Clustering and multiple-spreading events of nosocomial severe acute respiratory syndrome coronavirus 2 infection

Background

There is growing evidence that super-spreading events (SSEs) and multiple-spreading events (MSEs) are a characteristic feature of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, data regarding the possibility of SSEs or MSEs in healthcare settings are limited.

Methods

This study was performed at a tertiary-care hospital in Korea. We analysed the nosocomial COVID-19 cases that occurred in healthcare workers and inpatients and their caregivers between January and 20^th December 2020. Cases with two to four secondary cases were defined as MSEs and those with five or more secondary cases as SSEs.

Findings

We identified 21 nosocomial events (single-case events, N = 12 (57%); MSE + SSE, N = 9 (43%)) involving 65 individuals with COVID-19. Of these 65 individuals, 21 (32%) were infectors. The infectors tended to have a longer duration between symptom onset and diagnostic confirmation than did the non-infectors (median two days vs zero days, P=0.08). Importantly, 12 (18%) individuals were responsible for MSEs and one (2%) for an SSE, which collectively generated 35 (54%) secondary cases.

Conclusion

In a hospital with thorough infection-control measures, approximately 70% of the nosocomial cases of COVID-19 did not generate secondary cases, and one-fifth of the infectors were responsible for SSEs and MSEs, which accounted for approximately half of the total cases. Early case identification, isolation, and extensive contact tracing are important for the prevention of transmission and SSEs.

Differences in the glucose-lowering efficacy of dipeptidyl peptidase-4 inhibitors between Asians and non-Asians: a systematic review and meta-analysis

AIMS/HYPOTHESIS

The aim of this work was to compare the glucose-lowering efficacy of dipeptidyl peptidase-4 (DPP-4) inhibitors between Asian and non-Asian patients with type 2 diabetes.

METHODS

We searched MEDLINE, EMBASE, LILACS, CENTRAL, ClinicalTrials.gov and conference proceedings. Studies were eligible if they were randomised controlled trials with a treatment duration of at least 12 weeks, compared a DPP-4 inhibitor with a placebo as either monotherapy or oral combination therapy, had information on ethnicity and HbA1c values and were published or described in English. A systematic review and meta-analysis with a meta-regression analysis was conducted.

RESULTS

Among 809 potentially relevant studies, 55 trials were included. A meta-analysis revealed that DPP-4 inhibitors lowered HbA1c to a greater extent in studies with ≥50% Asian participants (weighted mean difference [WMD] -0.92%; 95% CI -1.03, -0.82) than in studies with <50% Asian participants (WMD -0.65%; 95% CI -0.69, -0.60). The between-group difference was -0.26% (95% CI -0.36, -0.17, p < 0.001). The baseline BMI significantly correlated with the HbA1c-lowering efficacy of DPP-4 inhibitors. The RR of achieving the goal of HbA1c <7.0% (53.0 mmol/mol) was higher in studies with ≥50% Asian participants (3.4 [95% CI 2.6, 4.7] vs 1.9 [95% CI 1.8, 2.0]). The fasting plasma glucose-lowering efficacy was higher with monotherapy in the Asian-dominant studies, but the postprandial glucose-lowering efficacy and changes in body weight were comparable between the two groups.

CONCLUSIONS/INTERPRETATION

DPP-4 inhibitors exhibit a better glucose-lowering efficacy in Asians than in other ethnic groups; this requires further investigation to understand the underlying mechanism, particularly in relation to BMI.

Association of genetic variation in FTO with risk of obesity and type 2 diabetes with data from 96,551 East and South Asians

AIMS/HYPOTHESIS

FTO harbours the strongest known obesity-susceptibility locus in Europeans. While there is growing evidence for a role for FTO in obesity risk in Asians, its association with type 2 diabetes, independently of BMI, remains inconsistent. To test whether there is an association of the FTO locus with obesity and type 2 diabetes, we conducted a meta-analysis of 32 populations including 96,551 East and South Asians.

METHODS

All studies published on the association between FTO-rs9939609 (or proxy [r (2) > 0.98]) and BMI, obesity or type 2 diabetes in East or South Asians were invited. Each study group analysed their data according to a standardised analysis plan. Association with type 2 diabetes was also adjusted for BMI. Random-effects meta-analyses were performed to pool all effect sizes.

RESULTS

The FTO-rs9939609 minor allele increased risk of obesity by 1.25-fold/allele (p = 9.0 × 10(-19)), overweight by 1.13-fold/allele (p = 1.0 × 10(-11)) and type 2 diabetes by 1.15-fold/allele (p = 5.5 × 10(-8)). The association with type 2 diabetes was attenuated after adjustment for BMI (OR 1.10-fold/allele, p = 6.6 × 10(-5)). The FTO-rs9939609 minor allele increased BMI by 0.26 kg/m(2) per allele (p = 2.8 × 10(-17)), WHR by 0.003/allele (p = 1.2 × 10(-6)), and body fat percentage by 0.31%/allele (p = 0.0005). Associations were similar using dominant models. While the minor allele is less common in East Asians (12-20%) than South Asians (30-33%), the effect of FTO variation on obesity-related traits and type 2 diabetes was similar in the two populations.

CONCLUSIONS/INTERPRETATION

FTO is associated with increased risk of obesity and type 2 diabetes, with effect sizes similar in East and South Asians and similar to those observed in Europeans. Furthermore, FTO is also associated with type 2 diabetes independently of BMI.

Altered cardiovascular responses to tracheal intubation in patients with complete spinal cord injury: relation to time course and affected level

BACKGROUND

We determined cardiovascular responses to tracheal intubation in relation to the time since injury in patients with different levels of spinal cord injury.

METHODS

Two hundred and fourteen patients with complete cord injury were studied. They were either quadriplegics (>C7, n=71) or paraplegics (<T5, n=143), and were subdivided into six groups each according to the time since injury: <4 week (acute), 4 week-1 yr, 1-5, 5-10, 10-20, and >20 yr. Twenty patients with no cord injury served as controls. Systolic arterial pressure (SAP), heart rate (HR), and plasma catecholamine concentrations were determined.

RESULTS

Intubation did not affect SAP in the quadriplegics regardless of the time post-injury, but it significantly increased SAP in all paraplegics. Moreover, the pressor response was enhanced in the paraplegics who were 10 yr or more since injury (P<0.05). HR increased significantly in all groups; the magnitude of the increase was less only in acute quadriplegics compared with controls. Plasma concentrations of norepinephrine increased in every group except for the quadriplegics within 4 weeks of injury. The maximum increases in SAP, HR, and norepinephrine from awake baseline values were smaller in the quadriplegics than in the paraplegics (P<0.01).

CONCLUSIONS

The cardiovascular and catecholamine responses to intubation change as a function of the time elapsed and the level of the cord injury. In this study, the pressor response to tracheal intubation was abolished in the quadriplegics but not in paraplegics; indeed, it was enhanced at 10 yr or more since injury in this group.

Association of polymorphisms in the insulin-degrading enzyme gene with type 2 diabetes in the Korean population

Insulin-degrading enzyme (IDE) is a metalloproteinase which degrades insulin and terminates its action. Homologous deletion of IDE gene resulted in hyperinsulinemia and glucose intolerance in a rat model of type 2 diabetes mellitus. Several genetic association studies examined IDE as a susceptibility gene for type 2 diabetes in European descents. Here we investigated the genetic association of IDE polymorphisms with the risk of type 2 diabetes and its related phenotypes in the Korean population. Among six single nucleotide polymorphisms analyzed, g.-179T>C (OR=1.73, P=0.04), and g.IVS18+99G>A (OR=1.23, P=0.02) revealed borderline association with increased risk of type 2 diabetes. Combining our results with previous data obtained from the European population, g.-179T>C (OR=1.11, P=0.03), and g.IVS24-64A>T (OR=1.18, P=0.005) showed significant association with type 2 diabetes. Haplotype consisting of common alleles of the six polymorphisms was associated with decreased risk of type 2 diabetes (OR=0.82, P=0.02). However, none of the polymorphisms was significantly associated with metabolic phenotypes. We can conclude that variations in IDE might contribute to diabetes susceptibility in the Korean population.

Effects of intracoronary calcium chloride on regional oxygen balance and mechanical function in normal and stunned myocardium in dogs

BACKGROUND

Brief myocardial ischaemia has been demonstrated to result in mechanical and coronary endothelial dysfunction, in which calcium may play a role. We examined whether the mechanical and vascular responses to calcium are altered in postischaemic, reperfused myocardium.

METHODS

Regional myocardial oxygen consumption (MVO2), mechanical function and coronary blood flow (CBF) in response to calcium chloride (0.10, 0.25, 0.50 and 0.75 mg ml(-1) of CBF) directly infused into the left anterior descending (LAD) artery were determined before (normal) and 30 min after a 15-min-period of LAD occlusion (stunned) in an open-chest canine model. Percentage segment shortening (%SS) and percentage postsystolic shortening (%PSS) in the LAD territory were determined using ultrasonic crystals and CBF using a Doppler transducer. Myocardial extraction of oxygen (EO2) and lactate (Elac) was calculated.

RESULTS

The infusion of calcium chloride resulted in dose-dependent increases in %SS and MVO2 but did not affect %PSS in normal myocardium. These changes were accompanied by parallel increases in CBF, resulting in no change in EO2. In stunned myocardium, the responses to calcium chloride were not significantly altered, with the exception of a reduction in %PSS. However, ischaemia and reperfusion itself significantly reduced %SS and Elac and increased %PSS.

CONCLUSIONS

These data suggest that calcium chloride improves regional systolic and diastolic function both in normal and stunned myocardium. Calcium chloride is unlikely to cause direct coronary vasoconstriction or to deteriorate regional mechanical function in postischaemic myocardium.

The regulation of ornithine decarboxylase gene expression by sucrose and small upstream open reading frame in tomato (Lycopersicon esculentum Mill)

We identified a near-full-length cDNA clone encoding ornithine decarboxylase (ODC) from tomato (Lycopersicon esculentum Mill). It contained a small upstream open reading frame (uORF) within its 5' untranslated region. An in vitro translation assay demonstrated that the uORF repressed expression of downstream ORF. Neither nucleotide nor predicted peptide sequence of the uORF was responsible for the repression. The presence of upstream AUG codon was shown to be responsible. ODC expression appeared to be organ specific. The ODC gene was expressed in roots, hypocotyls and sink leaves but not in source leaves. ODC transcripts were observed in apical meristem of primary roots, and were distributed in cells of cortex layer preferentially. ODC expression responded immediately to sucrose availability via the sucrose-specific pathway independent of hexokinase. Sucrose induction of ODC gene was seen in roots, hypocotyls and flowers but not in mature leaves. Moreover, only the root apical meristem responded to sucrose availability. These observations indicate that the spatial pattern of ODC expression is closely associated with cell proliferation and that sucrose sensing plays a major role in the spatial pattern of ODC expression. Also, the differential regulation of ODC and arginine decarboxylase gene expression by factors modulating plant growth suggests that they would have different physiological roles in plant development.

Intracoronary propofol attenuates myocardial but not coronary endothelial dysfunction after brief ischaemia and reperfusion in dogs

We have investigated the effects of propofol on recovery of regional mechanical and coronary endothelial function and on lipid peroxidation in post-ischaemic myocardium in dogs. The animals were assessed for 180 min during reperfusion after 15-min of occlusion of the left anterior descending coronary artery (LAD). They were treated with intracoronary (i.c.) propofol 5 or 20 micrograms/ml of coronary flow or vehicle (control group) for 60 min, beginning 30 min before LAD occlusion. Propofol significantly enhanced recovery of regional contractile function (70% and 81% of baseline segment shortening in the propofol 5 and 20 micrograms ml-1 groups, respectively, compared with 51% in controls at 3 h of reperfusion). However, LAD flow responses to i.c. acetylcholine were similarly attenuated regardless of treatment with propofol throughout reperfusion. The increase in malondialdehyde induced by ischaemia-reperfusion was significantly suppressed by both doses of propofol. These results demonstrated that in vivo, propofol ameliorated dysfunction of the myocardium but not of the coronary endothelium resulting from brief ischaemia and reperfusion; the protection may be related, at least in part, to its ability to reduce lipid peroxidation.

The requirements for Ca2+, protein phosphorylation, and dephosphorylation for ethylene signal transduction in Pisum sativum L

The role of Ca2+ and protein phosphorylation in the transduction of the ethylene signal resulting in induction of 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase has been studied in peas (Pisum sativum L.) by a pharmacological approach. 2,5-Norbornadiene (NBD) and aminoethoxyvinylglycine (AVG) reduced the basal level of ACC oxidase transcript and its enzyme activity. Only NBD was shown to inhibit the ethylene response, the accumulation of ACC oxidase transcript and the stimulation of its enzyme activity. Ethylene influenced 45Ca2+ influx into the segment tissues from pea epicotyls, and ethylene glycol-bis(beta-aminoethyl ether)N,N,N'N'-tetraacetic acid (EGTA) a Ca2+ chelator, inhibited the ethylene response. Ca2+ depletion by pretreatment with EGTA also blocked the ethylene response, which almost completely recovered when Ca2+ was added exogenously after Ca2+ depletion. Ca2+ channel blockers, verapamil, and LaCl3, used to certify the role of extracellular Ca2+, all inhibited the ethylene response. A protein kinase inhibitor, 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H-7), and protein phosphatase inhibitors, vanadate and okadaic acid, also inhibited the ethylene response. The results of the present study suggest that Ca2+ influx from the extracellular space, protein phosphorylation, and dephosphorylation are required for the induction of ACC oxidase by ethylene.