Seasonality in communication and collective decision-making in ants

The ability of animals to adjust their behaviour according to seasonal changes in their ecology is crucial for their fitness. Eusocial insects display strong collective behavioural seasonality, yet the mechanisms underlying such changes are poorly understood. We show that nest preference by emigrating Temnothorax albipennis ant colonies is influenced by a season-specific modulatory pheromone that may help tune decision-making according to seasonal constraints. The modulatory pheromone triggers aversion towards low-quality nests and enhances colony cohesion in summer and autumn, but not after overwintering-in agreement with reports that field colonies split in spring and reunite in summer. Interestingly, we show that the pheromone acts by downgrading the perceived value of marked nests by informed and naive individuals. This contrasts with theories of collective intelligence, stating that accurate collective decision-making requires independent evaluation of options by individuals. The violation of independence highlighted here was accordingly shown to increase error rate during emigrations. However, this is counterbalanced by enhanced cohesion and the transmission of valuable information through the colony. Our results support recent claims that optimal decisions are not necessarily those that maximize accuracy. Other criteria-such as cohesion or reward rate-may be more relevant in animal decision-making.

Comparison of treatment and outcome information between a clinical trial and the National Cancer Data Repository

BACKGROUND

Clinical trials are important but many factors limit their success, including the costs of long-term follow-up and participants often not being representative of the general population. The National Cancer Data Repository (NCDR) contains data about patients with cancer in England that may help overcome some of these problems. This study compared treatment and outcome information between the Medical Research Council Conventional versus Laparoscopic-Assisted Surgery in Colorectal Cancer (CLASICC) trial and the NCDR.

METHODS

Participants in the CLASICC trial were identified in the NCDR, and management and outcome data were compared. Data on all surgically treated English patients with colorectal cancer were extracted from the NCDR and compared with those of CLASICC participants.

RESULTS

Survival and treatment data for those in the CLASICC trial were available in the NCDR for 98·9 and 95·8 per cent of patients respectively. There was agreement in operation type for 86·1 per cent of patients but surgical approach coding was poor, with only 58·4 per cent of laparoscopic procedures coded in the NCDR. There was no significant difference in survival calculated from either data set. Surgical information was available in the NCDR for 19 of 20 trial participants with missing data. The trial population was younger (P < 0·001), of better socioeconomic status (P = 0·001) and with earlier disease (P < 0·001) than the general surgically treated colorectal cancer population. Rectal cancer survival was similar, but 5-year survival after treatment of colonic cancer was significantly better in the trial than in the national data: 57·1 (95 per cent confidence interval 51·5 to 62·3) versus 49·8 (49·3 to 50·2) per cent respectively.

CONCLUSION

The National Cancer Data Repository demonstrates potential for informing clinical trials, but limitations prevent full intention-to-treat analyses.

Treatment of massive rotator-cuff tears with a polyester ligament (Dacron) augmentation: clinical outcome

We describe the clinical outcome of a technique of surgical augmentation of chronic massive tears of the rotator cuff using a polyester ligament (Dacron) in 21 symptomatic patients (14 men, seven women) with a mean age of 66.5 years (55.0 to 85.0). All patients had MRI and arthroscopic evidence of chronic massive tears. The clinical outcome was assessed using the Constant and Murley and patient satisfaction scores at a mean follow-up of 36 months (30 to 46). The polyester ligament (500 mm × 10 mm) was passed into the joint via the portal of Neviaser, medial to the tear through healthy cuff. The two ends of the ligament holding the cuff were passed through tunnels made in the proximal humerus at the footprint of the insertion of the cuff. The ligament was tied with a triple knot over the humeral cortex. All the patients remained free from pain (p < 0.001) with improvement in function (p < 0.001) and range of movement (p < 0.001). The mean pre-operative and post-operative Constant scores were 46.7 (39.0 to 61.0) and 85.4 (52.0 to 96.0), respectively (p < 0.001). The mean patient satisfaction score was 90%. There were two failures, one due to a ruptured ligament after one year and the other due to deep-seated infection. The MR scan at the final follow-up confirmed intact and thickened bands in 15 of 17 patients. This technique of augmentation gives consistent relief from pain with improved shoulder movement in patients with symptomatic massive tears of the rotator cuff.

[Transradial peripheral angioplasty]

Radial access for coronary intervention has gained popularity due to a low rate of access site bleeding complications and the possibility for early discharge. The preferential access site for peripheral intervention remains femoral, via antegrade or retrograde puncture. Not all peripheral lesions are suitable for transradial intervention due to the distance between the access site and the lesion location. This technique requires a precise strategy planning and knowledge of the available devices. We describe accessible sites from radial approach and the techniques to be used.

Randomised, placebo-controlled, double-blind study to investigate the efficacy and safety of the acute use of sodium picosulphate in patients with chronic constipation

There are few studies supporting the effective and safe use of laxatives for constipation. This study examined the short-term efficacy and safety of sodium picosulphate in patients with chronic constipation. Patients with a history of chronic constipation for at least 3 months were randomised to receive 7 mg sodium picosulphate or placebo for three consecutive nights. Patients recorded stool frequency and consistency, straining, bloating, and pain at baseline and during treatment. Vital signs, haematocrit, serum creatinine and electrolytes were monitored. Primary end-point for efficacy was the occurrence of a response to treatment, defined as improvement in stool frequency and occurrence of straining. All 57 randomised patients (sodium picosulphate n = 29, placebo n = 28; mean age 54.8 and 54.1 years) completed the study. Sodium picosulphate produced a treatment response (improved stool frequency and straining) in 82.8% compared with 50% in the placebo group (p = 0.010) and reduced bloating more often than placebo. There were no serious adverse events and one patient with diarrhoea and another with abdominal pain in each treatment group. There were no cardiovascular effects, changes in serum haematocrit, creatinine or electrolytes in either group. This study confirmed that sodium picosulphate is an effective, well-tolerated and safe laxative in the acute treatment of constipation.

A Clinical Review of the Investigation and Management of Carcinoma of Unknown Primary in a Single Cancer Network

AIMS

Carcinoma of unknown primary (CUP) is a common encounter in oncological practice and represents 2.0-6.0% of all invasive malignancies. Evidence to support particular therapeutic strategies in this patient population is scarce, and empirical therapies are frequently derived from research on patients where the primary tumour site is known.

MATERIALS AND METHODS

This retrospective study reviewed the management of all patients recorded to have a diagnosis of CUP in a single cancer centre over a period of 12 months. Health records were reviewed documenting the CUP subtype, the investigations carried out both in the referring cancer unit and subsequently at the cancer centre and the recommended treatment (type and regimen), together with survival. The outcomes were examined in respect to a number of prognostic factors. Statistical tests were considered significant at P < 0.05.

RESULTS

One hundred and sixty-six patients were recorded to have a diagnosis of CUP, representing 3.7% of all referrals to the cancer centre. The median age of patients was 68 years (range 32-94 years), and 52.0% were women. The three most common CUP subgroups were CUP-liver/multiple sites (25.0%), CUP-bone (21.0%) and CUP-brain (16.0%). The remaining subgroups occurred at frequencies of less than 10% each. Histological confirmation was only obtained in 55.0% of cases. Even within a single subtype, 41 patients with CUP-liver/multiple sites underwent a total of 19 different investigations before any treatment being given. Forty-seven (28.0%) patients received radiotherapy, 30 (18.0%) received chemotherapy and 58 (35.0%) received supportive care alone. Nine different 5-fluorouracil-containing regimens were used in 11 patients treated with chemotherapy for CUP-liver. The overall median survival for all patients was 4.0 months. Survival was better in patients with a good performance status (0-1) and absent liver metastases (median survival 15.0 months; 95% confidence interval 8.0-22.1) and those who received chemotherapy (median survival 13.0 months; 95% confidence interval 7.4-18.6). Multivariate analysis confirmed female gender (P = 0.006), a good performance status (0/1) (P < 0.0001) and absent liver metastases (P = 0.002) as favourable prognostic indicators.

CONCLUSIONS

The appropriate management of patients with CUP is unclear and this study revealed a high degree of variation in clinical practice. This area is in urgent need of clinical research to ensure that the treatment of CUP is evidence based. Until such time, clinical recommendations are suggested for the investigation and treatment of such patients. Therapeutic progress will be facilitated by designating a clinical lead for CUP in each clinical network.

HapMap-based study of the 17q21 ERBB2 amplicon in susceptibility to breast cancer

ERBB2 is frequently amplified in breast tumours as part of a wide region of amplification on chromosome 17q21. This amplicon contains many candidate genes for breast cancer susceptibility. We used a genetic association study design to determine if common genetic variation (frequency>or=5%) in a 400-kb region surrounding ERBB2 and containing the PPARBP, CRK7, NEUROD2, PPP1R1B, STARD3, TCAP, PNMT, CAB2, ERBB2, C17ORF37, GRB7 and ZNFN1A3 genes, was associated with breast cancer risk. Sixteen tagging single-nucleotide polymorphisms (tSNPs) selected within blocks of linkage disequilibrium from the HapMap database, one HapMap singleton SNP, and six additional SNPs randomly selected from dbSNP were genotyped using Taqman in a large study set of British women (2275 cases, 2280 controls). We observed no association between any of the genotypes or associated haplotypes and disease risk. In order to simulate unidentified SNPs, we performed the leave-one-out cross-validation procedure on the HapMap data; over 90% of the common genetic variation was well represented by tagging polymorphisms. We are therefore likely to have tagged any common variants present in our population. In summary, we found no association between common genetic variation in the 17q21 ERBB2 amplicon and breast cancer risk in British women.