Risk factors from Framingham risk score for anthracyclines cardiotoxicity in breast cancer: A systematic review and meta-analysis

Background

Framingham risk score (FRS) is an effective tool for evaluating the 10-year risk of cardiovascular diseases. However, the sensitivity of FRS for anthracycline-induced cardiotoxicity is unclear. This meta-analysis aims to evaluate the correlation between risk factors (hypertension, hyperlipidemia, diabetes, smoking, and obesity) in FRS and anthracycline-induced cardiotoxicity in breast cancer.

Methods

We searched PubMed, EMBASE, and Cochrane Library for studies published from inception to January 2022 which reported cardiotoxicity due to anthracycline. Cardiotoxicity defined as any cardiac events were used as the primary endpoint. A total of 33 studies involving 55,708 breast cancer patients treated with anthracyclines were included in this meta-analysis.

Results

At least one risk factor was identified at baseline for the 55,708 breast cancer patients treated with anthracycline. Hypertension [I ² = 45%, Fixed, RR (95% CI) = 1.40 (1.22, 1.60), p < 0.00001], hyperlipidemia [I ² = 0%, Fixed, RR (95% CI): 1.35 (1.12, 1.62), p = 0.002], diabetes [I ² = 0%, Fixed, RR (95% CI): 1.29 (1.05, 1.57), p = 0.01], and obesity [I ² = 0%, Fixed, RR (95% CI): 1.32 (1.05, 1.67), p = 0.02] were associated with increased risks of cardiac events. In addition, smoking was also associated with reduced left ventricular ejection fraction (LVEF) during anthracycline chemotherapy [I ² = 0%, Fixed, OR (95% CI): 1.91 (1.24, 2.95), p = 0.003] in studies that recorded only the odds ratio (OR).

Conclusion

Hypertension, hyperlipidemia, diabetes, smoking, and obesity are associated with increased risks of anthracycline-induced cardiotoxicity. Therefore, corresponding measures should be used to manage cardiovascular risk factors in breast cancer during and after anthracycline treatment.

Association between plasma endothelial microparticles and contrast-induced nephropathy in patients underwent coronary angiography

We aim to investigate the association between plasma endothelial microparticles (EMPs) and contrast-induced nephropathy of patients underwent coronary angiography.The patients were divided into normal renal function group and renal dysfunction group based on the estimated glomerular filtration rate (eGFR). Among the 180 cases, 117 received determination of EMP and serum creatinine after percutaneous coronary intervention (PCI) and/or coronary angiography. The patients were divided into contrast-induced-nephropathy (CIN) group and non-CIN group. EMPs collection and determination were performed, together with biochemical analysis and digital subtraction angiography (DSA) analysis.Spearman correlation showed that the expression of EMP was negatively correlated with eGFR (r = -0.201, P < .01). The serum hypersensitive C-reactive protein (hs-CRP), cystatin C (Cys-C), uric acid (UA) were significantly higher in CIN group than that in the non CIN group. Spearman correlation showed that the expression of EMP was positively correlated with serum interleukin-6 (IL-6, r = 0.393, P < .01). The expression of EMP was positively correlated with serum hs-CRP (r = 0.360, P < .01). Logistic regression analysis showed that the levels of N-terminal pro-brain natriuretic peptide (NT-proBNP), eGFR, UA, and Cys-C were correlated with the incidence of contrast induced nephropathy.In patients with contrast-induced-nephropathy, the plasma EMPs were significantly increased after coronary angiography. The expression of plasma EMPs may play a role in the occurrence of contrast-induced-nephropathy.

Sarpogrelate and rosuvastatin synergistically ameliorate aortic damage induced by hyperlipidemia in apolipoprotein E-deficient mice

The current study aimed to investigate whether sarpogrelate and rosuvastatin possess anti-arterial injury, and attempted to elucidate the mechanism of action underlying this activity. Sarpogrelate, a 5-hydroxytryptamine type 2A antagonist, is extensively used to prevent arterial thrombosis; however, its effects on atherosclerosis remain unknown. In the present study, sarpogrelate combined with rosuvastatin or rosuvastatin alone were administered to male ApoE^-/- mice fed a high-fat diet (HFD) for 8 weeks. Metabolic parameters in the blood samples were analyzed using an automatic analyzer. Aortic tissues were stained with hematoxylin and eosin for morphological analysis. The expression levels of oxidized-low density lipoprotein (LDL) specific scavenging receptors, lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) and cluster of differentiation 68 were detected via immunostaining. mRNA expression levels of interleukin (IL)-1β, IL-6 and tumor necrosis factor-α were determined via reverse transcription-quantitative PCR analysis, while protein expression levels of LOX-1 and phosphor(p)-ERK were determined via western blot analysis. The results demonstrated that sarpogrelate combined with rosuvastatin treatment significantly decreased total cholesterol and LDL cholesterol levels in the serum, and alleviated intimal hyperplasia and lipid deposition, accompanied by decreased inflammatory cell infiltration and lower expression levels of inflammatory cytokines, compared with rosuvastatin monotherapy or HFD treatment. Furthermore, sarpogrelate combined with rosuvastatin treatment significantly decreased the expression levels of LOX-1 and p-ERK. Taken together, these results suggest that the positive effects of sarpogrelate combined with rosuvastatin treatment on aortic injury may be associated with the regulation of the LOX-1/p-ERK signaling pathway. Sarpogrelate and rosuvastatin synergistically decreased aortic damage in ApoE^-/- HFD mice, and thus provide a basis for the treatment of aortic injury caused by hyperlipidemia with sarpogrelate.

Effect of ticagrelor and clopidogrel on platelet aggregation function after percutaneous coronary intervention in patients with acute coronary syndrome

In this study, phosphorylation levels of vasodilator stimulated phosphoprotein (VASP) were detected by flow cytometry (FCM) to investigate the effects of ticagrelor and clopidogrel on platelet aggregation function (PAF) after percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS).

Blockage of macrophage migration inhibitory factor (MIF) suppressed uric acid-induced vascular inflammation, smooth muscle cell de-differentiation, and remodeling

Hyperuricemia contributes to vascular injury and dysfunction, yet the potential mechanisms are not well understood. Uric acid (UA) has been found to stimulate macrophage migration inhibitory factor (MIF) up-regulation in renal tubules from rats subjected to UA-induced nephropathy. Given that MIF is able to induce vascular smooth muscle cell (VSMC) de-differentiation (from contractile state to a secretory state), we thus hypothesized that UA-induced vascular injury is via up-regulating of MIF in VSMCs, which enhancing vascular inflammation and VSMC transition. Within a mouse model of UA injection (500 mg/kg, twice/day, 14 days), we measured circulating and vascular MIF levels under UA stimulation at 6 h, day 1, and 14. We tested the efficacy of MIF inhibitor (10 mg/kg, twice/day, 14 days) on UA-induced vascular inflammation and remodeling. High plasma level of UA induced vascular MIF release into the plasma at acute phase. In the chronic phase, the protein level of MIF is up-regulated in the vessels. MIF inhibitor suppressed vascular inflammatory responses, repressed VSMC de-differentiation, and attenuated vascular remodeling and dysfunction following UA stimulation. Knockdown of MIF in cultured VSMCs repressed UA-induced de-differentiation. Our results provided a novel mechanism for MIF-mediated vascular injury in response to UA stimulation, and suggested that anti-MIF interventions may be of therapeutic value in hyperuricemic patients.

MiR-373-3p enhances the chemosensitivity of gemcitabine through cell cycle pathway by targeting CCND2 in pancreatic carcinoma cells

OBJECTIVE

This study aimed to detect the expression of miR-373-3p and CCND2 in gemcitabine-resistance pancreatic carcinoma (PC) cells, investigate the relationship between miR-373-3p and CCND2, and explore their effects on PC propagation, migration, invasion and apoptosis.

METHODS

R software was applied for analyzing differentially expressed genes (DEGs) in cell samples. The potential biological pathway was determined by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, based on R software. The gemcitabine-resistance PC cells were screened out using MTT assay, and they were applied in the next experiments. MiR-373-3p and CCND2 expression in GEM-PANC-1 cells were measured by qRT-PCR. After transfection, the expression of CCND2 protein was examined via western blot assay. Cells viability and apoptosis were confirmed by MTT proliferation assay and Flow cytometry, whereas cells migration and invasion were analyzed by transwell assay. The targeting relationship between miR-373-3p and CCND2 was identified by dual-luciferase reporter assay.

RESULTS

MiR-373-3p was found to be low expressed in GEM-PANC-1 cells while CCND2 was highly expressed in GEM-PANC-1 cells. MiR-373-3p negatively regulated CCND2 expression through KEGG_Cell_Cycle_Signaling_Pathway. The targeted relationship between miR-373-3p and CCND2 could be verified using dual luciferase reporter assay. MTT proliferation assay, transwell assay and Annexin V assay demonstrated that miR-373-3p suppressed GEM-PANC-1 cells propagation and invasion and promoted cell apoptosis, while CCND2 showed totally reverse effects compared with miR-373-3p. All the results suggested that miR-373-3p could enhance the chemosensitivity of GEM-PANC-1 cells by regulating CCND2.

CONCLUSION

MiR-373-3p inhibited cell propagation, migration and invasion and boosted apoptosis in gemcitabine resistance pancreatic carcinoma cells by targeting CCND2.

The characterisation of overweight and obese women who are under reporting energy intake during pregnancy

Background

Misreporting of energy intake is common and can contribute to biased estimates of the relationship between diet and disease. Energy intake misreporting is poorly understood in pregnancy and there is limited research assessing characteristics of women who misreport energy intake or changes in misreporting of energy intake across pregnancy.

Methods

An observational study in n = 945 overweight or obese pregnant women receiving standard antenatal care who participated in the LIMIT randomised trial. Diet, physical activity, psychological factors, body image satisfaction and dieting behaviour were assessed at trial entry (10–20 weeks gestation) and 36 weeks gestation. Energy misreporting status was assessed through the ratio of daily energy intake over basal metabolic rate. Logistic regression analyses were conducted with the dependent variable of under reporting of energy intake at study entry or 36 weeks in separate analysis.

Results

At study entry and 36 weeks, women were classified as under reporters (38 vs 49.4%), adequate reporters (59.7 vs 49.8%) or over reporters of energy intake (2.3 vs 0.8%) respectively. The prevalence of under reporting energy intake at 36 weeks was higher than at study entry (early pregnancy). Body mass index (BMI) at study entry and 36 weeks and socioeconomic status, dieting behaviour and risk of depression at 36 weeks were independent predictors of under reporting of energy intake.

Conclusions

Under reporting of energy intake was present in over a third of overweight and obese pregnant women and was higher in late compared to early pregnancy. Characteristics such as BMI, socioeconomic status, past dieting behaviour and risk of depression may aid in identifying women who either require support in accurate recording of food intake or attention for improving diet quality. Results were unable to distinguish whether under reporting reflects misreporting or a true restriction of dietary intake.

Trial registration

Australian and New Zealand Clinical Trials Registry ACTRN12607000161426, registered 9/3/2007.

Electronic supplementary material

The online version of this article (10.1186/s12884-018-1826-x) contains supplementary material, which is available to authorized users.

Stereochemical considerations in pharmacokinetic processes of representative antineoplastic agents

The vast majority of chemical drugs or drug candidates contain stereocenter(s) in their molecular structures. In these molecules, stereochemical properties are vital properties that influence or even determine their drug actions. Therefore, studying the stereochemical issues of drugs (or drug candidates) is necessary for rational drug use. These stereochemical issues are usually involved with the stereoselectivity in pharmacokinetic processes, especially in the metabolism process. Thus, the investigation of the stereochemical issues in drug metabolism process deserves great attention, especially in those chiral/prochiral antineoplastic agents exhibiting pharmacodynamics and toxicologic differences between stereoisomers. Published reviews concerning this certain issue are inspiring, however they were covering all drug types and only limited antineoplastic drugs were discussed. Here in this review, the research on stereochemical issues in pharmacokinetic processes of some representative antineoplastic agents were described, especially focusing on some newly developed compounds. We highlight the chemical transformations in pharmacokinetic processes of these chiral/prochiral compounds and discuss their different behaviors with metabolic enzymes or transporter proteins, to explicate the observed stereoselectivity intrinsically.

Catanionic lipid nanosystems improve pharmacokinetics and anti-lung cancer activity of curcumin

Novel catanionic lipid nanosystems (CLNs) incorporating curcumin (CCM) were developed, and improvements in pharmacokinetics and enhanced anti-lung cancer activity were observed. CCM was present in a lipid matrix surrounded by cationic, anionic and zwitterionic surfactants, forming the core-shell nanosystems. Compared with free CCM, the CCM-CLNs had much higher oral and intravenous bioavailabilities due to enhanced absorption and reduced clearance. The CCM-CLNs exhibited greater cytotoxicity in Lewis lung cancer (LLC) cells, which might have been due to increased antiproliferative, proapoptotic and anti-invasive activities and induction of cell cycle arrest. The CCM-CLNs increased the antitumor efficacy of CCM and decreased the tumor growth rate in tumor-bearing mice. This is the first report of induction of apoptosis in LLC cells by CCM through the PI3K/Akt/FoxO1/Bim signaling pathway. Catanionic lipid nanocarriers show promise for the therapeutic delivery of insoluble anti-tumor drugs.

A decrease in diet quality occurs during pregnancy in overweight and obese women which is maintained post-partum

BACKGROUND

Ensuring adequate dietary intake during pregnancy has important implications for optimising maternal and fetal health. It is not known whether diet quality is altered over pregnancy and the post-partum period.

OBJECTIVE

The aim of this study was to perform a comprehensive assessment of diet quality in overweight and obese women during pregnancy and early post-partum.

DESIGN

In a prospective cohort study, n=301 overweight or obese pregnant women completed a food frequency questionnaire at study entry (10-20 weeks gestation), 28 weeks gestation, 36 weeks gestation and 4 months post-partum for assessment of macronutrient and micronutrient intake and diet quality by the Healthy Eating Index (HEI).

RESULTS

Energy, macronutrient and dietary sources of micronutrients did not alter across pregnancy or post-partum. The HEI was of below average quality in 31.0% of women at baseline. This decreased from week 28 (P<0.001) and was maintained at a lower level post-partum such that HEI levels were lower compared with study entry (53.3±12.7 versus 56.7±10.1, P<0.001). The HEI decrease occurred in association with decreases in the milk, meat and unsaturated oil components, and increases in the proportion of energy from solid fats, alcohol and added sugars (P<0.001), and was independently predicted by the socioeconomic index for areas score (β=-0.011, s.e.=0.011, P=0.031).

CONCLUSION

We report for the first time that dietary quality decreases across pregnancy and is maintained at this reduced level in the early post-partum period in overweight and obese women. Dietary interventions aimed at improving diet quality should be targeted to early pregnancy and post-partum.

JNJ-10280205 and JNJ-10287069: novel PDE5 inhibitors as clinical candidates for erectile dysfunction

Phosphodiesterase 5 (PDE5) inhibitors are efficacious in treating patients with erectile dysfunction. New PDE5 inhibitors with different selectivity and pharmacokinetic profiles have been vigorously pursued. Here we report two novel, potent, and selective PDE5 inhibitors, JNJ-10280205 and JNJ-10287069, with Ki values of 0.05 and 0.12 nM, respectively. Both compounds displayed superior selectivity against PDE1-4 and -6 when compared to sildenafil. In the anesthetized dogs, JNJ-10280205 and JNJ-10287069 exhibited similar efficacy as sildenafil in enhancing erectile functions, with no significant effect on cardiovascular parameters. Pharmacokinetic studies showed that JNJ-10287069 had better oral bioavailability than JNJ-10280205 in several animal species. In vitro study suggested that cytochrome P450 (CYP) 3A4 played a major role in the metabolism of both compounds. The compounds inhibited some of the CYP450 enzymes and the human ether-a-go-go (HERG) channel at much higher concentrations than that required to inhibit PDE5, thus, no cross inhibition would be expected at therapeutic doses. Both compounds are suitable clinical candidates.

Non-Steroidal Progesterone Receptor Specific Ligands

The nuclear receptor for progesterone is a target for contraception and for several therapeutic indications. Progestin agonists and antagonists in clinical use mimic the steroidal backbone of the cognate ligand, progesterone. Thus, they have significant cross-reactivity with other steroid receptors. Recently, non-steroidal progesterone receptor ligands have begun to appear in the literature. This review will describe the current status of research into these promising new chemical entities.

Effect of chronic and acute cigarette smoking on the pharyngoglottal closure reflex

BACKGROUND

Injection of water into the pharynx at a threshold volume induces vocal cord adduction--the pharyngoglottal closure reflex (PGCR). This reflex together with other supraoesophageal reflexes may be helpful in preventing aspiration. Cigarette smoking has an adverse affect on the pharyngo-upper oesophageal sphincter contractile reflex and reflexive pharyngeal swallow. The effect of smoking on PGCR has not been studied previously.

AIMS

To elucidate the effect of chronic and acute cigarette smoking on PGCR.

SUBJECTS

We studied 10 chronic smokers and 10 non-smokers before and after real/simulated smoking, respectively.

METHODS

Using concurrent recordings, glottal function was monitored by video endoscopy, swallowing by electromyography, and PGCR was triggered by rapid and slow pharyngeal water injections.

RESULTS

The threshold volume to trigger PGCR during rapid injection was significantly higher in chronic smokers (non-smoker 0.20 (SEM 0.02) ml, smoker 0.36 (0.02) ml; p<0.001). In six of 10 smokers, acute smoking abolished this reflex during slow water injection.

CONCLUSIONS

Smoking adversely affects stimulation of PGCR. This finding may have implications in the development of reflux related respiratory complications in smokers.

Deterioration of the pharyngo-UES contractile reflex in the elderly

OBJECTIVES/HYPOTHESIS

Deterioration of aerodigestive tract reflexes such as the esophagoglottal and pharyngoglottal closure reflexes and pharyngeal swallow has been documented in the elderly. However, the effect of aging on the contractile response of the upper esophageal sphincter (UES) to pharyngeal water stimulation has not been studied. The aim of this study was to characterize the pharyngo-UES reflex in the healthy elderly.

METHODS

We studied nine healthy elderly (77 +/- 1 y [SD]; four men, five women) and nine healthy young volunteers (26 +/- 2 y [SD]; four men, five women). AUES sleeve sensor was used to measure the pressure. We tested pharyngeal stimulation induced by rapid pulse and slow continuous injection of water.

RESULTS

The volume of water required to stimulate the pharyngo-UES contractile reflex by rapid pulse injection in the elderly (0.5 +/- 34 0.1 mL) was significantly higher than that in the young (0.1 +/- 0.02 mL) (P < .05). In contrast to young subjects, there was no pressure increase in resting UES pressure observed in the elderly for continuous pharyngeal water infusion. In both young and elderly, the threshold volume for the pharyngo-UES contractile reflex was significantly lower than that for pharyngeal swallows.

CONCLUSIONS

The pharyngo-UES contractile reflex deteriorates with aging. This deterioration is primarily due to abnormalities of the afferent limb of the reflex.

Upper esophageal sphincter function during gastroesophageal reflux events revisited

Upper esophageal sphincter (UES) function during gastroesophageal reflux events is not completely elucidated because previous studies addressing this issue yielded conflicting results. We reexamined the UES pressure response to intraluminal esophageal pressure and pH changes induced by reflux events. We studied 14 healthy, asymptomatic volunteers (age 49 +/- 6 yr) and 7 gastroesophageal reflux disease patients (age 48 +/- 5 yr). UES pressure, intraesophageal pressure, and pH were monitored at the distal, middle, and proximal esophagus concurrently in the supine position 1 h before and 2 h after a 1,000-calorie meal. A total of 321 reflux events were identified by the development of abrupt reflux-induced intraesophageal pressure increase (IPI); 285 events occurred in patients and 36 in control subjects. In control subjects 33 of 36 and in patients 252 of 285 IPI events were associated with a pH drop. Among patients and control subjects, 99% and 100%, respectively, of all IPI events irrespective of pH drop were associated with abrupt increase in UES pressure (34 +/- 2 and 27 +/- 6 mmHg, respectively). The average percentage of maximum UES pressure increase over prereflux values ranged between 66% and 96% (control subjects) and 34% and 122% (patients). IPIs induced by both acidic and nonacidic reflux events evoke strong UES contractile responses.

1,3-Diarylcycloalkanopyrazoles and diphenyl hydrazides as selective inhibitors of cyclooxygenase-2

Novel 1,3-diarylcycloalkanopyrazoles 1, and diphenyl hydrazides 2 were identified as selective inhibitors of cyclooxygenase-2. The 1,3-diaryl substitution pattern of the pyrazole ring in 1 differentiates these compounds from most of the known selective COX-2 inhibitors that contain two aryl rings at the adjacent positions on a heterocyclic or a phenyl ring. Similarly, the two phenyl rings in 2 are also separated by three atoms. SAR of both phenyl rings in 1 and 2, and the aliphatic ring in 1 will be discussed.

Effect of chronic and acute cigarette smoking on the pharyngo-upper oesophageal sphincter contractile reflex and reflexive pharyngeal swallow

BACKGROUND

Cigarette smoking is known to affect adversely the defence mechanisms against gastro-oesophageal reflux. The effect of smoking on the supraoesophageal reflexes that prevent aspiration of gastric contents has not been previously studied.

AIMS

To elucidate the effect of cigarette smoking on two of the supraoesophageal reflexes: the pharyngo-upper oesophageal sphincter (UOS) contractile reflex; and the reflexive pharyngeal swallow.

METHODS

Ten chronic smokers and 10 non-smokers were studied, before and 10 minutes after real or simulated smoking, respectively. UOS pressure and threshold volume for the reflexes were determined using a UOS sleeve assembly. Two modes of fluid delivery into the pharynx were tested: rapid injection and slow injection.

RESULTS

For both rapid and slow injections, the threshold volume for triggering the pharyngo-UOS contractile reflex was significantly higher in smokers than in non-smokers (rapid: smokers 0.42 (SE 0.07) ml, non-smokers 0.16 (0. 04) ml; slow: smokers 0.86 (0.06) ml, non-smokers 0.38 (0.1) ml; p<0. 05). During rapid injection, the threshold volume for reflexive pharyngeal swallow was higher in smokers (smokers 0.94 (0.09) ml, non-smokers 0.46 (0.05) ml; p<0.05). Acute smoking further increased the threshold volume for the pharyngo-UOS contractile reflex and reflexive pharyngeal swallow during rapid injection.

CONCLUSIONS

Smoking adversely affects stimulation of the pharyngo-UOS contractile reflex and pharyngeal reflexive swallow. These findings may have implications in the development of reflux related respiratory complications among smokers.

Substituted salicylanilides as inhibitors of two-component regulatory systems in bacteria

A new class of inhibitors of the two-component regulatory systems (TCS) of bacteria was discovered based on the salicylanilide screening hits, closantel (1) and tetrachlorosalicylanilide (9). A systematic SAR study versus a model TCS, KinA/Spo0F, demonstrated the importance of electron-attracting substituents in the salicyloyl ring and hydrophobic groups in the anilide moiety for optimal activity. In addition, derivatives 8 and 16, containing the 2, 3-dihydroxybenzanilide structural motif, were potent inhibitors of the autophosphorylation of the KinA kinase, with IC50s of 2.8 and 6. 3 &microM, respectively. Compound 8 also inhibited the TCS mediating vancomycin resistance (VanS/VanR) in a genetically engineered Enterococcus faecalis cell line at concentrations subinhibitory for growth. Closantel (1), tetrachlorosalicylanilide (9), and several related derivatives (2, 7, 10, 11, 20) had antibacterial activity against the drug-resistant organisms, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VREF).

SAR studies of diaryltriazoles against bacterial two-component regulatory systems and their antibacterial activities

A series of diaryltriazole analogs was discovered to inhibit bacterial two-component regulatory systems in our primary assays, KinA/Spo0F and NRII/NRI. They also showed inhibitory activity in whole cell mechanism-based assays, and they possessed potent activities against several strains of Gram-positive pathogenic bacteria in the standard MIC broth assay.

Novel inhibitors of bacterial two-component systems with gram positive antibacterial activity: pharmacophore identification based on the screening hit closantel

This SAR study has shown that the salicylanilide is the pharmacophore for inhibition of the bacterial two-component system. Hydrophobic substituents improve the potency of inhibitors in this series; however, hydrophobicity is not the sole determinant for inhibition; structural and electronic requirements also exist. Closantel (1) was found to inhibit a two-component system and to have antibacterial activity against drug resistant S. aureus and E. faecium.

Synthesis and inhibitory activity of novel tri- and tetracyclic quinolines against topoisomerases

A series of isoindolo[2,1-a]- and pyrrolo[1,2-a]quinolines were designed and synthesized for DNA-gyrase and topoisomerase-II inhibition studies. Some of the compounds showed significant activity against the enzymes.

Characterization of the pharyngo-UES contractile reflex in humans

Preliminary human studies suggest the presence of an upper esophageal sphincter (UES) contractile reflex triggered by pharyngeal water stimulation. The purposes of this study were to further characterize this reflex and determine the threshold volume for its activation. We studied 10 healthy young volunteers by manometric technique before and after topical pharyngeal anesthesia. UES pressure responses to various volumes and temperatures of water injected into the pharynx were elucidated. At a threshold volume, rapid-pulse and slow continuous pharyngeal water injection resulted in significant augmentation of UES pressure in all volunteers. Threshold volume for inducing UES contraction averaged 0.1 +/- 0.01 ml for rapid-pulse injection and was significantly smaller than that for slow continuous injection (1.0 +/- 0.2 ml). UES pressure increase duration averaged 16 +/- 4 s. Augmentation of UES resting tone by injection of water with three different temperatures was similar. This augmentation was abolished after topical anesthesia. Conclusions were that stimulation of the human pharynx by injection of minute amounts of water results in a significant increase in resting UES pressure: the pharyngo-UES contractile reflex. The magnitude of pressure increase due to activation of this reflex is not volume or temperature dependent. Loss of pharyngeal sensation abolishes this reflex.

Frequency of gastroesophageal reflux events induced by pharyngeal water stimulation in young and elderly subjects

Earlier studies have shown that isolated complete lower esophageal sphincter (LES) relaxation occurs as a result of pharyngeal water stimulation. Association of these relaxations with gastroesophageal reflux has not been studied systematically. Our aim was to determine this association in young and elderly subjects during precibal and postprandial periods. We studied 8 young subjects and 10 elderly subjects for 1 h before and 2 h after a 1,000-cal meal. In both groups, during the precibal period, negligible LES relaxation induced by pharyngeal water stimulation resulted in gastroesophageal reflux. In the postprandial period, gastroesophageal reflux events occurred after 16% of pharyngeal water injections in young subjects and after 44% in elderly subjects (P < 0.05). Intraabdominal length of the LES in elderly subjects was significantly shorter compared with younger subjects (P < 0.05). We conclude that gastroesophageal reflux events induced by pharyngeal water stimulation in the postprandial period are significantly increased compared with those of the precibal period and are significantly more prevalent in the elderly compared with the young. These differences seem to be associated with a significantly shorter intra-abdominal segment of the LES in the elderly.

Oxidation of omega-oxo fatty acids by cytochrome P450BM-3 (CYP102)

Cytochrome P450 enzymes oxidize aldehydes either to the corresponding acid or, via a decarboxylation mechanism, to an olefin one carbon shorter than the parent substrate. To explore the factors that control partitioning between these two pathways, we have examined the cytochrome P450BM-3 (CYP102)-catalyzed oxidation of fatty acids with a terminal aldehyde group. P450BM-3 oxidizes 18-oxooctadecanoic, 16-oxohexadecanoic, 14-oxotetradecanoic, and 12-oxododecanoic acids exclusively to the corresponding alpha,omega-diacids. The rates of these oxidations decrease in the order C16 > C18 approximately = C14 > C12. No kinetic isotope effect is observed nor is the catalytic outcome altered when the aldehyde hydrogen is replaced by a deuterium in 16-oxohexadecanoic acid. The only product observed with 16-oxohexadecanoic acid is the diacid even when a 13,14-double bond or 15-methyl groups, substitutions that should stabilize the proposed radical intermediate generated by decarboxylation, are present. The oxidation of 16-oxohexadecanoic acid is not supported by H2O2. The results demonstrate that aldehyde oxidation by cytochrome P450BM-3 is insensitive to changes in substrate structure expected to stabilize the transition state for decarboxylation. Decarboxylation, in contrast to the oxidation of aldehydes to acids, depends on specific substrate-protein interactions and is enzyme-specific.

Establishment and characterization of two cell lines derived from human transitional cell carcinoma

Two continuous cell lines derived from the neoplastic urothelium had been maintained in culture for more than two years. The first cell line derived from the urothelium of a fusion papillocarcinoma on the left lateral wall of the bladder was designated as TBC-1 and grown in vitro for more than 150 generations. The second cell line derived from the urothelium of a papillocarcinoma in the left renal pelvis was designated as TPC-1 and grown in vitro for more than 100 generations. Characterization studies made on both cell lines showed that the cells had a rapid doubling time, exhibited multilayering and produced tumors in sc of BALB/c. Tumor nodules that produced sc of BALB/c kept similar cellular and pathological features to those of the primary biopsy specimens under light and electron microscopes. TPC-1 cell line exhibited a three-dimensional structure of transitional epithelium on the nylon-mesh disk which was coated with a layer of rat tail collagen. Both TBC-1 and TPC-1 cell lines formed colonies in soft agar. Their forming rates were 35% and 28%, respectively. The chromosome number of TBC-1 cells ranged from 17 to 84, with a modal number of 54; whereas that of TPC-1 cells ranged from 28 to 139, with a modal number of 49. The TBC-1 cells showed mutant p53 and ras p21 protein expression and expressed weakly ABH blood group isoantigens. Analysis of lactic dehydrogenase (LDH) isozymes showed the highest levels of LDH isozyme 4 sonicated cell lysates of TBC-1 and TPC-1 respectively.

Effect of aging on the secondary esophageal peristalsis: presbyesophagus revisited

In this study we determined the effect of aging on the capability of the human esophagus to generate secondary peristalsis. We studied nine healthy young (35 +/- 2 yr, 25-45 yr) and nine healthy elderly (74 +/- 3 yr, 70-83 yr) volunteers. We stimulated secondary peristalsis by intraesophageal air injection and balloon distension. All young volunteers exhibited secondary esophageal peristalsis. In four elderly volunteers, secondary peristalsis could not be elicited with injection of any of the tested air volumes. Frequency of stimulation of secondary peristalsis and lower esophageal sphincter (LES) relaxation in response to intraesophageal air distension in the elderly was significantly lower than that in the young (P < 0.01). Stimulation of secondary peristalsis by balloon distension was less consistent compared with the air injection. In conclusion, 1) in the elderly, compared with the young, secondary esophageal peristalsis is either absent or is evoked less frequently after esophageal distension, and complete LES relaxation in response to esophageal air distension is less frequent, and 2) in both young and elderly, secondary esophageal peristalsis is induced more frequently after generalized esophageal distension by air than its segmental distension by a balloon.

Effect of aging, position, and temperature on the threshold volume triggering pharyngeal swallows

BACKGROUND/AIMS

Swallows triggered by direct stimulation of pharyngeal structures may help to prevent aspiration by emptying the pharynx. The aims of this study were to compare the biomechanical events of the pharyngeal and primary swallow, determine the threshold volume of liquid required to trigger the pharyngeal swallows, and determine the effect of aging, position, and temperature on this threshold volume.

METHODS

Concurrent manometry, video fluoroscopy, and video endoscopy were used to study young and elderly healthy volunteers.

RESULTS

During pharyngeal swallows, in contrast to primary swallows, the free portion of the tongue did not make contact with the hard palate. In addition, pharyngeal swallows did not result in oral bolus clearance. All other biomechanical events, including deglutitive glottal function, were similar in both types of swallows. The threshold volume for pharyngeal swallows in young volunteers was significantly smaller than in the elderly (P < 0.01). Temperature and position did not have significant effects on threshold volume.

CONCLUSIONS

Swallowing is readily induced by water stimulation of the pharynx. Pharyngeal swallows do not induce lingual peristalsis or clearance of oral content. The threshold volume of the pharyngeal swallow is significantly higher in the elderly than in the young, but it is not affected by body position or bolus temperature.

Effect of P-450 omega-hydroxylase metabolites of arachidonic acid on tubuloglomerular feedback

The role of endogenous P-450 metabolites of arachidonic acid (AA) on the tubuloglomerular feedback (TGF) response was examined. Under control conditions stop-flow pressure (SFP) fell by 17.0 +/- 2.1 mmHg when the perfusion rate of the loop of Henle was increased from 0 to 50 nl/min. Addition of AA (50 microM) to the perfusate lowered basal SFP by 11.4 +/- 1.1 mmHg and potentiated the TGF response. This effect was blocked by addition of a P-450 inhibitor, 17-octadecynoic acid (17-ODYA) (10 microM), to the perfusate. Perfusion of the loop of Henle with 17-ODYA elevated basal SFP by 3.7 +/- 0.3 mmHg and reduced the TGF response by 80%. After blockade of endogenous P-450 activity with 17-ODYA, addition of 20-hydroxyeicosatetraenoic acid (20-HETE, 10 microM) to the perfusate produced a flow rate-dependent fall in SFP. The effect of 20-HETE was not altered by pretreating the animal with meclofenamate (2 mg/kg iv) or by perfusing the nephron segment with furosemide (50 microM). These results indicate that endogenous P-450 metabolites of AA, particularly 20-HETE, may play a role in TGF and the regulation of renal vascular tone.

Cytochrome P-450 inhibitors alter afferent arteriolar responses to elevations in pressure

The present study evaluated the effects of cytochrome P-450 inhibitors on the response of the renal microvasculature to changes in renal perfusion pressure and on autoregulation of glomerular capillary pressure using the rat juxtamedullary nephron microvascular preparation perfused in vitro with a cell-free perfusate containing 5% albumin. The basal diameters of the proximal and distal afferent arterioles averaged 28 +/- 1 (n = 32) and 18 +/- 1 micron (n = 23), respectively, at a control perfusion pressure of 80 mmHg. The diameters of these vessels decreased by 8% when perfusion pressure was elevated from 80 to 160 mmHg. After addition of cytochrome P-450 inhibitors (either 17-octadecynoic acid, 20 microM; 7-ethoxyresorufin, 10 microM; or miconazole, 20 microM) to the perfusate, the diameters of the proximal and distal afferent arterioles increased by 6% in response to the same elevation in perfusion pressure. Control glomerular capillary pressure averaged 43 +/- 1 mmHg (n = 32) at a renal perfusion pressure of 80 mmHg and increased by only 9 +/- 1 mmHg when perfusion pressure was elevated to 160 mmHg. Autoregulation of glomerular capillary pressure was impaired after addition of the cytochrome P-450 inhibitors, and it increased by 18 +/- 2 mmHg when perfusion pressure was varied over the same range. These results indicate that cytochrome P-450 inhibitors attenuate the vasoconstrictor response of afferent arterioles to elevations in renal perfusion pressure and impair autoregulation of glomerular capillary pressure, suggesting a possible role for cytochrome P-450 metabolites of arachidonic acid in these responses.

In vitro characterization of nonpeptide irreversible inhibitors of HIV proteases

The irreversible inhibition of human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2) proteases by 1,2-epoxy-3-(p-nitrophenoxy)propane (EPNP) and eight haloperidol derivatives has been studied. EPNP specifically inhibits HIV-1 and HIV-2 proteases with a stoichiometry of one EPNP molecule/dimeric enzyme. The site of modification of HIV-2 protease by EPNP has been unambiguously identified as Asp-25 using high performance tandem mass spectrometry. The haloperidol derivatives assayed consist of epoxides, ynones, and alpha,beta-unsaturated ketones. The Kinact values for these haloperidol derivatives range from 10.7 to 521 microM for HIV-1 protease and from 8.6 to 283 microM for the HIV-2 enzyme, being in some cases approximately 1000-fold more potent irreverisble inhibitors of HIV proteases than EPNP. This potency results from the haloperidol character of the compounds and the chemical reactivity of the groups capable of forming a covalent bond with the enzyme. Covalent modification of HIV-2 protease by a radiolabeled epoxide derivative of haloperidol, UCSF 84, is prevented by EPNP and the peptidomimetic transition state analog U-85548. In similar experiments, incorporation of UCSF 84 into HIV-1 protease is partially prevented by these active-site inhibitors. In contrast, a mutant HIV-1 protease, HIV-1 PR C95M, in which Cys-95 has been replaced by Met, is labeled 50% less than HIV-1 protease and is fully protected by EPNP and U-85548. These results indicate the presence of 2 reactive residues in HIV-1 protease: Cys-95 and another located in the active site of the enzyme. The alpha,beta-unsaturated ketone derivative of haloperidol, UCSF 191, which is stable over a broad pH range, was used to study the pH profile of inactivation of HIV-1 and HIV-2 proteases. Comparison of the profiles of inactivation of wild-type HIV-1 protease, HIV-1 PR C95M, and HIV-1 PR C67L as well as HIV-2 protease (which has no cysteine residues) reveals the contribution of Cys-95 to the reactivity of these irreversible inhibitors. The inhibitors UCSF 70, UCSF 84, UCSF 115, UCSF 142, and UCSF 191 reduce p55gag polyprotein processing when assayed in a mammalian cell line that produces HIV-1 viral particles lacking the envelope.

Haloperidol-based irreversible inhibitors of the HIV-1 and HIV-2 proteases

The proteases expressed by the HIV-1 and HIV-2 viruses process the polyproteins encoded by the viral genomes into the mature proteins required for virion replication and assembly. Eight analogs of haloperidol have been synthesized that cause time-dependent inactivation of the HIV-1 protease and, in six cases, HIV-2 protease. The IC50 values for the analogues are comparable to that of haloperidol itself. Enzyme inactivation is due to the presence of an epoxide in two of the analogues and carbonyl-conjugated double or triple bonds in the others. Irreversible inactivation is confirmed by the failure to recover activity when one of the inhibitors is removed from the medium. At pH 8.0, the agents inactivate the HIV-1 protease 4-80 times more rapidly than the HIV-2 protease. Faster inactivation of the HIV-1 protease is consistent with alkylation of cysteine residues because the HIV-1 protease has four such residues whereas the HIV-2 protease has none. Inactivation of the HIV-2 protease requires modification of non-cysteine residues. The similarities in the rates of inactivation of the HIV-2 protease by six agents that have intrinsically different reactivities toward nucleophiles suggest that the rate-limiting step in the inactivation process is not the alkylation reaction itself. At least five of the agents inhibit polyprotein processing in an ex vivo cell assay system, but they are also toxic to the cells.

Inhibition of renal vascular 20-HETE production impairs autoregulation of renal blood flow

The present study evaluated the role of endogenous P-450 metabolites of arachidonic acid (AA) on autoregulation of renal blood flow in rats. Whole kidney and cortical blood flows were well autoregulated when renal perfusion pressure was varied from 150 to 100 mmHg. Infusion of 17-octadecynoic acid (17-ODYA) into the renal artery (33 nmol/min) increased cortical and papillary blood flows by 12.6 +/- 2.5 and 26.5 +/- 4.6%, respectively. After 17-ODYA, autoregulation of whole kidney and cortical blood flows was impaired. Intrarenal infusion of miconazole (8 nmol/min) had no effect on autoregulation of whole kidney, cortical, or papillary blood flows. 17-ODYA (1 microM) inhibited the formation of 20-hydroxyeicosatetraenoic acid (20-HETE) and 11,12- and 14,15-epoxyeicosatrienoic acids (EETs) by renal preglomerular microvessels in vitro by 83.7 +/- 7.4% and 89.0 +/- 4.9%, respectively. Miconazole (1 microM) reduced the formation of EETs by 86.4 +/- 5.7%, but it had no effect on the production of 20-HETE. These results suggest that endogenous P-450 metabolites of AA, particularly 20-HETE, may participate in the autoregulation of renal blood flow.

Regulation of pathways of extramitochondrial fatty acid oxidation and liver fatty acid-binding protein by long-chain monocarboxylic fatty acids in hepatocytes. Effect of inhibition of carnitine palmitoyltransferase I

The regulation of the extramitochondrial fatty acid oxidation pathways located in the peroxisomes and the endoplasmic reticulum is not fully understood. Although both long-chain dicarboxylic fatty acids, which are poorly metabolized in hepatocytes, and non-beta-oxidizable fatty acid analogs induce peroxisomal beta-oxidation and liver fatty acid-binding protein (L-FABP) by a pretranslational mechanism, monocarboxylic long-chain fatty acids, which are rapidly esterified and oxidized, do not. To establish whether impaired utilization and, hence, sustained intracellular levels of monocarboxylic long-chain fatty acids increase their efficacy as inducers, the effect of oleic acid on cytochrome P-450 4A1, peroxisomal beta-oxidation, and L-FABP during inhibition of mitochondrial beta-oxidation was determined. In primary hepatocyte cultures, oleic acid had no inducing effect, but in the presence of 2-tetradecylglycidic acid (TDGA), an inhibitor of carnitine palmitoyltransferase I, it induced P-450 4A1, peroxisomal beta-oxidation, and L-FABP pretranslationally. An increase in peroxisomal beta-oxidation was also noted in the presence of etomoxir, another inhibitor of carnitine palmitoyltransferase I. Exposure of hepatocytes to TDGA for 1 h led to an expected decrease in incorporation of radiolabel from [1-14C]oleate into CO2 and water-soluble products. In contrast, long-term exposure to TDGA increased incorporation of [1-14C]oleate into oxidation products, most likely due to an adaptive induction of peroxisomal beta-oxidation. Both acute and long-term exposure of hepatocytes to TDGA decreased incorporation of oleic acid into triglycerides, an effect that may have contributed to the intracellular accumulation of fatty acids. These results provide support for a mechanism by which long-chain fatty acids or specific metabolites, including long-chain acyl-CoA esters and long-chain dicarboxylic acids, act as signals in the induction of P-450 4A1, peroxisomal beta-oxidation, and L-FABP under conditions in which long-chain fatty acids accumulate due to impaired entry into the mitochondrial beta-oxidation pathway.

Cytochrome P450BM-3 (CYP102): regiospecificity of oxidation of omega-unsaturated fatty acids and mechanism-based inactivation

Cytochrome P450BM-3 preferentially oxidized fatty acids with terminal double or triple bonds to the omega-2 hydroxylated fatty acids rather than, respectively, to the epoxide or diacid metabolites. The enzyme is inactivated during catalytic turnover of long, terminally unsaturated fatty acids but not by the analogous medium-length fatty acids. Enzyme inactivation by 17-octadecynoic acid and 16-hydroxy-17-octadecynoic acid is due to alkylation of the prosthetic heme group to given an adduct tentatively identified as N-(2-oxo-3-hydroxy-17-carboxyheptadecyl)protoporphyrin IX by its chromatographic and spectroscopic properties. Catalytic turnover of 17-octadecenoic acid also results in heme modification. Fatty diacid monoethyl thioesters are introduced as a new class of irreversible inhibitors that exploit the omega-2 oxidation specificity of cytochrome P450BM-3. Catalytic oxidation of the monoethyl thioesters of dodecanedioic and hexadecanedioic acids results in enzyme inactivation and formation of the parent diacids as metabolites. Limited tryptic digestion of the enzyme after incubation with the monoethyl thioester of [14C]hexadecanedioic acid shows that the inactivating agent binds covalently to both the heme and flavin domains. This finding, and the observation that glutathione prevents inactivation of the enzyme by the monoethyl thioesters, indicate that a diffusible metabolite, probably the sulfoxide, is responsible for enzyme inactivation. The strong preference for omega-2 allylic or propargylic hydroxylation over terminal pi-bond oxidation is opposite to the usual cytochrome P450 pattern and requires that the enzyme actively suppress terminal pi-bond oxidation. The inference that the enzyme binds and sequesters the terminal carbon in a lipophilic pocket is consistent with the crystal structure of the hemoprotein domain of cytochrome P450BM-3.

Inhibition of the HIV-1 and HIV-2 proteases by curcumin and curcumin boron complexes

Curcumin, a relatively non-toxic natural product isolated from Curcuma longa, is a modest inhibitor of the HIV-1 (IC50 = 100 microM) and HIV-2 (IC50 = 250 microM) proteases. Simple modifications of the curcumin structure raise the IC50 value but complexes of the central dihydroxy groups of curcumin with boron lower the IC50 to a value as low as 6 microM. The boron complexes are also time-dependent inactivators of the HIV proteases. The increased affinity of the boron complexes may reflect binding of the orthogonal domains of the inhibitor in interesecting sites within the substrate-binding cavity of the enzyme, while activation of the alpha, beta-unsaturated carbonyl group of curcumin by chelation to boron probably accounts for time-dependent inhibition of the enzyme.

Determinants of protein modification versus heme alkylation: inactivation of cytochrome P450 1A1 by 1-ethynylpyrene and phenylacetylene

Reaction of cytochrome P450 enzymes with arylacetylenes results in heme N-alkylation [e.g., Komives, E. A., and Ortiz de Montellano, P. R., (1985) J. Biol. Chem. 260, 3330-3336] and/or protein modification [e.g., Gan, L.-S. L., Acebo, A. L. and Alworth, W. L. (1984) Biochemistry 23, 3827-3836]. To clarify the factors that determine whether heme or protein alkylation occurs, we have investigated the cytochrome P450 1A1-catalyzed oxidation of 1-ethynylpyrene (1-EP) and phenylacetylene (PA). Cytochrome P450 1A1 in microsomes from beta-naphthoflavone-induced rats is inactivated in a time- and NADPH-dependent manner by 1-EP and PA. Parallel loss of the heme chromophore is observed with PA but not with 1-EP, although partial heme chromophore loss is observed when the purified, reconstituted enzyme is inactivated by either agent. Product analysis shows that 1-EP and PA are oxidized to, respectively, (1'-pyrenyl)-acetic and phenylacetic acids. In contrast to the inactivation of cytochrome P450 2B1 by PA, no isotope effect is observed on enzyme inactivation or metabolite formation when the acetylenic hydrogen is replaced by deuterium in either 1-EP or PA. Inactivation of cytochrome P450 1A1 by 1-EP results in covalent binding of 0.8-0.9 equiv (relative to total cytochrome P450 content) of the inhibitor to the microsomal protein. The results demonstrate that a single isozyme can be inactivated, depending on the structure of the arylacetylene, by heme or protein alkylation. Spectroscopic binding constants (Ks) show that 1-EP binds to the enzyme with > 2000 times greater affinity that PA.(ABSTRACT TRUNCATED AT 250 WORDS)

[The relationship between carbon monoxide poisoning and meteorological conditions in Baishan district]

This article analysis the meteorological data during the outbreaks of carbon monoxide poisoning and the conditions of 108 poisoned people in Baishan District from Oct., 1980 to Feb., 1985. The results showed that most of the poisoning cases happened in the months of the lowest air temperature. The main factors affecting poisoning were season, wind direction, raifall and atmospheric pressure, of secondary importance were air temperature and humidity. The time when CO poisoning most easily took place when the night was without wind, accompanied by snowfall or rainfall. The atmospheric pressure value was lower than average month value, and the humidity higher than average month value. The writer proposes to use the "average month value" method for forecasting "similar date" method.