Biology and Biomechanics in Osteosynthesis of Proximal Humerus Fractures

Abstract Surgical treatment of proximal humeral fractures still remains a challenge. This is primarily due to the fact that sufficient implant fixation in humeral head fractures is often not achieved due to substantial bone tissue loss with increasing age. In the last few years the locking plates and locking nails have been introduced into clinical practice with varying results. The biomechanical studies have focused on locking plate osteosynthesis as well. The following paper focuses on bone quality, biomechanical studies and biology of proper osteosynthesis and reviews the most recent literature.     

The use of a new hydrophilic polymer, Kollicoat IR, in the formulation of solid dispersions of Itraconazole.

Kollicoat IR, a new pharmaceutical excipient developed as a coating polymer for instant release tablets, was evaluated as a carrier in solid dispersions of Itraconazole. The solid dispersions were prepared by hot stage extrusion. Modulated temperature differential scanning calorimetry and X-ray powder diffraction were used to evaluate the miscibility of the drug and the carrier. The pharmaceutical performance was evaluated by dissolution experiments, performed in simulated gastric fluid without pepsin (SGF(sp)). In the X-ray diffractograms no Itraconazole peaks were visible; the polymer on the other hand appeared to be semi-crystalline. Moreover, its crystallinity increased during the extrusion process due to exposure to heat and shear forces. Modulated temperature differential scanning calorimetry analysis showed that the drug and the polymer formed a two phase system. Separate clusters of glassy Itraconazole were present for drug loads of 40% or higher, indicating further phase separation. Dissolution measurements demonstrated a significantly increased dissolution rate for the solid dispersions compared to physical mixtures. Interestingly the physical mixture made up of glassy Itraconazole and Kollicoat IR (20/80, w/w) showed a dissolution rate and maximum that was much higher than that of the physical mixture made up of crystalline Itraconazole and that of pure glassy Itraconazole. The results of this study show that Kollicoat IR is a promising excipient for the formulation of solid dispersions of Itraconazole prepared by hot stage extrusion.     

Assessment of alcohol and other drug use behaviors in health professions students.

Alcohol and other drug (AOD) use behaviors of health professions students (HPS) were assessed by surveying both university-based HPS and other nursing programs in a Midwestern state in 1999. Response was 2,646 (56.4%) of surveyed students. Family history of alcohol-related and drug-related problems were reported by 39.8% and 13.9%, respectively, with 42.6% of respondents reporting one or both. Among nursing respondents, 48.1%, 19.2% and 51.1%, respectively, reported family problems with alcohol, drugs, or one or both. Past-year alcohol use was comparable to undergraduate college students (UCS) nationally (83%); heavy drinking, tobacco and recreational drug use by HPS were lower. Past year drug use was highest among medical students. Marijuana was the predominant illicit drug; medical students and males most often reported use. Health professions educational systems should proactively address student AOD prevention, education and assistance needs.     

Standardized quick en bloc technique for procurement of cadaveric liver grafts for pediatric liver transplantation

This paper describes a quick procedure for cadaveric liver graft retrieval during multiple organ harvesting. The technique is based on minimal preliminary dissection, absence of in situ direct portal perfusion, and en bloc removal of the liver and pancreas, with an aortic patch encompassing the coeliac trunk and superior mesenteric artery. The results of 110 pediatric liver transplantations with 109 organs harvested using this technique are reported. There were no graft harvesting injuries. The liver graft primary nonfunction rate was 4.5% (5/110). The 3-month retransplantation rate was 10%. The actual patient survival rates were 93% at 3 months and 90% at 1 year; actual graft survival rates were 85.5% and 78%, respectively. The technique described was at least as safe as conventional procedures. A major advantage of the procedure is its flexibility, which allows for the easily combined procurement of other organs (whole pancreas and intestine).     

The Problem of Intractability: The Continuing Need for New Medical Therapies in Epilepsy

Summary: Treatment of epilepsy, one of the most common neurologic disorders, has evolved from "institutional" poly-therapy to "dogmatic" monotherapy, and, most recently, to "rational" polypharmacy. The introduction of bromides for the treatment of epilepsy was followed first by phenobarbital and then by phenytoin as therapeutic options. Although attempts to combine medications were legion, none was supported by studies that demonstrated the benefit of such combinations. The issue of adverse effects became a principal argument in favor of monotherapy. Monotherapy, using newly developed drugs, avoided problems due to drug interactions but was ineffective in 20–30% of patients. A greater understanding of basic disease mechanisms and developments in molecular biology have led to an increased number of effective drugs for the estimated 6–12% of patients with epilepsy whose condition is intractable. Clinical research continues to build on the work of basic scientists in attempting to develop treatments based on a desire to move beyond the palliative and to affect the causative mechanisms of the disease. Novel medical approaches now under exploration include the use of drugs with complementary mechanisms of action, stimulation of various components of the nervous system, biochemical manipulations, focal intracerebral drug perfusion, and gene therapy.     

Neurotropic melanoma with prominent melanization

Neurotropic melanoma has generally been described in the context of desmoplastic melanoma. The vast majority of melanomas displaying neurotropism contain relatively little or no melanin. Herein, we report an unusual case of neurotropic melanoma with prominent melanin content. The patient developed a tumor notable For pagetoid (superficial spreading) melanoma with partial regression and a deep component characterized by perineurial aggregates of melanophages and intraneural infiltration by melanoma cells. This case serves to alert dermatopathologists to the fact that the spectrum of neurotropic melanoma includes tumors with perineurial aggregates of pigment-containing cells.     

Transarterial embolization of vein of Galen aneurysmal malformation after unsuccessful stereotactic radiosurgery

The authors present three cases of vein of Galen aneurysmal malformations (VGAMs) diagnosed in infancy and submitted by the referring teams for stereotactic radiosurgery as the initial therapy (therapeutic doses ranging between 20–25 Gy and 40–50 Gy to the peak dose). After the conventional follow-up of 18–24 months, no change could be detected in the angioarchitecture of the lesions. All three cases were then referred for endovascular treatment and underwent embolization by the transarterial route using liquid adhesives (N-butyl cyanoacrylate). This resulted in complete anatomical exclusion of the lesion. Regardless of the theoretical efficiency of radiosurgery in the management of brain arteriovenous malformations, the present authors believe that transarterial embolization remains the treatment of choice in VGAMs. It offers a high rate of morphological cure and the best chances for normal neurocognitive development. The time required by radiosurgery to achieve a significant result is too long for developing and maturing brain and may not prevent the negative effects of the lesion, mainly in regard to hemo- and hydrodynamic disorders (atrophy, subcortical calcifications, etc.) created by the VGAM, thus leading to irreversible mental retardation.     

A column study of the biological mobilization and speciation of cadmium in soil

An acid sandy loam soil was used in a column study to determine the effect of microorganisms on Cd mobilization in soil and its speciation in column leachates. Non-sterile and sterile (gamma-irradiated) soil columns were initially treated with 90 mg of Cd (NO₃)₂, and approximately 20 mg of added Cd was retained in the soil. Soil columns were subsequently eluted with a sterile nutrient medium for a period of up to 38 days. Non-sterile and sterile soil columns leached with sterile deionized water served as unsupplemented controls. During a leaching period of 38 days, about 36% of the sorbed Cd in soil was mobilized in the presence of microorganisms and nutrients, while less than 16% of the Cd was released from the sterile and unsupplemented soil controls. To characterize the chemical form of the microbially mobilized Cd, the leachates were analyzed by gel filtration chromatography. In this study, 86% to 93% of the mobilized Cd was associated with the low molecular weight inorganic and organic fraction, while the remainder was eluted in the high molecular weight range. The low molecular weight Cd fractions were further examined by solid phase extraction (C₁₈ Sep-Pak), and cation-exchange chromatography. From the various analyses, it was concluded that a significant amount of Cd existed as a hydrophilic organic complex, and the remainder as cationic Cd. Soil microorganisms were mostly responsible for the transformation of Cd in soil and its subsequent mobilization.     

BUILDING COMMUNITY: Developing Skills for Interprofessional Health Professions Education and Relationship-Centered Care

In 1995, the National League for Nursing commissioned a Panel on Interdisciplinary/Transdisciplinary Education. The focus of the Panel's work was to examine educational issues that transcend the health professions and to make recommendations for future implementation of an interdisciplinary approach to addressing them. This article is being simultaneously published by several professional journals. The goal is to seek as much feedback as possible.