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At least 253 records · Page 14Linked to original sources
PubMed1999

The rate of plasmin formation after in vitro clotting is inversely related to lipoprotein(a) plasma levels.

Lipoprotein(a) levels are largely genetically determined and are linked to increased risk of coronary artery disease. The hypothesis that elevated lipoprotein(a) levels lead to decreased fibrinolysis, due to the close structural homology with plasminogen, could in part explain the genesis of this risk, although contrasting results have been obtained in different studies. The aim of our study was to evaluate whether the rate of plasmin formation, enhanced in vitro by a fixed amount of human tissue plasminogen activator after clotting, was related to plasma lipoprotein(a) levels in 45 healthy subjects. Aliquots of human plasma were clotted with calcium chloride and thrombin followed by addition of tissue plasminogen activator. We then measured the time course of plasmin formation, determined as hydrolysis of H-D-valyl-L-leucyl-L-lysine-p-nitroanilide dihydrocortide (S-2251). The log of lipoprotein(a) level was negatively related to the rate of plasmin formation (r(s)=-0.46, P=0. 002), and multiple regression analysis indicated that this relationship was not influenced by the amount of plasminogen, fibrinogen, plasminogen activator inhibitor-1, tissue plasminogen activator, or by the size of apo(a) isoforms. These data support the concept that lipoprotein(a) can inhibit plasminogen activation and plasmin formation and can thereby play an important role in the genesis of atherosclerosis as an antifibrinolytic agent.

Adult↗
PubMed2005

HER2 amplification and overexpression is not present in pediatric osteosarcoma: a tissue microarray study.

The HER2 gene, located on 17q, encodes a 185-kD transmembrane tyrosine kinase receptor. Amplification of this gene with overexpression of the gene product occurs in about 30% of cases of breast cancer and is considered to be a poor prognostic indicator for this tumor. Results for HER2 expression in osteosarcoma are controversial, with some studies reporting up to 61% of positive cases and others reporting only negative results. Further, expression of HER2 is reported to be a favorable prognostic indicator by some groups and unfavorable by others. The present study used tissue microarrays containing 34 samples of osteosarcoma from 18 patients to analyze HER2 expression by immunohistochemistry and gene copy number by chromogenic in situ hybridization. The microarray included 13 pretreatment biopsies, 11 posttreatment resection specimens, and 10 resected metastases and comprised 18 osteoblastic, 6 chondroblastic, 5 fibroblastic, and 5 mixed subtypes. HER2 protein expression was seen in 4 of 34 (12%) tumor samples that originated from 2 of 18 patients (11%). The staining pattern was consistently weak and focal, and immunohistochemical overexpression of the HER2 protein, defined as complete membrane positivity, was never observed. Further, the presence of HER2 gene amplification was not detected in any osteosarcoma by chromogenic in situ hybridization. Therefore, therapies based on antibodies directed against the HER2 protein are unlikely to have much value in the treatment of pediatric osteosarcomas. From a technical standpoint, this study also demonstrates the value of tissue microarrays in screening tumors at the protein and gene levels using conventional light microscopy.

Adolescent↗
PubMed2002

Comparative evaluation of two commercial chromogenic media for detection and presumptive identification of urinary tract pathogens.

The performance of two commercial chromogenic media for the isolation and presumptive identification of urinary tract pathogens, the CPS ID2 (bioMérieux, France) and the CHROMagar Orientation (BBL Becton Dickinson, USA), was evaluated and compared with that of cystine-lactose-electrolyte-deficient agar and tryptic soy agar with 5% sheep blood. The detection, determination of bacterial counts, and presumptive identification of bacteria causing urinary tract infections were evaluated in 3,000 urine specimens. The two chromogenic media showed excellent correlation with the standard media for the detection and the bacterial count of urinary pathogens. The Escherichia coli strains produced the expected colour on the CHROMagar Orientation and the CPS ID2 media in 99% and 90% of the cases, respectively. The Klebsiella-Enterobacter-Citrobacter and the Proteus-Morganella-Providencia groups were easily identified on both chromogenic media, but further biochemical tests were needed to differentiate them to a species level. Both media enabled the differentiation, with varying degrees of difficulty, of Pseudomonas spp. strains from members of the family Enterobacteriaceae. All isolates of Enterococcus spp. were correctly identified and were easily distinguished from the Streptococcus agalactiae isolates. Staphylococcus saprophyticus isolates were easy to identify only on the CHROMagar Orientation medium. No substantial difference was observed when comparing the results of the susceptibility tests, which were performed according to the standardized disk diffusion method as described by the National Committee for Clinical Laboratory Standards, for colonies recovered from the blood agar versus those recovered from the chromogenic media. In conclusion, the CPS ID2 and CHROMagar Orientation media enabled excellent detection, count determination, and presumptive identification of urinary pathogens, both in pure and mixed cultures, and reliable and accurate antimicrobial susceptibility testing directly from primary isolates. Moreover, these media allowed a remarkable reduction in the workload and a significant savings of time. On the basis of their performance, these media can replace the standard primary plating media used in the routine diagnosis of urinary tract infections.

Candida↗
PubMed2006

Evaluation of a new chromogenic medium for isolation and identification of common urinary tract pathogens.

In the study presented here, a new chromogenic medium (CPS ID 3; bioMérieux, Marcy l'Etoile, France) was compared to routine media for the isolation, identification and antimicrobial susceptibility testing of bacteria recovered from urine specimens, and a cost analysis was performed. Escherichia coli, Proteeae tribe, Pseudomonas aeruginosa, Enterococcus spp. and Streptococcus agalactiae grew on the chromogenic medium as typical differentiated colonies and were accurately identified even in mixed cultures. Although the similarity of colors produced by isolates belonging to the Klebsiella, Enterobacter, Serratia and Citrobacter (KESC) group prevents differentiation among them, members of KESC were easily identified as coliforms. No substantial difference was observed when comparing the results of antimicrobial susceptibility testing performed on colonies selected from reference media versus CPS ID 3. Use of the new medium was associated with a savings of 75% over the conventional methods and the API system. Furthermore, this medium facilitated a remarkable reduction in the laboratory workload and consequently resulted in additional time and cost savings.

Anti-Bacterial Agents↗
PubMed2000

Clinical evaluation of a novel chromogenic agar dipslide for diagnosis of urinary tract infections.

The performance of a novel dipslide (DipStreak; Novamed, Israel) consisting of chromogenic agar (Uriselect 3; Sanofi Pasteur, France) and blood agar media was evaluated prospectively and compared to that of conventional urine culture for the diagnosis of urinary tract infection. A total of 1070 clean-catch urine specimens obtained from 251 hospitalized patients and 819 outpatients were processed. The overall performance of the DipStreak was as follows: sensitivity, 95.7%; specificity, 99.2%; agreement, 89.8%; accuracy, 98%; positive predictive value, 98.5%; and negative predictive value, 97.7%. A total of 270 urine specimens were positive by both DipStreak and conventional culture. The chromogenic agar allowed rapid identification of organisms in 211 (78.1%) cultures, while isolates in the other 59 (21.9%) cultures remained unidentified. The results indicate that the DipStreak device coupled with the Uriselect 3 agar represents a convenient and accurate method for inoculation of urine specimens, quantitation of bacteria, diagnosis of significant bacteriuria, and presumptive identification of isolates.

Bacteria↗
PubMed1999

Comparative evaluation of five chromogenic media for detection, enumeration and identification of urinary tract pathogens.

Five chromogenic agar plates--CPS ID2 medium (bioMérieux, France), CHROMagar Orientation medium (Becton Dickinson, France), UriSelect3 medium (Sanofi Diagnostics Pasteur, France), Rainbow Agar UTI medium (Biolog, USA) and Chromogenic UTI medium (Oxoid, Germany)--for the detection, enumeration and direct identification of urinary tract pathogens were compared using 443 urine specimens at two hospital laboratories. The enumeration of microorganisms was consistent on the five media for 403 of the 477 (84.5%) microorganisms. Chromogenic UTI, CPS ID2, UriSelect3, CHROMagar Orientation and Rainbow UTI gave detection rates of 98.3%, 97.9%, 97.3%, 96.9% and 94.1%, respectively, with some problems in yeast growth occurring on Rainbow UTI agar and problems in Staphylococcus spp. growth occurring on UriSelect3. For the direct identification of Escherichia coli, sensitivities were 93.8%, 88.5%, 86.1% and 82.2% for CHROMagar Orientation, CPS ID2, UriSelect3 and Rainbow UTI, respectively. Chromogenic UTI medium did not allow the accurate identification of Escherichia coli, since the indole reaction cannot be applied to this medium. Depending on the media, Enterococcus spp. could be identified at the genus or the species level. Slight differences were detected in the presumptive identification of the Proteus-Morganella-Providencia group and the Klebsiella-Enterobacter-Serratia group. Additionally, on Rainbow UTI agar, 12 of 20 Klebsiella pneumoniae strains and two of nine Pseudomonas aeruginosa strains were correctly identified. In conclusion, CPS ID2 medium and CHROMagar Orientation medium showed similar performance overall, while the UriSelect3, Rainbow UTI and Chromogenic UTI media require some improvement.

Agar↗
PubMed2001

Evaluation of a new chromogenic medium for the isolation and presumptive identification of Salmonella species from stool specimens.

The performance of BBL CHROMagar Salmonella (Becton Dickinson, France), a new selective chromogenic medium for the isolation and presumptive identification of Salmonella spp., was evaluated. On this medium, which is a modification of CHROMagar Salmonella (CHROMagar Microbiology, France) with enhanced selectivity, the colonies of Salmonella are stained in mauve (rose-violet), while those of other organisms appear in blue-green or are not stained by any of the chromogens of the medium. The medium was evaluated with a total of 176 strains of Salmonella and other organisms, consisting of 18 reference strains and 158 clinical isolates. All Salmonella strains except subspecies IIIa and IIIb strains and Salmonella Gallinarum yielded typical mauve colonies. During the evaluation with 107 known positive and 332 unknown stool specimens in a clinical laboratory, a total of 115 and 105 Salmonella isolates were obtained on BBL CHROMagar Salmonella and Hektoen enteric agar, respectively. From the known positive stool specimens, 92 true positive cultures were obtained on BBL CHROMagar Salmonella and 89 on Hektoen enteric agar, yielding sensitivities of 86 and 83%, respectively. From the unknown stool specimens, a total of 27 Salmonella isolates were obtained, with 23 isolated from BBL CHROMagar Salmonella and 16 from Hektoen enteric agar by direct plating (sensitivity 85 and 59%, specificity 99 and 97%, respectively). Seroagglutination tests could be performed directly from BBL CHROMagar Salmonella. Compared to conventional isolation media, the time needed for confirmatory biochemical and serological tests was shortened by about 1 day when BBL CHROMagar Salmonella was used. On the basis of these results, the medium can be recommended for the primary isolation and presumptive identification of Salmonella spp. from clinical stool specimens.

Bacteriological Techniques↗
PubMed2006

Simultaneous two-color spectral fluorescence lymphangiography with near infrared quantum dots to map two lymphatic flows from the breast and the upper extremity.

Due to their small size and poor access, the lymphatic function has been difficult to study in vivo. Especially difficult is the mapping of lymphatic drainage from two basins into the same node. Quantum dots can be used to perform multicolor images with high fluorescent intensity and are of a nano-size size suitable for lymphatic imaging via direct interstitial injection. Here we show simultaneous two-color in vivo wavelength-resolved spectral fluorescence lymphangiography using two near infrared quantum dots with different emission spectra, which allow non-invasive and simultaneous visualization of two separate lymphatic flows draining the breast and the upper extremity and variations in the drainage patterns and the water sheds within the axillary node. Two-color spectral fluorescence lymphangiography can provide insight into mechanisms of drainage from different lymphatic basins that may lead to sentinel lymph nodes detection of the breast cancer as well as prevention of complications such as lymphedema of the arm.

Animals↗
PubMed2005

Analysis of chromosome 7 in adult and pediatric ependymomas using chromogenic in situ hybridization.

Few studies have yielded reliable data that distinguish between ependymal neoplasms based on molecular genetic attributes. The present study utilizes chromogenic in situ hybridization (CISH), a relatively recent hybridization technique, to retrospectively examine chromosome 7-copy number in pediatric and adult ependymomas. Of the 27 hybridizations, polysomy of chromosome 7 was detected in 10 out of 15 (66%) adult ependymomas, and in only three out of 12 (25%) pediatric lesions. All myxopapillary ependymomas showed polysomy. The remaining tumors were diploid. The authors conclude that (1) there are distinct genetic subsets of ependymoma, in particular, increases in copy number of chromosome 7 are almost exclusively found in myxopapillary ependymoma, and that (2) CISH is a rapid and sensitive method of stratifying morphological variants of ependymoma and potentially other central nervous system (CNS) tumors. These results encourage further investigations with CISH on a larger scale to determine its merit as an ancillary diagnostic and prognostic tool.

Adult↗
PubMed1997

Chromogenic assay for phospholipase D from Streptomyces chromofuscus: application to the evaluation of substrate analogs.

A rapid and convenient chromogenic assay for phospholipase D from Streptomyces chromofuscus (PLDSc) has been developed that converts the choline generated from the enzyme-catalyzed hydrolysis of phospholipids into a chromogenic dye. By quenching the reaction with EDTA at defined times, an initial rate curve is produced from which a kcat and K(m) can be readily derived. This assay has been applied to the biological evaluation of several substrate analogs, all of which appear to be activators rather than substrates or inhibitors of this enzyme. Performing the assay in 96-well microtiter plates allows for the easy screening of potential effectors of this enzyme.

Choline↗
PubMed2006

Evaluation of S. aureus ID, a chromogenic agar medium for the detection of Staphylococcus aureus.

BACKGROUND: Screening for staphylococci among various patient populations has become important for appropriate therapeutic management and for control of nosocomial infections. The purpose of this study is to evaluate the in vitro sensitivity and specificity of a chromogenic agar medium, S. aureus ID (bioMérieux, France), for the identification of Staphylococcus aureus. MATERIALS AND METHODS: A well-defined collection of S. aureus and coagulase-negative staphylococci (CNS) was used. The methicillin-resistant S. aureus (MRSA) isolates were collected in The Netherlands and all had a unique typing pattern. The methicillin-susceptible S. aureus (MSSA) and CNS were isolated from cultures of blood. The isolates were inoculated on Columbia agar plates with 5% sheep blood and incubated for 24 h at 35 degrees C. From the resulting cultures, a suspension of 0.5 McFarland was made and subsequently 10 mul was streaked on a S. aureus ID plate using a sterile loop. The results were read after 24 h and 48 h of incubation at 35 degrees C. Growth of colonies showing green coloration was considered to be positive (indicating S. aureus). RESULTS: A total of 519 S. aureus strains were tested (249 MSSA, 270 MRSA). The sensitivity to detect S. aureus was 96.5% (501/519) after 24 h and 97.5% (506/519) after 48 h. A total of 478 CNS were tested. The specificity was 98.5% (471/478) after 24 h and 98.3% (470/478) after 48 h. The differences between 24 h and 48 h incubation were not statistically significant. CONCLUSION: S. aureus ID is highly sensitive and specific to differentiate between S. aureus and CNS in vitro. Since the performance does not significantly differ between 24 h or 48 h of incubation, samples need only 1 day of incubation before optimal results can be obtained.

Agar↗
PubMed1988

Assay of bacterial endotoxin (lipopolysaccharide) in human amniotic fluid: potential usefulness in diagnosis and management of preterm labor.

The long-range goal of our research is to determine whether the presence of bioactive agents of infection in amniotic fluid may serve as sensitive indexes of the existence of infection as the cause of preterm labor in a given pregnancy. The aim of this study was to explore the possibility that bacterial endotoxin (lipopolysaccharide) could be detected and quantified in amniotic fluid. In particular, we sought to ascertain (1) if amniotic fluid could be collected in a manner to prevent endotoxin contamination, (2) whether there were inhibitors of lipopolysaccharide in amniotic fluid, and (3) if Limulus amebocyte lysate-based assays could be used to identify and quantify lipopolysaccharide in this fluid. We found that the Limulus amebocyte lysate assays (gelation assay and chromophore generation assay) were useful in the qualitative and quantitative analysis of lipopolysaccharide in amniotic fluids. Lipopolysaccharide-mediated generation of chromophore in the presence of amniotic fluid was accelerated strikingly compared with that of lipopolysaccharide in endotoxin-free water. In three amniotic fluid samples obtained during preterm labor, lipopolysaccharide was detectable in aliquots of 1 to 10 microliters by use of the gelation assay and lipopolysaccharide was quantifiable by use of chromophore generation assays. Two of these amniotic fluid samples were sterile as determined by bacteriologic examination; in the third sample, Fusobacterium species was identified. We suggest that these assays may be extremely useful in the identification of lipopolysaccharide in amniotic fluid. Indeed, lipopolysaccharide may serve as one marker of infection useful in establishing the cause of preterm labor.

Amniotic Fluid↗
PubMed1982

Relationship between pancreatic and serum amylase in basal conditions and during stimulation in man. Report of a new intraoperative technique.

The correlation between serum amylase and pancreatic amylase secretion was studied in two patients. Both patients underwent sphincterotomy, and the pancreatic duct was cannulated with a polyethylene tube. The tube was left in place for 15 to 21 days. The rate of amylase secretion over 7 days was studied in response to (1) a standard meal, (2) duodenal acidification, (3) scalar doses of cholecystokinin, (4) scalar doses of secretin, and (5) scalar doses of secretin with simultaneous infusion of cholecystokinin. Blood samples were collected during the tests to measure serum amylase. No significant correlation was shown between blood concentration and output of amylase in any of the tests. Our findings show that under normal conditions serum amylase levels are not influenced by pancreatic secretion and suggest that serum amylase concentration is not related to pancreatic exocrine secretion.

Adult↗
PubMed1978

Action of endo-alpha-N-acetyl-D-galactosaminidase on synthetic glycosides including chromogenic substrates.

The synthetic glycosides, p-nitrophenyl- and o-nitrophenyl-2-acetamido-2-deoxy-3-O-beta-D-galactopyranosyl-alpha- D-galactopyranosides, were found to be effective chromogenic substrates for an endo-alpha-N-acetyl-D-galactosaminidase. We did not experience any problems when these substrates were used for the screening of column fractions during the purification of the endoenzyme from Diplococcus pneumoniae culture filtrates. However, it should be pointed out that a combination of exo-beta-galactosidase, capable of cleaving beta 1-->3 linkages, and an exo-alpha-N-acetyl galactosaminidase would also liberate nitrophenol from the above substrates. The enzyme had no action on several other synthetic glycosides tested indicating the strict specificity of this enzyme for the disaccharide Gal beta-->GalNAc linked via an alpha-linkage to the aglycone. The enzyme was inactive when the aglycone was methanol but shows activity against the glycosides of phenol, nitrophenols, serine, and threonine. The use of p-nitrophenyl-2-acetamido-2-deoxy-3-O-beta -D-galactopyranosyl-beta-D-galactopyranoside, which is a competitive inhibitor of the endoenzyme, as an affinity ligand for the purification of the enzyme is described.

Affinity Labels↗