Selective pudendal arteriography.

Selective pudendal arteriography is indicated in selected cases of male impotence when there is a strong presumption that peripheral arterial lesions are responsible for it. These lesions are classified as: (a) traumatic; (b) obstructive in thrombo-angiitis or atheroma, and (c) dysplasic. Selective arteriography will confirm the diagnosis and indicate the nature of the obstruction, its degree and extension.     

Dialyzed polymorphonuclear neutrophil oxidative metabolism during dialysis: a comparative study with 5 new and reused membranes

Dialyzed neutrophils were isolated at time 0, 5, 15 and 60 min after the onset of hemodialysis in patients successively treated on 5 new and reused membranes, that is cuprophan (CU), cellulose acetate (CA), polysulfone (PS), polycarbonate (PC) and polyacrilonitrile (PAN). Production of oxygen radicals was monitored by luminol and lucigenin-enhanced chemiluminescence (CL). During dialysis with CU and PC, cells remaining in circulation at the maximum neutropenia showed a significant decrease of luminol-enhanced CL, whether stimulated with opsonized zymosan or phorbol myristate acetate. This defect was transient and the responses normalized at 60 min or upon reuse of the membranes. Among the other membranes tested, only cells collected during the first use of PS showed an impaired CL response to phorbol myristate acetate, but not to opsonized zymosan. CL again normalized upon reuse. At 5 min of dialysis with each membrane, a plasma factor appeared that was able to stimulate oxygen radical production by autologous dialyzed and control cells. A dissociation between the oxidative responses of dialyzed neutrophils and neutropenia was observed depending on the nature of the membranes, suggesting that neutropenia is a multifactorial process in which oxygen radical production appears as an early disturbance.     

Desulfovibrio desulfuricans bacteremia in an immunocompromised host with a liver graft and ulcerative colitis

Desulfovibrio spp. are anaerobic, sulfate-reducing, nonfermenting, Gram-negative bacteria found in the digestive tract of humans. Identification of these species with conventional methods is difficult. The reported case of a Desulfovibrio desulfuricans bacteremia occurring in an immunocompromised host with ulcerative colitis confirms that this organism may be a possible opportunistic human pathogen.     

Evaluation of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for Identification of Nocardia Species

The identification of Nocardia species, usually based on biochemical tests together with phenotypic in vitro susceptibility and resistance patterns, is a difficult and lengthy process owing to the slow growth and limited reactivity of these bacteria. In this study, a panel of 153 clinical and reference strains of Nocardia spp., altogether representing 19 different species, were characterized by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). As reference methods for species identification, full-length 16S rRNA gene sequencing and phenotypical biochemical and enzymatic tests were used. In a first step, a complementary homemade reference database was established by the analysis of 110 Nocardia isolates (pretreated with 30 min of boiling and extraction) in the MALDI BioTyper software according to the manufacturer''s recommendations for microflex measurement (Bruker Daltonik GmbH, Leipzig, Germany), generating a dendrogram with species-specific cluster patterns. In a second step, the MALDI BioTyper database and the generated database were challenged with 43 blind-coded clinical isolates of Nocardia spp. Following addition of the homemade database in the BioTyper software, MALDI-TOF MS provided reliable identification to the species level for five species of which more than a single isolate was analyzed. Correct identification was achieved for 38 of the 43 isolates (88%), including 34 strains identified to the species level and 4 strains identified to the genus level according to the manufacturer''s log score specifications. These data suggest that MALDI-TOF MS has potential for use as a rapid (<1 h) and reliable method for the identification of Nocardia species without any substantial costs for consumables.Nocardia spp. are ubiquitous bacteria dispersed in vegetation, dust, soil, freshwater, and salt water that are isolated with increasing frequency from clinical specimens, especially those from immunocompromised patients (1).The taxonomy of the genus Nocardia has undergone major changes during the last decades, and currently more than 50 species have been characterized by phenotypic and molecular methods, besides a number of unnamed genomospecies (2). Not all of them have been found in humans, and Nocardia asteroides, previously considered the species most frequently isolated from clinical specimens, has been shown to be heterogeneous and has been divided into several species (2). Moreover, several additional species of human origin have been recently described and reported (5, 6).The routine identification of Nocardia strains to the species level by conventional phenotypical methods is a fastidious and time-consuming process owing to the limited biochemical reactivity of these organisms, often requiring 1 or more days to complete identification. Moreover, the available tests may be difficult to interpret and inconclusive and require dedicated trained staff. In order to overcome these drawbacks, molecular methods such as 16S rRNA gene sequencing and PCR-restriction fragment length polymorphism analysis of both the 65-kDa heat shock protein-encoding gene (hsp65) and the 16S rRNA gene have been recently advocated for Nocardia species identification (3). However, these methods remain accessible to reference laboratories only and are difficult to implement for routine bacterial identification in a clinical laboratory.Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) can analyze the protein composition of a bacterial cell and has emerged as a new technology for species identification. By measuring the exact sizes of peptides and small proteins, which are assumed to be characteristic for each bacterial species, it allows determination to the species level within a few minutes when the analysis is performed on whole cells, cell lysates, or crude bacterial extracts (8). Through the improvement of the technique, MALDI-TOF MS has proved over the recent years to be a rapid, accurate, easy-to-use, and inexpensive method for the universal identification of microorganisms (11). Until now, MALDI-TOF MS has been challenged for the identification of various groups of microorganisms, including Gram-positive bacteria, Enterobacteriaceae, Gram-negative nonfermenters, mycobacteria, anaerobes, and yeasts (8, 9, 11-13). In this respect, the use of MALDI-TOF MS as a tool for the identification of fastidious, slow-growing organisms such as Nocardia species, which are notoriously difficult to identify by conventional tests, in the routine laboratory appeared to us of major interest. One factor limiting the use of MALDI-TOF MS remains the limited availability of reference data sets for microorganisms that are infrequently isolated from clinical specimens, and it has been shown previously that the absence or the availability of only a small number of isolates of a given species in the reference database may account for most of the cases in which no identification can be obtained by the MALDI-TOF MS method (11).In this study, we therefore aimed to establish a large reference database for the MALDI-TOF MS-based identification of Nocardia species isolates. In a first step, we developed a simple modified extraction procedure based on boiling for 30 min, followed by ethanol-formic acid extraction, and we generated our own spectrum database issued from a large collection of clinical and reference Nocardia sp. isolates. Following the establishment of our reference database, we subsequently evaluated the methodology against 43 blind-coded clinical isolates of Nocardia species that were analyzed by phenotypical, biochemical, and enzymatic tests and by full-length 16S rRNA gene sequencing, which was used as the reference identification method.     

Germline <Emphasis Type="Italic">MUTYH</Emphasis> gene mutations are not frequently found in unselected patients with papillary breast carcinoma

MUTYH- associated polyposis (MAP) is an autosomal recessive disease, which predisposes to polyposis and colorectal cancer. There is a trend towards an increased risk of breast cancer in MAP patients, with a remarkable proportion of papillary breast cancers. To determine whether MUTYH mutations are associated with this specific and rare type of breast cancer, 53 unselected patients with papillary breast cancer were analyzed for founder mutations in the MUTYH gene. No germline mutations were identified, indicating that biallelic MUTYH mutations are not a frequent underlying cause for the development of papillary carcinomas of the breast.     

Germline MUTYH gene mutations are not frequently found in unselected patients with papillary breast carcinoma

MUTYH-associated polyposis (MAP) is an autosomal recessive disease, which predisposes to polyposis and colorectal cancer. There is a trend towards an increased risk of breast cancer in MAP patients, with a remarkable proportion of papillary breast cancers. To determine whether MUTYH mutations are associated with this specific and rare type of breast cancer, 53 unselected patients with papillary breast cancer were analyzed for founder mutations in the MUTYH gene. No germline mutations were identified, indicating that biallelic MUTYH mutations are not a frequent underlying cause for the development of papillary carcinomas of the breast.     

Laboratory detection of macro-aspartate aminotransferase: case report and evaluation of the PEG-precipitation method

BackgroundChronic elevated AST without other signs of liver disease, cardiac or skeletal abnormalities, is suggestive for macro-AST. Laboratory detection can be performed by gel filtration chromatography, ultrafiltration or precipitation with polyethylene glycol (PEG).Patient and methodsA healthy 27 year-old female was referred because of chronic elevated AST (116–704 U/L) without other abnormalities. Macro-AST positivity was suspected since AST was no longer measurable in the supernatant of a serum sample (< 3 U/L) after PEG precipitation. Optimization of this method included analysis of proteins and lipids precipitated, testing the effect of different PEG concentrations and centrifugation times. 25% (m/v) PEG solution gave the most reliable results. No significant difference was seen between 10 and 30 min centrifugation time. A reference range was obtained by analysis of 31 normal patient samples (mean % PEG precipitation activity 35.1% with 95% confidence limits of 14.5–62.5%). Retrospective analysis of 1371 patient samples with elevated AST revealed one other positive patient sample.ConclusionEarly recognition of macro-AST, proven by simple PEG precipitation, can avoid time-consuming and invasive investigations.