A clinical and biological review of keratoacanthoma.

Keratoacanthoma (KA) is a common skin tumour that remains controversial regarding classification, epidemiology, diagnosis, prognosis and management. Classically, a KA manifests as a rapidly growing, well-differentiated, squamoid lesion with a predilection for sun-exposed sites in elderly people and a tendency to spontaneously regress. Historically, KAs have been considered a variant of cutaneous squamous cell carcinoma (cSCC) and are often reported as KA-type cSCC. However, the penchant for regression has led many to categorize KAs as biologically benign tumours with distinct pathophysiological mechanisms from malignant cSCC. The clinical and histopathological similarities between KA and cSCC, particularly the well-differentiated variant of cSCC, have made definitive differentiation difficult or impossible in many cases. The ambiguity between entities has led to the general recommendation for surgical excision of KAs to ensure a potentially malignant cSCC is not left untreated. This current standard creates unnecessary surgical morbidity and financial strain for patients, especially the at-risk elderly population. There have been no reports of death from a definitive KA to date, while cSCC has an approximate mortality rate of 1·5%. Reliably distinguishing cSCC from KA would shift management strategies for KAs towards less-invasive treatment modalities, prevent unnecessary surgical morbidity, and likely reduce associated healthcare costs. Herein, we review the pathophysiology and clinical characteristics of KA, and conclude on the balance of current evidence that KA is a benign lesion and distinct from cSCC.

Comparison of Food Intake Among Infants and Toddlers Participating in a South Central Texas WIC Program Reveals Some Improvements After WIC Package Changes.

In 2009, WIC began issuing revised food packages with the intent of improving dietary practices such as breastfeeding, delaying the introduction of complementary foods until about 6 months, limiting juice intake, and increasing intake of fruits, vegetables, whole grains, and baby food meats as appropriate for age. This observational study investigated whether dietary intake and feeding practices of a sample of majority-Hispanic infants and toddlers participating in a WIC clinic in south central Texas improved after the package changes. Feeding practices data and 24-h recalls were collected during telephone interviews with 84 caregivers of infants (4-12 months) and toddlers (1-2 years) in 2009 before the package change and with 112 caregivers in 2011 after the package change. The Nutrition Data System for Research was used to collect 24-h recalls. Outcomes for the two study years were compared using Chi square analysis for categorical and Mann-Whitney U analysis for continuous variables. Breastfeeding initiation, breastfeeding duration, age of introduction of complementary foods, and exposures to baby food fruits, vegetables, and meats among infants did not improve after the package changes. Significantly fewer infants received cereal in their bottles and fewer toddlers consumed vegetables and eggs after the package changes. The observed feeding practices of infants and toddlers among this sample did not reflect the WIC package changes. Strategic and comprehensive breastfeeding and nutrition education are recommended. Package modifications such as adding eggs back to the toddler package and allowing more flexibility for purchasing fresh produce and baby foods may be warranted.

Impact of Home-Delivered Meals on Nutrition Status and Nutrient Intake among Older Adults in Central Texas.

OBJECTIVE: This study aimed to measure changes in nutrition risk and nutrient intake after older adults received home-delivered meals (HDM) for 3 months. DESIGN: This study used a pre-posttest study design, with data collected before and after 3 months of HDM services. SETTING: Two HDM programs that serve the metropolitan areas of Austin and San Antonio, Texas. PARTICIPANTS: Study participants were aged 60 years or older, without dementia or terminal illness, and receiving HDM in Austin, Texas and San Antonio, Texas for 3 months. MEASUREMENTS: The Nutrition Screening Initiative (NSI) and Mini Nutrition Assessment-Short Form (MNA-SF) were used to assess nutritional risk. The National Cancer Institute Diet History Questionnaire II (DHQ II) was used to assess nutrient intake over the past month. RESULTS: After receiving 3 months of HDM, nutrition status significantly improved as measured by the NSI and MNA-SF. More participants met or exceeded the recommended dietary allowances (RDA) for magnesium and zinc after receiving HDM compared to before receiving HDM. Dietary supplement intake was associated with a higher nutritional risk. CONCLUSION: Improvements in nutrition status were found after 3 months of receiving HDM, whereas intake of most nutrients did not change significantly. Results of this study provide further evidence that HDM can reduce nutritional risk of older adults, and may inform HDM programs on the differences of NSI and/or MNA-SF to assess nutritional risk of clients.

Uses and limitations of exercise Doppler echocardiography in the diagnosis of ischemic heart disease.

This study tested the hypothesis that coronary artery disease might be identified by a decrease in Doppler measurements of flow velocity and acceleration. The response of aortic blood flow velocity and acceleration to exercise was determined in 102 subjects (28 young control subjects and 74 older patients) who underwent continuous wave Doppler echocardiographic examination before, during and immediately after near maximal treadmill exercise. Patients were grouped according to the results of thallium perfusion imaging: Group I = normal, Group II = ischemia with or without prior infarction and Group III = prior infarction only. A significant decrease in the level of velocity and acceleration achieved with exercise was observed both in patients in Group I (normal thallium study) (1.2 +/- 0.3 m/s and 36.8 +/- 14 m/s per s, p less than or equal to 0.005) and in patients in Group II (ischemia) (1.1 +/- 0.3 m/s and 27.7 +/- 11 m/s per s, p less than or equal to 0.0005) compared with values in young control subjects (1.4 +/- 0.2 m/s and 52.7 +/- 16 m/s per s). When groups of patients of similar age who differed in the presence (Group II) or absence (Group I) of ischemia on thallium scintigraphy were compared, no difference was found for maximal velocity (1.1 +/- 0.3 versus 1.2 +/- 0.3 m/s, p = NS), but acceleration was significantly lower in Group II (27.7 +/- 11 versus 36.8 +/- 14 m/s per s, p less than or equal to 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of magnetic resonance imaging and echocardiography in determination of cardiac dimensions in normal subjects.

No data exist regarding the ability of magnetic resonance imaging to assess cardiac size and performance in human beings. Therefore, measurements of cardiac dimensions by magnetic resonance imaging were compared with those obtained by two-dimensional echocardiography in 21 normal subjects. Magnetic resonance transverse cardiac sections were obtained during electrocardiographic gating using a spin echo pulse sequence. In normal subjects, magnetic resonance imaging yielded a range of values for cardiac dimensions having a similar standard deviation as that of two-dimensional echocardiography. Diastolic measurements of the aorta, left atrium, left ventricle and septum obtained by magnetic resonance imaging correlated well with those obtained by two-dimensional echocardiography (r = 0.82, 0.78, 0.81 and 0.75, respectively). The correlation coefficient of r = 0.35 observed for the posterior wall thickness was not surprising in view of the narrow range of normal values. Only a general correlation (r = 0.53) existed for the right ventricular diastolic dimension; this was probably related to the difficulty in obtaining representative measurements due to the complex geometry of this chamber. Failure of systolic dimension measurements by magnetic resonance imaging to correlate with those obtained by echocardiography is probably related to limitations of electrocardiographic gating, especially of determining the exact end-systolic frame. Although technically complex at present, magnetic resonance imaging does provide an additional noninvasive technique for measurement of cardiac size.

Assessment of left ventricular diastolic function: comparison of Doppler echocardiography and gated blood pool scintigraphy.

Although left ventricular diastolic filling patterns can be examined by both Doppler velocity recordings and gated blood pool scintigraphy, few data exist regarding a comparison of these techniques. Therefore, Doppler echocardiography and scintigraphy were compared in 25 patients. Pulsed Doppler echocardiography was performed using an apical four chamber view with the sample volume at the level of the mitral anulus. Doppler measurements included peak velocity of the early diastolic filling wave, time to peak early diastolic velocity from both end-systole and end-diastole, diastolic time period and diastolic integrated velocity (early, atrial and total). The cross-sectional area of the mitral anulus and the left ventricular end-diastolic volume were estimated from measurements made on the apical four chamber view. Scintigraphic measurements included normalized peak filling rate, time to normalized filling rate from both end-diastole and end-systole, diastolic time period and relative diastolic filling during early and atrial filling. Doppler echocardiography and scintigraphy compared favorably in assessment of fractional filling during early diastole (r = 0.84) and atrial systole (r = 0.85), ratio of early to atrial filling (r = 0.83), diastolic filling period (r = 0.94) and interval from end-diastole to peak early diastolic flow (r = 0.88). Normalized peak filling rate and time to normalized peak filling rate from end-systole did not correlate closely by these two techniques. The differences in normalized peak filling rate may be explained by difficulties in estimating mitral anulus cross-sectional area and left ventricular end-diastolic volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of the human right ventricular pressure-volume relation: effect of dobutamine and right coronary artery stenosis.

Right ventricular function was assessed in 15 patients using right ventricular pressure-volume loops. Right ventricular pressure using a micromanometer-tipped catheter, thermodilution cardiac output and gated blood pool scintigrams were simultaneously obtained. To help isolate the right ventricle, a slant hole collimator was used. The measurements were repeated during dobutamine infusion, which was titrated so there was minimal change in systemic pressure and heart rate. The right ventricular pressure-volume loop resembles the usual left ventricular loop except that the isovolumic contraction phase is often not as distinct, and right-sided ejection may continue well beyond right ventricular peak systolic pressure. Systolic but not diastolic function improved with dobutamine administration. There was no significant difference in right ventricular systolic function (ejection fraction, stroke work index, stroke volume index and cardiac index) or in end-diastolic volume index between patients without (Group I) and with (Group II) significant right coronary artery stenosis. However, there was a small but significant difference in right ventricular end-diastolic pressure (5.3 +/- 2.5 and 8.1 +/- 1.8 mm Hg [p less than 0.05]) for Group I and II, respectively. Thus, the right ventricular pressure-volume loop can be used to graphically display right ventricular function and improvement in contractility with dobutamine. The right ventricular isovolumic contraction phase and ejection phase differ from those in the usual left ventricular loop. Although there was a small difference in right ventricular end-diastolic pressure in patients with and without right coronary artery stenosis, the right ventricular pressure-volume loop did not provide additional discriminatory information between these two groups of patients.

Effect of zinc supplementation on plasma high-density lipoprotein cholesterol and zinc.

The recent report by Hooper PL, et al. (JAMA 1980;244:1960-1) that pharmacological doses (160 mg) of zinc lowered high-density lipoprotein (HDL)-cholesterol in men and that zinc might be an atherogenic agent prompted this report of the effect of zinc supplementation on HDL-cholesterol in women. Four levels of zinc supplements (0, 15, 50, or 100 mg/day) were given to 32 women for 8 wk. Fasting plasma HDL-cholesterol and zinc were measured at biweekly intervals. Plasma zinc increased in the supplemented groups, peaked at wk 4, then decreased toward initial values. The decline in plasma zinc regardless of continuing zinc administration may reflect a homeostatic response. No significant differences were seen in HDL-cholesterol over the 8 wk except in the 100 mg group at wk 4 when a transient decrease, -8.4% (57 to 48 mg/dl, p less than 0.04) was observed. Thus we conclude that in women the reduction in HDL-cholesterol in response to the pharmacological doses of zinc used in this study was transient and not dose-related.

The effect of hypoxia on thallium kinetics in cultured chick myocardial cells.

To assess the effect of hypoxia on cellular thallium-201 (201Tl) uptake and washout independent of coronary flow, we studied thallium kinetics during normoxia and hypoxia in cultured chick ventricular cells. Monolayers of contracting ventricular cells grown on coverslips were placed in a chamber and perfused to asymptote with media containing 201Tl. Perfusates were equilibrated with 5% CO2-95% air or 5% CO2-95% nitrogen for normoxia and hypoxia, respectively. Washout thallium kinetics were then observed during perfusion with unlabeled media. Twenty paired experiments were performed, randomly alternating the sequence of normoxia and hypoxia. Pharmacokinetics for thallium were determined by computer using standard formulae. Thallium uptake and washout were best described by assuming that intracellular thallium was contained within a single compartment. Cellular thallium uptake, as well as transfer rate constants for thallium uptake and for thallium washout during normoxia and hypoxia, were compared using paired t-tests. During normoxia and hypoxia, respectively, thallium uptake was 22 +/- 7% and 19 +/- 7% of asymptote (p less than 0.01); the compartmental rate constant for uptake by the cell was 0.16 +/- 0.07 min-1 and 0.15 +/- 0.06 min-1 (N.S.); and the transfer rate constant for washout from the cell was 0.26 +/- 0.06 min-1 and 0.23 +/- 0.05 min-1 (p less than 0.01). We conclude that there was a small (14%) decrease in thallium uptake during hypoxia. The rate of thallium uptake and washout was slightly less during hypoxia, although only the rate of washout was significantly less. These data show that cellular accumulation of thallium and the rate of washout of thallium were minimally decreased by hypoxia independent of blood flow.

Scintigraphic prediction of pulmonary arterial systolic pressure by regional right ventricular ejection fraction during the second half of systole.

In 49 patients in whom gated equilibrium ventriculography and cardiac catheterization were performed within a 6 day interval, total and fractional portions of global and regional right ventricular ejection fraction (RVEF) were correlated with pulmonary arterial systolic pressure. Pulmonary arterial systolic pressure was normal (30 mm Hg or less) in 27 patients (Group I) and elevated (31 mm Hg or greater) in 22 patients (Group II). The second-half regional RVEF was 38 +/- 8% (mean +/- standard deviation) with a range of 30 to 54% for Group I and 22 +/- 6% with a range of 13 to 32% for Group II. The difference between the means was statistically significant (p less than 0.001). Use of a second-half regional RVEF of 30% as the criterion of elevated pulmonary arterial systolic pressure resulted in a sensitivity of 0.86 and a specificity of 1.00. A power curve fit in which pulmonary arterial systolic pressure = 10.91 (second-half regional RVEF)-0.87 allowed accurate estimation (r = -0.85) of pulmonary arterial systolic pressure from the second-half regional RVEF. It is concluded that second-half regional RVEF may be used to accurately detect pulmonary arterial hypertension and to estimate its extent.

Measurement of infarct size using single photon emission computed tomography and technetium-99m pyrophosphate: a description of the method and comparison with patient prognosis.

The application of dual tracer transaxial emission computed tomography of the heart was studied with use of technetium-99m pyrophosphate and technetium-99m-labeled red blood cells for measuring infarct size in 20 patients with acute myocardial infarction and 10 without infarction. Imaging was performed with a standard gamma camera and with a multidetector transaxial emission computed tomographic body scanner 3 hours after injection of technetium-99m pyrophosphate. Immediately after the scanning procedure, technetium-99m pertechnetate was injected to label red blood cells, and the scanning protocol was repeated. Technetium-99m pyrophosphate was detected in the anterior wall with involvement of the interventricular septum or lateral wall in patients with electrocardiographic criteria for anterior infarction, whereas uptake was detected in the diaphragmatic left ventricular wall with involvement of the posterior, posteroseptal or posterolateral left ventricle or of the right ventricle in patients with electrocardiographic criteria for inferior or posterior infarction. Infarct size measured from transaxial images ranged from 14.0 to 117.0 g in weight. There was a direct relation between infarct size and patient prognosis in that, of the 13 patients with infarct greater than 40 g, 11 (85 percent) had complications, whereas only 2 (29 percent) of 7 patients with an infarct less than 40 g had complications during a follow-up period averaging 17.8 months (p less than 0.05).

Effects of the Clarion Electrode Positioning System on auditory thresholds and comfortable loudness levels in pediatric patients with cochlear implants.

OBJECTIVE: To evaluate the effects of using the Electrode Positioning System on psychophysical auditory thresholds, most comfortable loudness levels, and electric auditory brainstem response (EABR) thresholds in children with the Clarion version 1.2 cochlear implant. DESIGN: Retrospective analysis. SETTING: Academic tertiary care center. PATIENTS AND METHODS: Clinical records of a series of 25 children who received the Clarion version 1.2 cochlear implant at the University of Minnesota, Minneapolis, between January 1997 and August 1999 were examined. Measures evaluated were psychophysical thresholds (T-levels) and most comfortable loudness levels (M-levels) obtained at the 3-month posthookup audiologic evaluation and EABR thresholds obtained during implant surgery. Relevant threshold measures were available for 24 patients, 11 of whom had received the Clarion spiral electrode and electrode positioner (EP group) and 13 of whom had received the spiral electrode without positioner (non-EP group). The 3 measures (T-levels, M-levels, and EABR thresholds) were compared across groups. In addition, EABR thresholds were compared with T-levels and M-levels within groups. RESULTS: Mean T-levels and M-levels were significantly lower for the EP group than for the non-EP group, and interpatient variability for these measures was considerably smaller in the EP group. Electric auditory brainstem response thresholds were not significantly different for EP vs non-EP patients; however, EABR data were available for only a few non-EP patients. CONCLUSIONS: Use of the electrode positioner results in lower T-levels and M-levels in children with the Clarion version 1.2 cochlear implant, consistent with results of previous studies in adults, and reduces across-patient variability for these measures. It is unclear from the present data whether use of the electrode positioner systematically reduces intraoperative EABR thresholds.

Myocardial oxygen tension and capillary density in the isolated perfused rat heart during pharmacological intervention.

Oxygen is essential for normal cardiac function and plays an important role in cardiac regulation. Electron paramagnetic resonance (EPR) oximetry appears to have some significant advantages for measuring oxygen tension (pO2) in the beating heart. This study presents the serial measurement of myocardial pO2 by EPR oximetry in the isolated crystalloid perfused heart during treatment with different cardioactive drugs: dobutamine, metoprolol, verapamil, vasopressin, and N omega-Nitro-L-Arginine Methyl Ester (L-NAME). Baseline myocardial pO2 was 176 +/- 14 mmHg (mean +/- S.E.). Myocardial capillary density in the intact contracting heart was calculated to be 2300 +/- 100 mm-2, using local myocardial pO2 and a cylindrical model for oxygen diffusion in tissue. Each drug had characteristic effects on myocardial pO2, myocardial oxygen consumption (MVO2), and capillary density. Metoprolol and verapamil increased myocardial pO2 by 51% and 18%, respectively, dobutamine decreased myocardial pO2 by 84% while vasopressin and L-NAME had no significant effect on myocardial pO2. Metoprolol and verpamil decreased MVO2 by 9% and 56%, respectively, while dobutamine increased MVO2 by 59%. A quantitative comparison of effects on the capillary bed based on changes in myocardial pO2 and MVO2 was made. Metoprolol and verapamil had opposite effects on the capillary bed. Verapamil decreased myocardial capillary density by 39%, while capillary density increased by 10% (n.s.) with metoprolol. Data following perfusion without drug is also presented. We conclude that: 1) The application of EPR oximetry with LiPc provides dynamic evaluation of local myocardial pO2 in the contracting heart. 2) Using a cylindrical model of oxygen delivery and diffusion in tissue, these data may be used to describe the changes of capillary density during pharmacological interventions.

Hospital smoking policies: who enforces them?

As opprobrium is increasingly given to the act of smoking, many institutions--hospitals especially--are seeking to curtail the amount of smoking that occurs within their buildings through various policies. This, however, raises two necessary questions: What does policy enforcement mean? And who shall enforce the rules? The article below discusses the results of a survey of North Carolina hospitals that asked these questions and more.

Dietary treatment of hypercholesterolemia.

Diet is the first line of treatment for hypercholesterolemia. Patients should be encouraged to make simple and stepwise changes in their diets to lower elevated cholesterol levels. General dietary guidelines from the American Heart Association (AHA) Step-One Diet include limiting the amount of total fat to less than 30% of total calories, decreasing cholesterol intake to less than 300 mg/day, and adjusting caloric intake to levels required to attain or maintain ideal body weight. Diets must be individualized to meet therapeutic needs within the limits of the patient's abilities, knowledge, and motivation.