Direct effect of PGF2α pulses on PRL pulses, based on inhibition of PRL or PGF2α secretion in heifers

The relationships between PRL and PGF_2α and their effect on luteolysis were studied. Heifers were treated with a dopamine-receptor agonist (bromocriptine; Bc) and a Cox-1 and -2 inhibitor (flunixin meglumine [FM]) to inhibit PRL and PGF_2α, respectively. The Bc was given (Hour 0) when ongoing luteolysis was indicated by a 12.5% reduction in CL area (cm²) from the area on Day 14 postovulation, and FM was given at Hours 0, 4, and 8. Blood samples were collected every 8-h beginning on Day 14 until Hour 48 and hourly for Hours 0 to 12. Three groups of heifers in ongoing luteolysis were used: control (n = 7), Bc (n = 7), and FM (n = 4). Treatment with Bc decreased (P < 0.003) the PRL concentrations averaged over Hours 1 to 12. During the greatest decrease in PRL (Hours 2-6), LH concentrations were increased. Progesterone concentrations averaged over hours were greater (P < 0.05) in the Bc group than in the controls. In the FM group, no PGFM pulses were detected, and PRL concentrations were reduced. Concentrations of PGFM were not reduced in the Bc group, despite the reduction in PRL. Results supported the hypothesis that a decrease (12.5%) in CL area (cm²) is more efficient in targeting ongoing luteolysis (63%) than using any day from Days 14 to ≥19 (efficiency/day, 10-24%). The hypothesis that PRL has a role in luteolysis was supported but was confounded by the known positive effect of LH on progesterone. The hypothesis was supported that the synchrony of PGFM and PRL pulses represents a positive effect of PGF_2α on PRL, rather than an effect of PRL on PGF_2α.     

Effect of 2-deoxyglucose, α-methylglucoside,and glucosamine on aflatoxin production by Aspergillus parasiticus

The effects of 2-deoxyglucose (2-DOG), -methylglucoside (-MG), and glucosamine (GA) on aflatoxin production by Aspergillus parasiticus were studied using conidia-initiated and replacement cultures. In conidia-initiated, 2-DOG, -MG, and GA supported varying amounts of growth when employed as sole carbon sources. In both conidia-initiated and replacement cultures, 2-DOG, but not -MG nor GA, as sole carbon sources support toxin formation. None of the compounds inhibited aflatoxin production when used in combination with glucose. It appears that neither 2-DOG, -MG, nor GA can be considered nonmetabolizable analogs of glucose in A. parasiticus.Abbreviations YES yeast extract sucrose - PMS peptone-mineral salts - 2-DOG L-deoxyglucose - -MG -methylglucoside - GA glucosamine     

Effect of 2, 2′-dipyridyl on the fermentation pattern of a silage simulation medium contaminated with fecal matter

Summary The fermentation pattern of a silage simulation medium contaminated with fecal matter, was followed during 7 days. Iron complexation due to 2,2-dipyridyl had no negative effect on the growth and the performance of lactic acid bacteria, but Enterobacteriaceae were effectively repressed.     

Dose-, time-, and tissue-dependent effects of 5-bromo-2′ -deoxyuridine on the in-vitro organogenesis of Arabidopsis thaliana

Vigorous organogenesis can be induced from hypocotyl and root explants of Arabidopsis thaliana using a two-step culture procedure consisting of preculture on callus-inducing medium (CIM) and subsequent culture on shoot-inducing medium (SIM) or root-inducing medium (RIM). With this culture system, we examined the influence of 5-bromo-2′-deoxyuridine (BrdU), a thymidine (dT) analogue, on plant organogenesis in vitro. Treatment with BrdU during SIM or RIM culture had negative effects on shoot and root redifferentiation over a broad range of concentrations. When explants were exposed to low concentrations of BrdU during preculture and then transferred onto BrdU-free SIM, shoot redifferentiation was accelerated significantly. At higher doses, BrdU treatment during the pre-culture inhibited shoot redifferentiation strongly in hypocotyl explants, but not in root explants. This suggests that a target of the BrdU action lies within the process of acquisition of cell proliferation competence specifically involved in hypocotyl dedifferentiation. These effects of BrdU were counteracted by the simultaneous addition of excess dT. BrdU-pretreated and untreated explants did not differ significantly in the phytohormone dependency of shoot redifferentiation. Our results provide a basis for future studies on plant organogenesis combining pharmacological analysis with BrdU as a probe and molecular genetics with Arabidopsis mutants.     

Impact of pain,psychological-distress,SARS-CoV2 fear on adults’ OHRQOL during COVID-19 pandemic

Corona virus disease (COVID-19) has crippled life, families and oral health care delivery. Hence, we assessed the impact of dental pain, fear of COVID-19 and psychological distress during lockdown on the oral health related quality of life of individuals visiting a tertiary dental care center during COVID-19 pandemic. Cross sectional study conducted among patients between 18 and 60 years. Demographics, access to pain killers, dental care (yes/no), duration (</> 15 days) and intensity of pain were self reported. Fear of COVID-19 was assessed using fear of corona virus scale (FCV-19S); psychological distress in the last 30 days and oral health related quality of life was evaluated. Oral examination was performed and dental caries status (DMFT) was assessed using the world health organization method. Univariate and multivariate regression analysis was conducted to evaluate significant predictors and 5% was set as level of significance. 2966 patients visited our dental emergency due to painful decayed tooth between March-June 2020. Mean age was 42.7 years, 53.97% were males and most common cause of painful teeth was upper right third molar (7.7%). 73.4% reported lack of pain medication; 95% reported closure of dental clinics close to home. Almost 79% suffered from dental pain for >15 days. Higher self reported pain (OR 2.1; 95% CI 1.36–14.71), >15 days of suffering from pain (OR 6.8; 95% CI 2.18–23.14), greater fear of COVID-19 (OR 4.14; 95% CI 1.98–16.07) and psychological distress (OR 4.41; 95% CI 1.09–16.76) were associated with poorer OHRQOL of adults during COVID-19 pandemic. Our findings strongly suggest that COVID-19 pandemic negatively impacts the mental and oral health of individuals affecting their overall health.     

Effects of Dietary Manganese on Cu, Fe, Zn, Ca, Se, IL-1β, and IL-2 Changes of Immune Organs in Cocks

Manganese (Mn) is an essential trace element required for normal development and bodily function. However, little is known about the effect of excessive amounts of Mn in immune organs of poultry. The aim of this study was to investigate the effect of dietary Mn on the content of trace elements, such as copper (Cu), iron (Fe), zinc (Zn), calcium (Ca), and selenium (Se), and the mRNA level of IL-1β and IL-2 in immune organs (spleen, thymus, and bursa of Fabricius) and the content of IL-1β and IL-2 in serum of poultry. Fifty-day-old male Hyline cocks were fed either a commercial diet or a Mn-supplemented diet containing 600, 900, and 1,800 mg/kg. The immune organs were collected at 30, 60, and 90 days, respectively, and the content of trace elements and the mRNA level of IL-1β and IL-2 were examined; the serum were collected and the IL-1β and IL-2 contents detected. The results showed that Mn content in immune organs increased and Fe, Zn, and Ca contents decreased; however, Cu and Se contents showed no difference. IL-1β and IL-2 mRNA levels and IL-1β and IL-2 contents decreased. The present study demonstrates that excess exposure to Mn results in metal accumulations in immune organs. Manganism can disturb the balance of trace elements in immune organs and induce immune suppression in the molecular level; therefore, the immune function of cocks are also suppressed after manganism.     

Molecular orbital studies on nucleoside antibiotics,VII. Conformation of 2′-amino- 2′-deoxyguanosine

Conformational properties of the nucleoside antibiotic 2-amino-2-deoxyguanosine have been investigated by the PCILO method along with those of its parent nucleoside, guanosine. This antibiotic, formed by replacement of the 2-hydroxyl group by an amino group in guanosine, shows anti-tumor activity and also inhibits RNA and protein syntheses. Both C(2)-endo and C(3)-endo sugar conformations have been considered in the computations. The results indicate striking similarity between the conformations of the antibiotic and the parent nucleoside, particularly in simulated aqueous environment. The biological implication of this result in terms of the antibiotic activity is discussed.     

Direct actions of prostaglandins E1, A1, and F2α on myocardial contraction

The inotropic and chronotropic actions of prostaglandin (PG) types PGE₁, PGA₁, and PGF_2α were studied in isolated guinea pig right and left atria, and papillary muscles; rabbit atria; and toad ventricular strips in order to more completely define the cardiac contractile properties of PG. All three prostaglandins, in muscle bath concentrations of 10μg/ml, exerted positive inotropic and chronotropic actions on guinea pig atrium. These contractile effects were persistent after removal of PG from the muscle bath and appeared to limit the relative response to a subsequent dose of PG. The inotropic action of PGE₁ was present over a wide range of bath calcium concentrations (1.1 to 4.4 mM/L). Beta adrenergic receptor blockade, histamine blockade, and pretreatment with reserpine failed to significantly affect the inotropic actions of PG. Norepinephrine and histamine produced more potent inotropic and chronotropic effects on guinea pig atria than did PG and these contractile effects did not exhibit persistence or tachyphylaxis. The prostaglandins did not significantly affect dose response curves for norepinephrine inotropic and chronotropic actions. The prostaglandins had no effect on the force or frequency of contraction in rabbit atria. PGE₁ exerted a positive inotropic effect on toad ventricular myocardium whereas PGA₁ had no effect and PGF_2α had a negative inotropic action.     

Computational Analysis of Cysteine Substitutions Modelled on the α- and β-domains of Cd5,Zn2-Metallothionein 2

Several mutant forms of rat liver Cd₅,Zn₂-metallothionein 2 (Cd₅,Zn₂-MT 2) [1] have been computationally modelled and analysed. All terminal cysteines (5, 13, 19, 21, 26, 29, 33, 36, 41, 48, 57 and 59, Figure 1) have been independently substituted by three other co-ordinating amino-acids (aspartate, glutamate and histidine), and the side-chains of the mutated residues have been modelled to co-ordinate the seven metal ions while minimizing the conformational variations with respect to the wild type protein. We have compared the ability of the putative mutant forms to maintain the MT binding properties. Substitution by aspartate residue best preserves the 3D MT structure. In addition, the mutations C5H plus C21H/E/D show neighbouring impairments that prevent their simultaneous substitution. Although replacement of cysteine by aspartate is feasible in all cases, to our knowledge there is no example of aspartate and cysteine residues co-ordinating to the same zinc atom. Accordingly, the use of histidine or glutamate instead of aspartate cannot be ruled out. The mutant forms in the -domain of Cd₅,Zn₂-MT 2 have yielded more neighbouring contacts than those in the -domain, which is corroborated by the accessible surface areas [2] of the sulfur atoms [3] in the native form.Abbreviations MT metallothionein - CD₅,Zn₂-MT Cadmium, Zinc-metallothionein - RMSD Root Mean Square Deviation - PDB Protein Data Bank - FEP Free Energy Perturbation - CnX mutant form of cysteine n (n = residue number) substituted by X (X = H, E or D, with H = histidine, E = glutamate, D = aspartate) - CnX/Y mutant forms CnX and CnY     

Impacts of Elevated CO2 Concentration on Biochemical Composition, Carbonic Anhydrase, and Nitrate Reductase Activity of Freshwater Green Algae

To investigate the biochemical response of freshwater green algae to elevated CO2 concentrations, Chlorella pyrenoidosa Chick and Chlamydomonas reinhardtii Dang cells were cultured at different CO2 concentrations within the range 3-186μmol/L and the biochemical composition, carbonic anhydrase (CA),and nitrate reductase activities of the cells were investigated. Chlorophylls (Chl), carotenoids, carbonhydrate,and protein contents were enhanced to varying extents with increasing CO2 concentration from 3-186μmol/L. The CO2 enrichment significantly increased the Chl a/Chl b ratio in ChloreUa pyrenoidosa, but not in Chlamydomonas reinhardtii. The CO2 concentration had significant effects on CA and nitrate reductase activity. Elevating CO2 concentration to 186μmol/L caused a decline in intracellular and extracellullar CA activity. Nitrate reductase activity, under either light or dark conditions, in C. reinhardtii and C. pyrenoidosa was also significantly decreased with CO2 enrichment. From this study, it can be concluded that CO2 enrichment can affect biochemical composition, CA, and nitrate reductase activity, and that the biochemical response was species dependent.     

Action of phospholipase A2 of rabbit neuronal and glial cells on 1,2-diacyl-, 2-acyl-1-alk-1′-enyl-, and 2-acyl-1-alkyl-glycerophosphatides

Pronounced differences in the phospholipase A₂ activities were found in neurons and glia, the enzyme activity being two- to threefold higher in neurons than in glial cells. Both phospholipases A₂ hydrolyzed the 1,2-diacylglycerophosphatides more rapidly than the acylalkyl and acylalkenyl compounds. Choline plasmalogen and the corresponding alkyl derivative were cleaved at similar rates by the phospholipase A₂ from both glia and neurons. There was a tendency by the neuronal phospholipase A₂ to release arachidonic acid faster than linolenic acid from both phosphatidylcholine and ethanolamine, while arachidonic acid was removed less actively from phosphatidylethanolamine by the glial enzyme. The glial phospholipase A₂ showed a lag period of 10 or 20 min. Norepinephrine, injected into the lateral ventricle of the rabbit brain, stimulated the hydrolysis of the various 1,2-diacyl-, acylalkyl-, and acylalkenyl-glycerophosphatides by the phospholipase A₂ from both glia and neurons.     

Studies on Glycosides of 3, 4, 6-Trisubstituted Pyrazolo-[3, 4-D]Pyrimidines. Synthesis of 2′-Deoxyribonucleosides

Abstract

A synthesis of 4,6-dimethylthio-1-(2-deoxy-β-D-erythro-pentofuranosyl)pyrazolo[3,4-d]pyrimidine-3-carbonitrile (4) is described using the stereospecific sodium salt glycosylation procedure. Condensation of the sodium salt of 4,6-dimethylthiopyrazolo[3,4-d]pyrimidine-3-carbonitrile (1) with 1-chloro-2-deoxy-3,5-di-O-p-toluoyl-α-D-eythro-pentofuranose (2) gave exclusively the corresponding blocked nucleoside (3) with β-anomeric configuration, which on deprotection provided 2′-deoxyriboside 4. Aglycone functional groups transformations of 4 led to related 3,4,6-trisubstituted pyrazolo[3,4-d]pyrimidine-2′-deoxynucleosides. These compounds are devoid of any significant cytotoxic activity in vitro.     

An inhibitory effect of RGD peptide on protein, priming reaction of bacteriophages ?29 and M2

Summary The amino acid sequence, arginine-glycine-aspartic acid (RGD), found in some cell adhesive proteins, is a recognition signal for the receptor protein. It is interesting that we have found the RGD sequence in terminal protein (TP) of bacteriophages 29 and M2 near an amino acid, the serine residue at 232, covalently linked to the terminal nucleotide of their DNAs. At the initiation of proteinprimed DNA replication, TP is essential for the recognition of replication machinery containing DNA polymerase and primer protein (PP; PP becomes TP upon linking the first nucleotide, and hence the primary structure of TP is the same as that of PP). Synthetic peptide RGD specifically inhibited transfection of 29 and M2. The target of the RGD peptide is shown to be TP by marker rescue experiments, suggesting that a receptor for the RGD sequence exists in TP. Furthermore, the peptide inhibited the in vitro protein-priming reaction of DNA replication. We propose that the RGD sequence of PP and a putative receptor on TP is utilized for the molecular recognition initiating DNA replication.     

Effects of prostaglandin F2α, cloprostenol and fenprostalene on uterine clearance of radiocolloid in the mare

Uterine clearance of radiocolloid was measured by scintigraphy in 5 reproductively normal mares and in 4 mares exhibiting a delay in uterine clearance (DUC) after administration of PGF_2α, cloprostenol or fenprostalene. Scintigraphy studies were performed on the second or third day of estrus during 3 consecutive estrous cycles. Drugs, PGF_2α (5 mg IM), cloprostenol (CLO; 2mg IM) or fenprostalene (FEN; 250 μg subcutaneously) were given in random order, with only 1 drug given each estrus. Treatment response curves were generated, and the effect of each drug on uterine clearance of radiocolloid was compared to the clearance of radiocolloid when no drug was given and between treatments. In reproductively normal mares, CLO and PGF caused a rapid clearance of radiocolloid within 60 min (P < 0.01), with <25% of the initial dose of radiocolloid (% IDR) remaining by 120 min. Mean percentage of IDR at 120 min when no drug was given was 39% ± 4. Response of reproductively normal mares to FEN varied, with 3 mares clearing > 85% and 2 mares clearing <35%. In mares exhibiting DUC, all 3 drugs (CLO, PGF and FEN) caused rapid clearance of radiocolloid from the uterus by 60 min (P < 0.0001). Mares cleared significantly more colloid after treatment with CLO at 60 and 120 min than after PGF (P < 0.001). In conclusion, CLO appears to be the best drug of the 3 tested for stimulating clearance of intrauterine fluid since variation in response was observed following treatment with PGF and FEN.     

Effects of Exogenous Zinc on Cell Cycle, Apoptosis and Viability of MDAMB231, HepG2 and 293 T Cells

As a non-toxic metal to humans, zinc is essential for cell proliferation, differentiation, regulation of DNA synthesis, genomic stability and mitosis. Zinc homeostasis in cells, which is crucial for normal cellular functioning, is maintained by various protein families including ZnT (zinc transporter/SLC30A) and ZIP (Zrt-, Irt-like proteins/SLC39A) that decrease and increase cytosolic zinc availability, respectively. In this study, we investigated the influences of a specific concentration range of ZnSO₄ on cell cycle and apoptosis by flow cytometry, and cell viability by MTT method in MDAMB231, HepG2 and 293 T cell lines. Fluorescent sensors NBD-TPEA and the counterstain for nuclei Hoechst 33342 were used to stain the treated cells for observing the localisation and amount of Zn²⁺ via laser scanning confocal microscope. It was found that the influence manners of ZnSO₄ on cell cycle, apoptosis and cell viability in various cell lines were different and corresponding to the changes of Zn²⁺ content of the three cell lines, respectively. The significant increase on intracelluar zinc content of MDAMB231 cells resulted in cell death, G1 and G2/M cell cycle arrest and increased apoptotic fraction. Additionally, the mRNA expression levels of ZnT and ZIP families in the three cell lines, when treated with high concentration of ZnSO₄, increased and decreased corresponding to their functions, respectively.     

Hormone studies inMyxine glutinosa: effects of the eicosanoids arachidonic acid,prostaglandin E1, E2, A2, F2α, thromboxane B2 and of indomethacin on plasma cortisol,blood pressure,urine flow and electrolyte balance

Summary Hagfish,Myxine glutinosa, were used in an investigation of the possible effects of various eicosanoids and the prostaglandin synthetase inhibitor indomethacin, on cortisol production, blood pressure control, urine flow and electrolyte balance.Cortisol levels in plasma of untreated control animals and plasma from animals 1 h following injection of 50 g kg^–1 prostaglandin E₁, E₂, A₂, F₂ TXB₂ and indomethacin were not detectable. However, plasma cortisol levels rose to between 10 and 26 pg ml^–1 1 h following injection of either 50 g kg^–1 arachidonic acid or prostaglandin E₂. This rise was similar in magnitude to that produced 1 h following administration of 50 g kg^–1 porcine ACTH.The resting dorsal aortic blood pressure of between 3.50 and 3.75 mmHg was reduced on average by 50% for 12–15 min when animals received 10 g kg^–1 arachidonic acid, prostaglandin E₁, E₂, A₂, and TXB₂ and was effectively reduced to zero for 20 min or more following 50 g kg^–1 of these eicosanoids. Similar doses of prostaglandin F₂, however, evoked an increase in blood pressure (19–33%) whilst indomethacin was without effect.Control measurements of urine flow inMyxine were estimated to be between 540 and 660 l h^–1 kg^–1. There was a marked reduction in urine output following the arterial vasodepression induced by arachidonic acid, prostaglandin E₁, E₂, A₂ and TXB₂ in doses of 10 g kg^–1, an effect which became even more pronouced following injection of 50 g kg^–1 quantities, leading in some cases to complete anuria. There was no significant change in urine volume following either the vasopressor action of prostaglandin F₂ or following indomethacin.None of the compounds tested in this study significantly influenced the plasma or urine electrolyte status ofMyxine.