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R Llamas

Publications and source records attributed to R Llamas.

At least 19 recordsLinked to original sources
PubMed1997

In vitro study of the effect of sodium hypochlorite and glutaraldehyde on substrate adherence capacity of macrophages.

The purpose of this study was to investigate the in vitro effect of two irrigation solutions used in endodontics (5.25% sodium hypochlorite and 1% glutaraldehyde) on substrate adherence capacity of macrophages to determine if these substances can alter macrophage function. Inflammatory macrophages were obtained from Wistar rats and resuspended in RPMI-1640 medium. Substrate adherence capacity assays were carried out in Eppendorf tubes for 15 min of incubation at 37 degrees C in a humidified atmosphere of 5% CO2. The adherence index was calculated. Results showed that both sodium hypochlorite and glutaraldehyde significantly decreased the substrate adherence capacity of inflammatory macrophages. To take into account that adhesion is the first step in the phagocytic process of macrophages and in antigen presentation, sodium hypochlorite and glutaraldehyde could inhibit macrophage function and reduce inflammatory reactions in periapical tissues when they are used in root-canal therapy.

Animals↗
PubMed1997

EDTA inhibits in vitro substrate adherence capacity of macrophages: endodontic implications.

The disodium salt of ethylenediamine tetraacetate (EDTA) is a calcium ion chelator used in endodontics to enlarge root canals. This study investigated the effect of EDTA on substrate adherence capacity of rat inflammatory macrophages to determine if EDTA leakage to periapical tissues during root canal therapy can alter macrophage function. Inflammatory macrophages were obtained from Wistar rats and resuspended in RPMI-1640 medium. Substrate adherence capacity assays were carried out in Eppendorf tubes for 15 min of incubation at 37 degrees C in a humidified atmosphere of 5% CO2. The adherence index (AI) was calculated. Results showed that EDTA decreased substrate adherence capacity of inflammatory macrophages in a time and dose-dependent manner. The lowest EDTA concentration that caused a significant inhibition of AI was 50 mM (p < 0.05), and the EDTA concentration that caused half-maximal inhibition (IC50) was 194 +/- 20 mM (p < 0.01). Calcium chloride (10 mM) increased the adherence index of macrophages by 17.1% (p < 0.05) and decreased the EDTA inhibitory effect on AI by 49.5% (p < 0.05). We conclude that an EDTA concentration lower than that used in endodontics decreased the substrate adherence capacity of macrophages significantly. Adhesion is the first step in the phagocytic process and in antigen presentation, but leakage of EDTA to periapical tissues during root canals preparation may inhibit macrophage function and reduce periapical inflammatory reactions.

Animals↗
PubMed1997

Calcium hydroxide inhibits substrate adherence capacity of macrophages.

The purpose of this study was to investigate the effect of calcium hydroxide on substrate adherence capacity of rat inflammatory macrophages to determine if calcium hydroxide can alter macrophage function. Inflammatory macrophages were obtained from Wistar rats and resuspended in RPMI-1640 medium. Substrate adherence capacity assays were carried out in Eppendorf tubes for 15 min of incubation at 37 degrees C in a humidified atmosphere of 5% CO2. The adherence index (AI) was calculated. Results showed that calcium hydroxide decreased substrate adherence capacity of inflammatory macrophages in a time and dose-dependent manner. The lowest calcium hydroxide concentration that caused a significant inhibition of AI was 1 mM (p < 0.05), and the concentration of calcium hydroxide that caused half-maximal inhibition (IC50) was 1.54 mM (p < 0.01). We conclude that calcium hydroxide decreased substrate adherence capacity of macrophages. When adhesion as the first step in the phagocytic process and in antigen presentation is taken into account, calcium hydroxide could inhibit macrophage function and reduce inflammatory reactions in periapical tissues or in dental pulp when it is used in root-canals therapy or in direct pulp capping and pulpotomy, respectively. Moreover, this effect could explain, at least in part, the mineralized tissue-inducing property of calcium hydroxide.

Animals↗
PubMed1997

In vitro effect of parachlorophenol and camphorated parachlorophenol on macrophages.

The purpose of this study was to investigate the "in vitro" effect of parachlorophenol and camphorated parachlorophenol, used in endodontics for the disinfection of root canals, on the substrate adherence capacity of macrophages. Inflammatory macrophages were obtained from Wistar rats and resuspended in RPMI-1640 medium. As a test of macrophage phagocytic function, the adherence capacity of macrophages to a plastic surface was determined. Assays were conducted in Eppendorf tubes for 15 min of incubation at 37 degrees C in a humidified atmosphere of 5% CO2. The adherence index was calculated. Results showed that parachlorophenol and camphorated parachlorophenol significantly decreased the substrate adherence capacity of inflammatory macrophages. Taking into account that adhesion is the first step in the phagocytic process of macrophages and in antigen presentation, parachlorophenol and camphorated parachlorophenol could inhibit macrophage function and modulate immune and inflammatory reactions in periapical tissues.

Animals↗
PubMed1997

Cutaneous lesions in patients with visceral leishmaniasis and HIV infection.

Cutaneous lesions attributed to Leishmania are very seldom observed in classic Kala-Azar, but recently some reports have mentioned them in patients with HIV infection. We found cutaneous lesions whose biopsy disclosed the presence of Leishmania organisms in six patients of a group of 32 HIV patients with visceral Leishmaniasis. These lesions did not present a uniform or specific appearance, even though they tended to localize symmetrically on acral zones. They consisted of erythematous papules and hypopigmented macules on the dorsa of the hands, feet, and elbows; small subcutaneous nodules on the thighs; and erythematoviolaceous, scaly plaques on the face. These lesions accompanied in every case the other symptoms and/or signs of visceral leishmaniasis, responded to anti-leishmanial treatment, and were sometimes the first indicator of recurrence. The histopathological study was non-specific, but showed in every case the presence of abundant amastigotes within the dermal histiocytes and free in the dermis or subcutaneous tissue. Data from literature review are similar to ours.

Adult↗
PubMed1997

Multiple dens invaginatus affecting maxillary lateral incisors and a supernumerary tooth.

Dens invaginatus is a developmental variation resulting from an alteration in the normal growth pattern of the dental papilla of a tooth. This anomaly occurs predominantly in maxillary permanent lateral incisors. Multiple occurrence in maxillary incisor teeth in the same patient has frequently been reported, and examination of bilateral teeth for the anomaly is often carried out routinely. This paper reports an unusual case of multiple invaginations, including dens invaginatus affecting maxillary lateral incisors and a supernumerary tooth and minor invaginations of the upper canines. Moreover, the case illustrates the importance of examining all the teeth in patients who present with dens invaginatus and palatal pits in incisors and canines. The possibility that the supernumerary tooth had resulted from gemination of the lateral incisor tooth germ is discussed.

Dens in Dente↗
PubMed1997

CyberCHEST.

Explore the source record for details and available documents.

Computer Communication Networks↗
PubMed1996

The disodium salt of EDTA inhibits the binding of vasoactive intestinal peptide to macrophage membranes: endodontic implications.

The purpose of this study was to investigate the effect of the disodium salt of ethylenediamine tetraacetate (EDTA), a calcium ion chelator used in the root canal therapy, on vasoactive intestinal peptide (VIP) binding to macrophage membranes (MM's). Binding assays were conducted at 15 degrees C in 0.5 ml of 50 mM Tris-HCl buffer (pH 7.5) containing 1.6% (w/v) bovine serum albumin, 1.2 mg/ml of bacitracin, and different EDTA concentrations, using 45 pM of [125I]VIP as tracer. Results showed that EDTA inhibits VIP binding to MM's in a dose-dependent manner, with an IC50 value of 5.4 mM (p < 0.01). EDTA concentrations equal or higher than 100 mM of abolished VIP-MM interaction. Taking into account that the macrophage plays an essential role in inflammatory reactions and the immune response, we conclude that the apical extrusion of EDTA during root canal therapy could modify VIP-macrophage interaction modulating the inflammatory mechanisms involved in periapical lesions.

Animals↗
PubMed1993

Taurodontism in premolars.

Taurodontism is not a dental anomaly that affects only the molars. In a review of 379 premolars extracted for different pathologic reasons, three cases of taurodontism were found. The three cases were in upper premolars and were studied anatomically and radiographically. The literature was reviewed, as well as the low incidence of the condition in premolars, which is probably related to a genetic condition. Our observations support this fact, as suggested by the study of our cases from a restricted population nucleus, within a district area of the city of Seville, Spain. Among the diagnostic criteria of taurodontism, those established by Shifman and Chanannel are more objective. Finally, our findings support an embryologic origin as a result of a delay in the apical epithelial diaphragm evagination or by interference in the epitheliomesenchymatose induction.

Adolescent↗
PubMed1990

Disseminated strongyloidiasis in AIDS and non-AIDS immunocompromised hosts: diagnosis by sputum and bronchoalveolar lavage.

In conclusion, disseminated strongyloidiasis is a fatal disease that commonly affects the lungs. The disease should be suspected in an immunocompromised host who came from an area endemic for S stercoralis even years before the onset of symptoms or in patients with unexplained gram-negative bacteremia or meningitis. Treatment should be started promptly and should be maintained for a long time.

Acquired Immunodeficiency Syndrome↗