Generating automated kidney transplant biopsy reports combining molecular measurements with ensembles of machine learning classifiers

We previously reported a system for assessing rejection in kidney transplant biopsies using microarray‐based gene expression data, the Molecular Microscope^® Diagnostic System (MMDx). The present study was designed to optimize the accuracy and stability of MMDx diagnoses by replacing single machine learning classifiers with ensembles of diverse classifier methods. We also examined the use of automated report sign‐outs and the agreement between multiple human interpreters of the molecular results. Ensembles generated diagnoses that were both more accurate than the best individual classifiers, and nearly as stable as the best, consistent with expectations from the machine learning literature. Human experts had ≈93% agreement (balanced accuracy) signing out the reports, and random forest‐based automated sign‐outs showed similar levels of agreement with the human experts (92% and 94% for predicting the expert MMDx sign‐outs for T cell–mediated (TCMR) and antibody‐mediated rejection (ABMR), respectively). In most cases disagreements, whether between experts or between experts and automated sign‐outs, were in biopsies near diagnostic thresholds. Considerable disagreement with histology persisted. The balanced accuracies of MMDx sign‐outs for histology diagnoses of TCMR and ABMR were 73% and 78%, respectively. Disagreement with histology is largely due to the known noise in histology assessments (ClinicalTrials.gov NCT01299168).     

Effects of a specific and long-acting renin inhibitor in the marmoset

Inhibition of renin was induced in conscious marmosets with CGP 29 287, Z-Arg-Arg-Pro-Phe-His-Sta-Ile-His-Lys (Boc)-OMe, a renin inhibitor with a prolonged duration of action. In vitro, CGP 29 287 is a potent inhibitor of primate plasma renin (inhibitory concentration, 50%: human = 1 X 10(-9) M; marmoset = 5 X 10(-9) M) and less potent against dog (2 X 10(-7) M) or rat (3 X 10(-5) M) plasma renin. CGP 29 287 is a weak inhibitor of other aspartic proteases such as porcine pepsin or bovine cathepsin D (inhibitory concentration, 50% = 4 X 10(-5) M). In furosemide-treated marmosets, CGP 29 287 lowered blood pressure and inhibited plasma renin activity during intravenous infusion and after intravenous bolus injection. The duration of action after intravenous injection was dose dependent and ranged from 1 hour after 0.1 mg/kg to more than 3 hours after 10 mg/kg. High doses of CGP 29 287 (100 mg/kg) were active after oral administration. In all experiments a close relation between inhibition of plasma renin activity and reduction of blood pressure was found. A maximum hypotensive response to CGP 29 287 was associated with complete inhibition of plasma renin activity, and the recovery of blood pressure was accompanied by recovery of plasma renin activity. The hypotensive effects of CGP 29 287 were smaller in untreated than in furosemide-treated marmosets. CGP 29 287 had no influence on blood pressure in marmosets after bilateral nephrectomy or after pretreatment with a converting enzyme inhibitor.(ABSTRACT TRUNCATED AT 250 WORDS)     

Infected common iliac artery aneurysm repaired in an infant with cadaveric vein graft

Aneurysms are rare in children. Causes include congenital, traumatic, inflammatory, and infectious etiologies. When and how to best surgically treat arterial aneurysms in a child remain unclear. We present the case of a 3-month-old child with an aneurysm of the left common iliac artery, which was first detected on abdominal ultrasound and was successfully repaired with a cadaveric vein graft.     

Normal coronary artery dimensions in Indians

Background There is no available data on normal coronary artery size in the Indian population. We attempted to establish a database for normal dimensions of the coronary artery segments during life by using quantitative coronary angiography and compared these with Western estimates of coronary artery size. Material and Methods Between december 2003 and June 2004, 94 patients who underwent quantitative coronary angiography for evaluation of symptoms of ischemic heart disease and were found to have no coronary artery disease form the sample size. Results The dimensions of branches in the left coronary system in our patients were less and those of the distal circumflex, and the proximal and distal left anterior descending coronary arteries were significantly greater than those of Indian Asians living in the United Kingdom and the native Caucasians but the dimensions of the right coronary artery were significantly greater in our patients. Conclusions Coronary artery dimensions for at least some branches of the left coronary system are similar to that reported in the West and the dimensions of the right coronary are greater. These findings contradict the general perception that Indians have smaller coronary arteries.     

Implantation of parathyroid carcinoma along fine needle aspiration track

Introduction Fine needle aspiration cytology is not a commonly employed diagnostic modality in the diagnosis of parathyroid tumors.Case report A 28 year old lady being followed-up for 5 years after en bloc resection of a parathyroid carcinoma presented with a nodule in the lower neck, away from the parathyroidectomy scar. The 1 cm isolated nodule was located in the muscular and subcutaneous plane and corresponded to the needle track of FNA performed on a neck nodule before the parathyroidectomy. On evaluation, she had mild hypercalcemia and high normal serum parathyroid hormone levels. FNAC and histology including immunohistochemistry for Chromogranin A after local excision of the nodule confirmed the nodule to be a recurrent parathyroid carcinoma along the needle track.Discussion To the best of the authors’ knowledge, this is only the second case of needle track implantation after FNA in parathyroid carcinoma reported to date. This case highlights the risk of engraftment of parathyroid tissue after FNA and cautions against the use of FNA as a preoperative diagnostic modality for the evaluation of parathyroid lesions.Drs. Agarwal and Dhingra have contributed equally, as joint first authors.     

Outcome of Unicondylar Knee Arthroplasty vs Total Knee Arthroplasty for Early Medial Compartment Arthritis: A Randomized Study

Background

With increasing number of patients with early osteoarthritis of knee opting for total knee arthroplasty (TKA), there has been increase in patients dissatisfied with surgical outcomes. It is being presumed that offering unicondylar knee arthroplasty (UKA) to them would improve outcomes.

Outcomes of Percutaneous Mechanical Thrombectomy of Arteriovenous Fistulas in Hemodialysis Patients

Thrombosis of arteriovenous fistulas is usually superimposed on underlying stenosis in the arterial anastomosis, draining vein, or central vein. Restoring the patency of thrombosed fistulas requires mechanical thrombectomy, in conjunction with angioplasty of the underlying lesion. We evaluated the success rate of percutaneous thrombectomy of fistulas at our medical center. We retrospectively queried a prospective, computerized vascular access database to identify 41 patients with thrombosed fistulas treated percutaneously. Technical success was defined as the ability to use the fistula for at least one dialysis session. Primary patency was defined as time to the next intervention, and secondary failure as the time to permanent fistula failure. Of the 41 thrombosed fistulas, 21 were in the forearm and 20 in the upper arm. Percutaneous thrombectomy was technically successful in 31 of 41 patients (76%). The technical success rate was similar for upper arm and forearm fistulas (85% vs. 66%, p = 0.43). An underlying stenotic lesion was present at the arterial anastomosis in 13 patients (31%), in the draining vein in 37 (90%), and in the central vein in 3 patients (7%). Twelve patients (29%) had concurrent stenoses at two locations. At 6 months, the primary patency was 20%, and the secondary patency was 54%. In conclusion, percutaneous treatment of thrombosed fistulas can restore fistula patency about three‐fourths of patients. However, the primary fistula patency is fairly short‐lived, and the fistulas require repeated interventions to achieve long‐term survival.     

Isolated Duodenal Rupture due to Go-Karting Accidents – Braking News

INTRODUCTION

Isolated duodenal injury due to blunt abdominal trauma is extremely rare. We present a series of three such injuries due to go-karting accidents, which presented to our hospital over 5 months.

CASE REPORTS

Between October 2007 and February 2008, three cases of D3/D4 duodenal rupture presented to our hospital after go-karting accidents. Trauma occurred as a result of the steering wheel impacting on the abdomen. All patients presented similarly with symptoms of epigastric and right upper quadrant pain. In all cases, computed tomography scanning was highly suggestive of duodenal injury and, in particular, demonstrated presence of retroperitoneal air centred around the duodenum. Treatment required laparotomy and operative repair in all cases.

CONCLUSIONS

Duodenal injury presents insidiously due to its retroperitoneal position. A low threshold for investigating patients presenting with epigastric and right upper quadrant pain should be adopted along with active clinical vigilance to exclude serious and life-threatening trauma after go-karting accidents.     

Evaluation of the clinical signs of anterior cruciate ligament and meniscal injuries

Background:

The diagnostic accuracy of anterior drawer (AD) sign, Lachman test and the pivot shift test for anterior cruciate ligament injury and McMurray test for medial and lateral meniscus is varied with sensitivity and specificity ranging from 2 to 100%. Generally, it is accepted that the pivot shift test is the most specific test to diagnose anterior cruciate ligament (ACL) tears and that the Lachman test is more sensitive than AD sign. This study was undertaken to calculate the sensitivity, specificity, positive predictive value, negative predictive value, and efficiency for the above-mentioned diagnostic tests.

Materials and Methods:

Twenty-eight male patients with clinical ACL injury were examined in the outpatient department and under anaesthesia, the findings were compared with arthroscopy.

Result:

The sensitivity and specificity for the Lachman test, AD sign and pivot shift test performed in the outpatient setting are 78.6 and 100%, 89.3 and 100%, and 75 and 100%, respectively. The sensitivity and specificity for the Lachman test, AD sign, and pivot shift test performed under anesthesia are 92.9 and 100%, 92.9 and 100%, and 100 and 100%, respectively. The sensitivity and specificity of the McMurray test for medial and lateral meniscus were 35.7 and 85.7% and 22.2 and 100%, respectively.

Conclusion:

The Lachman test, AD sign and pivot shift test are highly specific tests to diagnose ACL laxity in a non-acute setting; pivot shift test under anesthesia is the most sensitive and specific test for diagnosing ACL laxity in a non-acute setting and the McMurray test is not a sensitive test to diagnose meniscal injury in the presence of ACL injury.     

Bone metastases as the initial presentation of carcinoma of gall bladder: a rarity

Distant metastases are rare form of presentation of carcinoma gall bladder. Bony pain as initial presentation is quite unusual. A 50-year-old woman presented with the pain in right shoulder. Investigation showed metastatic adenocarcinoma in the head of humerus and the primary was found in the gall bladder. She received local radiotherapy for bone metastases and undergoing systemic chemotherapy. Carcinoma gall bladder is a common abdominal malignancy, mostly presenting in advanced stage with abdominal symptoms and obstructive jaundice. In presence of metastasis, the management is palliative and role of chemotherapy is limited for palliation symptoms.