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Schwenk HT, Khan A, Kohlman K, Bertaina A, Cho S, Montoya JG, Contopoulos-Ioannidis DG. Toxoplasmosis in Pediatric Hematopoietic Stem Cell Transplantation Patients. Transplant Cell Ther 2020; 27:292-300. [PMID: 33840441 DOI: 10.1016/j.jtct.2020.11.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 10/05/2020] [Accepted: 11/02/2020] [Indexed: 11/18/2022]
Abstract
Infection due to the protozoa Toxoplasma gondii can be life-threatening in hematopoietic stem cell transplantation (HSCT) recipients. Most cases of toxoplasmosis in HSCT recipients result from reactivation of latent infection in individuals who were Toxoplasma-seropositive before transplantation and did not receive appropriate prophylaxis. Pretransplantation screening with Toxoplasma IgG and IgM antibodies is suggested for all allogeneic HSCT recipients and their donors and all autologous HSCT recipients. Prevention of toxoplasmosis in T. gondii-seropositive HSCT recipients requires primary prophylaxis, preemptive screening, or both. Trimethoprim-sulfamethoxazole (TMP-SMX) is the preferred agent for Toxoplasma prophylaxis and should be continued for 6 months or until the patient is no longer receiving immunosuppression, whichever is longer, assuming that immune reconstitution has occurred. Preemptive weekly screening with whole blood Toxoplasma PCR should be considered for seropositive HSCT recipients if prophylaxis cannot be given or if prophylaxis other than TMP-SMX is used. The signs, symptoms, and radiographic findings of toxoplasmosis in HSCT recipients can be nonspecific, and the diagnosis requires a high degree of suspicion. Common presentations include fever, encephalopathy with mental status changes or seizures, and pneumonia. A Toxoplasma PCR analysis from whole blood (and other body fluids/tissues according to clinical symptoms) should be obtained in patients in whom there is a concern for toxoplasmosis. Treatment with oral pyrimethamine, sulfadiazine, and leucovorin for at least 6 weeks is the first-line therapy and should be followed by secondary prophylaxis. In this article, we review the published literature regarding the epidemiology, clinical presentation, treatment, and prevention of toxoplasmosis in HSCT recipients.
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Affiliation(s)
- Hayden T Schwenk
- Lucile Packard Children's Hospital Stanford, Palo Alto, California; Division of Infectious Diseases, Department of Pediatrics, Stanford University School of Medicine, Stanford, California.
| | - Aslam Khan
- Lucile Packard Children's Hospital Stanford, Palo Alto, California; Division of Infectious Diseases, Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| | - Krystal Kohlman
- Lucile Packard Children's Hospital Stanford, Palo Alto, California
| | - Alice Bertaina
- Lucile Packard Children's Hospital Stanford, Palo Alto, California; Division of Stem Cell Transplantation and Regenerative Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| | - Stephanie Cho
- Community Health and Prevention Research Master's Graduate Program, Stanford University School of Medicine, Stanford, California
| | - Jose G Montoya
- Dr Jack S. Remington Laboratory for Specialty Diagnostics, Palo Alto Medical Foundation, Palo Alto, California
| | - Despina G Contopoulos-Ioannidis
- Lucile Packard Children's Hospital Stanford, Palo Alto, California; Division of Infectious Diseases, Department of Pediatrics, Stanford University School of Medicine, Stanford, California; Dr Jack S. Remington Laboratory for Specialty Diagnostics, Palo Alto Medical Foundation, Palo Alto, California
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Al-Horani RA, Kar S. Potential Anti-SARS-CoV-2 Therapeutics That Target the Post-Entry Stages of the Viral Life Cycle: A Comprehensive Review. Viruses 2020; 12:E1092. [PMID: 32993173 PMCID: PMC7600245 DOI: 10.3390/v12101092] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 09/08/2020] [Accepted: 09/23/2020] [Indexed: 02/06/2023] Open
Abstract
The coronavirus disease-2019 (COVID-19) pandemic continues to challenge health care systems around the world. Scientists and pharmaceutical companies have promptly responded by advancing potential therapeutics into clinical trials at an exponential rate. Initial encouraging results have been realized using remdesivir and dexamethasone. Yet, the research continues so as to identify better clinically relevant therapeutics that act either as prophylactics to prevent the infection or as treatments to limit the severity of COVID-19 and substantially decrease the mortality rate. Previously, we reviewed the potential therapeutics in clinical trials that block the early stage of the viral life cycle. In this review, we summarize potential anti-COVID-19 therapeutics that block/inhibit the post-entry stages of the viral life cycle. The review presents not only the chemical structures and mechanisms of the potential therapeutics under clinical investigation, i.e., listed in clinicaltrials.gov, but it also describes the relevant results of clinical trials. Their anti-inflammatory/immune-modulatory effects are also described. The reviewed therapeutics include small molecules, polypeptides, and monoclonal antibodies. At the molecular level, the therapeutics target viral proteins or processes that facilitate the post-entry stages of the viral infection. Frequent targets are the viral RNA-dependent RNA polymerase (RdRp) and the viral proteases such as papain-like protease (PLpro) and main protease (Mpro). Overall, we aim at presenting up-to-date details of anti-COVID-19 therapeutics so as to catalyze their potential effective use in fighting the pandemic.
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Affiliation(s)
- Rami A. Al-Horani
- Division of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans, LA 70125, USA;
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Mishra R, Paliwal S, Agarwal A, Sharma S, Paliwal S. Discovery of a potent broad spectrum antimicrobial agent through pharmacophore modeling, virtual screening, in vitro antimicrobial evaluation and gastrointestinal permeation studies. Med Chem Res 2015. [DOI: 10.1007/s00044-015-1445-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Guay D. Update on clindamycin in the management of bacterial, fungal and protozoal infections. Expert Opin Pharmacother 2007; 8:2401-44. [PMID: 17927492 DOI: 10.1517/14656566.8.14.2401] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Lincomycin and clindamycin are the only members of the relatively small lincosamide antimicrobial class marketed for use in humans. This paper only reviews data regarding clindamycin, with an emphasis on data published over the last decade. Clindamycin exhibits a broad spectrum of antimicrobial activity, including Gram-positive aerobes/anaerobes, Gram-negative anaerobes and select protozoa (Toxoplasma gondii, Plasmodium falciparum, Babesia spp.) and fungi (Pneumocystis jiroveci). It still enjoys use in the therapy and prophylaxis of a large number of bacterial, protozoal and fungal infections, despite > 40 years of clinical use. However, the spectre of resistance by an increasing number of microorganisms is beginning to cast a shadow over the future use of this valuable agent. With the emergence and spread of infections due to community-acquired methicillin-resistant Staphylococci (for which clindamycin is a first-line agent), it is hoped that the issues of resistance can be mitigated and the use of clindamycin extended for at least the foreseeable future.
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Affiliation(s)
- David Guay
- University of Minnesota, College of Pharmacy, Weaver-Densford Hall 7-148, 308 Harvard Street SE, Minneapolis, MN 55455, USA.
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Mattioni BE, Jurs PC. Prediction of dihydrofolate reductase inhibition and selectivity using computational neural networks and linear discriminant analysis. J Mol Graph Model 2003; 21:391-419. [PMID: 12543137 DOI: 10.1016/s1093-3263(02)00187-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A data set of 345 dihydrofolate reductase inhibitors was used to build QSAR models that correlate chemical structure and inhibition potency for three types of dihydrofolate reductase (DHFR): rat liver (rl), Pneumocystis carinii (pc), and Toxoplasma gondii (tg). Quantitative models were built using subsets of molecular structure descriptors being analyzed by computational neural networks. Neural network models were able to accurately predict log IC(50) values for the three types of DHFR to within +/-0.65 log units (data sets ranged approximately 5.5 log units) of the experimentally determined values. Classification models were also constructed using linear discriminant analysis to identify compounds as selective or nonselective inhibitors of bacterial DHFR (pcDHFR and tgDHFR) relative to mammalian DHFR (rlDHFR). A leave-N-out training procedure was used to add robustness to the models and to prove that consistent results could be obtained using different training and prediction set splits. The best linear discriminant analysis (LDA) models were able to correctly predict DHFR selectivity for approximately 70% of the external prediction set compounds. A set of new nitrogen and oxygen-specific descriptors were developed especially for this data set to better encode structural features, which are believed to directly influence DHFR inhibition and selectivity.
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Affiliation(s)
- Brian E Mattioni
- Department of Chemistry, The Pennsylvania State University, 152 Davey Laboratory, University Park, PA 16802, USA
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Gangjee A, Mavandadi F, Queener SF. Conformationally restricted tricyclic analogues of lipophilic pyrido[2,3- d]pyrimidine antifolates. J Heterocycl Chem 2001. [DOI: 10.1002/jhet.5570380132] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Abstract
The unique structure of the human eye as well as exposure of the eye directly to the environment renders it vulnerable to a number of uncommon infectious diseases caused by fungi and parasites. Host defenses directed against these microorganisms, once anatomical barriers are breached, are often insufficient to prevent loss of vision. Therefore, the timely identification and treatment of the involved microorganisms are paramount. The anatomy of the eye and its surrounding structures is presented with an emphasis upon the association of the anatomy with specific infection of fungi and parasites. For example, filamentous fungal infections of the eye are usually due to penetrating trauma by objects contaminated by vegetable matter of the cornea or globe or, by extension, of infection from adjacent paranasal sinuses. Fungal endophthalmitis and chorioretinitis, on the other hand, are usually the result of antecedent fungemia seeding the ocular tissue. Candida spp. are the most common cause of endogenous endophthalmitis, although initial infection with the dimorphic fungi may lead to infection and scarring of the chorioretina. Contact lens wear is associated with keratitis caused by yeasts, filamentous fungi, and Acanthamoebae spp. Most parasitic infections of the eye, however, arise following bloodborne carriage of the microorganism to the eye or adjacent structures.
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Klotz SA, Penn CC, Negvesky GJ, Butrus SI. Fungal and parasitic infections of the eye. Clin Microbiol Rev 2000; 13:662-85. [PMID: 11023963 PMCID: PMC88956 DOI: 10.1128/cmr.13.4.662] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The unique structure of the human eye as well as exposure of the eye directly to the environment renders it vulnerable to a number of uncommon infectious diseases caused by fungi and parasites. Host defenses directed against these microorganisms, once anatomical barriers are breached, are often insufficient to prevent loss of vision. Therefore, the timely identification and treatment of the involved microorganisms are paramount. The anatomy of the eye and its surrounding structures is presented with an emphasis upon the association of the anatomy with specific infection of fungi and parasites. For example, filamentous fungal infections of the eye are usually due to penetrating trauma by objects contaminated by vegetable matter of the cornea or globe or, by extension, of infection from adjacent paranasal sinuses. Fungal endophthalmitis and chorioretinitis, on the other hand, are usually the result of antecedent fungemia seeding the ocular tissue. Candida spp. are the most common cause of endogenous endophthalmitis, although initial infection with the dimorphic fungi may lead to infection and scarring of the chorioretina. Contact lens wear is associated with keratitis caused by yeasts, filamentous fungi, and Acanthamoebae spp. Most parasitic infections of the eye, however, arise following bloodborne carriage of the microorganism to the eye or adjacent structures.
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Affiliation(s)
- S A Klotz
- Section of Infectious Diseases, Veterans Affairs Medical Center, Kansas City, Missouri 64128, USA.
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Selected Infectious Diseases. Fam Med 1998. [DOI: 10.1007/978-1-4757-2947-4_44] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Fung HB, Kirschenbaum HL. Treatment regimens for patients with toxoplasmic encephalitis. Clin Ther 1996; 18:1037-56; discussion 1036. [PMID: 9001822 DOI: 10.1016/s0149-2918(96)80059-2] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Toxoplasma gondii is an obligate intracellular parasitic protozoan that infects a variety of warm-blooded animals, including humans. Infection is usually asymptomatic in immunocompetent individuals but may be devastating in immunocompromised individuals such as those with acquired immunodeficiency syndrome (AIDS). Clinical manifestations of infection in immunocompromised patients include the development of encephalitis. It has been estimated that approximately 30% of patients with AIDS who are latently infected will eventually develop toxoplasmic encephalitis. The most common regimen used to treat toxoplasmic encephalitis is a combination of pyrimethamine 50 to 100 mg/d and sulfadiazine 4 to 8 g/d, with or without folinic acid 10 mg/d. This regimen, however, commonly leads to adverse effects or relapses. Other pharmacologic approaches include the use of clindamycin rather than sulfadiazine, the macrolide antibiotics, atovaquone, 5-fluorouracil, trimethoprim/sulfamethoxazole, minocycline or doxycycline, trimetrexate with folinic acid, dapsone, rifabutin, pentamidine, and diclazuril. None of these alternative regimens has been proven to be more effective than the standard pharmacologic therapy. An evolving approach is the use of immunotherapy, such as interleukin-2, -6, and -12; interferon-gamma; and alpha-tumor necrosis factor. Restoring a competent immune system may be the only cure for toxoplasmosis and other opportunistic infections.
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Affiliation(s)
- H B Fung
- Arnold & Marie Schwartz College of Pharmacy and Health Sciences, Long Island University, Brooklyn, New York, USA
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