Biomedical subjects

T Katayama

Publications and source records attributed to T Katayama.

At least 199 records · Page 11Linked to original sources

PubMed1994

Pathophysiologic significance of free and conjugated dopamines in congestive heart failure.

sulfoconjugated dopamine constitutes the major portion of circulating or excreted dopamine, but its physiologic significance is still unknown. To test whether conjugated dopamine serves as a source of free dopamine in response to acute stress, plasma concentrations of free and conjugated dopamine were measured during an acute exacerbation of heart failure. The plasma concentration of conjugated dopamine decreased significantly during the acute phase of heart failure, whereas that of free dopamine increased. The plasma concentration of free dopamine decreased, whereas the concentration of conjugated dopamine increased as heart failure improved. An infusion of dopamine increased the plasma concentration of conjugated dopamine, suggesting that at least part of the excess active dopamine was detoxified through conjugation. The results of these tests with both conjugated and free dopamine are interconvertible and indicate that conjugated dopamine can serve as a reservoir of active dopamine.

Adult↗

PubMed1994

Two distinct pathways of specific killing revealed by perforin mutant cytotoxic T lymphocytes.

To study the contribution of putative perforin-independent mechanism in the antigen-specific target destruction by cytotoxic T lymphocytes CD8+ CTL lines were established from spleen cells of chimeric mice produced by injecting perforin (-/-) embryonic stem cells into blastocysts of RAG-2(-/-) mice. When tested on normal concanavalin A blasts, these perforin-deficient cytotoxic T lymphocyte lines were found to be capable of inducing antigen-specific target cell lysis accompanied by DNA degradation. In contrast, with target cells carrying a mutation in Fas molecule, perforin-independent cytotoxicity was not detectable. These data not only confirmed the primary role of perforin but simultaneously revealed a major contribution of a perforin-independent Fas-mediated pathway in antigen-specific cytolysis.

Animals↗

PubMed1994

Expression and characterization of human bone morphogenetic protein-2 in silkworm larvae infected with recombinant Bombyx mori nuclear polyhedrosis virus.

Recombinant human bone morphogenetic protein-2 (rhBMP-2) was expressed in silkworm larvae, and a milligram quantity of the protein was purified and characterized. The expressed rhBMP-2 was biologically active in terms of induction of alkaline phosphatase activity in MC3T3-E1 cells and ectopic bone formation in mice. On SDS-polyacrylamide gel electrophoretic analysis, the purified protein showed a 16 kDa band under reducing conditions and a 30 kDa band under non-reducing conditions. The silkworm-expressed rhBMP-2 was glycosylated and susceptible to endo-beta-N-acetylglucosaminidase F (endo F) and endo H, but resistant to endo D. Deglycosylated rhBMP-2 treated with endo F retained its biological activity. These results suggest that rhBMP-2 exists as a dimer and disulfide bond(s) are responsible for the dimerization. Moreover, sugar chains have no direct effect on the biological activity of the protein. The availability of a quite large amount of rhBMP-2 has allowed us to study the biological function of this interesting factor in detail.

3T3 Cells↗

PubMed1994

Augmentation of host resistance against bacterial infection by treatment with leustroducsin B, a new CSF inducer.

We tested the in vivo activity of leustroducsin B (LSN B), a new colony-stimulating factor (CSF) inducer isolated from the culture broth of Streptomyces platensis, with mice infected with Escherichia coli. Treatment with LSN B augmented the host resistance to lethal infection of E. coli at doses between 0.1 mg/kg and 1 mg/kg. Serum interleukin-6 (IL-6) levels were found to increase after this treatment, and superoxide anion generation of neutrophils was enhanced in vivo, suggesting that LSN B augmented the host resistance at least in part by inducing IL-6, which subsequently enhanced the bactericidal activity of the neutrophils.

Animals↗

PubMed1994

[Serotype-specific amplification of Rickettsia tsutsugamushi DNA from clinical specimens by nested polymerase chain reaction].

Polymerase chain reaction (PCR) with nested primer pairs was used to diagnose Tsutsugamushi disease and identify the Rickettsia tsutsugamushi serotype. The primer pairs used for PCR were designed on the basis of the nucleotide sequence of the gene that encodes the 56-kDa antigen. Five serovariants, the Gilliam, Karp, Kato, Kawasaki, and Kuroki strains of Rickettsia tsutsugamushi were detected and identified by nested PCR. The serotypes of patients registered during 1990 to 1992 in Kanagawa Prefecture were identified by nested PCR. Sixty percentage of patients showed Kawasaki types, 20% Karp types, and 20% Kuroki types. This result suggested that the recent Tsutsugamushi disease were mostly caused by Kawasaki types in Kanagawa Prefecture.

DNA Primers↗

PubMed1994

Epidermal growth factor concentrations in seminal plasma from patients with hypogonadism--changes after hormone replacement.

Epidermal growth factor (EGF) content in seminal plasma of 17 patients with androgen deficiency (12 Klinefelter's syndrome and 5 hypogonadotropic hypogonadism) was determined before and after hormone replacement. No significant increase of plasma testosterone level was demonstrated after testosterone administration in Klinefelter's syndrome, although the level in 4 of 5 patients with hypogonadotropic hypogonadism reached the normal range. In 16 patients, except 1 with hypogonadotropic hypogonadism with no increase of blood testosterone level, prostate volume increased after hormone therapy, and volumes after treatment were significantly larger than those before treatment. On the other hand, EGF concentration in seminal plasma remained at the pretreatment level in most patients. It is therefore concluded that although the prostate volume increases to almost normal after treatment, prostate function does not improve in most patients, indicating that in patients with hypogonadotropic hypogonadism fertility potential may remain low, even if they obtain normal seminal parameters after treatment.

Adult↗

PubMed1994

A case of oncocytoma in the eyelid.

Oncocytoma rarely arises from the eyelid and only 2 cases have been reported previously. We present a case of oncocytoma in the upper eyelid around the lacrimal punctum. Anatomical location and histological findings suggested that oncocytes of this tumor originated from the epithelium of Moll's gland or the lacrimal canaliculus.

Adenoma, Oxyphilic↗

PubMed1994

Immunohistological studies of an oncocytoma.

An oncocytoma of the upper eyelid that occurred in an 82-year-old male was studied immunohistologically according to the avidin-biotin-peroxidase complex method (secretory component, carbohydrate antigen 19-9, carcinoembryonic antigen, anticytokeratin AE1/AE3, S-100 protein, myoglobin, actin, vimentin). The staining properties of columnar-type oncocytes were the same as those of epithelial cells of excretory ducts of Moll's gland, but those of polygonal-type oncocytes were similar to those of myoepithelial cells of Moll's gland. Our results suggested that excretory duct epithelial cells of Moll's gland are the origin of oncocytoma of the eyelid.

Adenoma, Oxyphilic↗

PubMed1994

Activin modulates the intracellular signaling system activated by gonadotropin-releasing hormone: dual effect on calcium messenger system and protein kinase-C pathway.

This study was performed to assess the effects of activin on intracellular mechanisms involved in GnRH action. When rat pituitary cell cultures were pretreated with activin-A (5-80 ng/ml) for 3 days, subsequent FSH and LH release (percentage of total cellular FSH and LH released during 4 h) in response to GnRH (10(-10)-10(-6) M) was not significantly different from that in cells pretreated with medium alone. In contrast, activin pretreatment increased the potency of both A23187 (Ca2+ ionophore) and phorbol 12-myristate 13-acetate [a protein kinase-C (PKC) activator] as secretagogues for FSH and LH release. FSH or LH release in response to another Ca(2+)-mobilizing secretagogue, maitotoxin (an activator of the GnRH receptor-associated Ca2+ channel), was not increased by activin. Although PKC is capable of influencing the actions of Ca2+, which is believed to be the second messenger for GnRH action, neither GnRH- nor maitotoxin-stimulated gonadotropin release was increased by activin even when the influence of activin on PKC was eliminated by the addition of a PKC inhibitor (staurosporine; 100 nM) during the final 30 min of the 3-day pretreatment period. These results indicate that although activin does not influence GnRH action with regard to gonadotropin release, it increases the sensitivity of the system regulating gonadotropin release to increases in cytosolic Ca2+ concentrations and PKC activation. Furthermore, activin appears to exhibit an inhibitory effect(s) at some point(s) in GnRH action in a PKC-independent manner, which could be responsible for opposing the increased sensitivity of the gonadotrope to Ca2+. The differential effects of activin on gonadotropin release in response to Ca(2+)-mobilizing secretagogues (ionophore and maitotoxin) raise the possibility that the activity of the GnRH receptor-associated Ca2+ channel may be suppressed by activin.

Activins↗

PubMed1994

Guillain-Barré syndrome with bilateral tonic pupils.

A 53-year-old patient with Guillain-Barré syndrome preceded by herpes simplex virus infection developed bilateral tonic pupils with light-near dissociation. Pharmacological tests for pupils suggested postganglionic involvement of the parasympathetic and sympathetic nerves. A demyelinating process of peripheral autonomic nerves was suspected to be the cause of the tonic pupils and autonomic dysfunction.

Epinephrine↗

PubMed1994

Serial electrocardiographic findings in acute myocarditis.

The purpose of the present study was to clarify the characteristic findings of electrocardiogram (ECG) in 11 patients with acute myocarditis. ST elevation without reciprocal ST depression was one of the conspicuous findings in the acute stage. Total QRS amplitudes at the acute stage were significantly decreased as compared to those before illness and during the convalescent stage. Abnormal Q waves were present in 7 patients and disappeared in a short period. The number of leads showing Q waves was inversely correlated to left ventricular (LV) ejection fraction (r = -0.87, p < 0.01). Conduction disturbances were present in 7 patients. Second degree and advanced AV block was transient while bundle branch block remained over months. Corticosteroid treatment was effective for patients who had edematous myocardial thickening and AV conduction disturbances. As the serial ECG findings in acute myocarditis are so characteristic, and this help to differentiate it from acute myocardial infarction (AMI).

Acute Disease↗

PubMed1994

[Studies of transrectal prostatic ultrasonography on patients with male infertility].

The diagnostic significance of transrectal prostatic ultrasonography for chronic prostatitis and varicocele was evaluated in 380 male infertility patients. Of 20 patients with pyospermia, thought to be mainly caused by chronic prostatitis, 10.0 percent showed heterogeneous echo pattern of the prostate, while 25.0 percent showed capsular irregularity. Since 285 patients with non-infected semen showed similar sonographic findings, it is concluded that prostatic ultrasonography has little value in the diagnosis of chronic prostatitis in infertile patients. Enlarged periprostatic echo-free zone, thought to coincide with the dilatation of the Santrini's plexus, was found in 42.9 and 42.7 percent of patients with chronic prostatitis and varicocele, respectively, in contrast to 34.0 percent of patients without either diseases. Twelve percent of patients with varicocele showed highly enlarged echo-free zone, which was significantly more frequent compared to 5.0 percent in normal patients. Moreover, follow up of 4 patients with varicocele pre- and post-operatively found 2 of them to show a great improvement in the enlargement of the zone. These results suggest that varicocele may cause the dilation of the Santrini's plexus through a venous anastomosis in some patients and transrectal ultrasonography may be a useful tool in detecting small varicoceles in such patients.

Chronic Disease↗

PubMed1994

[Experience of a double Malecot polyurethane intraurethral catheter in patients with dysuria].

We reviewed our experience of using double Malecot polyurethane intraurethral catheters (IUC). Ten patients with dysuria were treated between April 1991 and April 1993. Seven patients with benign prostatic hypertrophy (BPH) were judged as in a high risk group for operation. The three other patients had neurogenic bladder (two had underactive bladder and 1 had overactive bladder). Under local anesthesia, 150 ml of 0.1% Povidone iodine solution was infused into the bladder through a Nelaton catheter. Under guidance by ultrasonography, an IUC was placed into the bladder neck and posterior urethra using the specially designed introduction set. An long-term follow up of the BPH patients, two IUCs were removed for operation and one was exchanged for an indwelling catheter because of deterioration in general condition. In the neurogenic bladder patients, all IUC were removed because of the increase of residual urine, formation of a pseudourethra, or dislocation into the bladder. Side effects were observed in 6 patients such as, urethral bleeding and stone formation in the stent. Erosion and bleeding tendency in the urethral mucosa were shown in the prolonged duration cases. We conclude that a urethral stent is an effective devise for a high risk patient with benign prostatic hypertrophy but we must keep each patient under strict observation for complications during IUC placement.

Aged↗

PubMed1994

[Efficacy of PCR-microwell plate hybridization method (Amplicor Mycobacterium) for detection of M. tuberculosis, M. avium and/or M. intracellulare in clinical specimens].

Recently, a new kit to detect and identify mycobacteria in clinical specimens was developed by Japan Roche Co. Limited. The new method is based on amplification of DNA of mycobacteria in clinical specimens by PCR and hybridization of amplified DNA by microwell plate hybridization method, which is the "Amplicor Mycobacteria, Roche, (AMP-M)". Cooperative study was organized with 15 tuberculosis hospitals and institutions throughout Japan, and 349 clinical specimens from newly admitted tuberculosis patients and/or suspects were collected during July and August, 1993. All the specimens were examined by smear microscopy (Ziehl-Neelsen's staining), culture on Ogawa egg media, culture on variant 7H9 liquid media and by AMP-M. Excluding 25 specimens which had failed to identify the species of mycobacteria because of contamination, disability to multiply on the transplanted solid media and so on, the results of the examinations in 324 specimens consisting of 167 specimens from previously untreated cases and those of 157 specimens from previously treated cases were analysed. Main results obtained were as follows; 1. Of 70 smear positive specimens from previously untreated cases, culture positive on Ogawa media and 7H9 media, and by AMP-M positive were 59 (84.3%), 61 (87.1%) and 66 (94.3%), respectively. Of 97 smear negative specimens, culture positive were 20 (20.6%), 22 (22.7%) and 27 (27.8%), respectively. The AMP-M showed the highest positive rate in both groups. 2. The sensitivity and the specificity of AMP-M in previously untreated cases were calculated by assuming that positive on Ogawa and/or variant 7H9 media is "positive". The sensitivity was 95.8% (68/71) and the specificity was 94.8% (91/96) for M. tuberculosis in previously untreated cases. The sensitivity and the specificity for M. avium and M. intracellulare were all 100%, although the numbers observed were small. 3. So-called false positive of the AMP-M were observed in 5 cases out of 96 culture negatives on both Ogawa and variant 7H9 media. However, all 5 cases were positive by repeated AMP-M, 3 become culture positive later, and another 2 showed clinical findings consistent with tuberculosis. Hence, the authors considered that the false positive rate of the AMP-M method is to be very low in previously untreated cases. 4. Of 86 smear positive cases with history of previous chemotherapy, the positive culture on Ogawa media, variant 7H9 media and that by AMP-M method were 64 (74.4%), 77 (89.5%) and 85 (98.8%), respectively. In the smear negative cases, culture positive was 10 out of 71 (14.1%), 13 (18.3%) and 24 (33.8%), respectively.

DNA, Bacterial↗

PubMed1994

[Clinical study on renal pelvic and ureteral tumors].

Thirty five patients with renal pelvic and ureteral tumors were treated at our hospital between 1979 and December 1992. Thirty patients were male and five were female. They ranged in age from 44 to 80 years old (average 67.4 years). The most frequent symptoms were hematuria that was found in 31 cases (24 gross hematuria and 7 microscopic hematuria). Histopathologically, there were 30 transitional cell carcinomas (TCC), 1 squamous cell carcinoma (SCC), 2 TCC > SCC and 1 papillary adenocarcinoma. As to staging, 1 was pTis, 5pTa, 11pT1, 3pT2, 11pT3 and 4pT4. As to grading, 9 were G1, 16 G2 and 9 G3. The incidence of cancerous vessel invasion was noted in 8 of the 29 patients. The 5-year survival rate (Kaplan-Meier's method) was 44.9% for all of the patients. The 5-year survival rate according to staging and according to grading were as follows: 76.7% for low stage (pTis, pTa, pT1, pT2), 24.9% for high stage (pT3, pT4), and 83.3% for G1, 59.9% for G2 and 0% for G3. The 5-year survival rate was 20.8% and 68.7% in the patients with and without vessel invasion, respectively. Grade, stage and cancerous vessel invasion was suggested to be associated with the prognosis in renal pelvic and ureteral tumors.

Adenocarcinoma, Papillary↗

PubMed1994

[The pulmonary air meniscus sign in a case of sclerosing hemangioma].

A 57-year-old woman was admitted to our hospital because of a slowly growing pulmonary tumor with a 34 year history. Chest roentgenogram on admission showed a 42 mm sharply demarcated solitary tumor in the left upper lobe. Chest CT revealed a slit-like pulmonary air meniscus. Left upper lobectomy was performed. A specimen from the resected lung histologically showed solid, papillary and hemorrhagic patterns, and the diagnosis of pulmonary sclerosing hemangioma was therefore made. Pulmonary air meniscus sign in pulmonary sclerosing hemangioma is rare. We think one possible mechanism in the production of an air meniscus sign in sclerosing hemangioma is bleeding in communication with a bronchus.

Female↗

PubMed1994

[Clinical efficacy of sairei-to in various urinary tract diseases centering on fibrosis].

A joint multi-institution study was conducted on the efficacy of Sairei-to, centering on urinary tract fibrosis. The subjects consisted of 18 patients with retroperitoneal fibrosis (including 3 women), 77 patients with plastic induration of penis, 5 patients with sclerotic lipogranuloma (all men), and 67 patients with hemorrhagic cystitis (including 6 men). As a rule, Sairei-to was administered in monotherapy for periods of 4 weeks or longer. Efficacy was most pronounced in the patients with sclerotic lipogranuloma and plastic induration of penis, with overall improvement rates (percentage of patients with ratings of effective or better) of 80% in the former and 77.9% in the latter group. The overall improvement rate in the patients with retroperitoneal fibrosis was 61.1%. In the above diseases, there were numerous patients concurrently administered drugs such as antiinflammatory enzyme preparations and corticoid preparations, and the improvement rates were somewhat higher in these patients treated concurrently with other drugs. Outstanding efficacy was also seen in hemorrhagic cystitis. Dividing the patients into irradiation and non-irradiation groups, respective overall improvement rates of 77.8% and 82.8% were obtained, with the non-irradiation group showing a slightly higher rate. The non-irradiation group showed slightly higher improvement rates in the subjects treated concurrently with drugs such as antibacterial drug. Conversely, the irradiation group showed significantly superior rates for monotherapy. Side effects such as mild gastrointestinal disturbances were seen in only 13 of 167 patients (7.8%), and the utility of this drug in treatment of the above diseases should be held in high regard.

Adult↗

PubMed1994

[Lung pathology of cryptococcosis].

To elucidate the relationship between the clinical manifestations and pathologic findings of the lung in patients with cryptococcosis, we reviewed 14 autopsied cases of cryptococcosis. Five patients had pulmonary cryptococcosis and 9 had disseminated cryptococcosis. Patients with pulmonary cryptococcosis showed granulomatous reactions of the lung, such as fibrocaseous cryptococcoma (n = 2), discrete granuloma (n = 2), and granulomatous pneumonia (n = 1). Patients with disseminated cryptococcosis showed intracapillary/interstitial involvement (n = 2), mucoid pneumonia (n = 3), histiocytic pneumonia (n = 1), and granulomatous pneumonia (n = 3). There was a distinct difference between pulmonary cryptococcosis and disseminated cryptococcosis in lung pathology. Intracapillary/interstitial involvement and mucoid pneumonia were fatal because of extensive hematogeneous dissemination to other organs. Hilar lymph node involvement of cryptococcosis was found in all of the nine patients with disseminated cryptococcosis and in one of the five patients with pulmonary cryptococcosis. Pleural involvement of cryptococcosis was found in six of the nine patients with disseminated cryptococcosis. We conclude that the clinical manifestations of cryptococcosis are closely associated with the variety of lung pathology of cryptococcosis. Clinicians should understand the morphologic features to cope with patients with cryptococcosis.

Adult↗