Effect of the SARS-CoV-2 pandemic on colorectal cancer diagnosis and prognosis

BACKGROUND AND STUDY AIMS

Our aim was to determine the impact of the SARS-CoV-2 pandemic on the diagnosis and prognosis of colorectal cancer (CRC).

PATIENTS AND METHODS

This prospective cohort study included individuals diagnosed with CRC between March 13, 2019 and June 20, 2021 across 21 Spanish hospitals. Two time periods were compared: prepandemic (from March 13, 2019 to March 13, 2020) and pandemic (from March 14, 2020 to June 20, 2021, lockdown period and 1 year after lockdown).

RESULTS

We observed a 46.9% decrease in the number of CRC diagnoses (95% confidence interval (CI): 45.1%-48.7%) during the lockdown and 29.7% decrease (95% CI: 28.1%-31.4%) in the year after the lockdown. The proportion of patients diagnosed at stage I significantly decreased during the pandemic (21.7% vs. 19.0%; p = 0.025). Centers that applied universal preprocedure SARS-CoV-2 PCR testing experienced a higher reduction in the number of colonoscopies performed during the pandemic post-lockdown (34.0% reduction; 95% CI: 33.6%-34.4% vs. 13.7; 95% CI: 13.4%-13.9%) and in the number of CRCs diagnosed (34.1% reduction; 95% CI: 31.4%-36.8% vs. 26.7%; 95% CI: 24.6%-28.8%). Curative treatment was received by 87.5% of patients diagnosed with rectal cancer prepandemic and 80.7% of patients during the pandemic post-lockdown period (p = 0.002).

CONCLUSIONS

The COVID-19 pandemic has led to a decrease in the number of diagnosed CRC cases and in the proportion of stage I CRC. The reduction in the number of colonoscopies and CRC diagnoses was higher in centers that applied universal SARS-CoV-2 PCR screening before colonoscopy. In addition, the COVID-19 pandemic has affected curative treatment of rectal cancers.

Distribution of diacylglycerol lipase alpha, an endocannabinoid synthesizing enzyme, in the rat forebrain

1,2-diacylglycerol lipase alpha (DAGLα) is responsible for the biosynthesis and release of 2-arachidonoyl-glycerol (2-AG), the most abundant endocannabinoid in the brain. Although its expression has been detected in discrete regions, we showed here an integrated description of the distribution of DAGLα mRNA and protein in the rat forebrain using in situ hybridization histochemistry and immunohistochemistry. As novelty, we described the distribution of DAGLα protein expression in the olfactory system, the rostral migratory stream, neocortex, septum, thalamus, and hypothalamus. Similar DAGLα immunostaining pattern was also found in the brain of wild-type, but not of DAGLα knockout mice. Immunohistochemical data were correlated by the identification of DAGLα mRNA expression, for instance, in the somata of specific cells in olfactory structures, rostral migratory stream and neocortex, cells in some septal-basal-amygdaloid areas and the medial habenula, and magnocellular cells of the paraventricular hypothalamic nucleus. This widespread neuronal distribution of DAGLα is consistent with multiple roles for endocannabinoids in synaptic plasticity, including presynaptic inhibition of neurotransmitter release. We discuss our comparative analysis of the forebrain expression patterns of DAGLα and other components of the endocannabinoid signaling system, including the CB(1) receptor, monoacylglyceride lipase (MAGL), and fatty acid amide hydrolase (FAAH), providing some insight into the potential physiological and behavioral roles of this system.

Effect of injection of beta-carotene or vitamin E and selenium on fertility of lactating dairy cows

Experiments tested whether supplemental antioxidants improved fertility. To test effects of beta-carotene, cows in a hot environment were injected with prostaglandin F2 alpha (PGF2 alpha) and were given 3 injections, i.m., of 800 mg beta-carotene or saline at Days -6 and -3 before the anticipated date of insemination and at insemination (n = 37-41 inseminated cows/group). There was no effect of beta-carotene on the proportion of cows detected in estrus following PGF2 alpha, timing of estrus after PGF2 alpha injection or pregnancy rate in inseminated cows. In a second trial, cows in a temperate climate received intramuscular injections of vitamin E (500 mg) and selenium (50 mg) at 30 d post partum (n = 97) or were untreated controls (n = 89). Treatment did not affect interval from calving to first insemination or the proportion of cows pregnant at first service, but it increased the pregnancy rate at second service (69.8 vs 52.1%; P = 0.07) and reduced services per conception (1.7 vs 2.0; P < 0.05) and interval from calving to conception (84.6 vs 98.1; P < 0.05). Thus, injection of vitamin E and selenium increased fertility in cattle that did not become pregnant at first service.

Effect of prepartum injection of vitamin E and selenium on postpartum reproductive function of dairy cattle

A total of 198 cows were randomly assigned to treatment with a single intramuscular injection of 10 ml of a preparation containing vitamin E and selenium or placebo 3 wk before expected parturition. Incidence of retained fetal membranes was 3.0% for the treated group and 10.1% for the control group (P=0.06). Administration of MU-SE also increased the percentage of cows pregnant to the first service (41.2 vs 25.3%; P=0.02), reduced the number of services per conception (2.3 vs 2.8; P=0.03), and reduced the interval from calving to conception (121 vs 141 days; P=0.06). The effect of MU-SE on fertility was apparent in cows with and without retained fetal membranes. There was no effect of MU-SE on the interval from calving to the first estrus. In conclusion, prepartum supplementation with vitamin E and selenium can decrease the incidence of retained fetal membranes, increase pregnancy rates and, thereby, reduce the interval from calving to conception in lactating dairy cows.

Sodium and rubidium fluxes in rat red blood cells

1. The Na content of rat red cells was found to be 4.40 m-mole/l. cells. When incubated in K(Rb)-free Na this value was doubled in 1 hr, whereas in K(Rb)-free choline it was reduced to about 35% in the same period of time.2. In cells with elevated Na (13.70 m-mole/l.) the activation curve of Rb influx by external Rb reached the same V(max) in sodium as in choline. The shape of the curve was sigmoid in the first case (K(m) about 1.05 mM) and hyperbolic in the second (K(m) about 0.20 mM).3. The activation curve of rubidium influx by internal sodium was linear at least up to 12 m-mole/l. cells with a slope of 0.84. From this concentration it could increase more steeply, though the data is insufficient to assure it.4. In normal cells the efflux of Na in K(Rb)-free Na Ringer was 5.64 m-mole/l. cells. hr, and it was reduced to 4.32 m-mole by 10(-4)M ouabain. This was accompanied by a reduction of Na influx by 4.14 m-mole, representing then a Na-Na ouabain-sensitive exchange mechanism.5. At a concentration of 5 mM, external Rb increased Na efflux in 2.32 m-mole/l. cells. hr above the K(Rb)-free levels, and reduced Na influx by 2.13 m-mole.6. It is proposed that the Na pump is able to operate even in the absence of external K(Rb), though at reduced rate and on a Na-Na exchange basis (Na is the only monovalent cation in the bathing solution). External K(Rb) would have two actions: to increase the rate of shuttling of the carrier (catalytic effect) and to switch the Na-Na to a Na-K(Rb) exchange.7. These results raise a question of the real significance of the Na/K(Rb) ;coupling' ratio and the K-free effect on the Na pump mechanism.

Rubidium, sodium and ouabain interactions on the influx of rubidium in rat red blood cells

1. The activation curve of rubidium influx by external rubidium in rat red cells showed an inflexion at a concentration around 0.2 mM. This inflexion point was displaced to the right by ouabain.2. The removal of sodium from the external solution changed the characteristics of the activation curve of rubidium influx. At external rubidium below 0.5 mM the uptake increased whereas above that concentration there was marked reduction. Thus the sodium-free effect on rubidium uptake is dependent on the external rubidium concentration.3. With 0.25 mM rubidium, the relationship between increase of rubidium influx and reduction of external sodium followed a more or less exponential function. All the increment was ouabain-sensitive.4. With a rubidium concentration above 0.5 mM the reduction of the rubidium uptake, as sodium was removed, followed curves of complex shape. With 10 mM rubidium, when sodium was reduced from 5 mM to zero, there was an increase instead of a further reduction. These results suggest interactions of several effects.5. The ouabain sensitivity of the rubidium influx in rat red cells is smaller than in other systems studied up to now. The dose-response curve was shifted to the right as the rubidium concentration increased and a plateau was obtained with rubidium only below 1 mM at 10(-5)M ouabain. When plotted as a percentage of the maximal inhibition the points fell into the theoretical curve following a simple one reactant/one site reaction.6. Ouabain inhibition seems to be a complex function of at least three variables: the concentration of the glycoside, the concentration of sodium and the concentration of rubidium. When sodium was absent, 10 muM rubidium was able to prevent, to a great extent, the inhibition produced by 10(-5) and 10(-4)M ouabain.