Characteristics of oxygen concentration and the role of correction factor in real-time GI breath test.

OBJECTIVE: A high quality end-expiratory breath sample is required for a reliable gastrointestinal breath test result. Oxygen (O2) concentration in the breath sample can be used as a quality marker. This study investigated the characteristics of O2 concentration in the breath sample and the impact of using a correction factor in real-time breath measurement. DESIGN: This study includes two separate groups of patient data. Part 1 of the study analysed the patient's ability to deliver end-expiratory breath samples over a 2-year period (n=564). Part 2 of the study analysed a separate group of patients (n=47) with additional data to investigate the O2 characteristics and the role of correction factor in breath test. RESULTS: The results indicated 95.4% of 564 patients were able to achieve an O2 concentration below 14% in their end-expiratory breath. Part 2 of the study revealed that the distribution of O2 concentration was between 9.5% and 16.2%. Applying a correction factor to predict the end-expiratory H2 and CH4 values led to an average measurement error of -36.4% and -12.8%, respectively. CONCLUSION: The majority of patients are able to deliver a high quality end-expiratory breath sample, regardless of age or gender. The correction factor algorithm is unreliable when predicting the end-expiratory result at 15% O2 and it would have resulted in false negative result for 50% of the positive cases in this study. It has also indicated that the continuous O2 measurement is essential to ensure breath sample quality by preventing secondary breathing during real-time breath collection.

Doppler ultrasound flowmetry predicts 15 year outcome in patients with skin melanoma.

UNLABELLED: This prospective cohort study was conducted to find the role of tumor neovascularization in skin melanoma measured by preoperative Doppler ultrasound flowmetry in determining the 15-year outcome. SETTING: Department of Surgery, University of Wales College of Medicine, Cardiff, UK. Seventy-one primary melanomas in 67 patients were studied with a 10 MHz Doppler ultrasound flowmeter. The flow signals were recorded on an audiotape. The peak systolic frequency, mean systolic frequency, and minimum diastolic frequency were measured on a spectrum analyzer. The follow-up (median 144 months) information is complete till December 2005 on 63 patients. Blood flow signals were detected in 41 lesions; these were labeled Doppler flow positive. No flow was detected in 22 lesions, labeled Doppler flow negative. Among the Doppler flow positive group, 39% patients have died with metastatic melanoma, whereas none of the patients with a Doppler-negative lesion have died or developed any recurrence. Higher peak systolic frequency (above 2,500 MHz.) was associated with a hazard ratio for death due to melanoma of (HAZARD RATE = 5.99). Higher risk of death, locoregional, and systemic recurrences were associated with higher peak systolic frequency. Doppler flowmetry performed preoperatively is a noninvasive, quick, and simple method to assess tumor blood flow which may help in predicting long-term survival and planning neoadjuvant therapies aimed at inhibiting angiogenesis or targeting tumor vasculature.

Imiquimod 5% cream monotherapy for cutaneous squamous cell carcinoma in situ (Bowen's disease): a randomized, double-blind, placebo-controlled trial.

BACKGROUND: We conducted a double-blind, placebo-controlled, randomized trial to evaluate the preliminary efficacy and safety of imiquimod 5% cream treatment for cutaneous squamous cell carcinoma (SCC) in situ. METHODS: In all, 31 patients with biopsy-proven cutaneous SCC in situ were randomly assigned to placebo (vehicle) (n = 16) or imiquimod 5% cream (n = 15) daily for 16 weeks. Patients were assessed at week 28 for the primary end point, resolution of cutaneous SCC in situ. RESULTS: Of the 31 patients enrolled, 3 dropped out. Intention-to-treat analysis revealed 11 of the 15 patients (73%) in the imiquimod group achieved resolution of cutaneous SCC in situ, with no relapse during the 9-month follow-up period; none in the placebo group achieved resolution (P < .001). Imiquimod 5% cream was generally well tolerated and there were no serious adverse events. LIMITATIONS: Topical imiquimod 5% cream has proven to be an effective treatment for cutaneous SCC in situ. However, studies to define the ideal dosing regimen and cost-effectiveness are required before it can be accepted as a recognized therapy. CONCLUSIONS: In this controlled trial, patients with cutaneous SCC in situ receiving topical imiquimod 5% cream as monotherapy experienced a high degree of clinical benefit compared with placebo.

Photosensitivity and acute liver injury in myeloproliferative disorder secondary to late-onset protoporphyria caused by deletion of a ferrochelatase gene in hematopoietic cells.

Late-onset erythropoietic protoporphyria (EPP) is a rare complication of myelodysplastic syndrome (MDS) but has not been described in association with a myeloproliferative disorder (MPD). EPP is normally an inherited disorder characterized by photosensitivity that starts in early childhood and results from overproduction of protoporphyrin secondary to ferrochelatase (FECH) deficiency. Severe liver disease occurs in 1% to 2% of patients. Here we report that severe photosensitivity and cholestatic liver disease in a patient with a myeloproliferative disorder was caused by excess protoporphyrin production from a clone of hematopoietic cells in which one FECH allele had been deleted. Our observations suggest that the usual explanation for the association of late-onset EPP with MPD and MDS is acquired somatic mutation of one FECH allele in bone marrow and show for the first time that the consequent overproduction of protoporphyrin may be severe enough to cause acute liver damage.