Co-Targeting ErbB Receptors and the PI3K/AKT Axis in Androgen-Independent Taxane-Sensitive and Taxane-Resistant Human Prostate Cancer Cells.

Using two representative models of androgen-independent prostate cancer (PCa), PC3 and DU145, and their respective paclitaxel- and docetaxel-resistant derivatives, we explored the anti-tumor activity of targeting the ErbB receptors and AKT using small-molecule kinase inhibitors. These cells manifest varying degrees of neuroendocrine differentiation characteristics and differ in their expression of functional PTEN. Although the specific downstream signaling events post the ErbB receptor and AKT co-targeting varied between the PC3- and DU145-lineage cells, synergistic anti-proliferative and enhanced pro-apoptotic responses occurred across the wild-type and the taxane-resistant cells, independent of their basal AKT activation state, their degree of paclitaxel- or docetaxel-resistance, or whether this resistance was mediated by the ATP Binding Cassette transport proteins.

Detection of an enzyme isomechanism by means of the kinetics of covalent inhibition.

Turnover of substrates by many enzymes involves free enzyme forms that differ from the stable form of the enzyme in the absence of substrate. These enzyme species, known as isoforms, have, in general, different physical and chemical properties than the native enzymes. They usually occur only in small concentrations under steady state turnover conditions and thus are difficult to detect.

Demand for Cysticercosis Vaccine: Lessons and Insights From the Pig Production and Trading Nodes of the Uganda Pig Value Chain.

cysticercosis disease remains a key challenge to the pig sector in low- and middle-income countries in sub-Saharan Africa, Latin America and South East Asia, resulting in both economic losses and public health impacts. The World Health Organization has ranked it first on the global scale of foodborne parasites. A One Health approach has been recommended for reduction of infection pressure and eradication in the longer term.

Hematological prediction study of peritonitis following laparotomy in goats.

Surgical trauma to the abdominal wall and peritoneum during celiotomy is expected to cause postoperative inflammation. However, complications after abdominal surgery are hardly detected in the early stage. Hematological analysis of blood has been considered beneficial in disease diagnosis and prognosis.

Specificity of extended O-aryloxycarbonyl hydroxamates as inhibitors of a class C β-lactamase.

Class C β-lactamases have previously been shown to be efficiently inactivated by O-aryloxycarbonyl hydroxamates. O-Phenoxycarbonyl-N-benzyloxycarbonylhydroxylamine (1) and O-phenoxycarbonyl-N-(R)-[(4-amino-4-carboxy-1-butyl)oxycarbonyl]hydroxylamine (2), for example, were found to be effective inactivators. The present paper describes a structure-activity study of these molecules to better define the important structural elements for high inhibitory activity.

Kinetic Evidence for a Second Ligand Binding Site on Streptococcus pneumoniae Penicillin-Binding Protein 2x.

High molecular mass penicillin-binding proteins (PBPs, DD-peptidases) of class B, such as Streptococcus pneumoniae PBP2x, catalyze the cross-linking of peptidoglycan in bacterial cell wall biosynthesis and are thus important antibiotic targets. Despite their importance in this regard, structure-function studies of ligands of these enzymes have been impeded by the absence of useful substrates. In vitro, these enzymes do not catalyze peptide hydrolysis or aminolysis, their in vivo reaction, but some, such as PBP2x, do catalyze these reactions of certain thioesters such as PhCHCONHCHCOSCH(D-Me)CO (2).

Coexistence of Antiphospholipid Syndrome and Heparin-Induced Thrombocytopenia in a Patient with Recurrent Venous Thromboembolism.

Heparin-induced thrombocytopenia (HIT) is a prothrombotic adverse drug reaction in which heparin forms complexes with platelet factor 4 forming neoantigens that are recognized by autoantibodies. Antiphospholipid syndrome (APS) is similar to HIT in that it is mediated by autoantibodies that are also prothrombotic. We present a case of rare coexistence of antiphospholipid antibody syndrome and heparin-induced thrombocytopenia.

Specificity and mechanism of mandelamide hydrolase catalysis.

The best-studied amidase signature (AS) enzyme is probably fatty acid amide hydrolase (FAAH). Closely related to FAAH is mandelamide hydrolase (MAH), whose substrate specificity and mechanism of catalysis are described in this paper. First, we developed a convenient chromogenic substrate, 4-nitrophenylacetamide, for MAH.

Penicillin acylase and O-aryloxycarbonyl hydroxamates: Two acyl-enzymes, one leading to hydrolysis, the other to inactivation.

O-Aryloxycarbonyl hydroxamates have previously been shown to covalently inactivate serine/amine amidohydrolases such as class C β-lactamases and a N-terminal hydrolase, the proteasome. We report here reactions between O-aryloxycarbonyl hydroxamates and another N-terminal hydrolase, penicillin acylase. O-Aryloxycarbonyl hydroxamates, as non-symmetric carbonates, have two different leaving groups attached to the reactive central carbonyl group.

Targeting IκB Kinase β/NF-κB Signaling in Human Prostate Cancer by a Novel IκB Kinase β Inhibitor CmpdA.

NF-κB plays an important role in many types of cancer, including prostate cancer, but the role of the upstream kinase of NF-κB, IKKβ, in prostate cancer has neither been fully documented nor are there any effective IKKβ inhibitors used in clinical settings. Here, we have shown that IKKβ activity is mediated by multiple kinases including IKKα in human prostate cancer cell lines that express activated IKKβ. IHC analysis (IHC) of human prostate cancer tissue microarrays (TMA) demonstrates that phosphorylation of IKKα/β within its activation loop gradually increases in low to higher stage tumors as compared with normal tissue.

An extremely indolent T-cell leukemia: an 18-year follow-up.

T-cell prolymphocytic leukemia (T-PLL) is a rare malignancy that comprises about 2% of all mature lymphoid neoplasms. Patients usually present with prominent peripheral blood lymphocytosis, splenomegaly, hepatomegaly, lymphadenopathy, B symptoms, and occasionally with skin lesions.¹ The disease follows an aggressive clinical course with rapid progression and typically has a median survival of less than 1 year.

A New Covalent Inhibitor of Class C β-Lactamases Reveals Extended Active Site Specificity.

O-Aryloxycarbonyl hydroxamates have previously been shown to efficiently inactivate class C β-lactamases by cross-linking serine and lysine residues in the active site. A new analogue of these inhibitors, D-(R)-O-(phenoxycarbonyl)-N-[(4-amino-4-carboxy-1-butyl)oxycarbonyl]hydroxylamine, designed to inactivate certain low-molecular mass dd-peptidases, has now been synthesized. Although the new molecule was found to be only a poor inactivator of the latter enzymes, it proved, unexpectedly, to be a very effective inactivator (ki = 3.

Interactions of "bora-penicilloates" with serine β-lactamases and DD-peptidases.

Specific boronic acids are generally powerful tetrahedral intermediate/transition state analogue inhibitors of serine amidohydrolases. This group of enzymes includes bacterial β-lactamases and DD-peptidases where there has been considerable development of boronic acid inhibitors. This paper describes the synthesis, determination of the inhibitory activity, and analysis of the results from two α-(2-thiazolidinyl) boronic acids that are closer analogues of particular tetrahedral intermediates involved in β-lactamase and DD-peptidase catalysis than those previously described.

Reflex anuria: a rare cause of acute kidney injury.

Background: Acute Kidney Injury results from pre renal, post renal or intrinsic renal causes. Reflex anuria is a very rare cause of renal impairment which happens due to irritation or trauma to one kidney or ureter, or severely painful stimuli to other nearby organs.

Case Presentation: Here we present a case of acute kidney injury secondary to reflex anuria in a patient who underwent extensive gynecological surgery along with ureteral manipulation which recovered spontaneously.

Dual substrate specificity of Bacillus subtilis PBP4a.

Bacterial dd-peptidases are the targets of the β-lactam antibiotics. The sharp increase in bacterial resistance toward these antibiotics in recent years has stimulated the search for non-β-lactam alternatives. The substrates of dd-peptidases are elements of peptidoglycan from bacterial cell walls.

Inhibition of DD-peptidases by a specific trifluoroketone: crystal structure of a complex with the Actinomadura R39 DD-peptidase.

Inhibitors of bacterial DD-peptidases represent potential antibiotics. In the search for alternatives to β-lactams, we have investigated a series of compounds designed to generate transition state analogue structures upon reaction with DD-peptidases. The compounds contain a combination of a peptidoglycan-mimetic specificity handle and a warhead capable of delivering a tetrahedral anion to the enzyme active site.

Crossover inhibition as an indicator of convergent evolution of enzyme mechanisms: a β-lactamase and a N-terminal nucleophile hydrolase.

O-Aryloxycarbonyl hydroxamates and 1,3,4-oxathiazol-2-ones have been identified as covalent inhibitors of β-lactamases and proteasomes, respectively. The products of these inhibition reactions are remarkably similar, involving carbonyl cross-linking of the active sites. We have cross-checked these inhibitors, showing that the former inhibit proteasomes and the latter β-lactamases, to form the same inactive carbonyl adducts.

Comparative evaluation of a new lactation curve model for pasture-based Holstein-Friesian dairy cows.

Fourteen lactation models were fitted to average and individual cow lactation data from pasture-based dairy systems in the Australian states of Victoria and Tasmania. The models included a new "log-quadratic" model, and a major objective was to evaluate and compare the performance of this model with the other models. Nine empirical and 5 mechanistic models were first fitted to average test-day milk yield of Holstein-Friesian dairy cows using the nonlinear procedure in SAS.

Telomere and microtubule targeting in treatment-sensitive and treatment-resistant human prostate cancer cells.

Modulating telomere dynamics may be a useful strategy for targeting prostate cancer cells, because they generally have short telomeres. Because a plateau has been reached in the development of taxane-based treatments for prostate cancer, this study was undertaken to evaluate the relative efficacy of targeting telomeres and microtubules in taxane-sensitive, taxane-resistant, androgen-sensitive, and androgen-insensitive prostate cancer cells. Paclitaxel- and docetaxel-resistant DU145 cells were developed and their underlying adaptive responses were evaluated.

Substrate specificity of low-molecular mass bacterial DD-peptidases.

The bacterial DD-peptidases or penicillin-binding proteins (PBPs) catalyze the formation and regulation of cross-links in peptidoglycan biosynthesis. They are classified into two groups, the high-molecular mass (HMM) and low-molecular mass (LMM) enzymes. The latter group, which is subdivided into classes A-C (LMMA, -B, and -C, respectively), is believed to catalyze DD-carboxypeptidase and endopeptidase reactions in vivo.

Kinetics of reactions of the Actinomadura R39 DD-peptidase with specific substrates.

The Actinomadura R39 DD-peptidase catalyzes the hydrolysis and aminolysis of a number of small peptides and depsipeptides. Details of its substrate specificity and the nature of its in vivo substrate are not, however, well understood. This paper describes the interactions of the R39 enzyme with two peptidoglycan-mimetic substrates 3-(D-cysteinyl)propanoyl-D-alanyl-D-alanine and 3-(D-cysteinyl)propanoyl-D-alanyl-D-thiolactate.

Early infection during burn-induced inflammatory response results in increased mortality and p38-mediated neutrophil dysfunction.

Following burn injury, the host is susceptible to bacterial infections normally cleared by healthy patients. We hypothesized that during the systemic immune response that follows scald injury, the host's altered immune status increases infection susceptibility. Using a murine model of scald injury under inhaled anesthesia followed by intraperitoneal infection, we observed increased neutrophil numbers and function at postburn day (PBD) 1 compared with sham-burned and PBD4 mice.

T cells are potent early mediators of the host response to sepsis.

The complex immune response associated with sepsis results in a high rate of morbidity and mortality, despite substantial basic science and clinical advances. Most of the research has centered on the innate immune response, in contrast to the adaptive immune system. This is likely caused by the perceived time frame during which these two responses are understood to mediate their effects.