Nuclear import of the pre-integration complex (PIC): the Achilles heel of HIV?

Current treatments against the Aquired immune deficiency syndrome (AIDS) are reasonably effective in reducing the amount of human immunodeficiency virus (HIV) present in infected patients, but their side-effects, and the emergence of drug-resistant HIV strains have intensified the renewed search for novel anti-HIV therapies. An essential step in HIV infection is the integration of the viral genome into the host cell chromosomes within the nucleus. Unlike other retroviruses, HIV can transport its genetic material, in the form of the large nucleoprotein pre-integration complex (PIC), into the nucleus through the intact nuclear envelope (NE). This enables HIV to infect non-dividing cells such as macrophages and microglial cells. Detailed knowledge of the signal-dependent pathways by which cellular proteins and RNAs cross the NE has accumulated in the past decade, but although several different components of the PIC have been implicated in its nuclear import, the mechanism of nuclear entry remains unclear. Since specifically inhibiting PIC nuclear import would undoubtedly block HIV infection in non-dividing cells, this critical step of HIV replication is of great interest as a drug target. This review examines the complex and controversial literature regarding three PIC components--the HIV proteins matrix, integrase and Vpr--proposed to facilitate PIC nuclear import, and existing models of HIV PIC nuclear import. It also suggests approaches to move towards a better understanding of PIC nuclear import, through examining the role of individual PIC components in the context of the intact PIC by direct visualisation, in order to develop new anti-HIV therapeutics.     

Population pharmacokinetics of S(−)-carvedilol in healthy volunteers after administration of the immediate-release (IR) and the new controlled-release (CR) dosage forms of the racemate

Carvedilol is a beta(1)-, beta(2)-, and alpha(1)-adrenoreceptor blocker indicated for treatment of hypertension and mild-to-severe congestive heart failure. The objective of this study was to develop and evaluate a single population model that describes S(-)-carvedilol pharmacokinetics from both the immediate-release (IR) and the new controlled-release dosage forms of the racemate. Carvedilol IR data (1270 measurements) were obtained from 2 open-label studies (50 mg/25 mg Q12 hours for 2 doses). Carvedilol CR data (2058 measurements) were obtained from an open-label, nonrandomized, dose-rising (10, 20, 40, and 80 mg), 4-period balanced crossover study. All data were simultaneously analyzed using NONMEM V. Leverage analysis and internal evaluations were conducted for the final model. A 2-compartment model with first-order absorption and elimination provided the best fit. The model included different absorption rates (KAs) for the CR and IR morning (IR(AM)) and evening (IR(PM)) doses; incorporating change-points at certain times. Estimates of KAs indicated that the absorption was slower at equivalent times and extended for CR relative to IR carvedilol. Oral clearance of S(-)-carvedilol was 149 L/h. The IR(PM) and the CR doses had bioavailability (F(rel)) of 0.80 and 0.76, respectively, relative to the IR(AM) dose. The inter-subject variability in KAs was lower for the CR dosage form than the original IR dosage form. Estimation of interoccasion variability on KAs and F(rel) for the CR dosage form improved the fit. The model performed well in simulation and leverage analysis indicated its robustness. The model will be a useful tool for future simulation studies.     

Alkaloids from the Roots of Aristolochia Triangularis(I)

从马兜铃科植物Ａｒｉｓｔｏｌｏｃｈｉａｔｒｉａｎｇｕｌａｒｉｓ的根部分离出十五个生物碱成分。其中两种成分ｔｒｉａｎｇｕｌａｒｉｎｅ－Ａ和ｔｒｉａｎｇｕｌａｒｉｎｅ－Ｂ系新生物碱，三种系阿卟啡类季铵碱。这些化合物的结构经各种波谱（ＩＲ，ＵＶ，ＭＳ，２ＤＮＭＲ）解析和化学转化技术得以确定。     

Evaluation of the efficacy of dicyclomine hydrochloride (‘Merbentyl’) syrup in the treatment of infant colic

Summary

A double-blind crossover trial was carried out in 25 babies with infant colic to compare the symptomatic relief provided by dicyclomine hydrochloride (5mg4-times daily) or placebo. Patients received each treatment, in random order, for 1 week. A scoring system was used to measure the total symptom complex as well as the individual parameters of post-prandial crying, post-prandial vomiting, and sleep disturbance. Dicyclomine hydrochloride syrup was found to be superior to placebo in relieving the total symptom complex (p < 0.025) and in reducing sleep disturbance (p < 0.05). Side-effects with both therapies were minimal.     

Comparison of the rat liver microsomal metabolism of the enantiomers of warfarin and 4′-nitrowarfarin (Acenocoumarol)

1. Rat liver microsomal metabolism of the enantiomers of warfarin and acenocoumarol (4′-nitrowarfarin) has been studied. The enantiomers of both compounds were hydroxylated mainly at the 6- and 7-positions. Acenocoumarol enantiomers were much better substrates for cytochromes P-450 than the corresponding warfarin enantiomers; K_m values for the 6- and 7-hydroxylations were 2 to 19 times lower for R- and S-acenocoumarol than for warfarin.

2. Formation of the 6-, 7-, and 8-hydroxy-metabolites of warfarin was stereoselective for the R-enantiomer (the R/S ratio for total intrinsic clearance was about 3). 4′-Hydroxylation was not stereoselective. In contrast, formation of acenocoumarol metabolites was stereoselective for the S-enantiomer (the S/R ratio for total intrinsic clearance was about 3).

3. From the effects of phenobarbitone and methylcholanthrene induction, and inhibition by cimetidine, on in vitro metabolism of the enantiomers of both compounds, it was concluded that the differences between warfarin and acenocoumarol can be explained partly by the involvement of different enzymes.     

Advances in the study of drug metabolism – symposium report of the 12th Meeting of the International Society for the Study of Xenobiotics (ISSX)

Abstract

The 12th International Society for the Study of Xenobiotics (ISSX) meeting, held in Portland, OR, USA from July 28 to 31, 2019, was attended by diverse members of the pharmaceutical sciences community. The ISSX New Investigators Group provides learning and professional growth opportunities for student and early career members of ISSX. To share meeting content with those who were unable to attend, the ISSX New Investigators herein elected to highlight the “Advances in the Study of Drug Metabolism” symposium, as it engaged attendees with diverse backgrounds. This session covered a wide range of current topics in drug metabolism research including predicting sites and routes of metabolism, metabolite identification, ligand docking, and medicinal and natural products chemistry, and highlighted approaches complemented by computational modeling. In silico tools have been increasingly applied in both academic and industrial settings, alongside traditional and evolving in vitro techniques, to strengthen and streamline pharmaceutical research. Approaches such as quantum mechanics simulations facilitate understanding of reaction energetics toward prediction of routes and sites of drug metabolism. Furthermore, in tandem with crystallographic and orthogonal wet lab techniques for structural validation of drug metabolizing enzymes, in silico models can aid understanding of substrate recognition by particular enzymes, identify metabolic soft spots and predict toxic metabolites for improved molecular design. Of note, integration of chemical synthesis and biosynthesis using natural products remains an important approach for identifying new chemical scaffolds in drug discovery. These subjects, compiled by the symposium organizers, presenters, and the ISSX New Investigators Group, are discussed in this review.     

Comparison of dynamics of extracellular accesses to the β(1) and β(2) adrenoceptors binding sites uncovers the potential of kinetic basis of antagonist selectivity

From the molecular mechanism of antagonist unbinding in the β(1) and β(2) adrenoceptors investigated by steered molecular dynamics, we attempt to provide further possibilities of ligand subtype and subspecies selectivity. We have simulated unbinding of β(1)-selective Esmolol and β(2)-selective ICI-118551 from both receptors to the extracellular environment and found distinct molecular features of unbinding. By calculating work profiles, we show different preference in antagonist unbinding pathways between the receptors, in particular, perpendicular to the membrane pathway is favourable in the β(1) adrenoceptor, whereas the lateral pathway involving helices 5, 6 and 7 is preferable in the β(2) adrenoceptor. The estimated free energy change of unbinding based on the preferable pathway correlates with the experimental ligand selectivity. We then show that the non-conserved K347 (6.58) appears to facilitate in guiding Esmolol to the extracellular surface via hydrogen bonds in the β(1) adrenoceptor. In contrast, hydrophobic and aromatic interactions dominate in driving ICI-118551 through the easiest pathway in the β(2) adrenoceptor. We show how our study can stimulate design of selective antagonists and discuss other possible molecular reasons of ligand selectivity, involving sequential binding of agonists and glycosylation of the receptor extracellular surface.     

Contribution of the β-ureidopropionase (UPB1) gene alterations to the development of fluoropyrimidine-related toxicity

BackgroundAn impairment of the 5-fluorouracil (5-FU) catabolic pathway, represented by alterations in the dihydropyrimidine dehydrogenase (DPYD) gene, is considered a crucial factor contributing to the development of 5-FU-related toxicity. The β-ureidopropionase (BUP1) enzyme catalyzes the final step in the 5-FU catabolic pathway; however, alterations in the UPB1 gene coding for the BUP1 enzyme have not yet been analyzed in fluoropyrimidine (FP)-treated patients suffering from 5-FU-related toxicity.MethodsWe have performed a mutation analysis of the entire coding sequence of UPB1 based on denaturing high-performance liquid chromatography in 113 cancer patients treated by FP-containing regimes. These patients included 67 individuals suffering from severe 5-FU-related toxicity and 46 individuals with excellent tolerance of chemotherapy.ResultsNine UPB1 variants were detected in the subpopulation of patients with severe toxicity, including a novel mutation affecting the coding sequence (c.872_873 + 11del13). An analysis of UPB1 variants on 5-FU-related toxicity in the population of all analyzed patients revealed an association between the c.-80C > G (rs2070474) variant and gastrointestinal toxicity. A strong positive correlation was found between the carriers of the c.-80 GG genotype and the development of severe (grade 3–4) mucositis (OR = 7.5; 95% CI = 2.60 – 21.60; p = 0.0002).ConclusionOur results suggest that UPB1 variants may contribute to the development of 5-FU-related toxicity in some FP-treated patients; however, the role of UPB1 alterations is probably less significant than that of DPYD alterations.     

Section 3 An evaluation of the anti- inflammatory effects of iduprofen (‘Brilfen’) in osteoarthrosis of the knee using radioactive technetium (99mTc)

Summary

The anti-inflammatory activity of ibuprofen {1200?mg. daily) was studied in a small group of patients {10) with osteoarthrosis of the knee using the technique of ^99mTc joint uptake. Assessments were carried out before and at approximately 2-monthly intervals over the 6-month period of treatment. Analysis of the scans confirmed the clinical observations, and good results were obtained in 3 and very good results in 7 of the 10 patients.     

Thermodynamic Study of Sulfanilamide Polymorphism: (I) Monotropy of the α-Variety

Purpose. Sulfanilamide was chosen as a model compound in order to gain insights on the stability hierarchy of drug polymorphs from structural and thermodynamic criteria. Despite numerous studies, disagreements remained on the reported enthalpies associated with the mutual interconvertions of the -, -, and -forms of sulfanilamide. Therefore, the unambiguous determination of these enthalpies was the purpose of this work. Methods. Samples, free of solvent inclusions and made of only one form, were prepared, and analyzed combining X-ray powder diffraction and Differential Scanning Calorimetry (DSC). Results. The enthalpy values associated with the - to - and - to -transitions were found to be + 10.2 and + 10.9 J g^–1, respectively. The calculated enthalpy of the - to -transition is consistent with the experimental one ( + 1 J g^–1). Conclusions. The monotropy of the -form was ascertained over the explored temperature range at ordinary pressure.     

Antihyperglycaemic potential of the water–ethanol extract of Kalanchoe crenata (Crassulaceae)

Kalanchoe crenata is a vegetable widely used in Cameroon and largely efficient in the treatment of diabetes mellitus. The effect of the water–ethanol extract of this plant (WEKC) on blood glucose levels was investigated in fasting normal and diet-induced diabetic rats (MACAPOS 1) after a short- and medium-term treatment. Diabetes was induced by submitting Wistar rats to a hypercaloric sucrose diet over 4 months. Six hours after a single oral administration of WEKC, 135 and 200 mg kg⁻¹ body weight extracts significantly (P < 0.01) reduced the blood glucose levels both in normal and diabetic rats without real dose-dependant effect. During the medium-term treatment, 200 mg kg⁻¹ WEKC administered daily for 4 weeks significantly reduced blood glucose levels within week 1 (P < 0.05), with a maximum effect at week 4 (−52%, P < 0.01), while maintaining glycaemia within the normal range. All the WEKC-treated diabetic rats exhibited significant (P < 0.01) increase in insulin sensitivity index (K _ITT) compared with the initial time and to the untreated diabetic animals. Animals treated for 4 weeks exhibited a slight resistance in body-weight gain and decrease in food and water intake. The WEKC activities on all parameters assessed were comparable with the glibenclamide effects. Qualitative phytochemical screening revealed that K. crenata contains terpenoids, tannins, polysaccharids, saponins, flavonoids and alkaloids. The data suggest that K. crenata might contain important chemical components that could induce significant improvement in glucose clearance and/or uptake and resistance to body-weight gain and insulin sensitivity, and could be a potent alternative or complementary therapeutic substance in the control of type 2 diabetes and other insulin-resistant conditions.     

Lead optimization of 17β-HSD1 inhibitors of the (hydroxyphenyl)naphthol sulfonamide type for the treatment of endometriosis

The reduction of estrone to estradiol, the most potent estrogen in human, is catalyzed by 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1). A promising approach for the treatment of estrogen-dependent diseases is the reduction of intracellular estradiol formation by inhibition of 17β-HSD1. For the species-specific optimization of the (hydroxyphenyl)naphthols, a combinatorial approach was applied and enhanced by a focused synthesis that resulted in the aromatic-substituted (hydroxyphenyl)naphthol sulfonamides. Rigidification of 12 led to the 4-indolylsulfonamide 30, which is a highly active and selective human 17β-HSD1 inhibitor, as well as a highly potent and selective inhibitor of 17β-HSD1 from Callithrix jacchus. It shows no affinity to the estrogen receptors α and β and good intracellular activity (T47D). Thus, compound 30 shows good properties for further ADMET studies and might be a candidate for the in vivo proof of concept in C. jacchus.     

Characterization of the self assembly of methoxy poly(ethylene oxide)-block-poly(α-benzyl carboxylate-ε-caprolactone) for the solubilization and in vivo delivery of valspodar

The aim of this study was to characterize the nanostructures formed from assembly of poly(ethylene oxide)-bpoly( α-benzyl carboxylate ε-caprolactone) (PEO-b-PBCL) in water, determine the effect of weight fraction of the hydrophilic block( fEO) on their morphology, and to investigate their potential for solubilization and delivery of P-glycoprotein (P-gp) inhibitor, valspodar. Three PEO-b-PBCL block copolymers having fEO ranging from 0.18-0.40 were synthesized. Assembly of PEO-b-PBCL was triggered through a co-solvent evaporation method. The average critical aggregation concentration (CAC) for PEO114-b-PBCL??, PEO???-b-PBCL??, and PEO???-b-PBCL?? was found to be 62, 41, and 23 nM, respectively. A lower rigidity of the hydrophobic domain in nanostructures formed from the assembly of PEO???-b- PBCL?? and PEO???-b-PBCL?? in comparison to PEO???-b-PBCL?? was observed. The morphology of the assembled structures was characterized by transmission electron microscopy (TEM). The TEM images of PEO???-b-PBCL?? (fEO = 0.40) showed the formation of spherical micelles with high polydispersity, whereas the assembly of PEO???-b-PBCL?? (fEO = 0.25) and PEO???-b-PBCL95 (fEO = 0.18) resulted in a mixed population of spherical micelles and vesicles. Valspodar achieved high loading in all the three PEO-b-PBCL nanocarriers reaching aqueous solubility of nearly 2 mg/mL. The morphology of PEO-b-PBCL carrier did not seem to influence the pharmacokinetics of the encapsulated valspodar in rats following intravenous administration. In conclusion, the results show a potential for PEO-b-PBCL nanocarriers as efficient solubilizing agents for delivery of valspodar.     

α-adrenoceptors mediating the positive inotropic effect of phenylephrine in the right ventricular muscle of the monkey (Macaca fuscata)

Summary The property of adrenoceptors mediating the positive inotropic effect (PIE) in the ventricular muscle of the Japanese monkey (Macaca fuscata) was investigated by the use of phenylephrine (PE) and adrenoceptor antagonists. The intrinsic activity (0.6) and the pD₂-value (5.41) for PE were comparable to those in other mammalian species. The -adrenoceptor antagonist, pindolol (3×10^–8 mol/l) shifted only the upper part of the concentration-response curve (CRC) for PE to the right; the pD₂-value for PE was not significantly affected by pindolol. On the other hand, phentolamine (10^–6 mol/l) shifted the lower part of the CRC for PE more than the upper part. In the presence of both pindolol and phentolamine the curve was shifted to the right in a parallel manner. The time required for twitch relaxation was negatively correlated to the degree of PIE of PE in the presence of phentolamine but not pindolol. These results indicate that both - and -adrenoceptors mediate the positive inotropic action in the ventricular muscle of the Japanese monkey and that in contrast to the action via -adrenoceptors the action via -adrenoceptors is not accompanied by the relaxant effect.     

An analysis of theα-adrenoceptor modulation of vasomotor tone at the level of lateral medullary pressor area (LMPA)

Summary Microinjection of noradrenaline and clonidine into lateral medullary pressor area (LMPA) of chloralose anaesthetized cats produced dose dependent decrease in blood pressure without affecting heart rate, while phenylephrine did not elicit any cardiovascular response. Selective ₂-adrenoceptor, antagonists idazoxan and piperoxan, microinjected locally, blocked the effects of the agonists but prazosin and phenoxybenzamine, which are relatively selective for ₁-adrenoceptors, failed to do so. Clonidine did not elicit any response in guanethidine pretreated cats but noradrenaline microinjected into LMPA of these animals induced a pressor response which was blocked by prazosin pretreatment. It is concluded that catecholaminergic fibres impinging upon this are inhibit the activity of the inhibitory second order baroreceptor neurone by activating ₁-adrenoceptors while ₂-adrenoceptors situated presynaptically on these inhibitory catecholaminergic nerve terminals are responsible for the manifestation of the hypotensive effect of clonidine and exogenously administered noradrenaline.     

Subeffective doses of nitroparacetamol (NCX-701) enhance the antinociceptive activity of the α₂-adrenoceptor agonist medetomidine

The α₂-adrenergic system is involved in pain processing and inflammation-induced sensitization. α₂-adrenoceptor agonists induce analgesia, and this effect is greater when administered in combination with other analgesics. In the present study, we assessed a possible enhancement of antinociception combining the α₂-adrenoceptor agonist medetomidine with subeffective doses of NCX701 (nitroparacetamol). The effects of the drugs were studied in spinal cord neuronal responses from adult male Wistar rats with carrageenan-induced inflammation, using the recording of single motor unit technique. The experiments showed that the i.v. administration of medetomidine and NCX701 induced a more potent and effective antinociceptive effect than medetomidine when given alone (ID₅₀: 0.47 ± 0.1 vs. 1.1 ± 0.1 μg/kg) or in the presence of paracetamol, in naturally-evoked nociceptive responses. In addition, the duration of antinociception was significantly longer (P < 0.001, 100 min after administration). The use of low doses of NCX701 and α₂-adrenoceptor agonists might open new perspectives in the treatment of inflammatory pain.     

Investigation of the antiviral activity of copper(II) salts with α-amino acids

The search for active antiviral preparations for the treatment of a number of diseases of viral etiology, especially those for which there are no reliable means of specific prophylaxis or the pathogen possesses wide antigenic variability, is of great importance for modern medicine and veterinary science. In view of this, we investigated original compounds — copper salts of -amino acids — and studied their action on RNA- and DNA-containing animal viruses.Translated from Khimiko-farmatsevticheskii Zhurnal, Vol. 17, No. 5, pp. 565–566, May, 1983.