Regulation by P2 agonists of the intracellular calcium concentration in epithelial cells freshly isolated from rat trachea

Epithelial cells were isolated from rat trachea by incubation of the organ in a calcium-free medium. The intracellular concentration of calcium ([Ca(2+)](i)) was measured with the calcium-sensitive fluorescent dye fura2. In resting conditions, the cells maintained a low [Ca(2+)](i) in spite of the presence of millimolar concentration of calcium in the incubation medium. These cells had retained intracellular stores of calcium which were emptied after exposure of the cells to thapsigargin, an inhibitor of intracellular calcium ATPases. Substance P (125 nM) transiently increased 2.5-fold the [Ca(2+)](i). ATP (1 mM) doubled the [Ca(2+)](i) after a few seconds and further induced a sustained increase of the [Ca(2+)](i). Coomassie blue fully blocked the response to ATP and extracellular magnesium only inhibited the delayed response to ATP. Among purinergic analogs, only benzoyl-ATP (Bz-ATP), an agonist on P2X ionotropic purinergic receptors, reproduced the response to ATP. UTP and 2-methylthioATP (two agonists on P2Y metabotropic purinergic receptors) transiently increased the [Ca(2+)](i). Thapsigargin, ATP and Bz-ATP increased the uptake of extracellular calcium. RT-PCR analysis revealed that two metabotropic receptors (P2Y(1) and P2Y(2)) and two ionotropic receptors (P2X(4) and P2X(7)) were expressed by the cells present in the suspension. It is concluded that purinergic agonists can modulate the response of rat tracheal epithelial cells by several mechanisms. The activation of metabotropic receptors should mobilize intracellular IP(3)-sensitive calcium pools. The activation of the ionotropic receptors should not only open a non-specific cation channel leading to the entry of calcium but should also induce the formation of pores in cells expressing the P2X(7) receptors, which could be deleterious to these cells.

Purines, a new class of agonists in salivary glands?

The response of rat submandibular glands to extracellular purines was tested. In crude cellular suspensions, ATP increased the [Ca2+]i mostly by promoting uptake of extracellular calcium. ATP caused the pHi to drop, a response blocked by chloride channel inhibitors. ATP also inhibited the basal and isoproterenol-stimulated activity of the Na+ -K+ -2Cl-cotransporter. These effects were reproduced by benzoyl-ATP, an agonist of ionotropic purinoceptors. In pure ductal suspensions, ATP activated a metabotropic P2Y1 purinergic receptor coupled to phospholipase C and opened a non-specific cation channel coupled to a P2X7 receptor. Activation of these receptors stimulated a Ca2+ -dependent and a Ca2+ -independent phospholipase A2, the latter resulting in kallikrein secretion. We conclude that purinergic agonists can modulate the activity of both acinar and ductal phases of secretion. Activation of metabotropic receptors coupled to phospholipase C could lead to responses resembling those to muscarinic or adrenergic agonists. Activation of ionotropic receptors could stimulate new intracellular responses also involved in secretory function.

Fatty acid profiles in pigmented and non-pigmented strains of S. marcescens

Wild, pigmented strains of Serratia marcescens and their non-pigmented mutants were compared on the basis of fatty acid profiles and lipid content. Classic biochemical tests show only minor differences, as well as fatty acid ratio C18:C16. The total amount of lipid synthesized and the saturated/unsaturated fatty acids ratio disclose a sharp total lipid reduction and a high percentage of unsaturated fatty acids in the pigmented strains, placing them in separated clusters compared with the nonpigmented mutants. It is hypothesized that the synthesis of the polyacetate required for the completion of the prodigiosin molecule may result in waste of methyl groups and thus affect the total amount of lipids.

Uptake and retention of Vibrio cholerae non-O1, Salmonella typhi, Escherichia coli and Vibrio harvey by mussels in seawater

Vibrio cholerae non O1 is known to persist in estuarine and freshwater environments. Experiments evaluated the amount of microorganisms accumulated in mussels maintained in static seawater, contaminated with 10(4) to 10(6) cells/ml and the depuration time required in circulating water. Accumulation and retention times were compared with those for Escherichia coli, Salmonella typhi and Vibrio harvey. E. coli and S. typhi accumulated to a greater extent and were released from mussels more quickly than vibrios which became undetectable 2 to 3 days later than E. coli. Seasonal seawater temperatures (14 to 21 degrees C) had a limited influence on depuration but vibrios appear to be retained with more efficacy over 16 degrees C while E. coli and S. typhi were eliminated to a greater extent. When mussels were contaminated with mixed culture, vibrios appeared to predominate on E. coli, while no interference was observed between E. coli and S. typhi.

[Chlamydia trachomatis conjunctivitis in the newborn]

Infections of the conjunctiva are frequent in the neonatal period. While Neisseria gonorrhoea and chemical agents were considered as the main etiologies of ophtalmiae neonatorum in the past, Chlamydia trachomatis is today a major cause of neonatal conjunctivitis. Thus in a study of 180 uni-or bilateral neonatal conjunctivitis the authors found a prevalence of Chlamydia trachomatis infection of 41%. The importance of the etiological diagnosis of neonatal conjunctivitis is emphasized, in order to define a specific treatment. Etiological diagnosis of Chlamydia trachomatis infection is based upon immunofluorescence and molecular diagnosis techniques (PCR, LCR). Prevention of neonatal Chlamydia trachomatis conjunctivitis relies upon screening and treatment of Chlamydia trachomatis infections in pregnant women and their partners. Treatment requires oral macrolides, the topical treatment being ineffective.

Nasopharyngeal electrode recording of somatosensory evoked potentials as an indicator in brain death

Median nerve somatosensory evoked potentials were recorded in 28 comatose patients, eight of whom were progressing from coma to eventual brain death and in 11 brain dead patients using electrodes over the scalp, neck and nasopharynx (nasopharyngeal electrode). This recording technique was used to assess the different derivation of brainstem P14 wave activity. It showed that in the midfrontal scalp to the nasopharynx derivation a clear P14 was present in all comatose patients. This component disappeared during the passage from coma to brain death. In a separate group, simultaneous direct recordings in the vicinity of the dorsal column nuclei and with a nasopharyngeal electrode were made in five patients undergoing neurosurgical procedures at the craniocervical junction with the same somatosensory evoked potential monitor. We found that the P14 recorded with the nasopharyngeal electrode in the neurosurgical patients corresponded in latency and morphology with the P14 recorded directly on the surface of the craniocervical junction and more specifically in the vicinity of the nucleus cuneatus. The nasopharyngeal electrode provides non-invasive access to the ventral brainstem at the medullo-pontine level and the disappearance of the P14 shows a clear sign of involvement of the craniocervical junction in brain dead patients. Our study showed that with a simple montage the nasopharyngeal electrode is an effective non-invasive monitor for brainstem activity and can be used as an early diagnostic indicator of brainstem death.

Calcium bioavailability and parathyroid hormone acute changes after oral intake of dairy and nondairy products in healthy volunteers

This study was designed to compare calcium bioavailability and serum parathyroid hormone acute changes after oral intake of 500 mg of elemental calcium from liquid milk, yogurt, calcium-citrate-enriched powdered milk or a calcium carbonate pill; or after intake of soybean imitation-milk. After a 12-h fast, blood samples were drawn both at baseline and 1, 2, 3 and 4 h after an oral intake of the above-mentioned products, which were ingested together with a light neutral breakfast. The administration order of the study products was randomly assigned to each of 19 healthy young volunteers (11 females, 8 males). The baseline serum concentrations of ionized calcium, phosphorus and intact parathyroid hormone (iPTH) were normal. Calcium-citrate-enriched powdered milk induced a significant increase in serum ionized calcium (p<0.001) and a significant and continuous decrease in serum iPTH concentration (p<0. 001). Yogurt and the calcium carbonate pill induced a similar but less significant effect, increasing serum ionized calcium (p<0.05) and decreasing serum iPTH (p<0.01). Liquid milk only induced a significant change in serum ionized calcium and iPTH concentration during the first 2 h; this effect was lost during the following 2 h. In conclusion, our study suggests the possibility that the addition of calcium citrate to powered milk may improve calcium bioavailability and enhance the inhibitory effect on serum iPTH in the assayed conditions.

alpha-Methyl-p-tyrosine inhibits latanoprost-induced melanogenesis in vitro

The PGF2alpha derivative, latanoprost, is a recent anti-glaucoma drug that has been reported to induce a discrete incidence of increased iris pigmentation in men. The present experiments were made in order to study whether this phenomenon could be influenced by the tyrosinase inhibitor, alpha-methyl-p-tyrosine. Melanin content, melanin production and tyrosinase activity of cultured uveal melanocytes derived from irides of brown or brown-blue color were measured after adding latanoprost at different molar concentration with or without alpha-methyl-p-tyrosine (10(-5)m). It was shown that latanoprost stimulated melanin content, melanin production and tyrosinase activity in a molar range between 10(-7) and 10(-5)m in uveal melanocytes derived from irides of both brown and brown-blue color. The effect seemed to be more pronounced in melanocytes derived from irides of brown-blue color. The adding of alpha-methyl-p-tyrosine completely prevented latanoprost-induced stimulation of melanin production in uveal melanocytes derived from irides of both colors. These results suggest that latanoprost-induced stimulation of melanin production, follows the metabolic pathway involving tyrosinase activity and may be relevant for the therapeutic application of latanoprost in glaucoma in order to reduce its side-effect resulting in increased iris pigmentation.

Activation by P2X7 agonists of two phospholipases A2 (PLA2) in ductal cells of rat submandibular gland. Coupling of the calcium-independent PLA2 with kallikrein secretion

Isolated ductal cells of rat submandibular gland phospholipid pools were labeled with [3H]arachidonic acid (AA). The tracer was incorporated preferentially to phosphatidylcholine (46% of the lipidic fraction). Extracellular ATP induced the release of [3H]AA to the extracellular medium in a time- and dose-dependent manner (EC50 = 220 microM). Among other agents tested, only 2', 3'-O-(4-benzoylbenzoyl)adenosine 5'-triphosphate (Bz-ATP) was able to mimic the effect of ATP (EC50 = 15 microM), without activation of phospholipase C. The purinergic antagonists oxidized ATP, suramin, and Coomassie Blue partly inhibited the response to 1 mM ATP and 100 microM Bz-ATP; the response was also blocked by the addition of Mg2+ or Ni2+. Expression of P2X7 receptor mRNA in these cells was confirmed by reverse transcription-polymerase chain reaction. In the presence of extracellular calcium, the phospholipase A2 inhibitor 2-(p-amylcinnamoyl)amino-4-chlorobenzoic acid (a nonspecific inhibitor), arachidonyl trifluoromethylketone (AACOCF3, an inhibitor of the calcium-dependent cytosolic PLA2 (cPLA2)), and bromoenol lactone (an inhibitor of the calcium-independent PLA2 (iPLA2)) inhibited the release of [3H]AA induced by ATP and Bz-ATP. In the absence of extracellular calcium, the release of [3H]AA in response to the purinergic agonists was still observed; this response was not affected by AACOCF3 and completely blocked by bromoenol lactone. ATP and Bz-ATP stimulated a calcium-independent secretion of kallikrein, which could be blocked by BEL but which was enhanced by AACOCF3. It is concluded that the P2X7 receptor in ductal cells is coupled to kallikrein secretion through a calcium-dependent cPLA2 and a calcium-independent iPLA2.

Do quantitative changes in pain intensity correlate with pain relief and satisfaction?

OBJECTIVE

To correlate measured pain intensity (PI) changes with pain relief and satisfaction with pain management.

METHODS

A prospective single-group repeated-measures design study. A heterogeneous group of patients were asked to record their levels of PI at initial presentation and at ED release using a numerical descriptor scale (NDS) and a visual analog scale (VAS). At release, a 5-point pain relief scale and a pain management satisfaction survey were also completed.

RESULTS

A convenience sample of 81 patients were enrolled over the study period. The average reduction in PI for all patients was 33%. A 5%, 30%, and 57% reduction in PI correlated with "no," "some/partial," and "significant/complete" relief, respectively (p < 0.001). However, when patients were divided into 2 groups based on their initial PI scores, patients with moderate/severe pain (NDS > 5) required a reduction of 35% and 84% in PI to achieve "some/partial" and "significant/complete" relief, respectively. Patients in less pain (NDS < or = 5) needed 25% and 29% reductions in PI for the same categories (p=0.8). Patients were generally satisfied with their pain management. There was a positive association between pain relief and satisfaction with pain management.

CONCLUSION

There is a significant association between changes in PI and pain relief. Greater reductions in PI are required for patients presenting with more severe initial pain to achieve relief compared with those who have lesser initial PI. While there is a linear relationship between increasing pain relief and satisfaction, relief of pain appears to only partially contribute to overall satisfaction with pain management.

Effects of sulfinpyrazone on retinal damage induced by experimental diabetes mellitus in rabbits

The protective activity of the phenylbutazone derivative, sulfinpyrazone on retinal lesions has been assessed in rabbits with severe streptozotocin-induced diabetes. Sulfinpyrazone (8 mg kg-1 per day per os) was administered in diabetic animals in two different experimental procedures: for 135 days in a preventive approach (beginning on the day of initial hyperglicaemia); and for 30 days in a therapeutic approach (beginning on the day of appearance of severe retinal damage). The drug treatment made either with the preventive or the therapeutic approach reduced the incidence of serious retinal lesions and increased that of light lesions as assessed by a biomicroscopic method. Biochemical analyses showed that experimental diabetes was accompanied by sustained decrease in glucose and pyruvate and an increase of the lactate content in the retina. A decrease of alpha-ketoglutarate and citrate and an increase of succinate were also observed along with a decrease of ATP, ADP and an increase in AMP. Either the preventive or the therapeutic approach was followed by an increased pyruvate and ATP content and decreased lactate and AMP content in the retinal tissue. It is possible that this drug acts on the retinal tissue by inhibiting platelet aggregation and protecting vasal endothelium with the consequent suppression of the release of vasoactive substances that facilitate platelet adhesion.

Differential sensitivity to nickel and SK&F96365 of second messenger-operated and receptor-operated calcium channels in rat submandibular ductal cells

The intracellular concentration of calcium ([Ca2+]i) of rat submandibular ductal cells was measured with the intracellular fluorescent dye Fura-2. Carbachol (100 microM) and ATP (1 mM) both increased the [Ca2+]i. The late response to ATP was blocked by 0.5 mM Ni2+. This concentration of Ni2+ also blocked the increase of the [Ca2+]i and the uptake of manganese and calcium in response to 2'- and 3'-O-(4-benzoylbenzoyl) adenosine 5'-triphosphate (BzATP, 100 microM), a specific agonist of P2X receptors from salivary glands. The increase of the [Ca2+]i in response to 2-methylthioadenosine 5'-triphosphate (2-MeSATP, 100 microM) a specific P2Y agonist in salivary glands or to a muscarinic agonist (carbachol) was not affected by 0.5 mM Ni2+. Only higher concentrations of Ni2+ (in the millimolar range) inhibited the uptake of extracellular calcium in response to carbachol. SK&F96365, a blocker of store-operated calcium channels, inhibited the uptake of extracellular calcium in response to carbachol without affecting the response to BzATP. It is concluded that at low concentrations (below 0.5 mM), Ni2+ inhibits the non-specific cation channel coupled to P2X receptors. The uptake of extracellular calcium by store-operated calcium channels is inhibited by higher concentrations of Ni2+ and by SK&F96365.

Determination of aryloxyphenoxypropionic acid herbicides in water using different solid-phase extraction procedures and liquid chromatography-diode array detection

For isolation and trace enrichment of aryloxyphenoxypropionic acid (ArPP) herbicides from drinking, spring, and ground water a sensitive, robust method is presented. A 1-2 1 volume of aqueous samples was passed through a disposable solid-phase extraction cartridge, packed with 500 mg of Carbograph-1 at a flow-rate of 100 ml/min. After washing, ArPPs are selectively eluted with 8 ml of dichloromethane-methanol (80:20, v/v) with 50 mmol/1 formic acid and evaporated to dryness. The mixture was reconstituted with 250 microliters of water-acetonitrile (75:25; v/v) acidified with 0.1% trifluoroacetic acid and 100 microliters was injected into the high-performance liquid chromatography system. The ArPPs were separated via a binary gradient of water and a mixture of methanol-acetonitrile. Detection and confirmation were performed by diode array detection. Recovery of the six acid herbicides ranged between 90% and 98%. The limits of detection of ArPPs were 7-20 ng/l for drinking water and 16-36 ng/l for spring water. In terms of recovery and selectivity the effectiveness of Carbograph-1 cartridges was compared with that of LiChrolut-EN cartridges and polystyrene-divinylbenzene Empore disks. Relevant parameters such as pH and flow-rate for solid-phase extraction with divinylbenzene resins were optimized.

Activation of the Na+-K+(NH4+)-2Cl(-)- cotransporter from rat submandibular glands in response to VIP

A cellular suspension from rat submandibular glands was prepared with collagenase. The intracellular pH (pHi) was estimated with 2',7'-bis-(2-carboxy-ethyl)-5(6)-carboxyfluorescein (BCECF). After exposure to NH4Cl, the pHi transiently increased (diffusion of NH3) and then dropped (influx of NH4+). Isoproterenol increased 2.5-fold the rate of NH4+ influx; bumetanide, an inhibitor of the Na+-K+-2Cl(-)-cotransporter blocked the response to isoproterenol, confirming that the beta-adrenergic agonist stimulated the cotransporter. Forskolin (1 micromol/L) mimicked the response to isoproterenol. VIP (1 nmol/L(-1) micromol/L) also increased the activity of the cotransporter. Cyclic AMP rather than calcium was the mediator of this activation since 1) carbachol which increased the [Ca2+]i fivefold increased the uptake of NH4+ by only 50%; 2) only high concentrations of VIP significantly increased the [Ca2+]i; 3) incubation in the presence of EGTA had no effect on the response to VIP; 4) low concentrations (nmol/L) of the neuropeptide increased the intracellular level of cAMP; and 5) the stimulation of the cotransporter by VIP, forskolin, and isoproterenol was inhibited by H8, an inhibitor of cAMP-dependent protein kinase. It is concluded that the Na+-K+-2Cl(-)-cotransporter of rat submandibular glands is activated by isoproterenol, forskolin, and neuropeptides of the VIP family by a mechanism involving cAMP-dependent processes. The activation of the cotransporter by VIP could partly explain the potentiating effect of VIP on the response to sialagogues like substance P or muscarinic agonists.

Use of a microquantity enzyme immunoassay in a large-scale study of measles, mumps and rubella immunity in Italy

The seroprevalence of antibodies to measles, mumps, and rubella viruses (MMR) was determined in 1498 subjects in Catania, Italy, ranging in age from 1 month to 25 years. The study population was divided into seven age groups and screened by enzyme immunoassay using microquantities (10 microl) of whole blood collected by fingerprick on filter paper discs. The results showed that seroconversion for measles (87.6%) and mumps (73.2%) occurred between 6 and 10 years of age. The seroprevalence of antibodies to rubella virus increased slowly through the age groups, reaching the highest rate (93.3%) between 16 and 20 years of age. Passively transmitted maternal antibodies to mumps and rubella were absent in babies between 5 and 8 months of age, and a few cases positive for measles antibodies were found among babies 6 and 7 months of age. The enzyme immunoassay was demonstrated to be suitable for low-cost large-scale screening for MMR immunity. The rate of vaccine failure was also evaluated and found to be 9.5% for the measles virus, 12.9% for the mumps virus and 0.0% for the rubella virus.

Simultaneous determination of imidazolinone herbicides from soil and natural waters using soil column extraction and off-line solid-phase extraction followed by liquid chromatography with UV detection or liquid chromatography/electrospray mass spectroscopy

This paper describes the simultaneous quantification of the imidazolinone herbicides (IMIs) imazapyr, m-imazamethabenz, p-imazamethabenz, m,p-imazamethabenz-methyl, imazethapyr, and imazaquin in two types of samples. (a) Groundwater, lake water, and river water samples were enriched by off-line solid-phase extraction with a Carbograph-1 cartridge and analyzed by reversed-phase liquid chromatography using a UV detector (lambda = 240 nm). The overall recoveries of IMIs extracted from 1 L of groundwater (fortified with 500-100 ng/L), 0.5 L of lake water (fortified with 500-100 ng/L), and 0.5 L of river water (fortified with 1000-200 ng/L) samples were not lower than 89%. The mean relative standard deviation (RSD) was 5.1% (ranging from 4.1% to 6.8%) in natural water. The detection limits were 30-39 ng/L in groundwater, 43-51 ng/L in lake water, and 55-67 ng/L in river water. The method involves confirmatory analysis by LC/ES-MS in full-scan mode. The dependence of the ion signal intensities on proton concentration in the mobile phase was investigated with a view to optimizing the sensitivity of the ES-MS detector. When LC/ES-MS was used, the limit of detection, calculated from extracted-ion current profiles (EICPs), was 4-7 ng/L for ground-water and 9-13 ng/L for river water. (b) Soil sample analysis utilized combined soil column extraction (SCE) and off-line solid phase extraction (SPE) for sample preparation, analyzing with LC/ES-MS under selected ion monitoring (SIM). Several different extractants were evaluated for the purpose of SCE optimization. The system that best optimizes the extractability IMIs from the soil was found to be the mixture CH3OH/(NH4)2CO3 (0.1 M, 50:50 v/v). The effect of IMI concentration in the matrix on recovery was evaluated. The total recovery of each IMI from soil at each of the two levels investigated ranged from 87% to 95%. Under three ion SIM conditions, the limit of detection (S/N = 3) was 0.1-0.05 ng/g in soil samples.

Percept-genesis of the mother-child separation theme among panic and asthma patients

A stimulus portraying a mother figure who is leaving a baby alone on the floor (Separation Theme) was presented tachistoscopically at increasing exposure times, according to the method of the Defense Mechanism Test, to three sex-matched groups of 31 normal subjects, 31 patients with bronchial asthma, and 31 patients with Panic Disorder and Agoraphobia. The frequency of several codings was significantly higher in both clinical groups compared with normal controls. Asthma patients were characterized by reports of the child seen as a statue and of contact or fusion between mother and child. Agoraphobic patients employed different strategies, centered on the mother rather than on the child and mainly represented by the denial of mother's action, e.g., she is not leaving, she is entering. The findings support the hypothesis of a difference in defensive organization between neurotic and psychosomatic patients.

Characterization of specific corticosterone binding sites in adrenal cortex plasma membrane and their localization by autoradiographic studies

Specific corticosterone binding to calf adrenal cortex plasma membrane was measured using the biologically active radioligand [3H]corticosterone. Corticosterone binding was found to be time-dependent, saturable and reversible, and was reduced by more than 70% when membranes were pretreated with proteases. The population of corticosterone binding sites in calf adrenal cortex plasma membrane was homogeneous and displayed the following characteristics: equilibrium dissociation constant Kd = 77 +/- 8 nM and maximum specific binding capacity Bmax = 70,378 +/- 6,385 fmol/mg protein. The relative affinities of several structural analogues of steroids were deduced from competition assays. From these experiments we can conclude that the plasma membrane binding site characterized is selective for corticosterone and progesterone derivatives, and different from nuclear glucocorticoid, mineralocorticoid, estrogen and progestin receptors. Likewise, this corticosterone binding site is independent of mineralocorticoid and Na+, K(+)-ATPase digitalis receptors. From autoradiographic studies we suggest these corticosterone binding sites are located in the whole adrenal cortex.