The Influence of Vitamin D Metabolism on Gene Expression, Matrix Production and Mineralization During Osteoprecursor Cell-Based Bone Development.

BACKGROUND: Multipotential precursor cell lines derived from human bone marrow, capable of differentiating into cartilage or bone, may provide a useful tissue development model for studying the regulation and metabolism of putative growth and differentiation factors necessary for tissue regeneration. In mammals, the process of bone development depends on the proliferation and differentiation of osteoblast lineage cells, and the subsequent synthesis and mineralization of bone extracellular matrix (ECM). Vitamin D metabolites play a pivotal role in bone and mineral homeostasis, and are positive factors on bone development. Recently, it was demonstrated that a human-derived engineered osteoblast precursor cell line (OPC1), derived from human bone marrow, can metabolize the parental precursor vitamin D3 (vitaD3) to the active steroid 1α,25-dihydroxyvitamin D3 (1,25OH2D3), and elicit an osteogenic response that results in the decrease in proliferation and increase in ECM synthesis during early bone development. The aim in this study is to characterize gene expression, matrix production and mineralization within a bone development model. METHODS: We investigated whether vitaD3 influences bone ECM mineralization in the same manner as 1,25OH2D3 in confluent cultures of OPC1s. In addition, we explored the influence of vitamin D metabolites, in combination with other commonly used osteogenic factors, ascorbic acid, ß-glycerophosphate, dexamethasone (dex) and recombinant human bone morphogenetic protein-2 (rhBMP-2) on the osteoinduction of OPC1. RESULTS: It was demonstrated that OPC1 expresses the mRNA for the enzymatic equipment necessary to convert vitaD3 to 1,25OH2D3, as well as the mRNA expression of the catabolic enzyme known to regulate the concentration of active 1,25OH2D3. It was also demonstrated that mRNA expression for the vitamin D receptor (VDR) was influenced by both vitaD3 and 1,25OH2D3. Differential results using vitamin D metabolites in combination with ascorbic acid, ß-glycerophosphate, dex and/or rhBMP-2 were observed in alkaline phosphatase (ALP) activity and calcium deposition, and mRNA expression of procollagen type I (proColI), osteocalcin (OC) and osteopontin (OP). CONCLUSIONS: Overall it was demonstrated that vitamin D in combination with osteogenic factors influences the temporal bone development sequence in a positive manner.

Extrahepatic 25-Hydroxylation of Vitamin D3 in an Engineered Osteoblast Precursor Cell Line Exploring the Influence on Cellular Proliferation and Matrix Maturation during Bone Development.

Osteoblastic precursors experience distinct stages during differentiation and bone development, which include proliferation, extracellular matrix (ECM) maturation, and ECM mineralization. It is well known that vitamin D plays a large role in the regulation of bone mineralization and homeostasis via the endocrine system. The activation of vitamin D requires two sequential hydroxylation steps, first in the kidney and then in the liver, in order to carry out its role in calcium homeostasis. Recent research has demonstrated that human-derived mesenchymal stem cells (MSCs) and osteoblasts can metabolize the immediate vitamin D precursor 25-dihydroxyvitamin D3 (25OHD3) to the active steroid lα,25-dihydroxyvitamin D3 (1,25OH2D3) and elicit an osteogenic response. However, reports of extrahepatic metabolism of vitamin D3, the parental vitamin D precursor, have been limited. In this study, we investigated whether osteoblast precursors have the capacity to convert vitamin D3 to 1,25OH2D3 and examined the potential of vitamin D3 to induce 1,25OH2D3 associated biological activities in osteoblast precursors. It was demonstrated that the engineered osteoblast precursor derived from human marrow (OPC1) is capable of metabolizing vitamin D3 to 1,25OH2D3 in a dose-dependent manner. It was also demonstrated that administration of vitamin D3 leads to the increase in alkaline phosphatase (ALP) activity associated with osteoblast ECM maturation and calcium deposits and a decrease in cellular proliferation in both osteoblast precursor cell lines 0PC1 andOMC3T3-E1. These findings provide a two-dimensional culture foundation for future three-dimensional engineered tissue studies using the OPC1 cell line.

Ultrasonic wave propagation assessment of native cartilage explants and hydrogel scaffolds for tissue engineering.

Non-destructive techniques characterising the mechanical properties of cells, tissues, and biomaterials provide baseline metrics for tissue engineering design. Ultrasonic wave propagation and attenuation has previously demonstrated the dynamics of extracellular matrix synthesis in chondrocyte-seeded hydrogel constructs. In this paper, we describe an ultrasonic method to analyse two of the construct elements used to engineer articular cartilage in real-time, native cartilage explants and an agarose biomaterial. Results indicated a similarity in wave propagation velocity ranges for both longitudinal (1500-1745 m/s) and transverse (350-950 m/s) waveforms. Future work will apply an acoustoelastic analysis to distinguish between the fluid and solid properties including the cell and matrix biokinetics as a validation of previous mathematical models.

Three-Dimensional Culture of Cells and Matrix Biomolecules for Engineered Tissue Development and Biokinetics Model Validation.

There has been considerable progress in cellular and molecular engineering due to recent advances in multiscale technology. Such technologies allow controlled manipulation of physiochemical interactions among cells in tissue culture. In particular, a novel chemomechanical bioreactor has recently been designed for the study of bone and cartilage tissue development, with particular focus on extracellular matrix formation. The bioreactor is equally significant as a tool for validation of mathematical models that explore biokinetic regulatory thresholds (Saha, A. K., and Kohles, S. S., 2010, "A Distinct Catabolic to Anabolic Threshold Due to Single-Cell Nanomechanical Stimulation in a Cartilage Biokinetics Model," J. Nanotechnol. Eng. Med., 1(3), p. 031005; 2010, "Periodic Nanomechanical Stimulation in a Biokinetics Model Identifying Anabolic and Catabolic Pathways Associated With Cartilage Matrix Homeostasis," J. Nanotechnol. Eng. Med., 1(4), p. 041001). In the current study, three-dimensional culture protocols are described for maintaining the cellular and biomolecular constituents within defined parameters. Preliminary validation of the bioreactor's form and function, expected bioassays of the resulting matrix components, and application to biokinetic models are described. This approach provides a framework for future detailed explorations combining multiscale experimental and mathematical analyses, at nanoscale sensitivity, to describe cell and biomolecule dynamics in different environmental regimes.

A Multivariate Logistical Model for Identifying the Compressive Sensitivity of Single Rat Tactile Receptors as Nanobiosensors.

Tactile sensation is a complex manifestation of mechanical stimuli applied to the skin. At the most fundamental level of the somatosensory system is the cutaneous mechanoreceptor. The objective here was to establish a framework for modeling afferent mechanoreceptor behavior as a nanoscale biosensor under dynamic compressive loads using multivariate regression techniques. A multivariate logistical model was chosen because the system contains continuous input variables and a singular binary-output variable corresponding to the nerve action potential. Subsequently, this method was used to quantify the sensitivity of ten rapidly adapting afferents from rat hairy skin due to the stimulus metrics of compressive stress, strain, their respective time derivatives, and interactions. In vitro experiments involving compressive stimulation of isolated afferents using pseudorandom and nonrepeating noise sequences were completed. An analysis of the data was performed using multivariate logistical regression producing odds ratios (ORs) as a metric associated with mechanotransduction. It was determined that cutaneous mechanoreceptors are preferentially sensitive to stress (mean OR(max) = 26.10), stress rate (mean OR(max) = 15.03), strain (mean OR(max) = 12.01), and strain rate (mean OR(max) = 7.29) typically occurring within 7.3 ms of the nerve response. As a novel approach to receptor characterization, this analytical framework was validated for the multiple-input, binary-output neural system.

Revolutionary advances in enhancing patient comfort on patients transported on a backboard.

BACKGROUND: Patients with suspected spinal cord injuries are immobilized to a backboard during ambulance and helicopter air transport. It has been well documented that patients who are immobilized to a backboard experience discomfort and eventually become susceptible to pressure ulcer formation. Because the patient lying on a backboard is subjected to high skin interface pressures, it is imperative to improve patient comfort and prevent pressure ulcer formation. OBJECTIVE: Realizing the dangers of the potentially preventable pressure ulcers, our team of scientists, surgeons, and trauma nurses performed a comprehensive study of the Back Raft system that was designed to reduce patient discomfort and skin interface pressure. METHODS: Pressure under the occipital, scapula, and sacral regions of the back was measured using the Tactilus pressure analyzer of 10 healthy volunteers immobilized on a backboard and a backboard with a Back Raft air mattress system. Discomfort levels of each volunteer were measured using a Visual Analog Scale. RESULTS: Data from this study indicated that the Back Raft significantly reduces discomfort as well as tissue interface pressure in the occipital, scapula, and sacral regions of the back. CONCLUSIONS: The implementation of an air mattress system analogous to the Back Raft would facilitate the prevention of pressure ulcer formation during prehospital care and transportation. In 2008, The Centers for Medicare and Medicaid Services enacted a policy in which the Centers for Medicare and Medicaid Services can refuse payment for hospital-acquired conditions. Pressure ulcers were among the hospital-acquired conditions within the final rule.

A need for reorganization of the Food and Drug Administration.

The associate director for science and medicine in the Office of Drug Safety at the Food and Drug Administration (FDA), Dr. David Graham, reported that the FDA was incapable of protecting Americans from unsafe drugs. In testimony to the Senate Finance Committee, he stated that the FDA has let the American people down and betrayed public trust. Drastic changes and measures within the FDA must be made to ensure the safety of American consumers of drugs, products, and medical devices. Efforts such as the introduction of the Grassley-Dodd Bill, allowing the FDA to order immediate drug recall or increased risk warnings, followed by the FDA Safety Act of 2007, are still not enough to ensure the safety and efficacy of drugs, biological products, and medical devices that the American public use every day. In this report, we describe past and present efforts by congressional leaders, FDA representatives, and American citizens to effect changes within the FDA in order to protect America from unsafe drugs and medical devices. We describe our own struggles in passing a citizen’s petition to ban cornstarch in medical gloves, and the lack of response and responsibility that the FDA has displayed.

Revolutionary advances in the diagnosis of vitamin D deficiency.

Vitamin D deficiency has bee associated with bone diseases, cardiovascular diseases, cancer, and multiple sclerosis. Recent clinical studies have pointed out that these diseases could be prevented by either adequate sun exposure or oral vitamin D3 supplementation. In an effort to prevent these illnesses, emergency physicians and other clinicians must be aware of technological advances in the measurement of serum concentrations of 25-hydroxyvitamin D. Realizing the importance of diagnosing vitamin D deficiency, we reviewed the following advanced diagnostic techniques: liquid chromatography tandem mass spectrometry, radioimmunoassay, and DiaSorin's immunochemiluminometric automated analyzer LIASION®. On the basis of this review, we have found that each of these diagnostic tests has documented limitations, and therefore we recommend an international standardization of these assays to accurately diagnose vitamin D deficiency.

An innovative advance in continuing medical education for emergency physicians and trauma surgeons.

OBJECTIVE: For the past two years, we have tried to devise, unsuccessfully, a manual for physician's assistants and residents. The manual was not completed because we did not have a comprehensive field triage plan for injured patients. METHODS: A landmark publication written by members of the National Center for Injury Prevention and Control of the CDC provided comprehensive and detailed information on field triage of injured patients. This work has ten continuing education questions allowing the reader to receive 2.5 CME credits. RESULTS: The format for this work will provide an outline for future manuals in emergency departments and trauma centers. CONCLUSION: All emergency physicians and trauma surgeons should review this work to ensure that their community has an updated field triage plan for emergency and trauma patients.

A case report: femoral fracture in a multiple sclerosis patient with vitamin d deficiency--a preventable injury.

In this report, we describe the management of a multiple sclerosis patient with a femoral fracture who had severe vitamin D deficiency. After the patient's preoperative laboratory studies revealed a normal platelet count, the orthopedic surgeon performed an intramedullary rod fixation on the patient's left femoral fracture. After the surgery, the diagnosis of vitamin D deficiency was made by measuring the circulating serum concentration of 25-dihydroxyvita-min D (25(OH)D) via Disorin's Vitamin D immunochemiluminometric assay LIASION by LabCorp (Laboratory Corporation of America). The patient's postoperative management included the oral administration of 4000 IU of vitamin D3 in a gel-cap suspension that resulted in an elevation of the blood serum concentration of 25(OH)D to an optimal concentration of >80 nmol/L (32 ng/ml).

Nursing home fractures: a challenge and a solution.

Hip fracture occurrences in nursing homes are associated with high morbidity, mortality, and high health care costs in elderly people. In the United States, approximately 340,000 hip fractures occur each year, while more then 90% are associated with falls. Osteoporosis is a skeletal disorder causing impaired bone strength that increases the risk of fracture. In the United States alone, osteoporosis affects < 10 million individuals aged > or =50. The American Association of Clinical Endocrinologists (AACE), North American Menopause Society (NAMS), and National Osteoporosis Foundation (NOF) have developed recommendations for the identification of patients with osteoporosis who need therapy. Good nutrition with adequate supplements of calcium and vitamin D3 is considered one of the most important lifestyle factors for maintaining adequate bone mineral density. Only a combination of calcium and vitamin D therapy has been shown to increase the bone mineral density as well as a reduction in the nonvertebral fractures.

Residual urinary volume and urinary tract infection, a life threatening illness: a case report.

Multiple Sclerosis (MS) is an inflammatory disease that demyelinates the central nervous system causing progressive disability. The urodynamics of MS patients is an important consideration because these patients are susceptible to acute urinary bladder retention associated with a high fever. Treatment should include irrigation using a Foley catheter and an irrigation syringe to remove residual urine and sediment from the neurogenic bladder, intravenous fluid resuscitation, bacteriological analysis of the residual urine, and admission to an Intensive Care Unit for further evaluation by a urologist. After discharge, suprapubic cystostomy should be a consideration for patients who have chronic urinary tract infections associated with acute urinary bladder retention, as well as limited mobility to perform self catheterization, or limited personal care assistants trained to perform a urethral clean intermittent catheterization.

Revolutionary advances in the management of traumatic wounds in the emergency department during the last 40 years: part I.

BACKGROUND AND OBJECTIVES: This report provides an overview of advances in wound repair devised by our research team during the last four decades. This collective review is presented in two parts. DISCUSSION: The following components are included in Part I: 1) search and treat life-threatening trauma; 2) conduct a thorough history; 3) examine the wound using aseptic technique; 4) anesthetize the wound before cleansing; 5) hair removal, skin disinfection, hemostasis, surgical debridement, and mechanical cleansing; 6) antibiotics, drains, and open wound management. CONCLUSION: On the basis of these comprehensive research studies, we have noted a marked reduction in the incidence of wound infection in traumatic wounds.

Revolutionary advances in the management of traumatic wounds in the emergency department during the last 40 years: part II.

BACKGROUND AND OBJECTIVES: During the last four decades, our research team has devised advances in wound repair that are highlighted in Part II of this collective review. DISCUSSION: There are several different methods to provide an accurate and secure approximation of the skin edges-sutures, tapes, staples, and tissue adhesives. Ideally, the selection of the wound closure technique will be based on the biologic interaction of the materials employed, tissue configuration, and biomechanical properties of the trauma wound. Selection of the appropriate wound dressing is another important consideration in the management of the trauma wound. CONCLUSION: On the basis of the comprehensive research and clinical studies, we have individualized the wound closure techniques for traumatic wounds so that healing can be achieved with more aesthetically pleasing scars.

Scientific documentation of the relationship of vitamin D deficiency and the development of cancer.

It is well known that vitamin D plays a key role in calcium homeostasis and is important for optimal skeletal growth. The major function of vitamin D is to enhance the efficiency of calcium absorption from the small intestine. Most physicians relate vitamin D deficiency to disorders of skeletal muscle. Vitamin D deficiency in children can manifest itself as rickets. In adults, vitamin D deficiency results in osteomalacia. Because most physicians do not appreciate the role of vitamin D deficiency in predisposing the development of cancer, we have written this important report as a wake-up call to physicians and other healthcare workers in documenting the relationship of vitamin D deficiency and cancer. Epidemiological data show an inverse relationship between vitamin D levels and breast cancer incidence. In addition, there is a well-documented association between vitamin D intake and the risk of breast cancer. Low vitamin D intake has also been indicated in colorectal carcinogenesis. A vitamin D deficiency has also been documented in patients with prostate cancer, ovarian cancer, as well as multiple myeloma. Larger randomized clinical trials should be undertaken in humans to establish the role of vitamin D supplementation in the prevention of these cancers.

Revolutionary advances in the prevention of demyelinating diseases.

This collective review focuses on three major factors that influence the incidences of multiple sclerosis (MS) to include ultraviolet radiation (UVR), vitamin D3 supplementation, and vitamin D receptor gene (VDRG) polymorphisms. In general, the rate of MS increases with latitude. Individuals tend to carry their original risk with them if they migrate to a different latitude after adolescence. It is important to emphasize that UVR increases the synthesis of vitamin D3, which has a known immune suppressant action via the VDRG. Clinical studies have pointed out that vitamin D deficiency may exacerbate the development of MS. Because vitamin D3 is an inhibitor of MS, providing supplemental D3 for individuals at risk for MS should be mandatory. There is unanimous agreement that exposure to UVR and vitamin D3 supplementation can reduce the incidence of MS. Although there is debate regarding the association of MS with the use of silver mercury fillings, there is general agreement throughout the world that there is a need for dental-patient informed-consent brochures for all dentists who use dental restoration materials. For the dentists who remove silver mercury amalgam from their patients, there is a uniform international agreement that all dental offices should use reliable debris collection devices that prevent pollution of our environment.

Dangers of cornstarch powder on medical gloves: seeking a solution.

This article reviews information on the hazards of cornstarch powder on medical gloves. Dusting powders were first applied to latex gloves to facilitate donning. After 1980, manufacturers devised innovative techniques without dusting powder. It has been well documented that these powders on gloves present a health hazard to patients and health care workers by 5 different mechanisms. First, the glove cornstarch has documented detrimental effects on wound closure techniques. Second, this powder potentiates wound infection. Third, cornstarch induces peritoneal adhesion formation and granulomatous peritonitis. Finally, these powders serve as carriers as latex allergen and they precipitate a life-threatening allergic reaction in sensitized patients. These well-documented hazards of glove powder have caused the United Kingdom and Germany to ban cornstarch powder on medical gloves over 10 years ago.

Pandemic preparedness for swine flu influenza in the United States.

In March and early April 2009, Mexico experienced outbreaks of influenza caused by the H1N1 virus, which has spread throughout the world. With the pandemic of H1N1 infections, we have discussed in this scientific article strategies that should limit the spread of the influenza A (H1N1) virus in our country. Specific vaccines against the influenza H1N1 virus are being manufactured, and a licensed vaccine is expected to be available in the United States by mid-October 2009. However, some health-care workers may be hesitant to take a vaccine because it contains a mercury preservative-thimerosal-which can be harmful to their health. When caring for patients with respiratory infections, the health-care worker should be wearing a facial respirator. In a report from the Centers for Disease Control and Prevention (CDC), it was indicated that each health-care professional should be required to do a respiratory fit testing to identify the ideal model. Because it has been well documented that a vitamin D deficiency can precipitate the influenza virus, we strongly recommend that all health-care workers and patients be tested and treated for vitamin D deficiency to prevent exacerbation of a respiratory infection.

Reducing workers' compensation costs for latex allergy and litigation against glove manufacturing companies.

It has been well documented in the medical literature that powdered medical gloves can have serious consequences to patients and health-care workers. Adverse reactions to natural latex gloves, such as contact dermatitis and urticaria, occupational asthma, and anaphylaxis, have been documented as a significant cause of Workers' Compensation claims among health-care workers. While the cost of examination and surgical gloves is significant, this factor must be considered with the total cost of Workers' Compensation claims and possible litigation bestowed upon hospitals and glove manufacturing companies. In the United States, Canada, Belgium, and Germany, medical leaders have documented the dangers of powdered latex gloves and have implemented transition programs that are reducing Workers' Compensation claims filed by health-care workers. While attorneys view litigation against powdered glove manufacturers as the "next big tort", the authors of this article were not able to document all compensation costs to disabled workers because many settlements do not allow the claimant to disclose this information.