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Biomedical subjects

K Kameda

Publications and source records attributed to K Kameda.

At least 91 records · Page 5Linked to original sources

Structure and regulation of the avian gene for fatty acid synthase.

Starvation, glucagon and cyclic AMP inhibit, and refeeding starved animals and insulin or IGF-I plus triiodothyronine stimulate accumulation of FAS and its mRNA in liver; transcription is the primary regulated step. In the uropygial gland, differentiation of basal cells into mature sebocytes is accompanied by the accumulation of large amounts of FAS and its mRNA. By analogy with liver, transcription is likely to be the regulated step, but direct experimental evidence for this hypothesis is lacking. FAS mRNA is a unique gene and is probably more than 100 kb in length. The FAS gene of goose and duck is transcribed into two mature mRNAs of about 10,800 and 12,200 nucleotides. The 3'-untranslated regions of the FAS mRNAs contain an unusual polypyrimidine tract which, at the mRNA level at least, appears unrelated to regulation of gene expression. Polypyrimidine tracts similar in sequence to that in the FAS gene are found in about 20 different parts of the genome. All of the fragments which contain these tracts are hypermethylated. The next stage of this investigation will involve identification of cis-acting sequence elements in the FAS gene which specify responses to diet, hormones and tissue-specific regulatory factors. Isolation and characterization of the 5'-ends of the cDNA and the gene are underway.

Animals↗

[A case of epilepsy with myoclonoic absences].

A case of epilepsy with myoclonic absences is reported. A boy, 3 years and 8 months old, had the first attack at the age of 1 year and 8 months. He was mentally retarded, but had no evidence of organic brain damages. He had been said to have "absence" at another hospital for 2 years until he was referred to our hospital. The attack was characterized clinically by sudden loss of consciousness accompanied with rhythmical massive myoclonias. The ictal EEGs showed synchronous diffuse 3 c/s spike-wave discharges. There was a strict and constant relation between spike-wave discharges and the myoclonia. The polygraphy recording (EEG and EMG of various muscles) was very helpful for the diagnosis of epilepsy with myoclonic absences. We think that epilepsy with myoclonic absences should be considered in any case of "absence" with concomitant 3 c/s spike-wave discharges which is resistant to appropriate treatment, or is accompanied with mental retardation.

Child, Preschool↗

[Severe respiratory failure with pulmonary tuberculosis during initial phase of chemotherapy].

In seven patients with tuberculosis required ventilatory assistance, in our IRCU at the Habikino Hospital, we found worsening of the findings on chest X-ray film and clinical status during initial phase of chemotherapy, although their sputum became negative for acid-fast bacilli. On admission, six of them had large infiltration with cavities and discharged a large number of bacilli with elevation of ESR and hypoalbuminemia. We could get four patents off ventilator after start of PEEP therapy and high dose corticosteroid therapy. But three of them died at last, because they developed severe respiratory failure again. Pulmonary histology was available in five patients. We found interstitial and intra-alveolar pulmonary edema, intra-alveolar organization, hyperplasia of alveolar wall, and hyaline membrane formation. These findings were compatible with diffuse alveolar damage.

Adult↗

Analyses of epididymal sperm surface antigens by monoclonal antibodies against hamster spermatozoa.

BALB/c mice were immunized with spermatozoa from cauda epididymides of hamsters and the immune spleen cells were fused with mouse myeloma cells (P3U1). Seven hybridomas (GHS-1,-2,-3,-4,-5,-6, and -7) that produced monoclonal antibodies (Mabs) binding to the epididymal spermatozoa were established. Three Mabs (GHS-3,-4, and -6) were IgM and the other four were IgG1. All Mabs reacted to hamster spermatozoa from cauda epididymides but none of the Mabs except GHS-5 and -7 reacted to spermatozoa in testis. GHS-5 and -7 Mabs bound to the acrosome region of spermatozoa in both testis and epididymis. The antigens corresponding to GHS-2, -4, and -6 Mabs appeared to be excreted from epithelial cells of caput epididymis, while those to GHS-1 and -3 Mabs seemed to be produced in cauda epididymis. Both groups of the antigens bound to the surface of spermatozoa during their epididymal transit. Immunoblotting analyses of epididymal fluid showed that the antigen epitopes corresponding to GHS-1,-2,-3,-4, and -6 Mabs were distributed to multiple components with different molecular weights ranging from over 100 to 25 kd. The distribution patterns of the epitopes corresponding to GHS-1 and -3 Mabs and GHS-2,-4, and -6 Mabs were very similar, respectively, but each group pattern was quite different from each other. GHS-5 Mab reacted to a component of sperm extract with a molecular weight of around 94 kd, while GHS-7 Mab failed to recognize any components transblotted.

Acrosome↗

Electron microscopic study of the biopsied cardiac muscle in Duchenne muscular dystrophy.

Cardiac muscular biopsies were performed on 4 patients with Duchenne muscular dystrophy (DMD). None of the patients had cardiac symptoms and all of them exhibited normal electro- and echocardiographic findings. Electron microscopic examination of cardiac muscles from 4 patients with DMD disclosed proliferation of the mitochondria, changes in the cristae, abnormalities of the Z-bands, dilatation of the sarcoplasmic reticulum, deposition of glycogen, and changes in the nuclei. The most striking finding in these patients was that the residual bodies were increased and were observed mainly in the perinuclear region. These ultrastructural features suggest that an extreme exhaustion had already been present in myocardial tissue of the patients prior to the onset of cardiac symptoms.

Adolescent↗

Serum lipid levels in elementary and junior high school children and their relationship to relative weight.

Serum lipid levels were measured in 2,626 schoolchildren ages 7 to 15 years in three elementary schools and one junior high school in a suburban area of Osaka during 1984-1985. The mean cholesterol levels increased with age in boys ages 7 to 10 years (from 156 to 177 mg/dl) and then decreased at age 13, after which the levels again increased slightly until age 15. Girls showed a similar tendency with a peak at age 10 and a minimum at age 12. Cholesterol levels were significantly lower in junior high school boys (a mean of 154-161 mg/dl for ages 13-15 years) than in girls of the same age or in boys and girls ages 10 to 12 years in the upper grades of elementary school. Cholesterol and triglyceride levels tended to be lower or the high-density lipoprotein cholesterol levels higher in elementary schools where boys and girls engaged in physical exercise than in schools where the children were not strongly encouraged to exercise. About 50% of the hypertriglyceridemic children were obese.

Adolescent↗

Detection of T-factor in lung cancer using magnetic resonance imaging and computed tomography.

The ability of magnetic resonance imaging (MRI) to detect T-factor was compared with that of computed tomography (CT) in 52 patients with primary lung cancer proven by surgery or autopsy, and the results were analyzed in relation to the operative and pathologic findings. In the diagnosis of tumor invasion of the heart and great vessels, MRI provided information as accurate as CT. The T1-weighted images in particular were of considerable value in separating the tumor from the mediastinal and hilar fat. Tumor extent in accompanying peripheral obstructive pneumonia or collapse was demarcated in 21% of the cases studied by CT and in 33% to 53% by MRI. On the other hand, the T2-weighted images obtained with longer echo time (TE) were useful in distinguishing the tumor from secondary changes.

Adenocarcinoma↗

Establishment and characterization of a human hybridoma secreting monoclonal antibody with high titers of sperm immobilizing and agglutinating activities against human seminal plasma.

Peripheral blood lymphocytes isolated from an infertile woman possessing strong sperm immobilizing and agglutinating antibodies were stimulated by culturing with poke-weed mitogen (PWM) and spermatozoa from a healthy donor for 5 days. The stimulated lymphocytes were fused with mouse myeloma NS-1 by PEG-1000. Fused growing hybrid cells were observed in 58 of 96 wells, and 22 of these showed the production of human immunoglobulin. Among the 22, one hybridoma clone (H6-3C4) was found to produce human IgM (lambda) with strong sperm immobilizing and agglutinating activities. The supernatant from the culture medium contained approximately 1.5 microgram IgM/ml and the antibody titers were 5000 SI50 units on sperm immobilization and 1:1600 dilutions on sperm agglutination. The hybridoma H6-3C4 has continuously produced high titers of antibody exhibiting sperm immobilizing and agglutinating activities over 8 months and contains chromosomes of acrocentric type from mouse and metacentric type from human. The monoclonal antibody (Mab) H6-3C4 reacted specifically to human seminal plasma, ejaculated spermatozoa and male accessory gland but not to testis, any other somatic tissues, or secreted fluids tested. Immunofluorescence staining indicated that the antigen corresponding to Mab H6-3C4 was present over the surface of ejaculated spermatozoa. The binding of Mab H6-3C4 to human spermatozoa was blocked by the serum of the patient from whom the lymphocytes were obtained for cell fusion.

Adult↗

Transport of fatty acid is obligatory coupled with H+ entry in spheroplasts of Escherichia coli K12.

Transport of palmitate by spheroplasts of Escherichia coli K12 was studied. [14C]Palmitate was accumulated in spheroplasts approximately 1700-fold over the extracellular concentration of unbound [14C]palmitate. Uptake of [14C]palmitate was inhibited to 13% by addition of H+ uncoupler carbonyl cyanide-m-chlorophenylhydrazone (CCCP). Spheroplasts exhibited the uptake of 9-aminoacridine depending on the addition of palmitate to the incubation mixture. The rate of [14C]palmitate uptake by the spheroplasts pre-equilibrated in a buffer at pH 7.5 or 8.0 significantly increased in comparison with the spheroplasts pre-equilibrated in a buffer at pH 7.0 when the spheroplasts were incubated at an external pH of 7.0.

Biological Transport, Active↗