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Biomedical subjects

M W Riggs

Publications and source records attributed to M W Riggs.

48 records · Page 3Linked to original sources
PubMed1990

Detection of Cryptosporidium parvum oocysts in bovine feces by monoclonal antibody capture enzyme-linked immunosorbent assay.

A monoclonal antibody enzyme-linked immunosorbent assay (ELISA) was developed to detect Cryptosporidium parvum oocysts in bovine feces. Fecal oocysts were concentrated by centrifugation through Formalin-ethyl acetate solution and captured with monoclonal antibody 18.280.2 reactive with C. parvum oocysts. Captured oocysts were detected with goat anti-oocyst serum, following the addition of a peroxidase conjugate of rabbit anti-goat immunoglobulin and O-phenylenediamine substrate. The assay was specific for Cryptosporidium sp. oocysts and did not detect oocysts of Eimeria auburnensis, Eimeria bovis, Eimeria ellipsoidalis, or Eimeria zuernii. Assay sensitivity allowed detection of 3 x 10(5) oocysts per ml of feces, compared with 1 x 10(6) oocysts per ml detected by examination of acid-fast-stained fecal smears and 1 x 10(3) oocysts per ml detected by indirect immunofluorescence. The capture ELISA was suitable for diagnostic analysis of bovine fecal samples and for assessment of oocyst shedding in experimentally infected calves. This assay may also prove useful for diagnostic assessment of humans in which cryptosporidiosis is suspected.

Animals↗
PubMed1990

Suspected ciliary dysfunction in Chinese Shar Pei pups with pneumonia.

Chronic pneumonia was investigated in a litter of young Chinese Shar Pei in which 4 of 6 dogs were affected. Serum immunoglobulin concentrations (IgA, IgG, IgM) determined by radial immunodiffusion varied over time, but were not consistently lower in affected dogs, compared with control dogs. Two dogs that died had hydrocephalus and lymphoid depletion, in addition to severe broncho-pneumonia. Evaluation of ciliary ultrastructure in 2 affected dogs revealed random orientation of adjacent respiratory tract or oviductal cilia and a greater number of microtubular disarrangements, compared with control dogs. In vivo tracheal mucociliary clearance of 99mtechnetium macroaggregated albumin was absent in 1 dog examined. The ciliary abnormalities were suspected to have resulted in an inefficient mucociliary transport system predisposing to the development of pneumonia. Further evaluation of 1 Chinese Shar Pei revealed lymphocyte mitogenesis results that were not consistently less than those of a control dog, normal total hemolytic complement values, and normal blood neutrophil chemotaxis.

Animals↗
PubMed1989

Neutralization-sensitive epitopes are exposed on the surface of infectious Cryptosporidium parvum sporozoites.

Cryptosporidiosis is a diarrheal disease of humans, calves, and other mammals caused by the coccidian parasite Cryptosporidium parvum. Immune bovine serum and two surface-reactive antisporozoite mAb with neutralizing activity were used to identify sporozoite surface Ag by radioimmunoprecipitation/SDS-PAGE and immunoblotting. When isolated sporozoites were incubated with mAb 18.44, 12 to 25 times the ID50 for mice was completely neutralized. This mAb binds diffusely to the sporozoite surface and recognizes a sporozoite surface Ag that eluted in the void volume of a Bio Gel A column with an exclusion limit of 500,000 daltons. The Ag recognized by mAb 18.44 was not radiolabeled with 125I or [35S] methionine, migrated with the dye front in SDS-PAGE, and was insensitive to proteinase K digestion, suggesting a non-protein composition. mAb 17.41 significantly neutralized 25 times the ID50 of sporozoites for mice. This mAb binds multifocally to the sporozoite surface and recognizes [35S] methionine-labeled sporozoite surface Ag of 28,000 m.w., 55,000 m.w., and 98,000 m.w. Immune bovine serum immunoprecipitated [35S] methionine- or 125I-labeled sporozoite Ag ranging from less than 14,300 m.w. to greater than 200,000 m.w., including surface Ag of 28,000 m.w. and 55,000 m.w. The results indicate that two different molecules capable of inducing neutralizing antibody are exposed on the surface of C. parvum sporozoites.

Animals↗
PubMed1989

Hyperimmune bovine colostrum neutralizes Cryptosporidium sporozoites and protects mice against oocyst challenge.

Activity of colostral whey, produced by a cow immunized with oocysts of Cryptosporidium parvum and found to provide prophylaxis against cryptosporidiosis in calves, was tested in 2 experiments. In one experiment BALB/c mice were given the immune whey (HW), whey from a nonimmunized cow (CW), or a balanced salt solution (HBSS) before, during, and after oral inoculation with oocysts of C. parvum. Significantly fewer (P less than 0.05) C. parvum were found in mice that received HW (undiluted, 1:20 or 1:50) than in those treated with similarly diluted CW or with HBSS. In the second experiment it was determined that protection was mediated by specific anti-sporozoite activity when significantly fewer (P less than 0.05) C. parvum were found in mice that received sporozoites treated with HW diluted 1:20 or 1:50 compared with mice that received sporozoites treated with similarly diluted CW or with HBSS.

Animals↗
PubMed1987

Evaluation of foals for immune deficiency disorders.

Currently recognized equine immune deficiency disorders include failure of passive colostral immunoglobulin transfer, combined immunodeficiency, selective IgM deficiency, transient hypogammaglobulinemia, and agammaglobulinemia. Additional equine immune deficiency disorders probably exist. Immune deficiency should be suspected in any horse experiencing persistent or recurrent infections that are not responsive to conventional therapy.

Animals↗
PubMed1987

Infectivity and neutralization of Cryptosporidium parvum sporozoites.

Cryptosporidiosis, a diarrheal disease of calves and humans caused by the coccidian parasite Cryptosporidium parvum, is terminated in hosts with normal immune systems. To assess the mechanisms of immunity in cryptosporidiosis, it is necessary to isolate and quantitate sporozoites, the infective stage of Cryptosporidium spp. Here we report the (i) separation of infective C. parvum oocysts from calf feces by ether extraction, sieving, and hypochlorite treatment; (ii) separation of viable C. parvum sporozoites from intact and excysted oocysts by anion-exchange chromatography; and (iii) quantitation of sporozoite infectivity in vivo by direct intraintestinal injection of isolated sporozoites in 7-day-old BALB/c mice. When isolated sporozoites were incubated with heat-inactivated immune bovine serum, 25 times the 50% infective dose for 7-day-old mice was completely neutralized. Sporozoites incubated with preimmune bovine serum were infectious for 7-day-old mice.

Animals↗
PubMedDate not supplied

Psychosocial and demographic factors related to health behaviors in the 1st trimester.

OBJECTIVE: To explore the relationship of psychosocial and demographic variables to health behaviors in early pregnancy. DESIGN: First trimester findings presented from a prospective study of weight gain in pregnancy. SETTING: A comprehensive health care system in central Texas. PARTICIPANTS: 114 pregnant women (75% white, 13% African American, 10% Hispanic, 2% Asian) of 12 weeks gestation or less. OUTCOME MEASURE: Self-Care Inventory, which includes diet/eating, substance abuse, recklessness, hygiene-related practices, sleep/rest, and exercise behaviors. RESULTS: In regression analysis the final model of demographic and psychosocial variables showed that higher depressive symptoms, lower internal locus of control for fetal health, and lower family income were related to poorer health behaviors in the 1st trimester of pregnancy. CONCLUSIONS: Health behaviors in early pregnancy may be affected by psychosocial factors such as depressive symptoms. Greater emphasis should be given to such factors in research and prenatal assessments.

Adolescent↗
PubMedDate not supplied

A prospective evaluation of risk factors for infections from dog-bite wounds.

OBJECTIVE: To define risk factors for infections from dog- bite wounds and to model the probability of wound infection in patients presenting without infection who are treated as outpatients. METHODS: A prospective survey of 769 consecutive dog-bite victims presenting over a two-year period to a community hospital emergency department (ED) with an emergency medicine residency program. A standardized wound-cleaning protocol was used, which included debridement and wound closure when indicated. Wounds were examined for infection at follow-up. Variables analyzed included demographic data (patient age, gender, race); wound information (wound age, type, number, location, depth); and treatment (prior to hospital, ED debridement, suturing, tetanus or rabies shots, antibiotics). RESULTS: There were 734 patients with complete records. These patients had a mean age of 13.4 +/- 13.2 years (range, 4 months to 71 years). Infection was evident in 2.5% of the wounds upon presentation. There were 704 patients (765 wounds) managed as outpatients and without wound infection upon presentation. Wounds were distributed as follows: 26.7% head/neck, 20.4% hand, 15.7% arm, 10.1% trunk, 9.5% thigh, 15.9% leg, and 1.7% foot. There were 32.9% puncture, 39.9% full-thickness, and 60.1% partial-thickness wounds. Wound infections were diagnosed in 2.1% Of these wounds at follow-up. Wounds requiring surgical debridement had a sevenfold higher infection rate (p = 0.01). Patients more than 50 years of age had a sixfold higher infection rate than younger patients (p = 0.05). Stepwise logistic regression found the following variables to be the best predictors for wound infection: full-thickness [p = 0.006, odds ratio (OR) = 6.23], female gender (p = 0.048, OR = 2.88), and wound debridement (p = 0.024, OR = 5.01). Combinations of these three variables predict infection rates from 0.35% to 23.9%. CONCLUSION: A low wound infection rate was seen in this cohort of dog-bite victims who were treated on an outpatient basis. Wound depth, patient gender, and wound debridement were the clinical variables that best predicted the likelihood of developing infection. Future interventional studies should concentrate on wounds with high probabilities of infection.

Adolescent↗
PubMedDate not supplied

Cranial teratomas in two domestic ducks (Anas platyrhynchos domesticus).

Teratomas are rare tumors in domestic fowl, and none have been reported in the cranial area of ducks. Clinical signs and gross and microscopic findings associated with a cranial teratoma in two domestic ducks are reported. One tumor arose within the cranial vault and was associated with neurologic signs. The other tumor was subcutaneous and invaded the parietal bone but did not extend into the brain. Both tumors were tridermic.

Animals↗