Gene-environment interaction in patterns of adolescent drinking: regional residency moderates longitudinal influences on alcohol use

BACKGROUND: Drinking frequency escalates rapidly during adolescence. Abstinence declines markedly, and drinking monthly or more often becomes normative. Individual differences in adolescent drinking patterns are large, and some patterns are predictive of subsequent drinking problems; little, however, is known of the gene-environment interactions that create them. METHODS: Five consecutive and complete birth cohorts of Finnish twins, born 1975-1979, were enrolled sequentially into a longitudinal study and assessed, with postal questionnaires, at ages 16, 17, and 18.5 years. The sample included 1786 same-sex twin pairs, of whom 1240 pairs were concordantly drinking at age 16. Maximum likelihood models were fit in longitudinal analyses of the three waves of drinking data to assess changes in genetic and environmental influences on alcohol use across adolescence. Secondary analyses contrasted twin pairs residing in rural versus those in urban environments to investigate gene-environment interactions. RESULTS: Longitudinal analyses revealed that genetic factors influencing drinking patterns increased in importance across the 30-month period, and effects arising from common environmental influences declined. Distributions of drinking frequencies in twins residing in urban and rural environments were highly similar, but influences on drinking varied between the two environments. Genetic factors assumed a larger role among adolescents residing in urban areas, while common environmental influences were more important in rural settings. Formal modeling of the data established a significant gene-environment interaction. CONCLUSIONS: The results document the changing impact of genetic and environmental influences on alcohol use across adolescence. Importantly, the results also reveal a significant gene-environment interaction in patterns of adolescent drinking and invite more detailed analyses of the pathways and mechanisms by which environments modulate genetic effects.     

Combined static-dynamic MR urography for the simultaneous evaluation of morphology and function in urinary tract obstruction

PURPOSE: To assess the diagnostic value of combined static-dynamic MR urography (MRU) for the functional-morphological evaluation of experimentally induced urinary tract obstruction in the piglet. MATERIALS AND METHODS: In 20 piglets unilateral ureteric stenosis was created operatively. Post-surgery repeated comparative examinations were obtained with MRU, diuretic renal scintigraphy (DRS), excretory urography (EU) and ultrasound (US). MRU was performed as a combination study with a static 3D-IR-TSE sequence and a dynamic 2D-FFE sequence after Gd-DTPA with frusemide administration. RESULTS: MRU allowed complete depiction of the prestenotic urinary tract and of the stenosis in all cases. In 43 comparative studies MRU was superior to EU in 36, EU to MRU in 2. When single kidney function was calculated with both MRU and DRS, results were highly correlated (r = 0.92). When urinary excretion was compared, significant agreement was achieved with concordant findings in 86% and slightly discordant results in 12%. CONCLUSIONS: Static-dynamic MR urography permits excellent depiction of experimentally induced urinary tract obstruction in piglets and reliable assessment of individual renal function and urinary excretion. Two advantages of the method stand out--it does not require radiation and it permits functional-morphological correlation.     

Cognitive functioning in children on dialysis and post-transplantation

We studied 124 children, 62 patient-subjects who had end-stage renal disease (ESRD) and 62 sibling-controls who closely matched the patient-subjects in terms of their ethnicity and their socioeconomic status, to discern whether children with ESRD would perform less well than their siblings on standardized achievement and intelligence quotient (IQ) tests, and to determine whether ethnicity would influence such results. The subjects were recruited from nine pediatric transplant and dialysis centers across the United States. Thirty-one subjects were white (Euro-American), 17 were African-American, and 14 were categorized as 'other'. The average age of the patient-subjects was 13.7 +/- 0.44 yr; and of the sibling-controls 13.7 +/- 0.38 yr. Most patients (61%) and siblings (84%) were in regular school classes, and most (87% and 92%, respectively) attended school full-time. The average IQ percentile rank for the patients was significantly lower than their siblings (31 +/- 4 vs. 44 +/- 5, respectively, with normal = 50). Patients tended to score lower on achievement tests compared with their siblings (spelling: 88.7 +/- 4 vs. 94.6 +/- 2; arithmetic: 88.5 +/- 2 vs. 94.0 +/- 2; reading: 91.9 +/- 2 vs. 100 +/- 3, respectively). Patients scores on achievement tests were influenced by age at diagnosis and by the mother/caregiver's lower achievement. Also, increased time on dialysis predicted lower scores on achievement tests. Neither dialysis/transplant status nor ethnicity significantly affected outcome. Our data suggest that ESRD, but not ethnicity or dialysis/transplant status, is a risk factor for lower IQ and academic achievement, especially in younger children, in children who spend more time living with ESRD, and in children whose mother's/caregiver's have lower educational levels.     

Malignant pericardial effusion from squamous cell cancer of the cervix

Although rarely diagnosed in women with gynecologic cancers, pericardial metastasis and effusion are often considered preterminal events. As newer therapies result in prolongation of survival for women with advanced cervical cancer, uncommon metastatic sites may be seen with increasing frequency, and warrant increased attention by the gynecologist with oncologic expertise. Cases: Two women with squamous cell carcinoma and symptomatic pericardial effusion, one at initial presentation and the other as recurrent disease, are presented. Following pericardiocentesis, both patients received cisplatinum-based chemotherapy. The patient with effusion at diagnosis survived four months, with recurrent effusion at death. The second patient had no return of cardiac symptoms, with twelve month survival. As demonstrated by the cumulative experience of the six reported cases of this entity, many women with pericardial involvement are candidates for aggressive radiation or chemotherapy. Duration of time from primary therapy prior to occurrence of effusion correlates with survival. © 1993 Wiley-Liss, Inc.     

Sensorineural hearing loss from quinolinic acid: A neurotoxin in middle ear effusions

Quinolinic acid (QUIN) is an endogenous metabolite that exerts a neurotoxic effect by binding to specific neuronal receptors. Studies involving a broad spectrum of infectious and inflammatory central nervous system diseases have suggested a role for QUIN in causing neuronal injury. Since there is evidence for presence of the QUIN receptor in mammalian cochleas, QUIN was measured in middle ear effusions (MEEs). Gas chromatography/mass spectrometry detected QUIN in each of 65 diluted human MEEs, with a mean of 482 ± 75 (SEM) nmol/L and a range from 15 to 2667 nmol/L. QUIN was also detected in each of 197 chinchilla MEEs from five different models of otitis media, with a mean of 10.6 ± 1.3 (SEM) μmol/L and a range from 0.23 to 146.0 μmol/L (corrected for dilution). To determine whether QUIN causes sensorineural hearing loss (SNHL), QUIN solutions were placed on round window membranes (RWM) for 20 to 240 minutes, in 20 chinchillas. SNHL was detected by electocochleography in QUIN-exposed animals, but not in saline controls. We conclude that QUIN is present in MEEs and that QUIN in the middle ear has the potential to cross the RWM and cause sensorineural hearing loss, possibly by binding to specific neuronal receptors in mammalian cochleas.     

Tobacco interventions by oncology nurses in clinical practice: report from a national survey

BACKGROUND: Tobacco use is an important risk factor in cancer, cancer recurrence, and increased treatment morbidity, but limited information is available about interventions for tobacco cessation used in oncology clinical practice. In 1996, the Agency for Health Care Policy Research (AHCPR) published the first evidence-based smoking cessation guideline for use by health professionals. Using the AHCPR guideline as a framework, the authors describe the frequency of tobacco interventions provided by oncology nurses. METHODS: A questionnaire was mailed to 4000 randomly selected members of the Oncology Nursing Society in winter of 1998. Of those who were mailed questionnaires, 1508 respondents (38%) were available for analysis. RESULTS: The typical respondent was female, 44 years of age, and had practiced as an oncology nurse for 12 years. Seven percent were current smokers, and 30% were former smokers. Most (86%) encountered smokers on a weekly basis, but only 10% had heard of the AHCPR guideline. The majority (64%) assessed and documented tobacco status, 38% assessed readiness to quit. Few went on to provide interventions: 36% provided counseling, 32% provided cessation advice, 24% recommended nicotine replacement, and 16% taught skills to prevent relapse. Common barriers included perceived lack of patient motivation (74%) and the nurse's lack of time (52%) and skills (53%). The majority stated that they wanted to help patients stop smoking (88%) but needed additional training (92%). CONCLUSIONS: Documentation of tobacco status alone is not adequate in assisting patients with smoking cessation. Greater efforts are needed to educate oncology nurses about the range of tobacco interventions available and to facilitate their use in clinical settings.     

Height and weight at menarche and a hypothesis of menarche

Height and weight at menarche were estimated by interpolation of longitudinal growth data for 181 girls. Mean weight at menarche, about 48 kg, does not change as menarcheal age increases, whereas mean height increases significantly. Early and late menarcheal girls gain the same amount of height, about 22 cm, and the same amount of weight, about 17 kg, in the interval from the initiation of the adolescent spurt to menarche, though late maturers grow at slower rates during the spurt, including the year of menarche. A hypothesis of a direct relation between a critical weight and menarche is proposed. Such an interaction would explain the delaying effect of malnutrition on menarche and the secular trend to an earlier menarche.