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Biomedical subjects

S Yoshida

Publications and source records attributed to S Yoshida.

At least 991 records · Page 55Linked to original sources
PubMed1995

Aluminum-induced model of motor neuron degeneration: subperineurial injection of aluminum in rabbits.

Environmental factors, particularly chronic exposure to aluminum (Al) and manganese (Mn) with dietary deficiency of calcium (Ca) and magnesium (Mg), are speculated to be contributory in the pathogenesis of amyotrophic lateral sclerosis (ALS). However, the mechanisms by which these elements accumulate in the CNS tissues and induce neuronal death are not known. In the present study, we investigated the retrograde transport of Al as a possible mechanism of pathogenesis. Al (as aluminum chloride or maltol) was injected into the subepineurial space of the sciatic nerve with subsequent morphological evaluation of the neurotoxic effect on spinal motor neurons in rabbits. Spheroid/globules, central and peripheral chromatolysis, and neuronal degeneration were observed in the spinal anterior horn in Al-maltol, Al chloride, and maltol treated rabbits to more marked extent than those in uninjected or saline controls. By electron microscopy, the soma and dendrites of neurons in the anterior horn at the fifth lumbar spinal cord in the Al-treated rabbit showed marked edematous change, fragmentation of granular endoplasmic reticulum, increased accumulation of neurofilament, and accumulation of free ribosomes and lipid-droplet-like structures. Horseradish peroxidase (HRP) reactive product was seen in the axons and cytoplasm of Schwann cells of the sciatic nerve in Al-maltol treated rabbits, suggesting that the permeability of the blood-nerve-barrier was increased by injection of Al-maltol. We suggest that Al, subperineurially injected, was absorbed into the spinal cord and induced degeneration of spinal motor neurons in these rabbits. These findings indicate that the retrograde transport of Al into spinal motor neurons via the peripheral nervous system may exacerbate neuronal degeneration in ALS.

Aluminum↗
PubMed1995

Implementation and evaluation of computerized patient management problems.

We developed and implemented computerized patient management problems (CPMP) for medical school education as a simulation of case management and evaluated its efficacy in the School of Medicine at Chiba University. PMP was first developed in the USA; it was used for examinations by the board of American College of Physicians and then introduced to Japan for examination purposes. This test is a practical clinical test for decision making in various medical situations. PMP is, however, a kind of case simulation from a doctor's point of view; it is also a sophisticated tool in training medical students. PMP had many disadvantages in the past, but by computerizing PMP, we solved many problems. We developed the CPMP system for bedside teaching and evaluated its efficiency in terms of education by giving the same test twice and analyzing a survey.

Audiovisual Aids↗
PubMed1995

Eliminating effects of an air purifier on infectants during dental procedure.

Blood and drill dust from dental plaque microorganisms, teeth, and filling materials can cause environmental pollution in the dental clinic. Currently, as a preventive measure against air pollution from a patient's mouth during dental treatment, dust-collecting aspirators such as an extra-oral vacuum aspirator (EOVA) are coming into general use. We tested the eliminating effects by the EOVA with the plaque solution aerosol and the aerosol from drilling a tooth by examining the distribution of floating aerosol in the air turbine's tank when a plaque solution was sprayed and when a human tooth was drilled with a plaque solution. We concluded that infectious aerosol increases in diameter with the drilling of human teeth to the size of about 0.5-5.0 micrometers, which is microbiologically and hygienically hazardous and also can be inhaled without much difficulty.

Aerosols↗
PubMed1995

[Neurophysin].

Explore the source record for details and available documents.

Female↗
PubMed1995

[Thoracotomy as treatment for pneumothorax associated with pneumocystic carinii pneumonia in a patient with hemophilia A and the acquired immunodeficiency syndrome].

Pneumocystis carinii pneumonia is the most common respiratory infection in patients with the acquired immunodeficiency syndrome, and inhalation of pentamidine aerosol is currently used for secondary prophylaxis. A 16-year-old patient with hemophilia A and the acquired immunodeficiency syndrome had a spontaneous pneumothorax during inhalation of pentamidine aerosol for secondary prophylaxis of Pneumocystis carinii pneumonia. Tube thoracostomy and pleurodesis were done without success. Thoracotomy was done 27 days after admission. The patient tolerated the procedure well, and the postoperative course was uneventful. Grocott staining of tissue from the bronchopleural fistula revealed Pneumocystis carinii, which suggests that the pentamidine aerosol failed to control and active Pneumocystis infection in peripheral lung zones.

AIDS-Related Opportunistic Infections↗
PubMed1995

[Role of pharmacist in cancer pain management].

It is essential for patients to have understanding of the significance of morphine administration and to cope well with its side effects, as it leads to enhancement of the analgesic effects of morphine in the treatment of cancer pain. Since August 1993 we have used the booklet "Relieving Pain Effectively--Manual for Patients" and have consulted up to date approximately 670 patients about taking narcotics. The initial information eliminates the anxiety before taking morphine--we set up the time that each patient should take medicine to fit their life-style and explain about the the medicine and its side-effects. For this reason, the above information takes approximately 30 to 60 minutes per patient. We guide the patient over to over till the pain and side-effects have disappeared and file a "Morphine Education Record" with the details. We also prepare a "Pain and Side-Effect Control Sheet" that consists of 6 items and a pain scale where 0 equals no pain and no side-effect and 5 equals most pain and side-effects. Patients select the scale themselves every day. Pharmacists provide the information to a doctor and advise him on steps against side-effects, selection of dose, interval and rescue-dose. This is a report on the role of the pharmacist in patient narcotics guideline for cancer pain management.

Humans↗
PubMed1995

Induction of reparative dentin formation in dogs by bovine bone morphogenetic protein bound to ceramic dentin.

Bone morphogenetic protein (BMP) refers to a group of bone-inducing growth factors used to enhance experimental osseous repair. Previous studies have indicated that BMP promotes the proliferation and differentiation of fibroblasts from human dental pulp both in vitro and in vivo. Furthermore, when BMP is used as a pulp capping agent, it has ability to induce the formation of both osteodentin and tubular dentin. In this study, we sought to explore whether or not BMP, complexed to ceramic dentin (BMP/CD), would constitute a more effective pulp capping agent than BMP alone. Experimental pulp exposures were created in dogs, and BMP/CD was placed on the surface of the exposed dental pulp. The inductive effect of such stimulation on reparative dentin formation was observed morphologically. Results showed that two weeks after exposure, some osteodentinal matrix was formed in the space surrounding the implanted BMP/CD particles while the remainder of the space was occupied by proliferating fibroblasts. At 4 weeks postoperatively, the dential bridge was complete. When ceramic dentin without BMP was used, there was minimal bone-like matrix formed even at 4 weeks postoperatively. These results suggest that the BMP/CD complex is effective as a stimulant of reparative dentin formation and shows potential as a therapeutically useful pulp-capping agent in a clinical setting.

Animals↗
PubMed1994

[A new cellulose-barium gel for computed tomography of the esophagus].

A new oral contrast agent for CT of the esophagus was evaluated for its ability to coat the esophageal lumen in 12 patients with esophageal diseases. This agent is made of carboxymethyl cellulose sodium, potato starch and low-density barium, and has remarkably high viscosity of 13600 centipoise. The esophagus was divided into proximal, mid, and distal segments to analyze the effectiveness of lumenal opacification. The average percent opacification of these segments was 78.7, 86.4, and 63.4%, respectively, for all patients. This agent is expected to play a possible role in the CT diagnosis of esophageal cancer by helping to determine the indications for radical surgery and/or radiotherapy.

Barium Sulfate↗
PubMed1994

Islet amyloid polypeptide and its N-terminal and C-terminal flanking peptides' immunoreactivity in islet amyloid of diabetic patients.

We determined immunohistochemically whether the islet amyloid polypeptide (IAPP)/amylin precursor is one component of islet amyloid, using polyclonal antibodies specific for human IAPP8-17 and amino (N)-terminal and carboxy (C)-terminal flanking peptides. To enhance immunostaining of the amyloid, we pretreated the pancreatic tissue sections with 100% formic acid. In three non-diabetic subjects, pancreatic islet cells were immunoreactive to anti-IAPP8-17 and anti-N-terminal and C-terminal flanking peptide antibodies and the reactivity was enhanced with formic acid pretreatment. In six type 2 diabetic subjects and a subject with type A insulin resistance, islet amyloid deposits were reactive to anti-IAPP8-17 antibody, but not to anti-N-terminal and C-terminal flanking peptide antibodies. Formic acid pretreatment markedly enhanced the reactivity to anti-IAPP8-17 antibody; however, it failed to show the reactivity to anti-N-terminal and C-terminal flanking peptide antibodies. Formic acid pretreatment of pancreatic tissue sections prepared for immunostaining is useful for visualization of buried epitopes of mature IAPP and its precursor molecules, either in islet amyloid deposits or in the islet cells. We conclude that the IAPP precursor and N-terminal and C-terminal flanking peptides are not constituents of human islet amyloid.

Adult↗
PubMed1994

C-type natriuretic peptide inhibits intimal thickening of rabbit carotid artery after balloon catheter injury.

C-type natriuretic peptide (CNP) stimulated cGMP production in rabbit cultured vascular smooth muscle cells, and thymidine uptake was inhibited by CNP. We tested whether CNP inhibits the development of intimal lesions induced by balloon catheter injury in rabbit common carotid artery. CNP (1 microgram/kg/min) infusion through the left jugular vein by DIB balloon catheter pump was started at 30 min before injury and continued until sacrifice. The median of the mean ratio of intima to media in each rabbit after 14 days was 29.5% [14.5-57.8] for control group and 12.0% [2.5-29.8] for CNP group (p < 0.01). Maximum ratio was also significantly low in CNP group. These results suggest that CNP may act as local regulator which suppresses intimal thickening.

Animals↗
PubMed1994

Mutational analysis of the proteolytic cleavage site of glycoprotein B (gB) of Marek's disease virus.

The Marek's disease virus (MDV) glycoprotein B (gB) precursor, gp100, is proteolytically cleaved into two disulfide-linked subunits, gp60 and gp49. In the gB homologs of most other herpesviruses, a tetrapeptide, Arg-Xaa-Arg-Arg, is immediately upstream from the predicted cleavage site. We have investigated the specificity of the proteolytic cleavage in gp100 by introducing mutations within its predicted cleavage site (Arg-Leu-Arg-Arg) and expressed these mutants in recombinant fowlpox virus (FPV). The results show that all three Arg residues at the predicted cleavage site play an important role in the specific proteolytic cleavage of gp100. Furthermore, we demonstrated that the cleavage of gp100 is not necessary for transport of gB to the cell surface.

Amino Acid Sequence↗
PubMed1994

Intracellular multiplication of Legionella pneumophila in Tetrahymena thermophila.

It has been shown that Legionella pneumophila proliferates intracellularly in more than ten species of protozoa, but the fate of the bacteria in Tetrahymena thermophila has not been reported. We investigated the multiplication of L. pneumophila Philadelphia-1 strain in micronucleated T. thermophila, and the effects of temperature and numbers of the bacteria ingested by the protozoa after in vitro feeding were studied. T. thermophila preyed actively upon the bacteria. After being ingested, the fate of the bacteria was affected by both temperature and the number of bacteria ingested. When the number of ingested bacteria was 30 per protozoon, the bacteria proliferated intracellularly at 35 degrees C. The bacteria, however, could not proliferate at 28 degrees C or 32 degrees C though they survived in the protozoa. When the ingested bacteria was 10 per protozoon, the bacteria were killed in the protozoa at all of the temperatures tested. Electron microscopic examination revealed that the protozoa ingesting the bacteria remarkably swelled and that protozoan food vacuoles which contained L. pneumophila were studded with ribosomes.

Animals↗
PubMed1994

A naturally occurring mutation at the second base of codon asparagine 43 in the proposed N-linked glycosylation site of human lipoprotein lipase: in vivo evidence that asparagine 43 is essential for catalysis and secretion.

The patient was a 20-year-old male. His fasting plasma triglyceride and cholesterol levels were 1258 mg/dl and 138 mg/dl, respectively. The lipoprotein lipase (LPL) activity and mass from postheparin plasma of the patient were 0.00 mumol/ml/h (normal range: 5.51 +/- 1.12) and 23 ng/ml (normal range: 220 +/- 42), respectively. DNA sequence analysis of the LPL gene from the patient revealed a homozygous nucleotide change: a A-->G transition at nucleotide position 383, resulting in an amino acid substitution of Ser for Asn43, which is believed to be an N-linked glycosylation site of the LPL mature protein. Expression studies of this mutant LPL cDNA produced an inactive LPL protein which was not secreted into the media.

Adult↗