In Vivo Platelet Activation Induced by Bothrops jararaca Venom in Rabbits

Disturbances of platelet morphology, coagulation and fibrinolysis were studied 3, 6, and 24 h following administration of Bothrops jararaca snake venom to rabbits (80 μg/kg, i.v.). The activation of coagulation and fibrinolytic systems was demonstrated by a significant decrease in fibrinogen concentration, and an increase in fibrin(ogen) degradation product concentration, respectively. However, the prothrombin activity remained within normal limits throughout. Significant thrombocytopenia was observed 3 h following venom administration. A decrease in platelet dense body numbers was observed until 24 h. 'Exhausted' platelets and evidence of granular secretion were frequently observed in envenomed rabbits. The open canalicular system was only dilated in extensively degranulated platelets. The mean platelet area and boundary values were not significantly different from control group. Therefore, B. jararaca venom can stimulate platelets in vivo, inducing release of platelet granular content. The etiology of thrombocytopenia in B. jararaca envenoming seems to be a multifactorial process, causing platelet sequestration.     

The ret protooncogene is expressed in normal human parafollicular thyroid-cells

The RET proto-oncogene has been demonstrated to be expressed in medullary thyroid carcinomas and pheochromocytomas, and was mutated in patients with the multiple endocrine neoplasia type 2A (MEN 2A). The results presented herein show its expression in normal human thyroid parafollicular C cells. Since RET is predicted to encode a receptor for a still unknown ligand, these data confirm its involvement in the regulation and growth of these cells.     

Postzygotic instability of the myotonic dystrophy p[AGC]n repeat supported by larger expansions in muscle and reduced amplifications in sperm

We have analysed the [AGC] expansion in leucocytes, muscle and sperm from 17 individuals affected by myotonic dystrophy (DM). Skeletal muscle showed a larger repeat number than leucocytes in the same patient. A similar degree of expansion was detected in differently affected muscles of a single patient. The germline mutation ( 350 repeats) was expanded in somatic cells of the progeny in all patients examined. Our results provide evidence of an early postzygotic instability of the [AGC] repeat in DM.     

Isolation perfusion in extracorporeal circulation with interleukin-2 and lymphokine-activated killer cells in the treatment of in-transit metastases from limb cutaneous melanoma

Background: Therapies of advanced melanoma patients with interleukin-2 (IL-2) and cytotoxic lymphocytes have produced interesting results, but a larger diffusion of these treatments is limited by the severe side effects due to IL-2 systemic infusion. A strictly regional administration of IL-2 and cells by an isolation perfusion (IP) in extracorporeal circulation (ECC) for the treatment of regional melanoma metastases could improve tolerability and efficacy of this specific modality of immunotherapy. Methods: Ten patients were submitted to adoptive immunotherapy with IL-2 and lymphokine-activated killer (LAK) cells by IP in ECC. The schedule of treatment included the first course of a 5-day systemic administration of IL-2 (Proleukin, EuroCetus 9–12 × 10⁶ IU/M²/day continuous infusion); autologous LAK cells were obtained via leukapheresis and after in vitro activation were given (range 8–28 × 10⁹) along with IL-2 (120-2,400 IU/ml of perfusion priming) to the affected limb by IP; IL-2 (9–12×10⁶ IU/m²/day) was also administered by systemic continuous infusion for 5 days starting on the day after IP. Results: All patients concluded the treatment without any major local or systemic toxicities. Clinical responses included one complete and six partial remissions; three patients had stable disease. All patients are alive. Follow-up after IP ranged from 12 to 35 months (median: 22). The analysis of circulating lymphocytes revealed the rapid disappearance of LAK cells, suggesting their extravasation and/or endothelial adhesion in perfused tissues. Conclusions: IP with IL-2 and LAK cells is a new approach for the treatment of in-transit metastases due to cutaneous melanoma. The treatment appears to be feasible and reliable. Further biological and immunological studies should permit amelioration of the present modality of treatment.     

A splenic autograft in posttraumatic splenectomies

BACKGROUND AND AIMS: The authors report their experience regarding the use of autologous splenic transplantation in post-traumatic splenectomy unable to be treated using conservative surgery. After reviewing the international literature on the subject, they report a retrospective survey of cases treated from January 1992 to December 1996. METHODS: Owing to the particular logistic location of the hospital in an area with a high density of industry and at the crossroad of major road and rail routes, a total of 56 patients were admitted to the Emergency Ward suffering from abdominal trauma in 4 years. The patients included in this study could not be treated using conservative surgery: the study group included 15 patients aged between 14 and 76 years old. The surgical technique consisted of the graft of sections of splenic pulp in omental pockets, subsequently marked using metal clips. In order to evaluate splenic immunological function a complete hemochromocytometric examination was performed in each patient at the same time as emergency preoperative tests consisting of peripheral blood strip and pitted cells (PC) assay. This was followed by postoperative evaluations at weekly intervals, including platelet count, Howell-Jolly bodies assay (HJb), immunoglobulin M assay and hepatosplenic scintigraphy using erythrocytes marked with 99m-Technetium pertechnetate (99mTc). RESULTS: An adequate functional recovery of splenic tissue was achieved in all patients with partial recovery of hemocatheretic and immunological function. CONCLUSIONS: The authors' clinical experience confirmed the data inferred from animal experiments: the simplicity of the preparation technique and the autologous transplantation of splenic pulp in the absence of major complications confirms the possibility of applying this method in all splenectomies performed under emergency conditions.     

Preparation and local anaesthetic activity of benzotriazinone and benzoyltriazole derivatives

Two sets of benzotriazinone and benzoyltriazole derivatives were prepared and tested for local anaesthetic activity in comparison with lidocaine. Several of the prepared compounds exhibited a fairly good activity comparable or superior to that of lidocaine. The presence of a benzotriazinone or a benzoyltriazole moiety as an aromatic system was quite profitable for both the intensity and duration of activity. The acute toxicity in mice of the four most potent compounds of the series was also assessed. Compound 1b, which has an anaesthetic activity comparable to that of lidocaine, was also characterized by a more favourable therapeutic index. All compounds were tested in vitro to evaluate their negative chronotropic action in isolated rat right atria.     

Estradiol and estrone plasma levels during application of three strengths of a 7-day estradiol transdermal patch.

BACKGROUND: A new estradiol transdermal patch was developed for a once weekly application, with the aim to achieve an optimum practicability and to improve long-term compliance with estrogen replacement therapy. The pharmacokinetics of estradiol (CAS 50-28-2) and of estrone (CAS 53-16-7) during a 7-day application of the new patch is reported in this publication. METHODS: Unconjugated estradiol and estrone were assayed in plasma in a three-way crossover study on 18 postmenopausal women during and after a 7-day application of 3 strengths of the new patch, with daily release rates of 25, 50 and 75 micrograms of estradiol. RESULTS: During the 7-day application of the transdermal patches the concentration in plasma of unconjugated estradiol increased from less than 5 pg/ml, typical of postmenopause, to average concentrations of 26, 49 and 66 pg/ml under the patches with the release rates of 25, 50 and 75 micrograms/day of estradiol, respectively. The increases were linearly related and proportional to the strength of the patches. Upon removal of the patches, the estradiol concentrations returned to the basal postmenopausal values in 8-24 h. Retarded with regard to estradiol, there was also an increase of unconjugated estrone, from basal concentrations of 24 pg/ml to average concentrations of 39, 54 and 62 pg/ml, respectively. Estrone returned to its basal concentrations 24-48 h after removal of the patches. The estradiol/estrone ratio from the low pre-treatment values of 0.15-0.21 typical of postmenopause increased to average values of 0.51, 0.92 and respectively 1.09 during the application of the patches with the three strengths. The ratios are in the range of those of unconjugated hormones during the fertile age of women. The patches were well tolerated by the skin, with rare mild and transient reactions that disappeared spontaneously and did not cause interruption of treatment. Also the systemic tolerability was good, with occasional mild or moderate side effects typical of estradiol found especially under the application of the two higher strengths, i.e. with release of 50 and 75 micrograms/day of estradiol. CONCLUSIONS: The effective pharmacokinetic performance over the 7-day application, combined with the good general and local tolerability and the need to apply the patches only once weekly confer to the new patches a favorable practicability for the long-term estrogen replacement therapy needed to control the most severe postmenopausal disorders.     

On-line urea kinetics in haemodiafiltration

BACKGROUND.: Calculation of Kt/V and assessment of nutrition have so farbeen dependent upon off-line urea measurements of blood or dialysatesamples. Here we describe a biosensor for on-line urea measurementduring haemodiafiltration. METHODS.: The biosensor consisted of a cartridge containing covalentlylinked urease placed between two conductivity cells. The biosensorwas placed on the outlet line of a haemofilter in series witha dialyser in order to obtain an aliquot of plasma ultrafiltratefor on-line measurement of urea. RESULTS.: Urea nitrogen concentrations were highly correlated to the difference() in conductivity measured by the two conductivity cells bothin aqueous solutions (in-vitro studies, y=–6.676+32.12x,R²=0.998, P<0.0001) and in ultrafiltrates (ex-vivo studies,y=–6.7+32.01x, R²=0.98, P<0.00001). conductivity washighly reproducible (% variation: 0.8–5.3%) and stable(maximal % variation at 150 mg/dl after 180 min: 0.9±0.3vs initial values). The intradialytic plasma water urea profilewas obtained in 10 haemodialysis patients. To study recirculation,the plasma water urea profile was analysed before and 3 minafter stopping the dialysate flow. The pre- and post-stoppedflow ratio (1.21±0.1, mean±1 SD) was superimposableto conventional blood sampling data (opposite arm venous/arterial:1.22±0.11) and allowed correction for recirculation.A novel approach to urea kinetic modelling was described andused to reliably project end-dialysis and post-dialysis reboundurea concentration as early as 90 min. Projected (29.2±10.4g) or measured (29.8±10.5 g) net urea removal was highlycorrelated with the amount of urea collected in the total spentdialysate (29.7±10.6 g) (R²=0.99, R²=0.97 respectively). CONCLUSIONS.: These results indicate that on-line, real-time analysis of ureakinetics may provide information on delivery of adequate dialysisin high-efficiency techniques.     

Intrafamilial phenotype variation in Friedreich's disease: possible exceptions to diagnostic criteria

Summary Three families are described which include members with typical Friedreich's disease (FD) and others who are ataxic but do not satisfy all the diagnostic criteria for that disease. In family A two patients have an early-onset, rapidly progressive FD, while two others have a late-onset, more benign form. In families B and C one member has typical FD, and another has a similar ataxic syndrome, except for preservation of knee jerks. Laboratory evaluation is consistent with the diagnosis of FD in all cases. FD diagnosis appears justified in secondary cases with late onset or preserved tendon reflexes, provided that the index case fulfils all diagnostic criteria. Whether the diagnosis of FD is tenable in sporadic atypical cases remains to be seen. Echocardiographic and neurophysiological examination may be valuable in classifying such cases.