YH529 orally with respective daily doses of 0, 0.02, 0.1, and 0.5 mg/kg of body weight (groups 3-6, n = 6 each) for 12 months. At the end of this period, the lumbar bone mineral densities (BMDs) in groups 2 and 3 and the load values for group 3 were significantly smaller than those for group 1. The midfemur BMD did not differ among the groups. The urinary deoxypyridinoline (U-Dpy) and bone formation rates (BFR/BS, BFR/BV) in groups 2 and 3 and the osteonal BFR/BS and trabecular osteoclast number (Oc.N/BS) in group 3 were significantly larger than the respective values for group 1. However, these parameters did not significantly differ between groups 2 and 3. The serum osteocalcin (OC) level, wall thickness (W.Th), and mineral apposition rate values for group 3 were significantly larger than those for group 2. In group 2, the trabecular activation frequency (Ac.F) increased by 3.11 times, and the percent values of the number of labeled osteons (L-Ot.N/T-Ot.N, %) in the tibia by 3.28 times over those for group 1. In group 3, the Ac.F increased by 3.20 times and the number of labeled osteons by 3.77 times over those for group 1. In groups 4-6, the U-Dpy and Oc.N/BS values were smaller, but their OC levels did not significantly differ from the level for group 3. The lumbar BMD, the load, and W.Th were dose-dependently significantly larger than those for group 3. The Ac.F values were significantly smaller, and the respective value in groups 4-6 was 67.9, 25.5, and 10.2% of that in group 3. The BMDs of the midfemur in groups 4-6 were significantly larger than those in group 3, but the ultimate load values did not significantly differ. The L-Ot.N/T-Ot.N values were also significantly smaller, and the respective value in groups 4-6 was 82.0, 48.5, and 55.2% of that in group 3. The tibial endocortical and periosteal BFR/BSs did not differ significantly. These data demonstrate that the effects of OHX on bone mass and turnover were small in the beagles fed a restricted calcium diet. YH529 maintained the mass and strength of the lumbar bone by reducing the bone resorption. The cortical bone appeared to be less sensitive to the agent than the trabecular bone in this animal model.

Administration, Oral↗