Presence of five conditioning film proteins are highly associated with early stent encrustation

PURPOSE

Ureteral stents are susceptible to biofilm formation and crystal deposition, especially in stone formers. To identify proteins responsible for this accumulation, we compared conditioning film proteomes obtained from human ureteral stents with and without encrustation.

MATERIALS AND METHODS

Twenty-seven Bard Inlay hydrophilic ureteral stents were removed after ureteroscopy. Stent encrustation was quantified by visual analog score 0 (none) to 4 (heavy) and further categorized as nonencrusted (scores 0 and 1; n = 22) or encrusted (scores 2, 3, and 4; n = 5). Stent conditioning film was sampled and digested with trypsin, and peptide tandem mass spectrometry data were acquired using liquid chromatography. After protein identification, unconditional exact tests were used to compare categorical variables versus encrustation outcome. Stone analysis and follow-up metabolic urine profiles were examined to identify additional risk factors for stent encrustation.

RESULTS

More than 300 unique proteins with >95% confidence were identified. Proteins alpha-1 anti-trypsin, Ig kappa, IgH G1, and histone H2b and H3a were found to be highly associated with stent encrustation (p < 0.05), while Tamm-Horsfall protein and histone H2a were found to have a marginal association (p < 0.1). Patients with early stent encrustation were more likely to have mixed stone analysis (p = 0.03) and low urinary volumes (p < 0.01).

CONCLUSION

Immunoglobulins and Tamm-Horsfall protein are common urinary proteins that appear to nonselectively bind early onto ureteral stent surfaces. Histones, nuclear DNA-condensing proteins, likely contribute to stent encrustation because of their unique net positive charge and may represent a potential clinical target for encrustation prevention.

Dietary oestrogens and male fertility potential

Reports of increased incidences of male reproductive abnormalities and falling sperm counts have prompted interest into the nature of these threats to global fertility. Xenoestrogens have been flagged as major culprits but to date, little is known about the effects of dietary phytoestrogens on male reproductive health. These non-steroidal oestrogens of plant origin are potent endocrine disruptors that modulate normal physiological functions. Phytoestrogens have become a major component in the typical Western fast food diet over the last few decades. Soy formula milk is another common source of phytoestrogens, now used increasingly as an alternative to breast or cow's milk for infants with allergies. This use is of particular concern since the most vulnerable periods for oestrogenic insult are thought to be the pre- and neonatal periods when irreversible damage can be inflicted on the developing germinal epithelium. Studies into the safety of phytoestrogens are urgently needed either to allay fears or increase awareness of the effects of our modern diet on future fertility.

Ultrawide-Angle Retinal Imaging and Retinal Detachment

PURPOSE

To illustrate the utility of ultrawide-angle fundus imaging in documenting the clinical course of a retinal detachment.

DESIGN

Observational case report.

METHOD

A 20-year-old man with high myopia and a blind fellow eye noted symptoms of retinal detachment and was imaged with an ultrawide-angle fundus imaging device (Optos P200). Imaging was performed after scleral buckling and before and after additional vitreoretinal surgery.

RESULTS

Ultrawide-angle images were useful in delineating the extent of retinal detachment even in the presence of intraocular gas.

CONCLUSION

The ability to rapidly image the ocular fundus well anterior to the equator facilitates clinical management and may prove particularly useful in electronic record keeping.

Surveillance results of depleted uranium-exposed Gulf War I veterans: sixteen years of follow-up

As part of a longitudinal surveillance program, 35 members of a larger cohort of 77 Gulf War I veterans who were victims of depleted uranium (DU) "friendly fire" during combat underwent a 3-day clinical assessment at the Baltimore Veterans Administration Medical Center (VAMC). The assessment included a detailed medical history, exposure history, physical examination, and laboratory studies. Spot and 24-h urine collections were obtained for renal function parameters and for urine uranium (U) measures. Blood U measures were also performed. Urine U excretion was significantly associated with DU retained shrapnel burden (8.821 mug U/g creatinine [creat.] vs. 0.005 mug U/g creat., p = .04). Blood as a U sampling matrix revealed satisfactory results for measures of total U with a high correlation with urine U results (r = .84) when urine U concentrations were >/=0.1 mug/g creatinine. However, isotopic results in blood detected DU in only half of the subcohort who had isotopic signatures for DU detectable in urine. After stratifying the cohort based on urine U concentration, the high-U group showed a trend toward higher concentrations of urine beta(2) microglobulin compared to the low-U group (81.7 v. 69.0 mug/g creat.; p = .11 respectively) and retinol binding protein (48.1 vs. 31.0 mug/g creat.; p = .07 respectively). Bone metabolism parameters showed only subtle differences between groups. Sixteen years after first exposure, this cohort continues to excrete elevated concentrations of urine U as a function of DU shrapnel burden. Although subtle trends emerge in renal proximal tubular function and bone formation, the cohort exhibits few clinically significant U-related health effects.

Second prize: Comprehensive proteomic analysis of human calcium oxalate monohydrate kidney stone matrix

BACKGROUND AND PURPOSE

Previous efforts to identify the protein content of stone matrix have been limited by the lack of technology necessary to analyze the highly insoluble protein-crystalline complex. Our study objective is to characterize the matrix of calcium oxalate monohydrate (COM) stones using a comprehensive proteomics approach.

MATERIALS AND METHODS

Seven pure COM stones were powdered, and proteins were extracted using four different buffer solutions. Detergent cleanup spin columns or concentrators were used to remove detergent and to exchange buffers before trypsin digestion. Tryptic peptides were analyzed with reversed-phase, high-performance liquid chromatography (RP-HPLC) and tandem mass spectrometry (MS/MS) using a QSTAR Pulsar i quadrapole time of flight mass spectrometer. Tandem mass spectra were searched against National Center for Biotechnology Information human nonredundant database using ProteinPilot 1.0 software (Applied Biosystems, Inc.) for protein hits; peptide MS/MS spectra were manually inspected.

RESULTS

Of the four buffers, only 2% sodium dodecyl sulfate (SDS) samples had normal HPLC and MS/MS elution patterns. We identified 68 distinct proteins with 95% confidence. More than 50 of the proteins have not been previously identified in stone matrix. Of particular note, a significant number of inflammatory proteins were identified, including immunoglobulins, defensin -3, clusterin, complement C3a, kininogen, and fibrinogen.

CONCLUSIONS

SDS reducing buffer was efficient at solubilizing proteins from stone matrix for further MS-based proteomic analysis. A variety of cellular, structural, and plasma proteins comprise COM stone matrix. Several of the stone proteins are involved in cell injury pathways, which suggests that inflammation plays a role in human COM stone formation.

Contractual obligations and the sharing of confidential health information in sport

As an employee, a sports doctor has obligations to their employer, but also professional and widely accepted obligations of a doctor to the patient (in this case the individual team member). The conflict is evident when sports doctors are asked by an athlete to keep personal health information confidential from the coach and team management, and yet both doctor and athlete have employment contracts specifying that such information shall be shared. Recent research in New Zealand shows that despite the presence of an employment contract, there appears to be a wide range of behaviours among sports doctors when an athlete requests that information about them be kept from team management. Many seem willing to honour requests to keep health information about the athlete confidential, thereby being in breach of the employment contract, while others insist on informing team management against the wishes of the athlete. There are a number of potential solutions to this dilemma from forcing doctors to meet their contractual obligations, to limiting the expectations of the employment contract. This paper suggests that at times it may be appropriate to do both, making the position of the doctor clearer and supporting the ability of this group to resist pressure by coaches and management through having a robust code of ethics.

Does orally administered doxycycline reach the tear film?

BACKGROUND/AIMS

Orally administered doxycycline, a broad-spectrum antibiotic, is an established treatment for ocular surface diseases, particularly rosacea, meibomian gland dysfunction and recurrent epithelial cell erosion. In recent times, its efficacy in treating these diseases has been ascribed to an ability to inhibit matrix metalloproteinase (MMP) activity and both MMP and interleukin-1 (IL-1) synthesis. Since these functions are concentration-dependent, the aim of this project was to determine whether sufficient doxycycline reached the tear film to fulfil these roles in vivo.

METHODS

Doxycycline was extracted with 1-butanol from tear and blood plasma samples obtained from patients with ocular surface disease and healthy individuals and quantified spectrophotometrically. The MMPs present in the patients tear films before and during doxycycline treatment were analysed zymographically.

RESULTS

The quantity of doxycycline detected in the blood plasma samples of patients undergoing treatment ranged from 1.83 to 13.18 microM. Although doxycycline was not detected in their tear samples, the treatment caused the disappearance of the MMPs symptomatic of disease progression.

CONCLUSION

The inability to detect doxycycline in the tear film of patients undergoing treatment indicates that doxycycline does not directly inhibit MMP activity or the synthesis/secretion of these proteases and IL-1 from corneal epithelial cells.

Evaluating the adequacy of disease control in patients with rheumatoid arthritis: a RAND appropriateness panel

OBJECTIVES

There is a lack of agreement on assessing disease activity in patients with RA and determining when the RA treatment should be changed or continued. A panel of rheumatologists was convened to develop guidelines to assess adequacy of disease control, focusing on the use of disease-modifying anti-rheumatic drugs.

METHODS

The Research and Development/University of California in Los Angeles (RAND/UCLA) Appropriateness Method was used to evaluate disease control adequacy. After a literature review, 108 scenarios were developed to simulate situations most likely to be encountered in clinical practice and rated on a 9-point scale by a 10-member expert panel.

RESULTS

Final appropriateness rankings for the scenarios were as follows: 37% 'appropriate', 48% 'inappropriate', and 16% 'neutral'. The panelists felt that patients with disease control in the 'appropriate' range have adequate control with their current therapy, whereas those in the 'inappropriate' range should be considered for a change in therapy. Those in 'neutral' areas should have their therapy reviewed carefully. The panelists recommended that the clinically active joint count should be considered the most important decision factor. In patients with no clinically active joints, regardless of other factors no change in therapy was felt to be warranted. Patients with five or more active joints should be considered inadequately treated, and in patients with one to four active joints other variables must be considered in the decision to change therapy.

CONCLUSION

These preliminary guidelines will assist the clinician in determining when a patient's clinical situation warrants therapy escalation and when continuing the current regimen would be appropriate.