Epidemiology of fungal infection in COVID 19 in Spain during 2020 and 2021: a nationwide study

We realize a nationwide population-based retrospective study to analyze the characteristics and risk factors of fungal co-infections in COVID-19 hospitalized patients as well as describe their causative agents in the Spanish population in 2020 and 2021. Data were obtained from records in the Minimum Basic Data Set of the National Surveillance System for Hospital Data in Spain, provided by the Ministry of Health, and annually published with two years lag. The assessment of the risk associated with the development of healthcare-associated fungal co-infections was assessed using an adjusted logistic regression model. The incidence of fungal co-infection in COVID-19 hospitalized patients was 1.41%. The main risk factors associated were surgery, sepsis, age, male gender, obesity, and COPD. Co-infection was associated with worse outcomes including higher in-hospital and in ICU mortality, and higher length of stay. Candida spp. and Aspergillus spp. were the microorganisms more frequent. This is the first study analyzing fungal coinfection at a national level in hospitalized patients with COVID-19 in Spanish population and one of the few studies available that demonstrate that surgery was an independent risk factor of Aspergillosis coinfection in COVID-19 patients.

Regulation of mouse exploratory behaviour by irradiance and cone-opponent signals

BACKGROUND

Animal survival depends on the ability to adjust behaviour according to environmental conditions. The circadian system plays a key role in this capability, with diel changes in the quantity (irradiance) and spectral content ('colour') of ambient illumination providing signals of time-of-day that regulate the timing of rest and activity. Light also exerts much more immediate effects on behaviour, however, that are equally important in shaping daily activity patterns. Hence, nocturnal mammals will actively avoid light and dramatically reduce their activity when light cannot be avoided. The sensory mechanisms underlying these acute effects of light are incompletely understood, particularly the importance of colour.

RESULTS

To define sensory mechanisms controlling mouse behaviour, we used photoreceptor-isolating stimuli and mice with altered cone spectral sensitivity (Opn1mwR), lacking melanopsin (Opn1mwR; Opn4-/-) or cone phototransduction (Cnga3-/-) in assays of light-avoidance and activity suppression. In addition to roles for melanopsin-dependent irradiance signals, we find a major influence of spectral content in both cases. Hence, remarkably, selective increases in S-cone irradiance (producing a blue-shift in spectrum replicating twilight) drive light-seeking behaviour and promote activity. These effects are opposed by signals from longer-wavelength sensitive cones, indicating a true spectrally-opponent mechanism. Using c-Fos-mapping and multielectrode electrophysiology, we further show these effects are associated with a selective cone-opponent modulation of neural activity in the key brain site implicated in acute effects of light on behaviour, the subparaventricular zone.

CONCLUSIONS

Collectively, these data reveal a mechanism whereby blue-shifts in the spectrum of environmental illumination, such as during twilight, promote mouse exploratory behaviour.

Epidemiology of bacterial co-infections and risk factors in COVID-19-hospitalized patients in Spain: a nationwide study

BACKGROUND

We performed a nationwide population-based retrospective study to describe the epidemiology of bacterial co-infections in coronavirus disease 2019 (COVID-19)-hospitalized patients in Spain in 2020. We also analyzed the risk factors for co-infection, the etiology and the impact in the outcome.

METHODS

Data were obtained from records in the Minimum Basic Data Set (MBDS) of the National Surveillance System for Hospital Data in Spain, provided by the Ministry of Health and annually published with 2 years lag. COVID-19 circulated in two waves in 2020: from its introduction to 31st June and from 1st July to 31st December. The risk of developing a healthcare-associated bacterial co-infection and the risk for in-hospital and intensive care unit (ICU) mortality in co-infected patients was assessed using an adjusted logistic regression model.

RESULTS

The incidence of bacterial co-infection in COVID-19 hospitalized patients was 2.3%. The main risk factors associated with bacterial co-infection were organ failure, obesity and male sex. Co-infection was associated with worse outcomes including higher in-hospital, in-ICU mortality and higher length of stay. Gram-negative bacteria caused most infections. Causative agents were similar between waves, although higher co-infections with Pseudomonas spp. were detected in the first wave and with Haemophilus influenzae and Streptococcus pneumoniae in the second.

CONCLUSIONS

Co-infections are not as common as those found in other viral respiratory infections; therefore, antibiotics should be used carefully. Screening for actual co-infection to prescribe antibiotic therapy when required should be performed.

Endothelial dysfunction is an early indicator of sepsis and neutrophil degranulation of septic shock in surgical patients

Background

Stratification of the severity of infection is currently based on the Sequential Organ Failure Assessment (SOFA) score, which is difficult to calculate outside the ICU. Biomarkers could help to stratify the severity of infection in surgical patients.

Methods

Levels of ten biomarkers indicating endothelial dysfunction, 22 indicating emergency granulopoiesis, and six denoting neutrophil degranulation were compared in three groups of patients in the first 12 h after diagnosis at three Spanish hospitals.

Results

There were 100 patients with infection, 95 with sepsis and 57 with septic shock. Seven biomarkers indicating endothelial dysfunction (mid‐regional proadrenomedullin (MR‐ProADM), syndecan 1, thrombomodulin, angiopoietin 2, endothelial cell‐specific molecule 1, vascular cell adhesion molecule 1 and E‐selectin) had stronger associations with sepsis than infection alone. MR‐ProADM had the highest odds ratio (OR) in multivariable analysis (OR 11·53, 95 per cent c.i. 4·15 to 32·08; P = 0·006) and the best area under the curve (AUC) for detecting sepsis (0·86, 95 per cent c.i. 0·80 to 0·91; P < 0·001). In a comparison of sepsis with septic shock, two biomarkers of neutrophil degranulation, proteinase 3 (OR 8·09, 1·34 to 48·91; P = 0·028) and lipocalin 2 (OR 6·62, 2·47 to 17·77; P = 0·002), had the strongest association with septic shock, but lipocalin 2 exhibited the highest AUC (0·81, 0·73 to 0·90; P < 0·001).

Conclusion

MR‐ProADM and lipocalin 2 could be alternatives to the SOFA score in the detection of sepsis and septic shock respectively in surgical patients with infection.

Antifungal treatment with echinocandins: a 10-year clinical experience

OBJECTIVE

The number of studies evaluating the use of echinocandins, whether or not its indication meets international guidelines, in clinical practice is limited. The objective of the present study was to determine the use of echinocandins in a tertiary Spanish hospital in 10 years of clinical practice, and to evaluate its impact on prognosis.

METHODS

This retrospective study involved adult nonneutropenic ill patients with suspicion of fungal invasion who started treatment with echinocandins between 2006 and 2015.

RESULTS

The number of patients treated with echinocandins was 153, and candidemia was detected thereafter in 25.5%. Factors associated with in-hospital mortality in patients receiving echinocandins were: sex male, septic shock, Charlson comorbidity index, and total stay at the hospital. In-hospital mortality after 7, 30 and 90 days was 13.7%, 24.8%, and 56.8%, respectively. From patients receiving echinocandins, 98 did no show multifocal colonization, 50 had Candida score <2.5, and 49 did not meet Ostrosky-Zeichner prediction rule. A total of 19 patients did not show any of these 3 potential risk factors for candidemia.

CONCLUSIONS

The use of echinocandins in 10 years of clinical practice in our tertiary hospital has been performed according to international guidelines; however, candidemia was only diagnosed thereafter in only 25.5% of cases. Furthermore, according to our results, the adequate use of echinocandins seems not to be associated with reduced mortality rates. Further studies, involving a large cohort of patients and more hospitals, are required to corroborate these results.

Ability to predict the development of surgical site infection in cardiac surgery using the Australian Clinical Risk Index versus the National Nosocomial Infections Surveillance-derived Risk Index

Surgical site infection (SSI) is a major infectious complication that increases mortality, morbidity, and healthcare costs. There are scores attempting to classify patients for calculating SSI risk. Our objectives were to validate the Australian Clinical Risk Index (ACRI) in a European population after cardiac surgery, comparing it against the National Nosocomial Infections Surveillance-derived risk index (NNIS) and analyzing the predictive power of ACRI for SSI in valvular patients. All the patients that who underwent cardiac surgery in a tertiary university hospital between 2011 and 2015 were analyzed. The patients were divided into valvular and coronary groups, excluding mixed patients. The ACRI score was validated in both groups and its ability to predict SSI was compared to the NNIS risk index. We analyzed 1,657 procedures. In the valvular patient group (n: 1119), a correlation between the ACRI score and SSI development (p < 0.05) was found; there was no such correlation with the NNIS index. The area under the receiver-operating characteristic curve (AUC) was 0.64 (confidence interval [CI] 95%, 0.5-0.7) for ACRI and 0.62 (95% CI, 0.5-0.7) for NNIS. In the coronary group (n: 281), there was a correlation between ACRI and SSI but no between NNIS and SSI. The ACRI AUC was 0.70 (95% CI, 0.5-0.8) and the NNIS AUC was 0.60 (95% CI, 0.4-0.7). The ACRI score has insufficient predictive power, although it predicts SSI development better than the NNIS index, fundamentally in coronary artery bypass grafting (CABG). Further studies analyzing determining factors are needed.

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016

[This corrects the article DOI: 10.1186/s13054-016-1208-6.].

Modulation of autoimmune arthritis severity in mice by apolipoprotein E (ApoE) and cholesterol

Apolipoprotein E (ApoE) deficiency promoted an exacerbation of autoimmune arthritis in mice by inducing proinflammatory immune responses. In this study we analysed the contribution of hypercholesterolaemia and/or the absence of ApoE anti-inflammatory properties, unrelated to its function in the control of cholesterol metabolism, towards the acceleration of arthritis in these mutant animals. The induction and severity of collagen type II-induced arthritis (CIA) were compared for B10.RIII wild-type (WT), B10.RIII.ApoE^+/- , B10.RIII.ApoE^-/- and B10.RIII.low-density lipoprotein receptor (LDLR^-/- ) mice with different concentrations of circulating ApoE and cholesterol. A 50-70% reduction in serum levels of ApoE was observed in heterozygous B10.RIII.ApoE^+/- mice in comparison to B10.RIII.WT, although both strains of mice exhibited similar circulating lipid profiles. This ApoE reduction was associated with an increased CIA severity that remained lower than in homozygous B10.RIII.ApoE^-/- mice. An important rise in circulating ApoE concentration was observed in hypercholesterolaemic B10.RIII.LDLR^-/- mice fed with a normal chow diet, and both parameters increased further with an atherogenic hypercholesterolaemic diet. However, the severity of CIA in B10.RIII.LDLR^-/- mice was similar to that of B10.RIII.WT controls. In conclusion, by comparing the evolution of CIA between several strains of mutant mice with different levels of serum ApoE and cholesterol, our results demonstrate that both hypercholesterolaemia and ApoE regulate the intensity of in-vivo systemic autoimmune responses.

Angiogenic therapy for cardiac repair based on protein delivery systems

Cardiovascular diseases remain the first cause of morbidity and mortality in the developed countries and are a major problem not only in the western nations but also in developing countries. Current standard approaches for treating patients with ischemic heart disease include angioplasty or bypass surgery. However, a large number of patients cannot be treated using these procedures. Novel curative approaches under investigation include gene, cell, and protein therapy. This review focuses on potential growth factors for cardiac repair. The role of these growth factors in the angiogenic process and the therapeutic implications are reviewed. Issues including aspects of growth factor delivery are presented in relation to protein stability, dosage, routes, and safety matters. Finally, different approaches for controlled growth factor delivery are discussed as novel protein delivery platforms for cardiac regeneration.

Genomics in cardiovascular diseases: analysis of the importance of the toll-like receptor signaling pathway

The development of techniques for genomics study makes it possible for us to further our knowledge about the physiopathology of various immunological or infectious diseases. These techniques improve our understanding of the development and evolution of such diseases, including those of cardiovascular origin, whilst they help to bring about the design of new therapeutic strategies. We are reviewing the genetic alterations of immunity in said field, and focusing on the signaling pathway of toll-like receptors because not only does this play a decisive role in response to microorganisms, it is also heavily involved in modulating the inflammatory response to tissue damage, a side effect of numerous cardiovascular diseases. These alterations in tissue homeostasis are present under a wide range of circumstances, such as reperfusion ischemia (myocardial infarction) phenomena, arteriosclerosis, or valvulopathy.

Bioequivalence of acenocoumarol in chilean volunteers: an open, randomized, double-blind, single-dose, 2-period, and 2-sequence crossover study for 2 oral formulations

The aim of this study was to compare the bioavailability of an oral formulation of the coumarin derivative-vitamine K antagonist acenocoumarol (Acebron™ 4 mg, Test) with the reference formulation (Neo-Sintrom™ 4 mg). We performed a single-dose, double-blind, fasting, 2-period, 2-sequence, crossover study design. Plasma concentrations of acenocoumarol were determined using a validated UPLC-MS/MS method. 24 healthy Chilean volunteers (11 male, 13 female) were enrolled and all of them completed the study. Adverse events were monitored throughout the study. The values of the pharmacokinetic parameters were (mean ± SD): AUC0-24 =1 364.38±499.26 ngxh/mL for the test and 1 328.39±429.20 ngxh/mL for the reference; AUC0-∞ =1 786.00±732.85 ngxh/mL for the test and 1 706.71±599.66 ngxh/mL for the reference; Cmax =180.69±35.11 ng/mL with a Tmax of 1.83±0.95 h for the test and 186.97±38.21 ng/mL with a Tmax of 2.19±0.83 h for the reference. Regarding half life measurements, the mean ± SD of t1/2 were 11.84±4.54 h for the test and 11.08±3.28 h for the reference. The 90% confidence intervals for the test/reference ratio using logarithmic transformed data were 97.89-100.87%, 98.62-101.99% and 98.64-102.38% for Cmax, AUC0-t(24) and AUC0-∞. There were no significant differences in pharmacokinetic parameters between groups.The results obtained in this study lead us to conclude, based on FDA criteria, that the test acenocoumarol formulation (Acebron™, 4 mg tablets) is bioequivalent to the reference product (Neo-Sintrom™, 4 mg tablets).

[Central venous pressure, rewarming time, and total fluid replacement volume are predictors of mortality and complications after cardiac surgery]

OBJECTIVE

To analyze the influence of early (first day) postoperative factors on postoperative course in patients who have undergone heart surgery.

PATIENTS AND METHODS

A cross-sectional study of consecutively enrolled heart surgery patients was designed. We recorded central venous pressure, time required for rewarming to a core temperature of 35.5degrees C, and total fluids administered in 24 hours. We then analyzed their influence on mortality and cardiac, pulmonary, and renal complications.

RESULTS

Two hundred thirty-six patients were included. Central venous pressure over 18 mm Hg, time to rewarming over 6 hours, and administration of more than 5 L of fluids in the first 24 hours were factors associated with increased mortality and the development of cardiovascular, pulmonary, and renal complications.

CONCLUSIONS

Central venous pressure, rewarming time, and fluid replacement volume required on the first day are predictors of postoperative course.

The inflammatory response to colloids and crystalloids used for pump priming during cardiopulmonary bypass

BACKGROUND

Systemic inflammatory response frequently occurs after coronary artery bypass surgery and is strongly correlated with the risk of postoperative morbidity and mortality. This study tests the hypothesis that the priming of the extracorporeal circuit with colloid solutions results in less inflammation in patients undergoing cardiac surgery than priming with crystalloid solutions.

METHODS

A prospective, randomized study was designed. Forty-four patients undergoing elective coronary artery bypass grafting were randomly allocated to one of two groups: 22 patients primed with Ringer's lactate (RL) solution and 22 patients primed with gelatin-containing solution during the surgery. Plasma levels of interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-alpha, C-reactive protein (CRP) and, complement 4 were measured during the surgical intervention and over the following 48 postoperative hours. Cytokine levels were measured by enzyme-linked assays from plasma samples obtained at specific time points pre- and post-operatively.

RESULTS

In both groups the serum levels of the pro-inflammatory cytokines (IL-6, IL-8, TNF-alpha), CRP, complement 4, and leukocytes increased significantly over the baseline, although no significant differences were observed between the two groups. The operation time, blood loss, need for inotropic support, extubation time, and length of intensive care unit stay did not differ significantly between the two groups.

CONCLUSION

Priming with gelatin vs. RL produces no significant differences in the inflammatory response in patients undergoing coronary artery bypass grafting with cardiopulmonary bypass.

Prick-test evaluation to anaesthetics in patients attending a general allergy clinic

BACKGROUND AND OBJECTIVES

To analyse the prevalence of positive prick-tests to all medicaments normally checked in allergy units when a patient is suspected of being allergic to anaesthetics. To establish the degree of agreement between the antecedents of a previous history of an allergic reaction to a medicament and the positive result, or not, to the specific prick-test for the said medicament.

METHODS

This was a prospective study, during 2003 and 2004, which analysed 473 patients referred by their doctors to allergy units to make retrospective diagnoses of an allergy to a drug. The prick-test was done using the undiluted drug. All patients were tested for 41 drugs. These include antibiotics, trimethoprim-sulphamethoxazole, non-steroidal anti-inflammatory drugs (NSAIDs) and perioperative drugs (PD): neuromuscular blocking drugs, latex, iodine, local anaesthetics, hypnotics, opioids and coadjuvants. Cohen's Kappa Index was used to determine the degree of agreement.

RESULTS

71.5% of patients studied presented a positive prick-test. The largest number of positive cases was found in antibiotics (56.4%), followed by PD (15.6%), NSAIDs (14.4%) and trimethoprim-sulphamethoxazole (12.7%). Among PD, the highest prevalence of positive prick-tests was found for neuromuscular blocking drugs (5.3%). Agreement between the substance suspected of causing the allergic reaction and the positive prick-test was excellent for penicillin (Kappa = 0.74) and other antibiotics (Kappa = 0.721) and good for NSAIDs (Kappa = 0.47) and iodine (Kappa = 0.54).

CONCLUSIONS

The prevalence of patients with positive prick-tests to PD occurred in 15.6% in this prospective cohort. Neuromuscular blocking drugs were found to have the highest prevalence of positive prick-tests. There is positive agreement when the substance responsible for the allergic reaction is suspected, otherwise agreement is low.

Prevalence of positive prick test to anaesthetic drugs in the surgical population

Prevalence of patients with positive prick tests to anaesthetics occurred in 4.7% of the surgical population.

[Postoperative analgesia in cardiac surgery: spinal versus intravenous morphine]

OBJECTIVE

To compare the effects of spinal and intravenous administration of morphine to supplement anesthesia with remifentanil in terms of analgesia during early postoperative recovery and considering time until extubation.

MATERIAL AND METHODS

This prospective, randomized, blinded trial enrolled 59 patients scheduled for cardiac surgery. The patients were assigned to receive either a spinal infusion of morphine (15 microg x Kg(-1)) or an intravenous infusion (0.3 mg x Kg(-1)). Anesthesia was maintained with 0.15 to 0.50 microg x Kg(-1) x min(-1) of remifentanil and 2 to 4 mg x Kg(-1) x h(-1) of propofol in perfusion. After the period of extracorporeal circulation, all patients were given an intravenous infusion of 30 mg of ketorolac. Later intravenous ketorolac was ministered at a dose of 30 mg per 8 hours; intravenous morphine (bolus dose of 3 mg) was also administered until pain was relieved.

RESULTS

The same quality of postoperative analgesia and anesthetic recovery was achieved with both spinal and intravenous administration. The incidence of side effects was also similar. Likewise, the extubation times were similar in the 2 groups (spinal infusion group: 294.5 [SD, 150.5] minutes; intravenous group: 325.0 [139.9] minutes; P>0.05). Less postoperative intravenous morphine was administered in the first 24 hours to patients in the spinal morphine group (P<0.05) and fewer patients in that group required intravenous morphine boluses (P<0.05).

CONCLUSIONS

Our study suggests that spinal morphine does not offer advantages over intravenous morphine with regard to postoperative analgesia, hemodynamic stability and respiratory parameters, time until extubation, or adverse effects.

[Evaluation of the withdrawal of ACE inhibitors in coronary artery surgery]

During cardiac surgery, as a result of surgical aggression, myocardial ischaemia and cardiopulmonary bypass, the renin-angiotensin-aldosterone mechanism is intensely activated. Our aim is to document whether, in the case of patients undergoing chronic treatment with lisinopril, the non-withdrawal of this inhibitor's administration before cardiac surgery and the administering of a last dose on the day of the operation are associated with coronary haemodynamic alterations. A study was made of 18 patients submitted to myocardial revascularization under extracorporeal circulation and distributed in two groups: group A) without ACE inhibitorsplacebo, group B) with ACE inhibitors (Lisinopril). Coronary blood flow (CBF) was determined by inverted thermodilution via Baim's catheter. Coronary and metabolic haemodynamic values were calculated. Lisinopril had no significant influence on the CBF or on the other above-mentioned values. Therefore, it is not necessary to withdraw ACE inhibitors in cardiac surgery interventions.

Apoptotic cell death and genetic control in graft coronary artery disease in heart transplant

AIM

Apoptosis is a type of programmed cell death whereby, immunologic, genetic and biochemical mechanisms are involved in its control. On the other hand, graft coronary artery disease is the most important restrictive factor for the long-term survival of heart transplantation. The purpose of this study is to analyse both apoptotic cell lesions in transplanted patients that present coronary artery disease.

METHODS

From August 1984 until December 1996, 148 heart transplants were carried out in the Clínica Universitaria de Navarra. In 102 patients, annual coronary angiography was performed, reaching a diagnosis of coronary artery disease in 30 patients. Study of apoptotic cell death was done in the tissue of endomyocardial biopsies on all patients by means of the TUNEL technique. Procedures of immunohistochemistry with antibodies antic-myc, p53 and bcl-2 were carried out and results were compared with a control group of 30 patients with homogeneous characteristics.

RESULTS

All patients with coronary artery disease showed apoptotic cardiomyocytes, 13 patients to a mild degree, 14 to a moderate degree and 3 to a severe degree, while in the control group apoptosis was found only to a mild degree in 8 patients, obtaining a very significant statistical difference (p<0.0001). The expression of analysed oncoproteins was null in the 2 groups.

CONCLUSION

Myocardial apoptosis is a constant finding in transplanted patients with coronary artery disease. We have not seen any correlation between the apoptotic process and genetic mechanisms.

[Right heart support during coronary artery bypass grafting without cardiopulmonary bypass]

BACKGROUND AND OBJECTIVES

Exposure of lateral and inferior coronary vessels during off-pump coronary artery bypass grafting may cause significant hemodynamic compromise due to right ventricular compression when tilting the heart. Some new right ventricular assistance devices have been developed in order to avoid this problem but only a few series have been published. A preliminary experience with a right heart circulatory support system is reported.

METHODS

A total of eight patients underwent off-pump coronary artery bypass grafting using a right heart support device. Technical procedure and clinical outcome are analyzed.

RESULTS

The right heart circulatory support device insertion and management were performed without any complication. A total of 21 distal coronary anastomoses were completed. They were located on the anterior descending artery(8), circumflex branches(6), diagonal branches(2), posterior descending artery(3) and right coronary artery(2). The right ventricular support device delivered flow at a medium rate of 2.2 L/min, providing hemodynamic stability when tilting the heart and exposing the coronary arteries.

CONCLUSIONS

The use of right heart support devices is a simple and low risk procedure which may facilitate surgical anastomoses on lateral and inferior epicardial vessels during off-pump coronary artery surgery.

Bilateral diaphragmatic paralysis after open heart surgery

The purpose of the present case report is to present a case of bilateral diaphragmatic paralysis as a complication of open-heart surgery. A 47-year-old male was operated for aortic and mitral valve replacement. After discontinuation of sedation, bilateral diaphragmatic paralysis as well as motor and sensitive dysfunction in the four extremities was observed. The patient remained with mechanical ventilation support for twenty months. Two years after the operation a complete normalisation of the diaphragmatic motion was observed. Although uncommon, bilateral diaphragmatic paralysis after open-heart surgery could take place, being necessary long term mechanical ventilation support until recovery.

Analysis of the microenvironment necessary for engraftment: role of the vascular smooth muscle-like stromal cells

This is a review of recent data concerning the phenotype of human and murine stroma, as grown in long-term cultures. Using data on cytoskeletal and extracellular matrix protein expression, a sequential model of differentiation from mesenchymal (stem) cells to vascular-smooth muscle-like stromal cells is proposed. This model would apply, at least in the mouse, to stromal cells generated from different sites of hematopoiesis (bone marrow, fetal liver, spleen, and yolk sac). The in vivo counterparts of vascular-smooth muscle-like stromal cells in the different sites of definitive hematopoiesis are discussed.

The lack of a functional p21(WAF1/CIP1) gene ameliorates progression to chronic renal failure

Partial renal ablation leads to progressive renal insufficiency and is a model of chronic renal failure from diverse causes. We find that mice develop functional and morphologic characteristics of chronic renal failure after partial renal ablation, including glomerular sclerosis, systemic hypertension, and reduced glomerular filtration. However, we now report that littermates with a homozygous deletion of the gene for the cyclin-dependent kinase inhibitor, p21(WAF1/CIP1), do not develop chronic renal failure after ablation. The markedly different reactions of the p21(+/+) and p21(-/-) animals was not because of differences in glomerular number or degree of renal growth but rather because of the presence or absence of a normal p21 gene. Although the reaction to the stress of renal ablation is both hyperplastic and hypertrophic in the presence of a functional p21 gene, it would appear that the absence of the p21 gene may induce a more hyperplastic reaction because proliferating-cell nuclear antigen expression, a marker of cell-cycle progression, in the renal epithelium of the remnant kidney was more than five times greater in the p21(-/-) mice than in the p21(+/+) animals. Because p21 is a potent inhibitor of the cell cycle, we speculate that p21 regulates the balance between hyperplasia and hypertrophy after renal ablation. We propose that this change in response inhibits the development of chronic renal failure. These studies suggest that controlling p21 function may ameliorate or even prevent progressive end-stage renal disease.

Entamoeba histolytica: a eukaryote with trypanothione metabolism instead of glutathione metabolism

Entamoeba histolytica is a human pathogen that lacks the capacity to synthesize glutathione but can incorporate it, from the growth media or presumably from the human host, to form trypanothione [N(1), N(8)-bis(glutathionyl)-spermidine conjugate]. This novel thiol compound has previously been found in trypanosomatids, as has its precursor glutathionyl-spermidine, which was originally detected in Escherichia coli. Previously we showed the presence of these two thiol compounds in extracts from cultures of Entamoeba histolytica HK9. Here we report that when Entamoeba histolytica HK9 is grown in a culture medium that lacks glutathione (treated with the enzyme gamma-glutamyl transpeptidase), trypanothione is not formed, although the trophozoites can continue dividing for at least 60 h but at 25% lower cell density. The finding of a trypanothione metabolism in Entamoeba histolytica raises many questions: one concerns the possibility of a phylogenetic relationship, in this respect, with trypanosomatids such as Trypanosoma cruzi, T. brucei and Crithidia fasciculata; another concerns its role in cell metabolism; a third concerns it possible use as a target for a rational drug design strategy against this parasite.

Allergy of anaesthetizing agents in Spain

We have investigated the incidence of requests for allergy testing in 5005 patients attending an anaesthetic assessment clinic. Diagnosis of allergy to anaesthetic drugs was established using cutaneous tests. Allergy tests were requested in 151 (3.0%) patients, proving positive in 43 (0.86%). No allergic reactions were observed during subsequent anaesthesia.

[The effect of isoflurane on coronary autoregulation in hypothermia]

OBJECTIVES

To analyze the effect of isoflurane on myocardial metabolism and coronary hemodynamics during the reheating phase after heart surgery.

PATIENTS AND METHODS

Sixteen patients (12 women and 4 men), with cardiac output greater than 0.5 undergoing aortic and/or mitral valve surgery, were studied prospectively. A retrograde thermodilution catheter was placed in the heart and a Swan-Ganz catheter was inserted in the pulmonary artery to determine coronary blood flow and pulmonary wedge pressure, respectively, as well as myocardial and systemic parameters. After surgery, and with hemodynamic variables stable and rectal temperature at 34 +/- 0.5 degrees C, 0.4% isoflurane was administered at the end of expiration. Variables were recorded before administering isoflurane and 20 minutes afterwards.

RESULTS

Isoflurane administration decreased coronary perfusion pressure, coronary vascular resistance, regional myocardial oxygen consumption and myocardial oxygen output. Increases in coronary oxygen saturation and in large coronary vein saturation were also observed. No patient experienced significant changes in ST segment, enzymes or decreased clearance of lactic acid.

CONCLUSIONS

Administering 0.4% isoflurane at the end of expiration effected coronary vasodilation without altering oxygenation or myocardial metabolism. Moreover, no electrocardiographic, enzymatic or metabolic signs of myocardial ischemia were observed.

[Right coronary artery originating from the left sinus of Valsalva. Surgical repair]

Anomalous origin of right coronary artery from left coronary sinus has been considered a minor disease without relevance. Currently it is associated with all symptoms derived from myocardial ischemia because of its lower coronary reserve. We present one patient with anomalous origin of right coronary artery from left coronary sinus surgically treated with saphenous vein aorto-coronary bypass. Doppler velocimetry shows the improvement of myocardial reserve after surgery.

[Isoflurane versus propofol for sedation after heart surgery]

OBJECTIVE

To compare isoflurane and propofol as the principal sedatives in ventilated patients after cardiac surgery with extracorporeal circulation (ECC).

PATIENTS AND METHODS

Forty consecutive, randomized patients undergoing cardiac surgery with ECC were studied prospectively. Patients were assigned to receive either isoflurane or propofol. Variables recorded were level of sedation, adaptation to the respirator and hemodynamic stability.

RESULTS

Each group included 20 patients. The mean dose of isoflurane was 0.39% +/- 0.06% of end-tidal concentration. The mean propofol dose was 2.11 +/- 0.55 mg/kg/h. Statistically significant differences were found for stabilization of sedation time (4 min +/- 1.17 for isoflurane and 11.7 min +/- 4.78 for propofol) and time to endotracheal extubation (56.2 min +/- 20.47 for isoflurane and 72.65 min +/- 30.90 for propofol), number of times dosage had to be changed (2.20 +/- 0.89 with isoflurane and 7.05 +/- 2.58 with propofol) and time of administration had to be interrupted (8.45 min +/- 8.73 with propofol and 0.75 min +/- 1.94 with isoflurane).

CONCLUSIONS

In comparison with propofol, isoflurane offers advantages of rapid stabilization of sedation, ease of use and shorter time to endotracheal extubation.

Comparison of the recovery characteristics of midazolam, alone or antagonised with flumazenil, and thiopental in ASA III-IV patients

Sixty non-premedicated male patients, physically ASA III-IV, 50-80 years of age, undergoing translumbar aorthography, were randomly allocated into three groups. Group A received midazolam (0.13 mg.kg-1), group B received thiopental (4 mg.kg-1), and group C midazolam (0.13 mg.kg-1) combined with flumazenil (6 micrograms.kg-1) at the end of the operation. Three minutes before the anaesthesia began, fentanyl (1.5 micrograms.kg-1) was administered to all the patients. An evaluation was made of the time they took to open their eyes spontaneously, of time-space orientation, comprehension-collaboration, hypnosedation, psychomotor performance and memory. In groups "C" and "B" spontaneous opening of the eyes took place before that of group "A". The recovery of orientation, comprehension and hypnosedation was fastest with thiopental, next with midazolam combined with flumazenil, and later with midazolam. Psychomotor performance in Trieger test was impaired for a shorter period with thiopental than in the other two groups. Recovery in group "C" was incomplete within the time, with the result that resedation was detected in 20% of the subjects.

A quantitative assay that evaluates the capacity of human stromal cells to support granulomonopoiesis in situ

We describe an assay that makes possible the observation of granulomonocytic colonies grown on allogeneic stromal layers and the quantification of the stroma-adherent colony-forming cells (CFC). Stromal layers were generated from Stro-1 positive cells isolated from adherent layers of primary long-term marrow cultures using magnetic beads coated with the Stro-1 antibody. The stromal layers consisted mainly of myofibroblastic cells. Marrow fractions depleted of cells bearing receptors for soybean agglutinin (SBA) and enriched in CD34+ cells were obtained by panning. SBA-, CD34+ marrow cells were seeded onto stromal cells grown in 96-well plates. After four weeks, a mixture of cytokines was added (granulocyte-macrophage colony-stimulating factor [GM-CSF]: 25 U/ml, interleukin [IL]-3: 4 ng/ml, Steel factor: 5 ng/ml and growth factors provided by 3% conditioned medium from the 5637 cell line). Wells with large colonies (containing 10(3) to 10(4) cells) were scored after 14 days. Limiting dilution analysis of data revealed a Poisson distribution of the stroma-adherent CFC. There was an average of one stroma-adherent CFC per 167 CD34+ enriched marrow cells, which gave an estimated frequency of one CFC per 10(5) unfractionated bone marrow cells. Colonies contained cells that gave rise to CFU-GM after replating in agar (5-40 CFU-GM were provided per each stroma-adherent CFC), but not cells with self-renewal ability (as indicated by negative results after replating single colonies onto secondary adherent layers). Colonies usually formed from a cobblestone-area and developed in intimate contact with alpha SM actin positive stromal cells. Some of the stromal cells were located above granulocytic cells, corresponding to the description of "blanket cells." This assay should allow the study of colony-formation on marrow stroma without disrupting the hemopoietic niche.

[Cardiorespiratory evaluation of midazolam and thiopental during their use in patients undergoing translumbar aortography in decubitus prone position and ASA IV]

AIMS

To verify the cardiorespiratory effects of midazolam and thiopental in ASA IV patients undergoing translumbar aortography in the decubitus prone position.

METHODS

A prospective double blind study was carried out on 26 patients (mean age, 65.9 yr) allocated randomly to receive either midazolam (0.13 mg/kg) or thiopental (4 mg/kg) i.v. Without being premedicated all the patients had fentanyl 1.5 micrograms/kg i.v. and were preoxygenated with 50% oxygen before induction of anaesthesia. Blood pressure was measured by oscilometry and blood oxygenation by pulseoxymetry.

RESULTS

No significant differences were found in the hemodynamic values (blood pressure, heart rate, double product) upon comparison of the two groups. Apnea was more frequent in the thiopental group 61.5% (8 out of 13 patients) than in the midazolam group 15.3% (2 out of 13 patients). Hypoxemia appeared only in the former group (61.5% of the cases).

CONCLUSIONS

In patients undergoing translumbar aortography midazolam and thiopental behaved similarly with regard to hemodynamics. Midazolam produced less apnea than thiopental.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) in human long-term bone marrow cultures: endogenous production in the adherent layer and effect of exogenous GM-CSF on granulomonopoiesis

This study was designed to assess the presence of endogenous granulocyte-macrophage colony-stimulating factor (GM-CSF) within adherent layers of human Dexter-type cultures and to investigate the effect on granulomonopoiesis of adding exogenous GM-CSF to the culture medium. The presence of GM-CSF was demonstrated using a bioassay, in which adherent layers from normal bone marrows gave rise to endogenous granulocyte-macrophage colony-forming units (CFU-GM) that were specifically inhibited by increasing amounts of an anti-GM-CSF neutralizing antibody. Using an immunoassay, the estimated amounts of GM-CSF were less than or equal to 40 pg per flask in adherent layers, while remaining undetectable in supernatants. The addition of 10 ng or purified recombinant GM-CSF per milliliter of culture medium increased slightly the CFU-GM output over a 5-week culture period. The addition of 50 ng/mL decreased significantly the CFU-GM output after 5 weeks of culture. This decrease was associated with major modifications of the adherent layer cell composition. Large round or ovoid macrophages were generated at the expense of the interdigitated and elongated stromal cells and the extracellular fibronectin network was no longer observed. These studies suggest that GM-CSF production by accessory cells (stromal cells and/or monocytes) is almost equal to its consumption by hematopoietic cells, a situation similar to that found in long-term cultures of murine marrows. They also show that the maintenance of granulomonopoiesis is decreased by adding more than 10 ng/mL of exogenous GM-CSF to the culture medium, which is related to the induction of adherent macrophages, the disappearance of the major smooth-muscle-like stromal cell component of the adherent layer, and that of the fibronectin extracellular matrix.

[Origins of the rachial administration of cocaine in Spain]

The use of a rachidial pathway for the obtaining of anaesthesia has been the consequence of two events: The discovering of cocaine by Köller and the description made by Corning of the intraspinal passage. If we add to it the attempt to avoid side-effects from ether and chloroform, we find, at the beginning of the century, an enormous increase in the use of the intrarrachidial technique. In the present work, we endeavour to trace the origins of this technique in Spain as well as exposing it and the most outstanding results.

The cytoskeleton of stromal cells from human bone marrow cultures resembles that of cultured smooth muscle cells

The cytoskeleton of stromal cells from the adherent layer of human Dexter-type cultures has been studied. It was found that the stress fibers contained actin specific for smooth muscle, mainly the alpha SM actin isoform. The intermediate filaments consisted of vimentin, and there were no desmin filaments. This pattern was similar to that of cultured vascular smooth muscle cells. The detectability of the alpha SM actin isoform is coincident with the appearance of stromal cells in long-term marrow cultures and may provide a useful marker for stromal cells. The potential in vivo cellular counterpart for stromal cells generated in the Dexter-type culture system is discussed.

In vitro chemosensitivity of leukemic progenitor cells (AML-CFU) to a combination of mafosfamide lysine (ASTA-Z 7654) and etoposide (VP16-213)

The inhibitory effects of mafosfamide lysine, ASTA-Z 7654 (ASTA-Z) and etoposide, (VP16-213) on human leukemic progenitor cells (AML-CFU) were studied using a clonogenic assay. AML-CFU were shown to be less sensitive than human promyelocytic leukemia cells (HL-60) to the toxic effects of these two drugs. The mean log kill obtained for the AML-CFU from 12 patients was only 0.95 and 0.93 for 50 micrograms/ml ASTA-Z and etoposide respectively. For normal progenitor cells (CFU-GM) the maximum log kill increased to 2 log at 50 micrograms/ml ASTA-Z or etoposide and for HL-60 cells more than 4 log kill values were obtained for the same drug concentrations. When the two drugs were used in combination the log kill value increased to 1.75 for AML-CFU. Furthermore, in addition to classic incubation parameters (temperature, cell concentration, red blood cell contamination and time) the treatment efficiency was influenced by the incubation sequence of the two drugs. When ASTA-Z and etoposide were incubated together (Z/VP) or etoposide prior to ASTA-Z (VP + Z) log kill values for drug concentrations of 20 and 50 micrograms/ml were 0.72 and 1.41 respectively. However, when cells were incubated with ASTA-Z prior to etoposide (Z + VP) values of 1.1 and 1.75 were obtained for drug concentrations of 20 and 50 micrograms/ml respectively (p less than or equal to 0.05 between Z + VP and the two other sequences).(ABSTRACT TRUNCATED AT 250 WORDS)

Preclinical studies of the combination of mafosfamide (Asta-Z 7654) and etoposide (VP-16-213) for purging leukemic autologous marrow

In the present study we evaluated the effect of etoposide (VP-16-213) compared to mafosfamide-cyclohexylamine (Asta-Z 7654) on normal granulocyte-macrophage colony-forming unit (GM-CFU) growth, T-cell response to mitogens, and a clonogenic promyelocytic cell line (HL-60). The incubation time (30 min vs 60 min) appeared to be a fundamental parameter. The GM-CFU recovery was 14.4% +/- 7.3% and 1.4% +/- 2.3%, respectively, at 50 micrograms/ml Asta-Z 7654, and 17.6% +/- 8.6% and 3.00% +/- 2.4%, respectively, at 50 micrograms/ml VP-16. ASTA-Z at 50 micrograms/ml was effective in inhibiting the T-cell response to phytohemagglutinin (98.7% +/- 1.2%), whereas VP-16 was not (2.3% +/- 1.7%). With the combined chemical agents ranging from 10 to 20 micrograms/ml for each drug, we obtained a better GM-CFU recovery (five to ten times) using a middle term liquid culture (21-day incubation) than with the standard colony assay (plated immediately after treatment). When using HL-60 cells as the target, the antileukemic activity of VP-16 was lower than of Asta-Z 7654. Both compounds, at 20 micrograms/ml, resulted in 3.3- and 2.3-log cell killing, respectively. On the other hand, lower doses of Asta-Z 7654 combined with VP-16 (ranging from 10 to 15 micrograms/ml each) induced greater than 4-log cell killing after 60 min incubation time. These data suggest that VP-16 could be combined with Asta-Z provided that the dose is reduced for both drugs (less than 20 micrograms/ml).

[Culture of leukemic progenitor cells in acute non-T lymphoid leukemia]

A preliminary study of the culture of leukemic progenitor cells (CFU-L) from acute non-T lymphoblastic leukemia was undertaken for 25 patients (19 were considered in complete remission and 6 in the acute phase of the disease). Two culture systems were tested; a double layer agar-liquid phase and a single layer of methylcellulose. The major problem was the characterization of the colonies: immunological labelling coupled with cytofluorometry, as well as cytomorphology, cytogenetic and more recently molecular biology may allow the characterization of the CFU-L. The culture of CFU-L appears to be an efficient method for detecting residual leukemic cells which can be used to evaluate the quality of both the remission obtained and that of autologous bone marrow after purging.

Autologous bone marrow transplantation for acute leukemia using transplant chemopurified with metabolite of oxazaphosphorines (ASTA Z 7557, INN mafosfamide). First clinical results

The contamination of autologous marrow with clonogenic tumor cells has been the main argument against ABMT in acute leukemia. In a preclinical study we evaluated an active cyclophosphamide derivative named "ASTA Z 7557". We observed that the toxic effect of this drug on CFU-GM growth was dependent on nucleated cell concentration as well as on red blood cell contamination. The potency of the drug was in close relationship with the incubation temperature. The growth of leukemic CFU was inhibited with an ASTA Z dose higher than 30 micrograms/ml. In our system, beyond 40 micrograms/ml more than 95% of committed stem cells are destroyed. Fifteen patients had autotransplant because of AML for 10 patients and because of ALL for 5 patients (4 patients were grafted in relapse and 11 patients in remission). We demonstrated that the marrow take was possible although the inoculum is CFU-GM depleted. Five of the 10 AML patients are alive and remain disease-free at 45+, 65+, 190+, 345+ and 570+ days from ABMT without any maintenance treatment. Four of the 5 ALL patients are alive, three of them in complete remission (40+, 110+, 250+ days). The number of patients reported in this clinical study was relatively small and more cases should be evaluated to be conclusive. Nevertheless the feasibility of chemopurified ABMT was demonstrated.