McArdle disease: a clinical review

METHODS

The clinical phenotype of 45 genetically confirmed McArdle patients is described.

RESULTS

In the majority of patients (84%), the onset of symptoms was from early childhood but diagnosis was frequently delayed until after 30 years of age. Not all patients could recognise a second wind although it was always seen with exercise assessment. A history of myoglobinuria was not universal and episodes of acute renal failure had occurred in a minority (11%). The condition does not appear to adversely affect pregnancy and childbirth. Clinical examination was normal in most patients, muscle hypertrophy was present in 24% and mild muscle wasting and weakness were seen only in patients over 40 years of age and was limited to shoulder girdle and axial muscles. The serum creatine kinase was elevated in all but one pregnant patient. Screening for the mutations pArg50X (R50X) and pGly205Ser (G205S) showed at least one mutated allele in 96% of Caucasian British patients, with an allele frequency of 77% for pArg50X in this population. A 12 min walking test to evaluate patients is described.

CONCLUSION

The results demonstrated a wide spectrum of severity with the range of distance walked (195-1980 m); the mean distance walked was 512 m, suggesting significant functional impairment in most patients.

Radiation myelopathy after 36 Gy in 12 fractions palliative chest radiotherapy for squamous cell cancer of the lung: case report and review of published studies

A 55 year old man was treated with 36 Gy in 12 fractions palliative chest irradiation for squamous cell carcinoma of the lung. This was followed by 3 cycles of cisplatin and gemcitabine. Five months later he developed clinical and imaging findings consistent with radiation myelopathy. The maximum spinal cord dose was 38.9 Gy. The possible contributions of portal imaging and gemcitabine are discussed and the literature reviewed.

Genetic variants cis-regulating Xrn2 expression contribute to the risk of spontaneous lung tumor

Gene expression variation is an important mechanism underlying susceptibility to complex disease. In comparison with tobacco-related lung carcinogenesis, lung cancer in nonsmokers may involve important and etiologically distinct causal pathways. In this study, we conducted a genome-wide association study on spontaneous lung tumor incidence in inbred mice and identified a major susceptibility locus on mouse chromosome 2 (rs27328255, P=6.68 x 10(-7)). We then evaluated the correlations of polymorphisms with the transcription of positional candidate genes in normal lungs. Single-nucleotide polymorphism rs27328255 was consistently and strongly associated (P=7.42 x 10(-9)) in cis with transcript levels of Xrn2. We further showed that Xrn2 promotes proliferation and inhibits squamous differentiation in human lung epithelial cells and polymorphisms in human homolog XRN2 are associated with human lung cancer (rs2025811, P=1.90 x 10(-3), OR=1.20). We conclude that genetic variants regulating Xrn2 expression in cis are determinants of spontaneous lung tumor susceptibility in mice and have genetic equivalents in lung cancer susceptibility in human beings. Identifying Xrn2 as a major candidate for spontaneous lung cancer has important implications for the diagnosis and treatment of lung cancer as well as delineation of the mechanisms underlying the genesis of lung cancer in nonsmokers.

Association and interaction analyses of eight genes under asthma linkage peaks

BACKGROUND

Linkage studies have implicated the 2q33, 9p21, 11q13 and 20q13 regions in the regulation of allergic disease. The aim of this study was to test genetic variants in candidate genes from these regions for association with specific asthma traits.

METHODS

Ninety-five single nucleotide polymorphisms (SNP) located in eight genes (CD28, CTLA4, ICOS, ADAM23, ADAMTSL1, MS4A2, CDH26 and HRH3) were genotyped in >5000 individuals from Australian (n = 1162), Dutch (n = 99) and Danish (n = 303) families. Traits tested included doctor-diagnosed asthma, atopy, airway obstruction, total serum immunoglobulin (Ig) E levels and eosinophilia. Association was tested using both multivariate and univariate methods, with gene-wide thresholds for significance determined through simulation. Gene-by-gene and gene-by-environment analyses were also performed.

RESULTS

There was no overall evidence for association with seven of the eight genes tested when considering all genetic variation assayed in each gene. The exception was MS4A2 on chromosome 11q13, which showed weak evidence for association with IgE (gene-wide P < 0.05, rs502581). There were no significant gene-by-gene or gene-by-environment interaction effects after accounting for the number of tests performed.

CONCLUSIONS

The individual variants genotyped in the 2q33, 9p21 and 20q13 regions do not explain a large fraction of the variation in the quantitative traits tested or have a major impact on asthma or atopy risk. Our results are consistent with a weak effect of MS4A2 polymorphisms on the variation of total IgE levels.

The impact of a quadrivalent human papillomavirus (types 6, 11, 16, 18) virus-like particle vaccine in European women aged 16 to 24

BACKGROUND

Quadrivalent human papillomavirus (HPV types 6/11/16/18) L1 VLP vaccine is highly effective in preventing HPV 6/11/16/18-related cervical and external genital disease. Herein, we evaluated the impact of the quadrivalent HPV 6/11/16/18 L1 VLP vaccine on prevention of HPV-associated cervico-genital lesions in a broad population of sexually active European women.

METHODS

Female subjects (N = 9265) aged 16-24 with four or fewer lifetime sexual partners were enrolled and randomized to quadrivalent HPV vaccine or placebo. Subjects underwent cervicovaginal sampling for HPV DNA detection. Papanicolaou testing and anti-HPV 6/11/16/18 serology testing was also performed.

RESULTS

Vaccine efficacy against lesions representing immediate cervical cancer precursors (cervical intraepithelial neoplasia grade 2/3 or adenocarcinoma in situ) related to HPV 6/11/16/18 in the per-protocol population was 100.0%[95% confidence interval (95% CI), 89.8-100.0]. Efficacy against external genital lesions (vulvar or vaginal intraepithelial neoplasia, condyloma, vulvar or vaginal cancer) related to vaccine HPV types in the per-protocol European population was 99.0% (95% CI, 94.4-100.0).

CONCLUSION

These data demonstrate that quadrivalent HPV 6/11/16/18 vaccination programs in 16- to 24-year-old European women can be beneficial. NCT0009252, NCT00092534, NCT00092495.

Dual targeting of Src and ER prevents acquired antihormone resistance in breast cancer cells

Acquired resistance to endocrine therapies presents a major obstacle to the successful treatment of breast cancer patients. Previously, we have shown that acquisition of resistance to tamoxifen in breast cancer cells is accompanied by an elevation in Src kinase activity which promotes an aggressive, invasive phenotype in vitro. Here, we have explored the potential therapeutic effects of combining Src inhibition with anti-oestrogen treatment on the development of endocrine insensitivity in breast cancer cells. Treatment of MCF7 and T47D cells with tamoxifen alone resulted in an initial growth inhibitory phase followed by the eventual development of tamoxifen resistance together with an elevation of Src kinase activity, which was central to their increased invasive capacity. Chronic exposure of both cell types to the Src inhibitor, AZD0530, as a monotherapy resulted in outgrowth of AZD0530-resistant cells, in which Src kinase activity remained suppressed as did their in vitro invasive nature. Treatment of both MCF7 and T47D cells with AZD0530 in combination with tamoxifen resulted in a reduction of Src activity together with inhibition of focal adhesion kinase phosphorylation and a complete abrogation of their in vitro invasive behaviour. Furthermore, combination therapy significantly suppressed expression of cyclinD1 and c-myc and prevented cell proliferation and the subsequent emergence of a resistant phenotype, with total cell loss occurring by 12 weeks. These data demonstrate that pharmacological targeting of Src kinase, in conjunction with antihormone therapies, effectively prevents antihormone resistance in breast cancer cells in vitro and suggests a potential novel therapeutic benefit of Src kinase inhibitors clinically.

Clinicopathologic features of breast disease in Jamaica: findings of the Jamaican Breast Disease Study, 2000-2002

OBJECTIVE

To describe the clinicopathologic profile of breast disease in Jamaica.

METHODS

The Jamaican Breast Disease Study is an ongoing prospective, multidisciplinary investigation of breast disease at the University Hospital of the West Indies (UHWI). The initial phase was a prevalence survey comprising all consenting patients referred to the Surgical Outpatient Department (SOPD) UHWI, for breast disease. Demographic, clinical, radiologic and pathologic information were recorded for each patient and the data for the first three years (2000-2002) were analyzed.

RESULTS

A total of 1189 patients was enrolled for the study period (28.8% of all new SOPD patients). The age range was 10 to 93 years (mean/SD = 36.5 +/- 16.4 years) with a female : male ratio of 14:1. Most patients (67.8%) presented with a palpable lump and the clinical diagnosis was benign in the majority (70.4%) of patients. Fibroadenoma was the most common benign histologic result (39.4% of all biopsies) followed by non-proliferative (fibrocystic) disease (19.3% of all biopsies). Proliferative disease without atypia, complex fibroadenoma and atypical ductal hyperplasia accounted for 6.9%, 2.6% and 0.4% of biopsies respectively. Overall, 23.4% of biopsies showed malignant histology (10.8% patients); invasive ductal carcinoma accounted for the majority of these cases (69.5%).

CONCLUSIONS

The majority of patients with breast disease in Jamaica are young women with clinically benign disease. There was a low prevalence of clinically significant premalignant disease. This is the first study to prospectively describe the clinicopathologic features of breast disease in Jamaica and supports the need for advocating breast cancer screening to facilitate detection of significant premalignant disease and early stages of breast cancer.

Penetrating neck trauma and the aberrant subclavian artery

Vascular injuries from penetrating trauma to the base of the neck are accompanied by significant morbidity and potential mortality. These injuries require several diagnostic adjuncts in order to facilitate early diagnosis and appropriate treatment. Herein reported is the case of a patient who sustained penetrating injury to the thoracic inlet but had a fortuitous anomaly that prevented vascular injury and its attendant complications.

An economic evaluation of three physiotherapy treatments for non-specific neck disorders alongside a randomized trial

OBJECTIVES

Cost-effectiveness and cost-utility analyses were conducted to compare advice and exercise plus manual therapy (MT) and advice and exercise plus pulsed shortwave diathermy (PSWD) with advice and exercise alone (A&E) in the treatment of non-specific neck disorders by experienced physiotherapists.

METHODS

Between July 2000 and June 2002, 350 participants with neck disorders from 15 physiotherapy departments were randomized to: A&E (n = 115); MT (n = 114) and PSWD (n = 121). Outcome and resource-use data were collected using physiotherapist case report forms and participant self-complete questionnaires. Outcome measures were the Northwick Park Neck Pain Questionnaire (NPQ) and EuroQoL EQ-5D [used to derive quality-adjusted-life-year (QALY) utility scores]. Two economic viewpoints were considered (health care and societal). Cost-effectiveness acceptability curves were used to assess the probabilities of the interventions being cost-effective at different willingness-to-pay threshold values.

RESULTS

Mean improvement in NPQ at 6 months was 11.5 in the A&E group, 10.2 in the MT group and 10.3 in the PSWD group; mean QALY scores were 0.362, 0.342 and 0.360, respectively. Mean health care costs were pound sterling105, pound sterling119 and pound sterling123 in the A&E, MT and PSWD groups, respectively. Mean societal costs were pound sterling373, pound sterling303 and pound sterling 338 in each group, respectively. Depending on the viewpoint and the outcome measure, A&E or MT were most likely to be the cost-effective interventions. PSWD was consistently the least cost-effective intervention.

CONCLUSIONS

The cost-effective intervention is likely to be A&E or MT, depending on the economic perspective and preferred outcome, but not PSWD.

Effectiveness of the dual specific Src/Abl kinase inhibitor AZD0530 in combination with tamoxifen in preventing acquired anti-estrogen resistance in breast cancer cells

14054

Background: AZD0530 is a novel, orally potent, once-daily, highly selective and dual-specific Src/Abl kinase inhibitor with potential for activity in a wide range of tumors. In the context of breast cancer, where tamoxifen resistance presents a major problem, Src inhibition may be a particularly valuable therapeutic strategy since we have previously observed that elevated Src kinase activity accompanies anti-estrogen resistance in vitro, promoting an aggressive cell phenotype. Here, we have explored the potential therapeutic effects of Src inhibition with AZD0530, alone and in combination with tamoxifen, on the acquisition of endocrine resistance in breast cancer cells. Methods: MCF7 and T47D breast cancer cells were exposed to tamoxifen (10–7 M), AZD0530 (1 μM), or both agents in combination for a minimum of 10 months with passaging as necessary, or until total cell death occurred. Cells were assayed at monthly intervals for intracellular signaling pathway activity (Western Blotting) and in vitro invasive capacity (Matrigel invasion assays). Apoptosis and proliferation were assessed by ELISA and Ki67 staining, respectively. Changes in c-Myc and cyclin-D1 were measured with RT-PCR. Results: Treatment of cells with tamoxifen alone ultimately resulted in acquired resistance, elevated Src kinase activity, and a Src- dependent increase in invasive capacity. Chronic exposure to AZD0530 alone resulted in outgrowth of AZD0530 resistant cells, in which Src kinase activity remained suppressed as did their in vitro invasiveness. Treatment of MCF7 and T47D cells with AZD0530 and tamoxifen combined resulted in a reduction of Src, FAK, and Akt activity, inhibition of c-Myc gene expression, and complete abrogation of their in vitro invasive behavior. Furthermore, combination treatment completely prevented cell proliferation and the subsequent emergence of a resistant phenotype, with a total loss of cells by 12 weeks. Conclusions: Inhibition of Src kinase with AZD0530, when used in conjunction with anti-estrogen therapies, effectively prevents acquired resistance in breast cancer cells in vitro suggesting a potential novel therapeutic benefit of Src kinase inhibitors clinically.

No significant financial relationships to disclose.

Identification of transmembrane proteins as potential prognostic markers and therapeutic targets in breast cancer by a screen for signal sequence encoding transcripts

This study demonstrates, through a combination of stringent screening methods and thorough validation, that it is possible to identify transmembrane proteins preferentially expressed in primary breast tumour cells. mRNA was extracted from tumour cells isolated from invasive breast cancers and it was then subtracted against normal breast tissue mRNA prior to the generation of a signal sequence-trap library. Screening of the library identified 31 positive clones encoding 12 cell-surface and 12 secreted proteins. The expression of a subset of transmembrane genes was then interrogated using a high-throughput method (tissue microarray) coupled with cutting-edge in situ techniques in a large cohort of patients who had undergone uniform adjuvant chemotherapy. Expression of CD98 heavy chain (CD98HC) and low-level expression of the insulin-like growth factor 2 receptor/mannose-6-phosphate receptor (IGF2R/M6PR) correlated with poor patient prognosis in the whole cohort. Expression of bradykinin receptor B1 (BDKRB1) and testis enhanced gene transcript (TEGT) correlated with good prognosis in woman with oestrogen receptor (ER)-negative breast tumours. These results indicate that this combined approach of isolating primary tumour cells, generating a library to specifically isolate signal-sequence-containing transcripts, and in situ hybridization on tissue microarrays successfully identified novel prognostic markers (BDKRB1, CD98hc, and TEGT) and potential transmembrane therapeutic targets (CD98hc) in breast cancer.

Buckle-related complications following surgical repair of retinal dialysis

AIM

To describe buckle-related complications following surgical repair of retinal dialysis.

METHODS

A retrospective study of 28 consecutive cryobuckle procedures for retinal detachments secondary to retinal dialysis is reported, with particular attention directed towards postoperative complications relating to the buckle. Stata 8 statistical software and Fisher's exact test were used to analyse the data.

RESULTS

Of the 28 cases, anatomic success was achieved with a single procedure in 26 cases (92.9%). Postoperative complications were seen in 20 cases (71.4%), with complications attributable to the buckle noted in 19 (67.9%). Buckle-related complications included exposure (7; 25%), strabismus (5; 17.9%), and infection (3; 10.7%). Surgical removal of the buckle was indicated in 13 cases (46.4%), typically within the first 6 postoperative months. Of these, the retina remained flat following removal of buckle in 12 cases (92.3%), whereas the retina redetached in one case (7.7%).

CONCLUSION

Cryotherapy with explant is an effective primary procedure for the surgical repair of retinal detachment secondary to retinal dialysis. However, there is a high rate of postoperative complications relating to the buckle following this surgical approach, although the buckle can be safely removed without compromising the anatomic success of the primary surgery in the vast majority of cases.