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Biomedical subjects

Y Yoshikawa

Publications and source records attributed to Y Yoshikawa.

At least 253 records · Page 14Linked to original sources

Mixed connective tissue disease associated with lupus lymphadenitis.

We have encountered 2 patients with mixed connective tissue disease (MCTD) associated with lymphadenopathy at the outset. Biopsy specimens of enlarged lymph nodes showed massive necrotizing lesions with follicular hyperplasia, which are occasionally observed in the involved lymph nodes of patients with systemic lupus erythematosus (SLE) and called lupus lymphadenitis. Usually, the only histologic finding of an involved lymph node in MCTD is lymphoid hyperplasia. These are the 2nd and 3rd cases of MCTD associated with lupus lymphadenitis. Our cases suggest that histologic studies of the swollen lymph nodes are not helpful in distinguishing MCTD from SLE.

Biopsy↗

Complete nucleotide sequence of the phosphoprotein of the Yamagata-1 strain of a defective subacute sclerosing panencephalitis (SSPE) virus.

The complete nucleotide sequence of the phosphoprotein (P) gene of the Yamagata-1 strain of a defective subacute sclerosing panencephalitis (SSPE) virus was determined. Comparison with the P gene of the Edmonston strain of measles virus (MV) revealed 44 differences of which 23 nucleotides substitutions were identical with those revealed between other SSPE viruses and MV (Cattaneo et al. (1989) Virology 173, 415-425). The consensus sequence of the G insertion site was completely conserved, whereas mRNAs with one or three non-templated G residue insertions were found in addition to the mRNA of the exact genome copy. As a result of the frameshift downstream of the site of G insertion, the cysteine-rich V protein was predicted from the one G-inserted mRNA besides the P and C proteins predicted from the genome-copied mRNA.

Amino Acid Sequence↗

Liver regeneration following portacaval shunt in rats: 3',5'-cyclic AMP changes in plasma and liver tissue.

Hepatic regeneration following portacaval shunt was evaluated in the light of the changes of 3',5'-cyclic AMP (cAMP) levels in plasma and liver tissue, and also plasma cAMP levels after glucagon administration, using a 70% hepatectomy and portacaval shunt model in rats. Ratios of liver to body weight recovered to 60% of pre-operative ratios 2 weeks after the operation. Plasma cAMP level decreased slightly, but insignificantly, 1 day and 3 days after the operation, then recovered to the pre-operative level. Hepatic cAMP concentration increased for 2 weeks after the operation. Plasma cAMP levels induced after glucagon administration did not increase until 3 days after the operation and were only 50% of pre-operative levels 4 weeks after the operation. From these results, liver regeneration following the portacaval shunt was remarkably delayed, but continued until at least 2 weeks after the operation.

Animals↗

Auditory brain-stem response in zitter rats with genetic spongiform encephalopathy.

Zitter rats with genetic spongiform encephalopathy and hypomyelination developed an abnormal auditory brain-stem response (ABR) before the appearance of spongy lesions in the central nervous system (CNS). The ABR abnormalities were characterized by a dual peak of wave I, with a longer latency than in normal rats, and decreased or absent waves III and IV. Hypomyelination in both peripheral and central nerves may have been responsible for these abnormalities. The slow negative wave became wide and obscure with aging. These changes accompanied age-dependent progression of spongy changes in the CNS. These findings suggest that at least two mechanisms, one involving hypomyelination and the other causing spongy lesions, are responsible for the brain-stem auditory pathway dysfunction in zitter rats.

Action Potentials↗

Molecular analysis of virus-producing and non-producing clones derived from a defective SSPE virus Yamagata-1 strain.

Two virus clones were isolated from a defective SSPE virus, the Yamagata-1 strain, and designated as the YA and YF clones. The YA clone-infected cells produced neither cell-free virus nor cell-associated virus, whereas the YF clone-infected cells produced both cell-associated and cell-free virus. No difference of epitopes on structural proteins was observed between these two clones. Both clones had hemadsorption activity. Quantitation of structural protein by Western dot blots showed relatively a lower amount of M protein in the YA-infected cells than that in the YF-infected cells. The ratio, P plus M dicistronic/M monocistronic mRNA, in the YA-infected cells was about twice that in the YF-infected cells. Sequence analysis of cDNA corresponding to P plus M dicistronic mRNA revealed that the deduced M protein of the YF virus was smaller than that of the YA virus by five amino acids from the carboxy terminal. These results suggest that abundant production of P plus M dicistronic mRNA is responsible for the reduced amount of M protein in the non-productive YA clone.

Amino Acid Sequence↗

Anti-reflux surgery by injection of Teflon paste.

Over a 3-year period, 55 refluxing ureters in 36 patients were treated by the endoscopic injection of Teflon paste. Although reflux was corrected immediately in 54 ureters (98%), reflux recurred 3 to 4 months later in 18 ureters. Reinjection was carried out once in 5 ureters and twice in 1. The success rate was 71% in primary reflux and 53% in secondary reflux. Significant side effects were encountered post-operatively in 3 patients: vesicoureteric junction obstruction in 2 and urethral stricture in 1. We recommend that the results of surgery should not be evaluated until at least 3 to 4 months after operation. A review of the literature shows that the overall success rate was 92% in 367 ureters with primary reflux and 70% in 181 ureters with secondary reflux. Because of the uncertain outcome of surgery and the possibility of adverse side effects, one should be cautious when considering this form of treatment in young children.

Adolescent↗

Pulpal and radicular changes following maxillary subapical corticotomy.

Pulpal and radicular changes after subapical corticotomy in combination with posterior transfer of the maxilla were studied histopathologically using monkey jaws. When the surgical procedures were successful, the pulp tissues were kept alive, even though some slight atrophy and degeneration appeared. In some cases, however, severe reticular atrophy occurred which might be due to anaemia during operations.

Animals↗

Elevated ratio of late measles among subacute sclerosing panencephalitis patients in Karachi, Pakistan.

Subacute sclerosing panencephalitis (SSPE) in Western countries and Japan is found more often in early- than in late-measles sufferers. Recent SSPE findings in Karachi, however, present a different picture. Age at measles contraction was obtained and analyzed for 44 SSPE patients identified in Karachi between 1983 and 1988. The ratios of early- (< 2 years of age) and late- (> or = 2 years of age) measles sufferers among 36 of these patients who had experienced only one attack of measles were 0.33 and 0.67, respectively. This is in striking contrast to the predominance of early measles in the SSPE histories reported in Japan and an number of Western countries.

Age Factors↗

Angiotensin-converting enzyme inhibition attenuates hypercholesterolemia and glomerular injury in hyperlipidemic Imai rats.

Hyperlipidemic Imai rats spontaneously develop hypercholesterolemia, proteinuria and glomerulosclerosis. We investigated the effect of enalapril, an angiotensin-converting enzyme (ACE) inhibitor, on spontaneous hypercholesterolemia and the progressive renal injury in this rat strain. Male Imai rats (n = 7) were treated with enalapril at a dose of 50 mg/l in drinking water starting at 6 weeks of age. Body weight, blood pressure, urinary protein excretion and serum constituents were checked and compared with untreated controls (n = 5) up to 38 weeks of age. Enalapril treatment significantly reduced hypercholesterolemia (247 +/- 41 vs. 102 +/- 13 mg/dl, p < 0.01, at 38 weeks) and proteinuria (766 +/- 290 vs. 206 +/- 119 mg/kg/day, p < 0.01, at 38 weeks). The glomerulosclerosis index (SI) was significantly higher in untreated control rats than in the enalapril-treated group (227 +/- 57 vs. 27 +/- 9, p < 0.01). Although we could not clarify whether hypercholesterolemia is a primary event or secondary to the nephrotic syndrome, these results indicate that the ACE inhibitor has the property to protect remnant glomeruli from glomerulosclerosis in male Imai rats as well as in other animal models in which focal and segmental glomerulosclerosis is believed to represent a common pathologic pattern. This rat strain represents a unique model of a spontaneous proteinuria which can provide an important information on the pathogenesis of human focal and segmental glomerulosclerosis.

Angiotensin-Converting Enzyme Inhibitors↗

Immunohistochemical and histopathological study of experimental rabies infection in mice.

An immunohistochemical and histopathological study using the ABC technique was carried out to examine time-sequential virus spread in the central nervous system (CNS) of mice after inoculation with the CVS strain of fixed rabies virus by different routes; intracerebral (ic), intraocular (io), intranasal (in), intramuscular (im) and subcutaneous (sc). Only the ic and io inoculations caused fatal infections, so that detailed analysis was conducted on mice inoculated by these two routes. In ic-inoculated mice, viral antigens were detected mainly in neurons in the cerebral cortex and in the pyramidal cells and granular cells of the hippocampus. After io inoculation, viral antigen was first detected in the trigeminal nerve ganglia, following which it spreads to the cerebral cortex and cerebellum. In the hippocampus only a few cells were viral antigen-positive at the early stage after io inoculation. There were no inflammatory lesions or Negri bodies in the CNS of mice infected by either route. This suggests that clinical signs such as ataxia or depression leading to death may be due to the direct effect of the virus on the functions of neural cells, but not to inflammatory reactions. The ABC method will be useful for the early diagnosis of suspected patients or animals to have the disease when conventional histopathological and immunofluorescent antibody techniques can not detect lesions or viral antigens.

Animals↗

Ultrastructural findings in the inner ear of Jackson shaker mice.

The ultrastructural characteristics of the inner ear of Jackson shaker mice were analyzed. We used 12 Jackson shaker mutants (js/js) with ages ranging from 10 to 47 days and 10 heterozygotes of the Jackson shaker (js/+) with ages ranging from 10 to 30 days. The most striking findings observed were incomplete differentiation of the stereocilia of the outer hair cells and the maculae, although outer and macular hair cell cytoplasm, including the nerve terminals, became fully developed. Most outer hair cells did not show regular W-shaped configuration of the stereocilia throughout the entire turns of the cochlea except for a few hair cells. In many hair cells of the utricular and saccular maculae, the classical pipe organ configuration of the stereocilia was not observed. The Jackson shaker mice have been reported to have a gene abnormality on chromosome 11, and its gene locus was close to that of our new-mutant mice which showed deranged stereocilia of the outer and macular hair cells. Therefore, future studies can provide additional information on the cytodifferentiation of the stereocilia as a function of the gene on chromosome 11.

Animals↗

[Urodynamic findings in patients with a urethral Kock pouch after radical cystectomy].

Urodynamic evaluation was performed in 11 male patients, who underwent radical cystectomy with pelvic lymph node dissection for bladder cancer followed by bladder replacement with a urethral Kock pouch, 3 to 21 months after the operation. Frequency of micturition were 4.9 +/- 1.5 times (mean +/- S.D.) during the day-time and 1.5 +/- 1.2 times during the night-time. Tidal volume of micturition ranged from 300 to 550 ml and residual volume from 10 to 30 ml. Urinary continence was completely preserved in all patients (100%) during the day-time and 8 (72.7%) during the night-time. On pouchmetry, maximum capacity of the pouch was 429.2 +/- 82.4 ml, and intra-pouch pressure was 16.2 +/- 5.4 cmH2O at the capacity of 200 ml and 38.7 +/- 11.5 cmH2O at the maximum capacity. Maximum intra-pouch pressure on voiding was 80.0 +/- 19.4 cmH2O. Uroflowmetry demonstrated intermittent voiding curves in all the patients, with maximum flow rate of 15.2 +/- 6.5 ml/sec, voided volume of 405.9 +/- 80.7 ml and residual rate of 4.5 +/- 2.6%. Maximum intra-urethral pressure at the external urethral sphincter was 28.0 +/- 11.3 cmH2O when the pouch was empty and increased in response to pouch filling up to 64.7 +/- 27.0 cmH2O. Maximum urethral closing pressure and total profile length on the urethral pressure profile were 30.2 +/- 12.4 cmH2O and 20.9 +/- 9.0 mm, respectively, with the pouch empty, and 23.2 +/- 14.5 cmH2O and 20.0 +/- 7.6 mm, respectively, with the pouch full.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

[Results in treatment of urinary incontinence in the elderly].

The diagnosis and treatment of urinary incontinence in the elderly out-clinic patients were reviewed. Sixty-three patients (24 males and 39 females) over 60 years old, who consulted our clinic complaining urinary incontinence, were subjected to the present study. The patients' ages ranged from 60 to 91, with the mean age of 72.9 years old. The types of the incontinence were urge in 44 cases (69.8%), stress in 10 (15.9%), outflow in 5 (7.9%) and mixture of urge and stress in 4 (6.4%). Urge incontinence resulted from unstable bladder in 63.6% and from neurogenic bladder (overactive detrusor) in 36.4%. Cerebrovascular diseases were the most common cause of the neurogenic bladder. Fifty-four patients (85.7%) were out-patients and 9 (14.3%) were hospitalized for other diseases. Thirteen patients (20.6%) with dementia were included. Diagnosis was made on the basis of a detailed questionnaire, physical examination and voiding chart, and confirmed by urodynamic study. Treatment was positively made by means of drug therapy, operation, clean intermittent catheterization and/or behavior training. As results, incontinence disappeared in 52.4% (frequency of incontinence/day: 5.0 +/- 2.6 times/day to 0), was fairly improved in 30.2% (5.1 +/- 2.3 to 1.2 +/- 0.8), was slightly improved in 7.9% (3.4 +/- 1.4 to 2.4 +/- 1.4) and unchanged in 9.5% (8.2 +/- 2.3 to 8.3 +/- 2.2). Severe neurogenic bladder (overactive), dementia and physical disability were proposed to be important factors responsible for treatment failure. Aggressive therapy should be tried to treat the urinary incontinence in the elderly, since favourable results can be expected in most of the cases.

Aged↗

Down-regulation of prostaglandin E2 receptors in regenerating rat liver and its physiological significance.

The properties of prostaglandin (PG) E2 receptors in regenerating liver were studied using rat hepatocytes in primary culture. The control cells possessed stereo-specific PGE2 receptors with Bmax and Kd values, at 4 degrees C, of 526 fmol/mg protein and 6.5 nM respectively. In cells from regenerating liver after 70% hepatectomy, Bmax was reduced to 42-43% that of the controls; Kd did not change. Administration of indomethacin before surgery prevented Bmax reduction. These results indicate that PGE2, produced during the regeneration process, evoked cellular events and regulated the density of its receptors.

Animals↗

Nucleotide sequence of cDNA to the rinderpest virus mRNA encoding the nucleocapsid protein.

The full-length cDNA corresponding to the mRNA encoding the nucleocapsid protein (NP) of rinderpest virus (RV) was cloned and its complete nucleotide sequence was determined. The gene of RV-NP was composed of 1683 nucleotides and contained a single large open reading frame, which is capable of encoding a protein of 525 amino acids with a molecular weight of 58,241 Da. The nucleotide sequence and predicted amino acid sequence were compared with those of measles virus (MV) and canine distemper virus (CDV). The nucleotide sequence of the coding region of RV-NP (53-1630) revealed a homology of 68.1% and 63.0% with MV and CDV-NP, respectively. Relatively moderate homologies of 68.7% (MV) and 64.3% (CDV) were found at nucleotides 53-592. The highest homology of 75.3-74.3% was equally present between RV and both MV and CDV in the middle region at nucleotides 593-1312. The homologies of the predicted amino acids in this region were 88.3% (MV) and 86.3% (CDV). Relatively low (MV) or little (CDV) homology was detected in the last 318 nucleotides toward the 3' terminus (1313-1630). The predicted secondary structures of amino acids at the C terminus differed between the three viruses.

Amino Acid Sequence↗