Emphysematous Pyelonephritis: Disparities observed in the use of percutaneous drainage techniques

Objectives: The recent drop in the mortality rates of emphysematous pyelonephritis, a serious medical condition, is attributable to renal percutaneous drainage (PCD) techniques that have also reduced the necessity for surgery. Since the difference in the objectives of the two specific techniques, i.e. PCD and percutaneous nephrostomy (PCN), is often overlooked, this study aimed to highlight the inconsistencies in the use of these two techniques. Methods: A retrospective study of 17 patients was conducted over a 10-year period from January 2008 to December 2017 at The Royal Hospital, Muscat, Oman. All patients had undergone abdominal computerised tomography. The obtained images were reviewed and categorised based on Huang and Tseng’s classification. Results: From the sample, 13 patients (76%) were categorised as class I and II, three (17%) as class IIIA and one (6%) as class IIIB. Five patients from the class I and II categories underwent drainage of the pelvicalyceal system, four by PCN and one by a double-J stent insertion. PCN was performed on all the class IIIA and IIIB patients. One class IIIB patient required PCD for localised gas and fluid collection but later underwent emergency nephrectomy. There were no mortalities. Conclusion: The favourable outcome of this study was in keeping with those of the more recent studies. However, despite the present classifications and guidelines, wide variations were reported in the use of percutaneous drains with PCD, ranging from 2.5–91%. The lack of precise guidelines may be a cause of these disparities in clinical management. Keywords: Renal Infection; Pyelonephritis; Drainage; Percutaneous Nephrostomy; Oman.

Validity of Prostate Health Index and Percentage of [-2] Pro-Prostate-Specific Antigen as Novel Biomarkers in the Diagnosis of Prostate Cancer: Omani Tertiary Hospitals Experience

Objectives: Prostate cancer is the leading cancer in older men. The Ministry of Health Oman Cancer Incidence Registry 2013 lists cancer of the prostate as the first most common cancer in males. Therefore, early detection is important and prostate-specific antigen (PSA) is widely used as an established laboratory test. However, despite its wide use, its value in screening, particularly in asymptomatic males, is controversial when considering the risks and benefits of early detection. Methods: This prospective, observational study included 136 males (67.0±8.9 years; range 45–90) who were scheduled for a prostate biopsy in two different tertiary care teaching hospitals in Oman: the Royal Hospital and Sultan Qaboos University Hospital. Blood specimens from these patients were collected at the same setting before obtaining a prostatic biopsy. Three PSA markers (total PSA (tPSA), free PSA (fPSA), and [-2]proPSA (p2PSA)) were measured and the Prostate Health Index (phi) calculated. The histopathological report of the prostatic biopsy for each patient was obtained from the histopathology laboratory of the concerned hospital along with clinical and laboratory data through the hospital information system. Results: Phi has the highest validity markers compared with other prostate markers, with a sensitivity of 82.1%, specificity of 80.6%, and area under the curve (AUC) value of 0.81 at a cutoff of 41.9. The other prostatic markers showed sensitivities and specificities of 78.6% and 25.9% for tPSA; 35.7% and 92.6% for %fPSA; and 64.3% and 82.4% for %p2PSA, respectively. The AUCs at the best cutoff values were 0.67 at 10.1 µg/L for tPSA; 0.70 at 11.6% for %fPSA; and 0.55 at 1.4% for %p2PSA. An association between phi values and aggressiveness of prostate malignancy was noted. Of the 28 patients with prostate cancer, 22 patients had tPSA > 4 µg/L. However, no patient had phi in the low-risk category, and five, six, and 17 patients had phi in the moderate-, high-, and very high-risk categories, respectively. Conclusions: Phi outperforms tPSA and fPSA when used alone or in combination, and appears to be more accurate than both markers in excluding prostate cancer before biopsy. Use of this biomarker helps clinicians to avoid unnecessary biopsies, particularly in patients with gray-zone tPSA level. Phi is the strongest marker that correlates proportionally with Gleason Score; therefore, it is also useful in predicting the aggressiveness of the disease. This is the first reported experience for the use of p2PSA and phi in Oman, the Middle East, and North Africa

The Drag-free CubeSat

A drag-free spacecraft utilizes a Gravitational Reference Sensor (GRS) to shield an internal free-floating test mass (TM) from (a) external disturbances and (b) from disturbances caused by the spacecraft itself. The GRS measures the position of the spacecraft with respect to the TM and a feedback control system commands thrusters to maintain that position. In principle, the test mass is then completely freed from non-gravitational disturbances so that it and its “tender” spacecraft follow a pure geodesic. To date, three drag-free spacecraft have flown: TRIAD I in 1972, which provided the first navigation by satellite, Gravity Probe B in 2004, which tested predictions of Einstein’s general relativity theory, and the 2009 geodesy mission, GOCE (Steady-State Ocean Circulation Explorer). Next generation GRS technology for geodesy, fundamental physics and gravitational wave detection in space, has been under development at Stanford since 2004. Most recently a small scale instrument, called the 1U GRS has been proposed for a 3U CubeSat primarily for Earth aeronomy and geodesy applications. The 1U GRS consists of a 25 mm diameter spherical test mass housed inside a 50 mm cubic cavity. The sphere\u27s position is sensed with a LED-based differential optical shadow sensor, its electric charge is controlled by photoemission using UV LEDs, and the spacecraft position is maintained with respect to the sphere using a cold gas micro-propulsion system. This paper highlights the history, applications, design, and laboratory technology development for this proposed CubeSat mission