A variant within the DNA repair gene XRCC3 is associated with the development of melanoma skin cancer.

Exposure to UV radiation is a major risk factor for the development of malignant melanoma. DNA damage caused by UV radiation is thought to play a major role in carcinogenesis induction. Multiprotein pathways involved in repairing UV-DNA damage are the base excision, the nucleotide excision, and the homologous double-stranded DNA repair pathways. This study used a sequence-specific primer PCR (PCR-SSP) genotyping method to investigate the association between polymorphisms in DNA repair genes from these pathways with the development of malignant melanoma. The patient cohort was comprised of 125 individuals with malignant melanoma with lesions or staging suggesting a high risk of relapse or metastatic disease. The control population consisted of 211 individuals. We found the presence of a T allele in exon 7 (position 18067) of the XRCC3 gene was significantly associated with melanoma development (P = 0.004; odds ratio, 2.36; relative risk, 1.74). This gene codes for a protein involved in the homologous pathway of double-stranded DNA repair, thought to repair chromosomal fragmentation, translocations, and deletions. These results may provide further insights into the pathogenesis and the mechanism of UV-radiation induced carcinogenesis as well as having a role in prevention.

Successful treatment of Rhodococcus equi pulmonary infection in a renal transplant recipient.

The rhodococcus is a mycobacterium-like organism which is normally a pathogen in foals. It usually spreads by direct contact or by aerosol from horse faeces and causes pyogranulomatous pulmonary infections. Occasionally, it acts opportunistically to infect immuno-compromised human hosts, most commonly those with the acquired immune deficiency syndrome (AIDS). Here we report a pulmonary infection by Rhodococcus equi in a renal transplant recipient who was successfully treated. The literature on this infection in transplant recipients is also reviewed with respect to manifestations and treatment.

Use of hand-held Doppler to identify 'difficult' forearm veins for cannulation.

Intravenous cannulation is a necessary procedure in many hospital patients. Some patients are regarded as having 'impossible' veins that are invisible and impalpable despite venous tourniquet. We investigated the use of a hand-held Doppler to identify veins suitable for percutaneous cannulation in such patients. A total of 24 arms in 12 patient volunteers with invisible and impalpable forearm veins was studied by squeezing the ipsilateral hand and using a hand-held 8 MHz Doppler probe on the forearm. Each venous signal was noted and the loudest chosen. Classification as 'good' or 'poor' was made on signal strength. The best signal was then mapped and the direction was indicated by a line on the skin. Each forearm was examined using a colour-flow Duplex. All veins were noted and diameters measured with and without tourniquet. These results were compared with the best veins found by hand-held Doppler. In all, 23 (96%) arms had the largest vein correctly identified by the hand-held Doppler. All 19 (100%) described as 'good' on signal had a diameter of 2.0-4.2 mm (mean 3.2 mm). All 4 (100%) described as 'poor' on Doppler signal had diameters of 1.4-1.7 mm (mean 1.6 mm). Hand-held Doppler, used as described, can accurately identify forearm veins larger than 2.0 mm in diameter in patients with invisible and impalpable veins with venous tourinquet. These veins should be amenable to percutaneous cannulation.

Psoas major and its controversial rotational action.

The action of psoas major muscle as a primary flexor of the hip joint is undisputed. However it is also variably reported as being a medial and a lateral rotator of the femur at the hip joint. The psoas and iliacus muscles, along with their common insertion, were isolated by dissection in six adult cadaveric specimens. The action of psoas muscle was assessed by pulling the muscle along its long axis and then observing the effects on rotation of the femur, with a visual estimation of the rotation in degrees. The experiment was repeated with the hip joint capsule removed. In the anatomical position, applied traction along the long axis of the muscle produced hip flexion with no rotational component. With the hip in the abducted position, traction produced flexion, adduction, and lateral rotation of the femur at the hip joint. In adduction of the hip, traction on psoas produced only flexion at the hip joint, with no rotation. In maximal flexion, traction also produced adduction. The results were unaffected by the removal of the joint capsule.

Polymorphisms in tumour necrosis factor (TNF) are associated with risk of bladder cancer and grade of tumour at presentation.

The purpose of this study is to assess the role of tumour necrosis factor (TNF) polymorphisms in the risk of developing bladder cancer and effect on tumour stage, grade and progression. In all, seven single-nucleotide polymorphisms in TNF were studied in 196 bladder cancer patients and 208 controls using a PCR-SSP genotyping technique. It was seen that there was a significant association of two polymorphisms in TNF with bladder cancer: the TNF+488A allele was found in 28.1% of patients compared with 14.9% of controls (P=0.0012). In addition, TNF-859T was found in 26.0% of patients compared with 14.4% of the controls (P=0.0036). The two loci were in tight linkage disequilibrium, that is, almost all the individuals having TNF+488A also had TNF-859T. Patients with the TNF+488A or TNF-859T were more likely to present with a moderately differentiated tumour than those patients without the uncommon allele. In all, 16.7% of patients with TNF+488A and 29.9% of patients without TNF+488A presented with a G1 tumour (P=0.015). A total of 14% of patients with TNF-859T and 30.5% of patients without TNF-859T presented with a G1 tumour (P=0.0043). There was no significant effect on time to first recurrence, stage progression or grade progression. In conclusion, a significant association between TNF polymorphisms TNF+488A and TNF-859T and risk of bladder cancer was detected in this study. Both these polymorphisms were associated with grade of tumour at presentation although there was no significant effect on subsequent tumour behaviour.