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Biomedical subjects

J M Hunter

Publications and source records attributed to J M Hunter.

At least 109 records · Page 6Linked to original sources
PubMed1987

Use of neostigmine in the antagonism of residual neuromuscular blockade produced by vecuronium.

Recovery from neuromuscular block produced by vecuronium was studied in 50 patients using electromyography and the train-of-four technique. Twenty patients received neostigmine 2.5 mg, 10 when the initial response of the train-of-four was 50% of control and 10 when it was 10%. Neostigmine 5 mg was investigated in a similar manner and in 10 patients spontaneous recovery was studied. In all patients the time to 70% recovery of the initial response and of the train-of-four ratio was followed. Neostigmine significantly reduced the time to 70% recovery of both ratios with both degrees of block, but neostigmine 5.0 mg did not give a substantially more rapid recovery than 2.5 mg. No evidence of a neostigmine-induced block was encountered. neostigmine 2.5 mg was rapidly effective in antagonizing vecuronium-induced block, even when initial recovery was only slight: there was no advantage in using neostigmine 5.0 mg.

Adult↗
PubMed1987

Potentiation of the neuromuscular blockade produced by alcuronium with halothane, enflurane and isoflurane.

The potentiation of alcuronium by halothane, enflurane and isoflurane was investigated using electromyography. In the first study, cumulative dose-response curves were constructed in four groups of 10 patients anaesthetized with one of the inhalation agents and nitrous oxide, or with fentanyl and droperidol (control). All three agents reduced the ED50 of alcuronium; the effect was marked with isoflurane (P less than 0.005) but less so with halothane (P less than 0.05) and enflurane (ns). In the second part of the investigation, designed primarily to test the duration of action of alcuronium with each agent, a single bolus dose of alcuronium 0.2 mg kg-1 was given to four similar groups (n = 5). The duration of action was significantly prolonged by enflurane (P less than 0.01) and isoflurane (P less than 0.05), but not by halothane. The possible reasons for this are discussed.

Action Potentials↗
PubMed1987

Vecuronium infusions in patients with renal failure in an ITU.

The use of an infusion of vecuronium is described in seven patients with renal and respiratory failure in an intensive therapy unit. Neuromuscular function was monitored throughout using the train-of-four twitch technique. A bolus dose of vecuronium (0.1 mg/kg) was given, followed immediately by a continuous infusion (0.05 mg/kg/hour). The infusion rate was adjusted until the first twitch of the train was below 20% of control and then run at a constant rate. There was a marked variation in the dose of vecuronium administered (0.01-0.065 mg/kg/hour [corrected]). Two patients, who appeared to be most sensitive to the drug, were both receiving metronidazole. Recovery of neuromuscular function was extremely prolonged and widely variable (6-37 hours) on stopping the infusion. No adverse cardiovascular effects or evidence of histamine release were seen as a result of administration of the drug. Vecuronium is probably more suitable for administration in bolus doses rather than by infusion in patients with renal and respiratory failure.

Acute Kidney Injury↗
PubMed1987

Prolonged paralysis following an infusion of alcuronium in a patient with renal dysfunction.

The case is described of a patient who underwent artificial ventilation in an intensive therapy unit and received an infusion of alcuronium 10 mg/hour for more than 4 days, in the presence of significant renal (and later, some degree of hepatic) impairment. Prolonged and profound neuromuscular block persisted despite haemodialysis (5 hours on each of 3 days) followed by 72 hours of continuous haemofiltration; it appeared to resolve only after plasma exchange (4 litres). The total of persistent block, for 9 days after the infusion had been stopped, is thought to be the longest period ever reported after administration of alcuronium. Neuromuscular block was monitored throughout this period using the train-of-four twitch technique. The potentiating effects of concurrent aminoglycoside therapy and hepatic dysfunction on the degree of paralysis are discussed.

Alcuronium↗
PubMed1987

Atracurium infusions in major ophthalmic surgery.

Fifteen patients who were undergoing major ophthalmic surgery were anaesthetized using controlled ventilation with nitrous oxide, oxygen, midazolam and fentanyl after induction with thiopentone. Each was then given a bolus dose of 0.6 mg kg-1 atracurium followed immediately by an infusion of the drug at the rate of 0.6 mg kg-1 h-1, neuromuscular function being monitored throughout. Even slight movement can jeopardize the success of this type of surgery but good control of neuromuscular blockade was achieved without inhalational supplementation. The mean duration of the atracurium infusion was 118 min (range 30-247 min). The mean time from stopping the infusion to recovery of the first twitch of the train of four (TOF) to 20% was 25 min (range 11-44 min). Atropine (1.2 mg) and 5.0 mg neostigmine were then given in divided doses and a rapid and complete recovery was achieved. This technique can be used safely even in bad-risk patients but the infusion should be discontinued about 25 min before the end of surgery.

Adult↗
PubMed1986

Single stage lengthening by intercalary bone graft in patients with congenital hand deformities.

The experience with single-stage lengthening by intercalary bone graft in four patients with congenital hand deformities is presented. In all seven lengthenings the gap was bridged by a toe phalanx bone graft. The elongation of the ray ranged from 5-14 mm. Examination of patients followed from one to five years after the treatment showed a good appearance of the lengthened ray. One bone graft assimilation resulted in a pseudoarthrosis and another had osteopenia that resolved spontaneously. All others healed uneventfully. The quality of the skin sensitivity, vascular status and tendon balance is preserved after the lengthening.

Bone Lengthening↗
PubMed1986

Rings of madness: service areas of 19th century asylums in North America.

The mid-19th century saw the emergence of a major medical innovation, namely, the rise of the state lunatic asylum. Beginning in the northeast, the phenomenon spread rapidly westwards. By 1875 no fewer than 71 mental hospitals were opened in 32 existing states. Although premised upon belief in the efficacy of 'moral and humane' treatment, the asylums soon became custodial rather than therapeutic institutions. Average size continually increased; some accommodated well over 2000 patients. The provision of more asylums, and broadened definitions of insanity, generated increasing patient numbers which, in turn, caused public consternation and fear of increasing 'madness' in the population. Geographic analysis of admissions in 18 U.S. states and two Canadian provinces reveals the universality of distance decay around the asylums, and demonstrates that hospital service-area cones were predominantly local in effect. Thus the 'state' asylum was in reality a local institution. The deinstitutionalization movement of recent decades is apparently bringing to a closure a 100-year cycle of incarceration-decarceration of the mentally ill. Nevertheless, whether patients are geographically concentrated or dispersed, the influence of distance decay remains a relevant consideration.

History, 19th Century↗
PubMed1986

Effect of vesicle size on the clearance, distribution, and tumor uptake of temperature-sensitive liposomes.

The blood clearance, tissue distribution, and tumor uptake of temperature-sensitive liposomes containing the anticancer drug cytosine [3H]-1-beta-D-arabino-furanoside (Ara-C) or [3H]-methotrexate (MTX) were measured. Large unilamellar liposomes composed of a mixture of dipalmitoylphosphatidylcholine and dipalmitoylphosphatidylglycerol (4:1 by weight) were formed by reverse-phase evaporation and sequentially extruded through polycarbonate membranes with pore sizes of 0.4, 0.2, 0.1, 0.08, and 0.05 micron. The liposomes were injected intravenously via the tail vein into B6D2F1 mice containing solid tumors (M5076 ovarian carcinoma) implanted in both hind feet. Drug release, organ distribution, and tumor uptake were studied during and following local hyperthermia treatments (42 degrees C, 60 minutes). Local hyperthermia increased the relative amount of liposome encapsulated drug delivered to a heated solid tumor compared with the unheated control. The clearance studies showed that liposome blood clearance was inversely proportional to liposome size. However, tumor uptake was not significantly affected by reducing liposome size. In addition, for the range of liposome sizes studied, the majority of the liposome encapsulated drug was found in the liver, spleen, and kidney; not in the heated tumor.

Animals↗
PubMed1986

Atracurium infusions in patients with renal failure on an ITU.

An infusion of atracurium was used (after an initial bolus dose) in five patients with renal and respiratory failure, who were being subjected to intermittent positive pressure ventilation before renal dialysis. Neuromuscular function was monitored by the train-of-four pattern of stimulation. In three patients, atracurium 0.6-0.7 mg/kg/hour completely abolished the twitch response; in the other two (both of whom were markedly oedematous) this did not occur, even with a dose of 1.0 mg/kg/hour, although satisfactory clinical control was obtained. In all patients, there was rapid spontaneous recovery when the infusion was stopped. One patient convulsed, but plasma laudanosine levels taken at this time were below the toxic range. Atracurium infusions appear to provide easily controllable neuromuscular blockade in the intensive therapy unit, although these preliminary results suggest that larger doses may be required in the oedematous patient.

Acute Kidney Injury↗
PubMed1986

Philosophy of hand rehabilitation.

This article is an introduction to the history and philosophy of hand surgery and hand therapy. Case histories illustrate the basic principles and goals of hand rehabilitation. The importance of the team approach in the successful management of hand injuries is emphasized.

Adolescent↗
PubMed1986

Two-stage flexor-tendon reconstruction. Ten-year experience.

One hundred and fifty fingers in 136 patients were treated by a two-stage flexor-tendon reconstruction and followed for an average of 2.4 years. A salvage procedure such as this was needed for most of these fingers since 81 per cent of the injuries were in Zone 2 and 45 per cent were Grade 5 in severity. Before reconstruction, the mean total active motion (all joints combined) for each finger was 102 degrees and the mean grip strength was 20 per cent of normal. At final follow-up, the mean total active motion of these fingers was 176 degrees and the mean grip strength was 79 per cent of normal. Three months after tendon-grafting, the results had reached a plateau, and no significant change occurred thereafter. Complications were a flexion contracture of varying degree in 41 per cent of the fingers, especially when a contracture was present preoperatively (40 per cent); rupture of the tendon graft in 14 per cent; and infection in 4 per cent. This review reaffirmed the usefulness of two-stage flexor-tendon reconstruction as a salvage procedure to restore function of flexor tendons.

Adolescent↗
PubMed1985

Clay eating.

In the report "Transfection of v-ras(H) DNA into MCF-7 human breast cancer cells bypasses dependence on estrogen for tumorigenicity" by A. Kasid et al. (10 May, p. 725), a line connecting two sentences was inadvertently omitted from the text. On p. 726, column 1, line 9, the sentence beginning "Densitometric scans of the blots " should have continued as follows: "showed that the transfectants expressed ras(H) RNA at levels 10 to 12 times higher than wild-type MCF-7 cells (Fig. 1E) or MCF-7(gpt) cells. Wild-type MCF-7 cells contained a low level of endogenous c-ras(H) RNA and neither its expression nor that of the exogenously acquired v-ras(H) gene was altered by E(2) treatment (Fig. 1E)."

Aluminum Silicates↗
PubMed1985

Scaling factor relating conduction velocity and transverse axon profile for nonmyelinated alimentary nerves.

The transverse area of nonmyelinated axonal profiles was measured in alimentary nerves of sheep and rabbits and compared with areas calculated from direct measurements of axon profiles taken from the same nerves. We concluded that the length of the minor axis of nonmyelinated profiles is not a suitable measurement for the calculation of transverse area or average diameter in nonmyelinated axons without the use of appropriate correction factors. Hence the scaling factor relating conduction velocity and transverse axon profile calculated from the average derived diameter is different (1.49 to 1.62) from that using the minor axis alone (0.89 to 1.26).

Animals↗
PubMed1985

Field testing along a disease gradient: some geographical dimensions of tuberculosis in Puerto Rico.

The spatial pattern of reported tuberculosis incidence in Puerto Rico is characterized by numerous high-low gradients among continguous municipios. Tuberculin testing of some 1500 subjects along one such gradient reveals that there is no difference in sensitivity and suggests that the gradients are artifacts of reporting. Correlative associations with tuberculin conversion were generally weak, except for age-dependency. Collected personal histories demonstrated that the web of familial and intergenerational relationships is a major force in perpetuating the disease. Concealment of infection, denial and poor compliance in chemotherapy regimens compound the difficulties of case-discovery and case-control. Interviews in a sample of twelve health centers confirmed that, without the presence of trained and assigned tuberculosis nurses, the health care providers' 'index of suspicion' for tuberculosis is generally low. Absence of a tuberculosis clinic virtually dictates serious under-reporting of incidence in that municipio. Despite the success of Puerto Rico's control program over past decades, a reservoir of tuberculosis persists. The level of endemicity is relatively low but unsatisfactory in the context of public health aspirations.

Adolescent↗
PubMed1985

Flexor tendon gliding in the hand. Part I. In vivo excursions.

The amplitude of gliding of the flexor tendons was measured in 36 hands tagged intraoperatively with buried wire sutures. Finger and wrist position was correlated with tendon excursion as measured on radiographs in the postoperative period. With the wrist in the neutral position, the superficialis tendon achieved an excursion of 24 mm and the profundus tendon 32 mm. Excursion of the flexor pollicis longus tendon was 27 mm. With wrist range of motion, the amplitude of the superficialis tendon became 49 mm, the profundus tendon 50 mm, and the flexor pollicis longus tendon 35 mm.

Adult↗
PubMed1985

Flexor tendon gliding in the hand. Part II. Differential gliding.

Flexor tendon gliding was studied in vivo in 48 hands. Three finger motions--straight-fist, hook, and fist--were found to provide maximum differential gliding for superficialis and profundus tendons in respect to each other, as well as in respect to the flexor sheath and bone.

Adult↗
PubMed1985

The effect of vincular injury on the results of flexor tendon surgery in zone 2.

From a consecutive series of 82 fingers (69 patients) that sustained flexor tendon lacerations in zone 2, 47 fingers (39 patients) had the status of the vincular system determined during primary repair. The vincula were intact in 22 fingers and not intact in 25. Total active motion (TAM) after rehabilitation and before a reconstructive procedure, such as repair of a rupture, tenolysis, or grafting of a tendon, was the end point of the study. The overall mean TAM was 196 degrees. The mean TAM was 222 degrees for fingers with intact vincula and 176 degrees for fingers with vincula not intact (p less than 0.01). There were no statistical differences between the two groups regarding surgical results when the number of tendons injured per finger and sheath closure were analyzed. This study suggests that the integrity of the vincular system is a determinant of end result TAM and flexor tendon lacerations in zone 2.

Adolescent↗