Setting environmental exposure standards: Current concepts and controversies

In the 1990s there will be a heightened emphasis on controlling environmental health hazards. This paper examines the nature and role of environmental standards. The process of setting exposure limits (i.e. standards) is discussed, with particular reference to quantitative risk assessment and to the complex scientific‐social‐political process of deciding on ‘acceptable’ levels of risk. The need for closer integration between epidemiology and toxicology is explored, as is the need for incorporation of biological markers in epidemiological research, particularly in order to improve the detection and quantification of small increases in risks to health caused by low‐level exposures to environmental toxins.     

Testicular cancer: current update and controversies

Testicular cancer is an important disease affecting young men. The overall 5-year survival has improved to 95%. The goal now is to maintain the efficacy of treatment in advanced disease while reducing the associated side effects.     

Vitamin supplements: current controversies.

Supplemental use of vitamins to prevent disease constitutes a major commercial enterprise in the United States. The efficacy of such use, or even the need for intakes above that which can be supplied by means of diet alone, has been the source of considerable controversy in the medical and scientific fields. Recently published data have given strong support to several of the claims for major benefits of disease prevention, including that of cancer, cardiovascular disease, carpal tunnel syndrome, and neural tube defects, to name just a few. The purported benefits for supplemental vitamin usage are discussed for these diseases, along with a call for a re-evaluation of the underlying philosophy of the Recommended Dietary Allowances, or consideration of their abolition, based on newly emerging data.     

The pharmaceutical management system at Shade Tree Family Clinic: a medical student-run free clinic's experience

The Shade Tree Family Clinic (STFC) is a student-run free walk-in health clinic opened by Vanderbilt University medical students in October 2005 to address the acute and chronic health needs of the underinsured community in East Nashville. STFC founders decided that the clinic would provide complete medical care, including dispensing commonly prescribed medications at no charge to patients. After several months of managing the inventory in a log book, a medical student author created a Web-based pharmaceutical tracking system to manage the medication formulary. In the process, the authors found little literature available addressing the logistics of setting up an electronic pharmacy system. The system created uses the freely available RxNorm and US Department of Veterans Affairs National Drug File Reference Terminology databases for medication and classification data. Incorporation of these databases allows medical students to dispense and restock medications with ease. The system ensures accurate data entry, improves efficiency, and facilitates continuity of care at a clinic staffed by hundreds of different students and physicians. The STFC pharmaceutical tracking system has facilitated the acquisition and efficient management of medications and consequently has had a great impact on the success of STFC.     

Outpatient clinic's staffing: a case study

Suggests that the traditional approach for establishing staffing levels in hospital systems is not feasible. Presents steps taken to study the staffing levels in an outpatient clinic of a central hospital. Puts forward recommendations for a periodic evaluation of staffing levels.     

Protein intake for athletes and active adults: Current concepts and controversies

The demands of physical exertion mean that protein requirements for athletes and active adults are now accepted as being greater than sedentary populations and those described by population reference intakes of ~0.8 g protein per kg of body mass per day (g/kg/day). Recent scholarly reviews and the latest guidelines for nutrition and athletic performance from the American College of Sports Medicine suggest intakes ranging from 1.2‐2.0 g/kg/day whether performing aerobic or resistance exercise, with the higher range of intakes appropriate for the latter. Specific situations of hypoenergetic diet or injury likely require greater protein intakes in order to preserve lean body mass (LBM), which is often paramount in athletes. The optimal dose of protein per meal is 0.25–0.40 g/kg when aiming to maximally stimulate muscle protein synthesis, a marker of repair, growth and adaptation, but multifactorial interactions between protein source, meal timing and pattern of distribution, and macronutrient co‐ingestion around exercise influence recommendations on a meal‐by‐meal basis. Longer term studies are required to confirm the efficacy of these recommendations, which are primarily inferred from data from acute (<24 hours) studies. Notwithstanding the positive effects on LBM of higher protein intakes combined with exercise, it would be remiss not to consider potential adverse effects of long‐term high‐protein intakes, although these concerns are rather preliminary at present. Therefore, within the broad framework of recommended ranges and being cognisant of overall energy and other macronutrient intakes, a personalised and periodised approach to nutrition is required depending on an individual's sport, training volume, phase and goals.     

Lacunar strokes: current concepts

Lacunar strokes result from occlusion of penetrating arteries in the deeper, subcortical parts of the cerebrum and brain stem. Approximately 19 percent of all strokes are of the lacunar variety with lacunar strokes representing the most common cerebrovascular complication of chronic hypertension. Four major clinical syndromes are pure motor hemiparesis, pure sensory stroke, ataxic hemiparesis, and the dysarthria-clumsy hand syndrome. The advent of computed tomography (CT) has allowed the antemortem study of lacunar disease and has shed new light on the pathogenesis and clinical course of lacunar strokes. Recently, it has been demonstrated that lacunar strokes may be embolic or hemorrhagic in causation, are not invariably associated with hypertension, and may be larger and associated with hypertension, and may be larger and associated with neurological manifestations that do not conform to the classic patterns. In most instances, however, recognition of the characteristic clinical presentation and confirmation of the diagnosis with noninvasive studies spare many patients unnecessary risks associated with anticoagulation, arteriography, or vascular surgery.     

Sarcoidosis: current concepts and case reports

Sarcoidosis is a systemic granulomatous disease of unknown etiology associated with various immune alterations and biochemical changes. This article reports recent advances in the conceptualization of the immune dysfunction with emphasis on helper T-cell overactivity in the lungs. Because 90 percent of patients with sarcoidosis have intrathoracic disease, the mode of presentation, radiographic findings, clinical course, and treatment of pulmonary involvement are discussed. Case reports are used to demonstrate the typical course of the disease and generally favorable outcome of the vast majority of patients seen in the non-referral setting. A rare case of neurosarcoidosis with neuroendocrine features is presented.     

Mercury exposure and early effects: an overview

OBJECTIVES: This paper was given as a keynote address at the conference on The Assessment of the Effects Due to Low Doses of Inorganic Mercury following Environmental and Occupational Exposures: Human and in vitro Studies on the Specific Mechanisms of Toxicity in Gargnano, Italy, in September 2001. METHODS: The most relevant literature over the past 40 years has been reviewed, and in particular, the proceedings of the World Health Organisation conferences on the health effects of inorganic and organic mercury exposure have been considered. RESULTS: In an uncontaminated environment the general population is exposed to mercury vapour from the atmosphere and from dental amalgam, while the diet, mainly from fish, is the principal source for methyl mercury absorption. Mercury vapour release from amalgam fillings increases with chewing, with absorption and uptake by the brain and kidneys. Infants exposed to phenyl mercury from treated diapers and young children ingesting mercurous chloride in teething powders have developed acrodynia (pink disease), and Kawasaki disease and the use of mercurial skin lightening creams has been followed by the development of the nephrotic syndrome. Both mercury compounds and mercury vapour have given rise to contact dermatitis in the general population. Epidemics of mercury poisoning have followed release of mercury into the environment from industrial activity, with uptake of methyl mercury from fish eating in Minamata Bay and uptake of both inorganic and methyl mercury following release of mercury vapour and deposition into waterways from gold recovery procedures in the Amazon basin. The ingestion of wheat and barley seed treated with an alkyl mercury fungicide for sowing, by a largely illiterate population in Iraq, led to a major outbreak of poisoning with a high fatality rate. Following exposure to mercury vapour, the earliest clinically observed adverse effects at urine mercury levels of the order of 30-100 mg/g creatinine, are objectively detectable tremor, psychological disorder and impaired nerve conduction velocity in sensitive subjects, with subjective symptoms of irritability, fatigue and anorexia. At these and at lower levels, proteinuria has also been observed. Both glomerular and tubular damage may occur at exposure levels lower than those giving rise to central nervous system effects. An immunological effect has also been observed in studies on clinically asymptomatic workers with low level exposure. CONCLUSIONS: As mercury can give rise to allergic and immunotoxic reactions which may be genetically regulated, in the absence of adequate dose-response studies for immunologically sensitive individuals, it has not been possible to set a level for mercury in blood or urine below which mercury related symptoms will not occur.     

Diabetes mellitus: current concepts in diagnosis, classification and coding

Diabetes mellitus (DM) is a chronic disorder of metabolism, which is commonly found in the Puerto Rican population. In this article the current concepts in diagnosis, classification and correct coding of DM are discussed. Since the cutoff point for diagnosing DM was lowered to 126 mg/dl in a fasting plasma glucose levels, many persons may be undiagnosed unless physicians are aware of this fact. Once diagnosed, strict control of the disease is mandatory to prevent the chronic diabetic complications. It is very important to classify and code the persons with DM accurately. This practice will help researchers, physicians, health insurance managers and other persons to assess the prevalence of DM and its complications. This will eventually lead to better management of this important disease.     

Glucose control guidelines: current concepts

The Diabetes Control and Complications Trial (DCCT) ended decades of controversy regarding the necessity of tight glycemic control for type 1 diabetes by demonstrating that glucose control using intensive insulin therapy significantly reduced long-term microvascular complications. The American Diabetes Association (ADA) guidelines empirically support the same goal of attempting to obtain normoglycemia in patients with type 2 disease; however, unlike in type 1 disease, insulin is a tertiary option, following diet, exercise, and oral agents. Emerging long-term intervention data in type 2 diabetes suggest that insulin may pose increased cardiovascular risk in this already 'at-risk' population. However, many type 2 diabetics will eventually require insulin. Clearly, more studies are warranted to assess the risks, benefits, and feasibility of improved glycemic control in type 2 diabetes. Nonetheless, two principles are clear. First, promoting blood glucose levels approaching normoglycemia is an important factor in preventing long-term microvascular complications. Second, type 2 diabetes comprises numerous metabolic conditions; therefore an integrated effort by the patient and healthcare team is required to optimize blood glucose and serum lipid levels and minimize cardiovascular risk factors.     

Meconium aspiration syndrome: current concepts

Aspiration of meconium causes considerable perinatal morbidity and mortality. Meconium-stained amniotic fluid (MSAF) is present in 7-22% of all deliveries. Gastrointestinal secretions, bile, bile acids, mucus, pancreatic juice, cellular debris, amniotic fluid, swallowed vernix caseosa, lanuge, and blood comprise meconium. Passage of meconium occurs most often in deliveries after 42 weeks gestation (30%) because of high levels of the hormone motilin. This hormone is responsible for bowel peristalsis, defecation, and maturation of the innervation of the intestinal tract associated with vagal stimulation. It tends to be a marker of pre/intrapartum asphyxia. MSAF is also a sign of fetal hypoxia or acidosis. It appears that meconium aspiration is predominantly an intrauterine event. The definition of meconium aspiration syndrome (MAS) is respiratory distress in a meconium-stained newborn, compatible radiographic findings (e.g., coarse, irregular pattern of increased density throughout the lung), and symptoms that can not otherwise be explained. MAS occurs in 1-4% of infants with MSAF and up to 10% of those with thick meconium. Mortality ranges from 6% to 40%. Initially, meconium particles mechanically obstruct the small airways. Later, chemical pneumonitis and interstitial edema are responsible for small airway obstruction. As many as 66% of persistent pulmonary hypertension of the newborn cases are associated with MAS. Clinical signs and symptoms of MAS include frothy, yellow-green secretions from the mouth; very rapid breathing; intercostal retractions; cyanosis; overinflated chest due to air trapping; rales; and rattling in the throat. Transcervical amnio-infusion of warmed normal saline may be an obstetric intervention in cases of MSAF. Intrapartum oropharyngeal suctioning and postpartum intratracheal suctioning has reduced the incidence of MAS. Routine care of MAS infants includes monitoring and correcting of the thermal environment and blood glucose and calcium levels. Chest physiotherapy, saline lavage, management of hypoxemia, surfactant therapy, and systemic steroid treatment are MAS therapies.     

International health: various current concepts

This study is a theoretical approach on international health with the purpose to point out some aspects which can enhance the understanding of the International Health field and its operational and conceptual elements in the socio-economic process of integration of neighboring countries.