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At least 235 records · Page 13Linked to original sources

PubMed1999

Ab-interno goniotrabeculotomy versus mitomycin C trabeculectomy for adult open-angle glaucoma: a 2-year randomized clinical trial.

OBJECTIVE: To evaluate the effect of ab-interno goniotrabeculotomy (AIGT) on the intraocular pressure (IOP) in adult patients with primary open-angle glaucoma (POAG), compared with the effects of mitomycin C trabeculectomy (MT). DESIGN: Prospective, randomized, clinical trial. PARTICIPANTS: Thirty-two eyes of 32 patients with medically uncontrolled POAG. INTERVENTION: Standard limbus-based trabeculectomy with adjunct mitomycin C (0.3 mg/mL for 3 minutes) in 16 eyes of 16 patients; AIGT was performed in 16 eyes of 16 patients. The groups were matched for age, preoperative IOP, duration of preoperative antiglaucoma treatment, use of preoperative beta-blockers and parasympathomimetics, and use of beta-blockers in the fellow eye. The IOP (average of the two highest values measured in the diurnal curve, from 8 AM to 6 PM, every 2 hours) and complications were recorded 1, 3, 6, 12, 18, and 24 months after surgery. MAIN OUTCOME MEASURES: Identification of complications and IOP. RESULTS: All patients were followed up for 24 months. More postoperative complications occurred in the MT group during the 2-year follow-up. One month after surgery, IOP was 10 +/- 1.46 mmHg (range, 8-13) in the MT group and 12.12 +/- 1.63 mmHg (range, 8-14) in the AIGT group (Student's t test, P = 0.001). Three months after surgery, IOP was 11.5 +/- 1.59 mmHg (range, 8-14) and 12.75 +/- 1.57 mmHg (range, 10-16) in the MT and AIGT groups, respectively (Student's t test, P = 0.033). From the 6th to the 24th postoperative month, no statistically significant difference in IOP was found between the two groups. At the end of follow-up, 14 of 16 eyes (87.5%) of the AIGT group and 13 of the 16 eyes (81.25%) of the MT group showed an IOP < or = 14 mmHg. CONCLUSION: Ab-interno goniotrabeculotomy appears to be a viable and safe surgical treatment for adult POAG. More extended follow-up, however, and a larger series of patients are needed to ascertain the actual effectiveness of this procedure in adult POAG.

Anterior Chamber↗

PubMed1976

Physostigmine in tricyclic antidepressant overdose.

Acute accidental and suicidal overdosages are becoming common in emergency medicine. Physostigmine salicylate (Antilirium) is the only parasympathomimetic drug capable of reversing both the central and peripheral manifestations of the anticholinergic syndrome caused by overdosage of tricyclic antidepressant drugs. Physostigmine acts rapidly, within 5 to 20 minutes, dramatically reversing the toxic effects. Because of the short duration of action, intoxication may recur and repeated doses may be necessary. Four cases, successfully managed, are presented and the pertinent literature reviewed.

Adult↗

PubMed2002

In vitro neuropharmacological evaluation of piperovatine, an isobutylamide from Piper piscatorum (Piperaceae).

Piperovatine, a sialogogic, piscicidal, and buccal local anesthesia producing isobutyl amide from the amazonian piscicidal and toothache-relieving plant, Piper piscatorum Trelease et Yuncker (Piperaceae), was evaluated for its ability to induce changes in neuronal intracellular calcium concentration. Ratiometric calcium imaging of Periplaneta americana neuronal cell cultures upon piperovatine application revealed that this compound induced dramatic increases in intracellular calcium concentration. Calcium flux was not affected by co-application of the muscarinic acetylcholine receptor antagonist, atropine, indicating that the parasympathomimetic system was not involved in piperovatine's sialogogic actions. Calcium flux was, however, totally eliminated by co-application of the voltage-gated sodium channel blocker, tetrodotoxin (TTX). This, in conjunction with the repetitive calcium spikes observed in the assay and previous radioligand binding studies on the chemical class, strongly suggest that activation of voltage-gated sodium channels characterizes piperovatine's mode of action

Animals↗

PubMed2000

Cardiac beta-adrenoceptors in chronic uremia: studies in humans and rats.

OBJECTIVES: The purpose of this study was to elucidate whether cardiac beta-adrenergic effects may be blunted in patients on maintenance hemodialysis (HD) and may help to explain autonomic dysfunction. BACKGROUND: Patients on HD often suffer from autonomic dysfunction. METHODS: We investigated the cardiovascular response of five HD patients (age: 46.1+/-7.9 years) and six healthy volunteers (age: 48.2+/-7.5 years) to isoprenaline, pirenzepine and phenylephrine. For analysis of underlying mechanisms of beta-adrenoceptor hyporesponsiveness, six-week-old male Wistar rats were rendered uremic by 5/6-nephrectomy (n = 9; SNX) and were killed for removal of the heart after six to seven weeks. Sham-operated rats (n = 15) served as controls. RESULTS: In the patient study, isoprenaline (3.5, 7, 17, 35 ng/kg/min, i.v.) led to an increase in heart rate, and shortening of the heart rate corrected duration of the electromechanical systole (QS2c), both of which were significantly reduced in HD patients. Baroreflex sensitivity was significantly reduced in HD patients. The response to low parasympathomimetic doses of pirenzepine was unchanged. In the rat study, left ventricular strips were placed in an organ bath, electrically driven and exposed to isoprenaline (10(-11) to 10(-6) mol/liter). While pD2 values were unchanged, maximum effect at the highest concentration was significantly reduced in SNX rats. The response to carbachol was not altered, nor was the M2-cholinoceptor density. There was no difference in beta-adrenoceptor density, or in immunodetectable amount of Gs and Gi protein. Activation of adenylyl cyclase evoked by isoprenaline was significantly reduced in left ventricular membranes of SNX rats, whereas effects of 10 micromol/liter GTP, 10 mmol/liter NaF, 10 micromol/liter forskolin and 10 mmol/liter Mn2+ were not altered. CONCLUSIONS: Cardiac beta-adrenergic responses are blunted in chronic uremia due to reduced isoprenaline-dependent activation of adenylyl cyclase. This might be caused by an "uncoupling" of the receptor or by an inhibition of the receptor by uremic toxins.

Adenylyl Cyclases↗

PubMed2001

The muscarinic receptor agonist BuTAC, a novel potential antipsychotic, does not impair learning and memory in mouse passive avoidance.

(5R,6R)-6-(3-butylthio-1,2,5-thiadiazol-4-yl)-1-azabicyclo[3.2.1]octane) (BuTAC) is a novel, selective muscarinic receptor ligand with partial agonist mode of action at muscarinic M2 and M4 and antagonist mode of action at M1, M3 and M5 receptor subtypes in cloned cell lines. BuTAC exhibits functional dopamine receptor antagonism despite its lack of affinity for dopamine receptors, and parasympathomimetic effects in mice are produced only at doses well beyond the doses exhibiting the antipsychotic-like effects. In the present study we investigated the effects of BuTAC and the antipsychotic compounds clozapine, sertindole and olanzapine using one trial passive avoidance with mice as a model of learning and memory. Pharmacologically relevant doses of BuTAC and reference antipsychotics were identified, based on inhibition of apomorphine-induced climbing in mice as an assay measuring antidopaminergic potency. When ratios between the minimum effective dose (MED) for impairment of retention in passive avoidance and the MED for inhibition of apomorphine-induced climbing were calculated, BuTAC displayed a high ratio of >10, compared with clozapine (0.3), sertindole (3) and olanzapine (3). These data suggest that BuTAC is a potential novel antipsychotic which may have favourable effects on aspects of learning and memory.

Animals↗

PubMed1998

Modulation of serum testosterone and autonomic function through stimulation of the male human vomeronasal organ (VNO) with pregna-4,20-diene-3,6-dione.

In mammals, external chemosensory signals from conspecifics of the opposite sex acting on vomeronasal organ receptors can modulate the release of gonadotropins. There is developmental, anatomical and functional evidence showing that the human vomeronasal organ (VNO) has the characteristics of a chemosensory organ. We have been using naturally occurring human pheromones to serve as models for designing novel synthetic compounds that we call vomeropherins. In previous publications we reported that vomeropherin pregna-4,20-diene-3,6-dione (PDD) delivered to the VNO of normal female and male human volunteers significantly affected male subjects only, decreasing respiration and cardiac frequency, augmenting alpha brain waves, and significantly decreasing serum luteinizing hormone (LH) and follicle stimulating hormone (FSH). Results of the present work confirm that PDD produces a local dose-dependent effect in the male human VNO. This is followed by a mild parasympathomimetic effect characterized by 10% increase of vagal tone, together with decreased frequency of electrodermal activity events. Furthermore, PDD locally delivered to the male human VNO significantly decreases serum LH and testosterone (p < 0.01). The present results contribute additional evidence supporting the functionality of the human VNO and its repercussions in autonomic and psychophysiological functions, as well as in neuroendocrine secretions.

Dose-Response Relationship, Drug↗

PubMed2002

Secretion from submucosal salivary glands of the ferret in response to a cholinesterase inhibitor applied onto the oral mucosa.

Parasympathomimetics or cholinesterase inhibitors taken orally may relieve dry-mouth symptoms, but this route of administration is often associated with adverse systemic reactions. In the present study, an animal model was worked out aimed at stimulating the submucosal glands and avoiding systemic effects. In the anesthetized ferret, saliva from the parotid, sublingual and submandibular glands was prevented from reaching the mouth. Vehicle or physostigmine was applied topically for 10 min on the buccal and labial mucosa on one side, while the other side served as a control. Fluid from each side was collected every 5 min Mean basal secretion was 0.17 mg 5 min(-1). The response to physostigmine 0.1% did not exceed that of the vehicle. At higher concentrations the responses lasted 80-120 min. Peak secretion was nine (0.25% physostigmine), 13 (0.5% physostigmine) and 40 (1% physostigmine) times higher than baseline. At 1% physostigmine, the secretion from the control side was elevated, and a small flow from the duct-cannulated parotid gland occurred, indicating systemic effects. Arterial blood pressure was well maintained. Additional observations on the duct-cannulated zygomatic gland showed that secretion from this gland increased already within the 10-min period of application of physostigmine to the overlying mucosa. The distance between the mucosa and the zygomatic gland was only about 1 mm. Physostigmine-induced secretion was abolished by atropine. Local gland stimulation may be an attractive alternative for the treatment of dry mouth.

Administration, Buccal↗

PubMed1993

The effect of topical pilocarpine on pulsatile ocular blood flow.

Ocular blood flow is considered an important factor in determining the extent of visual damage occurring in primary open angle glaucoma (POAG). The effect of topical pilocarpine, a parasympathomimetic vasodilator, on the pulsatile ocular blood flow (POBF) in POAG subjects was studied. A pneumotonometer linked to the Langham Ocular Blood Flow System recorded the intraocular pressure (IOP) pulse from which POBF was calculated. Measurements were taken from 18 POAG subjects treated with both G pilocarpine and G timolol, 2 weeks after withdrawing G pilocarpine and again 1 week after reinstituting full treatment. Recordings from 20 POAG patients treated with only G timolol were taken as control values. There was no significant difference in the IOP or POBF between the controls and POAG patients on dual therapy. Furthermore when G pilocarpine was temporarily withdrawn there was no significant change in POBF despite a significant rise in IOP. The results imply that aqueous pilocarpine has no direct effect on the pulsatile component of ocular blood.

Administration, Topical↗

PubMed1975

The autonomic nervous system and the bladder during spinal shock--an experimental study.

During experimental spinal shock, the urethral muscle responded to drugs earlier than the detrusor muscle. Stimulation with parasympathomimetic drugs caused some rise in intravesical pressure, but an unexpected and much greater rise of intraurethral pressure. Bladder evacuation was achieved with the Credé manoeuvre during spinal shock with the combined effect of alpha adrenergic blockade and beta adrenergic stimulation.

Animals↗

PubMed1973

Biosynthesis of respiratory-tract mucins. A comparison of canine epithelial goblet-cell and submucosal-gland secretions.

1. A modified canine tracheal organ culture system was used to investigate differences between mucous secretions of epithelial goblet cells and the submucosal glands. 2. Denuded explants were prepared by removing goblet, ciliated and basal cells from the surface epithelium leaving an intact basement membrane and viable submucosa. 3. Denuded explants actively incorporated radioactive precursors into secreted macromolecules when cultured in medium 199 containing label. 4. Chromatography on Bio-Gel A-150m and electrophoresis on 1% agarose gels indicated that epithelial goblet cell secretions were relatively more sulphated than submucosal glandular secretions. 5. The glandular structures were shown to respond to a parasympathomimetic agent.

Animals↗

PubMed1982

Directional Ca2+ effect on stimulation of mucin secretion from chicken trachea in vitro.

Chicken tracheal mucosa in vitro transported and incorporated radioactive precursors into mucins, which were secreted at a steady rate into the tracheal lumen. Secretion of mucins labelled with (35)S and (3)H after pulse-labelling of the mucosal layer with Na(2) (35)SO(4) and d-[1-(3)H]glucosamine as precursors was an energy-dependent process, as it was strongly inhibited by the action of respiratory-chain inhibitors, an uncoupler of oxidative phosphorylation, a metabolic blocker and a temperature shift from 41 degrees C to 5 degrees C. On the other hand, both cholinergic and parasympathomimetic agents considerably increased the secretion of dual-radiolabelled mucins when applied on the submucosal side of the trachea. The effect of Ca(2+) was directional, since only high submucosal (3.6 or 18mm) or low luminal (zero or 0.18mm) Ca(2+) massively enhanced the secretion of radiolabelled mucin compared with the mucin output measured under physiological Ca(2+) conditions (1.8mm). Whereas application of ionophore A23187 on either side of the trachea significantly increased mucin output, its presence in the appropriate tracheal compartment and under appropriate Ca(2+) conditions further accentuated the output of radiolabelled mucins. Addition of acetylcholine under appropriate conditions also had an additive effect on the Ca(2+)-stimulated secretion of mucins. Ca(2+) stimulation of mucin secretion appears to be dependent on the metabolic integrity of the mucosal cells. Mucins secreted in response to high submucosal and low luminal [Ca(2+)] appear to consist of a number of different types of glycoproteins, as judged from their ion-exchange-chromatographic behaviour.

Animals↗

PubMed1998

Discharge patterns of intramural mechanoreceptive afferents during selective distension of the cat's rectum.

The afferent input from the rectum to the central nervous system (CNS) has yet to be thoroughly characterized. The characteristics of mechanoreceptive rectal afferents have been studied in unanaesthetized decerebrate cats. Following lumbo-sacral laminectomy, single-unit activity (occasionally multi-unit activity) was recorded from centrally cut filaments of the sacral dorsal roots (predominantly S2), while a balloon was inflated in the rectum. Starting from their background activities (mean 15.1 imp sec-1, SD 7.6 imp sec-1), afferent discharge rate increased with increasing balloon pressure (mean threshold 6.3 mmHg, SD 3.6 mmHg). The dependence of firing rate on intrarectal pressure began to flatten out at 25 mmHg (mean; SD 10 mmHg). For 22 out of 29 units (76%) complete saturation occurred at 35 mmHg (mean; SD 15 mmHg) with a maximum discharge rate of 31 imp sec-1 (mean; SD 12.6 imp sec-1). In a number of recording sessions, cyclical rectal contractions were observed. In these cases, changes in firing of the units were closely related to changes in intrarectal pressure. Pressure-related afferent activity could be enhanced by parasympathomimetic drugs which augmented rectal contractions. We conclude that sacral dorsal roots contain afferents from low-threshold mechanoreceptors located in the rectal wall, and that these afferents monitor the filling state and contraction level of the rectum.

Animals↗

PubMed1983

Quantification of salivation, nasal secretion and tearing in man.

The purpose of this study has been to establish a battery of tests of autonomic functions: Quantification of submandibular/sublingual salivation, nasal secretion and tearing on both sides. The tests were performed in a control group of 20 healthy students. We used a parasympathomimetic drug, pilocarpine 0.1 mg/kg body weight, to stimulate the different secretory functions. Saliva was collected with a pair of dentistry spiral suctions. Tearing was assessed with Schirmer's test tapes. Nasal secretion was quantified using Schirmer's test tapes, too. Nasal secretion and salivation on average was fairly symmetrical, whereas there was some asymmetry in tearing (which may be artificial). In single individuals, there may be considerable asymmetry in salivation as well. This test battery will be used in the study of possible autonomic dysfunctions in patients with unilateral headache.

Adolescent↗

PubMed2004

Vagal activity modulates spontaneous augmentation of ST elevation in the daily life of patients with Brugada syndrome.

INTRODUCTION: In Brugada syndrome, ventricular fibrillation (VF) occurs mainly during sleep, and Brugada ECG signs are intensified by parasympathomimetic drugs; therefore, vagal activity could be a precipitating factor of VF. The aim of the present study was to elucidate the relation between spontaneous augmentation of ST elevation and changes in autonomic nervous activities in the daily life of patients with Brugada syndrome. METHODS AND RESULTS: Twenty-three consecutive patients with Brugada syndrome were studied. Group VF(+) consisted of 7 symptomatic patients and 3 asymptomatic patients with inducible VF; group VF(-) consisted of 13 asymptomatic patients without documented or inducible VF. Two-channel unipolar lead (V(1) and V(2)) Holter ECG was recorded. Heart rate variability was analyzed by the maximum entropy method. Spontaneous augmentation of ST elevation (>/=1.5 mm/20 min) occurred more frequently during 24 hours in group VF(+) than in group VF(-) (5.7 +/- 2.5 times vs 2.3 +/- 2.4 times, P < 0.01). ST elevation was significantly greater in group VF(+) than in group VF(-) (2.1 +/- 0.2 mm vs 1.8 +/- 0.2 mm, P < 0.05). Power of the high-frequency component (HF: 0.15-0.4 Hz) and RR interval increased progressively, and the ratio of low-frequency component (LF; 0.04- 0.15 Hz) to high-frequency component (LF/HF) gradually decreased toward the time of maximum ST elevation. During an entire day, daytime (0-5 P.M.), and nighttime (0-5 A.M.), both HF and LF/HF were not different between groups VF(+) and VF(-). CONCLUSION: In Brugada syndrome, spontaneous augmentation of ST elevation in daily life occurred along with an increase in vagal activity. ST elevation was augmented more in patients with VF than in those without VF under similar vagal tone.

Adult↗

PubMed2001

Contact dermatitis to topical drugs for glaucoma.

A review of the literature has identified 10 agents causing contact dermatitis among topically administered drugs for glaucoma. These agents include beta-blockers (timolol, befunolol, betaxolol, levobunolol, carteolol, metipranolol), a carbonic anhydrase inhibitor (dorzolamide), a parasympathomimetic (pilocarpine), and sympathomimetics (dipivefrin, apraclonidine). Patch testing has been documented in certain individuals as well as cross sensitization and reactivity. Systemic reactions to these topically applied medications have been briefly noted.

Dermatitis, Allergic Contact↗

PubMed1988

[Postoperative disorder of bladder emptying in gynecology: pathophysiology and possibilities for treatment].

Urinary retention after radical hysterectomy is due to partial or complete denervation of the bladder and proximal urethra which is dependent on surgical radicality. In contrast, incomplete bladder emptying after surgery for stress induced urinary incontinence, has its origin in an infravesicular functional obstruction and is dependent on the operation performed. The use of drugs (alpha-sympatholytics, parasympathomimetics) seem to be of limited value, especially after stress-incontinence surgery. Preoperative information, perioperative supra pubic bladder drainage, postoperative bladder training and in rare cases intermittent self-catheterisation and transurethral surgery are the key factors in successful treatment of postoperative urinary retention.

Female↗

PubMed1988

[Demodex folliculorum].

The author reports on Demodex folliculorum ("hair follicle mite"), a frequent and widespread parasite. These mites are found in hair follicles of eyelashes in particular. In ophthalmology they are responsible for chronic eczematous blepharitis ("blepharitis acarica") with trichiasis and madarosis. Therapy is unsatisfactory. The author has now discovered that isoptocarbachol 3% eyedrops successfully combat Demodex folliculorum. The solution was first tested experimentally on house flies (Musca domestica) and was later used to treat patients affected with the parasite: a cotton bud impregnated with this parasympathomimetic (anticholinesterase) drug was applied to the border of the eyelids several times.

Adult↗

PubMed1981

[The effect of unintentional overdoses of pilocarpine on pulmonary surfactant in mice].

Pilocarpine, used in the treatment of glaucoma, shows basically parasympathomimetic activities and in contrast to choline derivatives an extremely potent effect on salivary and sweat glands and a noticeable increase of bronchial secretion. Investigations were carried out in mice to determine whether the administration of pilocarpine results in an increase of bronchial secretion as such or whether it likewise influences the secretion of surfactant, i.e., the phospholipoprotein responsible for the stability of the alveoli. Our experiments (P/V diagrams and histochemical staining) demonstrate that pilocarpine decreases the secretion of pulmonary surfactant. When pilocarpine and Ambroxol are administered the effects on the two parameters are similar to the controls. In other words, Ambroxol increases the secretion of surfactant even in cases of intoxication with pilocarpine.

Ambroxol↗