Biomedical subjects

M Tani

Publications and source records attributed to M Tani.

At least 253 records · Page 14Linked to original sources

PubMed1992

Enhancement of tumor cell susceptibility to lymphokine-activated killer cells by treatment with the streptococcal preparation OK432.

We investigated whether tumor cell lysis by LAK cells was augmented by treatment with OK432 in vitro. NK and LAK activity against K562 cells was not enhanced by their treatment with OK432. In contrast, the susceptibility of OK432-treated Daudi and KATO-III cells to lysis by LAK cells was enhanced. Succinate dehydrogenase activity and RNA synthesis were impaired in Daudi and KATO-III cells by treatment with OK432, and moreover the expression of HLA Class I antigen and beta 2-microglobulin was inhibited in OK432-treated KATO-III cells. Thus, it is suggested that the enhancement of the susceptibility of OK432-treated tumor cells with regard to succinate dehydrogenase activity, RNA synthesis, and HLA Class I antigen expression.

Antigens, Neoplasm↗

PubMed1992

Serum hepatocyte growth factor levels in hepatectomized and nonhepatectomized surgical patients.

Serum hepatocyte growth factor levels were measured in hepatectomized and nonhepatectomized surgical patients. The levels were significantly increased and reached a maximum within 7 days after surgery in both groups, returning to preoperative levels 28 days after partial hepatectomy and 7 days after other operations. Multiple regression analysis showed that such maximal hepatocyte growth factor levels were significantly related to having liver cirrhosis and postoperative maximal serum total bilirubin and alanine aminotransferase levels and peripheral white blood cell counts in the hepatectomized group and to postoperative maximal peripheral white blood cell counts and serum C-reactive protein levels in the nonhepatectomized group. However, the levels showed no relation to the resected liver volume and increment of the remaining liver volume 28 days after partial hepatectomy. It is concluded that serum hepatocyte growth factor levels were increased after partial hepatectomy in association with hepatocellular dysfunction and necrosis and systemic inflammation. It is unlikely that the increase was related to liver regeneration.

Alanine Transaminase↗

PubMed1992

Rate-dependent accessory pathway conduction due to phase 3 and phase 4 block. Antegrade and retrograde conduction properties.

Six patients who had antegrade phase 3 and phase 4 block in the accessory pathway were examined. In each patient, antegrade conduction over the accessory pathway was absent both at the sinus rate and at slower heart rates. During premature atrial stimulation a "window" of accessory pathway conduction was identified in all patients. The outer limits of the window ranged from 480 ms to 670 ms. The inner limits ranged from 410 ms to 620 ms. The durations of the window ranged from 20 ms to 160 ms. Three patients with orthodromic atrioventricular reentrant tachycardia showed preserved retrograde accessory pathway conduction. The remaining three patients had impaired retrograde accessory pathway conduction. One of the patients showed retrograde phase 4 block in the accessory pathway. In two patients, retrograde concealed conduction in the accessory pathway induced by ventricular stimulation prolonged the outer limit of the window in the antegrade accessory pathway conduction. These findings suggest that the mechanism of antegrade phase 3 and phase 4 block in the accessory pathway may be spontaneous diastolic depolarization in the accessory pathway and conduction disturbance at the ventricular and/or atrial insertion of the accessory pathway.

Adult↗

PubMed1992

Losartan, a specific angiotensin II receptor antagonist, increases angiotensin I and angiotensin II release from isolated rat hind legs: evidence for locally regulated renin-angiotensin system in vascular tissue.

The effect of Losartan (10(-9) to 10(-6) M) on angiotensins I and II release was examined in isolated hind legs perfused with Krebs-Ringer solution from normal and bilaterally nephrectomized rats. Losartan increased dramatically both angiotensins I (Ang I) and II (Ang II) release in a dose-dependent fashion; the maximal percent increment in Ang I and Ang II release evoked by Losartan (10(-6) M) was about +380% and +160%, respectively, in normal rat hind legs. In nephrectomized animals, Losartan elicited a marked increase in both peptides dose-dependently. There was a highly positive correlation between the released amounts of Ang I and that of Ang II altered by Losartan in either normal (r = 0.954) or nephrectomized rats (r = 0.923). These results not only confirm the existence of a functional renin-angiotensin system in vascular tissues, but also suggest that the system is regulated by locally generated Ang II.

Angiotensin I↗

PubMed1992

Effects of losartan, a nonpeptide angiotensin II receptor antagonist, on cardiac hypertrophy and the tissue angiotensin II content in spontaneously hypertensive rats.

Losartan, a recently developed nonpeptide angiotensin II (Ang II) receptor antagonist, was administered orally to 10-week-old spontaneously hypertensive rats (SHR) for 2 weeks. Cardiac weight and tissue Ang II, as well as plasma renin activity (PRA) and Ang II, were determined. Treatment with Losartan (10 mg/kg per day) lowered blood pressure markedly. Losartan reduced significantly the left ventricular weight by 11% compared with control rats. The left ventricular Ang II content was lowered by Losartan (18.6 +/- 0.9 pg/tissue; 21.9 +/- 0.9 pg/tissue, control, p less than 0.05), whereas PRA and plasma Ang II concentration were increased by the treatment. With the control and Losartan-treated animals, there was a significant positive correlation between the left ventricular weight and the tissue Ang II content (r = 0.563, p less than 0.05). These results provide evidence that cardiac tissue Ang II, rather than circulating Ang II, plays an important role in the pathophysiology of left ventricular hypertrophy of this animal model of human hypertension.

Analysis of Variance↗

PubMed1992

Hypotensive activity of TCV-116, a newly developed angiotensin II receptor antagonist, in spontaneously hypertensive rats.

TCV-116, a recently developed angiotensin II (Ang II) receptor antagonist, was administered orally (1 mg/kg per day) to 10-week-old spontaneously hypertensive rats (SHR) for 2 weeks. Blood pressure and plasma components of the renin-angiotensin-aldosterone system were determined in these rats. TCV-116 produced a marked reduction in blood pressure without altering heart rate. Whereas plasma renin concentration (PRC), angiotensin I (Ang I) and angiotensin II (Ang II) all were significantly increased, plasma aldosterone was decreased by approximately 70% compared with control animals. These results not only indicate therapeutic efficacy of this agent in the chronic treatment of human hypertension, but support also the concept that the renin-angiotensin system plays an important role in the control of blood pressure in this animal model of human essential hypertension.

Angiotensin Receptor Antagonists↗

PubMed1992

Immunoelectronmicroscopic differentiation of linear IgA bullous dermatosis of adults with coexistence of IgA and IgG deposition from bullous pemphigoid.

BACKGROUND: The differentiation between linear IgA bullous dermatosis (LABD) and bullous pemphigoid (BP) is sometimes difficult in patients who have both IgA and IgG deposition in a linear pattern at the basement membrane zone. OBJECTIVE: We address whether two cases of acquired subepidermal blistering disease with coexistence of IgA and IgG deposition in a linear pattern at the basement membrane zone are LABD or BP. METHODS: The two cases were investigated by immunoelectron microscopy and compared with two typical cases of LABD. RESULTS: In both cases, the deposition of IgA and IgG was ultrastructurally localized below the lamina densa in close association with anchoring fibrils, as was seen in two cases of typical LABD. CONCLUSION: These findings indicate that our two cases of acquired blistering disease with co-existence of IgA and IgG deposition are LABD, rather than BP.

Aged↗

PubMed1992

In vitro augmentation of the cytotoxic activity of peripheral blood mononuclear cells and tumor-infiltrating lymphocytes by famotidine in cancer patients.

We investigated the in vitro effects of famotidine on the cytotoxic activity of peripheral blood mononuclear cells (PBMC) and tumor-infiltrating lymphocytes (TILs). The cytotoxic activity of PBMC was augmented by famotidine at a concentration of 10 ng/ml, which is equivalent to the serum level achieved by the intravenous administration of a dose of 20 mg. This response to famotidine was seen only in cancer patients. Both the cytotoxic activity and DNA synthesis of activated TILs were increased by the combination of interleukin-2 and 1 microgram/ml of famotidine. Augmentation of cytotoxic activity by famotidine occurred independently of any decrease in the population of suppressor T-cells. Thus, famotidine may have the potential to be used in adoptive immunotherapy with TILs for cancer patients.

Antigens, CD↗

PubMed1992

Chemosensitivity testing of fresh human gastric cancer with highly purified tumour cells using the MTT assay.

A major problem associated with the chemosensitivity testing of fresh human tumour cells using the MTT assay is the contamination of nonmalignant cells in the tumour tissues. Highly purified fresh human gastric cancer cells could be obtained from 43 solid tumours and eight malignant ascites for the MTT assay. The success rate of the MTT assay was 87.9% (51 of the 58 cases), and the purity of tumour cells was greater than 90% after separation on Ficoll-Hypaque and Percoll discontinuous gradients in primary, or metastatic lesions, and also ascites. Cisplatin, mitomycin, and doxorubicin were more potent drugs than etoposide and 5-FU against gastric cancer cells. The chemosensitivity in differentiated cancer was equivalent to that in non-differentiated cancer. Twenty of the 51 patients with gastric cancer had evaluable lesions, and they received chemotherapy according to the results of the MTT assay using highly purified tumour cells. A clinical response was obtained in 12 of these 20 patients (response rate: 60.0%; five with complete response, seven with partial response).

Adult↗

PubMed1992

Electrophysiologic effects and efficacy of cibenzoline in patients with supraventricular tachycardia.

Electrophysiologic effects of intravenous (i.v.) cibenzoline were evaluated in 18 patients with accessory pathways or dual atrioventricular (AV) nodal pathways (12 men and 6 women with a mean age of 44 +/- 18 years). Twelve patients had accessory AV pathways, including 6 patients with a manifest accessory pathway. Six patients had AV nodal reentrant tachycardia (AVNRT). Electrophysiologic studies were performed before and after cibenzoline (1.4 mg/kg i.v.) infusion for 5 min. Sinus cycle length did not change significantly after cibenzoline administration. Cibenzoline increased both the AH (85 +/- 20 vs. 91 +/- 21 ms, p less than 0.05) and HV intervals (41 +/- 10 ms vs. 53 +/- 11 ms, p less than 0.001). Neither the atrial nor ventricular effective refractory period (ERP) was altered by cibenzoline. Complete block in the accessory pathway occurred antegradely in 4 patients and retrogradely in 1 patient. Cibenzoline prevented induction of AV reentrant tachycardia (AVRT) in 3 of 8 patients with sustained orthodromic AVRT by abolishing retrograde accessory pathway conduction or prolonging the retrograde accessory pathway ERP. Of 5 patients who continued to have inducible AVRT before and after cibenzoline administration, the tachycardia cycle length was increased in 3, mainly due to the increase in retrograde accessory pathway conduction time. Cibenzoline prevented induction of sustained AVNRT in 4 of 5 patients by prolonging the minimum pacing cycle length, maintaining 1:1 ventriculoatrial (VA) conduction through the retrograde fast AVN pathway or shortening the antegrade fast AVN pathway ERP equal to the slow AVN pathway. In one patient who had an uncommon type of AVNRT, sustained tachycardia was induced by cibenzoline.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

1 alpha,25-dihydroxyvitamin D3 modulates Ia antigen expression induced by interferon-gamma and prostaglandin E2 production in Pam 212 cells.

Recent investigations suggest that 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25(OH)2D3] has an effect on the regulation of immune responses and that keratinocyte (KC) expression of major histocompatibility complex class II antigens may be involved in immune responses. We investigated the modulation by 1 alpha,25(OH)2D3 of Ia antigen expression induced by interferon-gamma (IFN-gamma) and prostaglandin E2 (PGE2) production in Pam 212 cells. 1 alpha,25(OH)2D3 at 10(-6), 10(-8) or 10(-10) M significantly decreased the levels of IFN-gamma-induced Ia antigen expression in Pam 212 cells. Pam 212 cells produced PGE2 and 1 alpha,25-(OH)2D3 enhanced Pam 212 cell PGE2 production. However, indomethacin (1, 5 and 10 micrograms/ml) did not abrogate the inhibitory effect of 1 alpha,25(OH)2D3 on IFN-gamma induction of Ia antigen expression in Pam 212 cells, indicating that the products of the cyclo-oxygenase pathway do not mediate 1 alpha,25(OH)2D3 inhibition of IFN-gamma induction of Pam 212 cell Ia antigen expression. Our studies suggest that in Pam 212 cells the levels of Ia antigen expression induced by IFN-gamma and PGE2 production are negatively and positively regulated by 1 alpha,25(OH)2D3, respectively, and that 1 alpha,25(OH)2D3 may play a role in the regulation of immune responses.

Calcitriol↗

PubMed1992

Malignant Langerhans cell tumour.

We report the case of a 49-year-old woman suffering from a malignant neoplasm of Langerhans cells (LC), documented by immunohistochemical and ultrastructural analysis, and review the literature to examine and characterize the clinical and laboratory features, therapy, and prognosis of malignant neoplasms of LC. Langerhans cell histiocytosis is now regarded as a disorder of immune regulation or an inflammatory process, rather than as a malignant neoplasm. Although LC share certain features in common with ordinary histiocytes or interdigitating dendritic cells, they also differ significantly from these cells in other respects. Therefore, we propose designating a malignant neoplasm of LC 'malignant Langerhans cell tumour' and that it should be considered as a separate entity from Langerhans cell histiocytosis or other malignant histiocytoses.

Antigens, CD↗

PubMed1992

Systemic and cutaneous plasmacytosis with multiple skin lesions and polyclonal hypergammaglobulinaemia: significant serum interleukin-6 levels.

We report two patients who developed benign plasmacytosis with multiple skin lesions. The cases were characterized by hyperplasia of mature plasma cells, and polyclonal hypergammaglobulinaemia. One patient had hyperplasia of mature plasma cells not only in the skin, but also extensively in lymph nodes and the retroperitoneal areas around the ureters. The other had plasma cell hyperplasia limited to the skin. Extensive investigations failed to reveal any clinical or laboratory evidence suggesting the presence of any underlying disease accompanying the hypergammaglobulinaemia and/or plasma cell proliferation, such as chronic infectious disease, collagen disease or other chronic inflammatory disorder. Clinically and histologically, the first patient showed features compatible with a diagnosis of systemic plasmacytosis and the second with a diagnosis of cutaneous plasmacytosis. Significant serum interleukin-6 (IL-6) levels were detected in both patients, suggesting that IL-6 may be involved in the pathogenesis of these conditions.

Cell Division↗

PubMed1992

Effects of chronotropic responsive cardiac pacing on ventilatory response to exercise in patients with complete AV block.

To identify the effect of chronotropic responsive cardiac pacing on the ventilatory response to exercise, ten selected patients with complete atrioventricular block underwent paired cardiopulmonary exercise tests in fixed rate ventricular (VVI) and dual chamber (DDD) or rate responsive ventricular (VVIR) pacing modes. Compared to VVI pacing, DDD or VVIR pacing increased peak oxygen uptake (P < 0.005) and augmented anaerobic threshold (P < 0.001). In eight patients, dyspnea was the major symptom limiting exercise with VVI pacing and this was markedly attenuated with DDD or VVIR pacing. In all patients, ventilation (VE) and the ratio of ventilation to CO2 production (VE/VCO2) were consistently higher with VVI pacing during exercise. To compare the response of the two pacing modes at the same workloads in an aerobic condition, we measured ventilatory variables 1 minute prior to the anaerobic threshold obtained with VVI pacing. When DDD or VVIR pacing was compared with VVI pacing, VE and VE/VCO2 significantly decreased from 20.5 +/- 5.3 L/min to 18.3 +/- 5.0 L/min (P < 0.005) and from 35.9 +/- 5.8 to 31.9 +/- 5.0 (P < 0.001), respectively. Respiratory frequency rose significantly more with VVI pacing (P < 0.001) despite an unchanged tidal volume. Although peak VE did not differ between the two pacing modes, VE/VCO2 at the peak exercise increased significantly more with VVI pacing (P < 0.005). Respiratory frequency also rose more with VVI pacing (P < 0.005) and tidal volume did not change. This study suggests that chronotropic responsive cardiac pacing attenuates the exertional dyspnea by improving the ventilatory response to exercise as well as increasing the cardiac output in patients with complete atrioventricular block.

Anaerobic Threshold↗

PubMed1992

Two different reentrant circuits of ventricular tachycardia in a patient with an extensive anterior infarction: evaluation using electrical catheter ablation techniques.

Two morphologically distinct sustained ventricular tachycardias were initiated by programmed stimulation during attempted catheter ablation in a patient with an old anterior myocardial infarction. Right bundle branch block configuration of ventricular tachycardia, which was identical to the spontaneously occurring tachycardia, was initiated and displayed fragmented mid-diastolic potential at the apicolateral left ventricular site. Evidence of a critical slow conduction area was observed during delivery of electrical stimuli to this area. Following a 150-joule electrical shock delivered to this area, right bundle branch block pattern of ventricular tachycardia was no longer inducible but a new sustained monomorphic ventricular tachycardia with left bundle branch block pattern was initiated. The mid-diastolic fragmented activity at the ablation site became electrical activation of bystander area that was not participating in the left bundle branch block type of the ventricular tachycardia circuit. The critical slow conduction area was identified at the apicoseptal left ventricular site that was separated more than 5 cm from the ablation site. We speculate that two morphologically distinct sustained monomorphic ventricular tachycardias may be due to two different reentrant circuits and not the different expression of the same circuit.

Aged↗

PubMed1992

Quantitative relationship between atrial refractoriness and the dispersion of refractoriness in atrial vulnerability.

We investigated the quantitative relationship between the atrial refractory period and the dispersion of refractoriness with respect to atrial vulnerability in 19 adult mongrel dogs. The atrial effective refractory period (AERP) was measured at the sinus node area (SNA), the low posterior right atrium (LRA), and the distal coronary sinus. The study was performed under the following conditions: (1) control status; (2) hypothermia (30 degrees C); (3) vagus nerve stimulation; and (4) a combination of (2) and (3). The subjects were separated into two groups: atrial fibrillation (AF) (+) group (n = 23), which developed AF by atrial extrastimulus due to increased vulnerability, and AF (-) group (n = 39), which did not develop AF. The mean AERP was 97 +/- 21 msec (mean +/- SD) in the AF (+) group and 124 +/- 23 msec in the AF (-) group, with a significantly shorter refractory period seen in the former (P less than 0.001). The dispersion of refractoriness was 59 +/- 24 msec in the AF (+) group and 29 +/- 18 msec in the AF (-) group, with a significant increase noted in the former (P less than 0.001). On X-Y coordinates (where X denotes the AERP, and Y denotes the dispersion of refractoriness) the data from the AF (+) group were clustered in the upper left region of the graph while the data from the AF (-) group were clustered in the lower right region. These two groups were separated by a linear equation of Y = 0.86X - 57 with a predictability of 90.3%.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Hair follicle nevus.

We present a case of hair follicle nevus, a rare hamartoma composed of vellus hair follicles. Hair follicle nevus should be differentiated from accessory auricle, trichofolliculoma and hair nevus.

Child, Preschool↗

PubMed1992

Acute follicular graft-versus-host disease.

We documented by clinical, histopathologic and immunohistochemical analysis a case of acute follicular graft-versus-host disease (GVHD), in which an erythematous-to-violaceous follicular papular eruption constituted the major clinical pattern of cutaneous involvement. Although acute follicular GVHD is rare, it is important to recognize it as an early skin manifestation of acute cutaneous GVHD allowing prompt therapy.

Acute Disease↗