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1.
Bioimpacts ; 12(1): 3-7, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35087711

RESUMO

Introduction: Krabbe disease (KD) or globoid cell leukodystrophy (GLD) is one of the lysosomal disorders affecting central and peripheral nervous systems (CNS and PNS). It is caused by mutations on the galactocerebrosidase (GALC) gene. Affected individuals accumulate undegraded substrates and suffer from neuroinflammation. Methods: Hematopoietic stem cell transplantation (HSCT) has been partially successful in treating patients with KD when accomplished prior to the onset of symptoms. The success is credited to the ability of the hematopoietic stem cells in providing some GALC enzyme to the CNS and eradicating potential neuroinflammation. Combination of the HSCT with some other GALC-providing strategies has shown synergistic effects in the treatment of the mouse model of this disease. Results: Here, the possibility of eliminating HSCT in the treatment of human patients and replacing it with a single therapy that will provide sufficient GALC enzyme to the nervous systems is suggested. Such treatment, if started during the asymptomatic stage of the disease, not only may eradicate the enzyme deficiency, but may also keep any neuroinflammation at bay. Conclusion: Successful treatment of the KD may be possible by restoring consistent and sufficient GALC expression in CNS and PNS.

2.
Int J Neonatal Screen ; 7(3)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34449528

RESUMO

Krabbe disease is an autosomal recessive leukodystrophy caused by pathogenic variants in the galactocerebrosidase (GALC) gene. GALC activity is needed for the lysosomal hydrolysis of galactosylceramide, an important component of myelin. While most patients are infants, older patients are also diagnosed. Starting in 1970, a diagnosis could be made by measuring GALC activity in leukocytes and cultured cells. After the purification of GALC in 1993, the cDNA and genes were cloned. Over 260 disease-causing variants as well as activity lowering benign variants have been identified. While some pathogenic variants can be considered "severe," others can be considered "mild." The combination of alleles determines the type of Krabbe disease a person will have. To identify patients earlier, newborn screening (NBS) has been implemented in several states. Low GALC activity in this screening test may indicate a diagnosis of Krabbe disease. Second tier testing as well as neuro-diagnostic studies may be required to identify those individuals needing immediate treatment. Treatment of pre-symptomatic or mildly symptomatic patients at this time is limited to hematopoietic stem cell transplantation. Treatment studies using the mouse and dog models have shown that combining bone marrow transplantation with intra-venous gene therapy provides the best outcomes in terms of survival, behavior, and preservation of normal myelination in the central and peripheral nervous systems. With earlier diagnosis of patients through newborn screening and advances in treatment, it is hoped that more patients will have a much better quality of life.

3.
Bioimpacts ; 11(2): 135-146, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33842284

RESUMO

Introduction: Krabbe disease (KD) is an autosomal recessive disorder caused by mutations in the galactocerebrosidase (GALC) gene resulting in neuro-inflammation and defective myelination in the central and peripheral nervous systems. Most infantile patients present with clinical features before six months of age and die before two years of age. The only treatment available for pre-symptomatic or mildly affected individuals is hematopoietic stem cell transplantation (HSCT). In the animal models, combining bone marrow transplantation (BMT) with gene therapy has shown the best results in disease outcome. In this study, we examine the outcome of gene therapy alone. Methods: Twitcher (twi) mice used in the study, have a W339X mutation in the GALC gene. Genotype identification of the mice was performed shortly after birth or post-natal day 1 (PND1), using polymerase chain reaction on the toe clips followed by restriction enzyme digestion and electrophoresis. Eight or nine-day-old affected mice were used for gene therapy treatment alone or combined with BMT. While iv injection of 4 × 1013 gc/kg of body weight of viral vector was used originally, different viral titers were also used without BMT to evaluate their outcomes. Results: When the standard viral dose was increased four- and ten-fold (4X and 10X) without BMT, the lifespans were increased significantly. Without BMT the affected mice were fertile, had the same weight and appearance as wild type mice and had normal strength and gait. The brains showed no staining for CD68, a marker for activated microglia/macrophages, and less astrogliosis than untreated twi mice. Conclusion: Our results demonstrate that, it may be possible to treat human KD patients with high dose AAVrh10 without blood stem cell transplantation which would eliminate the side effects of HSCT.

4.
Cureus ; 13(3): e13709, 2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33833923

RESUMO

Purpose It is often difficult for the clinician to isolate the etiology of pain occurring either in the neck or shoulder because of the reason that neck pain can refer to the shoulder and vice versa. Concordance research has found that around one in 10 patients who were referred for cervical radiculopathy had comorbid shoulder pathology. The goal of this research is to analyze and correlate risk factors for persistent shoulder pain (non-dermatomal) following cervical spine surgery. Methods This was a single-center, retrospective study. The medical records of patients admitted for anterior cervical discectomy and fusion (ACDF) were reviewed from August 2018 to Feb 2021. Patients of both sexes and age more than 18 years who underwent ACDF (single/multiple levels) were included and the medical record was checked for whether they had persistent shoulder pain following ACDF. The proportion of patients undergoing shoulder surgery for associated rotator cuff tears and subacromial impingement were recorded. Results Seventy patients presenting with cervical prolapsed intervertebral disc (PID) were studied. A majority of our patients were females (n=48, 68.6%) and males (n=22, 31.4%) with an M:F ratio of 1:2 and the majority of patients were between the ages of 40 to 60 years (n=34, 48.6%). After surgical intervention (ACDF), 48 patients (68.6%) noted the cessation of shoulder symptoms (pain, weakness, and numbness) during their last visit. Rotator cuff tear (supraspinatus mainly) was the predominant finding in MRI in those who didn't improve after ACDF (n=18, 25.7%, p-value: 0.001). Twenty patients (28.6%) underwent acromioplasty and rotator cuff tendon repair and four patients responded well to subacromial injection. The C6-7 level was most commonly affected (n=48, 68.6%) followed by C5-6 level (n=19, 27.1%). No significant association was found between cervical levels with shoulder pathologies (p-0.171), though a significant association between a visual analog scale (VAS) score >7 after surgery with shoulder pathologies (p-0.001) was found. The C6-7 level was commonly affected in females (p=0.038) but no significant association between gender and shoulder pathologies was found (p=0.332). Conclusion Dual pathologies in patients with cervical PID are very common. It needs careful attention by doing thorough clinical examination and correlating patient symptoms with radiological investigations. A patient who presents with persistent shoulder pain after cervical spine surgery had a higher chance of having concurrent shoulder pathology, and they should be properly investigated and managed to alleviate the suffering of the patient.

5.
Expert Opin Biol Ther ; 21(9): 1181-1197, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33653197

RESUMO

INTRODUCTION: Mucopolysaccharidoses (MPS), as a group of inherited lysosomal storage disorders (LSDs), are clinically heterogeneous and characterized by multi-systemic manifestations, such as skeletal abnormalities and neurological dysfunctions. The currently used enzyme replacement therapy (ERT) might be associated with several limitations including the low biodistribution of the enzymes into the main targets, immunological responses against foreign enzymes, and the high cost of the treatment procedure. Therefore, a suitable combination approach can be considered for the successful treatment of each type of MPS. AREAS COVERED: In this review, we provide comprehensive insights into the ERT-based combination therapies of MPS by reviewing the published literature on PubMed and Scopus. We also discuss the recent advancements in the treatment of MPS and bring up the hopes and hurdles in the futuristic treatment strategies. EXPERT OPINION: Given the complex pathophysiology of MPS and its involvement in different tissues, the ERT of MPS in combination with stem cell therapy or gene therapy is deemed to provide a personalized precision treatment modality with the highest therapeutic responses and minimal side effects. By the same token, new combinational approaches need to be evaluated by using drugs that target alternative and secondary pathological pathways.


Assuntos
Doenças por Armazenamento dos Lisossomos , Mucopolissacaridoses , Terapia de Reposição de Enzimas , Terapia Genética , Humanos , Mucopolissacaridoses/tratamento farmacológico , Distribuição Tecidual
6.
Cureus ; 13(1): e12870, 2021 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-33633899

RESUMO

Purpose The purpose of this study is to compare the effect of pregabalin in reducing the neuropathic pain in postoperative patients who have undergone single-level microdiscectomy for prolapsed intervertebral lumbar disc. Methods A randomized control clinical trial was conducted from June 2018 to April 2020 in three campuses Dr. Ziauddin University Hospital, Karachi, by two spinal surgeons. This study included 84 patients who underwent either emergency or elective microdiscectomy surgery. The patients randomized into two equal groups of 42, (group-A: pregabalin) and (group-B: placebo). Both groups also received routine analgesia along with the pregabalin and placebo capsules. In the intervention group, pregabalin was administered preoperative and postoperative defined times. The pain scores were recorded by visual analog scale (VAS) and Roland-Morris score system on the preoperative day and compared to the scores on follow-up on postoperative day seven. Results The pain scores were significantly better in group-A compared to group-B with similar baseline variables. The mean VAS scores of pains in group-A on postoperative day seven on follow-up were compared to VAS pain scores in group-B showing better pain control. The Roland-Morris scores were also significantly better for group-A. Conclusions The use of pregabalin in addition to the routine analgesia has better control of postoperative neuropathic pain in patients with single-level microdiscectomy compared to the patients who are receiving only routine analgesia. Other factors like cost, dose, side effects, and frequency should also be considered.

7.
Cureus ; 12(10): e11277, 2020 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-33274152

RESUMO

BACKGROUND:  Tibia plateau fractures are most commonly managed with open reduction and internal fixation (ORIF) technique, external fixation via minimally invasive technique are an excellent alternative. The aim of this study was to assess the results of tibia plateau fractures by using the Ilizarov external fixator. The analysis was done both clinically and radiologically. METHODOLOGY:  Some 72 patients with isolated tibia plateau fractures were brought to ED and clinics and assessed. The fractures were classified according to Schatzker Tibia Plateau Fracture classification, only Schatzker type III to VI were included using conventional X-rays. All patients for their tibia plateau fractures underwent surgical correction using Ilizarov technique with full weight bearing and knee range of motion allowed the next day. Patient follow-up up to one year was done. KOOS and self-appraisal were used to evaluate the knee pain and function. RESULTS:  All the fractures healed with 67 patients achieving a range of motion better than 0-100º. KOOS score shows that patients who had worse fracture patterns (Schatzker-V and VI) have worse global scores (p=0.002); still when managed with an Ilizarov it has been seen that these patients are able to maintain a moderately pain free knee (p=0.013) other aspects of the KOOS. Patients with higher BMI showed to have worsening fracture patterns with 20 out of the 30 overweight patients suffering Schatzker-V (66.67%). We experienced an extremely low rate of pin tract infections with only two debridements required. CONCLUSION:  Ilizarov external fixation method is a valuable alternative treatment with excellent clinical outcomes and early mobilization.

8.
Bioimpacts ; 10(4): 207-208, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32983935

RESUMO

The toddling BioImpacts has now grown into a young adult with strong opinions and perspectives, to a high-quality journal, and it has not been raised but by a family of professional editors, reviewers, authors, and even readers who had fantasized about a bright future and that fantasies are now coming true one-by-one.

9.
Bioimpacts ; 10(2): 105-115, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32363154

RESUMO

Introduction: Krabbe disease (KD) is an autosomal recessive lysosomal disorder caused by mutations in the galactocerebrosidase (GALC) gene. This results in defective myelination in the peripheral and central nervous systems due to low GALC activity. Treatment at this time is limited to hematopoietic stem cell transplantation (HSCT) in pre-symptomatic individuals. While this treatment extends the lives of treated individuals, most have difficulty walking by the end of the first decade due to peripheral neuropathy. Studies in the murine model of KD, twitcher (twi) combining bone marrow transplantation (BMT) with AAVrh10-mGALC showed a great extension of life from 40 days to about 400 days, with some living a full life time. Methods: In order to find the optimum conditions for dosing and timing of this combined treatment, twi mice were injected with five doses of AAVrh10-mGALC at different times after BMT. Survival, as well as GALC expression were monitored along with studies of sciatic nerve myelination and possible liver pathology. Results: Dosing had a pronounced effect on survival and measured GALC activity. There was window of time after BMT to inject the viral vector and see similar results, however delaying both the BMT and the viral injection shortened the lifespans of the treated mice. Lowering the viral dose too much decreased the correction of the sciatic nerve myelination. There was no evidence for hepatic neoplasia. Conclusion: These studies provide the conditions optimum for successfully treating the murine model of KD. There is some flexibility in dosing and timing to obtain a satisfactory outcome. These studies are critical to the planning of a human trial combining the "standard of care", HSCT, with a single iv injection of AAVrh10-GALC.

10.
Drug Discov Today ; 25(6): 1034-1042, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32205198

RESUMO

Computational epitope-based vaccine design is the cornerstone of vaccine development. Owing to the selection of proper compositions [antigens (Ags), epitopes, peptide linkers, and intramolecular adjuvants], epitope-based vaccines are considered a cost- and time-effective approach resulting in the development of vaccines with maximal therapeutic efficacy and minimal adverse reactions. In this review, we provide insights into in silico epitope-based vaccine design and highlight vaccinology procedures used for the development of the next-generation vaccines with high effectiveness.


Assuntos
Epitopos de Linfócito T/genética , Vacinas/genética , Animais , Biologia Computacional/métodos , Humanos , Vacinologia/métodos
11.
J Drug Target ; 28(7-8): 700-713, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32116051

RESUMO

Despite many endeavours for the development of new anticancer drugs, effective therapy of solid tumours remains a challenging issue. The current cancer chemotherapies may associate with two important limitations, including the lack/trivial specificity of treatment modalities towards diseased cells/tissues resulting in undesired side effects, and the emergence of drug-resistance mechanisms by tumour cells causing the failure of the treatment. Much attention, therefore, has currently been paid to develop smart and highly specific anticancer agents with maximal therapeutic impacts and minimal side effects. Among various strategies used to target cancer cells, bacteria-based cancer therapies (BCTs) have been validated as potential gene/drug delivery carriers, which can also be engineered to be used in diagnosis processes. They can be devised to selectively target the tumour microenvironment (TME), within which they may preferentially proliferate in the necrotic and anaerobic parts - often inaccessible to other therapeutics. BCTs are capable to sense and respond to the environmental signals, upon which they are considered as smart microrobots applicable in the controlled delivery of therapeutic agents to the TME. In this review, we aimed to provide comprehensive insights into the potentials of the bioengineered bacteria as smart and targeted bio-carriers and discuss their applications in cancer therapy.


Assuntos
Antineoplásicos/uso terapêutico , Bactérias , Bioengenharia/métodos , Sistemas de Liberação de Medicamentos , Neoplasias/terapia , Animais , Antineoplásicos/administração & dosagem , Humanos
12.
Acta Chim Slov ; 67(4): 1124-1138, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33533461

RESUMO

Adsorption of Alizarin Red S (ARS) on graphene oxide/poly(amidoamine) (GO/PAMAM) was studied at different ARS initial concentrations, temperatures, pHs, shaking rates and contact times. Adsorption sites of GO/PAMAM were phenolic -OHgroup of GO and amine groups (-NH2, -NH3+ and -NHR2+) of PAMAM dendrimer moieties of GO/PAMAM. At pH = 2 and 318 K, maximum adsorption capacity of the adsorbent was 1275.2 mg g-1 which is one of the highest capacity in the literature. Thus, GO/PAMAM in this work acted as a superadsorbent for ARS. At the incipient of adsorption, molecules were adsorbed on sites that was reaction-controlled step, (Ea = 114.5 kJ mol-1). Adsorption of on the remaining sites was diffusion-controlled. In alkaline media, two other types of ARS molecules were identified during that were adsorbed on and sites. Further increasing the pH of the solution, decreased the number these two sites and yielded a reduced adsorption capacity . Methylene blue (MB), thionine (Th), pyronin Y (PY), acridine orange (AO), methyl blue (MEB) and janus green (JG) dyes were selectively separated from their mixtures with ARS molecules using GO/PAMAM at pH of 2. The used adsorbent was recycled efficiently by using ethylenediamine very fast.

13.
Neuroscience ; 424: 45-57, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31682825

RESUMO

The number of patients suffering from dementia due to Alzheimer's disease (AD) is constantly rising worldwide. This has accordingly resulted in huge burdens on the health systems and involved families. Lack of profound understanding of neural networking in normal brain and their interruption in AD makes the treatment of this neurodegenerative multifaceted disease a challenging issue. In recent years, mathematical and computational methods have paved the way towards a better understanding of the brain functional connectivity. Thus, much attention has been paid to this matter from both basic science researchers and clinicians with an interdisciplinary approach to determine what is not functioning properly in AD patients and how this malfunctioning can be addressed. In this review, a number of AD-related articles and well-studied pathophysiologic topics (e.g., amyloid-beta, neurofibrillary tangles, Ca2+ dysregulation, and synaptic plasticity alterations) has been literally surveyed from a computational and systems biology point of view. The neural networks were discussed from biological and mathematical point of views and their alterations in recent findings were further highlighted. Application of the graph theoretical analysis in the brain imaging was reviewed, depicting the relations between brain structure and function, without diving into mathematical details. Moreover, differential rate equations were briefly articulated, emphasizing the potential use of these equations in simplifying complex processes in relevance to pathologies of AD. Comprehensive insights were given into the AD progression from neural networks perspective, which may lead us towards potential strategies for early diagnosis and effective treatment of AD.


Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Encéfalo/metabolismo , Modelos Teóricos , Rede Nervosa/metabolismo , Proteínas tau/metabolismo , Doença de Alzheimer/patologia , Animais , Encéfalo/patologia , Humanos , Rede Nervosa/patologia
14.
Expert Opin Drug Deliv ; 16(6): 583-605, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31107110

RESUMO

INTRODUCTION: Transportation of the nutrients and other substances from the blood to the brain is selectively controlled by the brain capillary endothelial cells that form a restrictive barrier, so-called blood-brain barrier (BBB). Currently, there is no unimpeachable approach to overcome the BBB obstructiveness because the existing options are either invasive or ineffective. AREAS COVERED: This review delineates the biological impacts of BBB on brain drug delivery and targeting. The nanoscaled multifunctional shuttles armed with the targeting entities (e.g., antibodies and peptides) are discussed. Important insights are remarked into the combinatorial screening methodologies used for the identification of de novo peptides capable of crossing BBB and targeting the brain. EXPERT OPINION: Depending on the physicochemical properties of small molecules and macromolecules, they may cross the BBB and get into the brain either through passive diffusion or active/facilitated transportation and transcytosis in a very selectively controlled manner. Phage-derived shuttle peptides can specifically be selected against BBB endocytic machinery and used in engineering novel peptide-drug conjugates (PDCs). Nanoscaled multitargeting delivery systems encompassing PDCs can overcome the BBB obstructiveness and deliver drugs specifically to diseased cells in the brain with trivial side effects.


Assuntos
Barreira Hematoencefálica/metabolismo , Neoplasias Encefálicas/tratamento farmacológico , Sistemas de Liberação de Medicamentos , Animais , Encéfalo/metabolismo , Células Endoteliais/metabolismo , Humanos , Peptídeos/metabolismo , Transcitose
15.
Cell Mol Life Sci ; 76(17): 3363-3381, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31101939

RESUMO

Mucopolysaccharidoses (MPSs), which are inherited lysosomal storage disorders caused by the accumulation of undegraded glycosaminoglycans, can affect the central nervous system (CNS) and elicit cognitive and behavioral issues. Currently used enzyme replacement therapy methodologies often fail to adequately treat the manifestations of the disease in the CNS and other organs such as bone, cartilage, cornea, and heart. Targeted enzyme delivery systems (EDSs) can efficiently cross biological barriers such as blood-brain barrier and provide maximal therapeutic effects with minimal side effects, and hence, offer great clinical benefits over the currently used conventional enzyme replacement therapies. In this review, we provide comprehensive insights into MPSs and explore the clinical impacts of multimodal targeted EDSs.


Assuntos
Terapia de Reposição de Enzimas , Doenças por Armazenamento dos Lisossomos/terapia , Mucopolissacaridoses/terapia , Barreira Hematoencefálica/metabolismo , Moléculas de Adesão Celular/metabolismo , Portadores de Fármacos/química , Glucosilceramidase/genética , Glucosilceramidase/metabolismo , Glucosilceramidase/uso terapêutico , Humanos , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/uso terapêutico
17.
Bioimpacts ; 8(3): 153-157, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30211074

RESUMO

Despite many beneficial outcomes of the conventional enzyme replacement therapy (ERT), several limitations such as the high-cost of the treatment and various inadvertent side effects including the occurrence of an immunological response against the infused enzyme and development of resistance to enzymes persist. These issues may limit the desired therapeutic outcomes of a majority of the lysosomal storage diseases (LSDs). Furthermore, the biodistribution of the recombinant enzymes into the target cells within the central nervous system (CNS), bone, cartilage, cornea, and heart still remain unresolved. All these shortcomings necessitate the development of more effective diagnosis and treatment modalities against LSDs. Taken all, maximizing the therapeutic response with minimal undesired side effects might be attainable by the development of targeted enzyme delivery systems (EDSs) as a promising alternative to the LSDs treatments, including different types of mucopolysaccharidoses ( MPSs ) as well as Fabry, Krabbe, Gaucher and Pompe diseases.

18.
Indian J Psychol Med ; 40(2): 191-192, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29962579

RESUMO

The U.S. Food and Drug Administration (FDA) has approved a supplemental new drug application Lurasidone (Latuda, Sunovion Pharmaceuticals), an atypical antipsychotic, for the treatment of schizophrenia in adolescents 13-17 years of age. Lurasidone was previously indicated in the U.S. for the treatment of adults with schizophrenia and major depressive episodes with bipolar I disorder as monotherapy. We present a case of a 29-year-old male patient who was hospitalized with thrombocytopenia (WHO grade-3 toxicity) (unlabeled) along with extrapyramidal disorder, gastritis, and hyperprolactinemia within 2-3 months of initiation of tablet lurasidone 80 mg/day (Lurasid, Intas Pharmaceuticals) in bipolar depression. Dechallenge was found to be positive in three reactions except hyperprolactinemia (outcome unknown) during hospital stay. The terms anemia and leukopenia are well labeled/listed with the drug literatures of lurasidone. Thus, this case presents a strong probability of lurasidone to cause myelosuppression/bone marrow depression.

19.
Bioimpacts ; 8(1): 31-38, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29713600

RESUMO

Introduction: Measurement of thrombolytic activity is crucial for research and development of novel thrombolytics. It is a key factor in the assessment of the effectiveness of conventionally used thrombolytic therapies in the clinic. Previous methods used for the assessment of thrombolytic activity are often associated with some drawbacks such as being costly, time-consuming, complex with low accuracy. Here, we introduce a simple, economic, relatively accurate and fast method of spectrophotometric analysis of thrombolytic activity (SATA) assay, standardized by tissue plasminogen activator (tPA), which can quantitatively measure in vitro thrombolytic activity. Methods: Blood clots were formed, uniformly, by mixing citrated whole blood with partial thromboplastin time (PTT) reagent, together with calcium chloride. Then, designated concentrations of tPA were added to the samples, and the released red blood cells from each clot were quantified using spectrophotometry (λmax=405nm) as an indicator of thrombolytic activity. The accuracy of the method was tested by assessment of dose-responsibility against R2 value obtained by linear equation and measurement of the limit of detection (LOD) and limit of quantification (LOQ). The SATA assay was validated in comparison with some currently used techniques. Results: A linear relationship was obtained between different concentrations of tPA versus the spectrophotometric absorbance of the related dilutions of lysed clots, at λmax=405nm. Calculated R2 values were greater than 0.9; with LOD of 0.90 µg/mL of tPA (436.50IU) and LOQ of 2.99 µg/mL of tPA (1450.15IU). Conclusion: Conclusively, the SATA assay is a very simple quantitative method with repeatable and reproducible results for estimating the potency of an unknown thrombolytic agent, and calculating the activity as delicate as 1 µg/mL of tPA (485 IU/mL of thrombolytic dose).

20.
Bioconjug Chem ; 29(5): 1729-1735, 2018 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-29660287

RESUMO

Trimethoprim is one of the most widely used antibiotics in the world. However, its efficacy is frequently limited by its poor water solubility and dose limiting toxicity. Prodrug strategies based on conjugation of oligosaccharides to trimethoprim have great potential for increasing the solubility of trimethoprim and lowering its toxicity, but they have been challenging to develop due to the sensitivity of trimethoprim to chemical modifications, and the rapid degradation of oligosaccharides in serum. In this report, we present a trimethoprim conjugate of maltodextrin termed TM-TMP, which increased the water solubility of trimethoprim by over 100 times, was stable to serum enzymes, and was active against urinary tract infections in mice. TM-TMP is composed of thiomaltose conjugated to trimethoprim, via a self-immolative disulfide linkage, and releases 4'-OH-trimethoprim (TMP-OH) after disulfide cleavage, which is a known metabolic product of trimethoprim and is as potent as trimethoprim. TM-TMP also contains a new maltodextrin targeting ligand composed of thiomaltose, which is stable to hydrolysis by serum amylases and therefore has the metabolic stability needed for in vivo use. TM-TMP has the potential to significantly improve the treatment of a wide number of infections given its high water solubility and the widespread use of trimethoprim.


Assuntos
Antibacterianos/química , Antibacterianos/uso terapêutico , Polissacarídeos/química , Polissacarídeos/uso terapêutico , Trimetoprima/análogos & derivados , Trimetoprima/uso terapêutico , Infecções Urinárias/tratamento farmacológico , Animais , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Infecções por Escherichia coli/tratamento farmacológico , Feminino , Maltose/análogos & derivados , Maltose/farmacologia , Maltose/uso terapêutico , Camundongos , Polissacarídeos/farmacologia , Trimetoprima/farmacologia
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