Melatonin: a hormone,a tissue factor,an autocoid,a paracoid,and an antioxidant vitamin

Melatonin, a derivative of an essential amino acid, tryptophan, was first identified in bovine pineal tissue and subsequently it has been portrayed exclusively as a hormone. Recently accumulated evidence has challenged this concept. Melatonin is present in the earliest life forms and is found in all organisms including bacteria, algae, fungi, plants, insects, and vertebrates including humans. Several characteristics of melatonin distinguish it from a classic hormone such as its direct, non-receptor-mediated free radical scavenging activity. As melatonin is also ingested in foodstuffs such as vegetables, fruits, rice, wheat and herbal medicines, from the nutritional point of view, melatonin can also be classified as a vitamin. It seems likely that melatonin initially evolved as an antioxidant, becoming a vitamin in the food chain, and in multicellular organisms, where it is produced, it has acquired autocoid, paracoid and hormonal properties.     

Dysphagia,an unrecognized handicap

The aim of this study was to examine whether esophageal dysphagia can be described as a handicap and to grade the severity of handicap as the discrepancy between the subject's own eating goals and his or her eating disability. The severity of the disability-goal-handicap (DGH) regarding dysphagia was expressed on a scale ranging from 0 to 48 points. Nineteen patients with dysphagia of differing causes were selected from a patient register at a laboratory for diagnostic procedures of the esophagus. The severity of handicap for the 19 patients was, on average, 33 points (range, 20–44). The DGH score correlated significantly with the patients' own evaluation of the severity of their dysphagia (p=0.008). The DGH scores did not differ markedly based on patient's sex, age, or cause of dysphagia. Patients who were operated upon because of dysphagia had significantly more points on the DGH scale prior to operation than patients who were not (p=0.001). Denial of dysphagia (N=18), concealment of dysphagia (N=18), and lack of confirmation by the patient's physician (N=15) were common but did not influence the severity of handicap as assessed by the DGH scale. It was shown that dysphagia affects all aspects of life as expressed by reduction in self-esteem (N=13), security (N=16), work capacity (N=8), exercise (N=7), and leisure time (N=6). Esophageal dysphagia may therefore be regarded as a handicap when assessed using the DGH code described in this study.     

Preeclampsia,an Implantation Disorder

Reviews in Endocrine and Metabolic Disorders -     

Adiponectin,an Unlocking Adipocytokine

A large number of studies revealed that adiponectin, a protein secreted specifically by adipose tissue, exhibits antiinflammatory, antiatherogenic, and antidiabetic properties. This 247‐amino acid protein contains four differentiable domains and exists in five different configurations, which binds three kinds of receptors. The plasma adiponectin concentration is at amazing microgram level and the gender difference is very clear. Obese subjects showed decreased plasma level of adiponectin while exercise seems to restore it. Many researchers demonstrated that it could be a reliable biomarker for multiple diseases. However, there is controversy about its role in inflammation since its plasma concentration decreases in some inflammatory diseases and increases under some other inflammatory conditions. The signal transduction pathway is still not very clear yet. Could adiponectin be a promising drug target?     

Chikungunya, an epidemic arbovirosis

Chikungunya is an arboviral disease transmitted by aedes mosquitoes. The virus was first isolated in 1953 in Tanzania. Chikungunya virus is a member of the genus Alphavirus and the family Togaviridae. The disease typically consists of an acute illness characterised by fever, rash, and incapacitating arthralgia. The word chikungunya, used for both the virus and the disease, means "to walk bent over" in some east African languages, and refers to the effect of the joint pains that characterise this dengue-like infection. Chikungunya is a specifically tropical disease, but it is geographically restricted and outbreaks are relatively uncommon. It is only occasionally observed in travellers and military personnel. More than 266 000 people have been infected during the ongoing outbreak in Réunion, in which Aedes albopictus is the presumed vector. In the ongoing Indian outbreak, in which Aedes aegypti is the presumed vector, 1 400 000 cases of chikungunya were reported during 2006. The reasons for the re-emergence of chikungunya on the Indian subcontinent, and for its unprecedented incidence rate in the Indian Ocean region, are unclear. Plausible explanations include increased tourism, chikungunya virus introduction into a naive population, and viral mutation.     

Haemoglobin Etobicoke,an incidental finding in an Irish diabetic

It is well recognized that haemoglobin variants can be detected during the measurement of HbA1c by high-performance liquid chromatography (HPLC). A number of variants have been reported as compromising the quantification of HbA1c, a marker used in the assessment of glycaemic control in diabetes. We describe a case of haemoglobin Etobicoke, a rare alpha chain variant detected in an Irish diabetic during HbA1c analysis. Its identity was confirmed using a series of investigations. These included haemoglobin electrophoresis at alkaline and acid pH, isoelectric focusing and globin chain electrophoresis. Ultimately mass spectrometry isolated the mutation at position alpha 84 (F5). Haemoglobin Etobicoke, first described in Canada in 1969 has not previously been detected on HbA1c analysis. In the presence of this rare variant, HbA1c, a standard method using HPLC to assess glycaemic control in diabetes is unreliable and alternatives such as fructosamine need to be considered. HbA1c measured by automated HPLC will effectively screen populations where haemoglobin variants were not previously known. Precise identity of these variants when they are detected is crucial to the reliable interpretation of HbA1c analyses.     

Haemoglobin Etobicoke,an incidental finding in an Irish diabetic

It is well recognized that haemoglobin variants can be detected during the measurement of HbA_1c by high‐performance liquid chromatography (HPLC). A number of variants have been reported as compromising the quantification of HbA_1c, a marker used in the assessment of glycaemic control in diabetes. We describe a case of haemoglobin Etobicoke, a rare alpha chain variant detected in an Irish diabetic during HbA_1c analysis. Its identity was confirmed using a series of investigations. These included haemoglobin electrophoresis at alkaline and acid pH, isoelectric focusing and globin chain electrophoresis. Ultimately mass spectrometry isolated the mutation at position alpha 84 (F5). Haemoglobin Etobicoke, first described in Canada in 1969 has not previously been detected on HbA_1c analysis. In the presence of this rare variant, HbA_1c, a standard method using HPLC to assess glycaemic control in diabetes is unreliable and alternatives such as fructosamine need to be considered. HbA_1c measured by automated HPLC will effectively screen populations where haemoglobin variants were not previously known. Precise identity of these variants when they are detected is crucial to the reliable interpretation of HbA_1c analyses.     

Pneumothorax,an underappreciated complication with an airway exchange catheter

While airway exchange catheters (AEC) are designed to safely maintain a secure airway and sometimes allow for ventilation while exchanging an endotracheal tube or performing a trial tracheal extubation, their use is sometimes associated with devastating complications. Pneumothorax is an underappreciated complication with AECs that can occur even in the absence of high pressure ventilation with quick clinical deterioration. The development of a pneumothorax can be difficult to distinguish from other potential causes of clinical deterioration and the clinician should maintain a high level of suspicion for quick diagnosis and treatment. Here we report a case of tension pneumothorax leading to cardiovascular collapse that occurred very suddenly with the introduction of an AEC. This pneumothorax presented in an atypical manner by all monitors available except for blood pressure monitoring. Therefore this case highlights the need for strong clinical suspicion of pneumothorax with the use of AECs.KEY WORDS : Airway exchange catheters (AEC), pneumothorax     

Uroguanylin, an intestinal natriuretic peptide, is delivered to the kidney as an unprocessed propeptide

Orally delivered salt stimulates renal salt excretion more effectively than does iv delivered salt. Although the mechanisms that underlie this "postprandial natriuresis" are poorly understood, the peptide uroguanylin (UGn) is thought to be a key mediator. However, the lack of selective assays for UGn gene products has hindered rigorous testing of this hypothesis. Using peptide-specific assays, we now report surprisingly little UGn in rat intestine or plasma. In contrast, prouroguanylin (proUGn), the presumed-inactive precursor of UGn, is plentiful (at least 40 times more abundant than UGn) in both intestine and plasma. The intestine is the likely source of the circulating proUGn because: 1) the proUGn portal to systemic ratio is approximately two under normal conditions, and 2) systemic proUGn levels decrease rapidly after intestinal resection. Together, these data suggest that proUGn itself is actively involved in enterorenal signaling. This is strongly supported by our observation that iv infusion of proUGn at a physiological concentration produces a long-lasting renal natriuresis, whereas previously reported natriuretic effects of UGn have required supraphysiological concentrations. Thus, our data point to proUGn as an endocrine (i.e. circulating) mediator of postprandial natriuresis, and suggest that the propeptide is secreted intact from the intestine into the circulation and processed to an active form at an extravascular site.     

Stunned myocardium,an opinionated review

The discovery of stunned myocardium (5) was made possible by a new technical device: the measurement of distance by sonomicrometer crystals (3). Stunned myocardium cannot be readily detected by the naked eye and even the micrometer trace must be analyzed for correct phase.     

氯沙坦对实验性糖尿病大鼠心肌的保护作用

目的探讨糖尿病性心肌病的发生、发展并试用氯沙坦干预治疗,为糖尿病性心肌病的防治提供参考。方法建立３个月、６个月糖尿病大鼠模型（糖尿病组）,放射免疫法测定糖尿病组血浆及心肌局部血管紧张素Ⅱ（ＡｎｇⅡ）、测定心脏重量指数、ｄｐ／ｄｔｍａｘ比值并作心肌形态学观察,与对照组、氯沙坦干预组相比较。结果糖尿病组心肌局部ＡｎｇⅡ６个月明显增高,血浆ＡｎｇⅡ３个月、６个月持续增高;心脏重量指数３个月、６个月持续高