Biomedical subjects

T Kohama

Publications and source records attributed to T Kohama.

At least 55 records · Page 3Linked to original sources

PubMed1993

Novel microbial metabolites of the phoslactomycins family induce production of colony-stimulating factors by bone marrow stromal cells. II. Isolation, physico-chemical properties and structure determination.

Leustroducsins (LSNs) A, B and C, novel inducers of colony-stimulating factors (CSFs), were isolated from culture broth of Streptomyces platensis SANK 60191 mainly by ethyl acetate extraction and preparative reverse-phase HPLC. The molecular weights and molecular formulae of LSNs A, B and C are 641: C32H52O10NP, 669: C34H56O10NP and 669: C34H56O10NP, respectively. The structure elucidation revealed that they belong to the phoslactomycin group antibiotics, and their structures contain an alpha,beta-unsaturated delta-lactone, an amino group, a phosphate ester and a cyclohexane ring moiety. The structures differ only at the substituent bound to the cyclohexane ring.

Bone Marrow↗

PubMed1992

[Vesical ultrasonography and internal examination of female patients with urethral syndrome].

Transabdominal ultrasonography of the bladder and internal examination were performed in 80 female patients without pyuria. They were divided into 3 groups: urethral syndrome with trigonitis (49 cases), asymptomatic trigonitis (16 cases) and normal bladder (15 cases) by cystoscopy. Ultrasonography of trigonitis with or without symptoms showed focal dilation of the submucosal low echo zone and mucosal irregularity around the bladder neck. On the sagittal view, the thicknesses from the surface of mucosa to that of muscle layer within 2 cm from the bladder neck were 4 +/- 1 mm (mean +/- standard deviation) in the group with urethral syndrome and in that with asymptomatic trigonitis, and 3 +/- 1 mm in the normal bladder group. Mucosa of the trigonitis with or without symptom is patients with significantly thicker than that of those with normal bladder (p less than 0.01). On internal examination, tenderness at the upper frontal wall of the vagina was present in 10 of 11 cases (91%) with urethral syndrome, in 2 of 8 cases (25%) with asymptomatic trigonitis and in one of 9 cases (11%) with normal bladder. There was a significant difference (p less than 0.005) between the degree of inflammation and the number of cases with tenderness at the frontal wall of the vagina. From these results, transabdominal ultrasonographic measurement of mucosal thickness around the bladder neck and internal examination for tenderness at the frontal wall of vagina are thought to be useful methods for diagnosis and follow-up of urethral syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

[Neuroanatomical studies on the urine storage facilitatory areas in the cat brain. Part I. Input neuronal structures to the nucleus locus subcoaruleus and the nucleus radicularis pontis oralis].

Input neuronal structures to the nucleus locus subcoeruleus (LSC) and the nucleus reticularis pontis oralis (PoO) were investigated by the horseradish peroxidase (HRP) study in cats. Under halothane anesthesia, a double barreled electrode was inserted into the LSC where electrical stimulation increased bladder capacity and the external urethral sphincter muscle activity, and into the PoO where chemical stimulation with carbachol increased bladder capacity and decreased the external urethral sphincter muscle activity. After identification of these regions, the HRP was ionphoretically injected into the LSC or PoO. By injecting the HRP into the LSC, retrogradely HRP labeled cells were located broadly in the frontal, rectal, orbitalis, rostral cingulate, internal aspect of posterior sigmoidal and anterior sylvian gyli, nucleus corticomedialis of amygdala, lateral area of the hypothalamus, paraventricular hypothalamic nucleus, substantia nigra, periaqueductal gray, reticular formation of the mesencephalon, pons and medulla, cerebellar nuclei and intermediate gray of the spinal cord. By injecting the HRP into the PoO, retrogradely HRP labeled cells were located broadly in the frontal, rectal, orbitalis, internal aspect of the posterior sigmoidal and anterior sylvian gyli, lateral area of the hypothalamus, paraventricular hypothalamic nucleus, periaqueductal gray, reticular formation of the mesencephalon, pons and medulla, cerebellar nuclei and intermediate gray of the spinal cord. These areas where HRP labeled cells were located mostly corresponded to the areas where electrical stimulation evoked either bladder relaxation or contraction in the previous reports. The LSC and the PoO seem to perform important roles in the neuronal mechanism for urine storage, receiving the inputs which facilitate or inhibit micturition from the extended areas between the cerebral cortex and the sacral spinal cord.

Animals↗

PubMed1992

[Neuroanatomical studies on pontine urine storage facilitatory areas in the cat brain. Part II. Output neuronal structures from the nucleus locus subcoeruleus and the nucleus reticularis pontis oralis].

Output neuronal structures from the nucleus locus subcoeruleus (SLC) and the nucleus reticularis ponts roalis (PoO) were investigated by the wheat germ agglutinin-horseradish peroxidase (WGA-HRP) study in cats. Under halothane anesthesia, a double-barreled electrode was inserted into the LSC, PoO. After identification of these regions, the WGA-HRP was injected ionphoretically into the LSC or PoO. WGA-HRP labeled fibers were observed from the hypothalamus to the sacral spinal cord. Fiber connection was assumed between the WGA-HRP injection sites and areas where WGA-HRP labeled cells were located. There were input and output relationships between the LSC, the PoO and the nucleus locus coeruleus alpha which is the pontine micturition center. By injecting the WGA-HRP into the LSC, two major rostral pathways and four major caudal pathways from the LSC were recognized. Two short caudal pathways projected into the cerebellum and the nucleus raphe magnus. Two long caudal pathways passed through the ipsilateral ventral and contralateral funiculi, and projected into the sacral intermediate gray and the Onuf's nucleus. By injecting the WGA-HRP into the PoO, two major rostral pathways and four major caudal pathways from the PoO were recognized. Three short caudal pathways projected into the cerebellum, contralateral reticular formation of the brain stem and the ipsilateral nucleus reticularis gigantocellularis. One long caudal pathway passed through the ipsilateral ventral funiculus and projected into the sacral intermediate gray and the Onuf's nucleus. From these results, the LSC and the PoO seem to send and receive outputs and inputs each other and to integrate the informations.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

[Effect of YM-12617 (amsulosin hydrochloride) on lower urinary tract function in the female decerebrate dog].

The effect of YM-12617 on the lower urinary tract function was studied by combined recording of cystometry and external sphincter electromyogram (EMG) in 11 female decerebrate dogs. Reflex micturitions were induced by bladder filling before and after YM-12617 administration. Statistical analysis was carried out on the urodynamic parameters. YM-12617 in a dose of 10 micrograms/kg significantly decreased micturition threshold pressure during the collecting phase. In the urodynamic parameters of the emptying phase there was a significant decrease in contraction pressure at 10 and 30 micrograms/kg.

Adrenergic alpha-Antagonists↗

PubMed1991

The primary structure of Aspergillus niger acid proteinase A.

The complete amino acid sequence of the acid proteinase A, a non-pepsin type acid proteinase from the fungus Aspergillus niger var. macrosporus, was determined by protein sequencing. The enzyme was first dissociated at pH 8.5 into a light (L) chain and a heavy (H) chain, and the L chain was sequenced completely. Further sequencing was performed with the reduced and pyridylethylated or aminoethylated derivative of the whole protein, using peptides obtained by digestions with Staphylococcus aureus V8 protease, trypsin, chymotrypsin, and lysylendopeptidase. The location of the two disulfide bonds was determined by analysis of cystine-containing peptides obtained from a chymotryptic digest of the unmodified protein. These results established that the protein consists of a 39-residue L chain and a 173-residue H chain that associate noncovalently to form the native enzyme of 212 residues (Mr 22,265). This is, to our knowledge, the first time that such a protein with a rather short peptide chain associated noncovalently has been found. No sequence homology is found with other acid or aspartic proteinases, except for Scytalidium lignicolum acid proteinase B, an enzyme unrelated to pepsin by sequence, which has about 50% identity with the present enzyme. These two enzymes, however, are remarkably different from each other in some structural features.

Amino Acid Sequence↗

PubMed1991

[Experimental and clinical studies of urethral anesthesia on etiology and treatment of detrusor-sphincter dyssynergia].

We studied whether detrusor-sphincter synergia during micturition was obtained by means of urethral anesthesia with lidocaine hydrochloride in five thoracic spinal cats and eight clinical cases with detrusor-sphincter dyssynergia. In thoracic spinal cats with detrusor-sphincter dyssynergia, urethral anesthesia produced detrusor-sphincter synergia, an increase in the maximum bladder pressure and a decrease in the residual volume. In clinical cases with detrusor-sphincter dyssynergia, urethral anesthesia produced detrusor-sphincter synergia or a decrease in the external urethral sphincter activities during micturition, and a decrease in the maximum urethral closure pressure and the residual volume. There were no remarkable changes of the external urethral sphincter activities during urine storage phase before and after urethral anesthesia in both spinal cats and clinical cases. These results suggest that urethral anesthesia blocks the urethro-urethral contraction reflex and secondarily activates vesico-urethral relaxation reflex. The block of urethral sensory nerves is thought to effectively treat detrusor-sphincter dyssynergia.

Anesthesia, Local↗

PubMed1991

[Identification of effective region of the pons in response to inaperisone which facilitates urine storage].

To identify the effective region of the pons in response to inaperisone which facilitates urine storage, inaperisone (100 mM, 0.2 microliters) was injected into the nucleus locus coeruleus alpha (LCa, the pontine micturition center), the nucleus locus subcoeruleus (LSC, the pontine urine storage center) and the nucleus reticularis pontis oralis (PoO, micturition inhibitory region) of the decerebrate cats. On reflex micturition, inaperisone injection into the LSC decreased voiding volume, and increased residual volume and bladder capacity, significantly. However, there was no difference in the maximum bladder pressure before and after inaperisone injection into the LSC. Inaperisone injection into the LCa or the PoO had no influence on reflex micturition. These results suggest that effective region of the pons in response to inaperisone is the LSC, and that inaperisone facilitates the urine storage neural mechanism in the LSC.

Animals↗

PubMed1991

[Non-invasive imaging diagnosis of left renal vein compression causing hematuria. Part 1. Ultrasonography].

Left renal veins of 100 out-patients were examined by transabdominal ultrasonography to evaluate its usefulness in determining left renal vein compression which is causing renal bleeding. Ultrasonography revealed the left renal vein in 86 patients. In 61 of the 86 cases, the internal cavity of left renal vein was opened at least in diastolic phase, but in 23 cases, the internal cavity was closed between the abdominal aorta and the superior mesenteric artery in both systolic and diastolic phases. In the remaining 2 cases, left renal vein was compressed at a point where it intersected the right renal artery. Left renal vein compression was observed in 18 (69%) of the 26 cases which had been classified as idiopathic renal bleeding and in 7 (26%) of the 27 cases which had urinary tract diseases causing hematuria. In 33 cases which did not have hematuria, left renal vein compression was not observed. These results suggest that diagnosis of left renal vein compression causing renal bleeding is possible by transabdominal ultrasonography.

Adolescent↗

PubMed1991

[Non-invasive imaging diagnosis of left renal vein compression causing hematuria. Part 2. CT].

Left renal veins of 77 patients were examined by computed tomography (CT) to evaluate its usefulness in determining the left renal vein compression which is causing renal bleeding. From CT image, left renal vein compression was observed in 6 (86%) of the 7 cases which had been classified as idiopathic renal bleeding, in 9 (21%) of the 42 cases which had urinary tract diseases causing hematuria, and in 3 (11%) of the 28 cases which did not have hematuria. In 15 of the 18 cases of left renal vein compression, left renal vein was compressed between the superior mesenteric artery and the abdominal aorta, showing so-called nutcracker phenomenon. In the remaining 3 cases, however, the superior mesenteric artery provided sharp delineation from the abdominal aorta. The superior mesenteric artery and the abdominal aorta made the mean angle of 35.5 degree in patients with normal left renal vein, the mean angle of 45.4 degrees in those with left renal vein compression without nutcracker phenomenon, and the mean angle of 11.9 degrees in those with nutcracker phenomenon. CT was superior to ultrasonography, in revealing left renal vein compression.

Adult↗

PubMed1991

Plaque formation of Newcastle disease virus in primary chicken kidney cells.

Using primary chicken kidney (PCK) cells, a plaque assay was carried out with an avirulent strain of Newcastle disease virus (NDV) without adding trypsin to the agar overlay medium. The plaque assay was done in less than 4 days in PCK cells, by 3 days earlier than in primary chicken embryo (CE) cells maintained in the presence of trypsin. The curves of the progeny virus production began to rise 6 h after the infection and reached a plateau at 12 h. Equal amounts of virus were produced in PCK cells both in the presence and absence of trypsin in the culture medium. Viral peptide analysis revealed that a large portion of the HN and F precursor envelope glycoproteins of the NDV-Ulster strain remained uncleaved in PCK-grown virions. This suggests that a marginal proteolytic cleavage of these glycoprotein suffices for the full growth of the progeny virus in PCK cells. A higher shut-off in the host protein synthesis occurred in the virus-infected PCK cells than in the infected CE cells.

Animals↗

PubMed1990

Quantitative analysis of serum alpha 1-acid glycoprotein levels in normal and diabetic pregnancy.

In an attempt to clarify the mechanism of lipid metabolism during pregnancy, alpha 1-acid glycoprotein (alpha 1-AG) was analyzed in normal and diabetic pregnant women. Seventy-two determinations of serum alpha 1-AG levels were performed in 18 diabetic pregnant women and 82 determinations in 82 normal pregnant women in all three trimesters and within 14 days postpartum. Serum alpha 1-AG levels in both normal and diabetic pregnant women decreased throughout pregnancy and rapidly increased postpartum. In all gestational stages, the serum alpha 1-AG levels were lower in diabetic women than in normal women, but the differences were not significant. No significant correlation was obtained between serum alpha 1-AG and hemoglobin A1 (HbA1) in diabetic patients. On the contrary, the serum triglyceride levels increased during pregnancy and decreased postpartum in both groups of subjects. These findings suggest that serum alpha 1-AG plays an important role in the activation of lipoprotein lipase during pregnancy.

Adult↗

PubMed1990

Monoclonal antibodies to three structural proteins of Newcastle disease virus: biological characterization with particular reference to the conformational change of envelope glycoproteins associated with proteolytic cleavage.

Monoclonal antibodies (MAbs) to the haemagglutinin-neuraminidase (HN), fusion (F) and matrix (M) proteins of Newcastle disease virus were prepared and characterized. At least three non-overlapping or partially overlapping antigenic sites were delineated on the HN, three on the F and three on the M proteins by competitive binding assays. Antigenic sites on the HN and F proteins roughly represented functional domains defined by serological tests. Two antigenic sites on the F protein were involved in virus neutralizing and haemolysis-inhibiting activity. These antigenic determinants were readily affected by treatment with certain surfactants and acetone. Proteolytic cleavage of the HN and F proteins was associated with conformational change, revealed by altered reactivity with MAbs and by altered topological arrangements of some epitopes. None of the anti-M MAbs inhibited any biological activities of the virus.

Animals↗

PubMed1990

Protective effect of monoclonal antibodies to Newcastle disease virus in passive immunization.

A series of monoclonal antibodies (MAbs) against the haemagglutinin-neuraminidase (HN) and fusion (F) glycoproteins and the matrix (M) protein of Newcastle disease virus (NDV) were tested for protective effects in passive immunization of newborn chickens against challenge with a virulent heterologous strain of NDV (Italien). MAbs with high virus-neutralizing activity directed to one antigenic site of the HN protein delayed virus growth and significantly prolonged survival time, but all chickens eventually succumbed to infection. MAbs directed to two antigenic sites of the F protein completely suppressed virus growth and prevented death of chickens, although the neutralizing activities of these anti-F MAbs were lower than those of the above anti-HN MAbs. Combined administration of the anti-HN and anti-F MAbs had a synergistic protective effect, but no protective effects were shown by MAbs against the M protein.

Animals↗

PubMed1990

Elevation of immunoreactive platelet prostaglandin E and plasma prostaglandin F2 alpha in diabetic pregnancy.

Platelet prostaglandin (PG) E and plasma PGF2 alpha concentrations were measured by radioimmunoassay methods and compared in non-pregnant and pregnant, normal and diabetic subjects. The blood samples were obtained in the follicular phase in the non-pregnant women and in the third trimester and after delivery in the pregnant women. The immunoreactive platelet PGE (IRPGE) levels were significantly higher in the pregnant diabetic women than in the normal non-pregnant and pregnant women and diabetic non-pregnant women. The immunoreactive plasma PGF2 alpha (IRPGF2 alpha) concentrations were significantly higher in the non-pregnant diabetic women than in the normal non-pregnant and pregnant women. During pregnancy, the plasma IRPGF2 alpha were further increased significantly in the diabetic subjects compared to the non-pregnant diabetics. Both the platelet IRPGE and plasma IRPGF2 alpha concentrations were higher in the pregnant diabetic subjects with retinopathy than in those without retinopathy. These findings suggest that pregnancy and diabetes influence the synthesis of PGE and PGF2 alpha in the platelets and plasma, respectively. The increased production of these prostaglandins are possible exacerbating factors of diabetic retinopathy during pregnancy.

Adult↗

PubMed1990

[Effects of trospium chloride on the lower urinary tract function].

The effects of trospium chloride on the lower urinary tract function were studied by combined recording of cystometry and sphincter electromyogram in 13 decerebrated dogs. Micturition was induced by bladder filling before and after drug administration. A statistical analysis was carried out on the urodynamic parameters. Trospium chloride at the dose of 0.1 mg/kg showed a small but significant decrease in the threshold pressure during the collecting phase. In the urodynamic parameters of the emptying phase which is considered to be influenced by cholinergic activity, there was a significant decrease in maximum bladder pressure at 0.03, 0.1, and 0.3 mg/kg and a significant increase in residual urine at 0.3 mg/kg. Trospium chloride is probably acting as a antimuscarinic agent in this study. Trospium chloride appears to be useful for the relief of symptoms associated with hyperactive bladder contraction.

Animals↗

PubMed1989

A measles virus subgenomic RNA: structure and generation mechanism.

A plaque-derived line of measles virus induced the synthesis of 21S subgenomic RNA in addition to 50S genomic RNA. The nucleotide sequence of the former RNA was determined in comparison with that of the latter. The 21S subgenomic RNA was 2646 nucleotides long and had a copyback structure containing a 50S genomic 5'-end. At the site where copying turns back, there was a 15-nucleotide-long sequence resembling the "measles virus consensus sequence" which is present at the beginning of each gene on the measles virus genome and is presumed to serve as a signal for the initiation of transcription. Recognition of the specific sequence may have been involved in the aberrant replication and may represent an additional and novel copy choice mechanism leading to the generation of subgenomic RNAs.

Base Sequence↗

PubMed1989

Protective role of human antibody to the fusion protein of measles virus.

Absorption of a pooled human gamma globulin preparation with acetone-treated measles virus-infected cells removed all antibodies to measles virus antigens except a portion of the antibody to the fusion (F) protein. The residual anti-F antibody had hemolysis-inhibiting and virus-neutralizing activities, inhibited spread of infection through cell fusion, and was effective in protection of passively immunized mice from fatal measles encephalitis, providing evidence for the protective role of human antibody to the F protein of measles virus.

Acetone↗