A randomized controlled trial of the efficacy of autologous platelet therapy for the treatment of osteoarthritis in dogs.

OBJECTIVE: To determine efficacy of a single intra-articular injection of an autologous platelet concentrate for treatment of osteoarthritis in dogs. DESIGN: Randomized, controlled, 2-center clinical trial. ANIMALS: 20 client-owned dogs with osteoarthritis involving a single joint. PROCEDURES: Dogs were randomly assigned to a treatment or control group. In all dogs, severity of lameness and pain was scored by owners with the Hudson visual analog scale and the University of Pennsylvania Canine Brief Pain Inventory, respectively, and peak vertical force (PVF) was determined with a force platform. Dogs in the treatment group were then sedated, and a blood sample (55 mL) was obtained. Platelets were recovered by means of a point-of-use filter and injected intra-articularly within 30 minutes. Control dogs were sedated and given an intra-articular injection of saline (0.9% NaCl) solution. Assessments were repeated 12 weeks after injection of platelets or saline solution. RESULTS: Dogs weighed between 18.3 and 63.9 kg (40.3 and 140.6 lb) and ranged from 1.5 to 8 years old. For control dogs, lameness scores, pain scores, and PVF at week 12 were not significantly different from pretreatment values. In contrast, for dogs that received platelet injections, lameness scores (55% decrease in median score), pain scores (53% decrease in median score), and PVF (12% increase in mean PVF) were significantly improved after 12 weeks, compared with pretreatment values. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that a single intra-articular injection of autologous platelets resulted in significant improvements at 12 weeks in dogs with osteoarthritis involving a single joint.

Filters reduce the risk of bacterial transmission from contaminated heated humidifiers used with CPAP for obstructive sleep apnea.

RATIONALE: The treatment of choice for obstructive sleep apnea (OSA) is nasal continuous positive airway pressure (nCPAP) during sleep, but dryness of the upper airway compromises compliance. Heated humidifiers may mitigate such noncompliance; however, recent observations suggest that their use, particularly if not cleaned, increases the risk of respiratory infections. Humidifier water may be contaminated, but the long-held view that passive humidifiers cannot aerosolize water may obscure the perception of risk of infection. OBJECTIVES: This study challenges the long-held view that "passover" humidifiers do not aerosolize water. With such evidence, this study characterizes the performance of filters to reduce the potential risk of contamination. METHODS: Heated humidifier water contaminated with bacteria was studied under conditions simulating week-long use of nCPAP for OSA. RESULTS: Bacteria were recovered in 9 of 11 tests from the breathing tubes of CPAP devices fitted with heated humidifiers with water contaminated with Brevundimonas diminuta or Serratia marcescens. Recoverable bacteria ranged from tens to thousands of colony forming units when tested at air flow rates of 60 liters per minute for 90 minutes. Neither organism was recovered from the circuit tubing when a hydrophobic breathing-circuit filter was positioned between the humidifier and face-mask tubing with a commercially available nCPAP machine tested under simulated-use conditions. CONCLUSION: Data suggest that patients with OSA being treated with nCPAP fitted with humidifiers may be aerosolizing bacteria, putting them at risk for developing respiratory infections and that the use of a hydrophobic filter may attenuate the passage of microbes from contaminated humidifier water.

An overview of prion biology and the role of blood filtration in reducing the risk of transfusion-transmitted variant Creutzfeldt-Jakob disease.

Prions are infectious proteins believed to be responsible for a variety of progressive and fatal neurodegenerative diseases, collectively referred to as transmissible spongiform encephalopathies (TSE). By 1996, it was recognized that ingestion of beef from cattle afflicted with a TSE known as bovine spongiform encephalopathy, could result in a devastating human TSE known as variant Creutzfeldt-Jakob disease (vCJD). Two recent reports of probable transfusion-transmitted vCJD have raised concerns about the safety of the blood supply. The relatively long asymptomatic latency of vCJD, as well as the lack of sensitive and specific antemortem tests, increase the risk that asymptomatic, infected individuals may become blood donors. To this point, donor deferral has been a strategy used to reduce this risk. Nevertheless, this strategy may be unreliable and, furthermore, may threaten blood availability. Leukoreduction has also been helpful in reducing cell-associated infectious prion, which has been reported to reduce up to 42% of the infectivity in blood. Proprietary prion affinity surface modifications have been developed and applied to filters, which exploit an understanding of the unique chemical characteristics of prion surfaces. These have been successfully adapted to existing high-efficiency blood filter matrices for the reduction of prions present in blood components for transfusion.

Prion biology in transfusion medicine: implications for lab testing.

Although eerily silent for many years after the recognition of scrapie in 1759, TSEs remained present within the genome of some mammals. Not since the mid-1950s when Dr. Carleton Gadjusek visited the Fore Indians of New Guinea to study kuru, however, has there been a more frenetic interest by governmental investigators. Certainly, the U.K. experience has heralded a renewed interest in TSEs due to the notoriety associated with younger subjects succumbing to a variant CJD traced to the ingestion of beef. Human TSEs and the potential for their transmission among and across species of mammals has also captured the attention of many. Yet, to date, there is no reliable antemortem test available to screen for infected animals or humans. Antibody-based assays are difficult to develop because most of them do not have specificity for the pathogenic form of prion protein. Whether or not prion testing efforts will change dramatically depends upon the incidence of disease. Some speculate a reduction in testing, because BSE incidence is waning since the adoption of remedial steps in the U.K. in 1989. Others remind us, however, of the long latency of prion diseases and of the recent observations of two patients who succumbed to vCJD after having received blood products from donors who subsequently died of vCJD. The growing incidence of CWD, combined with the emerging observation that as many as 26% of Alzheimer's patients may have been misdiagnosed--having died instead of prion disease--maintains pressure for legislators to adhere to the precautionary principle and support blood-donor exclusionary criteria, antemortem-test development, and pathogen removal from donated blood. The laboratorian can expect to see new tests for prion disease work their way into clinical-testing practice in the near future. In addition, the adoption of newer filtration technologies holds the promise of improved protection from transfusion-transmitted prion disease.

Hospital water point-of-use filtration: a complementary strategy to reduce the risk of nosocomial infection.

Cholera, hepatitis and typhoid are well-recognized water-borne illnesses that take the lives of many every year in areas of uncontrollable flood, but far less attention is afforded to the allegedly safe potable water in affluent nations and the presumed healthful quality of water in communities and hospitals. Recent literature, however, points to increasing awareness of serious clinical sequelae particularly experienced by immunocompromised patients at high risk for disease and death from exposure to water-borne microbes in hospitals. This review reflects the literature indicting hospital water as an important source for nosocomial infections, examines patient populations at greatest risk, uncovers examples of failures in remedial water treatment methods and the reasons for them, and introduces point-of-use water filtration as a practical alternative or complementary component of an infection control strategy that may reduce the risk of nosocomial infections.

Contamination control in nursing with filtration: part 2: emerging rationale for bedside (final) filtration of prestorage leukocyte-reduced blood products.

The first part of this 2-part series focused on the manufacture of filters and the application of filtration technology to intravenous fluids and point-of-care hospital water. This second part describes an apparent emerging potential for final filtration defined as bedside filtration of blood and component blood products leukocyte-reduced at the blood center prior to storage. Final filtration serves to further reduce the leukocyte burden in a previously leukocyte-reduced blood product. Another target for final filtration includes putative soluble mediators of morbidity.Selected patients may be at greater risk for alloimmunization and refractory to the benefits afforded by transfusion of blood leukocyte reduced to the current established standards. Multiparous patients who subsequently find themselves in need of a transplanted organ are alloimmunized by exposure to fetal proteins and may be further alloimmunized by transfusion. Such effects can put them at risk for increased latency for donor organ availability and organ rejection. Kidney transplant patients find themselves the recipients of transfused blood products particularly during end-stage renal disease and recent data suggest such patients are not benefited by the levels of leukoreduction prescribed by current standards and may need more dramatic leukocyte removal. The process of blood production is described and affords a greater appreciation for the levels of white cells found in component blood products. The development of alloimmunization is reviewed and fosters greater appreciation for a discussion of the potential for therapeutic value of more dramatic leukocyte reduction and blood conditioning accomplished through the removal of soluble mediators of morbidity.

Contamination control in nursing with filtration. Part 1: filters applied to intravenous fluids and point-of-use hospital water.

Filters often are viewed as screens with openings smaller than the particles intended to be removed by a process technically known as direct interception. However, filter manufacturing embraces far more advanced technological approaches, with an evolution toward selective removal of cells or soluble constituents from complex physiologic solutions. An appreciation of filtration development makes it easy to understand how differently manufactured filters with the same claims may not perform identically. This article focuses on the filtration of intravenous solutions and point-of-use hospital water.