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Biomedical subjects

R L Wilson

Publications and source records attributed to R L Wilson.

At least 55 records · Page 3Linked to original sources
PubMed1985

Flexor tendon grafting.

The decision to reconstruct the flexor mechanism should be based upon a thorough understanding of the principles and techniques of tendon grafting and comprehension of the patient's functional needs. By itself, insertion of a tendon implant with later grafting will not guarantee a satisfactory result; this procedure is no substitute for an awareness of basic rules and axioms. Careful selection, meticulous technique, and an attentive rehabilitation program will provide patients with the best results.

Fingers↗
PubMed1984

Intraplaque hemorrhage: its significance in cerebrovascular disease.

Recently, carotid plaque factors, specifically intraplaque hemorrhage, have been studied with respect to the production of cerebrovascular symptoms. Ninety-five carotid endarterectomies were performed and the plaques that were removed were examined for intraplaque hemorrhage. Patients were separated into three groups: those with specific neurologic symptoms, those with nonlateralizing symptoms, and those who were asymptomatic. In the group of patients who presented with specific neurologic symptoms, correlation was made between the age of the intraplaque hemorrhage and the timing of symptoms. The vast majority of patients with specific neurologic symptoms exhibited carotid plaque hemorrhage, but patients with nonlateralizing symptoms and those who were asymptomatic also demonstrated an unexpectedly high percentage of intraplaque hemorrhage. Moreover, our results show a poor relationship between the timing of symptoms and the age of the intraplaque hemorrhage. These data do not refute the concept that intraplaque hemorrhage may play a role in the production of cerebrovascular symptoms, but they do refute the notion that the mere presence of hemorrhage causes specific neurologic symptoms and they also refute the previous report that demonstrates a good correlation between the timing of symptoms and the age of the intraplaque hemorrhage.

Aged↗
PubMed1984

In vitro comparison of the selectivity of electrodes for in vivo electrochemistry.

The properties of 4 types of carbon electrodes designed for use as in vivo sensors of easily oxidized species in the mammalian brain have been evaluated in aqueous solutions at physiological pH. The electrodes are formed from a graphite-epoxy mixture, carbon paste, or carbon fibers, and have the geometries of a disk or a cylinder. The voltammetric properties of several catecholamines, some of their metabolites and precursors, uric acid, and ascorbic acid are reported at unmodified carbon surfaces. The problem of overlap of the voltammetric waves of ascorbate and catechols is addressed, and two different methods which minimize this problem are examined. These are the use of disk-shaped electrodes fabricated from carbon fibers, which facilitate the use of subtracted voltammograms to determine small changes in the concentration of catecholamines in the presence of ascorbic acid, and the use of electrochemically modified, cylindrically-shaped electrodes also fabricated from carbon fibers. Voltammetry at the modified electrodes gives evidence the catechols can be resolved from ascorbate, and that catechols, but not ascorbic acid, adsorb to the electrode surface.

Animals↗
PubMed1984

The restricted simple Lie algebras are of classical or Cartan type.

The classification of the finite-dimensional restricted simple Lie algebras over an algebraically closed field F of prime characteristic p > 7 is announced. Such an algebra is either of classical type (an analogue over F of a finite-dimensional simple Lie algebra over the complex numbers) or of Cartan type (an analogue over F of one of the infinite Lie algebras of Cartan over the complex numbers).

Journal Article↗
PubMed1984

Production of superoxide during the metabolism of nitrazepam.

Nitrazepam is metabolized in both humans and rats to 7-amino-nitrazepam OFFicating that this drug is reduced to a number of metabolic intermediates including several free radical species. When rat-hepatic microsomes are incubated with NADPH in the presence of nitrazepam, its nitro anion free radical was observed under anaerobic conditions. In the presence of oxygen, this free radical reduced oxygen giving nitrazepam and superoxide. 7-Nitroxyl-nitrazepam was produced by the chemical oxidation of 7-amino-nitrazepam using m-chloroperbenzoic acid. Reaction of this reactive free radical with hepatic microsomes led to the covalent spin labelling of microsomal protein. This phenomenon was also observed by the enzymic oxidation of 7-amino-nitrazepam with hepatic microsomes, obtained from a phenobarbital-induced rat, in the presence of a NADPH-generating system. With the generation of superoxide and hydrogen peroxide (arising from the dismutation of superoxide), it is not surprising that nitrazepam-enhanced lipid peroxidation was demonstrated by monitoring the production of lipid peroxyl radicals using spin-trapping techniques.

Animals↗
PubMed1984

Plasma constituents and body weights of Japanese quail (Coturnix coturnix japonica) selected for twelve generations for plasma cholesterol responses to adrenocorticotropin.

Japanese quail were selected bidirectionally over 12 generations for plasma cholesterol (PC) responses to adrenocorticotropin (ACTH). In addition to the selected trait, plasma corticosteroids (PCS), triglycerides (PT), and glucose (PG) were measured before and after 3 daily injections of ACTH. The quail were also weighed at 31 days of age. By the 12th generation of selection, when measurements were expressed as deviations from the randombred control (C) line from which the selected lines had been derived, there was a difference in PC of approximately 55% between the high response (HR) and the low-response (LR) lines. Pre-ACTH PCS levels increased in all three lines over generations; however, relative to the C line, there was no difference between selected lines. The 3 days of ACTH injection depressed PCS levels. Relative to the C line, pre- and post-ACTH levels of PT were higher in the HR line than in the LR line, and the LR line declined linearly over generations. Levels of PG did not change over generation in the selected lines; however, pre-ACTH levels of PG tended to be higher in the LR line than in the HR line in all generations. Body weights of the HR line at 31 days remained almost exactly the same as the C line, but those of the LR line declined linearly over the 12 generations of selection. These studies demonstrated that the PC response to ACTH was moderately heritable (h2 approximately equal to .20).

Adrenal Cortex Hormones↗
PubMed1983

Rehabilitation after amputations in the hand.

It is important to recognize the psychological and cosmetic aspects of amputation. More data are needed regarding the functional loss at various amputation levels so that patients can be counseled more effectively. Rehabilitation and reconstructive surgery can then produce results that will be more meaningful to the patient in terms of employment and everyday use of the hand.

Amputation, Surgical↗
PubMed1982

Occult dental infection causing fever in renal transplant patients.

Fever secondary to odontogenic infection following successful renal transplantation is reported in three patients. All three patients initially lacked signs or symptoms localizing to the oral cavity, and two of the three patients did not have x-ray evidence of abscess formation. Two patients received antibiotic therapy without any apparent clinical response, and all three patients responded promptly to surgical extractions. Our patients illustrate that fever can be the only sign of dental sepsis in renal transplant recipients, and tooth extraction as empiric therapy may be necessary. Most important, however, is that the dental pathology responsible for their fever could have been detected and treated prior to transplantation. We recommend pretransplant dental evaluation of all patients with extraction of partially impacted molars and treatment of all periodontal disease and dental caries.

Adolescent↗
PubMed1982

Tc-99m pertechnetate uptake in a thymoma: case report.

A case is reported to Tc-99m pertechnetate accumulation within an anterior mediastinal thymoma during a search for substernal goiter. This reemphasizes the non-specificity of Tc-99m pertechnetate uptake and the need for caution in using this agent to detect ectopic thyroid tissue.

Diagnosis, Differential↗
PubMed1981

Autoimmune sensorineural deafness: case report.

Rapidly progressive binaural sensorineural deafness responding to steroid therapy has recently been recognised. Clinical and laboratory findings indicate an autoimmune aetiology. The scant literature is discussed, and a case report presented. The importance of this entity is stressed because of the beneficial effects of therapy.

Autoimmune Diseases↗
PubMed1981

A new family of algebras underlying the Rogers-Ramanujan identities and generalizations.

The classical Rogers-Ramanujan identities have been interpreted by Lepowsky-Milne and the present authors in terms of the representation theory of the Euclidean Kac-Moody Lie algebra A(1) ((1)). Also, the present authors have introduced certain "vertex" differential operators providing a construction of A(1) ((1)) on its basic module, and Kac, Kazhdan, and we have generalized this construction to a general class of Euclidean Lie algebras. Starting from this viewpoint, we now introduce certain new algebras [unk](v) which centralize the action of the principal Heisenberg subalgebra of an arbitrary Euclidean Lie algebra [unk] on a highest weight [unk]-module V. We state a general (tautological) Rogers-Ramanujan-type identity, which by our earlier theorem includes the classical identities, and we show that [unk](v) can be used to reformulate the general identity. For [unk] = A(1) ((1)), we develop the representation theory of [unk](v) in considerable detail, allowing us to prove our earlier conjecture that our general Rogers-Ramanujan-type identity includes certain identities of Gordon, Andrews, and Bressoud. In the process, we construct explicit bases of all of the standard and Verma modules of nonzero level for A(1) ((1)), with an explicit realization of A(1) ((1)) as operators in each case. The differential operator constructions mentioned above correspond to the trivial case [unk](v) = (1) of the present theory.

Journal Article↗
PubMed1981

The Rogers-Ramanujan identities: Lie theoretic interpretation and proof.

The two Rogers-Ramanujan identities, which equate certain infinite products with infinite sums, are among the most intriguing of the classical formal power series identitites. It has been found by Lepowsky and Milne that the product side of each of them differs by a certain factor from the principally specialized character of a certain standard module for the Euclidean Kac-Moody Lie algebra A(1) ((1)). On the other hand, the present authors have introduced an infinite-dimensional Heisenberg subalgebra [unk] of A(1) ((1)) which leads to a construction of A(1) ((1)) in terms of differential operators given by the homogeneous components of an "exponential generating function." In the present announcement, we use [unk] to formulate a natural "abstract Rogers-Ramanujan identity" for an arbitrary standard A(1) ((1))-module which turns out to coincide with the classical identities in the cases of the two corresponding standard modules. The abstract identity equates two expressions, one a product and the other a sum, for the principally specialized character of the space Omega of highest weight vectors or "vacuum states" for [unk] in the module. The construction of A(1) ((1)) leads to a concrete realization of Omega as the span of certain spaces of symmetric polynomials occurring as the homogeneous components of exponential generating functions. The summands in the Rogers-Ramanujan identities turn out to "count" the dimensions of these spaces. For general standard A(1) ((1))-modules, we conjecture that the abstract identities agree with generalizations of the Rogers-Ramanujan identities due to Gordon, Andrews, and Bressoud.

Journal Article↗
PubMed1981

Humoral immunity in renal transplantation Detection of cytotoxic antibodies to lymphocyte antigens other than HLA-A,B,C and Ia-like antigens in patients with vascular graft rejection.

By using a Fab2 fragment blocking assay with cultured human B lymphoid cells and peripheral lymphocytes as targets, cytotoxic antibodies to Ia-like antigens, to HLA-A,B,C antigens, and to lymphocyte structures other than these two types of histocompatibility antigens were identified in serial post-transplant sera from 18 renal allograft recipients. Multiple combinations of these three types of antibodies were seen in 78% of the sera. A higher reactivity as well as higher titers of antibodies were found in patients with graft failure from rejection. The occurrence of anti HLA-A,B,C or anti Ia-like antibodies did not show any relationship to graft outcome. However, cytotoxic antibodies to other antigens (referred to as non-HLA antibodies) were detected in five of the six patients with graft failure and in only one patient with graft survival. In this latter patient, non-HLA antibodies occurred with a chronic rejection episode and were no longer detectable when the rejection ceased. This study shows that the Fab2 fragment blocking assay is a useful method to identify antibodies to multiple specificities in sera from kidney graft recipients, and suggests that non-HLA cytotoxic antibodies may be associated with graft rejection.

Antibody Formation↗