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K Masuko

Publications and source records attributed to K Masuko.

At least 37 records · Page 2Linked to original sources

[Analyses of T cell clonality in mice with autoimmune sialoadenitis].

T cells are believed to be deeply involved in the pathogenesis of organ-specific autoimmune diseases. However, it remains unknown whether antigen-specific immune responses occur at the inflammatory sites in vivo. As a model of human Sjögren's syndrome, we investigated the T cell clonality of mice with autoimmune sialoadenitis, i.e. IQI/Jcl-(Saegusa et al), thymus grafted (TG) nude-(Taguchi et al), and MRL/lpr-SCID (Hayashi et al) mice; using RT-PCR-SSCP method. As a result, accumulations of distinct T cell clones were demonstrated in the salivary and lacrimal glands in these mice, without V beta restriction. Moreover, a part of the accumulating clones were commonly detected among multiple glands, suggesting the existence of a common and specific immune response probably toward autoantigen(s) expressed on the affected glands.

Animals↗

Accumulation of multiple T cell clonotypes in lungs of healthy individuals and patients with pulmonary sarcoidosis.

T cell accumulation and activation in lung may play a major role in the pathogenesis of immunologic lung diseases such as sarcoidosis. Using the combination of RT-PCR and subsequent single-strand conformation polymorphism analysis, we examined T cell clonality in lung and peripheral blood of healthy individuals (n = 5) and patients with active pulmonary sarcoidosis (n = 7). RNA was extracted from PBLs and bronchoalveolar lavage fluid cells, and converted to cDNA. PCR was performed using a set of V beta-C beta primers (V beta 1-20). Products were denatured and electrophoresed in nondenaturing 5% polyacrylamide gel. The existence of a distinct T cell clonotype was detected as a band on a smear. In both groups T cells in PBLs showed a number of clones that expanded. A significantly greater number of clones was detected in BAL compared with PBL in both groups (normal: 25.3 +/- 7.2 in PBL vs 62.8 +/- 5.2 in lung; sarcoid: 25.0 +/- 6.2 in PBL vs 90.0 +/- 6.6 in lung, mean value +/- SEM). In sarcoid lung greater numbers of clones were detected than in lungs of healthy controls (p < 0.012). These clonal expansions were observed over all the 20 V beta families examined, and were not restricted to certain V beta families. These results suggest that there are clonal expansions even in normal lung, and that in sarcoidosis, apparently, additional T cell clones using multiple V beta segments might be activated and accumulated at the site of the disease.

Adult↗

Comparison of the J beta gene usage among different T cell receptor V beta families in spleens of C57BL/6 mice.

To clarify whether there is a bias in the V-D-J combination of T cell receptor (TcR) genes, J beta gene usage has been investigated in a total of 743 TcR beta genes of V beta 2, V beta 8.2, and V beta 14 families expressed in C57BL/6 mouse spleens. Genes of TcR beta chains, amplified by a reverse transcriptase-polymerase chain reaction, were individually cloned into plasmids. Cloned genes (61 to 106), randomly selected in each respective V beta family from three different mice, were tested by means of hybridization with 12 oligo DNA probes which were designed to differentiate 12 murine functional J beta gene segments. The results are enumerated below. (1) The J beta 2.6 gene segment was found to be most frequently used (V beta 2, 19.8%; V beta 8.2, 21.2%; and V beta 14, 19.2%). In contrast, usage of the J beta 1.6 gene segment was most infrequent (V beta 2, 1.9%; V beta 8.2, 2.9%; and V beta 14, 0.5%); (2) High frequency of the J beta 2.1 gene segment and low frequency of the J beta 1.3 and J beta 1.5 gene segments were also observed; (3) The J beta 2 cluster was used in preference to the J beta 1 cluster (usages of the J beta 2 cluster: V beta 2, 67.8%; V beta 8.2, 65.9%; and V beta 14, 70.4%); and (4) These biases were generally common to all three V beta families examined and differences among individual mice were mostly small. Considering these findings, we conclude that the TcR J beta gene segments in C57BL/6 mice splenocytes are selected with a bias, but are selected independently of the V beta families.

Animals↗

Dynamic changes of accumulated T cell clonotypes during antigenic stimulation in vivo and in vitro.

It has not been known how T cell clones respond to antigenic stimulation. We applied reverse transcription polymerase chain reaction and subsequent single-strand conformation polymorphism (SSCP) analysis to monitor the kinetics of accumulated T cell clonotypes with respect to the TCR beta chain. Before exposure to an antigen, peripheral blood lymphocytes from healthy individuals exhibited smears with SSCP, indicating a heterogeneous T cell population. However, some bands were demonstrated within the smears, each corresponding to a distinct clonal accumulation. The majority of the accumulated clones were CD8+ and were stably detected over 1 year in the same individual. Next it was demonstrated that a number of clonal accumulations appeared in a diverse population after an acute infection in vivo or in cell culture with an antigen in vitro. The accumulations in vivo were demonstrated in both the CD4+ and CD8+ subsets, the latter having the longer duration of response after stimuli. On the other hand, in vitro culture with purified protein derivative induced expansions of a number of CD4+ clones throughout the culture, while CD8+ clones were shown to be induced later. There was no preferential usage of particular V beta genes in these clonotypes. Stimuli by more simple peptides could also induce clonal expansions of T cells. Therefore, with our novel experimental system, we could monitor the kinetics of T cell clonotypes induced by an antigen. This method may be applied to analyses of T cell clonality in many kinds of immune responses.

Adult↗

Hepatitis C virus antibodies, viral RNA and genotypes in sera from patients on maintenance haemodialysis.

Patients on maintenance haemodialysis in four dialysis centres were tested for markers of hepatitis C virus (HCV) infection. Antibody to HCV (anti-HCV) was detected by the second-generation enzyme immunoassay in 142 (26%) of the 543 patients and HCV RNA in 117 (22%) of whom four were without detectable anti-HCV in serum. Seventy-seven (66%) were infected with HCV of genotype II/1b, 31 (27%) with genotype III/2a and eight (7%) with genotype IV/2b, in a distribution similar to that in blood donors who carried HCV asymptomatically. Haemodialysis patients had high HCV RNA titres comparable to those of patients with chronic hepatitis C. HCV RNA was detected in 96 (26%) of the 365 patients with a history of transfusion more frequently than in 21 (12%) of the 178 without previous transfusion (P < 0.001). In transfused patients, frequencies of anti-HCV and HCV RNA increased in parallel with the duration of haemodialysis. The frequency of anti-HCV in non-transfused patients, however, did not change appreciably with the duration of haemodialysis up to 22 years. The patients with anti-HCV had a higher frequency of HCV RNA in serum than symptom-free blood donors with anti-HCV (113/142 or 80% vs 109/166 or 66%, P < 0.01) and the patients with HCV RNA had a lower frequency of elevated aminotransferase levels than blood donors with HCV RNA (5/113 or 4% vs 27/109 or 25%, P < 0.001). These results indicate that transfusion is a significant cause of HCV infection in patients on maintenance haemodialysis, and that these patients are prone to establish the HCV carrier state after infection.

Adult↗

High carrier rate after hepatitis B virus infection in the elderly.

An outbreak of hepatitis B virus infection occurred in a nursing facility; it involved 31 patients with sequelae of cerebral vascular accidents (15 men and 16 women; mean age, 77.4 +/- 9.3 yr). HBsAg disappeared within 6 mo in 9 patients and persisted during an observation period of more than 6 mo in 13; the remaining 9 patients were lost to follow-up while they carried HBsAg. Thus 13 of 22 patients followed (59%) became HBsAg carriers. We amplified a part of the S gene (436 nucleotides) with polymerase chain reaction on hepatitis B virus DNA from 12 randomly selected patients. The sequences of nine patients were the same as that of a nursing assistant who was an HBsAg carrier and suspected as the source of infection; it differed by only 1 or 2 (< 0.5%) nucleotides from those of the remaining three patients. Between the group of nine patients with transient HBV infection and the 13 patients with persistent HBV infection, we found no differences in age or sex or in parameters of nutrition or immunocompetence. These results indicate a high incidence of HBV carrier state in the elderly.

Adolescent↗

Renal cell adenomas and carcinomas in hemodialysis patients: relationship between hemodialysis period and development of lesions.

Step-sections of 96 whole kidneys from 50 chronic hemodialysis patients were subjected to a histopathological and quantitative investigation with regard to the development of renal neoplastic lesions. The range of hemodialysis duration was from 1 to 222 months. A total of 349 renal cell adenomas were found in 41 cases (82%). They were commonly multiple and present bilaterally. Renal cell carcinomas were evident in four cases (8%), with hemodialysis durations of 54, 57, 112 and 222 months. The incidence of adenomas increased in a hemodialysis duration-dependent manner, indicating a high risk of renal cell tumor development in chronic hemodialysis patients. Furthermore, acquired cystic disease of the kidney (ACDK) was also observed in 12 cases (24.0%), where the mean hemodialysis period was 143.4 +/- 48.0 months. This value was significantly longer than that of non-ACDK cases (P < 0.001). There was, however, no clear relationship between the appearance of ACDK and renal cell tumors. The present results underline the necessity for attention to possible neoplasia of the kidney in patients on long-term hemodialysis.

Adenoma↗

Hepatitis C virus infection in medical personnel after needlestick accident.

Hepatitis C virus infections in medical personnel after needlestick accidents have been documented generally by detection of seroconversion to a hepatitis C virus nonstructural region antigen, c100-3 (a marker of infection). We tested for hepatitis C virus core-derived antibodies and genomic RNA in addition to c100-3 antibody in 159 cases of needlestick exposure that did not involve patients positive for HBsAg. Of these we found 68 cases with index patients positive for both hepatitis C virus RNA and antibodies and members negative for antibodies to HCV core or c100-3 before the needlestick accidents. Seven of these medical personnel became infected with hepatitis C virus after the accidents. Their hepatitis was generally subclinical or self-limited and transient, except for one patient in whom liver enzyme elevation persisted along with the antibodies. In our study, the risk of hepatitis C virus transmission from a single needlestick accident with hepatitis C virus RNA-positive blood was 10%, considerably higher than the 4% estimated in a previous study. We found that donor blood with antibody to an hepatitis C virus core-derived peptide with enzyme-linked immunosorbent assay optical densities greater than 2.0 carried a significant risk of transmitting hepatitis C virus to needlestick victims. No hepatitis C virus seroconversions occurred in medical personnel exposed to hepatitis C virus antibody-negative or hepatitis C virus RNA-negative blood; however, one such exposure resulted in a very mild non-A, non-B, non-C hepatitis.

Health Personnel↗

Utility of venography in shunt surgery on hemodialyzed patients.

Fifty-eight examples of upper extremity venography in 40 patients undergoing or about to undergo hemodialysis and 18 normal subjects were evaluated. In the normal subjects, tools and conditions of venography were investigated. It was considered necessary to maintain 30 degrees flexion of the cubital joint and supination of the antebrachium and use a 35 x 43 cm film to facilitate upper extremity venous system interpretation. In the patient group, standard venography was compared with shunt-delineating venography (called shuntgraphy) as to advantages and drawbacks. Venography proved to be of excellent use in shunt constructive and reconstructive surgeries in that it provided information supplementary to that obtained in shuntgraphy, or even more valuable information.

Adult↗

Side effects and pharmacokinetics of nonionic iodinated contrast medium in hemodialyzed patients.

We conducted contrast CT scanning on 22 dialysis patients using the same method as usually applied to cases with normal renal function and studied the incidences and types of side effects and the pharmacological kinetics of non-ionic iodine contrast medium (Iopamiron 370, 100 ml). During the followup period (five days at most), we found localized urtication as a side effect in only one case (4.5%). Therefore we speculate that non-ionic contrast medium is a safe agent in dialysis patients, as long as it is cautiously used. After contrast medium injection, we conducted dialysis twice, which definitely decreased total blood iodine content. The extraction ratio at first dialysis was particularly high (73% on average). We recognized a statistically positive correlation between this extraction ratio and dialyzer size. Although two cases studied proved the notable acceleration of vicarious excretion in dialysis patients, this acceleration appeared only with high total blood iodine content. This phenomenon was considered mainly due to excretion from the hepatobiliary tract. Vicarious excretion appeared relatively soon after contrast medium injection (within a few hours), but showed a slower decreasing tendency.

Adult↗

[Cardiothoracic ratio and roentgenologic heart size as the indices of body fluid retention in uremics under hemodialysis].

We evaluated the cardiothoracic ratio (CTR) and the roentgenologic heart size (RHS) as the indices of body fluid retention in 31 of uremic patients under hemodialysis. The maximum changes of the roentgenologic thoracic diameter, measured monthly for one year in 31 patients, varied from 10 to 68 mm. The average differences of RHS and CTR between maximum inspiration and forced inspiration in 18 healthy people were 1 mm (RHS) and 2.5% (CTR), respectively, and the change of roentgenologic thoracic diameter was 12 mm. The error of repeated CTR measurements in a period of one year could be estimated more than 2%. In 22 patients the body weight reduction of 1 kg corresponded to a 4 mm decrease of RHS (p less than 0.005) and 1.5% of CTR (p less than 0.05), respectively. In relation to the change of body fluid balance assessed by the change of body weight, RHS showed a higher correlation than CTR. These results could be attributed that RHS was hardly influenced by the respiration, whereas CTR was surprisingly affected. It is concluded that the measurement of RHS is more useful as an index of control of body fluid balance than CTR.

Adult↗

Combined hepatitis B immune globulin and vaccine for postexposure prophylaxis of accidental hepatitis B virus infection in hemodialysis staff members: comparison with immune globulin without vaccine in historical controls.

Twenty-three staff members serving in a hemodialysis unit were exposed accidentally to needlestick contaminated with blood containing hepatitis B surface antigen and hepatitis B e antigen, as well as high levels of DNA polymerase activity (greater than 100 cpm). They received hepatitis B vaccine (20 micrograms) simultaneously with hepatitis B immune globulin (5 ml, 200 IU per ml) within 48 hr after the exposure, and the vaccination was repeated at 1 and 3 months. The protective efficacy was compared with that in a past study in the same unit in which 33 members were given hepatitis B immune globulin alone within 48 hr after the exposure to blood with similarly high levels of DNA polymerase activity. No differences were noted in age or sex between the staff members who were vaccinated and those who were not, nor were there any differences between their inocula in the titers of hepatitis B virus markers. During 12 months after the accident, only one (4%) of the 23 vaccinated members contracted hepatitis B virus infection, at a frequency significantly lower than 11 (33%) of the 33 members who did not receive vaccine (p less than 0.02). These results indicate that hepatitis B vaccine, when given in combination with hepatitis B immune globulin, is efficacious for postexposure immunoprophylaxis of accidental infection.

Adult↗

A balance between self-renewal and commitment in the murine erythroleukemia cells with the transferred c-myc gene; an in vitro stochastic model.

When murine erythroleukemia (MEL) cells, having the transferred rat c-myc gene under the control of human metallothionein II gene promoter, are induced to differentiate with dimethyl sulfoxide (DMSO), the level of differentiation is dependent on the c-myc levels which are modulated by the Zn++ ion. The clonal transformant cell line (38-2) can continuously grow in the presence of both DMSO and Zn++ ion. The proportion of differentiated cells in a population of the continuous culture is strongly affected by the concentration of Zn++ ions. These results suggested that a balance between self-renewal and commitment to differentiation of MEL cells is determined by the c-myc level, and that this cell line may be suitable for studying the stochastic process of growth and differentiation of hemopoietic stem cells.

Animals↗

Characterization of a new endothelial cell growth factor (f-ECGF) partially purified from the supernatant of human fibroblast cells.

A new endothelial cell growth factor (f-ECGF) was partially purified from the cultured medium of human fibroblast cells of embryonic lungs. The partially purified f-ECGF induced neovascularization in rabbit cornea. It showed a selective growth stimulatory activity on the endothelial cells in vitro, whereas acidic- and basic-fibroblast growth factors (a- and b-FGFs) showed a broad spectrum of growth stimulation among tissues or cells. f-ECGF did not compete with the binding of a-FGF to the cell surface receptor in HEP-G2 hepatoblastoma cell lines. These results indicated that f-ECGF is a new endothelial cell growth factor distinct from a- and b-FGFs which are known to be potent endothelial cell growth factors.

Animals↗

Measurement of portal blood flow by an ultrasonic "duplex" system composed of a pulsed Doppler flowmeter and a linear-type real time B mode electroscanner.

The portal vein hemodynamics of patients with various liver diseases were investigated by means of a duplex system consisting of a linear electroscanner and a pulsed Doppler flowmeter. In cases of chronic liver disease, the cross-sectional area of the portal vein trunk became greater as the liver injury proceeded, while the maximum velocity tended to decrease. However, blood flow volume was no different between the controls and the chronic liver disease group. On the other hand, the splenic venous flow volume tended to increase as the liver injury advanced, suggesting that the increase in splenic venous flow volume is closely related to the formation of esophageal varices. This method permits non-invasive observation of changes during the course of various types of liver disease.

Blood Flow Velocity↗

Antibody against the translation product of the pre-S2 region of hepatitis B virus and the resolution of infection after accidental needlestick exposure.

During a 5-yr period before the introduction of post-exposure immunoprophylaxis of hepatitis B virus (HBV), 363 medical personnel contracted infection after exposure to a contaminated needlestick. Among them, five (1.4%) developed a persistent carrier state, and they were followed for antibodies against translation product of the pre-S2 region (anti-pre-S2) by the enzyme immunoassay with native viral polypeptides. The consecutive seven cases in whom infection was terminated served as controls. In the acute phase, the levels of IgM and IgG anti-pre-S2 were significantly higher in the seven in whom infection resolved than in the five in whom infection persisted (mean sample:normal ratio, 11.1 +/- 4.4 vs 2.0 +/- 1.3 and 8.7 +/- 7.0 vs 3.0 +/- 1.1, respectively, p less than 0.05). In convalescence, 6 months after the normalization of serum transaminase, IgG anti-pre-S2 was detected in a high titer in the staff members with resolved infection (27.4 +/- 38.5), but was not detectable in those with persistent infection. On the basis of these observations, the intensity of humoral antibody response against the pre-S2 region product is closely correlated with the resolution of infection after exposure to HBV, and anti-pre-S2 persists in the circulation much longer than previously reported.

Accidents, Occupational↗