Experimental infection of immunomodulated NOD/LtSz-SCID mice as a new model for Plasmodium falciparum erythrocytic stages

The main objective of this study was to determine whether a chemical immunomodulation protocol could reduce the resistance of NOD/LtSz-SCID mice to Plasmodium falciparum infection and provide an improved mouse model for screening the antimalarial activity of new compounds. This model was compared with the presently used immunodeficient Beige/Nude/Xid (BNX) mouse model, using the same protocol, in terms of percentage of infected mice, parasite development, leukocyte response and phagocytosis of P. falciparum infected cells in various organs. Our results show that the combination of the chemical immune modulation protocol with the genetic background of NOD/LtSz-SCID mice results in the development of long-lasting P. falciparum infection in a high percentage of mice. A comparison of the results obtained in the histological study for both mouse models suggests that the higher rate of success in NOD/LtSz-SCID mice could be related to the reduced macrophage recruitment developed in different tissues to remove the parasite from blood.     

Cavitary pneumonia in an AIDS patient caused by an unusual Bordetella bronchiseptica variant producing reduced amounts of pertactin and other major antigens

Although Bordetella bronchiseptica can infect and colonize immunocompromised humans, its role as a primary pathogen in pneumonia and other respiratory processes affecting those patients remains controversial. A case of cavitary pneumonia caused by B. bronchiseptica in an AIDS patient is presented, and the basis of the seemingly enhanced pathogenic potential of this isolate (designated 814) is investigated. B. bronchiseptica was the only microorganism recovered from sputum, bronchoalveolar lavage fluid, and samples taken through the protected brush catheter. Unlike previous work reporting the involvement of B. bronchiseptica in cases of pneumonia, antibiotic treatment selected on the basis of in vitro antibacterial activity resulted in clearance of the infection and resolution of the pulmonary infiltrate. Although isolate 814 produced reduced amounts of several major antigens including at least one Bvg-activated factor (pertactin), the molecular basis of this deficiency was found to be BvgAS independent since the defect persisted after the bvgAS locus of isolate 814 was replaced with a wild-type bvgAS allele. Despite its prominent phenotype, isolate 814 displayed only a modest yet a significant deficiency in its ability to colonize the respiratory tracts of immunocompetent rats at an early time point. Interestingly, the antibody response elicited by isolate 814 in these animals was almost undetectable. We propose that isolate 814 may be more virulent in immunocompromised patients due, at least in part, to its innate ability to produce low amounts of immunogenic factors which may be required at only normal levels for the interaction of this pathogen with its immunocompetent natural hosts.     

Inflammatory Responses in Blood Samples of Human Immunodeficiency Virus-Infected Patients with Pulmonary Infections

We analyzed the characteristics of the inflammatory response occurring in blood during pulmonary infections in human immunodeficiency virus (HIV)-infected patients. A prospective study of consecutive hospital admissions of HIV-infected patients with new-onset radiologic pulmonary infiltrates was carried out in a tertiary university hospital from April 1998 to May 2001. Plasma cyclic AMP receptor protein (CRP), interleukin 1β (IL-1β), IL-6, IL-8, IL-10, and tumor necrosis factor alpha (TNF-α) levels were determined at the time of admission and 4, 5, and 6 days later. Patients were included in a protocol addressed to study etiology and outcome of disease. A total of 249 episodes of infection were included, with the main diagnoses being bacterial pneumonia (BP) (118 episodes), Pneumocystis carinii pneumonia (PCP) (41 episodes), and mycobacteriosis (36 episodes). For these three patient groups, at the time of admission the median CRP and cytokine levels were as follows: CRP, 10.2, 3.8 and 5 mg/dl, respectively (P = 0.0001); IL-8, 19, 3, and 2.9 pg/ml (P = 0.045); and TNF-α, 46.4, 44, and 75 pg/ml, respectively (P = 0.029). There were no significant differences in levels of IL-1β, IL-6, or IL-10 among the patient groups. A total of 23 patients died. At the time of admission, HIV-infected patients with BP had higher plasma CRP and IL-8 levels than did PCP and mycobacteriosis patients. TNF-α levels were higher in patients with mycobacteriosis. An elevated IL-8 level (>61 pg/ml) at the time of admission was an independent factor associated with higher mortality (odds ratio, 12; 95% confidence interval, 1.2 to 235.5).     

Molecular diagnosis of infective endocarditis by PCR amplification and direct sequencing of DNA from valve tissue

We used broad-range eubacterial PCR amplification followed by direct sequencing to identify microbial pathogens in heart valve material from 29 patients with histologically confirmed infective endocarditis and 23 patients free of infective endocarditis. Microorganisms cultured by conventional techniques matched those identified by PCR in 21 cases. PCR alone identified the causative agent in three cases (Streptococcus bovis, Staphylococcus cohnii, and Coxiella burnetii), allowing better patient management. PCR corrected the initial bacteriological diagnosis in three cases (Streptococcus bovis, Streptococcus mutans, and Bartonella henselae). Among the 29 cases of histologically confirmed infective endocarditis, PCR findings were positive in 27 cases and were consistent with the bacterial morphology seen at Gram staining (26 cases) or with the results obtained by immunohistologic analysis with an anti-C. burnetii monoclonal antibody (one case). In two other cases of histologically confirmed infective endocarditis, PCR remained negative in a blood culture-negative case for which no bacteria were seen at histological analysis and in one case with visualization of cocci and blood cultures positive for Enterococcus faecalis. Ten clinical diagnoses of possible infective endocarditis were ruled out by histopathological analysis of the valves and subsequently by PCR. PCR was negative in 13 of the 14 patients in whom infective endocarditis was rejected on clinical grounds; the other patient was found to have Coxiella burnetii infective endocarditis on the basis of PCR and histopathological analysis and was subsequently included in the group of 29 definite cases. In total, PCR contributed to the diagnosis and management of infective endocarditis in 6 of 29 (20%) cases.     

Association of interleukin 1 gene family polymorphisms with duodenal ulcer disease

Cytokine genes taking part in the immunological response to Helicobacter pylori infection are good candidates to study for genetic predisposition to duodenal ulcer disease (DU). Among cytokines, interleukin (IL)-1beta and its natural specific inhibitor, the interleukin-1 receptor antagonist, are cytokines that play a key role in regulating gastric acid secretion and modulating the immune response in the gastrointestinal mucosa. We aimed to investigate whether polymorphisms in the IL-1B and IL-1RN genes are involved in the susceptibility to duodenal ulcer. DNA from 131 unrelated Spanish Caucasian patients with DU and 105 ethnically matched healthy controls was typed for the IL-1B-511, IL-1B-31, and IL-1B + 3954 gene polymorphisms, and the VNTR polymorphism in intron 2 of the IL-1RN gene by polymerase chain reaction (PCR)-based methods and TaqMan assays. H. pylori status and non-steroidal anti-inflammatory drugs (NSAIDs) use was determined in all patients and controls. Logistic regression analysis identified H. pylori infection (OR: 9.74; 95%CI = 3.53-26.89) and NSAIDs use (OR: 8.82; 95%CI = 3.51-22.17) as independent risk factors for DU. In addition, the simultaneous carriage of IL-1RN*2, IL-1B-511*C, IL-1B-31*T and IL-1B + 3954*C alleles was a genetic risk factor for DU in patients with H. pylori infection (OR: 3.22; 95%CI = 1.09-9.47). No significant differences in IL-1RN and IL-1B genotypes were found when patients were categorized according to gender, age of onset, smoking habit, NSAIDs use, type of complication and positive family history. Our results provide further evidence that host genetic factors play a key role in the pathogenesis of duodenal ulcer.     

Malaria vectors in the Bioko Island (Equatorial Guinea): estimation of vector dynamics and transmission intensities

The current study was performed on the Bioko Island (Equatorial Guinea) with the aim of establishing a rapid assessment technique for mapping malaria risk and measuring vector densities. Human bait collection, tent traps, light traps, indoor resting collection, and window exit traps were used to collect Anopheles gambiae s.s. and Anopheles funestus, the two anopheline species involved in malaria transmission in this island. Capture data were used to compare differences in the behavior and vectorial capacity of An. gambiae s.s. and An. funestus. Differences in the two species of mosquitoes were found in relation to the season and trapping methods used. Entomological inoculation rates (EIR) for Plasmodium falciparum were calculated using a polymerase chain reaction (PCR) test with individual anopheline mosquitoes from human bait collections in two villages during the dry and rainy seasons. P. falciparum sporozoites were detected from both dissected heads/thorax and abdomens of both species.     

Groups I,II and III extracellular phospholipases A2: Selective inhibition of group II enzymes by indomethacin but not other NSAIDs

The three types (groups I, II and III) of stable extracellular 14 kDa phospholipase A₂ enzymes differ in their primary amino acid sequences and their properties. It may thus be possible to design low-molecular weight inhibitors targeted to the secretory form of mammalian PLA₂. this enzyme has been implicated in inflammatory disorders. We have studied the inhibition of four distinct PLA₂ enzymes by a range of NSAIDs, using³H-oleate release from prelabelled membranes ofE. coli for assay. The enzymes used were cobra venom PLA₂ (Naja naja, a group I enzyme), bee venom PLA₂ (Apis mellifera, group III), recombinant human synovial PLA₂ (group II) and rat peritoneal PLA₂ (group II). Under the conditions of the³H-oleateE. coli assay, 1 mM concentrations of aspirin, sodium salicylate, paracetamol (acetaminophen), oxphenbutazone, ibuprofen, flurbiprofen and nabumetone failed to inhibit significantly any of the four enzymes. However, indomethacin inhibited all four enzymes, although effects were greatest on the two group II enzymes (rat peritoneal and human synovial PLA₂). Approximate IC₅₀ values were 28 and 35 M, respectively. Inhibition by indomethacin was not time dependent and was greater at micromolar rather than millimolar levels of calcium. We conclude that indomethacin but not the other tested classes of NSAID inhibits the group II PLA₂ enzyme in a selective manner and suggest that this may be relevant both to its clinical spectrum and to the design of novel pharmaceutical leads.     

Self-reported comfort in athletic training of gender-specific and non-gender-specific injuries and issues

Context: To assist athletes in maintaining optimal health, athletic trainers must work with athletes of both sexes.Objective: To examine athletic trainers'' comfort levels in providing care for gender-specific and non-gender-specific injuries and issues.Design: We mailed 235 Gender Comfort in Athletic Training Questionnaires to program directors, who were asked to distribute and collect them.Setting: We randomly selected 21 athletic training education program directors and invited them by e-mail to participate in the study. Fourteen program directors representing the 10 National Athletic Trainers'' Association districts agreed to participate.Patients or Other Participants: A total of 192 participants returned completed questionnaires, for a response rate of 82% (103 women, 89 men; 101 senior athletic training students, 91 certified athletic trainers).Main Outcome Measure(s): The questionnaire consisted of 17 injuries and issues common to both female and male athlete scenarios. Three gender-specific items were added to each scenario. Responses were scored on a 5-point scale anchored by 1 (very uncomfortable) and 5 (very comfortable). Participants were asked to indicate the reason for any degree of discomfort. Internal consistency, determined by the Cronbach alpha, was .92 for the female athlete scenario and .93 for the male athlete scenario.Results: We found significant differences between women and men certified athletic trainers for the female and male athlete scenarios. Overall, women were more comfortable caring for female injuries and issues, whereas men were more comfortable caring for male injuries and issues. Certified athletic trainers reported more comfort overall than athletic training students. The most common underlying reason reported for discomfort in caring for female and male injuries and issues was experience level.Conclusions: Athletic training education programs should provide early and more deliberate experiences with injuries and issues of a more intimate nature, including those that are gender specific and non-gender specific. These experiences may increase athletic trainers'' level of comfort in providing care to athletes of the opposite sex.