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Biomedical subjects

G A Hunter

Publications and source records attributed to G A Hunter.

At least 37 records · Page 2Linked to original sources
PubMed1987

The value of revision surgery after initial amputation of an upper or lower limb.

The value of revision surgery when carried out more than six weeks after initial amputation of the upper or lower limb was assessed. When performed for stump and/or phantom limb pain alone, only 33/95 (35%) obtained satisfactory results after one revision; 25/95 (26%) of the patients required four or more surgical procedures without relief of pain. However, when carried out for local specific pathology, the results of surgical revision were 100% successful, even if the procedure had to be repeated once in 15% (28/189) of this group of patients. Transcutaneous nerve stimulation appeared to offer no long lasting relief of pain following amputation surgery.

Adult↗
PubMed1987

Bilateral lower extremity amputations after prolonged application of the pneumatic antishock garment: case report.

The authors describe the case of a 29-year-old man with multiple trauma who suffered compartment syndromes necessitating bilateral lower limb amputations as a result of the prolonged (9.5 hours) application of a pneumatic antishock garment (PASG). There was no evidence of lower limb trauma before the garment was put on. Despite the apparent benefits of the PASG in traumatized hypovolemic patients, the lowest possible inflation pressures should be used and removal attempted as soon as hemodynamic stability can be assured.

Adult↗
PubMed1987

Endogenous adenosine-receptive systems do not mediate the discriminative stimulus properties of ethanol.

Adenosine is an endogenous neuromodulator with depressant effects on CNS neurons. Adenosine agonists produce biphasic effects on activity, decreases in operant response rate, and anticonvulsant effects. These effects are similar to some of the behavioral effects of ethanol. In addition, it has recently been shown that relative sensitivities to some of the behavioral effects of ethanol and purinergic drugs are similar in inbred strains of mice. These findings have prompted the speculation that ethanol's behavioral effects may be mediated by an agonist action on adenosine-receptive neurons. The present study provided a direct test of this hypothesis with respect to the discriminative stimulus properties of ethanol. In this study, neither the A1 receptor agonist N6-cyclohexyladenosine nor the A2 receptor agonist N6-ethylcarboxamide adenosine produced significant generalization to the ethanol stimulus. In addition, neither the adenosine deaminase inhibitor erythro-9-(2-hydroxy-3-nonyl)-adenine nor the adenosine uptake inhibitor dipyridamole were able to enhance the level of ethanol-appropriate responding seen after a low dose of ethanol. Both caffeine and 8-phenyltheophylline partially but significantly antagonized the stimulus properties of ethanol. However, the doses required to achieve these effects were much higher than those needed to block adenosine receptors. These findings strongly suggest that the discriminative stimulus properties of ethanol are not mediated through an agonist action on adenosine-receptive neurons.

Animals↗
PubMed1986

Naloxone's effects on intake of sequentially presented fluids.

Fluid-deprived rats were presented with one of three types of palatable solutions for 15 min, followed by access to either the same solution or one of the other types for 15 min. The solutions were 5.3% sucrose, 0.9% salt solution, and tap water. Naloxone reduced intake of all solutions, as compared to placebo, regardless of type of fluid or order of presentation. Rats receiving water followed by sucrose solution reduced their intake of water under naloxone, but did subsequently take a considerable amount of sucrose solution showing that they were capable of drinking more. These findings indicate that naloxone's effects closely track ordinary satiation-effects, merely enhancing satiation-like functions at each instance of opportunity to take fluids.

Animals↗
PubMed1986

Prosthetic use in adult upper limb amputees: a comparison of the body powered and electrically powered prostheses.

Three hundred and fourteen adult upper limb amputees were reviewed retrospectively at the Ontario Workers' Compensation Board. A questionnaire was used to evaluate the use of body and electrically powered prostheses. Follow-up ranged from 1 to 49 years with a mean of 15 years. Results indicated that complete or useful acceptance of an electrically powered prosthesis was reported by 69 of 83 amputees (83%); 199 of 291 amputees (68%) used the cable operated hook, 57 of 291 (20%) used the cable operated hand and 40 of 83 (48%) used the cosmetic prosthesis. The majority of amputees used more than one prosthesis for their functional needs and should be fitted with more than one type of prosthesis. Acceptance of an upper limb prosthesis by 89% (196/220) of below-elbow, 76% (56/74) of above-elbow and 60% (12/20) of high level amputees indicates that for most upper limb amputees, their prostheses are well used and essential to their personal and employment activities.

Activities of Daily Living↗
PubMed1985

Toward understanding ethanol's capacity to be reinforcing: a conditioned place preference following injections of ethanol.

Rats that had previously consumed a 6% ethanol (ETOH) solution daily for 26 days and rats without such a history served as subjects in a test for the ability of ETOH to establish a conditioned place preference. The time of putative conditioning was from 4 to 8 min after injections of ETOH, 1 g/kg. The combination of programming the period of putative conditioning to be shortly after injections and using rats habituated to drinking ETOH allowed a conditioned place preference to emerge after only a few conditioning trials. Such a result potentially reveals features of the way ETOH achieves its reinforcing capability and sets the stage for understanding the mechanism of that reinforcement.

Animals↗
PubMed1985

Selected opioids and responding for intracranial reinforcement.

Rats fixed with chronically indwelling electrodes for intracranial stimulation (ICS) of the lateral hypothalamus pressed a lever during daily sessions for a fixed intensity of ICS. Before some sessions, they were given placebo, or ethylketocyclazocine (EKC) in racemic or isomeric forms [either (+)EKC or (-)EKC]. Naloxone (NX) was also given with the agents. The racemate facilitated pressing across a narrow range of small doses (centered about 0.02 mg/kg). At no dose did (-)EKC, a potent analgesic, facilitate pressing and typically depressed it. (+)EKC, at doses of 0.04 and 0.08 mg/kg, facilited pressing. These data provide further confirmation that opioid analgesia and ability to enhance pressing are separable. When NX was given with a large dose of the racemate, paradoxically pressing for ICS was facilitated. Apparently, NX selectively blocked the effects of (-)EKC. SKF 10047 was also administered in racemic and isomeric forms. All three forms produced some facilitation of pressing at small doses (e.g., 0.75 mg/kg) and depressed pressing at large doses (e.g., 5.0 mg/kg).

Animals↗
PubMed1985

Electrically powered prostheses for the adult with an upper limb amputation.

The value of fitting adult upper limb amputees with electrically powered prostheses is assessed. In a series of 164 amputees, complete or useful acceptance of an electrically powered prosthesis was recorded in 80% of below-elbow amputees, 69% of above-elbow amputees and 72% of high level amputees. Patients expressed satisfaction with the combination of comfort, cosmesis and function. Results indicate that, accepting the high cost, an electrically powered prosthesis can provide important function to the upper limb amputee.

Adolescent↗
PubMed1985

A review of employment patterns of industrial amputees--factors influencing rehabilitation.

More than 1,000 industrial amputees at the Ontario Workers' Compensation Board were reviewed. The study investigated the current employment status of amputees and the factors that influenced successful return to work post-amputation. The data obtained from a mailed questionnaire was analysed by the Statistical Analysis System. The results revealed that 89% of amputees returned to work after an amputation. The average follow-up post-amputation was 14 years with a range of one to 64 years. At the time of review the current employment status of amputees was as follows: 51% full time employed, 5% part-time employed, 25% retired and 8% unemployed. The remainder were engaged in a vocational activity, still recovering or were not seeking work. The data revealed that amputees typically changed jobs when returning to the work force. Amputees returned to jobs that were less physically demanding, but required greater intellectual skills in occupations such as clerical and service industries. Factors including prosthetic use, vocational services, and a younger age at the time of amputation were identified as being positively associated with a return to work. Those factors that were negatively related to successful employment included stump and phantom limb pain and multiple limb amputations. The study concluded that the majority of the amputees reviewed were successful in returning to work. The authors suggest that amputees benefit from treatment programmes that include medical, prosthetic and vocational services.

Accidents, Occupational↗
PubMed1985

Limb amputation and re-amputation in association with chronic pain syndrome.

A small group of patients is reported in whom amputation or re-amputation of the upper or lower limb has been performed at increasingly higher levels in an unsuccessful attempt to relieve the patients' unrecognized chronic pain syndrome. The possibility of self mutilation should also be considered. The etiological factors and management of this uncommon but difficult problem are discussed. It is hoped that members of an experienced amputee team will recognize this rare problem and help to avoid multiple surgical procedures, which are harmful to the patient and costly to society.

Adult↗
PubMed1985

Syme's amputation in adults: a long-term review.

A retrospective study was undertaken in two patient populations to establish the failure rate of Syme's amputation. Failure was defined as an amputation requiring revision to a more proximal level. For traumatic lesions of the foot the failure rate was 29% and for dysvascular lesions it was 41%. The long-term functional results in 55 patients who underwent Syme's amputation for traumatic, dysvascular or congenital lesions were studied. Overall, 73% had good function. The ideal Syme's stump, where the fat pad is centred securely over the distal tibia, was noted in only 22% of patients. The authors conclude that, in the past, technical details may have been overemphasized, because in this study the functional results of Syme's amputation were more dependent on prosthetic fitting. This type of amputation is not recommended for patients with dysvascular lesions because of the high failure rate.

Adult↗
PubMed1985

Review of the operative treatment of Achilles tendon rupture.

Sixty-eight patients' charts were reviewed for ascertainment of the complication rate following operative repair of ruptured Achilles tendons. Ninety-two percent of 48 patients whose cases underwent clinical evaluation returned to their preinjury activity status: 13% had incisional complications, most of which resolved. The rerupture rate was 3% (2/68). The results of this series and a literature review show that operative treatment can be regarded as an acceptable method. Nonoperative treatment should be considered in a nonathletic patient over the age of 50 years because of potentially serious problems with wound healing.

Achilles Tendon↗
PubMed1984

A six-year follow-up of infected total hip replacements managed by Girdlestone's arthroplasty.

Thirty-three Girdlestone's arthroplasties used to salvage infected total hip replacements were followed for a mean of 6.2 years to assess the efficacy of this procedure. Subjective and objective assessment was obtained at the time of review. Gram-negative organisms, retained cement, bony sequestra and secondary healing were common features of the five patients (15%) whose wounds discharged for more than four weeks after operation. Girdlestone's arthroplasty provided satisfactory pain relief in 91% of patients, and control of infection in 97%. Although leg-length discrepancy (mean 4 cm) and a Trendelenburg gait made walking difficult and tiring , 42% were satisfied with their functional ability; 85% needed walking aids, and 3 patients could not walk at all and were confined to bed or a chair. Overall, 79% were satisfied. Objectively, the mean Harris hip rating was 60; however, if patients with multiple joint problems were excluded, this score increased to 77. Girdlestone's arthroplasty seems a reasonable salvage procedure in the management of an infected total hip replacement and the results seem to improve with time.

Adult↗
PubMed1983

Effects of LH-RH and des-Gly10[D-Ala6]LH-RH-ethylamide on plasma gonadotropin levels and oocyte maturation in adult female coho salmon (Oncorhynchus kisutch).

Plasma gonadotropin (GtH) levels and state of oocyte development were determined in adult female coho salmon following single intraperitoneal injections of LH-RH or its superactive analog des-Gly10[D-Ala6]LH-RH-ethylamide (LH-RHA DAla6). The peptides injected at dosages of 1.0 or 0.2 mg LH-RH and 0.2 or 0.02 mg LH-RHA DAla6/kg bw elevated plasma GtH by 1.5 hr postinjection. The response to the analog was of longer duration. Plasma GtH levels returned to basal levels 24 hr following LH-RH injection while elevated plasma GtH levels were maintained for at least 96 hr in response to the analog. Only those fish injected with LH-RHA DAla6 showed an accelerated rate of germinal vesicle breakdown (GVBD). Based on their relative effects on GVBD, LH-RHA DAla6 has at least 50 times the biological potency of LH-RH in adult female coho salmon.

Animals↗
PubMed1983

Assaying addiction liability of opioids.

A number of procedures are available to assess an opioid's capacity to be positively reinforcing, but each has limitations that could lead to the false conclusion of no addiction potential. The recently developed conditioned place preference (CPP)-test, however, overcomes some of these limitations. Diprenorphine can be used to establish a CPP indicating it has an unsuspected capacity to elicit positive affect. Since diprenorphine antagonizes opioid analgesia and elicits signs of positive affect, the conclusion is confirmed that opioid analgesia and opioid's capacity to be positively reinforcing are separable.

Animals↗
PubMed1983

A colorimetric assay for the measurement of the sensitivity of herpes simplex viruses to antiviral agents.

A quantitative colorimetric method for measuring the inhibition of viral cytopathic effects has been adapted to the assay of antiviral compounds. Drug-treated, virus-infected cultures in microtiter plates were stained with the vital dye neutral red and the amount of dye incorporated was determined in a multichannel spectrophotometer. The technique required smaller volumes of reagents, was more easily automated than the standard plaque reduction assay and had good reproducibility. Standard conditions of 30 infectious units of challenge virus and 72-h incubation were judged to be optimal. Median inhibitory concentrations (ID50) for a number of compounds were approximately tenfold higher in the dye-uptake assay compared with the plaque reduction assay, possibly related to the higher multiplicity of infection required to give the desired level of cytopathic effect in the microtiter method.

Antiviral Agents↗