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Biomedical subjects

H Hamada

Publications and source records attributed to H Hamada.

At least 523 records · Page 29Linked to original sources
PubMed1983

Differential expression of lectin receptors in germ layers of the mouse egg cylinder and teratocarcinomas.

Receptors for three lectins with restricted specificities, namely fucose-binding protein of Lotus tetragonolobus (FBP), peanut agglutinin (PNA) and Dolichos biflorus agglutinin (DBA), were distinctively located in 6- and 7-day mouse embryos and in embryoid bodies of teratocarcinoma OTT6050 grown in vivo. Thus, FBP reacted mainly with the inner cells (embryonic ectoderm and teratocarcinoma stem cells), DBA reacted with the outer cells (endoderm) and PNA reacted with all the germ layers including mesoderm. Upon in vitro culture of the embryoid bodies, the exposed stem cells express DBA receptors. Since the receptors for the three lectins in teratocarcinomas are known to be carried by the large carbohydrate chains characteristic of early embryonic cells, the present result suggests that terminal structure of the large carbohydrates is altered according to the direction of the differentiation or to the position of the cells in embryos and in teratocarcinomas.

Amnion↗
PubMed1983

Juvenile granulosa cell tumor associated with rapid distant metastases.

We have encountered a case of juvenile granulosa cell tumor, first described by SCULLY as a specific form of granulosa cell tumor, in a 23-year-old, nulliparous female associated with some unusual clinicopathological features. The tumor showed a diffuse or macrofollicular pattern with eosinophilic or clear, often vacuolated cytoplasm containing abundant lipid. Ultrastructures revealed features very similar to those of previously reported juvenile granulosa cell tumor. Intracytoplasmic filaments were observed, but smooth surfaced endoplasmic reticulums were not evident. The patient succumbed unexpectedly rapidly due to recurrence and distant metastasis, in spite of anti-cancer therapy. It is also interesting that surprisingly high levels of estrogens as well as testosterone in both urine and serum was recorded before surgery and after the development of recurrence.

Adult↗
PubMed1983

Studies on the molecular weight of active and inactive renins in essential hypertension.

The molecular weight (MW) of active renin (AR) and inactive renin (IR) was investigated in individual plasma samples from 15 essential hypertensive and 5 normal subjects. The patients with essential hypertension were classified into 3 subgroups: low plasma renin activity (PRA), normal PRA and high PRA. The MW of AR and IR was estimated by Sephadex G-100 gel filtration. IR in the eluates was activated with trypsin. Plasma renin activity and renin activity in eluates were measured by radioimmunoassay of angiotensin I. At least 3 sizes of AR (MW: 48,000, 53,000 and 57,000) and 2 sizes of IR (MW: 53,000 and 57,000) were discovered, and the MW of AR was less than or equal to the MW of IR. The larger AR was predominant in the low PRA group and the smaller one in the high PRA group. This was also true for IR. This relation was also observed in the 2 types (high renin and low renin) of pooled plasma. In high renin pooled plasma the MW of AR and IR was about 48,000 and 54,000, respectively, while both were about 56,000 in low renin pooled plasma. It appears that the larger type of AR and IR remains in the circulation in the suppressed renin state, and that the smaller type of renins enters into the circulation when the secretion of renins is enhanced.

Enzyme Precursors↗
PubMed1983

Distribution of glycoconjugates in the kidney studied by use of labeled lectins.

Distribution of glycoconjugates in different areas of the rat kidney was studied by light and electron microscopy using six different horseradish peroxidase-labeled lectins. Glomeruli and brush borders of the proximal tubules reacted differently to these lectins, which indicated differences in the carbohydrate compositions of those regions. The ascending limb of Henle's loop (ALH) had strong binding sites for peanut agglutinin (PNA) and soybean agglutinin (SBA). Dolichos biflorus agglutinin (DBA) did not stain the cells of ALH but did stain those of distal convoluted tubules (DCT). DBA is a good marker for distinguishing ALH from DCT. DBA, PNA, and SBA were also good markers of the collecting duct. Ricinus communis agglutinin (RCA-1) and wheat germ agglutinin (WGA) diffusely stained the various components of different parts of the kidney.

Animals↗
PubMed1983

[Late-onset hallucino-delusional psychosis. Effect of sex and age on its symptoms and course].

Despite well-know semiological characteristics, the nosological position of the late onset hallucinatory-delusional psychosis with respect to schizophrenia is much debated. As regard prognosis factors, the study of 135 cases (36 men, 99 women) has shown that a sudden onset often happens in men, that, however, women often present a mental automatism syndrome, which becomes exceptional with age; finally, that influence phenomena are seldom found in men, especially after the age of 60. Rich and diversified symptoms of mental automatism are often observed in younger patients but they generally do not last. On the contrary, the clinical picture of the very late onset is comparatively simple and restricted; its main symptoms are either hallucinations or delusions and these symptoms tend to remain. Such semiological and evolutive modifications according to the age of the patient may appear in case of recurrence. The analysis of the pathoplastic role of age in the clinical picture leads to an hypothesis: a relation between the two possible evolutions (favourable and unfavourable) of the late onset hallucinatory-delusional psychosis and the two groups (atypical and nuclear) of schizophrenia.

Adult↗
PubMed1982

Potential Z-DNA forming sequences are highly dispersed in the human genome.

Recent analyses of the three-dimensional structure of synthetic DNA molecules has revealed the existence of a left-handed double-helical conformation of DNA, called Z-DNA. The Z-DNA structure was first observed in molecules having alternating guanine and cytosine bases, but has now also been shown for molecules of sequence poly(dT-dG) . poly(dC-dA) (refs 4-7). If Z-DNA occurs naturally then it might have quite different reactivities with molecules such as proteins or carcinogens from right-handed B-DNA. The interconversion of sequences between B and Z forms, under the influence, for example, of DNA binding proteins or chemical modification, may be important in regulating DNA function. So far, little data have been published on the occurrence of potential Z-DNA forming sequences in eukaryotic DNA. Here we report the presence of a sequence of 50 alternating dT and dG residues within one of the introns of a human cardiac muscle actin gene. Also, using a probe specific for poly(dT-dG) sequences, we have also found that potential Z-DNA forming sequences are highly repeated in the human genome.

Actins↗
PubMed1982

Uptake and localization of 99mTc-methylene diphosphonate in mouse osteosarcoma.

The localization of 99mTc-methylene diphosphonate (99mTc-MDP) in mouse osteosarcoma was studied using a skeletal scintigraphic method and macro- and microautoradiographic methods. On the skeletal scintigraph, the tumor showed a high uptake of 99mTc-MDP and its concentration was about 20 times as high as the value seen in the muscular tissue. The macroautoradiography showed high activity in the tumor bone region and little activity in the nonossified region. On the microautoradiography, the activity of 99mTc-MDP was localized in the mineralized matrix of tumor bone and was almost nil in the nonmineralized matrix (osteoid) and the tumor cells. These findings indicate that the mineralization of the tumor bone matrix plays an important role in 99mTc-MDP uptake in osteosarcoma.

Animals↗
PubMed1982

Molecular structure and evolutionary origin of human cardiac muscle actin gene.

Two recombinant phages that contain cardiac muscle actin gene were isolated from a human DNA library and their structures were determined. Restriction analysis indicates that both clones carry the same EcoRI 13-kilobase fragment where the coding sequence is mapped. The cloned DNA hybridized with polyadenylylated RNA from human fibroblasts, which directs the synthesis of cytoplasmic beta- and gamma-actin in vitro. However, sequence determination of the cloned DNA showed that the entire coding sequence perfectly matched the amino acid sequence of cardiac muscle actin. The initiation codon is followed by a cysteine codon that is not found at the amino-terminal site of any actin isoform, suggesting the necessity of post-translational processing for in vivo actin synthesis. There are five introns interrupting exons at codons 41/42, 150, 204, 267, and 327/328. Surprisingly, these intron locations are exactly the same as those of the rat skeletal muscle actin gene but different from those of nonmuscle beta-actin gene. Nucleotide sequences of all exon/intron boundaries agree with the G-T/A-G rule (G-T at the 5' and A-G at the 3' termini of each intron). The 3'-untranslated sequence has no homology to that of nonmuscle beta- or gamma-actin gene, but Southern blot hybridization has shown that this region has considerable homology to that of one of the other actin genes. These results indicate that the recombinant phages, which we have isolated, contain cardiac muscle actin gene and that cardiac muscle actin gene and skeletal muscle actin genes are derived from their ancestor gene at a relatively recent time in evolutionary development.

Actins↗
PubMed1982

A novel repeated element with Z-DNA-forming potential is widely found in evolutionarily diverse eukaryotic genomes.

By Southern blotting and hybridization analysis using 32P-labeled poly(dT-dG) . poly(dC-dA) as a probe, we have found, in eukaryotic genomes, a huge number of stretches of dT-dG alternating sequence, a sequence that has been shown to adopt the Z-DNA conformation under some conditions. This sequence was found in all eukaryotic genomes examined from yeast to human, indicating extraordinary evolutionary conservation. The number of the sequence ranged from about 100 in yeast to tens of thousands in higher eukaryotes. Comparison of nucleotide sequences of dT-dG alternating regions and its flanking regions in several cloned genes showed that the repeated element [the Z(T-G) element]] consists only of dT-dG alternating sequence with variable length. The presence of another purine-pyrimidine alternating sequence was also surveyed in eukaryotic genomes by Southern blot hybridization using 32P-labeled poly(dG-dC) . poly(dG-dC) as the probe. The stretches of dC-dG alternating sequence [the Z(C-G) element] were found to be moderately repetitive in human, mouse, and salmon genomes. However, a few and no copies of the Z(C-G) element were found in yeast and calf genomes, respectively. These results provide evidence for the abundance of potential Z-DNA-forming sequences in nature.

Animals↗
PubMed1982

[A giant chondromyxoid fibroma originated from the right orbital roof.--A case report--].

The authors reported a case of giant chondromyxoid fibroma of the right anterior cranial fossa, arising from the right orbital lamina of frontal bone. A fifteen-year-old boy was admitted because of a recent history of the right exophthalmus and headache. Neurological examination was essentially negative except papilledema in the both optic fundi and the right olfactory disturbance. Skull plain x-ray films showed the bony destruction of the right supraorbital bone and the some of abnormal calcification in the right anterior cranial fossa. CT scan showed cystic low density spots surrounded by irregular ring-like high density areas in the right anterior cranial fossa. Operation was performed on two stages and the tumor was removed totally. The tumor was arising from the orbital lamina of the frontal bone. The size of resected tumor was 7x5x4 cm. The pathological examination confirmed the diagnosis of chondromyxoid fibroma. Postoperatively, the patient is fully schooling without any disturbance 2 years and 7 months after the discharge. In Japan, two cases of intracranial chondromyxoid fibroma have been reported in literature. The authors discussed the histology of chondromyxoid fibroma and the genesis of the membraneous bone origin of the intracranial chondromatous tumor.

Adolescent↗
PubMed1982

[Mental disorders in Japanese living in Paris].

This paper relates the original work of a group of seven young Japanese psychiatrists during their residentship or their foreign assistant function in Paris. During approximately 3 years, they devoïd a part of their activity to assist their japanese copatriots who having developed some mental health accidents during they stay in the district of Paris. From the 28 patients, 15 have been hospitalized in different psychiatric wards of Paris but the french psychiatrists did not take part of the paper. The authors have divided their clinical material into 3 groups of japanese patients: tourists, permanent residents or temporary residents who represents 2/3 of the whole. In each group the incidence of nosographic diagnosis is precise and the transcultural problems are underlined. Finally, all the patients has been sent back to Japan.

Adaptation, Psychological↗