Severity of illness by pregnancy status among laboratory-confirmed SARS-CoV-2 infections occurring in reproductive-aged women in Colombia

BACKGROUND

Multiple studies have described increased risk of severe coronavirus disease (COVID-19) among pregnant women compared to nonpregnant women. The risk in middle-income countries where the distributions of age groups and preexisting conditions may differ is less known.

OBJECTIVES

To determine whether pregnant women with SARS-CoV-2 infection are at increased risk for severe COVID-19 compared to nonpregnant women in Colombia.

METHODS

We analysed national surveillance data from Colombia, of women aged 15-44 years with laboratory-confirmed infection with SARS-CoV-2 by molecular or antigen testing, from 6 March 2020 to 12 December 2020. An enhanced follow-up of pregnant women with COVID-19 was established to monitor pregnancy and birth outcomes.

RESULTS

Of 371,363 women aged 15-44 years with laboratory-confirmed SARS-CoV-2 infection, 1.5% (n = 5614) were reported as pregnant; among those, 2610 (46.5%) were considered a complete pregnancy for reporting purposes at the time of analysis. Hospitalisation (23.9%) and death (1.3%) occurred more frequently among pregnant symptomatic women compared to nonpregnant symptomatic women (2.9% and 0.3%, respectively). Compared to nonpregnant symptomatic women, pregnant symptomatic women were at increased risk of hospitalisation (adjusted risk ratio [RR] 2.19, 95% confidence interval [CI] 2.07, 2.32) and death (RR 1.82, 95% CI 1.60, 2.07), after adjusting for age, type of health insurance and presence of certain underlying medical conditions. Among complete pregnancies, 55 (2.1%) were pregnancy losses, 72 (2.8%) resulted in term low birthweight infants and 375 (14.4%) were preterm deliveries.

CONCLUSIONS

Although pregnant women were infrequently reported with laboratory-confirmed SARS-CoV-2 infection, pregnant symptomatic women with COVID-19 were at increased risk for hospitalisation and death compared to nonpregnant symptomatic women. Almost all infections we reported on were third-trimester infections; ongoing follow-up is needed to determine pregnancy outcomes among women infected earlier in pregnancy. Healthcare providers should counsel pregnant women about preventive measures to protect from SARS-CoV-2 infection and when to seek care.

Molecular dynamics study of nanoconfined TIP4P/2005 water: how confinement and temperature affect diffusion and viscosity

In the past few decades great effort has been devoted to the study of water confined in hydrophobic geometries at the nanoscale (tubes and slit pores) due to the multiple technological applications of such systems, ranging from drug delivery to water desalination devices. To our knowledge, neither numerical/theoretical nor experimental approaches have so far reached a consensual understanding of structural and transport properties of water under these conditions. In this work, we present molecular dynamics simulations of TIP4P/2005 water under different nanoconfinements (slit pores or nanotubes, with two degrees of hydrophobicity) within a wide temperature range. It has been found that water is more structured near the less hydrophobic walls, independently of the confining geometries. Meanwhile, we observe an enhanced diffusion coefficient of water in both hydrophobic nanotubes. Finally, we propose a confined Stokes-Einstein relation to obtain the viscosity from diffusivity, whose result strongly differs from the Green-Kubo expression that has been used in previous works. While viscosity computed with the Green-Kubo formula (applied for anisotropic and confined systems) strongly differs from that of the bulk, viscosity computed with the confined Stokes-Einstein relation is not so much affected by the confinement, independently of its geometry. We discuss the shortcomings of both approaches, which could explain this discrepancy.

PLA2G6 mutations associated with a continuous clinical spectrum from neuroaxonal dystrophy to hereditary spastic paraplegia

PLA2G6-associated neurodegeneration (PLAN) and hereditary spastic paraplegia (HSP) are 2 groups of heterogeneous neurodegenerative diseases. In this study, we report PLA2G6 gene mutations in 3 families from Turkey, Morocco, and Romania. Two affected Turkish siblings presenting HSP adds the disease to PLAN phenotypes. They were homozygous for the PLA2G6 missense c.2239C>T, p.Arg747Trp variant and the ages of onset were 9 and 21. Parkinsonism, dystonia or cognitive decline were not the clinical elements in these patients contrary to the cases that has been previously reported with the same variant, however, iron accumulation was evident in their cranial magnetic resonance imaging. The Moroccan patient was homozygous for a novel missense c.1786C>T, p.Leu596Phe variant and the Romanian patient had 2 novel mutations; c.1898C>T, p.Ala633Val and c.1765_1768del, p.Ser589ThrfsTer76. Both of these patients conformed better to childhood onset PLAN with the age of onset at 4 and 7 years, respectively. Interestingly, all identified mutations were affecting the highly conserved patatin-like phospholipase domain of the PLA2G6 protein.

Effect of passive heat stress on arterial stiffness in smokers versus non-smokers

In non-smokers, passive heat stress increases shear stress and vasodilation, decreasing arterial stiffness. Smokers, who reportedly have arterial dysfunction, may have similar improvements in arterial stiffness with passive heat stress. Therefore, we examined the effects of an acute bout of whole-body passive heat stress on arterial stiffness in smokers vs. non-smokers. Thirteen smokers (8.8 ± 5.5 [median = 6] cigarettes per day for > 4 years) and 13 non-smokers matched for age, mass, height, and exercise habits (27 ± 8 years; 78.8 ± 15.4 kg; 177.6 ± 6.7 cm) were passively heated to 1.5 °C core temperature (T C) increase. At baseline and each 0.5 °C T C increase, peripheral (pPWV) and central pulse wave velocity (cPWV) were measured via Doppler ultrasound. No differences existed between smokers and non-smokers for any variables (all p >  .05), except cPWV slightly increased from baseline (526.7 ± 81.7 cm · s(-1)) to 1.5 °C ΔT C (579.7 ± 69.8 cm · s(-1); p < 0.005), suggesting heat stress acutely increased central arterial stiffness. pPWV did not change with heating (grand mean: baseline = 691.9 ± 92.9 cm · s(-1); 1.5 °C ΔT C = 691.9 ± 79.5 cm · s(-1); p > 0.05). Changes in cPWV and pPWV during heating correlated (p < 0.05) with baseline PWV in smokers (cPWV: r = -0.59; pPWV: r = -0.62) and non-smokers (cPWV: r = -0.45; pPWV: r = -0.77). Independent of smoking status, baseline stiffness appears to mediate the magnitude of heating-induced changes in arterial stiffness.

Use of nested flow models and interpolation techniques for science-based management of the Sheyenne National Grassland, North Dakota, USA

Noxious weeds threaten the Sheyenne National Grassland (SNG) ecosystem and therefore herbicides have been used for control. To protect groundwater quality, the herbicide application is restricted to areas where the water table is less than 10 feet (3.05 m) below the ground surface in highly permeable soils, or less than 6 feet (1.83 m) below the ground surface in low permeable soils. A local MODFLOW model was extracted from a regional GFLOW analytic element model and used to develop depth-to-groundwater maps in the SNG that are representative for the particular time frame of herbicide applications. These maps are based on a modeled groundwater table and a digital elevation model (DEM). The accuracy of these depth-to-groundwater maps is enhanced by an artificial neural networks (ANNs) interpolation scheme that reduces residuals at 48 monitoring wells. The combination of groundwater modeling and ANN improved depth-to-groundwater maps, which in turn provided more informed decisions about where herbicides can or cannot be safely applied.

In-plane pyridinium cation reorientation in bis-thiourea chloride, bromide and iodide: quasielastic neutron scattering combined with molecular dynamics simulations

We have studied the dynamics of bis-thiourea pyridinium chloride and bromide by means of quasielastic neutron scattering (QENS). The QENS data allow describing the geometry of the in-plane motion of the pyridinium cation and reveal that it is similar to the motion previously observed in bis-thiourea pyridinium iodide. Molecular dynamics (MD) simulations have been performed to investigate the cation dynamics on the high temperature phase of the full series of compounds: bis-thiourea pyridinium chloride, bromide and iodide. Three different models of intermolecular potential have been tested and the agreement between the simulated and experimental elastic incoherent structure factors (EISFs) is used to select the more realistic one. The detailed analysis of the MD results indicates that Coulombic interactions together with the formation of hydrogen bonds between the pyridinium cation and the host sublattice influence strongly the geometry of the in-plane cation reorientation.

Molecular dynamics simulation of cation dynamics in bis-thiourea pyridinium nitrate inclusion compound

Molecular dynamics simulations have been performed on the high temperature phase of the bis-thiourea pyridinium nitrate inclusion compound. Three different potential models have been tested. In the three cases, the analysis of the centre of mass motion of pyridium cations indicates that they do not diffuse along the channels. However, only the potential including a specific hydrogen bonding interaction provides a description of the in-plane cation reorientation in reasonable agreement with the experimental results deduced from quasielastic neutron scattering (QENS) measurements. This model shows that the pyridinium cation reorients among three non-equivalent positions and gives reorientational correlation times comparable to those extracted from the QENS data. We conclude that the particular geometry of this reorientation is due to the formation of hydrogen bonds of different strength between the pyridinium cation of the guest sublattice and the host sublattice.

Complete Sequence and Enhancer Function of the Homologous DNA Regions of Autographa californica Nuclear Polyhedrosis Virus

The nucleotide sequence of the five regions of homologous DNA in the genome of Autographa californica nuclear polyhedrosis virus DNA was determined. The homology of repeated sequences within a region was 65 to 87%, and the consensus sequences for each region were 88% homologous to each other. Sequences proximal to the EcoRI sites were most conserved, while the distal sequences were least conserved. The EcoRI sites formed the core of a 28-base-pair imperfect inverted repeat. All homologous regions functioned as enhancers in a transient expression assay. A single EcoRI minifragment located between EcoRI-Q and -L enhanced the expression of 39CAT as efficiently as the regions containing numerous EcoRI repeats did.

Human adipose-derived mesenchymal stem cells reduce inflammatory and T cell responses and induce regulatory T cells in vitro in rheumatoid arthritis

OBJECTIVES

Adult mesenchymal stem cells were recently found to suppress effector T cell and inflammatory responses and have emerged as attractive therapeutic candidates for immune disorders. In rheumatoid arthritis (RA), a loss in the immunological self-tolerance causes the activation of autoreactive T cells against joint components and subsequent chronic inflammation. The aim of this study is to characterise the immunosuppressive activity of human adipose-derived mesenchymal stem cells (hASCs) on collagen-reactive T cells from patients with RA.

METHODS

The effects of hASCs on collagen-reactive RA human T cell proliferation and cytokine production were investigated, as well as effects on the production of inflammatory mediators by monocytes and fibroblast-like synoviocytes from patients with RA.

RESULTS

hASCs suppressed the antigen-specific response of T cells from patients with RA. hASCs inhibited the proliferative response and the production of inflammatory cytokines by collagen-activated CD4 and CD8 T cells. In contrast, the numbers of IL10-producing T cells and monocytes were significantly augmented upon hASC treatment. The suppressive activity of hASCs was cell-to-cell contact dependent and independent. hASCs also stimulated the generation of FoxP3 protein-expressing CD4(+)CD25(+) regulatory T cells, with the capacity to suppress collagen-specific T cell responses. Finally, hASCs downregulated the inflammatory response and the production of matrix-degrading enzymes by synovial cells isolated from patients with RA.

CONCLUSIONS

The present work identifies hASCs as key regulators of immune tolerance, with the capacity to suppress T cell and inflammatory responses and to induce the generation/activation of antigen-specific regulatory T cells.

[Huntington's disease mortality in Spain in the period 1981-2004]

INTRODUCTION

Huntington's disease (HD) is an autosomic dominant neurodegenerative disease characterized by neuromuscular, cognitive and psychiatric symptoms.

AIM

To analyze the mortality trend for HD from 1981-2004 in Spain.

PATIENTS AND METHODS

Both crude and specific rates adjusted to the European population were used to show the evolution of mortality. Rates are showed by age and gender per million of inhabitants. Joinpoint regression model was used to analyze mortality trends.

RESULTS

866 deaths under HD codes were recorded in Spain during the study period (452 males and 414 females). Adjusted rates ranged from 0.64 in 1981 to 1.65 in 2004 in males and from 0.40 in 1981 to 1.16 in 2004 in females. The trend of the mortality rates in both genders followed a slight and steady increase during the whole period and dramatic changes were not detected. The average yearly percentage of this increase was 3.76% in males and 3.67% in females.

CONCLUSIONS

The study has showed a yearly age adjusted mortality rates increase close to 4%. No differences have been seen between males and females. The follow up of this trend should be monitored to test if it stabilizes or it rises.

A measles outbreak in children under 15 months of age in La Rioja, Spain, 2005-2006

This paper describes a measles outbreak in La Rioja, Spain, which began in December 2005 and mainly affected children under 15 months of age who were not yet immunised with MMR vaccine. The measles cases were detected by the mandatory reporting system, under which laboratories must report every confirmed measles case. Cases were classified in accordance with the National Measles Elimination Plan: suspected and laboratory-confirmed. In the period 14 December 2005 to 19 February 2006, 29 suspected cases of measles were investigated, and 18 were confirmed. The mean incubation period was 13.8 days (range: 9 to 18). Of the 18 confirmed cases, only two were in adults. MMR vaccination was recommended for all household contacts, as well as for children aged 6 to 14 months who attended the daycare centres where the cases had appeared. At these centres, the second dose of MMR was administered ahead of schedule for children under three years of age. It was recommended that the first dose of MMR vaccine be administered ahead of schedule for all children aged 9 to 14 months. During an outbreak of measles, children aged 6 months or older, who have not previously been vaccinated against measles, mumps and rubella, should receive a first dose as soon as possible, and those who have had a first dose should receive a second dose as soon as possible, provided that a minimum of one month has elapsed between the two doses

The RASSF1A isoform of RASSF1 promotes microtubule stability and suppresses tumorigenesis

The RASSF1A isoform of RASSF1 is frequently inactivated by epigenetic alterations in human cancers, but it remains unclear if and how it acts as a tumor suppressor. RASSF1A overexpression reduces in vitro colony formation and the tumorigenicity of cancer cell lines in vivo. Conversely, RASSF1A knockdown causes multiple mitotic defects that may promote genomic instability. Here, we have used a genetic approach to address the function of RASSF1A as a tumor suppressor in vivo by targeted deletion of Rassf1A in the mouse. Rassf1A null mice were viable and fertile and displayed no pathological abnormalities. Rassf1A null embryonic fibroblasts displayed an increased sensitivity to microtubule depolymerizing agents. No overtly altered cell cycle parameters or aberrations in centrosome number were detected in Rassf1A null fibroblasts. Rassf1A null fibroblasts did not show increased sensitivity to microtubule poisons or DNA-damaging agents and showed no evidence of gross genomic instability, suggesting that cellular responses to genotoxins were unaffected. Rassf1A null mice showed an increased incidence of spontaneous tumorigenesis and decreased survival rate compared with wild-type mice. Irradiated Rassf1A null mice also showed increased tumor susceptibility, particularly to tumors associated with the gastrointestinal tract, compared with wild-type mice. Thus, our results demonstrate that Rassf1A acts as a tumor suppressor gene.

The influence of the extracellular matrix on the morphology and intracellular pH of cultured astrocytes exposed to media lacking bicarbonate

In previous work we showed that the polygonal shape of hippocampal astrocytes cultured on poly-L-lysine changes to a stellate morphology with loss of actinomyosin stress fibers on exchanging the culture medium for saline buffered with HEPES [Brain Res 946 (2002)12]. By contrast, in bicarbonate-buffered saline containing Ca(2+) astrocytes remained polygonal and continued to express stress fibers. Evidence suggests that stellation induced by saline buffered with HEPES is related to intracellular acidification due to the absence of bicarbonate. Here we studied the influence of the matrix used in preparing astrocyte cultures. Stellation in HEPES-saline occurred on a matrix of fibronectin, but not on matrices of collagen I or IV provided Ca(2+) was present. Laminin partially prevented stellation in HEPES-saline. Further, the intracellular acidification induced by HEPES-saline observed in astrocytes cultured on polylysine was abolished in cells cultured on collagens and was attentuated on a matrix of laminin. Two observations suggested the involvement of integrins and focal adhesions. (1) Treatment of cultures on collagens with a blocking antibody to the beta1 integrin subunit abolished protection against HEPES-induced stellation. (2) Compared with polylysine, astrocytes cultured on collagens expressed increased contents of phosphotyrosine proteins, focal adhesion proteins vinculin and paxillin, the beta1 integrin subunit and increased numbers of focal adhesions labelled with anti-vinculin. The observation that astrocytes cultured on collagen I or IV, in contrast to polylysine, express stress fibers and a constant intracellular pH in the absence of buffering by bicarbonate may be related to the fact that in the intact brain astrocytic processes (or end-feet) encounter and bind to collagen IV and laminin in the basement membrane of the endothelial cells which surround the cerebral capillaries. It is also possible that astrocytes retain this capacity from early development when fibrous matrix proteins are present.

Treatment of neuroendocrine tumours with infusional 5-fluorouracil, folinic acid and streptozocin

A standardised, effective systemic therapy for metastatic neuroendocrine tumours (NETs) has not been established to date. We reviewed the management of 15 patients with inoperable, metastatic NET treated systematically with a combination chemotherapy regimen of infusional 5-fluorouracil, folinic acid and streptozocin. Overall objective response rate was 53% and tolerability was excellent.

From genome to vaccine: in silico predictions, ex vivo verification

Bioinformatics tools enable researchers to move rapidly from genome sequence to vaccine design. EpiMer and EpiMatrix are computer-driven pattern-matching algorithms that identify T cell epitopes. Conservatrix, BlastiMer, and Patent-Blast permit the analysis of protein sequences for highly conserved regions, for homology with other known proteins, and for homology with previously patented epitopes, respectively. Two applications of these tools to epitope-driven vaccine design are described in this review. Using Conservatrix and EpiMatrix, we analyzed more than 10000 HIV-1 sequences and identified peptides that were potentially immunostimulatory and highly conserved across HIV-1 clades. MHC binding assays and CTL assays have been carried out: 50 (69%) of the 72 candidate epitopes bound in assays with cell lines expressing the corresponding MHC molecule; 15 of the 24 B7 peptides (63%) stimulated gamma-interferon release in ELISpot assays. These results lend support to the bioinformatics approach to selecting novel, conserved, HIV-1 CTL epitopes. EpiMatrix was also applied to the entire 'proteome' derived from two Mycobacterium tuberculosis (Mtb) genomes. Using EpiMatrix, BlastiMer, and Patent-Blast, we narrowed the list of putative Mtb epitopes to be tested in vitro from 1600000 to 3000, a 99.8% reduction. The pace of vaccine design will accelerate when these and other bioinformatics tools are systematically applied to whole genomes and used in combination with in vitro methods for screening and confirming epitopes.

Genetic polymorphism in eight Chilean strains of the carotenogenic microalga Dunaliella salina Teodoresco (Chlorophyta)

Eight Chilean strains of Dunaliella salina obtained within a restricted geographic range, but exhibiting a high variability in their morphology, rate of growth and carotenogenic capacity, were analyzed by Random Amplified Polymorphic DNA (RAPD-PCR) Twenty of the 50 random primers (D, P, OPA and OPD series) that were tested amplified reproducible bands and were useful for comparative analysis of the strains. Of 107 polymorphic genetic markers, 49 were strain-specific. A great genetic variability was found among the strains in spite of their geographic proximity. In addition, phenetic analysis of the data showed close agreement between the morphophysiological attributes and the genetic diversity of the strains.

New insights into host factor requirements for prokaryotic beta-recombinase-mediated reactions in mammalian cells

The prokaryotic beta-recombinase catalyzes site-specific recombination between two directly oriented minimal six sites in mammalian cells, both on episomic and chromatin-integrated substrates. Using a specific recombination activated gene expression system, we report the site-specific recombination activity of an enhanced green fluorescent protein (EGFP) fused version of beta-recombinase (beta-EGFP). This allows expression of active beta-recombinase detectable in vivo and in fixed cells by fluorescence microscopy. In addition, cellular viability is compatible with a substantial level of expression of the beta-EGFP protein. Using fluorescence-activated cell sorting, we have been able to enrich cell populations expressing this fusion protein. Application of this strategy has allowed us to study in more depth the host factor requirements for this system. Previous work showed that eukaryotic HMG1 protein was necessary and sufficient to help beta-recombinase activity in vitro. The influence of ectopic expression of HMG1 protein in the recombination process has been analyzed, indicating that HMG1 overexpression does not lead to a significant increase on the efficiency of beta-recombinase-mediated recombination both on episomal substrates and chromatin-associated targets. In addition, beta-recombinase-mediated recombination has been demonstrated in HMG1 deficient cells at the same levels as in wild type cells. These data demonstrate the existence of cellular factors different from HMG-1 that can act as helpers for beta-recombinase activity in the eukaryotic environment.

A retrospective analysis comparing the costs and cost effectiveness of amlodipine and enalapril in the treatment of hypertension

A comparison of treatment costs and cost effectiveness was performed retrospectively by using patient-level data from a randomized, controlled, one-year clinical trial of amlodipine and enalapril in the treatment of mild-to-moderate hypertension. Unit costs of amlodipine and enalapril were applied to the daily dosages of individual patients to calculate the total costs and average costs per patient in each treatment group in the clinical trial on an intent-to-treat basis. Efficacy rates were used to calculate the average treatment costs per success in blood pressure control. Although not statistically significant, amlodipine treatment resulted in a higher efficacy (89.5%) vs. enalapril (85.2%). The average costs per amlodipine-treated patient were consistently lower (-$112.30) than for the enalapril-treated patient by week 50. Treatment with amlodipine resulted in an average cost per success of $609 per patient compared with $772 per enalapril-treated patient. A sensitivity analysis revealed that, in the treatment of mild-to-moderate hypertension over the 50-week treatment period, amlodipine would remain less costly than enalapril, with a decrease in the cost of enalapril of up to 17%, and would remain more cost effective, with a 21% decrease in the cost of enalapril.

A multinational pharmacoeconomic evaluation of acute major depressive disorder (MDD): a comparison of cost-effectiveness between venlafaxine, SSRIs and TCAs

METHODS

We conducted a multinational pharmacoeconomic evaluation comparing the immediate release form of a new class of serotonin norepinephrine reuptake inhibitor (SNRI), venlafaxine IR to the selective serotonin reuptake inhibitors (SSRIs) and the tricyclic antidepressants (TCAs) in the treatment of acute major depressive disorder (MDD) in 10 countries (Germany, Italy, Netherlands, Poland, Spain, Sweden, Switzerland, United Kingdom, United States, and Venezuela). We designed a decision analytic model assessing the acute phase of MDD treatment within a 6-month time horizon. Six decision tree models were customized with country-specific estimates from a clinical management analysis, meta-analytic rates from two published meta-analyses, and a resource valuation of treatment costs representing the inpatient and outpatient settings within each country. The meta-analyses provided the clinical rates of success defined as a 50% reduction in depression scores on the Hamilton Depression Scale (HAM-D) or the Montgomery-Asberg Depression Rating Scale (MADRS). Treatment regimen costs were determined from standard lists, fee schedules, and communication with local health economists in each country. The meta-analytic rates were applied to the decision analytic model to calculate the expected cost and expected outcomes for each antidepressant comparator. Cost-effectiveness was determined using the expected values for both a successful outcome, and a composite measure of outcome termed symptom-free days. A policy analysis was conducted to examine the health system budget impact in each country of increasing the utilization of the most effective antidepressant found in our study.

RESULTS

Initiating treatment of MDD with venlafaxine IR yielded a lower expected cost compared to the SSRIs and TCAs in all countries except Poland in the inpatient setting, and Italy and Poland within the outpatient settings. The weighted average expected cost per patient varied from US$632 (Poland) to US$5647 (US) in the six-month acute phase treatment of MDD. The estimated total budgetary impact for each 1% of venlafaxine utilization, assuming a population of one million MDD patients, ranged from US$1600 (Italy) to US$29,049 (US).

CONCLUSIONS

Within the inpatient and outpatient treatment settings, venlafaxine IR was a more cost-effective treatment of MDD compared to the SSRIs and TCAs. Additionally, the results of this investigation indicate that increased utilization of venlafaxine in most settings across Europe and the Americas will have favorable impact on health care payer budgets. ADR, adverse drug reaction; CMA, clinical management analysis; ECT, electroconvulsive therapy; HAM-D, Hamilton Depression Scale; MADRS, Montgomery-Asberg depression rating scale; MDD, major depressive disorder; SFD, symptom-free day; SNRI, serotonin-norepinephrine reuptake inhibitor; SSRI, selective serotonin reuptake inhibitor; TCA, tricyclic antidepressant; WHO, world health organization.

Molecular approach to the interpretation of the dielectric relaxation spectrum of a molecular glass former

The frequency-dependent dielectric function of ethanol at temperatures within the normal liquid range is evaluated by means of computer molecular dynamics simulations and compared with recent experimental data. The calculated spectra show a similar structure to those reported from experimental measurements and the temperature dependence of its most prominent bands also follows the experimental estimates. An attempt is also made to assign the most intense bands to specific molecular reorientations.

An interactive multimedia training system for advanced cardiac life support

This paper describes an Advanced cardiac life support (ACLS) training system (ACLSYS) with multimedia and hypertext features for training medical personnel and evaluating their performance during ACLS events. ACLSYS runs in a Windows 95 environment and is written in Visual Basic 4.0 Enterprise Edition and Access 7.0. The system consists of two primary modules: a multimedia training module and a simulation/evaluation module. The training module provides the knowledge and skills required for the appropriate early treatment of cardiopulmonary arrest. The simulation/evaluation module generates randomly an unlimited number of ACLS cases. These cases become part of the training case database and are available for retraining. ACLS certified personnel were included in the validation of the system.

An integrated logistics support system for training crew medical officers in advanced cardiac life support management

The purpose of this paper is to present an approach for the development of an integrated logistics support system for training space flight crew medical officers in advanced cardiac life support (ACLS). The most practical approach to deal with this problem has been determined to be the training of one or more of the crew members on the mission as crew medical officers (CMO's). If this approach is taken, there are a number of problems that must be addressed. The basic approach presented in this paper is to develop a performance quality index for ACLS tasks and use this index to monitor and control the performance of crew members throughout their tenure as CMO's. The control tool of the system is based on an integrated learning and forgetting model used to forecast CMO performance level at a given point during flight training. The model represents an aid for trainers in determining a training regime and maintaining the performance standards. A performance evaluator and trainer is also developed to help in the establishment of trainee performance level during training or retraining. All of these tools were evaluated using either expert opinion questionnaires or experimental results. In conclusion, the results presented provide the tools required for an integrated logistics support system for training ACLS personnel.

An immunohistochemical examination of the expression of E-cadherin, alpha- and beta/gamma-catenins, and alpha2- and beta1-integrins in invasive breast cancer

This study examines the expression of the cell-cell adhesion molecules E-cadherin and its associated proteins, the catenins and the matrix-cell adhesion molecules beta1- and alpha2-integrins, in primary invasive breast carcinoma. Expression was assessed immunohistochemically on frozen sections by semi-quantitative scoring of the intensity and proportion of immunoreactivity in 55 cases. Associations with each other and with other histological and prognostic features and survival were sought. There was a significant association between loss of E-cadherin expression and loss of alpha- and beta/gamma-catenin immunostaining. In 20 per cent of cases, membranous immunoreactivity with E-cadherin antibody was absent. Absent cytoplasmic expression of alpha- and beta/gamma-catenins was seen in 24 and 22 per cent of breast cancers, respectively. The intensity of reactivity with E-cadherin showed a significant association with histological grade (p=0.002) and tumour type (p<0.001). Lobular carcinomas frequently showed loss of expression of E-cadherin, as reported elsewhere; loss of catenin expression was also found in these tumours. alpha-catenin intensity also showed a relationship with grade (p=0.008) and with oestrogen receptor (ER) status (p=0.006). beta/gamma-catenin expression was not associated with other known prognostic factors. Forty-nine per cent and 42 per cent of cases showed no membrane immunostaining with beta1- and alpha2-integrin, respectively, and co-ordinated loss of beta1- and alpha2-integrin expression was found. Both beta1- and alpha2-integrin expression were associated with histological grade (p=0.003 and p=0.031, respectively) and beta1 immunoreactivity with tumour type (p=0.010). None of the variables examined showed a statistically significant association with tumour size or lymph node stage, or with overall survival, although a trend was seen (p=0.087) towards poorer survival of patients with tumours with absent or weak expression of beta1-integrin. The expression of these markers is of biological interest, but appears to be of little additional use in predicting clinical behaviour.

Intracellular alkalinisation in Vero cells parasitised by Trypanosoma cruzi

We studied the intracellular pH of Vero cells parasitised by Trypanosoma cruzi, using different methods: fluorimetric measurement after labelling the cells with the pH-sensitive intracellular fluorescent dye 2',7',-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein, acetoxymethyl ester; flow cytometry; and image analysis after staining the cells with neutral-red vital stain. The results show that the intracellular pH of the parasitised cells rose in comparison with that of the uninfected control cells. A study of the population of parasitised cells made by flow cytometry allowed us to subdivide the cells from the infected cultures into two populations according to their pH as obtained by fluorimetric measurements. Image analysis showed that the cell cytoplasm was more alkaline in the vicinity of the sites containing parasites. Treatment of the parasitised cells with amiloride, ouabain, or with 4.4'-diisothiocyano-2,2'-stilbene disulphate consistently lowered the pH values of the parasitised cells, but not sufficiently to return to the values of the non-parasitised control cells. When the control cells were subject to similar treatments with the inhibitors, only amiloride acidified the cytoplasm to any extent. The basification undergone by the parasitised cells was independent of the transport systems and may be a consequence of the release of NH4+ by the intracellular amastigotes.

[Assessment of glomerular filtration rate in a hospital population. Comparison of two methods]

OBJECTIVES

This study was undertaken to assess the value of Cockroft-Gault Formula (FCG) in the patients of an Internal Medicine ward.

METHODS

FCG was compared with creatinine clearance (DC) adjusted for corporal area. Serum creatinine was measured after 24 h urine collection and 8 h fast. By the subtraction of FCG from DC, the variable difference (DIF) was calculated. FCG was calculated using total body weight (PT) and lean body weight (PS). All patients were included unless they had renal failure.

RESULTS

Renal function was calculated in 92 patients, 33 women and 59 men. Mean age was 60.8 +/- 17.9 (13-87). Mean FCG (64.7 +/- 27.4) and mean DC (68.4 +/- 32.6) were not significantly different and a correlation between them was found (r = 0.68; p < 0.001). Using PS to estimate FCG the correlation coefficient was increased to 0.75 (p < 0.001). DC and FCG using PT or PS correlated inversely with age (r = 0.59; r = 0.53; r = 0.66, respectively; p < 00.1). In a cluster analysis model we could find that for extremes of renal function FCG overestimated (DIF = -10.4 +/- 13.3) or underestimated (DIF = 29.8 +/- 29.7) DC. The main influence for the difference between the two methods was body weight (r = -0.69; p < 0.001). The distribution by diagnosis led to two classes of patients for whom DIF was significantly different (p < 0.02), and body weight was the main factor.

CONCLUSION

Cockroft-Gault formula, although correlating with creatinine clearance, over or underestimates creatinine clearance for extremes of renal function. Age and body weight were the main factors for the differences found between the two methods.

Long-term survival of free fat grafts in muscle: an experimental study in rats

In this study, we showed both macroscopically and microscopically the viability of the autotransplanted fat placed intramuscularly in long-term follow-up. The study was performed on 120 Wistar rats during a 12-month period. The fat grafts were obtained from either the inguinal region or preurinary bladder cavity. Rats were divided into six groups. In group 1, the fat was injected in thin rolls in the frontal subcutaneous layer. In group 2, the fat was injected in thin rolls in the gluteus superficialis, biceps femoris, gastrocnemius, and semitendinosus muscles. In group 3, 6 mm x 2 mm fat strips were placed subcutaneously in the frontal region. In group 4, the same dimension of fat strips were placed in the gluteus superficialis and biceps femoris muscles. In group 5, large cystic spaces of fat were injected subcutaneously in the frontal region, and in group 6, large cystic spaces of fat were injected intramuscularly. Rats at 3, 6, 9, and 12 months after fat grafting were sacrificed in order to carry out the macroscopic observations. The results showed clinical and microscopic success in groups 2 and 4, and problems and failure with the remaining groups.

The effect of salinity on the growth and carotenogenesis in two Chilean strains of Dunaliella salina Teodoresco

We studied the effect of salt concentration on the growth and carotenogenesis in two Chilean strains of Dunaliella salina, CONC-006 and CONC-007, cultivated in two media of different chemical composition J/l and PES, under controlled laboratory conditions. Growth rates, k (div day-1), intrinsic production rates of total carotenoids per unit time rcar (day-1), maximum levels of total carotenoids, K (mg l-1), and maximum production of total carotenoids per unit time, rK/4 (micrograms l-1 day-1) were estimated from growth and carotenogenesis data. The highest maximum productivity of total carotenoids was 978 micrograms l-1 day-1 obtained in CONC-007 at 25% NaCl, and the lowest 15 micrograms l-1 day-1, in CONC-006 at 30% NaCl, both growing in PES medium. CONC-007 showed the highest growth rates, 0.76 and 0.65 div day-1, at the lowest salt concentration (5%) in PES and J/1, respectively. On the contrary, the strain CONC-006 exhibited a different growth pattern in both media. Its maximum growth rate in J/1 was 0.37 div day-1 at 20% NaCl, and in PES, 0.53 div day-1 at 5% NaCl. According to these results, the best integration of growth and carotenogenesis in CONC-007 was obtained at 15% NaCl in J/1 from 10 to 25% NaCl in PES and in CONC-006, from 5 to 20% NaCl in J/1 and from 5 to 10% NaCl in PES.

Occupational allergic contact dermatitis in construction workers

We report the patch test results of 449 construction workers who came as patients to the Occupational Dermatology Service of the Instituto Nacional de Medicina y Seguridad del Trabajo in Madrid between 1989 and 1993. 90.8% of them were patch tested, because they had cutaneous lesions or a clinical history suggestive of occupational dermatitis. 65.5% (268) of those patch tested showed one or more reactions connected with their work. Chromate at 42.1% was the main allergen, followed by cobalt, 20.5%, nickel, 10%, and epoxy resin, 7.5%. 25.9% (106) of patients showed sensitization to rubber components, the majority at 23.7% to thiuram mix, with TETD being the main allergen.

Myoplasmic Ca2+ concentration during exertional rhabdomyolysis

Exertional rhabdomyolysis can destroy muscle but the pathophysiology is unknown. Using intracellular selective microelectrodes, we found that intracellular Ca2+ concentration ([Ca2+]i) was 1.27 (0.17) mumol/L (median and interquartile range) in skeletal-muscle biopsy specimens from patients with exertional rhabdomyolysis compared with 0.12 (0.01) mumol/L in controls. 3 days treatment with dantrolene, a drug that inhibits Ca2+ release from the sarcoplasmic reticulum, decreased [Ca2+]i to 0.22 (0.05) mumol/L and accelerated patients' recovery. This study demonstrated that exertional rhabdomyolysis is associated with elevated [Ca2+]i, and that dantrolene has a beneficial effect in this syndrome.

Dissociation between anti-infarct effect and anti-edema effect of ischemic preconditioning

This study tested the hypothesis that preconditioning, by reducing catabolite accumulation during ischemia, reduces osmotic swelling and myocardial necrosis during subsequent reperfusion. Farm pigs were randomly allocated to one of three groups of treatment: a control group undergoing a 48-min coronary occlusion (CO) of the middle left anterior descending artery, a preconditioned group (2 cycles of 5-min CO and 5-min reperfusion before the 48-min CO), or an intracoronary perfusion group receiving a substrate-free anoxic buffer perfusion into the area at risk between minutes 5 and 10 of the prolonged CO. Animals were killed after 30 min (n = 23) or 6 h (n = 31) of reperfusion. Compared with the control group, both ischemic preconditioning and washout of ischemic by-products by transient anoxic perfusion reduced myocardial edema after 30 min of reperfusion (P < 0.002) by 35 and 32%, respectively, but only ischemic preconditioning reduced final infarct size (by 55%, P < 0.006). Myocardial lactate content before reperfusion, measured in an additional series of 12 experiments, was reduced by 35% in animals receiving preconditioning or intracoronary perfusion. Thus ischemic preconditioning has a marked protective effect against reperfusion edema, and this effect can be explained by reduced catabolite accumulation during ischemia. However, there is no evidence from this study indicating that reduced catabolite accumulation and limited reperfusion edema explain the important anti-infarct effect of ischemic preconditioning.

Intracranial pressure dynamics in clinical practice: online PC-based ICP monitoring system

Correct patient management involves determining the exact point on the intracranial pressure/volume (P/V) curve that corresponds to the patient; this requires calculating intracranial elastance (IE). Intracranial pressure (ICP) monitoring systems should provide the necessary information for this purpose. An ICP monitoring unit is presented that acquires ICP, systemic arterial pressure (SAP) and airway pressure (AWP). The cerebral perfusion pressure (CPP) and the mean values and the peak-to-peak values of the two of them (ICPmean, SAPmean, ICPp-p, SAPp-p,) are calculated. Graphs display the temporal evolution (TE) of the ICP and SAP, as well as histograms of the ICP (%) and intracranial pulse amplitude (ICPAmP) with respect to the ICP or CPP during the preceding 3, 6, 12 or 24 h of monitoring. By digital filtering the ICP respiratory and cardiac components (RCICP, CCICP) are calculated. Finally, the pulse amplitudes (AmP) of the ICP, CCICP and RCICP are computed, as well as the average pulses per minute of SAP, CCICP, AWP and RCICP. Two off-line pulse-amplitude and pulse-morphology oriented toolkits display the afore-mentioned curves, histograms and average pulses per minute, and other additional ones, in order to achieve a deeper patient monitoring study.

Oral pharmacokinetics of carbamazepine in dogs from commercial tablets and a cyclodextrin complex

The extent of absorption of carbamazepine from a 2-hydroxypropyl-beta-cyclodextrin/carbamazepine complex was significantly greater and the rate of absorption was faster when compared with an immediate-release carbamazepine tablet in the dog. Six dogs were dosed orally in a two-way crossover study in which the tablet was compared with an equivalent dose of the complex in solution. The area under the curve of concentration versus time for the complex was 5.6 times greater than the tablet, whereas the mean time to reach maximum concentration for the tablet was 1.4 hours versus 0.5 hours for the complex. The complex, therefore, had a greater rate and extent of absorption. A rapidly acting and better absorbed carbamazepine product has the potential to decrease the daily dose of carbamazepine, increase its utility as emergency treatment of epileptic seizures, and provide an acceptable alternative dosage form in patients who are unable to swallow tablets.

An ODA-based coder/decoder for multimedia medical documents

This paper describes the prototype of a coder/decoder based on the Open Document Architecture (ODA) standard for management of medical documents, as well as the working environment in which it has been developed. The prototype has been assessed in an X-Windows-equipped workstation with a relational database containing patient folders (text and still images) from the departmental information system of the liver transplantation unit.

Digitization of medical documents: an X-Windows application for fast scanning

This paper deals with digitization, using a commercial scanner, of medical documents as still images for introduction into a computer-based Information System. Document management involves storing, editing and transmission. This task has usually been approached from the perspective of the difficulties posed by radiologic images because of their indisputable qualitative and quantitative significance. However, healthcare activities require the management of many other types of documents and involve the requirements of numerous users. One key to document management will be the availability of a digitizer to deal with the greatest possible number of different types of documents. This paper describes the relevant aspects of documents and the technical specifications that digitizers must fulfill. The concept of document type is introduced as the ideal set of digitizing parameters for a given document. The use of document type parameters can drastically reduce the time the user spends in scanning sessions. Presentation is made of an application based on Unix, X-Windows and OSF/Motif, with a GPIB interface, implemented around the document type concept. Finally, the results of the evaluation of the application are presented, focusing on the user interface, as well as on the viewing of color images in an X-Windows environment and the use of lossy algorithms in the compression of medical images.

A 40-kilodalton protein binds specifically to an upstream sequence element essential for muscle-specific transcription of the human myoglobin promoter

To define transcriptional control elements responsible for muscle-specific expression of the human myoglobin gene, we performed mutational analysis of upstream sequences (nucleotide positions -373 to +7 relative to the transcriptional start site) linked to a firefly luciferase gene. Transient expression assays in avian and mammalian cells indicated that a CCCACCCCC (CCAC box) sequence (-223 to -204) is necessary for muscle-specific transcription directed either by the native myoglobin promoter or by a heterologous minimal promoter linked to the myoglobin upstream enhancer region. A putative MEF2-like site (-160 to -169) was likewise necessary for full transcriptional activity in myotubes. Mutations within either of two CANNTG (E-box) motifs (-176 to -148) had only minimal effects on promoter function. We identified and partially purified from nuclear extracts a 40-kDa protein (CBF40) that binds specifically to oligonucleotides containing the CCAC box sequence. A mutation of the CCAC box that disrupted promoter function in vivo also impaired binding of CBF40 in vitro. These data suggest that cooperative interactions between CBF40 and other factors including MEF-2 are required for expression of the human myoglobin gene in skeletal muscle.

Dose proportionality of transdermal nitroglycerin

The FDA Cooperative Efficacy Study of transdermal nitroglycerin utilized a combination of marketed products over a wide dose range. Unfortunately, plasma nitroglycerin concentrations were not determined. The current study was conducted to assess plasma nitrate concentrations after transdermal doses of 15, 30, 60, and 105 mg/24 hr employing the FDA Cooperative Study design. Plasma concentrations of nitroglycerin, 1,3-glyceryl dinitrate, and 1,2-glyceryl dinitrate were determined during the 24 hr of application and for 1 hr after transdermal system removal. Dose proportionality was assessed after normalizing the data by theoretical dose. For nitroglycerin, dose-normalized AUC(0-infinity) and Cmax were higher for the 105 mg/24 hr dose than for the other doses. For the metabolites, 1,3-glyceryl dinitrate and 1,2-glyceryl dinitrate, there were no differences in dose-normalized AUC(0-infinity) and dose-normalized Cmax between the dose levels. No differences were seen in Tmax between the dose levels for all three species. Based on the dinitrate metabolites, dose proportionality was seen over the 15 to 105 mg/24 hr dose range. Nitroglycerin, however, was found to be linear only between 15 and 60 mg/24 hr.

Use of an ATP-supplemented medium for the conservation of human semen and the effect of caffeine on the motility of preserved sperm. Results in artificial insemination

Human semen can be preserved at 4 degrees C in an artificial medium containing 15% ATP-MgCl2 for up to 5 d. This method has been applied to samples from subjects with either normal or abnormal semen. After the conservation period the recovery of sperm motility observed was good when low doses of caffeine (3.5 or 7.0 mM) were added.

Role of atrial natriuretic peptide on calcium channel mechanisms involved in catecholamine release from bovine adrenal medulla

The role of the atrial natriuretic peptide on calcium channel mechanisms involved in catecholamine release was studied in the perfused bovine adrenal medulla. The atrial natriuretic peptide (1 nM and 10 nM) did not modify the spontaneous release of catecholamines. Ten nM of atrial natriuretic peptide decreased the output of catecholamines induced by acetylcholine, KCl-depolarizing solutions and angiotensin II. It was ineffective to modify the catecholamine release when calcium channels were blocked or in the presence of calcium-free media. Moreover, the deprivation of the ion calcium in the media decreased the catecholamine release induced by KCl to a lowest level, despite the presence of atrial natriuretic peptide in the perfusate. In conclusion, atrial natriuretic peptide inhibited the induced secretion of catecholamines in the bovine adrenal medulla and interfered as a partial blocker with calcium-dependent mechanisms.