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Biomedical subjects

G Sasaki

Publications and source records attributed to G Sasaki.

33 records · Page 2Linked to original sources
PubMed1995

Cytokine profile of tumor cells in mycosis fungoides: successful treatment with intra-lesional interferon-gamma combined with chemotherapy.

Two cases of mycosis fungoides (MF) in the tumor stage were treated with intra-lesional interferon-gamma (IFN-gamma) therapy. After systemic chemotherapy, intra-lesional recombinant interferon-gamma was applied to the residual tumors. Intra-lesional IFN-gamma was sufficiently effective in the treatment of MF tumors, especially small-sized ones. Reverse transcriptase polymerase chain reaction (RT-PCR) analysis of messenger RNA expression of cytokines commonly detected interleukin-6 (IL-6) and IFN-gamma in the tumor cells before intra-lesional IFN-gamma. However, in our study, tumor cells in these cases did not exhibit the definitive cytokine patterns of Th1 or Th2.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Cytoplasmic accumulation of a normally mitochondrial malonyl-CoA decarboxylase by the use of an alternate transcription start site.

Malonyl-CoA decarboxylase, a normally mitochondrial enzyme, accumulates in the cytoplasm of specialized glands to cause production of multiple methyl-branched fatty acids. Evidence was presented that a single copy of the decarboxylase gene present in the goose genome codes for both the mitochondrial form found in extremely low amounts in the liver and the cytosolic form found in large amounts in uropygial glands. To elucidate how a single gene encodes both forms, the malonyl-CoA decarboxylase gene and the cDNAs for both the mitochondrial (liver) and the cytoplasmic (gland) species were cloned and sequenced. The decarboxylase gene, found in a 21-kb segment of cloned genomic DNA, is composed of five exons of 0.521, 0.118, 0.156, 0.145, and 1.93 kb interrupted by 6.9, 1.5, 0.45, and 9.3-kb introns. Exon 1 revealed two ATGs in frame 150 bp apart. cDNA for the cytoplasmic form and mitochondrial form showed identical nucleotide sequence, except that the latter was longer than the former. The longest cDNA for the cytoplasmic form of the enzyme extended only 44 bp 5' to the second ATG and the position corresponded to the transcription initiation site of the cytoplasmic form revealed by primer extension and RNase protection. The cDNA for the mitochondrial form isolated from the library extended 19 bp further upstream. Primer extension and RNase protection indicated that transcripts for the mitochondrial form initiated upstream from the first ATG. The N-terminal segment of the open reading frame initiated at the first ATG showed an amphipathic signal sequence appropriate for mitochondrial import. A putative full length mRNA for the mitochondrial form of the enzyme when translated in vitro yielded a 55-kDa primary translation product which was processed by removal of about 5 kDa during uptake into goose liver mitochondria. These results strongly suggest that in most tissues transcription initiates 5'- to the first ATG, generating a transcript that would generate a protein with an N-terminal leader for transport into mitochondria. In the uropygial gland the use of an alternate promoter generates transcripts initiated between the two ATGs and the translation product accumulates in the cytoplasm since it lacks a mitochondrial targeting sequence.

Alternative Splicing↗
PubMed1991

Estradiol induces proliferation of peroxisome-like microbodies and the production of 3-hydroxy fatty acid diesters, the female pheromones, in the uropygial glands of male and female mallards.

During the mating season the female mallards produce sex pheromones, diesters of 3-hydroxy fatty acids, in their uropygial glands. Subcellular fractionation by sucrose and Nycodenz density gradient centrifugations and electron microscopic examination of the fractions showed that diesters of 3-hydroxy acids and the enzymes that catalyze the formation and esterification of the 3-hydroxy fatty acids are located in the catalase-containing fractions, probably peroxisomes, whereas monoester synthesizing activities are located in the endoplasmic reticulum. Fatty acyl-CoA reductase that would provide fatty alcohol needed for the synthesis of monoester and diester waxes was found both in the peroxisomal and endoplasmic reticulum fraction. Upon daily intramuscular injection of estradiol into the females in the nonmating season, the short chain monoester waxes of the uropygial glands were replaced by long chain monoester waxes, and subsequently the monoester waxes were replaced by diester waxes. Injection of thyroxine with estradiol hastened the induction of the compositional changes including diester synthesis. Similar changes, including the synthesis of the female pheromones, were induced in the uropygial glands by the hormone treatment of males that do not normally produce diesters at any time during their life cycle. The structure and composition of the diesters induced by hormone treatment of both males and females were identical to those of the female pheromones produced during their mating season. Electron microscopic examination of diaminobenzidine-treated glands showed that peroxisomes proliferated in the gland of the females in the mating season and in the estradiol-treated males that produce the diesters.

Animals↗
PubMed1991

Developmental changes in the expression of S-acyl fatty acid synthase thioesterase gene and lipid composition in the uropygial gland of mallard ducks (Anas platyrhynchos).

Developmental changes in the composition of the uropygial gland secretory lipids of the postembryonic mallard ducks (Anas platyrhynchos) were determined. During the first 3 weeks after hatching, the composition of the secretory lipids remained constant; the lipids consisted of long-chain wax esters composed of a complex mixture of n-, monomethyl, and dimethyl fatty acids esterified to n-C16 and n-C18 fatty alcohols. Afterward, as the ducks began to acquire adult feathers, short-chain wax esters composed of 2- and 4-monomethyl fatty acids began to appear with 2-methylhexanoyl and 4-methylhexanoyl as the major acyl components; esters of short-chain monomethyl fatty acids (less than or equal to C12) constituted 90% of the lipids when the ducks were 2 months old and had acquired adult plumage. The appearance of the short-chain acids in the acyl portion of the wax esters was accompanied by the appearance of S-acyl fatty acid synthase thioesterase, which can hydrolytically release short-chain acids from fatty acid synthase in the gland. Northern blot analysis showed that the gland-specific thioesterase gene transcripts began to appear in the gland only 3 weeks after hatching. The appearance of the transcripts and immunologically detectable thioesterase protein reached maximum levels 2 months after hatching, with the acquisition of the adult plumage. Thus, the developmental changes in lipid composition correlated with the changes in the level of expression of the thioesterase gene. Expression of other gland-specific genes has been previously found to begin just prior to hatching. The gland-specific thioesterase is the first case of delayed expression of a gland-specific gene.

Animals↗
PubMed1986

Saddle deformity. Posttraumatic interosseous-lumbrical adhesions: review of eighty-seven cases.

Trauma to the hand can result in adhesions between the interosseous and lumbrical muscles with subsequent painful impingement on the deep transverse metacarpal ligament during intrinsic contraction. If these adhesions also develop between the intrinsic muscles and the deep transverse metacarpal ligaments or metacarpophalangeal capsule, discomfort may be produced by stretching of the intrinsic tendons. Release of these adhesions, partial resection of the ligament, and early mobilization can produce relief of the symptoms. Eighty-seven cases are reviewed with respect to causes, diagnosis, and treatment.

Adolescent↗
PubMed1975

Studies of ultramicrostructure in relation to disaccharidase activity in the jejunal mucosa.

Ultramicrostructural changes of the mucosa of the small intestine were studied in relation to the alterations of the lactase activity, measuring the height of microvilli by electron microscopy and the enzyme activity by the method of Dahlqvist. Studies with clinical cases revealed that the height of microvilli correlated with the lactase activity significantly (p less than 0.01), and that patients with relatively higher microvilli had a correspondingly higher activity of lactase. In animal experiments an increase of lactase activity by lactose load feeding and low calorie feeding resulted in a raise in the height of microvilli. It was concluded that lactase deficiency in adults and in various gastrointestinal diseases, where no histological abnormality was observed by light microscopy is perhaps due to shortening of the microvilli of the mucosa. It was speculated that the microvillous change and the sequential hypolactasia may be the initial ultramicrostructural and enzymatic alteration in the diffuse disease of the small intestine.

Adult↗
PubMed1975

Studies on the etiology of milk intolerance in Japanese adults.

1. The incidence of milk intolerance is approximately 19% in Japanese adults when 200 ml of milk is given. However, a much greater incidence was assumed when considered under the criteria of Western standard. 2. The lactase activity was significantly greater in milk drinkers than non-drinkers. And, internationally, the active is higher in those nationalities whose milk consumption is greater. 3. Lactase is an adaptive enzyme and rather easily induced by lactose load feeding in animals. From the data of our own and of the literature, it was further confirmed that environmental factors play a more important role than genetic factors in the etio-pathogenesis of milk intolerance.

Adolescent↗