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Biomedical subjects

G Wong

Publications and source records attributed to G Wong.

At least 163 records · Page 9Linked to original sources
PubMed1988

Localization of the human G-CSF gene to the region of a breakpoint in the translocation typical of acute promyelocytic leukemia.

The colony-stimulating factors regulate growth, differentiation, and function of blood cells. The effect of granulocyte colony-stimulating factor (G-CSF) on myeloid leukemias is unique among colony-stimulating factors in driving the leukemic cells from a self-renewing malignant state to a mature differentiated phenotype with the concomitant loss of tumorigenicity. This property of G-CSF has led to suggestions that its absence is responsible for lack of differentiation of leukemic cells and that the therapeutic administration of G-CSF could reverse this defect and result in a cure for leukemia. Here we show that the gene coding for human G-CSF is localized to chromosome 17, bands q11.2-21. The translocation of the long arm of chromosome 17 at q12-21 to chromosome 15 is a specific abnormality occurring in a high proportion of, if not all, patients with acute promyelocytic leukemia, a disease characterized by undifferentiated myeloid cells and a dismal prognosis. Abnormalities of the regulation of a specific differentiation factor gene mediated by a specific chromosomal rearrangement may be directly implicated in the pathogenesis of human leukemia.

Chromosome Mapping↗
PubMed1988

Interleukin 4 is at 5q31 and interleukin 6 is at 7p15.

DNA probes to the human interleukin 4 (IL4) and interleukin 6 (IL6) genes have been used for in situ hybridization to normal human chromosomes and Southern blot analysis of a series of mouse-human hybrid cell lines. IL4 maps to 5q31, the same location as IL5 and other haemopoietic growth factor genes. IL6 maps to 7p15. The significance of these locations is discussed.

Chromosome Mapping↗
PubMed1988

Bone mineralization in women following successful treatment of Hodgkin's disease.

PURPOSE: Women with Hodgkin's disease in whom a cure has been achieved may be at risk for osteoporosis because of therapy-induced premature menopause. Our objective was to gather information regarding the integrity of bone mass in such long-term cancer survivors. SUBJECTS AND METHODS: Bone mineral density was measured using photon absorptiometry in five groups of women: 11 patients with Hodgkin's disease and ovarian failure (Group I); six patients with Hodgkin's disease and ovarian failure who received estrogen replacement (Group II); 15 patients with Hodgkin's disease and normal ovarian function (Group III); 16 premenopausal control subjects (Group IV); and 11 postmenopausal control subjects (Group V). All patients with Hodgkin's disease were in remission and had completed treatment more than five years earlier. RESULTS: Subjects in Group I were found to have significantly decreased radial (p = 0.0009), lumbar spine (p = 0.002), and femoral neck (p = 0.0001) bone mineral density measurements compared with those in subjects in Group IV; the bone mineral density measurements at all sites of subjects in Group I were no different than those of subjects in Group V. Subjects in Group III had bone density measurements that were similar to those in Group IV, although the radial bone mineral density value was significantly lower (p = 0.0004). Determination of serum gonadotropins and estradiol was consistent with the menstrual status defining the five groups. No secondary causes for decreased bone mineral density values could be detected, since the mean serum levels of parathyroid hormone, calcium, phosphorus, and vitamin D metabolites were similar among the groups, and all prolactin levels were normal. CONCLUSION: We have identified a new population of patients with a high risk of osteoporosis, and these results emphasize the importance of treatment-related ovarian failure in the pathogenesis of osteoporosis.

Adult↗
PubMed1988

Structure and expression of genes of GM-CSF and G-CSF in blast cells from patients with acute myeloblastic leukemia.

The hematopoietic growth factors granulocyte/macrophage colony-stimulating factor (GM-CSF) and G-CSF, available as recombinant products, stimulate the growth in culture of blasts from patients with acute myeloblastic leukemia (AML). We used cDNA probes for each gene to study the genomic organization in blast cells of 22 patients and expression in the blast cells of 18 patients. Alteration in the structure of G-CSF (two instances) and GM-CSF (two instances) was found. In two patients in whom it was possible to study DNA from bone marrow obtained at remission, the new bands detected in the leukemic cells were not found. Fifteen of 18 patients showed no RNA expression of either growth factor. Both patients with GM-CSF abnormalities as seen by Southern analysis expressed an abnormally large GM-CSF message but no G-CSF messages. One patient with an abnormal Southern pattern with G-CSF expressed normal-sized G-CSF and GM-CSF messages. The biologic significance of these findings remains to be determined. Nonetheless, the abnormal Southern patterns may prove to be useful clonal markers in the study of AML.

Adolescent↗
PubMed1987

Gene family of male-specific testosterone 16 alpha-hydroxylase (C-P-450(16) alpha) in mouse liver: cDNA sequences, neonatal imprinting, and reversible regulation by androgen.

The cDNA clone p16 alpha-1 for the male-specific isozyme (C-P-450(16) alpha)1 of testosterone 16 alpha-hydroxylase in livers of 129/J mice [Harada, N., & Negishi, M. (1985) Proc. Natl. Acad. Sci. U.S.A. 82, 2024-2028] and two additional full-length cDNAs overlapping with p16 alpha-1 (p16 alpha-2 and p16 alpha-16) were sequenced. p16 alpha-2 contained a single open reading frame of 1512 nucleotides, consisting of 71 base pairs of the 5'-noncoding region and 63 base pairs of the 3'-noncoding region with an additional poly(A) tract. From this DNA sequence, C-P-450(16) alpha was deduced to contain 504 amino acids with a calculated molecular mass of 56,948 daltons. p16 alpha-1 showed a nucleotide sequence identical with that of p16 alpha-2 but lacked nine amino acid residues from the N-terminus. Another cDNA clone, p16 alpha-16, also exhibited the same coding sequence with the exception of a 142 base pair deletion spanning from nucleotide 853 to nucleotide 994 of p16 alpha-2. This deletion seems to be a whole exon of this gene, resulting in a shift of reading frame and an early termination codon at 10 amino acid residues from the deletion. The expected translation product of this mRNA is calculated to be 294 amino acids and 33,300 daltons. The putative poly(A) addition signal AATAAA is present for all three clones, but there are polymorphisms in the start sites of polyadenylation.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1987

Stimulation of human hematopoietic colony formation by recombinant gibbon multi-colony-stimulating factor or interleukin 3.

Recently, the gene for a novel mammalian hematopoietic growth factor homologous to murine interleukin 3 was isolated from a gibbon T cell line and expressed in monkey COS cells. The factor, termed multi-colony stimulating factor (multi-CSF) or interleukin 3, is stimulatory to human target cells. We investigated the range of enriched human bone marrow and fetal liver hematopoietic progenitors responsive to multi-CSF; compared the colony types observed with those obtained in the presence of recombinant granulocyte-macrophage CSF (GM-CSF); and analyzed the effects on colony formation of combining multi-CSF with GM-CSF or granulocyte-CSF (G-CSF). The results show that multi-CSF acts as a multipoietin. Alone it stimulates the formation of colonies derived from granulocyte, macrophage, eosinophil, and megakaryocyte progenitors. In combination with erythropoietin it supports the development of both erythroid and mixed colonies. Furthermore, the data show that multi-CSF is a more potent stimulus of erythroid progenitors than GM-CSF. In combination with G-CSF multi-CSF substantially increases granulocyte colony number over the number obtained with each factor alone. We conclude that multi-CSF may prove to have important therapeutic potential in vivo as a stimulus for hematopoiesis.

Animals↗
PubMed1987

Synergism between recombinant growth factors, GM-CSF and G-CSF, acting on the blast cells of acute myeloblastic leukemia.

The genes for the hemopoietic growth factors, GM colony-stimulating factor (CSF) and G-CSF have been cloned, and recombinant material is available for both. We tested these recombinant factors for their effects on the blast cells of acute myeloblastic leukemia (AML). Culture methods are available that support both colony formation by AML blasts and the growth of blast stem cells in suspension. Recombinant GM-CSF is active in both culture systems, although to a varying degree. We found that recombinant G-CSF was also effective; however, the two recombinant factors showed striking synergism for the stimulation of blast growth of cells from five of eight AML patients. In these cases, the combination was equivalent to the stimulating activity of supernatants from the continuous cell line 5637. This conditioned medium (HTB9-CM) is considered the standard for blast growth. Blasts from one of the patients grew without added factor. In another instance, recombinant GM-CSF alone was almost as effective as HTB9-CM. In the third case, both recombinant factors were active, but synergism was not observed and their combined effect was not equivalent to that of HTB9-CM. Both GM-CSF and G-CSF were active on normal bone marrow granulopoietic progenitors, but synergism was not observed. We conclude that the marked heterogeneity observed when AML blasts are examined by other criteria is also observed when their response to growth factors is evaluated.

Acute Disease↗
PubMed1987

Localization of the G-CSF gene on chromosome 17 proximal to the breakpoint in the t(15;17) in acute promyelocytic leukemia.

The human granulocyte-colony stimulating factor gene (G-CSF) is localized at 17q11.2-q21, the region of one of the breakpoints in the 15;17 chromosome translocation specific for acute promyelocytic leukemia (APL). As G-CSF induces differentiation and loss of tumorigenicity in myeloid leukemic cells or cell lines, it was possible that the translocation in APL involved the DNA of the G-CSF coding region or its regulatory region. In situ hybridization to chromosomes with the t(15;17) from patients with the APL translocation using a G-CSF cDNA clone revealed that the coding region of this gene is proximal to the t(15;17) breakpoint on chromosome 17. Southern analysis of DNA from patients with the APL translocation showed no differences in hybridization between normal and leukemic cells. These results indicate that the G-CSF coding sequence is not disrupted by the chromosomal rearrangement characteristic of APL.

Acute Disease↗
PubMed1986

Kaposi's sarcoma and the acquired immune deficiency syndrome. Treatment with recombinant interferon alpha and analysis of prognostic factors.

Interferon alfa-2a (Roferon-A, Hoffmann-La Roche Inc., Nutley, NJ) was used to treat sequential groups of patients with Kaposi's sarcoma associated with the acquired immune deficiency syndrome (AIDS). Major antitumor effects (complete or partial responses) were observed in 38% of the patients treated initially with high-dose interferon alfa-2a and in 17% of patients in whom the dose was increased after low-dose treatment failed. A low dose of interferon alfa-2a was ineffective; one patient (3%) showed a partial response. Patients whose tumors responded to interferon treatment showed a significantly lower rate of opportunistic infection, as well as a longer survival than nonresponders. The status of pretreatment immune function was important in predicting the response to interferon treatment. The implication of these findings with respect to understanding the mechanism of action of interferon and the definition of the most appropriate patients for interferon treatment are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Recombinant human granulocyte-macrophage colony-stimulating factor stimulates in vitro mature human neutrophil and eosinophil function, surface receptor expression, and survival.

A purified recombinant human granulocyte-macrophage colony stimulating factor (rH GM-CSF) was a powerful stimulator of mature human eosinophils and neutrophils. The purified rH GM-CSF enhanced the cytotoxic activity of neutrophils and eosinophils against antibody-coated targets, stimulated phagocytosis of serum-opsonized yeast by both cell types in a dose-dependent manner, and stimulated neutrophil-mediated iodination in the presence of zymosan. In addition, rH GM-CSF enhanced N-formylmethionylleucylphenylalanine(FMLP)-stimulated degranulation of Cytochalasin B pretreated neutrophils and FMLP-stimulated superoxide production. In contrast, rH GM-CSF did not promote adherence of granulocytes to endothelial cells or plastic surfaces. rH GM-CSF selectively enhanced the surface expression of granulocyte functional antigens 1 and 2, and the Mo1 antigen. rH GM-CSF induced morphological changes and enhanced the survival of both neutrophils and eosinophils by 6 and 9 h, respectively. These experiments show that granulocyte-macrophage colony stimulating factor can selectively stimulate mature granulocyte function.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1986

Immunological variables as predictors of prognosis in patients with Kaposi's sarcoma and the acquired immunodeficiency syndrome.

Multivariate analysis was used to identify which of a large number of pretreatment immunological parameters correlated with therapeutic response, subsequent development of opportunistic infection, and survival from the time of diagnosis in a group of 70 patients with Kaposi's sarcoma and acquired immunodeficiency syndrome treated with recombinant leukocyte A interferon. In a logistic regression model, delayed type hypersensitivity response to one or more recall antigens and high proliferative response to Escherichia coli were significant predictors for response to recombinant leukocyte A interferon (for the model, P = 0.01). For prediction of the development of opportunistic infection, the model selected low proliferative responses to phytohemagglutinin and E. coli (P less than 0.001). Favorable factors predicting survival in the Cox regression model were the absence of endogenous serum interferon activity and a high proliferative response to E. coli (P less than 0.001). The estimated median survival for the group with endogenous serum interferon activity and low E. coli response was 12 months; the median has not yet been reached for the group with no serum interferon and a high E. coli response. We conclude that immunological parameters may be useful in predicting prognosis in patients with Kaposi's sarcoma and acquired immunodeficiency syndrome.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Long-term results of a pilot study for the treatment of advanced unresectable head and neck tumors by combination chemotherapy and split course radiotherapy.

The results of treatment of 30 patients with advanced unresectable squamous cell carcinoma of the head and neck (stage III and IV) are presented. These patients were treated in a pilot study using kinetically based combination chemotherapy and split course radiotherapy from July 1977 until December 1979. Twenty-three patients (76%) achieved a local response (53% complete and 23% partial) and the median survival was 16 months. The two-year survival was 43%. Although no significant increase in acute radiation morbidity was seen, 43% of the patients developed chronic symptomatic complications. Seven patients (23%) developed second primary cancers, of which five were bronchogenic carcinomas and two were esophageal carcinomas. The regimen adopted produced a high local control rate with permanent local control in 50% of patients treated, but this was achieved at the expense of a high chronic toxicity rate. The incidence of second primary malignancies, presumably because of on-going environmental factors, remains a continuing concern.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1986

Effects of recombinant GM-CSF on the blast cells of acute myeloblastic leukemia.

The effects of recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) were compared to those of media conditioned by the continuous bladder carcinoma line, HTB9 (HTB9-CM), using three criteria. First, both GM-CSF and HTB9-CM stimulated blast colony formation in methylcellulose cultures, patient-to-patient variations were seen in the dose-response curves, and GM-CSF was effective, but less so that HTB9-CM. Second, GM-CSF also enhanced growth of blast progenitors in suspension culture, indicating its capacity to support self-renewal. GM-CSF was as effective as HTB9-CM in the production of adherent cells during the growth of blast cells in suspension, a finding that is interpreted to mean that GM-CSF also supports postdeterministic events in blast differentiation. Finally, colonies growing in the presence of GM-CSF were not phenotypically different than those stimulated by HTB9-CM.

Cells, Cultured↗
PubMed1986

Detection of activated Mr 21,000 protein, the product of ras oncogenes, using antibodies with specificity for amino acid 12.

Antisera raised to a set of chemically synthesized peptides spanning position 12 of ras Mr 21,000 protein (p21) (residues 5 to 17) were able to distinguish between different forms of p21 according to the amino acid at the twelfth codon. The peptide immunogens differed in one amino acid corresponding to position 12 of the protein; the substitutions were valine, serine, arginine, aspartate, alanine, or cysteine at this position. Normal p21 contains glycine at position 12; the other amino acid substitutions are those which would result from a single base change in codon 12 and may therefore be the activating mutations most likely to occur in human tumors. The peptide antisera were evaluated by the Western immunoblot procedure for reactivity with v-ki-ras p21 expressed in Escherichia coli containing the corresponding position 12 mutations. Five of the antisera reacted with p21, and of these, anti-serine, -valine, -arginine, and -aspartate peptide antibodies were specific for their cognate protein. Similar analysis using mammalian cells as sources of position 12 variant forms of p21 demonstrated the ability of these antisera to distinguish among their oncogenic forms of p21 differing by single amino acid substitutions.

Amino Acids↗
PubMed1986

Predictive model for prognosis in advanced diffuse histiocytic lymphoma.

The purpose of this study was to examine the validity of a predictive model for response to treatment and survival in advanced diffuse histiocytic lymphoma. One hundred twenty-seven consecutive patients with Ann Arbor stage II-IV diffuse histiocytic lymphoma, who completed treatment between 1974 and 1984 in one of four different Memorial Hospital combination chemotherapy protocols, were reviewed. The median follow-up time was 66.9 months for survivors (range, 21-153.1 months). Factors studied included: age; sex; Ann Arbor stage; prior therapy; B symptoms; serum lactic dehydrogenase (LDH); sites of initial disease; and tumor bulk. LDH was grouped accordingly (units/liter): low, less than 225; medium, 225-500; high, greater than 500. Each patient was assigned an overall level of site involvement (LSI) from the following mutually exclusive groups: group I, peripheral lymph node (PLN) (including +/- Waldeyer ring involvement, +/- spleen); group II, extranodal disease (EN) +/- PLN; group III, retroperitoneal lymph node (RLN) +/- PLN; group IV, bulky mediastinal disease (MED) +/- any other disease; group V, EN with RLN +/- PLN. The Ann Arbor staging system failed to dissect patient groups differing significantly in their prognosis. Serum LDH, LSI, and age were the only factors important for predicting response and survival after multivariate logistic regression and a parametric Weibull survival analysis. Using three levels of serum LDH and correlating them with the different LSI, four tentative "stages" differing significantly in their survival at 48 months were defined: stage I, low LDH, any LSI (80% alive); stage II, medium LDH, PLN, and/or EN (50% alive); stage III, high LDH, PLN, and/or EN or medium LDH, RLN +/- PLN +/- EN, and/or MED (35% alive); stage IV, high LDH, RLN +/- PLN +/- EN, and/or MED (15% alive). Identification of prognostic stages on the basis of LDH level and LSI will allow more accurate comparison of clinical trials for patients with advanced diffuse histiocytic lymphoma.

Adult↗
PubMed1986

Modeling the supply of nurse labor. Life-cycle activity patterns of registered nurses in one Canadian delivery system.

Using 1980 membership data made available by the provincial nurses' association, a simple, age-specific projection model was developed that comprised two submodels: a Markovian one to monitor yearly movements from one membership state to another and a linear submodel for the infusion of new members. The model assumes that the likelihood of moving to any membership state depends only on the nurse's current age and membership state. A comparison of actual/projected data for 1981-1984 indicates a fairly high level of accuracy, despite the oscillatory pattern of the nurse labor market in the Province of British Columbia since 1982. The details of the projections of labor force over time show a particular age cohort's characteristic behavior and delineate the effect of childbearing and aging on the supply of nurses. As well as projecting future manpower, the age-specific transition matrices were used to estimate the professional life expectancy of registered nurses. This information includes the average number of continuous years of practice for each age, as well as the average total number of years of practice until being deleted from the system at the age of 75. The forecasting capability developed from this work attempts to address two questions central to manpower planning: how many nurses will there be in the province in the next 5 years? and what is the time-frame involved in nurses' life-cycle activity patterns?

Age Factors↗