Secular trends in response rates for controls selected by random digit dialing in childhood cancer studies: a report from the Children's Oncology Group

Since the mid-1990s, epidemiologists have anecdotally reported difficulty in recruiting controls using random digit dialing (RDD), but few empirical data have been published. From 1982 to 2003, epidemiologists from the Children's Oncology Group conducted 17 case-control studies using RDD controls. Data for calculating RDD and field response rates were available from eight and 13 of these studies, respectively. Over the period of analysis, the contact rate declined 2.5% per year (95% confidence interval (CI): -3.4, -1.6; p = 0.001), from above 90% in the 1980s to 63-69% in the most recent studies. The response rate (the product of the contact and cooperation rates) showed a decline parallel to that of the contact rate (-2.4% per year, 95% CI: -3.2, -1.6; p < 0.001), from above 80% in the 1980s to 50-67% after the mid-1990s. Field response rates appeared to have declined modestly. The overall response rate (the product of the RDD response and field response rates) paralleled that of the RDD response rate and decreased 2.4% per year (95% CI: -2.7, -2.0; p < 0.001). The current low response rates for RDD indicate a substantial potential for selection bias and a need to seek alternative sources of controls.

Birth characteristics, maternal reproductive history, and the risk of infant leukemia: a report from the Children's Oncology Group

Leukemias with MLL gene rearrangements predominate in infants (<1 year of age), but not in older children, and may have a distinct etiology. High birth weight, higher birth order, and prior fetal loss have, with varying consistency, been associated with infant leukemia, but no studies have reported results with respect to MLL status. Here, we report for the first time such an analysis. During 1999 to 2003, mothers of 240 incident cases (113 MLL(+), 80 MLL(-), and 47 indeterminate) and 255 random digit dialed controls completed a telephone interview. Odds ratios and 95% confidence intervals for quartile of birth weight, birth order, gestational age, maternal age at delivery, prior fetal loss, pre-pregnancy body mass index, and weight gain during pregnancy were obtained using unconditional logistic regression; P for linear trend was obtained by modeling continuous variables. There was a borderline significant linear trend of increasing birth weight with MLL(+) (P = 0.06), but not MLL(-) (P = 0.93), infant leukemia. Increasing birth order showed a significant inverse linear trend, independent of birth weight, with MLL(+) (P = 0.01), but not MLL(-) (P = 0.18), infant leukemia. Other variables of interest were not notably associated with infant leukemia regardless of MLL status. This investigation further supports the contention that molecularly defined subtypes of infant leukemia have separate etiologies.

Child and maternal household chemical exposure and the risk of acute leukemia in children with Down's syndrome: a report from the Children's Oncology Group

Compared with the general pediatric population, children with Down's syndrome have a much higher risk of acute leukemia. This case-control study was designed to explore potential risk factors for acute lymphoblastic leukemia and acute myeloid leukemia in children with Down's syndrome living in the United States or Canada. Mothers of 158 children with Down's syndrome and acute leukemia (97 acute lymphoblastic leukemia, 61 acute myeloid leukemia) diagnosed between January 1997 and October 2002 and mothers of 173 children with Down's syndrome but without leukemia were interviewed by telephone. Positive associations were found between acute lymphoblastic leukemia and maternal exposure to professional pest exterminations (odds ratio = 2.25, 95% confidence interval: 1.13, 4.49), to any pesticide (odds ratio = 2.18, 95% confidence interval: 1.08, 4.39), and to any chemical (odds ratio = 2.72, 95% confidence interval: 1.17, 6.35). Most of the associations with acute myeloid leukemia were nonsignificant, and odds ratios were generally near or below 1.0. This exploratory study suggests that household chemical exposure may play a role in the development of acute lymphoblastic leukemia in children with Down's syndrome.

Periconceptional vitamin useand leukemia risk in children with Down syndrome: a Children's Oncology Group study

BACKGROUND

Periconceptional vitamin supplementation reduces the risk of neural tube defects, and possibly may reduce the risk of certain childhood malignancies, including acute lymphoblastic leukemia (ALL). Because children with Down syndrome (DS) experience a 20-fold higher risk of leukemia than the general population, the authors evaluated whether periconceptional vitamin supplementation reduced the risk of leukemia in children with DS.

METHODS

From 1997 to 2002, 158 children ages birth-18 years with DS and acute leukemia (n = 61 children with acute myeloid leukemia [AML] and n = 97 children with ALL) were enrolled through the Children's Oncology Group in North America. Children with DS alone (n = 173) were identified through the cases' pediatric clinics and frequency matched to cases on age. Mothers of cases and controls completed a telephone interview that included questions regarding vitamin supplement use in the periconceptional period and after knowledge of pregnancy.

RESULTS

A decreased risk of leukemia was observed with vitamin supplementation in the periconceptional period (odds ratio [OR] = 0.63; 95% confidence interval [95% CI], 0.39-1.00). When stratified by leukemia type, the reduced risk was observed for ALL (OR = 0.51; 95% CI, 0.30-0.89), but not for AML (OR = 0.92; 95% CI, 0.48-1.76). Compared with vitamin use in the periconceptional period, use only after knowledge of pregnancy was associated with an increased risk of leukemia (OR = 1.61; 95% CI, 1.00-2.58). This was observed for both ALL and AML.

CONCLUSIONS

These data added to a growing body of evidence that suggests that periconceptional vitamin use may be protective in the development of certain childhood cancers.

Childhood and maternal infections and risk of acute leukaemia in children with Down syndrome: a report from the Children's Oncology Group

Children with Down syndrome (DS) are highly susceptible to acute leukaemia. Given the potential role of infections in the aetiology of leukaemia in children without DS, we investigated whether there was an association between early-life infections and acute leukaemia in children with DS. Maternal infections during pregnancy were also examined. We enrolled 158 incident cases of acute leukaemia in children with DS (97 acute lymphoblastic leukaemia (ALL) and 61 acute myeloid leukaemia (AML)) diagnosed at Children's Oncology Group institutions between 1997 and 2002. DS controls (N=173) were selected from the cases' primary care clinics and frequency matched on age at leukaemia diagnosis. Data were collected on demographics, child's medical history, mother's medical history, and other factors by maternal interview. Analyses were conducted using unconditional logistic regression adjusted for potential confounders. A significant negative association was observed between acute leukaemia and any infection in the first 2 years of life (adjusted odds ratio (OR)=0.55, 95% confidence interval (CI) (0.33–0.92); OR=0.53, 95% CI (0.29–0.97); and OR=0.59, 95% CI (0.28–1.25) for acute leukaemia combined, ALL, and AML respectively). The association between acute leukaemia and maternal infections during pregnancy was in the same direction but not significant. This study offers support for the hypothesis that early-life infections may play a protective role in the aetiology of acute leukaemia in children with DS.

Culturally congruent end-of-life care for Jewish patients and their families

This qualitative study was conducted to determine cultural influences in end-of-life care among Jewish people. The conceptual framework for this study was drawn from Leininger's culture care theory. Informants consisted of 16 professional caregivers, family members, and rabbis who had experience with end-of-life care for Jewish patients. Interviews using open-ended and focused questions were used to gather informants' descriptions of their generic values, beliefs, and practices. Findings revealed the strong influence of religious, cultural, and historical factors in caring. Sanctity of life and life promotion are central to Judaism. Caring is a communal obligation that unites the family and community into a cohesive unit. Attitudes toward death are influenced by beliefs about afterlife and suffering. The value put on expert knowledge influences patients' and family members' expectations of professional caregivers. Similarities and differences were noted among different groups of informants.

Minimal precycle testing and ongoing cycle monitoring for in vitro fertilization and fresh pre-embryo transfer do not compromise fertilization, implantation, or ongoing pregnancy rates

OBJECTIVE

We sought to assess the fertilization, implantation, and ongoing pregnancy rates with a minimal precycle and ongoing cycle monitoring protocol for in vitro fertilization and embryo transfer.

STUDY DESIGN

Retrospective review was conducted of 103 consecutive cycles of fresh in vitro fertilization and embryo transfer from 1996 to 1998. Precycle screening included semen analysis without strict morphologic analysis, and hysterosalpingography-sonohysterography within the last year. Serum prolactin, serum thyroid-stimulating hormone, reactive plasma reagin, human immunodeficiency virus, rubella titer, blood type, hepatitis B surface antigen, and hepatitis C antibody testing was performed on all patients within 3 months of cycle initiation. Women > or =37 years old underwent clomiphene challenge testing. The monitoring protocol included the following: baseline transvaginal ultrasonography after 12 to 14 days of midluteal gonadotropin-releasing hormone agonist down-regulation to assess endometrial thickness and adnexal appearance, transvaginal ultrasonography for follicle evaluation at 7 and 10 days, serum estradiol assay if > or =20 follicles, quantitative beta-human chorionic gonadotropin 12 to 14 days after pre-embryo transfer, repeat quantitative beta-human chorionic gonadotropin 3 to 5 days later, and transvaginal ultrasonography for intrauterine gestational sac confirmation 7 to 9 days after the initial positive pregnancy test result. The dose of gonadotropin used remained constant unless the sonogram obtained on day 7 indicated a suboptimal response (<3 follicles each, with an average diameter of 10 to 12 mm) or hyperresponse (> or =15 follicles with an average diameter of 10 to 12 mm).

RESULTS

The per embryo implantation rate (fetal cardiac activity) was 13.1%, and the live birth rate per 100 pre-embryo transfers was 31.5 for patients < or =40 years old. The average number of pre-embryos transferred was 3.1. The singleton pregnancy rate was 71%, and there were no multiple gestations greater than twins. The mean number of oocytes fertilized was 66%. There was 1 case of failed fertilization with intracytoplasmic sperm injection. There were two other cases of failed fertilization. One case of severe ovarian hyperstimulation occurred in spite of cryopreservation of all embryos.

CONCLUSIONS

In vitro fertilization and embryo transfer can be accomplished with minimal precycle testing and ongoing cycle monitoring without compromising fertilization, implantation, and ongoing pregnancy rates. This results in reduced overall costs for couples.

Loss of functional hemispheric asymmetry in Alzheimer's dementia assessed with near-infrared spectroscopy

In a total of 10 patients with dementia of the Alzheimer-type (DAT) and in 10 healthy controls near-infrared spectroscopy (NIRS), a new non-invasive optical method, was used to measure the changes of concentrations of oxy- (O2HB) and deoxyhemoglobin (HHB) in left and right hemispheric prefrontal brain tissue areas during performance of the Verbal Fluency Test (VFT). On a neuropsychological level, the healthy subjects performed better in the VFT than patients with DAT. Statistical analysis of the relative concentrations of O2HB and HHB measured with NIRS during performance of the VFT revealed a significant interaction of the hemispheric effects with the diagnosis. A possible interpretation of this finding is that a good performance in the VFT relies on a predominantly left hemispheric activation observed in controls, whereas a low number of correct responses is associated with a loss of this asymmetric activation in patients with DAT. Although both, patients and controls, performed better in the category version of the VFT, the metabolic effects of this task were significantly less pronounced than in the letter version. This indicates that different energy demands, according to the type of access to the memory stores, may be interpreted as the result of a less energy-demanding access to categorically stored information and adds further evidence to the view that memory departments in humans are organized according to categorical principles.

Cryopreservation of human embryos as a useful tool for infertile couples

In order to improve the pregnancy rate per oocyte retrieval while reducing the chance of multiple-gestations, a technique of cryopreservation of human embryos was used for our initial study consisting of 100 infertile patients undergoing in vitro fertilization (IVF) procedure. These patients combined a "fresh" embryo transfer with cryopreservation. The embryos were cryopreserved with 1,2-propanediol. Twenty-nine (29%) patients achieved ongoing pregnancies from the fresh embryo transfer. Thirty patients received a transfer of thawed embryos in a natural cycle. Nine of these patients achieved ongoing pregnancies. Combining these 2 transfers results in a 38% ongoing pregnancy rate. Forty-one patients have yet to receive their frozen embryos. The current success rate in this study indicates that over 50% of the patients in this group can expect to become pregnant by the time all the cryopreserved embryos have been transferred.

Treatment of human spermatozoa with an egg yolk medium can enhance the outcome of in vitro fertilization

In at least 4 of 7 cases, fertilization of intact human oocytes was more successful when spermatozoa were pretreated with TEST yolk medium at 5 degrees C for 2 hours as compared with the standard treatment with Ham's F-10 only. Both pregnancies that were obtained after the transfer of the fertilized oocytes resulted from oocytes fertilized by TEST yolk-treated spermatozoa. No decrease in fertilization occurred in any of the cases after TEST yolk treatment. If these results hold true for a larger series of patients, it may be worthwhile for the standard IVF incubation system of spermatozoa to include TEST yolk.

Karyotype analysis of blighted ova in pregnancies achieved by in vitro fertilization

Pregnancies achieved by IVF and resulting in blighted ovum were karyotyped. The rate of aneuploidy was found to be 38% (5/13). In vitro fertilization does not appear to be a risk factor for chromosome anomaly in live births or miscarriages, and the data reported so far may suggest that aneuploid rates are actually lower for pregnancies achieved by IVF.

[Doppler echocardiographic analysis of the short-term results of surgical repair of mitral valve prolapse in myxomatous degeneration]

Ten consecutive patients with pure mitral regurgitation due to floppy valve underwent valve repair operations. Postoperative mitral continence or regurgitation and diastolic flow across the valve were evaluated by Doppler echocardiography. Mean follow-up was 6.4 months. Four patients showed minimal and 3 mild regurgitation; no regurgitation was detected in 3. A significant peak diastolic atrioventricular gradient (10 mmHg) was observed in only one patient. All patients showed symptomatic improvement and a decrease in ventricular diameters. Repair of floppy mitral valves is feasible and gives good results. Doppler echocardiography is a useful technique for monitoring postoperative valve function.

Short-term use of gonadotropin-releasing hormone agonist (leuprolide) for in vitro fertilization

A common problem encountered by in vitro fertilization (IVF) programs is the premature occurrence of the spontaneous luteinizing hormone (LH) surge during ovarian stimulation cycles. Administration of gonadotropin-releasing hormone agonists (GnRH-a) for 2 to 3 weeks produces a state of hypogonadotropic hypogonadism, thus allowing ovarian stimulation to proceed uncomplicated by a spontaneous LH surge. We have elected to treat seven patients with GnRH-a in a "short-term" protocol, with GnRH-a initiated on cycle day 3 along with exogenous gonadotropins. In this series, we found that the spontaneous LH surge was abolished, while ovarian responsiveness seemed to be improved. These results suggest that the initial surge of gonadotropins elicited by GnRH-a administration may enhance ovarian stimulation and that spontaneous LH surge is blocked when GnRH-a and exogenous gonadotropins are initiated concomitantly.

Ultrasound-guided transvaginal needle aspiration of follicles for in vitro fertilization

In search of a simpler and less traumatic method of oocyte retrieval for in vitro fertilization (IVF), 37 infertile patients underwent ultrasound-guided transvaginal needle aspiration of the follicles instead of the conventional laparoscopic aspiration. Although only intravenous analgesics and sedatives were used, patients experienced little discomfort. There were no infections or bleeding complications after the procedure. Eleven patients (30%) achieved ongoing pregnancies; this rate of success is comparable to that with our laparoscopic method. Considering this reasonable pregnancy rate, lack of substantial morbidity, and good patient acceptance, laparoscopic oocyte retrieval for IVF can be largely replaced by the ultrasound-guided transvaginal needle aspiration technique.

The diagnosis of airway obstruction in children

Airway obstruction in children has many causes. Although vascular rings may have early onset of symptoms there was considerable delay in establishing the correct diagnosis. Barium swallow is diagnostic. Other tests, such as angiocardiography, bronchoscopy, bronchography, and lung scan are usually unnecessary. Pulmonary sling is a less common cause of vascular obstruction. Barium swallow showing anterior indentation at the level of the pulmonary hilum is diagnostic. Cysts and tumors are other causes of severe airway obstruction. The diagnostic and operative problems in three patients are discussed as examples. It is concluded that barium swallow is the most important single investigation in the evaluation of airway obstruction.