Plasma levels of alpha-1-antichymotrypsin are elevated in patients with chronic heart failure, but are of limited prognostic value.

BACKGROUND: There is increasing interest in utilising novel markers of cardiovascular disease risk in patients with chronic heart failure (HF). Recently, it was shown that alpha-1-antichymotrypsin (ACT), an acute-phase protein and major inhibitor of cathpesin G, plays a role in the pathophysiology of HF and may serve as a marker for myocardial distress. OBJECTIVE: To assess whether ACT is independently associated with long-term mortality in chronic HF patients. METHODS: ACT plasma levels were categorised into quartiles. Survival times were analysed using Kaplan-Meier curves and Cox proportional hazards regression, without and with correction for clinically relevant risk factors, including sex, age, duration of HF, kidney function (MDRD), ischaemic HF aetiology and NT-proBNP. RESULTS: Twenty healthy individuals and 224 patients (mean age 71 years, 72 % male, median HF duration 1.6 years) with chronic HF were included. In total, 159 (71 %) patients died. The median survival time was 5.3 (95 % CI 4.5-6.1) years. ACT was significantly elevated in patients (median 433 µg/ml, IQR 279-680) in comparison with controls (median 214 µg/ml, IQR 166-271; p < 0.001). Cox regression analysis demonstrated that ACT was not independently related to long-term mortality in chronic HF patients (crude HR = 1.03, 95 % CI 0.75-1.41, p = 0.871; adjusted HR = 1.12, 95 % CI 0.78-1.60, p = 0.552), which was confirmed by Kaplan-Meier curves. CONCLUSION: ACT levels are elevated in chronic HF patients, but no independent association with long-term mortality can be established.

Peripartum cardiomyopathy: the need for a national database.

Peripartum cardiomyopathy (PPCM) is a rare and life-threatening disease that affects young women in the last month of pregnancy or within 5 months of delivery. It is a form of dilated cardiomyopathy with left-sided systolic dysfunction. The incidence rate in the Western world is estimated to be 1:3000. Symptoms of PPCM vary greatly and may be obscured by common physiological aspects of pregnancy. Therefore, the incidence rate might be higher. Echocardiography or MRI can confirm or rule out PPCM. Unfortunately, there is no specific risk factor profile available. The clinical course varies from complete recovery to deterioration of cardiac function. Patients with PPCM, especially those whose ventricular function has not returned to normal, are advised against further pregnancy. Recently, more disease-specific therapeutic strategies have been developed with promising results for prolactin blockade by bromocriptine. Increasing awareness for PPCM among general practitioners, gynaecologists and cardiologists may help to diagnose patients efficiently in order to start adequate treatment. A national registry is warranted to identify risk factor profiles and to optimise treatment strategies.

Real-world impact of anti-HER2 therapy-related cardiotoxicity in patients with advanced HER2-positive breast cancer.

BACKGROUND: Anti-HER2 therapy-related cardiotoxicity is well described in the context of clinical trials, particularly in the setting of early stage disease, but there is more limited data in advanced breast cancer and in the real world setting. MATERIAL AND METHODS: A prospectively-maintained registry database with 312 consecutive patients diagnosed with HER2 positive advanced breast cancer in Australia was analysed. RESULTS: 287 patients (92%) received anti-HER2 therapy, 17 (6%) experienced anti-HER2 therapy-related cardiotoxicity. Patients who experienced cardiotoxicity were more likely to have ≥2 risk factors for cardiotoxicity (OR 3.9 95% CI 1.4-11.3 p = 0.01). A prior diagnosis of cardiovascular disease was significantly associated with cardiotoxicity (OR 7.1 95% CI 1.3-39.5). Cardiotoxicity resolved on imaging in 65% of patients; there was no association between severity and resolution. 11 patients (65%) received cardiologist input. Of the patients who developed cardiotoxicity, 12 patients (71%) received further anti-HER2 therapy in the first- or second-line setting without recurrent cardiotoxicity. DISCUSSION AND CONCLUSION: Therapy-related cardiotoxicity is an uncommon complication of anti-HER2 therapy in the real world setting. Cardiac toxicity resolved in the majority of affected patients, and further anti-HER2 therapy was administered without recurrence of cardiac issues. Our data suggests anti-HER2 therapy can be safely given in routine care, even in patients with risk factors for toxicity.

Identification of the cystic fibrosis gene: cloning and characterization of complementary DNA.

Overlapping complementary DNA clones were isolated from epithelial cell libraries with a genomic DNA segment containing a portion of the putative cystic fibrosis (CF) locus, which is on chromosome 7. Transcripts, approximately 6500 nucleotides in size, were detectable in the tissues affected in patients with CF. The predicted protein consists of two similar motifs, each with (i) a domain having properties consistent with membrane association and (ii) a domain believed to be involved in ATP (adenosine triphosphate) binding. A deletion of three base pairs that results in the omission of a phenylalanine residue at the center of the first predicted nucleotide-binding domain was detected in CF patients.

Expression cloning and signaling properties of the rat glucagon receptor.

Glucagon and the glucagon receptor are a primary source of control over blood glucose concentrations and are especially important to studies of diabetes in which the loss of control over blood glucose concentrations clinically defines the disease. A complementary DNA clone for the glucagon receptor was isolated by an expression cloning strategy, and the receptor protein was expressed in several kidney cell lines. The cloned receptor bound glucagon and caused an increase in the intracellular concentration of adenosine 3', 5'-monophosphate (cAMP). The cloned glucagon receptor also transduced a signal that led to an increased concentration of intracellular calcium. The glucagon receptor is similar to the calcitonin and parathyroid hormone receptors. It can transduce signals leading to the accumulation of two different second messengers, cAMP and calcium.

The formation of an aligned 1D nanostructure on annealed Fe/ZnSe bilayers.

A highly aligned one-dimensional (1D) nanostructure was realized at the surface of Fe/ZnSe bilayers grown on GaAs(001) substrates through thermal annealing. These 1D nano-grooves were found to align along the [110] direction resulting in bent reflection high energy electron diffraction (RHEED) patterns when the sample was rotated relative to the e-beam. A model based on Ewald construction is presented to explain the unusual RHEED observation. The formation mechanism of this 1D nanostructure is possibly related to the minimization of surface energy, together with an Fe-Se exchange interaction and Fe-induced decomposition of several top ZnSe atomic layers during thermal annealing.

Lens-specific promoter activity of a mouse gamma-crystallin gene.

Crystallins are the major water-soluble proteins in vertebrate eye lenses. These lens-specific proteins are encoded by several gene families, and their expression is differentially regulated during lens cell differentiation. Here we show that a cloned mouse gamma-crystallin promoter is active in lens explants derived from 14-day-old chicken embryos but inactive in a variety of cells of non-lens origin. We also show that sequences required for proper utilization of this promoter are contained between nucleotide positions -392 and +47 relative to the transcription initiation site; deletion of sequences from positions -392 to -171 completely abolishes promoter activity. Since chickens do not have gamma-crystallin genes, the expression of a mouse gamma-crystallin promoter in chicken lens cells suggests that different classes of crystallin genes may be regulated by common lens tissue-specific mechanism(s) independent of species.

Targeting BCL-2 to enhance vulnerability to therapy in estrogen receptor-positive breast cancer.

The last three decades have seen significant progress in our understanding of the role of the pro-survival protein BCL-2 and its family members in apoptosis and cancer. BCL-2 and other pro-survival family members including Mcl-1 and BCL-XL have been shown to have a key role in keeping pro-apoptotic 'effector' proteins BAK and BAX in check. They also neutralize a group of 'sensor' proteins (such as BIM), which are triggered by cytotoxic stimuli such as chemotherapy. BCL-2 proteins therefore have a central role as guardians against apoptosis, helping cancer cells to evade cell death. More recently, an increasing number of BH3 mimetics, which bind and neutralize BCL-2 and/or its pro-survival relatives, have been developed. The utility of targeting BCL-2 in hematological malignancies has become evident in early-phase studies, with remarkable clinical responses seen in heavily pretreated patients. As BCL-2 is overexpressed in ~75% of breast cancer, there has been growing interest in determining whether this new class of drug could show similar promise in breast cancer. This review summarizes our current understanding of the role of BCL-2 and its family members in mammary gland development and breast cancer, recent progress in the development of new BH3 mimetics as well as their potential for targeting estrogen receptor-positive breast cancer.

Polymer Capsules for Plaque-Targeted In Vivo Delivery.

Targeted polymer capsules can selectively bind to unstable plaques in mice after intravenous injection. Different formulations of the capsules are explored with a synthetic/biopolymer hybrid capsule showing the best stability and small-molecule drug retention. The synthetic polymer is composed of pH-sensitive blocks (PDPA), low-binding blocks (PEG), and click-groups for postfunctionalization with targeting peptides specific to plaques.

Stable expression of human alpha-2,6-sialyltransferase in Chinese hamster ovary cells: functional consequences for human erythropoietin expression and bioactivity.

Hamster cell lines are common hosts for recombinant protein production, e.g. erythropoietin (Epo). Terminal sialylation of native human proteins is characteristically in both alpha-2,3 and alpha-2,6 linkage to galactose at the termini of N-linked oligosaccharides but only in alpha-2,3 linkage in recombinant proteins expressed in hamster cells which do not express alpha-2, 6-sialyltransferase (ST6GalI) (EC 2.4.99.1). This difference could alter the bioactivity of certain recombinant proteins. Chinese hamster ovary (CHO) cells stably transfected with human ST6GalI cDNA linked to the hamster metallothionein II promoter expressed highly inducible authentic ST6GalI activity. Untransfected CHO cells and CHO cells stably expressing ST6GalI cDNA when transfected with a human Epo cDNA expression cassette secreted immunoreactive Epo. Human Epo from singly transfected Pro-5 CHO cells induced significant reticulocytosis (7.00+/-1.58%; mean+/-S.D. % reticulocytes; control conditioned medium 3.04+/-1.29%; P<0.0024), whereas Epo from Pro-5 cells coexpressing ST6GalI elicited a more modest reticulocytosis (4.62+/-1.02%). Thus for recombinant human Epo, engineering CHO cells to express ST6GalI activity does not enhance Epo bioactivity in vivo in mice. The availability of CHO cells that express high levels of ST6GalI activity now enables systematic studies to determine the functional requirement for this form of sialylation in recombinant human proteins.

Functional expression of human and mouse plasma phospholipid transfer protein: effect of recombinant and plasma PLTP on HDL subspecies.

The molecular cloning of mouse plasma phospholipid transfer protein (PLTP) and the eukaryotic cell expression of complementary DNA for mouse and human PLTP are described. Mouse PLTP was found to share 83% amino acid sequence identity with human PLTP. PLTP was produced in baby hamster kidney cells. Conditioned medium from BHK cells expressing PLTP possessed both phospholipid transfer activity and high density lipoprotein (HDL) conversion activity. PLTP mRNA was detected in all 16 human tissues examined by Northern blot analysis with ovary, thymus, and placenta having the highest levels. PLTP mRNA was also examined in eight mouse tissues with the highest PLTP mRNA levels found in the lung, brain, and heart. The effect of purified human plasma-derived PLTP and human recombinant PLTP (rPLTP) on the two human plasma HDL subspecies Lp(A-I) and Lp(A-I/A-II) was evaluated. Plasma PLTP or rPLTP converted the two distinct size subspecies of Lp(A-I) into a larger species, an intermediate species, and a smaller species. Lp(A-I/A-II) particles containing multiple size subspecies were significantly altered by incubation with either plasma or rPLTP with the largest but less prominent subspecies becoming the predominant one, and the smallest subspecies increasing in concentration. Thus, PLTP promoted the conversion of both Lp(A-I) and Lp(A-I/A-II) to populations of larger and smaller particles. Also, both human PLTP and mouse rPLTP were able to convert human or mouse HDL into larger and smaller particles. These observations suggest that PLTP may play a key role in extracellular phospholipid transport and modulation of HDL particles.

Tissue factor overexpression in rat arterial neointima models thrombosis and progression of advanced atherosclerosis.

BACKGROUND: Tissue factor located in the atherosclerotic plaque might cause the clinically significant thrombotic events associated with end-stage disease. It might also affect intimal area by increasing matrix accumulation and stimulating smooth muscle cell (SMC) migration and proliferation. To test this hypothesis, we overexpressed tissue factor in a rat model of the human fibrous plaque. METHODS AND RESULTS: A neointima was generated by seeding tissue factor-overexpressing rat SMCs onto the luminal surface of a balloon-injured syngeneic rat carotid artery. The cells attached and expressed tissue factor over the long term. Mural thrombus accumulation was present at 4 and 7 days and increased neointimal SMC numbers and area by 2-fold at 2 and 4 weeks. Tissue factor overexpression accelerated reendothelialization compared with controls at 2 weeks and 1 month. Tissue factor-overexpressing SMCs exhibited increased migration both in vitro and in vivo. The increased migration by tissue factor-overexpressing SMCs in vitro was not dependent on activation of the coagulation cascade and could be blocked by an inhibitor of tissue factor. CONCLUSIONS: These results suggest that tissue factor plays a direct role in neointimal development by coagulation-dependent and -independent pathways.

Increased expression of mRNA for the long form of the leptin receptor in the hypothalamus is associated with leptin hypersensitivity and fasting.

The responsiveness of the hypothalamus to the inhibitory effects of leptin on food intake and body weight is influenced by multiple factors, including deficiency of either leptin or leptin receptors (Ob-R). To investigate whether altered expression of Ob-R in the hypothalamus could potentially contribute to altered leptin sensitivity, we performed in situ hybridization with riboprobes that detected either mRNAs encoding both the long (Ob-Rb) and short (Ob-Ra) splice variants or mRNA encoding only Ob-Rb. In the arcuate nucleus, mRNA encoding Ob-Rb, the predominant signaling form of the receptor, was 2.3 times greater in obese db/db and ob/ob mice than in lean +/ob controls (P < 0.01). In ob/ob mice, systemic administration of leptin reduced Ob-Rb mRNA content of the arcuate nucleus by 30% compared with saline-treated, pair-fed controls (P < 0.05). A 48-h fast increased Ob-Rb mRNA levels in the arcuate nucleus of normal and neuropeptide Y (NPY)-knockout mice (P < 0.01), although the effect was greater in the NPY-knockout mice (400 vs. 247%, P < 0.05). In addition, Ob-Rb mRNA hybridization was elevated by 40% in the arcuate nucleus (P < 0.05) and by 75% in the ventromedial nucleus (P < 0.05) of rats fasted 48 h. The results suggest that expression of Ob-Rb mRNA in the hypothalamus is sensitive to genetic and physiological interventions that alter circulating leptin levels, and that overexpression of Ob-Rb in the hypothalamus may contribute to increased leptin sensitivity.

Multifunctional Thrombin-Activatable Polymer Capsules for Specific Targeting to Activated Platelets.

Smart poly(2-oxazoline) (POx)-based multifunctional polymer capsules that specifically target glycoprotein (GP) IIb/IIIa on the surface of activated platelets are degraded by the serine protease thrombin and release the urokinase plasminogen activator loaded into the polymer capsules, only in the area of acute thrombosis.

The human glucagon receptor encoding gene: structure, cDNA sequence and chromosomal localization.

Characterization of the human glucagon-receptor-encoding gene (GGR) should provide a greater understanding of blood glucose regulation and may reveal a genetic basis for the pathogenesis of diabetes. A cDNA encoding a complete functional human glucagon receptor (GGR) was isolated from a liver cDNA library by a combination of polymerase chain reaction and colony hybridization. The cDNA encodes a receptor protein with 80% identity to rat GGR that binds [125I]glucagon and transduces a signal leading to increases in the concentration of intracellular cyclic adenosine 3',5'-monophosphate. Southern blot analysis of human DNA reveals a hybridization pattern consistent with a single GGR locus. In situ hybridization to metaphase chromosome preparations maps the GGR locus to chromosome 17q25. Analysis of the genomic sequence shows that the coding region spans over 5.5 kb and is interrupted by 12 introns.

Congener derivatives and conjugates of histamine: synthesis and tissue and receptor selectivity of the derivatives.

A series of 19 congener derivatives and conjugates of histamine was synthesized and tested to determine whether the ligands would alter the conventional histamine activity in various tissues. The derivatives, which contained either branched or unbranched aliphatic groups, aromatic amide groups, or dipeptides, exhibited affinities for histamine type 1 and/or type 2 receptors that were widely different from the progenitor. The p-trifluoromethyl derivative of histamine with an intermediate chain length of four methylenes (compound 13) was the most potent lymphocytes H2 receptor agonist but was inactive on guinea pig myocardium H2 receptors. The deletion of a single methylene chain (compound 12) from this compound resulted in total loss of its H2 activity on lymphocytes and its H1 activity on aorta. Compound 12 became an exclusive H1 agonist on lymphocytes H1 receptors. The dipeptide conjugate (compound 17) and the aliphatic congener derivative (compound 18), both with four methylenes, retained some of the activity on guinea pig myocardium H2 receptors, but lost their activity on lymphocytes H2 receptors. Therefore, histamine can be modified at sites that are at a distance from the imidazole moiety, resulting in tissue selective histamine receptor agonists.

Preemptive treatment for the prevention of cytomegalovirus disease: in lung and heart transplant recipients.

BACKGROUND: Rapid quantifiable diagnostic techniques for the diagnosis of cytomegalovirus (CMV) infection may predict patients at risk of CMV pneumonitis and allow preemptive antiviral treatment. METHODS: Using CMV antigenemia as a prospective surveillance technique for CMV infection, we compared the outcome of preemptive treatment (PT) with ganciclovir, 10 mg/kg/day for 21 days directed by "high levels" of CMV antigenemia (PT group, n= 19), with the outcome in a group of historical controls (n=18) treated with ganciclovir when CMV illness occurred. Greater than 50 antigen-positive cells per 2 x 10(5) polymorphonuclear leukocytes was considered to be high-level antigenemia. RESULTS: Nine of the 18 controls developed high-level CMV antigenemia at a median of 33 days (range: 13-65 days) and 5 of the 9 developed CMV disease. Ten of the 19 PT group had high levels of CMV antigenemia detected at a median of 47 days (range: 20-63 days) and were given ganciclovir; none developed CMV disease. There was a significantly lower incidence of CMV disease in the PT group in comparison to controls (0 of 19 vs. 5 of 18: P=0.019). CONCLUSION: We have reduced the incidence of CMV disease using preemptive treatment, and because of a 100% negative predictive value, we omitted unnecessary antiviral prophylaxis for many at-risk patients.

The four stereoisomers of a high potency congener of isoproterenol. Biological activity and the relationship between the native and the chemically inserted asymmetric carbon.

The RR isomer of a para-trifluoromethyl anilide congener of isoproterenol (PTFMA) had an affinity eighty and one hundred times higher than (-)isoproterenol for the beta receptor of turkey erythrocytes and of S49 cells respectively. This affinity was also much higher than that of +/- hydroxybenzyl isoproterenol (HBI) tested in the same experiments. The chemically inserted asymmetric carbon seemed to be as important as the native asymmetric carbon of the catecholamines in determining the binding affinity. Thus the RS and SR isomers demonstrated similar affinities in the turkey erythrocyte membranes as well as in the S49 lysed cells. The RR isomer had the lowest Kact in activation of adenylate cyclase in both beta receptor systems. The three most potent PTFMA isomers showed a Kact/Kd ratio which was higher than that of (-)isoproterenol or (+/-)HBI. It is therefore possible that the large substituent on the amino group in PTFMA, which greatly increases the binding affinity, is not as efficient in receptor activation. Yet the RR isomer had a Kact considerably lower than that of (-)isoproterenol in both of the beta receptor systems. The type of beta receptor of the turkey erythrocyte could be distinguished from that of the S49 cells by comparing the relative order of affinities of the RS and SR isomers and also by comparing (+/-)HBI with (-)isoproterenol. A labeled RR isomer of PTFMA could become most useful as an agonist ligand for beta receptors because of its very high binding affinity for both beta 1 and beta 2 receptors.

Idiopathic pulmonary fibrosis and cyclosporine: a lesson from single-lung transplantation.

Idiopathic pulmonary fibrosis (IPF) has a poor prognosis and therapeutic options are limited with a 5-year survival of less than 50%. This report includes a case of histologically confirmed IPF in a patient whose native lung showed objective improvement as measured by high-resolution CT while he was receiving cyclosporine-based immunosuppressive therapy after single-lung transplantation.