Effects of cocaine on the contents of neurohypophyseal hormones in the plasma and in different brain structures in rats

The effects of acute and chronic cocaine treatments on the levels of the neurohypophyseal hormones oxytocin (OXT) and vasopressin (AVP) in the plasma and in different brain structures in rats were measured by radioimmunoassay (RIA). Acute cocaine treatment had no effect on the level of OXT in the plasma or in the amygdala, but increased OXT contents were measured in the hypothalamus and in the hippocampus. The OXT levels in the basal forebrain structures (including the septum and the nucleus accumbens) were decreased by a single dose of cocaine. The acute injection of cocaine increased the level of AVP in the plasma, and decreased contents of OXT were measured in the amygdala and in the basal forebrain. Repeated treatment with cocaine decreased the level of OXT in the plasma, hypothalamus and hippocampus. The AVP contents were decreased in all of the brain structures investigated, but no change was caused in the plasma level of AVP by repeated injections of cocaine. These results demonstrate complex, region-specific interactions between cocaine and the neurohypophyseal hormones in the brain and in the periphery underlying the alteration in behavioral and autonomic functions caused by acute and chronic cocaine exposure.

Inhibition by D-MePhe-Pro-Arg-H (GYKI-14766) of thrombus growth in experimental models of thrombosis

The antithrombotic action of the highly effective synthetic thrombin inhibitor D-MePhe-Pro-Arg-H (GYKI-14766) was studied in various models of experimental thrombosis. The compound administered to rats and rabbits by i.v. bolus injections, continuous i.v. infusions, subcutaneously and orally, respectively, induced significant decrease in thrombus weight (i) in a quantitative venous thrombosis model with stasis based on vascular lesion in rats, (ii) in an extracorporeal arterio-venous shunt model in rabbits, and (iii) prevented the occlusion of the vessel in arterial thrombosis induced by mechanical damage in rats. By using the arterio-venous shunt model in rabbits the inhibitory effect on thrombus growth could be demonstrated as a function of dose and time in self-controlled experiments. Blood level of the inhibitor determined by a bioassay varied between 0.09-0.67 microgram/ml whole blood when doses of 15 and 20 mg/kg were administered orally. A correlation was found between thrombin time, platelet aggregation induced by thrombin ex vivo and the weight of thrombi formed.

[Familial occurrence of Gorlin-Goltz syndrome]

A case of familial Gorlin-Goltz syndrome is described from the clinical point of view. The importance of early diagnosis, adequate treatment and care are emphasized.

Oxytocin modulates behavioural adaptation to repeated treatment with cocaine in rats

Behavioural adaptation to and the effects of the neurohypophyseal peptide, oxytocin, on repeated treatment with cocaine were investigated in rats. The content of immunoreactive oxytocin in the plasma, hypothalamus and different limbic structures in the brain were also studied after treatment with cocaine, identical to that used in the behavioural experiment. Repeated administration of cocaine (7.5 mg/kg, s.c.) produced a behavioural tolerance to the stereotyped sniffing-inducing effect of the challenge doses (1.875, 3.75 and 7.5 mg/kg, s.c.) of cocaine on the fifth day, which was demonstrated by parallel shifting of the dose-response and time-effect curves of the test doses of cocaine. The development of tolerance was inhibited by pretreatment with oxytocin (0.05 micrograms, (s.c.), administered before each daily injection of cocaine. A smaller dose of oxytocin (0.005 micrograms, s.c.) had no effect in this model. A decreased amount of immunoreactive oxytocin was detected in the plasma, in the hypothalamus and in the hippocampus, after repeated treatment with cocaine. Replacement of oxytocin by local injection (100 pg) into the ventral hippocampus, before each daily administration of cocaine, prevented the development of tolerance to cocaine. These results suggest that endogenous oxytocin, localized in limbic-forebrain areas, may have an important regulatory role in the development of behavioural changes induced by the repeated administration of cocaine.

[Effect of intra-arterial chemotherapy of head and neck tumors on cerebral blood circulation]

A combination of Cisplatin and Epirubicin was administered through the external carotid artery system according to a standard protocol as preoperative or palliative therapy in 14 oral cancer patients. With the aim of clarifying the subacute side-effects of this chemotherapy on the intracerebral circulation, rCBF SPECT investigations with 99mTc-HMPAO were performed before and after the cytostatic treatment. The interval between SPECT studies was 24 (SD +/- 12) days. In concordance with the neurological condition, visual assessment of the rCBF SPECT reconstructed transversal slices revealed no perfusion abnormalities and no changes on the follow-up. No significant changes were found in the side activity ratios in 22 regions of each hemisphere (unpaired t-test) in the whole group of patients. It was concluded that within the investigated time interval this highly effective combination of cytostatics administered perfectly through the external carotid artery system causes no serious disturbances in the cerebral circulation in oral cancer cases.

In vivo anticoagulant and antiplatelet effect of D-Phe-Pro-Arg-H and D-MePhe-Pro-Arg-H

D-Phe-Pro-Arg-H and D-MePhe-Pro-Arg-H synthetized in our institute were administered to mice, rats, rabbits and beagle dogs. The kinetics of the anticoagulant and antiplatelet effect was recorded by measuring various clotting parameters, platelet count and aggregation, and evaluated as proposed by Verstraete and Verwilghen. The minimum effective doses were found to be 0.25-0.5 mg kg-1h-1 by intravenous continuous infusions and 0.5-1.0 mg/kg by single injections. The dose-dependent prolongation of clotting times appeared after application within minutes and returned to baseline values as a function of dose. Blood level of the inhibitors was determined by a bioassay. Unlike heparin, no higher starting dose was required to reach the anticoagulant threshold level, i.e. 0.03-0.1 microgram/ml whole blood. The peptides did not cause significant changes in platelet count and function or in hemodynamic parameters (blood pressure, heart rate and ECG) and in respiration. They blocked platelet aggregation induced by thrombin ex vivo specifically. No rebound effect or bleeding could be demonstrated even after subtoxic doses of the compounds. The onset of the anticoagulant and antithrombotic effect appeared within 60 min after single oral doses and lasted for 3-6 h. In close correlation with the anticoagulant effect a complete or significant inhibition of platelet aggregation induced by thrombin ex vivo could also be recorded by using 5-10 mg/kg doses.

[Use of biomaterials for preventive and restorative purposes]

At the Dept. of Maxillofacial Surgery, Semmelweis University of Medicine many biomaterials have been used in the last 10 year. Author deals with only three materials, such as solid aluminiumoxyde ceramics, titanium screws and HTR Polymers. The Al2O3 ceramics can be used for the reconstruction of the lower jaws, the condyle and the coronoid process of the mandible as well as for dental implants and for the improvement of the facial contour. This material proved to be the most suitable for the reconstruction of the mandible and TM joint. The titanium screw implant (Flexi-root system) has been used in many hundreds of patients with some 90% success rate. The HTR Polymer has been used in the periodontal surgery, in small and medium size cyst operations and sinus lift procedures. The technique of sinus lift has also been discussed.

[Waldenstrm macroglobulinemia presenting in the form of cold urticaria and cold purpura]

A Waldenström macroglobulinemia case, manifested in the form of non-specific skin-symptoms (cold urticaria and cold purpura) is described in a 37 years old female patient. As new skin-symptoms progressive telangiectasia and naevi aranei could be observed. Involvement of skin may be explained by macroglobulins with kryoprotein properties, making early diagnosis possible at the same time.

[Bone transplantation methods]

Author sums on the basis of the literature of this country and of the international literature the more frequently used methods of bone substitution, their mechanical and biological characteristics. On the basis of the practice of their institute and of the international publications it can be stated that beside the usual transplantation of preserved bone the always increasing clinical claim makes the introduction and the knowledge of other methods also necessary. The advantages and disadvantages of the bone grafts of different types are detailed. It is stated that none of the implantates of different characteristics fulfils perfectly the ideal mechanical and biological requirements. To obtain the possibly best result it is recommended to choose, and on individual indication, the bone substitution method that will fulfil in the given case the requirements desired.

Bacteriorhodopsin: a picosecond optoelectric signal transducer

This paper summarizes the results found in our laboratory investigating the ultrafast light-induced charge separation in bacteriorhodopsin. A special technique was elaborated for dried oriented samples of long term stability. An upper limit of 21 ps was found by a direct electric method for the early charge separation processes. A permanent electric field on the surface of illuminated samples was demonstrated. The potential application of such samples as ultrafast optoelectric signal transducers is discussed.

Effects of cocaine and pimozide on plasma and brain alpha-melanocyte-stimulating hormone levels in rats

The effects of cocaine on rat plasma and brain alpha-melanocyte-stimulating hormone (alpha-MSH) levels have been studied by means of a specific radioimmunoassay. The selected brain areas were the hypothalamus, septum-nucleus accumbens and hippocampus. Cocaine given subcutaneously decreased the alpha-MSH levels in the peripheral blood. Pimozide, a dopaminergic antagonist, had an opposite effect: it increased the alpha-MSH levels in the peripheral blood. Combined treatment with cocaine + pimozide resulted in a decrease in the pimozide-induced increase in alpha-MSH levels in the blood. Cocaine and pimozide or the combination of cocaine + pimozide were ineffective on the alpha-MSH levels in the hypothalamus and septum-accumbens brain regions. In the hippocampus, cocaine in the dose applied induced a slight but not significant decrease in the alpha-MSH level. Pimozide caused a significant decrease in the hippocampal alpha-MSH level which disappeared at 60 min. Cocaine prevented the pimozide-induced depletion of alpha-MSH. The data indicate that cocaine may act as a dopaminergic agonist in the mechanism of control of alpha-MSH secretion from the intermediate lobe of the pituitary. The alpha-MSH levels in the brain are controlled by different mechanisms. In some brain areas, the dopaminergic system has no action; in others the mechanisms might be similar to but slightly different from that in the pituitary.

[Enhancement of the ossification of decalcified bone]

Authors have proven with previous experiments that the decalcinated bone can be used as transplant. In this paper their experiments to increase the osteogene capacity of this kind of bone for replacement are described. It is stated that with the use of electric after treatment both the speed of the development of new bone after bone replacement both the rebuilding on the recipient bone ends may be advantageously influenced. With their method the bone defect in the rabbit's radius could be healed in four weeks.

Critical role of endogenous corticotropin-releasing factor (CRF) in the mediation of the behavioral action of cocaine in rats

The role of endogenous CRF in the locomotor hyperactivity induced by cocaine was investigated by using the immunoneutralization of endogenous CRF and an antagonist of CRF-receptors (alpha-helical CRF9-41: alpha h-CRF) in rats. Different dilutions of anti-CRF antibody (1:5, 1:20, but not 1:100) injected intracerebroventricularly (i.c.v.) 24 hours before the cocaine treatment blocked the expression of locomotor hyperactivity. Pretreatment with different doses (0.001, 0.01, 0.1, 1.0 micrograms i.c.v.) of alpha h-CRF inhibited the locomotor hyperactivity induced by cocaine dose-dependently. Neither the immunoneutralization nor the receptor blockade for CRF changed the hyperactivity induced by another locomotor stimulant caffeine. These results serve as indirect in vivo evidence of the selective role of endogenous CRF in the cocaine-induced behavioral alterations. The findings have implications as concerns the possible role of CRF in human psychopathological changes induced by cocaine.

Dispersion measurements of single-mode fibers in the blue-green spectral region by an interferometric method

The chromatic dispersion of a single-mode, polarizationpreserving fiber in the blue-green spectral region was measured by using an interferometric method.

Long-term tissue tolerance of titanium-encapsulated cobalt-samarium implants

The tissue reactions of titanium-coated cobalt-samarium magnets were investigated following their full-thickness implantation into the skulls of dogs and pigs (six of each species). The implants, together with the surrounding bone, were removed en bloc 1, 2, 3, 6, 9, and 12 months postoperatively. Following physical and radiological examinations, the excised samples were subjected to histologic investigation. The osseointegration process was observed to follow a normal course around the titanium capsule. The magnetic field did not give rise to any tissue changes that could be demonstrated by means of classical histologic methods.

HTR polymer and sinus elevation: a human histologic evaluation

HTR (hard tissue replacement) polymer was used in a second session to perform 26 sinus floor elevations in 16 patients with dental implantation (Flexiroot, U.S.A.). A period of 6, 8, 10, or 12 months elapsed between the two operations, making it impossible to examine the tissular integration of HTR from both clinical and human histologic aspects. Following the sinus elevation, neither prolonged wound healing nor a rejection reaction was observed in any of the cases. During an 8 to 10 month period, sufficient new bone and fibrous connective tissue had grown between the HTR granules to ensure appropriate supporting tissue for the implantation. Subsequently (12 months), the HTR and the new bone became clinically increasingly harder, forming a union that was difficult to shape. HTR may be stated to be a material suitable for purposes of sinus elevation. In three cases in which the alveolar bone was originally very thin (2 to 3 mm), the resorption of this bone was observed, as a consequence of this the implantation was not performed. The resorption is explained by the inadequate blood supply that developed for surgical-technical reasons, and is not connected with the nature of the material used for the sinus elevation.

[Osteitis pubis]

Lytic degeneration of the pubic symphysis is a relatively rare entity. The present study is dedicated to the fact that the disease causes numerous diagnostic problems. Authors based on their three cases describe the clinical features and review the literature. It is stated that both from the aspect of the diagnosis and the result of the treatment, operative intervention is beneficial. In contraversion to numerous papers it is found that the described disease is often infectious and can be consequence of an infection of the urinary tract.

[Histological evaluation of the effect of intra-arterial cytostatic treatment]

In cases of untreated mouth cavity carcinomas cisplatin, farmorubicin as well as a combination of the two have been administered intra-arterially to three groups of patients. Result of the treatment was similar tumor regression in all three groups. Thrombotic complications were more frequent in cases treated with farmorubicin. Possibilities of preventing vein damages are reported on.

[Fetal growth rate and its variations 1988/89]

Considering that the last intrauterine growth standards were constructed more than two decades ago, the authors defined the measure of 5, 10, 25, 50, 75, 90 and 95 percentiles of birth weight on the base of Genetic and Obstetric Computer Register of East-Hungary, birth data having epidemiological value in Szabolcs-Szatmár-Bereg, Hajdú-Bihar and Jász-Nagykun-Szolnok counties in 1988-89. From the 36th week of pregnancy the mean values of birth weights between boys and girls, boys and gipsy boys, girls and gipsy girls as well as singular and twin newborn infants differed from each other significantly. Possessing these standards, the clinical judgement and supplying of the various newborn infants can be more exact.

Removal of epulis by CO 2 laser

From analysis of the epulis patient population for 40 years, it could be established that of 1019 lesions, 12.8% relapsed, in 40% of surgical interventions, with the extraction of the tooth involved. For the removal of epulis, we have developed our own method. As a first step, the tumor is excised by CO 2 laser. Thereafter, excochleation and bone decortication are performed, followed, as a third step, by evaporation. In each case, an attempt is made at preserving the teeth. When necessary, radicular treatment and fixation are performed. Postoperatively, minimal edema and pain occurred, and the majority of the patients were able to work on the first postoperative day. Following laser removal of 63 epulides, recurrence was seen in 5 cases (7.9%) without intraoperative tooth extraction. The combined method was applied successfully also in a hemophilic patient. Besides the conventional laser surgical handpiece, an endoscope of own construction was used on surfaces untreatable by direct sight.

[Pathogenesis of severe vision deficiency in school-age children in Hungary]

A population-based aetiological study was carried out on 6 to 14 year-old severely visually handicapped children in Hungary. Of the 547 recorded cases 491 (90%) were included in the analysis. Eleven aetiological groups were separated: isolated cataracts (16.7%), congenital abnormalities of the eye (15.1%), high myopia +/- retinal detachment and other cases (13.4%), retinopathia praematurorum (11.0%), choroidoretinal degenerations (10.0%), syndromes (9.6%), nystagmus and/or hypermetropia (9.0%), isolated and complicated optic atrophy (6.7%), postnatal causes (4.9%), retinoblastoma (1.8%), praenatal causes (1.8%). A significantly higher rate of previous induced abortions was found in the group of retinopathia praematurorum. Perinatal damage syndrome and Mendelian monogenic defects are the two most common aetiological categories in the origin of severe visual handicaps in Hungary.

A new cyclitol derivative influences inositol metabolism in Neurospora crassa

Cyclitol derivatives have been synthesized and screened for growth inhibitory effect upon prokaryotic and eukaryotic organisms. One derivative, (2S,3R,5R)-3-azido-2-benzoyloxy-5-hydroxycyclohexanone, was studied in detail: it has no effect upon bacteria, but it is inhibitory to Neurospora crassa. In Neurospora crassa it increased the amount of myo-inositol-1-phosphate synthase and inhibited the activity of myo-inositol-monophosphatase. The enhanced synthesis of myo-inositol-1-phosphate synthase was the consequence of lowering the intracellular inositol concentration. Li+ treatment of Neurospora crassa has effects similar to those of P.I.-658.

Central effects of antiserum against human atrial natriuretic polypeptide on water and electrolyte metabolism and plasma arginine-8-vasopressin level in conscious rats

Although synthetic atrial natriuretic polypeptide (ANP) is known to influence the water and electrolyte metabolism and arginine-8-vasopressin (AVP) secretion, the physiological role of endogenous ANP in the rat brain is still unclear. Accordingly, an investigation was made of the effects of intracerebroventricular (icv) administration of human h-ANP antiserum, which can neutralize endogenous ANP, on the water intake, urine output, urinary excretion of potassium and sodium, and plasma AVP level in normally hydrated rats. Apart from the water intake, all the parameters were also determined in 48-h water-deprived rats after h-ANP antiserum treatment. The icv administration of the h-ANP antiserum significantly increased the spontaneous water intake, urine output and urinary potassium excretion in rats given water ad libitum. These effects developed by 24 h after icv treatment. The h-ANP antiserum had no effect on the urine volume in 48-h water-deprived rats, suggesting a primary effect of endogenous ANP in the brain on the spontaneous water intake in rats given water ad libitum. These results suggest that ANP may have a physiologically important role in the central regulation of the water and electrolyte metabolism. The h-ANP antiserum did not alter the basal and dehydration-induced AVP release. This raises the possibility that the endogenous ANP in the brain may not participate in the control of AVP secretion.