167 research outputs found

    Botanical Knowledge and its Differentiation by Age, Gender and Ethnicity in Southwestern Niger

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    Indigenous knowledge is unevenly distributed. Individual knowledge level may be affected by many factors such as gender, age, ethnicity, profession, religious and cultural beliefs, abundance and usefulness of the species. This study documents indigenous knowledge of herbaceous and woody plant species of farmers and herders in southwestern Niger. Specifically, we examine the effects of age, gender, and ethnicity on knowledge of local vegetation. Results from the study showed that on average a higher proportion of woody species was identified by the respondents compared to herbaceous species. Both gender and ethnicity had a significant effect on the identification of herbaceous species but no effect on identification of woody species. Respondents in lower age group (10 to 30 years) identified lower number of species compared to other age classes. There seems to be a curvilinear relationship between age of respondents and number of plant species identified. Results from this study reaffirm the uneven distribution of indigenous knowledge within a given area due to social factors. The main challenge is how to incorporate these social differences in knowledge of native plant species into sustainable management and conservation of community natural resources

    Gastrointestinal motility, prokinetic benzamides and serotonin : a study on the guinea-pig colon

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    The prokinetic substituted benzamides stimulate gastrointestinal motility in animal models and in man. Studies done on the isolated guinea-pig ileum have led to the hypothesis that the benzamides act through facilitation of cholinergic transmission due to stimulation of serotonin4 (5-HT 4 ) receptors on the intramural enteric neurons. However, many questions as to their mode of action remain. The substituted benzamides are known to interfere with a variety of 5-HT receptor types. In this thesis the pharmacological action and interaction of substituted benzamides and 5-HT on the guinea-pig proximal colon were studied. This preparation was found to be endowed with 5-HT 3 and 5-HT 4 receptors on the nerves, mediating contraction via the release of acetylcholine and a non-cholinergic neurotransmitter (probably substance P, which stimulates smooth muscle NK 1 receptors), and 5-HT 2A receptors on the smooth muscle. The benzamides cisapride and R 76 186 were found to be agonists at this 5-HT 4 receptor, but cisapride was also found to have an additional direct effect on the smooth muscle. Furthermore, an unknown neuronal 5-HT 2 - like receptor was found to mediate relaxation involving nitric oxide (NO) and adenosine triphosphate (ATP). Cisapride and some other benzamides, were found to selectively enhance the ATP-mediated relaxation. It is thus proposed that the benzamides do not only facilitate the excitatory cholinergic transmission, but also the inhibitory purinergic transmission. As in peristalsis coordinated contraction and relaxation are important, the benzamides might thus promote peristalsis by enhancing both relaxation and contraction on demand. An in vivo model for faecal pellet propulsion in the guinea-pig distal colon was developed to investigate this hypothesis in future studies

    Randomised clinical trial: the efficacy of prucalopride in patients with chronic intestinal pseudo-obstruction - a double-blind, placebo-controlled, cross-over, multiple n = 1 study

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    BACKGROUND: Chronic intestinal pseudo-obstruction is a disabling condition for which there are no established drug therapies. The condition is caused by a diverse range of intestinal myopathies and neuropathies. AIM: To assess the therapeutic efficacy of prucalopride, a selective high-affinity 5-HT(4) receptor agonist, we employed a multiple n = 1 study design. Each patient acted as his/her own control, each day counting as one treatment episode, allowing comparison of 168 days on each of active drug and placebo. METHODS: Double-blind, randomised, placebo-controlled, cross-over trial of four 12-week treatment periods, with 2-4 mg prucalopride or placebo daily. In each of the first and second 6 months there was a prucalopride and a placebo treatment. Patients with proven chronic intestinal pseudo-obstruction, including dilated gut, were included. Evaluation was by patient diary and global evaluation. RESULTS: Seven patients participated (mean 42 years, five female, median symptom duration 11 years). Three discontinued, two due to study length, and one on prucalopride due to unrelated malnutrition and bronchopneumonia. Four patients (three visceral myopathy and one visceral neuropathy) completed the study; prucalopride significantly improved pain in three of four patients, nausea in two, vomiting in one, bloating in four and analgesic intake. Bowel function was not changed substantially. CONCLUSIONS: n = 1 studies in rare conditions allow drug efficacy assessment. Prucalopride relieves symptoms in selected patients with chronic pseudo-obstruction

    Efficacy and Safety of Prucalopride in Patients with Chronic Noncancer Pain Suffering from Opioid-Induced Constipation

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    Opioid-induced constipation (OIC) has negative effects on quality of life (QOL). Prucalopride is a new, selective 5-HT4 agonist and enterokinetic with strong clinical data in chronic constipation. This study investigated the efficacy, safety, and tolerability of prucalopride in patients with noncancer pain and OIC. A phase II, double-blind, placebo-controlled study of 196 patients randomized to placebo (n = 66), prucalopride 2 mg (n = 66) or 4 mg (n = 64), for 4 weeks, was carried out. The primary endpoint was the proportion of patients with increase from baseline of a parts per thousand yen1 spontaneous complete bowel movement (SCBM)/week. Secondary endpoints [proportion of patients with a parts per thousand yen3 SCBM/week, weekly frequency of (SC)BM, severity of constipation, and efficacy of treatment], adverse events (AEs), and safety parameters were also monitored. More patients had an increase from baseline of a parts per thousand yen1 SCBM per week (weeks 1-4) in the prucalopride groups [35.9% (2 mg) and 40.3% (4 mg)] versus placebo (23.4%), reaching statistical significance in week 1. Over weeks 1-4, more patients in the prucalopride groups achieved an average of a parts per thousand yen3 SBM per week versus placebo (60.7% and 69.0% versus 43.3%), reaching significance at week 1. Prucalopride 4 mg significantly improved patient-rated severity of constipation and effectiveness of treatment versus placebo. Patient Assessment of Constipation-Symptom (PAC-SYM) total scores and Patient Assessment of Constipation-Quality of Life (PAC-QOL) total and satisfaction subscale scores were improved. The most common AEs were abdominal pain and nausea. There were no clinically relevant differences between groups in vital signs, laboratory measures or electrocardiogram parameters. In this population with OIC, prucalopride improved bowel function and was safe and well tolerated

    Species and tissue-specificity of prokinetic, laxative and spasmodic effects of Fumaria parviflora

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    <p>Abstract</p> <p>Background</p> <p><it>Fumaria parviflora </it>Linn. (<it>Fumariaceae</it>), is a small branched annual herb found in many parts of the world including Saudi Arabia and Pakistan. This study was designed to provide pharmacological basis for the medicinal use of <it>Fumaria parviflora </it>in gut motility disorders.</p> <p>Methods</p> <p>The <it>in-vivo </it>prokinetic and laxative assays were conducted in mice. Isolated intestinal preparations (ileum and jejunum) from different animal species (mouse, guinea-pig and rabbit) were separately suspended in tissue baths containing Tyrode's solution bubbled with carbogen and maintained at 37°C. The spasmogenic responses were recorded using isotonic transducers coupled with PowerLab data acquisition system.</p> <p>Results</p> <p>The aqueous-methanol extract of <it>Fumaria parviflora </it>(Fp.Cr), which tested positive for the presence of alkaloids, saponins, tannins and anthraquinones showed partially atropine-sensitive prokinetic and laxative activities in the <it>in-vivo </it>in mice at 30 and 100 mg/kg. In the <it>in-vitro </it>studies, Fp.Cr (0.01-1 mg/ml) caused a concentration-dependent atropine-sensitive stimulatory effect both in mouse tissues (jejunum and ileum), and rabbit jejunum but had no effect in rabbit ileum. In guinea-pig tissues (ileum and jejunum), the crude extract showed a concentration-dependent stimulatory effect with higher efficacy in ileum and the effect was partially blocked by atropine, indicating the involvement of more than one types of gut-stimulant components (atropine-sensitive and insensitive). This could be a plausible reason for the greater efficacy of Fp.Cr in gut preparations of guinea-pig than in rabbit or mouse.</p> <p>Conclusions</p> <p>This study shows the prokinetic, laxative and spasmodic effects of the plant extract partially mediated through cholinergic pathways with species and tissue-selectivity, and provides a sound rationale for the medicinal use of <it>Fumaria parviflora </it>in gut motility disorders such as, indigestion and constipation. This study also suggests using different species to know better picture of pharmacological profile of the test material.</p

    Increased cholinergic contractions of jejunal smooth muscle caused by a high cholesterol diet are prevented by the 5-HT(4 )agonist – tegaserod

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    BACKGROUND: Excess cholesterol in bile and in blood is a major risk factor for the respective development of gallbladder disease and atherosclerosis. This lipid in excess negatively impacts the functioning of other smooth muscles, including the intestine. Serotonin is an important mediator of the contractile responses of the small intestine. Drugs targeting the serotonin receptor are used as prokinetic agents to manage intestinal motor disorders, in particular irritable bowel syndrome. Thus, tegaserod, acting on 5-HT(4 )receptor, ideally should obviate detrimental effects of excessive cholesterol on gastrointestinal smooth muscle. In this study we examined the effect of tegaserod on cholesterol-induced changes in the contractile responses of intestinal smooth muscle. METHODS: The effects of a high cholesterol (1%) diet on the in vitro contractile responses of jejunal longitudinal smooth muscle from Richardson ground squirrels to the cholinergic agonist carbachol were examined in the presence or absence of tetrodrodotoxin (TTX). Two groups of animals, fed either low (0.03%) or high cholesterol rat chow diet, were further divided into two subgroups and treated for 28 days with either vehicle or tegaserod. RESULTS: The high cholesterol diet increased, by nearly 2-fold, contractions of the jejunal longitudinal smooth muscle elicited by carbachol. These cholinergic contractions were mediated by muscarinic receptors since they were blocked by scopolamine, a muscarinic receptor antagonist, but not by the nicotinic receptor antagonist, hexamethonium. Tegaserod treatment, which did not affect cholinergic contractions of tissues from low cholesterol fed animals, abrogated the increase caused by the high cholesterol diet. With low cholesterol diet TTX enhanced carbachol-evoked contractions, whereas this action potential blocker did not affect the augmented cholinergic contractions seen with tissues from animals on the high cholesterol diet. Tegaserod-treatment removed the effects of a high cholesterol diet on neuronal muscarinic receptors, as the potentiating effect of TTX on carbachol-elicited contractions was maintained in these animals. CONCLUSION: A high cholesterol diet causes significant changes to cholinergic neurotransmission in the enteric nerves of the jejunum. The mechanisms by which these effects of cholesterol are reversed by tegaserod are unknown, but relate to removal of an inhibitory effect of cholesterol on enteric nerves

    The extracellular matrix glycoprotein tenascin-X regulates peripheral sensory and motor neurones.

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    KEY POINTS: Tenascin-X (TNX) is an extracellular matrix glycoprotein with anti-adhesive properties in skin and joints. Here we report the novel finding that TNX is expressed in human and mouse gut tissue where it is exclusive to specific subpopulations of neurones. Our studies with TNX-deficient mice show impaired defecation and neural control of distal colonic motility that can be rescued with a 5-HT4 receptor agonist. However, colonic secretion is unchanged. They are also susceptible to internal rectal intussusception. Colonic afferent sensitivity is increased in TNX-deficient mice. Correspondingly, there is increased density of and sensitivity of putative nociceptive fibres in TNX-deficient mucosa. A group of TNX-deficient patients report symptoms highly consistent with those in the mouse model. These findings suggest TNX plays entirely different roles in gut to non-visceral tissues - firstly a role in enteric motor neurones and secondly a role influencing nociceptive sensory neurones Studying further the mechanisms by which TNX influences neuronal function will lead to new targets for future treatment. ABSTRACT: The extracellular matrix (ECM) is not only an integral structural molecule, but is also critical for a wide range of cellular functions. The glycoprotein tenascin-X (TNX) predominates in the ECM of tissues like skin and regulates tissue structure through anti-adhesive interactions with collagen. Monogenic TNX deficiency causes painful joint hypermobility and skin hyperelasticity, symptoms characteristic of hypermobility Ehlers Danlos syndrome (hEDS). hEDS patients also report consistently increased visceral pain and gastrointestinal (GI) dysfunction. We investigated whether there is a direct link between TNX deficiency and GI pain or motor dysfunction. We set out first to learn where TNX is expressed in human and mouse, then determine how GI function, specifically in the colon, is disordered in TNX-deficient mice and humans of either sex. In human and mouse tissue, TNX was predominantly associated with cholinergic colonic enteric neurones, which are involved in motor control. TNX was absent from extrinsic nociceptive peptidergic neurones. TNX-deficient mice had internal rectal prolapse and a loss of distal colonic contractility which could be rescued by prokinetic drug treatment. TNX-deficient patients reported increased sensory and motor GI symptoms including abdominal pain and constipation compared to controls. Despite absence of TNX from nociceptive colonic neurones, neuronal sprouting and hyper-responsiveness to colonic distension was observed in the TNX-deficient mice. We conclude that ECM molecules are not merely support structures but an integral part of the microenvironment particularly for specific populations of colonic motor neurones where TNX exerts functional influences

    A History of Drug Discovery for Treatment of Nausea and Vomiting and the Implications for Future Research.

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    The origins of the major classes of current anti-emetics are examined. Serendipity is a recurrent theme in discovery of their anti-emetic properties and repurposing from one indication to another is a continuing trend. Notably, the discoveries have occurred against a background of company mergers and changing anti-emetic requirements. Major drug classes include: (i) Muscarinic receptor antagonists-originated from historical accounts of plant extracts containing atropine and hyoscine with development stimulated by the need to prevent sea-sickness among soldiers during beach landings; (ii) Histamine receptor antagonists-searching for replacements for the anti-malaria drug quinine, in short supply because of wartime shipping blockade, facilitated the discovery of histamine (H1) antagonists (e.g., dimenhydrinate), followed by serendipitous discovery of anti-emetic activity against motion sickness in a patient undergoing treatment for urticaria; (iii) Phenothiazines and dopamine receptor antagonists-investigations of their pharmacology as "sedatives" (e.g., chlorpromazine) implicated dopamine receptors in emesis, leading to development of selective dopamine (D2) receptor antagonists (e.g., domperidone with poor ability to penetrate the blood-brain barrier) as anti-emetics in chemotherapy and surgery; (iv) Metoclopramide and selective 5-hydroxytryptamine3(5-HT3) receptor antagonists-metoclopramide was initially assumed to act only via D2 receptor antagonism but subsequently its gastric motility stimulant effect (proposed to contribute to the anti-emetic action) was shown to be due to 5-hydroxytryptamine4 receptor agonism. Pre-clinical studies showed that anti-emetic efficacy against the newly-introduced, highly emetic, chemotherapeutic agent cisplatin was due to antagonism at 5-HT3 receptors. The latter led to identification of selective 5-HT3 receptor antagonists (e.g., granisetron), a major breakthrough in treatment of chemotherapy-induced emesis; (v) Neurokinin1receptor antagonists-antagonists of the actions of substance P were developed as analgesics but pre-clinical studies identified broad-spectrum anti-emetic effects; clinical studies showed particular efficacy in the delayed phase of chemotherapy-induced emesis. Finally, the repurposing of different drugs for treatment of nausea and vomiting is examined, particularly during palliative care, and also the challenges in identifying novel anti-emetic drugs, particularly for treatment of nausea as compared to vomiting. We consider the lessons from the past for the future and ask why there has not been a major breakthrough in the last 20 years
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