Massive antenatal fetomaternal hemorrhage: evidence for long-term survival of fetal red blood cells

BACKGROUND: Massive fetomaternal hemorrhage (FMH) can lead to life-threatening anemia. Quantification based on flow cytometry with anti-hemoglobin F (HbF) is applicable in all cases but underestimation of large fetal bleeds has been reported. A large FMH from an ABO-compatible fetus allows an estimation of the life span of fetal red blood cells (RBCs) in the maternal circulation. CASE REPORT: The mother went to the obstetrician twice antepartum owing to symptoms assumed to be preeclampsia; that, however, was not found. She later delivered by cesarean section owing to diminished fetal movements. No fetal weight gain was observed during the last 2 weeks of pregnancy. STUDY DESIGN AND METHODS: Fetal RBCs were quantified by flow cytometry with anti-HbF, anti-Fy(a), anti-s, and anti-Jk(b) on a regular basis. RESULTS: The infant had anemia at delivery and an FMH was determined to be 314 +/- 17 mL (+/- SD) of whole blood. It is assumed that the two antenatal visits were associated with the FMH. Postpartum follow-up showed that fetal RBCs in the maternal circulation were detectable with anti-HbF up to 119 days. Quantification by flow cytometry based on anti-HbF was in agreement with quantification based on anti-Fy(a), anti-s, and anti-Jk(b), although they were less sensitive. CONCLUSION: ABO-compatible fetal RBCs from an FMH had a life span in the maternal circulation close to that of adult RBCs.     

High-efficiency generation of antibiotic-resistant strains of Streptococcus pneumoniae by PCR and transformation

We designed a method by which to generate antibiotic-resistant strains of Streptococcus pneumoniae at frequencies 4 orders of magnitude greater than the spontaneous mutation rate. The method is based on the natural ability of this organism to be genetically transformed with PCR products carrying sequences homologous to its chromosome. The genes encoding the targets of ciprofloxacin (parC, encoding the ParC subunit of DNA topoisomerase IV), rifampin (rpoB, encoding the beta subunit of RNA polymerase), and streptomycin (rpsL, encoding the S12 ribosomal protein) from susceptible laboratory strain R6 were amplified by PCR and used to transform the same strain. Resistant mutants were obtained with a frequency of 10(-4) to 10(-5), depending on the fidelity of the DNA polymerase used for PCR amplifications. Ciprofloxacin-resistant mutants, for which the MICs were four-to eightfold higher than that for R6, carried a single mutation of a residue in the quinolone resistance-determining region: S79 (change to A, F, or Y) or D83 (change to N or V). Rifampin-resistant strains, for which the MICs were at least 133-fold higher than that for R6, contained a single mutation within cluster I of rpoB: S482 (change to P), Q486 (change to L), D489 (change to V), or H499 (change to L or Y). Streptomycin-resistant mutants, for which the MICs were at least 64-fold higher than that for R6, carried a mutation at either K56 (change to I, R, or T) or K101 (change to E). PCR products obtained from the mutants were able to transform R6 to resistance with high efficiency (>10(4)). This method could be used to efficiently obtain resistant mutants for any drug whose target is known.     

Fasciola hepatica phenotypic characterization in Andean human endemic areas: valley versus altiplanic patterns analysed in liver flukes from sheep from Cajamarca and Mantaro, Peru

Fascioliasis is a zoonotic parasitic disease caused by Fasciola hepatica and Fasciola gigantica. Of both species, F. hepatica is the only one described in the Americas, mainly transmitted by lymnaeid snail vectors of the Galba/Fossaria group. Human fascioliasis endemic areas are mainly located in high altitude areas of Andean countries. Given the necessity to characterize F. hepatica populations involved, the phenotypic features of fasciolid adults infecting sheep present in human fascioliasis endemic areas were analysed in the Cajamarca Valley and Mantaro Valley (valley transmission patterns) and the northern Bolivian Altiplano (altiplanic transmission pattern). A computer image analysis system (CIAS) was applied on the basis of standardized measurements. The aforementioned highland populations were compared to standard lowland natural and experimental populations of European origin. Liver fluke size was studied by multivariate analyses. Two phenotypic patterns could be distinguished in F. hepatica adult size: the valley pattern (Cajamarca and Mantaro, Peru) and the altiplanic pattern (northern Altiplano, Bolivia). Results showed that the Andean valley population and European standard populations presented a phenotypic homogeneity. The Altiplano population showed a large size range with a pronouncedly lower minimum size indicating that uterus gravidity is reached at a smaller size than in valley populations. The results of this study demonstrate that there is no apparent relationship between the shape of fasciolid adults with regard to altitudinal difference or geographical origin and that allometry-free shape appears as a more stable trait than size in fasciolid species. Results are analysed in terms of intensity/crowding effect aspects and permanent/seasonal transmission characteristics.     

Identification of Acinetobacter species: Is Bruker biotyper MALDI-TOF mass spectrometry a good alternative to molecular techniques?

Acinetobacter spp. has become a leading cause of nosocomial infection in recent years. Phenotypic similarities between the species in the genus have made it difficult to identify them clearly using routine diagnostic methods. Consequently, more relevant species have been grouped together as Acinetobacter calcoaceticus-Acinetobacter baumannii complex (A. baumannii, A. calcoaceticus, Acinetobacter genospecies 3 and A. genospecies 13TU). However, there are other species that may also have clinical significance. The aims of this study were to establish the usefulness of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) for the identification of Acinetobacter species by comparison with two molecular techniques, as well as determine the role of species other than A. baumannii play in nosocomial infections.The study sample comprised 109 clinical isolates of Acinetobacter. They were all identified using MALDI-TOF MS. Thirty-one isolates of these were also tested using comparator amplification of bla(OXA51-like) and sequencing of the rpoB gene. Different score values in MALDI-TOF MS revealed 87 A. baumannii, 19 A. genospecies 3, 1 Acinetobacter junii, 1 Acinetobacter baylyi and 1 Acinetobacter tjernbergiae. Amplification of bla(OXA-51)(-like) showed products in 85 isolates. Sequencing of the rpoB gene allowed us to identify all the 31 isolates analyzed: 16 were consistent with the results of spectrometry and 15 were not. This work showed that molecular techniques are still needed to identify the different species of clinical interest within the genus Acinetobacter. Although, MALDI-TOF MS could be useful to identify A. baumannii but not other species in the genus.     

Antioxidant Activities of Chokeberry Extracts and the Cytotoxic Action of Their Anthocyanin Fraction on HeLa Human Cervical Tumor Cells

Abstract The present study evaluates the antioxidant activity of two Aronia melanocarpa cultivars-Viking and Aron-and of Aronia prunifolia hybrid in relationship with their phytochemical composition regarding the contents of total phenolics, flavonoids, procyanidins, and monomeric anthocyanins. The antioxidant capacity of the mentioned extracts of chokeberries was evaluated through five complementary assays: 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), H(2)O(2) scavenging potential, oxygen radical absorbance capacity, ferric reducing antioxidant power, and cupric ion reducing antioxidant capacity. A. prunifolia hybrid was found to have the highest antioxidant activity and to be the richest in polyphenols, procyanidins, and anthocyanins compared with the A. melanocarpa cultivars. A good correlation was observed between antioxidant activity and total procyanidin and anthocyanin content. Cyanidin glycosides inhibited HeLa human cervical tumor cell proliferation and increased generation of reactive oxygen species after 48?h of treatment, suggesting that they could be responsible for the antiproliferative activity. These results may be significant for industry concerning food quality and disease prevention.     

Risk of gallstone disease in advanced chronic phase of fascioliasis: an experimental study in a rat model

In Wistar rats experimentally infected with Fasciola hepatica, the association between time of infection, number of flukes, rat weight, and serum lipid levels and the risk of developing pigment stones in the main bile duct was examined using data obtained at 100, 200, 300, 400, and 500 days postinfection. Gallstone presence increased with infection time. The relative risk of gallstone disease increased when the number of flukes per rat and rat weight increased. The presence of gallstones was associated with serum high-density lipoproteins and triglyceride levels. In a multivariate analysis, the association between gallstones and rat weight disappeared after adjustment for serum lipids. The absence of an effect of rat weight independent from serum lipids suggests that serum lipids are more closely linked to gallstone pathogenesis than is overweight. The presence of gallstones was strongly associated with the number of flukes located in the bile duct. A high risk of developing gallstones may be expected in human subjects inhabiting areas where F. hepatica is highly endemic and where high egg outputs detected in humans suggest that liver fluke burdens may also be very high.