The potential economic value of sputum culture use in patients with community-acquired pneumonia and healthcare-associated pneumonia.

OBJECTIVE: Despite numerous studies, the clinical value of sputum cultures in the management of pneumonia remains controversial; therefore, understanding the economic value of sputum cultures may help decision makers determine their appropriate use in patient management. METHODS: We developed a decision model to determine the economic and clinical value of using sputum cultures in the treatment of community-acquired pneumonia (CAP) and healthcare-associated pneumonia (HCAP) from the hospital perspective under various conditions. RESULTS: For both CAP and HCAP patients, obtaining sputum cultures resulted in similar costs compared to no culture, even if cultures cost $0. Given current clinical practices, obtaining cultures cost $539-631 more per CAP patient and $13-170 per HCAP patient compared to no culture use. However, cultures saved $8-202 per HCAP patient with a 40% probability the pathogen was the true cause (75% reduction in adverse outcomes, greater length of hospital stay (LOS) increase) to a 70% probability the pathogen was the true cause (25% reduction in outcomes and greater LOS increase and a 75% reduction in outcomes and all LOS increases). Additionally, obtaining sputum cultures had no impact on the number of adverse outcomes (i.e., adverse drug events, Clostridium difficile infection, pneumonia readmissions, additional hospitalization days). When all patients were treated with antibiotics empirically, obtaining cultures saved $4-342. CONCLUSIONS: Overall, obtaining sputum cultures does not provide significant clinical or economic benefits for CAP or HCAP patients; however, it can reduce costs and shorten overall LOS under some circumstances. Clinicians should consider their local conditions when making decisions about sputum culture use.

Compliance with the North American Guidelines for Children's Agricultural Tasks (NAGCAT) work practice recommendations for youth working with large animals.

The North American Guidelines for Children's Agricultural Tasks (NAGCAT) were developed to reduce the risk of childhood agricultural injury. The purpose of this study was to evaluate compliance with NAGCAT-recommended work practices (WPs) when youth work with large animals. On a daily basis, over a period of 10 weeks, youth self-reported the number of minutes they worked with a large animal and whether they followed the associated NAGCAT WP guidelines. Statistical analyses were conducted to compare boys to girls and to consider the effect of factors such as youth age, farm residence status, and selected parental characteristics. A high proportion of youth exhibited relatively low compliance for most of the five WPs evaluated. Respirators were rarely worn, but checking for people and obstacles in the area while working with large animals was commonly reported. In general, boys, especially the older boys, exhibited higher compliance than did girls. The results of our study demonstrate, in general, that youth are not following recommended NAGCAT WPs when working with large animals, identifying an area in agricultural safety and health requiring focused attention.

Compliance with NAGCAT work practices recommendations for youth cleaning service alleys in stall barns.

Unintentional injury is the leading cause of death in the U.S. among persons 1 to 44 years of age. Over one million children and adolescents in the U.S. live, work, and/or play on farms, where injury risk is relatively high compared to other settings. In an attempt to reduce the number of childhood agricultural injuries occurring on farms, the North American Guidelines for Children's Agricultural Tasks (NAGCAT) was developed to assist parents or other caregivers in assigning developmentally appropriate chores to youth exposed to agricultural hazards. The results presented here are from a longitudinal study in which we obtained (self-reported) daily chore, injury, and safety behavior data from children and adolescents. We focused on one NAGCAT chore, cleaning a service alley in a stall barn, in order to estimate the extent of compliance with specific work practice recommendations contained in the NAGCAT. Our results indicated that among the four NAGCAT-recommended safety practices for cleaning service alleys in stall barns (wearing nonskid shoes, leather gloves, a respirator, and eye protection), wearing non-skid shoes was the only safety practice reported with any degree of regularity. Overall, boys were more likely to wear non-skid shoes compared to girls. In addition, older youth were generally more likely to report higher work practice compliance compared to younger youth.

Calcified matrix production by SAOS-2 cells inside a polyurethane porous scaffold, using a perfusion bioreactor.

The repair and regeneration of damaged or resected bone are problematic. Bone autografts show optimal skeletal incorporation, but often bring about complications. Hence, there is increasing interest in designing new biomaterials that could potentially be used in the form of scaffolds as bone substitutes. In this study we used a hydrophobic cross-linked polyurethane in a typical tissue-engineering approach, that is, the seeding and in vitro culturing of cells within a porous scaffold. The polyurethane porous scaffold had an average pore diameter of 624 microm. Using a perfusion bioreactor, we investigated the effect of shear stress on SAOS-2 human osteoblast proliferation and calcified matrix production. The physical, morphological, and compressive properties of the polyurethane foam were characterized. At a scaffold perfusion rate of 3 mL/min, in comparison with static conditions without perfusion, we observed 33% higher cell proliferation; higher secretion of osteopontin, osteocalcin, decorin, and type I collagen (9.16-fold, 71.9-fold, 30.6-fold, and 18.12-fold, respectively); and 10-fold increased calcium deposition. The design of the bioreactor and the design of the polyurethane foam aimed at obtaining cell colonization and calcified matrix deposition. This cultured biomaterial could be used, in clinical applications, as an osteoinductive implant for bone repair.

Amyloid fibrils derived from the apolipoprotein A1 Leu174Ser variant contain elements of ordered helical structure.

We recently described a new apolipoprotein A1 variant presenting a Leu174Ser replacement mutation that is associated with a familial form of systemic amyloidosis displaying predominant heart involvement. We have now identified a second unrelated patient with very similar clinical presentation and carrying the identical apolipoprotein A1 mutation. In this new patient the main protein constituent of the amyloid fibrils is the polypeptide derived from the first 93 residues of the protein, the identical fragment to that found in the patient previously described to carry this mutation. The X-ray fiber diffraction pattern obtained from preparations of partially aligned fibrils displays the cross-beta reflections characteristic of all amyloid fibrils. In addition to these cross-beta reflections, other reflections suggest the presence of well-defined coiled-coil helical structure arranged with a defined orientation within the fibrils. In both cases the fibrils contain a trace amount of full-length apolipoprotein A1 with an apparent prevalence of the wild-type species over the variant protein. We have found a ratio of full-length wild-type to mutant protein in plasma HDL of three to one. The polypeptide 1--93 purified from natural fibrils can be solubilized in aqueous solutions containing denaturants, and after removal of denaturants it acquires a monomeric state that, based on CD and NMR studies, has a predominantly random coil structure. The addition of phospholipids to the monomeric form induces the formation of some helical structure, thought most likely to occur at the C-terminal end of the polypeptide.

Sodium arsenate induces overproduction of interleukin-1alpha in murine keratinocytes: role of mitochondria.

It has recently been demonstrated that arsenic induces overexpression of keratinocyte-derived growth factors, which are likely to have a significant role in arsenic-induced skin hyperkeratoses and cancer. The mechanism(s) involved in this induction are, however, still elusive. The purpose of this study was to investigate the early intracellular events that follow in vitro treatment with sodium arsenate in a murine keratinocyte cell line (HEL30), which leads to cytokine overproduction. First, we observed that sodium arsenate induced a concentration-dependent production of interleukin-1alpha and a significant increase in cell proliferation, that could be suppressed by the addition of a neutralizing antibody against murine interleukin-1alpha, confirming the ability of arsenic to induce keratinocyte growth-promoting cytokines. Electron microscopic analysis revealed that arsenate induced a dramatic alteration in keratinocyte mitochondria. This effect could be prevented by rotenone pretreatment, which suggests the possible involvement of mitochondria-derived reactive oxygen species. Arsenic induced a concentration- and time-dependent increase in cellular oxidative activity, which was followed by activation of redox-sensitive transcription factors such as nuclear factor-kappaB and activator protein-1, that are essential for interleukin-1alpha synthesis. Prior treatment with rotenone or prolonged treatment with ethidium bromide, an inhibitor of mitochondrial DNA and RNA synthesis, to deplete cells of functional mitochondria, completely prevented sodium arsenate-induced interleukin-1alpha production, this indicates the pivotal role of these organelles in sodium arsenate-induced keratinocyte growth factors.

Beta2-microglobulin can be refolded into a native state from ex vivo amyloid fibrils.

Beta2-microglobulin fibrils have been extracted from the femoral head of a patient who has been under chronic haemodialysis for 11 years. The primary structure of the N-terminal portion of the protein and mass determination by electrospray mass spectrometry demonstrate that beta2-microglobulin, extracted as fibrils by the water extraction procedure, was not glycated and that Asn17 was not deamidated. Limited proteolysis was observed in more than 20% of beta2-microglobulin molecules and the main cleavage sites were at the C-terminus of Lys6 and Tyr10. Beta2-microglobulin from fibrils has been purified by gel filtration in 6 M Gdn/HCl and submitted to a refolding procedure. The refolding conditions have been determined through the study of the unfolding pathway of the native protein. Beta2-microglobulin is stable at neutral pH where it displays a lower tendency to self-aggregate than in acidic conditions. Pulse dilution and extensive dialysis in refolding buffer at pH 7.5 yields beta2-microglobulin with a tertiary structure identical to that of the native form. The CD spectrum in the near-ultraviolet region and the spectrum of the intrinsic fluorescence of Trp overlap those of the native protein, but the CD spectrum in the far-ultraviolet region is affected by the contribution of oligomers created by beta2-microglobulin fragments that reduce the positive light polarisation at 205 nm typical of native beta2-microglobulin.

Treatment of chronic hepatitis B (HBeAg-HBV DNA-positive) with lymphoblastoid alpha interferon with or without corticosteroids: short- and long-term follow-up.

Efficacy and safety of therapy with lymphoblastoid interferon-alpha alone or combined with deflazacort has been investigated in 38 HBsAg-HBeAg+ patients with biopsy-proven chronic hepatitis. Group I received 5 MU/m2 interferon thrice a week for 26 weeks; group II took interferon for 26 weeks simultaneously with a 6-week course of deflazacort. Follow-up was 18-72 months (median 42). After 12 months, responses were achieved in 3 (18%) out of 17 patients on interferon alone vs 5 (26%, p > 0.05) out of 19 on combined therapy. Blind histological assessment revealed no improvement in either group or in patients who responded to therapy within the first year of follow-up ("early responders"). "Delayed" responses were observed in 4 (29%) patients who took interferon alone vs 5 (36%, p > 0.05) who took the combined therapy. Serum HBV DNA levels decreased significantly during treatment and remained low up to 24 and 36 months of follow-up in both groups. One early responder developed hepatocellular carcinoma, another had exacerbation of liver disease in long-term follow-up. No non-responders developed liver failure or hepatocellular carcinoma. These results indicate that lymphoblastoid interferon-alpha inhibits HBV replication and corticosteroids have no synergistic effect in treatment of HBsAg-HBeAg+ chronic hepatitis.

Iron status in children undergoing tonsillectomy and its short-term modification following surgery.

Red cell and iron status parameters were studied in a group of 44 children undergoing tonsillectomy for recurrent throat infections and in a control group of 40 healthy children. In the patient group, before tonsillectomy, 8 children presented a latent iron deficiency and 15 a decrease in serum ferritin levels. This altered iron status can be attributed to a reduced intestinal iron absorption, due to recurrent infections. One and seven days following surgery there was a significant fall in serum iron, serum transferrin and transferrin saturation, in parallel with an increase of serum ferritin and alpha-2 globulins levels. These modifications cannot be attributed to the blood loss, as proven by the constancy of haemoglobin level and of other red cell parameters, but to an unspecific reaction to surgical stress, as observed in fever, traumas and inflammation. They reflect an altered processing of iron, with a temporary block of its release to plasma and an increased storage within the reticuloendothelial cells.