The effect of calpain 3 deficiency on the pattern of muscle degeneration in the earliest stages of LGMD2A

Limb girdle muscular dystrophy type 2A (LGMD2A) is caused by mutations in the calpain 3 gene. In a large family affected by LGMD2A with four severely affected members, three additional asymptomatic relatives had very high serum creatine kinase concentrations. All were homozygous for the R110X mutation and showed a total absence of calpain 3 in the muscle. Histological analysis of muscle in these three rare preclinical cases showed a consistent but unusual pattern, with isolated fascicles of degenerating fibres in an almost normal muscle. This pattern was also seen in one patient with early stage LGMD2A who had a P82L missense mutation and a partial deficiency of calpain 3 in the muscle, but was not seen in early stage patients affected by other forms of LGMD. These findings suggest that a peculiar pattern of focal degeneration occurs in calpainopathy, independently of the type of mutation or the amount of calpain 3 in the muscle.     

A longitudinal study of mental health consumer/survivor initiatives: Part V–Outcomes at 3‐year follow‐up

The objective of this study was to evaluate the impacts of participation in mental health Consumer/Survivor Initiatives (CSIs), organizations run by and for people with mental illness. A nonequivalent comparison group design was used to compare three groups of participants: (a) those who were continually active in CSIs over a 36‐month period (n = 25); (b) those who had been active in CSIs at 9‐ and 18‐month follow‐up periods, but who were no longer active at 36 months (n = 35); and (c) a comparison group of participants who were never active in CSIs (n = 42). Data were gathered at baseline, 9‐, 18‐, and 36‐month follow‐ups. The three groups were comparable at baseline on a wide range of demographic variables, self‐reported psychiatric diagnosis, service use, and outcome measures. At 36 months, the continually active participants scored significantly higher than the other two groups of participants on community integration, quality of life (daily living activities), and instrumental role involvement, and significantly lower on symptom distress. No differences between the groups were found on other outcome measures. Improvements in 36‐month outcomes for people with mental illness who participated in CSIs suggest the potential value of these peer support organizations. Further research is needed to determine the replicability of these positive findings. © 2007 Wiley Periodicals, Inc. J Comm Psychol 35: 655–665, 2007.     

Molecular pathology of well-differentiated thyroid carcinomas

The newly discovered molecular features of well-differentiated thyroid carcinomas derived from follicular cells are reviewed, within the frame of the 2004 WHO classification of thyroid tumours, under the following headings: “Follicular carcinoma”, “Papillary carcinoma”, “Follicular variant of papillary carcinoma” and “Hürthle cell tumours”. A particular emphasis is put on the meaning of PAX8–PPARγ rearrangements, RAS and BRAF mutations, and deletions and mutations of mitochondrial genes and of nuclear genes encoding for mitochondrial enzymes, for thyroid tumorigenesis.     

Expression of retinoblastoma protein in human growth hormone-secreting pituitary adenomas

The retinoblastoma gene (RB1) is a tumor-suppressor gene in chromosomal region 13q14.2. Its role in the pathogenesis of pituitary tumors has not been fully clarified. Some studies have shown that losses in this chromosomal region are related to aggressive tumor behavior, although the retinoblastoma protein (pRB) is still expressed. Conversely, lack of expression of pRB was observed in one fourth of GH-secreting pituitary adenomas (GH-tumors). In order to further study the expression of pRB in GH-tumors, we evaluated this protein in 49 tumors from patients with acromegaly (20 noninvasive, 25 invasive, and 4 with no information) and 8 normal pituitaries using immunohistochemistry (IHC). Nuclear staining for pRB ranged from 0 to 90% (median 40%) in the tumors and from 40 to 80% (median 58%) in normal pituitaries. In 10 tumors (20% of total) the adenomatous cells were negative (5 cases) or had very low labeling (5 cases) for pRB. Sixty three percent (31/49) of the tumors showed staining in 10–80% of the cells and in 16% (8/49) of the cases >80% of the adenomatous cells were positive for pRB. The expression of pRB was not different in invasive and noninvasive tumors. In conclusion, pRB is underexpressed in a subgroup of GH-tumors, and this may represent an early event in the pathogenesis of this tumor subtype.     

New microsatellite multiplex PCR for Candida albicans strain typing reveals microevolutionary changes

Five new microsatellite loci were described and characterized for use as molecular markers for the identification and genetic differentiation of Candida albicans strains. Following the typing of 72 unrelated clinical isolates, the analysis revealed that they were all polymorphic, presenting from 5 to 30 alleles and 8 to 46 different genotypes. The discriminatory power obtained by combining the information generated by three microsatellites used in a multiplex PCR amplification strategy was 0.99, the highest ever reported. The multiplex PCR was later used to test a total of 114 C. albicans strains, including multiple isolates from the same patient collected from different body locations and along episodes of vulvovaginal infections. Three different scenarios for strain relatedness were identified: (i) different isolates that were revealed to be the same strain, (ii) isolates that were the same strain but that apparently underwent a process of microevolution, and (iii) isolates that corresponded to different strains. Analysis of the microevolutionary changes between isolates from recurrent infections indicated that the genotype alterations observed could be the result of events that lead to the loss of heterozygosity (LOH). In one case of recurrent infection, LOH was observed at the CAI locus, and this could have been related to exposure to fluconazole, since such strains were exposed to this antifungal during treatment. The analysis of microsatellites by a multiplex PCR strategy was found to be a highly efficient tool for the rapid and accurate differentiation of C. albicans strains and adequate for the identification of fine microevolutionary events that could be related to strain microevolution in response to environmental stress conditions.     

Discordant immunologic and virologic responses to highly active antiretroviral therapy are associated with increased mortality and poor adherence to therapy

OBJECTIVE: To examine the independent association of discordant virologic and immunologic responses to highly active antiretroviral therapy (HAART) with mortality. METHODS: A population-based study of 1527 treatment-naive individuals initiating HAART used Cox proportional hazards modeling to determine the independent association of treatment response at 3 to 9 months with nonaccidental mortality. Logistic regression was used to examine associations with discordant responses. RESULTS: Viral load (VL)/CD4 discordant responses were seen in 235 (15.4%) of subjects, and VL/CD4 responses were seen in 179 (11.7%) of subjects. In adjusted Cox regression models, discordant responses were found to be independently associated with an increased risk of mortality (VL/CD4: relative hazard [RH] = 1.87, 95% confidence interval [CI]: 1.15 to 3.04; VL/CD4: RH = 2.47, 95% CI: 1.54 to 3.95). VL/CD4 discordance was found to be associated with increasing age, baseline HIV RNA load <100,000 copies/mL, baseline CD4 counts <50 cells/muL, the use of lamivudine (3TC)/zidovudine (ZDV), and poor adherence to therapy. VL/CD4 discordance was associated with younger age; injection drug use; baseline HIV RNA load >100,000 copies/mL; the use of 3TC/ZDV, didanosine (ddI)/3TC, or ddI/stavudine; and poor adherence to therapy. CONCLUSION: Discordant responses are independently associated with an increased risk of mortality and are, in turn, associated with poor adherence to therapy.     

Haptic selective attention by foot and by hand

Nonvisual perceptions of a wielded object's spatial properties are based on the quantities expressing the object's mass distribution, quantities that are invariant during the wielding. The mechanoreceptors underlying the kind of haptic perception involved in wielding – referred to as effortful, kinesthetic, or dynamic touch – are those embedded in the muscles, tendons, and ligaments. The present experiment's focus was the selectivity of this muscle-based form of haptic perception. For an occluded rod grasped by the hand at some intermediate position along its length, participants can attend to and report selectively the rod's full length, its partial lengths (fore or aft of the hand), and the position of the grip. The present experiment evaluated whether participants could similarly attend selectively when wielding by foot. For a given rod attached to and wielded by foot or attached to (i.e. grasped) and wielded by hand, participants reported (by magnitude production) the rod's whole length or fractional length leftward of the point of attachment. On measures of mean perceived length, accuracy, and reliability, the degree of differentiation of partial from full extent achieved by means of the foot matched that achieved by means of the hand. Despite their neural, anatomical, and experiential differences, the lower and upper limbs seem to abide by the same principles of selective muscle-based perception and seem to express this perceptual function with equal facility.     

Multilocus sequence typing of methicillin-resistant Staphylococcus aureus from an area of low endemicity by real-time PCR

A protocol for multilocus sequence typing (MLST) of methicillin-resistant Staphylococcus aureus (MRSA) was adapted to real-time LightCycler System PCR for efficient and rapid amplification of seven housekeeping genes in the same PCR run and real-time detection of the products. The method was evaluated on a representative and well-characterized collection of clinical MRSA isolates (n = 57) obtained from an area of low endemicity. Twenty sequence types (STs) and nine clonal complexes were identified. Combining STs and the staphylococcal cassette chromosome mec (SCCmec) type identified 27 different genotypes, and type IV SCCmec was present in 11 different STs. The presence of the Panton Valentine leukocidin (PVL) genes was found in isolates of four different STs. Eleven different STs were found among the community-acquired as well as among the hospital-acquired MRSA. The genetic heterogeneity was also denoted by pulsed-field gel electrophoresis analysis that showed 24 different pulsotypes among the 57 MRSA isolates. The presence of more than one different type of SCCmec in the same ST indicates that the MRSA clones have arisen at several occasions in the same genetic background by independent acquisition of SCCmec into methicillin-sensitive strains. This circumstance shows the importance of combining MLST data with SCCmec-typing results when investigating the origins of MRSA.     

Canine X-linked severe combined immunodeficiency

Our laboratory has identified and characterized an X-linked severe combined immunodeficiency (XSCID) in dogs that is due to mutations in the common gamma (γc) subunit of the interleukin-2 (IL2), IL4, IL7, IL9, and IL 15 receptors. Canine XSCID, unlike genetically engineered γc-deficient mice, has a clinical and immunologic phenotype virtually identical to human XSCID. It appears that speciesspecific differences exist in the role of the γc and its associated cytokines in mice compared to their role in humans and dogs, suggesting γc-deficient dogs may be a more relevant model for studing the role of the γc in humans. We are utilizing this model for a variety of studies to address:

1. Fundamental questions concerning the role of the γc in cytokine regulation and lymphocyte development.
2. The pathogenesis of XSCID.
3. Strategies for improving bone marrow transplantation outcome.
4. Development and evaluation of strateies for gene therapy.
5. Human hematopoietic stem cell development.

     

The value of deletion analysis for carrier detection in Duchenne muscular dystrophy (DMD)

We performed genetic analysis for carrier detection for several at-risk females in a four-generation Duchenne muscular dystrophy (DMD) pedigree using deletion analysis. We demonstrated that dosage analysis is a suitable alternative method to determine the carrier status of female relatives of DMD patients shown to have a deletion within the DMD gene. Subsequently, we diagnosed an affected male fetus for an at-risk female shown to be a DMD carrier by deletion analysis. The usefulness of deletion and linkage analysis are compared. In this family, linkage analysis was complicated by the unavailability of key family members, two recombination events and by previously undisclosed nonpaternity. We found that dosage analysis was more efficient than linkage for carrier evaluation in this family.