Women who pre-game: A study of stress and alcohol use in female collegiate predrinkers

Introduction: This study examined the relationship between stress and pre-gaming (i.e., drinking prior to going out to an event) in female college students. Methods: Thirty-four female college students were grouped as pre-gamers or non-pre-gamers based on self-reported drinking patterns. They completed surveys about alcohol use and mental health and provided a set of salivary cortisol samples upon waking, 30 min later, and at 10am on the same day. Results: Pre-gamers and non-pre-gamers did not differ on demographics or psychosocial variables. Pre-gamers reported riskier drinking overall and had greater endorsement of social, coping, and enhancement drinking motives. Pre-gamers also had lower cortisol levels 30 min after waking and exhibited attenuated CAR. Conclusions: Female collegiate pre-gamers may differ from their peers not only in terms of alcohol consumption and drinking motives, but also on attenuated CAR, a physiological biomarker associated with stress dysregulation and vulnerability to addictive behaviors.

Extreme thrombocytosis is associated with critical illness and young age, but not increased thrombotic risk, in hospitalized pediatric patients

BACKGROUND

Extreme thrombocytosis (EXT, platelet count > 1000 × 103 /μL) is an uncommon but potentially clinically significant finding. Primary EXT in the setting of myeloproliferative disorders is linked to thrombotic and/or bleeding complications more frequently than secondary EXT, which typically occurs in reaction to infection, inflammation, or iron deficiency. However, comorbidities have been reported in adults with secondary EXT. Clinical implications of EXT in children are not well defined, as prior studies targeted small and/or specialized pediatric populations.

OBJECTIVES

Our objectives were to determine etiologies and sequelae of EXT in a hospitalized general pediatric patient population.

PATIENTS AND METHODS

We retrospectively analyzed EXT cases from a single-center pediatric cohort of ~80 000 patients over 8 years.

RESULTS

Virtually all cases (99.8%) were secondary in nature, and most were multifactorial. Many cases of EXT occurred in children under 2 years old (47%) and/or during critical illness (55%). No thrombotic or bleeding events directly resulted from EXT, confirming a paucity of clinical complications associated with EXT in pediatric patients. There were indications that neonatal hematopoiesis and individual genetic variation influenced some cases, in addition to certain diagnoses (eg, sickle cell anemia) and clinical contexts (eg, asplenia).

CONCLUSION

Our findings confirm that thrombotic events related to EXT are rare in pediatric patients, which can inform the use of empiric anti-platelet therapy.

Prevention of carcinogen and inflammation-induced dermal cancer by oral rapamycin includes reducing genetic damage

Cancer prevention is a cost-effective alternative to treatment. In mice, the mTOR inhibitor rapamycin prevents distinct spontaneous, noninflammatory cancers, making it a candidate broad-spectrum cancer prevention agent. We now show that oral microencapsulated rapamycin (eRapa) prevents skin cancer in dimethylbenz(a)anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA) carcinogen-induced, inflammation-driven carcinogenesis. eRapa given before DMBA/TPA exposure significantly increased tumor latency, reduced papilloma prevalence and numbers, and completely inhibited malignant degeneration into squamous cell carcinoma. Rapamycin is primarily an mTORC1-specific inhibitor, but eRapa did not reduce mTORC1 signaling in skin or papillomas, and did not reduce important proinflammatory factors in this model, including p-Stat3, IL17A, IL23, IL12, IL1β, IL6, or TNFα. In support of lack of mTORC1 inhibition, eRapa did not reduce numbers or proliferation of CD45(-)CD34(+)CD49f(mid) skin cancer initiating stem cells in vivo and marginally reduced epidermal hyperplasia. Interestingly, eRapa reduced DMBA/TPA-induced skin DNA damage and the hras codon 61 mutation that specifically drives carcinogenesis in this model, suggesting reduction of DNA damage as a cancer prevention mechanism. In support, cancer prevention and DNA damage reduction effects were lost when eRapa was given after DMBA-induced DNA damage in vivo. eRapa afforded picomolar concentrations of rapamycin in skin of DMBA/TPA-exposed mice, concentrations that also reduced DMBA-induced DNA damage in mouse and human fibroblasts in vitro. Thus, we have identified DNA damage reduction as a novel mechanism by which rapamycin can prevent cancer, which could lay the foundation for its use as a cancer prevention agent in selected human populations.

Connexin 43 channels are essential for normal bone structure and osteocyte viability

Connexin (Cx) 43 serves important roles in bone function and development. Targeted deletion of Cx43 in osteoblasts or osteocytes leads to increased osteocyte apoptosis, osteoclast recruitment, and reduced biomechanical properties. Cx43 forms both gap junction channels and hemichannels, which mediate the communication between adjacent cells or between cell and extracellular environments, respectively. Two transgenic mouse models driven by a DMP1 promoter with the overexpression of dominant negative Cx43 mutants were generated to dissect the functional contribution of Cx43 gap junction channels and hemichannels in osteocytes. The R76W mutant blocks the gap junction channel, but not the hemichannel function, and the Δ130-136 mutant inhibits activity of both types of channels. Δ130-136 mice showed a significant increase in bone mineral density compared to wild-type (WT) and R76W mice. Micro-computed tomography (µCT) analyses revealed a significant increase in total tissue and bone area in midshaft cortical bone of Δ130-136 mice. The bone marrow cavity was expanded, whereas the cortical thickness was increased and associated with increased bone formation along the periosteal area. However, there is no significant alteration in the structure of trabecular bone. Histologic sections of the midshaft showed increased apoptotic osteocytes in Δ130-136, but not in WT and R76W, mice which correlated with altered biomechanical and estimated bone material properties. Osteoclasts were increased along the endocortical surface in both transgenic mice with a greater effect in Δ130-136 mice that likely contributed to the increased marrow cavity. Interestingly, the overall expression of serum bone formation and resorption markers were higher in R76W mice. These findings suggest that osteocytic Cx43 channels play distinctive roles in the bone; hemichannels play a dominant role in regulating osteocyte survival, endocortical bone resorption, and periosteal apposition, and gap junction communication is involved in the process of bone remodeling.

Caspase-2 maintains bone homeostasis by inducing apoptosis of oxidatively-damaged osteoclasts

Osteoporosis is a silent disease, characterized by a porous bone micro-structure that enhances risk for fractures and associated disabilities. Senile, or age-related osteoporosis (SO), affects both men and women, resulting in increased morbidity and mortality. However, cellular and molecular mechanisms underlying senile osteoporosis are not fully known. Recent studies implicate the accumulation of reactive oxygen species (ROS) and increased oxidative stress as key factors in SO. Herein, we show that loss of caspase-2, a cysteine aspartate protease involved in oxidative stress-induced apoptosis, results in total body and femoral bone loss in aged mice (20% decrease in bone mineral density), and an increase in bone fragility (30% decrease in fracture strength). Importantly, we demonstrate that genetic ablation or selective inhibition of caspase-2 using zVDVAD-fmk results in increased numbers of bone-resorbing osteoclasts and enhanced tartrate-resistant acid phosphatase (TRAP) activity. Conversely, transfection of osteoclast precursors with wild type caspase-2 but not an enzymatic mutant, results in a decrease in TRAP activity. We demonstrate that caspase-2 expression is induced in osteoclasts treated with oxidants such as hydrogen peroxide and that loss of caspase-2 enhances resistance to oxidants, as measured by TRAP activity, and decreases oxidative stress-induced apoptosis of osteoclasts. Moreover, oxidative stress, quantified by assessment of the lipid peroxidation marker, 4-HNE, is increased in Casp2^-/- bone, perhaps due to a decrease in antioxidant enzymes such as SOD2. Taken together, our data point to a critical and novel role for caspase-2 in maintaining bone homeostasis by modulating ROS levels and osteoclast apoptosis during conditions of enhanced oxidative stress that occur during aging.

Antibody neutralization of vascular endothelial growth factor inhibits wound granulation tissue formation

OBJECTIVE

The goal of this work was to test the functional role of vascular endothelial growth factor (VEGF) in promoting the vigorous granulation tissue formation, wound fluid accumulation, and angiogenic responses characteristic of this wound model.

BACKGROUND

Formation of vessel-rich granulation tissue is central to wound repair and is thought to be regulated by locally liberated angiogenic factors. Despite the clinical importance of granulation tissue formation in the early stage of wound healing, surprisingly little is known about the molecular identity of signals leading to granulation tissue invasion of a wound space. Methods. A ventral hernia, surgically created in the abdominal wall of 15 swine, was repaired using silicone sheeting and skin closure. An osmotic minipump, inserted in a remote subcutaneous pocket, delivered saline (n = 5), an irrelevant control antibody (n = 5), or neutralizing anti-VEGF antibody (n = 5) into the wound environment. Serial ultrasonography on Days 2, 4, 7, 9, 11, and 14 was used to determine the dimensions of the subcutaneous granulation tissue and wound fluid compartment. VEGF and transforming growth factor beta1 (TGF-beta1) levels in serial wound fluid samples were quantitated by ELISA. On Day 14, animals were sacrificed and the abdominal wall was harvested for histologic, biochemical, and molecular analyses.

RESULTS

In animals receiving saline or an irrelevant antibody, a nearly linear 4-fold increase in granulation tissue thickness and 7-fold increase in wound fluid volume were measured over the 14-day study interval. In contrast, in animals receiving anti-VEGF neutralizing antibody, Day 14 granulation tissue thickness and wound fluid volume measurements were essentially unchanged from Day 2 values. Moreover, in the anti-VEGF animals, ultrasonography was unable to resolve the "angiogenic zone" typical of both controls, and correspondingly, wound vessel count and vascular surface area estimates derived from image analysis of histological sections were 3-fold lower in the anti-VEGF animals compared with the saline and antibody controls. Finally, VEGF levels in wound fluid detectable by ELISA analysis were strikingly (10-fold) reduced in anti-VEGF animals on Postsurgery Days 7-14. In contrast, TGF-beta1 levels were unaffected by the anti-VEGF treatment.

CONCLUSION

Functional VEGF is a key mediator in wound angiogenesis, fluid accumulation, and granulation tissue formation.

Nitric oxide synthase isoform expression in a porcine model of granulation tissue formation

BACKGROUND

This study was designed to determine whether the nitric oxide (NO) pathway is involved in wound granulation tissue formation.

METHODS

A section of the pig abdominal wall (excluding the skin) was excised, creating an incisional hernia. The resulting defect was repaired with silicone sheeting in a manner that mimics a temporary abdominal wall closure. During the 14-day experimental period, porcine omentum adhered to the peritoneal edges of the defect and a highly vascularized granulation tissue formed on both sides of the sheeting. Granulation tissue thickness and wound fluid volume were monitored by ultrasonography and epigastric artery flow velocity was monitored by color Doppler flow analysis at days 2, 4, 7, 9, 11, and 14. Fluid was serially harvested from the wound compartment at days 2, 4, 7, 9, 11, and 14 for nitrite/ nitrate (NOx) analysis. Finally, granulation tissue was harvested at day 14 for immunohistochemical and molecular analyses.

RESULTS

There was a significant increase in granulation tissue thickness and wound fluid volume during the 14-day study period. Blood flow to the wound increased significantly by day 4 and returned toward baseline by day 14. Wound fluid NOx levels significantly increased from days 7 to 11 and then decreased to near baseline values by day 14. Wound fluid arginine levels significantly decreased when compared with peritoneal fluid and plasma levels at day 14, while wound fluid ornithine levels significantly increased. Immunohistochemical analysis of granulation tissue at day 14 revealed nitric oxide synthase (NOS) 2 was present in the majority of the cells in the granulation tissue. NOS 3 was expressed in endothelial cells only, and NOS 1 expression was not observed in the granulation tissue.

CONCLUSIONS

This study suggests that NO, NOS 2, and arginine may play critical roles in granulation tissue formation and wound healing. Arginase and NOS 2 may compete for available arginine as a substrate, thereby limiting later NO production in favor of sustained ornithine synthesis.

Normoxic wound fluid contains high levels of vascular endothelial growth factor

OBJECTIVE

To examine the temporal integration of vascular endothelial growth factor (VEGF), which has been shown to be present in wound fluid, with the putatively related processes of wound fluid oxygen content, wound angiogenesis, and granulation tissue formation.

SUMMARY BACKGROUND DATA

During cutaneous wound repair, new tissue formation starts with reepithelialization and is followed by granulation tissue formation, including neutrophil and macrophage accumulation, fibroblast ingrowth, matrix deposition, and angiogenesis. Because angiogenesis and increased vascular permeability are characteristic features of wound healing, VEGF may play an important role in tissue repair.

METHODS

A ventral hernia, surgically created in the abdominal wall of female swine, was repaired using silicone sheeting and skin closure. Over time, a fluid-filled wound compartment formed, bounded by subcutaneous tissue and omentum. Ultrasonography was performed serially to examine the anatomy and dimensions of the subcutaneous tissue and wound compartment. Serial wound fluid samples, obtained by percutaneous aspiration, were analyzed for PO2, PCO2, pH, and growth factor concentrations.

RESULTS

Three independent assays demonstrate that VEGF protein is present at substantially elevated levels in a wound fluid associated with the formation of abdominal granulation tissue. However, the wound fluid is not hypoxic at any time. Serial sampling reveals that transforming growth factor beta-1 protein appears in the wound fluid before VEGF.

CONCLUSIONS

The results suggest that VEGF is a prominent regulator of wound angiogenesis and vessel permeability. A factor other than hypoxia, perhaps the earlier appearance of another growth factor, transforming growth factor beta-1, may positively regulate VEGF appearance in the wound fluid.

Studies in burns. XIII. Effects of a topical lipid on burned subjects and their wounds

We evaluated ethyl linoleate (ethyl, (9, 12)-cic, cis-octadecadienoate), a naturally occurring cutaneous water-holding lipid, for its water-holding metabolic, healing and toxic properties in groups of unburned and burned rabbits and its toxic potentials in this species and mice. The lipid appears to reduce evaporative water loss in full-thickness burned rabbits. Associated with this effect is a proportional and related lowering of metabolic heat production. The topical application of the lipid at any time after burn appears to be associated with a significant healing in lesions that, histologically at least, would be interpreted as fullthickness. The material is highly toxic if applied daily to mice or rabbits. The details of the toxic effect (s) are being studied. The commerical-grade material (75 percent pure) contains a derivative of ricinoleci acid and chronic exposure of the EL to air may result in the formation of peroxides and epoxides. These materials exert well-defined toxicity. The obvious potential uses of this agent in treating human burn lesions need not be emphasized, but it does need to be stated categorically that, at present, (Feb 1974), the toxicity has not been defined enough for use except in experiments.