Clinical comparison of bioabsorbable barriers with non-resorbable barriers in guided tissue regeneration in the treatment of human intrabony defects

The purpose of the study was to compare the effects of guided tissue regeneration (GTR) with expanded polytetrafluoroethylene (ePTFE) non-resorbable barriers and polylactic acid bioabsorbable barriers in humans with intrabony defects due to periodontitis. Ten patients presented with 2 intrabony defects each. Mucoperiosteal flaps were performed. One of the defects was randomly assigned for placement of the ePTFE barrier over the roots and alveolar bone and the other defect with placement of the polylactic acid barrier. A minimum of 9 months after barrier placement, surgical reentry was performed. The data were evaluated by the Wilcoxon matched-pairs signed-ranks test and the Fisher exact test. Treatment with both types of barriers produced significant changes from baseline for all parameters, except in the ePTFE group for the amount of bony crest resorption (P = 0.055) and in the polylactic acid group for increased recession (P = 0.109). The results showed no significant differences between the barriers for any parameters: probing depth reduction (polylactic acid 2.60 +/- 1.90, ePTFE 2.80 +/- 1.40; P = 1.000); attachment gain (polylactic acid 1.40 +/- 1.43, ePTFE 1.90 +/- 1.29; P = 0.336); increased recession (polylactic acid 0.80 +/- 1.40, ePTFE 1.10 +/- 0.99; P = 0.531); amount of vertical bone fill (polylactic acid 1.60 +/- 1.84, ePTFE 2.00 +/- 2.49; P = 0.984); bony crest resorption (polylactic acid -1.30 +/- 1.06, ePTFE -1.30 +/- 1.63; P = 1.000); depth of bony defect reduction (polylactic acid 2.90 +/- 1.20, ePTFE 3.30 +/- 1.70; P = 0.750); width of bony defect reduction (polylactic acid 2.20 +/- 1.23, ePTFE 2.20 +/- 1.23; P = 0.875); or volumetric changes (polylactic acid 33.50 +/- 19.70 microl, ePTFE 34.00 +/- 18.40 microl; P = 0.750).     

Periodontal repair in intrabony defects treated with a calcium carbonate implant and guided tissue regeneration

OBJECTIVE: To determine mortality and factors that might predict outcome in severe community-acquired pneumococcal pneumonia treated by a standard protocol. DESIGN: Prospective, non-concurrent study. SETTING: Respiratory intensive care unit (ICU) in a teaching hospital. PATIENTS: 63 patients who were diagnosed by positive blood culture or Gram stain and culture of sputum or tracheal aspirate were included. MEASUREMENTS AND RESULTS: Clinical features, severity scores including Acute Physiology and Chronic Health Evaluation (APACHE) II, organ failure and lung injury scores, and the clinical course in the ICU were documented; 79% of patients required mechanical ventilation. Bacteraemia was present in 34 patients (54%); there were no distinguishing clinical features between bacteraemic and non-bacteraemic cases. The overall mortality was 21%, with only 5 deaths (15% mortality) in the bacteraemic group. Shock and a very low serum albumin (< 26 g/l) were the only clinical features that differentiated survivors from non-survivors; lung injury, APACHE II and multiple organ failure scores were all predictive of outcome. The positive predictive value and specificity in predicting death in individuals for the modified British Thoracic Society rule 1 were 26 and 64%; APACHE II > 2057 and 88%; > 2 organ failure 64 and 92%; and lung injury > 233 and 73%, respectively. CONCLUSIONS: These results suggest that even in bacteraemic cases mortality should be below 25% with intensive care management and that conventional scoring systems, while predictive of group mortality, are unreliable in individuals.     

Comparison of 2 regenerative procedures--guided tissue regeneration and demineralized freeze-dried bone allograft--in the treatment of intrabony defects: a clinical and radiographic study

The purpose of this study was to compare clinically and radiographically the effectiveness of guided tissue regeneration (GTR), using a bioabsorbable polylactic acid softened with citric acid ester barrier and commercially available demineralized freeze-dried bone allograft (DFDBA) in the treatment of 2- and 3-wall intrabony defects. Twelve patients each with one treated defect comprised each group. Conservative treatment was completed 2 to 4 months prior to surgery. Clinical measurements, plaque index, gingival index, probing depths (PD), clinical attachment levels (CAL) and recession (REC), were comparable in both groups at baseline. They were repeated at 12 months. Surgical measurements were also comparable at baseline in both groups. In the GTR group, at baseline the mean distance between the cemento-enamel junction (CEJ) and base of the defect was 12.3 +/- 2.9 mm and in the DFDBA group 11.3 +/- 1.8 mm. The defect depth was 6.3 +/- 2.0 mm and 5.4 +/- 1.3 mm, respectively. Radiographs were taken at baseline and 12 months later and compared using non-standardized digital subtraction radiography. In the GTR group, mean PD decreased from 7.9 +/- 2.5 mm to 3.5 +/- 1.4 mm and mean CAL from 10.8 +/- 2.8 mm to 7.0 +/- 1.6 mm, the differences being statistically significant (P = 0.002), while REC increased from 2.9 +/- 1.2 mm to 3.5 +/- 1.1 mm. In the DFDBA group, mean PD decreased from 7.1 +/- 1.1 mm to 3.5 +/- 1.1 mm and mean CAL from 9.8 +/- 1.5 mm to 6.6 +/- 1.7 mm (P = 0.002), while REC increased from 2.8 +/- 1.0 mm to 3.1 +/- 1.2 mm. No significant differences were found when the clinical results of the 2 groups were compared. Radiographic differences between the baseline and reconstructed images 12 months later were observed in both groups. Mean crestal bone resorption was 15.3 +/- 22.5% in the GTR group and 10.4 +/- 31.8% in the DFDBA group, and mean improvement in the distance between the CEJ and the base of the defect was 22.8 +/- 18.1% in the GTR group and 15.3 +/- 13.6% in the DFDBA group. However, the mean improvement in the intrabony depth was larger in the GTR group (71.9 +/- 29.1%) than in the DFDBA group (35.4 +/- 21.6%) (P = 0.007). In conclusion, within the limits of this study, both regenerative procedures were beneficial in treating intrabony defects. No statistical significant differences were observed between the 2 groups, with the exception of radiographic defect resolution which was significantly greater in the GTR group.     

Periodontal repair in intrabony defects treated with a calcium sulfate implant and calcium sulfate barrier

THIS RANDOMIZED, CONTROLLED, CLINICAL STUDY was designed to evaluate outcome following surgical implantation of an allogeneic, freeze-dried, demineralized bone matrix-calcium sulfate (DBM+CS) composite with a CS barrier in intrabony periodontal defects. Twenty-six patients contributing 26 deep intrabony defects completed the study. Thirteen patients received the DBM+CS implant. Thirteen patients received gingival flap surgery alone (GFS; control). Clinical outcome was assessed at 6 and 12 months postsurgery. At 12 months postsurgery, probing depth (PD) reduction (mean +/-SD) for the DBM+CS and GFS group was to 4.3+/-0.5 and 3.0+/-1.3 mm; clinical attachment gain was to 2.9+/-0.8 and 1.7+/-1.5 mm; and probing bone level gain was to 2.9+/-1.4 and 1.2+/-1.2 mm, respectively. There were no apparent differences between evaluations at 6 and 12 months postsurgery. Clinical improvements were significantly different from presurgery for both groups at both observation intervals (P < 0.01). There were no significant differences between groups in PD reduction and clinical attachment gain. Probing bone level gain was significantly greater in the DBM+CS group compared to controls (P < 0.05). In summary, surgical implantation of DBM+CS with a CS barrier resulted in reduced PD and improved attachment levels comparable to that achieved by gingival flap surgery alone. However, gain in probing bone levels in deep intrabony periodontal pockets assessed by clinical parameters was greater than that observed by gingival flap surgery alone. These changes were noted at both 6 and 12 months after surgery. This regenerative technique needs further biologic evaluation before being generally accepted.     

Guided tissue regeneration for the treatment of intraosseous defects using a biabsorbable membrane. A controlled clinical study

The aim of this controlled, clinical study was to evaluate guided tissue regeneration using a bioabsorbable membrane in periodontal intraosseous defects. Forty patients, each contributing one defect > or =4 mm in depth participated. The control group (18 individuals) received conventional flap therapy, while the test group (22 individuals) was treated using the bioabsorbable membrane, Guidor. Clinical assessments were made by one examiner, blinded with respect to treatment group, at baseline, 6 and 12 months following surgery. Baseline probing pocket depths of 7.7+/-1.4 mm in the membrane group and 7.6+/-1.9 mm in the control group were measured. Twelve month results showed a significant clinical attachment level gain in both control (1.1+/-1.8 mm), and membrane group (1.3+/-2.1 mm). Probing pocket depth reduction of 2.6+/-1.9 mm and 2.7+/-1.9 mm was observed in the respective groups. Bone sounding showed a non-significant gain of 0.4+/-1.8 mm and 0.6+/-1.4 mm at membrane and control sites, respectively. Radiographic evaluation confirmed these results. There were no significant differences found between treatment groups for any of the tested variables. Smoking had a negative effect on healing in both groups. In conclusion, clinical and radiographic results indicate that guided tissue regeneration using a bioabsorbable membrane at intraosseous defects did not predictably achieve greater clinical attachment level gain nor bone gain when compared to conventional flap therapy.     

Generalizability of the added benefits of guided tissue regeneration in the treatment of deep intrabony defects. Evaluation in a multi-center randomized controlled clinical trial

BACKGROUND: Several studies have shown that GTR therapy of intrabony defects results in significantly better outcomes than access flap alone. Most of the available data, however, have been produced in highly controlled research environments by a small group of investigators. Generalizability of results to different clinicians and different subject populations has not been evaluated so far. METHODS: This parallel group study involved 143 patients recruited in a practice-based research network of 11 offices in 7 countries. It was designed to evaluate: 1) the applicability of the documented added benefits of GTR in the treatment of intrabony defects to different populations, and 2) the generalizability of the expected results to different clinicians. GTR was compared to access flap alone. Defects, one in each patient, were accessed with a previously described papilla preservation flap in both the test and control group. In addition, GTR sites received application of a bioabsorbable poly-D,L-lactide-co-glycolide membrane. A stringent plaque control regimen was enforced in all patients during the 1-year observation period. Outcomes included gains in clinical attachment (CAL) and reductions in probing depth. RESULTS: Observed gains in CAL were 2.18 +/- 1.46 mm for access flap and 3.04 +/- 1.64 mm for the GTR-treated group. The treatment-associated difference was statistically significant (P = 0.03) after correcting for both center effect and defect anatomy. Among the various centers, a 1.73 mm difference in CAL gain was observed. This is a clinically relevant amount, which underlines the significance of center variability in the outcome of periodontal surgical procedures. A frequency distribution analysis of the obtained CAL gains indicated that GTR treatment of deep intrabony defects decreased, with respect to the access flap control, the probability of obtaining only a modest attachment gain at 1 year. Conversely, CAL gains of 4 mm or more were observed in more than 40% of GTR-treated defects and in less than 20% of the controls (P < 0.0001). CONCLUSIONS: These data indicate that GTR therapy of deep intrabony defects performed by different clinicians on various patient populations resulted in both greater amounts and improved predictability of CAL gains than access flap alone.     

A clinical evaluation of guided tissue regeneration with a bioabsorbable matrix membrane combined with an allograft bone graft. A series of case reports

THE PURPOSE OF THIS STUDY was to evaluate the clinical effectiveness of a surgical technique in treating periodontal defects. The technique combined tetracycline treatment of a root planed root, grafting of the osseous defect with a demineralized freeze-dried bone allograft combined with tetracycline and the placement of a bioabsorbable matrix membrane, made of polylactic acid softened with citric acid ester. Thirty defects were treated in 27 patients. Statistically significant changes, as a result of the surgical procedure, were observed in marginal recession (mean: 0.5 mm), probing depth reductions (mean: 5.7 mm), and attachment level gain (mean: 5.2 mm). No statistically significant difference existed between the results in the furcation and non-furcation groups. The defects with probing depths > or = 10 mm had a greater mean probing depth reduction (7.4 mm) and mean attachment level improvement (7.2 mm) than the defects with < 10 mm probing depths (probing depth reduction 4.5 mm and attachment level gain 3.9 mm). The proposed surgical procedure seemed to be an effective method to treat periodontal defects.     

Guided bone regeneration around dental implants in the atrophic alveolar ridge using a bioresorbable barrier. An experimental study in the monkey

The aim of this study was to evaluate guided bone regeneration (GBR) around dental implants placed in atrophic alveolar ridges using an experimental, nonporous bioresorbable barrier. In 8 Rhesus monkeys, the maxillary canines and lateral incisors were extracted bilaterally and the remaining alveoli were reduced to create atrophic ridges. After a healing period of 3 months, soft tissue expansion was performed using a subperiosteal tissue expander. After 1 month of tissue expansion, and IMZ implant was placed in the atrophic ridge on each side in such a way that its coronal 4 mm to 5 mm remained circumferentially exposed above the bone level. The test implants were covered with a bioresorbable barrier made of poly (D,L-lactid-co-trimethylencarbonate) in a 70/30 ratio, whereas the control implants were covered with a nonresorbable expanded polytetrafluoroethylene (e-PTFE) barrier. The e-PTFE barriers were stabilized with titanium minipins while the bioresorbable barriers were analogously fixed using bioresorbable minipins made of poly (L-lactid-co-D,L-lactid) 70/30. Clinical healing progressed uneventfully in both groups and no soft tissue dehiscences occurred. Histometric and histomorphometric analyses were performed 5 months post surgery. Both test and control implants exhibited direct bone-to-implant contact to variable extents. The mean direct mineralized bone-to-implant contact length fraction was 32% of the total implant length in the test sites and 58% in the control sites. Control sites exhibited significantly greater bone fill compared to the experimental sites (P < 0.001). Histologic observations of test specimens demonstrated a moderate inflammatory reaction related to the degradation and resorption products of the barrier. In conclusion, the nonresorbable e-PTFE GBR barrier was found to be superior to the bioresorbable barriers tested in the present investigation.     

Gingival recession and exposure of barrier membrane: effect on guided tissue regeneration of Class II furcation defects

The purpose of the present study was to evaluate the effect of barrier membrane exposure on the success of guided tissue regeneration in Class II furcation defects. Twenty-six subjects with mandibular Class II furcation defects received initial periodontal therapy followed by guided tissue regeneration surgery. The membrane was placed and the flaps were repositioned so that the membrane was totally submerged. Membranes were removed 4 to 6 weeks later, at which time the extent of their exposure was recorded. An overall improvement in all clinical parameters was observed for all subjects 1 year after surgery. Half of the patients had experienced no membrane exposure, while the other 13 subjects had experienced mild to pronounced exposure; both groups showed similar improvement in all clinical and surgical parameters. In light of the comparable results obtained in exposed sites, and the anatomic difficulties sometimes encountered in covering a membrane completely, in some of these cases the membrane may be left only partially submerged. This approach will allow for tighter occlusal "seal" of the tooth-membrane interface and preservation of the keratinized gingiva.     

A prospective and consecutive study of surgically treated lumbar spinal stenosis. Part I: Clinical features related to radiographic findings

STUDY DESIGN: A prospective and consecutive study of surgical results obtained during serial follow-up investigations in patients who underwent surgery for central lumbar spinal stenosis. OBJECTIVES: To evaluate the result after surgical decompression for lumbar spinal stenosis, at regular intervals after surgery, and to correlate these results with values for preoperative parameters; special interest was focused on the results in relation to the degree of constriction of the spinal canal. SUMMARY OF BACKGROUND DATA: The outcome after surgery for spinal stenosis is debatable; long-term follow-up investigations have indicated deterioration with passing time. Results of studies in nonsurgical patients have demonstrated that the symptoms do not progress with time. Results of a meta-analysis of the literature on surgical results have demonstrated a wide variation of outcomes. MATERIAL AND METHODS: In a prospective study, 105 consecutive patients who underwent surgical decompression (laminectomy with facet-preserving technique, but no fusion) were evaluated at follow-up examinations 4 months and 1, 2, and 5 years after surgery. At the follow-up examinations, the patient's opinion on the surgical result was registered, using a four-grade scale. The occurrence of pain at rest and at night was registered, as well as the patient's walking ability. Statistical analysis was performed, relating the surgical results to patient age, gender, preoperative duration of symptoms and radiographically observed constriction as described in Part I of this study. The radiologist was blinded to patient outcome. Logistic regression analysis was performed. RESULTS: During the follow-up period, 19 patients underwent reoperation, consisting of fusion to treat lumbar pain (n = 4), repeat decompression because of progressive stenosis (n = 13), and repairs in response to surgical complications (n = 2). Follow-up results: The result, related to the recurrence of leg symptoms, deteriorated with passing time. Excellent results were reported by 63% to 67% at 4-month and 2-year follow-ups compared with 52% at the 5-year follow-up. There was a correlation between the constriction of the spinal canal and the outcome at all intervals. Patients with an anteroposterior diameter of 6 mm or less at the narrowest site had significantly better results. The logistic regression analysis demonstrated a significant correlation between a severe reduction of the anteroposterior diameter and excellent results and a tendency toward better results in patients with a shorter preoperative duration of symptoms. Improvement of walking ability was also associated with a pronounced constriction of the spinal canal. CONCLUSION: The results after surgical decompression in patients with central spinal stenosis deteriorated with time. There was a significant correlation between good result and pronounced constriction of the spinal canal. Patients with a preoperative duration of symptoms of less than 4 years and patients with no preoperative back pain tended to have better surgical outcomes. The reoperation rate was 18% within 5 years. When surgery for spinal stenosis is contemplated, these prognostic factors should be taken into consideration: The "ideal patient" has a pronounced constriction of the spinal canal, insignificant lower back pain, no concomitant disease affecting walking ability, and a symptom duration of less than 4 years.     

Biodegradation and biocompatibility of a guided tissue regeneration barrier membrane formed from a liquid polymer material

Biodegradable barrier films were made by coagulating a solution of poly(DL-lactide) in N-methyl-2-pyrrolidone on porous polyethylene pads wetted with saline solution. The semisolid films were cut into 10 x 10 mm barriers and implanted subcutaneously in rabbits. At monthly intervals, the polymer implant sites were compared histologically to those implanted with USP negative control plastic. The polymer films were retrieved from the surrounding tissue, dried, weighed, and the changes in molecular weight determined using gel permeation chromatography. The molecular weight of the polymer decreased at a relatively constant rate over 5 months; however, no significant mass loss occurred until 5 months postimplantation. Also, no distinct histological differences were noted between the polymer barrier and the control plastic sites until 6 months when histiocytes and multinucleated giant cells showed a modest increase around fragmented polymer films. Similar barrier films also were fitted over naturally occurring buccal dehiscence defects in beagle dogs and the tissue sites compared histologically at 6 months to sham-operated control sites. New bone and dense connective tissues closely approximated segments of the remaining polymer and demonstrated the biocompatibility of the biodegradable films. Histomorphometric analyses of treated sites compared to sham controls showed that the polymer barrier is effective in promoting bone and cementum regeneration in periodontal defects in dogs.     

Guided tissue regeneration using bioresorbable membranes: what is the limit in the treatment of combined periapical and marginal lesions?

The maintenance of single teeth may often be of crucial importance for the prognosis of the total dentition. In such cases, as when a single tooth supports a fixed partial denture, a special effort should be made to maintain that tooth. This study reports the treatment of six such terminal cases. The results of a combination of local and systemic antibiotics and the use of guided tissue regeneration with resorbable membranes and grafting material is demonstrated. After defect debridement and root planing, the defects were filled with Biostite (Coletica), and Paroguide (Coletica) membranes were placed. The results at reentry demonstrated the efficacy of these treatments, and all six treatments were considered successful. The influence of the individual components used in treatment is discussed.     

Volumetric changes following barrier regeneration procedures for the surgical management of grade II molar furcation defects in baboons: II. Bone, cementum, epithelium, and connective tissue

Written guidelines based on current research on infant pain assessment and management were developed by an interdisciplinary team in a neonatal intensive care unit of a regional medical center. Charts for infants who had undergone abdominal surgery were reviewed to compare patient outcomes before and after use of this pain management protocol. With the standardization of pain management strategies, the following improvements were noted: decreased length of time to extubation, decreased length of stay, better fluid management, and reduced side effects of narcotics. Additional benefits included improved pain management documentation, decreased cost, and decreased nursing time.     

Long-term results of Watson-Jones tenodesis of the ankle. Clinical and radiographic findings after ten to eighteen years of follow-up

Thirty-seven chronically unstable ankles in thirty-six patients were operated on with use of a Watson-Jones tenodesis. Thirty-four ankles (thirty-three patients) were followed for a mean duration of thirteen years and eight months (range, ten to eighteen years) after the operation. There were nine male and twenty-four female patients. The mean age of the patients was thirty-one years (range, fourteen to fifty-seven years) at the time of the operation and forty-four years (range, twenty-eight to seventy years) at the time of the latest follow-up. At the time of the most recent follow-up evaluation, twenty-seven patients (twenty-eight ankles) were examined directly by one of us and twenty-five patients (twenty-six ankles) also were evaluated radiographically. The other six patients were interviewed, with use of a questionnaire, by telephone. Of the thirty-four ankles, nineteen had an excellent result (grade 1), eleven had a good result (grade 2), three had a fair result (grade 3), and one had a poor result (grade 4) according to the rating system of Good et al. The mean score (and standard deviation) on the ankle-hindfoot scale of the American Orthopaedic Foot and Ankle Society for the twenty-eight ankles that were examined directly by one of us was 90 +/- 9.3 points (range, 68 to 100 points). Progression of an exostosis at the edge of the joint was detected in eighteen (69 percent) of the twenty-six ankles that were examined radiographically, but narrowing of the joint space was not seen in any ankle. No relationship was detected between the clinical results and radiographic osteoarthrotic changes or the duration of follow-up. The results did not deteriorate over the long term.     

Clinical and radiographic findings that lead to intervention in diabetic patients with foot ulcers. A nationwide survey of primary care physicians

OBJECTIVE: To determine which elements of clinical history, physical examination, and diagnostic tests are important to primary care physicians in their management of foot ulcers in diabetic patients. RESEARCH DESIGN AND METHODS: We conducted a national mail survey of 600 primary care physicians to determine which patient characteristics and diagnostic test results were important in their decisions to seek radiographic studies, surgical referrals, and hospitalization for diabetic patients with foot ulcers. RESULTS: The case characteristics most likely to influence physicians to order advanced diagnostic or therapeutic interventions are the presence of osteomyelitis on plain radiographs, the failure of the ulcer to improve with conservative therapy, and the presence of visible bone, crepitus, or necrosis within the ulcer (P < 0.001). Information from the initial clinical history was less likely to influence physicians to order advanced diagnostic or therapeutic interventions (P < 0.001) than was information from the physical examination. CONCLUSIONS: We conclude that 1) the patient's history is relatively unimportant to primary care physicians in their management of diabetic foot ulcers; 2) the failure of conservative management is a major reason that primary care physicians order surgical referral, hospitalization, or radiographic testing for diabetic patients with foot ulcers; and 3) primary care physicians rely heavily on plain X ray of the foot, a test with poor sensitivity and specificity, in deciding whether to order further interventions for their diabetic patients with foot ulcers.     

Treatment of peri-implantitis using guided bone regeneration and bone grafts, alone or in combination, in beagle dogs. Part 1: Clinical findings and histologic observations

The purpose of this study was to evaluate and compare the treatment of ligature-induced peri-implantitis using guided bone regeneration and two bone grafts alone and in combination. Mandibular premolars and first molars were extracted from four beagle dogs and after 3 months of healing, three Br?nemark implants were placed on each side of the mandibles. Following abutment connection 3 months later, experimental peri-implantitis was induced by tying plaque-retentive ligatures around all abutments. Ligatures and abutments were removed after 3 months, and bony defects measured and treated with either: (1) debridement only; (2) debridement plus resorbable hydroxyapatite; (3) debridement plus canine freeze-dried demineralized bone; (4) debridement plus guided bone regeneration; (5) debridement plus resorbable hydroxyapatite and guided bone regeneration; or (6) debridement plus canine freeze-dried demineralized bone and guided bone regeneration. Pretreatment and 4-month-posttreatment comparison revealed a significant but variable degree of clinically appreciable hard tissue fill with all treatment procedures. Guided bone regeneration procedures resulted in the greatest fill, followed by bone grafts alone and flap debridement. There was no significant difference between guided bone regeneration and both guided bone regeneration/graft combinations; therefore, guided bone regeneration procedures appear to be a predictable treatment for plaque-induced peri-implant defects.     

X-linked recessive spondyloepiphyseal dysplasia tarda. Clinical and radiographic evolution in a 6-generation kindred and review of the literature

Numerous studies have consistently shown that agonist stimulation of adenosine A1 receptors results in a significant reduction of morbidity and mortality associated with global and focal brain ischemia in animals. Based on these observations, several authors have suggested utilization of adenosine A1 receptors as targets for the development of clinically viable drugs against ischemic brain disorders. Recent advent of adenosine A1 receptor agonists characterized by lowered cardiovascular effects added additional strength to this argument. On the other hand, although cardioprotective, adenosine A3 receptor agonists proved severely cerebrodestructive when administered prior to global ischemia in gerbils. Moreover, stimulation of adenosine A3 receptors appears to reduce the efficacy of some of the neuroprotective actions mediated by adenosine A receptors. The review discusses the possible role of adenosine receptor subtypes (A1, A2, and A3) in the context of their involvement in the pathology of cerebral ischemia, and analyzes putative strategies for the development of clinically useful strategies based on adenosine and its receptors. It also stresses the need for further experimental studies before definitive conclusions on the usefulness of the adenosine concept in the treatment of brain ischemia can be made.     

Cardiovascular changes in a group of patients with heredoataxia. Clinical, electrocardiographic and echocardiographic findings

INTRODUCTION: Heredoataxias form a group of degenerative diseases of the nervous system, which are progressive and hand sound in particular families. MATERIAL AND METHODS: Between August 1994 and September 1995. 14 patients diagnosed as having heredoataxia were studied after admission to our hospital. Eight of these had Friedrich's ataxia (group A) and 6 had other types of ataxia (group B). A standard set of investigations were done, including clinical examination, laboratory tests (such as glycaemia and a lipidogram) to evaluate coronary risk factors. A 12 lead electrocardiogram and bidimensional and m mode echocardiogram were also done to detect disorders of conduction, changes in morphology and cardiac function, together with functional cardiovascular and neurological scales. The patients studied were between 14 and 41 years of age. RESULTS: The most frequent cardiovascular symptom was dyspnoea of effort. Changes on the electrocardiogram were seen in 92% of the patients, mainly from Group A (100%) and were due to alterations of ventricular repolarization and non-specific alterations of conduction and of rhythm. Echocardiogram changes were found in 42.8% of the patients, most frequently due to an increase in the myocardial mass of the left ventricle. CONCLUSIONS: Close correlation between age of onset and duration of the illness, and functional cardiovascular impairment was only seen in patients of Group A, in whom there was an earlier onset of the condition.     

Benign hyperplasia of ectopic prostatic tissue. The computed tomographic and magnetic resonance findings in a patient with 2 locations

An open randomized controlled clinical trial was conducted to compare the reactogenicity of a recombinant hepatitis B vaccine (Engerix-B) when injected with the Bioject device (a pneumatically powered drug delivery system using disposable syringes) or with conventional syringe and needle, according to a 0.1 and 6 month vaccination schedule. Ninety-seven healthy young adults were enrolled in this study. Participants were asked to record local and general solicited symptoms and signs after each vaccination and to report each unsolicited symptom and sign that occurred during the study. The use of the jet-gun induced a statistically significant higher incidence of local symptoms and signs (solicited and unsolicited) than the use of syringe and needle.