Search PubMed⌕ Search

Biomedical subjects

G Abraham

Publications and source records attributed to G Abraham.

At least 19 recordsLinked to original sources
PubMed2006

Segment-dependent expression of muscarinic acetylcholine receptors and G-protein coupling in the equine respiratory tract.

Muscarinic receptors are considered to be of comparable clinical importance in chronic obstructive pulmonary disease (COPD) in equines and in humans. At present, data are scarce on the expression and distribution of probable subtypes of these receptors and their signalling pathways in airway segments, including lung parenchyma and bronchial and tracheal epithelium with the underlying smooth muscle in horses. Specific [N-methyl-3H]scopolamine chloride ([3H]NMS) binding to all three tissues was saturable and of high affinity, with KD values ranging between 1.6+/-0.7 and 1.9+/-0.3 nmol/L. [3H]NMS binding identified a higher density of total muscarinic receptors (fmol/mg protein) in the trachea (720+/-59 nmol/L) than in bronchi (438+/-48 nmol/L) or lung (22 +/- 3 nmol/L). Competitive binding studies using [3H]NMS and the unlabelled subtype-selective antagonists pirenzepine and telenzepine (M1), methoctramine and himbacine (M2), 4-diphenylacetoxy-N-methylpiperidine (4-DAMP) (M3), tropicamide (M4) and mamba toxin (MT-3) (M4) indicated the presence of at least three muscarinic receptor subtypes in peripheral lung tissue (50:40:24-28%: M2>M3>M1), whereas in bronchus and trachea M2 subtypes (87-90%) predominated over M3 (14-22%), and M1 subtypes were lacking. No differences were found between tissues in high-affinity binding sites for carbachol in the absence (31-36%) or presence of guanosine 5'-triphosphate (GTP) (approximately 100%). Western blotting for G-protein alpha-subunits showed a much more robust expression of G(alphai1/2) in the trachea (with highest receptor density) than in the lung or bronchi, whereas G(alphas)-protein was dominantly expressed in bronchus. Concomitantly, carbachol inhibited isoproterenol- and GTP-stimulated adenylyl cyclase activity with increasing muscarinic receptor expression (trachea > bronchi > lung). We conclude that the expression and signalling pathways of muscarinic receptors in the equine respiratory tract are segment-dependent. These receptors might contribute to the pathogenesis of COPD in the horse and could provide potential drug targets for the therapeutic use of anticholinergics in this species.

Adenylyl Cyclases↗
PubMed2006

Amphiphilic diblock copolymers with adhesive properties: I. Structure and swelling with water.

We study asymmetric block copolymers with the simple diblock AB architecture, in the case where the longer block A is both hydrophobic and "soft", whereas the shorter block B is hydrophilic and "hard". Materials with such a particular combination of physico-chemical and mechanical properties have distinctive advantages, in particular for designing water-compatible adhesive materials. The phase diagram is established, combining NMR and SAXS characterisations of the materials. The swelling with water is monitored through gravimetry and "time-resolved" SAXS. Indications of maintained adhesive properties in a wet environment are given.

Journal Article↗
PubMed2006

[Sexual problems after allogenic stem cell transplantation].

Allogenic stem cell transplantation is an effective procedure for malignant haematological diseases, for these reasons the number of long-term survivors has increased as well as the concern for their quality of life. The late effects of transplantation can highly influence the patient's sexuality and relationships through psychological and physical factors. Psychological factors: regression due to sickness, staff-dependency, emotional and physical partner-dependence, distress related to sterility. Physical factors: hypo-oestrogenism, genital mucosae dryness and sometimes vulval or vaginal chronic graft-versus-host disease. Addressing the topic of intimacy may cause anxiety and embarrassment among nurses, haematological staff and practitioners with the risk of leaving patients in a sort of "conspiracy of silences".

Adult↗
PubMed2006

[Sleep and sexuality].

Our knowledge about the multiple aspects of sleep functions are still insufficient. Concerning the relationship between sleep and sexuality there are four points of view to take into account. Two observations: a spontaneous sexual excitement during REM sleep and that some anxious dreams can produce also sexual arousal. Two hypotheses: the erotic pleasure could be easier to perceive in a sleeping or dreaming state than in a waking state and some sleeping troubles could have an important influence on the sexual life of a couple.

Humans↗
PubMed2006

Renal abscess.

This study analyses the pre-disposing factors, diagnostic modalities, therapeutic options and prognostic factors involved in 7 subjects with renal abscess. Most often they presented with high fever and flank pain. USG and CT were used to establish the diagnosis. Urine culture yielded organisms in five cases and hence empirical antibiotic therapy for Gram-negative organism was offered. Complicated abscess in our series carried high mortality especially in immuno suppressed and cachectic patients.

Abscess↗
PubMed2006

Correlation of anemia, secondary hyperparathyroidism with left ventricular hypertrophy in Chronic Kidney Disease patients.

AIMS: To demonstrate the correlation of anemia and intact parathormone with left ventricular hypertrophy in a cohort of Chronic Kidney Disease (CKD) patients in a tertiary care centre. METHODS: A cross-sectional study was done over 2 years on 230 renal failure patients (160 males, 70 females), aged 15-75 years, who had elevated serum creatinine and reduced GFR. The patients were assessed based on clinical history and a number of laboratory parameters including serum creatinine, calcium, iPTH level, Hb, Hct, GFR and LVMI. Settings : Patients were seen as inpatients and outpatients in a tertiary care centre. RESULTS: In CKD stages I, II and III, 51% of the patients had anemia Hb<11gm/dl), 16%of the patients had elevated iPTH, 79% of male patients and 71% of female patients had LVH. In Stage IV CKD, 55% of the patients had anemia, 25% of the patients had elevated iPTH, 74% of male patients and 100% of female patients had LVH. In stage V CKD, 76% of the patients had anemia, 31% of the patients had elevated iPTH, 77% of male patients and 96% of female patients had LVH. In all five stages, 78% of male patients and 71% of female patients with elevated iPTH had LVH, 81% of male patients and 90% of female patients with anemia had LVH. Systemic hypertension was present in 69% of the patients. CONCLUSION: Anemia is widely prevalent in our cohort of CKD patients. Severity of anemia is correlated to LVH and secondary hyperparathyroidism in these patients.

Adolescent↗
PubMed2005

Alpha1-and beta2-adrenoceptors in the human liver with mass-forming intrahepatic cholangiocarcinoma: density and coupling to adenylate cyclase and phospholipase C.

Besides the regulation of hepatic metabolic pathways in which adrenoceptors are mainly involved, their effect on the second messenger cAMP is thought to be related to the growth and differentiation of neoplastic cells. However, few studies have been done on the status of these structures in the human liver affected by cholangiocarcinoma (CC). Thus, in this study, changes in densities of alpha1- and beta2-adrenoceptors (alpha1-and beta2-ARs) were investigated in membranes of human liver with cholangiocarcinoma, and for comparison, in membranes of non-adjacent non-tumour liver using the potent antagonists [3H]-prazosin and [1I]-iodocyanopindolol (ICYP) respectively. In addition, the activity of membrane-bound phospholipase C (PLC) and adenylate cyclase (AC) was also studied. In CC liver, the density of alpha1-and beta2-ARs was significantly reduced, compared with non-tumour liver tissues (alpha1-ARs: 23.38+/-4.69 vs 80.35+/-10.52, P=0.0002 beta2-ARs: 14.27+/-2.93 vs 33.22+/-4.32 fmol/mg protein, P=0.03), whereas the ligand affinities (KD) remained unchanged. The beta2-selective antagonist ICI 118,551 was about 100 times more potent in inhibiting ICYP binding than the beta1-selective antagonist CGP 20712A; thus, more than 98% of the beta-ARs were of the beta2-subtypes. The AC activity upon stimulants acting on beta-AR (isoprenaline), G-protein (GTP, NaF) and AC (forskolin) was decreased in CC liver. Similarly, noradrenaline-stimulated PLC activity was significantly reduced in tumour tissues. In conclusion, in CC liver the alpha1- and beta2-ARs density was down-regulated and the neoplastic invasion blunted AC and PLC activity. These quantitative changes may help to elucidate not fully understood pathogenetic mechanisms of disturbed hepatic metabolic processes, such as hypoglycemia during cancer in human liver.

Adenylyl Cyclases↗
PubMed2005

Antimicrobial activity of Curcuma zedoaria and Curcuma malabarica tubers.

The antimicrobial activity of extracts of Curcuma zedoaria and Curcuma malabarica tubers was tested against six bacterial and two fungal strains using the agar well diffusion and broth dilution methods. Petroleum ether, hexane, chloroform, acetone and ethanol extracts exhibited antibacterial as well as antifungal activity. Acetone and hexane extracts of both tubers showed comparable antimicrobial activity as indicated by minimum inhibitory concentration (MIC) values, but other extracts of Curcuma malabarica showed significantly lower activity than those of Curcuma zedoaria. The MIC values for different strains and extracts ranged from 0.01 to 0.15 mg/ml in Curcuma zedoaria and from 0.01 to 0.94 mg/ml in Curcuma malabarica. Staphylococcus aureus (Gram positive) was inhibited by Curcuma malabarica but not by Curcuma zedoaria. This study is the first report of the antimicrobial properties of Curcuma malabarica. The findings also support the use of Curcuma zedoaria tubers in traditional medicine for the treatment of bacterial and fungal infections.

Anti-Infective Agents↗
PubMed2005

Antibody seroprevalences against peste des petits ruminants (PPR) virus in camels, cattle, goats and sheep in Ethiopia.

A questionnaire-survey data indicated that 26% of 276 farmers reported the presence of respiratory disease in their herds in 2001. The incidence was perceived as "high" in small ruminants and camels, but as "low" in cattle. Simultaneously, 2815 serum samples from camels (n=628), cattle (n=910), goats (n=442) and sheep (n=835) were tested. The peste des petits ruminants (PPR) antibody seroprevalence was 3% in camels, 9% in cattle, 9% in goats and 13% in sheep. The highest locality-specific seroprevalences were: camels 10%, cattle 16%, goats 22% and sheep 23%. The animals had not been vaccinated against rinderpest or PPR. Antibody seroprevalences detected in camels, cattle, goats and sheep confirmed natural transmission of PPR virus under field conditions.

Animals↗
PubMed2004

Induction of biomolecules in mature leaves of Terminalia arjuna due to feeding of Antheraea mylitta Drury.

Terminalia arjuna is an important food plant of the tasar silkworm, Antheraea mylitta Drury. In this study, we investigated the induction of biomolecules in mature leaves of these plants subjected to insect feeding. Increase in total tannin content, lipid peroxidation, and trypsin inhibitor activity have been observed in mature leaves damaged by the insects. The growth rate of Vth instar larvae of A. mylitta fed on previously damaged foliage reduced by 87.1%. Induction of biomolecules for defense mechanisms in relation to herbivore damage has been discussed.

Animals↗
PubMed2004

Possible role of dexamethasone in sensitizing the beta-2-adrenergic receptor system in vivo in calves during concomitant treatment with clenbuterol.

Beta(2)-Agonists blunt the function of the beta-adrenoceptor G-protein adenylate cyclase-signalling system, whereas glucocorticoids reverse the agonist-mediated diminished beta-adrenergic responses; however, these effects have not been reported in vivo in calf lymphocytes. In this study, we first investigated the presence of the beta(2)-adrenergic receptors on calf lymphocytes, and second we tested the effects of either clenbuterol alone or in combination with dexamethasone on receptor expression and function (isoproterenol-induced intracellular adenosine 3',5'-cyclic monophosphate (cAMP) formation) in vivo. (-)-[(125)I]-Iodocyanopindolol (ICYP) binding to intact calf lymphocytes was rapid, saturable (maximal number of binding sites 987 +/- 89 ICYP-binding sites/cell, n = 4) and of high affinity (K(D) value 17.23 +/- 2.8 pmol/l, n = 4). These binding sites were of the beta(2)-subtypes of adrenoceptors as indicated by the fact that beta-agonists inhibited ICYP binding with an order of potency: (-)-isoproterenol > (-)-adrenaline > (-)-noradrenaline. Furthermore, the selective beta(2)-adrenoceptor antagonist ICI 118.551 was about >1,500 times more potent in inhibiting ICYP binding than was the beta(1)-selective adrenoceptor antagonist CGP 20712A. Consequently, calves were treated with clenbuterol (1.0 microg/kg b.i.d., i.v.) for 9 days alone or simultaneously with dexamethasone (0.1 mg/kg, i.v., once a day for 4 days). Clenbuterol decreased the number of lymphocyte beta(2)-adrenergic receptors by about 40-50% after only 48 h of drug administration. This was accompanied by a decrement in isoproterenol-induced lymphocyte cAMP formation. Upon application of both drugs, dexamethasone restored the clenbuterol-mediated decrease in beta(2)-adrenoceptors and cAMP production. Dexamethasone elevated the number of beta(2)-adrenoceptors and cAMP almost 1.5- to 2-fold at 24 h of drug administration, an effect that persisted for up to 24 h following drug withdrawal. Neither clenbuterol nor the combination with dexamethasone had an influence on the affinity of the receptor for the ligand. The present results demonstrate that dexamethasone in vivo upregulates the number and function of calf lymphocyte beta(2)-adrenoceptors, and thus enhances the sensitivity of the beta(2)-adrenoceptor signal-transduction pathway for clenbuterol during concomitant treatment with both drugs.

Adrenergic beta-2 Receptor Agonists↗
PubMed2003

Dexamethasone-induced increase in lymphocyte beta-adrenergic receptor density and cAMP formation in vivo.

The influence of dexamethasone on the density of beta(2)-adrenergic receptors (beta(2)-adrenergic receptors (beta(2)AR) and on the intracellular adenosine 3',5'-cyclic monophosphate (cAMP) response was studied in equine lymphocytes in vivo. Dexamethasone (0.1 mg/kg/day, 1-5 days) raised the number of beta(2)AR - B(max) as assessed by (-)-[(125)I]iodocyanopindolol binding (ICYP) - to 2.5- to 3.5-fold as compared with control values. The increase in beta(2)AR number was fast (342 +/- 49 vs. 960 +/- 103 binding sites/lymphocyte after 24 h), reaching a maximum between 48 and 96 h (342 +/- 49 vs. 1,289 +/- 150 and 1,106 +/- 68 binding sites/lymphocyte, respectively). The isoprenaline-induced cAMP accumulation (measured by a [(3)H]-cAMP radioimmunoassay system) was concomitantly enhanced by dexamethasone (1.5- to 2.4-fold). Both parameters were reversible to a similar rate at dexamethasone withdrawal. The changes in the functional responsiveness of lymphocytes were not reflected by changes in the binding affinity for ICYP of beta(2)AR. These results demonstrate the in vivo glucocorticoid-mediated regulation of beta(2)AR in equine lymphocytes which has already been suggested on the basis of in vitro observations in other tissues.

Animals↗