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Biomedical subjects

Y Yufu

Publications and source records attributed to Y Yufu.

49 records · Page 3Linked to original sources
PubMed1991

Recent studies on scrub typhus and Rickettsia tsutsugamushi in Shandong Province--China.

In an outbreak of scrub typhus occurred 138 cases in 1986 in Menying County of Shandong Province of China which were confirmed through clinical and epidemiological surveys and laboratory techniques. In the endemic areas, the predominant species of mite is Leptotrombidium (L.) scutelarae and the predominant rodent is Apodemus agrarius, which may be the main vector and reservoir. Several strains of Rickettsia tsutsugamushi (R.T.) were obtained from mites, wild mice and patients, of which 3 human strains (SDH871, SDH875, SDH878) cause illness and some deaths in mice, except SDH871. The LD50 of SDH878 is 3.4. Cross-protection was observed among the strains, SDH871, SDH878, and prototype strain karp. Also the antibodies in mucoid peritoneal fluid were detectable with high titer. Shandong R.T. belongs to the serotype of the Gilliam strain.

Adult↗
PubMed1991

Two bcr/abl fusion gene products, P210bcr/abl and P190bcr/abl, are equally sensitive to the protein tyrosine phosphatase of mature granulocytes.

Two bcr/abl fusion gene products with tyrosine kinase activity have been found in two phenotypes of Philadelphia chromosome (Ph1)-positive leukemia. P210bcr/abl (P210) is associated with Ph1-positive chronic myelogenous leukemia (CML), while P190bcr/abl is associated with Ph1-positive acute leukemia. We compared the susceptibility of 32Pi-labeled P210 from K-562 cells and P190 from MR-87 cells to protein tyrosine phosphatase (PTPase). PTPase, present in the lysate of mature granulocytes from CML patients as well as in the lysate of these cells from normal subjects, effectively dephosphorylated the CML-associated P210 and the acute leukemia associated P190. This PTPase activity was specifically inhibited by ZnCl2; it was not present in lymphocyte lysates, and was not inhibited by neutralization with anti-CD45 antibody. Since P210 and P190 were equally sensitive to the PTPase, the difference in leukemic phenotypes associated with the expression of these two tyrosine kinases cannot be explained by the differential dephosphorylation of P210 and P190.

Cellular Senescence↗
PubMed1990

Enhanced synthesis of heat shock proteins and augmented thermotolerance after induction of differentiation in HL-60 human leukemia cells.

The effects of the induction of differentiation were investigated on the expression of heat shock proteins (hsps) and thermotolerance. The synthesis of the major hsps in response to heat stress was markedly enhanced in HL-60 human leukemia cells after differentiation. An increased amount of mRNA transcripts for hsp 70 was also noted. In addition, induction of differentiation resulted in acquisition of greater resistance to heat, which may be advantageous since cells in the peripheral blood must survive many stresses.

Blotting, Northern↗
PubMed1990

The transferrin receptor system is not involved in the pathogenesis of hematological disorders with 3q inversion.

To clarify the idea that an alteration of the transferrin receptor (TF-R) gene, localized to 3q26, may be of pathogenetic significance in hematological disorders with 3q anomaly, we studied the TF-R systems of erythroblasts from both functional and genetic aspects. The patient described here had refractory anemia with an excess of blasts (RAEB), with paracentric inversion, inv(3)(q21q26). The patient had the characteristic findings of micromegakaryocytosis and thrombocytosis, with giant platelets. There was no functional abnormality of TF-R as far as number of binding sites, affinity, molecular weight, or recycling kinetics were concerned. Furthermore, we could not recognize any rearrangement of the TF-R gene with Southern blot analysis. These data suggest that TF-R is not involved in the pathogenesis of leukemogenesis and thrombocytosis of the disease.

Chromosome Inversion↗
PubMed1990

Abnormality of platelet membrane glycoprotein GPIIb in a myelodysplastic syndrome with 3q inversion presenting with marked dysmegakaryopoiesis.

Platelet membrane glycoproteins were analyzed in a case of myelodysplastic syndrome with inv(3) (q21q26) presenting with prominent dysmegakaryopoiesis by three different labelling techniques for surface proteins. Markedly decreased level of platelet membrane glycoprotein GPIIb was observed in the patient's platelets by terminal sialic acid labelling method, whereas no significant changes in the levels of glycoproteins including GPIIb could be detected either by penultimate galactose labelling or by tyrosine/histidine labelling. These results indicate a decreased sialylation of GPIIb in the patient's platelets, implying aberrant process in thrombopoiesis in the disease.

Bone Marrow Examination↗
PubMed1990

[Two cases of familial occurrence of aplastic anemia].

It is quite rare that aplastic anemia except Fanconi's type occurs in members of a single family. Here we reported two patients with aplastic anemia, a 14-year-old female and a 49-year-old her mother. In both cases, hematological findings were compatible to that of a typical aplastic anemia. In the case of daughter, CFU-E formation of control bone marrow cells was significantly inhibited by the addition of the patient's bone marrow cells, suggesting the presence of cellular immune mechanism. In the case of mother, no inhibitory activity on CFU-C formation of control bone marrow cells was detected in the patient's serum, though the ratio of helper/suppressor T lymphocytes in the peripheral blood was increased. We could not sufficiently clarify the common immune mechanism causing aplastic anemia in both cases. It was noticeable, however, that both cases share HLA DR2, which is frequently found in patients with various autoimmune diseases and is believed to relate closely to the pathogenesis of autoimmune diseases. This evidence suggests the possibility that genetically inherited susceptibility may also be the important factor for causing aplastic anemia.

Adolescent↗
PubMed1989

Down-regulation of a Mr 90,000 heat shock cognate protein during granulocytic differentiation in HL-60 human leukemia cells.

Modulation of the synthesis of heat shock proteins in HL-60 human promyelocytic leukemia cells during differentiation was studied by metabolic labeling with [35S]methionine and Northern blot analysis. HL-60 cells were found to synthesize constitutively a high level of a Mr 90,000 protein (heat shock cognate protein, hsc90), which was very closely related to Mr 90,000 heat shock protein, hsp90, as far as molecular weight, isoelectric point, peptide maps, immunoreactivity, and encoded mRNA were concerned. Differentiation induction by dimethyl sulfoxide markedly decreased the level of the hsc90 expression, but preserved the ability to preferentially express hsp90 in response to heat stress. These results suggest distinct regulatory mechanisms of the synthesis between hsc90 and hsp90 although they are indistinguishable by conventional protein or mRNA analysis, and indicate that hsc90 has some role in cell growth and differentiation.

Cell Differentiation↗
PubMed1989

[Rapid bone marrow dissemination of gastrointestinal lymphomas after surgical resection].

We describe two cases of gastrointestinal lymphoma associated with rapid bone marrow dissemination after surgical resection. Case 1: A 73-year-old male was diagnosed as having malignant lymphoma originating from ileocaecal region (diffuse medium-sized, B cell type). Tumor (8 x 8 cm) was resected but infiltrated to the peritoneum and curative operation could not be done. Two weeks after operation, elevation of LDH, pancytopenia and bone marrow infiltration of lymphoma cells developed and he died of respiratory failure. Case 2: A 69-year-old female was diagnosed as having remnant gastric lymphoma (diffuse large, B cell type). Tumor size was 5 x 4 cm and swelling of the third lymph nodes was found, so curative operation could not be done. Two months after operation bone marrow infiltration of lymphoma cells was observed and she is now undergoing chemotherapy. Surgical resection is performed in the majority of patients with localized gastrointestinal lymphoma. But the operation of the advanced case must be carefully done, because the operative procedure may sometimes facilitate growth and metastasis of tumor.

Aged↗
PubMedDate not supplied

High constitutive expression of heat shock protein 90 alpha in human acute leukemia cells.

The constitutive expression of the genes for four heat shock proteins (hsps) was studied in leukemia cell lines, cells obtained from patients with acute leukemia, and normal blood cells by means of Northern-blot analysis. Western-blot analysis with hsp90 antibody showed that the leukemia cells contained larger amounts of hsp90 than the normal peripheral mononuclear cells. The expression of the hsp90 alpha gene was enhanced in the leukemia cell lines and the acute leukemia cells from patients as compared with the normal blood cells. In contrast, the expression of the hsp90 beta gene could hardly be recognized in either the acute leukemia cells or the normal blood cells. An increased expression of hsp70 gene was observed in only one patient. The expression of the hsp27 gene was enhanced in one-half the patients with common acute lymphoblastic leukemia. Thus, exclusively the hsp90 alpha gene was expressed highly in the leukemia cells, indicating its association with cellular proliferation.

Acute Disease↗