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Biomedical subjects

A Gilbert

Publications and source records attributed to A Gilbert.

At least 37 records · Page 2Linked to original sources
PubMed1995

Obstetrical palsy: early treatment and secondary procedures.

Obstetrical palsy has been described since a long time. Unfortunately, until the last 20 years, few options were available to correct its sequelae. During the last two decades, there has been a regain of interest because of the possibility to microsurgically repair these lesions. Tassin in 1984 demonstrated that babies who have no recovery of the biceps function by three months of age should be operated without delay. At brachial plexus exploration, in the presence of neuroma, nerve grafting is usually necessary. In cases of root avulsion, internal or external neurotization should be performed depending on the severity of the lesions. Physiotherapy and long-term follow-up of these patients are primordial to prevent joint ankylosis and to identify the patients who will benefit from secondary surgery. Our results are presented either after early treatment or after secondary procedures. These results justify aggressive management of obstetrical brachial plexus palsy because of children's great capacity for regeneration and accommodation.

Ankylosis↗
PubMed1994

Experimental and clinical study of the effect of naftidrofuryl on the recovery from peripheral nerve lesions.

After primary repair of lesions of nerves and vessels, patients who were administered a vasoactive drug, naftidrofuryl, postoperatively, had a better functional recovery than untreated patients. Evidence for the favourable effect of the drug on nerve regeneration was first obtained from experiments in the rat. The sciatic nerve was transected and repaired with standard microsurgical techniques. Results were evaluated by electromyography and histology. Data indicated that treated animals had better motor responses and distal latency than untreated rats. Fibre counts showed a greater number of nerve fibres in the distal stump of treated animals. The clinical study was undertaken in cases of carpal tunnel syndrome with muscle atrophy. Assessment was performed by electrophysiology: motor and sensory conduction was studied. Data showed that all treated patients recovered totally or partially from the thenar atrophy they presented before operation, whereas thenar atrophy persisted in 37% of the patients receiving placebo. In conclusion, naftidrofuryl has an experimentally and clinically favourable effect on nerve regeneration and on muscle trophicity, but the mechanism of action of this drug is not known.

Aged↗
PubMed1994

Upper tibial corticocancellous flap anatomy study (19.2.93).

A cortico-cancellous flap from the anterolateral aspect of the upper third of the tibia was presented. Sixty lower limbs of "fresh" cadavers were dissected. The vascular bundle includes the anterior tibial artery and its recurrent collateral branches and recurrent and musculoperiosteal arteries. The flap is harvested with the interosseous membrane and can be used either free or predicled. We used this flap for two patients suffering from pseudarthrosis. Long range clinical and radiological results are good.

Adult↗
PubMed1994

Renal transplantation into the dysfunctional bladder: the role of adjunctive bladder reconstruction.

A retrospective review of pediatric renal transplantation at 3 centers identified 9 patients who had undergone major bladder reconstruction. Seven patients underwent bladder augmentation (5 gastric, 1 colonic, 1 ureteral) and 2 received gastric neobladders. Six patients required Mitrofanoff neourethras. Patient survival was 100% with initial graft survival of 56% during a mean followup of 29.4 months. Eight patients (89%) are presently dialysis-free with functioning allografts and all 9 (100%) are continent of urine. We conclude that renal transplantation and reconstruction to ensure continence are justifiable in even the most anatomically compromised children with end stage renal disease. It is essential that the pediatric urologist should have an integral role in the management of such cases.

Adult↗
PubMed1994

Vaginal reconstruction: critical technical principles.

Childhood vaginal anomalies are frequently encountered, often in association with significant anorectal or urinary tract abnormalities. As a result, reconstruction poses a number of technical challenges. We maintain that the best results are achieved by single stage perineal reconstruction. The primary goal of achieving a functional and cosmetically adequate vagina must not be at the expense of the optimal repair of associated urinary and anorectal abnormalities. In addition, since these repairs are performed early in childhood, vaginal growth is an issue that further limits the choice of reconstructive technique. We present a series of successful vaginal reconstructions in complex cases and an outline of the principles of surgical care.

Abnormalities, Multiple↗
PubMed1994

Surgical implications of genitourinary tract anomalies in patients with imperforate anus.

Genitourinary anomalies in patients with imperforate anus are a frequent source of significant morbidity. We report a retrospective study of 64 genitourinary procedures performed on 23 patients. Renal, collecting system, bladder and perineal anomalies were encountered in 65%, 83%, 87% and 65% of these complex cases, respectively. A total of 70% of the patients required intermittent catheterization due to bladder dysfunction. Surgical alternatives, complications of management and functional outcomes are reviewed in detail. Genitourinary reconstruction is best undertaken as an integral part of imperforate anus reconstruction. Failure to do so results in the loss of surgical alternatives, unnecessary reoperative procedures and compromised outcomes.

Abnormalities, Multiple↗
PubMed1993

Congenital pseudarthrosis of the forearm: treatment of six cases with vascularized fibular graft and a review of the literature.

Six cases of pseudarthrosis of the forearm are reported. One involved only the radius, one the ulna alone, and four both forearm bones. There was associated neurofibromatosis in five cases. All the cases were treated by wide resection and free vascularized fibular graft. In two cases, a single-bone forearm was created. In all cases, good results were achieved, with moderate forearm shortening. The literature suggests electrical stimulation, corticoperiosteal graft, osteotomy of the involved bone, and free vascularized bone grafting as treatment alternatives. Vascularized free bone grafting appears to be more successful than other treatments. The use of microsurgical sutures permits this treatment in young patients.

Adolescent↗
PubMed1993

Two steps of insulin receptor internalization depend on different domains of the beta-subunit.

The internalization of signaling receptors such as the insulin receptor is a complex, multi-step process. The aim of the present work was to determine the various steps in internalization of the insulin receptor and to establish which receptor domains are implicated in each of these by the use of receptors possessing in vitro mutations. We find that kinase activation and autophosphorylation of all three regulatory tyrosines 1146, 1150, and 1151, but not tyrosines 1316 and 1322 in the COOH-terminal domain, are required for the ligand-specific stage of the internalization process; i.e., the surface redistribution of the receptor from microvilli where initial binding occurs to the nonvillous domain of the cell. Early intracellular steps in insulin signal transduction involving the activation of phosphatidylinositol 3'-kinase are not required for this redistribution. The second step of internalization consists in the anchoring of the receptors in clathrin-coated pits. In contrast to the first ligand specific step, this step is common to many receptors including those for transport proteins and occurs in the absence of kinase activation and receptor autophosphorylation, but requires a juxta-membrane cytoplasmic segment of the beta-subunit of the receptor including a NPXY sequence. Thus, there are two independent mechanisms controlling insulin receptor internalization which depend on different domains of the beta-subunit.

Amino Acid Sequence↗
PubMed1993

Trial of an intervention to reduce chronic benzodiazepine use among residents of aged-care accommodation.

BACKGROUND: Many residents of aged-care accommodation are chronic users of benzodiazepines. This pattern of use contradicts current guidelines and may adversely affect residents. It was hypothesised that a lasting reduction in benzodiazepine use could be achieved through a programme which involved prescribers, residents and caregivers in the change process. AIM: To demonstrate that an intervention which involved education and relaxation training for patients, and education of prescribers and caregivers, could reduce levels of chronic benzodiazepine use among residents of an aged-care facility. METHODS: Two aged-care facilities from metropolitan Adelaide were chosen; one received the intervention, the other was a no-intervention comparison. Pre-test, post-test and follow-up interviews were conducted with 60 residents: 27 from the intervention setting and 33 from the comparison setting. Residents at the intervention setting were provided with relaxation skills training, and their medical practitioners and caregivers were provided with information about alternative strategies for managing sleep disturbance. Outcome measures were: the proportion of residents using benzodiazepines, total medication use, cognitive performance, emotional responsiveness, subjective health and sleep ratings and an index of well-being. RESULTS: The proportion of participants in the intervention condition who used benzodiazepines declined significantly (from 70% to 35%); the reduction was maintained over the subsequent three months. No adverse consequences were associated with cessation of benzodiazepine use; there was improvement in emotional responsiveness among those who ceased benzodiazepine use. This structured intervention strategy is a useful approach for reducing levels of chronic benzodiazepine use among residents of aged-care accommodation.

Affect↗
PubMed1993

Medication use and its correlates among the elderly.

Medication use and its correlates were examined in a randomly selected sample of 178 urban-dwelling elderly people: 89 per cent were currently using medication and 44 per cent were using four or more medications concurrently. Forty percent were using at least one nonprescription medication, usually in combination with prescription medication. The treatment of hypertension was the most commonly given reason for medication use. Respondents demonstrated good knowledge of their medication and how to take it, and good compliance with prescribing instructions. Multiple medication use was associated with advanced age, living in supervised accommodation, and a range of measures indicative of reduced wellbeing. There was no association between cognitive functioning and multiple medication use. These findings suggest that stereotypical images of older people as being poor compliers and having little knowledge about their medication should be treated with caution. However, the extensive use of medication and of multiple medications and concerns about the appropriateness of use of some classes of medication highlight the need for more detailed study of medication use among the elderly.

Aged↗
PubMed1993

Assay of brain natriuretic peptide (BNP) in human plasma: evidence for high molecular weight BNP as a major plasma component in heart failure.

A RIA for human brain natriuretic peptide (BNP) was developed. Both BNP and atrial natriuretic peptide (ANP) were extracted from human plasma with Vycor glass powder (71% recovery for BNP). The assay had a minimum detection limit of 0.45 fmol/tube and an IC50 of 9 fmol/tube. The within-assay coefficients of variation were 11.4% at 4 pmol/L and 3.2% at 22 pmol/L, and the between-assay coefficient of variation was 11% at 24 pmol/L. There was no significant loss of immunoreactive (IR)-BNP in plasma samples stored at -80 C for 4 weeks. Low rates of labeled BNP and IR-BNP degradation occurred in EDTA plasma incubated at 37 C. The mean venous plasma IR-BNP (6.3 +/- 0.3 pmol/L) in normal subjects (n = 48) was significantly lower than plasma ANP (8.4 +/- 0.6 pmol/L). In contrast to ANP, IR-BNP did not increase when normotensive or hypertensive subjects changed from erect to supine posture. Markedly elevated levels were found in patients with congestive heart failure (mean IR-BNP, 87 +/- 11 pmol/L; ANP, 87 +/- 12 pmol/L; n = 35), recent myocardial infarction (mean IR-BNP, 60 +/- 9 pmol/L; ANP, 33 +/- 6 pmol/L; n = 7), and chronic renal failure. High pressure liquid chromatography of plasma extracts from heart failure subjects revealed both high (mol wt, 10,000) and low (mol wt, 4,000) mol wt IR-BNP. High mol wt BNP was the major component (mean ratio, 1.9:1) and was linearly correlated with low mol wt BNP (r = 0.99). HPLC of plasma extracts from three normal subjects receiving constant infusions of human BNP (2 pmol/kg.min) showed a single major peak eluting in the position of hBNP-32, with no evidence of high mol wt material. These results show that whereas marked elevations in BNP occur in circulatory disorders, a major (> 50%) and consistent contribution to immunoreactivity is due to precursor forms. Further, compared to ANP, there is no IR-BNP response to supine posture in normal and hypertensive subjects.

Adult↗
PubMed1993

Endocytosis is inhibited in hepatocytes from diabetic rats.

The consequences of type I diabetes on cellular endocytosis were investigated by comparing [125I]insulin, [125I]alpha 2-macroglobulin, and Lucifer yellow uptake in hepatocytes freshly isolated from control and STZ-induced diabetic rats. In addition to the previously described reversible inhibition of ligand-induced internalization of the insulin receptor, we report a decrease in the constitutive receptor-mediated endocytosis of alpha 2-macroglobulin and a near abolition of fluid-phase endocytosis of Lucifer yellow in cells from diabetic animals. Despite decreased receptor autophosphorylation and internalization, the ligand-induced surface redistribution of the insulin receptor was normal in the diabetic cell population. By contrast, the insulin receptor association with clathrin-coated pits was impaired in diabetic cells as a result of a decreased concentration of these specialized invaginations on the nonvillous cell surface. The morphology and diameter of clathrin-coated pits were similar in both conditions under study. These results demonstrate a general impairment of endocytosis in hypoinsulinemic diabetes: receptor-mediated endocytosis was less affected than fluid-phase endocytosis. Impaired endocytosis of specific ligands or other macromolecules could be an important mechanism underlying the accumulation of extracellular matrix or even blood cholesterol removal in diabetes.

Animals↗
PubMed1993

[Free transfer of the vascularized fibula in pseudarthrosis and femoral bone loss].

The authors report their experience of femoral reconstruction by free fibular graft transfer. Twenty eight patients were operated on between 1977 and 1988. The average follow-up was 7 years and 3 months. The etiology of most of the cases was a post traumatic lesion (70 per cent). Loss of substance was found in 19 cases. 60 per cent of these were septic. The approach was usually posterior and vessels from the sciatic nerve were used. Union was obtained in 89 per cent of the cases. In 65 per cent of the cases union occurred in less than 1 year. In 1 out of 4 cases graft thickening was necessary and achieved by secondary bone grafts. The comparison of this technique with standard treatments evidenced a definite superiority of vascularized bone grafts in cases of septic pseudarthrosis and significant losses of bone.

Adolescent↗
PubMed1992

Results of the renewed extravesical reimplant for surgical correction of vesicoureteral reflux.

In 1987 Firlit et al described their results using Hodgson's technique of the modified extravesical Gregoir-Lich procedure. They coined the term detrusorrhaphy or extravesical ureteral advancement to describe this technique. During the last 4 years we performed this reimplantation on 211 ureters in 132 patients. Of the patients 79 had unilateral and 53 had bilateral procedures. Included were 6 megaureters requiring ureteral tailoring and 9 uncomplicated duplications. All but 1 patient were cured of reflux. No postoperative obstruction was encountered. Our results indicate that this is an excellent procedure to repair vesicoureteral reflux with minimal morbidity and short hospital stay.

Child↗
PubMed1992

Free bladder mucosal graft biology: unique engraftment characteristics in rabbits.

To study the biology of bladder mucosal grafts we developed an animal model using New Zealand white male rabbits. A 25 x 9 mm. segment of bladder mucosa was harvested and tubularized over an 8F catheter using 7-zero polyglactin sutures. An equivalent portion of rabbit urethra was then excised and the graft was anastomosed to this defect in an end-to-end fashion. A urethral catheter was left in place to provide bladder drainage and to stent the anastomosis. Animals were sacrificed on postoperative days 1 to 90. India ink was injected into the aorta at sacrifice to visualize the microvasculature. All 59 specimens were stained with hematoxylin and eosin, and studied using light microscopy. Our results demonstrated vascular ingrowth at 72 hours. Between postoperative days 8 and 10 healthy viable epithelium first bridged the entire urethral defect. By postoperative day 12 the epithelial lining was complete. A poor outcome was observed in all animals whose stents were removed early. We conclude that the biology of bladder mucosal grafts is unique in that the graft initially undergoes partial degeneration followed by regeneration. Of concern are the results of those animals whose stents were removed early. In all such cases a poor outcome was observed.

Animals↗
PubMed1992

A new flap based on the distal branches of the radial artery.

A flap based on the distal branches of the radial artery is raised on the dorso-lateral aspect of the distal third of the forearm. Thirty fresh cadaver dissections have established the anatomical rationale of the flap. The potential territory is supplied by a subaponeurotic plexus of vessels fed by lateral branches of the radial artery in the distal third of the forearm. This new knowledge of the anatomy has been applied to the performance of this flap in seven clinical cases. Various methods of application to hand and wrist reconstruction are described along with a discussion of the various advantages and disadvantages.

Adult↗
PubMed1992

The versatile metacarpal and reverse metacarpal artery flaps in hand surgery.

Vascular anatomy of dorsal metacarpal arteries was investigated in fresh cadaver dissections and by injection of methylene blue. Origin and termination of the vessels were studied, as well as their connection to the palmar vasculature. Vascular territories and elevation of flaps based on these vessels are also discussed. The second dorsal metacarpal artery was found to be the most consistent. This vessel has a large distal connection to the palmar vessels which allows both proximal and reverse elevation. Representative cases and surgical technique are described.

Adult↗