Neurological complications caused by desmopressin in adults with nocturia

Desmopressin is occasionally used to reduce the frequency of nocturnal toilet visits. We describe an 86-year-old woman with nocturnal incontinence due to a urinary tract infection, and a 49-year-old man with frequent toilet visits in the night, known to consume excessive amounts of alcohol. They were admitted to hospital with neurological symptoms due to severe hyponatraemia, 114 and 102 mmol/l respectively, while using desmopressin. After the desmopressin had been discontinued and the fluid balance restored, they recovered completely. Hyponatraemia is inherent to the mechanism of action of desmopressin. Desmopressin should be prescribed only on sound indication, and risk factors for developing severe hyponatraemia should always be taken into consideration. Proper instruction and follow-up are important to prevent severe complications.     

Females and males are highly similar in language performance and cortical activation patterns during verb generation

ObjectiveTo test the existence of sex differences in cortical activation during verb generation when performance is controlled for.MethodsTwenty male and 20 female healthy adults underwent functional magnetic resonance imaging (fMRI) using a covert block-design verb generation task (BD-VGT) and its event-related version (ER-VGT) that allowed for intra-scanner recordings of overt responses. Task-specific activations were determined using the following contrasts: BD-VGT covert generation > finger-tapping; ER-VGT overt generation > repetition; ER-VGT overt > covert generation. Lateral cortical regions activated during each contrast were used for calculating language lateralization index scores. Voxelwise regressions were used to determine sex differences in activation, with and without controlling for performance. Each brain region showing male/female activation differences for ER-VGT overt generation > repetition (isolating noun–verb association) was defined as a region of interest (ROI). For each subject, the signal change in each ROI was extracted, and the association between ER-VGT activation related to noun–verb association and performance was assessed separately for each sex.ResultsMales and females performed similarly on language assessments, had similar patterns of language lateralization, and exhibited similar activation patterns for each fMRI task contrast. Regression analysis controlling for overt intra-scanner performance either abolished (BD-VGT) or reduced (ER-VGT) the observed differences in activation between sexes. The main difference between sexes occurred during ER-VGT processing of noun–verb associations, where males showed greater activation than females in the right middle/superior frontal gyrus (MFG/SFG) and the right caudate/anterior cingulate gyrus (aCG) after controlling for performance. Better verb generation performance was associated with increased right caudate/aCG activation in males and with increased right MFG/SFG activation in females.ConclusionsMales and females exhibit similar activation patterns during verb generation fMRI, and controlling for intra-scanner performance reduces or even abolishes sex differences in language-related activation. These results suggest that previous findings of sex differences in neuroimaging studies that did not control for task performance may reflect false positives.     

Comparison of the use of isotopic proline vs leucine to measure protein synthesis in cultured fibroblasts

Compartmentation of the amino acid precursor pools for protein synthesis in cultured cells can substantially complicate measurements of synthesis rates. This is particularly true for nonessential amino acids such as proline, an amino acid often used in isotopic form to measure collagen synthesis. We have made a comparative study of this problem in cultured IMR-90 fibroblasts using isotopic proline and leucine to measure total protein and collagen synthesis. 3H-leucine in the extracellular (EC) medium equilibrates with tRNA-leucine at an EC concentration of 0.4 mM in both dividing and stationary cells. Thus, under these experimental conditions there is no complicating compartmentation of leucine for protein synthesis. Equilibration of EC and tRNA-bound 3H-proline, however, does not occur even when the EC concentration is in the mM range, based upon simultaneous measurements of synthesis rates using 3H-proline and 3H-leucine together. Furthermore, significant changes in EC proline concentration and specific activity occur over short time intervals (2 hr) if the initial EC proline concentration is below 0.2 mM. Thus, the use of isotopic proline to measure protein synthesis introduces substantial interpretive problems. Serum deprivation causes changes in both total collagen synthesis and the percent of protein synthesis devoted to collagen when measured with either 14C-leucine or 3H-proline. At the same time, isotopic proline remains the better choice for measuring percent collagen synthesis.     

Development and feasibility of a parental support intervention for adolescent smokers

The aim of this investigation was to develop and evaluate the feasibility and acceptability of a parental support intervention. A new measure of perceived parental support for stopping smoking was also developed. The sample included 59 adolescent-parent pairs recruited from a mid-sized Midwestern town during 2000-2003. The mean +/- SD age of the participants (32 males, 27 females) was 16.3 +/- 0.9 (range 14-18) years and 86% were Caucasian, 7% American Indian, 5% African American, and 2% Hispanic. Participants were randomized to parental support or minimum behavioral intervention. Severity of nicotine dependence was evaluated using the Fagerstr?m Tolerance Questionnaire, and perceived social support was evaluated using the Family Environment Scale and the new measure of perceived parent support for stopping smoking that was developed as part of this investigation. Treatment attendance, adherence, and acceptability were also evaluated. The parental support intervention was feasible but not superior to the minimum behavioral intervention with respect to attendance, retention, or change in support. This study expands on the knowledge of treating adolescent smokers and presents a new assessment measure. The study's limitations are noted. This investigation was funded by NICHHD.     

Deletions spanning the neurofibromatosis type 1 gene: Implications for genotype-phenotype correlations in neurofibromatosis type 1?

Neurofibromatosis type 1 (NF1) is an autosomal-dominant disorder characterized by abnormalities of tissues predominantly derived from the neural crest. Symptoms are highly variable and severity cannot be predicted, even within families. DNA of 84 unrelated patients with NF1, unselected for clinical features or severity, were screened with intragenic polymorphic repeat markers and by Southern analysis with cDNA probes. Deletions of the entire gene were detected in five patients from four unrelated families. Their phenotype resembled that of five previously reported patients with deletions, including intellectual impairment and dysmorphic features, but without an excessive number of dermal neurofibromas. This report supports the hypothesis that large deletions spanning the entire NF1 gene may lead to a specific phenotype. Hum Mutat 9:458–464, 1997 © 1997 Wiley-Liss, Inc.     

Advanced General Dentistry program directors' attitudes on physician involvement in pediatric oral health care

Childhood oral disease is a significant health problem, particularly for vulnerable populations. Since a major focus of General Dentistry Program directors is the management of vulnerable populations, we wanted to assess their attitudes regarding the inclusion of physicians in the prevention, assessment, and treatment of childhood oral disease. A survey was mailed to all General Practice Residency and Advanced Education in General Dentistry program directors (accessed through the ADA website) to gather data. Spearman's rho was used to determine correlation among variables due to nonnormal distributions. Overall, Advanced General Dentistry directors were supportive of physicians' involvement in basic aspects of oral health care for children, with the exception of applying fluoride varnish. The large majority of directors agreed with physicians' assessing children's oral health and counseling patients on the prevention of dental problems. Directors who treated larger numbers of children from vulnerable populations tended to strongly support physician assistance with early assessment and preventive counseling.