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Biomedical subjects

J K Collins

Publications and source records attributed to J K Collins.

At least 91 records · Page 5Linked to original sources
PubMed1995

Micrometastases in bone marrow of patients undergoing "curative" surgery for gastrointestinal cancer.

BACKGROUND & AIMS: Immunohistochemical detection of bone marrow micrometastases has been reported as a prognostic marker in colorectal cancer. The aims of this study were to evaluate the potential advantage of flow cytometry as an objective method of identifying and quantifying micrometastatic deposits within bone marrow and to determine the prevalence and quantity of micrometastases in patients undergoing surgery for gastrointestinal cancers. METHODS: Flow cytometry was first validated by a controlled "spike" experiment in which varying numbers of neoplastic epithelial cells were added to bone marrow, and cytometry was performed in a blinded fashion. Three neoplastic cell lines (colonic and esophageal) with varying degrees of expression of cytokeratin-18 were used. Epithelial cells were detected by dual staining with fluorescence-labeled, monoclonal anti-cytokeratin, and propidium iodide. RESULTS: Cytometry reproducibly detected the presence of > or = 10 neoplastic cells per 10(5) marrow cells. Micrometastases were found in 20%-30% of patients undergoing potentially curative resection of colorectal and gastroesophageal adenocarcinomas. There was a trend toward increasing positivity for marrow deposits with advanced Dukes' staging of colorectal cancer. CONCLUSIONS: Flow cytometric assessment of bone marrow is a reliable, objective, and quantitative method of detecting micrometastatic deposits found in a substantial subset of patients undergoing surgery for gastrointestinal adenocarcinomas.

Adenocarcinoma↗
PubMed1995

How effective is an integrated approach to low vision rehabilitation? Two year follow up results from south Devon.

AIMS: A survey was undertaken to assess the effectiveness of an integrated approach to the provision of low visual aids (LVAs) in south Devon over a 2 year follow up period. This integrated approach includes the assessment of patient needs by low vision therapists, followed by the provision of suitable LVAs, with particular emphasis on training in their use. METHODS: A total of 125 patients were selected at random from the 445 patients seen in the low vision clinic at Torbay Hospital in the year 1991. These patients were sent questionnaires relating to the service over a 2 year period. Questionnaires from 111 patients were analysed at 1 year and 75 questionnaires together with 46 clinical reassessments, after 2 years. RESULTS: Using a similar questionnaire to one used in a previous study in the UK from a unit where LVA training was not provided, not only was a higher rate of satisfaction found with the services provided, but also the LVAs dispensed were used more frequently. The majority of the LVAs provided were of the simple, inexpensive variety and wastage was very low. CONCLUSIONS: It was concluded that this integrated approach to low vision rehabilitation with emphasis on training in the use of less complex LVAs exceeds the performance of other types of service that rely on the dispensing of more complex LVAs.

Adult↗
PubMed1995

Comparison of two commercially available single radial immunodiffusion kits for quantitation of llama immunoglobulin G.

Immunoglobin G (IgG) quantitation was performed by a commercially available single radial immunodiffusion kit on 528 plasma samples obtained from llamas. Fifty samples encompassing the range of values obtained were selected for further evaluation. The IgG concentration of these samples was measured by a second commercially available single radial immunodiffusion kit and a sodium sulfite precipitation kit. gamma-Globulins also were measured. IgG values predicted by the single radial immunodiffusion kits were not in agreement. Failure to appreciate this lack of agreement could result in misinterpretation of a llama's IgG level derived from one kit when clinical guidelines established using the other kit are followed.

Animals↗
PubMed1995

Efficacy of a Propionibacterium acnes immunostimulant for treatment of chronic Staphylococcus aureus mastitis.

This study determined the efficacy of treatment of chronic Staphylococcus aureus IMI of lactating dairy cows with a biological response modifier consisting of a killed preparation of Propionibacterium acnes. Fifty-one lactating dairy cows with chronic S. aureus IMI on two commercial dairies were enrolled in a controlled, randomized field trial. Twenty-four cows received 1 ml of the immunostimulant twice weekly for 4 wk, and the remainder of the cows served as untreated controls. Quarter milk samples were collected for SCC from all cows at 3 and 6 wk after initiation of treatment and for culture at 6 wk after initiation of treatment. If samples were negative for S. aureus at 6 wk, cows were sampled again for culture 1 wk later for 2 successive d before being considered cured. For the cows treated with immunostimulant, 16.7% (36.7% of infected quarters) were cured of S. aureus IMI; for the untreated group, 11.1% of cows (32.2% of quarters) were cured. The difference was not statistically significant. Immunostimulant treatment had no effect on quarter SCC in infected quarters overall, but, in those quarters that were cured of S. aureus infection, quarter SCC of treated cows tended to be lower than SCC of control cows.

Adjuvants, Immunologic↗
PubMed1995

Comparison of methods for estimation of Toxoplasma gondii-specific antibody production in the aqueous humor of cats.

Intraocular production of Toxoplasma gondii-specific antibody in cats has been estimated by comparing the ratio of T gondii-specific antibody in aqueous humor and serum with the ratio of total immunoglobulins in serum and aqueous humor (Goldmann-Witmer coefficient; aqueous antibody coefficient; C value). It has been proposed that in human beings, comparison of the ratio of T gondii-specific antibody in aqueous humor and serum with the ratio of antibodies against a nonocular pathogen in serum and aqueous humor is more accurate than methods using total immunoglobulin quantification. We developed an ELISA for detection of calicivirus-specific antibodies in the serum and aqueous humor of cats. By evaluating calicivirus-specific antibody concentrations in the aqueous humor of healthy and diseased cats, calicivirus was assessed as a nonintraocular pathogen. The ratio of T gondii-specific antibodies in the aqueous humor and serum and the ratio of calicivirus-specific antibodies in serum and aqueous humor were evaluated as a means of estimating intraocular T gondii-specific antibody production. A field strain of feline calicivirus was isolated, cultured, and purified. A calicivirus-specific IgG ELISA was developed for detection of feline calicivirus-specific IgG in serum and aqueous humor. Calicivirus-specific IgG was measured in the serum and aqueous humor from 3 groups of control cats. Results suggested that calicivirus is a nonintraocular pathogen in cats and that calicivirus IgG detected in aqueous humor is attributable to leakage across a damaged blood-ocular barrier.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Epitope-specific antibody responses in market-stressed calves to bovine herpesvirus type 1.

Reciprocal competition ELISA (rcELISA) was conducted to map monoclonal antibodies (mAbs) reactive with gI, gIII and gIV glycoproteins of bovine herpesvirus type 1 (BHV-1) into epitope groups. mAbs to glycoproteins gI and gIV were divided into six epitope groups each, while gIII mAbs had been previously divided into four areas. mAbs were chosen from each epitope group to compete in cELISA wih bovine sera collected during a typical regimen of vaccination and transportation from farm to auction to feedlot. The immunodominant epitopes were identified for each BHV-1 glycoprotein. With glycoprotein gI, three epitopes defined by mAbs 1F10, D9 and 4807 were the most dominant; with glycoprotein gIII epitopes defined by mAbs G2 and 1507, and with glycoprotein gIV epitopes defined by mAbs 1102, 1106, 3C1, 3402 and 3E7 showed the maximum responses. The overall cELISA responses to each glycoprotein among two vaccination groups were also compared and it was shown that cELISA responses were significantly higher for each glycoprotein in calves receiving two vaccinations, one on the farm of origin and one at auction, than in calves receiving only one vaccination at auction.

Animals↗
PubMed1994

Monoclonal antibodies that distinguish between encephalitogenic bovine herpesvirus type 1.3 and respiratory bovine herpesvirus type 1.1.

Seven mouse hybridoma cell lines producing monoclonal antibodies (MAb) against an encephalitogenic strain of bovine herpesvirus type 1.3 (BHV-1.3) were established. The clones producing MAb were selected to be specific for BHV-1.3 by enzyme-linked immunosorbent assay. Only L1B neutralized virus without complement. With the addition of complement, five of the MAb neutralized BHV-1.3 but not the respiratory strain BHV-1.1. The anti-BHV-1.3-specific MAb Q10B, L6G, and L1B precipitated glycoproteins from BHV-1.3 that were analogous to the gI, GIII, and gIV glycoproteins of BHV-1.1, respectively. The other four MAb precipitated unknown proteins. None of the anti-BHV-1.3 MAb precipitated BHV-1.1 glycoproteins. The majority of the anti-BHV-1.3 MAb did not react with BHV-1.1 by immunoblotting, but O7E (unknown protein pattern by radioimmunoprecipitation) was reactive with five proteins (M(r)s of 33,000, 43,000, 70,000, 141,000, and 190,000) of BHV-1.3 and with a different pattern of proteins of BHV-1.1 (M(r)s of 30,000, 38,000, 83,000 and 144,000). Two of the MAb, L6G and O7E, conjugated with peroxidase were found to be useful for detecting BHV-1.3 antigen by immunochemistry in Formalin-fixed brain tissue from experimentally infected calves.

Animals↗
PubMed1994

Experimental infection of neonatal calves with neurovirulent bovine herpesvirus type 1.3.

A type of bovine herpesvirus, BHV-1.3, causes encephalitis in calves, whereas BHV-1.1 causes respiratory disease. Three colostrum-deprived calves and two colostrum-fed calves were inoculated with BHV-1.3 by intranasal aerosolization. Two colostrum-deprived calves were inoculated with BHV-1.1 by intranasal aerosolization. BHV-1.3-inoculated calves demonstrated severe encephalitis with minimal respiratory lesions, and BHV-1.1-inoculated calves demonstrated severe respiratory lesions and no clinical signs of neurologic disease. Calves fed colostrum that contained virus neutralizing antibodies were protected against neurologic disease. Colostrum-fed BHV-1.3-inoculated calves did not develop disease although they did become infected; virus was shed in respiratory secretions for 10-13 days postinoculation, similar to infected colostrum-deprived calves. BHV-1.3 was reactivated from a latent state from one colostrum-fed calf after administration of dexamethasone 60 days postinoculation. Histopathologic examination of the three colostrum-deprived BHV-1.3-inoculated calves revealed severe lesions of encephalitis. One of the two BHV-1.1-inoculated calves had one focal lesion of encephalitis. Virus was isolated from brain tissue of colostrum-deprived BHV-1.3-inoculated calves and from one BHV-1.1-inoculated calf. Immunohistochemical staining for BHV-1 antigen was observed in neurons from the colostrum-deprived BHV-1.3-inoculated calves.

Animals↗
PubMed1993

An immune suppressive factor derived from esophageal squamous carcinoma induces apoptosis in normal and transformed cells of lymphoid lineage.

An immunosuppressive factor produced by an esophageal squamous carcinoma cell line mediates profound irreversible suppression of in vitro proliferative responses of lymphoid cells. Exposure of activated normal PBL to the immune suppressive factor (ISF) resulted in the induction of an irreversible anergic state with apoptosis evident in 20% of those cells. Flow cytometric cell cycle analysis of mitogenically stimulated normal lymphocytes exposed to the ISF revealed that despite exhibiting full activation status (IL-2 production, IL-2R, and transferrin receptor expression) PBL were arrested at the G1/S interphase of the cell cycle. Transformed lymphoid cell lines, NSO and JURKAT, displayed morphologies characteristic of apoptosis within 24 h of exposure to the ISF. Flow cytometric cell cycle analysis of the JURKAT cells incubated with ISF revealed that > 90% of these cells had undergone apoptosis within 24 h. Agarose gel electrophoresis of DNA extracted from the ISF-treated lymphoid cells resolved a DNA fragmentation pattern characteristic of apoptosis in both the NSO cells and to a lesser extent in the activated PBL exposed to the ISF but not in control cells. In JURKAT cells stimulated with anti-CD3 antibodies, Ca2+ mobilization was markedly enhanced in those cells exposed to ISF. Also, ISF independently induced a calcium flux in JURKAT cells. Induction of programmed cell death by ISF may account for the in vivo immune suppression local to the tumor site in squamous carcinoma of the esophagus.

Aged↗
PubMed1993

Antigenic differences between the major glycoproteins of bovine herpesvirus type 1.1 and bovine encephalitis herpesvirus type 1.3.

Differences in the antigenic structure of the major glycoproteins, gI, gIII and gIV, of bovine herpesvirus type 1.1 (BHV1.1) and the neurovirulent BHV1.3 were demonstrated with a panel of monoclonal antibodies (MAbs) prepared against the BHV1.1 glycoproteins. Glycoprotein gIII of BHV1.3 was the most dissimilar, reacting with only four of 15 gIII-specific MAbs. Glycoproteins gI and gIV of BHV1.3 reacted with eight of 11 and eight of 12 specific MAbs, respectively. Monospecific bovine antisera to the two viruses supported findings from the MAb analysis in that gI and gIV glycoproteins were cross-recognized, but gIII was not. Virus-neutralizing MAbs reactive to each glycoprotein and which reacted with both viruses also neutralized both viruses. Previously undescribed glycoproteins which were antigenically related to the intact gIII glycoproteins, but of reduced sizes and lacking at least one gIII epitope, were found for both viruses. Tunicamycin inhibition experiments and immunoprecipitation data suggested that these proteins were intracellular degradation products. Comparisons of the peptide footprints of the glycoproteins from the two viruses using protease V8 digestion after immunoprecipitation with cross-reactive MAbs revealed distinctive footprint patterns for the respective glycoproteins.

Animals↗
PubMed1993

Future challenges for behavioural research in adolescent health.

Risk to health during adolescence is more likely due to behaviour than disease. Problems arise because behaviour is distally removed from its consequences and negative reinforcement is not contiguous with it. The paper reviews recent research and the problems faced by health workers in devising educational programmes when behaviour, in the cultural value system of adolescents, is present-oriented and outcomes are future-oriented. The challenge to the behavioural scientist is to develop health education programmes which have personal meaning to adolescents. Working against this aim are such processes as adolescent taboos, locus of control, the personal fable, risk behaviours and social-cognitive immaturity. Suggestions are made for research scientists to devise and evaluate programmes to change the operational liberalism of adolescent behaviour by installing more ideologically conservative attitudes in the hope that behavioural change will follow.

Adolescent↗
PubMed1993

Use of an immunoperoxidase technique to detect equine herpesvirus-1 antigen in formalin-fixed paraffin-embedded equine fetal tissues.

An indirect immunoperoxidase (IP) procedure using the avidin-biotin-peroxidase complex detection technique was developed to detect viral equine herpesvirus-1 (EHV-1) antigen in formalin-fixed paraffin-embedded tissues from aborted equine fetuses. The procedure was applied to liver, lung, and other tissues from 20 cases of confirmed or suspected EHV-1-induced abortions. Specific staining was observed in tissue sections from EHV-1-infected fetuses. Positive IP staining was present in tissues of 7 cases that were also positive by fluorescent antibody (FA) and virus isolation (VI) and that had typical histologic lesions. There was no IP staining in 7 cases that had no histologic lesions and negative FA and VI results. Five cases had typical histologic lesions and positive results in only 1 laboratory test; 3 were positive by VI and 2 by FA. Liver of 1 case was positive by IP, but tissues were too autolytic for other tests to be evaluated.

Abortion, Veterinary↗
PubMed1992

Serologic prevalence of selected infectious diseases in cats with uveitis.

Serologic evidence of infection by Toxoplasma gondii, feline leukemia virus, feline coronaviruses, or feline immunodeficiency virus (FIV) is commonly found in cats with uveitis. Serum samples from 124 cats with uveitis were assayed by use of ELISA for the detection of T gondii-specific immunoglobulin M (IgM), IgG, and circulating antigens (Ag), as well as an ELISA for feline leukemia virus Ag, an ELISA for antibodies to FIV, and an indirect fluorescent antibody assay for antibodies to feline coronaviruses. Serologic evidence of infection by 1 or more of the infectious agents was detected in 83.1% of the samples. Serologic evidence of T gondii infection, defined as the detection of T gondii-specific IgM, IgG, or Ag in serum, was found in 74.2% of the samples. The seroprevalence of T gondii infection was significantly greater in cats with uveitis than in healthy cats from a similar geographic area. Serum samples from cats with serologic evidence of both T gondii and FIV infections were more likely to contain T gondii-specific IgM without IgG than samples from cats with serologic evidence of T gondii infection alone. Cats with serologic evidence of FIV and T gondii coinfection had a higher T gondii-specific IgM titer geometric mean and a lower T gondii-specific IgG titer geometric mean than did cats with serologic evidence of T gondii infection alone. Serologic evaluation for T gondii infection should include assays that detect IgM, IgG, and Ag, particularly in cats coinfected with FIV.

Animals↗
PubMed1992

Abomasal erosions in feedlot cattle.

The abomasa of 1,949 slaughtered feedlot cattle, 45 necropsied feedlot cattle that died 2 to 45 days after arrival, and 45 necropsied pastured cattle were opened and examined. Of these organs, 484, 1, and none, respectively, contained erosions. The slaughtered cattle were fattened at 3 locations: 1,305 with 430 eroded abomasa were fed a ration of corn in northeastern Colorado; 144 cattle with 4 affected abomasa fed a ration of milo in south-central Arizona; and 500 cattle with 50 affected abomasa fed a ration of milo and corn in northwestern Texas. The red-brown lesions developed late during the second semester of fattening and were located mostly on fundic folds. Those on fold edges were linear and were 2 to 15 cm long, whereas those on fold sides were punctate and were 2 to 15 mm in diameter. Normal fold edges contained fewer goblet cells and less surface mucus than did fold sides. Eroded folds had disruption of surface epithelium, damage to endothelial cells, and dilated, thrombosed, congested, and ruptured capillaries. Mean pH values of 16 normal and 17 eroded abomasa were 4.7 and 3.9, respectively. Necrosis of all tissue toward the mucosal surface of erosions was extensive. The cause of gastric erosion in cattle is not known.

Abattoirs↗
PubMed1991

The neurology of endemic cretinism. A study of two endemias.

Endemic cretinism is the most severe manifestation of dietary iodine deficiency. Two forms of the syndrome are traditionally described: neurological and myxoedematous. Although this classification highlights the important neurological sequelae of the disorder it implies that myxoedematous cretins have an alternative mechanism. Further, the nature of the neurological deficit associated with both types of endemic cretinism has received scant attention in recent times considering that it remains a common disorder in many parts of the world. The nature and extent of the neurological deficit found in endemic cretinism was investigated in 104 cretins from a predominantly myxoedematous endemia in western China and in 35 cretins from central Java, Indonesia, a predominantly neurological endemia. We found a similar pattern of neurological involvement in nearly all cretins from both endemias, regardless of type (myxoedematous or neurological), and of current thyroid function. Hallmarks of the neurological features included mental retardation, pyramidal signs in a proximal distribution and extrapyramidal signs. Many patients exhibited a characteristic gait. This probably reflected pyramidal and extrapyramidal dysfunction, although joint laxity and deformity were important contributing factors. Other frequently encountered clinical features were squint, deafness, and primitive reflexes. Cerebral computerized tomography (CT) revealed basal ganglia calcification in 15 of 50 subjects. The presence of basal ganglia calcification was confined to cretins with severe hypothyroidism. Otherwise, cerebral CT scanning demonstrated only minor abnormalities which did not contribute to the localization of the clinical deficits. We conclude that the same neurological disorder is present in both types of endemic cretinism reflecting a diffuse insult to the developing fetal nervous system. These clinical findings support the concept of maternal and fetal hypothyroxinaemia, arising from severe iodine deficiency, as the primary pathophysiological event in endemic cretinism. Differences between the two types of cretinism may be explained by continuing postnatal thyroid hormone deficiency in the myxoedematous type, which results in impaired growth, skeletal retardation and sexual immaturity.

Adult↗
PubMed1991

Detection of cattle infected with bovine viral diarrhea virus using nucleic acid hybridization.

A ribonucleic acid (RNA) hybridization assay to identify cattle infected by bovine viral diarrhea virus (BVDV) is described. The RNA probe was derived from the coding region at the 3' end of the genome of the NADL strain of BVDV. Total RNA from infected cell cultures or peripheral blood leukocytes from suspect animals was extracted and applied to nylon membranes with a slot blot apparatus. Peripheral blood leukocytes were tested concurrently for BVDV by virus isolation. The results of hybridization and virus isolation were in agreement for 92% of the cases. When compared with virus isolation, hybridization had a sensitivity of detection of 59.5% and a specificity of 95%. Cross-reactivity to RNA extracts of border disease virus-infected cells was noted. No cross-reactivity was detected to other common bovine viruses (bovine herpesvirus-1, bovine respiratory syncytial virus, parainfluenza-3 virus, and bluetongue virus), to viruses classified in related families (equine arteritis virus and Venezuelan equine encephalitis virus), or to viruses having similar genomic organization (dengue virus type 2 and Japanese encephalitis virus).

Animals↗