Membrane Condensation and Curvature Induced by SARS-CoV-2 Envelope Protein

The envelope (E) protein of SARS-CoV-2 participates in virion encapsulation and budding at the membrane of the endoplasmic reticulum Golgi intermediate compartment (ERGIC). The positively curved membrane topology required to fit an 80 nm viral particle is energetically unfavorable; therefore, viral proteins must facilitate ERGIC membrane curvature alteration. To study the possible role of the E protein in this mechanism, we examined the structural modification of the host lipid membrane by the SARS-CoV-2 E protein using synchrotron-based X-ray methods. Our reflectometry results on solid-supported planar bilayers show that E protein markedly condenses the surrounding lipid bilayer. For vesicles, this condensation effect differs between the two leaflets such that the membrane becomes asymmetric and increases its curvature. The formation of such a curved and condensed membrane is consistent with the requirements to stably encapsulate a viral core and supports a role for E protein in budding during SARS-CoV-2 virion assembly.

The current state of the art in internal additive materials and quantum dots for improving efficiency and stability against humidity in perovskite solar cells

The remarkable optoelectronic capabilities of perovskite structures enable the achievement of astonishingly high-power conversion efficiencies on the laboratory scale. However, a critical bottleneck of perovskite solar cells is their sensitivity to the surrounding humid environment affecting drastically their long-term stability. Internal additive materials together with surface passivation, polymer-mixed perovskite, and quantum dots, have been investigated as possible strategies to enhance device stability even in unfavorable conditions. Quantum dots (QDs) in perovskite solar cells enable power conversion efficiencies to approach 20%, making such solar cells competitive to silicon-based ones. This mini-review summarized the role of such QDs in the perovskite layer, hole-transporting layer (HTL), and electron-transporting layer (ETL), demonstrating the continuous improvement of device efficiencies.

Supported polymer/lipid hybrid bilayers formation resembles a lipid-like dynamic by reducing the molecular weight of the polymer

Amphiphilic block copolymers form self-assembled bilayers even in combination with phospholipids. They represent an attractive alternative to native lipid-based membrane systems for supported bilayer formation with applications in biomedical research, sensoring and drug delivery. Their enhanced stability and excellent mechanical properties are linked to their higher molecular weight which generates thicker bilayers. Hypothesis: It is hypothesized that reducing the molecular weight of the polymer facilitates the formation of a thinner, more homogeneous polymer/lipid hybrid bilayer which would benefit the formation of supported bilayers on silicon oxide. Experiment: We investigated hybrid bilayers composed of mixtures of 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine and increasing amounts of a low molecular weight polybutadiene-b-polyethylene oxide copolymer (1050 g/mol). By assessing the bilayer thickness and the molecular packing behavior we sought to demonstrate how reducing the polymer molecular weight increases the tendency to form supported hybrid bilayers in a lipid-like manner. Findings: The formation of a supported hybrid bilayers occurs at polymer contents <70 mol% in a lipid-like fashion and is proportional to the cohesive forces between the bilayer components and inversely related to the bilayer hydrophobic core thickness and the extended brush regime of the PEGylated polymeric headgroup.

Synchrotron Photothermal Infrared Nanospectroscopy of Drug-Induced Phospholipidosis in Macrophages

Synchrotron resonance-enhanced infrared atomic force microscopy (RE-AFM-IR) is a near-field photothermal vibrational nanoprobe developed at Diamond Light Source (DLS), capable of measuring mid-infrared absorption spectra with spatial resolution around 100 nm. The present study reports a first application of synchrotron RE-AFM-IR to interrogate biological soft matter at the subcellular level, in this case, on a cellular model of drug-induced phospholipidosis (DIPL). J774A-1 macrophages were exposed to amiodarone (10 μM) or medium for 24 h and chemically fixed. AFM topography maps revealed amiodarone-treated cells with enlarged cytoplasm and very thin regions corresponding to collapsed vesicles. IR maps of the whole cell were analyzed by exploiting the RE-AFM-IR overall signal, i.e., the integrated RE-AFM-IR signal amplitude versus AFM-derived cell thickness, also on lateral resolution around 100 nm. Results show that vibrational band assignment was possible, and all characteristic peaks for lipids, proteins, and DNA/RNA were identified. Both peak ratio and unsupervised chemometric analysis of RE-AFM-IR nanospectra generated from the nuclear and perinuclear regions of untreated and amiodarone-treated cells showed that the perinuclear region (i.e., cytoplasm) of amiodarone-treated cells had significantly elevated band intensities in the regions corresponding to phosphate and carbonyl groups, indicating detection of phospholipid-rich inclusion bodies typical for cells with DIPL. The results of this study are of importance to demonstrate not only the applicability of Synchrotron RE-AFM-IR to soft biological matters with subcellular spatial resolution but also that the spectral information gathered from an individual submicron sample volume enables chemometric identification of treatment and biochemical differences between mammalian cells.

The Effect of Nanosecond, High-Voltage Electric Pulses on the Shape and Permeability of Polymersome GUVs

Polymersomes, vesicles composed of block copolymers, are promising candidates as membrane alternatives and functional containers, e.g., as potential carriers for functional molecules because of their stability and tunable membrane properties. In the scope of possible use for membrane protein delivery to cells by electrofusion, we investigated the cytotoxicity of such polymersomes as well as the effects of nanosecond electric pulses with variable repetition rate on the shape and permeability of polymersomes in buffers with different conductivities. The polymersomes did not show cytotoxic effects to CHO and B16-F1 cells in vitro in concentrations up to 250 µg/mL (for 48 h) or 1.35 mg/mL (for 60 min), which renders them suitable for interacting with living cells. We observed a significant effect of the pulse repetition rate on electrodeformation of the polymersomes. The electrodeformation was most pronounced in low conductivity buffer, which is favorable for performing electrofusion with cells. However, despite more pronounced deformation at higher pulse repetition rate, the electroporation performance of polymersomes was unaffected and remained in similar ranges both at 10 Hz and 10 kHz. This phenomenon is possibly due to the higher stability and rigidity of polymer vesicles, compared to liposomes, and can serve as an advantage (or disadvantage) depending on the aim in employing polymersomes such as stable membrane alternative architectures or drug vehicles.

Clinical and microbiological outcome in septic patients with extremely low 25-hydroxyvitamin D levels at initiation of critical care

A relationship between vitamin D status and mortality in patients in intensive care units (ICU) has been documented. The present study aims to describe the clinical profile and sepsis-related outcome of critically ill septic patients with extremely low (<7 ng/mL) vitamin D levels at ICU admission. We conducted an observational study in the ICU of a teaching hospital including all patients admitted with severe sepsis/septic shock and undergoing 25-hydroxyvitamin D (25(OH)D) testing within the first 24 hours from admission. We studied 107 patients over 12 months. At ICU admission vitamin D deficiency (≤20 ng/mL) was observed in 93.5% of the patients: 57 (53.3%) showed levels <7 ng/mL. As primary outcome, sepsis-related mortality rate was higher in patients with vitamin D levels <7 ng/mL (50.9% versus 26%). Multivariate regression analysis showed that vitamin D concentration <7 ng/mL on ICU admission (p 0.01) and higher mean SAPS II (p <0.01) score were independent predictors of sepsis-related mortality. Patients with very low vitamin D levels suffered higher rate of microbiologically confirmed infections but a lower percentage of microbiological eradication with respect to patients whose values were >7 ng/mL (80.7% versus 58%, p 0.02; 35.3% versus 68%; p 0.03, respectively). Post hoc analysis showed that, in the extremely low vitamin D group, the 52 patients with pneumonia showed a longer duration of mechanical ventilation (9 days (3.75-12.5 days) versus 4 days (2-9 days), p 0.04) and the 66 with septic shock needed vasopressor support for a longer period of time (7 days (4-10 days) versus 4 days (2-7.25 days), p 0.02). Our results suggest that in critical septic patients extremely low vitamin D levels on admission may be a major determinant of clinical outcome. Benefits of vitamin D replacement therapy in this population should be elucidated.

Characterization of the aggregates formed by various bacterial lipopolysaccharides in solution and upon interaction with antimicrobial peptides

The biophysical analysis of the aggregates formed by different chemotypes of bacterial lipopolysaccharides (LPS) before and after challenge by two different antiendotoxic antimicrobial peptides (LL37 and bovine lactoferricin) was performed in order to determine their effect on the morphology of LPS aggregates. Small-angle neutron scattering (SANS) and cryogenic transmission electron microscopy (cryoTEM) were used to examine the structures formed by both smooth and rough LPS chemotypes and the effect of the peptides, by visualization of the aggregates and analysis of the scattering data by means of both mathematical approximations and defined models. The data showed that the structure of LPS determines the morphology of the aggregates and influences the binding activity of both peptides. The morphologies of the worm-like micellar aggregates formed by the smooth LPS were relatively unaltered by the presence of the peptides due to their pre-existing high degree of positive curvature being little affected by their association with either peptide. On the other hand, the aggregates formed by the rough LPS chemotypes showed marked morphological changes from lamellar structures to ordered micellar networks, induced by the increase in positive curvature engendered upon association with the peptides. The combined use of cryoTEM and SANS proved to be a very useful tool for studying the aggregation properties of LPS in solution at biologically relevant concentrations.

Phylogeography and evolutionary history of rodent-borne hantaviruses

Hantavirus (Family Bunyaviridae) are mostly associated to rodents and transmitted to man by inhalation of aerosolized infected excreta of these animals. The human infection by hantaviruses can lead to severe diseases such as hemorrhagic fever with renal syndrome (HFRS) in Asia and Europe, and pulmonary syndrome (HPS) in the Americas. To determine the origin, spreading and evolutionary dynamics of rodent-borne hantaviruses, 190 sequences of nucleoprotein (N) of hantaviruses identified in 30 countries, from 1985 to 2010, were retrieved from the GenBank and analyzed using the BEAST program. Our evolutionary analysis indicates that current genetic diversity of N gene of rodent-borne hantaviruses probably was originated around 2000 years ago. Hantavirus harbored by Murinae and Arvicolinae subfamilies, probably, were originated in Asia 500-700 years ago and later spread toward Siberia, Europe, Africa and North America. Hantavirus carried by Neotominae subfamily, probably, emerged 500-600 years ago in Central America and spread toward North America. Finally, hantaviruses associated to Sigmodontinae occurred in Brazil 400 years ago and were, probably, originated from Neotominae-associated virus from northern South America. These data offer subsidies to understand the time-scale and worldwide dissemination dynamics of rodent-borne hantaviruses.

New membranes for extracorporeal blood purification in septic conditions

Severe sepsis and septic shock are still the leading cause of mortality and morbidity in the intensive care unit. The inflammatory response to infection is associated with an impressive, systemic release of pro- and anti-inflammatory mediators, which results in generalized endothelial damage, multiple organ failure and altered cellular immunological responsiveness. Over the last years, the substantial advances in the understanding of sepsis have led to the development of a large number of new approaches and technologies in the management of septic patients. Extracorporeal blood purification techniques using various membrane materials have been proposed to modulate multiple inflammatory mediators, and seem to be a potential adjuvant in the treatment of sepsis. However, the use of extracorporeal blood purification techniques during sepsis still remains controversial, thus precluding any definitive recommendations on the benefit of these methods. More data are needed to better recognize septic patients who are most likely to benefit from blood purification treatments, and clarify the optimal timing, duration, and number of applications of these techniques in the daily clinical practice.

Expression of vitellogenin receptor gene in the ovary of wild and captive Atlantic bluefin tuna (Thunnus thynnus)

The cDNA sequences of vitellogenin receptor proteins (VgR(+) and VgR(-)), containing or lacking the O-linked sugar domain, were determined in Atlantic bluefin tuna (Thunnus thynnus L.). VgR(-) gene expression in the ovary was compared in captive-reared and wild Atlantic bluefin tuna during the reproductive cycle. Gonad samples from adult fish were sampled from 2008 to 2010 from stocks reared in captivity at different commercial fattening operations in the Mediterranean Sea and from wild individuals caught either by traditional tuna traps during their migration towards the spawning grounds in the Mediterranean Sea or by the long-line artisanal fishery. In addition, juvenile male and female Atlantic bluefin tuna were sampled from a farming facility, to obtain baseline information and pre-adulthood amounts of VgR(-). The total length of VgR(+) cDNA was 4006 nucleotides (nt) and that of VgR(-) was 3946 nt. Relative amounts of VgR(-) were greater in juvenile females and in those adults having only previtellogenic oocytes (119 ± 55 and 146 ± 26 folds more than juvenile males, respectively). Amounts of VgR(-) were less in individuals with yolked oocytes (ripening stage, May-June) and increased after spawning in July (92 ± 20 and 113 ± 13 folds more than juvenile males in ripening and post-spawning fish, respectively). These data suggest that regulation of VgR(-) is not under oestrogen control. During the ripening period, greater VgR(-) gene expression was observed in wild fish than in fish reared in captivity, possibly because of (a) differences in water temperature exposure and/or energy storage, and/or (b) an inadequate diet in reared Atlantic bluefin tuna.

Evidence that severe acute stress and starvation induce rapid atresia of ovarian vitellogenic follicles in Atlantic bluefin tuna, Thunnus thynnus (L.) (Osteichthyes: Scombridae)

The effects of different stressors on the atretic degeneration of ovarian vitellogenic follicles, as well as on the ovarian mass, were examined in female Atlantic bluefin tuna, Thunnus thynnus (L.), from the Mediterranean Sea. The stressors taken into consideration were short-term starvation (up to 14 days), long-term cage rearing (1 year) and crowding-induced severe panic frenzy. Wild-caught individuals were used as a control group. Fish subjected to either severe panic frenzy or starvation exhibited a decrease in gonad mass and had significantly higher intensity of α atresia in the vitellogenic follicles (means: 78% and 58%, respectively; range: 36-100%) than either wild or long-term caged individuals (means: 32% and 30%, respectively; range: 19-44%). The extensive atresia in fish stressed by severe panic frenzy was observed as early as 24 h after the stressing event. The present study represents the first evidence of the extreme susceptibility of Atlantic bluefin tuna to severe acute stress during vitellogenesis; it also shows that starvation is associated with progressive reabsorption of vitellogenic oocytes.

Steroids in severe pneumonia: a literature review

Despite more than sixty years of scientific medical research, severe pneumonia, either community-acquired or nosocomial, remains a leading cause of death regardless of the patients' immunity state. The clinical introduction of new and more potent antibiotic molecules and the continuous development of efficient respiratory assistance devices may not be able to radically improve the clinical outcome of pneumonia. Adjunctive therapies based on the physiopathological mechanisms of lung damage in severe pneumonia have been strongly advocated, and corticosteroids, which present many properties that theoretically interfere with these pathways, have been widely used, with conflicting results. The aim of this review is to examine existing literature data on steroid use in severe pneumonia. Molecular, endocrinological and clinical studies will be described to help physicians to clarify the reasons for the historical debate about steroid use as an adjunctive treatment in severe pneumonia. There is growing evidence that, during lung infection, an excessive inflammatory response can have deleterious effects and contribute to tissue damage mechanisms. Because of their immunomodulatory properties, glucocorticoids have been suggested as a useful tool for regulating the complex balance of cytokine networks, and they are commonly used as an adjunctive therapy during serious infections. In severe pneumonia, preclinical data, including cytokine level detection and animal studies, have shown encouraging results, although the clinical data is controversial. Moreover, large randomized controlled trials have not been conducted to determine steroid side effects and the risk of immunosuppression-induced superinfections. The benefits of steroid use in patients with severe pneumonia have not been proven by current literature, but ongoing investigations of anti-inflammatory molecules probably represent the key point of severe infection management in the near future.

Chest pain caused by tracheostomy tube malposition: the importance of choosing the right tube

We describe a case of chest pain caused by tracheostomy tube malposition in a 65-year old woman with chronic respiratory failure due to chronic obstructive pulmonary disease. This report highlights the importance of the correct choice of tracheostomy tube devices for mechanically ventilated and/or spontaneously breathing patients.

Successful treatment of multidrug-resistant Acinetobacter baumannii ventriculitis with intrathecal and intravenous colistin

Acinetobacter baumannii (AB) nosocomial infections, especially those due to multi-drug resistant (MDR) strains, are increasingly detected. We report a case of a 42-year-old male patient affected by low-grade ependymoma who developed AB-MDR post-neurosurgical ventriculitis. Initially, because of in vitro susceptibility, we used a combination of intravenous colistin and tigecycline. This treatment resulted in the improvement of the patient's initial condition. However, soon after, the infection relapsed; tigecycline was stopped and treatment with intrathecal colistin was initiated. Cure was achieved by continuing this treatment for approximately three weeks, without adverse effects.

The role of thyroid dysfunction in the critically ill: a review of the literature

During critical illness, patients with no known history of thyroid disorders may experience multiple alterations in their serum thyroid hormone levels. Such alterations have been termed sick euthyroid syndrome or, more recently, non-thyroidal illness syndrome (NTIS). The laboratory parameters of NTIS usually include low serum levels of triiodothyronine (T3), normal or low serum levels of thyroxine (T4) and normal or low serum levels of thyroid-stimulating hormone (TSH). The magnitude of the alteration in thyroid function correlates with the severity of the illness and its outcomes in critically ill patients with NTIS. The pathogenetic mechanisms involved in NTIS include a decreased conversion of T4 to T3 in extrathyroidal tissues and alterations in thyroid hormones' binding to serum proteins. In cases of protracted critical illness, a decrease in the pulsatile frequency of TSH secretion, resulting from reduced thyrotropin-re leasing hormone (TRH) release by the hypothalamus, may also occur. Several medications or clinical conditions that are commonly present in critically ill patients may be responsible for lowering serum concentrations of thyroid hormone. Among those who study the condition, the question of whether NTIS is a protective adaptation of the organism to illness or a maladaptive response to a stressful insult remains unanswered. In either case, thyroid hormone abnormalities are likely to play a role in the critically ill patient.However, there is currently no convincing evidence to suggest that restoring physiological thyroid hormone concentrations in unselected patients with NTIS would be beneficial.

Diurnal and nocturnal shifts do not influence non-invasive ventilation outcome

AIM

The aim of this study was to assess if diurnal or nocturnal shifts were independent risk factors for non-invasive ventilation (NIV) failure.

METHODS

This was an observational study carried out on 18 patients of the general Intensive Care Unit in Rome. A total number of 189 consecutive patients needing mechanical ventilation for respiratory failure were prospectively enrolled: 82 were treated with NIV as a first line intervention. Of the 107 patients who were initially intubated, 59 patients were extubated; once extubation failed they were treated with NIV. NIV failure was assessed during both the day (between 7 am and 10 pm) and night shifts (between 10 pm and 7 am).

RESULTS

Of the 141 total patients who received NIV, 51 experienced failure during the day shifts and 18 during the night shifts. No difference in the median day and night shift TISS-28 values were observed in any patients who failed NIV during both day and night shifts. Causes of NIV failure were similar during both diurnal and nocturnal shifts. The inability to correct gas exchanges was the main reason for failure.

CONCLUSION

In a center with NIV expertise, notwithstanding nurse understaffing, diurnal and nocturnal shifts did not affect the rate of NIV failure.

Treating nonthyroidal illness syndrome in the critically ill patient: still a matter of controversy

The nonthyroidal illness syndrome (NTIS) is a clinical condition of abnormal thyroid function tests observed in patients with acute or chronic systemic illnesses. The laboratory parameters of NTIS usually include low serum levels of triiodothyronine, with normal or low levels of thyroxine and normal or low levels of thyroid-stimulating hormone. It is still a matter of controversy whether the NTIS represents a protective adaptation of the organism to a stressful event or a maladaptive response to illness that needs correction. Multiple studies have investigated the effect of thyroid hormone replacement therapy in certain clinical situations, such as caloric restriction, cardiac disease, acute renal failure, brain-dead potential donors, and burn patients. Treating patients with NTIS seems not to be harmful, but there is no persuasive evidence that it is beneficial. The administration of hypothalamic releasing factors in patients with NTIS appears to be safe and effective in improving metabolism and restoring the anterior pituitary pulsatile secretion in the chronic phase of critical illness. However, also this promising strategy needs to be explored further. Anyhow, an extremely prudent approach is needed if treatment is given. Much of the data appearing in the literature on the treatment of NTIS encourage further randomized controlled trials on large number of patients. At present, however, we believe that there is no indication for treating thyroid hormone abnormalities in critically ill patients until convincing proof of efficacy and safety is provided.

Declines in HIV prevalence can be associated with changing sexual behaviour in Uganda, urban Kenya, Zimbabwe, and urban Haiti

OBJECTIVE

To determine whether observed changes in HIV prevalence in countries with generalised HIV epidemics are associated with changes in sexual risk behaviour.

METHODS

A mathematical model was developed to explore the relation between prevalence recorded at antenatal clinics (ANCs) and the pattern of incidence of infection throughout the population. To create a null model a range of assumptions about sexual behaviour, natural history of infection, and sampling biases in ANC populations were explored to determine which factors maximised declines in prevalence in the absence of behaviour change. Modelled prevalence, where possible based on locally collected behavioural data, was compared with the observed prevalence data in urban Haiti, urban Kenya, urban Cote d'Ivoire, Malawi, Zimbabwe, Rwanda, Uganda, and urban Ethiopia.

RESULTS

Recent downturns in prevalence observed in urban Kenya, Zimbabwe, and urban Haiti, like Uganda before them, could only be replicated in the model through reductions in risk associated with changes in behaviour. In contrast, prevalence trends in urban Cote d'Ivoire, Malawi, urban Ethiopia, and Rwanda show no signs of changed sexual behaviour.

CONCLUSIONS

Changes in patterns of HIV prevalence in urban Kenya, Zimbabwe, and urban Haiti are quite recent and caution is required because of doubts over the accuracy and representativeness of these estimates. Nonetheless, the observed changes are consistent with behaviour change and not the natural course of the HIV epidemic.

Plasma RNA viral load is not associated with intrapatient quasispecies heterogeneity in HIV-1 infection

The human immunodeficiency virus type 1 (HIV-1) viral set point has been associated with the rate of, disease progression and with the level of HIV-specific immune response. The analysis of the possible association between viral set point and quasispecies heterogeneity has important consequences in the understanding of HIV-1 in vivo evolution. In this study, we analyzed the association between intrapatient viral diversity and RNA viral load in 16 antiretroviral therapy-naive HIV-1-infected patients at a single time point, during the disease free period. Patients were separated into low and high viral load groups according to plasma RNA values. HIV-1 quasispecies complexity was assessed in the C2-V5 env region. The average intrapatient quasispecies heterogeneity in both groups was not significantly different (t-test, P > 0.05). However, while within the low viral load group both synonymous and non-synonymous mutations contribute to the variation observed, in the heterogeneity observed in the high viral load group there was an increase in the contribution of the non-synonymous mutations. Thus, this study show that although intrapatient quasispecies heterogeneity is not associated with viral set point in HIV-1 infection, some differences exist between the two groups in the pattern of mutation accumulation.

Evaluation of the utility of serological tests in the diagnosis of candidemia

BACKGROUND

It has been observed that the incidence and prevalence of candida infections in critically ill non-immunocompromised patients has increased. This study aims to evaluate the utility of the use of serological tests (double immunodiffusion and Cand-Tec Test) for the determination of candidemia.

METHODS

A retrospective evaluation is made of 214 patients admitted to the Intensive Care Unit (ICU) of the Agostino Gemelli University Polyclinic during a period of 42 months. The double immunodiffusion technique was utilized for the determination of Candida antibodies. The Cand-Tec latex agglutination test was performed to evaluate the presence of Candida antigen. Four hundred and fifty-five antigen and antibody tests were performed.

RESULTS

Thirty-six patients (16.8%) developed an invasive candidiasis. The sensitivity and specificity of antibody detection tests was 29 and 67 respectively; the positive predictive value was 15 and the negative predictive value was 82. The sensitivity and specificity of the antigen detection test ranged between 82 and 3 and between 8 and 98 respectively according to different cut-off titre; the positive predictive value was low (13-17%) and the negative predictive value decreased from 70 to 29.

CONCLUSIONS

The utility of the use of serological tests in the diagnosis of candidemia is extremely limited. The gold standard for the determination of Candida sepsis remains the demonstration of candida in blood or in tissues.

[Incidence of thrombi in implantation of pulmonary artery catheters]

AIM

To evaluate the occurrence of thrombi in introducers employed for pulmonary artery catheterization.

DESIGN

prospective study.

SETTING

cardiac Surgery ICU in a University Hospital.

PATIENTS

three groups of 20 subjects each: in group A, undergoing mitral or aortic valve replacement, a pulmonary artery catheter was placed through an introducer; in group B, undergoing myocardial revascularization, a pulmonary artery catheter was placed through an introducer; in group C, undergoing myocardial revascularization, only an introducer was placed.

METHODS

The introducers were removed between the 2nd and the 8th postoperative day and the external surface and the lumen were inspected for thrombi.

RESULTS

Endoluminal thrombi were observed in 40% of the introducers, but the patency of the lumen was always maintained. The incidence of thrombi was significantly higher in group A (23% in aggregate) than in group B (10%; p < 0.05) and in group C (6%; p < 0.05); by contrast no significant difference was observed between groups B and C.

CONCLUSIONS

Endoluminal thrombi are very frequent in introducers employed for pulmonary artery catheterization but they are hardly suspected since the patency of the lumen is usually preserved. The lower incidence of thrombosis in groups B and C could hypothetically originate from antiaggregant therapy started within 24 hours from the end of surgery for myocardial revascularization.

Computerized pharmacy services in a large community hospital

A computerized pharmacy system dealing with drug distribution, clinical services and administrative services is described. Present systems, implemented for 50% of the institution's beds, are discussed fully. Future applications of the system are outlined.