90 research outputs found
Placental transfer of antibiotics administered to the mother: a review
No full textBackground: The purpose of antibiotic treatment in pregnant women is to treat the mother and/or the fetus since it is known that antibiotics administered to the mother cross the placenta and reach the fetus. A comparison of the drug concentration in maternal and fetal plasma gives an indication of the exposure of the fetus to the maternally administered antibiotics. Aim: The aim of this study was to review the literature pertaining to the placental transfer of antibiotics in mail and to classify the antibiotics according to the type of transfer involved. A table has been developed for use by physicians that lists the name of the antibiotic, the drug concentration in the cord and material plasma at delivery and the type of transfer involved. Methods: An initial medline search was performed with the key words "placental transfer of antibiotics" with the limit of "human". A second medline search was performed with the key words "placental transfer of..." followed by the class names of the antibiotic such as penicillins, cephalosporins, aminoglycosides, tetracyclines and macrolides. The bibliographic search on the placental transfer of antibiotics covered the period up to July 2005. Results: 3 types of placental transfers were identified. A few antibiotics cross the placenta rapidly and equilibrate in the maternal and cord plasma; this type of transfer is termed "complete" and include the antibiotics ampicillin, methicillin, cefmenoxime and cefotiam. Antibiotics which show incomplete transfer to the placenta where concentrations are lower in the cord than material plasma are said to have "incomplete" transfer and these include azlocillin, dicloxacillin, piperacillin, sulbenicillin, cefoxitin, amikacin, gentamicin, kanatnycin, streptomycin, fosfornycin, thiamphenicol, griseofulvin, vancomycin and colistimethate. Ceftizoxime is the only antibiotic so far known whose concentrations are higher in the cord than material plasma. This type of transfer is called "exceeding" transfer. Conclusion: All examined antibiotics cross the human placenta including those with a molecular weight greater than 1000 kDa such as vancomycin and colistimethate but there are 3 distinct types of placental transfer: complete, incomplete and exceeding and most antibiotics exhibit incomplete transfer
Inhibition of human liver and duodenum sulfotransferases by drugs and dietary chemicals: a review of the literature
No full textSulfotransferase catalyzes the transfer of sulfate, donated by 3'-phosphoadenosine-5'-phosphosulfate, to an acceptor substrate that may be a hydroxy group or an amine group. Man is exposed daily to drugs and dietary chemicals that can inhibit sulfotransferase activity The aim of this study was to review the literature concerning the inhibition of sulfotransferases by drugs and dietary chemicals in the human liver and duodenum. The IC50 value of mefenamic acid for human liver phenol sulfotransferase (SULT1A1) was 0.02 muM and for human liver catechol sulfotransferase (SULT1A3) 76 muM with a SULT1A3/SULT1A1 ratio for the IC50 of 3,800. Mefenamic acid is therefore a potent and selective inhibitor of human liver SULT1A1. The IC50 values of mefenamic acid for the sulfation rates of (-)-salbutamol and (-)-apomorphine were 4 orders of magnitude greater in the human duodenum than in the liver. Salicylic acid inhibited the sulfation of (-)-apomorphine in human liver with an IC50 of 54 muM but did not inhibit the sulfation of (-)-apomorphine in human duodenum. Quercetin, a flavonoid present in edible fruit, vegetable and wine, was a potent inhibitor of human liver SULT1A1 and estrogen sulfotransferase (EST) activities and the sulfation of resveratrol. Quercetin inhibited the sulfation of dopamine, (-)-salbutamol, minoxidil and paracetamol and the IC50 values were I - 2 orders of magnitude greater in human duodenum than in the liver. In conclusion, mefenamic acid, salicylic acid and quercetin inhibit SULT1A1 whereas SULT1A3 is relatively resistant to the inhibition by these compounds. Under particular circumstances, human duodenum sulfotransferase is more resistant than liver sulfotransferase to the inhibition by mefenamic acid, salicylic acid and quercetin
Methylation of quercetin and fisetin, flavonoids widely distributed in edible vegetables, fruits and wine, by human liver
No full textThe aim of this investigation was to study the methylation of quercetin and fisetin, 2 chemically related flavonoids, in human liver and to this purpose, an assay, was set-up to measure the rates of quercetin and fisetin methylation in human liver. The methylation rates (pmol/min/mg) Of quercetin and fisetin were measured in 10 liver samples and the mean +/- SD and the median were 170 +/- 30 and 177 (quercetin) and 183 15 and 178 (fisetin). The rates of quercetin and fisetin methylation were not different (p = 0.283). The fold of variation among samples as 2 (quercetin) and 1.3 (fisetin). Methytransferase towards quercetin and fisetin followed Michaelis-Menten kinetics, and the K-m values were 2.6 +/- 0.3 (quercetin) and 8,6 +/- 0.7 muM (fisetin. p = 0.009) and the V-max values were 187 +/- 20 (quercetin) and 276 +/- 33 pmol/min/mg (fisetin, p = 0.009). Two. 4 and 8 mul of red Chianti wine added to the incubation mixture reduced the rate of quercetin methylation to 75 +/- 4%, 65 +/- 9% and 59 +/- 9%, respectively, and that of fisetin methylation to 62 +/- 3%, 51 +/- 3% and 44 +/- 4%. respectively. In conclusion. quercetin and fisetin are methylated in human liver and their rates of methylation have a limited variation among subjects
Curcumin is a potent inhibitor of phenol sulfotransferase (SULT1A1) in human liver and extrahepatic tissues
No full textAbstract
1. Curcumin has anti-carcinogen effects and is under clinical evaluation as a potential colon cancer chemopreventive agent. The first aim was to see whether curcumin inhibited phenol sulfotransferase (SULT1A1) and, if so, to study the variability of the IC(50) of curcumin for SULT1A1 in 50 human liver samples. For comparative purposes, the inhibition of catechol sulfotransferase (SULT1A3) in five human liver specimens was studied. The second aim was to measure the IC(50) of curcumin against SULT1A1 in five samples of human duodenum, colon, kidney and lung. 2. Curcumin was a potent inhibitor of SULT1A1 in human liver; the mean +/- SD and median of IC(50) were 14.1 +/- 7.3 nM and 12.8 nM, respectively. The IC(50) ranged from 6.2 to 30.6 nM between the 5th and 95th percentiles and the fold of variation was 4.9. The distribution of IC(50) was positively skewed (skewness 1.2) and deviated from normality (p = 0.0004). 3. Curcumin inhibited human SULT1A3, and the inhibition was studied in five liver specimens with an IC(50) of 4324 +/- 1026 nM. This inhibition was greater than the IC(50) of curcumin for SULT1A1 (p < 0.0001). 4. In the extrahepatic tissues, the IC(50) of curcumin for SULT1A1 was 25.9 +/- 4.8 nM (duodenum), 25.4 +/- 6.8 nM (colon), 23.4 +/- 2.2 nM (kidney) and 25.6 +/- 5.6 nM (lung). Inhibition in these tissues is greater than that of curcumin for SULT1A1 in human liver (p < 0.0001). 5. In conclusion, curcumin is a potent inhibitor of SULT1A1 in human liver, duodenum, colon, kidney and lung. The IC(50) of curcumin for SULT1A1 varied 4.9-fold in human liver. The comparison of the present data with those of the literature revealed that the IC(50) of curcumin in the liver and extrahepatic tissues is one order of magnitude lower that the peak serum concentration of curcumin after therapeutic doses of 4 g to humans
An Axiomatic Design Approach for Customer Satisfaction through a Lean Start-up Framework
No full textAbstractValue generation and customer satisfaction are the primary goals for those companies which want to be successful and profitable on the global market. Achieving these objectives is key for a middle-long term successful business model. Missing them may eventually lead to the company's failure, and also it might be a very difficult task to accomplish. Due to its strategic importance, the overall business model, along with the products and services to be delivered, should be assessed iteratively, defining their importance in respect with the customer needs and expectations. This control check is often experience-based rather than rationally guided, even in large and structured organizations. This paper proposes a novel approach to systemically build a customer development model, to verify the agreement between what is offered and the customer needs. The proposed customer model is built through the Axiomatic Design method, together with other tools that are properly tuned for this specific application
Groups whose prime graph on class sizes has a cut vertex
No full text[EN] Let G be a finite group, and let Delta(G) be the prime graph built on the set of conjugacy class sizes of G: this is the simple undirected graph whose vertices are the prime numbers dividing some conjugacy class size of G, two vertices p and q being adjacent if and only if pq divides some conjugacy class size of G. In the present paper, we classify the finite groups G for which Delta(G) has a cut vertex.The research of the first and second authors is partially supported by the Italian PRIN 2015TW9LSR_006 "Group Theory and Applications" and by INdAM-GNSAGA.
The research of the third author is supported by the Spanish Ministerio de Ciencia e Innovacion PID2019-103854GB-I00 partly with FEDER funds.
The fourth author acknowledges the support of the Spanish Ministerio de Ciencia, Innovacion y Universidades proyecto PGC2018-096872-B-I00, the grant ACIF/2016/170 from Generalitat Valenciana, and the prize Borses Ferran Sunyer i Balaguer 2019.Dolfi, S.; Pacifici, E.; Sanus, L.; Sotomayor, V. (2021). Groups whose prime graph on class sizes has a cut vertex. Israel Journal of Mathematics. 244(2):775-805. https://doi.org/10.1007/s11856-021-2193-2S7758052442D. Bubboloni, S. Dolfi, M. A. Iranmanesh and C. E. Praeger, On bipartite divisor graphs for group conjugacy class sizes, Journal of Pure and Applied Algebra 213 (2009), 1722–1734.C. Casolo and S. Dolfi, The diameter of a conjugacy class graph of finite groups, Bulletin of the London Mathematical Society 28 (1996), 141–148.C. Casolo and S. Dolfi, Products of primes in conjugacy class sizes and irreducible character degrees, Israel Journal of Mathematics 174 (2009), 403–418.C. Casolo, S. Dolfi, E. Pacifici and L. Sanus, Groups whose prime graph on conjugacy class sizes has few complete vertices, Journal of Algebra 364 (2012), 1–12.C. Casolo, S. Dolfi, E. Pacifici and L. Sanus, Incomplete vertices in the prime graph on conjugacy class sizes of finite groups, Journal of Algebra 376 (2013), 46–57.S. Dolfi, Arithmetical conditions on the length of the conjugacy classes of a finite group, Journal of Algebra 174 (1995), 753–771.S. Dolfi, On independent sets in the class graph of a finite group, Journal of Algebra 303 (2006), 216–224.S. Dolfi, E. Pacifici, L. Sanus and V. Sotomayor, The prime graph on class sizes of a finite group has a bipartite complement, Journal of Algebra 542 (2020), 35–42.I. M. Isaacs, Coprime group actions fixing all nonlinear irreducible characters, Canadian Journal of Mathematics 41 (1989), 68–82.I. M. Isaacs, Finite Group Theory, Graduate Studies in mathematics, Vol. 92, American Mathematical Society, Providence, RI, 2008.M. L. Lewis and Q. Meng, Solvable groups whose prime divisor character degree graphs are 1-connected, Monatshefte für Mathematik 190 (2019), 541–548.O. Manz and T. R. Wolf, Representations of Solvable Groups, London Mathematical Society Lecture Note Series, Vol. 185, Cambridge University Press, Cambridge, 1993.J. M. Riedl, Character degrees, class sizes and normal subgroups of a certain class of p-groups, Journal of Algebra 218 (1999), 190–215
Bounding the number of vertices in the degree graph of a finite group
No full textLet G be a finite group, and let cd(G) denote the set of degrees of the irreducible complex characters of G. The degree graph Δ(G) of G is defined as the simple undirected graph whose vertex set V(G) consists of the prime divisors of the numbers in cd(G), two distinct vertices p and q being adjacent if and only if pq divides some number in cd(G). In this note, we provide an upper bound on the size of V(G) in terms of the clique number ω(G) (i.e., the maximum size of a subset of V(G) inducing a complete subgraph) of Δ(G). Namely, we show that |V(G)|≤max2ω(G)+1,3ω(G)−4. Examples are given in order to show that the bound is best possible. This completes the analysis carried out in [1] where the solvable case was treated, extends the results in [3,4,9], and answers a question posed by the first author and H.P. Tong-Viet in [4]
7-OH-flavone is sulfated in the human liver and duodenum, whereas 5-OH-flavone and 3-OH-flavone are potent inhibitors of SULT1A1 activity and 7-OH-flavone sulfation rate. Xenobiotica. 2002 Jul;32(7):563-71
No full text1. The aim of this investigation was to see whether 7-OH- ̄avone, 5-OH- ̄avone and
3-OH- ̄avone, which are present in edible vegetables, fruit and wine, are substrates or
inhibitors of human liver and duodenum sulfotransferase.
2. An assay was set up to study the sulfation of 7-OH- ̄avone, and using this assay, it
was observed that 7-OH- ̄avone was sulfated and the rate of sulfation (mean SD) was
324 87 pmol min¡1 mg¡1 (liver) and 584 164 pmol min¡1mg¡1 (duodenum;
p < 0:0001).
3. 7-OH- ̄avone sulfotransferase followed Michaelis±Menten kinetics and the Km
(mean SD) was 0.2 0.04 mM (liver) and 1.1 0.3 mM (duodenum; p ˆ 0:008). Vmax
(mean SD) was 392 134 pmol min¡1 mg¡1 (liver) and 815 233 pmolmin¡1 mg¡1
(duodenum; p ˆ 0:016).
4. 5-OH- ̄avone and 3-OH- ̄avone were not sulfated and were inhibitors of human
liver and duodenum SULT1A1 activity and 7-OH- ̄avone sulfation rate.
5. The IC50 of 5-OH- ̄avone for SULT1A1 was 0.3 0.06 mM (liver) and 0.3 0.1 mM
(duodenum; n.s.) and those of 3-OH- ̄avone were 1.0 0.1 mM (liver) and 1.6 0.03 mM
(duodenum; p ˆ 0:0006).
6. There was inhibition of 7-OH- ̄avone sulfation rate by 5-OH- ̄avone and 3-OH-
̄avone. The IC50 of 5-OH- ̄avone for the sulfation rate of 7-OH- ̄avone was 3.5 0.5 mM
(liver) and 69 18 mM (duodenum; p < 0:0001) and for 3-OH- ̄avone it was 18 3.4 mM
(liver) and 213 47 mM (duodenum; p < 0:0001).
7. The position of the hydroxy group confers to the molecules of OH- ̄avones the
quality of substrate or inhibitor of sulfotransferase
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