Assisted reproductive technology use and outcomes in childhood cancer survivors.

BACKGROUND: Treatment exposures for childhood cancer reduce ovarian reserve. However, the success of assisted reproductive technology (ART) among female survivors is not well established. METHODS: Five-year survivors of childhood cancer in the Childhood Cancer Survivor Study were linked to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System, which captures national ART outcomes. The authors assessed the live birth rate, the relative risk (RR) with 95% confidence intervals (95% CIs), and associations with treatment exposure using generalized estimating equations to account for multiple ovarian stimulations per individual. Siblings from a random sample of survivors were recruited to serve as a comparison group. RESULTS: Among 9885 female survivors, 137 (1.4%; median age at diagnosis, 10 years [range, 0-20 years]; median years of follow-up after age 18 years, 11 years [range, 2-11 years]) underwent 224 ovarian stimulations using autologous or donor eggs and/or gestational carriers (157 autologous ovarian stimulation cycles, 67 donor ovarian stimulation cycles). In siblings, 33 (1.4%) underwent 51 autologous or donor ovarian stimulations. Of those who used embryos from autologous eggs without using gestational carriers, 97 survivors underwent 155 stimulations, resulting in 49 live births, for a 31.6% chance of live birth per ovarian stimulation (vs. 38.3% for siblings; p = .39) and a 43.9% chance of live birth per transfer (vs. 50.0%; p = .33). Prior treatment with cranial radiation therapy (RR, 0.44; 95% CI, 0.20-0.97) and pelvic radiation therapy (RR, 0.33; 95% CI, 0.15-0.73) resulted in a reduced chance of live birth compared with siblings. The likelihood of live birth after ART treatment in survivors was not affected by alkylator exposure (cyclophosphamide-equivalent dose, ≥8000 mg/m2 vs. none; RR, 1.04; 95% CI, 0.52-2.05). CONCLUSIONS: Childhood cancer survivors are as likely to undergo treatment using ART as sibling controls. The success of ART treatment was not reduced after alkylator exposure. The results from the current study provide needed guidance on the use of ART in this population.

Highly variable recessive lethal or nearly lethal mutation rates during germ-line development of male Drosophila melanogaster.

Each cell of higher organism adults is derived from a fertilized egg through a series of divisions, during which mutations can occur. Both the rate and timing of mutations can have profound impacts on both the individual and the population, because mutations that occur at early cell divisions will affect more tissues and are more likely to be transferred to the next generation. Using large-scale multigeneration screening experiments for recessive lethal or nearly lethal mutations of Drosophila melanogaster and recently developed statistical analysis, we show for male D. melanogaster that (i) mutation rates (for recessive lethal or nearly lethal) are highly variable during germ cell development; (ii) first cell cleavage has the highest mutation rate, which drops substantially in the second cleavage or the next few cleavages; (iii) the intermediate stages, after a few cleavages to right before spermatogenesis, have at least an order of magnitude smaller mutation rate; and (iv) spermatogenesis also harbors a fairly high mutation rate. Because germ-line lineage shares some (early) cell divisions with somatic cell lineage, the first conclusion is readily extended to a somatic cell lineage. It is conceivable that the first conclusion is true for most (if not all) higher organisms, whereas the other three conclusions are widely applicable, although the extent may differ from species to species. Therefore, conclusions or analyses that are based on equal mutation rates during development should be taken with caution. Furthermore, the statistical approach developed can be adopted for studying other organisms, including the human germ-line or somatic mutational patterns.

Infertility, infertility treatment, and achievement of pregnancy in female survivors of childhood cancer: a report from the Childhood Cancer Survivor Study cohort.

BACKGROUND: Previous studies have shown decreased pregnancy rates and early menopause in female cancer survivors; however, infertility rates and reproductive interventions have not been studied. We investigated infertility and time to pregnancy in female childhood cancer survivors, and analysed treatment characteristics associated with infertility and subsequent pregnancy. METHODS: The Childhood Cancer Survivor Study (CCSS) is a cohort study including 5 year cancer survivors from 26 Canadian and US institutions who were younger than 21 years at the time of diagnosis between Jan 1, 1970, and Dec 31, 1986, and a sibling control group. We included women aged 18-39 years who had ever been sexually active. We gathered demographic, medical, and reproductive data via a baseline questionnaire, and quantified exposure to alkylating agents and radiation therapy. Self-reported infertility, medical treatment for infertility, time to first pregnancy in survivors and siblings, and the risk of infertility in survivors by demographic, disease, and treatment variables were analysed. FINDINGS: 3531 survivors and 1366 female sibling controls who enrolled between Nov 3, 1992, and April 4, 2004, were included. Compared with their siblings, survivors had an increased risk (relative risk [RR] 1·48 [95% CI 1·23-1·78]; p<0·0001) of clinical infertility (ie, >1 year of attempts at conception without success), which was most pronounced at early reproductive ages (RR 2·92 [95% CI 1·18-7·20], p=0·020, in participants ≤24 years; 1·61 [1·05-2·48], p=0·029, in those aged 25-29 years; and 1·37 [1·11-1·69], p=0·0035, in those aged 30-40 years). Despite being equally likely to seek treatment for infertility, survivors were less likely than were their siblings to be prescribed drugs for treatment of infertility (0·57 [95% CI 0·46-0·70], p<0·0001). Increasing doses of uterine radiation and alkylating agent chemotherapy were strongly associated with infertility. Although survivors had an increased time to pregnancy compared with their siblings (p=0·032), 292 (64%) of 455 participants with self-reported clinical infertility achieved a pregnancy. INTERPRETATION: A more comprehensive understanding of infertility after cancer is crucial for counselling and decision making about future conception attempts and fertility preservation. FUNDING: National Cancer Institute, American Lebanese Syrian Associated Charities, Swim Across America.

Use and Effectiveness of Gonadotropin-Releasing Hormone Agonists for Prophylactic Menstrual Suppression in Postmenarchal Women Who Undergo Hematopoietic Cell Transplantation.

STUDY OBJECTIVE: To describe the rates of use and effectiveness of gonadotropin-releasing hormone (GnRH) agonists and other forms of hormonal menstrual suppression in prevention of vaginal bleeding among young women who underwent hematopoietic stem cell transplantation (HCT). DESIGN: Retrospective descriptive study. SETTING: University-based pediatric HCT practice. PARTICIPANTS: Fifty-five postmenarchal women who underwent HCT between 2004 and 2011. INTERVENTIONS: Administration of GnRH agonists or other forms of hormonal menstrual suppression. MAIN OUTCOME MEASURES: Rates of use of GnRH agonists and other forms of hormonal menstrual suppression, and rates and descriptions of vaginal bleeding. RESULTS: Forty-six of the 55 patients had experienced regular or irregular vaginal bleeding before HCT and were considered to be at risk for thrombocytopenia-associated menorrhagia. Forty of the 46 (87%) received hormonal menstrual suppression. Thirty-three patients were treated with a GnRH agonist, 4 with combined hormonal contraceptive pills, 1 with a combined hormonal contraceptive patch, 1 with depot medroxyprogesterone, and 1 with oral norethindrone. Twenty-nine of the 33 patients (88%) who received a GnRH agonist had complete amenorrhea during HCT and 4 of 33 (12%) experienced some degree of vaginal bleeding. CONCLUSION: GnRH agonists appear effective in prevention of vaginal bleeding complications in most postmenarchal women who underwent HCT. Some patients who might benefit do not receive a GnRH agonist and multiple barriers exist in identification and treatment of them.

Genetic variation by birth cohorts in Mexican Americans of Starr County, Texas.

Mexican Americans residing in Starr County, Texas, were grouped by their year of birth (1896-1925, 1926-1955, and 1956-1985) to determine the extent of birth cohort-related genetic variation within this population and the genetic differences, if any, from the Mexican population residing in the Metropolitan Monterrey Area (MMA), Nuevo León, México. Twenty-one genetic markers were analyzed which indicate that the three birth cohort groups are genetically indistinguishable. Gene diversity analysis suggests that more than 99.8% of the total gene diversity can be attributed to variation between individuals within the birth cohort populations and that the subdivision by birth cohort has only a small contribution (0.18%) to the total gene diversity. Genetic admixture analysis indicates a predominant influence from the Spanish, and that the three birth cohort groups were similar in terms of contributions of this ancestral population. The genetic structure of the Mexican American population of Starr County was also similar to the Mexican population from the State of Nuevo León, México. These findings, together with previous results, suggest that the Mexican Americans of Starr County, Texas, classified by gender, birthplace, and age, are not genetically distinguishable and are similar to the Mexican populations of the State of Nuevo León. © 1994 Wiley-Liss, Inc.

Facial clefting and Amerindian admixture in populations of Santiago, Chile.

Among congenital malformations, cleft lip with and/or without cleft palate has the highest relative frequencies and shows ethnic variation in prevalence. Both malformations are generally more common among the Asian than European populations. Many populations of Chile have genes of Amerindian and Spanish ancestry, with considerable variation in the degree of Amerindian admixture. Therefore, the association of clefting incidence with Amerindian admixture was investigated. The frequency of cleft lip and/or cleft palate in infants born in three private and two public maternity service clinics of Santiago, Chile, is reported. The private clinic patients have a higher socioeconomic status (SES) than those receiving the public services. They also differ in estimated Amerindian admixture. More than 200,900 consecutive birth records were reviewed. The rate of clefting malformations is 15.3 per 10,000 live births. Based on allele frequencies at the ABO and Rh blood group loci, the percentage of Amerindian admixture is higher in infants born in the public compared to those born in the private maternity service clinics. Amerindian admixture is positively correlated (Spearman's p = 0.9, P = 0.008) with clefting rate across these samples. Clefting is also associated with SES, with lower SES showing higher clefting rates. Mothers of clefting newborns also have higher estimated Amerindian admixture compared to those of normal newborns. The results support the view that in Chilean populations, susceptibility to clefting is related to Amerindian ancestry. Am. J. Hum. Biol. 9:225-232, 1997. © 1997 Wiley-Liss, Inc.

Obesity and upper body fat distribution in Mexican American children from families with a diabetic proband.

Upper and centralized body fat distribution is associated with non-insulin dependent diabetes mellitus (NIDDM). Few studies have focused on anthropometric characteristics of preadults from families in which there is a diabetic (NIDDM) proband. This study explores the prevalence of upper and centralized body fatness in Mexican American children from the Diabetes Alert study (1981-1983) in Starr County, Texas. Anthropometric data on 165 males and 224 females 9-19 years include measures of adiposity such as skinfold thicknesses and the body mass index (BMI), a measure of overweight. They show rates of obesity two to three times that of White children of comparable age and sex from National Health Surveys. In comparison with U.S. White subjects, Mexican American adults are shorter, have more adiposity and arm muscle mass and have sitting heights and body breadths at the mean of these dimensions for the U.S. POPULATION: Children from Diabetes Alert families show only marginal excess of severe obesity (> 95th percentile of BMI) when compared to the general population of children surveyed in Starr County schools. Girls from these families, but not boys, have excess fatness in the BMI compared to Mexican American children from the Hispanic Health and Nutrition Examination Survey (HHANES); suprailiac skinfold thicknesses are also greater in children of the Diabetes Alert study than in HHANES children. From 1972 through 1982, Mexican American children in South Texas showed an increase in average stature, weight, and the BMI. These data together suggest that excessive obesity exists and may be increasing in children in populations at risk for NIDDM. The prevention of NIDDM in the Mexican American population may be more effective if educational and promotional interventions include the school aged population. © 1993 Wiley-Liss, Inc.

Pattern of mutation rates in the germline of Drosophila melanogaster males from a large-scale mutation screening experiment.

The sperm or eggs of sexual organisms go through a series of cell divisions from the fertilized egg; mutations can occur at each division. Mutations in the lineage of cells leading to the sperm or eggs are of particular importance because many such mutations may be shared by somatic tissues and also may be inherited, thus having a lasting consequence. For decades, little has been known about the pattern of the mutation rates along the germline development. Recently it was shown from a small portion of data that resulted from a large-scale mutation screening experiment that the rates of recessive lethal or nearly lethal mutations differ dramatically during the germline development of Drosophila melanogaster males. In this paper the full data set from the experiment and its analysis are reported by taking advantage of a recent methodologic advance. By analyzing the mutation patterns with different levels of recessive lethality, earlier published conclusions based on partial data are found to remain valid. Furthermore, it is found that for most nearly lethal mutations, the mutation rate at the first cell division is even greater than previous thought compared with those at other divisions. There is also some evidence that the mutation rate at the second division decreases rapidly but is still appreciably greater than those for the rest of the cleavage stage. The mutation rate at spermatogenesis is greater than late cleavage and stem-cell stages, but there is no evidence that rates are different among the five cell divisions of the spermatogenesis. We also found that a modestly biased sampling, leading to slightly more primordial germ cells after the eighth division than those reported in the literature, provides the best fit to the data. These findings provide conceptual and numerical basis for exploring the consequences of differential mutation rates during individual development.

Robot-assisted laparoscopic myomectomy and adenomyomectomy with a flexible CO2 laser device.

We describe a novel surgical technique combining the use of a robotic surgical platform with a flexible CO2 laser in gynecologic surgery at a university-hospital-based reproductive medicine practice. Thirteen women with symptomatic uterine fibroids and/or adenomyosis, desiring uterine conservation, underwent robot-assisted laparoscopic myomectomy or focal adenomyomectomy with CO2 laser energy using a novel flexible delivery fiber (BeamPath GYN-L fiber, OmniGuide, Cambridge, MA, USA). On average, four myomas or areas of adenomyosis were removed with an average total specimen weight of 95 g. The average operating time was 169 min and the average estimated blood loss was 25 mL. No perioperative complications were observed. Preliminary experience with robot-assisted minimally invasive gynecologic surgery utilizing a novel flexible CO2 laser fiber has comparable operative outcomes to those reported for conventional laparoscopic energy sources, and this technique appears safe. The minimal lateral thermal spread of photonic energy, combined with the enhanced precision allowed by a computer-based surgical platform, appears ideal for reproductive surgical applications.

Early ß-human chorionic gonadotropin trends in vanishing twin pregnancies.

OBJECTIVE: To describe the early ß-hCG trends in vanishing twins compared with normally progressing singleton and twin pregnancies. DESIGN: Retrospective cohort study. SETTING: University-based infertility clinic. PATIENT(S): Women undergoing fresh IVF/intracytoplasmic sperm injection (ICSI) cycles between 1998 and 2010. INTERVENTION(S): Early ß-hCG level increase in vanished twin pregnancies was compared with the level increase in normally progressing singleton and twin pregnancies. MAIN OUTCOME MEASURE(S): Two-day percent increase in ß-hCG level. RESULT(S): Pregnancies with vanishing twins demonstrated a significantly lower mean 2-day percent increase in ß-hCG level than singletons and twins (114.3% vs. 128.8% and 125.4%, respectively). Vanishing twins arresting at earlier developmental stages demonstrated significantly further reduced ß-hCG level increases. Infrequently, all groups had ß-hCG level increases less than previously established clinical thresholds that led to a live birth. CONCLUSION(S): Early ß-hCG level increases are slower in vanishing twins than in singleton and twin pregnancies, with the slowest increases seen when the spontaneous fetal losses occur at earlier developmental stages. All increases, however, are within clinically accepted normal limits. Therefore, abnormal ß-hCG level increases should not be attributed to a vanishing twin. Of note, an abnormal ß-hCG level trend--even an initial decrease--does not preclude live birth, even in a singleton pregnancy.

Public opinion regarding utilization of assisted reproductive technology (ART) in obese women.

BACKGROUND: There have been calls to restrict access to fertility treatment in women above a certain body mass index (BMI). It is important to consider public expectations before formulating policy. The study objective was to assess public opinion regarding provision of assisted reproductive technology (ART) to obese (BMI>30 kg/m(2)) women in the United States. The study was conducted through an Internet-based survey of U.S. residents ages 18-75. METHODS: Multivariate odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using unconditional logistic regression to describe predictors of response based on demographic characteristics. RESULTS: Of the 1049 respondents, 60.7% support the use of ART in obese women. Adjusting for age and gender, the odds of support were over twice as high in participants with BMI>40 kg/m(2) as in normal-weight respondents (OR=2.87, 95% CI=1.28-6.44). Fifty-five percent of participants supported a BMI limit for access to ART. Both increasing education (p-value=0.02) and BMI (p-value=0.01) were inversely associated with support of a BMI limit. Individuals who had themselves used ART were also less likely (OR=0.27, 95% CI=0.07--0.99) to support a BMI limit. CONCLUSIONS: In an Internet-based survey, participants who are in favor of ART are likely to support its use among obese women. More than 50% of these respondents also support implementation of a BMI limit for access to these services.

Environmental lithium exposure in the north of Chile--II. Natural food sources.

Lithium, generally, occurs in barely trace amounts in ground water with few major exceptions. One of these is the northern area of Chile where all potable water and many of the food stuffs contain high levels of lithium. Surface water can contain between 100 and 10,000 times more than most rivers in North America. Inevitably, food, both animal and vegetable, contains higher lithium levels than found elsewhere. In consequence, the local population has been exposed to high levels of lithium in their food and drinking water for as long as the region has been populated. The present report details lithium levels in a variety of food stuffs from several locations in Northern Chile and compares these with those found elsewhere. The implications for the local population have been discussed in our earlier paper.

Female cancer survivors are low responders and have reduced success compared with other patients undergoing assisted reproductive technologies.

OBJECTIVE: To investigate the effect of prior chemotherapy and radiation on assisted reproductive technology (ART) outcomes. DESIGN: Retrospective cohort study. SETTING: University-based infertility clinic. PATIENT(S): Female cancer survivors who had received chemotherapy or radiation and all other women undergoing first-fresh IVF/intracytoplasmic sperm injection (ICSI) cycles. INTERVENTION(S): Survivors' ART outcomes were compared with all women undergoing first-fresh IVF/ICSI cycles and those with male-factor infertility only. Multivariate logistic and Poisson regression analyses were used to estimate the effect of cancer therapy on ART outcomes. MAIN OUTCOMES MEASURE(S): Number of oocytes retrieved and embryos obtained; odds of cycle cancelation, clinical pregnancy, and live birth. RESULT(S): Compared with others undergoing IVF/ICSI, survivors had significantly fewer oocytes retrieved and embryos available for transfer. In addition, survivors were significantly more likely to be canceled (odds ratio [OR] 5.60, 95% CI 2.94-10.66) and had lower pregnancy and live birth rates (OR 0.30, 95% CI 0.13-0.68; and OR 0.27, 95% CI 0.10-0.69; respectively). Odds ratios were stronger when the comparison group was restricted to those with male-factor infertility only. CONCLUSION(S): Women who have received systemic therapy for malignancy should be considered to be low responders and counseled that their per-cycle live birth rate is lower than that of their peers. These data strongly support offering fertility preservation before cancer therapy when possible.

Population-based study of attitudes toward posthumous reproduction.

OBJECTIVE: To measure public attitudes toward posthumous reproduction. DESIGN: Cross-sectional study. SETTING: Electronic survey. PATIENT(S): A total of 1,049 men and women living in the United States between the ages of 18 and 75 years. INTERVENTION(S): Multiple-choice questionnaire. MAIN OUTCOME MEASURE(S): Descriptive statistics regarding support for posthumous reproduction, such as regarding emergency harvesting of gametes, and attitudes toward consent; multivariable analyses of demographic and personal experiences associated with support for posthumous reproduction. RESULT(S): Results showed that 47.8% supported and 31.1% opposed retrieving gametes from men, and 42.7% supported and 35.9% opposed retrieving gametes from women. The remainder was undecided. Among supporters, 69.8% believed prior consent from the deceased was required. Support was positively associated with younger age, higher education, higher income, Democratic political party affiliation, history of infertility, and currently attempting conception. Gender, religion, race, and region of the country were not associated with support. Organ donors and those who support IVF were more likely to support posthumous reproduction (odds ratio [95% confidence interval] 1.68 [1.19-2.38] and 12.30 [6.56-23.04], respectively). Most respondents were initially unfamiliar with posthumous reproduction. CONCLUSION(S): Almost 50% of the general population support posthumous reproduction in men and women. The majority favored prior consent from the deceased. These data caution against emergency gamete harvesting without prior consent.

Transabdominal follicular aspiration for oocyte retrieval in patients with ovaries inaccessible by transvaginal ultrasound.

OBJECTIVE: To investigate the efficacy of ultrasound-guided transabdominal follicular aspiration when the ovaries are not accessible transvaginally. DESIGN: Retrospective case-control study. SETTING: University-hospital based in vitro fertilization (IVF) clinic. PATIENT(S): 69 women undergoing transabdominal follicular aspiration for oocyte retrieval, including 12 cases of mixed abdominal/vaginal aspiration, compared with controls matched by age, follicle number, and year of procedure undergoing standard transvaginal aspiration. INTERVENTION(S): Transabdominal follicular aspiration when one or more ovaries could not be retrieved via standard transvaginal aspiration. MAIN OUTCOME MEASURE(S): Total and mature oocytes retrieved, damaged oocytes, fertilization rate, embryo number and quality, and clinical and ongoing pregnancy rates. RESULT(S): Cases of transabdominal aspiration had slightly fewer oocytes retrieved, but no statistically significant differences were found for damaged oocytes, fertilization rates, embryo number and quality, or pregnancy rates. In 12 years, one complication requiring hospitalization was noted. CONCLUSION(S): This study demonstrates that transabdominal ultrasound-guided follicular aspiration is safe and efficacious, yielding clinical results in women with significant ovarian displacement, comparable with results achieved by transvaginal aspiration in women with normally positioned ovaries. Transabdominal ultrasound-guided aspiration should be the modality of choice when the ovaries are not accessible transvaginally.

Multivariate analysis of the association between oocyte donor characteristics, including basal follicle stimulating hormone (FSH) and age, and IVF cycle outcomes.

OBJECTIVE: To determine whether oocyte donor FSH and age are independently associated IVF cycle success. DESIGN: Retrospective cohort study. SETTING: University hospital-based IVF clinic. PATIENT(S): Three hundred twelve donor/recipient pairs undergoing oocyte donation IVF. MAIN OUTCOME MEASURE(S): Number of mature oocytes and embryos, clinical pregnancy, and live birth rates. RESULT(S): Donors' basal FSH levels were not associated with IVF cycle outcomes. However, for every year increase in donor age, the number of mature oocytes decreased by 0.39 and the number of embryos decreased by 0.25 resulting in 1 less embryo for each 4-year increase in age, even in young donors. For every 100 pg/mL increase in estradiol on the day of hCG administration, the number of mature oocytes increased by 0.49 and the number of embryos increased by 0.36. For each additional 75 IU of gonadotropin used during stimulation, the likelihood of pregnancy and live birth decreased by 3.5%. CONCLUSION(S): Donor oocyte IVF cycle outcomes were not associated with donor basal FSH. However, donor age and estradiol level on the day of hCG administration were significantly associated with numbers of mature oocytes and embryos obtained, and the amount of gonadotropin used in the stimulation was significantly associated with the likelihood of pregnancy and live birth.

Isolated teratozoospermia does not affect in vitro fertilization outcome and is not an indication for intracytoplasmic sperm injection.

OBJECTIVE: To reevaluate clinical management of isolated teratozoospermia, in couples initiating IVF. DESIGN: Retrospective analysis of fertility indices in 535 cycles. SETTING: A large, university-based fertility center. PATIENT(S): Consecutive couples (n = 495) who had a semen analysis using Kruger/Tyberberg strict criteria at our center within 12 months before undergoing their first and/or second IVF cycle in 2002-2004 with >2 million postwash, motile sperm on the day of egg retrieval. INTERVENTION(S): Eggs were fertilized either by conventional IVF or ICSI. Semen analysis and gamete/embryo manipulation was standardized in all cases. MAIN OUTCOME MEASURE(S): Fertilization, fertilization failure, pregnancy, and live birth rates. RESULT(S): There was no statistical difference in fertilization, fertilization failure, pregnancy, and live birth rates in the first or second IVF cycle when comparing couples with isolated teratozoospermia (<5% normal morphology) to those with a normal semen analysis. Furthermore, no improvement in these outcomes was noted when ICSI was used to treat these teratozoospermic couples. CONCLUSION(S): Because isolated teratozoospermia generally does not impact on the major indices of IVF, these patients need not be subjected to the unnecessary cost and potential risks of ICSI. Future studies, however, should focus on different sperm morphologic and biochemical parameters to determine if they are important for clinical management in IVF.

Admixture in Hispanics: distribution of ancestral population contributions in the Continental United States.

The effect of gene flow on Hispanic populations from different geographic regions of the United States was analyzed using six autosomal DNA markers (LDLR, GYPA, HBGG, D7S8, GC, and HLA-DQA). By region of sampling, the Hispanic populations showed different ancestry contributions, from a trihybrid structure with European, Native American, and African contributions (California, Nevada, Florida, New Jersey, and Virginia) to a dihybrid structure with European and American contributions (Southwest population) or European and African contributions (Pennsylvania and Southeast population). These findings allowed us to define two regional groups, the West and the East. In the former, Native American contributions ranged from 35.58% to 57.87%; in the East region the values ranged from 0% to 21.27%. An African influence was similar in both regions, ranging from 0% to 17.11%, with a tendency of increasing in the East region. These data reflect the different origins of the Hispanic populations that led to the present ones. In the West, Hispanics are mostly of Mexican origin, and in the East, they are predominantly of Cuban and Puerto Rican origin.

Measuring health beliefs in Spanish-speaking Mexican Americans with type 2 diabetes: adapting an existing instrument.

Mexican Americans bear a disproportionate burden of type 2 diabetes, and although clinicians and researchers are beginning to develop culturally competent interventions, few instruments are available for measuring variables relevant to health outcomes. The purpose of this study was to determine the psychometric properties of a diabetes-related health belief instrument translated for use with Spanish-speaking Mexican Americans. Three hundred and twenty-six Spanish-speaking Mexican Americans from Starr County, a Texas-Mexico border community, diagnosed with type 2 diabetes participated in the study. Factor analysis was used to examine the factor structure of the instrument, and reliability testing was conducted to determine the internal consistency of the resulting factors. The final instrument had 25 items with four subscales-Barriers, Social Support for Diet, Impact of Job on Therapy, and Benefits of Therapy-and one item to measure, Control. Internal consistency coefficients for these subscales were .56, .62, .86, and .90, respectively. The translated instrument needs to be tested over time with other Hispanic populations.

Maximum likelihood estimates of admixture in Northeastern Mexico using 13 short tandem repeat loci.

Tetrameric short tandem repeat (STR) polymorphisms are widely used in population genetics, molecular evolution, gene mapping and linkage analysis, paternity tests, forensic analysis, and medical applications. This article provides allelic distributions of the STR loci D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820, CSF1PO, TPOX, TH01, and D16S539 in 143 Mestizos from Northeastern Mexico, estimates of contributions of genes of European (Spanish), American Indian and African origin in the gene pool of this admixed Mestizo population (using 10 of these loci); and a comparison of the genetic admixture of this population with the previously reported two polymorphic molecular markers, D1S80 and HLA-DQA1 (n = 103). Genotype distributions were in agreement with Hardy-Weinberg expectations (HWE) for almost all 13 STR markers. Maximum likelihood estimates of admixture components yield a trihybrid model with Spanish, Amerindian, and African ancestry with the admixture proportions: 54.99% +/- 3.44, 39.99% +/- 2.57, and 5.02% +/- 2.82, respectively. These estimates were not significantly different from those obtained using D1S80 and HLA-DQA1 loci (59.99% +/- 5.94, 36.99% +/- 5.04, and 3.02% +/- 2.76). In conclusion, Mestizos of Northeastern Mexico showed a similar ancestral contribution independent of the markers used for evolutionary purposes. Further validation of this database supports the use of the 13 STR loci along with D1S80 and HLA-DQA1 as a battery of efficient DNA forensic markers in Northeastern Mestizo populations of Mexico.