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S J Rasmussen

Publications and source records attributed to S J Rasmussen.

14 recordsLinked to original sources
PubMed2000

From childbearers to culture-bearers: transition to postchildbearing among Tuareg women.

This essay presents an analysis of women's lived experience of the transition from childbearing to postchildbearing among a division of the Tuareg in Niger, West Africa. The analysis suggests that biological realities associated with the end of fertility are interwined with local notions of qualities of ritual and social elderhood among women. It shows how changes in ritual and social roles, associated with increasing devotion to Islam and becoming a mother-in-law, are salient criteria for assuming the role and status of post-menopausal woman. The implication of this is very significant for biocultural reasons: menstruation and its cessation are not always literally the most important markers in female aging, in cross-cultural perspective.

Adult↗
PubMed2000

Parallel and divergent landscapes: cultural encounters in the ethnographic space of Tuareg medicine.

This essay explores the dialogue between the local quest for healing and the anthropological quest for healing knowledge, and local assessments of knowledge-power relationships in these processes. The context is medical discourse among the Tuareg of Niger Republic, West Africa, and my research experiences among these people. I examine local medical specialists and their traditional and changing practice in terms of how they perceive and respond to wider knowledge and power systems that impinge on local health care. Paramount in these systems are central state policies and medical anthropological research on healing, as these intersect in a postcolonial and post-separatist/rebellion setting. The essay analyzes parallels between the exchange of medicine and the exchange of knowledge and reflects upon how anthropological knowledge of African healing systems is constructed in an environment highly charged with power and danger--of political violence and economic crisis. The broader issue addressed here is how to give greater empowerment to local residents' voices in their "indigenous critique" of the medical anthropological project.

Anthropology, Cultural↗
PubMed1998

Failure to detect Chlamydia pneumoniae in atherosclerotic plaques of Australian patients.

Chlamydia pneumoniae is a recently reported, but common, respiratory tract pathogen. The organism has been detected by electron microscopy, immunocytochemistry, polymerase chain reaction (PCR) and recently culture within atherosclerotic plaques, suggesting a possible association between C. pneumoniae infection and atherosclerosis. Interestingly this association has not been found by all researchers. We examined 17 carotid endarterectomy specimens, 16 carotid arteries and 16 coronary arteries from autopsy specimens. They were examined by PCR for the presence of C. pneumoniae. In none of the 49 atherosclerotic samples examined was C. pneumoniae detected. The sensitivity of our PCR assay was rigorously tested and found to detect consistently fewer than ten elementary bodies. The association between C. pneumoniae and atherosclerosis is intriguing but has not yet been demonstrated in Australian patients.

Arteriosclerosis↗
PubMed1998

Chlamydia immunology.

Chlamydia trachomatis infection elicits both antibody and cell-mediated immune responses. Neutralizing antibody is serovar-specific and dependent upon conformational epitopes. CD4 lymphocytes (predominantly type 1 helper T cells) function in protection, but the role played by CD8 lymphocytes in protection or pathology is less well defined. Local cytokine induction is correlated with inflammation and effector influx, and may direct the acquired immune response.

Journal Article↗
PubMed1997

Secretion of proinflammatory cytokines by epithelial cells in response to Chlamydia infection suggests a central role for epithelial cells in chlamydial pathogenesis.

Chlamydia species infect epithelial cells at mucosal surfaces, and are major causes of sexually transmitted diseases. Infection is characterized by inflammation which is exacerbated upon reinfection, ultimately leading to tissue damage and scarring. Although central for the development of disease manifestations, little is known about the mechanisms that initiate and sustain the inflammatory response to Chlamydia. Infection of cervical and colonic epithelial cells with Chlamydia trachomatis and Chlamydia psittaci is shown in the present studies to upregulate mRNA expression and secretion of the proinflammatory cytokines IL-8, GRO alpha, GM-CSF, and IL-6. In contrast to the rapid, but transient, cytokine induction following infection with other invasive bacteria, the epithelial cytokine response to Chlamydia was delayed until 20-24 h after infection, persisted throughout the chlamydial growth cycle (2-4 d), and required bacterial protein synthesis. Moreover, epithelial cell lines and primary endocervical epithelial cells released IL-1alpha after Chlamydia infection, and increased secretion of the proinflammatory cytokines could be inhibited by anti-IL-1alpha. This suggests that IL-1alpha, released following lysis of infected epithelial cells, may amplify the inflammatory response by stimulating additional cytokine production by noninfected neighboring cells. These findings suggest a novel pathophysiologic concept wherein the acute host response to Chlamydia at mucosal surfaces is primarily initiated and sustained by epithelial cells, the first and major targets of chlamydial infection.

Actins↗
PubMed1997

Cross-reactive cytotoxic T-lymphocyte-mediated lysis of Chlamydia trachomatis- and Chlamydia psittaci-infected cells.

Cells infected with Chlamydia trachomatis are lysed by CD8+ T cells in vitro. The ability of C. trachomatis-elicited spleen cells to lyse target cells infected with other chlamydial strains was determined by measuring lysis by immune spleen cells of targets infected with three strains of C. trachomatis and two strains of C. psittaci. C. trachomatis (lymphogranuloma venereum [LGV])-elicited immune murine spleen cells lysed target cells infected with other C. trachomatis serovars, although with lower sensitivity than they lysed LGV-infected target cells. Additionally, target cells infected with C. psittaci were lysed by C. trachomatis-elicited immune spleen cells. Notably, C. psittaci-infected cells were lysed with greater efficiency than were cells infected with the C. trachomatis strain used to elicit the immune spleen cells. The lysis of C. psittaci-infected cells was characterized further and could be only partially accounted for by CD8+ T-cell-mediated lysis, the remaining lysis being due to an antigen-nonspecific component. These results indicate that mechanisms of immunologically mediated lysis differ between C. trachomatis- and C. psittaci-infected cells. This has important implications for the interpretation of results obtained with C. psittaci models of infection and immune resolution, particularly as they may be extrapolated to C. trachomatis.

Animals↗
PubMed1996

Cytotoxic-T-lymphocyte-mediated cytolysis of L cells persistently infected with Chlamydia spp.

Persistent chlamydial infections have been proposed as a means whereby chlamydiae evade immune resolution of infection. Such a mechanism would require evasion not only of the humoral immune responses but also of cell-mediated immune responses. We hypothesized that if such a mechanism is important, persistently infected cells should not be recognized by cytotoxic T cells. Persistent infections were simulated in vitro by treatment of Chlamydia trachomatis- or Chlamydia psittaci-infected cells with gamma interferon (IFN-gamma), penicillin, or tryptophan depletion. Cultures were examined for induction of a chlamydial stress response (measured by transcription of groesl RNA) and for the effects on viability, infectivity, morphology, and immune recognition. Although both IFN-gamma and penicillin induced aberrant chlamydial morphology and growth, we did not find evidence that these treatments elicited a classical stress response. In addition, T-cell-mediated lysis of Chlamydia-infected target cells treated with IFN-gamma or penicillin or grown in tryptophan-deficient media was examined. The immune cell-mediated lysis of these treated infected cells demonstrated that despite the effects of these compounds on chlamydial growth and development, the infected cells continued to be efficiently recognized and killed by cytotoxic T cells. Thus, it seems unlikely that these in vitro models of persistence represent functional mechanisms to evade immune clearance.

Base Sequence↗
PubMed1995

Reduction of quinones and radicals by a plasma membrane redox system of Phanerochaete chrysosporium.

Quinones which are produced during the mineralization of lignin and xenobiotics by the white rot fungus Phanerochaete chrysosporium were reduced by a plasma membrane redox system of the fungus. Both intracellular enzymes and the plasma membrane redox system were able to reduce 1,4-benzoquinone. However, no quinone reductase activity was observed with the extracellular culture fluid. The intracellular reductase activity had a pH optimum between 6.0 and 7.0 and a Km of 150 microM. Reduction of 1,4-benzoquinone by the plasma membrane redox system had a pH optimum between 7.5 and 8.5 and exhibited saturation kinetics (Km = 11 microM, Vmax = 16 nmol/min/mg mycelia dry weight). Ferricyanide totally inhibited the quinone reduction until the ferricyanide was completely reduced by the membrane. Radicals (chlorpromazine and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS)) that can be generated by the lignin peroxidases were also reduced by the plasma membrane redox system. Reduction of the ABTS cation radical also totally inhibited quinone reduction until the radical was completely reduced. Finally, quinone reduction rates were identical after the reduction of ferricyanide, ABTS cation radical, or quinone, suggesting that the plasma membrane redox system may actually protect the fungus from oxidative damage from free radicals generated by the lignin degrading system.

Basidiomycota↗
PubMed1995

Reductions catalyzed by a quinone and peroxidases from Phanerochaete chrysosporium.

A quinone produced from veratryl alcohol by lignin peroxidase from the white rot fungus Phanerochaete chrysosporium was tested for its ability to mediate reduction. The quinone (2-hydroxymethyl-5-methoxy-1,4-benzoquinone), reduced chemically or by cellobiose:quinone reductase isolated from cultures of the fungus, mediated the reduction of cytochrome c in reactions containing either Mn(III), a manganese-dependent peroxidase, Mn(II) and H2O2, or lignin peroxidase and H2O2. Formation of the semiquinone, the species responsible for reducing cytochrome c, was observed by electron spin resonance spectroscopy in these reactions. The production of the quinone was observed in the extracellular fraction of cultures grown under nutrient nitrogen-deficient conditions (2.4 mM ammonium tartrate) for over 10 days, starting on Day 2, but not under nutrient nitrogen-sufficient conditions. These results suggest that a quinone produced by lignin peroxidase can serve as a physiological mediator of reductive reactions catalyzed by the fungal peroxidases.

Benzoquinones↗
PubMed1994

Female sexuality, social reproduction, and the politics of medical intervention in Niger: Kel Ewey Tuareg perspectives.

This essay explores connections between political institutions, forms of power, and women's health care concerns from a cultural anthropological perspective. I focus on the roles of different medical establishments among the Kel Ewey Tuareg of Niger--Western-European sponsored, central state, traditional herbalism and Islamic scholarship--in creating, maintaining, and disputing these constructs, through the invention and elaboration of disease categories and through the selective application of medical and reproductive models and technology to women. I also explore women's attempts to manage these forces, as they draw upon a cultural inventory that is alternately supportive and in conflict with their interests.

Culture↗
PubMed1993

Detection of Chlamydia trachomatis in urine using enzyme immunoassay and DNA amplification.

The suitability of urine specimens for the detection of Chlamydia trachomatis infections in men was assessed. Urethral swabs from 301 patients were cultured for C. trachomatis, and the results were compared with results obtained from Chlamydiazyme. The results of 298 specimens were also compared with results obtained from PCR analysis of first-void urine specimens. The sensitivity of confirmed Chlamydiazyme analysis was 93% and the specificity was greater than 99% compared with culture. The sensitivity of the PCR method was 100% compared with culture. Chlamydia trachomatis was detected by PCR in an additional three specimens from which C. trachomatis could not be cultured. Urine appears to be an appropriate specimen for the detection of C. trachomatis antigens and nucleic acids.

Adolescent↗
PubMed1992

Reflections on Tamazai, a Tuareg idiom of suffering.

In this essay, I explore ways in which the theatrical and the medical are inextricably mixed and affect each other, in the Nigerien Tuareg idiom of tamazai. Tamazai is locally-described as "an illness of the heart and soul, not curable by Koranic verses," but by exorcism of spirits. A case study and analysis of healing rituals demonstrate how this idiom communicates women's relationships and empowers dramatic framing.

Adult↗
PubMed1992

PCR detection and differentiation of Chlamydia pneumoniae, Chlamydia psittaci and Chlamydia trachomatis.

A PCR-based system was developed for the detection and differentiation of Chlamydia trachomatis, Chlamydia psittaci and Chlamydia pneumoniae. A conserved 145 bp fragment of the chlamydial omp1 gene was amplified from all three species. The three species were then differentiated from each other by digestion of this PCR product with restriction enzymes Eco RI and either Hind III or Pst I. The system was shown to work for two strains of C. pneumoniae, 11 strains of C. psittaci and 10 serovars of C. trachomatis, and had a sensitivity of less than 10 chlamydial elementary bodies. This method was also applicable to the detection of C. trachomatis in conjunctival and nasopharyngeal swabs.

Adult↗