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A Chiarenza

Publications and source records attributed to A Chiarenza.

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Effects of cadmium on the function and structure of the rat salivary glands.

The effects of sub-chronic cadmium (Cd) administration on the structure and subsequent secretory responses of the submaxillary and parotid glands to sialagogues were investigated. Female Wistar rats were injected subcutaneously with cadmium chloride (3.0 mg/kg body weight), 4 times a week for 2, 3 or 4 weeks. Functional and histopathological studies were done 3 days after the last injection. Dose-response curves for norepinephrine and methacholine were obtained. After 2 weeks of Cd administration significant changes in the secretory response to these sialogogues were observed. The dose-response curves after pretreatment with Cd for 3 weeks were also shifted to the right, but the response showed recovery when compared with that of 2-week treated animals. Parotid amylase concentration was also diminished by Cd. Treated rats had reduced acinar diameters, and an increase in acinar cell nuclei per field in both the submaxillary and parotid glands. Thus sub-chronic administration of ionized Cd produces morphological and functional changes in rat salivary glands. Moreover, the extent of tubular and acinar damage matches the degree of gland dysfunction as judged by the diminution of secretory responses to sialagogues.

Amylases

Arachidonic acid metabolites modulate rat hypothalamic corticotropin-releasing hormone secretion in vitro.

Arachidonic acid metabolites have been shown to modulate the secretion of various hormones, including luteinizing hormone, growth hormone and adrenocorticotropin. In this paper we describe the effect of a series of eicosanoids on hypothalamic secretion of corticotropin-releasing hormone (CRH) in vitro. Explanted rat hypothalami in culture were exposed to prostaglandins (PG) F2 alpha or E2, thromboxane (TX) B2, the TXA2 receptor agonist U-49,619 and leukotrienes (LT) B4, C4 and D4 at concentrations ranging from 10(-15) to 10(-5) M. PGE2, LTD4 and TXB2 did not alter hypothalamic CRH secretion. On the other hand, the remaining eicosanoids tested induced a significant increase of hypothalamic CRH secretion (p less than 0.05). The concentration of 10(-11) M dexamethasone inhibited the effect of stimulatory eicosanoids on CRH secretion. The CRH response to U-49,619 was completely prevented by the TXA2 receptor antagonist SQ-29,548. The latter also inhibited serotonin (5-HT)-, acetylcholine (ACh)- and PGF2 alpha-induced CRH release. Indomethacin was capable of blocking the secretion of CRH induced by 5-HT and ACh. In addition, PGE2 inhibited the increase of CRH secretion induced by PGF2 alpha, 5-HT and ACh. These findings suggest that eicosanoids may be involved in the regulation of hypothalamic CRH secretion, either as autocrine/paracrine or as endocrine factors.

Acetylcholine

Further characterization of the in vitro and in vivo activity of ciprofloxacin against mycoplasmas.

The aim of this study was the evaluation of some parameters which might better characterize ciprofloxacin: the influence of inoculum, serum and medium. Resistance development, hamster protection and mycoplasmacidal concentrations were also investigated. Ciprofloxacin showed moderate antimycoplasmal activity, both in vitro and in vivo. The minimum inhibitory concentrations (MICs) for Ureaplasma urealyticum, if compared to those shown by erythromycin, are lower, but higher than those obtained with tetracyclines. Unlike the macrolides, ciprofloxacin suffers from change of inoculum size, but no single step resistance induction was reported both in ureaplasmas and mycoplasmas. If Mycoplasma pneumoniae pneumonia or genital infections due to U. urealyticum carry out gram-negative rod isolation, ciprofloxacin can be considered a valid therapeutic agent for these mixed infections.

Animals

The implant sulcus.

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Dental Implantation

A view from above.

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Dental Implantation