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Background. South Africa's regulatory framework for electromagnetic medical devices has come under considerable criticism. Here it is reviewed in terms of how it has given form to protective measures against ionising radiation. The Hazardous Substances Act provides for effective protection against radiation, but has been undermined by poor administration and uncertainty about regulations and licensing conditions. The legal weight of enforcing licensing conditions through a website without proper consultation with all parties concerned is questionable and ineffective. Effective and legal radiation control is possible by activating the National Advisory Committee on Electronic Products, provided for in Regulation R326 published in 1979, but this has never been implemented. The possible impact of annual quality assurance tests currently enforced through licensing conditions on radiation dosage to the population is not cost-effective, as new training and accreditation structures have to be created.Conclusions. That more than 80% of overexposures are generally caused by human error is a clear indication that training of the regular users of X-ray equipment should be emphasised, and not the training and accreditation of the technicians responsible for a single quality assurance test per year. Constructive engagement with the professional bodies involved in the medical use of X-rays through a National Advisory Committee on Electronic Products may be a cost-effective solution for lowering radiation dosage to the population. [ABSTRACT FROM AUTHOR]

No study has reported an association between gastroesophageal reflux disease (GERD) or its therapies and gallbladder function. We compared pre- and postoperative gallbladder function in patients undergoing fundoplication to determine the following: (1) whether patients with chronic GERD have preexisting gallbladder motor dysfunction; (2) whether medical or surgical therapy alters gallbladder function; and (3) whether division of the hepatic branch of the anterior vagus nerve is detrimental to gallbladder motility. Nineteen patients with documented GERD consented to a preoperative cholecystokinin-stimulated technetium hepatobiliary (CCK-HIDA) scan to quantify the gallbladder ejection fraction (GBEF). All patients underwent laparoscopic Nissen fundoplication. One month after fundoplication, 12 patients completed a repeat CCK-HIDA scan for determination of GBEF, with comparison to the preoperative GBEF. Among patients with preoperative GERD, 11 (58%) of 19 met the scintigraphic criteria for gallbladder dysfunction (GBEF <35%), which is a ratio comparable to that in patients undergoing a CCK-HIDA scan for presumed biliary dyskinesia during the same time period (31 [60%] of 53; P = NS, chi-square test) and exceeds the rate of abnormal GBEF reported in healthy volunteers (3%). Six of seven patients with a low preoperative GBEF who underwent repeat evaluation postoperatively had normalization of the GBEF (P < 0.05, paired t-test). In the 12 patients who underwent postoperative CCK-HIDA scanning, there was no association between preservation or division of the hepatic branch of the anterior vagus nerve and postoperative gallbladder dysfunction (P = NS, chi-square test). Unexpectedly, 58% of patients with GERD demonstrated gallbladder motor dysfunction prior to fundoplication, with improvement to normal occurring in most of those studied postoperatively. These data support controlled trials to determine the effect of chronic GERD and antisecretory therapy on gallbladder and global gastrointestinal smooth muscle function. Preservation of the hepatic branch of the anterior vagus nerve during fundoplication offered no clear benefit with regard to early postoperative gallbladder function. ( J Gastrointest Surg 2002;6:806–811.) [Copyright &y& Elsevier]

Nisoldipine is a newly developed calcium channel blocker with outstanding vasodilatory properties especially with regard to the coronary arteries. Thus it may find wide-spread application as a therapeutic agent in various ischemic heart disease syndromes. The purpose of this study was to evaluate the effect of nisoldipine on the diastolic function of the left ventricle (LV) in the clinical situation. A patient group on nisoldipine treatment was compared to a control group. In the nisoldipine group a maximum decrease of 17 mmHg in the mean systolic blood pressure with an increase in the mean peak ejection rate (0.78 EDV/s) and peak filling rate (0.52 EDV/s) were observed. Mean LV ejection fraction increased by 6.4% and the time to peak filling rate decreased by 36.5 ms. After eight weeks of treatment the acute effects of nisoldipine were similar to the previous study. Nisoldipine therefore tends to improve both the diastolic and systolic function of the left ventricle. [ABSTRACT FROM AUTHOR]

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To determine whether exposure to proximal intestinal contents per se is an adequate stimulus for ileal adaptation of the magnitude seen after jejunectomy, rats were prepared by transposing 30 cm of distal ileum to the duodenojejunal junction or by sham operation. One month after surgery, mucosal mass (wet weight, protein content, and DNA content) and digestive enzyme activities were measured in segments of small intestine and compared between the groups. Measurements of mucosal mass in transposed ileum more than doubled those in control jejunum (p <0.001). Mean enzyme activities/cm bowel length in transposed ileum approached or surpassed measurements in control jejunum. In contrast to the other enzymes studied, mean sucrase specific activities were similar in transposed ileum and control jejunum, values five fold greater than that of control ileum (p <0.002). We conclude that exposure of ileum to proximal intestinal contents reproduces the adaptive response that follows jejunectomy, without requiring short bowel. Sucrase responds to this exposure in a unique fashion. [ABSTRACT FROM AUTHOR]

A method for obtaining left ventricular (LV) volume curves, synchronized with average LV pressure (LVP) curves for calculation of LV contractility, is described. Multiple gated blood pool imaging was performed to calculate average LV volume curves. Simultaneously with this acquisition, LVPs and aortic pressures were measured by indwelling catheters and recorded on an FM tape recorder. These signals were fed to the computer as image information and averaged and processed by the software developed for this purpose. Pressure resolution of the calibrated images was 4 mmHg/pixel when provision was made for a maximum pressure of 200 mmHg. A good correlation ( r=0.99) was obtained between the calculated peak LVPs and mean peak LVPs read from the chart recorder. The regression equation was: digitized peak LVP=1.04xchart recording-5.11 mmHg and the standard error of the estimate was 2.9 mmHg. Similar results were obtained with the aortic pressure (AP) measurements (digitized AP=0.94 x chart recording+6.37 mmHg, the standard error of the estimate was 3.8 mmHg). The digitized data also allowed the construction of pressure-volume loops for interpretation of ventricular contractility. [ABSTRACT FROM AUTHOR]

Nisoldipine (BAY k 5552) like nifedipine, is a dihidropyridine compound with strong calcium blocking activity. The purpose of this study was to measure and compare the absolute hemodynamic effects of these two drugs before and at 30 min, 60 min and 120 min after oral intake in 20 ischemic heart disease patients with radionuclide gated cardiac scintigraphy. No significant change was seen in end diastolic volume index with either of the drugs. With nifedipine the stroke volume index (SVI) increased significantly from the basal value at 30 min ( P=0.004) and 60 min ( P=0.034) yet not significantly at 120 min. The same trend was seen in left ventricular ejection fraction (LVEF) with significant increases at 30 min ( P=0.02) and 60 min ( P=0.025) yet not at 120 min. The cardiac index increased significantly at 30 min ( P=0.001), 60 min ( P=0.002) and 120 min ( P=0.025) but the latter value was significantly lower than the 30 min value indicating the maximal effect had already passed. With nisoldipine the SVI increased significantly at 60 min ( P=0.004) and 120 min ( P=0.001) but not at 30 min. These changes were again reflected by a significant increase in LVEF at 60 min ( P=0.021) and 120 min ( P=0.002) without significant increase at 30 min. The increase in CI was highly significant at 60 min ( P=0.003) and 120 min ( P=0.001) without significant change at 30 min. Nisoldipine proved to be a potent calcium antagonist with slower onset and longer duration of action than nifedipine. [ABSTRACT FROM AUTHOR]

A radionuclide washout technique (WO), for calculation of the right ventricular ejection fraction (RVEF) which is independent of the exact position of the right ventricular region of interest was evaluated and results compared with first pass (FP) and equilibrium gated blood pool (GBP) values. Regression analysis between RVEF values of 24 patients obtained from FP and WO yielded a correlation coefficient ( r) of 0.89, while a slightly poorer correlation coefficient was obtained when FP and GBP were compared ( r=0.79) and between WO and GBP ( r=0.71). No significant difference between RVEF values calculated from the three techniques was found ( P<0.05) on inter- and intraobserver level. The radionuclide washout technique yields an accurate determination of RVEF without the necessity of outlining the RV accurately. [ABSTRACT FROM AUTHOR]

Chronically ill and neurologically impaired children may require enteric tube feedings indefinitely to maintain adequate nutrition. When transgastric feedings are not feasible, a permanent feeding jejunostomy may be required. Since 1979, we have constructed a continent feeding jejunostomy in 16 children using a shortened Maydl Roux-en-Y limb with an intussuscepted nipple-valve mechanism. The jejunostomy is matured as a stoma through the abdominal wall, while the nipple valve is stabilized in the abdominal cavity anchored to the posterior fascia and peritoneum. Bolus or drip feedings can be initiated when gastrointestinal function resumes. Between feedings, the tube is removed as the jejunostomy is continent and can be covered with a gauze pad. No deaths were attributed to the operation, although more than 50% of these children died within 2 years from complications of their primary disease. The jejunostomy functioned well and was completely continent in 14 patients. The creation of a feeding jejunostomy with an intussuscepted nipple valve assures continence, avoids the complications of chronic indwelling tubes, and decreases the risk of regurgitation. Furthermore, the continent jejunostomy permits bolus feedings and requires minimal care. The use of this procedure is advocated whenever permanent feeding jejunostomy is anticipated. [ABSTRACT FROM AUTHOR]