Sex steroids/receptor antagonist: their use as adjuncts after trauma-hemorrhage for improving immune/cardiovascular responses and for decreasing mortality from subsequent sepsis

Male versus female inflammatory response after brain death model followed by ex vivo lung perfusion

BACKGROUND

Ex vivo lung perfusion (EVLP) is a useful tool for assessing lung grafts quality before transplantation. Studies indicate that donor sex is as an important factor for transplant outcome, as females present higher inflammatory response to brain death (BD) than males. Here, we investigated sex differences in the lungs of rats subjected to BD followed by EVLP.

METHODS

Male and female Wistar rats were subjected to BD, and as controls sham animals. Arterial blood was sampled for gas analysis. Heart-lung blocks were kept in cold storage (1 h) and normothermic EVLP carried out (4 h), meanwhile ventilation parameters were recorded. Perfusate was sampled for gas analysis and IL-1β levels. Leukocyte infiltration, myeloperoxidase presence, IL-1β gene expression, and long-term release in lung culture (explant) were evaluated.

RESULTS

Brain dead females presented a low lung function after BD, compared to BD-males; however, at the end of the EVLP period oxygenation capacity decreased in all BD groups. Overall, ventilation parameters were maintained in all groups. After EVLP lung infiltrate was higher in brain dead females, with higher neutrophil content, and accompanied by high IL-1β levels, with increased gene expression and concentration in the culture medium (explant) 24 h after EVLP. Female rats presented higher lung inflammation after BD than male rats. Despite maintaining lung function and ventilation mechanics parameters for 4 h, EVLP was not able to alter this profile.

CONCLUSION

In this context, further studies should focus on therapeutic measures to control inflammation in donor or during EVLP to increase lung quality.

The Association of Gender and Mortality in Geriatric Trauma Patients

The association of gender with mortality in trauma remains a subject of debate. Geriatric trauma patients have a higher risk of mortality compared to younger patients. We sought to evaluate the association of gender with mortality in a group of geriatric trauma patients presenting to an academic level 1 trauma center (trauma center designated by New York State capable of handling the most severe injuries and most complex cases). Methods: We performed a retrospective review of geriatric trauma patients who were admitted to our trauma center between January 2018 and December 2020. Data collected included vital signs, demographics, injury, and clinical characteristics, laboratory data and outcome measures. The study controlled for co-morbidities, injury severity score (ISS), and systolic blood pressure (SBP) in the ED. Multivariable logistic regression analysis was performed to evaluate the association of gender and mortality. Results: 4432 geriatric patients were admitted during the study period, there were 1635 (36.9%) men and 3859 (87.2%) were White with an average age of 81 ± 8.5 years. The mean ISS was 6.7 ± 5.4 and average length of stay was 6 ± 6.3 days. There were 165 deaths. Male gender (OR 1.94, 95% CI 1.38 to 2.73), ISS (OR 1.12, 95% CI 1.09 to 1.14), Emergency Department SBP less than 90 mmHg (OR 6.17, 95% CI 3.17 to 12.01), and having more than one co-morbidity (OR 2.28, 95% CI 1.55 to 3.35) were independently predictive of death on multivariable logistic regression analysis. Conclusion: Male gender, Emergency Department systolic blood pressure less than 90 mmHg, having more than one co-morbidity, and injury severity are independent predictors of mortality among geriatric trauma patients.

An Ovine Model of Hemorrhagic Shock and Resuscitation, to Assess Recovery of Tissue Oxygen Delivery and Oxygen Debt, and Inform Patient Blood Management

BACKGROUND

Aggressive fluid or blood component transfusion for severe hemorrhagic shock may restore macrocirculatory parameters, but not always improve microcirculatory perfusion and tissue oxygen delivery. We established an ovine model of hemorrhagic shock to systematically assess tissue oxygen delivery and repayment of oxygen debt; appropriate outcomes to guide Patient Blood Management.

METHODS

Female Dorset-cross sheep were anesthetized, intubated, and subjected to comprehensive macrohemodynamic, regional tissue oxygen saturation (StO2), sublingual capillary imaging, and arterial lactate monitoring confirmed by invasive organ-specific microvascular perfusion, oxygen pressure, and lactate/pyruvate levels in brain, kidney, liver, and skeletal muscle. Shock was induced by stepwise withdrawal of venous blood until MAP was 30 mm Hg, mixed venous oxygen saturation (SvO2) < 60%, and arterial lactate >4 mM. Resuscitation with PlasmaLyte® was dosed to achieve MAP > 65 mm Hg.

RESULTS

Hemorrhage impacted primary outcomes between baseline and development of shock: MAP 89 ± 5 to 31 ± 5 mm Hg (P < 0.01), SvO2 70 ± 7 to 23 ± 8% (P < 0.05), cerebral regional tissue StO2 77 ± 11 to 65 ± 9% (P < 0.01), peripheral muscle StO2 66 ± 8 to 16 ± 9% (P < 0.01), arterial lactate 1.5 ± 1.0 to 5.1 ± 0.8 mM (P < 0.01), and base excess 1.1 ± 2.2 to -3.6 ± 1.7 mM (P < 0.05). Invasive organ-specific monitoring confirmed reduced tissue oxygen delivery; oxygen tension decreased and lactate increased in all tissues, but moderately in brain. Blood volume replacement with PlasmaLyte® improved primary outcome measures toward baseline, confirmed by organ-specific measures, despite hemoglobin reduced from baseline 10.8 ± 1.2 to 5.9 ± 1.1 g/dL post-resuscitation (P < 0.01).

CONCLUSION

Non-invasive measures of tissue oxygen delivery and oxygen debt repayment are suitable outcomes to inform Patient Blood Management of hemorrhagic shock, translatable for pre-clinical assessment of novel resuscitation strategies.

Effects of Androgen Receptor Inhibition on Kanamycin-Induced Hearing Loss in Rats

Megalin has been proposed as an endocytic receptor for aminoglycosides as well as estrogen and androgen. We aimed to investigate the otoprotective effects of antiandrogens (flutamide, FM) on kanamycin (KM)-induced hearing loss in rats. Rats were divided into four groups. The KM group was administered KM (20 mg/kg/day) for 5 days, while the FM group received FM (15 mg/kg/day) for 10 days. In the KM + FM group, KM and FM (15 mg/kg/day) were simultaneously injected for 5 days and then FM was injected for 5 days. Auditory brainstem responses were measured. Western blotting and/or quantitative reverse transcriptase-polymerase chain reaction were performed for megalin, cytochrome P450 1A1 (Cyp1a1), Cyp1b1, metallothionein 1A (MT1A), MT2A, tumor necrosis factor (TNF)-α, caspase 3, and cleaved caspase 3. The FM + KM group showed attenuated auditory thresholds when compared with the KM group at 4, 8, 16, and 32 kHz (all p < 0.05). The KM + FM group showed lower megalin and Cyp1b1 levels than the KM group (all p < 0.05). The KM + FM group revealed lower MT1A, TNFα, and caspase 3 protein levels, compared with those in the KM group (all p < 0.05). Androgen receptor inhibition protects against cochlear injuries in KM-induced hearing loss rats by attenuating megalin expression, revealing anti-inflammatory and anti-apoptotic effects.

Sex-Based Differences in Inpatient Burn Mortality

BACKGROUND

Among burn patients, research is conflicted, but may suggest that females are at increased risk of mortality, despite the opposite being true in non-burn trauma. Our objective was to determine whether sex-based differences in burn mortality exist, and assess whether patient demographics, comorbid conditions, and injury characteristics explain said differences.

METHODS

Adult patients admitted with burn injury-including inhalation injury only-between 2004 and 2013 were included. Inverse probability of treatment weights (IPTW) and inverse probability of censor weights (IPCW) were calculated using admit year, patient demographics, comorbid conditions, and injury characteristics to adjust for potential confounding and informative censoring. Standardized Kaplan-Meier survival curves, weighted by both IPTW and IPCW, were used to estimate the 30-day and 60-day risk of inpatient mortality across sex.

RESULTS

Females were older (median age 44 vs. 41 years old, p < 0.0001) and more likely to be Black (32% vs. 25%, p < 0.0001), have diabetes (14% vs. 10%, p < 0.0001), pulmonary disease (14% vs. 7%, p < 0.0001), heart failure (4% vs. 2%, p = 0.001), scald burns (45% vs. 26%, p < 0.0001), and inhalational injuries (10% vs. 8%, p = 0.04). Even after weighting, females were still over twice as likely to die after 60 days (RR 2.87, 95% CI 1.09, 7.51).

CONCLUSION

Female burn patients have a significantly higher risk of 60-day mortality, even after accounting for demographics, comorbid conditions, burn size, and inhalational injury. Future research efforts and treatments to attenuate mortality should account for these sex-based differences. The project was supported by the National Institutes of Health, Grant Number UL1TR001111.

Characterization of serum levels of testosterone and corticosterone in a blast and amputation rat model of heterotopic ossification

INTRODUCTION

Endocrine dysregulation's role in heterotopic ossification (HO) remains unexplored. We sought to examine corticosterone and testosterone in established rat models of ectopic bone formation, and correlate to HO formation with CT analysis.

METHODS

Fifteen rats were placed into three groups of traumatic injury patterns: Blast and injury (120 kPa blast, femoral fracture and quadriceps crush), injury only, and blast only. Serum corticosterone and testosterone levels were drawn until post-operative day 40. HO was analyzed using CT.

RESULTS

Corticosterone levels peaked in the blast and injury group in the shortest time post injury, followed by injury only and blast only groups. Testosterone levels reached nadir in similar fashion. Volume of HO was highest in the blast and injury group, followed by the injury only group.

CONCLUSION

Corticosterone and testosterone's contribution to HO formation requires further characterization, but this study suggests that high peaks in corticosterone and a low nadir in testosterone are associated with higher volumes of HO.

17β-Estradiol, a potential ally to alleviate SARS-CoV-2 infection

Considering that female sexual hormones may modulate the inflammatory response and also exhibit direct effects on the cells of the immune system, herein, we intend to discuss the sex differences and the role of estradiol in modulating the lung and systemic inflammatory response, focusing on its possible application as a treatment modality for SARS-CoV-2 patients. COVID-19 patients develop severe hypoxemia early in the course of the disease, which is silent most of the time. Small fibrinous thrombi in pulmonary arterioles and a tumefaction of endothelial were observed in the autopsies of fatal COVID-19 cases. Studies showed that the viral infection induces a vascular process in the lung, which included vasodilation and endothelial dysfunction. Further, the proportions of CD4+ T and CD8+ T lymphocytes were strongly reduced in patients with severe SARS-CoV-2 infection. Estradiol is connected with CD4+ T cell numbers and increases T-reg cell populations, affecting immune responses to infection. It is known that estradiol exerts a protective effect on endothelial function, activating the generation of nitric oxide (NO) via endothelial nitric oxide synthase. Estrogen attenuates the vasoconstrictor response to various stimuli and induces vasodilation in the pulmonary vasculature during stress situations like hypoxia. It exerts a variety of rapid actions, which are initiated after its coupling with membrane receptors, which in turn, may positively modulate vascular responses in pulmonary disease and help to maintain microvascular flow. Direct and indirect mechanisms underlying the effects of estradiol were investigated, and the results point to a possible protective effect of estradiol against COVID-19, indicating that it may be considered as an adjuvant therapeutic element for the treatment of patients affected by the novel coronavirus.

Recombinant Thrombomodulin on Neutrophil Extracellular Traps in Murine Intestinal Ischemia–Reperfusion

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background

In multiple-organ dysfunction, an injury affecting one organ remotely impacts others, and the injured organs synergistically worsen outcomes. Recently, several mediators, including extracellular histones and neutrophil extracellular traps, were identified as contributors to distant organ damage. This study aimed to elucidate whether these mediators play a crucial role in remote organ damage induced by intestinal ischemia–reperfusion. This study also aimed to evaluate the protective effects of recombinant thrombomodulin, which has been reported to neutralize extracellular histones, on multiple-organ dysfunction after intestinal ischemia–reperfusion.

Methods

Intestinal ischemia was induced in male C57BL/6J mice via clamping of the superior mesenteric artery. Recombinant thrombomodulin (10 mg/kg) was administered intraperitoneally with the initiation of reperfusion. The mice were subjected to a survival analysis, histologic injury scoring, quantitative polymerase chain reaction analysis of tumor necrosis factor-α and keratinocyte-derived chemokine expression, Evans blue dye vascular permeability assay, and enzyme-linked immunosorbent assay analysis of histones in the jejunum, liver, lung, and kidney after 30- or 45-min ischemia. Neutrophil extracellular trap formation was evaluated by immunofluorescence staining.

Results

Recombinant thrombomodulin yielded statistically significant improvements in survival after 45-min ischemia (ischemia–reperfusion without vs. with 10 mg/kg recombinant thrombomodulin: 0% vs. 33%, n = 21 per group, P = 0.001). Recombinant thrombomodulin reduced the histologic injury score, expression of tumor necrosis factor-α and keratinocyte-derived chemokine, and extravasation of Evans blue dye, which were augmented by 30-min ischemia–reperfusion, in the liver, but not in the intestine. Accumulated histones and neutrophil extracellular traps were found in the livers and intestines of 30-min ischemia–reperfusion–injured mice. Recombinant thrombomodulin reduced these accumulations only in the liver.

Conclusions

Recombinant thrombomodulin improved the survival of male mice with intestinal ischemia–reperfusion injury. These findings suggest that histone and neutrophil extracellular trap accumulation exacerbate remote liver injury after intestinal ischemia–reperfusion. Recombinant thrombomodulin may suppress these accumulations and attenuate liver injury.

Gender differences in response to abdominal compartment syndrome in rats

Objective

Our study aims to emphasize the novelty of female rats in regard to their hemodynamic changes in response to abdominal compartment syndrome. A group of 64 rats was randomly divided into 4 subgroups for each gender. Except for the control, intra-abdominal pressure was increased to 10, 20, 30 mmHg. Survival time, mean arterial pressure, pH and lactate were determined at different time intervals.

Results

As IAP was 20 mmHg, a statistically difference was seen between the male group and the female group starting from 15 min (126 ± 9.7 mmHg, 124 ± 14.7 mmHg respectively, p < 0.02) and lasting 2 h. At 30 mmHg, a statistically difference was seen between 30 to 60 min (p < 0.05). Only group 2 presented results with statistical power both at 30 and at 60 min concerning pH (p = 0.003, p < 0.001 respectively). In the lactate measurements at IAP of 10 mmHg, at 60 min male lactate level was 3.93 ± 1.13 and 2.25 ± 0.33 in female rats (p = 0.034). Female rats that were subjected to IAP of 20 mmHg and 30 mmHg had significantly better survival than male rats that were subjected to the same pressure (p < 0.05 and p < 0.01, respectively). We concluded that female rats have better preserved their hemodynamic and metabolic parameters during ACS than male rats.

Can distinctly different rapid estrogen actions share a common mechanistic step?

Contribution to Special Issue on Fast effects of steroids. This paper reviews early evidence for the existence of rapid, non-genomic effects of estrogens on neurons, and, further, proposes that these rapid effects are often synergistic with later, genomic effects. Finally, suggestions about potential molecular mechanisms underlying the rapid effects of estrogens are offered. A mechanistic step we propose to be common among rapid estrogenic actions includes membrane ER's binding to histamine, and NMDA receptors and subsequent dimerization, and clustering (respectively) in a manner that enhances histamine and NMDA actions.

Georeferencing of deaths from sepsis in the city of São Paulo

Objective

The aim of the present study was to obtain information about deaths due to sepsis in São Paulo from 2004 to 2009 and their relationship with geographical distribution.

Methods

Causes of death, both main and secondary, were defined according to the codes of the International Classification of Disease version 10 (ICD-10) contained in the database. Sepsis, septic shock, multiple organ failure, pneumonia, urinary tract infection, peritonitis and other intraabdominal infections, skin and soft tissue infections (including surgical wound infection) and meningitis were considered as immediate cause of death or as the condition leading to the immediate cause of death related or associated to sepsis.

Results

In the analyzed period, there was a 15.3% increase in the absolute number of deaths from sepsis in São Paulo. The mean number of deaths during this period was 28,472 ± 1566. Most deaths due to sepsis and sepsis-related diseases over the studied period occurred in a hospital or health care facility, showing that most of the patients received medical care during the event that led to death. We observed a significant concentration of deaths in the most populous regions, tending more toward the center of the city.

Conclusions

Georeferencing data from death certificates or other sources can be a powerful tool to uncover regional epidemiological differences between populations. Our study revealed an even distribution of sepsis all over the inhabited areas of São Paulo.

Hepatoprotective effect of casodex after trauma hemorrhage in a rodent model

Casodex (bicalutamide), an androgen receptor antagonist, is used for the treatment of prostate cancer. Recent evidences show that Akt signaling pathway exerts organ-protective effects after injury. The aim of this study was to investigate whether Akt plays any role in the casodex-mediated attenuation of hepatic injury after trauma-hemorrhagic shock. Male Sprague-Dawley rats underwent trauma hemorrhage (mean blood pressure kept at approximately 35-40 mm Hg for 90 min), followed by fluid resuscitation. During resuscitation, a single dose of casodex (5 mg/kg, intravenous) with and without a phosphatidylinositol 3-kinase inhibitor wortmannin (1 mg/kg, intravenous), wortmannin or vehicle was administered. Plasma aspartate aminotransferase and alanine aminotransferase levels and various hepatic parameters were measured at 24 h after resuscitation. One-way analysis of variance and the Tukey test were used for statistical analysis. These results showed that trauma hemorrhage increased hepatic myeloperoxidase activity, interleukin 6 and intercellular adhesion molecule 1 levels, and plasma aspartate aminotransferase and alanine aminotransferase concentrations. In the trauma hemorrhage rats treated with casodex, these parameters were significantly improved. Casodex treatment also increased hepatic phospho-Akt expression compared with vehicle-treated trauma hemorrhaged rats. Coadministration of wortmannin with casodex abolished the casodex-induced advantageous effects on the aforementioned parameters and hepatic injury. Our results suggest that the protective effect of casodex administration on attenuation of hepatic injury after trauma hemorrhage, which is, at least in part, through Akt-dependent pathway.

The role of biological sex in severely traumatized patients on outcomes: a matched-pair analysis

OBJECTIVE

Analyze sex differences in TraumaRegister DGU (TR-DGU).

BACKGROUND

Sex differences are considered to influence trauma outcomes. However, clinical study results are controversial.

METHODS

Of 29,353 prospectively recorded cases of TR-DGU, we included primary trauma room admissions with Injury Severity Score of 9 or more into the analysis. Pairs (n = 3887) were formed from 1 male and 1 female according to age, mechanism, injury severity by Abbreviated Injury Scale (for head, thorax, abdomen, extremities), and occurrence of prehospital shock. Biochemical markers, treatment modalities, length of stay, and outcome (multiple organ failure, sepsis, mortality rates) were assessed. Statistical significance was accepted at P < 0.05. Odds ratios (ORs) are given with 95% confidence interval (CI).

RESULTS

Females had less multiple organ failure [OR: 1.18 (95% CI, 1.05-1.33); P = 0.007], particularly in age group of 16 to 44 years; sepsis [OR: 1.45 (95% CI, 1.21-1.74); P < 0.001]), particularly at age more than 45 years; and mortality [OR: 1.14 (95% CI, 1.01-1.28); P = 0.037]. Prehospital chest tube insertions (214 vs 158) and surgical procedures before intensive care unit admission were more often performed in males (79.7% vs 76.4%). Females had lower mean hemoglobin levels [10.7 ± 2.6 vs 11.9 ± 2.8 (mg/dL)]. There were no sex differences in fluid resuscitation, shock index, coagulation, and base excess.

CONCLUSIONS

Males are more susceptible to multiple organ failure, sepsis, and mortality after trauma. Differences were not exclusively related to reproductive age and thus cannot be attributed to sex hormones alone. Females aged 16 to 44 years seem to tolerate shock better. Higher susceptibility to sepsis might be explained by male immune function or increased systemic burden from higher rates of surgical interventions.

Emergency Medicine Gender-specific Education

The 2014 Academic Emergency Medicine consensus conference has taken the first step in identifying gender-specific care as an area of importance to both emergency medicine (EM) and research. To improve patient care, we need to address educational gaps in this area concurrent with research gaps. In this article, the authors highlight the need for sex- and gender-specific education in EM and propose guidelines for medical student, resident, and faculty education. Specific examples of incorporating this content into grand rounds, simulation, bedside teaching, and journal club sessions are reviewed. Future challenges and strategies to fill the gaps in the current education model are also described.

Female sex protects from organ failure and sepsis after major trauma haemorrhage

INTRODUCTION

Biological sex is considered a risk factor for adverse outcome after major trauma. We hypothesized that female sex is protective against organ failure, sepsis and mortality in patients with traumatic haemorrhage.

PATIENTS AND METHODS

We selected patients from TraumaRegister DGU(®) (TR-DGU) with primary admission for blunt trauma with an injury severity score ≥ 16 and an ICU stay ≥ 3 days that presented with relevant bleeding in the years 2007-2012. Relevant bleeding was defined as Abbreviated Injury Scale (AIS) ≥ 3 with an estimated blood loss exceeding 20%, any femoral shaft fracture, any pelvic clamp as surrogate for unstable pelvic fracture or the presence of at least one criteria of haemorrhagic shock: shock index of 0.8-1.4; base excess of -2.0 to -10.0 mmol/L; body temperature ≤ 34°C; transfusion of ≥ 4 units of packed red blood cells; application of recombinant activated factor VII; any embolization during trauma room phase and pre-hospital resuscitation volume ≥ 3000 ml or any catecholamine use during pre-hospital care in the absence of cardiopulmonary resuscitation. A total of 7560 males and 2774 females were selected and analyzed for sex differences.

RESULTS

Higher rates of multiple organ failure (24.4 vs. 21.3%, Odds ratio [OR] 1.19 (95% confidence interval [95%CI] 1.07-1.33), p=0.001*) and sepsis (16.5 vs. 11.3%, OR 1.55 (95%CI 1.35-1.77), p<0.001*) were observed in males. Organ function of lung, cardio-circulatory system, liver and kidney were better in females, however, there was no difference in mortality. Stratification by age group revealed that in particular age-group 16-44 years was related to improved organ function which may indicate effects of sex hormones in females at reproductive age. Increased rates of sepsis in males were observed throughout virtually all age groups starting at 16 years of age, except in age group 54-64 years. This may suggest suppressive effect of testosterone on immune function.

CONCLUSIONS

Our study supports the hypothesis that female sex is associated with improved organ function following traumatic injury and haemorrhagic shock, in particular in age groups that are at reproductive age. However, further studies are warranted before sex steroids can be deployed as therapeutic intervention in critically ill trauma patients.

Prediction of sepsis in trauma patients

Trauma is one of the leading causes of death worldwide. Approximately 39.5% of deaths occur in the hospital, and the mortality rate of delayed death caused by septic complications is still high. Early prediction of the development of sepsis can help promote early intervention and treatment for patients and contribute to improving patient outcomes. Thus so far, biomarkers, patient demographics and injury characteristics are the main methods used for predicting sepsis in trauma patients. However, studies that verify their predictive value are limited, and the results are still controversial. More work should be conducted to explore more efficient and accurate ways to predict post-traumatic sepsis.

Age and sex differences in vascular responsiveness in healthy and trauma patients: contribution of estrogen receptor-mediated Rho kinase and PKC pathways

Several medical conditions exhibit age- and sex-based differences. Whether or not traumatic shock exhibits such differences with regard to vascular responsiveness is not clear. In a cohort of 177 healthy subjects and 842 trauma patients (21–82 years) as well as different ages (4, 8, 10, 14, 18, and 24 wk; 1 and 1.5 years) and sexes of Sprague-Dawley normal and traumatic shock rats, the age- and sex-based differences of vascular responsiveness and the underlying mechanisms were investigated. Middle-aged and young women as well as female rats of reproductive age had higher vascular responsiveness in the normal condition and a lower decrease in vascular responsiveness after traumatic shock than older men and male rats of identical age. Exogenous supplementation of 17β-estrdiol increased vascular reactivity in both male and femal rats of 8–24 wk and preserved vascular responsiveness in rats following traumatic shock. No effect was observed in rats 1 to 1.5 years. These protective effects of estrogen were closely related to G protein-coupled receptor (GPR)30, estrogen receptor-mediated Rho kinase, and PKC pathway activation. Vascular responsiveness exhibits age- and sex-based differences in healthy subjects and trauma patients. Estrogen and its receptor (GPR30) mediated activation of Rho kinase and PKC using genomic and nongenomic mechanisms to elicit protective effects in vascular responsiveness. This finding is important for the personalized treatment for several age- and sex-related diseases involving estrogen.

Resveratrol restores sirtuin 1 (SIRT1) activity and pyruvate dehydrogenase kinase 1 (PDK1) expression after hemorrhagic injury in a rat model

Severe hemorrhage leads to decreased blood flow to tissues resulting in decreased oxygen and nutrient availability affecting mitochondrial function. A mitoscriptome profiling study demonstrated alteration in several genes related to mitochondria, consistent with the mitochondrial functional decline observed after trauma hemorrhage (T-H). Our experiments led to the identification of sirtuin 1 (SIRT1) as a potential target in T-H. Administration of resveratrol (a naturally occurring polyphenol and activator of SIRT1) after T-H improved left ventricular function and tissue ATP levels. Our hypothesis was that mitochondrial function after T-H depends on SIRT1 activity. In this study, we evaluated the activity of SIRT1, a mitochondrial functional modulator, and the mitochondrial-glycolytic balance after T-H. We determined the changes in protein levels of pyruvate dehydrogenase kinase (PDK)-1 and nuclear c-Myc, peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α and NF-E2-related factor (NRF)2 after T-H and after treatment with resveratrol or a combination of sirtinol (a SIRT1 inhibitor) and resveratrol. We have also tested the activity of mitochondrial complex 1. SIRT1 enzyme activity was significantly decreased after T-H, whereas resveratrol treatment restored the activity. We found elevated PDK1 and c-Myc levels and decreased PGC-1α, NRF2 and mitochondrial complex I activity after T-H. The reduced SIRT1 activity after T-H may be related to declining mitochondrial function, since resveratrol was able to reinstate SIRT1 activity and mitochondrial function. The elevated level of PDK1 (an inhibitor of pyruvate dehydrogenase complex) after T-H indicates a possible shift in cellular energetics from mitochondria to glycolysis. In conclusion, SIRT1 modulation alters left ventricular function after T-H through regulation of cellular energetics.

Ischemic and oxidative damage to the hypothalamus may be responsible for heat stroke

The hypothalamus may be involved in regulating homeostasis, motivation, and emotional behavior by controlling autonomic and endocrine activity. The hypothalamus communicates input from the thalamus to the pituitary gland, reticular activating substance, limbic system, and neocortex. This allows the output of pituitary hormones to respond to changes in autonomic nervous system activity. Environmental heat stress increases cutaneous blood flow and metabolism, and progressively decreases splanchnic blood flow. Severe heat exposure also decreases mean arterial pressure (MAP), increases intracranial pressure (ICP), and decreases cerebral perfusion pressure (CPP = MAP - ICP), all of which lead to cerebral ischemia and hypoxia. Compared with normothermic controls, rodents with heatstroke have higher hypothalamic values of cellular ischemia (e.g., glutamate and lactate-to-pyruvate ratio) and damage (e.g., glycerol) markers, pro-oxidant enzymes (e.g., lipid peroxidation and glutathione oxidation), proinflammatory cytokines (e.g., interleukin-1β and tumor necrosis factor-α), inducible nitric oxide synthase-dependent nitric oxide, and an indicator for the accumulation of polymorphonuclear leukocytes (e.g., myeloperoxidase activity), as well as neuronal damage (e.g., apoptosis, necrosis, and autophagy) after heatstroke. Hypothalamic values of antioxidant defenses (e.g., glutathione peroxidase and glutathione reductase), however, are lower. The ischemic, hypoxic, and oxidative damage to the hypothalamus during heatstroke may cause multiple organ dysfunction or failure through hypothalamic-pituitary-adrenal axis mechanisms. Finding the link between the signaling and heatstroke-induced hypothalamic oxidative and ischemic damage might allow us to clinically attenuate heatstroke. In particular, free radical scavengers, heat shock protein-70 inducers, hypervolemic hemodilution, inducible nitric oxide synthase inhibitors, progenitor stem cells, flutamide, estrogen, interleukin-1 receptor antagonists, glucocorticoid, activated protein C, and baicalin mitigate preclinical heatstroke levels.

Effects of 17ß-Estradiol on the Acute Necrotizing Pancreatitis after Onset in Rats

The aim of this study was to investigate the influence of 17ß-estradiol (E2) on acute necrotizing pancreatitis (ANP) induced by glycodeoxycholic acid in rats. Rats were divided into six groups as sham + saline, sham + single dose E2 (SDE2), sham + multiple dose E2 (MDE2), ANP + saline, ANP + SDE2, and ANP + MDE2. ANP in rats was induced by glycodeoxycholic acid. The extent of acinar cell injury, mortality, systemic cardiorespiratory variables, functional capillary density (FCD), renal/hepatic functions, and changes in some enzyme markers for pancreatic and lung tissue were investigated during ANP in rats. The induction of ANP resulted in a significant increase in the mortality rate, pancreatic necrosis, and serum activity of amylase, alanine aminotransferase (ALT), interleukin (IL)-6, lactate dehydrogenase (LDH) in bronchoalveolar lavage (BAL) fluid, serum concentration of urea, and tissue activity of myeloperoxidase (MPO) and malondialdehyde (MDA) in the pancreas and lung, and a significant decrease in concentrations of calcium, blood pressure, urine output, p02, and functional capillary density (FCD). The use of E2 did not alter these changes. E2 demonstrated no effect on the course of ANP in rats. Therefore, it has no value in the treatment during acute pancreatitis.

Increased admission serum estradiol level is correlated with high mortality in patients with severe acute pancreatitis

BACKGROUND

Sexual dimorphism in critical diseases has been documented. Severe acute pancreatitis is a disease with high mortality. We hypothesized that admission sex hormone levels may be used as an early predictor of outcome in these patients.

METHODS

A prospective cohort of patients with severe acute pancreatitis admitted to the intensive care unit for at least 48 h were enrolled (n = 62). Serum levels of estradiol, progesterone, and testosterone were determined on admission. The association of sex hormone levels and various disease severity scoring systems with patient outcome was analyzed.

RESULTS

There was no difference in overall mortality between the sexes. However, estradiol was significantly elevated in nonsurvivors (39 vs. 206 pg/mL, p < 0.001). The estradiol level was the best single-variable predictor of mortality (area under the curve 0.97), followed by the sequential organ failure assessment score, the multiple organ dysfunction score, and the acute physiology and chronic health care evaluation II (APACHE II) score. A serum estradiol level of 102 pg/mL was both sensitive and specific to predict mortality. There were no differences between survivors and non-survivors in terms of age, body mass index, or progesterone and testosterone levels.

CONCLUSIONS

Admission serum estradiol level is a good marker of disease severity and predictor of death in patients with severe acute pancreatitis.

[Gender aspects in anesthesia : modified approach in research and treatment?]

Gender differences can have a relevant influence on the perioperative outcome as male and female patients are affected differently by adverse events, e.g. side effects of drugs. Furthermore, differences relating to specific drug effects, comorbidities and outcome after anesthesia or intensive care have been demonstrated. There seems to be a gender bias in diagnosis and therapy. While the knowledge regarding this field is still growing certain aspects have already been integrated into clinical practice: prevention of postoperative nausea and vomiting (PONV), target controlled infusion (TCI) model and male only policy with production of blood products. There is a need to study the influence of gender, age and race in order to optimize treatment towards a more individualized therapy. This article highlights already identified differences and discusses potential underlying mechanisms.

Gender-specific medicine: yesterday's neglect, tomorrow's opportunities

The Institute of Medicine has stated that analyzing data according to sex and gender may change practices used by clinicians and taught in medical education. Gender-specific medicine embraces the concept that differences between men and women encompass the entire organism, not just their reproductive biology, and that recognizing these differences will improve the precision and quality of health care for both men and women. Research conducted to date has deepened our scientific understanding of sex and gender differences in the etiology, diagnosis, progression, outcomes, treatment, and prevention of many conditions that affect both women and men. The rapid growth and maturation of emergency medicine (EM) research provides a major opportunity to make an impact in this broad area of scientific inquiry. However, recent evidence suggests that barriers to the recognition of gender in funded and published research persist. Without systematic inclusion in research, and medical school and residency curricula, gender-based medicine cannot be translated into widespread clinical practice. Collaborations between women's health researchers across fields of medicine will be essential, given the large knowledge deficits to be addressed and the gender-based issues that span all specialties. We provide one model for a multifaceted initiative targeting improvements in gender medicine for the specialty of EM. If emergency health services are to meet the needs of both women and men at modern-day standards, then they must acknowledge the emerging science demonstrating that sex and gender differences influence the delivery of high-quality clinical care.

Flutamide, an androgen receptor antagonist, improves heatstroke outcomes in mice

Flutamide has been used as an adjunct for decreasing the mortality from subsequent sepsis. Heatstroke resembles septic shock in many aspects. We hypothesized that heat-induced multiple organ dysfunction syndromes and lethality could be reduced by flutamide therapy. In heatstroke groups, mice were exposed to whole body heating (41.2°C, for 1h) in a controlled-environment chamber. The heat-stressed mice were returned to normal room temperature (24°C) after whole body heating. Mice still alive on day 4 of WBH treatment were considered survivors. Physiological and biochemical parameters were monitored for 2.5h post-WBH. Heatstroke mice were subcutaneously treated with flutamide (12.5-50mg/kg body weight in 0.05 ml) or vehicle solution (0.05 ml/kg body weight) once daily for 3 consecutive days post-WBH. We evaluated the effect of flutamide in heatstroke mice and showed that flutamide significantly (i) attenuated hypothermia, (ii) reduced the number of apoptotic cells in the hypothalamus, the spleen, the liver, and the kidney, (iii) attenuated the plasma index of toxic oxidizing radicals (e.g., nitric oxide metabolites and hydroxyl radicals), (iv) diminished the plasma index of the organ injury index (e.g., lactate dehydrogenase), (v) attenuated plasma systemic inflammation response molecules (e.g., tumor necrosis factor-α and interleukin-6), (vi) reduced the index of infiltration of polymorphonuclear neutrophils in the lung (e.g., myeloperoxidase activity), and (vii) allowed three times the fractional survival compared with vehicle. Thus, flutamide appears to be a novel agent for the treatment of mice with heatstroke or patients in the early stage of heatstroke.

Gender dimorphism in the gut: mucosal protection by estrogen stimulation of IgA transcytosis

BACKGROUND

Laboratory studies demonstrate gender dimorphism following trauma/hemorrhagic shock (T/HS). These differences have been attributed to estrogen (E2) levels. Maintenance of gut barrier function by E2 following T/HS has been recently described. However, the mechanisms are not clear. The principle humoral defense mechanism of the gut is provided by secretory immunoglobulin IgA. It is transported across intestinal epithelial cells (IEC) by a specific transmembrane protein receptor (polyimmunoglobulin receptor, pIgR). Transport of IgA (transcytosis) may be influenced by a number of factors. We postulated that there may be differences in IgA transcytosis and IEC pIgR expression in response to sex hormones. We studied this in vitro.

METHODS

Confluent HT-29 IEC monolayers were established in a two-chamber cell culture system. E2 or dihydrotestosterone (DHT) was added for 72 hours; then dimeric IgA (dIgA) was added to the basal chamber (4°C, to obtain maximal pIgR binding of dIgA). Apical media were sampled at intervals and recovery of secretory immunoglobulin IgA quantitated by enzyme-linked immunosorbent assay. PIgR expression in HT-29 cells was quantitated as mean fluorescence intensity using flow cytometry. Monolayer integrity was confirmed by serial measurement of transepithelial electrical resistance.

RESULTS

IgA transcytosis increased fourfold in 12-hour versus 3-hour culture periods in the control experiments. A similar finding was noted in the DHT experiments on IgA transcytosis. There were dramatic increases in IgA transcytosis across HT-29 cells exposed to E2.This was apparent at both 3- and 12-hour experimental time points and exhibited a dose-response effect. HT-29 cells cocultured with E2 increased pIgR expression in a time- and dose-dependent fashion. The greatest pIgR expression was noted following coculture of HT-29 cells with E2 for 6 days at the 1.0 μmol/L E2 concentration. The integrity of HT-29 monolayers in both the E2 and DHT treatment groups at T = 0 and 72 hours was assessed and showed no significant differences versus control cells.

CONCLUSION

IgA transcytosis was augmented by E2 in a dose-response fashion. This effect was due to augmented intracellular trafficking of IgA and later partly due to increased pIgR expression. The dose-related effects of E2 on IgA transport confirm the findings in animal studies that improved outcomes in females can be related to the estrus cycle.

Female stem cells are superior to males in preserving myocardial function following endotoxemia

Mesenchymal stem cells (MSCs) may offer therapeutic benefit in the setting of sepsis and endotoxemia. Previous studies suggest that MSCs from female donors may possess better protective capabilities than their male counterparts. The present study examined whether female MSCs may offer a greater protective advantage in the setting of endotoxemic cardiac dysfunction compared with male MSCs. Adult male Sprague-Dawley rats were injected intraperitoneally with LPS and then treated with intraperitoneal injections of either saline, female MSCs, or male MSCs. Hearts and serum were then collected for analysis of myocardial function, myocardial protein, and myocardial and serum cytokines. Compared with male MSC or vehicle-treated animals, female MSC treatment resulted in greater preservation of myocardial function (P < 0.001). Serum and myocardial levels of all measured cytokines were comparable between rats given MSCs from male or female donors but substantially improved over rats given vehicle (P < 0.05). Reduced myocardial inflammation correlated with reduced levels of phosphorylated p38 MAPK expression in the myocardium of animals injected with MSCs of either sex (P < 0.05). The Bcl-xL/Bax ratio was increased to a greater extent following treatment with female MSCs vs. male MSCs (P < 0.05). Intraperitoneal administration of MSCs is effective in limiting myocardial inflammation and dysfunction in the rat endotoxemia model. Compared with treatment with their male counterparts, MSC treatment from female donors is associated with greater cardiac protection against acute endotoxemic injury.

Sex differences in nuclear receptor-regulated liver metabolic pathways

Liver metabolism is markedly sex-dimorphic; accordingly, the prevalence of liver diseases is different between sexes. The superfamily of nuclear receptors (NRs) governs the proper expression of key liver metabolism genes by sensing lipid-soluble hormones and dietary lipids. When the expression of those genes is deregulated, disease development is favored. However, we lack a comprehensive picture of the differences between NR actions in males and females. Here, we reviewed explorative studies that assessed NR functions in both sexes, and we propose a first map of sex-dimorphic NR expression in the liver. Our analysis suggested that NRs in the female liver exhibited cross-talk with more liver-protective potential than NRs in male liver. This study provides empirical support to the hypothesis that women are more resilient to some liver diseases than men, based on a more compensative NR network. This article is part of a Special Issue entitled: Translating nuclear receptors from health to disease.

Sex differences in destructive periodontal disease: exploring the biologic basis

BACKGROUND

Epidemiologic studies provide broad-based evidence that men are at greater risk for developing destructive periodontal disease than women, even after adjusting for behavioral and environmental factors, such as oral hygiene practice and smoking. What requires clarification, however, is whether sex-specific differences in immune function provide a plausible biologic basis for a sexual dimorphism in susceptibility to destructive periodontal disease. This review examines evidence that might provide an underlying biologic basis for a sexual dimorphism in the prevalence and severity of destructive periodontal disease.

METHODS

A narrative review of the literature related to sexual dimorphism in pathogen-mediated inflammatory diseases and immune response was retrieved from searches of computerized databases (MEDLINE, PubMed, and SCOPUS).

RESULTS

Sex steroids exert profound effects on multiple immunologic parameters regulating both the amplification and resolution of inflammation. Strong evidence exists for sexual dimorphisms in immune function, involving both innate and acquired immunity. Injury and infection have been associated with higher levels of inflammatory cytokines, including interleukin-1β and tumor necrosis factor-α, in men than women, paralleling observed sex-specific differences in periodontitis.

CONCLUSION

Differential gene regulation, particularly in sex steroid-responsive genes, may contribute to a sexual dimorphism in susceptibility to destructive periodontal disease.

Systemic inflammatory response syndrome outcome in surgical patients

INTRODUCTION

The problems of inflammation and infection as a leading cause of organ dysfunction and failure is a major problem after injury or operations. When systemic inflammatory response syndrome (SIRS) progress to multiple organ failure (MOF), the mortality reach up to 30-80% depending on the number of failed organs. Recent discoveries and improvement in patient care, a reasonable question then arises, are the incidence of MOF decreasing? The literature suggests a decrease in mortality of patients with severe organ failure and a decrease in elective surgical mortality in patients.

METHODS

This is prospective study of 50 patients who underwent surgical procedure. They were followed up till date of termination with daily SIRS monitoring, development of MODS and MOF. Risk factors for MOF are addressed.

RESULTS

There are total 31 patients who develop SIRS, of whom 7 patients develop severe sepsis and 4 went into MOF.

CONCLUSION

Early detection of SIRS helps us to prevent multiple organ dysfunction syndrome (MODS)/MOF, leading to lesser hospital stay and better outcome.