No abstract

No abstract

No abstract

Summary Allelic imbalance or loss of heterozygosity (LOH) has been widely used to assess genetic instability in tumours, and high LOH on chromosome arms 3p, 9p and 17p has been considered to be a common event in non-small-cell lung cancer (NSCLC). We have investigated allelic imbalance in 45 NSCLCs using 92 microsatellite markers on 38 chromosome arms. LOH of 38% was observed on 3p using nine markers, 58% on 9p using 15 markers and 38% on 17p using five markers. Fractional allele loss (FAL) Keywords: non-small-cell lung cancer; loss of heterozygosity; fractional allele loss; distinct genetic population Allelic imbalance or loss of heterozygosity (LOH) has been widely used to assess genetic instability in tumour tissues. The technique has been used primarily to identify regions on specific chromosomes that could contain putative tumoursuppressor genes, but may also be used to produce a measure of accumulated genetic damage within the genome of each tumour. A number of such allelotype analyses have been undertaken in lung and in head and neck cancers (Tsuchiya et al., 1992;Sato et al., 1994;Ah-See et al., 1994;Nawroz et al.,1994; Field et al., 1995), the largest of which has been on squamous cell carcinoma of the head and neck (SCCHN) and involved the use of 145 microsatellite markers (Field et al., 1995). In this study fractional allele loss (FAL) was calculated for all tumours for which data on nine or more chromosomal arms were available, and the median value was found to be 0.22 (FAL was al., 1989). A large allelotype of non-smallcell lung cancers (NSCLCs) using 92 markers has also been undertaken by this group and has found a median FAL value of 0.09 (Neville et al., 1996). Long-term follow-up for this group of NSCLC patients is as yet unavailable, thus no statistical association has been sought between FAL and survival.The presence and role of allelic imbalance on the short arms of chromosomes 3, 9 and 17 in NSCLC has received a Correspondence: JK Field Received 6 March 1996; revised 21 May 1996; accepted 12 July 1996 great deal of attention and it has been argued that these events are associated with the early stages of pathogenesis of these tumours (Sundaresan et al., 1992;Hung et al., 1995;Gazdar et al., 1994; Kishimoto et al., 1995a,b;Thiberville et al., 1995). In these studies, the investigators studied a small number of dysplastic and neoplastic tissues from the same patient in great detail by performing microdissection of the specimens. All of the six paired dysplastic and tumour tissue specimens investigated by Sundaresan et al. (1992) showed allelic imbalance on 3p and, similarly, Hung et al. (1995) found that six of the seven patients examined with paired preneoplastic and neoplastic lesions showed loss on 3p. Kishimoto et al. (1995b) Table I). After resection, the tumours were taken fresh from the theatre, snap frozen in liquid nitrogen and each subjected to frozen section histological examination.

Summary We examined 46 non-small-cell lung carcinomas (NSCLCs) for the presence of p53 mutations in exons 4-9, positive p53 immunostaining and loss of heterozygosity (LOH) in the TP53 locus. p53 mutations were detected in 13 tumour samples (28.3%), whereas overexpression of the p53 protein was found in 30 of 45 (67%) samples. Allelic loss was found in 9 of 38 (23.6%) informative cases. The statistical analysis revealed no significant correlation between p53 mutations and clinicopathological data, although mutations appear to occur more frequently in squamous cell carcinomas (7 of 18) than in adenocarcinomas (2 of 15). All but three individuals in this study group smoked. In contrast to previous reports, we found a higher prevalence of GC-AT transitions than of GC-TA transversions, as expected in a smoking population. A trend was found between p53-positive immunostaining and a history of heavy smoking (76-126 pack-years) and was inversely correlated with allelic deletion (LOH) at the TP53 locus. Eight of the 12 NSCLCs containing p53 mutations also had concomitant p53 overexpression, and it is of specific note that three of the four tumours containing p53 'mutations' with no overexpression of the p53 protein had either insertions or deletions in the p53 gene. No correlation was found between p53 mutations and fractional allele loss or ras mutations. p53 mutations in this Merseyside population in the UK do not appear to be as common as in other reports for NSCLC and exhibit predominance of GC-AT transitions preferentially at non-CpG sites, suggesting that other carcinogens in addition to those in tobacco smoke may be involved in NSCLC in the Merseyside area of the UK.

Summary A series of 12 patients with metastatic squamous cell carcinoma in regional lymph nodes associated with abscess formation is reviewed. The clinical features which may lead the clinician to make a correct diagnosis are emphasized. The management of these lesions is considered.

The effect of an intraluminal tube on the healing of an inadequately constructed colonic anastomosis was evaluated. An anastomosis using a single suture was constructed in 78 rats divided into four experimental groups. In one, a latex tube was sited intraluminally at the level of the anastomosis and removed transanally after six days. In the second, a soft tube consisting of rat duodenum preserved in 5 percent formalin was similarly sited and allowed to pass spontaneously. In the third group, the formalin tube was placed outside the colon surrounding the anastomosis. The fourth group was a control. The mortality of the latex intraluminal tube group was 48 percent, the intraluminal duodenum in formalin group 29 percent (significantly less than the control group, P less than .02), the extraluminal tube around the anastomosis group 100 percent, and the control group 75 percent (P less than .02). There was no significant difference among the experimental groups in the mean breaking strength of the colonic anastomosis in the 28-day survivors.

Summary:A 50 year old man presented with a pyrexial iUlness folowing a holiday abroad. Yersinia pseudotuberculosis was isolated from blood culture. Response to appropriate antibiotic therapy was prompt and complete, but fuUl recovery was complicated by an episode of hyperkalaemia, hyponatraemia and the passing of large volumes ofdilute urine. Three years previously he had developed diabetes meflitus and hypogonadotrophic hypogonadism. Investigation on recovery showed underlying haemochromatosis and aldosterone deficiency.