COVID-19 fatality rates in hospitalized patients: A new systematic review and meta-analysis

BACKGROUND

SARS-COV2 or COVID-19 disease is an infectious illness that emerged for the first time at the end of 2019, in Wuhan, China and rapidly turned out to be an international pandemic with deleterious effects all over the world. In March 2021, A. Macedo et al., has published the first meta-analysis of hospital mortality, so the authors decided to update those data at a time of emergence of new therapies and increasing vaccination rates.

METHODS

As the outcome of interest was the mortality in hospitalized general patients, the authors looked for articles evaluating the clinical characteristics of those patients, consulting PUBMED (The US National Library of Medicine) and EMBASE (Medical database) in an independent selection using predefined terms of search. A meta-analysis random-effect model was estimated using Mantel-Haenszel method. Heterogeneity among studies was tested using Tau2 statistics and Chi2 statistics.

RESULTS

In a first instance 25 articles were included for final analysis with a total of 103,840 patients, but as the goal was to update the anterior data, these studies were analysed together with the 21 studies of the previous meta-analysis, with a total of 114609 patients. The mortality rate of COVID-19 general patients admitted to the hospital was 16% (95% CI 12; 21, I2 =100%).

CONCLUSION

Global hospital mortality of COVID-19 of general patients was 16%, with quite different rates according to the different geographic areas analysed.

The talk test"s responsiveness to an 8-week exercise-training program in cardiovascular disease patients

Funding Acknowledgements

Type of funding sources: None.

Background

Talk test (TT) is an alternative and accessible tool for prescribing and monitoring aerobic training intensity. Although the TT is reliable and valid for cardiorespiratory assessment, its responsiveness to exercise training remains unexplored.

Purpose

To evaluate the responsiveness of TT in cardiovascular disease (CVD) patients who underwent an exercise training program.

Methods

Twenty-one CVD patients (61.7 ± 8.4 years) performed an exercise-training program on phase II of cardiac rehabilitation (45-min 3-times a week). The six-minute walk test (6MWT) and TT were done to assess functional capacity at baseline and after 8 weeks. In the individualized TT the treadmill’s speed and/or grade were increased every 2-min, with speed changes based on a reference equation for the 6MWT distance (6MWD). The subjects were asked to read a 38 words standard paragraph at the last 30s of each stage and to answer if they could talk comfortably. Answer options were i) YES (TT+), ii) UNCERTAIN (TT±), or iii) NO (TT-). The first ventilatory threshold (VT1) was identified by two reviewers using the heart rate variability analysis. A paired t-test was applied to analyze the TT duration and 6MWD. The VT1 and TT workload were analyzed by the Wilcoxon test. Spearman correlation was adopted to compare the TT± and VT1 stages.

Results

Improvement in the VT1 (2.9 ± 1.2 vs 4.4 ± 1.4 min; p < 0.001), duration (12.1 ± 4.4 vs 14.9 ± 5.2 min; p < 0.001), workload at TT- (67.8 ± 48.4 vs 104.5 ± 65.9 w; p < 0.001), and in the 6MWD (471.5 ± 100.3 vs 533.7 ± 92.9 m; p < 0.001) were observed. There was strong correlation between TT± and VT1 in pre (r = 0.613; p < 0.05) and post-rehabilitation (r = 0.678; p < 0.05).

Conclusion

Talk test performed on a treadmill showed responsiveness after eight weeks of exercise training, being sensitive to the physiological changes provided by the rehabilitation program in CVD patients.

Frailty impairs the endothelial function of elderly with chronic heart failure

Funding Acknowledgements

Type of funding sources: None.

Background

Frailty has a high prevalence of heart failure (HF). It is believed that existing circulatory disturbance increase oxidative stress and chronic inflammation, predisposing to anabolic-catabolic imbalance. Thus, there is impairment of the efficient use of oxygen by skeletal muscles, limiting the physical-functional performance in these individuals. However, little is known about the influence of frailty on endothelial function in the elderly.

Purpose

To analyze the influence of frailty on endothelial function in the elderly with and without HF.

Methods

This was a descriptive cross-sectional study, which included individuals aged ≥60 years, with or without HF, who did not have diabetes, anemia, peripheral obstructive arterial disease and/or congenital heart disease. The Cardiovascular Health Study (CHS) frailty scale criteria were used to assess frailty (phenotype). Endothelial function at rest was evaluated by near-infrared spectroscopy ([NIRS]; slope 1, lowest tissue oxygen saturation [StO2], area under the curve [AUC] of StO2, slope 2, StO2 peak, overshoot, ΔStO2nadir_peak and Δtime nadir_peak) during arterial occlusion maneuver on the forearm. Results were grouped according to the frailty phenotype: robust, pre-frail and frail. Shapiro-Wilk test was used to assess the normality of data. Quantitative data were compared using a two-way analysis of variance plus Bonferroni post hoc test to determine the influence of the frailty or HF on endothelial function variables. A p-value <0.05 was considered statistically significant.

Results

Fifty-two elderly people (61% women) participated in the study, with a mean age of 70.3 ± 7.1 years. Of these, 52% (n = 27) had a diagnosis of HF. Among the sample, 35% (n = 18) were robust, 45% (n = 23) pre-frail, and 20% (n = 11) frail. Endothelial function analysis identified that there was an influence of frailty on reperfusion rate (slope 2 and ΔStO2 nadir-peak; p < 0.05) and desaturation during arterial occlusion (AUC StO2; p < 0.05) only in the HF group.

Conclusion

The coexistence of frailty and HF seems to impair endothelial function since frail elderly with HF had lower reperfusion rate and higher desaturation during the arterial occlusion test.

Abstract Figure. Endothelial function assessment by NIRS

Muscle oxygenation assessment during talk test to determine the anaerobic threshold in individuals with cardiovascular disease

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001.

Background

Cardiopulmonary exercise test (CPET) is the reference method for assessing gas exchange threshold (GET), a surrogate of the anaerobic threshold (AnT). However, muscle oxygenation has been shown as an additional tool for AnT determination, using the lower limb threshold (LLT). Besides, Talk Test (TT), a tool used to assess, prescribe, and monitor exercise intensity through speech comfort level, has shown a correlation with GET as well.

Purpose

To identify the AnT obtained from the traditional method from CPET (GET) and the LLT; to compare heart rate (HR) and tissue saturation index (TSI) data at AnT (GET and LLT); to compare the parameters of LLT on CPET and TT, and to correlate LLT and TT stages in cardiovascular disease (CVD) patients.

Methods

CVD patients underwent CPET and TT, both on a treadmill, in two distinctive days. During those tests, peripheral muscle oxygenation was assessed by the near-infrared spectroscopy method. GET (CPET) was determined by the V-slope method; LLT (CPET and TT) was determined by the visual inspection of oxyhemoglobin and deoxyhemoglobin curves. A TT protocol based on the prediction equation for the covered distance of the six-minute walk test (6MWD) was applied. TT protocol was incremental, with two-minutes stages starting at 70% of the average velocity predicted and 2% of inclination, increasing velocity in 10 percentage points (p.p.) at each stage, until the fifth stage, at which the inclination was increased in 2 p.p. until test completion. At the end of each stage, patients read a standardized paragraph and were asked about speech comfort. Shapiro-Wilk test was performed to assess data distribution. Wilcoxon test was applied to compare physiological variables (HR and TSI) at GET and LLT. Repeated measures analysis of variance (ANOVA), followed by Bonferroni post-hoc test was assessed to compare the variables at LLT and TT stages (last TT+ and first TT±). Spearman correlation coefficient was used to assess the relationship between variables. Statistical significance was set at 5%.

Results

24 cardiovascular patients were included. Similar values of HR (GET vs. LLT: 102 ± 15 bpm vs. 99 ± 14 bpm, p = 0,08), and TSI (GET vs. LLT: 64,6 ± 8,2% vs. 66,4 ± 7,8%, p = 0,09) were observed during CPET. Regarding LLT at CPET and TT, there was no difference between HR (CPET vs. TT: 99 ± 14 bpm vs. 100 ± 12 bpm, p = 1,00) and TSI (CPET vs. TT: 66,4 ± 7,8% vs. 65,3 ± 4,9%, p = 1,00). Furthermore, good relationship between HR in LLT and TT stages (LLT vs. TT+: r = 0,79; LLT vs. TT±: r = 0,76; p < 0,05 for both) was found.

Conclusions

Our results showed similarity between LLT and GET. Besides, TT showed a similar response of muscle oxygenation and heart rate comparing to CPET, with a good correlation between LLT and TT stages. These results endorse the validity of TT as an auxiliary and low-cost tool to identify the AnT.

Fluid-structure effects of cloaking a submerged spherical shell

Backscattering from a cloaked submerged spherical shell is analyzed in the low, mid, and high frequency regimes. Complex poles of the scattered pressure amplitudes using Cauchy residue theory are evaluated in an effort to explain dominant features of the scattered pressure and how they are affected by the introduction of a cloak. The methodology used is similar to that performed by Sammelmann and Hackman [J. Acoust. Soc. Am. 85, 114-124 (1989); J. Acoust. Soc. Am. 89, 2096-2103 (1991); J. Acoust. Soc. Am. 90, 2705-2717 (1991)] in a series of papers written on scattering from an uncloaked spherical shell. In general, it is found that cloaking has the effect of diminishing the amplitude and shifting tonal backscatter responses. Extreme changes of normal and tangential fluid phase velocities at the fluid-solid interface when cloaking is employed leads to elimination of the "mid-frequency enhancement" near the coincidence frequency for even modestly effective cloaks, while reduction of the "high-frequency enhancement" resulting from the "thickness quasi-resonance" near the cut-off frequency of the symmetric (S2(B)) mode requires more effective cloaking, but can be practically eliminated by employing a cloak that creates tangential acoustic velocities in excess of the S2(B) mode phase speed near cutoff.

Myocardial ischemia during endoscopic retrograde cholangiopancreatography - A real problem?

AIM

The occurrence of silent myocardial ischemia during endoscopic retrograde cholangiopancreatography (ERCP) has been documented, but its clinical significance remains unknown. The aims of this study were to investigate the incidence and risk factors of myocardial ischemia during ERCP, to determine the presence or absence of permanent myocardial injury and to evaluate if deep sedation with propofol had a positive effect on myocardial ischemia during ERCP.

METHODS

Ambulatory ST-segment monitoring from 30 minutes prior to 4 hours after ERCP was obtained on 50 patients. A deep sedation was performed with intravenous propofol administered by anesthesiologist. Changes in vital signs during ERCP, pre and postprocedural 12-lead ECG examination and cardiac enzymes were evaluated.

RESULTS

Silent cardiac ischemia occurred only in one patient (2%) during ERCP. This 64-year-old patient did not develop hypoxemia, tachycardia or hypotension periods during the exam. None of the patients developed cardiac enzymes or postprocedural electrocardiographic changes. Thirty seven (74%) patients suffered rhythm changes.

CONCLUSION

Although rhythm disturbances were common, silent myocardial ischemia during ERCP was rare (2%) and without clinical relevance. In prolonged or complex therapeutic procedures, like ERCP, deep sedation with propofol performed by trained personnel is associated with reduced cardiac complications.

Appropriateness of outpatient gastrointestinal endoscopy in a non-academic hospital

AIM: To assess the appropriate use and the diagnostic yield of upper gastrointestinal endoscopy and colonoscopy in this subgroup of patients.

METHODS: In total, 789 consecutive outpatients referred for gastrointestinal (GI) endoscopy [381 for esophagogastroduodenoscopy (EGD) and 408 for colonoscopy] were prospectively enrolled in the study. The American Society for Gastrointestinal Endoscopy (ASGE) guidelines were used to assess the relationship between appropriateness and the presence of relevant endoscopic findings.

RESULTS: The overall inappropriate rate was 13.3%. The indications for EGD and colonoscopy were, respectively, appropriate in 82.7% and 82.6% of the exams, uncertain in 5.8% and 2.4% and inappropriate in 11.5% and 15%. The diagnostic yield was significant higher for EGDs and colonoscopies judged appropriate and uncertain when compared with those considered inappropriate (EGD: 36.6% vs 36.4% vs 11.4%, P = 0.004; Colonoscopy: 24.3% vs 20.0% vs 3.3%, P = 0.001). Of the 25 malignant lesions detected, all but one was detected in exams judged appropriate or uncertain.

CONCLUSION: This study shows a good adherence to ASGE guidelines by the referring physicians and a significant increase of the diagnostic yield in appropriate examinations, namely in detecting neoplastic lesions. It underscores the importance that the appropriateness of the indication assumes in assuring high-quality GI endoscopic procedures.

Effect of salivary factors on the susceptibility of hydroxyapatite to early erosion

OBJECTIVE

Salivary pellicle is known to reduce the erosion of enamel and differences in the level of protection exist between individual saliva sources, but which parameters or components are important is not known. The focus of this study was to investigate the relationship between saliva parameters and early erosion of hydroxyapatite (HAp) with an in situ grown saliva film.

METHODS

Twenty-eight volunteers carried two HAp and one porcelain discs in their buccal sulcus for 1.5 h. Next, the discs covered with pellicle and the attached saliva film were exposed extraorally to 50 mM (pH = 3) citric acid for 2 min and unstimulated and stimulated saliva was collected. Calcium loss from HAp after erosive challenge was measured, corrected for calcium loss from pellicle on porcelain discs and averaged. Several salivary parameters were analysed. Pearson's linear correlation and multiple regression analysis were used to study the relation between saliva parameters and HAp erosion.

RESULTS

Significant correlations were found between HAp erosion and the concentration of phosphorus in unstimulated saliva (r = 0.40, p = 0.03) and between HAp erosion and the concentration of sodium (r = -0.40, p = 0.03), chloride (r = -0.47, p = 0.01), phosphorus (r = 0.45, p = 0.01) and flow (r = -0.39, p = 0.04) of stimulated saliva. Multivariate analysis revealed a significant role in the HAp erosion for sodium, urea, total protein, albumin, pH and flow of unstimulated saliva and for sodium, potassium, urea, and phosphorus of stimulated saliva.

CONCLUSIONS

Several salivary parameters are associated with the susceptibility of HAp to erosion.

In vitro reduction of dental erosion by low-concentration TiF4 solutions

The aims of this study were to compare daily versus single applications of low-concentration TiF(4) solutions for reduction of enamel erosion and to evaluate the enamel surface loss due to application of these solutions. Sixty bovine enamel samples were randomly divided into 2 groups: single versus daily treatment with TiF(4) solution (ST vs. DT), which were subdivided into 5 subgroups (n = 6): 0% (control); 0.1, 0.5, 0.75 and 1% TiF(4) concentration. Fluoride treatment was performed by immersing specimens in 10 ml of the TiF(4) solutions for 5 min and rinsing them with tap water for 30 s. ST specimens were treated once only, DT specimens were treated before each erosion cycle. All specimens were subjected to 4 erosion cycles: 6 immersions of 2 min in Sprite, tap water rinse for 1 min and storage in artificial saliva for 1.5 h. Erosive enamel loss was measured using light profilometry, after each fluoride treatment and each erosive cycle. The values of surface loss/gain at application of the TiF(4) solutions did not significantly differ from zero. At the end of the 4 erosion cycles, 0.5% showed the least (ST: 3.45 ± 0.27 μm, DT: 1.08 ± 1.69 μm) and 1% showed the most surface loss (ST: 4.87 ± 1.13 μm, DT: 6.56 ± 1.49 μm). A significant reduction of surface loss was found only for 0.5% DT (p = 0.009). Within the limitations of an in vitro study, it was concluded that multiple applications of a 0.5% TiF(4) solution significantly reduced enamel erosion in vitro and caused no enamel loss at application.

Influence of beverage composition on the results of erosive potential measurement by different measurement techniques

The influence of beverage composition on the measurement of erosive potential is unclear. The aim of this study was to evaluate whether beverage composition influences the measurement of erosive potential and to evaluate the influence of exposure in small and large volumes. Eleven beverages were included: water (control), 3 alcopops, 2 beers and 5 soft drinks. For each beverage 15 bovine enamel samples were used: 5 for chemical and 10 for profilometric analysis. After exposure to the beverages (63 min) the resulting solutions were analyzed for Ca and inorganic phosphorus (P(i)) content. The samples for optical profilometry were submersed sequentially in 500 ml or in 1 ml of the drinks for 3, 6, 9, 15 and 30 min (total 63 min). For some of the beverages high baseline concentrations of Ca (energy drink) or P(i) (cola drink, cola lemon drink, beer, beer lemon) were found. Some of the beverages showed a good correlation between the chemical methods. Profilometry (both for 1 and 500 ml) showed generally lower enamel losses than the chemical methods. Lower enamel losses were found for the profilometry 1 ml compared to the profilometry 500 ml only for the cola drinks. It can be concluded that the composition of the beverages had a significant effect on the determination of the erosive potential with chemical analyses. Drink composition also influenced the effect of small versus large exposure volumes, indicating the need for standardization of exposure parameters.

ATL-1, an analogue of aspirin-triggered lipoxin A4, is a potent inhibitor of several steps in angiogenesis induced by vascular endothelial growth factor

BACKGROUND AND PURPOSE

Vascular endothelial growth factor (VEGF) is the most important proangiogenic protein. We have demonstrated that ATL-1, a synthetic analogue of aspirin-triggered lipoxin A(4), inhibits VEGF-induced endothelial cell (EC) migration. In the present study, we investigated the effects of ATL-1 in several other actions stimulated by VEGF.

METHODS

Human umbilical vein ECs were treated with ATL-1 for 30 min before stimulation with VEGF. Cell proliferation was measured by thymidine incorporation. Adherent cells were determined by fluorescence intensity using a Multilabel counter. Expression and activity of matrix metalloproteinases (MMP) were analysed by western blot and zymography.

KEY RESULTS

ATL-1 inhibited EC adhesion to fibronectin via interaction with its specific receptor. Furthermore, VEGF-induced MMP-9 activity and expression were reduced by pretreatment with ATL-1. Because the transcription factor NF-kappaB has been implicated in VEGF-mediated MMP expression and EC proliferation, we postulated that ATL-1 might modulate the NF-kappaB pathway and, indeed, ATL-1 inhibited NF-kappaB nuclear translocation. Pretreatment of EC with ATL-1 strongly decreased VEGF-dependent phosphorylation of phosphainositide 3-kinase (PI3-K) and extracellular signal-regulated kinase-2 (ERK-2), two signalling kinases involved in EC proliferation. Inhibition of VEGF-induced EC proliferation by ATL-1 was antagonized by sodium orthovanadate, suggesting that this inhibitory activity was mediated by a protein tyrosine phosphatase. This was confirmed by showing that ATL-1 inhibition of VEGF receptor-2 (VEGFR-2) phosphorylation correlates with SHP-1 association with VEGFR-2.

CONCLUSIONS AND IMPLICATIONS

The synthetic 15-epi-lipoxin analogue, ATL-1, is a highly potent molecule exerting its effects on multiple steps of the VEGF-induced angiogenesis.

The contribution of extensin network formation to rapid, hydrogen peroxide-mediated increases in grapevine callus wall resistance to fungal lytic enzymes

Grapevine (Vitis vinifera cv. Touriga) callus cell walls contain a high level of the monomeric extensin, GvP1. Hydrogen peroxide stimulus of these cultures causes the rapid loss of monomeric GvP1, concomitant with marked increases in insoluble GvP1 amino acids and wall resistance to digestion by fungal lytic enzymes. JIM11 immunolocalization studies indicated that monomeric and network GvP1 were evenly distributed in the callus cell wall. These primary cell walls were used to investigate the specific contribution of extensin and other ionically bound cell-wall proteins to hydrogen peroxide-mediated increases in resistance to fungal lytic enzymes. This was performed by removing ionically-bound proteins and assaying for hydrogen peroxide-enhanced resistance after the addition of selected protein fractions. The results indicate that hydrogen peroxide-induced increases in resistance to digestion by fungal lytic enzymes require a co-operative action between network extensin formation and the electrostatic interaction of additional wall proteins with the extracellular matrix.

Microbial populations of an upflow anaerobic sludge blanket reactor treating wastewater from a gelatin industry

The microbial populations of an upflow anaerobic sludge blanket reactor, used for treating wastewater from the gelatin industry, were studied by microbiological methods and phase-contrast and electron microscopy. Microscopy examination of the sludge showed a complex mixture of various rod-shaped and coccoid bacterial pluslong filaments and verymobile curved rods. In addition free-living anaerobic ciliates and flagellates were also observed. The trophic group population observed in decreasing order of dominance were hydrolytic and acetogenic at 10(6) and sulfate reducing and methanogenic at 10(5). The rate of methane production in anaerobic granular sludge cultivated in growth medium supplement with formate pressurized with H2:CO2 showed a significant increase in methane yield compared with theseed culture containingthe same substrate and atmosphere of N2:CO2. Similar rates of methane production were observed when the growth medium was supplemented with acetate pressurized either with H2:CO2 or N2:CO2. The number of total anaerobic bacteria at 10(7), fecal coliforms and total coliforms at 10(6), and fecal streptococci at 10(3) is based on colony counts on solid media. The four prevalent species of facultative anaerobic gram-negative bacteria that belong to the family of Enterobacteriaceae were identified as Escherichia coli, Esherichia fergusonii, Klebsiella oxytoca, and Citrobacter freundii. The species Aeromonas hydrophila, Aeromonas veronii, Acinetobacter iwoffi and Stenotrophomonas maltophila were the most frequently isolated glucose fermenting and nonfermenting gram-negative bacilli.

The regional distribution of neuronal glycogen in the opossum brain, with special reference to hypothalamic systems

Neurons that accumulate glycogen have been identified in the opossum brain stem and diencephalon by a modified histochemical method using alcoholic solutions and fuchsin proper (pararosanilin) rather than the Schiff reagent (leucosulphite derivative). Several of the glycogen-positive cell groups such as the mesencephalic trigeminal nucleus and the brainstem somatic and special visceral efferent nuclei have been previously detected in the developing brain of small, common laboratory mammals. Scattered glycogen-containing neurons also appear in the dorsal thalamus and basal forebrain. A conspicuous, often Golgi-like accumulation of glycogen has been found in neurons of the magnocellular and parvocellular hypothalamic systems. Together with available data on the metabolic rate of marsupials, our results suggest that the patterns of glycogen deposition may be common to several vertebrates and may be a constant although not exclusive property of cells with axonal endings outside the blood-brain barrier.

Astroglial differentiation in the opossum superior colliculus

Glial markers, namely, vimentin, glial fibrillary acidic protein (GFAP), and glycogen, as well as accumulation of axon-borne horseradish peroxidase (HRP), were used to visualize radial glial cells in the developing opossum superior colliculus (SC) and to follow changes in young astrocytes of the superficial layers. Vimentin, GFAP, and glycogen are relatively abundant in elements of the median ventricular formation (MVF), which persists at least as late as weaning time, i.e., postconception day 103, postnatal day 90 (PND90). Radial profiles and end-feet in the remaining collicular sectors (main radial system, MRS) are also vimentin-positive but show little or no glycogen or anti-GFAP staining. The numeric density of MRS profiles is very high at the final stages of neuronal migration (PND12) but falls to vestigial numbers by PND 56-60. Antivimentin staining and filling of MRS profiles by axon-borne HRP disappear in parallel. Before total regression of MRS profiles, young astrocytes of the superficial gray layer exhibit a transiently high GFAP expression that is not found in those of the subjacent layers. The results suggest that 1) radial glia at or near the collicular midline are well equipped for a mechanical supportive role, and their abundant glycogen accumulation may reflect their eventual transformation in cells with high glycolytic metabolism, including tanycytes; 2) in most collicular sectors, some radial glia cells persist for long periods after cessation of neuronal migration and may interact with afferent fibers coursing through the superficial neuropil; 3) radially oriented astrocytes of the superficial gray layer exhibit a transiently high GFAP expression that is temporally correlated with late transformations of the retinocollicular projections.