Relationships in Shark Skin: Mechanical and Morphological Properties Vary between Sexes and among Species.

Shark skin is a composite of mineralized dermal denticles embedded in an internal collagen fiber network and is sexually dimorphic. Female shark skin is thicker, has greater denticle density and denticle overlap compared to male shark skin, and denticle morphology differs between sexes. The skin behaves with mechanical anisotropy, extending farther when tested along the longitudinal (anteroposterior) axis but increasing in stiffness along the hoop (dorsoventral or circumferential) axis.

Breaking boundaries through Doctors Reaching Minority Men Exploring Neuroscience: a mentorship model to foster a pipeline for underrepresented minorities.

Objective: In 2015, the Association of American Medical Colleges report titled "Altering the Course: Black Males in Medicine" showed a decline in the number of Black men matriculating into medical school. To alter this trend, the authors' hypothesis was that formally exposing Black men to the clinical neurosciences during high school would enhance their chances of entering the physician workforce. For this reason, in 2007, the Doctors Reaching Minority Men Exploring Neuroscience (DR.

Nicotine Exposure in the U.S. Population: Total Urinary Nicotine Biomarkers in NHANES 2015-2016.

We characterize nicotine exposure in the U.S. population by measuring urinary nicotine and its major (cotinine, trans-3′-hydroxycotinine) and minor (nicotine 1′-oxide, cotinine N-oxide, and 1-(3-pyridyl)-1-butanol-4-carboxylic acid, nornicotine) metabolites in participants from the 2015−2016 National Health and Nutrition Examination Survey.

Selenium detoxification is required for cancer-cell survival.

The micronutrient selenium is incorporated via the selenocysteine biosynthesis pathway into the rare amino acid selenocysteine, which is required in selenoproteins such as glutathione peroxidases and thioredoxin reductases. Here, we show that selenophosphate synthetase 2 (SEPHS2), an enzyme in the selenocysteine biosynthesis pathway, is essential for survival of cancer, but not normal, cells. SEPHS2 is required in cancer cells to detoxify selenide, an intermediate that is formed during selenocysteine biosynthesis.

High Levels of Residue within Polymeric Hollow Fiber Membranes Used for Blood Oxygenation.

A number of research teams are developing surface coatings for hollow fiber membrane (HFM) blood oxygenators to improve their biocompatibility and service life. Surface coating techniques can be quite sensitive to the presence of contaminants on the exterior surface of the hollow fibers. We found large amounts of leachable oils associated with several commercial HFMs, i.

Survey of primary care physicians on therapeutic approaches to lung and breast cancers.

Background: Primary care physicians (PCPs) are an important part of the decision-making process in the care of patients with cancer. The survey discussed herein evaluates what percentage of academic and community PCPs recognize benefits from systemic therapy in lung and breast cancers.

Methods: PCPs were surveyed regarding their beliefs toward systemic therapy in early- and late-stage lung and breast cancers and were asked to rate the importance of specific factors that influence their referral decisions.

Variations in the gender composition of immigrant populations: how they matter.

This paper estimates and interprets empirical shifts in the gender composition of immigrants to add to scholarship about the gendering of international migrations over time. We map shifts in gender ratios using micro-level data that permit us to create age-standardized estimates among adult foreign born stock living in the United States since 1850 and in 26 other nations worldwide since 1960. We examine regional and national variations in these shifts, and ask whether and how the gendered composition of foreigners from diverse origins in the United States – the nation that has received the largest populations of migrants for over a century – differs from other nations that receive large numbers of immigrants.

Predictive value of BI-RADS classification for breast imaging in women under age 50.

In this study, we assessed the positive-predictive value (PPV) of mammography and/or ultrasonography in women age 50 based on recommendations for biopsies and final pathology results. We performed a retrospective analysis of all mammography and ultrasonography reports issued from 9/2005 to 1/2007 resulting in biopsy among women aged 18-50 at a large county hospital. Data included demographics, imaging modality, breast density, type of finding, BI-RADS, and final pathology.

Time course of nicotine and cotinine incorporation into samples of nonsmokers' beard hair following a single dose of nicotine polacrilex.

Hair nicotine and cotinine have been proposed as longer-term markers of exposure to secondhand smoke. In this study, we evaluated the rate and extent of nicotine and cotinine deposition into beard hair among six male nonsmokers following a single exposure to 4 mg of nicotine in Nicorette(®) (nicotine polacrilex) gum. We collected beard hair samples daily for 12 days following exposure and urine samples for 6 days after exposure.

Ovine smoke/burn ARDS model: a new ventilator-controlled smoke delivery system.

Background: Our current ovine smoke/burn acute respiratory distress syndrome (ARDS) model utilizes a manual bee smoker. This smoke delivery system lacks standardization and reproducibility, with 20% of sheep failing to meet ARDS criteria. Time to reach ARDS criteria and survival time are also variable.

Indications for circumferential surgery for cervical spondylotic myelopathy.

Background Context: The surgical management of patients with cervical spondylotic myelopathy (CSM) remains challenging.

Purpose: To review the indications, techniques, and results of circumferential fusion for CSM.

Conclusion: Circumferential decompression and stabilization with instrumentation is a viable option to treat selected complex cervical spine disorders.

The Premature Ejaculation Prevalence and Attitudes (PEPA) survey: prevalence, comorbidities, and professional help-seeking.

Objectives: This study evaluated the associated comorbidities and patient satisfaction with treatment options for premature ejaculation (PE), a common sexual dysfunction.

Methods: A comprehensive, Internet-based survey (the PE Prevalence and Attitudes [PEPA] survey) was conducted among men ages 18-70 in the United States, Germany, and Italy (n=12,133). Men were classified as having PE based on self-report of low or absent control over ejaculation, resulting in distress for them or their sexual partner or both.

Large-scale purification and characterization of human parathyroid hormone-1 receptor stably expressed in HEK293S GnTI- cells.

Human parathyroid hormone-1 receptor (hPTHR1) belongs to class II of the G protein-coupled receptor (GPCR) family, whose members all contain a seven-transmembrane helix domain. The receptor regulates bone metabolism through interactions with its ligand, human parathyroid hormone (hPTH). For structural studies of the hPTHR1/hPTH complex, we constructed a mammalian cell line to stably express recombinant hPTHR1 in large-scale.

Backbone dynamics of human parathyroid hormone (1-34): flexibility of the central region under different environmental conditions.

The presence of a stable tertiary structure in the bioactive N-terminal portion of parathyroid hormone (PTH), a major hormone in the maintenance of extracellular calcium homeostasis, is still debated. In this work, 15N relaxation parameters of the 33 backbone amides of human PTH(1-34) were determined in phosphate-buffered saline solution (PBS) and in the presence of dodecylphosphocholine (DPC) micelles. The relaxation parameters were analyzed using both the model-free formalism (G.

Effects of embryo culture on angiogenesis and morphometry of bovine placentas during early gestation.

The objective of this study was to determine the effects of undefined and semidefined culture systems for in vitro embryo production on angiogenesis and morphometry of bovine placentas during early gestation. Blastocysts produced in vivo were recovered from superovulated Holstein cows and served as controls. Blastocysts produced in vitro were exposed to either serum-supplemented medium with cumulus cell coculture (in vitro-produced with serum; IVPS) or modified synthetic oviductal fluid medium without serum or coculture (mSOF).

Novel bioabsorbable interbody fusion spacer-assisted fusion for correction of spinal deformity.

Object: The authors report the cases of 12 patients with medically refractory mechanical low-back pain and intermittent radicular symptoms in whom radiography demonstrated evidence of multilevel lumbosacral degenerative kyphotic and scoliotic deformity and spondylolisthesis.

Methods: These patients underwent multilevel posterior lumbar interbody fusion in which Macropore bioabsorbable spacers were placed. Each patient underwent at least 1 year of clinical and radiographic follow up.

Cervical osteomyelitis: a brief review.

Object: The authors conducted a literature-based review of the etiology, diagnosis, and treatment of cervical vertebral osteomyelitis (CVO).

Methods: A Medline (PubMed) search using the key words "cervical vertebral osteomyelitis" yielded 256 articles. These were further screened for relevance, yielding 15 articles.

Postoperative Level 1 anticoagulation therapy and spinal surgery: practical guidelines for management.

Object: The authors conducted a review of the literature to establish reasonable practical guidelines for the management of complications in patients who have undergone recent spinal surgery and who require Level 1 anticoagulation therapy.

Methods: A MEDLINE (PubMed) literature search was performed using the key words "postoperative anticoagulation," "spinal surgery," and "postoperative epidural hematoma," for articles published between 1990 and 2004. The search yielded 148 articles, which were then further screened for relevance and classified according to level-of-evidence guidelines established by the American Association of Neurological Surgeons/Congress of Neurological Surgeons joint committee for spinal cord injury.

Differential transcriptional effects of PTH and estrogen during anabolic bone formation.

The aim of this study was to compare transcriptional regulation in vivo during anabolic bone formation induced by either estradiol (E2) treatment or intermittent parathyroid hormone[1-34] (PTH) therapy. We utilized an ovariectomized (OVX) mouse model of osteoporosis and transcriptional profiling to identify genes upregulated by either high-dose E2 or PTH. Five weeks post-OVX, the mice were administered either E2 and/or PTH, or vehicle for 4 weeks.

Posterior lumbar interbody fusion using recombinant human bone morphogenetic protein type 2 with cylindrical interbody cages.

Background Context: In a large series of human patients undergoing open anterior lumbar interbody fusion with a tapered titanium fusion cage, recombinant human bone morphogenetic protein type 2 (rhBMP-2) on an absorbable collagen sponge carrier has been shown to decrease operative time and blood loss, to promote osteoinduction and fusion and to be a safe and effective substitute for iliac crest harvesting.

Purpose: The purpose of the study was to determine the clinical and radiographic outcomes in patients treated for single-level degenerative lumbar disc disease with a posterior interbody fusion, using stand-alone cylindrical threaded titanium fusion cages with either autogenous bone graft or rhBMP-2 and an absorbable collagen sponge carrier.

Study Design/setting: A prospective, randomized, nonblinded, 2-year pilot study at 14 investigational sites.

Angiogenesis and morphometry of bovine placentas in late gestation from embryos produced in vivo or in vitro.

The objective of this study was to determine the effects of in vitro embryo production on angiogenesis and morphometry of the bovine placenta during late gestation. Blastocysts produced in vivo were recovered from superovulated Holstein cows. Blastocysts produced in vitro were obtained after culture of in vitro-matured and -fertilized Holstein oocytes.

Transcriptional regulation of the human Runx2/Cbfa1 gene promoter by bone morphogenetic protein-7.

It is well established that core binding factor Runx2/Cbfa1 is required for osteoblast recruitment and differentiation from mesenchymal stem cells. Transcriptional regulation of the Runx2/Cbfa1 gene by osteogenic factors such as bone morphogenetic proteins (BMPs) plays an important role in the stimulation of bone formation by these cytokines. BMP7 (also termed OP-1) is a member of the transforming growth factor beta (TGF-beta) superfamily and induces osteoblast differentiation from mesenchymal precursor stem cells in vitro as well as bone formation in vivo.

Does simvastatin stimulate bone formation in vivo?

Background: Statins, potent compounds that inhibit cholesterol synthesis in the liver have been reported to induce bone formation, both in tissue culture and in rats and mice. To re-examine potential anabolic effects of statins on bone formation, we compared the activity of simvastatin (SVS) to the known anabolic effects of PTH in an established model of ovariectomized (OVX) Swiss-Webster mice.

Methods: Mice were ovariectomized at 12 weeks of age (T0), remained untreated for 5 weeks to allow development of osteopenia (T5), followed by treatment for 8 weeks (T13).

Applications of a resorbable interbody spacer in posterior lumbar interbody fusion.

Polyhydroxy acids are a promising class of resorbable materials with potential applications in spinal surgery. One such polymer, MacroPore (MacroPore Biosurgery, Inc.), offers a balance of strength, predictable degradation, lack of stimulus of foreign body reaction, and biocompatibility with neural tissue.

Applications of a resorbable interbody spacer via a posterior lumbar interbody fusion technique.

Polyhydroxyacids are a promising class of bioresorbable materials withpotential applications in spinal surgery. One such polymer, MacroPore (MacroPore Biosurgery Inc, San Diego, Calif), offers a balance of strength, predictable degradation, lack of stimulus of foreign body reaction, and biocompatibility with neural tissue. MacroPore can be formed into an array of shapes and can be manufactured, sterilized, and stored with conventional techniques.