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Cope C, Davis AG, Baum RA, Haskal ZJ, Soulen MC, Shlansky-Goldberg RD. Direct percutaneous jejunostomy: techniques and applications--ten years experience. Radiology 1998; 209:747-54. [PMID: 9844669 DOI: 10.1148/radiology.209.3.9844669] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To present 10 years experience with direct fluoroscopically guided percutaneous jejunostomy. MATERIALS AND METHODS Percutaneous jejunostomy was performed in 62 patients, most of whom had undergone major abdominal surgery. A new or replacement jejunostomy was created for alimentation in 20 and 21 patients, respectively. Jejunostomy was performed for interventional procedures of the bile ducts or intestine in 13 patients and for retrograde gastroesophageal drainage in eight. The distended jejunum was accessed with a 21-gauge needle, immobilized with a gastric anchor, and catheterized with a 10-14-F locking loop drain. RESULTS The technical success rate was 19 of 20 (95%) for new feeding jejunostomy and 17 of 21 (81%) for replacement feeding jejunostomy. Jejunostomy facilitated drainage, dilation, stone extraction, and recanalization in the bile ducts or intestine in all 13 patients. Retrograde jejunoesophagogastrostomy suction effectively replaced painful nasogastric suction in all eight patients. Two patients who underwent replacement jejunostomy required laparotomy for possible leakage; there was no important procedure-related morbidity and no procedure-related mortality. CONCLUSION The technical success and complication rates of feeding percutaneous jejunostomy compare favorably with those of surgery or endoscopy. Percutaneous jejunostomy is a useful and underused approach to managing bowel and biliary obstruction.
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Siegfried JM, DeMichele MA, Hunt JD, Davis AG, Vohra KP, Pilewski JM. Expression of mRNA for gastrin-releasing peptide receptor by human bronchial epithelial cells. Association with prolonged tobacco exposure and responsiveness to bombesin-like peptides. Am J Respir Crit Care Med 1997; 156:358-66. [PMID: 9279210 DOI: 10.1164/ajrccm.156.2.9608047] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Bombesin-like peptides (BLPs) are important regulators of lung development and may also act as autocrine growth factors in lung tumors. We have previously demonstrated expression of mRNA for the three BLP receptor subtypes (neuromedin B [NMB]) receptor, gastrin-releasing peptide [GRP] receptor, and bombesin receptor subtype 3 [BRS-3]) in human non-small cell lung carcinoma (NSCLC) cell lines and bronchial biopsies using the reverse transcription-polymerase chain reaction (RT-PCR; DeMichele, et al. Am. J. Respir. Cell Mol. Biol. 1994; 11:66-74). We have also previously found that growth responses to BLPs could be elicited in some, but not all, cultures of human bronchial epithelial (HBE) cells (Siegfried, et al. Anat. Rec. 1993; 236:241-247). In this report, we utilized RT-PCR to demonstrate mRNA expression of BLP receptor subtypes in cultured HBE cells and also assessed the response of these cultures to BLPs in proliferation assays. The pattern of mRNA expression was correlated with proliferative response, and the results were also analyzed in relation to smoking history and pulmonary function of the subjects studied. Our results suggest that expression of mRNA for the GRP receptor is associated with a long smoking history (> 25 pack-years [PY], p = 0.02). This association was related to past tobacco exposure, regardless of whether the subjects were still active smokers at the time of tissue procurement. Responsiveness to GRP and NMB in proliferation assays was also found only in those HBE cultures with expression of mRNA for at least one of the known receptors for BLPs, and there was a significant association between expression of mRNA for the GRP receptor and proliferative response to both GRP and NMB (p = 0.048). HBE cultures from subjects with a greater than 25 PY smoking history were also more likely to respond to BLPs in the proliferation assays than cells from subjects with less than a 25 PY history (10 of 16 versus 1 of 7, p = 0.06). Cultures of HBE cells from four of the five subjects with severe obstructive lung disease gave a positive response to GRP and NMB in proliferation assays, compared to five of fifteen without severe obstructive lung disease, but this difference was not significant (p = 0.13). These results suggest there is an increased likelihood of expression of the GRP receptor mRNA in the respiratory epithelium of some individuals with a history of prolonged tobacco exposure, and that expression of the GRP receptor mRNA is accompanied by responsiveness to the mitogenic effects of BLPs. These effects appear to persist after smoking cessation.
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Schutz C, Davis AG, Sossen B, Lai RPJ, Ntsekhe M, Harley YXR, Wilkinson RJ. Corticosteroids as an adjunct to tuberculosis therapy. Expert Rev Respir Med 2018; 12:881-891. [PMID: 30138039 PMCID: PMC6293474 DOI: 10.1080/17476348.2018.1515628] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
INTRODUCTION Inflammation, or the prolonged resolution of inflammation, contributes to death from tuberculosis. Interest in inflammatory mechanisms and the prospect of beneficial immune modulation as an adjunct to antibacterial therapy has revived and the concept of host directed therapies has been advanced. Such renewed attention has however, overlooked the experience of such therapy with corticosteroids. Areas covered: The authors conducted literature searches and evaluated randomized clinical trials, systematic reviews and current guidelines and summarize these findings. They found evidence of benefit in meningeal and pericardial tuberculosis in HIV-1 uninfected persons, but less so in those HIV-1 coinfected and evidence of harm in the form of opportunist malignancy in those not prescribed antiretroviral therapy. Adjunctive corticosteroids are however of benefit in the treatment and prevention of paradoxical HIV-tuberculosis immune reconstitution inflammatory syndrome. Expert commentary: Further high-quality clinical trials and experimental medicine studies are warranted and analysis of materials arising from such studies could illuminate ways to improve corticosteroid efficacy or identify novel pathways for more specific intervention.
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Research Support, N.I.H., Extramural |
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30 |
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Davis AG, Huff CG, Palmer TT. Procedures for maximum production of exoerythrocytic stages of Plasmodium fallax in tissue culture. Exp Parasitol 1966; 19:1-8. [PMID: 5951204 DOI: 10.1016/0014-4894(66)90045-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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29 |
5
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Davis AG, Haskal ZJ. Extrahepatic portal vein puncture and intra-abdominal hemorrhage during transjugular intrahepatic portosystemic shunt creation. J Vasc Interv Radiol 1996; 7:863-6. [PMID: 8951754 DOI: 10.1016/s1051-0443(96)70863-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
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Case Reports |
29 |
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6
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Abstract
Spina bifida occulta occurs in 5-10% of the population, not all of whom display superficial signs. Attempted epidural puncture at the level of the lesion will almost certainly result in a dural tap. We report a patient who developed a postural headache after Caesarean section under epidural anaesthesia, in whom radiography of the spine later demonstrated spina bifida occulta. This problem has not been described previously, although it is unlikely to be an isolated case.
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Case Reports |
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du Bruyn E, Stek C, Daroowala R, Said-Hartley Q, Hsiao M, Schafer G, Goliath RT, Abrahams F, Jackson A, Wasserman S, Allwood BW, Davis AG, Lai RPJ, Coussens AK, Wilkinson KA, de Vries J, Tiffin N, Cerrone M, Ntusi NAB, Riou C, Wilkinson RJ. Effects of tuberculosis and/or HIV-1 infection on COVID-19 presentation and immune response in Africa. Nat Commun 2023; 14:188. [PMID: 36635274 PMCID: PMC9836341 DOI: 10.1038/s41467-022-35689-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 12/19/2022] [Indexed: 01/14/2023] Open
Abstract
Few studies from Africa have described the clinical impact of co-infections on SARS-CoV-2 infection. Here, we investigate the presentation and outcome of SARS-CoV-2 infection in an African setting of high HIV-1 and tuberculosis prevalence by an observational case cohort of SARS-CoV-2 patients. A comparator group of non SARS-CoV-2 participants is included. The study includes 104 adults with SARS-CoV-2 infection of whom 29.8% are HIV-1 co-infected. Two or more co-morbidities are present in 57.7% of participants, including HIV-1 (30%) and active tuberculosis (14%). Amongst patients dually infected by tuberculosis and SARS-CoV-2, clinical features can be typical of either SARS-CoV-2 or tuberculosis: lymphopenia is exacerbated, and some markers of inflammation (D-dimer and ferritin) are further elevated (p < 0.05). Amongst HIV-1 co-infected participants those with low CD4 percentage strata exhibit reduced total, but not neutralising, anti-SARS-CoV-2 antibodies. SARS-CoV-2 specific CD8 T cell responses are present in 35.8% participants overall but undetectable in combined HIV-1 and tuberculosis. Death occurred in 30/104 (29%) of all COVID-19 patients and in 6/15 (40%) of patients with coincident SARS-CoV-2 and tuberculosis. This shows that in a high incidence setting, tuberculosis is a common co-morbidity in patients admitted to hospital with COVID-19. The immune response to SARS-CoV-2 is adversely affected by co-existent HIV-1 and tuberculosis.
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Davis AG, Nightingale S, Springer PE, Solomons R, Arenivas A, Wilkinson RJ, Anderson ST, Chow FC. Neurocognitive and functional impairment in adult and paediatric tuberculous meningitis. Wellcome Open Res 2019; 4:178. [PMID: 31984243 PMCID: PMC6971841 DOI: 10.12688/wellcomeopenres.15516.1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/01/2019] [Indexed: 12/20/2022] Open
Abstract
In those who survive tuberculous meningitis (TBM), the long-term outcome is uncertain; individuals may suffer neurocognitive, functional and psychiatric impairment, which may significantly affect their ability to lead their lives as they did prior to their diagnosis of TBM. In children who survive, severe illness has occurred at a crucial timepoint in their development, which can lead to behavioural and cognitive delay. The extent and nature of this impairment is poorly understood, particularly in adults. This is in part due to a lack of observational studies in this area but also inconsistent inclusion of outcome measures which can quantify these deficits in clinical studies. This leads to a paucity of appropriate rehabilitative therapies available for these individuals and their caregivers, as well as burden at a socioeconomic level. In this review, we discuss what is known about neurocognitive impairment in TBM, draw on lessons learnt from other neurological infections and discuss currently available and emerging tools to evaluate function and cognition and their value in TBM. We make recommendations on which measures should be used at what timepoints to assess for impairment, with a view to optimising and standardising assessment of neurocognitive and functional impairment in TBM research.
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Review |
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Norton AC, Davis AG, Spicer RJ. Lignocaine 2% with adrenaline for epidural caesarean section. A comparison with 0.5% bupivacaine. Anaesthesia 1988; 43:844-9. [PMID: 3059842 DOI: 10.1111/j.1365-2044.1988.tb05597.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A randomised double blind controlled trial of freshly prepared 2% lignocaine with 1/200,000 adrenaline and 0.5% plain bupivacaine was conducted on 60 women undergoing elective Caesarean section. The use of the former enabled epidural blockade to above the T6 dermatome to be established in a significantly shorter time than with bupivacaine (p less than 0.005). The quality of sensory blockade and incidence of complications was similar in the two groups. The solutions were of similar potency as measured by the volume required per segment blocked. Motor blockade was more intense with 2% lignocaine with adrenaline (p less than 0.03). More neonates had moderately depressed Apgar scores (5-7) at one minute in the lignocaine group but this difference was not statistically significant, and there was no difference in the distribution of Apgar scores at 3 minutes. Lignocaine with 1/200,000 adrenaline is a useful alternative to 0.5% plain bupivacaine when it is desired to establish rapidly epidural blockade for Caesarean section.
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Clinical Trial |
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10
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Abstract
A double-blind randomised study was performed to assess the analgesic effect of epidural diamorphine, administered with bupivacaine, on primigravid women in labour. Fifty patients received 0.25% bupivacaine 10 ml via the epidural catheter as their initial dose; patients in Group 1 received diamorphine 5 mg with the bupivacaine. A 0.1% bupivacaine infusion was started at 10 minutes and bolus doses of bupivacaine were given if required. There was a significant reduction in rate of bupivacaine administration, pain scores at 20 and 30 minutes, number of supplements required, and degree of motor blockade in the diamorphine group.
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Clinical Trial |
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11
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Abstract
This study of the obstetric and anaesthetic circumstances relating to 100 consecutive Caesarean sections under general anaesthesia suggests that the general anaesthesia rate for Caesarean section could be reduced from the present 37 to 27% by making maximum use of epidural block and to 16% by using subarachnoid block in addition. The need for general anaesthesia on account of urgency to deliver can be greatly reduced by the administration of epidural analgesia during labour in patients identified as being more likely than average to require Caesarean section, and by the use of subarachnoid block when the need for section arises unexpectantly. Patients' objections to undergoing Caesarean section while conscious were analysed, and suggestions are made for minimising the number of patients who decline. Technical problems with blocks may sometimes be overcome without resort to general anaesthesia, while patients at risk from haemorrhage or coagulopathy will continue to require general anaesthesia.
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Davis AG, Wasserman S, Stek C, Maxebengula M, Liang CJ, Stegmann S, Koekemoer S, Jackson A, Kadernani Y, Bremer M, Daroowala R, Aziz S, Goliath R, Sai LL, Sihoyiya T, Denti P, Lai RP, Crede T, Naude J, Szymanski P, Vallie Y, Banderker IA, Moosa MS, Raubenheimer P, Candy S, Offiah C, Wahl G, Vorster I, Maartens G, Black J, Meintjes G, Wilkinson RJ. A phase 2A trial of the safety and tolerability of increased dose rifampicin and adjunctive linezolid, with or without aspirin, for HIV-associated tuberculous meningitis (The LASER-TBM Trial). Clin Infect Dis 2022; 76:1412-1422. [PMID: 36482216 PMCID: PMC10110270 DOI: 10.1093/cid/ciac932] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 11/12/2022] [Accepted: 12/06/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Drug regimens which include intensified antibiotics alongside effective anti-inflammatory therapies may improve outcomes in Tuberculous Meningitis (TBM). Safety data on their use in combination and in the context of HIV is needed to inform clinical trial design. METHODS We conducted a phase 2 open-label parallel-design RCT to assess safety of high-dose rifampicin, linezolid and high-dose aspirin in HIV-associated TBM. Participants were randomised (1.4:1:1) to three treatment arms (arm 1, standard of care (SOC); arm 2 SOC + additional rifampicin (up to 35mg/kg/day)) + linezolid 1200mg/day reducing after 28/7 to 600mg/day; arm 3, as per arm 2 + aspirin 1000mg/day) for 56 days, when the primary outcome of adverse events of special interest (AESI) or death was assessed. RESULTS 52 participants with HIV-associated TBM were randomised. 59% had mild disease (MRC Grade 1) vs 39% (Grade 2) vs 2% (Grade 3). 33% had microbiologically-confirmed TBM; 41% 'possible', 25% 'probable'. AESI or death occurred in 10/16 (63%) (arm 3) vs 4/14 (29%) (arm 2) vs 6/20 (30%) (arm 1) (p = 0.083). The cumulative proportion of AESI or death (Kaplan-Meier) demonstrated worse outcomes in arm 3 vs arm 1 (p = 0.04), however only one event in arm 3 was attributable to aspirin and was mild. There was no difference in efficacy (modified Rankin scale) at day 56 between arms. CONCLUSIONS High-dose rifampicin and adjunctive linezolid can safely be added to SOC in HIV-associated TBM. Larger studies are required to evaluate whether potential toxicity associated with these interventions, particularly high-dose aspirin, is outweighed by mortality or morbidity benefit.
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Weng S, Matsuura S, Mowery CT, Stoner SA, Lam K, Ran D, Davis AG, Lo MC, Zhang DE. Restoration of MYC-repressed targets mediates the negative effects of GM-CSF on RUNX1-ETO leukemogenicity. Leukemia 2016; 31:159-169. [PMID: 27389055 PMCID: PMC5214981 DOI: 10.1038/leu.2016.167] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 05/19/2016] [Accepted: 05/23/2016] [Indexed: 02/06/2023]
Abstract
GM-CSF signaling regulates hematopoiesis and immune responses. CSF2RA, the gene encoding the α subunit for GM-CSF, is significantly downregulated in t(8;21) (RUNX1-ETO or RE) leukemia patients, suggesting that it may serve as a tumor suppressor. We previously reported that GM-CSF signaling is inhibitory to RE leukemogenesis. Here we conducted gene expression profiling of primary RE hematopoietic stem/progenitor cells (HSPCs) treated with GM-CSF to elucidate the mechanisms mediating the negative effects of GM on RE leukemogenicity. We observed that GM treatment of RE HSPCs resulted in a unique gene expression profile that resembles primary human cells undergoing myelopoiesis, which was not observed in control HSPCs. Additionally we discovered that GM-CSF signaling attenuates MYC-associated gene signatures in RE HSPCs. In agreement with this, a functional screen of a subset of GM-CSF-responsive genes demonstrated that a MYC inhibitor, MXI1, reduced the leukemic potential of RE HSPCs and t(8;21) AML cells. Furthermore, MYC knockdown and treatment with the BET inhibitor JQ1 reduced the leukemic potential of t(8;21) cell lines. Altogether, we discovered a novel molecular mechanism mediating the GM-CSF-induced reduction in leukemic potential of RE cells, and our findings support MYC inhibition as an effective strategy for reducing the leukemogenicity of t(8;21) AML.
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Research Support, N.I.H., Extramural |
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Cresswell FV, Davis AG, Sharma K, Basu Roy R, Ganiem AR, Kagimu E, Solomons R, Wilkinson RJ, Bahr NC, Thuong NTT. Recent Developments in Tuberculous Meningitis Pathogenesis and Diagnostics. Wellcome Open Res 2021; 4:164. [PMID: 33364436 PMCID: PMC7739117 DOI: 10.12688/wellcomeopenres.15506.3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/15/2021] [Indexed: 12/13/2022] Open
Abstract
The pathogenesis of Tuberculous meningitis (TBM) is poorly understood, but contemporary molecular biology technologies have allowed for recent improvements in our understanding of TBM. For instance, neutrophils appear to play a significant role in the immunopathogenesis of TBM, and either a paucity or an excess of inflammation can be detrimental in TBM. Further, severity of HIV-associated immunosuppression is an important determinant of inflammatory response; patients with the advanced immunosuppression (CD4+ T-cell count of <150 cells/μL) having higher CSF neutrophils, greater CSF cytokine concentrations and higher mortality than those with CD4+ T-cell counts > 150 cells/μL. Host genetics may also influence outcomes with LT4AH genotype predicting inflammatory phenotype, steroid responsiveness and survival in Vietnamese adults with TBM. Whist in Indonesia, CSF tryptophan level was a predictor of survival, suggesting tryptophan metabolism may be important in TBM pathogenesis. These varying responses mean that we must consider whether a "one-size-fits-all" approach to anti-bacillary or immunomodulatory treatment in TBM is truly the best way forward. Of course, to allow for proper treatment, early and rapid diagnosis of TBM must occur. Diagnosis has always been a challenge but the field of TB diagnosis is evolving, with sensitivities of at least 70% now possible in less than two hours with GeneXpert MTB/Rif Ultra. In addition, advanced molecular techniques such as CRISPR-MTB and metagenomic next generation sequencing may hold promise for TBM diagnosis. Host-based biomarkers and signatures are being further evaluated in childhood and adult TBM as adjunctive biomarkers as even with improved molecular assays, cases are still missed. A better grasp of host and pathogen behaviour may lead to improved diagnostics, targeted immunotherapy, and possibly biomarker-based, patient-specific treatment regimens.
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Review |
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Davis AG, Dreyer AJ, Albertyn C, Maxebengula M, Stek C, Wasserman S, Marais S, Bateman K, Solms M, Joska J, Wilkinson RJ, Nightingale S. Cognitive Impairment in Tuberculous Meningitis. Clin Infect Dis 2023; 76:842-849. [PMID: 36262054 PMCID: PMC9989126 DOI: 10.1093/cid/ciac831] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 10/03/2022] [Accepted: 10/17/2022] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Cognitive impairment is reported as a common complication in adult tuberculous meningitis (TBM), yet few studies have systematically assessed the frequency and nature of impairment. Moreover, the impact of impairment on functioning and medication adherence has not been described. METHODS A cognitive test battery (10 measures assessing 7 cognitive domains) was administered to 34 participants with human immunodeficiency virus (HIV)-associated TBM 6 months after diagnosis. Cognitive performance was compared with that a comparator group of 66 people with HIV without a history of tuberculosis. A secondary comparison was made between participants with TBM and 26 participants with HIV 6 months after diagnosis of tuberculosis outside the central nervous system (CNS). Impact on functioning was evaluated, including through assessment of medication adherence. RESULTS Of 34 participants with TBM, 16 (47%) had low performance on cognitive testing. Cognition was impaired across all domains. Global cognitive performance was significantly lower in participants with TBM than in people with HIV (mean T score, 41 vs 48, respectively; P < .001). These participants also had lower global cognition scores than those with non-CNS tuberculosis (mean global T score, 41 vs 46; P = .02). Functional outcomes were not significantly correlated with cognitive performance in the subgroup of participants in whom this was assessed (n = 19). CONCLUSIONS Low cognitive performance following HIV-associated TBM is common. This effect is independent of, and additional to, effects of HIV and non-CNS tuberculosis disease. Further studies are needed to understand longer-term outcomes, clarify the association with treatment adherence, a key predictor of outcome in TBM, and develop context-specific tools to identify individuals with cognitive difficulties in order to improve outcomes in TBM.
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Research Support, N.I.H., Extramural |
2 |
10 |
16
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Cresswell FV, Davis AG, Sharma K, Basu Roy R, Ganiem AR, Kagimu E, Solomons R, Wilkinson RJ, Bahr NC, Thuong NTT. Recent Developments in Tuberculous Meningitis Pathogenesis and Diagnostics. Wellcome Open Res 2019; 4:164. [PMID: 33364436 PMCID: PMC7739117 DOI: 10.12688/wellcomeopenres.15506.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/16/2019] [Indexed: 12/15/2022] Open
Abstract
The pathogenesis of Tuberculous meningitis (TBM) is poorly understood, but contemporary molecular biology technologies have allowed for recent improvements in our understanding of TBM. For instance, neutrophils appear to play a significant role in the immunopathogenesis of TBM, and either a paucity or an excess of inflammation can be detrimental in TBM. Further, severity of HIV-associated immunosuppression is an important determinant of inflammatory response; patients with the advanced immunosuppression (CD4+ T-cell count of <150 cells/μL) having higher CSF neutrophils, greater CSF cytokine concentrations and higher mortality than those with CD4+ T-cell counts > 150 cells/μL. Host genetics may also influence outcomes with LT4AH genotype predicting inflammatory phenotype, steroid responsiveness and survival in Vietnamese adults with TBM. Whist in Indonesia, CSF tryptophan level was a predictor of survival, suggesting tryptophan metabolism may be important in TBM pathogenesis. These varying responses mean that we must consider whether a "one-size-fits-all" approach to anti-bacillary or immunomodulatory treatment in TBM is truly the best way forward. Of course, to allow for proper treatment, early and rapid diagnosis of TBM must occur. Diagnosis has always been a challenge but the field of TB diagnosis is evolving, with sensitivities of at least 70% now possible in less than two hours with GeneXpert MTB/Rif Ultra. In addition, advanced molecular techniques such as CRISPR-MTB and metagenomic next generation sequencing may hold promise for TBM diagnosis. Host-based biomarkers and signatures are being further evaluated in childhood and adult TBM as adjunctive biomarkers as even with improved molecular assays, cases are still missed. A better grasp of host and pathogen behaviour may lead to improved diagnostics, targeted immunotherapy, and possibly biomarker-based, patient-specific treatment regimens.
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Review |
6 |
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Pilewski JM, Bumbalo TS, Davis AG, Siegfried JM. Hepatocyte growth factor promotes tumor growth in a novel in vivo model of human lung cancer. Am J Respir Cell Mol Biol 2001; 24:556-62. [PMID: 11350824 DOI: 10.1165/ajrcmb.24.5.4074] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Significant progress has been made toward identifying growth factors that display autocrine or paracrine effects on the growth of lung cancer cells. Determining the in vivo relevance of specific growth factors on lung tumor formation, however, has not often been demonstrated in laboratory models. Although hepatocyte growth factor (HGF) has been shown to have mitogenic and motogenic effects on human lung cancer cells in vitro, and to have prognostic importance in patients with lung cancer, the effects of HGF on tumor behavior in vivo remain unknown. We therefore developed an airway tumor xenograft model that allowed us to test the hypothesis that HGF promotes human non-small cell lung cancer (NSCLC) growth in vivo. Human airway tumor xenografts were created in Severe Combined Immunodeficient mice by injecting human lung adenocarcinoma cells into human bronchial segments. After determining the optimal times for tumor-cell injection and the time course of tumor growth, we evaluated the effects of HGF on tumor growth by injecting recombinant HGF, or saline as a control, into the lumen of tumor xenografts for 10 consecutive days. Histologic evaluation 2 to 3 wk later revealed that the HGF-injected xenografts had a significantly greater tumor volume and more tumor cells were located in the submucosal space than were found in the saline-injected xenografts. These data demonstrate the usefulness of this novel in vivo model to study NSCLC, and show that HGF promotes both the growth and invasion of human lung cancer in vivo.
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Research Support, U.S. Gov't, P.H.S. |
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Davis AG, Wasserman S, Maxebengula M, Stek C, Bremer M, Daroowala R, Aziz S, Goliath R, Stegmann S, Koekemoer S, Jackson A, Lai Sai L, Kadernani Y, Sihoyiya T, Liang CJ, Dodd L, Denti P, Crede T, Naude J, Szymanski P, Vallie Y, Banderker I, Moosa S, Raubenheimer P, Lai RPJ, Joska J, Nightingale S, Dreyer A, Wahl G, Offiah C, Vorster I, Candy S, Robertson F, Meintjes E, Maartens G, Black J, Meintjes G, Wilkinson RJ. Study protocol for a phase 2A trial of the safety and tolerability of increased dose rifampicin and adjunctive linezolid, with or without aspirin, for HIV-associated tuberculous meningitis [LASER-TBM]. Wellcome Open Res 2021; 6:136. [PMID: 34286103 PMCID: PMC8283551 DOI: 10.12688/wellcomeopenres.16783.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/21/2021] [Indexed: 11/20/2022] Open
Abstract
Background: Tuberculous meningitis (TBM) is the most lethal form of tuberculosis with a mortality of ~50% in those co-infected with HIV-1. Current antibiotic regimens are based on those known to be effective in pulmonary TB and do not account for the differing ability of the drugs to penetrate the central nervous system (CNS). The host immune response drives pathology in TBM, yet effective host-directed therapies are scarce. There is sufficient data to suggest that higher doses of rifampicin (RIF), additional linezolid (LZD) and adjunctive aspirin (ASA) will be beneficial in TBM yet rigorous investigation of the safety of these interventions in the context of HIV associated TBM is required. We hypothesise that increased dose RIF, LZD and ASA used in combination and in addition to standard of care for the first 56 days of treatment with be safe and tolerated in HIV-1 infected people with TBM. Methods: In an open-label randomised parallel study, up to 100 participants will receive either; i) standard of care (n=40, control arm), ii) standard of care plus increased dose RIF (35mg/kg) and LZD (1200mg OD for 28 days, 600mg OD for 28 days) (n=30, experimental arm 1), or iii) as per experimental arm 1 plus additional ASA 1000mg OD (n=30, experimental arm 2). After 56 days participants will continue standard treatment as per national guidelines. The primary endpoint is death and the occurrence of solicited treatment-related adverse events at 56 days. In a planned pharmacokinetic (PK) sub-study we aim to assess PK/pharmacodynamic (PD) of oral vs IV rifampicin, describe LZD and RIF PK and cerebrospinal fluid concentrations, explore PK/PD relationships, and investigate drug-drug interactions between LZD and RIF. Safety and pharmacokinetic data from this study will inform a planned phase III study of intensified therapy in TBM. Clinicaltrials.gov registration: NCT03927313 (25/04/2019)
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Davis AG, Donovan J, Bremer M, Van Toorn R, Schoeman J, Dadabhoy A, Lai RP, Cresswell FV, Boulware DR, Wilkinson RJ, Thuong NTT, Thwaites GE, Bahr NC. Host Directed Therapies for Tuberculous Meningitis. Wellcome Open Res 2020; 5:292. [PMID: 35118196 PMCID: PMC8792876 DOI: 10.12688/wellcomeopenres.16474.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/08/2020] [Indexed: 12/15/2022] Open
Abstract
A dysregulated host immune response significantly contributes to morbidity and mortality in tuberculous meningitis (TBM). Effective host directed therapies (HDTs) are critical to improve survival and clinical outcomes. Currently only one HDT, dexamethasone, is proven to improve mortality. However, there is no evidence dexamethasone reduces morbidity, how it reduces mortality is uncertain, and it has no proven benefit in HIV co-infected individuals. Further research on these aspects of its use, as well as alternative HDTs such as aspirin, thalidomide and other immunomodulatory drugs is needed. Based on new knowledge from pathogenesis studies, repurposed therapeutics which act upon small molecule drug targets may also have a role in TBM. Here we review existing literature investigating HDTs in TBM, and propose new rationale for the use of novel and repurposed drugs. We also discuss host variable responses and evidence to support a personalised approach to HDTs in TBM.
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Davis AG, Donovan J, Bremer M, Van Toorn R, Schoeman J, Dadabhoy A, Lai RP, Cresswell FV, Boulware DR, Wilkinson RJ, Thuong NTT, Thwaites GE, Bahr NC. Host Directed Therapies for Tuberculous Meningitis. Wellcome Open Res 2021; 5:292. [PMID: 35118196 PMCID: PMC8792876 DOI: 10.12688/wellcomeopenres.16474.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/2021] [Indexed: 12/12/2022] Open
Abstract
A dysregulated host immune response significantly contributes to morbidity and mortality in tuberculous meningitis (TBM). Effective host directed therapies (HDTs) are critical to improve survival and clinical outcomes. Currently only one HDT, dexamethasone, is proven to improve mortality. However, there is no evidence dexamethasone reduces morbidity, how it reduces mortality is uncertain, and it has no proven benefit in HIV co-infected individuals. Further research on these aspects of its use, as well as alternative HDTs such as aspirin, thalidomide and other immunomodulatory drugs is needed. Based on new knowledge from pathogenesis studies, repurposed therapeutics which act upon small molecule drug targets may also have a role in TBM. Here we review existing literature investigating HDTs in TBM, and propose new rationale for the use of novel and repurposed drugs. We also discuss host variable responses and evidence to support a personalised approach to HDTs in TBM.
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Cresswell FV, Davis AG, Sharma K, Basu Roy R, Ganiem AR, Kagimu E, Solomons R, Wilkinson RJ, Bahr NC, Thuong NTT. Recent Developments in Tuberculous Meningitis Pathogenesis and Diagnostics. Wellcome Open Res 2020; 4:164. [PMID: 33364436 PMCID: PMC7739117 DOI: 10.12688/wellcomeopenres.15506.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/24/2020] [Indexed: 12/15/2022] Open
Abstract
The pathogenesis of Tuberculous meningitis (TBM) is poorly understood, but contemporary molecular biology technologies have allowed for recent improvements in our understanding of TBM. For instance, neutrophils appear to play a significant role in the immunopathogenesis of TBM, and either a paucity or an excess of inflammation can be detrimental in TBM. Further, severity of HIV-associated immunosuppression is an important determinant of inflammatory response; patients with the advanced immunosuppression (CD4+ T-cell count of <150 cells/μL) having higher CSF neutrophils, greater CSF cytokine concentrations and higher mortality than those with CD4+ T-cell counts > 150 cells/μL. Host genetics may also influence outcomes with LT4AH genotype predicting inflammatory phenotype, steroid responsiveness and survival in Vietnamese adults with TBM. Whist in Indonesia, CSF tryptophan level was a predictor of survival, suggesting tryptophan metabolism may be important in TBM pathogenesis. These varying responses mean that we must consider whether a "one-size-fits-all" approach to anti-bacillary or immunomodulatory treatment in TBM is truly the best way forward. Of course, to allow for proper treatment, early and rapid diagnosis of TBM must occur. Diagnosis has always been a challenge but the field of TB diagnosis is evolving, with sensitivities of at least 70% now possible in less than two hours with GeneXpert MTB/Rif Ultra. In addition, advanced molecular techniques such as CRISPR-MTB and metagenomic next generation sequencing may hold promise for TBM diagnosis. Host-based biomarkers and signatures are being further evaluated in childhood and adult TBM as adjunctive biomarkers as even with improved molecular assays, cases are still missed. A better grasp of host and pathogen behaviour may lead to improved diagnostics, targeted immunotherapy, and possibly biomarker-based, patient-specific treatment regimens.
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Davis AG. Goal attainment of psychiatric clients after group experience to learn social independence skills. Issues Ment Health Nurs 1981; 3:159-83. [PMID: 6909152 DOI: 10.3109/01612848109140867] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Bremer M, Kadernani YE, Wasserman S, Wilkinson RJ, Davis AG. Strategies for the diagnosis and management of meningitis in HIV-infected adults in resource limited settings. Expert Opin Pharmacother 2021; 22:2053-2070. [PMID: 34154509 DOI: 10.1080/14656566.2021.1940954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
INTRODUCTION The incidence of human immunodeficiency virus-1 (HIV-1) associated meningitis has been declining in the post-combination antiretroviral treatment (ART) era, although survival rates remain low for the common causes like tuberculosis and cryptococcal disease. Diagnosis and treatment of meningitis in HIV-1 is complicated by atypical clinical presentations, limited accuracy of diagnostic tests, access to diagnostic tests, and therapeutic agents in low- and middle-income countries (LMIC) and immune reconstitution inflammatory syndrome (IRIS). AREAS COVERED We provide an overview of the common etiologies of meningitis in HIV-1-infected adults, suggest a diagnostic approach based on readily available tests, and review specific chemotherapeutic agents, host-directed therapies, supportive care, timing of ART initiation, and considerations in the management of IRIS with a focus on resource-limited settings. They identify key knowledge gaps and suggest areas for future research. EXPERT OPINION Evidence-based management of HIV-1-associated meningitis is sparse for common etiologies. More readily available and sensitive diagnostic tests as well as standardized investigation strategies are required in LMIC. There is a lack of availability of recommended drugs in areas of high HIV-1 prevalence and a limited pipeline of novel chemotherapeutic agents. Host-directed therapies have been inadequately studied.
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Wasserman S, Donovan J, Kestelyn E, Watson JA, Aarnoutse RE, Barnacle JR, Boulware DR, Chow FC, Cresswell FV, Davis AG, Dooley KE, Figaji AA, Gibb DM, Huynh J, Imran D, Marais S, Meya DB, Misra UK, Modi M, Raberahona M, Ganiem AR, Rohlwink UK, Ruslami R, Seddon JA, Skolimowska KH, Solomons RS, Stek CJ, Thuong NTT, van Crevel R, Whitaker C, Thwaites GE, Wilkinson RJ. Advancing the chemotherapy of tuberculous meningitis: a consensus view. THE LANCET. INFECTIOUS DISEASES 2025; 25:e47-e58. [PMID: 39342951 PMCID: PMC7616680 DOI: 10.1016/s1473-3099(24)00512-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2024] [Revised: 08/02/2024] [Accepted: 08/05/2024] [Indexed: 10/01/2024]
Abstract
Tuberculous meningitis causes death or disability in approximately 50% of affected individuals and kills approximately 78 200 adults every year. Antimicrobial treatment is based on regimens used for pulmonary tuberculosis, which overlooks important differences between lung and brain drug distributions. Tuberculous meningitis has a profound inflammatory component, yet only adjunctive corticosteroids have shown clear benefit. There is an active pipeline of new antitubercular drugs, and the advent of biological agents targeted at specific inflammatory pathways promises a new era of improved tuberculous meningitis treatment and outcomes. Yet, to date, tuberculous meningitis trials have been small, underpowered, heterogeneous, poorly generalisable, and have had little effect on policy and practice. Progress is slow, and a new approach is required. In this Personal View, a global consortium of tuberculous meningitis researchers articulate a coordinated, definitive way ahead via globally conducted clinical trials of novel drugs and regimens to advance treatment and improve outcomes for this life-threatening infection.
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