Impairment of intramacrophagic Brucella suis multiplication by human natural killer cells through a contact-dependent mechanism

Brucella spp. are facultative intracellular bacteria that can establish themselves and cause chronic disease in humans and animals. NK cells play a key role in host defense. They are implicated in an early immune response to a variety of pathogens. However, it was shown that they do not control Brucella infection in mice. On the other hand, NK cell activity is impaired in patients with acute brucellosis, and recently it was demonstrated that human NK cells mediate the killing of intramacrophagic Mycobacterium tuberculosis in in vitro infection. Therefore, we have analyzed the behavior of Brucella suis infecting isolated human macrophages in the presence of syngeneic NK cells. We show that (i) NK cells impair the intramacrophagic development of B. suis, a phenomenon enhanced by NK cell activators, such as interleukin-2; (ii) NK cells cultured in the presence of infected macrophages are highly activated and secrete gamma interferon and tumor necrosis factor alpha; (iii) impairment of bacterial multiplication inside infected cells is marginally associated with the cytokines produced during the early phase of macrophage-NK cell cocultures; (iv) direct cell-to-cell contact is required for NK cells to mediate the inhibition of B. suis development; and (v) inhibition of B. suis development results from an induction of NK cell cytotoxicity against infected macrophages. Altogether, these findings show that NK cells could participate early in controlling the intramacrophagic development of B. suis in humans. It seems thus reasonable to hypothesize a role for NK cells in the control of human brucellosis. However, by impairing the activity of these cells in the acute phase of the illness, the pathogen should avoid this control.     

Quantification of sequence exchange events between PMS2 and PMS2CL provides a basis for improved mutation scanning of lynch syndrome patients

Heterozygous mutations in PMS2 are involved in Lynch syndrome, whereas biallelic mutations are found in Constitutional mismatch repair‐deficiency syndrome patients. Mutation detection is complicated by the occurrence of sequence exchange events between the duplicated regions of PMS2 and PMS2CL. We investigated the frequency of such events with a nonspecific polymerase chain reaction (PCR) strategy, coamplifying both PMS2 and PMS2CL sequences. This allowed us to score ratios between gene and pseudogene‐specific nucleotides at 29 PSV sites from exon 11 to the end of the gene. We found sequence transfer at all investigated PSVs from intron 12 to the 3′ end of the gene in 4 to 52% of DNA samples. Overall, sequence exchange between PMS2 and PMS2CL was observed in 69% (83/120) of individuals. We demonstrate that mutation scanning with PMS2‐specific PCR primers and MLPA probes, designed on PSVs, in the 3′ duplicated region is unreliable, and present an RNA‐based mutation detection strategy to improve reliability. Using this strategy, we found 19 different putative pathogenic PMS2 mutations. Four of these (21%) are lying in the region with frequent sequence transfer and are missed or called incorrectly as homozygous with several PSV‐based mutation detection methods. Hum Mutat 31:578–587, 2010. © 2010 Wiley‐Liss, Inc.     

Nanocomposites of Microbial Polyglutamic Acid and Nanoclays Compatibilized by Organophosphonium Surfactants

Ionic coupling of bacterial poly(γ‐glutamic acid) (PGGA) with alkyltrimethylphosphonium surfactants is reported to render comb‐like PGGA complexes with a biphasic‐layered structure displaying periodicity at the nanoscopic scale. In this work, nanocomposites made of PGGA and montmorillonite, and covering a wide variety of compositions, are prepared by using either dodecyl‐ or eicosyl‐trimethylphosphonium surfactant as a third component with a double purpose, that is, ionic complexation of PGGA and organo‐modification of the nanoclay. Thermogravimetric analysis ascertains the compositions of these three‐component nanocomposites and evidences their excellent thermal stability. The nanocomposite structure with PGGA and clay more or less intercalated according to composition and thermal history is evidenced by both X‐ray diffraction and transmission electron microscopy. Simultaneous thermal SAXS/WAXS analysis at real time reveals extensive intermixing of the two phases that become notably enhanced by heating treatment. Thermal transition characteristics of the surfactant–PGGA complex are not significantly altered in the nanocomposites, but elastic moduli and strength to yield are found to increase proportionally to the content of clay.     

Antigenic and genomic relation between human influenza viruses that circulated in Argentina in the period 1995-1999 and the corresponding vaccine components.

BACKGROUND: The analysis of epidemic influenza virus has been focused on antigenic and genomic characterization of the hemagglutinin (HA) glycoprotein in order to detect new variants for the recommendation of the vaccine strains in each season. Since October 1998, WHO organized a second meeting to evaluate the vaccine formula for the southern hemisphere. OBJECTIVES: (a) Present the antigenic and genomic characterization of influenza strains obtained from the Argentina surveillance network, (b) compare between strains collected in Argentina and other countries with the vaccine formula strains used in each season. STUDY DESIGN: Influenza strains were collected during a 5-year period (1995-1999). Initially, laboratory diagnosis was done by immunofluorescence (IF) assay on clinical samples, followed by viral isolation in Madin-Darby canine kidney (MDCK) cells. The isolates were characterized antigenically by hemagglutination-inhibition (HI) assay with post-infection ferret antisera. The genomic characterization consisted on RT-PCR followed by sequencing of the HA1 portion of the HA gene. The comparison between reference and circulating strains was analyzed by the construction of phylogenetic trees. RESULTS: The H3N2 circulating strains matched the corresponding vaccine component only in 1999, the first year when a vaccine recommended specifically for the southern hemisphere was used. Besides, H1N1 circulating strains matched the corresponding vaccine component only in 1998. Regarding to influenza B, only in 1995, the circulating strains showed no match to the B vaccine component. CONCLUSIONS: The results showed the usefulness of an intensified influenza laboratory surveillance to access the correct vaccine and the importance of having the necessary tools to characterize the circulating strains.     

Barbed Suture versus Conventional Suture for Vaginal Cuff Closure in Total Laparoscopic Hysterectomy: Randomized Controlled Clinical Trial

Study ObjectiveTo determine the surgical time, suture time, presence of postoperative dyspareunia, and complications that occur after closing the vaginal cuff with a barbed suture compared with conventional suture.DesignA randomized, controlled clinical trial (Canadian Task Force classification I).SettingPrivate gynecologic clinic in Medellin, Colombia.PatientsOne hundred fifty women who underwent total laparoscopic hysterectomy for benign pathology.InterventionsThe patients underwent total laparoscopic hysterectomy with intracorporeal closure of the vaginal cuff and were randomized to 2 groups, 1 using a barbed suture (V-Loc 90; Medtronic/Covidien, New Haven, CT) and 1 using polyglactin 910 (coated Vicryl suture; Ethicon/Johnson & Johnson, New Brunswick, NJ).Measurements and Main ResultsThe total operative time, closing time of the vaginal vault, presence of complications in the cuff, and incidence of postoperative dyspareunia were recorded. The patients were evaluated at a postoperative office visit 2 weeks after the procedure and by telephone interview at 24 weeks. Seventy-five patients were included in the barbed suture group and 75 patients in the polyglactin 910 group. The average time to complete the suture of the vaginal cuff was 12.01 minutes (± 5.37 standard deviation) for the barbed suture group versus 13.49 minutes (± 6.48) in the polyglactin 910 group (95% confidence interval, –.44 to 3.4; p = .130). Blood loss was 31.56 ± 22.93 mL in the barbed suture group versus 30.82 ± 21.75 mL in the polyglactin 910 group (95% confidence interval, –7.95 to 6.47; p = .840). The frequency of postoperative events such as hematoma, cellulitis, cuff dehiscence, fever, emergency consultation, and hospitalization was not statistically significant between groups. No statistically significant difference was found regarding deep dyspareunia at 24 postoperative weeks.ConclusionNo differences were found in surgical time or frequency of adverse events when comparing patients after vaginal cuff closure with barbed suture versus polyglactin 910.     

Analysis of C-850T and G-308A polymorphisms of the tumor necrosis factor-alpha gene in Maya-Mestizo women with preeclampsia.

OBJECTIVE: To determine whether polymorphisms in the TNF-alpha promoter gene are associated with preeclampsia. METHODS: 105 women with preeclampsia and 200 controls were genotyped for the G-308A and C-850T polymorphisms by RFLP. Differences in allele, genotype, and haplotype frequencies between groups were assessed. RESULTS: The genotypic and allelic distribution of both polymorphisms was similar between groups. Moreover, the estimated overall pair of loci haplotype frequencies did not differ significantly. CONCLUSION: We did not find any association between these polymorphisms and the risk for preeclampsia. However, we found that both the genotypic and allelic distribution in our population differed from those reported in other populations.     

Preterm infants' early developmental status is associated with later developmental outcome

Aim: To assess the development of preterm infants from 40 weeks gestational age to 18 months corrected age to identify early predictors of later development. Methods: Fifty‐one infants were involved. Infant development was assessed at 40 and 44 weeks gestational age with the Brazelton neonatal behavioral assessment scale and a self‐regulation scale and at 3, 6, 10, 18 months corrected age with the Bayley Scales of Infant Development. The quality of general movements was assessed at 1 and 3 months corrected age and maternal attachment style at infant’s age of 6 months corrected age with the Relation Scale Questionnaire. Results: At term age and 1‐month corrected age, preterm infants were less mature and had lower levels of self‐regulation than full‐term infants. At 3 months corrected age, a higher proportion of preterm infants (43%) had mildly abnormal motor quality compared to the general population (25%). At all follow‐ups, preterm infants had delayed mental, motor and behavioural development, which was associated with the level of self‐regulation, motor quality and maternal attachment style. Maternal education level was the most predominant background factor related to infant development. Conclusion: Preterm infants show early‐in‐life deviations in self‐regulation, motor quality and development. These deviations are risk factors for later optimal functioning.     

Molecular pathology of well-differentiated thyroid carcinomas

The newly discovered molecular features of well-differentiated thyroid carcinomas derived from follicular cells are reviewed, within the frame of the 2004 WHO classification of thyroid tumours, under the following headings: “Follicular carcinoma”, “Papillary carcinoma”, “Follicular variant of papillary carcinoma” and “Hürthle cell tumours”. A particular emphasis is put on the meaning of PAX8–PPARγ rearrangements, RAS and BRAF mutations, and deletions and mutations of mitochondrial genes and of nuclear genes encoding for mitochondrial enzymes, for thyroid tumorigenesis.     

Immunoglobulin M Enzyme-Linked Immunosorbent Assay Using Recombinant Polypeptides for Diagnosis of Dengue

We demonstrate that a mixture of four recombinant dengue virus E polypeptides corresponding to the N-terminal region of the envelope protein from all serotypes substitutes for standard antigens in two immunoglobulin M enzyme-linked immunosorbent assay formats with 100% concordance, making these polypeptides a useful and accessible reagent for serological diagnosis of dengue in endemic countries.