Cholecystoduodenocolic fistula and gallstone ileus

A patient with cholecystoduodenocolic fistula and gallstone ileus is described. Barium enema and barium meal and follow through demonstrated the passage of the gallstone from the gallbladder region to the small bowel. The clinical features and operative management are discussed in the light of four previously recorded cases.

Diagnosis of deep-vein thrombosis: comparison of clinical evaluation, ultrasound, plethysmography, and venoscan with X-ray venogram

In 50 patients with suspected deep-vein thrombosis the diagnostic accuracy of standardised clinical examination, doppler ultrasound, impedance plethysmography, and technetium-99m-labelled-fibrinogen scintigraphy (venoscan) was compared with that of X-ray venography. Physical examination was the least accurate method. Impedance plethysmography, venoscan, and ultrasound had accuracies of 65%, 80%, and 82%, respectively. The initial X-ray venogram report had an accuracy of 90% compared with the interpretation of two experienced radiologists. The venoscan was equivocal in 32% of patients, and in the remaining patients the accuracy was 97%. Objective methods of investigation are essential for diagnosing deep-vein thrombosis. Of those tested, the X-ray venogram was the only investigation suitable for definitive diagnosis. The venoscan may have a role as a screening procedure, to be followed by X-ray venography in patients with equivocal venoscan results.

Weighted averaging--theory and application to electric response audiometry

A weighted averaging technique has been developed to overcome the shortcomings of conventional, unweighted averaging in the case of nonstationary noise. The technique is based on the linear least-mean-square estimate of a periodic signal in a simple model of non-stationary noise. This estimate weights each recorded epoch according to the magnitude of the noise within the epoch. In the estimation of a known signal, the weighted averaging procedure yielded smaller root-mean-square errors in comparison with the normal unweighted average. The weighted averaging procedure offers many advantages over conventional averaging or averaging with automatic gain control preamplifiers.

Monitoring response to chemotherapy of intact human tumours by 31P nuclear magnetic resonance

10 kidneys bearing adenocarcinoma (hypernephroma), 1 ureteric tumour, 2 Wilms' tumour from patients undergoing nephrectomy, and normal human and animal kidneys were preserved and later tested to see whether normothermic blood perfusion restored glomerular filtration, oxygen consumption, and energy metabolism, as monitored by 31P nuclear magnetic resonance (NMR). NMR spectra of normal human kidney and of renal tumours were characteristic of kidney in other species (rat, rabbit, and dog), with six principal resonances assigned to adenosine monophosphate, inorganic phosphate (Pi), glycerophosphoryl choline, gamma, alpha, and beta adenosine triphosphate and an intrarenal pH 7.0-7.2. 7 out of 9 hypernephromas and 1 of the 2 Wilms' tumours produced an additional resonance at +4.2 ppm. This peak was absent from all normal kidney spectra and may represent Pi in a specific and highly acidic environment (pH 6.1-6.5) found in actively metabolising human tumours. Furthermore, in 1 tumour (out of 5 tested) the +4.2 ppm peak rose rapidly after the addition of chemotherapeutic agents to the perfusing blood. This observation may indicate drug sensitivity of this one tumour. The results suggest that 31P NMR imaging may be used to monitor therapeutic response during regional perfusion of malignant tumours in man.

Coughs cause systemic blood flow

Although it is known that rhythmic coughing can preserve consciousness during ventricular fibrillation, the arterial pressure transients which result have not yet been shown to reflect forward blood flow in man. The effectiveness of cough in causing forward flow in eight normal volunteers with bradycardia was studied. They coughed between cardiac cycles, using an audio and visual display of the electrocardiogram. The force of the cough was varied and measured with an oesophageal balloon. Blood flow was recorded with a Döppler velocity probe over the radial artery and a finger or ear photoplethysmograph. Motion artefact on the Döppler record due to coughing was excluded by transiently obstructing the brachial artery. We compared the areas under 5-10 consecutive Döppler and photoplethysmograph pulse flow tracings due to the cough and heart beat with those due to the immediately preceding heart beat alone. They were significantly increased. This augmentation was greater in those flow pulses accompanied by a more vigorous cough. It is concluded that coughing is associated with an effort dependent forward flow pulse in the arterial circulation.

Should surgeons operate on the evidence of ultrasound alone in jaundiced patients?

The biliary ultrasound scans of 132 patients having a laparotomy for jaundice have been reviewed to assess the role of ultrasound in the selection of patients for surgery. When scans were technically satisfactory the finding of a dilated extrahepatic duct (EHD) indicated obstructive jaundice in all cases, but the obstructing lesion in 5 per cent of such cases was too proximal for jaundice to be relieved by direct surgical decompression. Scans were further classified on the basis of abnormalities detected in the gallbladder. When EHD dilation was associated with gall bladder findings 'typical' of distal common bile duct (CBD) obstruction due to gall stones (small gallbladder with multiple gallstones) or tumour (dilated gallbladder without gallstones), surgically remediable obstruction was always present. Although ultrasound identified the obstructing lesion itself in a minority of cases, the cause of obstruction could be correctly inferred in 95 per cent of 'typical' scans. These results suggest that it is safe to proceed directly to surgery only when an experienced ultrasonographer demonstrates findings 'typical' of distal CBD obstruction due to gallstones or tumour.

Energetics of sodium transport in the kidney. Saturation transfer 31P-NMR

31P-NMR has been used to quantify inorganic phosphate (Pi) and high-energy phosphates in the isolated, functioning perfused rat kidney, while monitoring oxygen consumption, glomerular filtration rate and sodium reabsorption. Compared with enzymatic analysis, 100% of ATP, but only 25% of ADP and 27% of Pi are visible to NMR. This is indicative that a large proportion of both ADP and Pi are bound in the intact kidney. NMR is measuring free, and therefore probably cytosolic concentrations of these metabolites. ATP synthesis rate, measured by saturation transfer NMR shows the P:O ratio of 2.45 for the intact kidney. This is close to the theoretical value, suggesting the NMR visible pool is that which is involved in oxidative phosphorylation. The energy cost of Na transport, calculated from the theoretical Na:ATP of 3.0 exceeded the measured rate of ATP synthesis. Instead, Na:ATP for active transport in the perfused kidney was 12. Since the phosphorylation potential ( [ATP]/[ADP]X[Pi] ) by NMR was 10 000 M-1, the free-energy of ATP hydrolysis was 52 kJ/mol. Using this figure, the rate of ATP hydrolysis observed could fully account for the observed rate of sodium reabsorption.

Examination of a myopathy by phosphorus nuclear magnetic resonance

A 16-year-old boy with myopathy, ophthalmoplegia, and raised basal metabolic rate was examined by the non-invasive technique of phosphorus-31 nuclear magnetic resonance (31 P NMR). The muscles of the forearm showed an abnormal 31P NMR spectrum with a high inorganic phosphate (Pi) content in relation to phosphocreatine (PCr) (PCr/Pi = 4; control = 10). This finding was compatible with the abnormality of mitochondrial function already established by biopsy and offers in addition an explanation for the raised oxygen consumption in this patient. The method of 31P NMR is suited to rapid non-invasive diagnosis in various muscle disorders.

Effects of a six-week drug holiday on symptom status, relapse, and tardive dyskinesia in chronic schizophrenics

We have conducted a 6-wk drug withdrawal study in a group of chronic schizophrenic outpatients who had been maintained on injectable fluphenazine decanoate for at least 2 yr prior to the study. After two baseline assessments, patients were randomly assigned to two groups. The first group (holiday) received a placebo injection from a nurse who was not involved in the assessment (N = 17). The second group continued on their regular medication (N = 14). The assessment was done in a double-blind fashion at 3 and 6 wk using the Schedule for Affective Disorders and Schizophrenia (SADS) and the Global Assessment Scale (GAS) inventories to assess symptom status. Tardive dyskinesia was measured using the Abnormal Involuntary Movement Scale (AIMS). Community adjustment was assessed by means of the self-rated Weissman Social Adjustment Scale. We found that there were no relapses of any kind in either group of patients using the instruments mentioned above. The prevalence of tardive dyskinesia as measured by the AIMS was low, with only one patient having severe tardive dyskinesia. There was no significant worsening of the tardive dyskinesia during the drug holiday. Our study concludes that a 6-wk drug holiday was safe in this group of chronic schizophrenic patients maintained on fluphenazine decanoate. In contrast to other studies, no cases of covert tardive dyskinesia were detected during the drug holiday.

Role of the malate--aspartate shuttle in renal sodium transport in the rat

1. Experiments were designed to establish the relationship between renal gluconeogenesis and sodium transport. Six inhibitors of gluconeogenesis, with different sites of action, were tested in the isolated perfused rat kidney in which renal function, and in particular Na+ reabsorption, was followed. 2. In kidneys from fed or starved rats specific inhibitors of gluconeogenesis neither inhibited nor stimulated Na+ reabsorption; gluconeogenesis and sodium reabsorption are therefore independent of one another under these conditions. 3. Inhibitors of transaminase or malic dehydrogenase inhibited gluconeogenesis from lactate and pyruvate respectively; the transaminase inhibitor significantly inhibited oxidation of lactate and glucose. 4. Sodium reabsorption was inhibited by a transaminase inhibitor when glucose or lactate was the sole substrate, and by inhibition of malic dehydrogenase when pyruvate was the substrate. 5. These results indicate that the malate--aspartate shuttle controls Na+ reabsorption in the intact kidney by regulating substrate oxidation (and the provision of energy) rather than by any direct involvement of gluconeogenesis in Na+ transport.

Paired-ion chromatography and high performance liquid chromatography of labetalol in feeds

A high performance liquid chromatographic (HPLC) method using reverse phase paired-ion chromatography and ultraviolet detection at 280 nm has been developed to determine labetalol, an alpha and beta adrenoceptor blocking agent, in Purina No. 5001 rodent chow. The method is simple and rapid, and demonstrates a separation technique applicable to other acidic and basic drugs. It requires only extraction of the drug with methanol--water--acetic acid (66 + 33 + 1) and separation of insoluble material by filtration before HPLC. Labetalol, is chromatographically separated from soluble feed components by means of a microBondapak C18 column and methanol--water--acetic acid (66 + 33 + 1) mobile phase, 0.005M with respect to sodium dioctylsulfosuccinate paired-ion reagent. Average recovery is 98.7% with a relative standard deviation of +/- 2.3% for the equipment described.