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Biomedical subjects

K Kawashima

Publications and source records attributed to K Kawashima.

At least 19 recordsLinked to original sources

Culture of postimplantation rat embryos in rabbit serum for the identification of the growth factor in fractionated rat serum.

The growth factor for postimplantation rat embryos was investigated on the basis of the serum species-specificity in supporting embryonic development in culture. We used rabbit serum as a basal medium for the culture of head-fold stage rat embryos, and examined the effects of various fractions of rat serum on their development. In rabbit serum alone, rat embryos developed poorly. With the rat serum ultrafiltrate of molecular weight (MW) < 300,000, embryonic development improved, but not with the ultrafiltrate of MW < 100,000. With dialyzed rat serum or the globulin fraction of rat serum, embryonic development improved, but the albumin fraction had no effect. It was concluded from these results that some macromolecular growth factor for cultured postimplantation rat embryos was present in the globulin fraction of rat serum. The molecular weight of this growth factor was estimated to be between 65,000 and 300,000. Rabbit serum was considered to be suitable as a medium for the identification of this growth factor.

Animals

Acetylcholine synthesis is modulated by acetylcholine content of cytosolic fraction but not by that of releasable fraction.

Synthesis and release of acetylcholine (ACh) in the rat hippocampal slices were examined to clarify the mechanism of modulation of ACh synthesis. Treatment with 2-(4-phenylpiperidino)cyclohexanol (AH5183, 50 microM), an inhibitor of ACh transport from cytosol to synaptic vesicles, inhibited the increase in ACh content of the membrane-bound fraction which is readily releasable, but did not affect the cytosolic ACh content. Under these conditions, the total ACh content reached a plateau value. These results indicate that ACh synthesis is modulated by cytosolic ACh content but not by the vesicular fraction.

Acetylcholine

[Development of a gel phantom for dose distributions by MR imager].

We reported a method of determining spatial dose distributions in tissue-equivalent phantoms using nuclear magnetic resonance imaging. To make a gel phantom, a cross-linked dextran gel (Sephadex G-200) was used as fixation agent of a ferrous sulphate solution. Although high quality images are obtained, the cost is very expensive to make the gel. We developed a new gel which is combined with an extra water absorbent polymer (Sumikagel N-100) and Sephadex G-200. The gel permits the determination of dose distributions for three dimensional treatment planning.

Ferrous Compounds

Correlation of L-myc RFLP with metastasis, prognosis and multiple cancer in lung-cancer patients.

For further study of the correlation of L-myc restriction-fragment-length polymorphism (RFLP) and metastasis of lung cancer to lymph nodes or other organs at the time of surgery, L-myc RFLP was analyzed in 252 Japanese lung-cancer patients. A close correlation between L-myc RFLP and metastasis was confirmed in this large number of patients (p = 0.01). The correlation was particularly pronounced in cases of adenocarcinoma and squamous-cell carcinoma. Poor prognosis (additional metastases after surgery) was observed in lung-cancer patients with L-S (identified as long and short bands produced with EcoRI) and S-S type L-myc RFLP. In addition, the death rate of lung-cancer patients with the L-S and S-S types was greater than that of those with the L-L type. Lung-cancer patients of the L-S and S-S types had almost 4 times higher incidence of multiple cancer in the lung, pharynx and other organs than those with the L-L type. Our results indicate that, in patients with lung cancer, genetic disposition with respect to the L-myc gene influences the extent of metastasis, the incidence of multiple cancers and prognosis.

Combined Modality Therapy

Electrophoretic analysis of a natural population of the Thai Paragonimus heterotremus and its genetic relationship to the three Japanese species P. miyazaki, P. ohirai and P. westermani.

A total of 18 enzymes (encoded by 20 loci) from Paragonimus heterotremus collected at a local area in Saraburi, Thailand, were electrophoretically compared with those from the three Japanese species P. ohirai, P. miyazaki and P. westermani using horizontal starch-gel electrophoresis. Relative genetic distances between these species were quantified. The Thai P. heterotremus was found to be most closely related to P. miyazaki and rather distantly related to P. westermani. On the other hand, among the three Japanese species, the closest relationship was observed between P. miyazaki and P. ohirai.

Alleles

Immunopathology in Aujeszky's disease virus-infected pigs exposed to fluctuating temperatures.

Pigs exposed to fluctuating temperatures (high, 30 +/- 2 degrees C; low, 4 +/- 1 degrees C) were intranasally inoculated with Aujeszky's disease virus (ADV). ADV-infected pigs, exposed to the fluctuating temperatures, showed severe clinical signs and ADV in the nasal secretions persisted longer than in the ADV-infected control pigs kept at the normal temperature (20 +/- 2 degrees C). High concentrations of ADV were isolated from nasal secretions on the 1st day after inoculation of the virus. Pathologically, all ADV-infected pigs had non-suppurative encephalitis and trigeminal ganglionitis. The lesions were more widely distributed in pigs exposed to fluctuating temperatures than in infected control pigs. Two infected pigs given the stress had severe malacic foci in the frontal lobe and four of them had prominent interstitial pneumonia. In the pigs exposed to fluctuating temperatures, a significant number of immunoglobulin-containing cells, especially IgM-containing cells, did not respond to ADV infection. A significant (P < 0.01) difference in the number of IgG- and IgM-containing cells was observed between the ADV-infected pigs exposed to the fluctuating temperature and ADV-infected control pigs, respectively. These results demonstrated that the stress of fluctuating temperatures enhanced the susceptibility to ADV infection.

Animals

Neosporosis in the aborted fetus and newborn calf.

Protozoal encephalitic lesions were found in four aborted fetuses and one dead newborn calf. The organism was identified as Neospora caninum by immunoperoxidase. The brain lesions were of two forms. One was observed in three fetuses of 5 months gestation and was characterized by multifocal necrosis. The other was found in a 7-month fetus and in a newborn calf, and showed severe infiltration with macrophages and plasma cells containing IgG. This association, between the age of fetus and inflammation, may reflect development of the immune system in bovine fetuses.

Abortion, Veterinary

Combined Repeat Dose and Reproductive/Developmental Toxicity Screening Test (OECD): familiarization using cyclophosphamide.

A familiarization study was conducted on the "Combined Repeat Dose and Reproductive/Developmental Toxicity Screening Test (ReproTox)" proposed by the OECD. Cyclophosphamide (CP) at doses of 6.7, 4.5, 3, 2, and 0 mg/kg body wt was given daily by gavage to groups of 12 male and 12 female Sprague-Dawley rats. As a result, anemia and leukopenia were evident in treated males. The absolute and relative thymus and spleen weights were decreased in treated rats. Histopathologically, atrophy of the thymus, spleen, and bone marrow was observed. With respect to the reproductive/developmental toxicity, dose-dependent increases in postimplantation loss of fetuses and postnatal death were found in dams given CP. The body weight of pups treated with CP was significantly lowered in a dose-related manner. Thus the results demonstrated most of the known toxicological properties of CP, except the adverse effects on spermatogenesis and fertility. Therefore ReproTox can be considered as a useful screening test for assessing repeat dose and reproductive/developmental toxicity of existing chemicals of high production volume.

Animals

Determination of ion recombination loss by two-voltage method for pulsed radiation beams.

The ion recombination loss is one of the most important correction factors for dosimetry using ionization chamber especially for the measurement of high-intensity pulsed radiation beam. The two-voltage method has been used frequently for the correction of ion recombination loss. Several ways to approximate the method are presented. Comparisons were carried out to check the validity of the approximation. Using four ionization chambers of different types and shapes, measurements were made to obtain the optimal value of the ratio for the two voltages.

Humans

Inactivation of new carbapenem antibiotics by dehydropeptidase-I from porcine and human renal cortex.

The stability of the new carbapenem antibiotics, panipenem, meropenem and LJC 10,627, against porcine and human renal dehydropeptidase-I (DHP-I) was compared with that of imipenem. The order of stability to hydrolysis by renal DHP-I was: LJC 10,627 greater than meropenem greater than panipenem greater than imipenem. After incubation of the drugs with porcine or human enzyme at 30 degrees C for 4 h, the percentages of residual activity were as follows: LJC 10,627, 73.7% and 95.6%, respectively; meropenem, 0.2% and 28.7%, respectively; panipenem, 0% and 4.3%, respectively; and imipenem, 0% and 0.1%, respectively. These results demonstrate that LJC 10,627 has extremely high stability against renal DHP-I.

Animals

Triple cancers in the urogenital area of a patient with aplastic anemia.

Three epithelial neoplastic lesions, perineal Bowenoid papulosis, uterine cervical carcinoma, and bladder transitional cell carcinoma, which occurred in a mildly immunosuppressed patient who had aplastic anemia were studied for human papillomavirus (HPV) infection. In the Bowenoid papulosis, HPV type 16 DNA was identified by polymerase chain reaction (PCR) and by in situ hybridization (ISH). In contrast, in the uterine cervical carcinoma, HPV 16 was not detected, although possibly another unidentified type of HPV in the lesion was suggested by the ISH findings. In the bladder transitional cell carcinoma, neither papillomavirus genus-specific (PGS) antigen nor HPV DNA was found.

Adult

Renal dehydropeptidase-I stability of LJC 10,627, a new carbapenem antibiotic.

LJC 10,627 is a new parenteral carbapenem antibiotic. LJC 10,627 stability against human renal dehydropeptidase-I was compared with that of imipenem. Hydrolysis of this compound was not detectable by spectrophotometrical assay. Even after a 2-h incubation of antibiotics with this enzyme at 30 degrees C, the concentration of LJC 10,627 remained at 92.3% of the initial concentration, whereas imipenem completely disappeared. Thus, it was found that this compound was highly stable against human renal dehydropeptidase-I. Furthermore, LJC 10,627 had a low affinity for this enzyme, as indicated by the high Ki value (0.38 mM).

Animals

Syntheses of a glycerophospholipid, C16-platelet activating factor and a palmitoyl analogue of M-5, an anti-inflammatory glyceroglycolipid.

From a chiral C4-epoxide (-)-3, which is one of the synthons in our synthetic strategy for complex lipids, a glycerophospholipid C16-platelet activating factor (C16-PAF, 1) and a palmitoyl analogue (2) of an anti-inflammatory glyceroglycolipid M-5, which was previously isolated from the Okinawan marine sponge Phyllospongia foliascens, have been synthesized.

Anti-Inflammatory Agents, Non-Steroidal

Homeostasis as regulated by activated macrophage. VIII. LPSw (a lipopolysaccharide from wheat flour) can regulate bone resorption of chick embryo.

The effect of LPSw (a lipopolysaccharide from wheat flour) on the bone resorption of 18-d chick embryonic calvaria was examined in an organ culture following the method of Raisz. Bone was prelabeled in culture medium containing 45Ca and chased in a cold medium. On addition of test samples, labeled calcium was released indicating the grade of bone resorption. LPSw (10-100 ng/ml) stimulated bone resorption, showing an effect comparable to parathyroid hormone (PTH) (1 U/ml). PTH at 1 U/ml decreased the total amount of calcium and phosphorus, while LPSw did not. LPSw is thus assumed to stimulate bone resorption more actively than PTH.

Animals

[Studies on the teratogenic potential of p-tert-butylphenolformaldehyde resin in rats].

p-tert-Butylphenolformaldehyde resin, an adhesive, was given orally to pregnant Wistar rats by stomach intubation at the dose levels of 250, 500 and 1000 mg/kg body weight during days 7 to 17 of gestation, and the effects of the compound on dams and fetal developments were examined. No changes in general conditions, maternal body weight, food consumption, numbers of corpora lutea and implantation ratio were observed. There was no evidence of an increase in fetal death or of malformation attributable to the treatment with p-tert-butylphenolformaldehyde resin in any of dose levels examined. It was concluded that p-tert-butylphenolformaldehyde resin has no teratogenic effect in rats.

Administration, Oral

The measurement of muscle strength in the hip joint expressed by the octagonal diagram.

For grasping hip joint function objectively and planning an adequate program for individual use in rehabilitation during and after the treatment for hip joint impairments, the octagonal diagram of the correct distribution of the hip joint muscle strength will be useful. The muscle strength was measured in the eight directions using the Cybex-II on the U.B.X.T. table not only on the peak torque but also on the maximum work and the maximum work/sec in eighty healthy subjects, forty of each male and female. No difference of the muscle strength between the dominant and the non-dominant legs of both male and female has shown. In the percentage of the values of the muscle strength, there are differences between the peak torque, the maximum work value and the maximum work/sec. The data obtained from this investigation will be available to judge the degree of hip joint impairment, and to make a better therapeutic program for the patients.

Female