A new alkali-resistant hemoglobin alpha2J Oxford gammaF2 in a Sicilian baby girl with homozygous beta0 thalassemia. (1/297)

A 10-mo-old baby girl with homozygous beta0 thalassemia and alphaJOxford, presenting the clinical picture of homozygous beta thalassemia is described. Hemoglobin electrophoresis showed three bands: the first two with the mobilities of hemoglobin Hb A2 (1%) and Hb F (69%), respectively, the third migrating a little faster than Hb A (30%). About 30% of her alpha chains were J Oxford which, bound to her gamma chains, produced a new alkali-resistant hemoglobin, alpha2 J Oxford gamma F2, which has not been described previously. Hemoglobin synthesis in vitro showed the absence of beta chain synthesis and an alpha/non-alpha ratio of 2. The patient's father was heterozygous for both the Hb J Oxford and beta0 thalassemia genes, the mother a carrier of beta0 thalassemia; four other relatives were carriers of Hb J Oxford, and one was a carrier of beta thalassemia.  (+info)

Clinical analysis and parasite genetic diversity in human immunodeficiency virus/Chagas' disease coinfections in Brazil. (2/297)

To evaluate the possible role of parasitemia on Chagas' disease reactivation in Chagas' disease/human immunodeficiency virus (HIV) coinfection cases and the impact of HIV coinfection on Trypanosoma cruzi genetic diversity, 71 patients with Chagas' disease (34 HIV+ and 37 HIV-) were surveyed. Moreover, 92 T. cruzi stocks from 47 chronic chagasic patients (29 HIV+ and 18 HIV-) were isolated and analyzed by multilocus enzyme electrophoresis and a random amplified polymorphic DNA procedure. High parasitemia appeared to play a major role in cases of Chagas' disease reactivation. In HIV+ patients, the genetic diversity and population structure (clonality) of T. cruzi was similar to that previously observed in HIV- patients, which indicates that immunodepression does not modify drastically genotype repartition of the parasite. There was no apparent association between given T. cruzi genotypes and specific clinical forms of Chagas' disease/HIV associations.  (+info)

Effects on tooth movement of force delivery from nickel-titanium archwires. (3/297)

The aim of this project was to determine the in vivo effects of tooth movement with nickel-titanium archwires on the periodontium during the early stages of orthodontic treatment. The extent of tooth movement, severity of gingival inflammation, pocket probing depth, gingival crevicular fluid (GCF) flow, and the amount of the chondroitin sulphate (CS) glycosaminoglycan (GAG) component of the GCF of one maxillary canine in each of 33 patients treated with a pre-adjusted appliance were measured before and at four stages during the first 22 weeks of treatment. The methods involved the use of a reflex metrograph to determine the type of tooth movement and electrophoresis to quantitate the CS in the GCF. It was found that GCF flow increased after 4 weeks of tooth movement whereas the increase in the amount of CS in the GCF, which is taken to be indicative of periodontal tissue turnover, occurred at the later stage of 10 weeks. Teeth which showed the greatest amount of tooth movement continued to express large amounts of CS in large volumes of GCF until 22 weeks, whilst the CS levels in those teeth moving to a smaller extent declined. These data suggest that nickel-titanium archwires may produce a super-elastic plateau effect in vivo on canine teeth, which are initially displaced from the arch such that large amounts of tooth movement occur in the first 22 weeks of treatment.  (+info)

Genetic analysis of leishmania parasites in Ecuador: are Leishmania (Viannia) panamensis and Leishmania (V.) Guyanensis distinct taxa? (4/297)

In the course of an epidemiologic survey in Ecuador, the following collection of Leishmania stocks was isolated: 28 from patients with clinical signs of leishmaniasis, 2 from sloths, 1 from a dog, and 4 from sand flies. For genetic characterization of these stocks, multilocus enzyme electrophoresis (MLEE) and random amplified polymorphic DNA (RAPD) were used. Twenty six of the 35 stocks were identified as either Leishmania (V.) panamensis or L. (V.) guyanensis, 2 stocks were identified as L. (V.) braziliensis, the 2 stocks from sloths showed specific genotypes, and 5 stocks were characterized as hybrids between L. (V.) braziliensis and L. (V.) guyanensis. These data show that genetic diversity of Leishmania in Ecuador is high and that L. (V.) panamensis/guyanensis is the dominant group in this country. The genetic analysis questioned the distinctness between the two species L.(V.) panamensis and L. (V.) guyanensis, since MLEE and RAPD data did not indicate that L. (V.) panamensis and L. (V.) guyanensis correspond to distinct monophyletic lines. Population genetic analysis performed on the L. (V.) panamensis/guyanensis group favors the hypothesis of a basically clonal population structure.  (+info)

Lutzomyia nuneztovari anglesi (Le pont & Desjeux, 1984) as a vector of Leishmania amazonensis in a sub-Andean leishmaniasis focus of Bolivia. (5/297)

Recently, a new Leishmania amazonensis focus was described in a sub-Andean region (1,450-2,100 meters above sea level) of Bolivia. In this area, three anthropophilic sandfly species were identified: Lutzomyia nuneztovari anglesi Le Pont & Desjeux, 1984, which represented 86-99% of the captures, Lu. galatiae Le Pont et al., 1998, and Lu. shannoni Dyar 1929. Only Lu. nuneztovari anglesi was found naturally infected by flagellates (16 of 1,715 females). Three Leishmania stocks were isolated and analyzed by isoenzyme electrophoresis at 11 loci. No significant isoenzymatic differences were demonstrated between them and 7 stocks isolated from patients from the same area, and previously characterized as L. amazonensis. Moreover, in a simplified protocol, the experimental infection of Lu. nuneztovari anglesi by L. amazonensis was successful in 92% of the surviving specimens. These data are discussed in relation to the Killick-Kendrick criteria. These results strongly suggest that Lu. nuneztovari anglesi is the vector of L amazonensis at Cajuata, Inquisivi, La Paz, Bolivia.  (+info)

Heparin binding peptides co-purify with glycosaminoglycans from human plasma. (6/297)

Glycosaminoglycans (GAGs) are complexed with plasma proteins and proteolysis of plasma reduced the protein-GAG ratio about 140-fold. After dialysis, analysis by gradient PAGE revealed heparinase-1-sensitive GAGs, thus suggesting that heparin could be among the plasma GAGs. However, after dialysis most of the plasma GAGs were still not 'free'. PAGE of peptides resistant to proteolysis showed high molecular weight bands on the two sides of the dialysis membrane despite the 3.5 kDa molecular weight cut-off. Progressive dilution of the sample allowed passage of peptides appearing as high molecular weight bands in the diffusate. We interpret this phenomenon as the presence of low molecular weight peptides that aggregate when concentrated. Peptides on both sides of the membranes bound heparin.  (+info)

DNA sequence analysis: a general, simple and rapid method for sequencing large oligodeoxyribonucleotide fragments by mapping. (7/297)

Several electrophoretic and chromatographic systems have been investigated and compared for sequence analysis of oligodeoxyribonucleotides. Three systems were found to be useful for the separation of a series of sequential degradation products resulting from a labeled oligonucleotide: (I) 2-D electrophoresisdagger; (II) 2-D PEI-cellulose; and (III) 2-D homochromatography. System (III) proved generally most informative regardless of base composition and sequence. Furthermore, only in this system will the omission of an oligonucleotide in a series of oligonucleotides be self-evident from the two-dimensional map. The sequence of up to fifteen nucleotides can be determined solely by the characteristic mobility shifts of its sequential degradation products distributed on the two-dimensional map. With this method, ten nucleotides from the double-stranded region adjacent to the left-hand 3'-terminus and seven from the right-hand 3'-terminus of bacteriophage lambda DNA have been sequenced. Similarly, nine nucleotides from the double-stranded region adjacent to the left-hand 3'-terminus and five nucleotides from the right-hand terminus of bacteriophage phi80 DNA have also been sequenced. The advantages and disadvantages of each separation system with respect to sequence analysis are discussed.  (+info)

DNA sequence analysis: a formula to predict electrophoretic mobilities of oligonucleotides on cellulose acetate. (8/297)

A simple method has recently become available for sequence analysis of large oligonucleotide fragments. Sequences are derived from the characteristic mobility shifts of the sequential partial degradation products of the oligonucleotide on two dimensional homochromatography. We have now developed an empirical formula for predicting the relative mobilities of each of the partial products in the first dimension (electrophoresis on cellulose acetate gel). The formula allows a more precise interpretation of the sequence of the oligonucleotide. It eliminates the ambiguities present in the method previously reported for sequence analysis by simple inspection of the mobility shifts. In order to amplify the mobility shifts so that they may be more easily and accurately measured, methods have been developed for preparing and fractionating the oligonucleotides on 40 x 40 cm DEAE-cellulose plates. Both improvements have proven valuable for direct sequence analysis by mapping.  (+info)