The SAR from our peptide libraries was exploited to design a series of potent deoxybenzoin PTP-1B inhibitors. The introduction of an ortho bromo substituent next to the difluoromethylphosphonate ...warhead gave up to 20-fold increase in potency compared to the desbromo analogues. In addition, these compounds were orally bioavailable and active in the animal models of non-insulin dependent diabetes mellitus (NIDDM).
A series of benzotriazole phenyldifluoromethylphosphonic acids were found to be potent PTP-1B inhibitors. Molecular modeling on the X-ray crystal structure of the lead structure led to the design of ...potent PTP-1B inhibitors that show moderate selectivity against TC-PTP, a very closely related protein tyrosine phosphatase.
The inducible form of the heme-protein prostaglandin G/H synthase (PGHS-2 or COX-2) has been established as a pivotal enzyme in the cascade of events leading to inflammation, hyperalgesia, and ...pyresis and represents a major therapeutic target in inflammatory disease. Accordingly, we have exploited the heme-catalyzed hydroperoxidase activity of recombinant hCOX-2 to generate luminescence in the presence of luminol, or a cyclic naphthalene hydrazide, and the substrate arachidonic acid. Arachidonate-induced luminescence was shown to be an index of real-time catalytic activity and demonstrated the turnover inactivation of the enzyme. Luminol luminescence was proportional to hCOX-2 concentration and gave accurateKmdeterminations for arachidonate. Inhibition of hCOX-2 activity, measured by luminescence, by a variety of selective (for COX-2) and nonselective inhibitors showed rank orders of potency similar to those observed with otherin vitroand whole cell methods using the recombinant protein. The sensitivity of the luminescence assay also allowed determination of inhibitor potency at substrate concentrations belowKm, distinguishing competitive inhibitors such as ibuprofen from time-dependent inhibitors such as DuP-697. Finally the use of higher quantum-yielding luminol analogues allowed measurement of cyclooxygenase activity at extremely low substrate and protein concentrations, enabling a variety of novel assay formats.
Bacteriophage Mu is an ideal system to study DNA transposition. The 70-KDa protein product of the phage early gene A, termed transposase, is absolutely required for transposition. Transposase binds ...specifically at sites located at both ends of the phage genome, termed attL and attR, and at an enhancer-like element at the left end of the genome, called IAS (internal activation sequence). It then nicks at these ends, and nicks a random target DNA sequence in a 5 base pair staggered fashion with 5$ sp prime$ extensions and promotes strand transfer between the Mu ends and the target DNA. The transposase protein can be roughly divided into three domains. The other activities of the protein have not been mapped even at the domain level. To further define the different functional domains of this complex enzyme, a series of insertion mutants at 8 different sites along the transposase protein were constructed using TAB linker mutagenesis. In this study, 1 and 2 TAB linkers were inserted into 8 HpaII sites in the Mu A gene, generating a set of 2 and 4 amino acid insertion mutants. Examination of these mutants for specific DNA-binding activity of transposase to the ends of the phage genome in vitro revealed temperature sensitive proteins. Transpositional activity of the mutant proteins revealed that the mutant proteins, which are temperature sensitive in specific DNA-binding activity, are deficient in transpositional activity.
The 663 amino acid Mu transposase protein is absolutely required for Mu DNA transposition. Mutant proteins were constructed in vitro in order to locate regions of transposase that may be important ...for the catalysis of DNA transposition. Deletions in the A gene, which encodes the transposase, yielded two stable mutant proteins that aid in defining the end-specific DNA-binding domain. Linker insertion mutagenesis at eight sites in the Mu A gene generated two proteins, FF6 and FF14 (resulting from two and four amino acid insertions, respectively, at position 408), which were thermolabile for DNA binding in vitro at 43 degrees C. However, transposition activity in vivo was severely reduced for all mutant proteins at 37 degrees C, except those with insertions at positions 328 and 624. In addition, site-specific mutagenesis was performed to alter tyrosine 414, which is situated in a region that displays amino acid homology to the active sites of a number of nicking/closing enzymes. Tyrosine 414 may reside within an important, yet non-essential, site of transposase, as an aspartate-substituted protein had a drastically reduced frequency of transposition, while the remaining mutants yielded reduced, but substantial, frequencies of microMu transposition in vivo.
Ovarian reserve is one of the most important factors that influences the success of assisted reproductive technology (ART). Recently, the role of anti-müllerian hormone (AMH) in ART has been ...investigated as a marker for the prediction of ovarian response. We aim to examine this relationship within a large Iranian population.BACKGROUNDOvarian reserve is one of the most important factors that influences the success of assisted reproductive technology (ART). Recently, the role of anti-müllerian hormone (AMH) in ART has been investigated as a marker for the prediction of ovarian response. We aim to examine this relationship within a large Iranian population.In this cross-sectional study, we obtained data from 1000 infertile couples who referred to the Research and Clinical Centre of Yazd Infertility Clinic for in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI). Serum AMH levels, oocyte count, numbers of fertilised oocytes, endometrial thickness, and percentage of mature oocytes were measured. The relationship between AMH serum levels and the number and quality of oocytes and embryos in ART cycles was analysed.MATERIALS AND METHODSIn this cross-sectional study, we obtained data from 1000 infertile couples who referred to the Research and Clinical Centre of Yazd Infertility Clinic for in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI). Serum AMH levels, oocyte count, numbers of fertilised oocytes, endometrial thickness, and percentage of mature oocytes were measured. The relationship between AMH serum levels and the number and quality of oocytes and embryos in ART cycles was analysed.In the linear regression model, the log of the variables total dose of gonadotropin, two pronuclei (2PN), log oestradiol, total embryos, duration of stimulation, number of embryos transferred, protocol, and cause of infertility were significant predictors of log AMH.RESULTSIn the linear regression model, the log of the variables total dose of gonadotropin, two pronuclei (2PN), log oestradiol, total embryos, duration of stimulation, number of embryos transferred, protocol, and cause of infertility were significant predictors of log AMH.There appears to be a relationship between serum AMH levels in the early follicular phase and ovarian reserve. Higher serum AMH levels were also associated with shorter ART cycles.CONCLUSIONThere appears to be a relationship between serum AMH levels in the early follicular phase and ovarian reserve. Higher serum AMH levels were also associated with shorter ART cycles.
We compared early and delayed lymphoscintigraphy images using intradermal injection of (99m)Tc-antimony sulfide colloid, which has small particles.
Eighty patients with early-stage breast cancer were ...included into the study. Intradermal injection of (99m)Tc-antimony sulfide colloid was used for sentinel node mapping. After radiotracer injection, 30 min and 20 h later, lymphoscitigraphy images were obtained in lateral and anterior views. After the completion of each image sets, the location of the visible nodes in the axilla was marked on the skin. Two nuclear medicine specialists reviewed the images independently and the number and location of detected nodes were recorded.
At least one hotspot was detected in the axillary region in 78 (97.5%) and 79 (98.75%) patients on the early and delayed images, respectively. No extra-axillary drainage was noted in the patients. The number and location of detected hot spots were the same in 77 patients on both image sets. In one patient the early image did not show any axillary hot spot despite its visualization on the delayed image set and in one patient no hot spot was noted on either images. In one patient an additional axillary hot spot was noted on the delayed image, which was not apparent on the early image.
Our study showed that a delay of up to 20 h in sentinel lymph node biopsy using intradermal injection of (99m)Tc-antimony sulfide colloid does not result in washout of the tracer from the true sentinel node or migration of the radiotracer into second-echelon nodes.
Despite the successful application of sentinel node mapping in breast cancer patients, its use in patients with a history of previous excisional biopsy of the breast tumors is a matter of ...controversy. In the present study we evaluated the accuracy of sentinel node biopsy in this group of patients and compared the results with those in whom the diagnosis of breast cancer was established by core needle biopsy. Eighty patients with early stage breast carcinoma were included into our study. Forty patients had a history of previous excisional biopsy and the remainder 40 had undergone core needle biopsy. Intradermal injections of 99mTc-antimony sulfide colloid as well as patent blue were both used for sentinel node mapping. Sentinel nodes were harvested during surgery with the aid of surgical gamma probe. All patients underwent standard axillary lymph node dissection subsequently. Detection rate was 97.5 per cent for both groups of the study. Number of detected sentinel node during surgery was not significantly different between groups. False negative rate was 0 per cent for both groups of the study. In conclusion sentinel node biopsy is reliable in patients with previous history of excisional biopsy of the breast tumors and has a low false negative rate.
