Whites and African-Americans in headache specialty clinics respond equally well to treatment

This study sought to determine if Whites and African-Americans respond similarly to headache treatment administered in 'real-world' headache specialty treatment clinics. Using a naturalistic, longitudinal design, 284 patients receiving treatment for headache disorders completed 30-day daily diaries that assessed headache frequency and severity at pretreatment and 6-month follow-up and also provided data on their headache disability and quality of life at pretreatment and 1-, 2- and 6-month follow-up. Controlling for socioeconomic status and psychiatric comorbidity, hierarchical linear models found that African-Americans and Whites reported significant reductions in headache frequency and disability and improvements in life quality over the 6-month treatment period. African-Americans, unlike Whites, also reported significant decreases in headache severity. Nevertheless, Africans-Americans had significantly more frequent and disabling headaches and lower quality of life after treatment relative to Whites. Although Whites and African Americans responded favourably to headache treatments, more efficacious treatments are needed given the elevated level of headache frequency that remained in both racial groups following treatment.     

A prototype HeartQuest ventricular assist device for particle image velocimetry measurements

The objective of this study is to fully characterize the flow within the HeartQuest ventricular assist device (VAD), a magnetically levitated centrifugal VAD, using particle image velocimetry (PIV) to identify regions of potential high shear or stagnation and validate and refine computational models of the flow. An acrylic model of the pump was designed and constructed to allow optical access into all interior regions of the pump. The geometry of the exterior housing and the use of a novel working fluid make quantitative measurements of velocity within the exit volute, blade passage, cut-water, blade tip clearance, and pump inlet possible. Highly accurate velocity measurements using particle PIV have been made in one region (the inlet elbow), and measurements in the other critical regions of the pump will be made. These measurements are used for investigation of regions with potential for hemolysis resulting from high shear stress or with potential for thrombosis caused by recirculation or stagnation. Quantitative velocity data are also needed for comparison with computational fluid dynamics (CFD) models of the VAD. In this study, experiments have again proven to be an essential complement to CFD for thorough investigations of the flow inside the pump.     

Estimates of the chromium(VI) reducing capacity in human body compartments as a mechanism for attenuating its potential toxicity and carcinogenicity

Estimates of the overall reducing capacity of hexavalent chromium(VI) in some human body compartments were made by relating the specific reducing activity of body fluids, cell populations or organs to their average volume, number, or weight. Although these data do not have absolute precision or universal applicability, they provide a rationale for predicting and interpreting the health effects of chromium(VI). The available evidence strongly indicates that chromium(VI) reduction in body fluids and long-lived non-target cells is expected to greatly attenuate its potential toxicity and genotoxicity, to imprint a threshold character to the carcinogenesis process, and to restrict the possible targets of its activity. For example, the chromium(VI) sequestering capacity of whole blood (187-234 mg per individual) and the reducing capacity of red blood cells (at least 93-128 mg) explain why this metal is not a systemic toxicant, except at very high doses, and also explain its lack of carcinogenicity at a distance from the portal of entry into the organism. Reduction by fluids in the digestive tract, e.g. by saliva (0.7-2.1 mg/day) and gastric juice (at least 84- 88 mg/day), and sequestration by intestinal bacteria (11-24 mg eliminated daily with feces) account for the poor intestinal absorption of chromium(VI). The chromium(VI) escaping reduction in the digestive tract will be detoxified in the blood of the portal vein system and then in the liver, having an overall reducing capacity of 3300 mg. These processes give reasons for the poor oral toxicity of chromium(VI) and its lack of carcinogenicity when introduced by the oral route or swallowed following reflux from the respiratory tract. In terminal airways chromium(VI) is reduced in the epithelial lining fluid (0.9-1.8 mg) and in pulmonary alveolar macrophages (136 mg). The peripheral lung parenchyma has an overall reducing capacity of 260 mg chromium(VI), with a slightly higher specific activity as compared to the bronchial tree. Therefore, even in the respiratory tract, which is the only consistent target of chromium(VI) carcinogenicity in humans (lung and sinonasal cavities), there are barriers hampering its carcinogenicity. These hurdles could be only overwhelmed under conditions of massive exposure by inhalation, as it occurred in certain work environments prior to the implementation of suitable industrial hygiene measures.      

Effect of proton pump inhibitors on the detection of Helicobacter pylori in gastric biopsies.

BACKGROUND: Proton pump inhibitors are known to decrease the activity of Helicobacter pylori organisms within the stomach and to shift their distribution proximally. This effect may reduce the sensitivity of histological examination and rapid urease testing for H. pylori on biopsies taken from recommended sites. It is of particular relevance if a proton pump inhibitor has been prescribed before the patient has undergone diagnostic endoscopy. METHODS: We studied patients referred to our open-access upper gastrointestinal endoscopy service who had either been on no medication (controls) or were already taking proton pump inhibitors. Biopsies taken from the gastric antrum and corpus were used for rapid urease testing and for histological examination. Sera, taken from patients who had no evidence of H. pylori in biopsies, were tested for IgG H. pylori antibodies as an alternative indicator of infection. RESULTS: H. pylori organisms were detected by histological examination in 27 of 40 controls (68%) and in 13 of 25 patients taking proton pump inhibitors (52%). Among patients with positive histology (organisms detected in either antral or corpus biopsies, or both), only the sensitivity of the antral urease test read at 1 h was significantly lower in patients taking proton pump inhibitors than in controls, with no significant difference in sensitivities of the antral urease test at 24 h, of the corpus urease test at 1 or 24 h, or of histology from the antrum or corpus. Of patients with negative histology, none of 13 controls compared with six of 12 patients taking proton pump inhibitors (50%) had positive serology (P = 0.005). Five (83%) of the six histology-negative, seropositive patients taking proton pump inhibitors had histological changes consistent with H. pylori gastritis even though no organisms were detected. CONCLUSIONS: Treatment with a proton pump inhibitor before endoscopy reduces the sensitivity of antral and corpus biopsies for H. pylori detection, both by urease testing and histological examination. If proton pump inhibitors already prescribed cannot be discontinued for an adequate period before endoscopy, patients should have biopsies taken from the corpus as well as from the antrum, and serum should be tested for H. pylori.     

Pulmonary hemorrhage in children with glomerulonephritis

Pulmonary hemorrhage may occur in patients with immune-mediated glomerulonephritis. This association can be seen in a variety of disorders including systemic lupus erythematosus, vasculitis, Wegener's granulomatosis, anaphylactoid purpura and Goodpasture's syndrome. Immune mechanisms, such as immune complexes and/or autoantibodies, play a role in the pathogenesis of pulmonary and glomerular injury. Acute pulmonary hemorrhage can lead to respiratory failure and has a high mortality. Therapy with immunosuppressive agents such as pulse methylprednisolone and cyclophosphamide will control the hemorrhage and improve pulmonary function in most cases.     

Short stature, pulmonary hypertension, sclerodactyly-like involvement and dysmorphic appearance: a newly described syndrome?

We report a 21-year-old woman who has moderate to severe pulmonary hypertension, short stature, dysmorphic appearance, lipodystrophy and sclerodactyly-like involvement of her extremities. Cognitive development is in the low-average range. Various diagnoses have been suggested over the years, but none seem to fit her clinical presentation exactly. We suggest that she may have a previously undescribed connective tissue disorder with primary pulmonary involvement.