Recent Publications by CFE Educators

Genes involved in the nucleotide excision repair (NER) pathway, which removes bulky DNA adducts, are potential low-penetrance cancer susceptibility genes. We recently reported an association between detectable polycyclic aromatic hydrocarbon (PAH)-DNA adducts and breast cancer risk. Using a population-based breast cancer case-control study on Long Island, New York, we examined whether polymorphisms in NER genes modified the association between PAH-DNA adducts and breast cancer risk. We examined polymorphisms in ERCC1 (3'-untranslated region 8092C/A), XPA (5'-untranslated region -4G/A), XPD (Asp(312)Asn in exon 10), XPF (Arg(415)Gln in exon 8), and XPG (Asp(1104)His in exon 15) in 1,053 breast cancer cases and 1,102 population-based controls. The presence of at least one variant allele in XPD was associated with a 25% increase in the odds ratio [OR, 1.25; 95% confidence interval (95% CI), 1.04-1.50] for breast cancer. The increase associated with homozygosity of the variant alleles for XPD and ERCC1 was stronger among those with detectable PAH-DNA adduct levels (OR, 1.83; 95% CI, 1.22-2.76 and OR, 1.92; 95% CI, 1.14-3.25 for detectable versus nondetectable adducts and homozygous wild-type genotype for XPD and ERCC1, respectively). We found no association between XPA, XPF, and XPG genotypes, PAH-DNA adducts, and breast cancer risk. When we combined genotypes for these NER pathway genes, there was a significant trend for increasing breast cancer risk with increasing number of putative high-risk alleles. Overall, this study suggests that the risk of breast cancer may be elevated among women with polymorphisms in NER pathway genes and detectable PAH-DNA adducts.

Larval behavioral patterns arise in a gradual fashion during late embryogenesis as the innervation of the somatic musculature and connectivity within the central nervous system develops. In this paper, we describe in a quantitative manner the maturation of behavioral patterns. Early movements are locally restricted "twitches" of the body wall, involving single segments or parts of segments. These twitches occur at a low frequency and have low amplitude, reflecting weak muscle contractions. Towards later stages twitches increase in frequency and amplitude and become integrated into coordinated movements of multiple segments. Most noticeable among these is the peristaltic wave of longitudinal segmental contractions by which the larva moves forward or backward. Besides becoming more complex as development proceeds, embryonic movements also acquire a pronounced rhythm. Thus, late embryonic movements occur in bursts, with phases of frequent movement separated by phases of no movement at all; early movements show no such periodicity. These data will serve as a baseline for future studies that address the function of embryonic lethal genes controlling neuronal connectivity and larval behavior. We have analyzed behavioral abnormalities in two embryonic lethal mutations with severe neural defects, tailless (tll), which lacks the protocerebrum, and glial cells missing (gcm), in which glial cells are absent. Our results reveal prominent alterations in embryonic motility for both of these mutations, indicating that the protocerebrum and glial cells play a crucial role in the neural mechanism controlling larval movement in Drosophila.

OBJECTIVE

The purpose of this study was to examine the relationship between prepregnancy body mass index (BMI) and length of gestation at term.

STUDY DESIGN

This was a retrospective study of 9336 births at the University of California, San Francisco, at > or = 37 weeks' gestation. We performed univariate and multivariable analyses of the associations between prepregnancy BMI and length of gestation (> or = 40, > or = 41, and > or = 42 weeks' gestation).

RESULTS

Overweight women were more likely to deliver at > or = 40, > or = 41, and > or = 42 weeks' gestation than were women who were underweight or normal weight. In multivariable analyses, higher prepregnancy BMI was associated with higher risk of progressing past 40 weeks. Obese women had 69% higher adjusted odds of reaching 42 weeks' gestation, compared with women of normal prepregnancy BMI (adjusted odds ratio, 1.69; 95% confidence interval, 1.23-2.31).

CONCLUSION

Higher BMI is associated with prolonged gestation at term. Achieving optimal BMI before conception may reduce the risk of postterm pregnancy and its associated complications.

BACKGROUND

Plate fixation of clavicular fractures is technically difficult because of the complex anatomy of the bone, with an S-shaped curvature and a cephalad-to-caudad bow. The purpose of the present study was to characterize variations in clavicular anatomy and to determine the clinical applicability of an anatomic precontoured clavicular plate designed for fracture fixation.

METHODS

One hundred pairs of clavicles were analyzed. The location and magnitude of the superior clavicular bow were determined with use of a digitizer and modeling software. Axial radiographs were made of each clavicle and the precontoured Acumed Locking Clavicle Plate, which is designed to be applied superiorly. With use of Adobe Photoshop technology, the plates were freely translated and rotated along each clavicle to determine the quality of fit and the location of the "best fit."

RESULTS

The location of the maximum superior bow was lateral, with a mean distance of 37.2 +/- 18.4 mm from the acromial articulation and with a mean magnitude of 5.1 +/- 5.9 mm. There was no significant difference in the location or magnitude of the apex of the bow between specimens from male and female donors. The anatomic precontoured clavicular plate had the best fit in specimens from black male donors and the worst fit in specimens from white female donors, with a poor fit being seen in 38% (nineteen) of the fifty specimensfrom white female donors. The best location for superior plate application was along the medial aspect of the clavicle.

CONCLUSIONS

The apex of the superior bow of the clavicle is typically located along the lateral aspect of the bone, whereas the medial aspect of the superior surface of the clavicle remains relatively flat, making it an ideal plating surface. The precontoured anatomic clavicular plate appears to fit the S-shaped curvature on the superior surface of the majority of clavicles in male patients but may not be as conforming in white female patients. While this plate fits in the medial three-fifths of the clavicle, it does not fit as well laterally.