Age-associated systemic factors change central and peripheral immunity in adult male mice

Aging coincides with major changes in brain immunity that aid in a decline in neuronal function. Here, we postulate that systemic, pro-aging factors contribute to immunological changes that occur within the brain during aging. To investigate this hypothesis, we comprehensively characterized the central and peripheral immune landscape of 20-month-old male mice using cytometry by time-of-flight (CyTOF) and investigated the role of age-associated circulating factors. We found that CD8+ T cells expressing programmed cell death protein 1 (PD1) and tissue-resident memory CD8+ T cells accumulated in the aged brain while levels of memory T cells rose in the periphery. Injections of plasma derived from 20-month-old mice into 5-month-old receiving mice decreased the frequency of splenic and circulating naïve T cells, increased memory CD8+ T cells, and non-classical, patrolling monocytes in the spleen, and elevated levels of regulatory T cells and non-classical monocytes in the blood. Notably, CD8+ T cells accumulated within white matter areas of plasma-treated mice, which coincided with the expression of vascular cell adhesion molecule 1 (VCAM-1), a mediator of immune cell trafficking, on the brain vasculature. Taken together, we here describe age-related immune cell changes in the mouse brain and circulation and show that age-associated systemic factors induce the expansion of CD8+ T cells in the aged brain.

Ursodeoxycholic acid for the prevention of symptomatic gallstone disease after bariatric surgery (UPGRADE): a multicentre, double-blind, randomised, placebo-controlled superiority trial

BACKGROUND

Rapid weight loss is a major risk factor for the formation of cholesterol gallstones. Consequently, patients with morbid obesity undergoing bariatric surgery frequently develop symptomatic gallstone disease. This trial assessed the efficacy of ursodeoxycholic acid versus placebo for the prevention of symptomatic gallstone disease after bariatric surgery.

METHODS

This multicentre, double-blind, randomised, placebo-controlled superiority trial enrolled patients with an intact gallbladder scheduled for laparoscopic Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy in three hospitals in the Netherlands. Patients were randomly assigned (1:1) by a web-based randomisation module to receive 900 mg ursodeoxycholic acid daily for 6 months or matched placebo. Randomisation was stratified by the presence of asymptomatic gallstones at baseline and type of surgery. Patients, clinicians, and study staff were masked to treatment allocation. The primary endpoint was symptomatic gallstone disease within 24 months, assessed in the modified intention-to-treat population (all randomly assigned eligible patients with any post-randomisation measurement). Prespecified subgroup analyses were done based on the stratification groups. Safety was assessed in all patients who took at least one dose of the study drug. This trial is registered with the Netherlands Trial Register, NL5954.

FINDINGS

Between Jan 11, 2017, and Oct 22, 2018, 985 patients were randomly assigned to receive either ursodeoxycholic acid (n=492) or placebo (n=493). 967 patients were included in the modified intention-to-treat population, of whom 959 had data available for primary endpoint assessment. 189 (20%) patients had asymptomatic gallstones at baseline and 78 (8%) received a sleeve gastrectomy. Symptomatic gallstone disease occurred in 31 (6·5%) of 475 patients in the ursodeoxycholic acid group and in 47 (9·7%) of 484 patients in the placebo group (relative risk 0·67, 95% CI 0·43-1·04, p=0·071). Logistic regression showed a significant interaction between ursodeoxycholic acid and the presence of asymptomatic gallstones at baseline (p=0·046), with an effect of ursodeoxycholic acid in patients without (0·47, 0·27-0·84, p=0·0081), and no effect in patients with asymptomatic gallstones at baseline (1·22, 0·61-2·47, p=0·57). The effect was stronger in patients without gallstones at baseline undergoing RYGB (0·37, 0·20-0·71, p=0·0016), whereas the subgroup of patients undergoing sleeve gastrectomy was too small to draw clear conclusions. Adverse events were rare. In the ursodeoxycholic acid group, diarrhoea occurred in four (0·9%) of 444 patients and skin rash in two (0·5%) patients. In the placebo group, diarrhoea occurred in two (0·4%) of 453 patients and skin rash in two (0·4%) patients. The total number of serious adverse events did not significantly differ between the trial groups (75 [17%] in 444 patients in the ursodeoxycholic acid group and 102 [23%] in 453 patients in the placebo group). The most common serious adverse events were abdominal pain and internal hernia. No serious adverse event was attributed to the study drug.

INTERPRETATION

Ursodeoxycholic acid prophylaxis did not significantly reduce the occurrence of symptomatic gallstone disease in all patients after bariatric surgery. In patients without gallstones before RYGB surgery, ursodeoxycholic acid treatment reduced the occurrence of symptomatic gallstone disease compared with placebo. Further research is needed to assess the efficacy of ursodeoxycholic acid after sleeve gastrectomy.

FUNDING

The Netherlands Organization for Health Research and Development, Zambon Netherlands BV, Foundation for Clinical Research of the Slotervaart Hospital, the Spaarne Gasthuis Academy, and Amsterdam Gastroenterology Endocrinology Metabolism.

Circadian glucocorticoid oscillations preserve a population of adult hippocampal neural stem cells in the aging brain

A decrease in adult hippocampal neurogenesis has been linked to age-related cognitive impairment. However, the mechanisms involved in this age-related reduction remain elusive. Glucocorticoid hormones (GC) are important regulators of neural stem/precursor cells (NSPC) proliferation. GC are released from the adrenal glands in ultradian secretory pulses that generate characteristic circadian oscillations. Here, we investigated the hypothesis that GC oscillations prevent NSPC activation and preserve a quiescent NSPC pool in the aging hippocampus. We found that hippocampal NSPC populations lacking expression of the glucocorticoid receptor (GR) decayed exponentially with age, while GR-positive populations decayed linearly and predominated in the hippocampus from middle age onwards. Importantly, GC oscillations controlled NSPC activation and GR knockdown reactivated NSPC proliferation in aged mice. When modeled in primary hippocampal NSPC cultures, GC oscillations control cell cycle progression and induce specific genome-wide DNA methylation profiles. GC oscillations induced lasting changes in the methylation state of a group of gene promoters associated with cell cycle regulation and the canonical Wnt signaling pathway. Finally, in a mouse model of accelerated aging, we show that disruption of GC oscillations induces lasting changes in dendritic complexity, spine numbers and morphology of newborn granule neurons. Together, these results indicate that GC oscillations preserve a population of GR-expressing NSPC during aging, preventing their activation possibly by epigenetic programming through methylation of specific gene promoters. Our observations suggest a novel mechanism mediated by GC that controls NSPC proliferation and preserves a dormant NSPC pool, possibly contributing to a neuroplasticity reserve in the aging brain.

The Use of Intraperitoneal Bupivacaine in Laparoscopic Roux-en-Y Gastric Bypass: a Double-blind, Randomized Controlled Trial

BACKGROUND

Several studies have shown a reduction in postoperative pain and length of hospital stay when using intraperitoneal local anesthetics during laparoscopic surgery. In morbidly obese patients, respiratory depression due to opioid use is a serious side effect. Any different type of analgesia is therefore clinically relevant.

OBJECTIVE

To assess the effect of intraperitoneal bupivacaine on postoperative pain after laparoscopic Roux-en-Y gastric bypass (LRYGB).

METHODS

Between March and November 2017, 130 patients were included and randomly assigned to receive 20 ml or 0 ml of 2.5% bupivacaine hydrochloride sprayed onto the diaphragm. Pain scores for abdominal and shoulder pain were conducted using the visual analogue scale (VAS) for pain score at 0, 1, 6, and 24 h postoperatively. The length of hospital stay and use of analgesics was recorded in digital patient records. The primary outcome is the pain scores and the secondary outcomes are postoperative use of opioids or antiemetics and length of hospital stay.

RESULTS

The study and control group contained respectively 66 and 61 patients. Patient characteristics were equal in both groups (p < 0.05), except for age. No significant reduction of postoperative pain or opioid use was seen with the use of intraperitoneal bupivacaine. There was also no significant reduction in the use of antiemetics and length of hospital stay.

CONCLUSION

The use of intraperitoneal bupivacaine in LRYGB does not show a statistically significant reduction in postoperative pain or postoperative opioid use. Therefore, using intraperitoneal bupivacaine has no clinical relevance and should no longer be used in LRYGB.

Effect of the factor V Leiden mutation on the incidence and outcome of severe infection and sepsis

Activation of coagulation frequently occurs in severe infection and sepsis and may contribute to the development of multiple organ dysfunction. Factor V Leiden is a relatively common mutation resulting in a mild prohaemostatic state and consequently with an increased tendency to develop thrombosis. Hypothetically, patients with factor V Leiden may suffer from more severe coagulopathy in case of severe infection or sepsis. Aggravation of the procoagulant state in sepsis may subsequently result in more severe organ dysfunction and an increased risk of death. Here we discuss the experimental and clinical evidence regarding the relationship between the presence of a factor V Leiden mutation and the incidence and outcome of sepsis.

Measurement of the reduced scattering coefficient of turbid media using single fiber reflectance spectroscopy: fiber diameter and phase function dependence

This paper presents a relationship between the intensity collected by a single fiber reflectance device (R(SF)) and the fiber diameter (d(fib)) and the reduced scattering coefficient ( μs') and phase function (p(θ)) of a turbid medium. Monte Carlo simulations are used to identify and model a relationship between R(SF) and dimensionless scattering ( μs'dfib). For μs'dfib > 10 we find that R(SF) is insensitive to p(θ). A solid optical phantom is constructed with μs' ≈ 220 mm-1 and is used to convert R(SF) of any turbid medium to an absolute scale. This calibrated technique provides accurate estimates of μs' over a wide range ([0.05 - 8] mm(-1)) for a range of d(fib) ([0.2 - 1] mm).

Factor V Leiden mutation does not affect coagulopathy or outcome in lethal H1N1 influenza

Influenza A is a major cause of mortality. Knowledge on coagulation activation in influenza infection is limited. The factor V Leiden (FVL) mutation is possibly subject to positive selection pressure. It is unknown whether this mutation impacts on the outcome of severe influenza. In the present study, the effect of lethal influenza on pulmonary and systemic coagulation activation and whether or not FVL mutation alters coagulation activation in and the course of lethal influenza, was determined. Wild-type mice, and mice heterozygous or homozygous for FVL were infected intranasally with a lethal dose of H1N1 (haemagglutinin 1 and neuraminidase 1) influenza A. Mice were sacrificed after 48 or 96 h for determination of coagulation activation, histopathology, pulmonary inflammatory parameters and viral load, or were observed in a survival study. Extensive local and systemic coagulation activation during lethal influenza was demonstrated by increased lung and plasma levels of thrombin-antithrombin complexes and fibrin degradation products, and by pulmonary fibrin deposition. FVL mutation did not influence the procoagulant response, lung histopathology or survival. FVL mice demonstrated elevated viral loads 48 h after infection. In conclusion, coagulation is activated locally and systemically during lethal murine influenza A infection. The FVL mutation does not influence coagulation activation, lung inflammation or survival in lethal influenza A.

Natural anticoagulants limit lipopolysaccharide-induced pulmonary coagulation but not inflammation

Pulmonary coagulopathy and hyperinflammation may contribute to an adverse outcome in sepsis. The present study determines the effects of natural inhibitors of coagulation on bronchoalveolar haemostasis and inflammation in a rat model of endotoxaemia. Male Sprague-Dawley rats were randomised to treatment with normal saline, recombinant human activated protein C (APC), plasma-derived antithrombin (AT), recombinant human tissue factor pathway inhibitor (TFPI), heparin or recombinant tissue plasminogen activator (tPA). Rats were intravenously injected with lipopolysaccharide (LPS), which induced a systemic inflammatory response and pulmonary inflammation. Blood and bronchoalveolar lavage were obtained at 4 and 16 h after LPS injection, and markers of coagulation and inflammation were measured. LPS injection caused an increase in the levels of thrombin-AT complexes, whereas plasminogen activator activity was attenuated, both systemically and within the bronchoalveolar compartment. Administration of APC, AT and TFPI significantly limited LPS-induced generation of thrombin-AT complexes in the lungs, and tPA stimulated pulmonary fibrinolytic activity. However, none of the agents had significant effects on the production of pulmonary cytokines, chemokines, neutrophil influx and myeloperoxidase activity. Natural inhibitors of coagulation prevent bronchoalveolar activation of coagulation, but do not induce major alterations of the pulmonary inflammatory response in rat endotoxaemia.

Brain atrophy and lesion load as explaining parameters for cognitive impairment in multiple sclerosis

Multiple sclerosis (MS) is a multifocal demyelinating disease of the central nervous system, with lesions widespread through the brain and spinal cord. An important manifestation is cognitive impairment, which, though difficult to measure, may have a major social impact. To better understand the relationship between structural tissue damage and cognitive impairment, we examined the extent and spatial distribution of brain lesions, as measured by magnetic resonance imaging (MRI), in relation to abnormal cognitive performance as measured by the Brief Repeatable Battery (BRB) in 82 MS patients. Possible confounders, like fatigue, pain and depression were also assessed. Brain MR image analysis included hyperintense T2 and hypointense T1 lesion load in the whole brain and the four lobes separately, as well as whole brain volume measurements. Cognitive impairment (defined as more than two abnormal tests) was found in 67% of the patients. Moderately strong correlations were found between the subtests of the BRB and the lesion loads in the brain regions hypothesized to be associated with that cognitive test, although these correlations were in general not much stronger than those between the subtests and the overall lesion load (due to strong interrelationships). The Spatial Recall Test correlated best with parietal lesion load; the Symbol Digit Modalities Test, the Paced Auditory Serial Addition Task (PASAT) and the Word List Generation best with frontal, parietal and temporal lesion load; while the Verbal List Generation Test Index correlated only with atrophy. Atrophy and lesion load were the main factors determining the test scores, explaining 10-25% of the variance in the test results, and were more important than fatigue, pain and depression; only depression had a minor, but significant, additional effect on the PASAT. In conclusion, cognitive impairment in MS is moderately dependent on amount (and distribution) of structural brain damage, especially in the more physically impaired patients group.

Reliability and validity of the pain observation scale for young children and the visual analogue scale in children with burns

The aim of this study was to assess if the pain observation scale for young children (POCIS) and the visual analogue scale (VAS) are reliable and valid instruments to measure procedural and background pain in burned children aged 0-4 years. Burn care nurses (n=73) rated pain from 24 fragments of videotaped children during wound care procedures and during periods of rest using the POCIS and the VAS. Intraclass correlations were used to assess inter-rater and intra-rater reliability for the POCIS and the VAS. Internal consistency for POCIS was assessed by Cronbach's alpha. The POCIS has shown poor to moderate inter-rater reliability, moderate to good intra-rater reliability and an acceptable internal consistency. The VAS turned out to have poor inter-rater reliability and poor to moderate intra-rater reliability. Due to poor results of inter-rater reliability in both scales, construct validation is left undone until more acceptable results are obtained. Factors explaining the results are the large number of raters, the manner they were trained and a lack of variation between pain classes in video fragments. Although not all results were satisfying, an easy to use scale as POCIS has promising qualities and deserves further reliability research.

Impact of diarrhoea and faecal incontinence on the daily life of HIV-infected patients

Diarrhoea in HIV-1 infected persons is an important clinical problem. To improve care and counselling, information about the way, and the extent to which, diarrhoea influences the daily life of these patients can be useful. A cross-sectional descriptive study was performed at the HIV infection clinic of three major hospitals in Amsterdam. A diary, the Coates card system (to determine the relative severity of the symptoms) and an interview were used as outcome measures. Sixty-two patients participated and were classified into four groups: group 1 (minor diarrhoea, n = 26), group 2 (mild diarrhoea, n = 18), group 3 (moderate diarrhoea, n = 7) and group 4 (severe diarrhoea, n = 11). Diarrhoea was considered a very severe symptom in groups 2, 3 and 4. Even mild diarrhoea may have a debilitating impact on the day-to-day life of HIV-infected patients. Faecal incontinence occurs frequently. Patients can worry about their diarrhoea because of lack of information. Patients who do not have diarrhoea according to current definitions of it, consider diarrhoea to be equally problematic as those with (moderate) diarrhoea. More information on prognosis and practical solutions for patients are recommended.

Embryo survival in pseudopregnant and in pregnant but genetically semi-sterile recipients after nonsurgical embryo transfer in the mouse

A new nonsurgical embryo transfer technique was used in the mouse that yielded survival rates of between 40 and 70% depending on embryo stage and, possibly, on the degree of synchrony between the embryo and recipient. Three variables were tested using this embryo transfer technique: a) pseudopregnant recipients vs pregnant but genetically semi-sterile recipients, b) embryos resulting from superovulation vs embryos from natural ovulation, and c) 12-hour vs 24-hour asynchrony between donors and recipients. None of these variables significantly affected the pregnancy rate or the percentage of transferred embryos developing to term. The pregnancy rates were between 77 and 90% in 6 experimental groups of 8 to 13 females. Survival rates were between 41 and 63% when all recipients were considered and between 53 and 68% when only the pregnant recipients were included. The embryo transfer procedure influenced litter size composition of the endogenous conceptuses of the semi-sterile recipients. Too many females were devoid of these. Recipients of expanded blastocysts had significantly better transfer results than recipients that also received morulae and early blastocysts. It was concluded that the transfer success rates were influenced by the recipients and possibly by their preparation for transfer.