Structure optimization of a leukotriene D4 antagonist by combinatorial chemistry in solution

Structure optimization of the leukotriene D4 antagonist Ro24-5913 was attempted by combinatorial chemistry. Three segments in its N-succinyl-3-(2-thiazolylethenyl)anilide skeleton, designated as A, B, and C coincided with the thiazolyl, aniline, and N-acyl moieties, respectively, and were selected for variations in a synthesis involving the sequences A + B-->AB and AB + C-->ABC to furnish the library (10A 7B 10C) containing 700 compounds. Lead candidates were identified by the LTD4-induced muscle-contraction assay. Assays of the C-partition 10(10A 7B C) of the set led to a subset of C elements associated with significant bioactivities, ic = {C1, C2, C3}, from which the preferred element C1 was selected. Incorporating this selection into the synthesis of the first reduced set gave the partition 7(10A B C1) whose assay revealed the set iB = {B1, B6} and hence the preferred B element B1. The second reduced set, 10(A B1 C1) incorporating the selected C1 and B1 moieties, revealed iA = {A1, A3, A4, A6, A7, A8, A9} In the resulting combinatiorial product iA x iB x iC, comprising 42 elements, A1 B1 C1 appears on top of the list. Thus, 4-[[3-[2-[4-(2,2-dimethyl ethyl)cyclobutyl-2-thiazolyl]ethenyl] phenyl]amino]-2,2-diethyl-4-oxobutanoic acid (Ro24-5913) was confirmed as the structure with the highest bioactivity. Analogues obtained by replacement of the cyclobutyl group in Ro24-5913 with 4-fluorophenyl and t-butyl were the runners-up. Of these, the former exhibited bioactivity comparable to that of Ro24-5913.

Treatment of acute exacerbation of chronic cor pulmonale with fei xin ling syrup

30 cases of chronic cor pulmonale with acute exacerbation were treated with Fei Xin Ling Syrup compared with 30 similar cases treated with Western modern drugs as controls. The Chinese herbal drug modality was found to be superior to the administration of modern drugs in the control group in overall therapeutic effects, with regard to the symptoms of coughing, tachypnea, phlegm production, edema, and the prevention of heart and respiratory failure. Rheological studies in part of the patients also indicated that the Chinese herbal prescription improved the blood circulation.

Characterization of a second human cyclin A that is highly expressed in testis and in several leukemic cell lines

In this study, we isolated and characterized a human cyclin A-like gene that we named cyclin A1. Cyclin A1 has 48% identity with human cyclin A and is more related to the recently cloned murine cyclin A1 (84% identity). The human cyclin A1 is specifically expressed in testis and brain among all of the normal tissues that we studied by Northern blot analysis; in addition, it is expressed in several myeloid leukemia cell lines, including ML-1, U937, NB4, KG-1, and THP1. A sensitive reverse transcription-PCR-Southern blot method also detected low-level expression of this gene in many other hematopoietic and nonhematopoietic cell lines. The expression of cyclin A1 mRNA is differentiation- and cell cycle-regulated in the ML-1 cells. We raised polyclonal antibodies against a glutathione S-transferase-cyclin A1 fusion protein produced in Escherichia coli. In immunoblot analyses, the antibodies recognized the Mr 65,000 cyclin A1 protein in ML-1 cells. The anti-cyclin A1 also immunoprecipitated the Mr 65,000 cyclin A1, along with the Mr 33,000 cyclin-dependent kinase (CDK) 2 and other proteins at Mr 39,000, 42,000, 45,000, 95,000, and 110,000. In an in vitro kinase assay, the CDK2-cyclin A1 complex precipitated by anti-cyclin A1 showed kinase activities against histone H1. In a yeast two-hybrid assay, cyclin A1 can bind to CDK2 but not to CDC2, CDK4, and CDK5. We mapped the human cyclin A1 gene to chromosome 13q12.3-q13, approximately 1000 kb from the sequence-tagged site marker WI-3374.

OVAREX MAb-B43.13:IFN-gamma could improve the ovarian tumor cell sensitivity to CA125-specific allogenic cytotoxic T cells

Various immunological parameters were studied in 100 ovarian cancer patients injected with the OVAREX therapeutic vaccine (the functional component of which is anti-CA125 MAb-B43.13) to explain the serendipitous observation of prolonged survival after such treatment. In addition to CA125-specific humoral and cellular responses, interferon-gamma (IFN-gamma) was also found to be induced in those patients receiving the vaccine. In vitro studies indicated that the expression of MHC I, MHC II, and ICAM I in ovarian tumor cells were upregulated in response to IFN-gamma. Such tumor cells were also found to be more sensitive to CA125-specific cytotoxic T cells compared to cells that were not incubated with IFN-gamma.

Redistribution of platelet membrane glycoprotein IV and release of intracellular alpha-granule thrombospondin in patients with chronic myelogenous leukemia

The redistribution of platelet membrane glycoprotein IV (GPIV) and the release of intracellular alpha-granule thrombospondin (TSP) were examined and the inhibition of beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) in patients with chronic myelogenous leukemia (CML) was observed and quantitation of beta-TG and PF4 in sera was conducted. GPIV in inactive platelet from CML was 36080 +/- 17010 molecules/platelet as compared with 13190 +/- 4810 from the controls (P < 0.01). No abnormality was found in the distribution of platelet membrane GPIb and GPIIb/IIIa (P > 0.05). The GPIV redistribution on active platelet membrane induced thrombin (IU/ml) from CML and healthy donors was 44320 +/- 32310 and 22800 +/- 12700 molecules/platelet respectively (P < 0.01). The difference in the release of intracellular alpha-granule TSP between CML and the control group was not found (P > 0.05). There was no direct correlation between GPIV expression and TSP binding after platelet activation. The high levels of beta-TG and PF4 in sera inhibited release of intracellular alpha-granule TSP in vitro. These results indicate that the abnormality of platelet membrane GPIV is a common marker in CML, therefore the specific increase of platelet GPIV in patients with CML may be a useful tool for the diagnosis and monitoring of the platelet dysfunction. The release of internal TSP pools is hindered by either beta-TG or PF4 in sera.

DNA based biosensors

Compared to advances in enzyme sensors, immunosensors, and microbial biosensors, relatively little work exists on DNA based biosensors. Here we review the DNA based biosensors that rely on nucleic acid hybridization. Major types DNA biosensors--electrochemical, optical, acoustic, and piezoelectric--are introduced and compared. The specificity and response characteristics of DNA biosensors are discussed. Overall, a promising future is foreseen for the DNA based sensor technology.

Structural analysis and characterization of tissue and hormonal responsive expression of the avian bone sialoprotein (BSP) gene

Bone sialoprotein (BSP) is an extracellular matrix protein that has a highly restricted expression to mineralized skeletal tissues. The chicken bone sialoprotein-encoding gene (bsp) was isolated and shown to contain two less exons than similar mammalian genes, with the absence of an untranslated 5' exon and the fusion of the first two exons that encode the signal peptide and amino terminal end of the mature BSP peptide. Primer extension analysis showed one strong transcriptional start point (tsp) in mRNA prepared from embryonic bone. Comparison of the avian bsp promoter sequence to those of other genes expressed in vertebrate skeletal tissues, identified the presence of homeobox protein binding sequence motifs for engrailed (en-1) and Msx 2 (Hox 8.1), and two collagen type II gene silencer elements. Two TATA sequences one at -21 bp and the second at -172 bp to the tsp were identified. For the first TATA element no CCAAT sequence was observed at an appropriate cis position however two Sp1 sequences (GGGCGG) were identified at -66 and -85 bp. A CCAAT element was seen in an appropriate cis position in relationship to the second upstream TATA, but transient expression analysis in embryonic chicken calvaria osteoblasts using two separate promoter/reporter constructs (+24 to -1244 bp or -121 to -1244 bp), confirmed that only the proximal TATA and Sp1 elements were functional. The +24 to -1244 bp promoter sequence demonstrated 33.6, 13.2, and 3.2 fold activity above base line respectively, within cells prepared from embryonic chicken calvaria bone, cephalic sterna, a cartilage that undergoes mineralization and caudal sterna, a cartilage that does not mineralize during embryogenesis. Only base line activity was observed within cells prepared from embryonic dermal fibroblasts a non-skeletal tissue, which does not express BSP. These same cells demonstrated comparable steady state mRNA levels, corroborating that this segment of promoter DNA had tissue specific activity. A series of nested deletions from the 5' end of the -1244 construct demonstrated that a portion of the tissue specific regulation was controlled by the presence of a silencer element(s) between -1244 and -620 bp since deletion of this segment of DNA resulted in a 6 fold increase in the promoter activity in dermal skin fibroblasts. The -1244-(+)24 nt promoter construct was shown to be stimulated by dexamethasome approximately 1.5 fold over control, inhibited by 1,25(OH)2D3 approximately 60% of control and was strongly stimulated approximately 5.0 fold by parathyroid hormone (PTH) in embryonic calvaria osteoblasts. These data define the proximal promoter of the avian bsp gene and identify several potential regulatory elements that have been observed in the promoters of other genes expressed in skeletal tissues. These elements imparted both tissue and hormone specific promoter activity to bsp expression within skeletal cells.

Prostaglandin F2 alpha induces cardiac myocyte hypertrophy in vitro and cardiac growth in vivo

Several prostaglandins [prostaglandin (PG) A2, -B2, -D2, -E2, -F2 alpha, and -I2 and carbaprostacyclin] and the thromboxane analogue U-46619 were analyzed for the ability to induce hypertrophy of rat neonatal cardiac ventricular myocytes. Myocyte hypertrophy was induced specifically by PGF2 alpha. Myocytes exposed to this prostanoid in culture increased in size and protein content. The contractile fibrils within the cells became organized into parallel arrays, and the cells tended to cluster and beat spontaneously. PGF2 alpha also induced the expression of c-fos, atrial natriuretic factor (ANF), and alpha-skeletal actin in these cells. The effects of PGF2 alpha were compared with several known cardiac myocyte hypertrophy factors (phenylephrine, endothelin-1, leukemia inhibitory factor, cardiotrophin-1, and angiotensin II). PGF2 alpha was found to be intermediate in potency among the factors but induced a level of ANF production that was approximately 10-fold higher than any of the other effectors. Responsiveness to PGF2 alpha was not limited to neonatal cardiocytes. Ventricular myocytes isolated from adult rats also responded specifically to PGF2 alpha with a morphological change similar to that observed with phenylephrine and by producing ANF. In rats, chronic administration of fluprostenol, a potent agonist analogue of PGF2 alpha, resulted in a dose-dependent increase in heart weight- and ventricular weight-to-body weight ratios. The amount of PGF2 alpha extractable from the hearts of rats with cardiac hypertrophy induced by myocardial infarction was also found to be greater than that in sham-operated control rats. These results indicate that PGF2 alpha may play an important role in inducing cardiac hypertrophy.

[Analysis of cinnamic acid in storax and its original plant by HPLC]

The contents of free and hydrolytic cinnamic acid in storax and its original plant (Liquidambar orientalis) were determined by high performance liquid chromatography, and the chromatographic behaviors were studied. In styrax gummi, the contents of free and hydrolytic cinnamic acid were 7.03% and 25.26% respectively; and in its original plant, they were 0.3% evenly.

In vivo effects of cardiotrophin-1

Cardiotrophin-1 (CT-1) is a recently discovered cytokine that was isolated based on its ability to induce cardiac myocyte hypertrophy in vitro. In this study, the effects of chronic administration of CT-1 to mice (0.5 or 2 microg by intraperitoneal injection, twice a day for 14 days) were determined. A dose-dependent increase in both the heart weight and ventricular weight to body ratios was observed in the treated groups. The body weights of the animals were unaffected. These results indicate that CT-1 can induce cardiac hypertrophy in vivo. CT-1 was not specific for the heart, however. It stimulated the growth of the liver, kidney, and spleen, and caused atrophy of the thymus. CT-1 administration also increased the platelet counts by 70%, with no change in mean platelet volume. Red blood cell counts were increased in the treated animals, and there was a concomitant increase in haemoglobin concentration. Thus, CT-1 has a broad spectrum of biological activities in vivo. This observation is consistent with previous in-vitro findings showing that the mRNA for CT-1 is expressed in several tissues, and that CT-1 can function through binding to the leukaemia inhibitory factor (LIF) receptor and signalling through the gp130 pathway.

Signal transduction pathways mediating parathyroid hormone stimulation of bone sialoprotein gene expression in osteoblasts

Bone sialoprotein is a major noncollagenous protein of bone. Parathyroid hormone (PTH) was shown to cause a 2-4-fold increase in the steady-state levels of bone sialoprotein mRNAs within primary cultures of embryonic osteoblasts. The induction could be mimicked by both forskolin and phorbol 12-myristate 13-acetate and was not inhibited by cycloheximide. Transient expression of a approximately 1200-base pair avian 5' bsp promoter/reporter construct demonstrated similar inductions as mRNA levels. Co-transfection of an expression plasmid encoding heat-stable inhibitor of cAMP-dependent protein kinase, a peptide inhibitor of PKA, decreased both the basal and PTH-induced bsp transcription, while co-expression of the catalytic subunit of PKA-induced bsp expression 3-fold. Protein kinase C activation, on the other hand, did not appear to work through its activation of c-fos, since co-transfection of an expression clone for c-fos had no effect. Interestingly, heat-stable inhibitor of cAMP-dependent protein kinase also inhibited the phorbol 12-myristate 13-acetate induction, suggesting that the protein kinase C acts through some form of interaction with the cAMP/PKA pathway. A half-cAMP response element site in the bsp promoter was identified as the cis-acting element that mediated the PTH response by the transient transfections with reporter constructs containing nested deletions of the promoter or a heterologous promoter containing the cAMP response element. In conclusion, these data indicate that PTH stimulation of bsp gene expression is specific to osteoblasts and mediated by changing cellular cAMP/PKA levels. They further suggest that although protein kinase C is capable of stimulating the gene by itself, it plays a minimal role in mediating the PTH induction of bone sialoprotein.

[Effects of iodine and thyroid hormone deficiency during brain development on activities of cholinergic neurone-related enzymes in central nervous system of rats]

To study the effects of iodine and thyroid hormone deficiency during brain development on activities of enzymes of central acetyl choline metabolism, activities of choline acetylcholinetransferase (CHAT) and acetylcholinesterase (AChE) in hippocampus and cerebral cortex, basal forebrain and cerebellum in 20-day-old rats were determined. Results showed that CHAT and AChE activities in hippocampus, cerebral cortex and basal forebrain in iodine deficiency and hypothyroid rats were significantly lower than those in controls. A ratio of membranebound AChE to soluble AChE, activities of inextractable AChE, and percentage of its activities in the four sections of the brain in the trial rats were significantly lower, and activities of soluble AChE and its percentage of activities were significantly higher than those in controls. It suggests iodine and thyroid hormone deficiency could affect maturation of CHAT and disturb transformation and maturation of various molecular types of AChE and delay distinctly the development of cholinergic neurone during the critical period of brain development in rats.

Accessing genetic information with high-density DNA arrays

Rapid access to genetic information is central to the revolution taking place in molecular genetics. The simultaneous analysis of the entire human mitochondrial genome is described here. DNA arrays containing up to 135,000 probes complementary to the 16.6-kilobase human mitochondrial genome were generated by light-directed chemical synthesis. A two-color labeling scheme was developed that allows simultaneous comparison of a polymorphic target to a reference DNA or RNA. Complete hybridization patterns were revealed in a matter of minutes. Sequence polymorphisms were detected with single-base resolution and unprecedented efficiency. The methods described are generic and can be used to address a variety of questions in molecular genetics including gene expression, genetic linkage, and genetic variability.

Prevalence of vertebral fractures in chinese men and women in urban Taiwanese communities

Reports on the prevalence (or incidence) rates of vertebral fracture have been available, but they are limited concerning non-white populations and men of all races. This study used the radiomorphometric method to survey the prevalence rate of vertebral fracture for ethnic Chinese women 40 years and older and Chinese men 65 and older who were randomly selected from four major cities in Taiwan. Three sets of reference values of the height ratios were used for middle-aged women, elderly women, and elderly men. The results showed that in Chinese women, the prevalence rate of vertebral fracture was low before age 50 and showed a steady increase thereafter. In men, the increase was small until age 80. The overall adjusted prevalence rate of vertebral fracture for women older than 65 was 20% and that for men, 12.5% (95% confidence interval 18-22% and 11-14%, respectively.) If only severe deformity was counted [height ratio lower than normal mean minus 4 standard deviations (SD), or Grade II deformity], the adjusted prevalence rate was 15.5% for elderly women and 9.5% for elderly men (95% confidence interval 14-17%, and 8-11%, respectively.) The overall adjusted prevalence rate for women aged 40 and over was 6.8% (95% confidence interval 5.7-8%), or 4.5% (95% confidence interval 3.6-5. 5%) for Grade II lesions. Moreover, for subjects with fracture, elderly women tended to have more fractured vertebrae per person and more Grade II fractures than elderly men. Thus, Chinese women residing in cities of Taiwan had a relatively high prevalence rate of vertebral fracture, a finding compatible with that for United States or European white women, or for Japanese women residing in America. Elderly Chinese men also have a high prevalence rate of vertebral fracture. The age-specific female-to-male ratio of prevalence rate was about 1.5 to 2.3 between age 65 and 80, and close to unity after age 80.

[The coronary artery structure and early atherosclerotic lesions of 80 young adults cases in the Ningbo fishing region]

In order to study the coronary artery structure in relation to early atherosclerotic lesions of young adults residing in a fishing region, coronary arteries from 80 autopsies of people aged 15 to 39 years who died from accidents were collected and studied by pathohistological, immunohistochemical and morphometric methods. The results showed an 18.67% prevalence of Sudanophilic lesions in the right, coronary artery, the thickness of the intima of the left anterior descending branch increased with increasing age in males, but no significant difference was observed in females, the density of the coronary artery cell nuclei decreased with increasing age. The prevalence of fatty streaks and stenosis of left anterior descending branch was 25.0% and 5.0% respectively, and that of the left circumflex branch was 7.5% and 3.9% respectively. The amount of chondroinn sulfate proteoglycan in the left anterior descending branch was 23.3 +/- 8.8% in intima and 12.0 +/- 4.0% in the media. The above findings suggest that the custom of eating large amounts of sea food may have a beneficial effect on lipid deposit, smooth muscle cell proliferation, thickness of intima and percentage of proteoglycan. Thus it is one of the important factors for the low incidence of coronary heart disease in this fishing region.

Novel analog of atrial natriuretic peptide selective for receptor-A produces increased diuresis and natriuresis in rats

Atrial natriuretic peptide (ANP) binds to natriuretic peptide receptor-A (NPR-A), a membrane guanylyl cyclase, and to natriuretic peptide receptor-C (NPR-C), which plays a role in peptide clearance. Rat ANP (rANP) mutants that bind rat NPR-A selectively over rat NPR-C were isolated from randomized libraries of rANP-display phage by differential panning. One variant was identified with reduced NPR-C binding; rANP (G16R, A17E, Q18A) [rANP(REA18)]. Synthetic rANP(REA18) was equipotent with rANP in stimulating cGMP production from cloned rat NPR-A (ED50 = 1.8 nM) and was reduced in NPR-C binding by approximately 200-fold. When infused into conscious rats at 0.325 microg/min for 30 min rANP elicited an identical decrease in blood pressure compared with 0.25 microg/min of rANP(REA18), however the natriuretic (P < 0.05) and diuretic (P = 0.07) responses to rANP(REA18) were greater. These data are consistent with a role for NPR-C as a local decoy receptor attenuating NPR-A effects in the kidney, where these receptors are coexpressed. Improved NPR-A specificity could provide more effective natriuretic peptides for treatment of acute renal failure or heart failure.

Alpha-1-proteinase inhibitor prolongs small intestinal graft preservation and survival

Organ preservation solutions currently used for cold storage of human donor organs are less effective in preserving small intestinal grafts than other organ grafts. The maximal safe period of cold preservation for human small intestinal graft is only about 6 hours. The pathology of preserved and reperfused small intestinal grafts is characterized by mucosal autolysis and sloughing. The authors speculated that the preservation/reperfusion injury results from a proteinase/proteinase-inhibitor imbalance in the graft that favors tissue degradation. This study evaluates whether the addition of an alpha-1-proteinase inhibitor (alpha-1-PI) to the preservation solution can improve graft survival after small bowel transplantation. Forty small intestinal grafts (20 cm long) were harvested from Lewis rats. The grafts were divided randomly into three groups and were preserved in one of the following solutions: normal saline (NS) (n = 10), alpha-1-PI (25 mg/mL; n = 20), or proteinase-free bovine serum albumin (BSA) (25 mg/mL; n = 10). After 12-hour cold storage in the respective solutions, the grafts were transplanted orthotopically into syngeneic recipients. Full-thickness graft biopsies were performed before and 1 hour after revascularization. The effectiveness of preservation was judged by graft histopathology and recipient survival. Histological studies showed that there was less mucosal autolysis and sloughing of the grafts in the alpha-1-Pl group than in the other two groups. All recipients in the NS and BSA groups died of graft failure within 7 days (NS: median, 4 days; range, 2 to 5 days; BSA: median, 6 days; range, 4 to 7). However, 60% (12 of 20) of the recipients in the alpha-1-PI group survived more than 90 days (median, > 90 days; range, 4 to > 90 days; P < .005 v NS or BSA groups, log-rank method). These data suggest that the inclusion of alpha-1-PI in the preservation solution may enhance graft integrity and improve the surgical outcome after small bowel transplantation.

Extensive polymorphisms observed in HIV-1 clade B protease gene using high-density oligonucleotide arrays

Naturally occurring mutations in HIV-1-infected patients have important implications for therapy and the outcome of clinical studies. However, little is known about the prevalence of mutations that confer resistance to HIV-1 protease inhibitors in isolates derived from patients naive for such inhibitors. In the first clinical application of high-density oligonucleotide array sequencing, the sequences of 167 viral isolates from 102 patients have been determined. The DNA sequence of USA HIV-1 clade B proteases was found to be extremely variable and 47.5% of the 99 amino acid positions varied. This level of amino acid diversity is greater than that previously known for all worldwide HIV-1 clades combined (40%). Many of the amino acid changes that are known to contribute to drug resistance occurred as natural polymorphisms in isolates from patients who had never received protease inhibitors.

Effects of vascular endothelial growth factor on hemodynamics and cardiac performance

Vascular endothelial growth factor (VEGF), a major regulator of angiogenesis, has therapeutic benefit in animal models of coronary or limb ischemia. However, the hemodynamic effects of VEGF have not been investigated. We examined the effects of VEGF on hemodynamics and cardiac performance. Mean arterial pressure (MAP), heart rate (HR), cardiac output, stroke volume, left ventricular (LV) dP/dt, and hematocrit were measured before and after intravenous injection of VEGF in conscious, instrumented rats. VEGF caused a dose-dependent reduction in MAP and an associated increase in HR. VEGF (250 micrograms/kg) significantly decreased cardiac output and stroke volume without affecting the inotropic state of the left ventricle, as determined by dP/dt. VEGF significantly increased hematocrit. Furthermore, VEGF did not affect contractility or HR in the isolated rat heart in vitro. The data suggest that the VEGF-induced decrease in cardiac output is due to reduced stroke volume, which may be caused by a decrease in venous return rather than a direct effect on myocardial contractility. In addition, pretreatment with N omega-nitro-L-arginine methyl-ester (L-NAME), a nitric oxide (NO) synthase inhibitor, significantly attenuated the depressor and tachycardic responses to VEGF, suggesting that VEGF-induced hypotension may be mediated by NO.