Side population/ABCG2-positive cells represent a heterogeneous group of haemopoietic cells: implications for the use of adult stem cells in transplantation and plasticity protocols.

Murine side population (SP) cells may have an increased ability to engraft lethally irradiated mice and lack CD34 expression. Strategies using CD34 as a primary marker of haemopoietic stem cells may therefore result in the exclusion of a primitive stem cell population. The molecular basis for the murine SP phenotype has been attributed to the multidrug-resistance transporter ABCG2. This study aimed to investigate ABCG2 expression from a variety of human sources and investigate the relationship between ABCG2 expression, the SP phenotype, and expression of markers such as CD34 and CD133. SP cells were observed in different haemopoietic sources, but a significant increase in the number of SP cells was observed in PB following granulocyte colony-stimulating factor mobilisation. No direct correlation between the frequency of SP cells and the expression of ABCG2 was observed. SP cells were identified in both lineage-positive and lineage-negative population and ABCG2 expression was enriched in lineage-negative SP cells. Lineage-negative SP cells were devoid of CD34 expression but enriched for CD133. Subsequent analysis revealed that ABCG2 and CD133 are coexpressed. Together, these data suggest that the ABCG2 transporter is neither required nor responsible for the SP phenotpye in many human blood cells.

Premature rupture of the membranes: an evidence-based approach to clinical care.

Management of the patient with premature rupture of membranes is a relatively common but often perplexing problem frequently faced by the obstetrician. Despite the recent advances in perinatal care, premature membrane rupture, especially in the preterm patient, remains a potentially serious complication with important maternal and fetal implications. This review will address the important questions concerning the management of premature rupture of membranes and will attempt to provide comprehensive answers as they appear in the medical literature.

Trisomy 21. Second-trimester ultrasound.

Not every aspect of sonographic examination reveals karyotypic abnormalities. Ultrasound examination of a fetus with trisomy 21 generally reveals normal amniotic fluid, normal placentation, and normal fetal growth. In addition, other chromosomal abnormalities have many of the same sonographic findings as Down syndrome, and many findings have a large overlap with phenotypically normal fetuses. The importance of second-trimester ultrasound screening for Down syndrome has remained great because of its ease of use and relative effectiveness. Trained sonographers can adjust the relative risk for trisomy 21 and alter the need for genetic amniocentesis. It is important that parents understand the limitations of a screening test and the risks and benefits of possible subsequent confirmatory testing. If a major structural abnormality is identified on ultrasound, karyotype determination should be considered. Nuchal thickness in the first or second trimester remains the most clinically useful marker for trisomy 21. The predictive value of all the markers depends on the population studied and can be modified by a host of biochemical markers and historical factors. If fetal karyotype analysis could be performed without sampling through the uterus, prenatal diagnosis could be offered to all pregnant women, and screening would be unnecessary. Despite its limitations, ultrasound will have an important role in prenatal diagnosis at least until isolating and testing fetal cells from maternal blood or other sources becomes practical and widely available. Whether used alone or in conjunction with additional biochemical or molecular serum markers, ultrasound is an important and powerful tool in prenatal genetic evaluation.

Trisomy 13 in one fetus from a twin gestation after intracytoplasmic sperm injection. A case report.

BACKGROUND: Intracytoplasmic sperm injection (ICSI) is an assisted reproductive technique used in the treatment of severe male factor infertility. Reports of chromosomal aberrations in some fetuses conceived following ICSI have raised concern that the technique may contribute to the development of genetic disease. CASE: Trisomy 13 occurred in one of twin fetuses of a 28-year-old woman who underwent ICSI. This case is unique because it is the first reported one of an autosomal trisomy complicating one fetus from a twin gestation conceived by ICSI. It is also the first case describing an autosomal trisomy following ICSI in a woman under the age of 35. CONCLUSION: Chromosomal abnormalities associated with ICSI may be accounted for by factors other than advanced maternal age. Chromosomal aberrations may be related to the procedure itself. Therefore, patients should be advised of the possibility of aneuploidy in association with ICSI, and genetic amniocentesis should be considered regardless of maternal age.

Pregnancy outcome in Hispanic patients with unexplained positive triple marker screening for Down syndrome.

OBJECTIVE: The objective of this study was to compare pregnancy outcomes in Hispanic patients with a positive serum triple marker screen for Down syndrome and normal fetal karyotype with Hispanic women who had a negative triple marker screen. METHODS: This prospective investigation involved Hispanic gravidas who underwent maternal serum screening. A power analysis was performed to determine the sample size. Fifty women with false-positive screens for Down syndrome were matched with a control group of 100 women with a negative screen. Adverse pregnancy outcomes were compared between the two groups. RESULTS: An adverse pregnancy outcome occurred in 14% of the study group and in 13% of controls. There were no statistically significant differences between the two groups in the incidence of preterm labor (p > 0.5), pre-eclampsia (p > 0.1), intrauterine growth restriction (p > 0.5), or fetal demise (p > 0.5). CONCLUSION: Hispanic patients with unexplained positive triple marker screen for Down syndrome do not appear to be at increased risk for adverse pregnancy outcomes.

Cefotetan-induced hemolysis associated with antibiotic prophylaxis for cesarean delivery.

We describe 3 cases of antibiotic-induced hemolysis associated with cefotetan prophylaxis during cesarean delivery. Each of the 3 patients showed development of significant anemia with documented cefotetan-induced hemolysis. When postpartum anemia is associated with antibiotic use, immune hemolytic anemia should be considered and included in the differential diagnosis.

Effects of behavioral and pharmacological weight loss programs on nutrient intake.

Behavior therapy is a widely used method for short-term weight control. Formal nutrition counseling is not included in many behavioral programs. To determine what types of diets were self-selected by patients and to see how they compared with individuals participating in a relaxation group with anorectic medication, the eating diaries compiled by participants in such a program were analyzed for 20 different nutrients. In general, pretreatment intakes were nutritious and typical for Americans. Both the behavioral and a relaxation-medication treatment produced weight loss and reduction in calorie intake. Both treatments were associated with the consumption of a fairly nutritious diet not much different from the pretreatment intake except for a reduction in the amount eaten.

Effects of a combined behavioral and pharmacological program on weight loss.

The effects of an 'anorectic' drugs as an adjunct to a behavioral weight-loss programme were investigated. Four groups of 20 began an initial two weeks of instruction. Groups 1, 2, and 3 were instructed in a behavioral programme utilizing a food diary, stimulus control techniques, and reinforcement. Group 4 was instructed in a relaxation programme. Group 1 took phentermine resin 30 mg for eight weeks, followed by a placebo for eight. Group 2 took placebo for eight and phentermine for eight. Group 3 took placebo for 16. Group 4 took placebo for eight and phentermine for eight. All groups were followed for an additional eight weeks. A significant number of subjects in all behavioral groups achieved some weight loss. (A significant difference among the mean percentage body weight reduction for the three behavioral groups was also found.) In addition, a group of 'slow losers' who initially lost less than one half-pound (0.2 kg) per week and were subsequently placed on phentermine lost significantly more weight than a similar group which continued on placebo. These differences were maintained for 24 weeks.