Sex hormones, sex hormone binding globulin, and abdominal aortic calcification in women and men in the multi-ethnic study of atherosclerosis (MESA)

Background

Conflicting findings exist regarding the associations of sex hormones with subclinical atherosclerosis.

Methods

This is a substudy from MESA of 881 postmenopausal women and 978 men who had both abdominal aortic calcification (AAC) quantified by computed tomography and sex hormone levels assessed [Testosterone (T), estradiol (E2), dehydroepiandrosterone (DHEA), and sex hormone binding globulin (SHBG)]. We examined the association of sex hormones with presence and extent of AAC.

Results

For women, SHBG was inversely associated with both AAC presence [OR = 0.62, 95% CI 0.42-0.91 for 1 unit greater log(SHBG) level] and extent [0.29 lower log(AAC) for 1 unit greater log(SHBG) level, β = −0.29 (95% CI −0.57 to −0.006)] adjusting for age, race, hypertension, smoking, diabetes, BMI, physical activity, and other sex hormones. After further adjustment for total and HDL-cholesterol, SHBG was not associated with ACC presence or extent. In men, there was no association between SHBG and AAC. In both men and women, neither T, E2, nor DHEA was associated with AAC presence or extent.

Conclusion

After adjustment for non-lipid cardiovascular risk factors, SHBG levels are inversely associated with both the presence and severity of AAC in women but not in men, which may be accounted for by HDL.     

Evidence-based use of statins for primary prevention of cardiovascular disease

Three-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, commonly known as statins, are widely available, inexpensive, and represent a potent therapy for treating elevated cholesterol. Current national guidelines put forth by the Adult Treatment Panel III recommend statins as part of a comprehensive primary prevention strategy for patients with elevated low-density lipoprotein cholesterol at increased risk for developing coronary heart disease within 10 years. Lack of a clear-cut mortality benefit in primary prevention has caused some to question the use of statins for patients without known coronary heart disease. On review of the literature, we conclude that current data support only a modest mortality benefit for statin primary prevention when assessed in the short term (<5 years). Of note, statin primary prevention results in a significant decrease in cardiovascular morbidity over the short and long term and a trend toward increased reduction in mortality over the long term. When appraised together, these data provide compelling evidence to support the use of statins for primary prevention in patients with risk factors for developing coronary heart disease over the next 10 years.     

Liver-derived fetal hematopoietic stem cells selectively and preferentially home to the fetal bone marrow

In the course of ontogeny, the homing site for the hematopoietic stem cells (HSC) moves with certain predictability from the yolk sac to the liver/spleen and then to the marrow. The pattern of this migration has thus far been established mostly on a morphologic basis. To delineate further the course of this migration and to gain insight into its possible mechanism, we used in utero transplantation of allogeneic or xenogeneic HSC in preimmune sheep fetuses. Sex chromosome, type of hemoglobin, and species-specific surface markers were used to follow the path of transplanted cells in the fetus. Before the development of the bone marrow, transplanted HSC (liver- or marrow-derived) homed exclusively to the liver/spleen. With the development of marrow, around day 60 of gestation (term, 145 days), homing occurred also in the nascent marrow and by day 80 transplanted cells homed exclusively to the marrow. This suggests that there may be a hierarchy in homing sites, with those of the marrow having higher affinity than those of liver/spleen. Interestingly, despite a change in homing that was followed by the expansion of the marrow compartment of HSC (ie, HSC proliferation), these cells did not participate actively in blood cell formation during most of the prenatal period. Liver remained the major hematopoietic organ throughout the gestation. It was only during the perinatal period that this organ assumed the function of hematopoiesis from the liver. This lack of expression of HSC in fetal marrow can possibly be attributable to the immaturity of marrow stroma required for differentiation and maturation of progenitors and the orderly egress of mature cells into the blood stream. The availability of this model allows us to begin studies in the molecular mechanism of stem cell homing in vivo during ontogeny.     

A novel 37-Kd adhesive membrane protein from cloned murine bone marrow stromal cells and cloned murine hematopoietic progenitor cells

The adhesion of hematopoietic progenitor cells to bone marrow stromal cells is critical to hematopoiesis and involves multiple effector molecules. Stromal cell molecules that participate in this interaction were sought by analyzing the detergent-soluble membrane proteins of GBI/6 stromal cells that could be adsorbed by intact FDCP-1 progenitor cells. A single-chain protein from GBI/6 cells having an apparent molecular weight of 37 Kd was selectively adsorbed by FDCP-1 cells. This protein, designated p37, could be surface-radiolabeled and thus appeared to be exposed on the cell membrane. An apparently identical 37- Kd protein was expressed by three stromal cell lines, by Swiss 3T3 fibroblastic cells, and by FDCP-1 and FDCP-2 progenitor cells. p37 was selectively adsorbed from membrane lysates by a variety of murine hematopoietic cells, including erythrocytes, but not by human erythrocytes. Binding of p37 to cells was calcium-dependent, and was not affected by inhibitors of the hematopoietic homing receptor or the cell-binding or heparin-binding functions of fibronectin. It is proposed that p37 may be a novel adhesive molecule expressed on the surface of a variety of hematopoietic cells that could participate in both homotypic and heterotypic interactions of stromal and progenitor cells.     

CD34+ human marrow cells that express low levels of Kit protein are enriched for long-term marrow-engrafting cells

Using in utero transplantation into fetal sheep, we examined the capability of human bone marrow CD34+ cells fractionated based on Kit protein expression to provide long-term in vivo engraftment. Twelve hundred to 5,000 CD34+ Kit-, CD34+ Kit(low), and CD34+ Kit(high) cells were injected into a total of 14 preimmune fetal sheep recipients using the amniotic bubble technique. Six fetuses were killed in utero 1.5 months after bone marrow cell transplantation. Two fetuses receiving CD34+ Kit(low) cells showed signs of engraftment according to analysis of CD45+ cells in their bone marrow cells and karyotype studies of the colonies grown in methylcellulose culture. In contrast, two fetuses receiving CD34+ Kit(high) cells and two fetuses receiving CD34+ Kit- cells failed to show evidence of significant engraftment. Two fetuses were absorbed. A total of six fetuses receiving different cell populations were allowed to proceed to term, and the newborn sheep were serially examined for the presence of chimerism. Again, only the two sheep receiving CD34+ Kit(low) cells exhibited signs of engraftment upon serial examination. Earlier in studies of murine hematopoiesis, we have shown stage-specific changes in Kit expression by the progenitors. The studies of human cells reported here are in agreement with observations in mice, and indicate that human hematopoietic stem cells are enriched in the Kit(low) population.     

Clinical experience and results of treatment with suprofen in pediatrics. 5th communication: a single-blind study on antipyretic effect and tolerability of suprofen syrup versus metamizole drops in pediatric patients

In a single-blind study, 60 children in two age groups (30 patients: 6 months to 3 years; 30 patients: 3 years to 12 years), were orally treated with either alpha-methyl-4-(2-thienyl-carbonyl)phenylacetic acid (suprofen, Suprol), syrup 10 mg/ml or metamizole drops 50% for a maximum period of 4 days, up to 4 times a day. The children presented with high fever due to bacterial or virus infections. Body temperature, pulse rate, and respiratory rate were evaluated at the beginning and then 30 min, 1, 1 1/2, 2, 3, 4, 5, and 6 h after the first administration of the respective drug. Significant differences between the drugs were found for all variables; this demonstrated that with suprofen the antipyretic effect set in more rapidly than with the reference drug. No side-effects were observed in children treated with suprofen syrup. Two patients showed adverse effects, i.e. sweating and hypotension, during the treatment with metamizole. Due to its good antipyretic effect and good tolerability, suprofen appears to be particularly useful for symptomatic treatment of pediatric patients with fever caused by bacterial or virus infections.     

垂全催乳素瘤的诊断和治疗指南

3.男性:高催乳素血症通常导致阳痿、不孕和性功能低下.男性患者通常为大腺瘤,有神经系统症状.其原因可能是对症状认识的延误或者肿瘤生物学行为的差异.