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1.
Epidemiol Infect ; 141(6): 1207-13, 2013 Jun.
Article in English | MEDLINE | ID: mdl-22906362

ABSTRACT

Surgical site infection (SSI) after vascular surgery is a serious complication increasing morbidity, mortality, and costs for healthcare systems. A 4-year retrospective cohort study was performed in a university hospital with patients who had undergone arterial vascular surgery below the aortic arch. Investigated variables included demographics and clinical data. Forty-four of 756 patients experienced SSI, 29 of which were superficial, five were deep, and 10 had organ/space infections. Coagulase-negative staphylococci (22%), enterococci (20%), and Staphylococcus aureus (18%) were the most common pathogens. Independent risk factors for SSIs were femoral grafting [odds ratio (OR) 6·7], peripheral atherosclerotic disease, Fontaine stages III-IV (OR 4·1), postoperative drainage >5 days (OR 3·6), immunosuppression (OR 2·8), duration of operation >214 min (OR 2·8), and body mass index >29 (OR 2·6). The application of perioperative antibiotic prophylaxis was an independent protective factor (OR 0·2). Patients with certain risk factors for SSIs warrant special attention for infection prevention.


Subject(s)
Cross Infection/etiology , Hospitals, University/statistics & numerical data , Surgical Wound Infection/etiology , Vascular Surgical Procedures/adverse effects , Aged , Cross Infection/epidemiology , Female , Femoral Artery/surgery , Humans , Male , Multivariate Analysis , Retrospective Studies , Risk Factors , Statistics, Nonparametric , Surgical Wound Infection/epidemiology , Surgical Wound Infection/microbiology , Vascular Grafting/adverse effects , Vascular Grafting/statistics & numerical data , Vascular Surgical Procedures/statistics & numerical data
2.
Eur J Med Res ; 15(11): 504-6, 2010 Nov 25.
Article in English | MEDLINE | ID: mdl-21159575

ABSTRACT

Cryptococcus neoformans is the most common cause of life threatening meningoencephalitis in HIV-infected patients. Diagnosis is based on tests for cryptoccocal antigen in serum and cerebrospinal fluid, and on culture of the organism. We present a case of AIDS-related cryptococcal meningoencephalitis unresponsive to antifungal combination therapy, despite of evidence of fungal susceptibility in vitro. Significant decreases in cryptococcal antigen titers in serum and cerebrospinal fluid did not correlate with progress in disease and fatal outcome.


Subject(s)
AIDS-Related Opportunistic Infections/drug therapy , Antifungal Agents/therapeutic use , Meningitis, Cryptococcal/drug therapy , AIDS-Related Opportunistic Infections/cerebrospinal fluid , Adult , Fatal Outcome , Humans , Male , Meningitis, Cryptococcal/cerebrospinal fluid
3.
Z Gastroenterol ; 48(1): 33-7, 2010 Jan.
Article in English | MEDLINE | ID: mdl-20072994

ABSTRACT

A 21-year-old male presented at the emergency room with jaundice, itching, dry cough, malaise and weight loss of 10 kg during the preceding four weeks. Eighteen months earlier, the patient had suffered an automobile accident leading to polytrauma. Serological markers for viral or other causes of hepatitis were absent. For suspected secondary sclerosing cholangitis, ultrasound and ERCP were performed but failed to reveal pathological findings. A liver biopsy showed cholestatic liver disease without signs of portal field-associated hepatitis. Hepato-biliary scintigraphy demonstrated hepatocellular dysfunction. The patient finally mentioned his guinea pig farm with around 50 animals, 20 of which had recently died for unknown reasons. The patient and three of his guinea pigs were subsequently tested for serological evidence of leptospirosis. IgG and IgM antibodies reacting with Leptospira interrogans were detected in the patient's serum, and all 3 guinea pigs were serologically positive for serovar Bratislava. Bacterial culture was not successful, and also PCR tests remained negative. The clinical symptoms quickly resolved after the initiation of antibiotic therapy with amoxicillin.


Subject(s)
Agricultural Workers' Diseases/diagnosis , Animal Husbandry , Jaundice, Obstructive/etiology , Leptospira interrogans , Leptospirosis/diagnosis , Leptospirosis/veterinary , Rodent Diseases/diagnosis , Zoonoses/transmission , Agricultural Workers' Diseases/microbiology , Animals , Diagnosis, Differential , Guinea Pigs , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Jaundice, Obstructive/diagnosis , Jaundice, Obstructive/microbiology , Leptospira interrogans/immunology , Male , Microbiology , Rodent Diseases/microbiology , Rodent Diseases/transmission , Young Adult , Zoonoses/microbiology
4.
J Hosp Infect ; 102(3): 325-331, 2019 Jul.
Article in English | MEDLINE | ID: mdl-30716339

ABSTRACT

BACKGROUND: Preterm infants and critically ill neonates are predisposed to nosocomial infections as sepsis. Moreover, these infants acquire commensal bacteria, which might become potentially harmful. On-ward transmission of these bacteria can cause outbreaks. AIM: To report the findings of a prospective surveillance of bacterial colonization and primary sepsis in preterm infants and neonates. METHODS: The results of the surveillance of bacterial colonization of the gut and the respiratory tract, targeting meticillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE) and Gram-negative bacteria from November 2016 to March 2018 were analysed. Bacterial colonization was compared to surveillance of sepsis. FINDINGS: Six-hundred and seventy-one patients were admitted and 87.0 % (N=584) of the patients were screened; 48.3% (N=282) of the patients screened were colonized with at least one of the bacteria included in the screening; 26.2% of them (N=74) had multi-drug-resistant strains. A total of 534 bacterial isolates were found. The most frequently found species were Escherichia coli, Enterobacter cloacae, Klebsiella oxytoca and Klebsiella pneumoniae. Three MRSA but no VRE were detected. The surveillance detected a K. pneumoniae cluster involving nine patients. There were 23 blood-culture-confirmed sepsis episodes; 60.9% (N=14) were caused by staphylococci. Gram-negative bacteria (one Klebsiella aerogenes and two E. cloacae) caused three sepsis episodes which were preceded by colonization with the respective isolates. CONCLUSIONS: Surveillance of colonization provided a comprehensive overview of species and antibiotic resistance patterns. It allowed early detection of a colonization cluster. Knowledge of colonization and surveillance of sepsis is useful for guiding infection control measures and antibiotic treatment.


Subject(s)
Bacterial Infections/epidemiology , Carrier State/epidemiology , Epidemiological Monitoring , Intensive Care Units, Neonatal , Sepsis/epidemiology , Bacterial Infections/microbiology , Carrier State/microbiology , Disease Transmission, Infectious , Gastrointestinal Tract/microbiology , Gram-Negative Bacteria/isolation & purification , Humans , Infant , Infant, Newborn , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Prospective Studies , Respiratory System/microbiology , Sepsis/microbiology , Tertiary Care Centers , Vancomycin-Resistant Enterococci/isolation & purification
5.
Stud Health Technol Inform ; 258: 245-246, 2019.
Article in English | MEDLINE | ID: mdl-30942759

ABSTRACT

Within the HiGHmed Project there are three medical use cases. The use cases include the scopes cardiology, oncology and infection. They serve to specify the requirements for the development and implementation of a local and federated platform, with the result that data from medical care and research should be retrievable, reusable and interchangeable. The Use Case Infection Control aims to establish an early detection of transmission events as well as clusters and outbreaks of various pathogens. Therefore the use case wants to establish the smart infection control system (SmICS).


Subject(s)
Cross Infection , Infection Control , Data Analysis , Disease Outbreaks , Early Diagnosis , Humans
6.
J Hosp Infect ; 98(2): 127-133, 2018 Feb.
Article in English | MEDLINE | ID: mdl-28756167

ABSTRACT

BACKGROUND: Meticillin-resistant Staphylococcus aureus (MRSA) is a frequently encountered pathogen in burn units. Burn patients are especially susceptible to MRSA acquisition and MRSA spread may cause outbreaks in burn units. AIM: To report the characteristics and successful control of an MRSA outbreak and to demonstrate a multimodal infection control concept. METHODS: In addition to a pre-existing infection control concept, several control measures were implemented including weekly prevalence screenings for MRSA, reinforcement of disinfection, restriction of admissions, and short-term unit closure. Epidemiologic investigation and environmental examinations were performed. The outbreak isolates were analysed by pulsed-field gel electrophoresis and spa-typing. A PubMed search was conducted, focusing on MRSA outbreaks in burn units. FINDINGS: This outbreak of hospital-acquired MRSA affected eight patients during a seven-month period, yielding an attack rate of 8%. Epidemiologic and environmental examinations suggested patient-to-patient transmission, which was confirmed by molecular analysis of bacterial isolates revealing a monoclonal pattern. In accordance with findings from other outbreaks in burn units, the implemented measures including patient screening and temporary unit closure resulted in successful control of the outbreak. CONCLUSION: A comprehensive concept is required to control the spread of all multidrug-resistant micro-organisms including MRSA on a burn unit. Where patients colonized or infected with MRSA appear to be the main reservoir, transfer of these patients to other units, or temporary closure of the unit, accompanied by intensive cleaning are very effective measures to stop transmission events.


Subject(s)
Burns/complications , Cross Infection/prevention & control , Disease Outbreaks , Infection Control/methods , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Staphylococcal Infections/prevention & control , Wound Infection/prevention & control , Cross Infection/epidemiology , Cross Infection/microbiology , Disease Transmission, Infectious/prevention & control , Humans , Intensive Care Units , Methicillin-Resistant Staphylococcus aureus/classification , Methicillin-Resistant Staphylococcus aureus/genetics , Molecular Epidemiology , Molecular Typing , Staphylococcal Infections/epidemiology , Staphylococcal Infections/microbiology , Wound Infection/epidemiology , Wound Infection/microbiology
7.
Ann Burns Fire Disasters ; 31(3): 189-193, 2018 Sep 30.
Article in English | MEDLINE | ID: mdl-30863251

ABSTRACT

To systematically evaluate which infection control measures are in place in burn units, we conducted an online survey among 43 German-speaking burn units. The 29 units that responded and agreed to publication represented more than 125 patient beds. All units were located in advanced care hospitals. A total of 14 units provided single rooms only, and 22 units had a nurse-to-patient ratio of at least 1:2. Infection control practices included pre-emptive barrier precautions (29 units), the use of sterile filters for tap water supply (29 units), and an antibiotic stewardship program (24 units). Microbial screening of the patients on admission (23 units), regular prevalence screening (26 units) and surveillance of nosocomial infections (21 units) were also widely used. The high reply rate to the survey indicates the special relevance of infection control for burn units. Our survey shows that great efforts and several measures are being undertaken to address infection control challenges in burn patient care, but it also underlines the need for increased interdisciplinary infection control and antibiotic stewardship activities.


Afin d'évaluer les mesures préventives des infections déployées, nous avons réalisé une enquête en ligne auprès de 43 Centres de Traitement des Brûlés germanophones. Les 29 CTB ayant répondu (et accepté la publication) représentent 125 lits. Tous les CTB étaient situés dans des hôpitaux de référence. Quatorze CTB n'avaient que des chambres seules, 22 avaient un ratio infirmière/patient de1/2. Les mesures préventives comprenaient les précautions barrière (29), des filtres aux points d'eau (29), un programme d'évaluation de l'antibiothérapie (24). La cartographie bactérienne à l'entrée (23), la surveillance de la prévalence des infections (26) et des infections nosocomiales (21) étaient aussi régulièrement déployées. Le taux de réponse élevé pour ce type d'étude montre l'intérêt porté à la prévention des infections en CTB. Cette étude montre que les CTB portent une attention particulière à la prévention et à la surveillance des infections. Elle démontre aussi l'intérêt d'une approche multidisciplinaire et de la mise en place de programmes d'évaluation de l'antibiothérapie.

8.
J Invest Dermatol ; 104(1): 58-61, 1995 Jan.
Article in English | MEDLINE | ID: mdl-7528246

ABSTRACT

The immortalized human keratinocyte cell line HaCaT was used to assess the effect of interferon-gamma (IFN-gamma) on expression of keratin K17. Both IFN-gamma and K17 have been implicated in the pathophysiology of psoriasis. Western and quantitative enzyme-linked immunosorbent assay analyses demonstrated increasing induction of K17 protein by 48 h exposure to IFN-gamma at concentrations of 10, 50, and 250 U/ml. At 50 U/ml IFN-gamma, immunohistochemical analysis revealed numerous K17-positive foci, whereas in situ hybridization demonstrated K17 message in the majority of cells. In addition, at low (5 U/ml) concentrations of IFN-gamma, cell proliferation and protein synthesis decreased, as determined by 3H-thymidine labeling and 14C-amino acid uptake. These data suggest that aberrant K17 expression observed in psoriatic lesions may be a consequence of IFN-gamma overexpression, and that the HaCaT cell line may be a useful in vitro model system to elucidate the underlying mechanisms.


Subject(s)
Interferon-gamma/pharmacology , Keratinocytes/chemistry , Keratins/physiology , Antigens, Differentiation/analysis , Blotting, Western , Cell Line , Enzyme-Linked Immunosorbent Assay , Humans , Keratins/drug effects , Keratins/genetics , Psoriasis/diagnosis , RNA, Messenger/analysis , Up-Regulation
9.
FEBS Lett ; 300(2): 162-6, 1992 Mar 30.
Article in English | MEDLINE | ID: mdl-1373391

ABSTRACT

Interferon gamma induces expression of a protein termed IFP 53 according to its molecular weight of 53 kDa. IFP 53 shows significant sequence homology to rabbit peptide chain release factor as well as to bovine tryptophanyl-tRNA synthetase. IFP 53 has been shown to possess release factor activity for the UGA stop codon. We demonstrate here, by using a recombinant IFP 53 fusion protein, that IFP 53 tryptophanylates tRNA. These data indicate that IFP 53 is a protein with two activities: peptide chain termination and aminoacylation.


Subject(s)
Tryptophan-tRNA Ligase/physiology , Acylation , Amino Acid Sequence , Blotting, Western , Cloning, Molecular , Electrophoresis, Polyacrylamide Gel , Enzyme Induction , HeLa Cells , Humans , Interferons/pharmacology , Molecular Sequence Data , Recombinant Fusion Proteins , Sequence Homology, Nucleic Acid , Tryptophan-tRNA Ligase/biosynthesis
10.
Arch Pediatr ; 21(1): 108-12, 2014 Jan.
Article in French | MEDLINE | ID: mdl-24309201

ABSTRACT

Attention Deficit Hyperactivity Disorder (ADHD) is one of the most common of the pediatric neuropsychiatric disorders. Methylphenidate is an important element of therapeutic strategies for ADHD. Clinicians are interested in the safety of methylphenidate. Because this drug raises heart rate and blood pressure, concerns have been raised about its cardiovascular safety. Concerns were based on case reports of sudden cardiac death in methylphenidate users, plausible pharmacological pathways involving well-established stimulant effects on heart rate and blood pressure. Until recently, data were limited to a number of observational studies too small to examine serious cardiac events. In the past two years, large retrospective, population-based cohort studies were performed. These studies did not show any evidence that methylphenidate was associated with an increase in risk of myocardial infarction, sudden cardiac death, or stroke. Treatment of children with methylphenidate is not significantly associated with an increase in the short term or mid-term risk of severe cardiac events. For many, available data now will be seen as reassuring. But gaps persist in the methodical and comprehensive assessments of the safety of methylphenidate. Analyses cannot be generalized to children with long-term use of stimulants. Furthermore, long-term effects of slight increases in heart rate or blood pressure are unknown. Stimulant administration continues to have a detectable adrenergic effect even after years of treatment. In the MTA study, greater cumulative stimulant exposure was associated with a higher heart rate at years 3 and 8. Although less severe, such adverse cardiac events are nonetheless alarming to patients. This adrenergic effect may have clinical implications, especially for individual patients with underlying heart abnormalities and it deserves further investigation. More research is necessary to optimize a safe use of methylphenidate regarding its cardiovascular effects. In light of the controversies surrounding the increase in the number of children being diagnosed with ADHD, the broad use of methylphenidate in these patients, and cardiovascular concerns about it, this article addresses topics of clinical significance. For ease of use by practitioners, the article summarizes the guidelines stated by the European Medicines Agency over the appropriate pretreatment evaluation and cardiovascular assessment. It advocates a thorough history and physical examination before initiating methylphenidate to treat patients with ADHD, with an emphasis on the identification of risk factors for sudden death. A cardiac sub-specialist consultation is mandatory in case of history or physical examination findings. In other cases, an electrocardiographic screening is recommended in order to check out previously unrecognized heart disease.


Subject(s)
Attention Deficit Disorder with Hyperactivity/drug therapy , Central Nervous System Stimulants/adverse effects , Central Nervous System Stimulants/therapeutic use , Death, Sudden, Cardiac/etiology , Methylphenidate/adverse effects , Methylphenidate/therapeutic use , Myocardial Infarction/chemically induced , Stroke/chemically induced , Blood Pressure/drug effects , Child , Cooperative Behavior , Drug Monitoring , Guideline Adherence , Heart Rate/drug effects , Humans , Interdisciplinary Communication , Long-Term Care , Referral and Consultation , Risk Factors
11.
Forensic Sci Int ; 226(1-3): 266-72, 2013 Mar 10.
Article in English | MEDLINE | ID: mdl-23434379

ABSTRACT

Procalcitonin is regarded as a valuable marker for sepsis in living persons and even in post-mortem investigations. At the Institute of Legal Medicine, 25 autopsy cases with suspected bacterial infectious diseases or sepsis were examined using the semi-quantitative PCT-Q(®)-test (B.R.A.H.M.S., Germany) in 2010 and 2011. As controls, 75 cadavers were used for which there was no suspicion of a bacterial infectious disease or sepsis. Femoral blood was cultured from the cases and from controls, and samples from the brain, heart, lungs, liver, spleen and kidneys were examined histologically for findings seen in sepsis. Twelve cases in the sepsis/infectious disease group (48%) were classifiable as sepsis following synopsis of PCT levels, autopsy results, and histopathological and microbiological findings. This study shows that the semi-quantitative PCT-Q(®)-test is a useful supplementary marker in routine autopsy investigations, capable of classifying death as due to sepsis.


Subject(s)
Calcitonin/blood , Protein Precursors/blood , Sepsis/diagnosis , Adolescent , Adult , Aged , Aged, 80 and over , Biomarkers/blood , Brain/pathology , Calcitonin Gene-Related Peptide , Case-Control Studies , Female , Forensic Pathology , Granulocytes/pathology , Humans , Kidney/pathology , Leukocytes/pathology , Liver/pathology , Lung/pathology , Male , Middle Aged , Myocardium/pathology , Prospective Studies , Spleen/pathology , Young Adult
12.
Arch Pediatr ; 18(7): 831-4, 2011 Jul.
Article in French | MEDLINE | ID: mdl-21652189

ABSTRACT

Attention deficit hyperactivity disorder (ADHD) is among the most common psychiatric disorders of childhood. Although some symptoms of ADHD may diminish this does not mean that functioning is unimpaired in adults. Follow-up studies of children with ADHD show that it persists into adulthood in the majority of cases. Due to genetic factors high rates of ADHD exist among the parents of children with ADHD. More females are identified and become diagnosed in adulthood. There is a greater persistence of inattentive than of hyperactive/impulsive childhood symptoms of ADHD in adulthood. Some experts conceptualise ADHD as primarily a deficit of executive functions impairing planification, time perception and emotional regulation. ADHD often presents as a lifelong condition in adults associated with a range of clinical and psychosocial impairments. Young adults with comorbid antisocial or substance use disorder in adolescence are at significantly increased risk for criminal behaviors. Some predictors of the outcome have been identified such as childhood symptom profile and severity, comorbidity and childhood family adversities.


Subject(s)
Attention Deficit Disorder with Hyperactivity/diagnosis , Adolescent , Adult , Age Factors , Antisocial Personality Disorder/diagnosis , Antisocial Personality Disorder/epidemiology , Antisocial Personality Disorder/psychology , Attention Deficit Disorder with Hyperactivity/epidemiology , Attention Deficit Disorder with Hyperactivity/psychology , Attention Deficit Disorder with Hyperactivity/therapy , Child , Child, Preschool , Comorbidity , Crime/psychology , Crime/statistics & numerical data , Cross-Sectional Studies , Executive Function , Female , Follow-Up Studies , Humans , Male , Neuropsychological Tests , Prognosis , Sex Factors , Social Adjustment , Substance-Related Disorders/diagnosis , Substance-Related Disorders/epidemiology , Substance-Related Disorders/psychology , Young Adult
13.
Dtsch Med Wochenschr ; 135(23): 1179-81, 2010 Jun.
Article in German | MEDLINE | ID: mdl-20514598

ABSTRACT

HISTORY: A 70-year-old woman who had for five years been treated with tumour necrosis factor (TNF)-a-inhibitors for rheumatoid arthritis was admitted because of treatment-refractory oral ulcerations and persisting considerable soft-tissue swelling over the left maxilla. INVESTIGATIONS AND DIAGNOSIS: Multiple mucosal biopsies from the left maxillary sinus revealed necrotizing granulomatous inflammation suspicious of mycobacterial infection. This was subsequently confirmed in concurrent microbiological cultures and ultimately identified as Mycobacterium bovis. This species of the mycobacterium tuberculosis complex has in recent times rarely been seen in clinical practice in Germany. On further questioning the patient reported that she had been treated for "lung disease" as a schoolgirl. TREATMENT AND COURSE: The patient was isolated and quadruple therapy with isoniazide (INH), rifampin (RMP), ethambutol (EMB) and pyrazinamide (PZA) was initiated. Rapid improvement of her condition occurred within two weeks. When microbiological sub-typing using 16s-RNA sequencing had confirmed M. bovis, PZA was replaced by moxifloxacin. CONCLUSION: When investigating the cause of treatment-refractory infections and ulcerations, particularly among immunosuppressed patients, consideration should always be given to mycobacterial infections. Detailed and targeted history-taking is vital.


Subject(s)
Antibodies, Monoclonal/adverse effects , Antirheumatic Agents/adverse effects , Arthritis, Rheumatoid/drug therapy , Methotrexate/adverse effects , Mycobacterium bovis , Opportunistic Infections/chemically induced , Tuberculosis, Oral/chemically induced , Adalimumab , Aged , Antibodies, Monoclonal/therapeutic use , Antibodies, Monoclonal, Humanized , Antirheumatic Agents/therapeutic use , Antitubercular Agents/therapeutic use , Diagnosis, Differential , Drug Therapy, Combination , Female , Humans , Methotrexate/therapeutic use , Mouth Mucosa/pathology , Opportunistic Infections/diagnosis , Opportunistic Infections/drug therapy , Opportunistic Infections/pathology , Recurrence , Tuberculosis, Oral/diagnosis , Tuberculosis, Oral/drug therapy , Tuberculosis, Oral/pathology
14.
J Hosp Infect ; 76(4): 300-3, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20951471

ABSTRACT

Nosocomial infections with meticillin-resistant Staphylococcus aureus (MRSA) lead to increased health and economic costs. The purpose of this study was to determine costs for nosocomial MRSA pneumonia compared with meticillin-susceptible S. aureus (MSSA) pneumonia. A case-control study was conducted with patients who acquired nosocomial pneumonia with either MRSA or MSSA between January 2005 and December 2007. Patients were matched for age, severity of underlying disease, stay on intensive care units and non-intensive care units, admission and discharge within the same year, and in-hospital stay at least as long as that of cases before MRSA pneumonia. Our analysis includes 82 patients (41 cases, 41 controls). The overall costs for patients with nosocomial MRSA pneumonia were significantly higher than for patients with MSSA pneumonia (€60,684 vs €38,731; P=0.01). The attributable costs for MRSA pneumonia per patient were €17,282 (P<0.001). The financial loss was higher for patients with MRSA pneumonia than for patients with MSSA pneumonia (€11,704 vs €2,662; P=0.002). More cases died than controls while in the hospital (13 vs 1 death, P<0.001). Hospital personnel should be aware of the attributable costs of MRSA pneumonia, and should implement control measures to prevent MRSA transmission.


Subject(s)
Cross Infection/economics , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Pneumonia, Staphylococcal/economics , Aged , Case-Control Studies , Female , Health Care Costs , Humans , Male , Middle Aged
19.
J Pathol ; 210(3): 298-305, 2006 Nov.
Article in English | MEDLINE | ID: mdl-17001607

ABSTRACT

It is often assumed that Mycobacterium tuberculosis (Mtb)-induced granulomatous lesions, particularly those undergoing central caseation, are anoxic, and that the survival of Mtb in these lesions requires the integrity of its non-oxidative respiratory pathways. Using the hypoxia marker pimonidazole, we now provide immunohistochemical evidence that in the most frequently used animal model system of inbred mice Mtb-induced granulomas, even after more than one year of aerogenic infection, are not severely hypoxic. In contrast, chronic aerosol infection with M. avium strain TMC724 was associated with hypoxia surrounding necrotizing granuloma centres. Direct measurements of oxygen tension with a flexible microelectrode in mouse lungs chronically infected with Mtb disclosed a wide range of oxygen partial pressures in different parts of the lungs which, however, rarely approached the anoxic conditions consistently found in necrotizing tumours. We further show that an Mtb mutant, defective in nitrate reductase (narG) necessary for survival under anaerobic conditions in vitro, can persist in the lungs of chronically infected mice to a similar extent as wild-type Mtb. These findings have important implications for the use of the mouse model of Mtb infection in developing eradication chemotherapy and for evaluating putative mechanisms of chronic persistence and latency of Mtb.


Subject(s)
Granuloma/metabolism , Hypoxia/metabolism , Tuberculosis, Pulmonary/metabolism , Animals , Biomarkers/analysis , Disease Models, Animal , Electrodes , Female , Granuloma/complications , Granuloma/pathology , Hypoxia/complications , Hypoxia/pathology , Immunohistochemistry/methods , Lung/metabolism , Lung/microbiology , Lung/pathology , Mice , Mice, Inbred C57BL , Mutation , Mycobacterium tuberculosis/genetics , Necrosis , Nitrates/metabolism , Nitroimidazoles/analysis , Oxygen/physiology , Time Factors , Tuberculosis, Pulmonary/complications , Tuberculosis, Pulmonary/pathology
20.
Electroencephalogr Clin Neurophysiol ; 108(5): 472-81, 1998 Sep.
Article in English | MEDLINE | ID: mdl-9780017

ABSTRACT

The P3(00) event-related potentials (ERPs) elicited by visual stimuli in two visual tasks were assessed in depressed patients (12 patients with major depression and 11 patients with bipolar disorder) and compared with those of 20 age-matched normal controls. At remission, the ERPs from 18 of the depressed patients were again recorded. The visual oddball (VO) paradigm presented both target and standard visual stimuli and the simple visual (SV) paradigm presented a target but no standard visual stimulus. Subjects performed the VO task significantly less accurately than the SV task, as reflected by the behavioral measures (reaction-time and task accuracy). Depressed patients of the bipolar group showed longer P3 peak latency for the VO task and no change in P3 amplitude. No significant differences were found in any other ERP component between the groups. During remission, slowing RTs and reduced P3 peak latencies were observed for both major depression and bipolar disorder groups. Thus, the P3 ERP may be an index of the contribution of the slowed central processing to psychomotor retardation in clinically homogenous samples of depressive patients performing an appropriately demanding task.


Subject(s)
Bipolar Disorder/physiopathology , Cognition Disorders/physiopathology , Depression/physiopathology , Event-Related Potentials, P300/physiology , Adult , Female , Humans , Male , Middle Aged , Photic Stimulation , Psychomotor Disorders/physiopathology , Psychomotor Performance , Remission, Spontaneous
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