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Biomedical subjects

I Campbell

Publications and source records attributed to I Campbell.

At least 145 records · Page 8Linked to original sources
PubMed1982

The use of paraffin-processed tissue and the immunoperoxidase technique in the diagnosis of bullous diseases, lupus erythematosus and vasculitis.

Twenty-two skin biopsies have been split and each half examined either by the immunoperoxidase technique on paraffin-fixed tissue or by both immunoperoxidase (IP) and immunofluorescence (IF) technique on snap-frozen tissue. All twenty-two specimens gave positive results by frozen IF techniques, nineteen out of twenty-two (86%) were positive by frozen IP techniques and sixteen out of twenty-two (72%) were positive by IP on paraffin-fixed material. If retrospective immunopathology is required on a specimen and only paraffin-fixed material is available a positive result may be expected in the majority of cases.

Dermatitis Herpetiformis↗
PubMed1982

Passive immunity in calf diarrhea: vaccination with K99 antigen of enterotoxigenic Escherichia coli and rotavirus.

Twenty-four pregnant cows were vaccinated intramuscularly with K99 extract from enterotoxigenic Escherichia coli and inactivated rotavirus as follows: six cows were injected with 2 ml of oil-adjuvanted vaccine; six cows were injected with 0.5 ml of oil-adjuvanted vaccine; six cows were injected with 4 ml of aluminum hydroxide-adjuvanted vaccine twice with a four-week interval; and six cows were unvaccinated as controls. Calves born to these cows were challenged with enterotoxigenic E. coli at 6 to 18 h after birth. Serum and milk antibodies to K99 and rotavirus in cows vaccinated with either dose of oil vaccine were significantly increased until at least 28 days after calving. In cows vaccinated with alhydrogel vaccine, there was a significant K99 antibody increase in serum and in colostrum but not in milk and a significant rotavirus antibody increase only in colostrum. Five of six calves born to unvaccinated cows developed enterotoxic colibacillosis after challenge, and all excreted the challenge strain of enterotoxigenic E. coli. None of the 18 calves in the three vaccinated groups developed clinical colibacillosis, and fecal excretion of the challenge organism was reduced. A combined enterotoxigenic E. coli-rotavirus vaccine may prove useful in preventing some outbreaks of calf diarrhea.

Animals↗
PubMed1982

Experimental infection of lambs with Cryptosporidium isolated from a human patient with diarrhoea.

An inoculum containing Cryptosporidium oocysts obtained from an adult human patient with acute transient diarrhoea induced enteritis in two newborn specific pathogen free lambs. Three days after inoculation the lambs became depressed and diarrhoeic, their milk intake was reduced and Cryptosporidium oocysts were detected in their faeces. Mucosal changes observed in the small intestine of one infected lamb were consistent with but less severe than those induced experimentally in lambs by cryptosporidia isolated from calves and lambs.

Animals↗
PubMed1981

IgG1 antibody in milk protects lambs against rotavirus diarrhoea.

Newborn gnotobiotic lambs were fed a diet of diluted evaporated milk supplemented either with normal ewes' milk or with milk obtained from ewes injected parenterally during gestation with rotavirus. Lambs fed 150 ml per day of milk collected 5 days after lambing from normal ewes were susceptible to rotavirus infection and diarrhoea, while lambs fed milk from vaccinated ewes collected either 5 or 12 days after lambing were protected. Analysis of the milk by column chromatography showed the anti-rotavirus activity to be in the fractions containing IgG1.

Animals↗
PubMed1981

Diarrhea in young red deer associated with infection with Cryptosporidium.

In an outbreak of diarrhea among 82 artificially reared red deer calves, 56 developed the disease and 20 subsequently died. During the outbreak 80% of diarrheal and 50% of apparently healthy calves excreted cryptosporidial oocysts in feces. The coincidence of infection with Crytosporidium and clinical diarrhea suggested a causal relationship. Histologic examination of intestinal sections from a necropsied deer calf showed lesions consistent with field and experimental cryptosporidiosis in other species. The deer Cryptosporidium subclinically infected newborn mice; in indirect immunofluorescence tests, it could not be distinguished from a calf Cryptosporidium.

Animals↗
PubMed1981

Diarrhea in lambs: experimental infections with enterotoxigenic Escherichia coli, rotavirus, and Cryptosporidium sp.

Thirteen gnotobiotic lambs, aged from a few hours to 8 days, were inoculated orally with single infections of enterotoxigenic Escherichia coli (ETEC) (four animals), lamb rotavirus (five animals), and Cryptosporidium (four animals). Six gnotobiotic and two specific-pathogen-free lambs were co-inoculated with either rotavirus and ETEC (four animals), rotavirus and Cryptosporidium (two animals), or ETEC and Cryptosporidium (two animals). Lambs 4 days of age and older became only subclinically infected with either rotavirus, ETEC (08:K87:K99 ST+), or both enteropathogens given simultaneously. Six-day-old lambs inoculated with Cryptosporidium became extremely depressed, anorectic, and had intermittent diarrhea. There was no difference in the clinical manifestations, level of disaccharidase activity in the small intestine, or extent of histological damage between lambs inoculated with Cryptosporidium alone or together with either of the other two agents. The results indicate that under the conditions of these experiments, lambs become clinically resistant to infection with ETEC, rotavirus, or both agents together, by 4 days after birth, whereas lambs 2 days old or younger were clinically susceptible to infection by these agents. In contrast, they remained clinically susceptible to infection with Cryptosporidium up to at least 6 days of age. Cryptosporidium infections were not aggravated by coinfection with either ETEC or rotavirus.

Animals↗
PubMed1981

Diarrhea due to Cryptosporidium infection in artificially reared lambs.

Severe diarrhea which lasted 7 to 12 days occurred in 40 of 48 artificially reared lambs within 5 to 12 days of birth, and 16 of them died. Of 16 diarrheic fecal samples examined, 10 contained Cryptosporidium oocysts and 1 contained rotavirus, but no other known enteropathogen was detected. Upon histological examination, cryptosporidia were found in the ilea of three affected lambs, and in one of them, villous atrophy and fusion, with epithelial cross-bridging between villi, were present in distal small intestine. Diarrhea was induced in two specific pathogen-free lambs by oral inoculation with fecal homogenate containing Cryptosporidium oocysts. Both the small and large intestines became infected with the organism, and associated lesions included stunting, fusion, and deformities of villi in the distal small intestine, with replacement of columnar enterocytes by immature cuboidal cells. Subclinical infections were induced in newborn specific pathogen-free mice and rats. Judged by these data, the lamb-derived Cryptosporidium sp. is similar to those recovered from calves, deer, and humans.

Animals↗
PubMed1981

An investigation of operating theatre staff exposed to humidifier fever antigens.

Sixty staff working in a hospital operating theatre, where a case of humidifier fever had been identified, were studied together with 49 subjects working in other parts of the hospital. They each had a blood test for serology, a skin test, and a chest radiograph and completed a questionnaire. The theatre staff also had pulmonary function tests. The theatre humidifier was found to contain several organisms including amoebae and antigens cross-reacting highly with those implicated in previous outbreaks of humidifier fever. Of the 60 exposed subjects, 25 had developed antibodies, nine had probable symptoms of humidifier fever, and six possible symptoms. There was a strong association between symptoms and antibodies (p = 6 x 10(-5) by Fisher's exact test). The development of antibodies was also related to duration of exposure in the theatre (p less than 0.01 by X2 test for trend) and inversely to smoking (p = 0.0073 by Fisher's exact test) but not to history of atopy. Because of the presence of antigens and because certain biocides added were ineffective in controlling antigenic build-up the humidifier was switched off. Eight months later specific IgG levels in the theatre staff sera, estimated by an enzyme-linked immunosorbent assay technique, had fallen on average by 25%. Inhalation challenge with humidifier water was performed in eight subjects. Four subjects reacted to the challenge, including both those with antibodies and previous symptoms.

Air Conditioning↗
PubMed1981

Diarrhea in lambs experimentally infected with Cryptosporidium isolated from calves.

Two to 5 days after oral inoculation with Cryptosporidium obtained from infected calves, 7 newborn specific-pathogen-free lambs became depressed and anorectic and developed diarrhea. Four moribund lambs were killed within 3 days after onset of illness, and the 3 other lambs died after protracted intermittent diarrhea and reduced milk intake, which lasted up to 14 days. The small and large intestines were heavily infected with Cryptosporidium, with the terminal portion of the ileum being the most severely affected. Histologic examination revealed villous atrophy, with considerable fusion and epithelial cross-bridging between villi. Lambs infected at 5 to 20 days of age had less severe clinical signs of disease, with intermittent diarrhea, reduced milk intake, and growth retardation. Lambs infected at 30 days of age became infected with the organism, but did not develop clinical signs of disease or growth retardation.

Animals↗
PubMed1981

Experimental infection of piglets with cryptosporidium.

Piglets from five litters were doses orally with cryptosporidium originally derived from diarrhoeic calves. The piglets were either nursed by the sow, artificially reared after sucking colostrum, or weaned on to creep feed. Colostrum-fed, artificially reared piglets obtained from two litters and exposed in the first week of life developed clinical signs of inappetence, vomiting and diarrhoea and shed oocysts in the faeces. Histologically the parasite was observed throughout the small and large intestine attached to epithelial cell surfaces and its presence was associated with extensive mucosal damage, particularly in the posterior small intestine, stunting and fusion of villi, immaturity of villous epithelial cells and oedema with increased cellularity of the lamina propria. Piglets from two other litters, both sucking and colostrum-fed artificially reared, exhibited similar but milder clinical signs. Histological lesions were less severe and cryptosporidium infection less extensive. When weaned piglets were exposed they remained clinically healthy although histologically there was evidence of cryptosporidium attachment in the small intestine and minor mucosal damage. There appears to be a good correlation between the extent of intestinal infection, the degree of mucosal damage and the severity of clinical disease induced by cryptosporidium in piglets.

Animals↗
PubMed1980

Passive immunity in calf rotavirus infections: maternal vaccination increases and prolongs immunoglobulin G1 antibody secretion in milk.

Ten heifers were inoculated on two occasions with an inactivated preparation of tissue culture-grown calf rotavirus, and a further ten heifers received a placebo vaccine. Serum anti-rotavirus antibody titers were significantly increased throughout pregnancy in the vaccinated group. After calving, the mean neutralizing antibody titer of colostral whey in control cows was 100, associated with immunoglobulins A and G1. No antibody was detected in the milk of these cows after the 4th day postpartum. The colostral whey from the vaccinated cows had a mean antibody titer of 20,452; 28 days after calving, the mean milk antibody titer was 320, associated mainly with immunoglobulin G1. Calves were challenged with a large oral inoculum of calf rotavirus at the 7th day of age. There was significant lengthening of the incubation and prepatent periods in calves born to vaccinated dams, but rotavirus-associated diarrhea of equal severity occurred in both groups. Evidence is presented which suggests that rotavirus antibody in milk can protect against a smaller challenge dose. Maternal immunization against rotavirus may be a practical proposition.

Animals↗
PubMed1978

Reduced neuromuscular transmission safety factor in multiple sclerosis.

Regional intravascular injections of d-tubocurarine (0.3 mg) were administered in the hands of 23 normal subjects and 19 patients with multiple sclerosis. The degree of neuromuscular block and rate of recovery were determined by measuring the amplitude of the first dorsal interosseus muscle action potential which was evoked periodically by trains of five stimuli (3 Hz each) to the ulnar nerve. In normal subjects, the first response to the train returned to its preinjection level after 20.0 +/- 8.5 minutes and the fifth response after 27.6 +/- 7.8 minutes. Multiple sclerosis patients showed a significantly delayed recovery of the first response (58 percent of patients) and of the fifth response (42 percent), suggesting a latent defect of neuromuscular transmission.

Adolescent↗