Search PubMed⌕ Search

Biomedical subjects

S Kojima

Publications and source records attributed to S Kojima.

At least 955 records · Page 53Linked to original sources
PubMed1983

Mutagenicity of bis- and mono-(2,3-dibromopropyl)phosphate, and their salts used as flame retardants, in the Salmonella/microsome system.

The mutagenicity of pure synthesized samples of bis(2,3-dibromopropyl)phosphate (bis-BP) and mono(2,3-dibromopropyl)phosphate (mono-BP) against Salmonella typhimurium TA100 was examined in relation to microsomal activation of tris(2,3-dibromopropyl)phosphate (tris-BP). Both mono- and bis-BPs were weak direct mutagens. Their mutagenicities increased with S9 mix, but the rates were much less than that of tris-BP. The magnesium and ammonium salts of mono- and bis-BPs were also prepared and their mutagenicities were examined with S9 mix in relation to 2 commercial flame retardants (our abbreviations: DB-1 and DB-2). In both mono- and bis-BP series, an apparent increase of mutagenicity was observed in the order: ammonium salt greater than magnesium salt greater than free acid. On the other hand, mono-BP and its salts are usually more active than the corresponding bis-BPs independently of the kind of cation. DB-1 (DB-2), however, is more potent than the magnesium (ammonium) salts of mono- and bis-BPs, the constituents in DB-1 (DB-2). No synergistic effect between mono-BP salts and bis-BP salts was observed. The different unknown mutagenic compounds in DB-1 and DB-2 are suggested.

Animals↗
PubMed1983

Immune response to Toxoplasma gondii. I. Toxoplasma-specific proliferation response of peripheral blood lymphocytes from patients with toxoplasmosis.

Peripheral blood leukocytes (PBL) from patients with toxoplasmosis were shown to be highly responsive to in vitro stimulation with Toxoplasma gondii extract as measured by incorporation of [3H]methylated thymidine. Analysis of Toxoplasma-specific proliferative cells in PBL by using monoclonal antibodies specific for human T cell subsets revealed that the Toxoplasma-specific proliferation response of PBL from the patients was mediated by Leu 1, Leu 3a positive cells, that is, helper/inducer T cells. Tests for the Toxoplasma-specific proliferation response may provide a readily available method for the diagnosis of congenital toxoplasmosis, especially during the newborn period.

Antibodies, Monoclonal↗
PubMed1983

Genetic control of immune responses to Schistosoma japonicum antigen.

A high-titre IgE-antibody response to Schistosoma japonicum antigen (Sj) is obtained if helper T cells are appropriately induced by the infection. The antibody responses were found to be regulated by a gene(s) linked to the major histocompatibility complex. Strains of H-2a and H-2k haplotypes were high responders, whereas H-2d, H-2b and H-2s strains were not. Results obtained by using intra-H-2 recombinant strains suggested that the immune-response (Ir) gene was mapped in the I-E subregion, although a possibility of the presence of complementary genes was not excluded. Interestingly, in low responders such as BALB/c mice, Sj-specific carrier effect could be demonstrated when mice were infected with S. japonicum before challenge immunization with dinitrophenylated Sj (DNP-Sj). Moreover, BALB/c as well as C3H/He was a high responder to Sj in proliferation of peritoneal exudate T-lymphocyte enriched cells in vitro, whereas B10.S was not. Based on these observations, possible roles of Ir genes in immune responses to Sj are discussed.

Animals↗
PubMed1983

Antigen-specific proliferation responses of peripheral blood lymphocytes to Trichomonas vaginalis antigen in patients with Trichomonas vaginitis.

This report describes the development of an assay system which overcomes the difficulty of detecting immune responses of patients with Trichomonas vaginitis by making use of peripheral blood leukocytes obtained from such patients. When peripheral blood leukocytes from the patient were stimulated in microcultures with the soluble antigen extracted from Trichomonas vaginalis, significant degrees of proliferation ensued, as measured by the incorporation of [methyl-3H]thymidine 4 to 5 days after initiation. The antigen-induced proliferation response of peripheral blood leukocytes is specific for T. vaginalis antigen. The T. vaginalis-specific [methyl-3H]thymidine incorporation is mediated by Leu-1-positive cells, namely, T lymphocytes, in the peripheral blood leukocyte population. This assay system should prove useful for the analysis of the immune response to the protozoa in patients with Trichomonas vaginitis.

Antigens↗
PubMed1983

Plasma norepinephrine concentration and plasma dopamine-beta-hydroxylase activity in patients with congestive heart failure.

The relationship between plasma norepinephrine (NE), epinephrine (E) and dopamine-beta-hydroxylase activity (DBH) was studied in 90 cardiac patients (New York Heart Association [NYHA] classes I-IV), 85 healthy control subjects and 18 competitive skiers. The cardiac patients in NYHA classes III and IV had significantly higher NE (p less than 0.001) and lower DBH (p less than 0.001) levels than the controls, whereas the skiers had significantly lower NE (p less than 0.001) and higher DBH (p less than 0.05) levels than the controls. Seven cardiac patients in whom successful cardiac surgery was performed had decreased NE (p less than 0.001) and increased DBH (p less than 0.02), as well as significantly improved NYHA cardiac status (p less than 0.001). These findings demonstrate an inverse relationship between NE and DBH in a population of athletes, normal subjects and cardiac patients; the same inverse relationship holds for these patients when sequential studies are done after a change in cardiac status.

Adolescent↗
PubMed1983

Determination of anaerobic threshold for assessment of functional state in patients with chronic heart failure.

The use of anaerobic threshold in assessment of aerobic capacity was evaluated in 34 normal subjects and 47 patients with various kinds of chronic heart disease. Anaerobic threshold was determined as the oxygen consumption (VO2) at which a linear relationship between pulmonary ventilation (VE) and VO2 was lost during progressive treadmill exercise. Anaerobic threshold determined in this manner was validated with that determined by blood lactate measurements in eight normal subjects and nine cardiac patients (r = .962, p less than .001). Thereafter, anaerobic threshold was determined only by respiratory measurements. In symptom-limited, maximal exercise, anaerobic threshold was reached well before maximal effort and corresponded to 70% of maximal VO2 both in normal subjects and cardiac patients. Anaerobic threshold decreased as age progressed in normal subjects (r = - .70, p less than .001). Anaerobic threshold in cardiac patients was lower than that in the normal subjects and decreased progressively as New York Heart Association functional classification advanced (normal, 32.95 +/- 6.17 ml/min/kg; class I, 22.78 +/- 3.74; class II, 16.99 +/- 3.66; class III, 12.97 +/- 2.76; p less than .01 between each group other than between class II and class III). Anaerobic threshold in cardiac patients correlated poorly with other objective indices, e.g., cardiomegaly (r = -.54, p less than .001) and rise in pulmonary wedge pressure (r = -.64, p less than .001). At anaerobic threshold, cardiac patients subjectively graded the work load as light (13%), light-to-moderate (27%), moderate (30%), and moderate-to-heavy (28%). Thus determination of anaerobic threshold by respiratory measurements is a safe, accurate, and objective method to measure aerobic capacity in cardiac patients and in normal subjects.

Adult↗
PubMed1983

Normalizing effects of plasma on altered cation transport of red blood cells from essential hypertensive patients.

Net Na+ and K+ fluxes were measured in Na+-loaded red cells from 19 normotensive control subjects, 22 essential hypertensive patients, and 8 secondary hypertensive patients. The ratio of Na+/K+ net fluxes was significantly lower in essential hypertensive patients than in normotensive control subjects. However, by the addition of the patients' own plasma, the net Na+ efflux rate was significantly increased in essential hypertensive patients, which caused the increment in the ratio of Na+/K+ net fluxes. This resulted in disappearance of the difference between normotensive and hypertensive subjects in the ratio of cation fluxes. It was possible that the abnormalities of cation transport in red cells from essential hypertensive patients might be compensated for by humoral factors in the plasma.

Adolescent↗
PubMed1983

Circadian rhythm of blood pressure in primary aldosteronism and renovascular hypertension--analysis by the cosinor method.

The circadian rhythm of blood pressure in 11 patients with primary aldosteronism (ALD) and 15 patients with unilateral renovascular hypertension (RVH) was analyzed using the cosinor method which fits a cosine function to a series of data. In ALD, both systolic (SP) and diastolic blood pressures (DP) increased in the late evening; the amplitude and acrophase of the circadian rhythm for SP were 7.3 (5.3 to 9.3, mean and 95% confidence limits) mmHg and 20:47 (19:42 to 21:52) hours, respectively, and for DP 2.6 (1.3 to 3.9) mmHg and 21:34 (19:40 to 23:28) hours, respectively. After excision of an adrenal adenoma in 6 patients, the circadian rhythm of SP and DP was abolished. In RVH, the acrophase of the circadian rhythm of SP and DP differed by about 12 hours; the amplitude and acrophase for SP were 5.7 (3.9 to 7.5) mmHg and 17:49 (16:35 to 19:02) hours, respectively, and for DP 1.5 (0.2 to 2.7) mmHg and 6:08 (2:44 to 9:31) hours, respectively. After various surgical interventions in 8 patients, the circadian rhythm of SP persisted with little change in acrophase, while that of DP disappeared. The difference in circadian rhythm suggests a difference in mechanisms of blood pressure control in ALD and RVH.

Adenoma↗
PubMed1983

Cation transport of red blood cells from hypertensive patients in Japan.

This study was performed to determine whether there is any difference in cation transport of red blood cells from normotensive subjects and hypertensive patients in Japan. Net Na+ efflux and net K+ influx rates were measured in sodium-loaded red cells from 19 normotensive subjects, 22 essential hypertensive patients, and 8 secondary hypertensive patients. The ratio of Na+/K+ net fluxes and the net cation flux rate were compared between these groups. The ratio of Na+/K+ net fluxes was significantly lower in essential hypertensive patients than in normotensive subjects. Parameters such as age, sex, blood pressure, plasma renin activity, and plasma aldosterone concentration were also examined in 2 groups of essential hypertensive patients, divided on the basis of their Na+/K+ net fluxes. However, there is no significant difference between the groups. These results suggest that the ratio of cation flux is related to hypertension independently of these parameters.

Adolescent↗
PubMed1983

Ultrastructural investigations on the effects of praziquantel on human trematodes from Asia: Clonorchis sinensis, Metagonimus yokogawai, Opisthorchis viverrini, Paragonimus westermani and Schistosoma japonicum.

The effect of praziquantel (Biltricide) on the ultrastructure of trematodes pathogenic to man in Asia was investigated in: Clonorchis sinensis, Opisthorchis viverrini, Schistosoma japonicum, Metagonimus yokogawai, and Paragonimus westermani. The different parasites were isolated from their respective experimental hosts and uniformly incubated for 5, 15, 30 or 60 min at 37 degrees C in medium TC 199 containing 0, 1, 10 or 100 micrograms praziquantel/ml. All parasites exposed to praziquantel were contracted and displayed tegumental alterations. 1. Clonorchis sinensis, Opisthorchis viverrini and Schistosoma japonicum reacted with severe tegumental vacuolisation within 5 min after exposure to 1 microgram praziquantel/ml. The extent of the damage induced increased with exposure time. 2. In vivo treated Opisthorchis viverrini worms had the same damages as in vitro treated ones. 3. Metagonimus yokogawai displayed the same degree of vacuolisation after exposure to all concentrations of praziquantel. Complete destruction of the tegumental surface was not achieved, however, possibly because of the presence of numerous tegumental hooks. 4. Paragonimus westermani was least sensitive to praziquantel. Only very few vacuoles were formed after incubation in 100 micrograms/ml for 60 min. It is assumed that the very dense texture of the thick tegument is responsible for the relative refractoriness to praziquantel in vitro. However, in vivo the parasite is successfully eliminated by praziquantel.

Animals↗
PubMed1983

Human gastric carcinoma: prognosis in relation to macroscopic and microscopic features of the primary tumor.

The correlation of prognosis with various clinical and pathologic factors was studied by use of multiple stepwise linear regression analysis among 77 patients undergoing resections for gastric cancer. Factors such as depth of penetration, invasion of the duodenum, macroscopic appearance, intramural and extramural growth pattern of the cancer, lymphatic or vascular invasion, and cancer cell-free dense submucosal fibrosis around the cancerous area were significant, and independent factors correlated with the prognosis, in that order. When these factors were taken into account, other factors such as sex and age of the patient, location, size, and histologic classification of the tumor, and folds' convergence were not significant.

Adenocarcinoma↗