A colorimetric method for detection of K-ras codon 12 point mutations in DNA extracted from tissue and peripheral blood in pancreatic disorders.

Molecular-based methods to monitor point mutations require special and expensive equipment unavailable in most hospitals. Colorimetric-based analysis is an ideal platform for K-ras codon 12 gene point mutations because it uses commonly found hospital equipment. The colorimetric assay is sensitive and specific, detecting mutated DNA levels as low as 1% in a wild-type background.

Use of the paraffin wax baiting system for identification of Pseudomonas aeruginosa clinical isolates.

Pseudomonas aeruginosa is the primary pathogen among the Pseudomonads and is known for its minimal nutritional requirements, capacity to use paraffin as a sole carbon source, and biofilm formation. Because the ability of Pseudomonads to grow on paraffin is not commonly found among human pathogens and the primary Pseudomonas human pathogen is P. aeruginosa, we studied the adaptation of the paraffin baiting system for the growth and identification of clinical isolates of P.

A modified broth dilution assay for antibiotic sensitivity testing of Mycobacterium avium-intracellulare using paraffin slide cultures.

Mycobacterium avium-intracellulare (MAI) can utilize paraffin wax as the sole carbon source in basal media. Paraffin slide culture (Para SL/C) has been employed for isolation and speciation of MAI derived from clinical sources. We have evaluated an adaptation of this method for antimicrobial sensitivity testing.

The use of paraffin wax metabolism in the speciation of Mycobacterium avium-intracellulare.

Paraffin-wax utilisation or baiting of Mycobacterium avium-intracellulare (MAI) complex organisms and other 'atypical mycobacteria' and the inability of Mycobacterium tuberculosis to utilise paraffin are known and useful if forgotten facts. Strains of possible AIDS-related MAI have been introduced into Czapek broth devoid of any carbon source other than paraffin-wax coated slides. Replicate slides showing 'in situ' growth were subjected to the following battery of tests: acid alcohol fast staining and microscopic examination of 'in situ' growth, tellurite reduction in 3 days, absence of urea hydrolysis, inability to reduce nitrates and inability to hydrolyse Tween 80.

Enteroviral-related antigen in circulating immune complexes of amyotrophic lateral sclerosis patients.

Circulating immune complexes were isolated by polyethylene glycol precipitation from the sera of patients with amyotrophic lateral sclerosis. Rabbits immunized with circulating immune complexes from 3 of 5 amyotrophic lateral sclerosis patients induced antisera that specifically reacted with enterovirus-infected cells by immunofluorescence and enzyme-linked immunosorbent assay. These antisera were nonneutralizing and did not react with purified virus.

Studies on the Vibrio cholerae mucinase complex. III. Neutralisation of the neuraminidase activity by specific anti-neuraminidase IgG.

A partially-purified neuraminidase from the mucinase complex of Vibrio cholerae was used to prepare a specific anti-neuraminidase antiserum in rabbits. When the neutralising potency of this serum against V. cholerae neuraminidase was assessed in conventional tests, the enzymic activity, as measured by thiobarbituric acid, methoxyphenol-neuraminate and goblet-cell assays, apparently increased.

Studies on the Vibrio cholerae mucinase complex. II. Specific neuraminidase activity measured histochemically in a goblet cell assay.

The activity of neuraminidase prepared from the mucinase complex of Vibrio cholerae was measured by a new, semi-quantitative goblet-cell assay. The counts of normal, alcianophilic, sialomucin-containing goblet cells (purple-stained) and neutral mucosubstance-containing goblet cells (magenta-stained) in serial sections of ileum were compared before and after neuraminidase treatment. The procedure provides a more natural assessment of the action of V.

Studies on the Vibrio cholerae mucinase complex. I. Enzymic activities associated with the complex.

Mucinase enzymes were isolated and partially purified from the culture fluid of Vibrio cholerae grown in proteose peptone-colostrum medium. The mucinase complex contained neuraminidase, endo-beta-N-acetylhexosaminidase, nicotinamide-adenine-dinucleotidase and proteinases. Traces of phospholipase activity were detected but the complex lacked aldolase activity.

A paraffin baiting technique that enables a direct microscopic view of "in situ" morphology of Nocardia asteroides with the acid-fast or fluorescence staining procedures.

The paraffin slide culture technique has provided a means of greatly increasing the effectiveness of the paraffin baiting procedure in the identification of Nocardia asteroides. This has been accomplished with paraffin coated slides rather than the conventional paraffin coated rods, which allows for direct microscopic examination of the "in situ" growth because of its flat surface. This microscopic examination is further facilitated by staining with Kinyoun Acid-fast Stain, or combines three important elements necessary for the identification of Nocardia asteroides, namely; "in situ" morphology, acid-fastness and Auramine fluorescence.

The adaptation of fluorescence microscopy for Nocardia asteroides: a preliminary report.

The Fluorescence Microscope is extremely effective in revealing the presence and morphology of Nocardia asteroides. This has been effectively demonstrated when the Auramine Fluorochrome was decolourized with 1% H2SO4 and the interval of decolourization was limited to two minutes and thirty seconds. When Nocardia asteroids was seeded in sputum found to be negative for acid-fast organisms and in greatly diluted quantities after one hour intervals, its presence was still revealed with the Flourescence Microscope.