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Biomedical subjects

R D Griffith

Publications and source records attributed to R D Griffith.

9 recordsLinked to original sources

Estimation of the Salmonella enterica prevalence in finishing swine.

The study objective was to evaluate three methods of Salmonella enterica prevalence estimation in swine herds (faecal culture, culture of abattoir-collected samples, and serum ELISA). From each of six swine herds, we necropsied approximately 100 finishing pigs (> 70 kg); one-half on farm and the other half at the abattoir, after transport and approximately 2.5 h holding. We collected the same samples for S. enterica culture at both locations (1 g faecal, 10 g caecal contents, ileocaecal lymph nodes, superficial inguinal lymph nodes, 25 g of gluteal muscle for serum ELISA). On farm, the 1 g faecal sample only detected 13.3% (2/15) of all positive pigs necropsied on farm. However, with abattoir and on-farm results combined, the faecal sample detected 57.4% (74/129) of positive pigs. Abattoir-collected samples provided prevalence estimates much higher than on-farm collected samples (39.9 vs. 5.3%; P < 0.001). This study shows that faecal samples have a low sensitivity for detecting infected pigs and that abattoir-collected samples overestimate the on-farm S. enterica prevalence. For most herds, serology overestimated the on-farm culture prevalence.

Abattoirs↗

Recognition of pollen and other particulate aeroantigens by immunoblot microscopy.

Most grass-pollen types appear identical by normal light microscopy. Restricted antigenic cross-reactivity of Cynodon dactylon (Bermuda grass) pollen allowed development of a new method to identify antigens associated with grass-pollen grains. Pollen applied to the surface of an adhesive tape was blotted onto nitrocellulose, and the blots were identified by anti-Bermuda-grass antibodies, second antibody, and fluorescence microscopy. Of the 44 species of grass pollen studied for specificity of the method, the only species to demonstrate uniformly bright staining were Cynodon dactylon, Elymus triticoides, Elymus cinereus, and Koeleria cristata. Thirty-one species were negative, and nine other species demonstrated occasional brightly fluorescent spots, suggesting contamination. The immunoblotting method was used to study Tucson air collected continuously by a Burkard pollen and spore trap throughout April 1986. Each 2-hour transect of the adhesive tape from the trap was examined by immunoblotting and by normal light microscopy to compare antigen particle counts with grass-pollen counts. The mean antigen-particle concentration, 52.8/m3 of air, was higher than the mean grass-pollen concentration, 21.9/m3 of air, suggesting presence of amorphous Bermuda-grass antigens in air samples. Antigen-particle concentration, not grass-pollen concentration, correlated significantly with wind velocity, temperature, and time of day.

Air↗

Diaphragmatic pain in pulmonary endometriosis.

The diagnosis of pulmonary endometriosis is difficult and requires a high index of suspicion in patients with pelvic endometriosis. We have reported a case in which a history of periscapular pain associated with menses proved useful in delineating the cause of the hemothorax.

Adult↗

A specific defect in glycosylation of epidermal cell membranes. Definition in skin from patients with epidermolysis bullosa simplex.

Why blister formation occurs within the epidermis in epidermolysis bullosa (EB) simplex is not known. One possibility is that there are diminished amounts, absence, or biochemical alterations of one or more structural components of epidermal cell membranes, thereby leading to increased skin fragility. In order to test this hypothesis, biopsy specimens were obtained from clinically normal-appearing skin of patients with simplex, junctional, and dystrophic forms of EB and normal adult volunteers. Immunofluorescence studies were performed on each specimen using eight fluorescein-labeled affinity-purified lectins shown to bind uniformly to epidermal cell membranes of normal human adult skin and neonatal foreskin. To examine the epidermal cytoskeleton, each tissue specimen was also examined using two antikeratin monoclonal antibodies. Irregular and focally granular epidermal membrane staining was noted in each EB simplex specimen examined with the lectin-peanut agglutinin. In contrast, uniformly crisp membrane staining was seen in each specimen from patients with junctional or dystrophic EB and from normal volunteers. This epidermal cell membrane glycosylation defect appears to have the restricted carbohydrate specificity of peanut agglutinin since staining of EB simplex skin with each of the remaining seven lectins was indistinguishable from that seen in skin from patients with the other forms of EB and normal adult skin. Furthermore, the epidermis in EB simplex skin appears to be selectively abnormal since the same tissue specimens demonstrated normal keratin cytoskeleton staining.

Antibodies, Monoclonal↗

Retinal burns occurring at cataract extraction.

Paramacular changes presumably induced by operating microscope light have been described previously in six patients who had undergone extracapsular cataract extraction with posterior chamber lens implantation. Twelve additional patients are reported, including pseudophakes and nonpseudophakes, macular and paramacular burns, and no visual loss and severe visual loss. Burns occurred in spite of filters and light barriers used in some cases. Light sources were tungsten bulb or halogen/fiberoptic. Three cases had essentially normal preoperative angiography. Currently recommended safety measures have not eliminated this complication.

Aged↗

Primary retinal detachments without apparent breaks.

In a prospective study of 415 consecutive eyes operated on for retinal detachment, there were no apparent retinal breaks in 41 eyes. Examination of the most likely site for breaks during, or shortly after, cryotherapy was helpful in detecting tiny breaks in several cases. All detachments without apparent breaks were operated on with a three-step operation: we applied two rows of confluent cryotherapy to all retinal breaks, drained subretinal fluid, and used buckles just anterior to the equator. Surgical cure, defined as reattachment for at least six months, was achieved in 93% of eyes with apparent breaks, and in 85% of eyes without apparent breaks. The latter figure increased to 91% when the seven patients with preoperative massive preretinal retraction were excluded.

Choroid↗