Declining immune function in children and adolescents with hemophilia and HIV infection: effects on neuropsychological performance. Hemophilia Growth and Development Study

OBJECTIVE: To determine whether declines in immune functioning are associated with changes in neuropsychological performance in children and adolescents with hemophilia who are infected with the human immunodeficiency virus (HIV). METHODS: Participants were 333 males with hemophilia, ages 6-19 years at entry. A baseline and four annual neuropsychological evaluations were given. A longitudinal growth curves analysis of data was performed to detect changes associated with declining immune function. The cohort was stratified into four groups: (1) HIV- (n = 126); (2) HIV+, average of first two and last two CD4 counts > or = 200, (n = 106; High CD4 group); (3) HIV+, average first two counts > or = 200, average last two counts < 200 (n = 41; CD4 Drop group); and (4) HIV+, average first two and last two counts < 200 (n = 60; Low CD4 group). RESULTS: There were significant differences among the four groups over time in nonverbal intelligence, perceptual/performance skills, nonverbal memory, academic achievement, and language. The Low CD4 group consistently showed the greatest decrement in performance. On measures showing a practice effect for repeated measurements, the Low CD4 group participants' scores remained stable over time, suggesting opposing effects of practice and HIV-related declines. Lowered academic performance relative to IQ was found in all groups. CONCLUSIONS: Declines in neuropsychological functioning are directly related to declines in immune functioning in HIV+ children, adolescents, and young adults with hemophilia. Hemophilia itself may be a risk factor for academic underachievement.     

Ancient Human Bone Microstructure in Medieval England: Comparisons between Two Socio‐Economic Groups

Understanding the links between bone microstructure and human lifestyle is critical for clinical and anthropological research into skeletal growth and adaptation. The present study is the first to report correspondence between socio‐economic status and variation in bone microstructure in ancient humans. Products of femoral cortical remodeling were assessed using histological methods in a large human medieval sample (N = 450) which represented two distinct socio‐economic groups. Osteonal parameters were recorded in posterior midshaft femoral sections from adult males (N = 233) and females (N = 217). Using univariate and multivariate statistics, intact, fragmentary, and osteon population densities, Haversian canal area and diameter, and osteon area were compared between the two groups, accounting for sex, age, and estimated femoral robusticity. The size of osteons and their Haversian canals, as well as osteon density, varied significantly between the socio‐economic groups, although minor inconsistencies were observed in females. Variation in microstructure was consistent with historical textual evidence that describes differences in mechanical loading and nutrition between the two groups. Results demonstrate that aspects of ancient human lifestyle can be inferred from bone microstructure. Anat Rec, 299:42–59, 2016. © 2015 Wiley Periodicals, Inc.     

Sensitive and specific assay for the simultaneous detection of <Emphasis Type="Italic">Mycoplasma genitalium</Emphasis> and macrolide resistance-associated mutations

Patients infected by Mycoplasma genitalium are often treated empirically with the macrolide azithromycin. Macrolide resistance is becoming quite common; empirical treatment is compromised. Sequencing was initially used to detected azithromycin resistance-associated mutations. As this was laborious, qPCRs have been developed for their detection. In the present study, we describe a fast, sensitive, and specific qPCR assay that enables routine testing of M. genitalium and macrolide resistance-associated mutations in a single assay. M. genitalium positive clinical samples were used to compare (i) the commonly used MgPa assay for the detection of M. genitalium infections (MgPa qPCR), (ii) a combined 23S rRNA gene PCR/sequencing assay (Mg23S qPCR/Sequencing) to identify macrolide resistance-associated mutations, and (iii) our newly developed probe-based melt curve qPCR for simultaneous detection of M. genitalium and macrolide resistance-associated mutations (Macrolide-R/MG ELITe MGB Kit, Elitech Bothel USA in short Mg Macrolide^R qPCR). Specificity of the qPCR was tested using urogenital samples that were tested positive for a range of other micro-organisms. M. genitalium was detected in 196/236 (83.1%) samples by the MgPa qPCR, versus 172/236 (72.9%) by the combined Mg23S qPCR/Sequencing, and 202/236 (85.6%) by the Mg Macrolide^R qPCR. The Mg Macrolide^R qPCR showed high concordance to the Mg23S qPCR/Sequencing assay (201 vs 202 could be genotyped, respectively) for the detection of the macrolide resistant mutations. None of the other urogenital pathogens were tested positive in the Mg Macrolide^R qPCR, indicating specificity. The Mg Macrolide^R qPCR is fast, sensitive, specific, and can easily be implemented in the routine diagnostics.     

White matter tract signatures of the progressive aphasias

The primary progressive aphasias (PPA) are a heterogeneous group of language-led neurodegenerative diseases resulting from large-scale brain network degeneration. White matter (WM) pathways bind networks together, and might therefore hold information about PPA pathogenesis. Here we used diffusion tensor imaging and tract-based spatial statistics to compare WM tract changes between PPA syndromes and with respect to Alzheimer's disease and healthy controls in 33 patients with PPA (13 nonfluent/agrammatic PPA); 10 logopenic variant PPA; and 10 semantic variant PPA. Nonfluent/agrammatic PPA was associated with predominantly left-sided and anterior tract alterations including uncinate fasciculus (UF) and subcortical projections; semantic variant PPA with bilateral alterations in inferior longitudinal fasciculus and UF; and logopenic variant PPA with bilateral but predominantly left-sided alterations in inferior longitudinal fasciculus, UF, superior longitudinal fasciculus, and subcortical projections. Tract alterations were more extensive than gray matter alterations, and the extent of alteration across tracts and PPA syndromes varied between diffusivity metrics. These WM signatures of PPA syndromes illustrate the selective vulnerability of brain language networks in these diseases and might have some pathologic specificity.     

Is multiple SNP testing in BRCA2 and BRCA1 female carriers ready for use in clinical practice? Results from a large Genetic Centre in the UK

BRCA1 and BRCA2 are major breast cancer susceptibility genes. Nineteen single nucleotide polymorphisms (SNPs) at 18 loci have been associated with breast cancer. We aimed to determine whether these predict breast cancer incidence in women with BRCA1/BRCA2 mutations. BRCA1/2 mutation carriers identified through the Manchester genetics centre between 1996 and 2011 were included. Using published odds ratios (OR) and risk allele frequencies, we calculated an overall breast cancer risk SNP score (OBRS) for each woman. The relationship between OBRS and age at breast cancer onset was investigated using the Cox proportional hazards model, and predictive ability assessed using Harrell's C concordance statistic. In BRCA1 mutation carriers we found no association between OBRS and age at breast cancer onset: OR for the lowest risk quintile compared to the highest was 1.20 (95% CI 0.82–1.75, Harrell's C = 0.54), but in BRCA2 mutation carriers the association was significant (OR for the lowest risk quintile relative to the highest was 0.47 (95% CI 0.33–0.69, Harrell's C = 0.59). The 18 validated breast cancer SNPs differentiate breast cancer risks between women with BRCA2 mutations, but not BRCA1. It may now be appropriate to use these SNPs to help women with BRCA2 mutations make maximally informed decisions about management options.     

Hoechst staining and exposure to UV laser during flow cytometric sorting does not affect the frequency of detected endogenous DNA nicks in abnormal and normal human spermatozoa

Controlling the sex of offspring by the separation of X and Y chromosome-bearing spermatozoa using flow cytometry has been reported as a clinical technique aiding prevention of X-linked diseases. Although this technique has resulted in several hundred normal births in animals and at least one human birth, there is still concern over its genetic safety due to the involvement of two potentially mutagenic agents: UV light and the fluorochrome dye, Hoechst 33342 (H33342). Human spermatozoa, particularly those considered abnormal, may be more likely to suffer DNA damage following exposure to mutagenic agents, compared with other mammalian species. The stability of normal fresh and decondensed human spermatozoa were examined after exposure to a range of levels of UV and H33342 staining, using an assay that detects endogenous nicks in the DNA of spermatozoa. The stability of abnormal and normal, fresh and frozen-thawed human spermatozoa was examined following UV laser, H33342 staining and flow cytometry treatments utilizing the same assay. There was an increase in the presence of endogenous nicks when spermatozoa were decondensed compared with fresh spermatozoa. There was no increase in the incidence of nicks in any group of spermatozoa after UV and fluorochrome exposure compared with controls without exposure.      

Modulation of disease severity of dystrophic epidermolysis bullosa by a splice site mutation in combination with a missense mutation in the COL7A1 gene

Dystrophic epidermolysis bullosa (EBD) is a clinically heterogeneous skin disorder, characterized by abnormal anchoring fibrils (AF) and loss of dermal-epidermal adherence. EBD has been linked to the COL7A1 gene at chromosome 3p21 which encodes collagen VII, the major component of the AF. Here we investigated two unrelated EBD families with different clinical phenotypes and novel combinations of recessive and dominant COL7A1 mutations. Both families shared the same recessive heterozygous 14 bp deletion at the exon-intron 115 boundary of the COL7A1 gene. The deletion caused in-frame skipping of exon 115 and the elimination of 29 amino acid residues from the pro-alpha1(VII) polypeptide chain. As a result, procollagen VII was not converted to collagen VII and the C-terminal NC-2 propeptide which is normally removed from the procollagen VII prior to formation of the anchoring fibrils was retained in the skin. All affected individuals also carried missense mutations in exon 73 of COL7A1 which lead to different glycine- to-arginine substitutions in the triple-helical domain of collagen VII. Combination of the deletion mutation with a G2009R substitution resulted in a mild phenotype. In contrast, combination of the deletion with a G2043R substitution led to a severe phenotype. The G2043R substitution was a de novo mutation which alone caused a mild phenotype. Thus, different combinations of dominant and recessive COL7A1 mutations can modulate disease activity of EBD and alter the clinical presentation of the patients.      

Osteoporosis assessment strategies for male nursing home residents

OBJECTIVES: Twenty-five to thirty percent of hip fractures occur in men, and nursing home residents have a 5-10-fold greater fracture risk than community-dwellers. Osteoporosis prevalence in men in long-term care, however, is poorly defined. Our objectives were to determine the prevalence of osteoporosis, as assessed by peripheral bone mineral density (BMD), in a group of institutionalized veterans, and to determine how many men with low BMD had received a prior diagnosis of osteoporosis. METHODS: Subjects were residents in a 740-bed skilled nursing facility (78% men). Male residents (n = 103) competent to give informed consent underwent bilateral calcaneal and forearm BMD by dual-energy X-ray absorptiometry (DXA). Prior osteoporosis documentation was sought in medical records. RESULTS: Twenty percent of veterans (95% confidence interval (CI) 12-28%) exhibited calcaneal osteoporosis (T-score < -2.5), and 62% (CI 52-72%) were osteoporotic at the forearm. Forearm and calcaneal BMD were correlated (r = 0.678, P < 0.001). BMD of the left and right forearm, and of left and right calcaneus, were highly correlated (r = 0.880, P < 0.001 and r = 0.931, P < 0.001, respectively). Documentation of osteoporosis existed for one of 20 men with calcaneal osteoporosis and four of 59 men with forearm osteoporosis. CONCLUSIONS: Osteoporosis was prevalent but poorly documented in institutionalized veterans. Discordance in T-scores between forearm and heel was similar to that reported in other studies. The broad range of T-scores among subjects suggests that peripheral BMD measurement may be useful for clinical fracture risk stratification. Correlation among skeletal sites indicates that measuring a single site may be practical.     

Vertebral Osteoporosis and Trabecular Bone Quality

Vertebral fractures due to osteoporosis commonly occur under non-traumatic loading conditions. This problem affects more than 1 in 3 women and 1 in 10 men over a lifetime. Measurement of bone mineral density (BMD) has traditionally been used as a method for diagnosis of vertebral osteoporosis. However, this method does not fully account for the influence of changes in the trabecular bone quality, such as micro-architecture, tissue properties and levels of microdamage, on the strength of the vertebra. Studies have shown that deterioration of the vertebral trabecular architecture results in a more anisotropic structure which has a greater susceptibility to fracture. Transverse trabeculae are preferentially thinned and perforated while the remaining vertical trabeculae maintain their thickness. Such a structure is likely to be more susceptible to buckling under normal compression loads and has a decreased ability to withstand unusual or off-axis loads. Changes in tissue material mechanical properties and levels of microdamage due to osteoporosis may also compromise the fracture resistance of vertebral trabecular bone. New diagnostic techniques are required which will account for the influence of these changes in bone quality. This paper reviews the influence of the trabecular architecture, tissue properties and microdamage on fracture risk for vertebral osteoporosis. The morphological characteristics of normal and osteoporotic architectures are compared and their potential influence on the strength of the vertebra is examined. The limitations of current diagnostic methods for osteoporosis are identified and areas for future research are outlined.