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Inhibition of Hippocampal Regeneration by Adjuvant Dexamethasone in Experimental Infant Rat Pneumococcal Meningitis. Antimicrob Agents Chemother 2016; 60:1841-6. [PMID: 26824948 DOI: 10.1128/aac.02429-15] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 01/02/2016] [Indexed: 12/31/2022] Open
Abstract
Pneumococcal meningitis (PM) causes neurological sequelae in up to half of surviving patients. Neuronal damage associated with poor outcome is largely mediated by the inflammatory host response. Dexamethasone (DXM) is used as an adjuvant therapy in adult PM, but its efficacy in the treatment of pneumococcal meningitis in children is controversially discussed. While DXM has previously been shown to enhance hippocampal apoptosis in experimental PM, its impact on hippocampal cell proliferation is not known. This study investigated the impact of DXM on hippocampal proliferation in infant rat PM. Eleven-day-old nursing Wistar rats (n = 90) were intracisternally infected with Streptococcus pneumoniae to induce experimental meningitis. Treatment with DXM or vehicle was started 18 h after infection, concomitantly with antibiotics (ceftriaxone 100 mg/kg of body weight twice a day [b.i.d.]). Clinical parameters were monitored, and the amount of cells with proliferating activity was assessed using in vivo incorporation of bromodeoxyuridine (BrdU) and an in vitro neurosphere culture system at 3 and 4 d postinfection. DXM significantly worsened weight loss and survival. Density of BrdU-positive cells, as an index of cells with proliferating activity, was significantly lower in DXM-treated animals compared to vehicle controls (P < 0.0001). In parallel, DXM reduced neurosphere formation as an index for stem/progenitor cell density compared to vehicle treatment (P = 0.01). Our findings provide clear evidence that DXM exerts an antiproliferative effect on the hippocampus in infant rat PM. We conclude that an impairment of regenerative hippocampal capacity should be taken into account when considering adjuvant DXM in the therapeutic regimen for PM in children.
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Chen HL, Lu CH, Chang CD, Chen PC, Chen MH, Hsu NW, Chou KH, Lin WM, Lin CP, Lin WC. Structural deficits and cognitive impairment in tuberculous meningitis. BMC Infect Dis 2015. [PMID: 26198732 PMCID: PMC4510907 DOI: 10.1186/s12879-015-1011-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Background Chronic neuropsychological sequelae may occur in patients with tuberculous meningitis (TBM). The impact of structural abnormalities on the clinical performance of patients with TBM is unknown. This study applied the Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra (DARTEL) voxel-based morphometry (VBM) to determine if gray matter deficits in TBM are associated with acute presentations and chronic cognitive impairment. Methods Seventeen patients with TBM who discontinued their anti-TB therapy for more than six months, and 17 age-, sex-, and education-matched healthy subjects were enrolled. Differences in gray matter volume (GMV) between patients and healthy controls were investigated using DARTEL-VBM to determine structural abnormalities. Disease severity during the acute stage was scored by clinical profiles and conventional imaging findings. Correlations among chronic structural deficits, cognitive impairment, and initial disease severity were assessed. Results The patients with TBM had worse neuropsychological subtest performances than the healthy controls. Compared to the controls, the patients showed smaller GMVs in the right thalamus, right caudate nucleus, right superior and middle temporal gyrus, right precuneus, and left putamen (p < 0.001). The smaller GMVs in the right thalamus, right superior temporal gyrus, right precuneus, left putamen, and right caudate nucleus (p < 0.05) were further associated with worse cognitive function. More severe initial disease also correlated with smaller GMVs in the right caudate nucleus (p < 0.05). Conclusion Multiple domain cognitive impairment may persist in patients with chronic TBM even after appropriate treatment. Worse initial disease severity may contribute to the vulnerability of brain tissue to damage, with subsequent neuropsychological consequences.
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Affiliation(s)
- Hsiu-Ling Chen
- Department of Diagnostic Radiology, Kaohsiung Chang Gung Memorial Hospital, and Chang Gung University College of Medicine, 123 Ta-Pei Road, Niao-Sung, Kaohsiung, 83305, Taiwan. .,Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan.
| | - Cheng-Hsien Lu
- Department of Neurology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
| | - Ching-Di Chang
- Department of Diagnostic Radiology, Kaohsiung Chang Gung Memorial Hospital, and Chang Gung University College of Medicine, 123 Ta-Pei Road, Niao-Sung, Kaohsiung, 83305, Taiwan.
| | - Pei-Chin Chen
- Department of Diagnostic Radiology, Kaohsiung Chang Gung Memorial Hospital, and Chang Gung University College of Medicine, 123 Ta-Pei Road, Niao-Sung, Kaohsiung, 83305, Taiwan.
| | - Meng-Hsiang Chen
- Department of Diagnostic Radiology, Kaohsiung Chang Gung Memorial Hospital, and Chang Gung University College of Medicine, 123 Ta-Pei Road, Niao-Sung, Kaohsiung, 83305, Taiwan.
| | - Nai-Wen Hsu
- Department of Radiology, Yuan's General Hospital, Kaohsiung, Taiwan.
| | - Kun-Hsien Chou
- Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan.
| | - Wei-Ming Lin
- Department of Diagnostic Radiology, Chang Gung Memorial Hospital at Chiayi, Chang Gung University College of Medicine, Chiayi, Taiwan.
| | - Ching-Po Lin
- Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan. .,Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan.
| | - Wei-Che Lin
- Department of Diagnostic Radiology, Kaohsiung Chang Gung Memorial Hospital, and Chang Gung University College of Medicine, 123 Ta-Pei Road, Niao-Sung, Kaohsiung, 83305, Taiwan.
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Holler JG, Brandt CT, Leib SL, Rowland IJ, Østergaard C. Increase in hippocampal water diffusion and volume during experimental pneumococcal meningitis is aggravated by bacteremia. BMC Infect Dis 2014; 14:240. [PMID: 24886045 PMCID: PMC4016615 DOI: 10.1186/1471-2334-14-240] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 04/25/2014] [Indexed: 11/22/2022] Open
Abstract
Background The hippocampus undergoes apoptosis in experimental pneumococcal meningitis leading to neurofunctional deficits in learning and memory function. The aim of the present study was 1) to investigate hippocampal apparent diffusion coefficient (ADC) and volume with MRI during the course of experimental pneumococcal meningitis, 2) to explore the influence of accompanying bacteremia on hippocampal water distribution and volume, 3) and to correlate these findings to the extent of apoptosis in the hippocampus. Methods Experimental meningitis in rats was induced by intracisternal injection of live pneumococci. The study comprised of four experimental groups. I. Uninfected controls (n = 8); II. Meningitis (n = 11); III. Meningitis with early onset bacteremia by additional i.v. injection of live pneumococci (n = 10); IV. Meningitis with attenuated bacteremia by treatment with serotype-specific anti-pneumococcal antibodies (n = 14). T2 and diffusion weighted MR images were used to analyze changes in hippocampus volume and water diffusion (ADC). The results were correlated to ADC of the cortex, to ventricular volume, and to the extent of hippocampal apoptosis. Results Both ADC and the volume of hippocampus were significantly increased in meningitis rats compared to uninfected controls (Kruskal-Wallis test, p = 0.0001, Dunns Post Test, p < 0.05), and were significantly increased in meningitis rats with an early onset bacteremia as compared to meningitis rats with attenuated bacteremia (p < 0.05). Hippocampal ADC and the volume and size of brain ventricles were positively correlated (Spearman Rank, p < 0.05), whereas no association was found between ADC or volume and the extent of apoptosis (p > 0.05). Conclusions In experimental meningitis increase in volume and water diffusion of the hippocampus are significantly associated with accompanying bacteremia.
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Affiliation(s)
- Jon G Holler
- Department of Infectious Diseases, Copenhagen University Hospital Hvidovre, Kettegaard Alle 30, Hvidovre, Copenhagen 2650, Denmark.
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Astrakas LG, Argyropoulou MI. Shifting from region of interest (ROI) to voxel-based analysis in human brain mapping. Pediatr Radiol 2010; 40:1857-67. [PMID: 20464386 DOI: 10.1007/s00247-010-1677-8] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Revised: 03/04/2010] [Accepted: 03/04/2010] [Indexed: 11/27/2022]
Abstract
Current clinical studies involve multidimensional high-resolution images containing an overwhelming amount of structural and functional information. The analysis of such a wealth of information is becoming increasingly difficult yet necessary in order to improve diagnosis, treatment and healthcare. Voxel-wise analysis is a class of modern methods of image processing in the medical field with increased popularity. It has replaced manual region of interest (ROI) analysis and has provided tools to make statistical inferences at voxel level. The introduction of voxel-based analysis software in all modern commercial scanners allows clinical use of these techniques. This review will explain the main principles, advantages and disadvantages behind these methods of image analysis.
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Affiliation(s)
- Loukas G Astrakas
- Medical Physics, Medical School, University of Ioannina, Ioannina, Greece.
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de Jonge RCJ, van Furth AM, Wassenaar M, Gemke RJBJ, Terwee CB. Predicting sequelae and death after bacterial meningitis in childhood: a systematic review of prognostic studies. BMC Infect Dis 2010; 10:232. [PMID: 20684796 PMCID: PMC2921388 DOI: 10.1186/1471-2334-10-232] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2010] [Accepted: 08/05/2010] [Indexed: 11/10/2022] Open
Abstract
Background Bacterial meningitis (BM) is a severe infection responsible for high mortality and disabling sequelae. Early identification of patients at high risk of these outcomes is necessary to prevent their occurrence by adequate treatment as much as possible. For this reason, several prognostic models have been developed. The objective of this study is to summarize the evidence regarding prognostic factors predicting death or sequelae due to BM in children 0-18 years of age. Methods A search in MEDLINE and EMBASE was conducted to identify prognostic studies on risk factors for mortality and sequelae after BM in children. Selection of abstracts, full-text articles and assessment of methodological quality using the QUIPS checklist was performed by two reviewers independently. Data on prognostic factors per outcome were summarized. Results Of the 31 studies identified, 15 were of moderate to high quality. Due to substantial heterogeneity in study characteristics and evaluated prognostic factors, no quantitative analysis was performed. Prognostic factors found to be statistically significant in more than one study of moderate or high quality are: complaints >48 hours before admission, coma/impaired consciousness, (prolonged duration of) seizures, (prolonged) fever, shock, peripheral circulatory failure, respiratory distress, absence of petechiae, causative pathogen Streptococcus pneumoniae, young age, male gender, several cerebrospinal fluid (CSF) parameters and white blood cell (WBC) count. Conclusions Although several important prognostic factors for the prediction of mortality or sequelae after BM were identified, the inability to perform a pooled analysis makes the exact (independent) predictive value of these factors uncertain. This emphasizes the need for additional well-conducted prognostic studies.
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Affiliation(s)
- Rogier C J de Jonge
- VU University Medical Center, Department of Pediatrics and Infectious Diseases, Amsterdam, The Netherlands.
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Østergaard C, Leib SL, Rowland I, Brandt CT. Bacteremia causes hippocampal apoptosis in experimental pneumococcal meningitis. BMC Infect Dis 2010; 10:1. [PMID: 20044936 PMCID: PMC2824701 DOI: 10.1186/1471-2334-10-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2009] [Accepted: 01/03/2010] [Indexed: 11/26/2022] Open
Abstract
Background Bacteremia and systemic complications both play important roles in brain pathophysiological alterations and the outcome of pneumococcal meningitis. Their individual contributions to the development of brain damage, however, still remain to be defined. Methods Using an adult rat pneumococcal meningitis model, the impact of bacteremia accompanying meningitis on the development of hippocampal injury was studied. The study comprised of the three groups: I. Meningitis (n = 11), II. meningitis with attenuated bacteremia resulting from iv injection of serotype-specific pneumococcal antibodies (n = 14), and III. uninfected controls (n = 6). Results Pneumococcal meningitis resulted in a significantly higher apoptosis score 0.22 (0.18-0.35) compared to uninfected controls (0.02 (0.00-0.02), Mann Whitney test, P = 0.0003). Also, meningitis with an attenuation of bacteremia by antibody treatment resulted in significantly reduced apoptosis (0.08 (0.02-0.20), P = 0.01) as compared to meningitis. Conclusions Our results demonstrate that bacteremia accompanying meningitis plays an important role in the development of hippocampal injury in pneumococcal meningitis.
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Affiliation(s)
- Christian Østergaard
- Department of Clinical Microbiology, Copenhagen University Hospital Herlev, Herlev, Denmark.
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