Safety and immunogenicity of heterologous COVID-19 vaccine regimens to deal with product shortage: A randomised clinical trial in an elderly population

Objectives

In a context of COVID-19 vaccine shortages, this study sought to evaluate the safety and efficacy of receiving one dose of Gam-COVID-Vac rAd26 followed by a second COVID-19 vaccine dose of either Gam-COVID-Vac rAd5, ChAdOx1 nCoV-19 or BBIBP-CorV in a cohort of older adults.

Study design

Single-centre, randomised, open label, non-inferiority trial.

Methods

Adults aged ≥65 years who had received one dose of Gam-COVID-Vac rAd26 were randomised in a 1:1:1 ratio to receive a second-dose COVID-19 vaccination of either Gam-COVID-Vac rAd5, ChAdOx1 nCoV-19 or BBIBP-CorV. The primary outcome was the assessment of the humoral immune response to vaccination (i.e. antibody titres of SARS-CoV-2 spike protein at 28 days after second-dose vaccination). In addition, neutralising antibody titres at day 28 for the three schedules were measured.

Results

Of 85 participants who were enrolled in the study between 26 and July 30, 2021, 31 individuals were randomised to receive Gam-COVID-Vac rAd5, 27 to ChAdOx1 nCoV-19 and 27 to BBIBP-CorV. The mean age of participants was 68.2 years (SD 2.9) and 49 (57.6%) were female. Participants who received Gam-COVID-Vac rAd5 and ChAdOx1 nCoV1-19 showed significantly increased anti-S titres at 28 days after second-dose vaccination, but this magnitude of difference was not observed for those who received BBIBP-CorV. The ratio between the geometric mean at day 28 and baseline within each group was 11.8 (6.98-19.89) among patients assigned to Gam-COVID-Vac rAd26/rAd5, 4.81 (2.14-10.81) for the rAd26/ChAdOx1 nCoV-19 group and 1.53 (0.74-3.20) for the rAd26/BBIBP-CorV group. All of the schedules were shown to be safe.

Conclusions

The findings in this study contribute to the scarce information published on the safety and immunogenicity of Gam-COVID-Vac heterologous regimens and will help the development of guidelines and vaccine programme management.

Origin of the Co-Seismic Variations of Elastic Properties in the Crust: Insight From the Laboratory

Seismological observations highlighted that earthquakes are often followed by changes in elastic properties around the fault zone. Here, we studied the origin of these variations using stick-slip experiments on saw-cut granite samples presenting different degrees of bulk damage (i.e., microcracks). Stick-slip events were induced under triaxial compression configuration with continuous active ultrasonic measurements at confining pressures representative of upper crustal conditions (15-120 MPa). Both the P-wave velocity (V P ) and amplitude (A P ) showed drops, concurrently with stress drops, and had a non-monotonic dependence toward the fault's stress state. Our experimental results suggest that co-seismic changes inV P were mostly controlled by the elastic re-opening of microcracks in the bulk, rather than by co-seismic damage or the formation of fault gouge. Co-seismic changes inA P were controlled by a combination of elastic re-opening of microcracks in the bulk and inelastic processes (i.e., co-seismic damage and gouge formation and dilation).

Dynamic weakening during earthquakes controlled by fluid thermodynamics

Earthquakes result from weakening of faults (transient decrease in friction) during co-seismic slip. Dry faults weaken due to degradation of fault asperities by frictional heating (e.g. flash heating). In the presence of fluids, theoretical models predict faults to weaken by thermal pressurization of fault fluid. However, experimental evidence of rock/fluid interactions during dynamic rupture under realistic stress conditions remains poorly documented. Here we demonstrate that the relative contribution of thermal pressurization and flash heating to fault weakening depends on fluid thermodynamic properties. Our dynamic records of laboratory earthquakes demonstrate that flash heating drives strength loss under dry and low (1 MPa) fluid pressure conditions. Conversely, flash heating is inhibited at high fluid pressure (25 MPa) because water's liquid-supercritical phase transition buffers frictional heat. Our results are supported by flash-heating theory modified for pressurized fluids and by numerical modelling of thermal pressurization. The heat buffer effect has maximum efficiency at mid-crustal depths (~2-5 km), where many anthropogenic earthquakes nucleate.

Photothermal model fitting in the complex plane for thermal properties determination in solids

Thermal properties of solids are obtained by fitting the exact complex photothermal model to the normalized photoacoustic (PA) signal in the front configuration. Simple closed-form expressions for the amplitude and phase are presented in all frequency ranges. In photoacoustic it has been common practice to assume that all the absorptions of radiation take place in the sample. However, in order to obtain the accurate thermal properties it is necessary to consider the PA signal contributions produced at the cell walls. Such contributions were considered in our study. To demonstrate the usefulness of the proposed methodology, commercial stainless steel layers AISI 302 were analyzed. It is shown that using our approach the obtained thermal diffusivity and effusivity were in good agreement with those reported in the literature. Also, a detailed procedure for the calculation of the standard error in the thermal properties is discussed.

Dimethyl sulfoxide (DMSO) as a potential contrast agent for brain tumors

Dimethyl sulfoxide (DMSO) is commonly used in preclinical studies of animal models of high-grade glioma as a solvent for chemotherapeutic agents. A strong DMSO signal was detected by single-voxel MRS in the brain of three C57BL/6 control mice during a pilot study of DMSO tolerance after intragastric administration. This led us to investigate the accumulation and wash-out kinetics of DMSO in both normal brain parenchyma (n=3 control mice) by single-voxel MRS, and in 12 GL261 glioblastomas (GBMs) by single-voxel MRS (n=3) and MRSI (n=9). DMSO accumulated differently in each tissue type, reaching its highest concentration in tumors: 6.18 ± 0.85 µmol/g water, 1.5-fold higher than in control mouse brain (p<0.05). A faster wash-out was detected in normal brain parenchyma with respect to GBM tissue: half-lives of 2.06 ± 0.58 and 4.57 ± 1.15 h, respectively. MRSI maps of time-course DMSO changes revealed clear hotspots of differential spatial accumulation in GL261 tumors. Additional MRSI studies with four mice bearing oligodendrogliomas (ODs) revealed similar results as in GBM tumors. The lack of T(1) contrast enhancement post-gadolinium (gadopentetate dimeglumine, Gd-DTPA) in control mouse brain and mice with ODs suggested that DMSO was fully able to cross the intact blood-brain barrier in both normal brain parenchyma and in low-grade tumors. Our results indicate a potential role for DMSO as a contrast agent for brain tumor detection, even in those tumors 'invisible' to standard gadolinium-enhanced MRI, and possibly for monitoring heterogeneities associated with progression or with therapeutic response.

Immunohistochemical and morphometric study of pituitary pars distalis folliculostellate cells of nonpregnant and pregnant viscachas

Pituitary folliculostellate cells (FSC) have several functions. Morphological, immunohistochemical and physiological characteristics of these cells have been reported for many mammalian species. There is little information, however, about the effect of pregnancy on FSC, particularly in wild animals. We conducted an immunohistochemical and morphometric study of the effect of pregnancy on FSC in viscacha, a seasonal breeder with a long gestation period. Immunohistochemistry and image analysis were used to measure the percentages of S-100-positive total, cellular, and colloidal areas and the number of FSC. In all groups studied, FSC were either isolated or arranged in small groups. These cells exhibited irregular nuclei, stellate shape, and cytoplasmic processes that delimited the follicles or contacted blood vessels. They expressed S-100 protein, which was localized both intracellularly (FSC) and extracellularly (follicular colloid). Some FSC were immunostained by anti-GFAP or anti-vimentin in the cytoplasm surrounding the nucleus and in the cytoplasmic processes, respectively. Morphometric parameters showed variation between nonpregnant and pregnant females. These variations were greatest during mid-pregnancy. We demonstrated that distribution of the FSC in pituitary pars distalis and expression of S-100 protein differ in nonpregnant and pregnant viscachas. Our findings suggest that FSC are involved in intrapituitary regulation of the hormone-secreting cells during pregnancy, probably by a paracrine mechanism.

Razón de sexos y morfometría de Calidris minutilla (Aves, Scolopacidae) en Cuba: un análisis a partir de especímenes en colecciones científicas

Sex ratio and morphometrics of Calidris minutilla (Aves, Scolopacidae) in Cuba: an analysis of specimens in scientific collections Calidris minutilla (Least Sandpiper) populations exhibit morphometric variation across breeding and wintering sites. We documented sex ratio (N = 99) and morphological measurements (N = 49) of Least Sandpiper inhabiting Cuba using specimens in museum collections. We also assessed bill length variation in relation to the longitude (degrees) and type of coastal zone where sampling was conducted. Proportion of female was 0.47 and morphometric measurements were within the range described for the species. Differences in bill length were explained by sex but not by sampling site characteristics.

Genotype and phenotype correlations in diabetic patients in Uruguay

To differentiate among different types of diabetes is becoming an increasingly challenging task. We investigated whether the patient's genetic profile is useful to identify the particular type of diabetes, to determine the corresponding hyperglycemia pathogenesis and treat accordingly. Three hundred and thirty-eight diabetic patients, diagnosed according to American Diabetes Association criteria, were recruited from 2004 to 2008 in diabetes health reference centers. We analyzed the major gene for type 1 diabetes susceptibility (HLA DQ/DR). In order to improve our understanding of the pathogenesis of the resulting hyperglycemia and to implement a more adequate treatment for the patients, we reclassified our sample according to the presence or absence of the genetic markers. We found that a higher percentage of people than expected have immunological disease, independent of their phenotype, with a relative risk of 4.62 (95% confidence interval). This methodology allowed us to establish an association between the genotype and its resulting phenotype. We found significant differences; the phenotypic classification did not reflect immunological disease based on genotype. Moreover, when we examined markers, body mass index and age of onset, we found that many people have an intermediate phenotype between type 1 and type 2. This genetic data can help provide an accurate definition of the disease and would therefore provide the physician a better possibility of providing adequate treatment.

Quality management indicators for tissue banks: an operative model from the period of 2002-2007

AIM

The purpose of this study was to determine a specific indicator model to evaluate the Quality Management System (QMS) in Tissue Banks (TB) for deceased and/or live donors.

METHODS

Quantitative Indicators for Quality Management are considered for deceased donors as the origin of therapeutic tissues. A glossary of definitions was established (also applicable for tissues from live donors): Deceased Therapeutic Real Donors (DTRD), donors that were processed and at least 1 tissue was harvested for a therapeutic purpose; Deceased Effective Donors (DED), DTRD in which 1 or more tissues were validated, stored, and/or grafted; Processed Tissues (PT), number of tissues harvested from a DTRD, which were processed and counted as final product units; Validated Tissues (VT), number of tissues as final product units, which fulfilled quality criteria to be grafted; Grafted Tissues (GT), number of transplanted tissues for therapeutic purposes; and Grafted Patients (GP), number of patients who were grafted with validated tissues. MANAGEMENT QUANTITATIVE INDICATORS: Deceased donors were considered from 2002 to 2007. The total number of tissues was 15,363: Productivity Index (PI), PI = DED/DTRD; Processing Quality Rate (PQR), PQR = VT/PT%; Productivity Efficiency per Donor (PED), PED = VT/DED; Grafted Tissues Coefficient (GTC), GTC = GT/VT; and Grafted Patients Index per Donor (GID), GID = GP/DED.

RESULTS

Results were as follows: PI = 0.80; PQR = 76%; PED = 30.99; GTC = 0.93; and GID = 4. In our study, 80% of DTRD produced VT (PI = 0.80), which represented 76% of PT (average, 31 final products per donor). Also, 93% of the VT were grafted with 5 patients grafted per donor.

CONCLUSIONS

Defined variables resulted in useful tools to evaluate QMS in a TB.

[Budd-Chiari syndrome associated with systemic aspergillosis. Case report and literature review.]

Budd-Chiari syndrome is a very rare disease related to hepatic vein obstruction. Vascular invasion by fungus is seldom seen and reported. After thorough research of the literature only three cases have been reported. We reported a case of a diabetic patient who showed an acute and aggressive disease, characterized by sepsis, acute hepatic failure and death. Postmortem examination showed disseminated aspergillosis, massive hepatic necrosis, hepatic vein thrombosis and venous occlusion by the fungus.

Relationship between efficacy of denileukin diftitox (Dd) and antibody development in cutaneous T-cell lymphoma (CTCL): An analysis of two phase III studies

e19534

Background: Dd is a novel IL-2 receptor-targeted recombinant fusion protein approved for persistent/recurrent CTCL expressing CD25. The effect of antibody titers on efficacy in CTCL was assessed in 2 phase III studies (11 & 14). Methods: Dd doses were 9 or 18 mcg/kg daily for 5 days, repeating every 21 days, up to 8 courses. Serum samples were collected prior to Dd infusion on day 1 of courses 1, 3, 5, and 7. Immune response to Dd was assessed using 2 enzyme-linked immunoassays: 1 for anti-IL-2 antibody (Ab) and the other for anti-Dd Ab. Immunogenicity data reflect percentage of subjects whose test results were considered positive for antibody to the intact Dd fusion protein. Results: In Study 11, 66% of subjects tested positive for anti-Dd Ab at baseline, possibly due to prior exposure to diphtheria toxin or its vaccine. In both studies, and for both doses, rapid increases in Ab titers were observed in nearly 100% of subjects from courses 1 to 3 (∼650-fold, 11; >=625-fold, 14). After 3 treatment courses, mean Ab levels stabilized and did not change appreciably with time. Pharmacokinetic (PK) parameters (Cmax and AUC) decreased substantially during the same period, but no relationship between Ab formation and clearance was identified. Low Spearman Correlation coefficient values indicated lack of a significant association (i) between the pre-treatment or treatment-related Ab levels and (ii) between PK changes for subjects who responded and subjects who did not respond. Of subjects positive for Ab at baseline, 43% (27/63) and 38% (13/34) responded to treatment, as compared to 50% (16/32) and 54% (7/13) for subjects who had no detectable Ab at baseline in Studies 11 and 14 respectively. There appeared to be higher incidences of response in subjects with lower initial Ab titers. Conclusions: In the studies analyzed, antibody formation in response to Dd exposure did not appear to compromise efficacy for treatment of CTCL.

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Ambulatory blood pressure monitoring in patients with hyperthyroidism before and after control of thyroid function

BACKGROUND AND OBJECTIVE

Thyroid hormones have pronounced effects on the cardiovascular system. Thyrotoxicosis affects blood pressure (BP), modifying both diastolic (DBP) and systolic (SBP) pressures. There are no studies examining BP with ambulatory blood pressure monitoring (ABPM) in hyperthyroidism before and after control of thyroid function. Our aims were (1) to analyse ABPM in a group of normotensive hyperthyroid patients before and after normalizing circulating thyroid hormones and (2) to compare these results with those obtained in a group of euthyroid subjects.

PATIENTS AND MEASUREMENTS

We studied 20 normotensive hyperthyroid subjects [18 women; age (mean +/- SEM) 49.0 +/- 3.0 years] and 15 healthy subjects. Patients were evaluated by ABPM over 24 h, at diagnosis and after therapy (n = 18).

RESULTS

The average 24-h, daytime and night-time SBP was significantly greater in hyperthyroid patients than in controls with no significant differences in DBP. Circadian BP rhythm, estimated by the difference between mean values of SBP, DBP and mean BP during daytime and night-time, was unchanged. The average 24-h and daytime SBP significantly decreased after normalizing thyroid function in the 18 hyperthyroid evaluated patients. Daytime SBP and DBP were higher than night-time values both before and after control of thyroid function. However, no differences in circadian BP rhythm were observed.

CONCLUSIONS

Normotensive hyperthyroid patients exhibit higher ambulatory SBP throughout 24 h than normotensive euthyroid subjects. Control of hyperthyroidism decreases ambulatory SBP values. Mean nocturnal fall in BP is comparable in normotensive hyperthyroid patients and control subjects.

Multivariate morphometric discrimination among three species of Lutzomyia subgenus Micropygomyia (Diptera: Psychodidae)

Canonical discriminant analysis accurately separated males of Lutzomyia yencanensis (n = 36) (Ortiz), Lutzomyia cayennensis cayennensis (n = 24) (Floch and Abonnenc) and Lutzomyia micropyga (n = 28) (Mangabeira). Only seven (length of head, interocular distance, wing vein delta, genital filaments, coxite, paramere, and lateral lobe) of 20 possible morphometric measurements were required for differentiation, with a highly significant canonical correlation. The discriminant equations provided a simple, fast, and widely available statistical tool to identify accurately unknown sand fly specimens as L. yencanensis, L. c. cayennensis, or L. micropyga.

Detection of a tryptophan radical in the reaction of ascorbate peroxidase with hydrogen peroxide

The reactivity of recombinant pea cytosolic ascorbate peroxidase (rAPX) towards H2O2, the nature of the intermediates and the products of the reaction have been examined using UV/visible and EPR spectroscopies together with HPLC. Compound I of rAPX, generated by reaction of rAPX with 1 molar equivalent of H2O2, contains a porphyrin pi-cation radical. This species is unstable and, in the absence of reducing substrate, decays within 60 s to a second species, compound I*, that has a UV/visible spectrum [lambda(max) (nm) = 414, 527, 558 and 350 (sh)] similar, but not identical, to those of both horseradish peroxidase compound II and cytochrome c peroxidase compound I. Small but systematic differences were observed in the UV/visible spectra of compound I* and authentic rAPX compound II, generated by reaction of rAPX with 1 molar equivalent H2O2 in the presence of 1 molar equivalent of ascorbate [lambda(max) (nm) = 416, 527, 554, 350 (sh) and 628 (sh)]. Compound I* decays to give a 'ferric-like' species (lambda(max) = 406 nm) that is not spectroscopically identical to ferric rAPX (lambda(max) = 403 nm) with a first order rate constant, k(decay)' = (2.7 +/- 0.3) x 10(-4) s(-1). Authentic samples of compound II evolve to ferric rAPX [k(decay) = (1.1 +/- 0.2) x 10(-3) s(-1)]. Low temperature (10 K) EPR spectra are consistent with the formation of a protein-based radical, with g values for compound I* (g parallel = 2.038, g perpendicular = 2.008) close to those previously reported for the Trp191 radical in cytochrome c peroxidase (g parallel = 2.037, g perpendicular = 2.005). The EPR spectrum of rAPX compound II was essentially silent in the g = 2 region. Tryptic digestion of the 'ferric-like' rAPX followed by RP-HPLC revealed a fragment with a new absorption peak near 330 nm, consistent with the formation of a hydroxylated tryptophan residue. The results show, for the first time, that rAPX can, under certain conditions, form a protein-based radical analogous to that found in cytochrome c peroxidase. The implications of these data are discussed in the wider context of both APX catalysis and radical formation and stability in haem peroxidases.