Telomere Length and Preterm Birth in Pregnant Mexican-Origin Women

Objectives

Despite the obstacles of limited education and employment opportunities—and the stress associated with immigration and pregnancy—Mexican immigrant women have low rates of preterm birth (PTB) compared to the US national average for all races and ethnicities. Stressors during pregnancy, and stressors associated with acculturation, may accelerate cellular aging manifested by shortened telomere length (TL) in pregnant women. Our objectives were to: (1) determine whether women with PTBs had shorter telomere lengths compared to women who had full term births; (2) assess the association of acculturation with TL and PTB.

Methods

This prospective pilot study collected data from 100 self-identified Mexican-origin pregnant women. Survey data included self-administered sociodemographic and acculturation measures and was collected from participants via paper and pen, while biologic data was collected via a single blood draw during a regularly scheduled prenatal visit between 26 and 36 weeks gestation. PTB data was collected from the participant’s medical record after delivery.

Results

TL was significantly associated with PTB; the median TL of the women with PTB was less than the median TL for the full sample (p?=?0.02). Based on regression analysis for PTB vs acculturation, we found no significant associations between acculturation and PTB or TL.

Conclusions for Practice

This study provides important evidence of the association between shortened maternal TL and adverse birth outcomes. By linking social, clinical and biologic data, we can enhance our understanding of social determinants that may affect racial and ethnic disparities in preterm birth.

     

Use of pluronic micelles to overcome multidrug-resistance

Pluronic P-85 (poly(55)(oxypropylene)dipoly(s)(oxyethylene)) was used to form daunorubicin containing micelles. This new carrier was tested in vitro on sensitive and resistant ovarian cancer cell lines. Drug incorporation was measured by cytofluorometry and the cytotoxicity was measured by the tetrazolium formazan XTT assay. ID50 of 0.16 and 25 mu g/ml were obtained for conjugated and free daunorubicin respectively. The results obtained suggest that this approach may be used in combination with a chemotherapeutic agent to overcome multidrug resistance.     

Genetic analysis of three patients with an 18p- syndrome and dystonia

Some patients with an 18p- syndrome show dystonia, and a focal dystonia gene has been mapped to chromosome 18p. The authors evaluated the extent of the deletion in three patients with an 18p- syndrome and dystonia using 14 DNA markers on 18p. A common deleted area, covering the DYT7 locus, places the putative dystonia gene between the telomere of 18p and D18S1104 (49.6 cM). Dystonia in these patients may be caused by haploinsufficiency of the DYT7 gene, a new dystonia gene on 18p, or may result from developmental brain anomalies.     

Serotonergic mediation of the effects of fluoxetine, but not desipramine, in the rat forced swimming test

Rationale: The forced swimming test (FST) is a behavioral test in rodents that predicts the clinical efficacy of many types of antidepressant treatments. Recently, a behavior sampling technique was developed that scores individual response categories, including swimming, climbing and immobility. Although all antidepressant drugs reduce immobility in the FST, at least two distinct active behavioral patterns are produced by pharmacologically selective antidepressant drugs. Serotonin-selective reuptake inhibitors increase swimming behavior, while drugs acting primarily to increase extracellular levels of norepinephrine or dopamine increase climbing behavior. Distinct patterns of active behaviors in the FST may be mediated by distinct neurotransmitters, but this has not been shown directly. Objectives: The present study examined the role of serotonin in mediating active behaviors in the forced swimming test after treatment with two antidepressant drugs, the selective serotonin reuptake inhibitor, fluoxetine and the selective norepinephrine reuptake inhibitor, desipramine. Methods: Endogenous serotonin was depleted by administering para-cholorophenylalanine (PCPA, 150 mg/kg, IP.) to rats 72 h and 48 h prior to the swim test. Fluoxetine (10 mg/kg, SC) or desipramine (10 mg/kg, SC) was given three times over a 24-h period prior to the FST. Behavioral responses, including immobility, swimming and climbing, were counted during the 5-min test. Results: Pretreatment with PCPA blocked fluoxetine-induced reduction in immobility and increase in swimming behavior during the FST. In contrast, PCPA pretreatment did not interfere with the ability of desipramine to reduce immobility and increase climbing behavior. Conclusions: Depletion of serotonin prevented the behavioral effects of the selective serotonin reuptake inhibitor fluoxetine in the rat FST. Furthermore, depletion of serotonin had no impact on the behavioral effects induced by the selective norepinephrine reuptake inhibitor, desipramine. The effects of antidepressant drugs on FST-induced immobility may be exerted by distinguishable contributions from different neurotransmitter systems. Received: 4 February 1999 / Final version: 2 June 1999     

Recent advances in our understanding of the use of theophylline in the treatment of asthma

The use of theophylline for the treatment of asthma for 45 of the past 50 years has been for its ability to dilate bronchi. The problem has been that at the most effective bronchodilating dose, toxicity was too close for comfort. In the past 5 years, there has been resurgence in theophylline use at lower doses because of some well-documented anti-inflammatory and steroid sparing effects.