An efficient record linkage scheme using graphical analysis for identifier error detection

Background  

Integration of information on individuals (record linkage) is a key problem in healthcare delivery, epidemiology, and "business intelligence" applications. It is now common to be required to link very large numbers of records, often containing various combinations of theoretically unique identifiers, such as NHS numbers, which are both incomplete and error-prone.     

Operative time is a poor surrogate for the learning curve in laparoscopic colorectal surgery

Background Previous studies have relied on conversion rate and operative time for construction of learning curves in laparoscopic colorectal surgery. The authors hypothesized that conversion rate and operative time were less important than complication and readmission rates in defining good outcomes and hence the learning curve. Methods A database of 287 consecutive laparoscopic colorectal resections from a single tertiary referral center was analyzed. Outcome measures included operative time, conversion rate, major and minor complications, length of hospital stay, and the 15- and 30-day hospital readmission rate. Data were analyzed both by surgeons and by quartile case numbers. Results A total of 151 right colectomies and 136 left colectomies were performed between 1995 and 2005. For both right and left colectomies, the conversion rate decreased in each of the first three quartiles, reaching a nadir of 0% for right colectomies and 3% for left colectomies in the third quartile. The conversion rates increased slightly in the fourth quartile. The operative time remained stable for three quartiles, then increased slightly in the fourth quartile. Two surgeons managed 199 of the 287 cases. Analysis of the two high-volume surgeons demonstrated that for left-sided resections, the surgeon with the shorter operative times had the higher major complication rate (13% vs 2%), overall complication rate (22% vs 2%), 30-day readmission rate (13% vs 0%), and length of stay (3.8 vs 3.1 days) (p < 0.05 for all comparisons). Conclusions In this series, operative time failed to decrease with experience, and shorter operative times did not correlate with better clinical outcomes. The failure of operative time to decline with experience often reflects surgeons’ willingness to attempt more difficult cases rather than an accurate representation of a “learning curve.” Therefore, complication and readmission rates are more important than operative time and conversion rates for evaluating the learning curve and quality of laparoscopic colorectal surgery.     

Profound hypothermic cardiopulmonary bypass facilitates survival without a high complication rate in a swine model of complex vascular, splenic, and colon injuries

BACKGROUND: Induction of a profound hypothermia for emergency preservation and resuscitation in severe hemorrhagic shock can improve survival from lethal injuries, but the impact of hypothermia on bleeding and infectious complications has not been completely determined. STUDY DESIGN: Uncontrolled hemorrhage was induced in 26 swine (95 to 135 lbs) by creating an iliac artery and vein injury, and 30 minutes later, by lacerating the descending thoracic aorta. Through a left thoracotomy approach, profound total body hypothermia (10 degrees C) was induced (2 degrees C/min) by infusing cold organ preservation solution into the aorta. The experimental groups were: vascular injuries alone (group 1, n=10), vascular and colon injuries (group 2, n=8), and vascular, colon, and splenic injuries (group 3, n=8). All injuries were repaired during 60 minutes of low-flow cardiopulmonary bypass (CPB) with hemodilution and profound hypothermia; then the animals were slowly rewarmed (0.5 degrees C/min) back to normothermia. Survivors were monitored for 6 weeks for postoperative bleeding, neurologic deficits, cognitive function (learning new skills), organ dysfunction, and septic complications. RESULTS: Six-week survival rates were 90% in group 1, 87.5% in group 2, and 75% in group 3 (p > 0.05). One animal in each group died from acute cardiac failure during the early postoperative phase. Splenic salvage was possible in all animals, and none required complete splenectomy for hemorrhage control. All surviving animals were neurologically intact, displayed normal learning capacity, and had no longterm organ dysfunction. None of the animals had postoperative hemorrhage or experienced septic complications. One animal in group 3 died on the ninth postoperative day because of bowel obstruction (volvulus). CONCLUSIONS: Induction of profound hypothermia can preserve the viability of key organs during repair of lethal injuries. This strategy can be used even in the presence of solid organ and bowel injuries to improve survival, without any considerable increase in postoperative complication rates.     

Early diagnosis of nonviable pregnancy with endovaginal US

The mean diameter of the gestation sac and the presence or absence of a yolk sac or embryo and/or cardiac pulsations on endovaginal ultrasound (US) images were correlated with normal and abnormal outcomes of pregnancy. Sixty-two patients who were less than 10 weeks pregnant (menstrual age) underwent endovaginal US. In 59 patients with gestation sacs greater than or equal to 8 mm, the absence of a yolk sac predicted a nonviable pregnancy with a sensitivity of 67% and a specificity of 100%. In 35 patients with gestation sacs greater than or equal to 16 mm, the absence of an embryo predicted a nonviable pregnancy with a sensitivity of 50% and a specificity of 100%. When the absence of cardiac pulsations was added to the latter group of patients, the sensitivity was 100% and the specificity was 100%. The combination of these criteria (gestation sac size; demonstration of yolk sac, embryo and/or cardiac pulsations) enabled the early (less than 10 weeks menstrual age) diagnosis of a nonviable pregnancy with endovaginal US.     

Stimulation of proliferation of human myeloid leukemia cells in culture: applications for cytogenetic analysis

The use of chromosome banding techniques has provided a valuable diagnostic tool in various malignancies. The application of these methods, however, is often restricted by a low yield of mitotic cells and the patient's unwillingness to comply with repeated bone marrow aspiration. In an attempt to promote mitotic activity of leukemic cells from the bone marrow and peripheral blood, we employed a new method based on culturing the cells in the presence of a conditioned medium derived from a human bladder carcinoma cell line (5637). In addition to colony stimulating factor, this conditioned medium contains a factor that is capable of stimulating leukemic myeloblast proliferation. Bone marrow and peripheral blood mononuclear cells from 58 patients with a variety of myeloid leukemias were cultured for 24 to 120 hours in the presence or absence of conditioned medium. These bone marrow cells showed a pronounced increase in the mitotic index (5- to 50-fold) as compared to unstimulated cultures, and a greater than 100-fold increase as compared to fresh, uncultured bone marrow cells. Analyzable metaphases could be obtained even in marrow samples in which direct or 24-hour G-banding techniques had failed to reveal metaphases. The effect observed on peripheral blood cells was even more dramatic because prior to culture no mitotic cells were detected, whereas up to 2% mitotic cells were found in conditioned medium-stimulated peripheral leukemic cells. Karyotype analysis of 36 out of the 58 leukemic patients has shown that the chromosome changes discovered in conditioned medium stimulated cells were identical to those found in unstimulated cells. New chromosome aberrations, attributable to the stimulation of growth by conditioned medium, were not found. The quality of the metaphases analyzed following conditioned medium stimulation was considerably better than that of unstimulated samples. Frozen cells, when cultured with conditioned medium, were also suitable for cytogenetic analysis. Thus, the use of this conditioned medium permits adequate cytogenetic analysis even in cases where such analysis was previously impossible.     

Conquering the complex world of human septins: implications for health and disease

Peterson EA and Petty EM. Conquering the complex world of human septins: implications for health and disease. Septins are highly conserved filamentous proteins first characterized in budding yeast and subsequently identified in must eukaryotes. Septins can bind and hydrolyze GTP, which is intrinsically related to their formation of septin hexamers and functional protein interactions. The human septin family is composed of 14 loci, SEPT1‐SEPT14, which encode dozens of different septin proteins. Their central GTPase and polybasic domain regions are highly conserved but they diverge in their N‐terminus and/or C‐terminus. The mechanism by which the different isoforms are generated is not yet well understood, but one can hypothesize that the use of different promoters and/or alternative splicing could give rise to these variants. Septins perform diverse cellular functions according to tissue expression and their interacting partners. Functions identified to date include cell division, chromosome segregation, protein scaffolding, cellular polarity, motility, membrane dynamics, vesicle trafficking, exocytosis, apoptosis, and DNA damage response. Their expression is tightly regulated to maintain proper filament assembly and normal cellular functions. Alterations of these proteins, by mutation or expression changes, have been associated with a variety of cancers and neurological diseases. The association of septins with cancer results from alterations of expression in solid tumors or translocations in leukemias [mixed lineage leukemia (MLL)]. Expression changes in septins have also been associated with neurological conditions such as Alzheimer's and Parkinson's disease, as well as retinopathies, hepatitis C, spermatogenesis and Listeria infection. Pathogenic mutations of SEPT9 were identified in the autosomal dominant neurological disorder hereditary neuralgic amyotrophy (HNA). Human septin research over the past decade has established their importance in cell biology and human disease. Further functional characterization of septins is crucial to our understanding of their possible diagnostic, prognostic, and therapeutic applications.     

The spectrum of paediatric dermatoses in a university hospital in Cairo,Egypt

Background Epidemiological data on paediatric dermatoses in Egypt are scanty. Objective To study the spectrum of paediatric dermatoses in Cairo. Methods The medical records of children attending the dermatology outpatient clinics of Ain Shams University hospital for the year 2001 were retrieved. Data of 3049 patients were included. Demographic data (age and gender) and diagnoses were extracted, coded and analysed. Results Patients’ attendance peaked in summer (42.57%) and revealed female predominance (1.3 : 1). Infections constituted most of dermatoses (52.87%) and impetigo was most common (12.04%). Hypersensitivity came after (18.6%), and contact dermatitis prevailed (6.03%). Females predominated in most dermatoses. Bacterial infections were the most common in both genders. Age distribution revealed prevalence of bacterial infections in infants and preschool children, parasitic infections in school children and sebaceous gland disorders in adolescents. Parasitic infections prevailed in winter and spring, whereas bacterial infections prevailed in summer and autumn. Most dermatoses peaked in summer except urticaria and chicken pox that peaked in spring. Conclusion Infections outnumbered other paediatric dermatoses parallel to the situation in developing communities. Such diseases are potentially controllable and therefore strategies that target infections may represent a key to an efficient child health care programme.