[Cell saver devices in coronary revascularization surgery without extracorporeal circulation reduce transfusion requirements]. / El Recuperador Celular (Cell Saver) en cirugía de revascularización coronaria sin circulación extracorpóea reduce necesidades transfusionales.

OBJECTIVES: To analyze the effectiveness of a cell saver device in reducing transfusion requirements in patients undergoing off-pump coronary artery bypass surgery. PATIENTS AND METHODS: Fifty-six consecutive ASA class 4-5 patients who underwent coronary surgery without extracorporeal circulation in our cardiac surgery department between June 2004 and January 2005 were included in this retrospective study; the series comprised 28 patients who received conventional management (control group) without use of the cell saver device and 28 who received cell saver treatment. Variables analyzed were preoperative and discharge hemoglobin levels and hematocrit values, age, weight, height, ejection fraction, packed red blood cells transfused, exitus, and adverse events. RESULTS: The groups were similar with respect to preoperative characteristics. Fewer patients in the cell saver group required transfusions (6 vs 18 in the control group; relative risk 0.33, 95% confidence interval, 0.16-0.71). The mean amount of packed red cells transfused was greater in the control group than in the cell saver group (2.5 L vs 1.2 L, P = 0.03). No deaths or adverse events occurred in either group. CONCLUSIONS: The routine use of a cell saver device during off-pump coronary artery bypass surgery reduces the need for postoperative transfusions and is not associated with adverse events. Cell saver devices should be used routinely, especially in situations where the ability to provide blood transfusions may be compromised.

Evaluation of drug efficacy by using animal models or in vitro systems.

The efficacy of most therapeutic and prophylactic protocols against Pneumocystis carinii pneumonia used in human patients has been tested in animal models, especially in the corticosteroid-treated rat. The advantages and drawbacks of this model have been examined in brief in Chapter 1 of this section. More recently, the nude rat, intratracheally inoculated with Pneumocystis, was used to test new anti-microbian molecules for their anti-Pneumocystis activity. In vitro systems, co-cultures of Pneumocystis with feeder cells as well as axenic cultures, were also used many times for drug screening. In this paper, the most used in vivo or in vitro drug screening systems are described. Moreover, as immunocompromised individuals, AIDS patients, especially, are often infected simultaneously by several infectious agents, a recent co-infection model is described.

Development of a high throughput in vitro toxicity screen predictive of high acute in vivo toxic potential.

At an early stage of drug discovery high throughput screens are an invaluable tool to de-select compounds with undesirable properties. A high throughout in vitro toxicity screen has been developed and validated to identify compounds that have a high potential to be acutely toxic in vivo. This screen is based on treating Chinese hamster ovary (CHO) cells with test compounds for 24 h and then determining the degree of cytotoxicity by the reduction of Resazurin. Twenty-six structurally unrelated compounds were chosen that spanned a range of acute LD(50) values and mechanisms of toxicity. The acute LD(50) values (intraperitoneal and intravenous routes) from rat and mouse were taken from the RTECS database. Experimentally derived in vitro IC(35) results were compared to the 'most toxic' (lowest) LD(50) values for each compound. The resulting correlation was statistically significant (r=0.8475). However, due to the scatter of the data points, it was considered not appropriate to rank compounds according to their degree of in vivo toxicity on the basis of the in vitro result. However, by defining cut-off concentrations for both the in vivo (LD(50)) and the in vitro (IC(35)) values it was possible, using the in vitro result (IC(35) <10 microM), to identify compounds that had a high potential to be acutely toxic in vivo ('most toxic' LD(50) <25 micromol/kg). Further development led to a high throughput screen capable of giving a 'Yes', 'No' or 'Borderline' classification as to whether a compound has a high acute in vivo toxic potential. This screen is highly specific (no false positive classifications) and has a sensitivity of approximately 80%. This is deemed acceptable for a first tier toxicity screen at an early stage in the drug discovery process. Transfer of this screen from GlaxoSmithKline UK to sites in Italy, Spain and the USA resulted in very similar findings indicating the inter-laboratory robustness of this screen and therefore the ability to compare results across the GlaxoSmithKline sites.

[Maxillary sinus lymphoma associated with HIV infection]. / Linfoma de seno maxilar asociado a infección VIH.

We present the case of a patient with positive antibodies against the human immunodeficiency virus, erroneously diagnosed, on the basis of conventional radiology and clinical signs, as right maxillary sinusitis. CT showed a tumoral mass at the maxillary sinus, with histology of highly malignant Non-Hodgkin's Lymphoma (NHL). The chemotherapy (CHOP) resulted in clinical remission, but the appearance of acute myelodepression forced the staggering of cycles, resulting in recurrency of the disease. The addition of G-CSF allowed to continue chemotherapy at full doses, again with positive responses. The lymphoma located at the maxillary sinus is extremely rare in patients with AIDS. Chemotherapy is complicated by myelodepression and the frequent development of opportunistic infections. The use of stimulant factors of the hematopoietic growth facilitates the management of AIDS-associated neoplasias.

A reorganized Candida albicans DNA sequence promoting homologous non-integrative genetic transformation.

In order to develop plasmids adequate for non-integrative genetic transformation of Candida albicans, a DNA fragment of 15.3 kb was cloned from this organism on the basis of its capacity to convert the integrative Saccharomyces cerevisiae vector YIp5 into a non-integrative one. Southern hybridization analysis, carried out with a labelled DNA probe of 3.6 kb derived from the cloned fragment, showed that it consisted of C. albicans DNA, the hybridization pattern indicating that the corresponding sequences were homologous to several chromosomal regions. The size of the C. albicans DNA promoting autonomous replication in S. cerevisiae was substantially reduced by subcloning. A 5.1 kb subfragment, defined by BamHI and SalI restriction sites, retained autonomous replication sequences (ARS) functional in the heterologous S. cerevisiae system and in C. albicans, when inserted in plasmid constructions that carried a S. cerevisiae trichodermin-resistance gene (tcm1) as selection marker. C. albicans transformants were both of the integrative and the non-integrative type and the plasmids recovered from the latter very often carried a reorganized ARS, indicating that recombination of the inserted ARS DNA had occurred in the homologous host. Successive reorganizations of the ARS insert in C. albicans eventually led to a more stable and much smaller fragment of 687 bp that was subsequently recovered unchanged from transformants. Sequence analysis of the 687 bp fragment revealed four 11-base blocks, rich in A+T, that carried the essential consensus sequence considered relevant for yeast ARS elements in addition to other features also described as characteristic of yeast replication origins.

In vitro pharmacodynamic parameters of sordarin derivatives in comparison with those of marketed compounds against Pneumocystis carinii isolated from rats.

Pneumocystis carinii pneumonia remains one of the most serious complications of immunosuppressed patients. In this study, the in vitro pharmacodynamic parameters of four sordarin derivatives (GM 191519, GM 237354, GM 193663, and GM 219771) have been evaluated by a new quantitative approach and compared with the commercially available drugs pentamidine, atovaquone, and trimethoprim-sulfamethoxazole (TMP-SMX). In vitro activities and in vivo therapeutic efficacies of sordarin derivatives against P. carinii were also evaluated. In vitro activity was determined by the broth microdilution technique, comparing the total number of microorganisms in treated and drug-free cultures by using Giemsa staining. The in vitro maximum effect (E(max)), the drug concentrations to reach 50% of E(max) (EC(50)), and the slope of the dose-response curve were then estimated by the Hill equation (E(max) sigmoid model). Sordarin derivatives were the most potent agents against P. carinii, with EC(50)s of 0.00025, 0.0007, 0.0043, and 0. 025 microg/ml for GM 191519, GM 237354, GM 193663, and GM 219771, respectively. The EC(50)s of pentamidine, atovaquone, and TMP-SMX were 0.025, 0.16, and 26.7/133.5 microg/ml, respectively. The results obtained with this approach showed GM 237354 and GM 191519 to be approximately 35- and 100-fold more active in vitro than pentamidine, the most active marketed compound. All sordarin derivatives tested were at least 5,000-fold more active in vitro than TMP-SMX. The three sordarin derivatives tested in vivo-GM 191519, GM 237354, and GM 219771-showed a marked therapeutic efficacy, defined as reduction of cyst forms per gram of lung. GM 191519 was the most potent (daily dose reducing 50% of the P. carinii burden in the lungs [ED(50)], 0.05 mg/kg/day) followed by GM 237354 and GM 219771 (ED(50)s, 0.30 and 0.49 mg/kg/day, respectively). Good agreement between in vitro parameters and in vivo outcome was obtained when P. carinii pneumonia in rats was treated with sordarin derivatives.

Antifungal activities and cytotoxicity studies of six new azasordarins.

GW 471552, GW 471558, GW 479821, GW 515716, GW 570009, and GW 587270 are members of a new family of sordarin derivatives called azasordarins. The in vitro activities of these compounds were evaluated against clinical isolates of yeasts, including Candida albicans, Candida non-albicans, and Cryptococcus neoformans strains. Activities against Pneumocystis carinii, Aspergillus spp., less common molds, and dermatophytes were also investigated. Azasordarin derivatives displayed significant activities against the most clinically important Candida species, with the exception of C. krusei. Against C. albicans, including fluconazole-resistant strains, MICs at which 90% of the isolates tested are inhibited (MIC(90)s) were 0.002 microg/ml with GW 479821, 0.015 microg/ml with GW 515716 and GW 587270, and 0.06 microg/ml with GW 471552, GW 471558, and GW 570009. The MIC(90)s of GW 471552, GW 471558, GW 479821, GW 515716, GW 570009, and GW 587270 were 0.12, 0.12, 0.03, 0.06, 0.12, and 0.06 microg/ml, respectively, against C. tropicalis and 4, 0.25, 0.06, 0.25, 0.5, and 0.5 microg/ml, respectively, against C. glabrata. In addition, some azasordarin derivatives (GW 479821, GW 515716, GW 570009, and GW 58720) were active against C. parapsilosis, with MIC(90)s of 2, 4, 4, and 1 microg/ml, respectively. The compounds were extremely potent against P. carinii, showing 50% inhibitory concentrations of 16 microg/ml). These azasordarin derivatives also showed significant activity against emerging fungal pathogens, which affect immunocompromised patients, such as Rhizopus arrhizus, Blastoschizomyces capitatus, and Geotrichum clavatum. Against these organisms, the MICs of GW 587270 ranged from 0.12 to 1 microg/ml, those of GW 479821 and GW 515716 ranged from 0.12 to 2 microg/ml, and those of GW 570009 ranged from 0.12 to 4 microg/ml. Against Fusarium oxysporum, Scedosporium apiospermum, Absidia corymbifera, Cunninghamella bertholletiae, and dermatophytes, GW 587270 was the most active compound, with MICs ranging from 4 to 16 microg/ml. Against Aspergillus spp., the MICs of the compounds tested were higher than 16 microg/ml. The in vitro selectivity of azasordarins was investigated by cytotoxicity studies performed with five cell lines and primary hepatocytes. Concentrations of compound required to achieve 50% inhibition of the parameter considered (Tox(50)s) of GW 570009, GW 587270, GW 479281, and GW 515716 in the cell lines ranged from 60 to 96, 49 to 62, 24 to 36, and 16 to 38 microg/ml, respectively. The cytotoxicity values of GW 471552 and GW 471558 were >100 microg/ml for all cell lines tested. Tox(50)s on hepatocytes were in the following order: GW 471558 > GW 471552 > GW 570009 > GW 587270 > GW 515716 > GW 479821, with values ranging from higher than 100 microg/ml to 23 microg/ml. The cytotoxicity results obtained with fully metabolizing rat hepatocytes were in total agreement with those obtained with cell lines. In summary, the in vitro activities against important pathogenic fungi and the selectivity demonstrated in mammalian cell lines justify additional studies to determine the clinical usefulness of azasordarins.

Sordarins: in vitro activities of new antifungal derivatives against pathogenic yeasts, Pneumocystis carinii, and filamentous fungi.

GM 193663, GM 211676, GM 222712, and GM 237354 are new semisynthetic derivatives of the sordarin class. The in vitro antifungal activities of GM 193663, GM 211676, GM 222712, and GM 237354 against 111 clinical yeast isolates of Candida albicans, Candida kefyr, Candida glabrata, Candida parapsilosis, Candida krusei, and Cryptococcus neoformans were compared. The in vitro activities of some of these compounds against Pneumocystis carinii, 20 isolates each of Aspergillus fumigatus and Aspergillus flavus, and 30 isolates of emerging less-common mold pathogens and dermatophytes were also compared. The MICs of GM 193663, GM 211676, GM 222712, and GM 237354 at which 90% of the isolates were inhibited (MIC90s) were 0.03, 0.03, 0.004, and 0.015 microg/ml, respectively, for C. albicans, including strains with decreased susceptibility to fluconazole; 0.5, 0.5, 0.06, and 0.12 microg/ml, respectively, for C. tropicalis; and 0.004, 0.015, 0.008, and 0.03 microg/ml, respectively, for C. kefyr. GM 222712 and GM 237354 were the most active compounds against C. glabrata, C. parapsilosis, and Cryptococcus neoformans. Against C. glabrata and C. parapsilosis, the MIC90s of GM 222712 and GM 237354 were 0.5 and 4 microg/ml and 1 and 16 microg/ml, respectively. The MIC90s of GM 222712 and GM 237354 against Cryptococcus neoformans were 0.5 and 0.25 microg/ml, respectively. GM 193663, GM 211676, GM 222712, and GM 237354 were extremely active against P. carinii. The efficacies of sordarin derivatives against this organism were determined by measuring the inhibition of the uptake and incorporation of radiolabelled methionine into newly synthesized proteins. All compounds tested showed 50% inhibitory concentrations of <0.008 microg/ml. Against A. flavus and A. fumigatus, the MIC90s of GM 222712 and GM 237354 were 1 and 32 microg/ml and 32 and >64 microg/ml, respectively. In addition, GM 237354 was tested against the most important emerging fungal pathogens which affect immunocompromised patients. Cladosporium carrioni, Pseudallescheria boydii, and the yeast-like fungi Blastoschizomyces capitatus and Geotrichum clavatum were the most susceptible of the fungi to GM 237354, with MICs ranging from /=2 microg/ml. In summary, we concluded that some sordarin derivatives, such as GM 222712 and GM 237354, showed excellent in vitro activities against a wide range of pathogenic fungi, including Candida spp., Cryptococcus neoformans, P. carinii, and some filamentous fungi and emerging invasive fungal pathogens.