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H Hayashida

Publications and source records attributed to H Hayashida.

82 records · Page 5Linked to original sources
PubMed1979

The preferential codon usages in variable and constant regions of immunoglobulin genes are quite distinct from each other.

The pattern of codon utilization in the variable and constant regions of immunoglobulin genes are compared. It is shown that, in these regions, codon utilizations are quite distinct from one another: For most degenerate codons, there is a selective bias that prefers C and/or G ending codons to U and/or A ending codons in the constant region compared with the bias in the variable region. This would strongly suggest that, in immunoglobulin genes, the bias in code word usage is determined by other factors than those concerning with the translational mechanism such as tRNA availability and codon-anticodon interaction. A possibility is also suggested that this differance of code word usage between them is due to the existence of secondary structure in the constant region but not in the variable region.

Anticodon↗
PubMedDate not supplied

Sequence homology between retroviral reverse transcriptase and putative polymerases of hepatitis B virus and cauliflower mosaic virus.

In infected cells, the RNA genomes of RNA tumour viruses are copied into DNA by a virus-encoded reverse transcriptase enzyme. This transfer of information from RNA into DNA was thought to be a unique feature of RNA tumour viruses, but recent results suggest it may be a more general strategy. Hepatitis B virus (HBV) has a double-stranded DNA genome, and it has recently been shown that the minus DNA strand of the HBV genome is copied from a plus-strand RNA template, leading to the suggestion that reverse transcription is central to the life cycle of HBV. More recently it has been suggested that the replication cycle of a plant virus, cauliflower mosaic virus (CaMV), includes a reverse transcription step. We report here the existence of amino acid sequence homology between retroviral reverse transcriptase and the putative polymerases of HBV and CaMV.

Amino Acid Sequence↗
PubMedDate not supplied

Isolation and structural organization of the human preproenkephalin B gene.

The primary structure of porcine preproenkephalin B has been elucidated by cloning and sequencing cDNA: it contains neoendorphin, dynorphin and leumorphin (containing rimorphin as its amino-terminus). These opioid peptides, each having a leucine-enkephalin structure, act on the kappa-receptor. We have now cloned a human genomic DNA segment containing the preproenkephalin B gene. The structural organization of this gene resembles those of the genes encoding the other opioid peptide precursors, that is, preproenkephalin A and the corticotropin-beta-lipotropin precursor (ACTH-beta-LPH precursor). The primary structure of human preproenkephalin B has been deduced from the gene sequence. The amino acid sequence homology observed between preproenkephalin B and preproenkephalin A, together with the similarity between their gene organizations, suggests that the two genes have been generated from a common ancestor by gene duplication.

Amino Acid Sequence↗
PubMedDate not supplied

Ultrastructural study of primary lacrimal adenocarcinoma.

PURPOSE: Primary adenocarcinoma of the lacrimal gland is a rare malignant tumor of the orbit. Up to now, there has been no presentation of its ultrastructural features. The histopathological findings and fine structures of one case of adenocarcinoma of the lacrimal gland are described in the present work. METHODS: The patient was a 59-year-old Japanese man with proptosis that had persisted for one month. A tumor was extirpated, and the tissues were prepared for light and electron microscopic examination. RESULTS: Electron microscopic examination demonstrated that the tumor cells had well-developed microvilli and lumens. These ultrastructure features are similar to those seen in adenocarcinomas at other sites. CONCLUSIONS: These observations suggest that the accurate diagnosis of rare malignant adenocarcinoma depends not only on routine techniques such as light microscopy of hematoxylin-eosin and PAS-diastase stained slides, but also on electron microscopic findings.

Adenocarcinoma↗
PubMedDate not supplied

Subretinal neovascularization associated with retinochoroidal coloboma.

PURPOSE: To report a case of subretinal neovascularization associated with retinochoroidal coloboma. METHODS AND RESULTS: A 44-year-old female presented with metamorphopsia in her right eye for 4 weeks. Funduscopic examination revealed bilateral inferior retinochoroidal coloboma. Fluorescein angiography disclosed foci of subretinal neovascularization at the margin between the colobomatous defect and the normal-appearing retina. Five month later, multiple small areas of subretinal hemorrhages were noted. The hemorrhage was gradually absorbed. Six years after initial presentation, subretinal hemorrhage did not recur and her right VA was 0.2. CONCLUSIONS: Ophthalmologists should be aware of this rare but important complication of retinochoroidal coloboma.

Adult↗