PubMed Health⌕ Search

Biomedical subjects

P R Lam-Po-Tang

Publications and source records attributed to P R Lam-Po-Tang.

At least 19 recordsLinked to original sources
PubMed2001

Distribution of FMR1 and FMR2 alleles in Javanese individuals with developmental disability and confirmation of a specific AGG-interruption pattern in Asian populations.

The number of trinucleotide repeats in the 5' untranslated regions of the FMR1 and FMR2 genes was determined by PCR in 254 Fragile XA-negative Javanese male children with developmental disabilities. The distribution of FMR1 and FMR2 trinucleotide repeat alleles was found to be significantly different in the Indonesian population with developmental disability compared to that in developmentally disabled populations in North America and Europe (p & 0.021). Sequence analysis was performed on the trinucleotide repeat arrays of the 27 individuals with FMR1 alleles in the 'grey zone' (35-54 repeats). A repeat array structure of 9A9A6A9 was found in 16 unrelated individuals with 36 repeats, confirming earlier observations in intellectually normal Japanese. We propose that this FMR1 array pattern is specific for Asian populations and that Javanese and Japanese populations arose from a single progenitor population.

Alleles↗
PubMed1997

Suppression of HIV replication in vitro by CD8+ T-cells from HIV-infected and HIV-seronegative individuals.

The inhibitory effect of CD8+ T-cells from HIV-infected or HIV-seronegative individuals on HIV replication in the naturally-infected CD4+ T-cells in vitro was examined. Not only autologous CD8+ T-cells from HIV-infected individuals but also allogeneic CD8+ T-cells from HIV-seronegative individuals prevented or delayed HIV replication, even in transwell cocultures using a semi-permeable 0.45 micron filter. The level of the inhibitory effect of allogeneic CD8+ T-cells from the HIV-seronegative individuals on the HIV replication was varied among CD4+ T-cells obtained from HIV-infected individuals used. The results suggested that CD8+ T-cells from HIV-seronegative individuals as well as HIV-infected individuals could produce some cytokine(s) which suppress HIV replication in vitro. The sensitivity to the cytokine(s) might be variable among HIV strains, depending on differences in the nucleotide sequence of different HIV-1 strains. Further studies of control of HIV replication by CD8+ anti-HIV cytokine(s) should provide new strategies for the therapy of HIV infection.

CD8-Positive T-Lymphocytes↗
PubMed1994

Comparison of cord blood and adult blood lymphocyte normal ranges: a possible explanation for decreased severity of graft versus host disease after cord blood transplantation.

Lymphocyte subpopulations in cord blood (CB; collected at birth from full-term babies) were compared with that of adult blood (AB) and found to contain significantly different numbers and percentages of lymphocyte subpopulations. The absolute lymphocyte count was greater in CB (4.8 +/- 1.1 x 10(9)/L) than in AB (1.69 +/- 0.38 x 10(9)/L), with CB having significantly higher absolute numbers of lymphocyte subsets even though CB percentages were significantly lower. Significant differences in percentages were found between cord and adult T cells (CB 58% vs AB 74%), NK cells (CB 19% vs AB 7%) and their subsets. CD38, a marker of activation and immaturity, was present on virtually all cord T cells and approximately half the adult T cells. CD45RA, a marker considered to define unprimed or naive cells, was expressed on 82% of cord lymphocytes as compared with 48% in AB. CD45RO was expressed on 16% of CB lymphocytes and 49% of AB lymphocytes. Cord blood contains a higher percentage and total number of immature and immunologically naive lymphocytes than AB.

Adolescent↗
PubMed1993

Geographical distribution of acute lymphoblastic leukaemia subtypes: second report of the collaborative group study.

Childhood acute lymphoblastic leukemia (ALL) T and B precursor subtypes have been identified by standardised immunophenotyping in different geographic and ethnic settings. Comparison of the relative frequencies and estimated incidence rates of the major subtypes indicates very similar values, with the striking exception of black childhood populations in Africa in which there appears to be a significant and selective deficit in the incidence of the common (B-cell precursor) subset of ALL. There is suggestive evidence for a similar bias in ALL subtypes in South Africans of mixed ethnic origin and in Mapuche Indians from Chile. Several interpretations of these data are possible but the one favoured attributes these differences primarily to socio-economic factors and patterns of infection in infancy.

Adolescent↗
PubMed1991

Localization of human glandular kallikrein-1 gene to chromosome 19q13.3-13.4 by in situ hybridization.

Humans possess 3 fully characterized kallikrein-like genes. The gene expressed in kidney, pancreas and salivary gland (KLK), and the gene encoding prostate-specific antigen (APS) have been localized to chromosome 19q13.2-qter. The present study describes the localization of the remaining gene, hGK-1, which has highest homology to and a similar tissue specificity of expression as the APS gene. Using a [3H]-labeled probe derived from a hGK-1 genomic clone, we demonstrated hybridization confined to the q13.3 and q13.4 bands of chromosome 19 and suggest that kallikrein genes may possibly be located near the border of these two bands.

Chromosome Mapping↗
PubMed1991

Immunomagnetic bone marrow purging of common acute lymphoblastic leukemia cells: suitability of BioMag particles.

Immunomagnetic bone marrow purging is becoming a widely used technique in many bone marrow transplant centres. Most centres use Dynabead magnetic particles to facilitate the procedure. The suitability of a novel magnetic particle (BioMag) for immunomagnetic purging was addressed in this study. Common acute lymphoblastic leukemia (ALL) cells were targeted using CD9 and CD10 mouse monoclonal antibodies prior to attachment of magnetic particles coated with anti-mouse immunoglobulin and depleted with samarium cobalt magnets. Immunofluorescent and clonogenic assays capable of measuring more than four log depletions of the Nalm 6 cell line showed that a single cycle of purging reduced target cells by 3.1 +/- 0.9 BioMag particles and 1.8 +/- 1.0 logs with Dynabeads. A second cycle of purging was advantageous, increasing target cell depletions to more than 4.5 logs with either particle type. Bone marrow granulocyte-macrophage colony-forming units were not significantly reduced. The results indicate that BioMag particles can be used for the efficient depletion of common ALL cells from bone marrow for transplantation.

Antibodies, Monoclonal↗
PubMed1990

Ring chromosomes in hypodiploid and hypotetraploid clones from an elderly patient with plasma cell leukemia.

We describe a 77-year-old woman who had with what appears to be the first case of plasma cell leukemia (PCL) with a ring chromosome of variable size. Of the three clones evident, two of them were abnormal: a 41,X,-X hypodiploid clone with rings of two different sizes, and a 81-82,XX hypotetraploid clone with a double-sized dicentric ring or variable double rings. Additional structural and numerical abnormalities included a 14q+ marker, deletions of two chromosomes 1 and monosomies 8 and 13, all previously reported in PCLs. Ring chromosomes have been associated with a poor prognosis, especially in elderly patients. The patient declined active treatment and died within 4 weeks of diagnosis.

Aged↗
PubMed1990

Localization of human cardiac beta-myosin heavy chain gene (MYH7) to chromosome 14q12 by in situ hybridization.

The genes coding for each human cardiac myosin heavy chain (alpha-MHC and beta-MHC, MYH6 and MYH7, respectively) are tightly linked and the alpha-MHC gene has been assigned to chromosome 14. In order to provide a more precise regional localization, in situ hybridization experiments were carried out using a 3H-labeled probe derived from a beta-MHC genomic clone. The results demonstrated that the human cardiac MHC genes are located within the q12 band of chromosome 14.

Chromosome Banding↗
PubMed1990

Comparison of thromboplastins using the ISI and INR system.

Twelve thromboplastins were tested against a secondary reference thromboplastin (human brain CRM BCR No. 147) or a tertiary house standard (human brain thromboplastin) with plasmas from normal healthy individuals and patients on oral anticoagulant therapy. The relationship between the prothrombin ratios of the thromboplastins tested versus the reference reagent was either a straight or curved line. The International Sensitivity Index (ISI) was estimated for each of the test thromboplastins and these ranged from 0.98 to 2.24. Some ISIs stated by manufacturers were different from our results. Thromboplastins with a high ISI showed a loss of sensitivity in assessing the level of anticoagulation at the upper end of the therapeutic range. In addition, the 95% Confidence Interval (CI) of the ISI estimations were widest for thromboplastins with the highest ISIs. Conversion of the prothrombin ratio to International Normalized Ratio (INR) was most accurate with the Australasian Reference Thromboplastin (ART) and least accurate with reagents having an ISI of 2.00 and over. Thromboplastins with an ISI between 1.10 and 1.50 may be adequate for the control of oral anticoagulant therapy, but were less accurate than a thromboplastin with an ISI approximating 1.00. Factors other than ISI should be considered in the choice of a thromboplastin, in particular a measurement of the accuracy of the ISI estimation such as the 95% confidence interval estimation used here.

Administration, Oral↗
PubMed1989

Duplication of 5q11.2----q13.1 from a familial (5;20) balanced insertion.

A 2-year-old boy with gross motor delay and few minor anomalies has a pure duplication of a small segment of chromosome 5q11.2----q13.1. A balanced insertion of this 5q segment into chromosome 20q proximal to the centromere has been found in his father, uncle, and paternal grandmother.

Abnormalities, Multiple↗
PubMed1987

Deletion 15q21.1----q22.1 resulting from a paternal insertion into chromosome 5.

A 15 month old boy with an interstitial deletion 15q derived from a paternal insertion (5;15)(q31.3;q21.1q22.1) is described and compared with one other reported case. A beak like nose with hypoplastic nasal alae, a thin upper lip, failure to thrive in infancy with later onset of obesity, and severe mental retardation are features common to both.

Abnormalities, Multiple↗