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C Merlini

Publications and source records attributed to C Merlini.

18 recordsLinked to original sources
PubMed1992

A mathematical model for the computation of the forces exerted by the facial orthopedic mask.

This study presents a model for the computation of the forces exerted on the chin and on the forehead by the facial orthopedic mask in skeletal Class III malocclusions. Cephalometric data as well as geometry of the mask are taken into account to simulate in quantitative terms the entire approach. A computer program has been implemented to validate the model on a group of patients. Despite the approximations about the mechanical characteristics of the appliance and of the constraints (rigid body, ideal constraints) and despite the unavoidable errors in the estimation of the geometric parameters (dimensions and angles), it is shown that the computation of the forces (in orientation and in magnitude) at the forehead and at the chin is possible. Some practical applications of the model are presented.

Adolescent↗
PubMed1992

Immunological and clinical effect of long-term oral treatment with RU 41740 in patients with chronic bronchitis: double-blind trial long-term versus standard dose regimen.

The immunological and clinical effects of two oral treatment schedules of RU 41740 (standard for 3 months vs. long-term for 6 months) were assessed in 40 patients with chronic bronchitis by a controlled, double-blind, randomized trial. Both treatments significantly improved phagocytosis index of both neutrophils and monocytes, and the phagocytosis frequency and the candidacidal activity of neutrophils, showing the maximum stimulation at the end of the third course of treatment. Both treatment schedules reduced the number and the duration of infectious exacerbations of chronic bronchitis with respect to those observed in the corresponding period of the previous year. However, no significant difference between standard and long-term treatment with RU 41740 was found with respect to the immunological and clinical effect and tolerability.

Administration, Oral↗
PubMed1992

Uptake of flurithromycin by human polymorphonuclear phagocytes: partial characterization of the entry mechanism.

The ability of flurithromycin and erythromycin to enter human polymorphonuclear phagocytes were studied and compared by a velocity centrifugation gradient technique. Both macrolides were markedly concentrated by human cells and attained cellular to extracellular concentration ratios (C/E) > or = 10. The incorporation was rapid and essentially complete after 60 min incubation. When PMNs were pretreated with formaldehyde, or incubated at low temperatures (4-25 degrees C) or at low pH, the transport ratios of both molecules were reduced. Sodium fluoride and 2,4-dinitrophenol, which decreased erythromycin uptake, did not affect flurithromycin penetration. Perturbation of cell membrane by phorbol myristate acetate, but not by formyl methionyl leucyl peptide, affected C/E ratios of both antibiotics. The addition of amino acids or nucleosides did not influence their transfer into PMNs.

Adult↗
PubMed1992

Evidence for CD8+ cell increase in long-term PUVA-treated psoriatic patients after PUVA discontinuation.

Long-term PUVA-treated psoriatic patients given maintenance therapy (UVA doses greater than 1,000 J/cm2) have been demonstrated to undergo lymphopenia and a decrease in the total number of circulating CD3+ and CD4+ T cells. The aim of this study was to assess whether the impairment of T cells is detectable also in psoriatic patients after long-lasting PUVA discontinuation. A group of 34 psoriatic patients (25 males, 9 females; mean age 52.7 +/- 12.82 years), who had previously been treated by PUVA therapy (average cumulative dose 1,898.48 +/- 1,207.12 J/cm2), was studied 1 year or more after discontinuation of PUVA therapy. The patients studied failed to show any impairment in CD3+ and CD4+ cells. Nevertheless, a significant increase (p less than 0.05) in circulating CD8+ cells (both in the percentage and the total number) was detectable in PUVA patients as compared to appropriate controls. The significance and implications of this finding are not known and need further investigations.

CD4-CD8 Ratio↗
PubMed1991

[Apical resorption in pre-surgical orthodontics].

Apical root resorption is a frequent phenomenon observed in pre-surgical orthodontic; the reason is double: we deal with adult patients and we often move the teeth in the opposite direction compared to the position obtained in previous inefficacious orthodontic treatments. Notwithstanding the amount of apical root resorption we couldn't record an hyper-mobility of the teeth and a long term evaluation of occlusal stability didn't show any significant change.

Adult↗
PubMed1991

[Odontogenic and nonodontogenic epithelial rests. Embryological origin].

The close examination of the central osseous and/or parosteal lesions of the jaws must be reconducted to the study of the main fundamental embryonal processes that take place in the primordial stomodeus. Some pathological lesions can arise from the rests that survive after the disgregation of various odontogenic epithelial structures destined to disappear with growth: the epithelial root sheath, the dental lamina and the external epithelium of the enamel organ. Some osseous lesions can also originate from the nonodontogenic epithelial rests: this tissue comes from the uncompleted obliteration of the ectodermic layer during the processes of union and fusion of the various embryonal components of the maxillary structures.

Amelogenesis↗
PubMed1991

[Intraosseous developmental cysts of the jaw. 1].

Discussing the central intraosseous developmental odontogenic cysts of the jaws the Authors have followed the classification suggested by Hoffman et Al. that lists the lesions according to their biological activity. After a short foreword about the most important stages of the embryological dental development, grouped in six phases, the Authors referred to the principal concepts emerging from the literature about the most aggressive developmental odontogenic cysts of the jaws: the primordial cyst and the odontogenic keratocyst of which they have outlined a definition, and referred to the clinical, radiological, ethiological and microscopical data, the treatment and the differential diagnosis.

Adult↗
PubMed1991

[Intraosseous developmental cysts of the jaw. 2].

The Authors conclude the chapter about the central intraosseous developmental odontogenic cysts. Some of them are very rare, others are very similar histogenetically with other more frequent cystic lesions of the jaws. Notwithstanding the radiographic and macroscopic aspect apparently similar, these lesions are very different between each other in their biological activity. The classification, suggested by Hoffman, Jacoway and Krolls lists these lesions from the least to the most aggressive. We have here considered the multiple nevoid basal cell carcinoma syndrome, also known as Gorlin-Goltz syndrome, associated to one or more keratinized maxillary cysts, the calcifying odontogenic cyst, the more frequent and well known dentigerous cyst, the lateral periodontal cyst with its uncertain etiology and the harmless eruption cyst.

Basal Cell Nevus Syndrome↗
PubMed1991

[Inflammatory odontogenic lesions of the jaws].

The apical granuloma, the periapical abcess and the radicular cyst are the most frequent between the inflammatory odontogenic lesions of the jaws. These three lesions are caused by the necrosis of the pulp but are very different between each other from an histological point of view and they can correspond to different stages of the same pathological process considering the fact that from a granuloma can arise a periapical abcess or a radicular cyst and from a radicular cyst and abcess can originate. About these three pathological processes we discuss in this article the clinical, radiographical, ethiological, microscopical features, we suggest the treatment and the differential diagnosis.

Bone Resorption↗
PubMed1991

[Apical scars. A healing abnormality].

The Authors presented the clinical report of an apical scar because of the rareness of the case and because of the interesting differential diagnosis: this lesion has a cystic radiological aspect and must be differentiated from the real odontogenic cysts of the jaws; the apical scar does not belong to the cystic pathology and represents just a defect of the healing process: no treatment is requested as the apical scar mustn't be considered a pathology.

Cicatrix↗