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Biomedical subjects

A D Yang

Publications and source records attributed to A D Yang.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of activity of epiphyseal plates in growing males and females.

To investigate the age-related activity of the epiphyseal plates, a retrospective study of (99m)Tc-methylene diphosphonate bone scans was undertaken. The study comprised 81 males and 46 females aged 2 weeks to 24 years. The total percentage (%) whole-body (ratio of total physis activity to whole-body activity) and the regional % whole-body (ratio of physis activity of one region to whole-body activity) were derived. The ratio of physis activity of one region to the total physis activity was defined as % physis. Before age 12, total physis activity was found to contribute about 10% to whole-body activity. All total and regional % whole-body activities followed sigmoid curves with age. The differences of the parameters (transition centers and widths) suggested that there might be a later and longer period for the disappearance of physis activity in males than in females. For all the regions, % physis changed little with age until after puberty. At age <1, the proportion of bone activity in the body was about 30-35% for skull, 20-25% for lower limbs, and 5-15% for the rest of the regions. The maximal changes during growth occurred in the skull and the lower limbs. The age-related changes of physis activity during growth reflect a combination of the potential of bone to grow and the processes of bone growth and bone turnover. Bone scintigraphy is useful in understanding the changes of physis activity during growth.

Adolescent↗
PubMed2006

Bilateral retrocaval ureters with IVC duplication.

We report a rare case of bilateral retrocaval ureters associated with duplicated inferior renal cava. A 69-year-old woman was sent to our emergency room for abdominal pain. Multidetector computed tomogram with multiplanar reconstruction revealed duplicated inferior renal cavae and the bilateral ureters were positioned behind the duplicated inferior vena cava. To our knowledge, coexistence of bilateral retrocaval ureters and duplicated inferior renal cavae has not been reported in the literature.

Aged↗
PubMed2001

Oncogenes in Ras signalling pathway dictate host-cell permissiveness to herpes simplex virus 1.

The importance of herpes simplex viruses (HSV) as human pathogens and the emerging prospect of using mutant derivatives of HSV-1 as potential anti-cancer therapeutics have necessitated a thorough investigation into the molecular basis of host-cell permissiveness to HSV. Here we show that NIH-3T3 cells transformed with the oncogenes v-erbB, activated sos or activated ras become significantly more permissive to HSV-1. Inhibitors of the Ras signalling pathway, such as farnesyl transferase inhibitor 1 and PD98059, effectively suppressed HSV-1 infection of ras-transformed cells. Enhanced permissiveness of the transformed cells was linked to the inhibition of virus-induced activation (phosphorylation) of the double-stranded RNA-activated protein kinase (PKR), thereby allowing viral transcripts to be translated in these cells. An HSV-1-derived oncolytic mutant, R3616, was also found to infect preferentially both transformed cells and PKR-/- (but not PKR+/+) mouse embryo fibroblasts. These observations suggest that HSV-1 specifically targets cells with an activated Ras signalling pathway, and have important ramifications in the use of engineered HSV in cancer therapy, the development of strategies against HSV infections, and the controversial role of HSV in human cancers.

3T3 Cells↗
PubMed2000

Relapsing pancreatitis in a child duplication in an aberrant pancreatic lobe.

An aberrant pancreatic lobe associated with an enteric duplication cyst is a rare cause of relapsing pancreatitis in childhood. We present an 8-year-old boy with relapsing pancreatitis caused by this rare congenital foregut anomaly. The computed tomography (CT) findings revealed an unusually long segment of aberrant pancreatic lobe arising from the pancreatic neck, projecting anteriorly at a distance to a cystic duodenal duplication and appearing as an inflammatory mass. There has been no previous report of this unusual appearance on CT. Appreciation of the relevant anatomy provided by CT led to the successful management of this surgically-treatable cause of relapsing pancreatitis.

Acute Disease↗
PubMed1999

A huge cystic hygroma of the neck associated with intraventricular haemorrhage in a term neonate.

We report on a female term neonate who presented with a huge cystic hygroma of the right neck associated with intraventricular haemorrhage as demonstrated by computerized tomography and magnetic resonance imaging studies. She underwent extraventricular drainage and excision of the neck mass with stable postoperative condition. Psychomotor retardation was found thereafter. To our knowledge, the association of a large cystic hygroma of the neck with intracranial haemorrhage has not been reported previously. The possible mechanism of the occurrence of the haemorrhage is discussed.

Central Venous Pressure↗
PubMed1994

Preliminary study on bcr rearrangement in leukemia.

Southern blot analysis was conducted in 15 patients by using a 1.2 Kb Hind III/Bgl II fragment from the 3' end of the bcr region and a 2.0 Kb Bgl II/Hind III fragment from the 5' end of the bcr as probes. Of the 15 patients in our group, 11 with chronic, myelocytic leukemia (CML), 3 with Ph-negative acute lymphocytic leukemia (ALL), one with myelodysplastic syndrome (MDS). Bcr rearrangements were detected in 9 patients with CML and were negative in the rest of the patients. The results showed that the identification of bcr rearrangement was very important in the diagnosis of Ph-positive leukemias.

Adolescent↗
PubMed1994

A chromosome study on 97 cases of acute nonlymphocytic leukemia M2.

Chromosomal studies were performed in the same laboratory on 97 untreated cases of de novo acute nonlymphocytic leukemia M2. The overall incidence of chromosomal abnormality was 70.1% (68 out of 97 cases), which was higher in children (84.2%) than in adults (61%). The male to female chromosomal abnormality ratio was nearly the same (male 71% and female 68.4%, P > 0.05). Hypodiploidy was the most common numerical abnormality (39%) and t (8; 21) was the most common structural abnormality (48.1%). In the patients with t(8; 21), 64.5% (20 out of 31 cases) male lost chromosome Y (-Y) and 33% (5 out of 15 cases) female lost one chromosome X (-X).

Adult↗
PubMed1994

The morphological studies on M2/t(8; 21) acute nonlymphocytic leukemia.

Bone marrow studies including morphological, morphometrical and ultrastructural aspects were performed in 35 patients with M2/t(8; 21) and 23 patients with M2/NN. It was found that M2/t(8; 21) patients had higher cellularity in bone marrow. Type (II) myeloblast cells were predominant among myeloblasts. Deformation of nuclei, nucleocytoplasmic asynchronism and dysmegakaryocytopoiesis were more evident in M2/t(8; 21) than in M2/NN patients.

Bone Marrow↗
PubMed1994

Suprahepatic gallbladder with agenesis of the right lobe of the liver: report of a case.

An unusual case of suprahepatic gallbladder with agenesis of the right lobe of the liver is reported. The anomalous position of the gallbladder was detected by ultrasonography. It was shown to be distended and to contain sludge. The suprahepatic location with agenesis of the right lobe of the liver was preoperatively confirmed by computed tomography. The patient underwent cholecystostomy with drainage and had an uneventful recovery. The postoperative follow-up examinations, including endoscopic retrograde cholangiopancreatography, ultrasonography, arteriography and portography, all added information rarely reported in the literature and helped in the understanding of this uncommon case. Laparoscopic cholecystectomies are widely used but such a procedure was contraindicated in this case because of the ectopic position and inaccessibility of the gallbladder.

Congenital Abnormalities↗
PubMed1993

Detection of the BCR/ABL fusion gene in chronic myeloid leukemia by RNA polymerase chain reaction.

The bcr/abl fusion gene in 20 patients with chronic myeloid leukemia (CML) was detected by RNA polymerase chain reaction, which used mRNA as the starting material to generate cDNA with reverse transcriptase followed by PCR amplification (RNA/PCR). Amplification of a sequence spanning the bcr/abl junction region was achieved by using peripheral blood cells as the source of mRNA from all 20 patients with CML, including 3 cases of Ph (-) CML, and cell line K562 was derived from patients with CML. No amplification was seen when mononuclear cells from 3 normal individuals, 2 patients with lymphoma and cell line HL-60 were used. The presence or absence of bcr exon 3 in the fusion mRNA was determined by the size of the amplified fragments. Of the 20 CML patients, 15 showed only the 165-bp amplified band (indicating retention of bcr exon 3), one showed only the 90-bp amplified band, and 4 showed both 165-bp and 90-bp bands. Both bands were seen more frequently in blast crisis than in remission and chronic phase.

Adolescent↗
PubMed1993

Clinical and prognostic investigations on M2/t(8;21) acute nonlymphocytic leukemia.

Clinical and prognostic investigations were conducted in 46 cases of M2/t(8;21) leukemia and 29 cases of M2/NN patients. Results showed that most patients with M2/t(8;21) were young males with higher incidence of extramedullary infiltrations. Complete remission rate was higher but with earlier relapse. The prognosis of patients with M2/t(8;21) with loss of one sexual chromosome was poor.

Adult↗
PubMed1991

BCR rearrangements in Ph positive chronic myelocytic leukemia.

Nine patients with chronic myelocytic leukemia (CML) and 1 patient with erythroleukemia were studied with 3'bcr and 5'bcr probes using Southern blot hybridization technique. Bcr rearrangements were detected in 8 patients with CML in the chronic phase, and bcr rearrangement was deduced to have existed in a CML patient in blastic crisis. However, no abnormal fragment was found in the patient with erythroleukemia. 3'bcr and 5'bcr probes combined with proper restriction enzymes were believed to be of great value in determining bcr rearrangements in Ph positive CML.

Adolescent↗
PubMed1990

Monoclonal anti-human T cell antibody and PAP-s conjugate--preparation and selective cytotoxic properties on leukemic cell.

Pokeweed antiviral protein (PAP-s) was prepared from seeds of Phytolacca americana. Monoclonal antibody against human pan-T lymphocyte Wu71 was linked to PAP-s by a disulfide bond. The results of SDS-PAGE, double immunodiffusion of active monoclonal antibody and PAP-s showed that the conjugate was highly cytotoxic to the human T-leukemic cell line CEM, but not to antigen-negative cell line SP2/O. At a concentration of 10(-9) mol/L, 76.4% of the target cells were killed, as compared with 10.1% at 10(-9) mol/L of free PAP-s. Treatment of the CEM cells with conjugate at 10(-9) mol/L reduced their rate of protein synthesis by 72.4%, as determined with 14C-leucine incorporation. The immunotoxin may be useful for the in-vitro eradication of leukemic cells in autologous bone marrow transplantation to leukemia patients.

Antibodies, Monoclonal↗
PubMed1990

Cytogenetic study on acute lymphoblastic leukemia.

During 1987-1988 cytogenetic studies were performed in 30 patients with acute lymphoblastic leukemia (ALL). Of the 30 patients 15 (10 children and 5 adults) were found to have abnormal karyotypes including 8 cases (27%) of pseudodiploidy, 2 cases (7%) of hypodiploidy, one case (3%) of low-hyperdiploidy (modal number 47-50), and 4 cases (13%) of high-hyperdiploidy (modal number greater than 50). Immunological classification was performed by using monoclonal antibodies in 26 patients, and the most common immunophenotype was C-ALL. The patients with abnormal karyotypes were more likely to be NuLL-ALL (6 in 14) as compared with patients with normal karyotype (1 in 12). In our series, there was no significant difference between the patients with and without cytogenetic changes in regard of clinical findings such as FAB classification, the rate of complete remission, percentage of lymphoblasts in bone marrow cells and blood picture.

Adolescent↗
PubMed1989

Characteristic of marrow culture and clinical relevance in leukemia with 8/21 translocation.

Karyotypes and in vitro cultures of bone marrow cells from eleven patients with acute myelogenous leukemia M2 type were performed. 8/21 translocation was found in 5 patients. In all of them the cultures in vitro shared one characteristic, i.e., clusters were small and less in number. These patients could relatively easily obtain complete remission. The similarity of CFU-GM in patients with t (8; 21) may be another important biological phenotype.

Adolescent↗
PubMed1986

Complete nucleotide sequence of an EcoRI-1.35-kb repeated element of mouse: homology with the cellular flanking region between two intracisternal A-particle genes.

The complete DNA sequence (1369 bp) of an EcoRI-1.35-kb repeated element (ER-1) of the mouse BamHI family has been determined. Analysis of this sequence revealed that a portion of the 3' end (positions 1277-1369) of ER-1 was found to share 91% homology with the flanking cellular sequence between two adjacent intracisternal A-particle (IAP) genes, IAP-19A and IAP-19B.

Animals↗