Injectable Antioxidant and Oxygen-Releasing Lignin Composites to Promote Wound Healing.

The application of engineered biomaterials for wound healing has been pursued since the beginning of tissue engineering. Here, we attempt to apply functionalized lignin to confer antioxidation to the extracellular microenvironments of wounds and to deliver oxygen from the dissociation of calcium peroxide for enhanced vascularization and healing responses without eliciting inflammatory responses. Elemental analysis showed 17 times higher quantity of calcium in the oxygen-releasing nanoparticles. Lignin composites including the oxygen-generating nanoparticles released around 700 ppm oxygen per day at least for 7 days. By modulating the concentration of the methacrylated gelatin, we were able to maintain the injectability of lignin composite precursors and the stiffness of lignin composites suitable for wound healing after photo-cross-linking. In situ formation of lignin composites with the oxygen-releasing nanoparticles enhanced the rate of tissue granulation, the formation of blood vessels, and the infiltration of α-smooth muscle actin+ fibroblasts into the wounds over 7 days. At 28 days after surgery, the lignin composite with oxygen-generating nanoparticles remodeled the collagen architecture, resembling the basket-weave pattern of unwounded collagen with minimal scar formation. Thus, our study shows the potential of functionalized lignin for wound-healing applications requiring balanced antioxidation and controlled release of oxygen for enhanced tissue granulation, vascularization, and maturation of collagen.

Tolerability and immunogenicity of an intranasally-administered adenovirus-vectored COVID-19 vaccine: An open-label partially-randomised ascending dose phase I trial.

BACKGROUND: Intranasal vaccination may induce protective local and systemic immune responses against respiratory pathogens. A number of intranasal SARS-CoV-2 vaccine candidates have achieved protection in pre-clinical challenge models, including ChAdOx1 nCoV-19 (AZD1222, University of Oxford / AstraZeneca). METHODS: We performed a single-centre open-label Phase I clinical trial of intranasal vaccination with ChAdOx1 nCoV-19 in healthy adults, using the existing formulation produced for intramuscular administration. Thirty SARS-CoV-2 vaccine-naïve participants were allocated to receive 5 × 109 viral particles (VP, n=6), 2 × 1010 VP (n=12), or 5 × 1010 VP (n=12). Fourteen received second intranasal doses 28 days later. A further 12 received non-study intramuscular mRNA SARS-CoV-2 vaccination between study days 22 and 46. To investigate intranasal ChAdOx1 nCoV-19 as a booster, six participants who had previously received two intramuscular doses of ChAdOx1 nCoV-19 and six who had received two intramuscular doses of BNT162b2 (Pfizer / BioNTech) were given a single intranasal dose of 5 × 1010 VP of ChAdOx1 nCoV-19. Objectives were to assess safety (primary) and mucosal antibody responses (secondary). FINDINGS: Reactogenicity was mild or moderate. Antigen-specific mucosal antibody responses to intranasal vaccination were detectable in a minority of participants, rarely exceeding levels seen after SARS-CoV-2 infection. Systemic responses to intranasal vaccination were typically weaker than after intramuscular vaccination with ChAdOx1 nCoV-19. Antigen-specific mucosal antibody was detectable in participants who received an intramuscular mRNA vaccine after intranasal vaccination. Seven participants developed symptomatic SARS-CoV-2 infection. INTERPRETATION: This formulation of intranasal ChAdOx1 nCoV-19 showed an acceptable tolerability profile but induced neither a consistent mucosal antibody response nor a strong systemic response. FUNDING: AstraZeneca.

Bullous Amyloidosis Masquerading as Pseudoporphyria.

Amyloidosis is not a singular disease but describes a group of diseases that result from abnormalities in protein folding and metabolism, leading to ß-sheet polymers and amyloid fibrils. Cutaneous involvement is common and may occur as a primary disorder or secondary to systemic disease. Bullous skin changes, however, are rare occurrences in cutaneous amyloidosis. Bullous amyloidosis presents with characteristic histopathologic, immunohistochemical, and immunofluorescence patterns, all of which allow for careful distinction from other similar diseases. Importantly, bullous amyloidosis should prompt consideration of an underlying diagnosis of a lymphoproliferative disorder. We present the case of a woman who was diagnosed with bullous amyloidosis due to multiple myeloma after an extensive workup initially suggested other bullous diseases. We highlight the importance of recognizing this rare entity to prevent delay in diagnosis and management of its underlying cause.

Mycobacterium tuberculosis subverts negative regulatory pathways in human macrophages to drive immunopathology.

Tuberculosis remains a global pandemic and drives lung matrix destruction to transmit. Whilst pathways driving inflammatory responses in macrophages have been relatively well described, negative regulatory pathways are less well defined. We hypothesised that Mycobacterium tuberculosis (Mtb) specifically targets negative regulatory pathways to augment immunopathology. Inhibition of signalling through the PI3K/AKT/mTORC1 pathway increased matrix metalloproteinase-1 (MMP-1) gene expression and secretion, a collagenase central to TB pathogenesis, and multiple pro-inflammatory cytokines. In patients with confirmed pulmonary TB, PI3Kδ expression was absent within granulomas. Furthermore, Mtb infection suppressed PI3Kδ gene expression in macrophages. Interestingly, inhibition of the MNK pathway, downstream of pro-inflammatory p38 and ERK MAPKs, also increased MMP-1 secretion, whilst suppressing secretion of TH1 cytokines. Cross-talk between the PI3K and MNK pathways was demonstrated at the level of eIF4E phosphorylation. Mtb globally suppressed the MMP-inhibitory pathways in macrophages, reducing levels of mRNAs encoding PI3Kδ, mTORC-1 and MNK-1 via upregulation of miRNAs. Therefore, Mtb disrupts negative regulatory pathways at multiple levels in macrophages to drive a tissue-destructive phenotype that facilitates transmission.

Hypoxia and tissue destruction in pulmonary TB.

BACKGROUND: It is unknown whether lesions in human TB are hypoxic or whether this influences disease pathology. Human TB is characterised by extensive lung destruction driven by host matrix metalloproteinases (MMPs), particularly collagenases such as matrix metalloproteinase-1 (MMP-1). METHODS: We investigated tissue hypoxia in five patients with PET imaging using the tracer [18F]-fluoromisonidazole ([18F]FMISO) and by immunohistochemistry. We studied the regulation of MMP secretion in primary human cell culture model systems in normoxia, hypoxia, chemical hypoxia and by small interfering RNA (siRNA) inhibition. RESULTS: [18F]FMISO accumulated in regions of TB consolidation and around pulmonary cavities, demonstrating for the first time severe tissue hypoxia in man. Patlak analysis of dynamic PET data showed heterogeneous levels of hypoxia within and between patients. In Mycobacterium tuberculosis (M.tb)-infected human macrophages, hypoxia (1% pO2) upregulated MMP-1 gene expression 170-fold, driving secretion and caseinolytic activity. Dimethyloxalyl glycine (DMOG), a small molecule inhibitor which stabilises the transcription factor hypoxia-inducible factor (HIF)-1α, similarly upregulated MMP-1. Hypoxia did not affect mycobacterial replication. Hypoxia increased MMP-1 expression in primary respiratory epithelial cells via intercellular networks regulated by TB. HIF-1α and NF-κB regulated increased MMP-1 activity in hypoxia. Furthermore, M.tb infection drove HIF-1α accumulation even in normoxia. In human TB lung biopsies, epithelioid macrophages and multinucleate giant cells express HIF-1α. HIF-1α blockade, including by targeted siRNA, inhibited TB-driven MMP-1 gene expression and secretion. CONCLUSIONS: Human TB lesions are severely hypoxic and M.tb drives HIF-1α accumulation, synergistically increasing collagenase activity which will lead to lung destruction and cavitation.

G6PD testing in support of treatment and elimination of malaria: recommendations for evaluation of G6PD tests.

Malaria elimination will be possible only with serious attempts to address asymptomatic infection and chronic infection by both Plasmodium falciparum and Plasmodium vivax. Currently available drugs that can completely clear a human of P. vivax (known as "radical cure"), and that can reduce transmission of malaria parasites, are those in the 8-aminoquinoline drug family, such as primaquine. Unfortunately, people with glucose-6-phosphate dehydrogenase (G6PD) deficiency risk having severe adverse reactions if exposed to these drugs at certain doses. G6PD deficiency is the most common human enzyme defect, affecting approximately 400 million people worldwide.Scaling up radical cure regimens will require testing for G6PD deficiency, at two levels: 1) the individual level to ensure safe case management, and 2) the population level to understand the risk in the local population to guide Plasmodium vivax treatment policy. Several technical and operational knowledge gaps must be addressed to expand access to G6PD deficiency testing and to ensure that a patient's G6PD status is known before deciding to administer an 8-aminoquinoline-based drug.In this report from a stakeholder meeting held in Thailand on October 4 and 5, 2012, G6PD testing in support of radical cure is discussed in detail. The focus is on challenges to the development and evaluation of G6PD diagnostic tests, and on challenges related to the operational aspects of implementing G6PD testing in support of radical cure. The report also describes recommendations for evaluation of diagnostic tests for G6PD deficiency in support of radical cure.

Amyopathic dermatomyositis complicated by pneumomediastinum.

Dermatomyositis is an inflammatory disease of unclear etiology with characteristic cutaneous and musculoskeletal findings. Amyopathic dermatomyositis is a subtype without musculoskeletal involvement. Many cases of dermatomyositis are associated with underlying malignancy, but pulmonary manifestations can also be seen, the most common of which is interstitial lung disease. Pneumomediastinum is a rare complication that is important for clinicians to recognize, as it may be fatal if left untreated. The sudden onset of facial edema and shortness of breath in the setting of dermatomyositis should raise the suspicion of this condition.

Levamisole-induced Wegener's granulomatosis following contaminated cocaine abuse.

A 44-year-old woman with a medical history of chronic pain syndrome presented with a 3-day history of a painful "rash" that started on her face and spread to her legs. Further history revealed that she recently started a new medication, varenicline, 7 weeks prior to admission and had a long-standing history of intranasal cocaine use. Review of systems was significant for rhinitis, nasal congestion, joint pain, and a febrile episode 2 days prior to admission. Physical examination revealed centrally violaceous, tender, stellate, and retiform purpuric patches and plaques on her extremities, nasal dorsum, and cheeks. Approximately 1.0-centimeter tender purpuric nodules were noted on her bilateral second proximal interphalangeal joints. She was afebrile. Initial laboratory data revealed a mild leukopenia, normal serum urea nitrogen and creatinine without hematuria, and an elevated erythrocyte sedimentation rate. Further analysis showed a normal complement level, negative antinuclear antibody, human immunodeficiency virus, rapid plasma reagin, and hepatitis panel. Trace cryoglobenemia and a positive anti-streptolysin O were noted, along with a positive antineutrophil cytoplasmic antibody (c-ANCA) (> 8.0 U) and perinuclear antineutrophil cytoplasmic antibodies, or p-ANCA (1.5 U). The hypercoagulable workup was negative. A skin biopsy taken from the left thigh was consistent with leukocytoclastic vasculitis. After several weeks of high-dose oral prednisone taper, the patient's symptoms improved, but flared upon discontinuation. On follow-up, she admitted to frequent relapses of cocaine abuse and had developed tender purpuric plaques on her nose, ears, and extremities, some with ulcerations (Figure 1 and Figure 2). She also had significant edema and joint pain that limited her ambulation. Further evaluation revealed normal chest x-ray results; however, computed tomography of her sinuses demonstrated thickened maxillary sinuses consistent with subacute/ chronic sinusitis. She also developed hematuria. Mass spectrometry analysis ofhair and urine samples tested positive for cocaine and levamisole. A presumptive diagnosis of levamisole-induced Wegener's vasculitis was made. She was restarted on high-dose prednisone and methotrexate with improvement and advised to discontinue cocaine use, so as to avoid exposure to both substances.

Mycobacterium tuberculosis-infected human monocytes down-regulate microglial MMP-2 secretion in CNS tuberculosis via TNFα, NFκB, p38 and caspase 8 dependent pathways.

Tuberculosis (TB) of the central nervous system (CNS) is a deadly disease characterized by extensive tissue destruction, driven by molecules such as Matrix Metalloproteinase-2 (MMP-2) which targets CNS-specific substrates. In a simplified cellular model of CNS TB, we demonstrated that conditioned medium from Mycobacterium tuberculosis-infected primary human monocytes (CoMTb), but not direct infection, unexpectedly down-regulates constitutive microglial MMP-2 gene expression and secretion by 72.8% at 24 hours, sustained up to 96 hours (P < 0.01), dependent upon TNF-α. In human CNS TB brain biopsies but not controls the p38 pathway was activated in microglia/macrophages. Inhibition of the p38 MAP kinase pathway resulted in a 228% increase in MMP-2 secretion (P < 0.01). In contrast ERK MAP kinase inhibition further decreased MMP-2 secretion by 76.6% (P < 0.05). Inhibition of the NFκB pathway resulted in 301% higher MMP-2 secretion than CoMTb alone (P < 0.01). Caspase 8 restored MMP-2 secretion to basal levels. However, this caspase-dependent regulation of MMP-2 was independent of p38 and NFκB pathways; p38 phosphorylation was increased and p50/p65 NFκB nuclear trafficking unaffected by caspase 8 inhibition. In summary, suppression of microglial MMP-2 secretion by M.tb-infected monocyte-dependent networks paradoxically involves the pro-inflammatory mediators TNF-α, p38 MAP kinase and NFκB in addition to a novel caspase 8-dependent pathway.

Mycobacterium tuberculosis upregulates microglial matrix metalloproteinase-1 and -3 expression and secretion via NF-kappaB- and Activator Protein-1-dependent monocyte networks.

Inflammatory tissue destruction is central to pathology in CNS tuberculosis (TB). We hypothesized that microglial-derived matrix metalloproteinases (MMPs) have a key role in driving such damage. Analysis of all of the MMPs demonstrated that conditioned medium from Mycobacterium tuberculosis-infected human monocytes (CoMTb) stimulated greater MMP-1, -3, and -9 gene expression in human microglial cells than direct infection. In patients with CNS TB, MMP-1/-3 immunoreactivity was demonstrated in the center of brain granulomas. Concurrently, CoMTb decreased expression of the inhibitors, tissue inhibitor of metalloproteinase-2, -3, and -4. MMP-1/-3 secretion was significantly inhibited by dexamethasone, which reduces mortality in CNS TB. Surface-enhanced laser desorption ionization time-of-flight analysis of CoMTb showed that TNF-alpha and IL-1beta are necessary but not sufficient for upregulating MMP-1 secretion and act synergistically to drive MMP-3 secretion. Chemical inhibition and promoter-reporter analyses showed that NF-kappaB and AP-1 c-Jun/FosB heterodimers regulate CoMTb-induced MMP-1/-3 secretion. Furthermore, NF-kappaB p65 and AP-1 c-Jun subunits were upregulated in biopsy granulomas from patients with cerebral TB. In summary, functionally unopposed, network-dependent microglial MMP-1/-3 gene expression and secretion regulated by NF-kappaB and AP-1 subunits were demonstrated in vitro and, for the first time, in CNS TB patients. Dexamethasone suppression of MMP-1/-3 gene expression provides a novel mechanism explaining the benefit of steroid therapy in these patients.

Analysis of matrix metalloproteinase secretion by macrophages.

Matrix metalloproteinases (MMPs) are zinc-dependent proteases whose physiological roles include control of leukocyte migration. They are implicated in tissue destruction in inflammatory and infectious diseases. MMPs are not only capable of degrading all components of the extracellular matrix, but they also can modulate the immune response by cleaving cytokines and chemokines to alter their activity. Macrophages secrete a broad range of MMPs and represent a key source of MMPs in inflammatory lesions such as granulomas. Zymography is substrate-based gel electrophoresis that allows direct visualization of MMP activity. Here we describe measurement of MMP secretion from macrophages focusing on quantitative zymography. We also discuss complementary methods that should be used in parallel with zymography. The ability to analyze and quantify MMP secretion by macrophages offers an additional window through which to understand the contributions of macrophages to a wide variety of infectious, inflammatory, and immunologic disorders.

Matrix metalloproteinase-1 is regulated in tuberculosis by a p38 MAPK-dependent, p-aminosalicylic acid-sensitive signaling cascade.

Mycobacterium tuberculosis (M. tb) must cause lung disease to spread. Matrix metalloproteinases (MMPs) degrade the extracellular matrix and are implicated in tuberculosis-driven tissue destruction. We investigated signaling pathways regulating macrophage MMP-1 and -7 in human pulmonary tuberculosis and examine the hypothesis that the antimycobacterial drug p-aminosalicylic acid acts by inhibiting such pathways. In primary human macrophages, M. tb up-regulates gene expression and secretion of MMP-1 (interstitial collagenase) and MMP-7 (matrilysin). In tuberculosis patients, immunohistochemical analysis of lung biopsies demonstrates that p38 MAPK is phosphorylated in macrophages surrounding granulomas. In vitro, M. tb drives p38 phosphorylation. p38 inhibition suppresses M. tb-dependent MMP-1 secretion by 57.8% and concurrently increases secretion of its specific inhibitor TIMP-1 by 243.7%, demonstrating that p38 activity regulates matrix degradation by macrophages. p38 signals downstream to the cyclooxygenase 2/PGE(2) pathway. p-Aminosalicyclic acid, an agent used to treat drug-resistant tuberculosis, inhibits M. tb-driven MMP-1 but not MMP-7 gene expression and secretion. PAS acts by blocking PGE(2) production without affecting M. tb growth. In summary, p-aminosalicyclic acid decreases MMP-1 activity by inhibiting a p38 MAPK-PG signaling cascade, suggesting that this pathway is a therapeutic target to reduce inflammatory tissue destruction in tuberculosis.

Human mitochondrial oxidative capacity is acutely impaired after burn trauma.

BACKGROUND: Mitochondrial proteins and genes are damaged after burn injury in animals and are assessed in human burn patients in this study. METHODS: The rates of maximal muscle mitochondrial oxidative capacity (adenosine triphosphate production) and uncoupled oxidation (heat production) for both palmitate and pyruvate were measured in muscle biopsies from 40 children sustaining burns on more than 40% of their body surface area and from 13 healthy children controls. RESULTS: Maximal mitochondrial oxidation of pyruvate and palmitate were reduced in burn patients compared with controls (4.0 +/- .2:1.9 +/- .1 micromol O2/citrate synthase activity/mg protein/min pyruvate; control:burn; P < .001 and 3.0 +/- .1: .9 +/- .03 micromol O2/citrate synthase activity/mg protein/min palmityl CoA; control:burn; P = .003). Uncoupled oxidation was the same between groups. CONCLUSIONS: The maximal coupled mitochondrial oxidative capacity is severely impaired after burn injury, although there are no alterations in the rate of uncoupled oxidative capacity. It may be that the ratio of these indicates that a larger portion of energy production in trauma patients is wasted through uncoupling, rather than used for healing.

Ductal prostate cancer: contemporary management and outcomes.

OBJECTIVES: To evaluate contemporary management and outcomes of ductal prostate cancer (PCA). MATERIALS AND METHODS: We reviewed all patients with ductal PCA and at least 6 months of follow-up seen at UTMB from 1990 to 2005, which comprised 17 patients (mean age: 67.7 years, range 55-87). At time of diagnosis, 11 patients had localized disease (Group 1) and 6 patients had distant metastasis (Group 2). RESULTS: Treatment of Group 1 patients included radiation and endocrine treatment for at least 2 years (n = 7), radiation alone (n = 2), and radical surgery (n = 2). At a mean follow-up of 3.6 years (r = 1-12 years) 8 patients (67.7%) remained free of recurrence, 1 patient had biochemical recurrence alone, 1 patient had recurrence in the anterior urethra, and the other had progression with metastasis to the brain and subsequent death. In addition to metastasis to regional/distant lymph nodes and bone in Group 2, metastatic sites included brain (n = 1), peritoneum (n = 1), and lung (n = 1). Mean follow-up was 2.3 years (r = 8 months to 4 years). All patients received androgen deprivation. One patient had progression of disease despite lack of biochemical recurrence and is alive at 2.5 years. One patient died from other causes while the 4 remaining patients are in remission at last follow-up. CONCLUSIONS: Contemporary management of localized ductal PCA with radiation and endocrine therapy yields adequate disease-free survival. Metastatic sites include brain, lung, peritoneum, and anterior urethra, and most patients respond well to endocrine treatment.

Synergistic up-regulation of epithelial cell matrix metalloproteinase-9 secretion in tuberculosis.

Mycobacterium tuberculosis (MTb) kills approximately 2 million people each year. MTb must drive host tissue destruction to disseminate and also to cause pulmonary cavitation. Matrix metalloproteinase-9 (MMP-9, gelatinase B) is implicated in this Tb-related immunopathology. We demonstrate that conditioned media from MTb-infected monocytes (CoMTb), but not direct infection with MTb, up-regulates MMP-9 gene expression and secretion from primary human bronchial epithelial cells (NHBE). MMP-9 secretion was increased 8.7-fold by CoMTb (P < 0.05) as assayed by gelatin zymography. A549 and 16HBE14o epithelial cell MMP secretion was significantly less than primary NHBE secretion. MMP-9 secretion was decreased 53.2% by inhibition of the p38 mitogen-activated protein kinase (MAPK) by SB203580 (P < 0.01) and 48.3% by inhibition of extracellular signal-regulated kinase with PD98059 (P < 0.05). MMP-9 secretion was prostaglandin independent. TNF-alpha was necessary but not sufficient for MMP-9 up-regulation by the monocyte-epithelial cell network. Soluble factors derived from Tb culture synergized with TNF-alpha to increase MMP-9 secretion by NHBE 6-fold (P < 0.01 compared with either stimulus alone). Together, these data reveal a new mechanism by which host- and pathogen-derived factors act together in MTb infection to drive MAPK-dependent MMP-9 secretion from respiratory epithelial cells.

Swine cysticercosis hotspots surrounding Taenia solium tapeworm carriers.

We estimated the Taenia solium swine cysticercosis risk gradient surrounding tapeworm carriers in seven rural communities in Peru. At baseline, the prevalences of taeniasis by microscopy and swine cysticercosis by serology were 1.2% (11 of 898) and 30.8% (280 of 908), respectively. The four-month cumulative seroincidence was 9.8% (30 of 307). The unadjusted swine seroprevalence and seroincidence rates increased exponentially by 12.0% (95% confidence [CI] = 9.7-14.3%) and 32.8% (95% CI = 25.0-41.0%), respectively when distance to carriers decreased by half. Swine seroprevalence was 18.4% at > 500 meters from a carrier, 36.5% between 51 and 500 meters, and 68.9% within 50 meters (P < 0.001). Swine seroincidence also displayed a strong gradient near tapeworm carriers (3.8%, 12.2%, and 44.0%; P < 0.001). Within 50 meters, swine seroprevalence appeared unaffected if the owners harbored tapeworms, although pigs owned by a tapeworm carrier had a four times higher seroincidence compared with other pigs (P = 0.005). In rural areas, swine cysticercosis occurs in high-risk hotspots around carriers where control interventions could be delivered.

Monocyte-astrocyte networks regulate matrix metalloproteinase gene expression and secretion in central nervous system tuberculosis in vitro and in vivo.

CNS tuberculosis (CNS-TB) is the most deadly form of tuberculous disease accounting for 10% of clinical cases. CNS-TB is characterized by extensive tissue destruction, in which matrix metalloproteinases (MMPs) may play a critical role. We investigated the hypothesis that Mycobacterium tuberculosis activates monocyte-astrocyte networks increasing the activity of key MMPs. We examined the expression of all human MMPs and the tissue inhibitors of metalloproteinases (TIMPs) in human astrocytes stimulated by conditioned medium from M. tuberculosis-infected monocytes (CoMTB). Real-time RT-PCR showed that gene expression of MMP-1, -2, -3, -7, and -9 was increased (p < 0.05). MMP-9 secretion was significantly up-regulated at 24 h and increased over 120 h (p < 0.01). MMP-1, -3, and -7 secretion was not detected. Secretion of MMP-2 was constitutive and unaffected by CoMTB. Astrocyte gene expression and secretion of TIMP-1 was not affected by CoMTB although TIMP-2 secretion increased 3-fold at 120 h. Immunohistochemical analysis of human brain biopsies confirmed that astrocyte MMP-9 secretion is a predominant feature in CNS-TB in vivo. Dexamethasone inhibited astrocyte MMP-9, but not TIMP-1/2 secretion in response to CoMTB. CoMTB stimulated the nuclear translocation of NF-kappaB, inducing a 6-fold increase in nuclear p65 and a 2-fold increase in nuclear p50. This was associated with degradation of IkappaBalpha and beta within 30 min, persisting for 24 h. In summary, networks active between monocytes and astrocytes regulate MMP-9 activity in tuberculosis and astrocytes are a major source of MMP-9 in CNS-TB. Astrocytes may contribute to a matrix degrading environment within the CNS and subsequent morbidity and mortality.