Allergen immunotherapy: an effective immune-modifier

Allergen-specific immunotherapy (IT) consists in administering gradually increasing doses of an allergen extract to sensitive patients. This practice results in ameliorating symptoms associated with the subsequent exposure to the causative allergen. Presently, the lack of therapies which affect the pathogenesis of the disease make IT the only treatment that may improve the natural course of allergic diseases.

Somatostatin and cimetidine in the control of acute upper gastrointestinal bleeding. A controlled multicenter study

Acute upper gastrointestinal bleeding remains a difficult emergency problem, and, despite recent pharmacological advances, the choice and results of medical treatment are the subject of debate. To determine the effectiveness of two potent inhibitors of gastric acid secretion, somatostatin and cimetidine, in the control of upper gastrointestinal bleeding of non-variceal origin, we initiated a multicentric, randomized, prospective therapeutic trial in 56 patients presenting with acute hemorrhage due to gastric and duodenal ulcers and erosions defined by uniform and precise criteria. The two drugs were administered i.v. for 48 hours at a dose of 250 mcg/h (somatostatin) and 1,600 mg/24 h (cimetidine). Vital signs, laboratory values, and gastric aspirate were checked frequently in accordance with a strict schedule; the number of blood transfusions was also noted. Endoscopy for the assessment of bleeding before admission to the trial and the end of treatment was performed in every patient. Bleeding stopped in 28 of the 30 (93.3%) patients treated with somatostatin, and in 16 of the 26 (61.5%) of those receiving cimetidine (p less than 0.01). The blood requirement of the patients treated with somatostatin and cimetidine was, on average, 1.10 +/- 1.16 and 2.46 +/- 4.03 units per patient, respectively (p less than 0.05). Somatostatin was also significantly superior - in the patients in whom the treatments were successful - with respect to the time taken to achieve this result. In conclusion, our results, together with those already published, point to a definite therapeutic effectiveness of somatostatin in upper gastrointestinal bleeding as here defined, and would appear to justify a more extensive clinical use under controlled conditions.

Experimental chronic epilepsy in rats: a screening method for antiepileptic drugs

Rats were rendered epileptic by subpial injection of an FeCl3 solution. Epileptiform discharges, recorded by chronically implanted extradural electrodes, were evident within 48 h of surgery and persisted for more than 6 months. It is demonstrated that this model is useful for studying new antiepileptic agents since a series of clinically effective drugs (diazepam, clonazepam, Na phenobarbital, primidone, carbamezepine, ethosuximide, diphenylhydantoin, Na valproate, GABOB) show an activity which is does-dependent and within a range satisfactorily related to human dosages.

Influence of age upon the cerebral metabolic changes induced by acute hypoxia on the synaptosomes from dog brain

The synaptosomal fraction obtained from the motor area of the cerebral cortex of normocapnic, normoxic or hypoxic "young adult," "mature" and "senescent" beagle dogs is incubated and analyzed for : ATP, ADP, AMP, creatine phosphate, pyruvate and lactate. The data are compared with those obtained from the whole controlateral cortical motor area, by the surface freezing technique. After hypoxic hypoxia /15 min; PaO2 = 17-19 mm Hg), the metabolite contents and ratios are differently affected by ageing when the evaluations are performed in the incubated synaptosomal preparation or in the controlateral whole cerebral tissue. In fact, ageing does not affect so much the cerebral changes that occur in the overall energetic state during the hypoxic assault in vivo, but rather those that the synaptosomes remember the tend to reverse during the subsequent incubation in vitro. The protective action of several drugs on the synaptosomal phosphorylation state is tested. Phenobarbital shows a quite broad, age-independent spectrum of action. (-)Eburnamonine and dihydroergocristine exhibits a more limited, age-dependent effectiveness, but are devoid of anesthetic action. Papaverine proves unable to affect the tested biochemical parameters.

UDP-glucose effect on phrenic diaphragm preparation of the rat

The effects of uridine-5'-diphosphoglucose (UDPG) on the contractile response of the phrenic nerve-diaphragm preparation and on carbohydrate metabolism in the diaphragmatic muscle were studied in the rat. In the preparations obtained form rats, the contracturant action of UDPG, previously observed in guinea-pig preparations, was thus confirmed. This action was compared with those of uridine, UMP and UDP. Uridine alone was ineffective, while the higher concentration of both UMP and UDP induced a contracture comparable with that shown for the lower concentration of UDPG. This indicates that the action of UDPG is partially related at least to one phosphate-group into its molecular structure. In addition, several substrates and intermediates related to carbohydrate metabolism (glycogen, glucose, glucose-6-phosphate) were measured in the diaphragm, their concentrations proving unaffected by UDPG perfusion.

Cerebral enzymatic activities during chronic hyperammonemia and treatment with S-adenosyl-L-methionine, adenosine and methionine in the rat

The effect of the chronic intramuscular administration of some agents related to the S-adenosyl-L-methionine system on the hyperammonemia syndrome was evaluated. This experimental syndrome was induced in the rat by intraperitoneal administration of high doses of ammonium acetate (33, 100 and 300 mg/kg/day, 6 days a week for 80 days) followed by the assay of the activities of some cerebral enzymes involved in energy transduction. The enzymatic activities studied in the homogenate and in the mitochondrial fractions of brain tissue were: lactate dehydrogenase, citrate synthase, malate dehydrogenase, total NADH-cytochrome c reductase and cytochrome oxidase. All three doses of ammonium acetate induced significant modifications in the cerebral enzymatic activities. These doses reduced the activity of the total NADH-cytochrome c reductase both in the homogenate and in the mitochondrial fraction. On the other hand the activity of malate dehydrogenase was reduced limited to the two lower doses in the homogenate only. The simultaneous daily treatment (i.m.) with equimolar doses of substances involved in the S-adenosyl-L-methionine system (adenosine, methionine and S-adenosyl-L-methionine) did not cause any significant modification of the cerebral enzymatic activities associated with the administration of ammonium acetate at the three dose levels, thus confirming our previous results.

Metabolic changes induced by acute hypoxia on the synaptosomes from dog brain

Synaptosomal preparations from the motor area of the cerebral cortex of normocapnic, normoxic or hypoxic untreated beagle dogs and phenobarbital-, papaverine-, and (-) eburnamonine-treated dogs were incubated for 10 min at 24 degrees C and analyzed for ATP, ADP, AMP creatine phosphate, pyruvate, and lactate. The data were compared with those obtained from the whole controlateral cortical motor area, by the surface-freezing technique. Both during normoxia and after hypoxic hypoxia (15 min, at PaO2 equal to 17-19 mm Hg) the metabolite contents and ratios were very different in the incubated synaptosomal preparations and in the whole cerebral tissues. As concerns the drug treatment, papaverine was always inactive, while (1) eburnamonine increased the synaptosomal phosphorylation state in hypoxic dogs, being ineffective on the glycolytic metabolites evaluated. Phenobarbital increased the synaptosomal phosphorylation state both in normoxic and in hypoxic animals, and was effective also on the glycolytic metabolites studied.

Drug interference on some biochemical parameters of rat cerebral cortex during post-ischemic recovery

Glycolytic substrates and metabolites (glycogen, glucose, glucose-6-phosphate, pyruvate, lactate), tricarboxylic acid cycle intermediates (citrate, alpha-ketoglutarate, succinate, fumarate, malate), related amino acids (glutamate, glutamine, alanine, gamma-aminobutyrate) and energy mediators (ATP, ADP, AMP, creatine phosphate) were evaluated in the cerebral cortex of rats after 5 min of complete compression ischemia as well as after 3, 15 or 30 min of recirculation following 5 min ischemia. The post-ischemic recovery was studied in control animals or in animals treated (30 min before ischemia and during discovery) by intravenous perfusion of vincamine, theophylline, dihydroergocristine and alanine. Interrelated changes of intermediates of the carbohydrate and the amino acid metabolism have been observed. It is concluded that alanine perfusion induced a partial detour of the lactacid anaerobic process towards the succinate-related alactacid cycle, leading to an increase in the cortical gamma-aminobutyrate content. Vincamine and dihydroergocristine acted in the opposite direction.

In vitro action of uridine diphosphate glucose (UDPG) on phrenic diaphragm preparations

The action of uridine-5'-diphosphoglucose (UDPG) on the contractile response of the phrenic diaphragm preparation from guinea pig was investigated. UDPG activity was assayed on the preparation at rest or during the exercise; in this case indirect electrical stimulation of phrenic diaphragm preparation or direct stimulation of denervated or curarized muscle were employed. Krebs' solutions adequately modified with regard to glucose concentration were used. The effect of UDPG on the neuromuscular junction was also investigated by recording miniature end plate potentials. An effect of the drug on neuromuscular transmission and on glucose metabolism could be demonstrated.