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Biomedical subjects

D Ward

Publications and source records attributed to D Ward.

At least 199 records · Page 11Linked to original sources
PubMed1982

Syncope caused by cough-induced complete atrioventricular block.

Cough syncope is a well-recognized syndrome in which loss of consciousness follows a bout of prolonged coughing. The pathophysiology of this syndrome has been attributed to lowered cerebral perfusion pressure consequent on an increased intrathoracic pressure, which lowers cardiac output (by a Valsalva mechanism) and impairs cerebral venous return. We report a case of cough-induced syncope in which ECG monitoring showed that coughing produced paroxysmal atrioventricular block with ventricular asystole. Such a case has not previously been documented.

Adie Syndrome↗
PubMed1981

Phenylclindine-induced alteration in rat muscarinic cholinergic receptor regulation.

A muscarinic cholinergic receptor binding profile was performed on 3 separate regions of the rat brain following administration of the drug phencyclidine (10 mg/kg, twice a day) for 10 days. Binding assays were performed on homogenates of the hippocampus, striatum and cortex using the ligand [3H]QNB. Scatchard analysis of the binding data revealed a statistically significant decrease in the number of [3H]QNB binding sites in all phencyclidine treated animals. Binding was 22% lower in the cortex and 16% lower in the hippocampus and striatum. Phencyclidine treatment did not significantly alter the affinity of the receptor for the ligands [3H]QNB, acetylcholine or phencyclidine. This decrease in CNS muscarinic receptors could be contributing to the underlying biochemical mechanism of tolerance to the drug.

Animals↗
PubMed1981

The efficacy of 5-fluorouracil, mitomycin C, and methyl CCNU in advanced gastrointestinal malignancy.

50 patients with advanced gastrointestinal malignancies were treated with 5-fluorouracil (5FU), 1-(2-chloroethyl)3-(4-methylcyclohexyl)-1-nitrosourea (MeCCNU) and mitomycin C (Mito C). 43 patients, with diagnoses of colorectal, pancreatic or gastric cancer, were evaluable. 13 patients (30%) achieved complete remissions, and 4 achieved partial remissions. The median durations of responses in colorectal, pancreatic and gastric disease were 11.0, 11.0, and 11.5 months, respectively. Survival was definitely prolonged in responding patients with pancreatic and gastric carcinomas. The combination was well tolerated. Mucositis, leukopenia, and thrombocytopenia were the major toxicities that occurred. The quality of life was improved in all responding patients.

Adenocarcinoma↗
PubMed1980

Ambulatory evaluation of nephrolithiasis. Classification, clinical presentation and diagnostic criteria.

Using the ambulatory protocol previously described, 241 patients with nephrolithiasis were evaluated. They could be categorized into 10 groups from the results obtained. Absorptive hypercalciuria type I (87 per cent male) comprised 24.5 per cent and was characterized by normocalcemia, normal fasting urinary calcium (less than 0.11 mg/100 ml glomerular filtration), an exaggerated urinary calcium following an oral calcium load (greater than 0.20 mg/mg creatinine), normal urinary cyclic adenosine monophosphate (AMP) (less than 5.4 nmol/100 ml glomerular filtration) and serum parathyroid hormone (PTH), and hypercalciuria (greater than 200 mg/day during a calcium- and sodium-restricted diet). Absorptive hypercalciuria type II (50 per cent male) accounted for 29.8 per cent; its biochemical features were the same as those for absorptive hypercalciuria type I, except for normocalciuria during a restricted diet and low urine volume (1.42 +/- 0.55 SD liter/day). Renal hypercalciuria (56 per cent male), disclosed in 8.3 per cent, was represented by normocalcemia and high values for fasting urinary calcium (0.160 +/- 0.054 mg/100 ml glomerular filtration), urinary cyclic AMP (6.80 +/- 2.10 nmol/100 ml glomerular filtration) and serum PTH. Primary hyperparathyroidism (57 per cent female), accounted for 5.8 per cent, typically included hypercalcemia, hypophosphatemia, hypercalciuria and high urinary cyclic AMP. Hyperuricosuric calcium urolithiasis (100 per cent male) comprised 8.7 per cent, and was characterized by hyperuricosuria (776 +/- 164 mg/day) and urinary pH exceeding pK for uric acid (5.91 +/- 0.33). In enteric hyperoxaluria (60 per cent female), encountered in 2.1 per cent of cases, urinary oxalate was increased (6.29 +/- 13.2 mg/day). Noncalcium-containing stones were found in 2.1 per cent of the patients with uric acid lithiasis (100 per cent male) and in another 2.1 per cent of the patients with infection lithiasis (60 per cent female). These conditions were typified by low urinary pH (5.29 +/- 0.12) and high urinary pH (6.69 +/- 1.16), respectively. Renal tubular acidosis was found in one patient (male, 0.4 per cent). In 10.8 per cent of the patients (81 per cent male), no metabolic abnormality could be found, although urine volume was low (1.41 +/- 0.51 liter/day). Hypercalciuria could not be differentiated between absorptive hypercalciuria and renal hypercalciuria in 5.4 per cent of the patients. Thus, this ambulatory protocol disclosed a physiologic disturbance in nearly 90 per cent of the cases and provided a definitive diagnosis in 95 per cent of the patients.

Adult↗
PubMed1980

Treatment of chronic atrial fibrillation in the elderly, assessed by ambulatory electrocardiographic monitoring.

This study concerns 8 elderly patients with age-related chronic atrial fibrillation that required control of the ventricular response. The effects of oral administration of placebo, pindolol, verapamil, digoxin and digoxin + pindolol were assessed (each for a week) during three daily activity and sleep sessions, over a six-week period. Cardiac rhythm was monitored by taped electrocardiograms. Either digoxin or pindolol was effective, but digoxin was the best tolerated of all the drugs. A combination of pindolol and digoxin reduced the maximum ventricular rate without further depression of the minimum ventricular rate. Digoxin seems to be well tolerated in the control of atrial fibrillation in the elderly, and beta blockade may be a useful therapeutic adjunct.

Aged↗
PubMed1980

Response of atrial flutter to overdrive atrial pacing and intravenous disopyramide phosphate, singly and in combination.

Ten patients who suffered spontaneous paroxysms of atrial flutter were investigated by electrophysiological techniques. Two had overt Wolff-Parkinson-White syndrome; three Lown-Ganong-Levine syndrome; and one a concealed accessory atrioventricular connection. Atrial flutter was initiated, at study, by right atrial pacing and electrograms from the right atrium and coronary sinus were observed for at least five minutes to ensure stable flutter in both atria. Atrial flutter was terminated by 2.5 s or 5 s bursts of atrial pacing at rates 10, 50, or 100 beats/min faster than the intrinsic flutter rate in only two patients. Atrial flutter, which was reinitiated in two patients, was then treated with intravenous disopyramide phosphate, 2 mg/kg body weight, infused over five minutes. In all 10 patients the atrial rate slowed from a mean of 310 +/- 39 beats/min to 217 +/- 27 beats/min and atrial flutter terminated in one case. Though the mean ventricular rate fell from 161 +/- 52 beats/min to 156 +/- 45 beats/min the atrioventricular conduction ratio fell from 2.17 +/- 0.86 to 1.55 +/- 0.59 and four patients were left with symptomatically significant increases of ventricular rate. In seven of nine patients overdrive atrial pacing, repeated after disopryamide, resulted in the conversion of atrial flutter to sinus rhythm. In this study, overdrive atrial pacing and intravenous disopyramide, singly and in combination, terminated atrial flutter in nine of the 10 patients and it is suggested that this method may provide an effective alternative to direct current cardioversion.

Adult↗
PubMed1980

A microcomputer-based tachycardia termination system--a preliminary report.

A microprocessor-based system is described which employs the autodecremental mode of atrial pacing. Preliminary experience suggests that this modality of pacing retains the advantages of rapid asynchronous atrial pacing but reduces the risk of provoking resistant atrial tachyarrhythmias. If the technique continues to prove successful it is suitable for incorportation into a fully implantable pacemaker.

Cardiac Pacing, Artificial↗
PubMed1980

Beyond permanency planning.

With permanency planning taking the spotlight increasingly in the field of foster care, it becomes urgent to examine the definition of permanency, the effect on practice, and the implications for service delivery.

Child↗
PubMed1979

The effect of intravenous disopyramide phosphate on recurrent paroxysmal tachycardias.

1 Reccurent paroxysmal atrial, atrioventricular and ventricular tachycardias in 50 patients without acute coronary insufficiency, heart failure or metabolic abnormlity were treated with disopyramide phosphate in a dose of 2 mg/kg body weight infused over 5 min. 2 Conversion to sinus rhythm within 10 min of the completed infusion occurred in 10 of 14 (71%) patients with paroxysmal 'lone' atrial fibrillation, 3 of 7 (43%) patients with paroxysmal atrial flutter, 6 of 9 (67%) patients with paroxysmal atrial tachycardia, 5 of 9 (56%) patients with paroxysmal atrioventricular tachycardia associated with the Wolff-Parkinson-White syndrome and 8 of 11 (73%) patients with paroxysmal ventricular tachycardia. 3 Side effects: significant systemic hypotension in 3, high grade AV block in 1, an increased ventricular response producing symptoms in 4, post conversion asystole in 1 land sinus bradycardia in 2. 4 The anti-arrhythmic effect and arrhythmogenic side effects may be related to both the direct membrane stabilizing effect and the anticholinergic effect of disopyramide.

Atrial Fibrillation↗
PubMed1979

Intravenous disopyramide phosphate and ventricular overdrive pacing in the termination of paroxysmal ventricular tachycardia.

Both antiarrhythmic drugs and bursts of rapid ventricular pacing provide alternatives to DC cardioversion for the treatment of paroxysmal ventricular tachycardia. This report considers the individual and combined success of burst ventricular pacing and intravenous disopyramide phosphate in the tretment of 11 examples of paroxysmal ventricular tachycardia. Rapid ventricular pacing, at a rate of up to 50 beats/min faster than the tachycardia rate terminated 7 of the tachycardias. Intravenous disopyramide resulted in increased tachycardiac cycle length (342 +/- 34 ms-385 +/- 56 ms), increased QRS complex width (147 +/- 42 ms-180 +/- 41 ms) and termination of 8 the tachycardias. The remaining 3 tachycardias could be terminated by bursts of ventricular pacing following the infusion of disopyramide. Of these, 2 could not be terminated prior to disopyramide. The use of both techniques allowed the extinction of all 11 tachycardias and prevented the need to proceed to DC conversion.

Adult↗
PubMed1979

Modulation of the properdin amplification loop in membranoproliferative and other forms of glomerulonephritis.

The mean serum concentrations of C3b inactivator (C3bINA) and beta1H globulin were measured in eighty-six sera (thirty-five membranoproliferative, thirteen membranous, thirty-one focal and seven minimal change) taken from seventy-five patients with histologically diagnosed glomerulonephritis. In none of the four groups of sera did the mean concentrations of both these proteins differ significantly from the mean levels in a group of fifty normal sera. However, in the membranoproliferative group, the mean level of C3bINA, but not beta1H, was significantly lower in the nephritic factor positive than in the nephritic factor negative group. When the eighty-six sera were considered together, serum concentrations of C3bINA and beta1H correlated with levels of C3, factor B, properdin and C4. When the membranoproliferative group was considered separately, C3bINA levels correlated with levels of C3, factor B, properdin and C4 and beta1H correlated with C3 and factor B, but not properdin or C4 in the nephritic factor negative group, but no such correlations were observed in the nephritic factor positive group. The significance of these findings is discussed in the light of current thoughts on the mechanisms of modulation of the alternative pathway.

Beta-Globulins↗
PubMed1977

Ligand binding to muscarinic receptors in intact longitudinal muscle strips from guinea-pig intestine.

1 The binding of ligands to muscarinic receptors in intact longitudinal muscle strips from guinea-pig small intestine has been determined by measuring the inhibition of the irreversible binding of [3H]-propylbenzilylcholine mustard ([3H]-PrBCM). 2 The IC50 values for inhibition of [3H]-PrBCM binding by a given ligand were generally higher in intact strips than those reported for broken-cell preparations. This effect is probably due, at least in part, to the presence of an access-limitation factor in the kinetics of the irreversible binding of [3H]-PrBCM to the intact tissue. 3 The mean Hill coefficients for antagonist binding approached unity, but those for strong agonists were significantly less than unity. There was, with the possible exceptions of hexyltrimethylammonium and oxotremorine, reasonably good agreement with the Hill coefficients reported for brain homogenates.

Animals↗