Hepcidin: a novel peptide hormone regulating iron metabolism

BackgroundHepcidin is a low-molecular weight hepatic peptide regulating iron homeostasis. Hepcidin inhibits the cellular efflux of iron by binding to, and inducing the internalization and degradation of, ferroportin, the exclusive iron exporter in iron-transporting cells. It has been recently recognized as a main hormone behind anemia of chronic disease.MethodA comprehensive literature search was conducted from the websites of Pubmed Central, the US National Library of Medicine's digital archive of life sciences literature (http://www.pubmedcentral.nih.gov/) and the National Library of Medicine (http://www.ncbl.nlm.nih.gov). The data was also assessed from journals and books that published relevant articles in this field.ResultHepcidin regulates iron uptake constantly on a daily basis, to maintain sufficient iron stores for erythropoiesis. Hepcidin, by its iron regulatory action on iron metabolism may be expected to have an important role in immune regulation, inflammatory diseases and malignancies. Hepcidin is the underlying cause of anemia in these clinical settings.ConclusionHepcidin analysis may prove to be a novel tool for differential diagnosis and monitoring of disorders of iron metabolism, and establishment of therapeutic measures in various disease conditions like hereditary hemochromatosis, anemia associated with chronic kidney disease, rheumatoid arthritis and cancers.     

From student laboratory to clinical environment.

OBJECTIVE: To describe a clinical laboratory practice simulation experience for clinical laboratory science (CLS) students which was intended to improve the transition from the student laboratory to the clinical environment. SETTING: University of Kentucky Center for Rural Health, a rural health professions education center for a state-assisted institution. PRACTICE DESCRIPTION: Baccalaureate-level CLS program. PRACTICE INNOVATION: Clinical laboratory practice simulation experience allows students to become familiar with the clinical environment. It also allows faculty to assess student performance and to provide students with feedback in a controlled setting. MAIN OUTCOME MEASUREMENT: Perception of benefit from the simulation experience by CLS graduates. RESULTS: CLS graduates report the simulation experience helped to prepare them for practice in the clinical environment. CONCLUSION: Clinical laboratory simulation can improve the transition to actual clinical laboratory practice and is a valuable tool to evaluate pre-clinical deficiencies.     

铁调素对慢性肾脏病患者铁代谢的调节作用及其机制

<正>自红细胞生成刺激剂(erythropoiesis stimu-lating agents,ESAs)广泛用于治疗慢性肾脏病(chronic kidney disease,CKD)贫血以来,极大地改善了CKD贫血患者的生活质量。然而,仍有约10%～20%的CKD贫血患者对ESAs治疗反应不佳[1]。     

Hypophosphatasia and the extracellular metabolism of inorganic pyrophosphate: clinical and laboratory aspects.

Hypophosphatasia is a rare inherited disorder in which the activity of the bone/liver/kidney or tissue nonspecific form of alkaline phosphatase (ALP) is reduced. The clinical expression of the disease is highly variable, but in early life the severity tends to reflect the age of onset. Accordingly, the disease is often classified into perinatal, infantile, and childhood forms. Hypophosphatasia also occurs in adults. Some exhibit symptoms in adulthood for the first time, but others have a history of the disease in early life with an intervening symptom-free period. Defective mineralization of bones and teeth is the predominant clinical feature of all forms of the disease. Biochemically, the reduction in ALP activity is associated with alterations in the extracellular metabolism of various phosphorylated compounds, including inorganic pyrophosphate (PPi), phosphoethanolamine, and pyridoxal 5'-phosphate. Of these, PPi may have an especially important role in the development of the mineralization defect. Accordingly, the extracellular metabolism of PPi and its possible role in the regulation of mineralization will be discussed.     

Infectious hazards in the clinical laboratory: a program to protect laboratory personnel

The increasing risk of exposure to blood-borne pathogens in the health care setting makes the development of effective infection control programs in the laboratory workplace critical. Central to such programs is the concept of universal precautions. The program described here relates the level of protection or precaution to the potential danger for infection, given the laboratory workstation and task which is to be performed. Four Levels of Protection are described. Implementation of this program requires that each workstation and procedure in each laboratory section be reviewed by the laboratory director and supervisory personnel for risk of exposure. Implementation additionally requires that provisions be made for both the initial and continuing education of laboratory employees. Laboratory directors and supervisors should also monitor the program to ensure compliance. There will certainly be situations unique to individual institutions or laboratory settings that may require precautions or policies over and above those described by universal precautions. Laboratory policies will not gain acceptance if they are developed and implemented without the advice and cooperation of the hospital medical staff. Employee acceptance of infection control policies will be greater if actual development and implementation actively involves the laboratory personnel who will practice them. The program described here is but one approach to the problem. Employers and laboratory directors must understand that it is their responsibility to develop a program that provides appropriate safeguards for workers who may be exposed to infectious agents in the laboratory workplace and to ensure that employees are properly trained and educated in the proper use and application of those safeguards.     

Opioids: From receptors to clinical application

Opioid analgesia is produced by activation of the endogenous opioid system, which physiologically modulates nociceptive transmission.Two main strategies are used: decrease the inactivation of transmitters (enkephalinase inhibitors) and activation of the opioid receptors by opioid analgesics. Cloning the receptors (ώ opioid receptor, d opioid receptor, k opioid receptor) has confirmed their anatomic distribution and further defined their biochemical and pharmacologic properties. Peripheral opioid receptors may have therapeutic relevance in specific disease states and induce local opioid analgesia without central side effects. Clinically used opioid analgesics are classified according to receptor interaction, and ώ-agonists are most effective.They have no ceiling effect for antinociception, but side effects prevent the use of the doses required for complete analgesia. Most recent developments in opioid pharmacology include new targets (enzymes) and changes in the pharmacokinetic profile of conventional ώ-opioids. Further research in the molecular mechanisms of opioids may result in the introduction of more effective and less harmful compounds.     

Pharmacogenomics: implications for laboratory medicine.

Pharmacogenomics deals with the interactions of individual genetic constitution with drug therapy. It has potentially far reaching consequences for drug development and future treatment strategies, but also for clinical in vitro diagnostics. With increasing knowledge about interactions between genes and drug treatment, there will be an equally increasing demand for rapid and reliable diagnostic tests prior to the institution of therapy. In fact, it is very likely that pharmacogenetic tests will make up a significant proportion of total molecular biology testing in the coming years. Therefore, this review focuses on the implications of pharmacogenomics on the clinical laboratory.     

关于胆红素升高的实验室检测与临床

黄疸即胆红素异常升高在临床上很常见.目前医院检测胆红素通常测定血中的总胆红素和直接胆红素,而以总胆红素减去直接胆红素得到间接胆红素的数值.直接胆红素主要反映结合胆红素,但二者并不完全等同.与此类似,间接胆红素主要反映非结合胆红素.在临床上,对黄疸的诊断和鉴别诊断,直接胆红素(或间接胆红素)占总胆红素的比例较之胆红素升高的幅度更有意义.通过分析直接或间接胆红素的比例,往往可以对黄疸的原因做出大致的诊断和鉴别诊断.但目前各家医院检测胆红素的方法和水平差别较大,不同疾病状态下所测出的直接或间接胆红素的比例也大不相同,给黄疸的临床诊断和鉴别诊断带来很大困惑.建议医院临检部门加强对胆红素检测的质控工作,在严格质控的基础上,适当调整各种疾病状态下胆红素的比例使之符合临床实际情况,并长期稳定.如此将对黄疸的临床诊断工作起到至关重要的作用.     

Neurophysiology of cancer pain: From the laboratory to the clinic

Pain is one of the most distressing symptoms associated with cancer. Basic science research has provided much insight into the mechanisms of peripheral and central pain and the actions of new drugs. Despite these advances, pain accompanying malignancy can be difficult to treat. Pain most commonly presents when the tumor has invaded somatic,visceral, or neural structures. An understanding of pain mechanisms is essential when deciding on the appropriate treatment. New therapeutic options have been developed and will hopefully provide clinicians with tools to successfully alleviate cancer pain.     

From clinical trials to clinical practice: Generalizing from participant to patient

This paper uses the report of the Lipid Research Clinics Coronary Primary Prevention Trial as an example of how clinicians apply the results of clinical trials to their practice. Clinical trials influence practice primarily to the extent that they eventually become incorporated into the generally accepted standard of medical care. To a lesser extent, physicians are influenced by their own interpretation of clinical trial results. Since physicians usually do not have the leisure or the technical expertise to evaluate primary data critically, their conclusions are heavily influenced by the authors' sometimes overoptimistic interpretation of the results. Therefore, practicing clinicians often overestimate the benefits of a therapy and generalize the results of a trial too broadly. Ideally, physicians should base treatment decisions on their knowledge of the pathophysiology of the disease, the mechanism of action of the proposed treatment, and the clinical characteristics of the individual patient while informing their decision with a critical understanding of the results of relevant trials.     

An office-based approach to influenza: clinical diagnosis and laboratory testing

Vaccination is the primary measure for preventing morbidity and mortality from influenza. During the influenza season, family physicians must distinguish influenza from the common cold and other flu-like illnesses. Signs and symptoms of influenza include abrupt onset of fever, severe myalgias, anorexia, sore throat, headache, cough, and malaise. Clinical diagnosis can be difficult or nonspecific when patients have other symptoms (e.g., stuffy nose, sneezing, cough, sore throat) that can be caused by various respiratory viruses or bacterial pathogens. Family physicians can improve diagnostic accuracy by being aware of the epidemiology of influenza. During outbreaks of influenza, commercially available rapid assays can be used to identify type A and B viruses. On average, rapid in-office tests are more than 70 percent sensitive and 90 percent specific for viral antigens. The assays vary in complexity, specificity, sensitivity, time to obtain results, specimen analyzed, and cost. The results of rapid viral tests can guide treatment decisions.     

Clinical laboratory technician to clinical laboratory scientist articulation and distance learning.

Laboratory workers and educators alike are challenged to support access to education that is current and provides opportunities for career advancement in the work place. The clinical laboratory science (CLS) program at the Medical College of Georgia in Augusta developed a clinical laboratory technician (CLT) to CLS articulation option, expanded it through distance learning, and integrated computer based learning technology into the educational process over a four year period to address technician needs for access to education. Both positive and negative outcomes were realized through these efforts. Twenty-seven students entered the pilot articulation program, graduated, and took a CLS certification examination. Measured in terms of CLS certification, promotions, pay raises, and career advancement, the program described was a success. However, major problems were encountered related to the use of unfamiliar communication technology; administration of the program at distance sites; communication between educational institutions, students, and employers; and competition with CLT programs for internship sites. These problems must be addressed in future efforts to provide a successful distance learning program. Effective methods for meeting educational needs and career ladder expectations of CLTs and their employers are important to the overall quality and appeal of the profession. Educational technology that includes computer-aided instruction, multimedia, and telecommunications can provide powerful tools for education in general and CLT articulation in particular. Careful preparation and vigilant attention to reliable delivery methods as well as students' progress and outcomes is critical for an efficient, economically feasible, and educationally sound program.