Detection and Differentiation of Xanthomonas translucens Pathovars translucens and undulosa from Wheat and Barley by Duplex Quantitative PCR

Two probe-based quantitative PCR (qPCR) systems, namely P-Xtt and P-Xtu, were developed to diagnose cereal bacterial leaf streak pathogens Xanthomonas translucens pv. translucens and pv. undulosa, respectively. P-Xtt is specific to pv. translucens, and P-Xtu is specific to pv. undulosa, pv. cerealis, pv. secalis, and pv. pistaciae. P-Xtt and P-Xtu worked on all accessible strains of pv. translucens and pv. undulosa, respectively. Both systems could detect 100 copies of the target gBlock DNA. The two systems could be used in both singleplex qPCR and duplex qPCR with similar efficiencies. On genomic DNA from strains of various X. translucens pathovars, both singleplex and duplex qPCR could specifically detect and differentiate pv. translucens and pv. undulosa. The duplex qPCR could detect pv. translucens and pv. undulosa from genomic DNA of 1,000 bacterial cells. On infected barley and wheat grain samples and on one infected wheat leaf sample, the duplex qPCR showed similar efficiency compared to a previously published qPCR system but with the additional capability of pathovar differentiation. The duplex qPCR system developed in this study will be useful in studies on bacterial leaf streak and detection/differentiation of the pathogens.

Phylogenomic Insights on the Xanthomonas translucens Complex, and Development of a TaqMan Real-Time Assay for Specific Detection of pv. translucens on Barley

The reemergence and spread of Xanthomonas translucens, the causal agent of bacterial leaf streak in cereal crops and wilt in turfgrass and forage species, is a concern to growers in the United States and Canada. The pathogen is seedborne and listed as an A2 quarantine organism by EPPO, making it a major constraint to international trade and exchange of germplasm. The pathovar concept of the X. translucens group is confusing due to overlapping of plant host ranges and specificity. Here, comparative genomics, phylogenomics, and 81 up-to-date bacterial core gene set (ubcg2) were used to assign the pathovars of X. translucens into three genetically and taxonomically distinct clusters. The study also showed that whole genome-based digital DNA-DNA hybridization unambiguously can differentiate the pvs. translucens and undulosa. Orthologous gene and proteome matrix analyses suggest that the cluster consisting of graminis, poae, arrhenatheri, phlei, and phleipratensis is very divergent. Whole-genome data were exploited to develop the first pathovar-specific TaqMan real-time PCR tool for detection of pv. translucens on barley. Specificity of the TaqMan assay was validated using 62 Xanthomonas and non-Xanthomonas strains as well as growth chamber-inoculated and naturally infected barley leaves. Sensitivity levels of 0.1 pg (purified DNA) and 23 CFUs per reaction (direct culture) compared favorably with other previously reported real-time PCR assays. The phylogenomics data reported here suggest that the clusters could constitute novel taxonomic units or new species. Finally, the pathovar-specific diagnostic tool will have significant benefits to growers and facilitate international exchange of barley germplasm and trade.

Genetic diversity and population structure of Leptosphaeria maculans isolates in Western Canada

Leptosphaeria maculans is a serious concern for canola production worldwide. For effective disease management, knowledge of the pathogen's genetic variability and population structure is a prerequisite. In this study, whole-genome sequencing was performed for 162 of 1590 L. maculans isolates collected in the years 2007-2008 and 2012-2014 in Western Canada. DNA variants in genome-wide and specific regions including avirulence (Avr) genes were characterized. A total of 31,870 high-quality polymorphic DNA variants were used to study L. maculans genetic diversity and population structure. Cluster analysis showed that 150 isolates were clustered into 2 main groups and 4 subgroups by DNA variants located in either Avr or small secreted protein-encoding genes and into 2 main groups and 6 subgroups by genome-wide variants. The analysis of nucleotide diversity and differentiation also confirmed genetic variation within a population and among populations. Principal component analysis with genome-wide variants showed that the isolates collected in 2012-2014 were more genetically diverse than those collected in 2007-2008. Population structure analysis discovered three distinct sub-populations. Although isolates from Saskatchewan and Alberta were of similar genetic composition, Manitoba isolates were highly diverse. Genome-wide association study detected DNA variants in genes AvrLm4-7, Lema_T86300, and Lema_T86310 associated with the years of collection.

Comparison of sonograms and liver histologic findings in patients with chronic hepatitis C virus infection

Gray scale ultrasonographic images of the liver were correlated with histologic findings in patients with chronic hepatitis C virus infection. The gray scale patterns of 64 livers with chronic hepatitis C virus infection were categorized as normal, fatty, fibrofatty, fibrotic, or inflammatory and were graded as mild, moderate, or severe. Liver biopsy specimens also were analyzed for the presence of fat, inflammation, and fibrosis and graded similarly. No correlation was found between fatty and fibrofatty sonographic findings with any of the three histologic patterns. Correlations were found between fibrotic sonographic findings and both fibrotic and inflammatory histologic findings (r = 0.27; P = 0.03). Although some pathologic features of liver disease were detected by ultrasonography, no useful correlation was noted between results of sonography and histologic examination.

Prevalence of asymptomatic cholelithiasis and risk of acute cholecystitis after kidney transplantation

Prophylactic cholecystectomy for asymptomatic cholelithiasis is sometimes required before transplantation. However, there is little indication in the literature that transplant recipients are at any greater risk than individuals in the general population. Between January 1990 and December 1993, 211 renal transplant recipients underwent duplex sonography. All were asymptomatic. Twenty-one had positive findings: gallstones were found in 15 patients (7.11%) and sludge was found in 6 (2.84%). Of gallstone patients, seven (3%) were men and eight (4%) were women. One gallstone patient also had diabetes mellitus. The mean age by gender of the patients with calculi was 54 years for men and 38 years for women. Thirteen of the 15 patients with calculi (87%) have remained asymptomatic. Two patients (one diabetic) developed acute cholecystitis and underwent uncomplicated laparoscopic cholecystectomy. Patients with sludge were similar in gender and age to patients with gallstones; one patient had diabetes. No sludge patients became symptomatic. The incidence and morbidity of gallstones after kidney transplantation are low. Prophylactic cholecystectomy in asymptomatic patients before transplantation is not justified.

Testicular feminization: radiologic considerations in a unique form of cryptorchidism

A case report of complete testicular feminization is presented. The medical and radiological characteristics of this condition which distinguish it from male cryptorchidism and other disorders of sexual differentiation are discussed. To our knowledge, only three previous case reports have been published in the radiology literature. Our report is the first to describe MRI findings.

Venous invasion in renal vein leiomyosarcoma: case report and review of the literature

Tumors arising from veins are rare, usually present with nonspecific clinical and imaging findings and almost universally show histology of leiomyosarcoma. This twentieth reported case of primary renal vein leiomyosarcoma demonstrates invasion of the renal vein with endoluminal propagation of tumor into the infrahepatic inferior vena cava (IVC), an unreported manifestation. The combination of CT, ultrasound, and angiographic studies allowed differentiation from renal cell carcinoma by suggesting a tumor arising from the renal vein.

Utero-vaginal hypoplasia. Sonographic, embryologic and clinical considerations

Congenital absence of hypoplasia of the uterus is a cause of primary amenorrhea in approximately 15% of cases. Ultrasound is often employed as an early imaging modality in the evaluation of patients with primary amenorrhea. Demonstration of total absence or marked hypoplasia of the uterus in the presence of normal ovaries during pelvic ultrasound examination, suggests the diagnosis of congenital uterine aplasia or hypoplasia. Sonography may obviate the need for laparoscopy and for other imaging modalities. A case report of uterovaginal hypoplasia in association with anal atresia and recto-vaginal fistula is presented, and the value of ultrasound in the diagnosis of this entity is discussed. The embryology and clinical features of this anomaly are also reviewed.

Renal peripelvic multicystic lymphangiectasia

Renal peripelvic multicystic lymphangiectasia is an unusual benign peripelvic fluid collection. The sonographic appearance, etiology, and differential diagnosis of peripelvic fluid collections are reviewed.

Prostatic carcinoma metastasis to the kidney: diagnosis by thin needle aspiration biopsy

Renal metastasis of prostatic origin is uncommon. The routes of metastatic spread are discussed. The efficacy and safety of thin needle aspiration biopsy in obtaining a premortem diagnosis are stressed.

Uterine perforation and embedding by intrauterine device: evaluation by US and hysterography

Uterine perforation and deep embedding by an intrauterine device (IUD) require exact determination of its location as a necessary step to safe and effective retrieval. Six cases of uterine perforation and four of embedding by an IUD were studied with ultrasonography (US) and hysterography. While US findings suggested the correct diagnosis of perforation in five of the six cases, hysterography yielded more exact diagnostic information. Deep embedding could only be diagnosed with hysterography. A classification of the types of perforation and an algorithm for diagnosing ectopic IUD are presented. Undue reliance on the sonographic appearance of an IUD in the center of the uterine image may lead to hazardous attempts at transvaginal removal of a device that is partly intramural. In this study, hysterography offered the most precise diagnostic information.

Uremic renal cystic disease: value of sonographic screening

A high incidence of bilateral cystic disease occurs in patients who have uremia of chronic renal disease that is being treated by intermittent hemodialysis. Complications of uremic cysts include cyst rupture, cyst hemorrhage, and the development of solid adenomatous or adenocarcinomatous lesions. Obtaining screening sonograms of the native kidneys of patients who have undergone transplantation and of the kidneys of patients who are receiving treatment by hemodialysis may be justified as a baseline for the routine monitoring of these high risk patients.

Accessory blood supply to the liver from the dorsal pancreatic artery: an unusual anatomic variant

A case of an accessory hepatic artery from the dorsal pancreatic artery is illustrated. A discussion of anatomic variations and embryology of the arterial blood supply to the liver from the celiac axis and aberrant blood supply from other vessels is presented with a consideration of the surgical and diagnostic significance of anatomic variance.

Unusual pelvic complications of a pancreatic pseudocyst

Pancreatic pseudocysts are notorious for their extension beyond the normal confines of the pancreatic bed. Their inferior extension has been known to involve kidney and ureter. However, involvement of the bladder and rectum is unique although understandable on anatomic grounds. We report an enormous pseudocyst with extension deep into the pelvis to displace both rectum and bladder.

Glomerulonephritis and nephrotic syndrome complicated by renal vein thrombosis and pulmonary emboli: report of two cases

Two patients with membranous glomerulonephritis and nephrotic syndrome developed renal vein thrombosis and pulmonary emboli. Renal disease appears to be the initiating event in this syndrome complex. While intravenous urography and radionuclide venography are useful, inferior venacavography followed by pulmonary angiography are the definitive diagnostic procedures. Follow-up cavography is indicated to monitor progress of anticoagulant therapy in clot dissolution or recurrence.

Calcification in polycystic disease

Two patients with polycystic disease demonstrated extensive calcification in the kidneys, liver, and spleen. Though flecks of calcium have been noted in the walls of such cysts, to the authors' knowledge, curvillinear, arcuate, and central amorphous calcifications have not been previously reported. Dystrophic calcifications may be diagnosed solely on the basis on polycystic disease with superimposed hemorrhage and infection. Polycystic disease should be included in the differential diagnosis of abdominal calcifications.