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1.
J Pharmacol Exp Ther ; 378(2): 184-196, 2021 08.
Article in English | MEDLINE | ID: mdl-34011530

ABSTRACT

Ferroptosis is a form of oxidative cell death that is increasingly recognized as a key mechanism not only in neurodegeneration but also in regulated cell death, causing disease in other tissues. In neurons, major hallmarks of ferroptosis involve the accumulation of lipid reactive oxygen species (ROS) and impairment of mitochondrial morphology and function. Compounds that interfere with ferroptosis could provide novel treatment options for neurodegenerative disorders and other diseases involving ferroptosis. In the present study, we developed new compounds by refining structural elements of the BH3 interacting-domain death agonist inhibitor BI-6c9, which was previously demonstrated to block ferroptosis signaling at the level of mitochondria. Here, we inserted an antioxidative diphenylamine (DPA) structure to the BI-6c9 structure. These DPA compounds were then tested in models of erastin, and Ras-selective lethal small molecule 3 induced ferroptosis in neuronal HT22 cells. The DPA compounds showed an increased protective potency against ferroptotic cell death compared with the scaffold molecule BI-6c9. Moreover, hallmarks of ferroptosis such as lipid, cytosolic, and mitochondrial ROS formation were abrogated in a concentration- and time-dependent manner. Additionally, mitochondrial parameters such as mitochondrial morphology, mitochondrial membrane potential, and mitochondrial respiration were preserved by the DPA compounds, supporting the conclusion that lipid ROS toxicity and mitochondrial impairment are closely related in ferroptosis. Our findings confirm that the DPA compounds are very effective agents in preventing ferroptotic cell death by blocking ROS production and, in particular, via mitochondrial protection. SIGNIFICANCE STATEMENT: Preventing neuronal cells from different forms of oxidative cell death was previously described as a promising strategy for treatment against several neurodegenerative diseases. This study reports novel compounds based on a diphenylamine structure that strongly protects neuronal HT22 cells from ferroptotic cell death upon erastin and Ras-selective lethal small molecule 3 induction by preventing the development of different reactive oxygen species and by protecting mitochondria from ferroptotic impairments.


Subject(s)
Ferroptosis , Cell Death , Diphenylamine , Mitochondria
2.
Ophthalmologe ; 117(4): 331-335, 2020 Apr.
Article in German | MEDLINE | ID: mdl-32108251

ABSTRACT

BACKGROUND: According to § 73c of the Social Security Codebook V (SGB V), the AOK health insurance structural contract regulates the treatment of macular diseases by intravitreal drug administration (IVOM) in Baden-Württemberg (BW). Quality assurance is a central part of the agreement in order to ensure the high quality as well as effective and sufficient care of patients. MATERIAL AND METHODS: Every year at least 2% of the cases of the 254 currently participating surgeons are evaluated in a pseudonymized procedure by a panel of experts based on the billing data. Based on quality parameters, such as accuracy of diagnosis, quality and completeness of treatment documents and adherence to treatment pathways, the Medical Advisory Board recommends sanctions or facilitation of controls. The overall assessment of an expert opinion is based on a matrix of the evaluated quality parameters. The transmission of findings and expert opinions is digital and web based. Each surgeon has access to a comparative analysis of the quality data over time (benchmarking). RESULTS: In the first 11 quality assurance rounds, a total of 3639 expert opinions were made by a total of 20 reviewers. With respect to the quality parameter "diagnosis", the surgeon and the expert opinion differed in an average 7% of cases. Sanctions or facilitation of control by changing the sample were recommended 138 times for 80 surgeons in the first 10 quality assurance rounds. Financial sanctions or exclusion from contracts were each decided four times by the steering committee. DISCUSSION: The digital, web-based quality assurance system presented here within the framework of the IOVM structural contract of the AOK-BW should be perceived as an opportunity to classify and improve one's own quality level with respect to intravitreal treatment of retinal diseases. The current focus of quality assurance is on diagnosis and adherence to the disease-specific treatment recommendations of the professional societies. If the analysis of data could be extended to individual patient histories over time, quality assurance could be better used for questions of health services research.


Subject(s)
Health Services Research , Quality Assurance, Health Care , Germany , Humans
3.
Sci Adv ; 5(4): eaav3006, 2019 04.
Article in English | MEDLINE | ID: mdl-30949578

ABSTRACT

Protected areas (PAs) are fundamental for biodiversity conservation, yet their impacts on nearby residents are contested. We synthesized environmental and socioeconomic conditions of >87,000 children in >60,000 households situated either near or far from >600 PAs within 34 developing countries. We used quasi-experimental hierarchical regression to isolate the impact of living near a PA on several aspects of human well-being. Households near PAs with tourism also had higher wealth levels (by 17%) and a lower likelihood of poverty (by 16%) than similar households living far from PAs. Children under 5 years old living near multiple-use PAs with tourism also had higher height-for-age scores (by 10%) and were less likely to be stunted (by 13%) than similar children living far from PAs. For the largest and most comprehensive socioeconomic-environmental dataset yet assembled, we found no evidence of negative PA impacts and consistent statistical evidence to suggest PAs can positively affect human well-being.


Subject(s)
Conservation of Natural Resources , Health Status , Public Health , Biodiversity , Developing Countries , Ecosystem , Family Characteristics , Geography , Global Health , Humans , Models, Theoretical
4.
J Water Sanit Hyg Dev ; 7(2): 331-339, 2017.
Article in English | MEDLINE | ID: mdl-28966785

ABSTRACT

This study considers potential policy responses to the still very high levels of exposure to arsenic (As) caused by drinking water from shallow tubewells in rural Bangladesh. It examines a survey of 4,109 households in 76 villages of Araihazar upazila conducted two years after a national testing campaign swept through the area. The area is adjacent to the region where a long-term study was initiated in 2000 and where households are periodically reminded of health risks associated with well-water elevated in As. Results confirm that testing spurs switching away from unsafe wells, although the 27% fraction who switched was only about half of that in the long-term study area. By village, the fraction of households that switched varied with the availability of safe wells and the distance from the long-term study area. Lacking follow-up testing, two years only after the campaign 21% of households did not know the status of their well and 21% of households with an unsafe well that switched did so to an untested well. Well testing is again urgently needed in Bangladesh and should be paired with better ways to raise awareness and the installation of additional deep community wells.

5.
BMC Infect Dis ; 16: 363, 2016 Aug 02.
Article in English | MEDLINE | ID: mdl-27484187

ABSTRACT

BACKGROUND: Cryptosporidium spp. is a ubiquitous parasite affecting humans as well as domestic and wild vertebrates, causing diarrhea in both immunocompetent and immunocompromised hosts worldwide. Its transmission occurs primarily by the fecal-oral route. In humans, C. parvum and C. hominis are the most prevalent species, whereas immunocompetent and immunocompromised individuals can also be infected by other zoonotic species. Renal transplant patients are prone to develop cryptosporidiosis, which can induce severe and life-threatening diarrhea. CASE PRESENTATION: We report here a series of nearly concomitant cases of acute symptomatic cryptosporidiosis in three renal transplant patients attending the Strasbourg University Hospital Nephrology Unit. The clinical presentation was persistent diarrhea and acute renal failure. The diagnosis was confirmed by microscopic stool examination using a modified Ziehl-Neelsen staining method and species identification by molecular tools. All patients were treated with nitazoxanide and recovered from diarrhea after 14 days of therapy. CONCLUSION: Genotypic species identification was not consistent with an epidemic context, thus underlining the need for genotyping to monitor at risk patients.


Subject(s)
Cross Infection/parasitology , Cryptosporidiosis/transmission , Cryptosporidium/pathogenicity , Kidney Transplantation , Acute Kidney Injury/etiology , Acute Kidney Injury/parasitology , Adult , Animals , Coccidiostats/therapeutic use , Cryptosporidiosis/complications , Cryptosporidiosis/drug therapy , Cryptosporidium/genetics , Diarrhea/etiology , Diarrhea/parasitology , Feces/parasitology , Female , Humans , Immunocompromised Host , Male , Middle Aged , Nitro Compounds , Thiazoles/therapeutic use
6.
J Small Anim Pract ; 56(12): 720-2, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26017189

ABSTRACT

A 12-year-old, castrated male, domestic long-haired cat experienced massive haemorrhage associated with an incision of a swelling on the neck 2 weeks after right-sided ventral bulla osteotomy. Emergent control of haemorrhage was gained through unilateral carotid artery ligation. Cardiopulmonary resuscitation was provided in conjunction with massive blood transfusion. The cat made an unremarkable recovery. Carotid artery pseudoaneurysm due to surgical disruption of the carotid artery during ventral bulla osteotomy, specifically through the use of self-retaining retractors, was suspected. This case highlights the development of pseudoaneurysm as a potential complication of head and neck surgery, and additionally describes a case of massive transfusion in a cat.


Subject(s)
Aneurysm, False/veterinary , Carotid Arteries , Cat Diseases/diagnosis , Postoperative Hemorrhage/veterinary , Aneurysm, False/diagnosis , Animals , Cats , Diagnosis, Differential , Male , Osteotomy/veterinary , Postoperative Hemorrhage/diagnosis
7.
Neurology ; 78(2): 91-101, 2012 Jan 10.
Article in English | MEDLINE | ID: mdl-22232050

ABSTRACT

OBJECTIVE: To preliminarily assess the safety and efficacy of transdermal nicotine therapy on cognitive performance and clinical status in subjects with mild cognitive impairment (MCI). METHODS: Nonsmoking subjects with amnestic MCI were randomized to transdermal nicotine (15 mg per day or placebo) for 6 months. Primary outcome variables were attentional improvement assessed with Connors Continuous Performance Test (CPT), clinical improvement as measured by clinical global impression, and safety measures. Secondary measures included computerized cognitive testing and patient and observer ratings. RESULTS: Of 74 subjects enrolled, 39 were randomized to nicotine and 35 to placebo. 67 subjects completed (34 nicotine, 33 placebo). The primary cognitive outcome measure (CPT) showed a significant nicotine-induced improvement. There was no statistically significant effect on clinician-rated global improvement. The secondary outcome measures showed significant nicotine-associated improvements in attention, memory, and psychomotor speed, and improvements were seen in patient/informant ratings of cognitive impairment. Safety and tolerability for transdermal nicotine were excellent. CONCLUSION: This study demonstrated that transdermal nicotine can be safely administered to nonsmoking subjects with MCI over 6 months with improvement in primary and secondary cognitive measures of attention, memory, and mental processing, but not in ratings of clinician-rated global impression. We conclude that this initial study provides evidence for nicotine-induced cognitive improvement in subjects with MCI; however, whether these effects are clinically important will require larger studies. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that 6 months of transdermal nicotine (15 mg/day) improves cognitive test performance, but not clinical global impression of change, in nonsmoking subjects with amnestic MCI.


Subject(s)
Cognitive Dysfunction/drug therapy , Nicotine/administration & dosage , Nicotinic Agonists/administration & dosage , Administration, Cutaneous , Aged , Aged, 80 and over , Attention/drug effects , Attention/physiology , Body Weight/drug effects , Cognitive Dysfunction/psychology , Double-Blind Method , Female , Follow-Up Studies , Humans , Male , Mental Recall/drug effects , Neuropsychological Tests , Pilot Projects , Psychiatric Status Rating Scales , Reaction Time/drug effects , Vital Signs/drug effects
8.
J Fr Ophtalmol ; 32(10): 742-9, 2009 Dec.
Article in French | MEDLINE | ID: mdl-19932524

ABSTRACT

BACKGROUND/PURPOSE: Toxoplasmosis is the most common cause of posterior uveitis in immunocompetent subjects. Taking into account the opposing needs of limiting parasite multiplication and minimizing tissue destruction, the infection imbalance most often involves CD4 and CD8 T lymphocytes that play the lead role in adaptive immunity to T. gondii. The aims of our study were to develop murine models of toxoplasmosis and to study the immune responses to the infection. METHODS: Two murine models were studied: (i) intravitreal injection of T. gondii (primary infection) and (ii) intraperitoneal inoculation at birth and reinfection by intravitreal injection. Clinical and histological data were determined. mRNA-cytokine levels were measured in ocular samples obtained from mice with toxoplasma chorioretinitis using RT-PCR. RESULTS: Intravitreal injection of T. gondii led to chorioretinitis. Primary infection was characterized by severe chorioretinitis when compared with reinfection. mRNA levels of IFN-gamma, TNF-alpha, and iNOS were increased in infected mice. DISCUSSION: TH1 cells may mitigate chorioretinitis by limiting T. gondii proliferation. Further studies are needed to explore ocular immune regulation. These primary results may open new in vivo therapeutic approaches.


Subject(s)
Chorioretinitis/immunology , Chorioretinitis/parasitology , Disease Models, Animal , Toxoplasmosis, Ocular/immunology , Animals , Chorioretinitis/genetics , Gene Expression Profiling , Mice , Toxoplasmosis, Ocular/genetics
9.
Int J Parasitol ; 39(4): 481-7, 2009 Mar.
Article in English | MEDLINE | ID: mdl-18838076

ABSTRACT

The severity of congenital toxoplasmosis depends on the stage of the pregnancy at which infection takes place. Infection during the first trimester generally leads to miscarriage, through an unknown mechanism. Toxoplasma gondii infection is normally controlled by a strong Th1-type response with IFN-gamma production. To investigate the mechanisms of foetal resorption induced by T. gondii, pregnant Swiss-Webster mice were infected 1 day post coïtum with the avirulent Me49 strain. Mated recipients were examined at mid-gestation. Few parasites and no cytolytic effects were detected 10 days post coïtum in implantation sites undergoing resorption. Resorption was accompanied by haemorrhage, spiral artery dilation, hypocellularity of the decidua basalis, apoptosis of placental cells, a decline in uterine mature natural killer cell numbers, increased indoleamine 2,3-dioxygenase mRNA levels and reduced IL-15 mRNA levels. Given the role of IFN-gammaR(-/-) in non-infectious abortive processes, IFN-gammaR(-/-) mice were used to investigate its local role in T. gondii-induced foetal resorption. IFN-gammaR(-/-) mice showed 50% less foetal resorption than their wild-type counterparts, and spiral artery dilation and placental cell apoptosis were both abolished. These results strongly suggest that, at least in mice, T. gondii-induced abortion in early gestation is not due to a direct action of the parasite at the maternofoetal interface but rather to massive IFN-gamma release.


Subject(s)
Apoptosis/immunology , Fetal Resorption/immunology , Interferon-gamma/analysis , Toxoplasmosis, Animal/immunology , Animals , Cytokines/analysis , Disease Models, Animal , Female , Fetal Resorption/parasitology , Fetal Resorption/pathology , Immunohistochemistry , Indoleamine-Pyrrole 2,3,-Dioxygenase/analysis , Mice , Mice, Knockout , Necrosis , Placenta/immunology , Placenta/parasitology , Placenta/pathology , Pregnancy/immunology , Pregnancy Complications, Parasitic/immunology , RNA, Messenger/analysis , Receptors, Interferon , Reverse Transcriptase Polymerase Chain Reaction , Toxoplasmosis, Animal/pathology , Uterus/enzymology , Uterus/immunology , Uterus/pathology , Interferon gamma Receptor
10.
Parassitologia ; 50(1-2): 55-8, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18693558

ABSTRACT

Toxoplasma gondii is one of the few pathogens that can cross the placenta. Frequency and severity of transmission vary with gestational age. While acquired toxoplasmosis is already well explored, the control of maternal-foetal transmission of the parasite remains almost unknown. This is partly due to inherent inadequacies of animal models. This review summarises the studies which have been undertaken and shows that the mouse is a valuable model despite obvious differences to the human case. The paramount role of the cellular immune response during primary infection has been consistently shown. Surprisingly, IFN-g has a dual role in this process. While its beneficial effects in the control of toxoplasmosis are well known, it also seems to have transmission-enhancing effects within the placenta and can also directly harm the developing foetus. This shows the importance of designing vaccines which protects both mother and foetus. Therefore, it is useful to study the mechanisms of natural resistance against transmission during a secondary infection. In this setting, the process is more complicated, involving cellular, but also humoral components of the immune system. In summary, even if the whole process is far from being elucidated, important insights have been gained so far which will help us to undertake rational vaccine research.


Subject(s)
Infectious Disease Transmission, Vertical/prevention & control , Pregnancy Complications, Infectious/prevention & control , Protozoan Vaccines , Toxoplasma/immunology , Toxoplasmosis, Animal/prevention & control , Toxoplasmosis, Congenital/prevention & control , Adult , Animals , Female , Humans , Immunity, Cellular , Immunity, Innate , Infant, Newborn , Maternal-Fetal Exchange/immunology , Mice , Mice, Inbred BALB C , Mice, Inbred CBA , Pregnancy , Pregnancy Complications, Infectious/blood , Pregnancy Complications, Infectious/parasitology , Prenatal Care , Toxoplasmosis, Animal/transmission , Toxoplasmosis, Congenital/transmission
11.
Parasite Immunol ; 30(9): 487-90, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18627508

ABSTRACT

This study investigated the effect of infection with the apicomplexan parasite Toxoplasma gondii, in combination with the concomitant cytokine environment (IFN-gamma/TNF-alpha), on adhesion of THP-1 monocytic cells to MRC-5 fibroblasts. Surprisingly, infection of THP-1 cells decreased their adhesion to the MRC-5 cell monolayer. This decrease was compensated by IFN-gamma/TNF-alpha stimulation. In contrast, infection of MRC-5 cells significantly increased adhesion, which was synergistically augmented by cytokine stimulation. Levels of ICAM-1 (CD54) on MRC-5 cells, as well as LFA-1 (CD11a) on THP-1 cells, were not changed by infection, neither in resting, nor in cytokine stimulated cells. These results show that T. gondii infection alters adhesion properties and reactivity to cytokine stimulation in a cell-specific way.


Subject(s)
Fibroblasts/immunology , Monocytes/immunology , Toxoplasma/immunology , Toxoplasmosis/immunology , Animals , Cell Adhesion , Cell Line , Cytokines/immunology , Humans , Monocytes/cytology , Toxoplasma/cytology
12.
Parasitology ; 134(Pt 13): 1895-902, 2007.
Article in English | MEDLINE | ID: mdl-17958925

ABSTRACT

Toxoplasma gondii is one of the few pathogens that can cross the placenta. Frequency and severity of transmission vary with gestational age. While the control of acquired toxoplasmosis is already well explored, the control of materno-foetal transmission of the parasite remains almost unknown. This is partly due to the lack of an animal model to study this process. This review summarises the studies which have been undertaken and shows that the mouse is a valuable model despite obvious differences to the human case. The paramount role of the cellular immune response has been shown by several experiments. However, IFN-gamma has a dual role in this process. While its beneficial effects in the control of toxoplasmosis are well known, it also seems to have transmission-enhancing effects and can also directly harm the developing foetus. The ultimate goal of these studies is to develop a vaccine which protects both mother and foetus. Therefore, it is useful to study the mechanisms of natural resistance against transmission during a secondary infection. In this setting, the process is more complicated, involving both cellular and also humoral components of the immune system. In summary, even if the whole process is far from being elucidated, important insights have been gained so far which will help us to undertake rational vaccine research.


Subject(s)
Interferon-gamma/metabolism , Toxoplasmosis, Congenital/metabolism , Toxoplasmosis, Congenital/physiopathology , Female , Humans , Interferon-gamma/immunology , Pregnancy , Toxoplasmosis, Congenital/immunology
14.
Ther Umsch ; 63(6): 423-32, 2006 Jun.
Article in German | MEDLINE | ID: mdl-16841580

ABSTRACT

There has been an increasing number of patients with artificial nutritional support via tubes in the last few years. The inpatient setting as well as the outpatient setting is affected by this matter Physicians, nurses, pharmacists, and relatives have to deal with issues of drug application via tubes. In many cases a few drugs are to be administred via tube in addition to the artificial nutrition. The choice of the appropriate drug is of importance beyond other things to avoid intricacies and to ensure a safe and effective therapy.


Subject(s)
Catheterization/instrumentation , Catheterization/methods , Dosage Forms , Drug Delivery Systems/instrumentation , Drug Delivery Systems/methods , Enteral Nutrition/methods , Drug Administration Routes , Drug Administration Schedule , Germany , Humans
15.
J Neurol Neurosurg Psychiatry ; 77(7): 841-9, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16574735

ABSTRACT

BACKGROUND: Post-traumatic amnesia (PTA) tests that record different PTA durations in the same patient, thereby raising measurement accuracy issues, have been reported previously. A major problem lies in determining the end point of PTA. AIMS: To delineate areas of discrepancy in PTA tests and to provide independent verification for a criterion signalling emergence from PTA. METHODS: In a randomised design, two related PTA procedures were compared, one purportedly more difficult (Westmead PTA Scale, WPTAS) than the other (Modified Oxford PTA Scale, MOPTAS). Eighty two patients in the early stages of PTA were examined daily until emergence, by using the Galveston Orientation and Amnesia Test (GOAT) and the WPTAS/MOPTAS. A short battery of cognitive and behavioural measurements was made on three occasions: at the early stage of PTA (time 1), towards the end of PTA when the maximum score (12/12) was first obtained (time 2) and at the traditional criterion for emergence (scoring 12/12 for 3 consecutive days; time 3). RESULTS: No significant difference was recorded in PTA duration between the MOPTAS and WPTAS. Both scales recorded longer PTA durations than the GOAT. By using Kaplan-Meier survival analyses, the WPTAS was found to show a more protracted pattern of emergence at the end stage of PTA than the MOPTAS. A time lag of > or = 1 week in the resolution of disorientation as compared with amnesia was observed in 59% cases. Significant improvements occurred on all independent measurements between time 1 and time 2, but on only 2 of 5 cognitive measurements between time 2 and time 3. CONCLUSIONS: Although no significant differences in the duration of PTA on the MOPTAS/WPTAS were recorded, emergence from the late stages of PTA occurred more promptly with the MOPTAS. The need for inclusion of both orientation and memory items in PTA tests is highlighted by the frequency of disorientation-amnesia dissociations. The patterns of results on the independent measures suggest that patients who are in PTA for > 4 weeks have probably emerged from PTA when they first score 12/12 on the MOPTAS/WPTAS, and this criterion can replace the traditional criterion.


Subject(s)
Amnesia/diagnosis , Amnesia/etiology , Psychological Tests/standards , Stress Disorders, Post-Traumatic/complications , Adolescent , Adult , Aged , Endpoint Determination , Female , Humans , Male , Middle Aged , Psychometrics , Recognition, Psychology , Reproducibility of Results
16.
Parasite Immunol ; 26(8-9): 315-8, 2004.
Article in English | MEDLINE | ID: mdl-15679627

ABSTRACT

In the BALB/c mouse model, primary infection with Toxoplasma gondii during the second third of gestation leads to a high percentage of infected foetuses. However, immunity induced by infection contracted before pregnancy prevents parasites from crossing the placenta and completely protects the foetuses, as well as the pregnant women. In order to clarify the roles of CD4+, CD8+ T lymphocytes and IFN-gamma in this protection, pregnant BALB/c mice were treated with depleting monoclonal antibodies against CD4, CD8, IFN-gamma, or control antibody. Only the foetuses of the groups treated with anti-CD8 and anti-IFN-gamma antibodies developed congenital toxoplasmosis. The maternal production of IFN-gamma was depressed in the mice depleted of CD4 and CD8 cells (P < 0.001). Determination of the blood parasite load demonstrated that materno-foetal transmission of T. gondii correlates with maternal parasitaemia. Together, these results show that CD8+ T lymphocytes and IFN-gamma play an important role in protection against congenital toxoplasmosis during reinfection.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Infectious Disease Transmission, Vertical , Interferon-gamma/immunology , Toxoplasma/immunology , Toxoplasmosis, Congenital/immunology , Toxoplasmosis, Congenital/transmission , Animals , CD4-Positive T-Lymphocytes/parasitology , CD8-Positive T-Lymphocytes/parasitology , Female , Flow Cytometry , Interferon-gamma/blood , Male , Mice , Mice, Inbred BALB C , Parasitemia/immunology , Polymerase Chain Reaction , RNA, Viral/chemistry , RNA, Viral/genetics , Specific Pathogen-Free Organisms , Toxoplasmosis, Congenital/parasitology
17.
Parasitol Res ; 90(5): 415-20, 2003 Aug.
Article in English | MEDLINE | ID: mdl-12750994

ABSTRACT

During experimental Angiostrongylus costaricensis infections in several inbred mouse strains, genetic factors as well as different cytokine secretion patterns have recently been shown to play a role in the outcome of infection in terms of morbidity and mortality, e.g. BALB/c mice show a high and C57BL/6 mice a low mortality during the acute phase of infection. In this study, C57BL/6 MHC-II knockout mice infected with A. costaricensis did not show increased mortality during the acute phase of infection when compared with wild-type mice. Furthermore, MHC-II knockout mice showed a strongly diminished parasite-specific humoral and cellular immune response, which can be explained by the nearly complete lack of CD4+ T cells in the periphery. This defect in MHC-II genes, the lack of CD4+ T cells, and the resulting cellular and humoral unresponsiveness resulted in a three times higher output of first-stage larvae in feces compared with wild-type animals. The results indicate that during experimental A. costaricensis infection a parasite-specific immune response, directed via MHC-II molecules and CD4+ T cells, is not essential for the survival of C57BL/6 mice during the acute phase of infection, whereas the elimination of first-stage larvae seems to be regulated by a MHC-II- and CD4+ T-cell-dependent mechanism.


Subject(s)
Angiostrongylus , Genes, MHC Class II , Strongylida Infections/immunology , Angiostrongylus/immunology , Angiostrongylus/physiology , Animals , Antibodies, Helminth/blood , Antigens, Helminth/immunology , CD4-Positive T-Lymphocytes/immunology , Feces/parasitology , Immunoglobulins/blood , Interferon-gamma/biosynthesis , Interleukins/biosynthesis , Lymphocyte Activation , Mice , Mice, Inbred C57BL , Mice, Knockout , Mitogens , Spleen/immunology , Strongylida Infections/parasitology
18.
J Head Trauma Rehabil ; 16(6): 525-42, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11732969

ABSTRACT

OBJECTIVES: To determine a set of variables that would reliably predict duration of posttraumatic amnesia (PTA) in patients with traumatic brain injury and to test the efficacy of the model. DESIGN: Simultaneous standard multiple regression analyses. PARTICIPANTS: Two independent samples of patients with traumatic brain injury who were in the early stages of PTA: a test sample (n = 61) and a cross-validation sample (n = 25). MAIN OUTCOME MEASURE: The Modified Oxford PTA Scale (MOPTAS) is a 12-item test measuring orientation (8 items) and anterograde memory (4 items). The Galveston Orientation and Amnesia Test (GOAT) was also used on a subset of the test sample. PROCEDURE: Patients were examined daily until they emerged from PTA. RESULTS: A statistically significant model, using three predictor variables, was derived that reliably predicted duration of PTA, accounting for 89% of the variance. A second model, using two predictor variables readily available to the clinician (day posttrauma on which PTA testing began and aggregate PTA scores over the first 5 days of testing) had comparable predictive accuracy. A third model, using GOAT data, was also statistically significant and successfully accounted for 72% of the variance. The MOPTAS model showed excellent application to an independent (validation) sample, with an intraclass correlation coefficient between observed and predicted durations of PTA of 0.95. Regression equations for all three models are provided to enable calculation of the predicted duration of PTA. CONCLUSIONS: These models can be readily applied in clinical practice and will provide clinically useful estimates of the duration of PTA within the first week of testing after admission to rehabilitation. This information will be important in terms of family counseling and planning of rehabilitation programs.


Subject(s)
Amnesia, Transient Global/diagnosis , Amnesia, Transient Global/etiology , Brain Injuries/complications , Brain Injuries/rehabilitation , Adolescent , Adult , Age Distribution , Amnesia, Transient Global/epidemiology , Brain Injuries/diagnosis , Cohort Studies , Cross-Sectional Studies , Female , Humans , Incidence , Injury Severity Score , Male , Middle Aged , Multivariate Analysis , Neurologic Examination , Predictive Value of Tests , Regression Analysis , Risk Factors , Sampling Studies , Sex Distribution , Time Factors , Trauma Severity Indices
19.
Acta Trop ; 80(1): 59-68, 2001 Sep 01.
Article in English | MEDLINE | ID: mdl-11495645

ABSTRACT

In our experimental study we were able to show that the contrasting outcome of Angiostrongylus costaricensis infection in C57BL/6 and BALB/c mice, in respect of morbidity and mortality, can be explained by divergent cellular immune responses and a different cytokine pattern in each strain. In BALB/c mice (i.e. those with high mortality), the initial high proliferation of ConA or LPS stimulated spleen cells dropped to very low levels after 2 weeks post-infection (p.i.), whereas in C57BL/6 mice (i.e. those with low mortality), only a minor reduction in lymphoproliferative responses after mitogenic stimulation was observed. The specific proliferation of spleen cells after stimulation with A. costaricensis adult worm antigen remained low in BALB/c mice throughout the experiment, but showed an augmented proliferation in C57BL/6 mice, especially from 2 weeks p.i. onwards. The mitogen-induced production of Th2-type cytokines (IL-4, IL-5, IL-6, IL-10) in spleen cell cultures remained low in BALB/c mice until 4 weeks p.i., but production of Th1-type cytokines (IL-2, IFN-gamma) was highly elevated at 14 and 28 days p.i. In C57BL/6 mice, an upregulated and balanced production of both Th1- and Th2-type cytokines was measured during the course of infection. In summary, a polarization of the immune response towards cellular hyporesponsiveness and a predominantly Th1 cytokine profile was observed in A. costaricensis infected BALB/c mice, which may contribute to pathogenesis and increased morbidity.


Subject(s)
Angiostrongylus , Antibodies, Helminth/blood , Cytokines/immunology , Spleen/immunology , Strongylida Infections/immunology , Animals , Antibody Formation , Cells, Cultured , Cytokines/analysis , Female , Interferon-gamma/analysis , Interferon-gamma/biosynthesis , Interleukin-10/analysis , Interleukin-10/biosynthesis , Interleukin-2/analysis , Interleukin-2/biosynthesis , Interleukin-4/analysis , Interleukin-4/biosynthesis , Interleukin-5/analysis , Interleukin-5/biosynthesis , Lymphocyte Activation , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mitogens , Strongylida Infections/parasitology , Strongylida Infections/pathology , Time Factors
20.
Parasitology ; 122(Pt 6): 641-9, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11444617

ABSTRACT

Filarial infections of humans are chronic diseases. Despite an ongoing immune response, adult filariae continuously produce their offspring, the microfilariae (Mf), which are able to persist in sufficient numbers to ensure transmission. In this study, host- and parasite-derived factors, which contribute to persistence of Mf, were investigated using the filariasis model of Litomosoides sigmodontis in mice. Different strains of mice were found to differ widely in their capability to eliminate circulating Mf. Studies of congenic mouse strains showed that early and rapid clearance of Mf was mediated by activation pathways relevant to innate immunity, whereas late or delayed clearance of Mf was pre-determined by MHC-related factors. Genetic knock-out of genes for the MHC class-II molecules totally abrogated resistance. Most interestingly, the presence of only I adult female, but not male worms, renders all mice susceptible, irrespective of the genetic background, enabling Mf to circulate for extended periods of time. Such prolonged microfilaraemia was also observed in L. sigmodontis-infected animals challenged with heterologous Mf of Acanthocheilonema viteae. The use of cytokine gene knock-out mice showed that persistence of L. sigmodontis Mf was facilitated by IL-10, but not by IL-4 or IFN-gamma. In conclusion, irrespective of a resistant or susceptible host genetic background, survival of Mf of L. sigmodontis in mice is decisively regulated by the presence of adult female L. sigmodontis which will skew and exploit immune responses to facilitate the survival and persistence of their offspring in the infected host.


Subject(s)
Filariasis/immunology , Filarioidea/immunology , Microfilariae/immunology , Parasitemia/immunology , Animals , Antibodies, Helminth/analysis , Cytokines/biosynthesis , Female , Filariasis/parasitology , Filarioidea/growth & development , Genes, MHC Class II/immunology , Host-Parasite Interactions/immunology , Immunity, Innate/genetics , Immunity, Innate/immunology , Interleukin-10/biosynthesis , Interleukin-10/immunology , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C3H , Mice, Inbred C57BL , Mice, Inbred DBA , Mice, Knockout/genetics , Mice, Knockout/parasitology , Microfilariae/growth & development , Parasitemia/parasitology , Spleen/parasitology
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