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Biomedical subjects

A May

Publications and source records attributed to A May.

At least 73 records · Page 4Linked to original sources

Ethical aspects of placebo in migraine research.

Randomized placebo-controlled clinical trials have been the 'golden standard' during the last decades in the development of new drug therapies. This scientifically valid approach has recently been questioned in the fifth revised version of the Declaration of Helsinki, which states that the use of placebo-controlled clinical trials is only acceptable when no proven treatment exists for the studied disease. The World Medical Association further claims that no national ethical, legal or regulatory requirements should be allowed to reduce or eliminate any of the statements in the declaration. In spite of this, the document is not generally accepted as the world ethical standard, as demonstrated by its lack of adoption by many professional associations. In the evaluation process for a drug to be approved in many countries today, clinical investigators at the hospitals and researchers at the pharmaceutical companies are obliged to use study protocols that would be rejected if the new declaration were to be fully adopted. Adherence to the clinical trial guidelines of the International Headache Society could also mean violation of the new Helsinki declaration of ethics. Some ethics committees have already adopted the new declaration, which has caused concern among clinical investigators, who find this document to be vastly out of the line with common practice. At the moment, the situation is unclear and debated with increasing polarity concerning the scientific and ethical issues regarding the use of placebo in clinical trials.

Adolescent↗

[Trigemino-autonomic headache syndromes].

This review describes the characteristics of some rare severe primary headache syndromes without any structural lesions, which are summarized as the trigemino-autonomic headaches. Pain in these syndromes is associated with autonomic symptoms such as conjunctival injection, lacrimation, rhinorrhoe, ptosis or eyelid edema. This article summarizes the diagnostics, epidemiology and therapy of these conditions.

Autonomic Nervous System Diseases↗

Double-balloon enteroscopy: preliminary experience in patients with obscure gastrointestinal bleeding or chronic abdominal pain.

BACKGROUND AND STUDY AIMS: Even in the era of capsule endoscopy, diseases of the small bowel are sometimes difficult to diagnose, and endoscopic treatment is not possible without surgical laparotomy. The new method of carrying out enteroscopy using a double-balloon technique allows not only diagnostic but also therapeutic endoscopic interventions for lesions in the small bowel. Preliminary experience with this new method is reported here. PATIENTS AND METHODS: Between the end of March 2003 and August 2003, eight patients (four women, four men; mean age 59 +/- 23 years, range 20 - 90) with chronic gastrointestinal bleeding or abdominal pain, or both, underwent enteroscopy using the double-balloon technique. Seven of the patients had been suffering from chronic gastrointestinal bleeding for 56 +/- 49 months (range 3 - 120 months, median 48 months). The lowest hemoglobin levels ranged from 3.6 g/dl to 8.6 g/dl (mean 6.7 +/- 1.7 g/dl), and a mean of 7.6 +/- 5.6 (range 1 - 15) blood units had been transfused. Capsule endoscopy was carried out in six patients, revealing angiodysplasias in three, suspected Crohn's disease in one, fresh blood in the small bowel without a lesion in one, and a focal enanthema in another patient. RESULTS: Enteroscopy with the double-balloon technique was carried out using the oral approach in all patients and additionally with the anal approach in four patients. In two patients with multiple angiodysplasias, it was possible to examine the whole small bowel and to treat the angiodysplasias. All of the capsule endoscopy findings were confirmed; a definite bleeding source was found and treated in two patients with unclear bleeding, and in another patient the real bleeding source was found (not angiodysplasia). The enteroscopy system was easy to handle in all cases. No complications occurred. It was possible to carry out the procedure with the patients under sedoanalgesia. CONCLUSIONS: This new enteroscopy system is easy to handle and seems to be safe. Visualization of the whole small bowel is possible using both the oral and anal approaches. Enteroscopy with the double-balloon technique promises to become a standard method for diagnostic and therapeutic endoscopy of the small bowel without surgical laparotomy.

Abdominal Pain↗

[Diagnosis and therapy of early neoplasia in Barrett's esophagus].

There has been a dramatic increase in recent years in the incidence of Barrett's esophagus and the esophageal adenocarcinoma associated with it. Adequate monitoring strategies and improved diagnostic procedures are therefore essential. Alongside conventional video endoscopy with four-quadrant biopsies, many additional diagnostic procedures are now available to improve monitoring. These allow early diagnosis of dysplastic areas and early carcinomas. Endoscopic therapy has gained more and more importance in the treatment of early esophageal neoplasias over the last few years. Localized lesions in the Barrett's segment should be treated by endoscopic resection (ER). Only in patients with not localized or multifocal superficial lesions photodynamic therapy (PDT) should be used. Between the different ER techniques the "suck and cut"-technique with ligation device or cap should be favoured to normal strip biopsy in the esophagus because of the size of the resected specimen and its technical feasibility. ER of high grade intraepithelial neoplasia and mucosal adenocarcinoma in Barrett's esophagus should be considered as the treatment of choice. ER of early neoplasia in Barrett's esophagus is a safe and effective method but should only be performed by experienced endoscopists.

Adenocarcinoma↗

[Barrett esophagus--esophageal carcinoma: conservative therapy and observation].

Chronic acid reflux is strongly associated with cancer of the esophagogastric junction and the main reason for the development of specialised intestinalised metaplasia in the esophagus (Barrett's esophagus). Endoscopic surveillance, therefore, is mandatory for long-segment Barrett's esophagus as well as short segment Barrett's. Videoendoscopy with four quadrant random biopsies are standard and new diagnostic tools like chromoendoscopy with methylene blue, magnifying endoscopy or fluorescence detection may turn out to be helpful. Differential surveillance strategies according to the recommendations of the American College of Gastroenterology and the Deutschen Gesellschaft für Verdauungs- und Stoffwechselerkrankungen should be performed for medical and cost-efficiency reasons. Local endoscopic therapy of early cancer and high-grade dysplasia in Barrett's esophagus comprises three different methods: endoscopic mucosal resection (EMR), semiselective, athermal photodynamic therapy (PDT) and thermal techniques such as KTP- or Nd:YAG-laser and argon-plasma coagulation. All endoscopic methods have low morbidity and mortality rates compared to esophageal resection and therefore are an attractive alternative treatment option. Endoscopic mucosal resection is the treatment of choice for all localizable and circumscribed lesions, because the resected specimen can be classified with regard to the histopathological grading, complete resection and submucosal involvement, especially in view of patients who are surgical candidates. PDT is the best local treatment option for multifocal, not localizable or large superficial lesions, as large areas can be treated in a single therapeutic session. Thermal procedure are mainly auxiliary methods for the optimization of EMR or PDT. The shortterm and intermediate results of our studies appear to be promising in view of the high complete local remission rates in combination with the low morbidity and mortality.

Barrett Esophagus↗

Intractable eye pain: indication for triptans.

Management of pain is difficult in many eye diseases. Particularly in patients undergoing surgical procedures, postoperative intractable pain is a major concern and severely influences the patient's comfort. We present 13 patients (eight male, five female, mean age 36 years) in whom sumatriptan, a highly selective 5-HT1B/1D agonist that is normally used as a specific anti-migraine drug, was used for the treatment of pain following photorefractive keratectomy (PRK). In two patients both eyes were operated on different days, resulting in a total of 15 operated eyes. A positive clinical response was achieved in all patients. In particular, in four patients, who received a second dose prophylactically 4 h following the first dose and before the recurrence of pain, we achieved excellent efficacy and stable control of pain. Further controlled studies are needed to investigate the usefulness of 5-HT1B/1D agonists in painful eye conditions.

Adult↗

Endoscopic therapy for Zenkers's diverticulum by means of argon plasma coagulation.

We describe a 80-year-old man who presented with progressive dysphagia because of a Zenker's diverticulum. Barium swallow study revealed a large posterior diverticulum with a distal stenosis of the esophagus caused by compression. Because the patient was a poor candidate for surgery an endoscopic therapy was performed. The Zenker bridge was divided by argon plasma coagulation in two sessions without any complication to allow an overflow. The patient remained asymptomatic to date for a follow-up of 6 months.

Aged↗

Intraepithelial high-grade neoplasia and early adenocarcinoma in short-segment Barrett's esophagus (SSBE): curative treatment using local endoscopic treatment techniques.

BACKGROUND AND STUDY AIMS: In recent years, short-segment Barrett's esophagus (SSBE) has attracted increasing attention in the context of reflux disease. However, there is continuing controversy regarding its potential for malignant transformation. PATIENTS AND METHODS: Between October 1996 and September 1999, 50/115 patients (43 %) with intraepithelial high-grade neoplasia or early Barrett's adenocarcinoma, who underwent local endoscopic treatment, had developed a malignant lesion in an (SSBE). In the framework of a prospective observational study, 28 patients were treated with endoscopic mucosal resection (EMR), 13 with photodynamic therapy, and three with argon plasma coagulation; six patients received combinations of these treatments. RESULTS: Complete local remission was achieved in 48/49 patients (98 %). One patient switched to surgery after the first EMR, because there was submucosal tumor infiltration, and in one patient out of 50 local endoscopic treatment failed. A mean of 1.7 +/- 1.4 treatment sessions was required for local endoscopic treatment. The method-associated mortality was 0 %. The rate of relevant complications (stenosis, bleeding) was 6 % (3/50 patients). No cases of severe hemorrhage (Hb fall >2 g/dl) or perforation occurred. During a mean follow-up period of 34 +/- 10 months, metachronous intraepithelial high-grade neoplasms or early adenocarcinomas were seen in 11/48 patients (23 %), who received further successful endoscopic treatment. Four patients died during the follow-up period, but in only one patient was this due to his Barrett's adenocarcinoma (this was the patient who underwent esophageal resection). CONCLUSIONS: The malignant potential of short-segment Barrett's esophagus must not be underestimated. Organ-preserving local endoscopic treatment shows good acute-phase and long-term results. Local endoscopic treatment represents an alternative to esophageal resection in the case of intraepithelial high-grade neoplasia and selected early adenocarcinomas in Barrett's esophagus.

Adenocarcinoma↗

The first prospective controlled trial comparing wireless capsule endoscopy with push enteroscopy in chronic gastrointestinal bleeding.

BACKGROUND AND STUDY AIMS: In chronic gastrointestinal bleeding (CGB), bleeding sites located in the small bowel are difficult to detect with conventional radiological or scintigraphic techniques. Push enteroscopy (PE) is at present considered to be the most effective diagnostic procedure. The aim of this prospective trial was to compare the efficacy of wireless capsule endoscopy (CE) with PE. PATIENTS AND METHODS: Between April and October 2001, 65 patients with CGB were referred to our unit. Complete conventional diagnostic work-up (including small-bowel enteroclysis, angiography, and scintigraphy), as well as PE and CE, were performed in 32 patients. RESULTS: On average, the patients had been suffering from CGB for 29 +/- 24 months (6 - 126); the lowest hemoglobin level varied between 3.0 and 9.9 g/dl (mean 5.9 +/- 1.4); 17 +/- 18 blood units (0 - 60) were transfused. Each patient underwent 6 +/- 7 (range 1 - 38) hospitalizations, with a mean of 14 +/- 9 diagnostic procedures before CE was used. Conventional diagnostic procedures revealed relevant pathological findings in five of the 32 patients (16 %). Definite bleeding sites diagnosed by PE in nine patients (28 %) included angiodysplasia (seven patients), small-bowel cancer (one patient) and lymphoma (one patient). CE detected the definite source in 21 of the 32 patients (66 %) ( P < 0.001). Definite bleeding sources included angiodysplasia (17 patients), malignant stenoses (two patients) and inflammatory small-bowel disease (two patients). Questionable bleeding sources were seen on PE in three additional patients (9 %), and using CE in a further seven patients (22 %). Both CE and PE were safe and were not associated with any morbidity. CONCLUSIONS: In the present trial in patients with CGB, wireless CE had the highest diagnostic yield and was significantly superior to PE. CE can help reduce the number of diagnostic procedures and could become the initial diagnostic choice in patients with CGB and negative upper and lower gastrointestinal endoscopy.

Adult↗

[Emergencies in general practice, 1. Headache as an alarm symptom].

Primary headache, such as migraine and tension type headache is a common symptom in patients presenting in emergency departments. Suspicious of secondary headache is a medical history of new onset, changing character of a previously known headache, resistancy to medication or symptoms which are not typical of primary headache.

Brain Diseases↗

Hypothalamic involvement and activation in cluster headache.

Cluster headache is an episodic form of primary neurovascular headache that is both severe and relatively rare. It is characterized by episodes of headache with cranial parasympathetic activation and sympathetic impairment that come in bouts, or clusters. Its pathophysiology can be divided into understanding the attack phenotype and the biotype of the periodicity. Acute attacks of cluster headache are marked by trigeminal nerve-mediated pain and with cranial autonomic activation, trigeminal-autonomic cephalalgia; an activation that characterizes the phenotype of a group of headaches. The signature feature of cluster headache is its periodicity, the daily cycle of attacks when the patient is in an active bout, or the circumannual, or other period, cycling that distinguishes the on period from the off period. Functional brain imaging with positron emission tomography and structural imaging with voxel-based morphometry have identified an area in the posterior hypothalamic gray as key in understanding cluster headache. This area is subtly enlarged in its gray matter volume, active during an acute cluster headache but inactive when patients are challenged between bouts. Cluster headache is likely to be a form of primary neurovascular pain whose phenotypic expression relies on the trigeminal-autonomic reflex, with a biotype determined by the brain area, the posterior hypothalamus, in which the lesion seems to be located. Understanding both the phenotypic expression and the biotype will, respectively, enable better acute attack treatments and better preventative management of this horrible form of headache.

Biological Clocks↗

Objective assessment of cognitive factors involved in visceral perception by using event-related cerebral evoked responses to esophageal target stimulation in man.

Evoked potential (EP) studies provide an objective measure of the neural pathways involved with perception of gastrointestinal stimulation. The effects of cognitive factors, such as anticipation or awareness, on EP responses are not known. We compared the EP response to esophageal electrical stimulation with the cortical activity associated with target detection and anticipation of the same stimulus. In 12 healthy men (26.8+/-6 years old), esophageal electrical stimulation (0.2 Hz, 0.2 msec, 15 mA) was applied, and the EP recorded using scalp electrodes. A computerized model of randomly applied target stimuli (1:5 ratio) was used to separately record the EP associated with stimulation and the event-related cognitive EP associated with a dual task-related or anticipated stimulation approach. A periodic electrical stimulus represented the nontarget stimulus and a second electrical impulse (oddball model) or an omitted stimulus (anticipatory model) the target stimulus. The event-related cognitive EP responses were also compared with standard and anticipatory auditory P300 evoked potentials. The esophageal and auditory oddball stimulus approach elicited event-related P300EP in all subjects. P300EP associated with electrical stimulation had a longer peak latency (P < 0.0001) and smaller amplitude than those obtained with auditory stimulation. Anticipatory evoked potentials could be obtained by electrical skipped stimulation in 8 of 12 subjects. These EP were similar to those obtained with omitted auditory target stimulation, although of significantly smaller amplitude than auditory standard P300EP (P < 0.001). In conclusion, the brain response associated with directed effortful processing of discriminate esophageal stimuli consists of a large event-related potential (P300EP). Anticipatory stimulation produces a similar event-related cortical response, which is associated with attention to and awareness of the actual stimulus. The P300EP to gastrointestinal stimuli may provide an objective and powerful electrophysiological tool for the assessment of the cognitive factors associated with visceral perception.

Adult↗