34 research outputs found
Nieinwazyjna diagnostyka prenatalna trisomii 21,18 i 13 z wykorzystaniem wolnego pozakomórkowego DNA płodu
Trisomy 21, 18 and 13 are the most common trisomies diagnosed in newborns. Screening methods consist of ultrasound and maternal serum markers. High risk for fetal aneuploidies is an indication for routine karyotyping, which requires collection of fetal tissue through amniocentesis or chorionic villous sampling. They are invasive procedures and carry a potential risk of miscarriage. The discovery of cell free fetal DNA (cffDNA) in maternal blood offered new opportunities for noninvasive prenatal diagnosis. The fraction of cell-free fetal DNA in total pool of cell-free DNA in maternal plasma is very low, therefore the analysis of cffDNA is very challenging. The introduction of massive parallel sequencing has enabled the application of noninvasive prenatal testing in the clinical practice and a variety of recent studies have proven its high efficacy in diagnosing common aneuploidies.Trisomie chromosomów 21, 18 i 13 należą do najczęściej diagnozowanych aberracji chromosomowych u noworodków. Obecnie w celu oceny ryzyka ich wystąpienia wykonuje się badanie ultrasonograficzne oraz testy biochemiczne. Stwierdzenie na podstawie testów przesiewowych wysokiego ryzyka trisomii u płodu jest wskazaniem do oznaczenia kariotypu klasyczną metodą cytogenetyczną, która niesie za sobą potrzebę pobrania materiału genetycznego płodu. Badania inwazyjne (amniopunkcja, biopsja trofoblastu) obarczone są ryzykiem straty ciąży. Wykrycie obecności wolnego pozakomórkowego DNA płodu (cffDNA – cell free fetal DNA) we krwi matki zapoczątkowało szereg badań nad możliwościami jego wykorzystania w diagnostyce prenatalnej. cffDNA stanowi jednak tylko niewielką część całkowitej puli wolnego DNA we krwi matki, dlatego jego analiza jest trudna. Wprowadzenie metody masywnego równoległego sekwencjonowania umożliwiło zastosowanie nieinwazyjnych testów w praktyce klinicznej, a prowadzone w ostatnich latach liczne badania dowiodły skuteczności metody w diagnostyce prenatalnej trzech najczęściej występujących trisomii
An Exploratory Survey of Self-Reported Joint Pain Among College Students
Topics in Exercise Science and Kinesiology Volume 4: Issue 1, Article 13, 2023. Prior research has shown that college students are a unique subset of our global population that commonly experience stresses and strains to their musculoskeletal system as they complete their traditional coursework. Most of this population is viewed as healthy since their joints and skeletal systems have yet to be subjected to the levels of wear and tear of their elder constituents. However, there are still individuals within this population that often report experiencing some level of joint pain or discomfort that would not fall underneath the classic diagnoses of arthritis or other severe joint-related pathologies. The purpose of this descriptive study was to examine joint pain in non-clinical college students and some of the potential contributions to that pain. An email was sent to the entire current student population at a southeastern university in the United States inviting them to complete an online questionnaire about joint pain. Prior to its distribution, a pilot version of the questionnaire was distributed and tested to ensure readability and to establish content validity. The final version of the questionnaire was distributed twice during the fall 2021 semester. From the total number of students who may have received the email invitation (n = 18,985), 211 students completed the survey for a response rate of 1.11%. Of the 116 respondents who had never seen a healthcare professional for a joint injury or joint surgery, 72 reported current joint pain (62%). Thirty participants (47.6%) reported that the duration of their pain has lasted longer than three months. Participants reported cervical pain (76%), lumbar spine pain (84.8%), knee pain (65.1%), and hip or pelvis pain (76.2%) as the most frequent joints being affected. While typically considered healthy, college students are experiencing joint health-related pain and discomfort. Due to lack of past and current research on joint health in college students, the results of this exploratory study may begin to shed light on the need to implement and fund more proactive methods to best address this emerging issue
Multiplex Ligation-dependent Probe Amplification (MLPA) – new possibilities of prenatal diagnosis
Multiplex Ligation-dependent Probe Amplification (MLPA) is a relatively new method of molecular diagnosis. It enables a relative quantitative assessment of up to 50 different PCR amplicons in one reaction by the use of a very small amount of examined DNA. Nowadays MLPA is becoming a very helpful tool in prenatal diagnosis and is widely used for the detection of aneuploidies, familial single gene disorders, common microdeletion syndromes, sub-telomeric alterations and identification of marker chromosomes in fetuses. This review demonstrates possible applications of MLPA in prenatal diagnosis
Limitations on the principle of stationary phase when it is applied to tunneling analysis
Using a recently developed procedure - multiple wave packet decomposition -
here we study the phase time formulation for tunneling/reflecting particles
colliding with a potential barrier. To partially overcome the analytical
difficulties which frequently arise when the stationary phase method is
employed for deriving phase (tunneling) time expressions, we present a
theoretical exercise involving a symmetrical collision between two identical
wave packets and an one-dimensional rectangular potential barrier. Summing the
amplitudes of the reflected and transmitted waves - using a method we call
multiple peak decomposition - is shown to allow reconstruction of the scattered
wave packets in a way which allows the stationary phase principle to be
recovered.Comment: 17 pages, 2 figure
Measurement of Superluminal optical tunneling times in double-barrier photonic bandgaps
Tunneling of optical pulses at 1.5 micron wavelength through double-barrier
periodic fiber Bragg gratings is experimentally investigated. Tunneling time
measurements as a function of barrier distance show that, far from the
resonances of the structure, the transit time is paradoxically short, implying
Superluminal propagation, and almost independent of the distance between the
barriers. These results are in agreement with theoretical predictions based on
phase time analysis and also provide an experimental evidence, in the optical
context, of the analogous phenomenon expected in Quantum Mechanics for
non-resonant superluminal tunneling of particles across two successive
potential barriers. [Attention is called, in particular, to our last Figure].
PACS nos.: 42.50.Wm, 03.65.Xp, 42.70.Qs, 03.50.De, 03.65.-w, 73.40.GkComment: LaTeX file (8 pages), plus 5 figure
Small Corrections to the Tunneling Phase Time Formulation
After reexamining the above barrier diffusion problem where we notice that
the wave packet collision implies the existence of {\em multiple} reflected and
transmitted wave packets, we analyze the way of obtaining phase times for
tunneling/reflecting particles in a particular colliding configuration where
the idea of multiple peak decomposition is recovered. To partially overcome the
analytical incongruities which frequently rise up when the stationary phase
method is adopted for computing the (tunneling) phase time expressions, we
present a theoretical exercise involving a symmetrical collision between two
identical wave packets and a unidimensional squared potential barrier where the
scattered wave packets can be recomposed by summing the amplitudes of
simultaneously reflected and transmitted wave components so that the conditions
for applying the stationary phase principle are totally recovered. Lessons
concerning the use of the stationary phase method are drawn.Comment: 14 pages, 3 figure
The Exact Correspondence between Phase Times and Dwell Times in a Symmetrical Quantum Tunneling Configuration
The general and explicit relation between the phase time and the dwell time
for quantum tunneling or scattering is investigated. Considering a symmetrical
collision of two identical wave packets with an one-dimensional barrier, here
we demonstrate that these two distinct transit time definitions give connected
results where, however, the phase time (group delay) accurately describes the
exact position of the scattered particles. The analytical difficulties that
arise when the stationary phase method is employed for obtaining phase
(traversal) times are all overcome. Multiple wave packet decomposition allows
us to recover the exact position of the reflected and transmitted waves in
terms of the phase time, which, in addition to the exact relation between the
phase time and the dwell time, leads to right interpretation for both of them.Comment: 11 pages, 2 figure
Nieinwazyjna diagnostyka prenatalna najczęstszych aneuploidii na podstawie płodowego DNA we krwi matki – doniesienie wstępne
Objectives: The aim of the study was to present initial results of non-invasive prenatal diagnosis of common aneuploidies of chromosomes 21, 18 and 13 based on cell-free fetal DNA in maternal serum in high-risk patients, and to compare the results with routine karyotyping. Material and methods: Before the invasive procedure, 10 ml of peripheral blood from 10 patients was collected to isolate cell-free fetal DNA and to perform a non-invasive fetal trisomy test (NIFTY provided by Beijing Genomics Institute, BGI, Shenzen, China). Results: Three out of 10 samples showed an abnormal karyotype in traditional karyotyping. There were 9 conclusive NIFTY results. NIFTY detected 1 out of 2 trisomies 18. The quantity of cell-free fetal DNA in maternal plasma in the second probe with trisomy 18 was unsatisfactory for a conclusive NIFTY result. In 1 case traditional karyotyping revealed mosaicism impossible to detect with NIFTY.Cel pracy: Wstępne przedstawienie wyników wykorzystania płodowego DNA z krwi matki w nieinwazyjnej diagnostyce prenatalnej aneuploidii chromosomów 21, 18 i 13 u pacjentek wysokiego ryzyka aberracji chromosomowych u płodu oraz ich porównanie z wynikami klasycznego badania cytogenetycznego. Materiał i metoda: Od dziesięciu ciężarnych pacjentek przed wykonaniem badania inwazyjnego pobrano 10 ml krwi obwodowej celem izolacji pozakomórkowego DNA płodu (cffDNA – cell free fetal DNA) i przeprowadzenia testu NIFTY (Non-Invasive Fetal Trisomy Test; Beijing Genomics Institute, BGI, Shenzen, China). Wyniki: W trzech z dziesięciu próbek w badaniu cytogenetycznym stwierdzono nieprawidłowy kariotyp płodu. Na podstawie płodowego DNA z dziewięciu próbek osocza za pomocą testu NIFTY udało się określić ryzyko aneuploidii u płodu. Wysokie ryzyko aneuploidii prawidłowo oceniono w jednym z dwóch przypadków trisomii chromosomu 18. W drugiej probce podejrzewano wysokie ryzyko trisomii chromosomu 18, ale ilość cffDNA była zbyt mała, aby wynik spełniał standardy producenta. Wykryty w badaniu cytogenetycznym kariotyp mozaikowy z założenia nie mógł zostać wykryty metodą nieinwazyjną. Wnioski: Płodowe DNA z krwi matki może służyć do wykrywania najczęstszych aneuploidii u płodu. Test mógłby posłużyć jako badanie przesiewowe II rzutu, prowadząc do zmniejszenia liczby pacjentek poddawanych badaniu inwazyjnemu
Frequency of Chlamydia trachomatis in Ureaplasma-positive healthy women attending their first prenatal visit in a community hospital in Sapporo, Japan
<p>Abstract</p> <p>Background</p> <p>Although <it>Chlamydia trachomatis </it>is the most commonly reported pathogen that causes urogenital infection such as urethritis or cervicitis, <it>Ureaplasma parvum </it>and <it>Ureaplasma urealyticum</it>, which are commensals in the genital tract, have also now been recognized as contributors to urogenital infection. However, whether the presence of either <it>U. parvum </it>or <it>U. urealyticum </it>is related to that of <it>C. trachomatis </it>in the urogenital tract remains unknown. We therefore attempted to estimate by PCR the prevalence of <it>C. trachomatis, U. parvum </it>and <it>U. urealyticum </it>in endocervical samples obtained from healthy women attending their first prenatal visit in Sapporo, Japan.</p> <p>Methods</p> <p>The samples were taken from 303 apparently healthy women, and the extracted DNAs (<it>n </it>= 280) were used for PCR detection targeting <it>C. trachomatis, U. parvum </it>and <it>U. urealyticum</it>. Statistical analysis of the data was performed by Fisher's exact test.</p> <p>Results</p> <p>PCR detection revealed that the prevalence of <it>C. trachomatis, U. parvum </it>and <it>U. urealyticum </it>was 14.3% (40/280), 41.7% (117/280) and 8.9% (25/280), respectively. <it>C. trachomatis ompA </it>genotype D was most frequently identified. Surprisingly, either <it>C. trachomatis </it>or <it>Ureaplasma </it>spp. was detected in almost half of the healthy women. Mixed infection of <it>C. trachomatis </it>with either <it>U. parvum </it>or <it>U. urealyticum </it>was also observed in 9.2% (26/280) of the women. There was a significant association between <it>C. trachomatis </it>and either <it>U. parvum </it>(<it>p </it>= 0.023) or <it>Ureaplasma </it>total (<it>p </it>= 0.013), but not <it>U. urealyticum </it>(<it>p </it>= 0.275).</p> <p>Conclusion</p> <p>This study demonstrated that the presence of <it>Ureaplasma </it>had a significant effect on the presence of <it>C. trachomatis </it>in the genital tract of healthy women, suggesting that mixed infection is an important factor in bacterial pathogenesis in the genital tract.</p