Vigorous physical activity and longitudinal associations with cardiometabolic risk factors in youth.

OBJECTIVE: To examine the longitudinal associations between different physical activity (PA) intensities and cardiometabolic risk factors among a sample of Canadian youth. METHODS: The findings are based on a 2-year prospective cohort study in a convenience sample of 315 youth aged 9-15 years at baseline from rural and urban schools in Alberta, Canada. Different intensities (light, moderate and vigorous) of PA were objectively assessed with Actical accelerometers. The main outcome measures were body mass index (BMI) z-score, waist circumference, cardiorespiratory fitness and systolic blood pressure at 2-year-follow-up and conditional BMI z-score velocity. A series of linear regression models were conducted to investigate the associations after adjusting for potential confounders. RESULTS: At follow-up, cardiorespiratory fitness increased (quartile 1 vs quartile 4=43.3 vs 50.2; P(trend)<0.01) and waist circumference decreased (quartile 1 vs quartile 4=79.0 vs 72.6; P(trend)=0.04; boys only) in a dose-response manner across quartiles of baseline vigorous-intensity PA. A similar trend was observed for systolic blood pressure (quartile 1 vs quartile 4=121.8 vs 115.3; P(trend)=0.07; boys only). Compared with quartile 1 of vigorous-intensity PA, BMI z-score at follow-up and conditional BMI z-score velocity were significantly lower in the quartile 2 and 3 (P<0.05). Waist circumference at follow-up also decreased (quartile 1 vs quartile 4=75.3 vs 73.8; P(trend)=0.04) across quartiles of baseline moderate-intensity PA. CONCLUSIONS: Time spent in vigorous-intensity PA was associated with several positive health outcomes 2 years later. These findings suggest that high-intensity activities in youth help to reduce the risk for several chronic diseases.

Single cycle to failure in bending of three standard and five locking plates and plate constructs.

OBJECTIVE: To evaluate the biomechanical properties of standard and locking plates in bending. We hypothesised that titanium (Ti) constructs would have the greatest deformation and that String of Pearl (SOP) constructs would have the greatest strength and stiffness, and would behave differently compared to plates alone. METHODS: Dynamic compression plates (DCP), stainless steel (SS) limited contact (LC)-DCP®, Ti LC-DCP, locking compression plates (LCP), 10 mm and 11 mm advanced locking plate system (ALPS 10 / 11), SOP and Fixin plates were evaluated individually and as constructs applied to a validated bone model simulating a bridging osteosynthesis. Bending stiffness and strength were compared using one-way ANOVA with post hoc Tukey, and unpaired t-test (p <0.05). RESULTS: The SOP plates had significantly greater stiffness than all other plates; Ti LC-DCP, ALPS 10 and Fixin plates had significantly lower stiffness than all other plates. The SOP constructs had the highest mean bending stiffness, and strength that was significantly different from only the Ti LC-DCP, ALPS 10 and Fixin constructs. The ALPS 10 constructs had the lowest mean bending stiffness, and strength that was significantly different from only ALPS 11 and SOP constructs. Comparison of bending structural stiffness of plates versus constructs showed a significant difference in all plate pairs except for the DCP and ALPS 10. CLINICAL RELEVANCE: Due to differing plate construct properties inherent to these diverse implant systems, identical approaches to fracture management and plate application cannot be applied.

Operative cholangiography: is there a statistical alternative?

Data from 424 patients who underwent cholecystectomy were analysed on a computer by both univariate and multivariate methods to determine the factors that identify patients with stones in the common bile duct. The presence of common bile duct stones was associated with increased age (p = 0.003), increased numbers of gallbladder stones (p less than 0.0001), a diagnosis of acute cholecystitis (p = 0.06), and a history of jaundice (chi-square = 22.2; p less than 0.001). A dilated common bile duct was the most significant indicator of the presence of stones (chi-square = 155.5; p less than 0.0001), and a dilated cystic duct was second (chi-square = 47; p less than 0.001). Using multivariate analysis, 89.5 percent of patients were correctly classified as having bile duct stones without the use of cholangiographic data (chi-square = 246.5; p less than 0.0001). Common bile duct diameter and the number of gallbladder stones emerged as the most important variables; additional historical factors, including the presence of jaundice and pancreatitis did not add to their predictive value. If multivariate analysis was used without cholangiographic data, bile duct stones would be missed in 3 percent of patients and unnecessary explorations would be carried out in 7.5 percent.

Ultrasonic diagnosis of choledochal cyst in pregnancy.

Two patients are reported with obstructive jaundice in pregnancy. In one of these ultrasonic scanning confirmed a diagnosis of choledochal cyst, and in the other made this diagnosis. Ultrasonic scanning is suggested as the preliminary radiological examination for obstructive jaundice in pregnancy. Any patient with a clinical diagnosis of choledochal cysts should have an ultrasonic scan.

HIDA scanning in gall-bladder disease.

HIDA labelled with 99Tcm is a new hepatobiliary imaging radiopharmaceutical which is selectively taken up by the liver and excreted into the biliary tree; it has been shown to demonstrate the gall bladder in normal subjects. Using a gamma-camera computer system, dynamic liver scans were performed during the first hour on 97 patients who, on the basis of standard investigations and on the findings at surgery, were divided into six groups as follows. 1. Normal. 2. Hepatocellular disease. 3. Biliary obstruction. 4. Chronic gall-bladder disease. 5. Acute gall-bladder disease. 6. Acute abdomen (not due to gall-bladder disease). Pictures were taken and activity-time curves of "regions of interest" were generated from the computer data. From these the presence or absence of a gall-bladder image was easily determined. The gall bladder was visualized in all normals but in none of the patients with acute gall-bladder disease. In the group with an acute abdomen suggestive of acute gall-bladder disease, but subsequently shown to be otherwise, the gall bladder was visualized in all cases. The gall bladder was not visualized in 42% of hepatocellular disease patients, nor in any of those with biliary obstruction, due to poor uptake or poor secretion of the HIDA. In cases of chronic gall-bladder disease, visualization of the gall bladder corresponded with gall-bladder opacification on the oral cholecystogram; in these cases the HIDA scan offers no advantage over the oral cholecystogram. These results suggest that in cases of "acute abdomen" an absent gall bladder image with a normal hepatogram will strongly support the diagnosis of acute gall-bladder disease, and that visualization of the gall bladder excludes such a diagnosis, making the HIDA scan a useful first-line investigation in these patients.

Three cases of spontaneous duodeno-colic fistula.

Three cases of duodeno-colic fistula are presented, where a communication was demonstrated between the anterior aspect of the third part of the duodenum and the transverse colon at the point of mesocolic attachment. At operation the fistulae were found to be some 6 to 9 cm in length, and histological examination showed a well marked muscular layer with an intact epithelium. In view of the absence of any explanatory pathology, an embryological basis is suggested as the likeliest explanation for their origin.

Is there an antral-body portal system in the stomach?

The direction of blood flow from the gastric mucosa of the antrum of the rat stomach has been studied using the isotope Rb86Cl. In a series of five experiments radioactivity has been shown to be transported via the blood stream from the antrum to the parietal cell mass without passing through the general circulation first. It is suggested that a 'portal' or direct transport system from antral mucosa to the body of the stomach exists.

A non-invasive test of gastric function.

Using 98Tcm a non-invasive test of gastric function has been developed which completely obviates the need for a nasogastric tube and which adds to the accuracy of existing tests by overcoming losses due to incomplete aspiration or gastric emptying. 99Tcm is handled by the stomach like Cl-, the gastric secretion of which is equal to that of H+. The value of the pentagastrin stimulation test in the presence of varied gastric pathology is discussed in relation to 50 patients. Other possible diagnostic uses of the test are evaluated and a method of carrying out an insulin test by a modification of the technique is described.

Revagotomy for recurrent peptic ulceration.

A review has been made of 59 patients with recurrent peptic ulceration after incomplete vagotomy. Eighteen transthoracic procedures were performed, the remainder having abdominal revagotomy. An antrectomy was also carried out in 10 of these patients. An intact posterior nerve trunk was the most common operative finding and when either an anterior trunk or nerve strands only were present there was less likely to be an early positive insulin response (P = 0.033). Following incomplete vagotomy a longer period of symptomatic relief is obtained when gastro-enterostomy rather than pyloroplasty is used as the drainage (P less than 0.01). Completing the vagotomy by the abdominal route gave superior results to transthoracic revagotomy (P = 0.0015), the former procedure without antrectomy having no associated mortality in this series. Although the results of revagotomy and antrectomy are as good as those of transabdominal revagotomy alone, we recommend the latter more conservative treatment for recurrent ulceration after incomplete vagotomy.

Effects of partial surgical pancreatectomy in rats. I. Pancreatic regeneration.

The capacity for pancreatic regeneration in male Wistar rats of average weight 176 g was determined after surgical resection of 50, 70, or 90% of the pancreas. In control animals of this weight pancreatic growth was still taking place but ceased after 2 months. Growth of the residual pancreas in resected animals over this period was greater than in controls and the final weight of the residual pancreas was 21, 32, and 78% greater than that of the corresponding segments in sham-operated animals after 50, 70, and 90% resection respectively. Proliferation of acinar cells was assayed by autoradiographic detection of tritiated thymidine incorporation in controls and after 90% resection. Proliferation of acinar cells in control animals during the first 2 weeks of the experiment was significantly higher than at later times when it fell to very low levels. Proliferation in 90% resected animals was markedly higher than in controls from 2 to 5 days after resection and, together with the limited hypertrophy occurring at this time, adequately accounted for the increase in weight of the residual pancreas during the first 2 weeks. We were unable to explain the increase in pancreatic weight in control or resected animals between 2 weeks and 2 months either in terms of hypertrophy or hyperplasia of acinar cells.

Personal experience in the surgical management of carcinoma of the stomach.

A consecutive series of 226 cases of carcinoma of the stomach has been studied. The policy of treatment has been consistent throughout and laparotomy was performed in 96-5 per cent of cases. The follow-up has been studied with regard to duration of symptoms, location and degree of spread of the tumour and different forms of operative treatment. Although Billroth I gastrectomy gave a 32 per cent 5-year survival rate for the less advanced tumours the overall survival remains, as in other series, depressingly low (8-5 per cent). Education of the public to present early would not appear to help the situation as survival was directly proportional to the duration of symptoms.

The value of the radio-isotope hepatogram in the jaundiced patient.

The distinction between 'medical' and 'surgical' jaundice is often difficult due to the lack of specificity of biochemical liver function tests, and the difficulty in assessing hepatocellular function and biliary tract patency in the jaundiced patient. We present a noninvasive isotopic technique which gives reliable information on these parameters, resulting in a high degree of accuracy in the classification of jaundice. 131I Rose Bengal, which is handled by the liver like bromsulphthalein, is administered intravenously and count rates during hepatic uptake and biliary excretion are recorded over the liver, biliary tract and duodenum using a gamma camera/computer system, into which is built an electronic light pen, so that particular areas of interest can be studied. Blood clearance of the iostope is simultaneously measured, and from these data the T 1/2 of uptake, the plasma retention and the excretion quotient are determined. The results of the first 80 examinations show that by qualitative assessment of the uptake and excretory phases of the 'hepatogram' and by determination of the T 1/2 and excretion quotient, jaundice has been classified with an 86 per cent accuracy in cases where the diagnosis is not apparent from clinical and biochemical data. The T 1/2 of uptake correlates well with bromsulphthalein retention in the non-jaundiced patient, and when applied to patients with obstructive jaundice enables the progress of hepatocellular impairment with time to be studied, and its recovery after relief of the obstruction. Preliminary results suggest that the technique may also have applications in the study of biliary tract dynamics in patients with post-cholecystectomy syndromes and relapsing acute pancreatitis.

Observations of gastric mucosal blood flow using 99Tcm in rat and man.

The 99Tcm clearance technique is shown to be a useful method of assessing gastric function. It is easily carried out and is relatively non-toxic--the dose of isotope could be reduced to 100 muCi or less without sacrificing the accuracy of the investigation. Although the results are preliminary and the number of cases investigated so far is small, they suggest that the measurement of pertechnetate clearance is directly related to gastric mucosal blood flow; it is a useful parameter of gastric function and may well prove to be a more accurate discriminant in cases of peptic ulceration than the conventional measurement of gastric acid secretion.

Effect of secretogogues on mucosal blood flow in the antrum and corpus of the stomach.

Gastric mucosal blood flow in the rat was determined by the indicator fractionation technique of Sapirstein using Rb86Cl. Antral and corpus flow rates were determined in response to increasing doses of pentagastrin and histamine and the effect of vagotomy was determined. With progressive stimulation the antral:corpus flow ratio increased with both stimulants; however, vagotomy and noradrenaline reduced blood flow in both areas of mucosa. It is concluded that the antrum, as well as the corpus, actively responds to secretory stimulants by an increase in mucosal blood flow and support is provided for the theory that the antrum plays an active role in the control of parietal cell blood flow and secretion.

Should cholecystectomy be combined with vagotomy and pyloroplasty?

Duodenal ulcers and gallstones, two of the commonest surgical conditions, affect respectively 10% of men and up to 20% of the population. Although many detailed studies of the treatment of these conditions have been conducted, there is no report of the results of surgery when the conditions coexist. 60 patients who had undergone vagotomy, pyloroplasty, and cholecystectomy were compared with age and sex matched controls who had undergone vagotomy and pyloroplasty alone or cholecystectomy alone. In the early postoperative period after the combined procedure there was a very high incidence of post-vagotomy diarrhoea (48.3%, P equal to 0.00013) and bile-reflux gastritis. The findings implicate bile-acids--their excretion and handling by the small intestine--in the aetiology of post-vagotomy diarrhoea. Where the conditions coexist truncal vagotomy and pyloroplasty should be avoided in the treatment of the duodenal ulcer because of the risk of post-vagotomy diarrhoea and bile-reflux gastritis.