222 research outputs found
The microbial load and the severity of morphological changes in the prostate during infection with various titers of uropathogens: a comparison of data from an animal model study
Introduction. It has been established in an animal model that coagulase-negative staphylococci (Staphylococcus haemolyticus) and anaerobes (Peptococcus niger) cause the development of an acute inflammatory process in the prostate when inoculated with 103 CFU/ml. At the same time, data have been published indicating the pathogenic potential of these microorganisms on a titer of 102 CFU/ml. But it was confirmed for the model of acute obstructive pyelonephritis. In addition, the characteristics of the formation of the inflammatory response at different times were determined, which require detailed verification and comparative characteristics with those during infection with a causative uropathogen (Escherichia coli).Objective. Based on the results of the experiment, to carry out: 1) an evaluation of the relationship between the dynamics of microbial load and the degree of pathomorphological changes in prostate tissues during infection with various uropathogens in a titer of 103 CFU/ml; 2) an evaluation of the degree of microbial load and severity of histological changes in prostate tissues on follow-up day 7 with transurethral infection with various uropathogens in a subpathogenic titer of 102 CFU/ml; 3) a fundamental comparative analysis of the indicators of contamination and the severity of inflammatory changes on follow-up day 7 after the inoculation of various uropathogens in titers of 102 and 103 CFU/ml.Materials and methods. The animal model was performed using the FELASA and ARRIVE guidelines. Lab animals: 20 New Zealand rabbits. Uropathogens: E. coli, S. haemolyticus, and P. niger. Infectious titers: 102.3 cfu/ml. Uropathogen inoculation technique: topical transurethral. Randomization: all laboratory animals were divided into 4 groups depending on the uropathogen (3 experimental, 1 control). Follow-up periods: day 1, 3, 7 and 14 for a titer of 103 CFU/ml, and day 7 for a titer of 102 CFU/ml. At the end of the follow-up, euthanasia and autopsy were performed with the extraction of the urogenital organ complex. Hereafter, biopsies were taken from various parts of the prostate. Cultural and histological studies of prostate tissues were carried out using standard methods. The results were analyzed using Statistica 10.2 (StatSoft Inc., Tulsa, OK, USA) and GraphPad Prism 9 (GraphPad Software Inc., Graphpad Holdings LLC, San Diego, CA, USA) programs through descriptive and nonparametric statistics.Results. Bacterial contamination of prostate tissue was determined in all cases of infection with differences (p < 0.05) in some indicators between the E. coli and P. niger groups at different observation periods, but only in the case of inoculation of the test titer of 103 CFU/ml. Histological evaluation of prostate tissues after inoculation with 103 CFU/ml verified the presence of acute destructive changes in the prostate from the follow-up day 1, which were more pronounced in the S. haemolyticus and E. coli groups. However, similar characteristics of the development of the inflammatory process in the form of hyper-eosinophilic infiltration in the early stages and pronounced congestion of the prostatic glands were identified in the S. haemolyticus and P. niger groups. Comparison of trends in dynamic changes of microbial load (rise / decline) and severity of pathological changes (increase / resolution) in prostate tissues in established follow-up periods showed the presence of relative synchronization of trends (from days 1 to 7) in the S. haemolyticus and P. niger groups, and complete synchronization in the E. coli group. When comparing the median microbial load of the prostate on the follow-up day 7, no intergroup (p > 0.05) differences were found both in cases of infection with a titer of 103 CFU/ml, and when compared with the data on contamination for a test titer of 102 CFU/ml, at the same time observations. At once, when E. coli and S. haemolyticus were infected at a subpathogenic titer of 102 CFU/ml, inflammatory changes were recorded that had a mild diffuse character, in relation to those after inoculation of these pathogens in a titer of 103 CFU/ml. In turn, P. niger induced the development of low-intensity focal alteration in isolated areas of prostate tissues.Conclusions. Detailed analysis of culture and histological data showed that E. coli, S. haemolyticus and P. niger have significant pathogenic potential at titer of 103 CFU/ml. In turn, when the titer decreases to 102 CFU/ml, E. coli and S. haemolyticus retain their pathogenic potential, but the severity of the inflammatory reaction is significantly reduced. It was also found that a change in bacterial contamination affects the severity of the inflammatory process in all groups during seven follow-up days at a given test titer
Influence of vesicourethral segment reconstruction techniques in radical prostatectomy on urinary continence: evaluation of immediate and long-term outcomes
Introduction. Currently, various methods and modifications of radical prostatectomy (RP) have been developed and tested, aimed at preventing and minimizing the development of urinary incontinence (UI). However, UI remains an urgent problem in patients who undergo RP, especially at the early follow-up stages.Objective. To evaluate and compare the effectiveness of modified reconstructive techniques for vesicourethral anastomosis in radical prostatectomy for the prevention of urinary incontinence with respect to the standard technique at different follow-up periods.Materials and methods. Design: single-centre, clinical, simple, comparative, parallel-group study with retrospective and prospective material evaluation, conducted in 2017 â 2022. Patients: men with verified prostate cancer cT1a â 2cN0 â xM0 without decompensated comorbidities. Age: 45 â 78 years. Retrospective part â group (G) 1: 90 patients who underwent non-nerve-sparing open retropubic RP with a "classic" vesicourethral anastomosis (VUA). Prospective part â G2: 46 patients who underwent similar surgery with modified VUA in two variations: without and with prostatic urethra-sparing â G2a (n = 25) and G2b (n = 21), respectively. Initial examination: standard preoperative laboratory and instrumental examination, assessment of lower urinary tract symptoms (LUTS) using the IPSS-QoL questionnaire. Follow-up examination: objective evaluation of UI according to established criteria and subjective assessment using the ICIQ-SF questionnaire, tracking the dynamics of LUTS using IPSS-QoL. Follow-up periods: 0-point (after catheter removal), 1, 3, 6, and 12 months (exit-point); the dynamics of recovery of urinary continence (UC) was determined monthly. Statistical analysis: Statistica ver.10.0 (StatSoft Inc., Tulsa, OK, USA) using non-parametric methods (CL p < 0.05 at a = 0.05)Results. Preoperative demographic, questionnaire and instrumental statistics did not differ (p > 0.05) between the groups, confirming the homogeneity of the samples. After RP, the urethral catheter was removed in a period of 7 to 21 days. There was no difference (p > 0.05) in the duration of drainage between the groups. Total urinary continence (TUC) immediately after catheter removal was detected in G1, G2a and G2b in 20.0%, 44.0% and 57.1% of cases, respectively. Subsequent objective monitoring of UC recovery from 1 month showed differences (p < 0.001) between the groups in the dynamics of rehabilitation during the year. The improvement in UC over the one-year follow-up period was cumulatively achieved in G1, G2a and G2b in 48.9%, 44.0% and 33.3% of cases, respectively. Total UI persisted in G1 and G2a by month 12 in 22.2% and 8.0% of patients, respectively, and was not detected in G2b. The severity of UI by the end of the follow-up according to the ICIQ-SF data was the most pronounced (p < 0.001) in patients from G1. TUC-patients in all groups from 1 month showed a marked decrease in the severity of obstructive and irritative LUTS and improved quality of life, with no differences (0.157 < p < 0.390) in IPSS-QoL values between groups.Conclusions. The use of modified VUA reconstruction techniques made it possible, compared with the standard one, to achieve high continence rates in patients both immediately after the removal of the urethral catheter and at subsequent follow-up periods, without the formation of severe iatrogenic obstruction. Prostatic urethra-sparing modification is the most effective technique that provided the rehabilitation of UI to a complete and/or social level in all patients within a year after surgery
Determination of the time-dependent reaction coefficient and the heat flux in a nonlinear inverse heat conduction problem
Diffusion processes with reaction generated by a nonlinear source are commonly encountered in practical applications related to ignition, pyrolysis and polymerization. In such processes, determining the intensity of reaction in time is of crucial importance for control and monitoring purposes. Therefore, this paper is devoted to such an identification problem of determining the time-dependent coefficient of a nonlinear heat source together with the unknown heat flux at an inaccessible boundary of a one-dimensional slab from temperature measurements at two sensor locations in the context of nonlinear transient heat conduction. Local existence and uniqueness results for the inverse coefficient problem are proved when the first three derivatives of the nonlinear source term are Lipschitz continuous functions. Furthermore, the conjugate gradient method (CGM) for separately reconstructing the reaction coefficient and the heat flux is developed. The ill-posedness is overcome by using the discrepancy principle to stop the iteration procedure of CGM when the input data is contaminated with noise. Numerical results show that the inverse solutions are accurate and stable
On a factorization of second order elliptic operators and applications
We show that given a nonvanishing particular solution of the equation
(divpgrad+q)u=0 (1) the corresponding differential operator can be factorized
into a product of two first order operators. The factorization allows us to
reduce the equation (1) to a first order equation which in a two-dimensional
case is the Vekua equation of a special form. Under quite general conditions on
the coefficients p and q we obtain an algorithm which allows us to construct in
explicit form the positive formal powers (solutions of the Vekua equation
generalizing the usual powers of the variable z). This result means that under
quite general conditions one can construct an infinite system of exact
solutions of (1) explicitly, and moreover, at least when p and q are real
valued this system will be complete in ker(divpgrad+q) in the sense that any
solution of (1) in a simply connected domain can be represented as an infinite
series of obtained exact solutions which converges uniformly on any compact
subset of . Finally we give a similar factorization of the operator
(divpgrad+q) in a multidimensional case and obtain a natural generalization of
the Vekua equation which is related to second order operators in a similar way
as its two-dimensional prototype does
PHASES High Precision Differential Astrometry of delta Equulei
delta Equulei is among the most well-studied nearby binary star systems.
Results of its observation have been applied to a wide range of fundamental
studies of binary systems and stellar astrophysics. It is widely used to
calibrate and constrain theoretical models of the physics of stars. We report
27 high precision differential astrometry measurements of delta Equulei from
the Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES).
The median size of the minor axes of the uncertainty ellipses for these
measurements is 26 micro-arcseconds. These data are combined with previously
published radial velocity data and other previously published differential
astrometry measurements using other techniques to produce a combined model for
the system orbit. The distance to the system is determined to within a
twentieth of a parsec and the component masses are determined at the level of a
percent. The constraints on masses and distance are limited by the precisions
of the radial velocity data; we outline plans improve this deficiency and
discuss the outlook for further study of this binary.Comment: Accepted by AJ. Complete versions of tables 2-7 now available at
http://stuff.mit.edu/~matthew1/deltaEquTables/ (removed from astroph server
Multi-stage urethroplasy for anterior urethral strictures: objective parameters of long-term efficacy and patient-reported outcomes
Introduction. Multi-stage urethral surgery is used in cases of the most complex urethral strictures. The evaluation of surgical treatment results given by patients is a significant criterion for the efficacy of urethroplasty along with the assessment of urethral patency through instrumental examinations.Objective. To evaluate the long-term efficacy of multistage urethroplasty for complex anterior urethral strictures considering the patients' quality of life and satisfaction with the surgical outcomes.Materials and methods. The study included 73 patients aged 18 â 84 years with anterior urethral strictures who underwent multi-stage urethroplasty in 2010 â 2019. Surgical and functional outcomes of urethroplasty were assessed through general blood and urine tests, physical examination, uroflowmetry, and retrograde urethrography and urethroscopy in case of urinary disorders. Subjective parameters of treatment efficacy were studied using questionnaires: International Prostate Symptom Score (IPSS); Quality of life (QoL); Patient-reported Outcome Measure for Urethral Stricture Surgery (USS-PROM); Patient Global Impression of Improvement (PGI-I).Results. Recurrent urethral stricture was detected in 19 (26,0%) patients with the average follow-up period being 65 months. Independent urination was restored in 71 (97.3%) cases, including repeated interventions. After surgery, there was a significant increase in urinary flow rate parameters (Q max: 8.1 vs 19.1 ml/s, p < 0.0001; Q ave: 5.5 vs 10.7 ml/s; p = 0.0004), decrease in residual urine volume (62.4 vs 18.6 ml, p < 0.0001), decrease in total IPSS score (18.7 vs 5.7 points; p < 0.0001) and QoL index (4.3 vs 1 .8 points, p < 0.0001). A comparative analysis of preoperative and postoperative USS-PROM questionnaire results demonstrated an improvement in indicators assessing LUTS (12.9 vs 3.4 points; p < 0.0001; 3.6 vs 1.7 points; p < 0.0001), and urination-associated quality of life (2.6 vs 0.6 points; pâ< 0.0001) and overall health (EQ-5D index: 0.73 vs 0.91 points; pâ= 0.025; EQ-VAS: 68.0 vs 88.1 points, p = 0.004). Fifty-seven (81.4%) men were âvery satisfiedâ or âsatisfiedâ with the treatment outcomes, while nine (12.9%) respondents noted a moderate effect of residual urinary disorders on the quality of life. Significantly higher satisfaction was observed among cystostomy patients and in cases where repeated interventions were unnecessary.Conclusion. Multi-stage urethroplasty for complex anterior urethral strictures achieves efficacy in 97.3% of cases and is accompanied by high levels of quality of life and patientâs satisfaction during long-term follow-up
PHASES Differential Astrometry and Iodine Cell Radial Velocities of the kappa Pegasi Triple Star System
kappa Pegasi is a well-known, nearby triple star system. It consists of a
``wide'' pair with semi-major axis 235 milli-arcseconds, one component of which
is a single-line spectroscopic binary (semi-major axis 2.5 milli-arcseconds).
Using high-precision differential astrometry and radial velocity observations,
the masses for all three components are determined and the relative
inclinations between the wide and narrow pairs' orbits is found to be 43.8 +/-
3.0 degrees, just over the threshold for the three body Kozai resonance. The
system distance is determined to 34.60 +/- 0.21 parsec, and is consistent with
trigonometric parallax measurements.Comment: Accepted for publication in ApJ, complete versions of tables 2 and 4
can be found at http://stuff.mit.edu/~matthew1/kapPegTables
The Disk Wind in the Young Binaries and the Origin of the Cyclic Activity of Young Stars
We present results of numerical modeling of the cyclic brightness modulation
in the young binary systems with the eccentric orbits and low-mass secondary
components. Brightness variations of the primary is due to the periodical
extinction variations on the line-of-sight caused by the disk wind of the
secondary and a common envelope it produces. A matter distribution in the
envelope has been calculated in the ballistic approach. Calculations showed
that for the young binaries with the elliptic orbits parameters of the
photometric minima (their depth, duration and the shape of light curves) depend
not only on the disk wind parameters and an inclination of the binary orbit to
the line-of-sight but also on the longitude of the periastron. A modulation of
the scattered radiation of the common envelope with a phase of the orbital
period has been investigated in the single scattering approach. It is shown
that an amplitude of the modulation is maximal when the system is seen edge-on
and has also a non-zero value in the binaries observed pole-on. Possible
applications of the theory to the young stellar objects are discussed. In
particular, an attention is payed to a resemblance of the light curves in some
models with light curves of the objects suspected as candidates to FUORs.Comment: 18 pages, 9 figures, accepted by Astronomy Letter
Multi-band analyses of the bright GRB~230812B and the associated SN2023pel
GRB~230812B is a bright and relatively nearby () long gamma-ray
burst that has generated significant interest in the community and therefore
has been subsequently observed over the entire electromagnetic spectrum. We
report over 80 observations in X-ray, ultraviolet, optical, infrared, and
sub-millimeter bands from the GRANDMA (Global Rapid Advanced Network for
Multi-messenger Addicts) network of observatories and from observational
partners. Adding complementary data from the literature, we then derive
essential physical parameters associated with the ejecta and external
properties (i.e. the geometry and environment) and compare with other analyses
of this event (e.g. Srinivasaragavan et al. 2023). We spectroscopically confirm
the presence of an associated supernova, SN2023pel, and we derive a
photospheric expansion velocity of v 17 km . We
analyze the photometric data first using empirical fits of the flux and then
with full Bayesian Inference. We again strongly establish the presence of a
supernova in the data, with an absolute peak r-band magnitude . We find a flux-stretching factor or relative brightness and a time-stretching factor ,
both compared to SN1998bw. Therefore, GRB 230812B appears to have a clear long
GRB-supernova association, as expected in the standard collapsar model.
However, as sometimes found in the afterglow modelling of such long GRBs, our
best fit model favours a very low density environment (). We also find small values for
the jet's core angle and
viewing angle. GRB 230812B/SN2023pel is one of the best characterized
afterglows with a distinctive supernova bump
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