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Biomedical subjects

F A Curro

Publications and source records attributed to F A Curro.

At least 19 recordsLinked to original sources
PubMed1992

Clinical effectiveness of a dentifrice containing potassium chloride as a desensitizing agent.

Sensodyne F, a dentifrice currently marketed in the United Kingdom, containing potassium chloride (KCl) and sodium monofluorophosphate (MFP) was compared to a placebo dentifrice for effectiveness in alleviating dentinal hypersensitivity. This randomized, double-blind, parallel clinical study covered 12 weeks of product use by 41 subjects. Hypersensitivity levels of the affected teeth were assessed by tactile stimulation, cold air stimulation and overall subjective patient response. The results from these three methods of assessment demonstrated that the KCl/MFP dentifrice was significantly more effective than the placebo dentifrice in reducing dentinal hypersensitivity. The therapeutic response to the KCl/MFP dentifrice as measured by air sensitivity and overall subjective evaluation was statistically significant when compared to the placebo dentifrice within 4 weeks of use. Significant improvement was observed for all parameters at the conclusion of the 12-week clinical study period. Plaque reduction was significantly reduced at week 8 and continued to improve by week 12. The results indicate that KCl with sodium MFP significantly reduced dentinal hypersensitivity and improved overall patient comfort.

Adolescent↗
PubMed1991

Bioavailability of aspirin and salicylamide following oral co-administration in human volunteers.

BC powder (I) is a commercially available analgesic containing the active ingredients aspirin and salicylamide. The kinetics of I, BC powder minus aspirin (II), and BC powder minus salicylamide (III) were evaluated in 13 volunteers. Ten minutes after administration of I, aspirin reached a maximum concentration of 12.9 micrograms/mL, while salicylamide concentration reached a peak value of 3.4 micrograms/mL. However, when III was administered, aspirin was not detected at 10 min and only reached a concentration of 0.4 microgram/mL at 2 and 6 h. Furthermore, the area under the plasma concentration versus time curve for aspirin when III was administered was sixfold less compared with treatment with I. The area under the curve for aspirin metabolites was significantly different in I versus III. After treatment with II, a delay in salicylamide peak concentration was observed. Gentisamide was not detected throughout the study. This study demonstrates that salicylamide significantly enhances plasma levels of aspirin with potential therapeutic implications.

Adult↗
PubMed1991

The effect of thromboxane on contraction of canine mesenteric and lingual arteries.

Thromboxane A2 (TXA2), a potent vasoconstrictor agent, is released from platelets and smooth muscle during inflammation and trauma. TXA2 may cause lingual artery (LA) contraction, leading to lingual paresthesia. The effects of U-46619, a TxA2 mimetic, on isolated rings of canine LA and mesenteric artery (MA) were examined. U-46619 (1 nmol/L to 1 mumol/L) caused a triphasic contraction of LA and MA; a rapid, phasic contraction; a slow, sustained contraction; and, upon washout of U-46619, a maintained contraction. The MA relaxed slowly, but the LA remained contracted for at least three h after washout. Decreasing extracellular calcium ion (Ca2+o) to less than 0.1 mumol/L with 2 mmol/L EGTA relaxed MA, but not LA. EGTA (4 mmol/L) partially relaxed the maintained contraction of LA. Inhibition of protein kinase C with amphotericin B or staurosporine inhibited the phasic and sustained contractions of LA, but did not affect the maintained contraction in the presence or absence of EGTA. Thus, CA2+o was required for the initial contraction of the LA by U-46619, but did not appear to be required for the maintained contraction following washout of U-46619. The data support the conclusion that following a brief exposure to U-46619, maintained contraction of LA persists by a unique mechanism that may be independent of Ca2+ and protein kinase C. Sustained LA contraction after exposure to endogenous TXA2 during inflammation and trauma may contribute to impaired lingual blood flow and orofacial tissue injury.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1990

Tooth hypersensitivity in the spectrum of pain.

Dentinal hypersensitivity satisfies all the criteria to be classified as a true pain syndrome that can be acute, but for our purposes is a chronic condition with acute episodes without the disabling characteristics and severe dysfunction of a chronic pain syndrome. It is estimated that the frequency of dentinal hypersensitivity affects one of six people, and one or more teeth can be affected. The incidence of dentinal hypersensitivity appears to peak around the third decade of life and may appear as root sensitivity in the fifth decade of life as root sensitivity particularly in patients undergoing periodontal surgery. The relationship of dentinal hypersensitivity to acute and chronic pain is shown in Table 1. Dentists' ability to soothe or stop pain has always been their greatest asset in establishing patient rapport. The experience of pain is so subjective that none of us can ever be sure another person is having it. Physicians, dentists, and especially those affiliated with pain centers and clinics have resolved this dilemma in a commonsensical way. They simply treat the pain as if it were real, and their track record in confronting this inscrutable condition has contributed to their high regard as professionals.

Acute Disease↗
PubMed1989

Toothbrush bristle density: relationship to plaque removal.

A double-blind, parallel, controlled study was conducted to determine the effect of toothbrush bristle density (total number of bristles divided by the brush head area) in removing plaque from tooth surfaces. Ninety subjects (29 males, 61 females), aged 18-65, were randomly assigned to one of three groups using the Sensodyne Search 4-Rowa toothbrush modified to have the following bristle densities: A (4.5 bristles per mm2); B (8.3 bristles per mm2); or C (11.8 bristles per mm2). The average trim height of the bristles was 10.77 mm. Subjects brushed without any dentifrice once a day for 7 days in order for adherent deposits (salivary pellicle and plaque remnants) to accumulate on their teeth. On the eight day, examinations for stained deposits were performed according to the Global Scoring Index before and after one minute of brushing with a commercially available toothpaste. Percent reductions in deposits were highly significant for the eighty-seven subjects who completed the study. A paired t-test between the pre- and post-treatment scores (p = 0.005) demonstrated the following: Toothbrushes A, B and C had reductions in plaque of 45.5%, 51.9% and 56.8%, respectively. On an overall basis, the intergroup percent reductions were significantly different using ANOVA (p = 0.001), and demonstrated a relationship in terms of data clustering for percent plaque removal of toothbrushes with varied bristle densities.

Adolescent↗
PubMed1986

Stimulation of cAMP accumulation in rat aorta and diaphragm by fluorine containing compounds.

Evidence is presented that accumulation of cAMP in isolated rat thoracic aorta and diaphragm is stimulated by several fluorine containing compounds (NaF, Na2PO3F (MFP) and SnF2). Time course experiments with NaF showed that maximal stimulation of cAMP accumulation was observed within 2.5 min. NaF and MFP produced significant increases in cAMP accumulation at concentrations of 0.1 microM and SnF2 produced a significant increase at 0.01 microM. The sensitivity of these tissues to the fluorine compounds is similar to that previously reported (Curro and Mickunas, 1981) for the inhibition of norepinephrine induced contractions by fluorine compounds in isolated thoracic aorta.

Animals↗
PubMed1985

Toxicological assessment of lidocaine in the pregnant rat.

Teratogenic and toxicological effects of lidocaine administered during pregnancy were evaluated in the Sprague Dawley rat. High doses of lidocaine administered during specific periods of gestation were shown to produce no apparent adverse toxicological or teratogenic effects. Histological, enzymological, and physical features of the fetuses, utilizing conventional toxicological parameters, were all found to be normal following maternal administration of lidocaine. Analysis of these data suggests that the administration of lidocaine during pregnancy had no detectable adverse effects on the fetus.

Animals↗
PubMed1983

Characteristics of postsynaptic alpha 1 and alpha 2 adrenergic receptors in canine vascular smooth muscle.

A previous study suggested the existence of two distinct postsynaptic alpha adrenergic receptors in canine intralobar pulmonary arteries (IPA) and veins. The present study, performed using rings of canine IPA and dorsal metatarsal vein (DMV), was designed to characterize the factors affecting the postsynaptic alpha 1 and alpha 2 receptors of these blood vessels. The responses of IPA and DMV to norepinephrine (NE), transmural nerve stimulation, phenylephrine (PE), guanabenz, and clonidine were obtained in the presence and absence of alterations in pH, extracellular calcium ion, sulfhydryl bond reduction and oxidation, and destruction of adrenergic nerves with 6-hydroxydopamine. The data demonstrate that: (i) alpha 2-receptors are inactivated by changes in pH above or below pH 7.4, contain a labile disulfide group, are susceptible to modulation by increases and decreases in calcium ion, and appear to be decreased by destruction of adrenergic nerves; (ii) the NE and PE sensitive alpha 1-receptors are insensitive to alterations in pH, refractory to disulfide reduction by dithiothreitol, slightly susceptible to modulation by calcium ion, and increased by destruction of adrenergic nerves. These data support the conclusion that the two subtypes of postsynaptic alpha adrenergic receptors differ in their properties and susceptibility to modification by alteration of the physiological environment.

Animals↗
PubMed1983

Differences in adrenergic receptor populations in canine dorsal metatarsal veins and intralobar pulmonary arteries.

The contractile responses of the canine intralobar pulmonary arteries (IPA) and dorsal metatarsal veins (DMV) to alpha adrenergic receptor agonists were evaluated in the absence and presence of alpha receptor antagonists to determine the type of post-synaptic alpha receptor predominant in the cutaneous and pulmonary canine vasculature. Rings of IPA, in vitro, contracted in response to the alpha 1 receptor agonist phenylephrine (PE), and the mixed alpha agonist norepinephrine (NE) but did not contract in response to clonidine (C), an alpha 2 receptor agonist. DMV contracted in response to each of the agonists. The contractile responses of the IPA to NE and PE were antagonized by tolazoline, phentolamine, clonidine and prazosin. The contractile responses of the DMV to clonidine were only antagonized by clonidine and phentolamine but not by tolazoline or prazosin. These data suggest that: 1) IPA are selectively endowed with post-synaptic alpha 1 adrenergic receptors; 2) DMV are endowed with both post-synaptic alpha 1 and alpha 2 adrenergic receptors; and 3) clonidine interacts with alpha 1 adrenergic receptors to elicit alpha blockade and with alpha 2 adrenergic receptors to initiate contraction of the DMV. In an attempt to verify this hypothesis, experiments were performed in solutions in which the pH was altered above or below pH 7.4. Under these conditions, the agonist properties of clonidine were selectively inhibited whereas its blocking potency was retained. These data support the conclusion that clonidine is antagonistic at alpha 1 adrenergic receptors and agonistic at alpha 2 adrenergic receptors.

Adrenergic alpha-Agonists↗
PubMed1983

Differential inhibition of 5-hydroxytryptamine (5-HT) mediated contraction of rat thoracic aortae by phentolamine and tolazoline: correlation with inhibition of 5-HT binding and calcium ion.

The contribution of alpha receptor stimulation to the contractile responses of vascular smooth muscle to 5-HT was evaluated, in vitro utilizing helical strips of rat thoracic aortae (RTA). The contractile responses of RTA to 5-HT and norepinephrine (NE) were inhibited by the alpha receptor blocking agent phentolamine. The inhibition persisted in RTA obtained from rats treated with reserpine (1.5 mg/kg/day for 6 days). Analysis of the interaction of phentolamine with 5-HT and NE demonstrated that: 1) phentolamine is a competitive inhibitor of the responses to 5-HT; and 2) the pA2 values for the interaction of phentolamine with 5-HT and NE differed. When the concentration of calcium ion in the physiologic saline solution (PSS) was increased from 1.6 mM to 2.5 mM, phentolamine was approximately 100 times more potent an inhibitor of the response to NE than 5-HT. Phentolamine decreased the binding of 14C-5-HT to rat thoracic aortae in control PSS, but not when the calcium concentration was increased to 2.5 mM. Tolazoline inhibited the contractile responses of RTA to NE but not 5-HT. The data support the conclusion that the contractile responses of RTA to 5-HT are mediated by receptors similar to the alpha receptor. The ability of phentolamine to inhibit 5-HT induced contraction may be dependent on the ability of phentolamine to bind to anionic sites of the 5-HT receptor. The inhibitory effect of calcium ion may result from its ability to combine with, and neutralize, these negatively charged moieties on the smooth muscle membrane. The lack of effect of tolazoline may result from the absence of the third ring structure present in the phentolamine molecule, and therefore an inability to bind to these postulated anionic sites. Alternatively, the absence of an imino-nitrogen in the chain separating the phenyl and imidazole groups of tolazoline may prevent tolazoline from interacting with the 5-HT receptor. The different pA2 values for phentolamine mediated inhibition of the responses to 5-HT and NE, and the ability of NE to poorly displace 5-HT from the RTA, despite blockade of alpha receptors with tolazoline, support the possibility that the 5-HT receptor of RTA differs from the alpha receptor and that phentolamine has affinity for both 5-HT and adrenergic receptors.

Animals↗
PubMed1978

Interaction between alpha adrenergic and serotonergic activation of canine saphenous veins.

Serotonin and norepinephrine produced concentration-dependent contractions of helical strips of canine saphenous veins. The contractile responses to both agonists were inhibited by the alpha adrenergic receptor blocking agent phentolamine. Tolazoline inhibited the contractile responses of canine saphenous veins to norepinephrine but augmented those to serotonin. Blockade of adrenergic neuronal reuptake with cocaine enhanced the sensitivity of the canine saphenous vein to serotonin, but did not suppress the inhibition by phentolamine of the contractile responses to this indolealkylamine. Serotonin-mediated venoconstriction was not secondary to release of norepinephrine since it was not accompanied by an increased release of [7-3H]-norepinephrine. These findings suggest that serotonin does not contract canine saphenous veins by stimulation of typical serotonergic receptors. The binding sites for serotonin and norepinephrine in cutaneous venous smooth muscle may share part of a common receptor complex, which triggers the contractile process. Alternatively, serotonin and norepinephrine may act at two different receptors to elicit contraction of canine saphenous veins.

Animals↗