Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0032285 (pneumonia)
 54,520 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We evaluated 50 consecutive patients with acute ischemic stroke to assess the prevalence of systemic infection preceding the neurological event. We analyzed the immunohematologic characteristics of patients with and without signs and/or symptoms of a preceding infectious process. Patients were examined less than or equal to 7 days after cerebral infarction and evaluated for fibrinogen, anticardiolipin antibodies, fibrin D-dimer (a fragment of cross-linked fibrin), plasminogen activator inhibitor-1, and protein S. Of the 50 patients, 17 had symptoms of infection beginning less than or equal to 1 month before the stroke (11 had upper respiratory tract infections, three urinary tract infections, two subacute bacterial endocarditis, and one pneumonia). Compared with patients without infection, patients with infection had significant increases in fibrin D-dimer concentration (5.3 +/- 1.1 versus 4.7 +/- 0.9 log-transformed ng/ml, p less than 0.05) and cardiolipin immunoreactivity, IgG isotype (1.8 +/- 1.3 versus 1.1 +/- 0.9 log-transformed phospholipid units, p less than 0.04), and, when studied less than or equal to 2 days after the stroke, increased fibrinogen levels (459 +/- 126 versus 360 +/- 94 mg/dl, p less than 0.05). In conclusion, infection-associated cerebral infarction is common and is associated with substantial immunohematologic abnormalities.
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PMID:Immunohematologic characteristics of infection-associated cerebral infarction. 148 66

Pneumonia is the most common serious complication of varicella infection in adults. A variety of thrombotic complications including purpura fulminans and disseminated intravascular coagulation have been reported in children with varicella but not in adults. Two men with varicella pneumonia who had profound lower extremity ischemia caused by thrombosis of the profunda femoris and tibial arteries are reported. Both patients had free protein S deficiency and vascular thrombosis in association with varicella pneumonia without overt evidence of disseminated intravascular coagulation or purpura fulminans. Antiphospholipid immunoglobulin G and immunoglobulin M antibodies were present in one, whereas the other had evidence of the lupus anticoagulant. The proposed pathogenesis and management options including intraarterial thrombolytic therapy with urokinase and the need for long-term anticoagulation are discussed.
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PMID:Spontaneous tibial artery thrombosis associated with varicella pneumonia and free protein S deficiency. 954 47

The thrombomodulin-protein C-protein S (TM-PC-PS) pathway exerts anticoagulant and anti-inflammatory effects. We investigated the role of TM in the pulmonary immune response in vivo by the use of mice with a mutation in the TM gene (TM(pro/pro)) that was earlier found to result in a minimal capacity for activated PC (APC) generation in the circulation. We here demonstrate that TM(pro/pro) mice also display a strongly reduced capacity to produce APC in the alveolar compartment upon intrapulmonary delivery of PC and thrombin. We monitored procoagulant and inflammatory changes in the lung during Gram-positive (Streptococcus pneumoniae) and Gram-negative (Klebsiella pneumoniae) pneumonia and after local administration of lipopolysaccharide (LPS). Bacterial pneumonia was associated with fibrin(ogen) depositions in the lung that colocalized with inflammatory infiltrates. LPS also induced a rise in thrombin-antithrombin complexes in bronchoalveolar lavage fluid. These pulmonary procoagulant responses were unaltered in TM(pro/pro) mice, except for enhanced fibrin(ogen) deposition during pneumococcal pneumonia. In addition, TM(pro/pro) mice displayed unchanged antibacterial defense, neutrophil recruitment, and cytokine/chemokine levels. These data suggest that the capacity of TM to generate APC does not play a role of importance in the pulmonary response to respiratory pathogens or LPS.
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PMID:Thrombomodulin mutant mice with a strongly reduced capacity to generate activated protein C have an unaltered pulmonary immune response to respiratory pathogens and lipopolysaccharide. 1459 28

The incidence of varicella zoster in adults is increasing, and may be associated with a number of significant complications. An adult male presented with varicella zoster complicated by pneumonitis and thrombosis, leading to a below-knee amputation. Thrombosis with varicella zoster has been associated with vasculitis and free protein S deficiency. Other microthrombotic complications, such as purpura fulminans, are more common in children. Current treatment recommendations include acetaminophen (paracetamol) and lotions for symptomatic treatment. Intravenous acyclovir is recommended in the treatment of complicated varicella zoster, although it has not been shown to reduce the incidence of complications.
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PMID:Thrombosis associated with varicella zoster in an adult. 1939 62

A 32-year-old man presented overnight to the accident and emergency unit with mild breathlessness on exertion. He was found to be hypoxic on room air and his chest x-ray revealed areas of patchy lung consolidation. He was given intravenous antibiotics for presumed community-acquired pneumonia. Unfortunately his condition deteriorated and he remained significantly hypoxic despite high-flow oxygen with ECG evidence of right heart strain. Further questioning revealed a history of protein S deficiency and a strong family history of venous thromboembolic disease. An urgent CT pulmonary angiogram showed an evidence of massive pulmonary embolism and the patient was successfully thrombolysed.
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PMID:Massive pulmonary embolism and thrombophilia. 2334 3

Introduction Human immunodeficiency virus (HIV) patients are at risk of developing thrombosis than general population. There are several intersecting mechanisms associated with HIV infection and antiviral therapy that are emerging, which may lead to vasculopathy and hypercoagulability in these patients. Methods We analyzed the HIV patients who followed up with our Vascular Medicine outpatient clinic with venous thromboembolism (VTE) over the past 3 years and followed them prospectively. The patients included were those who had minimum, regular follow-up of 3 months, with a Doppler scan in the beginning and last follow-up. Patients were analyzed for age, gender, race, site of thrombosis, coagulation factors, lipid panel, type of antiretroviral treatment, past or present history of infections or malignancy, CD4 absolute and helper cell counts at the beginning of thrombosis, response to treatment and outcome. Patients with HIV with arterial thrombosis were excluded. Results A total of eight patients were analyzed. The mean age was 49.87 years (range, 38-58 years). All were male patients with six patients having lower limb thrombosis, one patient with upper limb thrombosis related to peripheral inserted central catheter (PICC), and one patient had pulmonary embolism with no deep vein thrombosis. Most common venous thrombosis was popliteal vein thrombosis, followed by common femoral, superficial femoral and external iliac thrombosis. Two patients had deficiency of protein S, two had high homocysteine levels, one had deficiency of antithrombin 3, and one had increase in anticardiolipin Immunoglobulin antibody. All patients were taking nucleoside and nonnucleoside inhibitors but only two patients were taking protease inhibitors. There was history of lymphoma in one and nonsmall cell lung carcinoma in one patient. Three patients had past history of tuberculosis and one of these patients also had pneumocystis carinii pneumonia. The mean absolute CD4 counts were 383.25 cells/UL (range, 103-908 cells/UL) and helper CD4 counts were 22.5 cells/UL (range, 12-45 cells/UL). All were anticoagulated with warfarin or enoxaparin. There was complete resolution of deep vein thrombosis in two patients (one with PICC line thrombosis in 3 months and other with popliteal vein thrombosis in 1 year). There was extension of clot in one patient and no resolution in others. Seven patients are still alive and on regular follow-up. Conclusion Thrombosis in HIV patients is seen more commonly in middle aged, community ambulant male patients. Left lower limb involvement with involvement of popliteal vein is most common. Deficiency of protein S and hyperhomocystenaemia were noted in these patients. Most of these patients did not respond to therapeutic anticoagulation, but the extension of the thrombosis was prevented in majority of cases.
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PMID:Risk of Venous Thromboembolism in Patients Infected with HIV: A Cohort Study. 2443 91

Influenza infections often cause pneumonia, but there is limited information on thrombotic microangiopathy (TMA) in these circumstances. We report the case of an 11-year-old boy who developed TMA during the acute phase of H1N1 influenza. Plasma von Willebrand factor (VWF) was elevated, whereas a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) activity was mildly reduced in the absence of ADAMTS13-neutralizing autoantibody, resulting in low ratio of ADAMTS13 to VWF. The patient was treated intensively, including plasma exchange, and he recovered from the TMA. He developed pulmonary embolism (PE), however, after removal of the central venous catheter. The findings suggested that influenza-associated cytokines enhanced the release of unusually large VWF multimers from vascular endothelial cells and promoted the formation of platelet thrombi and TMA. Subsequent analysis further indicated the presence of familial protein S deficiency, and it seemed likely that the PE was more related to this heterozygous protein S defect.
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PMID:Influenza-associated thrombotic microangiopathy with unbalanced von Willebrand factor and a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 levels in a heterozygous protein S-deficient boy. 2743 11

The year 2020 has seen a major and sustained outbreak of a novel betacoronavirus (severe acute respiratory syndrome (SARS)-coronavirus (CoV)-2) infection that causes fever, severe respiratory illness and pneumonia, a disease called COVID-19. At the time of writing, the death toll was greater than 120 000 worldwide with more than 2 million documented infections. The genome of the CoV encodes a number of structural proteins that facilitate cellular entry and assembly of virions, of which the spike protein S appears to be critical for cellular entry. The spike protein guides the virus to attach to the host cell. The spike protein contains a receptor-binding domain (RBD), a fusion domain and a transmembrane domain. The RBD of spike protein S binds to Angiotensin Converting Enzyme 2 (ACE2) to initiate cellular entry. The spike protein of SARS-CoV-2 shows more than 90% amino acid similarity to the pangolin and bat CoVs and these also use ACE2 as a receptor. Binding of the spike protein to ACE2 exposes the cleavage sites to cellular proteases. Cleavage of the spike protein by transmembrane protease serine 2 and other cellular proteases initiates fusion and endocytosis. The spike protein contains an addition furin cleavage site that may allow it to be 'preactivated' and highly infectious after replication. The fundamental role of the spike protein in infectivity suggests that it is an important target for vaccine development, blocking therapy with antibodies and diagnostic antigen-based tests. This review briefly outlines the structure and function of the 2019 novel CoV/SARS-CoV-2 spike protein S.
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PMID:Gene of the month: the 2019-nCoV/SARS-CoV-2 novel coronavirus spike protein. 3237 14

Over the past years, several zoonotic viruses have crossed the species barrier into humans and have been causing outbreaks of severe, and often fatal, respiratory illness. The 21st century has seen the worldwide spread of three recognized coronaviruses (CoVs) which can cause pneumonia and severe acute respiratory symptoms (SARSs), SARS, MERS, and recently SARS-CoV-2. Herein, it is raising concerns about the dissemination of another new and highly lethal pandemic outbreak. Preparing for a pandemic outbreak involves a great deal of awareness necessary to stop initial outbreaks, through recognizing the molecular mechanisms underlying virus transmission and pathogenicity. CoV spike protein S is the key determinant of host tropism and viral pathogenicity which can undergo variations and makes the CoV a highly pathogenic and diffusible virus capable of sustained human-to-human transmission and spread easily. The three mentioned CoVs exhibit some similarities in S protein whereby constitute a promising target for the development of prophylactics and therapeutics in the future.
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PMID:Molecular Basis for Pathogenicity of Human Coronaviruses. 3276 13

Coronavirus disease 2019 (Covid-19), caused by severe acute respiratory syndrome coronavirus (SARS-CoV)-2, exerts far-reaching effects on public health and socio-economic welfare. The majority of infected individuals have mild to moderate symptoms, but a significant proportion develops respiratory failure due to pneumonia. Thrombosis is another frequent manifestation of Covid-19 that contributes to poor outcomes. Vitamin K plays a crucial role in the activation of both pro- and anticlotting factors in the liver and the activation of extrahepatically synthesised protein S which seems to be important in local thrombosis prevention. However, the role of vitamin K extends beyond coagulation. Matrix Gla protein (MGP) is a vitamin K-dependent inhibitor of soft tissue calcification and elastic fibre degradation. Severe extrahepatic vitamin K insufficiency was recently demonstrated in Covid-19 patients, with high inactive MGP levels correlating with elastic fibre degradation rates. This suggests that insufficient vitamin K-dependent MGP activation leaves elastic fibres unprotected against SARS-CoV-2-induced proteolysis. In contrast to MGP, Covid-19 patients have normal levels of activated factor II, in line with previous observations that vitamin K is preferentially transported to the liver for activation of procoagulant factors. We therefore expect that vitamin K-dependent endothelial protein S activation is also compromised, which would be compatible with enhanced thrombogenicity. Taking these data together, we propose a mechanism of pneumonia-induced vitamin K depletion, leading to a decrease in activated MGP and protein S, aggravating pulmonary damage and coagulopathy, respectively. Intervention trials should be conducted to assess whether vitamin K administration plays a role in the prevention and treatment of severe Covid-19.
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PMID:Vitamin K metabolism as the potential missing link between lung damage and thromboembolism in Coronavirus disease 2019. 3302 81


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