Anti-endotoxin antibodies consumption in cardiovascular collapse: Pathophysiological concerns

OBJECTIVE

Abnormal endotoxin activity in critically ill patients has been described in the absence of Gram-negative bacterial (GNB) infection. As disease severity seems to be crucial in the detection of this phenomenon, we decided to assess and compare endotoxin exposure in those patients representing the critical situation: septic shock and cardiogenic shock.

DESIGN

Prospective, observational non intervention study.

SETTING

Critical Care Department of a University tertiary hospital.

PATIENTS

Cardiogenic shock (CS) and septic shock (SS) patients.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Follow-up was performed for the first three days. Inflammatory biomarkers (C-reactive protein, procalcitonin and interleuquin-6) and IgM antiendotoxin-core antibodies titter (IgM EndoCAb) were daily analyzed. Sixty-two patients were included; twenty-five patients with SS and thirty-seven with CS. Microbial etiology was established in 23 SS patients (92%) and GNB were present in 13 cases (52%). Although infection was suspected and even treated in 30 CS patients (81%), any episode could be finally confirmed. EndoCAb consumption was more intense in SS patients, although twenty-two CS patients (59.5%) had IgM anti-endotoxin value below 10th percentile range for healthy people. No statistically significant difference in endotoxin exposure was detected between Gram-positive and Gram-negative infections in the SS group. Endotoxin exposure ability to distinguish between SS and CS was moderate (AUC 0.7892, 95% IC: 0.6564-0.9218).

CONCLUSIONS

In the severely ill patient some mechanisms take place allowing endotoxin incursion and therefore blurring the limits of diseases pathophysiology. Our work representatively shows how exposure to endotoxin was not fully capable of distinguishing between CS and SS.

A single-oral bolus of 100,000 IU of cholecalciferol at hospital admission did not improve outcomes in the COVID-19 disease: the COVID-VIT-D-a randomised multicentre international clinical trial

BACKGROUND

Vitamin D status has been implicated in COVID-19 disease. The objective of the COVID-VIT-D trial was to investigate if an oral bolus of cholecalciferol (100,000 IU) administered at hospital admission influences the outcomes of moderate-severe COVID-19 disease. In the same cohort, the association between baseline serum calcidiol levels with the same outcomes was also analysed.

METHODS

The COVID-VIT-D is a multicentre, international, randomised, open label, clinical trial conducted throughout 1 year. Patients older than 18 years with moderate-severe COVID-19 disease requiring hospitalisation were included. At admission, patients were randomised 1:1 to receive a single oral bolus of cholecalciferol (n=274) or nothing (n=269). Patients were followed from admission to discharge or death. Length of hospitalisation, admission to intensive care unit (ICU) and mortality were assessed.

RESULTS

In the randomised trial, comorbidities, biomarkers, symptoms and drugs used did not differ between groups. Median serum calcidiol in the cholecalciferol and control groups were 17.0 vs. 16.1 ng/mL at admission and 29.0 vs. 16.4 ng/mL at discharge, respectively. The median length of hospitalisation (10.0 [95%CI 9.0-10.5] vs. 9.5 [95%CI 9.0-10.5] days), admission to ICU (17.2% [95%CI 13.0-22.3] vs. 16.4% [95%CI 12.3-21.4]) and death rate (8.0% [95%CI 5.2-12.1] vs. 5.6% [95%CI 3.3-9.2]) did not differ between the cholecalciferol and control group. In the cohort analyses, the highest serum calcidiol category at admission (>25ng/mL) was associated with lower percentage of pulmonary involvement and better outcomes.

CONCLUSIONS

The randomised clinical trial showed the administration of an oral bolus of 100,000 IU of cholecalciferol at hospital admission did not improve the outcomes of the COVID-19 disease. A cohort analysis showed that serum calcidiol at hospital admission was associated with outcomes.

TRIAL REGISTRATION

COVID-VIT-D trial was authorised by the Spanish Agency for Medicines and Health products (AEMPS) and registered in European Union Drug Regulating Authorities Clinical Trials (EudraCT 2020-002274-28) and in ClinicalTrials.gov ( NCT04552951 ).

Quantitative analysis of short- and long-distance racing performance in young and adult horses and association analysis with functional candidate genes in Spanish Trotter horses

The association of five candidate genes with sporting performance in young and adult Spanish Trotter horses (STHs) was performed according to a previous selection based on quantitative analysis of the trait time per kilometre (TPK). A total of 334 516 records of TPK from 5958 STHs were used to estimate the estimated breeding values (EBVs) at different age groups (young and adults horses) throughout the range of distances (1600-2700 m) using a bicharacter random regression model. The heritability estimated by distance ranged from 0.16 to 0.40, with a different range for the two age groups. Considering the animals with the best and the worst deregressed EBV, 321 STHs were selected for SNP genotyping in MSTN, COX4I2, PDK4, DMRT3 and CKM genes. An association analysis based on ridge and logistic regression revealed that the young trotters with genotype GG in PDK4 (p < 0.05) and AA of DMRT3 (p < 0.001) SNPs show the best potential in short-distance races, while those carrying the genotype AA in DMRT3 (p < 0.001) and CC in CKM (p < 0.05) genes seem to be the best in long-distance races. Adult trotters with genotype AA in DMRT3 also display greater speed (p < 0.05) and endurance (p < 0.001).

Clinical significance of the detection of Candida albicans germ tube-specific antibodies in critically ill patients

The present study, comprising a prospective multicentre study including 53 non-neutropenic patients from intensive care units (ICU) in six Spanish tertiary-care hospitals, was carried out to determine the clinical significance and influence on mortality of Candida albicans germ tube-specific antibodies (CAGTA). There were 22 patients (41.5%) for whom the CAGTA results were positive, although none of had a blood culture positive for Candida. The intra-ICU mortality rate was significantly lower (p = 0.004) in CAGTA-positive patients (61.2% vs. 22.7%). Multivariate analysis confirmed that a positive CAGTA result was the only protective factor to be independently associated with ICU mortality (beta coefficient = -0.3856; 95% confidence interval = -0.648 to -0.123).

Genetic parameters of biokinematic variables of the trot in Spanish Purebred horses under experimental treadmill conditions

The purpose of this study was to estimate the genetic parameters of biokinematic variables in Spanish Purebred (SPB) horses in order to select those of sufficient interest to be measured in the pre-selection of the animals for possible inclusion in the breeding programme. Kinematic analysis of 130 SPB horses 4.6+/-1.5 years old were recorded at the trot (4m/s) on a treadmill. Genetic parameters were estimated using VCE software and a bivariate mixed animal model including age and stud as fixed effects and animal additive genetic effect and residual error as random effects. In general, heritabilities were high (0.33-0.88). The angular variables presented the lowest heritabilities, whereas the maximum height of the fore-hoof and the duration of swing phase in the hindlimb gave the highest scores. Genetic correlations were also very high, so it was possible to reduce the number of breeding programme characteristics to stride duration, hindlimb swing phase duration, range of stifle and elbow angles, minimal angle of carpus, and minimal retraction-protraction angle of the hindlimb.

Genetic similarity of hepatitis C virus and fibrosis progression in chronic and recurrent infection after liver transplantation

The effect of hepatitis C virus (HCV) genetic heterogeneity on clinical features of post-transplantation hepatitis C is controversial. Different regions of the HCV genome have been associated with apoptosis, fibrosis, and other pathways leading to liver damage in chronic HCV infection. Besides, differences in immunodominant regions, such as NS3, may influence HCV-specific immune responses and disease outcome. In the liver transplant setting, a recent study has reported a positive association between HCV-1b Core region genetic relatedness 5-year post-transplantation and histological severity of recurrent hepatitis C. We have compared nucleotide sequences of HCV Core, NS3 and NS5b regions in HCV-1b-infected patients 3 years post-transplantation (n = 22). A cohort of nontransplanted patients (n = 22) was used as control of natural chronic HCV-1b infection. Histological evaluation was used to define the rate of fibrosis progression. Molecular variance analysis did not show significant differences in HCV sequences between transplanted and nontransplanted patients, or between those with fast or slow fibrosis progression. The same results were obtained when analysing phylogenetic trees for Core, NS3 and NS5b regions. A more appropriate clustering method (using minimum spanning networks) revealed a significant positive relationship between HCV genetic similarity in Core (r = 0.550, P < 0.01) and NS5b regions (r = 0.847, P < 0.01) and the yearly rate of fibrosis progression in nontransplanted patients which, in contrast, was not observed in transplanted patients. Our results indicate that some strains of HCV-1b might be more pathogenic in the natural course of chronic infection by this virus subtype. In the liver transplant setting, when the immune response is severely compromised, other mechanisms are probably more important in determining hepatitis C progression.

De novo hepatitis B after liver transplantation from hepatitis B core antibody-positive donors in an area with high prevalence of anti-HBc positivity in the donor population

Transmission of hepatitis B virus (HBV) infection from donors who are negative for hepatitis B surface antigen (HBsAg-) but positive for antibody to hepatitis B core antigen (anti-HBc+) has been reported. However, previous studies were generally performed in geographic regions with a low prevalence of anti-HBc positivity in the liver donor population. The aims of this study are (1) to assess the risk for de novo hepatitis B in recipients of livers from anti-HBc+ donors in an area of high prevalence of anti-HBc positivity in the donor population, and (2) to analyze the risk factors for acquisition of HBV infection from anti-HBc+ donors. The transplantation experience of a single center between 1995 and 1998 was reviewed. Thirty-three of 268 liver donors (12%) were HBsAg- and anti-HBc+ during the study period. The proportion of anti-HBc+ donors increased with age; it was lowest (3.6%) in donors aged 1 to 20 years and highest (27.1%) in donors aged older than 60 years. Of the 211 HBsAg- recipients with 3 months or more of HBV serological follow-up, 30 received a liver from an anti-HBc+ donor and 181 received a liver from an anti-HBc- donor. Hepatitis B developed in 15 of 30 recipients (50%) of livers from anti-HBc+ donors but in only 3 of 181 recipients (1.7%) of livers from anti-HBc- donors (P < .0001). None of the 4 recipients who were antibody to HBsAg (anti-HBs)+ at the time of transplantation developed HBV infection after receiving a liver from an anti-HBc+ donor compared with 15 of 26 recipients (58%) who were anti-HBs- (P =.10). None of the 5 anti-HBc+ recipients developed hepatitis B compared with 15 of 25 anti-HBc- recipients (60%; P = 0.04). Child-Pugh score was significantly higher in recipients of livers from anti-HBc+ donors who developed HBV infection than in those who did not (9 +/- 2 v 7 +/- 1; P =.03). In our area, testing liver donors for anti-HBc is mandatory, particularly in older donors. With such information available, anti-HBc+ donors can be safely directed to appropriate recipients, mainly those with anti-HBs and/or anti-HBc at the time of transplantation. In the current era of donor shortage, this policy would allow adequate use of such donors.

[Seroprevalence of hepatitis A in hemophiliacs]

PURPOSE

To study the seroprevalence of hepatitis A virus (HAV) infection in haemophiliacs treated with factor VIII/IX concentrates.

PATIENTS AND METHODS

Anti-HAV IgG antibodies were tested in 133 haemophiliacs previously treated (20 of them only infused with virus-inactivated factor concentrates), 11 previously untreated haemophiliacs and 60 healthy individuals (> 25 yr. old).

RESULTS

The overall anti-HAV prevalence was 43%. Anti-HAV was found in 2 (10%) of the patients treated only with virus-inactivated concentrates and in 55 (49%) of those who had received non-inactivated concentrates. The seroprevalence in the untreated haemophiliacs was 27% and 90% in the healthy control group. The anti-HAV seroprevalence showed a significant (p < 0.001) dependence on patient age, it being higher in patients aged > 25 (77%) than in those aged 10-25 (31%) and < 10 (4%). The seroprevalence of anti-HAV was lower in the treated haemophiliacs aged 25 or more than in the healthy individuals, although the difference did not reach statistical significance (p = 0.06).

CONCLUSION

These results show that the seroprevalence of HAV infection in haemophiliacs is similar to that in the general population, and that there is not a significant excess of HAV infections amongst haemophiliacs with high exposure to coagulation factor concentrates.

Characterization of LRP, a leucine-rich repeat (LRR) protein from tomato plants that is processed during pathogenesis

This paper describes the isolation and characterization of LRP, a new gene from tomato plants. The deduced amino acid sequence showed that the encoded protein is enriched in leucine, and contains interesting structural motifs. LRP contains four tandem repeats of a canonical 24 amino acid leucine-rich repeat (LRR) sequence present in different proteins that mediates molecular recognition and/or interaction processes. Genomic organization and intron-exon arrangement of LRP favor the hypothesis that the LRR domains present in LRP evolved by exon duplication and shuffling. LRP expression analysis and immunohistochemical localization studies of the encoded protein indicate that the gene is under developmental regulation exhibiting tissue-specificity, particularly in certain cell types of the stele, like phloem fibers, parenchyma cells of the protoxylem, and in the cell files that constitute the rays of the secondary xylem. It is shown that this gene is upregulated in diseased tomato plants infected with citrus exocortis viroid. However, in this pathogenic context, LRP is processed proteolytically to a lower molecular weight form by a host-induced extracellular protease. The structural characteristics of LRP, its spatio-temporal pattern of expression, and its post-translational processing during pathogenesis, suggest this protein as a candidate molecule that may mediate recognition and interaction events taking place in the plant extracellular matrix under normal and/or pathogenesis-related conditions.

Immunolocalization of lipoxygenase in pea (Pisum sativum L.) carpels

Polyclonal antibodies against a part of pea (Pisum sativum L.) LOXG protein have been raised to study the pattern of distribution of related lipoxygenases in pea carpels. The antiserum recognized three lipoxygenase polypeptides in carpels. One of them became undetectable 24 hours after fruit development induction, suggesting that it may correspond to the protein derived from loxg cDNA. Immunolocalization experiments showed that lipoxygenase protein was present only in pod tissues: it was abundant in the mesocarp and, from the day of anthesis, in the endocarp layers. Lipoxygenase distribution is regulated throughout development. The association of lipoxygenase with cells in which processes of expansion and growth will potentially take place support a role in pod growth and development.

Simultaneous determination of cefepime and L-arginine in injections by second-derivative spectrophotometry

A simple spectrophotometric assay for the determination of cefepime and L-arginine in injections is described. Since zero-order spectra showed considerable overlap, second-derivative spectrophotometry was used to enhance the spectral details. A linear relationship between second-derivative amplitude and concentration of each compound was found. Beer's law was obeyed up to 50 and 22 micrograms ml-1 of cefepime and arginine, respectively, in the second-derivative mode. Detection limits were 0.31 and 0.58 micrograms ml-1 for cefepime and arginine, respectively. The method, which is rapid, simple and does not require any separation step, has been successfully applied to the assay of commercial injections containing cefepime and arginine.

A novel extracellular matrix protein from tomato associated with lignified secondary cell walls

A cDNA clone representing a novel cell wall protein was isolated from a tomato cDNA library. The deduced amino acid sequence shows that the encoded protein is very small (88 amino acids), contains an N-terminal hydrophobic signal peptide, and is enriched in lysine and tyrosine. We have designated this protein TLRP for tyrosine- and lysine-rich protein. RNA gel blot hybridization identified TLRP transcripts constitutively present in roots, stems, and leaves from tomato plants. The encoded protein seems to be highly insolubilized in the cell wall, and we present evidence that this protein is specifically localized in the modified secondary cell walls of the xylem and in cells of the sclerenchyma. In addition, the protein is localized in the protective periderm layer of the growing root. The highly localized deposition in cells destined to give support and protection to the plant indicates that this cell wall protein alone and/or in collaboration with other cell wall structural proteins may have a specialized structural function by mechanically strengthening the walls.

First- and second-derivative spectrophotometric determination of imipenem and cilastatin in injections

First- and second-derivative spectrophotometry has been used for the quantitation of mixtures of imipenem and cilastatin sodium, compounds that have closely overlapping spectral bands. Beer's law was obeyed at concentrations up to 100 micrograms ml-1 of imipenem in both the first- and second-derivative modes and up to 75 micrograms ml-1 of cilastatin in the first-derivative mode. Detection limits at the P = 0.05 level of significance were calculated to be 0.40 and 0.52 micrograms ml-1 of imipenem and cilastatin sodium, respectively, in the first-derivative mode, and in a range from 0.45 to 0.68 micrograms ml-1 for imipenem in the second-derivative mode. The method, which is rapid, simple and does not require a separation step, has been successfully applied to the assay of commercial injections.