The role of endoscopic endonasal surgery in the management of prolactinomas based on their invasiveness into the cavernous sinus

Pituitary - To review our institutional experience with the surgical management of prolactinomas through the endoscopic endonasal approach with specific focus on cavernous sinus invasion....     

A new site-specific integration system for mycobacteria

Site-specific integration into the mycobacterial chromosome can produce stable transformants useful for understanding pathogenesis. However, gene expression can be problematic at certain sites of integration. We have used the Streptomyces phiC31 integration system to integrate vector DNA into Mycobacterium smegmatis, M. bovis BCG, and M. tuberculosis through site-specific recombination. A single dominant insertion site was found in M. smegmatis, as previously reported. Three different insertion sites were found in M. bovis BCG. In M. smegmatis, integrated vectors appear to be far more stable than episomal plasmids during unselected passage in vitro, although excision products are detectable. Plasmids based on the phiC31 integration system could make useful tools for the study of mycobacterial genetics.     

Canadian pediatric gastroenterology workforce: current status, concerns and future projections.

BACKGROUND: There is concern that the Canadian pediatric gastroenterology workforce is inadequate to meet health care demands of the pediatric population. The Canadian Association of Gastroenterology Pediatric Committee performed a survey to determine characteristics and future plans of the Canadian pediatric gastroenterology workforce and trainees. METHODS: Estimates of total and pediatric populations were obtained from the 2001 Census of Population, Statistics Canada (with estimates to July 1, 2005). Data on Canadian pediatric gastroenterologists, including clinical full-time equivalents, sex, work interests, opinions on workforce adequacy, retirement plans, fellowship training programs and future employment plans of fellows, were gathered through e-mail surveys and telephone correspondence in 2005 and 2006. RESULTS: Canada had an estimated population of 32,270,507 in 2005 (6,967,853 people aged zero to 17 years). The pediatric gastroenterology workforce was estimated at 9.2 specialists per million children. Women accounted for 50% of the workforce. Physician to pediatric population ratios varied, with Alberta demonstrating the highest and Saskatchewan the lowest ratios (1:69,404 versus 1:240,950, respectively). Between 1998 and 2005, Canadian pediatric gastroenterology fellowship programs trained 65 fellows (65% international trainees). Twenty-two fellows (34%) entered the Canadian workforce. CONCLUSIONS: The survey highlights the variable and overall low numbers of pediatric gastroenterologists across Canada, an increasingly female workforce, a greater percentage of part-time physicians and a small cohort of Canadian trainees. In conjunction with high projected retirement rates, greater demands on the workforce and desires to partake in nonclinical activities, there is concern for an increasing shortage of pediatric gastroenterologists in Canada in future years.     

Aspirin and clopidogrel resistance: an emerging clinical entity.

Antiplatelet therapy is a cornerstone of cardiovascular medicine. Aspirin and clopidogrel have emerged as critical therapies in the treatment of cardiovascular disease. Despite their efficacy, patients on these medications continue to suffer complications. Millions of patients are currently on low-dose antiplatelet therapy but it is unknown how many of these patients are under-treated or on the wrong medication. Aspirin and clopidogrel resistance are emerging clinical entities with potentially severe consequences such as recurrent myocardial infarction, stroke, or death. The mechanism of resistance remains incompletely defined, but there are specific clinical, cellular, and genetic factors that influence therapeutic failure. These factors range from physicians who fail to prescribe these medications despite appropriate indications to polymorphisms of platelet membrane glycoproteins. Rapid and accurate diagnosis of antiplatelet resistance also remains an issue as new bedside tests are developed. By understanding the mechanism of therapeutic failure and by improving the diagnosis of this clinical entity, a new era of individualized antiplatelet therapy may arise with routine measurements of platelet activity in the same way that cholesterol, blood pressure, and blood sugar are followed, thus improving the care for millions of people.     

Gastric lesions secondary to long-distance running

Gastrointestinal disorders have been reported during long- distance running. The purpose of this study was to evaluate the effects of prolonged exercise on the upper digestive tract. Seven subjects were submitted to a standard endoscopic examination of the upper digestive tract before and after long- distance running (range 18– 50 km). Mucosal biopsy specimens were taken during all endoscopies. After running, all runners had histologically pathological features in the stomach. Vascular lesions were present in the chorion in six subjects after running, with the intensity of the lesions ranging from congestion to hemorrhage. Postexercise histological examination also showed a decrease in mucosal secretion. These lesions secondary to prolonged exercise indicate the presence of hemodynamic perturbations in the upper digestive tract.     

Common chronic diseases and general impairments as determinants of walking disability in the oldest-old population

OBJECTIVES: Walking disability affects older people's autonomy and well-being. We investigated the relative effect of common chronic diseases and general impairments on walking disability in the general oldest-old population. DESIGN: Population-based cohort study. SETTING: Leiden 85-plus Study, the Netherlands. PARTICIPANTS: Five hundred ninety-nine persons aged 85, response rate 87%. MEASUREMENTS: Walking disability was assessed using a 6-meter walking test. Persons with a walking time below the 25th percentile and those who were physically unable to perform the walking test were categorized as having a walking disability. Information on common chronic diseases was obtained from records of subjects' general practitioners and pharmacies. General impairments were assessed with functional tests and standardized questions during face-to-face interviews. We expressed the effect of common chronic diseases and general impairments as the population attributable risk (PAR), indicating how much disability can be prevented when the identified risk factor is eliminated from the population. RESULTS: One hundred ninety-two persons (33%) had a walking disability. This disability was highly associated with poor mobility in daily life, recurrent falls, and poor well-being (all P <.001). Of the common chronic diseases, stroke, angina pectoris, diabetes mellitus, and hip fracture but not arthritis contributed most (PARs from 6% to 15%) to walking disability in the population at large. General impairments had higher prevalence rates and higher PARs than common chronic diseases. Cognitive impairment, depressive symptoms, and dizziness upon rising contributed most (PARs between 22 to 27%) to walking disability. In multivariate regression analyses of all common chronic diseases and general impairments, associations remained significant. CONCLUSION: Within the general oldest-old population, general impairments contribute more substantially to walking disability than do common chronic diseases. The diagnosed diseases did not explain the impairments that led to walking disability. Especially in the oldest old, clinicians should focus not merely on common chronic diseases but particularly on general impairments as targets for diagnostic analysis and treatment to decrease walking disability.     

Practical recommendations for the use of ACE inhibitors, beta-blockers, aldosterone antagonists and angiotensin receptor blockers in heart failure: putting guidelines into practice

Surveys of prescribing patterns in both hospitals and primary care have usually shown delays in translating the evidence from clinical trials of pharmacological agents into clinical practice, thereby denying patients with heart failure (HF) the benefits of drug treatments proven to improve well-being and prolong life. This may be due to unfamiliarity with the evidence-base for these therapies, the clinical guidelines recommending the use of these treatments or both, as well as concerns regarding adverse events. ACE inhibitors have long been the cornerstone of therapy for systolic HF irrespective of aetiology. Recent trials have now shown that treatment with beta-blockers, aldosterone antagonists and angiotensin receptor blockers also leads to substantial improvements in outcome. In order to accelerate the safe uptake of these treatments and to ensure that all eligible patients receive the most appropriate medications, a clear and concise set of clinical recommendations has been prepared by a group of clinicians with practical expertise in the management of HF. The objective of these recommendations is to provide practical guidance for non-specialists, in order to increase the use of evidenced based therapy for HF. These practical recommendations are meant to serve as a supplement to, rather than replacement of, existing HF guidelines.     

Computed Tomography Angiography with Three‐dimensional Reconstruction for Pulmony Venous Definition in High‐risk Infants with Congenital Heart Disease

Background. Pulmonary venous anomalies may be difficult to define in small, critically ill infants using standard echocardiography. In many centers, invasive cardiac catheterization is used if the diagnosis remains inconclusive. We evaluated computed tomography angiography (CTA) as a low‐risk alternative to cardiac catheterization in these infants. Methods. All infants <7 kg with congenital heart disease who had undergone CTA in a tertiary care pediatric institution during a 30‐month period were included. All had undergone preceding echocardiography, with pulmonary veins defined as normal (group A, n = 40), or abnormal (group B, n = 16). In 6 group B patients, a conclusive diagnosis could not be made by echocardiogram alone. CTAs were analyzed only if contrast density in the left atrium exceeded 200 Houndsfield units. CTA diagnoses (using axial and reformatted 3‐dimensional still frame images, and audio video interleaved loops) were compared with preceding echocardiograms (group A), or echocardiography, catheterization angiography, or surgical findings (group B). Results. Fifty‐six patients (mean age 12.4 weeks; range 0–64; mean weight 4.19 kg; range 1.4–7) were included. There were no scan complications. Mean scan duration was 4.6 seconds (range 1.84–11). Scan indications in group A were related mainly to arch (57.5%) and airway issues (17.5%). In group B, most patients had variations of anomalous pulmonary venous return (43.75%), with postsurgical stenosis the second largest group (31.25%). CTA diagnoses were confirmed in all patients. Additional diagnostic confirmation in group B was made at catheterization (1/16) or during surgical intervention (15/16). Conclusion. Normal and abnormal pulmonary veins could be defined accurately, safely, and rapidly by CTA in all cases. Three‐dimensional reformatting provided additional assistance with surgical planning. Echocardiography remains the first‐line choice for diagnostic imaging in all patients with pulmonary venous anomalies. However, when echo diagnosis is inconclusive, CTA and not catheterization should be considered the next imaging modality of choice.     

Risk of Second Cancers in Patients with Colorectal Carcinoids

INTRODUCTION: It is often stated that patients with colorectal carcinoid tumors have an increased risk of developing other malignancies. However, this risk has not been conclusively documented. A comprehensive evaluation is needed to more thoroughly assess the risk of second cancers in patients with colorectal carcinoids. METHODS: A search of the National Cancer Institute Surveillance, Epidemiology, and End Result database from 1973 to 1996 revealed 2,086 patients with colorectal carcinoids. This subset of patients was examined for occurrence of second cancers. The observed incidence of cancer for each site was compared with the expected incidence based on the gender-adjusted and age-adjusted cancer rates in the remaining Surveillance, Epidemiology, and End Result file. A Poisson distribution probability was used to determine the significance of these comparisons. RESULTS: Patients with colorectal carcinoids had an increased rate of cancer in the colon and rectum (P < 0.001), small bowel (P < 0.001), esophagus/stomach (P = 0.02), lung/bronchus (P < 0.001), urinary tract (P = 0.005), and prostate (P < 0.001), when compared with a control population. Most of the gastrointestinal tract cancers were synchronous cancers, whereas lesions outside the gastrointestinal tract were most commonly metachronous tumors. CONCLUSIONS: A significantly increased risk of synchronous colorectal, small-bowel, gastric, and esophageal cancers and metachronous lung, prostate, and urinary tract neoplasms is clearly demonstrated. After the diagnosis of colorectal carcinoid tumors, patients should undergo appropriate screening and surveillance for cancer at these sites.