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Biomedical subjects

C McDonald

Publications and source records attributed to C McDonald.

At least 127 records · Page 7Linked to original sources

Serologic evaluation of cattle inoculated with Toxoplasma gondii: comparison of Sabin-Feldman dye test and other agglutination tests.

Six cows and 6 calves were each inoculated with 100 or 100,000 Toxoplasma gondii oocysts. Serum samples were analyzed, using the Sabin-Feldman dye test (DT), indirect hemagglutination test, latex agglutination test, and the modified direct agglutination test (MAT). Antibody titers in cows were lower than in calves. In the cows, DT titers increased briefly during the first month after inoculation, after which the titers were negative; however, T gondii was isolated from the tissues of 4 cows. Indirect hemagglutination and latex agglutination titers were generally less than 1:256. The MAT titers increased to 1:1,024 during the first month after inoculation. In 5 of the 6 cows, the MAT titers persisted. The 6th cow had a preinoculation MAT titer of 1:2,000 for 3 to 6 months. Therefore, the DT was not useful in serologic surveys for T gondii in cattle; the MAT was the most sensitive test and may be useful in the diagnosis of T gondii infection in cattle.

Age Factors↗

Serologic diagnosis of toxoplasmosis in experimentally infected pregnant goats and transplacentally infected kids.

Eight pregnant goats were inoculated orally with 10 to 1,000 oocysts of Toxoplasma gondii at 83 to 102 days of gestation. Serum samples from the goats and from the kids born to them were analyzed, using the Sabin-Feldman dye test (DT), a commercially available modified agglutination test (MAT), and a latex agglutination test. Six of the does were observed for greater than 1 year; during this time, they delivered twice. All does developed DT and MAT antibody titers of greater than or equal to 1:2,048 within 29 days after inoculation, and the high titers persisted through the 2nd pregnancy; therefore, serologic results alone should not be relied on for the diagnosis of T gondii-induced abortion in does. On the other hand, all transplacentally infected kids had DT or MAT antibody titers of 1:2,048 before ingesting colostrum, indicating the usefulness of serologic evaluation of the fetus or stillborn kid in the diagnosis of abortion. Antibody was not found in the sera of noninfected kids born to Toxoplasma-infected does. The passively acquired colostral antibody declined by 5 months. Therefore, specific antibody found in adult goats is probably actively acquired. The commercially available MAT was simple, sensitive, and reliable for the diagnosis of caprine toxoplasmosis. The latex agglutination test needs further improvement, as titers rarely exceeded 1:256.

Agglutination Tests↗

Cytodestructive mechanisms provoked by food antigens: III. Inhibition of direct and antibody-dependent allergic autocytotoxicity (ACT) by ketotifen.

In vitro challenge of peripheral white blood cells (WBC) from 15 food sensitive individuals and 16 asymptomatic controls was studied in allergic autocytotoxicity (ACT) assay using extracts of cow's milk, corn, and wheat. The observed disintegration of the WBC in the direct and antibody-dependent ACT was inhibited by ketotifen in a linear, dose-dependent manner. Therefore, our data demonstrate that the ACT response is associated with anaphylactic injury which is prevented by pretreatment with ketotifen, in vitro.

Adult↗

Electroconvulsive therapy: results in depressive illness from the Leicestershire trial.

Electroconvulsive therapy was investigated in a double blind trial. Altogether 186 clinically selected patients were referred to the trial, but 48 of these did not participate. According to the present state examination, 95 of the remaining 138 patients fell into one of the classes of major depression. Patients were randomly allocated to a course of real or simulated electroconvulsive therapy. Treatment was given twice a week with a maximum of eight treatments. On the Hamilton depressive rating scale the improvement in the group given real treatment was significantly greater than that in the group given simulated treatment both at two weeks (p = 0.014) and at four weeks (p = 0.0001). At follow up at 12 and 28 weeks there was no difference between the treatment groups. At the end of the four week trial consultants, who were blind to the allocation of treatment, rated the patients who had received real treatment as having made a significantly greater improvement than the patients who had received simulated treatment (p less than 0.00005). Further analysis showed that electroconvulsive therapy was effective in depression associated with delusions and in depression associated with retardation.

Clinical Trials as Topic↗

Isolation and characterisation of genomic and cDNA clones for an androgen-regulated secretory protein of rat seminal vesicles.

Testosterone controls the synthesis of seminal vesicle protein F in male rats by regulating the cellular concentration of its mRNA (mRNAF). Phage lambda recombinants have been isolated containing the complete F gene. In addition plasmids have been constructed containing cDNAF sequences some of which are probably full-length (approximately 700 bp). Detailed restriction mapping shows that the F gene is 1.7 kbp long and contains approximately 1.0 kbp of intervening sequence arranged in at least two introns (420 bp and 600 bp). Part of cDNAF has been sequenced showing that the terminal 125 bp of the 3' untranslated region of mRNAF has substantial (greater than 70%) sequence homology with the 3' end of the mRNA coding for another androgen-dependent seminal vesicle protein (protein S). The cloned F gene has been detected in liver and seminal vesicle DNA along with an homologous but structurally different gene. The hormonal control of mRNAF was examined with cDNAF. A pronounced (approximately 3000-fold) differential response to testosterone was observed.

Androgen-Binding Protein↗

Isolation and characterisation of genes for androgen-responsive secretory proteins of rat seminal vesicles.

Under the influence of testosterone, rat seminal vesicles synthesise large amounts of a tissue specific protein, S. Recombinant lambda clones have been isolated containing overlapping sequences covering a 27.5 kilo base region of the rat genome within which the gene for protein S is located. Recombinant plasmids bearing cDNA sequences for protein S were constructed in pBR328. One (pcS2) contains a 690 nucleotide insert and is probably full length. Detailed restriction maps of the S-gene are presented and the structure was confirmed by analysis of R-loops and heteroduplexes. The S-gene covers a 2 kbp region of the genome and consists of a 5' intron (490 bp) separating a leading exon (120 bp) containing the 5' untranslated region from a central exon (310 bp) containing most of the coding sequence and part of the 3' untranslated region. A larger intron (1100 bp) lies within the 3' untranslated region. The cloned gene is representative of the native gene but the S gene may be heterogeneous. Using pcS2, the hormonal control of S-specific mRNA was examined and a pronounced differential response to testosterone was observed.

Animals↗

Data base management, feedback control, and the Regenstrief Medical Record.

Because of the differences in informational needs among medical practices, medical record systems should be flexible. The use of data base management and use-oriented command languages helps to achieve flexibility. The Regenstrief Medical Record System is based upon a data base management system and two user-oriented command languages (the RDB Command Language and CARE). Most batch reports, file maintenance procedures, and ad hoc retrievals can be specified by the user by means of these two languages. This means that the user can specify which reports he wants and how they should look. Daily on-line activities are performed by application programs. The data base system also provides flexibility to these programs since the content and format of many of the display screens are defined by statements that are similar to the command language statements and are stored within a text file. The Regenstrief Medical Record System now carries records for 60,000 patients.

Appointments and Schedules↗

Topical and systemic antimicrobial agents in burns.

Infection is the major cause of morbidity and mortality in burns. Burn wound infection is defined as burn wound bacterial proliferation in a density equal to or greater than 10(5) bacteria per gram of tissue. Gram-negative bacteria, notably Pseudomonas aeruginosa, as well as staphylococci and fungal opportunists, have been identified as prominent invaders. Topical and systemic antimicrobial agents are essential adjuncts in the prevention and treatment of burn wound infection. Topical antimicrobial therapy is indicated in all hospitalized burn patients. Short-term use of systemic antimicrobials for prophylaxis and treatment is required in all moderate and major burns, specifically for early prophylaxis, perioperative prophylaxis, and clinical infection. Antimicrobial choice is based on specific patient or environmental bacteriological data.

Administration, Topical↗