Mindfulness and Sexual Mindfulness as Moderators Between Conflict Resolution and Sexual and Relationship Satisfaction

Mindfulness has shown positive links with conflict resolution. Additionally, couples skilled in conflict resolution report greater sexual and relationship satisfaction. However, no research has examined the moderating effect of mindfulness, specifically sexual mindfulness, between conflict resolution and sexual and relationship satisfaction. We used 1,627 couples from wave III of the Couple Relationships and Transition Experiences (CREATE) study. Sexual mindfulness moderated the association between conflict resolution and sexual satisfaction, even after controlling for attachment. Wives higher in sexual mindful awareness may rely less on conflict resolution for their sexual satisfaction. Karremans and colleagues' (2017) model of mindfulness and romantic relationships provides a framework for testing whether, when, and how mindfulness increases positive romantic relationship processes and outcomes. Under this framework, mindfulness may provide a mechanism to help couples achieve sexual and relationship satisfaction. Mindfulness and sexual mindfulness may provide a useful mechanism for therapists, educators, social workers, and couples to enhance satisfaction within the romantic and sexual relationship even without partner buy-in.

Cognitive performance of GBA mutation carriers with early-onset PD: the CORE-PD study

OBJECTIVE

To assess the cognitive phenotype of glucocerebrosidase (GBA) mutation carriers with early-onset Parkinson disease (PD).

METHODS

We administered a neuropsychological battery and the University of Pennsylvania Smell Identification Test (UPSIT) to participants in the CORE-PD study who were tested for mutations in PARKIN, LRRK2, and GBA. Participants included 33 GBA mutation carriers and 60 noncarriers of any genetic mutation. Primary analyses were performed on 26 GBA heterozygous mutation carriers without additional mutations and 39 age- and PD duration-matched noncarriers. Five cognitive domains, psychomotor speed, attention, memory, visuospatial function, and executive function, were created from transformed z scores of individual neuropsychological tests. Clinical diagnoses (normal, mild cognitive impairment [MCI], dementia) were assigned blind to genotype based on neuropsychological performance and functional impairment as assessed by the Clinical Dementia Rating (CDR) score. The association between GBA mutation status and neuropsychological performance, CDR, and clinical diagnoses was assessed.

RESULTS

Demographics, UPSIT, and Unified Parkinson's Disease Rating Scale-III performance did not differ between GBA carriers and noncarriers. GBA mutation carriers performed more poorly than noncarriers on the Mini-Mental State Examination (p = 0.035), and on the memory (p = 0.017) and visuospatial (p = 0.028) domains. The most prominent differences were observed in nonverbal memory performance (p < 0.001). Carriers were more likely to receive scores of 0.5 or higher on the CDR (p < 0.001), and a clinical diagnosis of either MCI or dementia (p = 0.004).

CONCLUSION

GBA mutation status may be an independent risk factor for cognitive impairment in patients with PD.

CAG repeat expansion in Huntington disease determines age at onset in a fully dominant fashion

OBJECTIVE

Age at onset of diagnostic motor manifestations in Huntington disease (HD) is strongly correlated with an expanded CAG trinucleotide repeat. The length of the normal CAG repeat allele has been reported also to influence age at onset, in interaction with the expanded allele. Due to profound implications for disease mechanism and modification, we tested whether the normal allele, interaction between the expanded and normal alleles, or presence of a second expanded allele affects age at onset of HD motor signs.

METHODS

We modeled natural log-transformed age at onset as a function of CAG repeat lengths of expanded and normal alleles and their interaction by linear regression.

RESULTS

An apparently significant effect of interaction on age at motor onset among 4,068 subjects was dependent on a single outlier data point. A rigorous statistical analysis with a well-behaved dataset that conformed to the fundamental assumptions of linear regression (e.g., constant variance and normally distributed error) revealed significance only for the expanded CAG repeat, with no effect of the normal CAG repeat. Ten subjects with 2 expanded alleles showed an age at motor onset consistent with the length of the larger expanded allele.

CONCLUSIONS

Normal allele CAG length, interaction between expanded and normal alleles, and presence of a second expanded allele do not influence age at onset of motor manifestations, indicating that the rate of HD pathogenesis leading to motor diagnosis is determined by a completely dominant action of the longest expanded allele and as yet unidentified genetic or environmental factors.

The relation between depression and parkin genotype: the CORE-PD study

BACKGROUND

Mutations in parkin are a known genetic risk factor for early onset Parkinson's disease (EOPD) but their role in non-motor manifestations is not well established. Genetic factors for depression are similarly not well characterized. We investigate the role of parkin mutations in depression among those with EOPD and their relatives.

METHODS

We collected psychiatric information using the Patient Health Questionnaire and Beck Depression Inventory II on 328 genotyped individuals including 88 probands with early onset PD (41 with parkin mutations, 47 without) and 240 first and second-degree relatives without PD.

RESULTS

Genotype was not associated with depression risk among probands. Among unaffected relatives of EOPD cases, only compound heterozygotes (n = 4), and not heterozygotes, had significantly increased risk of depressed mood (OR = 14.1; 95% CI 1.2-163.4), moderate to severe depression (OR = 17.8; 95% CI 1.0-332.0), depression (score ≥ 15) on the Beck Depression Inventory II (BDI-II) (OR = 51.9; 95% CI 4.1-657.4), and BDI-II total depression score (β = 8.4; 95% CI 2.4-11.3) compared to those without parkin mutations.

CONCLUSIONS

Relatives of EOPD cases with compound heterozygous mutations and without diagnosed PD may have a higher risk of depression compared to relatives without parkin mutations. These findings support evidence of a genetic contribution to depression and may extend the phenotypic spectrum of parkin mutations to include non-motor manifestations that precede the development of PD.

Olfaction in Parkin heterozygotes and compound heterozygotes: the CORE-PD study

BACKGROUND

While Parkinson disease (PD) is consistently associated with impaired olfaction, one study reported better olfaction among Parkin mutation carriers than noncarriers. Whether olfaction differs between Parkin mutation heterozygotes and carriers of 2 Parkin mutations (compound heterozygotes) is unknown.

OBJECTIVE

To assess the relationship between Parkin genotype and olfaction in PD probands and their unaffected relatives.

METHODS

We administered the University of Pennsylvania Smell Identification Test (UPSIT) to 44 probands in the Consortium on Risk for Early-Onset Parkinson Disease study with PD onset ≤50 years (10 Parkin mutation heterozygotes, 9 compound heterozygotes, 25 noncarriers) and 80 of their family members (18 heterozygotes, 2 compound heterozygotes, 60 noncarriers). In the probands, linear regression was used to assess the association between UPSIT score (outcome) and Parkin genotype (predictor), adjusting for covariates. Among family members without PD, we compared UPSIT performance in heterozygotes vs noncarriers using generalized estimating equations, adjusting for family membership, age, gender, and smoking.

RESULTS

Among probands with PD, compound heterozygotes had higher UPSIT scores (31.9) than heterozygotes (20.1) or noncarriers (19.9) (p < 0.001). These differences persisted after adjustment for age, gender, disease duration, and smoking. Among relatives without PD, UPSIT performance was similar in heterozygotes (32.5) vs noncarriers (32.4), and better than in heterozygotes with PD (p = 0.001).

CONCLUSION

Olfaction is significantly reduced among Parkin mutation heterozygotes with PD but not among their heterozygous relatives without PD. Compound heterozygotes with PD have olfaction within the normal range. Further research is required to assess whether these findings reflect different neuropathology in Parkin mutation heterozygotes and compound heterozygotes.

Detection of Huntington's disease decades before diagnosis: the Predict-HD study

OBJECTIVE

The objective of the Predict-HD study is to use genetic, neurobiological and refined clinical markers to understand the early progression of Huntington's disease (HD), prior to the point of traditional diagnosis, in persons with a known gene mutation. Here we estimate the approximate onset and initial course of various measurable aspects of HD relative to the time of eventual diagnosis.

METHODS

We studied 438 participants who were positive for the HD gene mutation, but did not yet meet the diagnostic criteria for HD and had no functional decline. Predictability of baseline cognitive, motor, psychiatric and imaging measures was modelled non-linearly using estimated time until diagnosis (based on CAG repeat length and current age) as the predictor.

RESULTS

Estimated time to diagnosis was related to most clinical and neuroimaging markers. The patterns of association suggested the commencement of detectable changes one to two decades prior to the predicted time of clinical diagnosis. The patterns were highly robust and consistent, despite the varied types of markers and diverse measurement methodologies.

CONCLUSIONS

These findings from the Predict-HD study suggest the approximate time scale of measurable disease development, and suggest candidate disease markers for use in preventive HD trials.

Haplotypes and gene expression implicate the MAPT region for Parkinson disease: the GenePD Study

BACKGROUND

Microtubule-associated protein tau (MAPT) has been associated with several neurodegenerative disorders including forms of parkinsonism and Parkinson disease (PD). We evaluated the association of the MAPT region with PD in a large cohort of familial PD cases recruited by the GenePD Study. In addition, postmortem brain samples from patients with PD and neurologically normal controls were used to evaluate whether the expression of the 3-repeat and 4-repeat isoforms of MAPT, and neighboring genes Saitohin (STH) and KIAA1267, are altered in PD cerebellum.

METHODS

Twenty-one single-nucleotide polymorphisms (SNPs) in the region of MAPT on chromosome 17q21 were genotyped in the GenePD Study. Single SNPs and haplotypes, including the H1 haplotype, were evaluated for association to PD. Relative quantification of gene expression was performed using real-time RT-PCR.

RESULTS

After adjusting for multiple comparisons, SNP rs1800547 was significantly associated with PD affection. While the H1 haplotype was associated with a significantly increased risk for PD, a novel H1 subhaplotype was identified that predicted a greater increased risk for PD. The expression of 4-repeat MAPT, STH, and KIAA1267 was significantly increased in PD brains relative to controls. No difference in expression was observed for 3-repeat MAPT.

CONCLUSIONS

This study supports a role for MAPT in the pathogenesis of familial and idiopathic Parkinson disease (PD). Interestingly, the results of the gene expression studies suggest that other genes in the vicinity of MAPT, specifically STH and KIAA1267, may also have a role in PD and suggest complex effects for the genes in this region on PD risk.

Pediatric pancreatic trauma: predictors of nonoperative management failure and associated outcomes

BACKGROUND

Nonoperative management (NOM) is an accepted treatment of pediatric solid organ injuries and is typically successful. Blunt pancreatic trauma tends to require operative intervention more frequently. We sought to identify predictors of failure of NOM and compare the outcome of operative management against NOM.

METHODS

A retrospective analysis was performed from January 1993 to December 2002 of all children with blunt pancreatic injuries from the trauma registries of 7 designated level 1 pediatric trauma centers. Failure of NOM was defined as the need for intraabdominal operative intervention. Injuries were graded I to V, and ductal injury was defined as grades III to V. Parameters included mechanism of injury, injury severity score (ISS), organ grade, Glasgow Coma Scale score, and outcome. Data were analyzed by Fisher exact test and Mann-Whitney U test, with mean values +/- SD and significance of P < .05.

RESULTS

Pancreatic injuries were present in 173 (9.2%) of 1823 patients. Of these, 43 (26.0% [43/173]) required an operation. Valid morbidity data was obtained in 118 of 173 patients. ISS was significantly higher in all patients treated operatively. Patients with an injury of grade III to V failed NOM more frequently than all patients with pancreatic injury (P =.0169). Length of stay was longer, and the incidence of pseudocysts, drainage procedures, and pancreatitis was higher in NOM patients, although not significant.

CONCLUSIONS

Patients with pancreatic injuries had a NOM failure rate of 26.0%. ISS and injury grades III to V were predictors of NOM failure. Patients with pancreatic ductal injury require more aggressive management.

Interaction of normal and expanded CAG repeat sizes influences age at onset of Huntington disease

Huntington disease (HD) is a neurodegenerative disorder caused by the abnormal expansion of CAG repeats in the HD gene on chromosome 4p16.3. Past studies have shown that the size of expanded CAG repeat is inversely associated with age at onset (AO) of HD. It is not known whether the normal Huntington allele size influences the relation between the expanded repeat and AO of HD. Data collected from two independent cohorts were used to test the hypothesis that the unexpanded CAG repeat interacts with the expanded CAG repeat to influence AO of HD. In the New England Huntington Disease Center Without Walls (NEHD) cohort of 221 HD affected persons and in the HD-MAPS cohort of 533 HD affected persons, we found evidence supporting an interaction between the expanded and unexpanded CAG repeat sizes which influences AO of HD (P = 0.08 and 0.07, respectively). The association was statistically significant when both cohorts were combined (P = 0.012). The estimated heritability of the AO residual was 0.56 after adjustment for normal and expanded repeats and their interaction. An analysis of tertiles of repeats sizes revealed that the effect of the normal allele is seen among persons with large HD repeat sizes (47-83). These findings suggest that an increase in the size of the normal repeat may mitigate the expression of the disease among HD affected persons with large expanded CAG repeats.

Predictors of nursing home placement in Huntington disease

OBJECTIVE

To determine whether motor, behavioral, or psychiatric symptoms in Huntington disease (HD) predict skilled nursing facility (SNF) placement.

METHODS

Subjects were participants in the Huntington Study Group's Unified Huntington Disease Rating Scale Database (Rochester, NY) between January 1994 and September 1999. Specific motor, psychiatric, and behavioral variables in subjects residing at home and in SNF were analyzed using chi2 and Student's t-tests. For a subset of subjects for whom longitudinal data existed, a Cox proportional hazards model controlling for age, sex, and disease duration was used.

RESULTS

Among 4,809 subjects enrolled, 3,070 had clinically definite HD. Of these, 228 (7.4%) resided in SNF. The SNF residents' average age was 52 years, average disease duration was 8.6 years, and they were predominantly women (63%). The SNF residents had worse motor function (chorea, bradykinesia, gait abnormality, and imbalance, p < 0.0001); were more likely to have obsessions, compulsions, delusions, and auditory hallucinations; and had more aggressive, disruptive (p < 0.0001), and irritable behaviors (p = 0.0012). For 1,559 subjects, longitudinal data existed (average length of follow-up, 1.9 years), and 87 (5%) moved from home to SNF. In the Cox model, bradykinesia (HR 1.965, 95% CI 1.083 to 3.564), impaired gait (HR 3.004, 95% CI 1.353 to 6.668), and impaired tandem walking (HR 2.546, 95% CI 1.460 to 4.439) were predictive of SNF placement.

CONCLUSIONS

Institutionalized patients with HD are more motorically, psychiatrically, and behaviorally impaired than their counterparts living at home. However, motor variables alone predicted institutionalization. Treatment strategies that delay the progression of motor dysfunction in HD may postpone the need for institutionalization.

Fine mapping and genetic heterogeneity in the pure form of autosomal dominant familial spastic paraplegia

We evaluated seven families segregating pure, autosomal dominant familial spastic paraplegia (SPG) for linkage to four recently identified SPG loci on chromosomes 2q (1), 8q (2), 12q (3), and 19q (4). These families were previously shown to be unlinked to SPG loci on chromosomes 2p, 14q, and 15q. Two families demonstrated linkage to the new loci. One family (family 3) showed significant evidence for linkage to chromosome 12q, peaking at D12S1691 (maximum lod = 3.22). Haplotype analysis of family 3 did not identify any recombinants among affected individuals in the 12q candidate region. Family 5 yielded a peak lod score of 2.02 at marker D19S868 and excluded linkage to other known SPG loci. Haplotype analysis of family 5 revealed several cross-overs in affected individuals, thereby potentially narrowing the SPG12 candidate region to a 5-cM region between markers D19S868 and D19S220. Three of the families definitively excluded all four loci examined, providing evidence for further genetic heterogeneity of pure, autosomal dominant SPG. In conclusion, these data confirm the presence of SPG10 (chromosome 12), potentially reduce the minimum candidate region for SPG12 (chromosome 19q), and suggest there is at least one additional autosomal dominant SPG locus.

Linkage of familial amyotrophic lateral sclerosis with frontotemporal dementia to chromosome 9q21-q22

CONTEXT

Occasionally, 2 or more major neurodegenerative diseases arise simultaneously. An understanding of the genetic bases of combined disorders, such as amyotrophic lateral sclerosis (ALS) with frontotemporal dementia (FTD), will likely provide insight into mechanisms of these and related neurodegenerative diseases.

OBJECTIVE

To identify loci that contain genes whose defects cause ALS.

DESIGN

A genome-wide linkage analysis of 2 data sets from an ongoing study begun in the mid-1980s at 4 university research centers.

SUBJECTS

An initial subset of 16 families (549 people) potentially informative for genetic analysis, in which 2 or more individuals were diagnosed as having ALS, identified from a Boston data set of 400 families and 4 families potentially informative (244 people) subsequently identified from a Chicago data set of more than 300 families to test a hypothesis based on findings from the Boston families.

MAIN OUTCOME MEASURES

Linkage calculations assuming autosomal dominant inheritance with age-dependent penetrance (a parametric logarithm-of-odds [lod] score of 1.0 or greater required for further study of a potential locus); crossover analysis involving the ALS-FTD locus.

RESULTS

In a set of families in which persons develop both ALS and FTD or either ALS or FTD alone, a genetic locus that is linked to ALS with FTD located between markers D9S301 and D9S167 was identified on human chromosome 9q21-q22. Families with ALS alone did not show linkage to this locus. Crossover analysis indicates this region covers approximately 17 cM.

CONCLUSION

These data suggest that a defective gene located in the chromosome 9q21-q22 region may be linked to ALS with FTD. JAMA. 2000;284:1664-1669.

Hyperlipidemia and neuropathy

Detailed histories/physical examinations (n = 47) and nerve conduction studies (n = 34) were performed in a large kindred with congenital partial lipodystrophy (CPL) in an effort to evaluate the association of hyperlipidemia and neuropathy. CPL, in the absence of diabetes, did not predispose to either focal mononeuropathy or generalized polyneuropathy, and the likelihood of either did not correlate with the degree of cholesterol or triglyceride elevation. This study does not provide support for an association between neuropathy and hyperlipidemia.

Brain glyceraldehyde-3-phosphate dehydrogenase activity in human trinucleotide repeat disorders

BACKGROUND

Although the abnormal gene products responsible for several hereditary neurodegenerative disorders caused by repeat CAG trinucleotides have been identified, the mechanism by which the proteins containing the expanded polyglutamine domains cause cell death is unknown. The observation that several of the mutant proteins interact in vitro with the key glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) suggests that interaction between the different gene products and GAPDH might damage brain neurons.

OBJECTIVE

To measure the activity of GAPDH in postmortem brain of patients with CAG repeat disorders.

PATIENTS AND METHODS

Activity of GAPDH was measured in morphologically affected and unaffected brain areas of patients with 4 different CAG repeat disorders (Huntington disease, spinocerebellar ataxia 1 [SCA1], SCA2, and SCA3-Machado-Joseph disease), in brains of patients with Friedreich ataxia (a GAA repeat disorder) and Alzheimer disease, and in brains of matched control subjects.

RESULTS

Brain GAPDH activity was normal in all groups with the exception of a slight but statistically significant region-specific reduction in the patients with Huntington disease (caudate nucleus, -12%) and Alzheimer disease (temporal cortex, -19%).

CONCLUSION

The presence of the polyglutamine-containing proteins in CAG repeat disorders does not result in substantial irreversible inactivation or in increased activity of GAPDH in human brain.

Cognitive consequences of subcortical magnetic resonance imaging changes in Alzheimer's disease: comparison to small vessel ischemic vascular dementia

OBJECTIVE

The objective of this study was to compare psychometric profiles of Alzheimer's disease (AD) patients with subcortical magnetic resonance imaging (MRI) signal abnormalities to those of AD patients without such MRI findings (normal subcortical MRI) and to those of patients with ischemic vascular dementia (IVD) associated with small and primarily subcortical ischemic changes.

BACKGROUND

The cognitive significance of MRI white matter and other subcortical abnormalities in AD is unknown. Prior studies comparing AD patients with white matter changes on MRI have not included IVD patients with comparable MRI findings. If white matter/subcortical changes in AD reflect vascular abnormalities, they might be associated with cognitive profiles similar to those seen in subcortical IVD.

METHOD

We studied 15 AD patients with normal subcortical MRIs, 22 AD patients with subcortical MRI hyperintensities, and 18 IVD (NINCDS-ADRDA and NINDS-AIREN criteria) at the Alzheimer's Disease Research Center of the Baylor College of Medicine. IVD patients had predominantly small and subcortical signal abnormalities, and none had large cortical infarcts. AD patients had only nonspecific subcortical signal abnormalities with or without atrophy (atrophy was not analyzed). We compared the AD group with abnormal MRIs to the AD group with normal subcortical MRIs and the AD group to the IVD group using ANCOVA planned comparisons (dementia severity and education covaried).

RESULTS

AD patients with abnormal MRIs did not differ significantly from AD patients with normal subcortical MRIs on any of the neuropsychological measures. AD patients exhibited significantly better attention/concentration, visuospatial/visuoconstructional performance, letter fluency, motor programming, and simple motor speed than IVD patients as well as significantly worse delayed verbal recognition memory. Because MRI changes were generally more extensive in IVD, a subset of AD patients with abnormal subcortical MRIs was compared to a subset of IVD patients matched for degree of MRI signal abnormalities. These subsets of AD and IVD patients still showed distinctive neuropsychological profiles.

CONCLUSIONS

AD patients with or without MRI subcortical signal abnormalities have similar neuropsychological profiles, and they differ from IVD patients with comparable MRI changes. Although MRI signal abnormalities in AD patients who have no history or examination findings of cerebrovascular disease overlap with those seen in IVD patients, they do not seem to have the same cognitive significance. Periventricular hyperintensities (PVHs) and deep signal hyperintensities, especially those of a mild to moderate degree, may reflect a different pathophysiologic process in AD than in IVD and do not necessarily have cognitive consequences in AD patients.

Genome-wide search for asthma susceptibility loci in a founder population. The Collaborative Study on the Genetics of Asthma

Founder populations offer many advantages for mapping genetic traits, particularly complex traits that are likely to be genetically heterogeneous. To identify genes that influence asthma and asthma-associated phenotypes, we conducted a genome-wide screen in the Hutterites, a religious isolate of European ancestry. A primary sample of 361 individuals and a replication sample of 292 individuals were evaluated for asthma phenotypes according to a standardized protocol. A genome-wide screen has been completed using 292 autosomal and three X-Y pseudoautosomal markers. Using the semi-parametric likelihood ratio chi2 test and the transmission-disequilibrium test, we identified 12 markers in 10 regions that showed possible linkage to asthma or an associated phenotype (likelihood ratio P < 0.01). Markers in four regions (5q23-31, 12q15-24.1, 19q13 and 21q21) showed possible linkage in both the primary and replication samples and have also shown linkage to asthma phenotypes in other samples; two adjacent markers in one additional region (3p24.2-22) showing possible linkage is reported for the first time in the Hutterites. The results suggest that even in founder populations with a relatively small number of independent genomes, susceptibility alleles at many loci may influence asthma phenotypes and that these susceptibility alleles are likely to be common polymorphisms in the population.

Pediatric nonpowder firearm injuries: outcomes in an urban pediatric setting

BACKGROUND

Approximately 32 000 nonpowder firearm injuries are reported annually with more than 60% occurring in the pediatric population. Case reports of serious and fatal injuries have been described; however, no large inclusive series have been published. We reviewed an 11-year experience of an urban pediatric emergency department to evaluate the circumstances, spectrum of injuries, and outcomes attributable to nonpowder firearms.

METHODS

A retrospective, descriptive case series of all children 18 years of age or younger evaluated at an urban children's hospital from January 1983 through December 1994 were eligible for study. Patients were identified using a computerized database, the National Electronic Injury Surveillance System, and the trauma registry in the department of surgery. Medical records were reviewed to collect demographic information, circumstances of injury, anatomic site and type of injury, treatment, and outcomes for nonpowder firearm injuries.

RESULTS

One hundred eighty patients were identified, and a complete data set was available for 166 (92%). The mean age was 12 +/- 3.7 years, 24% of children were <10 years old, and 71% of the children were male. Three patients returned with a second nonpowder firearm injury during the study period. Forty-nine percent of injuries were intentional and 44% of all injuries occurred during the summer and early fall months. The most common sites of injury were the extremity/buttocks (39%), head and neck (33%), thorax (13%), and eye (8%). Serious injuries included intracranial hemorrhage, cardiac right ventricle laceration, hyphema, and abdominal visceral injury (liver laceration, pancreatic laceration, intestinal perforation). The majority of wounds required local wound care, and the children (74%) were discharged from the emergency department. Of the patients admitted to the hospital (27%), 45% required operative intervention. There were no deaths. Seven percent (12/166) of patients sustained some functional deficit with 42% (5/12) the result of an ocular injury.

CONCLUSION

The majority of nonpowder firearm injuries are minor; however, the potential for serious injury should not be underestimated. Minor injuries can be treated with local wound care and tetanus prophylaxis, and patients can be discharged from the emergency department. Education of parents and children to the potential risks associated with these weapons is essential. Stricter regulations regarding ownership of nonpowder firearms and mandatory safety instruction should be considered.

Somatic mosaicism in the central nervous system in spinocerebellar ataxia type 1 and Machado-Joseph disease

Spinocerebellar ataxia type 1 and Machado-Joseph disease are two autosomal dominant cerebellar ataxias caused by expansions of unstable CAG repeats in the coding region of the causative genes. The selectivity of cell death and the resulting characteristic neuropathological features in each of these diseases are not explained by the gene expression patterns. Since the repeat size correlates with age at onset and severity of these diseases, somatic mosaicism, the result of mitotic instability of the CAG repeat, could be the basis for specificity of neurodegeneration; brain structures with larger expanded repeats would be more severely affected. To study the association between neuropathological changes and somatic mosaicism of the CAG repeat size in the central nervous system of patients with these two ataxias, we determined the size of the (CAG)n expansion in 20 different regions of the brain, brainstem, cerebellum, and spinal cord from 3 patients with spinocerebellar ataxia type 1 and 3 with Machado-Joseph disease; these regions were selected for their differential neuropathological involvement in the two disorders. We observed a considerable homogeneity of repeat size ranges in all but 1 of the 20 regions examined: The cerebellar cortex showed slightly smaller (CAG)n tracts in all specimens from both groups of patients. Our results suggest that the pattern of repeat size mosaicism, similar in spinocerebellar ataxia type 1 and Machado-Joseph disease, reflects the developmental pathways and cell composition of different central nervous system regions and is not the cause of selective cell death in these disorders.

X-linked mental retardation with thin habitus, osteoporosis, and kyphoscoliosis: linkage to Xp21.3-p22.12

We reevaluated a family previously described as having nonspecific X-linked mental retardation (XLMR) by Snyder and Robinson [1969: Clin Pediatr 8:669-674] (MIM 309583). Clinical and DNA studies were conducted on 17 relatives, including 6 males with mild-to-moderate mental retardation, 3 carrier females, and 8 normal males. In contrast to the normal appearance and minimal clinical findings reported 22 years ago, affected males were found to have a characteristic set of clinical findings. These developed gradually over the first 2 decades, and included thin body build with diminished muscle mass, osteoporosis and kyphoscoliosis, slight facial asymmetry with a prominent lower lip, nasal speech, high narrow or cleft plate, and long great toes. Carrier females were clinically normal. Multipoint linkage analysis indicated linkage to markers distal to the 3' end of DMD (DXS41 and DXS989), with a maximal lod score of 4.7. On the basis of these findings, this entity is redefined as XLMR syndrome.

Fibronectin synthesis by aorta explants from rabbits fed high cholesterol diets

Fibronectin synthesis was studied in aorta explants in culture from rabbits fed a high fat-high cholesterol diet. [3H]Mannose and [14C]leucine were used to label oligosaccharide side chains and the protein core, respectively. The synthesis was followed by monitoring immunoprecipitable fibronectin from the culture medium using polyclonal goat anti-rabbit fibronectin antibody. Synthesis of fibronectin increased by [14C]leucine (81%) and [3H]mannose (29%) incorporation over controls. On gel filtration, fibronectin synthesized by controls and cholesterol-fed rabbit resolved into four fractions. Pulse-chase experiment with [3H]glucosamine or [3H]leucine showed that fibronectin secreted by the aorta explants from rabbits fed high fat-high cholesterol diets incorporated an increased amount of radioactivity. Pulsing with [3H]mannose showed decreased incorporation of the label. During the chase period, the rate of secretion of fibronectin into the media by the hypercholesterolemic rabbit aorta explants was increased. The fibronectin that bound to the gelatin or heparin columns from cholesterol-fed rabbit aorta media had lower levels of [3H]mannose incorporated into the glycoprotein than the control. These results indicate that there is an alteration in carbohydrate composition of the fibronectin synthesized by the aorta explants from rabbits fed a high cholesterol diet. High fat-cholesterol intake could play a causative role in matrix dysfunction during atherogenesis by altering glycoprotein synthesis.