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Biomedical subjects

D C Evans

Publications and source records attributed to D C Evans.

At least 37 records · Page 2Linked to original sources
PubMed1993

Long-term results of staple capsulorrhaphy for anterior instability of the shoulder.

The results of 204 open staple capsulorrhaphies, performed consecutively as treatment for recurrent anterior instability of the shoulder in 192 patients, were reviewed after an average of ten years (range, two to twenty years). The operation had been performed for recurrent dislocations in 88 per cent of the shoulders and for recurrent subluxations in the remaining 12 per cent. Postoperative instability--dislocation or subluxation--occurred in 22 per cent of the shoulders and increased in frequency logarithmically with the duration of follow-up. In more than half of these shoulders, the episodes of postoperative instability were recurrent. In one-third of the shoulders, the stapling had been combined with a Putti-Platt procedure; in the others, a muscle-splitting approach had been used. The rate of recurrent instability was 8 per cent in the shoulders in which a Putti-Platt procedure had been added and 29 per cent in the shoulders that had been treated by stapling alone. The difference was significant (p = 0.002). Loosening or migration of a staple, or penetration of the articular cartilage by a staple, occurred in twenty-four shoulders (12 per cent); the staple was removed from eighteen of them. There was no significant difference in the rate of loosening or migration between non-barbed and barbed staples (p = 0.92). Pain, physical restrictions, and osteoarthrosis were more frequent in patients who had complications associated with a staple. Although most of the patients (84 per cent of the shoulders) thought that they had benefited from the operation, approximately half (51 per cent of the shoulders) had pain and approximately half (50 per cent of the shoulders) said that the shoulder was sufficiently different from normal to affect the quality of life. Problems with the shoulder that had not been present before the operation caused several patients (5 per cent of the shoulders) to change occupations. The average ranges of internal and external rotation were slightly reduced. The subjective and objective results after the stapling procedure were not as good as previous reports have suggested, and we no longer recommend staple capsulorrhaphy for anterior instability of the shoulder, even when it is augmented by a Putti-Platt procedure.

Adolescent↗
PubMed1991

Effect of chlorate on the sulfation of lipoprotein lipase and heparan sulfate proteoglycans. Sulfation of heparan sulfate proteoglycans affects lipoprotein lipase degradation.

In avian-cultured adipocytes 76% of the newly synthesized lipoprotein lipase is degraded before release into the medium (Cupp, M., Bensadoun, A., and Melford, K. (1987) J. Biol. Chem. 262, 6383-6388). The same group (Cisar, L. A., Hoogewerf, A. J., Cupp, M., Rapport, C. A., and Bensadoun, A. (1989) J. Biol. Chem. 264, 1767-1774) has proposed that the interaction of lipoprotein lipase with a class of cell surface heparan sulfate proteoglycans is necessary for degradation to occur. To test further this hypothesis, the binding capacity of the plasma membrane for the lipase was decreased by inhibiting the sulfation of glycosaminoglycans with sodium chlorate, an inhibitor of sulfate adenyltransferase. Chlorate decreased sulfate incorporation into trypsin-releasable heparan sulfate proteoglycans to 20% of control levels. The amount of uronic acid in the trypsin-releasable heparan sulfate proteoglycans remained constant. Therefore, chlorate decreased sulfation density on heparan sulfate chains by approximately 5-fold. In the same fractions, chlorate increased the median heparan sulfate Mr measured on Sephacryl S-300. Chlorate decreased the maximum binding of 125I-lipoprotein lipase to adipocytes by 4-fold, but no significant effects on the affinity constants were observed. Chlorate increased lipoprotein lipase secretion in a dose-dependent relationship up to 30 mM. Utilizing a pulse-chase protocol, it was shown that lipase synthesis in control and chlorate-treated cells was not significantly different and that the increased secretion could be accounted for by a decreased lipoprotein lipase degradation rate. In control cells 77 +/- 11% of the synthesized enzyme was degraded whereas in chlorate-treated cells degradation was reduced to 42 +/- 9% of the synthesized amount. The present study shows that decreased sulfation of heparan sulfate proteoglycans decreases the maximum binding of the lipase for the adipocyte cell surface. Consistent with the model that binding of lipoprotein lipase to cell surface heparan sulfate is required for lipase degradation, degradation is reduced in chlorate-treated cultures. In this report it is also shown that chlorate inhibits lipoprotein lipase sulfation and that desulfation of the enzyme has no effect on its catalytic efficiency or on its binding to cultured adipocytes.

Adipose Tissue↗
PubMed1991

Open reduction and internal fixation of radial head fractures.

Open reduction and internal fixation of displaced fractures of the radial head were reviewed in 14 elbows. Follow-up averaged 32 months. The average elbow score for Mason type II fractures was 96.8 points, corresponding to 100% good or excellent results. Average flexion was 142.5 degrees, and the mean fixed flexion deformity was 3.9 degrees. There was no loss in grip strength. An almost normal elbow was the expected result. Good or excellent results were achieved in only 33% of Mason type III fractures treated with open reduction and internal fixation. The average elbow score was 72.9 points, and this was statistically significantly different than the Mason type II fractures (p less than 0.05). An associated elbow dislocation did not affect the results significantly, but was associated with a slightly increased fixed flexion deformity. Fractures may be more comminuted than suggested by plain radiographs, and intraoperative decision making is required in deciding between reconstruction or excision of the radial head. Excellent results were obtained provided an anatomical reduction with stable fixation and early range of motion were achieved. If a stable anatomic reduction cannot be obtained, then alternative treatment methods should be considered.

Adult↗
PubMed1991

Contralateral shoulder instability following anterior repair. An epidemiological investigation.

We reviewed 188 patients at one to 20 years (mean 9.5) after surgery for anterior shoulder instability. Twenty-one had shown bilateral instability at the time of surgery, and 26 of the remaining 167 subsequently developed instability of the contralateral shoulder, giving an overall incidence of 24% bilateral involvement. Fourteen of these patients ultimately required bilateral surgery. The onset of contralateral instability was at one month to 15 years (mean 5.7 years) after anterior repair of the operated shoulder, the cumulative incidence increasing with time (p less than 0.01). The incidence was significantly higher in those under 15 years at the time of initial dislocation or under 18 at the time of surgery. One-half of the patients with contralateral instability had signs of posterior instability at follow-up. Other predisposing factors included having sustained the initial injury to the operated shoulder as a result of minimal trauma, and persistence of a sensation of instability in the operated shoulder. Factors which were not statistically significant included sex, dominant side, athletic activity, work history, and whether the initial surgery was for recurrent subluxations or dislocations. The high prevalence of bilateral shoulder instability suggests an intrinsic abnormality such as capsular and ligamentous laxity or muscle imbalance and warrants further investigations.

Adolescent↗
PubMed1991

The natural history of suspected scaphoid fractures.

Clinically suspected scaphoid fractures are common injuries. The authors prospectively followed up, by serial radiography and bone scanning, 23 patients who had a history of trauma to the carpus and associated localized tenderness to the anatomic "snuff box": in 15 patients the radiographs and bone scans were negative; in 5 the radiograph was equivocal and the bone scan positive. The authors concluded that patients with clinically suspected scaphoid fractures and negative radiographs can be treated symptomatically without immobilization in a cast. Patients with equivocal radiographs should be assumed to have a fractured scaphoid and treated accordingly.

Adolescent↗
PubMed1988

Inhibition of rat renal C-S lyase: assessment using kidney slice methodology.

Renal C-S lyase enzymes are implicated in the biotransformation of xenobiotics into potentially toxic metabolites by a deviation from the normal pathways of glutathione conjugate processing. C-S lyase enzymes occur in gastro-intestinal bacteria, and in liver as well as in mammalian and avian kidney. The renal enzyme cleaves the carbon-sulphur bond in cysteine conjugates derived from halogenated olefins (e.g. tetrafluoroethene, trichloroethene, and hexachlorobutadiene). Substituted S-nitrophenyl conjugates, which are analogues of a substrate for the hepatic C-S lyase enzyme (S-2,4-dinitrophenyl-L-cysteine), are demonstrated to display significant inhibition of rat renal C-S lyase using kidney slice methodology. They are also shown to disrupt the tubular uptake of organic cations and anions.

Ammonia↗
PubMed1987

Delayed union and nonunion of the tibia: experience in a community teaching hospital.

Delayed union and nonunion are frequent sequelae of high-energy tibial fractures, particularly compound ones. The authors studied 45 such cases; of these, 20 fractures were compound. The authors analysed the initial management but found no apparent correlation between the initial management of these fractures and subsequent delayed union or nonunion. The Phemister bone-grafting technique was used to achieve union and was considered a safe, efficacious method. Aggressive initial management of the soft-tissue component of tibial fractures is recommended to minimize the possible development of chronic osteomyelitis, a serious complication that occurred in eight patients and necessitated below-knee amputation in three.

Adolescent↗
PubMed1986

Influence of acute intracerebroventricular (i.c.v.) administration of adrenocorticotrophin (ACTH) on LH secretion in male rats: effect of pretreatment (i.c.v.) with ACTH antiserum on the serum LH response to an acute ether stress.

Adult male rats with chronic indwelling intracerebroventricular (i.c.v.) and jugular catheters were given an i.c.v. injection (over 1 min) of 1, 10, 100 ng or 1 microgram ACTH(1-24), or 300 ng ACTH(4-10) or saline, and blood samples were taken 0, 5, 15, 30 and 60 min later. Increasing dosages of ACTH(1-24) caused a dose-related rise in serum LH levels. Peak levels of serum LH (ranging from 157 to 473% of pretreatment levels) were reached 5-15 min after treatment, and then serum LH values returned to pretreatment levels by 60 min. The serum LH response to 1 microgram ACTH(1-24) did not differ from the response to 100 ng ACTH(1-24). Administration (i.c.v.) of 300 ng ACTH(4-10) was also effective in increasing serum LH values. Repeated withdrawal of blood during the experiment increased serum corticosterone values in all groups (including saline-treated), but i.c.v. administration of ACTH(1-24) or ACTH(4-10) did not further increase serum corticosterone levels. Two additional groups of rats were injected i.p. with either saline or pentobarbital (30 mg/kg body weight) 1 h before i.c.v. administration of 10 ng ACTH(1-24) and blood samples were taken as in the other groups. The animals in these groups did not show a rise in serum LH concentrations in response to ACTH(1-24). In a third experiment, rats were pretreated (i.c.v.) with either ACTH antiserum (ACTH-Ab) or normal rabbit serum 15 min before a 2-min ether stress. The ether stress evoked a significant rise in serum LH concentrations within 15 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗
PubMed1986

Actions of nizatidine, a selective histamine H2-receptor antagonist, on gastric acid secretion in dogs, rats and frogs.

Nizatidine (LY139037), a selective histamine H2-receptor antagonist, is a potent inhibitor of gastric acid secretion. It was 17.8 times as active as cimetidine on histamine (10(-5) M)-induced secretion from the isolated gastric mucosa of the bullfrog. Nizatidine was 8.9 times as active as cimetidine on basal acid secretion of the chronic gastric fistula rats after s.c. administration. Against acid secretion from the vagally innervated gastric fistula and Heidenhain pouch of dogs stimulated with submaximal doses of histamine, methacholine and gastrin, nizatidine was, respectively, 6.5, 5 and 4.7 times as active as cimetidine by i.v. administration. Nizatidine was very well absorbed from the gut and was 5 to 10 times as active as cimetidine on gastric acid secretion of dogs induced by submaximal and maximal doses of histamine when given p.o. Equal molar doses of nizatidine showed equal peak effects when given i.v., s.c. or i.m. Pharmacological data indicate that nizatidine is safe and effective as an agent for the control of excessive gastric acid secretion.

Administration, Oral↗
PubMed1986

Actions of nizatidine on the rat uterus, dog stomach and experimentally induced gastric lesions.

Nizatidine is a potent and selective antagonist of histamine. The histamine-induced relaxation of the KCl-treated rat uterus was inhibited dose-dependently by nizatidine. The inhibition was characterized by displacement of the dose-response to histamine to the right, in parallel, without depression of the maximum. The affinity of nizatidine for the histamine H2-receptor of the rat uterus was about 10 times that of cimetidine. The steady-state dose-response acid outputs stimulated by histamine from the Heidenhain pouch and the gastric fistula were also shifted dose-dependently by nizatidine, in parallel, to the right. The inhibition was consistent with a surmountable antagonism of histamine. At high (10(-4) to 10(-3) M) concentrations, nizatidine increased the motility of the guinea pig stomach and duodenum in vitro; this effect was abolished noncompetitively by atropine (10(-8) M) and pyrilamine (10(-4) M). Both nizatidine and cimetidine administered s.c. showed "cytoprotective" action by reducing the gastric lesions induced by 1) aminoguinidine and pylorus ligation and 2) HCl plus aspirin in the rat. On a weight and molar basis, nizatidine was 4 and 5.25 times as effective as cimetidine, respectively. This cytoprotective action of nizatidine was found when acidity and total acid load in the stomach were not affected by the histamine H2-receptor antagonist.

Animals↗
PubMed1986

Angiomatous involvement of an extremity. A spectrum of syndromes.

Congenital diffuse hemangiomatous involvement of the entire left thigh and knee joint in a 12-year-old girl was complicated by a Kasabach-Merrit type of consumptive coagulopathy. Repeated pathologic fractures of the left femur resulted in a nonunion. She also had a progressively increasing leg-length discrepancy, a stiff contracted knee, and leg atrophy distal to the knee. She was misdiagnosed originally as a Klippel-Trenauney syndrome, the progress of which is usually self-limited progression and involution. Despite steroid treatment, femoral artery banding, and intramedullary fixation of her femur, the hemangioma caused progressive debilitation of her left lower limb. At age nine, nonunion progressed to marked osteolysis and was treated by a through-knee amputation. A review of the literature revealed much confusion about multiple syndromes associated with angiomatous involvement of the lower limb. Prognostically, the depth and extent of the lesion were the most significant characteristics. This is well illustrated in this long-term follow-up study showing diffuse deep involvement that led to eventual amputation. Furthermore, this patient presents a multitude of complications developing from large angiomas.

Amputation, Surgical↗
PubMed1985

Single-dose amoxycillin in the treatment of bacteriuria in pregnancy and the puerperium--a controlled clinical trial.

Ninety obstetric patients with significant bacteriuria were treated randomly with either a single dose of 3 g amoxycillin or with a conventional course of ampicillin over 7 days. Treatment groups were comparable in terms of age, gravidity and socioeconomic status, and the outcome of pregnancy in the two groups did not differ significantly. Cure rates, assessed at 1 week and 6 weeks after treatment, were not significantly different: 88% for single-dose treatment and 84% for conventional treatment. It is concluded that a single dose of 3 g amoxycillin is a safe, effective and acceptable treatment for bacteriuria in pregnancy and the puerperium.

Adolescent↗