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Biomedical subjects

Y Yasuda

Publications and source records attributed to Y Yasuda.

At least 253 records · Page 14Linked to original sources
PubMed1989

Presence of proteins derived from the vegetative cell membrane in the dormant spore coat of Bacillus subtilis.

To confirm the presence of the outer spore membrane in dormant spore coats of Bacillus subtilis, the proteins from vegetative cell membrane and dormant spore coat fractions were compared by immunoblot assay with antibodies prepared against both preparations. The spore coat fraction contained at least 11 proteins antigenically identical to those in the vegetative cell membranes. Further, the cytochemical localization of the proteins derived from vegetative cell membrane in dormant spores was examined by an immunoelectron microscopy method with a colloidal gold-immunoglobulin G complex. The colloidal gold particles were observed in the coat region and around the core region of dormant spore. These results have provided evidence that some proteins from vegetative cell membrane remain in the dormant spore coat region of B. subtilis, although it is not clear whether the outer membrane persists as an intact functional entity or not.

Antibodies, Bacterial↗
PubMed1989

Recurrent pancreatitis in the third trimester in 2 consecutive pregnancies--its relationship to liver histology: a case report.

A 20-year-old woman who had recurrent pancreatitis in the third trimester in 2 consecutive pregnancies was reported. Her liver histology was indistinguishable from acute fatty liver of pregnancy, although she showed no clinical signs. The relationship between idiopathic acute pancreatitis during pregnancy and acute fatty liver of pregnancy was discussed.

Adult↗
PubMed1989

Hepatocellular lipofuscin in pre-eclampsia.

Thirty liver specimens from 30 pre-eclamptic women with and without liver dysfunction were examined for the amount of lipofuscin pigment deposited. The amount of hepatic lipofuscin correlated positively with plasma urate concentrations. This finding may indicate an involvement of oxygen-free radicals and xanthine oxidase in the pathophysiology of pre-eclampsia.

Female↗
PubMed1989

Predictability of left heart dysfunction from right heart performance--cardiac index-venous pressure plots and cardiac index-mean pulmonary artery wedge pressure plots at rest and their shift during dynamic exercise.

In an attempt to examine the extent to which the right heart performance can predict the left heart performance in heart diseases primarily affecting the left heart, we recorded cardiac index-venous pressure (CI-VP) plot and cardiac index-mean pulmonary artery wedge pressure (CI-PAW) plot at rest and investigated the shift of CI-VP plot and CI-PAW plot that occurred during mild dynamic exercise of the lower limbs. Six patients had normal heart function and 20 patients had heart diseases primarily affecting the left heart. The sensitivity, specificity, positive predictive value and negative predictive value in the estimation of the left heart function with delta CI/delta VP were 80%, 100%, 89% and 100%, respectively, when delta CI/delta PAW was regarded as the golden standard for the estimation of the left heart function. The sensitivity, specificity, positive predictive value and negative predictive value in estimating the left heart function with delta CI/delta RA were 86%, 93%, 92% and 86%, respectively. When the left heart function was estimated by delta VP alone without measuring delta CI, the sensitivity, specificity positive predictive value and negative predictive value were 40%, 100%, 73% and 100%, respectively. In short, it was possible to predict the left heart dysfunction with delta CI/delta VP or delta CI/delta RA, in the presence of the right heart dysfunction. It was also possible to predict a steep heart slope from normal delta CI/delta VP with error of 2/18 (11%), when steep left heart slope was predicted, based on the presence of steep right heart slope. In comparison, delta VP alone was a less sensitive index of the performance of the left heart.

Adolescent↗
PubMed1989

Development of Babesia ovata in the midgut of the tick, Haemaphysalis longicornis.

Studies were made on the development of Babesia ovata in the midgut of the nymphal tick vector, Haemaphysalis longicornis. In 12 hr post-repletion, merozoites were observed outside of erythrocytes infected with B. ovata in the contents of the midgut of the tick. After that, these merozoites were transformed into ring-forms which were comparatively large ring 2-3 microns in diameter. Within 48-72 hr post-repletion, ring-form protozoa developed into spherical form 4-5 microns in diameter. Within 3-4 days post-repletion, fission-forms were transformed into fission-bodies 2-3 microns in diameter. Within 4-6 days post-repletion, fission-bodies developed into bizarre-forms 6-7 microns in diameter. At this time, elongated form protozoa which were considered as microgametes, 6-8 microns in length, are also seen. Within 6-8 days post-repletion, round-formed protozoa which were considered as zygotes in 9-10 microns in diameter were observed in the gut. About 10 days after repletion, those round-formed protozoa were transformed into vermicule-formed and round-formed protozoa, 13-15 microns in length, appeared again in the gut epithelial cells.

Animals↗
PubMed1989

The genetics of coat colors in the mongolian gerbil (Meriones unguiculatus).

Genetic studies demonstrated three loci controlling coat colors in the Mongolian gerbil. F1 hybrids of white gerbils with red eyes and agouti gerbils with wild coat color had the agouti coat color. The segregating ratio of agouti and white in the F2 generation was 3:1. In the backcross (BC) generation (white x F1), the ratio of the agouti and white coat colors was 1:1. Next, inheritance of the agouti coat color was investigated. Matings between agouti and non-agouti (black) gerbils produced only agouti gerbils. In the F2 generation, the ratio of agouti to non-agouti (black) was 3:1. There was no distortion in the sex ratios within each coat color in the F1, F2 and BC generations. This indicated that the white coat color of gerbils is governed by an autosomal recessive gene which should be named the c allele of the c (albino) locus controlling pigmentation, and the agouti coat color is controlled by an autosomal dominant gene which might be named the A allele of the A (agouti) locus controlling pigmentation patterns in the hair. The occurrence of the black gerbil demonstrated clearly the existence of the b (brown) locus, and it clearly indicated that the coat colors of gerbils can basically be explained by a, b, and c loci as in mice and rats.

Animals↗
PubMed1989

Isolation and characterization of new antibiotics resorcinomycins A and B.

New antibiotics, resorcinomycins A and B, were isolated from the culture broth of a streptomycete strain identified as Streptoverticillium roseoverticillatum. The antibiotics are water-soluble amphoteric substances, positive to SAKAGUCHI'S reagent. The molecular formulas C14H20N4O5 and C13H18N4O5 for A and B were indicated by elemental analysis and secondary ion MS. The structures of these antibiotics were determined by 1H and 13C NMR spectrometry and some chemical evidences to be N-[(S)-alpha-guanidino-3,5-dihydroxy-4-isopropylphenylacetyl]glyci ne and N-[(S)-alpha-guanidino-3,5-dihydroxy-4-ethylphenylacetyl]-glycine, respectively.

Actinomycetales↗
PubMed1989

Isolation and characterization of thioxamycin.

A new peptide antibiotic named thioxamycin which contained thiazole and oxazole rings was isolated from the culture broth of Streptomyces sp. The antibiotic is acidic and lipophilic in nature. A molecular formula, C52H48N16O15S4, was indicated by elemental analysis and MS. One mol of threonine and three unusual amino acids were detected by amino acid analysis of the acid hydrolysate. The antibiotic is active in vitro against anaerobic Gram-positive and Gram-negative bacteria and also aerobic Gram-positive bacteria.

Animals↗
PubMed1989

Alterations in migrating cranial neural crest cells in embryos of mice fed retinoic acid.

Alterations in migrating neural crest cells induced by all-trans retinoic acid (RA) were studied morphologically and immunohistochemically in the cranial portion of 8-day-old mouse embryos which were derived from dams given 60, 40 or 0 mg kg of RA and killed 2 to 8 h later. Additionally, the embryos exposed to 4 mg/kg of actinomycin D (AD) on day 8 of gestation for 5 h were examined similarly. Light microscopy revealed that RA was cytotoxic and caused the appearance of pleomorphic nuclei, extra-large nucleoli and cytoplasmic budding which replaced lamellipodia and spike-like projections. Electron microscopy revealed pleomorphic nuclei containing nucleoli with major granular portions frequently surrounded with heterochromatin, monosomes, and phagosomes. A monosomal distribution pattern was different from that seen in the neural crest cells exposed to AD. The latter showed incomplete polyribosomal dispersion with fewer nucleolar components. Fewer neural crest cells with choline acetyltransferase-like immunoreactivity were detected in RA- and AD-exposed embryos than in the controls. These findings suggest that excess RA inhibits acetylcholine synthesis of the migrating neural crest cells, in a manner different from AD, and that it enhances phagocytosis. These phenomena modify the characteristics of neural crest cells resulting in craniofacial malformations.

Animals↗
PubMed1989

Thalidomide may inhibit proliferation of mesenchyme in human limb buds.

Limb buds from 4- and 4.5-week-old human embryos were cultured on agar medium consisting of Medium 199, chick embryo extract and horse serum for 4 days with or without thalidomide (1-1.5 microgram/ml), and the direct effect of thalidomide was examined morphologically in histological preparations. In the explants treated with thalidomide, mitotic figures of mesenchymal cells were significantly decreased both in overall explant and in mesenchymal cell aggregates, but the extracellular matrix in the mesenchymal cell aggregates was seen in the experimental and control explants. These findings suggest that thalidomide affects undifferentiated and differentiated mesenchymal cell proliferation but not the chondrogenic capacity of the mesenchyme.

Cartilage↗
PubMed1989

Experimental approaches for the prevention of hematogenous metastasis.

With improvements in surgical procedures and cure rates, the probable course of cancer for the majority of patients is now largely determined by metastasis rather than growth of the primary tumor itself. Thus, metastasis has received increasing attention over the past decade. These studies have led to the identification of several of the molecular events crucial for metastatic dissemination, information which is now being used to design therapeutic strategies to inhibit metastasis formation. Even though the molecular events involved in the dissemination of malignant disease are only partially known, several promising agents are now being tested for their capacity to limit the spread of cancer. A few clinical trials have shown benefit in prolonging survival and disease-free state, particularly when such therapy is employed on an adjuvant basis.

Antineoplastic Agents↗
PubMed1989

Development of Babesia ovata in the haemolymph of the tick, Haemaphysalis longicornis.

The haemolymph of adult tick Haemaphysalis longicornis (H. longicornis) infected with Babesia ovata (B. ovata) was examined at regular intervals. As a result kinetes could be detected in the haemolymph 15 days after engorgement. The kinetes detected could be classified into three types on the basis of their morphological characteristics. They increased gradually in number, reaching a maximum 23 days later. Then they tended to decrease in number, disappearing almost completely from the haemolymph 38 days after the engorgement of ticks.

Animals↗
PubMed1989

Weber-Christian disease associated with multiple perforations of the ileum and colon.

Panperitonitis developed in a 57-yr-old Japanese man during the course of Weber-Christian disease (WCD). Emergent operation disclosed three perforations of the ascending colon and two of the distal ileum. Histological study of the surgical specimen showed that all perforations were located at the centers of acute subserosal panniculitic foci. No vasculitis was discerned. In the previously reported three cases of WCD with intestinal perforation, perforation was solitary and seen in the small intestine. The cause of perforation was considered to be vasculitis in two cases. In the remaining one, panniculitis around the perforation was in chronic granulomatous stage. This was the first case of WCD in which acute subserosal panniculitis caused multiple ileocolonic perforations.

Acute Disease↗
PubMed1989

[Paramedian thalamic and midbrain infarcts associated with palilalia].

We report a case with paramedian thalamic and midbrain infarcts associated with palilalia. A 62-year-old man fell into a comatose state, and was admitted to an emergency hospital. Two days later, his consciousness level began to improve. Neurological examination revealed bilateral cerebellar ataxia, oculomotor nerve palsy, lack of spontaneity, and amnesia. Deep tendon reflexes were normal on all extremities, and no muscular weakness was observed. Babinski sign was noted on the right side. Muscle tone was decreased. No sensory disturbance was found. Two months later, he began to show compulsive repetition of syllables, words, or phrases, and was transferred to our hospital. He involuntarily repeated one syllable or a word five to ten times in spontaneous speech, repetition of phrases being not so frequent as that of syllables or words. This speech abnormality was considered as palilalia, which Souques first reported in 1908. The palilalia of this patient was rarely noted when he repeated words spoken to him by the examiner. As he spoke, the rate of speech gradually increased, the loudness reduced, and finally he began to whisper (palilalie aphone). The palilalia continued for four months. MRI showed infarcts in the medial thalami, subthalamic and midbrain on both sides. Auditory brainstem response showed delayed latency of bilateral V waves, and EEG revealed bilateral theta waves. In this patient no lesion other than thalamus, subthalamus and midbrain was detected by MRI. It is suggested that bilateral lesion of the thalami and their projection areas caused palilalia in this patient.

Cerebral Infarction↗
PubMed1989

[Surgical treatment for thoracoabdominal aortic aneurysm].

Despite improvements of the results of aortic aneurysm repair, technical difficulty and a high incidence of perioperative morbidity still remains in the thoracoabdominal aortic aneurysm surgery. In this paper, we reported 19 cases of operation for thoracoabdominal aortic aneurysm and retrospectively studied surgical technique, early results and late results after operation. Graft inclusion technique with direct vessel reattachment was mainly employed for aortic reconstruction, and for 2 cases of inflammatory aneurysm. Hardy's operation and extraanatomic bypass were performed. Mortality was 16% with a 13% mortality for elective repair and paraplegia occurred in 2 cases (10%). Current results with thoracoabdominal aortic aneurysm repair established its safety, but to prevent postoperative paraplegia completely, the consideration for operative adjuncts and mechanisms of paraplegia needs to be continued.

Adult↗
PubMed1988

Quantitative HPLC analysis of acidic opines by phenylthiocarbamyl derivatization.

A new method for the quantitative analysis of acidic opines--alanopine, strombine, tauropine, and beta-alanopine--is presented. The method is based on formation of phenylthiocarbamyl (PTC) derivatives of the acidic opines after partial purification by ion-exchange chromatography. The PTC acidic opines are separated by reverse-phase high-performance liquid chromatography (HPLC) and detected within 20 min by ultraviolet absorbance. This HPLC method gives higher sensitivity, 10-30 pmol minimum detection, and better reproducibility than the high-voltage paper electrophoresis method. There is also good agreement for the three acidic opines (alanopine, strombine, and tauropine) when compared by HPLC and electrophoresis methods. Accumulation of beta-alanopine was observed for the first time in the adductor muscle of blood shell, Scapharca broughtonii, during aerial exposure by application of the HPLC detection method.

Alanine↗
PubMed1988

The cell interaction sites of fibronectin in tumour metastasis.

Adhesion to specific extracellular matrix molecules appears to be an important prerequisite for successful target organ colonization by metastasizing tumour cells. Interference in the adhesive function of malignant cells with antiadhesive agents is therefore one potential approach for preventing metastasis. Recently, synthetic peptides taken from the cell interaction sites of fibronectin have been characterized as inhibitors of cellular adhesion in vitro. Using these antiadhesive probes we have examined the role of cell adhesion to fibronectin in tumour metastasis using the B16-F10 murine melanoma model system. Two sequences from the IIICS cell-binding domain, the 25-mer CS1 peptide and the tetrapeptide Arg-Glu-Asp-Val (REDV), had no detectable activity, but the pentapeptide Gly-Arg-Gly-Asp-Ser (GRGDS), an active sequence from the central cell-binding domain, exhibited potent, dose-dependent inhibition, indicating a role for this cell recognition determinant in tumour metastasis. Under appropriate conditions GRGDS treatment afforded remarkable protection to the host; mice injected with melanoma cells and peptide were still alive 15 months after injection whereas mice injected with melanoma cells alone died within six weeks. Kinetic analyses of the retention of tumour cells in the lungs and of the vascular clearance rate of labelled GRGDS predict an early time frame of activity for the peptide. From the results of a variety of in vitro invasion and migration assays it appears that GRGDS may interfere with multiple, fibronectin-mediated adhesive and migratory events at different points of the metastatic cascade. In preliminary studies designed to optimize the therapeutic usefulness of GRGDS-like agents, peptide conjugates have been found to possess enhanced antiadhesive activity as well as an extended vascular clearance rate. In the future, therefore, these or related peptide derivatives may be potentially useful agents for the prevention of tumour metastasis.

Animals↗