A common missense mutation in the adhalin gene in three unrelated Brazilian families with a relatively mild form of autosomal recessive limb-girdle muscular dystrophy

Autosomal recessive limb-girdle muscular dystrophies (AR LGMD) represent a heterogeneous group of diseases with a wide spectrum of clinical variability, classified phenotypically into two main groups, the most severe forms (Duchenne-like muscular dystrophy, DLMD, or severe childhood autosomal recessive muscular dystrophy, SCARMD) and the milder forms. Four genes causing AR LGMD have been mapped: the 15q (LGMD2a), the 2p (LGMD2b), the 13q locus (LGMD2c) and the adhalin gene on chromosome 17q (LGMD2d). In the present report we have performed linkage analysis with 17q markers in three mild AR LGMD and in four DLMD families with adhalin deficiency and unlinked to 2p, 15q or 13q genes. Linkage was observed only among the mild cases. Patients from these three 17q-linked families showed near or total deficiency of adhalin in muscle biopsies. An identical missense mutation was identified in all three 17q-linked unrelated families. These results indicate that AR LGMD with a mild phenotype is caused by mutations in the adhalin gene. In addition, they demonstrate that there is at least one other locus for DLMD associated with adhalin deficiency.

Germline BRCA1 mutations and loss of the wild-type allele in tumors from families with early onset breast and ovarian cancer

The BRCA1 gene on human chromosome 17q21 is responsible for an autosomal dominant syndrome of inherited early onset breast/ovarian cancer. It is estimated that women harboring a germline BRCA1 mutation incur an 85% lifetime risk of breast cancer and a greatly elevated risk of ovarian cancer. The BRCA1 gene has recently been isolated and mutations have been found in the germline of affected individuals in linked families. Previous studies of loss of heterozygosity (LOH) in breast tumors have been carried out on sporadic tumors derived from individuals without known linkage to BRCA1 and on tumors from linked families. Loss of large regions of chromosome 17 has been observed, but these LOH events could not be unequivocally ascribed to BRCA1. We have studied 28 breast and 6 ovarian tumors from families with strong evidence for linkage between breast cancer and genetic markers flanking BRCA1. These tumors were examined for LOH using genetic markers flanking and within BRCA1, including THRA1, D17S856, EDH17B1, EDH17B2, and D17S183. Forty-six percent (16/34) of tumors exhibit LOH which includes BRCA1. In 8 of 16 tumors the parental origin of the deleted allele could be determined by evaluation of haplotypes of associated family members; in 100% of these cases, the wild-type allele was lost. In some of these families germline mutations in BRCA1 have been determined; analyses of tumors with LOH at BRCA1 have revealed that only the disease-related allele of BRCA1 was present. These data strongly support the hypothesis that BRCA1 is a tumor suppressor gene.

The effect of suramin on healing adult rodent dermal wounds

Scarring, leading to impaired function, growth and appearance, is a major problem following many forms of surgery. Fetal wounds, unlike those in the adult, are characterised by a reduced growth factor profile and the absence of scar tissue (Whitby & Ferguson, 1991 a, b). The antiparasitic drug, suramin (a heparin analogue) inhibits binding of various growth factors (e.g. PDGF, bFGF, TGF-beta, EGF, IGF-I, IGF-II) to their receptors in vitro. These growth factors play key roles in wound healing. We attempted to manipulate experimentally their effectiveness in healing adult rat dermal incisional wounds by injecting suramin into the wound margins and comparing the resultant healing with an unmanipulated control wound in the same animal. Immunohistochemical staining demonstrated that, on d 7 and 14 postwounding, the numbers of monocytes/macrophages and blood vessels are markedly increased in suramin treated wounds compared with controls. Extracellular matrix deposition is lower, although very compact in organisation, lacking the usual honeycombed appearance of normal skin. These effects are widespread, being present not only in the wound area, but also in the surrounding tissue. No difference was detected at 70 d postwounding between the scars of suramin-treated and unmanipulated control wounds in the same animals. All such effects are increased slightly through the concentration range of 0.04-40 mg/kg suramin, with no significant change as concentrations greater than 40 mg/kg are applied. This suggests that suramin has marked effects on the early stages of wound healing, which plateau at 40 mg/kg concentration, but has no effect on scar formation.

Early diagnosis of Lassa fever by reverse transcription-PCR

We developed a method based on a coupled reverse transcription-PCR (RT-PCR) for the detection of Lassa virus using primers specific for regions of the S RNA segment which are well conserved between isolates from Sierra Leone, Liberia, and Nigeria. The specificity of the assay was confirmed by Southern blotting with a chemiluminescent probe. The assay was able to detect 1 to 10 copies of a plasmid or an RNA transcript containing the target sequence. There was complete concordance between RT-PCR and virus culture for the detection of Lassa virus in a set of 29 positive and 32 negative serum samples obtained on admission to the hospital from patients suspected of having Lassa fever in Sierra Leone. Specificity was confirmed by the failure of amplification of specific products from serum samples collected from 129 healthy blood donors in Sierra Leone or from tissue culture supernatants from cells infected with related arenaviruses (Mopeia, lymphocytic choriomeningitis, Tacaribe, and Pichinde viruses). Sequential serum samples from 29 hospitalized patients confirmed to have Lassa fever were tested by RT-PCR and for Lassa virus-specific antibodies by indirect immunofluorescence (IF). RT-PCR detected virus RNA in 79% of the patients at the time of admission, comparing favorably with IF, which detected antibodies in only 21% of the patients. Lassa virus RNA was detected by RT-PCR in all 29 patients by the third day of admission, whereas antibody was detectable by IF in only 52% of the patients. These results point to an important role for RT-PCR in the management of suspected cases of Lassa fever.

European Society of Mastology Consensus Conference on breast cancer screening: report of the evaluation committee

On 4 February 1993, the European Society of Mastology (EUSOMA) convened a meeting of experts in Paris to evaluate the current evidence on the value and hazards of breast cancer screening. The Committee consisted of individuals from different countries throughout Europe and from different disciplines. We summarise here the deliberations and conclusions of the Committee.

Investigating changes in awareness about cutaneous malignant melanoma in Britain using the Omnibus Survey

Awareness about cutaneous malignant melanoma and sun protection was investigated in a national sample of 3961 adults. Awareness about malignant melanoma seems to have increased in England since the mid-1980s but it is lower in men, the under 25s, the elderly, those without a partner and the poorer socioeconomic groups. As mortality rates for melanoma are higher in elderly men than other age-sex groups, the possibility for improved awareness and prevention needs to be explored further within this group. Most people in the survey knew about sun protection. Further primary prevention initiatives should be monitored, using markers for behaviour such as the incidence of sunburn, as the potential benefits of a reduced incidence of skin cancer might not be seen for up to 20 years.

Prevention of hepatitis B infection: a survey of surgeons and interventional cardiologists

Hepatitis B immunization and the use of protective measures against blood contamination were assessed in a group of clinicians associated with invasive procedures. A self-administered confidential questionnaire was sent to 140 surgeons and interventional cardiologists, of whom 105 (75 per cent) replied. Ninety-five respondents (90 per cent) were immunized against hepatitis B, most (63 per cent) by an occupational health department and the majority within 5 years of this study. Only 80 per cent had had their immunity tested after immunization. Barrier protective techniques were used infrequently, with 30 per cent of respondents wearing impermeable gowns, 14 per cent wearing visors and 9 per cent using double-gloving for all procedures. Department of Health guidelines on protection from hepatitis B were published after this survey and the implementation of these guidelines in an NHS trust hospital is discussed.

Nosocomial infection due to enterococci attributed to a fluidized microsphere bed. The value of pyrolysis mass spectrometry

The potential of fluidised microsphere beds as sources of nosocomial Enterococcal infection was investigated with the help of pyrolysis mass spectrometry. Isolates from clinical specimens collected from two patients who were nursed sequentially on a fluidized microsphere bed were compared with similar isolates cultured from the microspheres before and after decontamination. Pyrolysis mass spectrometry confirmed that nosocomial spread had indeed occurred and that the existing decontamination process was inadequate. Recommendations for improvements to this decontamination process appear to have prevented further cases.

Screening for neuroblastoma: a review of the evidence

Screening infants for the early detection of neuroblastoma is advocated by many paediatric oncologists and is practised in a limited number of places in the developed world, most notably in Japan where a national screening programme has been in operation since 1985. The screening test consists of measurements of the levels of vanillylmandelic acid and homovanillic acid in the urine; these metabolites of catecholamine are excreted in the urine of 92% of patients with clinically presenting neuroblastoma. The prognosis for children with symptomatic neuroblastoma is dependent both on age and stage, with children aged under 1 year and those with tumours of stages I, II, and IVS having a much better prognosis. Screening aims at detecting and treating during the first year those neuroblastomas which would otherwise present at an advanced stage in older children. Evidence from Japan shows that screening achieves the interim outcomes of a shift in the age distribution and stage distribution of neuroblastomas in populations for whom screening has been provided, and that survival of subjects detected by screening is over 90%, compared with around 50% for symptomatic subjects. However, there is not yet any clear evidence that screening results in a reduction in the incidence of advanced neuroblastoma in children over the age of 1, nor a reduction in mortality. Recent cross sectional analyses of age specific incidence and mortality suggest that screening may be having a limited effect, but as yet no analysis of these outcomes in cohorts for whom screening has been provided has been published. Other factors, such as improved chemotherapy, may also be contributing to lower mortality. A number of missed (interval) cancers have been diagnosed in children who screened negative both in the Japanese programme and in Canadian and English studies, indicating that there is a problem with the sensitivity of screening. But the screening test is highly specific with less than 0.1% of infants having false positive results requiring investigation. The natural history of neuroblastoma ranges from highly malignant tumours to biologically benign variants that regress without active treatment, the prevalence of the latter being inversely related to age. Serial measurements of biological markers, including ploidy, chromosome 1p deletion, and N-myc amplification, performed within the same patient at different times indicate that malignant potential does not progress over time. The distribution of these markers in cases detected by screening shows that they are inherently tumours with a good prognosis, whereas the reverse is true of interval cases. Thus screening is differentially picking up the tumours that are least likely to progress and failing to detect at least some tumours of those destined to die from the disease. Comparison of the yield of cancers detected by screening and the expected cumulative incidence of neuroblastoma throughout childhood suggest that screening "overdiagnoses" many non-progressive cases, with consequent physical and psychological morbidity. On balance present evidence suggests that the number of deaths that could be prevented by screening is small and the potential for overdiagnosis is great. Unless further evidence from Japan or the results of a current North American trial conclude otherwise, screening cannot be recommended.

Survival of patients with breast cancer diagnosed in the United Kingdom trial of early detection of breast cancer. United Kingdom Trial of Early Detection of Breast Cancer Group

OBJECTIVE

To examine the survival of patients with breast cancer diagnosed in different centres and by different methods in the United Kingdom trial of early detection of breast cancer, in order to investigate the contribution of different factors to the previously observed reductions in breast cancer mortality.

SETTING

A non-randomised trial of the early detection of breast cancer, in which women aged 45-64 in two districts were offered annual screening for seven years, women in a further two districts were offered education about breast self examination (BSE), and those in four districts formed a comparison group.

METHODS

Patients with breast cancer are classified according to the type of centre, method of detection, and attendance for BSE education. Univariate and multivariate survival analyses are carried out, including tumour size, dissemination status, and use of adjuvant treatment as additional variables.

RESULTS

In the univariate analysis, patients with breast cancer who are non-attenders for screening have a significantly worse prognosis than those in the comparison centres. Patients whose cancer is detected by mammography have the best survival rate. The inclusion of size and dissemination status in the multivariate analysis explains only about one third of the improved prognosis in these cases. There is a significant difference between prognosis in the two BSE centres.

CONCLUSIONS

The use of prognostic factors as recorded in this trial to predict breast cancer mortality may be inadequate.

Serial investigation of balloon angioplasty induced changes in the superficial femoral artery using colour duplex ultrasonography

Percutaneous transluminal balloon angioplasty (PTA) of superficial femoral artery lesions is associated with similar initial success rates in coronary and iliac artery angioplasty but its application is limited by a much higher incidence of restenosis. To improve understanding of the trauma caused to the vessel by balloon angioplasty and the mechanisms contributing to the subsequent processes of healing and restenosis requires serial investigations of the treated arteries in vivo. This paper describes a prospective study using colour duplex ultrasonic imaging to assess arterial changes in 51 patients with atherosclerotic disease undergoing PTA of superficial femoral artery stenoses and occlusions. Each patient was scanned prior to angioplasty and at intervals up to 6 months post-angioplasty. On each scan, measurements were made of the overall vessel and lumen diameters at each site of angioplasty. These measurements indicate that angioplasty improves vessel patency mainly by stretching of the vessel wall, with compression and/or redistribution of the atherosclerotic plaque contributing less than 25% to the improvement of lumen diameter. Serial measurements after angioplasty show complex patterns of change at the angioplasty sites indicating that several mechanisms may be contributing to the processes of vessel healing and subsequent restenosis. Possible mechanisms which could explain the measured changes in overall vessel and lumen diameters are discussed.

Meeting The Health of the Nation target for skin cancer: problems with tackling prevention and monitoring trends

The White Paper The health of the nation challenges us to halt the rising incidence and mortality from skin cancer. Means of achieving this include various approaches to educating the public and modifying sun exposure and promotion of early detection of cancers. Some initiatives can be organized locally but others require national coordination. Evaluation of the impact on health and the cost of preventive programmes is important because the effectiveness of health education packages and campaigns that aim to reduce the incidence or death from skin cancer has yet to be proved. As the majority of skin cancers do not metastasize, it is on melanoma that efforts to improve registration should be focused. Cancer registries have particular difficulty in monitoring the incidence of skin cancer where treatment is simply excision. Improved ascertainment and a shift towards early diagnosis will cause artefactual increases in incidence. Investigation of the trends will therefore require careful interpretation.

Change towards earlier stage at presentation of colorectal cancer

A study was carried out to investigate the change in stage at presentation of patients with colorectal cancer over 10 years. Cases were identified from the control group of subjects enrolled into a randomized controlled study based on Haemoccult screening for colorectal neoplasia. Of 405 subjects in the control group (presenting with symptomatic colorectal cancer, 206 presented before 1989 and 199 since then. The number of patients with Dukes' stage A carcinoma diagnosed since 1989 rose from 21 (10.4 per cent) to 35 (18.1 per cent); this change occurred for rectosigmoid tumours (9.9 per cent before 1989, 28 per cent after 1989) but not for colonic cancer (10.9 per cent before 1989, 11.5 per cent thereafter). An increase in the proportion of patients with symptomatic early-stage rectosigmoid cancer has been observed in the past 10 years. No such change occurred in those with colonic cancer. This may reflect a change in awareness of te disease and its symptoms by patients and general practitioners.