Optimization of deterministic transport parameters for the calculation of the dose distribution around a high dose-rate 192Ir brachytherapy source

The goal of this work was to calculate the dose distribution around a high dose-rate 192Ir brachytherapy source using a multi-group discrete ordinates code and then to compare the results with a Monte Carlo calculated dose distribution. The unstructured tetrahedral mesh discrete ordinates code Attila version 6.1.1 was used to calculate the photon kerma rate distribution in water around the Nucletron microSelectron mHDRv2 source. MCNPX 2.5.c was used to compute the Monte Carlo water photon kerma rate distribution. Two hundred million histories were simulated, resulting in standard errors of the mean of less than 3% overall. The number of energy groups, S(n) (angular order), P(n) (scattering order), and mesh elements were varied in addition to the method of analytic ray tracing to assess their effects on the deterministic solution. Water photon kerma rate matrices were exported from both codes into an in-house data analysis software. This software quantified the percent dose difference distribution, the number of points within +/- 3% and +/- 5%, and the mean percent difference between the two codes. The data demonstrated that a 5 energy-group cross-section set calculated results to within 0.5% of a 15 group cross-section set. S12 was sufficient to resolve the solution in angle. P2 expansion of the scattering cross-section was necessary to compute accurate distributions. A computational mesh with 55 064 tetrahedral elements in a 30 cm diameter phantom resolved the solution spatially. An efficiency factor of 110 with the above parameters was realized in comparison to MC methods. The Attila code provided an accurate and efficient solution of the Boltzmann transport equation for the mHDRv2 source.     

Contraception: attitudes and experiences of Saudi Arabian women

We carried out a survey to find the contraception practices and experiences of Saudi Arabian females. A preset questionnaire was developed, and married Saudi females were asked to answer the questionnaire. Between July and December 2008, 215 women completed the questionnaire. The average age was 37.6 ± 9.1 years. One hundred and sixty one of the women said they were using contraception. Fifty-nine (36.6%) said they were using oral contraception pills (OCP) and 32 (19.9%) said they were using intra-uterine contraceptive devices (IUCDs). One hundred and twenty-seven (78.8%) of the women were satisfied with the contraception they were using. We found that a majority of Saudi women are using contraception methods but without medical advice.     

Pediatric intracranial hypertension: Experience from 2 Tertiary Centers

Objectives:To review the experience of 2 tertiary centers in Saudi Arabia with intracranial hypertension (IH) in the pediatric population.Methods:We retrospectively reviewed and analyzed pediatric patients diagnosed with IH from June 2002 to May 2017 in 2 institutes.Results:We identified 53 patients (30 females and 23 males) with a mean age of 7 years at the time of presentation. Among them, 41 patients were younger than 12 years, and 12 were older. Obese and overweight patients constituted 27.00% (n = 14) of all cases, 8 (66.7%) of whom were older than 12 years. The most common presenting feature was papilledema followed by headache. Vitamin D deficiency, which constituted the most common associated condition, was identified in 12 (22.6%) patients. Acetazolamide was the treatment option in 98.11% of patients, and only 5.7% underwent surgical interventions. The length of follow-up ranged from 6 months to 8 years.Conclusion:Intracranial hypertension is rare in children and commonly seen in overweight females older than 12 years similar to adults. Patients younger than 12 years tend to develop secondary IH. More studies are needed to characterize the clinical presentation and guide the management plan.

Intracranial hypertension (IH) is rarely reported in children. It is characterized by increased intracranial pressure (ICP) without any evidence of underlying brain pathology, structural abnormalities, hydrocephalus, or any abnormal meningeal enhancement.1 The incidence of IH differs from region to region due to variations in the prevalence of obesity and other secondary causes. The annual incidence of IH in children is 0.9 per 100,000 in the United States,2 0.5 per 100,000 in Germany,3 0.6 per 100,000 in Nova Scotia and Prince Edward Island in Eastern Canada,4 and 1.2 per 100,000 in Croatia.5 A study carried out in Oman estimated the incidence of IH to be 1.9 per 100,000 in children below 15 years of age; with it being higher in female children.6 The present study aimed to review the clinical presentation, possible aetiological factors, diagnosis, management, and outcomes in children with IH in 2 tertiary institutes in Saudi Arabia.     

Influence of androgens on bone mass in young women with sickle cell anemia

OBJECTIVE: To evaluate the relationship between the gender hormonal levels and bone mineral density in premenopausal women suffering with sickle cell disease. METHODS: A cross-sectional study including consecutive female adult patients with sickle cell anemia attending the outpatient hematology/orthopaedic clinics, or admitted to King Fahd University Hospital, Al-Khobar, Saudi Arabia, between August 2006 and June 2007. Patient's age was documented, and body mass index was calculated. Blood was drawn for complete blood picture, biochemistry, and hormonal profile including total estradiol E2 and total testosterone Te. Bone mineral density BMD was measured for all patients using dual energy x-ray absorptiometry scan at the hip and lumbar spine. RESULTS: We analyzed the data of 51 patients with an average age of 26+/-3.1 years. Patients were divided into 2 groups group A and group B. Group A had normal BMD and group B with low BMD. Thirty-one (60.8%) were in group A and 20 (39.2%) were in group B. The E2 level was not statistically different between the 2 groups, while Te level was significantly lower in women with low BMD 38+/-11.8 versus 22.3+/-11.7 ng/dl, p<0.001. CONCLUSION: Our study indicates that in premenopausal female patients with sickle cell anemia, testosterone may play a role in the preservation of bone mass.     

Four and a half LIM protein 1: a partner for KCNA5 in human atrium

AIMS: Protein-protein interactions are critical for the normal membrane trafficking, localization, and function of voltage-gated ion channels. In human heart, the Shaker-related voltage-gated K(+) channel KCNA5 alpha-subunit forms the major basis of an atrial-specific, ultra-rapid delayed rectifier K(+) current, I(Kur). We sought to identify proteins that interact with KCNA5 in human atrium and investigate their role in the I(Kur) complex. METHODS AND RESULTS: Using a glutathione-S-transferase (GST)-KCNA5 C-terminal fusion protein and mass spectrometry-based methods, the scaffolding protein four and a half LIM (for Lin-11, Isl-1, and Mec3) protein 1 (FHL1) was identified as a potential protein partner for KCNA5. Immunoprecipitation experiments confirmed a physical interaction of FHL1 with the K(+) channel complex in human atrium, as well as in Chinese hamster ovary (CHO) cells transfected with both KCNA5 and FHL1. In cotransfected cells, confocal microscopy demonstrated areas of colocalization after immunolabelling both proteins. To investigate the functional effects of this interaction, K(+) currents were recorded in CHO cells transfected with KCNA5 in the absence and presence of FHL1 coexpression. With coexpression of FHL1, K(+) current density was markedly increased, compared with cells expressing KCNA5 alone. This effect was associated with a shift in the voltage dependence of K(+) channel activation to more positive potentials, consistent with findings of I(Kur) in atrial myocytes. FHL1 also increased the extent and speed of K(+) current slow inactivation, with additional effects on the voltage dependence and recovery of this process. CONCLUSION: These results support a role of FHL1 as a key molecular component in the I(Kur) complex in human atrium, where it likely regulates functional expression of KCNA5.     

Dilated cardiomyopathy and myocardial infarction secondary to congenital generalized lipodystrophy

Congenital generalized lipodystrophy, also known as Berardinelli-Seip syndrome, is a very rare hereditary syndrome that is characterized by an almost complete absence of adipose tissue from birth. Cardiac involvement seems to have substantial influence in the long-term prognosis. Herein, we report an apparently unique case of congenital generalized lipodystrophy with cardiac sequelae. A 17-year-old woman, diagnosed in childhood with Berardinelli-Seip syndrome, presented with severe epigastric pain that was secondary to previous myocardial infarction. The patient had ischemia, dilated cardiomyopathy, and congestive heart failure, but no coronary artery disease. She was discharged from the hospital in stable condition after 3 days of medical treatment. To our knowledge, this is the 1st reported case of congenital generalized lipodystrophy with dilated cardiomyopathy, congestive heart failure, severe mitral regurgitation, and inferior myocardial infarction as cardiac sequelae of this syndrome--but without evidence of coronary artery disease or cardiac hypertrophy. In addition to discussing this patient's case, we present diagnostic and therapeutic approaches to Berardinelli-Seip syndrome.     

Concomitant and noncanonical JAK2 and MPL mutations in JAK2V617F‐ and MPLW515 L‐positive myelofibrosis

Sequential genotyping for phenotype‐driver mutations in JAK2 (exon 14), CALR (exon 9), and MPL (exon 10) is recommended in patients with myeloproliferative neoplasms. Yet, atypical JAK2‐ and MPL‐mutations were described in some triple‐negative patients. Whether noncanonical and/or concomitant JAK2‐ and MPL‐mutations exist in myelofibrosis (MF) regardless of phenotype‐driver mutations is not yet elucidated. For this, next‐generation sequencing (NGS) was performed using blood genomic DNA from 128 MF patients (primary MF, n = 93; post‐ET–MF, n = 18; post‐PV–MF, n = 17). While no atypical JAK2‐ or MPL‐mutations were seen in 24 CALR‐positive samples, two JAK2‐mutations [c.3323A > G, p.N1108S; c.3188G > A, p.R1063H] were detected in two of the 21 (9.5%) triple‐negative patients. Twelve of the 82 (14.6%) JAK2V617F‐positive cases had coexisting germline JAK2‐mutations [JAK2R1063H, n = 6; JAK2R893T, n = 1; JAK2T525A, n = 1] or at least one somatic MPL‐mutation [MPLY591D, n = 3; MPLW515 L, n = 2; MPLE335K, n = 1]. Overall, MPL‐mutations always coexisted with JAK2V617F and/or other MPL‐mutations. None of the JAK2V617F plus a second JAK2‐mutation carried a TET2‐mutation but all patients with JAK2V617F plus an MPL‐mutation harbored a somatic TET2‐mutation. Four genomic clusters could be identified in the JAK2V617F‐positive cohort. Cluster‐I (10%) (noncanonical JAK2_{mutated (mut)} + TET2_{wildtype (wt)}) were younger and had less proliferative disease compared with cluster‐IV (5%) (TET2_mut + MPL_mut). In conclusion, recurrent concomitant classical and/or noncanonical JAK2‐ and MPL‐mutations could be detected by NGS in 15.7% of JAK2V617F‐ and MPLW515‐positive MF patients with genotype‐phenotype associations. Many of the germline and/or somatic mutations might act as “Significantly Mutated Genes” contributing to the pathogenesis and phenotypic heterogeneity. A cost‐effective NGS‐based approach might be an important step towards patient‐tailored medicine.