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Biomedical subjects

A Martin

Publications and source records attributed to A Martin.

1,069 records · Page 60Linked to original sources
PubMedDate not supplied

Mitogen-induced lymphocyte proliferation and interferon production following coccidia infection.

Concanavalin A-induced lymphocyte proliferation and interferon production were measured following infection with Eimeria acervulina in lines of chickens congenic at the major histocompatibility complex and in two unrelated lines. Similar proliferation responses were seen for splenic and peripheral blood lymphocytes following primary but not secondary infection. Greater differences in lymphocyte proliferation were found between the congenic lines and unrelated lines than among the congenic lines. The congenic lines had very low responses to Con A, in terms of both lymphocyte proliferation and interferon production. At some times after infection, background proliferation in all lines was higher for infected than uninfected chickens, which was probably an indication of activated lymphocytes in the circulation. Mitogen-induced lymphocyte proliferation and interferon production, although clearly affected by coccidial infection, were not reflective of severity of infection.

Animals↗
PubMedDate not supplied

Rapid determination of Listeria monocytogenes in foods using a resuscitation/selection/kit system detection.

A resuscitation medium consisting of a trypticase soy broth base supplemented with 0.5% yeast extract, 0.25% sodium pyruvate, 0.01% sodium thioglycollate, and 0.1% chicken fat was used in the resuscitation of heat-injured and freeze-injured cells of Listeria monocytogenes. After a resuscitation period of 4-h, the medium was made selective through the addition of nalidixic acid, acriflavin, and cycloheximide. The organisms were incubated in the selectivized medium at 35 degrees C for an additional 16 h. The numbers of resuscitated Listeria monocytogenes cells rose from 10(1) to 10(7) cells/mL in 20 h. Similar numbers of Staphylococcus aureus, Escherichia coli, and Salmonella bonn were grown together with Listeria monocytogenes; these organisms did not inhibit the growth of Listeria monocytogenes nor interfere with its detection by the Listeria-Tek kit system. The resuscitation/selection/kit system (RSK) was compared with the methodology in the Bacteriological Analytical Manual (BAM) for the detection of Listeria monocytogenes in 22 naturally contaminated cheese samples: 8 of these were positive by the BAM system and 12 were positive by the RSK system. The 8 Listeria positives found by the BAM system were positive by the RSK system. All 12 Listeria-presumptive positive samples by the RSK system were confirmed to be Listeria monocytogenes. The use of the RSK system enhanced the recovery of the pathogen, and detection was accomplished within 24 h.

Animals↗
PubMedDate not supplied

Characterization of cell-mediated responses to Eimeria acervulina antigens.

In order to identify antigens from Eimeria acervulina eliciting cell-mediated as well as humoral immune responses, merozoite and sporozoite fractions were separated by electrophoresis and injected into chickens. Coccidia-specific antibody titers, lymphocyte proliferation, and interferon production were measured to determine whether the inoculations sensitized the chickens to merozoites and sporozoites. Several fractions from merozoites and sporozoites induced humoral or cell-mediated responses. Merozoite fraction 4 (molecular weight [MW] 12,700-18,400) had the most consistent high interferon production; it also had good antibody production after challenge but not before challenge. Merozoite fraction 3 (MW 18,400-29,000) elicited high antibody titers and modest proliferation. Merozoite fraction 2 (MW 29,000-43,000) elicited consistently high proliferation; however, antibody responses were normal and interferon production was lower than that in the control. Merozoite fraction 5 (MW 6000-12,700) results were modest for all three parameters. Sporozoite fractions 5 and 6 (MW 12,700-29,000) elicited good antibody titers after challenge. The only sporozoite fraction that showed any interferon induction, fraction 2 (MW 69,000-200,000), also elicited good proliferation, although it did not stimulate antibody production. Sporozoite fraction 1 (> 200,000 MW) had very high proliferation potential. These findings support the hypothesis that different antigens preferentially elicited different T-cell responses.

Animals↗
PubMedDate not supplied

Quality of life in inflammatory bowel disease.

The usual indices of activity of Inflammatory Bowel Disease fail to evaluate an important aspect of patients' status, their Quality of Life (QOL). A questionnaire dealing with four important aspects of QOL (intestinal and systemic symptoms, emotional and social function) was developed and validated. The questionnaire was administered to 72 healthy controls, 57 patients with Ulcerative Colitis and 55 with Crohn's Disease with different disease severity. Compared to controls, QOL was impaired not only in the more severe forms of disease, but also in patients in remission. In Crohn's Disease, QOL was not closely correlated with the clinical features, thus indicating that the impairment of QOL cannot be inferred from the clinical status and that patients do not "adapt" with the passing of time. The questionnaire allows a more comprehensive definition of the patients' state of health, identifying features which might be underestimated as they fail to emerge from the routine clinical evaluation. A tool of this kind could be used alongside the activity index of disease, both in clinical studies and during routine follow-up.

Adaptation, Psychological↗
PubMedDate not supplied

Evaluation of the efficacy of Eimeria maxima oocyst immunization with different strains of day-old broiler and roaster chickens.

The performances of three different strains of male and female broiler or roaster chickens immunized at 1 day of age with a drug-resistant field isolate of Eimeria maxima were evaluated in battery and floorpen immunization trials. No difference in immunization potential was seen between these strains or sexes of day-old chickens immunized with 2500 oocysts/bird of E. maxima and challenged at 10 days of age with 25,000 oocysts/bird of the same isolate in two separate battery trials. All immunized birds showed significant protection for the parameters of weight gain and midintestinal lesion scores at 7 days post challenge (PC) when compared with nonimmunized challenged controls. In two separate floorpen trials, one broiler bird strain (designated strain 2) immunized by the same procedure and challenged at 21 days of age with the equivalent of 25,000 oocysts/bird of the same isolate showed significant protection for weight gain and lesion scores at 7 days PC when compared with nonimmunized controls. Birds in these same floorpen experiments immunized with E. maxima and then fed three different anticoccidial shuttle diets (narasin and nicarbazin 90 grams/ton (g/t) in starter feed and narasin 72 g/t + roxarsone 45.4 g/t in grower feed; nicarbazin 113 g/t in starter feed and narasin 72 g/t + roxarsone 45.4 g/t in grower feed; and monensin 100 g/t in starter and grower feed) showed no interference with elicited immunity with E. maxima challenge for the same parameters measured. No significant difference was seen between any floorpen immunized bird groups for total weight gain at trial terminations (49 days of age).

Animal Feed↗