334 research outputs found
Group theoretic methods applied to Burgers’ equation
AbstractIn this study, the group-theoretic methods for calculating the solution of Burgers’ equation with appropriate boundary- and initial-conditions is presented. The application of a one-parameter group reduces the number of independent variables by one, and consequently the governing partial differential equation with the boundary- and initial-conditions to an ordinary differential equation with the appropriate corresponding conditions. The obtained differential equation is solved analytically and the solution obtained in closed form, for a specific choice of boundary condition
Molecular analysis and application of tissue microarray technology to the histopathological and immunohistochemical analysis of cervical adenocarcinoma
Cervical cancer is the second most common cancer among women worldwide.
Cervical adenocarcinoma accounts for 15-25% of all cervical cancers and the
incidence appears to be increasing. Although some of this increase may be due to
better recognition by pathologists, there is evidence that the incidence of both endocervical
adenocarcinoma and its preinvasive precursor lesion cervical glandular
intraepithelial neoplasia is actually increasing in real terms. In this study, tissue
microarray technology was used to study the morphological features of cervical
adenocarcinoma archival donor blocks, to evaluate the immunoprofile of a large set of
cervical adenocarcinomas with an extended panel of antibodies to compare the profile
of AIS with invasive subtypes of cervical adenocarcinomas. The prevalence of HPV
16&18 in cervical adenocarcinoma cases was assessed to evaluate its relation to
cervical adenocarcinoma.
Using haematoxylin and eosin staining method 273 samples (blocks) were obtained
from 177 biopsies composed of 16 normal cervical biopsies, 139 different patients
with endocervical adenocarcinomas, and 22 patients with second biopsies. Pathology
reports and cervical smear history reports were reviewed. Morphological and
histopathological features of 139 patients with cervical adenocarcinomas revealed that
there were 20 patients with adenocarcinoma-in-situ and 119 with invasive
adenocarcinoma. Sixteen of 119 patients with invasive adenocarcinoma had early
invasive adenocarcinoma which met criteria for FIGO stage IAi carcinoma of the
cervix.
The tissue microarray technique has been demonstrated to be efficient and applicable
to various tumour types, but methodological evaluations are few. A tissue microarray
was constructed using paraffin-embedded, formalin-fixed tissues from 273 samples
(blocks). Two paired 0.6-mm cores were obtained from selected regions of archival
donor blocks and subsequently were arrayed into a recipient paraffin array blocks.
More than 2 areas were taken from some tumours. The novel array blocks and some
whole sections were used for immunohistochemical analysis and H&E staining.
Results revealed that the tissue microarray method yields staining of good quality and
is feasible for histopathological and immunohistochemical studies in cervical
adenocarcinoma. In general, the average staining pattern agreed with the whole
section in each. Analysis of two TMA cores achieved 100% representation for
histopathological type and greater than 97% representation for immunohistochemical
studies.
Tissue array sections were immunostained with 8 antibodies, carcinoembryonic
antigen (CEA), Cytokeratin7 (CK7), Cytokeratin20 (CK20), estrogen receptor (ER),
progesterone receptor (PgR), phosphatase and tensin homolog deleted on
chromosome ten (PTEN), MIB-1 proliferation marker, and p53 suppressor gene
utilizing the "Power Vision" technique for ER only and "Envision" technique for all
other antibodies. Our findings support that all of these 8 antibodies are of potential
biomarkers of a panel of antibodies for diagnosis of cervical adenocarcinomas.
HPV DNA was extracted from paraffin-embedded, formalin-fixed tissues of 161
specimens of 139 patients excluding 22 patients with second samples and 16 normal
cervical tissues. HPV DNA was detected by PCR test using type specific primers
from the E6 gene and E7 gene of HPV type 16 and HPV type 18. Out of a total of 257
cervical biopsies from 139 women with various cervical adenocarcinomas lesions,
HPV DNA was identified in 87 cases (62.6%) in which, HPV16 was positive for 65
(47%) patients and HPV 18 was positive for 41 (29%) patients. Genotyping by RFLP
and PCR revealed that HPV type 16 was the most frequent type of infection
comprising 46 cases (33%), followed by HPV type 18 in 22 cases (16%), and both
HPV typel6 and HPV type 18 in 19 cases (14%). HPV typing in all cases of 16
normal cervical biopsies was negative with both HPV typel6 and HPV type 18. The
findings support that HPV 16, along with HPV 18, may play a possible role in the
pathogenesis of adenocarcinoma of the uterine cervix
Consideraciones taxonómicas sobre algunos taxones egipcios de Capparis y géneros relacionados (Capparaceae) a partir de RAPDs
Taxonomic considerations among and within some Egyptian taxa of Capparis and related genera (Capparaceae) as revealed by RAPD fingerprinting.- This investigation was carried out to assess the taxonomic relationships among eight taxa of the Egyptian members of Capparaceae based on random amplified polymorphic DNA markers, and to compare the results with those obtained from morphological studies. A total of 46 bands were scored for three RAPD primers corresponding to an average of 15.3 bands per primer. The three primers (A03, A07 and A09) revealed eight polymorphic RAPD markers among the studied taxa ranging in size from 200 bp to 1000 bp. Jaccard’s coefficient of similarity varied from 0.28 to 0.84, indicative of high level of genetic variation among the genotypes studied. UPGMA cluster analysis indicated three distinct clusters, one comprised Cleome amblyocarpa and Gynandropsis gynandra, while another included two clusters at 0.74 phenon line; one for Capparis decidua, and the other for Capparis sinaica and all varieties of Capparis spinosa. The four varieties of Capparis spinosa were segregated at 0.84 phenon line. However, one of these varieties was more closely related to Capparis sinaica than to the other three varieties of C. spinosa. The RAPD analysis reported here confirms previous studies based on morphological markers.Consideraciones taxonómicas sobre algunos taxones egipcios de Capparis y géneros relacionados (Capparaceae) a partir de RAPDs.- El objetivo de este trabajo es investigar las relaciones taxonómicas entre ocho taxones pertenecientes a las Capparaceae en base a marcadores de tipo RAPD, y comparar los resultados con los obtenidos previamente en estudios morfológicos. Se han contabilizado un total de 46 bandas para tres pares de cebadores, con una media de 15,3 bandas por cebador. Los tres pares de cebadores (A03, A07 y A09) revelan ocho marcadores polimórficos entre los taxones estudiados, de entre 200 y 1000 pares de bases. El coeficiente de similaridad de Jaccard varía entre 0,28 y 0,84, indicativo de un alto nivel de variación genética entre los genotipos estudiados. El análisis UPGMA muestra tres grupos distintos, el primero comprende Cleome amblyocarpa y Gynandropsis gynandra, mientras que el segundo incluye dos grupos a la altura del valor 0,74 del dendrograma: uno se corresponde con Capparis decidua, y el otro comprende Capparis sinaica y todas las variedades de Capparis spinosa. Las cuatro variedades de C. spinosa se segregan a la altura del valor 0,84 del dendrograma. Sin embargo, una de estas variedades está más relacionada con C. sinaica que con las otras variedades de C. spinosa. El análisis de RAPD confirma los resultados de estudios anteriores basados en caracteres morfológicos
Acute lower respiratory tract infection due to respiratory syncytial virus in a group of Egyptian children under 5 years of age
<p>Abstract</p> <p>Background and aim</p> <p>Respiratory syncytial virus (RSV) is one of the most important causes of acute lower respiratory tract infections (ALRTI) in infants and young children. This study was conducted to describe the epidemiology of ALRTI associated with RSV among children ≤ 5 years old in Egypt.</p> <p>Patients and Methods</p> <p>We enrolled 427 children ≤ 5 years old diagnosed with ALRTI attending the outpatient clinic or Emergency Department (ED) of Children Hospital, Cairo University during a one- year period. Nasopharyngeal aspirates were obtained from the patients, kept on ice and processed within 2 hours of collection. Immunoflourescent assay (IFA) for RSV was performed.</p> <p>Results</p> <p>91 cases (21.3%) had viral etiology with RSV antigens detected in 70 cases (16.4%). The RSV positive cases were significantly younger than other non-RSV cases (mean age 8.2 months versus 14.2 months, p <0.001). RSV cases had significantly higher respiratory rate in the age group between 2-11 months (mean 58.4 versus 52.7/minute, p < 0.001) and no significant difference in the mean respiratory rate in the age group between 12-59 months. More RSV cases required supplemental oxygen (46% versus 23.5%, p < 0.001) with higher rate of hospitalization (37.1% versus 11.2%, p < 0.001) than the non-RSV cases. 97% of RSV cases occurred in winter season (p < 0.001).</p> <p>Conclusion</p> <p>RSV is the most common viral etiology of ALRTI in children below 5 years of age, especially in young infants below 6 months of age. It is more prevalent in winter and tends to cause severe infection.</p
Markers characterizing corneal damage during aging of rat
Aging is a biological phenomenon that involves an increase of oxidative stress associated with gradual degradation of the structure and function of the cornea. Gender differences and subsequent deterioration of cornea is an interesting topic, especially yet few data are available concerning the impact of age, especially on the corneal. One hundred male and female Wistar albino rats ages 3, 6, 18, 24, and 30 months (n=10 equal for male and female) were used. At the time interval, cornea were investigated by light and transmission electron microscopy (TEM), immunohistochemistry of caspase 3 (casp3), glial fibrillar acidic protein(GFAP) and CD45 and flow cytometry of DNA, bcl-2-like protein 4 (BAX), transforming growth factor beta (TGF-β) and Cd45 (lymphocyte common antigen). Light and TEM investigation revealed apparent deterioration of atrophy of corneal epithelium with vesicular vacuolar degeneration, hyalinization of stromal collagen fibrils and swelling and degeneration of the endothelial lining the descemet's membrane. There was apparent loss of keratocytes within corneal stroma. Immunohistochemistry of casp 3 and CD45 were markedly increased manifesting cell damage. GFAP showed apparent reduction of innervation of corneal stroma and endothelium layer. Flow cytometry of DNA, Bax and TGF revealed increased apoptic cell death of cornea of 30M-old rats. We concluded that aging contributed to an apparent increase of cellular damage of different corneal region associated with alterations of cell markers
Myosin-1C augments secretion of von Willebrand factor by linking contractile actomyosin machinery to the plasma membrane.
Blood endothelial cells control the hemostatic and inflammatory response by secreting von Willebrand factor (VWF) and P-selectin from storage organelles called Weibel-Palade bodies (WPB). Actin-associated motor proteins regulate this secretory pathway at multiple points. Prior to fusion, myosin Va forms a complex that anchors WPBs to peripheral actin structures allowing maturation of content. Post-fusion, an actomyosin ring/coat is recruited and compresses the WPB to forcibly expel the largest VWF multimers. Here we provide the first evidence for the involvement of class I myosins during regulated VWF secretion. We show that the unconventional myosin-1C (Myo1c) is recruited post-fusion via its pleckstrin homology domain in an actin-independent process. This provides a link between the actin ring and phosphatidylinositol 4,5-bisphosphate (PIP2) at the membrane of the fused organelle and is necessary to ensure maximal VWF secretion. This is an active process requiring Myo1c ATPase activity as inhibition of class I myosins using the inhibitor Pentachloropseudilin or expression of an ATPase deficient Myo1c rigor mutant perturbs the expulsion of VWF and alters the kinetics of the exocytic actin ring. These data offer a novel insight into the control of an essential physiological process and provide a new way in which it can be regulated
Concentrating on the Impact: Consequence-based Explanations in Recommender Systems
Recommender systems assist users in decision-making, where the presentation
of recommended items and their explanations are critical factors for enhancing
the overall user experience. Although various methods for generating
explanations have been proposed, there is still room for improvement,
particularly for users who lack expertise in a specific item domain. In this
study, we introduce the novel concept of \textit{consequence-based
explanations}, a type of explanation that emphasizes the individual impact of
consuming a recommended item on the user, which makes the effect of following
recommendations clearer. We conducted an online user study to examine our
assumption about the appreciation of consequence-based explanations and their
impacts on different explanation aims in recommender systems. Our findings
highlight the importance of consequence-based explanations, which were
well-received by users and effectively improved user satisfaction in
recommender systems. These results provide valuable insights for designing
engaging explanations that can enhance the overall user experience in
decision-making.Comment: Preprint of the paper to be presented at IntRS'23: Joint Workshop on
Interfaces and Human Decision Making for Recommender Systems, September 18,
2023, Singapore. paper will be published in the workshop proceeding
Purification and characterization of citrate synthase isoenzymes from Pseudomonas aeruginosa
The natural history of primary sclerosing cholangitis in 781 children. A multicenter, international collaboration
There are limited data on the natural history of primary sclerosing cholangitis (PSC) in children. We aimed to describe the disease characteristics and long-term outcomes of pediatric PSC. We retrospectively collected all pediatric PSC cases from 36 participating institutions and conducted a survival analysis from the date of PSC diagnosis to dates of diagnosis of portal hypertensive or biliary complications, cholangiocarcinoma, liver transplantation, or death. We analyzed patients grouped by disease phenotype and laboratory studies at diagnosis to identify objective predictors of long-term outcome. We identified 781 patients, median age 12 years, with 4,277 person-years of follow-up; 33% with autoimmune hepatitis, 76% with inflammatory bowel disease, and 13% with small duct PSC. Portal hypertensive and biliary complications developed in 38% and 25%, respectively, after 10 years of disease. Once these complications developed, median survival with native liver was 2.8 and 3.5 years, respectively. Cholangiocarcinoma occurred in 1%. Overall event-free survival was 70% at 5 years and 53% at 10 years. Patient groups with the most elevated total bilirubin, gamma-glutamyltransferase, and aspartate aminotransferase-to-platelet ratio index at diagnosis had the worst outcomes. In multivariate analysis PSC-inflammatory bowel disease and small duct phenotypes were associated with favorable prognosis (hazard ratios 0.6, 95% confidence interval 0.5-0.9, and 0.7, 95% confidence interval 0.5-0.96, respectively). Age, gender, and autoimmune hepatitis overlap did not impact long-term outcome.
CONCLUSION:
PSC has a chronic, progressive course in children, and nearly half of patients develop an adverse liver outcome after 10 years of disease; elevations in bilirubin, gamma-glutamyltransferase, and aspartate aminotransferase-to-platelet ratio index at diagnosis can identify patients at highest risk; small duct PSC and PSC-inflammatory bowel disease are more favorable disease phenotypes
Molecular cloning and over-expression of the glyoxylate bypass operon from Escherichia coli ML308
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