Biomedical subjects

S Murakami

Publications and source records attributed to S Murakami.

At least 343 records · Page 19Linked to original sources

PubMed1996

Radiographic investigation of mandibular periostitis ossificans in 55 cases.

The radiographic and clinical features of periostitis ossificans in 55 patients with mandibular osteomyelitis were studied. On the basis of whether the original mandibular contour was preserved or not, the lesions could be classified radiographically into two major types, each with two subtypes. Type I lesions were of shorter duration than Type II. Type 1-2 and Type II-1 periostitis ossificans were characteristically observed in patients under 25 years of age. Extraction of the lower third molar with pericoronitis was the most frequent cause of periostitis ossificans. An unerupted third molar tooth bud was found in close proximity to the area of periostitis ossificans in six patients. With adequate treatment there can be complete resolution of periostitis ossificans in Type I cases; however, when there has been loss of mandibular contour (Type II cases), mandibular deformity remains even when normal bony architecture has been restored.

Adolescent↗

PubMed1996

Thyroid involvement by malignant histiocytosis of Langerhans' cell type.

Involvement of the thyroid gland by Langerhans' cell histiocytosis is quite rare. We describe the case of a 58-year-old man referred for treatment of a progressively enlarging goitre. The trachea was severely stenotic and adjacent structures such as the left carotid vein and the thyroid cartilage were also involved. Central diabetes insipidus and severe combined immunodeficiency were associated. Although fine needle aspiration biopsy of the thyroid was initially interpreted as papillary carcinoma, anaplastic thyroid cancer was suspected. Treatment with prednisolone, doxorubicin and irradiation controlled the tracheal compression. A diagnosis of thyroid Langerhans' cell histiocytosis was finally made on the basis of the presence of Birbeck granules and CD1a and CD4 antigen in the thyroid tumour cells. Furthermore, positive staining for CD68 and lysozyme suggested that the tumour cells may have had the character of phagocytic cells in addition to their dendritic cell nature. This is the first case of thyroid involvement by malignant histiocytosis of Langerhans' cell type with unusual phagocytic markers.

Antigens, CD↗

PubMed1996

Elevated serum interleukin-6 and decreased thyroid hormone levels in postoperative patients and effects of IL-6 on thyroid cell function in vitro.

We studied a wide variety of surgical patients to determine whether serum levels of interleukin-6 (IL-6) or tumor necrosis factor-alpha (TNF-alpha) correlate with the changes in serum thyroid hormone levels of the postoperative period. Surgical procedures were divided into minor surgery (cholecystectomy, n = 12), moderate surgery (colorectal cancer and stomach cancer, n = 54), and extensive surgery (esophageal cancer or pancreatic cancer, n = 6). One day after surgery, serum free T3 levels decreased in all 3 groups when compared to the preoperative values; serum free T4 levels did not change regardless of surgical procedure. Serum TSH levels decreased significantly 1 day after surgery in the groups of moderate and extensive surgery. Serum levels of IL-6 increased 12 h after surgery and began to decrease gradually thereafter. There was no change in serum levels of TNF-alpha before and after surgery. The increment of serum IL-6 was dependent on the surgical procedures: the more extensive the surgery, the greater the increase in serum IL-6. Serum free T3 and free T4 levels were inversely correlated with the serum levels of IL-6. To further examine whether IL-6 is responsible for alteration of thyroid hormone production, cultured porcine thyroid follicles were exposed to 0 to 20 ng/ml of recombinant human IL-6 for 24 to 48 h. Then, type 1 5'-deiodinase activity (T4 to T3 converting enzyme), iodide uptake, and thyroid peroxidase (TPO) activity were measured. Our in vitro experiments showed no effect of IL-6 on these parameters. In summary, surgical procedure can cause elevation of serum IL-6 and decrease in serum free T3 levels. However, IL-6 alone does not appear to be a strong candidate for alteration of thyroid hormone production including T3 generation from T4.

Aged↗

PubMed1996

A genetic pathway conferring life extension and resistance to UV stress in Caenorhabditis elegans.

A variety of mechanisms have been proposed to explain the extension of adult life span (Age) seen in several mutants in Caenorhabditis elegans (age-1: an altered aging rate; daf-2 and daf-23: activation of a dauer-specific longevity program; spe-26: reduced fertility; clk-1: an altered biological clock). Using an assay for ultraviolet (UV) resistance in young adult hermaphrodites (survival after UV irradiation), we observed that all these Age mutants show increased resistance to UV. Moreover, mutations in daf-16 suppressed the UV resistance as well as the increased longevity of all the Age mutants. In contrast to the multiple mechanisms initially proposed, these results suggest that a single, daf-16-dependent pathway, specifies both extended life span and increased UV resistance. The mutations in daf-16 did not alter the reduced fertility of spe-26 and interestingly a daf-16 mutant is more fertile than wild type. We propose that life span and some aspects of stress resistance are jointly negatively regulated by a set of gerontogenes (genes whose alteration causes life extension) in C. elegans.

Animals↗

PubMed1996

Hypothesis: interventions that increase the response to stress offer the potential for effective life prolongation and increased health.

In the last decade it has become evident that many laboratory manipulations, both genetic and environmental, can lead to significant life extension. All or almost all of the observed life-extension phenotypes are associated with increased resistance and/or ability to respond to environmental stress. These observations show dramatically that life span is not maximized. We suggest that latent within many species-perhaps even humans-is the ability for large increases of life expectancy. The striking correlation between the increased stress resistance of all long-lived mutants in C. elegans and other species and the increased resistance of dietary restricted rodents to environmental toxins is consistent with an evolutionary conservation of a life-span maintenance/environmental stress resistance program. We suggest that it may be possible to develop methods for life extension in mammals, including humans, using relatively straightforward manipulations, such as drug treatments. It should be obvious that these findings have tremendous implications for human society at large, and we suggest that the implications of these findings should be explored.

Aging↗

PubMed1996

A new device for the treatment of coloproctostomic stricture after double stapling anastomoses.

OBJECTIVE: A new device of staple cutter was developed to evaluate the clinical effect for the treatment of rectal stricture after the double stapling anastomosis. SUMMARY BACKGROUND DATA: The double stapling technique has become an established reconstruction method for patients with low anterior resection. The major complication of anastomotic stricture associated with circular stapling has been reported to be harmful and distressing. Because underlying mechanisms of stricture are not well understood, no prophylactic means have been developed and this results in postoperative dilation still being the only treatment available. Although various dilation methods are used for the treatment of stricture, none is fully satisfactory. METHODS: Low anterior resection was performed in 30 patients with rectal carcinoma using a double stapling technique. First, the incidence of the anastomotic stricture and the clinical factors that contribute to the stricture formation were studied. Second, the clinical effects and advantages of the treatment of coloproctostomic stricture using the newly developed device (staple cutter) were evaluated. RESULTS: Nine (30%) of 30 patients had anastomotic stricture with the symptom of distressing frequent bowel movement. There was no significant relation between the clinical factors and the stricture when compared with that of nonstricture patients. Excellent dilation was performed in all of the nine strictures using the staple cutter, and the symptom of stricture disappeared dramatically in eight patients (89%) within 1 week. The recurrence of stricture occurred in two patients; however, it has not been observed after one further use of this treatment. The staple cutter is safe and easy to use even at the bedside, and except for a conventional anoscope, no special equipment, including fluoroscope, was needed. CONCLUSIONS: From the significant effects and advantages, the procedure using staple cutter is recommended highly for the treatment of circular stapling anastomotic stricture of the rectum.

Adult↗

PubMed1996

Optimal beam quality for chest computed radiography.

RATIONALE AND OBJECTIVES: Optimal x-ray beam quality for chest computed radiography (CR) has not been determined. To investigate the optimal beam quality for chest CR, the authors measured the radiographic contrasts and compared the image quality of chest CR and screen-film (SF) radiographs using various x-ray tube voltages. METHODS: Chest CR and SF radiographs were obtained on a phantom lung and human volunteers with or without a variety of simulated lung opacities using various x-ray tube voltage levels. Exposures were set to maintain identical patient exposure doses for all images. The contrast between peripheral lung and rib or heart was measured on these images and the differences were compared. The quality of the images of each simulated opacity was evaluated by five radiologists using a five-point grading scale. RESULTS: Contrast between peripheral lung and rib or heart increased on CR images obtained by lowering the tube voltage from 140 to 80 kV, but the degree of increase was less than half the increase on SF images. The CR images of the simulated opacities obtained using a lower tube voltage were judged to be superior to those obtained with a higher tube voltage. Scattered radiation was reduced on CR images with a lower tube voltage. CONCLUSION: The image quality of chest CR was improved by using a lower tube voltage than that used for conventional SF chest radiography. Considering the problem of tube loading in clinical applications, a tube voltage of 100 kV is recommended for chest CR.

Evaluation Studies as Topic↗

PubMed1996

Reduced liver function is the trigger for renal sodium retention following portal vein ligation in the rat.

Sodium retention along with peripheral vasodilation are features of prehepatic portal hypertension. In several models of experimental liver damage, sodium retention occurs only when hepatic function, measured by the aminopyrine breath test (ABT-k), falls below a critical threshold. The relationship between renal sodium handling, ABT-k and systemic and renal haemodynamics in partial portal vein ligated (PVL) rats was examined to test hypothesis that peripheral vasodilation was responsible for initiating sodium retention. Haemodynamic measurements were conducted early after surgery in portal hypertensive rats with and without sodium retention and in sham-operated controls. Compared with control, both PVL groups of rats had elevated portal pressure and lower peripheral vascular resistance (P < 0.05). Sodium retaining-PVL rats had both lower ABT-k (0.95 +/- 0.05 vs 1.38 +/- 0.06 x 10(-2)/min; P < 0.05) and higher sodium balance (1.38 +/- 0.09 vs 0.43 +/- 0.09 mmol/day; P < 0.05) than non-sodium retaining PVL rats. No differences in plasma renin activity or noradrenaline concentrations were observed. In a separate group of rats, hydralazine-induced pheripheral vasodilation did not induce sodium retention. These results suggest that the presence of peripheral vasodilation alone is not sufficient to trigger a sodium-retaining status. A factor, probably liver function-dependent, acting directly on renal tubules may be necessary for changes in renal sodium handling in this model.

Animals↗

PubMed1996

Serum interleukin-6 levels after urologic operations.

BACKGROUND: Endourology, extracorporeal shock wave lithotripsy (ESWL), and laparoscopic surgery are considered minimally invasive procedures; however, estimation of operative invasiveness has not been fully accomplished. We measured serum interleukin-6 (IL-6) levels, as an indicator for systemic reaction, to examine operative invasiveness of these operations in comparison with open surgery. METHOD: Serum IL-6 levels were measured in 119 patients undergoing open surgery, laparoscopic surgery, endourology, and ESWL. RESULTS: The median IL-6 levels on day 1 after the operation varied according to operative procedures: 83.5 pg/mL (range, 15-340 pg/mL) for open surgery, 24.8 pg/mL (range, 12-42 pg/mL) for laparoscopic surgery, and 10.8 pg/mL (range, 0-85 pg/mL) for endourology and ESWL. The extent of tissue injury and blood loss were found to be 2 major factors responsible for the serum IL-6 elevation. CONCLUSION: The minimally invasive character of endourology, ESWL, and laparoscopic surgery is attributable to low levels of tissue injury and blood loss, regardless of operative time.

Adolescent↗

PubMed1996

Characterization and regulation of interleukin-4 receptor in adult T-cell leukemia cells.

We studied the expression of the receptor of interleukin (IL-4), one of the T cell growth factors, on fresh peripheral blood leukemic cells from adult T-cell leukemia (ATL) patients. Flow cytofluorometric analysis with a monoclonal antibody to the IL-4 receptor (IL-4R) were used to investigate whether expression of IL-4R on ATL cells is different from that on normal lymphocytes and other types of leukemic cells. Leukemic cells from acute type ATL patients synthesize IL-4R without stimulation, at levels much higher than normal resting lymphocytes and other types of leukemic cells. Furthermore, leukemic cells from acute type ATL showed higher IL-4R expression than that of chronic type ATL or human T-cell leukemia virus type I carriers. In addition, there was correlation between expression of IL-4R on the cell surface and the proliferative response to IL-4. Both IL-4 and IL-2 induced upregulation of IL-4R on activated normal T cells but not on ATL cells. These results suggest that abnormal expression of IL-4R may display different biological activities in ATL compared with other types of leukemia. Furthermore, the high expression of IL-4R in ATL may be involved in the proliferation of leukemic cells and the leukemogenesis in this disease.

Adult↗

PubMed1996

Antigen-presenting-cell function of interferon gamma-treated human gingival fibroblasts.

The present study was carried out to examine the antigen-presenting cell (APC) functions of human gingival fibroblasts (HGF) elicited with IFN gamma. Stimulation of HGF with IFN gamma clearly induced HLA-DR expression and enhanced expression of intercellular adhesion molecule-1 (ICAM-1) on HGF. Despite the phenotypical resemblance of IFN gamma-treated HGF to so-called APC, HLA-DR positive HGF were unable to induce proliferation of allo-reactive peripheral blood T cells (PBT) isolated from different donors. The failure of IFN gamma-treated HGF to stimulate unprimed allo-reactive PBT was not due to the lack of production of IL-1 or the immunosuppressive effect of PGE2 from HGF. On the other hand, the fact that detectable expression of CD80, ligand for CD28, was not found on IFN gamma-treated HGF may at least in part explain the ineffective function of HGF as APC. Interestingly, IFN gamma-treated HGF induced proliferation of primed allo-reactive CD4+ T cells in a HLA-DR dependent manner, suggesting that IFN gamma-treated HGF may have the ability to stimulate pre-activated T cells. We then confirmed that high levels of IFN gamma mRNA were detectable in inflamed gingival tissue. Although it cannot be concluded from this study that HGF are incapable of effectively presenting antigenic peptides to autologous T cells bearing appropriate T cell receptors, present results suggest that HGF may be affected by locally-secreted IFN gamma and that the IFN gamma-stimulated HGF may play a role in regulating immune responsiveness in inflammatory periodontal lesions.

Antigen-Presenting Cells↗

PubMed1996

Diagnostic strategies of periodontitis based on the molecular mechanisms of periodontal tissue destruction.

OBJECTIVE: Periodontitis is a disease showing differences in disease progression between patients and between sites within a patient. Routine clinical examinations today are not useful enough to distinguish susceptible patients and active lesions from resistant patients and chronic lesions. Diagnostic markers should be pathogenic and inflammatory factors participating in periodontal tissue destruction. These are both local and systemic factors. MATERIALS AND METHODS: First of all, pathogenic factors and proinflammatory cytokines or mediators in gingival crevicular fluid (GCF) were examined and the difference was found between active and inactive periodontitis lesions distinguished by attachment loss. Active lesions were detected by discriminant-function analysis of these examinations, although the sensitivity of differential diagnosis was low. Then, we established a novel needle biopsy for understanding the pathophysiological conditions elicited in active and chronic inflammatory processes of periodontal tissue destruction. A variety of cytokines and mediators were detected in biopsied specimens by reversed transcription polymerase chain reactions (RT-PCR). Cytokine profiles were varied in inflammed periodontal biopsies. As IFN gamma mRNA expression was enhanced in inflamed gingiva, antigen-presenting-cell (APC) functions of human gingival fibroblasts (HGF) were examined. RESULTS: Despite the phenotypical resemblance of IFN gamma-treated HGF to so-called APC, HLA-DR positive HGF could not induce proliferation but suppressed proliferation of alloreactive peripheral blood T cells (PBT). However, HLA-DR positive HGF stimulated the proliferative responses of PBT which had been primed with allo-APC. Regulatory immune responses by IFN gamma were different in T cell conditions. CONCLUSIONS: Various kinds of cytokines participated in periodontal inflammation, and every cytokine is multi-functional. Complex and compound inflammatory processes can be clarified by examining cytokine networks and the precise effects of each cytokine on each of the cell types comprising periodontal tissue. It is, therefore, necessary for establishing diagnostic strategies to integrate pathogenic and inflammatory factors in periodontal tissue destruction.

Antibodies, Bacterial↗

PubMed1996

[Serological assay for diagnosis of verotoxin-producing Escherichia coli (VTEC) infection in the patients with diarrhea].

A total of 239 serum samples from 136 persons were used for bacterial agglutination assay (BA) against predominant three O-antigens of VTEC. All VTEC isolates from stools of 30 patients were only O157:H7 serotype (these patients are called group I). The levels of positive BA antibody titers (over 1:160) to O157-antigen were recognized in each patients as follows. The VTEC isolated patients with HUS or without HUS in group I were all of 13 (100%) and 14 (82.4%) in 17 patients, respectively. And 21 (65.6%) patients of group II (HUS patients with stool negative cultures, or stool cultures were not performed in 32 patients), and 6 (15.0%) patients of group III (family members of group I and II; 40 persons), were also recognized. In group IV (patients with diarrhea due to other pathogen than VTEC; 11 patients), and V (clinically healthy persons; 23 persons), none were recognized as positive BA antibody titers. All patients in the group II except one who had a positive BA antibody titer to O111, were not recognized to O111 and O26. A few VTEC-positive patients without gastrointestinal syndrome did not have significant agglutinating titers to O157-antigen on the days after VTEC isolation. However, almost all patients with diarrhea due to VTEC and HUS, and with VTEC but no HUS, had a level of positive BA antibody titer on the 5 day after onset of diarrhea. These results suggest that this serological assay is a very simple and useful tool for diagnosis of VTEC infection when VTEC are not detected by culture method due to antimicrobial treatment, or due to the lapse of many days after onset of diarrhea.

Antibodies, Bacterial↗

PubMed1996

Hypolipidemic effect of taurine in stroke-prone spontaneously hypertensive rats.

The hypolipidemic and antiatherosclerotic effects of taurine were investigated in genetically hypertensive rats: strokeprone spontaneously hypertensive rats (SHRSP). SHRSP were fed a hypercholesterolemic (HC) diet supplemented with 3% taurine for 50 days, and serum cholesterol was monitored. Cholesterol content and enzymatic activity responsible for cholesterol synthesis and metabolism were also determined in the liver, aorta, and intestine. Taurine prevented increases in the cholesterol level of the serum, liver, and aorta induced by a HC diet. Severe fat deposits of the mesenteric arteries induced by a HC diet were improved by the taurine treatment, showing the hypolipidemic and antiatherosclerotic effects of taurine. Taurine enhanced the activity of cholesterol 7 alpha-hydroxylase, a rate-limiting enzyme of bile acid synthesis, and stimulated bile acid production. These results suggest that taurine stimulates bile acid synthesis, which is closely related to the enhancement of cholesterol 7 alpha-hydroxylase activity, and thereby reduces serum cholesterol. In addition, a decrease in the intestinal acyl CoA:cholesterol acyltransferase activity by taurine suggests that the inhibition of cholesterol absorption may also be related to the hypolipidemic effect of taurine, in part.

Animals↗

PubMed1996

Role of herpes simplex virus infection in the pathogenesis of facial paralysis in mice.

To clarify the role and site of herpes simplex virus (HSV) infection in the pathogenesis of facial paralysis, we examined the viral genome by the polymerase chain reaction and the neutralization antibody titer using microplates in an animal model. Following inoculation with HSV type 1 of the KOS strain into mouse auricles, HSV DNA appeared in the ipsilateral facial nerve on the 3rd day, and in bilateral facial nerves and the brain stem on the 10th day only in animals with facial paralysis. In animals without facial paralysis, no HSV DNA was detected in these tissues. The neutralization antibody titer was elevated between 4 and 20 days in all animals, with or without facial paralysis. Facial paralysis developed only on the inoculated side, even though HSV DNA was also present in the contralateral facial nerve. We conclude that HSV infection in the facial nerve and brain stem is prerequisite for facial paralysis, and suggest that an immunologic reaction following viral infection plays a key role in the pathogenesis.

Animals↗

PubMed1996

CD44-hyaluronate interaction participates in the adherence of T-lymphocytes to gingival fibroblasts.

It has already been clarified that peripheral blood T-lymphocytes which had been activated with phorbol 12-myristate 13-acetate (PMA) acquired the ability to bind to human gingival fibroblasts (HGF) and that the adherence was mediated by VLA integrins. However, these studies also raised the possibility that molecules other than VLA integrins should be involved in the adherence between T-lymphocytes and HGF. In this study, the possible involvement of CD44, a hyaluronate receptor, in heterotypic cell-cell interactions was investigated. It was confirmed that PMA-activated T-lymphocytes strongly adhered to plate-coated hyaluronate and that the hyaluronate binding was clearly inhibited by the addition of OS/37, a newly established mAb specific for the hyaluronate-binding epitope on CD44. Interestingly, OS/37 also blocked the HGF binding of the activated T-lymphocytes when the adherence to HGF was assessed at 4 degrees C, at which temperature the adhesion of integrin molecules diminished, while that of CD44 functioned normally. Immunofluorescence staining revealed that hyaluronate was anchored along the cell surface of HGF. Furthermore, the binding of activated T-lymphocytes to HGF was significantly inhibited by the treatment of HGF with hyaluronidase. These results clearly demonstrated that CD44-hyaluronate interactions participated at least in part in the adhesiveness of T-lymphocytes to HGF.

Antibodies, Monoclonal↗

PubMed1996

Tongue volume in human female adults with mandibular prognathism.

It has often been hypothesized that a large tongue leads to an enlargement of the mandible and therefore contributes to the development of mandibular prognathism. We examined (1) whether the tongue volume in human subjects with mandibular prognathism was larger than that in subjects with good occlusion and (2) whether the tongue volume and the pharyngeal capacity correlated with the morphological characteristics of dento-skeletal structures. Magnetic resonance images of the tongue and its surrounding structures were recorded for female adult volunteers with good occlusion (control group, n = 10) and patients with mandibular prognathism (test group, n = 16). Lateral cephalograms were obtained for the patients. No significant differences were determined for the tongue volume or the pharyngeal capacity between the two groups. The tongue volume did not correlate with the pharyngeal capacity (r = 0.280, p = 0.166). The tongue volume correlated with the facial angle (r = 0.548, p = 0.028), the Y-axis (r = 0.539, p = 0.031), and the angle nasion-A point-pogonion (r = 0.540, p = 0.031). These results suggest that the tongue volume is accounted for by the combined horizontal and vertical location of the chin and symphysis, but do not support the conventional clinical surmise that large tongue volume is inherent in patients with mandibular prognathism.

Adult↗

PubMed1996

Presence of atypical laminin on the surface of mouse Lewis lung carcinoma cells.

We investigated the expression and distribution of laminin in Lewis lung carcinoma LL2-Lu3 cells. The microscopic immunofluorescence study of the non-permeabilized cells and blotting assay after immunoprecipitation with anti-laminin antibodies of biotinylated cell surface proteins demonstrated that LL2-Lu3 cells retained laminin on their cell surfaces. This laminin was atypical in that it lacked A chain as revealed by the immunoblot analysis. The results of the reverse transcription polymerase chain reaction method indicated that LL2-Lu3 cells contained mRNA for B1 and B2 chains, but not A chain corresponding to those of typical laminin derived from murine Engelbreth-Holm-Swarm sarcoma. A precursor form of 67 kDa laminin receptor protein was also shown to exist on the surfaces of LL2-Lu3 cells. These findings suggest that the interaction between atypical laminin and the precursor form of the 67 kDa laminin receptor protein on the cell surfaces may function in regulating cell activities such as metastasis of LL2-Lu3 cells.

Animals↗