Emmert's law in the dark: active and passive proprioceptive effects on positive visual afterimages.

The relationship between apparent size and apparent distance is given by Emmert's law, which states that a retinal image is proportional in size to the distance of the surface it is projected upon. This principle also applies to retinal afterimages in that they, too, will change in apparent size if distance cues suggest that the location of the object onto the retinal image has been altered. It has also been known for some time that non-retinal cues can produce quantitative and qualitative effects on an afterimage when it is viewed in the dark. In the present two studies, positive afterimages of an observer's hand, as well as objects held by that hand, were used as targets to investigate the effects on size-constancy scaling of moving the hand to and fro along the line of sight for different distances in the dark. Results show that, when observers focus on a held object, the changes in size predicted by Emmert's law occur in response to both active and passive proprioceptive or haptic cues. The most intriguing result consisted of the finding that, when only the hand is the target, there appears to be a limit to the decrease in apparent hand size. It appears that the visual system 'refuses' to size-scale the hand below a limit it accepts as representative or acceptable of 'its' hand.

Diagnosis and management of gout.

Gout is a disease resulting from the deposition of urate crystals caused by the overproduction or underexcretion of uric acid. The disease is often, but not always, associated with elevated serum uric acid levels. Clinical manifestations include acute and chronic arthritis, tophi, interstitial renal disease and uric acid nephrolithiasis. The diagnosis is based on the identification of uric acid crystals in joints, tissues or body fluids. Treatment goals include termination of the acute attack, prevention of recurrent attacks and prevention of complications associated with the deposition of urate crystals in tissues. Pharmacologic management remains the mainstay of treatment. Acute attacks may be terminated with the use of nonsteroidal anti-inflammatory agents, colchicine or intra-articular injections of corticosteroids. Probenecid, sulfinpyrazone and allopurinol can be used to prevent recurrent attacks. Obesity, alcohol intake and certain foods and medications can contribute to hyperuricemia. These potentially exacerbating factors should be identified and modified.

Near-drowning.

Near-drowning and drowning are major causes of neurologic injury and death in young persons. Most victims aspirate water, and pulmonary edema develops in many of these cases. Prolonged submersion causes cerebral asphyxia and adversely affects the brain within five minutes. Immediate ventilation and oxygenation are essential in the reversal of cerebral anoxia. During field resuscitation, precautions should be taken to protect the cervical spine because of the possibility of injury. The Heimlich maneuver is used only after unsuccessful attempts at ventilation suggest foreign-body obstruction. Prehospital advanced cardiac life support with tracheal intubation is indicated in patients with severe injuries. On arrival at the hospital, ventilation with continuous positive airway pressure or positive end-expiratory pressure enhances pulmonary function. Many water submersion accidents are avoidable; close supervision of infants and toddlers, installation of a fence around home swimming pools, and abstinence from alcohol during participation in water sports are some practical precautions.

Delirium in the elderly patient.

Delirium is characterized by a sudden deterioration in cognitive function and an inability to sustain attention. It is a medical emergency that occurs in more than 20 percent of hospitalized elderly patients. Misdiagnosis is common and contributes to high morbidity and mortality. Patients may present in hypoactive, hyperactive or mixed states. Frail elderly patients are at greatest risk of delirium, especially those with dementia and multiple medical problems. Clinical history, physical examination and laboratory testing determine the most likely etiologies, such as medications (especially drugs with anticholinergic potential), infections and electrolyte disturbances. Effective management requires prompt treatment of the underlying pathology and maintenance of a supportive environment. It is often necessary to control agitation and prevent the complications of immobility in elderly patients with delirium. Although the long-term prognosis is guarded in elderly patients with delirium, sound geriatric care and a high index of suspicion can minimize the impact of delirium.

Heat emergencies.

Heat emergencies occur when the body is unable to adequately dissipate heat. Hyperthermic patients should be cooled immediately with a lukewarm-water spray and cool moving air. Patients with heat exhaustion respond well to administration of intravenous fluids. Patients with heatstroke have a complete loss of thermoregulation, a core temperature greater than 40.5 degrees C (105 degrees F) and impaired mental status. These critically ill patients must be cooled quickly to 39 degrees C (102 degrees F) to avoid devastating complications. Intensive care monitoring and support are indicated. To reduce the risk of heat injury in hot weather, frail and elderly persons must maintain hydration and may need to consider alternate living arrangements. Laborers, athletes and military personnel benefit from gradual acclimation to the heat, increased fluid intake, vapor-permeable clothing and frequent rest periods.

Safety belt education using visual crash images and low-cost incentives.

Automobile safety belt use among teen-agers remains low despite high crash morbidity and mortality. This article describes a model of a community-based safety belt promotional program. Ten public high schools, with student club and administrative support, were selected from across Mississippi. Safety belt assemblies, which created vivid crash images, were conducted using police officers, ambulance personnel, people with paraplegia, football players, and others. Low-cost incentives were awarded to buckled students over a 10-week period. Implementation of the program resulted in a mean increase of 21% in male safety belt use and 17% in female safety belt use. Concepts used in the program are reproducible, at minimal cost, by using personnel found in most communities.

Health promotion and disease prevention: a survey of rural family physicians.

Family and general practice physicians deliver comprehensive health care over time and are well suited to promote health and prevent disease. Prior studies of preventive medicine routines have tended to address a limited number of the recommended practices. The purpose of this study was to: (1) estimate the level of primary care physician compliance with the wide range of physician recommendations in Healthy People 2000: National Health Promotion and Disease Prevention Objectives for the Year 2000 and (2) identify practice characteristics associated with performance of preventive health care. Full-time family and general practice physicians, located in rural Mississippi towns of 5,000 to 10,000, were selected for the study. Of 94 eligible physicians, 81 were surveyed (73 surveys completed on site and 8 surveys returned by mail). The physicians treated a mean of 35 patients per day, with a disproportionate number of elderly patients. Limited physician time was ranked by physicians as the greatest obstacle to preventive medicine. Physicians were found to practice more preventive medicine in the adult and elderly patients than in the children and adolescents. Cancer, cardiovascular, and infectious disease risks were well addressed, with little attention directed toward occupational and environmental (e.g., lead, firearm, automobile) risks. Two practice characteristics were consistently associated with higher preventive medicine scores: an assigned preventive medicine staff member and preventive medicine flow charts. This information, obtained in a medically underserved area, may be used to assist physicians in meeting the Healthy People 2000 objectives. More research is needed to identify effective approaches for health risks that were not well addressed in physician offices.

Use of comprehensive geriatric assessment techniques by community physicians.

BACKGROUND: Research has shown that comprehensive assessment techniques have several clinical benefits for geriatric patients. The purpose of this study was to determine how frequently community practitioners used comprehensive geriatric assessment techniques to identify factors related to use of those techniques. METHODS: The study group included 54% of the 100 community-based family physician preceptors who participate in the University of Mississippi's family medicine training programs. On-site interviews were conducted in each physician's office to measure the percentage of physicians who performed comprehensive geriatric assessment. RESULTS: The majority of physicians employed some selected age-related assessment techniques, but less than 25% performed functional assessment techniques considered unique to the geriatric patient, such as mental status assessment and evaluation of activities of daily living. Most physicians' personal and practice characteristics were unrelated to the use of assessment techniques. CONCLUSIONS: Although many physicians use some techniques of geriatric assessment, most practicing physicians do not perform comprehensive assessment of geriatric patients.

Primary care physicians in Mississippi: implications for rural health care.

Despite a 24% increase in Mississippi primary care physicians during the 1980s, rural areas of the state continue to be underserved with 39 of 82 counties classified as health manpower shortage areas for primary medical care. Utilizing 1980 and 1990 census data and reports from the Mississippi State Department of Health, primary care physician manpower was analyzed to determine where growth and trends occurred. Most of the primary care physician growth occurred in ten populous counties, with family physicians and general practitioners continuing to provide most of the care in the lesser populated counties. Public and private entities are exploring new and innovative methods of delivering health care to rural areas which recognize the changing professional and lifestyle expectations of today's physicians. Multispecialty primary care group practices need to be promoted and innovative financial arrangements provided. Educational systems need to recruit students from rural areas and provide more training experiences in rural areas.

Tyromycin A: a novel inhibitor of leucine and cysteine aminopeptidases from Tyromyces lacteus.

Tyromycin A, a new inhibitor of leucine and cysteine aminopeptidases has been isolated from mycelial cultures of the basidiomycete Tyromyces lacteus (Fr.) Murr. Its structure was established as 1,16-bis-[4-methyl-2,5-dioxo-3-furyl]hexadecane (1) by spectral analysis and transformation into ester and imide derivatives.

Chemical dependence. Analysis of work absenteeism and associated medical illnesses.

Workers with a medical diagnosis of chemical dependence were selected and compared with matched controls; we hypothesized there were significant differences in absenteeism and certain medical illnesses. Employee data were obtained from medical insurance sickness and accident reports. Illnesses were summarized into diagnostic clusters for analysis. Chemically-dependent workers had significantly more (P less than .05) absenteeism, injuries hypertension, and mental disorders than did the control group. Using these findings, employers can conduct prospective studies that select workers to be screened for chemical dependence.

The role of the rural hospital emergency department.

Although rural hospital emergency departments are key components of rural health care, there is little medical literature describing their activities. This study examined the patient load of rural emergency departments in Mississippi. Each patient encounter was coded according to public health district, hospital number, patient number, age, sex, race, season, day of week, time, diagnosis, disposition, and method of payment (if available). The rural emergency departments were much busier when physician offices were closed, with the vast majority of patients being treated and sent home. Users of rural emergency departments had similar diagnoses and dispositions to users of urban emergency departments. Admitted patients tended to be older; almost one half of the patients transferred to other institutions had injuries. The findings have implications for the training of rural physicians and for policies relating to rural health care delivery.

Antibiotics from basidiomycetes. XXXVII. New inhibitors of cholesterol biosynthesis from cultures of Xerula melanotricha Dörfelt.

Three new inhibitors of cholesterol biosynthesis have been isolated from cultures of Xerula melanotricha and their structures elucidated by spectroscopic methods. Dihydroxerulin (1) in admixture with xerulin (2) strongly inhibits the incorporation of 14C- acetate into cholesterol in HeLa cells while the incorporation of 14C-mevalonate is not affected. Xerulinic acid (3) shows similar biological activities but a higher cytotoxicity.

Strobilurin D and strobilurin F: two new cytostatic and antifungal (E)-beta-methoxyacrylate antibiotics from Cyphellopsis anomala (1).

Strobilurin D and strobilurin F, two new cytostatic and antifungal antibiotics of the (E)-beta-methoxyacrylate class, have been isolated from mycelial cultures of the basidiomycete Cyphellopsis anomala (Pers. ex Fr.) Sing. The structures were elucidated by spectroscopic methods. The antibiotics inhibit the growth of human and animal cells and a wide variety of fungi. Like strobilurins A and B, the new metabolites are potent inhibitors of respiration.

Asperfuran, a novel antifungal metabolite from Aspergillus oryzae.

Asperfuran is a novel antifungal dihydrobenzofuran derivative produced by a strain of Aspergillus oryzae. Asperfuran weakly inhibited chitin synthase from Coprinus cinereus. This inhibition could be abolished by the addition of egg lecithin. In the agar diffusion assay asperfuran induced morphological changes in Mucor miehei at very low concentrations (20 ng/disc) while growth was only partly inhibited. In HeLa S3 and L1210 cells it showed weak cytotoxicity, the IC50 was 25 micrograms/ml.

Hospital emergency departments in Mississippi.

This paper is a descriptive study of hospital emergency departments in Mississippi. Hospital emergency departments are analyzed according to the number of patient visits per day and the services available. The data indicate that rapid access of a trauma patient to a high volume, broad service emergency department is difficult in much of the state. The authors encourage the state to utilize recommendations of the American College of Surgeons to develop a statewide emergency medical system. They maintain that such a system would better match existing resources with the needs of emergency patients.