Establishment and characterization of a telomerase immortalized human gingival epithelial cell line.

BACKGROUND AND OBJECTIVE: Gingival keratinocytes are used in model systems to investigate the interaction between periodontal bacteria and the epithelium in the initial stages of the periodontal disease process. Primary gingival epithelial cells (GECs) have a finite lifespan in culture before they enter senescence and cease to replicate, while epithelial cells immortalized with viral proteins can exhibit chromosomal rearrangements. The aim of this study was to generate a telomerase immortalized human gingival epithelial cell line and compare its in vitro behaviour to that of human GECs. MATERIAL AND METHODS: Human primary GECs were immortalized with a bmi1/hTERT combination to prevent cell cycle triggers of senescence and telomere shortening. The resultant cell-line, telomerase immortalized gingival keratinocytes (TIGKs), were compared to GECs for cell morphology, karyotype, growth and cytokeratin expression, and further characterized for replicative lifespan, expression of toll-like receptors and invasion by P. gingivalis. RESULTS: TIGKs showed morphologies, karyotype, proliferation rates and expression of characteristic cytokeratin proteins comparable to GECs. TIGKs underwent 36 passages without signs of senescence and expressed transcripts for toll-like receptors 1-6, 8 and 9. A subpopulation of cells underwent stratification after extended time in culture. The cytokeratin profiles of TIGK monolayers were consistent with basal cells. When allowed to stratify, cytokeratin profiles of TIGKs were consistent with suprabasal cells of the junctional epithelium. Further, TIGKs were comparable to GECs in previously reported levels and kinetics of invasion by wild-type P. gingivalis and an invasion defective ΔserB mutant. CONCLUSION: Results confirm bmi1/hTERT immortalization of primary GECs generated a robust cell line with similar characteristics to the parental cell type. TIGKs represent a valuable model system for the study of oral bacteria interactions with host gingival cells.

Differential interactions of Streptococcus gordonii and Staphylococcus aureus with cultured osteoblasts.

The impedance of normal osteoblast function by microorganisms is at least in part responsible for the failure of dental or orthopedic implants. Staphylococcus aureus is a major pathogen of bone, and exhibits high levels of adhesion and invasion of osteoblasts. In this article we show that the commensal oral bacterium Streptococcus gordonii also adheres to and is internalized by osteoblasts. Entry of S. gordonii cells had typical features of phagocytosis, similar to S. aureus, with membrane protrusions characterizing initial uptake, and closure of the osteoblast membrane leading to engulfment. The sensitivities of S. gordonii internalization to inhibitors cytochalasin D, colchicine and monensin indicated uptake through endocytosis, with requirement for actin accumulation. Internalization levels of S. gordonii were enhanced by expression of S. aureus fibronectin-binding protein A (FnBPA) on the S. gordonii cell surface. Lysosomal-associated membrane protein-1 phagosomal membrane marker accumulated with intracellular S. aureus and S. gordonii FnBPA, indicating trafficking of bacteria into the late endosomal/lysosomal compartment. Streptococcus gordonii cells did not survive intracellularly for more than 12 h, unless expressing FnBPA, whereas S. aureus showed extended survival times (>48 h). Both S. aureus and S. gordonii DL-1 elicited a rapid interleukin-8 response by osteoblasts, whereas S. gordonii FnBPA was slower. Only S. aureus elicited an interleukin-6 response. Hence, S. gordonii invades osteoblasts by a mechanism similar to that exhibited by S. aureus, and elicits a proinflammatory response that may promote bone resorption.

[Total enteral nutrition vs. total parenteral nutrition in patients with severe acute pancreatitis]. / Nutrición enteral total vs. nutrición parenteral total en pacientes con pancreatitis aguda grave.

OBJECTIVE: To compare the efficacy of early total enteral nutrition (TEN) vs. total parenteral nutrition (TPN) in patients with severe acute pancreatitis (SAP). METHODS: A total of 22 consecutive patients with SAP were randomized to receive TPN (group I) or TEN (group II). SAP was defined applying APACHE II score, C-reactive protein (CRP) measurements and/or Balthazar CT scan score. Acute inflammatory response (CRP, TNF-a, IL-6), visceral proteins (pre-albumin, albumin), complications (systemic inflammatory response syndrome, multiorgan failure, infections), surgical interventions, length of hospital stay and mortality were evaluated. RESULTS: No significant differences were found between the two groups in the APACHE II score, in CRP, TNF-a and IL-6 concentrations or in pre-albumin and albumin levels over the first 10 days. Seven patients in group I and 4 in group II suffered severe complications. Three patients in group I required surgical intervention. Length of hospital stay was alike in the two groups. Two patients from group I died in the course of the hospitalization. CONCLUSIONS: SAP patients with TEN feeding showed a tendency towards a better outcome than patients receiving TPN.

Nutrición enteral total vs. nutrición parenteral total en pacientes con pancreatitis aguda grave / Total enteral nutrition vs. total parenteral nutrition in patients with severe acute pancreatitis

Objetivo: comparar la eficacia de la instauración precoz de nutrición enteral total (NET) frente a nutrición parenteral total (NPT) en pacientes con pancreatitis aguda grave (PAG). Métodos: estudio prospectivo aleatorio. Se incluyeron consecutivamente 22 pacientes con PAG aplicando los criterios APACHE II, valores de PCR y graduación de Balthazar en la TC. El grupo I (n = 11) recibió NPT y el grupo II (n = 12) NET. Se valoró la respuesta inflamatoria (PCR, TNF-alfa, IL-6), las proteínas viscerales (pre-albúmina, albúmina), la tasa de complicaciones (síndrome de respuesta inflamatoria sistémica, fallo multiorgánico, infecciones), las intervenciones quirúrgicas, la estancia hospitalaria y la mortalidad. Resultados: no hubo diferencias significativas en los primeros 10 días entre los dos grupos en la evolución de los criterios APACHE II, en las concentraciones de PCR, TNF-alfa e IL-6 ni tampoco en los valores de pre-albúmina y albúmina. Siete pacientes del grupo I presentaron complicaciones graves frente a 4 del grupo II. Requirieron intervención quirúrgica 3 pacientes del grupo I. La estancia hospitalaria fue similar en los dos grupos. Dos pacientes del grupo I fallecieron. Conclusiones: se ha observado una tendencia a una mejor evolución de los pacientes con PAG que utilizaron NET frente a los que utilizaron NPT

Objective: to compare the efficacy of early total enteral nutrition (TEN) vs. total parenteral nutrition (TPN) in patients with severe acute pancreatitis (SAP). Methods: a total of 22 consecutive patients with SAP were randomized to receive TPN (group I) or TEN (group II). SAP was defined applying APACHE II score, C-reactive protein (CRP) measurements and/or Balthazar CT scan score. Acute inflammatory response (CRP, TNF-alpha, IL-6), visceral proteins (pre-albumin, albumin), complications (systemic inflammatory response syndrome, multiorgan failure, infections), surgical interventions, length of hospital stay and mortality were evaluated. Results: no significant differences were found between the two groups in the APACHE II score, in CRP, TNF-alpha and IL-6 concentrations or in pre-albumin and albumin levels over the first 10 days. Seven patients in group I and 4 in group II suffered severe complications. Three patients in group I required surgical intervention. Length of hospital stay was alike in the two groups. Two patients from group I died in the course of the hospitalization. Conclusions: SAP patients with TEN feeding showed a tendency towards a better outcome than patients receiving TPN