28 research outputs found
Polymicrobial infections and biofilms in women's health Gahro Expert Group Meeting Report
info:eu-repo/semantics/publishedVersio
Reduced Mass and Diversity of the Colonic Microbiome in Patients with Multiple Sclerosis and Their Improvement with Ketogenic Diet
Background: Colonic microbiome is thought to be involved in auto-immune
multiple sclerosis (MS). Interactions between diet and the colonic microbiome
in MS are unknown. Methods: We compared the composition of the colonic
microbiota quantitatively in 25 MS patients and 14 healthy
controls.Fluorescence in situ hybridization (FISH) with 162 ribosomal RNA
derived bacterial FISH probes was used. Ten of the MS patients received a
ketogenic diet for 6 months. Changes in concentrations of 35 numerically
substantial bacterial groups were monitored at baseline and at 2, 12, and
23/24 weeks. Results: No MS typical microbiome pattern was apparent.The total
concentrations and diversity of substantial bacterial groups were reduced in
MS patients (P < 0.001). Bacterial groups detected with EREC (mainly
Roseburia), Bac303 (Bacteroides), and Fprau (Faecalibacterium prausnitzii)
probes were diminished the most. The individual changes were multidirectional
and inconsistent. The effects of a ketogenic diet were biphasic. In the short
term, bacterial concentrations and diversity were further reduced. They
started to recover at week 12 and exceeded significantly the baseline values
after 23–24 weeks on the ketogenic diet. Conclusions: Colonic biofermentative
function is markedly impaired in MS patients.The ketogenic diet normalized
concentrations of the colonic microbiome after 6 months
Influence of nonmetallic inclusions on the resistance of metal weld to brittle fractures
According to statistics, up to 80% of all fixed metal structure accidents are associated with welded joints. However, most of the emergency destructions, usually caused by non-metallic inclusions in the weld metal, are fragile. The probability of brittle fracture decreases with increasing plasticity. And plasticity, that depends on the mobility of dislocations to a great degree, decreases with temperature decrease and increase in the strain rate. The plasticity of the metal is a structurally sensitive property and depends on the type of crystal lattice that determines
the number of densely packed directions and slip planes. Low-alloy steels, mainly used in welded steel structures, have a volume-centered cubic lattice with a relatively small number of planes and sliding direction. These steels are ductile at relatively high temperatures and become brittle at negative temperatures.
The only way to improve the ductility of the metal without significantly reducing its strength is to grind grain. One of the effective ways to obtain finegrained structure of the weld metal is to introduce modifiers into the weld pool. The modifiers should be in the form of refractory compounds (oxides, carbides,
nitrides), which in the crystallization zone of the weld pool are crystallization centers and increase the number of grains per unit volume. Studies of the modification of the crystallizing metal in the conditions of casting and fusion welding have shown that the melt overheating reduces the effect of modification. In electric
arc welding with an arc temperature of more than 6000K, the danger of deactivation of the modifier is high. One way to reduce overheating and improve the efficiency of modifiers in welding is the introduction of modifying particles in the weld pool in combination with more massive granules in the form of chopped wire, serving as micro-refrigerators. This method, called welding with a metalchemical additive (MCA), is successfully used in bridge construction. Modification of the weld pool with refractory particles, along with the positive effect of grinding grain in the weld there is also a negative moment: modifying particles that remain in the weld in the form of non-metallic inclusions are stress concentrators and can become centers of crackin
New technology for production of granular adding material with nanomodifying additives for steel arc welding
The chemical analysis of metal seam showed that introduction of titanium dioxide with MCA intensifies transition of Al2O3 from slag into metal pool and provides double concentration of titanium in the seam compared to the one which appears in the interaction of bathtub with melted flux AH-47 without TiO2 additives. The presence of oxides of titanium and aluminium of endogenous origin in the melt leads to formation of refractory particles with the center of TiO2 and Al2O3 in it. These particles are the centers of crystallization in the tail part of the molten pool and they remain in seam metal in the form of evenly distributed fine nonmetallic inclusions, which have crystallographic affinity with a matrix
(α-iron). That provides the fine-grained seam structure with the raised and stable strength characteristics. This article compares the existing and developed technologies for production of MCA. The granulometric analysis of the powder TiO2 has demonstrated that when MCA is processed in the planetary mill, particles
of titanium dioxide are crushed to a nanodimensional order. It is shown that the preparation of MCA in high-energy planetary mill (due to double increase of durability in coupling of the modifier with granulate) provides its stable structure, increases the cold resistance (20–25%) and stability of strength characteristics along the length of welded seam. Metalgraphic researches determined that the fine-grained structure which linear size of grain is twice smaller than the one obtained in the old technology welding is formed in a seam. However the direct introduction of nanomodifiers in a molten pool through the flux or an electrode
wire is not efficient because of their deactivation and high temperature in welding zone. Therefore it was offered to use modifiers in the mix with the cooling macroparticles in case of automatic welding of a bridge metalware under flux using
metalchemical additive (MCA). The MCA consists of a chopped welding wire (granulate), the powdering modifying chemical additive TiO2 in the mixer with the displaced rotation axis «piyanay bochka» accorfint to the existing technology.
However this MCA's technology doesn't provide the stable durability of modifier's coupling with the granulate's surface and it is not able to control its structure under production conditions that, certainly, negatively affects on stability of welded connections' properties. Therefore one of the main task in this research
was to improve the existing technology to increase durability of the modifier' coupling with granulate. Welding is one of the main technological methods to connect details and nodes in production process. However 70–80% of metalware destruction occuring in operational process are related to welded connections. These destructions are mainly fragile. The increased firmness of welded connections against the fragile destruction is needed due to development of northern and east regions in Russia. The most perspective method to increase cold resistance of welded connections is the crush of seam metal grain by means of nanomodification
Prevalence of Ureaplasma spp. and Mycoplasma hominis in healthy women and patients with flora alterations
The Prevalence of High Carcinogenic Risk of HPV Genotypes among HIV-Positive and HIV-Negative MSM from Russia
Objective. Men who have sex with men (MSM) have a high risk of lifelong anal cancer caused by high-risk human papillomavirus (HR HPV) infections. The aim of this study was to investigate the prevalence of anal canal HR HPV infection among men who have sex with men (MSM) with and without HIV infection in Moscow (Russia). We evaluated associations of some HIV coinfections (HSV and CMV) and HPV distribution among MSM with and without HIV infection. Methods. Two groups of HIV-positive (n = 60) and HIV-negative (n = 60) MSM were evaluated in the study. Fourteen high-risk (HR) HPV types, HSV1/2, and CMV were investigated in men anal swabs. Results. HR HPVs were found with nearly the same frequency of 66.7% in both groups: HIV-positive and HIV-negative MSM. HIV-positive status was statistically associated with the presence of several (more than two) HPV types (p=0.044). The most prevalent HR HPV genotypes were HPV18, HPV16, HPV56, and HPV33 for HIV-positive MSM and HPV56, HPV51, HPV66, and HPV16 for HIV-negatives. We found a statistically significant association of five HR HPV types with HIV status of MSM: HPV16 (p=0.028), HPV18 (p=0.00006), HPV58 (p=0.003), HPV33 (p=0.019), and HPV39 (p=0.026). The frequency of HSV1 (1.7%) and HSV2 (10%) infections and CMV (3.3%) infection was evaluated in the group of HIV-positive MSM. The frequency of HSV1 (5%) and HSV2 (6.7%) infections and CMV (0%) infection was evaluated, as well, in the group of HIV-negative MSM. Conclusion. Multiple HPV genotypes were detected significantly more often than single HPV genotype in the group of HIV-positive MSM. According to our data, 25% of HIV-positive MSM have HPV39; this is the only one of the five types of HR HPV (16, 18, 58, 33, and 39) associated with this group of MSM that has not yet been included in the HPV vaccines available on the market
Vulvovaginal candidiasis : histologic lesions are primarily polymicrobial and invasive and do not contain biofilms
BACKGROUND: The recent demonstration of a vaginal biofilm in bacterial vaginosis and its postulated importance in the pathogenesis of recurrent bacterial vaginosis, including relative resistance to therapy, has led to the hypothesis that biofilms are crucial for the development of vulvovaginal candidiasis. The histopathology and microbial architecture of vulvovaginal candidiasis have not been previously defined; neither has Candida, containing biofilm been reported in situ. The present study aimed at clarifying the histopathology of vulvovaginal candidiasis including the presence or absence of vaginal biofilm.
STUDY DESIGN: In a cross-sectional study, vaginal tissue biopsies were obtained from 35 women with clinically, microscopically, and culture-proven vulvovaginal candidiasis and compared with specimens obtained from 25 healthy women and 30 women with active bacterial vaginosis. Vaginal Candida infection was visualized using fluorescent in situ hybridization with ribosomal gene-based probes.
RESULTS: Candida microorganisms were confirmed in 26 of 35 biopsies obtained from women with vulvovaginal candidiasis; however, Candida containing biofilm were not detected in any of the cases. Histopathological lesions were exclusively invasive and accompanied by co-invasion with Gardnerella or Lactobacillus species organisms.
CONCLUSION: Histopathological lesions of vulvovaginal candidiasis are primarily invasive in nature and polymicrobial and do not resemble biofilms. The clinical significance of Candida tissue invasion is unknown
Utility of microscopic techniques and quantitative real-time polymerase chain reaction for the diagnosis of vaginal microflora alterations
Evaluation of the new AmpliSens multiplex real-time PCR assay for simultaneous detection of Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, and Trichomonas vaginalis
In this study, we performed an evaluation of the new CE-marked multiplex real-time AmpliSens N.gonorrhoeae/C.trachomatis/M.genitalium/T.vaginalis-MULTIPRIME-FRT PCR assay compared to APTIMA tests, i.e., APTIMA COMBO 2 assay, APTIMA Trichomonas vaginalis assay (FDA-approved), and two different APTIMA Mycoplasma genitalium assays (research use only; one of them only used for discrepancy analysis). Vaginal swabs (n = 209) and first-void urine (FVU) specimens from females (n = 498) and males (n = 554), consecutive attendees (n = 1261) at a dermatovenerological clinic in Sweden, were examined. The sensitivity of the AmpliSens PCR assay for detection of C. trachomatis (6.3% prevalence), M. genitalium (5.7% prevalence), N. gonorrhoeae (0.3% prevalence), and T. vaginalis (0.08% prevalence) was 97.5% (95% confidence interval (CI): 91.2-99.6%), 81.9% (95% CI: 70.7-89.7%), 100% (95% CI: 40.2-100%) and 100% (95% CI: 16.5-100%), respectively. The specificity of the AmpliSens PCR assay was 100% (95% CI: 99.6-100%) for all agents. The analytical sensitivity and specificity for N. gonorrhoeae detection was excellent, i.e., 55 international gonococcal strains detected and 135 isolates of 13 non-gonococcal Neisseria species were negative. In conclusion, the multiplex real-time AmpliSens N.gonorrhoeae/C.trachomatis/M.genitalium/T.vaginalis-MULTIPRIME-FRT PCR assay demonstrated high sensitivity and excellent specificity for the detection of C. trachomatis, N. gonorrhoeae, and T. vaginalis, and excellent specificity but suboptimal sensitivity for M. genitalium detection