Length of stay an important mediator of hospital-acquired methicillin-resistant Staphylococcus aureus.

Hospital-acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) is becoming increasingly established in Asian hospitals. The primary aim of this study was to decompose the risk factors for HA-MRSA based on conceptual clinical pathways. The secondary aim was to show the amount of effect attributable to antibiotic exposure and total length of stay before outcome (LBO) so that institutions can manage at-risk patients accordingly. A case-control study consisting of 1200 inpatients was conducted in a large tertiary hospital in Singapore between January and December 2006. Results from the generalized structural equation model (GSEM) show that LBO [adjusted odds ratio (aOR) 14·9, 95% confidence interval (CI) 8·7-25·5], prior hospitalization (aOR 6·2, 95% CI 3·3-11·5), and cumulative antibiotic exposure (aOR 3·5, 95% CI 2·3-5·3), directly affected HA-MRSA acquisition. LBO accounted for the majority of the effects due to age (100%), immunosuppression (67%), and surgery (96%), and to a lesser extent for male gender (22%). Our model enabled us to account and quantify effects of intermediaries. LBO was found to be an important mediator of age, immunosuppression and surgery on MRSA infection. Traditional regression approaches will not only give different conclusions but also underestimate the effects. Hospitals should minimize the hospital stay when possible to reduce the risk of MRSA.

Psychological well-being of interns in Hong Kong: what causes them stress and what helps them.

BACKGROUND: Many doctors experience psychological ill health. Interns are known to be particularly vulnerable. AIM: To examine the level of depression, anxiety and stress in interns in Hong Kong, as well as the causes and how they cope. METHODS: A questionnaire was designed based on the themes identified in three focus groups of medical graduates of Year 2004 of the University of Hong Kong. The 21-item Depression, Anxiety and Stress Scale (DASS 21) was also administered. All 155 graduates of the same year were invited to participate with a response rate of 63%. RESULTS: Percentages of respondents with abnormal levels of depression, anxiety and stress were 35.8%, 35.4% and 29.2%, respectively. Frequent calls during night shift, long working hours and heavy workload constituted the most significant stressors. Factor analysis of the stressors showed that seven factors could explain 68% of the total variance: multidisciplinary team working issues, clinical difficulties, job seeking and employment, workload issues, ethical and interpersonal issues, adjustment to job rotation and performance appraisal. Holidays, peers and sleep offered the most significant relief. CONCLUSION: Interns experience considerable depression, anxiety and stress. The source of stress is multi-faceted, but workload is the most significant stressor. Peer support groups may relief stress.

Focal Choroidal Excavation and Central Serous Chorioretinopathy Following Choroidal Neovascularization: A Longitudinal Case Study.

Purpose: This report describes the development of focal choroidal excavation (FCE) and recurrent central serous chorioretinopathy (CSCR) following the treatment of choroidal neovascularization (CNV) years earlier. Methods: A case report is presented. Results: A 30-year-old man previously treated for an active CNV returned several years later with subacute metamorphopsia. Optical coherence tomography and angiography demonstrated no recurrence of the CNV but instead found an FCE and associated CSCR in its place. Conclusion: Longitudinal follow-up with multimodal imaging demonstrated FCE with recurrent CSCR as possible sequelae of treated CNV.

A triggered mechanism retrieves membrane in seconds after Ca(2+)-stimulated exocytosis in single pituitary cells.

In neuroendocrine cells, cytosolic Ca2+ triggers exocytosis in tens of milliseconds, yet known pathways of endocytic membrane retrieval take minutes. To test for faster retrieval mechanisms, we have triggered short bursts of exocytosis by flash photolysis of caged Ca2+, and have tracked subsequent retrieval by measuring the plasma membrane capacitance. We find that a limited amount of membrane can be retrieved with a time constant of 4 s at 21-26 degrees C, and that this occurs partially via structures larger than coated vesicles. This novel mechanism may be arrested at a late step. Incomplete retrieval structures then remain on the cell surface for minutes until the consequences of a renewed increase in cytosolic [Ca2+] disconnect them from the cell surface in < 1 s. Our results provide evidence for a rapid, triggered membrane retrieval pathway in excitable cells.

A low affinity Ca2+ receptor controls the final steps in peptide secretion from pituitary melanotrophs.

Using flash photolysis of caged Ca2+ and the membrane capacitance to monitor exocytosis, we have studied the response of single melanotrophs to a step rise in cytosolic Ca2+ concentration ([Ca2+]i). Exocytosis begins with a rapid burst. This burst is followed by a slower phase, which is inhibited at cytosolic pH 6.2, and an ultraslow phase, which is strongly temperature sensitive. The exocytic burst starts with a delay of 6-11 ms and continues at a rate that grows steeply with [Ca2+]i and is half-maximal at [Ca2+]i = 27 microM. At least 3 Ca2+ ions are required to trigger exocytosis. The rate constant at saturating [Ca2+]i suggests that exocytosis of a dense core vesicle takes 40 ms after all Ca2+ ions have bound to their regulatory sites. If docked dense core vesicles cause the exocytic burst, they must decorate the plasma membrane at a mean density of 0.5/micron2.

An innovative web-based peer support system for medical students in Hong Kong.

BACKGROUND: Psychological morbidity is commonly found in medical students. AIMS: The Mental Health Support Group (MSG), a student-initiated and student-run web-based peer support service aims to provide mental health information, e mail counseling and an online forum for medical students. METHODS: The development process of MSG is described in the paper with presentation of preliminary evaluation results. RESULTS: Preliminary evaluation shows promising results. Student members of MSG acquired valuable skills in counseling, communication, webpage design and maintenance of an online forum. CONCLUSIONS: Future challenges include succession issues, strategies to keep up the momentum, enhancement of publicity and further diversification of service to meet the needs of our students.

Flow separation on flapping and rotating profiles with spanwise gradients.

The growth of leading-edge vortices (LEV) on analogous flapping and rotating profiles has been investigated experimentally. Three time-varying cases were considered: a two-dimensional reference case with a spanwise-uniform angle-of-attack variation α; a case with increasing α towards the profile tip (similar to flapping flyers); and a case with increasing α towards the profile root (similar to rotor blades experiencing an axial gust). It has been shown that the time-varying spanwise angle-of-attack gradient produces a vorticity gradient, which, in combination with spanwise flow, results in a redistribution of circulation along the profile. Specifically, when replicating the angle-of-attack gradient characteristic of a rotor experiencing an axial gust, the spanwise-vorticity gradient is aligned such that circulation increases within the measurement domain. This in turn increases the local LEV growth rate, which is suggestive of force augmentation on the blade. Reversing the relative alignment of the spanwise-vorticity gradient and spanwise flow, thereby replicating that arrangement found in a flapping flyer, was found to reduce local circulation. From this, we can conclude that spanwise flow can be arranged to vary LEV growth to prolong lift augmentation and reduce the unsteadiness of cyclic loads.

Costimulation of CD4+ T cells via CD28 modulates human immunodeficiency virus type 1 infection and replication in vitro.

Stimulation of human immunodeficiency virus type 1 (HIV-1)-infected donor peripheral blood mononuclear cells (PBMCs) via the TCR-CD3 complex induces HIV-1 production in vitro (Zarling JM, et al.: Nature [London] 1990;347:92; Haffar OK, et al.: J Virol 1992;66:4279; Moran PM, et al.: AIDS Res Hum Retroviruses 1993;9:455). However, in addition to the primary stimulatory signal delivered through the TCR-CD3 complex, optimal T cell activation requires secondary or costimulatory signals delivered via various T cell accessory proteins (Alton A, et al.: Adv Immunol 1990;48:227). In this article we explore the role of costimulation of T cells via CD28 in HIV-1 replication. Ligation of CD28 with either a CD28-specific MAb or by coculture of PBMCs with Chinese hamster ovary (CHO) cell lines stably expressing either of the CD28 counterreceptors, B7-1 (CD80) or B7-2 (CD86), concomitant with stimulation via CD3, results in increased virus replication compared to stimulation via CD3 alone. CD28 ligation also augments de novo infection of CD3-stimulated seronegative donor PBMCs with cell-free virus. Increased virus replication following CD28 ligation is not solely attributed to increased levels of endogenous IL-2, because addition of an anti-IL-2-neutralizing antibody only partially inhibits the response. In contrast, interfering with the interaction between CD28 and its counterreceptors on antigen-presenting cells (APCs) using CTLA4Ig effectively inhibits virus replication. At high concentrations CTLA4Ig also reduces cell proliferation. These in vitro results suggest that CD28 plays a central role in HIV-1 replication and that interfering with the CD28 costimulatory pathway may modify the course of HIV-1 infection.

The Duke Minority Medical Student Summer Fellowship: one program's attempt to attract minority residents.

Despite numerous Federal and private funding programs aimed at increasing the numbers of underrepresented minorities in medicine, the participation of minority groups in the medical profession remains low and shows little sign of improvement. With the goal of improving minority representation in our primary care residency program, the Minority Medical Student Summer Fellowship started in July 1990. The program's purpose is to give minority medical students positive exposure to primary care and attract them back for residency training. In this four-week elective, students participate in seminars with our primary care residents, see patients in a variety of clinics, and complete a project. Key implementation issues include support of the medicine chairman and dean, funding, and malpractice coverage for the students. Program evaluation from the first two students rated the clinic experiences higher than the seminar sessions and the independent project. Both students stated our fellowship made them more likely to train at this medical center should they enter a primary care program. Implications for other programs are listed.

Reducing financial barriers enhances the return rate of stool Hemoccult packets.

Patient compliance in returning fecal-hemoccult card packets has been studied in recent years but no specific interventions have been shown consistently to improve the return rate. It was wondered whether removing a small financial barrier for indigent patients would positively affect compliance. Therefore, the effect of prepaid postage on the rate of return was studied. Pre-prepared packets containing hemoccult cards with return envelopes were distributed in a randomized fashion to indigent and private insurance patients in outpatient clinics. On half of the return envelopes return postage was applied. The main outcome measure was the rate of return of stamped and unstamped packets stratified between indigent and private insurance patients. The overall rates of return were 117 of 159 (74%) for the stamped packets and 102 of 166 (61%) for unstamped packets (p < 0.02). After stratification, in the indigent patients (n = 177), 73 of 95 (77%) stamped packets were returned compared to 46 of 82 (56%) unstamped packets (p < 0.006). In the private insurance patients (N = 148), 44 of 64 stamped packets (69%) and 52 of 84 unstamped packets (62%) were returned (p > 0.10). Removing even small financial barriers (eg, providing a postage stamp) can enhance compliance for indigent patients.

Effect of duration of passive stretch on hip abduction range of motion.

The purpose of this study was to determine which of three durations of a passive stretch was most effective in increasing hip abduction range of motion (ROM) in human subjects. Seventy-two men were randomly assigned into a control group and three passive stretch groups (15 seconds, 45 seconds, and 2 minutes). The two measurements used to determine hip abduction flexibility were abduction ROM and resistance to abduction force. Each subject was measured before and immediately following the passive stretch to determine changes in abduction ROM and resistance to abduction force due to a passive stretch. The results of this study indicated that hip abduction ROM was significantly increased and resistance to hip abduction force was significantly decreased after a passive stretch for all three stretch groups. There was no significant difference between mean differences of abduction ROM of the three stretch groups, except for the comparison of the 15 second and the 45 second stretch groups. The results of the force data demonstrated no significant difference between the mean differences of the three stretch groups. The fact that our data shows 15 seconds is just as effective as stretching for 2 minutes makes it reasonable to stretch for 15 seconds in athletic settings where immediate increases in abduction ROM are desired. J Orthop Sports Phys Ther 1987;8(8):409-416.

A practical guide to capacity assessment and patient consent in Hong Kong.

A person's decision-making capacity is pivotal when a doctor determines whether a person has the ability to make his or her own decisions, and thus it has major clinical, ethical, and legal significance, especially in Hong Kong, where the Mental Health Ordinance has introduced Guardianship provisions and provisions for the treatment of mentally incapacitated persons. This paper examines the legal concept of decision-making capacity and its clinical assessment within the local context. It is important for doctors to be aware of the legal mechanisms under which both urgent and non-urgent treatment can be given to mentally incapacitated persons, provided that the treatment is necessary and given in the best interests of the patient.

How to help your patients quit smoking. Strategies that work.

Cessation of cigarette smoking is important to promotion of good health. Costs of smoking in terms of illness, expenditures, and loss of productivity are enormous. The most successful strategies are those that combine a structured behavior modification plan with a pharmacologic aid to alleviate nicotine dependence. Primary care physicians have an especially important role in helping patients stop smoking. By helping smokers to quit, physicians can improve the general health of these patients and significantly reduce the healthcare burden on society.

To screen or not to screen for HIV in pregnant women. Pros and cons of routine screening and use of home test kits.

Emotions run high when it comes to who should and who should not be tested for HIV. Now, as the debate heats up over screening of all pregnant women and their babies, primary care physicians may find themselves caught in the fray. Recent approval of home HIV test kits allows patients to test themselves, but can the results be trusted? Dr. Wong summarizes the contentious issues, looks at the debate from both sides, provides supportive documentation when available, and points out the "knowledge gaps."

Efficiency and effectiveness in the urgent care clinic.

Events at an urgent care clinic are unpredictable. On a given day, a practitioner may be challenged, bored, frustrated, and excited by patients and the problems they bring for evaluation. The setting offers a concentrated learning environment to sharpen clinical skills because of the many patients with various medical problems seen in a relatively short period. Keys to success in urgent care are organized evaluation of every patient and vigilance to the opportunity to intervene and make a significant difference in patient outcome.

Drug-induced meningitis. A case involving trimethoprim-sulfamethoxazole.

Drug-induced meningitis should be considered in differential diagnosis of meningeal irritation in patients receiving therapy with anti-infective, nonsteroidal anti-inflammatory, immunosuppressive, or other selected agents. This report describes a case of aseptic meningitis associated with use of trimethoprim-sulfamethoxazole in a patient without apparent underlying autoimmune disease. The patient recovered promptly after the offending agent was withdrawn. No specific treatment other than symptomatic and supportive care need be given. In all instances, however, infection must be excluded.

Screening for asymptomatic diseases in your patients. Practical tips for doing it right.

Ms. Smith is a 64-year-old white woman who comes to the office for a "check-up." She has had a slight "weight problem" and some "high blood pressure," but has been in otherwise good health. She is 64 inches tall, weighs 186 pounds, and her blood pressure is 145/90. At the conclusion of an otherwise normal exam, the topic of health screening regarding breast cancer comes up. She declines a mammogram stating that she checks herself "pretty often" and that no other physician has ever felt lumps. Besides, she is "too old to worry about getting mammograms now," and one of her best friends told her that mammograms "really hurt bad."

Screening for prostate cancer. Does it make a difference?

Susan's father, Sidney Smith, is 63 years old. Recently he has heard on radio and television talk shows that a new test, the Prostate Specific Antigen (PSA), is now available to check for prostate cancer. During his general check-up visit to your office, he mentions this test and wants to know more. He is in excellent health and his urinary review of systems reveals only a slight decrease in the intensity of his urinary stream. On examination he has moderate prostate enlargement but no palpable nodules. His stool test is Hemoccult negative. The remainder of his examination is normal.

The preparedness of Hong Kong medical students towards advance directives and end-of-life issues.

OBJECTIVES: To explore the preparedness of medical students towards advance directives and related end-of-life issues, and to examine background factors such as knowledge, attitudes, and experience concerning advance directives and related end-of-life issues. METHODS: In 2007, 448 medical students in years 3 to 5 were surveyed at the Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong. Their knowledge, attitudes, and experiences of advance directives and related end-of-life issues, and their self-perceived preparedness to discuss these matters with patients were evaluated. RESULTS: A total of 220 (49%) of the eligible students responded, of whom 79% supported the use of advance directives. Only 65 (30%) students were certain of what advance directives meant and 198 (90%) students felt that their knowledge of advance directives was inadequate. Also, 197 (90%) students felt unprepared about advance directives and end-of-life issues. Factors associated with positive attitude towards advance directives included religion and knowledge. No factors were found to be associated with self-perceived preparedness towards advance directives or end-of-life issues. CONCLUSIONS: Most of the medical students surveyed demonstrated a positive attitude towards advance directives and recognised the importance of advance directives. However, they felt that they were unprepared and lacking in knowledge and experience of advance directives and end-of-life issues. Wider range and more depth of education is needed to better equip medical students for future practice.