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Biomedical subjects

R A James

Publications and source records attributed to R A James.

At least 91 records · Page 5Linked to original sources
PubMed1991

Carbohydrate tolerance and serum lipids in acromegaly before and during treatment with high dose octreotide.

Carbohydrate tolerance and serum lipids were studied in 14 patients with acromegaly before and in response to treatment with high dose somatostatin analogue (octreotide) over a 14-week period. Patients were assessed with respect to growth hormone (GH) profile, IGF1, HbA1, fasting lipids, and the GH, glucose, and insulin response to a standard 75 g oral glucose tolerance test (OGTT) before and during therapy. Prior to treatment mean fasting serum insulin levels were 11.7 +/- 2.8 (+/- SE) mU I-1 with a mean insulin response to OGTT of 49.8 +/- 10.8 mU I-1. Twelve of the 14 patients responded to octreotide with a reduction in mean 24-h serum GH (32.9 +/- 9.3 to 4.3 +/- 0.9 mU I-1), suppression of GH at 60 min during OGTT (3.0 +/- 0.8 mU I-1) and normalization of serum IGF1 (71 +/- 7 to 27 +/- 3 (normal 9-48 nmol I-1)). In this group the fasting insulin levels fell to 2.2 +/- 0.7 mU I-1 (p less than 0.01), and mean insulin response during OGTT was reduced (46.6 +/- 15.0 to 12.3 +/- 2.3 mU I-1) (p less than 0.01). Despite the reduction in insulin secretion there was no significant deterioration in fasting blood glucose (4.8 +/- 0.2 vs 4.6 +/- 0.4 mmol I-1), HbA1 (7.2 +/- 0.3 vs 6.8 +/- 0.3%) or mean blood glucose response to OGTT (7.9 +/- 0.7 vs 8.2 +/- 0.5 mmol I-1). Fasting triglycerides were reduced with treatment from 1.5 +/- 0.2 to 1.1 +/- 0.1 mmol I-1 (p = 0.04) in the responsive group, but serum cholesterol levels were not significantly altered (5.3 +/- 0.3 vs 5.2 +/- 0.3 mmol I-1).

Acromegaly↗
PubMed1991

Severe diabetic retinopathy at presentation in a young man.

A 22 year old man presented with a severe ischaemic diabetic retinopathy and, in spite of photocoagulation therapy, was blind in one eye 16 months after diagnosis. Four similar cases of aggressive diabetic retinopathy are reviewed. There is increasing evidence that a small group of young men with insulin dependent diabetes (IDD) may develop severe diabetic retinopathy at, or soon after, diagnosis.

Adult↗
PubMed1991

Effects of insulin-like growth factor-II on growth hormone release from human somatotrophinoma cells in vitro.

Insulin-like growth factor-I (IGF-I) and IGF-II receptors have previously been demonstrated on membranes prepared from human somatotrophinomas. IGF-I has been shown to have a variable effect on GH secretion by these tumours in vitro. The effects of purified IGF-II on GH secretion have not been described. We have studied the direct actions of human recombinant IGF-II on GH release from eight somatotrophinomas cultured in vitro. Somatotrophinoma cells were cultured as monolayers at a density of 10(5) cells/0.5 ml. Treatment with IGF-II for 4 and 24 h resulted in discrete inhibitory effects on GH release from two tumours (tumour 5: 4 h, IGF-II 0.5 nmol/l; tumour 2; 24 h, IGF-II 1 nmol/l). Treatment with IGF-II for 24 h resulted in significant inhibitory effects on GH release from one tumour over a range of concentrations tested (IGF-II 0.5-10 nmol/l). Addition of human GH-releasing factor (hGRF) (1-44) (20 nmol/l) for 4 and 24 h resulted in stimulation of GH release by five tumours. Two tumours demonstrated significant inhibitory effects of IGF-II on GRF-stimulated GH release (tumour 2: 24 h, IGF-II 1-5 nmol/l; tumour 3; 4 h, IGF-II 5 nmol/l; 24 h, IGF-II 0.5-50 nmol/l). These data emphasize the heterogeneity of somatotrophinomas in terms of their response to modulators of GH secretion. IGF-II does not appear to have a modulatory role on GH release by most somatotrophinomas.

Adult↗
PubMed1991

The histologic evaluation of the implant interface with heterograft and allograft materials--an eight-month autopsy report, Part II.

This paper presents post mortem histologic specimens of the implant/osseous tissue interface from a patient who had had simultaneous bilateral maxillary sinus augmentation and root-form implant placement eight months prior. Two implants were observed: One implant was totally submerged in bone and graft material (2E), and other implant (3E) was devoid of bone at the apex. Microscopic examination revealed that a bony interface existed around implant 2E but that implant 3E had minimal bony interface. It is suggested that the minimal bony interface was the result of minor implant movement induced by variations in barometric pressure on the apex of implant 3E, and that eight months would not have been enough healing time prior to loading for this patient.

Atmospheric Pressure↗
PubMed1990

Administration of high-dose octreotide (Sandostatin) by continuous subcutaneous infusion for the treatment of acromegaly.

Patients with active acromegaly were treated with octreotide (SMS 201-995, Sandostatin; Sandoz Pharmaceuticals) given in high dosage by continuous subcutaneous administration (CSI). Serum growth hormone (GH) and insulin-like growth factor 1 (IGF-1) concentrations were rapidly and consistently reduced to the normal range and maintained for up to 14 weeks of study. Maximal inhibition of GH and IGF-1 secretion was obtained at a dose of 600 micrograms/24 h; all except 1 of the 7 patients were able to tolerate a higher dose of 1,600 micrograms/24 h. A single patient failed to show GH suppression at any dosage of octreotide. Computed tomographic evidence of tumour shrinkage was not demonstrated in these 7 patients, although in 2 patients subsequently studied by us definite tumour shrinkage was observed. These data show that the administration of octreotide by CSI is a highly satisfactory method for persistently lowering GH and IGF-1 concentrations in acromegalic patients sensitive to this drug.

Acromegaly↗
PubMed1990

Suspension mechanism of subperiosteal implants in baboons.

It has been noted that overloading of an implant can lead to the premature loss of implants (Jones et al., 1979; Travis and Jones, 1986). An understanding of the mechanism by which subperiosteal implants support masticatory loads could lead to appropriate design changes for best utilization of this mechanism and thus increase the predictability of subperiosteal implants (James, 1983). This study attempts to analyze the suspension mechanism in implants recovered from a baboon after 10 years' use.

Animals↗
PubMed1990

Acalculous cholecystitis due to Salmonella virchow.

We report a case of systemic infection with Salmonella virchow in a 21-year-old male who subsequently developed acalculous cholecystitis. His symptoms and signs-resolved with parenteral antibiotics, as did the ultrasonographic findings in the gall bladder. To our knowledge, this is the first reported case of acalculous cholecystitis due to this serotype.

Acute Disease↗
PubMed1989

Continuous infusion of octreotide in acromegaly.

15 patients with acromegaly were treated with continuous subcutaneous infusion of octreotide in increasing dose from 200 to 1600 micrograms per 24 h by 200 micrograms increments each week. Patients were studied during the initial 7 h of infusion, weekly at each dose level, then after 1 and 2 months at maximum dosage. 13 patients responded well, as judged by growth hormone (GH) suppression and return of insulin-like growth factor 1 to normal, although 1 patient withdrew due to adverse effects; 2 patients showed no significant reduction in GH. In the 12 responders GH level fell within the first 3 h of infusion at a mean plasma octreotide level of 0.76 (SE 0.26) micrograms/l, corresponding to 25 micrograms of infused drug. Optimum suppression of GH occurred at a dosage of 600 micrograms per 24 h, a plasma drug level of 3.5 (0.5) micrograms/l. A definite reduction in tumour size was seen on computerised tomographic scan in 2 patients. All responders noted subjective improvement in acromegalic symptoms. Adverse effects comprised gastrointestinal disturbances, which were transient and mild in 14 patients but severe in 1; biliary sludging occurred in 1 patient. No significant deterioration in carbohydrate tolerance was seen in the responders.

Acromegaly↗
PubMed1989

Road crash cervical injuries. A radiological study of fatalities.

A lateral radiograph of the cervical spine was obtained for 174 of the 207 persons killed in road crashes in Adelaide, South Australia, during the 12-month period of June 1, 1987 to May 31, 1988. Of the total of 57 cases of cervical injury, routine postmortem examination identified 30 cases (52.6%), and the radiographic examinations identified 51 cases (89.5%). In the cases where it was performed, radiography identified 96.2% of injuries. One-half of injuries of level C3 and above were not reported at postmortem examination, compared with 22% of those occurring below this level. This finding correlates with the physical difficulties of examining the upper part of the cervical spine. This study has shown that lateral cervical radiography is a simple and effective method of more accurately identifying significant cervical spinal injuries, thus improving greatly the value of postmortem examinations in determining the patterns and mechanisms of these injuries.

Accidents, Traffic↗