[Drug resistance and molecular typing of diarrheagenic escherichia coli from the diarrhea clinics in Qingpu District, Shanghai City from 2015 to 2019]

Objective: To analyze the drug resistance and multilocus sequence typing of five types of diarrheagenic Escherichia coli (DEC) isolated from diarrhea outpatients of diarrhea comprehensive monitoring designated hospital in Qingpu District, Shanghai City from 2015 to 2019. Methods: From January 2015 to December 2019, five types of DEC, isolated and identified from diarrhea outpatient cases' anal swabs of the Qingpu branch of Zhongshan Hospital were collected to determine the minimal inhibitory concentration by using the micro broth dilution susceptibility test. The strains, resistant to the third-generation cephalosporins or carbapenems, or producing ESBLs, were selected based on the results of sensitivity tests and determined by WGS. The MLST typing of DEC was analyzed based on the WGS technology and the minimum spanning tree was constructed by BioNumerics 7.6 software to analyze the local dominant flora. Results: A total of 513 strains of DEC were detected and isolated from 4 494 anal swabs, with a detection rate of 11.42%. About 500 strains were tested for drug sensitivity to nine antibiotics in four classes, including 330 strains of enterotoxigenic E.coli (ETEC), 72 strains of enteroaggregative E.coli (EAEC), 95 strains of enteropathogenic E.coli (EPEC), 1 strain of enterohemorrhagic E.coli (EHEC), and 2 strains of enteroinvasive E.coli (EIEC). From 2015 to 2019, the resistance rate of cefotaxime-clavulanic acid was significantly different (P<0.05). The resistance rate of virulence types of DEC to nalixic acid was significantly different (P<0.05). About 71 strains of DEC were determined by WGS, and 77 drug-resistant genes were detected. Strains were classified into 32 ST subtypes, with the dominant genotypes being ST-1491 (29.6%, 21/71) and ST-10 Complex (23.9%, 17/71). All ST-1491 produced ESBLs, which were blaCTX-M gene mutant strains. The dominant type of ST-10 complex was ST-218 (35.3%, 6/17). In addition, 8 strains of EAEC, 14 strains of EPEC and 49 strains of ETEC were classified into 7, 14 and 18 ST subtypes, respectively. Conclusion: The drug resistance of DEC strains from the diarrhea outpatient case of Qingpu District is serious. The ST types of EAEC and EPEC are highly polymorphic. The dominant ST types of DEC are basically consistent with the common genotypes in southeast China.

[Drug selection for simultaneous treatment of tuberculosis combined with hepatitis C virus infection]

Clinically, patients with tuberculosis (TB) combined with hepatitis C virus (HCV) infection often require simultaneous treatment. Consequently, when anti-HCV and TB drugs are used in combination drug-drug interactions (DDIs), anti-TB drug-induced hepatotoxicity, and liver disease states need to be considered. This paper focuses on discussing the metabolic mechanisms of commonly used anti-TB and HCV drugs and the selection options of combined drugs, so as to provide rational drug use for TB patients combined with HCV infection.

[Analysis of eight-year follow-up data of plateau workers by color doppler echocardiography]

Objective: To analyze the heart rate changes and risk factors, as a result of high altitude. Methods: Retrospective analysis of echocardiographic data of plateau workers at a railway maintenance company from 2006 to 2013. The survival curve method was used to analyze the abnormal rate of the heart. Kaplan-Meier method and Cox proportional hazards regression model were used to analyze the influencing factors. Results: In the first occurrence of cardiac abnormalities, the main types of abnormalities were right atrium enlargement (53.47%) , right ventricle enlargement (17.36%) , and tricuspid regurgitation (16.67%) . Cox regression analysis showed that workplace altitude and first physical examination age are two influencing factors of cardiac abnormalities, and their relative risk was 1.661 and 1.039. At high altitudes (3 600~4 000 m) , nearly 40% of workers heart has not changed. But this adaptation does not observed in the ultra-high altitudes (≥4 000 m) . Conclusion: There are individual differences in human adaptability to high altitude. We should take more stringent measures of health care for older people and those who work at more than 4000m. And we should abide by the rotation system for railways that are suitable for the plateau.

[Recovery of hemoglobin level and blood pressure in workers unfit for duties at high altitude following relocation]

Objective: To determine the hemoglobin level and blood pressure and the factors that influence their recovery in relocated workers who were unfit for duties at high altitude. Methods: The physical examination data of 693 relocated workers who previously worked at high altitude were dynamically monitored from January 2006 to June 2015 in order to examine the recovery of hemoglobin level and blood pressure. Results: The rate of hemoglobin recovery was 81.37% among the 161 relocated workers with abnormal hemoglobin levels, and the rate of blood pressure recovery was 69.51% among the 164 relocated workers with abnormal blood pressure. The rates of hemoglobin and blood pressure recovery were decreased in individuals aged 40 years and older. The peak recovery time of hemoglobin was 11-15 months following relocation, and that of blood pressure was 5-7 months and 11-13 months following relocation. The half-year blood pressure recovery rate and 2-year hemoglobin recovery rate following relocation were significantly higher in workers who worked at 2500-3000 m altitude than in those at ≥3000 m (P<0.05) . Total cholesterol and educational level were factors that influence the half-year blood pressure recovery in relocated workers (P<0.05) . Conclusion: The rate of hemoglobin and blood pressure recovery are high among relocated workers who previously worked at high altitude. Factors that influence blood pressure, such as total cholesterol, should be closely monitored so that high-altitude workers with abnormal blood pressure and hemoglobin level can be relocated as early as possible.

[Research advances in the role of interleukin-21 in chronic hepatitis B virus infection]

Interleukin-21 (IL-21) is a cytokine mainly secreted by activated CD4+ T cells and natural killer T cells and has multiple effects. It is involved in innate and adaptive immune responses. Recent studies have shown that IL-21 can promote functional activation of various immune cells in the process of hepatitis B virus (HBV) infection, and the gene polymorphisms of IL-21 is associated with the susceptibility to HBV. In addition, the expression of IL-21 is closely associated with HV genotype, HBV clearance, HBeAg seroconversion, HBV-related liver cirrhosis, liver failure, liver cancer, and autoimmune disease. This article reviews the research advances in clinical trials with reference to the aspects above.

Effect of anchoring 4-anilidopiperidines to opioid peptides

We report here the design, synthesis, and in vitro characterization of new opioid peptides featuring a 4-anilidopiperidine moiety. Despite the fact that the chemical structures of fentanyl surrogates have been found suboptimal per se for the opioid activity, the corresponding conjugates with opioid peptides displayed potent opioid activity. These studies shed an instructive light on the strategies and potential therapeutic values of anchoring the 4-anilidopiperidine scaffold to different classes of opioid peptides.

Molecular epidemiological features of Mycobacterium tuberculosis in an endemic region of Henan Province, China

Henan Province is one of the regions with the highest tuberculosis (TB) burden in China. Among isolates collected from Zhongmou County, Henan, 21.28% (10/47) of those from 2001 and 22.95% (10/61) from 2007 were resistant to at least one drug (isoniazid, rifampicin, ethambutol or streptomycin); 90.74% (98/108) of the isolates were from the Beijing family, and 108 exhibited 105 different mycobacterial interspersed repetitive units-variable number of tandem repeats patterns. This study preliminarily reveals that Henan Province is still a high prevalence region for drug-resistant TB, and strains collected from local TB cases have diverse genotypes, of which the Beijing family type is predominant.

Development of potent μ and δ opioid agonists with high lipophilicity

An SAR study on the Dmt-substituted enkephalin-like tetrapeptide with a N-phenyl-N-piperidin-4-ylpropionamide moiety at the C-terminal was performed and has resulted in highly potent ligands at μ and δ opioid receptors. In general, ligands with the substitution of D-Nle(2) and halogenation of the aromatic ring of Phe(4) showed highly increased opioid activities. Ligand 6 with good biological activities in vitro demonstrated potent in vivo antihyperalgesic and antiallodynic effects in the tail-flick assay.

Limiting an Insect Infestation of Nitrogen-Fixing Root Nodules of the Pigeon Pea (Cajanus cajan) by Engineering the Expression of an Entomocidal Gene in Its Root Nodules

A region of DNA which determined the production of the insecticidal toxin of Bacillus thuringiensis subsp. israelensis was cloned into a derivative of a broad-host-range group IncQ plasmid vector of gram-negative bacteria. The plasmid which we constructed was transferred by conjugative mobilization into a Bradyrhizobium species that nodulates pigeon peas. In this species the construction was maintained stably in the absence of selection and expressed the gene that was installed. Experiments in a greenhouse with the strain which we constructed indicated that this organism provides protection against root nodule damage by the larvae of the insect Rivellia angulata (Diptera).

Design and synthesis of trivalent ligands targeting opioid, cholecystokinin, and melanocortin receptors for the treatment of pain

It has been known that co-administration of morphine with either cholecystokinin (CCK) receptor or melanocortin (MC) receptor antagonists enhance morphine's analgesic efficacy by reducing serious side effects such as tolerance and addiction. Considering these synergistic effects, we have designed trivalent ligands in which all three different pharmacophores for opioid, CCK, and MC receptors are combined in such a way as to conserve their own topographical pharmacophore structures. These ligands, excluding the cyclic compound, were synthesized by solid phase synthesis using Rink-amide resin under microwave assistance in very high yields. These trivalent ligands bind to their respective receptors well demonstrating that the topographical pharmacophore structures for the three receptors were retained for receptor binding. Ligand 10 was a lead compound to show the best biological activities at all three receptors.

The biological activity and metabolic stability of peptidic bifunctional compounds that are opioid receptor agonists and neurokinin-1 receptor antagonists with a cystine moiety

In order to improve metabolic stability, a ring structure with a cystine moiety was introduced into TY027 (Tyr-D-Ala-Gly-Phe-Met-Pro-Leu-Trp-NH-[3',5'-(CF(3))(2)Bzl]), which is a lead compound of our developing bifunctional peptide possessing opioid agonist and NK1 antagonist activities. TY038 (Tyr-cyclo[D-Cys-Gly-Phe-Met-Pro-D-Cys]-Trp-NH-[3',5'-(CF(3))(2)Bzl]) was found as a highly selective delta opioid agonist over mu receptor in conventional tissue-based assays, together with an effective NK1 antagonist activity and good metabolic stability with more than 24h half life in rat plasma.

The importance of micelle-bound states for the bioactivities of bifunctional peptide derivatives for delta/mu opioid receptor agonists and neurokinin 1 receptor antagonists

To provide new insight into the determining factors of membrane-bound peptide conformation that might play an important role in peptide-receptor docking and further biological behaviors, the dodecylphosphocholine (DPC) micelle-bound conformations of bifunctional peptide derivatives of delta-preferring opioid agonists and NK1 antagonists (1: Tyr-D-Ala-Gly-Phe-Met-Pro-Leu-Trp-O-3,5-Bzl(CF 3) 2; 2: Tyr-D-Ala-Gly-Phe-Met-Pro-Leu-Trp-NH-3,5-Bzl(CF 3) 2; 3: Tyr-D-Ala-Gly-Phe-Met-Pro-Leu-Trp-NH-Bzl) were determined based on 2D NMR studies. Although the differences in the primary sequence were limited to the C-terminus, the obtained NMR conformations were unexpectedly different for each compound. Moreover, their biological activities showed different trends in direct relation to the compound-specific conformations in DPC micelles. The important result is that not only were the NK1 antagonist activities different (the pharmacophore located at the C-terminus)but the opioid agonist activities (this pharmacophore was at the structurally preserved N-terminus) also were shifted, suggesting that a general conformational change in the bioactive state was induced due to relatively small and limited structural modifications.

Structure-activity relationships of bifunctional cyclic disulfide peptides based on overlapping pharmacophores at opioid and cholecystokinin receptors

Prolonged opioid exposure increases the expression of cholecystokinin (CCK) and its receptors in the central nervous system (CNS), where CCK may attenuate the antinociceptive effects of opioids. The complex interactions between opioid and CCK may play a role in the development of opioid tolerance. We designed and synthesized cyclic disulfide peptides and determined their agonist properties at opioid receptors and antagonist properties at CCK receptors. Compound 1 (Tyr-c[d-Cys-Gly-Trp-Cys]-Asp-Phe-NH(2)) showed potent binding and agonist activities at delta and mu opioid receptors but weak binding to CCK receptors. The NMR structure of the lead compound displayed similar conformational features of opioid and CCK ligands.

Opioid and melanocortin receptors: do they have overlapping pharmacophores?

We have identified compound 1 as a novel ligand for opioid and melanocortin (MC) receptors, which is derived from the overlapping of a well known structure for the delta opioid receptor, 2,6-dimethyltyrosine (Dmt)-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (Tic), and a small molecule for the MC receptor, Tic-DPhe(p-Cl)-piperidin-4-yl-N-phenyl-propionamide. Ligand 1 showed that there is an overlapping pharmacophore between opioid and MC receptors through the Tic residue. The ligand displayed high biological activities at the delta opioid receptor (Ki = 0.38 nM in binding assay, EC(50) = 0.48 nM in GTP-gamma-S binding assay, IC(50) = 74 nM in MVD) as an agonist instead of an antagonist and showed selective binding affinity (IC(50) = 2.3 muM) at the MC-3 receptor rather than at the MC-5 receptor. A study of the structure-activity relationships demonstrated that the residues in positions 2, 3, and the C-terminus act as a pharmacophore for the MC receptors, and the residues in positions 1 and 2 act as a pharmacophore for the opioid receptors. Thus, this structural construct can be used to prepare chimeric structures with adjacent or overlapping pharmacophores for opioid and MC receptors.

Development of novel enkephalin analogues that have enhanced opioid activities at both mu and delta opioid receptors

Enkephalin analogues with a 4-anilidopiperidine scaffold have been designed and synthesized to achieve therapeutic benefit for the treatment of pain due to mixed mu and delta opioid agonist activities. Ligand 16, in which a Dmt-substituted enkephalin-like structure was linked to the N-phenyl-N-piperidin-4-yl propionamide moiety, showed very high binding affinities (0.4 nM) at mu and delta receptors with an increased hydrophobicity (aLogP = 2.96). This novel lead compound was found to have very potent agonist activities in MVD (1.8 nM) and GPI (8.5 nM) assays.

Design, synthesis, and biological evaluation of novel bifunctional C-terminal-modified peptides for delta/mu opioid receptor agonists and neurokinin-1 receptor antagonists

A series of bifunctional peptides that act as agonists for delta and mu opioid receptors with delta selectivity and as antagonist for neurokinin-1 (NK1) receptors were designed and synthesized for potential application as analgesics in various pain states. The peptides were characterized using radioligand binding assays and functional assays using cell membrane and animal tissue. Optimization was performed on the fifth residue which serves as an address moiety for both receptor recognitions. It had critical effects on both activities at delta/mu opioid receptors and NK1 receptors. Among the synthesized peptides, H-Tyr-D-Ala-Gly-Phe-Met-Pro-Leu-Trp-O-3,5-Bzl(CF3) 2 (5) and H-Tyr-D-Ala-Gly-Phe-Nle-Pro-Leu-Trp-O-3,5-Bzl(CF3)2 (7) had excellent agonist activity for both delta opioid and mu opioid receptors and excellent antagonist activity for NK1 receptors. These results indicate that the rational design of multifunctional ligands with opioid agonist and neurokinin-1 antagonist activities can be accomplished and may provide a new tool for treatment of chronic and several pain states.

Partial retro-inverso, retro, and inverso modifications of hydrazide linked bifunctional peptides for opioid and cholecystokinin (CCK) receptors

Partially modified retro-inverso, retro, and inverso isomers of hydrazide linked bifunctional peptides were designed, synthesized, and evaluated for bioactivities at delta/mu opioid receptors and CCK-1/CCK-2 receptors. All modifications of the CCK pharmacophore moiety affected bioactivities for the CCK-1 and CCK-2 receptors (up to 180-fold increase in the binding affinity with higher selectivity) and for the delta and mu opioid receptors. The results indicate that the opioid and CCK pharmacophores in one molecule interact with each other to induce topographical changes for both pharmacophores.

Understanding the structural requirements of 4-anilidopiperidine analogues for biological activities at mu and delta opioid receptors

New 4-anilidopiperidine analogues in which the phenethyl group of fentanyl was replaced by several aromatic ring-contained amino acids (or acids) were synthesized to study the biological effect of the substituents on mu and delta opioid receptor interactions. These analogues showed broad (47 nM-76 microM) but selective (up to 17-fold) binding affinities at the mu opioid receptor over the delta opioid receptor, as predicted from the message-address concept.

Dynorphin A activates bradykinin receptors to maintain neuropathic pain

Dynorphin A is an endogenous opioid peptide that produces non-opioid receptor-mediated neural excitation. Here we demonstrate that dynorphin induces calcium influx via voltage-sensitive calcium channels in sensory neurons by activating bradykinin receptors. This action of dynorphin at bradykinin receptors is distinct from the primary signaling pathway activated by bradykinin and underlies the hyperalgesia produced by pharmacological administration of dynorphin by the spinal route in rats and mice. Blockade of spinal B1 or B2 receptor also reverses persistent neuropathic pain but only when there is sustained elevation of endogenous spinal dynorphin, which is required for maintenance of neuropathic pain. These data reveal a mechanism for endogenous dynorphin to promote pain through its agonist action at bradykinin receptors and suggest new avenues for therapeutic intervention.

Synthesis and evaluation of 3-aminopropionyl substituted fentanyl analogues for opioid activity

An enkephalin analogue coupled to 'aminofentanyl' has been synthesized and tested for biological activities at the mu and delta opioid receptors. Aminofentanyl which represents a structural derivative of fentanyl has been synthesized by acylation of 1-(2-phenethyl)-4-(N-anilino)piperidine with phthaloyl protected beta-alaninyl chloride in the presence of DIPEA, followed by deprotection with hydrazine hydrate. Aminofentanyl has also been successfully acylated with ethyl isocyanate, various acid anhydrides, to further investigate structure-activity relationships of these new fentanyl derivatives. Among the new derivatives compound 7 which carries a Tyr-D-Ala-Gly-Phe opioid message sequence showed good opioid affinity (1 nM at both delta and mu opioid receptors) and bioactivity (34.9 nM in MVD and 42 nM in GPI/LMMP bioassays).

Structure-activity relationships of bifunctional peptides based on overlapping pharmacophores at opioid and cholecystokinin receptors

Cholecystokinin (CCK) has been identified as a pronociceptive endogenous peptide which also possesses antiopioid actions. CCK may be upregulated in conditions of chronic pain or during sustained morphine administration resulting in attenuation of opioid-mediated pain relief. These complex interactions between opioids and endogenous CCK receptor systems have suggested the need for a new paradigm in drug design for some states of chronic pain. In these circumstances the rational design of potential drugs for the treatment of these conditions must be based on one ligand for multiple targets. We have designed a single peptide which can interact with delta and mu opioid receptors as agonists and with CCK receptors as antagonists. The ligands were designed based on a model of overlapping pharmacophores of opioid and CCK peptide ligands, which incorporates opioid pharmacophores at the N-terminal and CCK tetrapeptide pharmacophores at the C-terminal of the designed ligands. We measured binding and activities of our bifunctional peptides at opioid and CCK receptors. Compound 11 (Tyr-d-Ala-Gly-d-Trp-NMeNle-Asp-Phe-NH(2)) demonstrated opioid agonist properties at delta and mu receptors (IC(50) = 63 +/- 27 nM and 150 +/- 65 nM, respectively in MVD and GPI tissue assays) and high binding affinity at CCK-1 and CCK-2 receptors (K(i) = 320 and 1.5 nM, respectively). Compound 9 (Tyr-d-Nle-Gly-Trp-Nle-Asp-Phe-NH(2)) displayed potent agonist activity at delta and mu receptors (IC(50) = 23 +/-10 nM and 210 +/- 52 nM, respectively in MVD and GPI tissue assays), with a balanced binding affinity for CCK-1 and CCK-2 receptors (K(i) = 9.6 and 15 nM, respectively). These results provide evidence supporting the concept that opioid and CCK receptors have overlapping pharmacophores required for binding affinity and biological activity and that designing overlapping pharmacophores of two peptides into a single peptide is a valid drug design approach.

Design and synthesis of novel hydrazide-linked bifunctional peptides as delta/mu opioid receptor agonists and CCK-1/CCK-2 receptor antagonists

A series of hydrazide-linked bifunctional peptides designed to act as agonists for delta/mu opioid receptors and antagonists for CCK-1/CCK-2 receptors was prepared and tested for binding to both opioid and CCK receptors and in functional assays. SAR studies in the CCK region examined the structural requirements for the side chain groups at positions 1', 2', and 4' and for the N-terminal protecting group, which are related to interactions not only with CCK, but also with opioid receptors. Most peptide ligands that showed high binding affinities (0.1-10 nM) for both delta and mu opioid receptors generally showed lower binding affinities (micromolar range) at CCK-1 and CCK-2 receptors, but were potent CCK receptor antagonists in the GPI/LMMP assay (up to Ke = 6.5 nM). The results indicate that it is reasonable to design chimeric bifunctional peptide ligands for different G-protein coupled receptors in a single molecule.

Design and synthesis of novel hydrazide-linked bifunctional peptides as delta/mu opioid receptor agonists and CCK-1/CCK-2 receptor antagonists

A series of hydrazide-linked bifunctional peptides designed to act as agonists for delta/mu opioid receptors and antagonists for CCK-1/CCK-2 receptors was prepared and tested for binding to both opioid and CCK receptors and in functional assays. SAR studies in the CCK region examined the structural requirements for the side chain groups at positions 1', 2', and 4' and for the N-terminal protecting group, which are related to interactions not only with CCK, but also with opioid receptors. Most peptide ligands that showed high binding affinities (0.1-10 nM) for both delta and mu opioid receptors generally showed lower binding affinities (micromolar range) at CCK-1 and CCK-2 receptors, but were potent CCK receptor antagonists in the GPI/LMMP assay (up to Ke = 6.5 nM). The results indicate that it is reasonable to design chimeric bifunctional peptide ligands for different G-protein coupled receptors in a single molecule.

'Knock-down' of spinal CB1 receptors produces abnormal pain and elevates spinal dynorphin content in mice

Recent studies demonstrate the possible existence of tonic modulatory control of nociceptive input mediated by spinal cannabinoid receptors (CB1). Accordingly, it is predicted that a reduction in the spinal CB1 receptors may enhance sensitivity to sensory stimuli and a decrease in spinal antinociceptive potency to cannabinoid agonists. An antisense oligodeoxynucleotide (ODN) specific to the CB1 receptor was used to 'knock-down' CB1 receptors in the lumbar spinal cord and dorsal root ganglia by the local, repeated intrathecal (i.th.) administration of the ODN. This treatment resulted in a decrease in lumbar spinal CB1 receptor expression accompanied by a decrease in the response thresholds to both innocuous tactile and noxious thermal stimuli. The antinociceptive action of the CB1 agonist, WIN 55,212-2, by i.th. administration was also significantly attenuated after treatment with the antisense ODN. Similar treatment using a mismatch control ODN had no effect on receptor protein or on sensory thresholds. The effects of the antisense ODN treatment on sensory thresholds were fully reversed after discontinuation of the ODN injection. The antisense ODN treated rats also showed a significant increase in lumbar spinal dynorphin A. Acute i.th. injection of MK-801 or an antidynorphin antiserum blocked the antisense ODN-induced tactile and thermal hypersensitivity. These data support the possibility of endogenous inhibitory cannabinoid tone to limit spinal afferent input of thermal and tactile stimuli. Lifting of this inhibitory tone through a 'knock-down' of spinal CB1 receptors apparently lowers the thresholds for sensory input, as reflected by the actions of MK-801 to block tactile and thermal hypersensitivity. The increased spinal dynorphin may act to further promote afferent outflow and abnormal pain because sequestration of spinal dynorphin with antiserum also reverses the manifestations of abnormal pain following knock-down of CB1 receptors.

Transgenic plants expressing autoantigens fed to mice to induce oral immune tolerance

Oral administration of protein can induce antigen-specific immune hyporesponsiveness. However, the utility of oral tolerance to autoantigens in the treatment of autoimmune diseases may be limited when candidate autoantigens cannot be produced by conventional systems in quantities sufficient for clinical studies. Plants may be ideally suited for this purpose, as they can synthesize, glycosylate and assemble mammalian proteins to provide huge quantities of relatively low cost soluble proteins. Furthermore, edible transgenic plants could provide a simple and direct method of autoantigen delivery for oral tolerance. Therefore, the aim of this study was to determine whether a transgenic plant expression system was capable of synthesizing the diabetes-associated autoantigen, glutamic acid decarboxylase (GAD) in an immunogenic form and whether the oral administration of an autoantigen expressed by a plant could directly induce protective immune responses in a mouse model of diabetes. We show that a GAD-expressing transgenic plant, given as a dietary supplement, inhibits the development of diabetes in the non-obese diabetic (NOD) mouse.

Tramadol, M1 metabolite and enantiomer affinities for cloned human opioid receptors expressed in transfected HN9.10 neuroblastoma cells

Tramadol hydrochloride is a centrally acting synthetic analgesic in widespread clinical use. Despite different degrees of opioid-like characteristics in preclinical tests, it is characterized by lack of full naloxone reversibility or naloxone-precipitated withdrawal in humans. To investigate this apparent discrepancy, the present study measured the affinity of tramadol (and its enantiomers) and an active O-desmethyl metabolite (M1) (and its enantiomers) to cloned human opioid receptors of the mu, delta and kappa type stably expressed in HN9.10 neuroblastoma cells. At mu sites, the Ki values for tramadol, its (+) and (-) enantiomers, M1, and its (+) and (-) enantiomers were 17000, 15700, 28800, 3190, 153 and 9680 nM, respectively, compared to 7.1 nM for morphine. These results are consistent with the suggestion of a non-opioid contribution to the clinical profile of tramadol.

Pharmacological characterization of the cloned kappa opioid receptor as a kappa 1b subtype

Substantial pharmacological evidence in vitro and in vivo has suggested the existence of subtypes of the kappa opioid receptor. Quantitative radioligand binding techniques resolved the presence of two high affinity binding sites for the kappa 1 ligand [3H]U69,593 in mouse brain membranes, termed kappa 1a and kappa 1b, respectively. Whereas the kappa 1a site has high affinity for fedotozine and oxymorphindole and low affinity for bremazocine and alpha-neoendorphin, site kappa 1b has high affinity for bremazocine and alpha-neoendorphin and low affinity for fedotozine and oxymorphindole. CI-977 and U69,593 bind equally well at both sites. To determine the relationship between these kappa 1 receptor subtypes and the recently cloned mouse kappa 1 receptor (KOR), we examined [3H]U69,593 binding to the KOR in stably transfected cells (KORCHN-8). Competition of [3H]U69,593 binding to the KOR by bremazocine, alpha-neoendorphin, fedotozine and oxymorphindole resolved a single class of binding sites at which these agents had binding affinities similar to that of the kappa 1b site present in mouse brain. These results suggest that the cloned KOR corresponds to the kappa 1 site in mouse brain defined as kappa 1b.

Transient myeloproliferative disorder and acute myeloid leukemia: study of six neonatal cases with long-term follow-up

Six neonates with hematological and clinical pictures indistinguishable from acute myeloid leukemia were studied. Two patients had Down syndrome and three others had either +21 or i(21q) chromosomal abnormalities in their blood cells at presentation. Granulocyte-macrophage colony-forming unit assays performed in bone marrow and peripheral blood mononuclear cells revealed abnormal growth patterns in two patients; both died of progressive disease of acute myeloid leukemia. All the other four neonates with normal in vitro cell growth pattern had spontaneous remission within 7 months. Of these four patients, one remains well and in remission for 8 years and the other three developed acute myeloid leukemia at the ages of 15, 32 and 19 months, respectively. We conclude that the in vitro cell growth pattern is helpful to distinguish transient myeloproliferative disorder from congenital acute myeloid leukemia and that patients with the former condition are at risk to develop acute myeloid leukemia subsequently.

Cloning and sequence analysis of a p40 structural protein gene of Helicoverpa zea nuclear polyhedrosis virus

A gene encoding an occluded virion structural protein was isolated from an expression library constructed from the Helicoverpa zea S-type nuclear polyhedrosis virus (NPV) isolate HzS-15 using both polyclonal and monoclonal antibody screening. The gene was located within a Pstl-Sall fragment of the HzS-15 genome spanning from 96.5 to 97.3 m.u. Sequencing analyses revealed a long open reading frame of 927 nucleotides that predicted a protein of 37 kDa in size. Immunoblot analyses using the monoclonal antibody ENV409 demonstrated that the gene corresponded to a 40-kDa protein (p40) in SDS-polyacrylamide gels that was present exclusively in enveloped occluded virions but not in extracellular budded virions or envelope-stripped nucleocapsids. A p40 protein-specific transcript was detected at 16 hr postinfection in HzS-15-infected Hz 1075/UND-K cells and remained until 22 hr. Primer extension analyses demonstrated that the p40 protein-specific transcript started at -49 nucleotides from the ATG start codon within an ATAAG consensus pentamer found in late protein genes of Baculoviruses. The deduced amino acid sequence of the HzS-15 p40 protein gene shared 44 and 45% sequence homology with the p40 proteins of Bombyx mori NPV and Autographa californica NPV, respectively.

Chimeric M1/M2 muscarinic receptors: correlation of ligand selectivity and functional coupling with structural modifications

Chimeric M1/M2 receptors were expressed in murine fibroblasts (B82) transfected with recombinant m1/m2 receptor genes. The binding affinities of a number of muscarinic antagonists and the agonist carbachol for these chimeric receptors were compared with the ligands' affinities for the M1 and M2 receptors expressed in the B82 cells. The tricyclic compounds, namely pirenzepine (PZ), 11-([2-[(diethylamino)methyl]-1-piperidinyl]acetyl)-5,11- dihydro-6H-pyrido-[2,3-6][1,4]benzodiazepine-6-one (AF-DX 116) and himbacine, shared a binding site between transmembrane domains VI and VII. However, the selective interaction of pirenzepine with M1 and AF-DX 116 and himbacine with M2 involved different structural regions. The high-affinity binding for 4-diphenylacetoxy-N- methylpiperidine and hexahydrosiladifenidol was confined to within loop o2 and transmembrane domains V and VI, which were clearly distinguishable from those of the tricyclic compounds. These results support the hypothesis that the ligands' stereochemical features are critical in their optimal alignment within the ligand binding pocket. The cytoplasmic i3 loop modulated the binding of carbachol such that receptors which contained the i3 domain from the M2 receptor exhibited a single high-affinity state, whereas those with the i3 domain from the M1 receptor had an additional low-affinity state for the agonist. The i3 regions are essential for the differential functional coupling of the M1 and M2 receptors to second messenger systems; however, additional upstream regions seem to be essential for a potent and efficacious activation of phospholipase C by the M1 receptor. This study provides new insight into the molecular basis of ligand selectivity.

Disparate effects of fenfluramine on thermogenesis in brown adipose tissue in the rat

It has been suggested that fenfluramine, a clinically used appetite suppressant, can also promote weight loss by augmenting energy expenditure, as indicated by increased whole-body O2 consumption (VO2) and mitochondrial GDP binding in brown adipose tissue (BAT) of fenfluramine-treated rats. To further investigate a possible involvement of BAT in the drug's metabolic effects, 113Sn-labelled microspheres were injected into the left cardiac ventricle of conscious rats 70-80 min after intraperitoneal delivery of 20 mg/kg fenfluramine (DL-mixture) or saline vehicle. At 28 degrees C ambient temperature, fenfluramine augmented resting whole-body VO2 and increased the microsphere entrapment in BAT, indicating enhanced blood flow and metabolism. At 20 degrees C ambient temperature, the expected increase in BAT blood flow associated with nonshivering thermogenesis was observed in control rats, but in fenfluramine-treated rats the increase in BAT blood flow was severely attenuated, and VO2 and body temperature were reduced. The stimulatory effect of fenfluramine on BAT metabolism was not prevented by urethane anesthesia but did not occur if the tissue was denervated. These blood flow measurements corroborate previous reports, based on GDP-binding assays, that fenfluramine treatment can augment thermogenesis in BAT by effects mediated through the innervation of the tissue. However, the data also indicate that this calorigenic effect is dependent on ambient temperature being near thermoneutrality and that in a cool environment the drug inhibits BAT thermogenesis.

New Field Isolates of Rhizobium leguminosarum Biovar Viciae That Nodulate the Primitive Pea Cultivar Afghanistan in Addition to Modern Cultivars

A collection of 13 field isolates of Rhizobium leguminosarum bv. viciae that have the ability to nodulate the roots of current North American cultivars of peas as well as a “primitive” cultivar, Afghanistan, was examined. These isolates originated in diverse geographical regions of the world, which indicates that this phenotype is not restricted to isolates from any one region. When subclones of the nodulation region from one plasmid were used to examine Eco RI-fragment-length polymorphisms in this collection of strains as well as in a collection comprising strains that do not nodulate the primitive cultivar, polymorphism was found in both collections. With one exception, RisφA6, all strains that nodulated cv. Afghanistan pea contained a region called nodX as an extension to the nodA BCIJ operon that has been observed in all R. leguminosarum bv. viciae strains, including those that do not nodulate cv. Afghanistan pea. RisφA6 was also the only strain in which nodulating ability could not be associated with a conjugative plasmid.

Brown adipose tissue, liver, and diet-induced thermogenesis in cafeteria diet-fed rats

Diet-induced thermogenesis (DIT) in young rats overeating a "cafeteria" (CAF) diet of palatable human foods is characterized by a chronic, propranolol-inhibitable elevation in resting metabolic rate (VO2) and is associated with various changes in brown adipose tissue (BAT) that have been taken as evidence for BAT as the effector of DIT. But direct evidence for participation of BAT in DIT has been lacking. By employing a nonocclusive cannula to sample the venous effluent of interscapular BAT (IBAT) for analysis of its O2 content and measuring tissue blood flow with microspheres, we accomplished direct determination (Fick principle) of the O2 consumption of BAT in conscious CAF rats. In comparison with normophagic controls fed chow, the CAF rats exhibited a 43% increase in metabolizable energy intake, reduced food efficiency, a 22% elevation in resting VO2 at 28 degrees C (thermoneutrality) or 24 degrees C (housing temperature), and characteristic changes in the properties of their BAT (e.g., increased mass, protein content and mitochondrial GDP binding). They also exhibited the greater metabolic response to exogenous noradrenaline characteristic of CAF rats and the near elimination by propranolol of their elevation in VO2. By the criterion of their elevated VO2, the CAF rats were exhibiting DIT at the time of the measurements of BAT blood flow and blood O2 levels. However, BAT O2 consumption was found to be no greater in the CAF rats than in the controls at either 28 or 24 degrees C. At 28 degrees C it accounted for less than 1% of whole body VO2; at 24 degrees C it increased to about 10% of overall VO2 in both diet groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Granulocyte/macrophage colony-forming units from cord blood of premature and full-term neonates: its role in ontogeny of human hemopoiesis

It is still uncertain whether the yolk sac is the only origin of hemopoietic stem cells during fetal development. We studied the level of circulating granulocyte/macrophage colony-forming unit (CFU-GM) from the 23rd week of gestation to fullterm, trying to delineate its role in the ontogeny of human hemopoiesis. Cord blood samples were collected from 45 healthy premature neonates and 91 healthy full-term neonates. CFU-GM assays were performed using a single agar layer system with human placental conditioned medium as a source of colony stimulating activity. The mean numbers of colonies produced from the cord blood samples of the premature and full-term neonates were 116 +/- 185 (SD) and 96 +/- 113/2 x 10(5) mononuclear cells, respectively. There was no statistical difference between the numbers of colonies of the two groups (Mann-Whitney test, p greater than 0.05). These results indicate that the level of circulating CFU-GM from the 23rd week of gestation to full term is constantly high and add credence to the assumption that CFU-GM are produced not only from the yolk sac but also from other hemopoietic sites.

Absence of increased oxygen consumption in brown adipose tissue of rats exhibiting "cafeteria" diet-induced thermogenesis

Young male Sprague-Dawley rats were induced to overeat (approximately 45%) by provision of a "cafeteria" (CAF) diet of palatable human foods. Normophagic rats fed a commercial chow or a semisynthetic diet served as controls. The CAF rats exhibited (a) the reduced food efficiency and the propranolol-inhibitable elevation in resting metabolic rate (resting VO2) that are indicative of a facultative diet-induced thermogenesis (DIT) by which excess energy gain is resisted, and (b) certain changes in brown adipose tissue (BAT) that are among those taken as evidence for BAT as the effector of DIT, e.g., increased protein content and increased mitochondrial binding of GDP. To assess directly and quantitatively the contribution by BAT to the elevation in VO2 (apparent DIT) of the CAF rats, BAT O2 consumption was determined (Fick principle) from measurements of tissue blood flow (microsphere method) and the arteriovenous difference in blood O2 across interscapular BAT (IBAT). To obtain the measurements, the animals were fitted under halothane anesthesia with vascular cannulas for intraventricular injection of microspheres and sampling of arterial blood and the venous effluent of IBAT. After recovery from anesthesia and rewarming to normal body temperature the animals were placed singly in a temperature-controlled metabolic chamber and the measurements, which also included determination of resting VO2, were made 1.5-2 h later about 11:30 h. As determined from measurements made at 28 degrees C (thermoneutrality) mean values of resting VO2 for the cannulated rats were unchanged from those of intact (unoperated) CAF or control rats.(ABSTRACT TRUNCATED AT 250 WORDS)

A simple and rapid in situ staining method for granulocyte-macrophage colonies in agar culture

This report describes a very simple, quick and effective method for in situ staining of granulocyte-macrophage colonies in agar cultures and for classifying various colony types. The procedure takes only one minute to fix and a few minutes to stain; a few additional minutes are required for preparation of the permanent whole plate. In this process the Riu stain, a modified Romanowsky stain, is used. Besides the ease and rapidity of this procedure, the identification of colony types appears to be enhanced. Thus, the method seems to be very beneficial in routine observations of colony types.

Evidence for liver as the major site of the diet-induced thermogenesis of rats fed a "cafeteria" diet

The resting metabolic rates (VO2) of rats fed chow (CH) or a "cafeteria" (CAF) diet of highly palatable human foods were measured at thermoneutrality (28 degrees C) before and shortly after two-thirds hepatectomy or sham operation, and again after administration of propranolol (5 mg/kg). CAF rats initially had a 17% and 1.2 mL/min higher mean resting VO2 than CH rats, a difference usually considered to represent the diet-induced thermogenesis (DIT) that CAF rats develop during overconsumption of the diet. Sham operation did not significantly affect resting VO2 in either diet group. Two-thirds hepatectomy decreased VO2 by about 1.0 mL/min more (125% more) in CAF rats than in CH rats, from which it may be estimated that the CAF rats initially had a liver VO2 about 1.6 mL/min higher than that of the CH rats, a difference more than sufficient to fully account for their apparent DIT. Propranolol did not significantly affect the VO2 of CH rats. It reduced the VO2 of sham-operated CAF rats by 0.94 +/- 0.08 mL/min (12%), but had a significantly smaller effect (delta VO2 = -0.50 +/- 0.05 mL/min) in partially hepatectomized CAF rats. This difference suggests that about 70% of the propranolol-inhibitable fraction of the elevated VO2 of the CAF rats, presumably a measure of sympathetically mediated DIT, resided in the liver. This study thus points to the liver as the major (70-100%) effector of the DIT of CAF rats.

A nonocclusive cannula for sampling venous blood from the interscapular brown fat of conscious rats

Lack of an adequate method for sampling venous blood from the brown adipose tissue (BAT) of conscious animals has impeded study of the in vivo metabolism of this tissue during physiological activation of its thermogenic function. This paper describes a technique for cannulating the main vein (Sulzer's) of the interscapular BAT (IBAT) of rats in a manner that does not impair blood flow and allows multiple venous sampling over several hours in conscious animals. The technique was tested over the widest possible range of IBAT blood flows by applying it to measurements of IBAT arteriovenous O2 differences in barbital-anesthetized, cold-acclimated rats infused with vehicle or with various doses of noradrenaline. Comparison was made with controls in which samples of IBAT venous blood were obtained by cutting Sulzer's vein. Blood flow was measured by the microsphere method. These tests showed that the presence of the special cannula in Sulzer's vein had no significant effect on the blood flow, arteriovenous O2 difference, or O2 consumption of the IBAT at any level of noradrenaline-induced thermogenesis. The new technique will permit examination of the functioning of BAT in nonshivering thermogenesis and diet-induced thermogenesis under much more physiological conditions than hitherto possible. It should also significantly reduce the number of animals required for such studies.

Starvation-induced changes in metabolic rate, blood flow, and regional energy expenditure in rats

Starvation results in an energy-conserving reduction in metabolic rate that has features of an adaptive response. Tissue and organ sites of this response were investigated by examining the effects of starvation for 5 d on tissue blood flow (microsphere method) and regional arteriovenous O2 differences ((a-v)O2) in conscious rats resting quietly at 28 degrees C. Comparison was with fed and overnight-fasted animals. Whole body resting metabolic rates (MR), colonic temperatures (Tc), and tissue weights were also determined. Quantitative changes in energy expenditure (as O2 consumption) were obtained for two regions: the portal-drained viscera (PDV) and the hindquarters (HQ). Fasting overnight resulted in increased blood flow to white adipose tissue (WAT) and decreased flow to the brain, PDV, testes, and skin; however, MR, Tc, the two regional ((a-v)O2, and the weights of most tissues were not significantly altered. In comparison with overnight fasting, starvation for 5 d resulted in a 13% reduction in body weight, weight loss in many tissues and organs, a 26% reduction in MR, a decline of 0.5 degree C in Tc, decreased (a-v)O2 across both the PDV and HQ, reduced cardiac output, and decreased blood flow to the heart, PDV, skin, WAT, leg muscle, HQ, and the musculoskeletal body as a whole. Utilization of O2 by the PDV and HQ (flow X (a-v)O2) declined by amounts that accounted for 22 and 18%, respectively, of the reduction in MR. The reductions in cardiac output (18%) and heart blood flow (36%) indicate that the heart also made a contribution to energy conservation (roughly estimated as 5%).(ABSTRACT TRUNCATED AT 250 WORDS)

The noradrenaline content and innervation of brown adipose tissue in the young rabbit

This work examined the noradrenaline content of brown adipose tissue, the metabolic response to endogenous noradrenaline released during tyramine infusion, and the innervation of brown fat at the electron microscopic level in the young rabbit. The noradrenaline content (ng/g) of the interscapular and cervical fat deposits ranged from 256 +/- 51 to 343 +/- 59 and 399 +/- 18 to 694 +/- 92, respectively, in four groups of rabbits (1-2, 7-8, 12-13, and 25-27 days of age). There was considerable variation amongst animals in each age group, but no evidence of a major increase or decrease in noradrenaline content during the first 4 weeks of life. Intravenous infusion of tyramine (100 micrograms X kg-1 X min-1) increased plasma noradrenaline concentration, oxygen consumption, and blood flow to brown fat. Thus noradrenaline released from endogenous sites, as well as injected noradrenaline, will initiate the thermogenic response of brown fat. Ultrastructurally, unmyelinated axons that were not organized in a fascicle were observed adjacent to the adipocytes in the late gestation fetus. By 1 week of age of axons were surrounded by Schwann cell cytoplasm which formed a fascicle. However, no evidence of myelination was found up to 21 days of age. Collectively, the data indicate that the brown adipocyte is fully responsive at 1-2 days of age even though myelination of the nerves is incomplete, and that the incomplete development of the sympathetic nerves at birth is not a factor in the synthesis of noradrenaline in the very young rabbit. In addition, brown fat of the newborn rabbit is not as thermogenically active as the brown fat of the cold-acclimated rat.

Uptake of glucose and release of fatty acids and glycerol by rat brown adipose tissue in vivo

The net in vivo uptake or release of free fatty acids glycerol, glucose, lactate, and pyruvate by the interscapular brown adipose tissue (IBAT) of barbital-anesthetized, cold-acclimated rats was determined from measurements of plasma arteriovenous concentration differences across IBAT and tissue blood flow. Measurements were made without stimulation of the tissue and also during submaximal and maximal stimulation by infused noradrenaline (NA), the physiological activator of BAT thermogenesis. There was no appreciable uptake of glucose or release of fatty acids and glycerol by the nonstimulated tissue. At both levels of stimulation there was significant uptake of glucose (1.7 and 2.0 mumol/min) and release of glycerol (0.9 and 1.2 mumol/min), but only at maximal stimulation was there significant release of fatty acids (1.9 mumol/min). Release of lactate and pyruvate accounted for 33% of the glucose taken up at submaximal stimulation and 88% at maximal stimulation. By calculation, the remainder of the glucose taken up was sufficient to have fueled about 12% of the thermogenesis at submaximal stimulation, but only about 2% at maximal stimulation. As estimated from the rate of glycerol release, the rate of triglyceride hydrolysis was sufficient at submaximal stimulation to fuel IBAT thermogenesis entirely with the resulting fatty acids, but it was not sufficient to do so at maximal stimulation when some of the fatty acid was exported. It is suggested that at maximal NA-induced thermogenesis a portion of lipolysis proceeded only to the level of mono- and di-glycerides with the result that glycerol release did not fully reflect the rate of fatty acid formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Potentiation of in vivo thermogenesis in rat brown adipose tissue by stimulation of alpha 1-adrenoreceptors is associated with increased release of cyclic AMP

Release of cyclic AMP (cAMP) from the interscapular brown adipose tissue (IBAT) of barbital-anesthetized, cold-acclimated rats given activators and inhibitors of brown adipose tissue (BAT) thermogenesis was assessed by measuring IBAT blood flow (microsphere method) and the arteriovenous difference in plasma cAMP across the tissue. The release was taken as an index of the generation of cAMP in the IBAT. During thermogenesis induced by infusion of graded doses of noradrenaline (NA), release of cAMP increased from no significant release without NA to 68 pmol/min at a NA dose that effected maximal thermogenesis. The alpha-adrenoreceptor antagonist dihydroergotoxin inhibited NA-induced BAT thermogenesis and markedly reduced the release of cAMP. The alpha 1-adrenoreceptor agonist phenylephrine potentiated the in vivo thermogenic response of BAT to isoproterenol or to a suboptimal dose of NA and enhanced the release of cAMP elicited by these catecholamines. But given alone, phenylephrine or dihydroergotoxin had very little or no effect on thermogenesis and cAMP release. These results suggest that stimulation of the alpha 1-adrenoreceptors on BAT adipocytes potentiates the thermogenic response originating from stimulation of the adenylate cyclase-coupled beta 1-adrenoreceptors by increasing, in some indirect way, the generation of cAMP, the intracellular messenger for activation of thermogenesis. However, in the absence of proof that adipocytes are the principal source of the cAMP released from IBAT, during catecholamine-induced thermogenesis, this explanation for the effect of alpha 1-adrenoreceptor stimulation on thermogenesis remains tentative.

Redox state of brown adipose tissue as a possible determinant of its blood flow

During norepinephrine (NE) induced thermogenesis in the adipocytes of brown adipose tissue (BAT), the blood flow of the tissue, and thus its oxygen supply, seems to be controlled by the adipocytes, possibly through their production of a vasodilator. This study sought to discover a metabolic parameter of the adipocytes that might account for modulation of vasodilator production and BAT blood flow. The blood flow of the interscapular BAT (IBAT) of anesthetized, cold-acclimated rats was varied by infusing NE and by altering the concentration of oxygen in arterial blood (AO2). Flow was measured with radiolabeled microspheres. IBAT was freeze fixed in situ for determination of its levels of adenine nucleotides and its cytosolic redox state; the latter was measured in terms of the concentration ratios, lactate/pyruvate (L/P) and glycerol-3-phosphate/dihydroxyacetone phosphate (GP/DHAP) in the tissue. The increase in IBAT blood flow with dose of NE was associated with a progressive decline in tissue ATP, increases in ADP and AMP at high doses of NE, and progressive increases in L/P and GP/DHAP, the latter increases indicating increased reduction of the cytosolic NAD+-NADH system. Reducing AO2 by hemodilution raised the blood flow, L/P, and GP/DHAP of IBAT to values significantly above those measured in rats of normal AO2 given the same doses of NE; whereas, elevating AO2 by hemoconcentration had the opposite effects on these values. For rats of normal or altered AO2 together, a correlation coefficient of 0.94 was obtained for the relation between IBAT blood flow and L/P and one of 0.85 for that between flow and GP/DHAP.(ABSTRACT TRUNCATED AT 250 WORDS)