Subcutaneous anterior hairline forehead rhytidectomy

An anterior hairline incision with subcutaneous (superficial to the frontalis muscle) dissection is recommended for certain categories of rhytidectomy patients. Patient selection is a very important preoperative procedure. The technique and results are described and illustrated. Advantages and disadvantages are discussed.     

3alpha-6alpha-Dihydroxy-7alpha-fluoro-5beta-cholanoate (UPF-680), physicochemical and physiological properties of a new fluorinated bile acid that prevents 17alpha-ethynyl-estradiol-induced cholestasis in rats

3alpha-6alpha-Dihydroxy-7alpha-fluoro-5beta-cholanoate (UPF-680), the 7alpha-fluorine analog of hyodeoxycholic acid (HDCA), was synthesized to improve bioavailability and stability of ursodeoxycholic acid (UDCA). Acute rat biliary fistula and chronic cholestasis induced by 17alpha-ethynyl-estradiol (17EE) models were used to study and compare the effects of UPF-680 (dose range 0.6-6.0 micromol/kg min) with UDCA on bile flow, biliary bicarbonate (HCO(3)(-)), lipid output, biliary bile acid composition, hepatic enzymes and organic anion pumps. In acute infusion, UPF-680 increased bile flow in a dose-related manner, by up to 40.9%. Biliary HCO(3)(-) output was similarly increased. Changes were observed in phospholipid secretion only at the highest doses. Treatment with UDCA and UPF-680 reversed chronic cholestasis induced by 17EE; in this model, UDCA had no effect on bile flow in contrast to UPF-680, which significantly increased bile flow. With acute administration of UPF-680, the biliary bile acid pool became enriched with unconjugated and conjugated UPF-680 (71.7%) at the expense of endogenous cholic acid and muricholic isomers. With chronic administration of UPF-680 or UDCA, the main biliary bile acids were tauro conjugates, but modification of biliary bile acid pool was greater with UPF-680. UPF-680 increased the mRNA for cytochrome P450 7A1 (CYP7A1) and cytochrome P450 8B (CYP8B). Both UDCA and UPF-680 increased the mRNA for Na(+) taurocholate co-transporting polypeptide (NCTP). In conclusion, UPF-680 prevented 17EE-induced cholestasis and enriched the biliary bile acid pool with less detergent and cytotoxic bile acids. This novel fluorinated bile acid may have potential in the treatment of cholestatic liver disease.     

Evidence-based review of three-dimensional conformal radiotherapy for localized prostate cancer: an ASTRO outcomes initiative

PURPOSE: To perform a systematic review of the evidence to determine the efficacy and effectiveness of three-dimensional conformal radiotherapy (3D-CRT) for localized prostate cancer; provide a clear presentation of the key clinical outcome questions related to the use of 3D-CRT in the treatment of localized prostate cancer that may be answered by a formal literature review; and provide concise information on whether 3D-CRT improves the clinical outcomes in the treatment of localized prostate cancer compared with conventional RT. METHODS AND MATERIALS: We performed a systematic review of the literature through a structured process developed by the American Society for Therapeutic Radiology and Oncology's Outcomes Committee that involved the creation of a multidisciplinary task force, development of clinical outcome questions, a formal literature review and data abstraction, data review, and outside peer review. RESULTS: Seven key clinical questions were identified. The results and task force conclusions of the literature review for each question are reported. CONCLUSION: The technological goals of reducing morbidity with 3D-CRT have been achieved. Randomized trials and follow-up of completed trials remain necessary to address these clinical outcomes specifically with regard to patient subsets and the use of hormonal therapy.     

Evaluation of prophylactic and therapeutic effects of silymarin on mebendazole-induced hepatotoxicity in cats

The aim of this study was to determine the protective action of silymarin on mebendazole-induced hepatotoxicity in cats. Twenty five healthy cats were randomly allotted into five equal groups. Cats in group A were given mebendazole (single dose 200?mg?kg, p.o.); group B consisted of cats that received silymarin (single dose 30?mg?kg, p.o.) concurrent with mebendazole administration; groups C, D and E were treated as group B, but silymarin was administered 2, 12 and 24?h after mebendazole administration, respectively. The serum concentrations of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and total and direct bilirubin were measured before mebendazole administration and 2, 12, 24 and 72?h later as indices of liver injury. A single oral administration of mebendazole significantly elevated serum concentrations of ALT, AST, ALP, LDH (in all cases), and total and direct bilirubin in one cat in group A, after 24?h (P?<?0.05). In groups B and C, levels of serum enzyme activities and total and direct bilirubin remained within normal values, but in group D, levels of serum enzyme activity (in four cases) were higher than normal values and total and direct bilirubin remained within the normal range. In group E, levels of serum enzyme activities (in all cats) and total and direct bilirubin (in one cat) were higher than normal values. In conclusion, silymarin can protect liver tissue against oxidative stress in cats with mebendazole intoxication particularly in the first 2?h after exposure.     

Sensitivity and specificity: imperfect predictors of guideline utility in radiology

Objective

Many “guideline-development studies” have presented the sensitivity (SN) and specificity (SP) of a new decision tool to describe the potential improvements in utilisation of imaging techniques as a result of adopting the new guideline. However, SN and SP are measures designed to assess how well a new guideline compares with a gold standard. These measures do not evaluate how many patients with a positive test actually have the disease; nor do they evaluate how many patients with a negative test do not have the disease. To evaluate these characteristics of a decision tool, other measures, namely the positive predictive value (PPV) and negative predictive value (NPV), should be calculated. This report highlights some of the main methodological challenges in interpretation of the studies that attempt to evaluate the development of an imaging guideline and the effectiveness of an imaging guideline in real world practice.

Methods

We define four key measures of a decision tool: SN, SP, PPV and NPV. Using data from two hypothetical populations, we explain how these measures can be calculated and interpreted. We place special emphasis on the purpose of and differences between the SN–SP and PPV–NPV.

Results

Borrowing information from two studies, we demonstrate how these measures should be used in the radiology healthcare services research to evaluate decision guidelines.

Conclusion

The use of appropriate measures for the specific question at hand will ensure the guidelines are useful, safe, cost reducing and effective clinical tools.Several studies have demonstrated a substantial increase in the use of imaging technology over the past two decades in developed countries [1-3]. This is particularly so in the United States, which has the highest per capita healthcare expenditure [4]. In a recent report to the United States Congress, the Government Accountability Office found that between 2000 and 2006, Medicare (a government programme of medical care targeting individuals ≥65 years old) spent more than $14 billion on imaging technology [1]. Despite this surge in utilisation pattern, studies have not been able to demonstrate a positive correlation between higher utilisation and better patient outcome [5]. In addition, there is substantial geographical heterogeneity in the utilisation of imaging technology [2, 5]. In 1994, Olsson and Inamura [2] compared annual radiology examinations between the Scandinavian countries and Japan. They demonstrated that the Japanese receive a substantially higher number of examinations in comparison with Scandinavians (1600 per 1000 individuals per year vs 600 per 1000 individuals per year). The greater availability of more advanced imaging technologies such as CT in Japan (1 scanner per 17 000) compared with Scandinavian countries (1 scanner per 95 000) might partially explain such an observation.These findings suggest that other factors beyond a patient''s medical condition might influence inappropriate or overuse of these services. This issue has numerous potentially undesirable consequences both for patients and for healthcare systems: subsequent costly evaluations and emotional stress owing to false-positive results, exposure to unnecessary radiation and increasing the cost of healthcare reflect only the tip of this iceberg [6].Clinical decision rules [6], appropriateness criteria [7, 8] and imaging guidelines [9, 10] are decision tools designed to minimise unnecessary utilisation of imaging techniques. These tools enable physicians to categorise patients as high or low risk for a certain disease. On the basis of these guidelines, imaging studies are requested only for at-risk patients who have a high chance of having abnormal findings in imaging evaluations. These decision tools also aim to alleviate the financial burden of unnecessary evaluations on healthcare systems and to reduce preventable radiation exposure to patients. It is essential that these tools effectively differentiate affected from non-affected individuals; ideally they should neither miss a covert disease (false-negative) nor inappropriately label an unaffected individual as diseased (false-positive).One frequently evaluated imaging technique in radiology health services research is CT of the head for mild head trauma [11-13]. Although there is consensus that severe head trauma should be evaluated by head CT scan if clinically warranted, there is debate about requesting head CT scan for mild-to-moderate head trauma, which typically have a low chance of intracranial lesions. As a result, researchers have attempted to develop different imaging guidelines to differentiate between mild-to-moderate head trauma with and without intracranial lesions. For example, the National Institute of Health and Clinical Excellence (NICE) published “Head injury triage, assessment, investigation and early management of head injury in infants, children and adults, clinical guideline” that aims to improve patient care and minimise unnecessary use of head CT by triaging head trauma patients into low- or high-risk groups [11]. Only high-risk patients thought to have a greater chance of intracranial lesions are referred for evaluation by head CT scan [11]. In order to triage a patient to high-risk or low-risk, the guideline uses nine demographic and injury-related characteristics. The presence of any one of these characteristics puts the patient in the high-risk category, indicating that a CT scan should be requested. These characteristics are: Glasgow Coma Scale (GCS) <13 at the time of admission or <15 during the first 2 h after injury; retrograde amnesia more than 30 min; suspected open, depressed or basal fracture of skull; recurrent vomiting; age ≥65 years; any focal neural deficit; any coagulopathy; any seizure; and experiencing a “dangerous” injury mechanism [11]. An injury is considered dangerous if the patient is ejected from a motor vehicle, is a pedestrian struck by a motor vehicle or has fallen from ≥3 feet or ≥5 steps provided some loss of consciousness or amnesia has been experienced [11].Many “guideline-development studies”, including those evaluating the NICE guideline, have presented the sensitivity (SN) and specificity (SP) of a new decision tool to describe the potential improvements in use of imaging techniques as a result of adopting the new guideline. However, SN and SP are measures designed to assess how well a new guideline compares with a gold standard (e.g. the NICE guideline vs head CT scan as a gold standard for diagnosis of intracranial lesions). By definition, a gold standard is a test that is considered the definitive approach for diagnosing a disease. Ideally, this test should neither miss any sick person nor falsely label a healthy person as a sick individual [14, 15].Unfortunately, SP and SN do not evaluate how many patients with a positive test actually have the disease, nor do they evaluate how many patients with a negative test do not have the disease. To evaluate these characteristics of a decision tool other measures, namely the positive predictive value (PPV) and negative predictive value (NPV), should be calculated.This report highlights some of the main methodological challenges in the interpretation of studies that attempt to evaluate the development of an imaging guideline and the effectiveness of an imaging guideline in real-world practice. We define four key measures of a decision tool: SN, SP, PPV and NPV. Using data from two hypothetical populations, we explain how these measures can be calculated and interpreted. We place special emphasis on the purpose of and differences between the SN and SP values and the PPV and NPV. Borrowing information from studies conducted by Stein et al [13] and Smits et al [12], we demonstrate how these measures should be used in the radiology healthcare services research to evaluate decision guidelines.     

Comparison of IOPen rebound tonometer with Goldmann applanation tonometer at different IOP levels

AIM:To compare the accuracy of IOPen rebound tonometer with Goldmann applanation tonometer (GAT) in individuals with low, normal and high intraocular pressure (IOP) and to evaluate the effect of central corneal thickness (CCT) on IOP measurements.METHODS:This cross-sectional study consisted of 159 participants. IOP of one eye of each subject was measured consecutively with IOPen and GAT. Then CCT was measured using an ultrasonic pachymeter. Based on GAT IOP readings, participants were divided into low, normal and high IOP groups. Correlation between tonometers and CCT was calculated by spearman’s correlation coefficient. Agreement between tonometers was evaluated using Bland-Altman method.RESULTS: Non-significant underestimation of IOP by IOPen was observed in low IOP group (Mean difference:0.20mmHg; P=0.454) and also in normal IOP group (Mean difference:0.56mmHg; P=0.065). However, IOPen significantly overestimated IOP in high IOP group (Mean difference:1.06mmHg; P=0.038). The 95% limits of agreement (LoA) width between IOPen and GAT IOPs were 7.84, 8.57 and 14.27mmHg in low, normal and high IOP groups, respectively. Low IOP group had thinner corneas compared to high IOP group (P=0.034). IOP measurements taken by IOPen were not influenced by CCT (P=0.099) while poor correlation between CCT and GAT was found (R=0.17, P=0.032). Using receiver operating characteristic (ROC) curve, cutoff value of 18.75mmHg was determined for IOPen with sensitivity of 98.1 and specificity of 97.2%.CONCLUSION:Accuracy of IOPen is comparable to GAT in patients with low or normal IOP but IOPen overestimates IOP at high IOP levels. CCT does not affect IOP readings with IOPen.     

Identification of “substrate fibrillators” and “trigger fibrillators” by pacemaker diagnostics

BACKGROUND: The population of patients likely to respond to selected pacing algorithms for maintenance of sinus rhythm is unknown. OBJECTIVES: The purpose of this study was to identify patients with specific onset patterns of paroxysmal atrial fibrillation (AF). METHODS: Dual-chamber pacemakers with advanced diagnostic functions were implanted in 112 patients with conventional indications for antibradycardia pacing and a history of paroxysmal AF. Pacemaker diagnostic data were analyzed after 97.5 +/- 40.9 days. According to the frequency of premature atrial contractions (PACs) during the 5 minutes before AF onset, patients were assigned to one of three groups: group A (high PAC activity), group B (moderate PAC activity), or group C (low PAC activity). RESULTS: AF burden was lower in group A (4.6% +/- 2.4%) than group B (15.8% +/- 3.0%, P = .003) and group C (15.5% +/- 3.1%, P = .003). Fewer AF episodes occurred in group A (2.1 +/- 1.3 per day) than group B (3.8 +/- 1.2 per day, P = .006). Mean AF episode duration was shorter in group A (11.4 +/- 10.2 hours) than group C (41.4 +/- 27.5 hours, P = .03). CONCLUSION: The coincidence of low PAC activity before AF onset, high AF burden, and extended arrhythmia episode duration appears to be the consequence of a high atrial substrate factor. In these "substrate fibrillators," the efficacy of pacing algorithms for maintenance of sinus rhythm may be limited. In contrast, "trigger fibrillators" exhibiting low AF burden despite high PAC incidence may represent the target population for specific PAC-suppressing pacing algorithms.