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71.
ERJ Giugliani RMS Issler EB Justo CF Seffrin RM Hartmann NM Carvalho 《Acta paediatrica (Oslo, Norway : 1992)》1992,81(6-7):484-487
A prospective study was undertaken to identify possible factors related to the duration of breast feeding. Two hundred and thirty-eight mothers who had delivered normal single babies with birth weights greater than 2.5 kg and had initiated breast feeding were randomly selected at the maternity hospital, Hospital de Clinicas de Porto Alegre, Brazil, and followed by mail questionnaires until termination of breast feeding, or until the end of the first year. If no reply was received, telephone contact or home visits were made. The group of mothers who stopped breast feeding prior to the end of the third month was compared with those who extended breast feeding beyond three months with respect to socioeconomic, biological, environmental, medical and psychological factors. The variables with a significant coefficient of association with early termination of breast feeding were maternal education, past experience with breast feeding, help of a maid, help with housework provided by a relative, breast feeding orientation during prenatal care and encouragement from the husband. These factors act simultaneously, with interactions among them. 相似文献
72.
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74.
DRA Mans AE Budhu Lall VL Macnack JA van Tholl EB Zandveld MA Vrede 《The West Indian medical journal》2014,63(2):121-127
Objective:
We report on the incidence and the gender, age and ethnic distribution of sarcomas diagnosed between 1980 and 2008 in the multi-ethnic Republic of Suriname.Methods:
Total and average yearly number of cases, crude rates, as well as relevant population data were derived from the records of the Pathologic Anatomy Laboratory and the General Bureau of Statistics, respectively, and stratified according to gender, age groups 0–19, 20–49 and 50+ years, and the largest ethnic groups (Hindustani, Creole, Javanese and Maroons).Results:
Between 1980 and 2008, 258 sarcomas were diagnosed in Suriname, ie at a frequency of nine per year and an annual rate of two per 100 000. Overall, there was 0.9 male per female, two to four cases per year in each age group, and one to three patients in each ethnic group. Soft-tissue sarcomas comprised approximately 80% of overall cases, with a male/female ratio that was approximately 0.5; almost 90% of patients were older than 20 years; more than one-third was Creole. Leiomyosarcoma, fibrosarcoma and liposarcoma were most frequently encountered (90 cases), particularly above 20 years of age, while leiomyosarcomas seemed, additionally, more common in women and Creoles or Maroons. The most numerous bone tumours were primitive neuroectodermal tumour/Ewing tumour and osteosarcoma (37 cases). They were more common in males, the youngest age group, and Hindustanis and Creoles.Conclusions:
The incidence of sarcomas in Suriname, and their gender, age and ethnic distribution in general, seemed comparable with international data. The main exception might be leiomyosarcoma which might have a predilection for Afro-Surinamese. 相似文献75.
76.
Previous studies have shown that retinoic acid (RA), similar to tumor necrosis factor-alpha (TNF-alpha), can act as a bifunctional regulator of the growth of bone marrow progenitors, in that it can stimulate granulocyte-macrophage colony-stimulating factor (GM-CSF)- or interleukin-3 (IL-3)-induced GM colony formation, but potently inhibit G-CSF-induced growth. The present study, using highly enriched human CD34+ as well as Lin- murine bone marrow progenitor cells, demonstrates a potent inhibitory effect of 9-cis-RA on burst-forming unit-erythroid (BFU-E) colony formation regardless of the cytokine stimulating growth. Specifically, 9-cis-RA potently inhibited the growth of BFU-E response to erythropoietin (Epo) (100%), stem cell factor (SCF) + Epo (92%), IL- 3 + Epo (97%), IL-4 + Epo (88%), and IL-9 + Epo (100%). Erythroid colony growth was also inhibited when CD34+ progenitors were seeded at one cell per well, suggesting a direct action of RA. Using synthetic ligands to retinoic acid receptors (RARs) and retinoid X receptors (RXRs) that selectively bind and activate RAR-RXR or RXR-RXR dimers, respectively, we dissected the involvement of the two retinoid response pathways in the regulation of normal myeloid and erythroid progenitor cell growth. Transactivation studies showed that both the RAR (Ro 13- 7410) and RXR (Ro 25-6603 and Ro 25-7386) ligands were highly selective at 100 nmol/L. At this concentration, Ro 13-7410 potently inhibited G- CSF-stimulated myeloid as well as SCF + Epo-induced erythroid colony growth. At the same concentration, Ro 25-6603 and Ro 25-7386 had little or no effect on G-CSF-induced colony formation, whereas they inhibited 75% and 53%, respectively, of SCF + Epo-stimulated BFU-E colony growth. Thus, the RAR-RXR response pathway can signal growth inhibition of normal bone marrow myeloid and erythroid progenitor cells. In addition, we demonstrate a unique involvement of the RXR-RXR pathway in mediating growth inhibition of erythroid but not myeloid progenitor cells. 相似文献
77.
Human neutrophils are primed in the presence of complexes of lipopolysaccharide (LPS) with its serum binding protein (LBP) in a manner dependent on CD14. Cellular consequences of priming include increased responsiveness, the upregulation of surface proteins including the adhesive integrin CD11b/CD18 (Mac-1), the increased binding of certain ligands to CD11b/CD18, and the concurrent shedding of the L-selectin homing receptor. Because expression of both CD11b/CD18 and L-selectin is obligatory for formyl peptide-stimulated neutrophil aggregation in vitro (Simon et al, Blood 82:1097, 1993), we have examined the consequences of bacterial endotoxin on the expression of neutrophil adhesive molecules. We observed that the exposure of neutrophils to LPS/LBP, while enhancing the surface numbers and adhesive function of CD11b/CD18 for latex particles, did not induce aggregation. In contrast, as the LPS/LBP concentration increased (ED50 = 30 ng/mL LPS/LBP), the ability of neutrophils to aggregate decreased in parallel with the shedding of L-selectin. Moreover, when L-selectin adhesive activity was blocked by treatment with Fab fragments of Dreg- 200, aggregation was inhibited to an extent roughly proportional to the available L-selection. Blocking of LPS/LBP with CD14-specific monoclonal antibodies suppressed L-selectin shedding and preserved formyl peptide-stimulated aggregation. Taken together, the data suggest that inhibition of neutrophil aggregation by LPS/LBP is related to the expression of L-selectin via CD14 rather than LPS inhibition of CD11b/CD18 function during cellular stimulation. 相似文献
78.
Functional differences between CD38- and DR- subfractions of CD34+ bone marrow cells 总被引:1,自引:1,他引:1
Several studies have previously demonstrated enrichment in primitive progenitor cells in subfractions of CD34+ bone marrow (BM) cells not expressing CD38 or HLA-DR (DR) antigens. However, no studies have directly compared these two cell populations with regard to their content of primitive and more committed progenitor cells. Flow cytometric analysis of immunomagnetic isolated CD34+ cells demonstrated little overlap between CD34+CD38- and CD34+DR- progenitor subpopulations in that only 12% to 14% of total CD34+DR- and CD34+CD38- cells were double negative (CD34+CD38-DR-). Although the number of committed myeloid progenitor cells (colony-forming units granulocyte- macrophage) was reduced in both subpopulations, only CD34+CD38- cells were significantly depleted in committed erythroid progenitor cells (burst-forming units-erythroid). In single-cell assay, CD34+CD38- cells showed consistently poorer response to single as opposed to multiple hematopoietic growth factors as compared with unfractionated CD34+ cells, indicating that the CD34+CD38- subset is relatively enriched in primitive hematopoietic progenitor cells. Furthermore, CD34+CD38- and CD34+DR- cells, respectively, formed 3.2-fold and 1.6-fold more high proliferative potential colony-forming cell (HPP-CFC) colonies than did unfractionated CD34+ cells. Finally, CD34+CD38-DR- cells were depleted in HPP-CFCs as compared with CD34+CD38+DR+ cells. The results of the present study suggest that both the CD38- and DR- subfractions of CD34+ bone marrow cells are enriched in primitive hematopoietic progenitor cells, with the CD34+CD38- subpopulation being more highly enriched than CD34+DR- cells. 相似文献
79.
Rusten LS; Jacobsen FW; Lesslauer W; Loetscher H; Smeland EB; Jacobsen SE 《Blood》1994,83(11):3152-3159
Tumor necrosis factor alpha (TNF alpha) has previously been reported to have both inhibitory and stimulatory effects on hematopoietic progenitor cells. Specifically, TNF alpha has been proposed to stimulate early hematopoiesis in humans. In the present study we show that TNF alpha, in a dose-dependent fashion, can potently inhibit the growth of primitive high proliferative potential colony-forming cells (HPP-CFCs) stimulated by multiple cytokine combinations. Using agonistic antibodies to the p55 and p75 TNF receptors or TNF alpha mutants specific for either of the two TNF receptors, we show that both receptors can mediate this inhibition. In contrast, the potent stimulation of interleukin-3 (IL-3) plus granulocyte-macrophage colony- stimulating factor (GM-CSF) induced HPP-CFC colony formation observed at low concentrations of TNF alpha (2 ng/mL) was only a p55-mediated event. Moreover, the stimulatory effects of TNF alpha on GM-CSF or IL-3- induced colony formation, as well as the inhibition of G-CSF-induced colony growth, were also exclusively signaled through the p55 TNF receptor. Taken together, our results suggest that the inhibitory effects of TNF alpha on primitive bone marrow progenitor cells are mediated through both p55 and p75 TNF receptors, whereas the p55 receptor exclusively mediates the bidirectional effects on more mature, single factor-responsive bone marrow progenitor cells as well as stimulation of IL-3 plus GM-CSF-induced HPP-CFC colony growth. 相似文献
80.
Sokal JE; Cox EB; Baccarani M; Tura S; Gomez GA; Robertson JE; Tso CY; Braun TJ; Clarkson BD; Cervantes F 《Blood》1984,63(4):789-799
The prognostic significance of disease features recorded at the time of diagnosis was examined among 813 patients with Philadelphia chromosome- positive, nonblastic chronic granulocytic leukemia (CGL) collected from six European and American series. The survival pattern for this population was typical of "good-risk" patients, and median survival was 47 mo. There were multiple interrelationships among different disease features, which led to highly significant correlations with survival for some that had no primary prognostic significance, such as hematocrit. Multivariable regression analysis indicated that spleen size and the percentage of circulating blasts were the most important prognostic indicators. These features, and age, behaved as continuous variables with progressively unfavorable import at higher values. The platelet count did not influence survival significantly at values below 700 X 10(9)/liter but was increasingly unfavorable above this level. Basophils plus eosinophils over 15%, more than 5% marrow blasts, and karyotypic abnormalities in addition to the Ph1 were also significant unfavorable signs. The Cox model, generated with four variables representing percent blasts, spleen size, platelet count, and age, provided a useful representation of risk status in this population, with good fit between predicted and observed survival over more than a twofold survival range. A hazard function derived from half of the patient population successfully segregated the remainder into three groups with significantly different survival patterns. We conclude that it should be possible to identify a lower risk group of patients with a 2-yr survival of 90%, subsequent risk averaging somewhat less than 20%/yr and median survival of 5 yr, an intermediate group, and a high- risk group with a 2-yr survival of 65%, followed by a death rate of about 35%/yr and median survival of 2.5 yr. 相似文献