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Biomedical subjects

R Liang

Publications and source records attributed to R Liang.

At least 253 records · Page 14Linked to original sources
PubMed1993

Detection of immunoglobulin gene rearrangement in lymphoid malignancies of B-cell lineage by seminested polymerase chain reaction gene amplification.

Seminested polymerase chain reaction (PCR) was used to amplify the DNA fragments of the complementarity-determining region 3 of the immunoglobulin (Ig) gene heavy chain from the malignant cell specimens of patients with leukemias and lymphomas of B-cell lineage. Two different pairs of primers were used sequentially. Twenty of the 27 (74%) acute lymphoblastic leukemia (ALL) patients, 14 of 19 (74%) chronic lymphocytic leukemia (CLL) patients and eight of 20 (40%) non-Hodgkin's lymphoma (NHL) patients, who had rearrangement of the Ig gene heavy chain by Southern analysis, were positive by the seminested PCR. False-negative results appeared to occur more commonly in cases of lymphoma. The PCR analysis was also less likely to be positive if one-stage PCR studies with either pair of primers were both negative. The seminested PCR technique was found to have a high sensitivity of detecting malignant cells at the level of 0.02%. The clinical application of this assay needs to be investigated further.

Base Sequence↗
PubMed1993

Effective salvage therapy using all-trans retinoic acid for relapsed and resistant acute promyelocytic leukemia.

All-trans retinoic acid (ATRA) has been shown to be active against acute promyelocytic leukemia (APL). Six patients with APL, either in relapse or resistant to initial chemotherapy were reinduced with ATRA 100 g/m2/day for 6 weeks. Complete remission was achieved in all six of them. Side effects were seen in two of them. ATRA appears to provide a relatively safe and reliable means to induce a complete remission in patients with refractory or relapsed APL.

Adolescent↗
PubMed1993

Childhood acute lymphoblastic leukaemia presenting with relapsing hypoplastic anaemia: progression of the same abnormal clone.

A 13-year-old girl presented with two spontaneously reversible episodes of marrow hypoplasia. She subsequently developed acute lymphoblastic leukaemia (ALL) 8 months later. Southern analysis showed identical clonal immunoglobulin heavy chain gene rearrangement bands in the leukaemic cells as well as the marrow cells obtained at the two hypoplastic episodes. Hypoxanthine phosphoribosyl transferase polymorphism studies showed that the ALL blast cells, bone marrow and peripheral blood cells during the two hypoplastic episodes all exhibited clonal haematopoiesis with the same X-chromosome inactivated. This case provides strong evidence that aplastic anaemia and ALL may represent evolution of the same abnormal clone.

Adolescent↗
PubMed1993

Bone marrow transplantation for thalassemia in Hong Kong: the early experience.

The first experience of bone marrow transplantation (BMT) for thalassemia in Hong Kong is reported. Of the three children transplanted using a matched allogeneic donor, two have been surviving disease free 291 and 256 days post-BMT respectively. The other child rejected the graft and remained transfusion dependent. Mild graft versus host disease occurred in one of the children which subsided on cyclosporin A alone. The regimen-related toxicities were mild and easily manageable. Thus the result is encouraging and the procedure is now accepted as an option of treatment for good risk patients in Hong Kong.

Bone Marrow Transplantation↗
PubMed1992

Percutaneous transluminal coronary angioplasty in a patient with paroxysmal nocturnal hemoglobinuria.

Paroxysmal nocturnal hemoglobinuria (PHN) is an acquired chronic hemolytic anemia associated with an unusual susceptibility to hemolytic crisis, infection, and venous thrombosis which would be aggravated by a number of factors including surgery. We report a case of PHN undergoing percutaneous transluminal coronary angioplasty and discuss the corresponding perioperative management.

Adult↗
PubMed1992

Non-aggressive therapy for chronic myeloid leukaemia in blastic transformation.

A total of 40 patients presenting with chronic myeloid leukaemia in blastic transformation were treated with a non-aggressive chemotherapy regimen consisting of vincristine, cytosine arabinoside and thioguanine. Remissions were achieved by 3/10 (30%) patients displaying lymphoid transformation (remission duration, 2, 3, and 5 months, respectively) and by 5/30 (17%) subjects exhibiting myeloid changes (duration 2+, 4, 4, 5 and 7 months, respectively). Myelosuppression was the major toxicity and non-haematological toxicities were mild and acceptable. The median survival of patients exhibiting lymphoid and myeloid blastic transformation as measured from the time of transformation was 6 and 3 months, respectively, but the difference was not statistically significant. Three subjects displaying lymphoid transformation and five showing myeloid changes survived for greater than 12 months after the time of transformation.

Acute Disease↗
PubMed1992

Translocation (12;17)(p11-12;q11-12): a recurrent primary rearrangement in acute leukemia.

We identified two patients with acute leukemia in relapse (one lymphoblastic and the other with evidence of mixed lymphoid-myeloid differentiation) with t(12;17)(p12;q11) as the primary karyotypic abnormality. There are six previously reported cases of acute leukemia with an identical or similar translocation. To our knowledge, t(12;17) has not been reported in other forms of neoplasia. A review of these cases suggests that t(12;17) carries a poor prognosis.

Adolescent↗
PubMed1992

Quantification and cellular localization of ovine placental lactogen messenger ribonucleic acid expression during mid- and late gestation.

Ovine placental lactogen (oPL) is structurally similar to PRL, is a product of the chorionic epithelium, and has been implicated in playing a supportive role in fetal growth. This study examined the concentration and cellular location of oPL mRNA at five stages of pregnancy (days 60, 90, 105, 120, and 135) in 21 cross-bred ewes, and results were compared to maternal and fetal serum oPL concentrations, cotyledonary DNA and actin mRNA concentrations, and total fetal weight. The concentration of oPL mRNA in fetal cotyledonary tissue increased (P < or = 0.05) from day 60 (15.4 pg/micrograms total cellular RNA) to day 120 (73.7 pg/micrograms total cellular RNA) of gestation and then plateaued, whereas no significant changes occurred in the concentration of actin mRNA over the gestational ages examined. The concentration of DNA in cotyledonary tissue (micrograms per mg wet tissue) increased (P < or = 0.05) from days 60 through 120 and remained constant through day 135, such that when oPL mRNA was expressed on a picogram per microgram DNA basis, no stage of gestation effect (P > or = 0.10) was observed. The maternal serum oPL concentration increased (P < or = 0.05) from day 60 (7.1 ng/ml) to day 105 (417.7 ng/ml), followed by a large but nonsignificant (P > or = 0.10) increase in maternal serum oPL occurring on day 135 (902.0 ng/ml). Fetal serum oPL concentrations increased (P < or = 0.05) from day 60 (11.0 ng/ml) to day 90 (29.0 ng/ml) and then remained relatively constant. Maternal serum oPL (r = 0.68; P < or = 0.01) and cotyledonary oPL mRNA levels (r = 0.61; P < or = 0.05) were correlated with total fetal weight when adjusted for fetal number and gestational age, and together accounted for 80.6% (r2 value) of the variation found in total fetal weight. The correlation between fetal serum oPL concentrations and total fetal weight was nonsignificant (P < or = 0.10). Examination of placentome cross-sections by immunocytochemistry and in situ hybridization at the five gestational ages indicated that the chorionic binucleate cell was the sole source of oPL. These data provide evidence that, like maternal serum concentrations of oPL, oPL mRNA expression by chorionic binucleate cells increases until late gestation, whereas fetal serum concentrations of oPL plateau during midgestation.(ABSTRACT TRUNCATED AT 400 WORDS)

Actins↗