Spiramyin-loaded PLGA implants for the treatment of ocular toxoplasmosis: development, characterization, biocompatibility, and anti-toxoplasma activity.

Ocular toxoplasmosis is the major cause of infectious posterior uveitis worldwide, inducing visual field defect and/or blindness. Despite the severity of this disease, an effective treatment is still lacking. In this study, spiramycin-loaded PLGA implants were developed aiming at the treatment of ocular toxoplasmosis. Implants were manufactured by a hot-molding technique, characterized by Fourier Transform Infrared Spectroscopy, X-Ray Diffraction, Differential Scanning Calorimetry, Scanning Electron Microscopy; evaluated in terms of ocular biocompatibility by immunofluorescence, flow cytometry, cell migration, Hen's egg test-chorioallantoic membrane (HET-CAM) irritation test; and investigated in terms of in vitro efficacy against Toxoplasma gondii . Characterization techniques indicated that spiramycin was dispersed into the polymeric chains and both substances preserved their physical structures in implants. The HET-CAM test indicated that implants did not induce hemorrhage or coagulation, being non-irritant to the CAM. ARPE-19 cells showed viability by MTT assay, and normality in cell cycle kinetics and morphology, without stimulating cell death by apoptosis. Finally, they were highly effective against intracellular parasites without inducing human retinal pigment epithelial cell death. In conclusion, spiramycin-loaded PLGA implants represent a promising therapeutic alternative for the local treatment of ocular toxoplasmosis.

Fractional kinetics on thermal analysis: application to lumefantrine thermal decomposition.

The fractional derivative concept to treat non-isothermal solid state thermal decomposition was employed in this work. Simulated data were compared with the exact solutions for the method validation. Calculated fractional kinetics data for four heating rates were initially considered and the Kissinger-Akahira-Sunose (KAS) method demonstrate that, although the activation energy is not retrieved, it can be useful to determine a single or multistep process. Experimental thermal decomposition data of lumefantrine heated at 5, 10 ,15, and 20 oC min- 1 were fitted for a single-step process. The kinetic parameters were retrieved for integer and fractional kinetics, considering some ideal and general models. Application of the KAS method to these data demonstrated an activation energy dependent on the conversion rate, indicating a multistep process. Five data subintervals were fitted separately using the general model with variable derivative order. It was found a process that occours with integer order derivative until α = 0.3 and fractional order for α > 0.3 with combination of simultaneous reactions, since the parameters do not correspond to any ideal model. The determined activation energies showed the same increasing behavior observed in the KAS approach. The results for multistep process presented an error 102 times smaller if compared with the best result, considering a single-step process. Therefore, the fractional kinetic model presents a powerful extension to the usual thermal data analysis.

Reduction of doxorubicin-induced genotoxicity by Handroanthus impetiginosus in mouse bone marrow revealed by micronucleus assay / Redução da genotoxicidade induzida pela doxorrubicina por Handroanthus impetiginosus na medula óssea de camundongos revelada pelo ensaio do micronúcleo

Abstract Handroanthus impetiginosus has long been used in traditional medicine and various studies have determined the presence of bioactive chemical compounds and potential phytotherapeutics. In this study, the genotoxicity of the lyophilized tincture of H. impetiginosus bark (THI) was evaluated in mouse bone marrow using micronucleus assays. The interaction between THI and genotoxic effects induced by the chemotherapeutic agent, doxorubicin (DXR), was also analyzed. Experimental groups were evaluated 24 to 48 h after treatment with N-nitroso-N-ethylurea (NEU; 50 mg/kg), DXR (5 mg/kg), sodium chloride (NaCl; 150 mM), and THI (0.5-2 g/kg). Antigenotoxic assays were carried out using THI (0.5 g/kg) in combination with NEU or DXR. Analysis of the micronucleated polychromatic erythrocytes (MNPCEs) indicated no significant differences between treatment doses of THI (0.5-2 g/kg) and NaCl. Polychromatic erythrocyte (PCE) to normochromatic erythrocyte (NCE) ratios did not indicate any statistical differences between DXR and THI or NaCl, but there were differences between THI and NaCl. A significant reduction in MNPCEs and PCE/NCE ratios was observed when THI was administered in combination with DXR. This study suggested the absence of THI genotoxicity that was dose-, time-, and gender-independent and the presence of moderate systemic toxicity that was dose-independent, but time- and gender-dependent. The combination of THI and DXR also suggested antigenotoxic effects, indicating that THI reduced genotoxic effects induced by chemotherapeutic agents.

Resumo Handroanthus impetiginosus tem sido usada durante um longo período pela medicina tradicional e vários estudos têm demonstrados a presença de compostos químicos e potencial fitoterapêutico. Esta pesquisa avaliou a genotoxicidade da tintura da casca liofilizada de H. impetiginosus (THI) usando o ensaio do micronúcleo em medula óssea de camundongos. A interação entre THI e os efeitos genotóxicos induzidos pelo quimioterápico doxorrubicina (DXR) também foram analisados. Grupos experimentais foram analisados a 24-48 h após o tratamento com N-Nitroso-N-etiluréia (NEU; 50 mg/kg), DXR (5 mg/kg), NaCl (150 mM) e THI (0,5-2 g/kg). O ensaio antigenotóxico foi conduzido utilizando THI (0,5 g/kg) em combinação com NEU ou DXR. A análise de eritrócitos policromáticos micronucleados (EPCMNs) não mostrou diferenças significativas entre as doses de tratamento (0,5-2 g/kg) e NaCl. As proporções de eritrócitos policromáticos (EPC)/eritrócitos normocromáticos (ENC) não revelaram diferenças estatísticas entre DXR e THI ou NaCl, porém houve diferenças entre THI e NaCl. Uma redução significativa em EPCMNs e na razão EPC/ENC foi observada quando THI foi administrado em combinação com DXR. Essa pesquisa sugere ausência de genotoxicidade de THI, dose-, tempo- e sexo-independente, e moderada toxicidade sistêmica dose-independente, mas tempo- e sexo-dependente. A associação do THI e DXR também sugere efeitos antigenotóxicos. Por conseguinte, THI pode reduzir os efeitos genotóxicos induzidos pelo quimioterapêutico.

Reduction of doxorubicin-induced genotoxicity by Handroanthus impetiginosus in mouse bone marrow revealed by micronucleus assay.

Handroanthus impetiginosus has long been used in traditional medicine and various studies have determined the presence of bioactive chemical compounds and potential phytotherapeutics. In this study, the genotoxicity of the lyophilized tincture of H. impetiginosus bark (THI) was evaluated in mouse bone marrow using micronucleus assays. The interaction between THI and genotoxic effects induced by the chemotherapeutic agent, doxorubicin (DXR), was also analyzed. Experimental groups were evaluated 24 to 48 h after treatment with N-nitroso-N-ethylurea (NEU; 50 mg/kg), DXR (5 mg/kg), sodium chloride (NaCl; 150 mM), and THI (0.5-2 g/kg). Antigenotoxic assays were carried out using THI (0.5 g/kg) in combination with NEU or DXR. Analysis of the micronucleated polychromatic erythrocytes (MNPCEs) indicated no significant differences between treatment doses of THI (0.5-2 g/kg) and NaCl. Polychromatic erythrocyte (PCE) to normochromatic erythrocyte (NCE) ratios did not indicate any statistical differences between DXR and THI or NaCl, but there were differences between THI and NaCl. A significant reduction in MNPCEs and PCE/NCE ratios was observed when THI was administered in combination with DXR. This study suggested the absence of THI genotoxicity that was dose-, time-, and gender-independent and the presence of moderate systemic toxicity that was dose-independent, but time- and gender-dependent. The combination of THI and DXR also suggested antigenotoxic effects, indicating that THI reduced genotoxic effects induced by chemotherapeutic agents.

Cryoprecipitate AHF vs. fibrinogen concentrates for fibrinogen replacement in acquired bleeding patients - an economic evaluation.

BACKGROUND: Fibrinogen repletion in patients with acquired bleeding disorders can be accomplished by transfusing cryoprecipitate AHF (cryo) or fibrinogen concentrate (FC); thus, we undertook an economic evaluation from the transfusion service perspective regarding the use of cryo vs. FC in patients with acquired bleeding. METHODS: We created a model comparing the cost of cryo vs. FC from the transfusion service perspective. A patient with acquired bleeding requiring fibrinogen replacement could receive either 15-20 cryo units or 3-4 g FC, consistent with the guidelines from the European Task Force for Advanced Bleeding Care in Trauma. All model parameters were estimated from institutional experiences and the medical literature. Additionally, a survey of US Transfusion Medicine fellowship directors was conducted. RESULTS: After adjusting for 28% wastage and technologist salary, cryo cost is $414/5-unit pool. Depending on the dose, FC is more expensive by $976-$1303. To be competitive with cryo, FC cost must decrease by 44% or be shown to save 0·25-0·66 ICU days. Of the 30 survey replies, 96·7% of US centres do not use FC for acquired bleeding with the top three reasons being cost (30%), off-label usage (27%) and insufficient evidence for usage (20%). Only 47% are willing to pay more for FC, with $437/g as the median amount. CONCLUSION: Fibrinogen concentrate is more expensive than cryo, even after adjusting for cryo wastage. To be economically competitive with cryo, FC must cost $414/g, or save on ICU length of stay, consistent with the survey's results.

Anti-Blood Group Antibodies in Intravenous Immunoglobulin May Complicate Interpretation of Antibody Titers in ABO-Incompatible Transplantation.

Patients receiving ABO-incompatible (ABOi) kidney transplants are treated before and after transplant with combination therapy, such as intravenous immunoglobulin (IVIG) and therapeutic plasma exchange, to prevent allograft rejection by reducing anti-A and anti-B titers. Although generally considered safe, it is well known that commercial IVIG products contain detectable anti-A and anti-B, which can be associated with hemolysis. Different preparative manufacturing techniques during the production of IVIG affect ABO antibody levels in IVIG preparations; therefore, some manufacturers now use new methods to reduce anti-A/B levels at the preproduction stage. The variations in implementing these strategies creates the potential for significant variation in antibody titers between products and, in some cases, even between lots of the same IVIG product. We report a case of persistently elevated anti-A titers in an ABOi kidney transplant recipient associated with elevated ABO antibody titers present in the preparation of IVIG used at our facility.

High-sensitivity dispersive Mach-Zehnder interferometer based on a dissimilar-doping dual-core fiber for sensing applications.

A dual-core fiber in which one of the cores is doped with germanium and the other with phosphorus is used as an in-line Mach-Zehnder dispersive interferometer. By ensuring an equal length but with different dispersion dependencies in the interferometer arms (the two cores), high-sensitivity strain and temperature sensing are achieved. Opposite sensitivities for high and low wavelength peaks were also demonstrated when strain and temperature was applied. To our knowledge this is the first time that such behavior is demonstrated using this type of in-line interferometer based on a dual-core fiber. A sensitivity of (0.102±0.002) nm/µÎµ, between 0 and 800 µÎµ and (-4.2±0.2) nm/°C between 47°C and 62°C is demonstrated.

Membrane attack complex generation increases as a function of time in stored blood.

OBJECTIVE: To determine if the complement system, a potent mediator of inflammation, contributes to haemolysis during red blood cell (RBC) storage. BACKGROUND: RBCs in storage undergo structural and biochemical changes that may result in adverse patient outcomes post-transfusion. Complement activation on leukodepletion and during storage may contribute to the RBC storage lesion. METHODS/MATERIALS: We performed a cross-sectional analysis of aliquots of leukoreduced RBC units, stored for 1-6 weeks, for the levels of C3a, C5a, Bb, iC3b, C4d and C5b-9 [membrane attack complex (MAC)] by enzyme-linked immunosorbent assay (ELISA). RESULTS: We observed that only MAC levels significantly increased in RBC units as a function of storage time. We also observed that the level of C5b-9 bound to RBCs increased as a function of storage time. CONCLUSION: MAC levels increased over time, suggesting that MAC is the primary complement-mediated contributor to changes in stored RBCs. Inhibition of the terminal complement pathway may stabilise RBC functionality and extend shelf life.

An inquiry into the relationship between ABO blood group and thrombotic thrombocytopenic purpura.

BACKGROUND AND OBJECTIVES: ABO blood group accounts for up to 40% of the variability in plasma von Willebrand factor (VWF) levels, which vary in the rank order AB > B > A > O > Bombay. This may be due in part to the influence of ABO-associated oligosaccharides on the proteolysis of VWF by the metalloprotease ADAMTS13, which is markedly deficient in thrombotic thrombocytopenic purpura (TTP). Using ABO blood group as a surrogate for baseline VWF levels as well as susceptibility to proteolysis by ADAMST13, we set out to determine whether ABO blood group influences the clinical course of TTP. METHODS: We conducted a retrospective analysis of the clinical course of 76 patients with primary, sporadic TTP treated at two institutions over the past 10 years. RESULTS: We found no significant differences between group O and non-O patients with respect to presenting platelet count and lactate dehydrogenase concentration, maximum serum creatinine concentration, and total number of therapeutic plasma exchanges per episode. CONCLUSIONS: Substrate-related contributors to the highly variable phenotype and clinical course of TTP warrant further investigation.

Patients with thrombotic thrombocytopenic purpura commonly develop metabolic alkalosis during therapeutic plasma exchange.

Thrombotic thrombocytopenic purpura (TTP) and myasthenia gravis (MG) are category I indications for therapeutic plasma exchange (TPE). This study was based on the hypothesis that the development of metabolic alkalosis during TPE is more common in TTP than in MG, based on our previous observations. In order to test it, we compared the levels of bicarbonate and potassium in both groups of patients undergoing plasmapheresis. Fifteen patients with TTP (190 procedures) and ten MG patients seen concurrently were studied. While baseline bicarbonate levels were similar among all patients, the post-procedure bicarbonate levels in TTP patients were mostly elevated with a mean +/- SD of 29.4 +/- 3.5 mEq/L, as opposed to decreased or unchanged in MG patients 26.3 +/- 3.1 mEq/L (mean +/- SD) (P = 1.4 x 10(-8)). Furthermore, alkalosis in the TTP group persisted throughout subsequent daily treatments. There was also a significant decrease between pre- and post-TPE potassium levels in TTP patients (P = 3 x 10(-21)) by paired Student's t test. Additionally, samples with levels <3.3 mEq/L were alkalotic 75% of the time. In the MG group, however, potassium was normal in 85% and 83% of the pre- and post-TPE samples, respectively. Consequently, the hypokalemia was significantly more marked in the TTP group (P = 0.0008). These data confirm that plasmapheresis commonly induces metabolic alkalosis in TTP patients, probably due to high citrate in fresh frozen plasma, the frequency of treatments, and perhaps decreased renal clearance due to disease involvement of the kidneys.

When to suspect hypercoagulability and how to investigate it.

The authors summarize the current knowledge in the area of novel risk factors for venous thrombosis, both genetic and acquired causes of hypercoagulability. Because the list of genetic defects that predispose carriers to develop thrombosis has increased significantly in recent years, along with the available assays to test for them, hypercoagulability has been a subject of much discussion. This review highlights the issues on hypercoagulability that pathologists who are not specialists in coagulation should be familiar with, in order to provide consultation to other physicians. An educated approach to the diagnosis of this newly described group of disorders will ensure more cost-effective and efficient care to patients at risk.

Histologic examination of bone marrow core biopsy specimens has limited value in the diagnosis of mycobacterial and fungal infections in patients with the acquired immunodeficiency syndrome.

Bone marrow cultures and biopsy specimens are commonly obtained to rule out disseminated infections, especially in persons with the acquired immunodeficiency syndrome (AIDS) and cytopenias. Using culture as the gold standard, we reviewed 130 consecutive bone marrow cores obtained from 114 AIDS patients along with results of concurrent blood and/or bone marrow aspirate cultures to determine the usefulness of histologic examination for diagnosis of mycobacterial and fungal infections. We also compared the ability of Ziehl-Neelsen, auramine-rhodamine (AR), polyclonal antibody to Mycobacterium bovis (Ab), and Gomori's methenamine silver staining to detect infections. Twenty-seven patients had mycobacterial infection (25 Mycobacterium avium-intracellulare complex cases and two Mycobacterium tuberculosis cases) detected by blood and/or bone marrow cultures. The maximum sensitivity of histology was 50% when the auramine-rhodamine stain and the polyclonal antibody to M bovis were used in combination. The single best stain was auramine-rhodamine, with a sensitivity of 44%, followed by the polyclonal antibody to M bovis (35%). Granulomas were observed in nine cases of mycobacterial infection and did not correlate with the presence of stainable organisms. Of seven patients with positive fungal cultures of bone marrow, four had granulomas and a positive Gomori's methenamine silver stain, one had only a positive stain, and two had neither granulomas nor a diagnostic stain. Overall, granulomas were not sensitive for the detection of infections when culture-proven mycobacterial and fungal cases were evaluated together. We conclude that bone marrow examination has a limited value in the routine evaluation of common opportunistic infections in AIDS patients and recommend that less-invasive tests, such as blood cultures, be obtained initially in most circumstances.

Defining/measuring the value of clinical information.

Laboratory test results are of limited use in the absence of corresponding clinical information. The range of necessary and pertinent information is broad, but may be as narrow as knowing the patient's age and gender or the site from where a culture specimen was collected, up to the knowledge of the complete clinical history and physical examination for proper interpretation of a test result. Several issues are involved in the utilization of the clinical laboratory from the perspective of clinical appropriateness. In this article, we try to define and elaborate on how critical clinical information is for the pathologists and clinicians alike with the ultimate goal of optimal patient care.

[Pharmaceutical patents and the accessibility of drugs in Brazil]. / Patentes farmaceuticas e acessibilidade aos medicamentos no Brasil.

Passage of Patent Law 9279/96, in effect since April 1997, has made relations between pharmaceutical patents and accessibility to medicine in Brazil complex. Under the new law, patents may extend to chemical inventions (products and process) and transgenic microorganisms. The issue is analyzed from two specific yet inter-related approaches: science and technology policy and health-care policy. The conclusion draws attention to the main future consequences of current international trends, both legal and regulatory. Brazil should ready its legal framework to respond to the negative consequences that genome patenting can be expected to have on the flow of scientific information and on access to pharmaceutical drugs.

Cross-validation of modified fatness-specific bioelectrical impedance equations.

The Segal fatness-specific bioelectrical impedance (BIA) equations are useful for predicting fat-free mass (FFM). Stolarczyk et al. Proposed a modified method of averaging the two equations for individuals who are neither lean nor obese, thus eliminating the need to know % BF a priori. To cross-validate this modification, we compared FFM determined using the averaging method versus hydrostatic weighing for 76 adults. Per the averaging method, accuracy for males was excellent (r =.91, SEE = 2.7 kg, E = 2.7 kg), with 78% of individuals within +/- .5% BF predicted by hydrostatic weighing. Accuracy for females was lower (r =.88, SEE = 3.0 kg, E = 3.1 kg), with % BF of 51% within +/- 3.5% of the reference method. The relative ease and practicality of the averaging method and the results of this study indicate this method may be useful with a diverse group.

Two acute pediatric abdominal catastrophes from strangulated left paraduodenal hernias.

We present two cases of catastrophic intestinal obstruction from to strangulation of a left paraduodenal hernia (PDH). PDH is the most common internal hernia. Early diagnosis and treatment are essential because of the high morbidity and mortality associated with strangulation. Early involvement of the surgical team without an overly extensive evaluation in the emergency department is important if this diagnostic suspicion exists. PDH should also be considered when there is a history of chronic, intermittent abdominal pain of unclear cause. To our knowledge, these cases are the first described cases of sudden demise within a few hours of onset of symptoms of a left PDH.

The yield of bone marrow biopsy and culture compared with blood culture in the evaluation of HIV-infected patients for mycobacterial and fungal infections.

PURPOSE: To compare the clinical utility of bone marrow biopsy and culture specimens with blood cultures for mycobacterial and fungal infections among human immunodeficiency virus (HIV)-infected patients. PATIENTS AND METHODS: All bone marrow biopsies obtained from HIV-infected patients at the University of Alabama at Birmingham (UAB) Medical Center during 1993 to 1995 were blindly reviewed in a standardized format. Bone marrow culture results and blood culture results obtained within 6 weeks of each bone marrow study were compiled. Medical records were reviewed to determine indications for performing bone marrow biopsies, empiric or prophylactic antimicrobial therapies preceding the biopsy, and CD4 counts. RESULTS: Eighty-two bone marrow studies were obtained from 76 patients. Most were performed during the evaluation of fever, cytopenia, or weight loss. Of 55 bone marrow mycobacterial cultures, 13 yielded Mycobacterium avium complex (MAC) and 2 yielded M tuberculosis (MTB). Of 51 bone marrow fungal cultures performed, 2 yielded Cryptococcus neoformans and 1 Histoplasma capsulatum. All patients with a bone marrow culture positive for MAC had a CD4 count of 20 cells/mm3 or less. The mean CD4 count in this group (+/-95% confidence interval) (8+/-3 cells/mm3) was lower than that of culture-negative cases (41+/-25 cells/mm3); P <0.015). When bone marrow cultures and mycobacterial blood cultures were concurrently obtained, results were usually in agreement between the two sites. The mean time until the report of positive mycobacterial bone marrow cultures (22+/-5 days) was similar to that for blood cultures (24+/-3 days). Most (84%) patients with multiple mycobacterial cultures had completely concordant results (all positive or all negative). When blood or bone marrow culture yielded mycobacteria, only 29% of the corresponding bone marrow examinations revealed stainable acid-fast bacilli (AFB). In contrast, all 3 cases with positive fungal bone marrow cultures also had stainable organisms on histologic examination. CONCLUSIONS: The combined use of bone marrow biopsy and culture as well as blood cultures provide the maximum diagnostic yield when evaluating patients with AIDS for mycobacterial or fungal infections. However, when mycobacterial infections were diagnosed, bone marrow results seldom provided more immediate or specific information than lysis centrifugation blood cultures. A single lysis centrifugation blood culture should be the first step in the routine evaluation of HIV-infected patients when disseminated MAC infection is suspected.