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Biomedical subjects

C Finlay

Publications and source records attributed to C Finlay.

18 recordsLinked to original sources
PubMed2001

Absorption of dimethylacetamide (DMAC) following application of a polymer film to the skin of rabbits.

Kapton Film is a polymer with high strength and thermal resistance finding use in a wide variety of applications. In the preparation of this film, the uncured material could contain up to 30% dimethylacetamide (DMAC). Note that the final product Kapton Film has been thermally cured with the DMAC removed. During processing, dermal contact with the film is anticipated, and the possibility exists of DMAC transfer from the uncured film, to and through the skin. In this study, 2 x 2-inch pieces of film were applied to the skin of a group of rabbits and secured in place for a single 4-hour contact time. An amount of liquid DMAC corresponding to the amount contained in the 2-inch square was applied to the skin of a separate group of rabbits for 4 hours. Urine samples were collected over the intervals of application to 4 hours post application (8 hours total) or 4 to 20 hours post application (16 hours). The amount of the urinary metabolite monomethylacetamide (MMAC) was determined analytically in these samples. Urine from 2 untreated rabbits was collected at the same time to serve as controls. The amount of urinary MMAC found in the rabbit rine from animals exposed to uncured Kapton Film at both ollection intervals was similar to the amount seen in the controls (background). Rabbits treated with DMAC liquid had measurable urinary MMAC levels that were approximately 100 times background. It is concluded that, under the conditions of this study, very little, if any, DMAC from the uncured Kapton Film was absorbed through the skin (and excreted in the urine as MMAC).

Acetamides↗
PubMed2000

Anxiogenic effects of repeated administrations of 20% CO2-enriched air: stability within sessions and habituation across time.

Increasingly carbon dioxide-enriched air is being used as an aversive unconditioned stimulus in laboratory examinations of anxiety. Yet, little is known about the stability of the autonomic and subjective effects of this stimulus across repeated inhalations and sessions. We examined whether repeated administrations of high concentrations of CO2-enriched air produced either habituation, stability, or sensitization across several autonomic and self-report indices within one session (Experiment 1) and then several sessions (Experiment 2) of exposure. Results suggest that non-clinical participants do not habituate to CO2 within sessions, but do show habituation on cardiac and subjective report of anxiety across sessions. Individual difference factors such as anxiety sensitivity and suffocation fear seem to moderate some of these effects, including self-reported distress and anxiety in response to the challenge. These results support the use of CO2 as a panicogenic aversive stimulus in laboratory models of fear onset and in clinical settings for interoceptive exposure treatments of panic.

Adolescent↗
PubMed1997

[Solid-phase immunoenzyme ass for detecting Giardia lamblia antigens].

An ELISA sandwich for the detection of Giardia lamblia antigens in human faeces was standardized. 175 samples were studied: 77 positive, 61 negative to cysts and/or trophozoites by direct faeces test, and 19 positive to other parasite different from G. lamblia. The sensitivity of the technique was 94.8% and the specificity 98.3%. The method detects an antigen concentration of 31 ng. The procedure is simple, sensitive and specific so, it may be useful for diagnosis and in epidemiological studies.

Animals↗
PubMed1995

[The action of an aqueous extract of Aloe barbadensis Miller in an in-vitro culture of Trichomonas vaginalis].

The antiparasitic action of an aqueous extract of Aloe barbadensis Miller against and in vitro culture of Trichomonas vaginalis was studied for the first time. Three strains of this parasite were used for the study. Taking an initial concentration of 400 mg/mL of the extract, double serial dilutions were performed, and final concentrations based on the dried weight of the extract were 10.4, 20.8, 41, 83, and 160 mg/mL. Within 24 hours, percentages of inhibition greater than 50% were obtained from concentrations of 20.8 micrograms/mL. Similar results were obtained at 48, and 72 hours, with a lower concentration, the inhibition of growth was greater than 50%.

Aloe↗
PubMed1994

Evaluation of the immune response in symptomatic and asymptomatic human giardiasis.

To better understand the common association of Giardia lamblia infection and allergic reactivity, total and specific IgE values were evaluated and different manifestations of symptomatic and asymptomatic infected human hosts were analyzed. The humoral, cellular, and nonspecific immune responses were evaluated in Cuban adults. Increased total serum IgE levels were significantly higher (p < 0.01) in Giardia patients than in negative controls; cure of giardiasis was characterized by a decrease in IgE levels and some patients regained normal IgE values. The skin test was positive in 91% (103/123) of chronic patients and only in 23% (20/123) of negative controls (p < 0.05). A positive test was seen in patients with antecedents of recent giardiasis (< 4 months). Specific IgE was higher in patients than in control sera, and in the former it decreased with sera dilution. During the follow-up period of cured patients, the proportion of IgE decreased and the opposite occurred in noncured patients. The cellular response evaluated by LIF was positive in 92% (11/12) of carriers and significantly higher (p < 0.05) than in symptomatic patients 8% (1/12); the same occurred with IgG and IgA antibody response; titers mainly of IgA were higher in asymptomatic carriers than in patients; all carriers were negative to the skin test. These results indicate the presence of total and specific IgE responses in humans infected with Giardia, but the response in symptomatic cases (patients) is different from that in asymptomatic cases (carriers).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Gain of function mutations in p53.

We report that the expression of murine or human mutant p53 proteins in cells with no endogenous p53 proteins confers new or additional phenotypes upon these cells. Mutant p53 proteins expressed in cell lines lacking p53 resulted in either enhanced tumorigenic potential in nude mice ((10)3 cells) or enhanced plating efficiency in agar cell culture (human SAOS-2 cells). Also, mutant human p53 alleles, unlike the wild-type p53 protein, could also enhance the expression of a test gene regulated by the multi-drug resistance enhancer-promoter element. These data demonstrate a gain of function associated with p53 mutations in addition to the loss of function shown previously to be associated with mutations in this tumour suppressor gene.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1992

[A comparison of 3 single-dose plans for mebendazole in the treatment of trichuriasis].

People infected by Trichuris trichiura were selected in a community by the Kato-Katz technique. The study included a universe of 376 persons, male and female, positive and asymptomatic, monoparasitic and multiparasitic. They were divided in treatment groups with not less than 50 people. Monoparasitic patients were treated with 500, 400 and 300 mg of mebendazole, and multiparasitic patients with 500 and 400 mg of mebendazole. In all the cases the drug was used in single doses and its administration was supervised by the physician. Therapeutical response in monoparasitic and multiparasitic patients is shown. It is suggested to use mebendazole single doses of 300 mg in monoparasitic and of 400 mg in multiparasitic patients with an intensiveness of less than 5,000 h/g, as an alternative for treating asymptomatic populations with T. trichiura.

Adolescent↗
PubMed1991

Group membership, strength of group identification and perceptions of violence for locations in Northern Ireland.

118 undergraduate students, all of Northern Irish origin, were asked to rate 60 locations in Northern Ireland for violence and denominational composition. As expected from Social Identity Theory, subjects perceived ingroup locations as less violent than outgroup ones. Contrary to expectations, however, there was no increased differentiation of violence judgements with increasing strength of identity, for which two possible explanations were considered.

Humans↗
PubMed1989

Mutation is required to activate the p53 gene for cooperation with the ras oncogene and transformation.

Previous experiments have brought into question which amino acid sequence of the p53 oncogene product should be considered wild type and whether the normal protein is capable of cooperating with the ras oncogene to transform cells in culture. To address these questions, a series of p53 cDNA-genomic hybrid clones have been compared for the ability to cooperate with the ras oncogene in transformation assays. From these experiments, it has become clear that the amino acid alanine at position 135, in either the genomic clone or the cDNA clone, failed to produce a p53 protein that cooperated with the ras oncogene and transformed cells. Replacing alanine with valine at this position in either the genomic or the cDNA clone activated for transformation in this assay. Using restriction enzyme polymorphisms in the p53 gene, it was shown that normal mouse DNA encodes alanine at position 135 in the p53 protein. Thus, mutation is required to activate the p53 protein for cooperation with the ras oncogene. After cotransfection with the activated ras gene, the genomic p53 DNA clone always produced more transformed cell foci (1.7-fold) than similar cDNA clones and these foci were more readily cloned (3.6-fold) into permanent cell lines. A series of deletion mutants of the genomic p53 clone were employed to show that the presence of intron 4 in the p53 gene was sufficient to provide much enhanced clonability of transformed foci from culture dishes. The presence of introns in the p53 gene constructions also resulted in elevated levels of p53 protein in the p53-plus-ras-transformed cell lines. Thus, qualitative changes in the p53 protein are required to activate p53 for transformation with the oncogene ras. Quantitative improvements of transformation frequencies are associated with the higher expression levels of altered p53 protein that are provided by having one of the p53 introns in the transforming plasmid.

Amino Acid Sequence↗
PubMed1987

Relationship between simian virus 40 large tumor antigen expression and tumor formation in transgenic mice.

A line of transgenic mice containing the simian virus 40 (SV40) large tumor antigen gene under the control of the viral enhancer-promoter expressed this viral protein in the brains of these mice within the first 2 weeks after birth. Multiple foci of anaplastic cells formed in the choroid plexuses of these mice at 36 to 41 days after birth, and normal tissue coexisted with these transformed foci. Immunoperoxidase staining to detect the SV40 T antigen showed tumor-specific expression of nuclear T antigen at late times in tumor development, approximately 90 to 100 days and thereafter. The level of SV40 T antigen, on a per cell basis, appeared to be lower in the great majority of choroid plexus cells at earlier times in tumor development. These results suggest that low levels of tumor antigen (14 to 36 days) are present before detectable pathology (36 to 41 days) and the level of T antigen per cell is higher in rapidly growing late-stage tumors (older than 90 days).

Animals↗
PubMed1975

Changes in cellular enzyme levels and the inhibition of selective release of lysosomal hydrolases from macrophages by indomethacin.

Indomethacin increases the cellular levels of several lysosomal enzymes in cultures of mouse peritoneal macrophages exposed to the drug for periods of time ranging from one day to four weeks. This increase can be blocked by puromycin, an inhibitor of protein synthesis. Pretreatment of macrophages with indomethacin inhibits the selective release of lysosomal enzymes induced by a C-mucopolysaccharide peptidoglycan complex purified from the cell walls of Group A streptococci.

Animals↗
PubMedDate not supplied

Usefulness of the detection of Toxoplasma gondii antigens in AIDS patients.

Toxoplasmic encephalitis (TE) is a mayor cause of central nervous system infection in patients with acquired immunodeficiency syndrome (AIDS). Toxoplasma antibodies were detected in 56 of 79 patients with AIDS (71%), in the present study. Fourteen out of 57 seropositive patients developed TF (25%) and had Toxoplasma gondii antigen detected in their urine. For this, most of them received an effective therapy, with the subsequent disappearance of the symptoms and discontinuity of excretion of the T. gondii antigens. Our results suggest that the monitoring of T. gondii antigen in the urine of AIDS patients may be useful to decide on the proper time for therapy, as well as to avoid the beginning of neurologic signs in these patients.

AIDS-Related Opportunistic Infections↗