Section II: General orthopaedics. Anterior cervical fusion for trauma.

Anterior bone grafts of 24 injured cervical spines were reviewed with respect to early postoperative instability and eventual malunion. Spinal redislocation or graft extrusion occurred in 21% representing failure to attain early stability. In 38%, the late complication of kyphotic malunion occurred, averaging 21%. The Yale instability criteria were fulfilled in 15 cases and mechanical complications developed in 87% of these. When posterior instability was present, the mechanical complication rate rose to 92%. Early stabilization of most neck injuries is not achieved by the anterior bone graft and its use as a means of "stabilization" is unsubstantiated by clinical experience.     

Effects of hydration and dehydration on body composition analysis: a comparative study of bioelectric impedance analysis and hydrodensitometry.

Since 1983, bioelectric impedance has been researched with respect to its validity and reliability in the determination of body composition. It continues to be compared to hydrostatic weighing, the anthropometric "gold standard". This study was designed to investigate the relationship between bioelectric impedance analysis (BIA) and hydrodensitometry (HW) under three conditions: control, hydration and dehydration. Caucasian males (aged 18-44 years) served as subjects (n = 10). Body composition was determined by BIA and HW before intervention, 30 minutes post-hydration, and following a combination of exercise and sitting in a steam room to decrease body weight by two to four percent (mean = 2.81%). Statistical treatment by two-way analysis of variance for repeated measures revealed that although there were no significant differences between the two techniques of body composition determination under any of the three conditions, there was a statistically significant decrease in percent body fat determined in the dehydrated state as compared to the control and hydrated conditions. Recommendations include the determination of hydration state prior to engaging in body composition analysis by either method.     

Growth hormone secretagogue activation of the arcuate nucleus and brainstem occurs via a non-noradrenergic pathway

Noradrenergic systems are integrally involved in the release of growth hormone (GH) from the anterior pituitary gland and in regulating the activity of hypothalamic growth hormone-releasing hormone (GHRH) neurones. GH secretagogues act at both the pituitary and the hypothalamus to facilitate the release of GH. In male rats, using the induction of Fos protein as an indicator of neuronal activation, we examined whether neurones in the brainstem, the main noradrenergic input to the hypothalamus, were activated by systemic administration of peptide and non-peptide GH secretagogues. In addition, we examined the effects of chronic central noradrenaline depletion upon GH secretagogue-induced activation of the arcuate nucleus. Systemic injection of the GH secretagogues, GHRP-6 and MK-0677 induced Fos protein expression in a population of area postrema cells, but less than 10% of these cells were noradrenergic. Depletion of hypothalamic noradrenaline by the specific neurotoxin, 5-ADMP, did not alter GH secretagogue-induced activation of Fos protein in the arcuate nucleus compared to vehicle-treated controls. We conclude that the central actions of GH secretagogues involve the activation of non-noradrenergic cells in the area postrema and that GH secretagogue-induced activation of the arcuate nucleus occurs independently of noradrenergic tone.     

Serotonergic and noradrenergic function in depression: clinical correlates

The present study was conducted in order to investigate the relationships between central noradrenergic (NA) and serotonergic (5-HT) function and clinical characteristics of a major depressive episode according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. We measured growth hormone response (ΔGH) to clonidine (CLO) (an α2 NA agonist), as an index of central NA function, and prolactin response (APRL) to d-fenfluramine (d-FEN) (a specific 5-HT releaser/uptake inhibitor), as an index of central 5-HT function, in 53 medication-free depressed inpatients. On the basis of their CLO and d-FEN test responses, patients were classified into 4 groups. Group 1 (blunted ΔPRL(d-FEN) alone [11 %]) was characterized by a recent violent suicide attempt, a high degree of medical damage, and mild anxiety. Group 2 (blunted ΔGH(CLO) alone [32%]) was characterized by an absence of a history of suicide attempt and by severe anxiety. Group 3 (combination of blunted ΔGH(CLO) and APRL(d-FEN) [18%]) was characterized by a history of suicide attempts, total duration of the illness of over W years, age over 40 years, and more than 3 previous hospitalizations. Group 4 (no abnormality [39%]) had no specific clinical profile. These results suggest that, in depression, specific psychopathological features may be linked to 5-HT and/or NA dysfunction. However, our results also suggest that NA and/or 5-HT dysfunction are less likely to be the primary cause of mood disorders but are more indicative of failure of compensatory mechanisms involved in affective homeostatic processes.     

Phase II study of 1alpha-hydroxyvitamin D(2) in the treatment of advanced androgen-independent prostate cancer.

PURPOSE: In this single institution Phase II trial, we evaluated the efficacy of the vitamin D analogue, 1alpha-OH-D(2), in patients with advanced hormone-refractory prostate cancer. Experimental Design: The patients initially received 1alpha-OH-D(2) at 12.5 micro g p.o. every day, which was dose adjusted for hypercalcemia. Given the cytostatic nature of the drug, the primary study end point was progression-free survival for a minimum of 6 months. The secondary end point was further characterization of drug toxicity. RESULTS: A total of 26 patients was enrolled. Using the intent-to-treat population, stable disease was seen for an average of 19.2 weeks (median 12 weeks, range 3-108 weeks). Twenty patients were evaluable for response. The one patient that achieved disease stabilization for >2 years elected to come off-study because of patient preference. His last disease evaluation showed no evidence of progression. No objective responses were seen. Previous and ongoing clinical observations strongly imply that PSA could be a misleading surrogate marker for clinical effect with this type of drug. Therefore, prostate-specific antigen was not used as a marker for disease response. Toxicity was as expected with mild hypercalcemia and associated symptoms like constipation and prerenal azotemia seen in some patients. Six (30%) evaluable patients experienced stable disease for >6 months, suggesting possible cytostatic activity. CONCLUSION: The results of this and other trials suggest further clinical investigation in this disease with vitamin D analogues alone or in combination with other agents, such as chemotherapy, should be pursued.     

The efficacy of acarbose in type 2 diabetes mellitus in Jamaica

The efficacy and tolerability of acarbose was studied in type 2 diabetic patients eating a typical Jamaican diet. The study was an open label parallel group study without placebo control. Of the 51 subjects recruited, five (9.8%) did not complete the study and were excluded from further analysis. Six (13%) of the remaining 46 had adverse side effects and did not complete the protocol. Of the remaining 40 (Gp A), acarbose was added to their previous regime of diet alone (n = 15), [Gp B], oral hypoglycaemic agents, OHAs (n = 17), [Gp C], or insulin (n = 8), Gp D]. In addition, during the run-in period all subjects had one session each with a dietitian and a diabetes educator. Over a 3-month period, significant reductions in average glucose (mmol) were observed in Gp B 10.5 +/- 1.1 to 8.4 +/- 0.9 (p < 0.027) and, from 11.0 +/- 1.0 to 8.7 +/- 0.7 (p < 0.01) in Gp C. Similarly, total glycosylated haemoglobin fell from 14.8 +/- 1.1% to 12.2 +/- 1.0% (p < 0.016) in Gp B, from 14.9 +/- 1.1 to 11.9 +/- 1.1% (p < 0.002) in Gp C, and from 14.1 +/- 1.4 to 11.8 +/- 1.4 (p < 0.02) in Gp D. Twenty-three per cent (23%) of the patients experienced flatulence; 7.5%, changes in bowel habits and 5%, abdominal cramps and discomfort. Acarbose is effective as monotherapy and as combination therapy with oral hypoglycaemic agents or insulin. Side effects were common, but tolerable.     

Impact on blood pressure control of a six-month intervention project

The aim of this study is to evaluate the impact of a six-month structured education programme on blood pressure (BP) control in patients with uncontrolled hypertension. All patients attending the Specialist Hypertension Clinic, University Hospital of the West Indies (UHWI), between January 4 and March 29, 1999, with blood pressure > 140/90 mmHg (n = 80), were randomly divided into Group 1, cases (n = 42) and Group 2, controls (n = 38). A 40-item pretested questionnaire, administered at the baseline and final visits of both groups, elicited demographic, lifestyle and knowledge data. Group 1 attended monthly structured interventions for six months. Except for diastolic blood pressure among male controls, diastolic blood pressure and systolic blood pressure were significantly reduced at the end of the intervention period (p < 0.01). Knowledge improved among the male patients (p < 0.01). Among the female patients, activity scores were significantly increased (p < 0.01), weight (p < 0.05) and BMI (p < 0.05) were significantly reduced. There were no differences in these variables among the controls. This intervention had a benefit in blood pressure control.