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Biomedical subjects

S Hidaka

Publications and source records attributed to S Hidaka.

At least 145 records · Page 8Linked to original sources

[A report on 107 cases of obturator nerve block].

The obturator nerve passes in close proximity to the inferolateral bladder wall. Transurethral resection of bladder tumors close to these areas may stimulate the obturator nerve, causing violent adductor contraction and possible inadvertent bladder perforation. To avoid this reaction, local anesthetic blockade of the obturator nerve as it passes through the obturator canal is effective to stop adductor spasm during spinal anesthesia. We performed obturator nerve block in 107 cases by use of insulated needle and nerve stimulator, and measured the depth of the obturator nerve and that of the pubic tubercle. Obesity index was positively correlated with the depth of the obturator nerve as well as the pubic tubercle. However, no correlation was found between the obesity index and the difference of the depth of the obturator nerve and the depth of the pubic tubercle. It is suggested that if the needle is advanced in the direction of the obturator canal about 40mm further after reaching the pubic tubercle, the needle reaches the obturator nerve.

Adult↗

Induction of antitumor activity in macrophages by mycoplasmas in concert with interferon.

The in vitro growth of tumor cells infected with mycoplasmas was suppressed by macrophages pretreated with interferon (IFN), but the growth of mycoplasma-free tumor cells was not suppressed. Pretreatment of macrophages with IFN plus mycoplasmas or their soluble factors either simultaneously or sequentially, IFN first and mycoplasmas second, but not in the reverse order, was effective in activating macrophages to suppress the growth of mycoplasma-free tumor cells. Macrophages from C3H/HeJ mice (which respond only slightly to lipopolysaccharide) were activated by IFN plus mycoplasmas or their soluble factor, and their action was not influenced by the addition of a lipopolysaccharide-neutralizing agent, polymyxin B. These results suggest that the macrophage-activating agent in mycoplasmas does not mimic lipopolysaccharide. The administration of mycoplasmas plus IFN to mice with ascitic or solid tumors resulted in the reduction of tumor growth. The survival rate of tumor-bearing mice was improved by the administration of mycoplasmas, and this was synergistically enhanced by the addition of IFN. These results indicate (a) that mycoplasmas can be useful as a biological response modifier, and (b) that care should be taken to prevent contamination with mycoplasmas in experiments on macrophage activation.

Animals↗

In vitro messenger properties of a satellite RNA of cucumber mosaic virus.

The nucleotide sequence of a naturally occurring satellite RNA (satRNA) of cucumber mosaic virus strain F (CMV-F) isolated from Petasites japonicum Miq. has been determined. F-satRNA is 338 nucleotides long and possesses a single open reading frame (ORF; residues 11 to 91) in its 5-terminal region. Analysis of in vitro translation products of the RNA revealed that the major peptide synthesized had an Mr of 2800, corresponding to the value (Mr 2874) calculated from the amino acid sequence predicted from the ORF. Furthermore, a ribosome-binding fragment of the RNA in the initiation step of an in vitro translation system was found to contain the first AUG codon (residues 11 to 13). These results suggest that of the F-satRNA sequence, the coding region for the peptide can be assigned to the region from AUG to GGU (residues 11 to 91), accompanied by a termination codon UGA.

Base Sequence↗

[Possible mechanisms of hematoma formation in the urinary tracts in a patient with idiopathic thrombocytopenic purpura].

A 30-year-old female was admitted to our hospital complaining of hematuria and right flank pain in September, 1987. She had been diagnosed idiopathic thrombocytopenic purpura in 1980, and had similar symptoms before. Hematoma in the right ureter was demonstrated by retrograde pyelography and CT-scanning, and these symptoms improved within one month. Each activity of plasma clotting factors was within normal limits. Enzymatic studies of the urine revealed low values of plasmin-, urokinase-, and kallikrein-like activities in both excerbation and remission. These hemorrhagic tendencies might have been the result of marked thrombocytopenia: After bleeding into the urinary tracts began, the bleeding would tend to form hematoma because of elevated clotting activity; then hematoma would grow due to decreased urine fibrinolytic activities. This suggested that a decline of fibrinolysis in urine might have a promoting effect on the process of hematoma formation.

Adult↗

[Urothelial tumor in dialysis patients; report of four cases].

Four cases of urothelial tumors diagnosed during hemodialysis were reported. Patients' ages ranged from 43 to 74 years old. One case was female and others were male. Durations of dialysis at the time of diagnosis were 13 to 24 months. Chief complaints of these four cases were gross hematuria. One case with bladder tumor underwent emergency operation because of repeated bladder tamponade. Partial cystectomy was performed on this case. Other two cases with bladder tumor were treated with endoscopic method. Simple nephrectomy was done in the case with renal pelvic tumor. Post operative course in all four cases were uneventful without major complications.

Adult↗

Junctions form between catfish horizontal cells in culture.

Cone horizontal cells from the catfish retina extend out processes after a few days in culture that sometimes contact adjacent cone horizontal cells. Two types of specialized junctions were observed by electron microscopy along the newly formed contact areas. One junctional type consisted of prominent electron-dense material along and just under the plasma membrane of one or both of the contacting elements. Sometimes vesicle clusters were associated with these junctions. The other type of junction showed some electron-dense material along the membranes of both processes and patchy areas of close membrane apposition resembling gap junctions. In about half of the cases tested, electrical coupling was detected between cone horizontal cells that had made contact in culture. In no case was the coupling as tight as is typically found between horizontal cells that had formed gap junctions in vivo.

Animals↗

A prostaglandin oligomeric derivative inhibits activities of phospholipase and protease: a possible mechanism of membrane protection during ischemia.

A prostaglandin oligomeric derivative was synthesized by alkaline treatment of prostaglandin E1. This compound protected the perfused rat heart from global ischemia. This compound was found to inhibit several lipolytic and proteolytic enzymes in vitro. When phospholipase A2 from Naja naja venom was used as an enzyme and phosphatidylcholine was used as a substrate, 50 per cent inhibition was achieved at 50 microM of the prostaglandin derivative. When trypsin and casein were used as enzyme and substrate, 50 per cent inhibition was obtained at 80 microM. A possible mechanism of beneficial effect of this compound in protecting membranes during ischemia is discussed.

Animals↗

Complete nucleotide sequence of two new satellite RNAs associated with cucumber mosaic virus.

Complete nucleotide sequences of two new satellite RNAs (satRNA) of cucumber mosaic virus (CMV), E-satRNA and OY2-satRNA, have been determined and compared with known satellite RNA sequences. E-satRNA contained 339 nucleotide residues and OY2-satRNA had 386 nucleotide residues. Comparison of the sequences among satRNAs including these new satRNAs revealed extensive homologous regions in the 5'-terminus and the 3'-half. The former region contains about 95 nucleotide residues (80-100% homology) and the latter has about 175 nucleotide residues (81-99% homology), but there was less homology in the middle of the RNA. A possible secondary structure for E-satRNA, OY2-satRNA, and Y-satRNA [S. Hidaka et al. (1984) FEBS Lett. 174, 38-42] was constructed and compared with that of a satellite RNA from CMV-Q (Q-satRNA) [K. H. J. Gordon and R. H. Symons (1983), Nucl. Acids Res. 11, 947-960]. Two similar hairpin-loop structures in the 5'-terminal region were common features of the RNAs; one of them was found in E-satRNA, the other in OY2-satRNA, and both in Y-satRNA and Q-satRNA. Analyses of in vitro messenger properties of the satRNAs suggested that the first open reading frame of E-sat and Y-satRNAs was a possible coding region for protein synthesis.

Base Sequence↗

Dendritic morphology of indoleamine cells revealed by intracellular injection of lucifer yellow in fixed carp retina.

The dendritic morphology of indoleamine amacrine cells in carp retina was investigated by identifying their fluorescent cell bodies by preloading with noradrenaline followed by iontophoretic injection of Lucifer Yellow in isolated and aldehyde-fixed preparations under microscopic control. Although two subpopulations of serotonin-like immunoreactive amacrine cells (small and large in soma size) were found, small cells were not seen in aldehyde-fixed preparations. Cells preloaded with noradrenaline corresponded to large immunoreactive cells and were labeled with Lucifer Yellow. The cell bodies labeled were located at the innermost level of the inner nuclear layer, and gave rise to three to five primary dendrites which branched frequently and were found mainly in sublamina a of the inner plexiform layer. These cells examined in an intermediate region between the optic disc and the retinal periphery were pyriform in soma shape while dendritic fields were found or oval covering an area of 0.18 +/- 0.05 mm2 (510 +/- 80 microns in diameter). Cell density in this region was about 32 cells/mm2 and, therefore, their dendritic field coverage was approximately 6.0.

Animals↗

Developmental changes in the volumes, protein, and some electrolyte concentrations of male and female rat submandibular saliva secreted in response to methoxamine and pilocarpine.

Saliva secreted in response to methoxamine and pilocarpine was collected from the cannulated ducts of the submandibular glands of male and female rats at weekly intervals from two to 10 weeks of age. It was analyzed for volume and for concentrations of protein, potassium, calcium, and inorganic phosphate. Following the collection of saliva, the submandibular glands were removed and weighted. The wet weights of the glands increased substantially up to seven weeks of age and then reached almost plateau values in both sexes. The salivary volumes secreted in response to both agents in both sexes were positively correlated with the gland weights, except that after five to six weeks of age there was no correlation between gland weight and methoxamine-stimulated salivary volume. The concentrations of protein, potassium, and inorganic phosphate were inversely related to the flow rates only at relatively low rates of flow. The concentration of calcium was positively correlated with the protein concentration and was independent of the nature of the stimulus and of sex differences during postnatal development.

Animals↗