The Role of α7nAChR-Mediated Cholinergic Anti-inflammatory Pathway in Immune Cells

Alpha 7 nicotinic acetylcholine receptor (α7nAChR) is widely distributed in the nervous and non-cholinergic immune systems. It is necessary for the cholinergic transmitter to participate in the regulation of inflammatory response and is the key element of cholinergic anti-inflammatory pathway (CAP). Because of the profound impact of CAP on the immune system, α7nAChR is considered as a potential therapeutic target for the treatment of inflammatory diseases. Available evidences confirmed that manipulation of CAP by activating α7nAChR with either endogenous acetylcholine (ACh) or cholinergic agonists can substantially alleviate inflammatory responses both in vivo and in vitro. However, the mechanism through which CAP curbs the excessive pro-inflammatory responses and maintains immune homeostasis is not fully understood. Obtained clues suggest that the crosstalk between CAP and classical inflammatory pathways is the key to elucidate the anti-inflammatory mechanism, and the impacts of CAP activation in α7nAChR-expressing immune cells are the foundation of the immunoregulatory property. In this article, we review and update the knowledge concerning the progresses of α7nAChR-based CAP, including α7nAChR properties, signal transductions, interactions with classic immune pathways, and immunoregulatory functions in different immune cells. Certain critical issues to be addressed are also highlighted. By providing a panoramic view of α7nAChR, the summarized evidences will pave the way for the development of novel anti-inflammatory reagents and strategy and inspire further researches.

ICH3, a selective alpha7 nicotinic acetylcholine receptor agonist, modulates adipocyte inflammation associated with obesity

PURPOSE

The alpha7 nicotinic acetylcholine receptor (α7nAChR), involved in the modulation of inflammation and insulin sensitivity, is downregulated in white adipose tissue (WAT) of obese patients. This study aims to test the ability of a selective synthetic α7nAChR agonist, the spirocyclic Δ²-isoxazoline derivative (R)-(-)-ICH3 (ICH3), to counteract acute inflammation and obesity-associated modifications in WAT.

METHODS

We employed the LPS-septic shock murine model, human primary adipocytes and diet-induced obese (DIO) mice. Inflammatory factor expression was assessed by ELISA and quantitative real-time PCR. Flow cytometry was employed to define WAT inflammatory infiltrate. Insulin signaling was monitored by quantification of AKT phosphorylation.

RESULTS

In the septic shock model, ICH3 revealed antipyretic action and reduced the surge of circulating cytokines. In vitro, ICH3 stimulation (10 µM) preserved viability of human adipocytes, decreased IL-6 mRNA (P < 0.05) and blunted LPS-induced peak of TNFα (P < 0.05) and IL-6 (P < 0.01). Chronic administration of ICH3 to DIO mice was associated with lower numbers of CD8+ T cells (P < 0.05) and to changed WAT expression of inflammatory factors (Hp, P < 0.05; CD301/MGL1, P < 0.01; Arg-1, P < 0.05). As compared to untreated, ICH3 DIO mice exhibited improved insulin signaling in the skeletal muscle (P < 0.01) mirrored by an improved response to glucose load (ipGTT: P < 0.05 at 120 min).

CONCLUSIONS

We proved that ICH3 is an anti-inflammatory drug, able to reduce inflammatory cytokines in human adipocytes and to blunt the effects of obesity on WAT inflammatory profile, on glucose tolerance and on tissue insulin sensitivity.

Prescribing trends of glaucoma drugs in six major cities of China from 2013 to 2017

OBJECTIVE

To evaluate the prescribing trends of glaucoma drugs in six major cities of China from 2013 to 2017.

METHODS

A descriptive analysis using pharmacy prescription data was conducted. Outpatient prescription data was extracted from the Hospital Prescription Analysis Cooperative Project. Prescribing patterns, trends of visits, and corresponding expenditures for glaucoma medications were analyzed.

RESULTS

A total of 84297 ambulatory prescriptions were included in the current study. Visits by glaucoma patients increased from 13808 in 2013 to 20060 in 2017. Over the same period, the yearly expenditure for glaucoma drugs increased from 2.33 million to 3.95 million Chinese Yuan (CNY). Among all the six classes of glaucoma drugs (prostaglandin analogues, carbonic anhydrase inhibitors, α-receptor agonists, β-receptor antagonists, cholinergic agonists and fixed combinations), β-receptor antagonists were the most commonly prescribed in 2013, accounting for 34.3% of patients, but gradually decreased to 27.1% in 2017. Prostaglandin analogues became the most frequently prescribed drugs in 2017, accounting for 30.2% of the visits. Prostaglandin analogues are the most expensive and yielded a total expenditure of 2.34 million CNY in 2017, followed by carbonic anhydrase inhibitors, α-receptor agonists, β-receptor antagonists, fixed combinations, and cholinergic agonists. Combination therapy became increasingly prescribed in 2017.

CONCLUSION

Glaucoma prescribing practices exhibited substantial changes over the study period. The number of glaucoma prescriptions continuously increased from 2013 to 2017, leading to increased prescription costs. These findings implied a similar trend observed in previous studies, as well as recommendations in the appropriate guidelines.

Arecoline ameliorates hyperthyroid condition in mice under cold stress

Betel nut of Areca catechu is chewed by millions of people for increased capacity to work and stress reduction, but it contains arecoline that causes hypothyroidism. The aim is to investigate the role of arecoline on thyroid activity in cold stress in mice. Arecoline treatment (10 mg/kg body wt/day, for 7 d) caused a reduction in thyroid weight and ultrastructural degeneration of thyro-follicular cells with depletion of T₃ and T₄ levels compared with the control mice. Cold stress (4 °C for 2 h, twice daily, for 7 d) stimulated thyroid activity ultrastructurally with an elevation of T₃ and T₄ levels. Arecoline treatment in cold stress suppressed thyroid activity by showing reversed changes to those of cold stress. In contrast, TSH concentrations were consistently increased under all experimental conditions. The findings suggest that cold stress causes hyperthyroidism which arecoline can ameliorate in mice.

Revisiting the Cardioprotective Effects of Acetylcholine Receptor Activation against Myocardial Ischemia/Reperfusion Injury

Acute myocardial infarction (AMI) is the most common cause of acute myocardial injury and its most clinically significant form. The most effective treatment for AMI is to restore an adequate coronary blood flow to the ischemic myocardium as quickly as possible. However, reperfusion of an ischemic region can induce cardiomyocyte death, a phenomenon termed “myocardial ischemia/reperfusion (I/R) injury”. Disruption of cardiac parasympathetic (vagal) activity is a common hallmark of a variety of cardiovascular diseases including AMI. Experimental studies have shown that increased vagal activity exerts cardioprotective effects against myocardial I/R injury. In addition, acetylcholine (ACh), the principle cardiac vagal neurotransmitter, has been shown to replicate the cardioprotective effects of cardiac ischemic conditioning. Moreover, studies have shown that cardiomyocytes can synthesize and secrete ACh, which gives further evidence concerning the importance of the non-neuronal cholinergic signaling cascades. This suggests that the activation of ACh receptors is involved in cardioprotection against myocardial I/R injury. There are two types of ACh receptors (AChRs), namely muscarinic and nicotinic receptors (mAChRs and nAChRs, respectively). However, the effects of AChRs activation in cardioprotection during myocardial I/R are still not fully understood. In this review, we summarize the evidence suggesting the association between AChRs activation with both electrical and pharmacological interventions and the cardioprotection during myocardial I/R, as well as outline potential mechanisms underlying these cardioprotective effects.

Arecoline cannot alter testicular dysfunction and pineal activation caused by noise in wistar rat

Millions of people consume betel nut for increased capacity to work and for stress reduction. The nut contains arecoline, which has multiple side effects on endocrine functions. Objective of the work is to investigate pineal-testicular responses to noise and after arecoline treatment in noise in rats. Noise exposure (100 dB, 6 h daily, 10 days) caused pineal stimulation ultrastructurally and at indoleamines level. Leydig cell dysfunction with fall of testosterone level and suppression of sex accessories were noticed. In contrast, pineal activity was inhibited and reproductive functions were stimulated after arecoline administration, confirmed from reversed changes to those of noise. Arecoline treatment in noise exposure showed same results as in noise both in pineal and in reproductive functions. It is concluded that noise causes testicular dysfunction probably by gonadotropin suppression induced by pineal melatonin in noise. Furthermore, arecoline cannot prevent it in noise in rats.

[Endogenous Sensitizer of Beta-Adrenergic Receptors (ESBAR) as a Component of Humoral Links Element of Autonomic Nervous System and Its Analogs (Review)]

Kirov State Medical Academy, Kirov The results of the 20-years studies of the presence in blood serum and other body fluids of endogenous modulators of adrenergic and M-cholinergic impact a A COMPONENT of humoral element of autonomic nervous system. The article is devoted to the endogenous sensitizer of beta-adrenergic receptor (ESBAR) - water-soluble low molecular weight substances, analogues of which are histidine, tryptophan, tyrosine, mildronat and preduktal. It is shown, that separate dilutions of human serum and animal (as a source of ESBAR) and ESBAR - analogues ways to enhance the effectiveness of activation of beta-adrenoceptors (AR) of smooth muscle (uterus, coronary and renal arteries, trachea, stomach), myocardium and erythrocytes and platelets (respectively influenced of histidine and tryptophan). It is reported? that content of ESBAR in human serum (according to the titers of its dilution) depends on the sex and the presence of somatic diseases, and at women are also on the stage of reproduction and obstetric complications It is discussed hossible mechanisms of ESBAR action, its physiological role, including as a component of beta-adrenoreceptor myometrium inhibitory mechanism, as well as the prospect of the use of analogues ESBAR, including for the prevention of preterm labor, and for the treatment of bronchial asthma, coronary heart disease, hypertension and heart failure.

Glaucoma

Glaucoma is a set of irreversible, progressive optic neuropathies that can lead to severe visual field loss and blindness. The two most common forms of glaucoma, primary open-angle glaucoma and primary angle-closure glaucoma, affect more than 2 million Americans and are increasing in prevalence. Many patients with glaucoma are asymptomatic and do not know they have the disease. Risk factors for primary open-angle glaucoma include older age, black race, Hispanic origin, family history of glaucoma, and diabetes mellitus. Risk factors for primary angle-closure glaucoma include older age, Asian descent, and female sex. Advanced disease at initial presentation and treatment nonadherence put patients with glaucoma at risk of disease progression to blindness. The U.S. Preventive Services Task Force has concluded that the evidence is insufficient to assess the potential benefits and harms of screening for glaucoma in the primary care setting. Regular eye examinations for adults are recommended by the American Academy of Ophthalmology, with the interval depending on patient age and risk factors. Diagnosis of glaucoma requires careful optic nerve evaluation and functional studies assessing a patient's visual field. The goal of treatment with eye drops, laser therapy, or surgery is to slow visual field loss by lowering intraocular pressure. Family physicians can contribute to lowering morbidity from glaucoma through early identification of high-risk patients and by emphasizing treatment adherence in patients with glaucoma.

Congenital myasthenic syndromes: pathogenesis, diagnosis, and treatment

The congenital myasthenic syndromes (CMS) are a diverse group of genetic disorders caused by abnormal signal transmission at the motor endplate, a special synaptic contact between motor axons and each skeletal muscle fibre. Most CMS stem from molecular defects in the muscle nicotinic acetylcholine receptor, but they can also be caused by mutations in presynaptic proteins, mutations in proteins associated with the synaptic basal lamina, defects in endplate development and maintenance, or defects in protein glycosylation. The specific diagnosis of some CMS can sometimes be reached by phenotypic clues pointing to the mutated gene. In the absence of such clues, exome sequencing is a useful technique for finding the disease gene. Greater understanding of the mechanisms of CMS have been obtained from structural and electrophysiological studies of the endplate, and from biochemical studies. Present therapies for the CMS include cholinergic agonists, long-lived open-channel blockers of the acetylcholine receptor ion channel, and adrenergic agonists. Although most CMS are treatable, caution should be exercised as some drugs that are beneficial in one syndrome can be detrimental in another.

Repetitive administration of acetylcholine receptor agonist rescues brain inflammation and brain damage after hypoxia-ischemia in newborn rat

OBJECTIVE

We examined the effect of repetitive administration of acetylcholine receptor agonist (carbachol) on brain damage and microglial accumulation in three brain regions after hypoxia-ischemia (HI) in newborn rat.

STUDY DESIGN

Seven-day-old Wistar rats were divided into two groups, one receiving a 0.1 mg/kg dose of carbachol on days 7, 8 and 9 to examine the attenuating effect on brain damage with decreasing accumulation of microglia, and the other group receiving saline as a control. Rats were subjected to left carotid artery ligation followed by hypoxia. We evaluated brain damage and the number of microglias in three regions on days 10 and 14.

RESULTS

Brain tissue was better preserved in the carbachol group on days 10 and 14. Microglial accumulation in the cortex was strong and persisted from day 10s to 14 in the control. Conversely, the accumulation of microglias was attenuated in the hippocampus and white matter on day 14. Carbachol significantly reduced the number of microglias in the hippocampus and white matter on day 10 and in the cortex on days 10 and 14.

CONCLUSION

The main area of late inflammation was the cortex. Repetitive administration of carbachol reduces early and late inflammation after HI in the developing brain.

Intracameral acetylcholine effectively contracts pupils after dilatation with intracameral mydriatics

PURPOSE

To determine whether intracameral acetylcholine can contract pupils dilated with intracameral mydriatics in phacoemulsification cataract surgery.

METHODS

A total of 60 patients were included in this prospective randomized masked study performed at Örnsköldsviks Hospital Eye Clinic. The patients were randomized and were given either topical placebo and an intracameral mydriatic solution (ICM) (cyclopentolate 0.1%, phenylephrine 1.5% and xylocaine 1%) (n = 30) or topical mydriatics (TM) (cyclopentolate 0.85% and phenylephrine 1.5%) and xylocaine 1% intracamerally (n = 30) at the start of surgery. After intraocular lens (IOL) implantation, 0.15 ml 1% acetylcholine was given intracamerally in all cases. The pupil size was registered preoperatively, 45 seconds after intracameral injection, after ophthalmic viscosurgical device (OVD) evacuation, 30 seconds after acetylcholine injection, 2 min after acetylcholine injection and the day after surgery.

RESULTS

The pupil contraction and pupil size after acetylcholine injection showed no significant differences at 30 seconds (contraction 1.0 ± 0.4 in ICM group versus 0.9 ± 0.4 in TM group; p = 0.75; size 4.8 ± 1.1 in the ICM group versus 5.2 ± 1.1 in the TM group; p = 0.24) or at 2 min (contraction 1.5 ± 0.6 in the ICM group versus 1.4 ± 0.6 in the TM group; p = 0.63; size 4.3 ± 0.9 in the ICM group versus 4.7 ± 1.0 in the TM group; p = 0.13). No difference in baseline pupil size after ophthalmic viscosurgical device (OVD) evacuation was seen between the two groups (5.8 ± 0.9 in the ICM group versus 6.1 ± 1.2 in the TM group; p = 0.28).

CONCLUSION

We here show that intracameral acetylcholine contracts pupils as effectively after dilatation with intracameral mydriatics as after dilatation with topical mydriatics. Cataract surgeons can feel comfortable and safe when using intracameral mydriatics, even if pupil contraction with acetylcholine should be required.

Salivary gland and associated complications in head and neck cancer therapy

Xerostomia and salivary gland hypofunction are two of the most common and significant complications of head and neck cancer therapy in the head and neck region. This article will provide a brief overview of salivary gland hypofunction and associated complications in head and neck cancer therapy, mainly in radiation therapy. The discussion will include quality of life issues as well as current advances in cancer therapy to reduce xerostomia and salivary gland hypofunction.

Xerostomia. Diagnosis and management in dental practice

Xerostomia is a subjective sensation of oral dryness. It is caused by many factors, among them, hypo/hyper salivation. This article covers the etiology, local and systemic factors related to dryness of the mouth, its diagnosis, and clinical and at-home management of the syndrome. It also reviews the role of dental hygiene intervention to improve and promote the patient's quality of life. It is hoped this review will help dental health care providers better respond to patients afflicted with xerostomia.

Myasthenic syndrome due to defects in rapsyn: Clinical and molecular findings in 39 patients

BACKGROUND

Pathogenic mutations in rapsyn result in endplate acetylcholine receptor (AChR) deficiency and are a common cause of postsynaptic congenital myasthenic syndromes.

METHODS

Clinical, electrophysiologic, pathologic, and molecular studies were done in 39 patients.

RESULTS

In all but one patient, the disease presented in the first 2 years of life. In 9 patients, the myasthenic symptoms included constant or episodic ophthalmoparesis, and 1 patient had a pure limb-girdle phenotype. More than one-half of the patients experienced intermittent exacerbations. Long-term follow-up was available in 25 patients after start of cholinergic therapy: 21 became stable or were improved and 2 of these became asymptomatic; 3 had a progressive course; and 1 died in infancy. In 7 patients who had endplate studies, the average counts of AChR per endplate and the synaptic response to ACh were less reduced than in patients harboring low AChR expressor mutations. Eight patients were homozygous and 23 heterozygous for the common p.N88K mutation. Six mutations, comprising 3 missense mutations, an in-frame deletion, a splice-site mutation, and a nonsense mutation, are novel. Homozygosity for p.N88K was associated with varying grades of severity. No genotype-phenotype correlations were observed except in 8 Near-Eastern patients homozygous for the promoter mutation (c.-38A>G), who had a mild course.

CONCLUSIONS

All but 1 patient presented early in life and most responded to cholinergic agonists. With early diagnosis and therapy, rapsyn deficiency has a benign course in most patients. There was no consistent phenotype-genotype correlation except for an E-box mutation associated with jaw deformities.

Seeking approval: present and future therapies for pemphigus vulgaris

Pemphigus vulgaris is an autoimmune blistering disease of the skin and mucous membranes. Despite the potentially fatal prognosis, there are currently no FDA-approved treatments specifically for pemphigus. In 2006, the FDA designated orphan drug status to mycophenolate mofetil for the treatment of pemphigus vulgaris, indicating both federal and commercial interest in developing therapies for this devastating disease. This review focuses on pemphigus therapies that are currently in preclinical or clinical trials, as well as potential novel therapies based on recent advances in the understanding of the pathophysiology of this disease.

Xerostomia: the "invisible" oral health condition

Xerostomia, or dry mouth, is perhaps one of the most underappreciated, underdiagnosed, and undermanaged oral health conditions. Recognition of a xerostomic condition is important because it can significantly affect the overall quality of life and contribute to diminishing oral health in a number of ways. This article will provide an overview of the etiology of xerostomia, the sequelae of the condition, and suggestions for pharmacological and nonpharmacological management of the condition to improve a patient's quality of life.

Pharmacological enhancement of cognitive and behavioral deficits after traumatic brain injury

PURPOSE OF REVIEW

To provide the clinician with a reasonable overview of the modern pharmacological alternatives to treat the cognitive and behavioral sequels of traumatic brain injury.

RECENT FINDINGS

Original research in this area is sparse and more than half of the articles published on the subject recently have been reviews. Of the three randomized controlled trials, one studied methylphenidate (n = 18), one methylphenidate and sertraline (n = 30) and one amantadine (n = 27). All these studies reported beneficial effects on various cognitive measures, but because of the study protocols, the evidence provided may be questioned. The various reviews, uncontrolled studies and case reports suggest that at least psychostimulants, cholinergic agents, dopaminergic agents and antidepressants may be beneficial in treating the cognitive and behavioral symptoms of traumatic brain injury.

SUMMARY

The clinician trying to ameliorate the cognitive and behavioral symptoms of traumatic brain injury has to make decisions about pharmacotherapy that are still based mainly on clinical experience. Large randomized controlled trials giving high-quality evidence are so far missing. This review discusses the problems facing both the clinician and the scientist treating the cognitive and behavioral sequels of traumatic brain injury. A symptom-based approach is suggested for current practice.

Incomplete emptying and urinary retention in multiple-system atrophy: When does it occur and how do we manage it?

Neurogenic urinary retention can be a major cause of morbidity in multiple-system atrophy (MSA). However, the timing of its appearance has not been entirely clear, and neither have the medical and surgical modalities for managing patients. We present the data obtained from our uroneurological assessment and therapeutic interventions at various stages of MSA. We recruited 245 patients with probable MSA. We measured postvoid residuals (PVR) and performed EMG cystometry in all patients. The grand average volume of PVR was 140 mL (range, 0-760) in our patients. The average PVR volume was 71 mL in the first year, increasing to 129 mL in the second year and 170 mL by the fifth year. The percentages of patients with complete urinary retention, acontractile detrusor, and detrusor-sphincter dyssynergia (DSD) also increased. The increase in PVR resulted in a decrease in functional bladder capacity, together with an increase in detrusor overactivity and neurogenic sphincter EMG. Clean intermittent self-catheterization (CISC) was introduced in most patients. Bladder-oriented therapy (cholinergic agents) had a limited value, whereas urethra-oriented therapy benefited patients with DSD (surgery) for up to 2 years, but syncope occurred in a subset of patients (alpha-blockers). MSA patients present with large PVR by the second year of illness, and that large PVR secondarily causes urinary frequency. CISC is the recommended treatment for most patients. Urethra-oriented medication and surgery benefit patients who would have difficulty performing CISC, although careful consideration of the short-term efficacy and potential adverse effects of these alternatives is mandatory.

Glaucoma Medications

As with many diseases, glaucoma increases in frequency in older populations, and is very often encountered in patients taking multiple medications. While the exact mechanism of glaucomatous optic neuropathy (GON) is not known, intraocular pressure (IOP) is thought to be central to the process, and reducing IOP is the only known effective treatment. The newer definition of glaucoma is an IOP-sensitive optic neuropathy. While large, controlled studies have indicated that reducing IOP will slow the progression of disease, the contributions of other conditions and medications have not been adequately studied. As the adverse effect profiles of medical therapies for glaucoma have improved, use of these agents has increased greatly. This has resulted in a large number of older patients taking glaucoma medications. Since topical medications can easily be overlooked in a medical history, and are for the most part well tolerated, systemic complications from these agents can be missed. In addition to being a common disease requiring treatment, glaucoma is also a model system for other degenerative diseases, and many of the concepts originally developed in relation to neurodegenerative diseases such as Alzheimer's disease are under investigation for glaucoma. These include approaches targeted towards neuroprotection and excitotoxicity.

[Medical therapy of primitive hypertensive glaucoma-therapeutic principles, perspectives]

The present-day glaucoma therapy is aiming to preserve visual function by decreasing the intraocular pressure below a certain level, that prevents the optic nerve damage to occur. The target IOP must be individualized, considering the IOP level at presentation, the severity of the optic nerve damage, life expectancy and associated risk factors. In order to prevent the glaucoma progression, the more serious the damages are at presentation, the lower the target IOP level must be. New ocular hypotensive agents that have been created during the last few years allowed a more efficient control of the glaucoma progression.

Pharmacological advancements in the treatment of chronic anal fissure

Chronic anal fissure is a tear in the lining of the anal canal that, if not treated appropriately at an early stage, causes considerable anal pain during defaecation. Surgery is no longer considered the first-line treatment of this common condition, as recent advancements in medical treatment has produced promising results in the healing of fissures, thus avoiding the unwanted complications that frequently occur following operative treatment. This review looks at those pharmacological agents used commonly in the treatment of chronic anal fissures and explores alternative therapies that may be of benefit in the future.

Management of glaucoma: focus on pharmacological therapy

Glaucoma represents a major cause of vision loss throughout the world. Primary open-angle glaucoma, the most common form of glaucoma, is a chronic, progressive disease often, though not always, accompanied by elevated intraocular pressure (IOP). In this disorder, retinal ganglion cell loss and excavation of the optic nerve head produce characteristic peripheral visual field deficits. Patients with normal-tension glaucoma present with typical visual field and optic nerve head changes, without a documented history of elevated IOP. A variety of secondary causes, such as pigment dispersion syndrome and ocular trauma, can result in glaucoma as well. Treatment of all forms of glaucoma consists of reducing IOP. With proper treatment, progression of this disease can often be delayed or prevented. Treatment options for glaucoma include medications, laser therapy and incisional surgery. Laser techniques for the reduction of IOP include argon laser trabeculoplasty and selective laser trabeculoplasty. Both techniques work by increasing outflow of aqueous humour through the trabecular meshwork. Surgical options for glaucoma treatment include trabeculectomy, glaucoma drainage tube implantation and ciliary body cyclodestruction. While each of these types of procedures is effective at lowering IOP, therapy usually begins with medications. Medications lower IOP either by reducing the production or by increasing the rate of outflow of aqueous humour within the eye. Currently, there are five major classes of drugs used for the treatment of glaucoma: (i) cholinergics (acetylcholine receptor agonists); (ii) adrenoceptor agonists; (iii) carbonic anhydrase inhibitors (CAIs); (iv) beta-adrenoceptor antagonists; and (v) prostaglandin analogues (PGAs). Treatment typically begins with the selection of an agent for IOP reduction. Although beta-adrenoceptor antagonists are still commonly used by many clinicians, the PGAs are playing an increasingly important role in the first-line therapy of glaucoma. Adjunctive agents, such as alpha-adrenoceptor agonists and CAIs are often effective at providing additional reduction in IOP for patients not controlled on monotherapy. As with any chronic disease, effective treatment depends on minimising the adverse effects of therapy and maximising patient compliance. The introduction of a variety of well tolerated and potent medications over the past few years now allows the clinician to choose a treatment regimen on an individual patient basis and thereby treat this disorder more effectively.

Pathophysiology and management of radiation-induced xerostomia

Radiotherapeutic treatment of head and neck cancer patients often causes long-term dysfunction involving their salivary function, swallowing capabilities, and taste. Salivary gland dysfunction from radiation therapy is often the most unpleasant side effect of treatment. This article will review current knowledge concerning the anatomy and function of glands involved with salivation, measurement of salivary gland function, surgical and pharmacologic prevention and treatment of xerostomia, and methods to administer radiation while causing the least amount of damage to salivary glands.

Lack of effect of Helicobacter pylori on symptom improvement with a prokinetic medication, cisapride, in patients with non-ulcer dyspepsia

OBJECTIVE

This study was undertaken to determine whether H. pylori infection has an effect on the improvement of dyspeptic symptoms in response to a prokinetic agent, cisapride, in patients with non-ulcer dyspepsia (NUD).

MATERIAL AND METHOD

35 NUD patients (16 M, 19 F) who had no underlying medical condition and negative upper endoscopy were included in the present study. Each patient received a 2-wk treatment of cisapride (Prepulsid, 10 mg, tid ac). H. pylori infection was determined using a rapid urease test (CLO test). Gastric emptying (GE) scintigraphy and dyspeptic symptom scores were evaluated before and at the end of the treatment. GE was evaluated in 22 healthy volunteers as normal controls.

RESULTS

Half time (T1/2) GE of NUD patients was 90.9 +/- 28 min which was significantly longer than controls (77.6 +/- 14 min; p < 0.05) and was shortened to 73.6 +/- 22 min (p < 0.0001) at the end of the treatment. Cisapride significantly improved total dyspeptic symptom scores [7 (2-18) to 3 (0-11), p < 0.0001]. The symptom score improvement was not affected by H. pylori infection [H. pylori positive: 6 (2-18) to 2.5 (0-9), p < 0.0001; H. pylori negative: 9 (4-16) to 3 (0-11), p < 0.0001] or GE status [delayed GE: 10 (5-16) to 3 (15), p < 0.05; non delayed GE: 6 (2-18) to 2 (0-11); p < 0.0001].

CONCLUSIONS

Cisapride improves dyspeptic symptoms regardless of H. pylori and GE status. These results suggest that gastric emptying and H. pylori infection are not essential to determine prior to prescribing a prokinetic agent, cisapride, in patients with NUD.

Islet adaptation to insulin resistance: mechanisms and implications for intervention

Insulin sensitivity and insulin secretion are reciprocally related such that insulin resistance is adapted by increased insulin secretion to maintain normal glucose and lipid homeostasis. The relation between insulin sensitivity and secretion is curvilinear and mathematically best described as a hyperbolic relation. Several potential mediators have been suggested to be signals for the beta cells to respond to insulin resistance such as glucose, free fatty acids, autonomic nerves, fat-derived hormones and the gut hormone glucagon-like peptide-1 (GLP-1). Failure of these signals or of the pancreatic beta cells to adequately adapt insulin secretion in relation to insulin sensitivity results in inappropriate insulin levels, impaired glucose intolerance (IGT) and type 2 diabetes. Therefore, treatment of IGT and type 2 diabetes should aim at restoring the normal relation between insulin sensitivity and secretion. Such treatment includes stimulation of insulin secretion (sulphonylureas, repaglinide and nateglinide) and insulin sensitivity (metformin and thiazolidinediones), as well as treatment aimed at supporting the signals mediating the islet adaptation (cholinergic agonists and GLP-1). Both, for correct understanding of diabetes pathophysiology and for development of novel treatment modalities, therefore, the non-linear inverse relation between insulin sensitivity and secretion needs to be acknowledged.

Field evaluation of a coproantigen enzyme-linked immunosorbent assay for diagnosis of canine echinococcosis in a rural Andean village in Peru

One hundred and six dogs (61 males and 45 females) were examined for Echinococcus granulosus infection in a farming cooperative in the central highlands of Peru during November 1998. Canine echinococcosis was diagnosed using direct microscopic examinations of purged feces following arecoline purging and a coproantigen-detection enzyme-linked immunosorbent assay (ELISA) for E. granulosus. Mean age was 2 years with a range of 3 months to 9 years. The overall prevalence of canine echinococcosis using the ELISA test was 79% (84/106). Seventy-four dogs were successfully purged with arecoline. The frequency of canine echinococcosis was 82 (61/74) and 34% (25/74) by the coproantigen ELISA test and arecoline purging, respectively. The sensitivity and specificity of the coproantigen ELISA test was 88 and 95%, respectively. We found this assay to be especially advantageous in remote geographical areas. In future control programs against echinococcosis in Peru and other areas where E. granulosus is endemic the coproantigen ELISA should be used for the surveillance of the dog population.

Sjögren's syndrome

Saliva is an essential body fluid. It is important in maintaining oral health, taste acuity, mastication, deglutition and digestion, oral flora regulation, oral cleansing, voice acuity, and speech articulation. Saliva is composed largely of water but also contains minerals, electrolytes, buffers, enzymes, growth factors, cytokines, immunoglobulins, proteins, and metabolic waste products, with the concentrations and compositions of these components varying by individual. Many systemic disorders can affect salivary function, greatly compromising oral health. One such disorder is Sjögren's Syndrome (SS), an autoimmune exocrinopathy characterized by oral and ocular dryness with or without impairment of other organ systems. SS can cause substantial serologic autoimmune reactivity and in some instances is associated with other connective-tissue autoimmune disorders, such as rheumatoid arthritis, scleroderma, or systemic lupus erythematosus. SS increases the risk for developing malignant non-Hodgkin's lymphoma. Treatment of this syndrome consists of a combination of multiple agents, depending on the degree of symptomatology: cholinergic agonists, artificial salivary substitutes, nonsteroidal anti-inflammatory agents, antirheumatic drugs, and biologic agents. This article describes saliva and salivary function, the pathogenesis of SS, the current treatment of xerostomia, and quality of life issues related to salivary dysfunction.

[Treatment of Alzheimer's disease]

OBJECTIVE

To review the experience of the last twenty years in the treatment of Alzheimer s disease (AD).

METHODS

Literature review.

RESULTS

The neuropathological bases of AD are centered on two important pathophysiological mechanisms: 1) Structural damage (e.g., senile plaques, neurofibrillary tangles, neuronal loss, inflammatory processes), and 2) Loss of cholinergic neurons (and acetylcholine depletion) in the nucleus basalis of Meynert, which sends cholinergic projections to all areas of the neocortex, especially the temporal lobes and frontal and parietal association areas. The indemnity of this system is essential for normal cognitive functioning. At this moment, the only long term treatment available for AD are acetylcholinesterase inhibitors (CEIs) (e.g., tacrine, donepezil, rivastigmine, galanthamine). There are being investigated several treatments that may alter the development of neurofibrillary tangles and neuritic plaques (e.g., peripherally administered antibodies against beta amyloid proteins). Nerve growth factors may have the capability of improving neuronal survival, although their form of administration remains a problem. Amelioration of oxidative stress and CNS inflammatory processes may slow dawn the rate of neurodegeneration.

CONCLUSION

All suspected mechanisms of the metabolic cascade of AD have been explored with specific and non specific treatments. Current treatments (e.g., CEIs) still have to prove that their effects can last for long periods of time. With the advent of further understanding of the neurodegenerative processes that cause AD, new treatments that may slow down the progression of the disease will be available.

Cholinergic agonists and the treatment of Alzheimer's disease

Over the past decade, considerable effort was focused on the development of muscarinic and nicotinic agonists for the treatment of Alzheimer's disease. The rationale for developing muscarinic agonists was based on the role of acetylcholine in learning and memory function and the consistent neurochemical finding that cholinergic neurons degenerated in Alzheimer's patients. Thus far, the clinical utility of muscarinic agonists remains unproven, yet recent studies suggest that muscarinic agonists might be useful in treating not only memory deficits, but also psychiatric disturbances and some of the underlying causes of Alzheimer's disease, such as the deposition of Abeta. In addition, nicotinic receptors may play a role in cognitive function and help regulate the toxicity of amyloid precursor protein. Ultimately, cholinergic agonists may prove useful in the treatment of Alzheimer's disease.

Treatment of cognitive dysfunction associated with Alzheimer's disease with cholinergic precursors. Ineffective treatments or inappropriate approaches?

The observations of the loss of cholinergic function in neocortex and hippocampus in Alzheimer's disease (AD) developed the hypothesis that replacement of cholinergic function may be of therapeutic benefit to AD patients. The different approaches proposed or tested included intervention with acetylcholine (ACh) precursors, stimulation of ACh release, use of muscarinic or nicotinic receptor agonists and acetylcholinesterase (AChE) or cholinesterase (ChE) inhibition. Inhibition of endogenous ACh degradation through ChE inhibitors and precursor loading were treatments more largely investigated in clinical trials. Of the numerous compounds in development for the treatment of AD, AChE and ChE inhibitors are the most clinically advanced, although clinical trials conducted to date did not always confirm a significant benefit of these drugs on all symptom domains of AD. The first attempts in the treatment of AD with cholinergic precursors did not confirm a clinical utility of this class of compounds in well controlled clinical trials. However, cholinergic precursors most largely used such as choline and phosphatidylcholine (lecithin) were probably not suitable for enhancing brain levels of ACh. Other phospholipids involved in choline biosynthetic pathways such as CDP-choline, choline alphoscerate and phosphatidylserine clearly enhanced ACh availability or release and provided a modest improvement of cognitive dysfunction in AD, these effects being more pronounced with choline alphoscerate. Although some positive results cannot be generalized due to the small numbers of patients studied, they probably would justify reconsideration of the most promising molecules in larger carefully controlled trials.

Salivary gland dysfunction: a review of systemic therapies

Xerostomia may result from salivary dysfunction secondary to a variety of conditions, including medications, autoimmune disease, and tumoricidal therapy. As the geriatric population increases, the incidence of xerostomia will increase and the oral manifestations will continue to be a challenge to the clinician. Common oral manifestations resulting from decreased salivary flow include increased dental caries, fungal infections, and dysphagia. Treatment for salivary gland dysfunction is currently limited because of a lack of controlled clinical trials. Medications that have been studied in clinical trials are emphasized in this article. The aim of this article is to briefly review salivary gland physiology and to summarize the suggested systemic treatment modalities for xerostomia that emphasize controlled clinical trials.

Therapeutic potential of prostaglandin analogues in glaucoma

One of the most recent contributions to the therapeutic arsenal available for the treatment of glaucoma is the prostaglandin (PG) analogues. They represent a new class of ocular hypotensive drugs, targeting the uveoscleral outflow of ocular aqueous humour. Two drugs, latanoprost and unoprostone, are presently commercially available. In terms of intraocular pressure (IOP) reduction, latanoprost is the most powerful drug in clinical use today. The once daily dosing promotes compliance. Additional effect is achieved in combination with other hypotensive drugs, including those that increase trabecular outflow facility. The most frequent side effect is increased iris pigmentation that seems to be irreversible. A low frequency of cystoid macular oedema has been reported, predominantly in patients whose blood-retinal barrier (BRB) is compromised. Systemic side effects are rare. The experience with unoprostone is still much less than that with latanoprost. The ocular hypotensive mechanism of action of unoprostone is not well documented but an increase in uveoscleral outflow may be at least a part of its mode of action. Systemic side effects are rare and the ocular side effects seem to be mild. The ocular hypotensive effect is less than that of latanoprost and may not be suitable for monotherapy. It is widely accepted that the IOP alone is not responsible for the development of glaucomatous visual defects. It remains to be seen if this class of drugs will preserve vision in glaucoma patients better than other classes. More PG analogues are under development for potential clinical use.

Effects of chewing betel nut (Areca catechu) on the symptoms of people with schizophrenia in Palau, Micronesia

BACKGROUND

Although millions of people with schizophrenia live in betel chewing regions, the effects of betel chewing on their symptoms are unknown. Betel nut alkaloids include potent muscarinic cholinomimetics: recent research suggests that these agents may be therapeutic in schizophrenia.

AIMS

To compare the primary and extrapyramidal symptom profiles and substance-using habits of betel chewing v. non-chewing people with schizophrenia.

METHOD

A cross-sectional study of 70 people with schizophrenia. Symptom ratings measured by the Positive and Negative Syndrome Scale (PANSS) and Extrapyramidal Symptom Rating Scale (ESRS), and demographic and substance-use data, were compared for 40 chewers and 30 non-chewers of betel nut.

RESULTS

Betel chewers with schizophrenia scored significantly lower on the positive (P = 0.001) and negative (P = 0.002) sub-scales of the PANSS than did non-chewers. There were no significant differences in extrapyramidal symptoms or tardive dyskinesia.

CONCLUSIONS

Betel chewing is associated with milder symptomatology and avoidance of more harmful recreational drugs. These initial results indicate that longitudinal research is merited.

Impaired endothelium-dependent vasodilatation in uraemia

BACKGROUND

Patients with chronic renal failure (CRF) have a substantially increased risk of cardiovascular death, the proposed mechanisms being arrhythmias (left ventricular hypertrophy) and accelerated atherosclerosis. The vascular endothelium protects against the development of atherosclerosis principally by releasing vasoactive substances such as nitric oxide (NO) and endothelium-derived hyperpolarizing factor. In CRF there is accumulation of endogenous inhibitors of NO synthesis. In this present study we assessed endothelium-dependent vasodilatation in patients with advanced uraemia.

METHODS

Sixteen uraemic patients (pre-dialysis and continuous ambulatory peritoneal dialysis) and 18 controls were studied. Forearm plethysmography was used to measure forearm blood flow and the changes induced by carbachol (endothelium-dependent vasodilator) and sodium nitroprusside (SNP; endothelium-independent vasodilator). The order of drugs infused was randomized between subjects. Dose response curves were constructed for each agent and area under the curve (AUC) calculated (arbitrary units).

RESULTS

Overall, vasodilatation to SNP and carbachol was similar between uraemic patients and controls. However, it became apparent that there was a marked order effect for the drugs infused, such that infusion of SNP as the first agent blunted the subsequent response to carbachol. When only those patients and controls who received carbachol followed by SNP were studied (10 in each group), the response to carbachol in uraemic patients was attenuated compared to controls: AUC (median(range)) for uraemic patients 529.0 (150.9-834.7) compared to AUC for controls 703.9 (583.5-1576.6); P=0. 028. Vasodilatation to SNP was, however, similar between groups: AUC for uraemic patients 1475.0 (857.8-4717.1) compared to AUC for controls 1328.1 (216.6-3311.4); P=0.545.

CONCLUSIONS

This study has demonstrated a marked drug order effect not previously described for forearm plethysmography. When the order effect was taken into account, this study demonstrated reduced vasodilatation to carbachol in uraemic patients with a preserved response to SNP. This pattern indicates impaired endothelium-dependent vasodilatation in uraemic patients, a defect that may predispose this group to accelerated atherosclerosis.

The Lewy body variant of Alzheimer's disease: clinical, pathophysiological and conceptual issues

In 1923, Friedrich H. Lewy described dementia with Lewy bodies in a large proportion of his patients with paralysis agitans which had co-incident plaques and neurofibrillary tangles. The potential contribution of Lewy bodies to a dementia syndrome with fluctuating course, visual hallucinations, Parkinsonian features and neuroleptic hypersensitivity was rediscovered many decades later. The comorbidity of Alzheimer's and Parkinson's disease is not uncommon as both diseases show an exponential increase with advancing age and their coincidence is of great clinical importance. The combination of a cholinergic deficit--which is particularly severe due to the double pathology targeting the basal nucleus of Meynert--and a dopaminergic deficit requires cholinergic and cautious dopaminergic treatment. Excessive dopamine (L-dopa), antidopaminergic (neuroleptic) or anticholinergic treatment (anti-Parkinson or neuroleptic medication) may further complicate the condition, worsen extrapyramidal, psychotic or cognitive disturbances and even lead to a neuroleptic malignant syndrome.

Alzheimer's disease: past, present, and future

As we look to a world where more individuals will suffer from dementia, it is important to reflect on our past accomplishments as we work to create a better future. Attempts to develop better medications for Alzheimer's disease focus on symptomatic treatments for both cognitive and behavioral symptoms. Some progress has been made in the areas through use of cholinesterase inhibitors and novel neuroleptics. Quality of life is a central concept to improving our interventions and to developing more effective treatments based on our understanding of pathogenesis. In the past, almost hundred years since the pioneering work in Emil Kraepelin's laboratory that we are celebrating in this series of papers, we have come far but we have further to go.

Ambulatory urodynamics: do they help clinical management?

OBJECTIVE

To assess the contribution of ambulatory urodynamics to the treatment of women with urinary incontinence.

DESIGN

A retrospective casenote review of all women referred from the urogynaecology clinic for ambulatory urodynamic monitoring from 1 April 1994 to 31 December 1997.

SETTING

A teaching hospital tertiary referral centre urodynamic laboratory.

PARTICIPANTS

Notes were retrieved of 71 women, 80% of whom had had the investigation because the conventional cystometrogram had been normal.

RESULTS

Technical difficulties occurred in 30 traces, two of which were not interpretable. Detrusor instability was diagnosed in 32 women, including three women who also had stress incontinence (42% of interpretable traces). Of these, 20 women were treated with anticholinergics compared with nine of 37 women where detrusor instability was not diagnosed. None of the women with detrusor instability were offered anti-incontinence surgery, compared with five of those where the bladder remained stable. Less than half the women who were treated with anticholinergic medication improved, but none were considered suitable for more aggressive treatment.

CONCLUSIONS

Although the diagnosis of detrusor instability may be increased by ambulatory urodynamics, this does not always translate into more effective treatment. Ambulatory urodynamic testing does not yet result in clinical improvements in diagnosis and treatment.

Canine echinococcosis: an alternative for surveillance epidemiology

The essential activities for programmes of cystic echinococcosis control are the census of all dogs from the program and identification of parasitised animals. Currently, in South America evaluations and epidemiological surveillance are based on the administration of arecoline hydrobromide. This method has the disadvantage of increasing environmental pollution and risk for operators and owners of treated dogs. A genus-specific ELISA capture method has been employed for recently issued faeces and the confirmation of positive examination was performed by dog autopsies. Our work presents an alternative method based on collection of dry field-dispersed faeces, followed by serological diagnosis by Copro-ELISA and confirmation by Copro-Western blot. If Copro-ELISA were used to define positive samples of dry faeces, the Copro-Western blot assay would provide 70% sensitivity and 100% specificity. Global efficiency of the system using dry faeces would reach 76%, allowing epidemiological surveillance to be oriented to analysis of surface units instead of dog as measurement unit.

Transtympanic pilocarpine in tinnitus

In 48 patients who had neurosensory hypoacusia and whose main complaint was tinnitus, a 1% pilocarpine solution or a 2% carbachol Isopto solution was placed in the tympanic cavity by means of a No. 26 pencil-tipped lumbar puncture needle through the front quadrant of the eardrum. Patients were chosen without regard for age, gender, or topographical damage of the acoustic pathway. Evaluation of the drug's effect was performed audiometrically by masking with the minimum intensity of the pure sound or narrow band that most closely resembled the patients' own noises. The results of this medical therapy were positive and ranged from complete annulment to attenuation of the tinnitus, which was confirmed by audiometric masking 30 minutes after the intratympanic injection. These positive results reached 50% and would have been higher if the several cases submitted by accident insurance companies and cases of presbyacusia were discarded. The unsatisfactory element of the study was the short-term effect of the therapy, which usually lasted no more than 12-72 hours. Tinnitus reappeared in all patients at its original intensity. The best results involved the use of carbachol as compared with pilocarpine. The decision to replace pilocarpine with carbachol was based on the idea that the inhibitory cholinergic efferent pathways are damaged before the afferent pathways. The use of pilocarpine depends on efficient cholinergic functioning, as its activity is as an indirect agonist (i.e., to annul the cholinesterase enzyme).

A pilot controlled clinical trial of ABT-418, a cholinergic agonist, in the treatment of adults with attention deficit hyperactivity disorder

OBJECTIVE

Despite the increasing recognition of attention deficit hyperactivity disorder (ADHD) in adults, there is a paucity of controlled pharmacological trials. Recent reports have suggested the potential usefulness of cholinergic agents for ADHD. To this end, the authors completed a controlled study of ABT-418, a novel cholinergic activating agent, for the treatment of adults with ADHD.

METHOD

This was a double-blind, placebo-controlled, randomized, crossover trial that compared a transdermal patch of ABT-418 (75 mg/day) to placebo in adults who met DSM-IV criteria for ADHD. There were two 3-week treatment periods separated by 1 week of washout.

RESULTS

Of the 32 subjects enrolled in the study (88% were men; mean age = 40 years, SD = 9), 29 completed the study. At the endpoint of each active arm (last observation carried forward), a significantly higher proportion of subjects was considered improved while receiving ABT-418 than while receiving placebo (40% versus 13%). Similarly, at endpoint there was a significantly greater reduction in ADHD symptom checklist scores (28% versus 15%). Symptoms reflective of attention, and subjects with less severe ADHD, responded more robustly to ABT-418. Treatment with ABT-418 was relatively well tolerated; dizziness and nausea were the most frequently reported adverse effects.

CONCLUSIONS

The results of this investigation indicate that ABT-418, a nicotinic analog, may be a potentially useful agent for the treatment of ADHD.

[Treatment for non-cognitive symptoms in Alzheimer's disease]

OBJECTIVES

To review the classical treatment for non cognitive symptoms in Alzheimer's disease and to estimate the possible future contributions.

DEVELOPMENT

The non cognitive symptoms, with a high frequency in dementia, mean a larger clinical severity, an increment of institutionalization and a larger carer's emotional burden. Several treatment frequently used has been reviewed (antipsychotic, antidepressant, antianxiety, anticonvulsive...) and the response for some of this symptoms is relatively narrow and side effects are frequent and intense. New drugs, as cholinesterase inhibitors and cholinergic agonist, that have demonstrated their efficacy for the cognitive symptoms, seem to be also effective for non cognitive ones.

CONCLUSION

The relative low effectivity of classical treatment and the frequency and intensity of side effects open new possibilities to cholinesterase inhibitors in the treatment of non cognitive symptoms in Alzheimer's disease.