Citations

Sudden unexpected death in epilepsy is the sudden, unexplained, unexpected death of an individual with epilepsy in which postmortem examination does not reveal an anatomic or toxicologic cause of death. Patients with congenital long QT syndrome and catecholaminergic polymorphic ventricular tachycardia have been frequently initially diagnosed with epilepsy. A cardiac channel molecular autopsy of the common long QT syndrome and catecholaminergic polymorphic ventricular tachycardia-susceptibility genes was performed on an archived necropsy specimen from an 8-year-old victim of sudden unexpected death in epilepsy. A novel, sporadic missense mutation in exon 104 of the RYR2-encoded ryanodine receptor/calcium release channel (c. 14806G>A, p.Gly4936Arg) was discovered. This mutation was absent in >600 reference alleles including both parents, involved a highly conserved amino acid, and localized to a key structure-function domain. To our knowledge, this is the first postmortem molecular diagnosis of catecholaminergic polymorphic ventricular tachycardia in a patient with sudden unexpected death in epilepsy.

We executed a genome-wide association scan for age-related macular degeneration (AMD) in 2,157 cases and 1,150 controls. Our results validate AMD susceptibility loci near CFH ( P < 10 −75 ), ARMS2 ( P < 10 −59 ), C2/CFB ( P < 10 −20 ), C3 ( P < 10 −9 ), and CFI ( P < 10 −6 ). We compared our top findings with the Tufts/Massachusetts General Hospital genome-wide association study of advanced AMD (821 cases, 1,709 controls) and genotyped 30 promising markers in additional individuals (up to 7,749 cases and 4,625 controls). With these data, we identified a susceptibility locus near TIMP3 (overall P = 1.1 × 10 −11 ), a metalloproteinase involved in degradation of the extracellular matrix and previously implicated in early-onset maculopathy. In addition, our data revealed strong association signals with alleles at two loci ( LIPC , P = 1.3 × 10 −7 ; CETP , P = 7.4 × 10 −7 ) that were previously associated with high-density lipoprotein cholesterol (HDL-c) levels in blood. Consistent with the hypothesis that HDL metabolism is associated with AMD pathogenesis, we also observed association with AMD of HDL-c—associated alleles near LPL ( P = 3.0 × 10 −3 ) and ABCA1 ( P = 5.6 × 10 −4 ). Multilocus analysis including all susceptibility loci showed that 329 of 331 individuals (99%) with the highest-risk genotypes were cases, and 85% of these had advanced AMD. Our studies extend the catalog of AMD associated loci, help identify individuals at high risk of disease, and provide clues about underlying cellular pathways that should eventually lead to new therapies.

ABSTRACT The SLOMYCO Sensititre panel and the custom JustOne strip (both from TREK Diagnostic Systems, Cleveland, OH) were evaluated for susceptibility testing of Mycobacterium avium complex isolates against clarithromycin. Seventy-one archived and prospectively collected isolates were tested using both the SLOMYCO panel and the JustOne strip, and the results were compared to those obtained using the BACTEC 460 (BD, Sparks, MD) radiometric method and a broth microdilution reference method. Results obtained by the SLOMYCO panel and the JustOne strip agreed with the BACTEC 460 method for 64/71 isolates (90%). Similarly, concordance with the broth microdilution method was 40/43 isolates (93%) for both test systems. The effect of the source medium on inoculum preparation was evaluated, and there were no differences noted in MICs, regardless of whether the inoculum was prepared from isolates grown in Middlebrook 7H9 medium, on Middlebrook 7H10 agar, or in VersaTREK broth culture bottles (Trek Diagnostics). Clarithromycin susceptibility testing of MAC using the SLOMYCO panel and the JustOne strip methods is easy to set up and simple to read and is readily incorporate into the clinical laboratory. These systems offer advantages over the BACTEC 460 system including the lack of a need for radioactive substrates, sharps, or costly instrumentation.

This descriptive population study of 307 public high school students, ages 15 to 17 years, was performed to establish reference ranges for orthostatic changes in heart rate and blood pressure in adolescents, and to identify influential variables. Noninvasive measurements of blood pressure and heart rate were obtained. Reference ranges for orthostatic heart rate change in this population at 2 minutes were –2 to +41 beats per minute and at 5 minutes were –1 to +48 beats per minute. Orthostatic blood pressure changes were within the adult range for 98% of adolescents tested. One-third of participants experienced orthostatic symptoms during testing. In conclusion, this study shows that orthostatic symptoms and large orthostatic heart rate changes occur in adolescents. This suggests that the current orthostatic heart rate criterion aiding the diagnosis of adult orthostatic intolerance syndromes is likely not appropriate for adolescents and should be reevaluated.

Abstract True calcium absorption can only be measured by the time-consuming and expensive metabolic balance method and is not predicted well by measuring the fractional absorption (FA) of radiocalcium from a fixed calcium carrier. We describe here a 1 day method for measuring the actual fraction of calcium absorbed from the habitual diet (true fractional calcium absorption, TFCA) using stable isotopes of calcium. Oral and intravenous isotopes were administered with each of the three daily meals, and then the ratio of the two isotopes in the urine was measured by mass spectroscopy. In 12 subjects, TFCA determined from stable Ca correlated well with TFCA measured by the balance method (r = 0.71, P &lt; 0.01), and the mean values were not different (0.26 and 0.26). In contrast, no significant correlation was found between FA and TFCA. The weak relationship between FA and TFCA underscores the importance of tracing dietary calcium rather than a fixed calcium carrier in tests of calcium absorption. Using the new method, TFCA was inversely related to dietary calcium (r = −0.45, P &lt; 0.05), demonstrating that it could detect physiological changes in calcium absorption. Thus, this test has two important advantages: (1) it provides a simple way to measure TFCA and true fractional calcium absorption (the product of TFCA and dietary calcium), the physiologically relevant variables, and (2) because there is no radiation exposure, the test can be used in pregnant women and children, the isotopes can be prepared in advance, and several isotopes can be used simultaneously.

Abstract We studied the mechanism of impaired calcium absorption with aging in 51 healthy women whose ages ranged from 26 to 88 years. Serum concentrations of 1,25-dihydroxyvitamin D [1,25-(OH)2D, mean of four measurements per subject] increased with age by 22% (P &lt; 0.05) but, by split-point analysis, plateaued or decreased slightly after age 65. In a subset of 20 subjects, [3H]1,25-(OH)2D3 kinetic analysis showed that this increase with age resulted from both increased production and decreased metabolic clearance of 1,25-(OH)2D. Despite the increase in serum 1,25-(OH)2D concentration, true calcium absorption did not change with age. The expected inverse correlation between true fractional calcium absorption and dietary calcium intake, however, was easily demonstrated (r = 0.66, P &lt; 0.001). Serum intact parathyroid hormone (PTH) increased with age by 35% (P &lt; 0.02) and serum bone gla protein (BGP, osteocalcin) increased by 47% (P &lt; 0.001); the increases in serum PTH and serum BGP were directly correlated (r = 0.32, P &lt; 0.05). The data are consistent with the following hypothetical model: (1) intestinal resistance to 1,25-(OH)2D action accounts for the increase in serum 1,25-(OH)2D concentrations with aging with no change in true calcium absorption; (2) this results in a compensatory increase in PTH secretion and in 1,25-(OH)2D production that prevents true calcium absorption from decreasing; (3) the previously described defect in 25-hydroxyvitamin D (25-OHD) 1α-hydroxylase activity in aging animals and humans acccounts for the leveling off in serum 1,25-(OH)2D concentration after age 65 years; and (4) the secondary hyperparathyroidism leads to increased bone turnover and thus contributes to age-related bone loss.

Abstract Mutations in one of the two genes encoding type I procollagen (COL1A1 and COL1A2) are frequently the cause of osteogenesis imperfecta (OI), a disorder characterized by brittle bones. Here we tested whether patients with low bone density also have mutations in these genes. The 26 patients studied had no apparent metabolic bone disease, but most had a positive family history of osteopenia or osteoporosis. Although a diagnosis of OI was considered by the clinician in some cases, the clinical criteria for OI were not satisfied. Our strategy for mutation analysis consisted of PCR amplification of cDNA made to fibroblast mRNA using primers specific for the coding regions of COL1A1 and COL1A2. The PCR products were then sequenced directly with primers located within each PCR product. We found that 3 of 26 patients had mutations that altered the encoded amino acid. One mutation, at position α2(I)-661 has been reported (Spotila et al. 1991 Proc Natl Acad Sci USA PNAS 88: 5423). The other 2 patients, who were not related to each other, had a mutation that altered the proline codon at α1(I)-27 to alanine. This mutation was not found in 81 normal individuals or in 37 additional osteopenic individuals. However, its effect on the biologic function of type I collagen, as well as its role in osteopenia, is uncertain. In addition to the two mutations, we found a polymorphism in codon α2(I)-459. Although this polymorphism involved an amino acid substitution, it was present with equal frequency in the patient and the normal population. By analyzing this and previously reported neutral sequence variants in the COL1A2 gene, we determined that all patients expressed both alleles of the COL1A2 gene. The 12 patients who were heterozygous for a COL1A1 neutral sequence variant also expressed both alleles. Here we present all PCR primer and sequencing primer information. The results suggest that surveying a larger group of similarly selected individuals may reveal additional mutations in the COL1A1 or COL1A2 genes.

Purpose. Oral mucositis is a serious problem that affects a significant number of hematopoietic cell transplant (HCT) patients. There are many gaps in management, and evidence-based guidelines do not provide consistent recommendations. The purpose of this pilot study was to develop a mucositis oral care protocol for the prevention and management of mucositis in the HCT patient and to evaluate the clinical impact of its implementation. Methods. After receipt of Institutional Review Board approval, all patients admitted to the Hematology—Oncology service for high-dose chemotherapy followed by an autologous or allogeneic HCT were eligible for the study. As part of a change in practice, a new mucositis protocol consisting of a specific oral care regimen was instituted for prevention and treatment of mucositis. Assessment of mucositis began upon admission to the hospital and the patient was evaluated using a mucositis grading scale on a daily basis by the physician and nursing staff. The new mucositis protocol was a part of the HCT service admission orders for each patient. The group of patients treated according to the new mucositis protocol were compared with a retrospective control group consisting of patients who had undergone management of oral mucositis under the previous standard of care. The primary endpoints were to evaluate incidence, severity, and duration of oral mucositis. Secondary endpoints included days requiring narcotics; days of parenteral nutrition, febrile neutropenia, antimicrobial therapy, and length of hospital stay. Results. There were 13 patients enrolled in the control group and 12 patients in the new protocol group. The new protocol resulted in a decreased incidence (100% vs. 75%) and duration (19.2 vs. 8.3 days) of mucositis. Days of maximum grade one and three mucositis were decreased by 56%, and 70%, respectively. Days of maximum grade two mucositis, however increased by 22%. The days of narcotic use were reduced by 19% in the new protocol group (15.8 vs. 12.8 days). All patients in the new protocol group required parenteral nutrition, but days of use were reduced by 41% (17 vs. 10.2 days). The incidence of infection measured by days of febrile neutropenia and antimicrobial therapy were reduced by 35% (10.2 vs. 6.5 days) and 33% (17 vs. 11.4 days). Finally, the overall length of hospital stay was reduced by 7 days (30 vs. 23 days). Conclusion. Implementation of a standardized oral care protocol for mucositis management resulted in a decreased incidence, duration and severity of mucositis, and also reduced the global negative impact of mucositis. Future studies may further evaluate the global impact by adjusting for confounding factors. J Oncol Pharm Practice (2010) 16: 195—204.