Biomedical subjects

T Kawakami

Publications and source records attributed to T Kawakami.

At least 343 records · Page 19Linked to original sources

PubMed1991

Comparison of protein tyrosine phosphorylation and morphological changes induced by IL-2 and IL-3.

We constructed cell lines which can proliferate in response to IL-2 or IL-3 by introducing a wild-type and mutant forms of cDNAs encoding the human IL-2R p75 chain into an IL-3 dependent hematopoietic cell line which expresses the p55 chain of the IL-2R. We compared early events that were induced in these cells by IL-2 and IL-3. Analysis of protein tyrosine phosphorylation showed that two common protein bands, pp95 and pp90, were phosphorylated by stimulation of either IL-2 or IL-3, suggesting the possible sharing of part of a signal transduction pathway between IL-2R and IL-3R. Comparison of protein tyrosine phosphorylation profiles induced by IL-2 and IL-3 among a variety of cell lines revealed that the pp90 band is the common tyrosine phosphorylation substrate in the cell lines examined, although the general tyrosine phosphorylation pattern differed in each cell line. Mutant p75 molecules incapable of inducing tyrosine phosphorylation could bind and internalize IL-2, but could not support cell growth. We also found that swift changes of cytoskeletal protein organization are one of the early events caused by signal transduction through either IL-2R and IL-3R. Reorganization of cytoskeletal proteins seems to be associated with protein phosphorylation, as a significant portion of pp90 was found in a detergent-soluble fraction in IL-2 or IL-3 treated cells.

Base Sequence↗

PubMed1991

Effects of the penetration of a root canal filling material into the mandibular canal. 1. Tissue reaction to the material.

The root canal filling paste Vitapex (Neo Dental Chemical Products Co., Tokyo), made of calcium hydroxide and iodoform with the addition of silicone oil, was experimentally introduced into the mandibular canals of 29 dogs. Tissue reactions to the paste were examined by radiography, histopathology, and electron microscopy. These examinations revealed that the paste was phagocytosed by macrophages and, in general, was gradually resorbed over time. The paste was also found to cause heterotopic calcification and/or ossification within the area of original penetration.

Animals↗

PubMed1991

Effects of the penetration of a root canal filling material into the mandibular canal. 2. Changes in the alveolar nerve tissue.

The root canal filling material "Vitapex" (Neo Dental Chemical Products Co., Tokyo), made of calcium hydroxide and iodoform with the addition of silicone oil, was experimentally injected into the mandibular canals of dogs, and its effect on the alveolar nerve tissue was examined by light and electron microscopy. No change was observed as long as the injected paste did not come into direct contact with the nerve, but tissue damage was found at sites of direct contact. After removal of degenerated nerve debris by macrophages and Schwann cells, the persisting external membranes or "Schwann tubes" appeared to provide a scaffolding for axonal regeneration and Schwann cell proliferation.

Animals↗

PubMed1991

[Exposure of workers to electric and magnetic fields from radiofrequency dielectric heaters to process polyvinyl chloride material].

Exposure of workers to electric and magnetic fields from radiofrequency dielectric heaters (RF heaters) to process polyvinyl chloride material was surveyed. Measurements of electric and magnetic field strengths were made in 10 workers operating 7 RF heaters at 3 plants in Japan. Six of the RF heaters are of the sewing machine type and the other is of the shuttle tray type. In all the RF heaters surveyed the nominal frequency of the radiofrequency generator was 40 MHz, and therefore electric and magnetic field from these are assumed to oscillate at the same frequency. The power output ranged from 0.83 W to 1.8 W for the sewing machine type and was 2.4 W for this shuttle tray type. Measurements were made at about 5 cm from the surface of the hand, eye, chest, waist, knee and foot of each worker. The meter readings were converted to equivalent plane wave power density and corrected for duty cycle (0.073 to 0.27). It was found that all the workers surveyed were exposed to electric and magnetic field strengths greater than the TLV recommended by ACGIH (1 mW/cm2). For the hand, eye, chest, waist, knee and foot of the worker, 95%, 63%, 32%, 47% and 36% and 27% of the measured field strengths exceeded the TLV, respectively. Especially for the sewing machine type RF heaters, electric fields at the hand and eye were extremely strong. Thus, for the hand, 100%, 75% and 38% of the measured electric field strengths exceeded the TLV, ten times the TLV, and one hundred times the TLV, respectively, and for the eye, 88% and 25% exceeded the TLV and ten times the TLV, respectively. No correlation was observed between power output of the RF heaters and measured electric and magnetic field strengths at any anatomical site of the worker.

Chemical Industry↗

PubMed1991

[Discrepancy between the serum levels of gamma seminoprotein and prostate-specific antigen in patients with prostatic neoplasms. Both true or either untrue].

Serum levels of prostatic acid phosphatase (PAP), gamma-seminoprotein (gamma-Sm) and prostate-specific antigen (PSA) were determined simultaneously in 57 patients with benign prostatic hyperplasia (BPH) and in 50 untreated patients with prostatic cancer (adenocarcinoma, N = 47 and non-adenocarcinoma, N = 3). The correlations between the serum levels of gamma-Sm and PSA in these patients were assessed by linear regression analysis. Some fundamental studies were added for explaining the causes of discrepancy between the serum levels of gamma-Sm and PSA. All of BPH group underwent transurethral resection of the prostate (TURP) and the sera were obtained for measurements before, immediately after and 18 hours after TURP. The gamma-Sm correlated well with the PSA in the sera obtained before (r = 0.76) and 18 hours after (r = 0.73) TURP. However, there was no correlation (r = 0.26) between them in the sera obtained immediately after TURP. In 47 untreated patients with adenocarcinoma of the prostate, no significant correlation (r = 0.19) between serum levels of gamma-Sm and PSA was observed, although there was correlation (r = 0.51) between those of PAP and PSA. When these patients were classified into two groups, M0 (stage A-C; N = 26) and M1 (stage D; N = 21), however, the serum gamma-Sm correlated with the serum PSA in M0 group (r = 0.57), but didn't in M1 group (r = 0.11). Furthermore, the differences in the means of PAP (p less than 0.05) and PSA (p less than 0.001) between M0 group and M1 group were statistically significant, although the serum gamma-Sm failed to distinguish M0 from M1. The anti-PSA antibody of "PSA Kit" reacted against the standard gamma-Sm adopted from "gamma-Sm Kit". Surprisingly, the anti-gamma-Sm antibody of "gamma-Sm Kit" also reacted against the standard PSA adopted from "PSA Kit". The gamma-Sm and PSA apparently cross-reacted each other. The quantitative analyses with serial dilution of the sera were done by using each assay in 3 patients whose serum levels of gamma-Sm were markedly different from those of PSA. The dilution curve for PAP appeared to be rectilineal, and that for PSA also appeared to be approximately rectilineal. However, the gamma-Sm assay failed to be proportional. In conclusion, the correlation between serum levels of gamma-Sm and PSA was absent in certain circumstances, when the true values of them were expected to be much higher than those determined.(ABSTRACT TRUNCATED AT 400 WORDS)

Acid Phosphatase↗

PubMed1991

A new antibiotic, okicenone. I. Taxonomy, fermentation, isolation and biological characteristics.

A new antibiotic, okicenone was isolated from the culture broth of Streptomyces sp. KO-3599. The antibiotic possesses cytocidal activity against mammalian tumor cells in vitro at concentrations of 0.53-11.0 micrograms/ml whereas the antibiotic showed no antimicrobial activities against Gram-positive and Gram-negative bacteria, fungi or yeast at a concentration of 1,000 micrograms/ml.

Animals↗

PubMed1991

[Cerebral blood flow velocities in the anterior cerebral arteries and basilar artery. III. Investigation in hydrocephalus (Part 2)].

We made 10 measurements of Pourcelot's index of resistance (RI) in the anterior cerebral artery (RI-ACA) and basilar artery (RI-BA), and RI ratio (= RI-ACA/RI-BA) in seven cases of hydrocephalus before and after treatment. The mean values of RI-ACA (0.831 +/- 0.050, mean +/- SD), RI-BA (0.800 +/- 0.053) and RI ratio (1.039 +/- 0.030) before treatment were significantly higher than in normal infants. Two hours after treatment, the mean RI-ACA (0.654 +/- 0.099) was lower than in normal infants, and RI-BA (0.684 +/- 0.101) were normalized. Before treatment, the mean value of RI-ACA was higher than that of RI-BA. All RI ratios were higher than 1.00. After treatment, the mean RI-ACA was lower than the mean RI-BA. All RI ratios were normalized and lower than 1.00 (0.957 +/- 0.024).

Basilar Artery↗

PubMed1991

[Introduction and evaluation of the international training program for primary health care in Thailand].

Since 1987 the international training course on primary health care (PHC) in Thailand has been offered six times by the ASEAN Institute for Health Development, Mahidol University, Thailand. The main objective of the training was to enhance the understanding of Japanese and Thai students and junior health and social scientists regarding health problems in Thailand, their social, economic and political backgrounds and PHC activities. The course content consisted of lectures regarding the health care delivery system and the PHC activities including on-site visits, field visit to urban and rural areas and small group discussions on the health problems in these areas, home stay at the rural village, and discussion on health and social development in Thailand. The training course was evaluated by the participants both at the end of the course and after one year. Almost all of the participants reported that they were provided with valuable experiences by the course. After one year, all of the participants that responded to the evaluation questionnaire stated that their attitude to social problems had been influenced by the training.

Education, Medical↗

PubMed1991

[Cerebral blood flow velocities in the anterior cerebral arteries and basilar artery. II. Investigation in very low birth weight infants].

We studied the values of the Pourcelot's index of resistance in the anterior cerebral artery (RI-ACA) and basilar artery (RI-BA) in very low birth weight infants weighing less than 1,500 g at birth. At the time of measurements, their postconceptional ages were 32, 34, 36, 38, 40 and 42 weeks. The mean value of RI-ACA (0.744 +/- 0.026, +/- SD) was significantly lower than that of RI-BA (0.766 +/- 0.026) (p less than 0.001), and they were higher than those in normal term infants. However, the mean value of RI-ACA and RI-BA, averaged from the measurements of postconceptional ages at 38, 40 and 42 weeks, showed no significant difference from those of normal term infants. In contrast, the mean value of RI ratio (= RI-ACA/RI-BA) in very low birth weight infants showed no significant difference from that of normal term infants.

Analysis of Variance↗

PubMed1991

[Surgical treatment of renal cell carcinoma with tumor thrombus in inferior vena cava].

Removal of renal cell carcinoma (RCC) extended into the inferior vena cava (IVC) can be a difficult operation. Between 1941 and 1989, 110 RCC patients were treated with radical operation and examined for tumor thrombus histopathologically. Twenty nine (26.3%) patients had invasion into the returning vein of tumor (Stage Vla), 12 (10.9%) in renal vein (stage Vlb) and the remaining 4 (3.6%) into IVC (stage V2). In one patient who had surgery under extracorporeal circulation, a thrombus was extended into the right atrium. In the remaining three patients, the RCC was confined to a small portion of the IVC and operated by caval sleeve resection. Radical operation in such patients free of any distant metastasis, may raise the survival rate.

Aged↗

PubMed1991

[Cerebral blood flow velocities in the anterior cerebral arteries and basilar artery. I. Investigation in term infants].

We studied the value of Pourcelot's index of resistance in the anterior cerebral arteries (RI-ACA) and basilar artery (RI-BA) in 69 measurements of term infants on days 1, 5, 10, 15, 20, 30 and 60. The mean value of RI-ACA (0.723 +/- 0.038, +/- SD) was significantly lower than that of RI-BA (0.750 +/- 0.041) (p less than 0.001). RI-ACA values were higher than RI-BAs in only five measurements (7.2%). The values of RI-ACA and RI-BA decreased from the first day to the fifth day of life. They increased continuously and showed their highest values on the day 15. After the 15th day, they decreased mildly again. The values of RI ratio (= RI-ACA/RI-BA) were stable (0.96-0.97).

Basilar Artery↗

PubMed1990

Axoplasmic transport of mitochondria in cultured dorsal root ganglion cells.

The movements of individual mitochondria in cultured mouse dorsal root ganglion cells were directly observed by using fluorescent staining with rhodamine 123 in combination with video microscopic techniques. This gives greater spatial and temporal resolution and much higher specificity than possible by conventional methods. The instantaneous velocities were 0.55 +/- 0.11 microns/s anterograde and 0.60 +/- 0.10 microns/s retrograde. Movement of the mitochondria was in fits and starts, and some reversed direction. The number of mitochondria moving retrogradely was 1.5-1.9 times greater than the number moving anterogradely. The average length of mitochondria moving retrogradely was 2.8 microns and of mitochondria moving anterogradely was 4.1 microns. These results suggest that mitochondria increase their numbers by division in the nerve fiber terminal.

Animals↗

PubMed1990

Circadian variations in trichloroethylene toxicity under a 12:12 hr light-dark cycle and their alterations under constant darkness in rats.

In order to investigate the circadian variations in acute toxicity of trichloroethylene (TRI), TRI (1.2 g/kg weight) or saline was injected intraperitoneally in a total of 88 male Wistar rats at four circadian stages (03.00, 09.00, 15.00, and 21.00:hr.min) under two different lighting regimens of a 12:12 hr light-dark cycle (LD; light from 06.00 to 18.00) and of constant darkness (DD). Circadian variations in TRI toxicity were confirmed in both LD and DD. The toxicity of TRI evaluated by the increase in glutamic-pyruvate transaminase activity (GPT) was greatest when injected at 09.00 in LD while at 21.00 in DD. The increases in blood urea nitrogen, serum total cholesterol and triglyceride concentrations reached peaks when injected at 09.00 in LD and 03.00 in DD. The circadian variations in serum trichloroethanol concentration were very similar to those in GPT in both LD and DD, showing a significant correlation (p less than 0.05). The present study revealed that circadian variations in TRI toxicity existed in LD and that these variations persisted in a free-running condition. The peak phase of TRI toxicity was located in a trough phase (09.00) in LD and in a peak phase (21.00 or 03.00) in DD of temperature rhythm. Thus, the phase relationship changed in DD, showing a desynchronization between TRI toxicity rhythm and temperature rhythm, which is an unusual phenomenon. This means that an unexpected potentiation of TRI toxicity during active phase which is not a critical phase in a well-synchronized state could occur in a free-running condition.

Animals↗

PubMed1990

Coordinate expression of src family protooncogenes in T cell activation and its modulation by cyclosporine.

Activation of T lymphocytes induces transcription of several important genes which encode lymphokines and lymphokine receptors as well as "proliferation complementary" protooncogenes like c-myc or c-fos. Recently, the expression of lck gene, one of the src family gene, has also been shown to be modulated during T cell activation. We, therefore, assessed the question of whether other src family genes are expressed during the activation of T cells and of whether cyclosporine, a potent immunosuppressive drug, affects expression of these genes. We examined the expression of four different src family genes (lck, c-src, fyn, and c-fgr) in addition to the expression of IL-2, c-fos, c-myc, and actin genes in murine T cells which were activated with PMA plus ionomycin or PMA plus anti-CD3 mAb. We found that T cell activation was associated with the up-regulation of these src family genes and that the expression of these genes was specifically blocked in the presence of cyclosporine indicating that these activation-related genes were coordinately regulated.

Blotting, Northern↗

PubMed1990

A case of Dandy-Walker malformation associated with occipital meningocele, microphthalmia, and cleft palate.

We present a case of Dandy-Walker malformation associated with occipital meningocele, microphthalmia, and cleft palate. Small numbers of cases of Dandy-Walker malformation with occipital meningocele have been described in the literature, but to our knowledge, non of these also had microphthalmia or cleft palate. This association suggests that time of intrauterine origin of Dandy-Walker syndrome was in the sixth or seventh embryonic week. In the diagnosis, both CT cisternography and direct neurosonography over the occipital meningocele was useful for the demonstration of a posterior fossa cyst which communicated with the fourth ventricle and the occipital meningocele.

Abnormalities, Multiple↗

PubMed1990

A rare variant of acinic cell carcinoma of the upper lip: a case report and review of the literature.

Acinic cell carcinomas of the lip are most uncommon. An exhaustive search of the Japanese- and English-language literature has revealed only 17 previously reported cases. One additional occurrence, a rare variant of this type of neoplasm, with mucous differentiation, that occurred in the upper lip of a 60-year-old man is described here. A brief review of the literature on this type of lip tumor is also given.

Carcinoma↗

PubMed1990

Cerebral blood flow velocities in the anterior cerebral arteries and basilar artery in hydrocephalus before and after treatment.

We studied Pourcelot's index (PI), which shows cerebral vascular resistance, in the anterior cerebral arteries and basilar artery, and the PI ratio (Pourcelot's index in the anterior cerebral artery/Pourcelot's index in the basilar artery) in 11 measurements of hydrocephalus. The mean values of PI in the anterior cerebral artery, basilar artery, and the PI ratio before treatment were significantly higher than those after treatment and those in normal infants. Before treatment, the mean PI in the anterior cerebral arteries was significantly higher than the mean PI in the basilar artery. All PI ratios increased to 1.00 or more. After treatment and in normal infants, the mean PI in the anterior cerebral arteries was significantly lower than the mean PI in the basilar artery. All PI ratios decreased to less than 1.00. We believe that the PI ratio is useful to evaluate the need or effect of treatment in hydrocephalus.

Basilar Artery↗

PubMed1990

The cytoplasmic domain of the CD8 alpha-chain is required for its interaction with p56lck.

The CD8 glycoprotein expressed on the surface of CTLs is a heterodimer composed of alpha (Lyt-2) and beta (Lyt-3) chains. Recent studies have shown that CD4 and CD8 are physically associated with a T cell-specific protein-tyrosine kinase p56lck. Our previous experiments have suggested strongly that p56lck interacts directly with CD4 and CD8 molecules. The present report using cytoplasmic deletion mutants of the CD8 alpha-chain gene has extended our observations to demonstrate unequivocally that the cytoplasmic domain of the CD8 alpha chain is responsible for interaction with p56lck. The data has also confirmed the importance of the conserved twelve amino acid sequence motif of the CD8 alpha cytoplasmic domain in complex formation with p56lck.

Amino Acid Sequence↗