Search PubMed⌕ Search

Biomedical subjects

M Paul

Publications and source records attributed to M Paul.

428 records · Page 24Linked to original sources
PubMedDate not supplied

A method for studying synaptosomal release of neurotransmitter candidates, as evaluated by studies on cortical cholecystokinin octapeptide release.

A method for perfusing rat cortical synaptosomes for studying the regulation of cholecystokinin octapeptide (CCK-8) release has been developed and was found to have advantages over the static incubation system. Synaptosomes isolated from rat cortex were suspended in Biogel P2 columns and perfused with Krebs Ringer Bicarbonate buffer. One hundred mM KCl and 75 microM veratine stimulated CCK-8 release, which was Ca++-dependent. The synaptosomes were functionally viable for at least 135 min of incubation as indicated by multiple 100 mM KCl depolarizations and uptake of (3H)-norepinephrine and (14C)-choline. Dopamine and acetylcholine (10(-6)M) stimulated CCK-8 release while serotonin and norepinephrine were without effect. Approximately 20% of total occluded CCK-8 was released from synaptosomes by 100 mM KCl and degradation of CCK-8 was less than 10%. Perfusion of synaptosomes has several advantages over static incubation systems and allows systematic studies on the role of neurotransmitter in the regulation of neuropeptide secretion.

Acetylcholine↗
PubMedDate not supplied

[Trevira: a new polyester implant for the treatment of incisional hernia. Results of an experimental study].

OBJECTIVE: The synthetic implant meshes in clinical use for the treatment of abdominal hernias are generally made of polyester in France and of polypropylene in Germany. Serving as an implant material for the replacement of the cruciate ligament, the Trevira is another polymer of polyester in clinical use with excellent results. This animal trial was performed to ascertain whether it offers any advantages over polypropylene for abdominal incisional hernia repair. MATERIAL AND METHODS: [corrected] In 12 pigs 10 x 10 cm of the abdominal wall preserving the peritoneum was resected and subsequently implanted a 15 x 15 cm synthetic mesh of polyethylene terephthalate (Trevira) in half of them and of polypropylene (Prolene) in the other half using a sublay technique. After two and six month the implant size was measured and the extend of the foreign body reaction determined by the microscopically presence of foreign body giant cells. RESULTS: No significant differences concerning the implant size were shown between the two groups at any of the time periods. The acute inflammatory reaction observed was significantly higher at the polypropylene than at the polyethylene terephthalate implant (number of giant cells after 2 month: Prolene 2.2 +/-0.4, Trevira: 0.8 +/-0.2, after six month: Prolene: 4.6 +/-1.3, Trevira: 1.1 +/-0.5). In contrast to the polyethylene terephthalate all polypropylene samples showed calcification areas after six month. CONCLUSION: In this animal trial Trevira mesh showed a high biocompatibility with a low foreign body reaction. It appears to be a promising new implant for the treatment of hernia.

Animals↗
PubMedDate not supplied

Harmonisation of rat fetal skeletal terminology and classification. Report of the Third Workshop on the Terminology in Developmental Toxicology. Berlin, 14-16 September 2000.

The initial efforts of the Federal Institute for Health Protection of Consumers and Veterinary Medicine (BgVV) and the Free University of Berlin to standardise terminology in the field of developmental toxicology began in 1995. Procedures were undertaken to harmonise the terminology used by the International Federation of Teratology Societies (IFTS) and the International Programme on Chemical Safety (IPCS). This article reflects these activities and is a report on the Third Workshop on the Terminology in Developmental Toxicology held in September 2000. This Workshop served as a forum to discuss the results of a survey on the classification of skeletal anomalies that had been previously sent to scientists active in the field. Although high agreement was reached among the evaluators for several terms, the use of a number of terms was rather variable. Therefore, the discussions at the workshop among the experts from research institutions, regulatory agencies, and industry were mainly focussed on those terms for which there was disagreement and/or uncertainties and the possible reasons. Pictures provided by the participants for the illustration of "grey zone" anomalies constituted the basis for detailed discussions. In many of the cases with lower agreement, decisions were facilitated by the provision of the corresponding picture. The main reasons for lower agreement were imprecise terms, insufficient knowledge on postnatal consequences, theoretical terms that are unlikely to occur in isolation, and the possibility of observing a range of severity that might be decisive for the classification of either a malformation or variation. The attendees concluded that "grey-zone" anomalies will never disappear completely and that for the assessment, the grade of severity and/or the frequency of the observation can be decisive for the terminology chosen. A Joint IPCS/IFTS Project was proposed to further consensus of terminology and classification and to link these anomalies to pictures at different skeletal sites. In order to support the harmonisation of regulatory decisions, it was proposed to establish a "Clearinghouse" System under the umbrella of the IPCS. The Clearinghouse could be contacted either by the regulatory authorities or by any company to clarify their queries, particularly with regard to registration or authorisation processes. Finally, it was recommended to also carry out a similar survey on "soft tissue anomalies" and "external findings." The results of this survey will be discussed at a Joint IPCS/IFTS Workshop in Berlin in 2002.

Abnormalities, Drug-Induced↗
PubMedDate not supplied

In utero exposure to low doses of bisphenol A lead to long-term deleterious effects in the vagina.

The origins of the "endocrine disrupter hypothesis" may be traced to reports on adolescent daughters born to women who had taken the highly potent synthetic estrogen, diethylstilbestrol, while pregnant, and who developed a rare form of vaginal cancer and adenocarcinoma. Bisphenol A (BPA) is an estrogenic chemical that is highly employed in the manufacture of a wide range of consumer products. Some observational studies have suggested that the amounts of BPA to which we are exposed could alter the reproductive organs of developing rodents. We examined the influence of BPA at low doses to address the questions of (a) whether in utero exposure affects the vagina of the offspring and (b) which mechanisms cause the toxic effects. Gravid Sprague-Dawley dams were administered either 0.1 (low dose) or 50 mg/kg per day BPA, the no observed effect level, or 0.2 mg/kg per day 17 alpha-ethinyl estradiol by gavage. Striking morphological changes were observed in the vagina of postpubertal offspring leading us to examine vaginal estrogen receptor (ER) expression because BPA binds to the ER alpha, which is important for growth of the vaginal epithelium. We show that the full-length ER alpha is not expressed during estrus in the vagina of female offspring exposed to either dose of BPA when compared to the control group, whereas ER alpha expression does not differ from the control group during the diestrus stage. ER alpha downregulation seems to be responsible for the observed altered vaginal morphology.

Animals↗
PubMedDate not supplied

Cyclodextrin inclusion complexes of the central analgesic drug nefopam.

Inclusion complexes of nefopam base (NEF) with various beta-cyclodextrins (betaCDs) were investigated. All tested betaCDs increased the apparent solubility of NEF according to a Higuchi AL type plot (except betaCD: AN type plot), which indicates the formation of 1:1 stoichiometry inclusion complexes. 1H-NMR and 13C-NMR experiments showed that complexation by CDs allowed an easy separation of the R and S enantiomers. Based on spectral data obtained from the two-dimensional rotating frame nuclear Overhauser effect spectroscopy (2D-ROESY), a reasonable geometry for the complexes could be proposed implicating the insertion of the benzoxazocine ring into the wide end of the torus cavity.

Administration, Sublingual↗
PubMedDate not supplied

The brain renin-angiotensin system: molecular mechanisms of cell to cell interactions.

The components of the Renin-Angiotensin System (RAS) have been found to be expressed in the brain. Angiotensinogen, the high molecular weight precursor of the system, is widely distributed and expressed in areas not related to control of blood pressure and body fluid homeostasis as well. It has been shown that it is regulated by steroid hormones independently from the liver and that it is also regulated in a different manner in several brain areas. Angiotensin II, the effector peptide of the system, may be generated in the brain via the classical pathway, using renin and angiotensin converting enzyme or directly from angiotensinogen by cathepsin G or tonin. N-terminal peptides of angiotensin II have been found in several brain areas with ANG (1-7) involved in vasopressin release however without influence on blood pressure and with ANG III acting as potent as ANG II. Transgenic animals may be used to study the pathophysiology of an activated brain RAS.

Angiotensin II↗
PubMedDate not supplied

Etiological agents of diarrhoea.

Two decades of research have established newer pathogens and techniques in establishing several organisms of diarrhoeal diseases as aetiological agents. It is now possible to detect an agent in 80% of the situation of diarrhoea in a standard laboratory. The brief review describes the list of pathogens, their diagnostic techniques with short description on clinical and epidemiological status.

Bacterial Infections↗
PubMedDate not supplied

Myocardial high-energy phosphate depletion in allograft rejection after orthotopic human heart transplantation.

The present study was designed to assess whether acute rejection affects myocardial energy content of the human orthotopically transplanted heart. Adenosine triphosphate content was measured in one tissue sample obtained during 46 routine right ventricular endomyocardial biopsies 6 to 455 days (98 +/- 110) after transplantation in 19 cyclosporine-treated transplant recipients. Tissue samples were immediately frozen in liquid nitrogen within 10 seconds after excision. Adenosine triphosphate analysis was performed with high performance liquid chromatography. Three groups of biopsy specimens were classified according to the standardized cardiac biopsy grading system. Group 1: Eight biopsy specimens without rejection; group 2: 24 biopsy specimens with mild rejection; group 3: 14 biopsy specimens with moderate or severe rejection. Graft systolic function evaluated by echocardiographic fractional shortening was in the normal range the day of biopsy. All patients had normal coronary angiograms within 1 month of the study. In the presence of mild rejection (grade 1A or 1B), adenosine triphosphate content was not significantly different from that of nonrejecting hearts (26.15 +/- 7.1 and 28.57 +/- 8.23 nmol/mg protein, respectively). By contrast, a significant decrease in adenosine triphosphate content was observed when moderate or severe rejection with focal or diffuse aggressive infiltrates were present (10.46 +/- 4.11 nmol/mg protein; p < 0.01 versus two other groups). In seven cases, sequential analysis showed a significant increase in adenosine triphosphate content after rejection therapy concomittant with histologic improvement: 10.19 +/- 2.9 before and 30.13 +/- 7.0 nmol/mg protein after treatment (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMedDate not supplied

Reduced production of the deleterious hydroxyl free radical during the final reperfusion of isolated rabbit heart with the use of an improved sodium lactobionate-based cardioplegic medium.

The production of free radicals during the reperfusion of hearts after prolonged ischemia might be responsible for the deleterious effects observed. Several strategies have attempted to limit this production or trap the radicals produced. This study aimed to evaluate the efficacy of a sodium lactobionate-based solution supplemented with 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, a stable nitroxide free radical, in scavenging hydroxyl radicals produced during the reperfusion of the isolated rabbit heart. 4-Hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl was administered just before the end of the storage period (6 hours) in a cardioplegic solution, either crystalloid solution or sodium lactobionate-based solution. The production of hydroxyl radicals was assessed through the production of dihydroxybenzoic acid, a reaction compound of hydroxyl radicals with salicylate. Two main isomers of dihydroxybenzoic acid were found in the coronary effluents: 2,3 and 2,5 dihydroxybenzoic acid. The production was 40-fold lower when the hearts received sodium lactobionate-based solution than when they received crystalloid solution (p < 0.001). The presence of 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl had no influence on the production of hydroxyl radicals. The production of hydroxyl radicals was maximal during the first minute of the reperfusion. Iron ions, directly involved in the production of hydroxyl radicals, were shown to be complexed by sodium lactobionate in vitro. These results underlie the important role of lactobionate in the prevention of the reperfusion injury and the inefficacy of 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl to decrease the production of hydroxyl radicals.

Adenine↗
PubMedDate not supplied

A lactobionate-based extracellular-type solution for donor heart preservation.

The University of Wisconsin solution, which contains the impermeant lactobionate and has an intracellular-type electrolyte composition, has been shown to improve donor heart preservation. Because a deleterious effect of the intracellular-type solutions has been reported, we evaluated a new lactobionate-based extracellular-type solution, by comparing it with University of Wisconsin solution and a crystalloid cardioplegic solution in 45 rabbit hearts. Hearts were arrested by infusion of these solutions and immersed in the same solution (lactobionate-based extracellular-type solution, University of Wisconsin solution) or in the lactated Ringer's solution (crystalloid cardioplegic solution) for 6 hours at 4 degrees C. A Langendorff circuit was used for reperfusion. Left ventricular compliance was better preserved with both lactobionate-based solutions than with the crystalloid cardioplegic solution. Adenosine triphosphate was best preserved with the lactobionate-based extracellular-type solution after arrest and after reperfusion, whereas reperfusion arrhythmias were less marked with the University of Wisconsin solution. These results suggest that lactobionate plays an important role in the preservation of ventricular compliance and that the lactobionate-based extracellular-type solution is preferable for adenosine triphosphate preservation. Further study will be required to assess the factors predisposing to reperfusion arrhythmias.

Adenine↗
PubMedDate not supplied

Breastfeeding practices in Indonesia.

UNLABELLED: Breastfeeding promotion program was started by the paediatricians and others in 1977, and is becoming a strong activity since 1990 it was declared by the President of the Republic of Indonesia as a National Movement. One year later the First Lady stated the importance of every Indonesian mother to breast-feed her baby, and thereafter many hospitals created the so called "Baby Friendly Hospital". In this occasion we only limit with eminent topics, i.e., "Exclusive Breast-feeding" in Indonesia, and "Breastfeeding amongst Working Mothers." In fact, until now the percentage of mothers who breastfeed exclusively is very low. Although the ever breastfed babies in Indonesia is 97% (Kodyat, 1996) but the data of the "Exclusive Breastfeeding" of Indonesia is just like Pakistan and Thailand, i.e. nearly 2 months, whereas the Philippines and Ceylon showed a figure of 4 months, and India 5 months. The Home Health Survey (SKRT) data in 1992 showed that 63.7% of the babies were exclusively breast-fed until 3 months. Three quarter of the quality of the exclusive breastmilk is quite good, enough or excellent, whereas the other one quarter is poor and this should be interfered by increasing the quality of the breastmilk and/or adding other formula, to prevent the baby of getting "failure to thrive" (Suharyono, 1996). Working mothers use to do "Early Weaning Practices" with very high mixed feeding practices (Matulessy et al, 1996). Mothers have to go to work because they have to support their family income, but unfortunately most of them ignore their main task of care their children. IN CONCLUSION: the experience in Indonesia proves that a very hard work should still be continued on the effort of promoting breastfeeding, especially regarding the two issues, i.e. "Exclusive breastfeeding" (we do hope at least until 4 months) and the other issue is regarding the "Working Mothers".

Breast Feeding↗