Involvement of cPLA2 Inhibition in Dexamethasone-Induced Thymocyte Apoptosis

Various molecular mechanisms have been suggested to be involved in dexamethasone induced thymocyte apoptosis. In this study we show that pharmacological inhibition of cytoplasmic PLA2 in mouse thymocytes for 18 h with arachidonyl trifluoromethyl ketone (AACOCF3) (10 μM) and palmitoyl trifluoromethyl ketone (PACOCF3) (10 μM) induced a drastic increase of thymocyte apoptosis comparable to that observed following Dex (10−7 M) treatment, while inhibition of secretory PLA2 with p-bromophenacyl bromide (pBPB) (20 μM) did not. AACOCF3-induced thymocyte apoptosis, similarly to Dex-induced thymocyte apoptosis, was eliminated by cell pre-treatment with the PI-PLCβ inhibitor, U73122, but not by the PC-PLC inhibitor D609. These observations were corroborated by the ability of AACOCF3, like Dex, to induce a rapid and transient increase in DAG generation. In addition, AACOCF3-induced apoptosis involved the activation of the acidic sphingomyelinase (aSMase) but not of the neutral sphingomyelinase (nSMase), as evaluated by measurements of enzyme activity in cell extracts following thymocyte exposure to AACOCF3 and by the ability of monensin to inhibit AACOCF3-induced thymocyte apoptosis. In addition, the AACOCF3 apoptotic effect resulted in an early increase of ceramide levels. AACOCF3-induced thymocyte apoptosis involved the activation of caspase 3, and cell pre-treatment with a caspase 3 inhibitor prevented AACOCF3-induced apoptosis. These observations suggest that cPLA2 inhibition may have a role in Dex-induced thymocyte apoptosis and highlight the importance of cPLA2 activity in thymocyte survival.

Effect of Bifidobacterium infantis on Interferon- gamma- induced keratinocyte apoptosis: a potential therapeutic approach to skin immune abnormalities

Current management of atopic dermatitis is mainly directed to the reduction of cutaneous inflammation. Since patients with atopic dermatitis show abnormalities in immunoregulation, a therapy aimed to adjust their immune function could represent an alternative approach, particularly in the severe form of the disease. Indeed, T-lymphocytes constitute a large population of cellular infiltrate in atopic/allergic inflammation and a dysregulated T-cell induced keratinocyte apoptosis appears to be an important pathogenetic factor of the eczematous disease. In recent years, attention has been focused on the interaction between host and probiotics which may have anti-inflammatory properties and immunomodulatory activities. The aim of the present work is to investigate the effect of a selected probiotic extract, the Bifidobacterium infantis extract, on a human keratinocyte cell line (HaCaT) abnormal apoptosis induced by activated-T-lymphocyte. An in vitro model of atopic dermatitis was used to assess the ability of the probiotic extract to protect HaCaT from apoptosis induced by soluble factors (IFN-gamma and CD95 ligand) released by human T-lymphocytes in vitro activated with anti-CD3/CD28 mAbs or Phytohemoagglutinin. Evidence is given that the bacterial extract treatment was able to totally prevent T lymphocyte-induced HaCaT cell apoptosis in vitro. The mechanism underlying this inhibitory effect has been suggested to depend on the ability of the bacterial extract to significantly reduce anti-CD3/CD28 mAbs and mitogen-induced T-cell proliferation, IFN-gamma generation and CD95 ligand release. These preliminary results may represent an experimental basis for a potential therapeutic approach mainly targeting the skin disorders-associated immune abnormalities.

Behavioral effects of PCBs in mice

A single i.p. administration to mice of Fenclor 54 (PCB) resulted in various behavioral deficits. PCB significantly reduced locomotor activity and exploratory behavior at dosages of 150 and 300 mg/kg. Dose dependent increased latencies were also found at the same dosages in the "traction test" while in the rota rod test the dosage of 300 mg/kg of PCB only caused a significant increase in mean number of falls off the rod. Furthermore daily dietary administration of PCB (1, 10, 100 ppm) to male mice during a 21-day isolation period was inversely proportional to the amount of aggressive behavior shown, and directly proportional to the amount of non-social behavior ("indifference"). This supports former findings reporting anti-androgenic like effects of PCBs.

[Oral premedication with clonidine as an alternative in dental practice. The effects on the pain threshold, blood pressure and salivary flow]

BACKGROUND

Clonidine, an alpha 2-adrenoceptor agonist, has been recently shown to be effective in conscious sedation because of its analgesic and sedative properties, having also proven to be active in reducing neuroendocrine responses to stressful stimuli perioperatively. The current study was designed to investigate the efficacy of 150 micrograms oral clonidine as a premedicant in dentistry.

METHODS

In a prospective, randomized, double-blind controlled clinical trial, 40 patients, aged 16-64 yr, undergoing conservative, or prosthetic, or dental surgery procedures, received placebo (n = 20) or 150 micrograms of oral clonidine (n = 20) 90 min before the estimated time of induction of local anesthesia. A blinded observer recorded: salivary flow, systolic and diastolic blood pressure each 30 min lasting 2-3 hours, as well as the degree of pain and sedation intra and postoperatively.

RESULTS

Clonidine produced significant salivary flow reduction (p < 0.001) and sedation (p < 0.001) as well as significant difference in postoperative pain scores (p < 0.05) compared to placebo. Xerostomia persisted postoperatively in clonidine premedicated patients as compared to those given the placebo (p < 0.01). Systolic blood pressure decreased significantly only after 120 (p < 0.01) and 150 min (p < 0.001) following clonidine pretreatment, but none of the patients were treated for hypotension. 55% of the clonidine treated patients positively evaluated the experience.

CONCLUSIONS

These results suggest that a dose of 150 micrograms of clonidine, given orally 90 min preoperatively, is an effective premedication in dentistry, without causing excessive haemodynamic depression and sedation, and moreover confirm that the oral route of administration is very well accepted.

A new GABA-A receptor subtype coupled with Ca++/Cl- synporter modulates aminergic release from rat brain neuron terminals

The aim of the present study was to give a better characterization of GABA receptors that modulate aminergic release. GABA or muscimol (15 microM) increased basal noradrenaline (3H-NA) release but reduced the following K+-evoked 3H-NA release in the synaptosomes from rat cerebellar cortex. Bicuculline and picrotoxin counteracted these two effects. The same GABA modulation resulted to operate also on dopaminergic and serotoninergic neuron terminals. The increased basal noradrenaline release resulted to be both calcium and chloride dependent and associated with an increased entry of 45Ca++ into the synaptosomes. We therefore advance the hypothesis of an involvement of a Cl-/Ca++ synporter system coupled to the receptor. Baclofen also reduced the K+-evoked 3H-NA release, but did not increase basal 3H-NA release; moreover, the interaction of baclofen G with GABA-B receptors resulted to be associated with the inhibition of 45Ca++ entry into synaptosomes. GABA-B receptors resulted to be present also on serotoninergic but not on dopaminergic neuron terminals. The GABA-C receptor agonist cis-4-aminocrotonic acid (CACA) did not influence either basal or K+-evoked 3H-NA release. These results point to a new type of GABA functional role through a different A-family receptor subtype, coupled with calcium influx in aminergic neuron terminals, modulating aminergic release.

Simultaneous determination of 5-aminosalicylic acid, acetyl-5-aminosalicylic acid and 2,5-dihydroxybenzoic acid in endoscopic intestinal biopsy samples in humans by high-performance liquid chromatography with electrochemical detection

A high-performance liquid chromatographic method for the simultaneous determination of 5-aminosalicylic acid (5-ASA), acetyl-5-aminosalicylic acid (Ac-5-ASA) and 2,5-dihydroxybenzoic acid (5-HSA) in human endoscopic intestinal biopsy with electrochemical detection has been developed and validated. A liquid-liquid extraction procedure was used to isolate these drugs from the biological material prior to analysis. The compounds were separated on an Erbasil S reversed-phase column using methanol-critic acid-sodium hydrogenphosphate-heptane-sulfonic acid-disodium ethylenediaminetetraacetate (pH 3) as mobile phase. The method was linear from 1.0 to 300 ng ml-1 for 5-ASA, from 10 to 1000 ng ml-1 for Ac-5ASA and from 0.1 to 10 ng m-1 for 5-HSA. The limit of detection for 5-ASA and for Ac-5-ASA was 1 ng ml-1 and that for 5-HSA was 0.1 ng ml-1. This procedure is suitable for pharmacological and clinical studies of 5-ASA.

Determination of rufloxacin, a new tricyclic fluoroquinolone in biological fluids using high-performance liquid chromatography with ultraviolet detection

A simple, specific, and sensitive high-performance liquid chromatography method has been developed for routine monitoring of the antimicrobial agent rufloxacin in human serum and urine. Serum or urine-spiked with internal standard pipemidic acid, were vortex-mixed for 2 min with dichloromethane at pH 7.4. The evaporated extract was dissolved in 0.05 M NaOH. The mobile phase consisted of orthophosphoric acid, tetrabutylammonium iodide, and methanol. Drugs were resolved at ambient temperature on a 10 micron Viosfer LC-RP-18 column (250 x 4.6 mm I.D.) equipped with a guard column. Flow rate was 1.8 ml/min, and monitoring was performed at 295 nm. The calibration curve was linear from 0.1 to 10 micrograms/ml for human serum and from 0.05 to 10 micrograms/ml for urine. Retention times were 3.1 and 6.3 min for internal standard and rufloxacin. The detection limit of rufloxacin was 0.05 microgram/ml for human serum and 0.03 microgram/ml for urine. No interference from other commonly administered drugs or endogenous substances was observed. The assay demonstrated sufficient sensitivity and specificity for the study of the pharmacokinetics of rufloxacin in humans.

[5-Aroyl-5,6-dihydro-4H-pyrrolo[1,2-a][1,4]benzodiazepin-4-carboxylic acids: synthesis and analgesic and neurobehavioral activity]

Reaction between 1-(2-aminomethylphenyl)-1H-pyrrole hydrochloride and methyl 2-methoxyglicolate in methanol afforded methyl 5,6-dihydro-4H-pyrrolo[1,2-a][1,4]benzodiazepin-4-carboxylate. Aroylation at the 5-position and subsequent hydrolysis of the ester function led to 5-aroyl-5,6-dihydro-4H-pyrrolo[1,2-a][1,4]benzodiazepin-4-ca rboxylic acids. The pharmacological profile of these acids has been studied with regard to analgesic, antiinflammatory and neuropsychobehavioural effects.

Effects of maternal exposure to polychlorobiphenyls (PCBs) on F1 generation behavior in the rat

The effect of Fenclor 42 (PCB) exposure of female rats (Fischer 344 strain) was studied through assessment of the behavioral development of their F1 progeny. Female rats were exposed to PCB according to the following treatment schedule: (A) (5 days) 2 weeks prior to mating, (B) during gestation (Days 6-15 of pregnancy), (C) during lactation (Days 1-21 after delivery). Behavioral endpoints of motor reflexes, motor coordination, activity (preweaning behaviors), and learning (postweaning behavior) were evaluated for PCB ip dosages of 5-10 mg/kg/day for 5 days (preconception exposure), and PCB oral dosages of 2-4 mg/kg/day for 10 days (in utero exposure) and of 1-2 mg/kg/day for 20 days (during lactation exposure). Dosage-dependent differences in the evaluated behaviors were found in the offspring of the PCB-exposed females when compared to the offspring of corn-oil (vehicle)-exposed females. Significant differences in the development of cliff avoidance reflexive behavior, swimming ability, and open field activity were particularly evident. Furthermore the PCB exposure of female rats during gestation and lactation resulted in impaired acquisition of the active avoidance behavior while preconceptional PCB exposure significantly affected active avoidance performance as reflected in increased number of avoidance responses to reach criterion for extinction. These results show that Fenclor 42 does possess a significant risk to the offspring of exposed females, and further illustrate the sensitivity of progeny behavioral assessment in detecting suspected functional teratogenesis.

[Nonsteroidal anti-inflammatory agents. V. Synthesis of 1-aryl-5-(1-pyrryl)-pyrazolyl-4-acetic acids with potential anti-inflammatory action]

The synthesis of 1-aryl-5-(1-pyrryl)pyrazoles bearing at position 4 an acetic or alpha-propionic chain is described. The new compounds can be structurally related to lonazolac and its analogues with analgesic-antiinflammatory activities. When tested pharmacologically in comparison with tolmetin and indomethacin none of the above derivatives showed any appreciable activity.

[Non-steroidal anti-inflammatory agents. IV. Synthesis and pharmacologic activity of aroylthiopheneacetic acids with a pyrrole group]

The synthesis of new antiinflammatory aroylthiopheneacetic acids bearing a pyrrole moiety is described. These compounds can be regarded as analogues of thiaprofen and related isosteres. The antiinflammatory activity of the new pyrryl derivatives has been evaluated in comparison with indomethacin, tolmetin and the unknown 5-(2-chlorobenzoyl)thiophene-2-acetic acid. Among tested derivatives the compounds containing the pyrrole ring were devoid of analgesic-antiinflammatory activities.

[New psychotropic agents. 2. Synthesis and pharmacologic activity of derivatives of 5H-pyrrolo[1,2-b][1,2,5]benzotriazepines]

Bischler-Napieralski intramolecular cyclization of N-(2-aroylaminophenyl)-N-methyl-1H-pyrrol-1-amines and reaction of arylaldehydes on N-(2-aminophenyl)-N-methyl-1H-pyrrol-1-amine furnished 11-aryl-5-methyl-5H-pyrrolo[1,2-b][1,2,5]benzotriazepines and 11-aryl-10,11-dihydro-5-methyl-5H-pyrrolo[1,2-b][1,2,5]benzotriazepin es respectively. The latter reaction required in some cases the use of p-toluenesulphonic acid as a catalyst. The new tricyclic derivatives described were tested for pharmacological evaluation of their psychotropic activity.

Ethylene dibromide: effects of paternal exposure on the neurotransmitter enzymes in the developing brain of F1 progeny

The effects of ethylene dibromide (EDB) exposure to male rats on several neurotransmitter enzymes have been examined in various brain regions of the F1 progeny, from 7 to 90 days of age. The choline acetyltransferase activity was significantly increased at 21 days old, in most brain regions studied in the F1 progeny of the EDB-treated males, but not at 7, 14 or 90 days old. The acetylcholinesterase activity was altered in different brain regions of the F1 progeny of the EDB-exposed males at both 14 and 21 days old but not at 7 or 90 days old. Glutamic acid decarboxylase activity was increased in corpus striatum but decreased in frontal cortex only at 21 days of age. These neurochemical changes in the developing brain of F1 progeny of EDB-treated males at low doses may be associated with behavioral abnormalities observed early in their development.

[Non-steroidal anti-inflammatory agents. III. Synthesis and analgesic-anti-inflammatory activity of 4-(pyrrol-1-yl)phenylacetamides and 4-(pyrrol-1-yl)phenethylamines]

Preparation of some 4-(pyrrol-1-yl)phenylacetamides and 4-(pyrrol-1-yl)phenylethylamines starting from 4-(pyrrol-1-yl)phenylacetic acid is reported. The new compounds were tested as analgesic-antiinflammatory agents. Data from pharmacological screening indicate 1-[4-(pyrrol-1-yl)phenylethyl]piperidine as the most active substance.

[Heterocyclic systems. V. Synthesis and CNS activity of derivatives of 6H-pyrrolo (1,2-a) (1,4)-benzodiazepine]

The synthesis of new derivatives of 6H-pyrrolo[1,2-a] [1,4]benzodiazepine is described. These compounds were tested for activity on the C.N.S. by several screening tests on mice.

Effects of paternal ethylene dibromide exposure on F1 generation behavior in the rat

The effects of ethylene dibromide (EDB) exposure to the male rat were studied through behavioral assessments of their F1 progeny. Exposed males were bred with untreated female rats at 4 or 9 weeks after 5 daily EDB treatments. Behavioral assessment of motor reflexes and motor coordination were examined up to 21 days of age. Significant differences in the development of motor coordination and motor activity were observed in the F1 progeny of EDB-exposed males. These results support the evidence of EDB genotoxicity and further demonstrates the utility of behavioral end-points of the offspring as a sensitive means of assessing paternal reproductive risk.

[Heterocyclic systems. III. Synthesis and CNS activity of derivatives of pyrrole(2,1-c) (1,4)benzodiazocine]

5,11-Dioxo-1,2,3,5,6,11,12,12a-octahydropyrrolo [2,1-c] [1,4]benzodiazepine and the corresponding 2-hydroxyderivative were prepared by the intramolecular cyclization of 1-(2-aminophenylacetyl)pyrrolidin-2-carboxylic acid and 1-(2-aminophenylacetyl)-4-hydroxypyrrolidin-2-carboxylic acid; some of the tricyclic compounds were tested for neuropsychopharmacological effects.