DNA transfection analyses (tumorigenicity assay) and hybridization to mutation specific oligonucleotide probes established point mutations in codon 61 of both, N-ras and Ki-ras genes in fresh leukemic cells of an AML patient. Concurrent activation of N-ras and Ki-ras sequences by point mutations in codons 12 were demonstrated for AML cell line Rc2a. Moreover, using a rapid and sensitive dot-blo...

A total of 206 serum samples from children (3-14 years old) living in the Amador County (La Chorrera District, Province of Panama) were screened by indirect immunofluorescence antibody test (IFAT) for the presence of antibodies against Trypanosoma cruzi. Positive sera were confirmed by recombinant enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. The presence of blood trypano...

A dot blot hybridization procedure with 32P-labeled whole chromosomal DNA of the type strains as probes was developed as a rapid and simple method for identification of intestinal Bacteroides species. Bacterial cells were fixed onto membrane filters by slight suction, treated with 0.5 N NaOH, and hybridized with these probes. Of 65 Bacteroides strains isolated from 19 human fecal specimens, whi...

The present study evaluates the time course of increased expression of the mRNA for glial fibrillary acidic protein (GFAP) within the dentate gyrus and hippocampus after unilateral lesions of the entorhinal cortex. Levels of GFAP mRNA were evaluated by dot blot hybridization of mRNA isolated from the hippocampus and quantitative in situ hybridization. For dot blot hybridization, RNA was isolate...

A repetitive DNA element was obtained from a crayfish genomic library while attempting to isolate the gene for the pigment concentrating hormone (PCH) with an oligonucleotide probe. The probe was directed to the coding region of the octapeptidic hormone deduced from the amino acid sequence of PCH (1). The isolated clone contained a 14 nucleotide sequence tandemly repeated 30 times; eleven nucle...

We isolated a Campylobacter-like organism resembling Helicobacter fennelliae from a 5 1/2-year-old boy with gastroenteritis. Similar strains had been found previously in fecal specimens from healthy and diarrheic dogs. These isolates could be differentiated from H. fennelliae by a lack of catalase and arylsulfatase activities. This group of organisms seems to be homogeneous by a nonradioactive ...

A chemiluminescence dot blot hybridization assay was used for the detection of B19 parvovirus DNA in human sera by using digoxigenin-labeled probes. The probes were revealed immunoenzymatically by use of anti-digoxigenin Fab fragments conjugated with alkaline phosphatase. The chemiluminescence signal was obtained by reacting the labeled probe-target complex with an enzyme-triggerable dioxetane ...

Streptococcus uberis is considered one of the most important pathogens associated with bovine mastitis. While traditionally acknowledged as an environmental pathogen, S. uberis has been shown to adopt a contagious epidemiological pattern in several dairy herds. Since different control strategies are employed depending on the mode of transmission, in-depth studies of S. uberis populations are es...