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Biomedical subjects

M Gregory

Publications and source records attributed to M Gregory.

18 recordsLinked to original sources
PubMed1990

A clinical study of the Brånemark dental implant system.

A clinical study using the Brånemark dental implant system was carried out on 13 patients aged 41 to 68 years. Clinical and psychological effects of treatment were assessed at 6-monthly intervals over a period of 3 years by means of a clinical examination, a personality assessment using Cattell's 16 PF Questionnaire and a general subjective questionnaire. Six per cent of implants failed to osseointegrate. Fifty per cent of bridges became loose, but remained stable after retightening. A similar percentage of fractures occurred, mainly teeth separating from acrylic gumwork. There was some soreness of peri-implant mucosa, particularly on cleaning. Despite these problems, there was considerable evidence of improved well-being of patients, who felt more secure following treatment and, as a result, their personal and social relationships improved.

Adult↗
PubMed1990

Response to nondepolarizing muscle relaxants in children with tumours.

The rate of onset of action of d-tubocurarine (64 patients) or alcuronium (36 patients) was studied electromyographically in 100 children who had abdominal, bone or cerebral tumours. It was found that there was a significantly delayed onset (over three times longer than controls) or additional doses were required in patients with malignant liver, renal and bone tumours who received d-tubocurarine. The onset of alcuronium blockade was also prolonged but to a lesser extent. When tumours with an abnormal prolongation of onset of relaxation were successfully treated by chemotherapy and/or surgery, the response reverted to normal. Children with benign tumours or masses had normal responses. In contrast, neuroblastomas were associated with little prolongation of onset. Cerebral tumours showed a variable response, with the observed changes being unreliable indicators of degree of malignancy.

Adolescent↗
PubMed1990

Finite element analysis of fixed prostheses attached to osseointegrated implants.

The effect of defined stresses on cantilevered prostheses attached to osseointegrated implants was assessed by finite element analysis. The effect of stress on a cantilever, consisting of a ductile alloy in contact with a brittle polymer, was demonstrated to be complex. The distribution of applied stresses also influenced the results. Possible fracture and distortion of both materials were demonstrated. Finite element analysis is a particularly useful system for predicting stress behavior and can be employed to produce an optimal prosthetic design that reduces the potential for clinical failure.

Acrylic Resins↗
PubMed1989

Clonidine transdermal patches for use in outpatient opiate withdrawal.

We conducted a study to assess the clinical usefulness of transdermal clonidine for heroin detoxification in an outpatient drug treatment clinic. Twenty-two young otherwise healthy heroin addicts participated. Outcome was assessed on the basis of (a) hypotension and other side effects of clonidine; (b) patient retention; (c) concomitant drug use; (d) subjective symptoms of withdrawal; and (e) objective signs of withdrawal. Side effects were present but in no case necessitated discontinuation of treatment. Drop-out rates were equal to conventional treatment offered at the clinic. The availability of clonidine broadens the therapeutic options available to patients and clinicians in treating the opiate-addicted patient. Transdermal clonidine offers several advantages over the oral form: patches can be applied weekly, fewer supplemental medications are required, and patches supply an even blood level of medication. A protocol for use is recommended.

Administration, Cutaneous↗
PubMed1989

Insulin and renal sodium retention in obese adolescents.

The effect of insulin on the renal handling of sodium was studied in obese and nonobese subjects by using euglycemic hyperinsulinemia. Seven water-loaded obese (14-19 years old) and five nonobese young adults (18-21 years old) had insulin given intravenously at a rate of 40 munits/m2/min. Blood glucose and creatinine clearance were not altered by euglycemic hyperinsulinemia in either the obese or the nonobese group. Hyperinsulinemia resulted in a significant decrease in urinary sodium excretion in both groups of subjects (by 54.2 +/- 3% [mean +/- SEM] in the obese and by 50.9 +/- 3.1% in the nonobese group). However, the amount of glucose required to maintain euglycemia was significantly less in the obese versus nonobese group, 89.5 +/- 6.2 versus 329.2 +/- 16 mg glucose/m2/min (p less than 0.001). There was no relation in either group between the amount of glucose required to maintain euglycemia and the change in urinary sodium excretion. On a separate day, all of the obese subjects underwent 3 hours of water diuresis but without insulin. There was no change in urinary sodium excretion with sustained water diuresis alone. However, when compared with the nonobese group, the obese group of subjects had a significantly higher resting mean arterial pressure, heart rate, and plasma norepinephrine concentration; during the insulin clamp, neither group experienced a significant change in mean arterial pressure or heart rate, and only the nonobese group experienced an increase in plasma norepinephrine. In obese subjects, we have found, despite the presence of insulin resistance to carbohydrate metabolism, that euglycemic hyperinsulinemia was associated with a normal decrease in urinary sodium excretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Teaching lip-reading: the efficacy of lessons on video.

Studies of the efficacy of filmed and videotaped materials for lip-reading self instruction have provided encouraging results. The recent increase in private ownership of VCRs allows widespread home use of video lessons for improving lip-reading skills. Such an approach is particularly, useful for hearing-impaired adults who have no access to lip-reading classes. To fill this need in Australia a 3-hour video cassette of nine lip-reading lessons was produced. The video lessons were tested over a period of 5 weeks. The study showed a significant improvement in the lip-reading skill of students who studied the video cassette compared to a control group who did not. The extent of improvement did not differ for students who studied the video in a class, at home, or as supplementary teaching material. While the age and sex of the subjects did not influence improvement of lip-reading skills, the study showed greater improvement for the relatively poorer lip-readers. More detailed testing of one group of students showed generalization of lip-reading skills to unfamiliar speakers and materials.

Adult↗
PubMed1979

Metabolic clearance and plasma half-disappearance time of exogenous somatostatin in man.

The MCR and half-disappearance time of exogenously administered somatostatin have been measured during and after cessation of a constant infusion. Studies were performed on normal volunteers and patients with chronic liver disease and failure. Immunoreactive somatostatin was measured by a sensitive and specific RIA using an antiserum directed against the core of the molecule. Normal subjects had a mean MCR of 1949 +/- 250 ml/min (28.4 +/- 4.2 ml/min . kg BW) (mean +/- SEM), similar to values found in five patients with chronic liver disease. However, patients with chronic renal failure showed a highly significant (P less than 0.001) lowering of the MCR (501 +/- 32.7 ml/min or 7.8 +/- 0.6 ml/min . kg). The rate of disappearance of somatostatin after infusion was linear for 7-10 min, after which a much slower component was observed. In normal subjects, the t 1/2 of the first component varied from 1.1-3.0 min, in patients with liver disease it varied from 1.2-4.8 min, and in patients with chronic renal failure it varied from 2.6-4.9 min. Exogenously administered somatostatin is rapidly cleared in normal subjects and patients with chronic liver disease, but the MCR in end stage chronic renal failure is markedly lowered. The kidney may have a role in the metabolic clearance of exogenously administered somatostatin, or uremia may impair catabolism nonspecifically.

Adult↗
PubMed1976

Study of autogenous transposed ossicles, bone and cartilage in man.

Study was made of 28 ossicles from 22 ears with chronic otitis, 12 autogenous transposed ossicles removed after varying periods of time, normal and 4 transplanted pieces of bone, and normal and 2 transplanted pieces of cartilage. The transposed ossicles were found to be dead, apart from certain special instances, showing pathology similar to non-transposed ossicles. Transplanted bone was also dead. Cartilage was vital. These autogenous transplants showed no evidence of rejection and less chronic inflammation than would be anticipated. It is suggested that autogenous ossicular or bone transplants in man act as inert but not rejected implants, while cartilage may remain viable.

Bone Transplantation↗
PubMed1975

The Budd-Chiari syndrome: correlation between hepatic scintigraphy and the clinical, radiological, and pathological findings in nineteen cases of hepatic venous outflow obstruction.

From 1965 to 1972, 19 patients with the Budd-Chiari syndrome were investigated. An underlying diagnosis was made in 10 cases, polycythemia rubra vera being the commonest etiology. Percutaneous liver biopsy confirmed the diagnosis in 18 patients, and in 14 the site of hepatic vein obstruction was defined or its presence suggested by hepatic venography. Hepatic scintiscanning showed predominant central localization of radiocolloid in 7 patients. In another 8 patients this appearance was present in association with other less specific features. These findings were correlated with inferior vena cavography in 13 patients in whom a characteristic narrowing and distortion of the vein throughout its intrahepatic course was noted. In 3 other patients, the vein was found to be occluded. Autopsy evidence in 6 patients suggests that the central concentration of radiocolloid on scintiscanning and the narrowing and distortion of the inferior vena cava were due to disproportionate enlargement of the caudate lobe. Additional studies indicated that the separate venous drainage of the caudate lobe may be preserved when the main hepatic veins are occluded and that hypertrophy of the caudate lobe occurs because of its relatively more efficient perfusion. Demonstration of the enlarged caudate lobe by scintiscanning and inferior vena cavography provides valuable diagnostic support for the Budd-Chiari syndrome.

Adult↗
PubMedDate not supplied

Improved surveillance of maternal deaths.

This study explains and verifies an apparent increase in the New Jersey resident maternal mortality rate from 1.7 per 10,000 live births by the state's traditional method to 3.1 per 10,000 live births by a new method of surveillance instituted in late 1974. In 1975, the maternal mortality rate by the traditional method was 1.5 per 10,000 and by the expanded method, 3.0 per 10,000. The traditional method compiled data from death certificates submitted to the State Vital Statistics Office. The expanded method found additional deaths by review of Annual Maternity Services Reports from hospitals and by close follow-up of individual reports of maternal deaths from medical examiners, physicians and hospitals.

Adolescent↗
PubMedDate not supplied

Platelet serotonin uptake in panic disorder.

Platelet serotonin uptake was measured in 45 patients (12 males, 33 females) with panic attacks and 21 controls (9 males, 12 females). Higher Vmax values were obtained in the patient group than in the controls (100.2 +/- 11.5 vs. 34.9 +/- 3.8 pmol/10(8) platelets/min; P less than 0.0005) while the affinity constant Km was not significantly different (2.28 +/- 0.3 vs. 1.71 +/- 0.18 microM). A value of Vmax in excess of 60 pmol/10(8) platelets/min was observed in 60% of patients and in only 5% of controls. The results point to a specific abnormality of platelet serotonin uptake in patients with panic attacks.

Adult↗