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1.
Bioresour Technol ; 101(22): 8881-90, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20663664

ABSTRACT

Thermo-catalytic pyrolysis of refuse derived fuels with different catalysts had been conducted in a two stages process due to its important potential value as fuel. The first stage was a pure thermal pyrolysis in a horizontal tubular reactor with feed rate of 0.5kg hourly. The second stage was a semi-batch process in the presence of catalysts. Results showed that the tested catalysts significantly have affected the quantity of products. E.g. gas yield could be increased with 350% related to the catalyst free case using ZSM-5, while that of pyrolytic oil was 115% over Y-zeolite. Gases consisted of mainly CO and CO(2) obtained from the tubular reactor, while dominantly hydrocarbons from the second stage. Ni-Mo-catalyst and Co-Mo-catalyst had shown activity in pyrolytic oil upgrading via in-situ hydrogenation-dehydrogenation reactions. Sulphur, nitrogen and chlorine level in pyrolytic oils could be significantly declined by using of catalysts.


Subject(s)
Biofuels , Industrial Waste/prevention & control , Refuse Disposal/methods , Catalysis , Hot Temperature
2.
J Biochem Biophys Methods ; 70(6): 1247-53, 2008 Apr 24.
Article in English | MEDLINE | ID: mdl-17602751

ABSTRACT

Waste high-density polyethylene was converted into different hydrocarbon fractions by thermal and thermo-catalytic batch cracking. For the catalytic degradation of waste plastics three different catalysts (equilibrium FCC, HZSM-5 and clinoptilolite) were used. Catalysts differ basically in their costs and activity due to the differences of micro- and macroporous surface areas and furthermore the Si/Al ratio and acidities are also different. Mild pyrolysis was used at 430 degrees C and the reaction time was 45 min in each case. The composition of products was defined by gas chromatography, Fourier transform infrared spectroscopy, size exclusion chromatography, energy-dispersive X-ray fluorescence spectroscopy and other standardized methods. The effects of catalysts on the properties of degradation products were investigated. Both FCC and clinoptilolite catalysts had considerably catalytic activity to produce light hydrocarbon liquids, while HZSM-5 catalyst produced the highest amount of gaseous products. In case of liquids, carbon numbers were distributed within the C5-C23 range depending on the cracking parameters. Decomposition of the carbon chain could be followed by GC and both by FTIR and SEC techniques in case of volatile fractions and residues. Catalysts increased yields of valuable volatile fractions and moreover catalysts caused both carbon chain isomerization and switching of the position of double bonds.


Subject(s)
Chemistry Techniques, Analytical/instrumentation , Chemistry Techniques, Analytical/methods , Conservation of Natural Resources , Hydrocarbons/analysis , Plastics/chemistry , Carbon/chemistry , Catalysis , Gases/chemistry , Molecular Weight , Sanitary Engineering
3.
Talanta ; 69(3): 776-80, 2006 May 15.
Article in English | MEDLINE | ID: mdl-18970637

ABSTRACT

The element content of low and high sulfur containing diesel fuels was measured by different analytical methods: energy-dispersive X-ray fluorescent (EDXRF) and inductively coupled plasma atomic emission (ICP-OES) spectroscopy methods. Then results were compared. High sulfur containing diesel fuels were from heavy diesel engines and diesel fuel-like liquids obtained by thermal degradation of waste polymers. In case of X-ray analysis also the effect of the used thin foils with different chemical compositions (polypropylene, polycarbonate, polyester) on the accuracy was investigated. According to data considerable differences and deterioration of accuracy was observed in the respect of foils in case of both low and high sulfur containing hydrocarbons. Results indicated appropriate correlation between experimental results measured by both two methods, but differences could be observed in the correlation, which could be explained with different ratio of C/H of samples.

4.
Neurology ; 64(11): 1884-7, 2005 Jun 14.
Article in English | MEDLINE | ID: mdl-15955938

ABSTRACT

PURPOSE: Gyratory seizures (GSs) have been rarely described in generalized as well as in focal epilepsies. They were defined as a rotation around the body axis during a seizure for at least 180 degrees. The mechanisms of generation are unknown and have been discussed controversially. The aim of this investigation was to further delineate seizure semiology and assess a possible lateralizing and localizing value of GSs. METHODS: The authors screened 277 consecutive patients with intractable epilepsies referred to a University Hospital for presurgical evaluation between 1998 and 2004 for GSs: 169 had temporal lobe epilepsy (TLE), 47 frontal lobe epilepsy (FLE), 38 generalized epilepsies (GE), and 23 had extratemporal or multifocal epilepsy. RESULTS: Twelve patients showed gyratory movements in 17 seizures. Eight had FLE and four TLE (p < 0.001). In 58% (7/12), the gyratory movement was initiated by a forced versive movement of the head followed by a rotation toward the contralateral side of seizure onset. In 42% (5/12), the gyratory movement was not preceded by a forced head version. In these seizures, the direction of the rotation was toward the side of seizure onset. CONCLUSIONS: The direction of rotation lateralizes seizure onset zone in focal epilepsy depending on the seizure evolution: 1) gyratory seizures (GSs) starting with a forced version of the head ensuing into a body rotation lateralize seizure onset zone contralateral to the direction of rotation. 2) In GSs without a preceding gyratory forced head version, the direction of rotation is toward the side of seizure onset. GSs occur more frequently in frontal lobe epilepsy than temporal lobe epilepsy, while none of our patients with GSs had generalized epilepsies.


Subject(s)
Brain/physiopathology , Epilepsy/complications , Epilepsy/diagnosis , Movement Disorders/diagnosis , Movement Disorders/etiology , Adult , Aged , Basal Ganglia/physiopathology , Disease Progression , Electroencephalography , Epilepsy/physiopathology , Epilepsy, Tonic-Clonic/physiopathology , Female , Head Movements/physiology , Humans , Male , Middle Aged , Models, Neurological , Movement Disorders/physiopathology , Neural Pathways/physiopathology , Posture/physiology , Rotation , Video Recording
5.
J Neurol Neurosurg Psychiatry ; 76(6): 808-14, 2005 Jun.
Article in English | MEDLINE | ID: mdl-15897504

ABSTRACT

OBJECTIVE: To evaluate interictal language functions in patients with medically intractable left and right sided mesial temporal lobe epilepsy (TLE). METHODS: Spontaneous speech, language comprehension, confrontation naming, repetition, reading, writing, and word fluency were examined in 12 patients with left sided TLE and 11 patients with right sided TLE. RESULTS: Four patients out of 23 displayed language deficits in more than one language domain. Three further patients exhibited isolated language deficits. Linguistic deficits were observed in both left TLE and right TLE. In quantitative analyses left and right TLE only differed in spontaneous speech (p = 0.02); no difference was found in other language functions, laterality quotient of Wada test, or overall IQ. Qualitative error analysis of object naming, however, showed typical errors associated only with left TLE. Patients with linguistic deficits were older at testing compared to patients without linguistic deficits (p = 0.003), whereas other factors including side of TLE, handedness, educational level, age at epilepsy onset, and duration of epilepsy did not differ between groups. CONCLUSIONS: Possible explanations for these findings include neuronal cell loss and deafferentiation in cortical areas, and disruption of the basal temporal language area pathways. Our study suggests that some patients with chronic mesial TLE exhibit linguistic deficits when specifically tested, and underlines the need to routinely investigate linguistic functions in TLE.


Subject(s)
Epilepsy, Temporal Lobe/complications , Language Disorders/etiology , Adult , Aged , Brain/pathology , Brain Diseases/pathology , Electroencephalography , Epilepsy, Temporal Lobe/diagnosis , Female , Functional Laterality/physiology , Hippocampus/pathology , Humans , Language Disorders/diagnosis , Language Tests , Magnetic Resonance Imaging , Male , Middle Aged , Sclerosis/pathology , Severity of Illness Index , Time Factors , Videotape Recording
6.
Talanta ; 66(5): 1264-71, 2005 Jun 15.
Article in English | MEDLINE | ID: mdl-18970117

ABSTRACT

Low sulphur concentration in hydrocarbon products as fuels or lubricants is an important requirement for the high quality standards of refineries. A non-polarised energy dispersive X-ray fluorescence spectroscopy (EDXRFS) and sample combustion technique (ASTM D6428-99) was compared. A new application of energy dispersive X-ray spectrometry as analytical method for the determination of sulphur in fuels and fuel-like fractions was investigated. Low sulphur containing fuels and hydrocarbon mixtures obtained by thermal cracking of waste polymers were measured and the influence of C/H ratio on accuracy was studied. The concentration of sulphur in samples was measured with calibration graphs of different hydrocarbon matrices (commercial gasoline, diesel oil and white oil were used). Good correlation was observed between the different methods, but the correlation was depending on the characteristics of the matrices. Detection limits of 1.0ppm, 1.1ppm and 0.9ppm were obtained for S in gasoline, diesel oil and white oil, respectively.

7.
Haemophilia ; 10 Suppl 2: 50-2, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15385047

ABSTRACT

Summary. Participants in an international workshop on surgery in haemophilia patients with inhibitors developed a consensus summary of the findings and conclusions of the meeting. In the consensus, participants agreed upon revised definitions for minor and major surgery, including an intermediate degree of surgery. An evaluation system of intraoperative and postoperative bleeding was developed. Recommended doses of FEIBA((R)) and rFVIIa (both in bolus injections and in continuous infusion) for surgery were agreed. Participants also agreed on the main blood tests to be performed peri-operatively. They also suggested the need of a prospective evaluation in the future. Finally, the approximate number of surgical procedures and costs performed on haemophilia patients with inhibitors were analysed.


Subject(s)
Hemophilia A/surgery , Adult , Blood Coagulation Factors/antagonists & inhibitors , Blood Coagulation Factors/therapeutic use , Factor VIIa/therapeutic use , Hemophilia A/drug therapy , Hemophilia A/physiopathology , Hemophilia B/drug therapy , Hemophilia B/physiopathology , Hemophilia B/surgery , Hemostasis/physiology , Humans , Intraoperative Complications/prevention & control , Middle Aged , Postoperative Hemorrhage/prevention & control , Practice Guidelines as Topic , Recombinant Proteins/therapeutic use , Treatment Outcome
8.
J Neurol Neurosurg Psychiatry ; 75(6): 901-3, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15146011

ABSTRACT

BACKGROUND: Specific cognitive impairments have been found in association with mesial temporal lobe epilepsy (TLE), such as deficits in declarative memory or verbal abilities. No attention has been paid so far to possible deficits in number processing. OBJECTIVE: To investigate deficits in number processing in patients with TLE. METHODS: Numerical abilities were assessed in 28 right handed patients with medically intractable unilateral TLE and in a control group. RESULTS: No differences between patients and controls were found in analogue number processing with Arabic input, in a comparison task, or in simple addition and simple subtraction; however, there were significant group differences in tasks with verbal input, in simple division, in complex mental calculation, in a semantic knowledge task, and in conceptual tasks. Only minor differences were found between patients with right and left TLE. CONCLUSIONS: While numerical deficits may be expected in patients with left sided TLE, it is open for discussion why patients with right sided TLE also show numerical deficits.


Subject(s)
Cognition Disorders/diagnosis , Epilepsy, Temporal Lobe/diagnosis , Mathematics , Neuropsychological Tests , Problem Solving , Adult , Cognition Disorders/physiopathology , Cognition Disorders/psychology , Concept Formation , Epilepsy, Temporal Lobe/physiopathology , Epilepsy, Temporal Lobe/psychology , Functional Laterality , Humans , Semantics , Temporal Lobe/physiopathology , Verbal Behavior
9.
Brain Res Cogn Brain Res ; 18(1): 76-88, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14659499

ABSTRACT

Aim of the present functional magnet resonance imaging (fMRI) study was to detect modifications of cerebral activation patterns related to learning arithmetic. Thirteen right-handed subjects were extensively trained on a set of 18 complex multiplication problems. In the following fMRI session, trained and untrained problems (closely matched for difficulty) were presented in blocked order alternating with a number matching task and a fact retrieval task. Importantly, left hemispheric activations were dominant in the two contrasts between untrained and trained condition, suggesting that learning processes in arithmetic are predominantly supported by the left hemisphere. Contrasting untrained versus trained condition, the left intraparietal sulcus showed significant activations, as well as the inferior parietal lobule. A further significant activation was found in the left inferior frontal gyrus. This activation may be accounted for by higher working memory demands in the untrained as compared to the trained condition. Contrasting trained versus untrained condition a significant focus of activation was found in the left angular gyrus. Following the triple-code model [Science 284 (1999) 970], the shift of activation within the parietal lobe from the intraparietal sulcus to the left angular gyrus suggests a modification from quantity-based processing to more automatic retrieval. The present study shows that the left angular gyrus is not only involved in arithmetic tasks requiring simple fact retrieval, but may show significant activations as a result of relatively short training of complex calculation.


Subject(s)
Brain Mapping/methods , Cerebral Cortex/physiology , Learning/physiology , Magnetic Resonance Imaging/methods , Mathematics , Adult , Female , Humans , Male , Statistics, Nonparametric
10.
Neurology ; 60(5): 873-6, 2003 Mar 11.
Article in English | MEDLINE | ID: mdl-12629252

ABSTRACT

The authors describe seven patients with medically refractory temporal lobe epilepsy whose seizures were associated with peri-ictal water drinking behavior. Presurgical evaluation, including video-EEG monitoring, MRI, SPECT, and neuropsychological testing, revealed a seizure onset in the nondominant temporal lobe. All patients had an excellent outcome after epilepsy surgery. Peri-ictal water drinking may represent a lateralizing sign indicating seizure onset in the nondominant temporal lobe.


Subject(s)
Drinking , Epilepsy, Temporal Lobe/complications , Epilepsy, Temporal Lobe/surgery , Stereotypic Movement Disorder/complications , Thirst , Adolescent , Adult , Child , Child, Preschool , Electroencephalography , Epilepsy, Temporal Lobe/diagnosis , Epilepsy, Temporal Lobe/physiopathology , Female , Follow-Up Studies , Functional Laterality , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Monitoring, Intraoperative , Tomography, Emission-Computed, Single-Photon , Water
11.
J Neurol Neurosurg Psychiatry ; 74(2): 222-5, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12531955

ABSTRACT

OBJECTIVE: To undertake a prospective study of the long term neuropsychological outcome in patients with late onset idiopathic aqueduct stenosis (LIAS) after endoscopic third ventriculostomy. METHODS: Six patients with LIAS were evaluated pre- and postoperatively using magnetic resonance imaging (MRI) and standardised psychometric testing procedures. Endoscopic third ventriculostomy was done using standard surgical techniques. The mean long term follow up was 81.2 weeks. RESULTS: Preoperatively, all patients had cognitive impairment, four of them showing deficits in several cognitive domains. After endoscopic third ventriculostomy, all patients improved clinically and had ventricular size reduction on MRI. Postoperative neuropsychological testing showed that five patients achieved normal or near normal cognitive functions, and one improved moderately. CONCLUSIONS: Endoscopic third ventriculostomy caused a substantial improvement in the neuropsychological deficit of LIAS patients. This was also true for patients with enlarged ventricles that might be diagnosed radiologically as "arrested hydrocephalus."


Subject(s)
Cerebral Aqueduct/surgery , Endoscopy , Hydrocephalus/surgery , Neuropsychological Tests , Ventriculostomy/methods , Adult , Cerebral Aqueduct/pathology , Constriction, Pathologic , Female , Follow-Up Studies , Humans , Hydrocephalus/diagnosis , Hydrocephalus/psychology , Magnetic Resonance Imaging , Male , Middle Aged , Neurologic Examination , Postoperative Complications/diagnosis , Postoperative Complications/psychology , Prospective Studies , Third Ventricle/pathology , Third Ventricle/surgery , Treatment Outcome
12.
Neurology ; 59(8): 1254-6, 2002 Oct 22.
Article in English | MEDLINE | ID: mdl-12391359

ABSTRACT

In patients with secondarily generalized tonic-clonic seizures (sGTCS) an asymmetric termination of the clonic phase can be observed. The authors systematically analyzed this phenomenon in patients with temporal lobe epilepsy (TLE). Thirty-nine sGTCS from 29 patients with TLE who underwent successful epilepsy surgery were analyzed, in addition to a prospectively collected group of 28 patients with TLE who had 35 sGTCS. The clonic phase of sGTCS did not end synchronously in 65.7% of all patients and in 59.4% of all seizures. In 79.3% to 80% this was ipsilateral to the hemisphere of seizure onset, and there was excellent interobserver agreement.


Subject(s)
Epilepsy, Temporal Lobe/epidemiology , Seizures/epidemiology , Adult , Chi-Square Distribution , Epilepsy, Temporal Lobe/physiopathology , Epilepsy, Temporal Lobe/surgery , Female , Follow-Up Studies , Humans , Male , Middle Aged , Prospective Studies , Seizures/physiopathology , Seizures/surgery , Video Recording/methods
13.
Clin Orthop Relat Res ; (391 Suppl): S328-36, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11603716

ABSTRACT

Efficacious treatment of full-thickness cartilage defects of the weightbearing surfaces is a multi-faceted challenge for the orthopaedic surgeon. Autologous osteochondral transplantation represents one solution: to bring about a hyaline or hyalinelike repair of the defected area. The current authors discuss the experimental background and their 8 years of clinical experience with the autologous osteochondral mosaicplasty. Several series of animal studies and subsequent clinical practice have confirmed the survival of the transplanted hyaline cartilage. Hyaline cartilage and fibrocartilage fill the donor sites located on the nonweightbearing surfaces and surfaces that bear less weight. Clinical scores, imaging techniques, control arthroscopies, histologic examination of biopsy samples, and cartilage stiffness measurements were used to evaluate the clinical outcomes and quality of the transplanted cartilage. According to these investigations, femoral condylar implantations have shown good to excellent results in 92%, tibial resurfacing in 88%, patellar and/or trochlear mosaicplasties in 81%, and talar procedures in 94% of patients. The Bandi score showed long-term donor site disturbances in 3% of patients. Fifty-eight of the 68 control arthroscopies had good gliding surfaces, histologically-proven survival of the transplanted hyaline cartilage, and fibrocartilage covering of the donor sites. In the entire series, there were four deep infections and 34 painful hemarthroses after surgery. A multicentric, comparative, prospective evaluation of 413 arthroscopic resurfacing procedures (mosaicplasty, Pridie drilling, abrasion arthroplasty, and microfracture cases in homogenized subgroups) showed that mosaicplasty gave a more favorable clinical outcome in the long-term followup, than the other three techniques. Intermediate-term evaluation of the femoral condylar implantations (3-6-years followup) and talar mosaicplasties (3-7-years followup) confirmed the durability of the early results. From these encouraging results from an increasingly large series and similar results from other centers, it seems that autologous osteochondral mosaicplasty may be a viable alternative treatment of localized full-thickness cartilage damage of the weightbearing surfaces of the knee and other weightbearing synovial joints.


Subject(s)
Ankle Injuries/surgery , Cartilage, Articular/injuries , Cartilage, Articular/surgery , Knee Injuries/surgery , Adolescent , Adult , Follow-Up Studies , Humans , Middle Aged , Orthopedic Procedures/methods
14.
J Pept Sci ; 4(8): 486-95, 1998 Dec.
Article in English | MEDLINE | ID: mdl-9927255

ABSTRACT

Small cell lung cancer (SCLC) cell lines produce and secrete various peptide hormones, e.g. bombesin (BN)/gastrin releasing peptide (GRP) like peptides that are proposed to function as their autocrine growth factors. To inhibit the proliferative effect of these hormones we have synthesized short chain BN[7-14]-analogues replacing the C-terminal peptide bond by a methylene-amino (-CH2NH-) unit and introducing D-Phe or D-Ser into position 12. As several substance P (SP) analogues were found to inhibit the growth of SCLC cells, some short chain SP-analogues have been synthesized. (Pseudo)octapeptides were synthesized in solution, by fragment condensation using the DCC/HOPfp method. Fragments and SP-analogues were synthesized stepwise using pentafluorophenyl esters. The resistance to hydrolysis of the reduced peptide bond made permitted exact quantification of the Leupsi(CH2NH)Leu pseudopeptide in hydrolysates. The binding ability of both types of peptides to BN-receptors on Swiss 3T3 mouse fibroblast cells and their antiproliferative effect on NCI-H69 human SCLC cell line have been tested and compared with a short chain SP-antagonist pHOPA-D-Trp-Phe-D-Trp-Leu-Leu-NH2 (R) previously described as a potent inhibitor of SCLC proliferation. While BN-analogues showed weak activity in inhibition of proliferation of SCLC cells, SP-analogues 6: D-MePhe-D-Trp-Phe-D-Trp-Leu(psi)(CH2NH)-Leu-NH2 and 7: D-MePhe-DTrp-Phe-D-Trp-Leu-MPA, in spite of greatly diminished affinity towards the BN-receptor, inhibited SCLC proliferation more effectively than R (6: IC50 = 2 microM, 7: IC50 = 5 microM and R: IC50 = 10 microM). Moreover, 6 inhibited the respiratory activity of SK-MES 1 epithelial type of lung carcinoma cells in proliferating but not in the quiescent state, suggesting that the antiproliferative effect of these compounds is not due to simple cytotoxicity. These short chain analogues of SP might be promising candidates as therapeutic agents in the treatment of SCLC.


Subject(s)
Amides , Carcinoma, Small Cell/pathology , Lung Neoplasms/pathology , Peptides/chemical synthesis , 3T3 Cells , Amino Acid Sequence , Animals , Bombesin/analogs & derivatives , Bombesin/antagonists & inhibitors , Bombesin/chemistry , Bombesin/pharmacology , Cell Division/drug effects , Humans , Hydrolysis , Mice , Molecular Sequence Data , Substance P/analogs & derivatives , Substance P/chemistry , Substance P/pharmacology , Tumor Cells, Cultured
15.
Int J Cancer ; 60(1): 82-7, 1995 Jan 03.
Article in English | MEDLINE | ID: mdl-7529212

ABSTRACT

Human small-cell lung-cancer cells (SCLC) produce and secrete gastrin-releasing peptide (GRP), the mammalian equivalent of bombesin (BN). There is some evidence to suggest that GRP is an autocrine regulator of SCLC cell growth. In the search for potent BN antagonists, several substance-P (SP) analogs were found to inhibit the growth of SCLC cells. We found that a known short-chain SP antagonist, pHOPA-DTrp-Phe-DTrp-Leu-Leu-NH2(NY3238), inhibits the binding of 125I-Tyr4-BN on Swiss 3T3 cell line expressing BN receptors, as well as the proliferation of NCI-H69 SCLC cells. In this study we tested several analogs of NY3238 and we found that NY3521 and NY3460 are more effective in inhibition of proliferation of SCLC cells but less potent in inhibition of binding of 125I-Tyr4-BN on Swiss 3T3 cells than NY3238. Furthermore, we detected specific binding of radiolabelled NY3238 even below 1 nM on NCI-H69 cells that could have been inhibited by SP and NY3460 rather than by BN. In addition to these in vitro studies, NY3460 proved to be effective in inhibiting the growth of NCI-H69 SCLC xenografts in nude mice in vivo. These analogs of NY3238 could be promising therapeutic agents in the treatment of SCLC.


Subject(s)
Carcinoma, Small Cell/drug therapy , Lung Neoplasms/drug therapy , Oligopeptides/pharmacology , Substance P/analogs & derivatives , Substance P/antagonists & inhibitors , 3T3 Cells , Amino Acid Sequence , Animals , Bombesin/antagonists & inhibitors , Carcinoma, Small Cell/metabolism , Carcinoma, Small Cell/pathology , Cell Division/drug effects , Female , Humans , Kinetics , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Mice , Mice, Inbred BALB C , Mice, Nude , Molecular Sequence Data , Neoplasm Transplantation , Oligopeptides/metabolism , Substance P/metabolism , Substance P/pharmacology , Transplantation, Heterologous , Tumor Cells, Cultured/drug effects
16.
Brain Res ; 563(1-2): 171-4, 1991 Nov 01.
Article in English | MEDLINE | ID: mdl-1786530

ABSTRACT

To examine the hypothesis that the increased adrenocortical activity during lactation induced the loss of the prolactin (PRL) -releasing effect of morphine, we studied the effect of morphine in adrenalectomized (ADX) and sham-operated primiparous lactating Wistar rats. Animals were adrenalectomized 4 days after delivery. On day 11 of lactation (7 days after ADX), pups were separated from their mother 2 h before morphine or haloperidol injection. Intravenous injection of 5 mg/kg morphine did not change plasma PRL levels in the sham-operated lactating rats, but it resulted in a significant increase of plasma PRL levels in ADX lactating animals, with or without corticosterone replacement. Catalepsy following 10 mg/kg i.v. morphine was also markedly enhanced in ADX lactating animals. The PRL response to 0.5 mg/kg haloperidol was higher in ADX lactating animals than that in the controls. Morphine given 2 h after haloperidol treatment resulted in a further increase of plasma PRL in ADX, but not in the sham-operated lactating animals. These results suggest that adrenal hyperfunction may lead to a loss of sensitivity to morphine during lactation.


Subject(s)
Adrenalectomy , Lactation/physiology , Morphine/pharmacology , Prolactin/blood , Animals , Catalepsy/chemically induced , Catalepsy/physiopathology , Corticosterone/pharmacology , Female , Haloperidol/pharmacology , Rats , Rats, Inbred Strains , Receptors, Dopamine/drug effects , Receptors, Dopamine/physiology
17.
Brain Res ; 563(1-2): 107-13, 1991 Nov 01.
Article in English | MEDLINE | ID: mdl-1664769

ABSTRACT

We studied the effect of dexamethasone (DEX) implantation in male Wistar rats to elucidate the site of action of morphine-induced prolactin (PRL), growth hormone (GH), adrenocorticotropic hormone (ACTH) and corticosterone (B) secretion. DEX or cholesterol was implanted in the close vicinity of the paraventricular (PVN), or the arcuate nuclei (ARN) of the hypothalamus or into the hippocampus. Five days after implantation blood samples were taken 30 min after i.p. morphine by decapitation or through an indwelling cannula 15, 30, 60 min after i.v. injection. DEX implanted near the PVN resulted in a blockade of morphine-induced ACTH and B secretion. In contrast, GH response to morphine was enhanced, while that of PRL was unchanged. DEX implanted near the ARN significantly inhibited the PRL-releasing effect of morphine, but was without any influence on the PRL secretion induced by haloperidol. There was a partial reduction in the B response to morphine, and GH secretion was unchanged. Dorsal hippocampal implants were without any effect on the morphine-induced GH, PRL or B secretion. We suggest that the site of glucocorticoid inhibitory action in the hypothalamus is the PVN for the opiate-induced ACTH/B secretion, and the ARN for the morphine-induced PRL release. The enhanced GH response to morphine observed in DEX-PVN implanted rats might be due to a decreased somatostatin tone.


Subject(s)
Brain/physiology , Dexamethasone/pharmacology , Morphine/pharmacology , Pituitary Hormones/blood , Adrenocorticotropic Hormone/blood , Animals , Arcuate Nucleus of Hypothalamus/drug effects , Arcuate Nucleus of Hypothalamus/metabolism , Brain/anatomy & histology , Brain Chemistry/drug effects , Corticosterone/blood , Dexamethasone/administration & dosage , Drug Implants , Growth Hormone/blood , Hydrocortisone/pharmacology , Male , Paraventricular Hypothalamic Nucleus/drug effects , Paraventricular Hypothalamic Nucleus/metabolism , Prolactin/blood , Rats , Rats, Inbred Strains , Stereotaxic Techniques
18.
Endocrinology ; 129(2): 635-40, 1991 Aug.
Article in English | MEDLINE | ID: mdl-1855462

ABSTRACT

The effect of dexamethasone (DEX) treatment (400 and 200 micrograms/kg BW 21 and 2 h before suckling stimulus, respectively) on suckling- and domperidone (DOMP)-induced PRL release was investigated in freely moving, primiparous lactating rats. DEX completely blocked suckling-induced plasma PRL release without affecting DOMP-induced release of the hormone suggesting a central action of DEX. The effect was transient because it could not be detected on the second day of testing. The effect of DEX implanted in three different brain areas on suckling- and DOMP-induced PRL release was also tested. Implants surrounding the hypothalamic paraventricular nuclei and dorsal hippocampus failed to affect PRL release induced by suckling stimulus. Surprisingly, DEX suppressed PRL release induced by suckling stimulus when it was implanted into the medial basal hypothalamus. These findings demonstrate that DEX is a potent inhibitor of the suckling-induced PRL release. They also indicate that the site of action of DEX is not at the anterior pituitary gland or the paraventricular nuclei and hippocampus because DEX treatment and DEX implants had no effect on plasma PRL levels induced by DOMP and suckling stimulus, respectively. Our data suggest that the effect of DEX is mediated through a region of the medial basal hypothalamus. The observed transient block in suckling-induced PRL release may be physiologically relevant during stress in lactating mothers for conserving pituitary stores of the hormone needed for milk production or being able to adapt to a rapid change in osmoregulation.


Subject(s)
Dexamethasone/pharmacology , Lactation/physiology , Prolactin/metabolism , Animals , Cholesterol/pharmacology , Domperidone/pharmacology , Hippocampus/drug effects , Hippocampus/physiology , Hypothalamus, Middle/drug effects , Hypothalamus, Middle/physiology , Rats
19.
Neuroendocrinology ; 53(5): 516-22, 1991 May.
Article in English | MEDLINE | ID: mdl-1678497

ABSTRACT

The relationship between opioidergic and alpha 2-adrenergic system in the regulation of GH secretion was studied using a novel alpha 2-antagonist, CH-38083, and chronic treatment with yohimbine or clonidine. In male Wistar rats morphine (3 mg/kg s.c.), and clonidine (31 micrograms/kg i.p.) induced a significant increase in plasma GH levels. The pretreatment with the alpha 2-antagonist yohimbine (1 and 3 mg/kg) effectively inhibited the GH releasing effect or morphine and clonidine. CH-38083 at the dose of 1 mg/kg did not interfere with the morphine-induced GH secretion, while it fully antagonized the GH-releasing effect of clonidine. Higher doses (3 and 5 mg/kg) of CH-38083 only partly inhibited GH secretion induced by morphine. In rats chronically treated with clonidine (2 micrograms/ml in the drinking water for 14 days) the GH response to an injection of clonidine was blocked, while the effect of morphine on the GH secretion remained unchanged. In long-term castrated rats the effect of clonidine (15, 31 and 250 micrograms/kg i.p.) on the GH secretion was significantly blunted, while the GH-releasing effect of morphine (1, 3 and 5 mg/kg s.c.) remained unchanged. The replacement of testosterone (10 mg/kg for 4 days) in castrates restored the effect of clonidine, whereas it decreased the stimulatory action of morphine on the GH secretion. In rats chronically treated with yohimbine (2 mg/kg i.p. 2-3 times daily for 14 days until sacrifice), the GH response to a high dose of clonidine (0.5 mg/kg i.p.) was blocked, while the effect of morphine (5 mg/kg s.c.) was significantly enhanced.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Growth Hormone/metabolism , Morphine/pharmacology , Receptors, Adrenergic, alpha/physiology , Adrenergic alpha-Antagonists/pharmacology , Animals , Berberine/analogs & derivatives , Berberine/pharmacology , Clonidine/pharmacology , Male , Orchiectomy , Rats , Rats, Inbred Strains , Testosterone/pharmacology , Yohimbine/pharmacology
20.
Brain Res ; 506(2): 323-6, 1990 Jan 08.
Article in English | MEDLINE | ID: mdl-2302570

ABSTRACT

Seven days after adrenalectomy (ADX) the number of vasoactive intestinal peptide (VIP)- and corticotropin-releasing factor (CRF)-immunoreactive cells in the parvocellular part of the rat paraventricular nucleus (PVN) increased markedly. Dexamethasone in the drinking water (started immediately after ADX) or its local implantation around the hypothalamic PVN reduced the ADX-induced increase in the number of VIP- and CRF-like immunoreactive neurones. The present results suggest that PVN might be the site at which glucocorticoids inhibit the increase in VIP-positive cells after ADX.


Subject(s)
Adrenal Glands/physiology , Dexamethasone/pharmacology , Paraventricular Hypothalamic Nucleus/metabolism , Vasoactive Intestinal Peptide/metabolism , Adrenalectomy , Animals , Drug Implants , Immunohistochemistry , Male , Paraventricular Hypothalamic Nucleus/cytology , Paraventricular Hypothalamic Nucleus/drug effects , Rats , Rats, Inbred Strains
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