Preoperative Factors Predicting Remission of Type 2 Diabetes Mellitus After Roux-en-Y Gastric Bypass Surgery for Obesity

Background  

Roux-en-Y gastric bypass (RYGB) is an effective treatment for morbid obesity. This bariatric procedure has also been noted to resolve hyperglycaemia in up to 70% of obese diabetics. We evaluated outcomes in diabetic patients undergoing RYGB in our institution, aiming to identify factors predicting diabetes remission.     

Laparoscopic Surgical Skills Assessment: Can Simulators Replace Experts?

Introduction  Global Rating Scales (GRS) quantify and structure subjective expert assessment of skill. Hybrid simulators measure performance during physical laparoscopic tasks through instrument motion analysis. We assessed whether motion analysis metrics were as accurate as structured expert opinion by using GRS. Methods  A random sample of 10 consultant laparoscopic surgeons, 10 senior trainees, and 10 novice students were assessed on a Sharp Dissection task. Coded video footage was reviewed by two blinded assessors and scored using a Likert Scale. Correlation with metrics was tested using Spearman’s rho. Inter-rater reliability was measured using intraclass correlation coefficient (ICC). Results  Strongest GRS–Metric correlations were found for Time/Motion/Progress with Time (Spearman’s rho 0.88; p < 0.05) and Instrument Handling with Path Length (Spearman’s rho 0.8; p < 0.05). Smoothness correlated with Respect for Tissue in Rater 1 (rho 0.68) but not Rater 2 (rho 0.18). Mean GRS showed stronger inter-rater agreement than individual scale components (ICC 0.68). Correlation coefficients with actual experience group were 0.58–0.74 for mean GRS score and 0.67–0.78 for metrics (Spearman’s rho, p < 0.05). Conclusions  Metrics correlate well with GRS assessment, supporting concurrent validity. Metrics predict experience level as accurately as global rating and are construct valid. Hybrid simulators could provide resource-efficient feedback, freeing trainers to concentrate on teaching.     

Fine-scale human genetic structure in Western France

The difficulties arising from association analysis with rare variants underline the importance of suitable reference population cohorts, which integrate detailed spatial information. We analyzed a sample of 1684 individuals from Western France, who were genotyped at genome-wide level, from two cohorts D.E.S.I.R and CavsGen. We found that fine-scale population structure occurs at the scale of Western France, with distinct admixture proportions for individuals originating from the Brittany Region and the Vendée Department. Genetic differentiation increases with distance at a high rate in these two parts of Northwestern France and linkage disequilibrium is higher in Brittany suggesting a lower effective population size. When looking for genomic regions informative about Breton origin, we found two prominent associated regions that include the lactase region and the HLA complex. For both the lactase and the HLA regions, there is a low differentiation between Bretons and Irish, and this is also found at the genome-wide level. At a more refined scale, and within the Pays de la Loire Region, we also found evidence of fine-scale population structure, although principal component analysis showed that individuals from different departments cannot be confidently discriminated. Because of the evidence for fine-scale genetic structure in Western France, we anticipate that rare and geographically localized variants will be identified in future full-sequence analyses.     

A monoclonal antibody (3A33) that reacts with a mouse-specific epitope of Mac-1 antigen

The 3A33 monoclonal antibody, obtained by fusing rat immune lymphocytes with mouse plasmacytoma cells, was directed against mouse macrophages. Antibody 3A33, a rat IgG2a, reacted with macrophages from all the mouse strains tested, with mouse blood monocytes and with 56% of bone marrow cells, but not with T lymphocytes. It immunoprecipitated an antigen with alpha and beta subunits, found to be identical to Mac-1 antigen after cross-absorption experiments with M1/70 monoclonal antibody. The two antigenic determinants of the Mac-1 molecule identified by the 3A33 and M1/70 antibodies both displayed reduced expression on inflammatory macrophages and comparable resistance to trypsin digestion. The sites of the determinants on this molecule seemed close together judging from the ability of both the 3A33 and M1/70 antibodies to block C3bi receptor sites and compete for cell binding. However, unlike antibody M1/70, 3A33 never reacted with human cells bearing Mac-1 antigen. Therefore, two closely related epitopes of the Mac-1 molecule - one specific for mouse and one common to mouse and man, were recognized by these monoclonal antibodies.     

Proton NMR relaxation times of experimental Lewis lung carcinoma after irradiation

NMR proton spin-lattice (T1) and spin-spin (T2) relaxation times were measured ex vivo on Lewis lung carcinoma after in vivo single irradiation with an absorbed dose of 4 Gy. The results were compared to tumoural volume evolution, pathological examinations, and cell kinetic measurements. Tumour growth decreased between the third and the sixth day after irradiation while relaxation times, especially T1, is increased 2 days before the clinical recurrence of the tumour is observed. Pathological morphometric measurements tempted to show that necrosis is less extended after irradiation. Cell cycle analysis demonstrated the G2/M phase blockade by radiation after one day, and its release 4 days later. These phenomena could be important for in vivo radiotherapy follow-up using determination of relaxation times by magnetic resonance imaging (MRI).     

Dentinal tubule penetration of AH Plus,BC Sealer and a novel tricalcium silicate sealer: a confocal laser scanning microscopy study

Objectives

The aim of this in vitro study was to assess the dentinal tubule penetration of three different sealers, AH Plus, BC Sealer and a novel tricalcium silicate sealer (NTS).

Materials and methods

Ninety-six human maxillary central incisors were divided into three experimental groups (n = 32) and were filled with gutta-percha using a single-cone technique in conjunction with one of the three sealers: AH Plus, BC Sealer or NTS. The roots in each group were cross-sectioned at 1 and 5 mm from the root apex, and the surfaces were examined under confocal laser scanning microscopy (CLSM). The sealer penetration depths were measured at their maximum depths and at four circumferential depths (12, 3, 6 and 9 o’clock) and were evaluated using ImageJ software (ImageJ, NIH).

Results

The maximum and mean penetration depths were significantly higher at 5 mm compared to 1 mm from the apex in the AH Plus (p < 0.001), BC Sealer (p < 0.001) and NTS groups (p < 0.001). No significant difference was observed between the groups at 1 mm for both parameters. The maximum and mean penetration depths were significantly lower at 5 mm for AH Plus compared with the other two groups (p = 0.012).

Conclusions

Within the study limitations, the BC Sealer and NTS demonstrated better tubule penetration results than the AH Plus sealer.

Clinical relevance

Although no study has confirmed a relationship between the penetration depth of root canal sealers and the prevention of apical periodontitis, dentinal tubule sealer penetration may improve obturation quality.

     

Safety and efficacy of self‐expanding removable metal esophageal stents during neoadjuvant chemotherapy for resectable esophageal cancer

Patients with esophageal cancer may present with dysphagia and weight loss. Resectable lesions require consideration of neoadjuvant chemotherapy, which improves survival but have side effects, which compound already poor intake. Prevention of malnutrition has historically required interventions such as surgical jejunostomy or percutaneous endoscopic gastrostomy, which carry associated morbidity. With established roles in palliation, self‐expanding removable metal stents (SERMS) may provide an alternative intervention in resectable disease. We sought to evaluate outcomes from our unit's introduction of SERMS in dysphagic patients prior to esophagectomy. All dysphagic patients presenting with esophageal cancer and considered for curative surgery between April 2006 and November 2008 were offered preoperative treatment of dysphagia with SERMS during neoadjuvant chemotherapy. Baseline and preoperative outcomes assessed included dysphagia score and nutritional markers. Sixteen patients underwent esophageal stenting during neoadjuvant therapy of whom 7/16 (44%) were female with mean age 63 (53–76). In 12/16 (75%), tumors were located in the lower one third of the esophagus. There was a significant fall in mean dysphagia score from 2.5 (range 1–4) to 1.1 (range 0–3) immediately preoperatively. There was no significant change in serum albumin, weight, or body mass index. Stent‐related morbidity occurred in 4/16 (25%) patients and stomach migration occurred in 7/16 (43.8%). All were resolved endoscopically and there was no stent‐related mortality. Of 10/16 (62.5%) patients ultimately progressing to esophagectomy, 30‐day mortality was 6.3%. Anastomotic leak occurred in one patient (10%) and R1 resection rate was 20%. SERMS are a safe and effective intervention in dysphagic patients undergoing neoadjuvant chemotherapy for esophageal cancer. Complications are minor and readily treatable with endoscopy. Objective parameters suggest nutritional status is maintained and symptoms are improved. SERMS do not appear to compromise resection.