A cerebellar ataxia locus identified by DNA pooling to search for linkage disequilibrium in an isolated population from the Cayman Islands

A non-progressive recessive cerebellar ataxia was identified in a highly inbred Cayman island population. Cayman cerebellar ataxia is characterized by marked psychomotor retardation, and prominent cerebellar dysfunction manifested by nystagmus, intention tremor, dysarthric speech, and an ataxic gait. In this study, we identify linkage to chromosome 19p 13.3 using pooled DNA samples of affected individuals from an isolated population as PCR template for a genome wide screen with short tandem repeat markers. Our data demonstrate that the DNA pooling approach to identify disease gene loci is feasible using individuals from isolated populations in which kindred relationships are highly complex and exact relationships between all affected individuals are not known. Genetic fine mapping demonstrates that the genetic disease interval is approximately 9 cM, but contained within a small physical region. The existence of multiple individuals that are recombinant with flanking markers indicates that the disease interval can be further narrowed with additional markers.      

Evaluation of the red cell storage lesion after irradiation in filtered packed red cell units

Packed red cell units (n = 10) were filtered and divided equally. One-half unit from each donor was irradiated (x) (3500 cGy). On Days 0, 14, 28, and 42, ATP, K+, Na+, lactate dehydrogenase (LDH), plasma-free hemoglobin (PFH), and pH were determined. The reduction in ATP was greater in the irradiated than the nonirradiated (y) units by Day 42 (mean x-y: -70, p = 0.0005). The increase in K+ was greater in the irradiated than nonirradiated units on Days 14, 28, and 42 (mean x-y: 17-20, p = 0.0001). Decrease in pH and increases in LDH and PFH were significant (p less than 0.05) on Day 42 only. K+ increases added only 1.7 to 2.0 mmol per unit, a difference felt to be clinically insignificant. The changes noted in ATP, pH, LDH, and PFH are significant but minimal on Day 42 and imply that viability changes would also be minimal. These biochemical data support the storage of irradiated units for at least 28 days.     

Unilateral hypertrophic osteoarthropathy in a patient with an infected axillary-axillary bypass graft

Hypertrophic osteoarthropathy (HO) is a specific clinicoradiologic entity, the most common cause of which is the presence of pulmonary lesions. Eight cases of aortic graft infection and aortoenteric fistulae in association with HO have been recognized. A case of an infected axillary-axillary graft presenting as unilateral HO of the upper limb is reported, and its unusual features are used to postulate a mechanism underlying HO.     

Cognitive neuroscience of delusions in aging

Assessments and clinical understanding of late-onset delusions in the elderly are inconsistent and often incomplete. In this review, we consider the prevalence, neurobehavioral features, and neuroanatomic correlations of delusions in elderly persons – those with documented cognitive decline and those with no evidence of cognitive decline. Both groups exhibit a common phenotype: delusions are either of persecution or of misidentification. Late-onset delusions show a nearly complete absence of the grandiose, mystical, or erotomanic content typical of early onset psychoses. Absent also from both elderly populations are formal thought disorders, thought insertions, and delusions of external control. Neuroimaging and behavioral studies suggest a frontotemporal localization of delusions in the elderly, with right hemispheric lateralization in delusional misidentification and left lateralization in delusions of persecution. We propose that delusions in the elderly reflect a common neuroanatomic and functional phenotype, and we discuss applications of our proposal to diagnosis and treatment.     

Dummies and the sudden infant death syndrome

The association between dummy use and sudden infant death syndrome (SIDS) was investigated in 485 deaths due to SIDS in the postneonatal age group and compared with 1800 control infants. Parental interviews were completed in 87% of subjects. The prevalence of dummy use in New Zealand is low and varies within New Zealand. Dummy use in the two week period before death was less in cases of SIDS than in the last two weeks for controls (odds ratio (OR) 0.76, 95% confidence interval (CI) 0.57 to 1.02). Use of a dummy in the last sleep for cases of SIDS or in the nominated sleep for controls was significantly less in cases than controls (OR 0.44, 95% CI 0.26 to 0.73). The OR changed very little after controlling for a wide range of potential confounders. It is concluded that dummy use may protect against SIDS, but this observation needs to be repeated before dummies can be recommended for this purpose. If dummy sucking is protective then it is one of several factors that may explain the higher mortality from SIDS in New Zealand than in other countries, and may also explain in part the regional variation within New Zealand.     

Predictive ability of a predischarge hour-specific serum bilirubin for subsequent significant hyperbilirubinemia in healthy term and near-term newborns

OBJECTIVE: To assess the predictive ability of a universal predischarge serum bilirubin measurement to screen for risk of subsequent significant hyperbilirubinemia in the direct Coombs negative healthy term and near-term newborn during the first postnatal week. METHODS: Total serum bilirubin (TSB) levels were obtained at the time of the routine metabolic screen in all term and near-term newborns cared for in the Pennsylvania Hospital Well Baby Nursery (n = 13 003). Postnatal age (in hours) at the time of TSB measurement was recorded. A percentile-based bilirubin nomogram for the first week was constructed from hour-specific predischarge and postdischarge TSB values of newborns (n = 2840; median BW = 3230 g and median gestational age = 39 weeks) who met classification criteria for healthy newborns (excluding those with a positive direct Coombs test or those requiring phototherapy before age 60 hours) and who were enrolled in a hospital supervised home or outpatient follow-up program. The accuracy of the predischarge TSB as a predictor of subsequent degree of hyperbilirubinemia was determined. RESULTS: The study patients in the nomogram were racially diverse. Nearly 60% were breastfed. Predischarge, 6.1% of the study population (172/2840) had TSB values in the high-risk zone (>/=95th percentile) at 18 to 72 hours; of these, 39.5% (68/172) remained in that zone (likelihood ratio [LR] = 14.08, sensitivity = 54%; specificity = 96.2%, probability = 39.5%). Predischarge, 32.1% of the population (912/2840) had TSB values in the intermediate-risk zone. In a clinically significant minority of these newborns (58/912 or 6.4%), the postdischarge TSB moved into the high-risk zone (LR of this move: 3.2 from the upper-intermediate zone and.48 from the lower-intermediate risk zone). The predischarge TSB in 61.8% of the newborns (1756/2840) was in the low-risk zone (<40th percentile) and there was no measurable risk for significant hyperbilirubinemia (LR = 0, sensitivity = 100%; specificity = 64.7%; probability = 0%). CONCLUSIONS: An hour-specific TSB before hospital discharge can predict which newborn is at high, intermediate or low risk for developing clinically significant hyperbilirubinemia (specifically defined as TSB levels >/=95th percentile for age in hours). Risk designation and subsequent increases or decreases of in TSB can be easily monitored on an hour-specific percentile based predictive bilirubin nomogram. A predischarge TSB measured as a universal policy would facilitate targeted intervention and follow-up in a safe, cost-effective manner. In conjunction with bilirubin practice parameter of the American Academy of Pediatrics, it could reduce the potential risk for bilirubin-induced neurologic dysfunction.