Role of the hemobiologist in the detection and prevention of post-transfusional hepatitis

To prevent post-transfusional hepatitis B and C, two epidemiologic studies were performed. The first, based on the frequencies distribution of hepatitis B virus serological markers versus sex and classes of age, has permitted the assessment of the profile of the infection in a population composed of 573 north vietnamese blood donors. There is no significant difference between men and women frequencies of HBs antigen (11.5%), anti-HBs antibody (70.2%) and anti-HBc antibody alone (3.8%), but a significant difference of no-marker frequencies: 7.8% and 17.9% in men and women respectively (X2 = 9.11; p = 0.010). The percentage of no-marker decreases when the mean age of each class increases. The second, using the increase of the serum alanine aminotransferase (ALAT) activity as an indirect marker of non-A, non-B hepatitis for determining in a population of more than 25,000 parisian blood donors, the percentage of donors eliminated. They are between 0.70 and 0.76 in women and 2.26 and 2.46 in men. These investigations can be applied to prevent the hepatitis B transmission in a population of 102 south vietnamese women in age to procreate or to determine the percentage of blood donors eliminated (3.12%) in a population of 2,950 Parisians composed in majority (50.9%) of new donors. The hemobiologist will have an important role to elaborate strategies for orientation of blood gifts with hepatitis B and C virus markers.     

The usefulness of the timeliness of endoscopic sphincterotomy in severe acute pancreatitis of biliary origin

There are evidence indicating that endoscopic retrograde cholangiopancreatography with sphincterotomy (ERCP+S) reduces the rate of complications in patients with severe acute biliary pancreatitis (ABP). The aim of this study was to analyze our experience in the treatment of severe ABP with ERCP+S and compare the evolution of the patients treated early (3 days or less following admission) with those treated late (after the 3rd day). A retrospective review of the clinical histories of the 16 patients with severe ABP treated with ERCP+S over the last two years is presented, analyzing their clinical features on admission and evolution. Biliary stones or biliary sludge was observed in 11 cases (69%). Nine patients had undergone early, and 7 late, ERCP+S. The patients of the latter group presented a greater number of complications during evolution than the former group (43% vs 0%; p = 0.025). The mortality of the patients of the late ERCP+S was also greater although without statistical significance (28.6% vs 0%; p = 0.15). No complication secondary to ERCP+S was detected. These findings confirm the fact that ERCP+S performed early in severe ABP significantly reduces the number of complications and is associated with a lower mortality.     

Alpha-tocopherol as a modulator of smooth muscle cell proliferation

The effects of alpha-tocopherol and beta-tocopherol have been studied in rat and human aortic smooth muscle cells. Alpha-tocopherol, but not beta-tocopherol, inhibited smooth muscle cell proliferation and protein kinase C in a dose-dependent manner, at concentrations ranging from 10 to 50 microM. Beta-tocopherol added simultaneously with alpha-tocopherol prevented both proliferation and protein kinase C inhibition. Protein kinase C inhibition was cell cycle-dependent and it was prevented by okadaic acid, a protein phosphatase inhibitor. Protein kinase C activity measured from aortas of cholesterol-fed rabbits was also inhibited by alpha-tocopherol. By using protein kinase C (PKC) isoform-specific inhibitors and immunoprecipitation reactions it was found that PKC-alpha was selectively inhibited by alpha-tocopherol. Further, an activation of protein phosphatase 2A by alpha-tocopherol was found, which caused PKC-alpha dephosphorylation and inhibition. Ultimately, this cascade of events at the level of cell signal transduction leads to the inhibition of smooth muscle cell proliferation.     

Cloning and disruption of the antigenic catalase gene of Aspergillus fumigatus

Aspergillus fumigatus possesses two catalases (described as fast and slow on the basis of their electrophoretic mobility). The slow catalase has been recognized as a diagnostic antigen for aspergillosis in immunocompetent patients. The antigenic catalase has been purified. The enzyme is a tetrameric protein composed of 90-kDa subunits. The corresponding cat1 gene was cloned, and sequencing data show that the cat1 gene codes for a 728-amino-acid polypeptide. A recombinant protein expressed in Pichia pastoris is enzymatically active and has biochemical and antigenic properties that are similar to those of the wild-type catalase. Molecular experiments reveal that CAT1 contains a signal peptide and a propeptide of 15 and 12 amino acid residues, respectively. cat1-disrupted mutants that were unable to produce the slow catalase were as sensitive to H2O2 and polymorphonuclear cells as the wild-type strain. In addition, there was no difference in pathogenicity between the cat1 mutant and its parental cat1+ strain in a murine model of aspergillosis.     

Visual impairment in Swedish children. III. Diagnoses

PURPOSE: To gain an overview of the spectrum of diagnoses among Swedish visually impaired children. METHODS: An epidemiological study of all known visually impaired children was made by review of medical records. RESULTS AND CONCLUSION: In all we found 2373 children, 0-19 years of age, with an age-specific prevalence of 10.9/10,000. The two largest diagnostic groups included neuro-ophthalmological and retinal diseases. The most frequent disorders were cerebral visual impairment, non-hereditary optic atrophy, retinal dystrophy (when regarded as a general entity), congenital hypoplasia of the optic nerve and congenital cataract. Nystagmus secondary to brain disorder, albinism, congenital nystagmus, retinopathy of prematurity and high myopia were also found in a considerable number of patients. The leading diagnoses in children with WHO-defined childhood blindness were non-hereditary optic atrophy, cerebral visual impairment and retinopathy of prematurity. A large proportion of the children, especially in the groups with neuro-ophthalmological disorders and malformations of the posterior segment had additional impairments, emphasizing the importance of a multi-disciplinary approach when assessing multi-handicapped children.     

In times of survival, the right of silence

The purpose of this study was to assess cortical and cancellous bone responses to unilateral limb immobilization and, subsequently, to remobilization with exercise, in a young adult canine model. Right forelimbs of 14 1-2-year old mongrel dogs were immobilized in a non-weight-bearing position by a bandage for 16 weeks. Six control dogs were untreated. At 16 weeks, seven immobilized and three control dogs were euthanized. The remaining seven immobilized dogs began a recovery protocol consisting of 16 weeks of kennel confinement (without the right forelimb bandaged) followed by 16 weeks of treadmill exercise conducted three times per week. These seven dogs and three control dogs were euthanized at 48 weeks. Bone mineral density of the proximal radii was determined with dual-energy X-ray absorptiometry and humeral middiaphyseal cross-sectional areas were determined with computed tomography. Humeri were tested in cranio-caudal three-point bending to failure. Cancellous bone cores from the lateral humeral condyles had wet apparent density determined and were tested to failure in compression. Mechanical properties, bone density, and cross-sectional areas were compared between immobilized (right forelimb), contralateral weight bearing (left forelimb), and control forelimbs with Kruskal-Wallis and post hoc tests. At 16 weeks, bone mineral density, cortical load, yield, and stiffness as well as cancellous bone failure stress, yield stress, and modulus were significantly lower (p < 0.02) for immobilized limbs than control limbs. Immobilized limb cancellous bone mechanical properties were 28%-74% of control values, and cortical bone mechanical properties were 71%-98% of control values. After 32 weeks of remobilization, cortical and cancellous bone mechanical properties were not different from control values except that cortical bone failure stress and modulus were significantly higher (p < 0.01) between remobilized and control limbs. In summary, 16 weeks of forelimb immobilization was associated with significantly lower mechanical properties, and with greater differences in cancellous than cortical bone properties. Mechanical properties were not different from control values after 32 weeks of recovery that included 16 weeks of treadmill exercise.     

Angular memory and frequency interferometry for mean heightprofiling of a rough surface

The polarimetric angular memory effect is applied to obtain the average topographic height of a rough surface. This novel effect improves the height sensitivity while maintaining a good degree of correlation between the sensors. By using a reference flat surface, the interferometric phase is linearly related to the mean topographic height. The combination of angular memory and wideband frequency interferometry (AMFI) is realized and offers a means to design a robust interferometric system. Extension of the technique to the pulse scattering problem is studied through the two-frequency mutual coherence function, and its time-domain transform provides an equivalent way to obtain the mean topographic height by combining both spatial and temporal diversity. Millimeter-wave (MMW) experiments are conducted with rough surfaces of different statistics and scattering media of different types (gravel, sand, and rough surfaces) to prove the effectiveness of the technique     

Analyses of rhythms of the body temperature in free running in rats

The objective of this study was to determine the disturbances of urea in serum and urine of endurance trained volunteers during prolonged exposure to hypokinesia (decreased number of km/day). The studies during hypokinesia (HK) were performed for 364 days on twenty long-distance runners in the age of 23 to 26 years, with an average peak oxygen uptake, of 66 ml.kg.min-1. All volunteers were divided into two equal groups: Ten volunteers were placed on a continuous regime of exercise 14.8 km/day and served as control subjects (CS). The remaining volunteers were subjected to continuous HK without the use of any preventive measures and were considered as the hypokinetic subjects (HS). For the simulation of the hypokinetic effect, the HS were kept continuously under an average of 2.7 km/day for the duration of the study. Prior to exposure to HK, the HS were on the same exercise regime as the CS. During a 60 day pre-HK period and during the experimental period, urinary excretion of urea, creatinine, sodium, potassium and calcium and concentrations thereof in serum were measured. In the HS the concentrations of urea, creatinine, sodium, potassium and calcium in serum and the rate of excretion thereof in urine increased significantly when compared to the CS. It was concluded that prolonged restriction of muscular activity induces significant disturbances of urea in serum and urine of endurance trained volunteers.