Geological and engineering appraisal of hydraulic frac sand in some Egyptian localities as a proppant of oil well drilling.

Sand that comprises high purity silica grains, in large percent, is of the best naturally occurring grains that can be used as proppants during hydraulic fracturing processes. Proppants are used to increase formations' permeability; to increase reservoirs' productivity, or to reopen plays and utilize unconventional reservoirs. The potentiality of these grains to be used as frac proppants is determined according to certain physical, mechanical, petrographical and chemical evaluations that include particle size analysis, acid solubility, turbidity, bulk density, crush resistance and hardness, sphericity and roundness, mineral and chemical composition. This study shows the evaluation of the silica sand samples collected from Malha Formation in Wadi El Dakhal, Eastern Desert; Naqus Formation in Wadi Qena, Eastern Desert; and Bahariya Formation at Gabal El-Dist area in Bahariya Oasis, Western Desert, Egypt. The samples were examined according to frac sand international standards. The results showed the potentiality of the tested samples to be utilized as frac sand proppants. Wadi El-Dakhal and Wadi Qena studied areas possess very promising samples for frac sand production. But, the quality of Wadi El-Dakhal samples is somewhat better than that of Wadi Qena samples. The samples of Gabal El-Dist in Bahariya Oasis are relatively less to achieve the requirements; however, they can be utilized in shallow depths. The assessment testing of the studied samples revealed a good results and verifying the standard requirements, where SiO2 content is 89.1% in Wadi Qena, 99.3 % in Wadi Dakhal and 78.1% in Gebel El Dist, crush resistance at 5000 psi gives fine percent 4.71 W.Q, 6.78 W.D, and 14.11 B.O, turbidity readings raining from 100.5 to 133.25 NTU, the grain roundness are rounded to sub rounded, and grain size distribution range is 30/50 to 40/70 grading (710 um to 210 um).

Sensitivity and specificity of the classification of psoriatic arthritis criteria in early psoriatic arthritis.

OBJECTIVE: To assess the sensitivity and specificity of the Classification of Psoriatic Arthritis (CASPAR) Study Group criteria in early psoriatic arthritis (PsA) and to compare them with the sensitivity and specificity of the Moll and Wright criteria. METHODS: The CASPAR Study Group criteria were applied to patients with early PsA (<24 months symptom duration) and to control patients with other new-onset inflammatory arthritides. Both groups were naive to all disease-modifying antirheumatic drugs. The gold standard diagnosis was confirmed by the consulting rheumatologist using radiography and magnetic resonance imaging where required. Proportions of patients and control patients meeting the criteria were compared using McNemar's tests. RESULTS: We recruited a total of 111 patients with early PsA and 111 control patients with other forms of inflammatory arthritis (82 with rheumatoid arthritis, 13 with undifferentiated arthritis, 9 with spondylarthritis, 4 with inflammatory osteoarthritis, and 3 with crystal arthritis) to the study. The sensitivity of the CASPAR Study Group criteria in classifying early PsA was 87.4% compared to 80.2% for the Moll and Wright criteria. The specificity for both criteria was 99.1%. When considering different cut points for the CASPAR Study Group criteria, the best cut point for classification remained a score of ≥ 3 as in the original CASPAR Study Group analysis. Considering a score of ≥ 2 gave a higher sensitivity of 99.1% but resulted in a drop in specificity to 94.6%. Regression analysis determined that psoriasis and rheumatoid factor negativity were the most important features that differentiated PsA, followed by nail psoriasis and current or previous dactylitis. CONCLUSION: The CASPAR Study Group criteria are more sensitive than the Moll and Wright criteria in classifying early PsA. Although their sensitivity for early PsA is lower than that for established disease, the CASPAR Study Group criteria are valid for use as inclusion criteria for trials in early PsA.

The composite DAS Score is impractical to use in daily practice: evidence that physicians use the objective component of the DAS in decision making.

INTRODUCTION AND BACKGROUND: The disease activity score for 28 joints (DAS28) is widely used for assessing disease activity in rheumatoid arthritis and its use is recommended for establishing the need for anti- tumor necrosis factor drugs, according to British Society for Rheumatology guidelines. However, calculation of the score requires a laboratory measurement of inflammation (either erythrocyte sedimentation rate or C-reactive protein) so that it is not possible to have the actual score when the patient seen in the clinic and, therefore, it is not possible to make immediate treatment decisions based on the DAS28 score. METHODS: This is an audit of clinic-based treatment decisions, collecting data for the DAS28 on consecutive patients with rheumatoid arthritis. The nonlaboratory elements of the DAS score were completed along with a physician global assessment and any treatment decisions were recorded. RESULTS: Data on 100 patients were collected. Even when the patients were judged to have active disease by DAS28 treatment switches or increases were not always made. In logistic regression analyses, using treatment increase or switch as the dependent variable, only the swollen joint count was significant. CONCLUSION: There is evidence from this study that the DAS score is limited in daily clinical practice. In this audit of practice treatment, changes seem to be made on objective physician assessments rather than patient recorded assessments.

Mutations in 15-hydroxyprostaglandin dehydrogenase cause primary hypertrophic osteoarthropathy.

Digital clubbing, recognized by Hippocrates in the fifth century BC, is the outward hallmark of pulmonary hypertrophic osteoarthropathy, a clinical constellation that develops secondary to various acquired diseases, especially intrathoracic neoplasm. The pathogenesis of clubbing and hypertrophic osteoarthropathy has hitherto been poorly understood, but a clinically indistinguishable primary (idiopathic) form of hypertrophic osteoarthropathy (PHO) is recognized. This familial disorder can cause diagnostic confusion, as well as significant disability. By autozygosity methods, we mapped PHO to chromosome 4q33-q34 and identified mutations in HPGD, encoding 15-hydroxyprostaglandin dehydrogenase, the main enzyme of prostaglandin degradation. Homozygous individuals develop PHO secondary to chronically elevated prostaglandin E(2) levels. Heterozygous relatives also show milder biochemical and clinical manifestations. These findings not only suggest therapies for PHO, but also imply that clubbing secondary to other pathologies may be prostaglandin mediated. Testing for HPGD mutations and biochemical testing for HPGD deficiency in patients with unexplained clubbing might help to obviate extensive searches for occult pathology.

Development of an assessment tool for dactylitis in patients with psoriatic arthritis.

OBJECTIVE: Psoriatic arthritis (PsA) is characterized by inflammatory arthritis in the presence of psoriasis. Certain clinical features help characterize this disorder, one of which is dactylitis. Hitherto an instrument for quantifying dactylitis has not been developed. METHODS: A dactylitis score sheet was developed. The score is a function of finger circumference and tenderness, assessed and summed across all dactylitic digits. Initial results were obtained on a small sample of patients attending clinics. Inter and intraobserver agreement on the presence of dactylitis using kappa agreement statistics, and the validity and reliability of the instrument, using intraclass correlation coefficients (ICC), were assessed in a further group of 7 patients with PsA. RESULTS: Tender dactylitis was deemed present in 74 digits out of a total of 280 (140 digits on each occasion). Kappa agreement scores for the presence of tender dactylitis were poor to good, both within and between observers (0.25 to 0.89 between observers and 0.29 to 0.91 within observers). Agreement scores for non-tender dactylitis were poor (0.01 to 0.66 between observers and 0.01 to 0.59 within-observer agreement). The new dactylitis instrument was simple and easy to administer and was found to measure appropriate scores in patients with different severity of dactylitis. Inter and intraobserver agreement was good (interobserver ICC 0.90, 95% CI 0.74-0.98; intraobserver ICC 0.84, 95% CI 0.71-0.92). Intraobserver ICC improved but interobserver ICC deteriorated by rating simply presence or absence, rather than a 4 point grade, of tenderness. CONCLUSION: A new method for quantifying dactylitis based on digital circumference and tenderness has been described. This instrument has shown good inter and intraobserver reliability. Further studies of responsiveness are now required.