Considerations on the Castrop formula for calculation of intraocular lens power

Background: To explain the concept of the Castrop lens power calculation formula and show the application and results from a large dataset compared to classical formulae. Methods: The Castrop vergence formula is based on a pseudophakic model eye with 4 refractive surfaces. This was compared against the SRKT, Hoffer-Q, Holladay1, simplified Haigis with 1 optimized constant and Haigis formula with 3 optimized constants. A large dataset of preoperative biometric values, lens power data and postoperative refraction data was split into training and test sets. The training data were used for formula constant optimization, and the test data for cross-validation. Constant optimization was performed for all formulae using nonlinear optimization, minimising root mean squared prediction error. Results: The constants for all formulae were derived with the Levenberg-Marquardt algorithm. Applying these constants to the test data, the Castrop formula showed a slightly better performance compared to the classical formulae in terms of prediction error and absolute prediction error. Using the Castrop formula, the standard deviation of the prediction error was lowest at 0.45 dpt, and 95% of all eyes in the test data were within the limit of 0.9 dpt of prediction error. Conclusion: The calculation concept of the Castrop formula and one potential option for optimization of the 3 Castrop formula constants (C, H, and R) are presented. In a large dataset of 1452 data points the performance of the Castrop formula was slightly superior to the respective results of the classical formulae such as SRKT, Hoffer-Q, Holladay1 or Haigis

Managing the complexity of doing it all : an exploratory study on students' experiences when trained stepwise in conducting consultations

Background: At most medical schools the components required to conduct a consultation, medical knowledge, communication, clinical reasoning and physical examination skills, are trained separately. Afterwards, all the knowledge and skills students acquired must be integrated into complete consultations, an art that lies at the heart of the medical profession. Inevitably, students experience conducting consultations as complex and challenging. Literature emphasizes the importance of three didactic course principles: moving from partial tasks to whole task learning, diminishing supervisors' support and gradually increasing students' responsibility. This study explores students' experiences of an integrated consultation course using these three didactic principles to support them in this difficult task. Methods: Six focus groups were conducted with 20 pre-clerkship and 19 clerkship students in total. Discussions were audiotaped, transcribed and analysed by Nvivo using the constant comparative strategy within a thematic analysis. Results: Conducting complete consultations motivated students in their learning process as future physician. Initially, students were very much focused on medical problem solving. Completing the whole task of a consultation obligated them to transfer their theoretical medical knowledge into applicable clinical knowledge on the spot. Furthermore, diminishing the support of a supervisor triggered students to reflect on their own actions but contrasted with their increased appreciation of critical feedback. Increasing students' responsibility stimulated their active learning but made some students feel overloaded. These students were anxious to miss patient information or not being able to take the right decisions or to answer patients' questions, which sometimes resulted in evasive coping techniques, such as talking faster to prevent the patient asking questions. Conclusion: The complex task of conducting complete consultations should be implemented early within medical curricula because students need time to organize their medical knowledge into applicable clinical knowledge. An integrated consultation course should comprise a step-by-step teaching strategy with a variety of supervisors' feedback modi, adapted to students' competence. Finally, students should be guided in formulating achievable standards to prevent them from feeling overloaded in practicing complete consultations with simulated or real patients

Religiousness and preoperative anxiety: a correlational study

<p>Abstract</p> <p>Background</p> <p>Major life changes are among factors that cause anxiety, and one of these changes is surgery. Emotional reactions to surgery have specific effects on the intensity and velocity as well as the process of physical disease. In addition, they can cause delay in patients recovery. This study is aimed at determining the relationship between religious beliefs and preoperative anxiety.</p> <p>Methods</p> <p>This survey is a correlational study to assess the relationship between religious beliefs and preoperative anxiety of patients undergoing abdominal, orthopaedic, and gynaecologic surgery in educational hospitals. We used the convenience sampling method. The data collection instruments included a questionnaire containing the Spielberger State-Trait Anxiety Inventory (STAI), and another questionnaire formulated by the researcher with queries on religious beliefs and demographic characteristics as well as disease-related information. Analysis of the data was carried out with SPSS software using descriptive and inferential statistics. Results were arranged in three tables.</p> <p>Results</p> <p>The findings showed that almost all the subjects had high level of religiosity and moderate level of anxiety. In addition, there was an inverse relationship between religiosity and intensity of anxiety, though this was not statistically significant.</p> <p>Conclusion</p> <p>The results of this study can be used as evidence for presenting religious counselling and spiritual interventions for individuals undergoing stress. Finally, based on the results of this study, the researcher suggested some recommendations for applying results and conducting further research.</p

Ready or not? Expectations of faculty and medical students for clinical skills preparation for clerkships

Background: Preclerkship clinical-skills training has received increasing attention as a foundational preparation for clerkships. Expectations among medical students and faculty regarding the clinical skills and level of skill mastery needed for starting clerkships are unknown. Medical students, faculty teaching in the preclinical setting, and clinical clerkship faculty may have differing expectations of students entering clerkships. If students&#x0027; expectations differ from faculty expectations, students may experience anxiety. Alternately, congruent expectations among students and faculty may facilitate integrated and seamless student transitions to clerkships. Aims: To assess the congruence of expectations among preclerkship faculty, clerkship faculty, and medical students for the clinical skills and appropriate level of clinical-skills preparation needed to begin clerkships. Methods: Investigators surveyed preclinical faculty, clerkship faculty, and medical students early in their basic clerkships at a North American medical school that focuses on preclerkship clinical-skills development. Survey questions assessed expectations for the appropriate level of preparation in basic and advanced clinical skills for students entering clerkships. Results: Preclinical faculty and students had higher expectations than clerkship faculty for degree of preparation in most basic skills. Students had higher expectations than both faculty groups for advanced skills preparation. Conclusions: Preclinical faculty, clerkship faculty, and medical students appear to have different expectations of clinical-skills training needed for clerkships. As American medical schools increasingly introduce clinical-skills training prior to clerkships, more attention to alignment, communication, and integration between preclinical and clerkship faculty will be important to establish common curricular agendas and increase integration of student learning. Clarification of skills expectations may also alleviate student anxiety about clerkships and enhance their learning

Low oxygen tension primes aortic endothelial cells to the reparative effect of tissue-protective cytokines

Erythropoietin (EPO) has both erythropoietic and tissue-protective properties. The EPO analogues carbamylated EPO (CEPO) and pyroglutamate helix B surface peptide (pHBSP) lack the erythropoietic activity of EPO but retain the tissue-protective properties that are mediated by a heterocomplex of EPO receptor (EPOR) and the β common receptor (βCR). We studied the action of EPO and its analogues in a model of wound healing where a bovine aortic endothelial cells (BAECs) monolayer was scratched and the scratch closure was assessed over 24 h under different oxygen concentrations. We related the effects of EPO and its analogues on repair to their effect on BAECs proliferation and migration (evaluated using a micro-Boyden chamber). EPO, CEPO and pHBSP enhanced scratch closure only at lower oxygen (5%), while their effect at atmospheric oxygen (21%) was not significant. The mRNA expression of EPOR was doubled in 5% compared to 21% oxygen, and this was associated with increased EPOR assessed by immunofluorescence and Western blot. By contrast βCR mRNA levels were similar in 5% and 21% oxygen. EPO and its analogues increased both BAECs proliferation and migration, suggesting that both may be involved in the reparative process. The priming effect of low oxygen tension on the action of tissue-protective cytokines may be of relevance to vascular disease, including atherogenesis and restenosis

Weather sensitivity in migraineurs

The scientific evidence for weather being a trigger factor for migraine attacks is inconclusive. We investigated the association between weather components and the onset and severity of attacks. Headache diaries of 20 migraineurs were analyzed retrospectively and correlated in 4-h intervals to atmospheric air pressure, temperature, and relative air humidity in Berlin (Germany) for a period of 12 consecutive months. Absolute values and relative changes within the preceding 24 h were analyzed. Migraine attacks started most frequently at 4 a.m. and reached the highest intensity between 4 and 8 a.m. A highly significant association between meteorological variables and the occurrence of migraine attacks was found in six patients. The onset of an attack as well as high headache intensity was associated with lower temperature and higher humidity. Our data indicate that a subgroup of migraineurs is highly sensitive to changes of certain weather components

Measurement of triple gauge boson couplings from W⁺W⁻ production at LEP energies up to 189 GeV

A measurement of triple gauge boson couplings is presented, based on W-pair data recorded by the OPAL detector at LEP during 1998 at a centre-of-mass energy of 189 GeV with an integrated luminosity of 183 pb⁻¹. After combining with our previous measurements at centre-of-mass energies of 161–183 GeV we obtain κ = 0.97_{-0.16}^{+0.20}, g_{1}^{z} = 0.991_{-0.057}^{+0.060} and λ = -0.110_{-0.055}^{+0.058}, where the errors include both statistical and systematic uncertainties and each coupling is determined by setting the other two couplings to their Standard Model values. These results are consistent with the Standard Model expectations

A case–control study of risk of leukaemia in relation to mobile phone use

Background Mobile phone use is now ubiquitous, and scientific reviews have recommended research into its relation to leukaemia risk, but no large studies have been conducted.Methods In a case-control study in South East England to investigate the relation of acute and non-lymphocytic leukaemia risk to mobile phone use, 806 cases with leukaemia incident 2003-2009 at ages 18-59 years (50% of those identified as eligible) and 585 non-blood relatives as controls (provided by 392 cases) were interviewed about mobile phone use and other potentially aetiological variables.Results No association was found between regular mobile phone use and risk of leukaemia (odds ratio (OR)=1.06, 95% confidence interval (CI)=0.76, 1.46). Analyses of risk in relation to years since first use, lifetime years of use, cumulative number of calls and cumulative hours of use produced no significantly raised risks, and there was no evidence of any trends. A non-significantly raised risk was found in people who first used a phone 15 or more years ago (OR=1.87, 95% CI=0.96, 3.63). Separate analyses of analogue and digital phone use and leukaemia subtype produced similar results to those overall.Conclusion This study suggests that use of mobile phones does not increase leukaemia risk, although the possibility of an effect after long-term use, while biologically unlikely, remains open

C3 Glomerulopathy and Related Disorders in Children: Etiology-Phenotype Correlation and Outcomes

BACKGROUND AND OBJECTIVES: Membranoproliferative GN and C3 glomerulopathy are rare and overlapping disorders associated with dysregulation of the alternative complement pathway. Specific etiologic data for pediatric membranoproliferative GN/C3 glomerulopathy are lacking, and outcome data are based on retrospective studies without etiologic data. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A total of 80 prevalent pediatric patients with membranoproliferative GN/C3 glomerulopathy underwent detailed phenotyping and long-term follow-up within the National Registry of Rare Kidney Diseases (RaDaR). Risk factors for kidney survival were determined using a Cox proportional hazards model. Kidney and transplant graft survival was determined using the Kaplan-Meier method. RESULTS: Central histology review determined 39 patients with C3 glomerulopathy, 31 with immune-complex membranoproliferative GN, and ten with immune-complex GN. Patients were aged 2-15 (median, 9; interquartile range, 7-11) years. Median complement C3 and C4 levels were 0.31 g/L and 0.14 g/L, respectively; acquired (anticomplement autoantibodies) or genetic alternative pathway abnormalities were detected in 46% and 9% of patients, respectively, across all groups, including those with immune-complex GN. Median follow-up was 5.18 (interquartile range, 2.13-8.08) years. Eleven patients (14%) progressed to kidney failure, with nine transplants performed in eight patients, two of which failed due to recurrent disease. Presence of >50% crescents on the initial biopsy specimen was the sole variable associated with kidney failure in multivariable analysis (hazard ratio, 6.2; 95% confidence interval, 1.05 to 36.6; P50% crescents on the initial biopsy specimen. CONCLUSIONS: Crescentic disease was a key risk factor associated with kidney failure in a national cohort of pediatric patients with membranoproliferative GN/C3 glomerulopathy and immune-complex GN. Presenting eGFR and crescentic disease help define prognostic groups in pediatric C3 glomerulopathy. Acquired abnormalities of the alternative pathway were commonly identified but not a risk factor for kidney failure

Auditory stimulation of opera music induced prolongation of murine cardiac allograft survival and maintained generation of regulatory CD4+CD25+ cells

<p>Abstract</p> <p>Background</p> <p>Interactions between the immune response and brain functions such as olfactory, auditory, and visual sensations are likely. This study investigated the effect of sounds on alloimmune responses in a murine model of cardiac allograft transplantation.</p> <p>Methods</p> <p>Naïve CBA mice (H2^k) underwent transplantation of a C57BL/6 (B6, H2^b) heart and were exposed to one of three types of music--opera (<it>La Traviata</it>), classical (Mozart), and New Age (Enya)--or one of six different single sound frequencies, for 7 days. Additionally, we prepared two groups of CBA recipients with tympanic membrane perforation exposed to opera for 7 days and CBA recipients exposed to opera for 7 days before transplantation (pre-treatment). An adoptive transfer study was performed to determine whether regulatory cells were generated in allograft recipients. Immunohistochemical, cell-proliferation, cytokine, and flow cytometry assessments were also performed.</p> <p>Results</p> <p>CBA recipients of a B6 cardiac graft that were exposed to opera music and Mozart had significantly prolonged allograft survival (median survival times [MSTs], 26.5 and 20 days, respectively), whereas those exposed to a single sound frequency (100, 500, 1000, 5000, 10,000, or 20,000 Hz) or Enya did not (MSTs, 7.5, 8, 9, 8, 7.5, 8.5 and 11 days, respectively). Untreated, CBA mice with tympanic membrane perforations and CBA recipients exposed to opera for 7 days before transplantation (pre-treatment) rejected B6 cardiac grafts acutely (MSTs, 7, 8 and 8 days, respectively). Adoptive transfer of whole splenocytes, CD4⁺cells, or CD4⁺CD25⁺cells from opera-exposed primary allograft recipients resulted in significantly prolonged allograft survival in naive secondary recipients (MSTs, 36, 68, and > 100 days, respectively). Proliferation of splenocytes, interleukin (IL)-2 and interferon (IFN)-γ production was suppressed in opera-exposed mice, and production of IL-4 and IL-10 from opera-exposed transplant recipients increased compared to that from splenocytes of untreated recipients. Flow cytometry studies showed an increased CD4⁺CD25⁺Forkhead box P3 (Foxp3)⁺cell population in splenocytes from those mice.</p> <p>Conclusion</p> <p>Our findings indicate that exposure to opera music, such as La traviata, could affect such aspects of the peripheral immune response as generation of regulatory CD4⁺CD25⁺cells and up-regulation of anti-inflammatory cytokines, resulting in prolonged allograft survival.</p