[Factors associated with prolonged hospital-stay after appendectomy during the SARS-CoV-2 pandemic]. / Faktory, svyazannye s dlitel'nym prebyvaniem v statsionare posle appendektomii vo vremya pandemii SARS-CoV-2.

OBJECTIVE: To determine the factors associated with prolonged hospital-stay after appendectomy in SARS-CoV-2 pandemic. MATERIAL AND METHODS: A retrospective observational cohort study included 420 patients after surgery for acute appendicitis between March 2019 and March 2020, April 2020 and April 2021. There were 336 patients before the SARS-COV-2 pandemic, and 84 ones underwent surgery during the pandemic. RESULTS: Incidence of prolonged hospital stay was 15% and 26%, respectively (RR 1.76). RR is more than 1 and assumes SARS-CoV-2 infection as a risk factor. CONCLUSION: There is an association between SARS-CoV-2 infection and prolonged hospital-stay after surgery for acute appendicitis (RR 1.76).

Differential permeability of the BBB in acute EAE: enhanced transport of TNT-alpha.

Impairment of the blood-brain barrier (BBB) in experimental autoimmune encephalomyelitis (EAE) has been frequently attributed to disruption, without much consideration of saturable transport processes. In mice with EAE, we studied the permeability of the BBB to radioactively labeled albumin and sucrose, markers of BBB disruption, and tumor necrosis factor-alpha (TNF-alpha), a cytokine transported across the BBB by a saturable system and thought to play a role in the pathogenesis of EAE. Permeation of the BBB was increased to all three substances during the acutely ill stage, was greatest in the lumbar spine, and returned to normal with recovery. The change in BBB permeability to sucrose was greater than to the larger albumin and is consistent with a partial disruption of the BBB. The enhanced permeability to TNF-alpha was comparable to that for sucrose, even though TNF-alpha is similar in size to albumin. This paradoxically high uptake of TNF-alpha could be explained by an enhancement of its endogenous saturable transport system. Thus the changes in BBB function during EAE extend beyond disruption to include changes in the saturable transport systems for substances involved in the disease process.

Blood-borne interleukin-1 receptor antagonist crosses the blood-brain barrier.

Recent work has shown that interleukin-1 alpha (IL-1 alpha) and IL-1 beta are transported from blood to brain across the blood-brain barrier by a saturable system. Here, we show that the endogenous IL-1 receptor antagonist (IL-1ra) radioactively labeled with either 125I or 35S is also transported across the blood-brain barrier by a saturable transport system. Between 0.33 and 0.65% of an intravenous dose of labeled IL-1ra entered each gram of brain. The three cytokines inhibited each other's transport in a way suggesting that their elevated blood levels would tend to favor the entry of IL-1 beta at the expense of IL-1 alpha. High performance liquid chromatography confirmed that radioactivity entering the brain represented intact cytokine. Recovery of radioactivity from cerebrospinal fluid, an area without blood vessels, and from the parenchymal fraction of the cortex, and area without circumventricular organs, after capillary depletion confirmed that blood-borne IL-1ra gained entry into the brain. The transport system for IL-1ra appeared to be linked to that for IL-1 alpha and IL-1 beta, but was not affected by IL-2, IL-6, TNF alpha, or MIP-1 alpha. The results show that IL-1ra circulating in the blood can cross the blood-brain barrier to enter the central nervous system.

Penetration of interleukin-6 across the murine blood-brain barrier.

Interleukin-6 (IL-6) can alter brain function after peripheral administration, suggesting that it, like IL-1 alpha, IL-1 beta and TNF-alpha, might be able to cross the blood-brain barrier (BBB). We used multiple-time regression analysis to measure the unidirectional influx constant (Ki) into brain of radioactively labeled murine and human IL-6 given i.v. Ki values ranged from 3.05 to 4.54 (10(-4)) ml/g/min and were inhibited by unlabeled IL-6 but not IL-1 alpha or TNF-alpha, showing that the transport system for IL-6 is distinct from those for IL-1 alpha and TNF-alpha. Approximately 0.2% of the dose injected i.v. entered each gram of brain. The capillary depletion method showed that most of the IL-6 taken up by brain entered the parenchyma. However, only approximately 16% of the radioactivity recovered eluted as intact I-IL-6 in brain and approximately 50% in CSF after chromatographic separation by HPLC/Sephadex. The efflux rate for IL-6 injected into the lateral ventricle of the brain suggests that it enters the blood with the reabsorption of CSF. These results suggest that blood-borne IL-6 can reach sites behind the BBB, but that susceptibility to enzymatic degradation may limit contact time within the CNS.

Interleukin-1 alpha in blood has direct access to cortical brain cells.

Interleukin-1 alpha (IL-1 alpha), an immunoregulatory protein secreted by the peripheral immune system, affects the central nervous system (CNS). IL-1 alpha could directly enter the parenchyma of the brain in intact form to alter brain function, or it could be blocked or sequestered by the capillary bed comprising the blood-brain barrier (BBB) that normally retards entry of circulating proteins to the brain and cerebrospinal fluid (CSF). We show here by use of the selective interleukin receptor antagonist (IL-1ra), capillary depletion method, high performance liquid chromatography (HPLC) and saturation with unlabeled IL-1 alpha that radioactively labeled IL-1 alpha injected iv directly enters the CNS in intact form. This also occurs in the brain cortex, an area devoid of circumventricular organs (CVOs), and in the CSF, an area devoid of capillaries. Capillaries can also sequester IL-1 alpha in a saturable manner, suggesting that they may be the site for the carrier-mediated entry of IL-1 alpha into the CNS. Thus, the results show that circulating IL-1 alpha has direct access to cortical brain cells behind the BBB through a saturable transport system that provides a major pathway by which the brain and immune system interact.

Murine tumor necrosis factor alpha is transported from blood to brain in the mouse.

The cytokines are important components of the brain-immune axis. Recent work has shown that [125I]IL-1 alpha and [125I]IL-1 beta are transported from the blood into the brain by a saturable system. Here we show that murine tumor necrosis factor alpha (mTNF alpha) labeled with 125I (I-mTNF alpha) crosses the blood-brain barrier (BBB) after i.v. injection by a transport system different from that for the interleukins. Self inhibition with mTNF alpha showed that this transport system was saturable, and lack of inhibition by IL-1 alpha, IL-1 beta, IL-6, or MIP-1 alpha showed selectivity of the system. High performance liquid chromatography (HPLC) of the radioactivity recovered from brain and from cerebrospinal fluid after the i.v. injection of I-mTNF alpha showed that the cytokine crossed the BBB largely in intact form. Capillary depletion showed that the accumulation of I-mTNF alpha in the cerebral cortex was due to passage across the BBB rather than to sequestration by capillaries. Transport rate was not changed by acute treatment with the neurotoxin aluminium or by acute and chronic treatment with the cationic chelator deferoxamine, but it was more than three times faster in neonatal rats. Efflux of I-mTNF alpha from the brain was slower than would have been predicted based on reabsorption of cerebrospinal fluid, suggesting that TNF alpha is sequestered by the brain. The BBB was not disrupted by up to 50 micrograms kg-1 of mTNF alpha i.v. in either adult mice or neonatal rats as assessed by the BBB's impermeability to radioactively labeled albumin.(ABSTRACT TRUNCATED AT 250 WORDS)