Physiological upper limits of ventricular cavity size in highly trained adolescent athletes.

OBJECTIVES: To define physiological upper limits of left ventricular (LV) cavity size in trained adolescent athletes. DESIGN: Cross sectional echocardiographic study. SETTING: British national sports training grounds and Olympic Medical Institute. SUBJECTS: 900 elite adolescent athletes (77% boys) aged 15.7 (1.2) years participating in ball, racket, and endurance sports and 250 healthy controls matched for age, sex, and size. MAIN OUTCOME MEASURES: LV end diastolic cavity size. RESULTS: Compared with controls, athletes had a larger LV cavity (50.8 (3.7) v 47.9 (3.5) mm), a difference of 6%. The LV cavity was > 54 mm in 18% athletes, whereas none of the controls had an LV cavity > 54 mm. The LV cavity exceeded predicted sizes in 117 (13%) athletes. Among the athletes with LV dilatation, 78% were boys, LV size ranged from 52-60 mm, and left atrial diameter and LV wall thickness were enlarged. Systolic and diastolic function were normal. None of the athletes in the study had an LV cavity size > 60 mm. LV cavity size correlated with age, sex, heart rate, and body surface area. CONCLUSION: Highly trained junior athletes usually have only modest increases in LV cavity size. A proportion of trained adolescent athletes have LV cavity size exceeding predicted values but, in absolute terms, LV cavity rarely exceeds 60 mm as in patients with dilated cardiomyopathy. In highly trained adolescent athletes with an LV cavity size > 60 mm and any impairment of systolic or diastolic function, the diagnosis of dilated cardiomyopathy should be considered.

Computer-enhanced laparoscopic training system (CELTS): bridging the gap.

BACKGROUND: There is a large and growing gap between the need for better surgical training methodologies and the systems currently available for such training. In an effort to bridge this gap and overcome the disadvantages of the training simulators now in use, we developed the Computer-Enhanced Laparoscopic Training System (CELTS). METHODS: CELTS is a computer-based system capable of tracking the motion of laparoscopic instruments and providing feedback about performance in real time. CELTS consists of a mechanical interface, a customizable set of tasks, and an Internet-based software interface. The special cognitive and psychomotor skills a laparoscopic surgeon should master were explicitly defined and transformed into quantitative metrics based on kinematics analysis theory. A single global standardized and task-independent scoring system utilizing a z-score statistic was developed. Validation exercises were performed. RESULTS: The scoring system clearly revealed a gap between experts and trainees, irrespective of the task performed; none of the trainees obtained a score above the threshold that distinguishes the two groups. Moreover, CELTS provided educational feedback by identifying the key factors that contributed to the overall score. Among the defined metrics, depth perception, smoothness of motion, instrument orientation, and the outcome of the task are major indicators of performance and key parameters that distinguish experts from trainees. Time and path length alone, which are the most commonly used metrics in currently available systems, are not considered good indicators of performance. CONCLUSION: CELTS is a novel and standardized skills trainer that combines the advantages of computer simulation with the features of the traditional and popular training boxes. CELTS can easily be used with a wide array of tasks and ensures comparability across different training conditions. This report further shows that a set of appropriate and clinically relevant performance metrics can be defined and a standardized scoring system can be designed.

Predictors of outcome in 100 consecutive laparoscopic antireflux procedures.

BACKGROUND: Published success rates for surgical intervention in gastroesophageal reflux disease exceed 90%. The goal of this study was to determine if any preoperative factors could accurately predict postoperative symptom relief. METHODS: One hundred consecutive patients undergoing laparoscopic antireflux surgery completed a detailed preoperative questionnaire, and underwent endoscopy, manometry, and 24-hour esophageal pH monitoring. Two surgeons performed all procedures in a standardized fashion. At least 2 months following operative intervention, a single interviewer, blinded to all preoperative information and procedure performed, recorded Visick and Gastroesophageal Reflux Disease-Health-Related Quality of Life scores for all patients. All follow-up was performed within 3 years of antireflux procedure. RESULTS: The surgical success rate, as defined by Visick scores of 1-2, was 91%. Three variables were predictive of postoperative success: age <50, presence of typical symptoms at presentation, and complete resolution of symptoms with acid suppression therapy. CONCLUSION: The study shows that surgical strategies can reproducibly control gastroesophageal reflux disease symptoms in more than 90% of patients. The optimal surgical candidate is a patient under the age of 50 whose typical symptoms completely resolve with acid suppression therapy.

Intraperitoneal macrophages and tumor immunity: A review.

The macrophage (Mphi) is considered the first line of defense in immune response to foreign invaders. Increasing evidence suggests that Mphi(s) also play an important role against neoplastic cells. Mphi(s) exposed to supraphysiologic concentrations of CO(2) are suppressed. As surgeons apply newer minimally invasive techniques to oncologic therapies, it is important to evaluate the impact of these techniques on host-tumor interactions. We review the current understanding of Mphi biology with specific attention on cytotoxicity in addition to tumor immunity. Although systemic immune function is better preserved after laparoscopy than laparotomy, peritoneal Mphi(s) show reduced function after CO(2) pneumoperitoneum than exposure to air. Mphi(s) have shown cytotoxicity to syngeneic cancer cells and may play an important role in tumor surveillance. The impairment in Mphi function after CO(2) exposure may have an effect on outcome after oncologic surgery. In our understanding, Mphi(s) help destroy neoplastic cells. As CO(2) impairs Mphi activity, laparoscopy may significantly alter the host-tumor interaction.

A stepwise approach to laparoscopic Nissen fundoplication: avoiding technical pitfalls.

Laparoscopic Nissen fundoplication is now widely used in the surgical management of gastroesophageal reflux disease. However, it is a complex operation that requires advanced laparoscopic skills. The learning curve is steep, and complications are directly related to the surgeon's experience level. Both experimental and clinical data demonstrate a decline in complications with increasing experience. We divided this complex procedure into logical and orderly components, to facilitate the learning process. We believe that this approach will not only reduce complications by highlighting potential problems at each stage but also make it easier to teach others.

Microalbuminuria and coronary heart disease in NIDDM: an incidence study.

In most survival studies in NIDDM, microalbuminuria (urinary albumin excretion rate 20-200 microg/min) predicts early mortality; in cross-sectional studies, it is associated with coronary heart disease (CHD) morbidity. It is unclear, however, whether microalbuminuria is a risk factor for the development of CHD or the result of it, and little is known of the factors that predispose to the development of microalbuminuria in NIDDM. We examined these issues in a 7-year prospective study of a hospital-based cohort comprising 146 white NIDDM patients without clinical albuminuria. Microalbuminuria was a significant risk factor for both all-cause mortality (relative risk 3.94, 95% CI 2.04-7.62) and CHD mortality (relative risk 7.40, 95% CI 2.94-18.7) when adjusted for age only. Its independent predictive power did not persist, however, in age-adjusted multivariable survival analysis that allowed for the other significant risk factors: male sex, preexisting CHD, high levels of glycated hemoglobin, and high serum cholesterol. Among men free of CHD at baseline, the independent risk factors for CHD morbidity and mortality were microalbuminuria, current smoking, high diastolic blood pressure, and high serum cholesterol (all P < 0.05). For the 100 NIDDM patients with normoalbuminuria at baseline, the incidence of microalbuminuria was 29% over the 7-year period. In that group, fasting plasma glucose, current smoking, preexisting CHD, and high initial urinary albumin excretion rate were risk factors for the development of microalbuminuria (all P < 0.05). When men and women were analyzed separately, preexisting CHD was a significant risk factor in men only. These results demonstrate that microalbuminuria predicts incident clinical CHD in men with NIDDM. Preexisting CHD is also a risk factor for incident microalbuminuria in men, however, suggesting that microalbuminuria and CHD are not causally related but rather reflect common determinants.

In search of better route guidance instructions.

Safety concerns have prompted designers of in-vehicle route guidance and information systems (IVRGIS) to make more use of an 'audible interface' to convey guidance instructions. Previous research has shown that, contrary to expectations, detailed guidance instructions can have a detrimental effect upon wayfinding performance, particularly for elderly individuals. In response to these findings a second series of experiments was carried out to try to improve the effectiveness of route guidance. Using the same procedure, 40 male and 40 female drivers aged 18-35 years watched video footage of journeys through an unfamiliar area, while hearing guidance that linked direction instructions to landmarks visible at the decision point. Results showed that those who heard these amended instructions performed significantly better than other groups at a wide range of tasks designed to measure the spatial knowledge that they had acquired. This group performed better than groups who heard nothing, and groups who heard full guidance. The results support the view that, whereas full guidance instructions can have a negative impact upon wayfinding performance, less complex instructions that link landmarks to directions have the capacity to enhance wayfinding performance. This is because instructions of this form strengthen the associations made between directions to be taken and the spatial location of these turns, resulting in the formation of a strong representation of the route. The results also showed that those who had been driving for 1 year or less were significantly less accurate at these tasks than those with more driving experience. This result has important implications for the widespread implementation and use of IVRGIS: suggesting that, for newly qualified drivers, who have not yet developed the ability to attend to and process information while controlling the vehicle, attending to route guidance instructions might have a detrimental effect upon driver safety.

Measurement of arterial oxygen-haemoglobin saturation in newborn lambs by pulse oximetry.

Percentage arterial oxygen saturation (SpO2) was measured in 69 neonatal lambs at one, five and 10 minutes after birth using a pulse oximeter applied to the tail. The lambs were given a subjective vitality score from 1 to 4, with 1 being normal and 4 being stillborn. Of the 42 lambs born after a normal parturition, 19 were measured after one minute, 29 after five minutes and 24 after 10 minutes; the mean (sd) SpO2 values of these groups were 67 (15) per cent, 84 (9) per cent and 83 (9) per cent, respectively. Of the 27 lambs born after dystocia, 16 were measured after one minute, 18 after five minutes and 12 after 10 minutes; the mean (sd) SpO2 values of these groups were 61 (15) per cent, 69 (16) per cent and 69 (19) per cent, respectively. The values measured in the lambs born after dystocia were significantly lower than those in the lambs born normally at five and 10 minutes (P < 0.005 and P < 0.05, respectively). Of the lambs born with a vitality score of 1, 24 were measured after one minute, 33 after five minutes and 26 after 10 minutes; they had mean SpO2 values of 72 (11), 82 (10) and 81 (12) per cent, respectively. Of the lambs born with vitality scores of 2 or 3, 11 were measured after one minute, 14 after five minutes and 10 after 10 minutes; they had mean SpO2 values of 48 (6), 68 (17) and 72 (20) per cent, respectively. The SpO2 values of the lambs with vitality scores of 2 or 3 were significantly lower than those of the lambs with a vitality score of 1 at one and five minutes after birth (P < 0.0001 and P < 0.05, respectively).

Oesophageal injury associated with the administration of an anthelmintic bolus to calves.

Six of 18 calves from a suckler herd which were dosed with a sustained-release anthelmintic bolus, using appropriate equipment, developed clinical signs related to oesophageal perforation. Two died as a direct result of the injuries sustained, one required surgical removal of the paraoesophageal bolus and the remaining three were managed medically. The calves were in the approximate weight range advised by the manufacturers as suitable for dosing, but some were younger than the minimum recommended age. These animals were of a fractious nature having been relatively little handed.

A double-blind crossover trial of atenolol, enalapril and the fixed combination of atenolol and nifedipine in mild and moderate hypertension.

Sixty-three patients with mild to moderate hypertension completed a double-blind, randomised crossover trial of atenolol 100 mg daily, enalapril 20 mg daily and the fixed combination atenolol 50 mg and nifedipine retard 20 mg (Tenif) once daily. In the three areas of efficacy that the study compared-24-hour post dose blood pressure, control of blood pressure over the dosing period with particular reference to the waking day and attenuation of systolic blood pressure on exercise-atenolol and the fixed combination demonstrated greater efficacy than enalapril.

A primary demyelinating disorder of young cattle.

The clinical signs and neuropathological changes are described in six Limousin X calves that, at about one month after birth, showed signs of blindness, nystagmus, rotation of the eyes, opisthotonos, hyperprotraction of the forelegs and, in one case, apparent seizures. Pathologically there was necrosis of the optic chiasma and focal areas of myelin sheath vacuolation or demyelination in certain areas of the brain, especially in the cerebellar peduncles. In one animal, kept alive for 7 months, there was remyelination by Schwann cells of some demyelinated axons in the focal cerebellar lesions, while other axons remained demyelinated. There was no evidence of oligodendrocyte remyelination. The cause of the condition was not determined but a genetic association is likely.

Cardiomyopathy in adult Holstein Friesian cattle in Britain.

The clinical signs, pathology and breeding data of two cases of cardiomyopathy of an unusual kind in adult Holstein Friesian cattle in Britain are reported and compared with those in similar entities in Switzerland, Japan and Canada. The principal and primary lesions affect the heart and these produce secondary changes, particularly in the liver, and result in fatal congestive heart failure. The cardiac lesions consist of extensive myocyte vacuolation, endomysial and perimysial fibrosis and focal cardiac myocyte degeneration, atrophy and hypertrophy resulting in an extended range of myocyte size. Lesions affected all four heart chambers but were most severe in the ventricles. Vascular lesions, particularly moderate medial hypertrophy and intimal thickening of arterioles and arteries, occurred in heart, lung, kidney and lymph nodes. The liver showed severe fibrosis, chronic congestion and hepatocyte loss. There was a chronic multifocal nephritis. The cause is unknown, but the affected animals were full brother and sister and have a common ancestor in the male and female line five generations earlier.

Coronary heart disease and urinary albumin excretion rate in type 2 (non-insulin-dependent) diabetic patients.

Associations between overnight urinary albumin excretion rate and prevalent coronary heart disease and its major risk factors were examined in a cross-sectional study of 141 Type 2 (non-insulin-dependent) diabetic patients. Mean albumin excretion rate was higher in men (geometric mean 13.5 micrograms/min; 95% confidence interval 10.3-17.6) than women (7.5 micrograms/min; 5.7-9.8, p less than 0.01). In diabetic men and women mean albumin excretion rate was higher in those with electrocardiographic and/or symptomatic evidence of coronary heart disease than in those without (men, 23.1 micrograms/min; 95% confidence interval 13.7-39.0 versus 10.6 micrograms/min; 7.9-14.2, p less than 0.01, women, 13.7 micrograms/min; 8.0-23.5 versus 5.4 micrograms/min; 4.2-6.8, p less than 0.01). Multiple logistic regression analysis was used to allow for confounding between variables. In the diabetic group as a whole, raised albumin excretion rate (p less than 0.001), gender (p less than 0.05) and systolic blood pressure (p = 0.06) entered the "best" model for coronary heart disease prediction. In women, albumin excretion rate alone (p less than 0.01) and in men albumin excretion rate (p less than 0.01) and age (p = 0.05) entered the "best" models. We conclude that albumin excretion rate is significantly associated with coronary heart disease morbidity after taking into account the confounding effects of raised blood pressure and other cardiovascular risk factors.