Formulation and in Vitro-in Vivo Evaluation of Sustained-Release Lithium Carbonate Tablets

The release of lithium carbonate incorporated into polymethylmethacrylate, poly vinyl chloride, hy-drogenated vegetable oil, and carbomer matrix tablets was studied in vitro. The formulation containing 10% carbomer showed a sustained-release profile comparable to that of a standard, commercially available, sustained-release preparation containing 400 mg lithium carbonate embedded in a composite material. In vivo the newly formulated and standard sustained-release lithium carbonate tablets were compared to an oral solution and conventional lithium carbonate tablets in 12 healthy subjects. These crossover studies showed that the sustained-release tablets produced a flatter serum concentration curve than the oral solution and conventional tablet, without loss of total bioavailability.     

Low-dose erythropoietin is effective and safe in children on continuous ambulatory peritoneal dialysis

Hypertension is one of the most important complications of erythropoietin (rHuEPO) therapy in dialysis patients. In this study, the effect of two different dosage regiments of subcutaneous rHuEPO on blood pressure [BP] was evaluated in 20 anemic children on continuous ambulatory peritoneal dialysis (CAPD). Patients were randomized to receive rHuEPO 50 U/kg, either once a week (group 1, 50 U/kg per week) or three times a week (group 2, 150 U/kg per week). At the beginning of the study, 8 patients in group 1 and 8 patients in group 2 were on antihypertensive therapy. In group 1, the hematocrit increased gradually and significantly from 18.98%±1.79% to 30.1%±1.62% after 6 months, while in group 2 it rapidly increased from 19.53%±1.86% to 32.4%±1.11% after 3 months. A significant increase in the mean arterial BP was observed in group 2. Antihypertensive therapy had to be increased in all of the 8 previously hypertensive patients and had to be initiated in 1 of the 2 originally normotensive patients in the same group. None of the patients in group 1 required a change in antihypertensive medication. We conclude that during treatment with rHuEPO pre-existing hypertension and the dose of rHuEPO are the most important risk factors for the development or worsening of hypertension in children on CAPD, and gradual elevation of hematocrit by low-dose rHuEPO avoids the development of severe hypertension. Received December 11, 1995; received in revised form September 16, 1996; accepted September 19, 1996     

Percutaneous radiofrequency rhizotomy of lumbar spinal facets: The results of 46 cases

The results of percutaneous radiofrequency rhizotomy of lumbar spinal facets in 46 patients followed at least three months (mean 15 months) are reported and compared with those reported previously. Satisfactory pain relief three months after the procedure was achieved in 36.4 percent of patients without operations and in 41.7 percent of patients with operations other than fusion.No patient had previously undergone fusion.Treatment of low-back pain by using radio-frequency thermocoagulation of spinal facets is a simple, safe, and well-tolerated procedure. It can be used to relief of pain in spite of decreasing rates of success within the follow-up period.     

Histomorphometric evaluation of the effect of doxycycline on the healing of bone defects in experimental diabetes mellitus: a pilot study.

PURPOSE: Bone healing is impaired in diabetes mellitus, particularly due to increased collagen breakdown. Recently, tetracyclines have been used to treat experimental bone defects because they have anticollagenolytic properties, and positive effects on the healing process have been obtained. The objective of this study was to develop a computer-assisted histomorphometric technique to quantitatively determine the amount of regenerating bone within experimental bone defects in a diabetic rodent model. MATERIALS AND METHODS: This study examined the effects of systemic doxycycline administration on the healing of tibial bone defects in healthy albino rats and in experimentally induced diabetic rats. Twenty-four female albino rats were assigned to 4 groups: diabetic, diabetic plus doxycycline, control, or control plus doxycycline. The standardized bone defects were histomorphometrically examined 10 and 30 days postoperatively. Histomorphometric analysis of the amount of new bone formation was performed using the Zeiss Vision image analysis program KS 400 (Kontron Elektron GmbH, Eching, Germany). RESULTS: At 10 days of healing, the diabetic groups exhibited inferior healing compared with the control groups in terms of the amount of new bone formation within the defects. However, the effect of doxycycline administration to the diabetic and control groups was not statistically different. At 30 days of healing, there were no statistically significant differences between the amount of newly formed bone in any of the groups. CONCLUSIONS: This study found that doxycycline administration did not significantly alter the amount of new bone formation during the healing of bone defects in control and diabetic rats.     

1.25 (OH)2 cholecalciferol pulse therapy and the effects of different dialysis membranes on serum PTH levels of haemodialysis patients

Either oral, intravenous or subcutaneous 1.25 (OH)₂ cholecalciferol is used in the therapy of hyperparathyroidism, which is a serious complication in patients on haemodialysis. We studied a total of 30 patients (10 women and 20 men) and divided them into two groups depending on the different types of dialysis membranes used. In the poly sulfone group, mean age was 43.7±0.97 years and the average dialysis period lasted 29.9±1.23 months. For the 15 cases in which we used cuprophane membrane the mean age was 40.2±1.31 years and the average dialysis period lasted 16.2±0.86 months. The calcium level of the dialysate in both groups was 1.5 mmol/l. According to the study protocol, the determined oral calcitriol dose was 0.07 mg/kg and it was administered intermittently. After one month on high dose calcitriol therapy, treatment was continued with a maintenance dose of 0.03 mg/kg for a further six months. As a phosphate binding agent, daily 3 g calcium carbonate was administered. Before starting this treatment protocol, patients went on a 1 mg/day calcitriol therapy, although the mean PTH level was 424.63 pg/ml and the mean serum alkaline phosphatase level was 290.2 U/l. During the pretreatment period, levels of PTH, alkaline phosphatase, ionized calcium, and total calcium remained significantly within normal limits as a result of the new therapy protocol applied. PTH and phosphorus clearance rates were compared in the patient groups in which different dialysis membranes had been used. PTH and phosphorus clearances were 15.2±3 ml/min and 239.1±19.2 ml/min, respectively, in the polysulfone membrane group, and 1.1±0.3 ml/min and 112.8±9.88 ml/min, respectively, in the cuprophane membrane group (p<0.05).     

Management of chronic calcaneal osteomyelitis with pull-through abductor hallucis muscle flap -a report of three cases

Three patients who had chronic osteomyelitis of the calcaneus were treated with radical debridement of all involved soft tissue and bone and obliteration of dead space with a pull-through abductor hallucis brevis muscle flap. Two patients had calcaneal osteomyelitis without soft tissue loss resulting from previous comminuted calcaneal fractures while a third patient had a large soft tissue defect and calcaneal osteomyelitis resulting from a destructive infection. All of the patients had undergone several surgical procedures for treatment of the osteomyelitis with histories ranging 18 months to 30 months. Following treatment with the pull-through muscle flap there has been no recurrence over the longterm (>two years). We believe that radical removal of all contaminated tissue and immediately coverage with a muscle flap provides an effective single stage treatment of chronic calcaneal osteomyelitis.     

Immediate ultrastructural effects of endothelin-1 on rabbit basilar artery

Summary In this study intra-arterial Endothelin-1 was applied to rabbit basilar arteries and morphological findings were compared between two groups who were either perfusion fixed or immersion fixed. We planned to establish the quantitative dimension of the drug-induced morphological alterations, independent of the fixation technique's effect.There was an abundance of collagenous fibres deposited among the smooth muscle cells which was not observed in control arteries and after immersion fixation. These degenerative changes are similar to the finding following subarachnoid haemorrhage. The only fixation-related difference was the fact that lamina elastica interna was not corrugated in the perfusion fixation group.It is concluded that, the observed changes in the connective tissue of the arterial wall alter the passive elastic properties and so affect the degree of the response to the vasoactive messengers.     

The modification of the new type of end-to-side anastomosis between carotid arteries in rats: A technical and Scanning Electron Microscopic study

Summary Modification of a type of end-to-side anastomosis that has been described before is studied. The recipient artery is occluded for only 3–4 minutes to complete the anastomosis by using only the running suture. The anastomotic site was studied by inspection and Scanning Electron Microscope (SEM) at different times after the operation on 30 rats.     

Affective temperaments in clinically-well subjects in Turkey: initial psychometric data on the TEMPS-A

BACKGROUND: This is a first attempt to evaluate the reliability and factor structure replicability of the Temperament Evaluation of Memphis, Pisa, Paris and San Diego Autoquestionnaire (TEMPS-A) in its Turkish Version. The questionnaire is a self-report 110-item measure that postulates five affective temperaments-the depressive, cyclothymic, irritable, hyperthymic, and anxious-which embody both strengths and liabilities along affective lines. METHODS: The questionnaire was administered to 658 clinically-well subjects in a Turkish university circle. We undertook item analysis and test-retest reliability. We then examined internal consistency through factor analysis with PCA rotation. RESULTS: We found good to excellent test-retest reliability (0.73-0.91), and internal consistency (0.77-0.85). We deleted 10 items with factor loading <0.20 for their own subscales, resulting in a questionnaire with 99 items. Despite considerable overlap between depressive and cognitive anxiety traits, a distinct "nervous"-anxious factor emerged as well, and the hypothesized (original English) 5-factor structure of the TEMPS-A was supported. Cut-offs for each temperament were based on z-scores higher than +2S.D. Dominant irritable (3.7%), nervous-anxious (3.7%) and depressive (3.1%) temperaments were the most common in this population, whereas dominant cyclothymic (1.7%) and hyperthymic (1.2%) temperaments were relatively uncommon. These temperaments tended to lose their intensity with age. As expected, women scored significantly higher on the nervous-anxious, and men on the hyperthymic temperaments. LIMITATIONS: The sample was composed of younger subjects with higher education than the general population of Turkey. Although the distribution of the scores for each of the temperaments deviated somewhat from normal curves, for heuristic reasons we did attempt to provide prevalence rates based on z-scores. CONCLUSION: In this preliminary version of the TEMPS-A, we have retained 100 (of the original 110) traits loading >0.20. Some deleted items referred to sleep, others appeared socially desirability traits in the Turkish culture endorsed by many subjects. Nonetheless, item analyses within each factor revealed traits indicative of personal assets (specific to each temperament) along with those which might represent vulnerability to affective illness. This is in line with the hypothesized original theoretical framework of the senior authors. Even in this "first pass," in its Turkish version the TEMPS-A is a reliable and valid instrument. Further refinement of the instrument will require the study of a nationally representative sample in Turkey.