Bacteria associated with periodontal disease are also increased in health.

BACKGROUND: The objective of this cross-sectional clinical study was to analyze the differences in the microbiome in gingival sulci of adult patients in the presence or absence of chronic periodontitis. MATERIAL AND METHODS: Patients with or without periodontal disease were included in this cross-sectional study. Subgingival biofilm samples were collected and analyzed by 16S massive pyrosequencing. Functional analyses were also performed. RESULTS: A total of 15 phyla, 154 genera and 351 species were detected globally. Differences between disease and non-disease samples were observed in all taxonomical levels which suggest functional profile changes in the community. It was found that the main species associated with non-disease samples were reduced in disease but not completely suppressed. Analysis of the functional potential of the biofilms revealed a significantly higher activity related to endocytosis and phosphatidylinositol signaling in the disease group but lower cell adhesion molecules. CONCLUSIONS: Specific differences between health and disease suggest functional profile changes in the community, although bacteria associated with periodontal disease are also increased in health. Transcriptome studies should be conducted to confirm and deepen metabolic dysfunctions.

Simvastatin exerts antiproliferative and differentiating effects on MG63 osteoblast-like cells: Morphological and immunocytochemical study.

BACKGROUND AND OBJECTIVE: Current evidence suggests that statins exert an anabolic effect on bone and may therefore impact on osteogenic differentiation and proliferation. These effects can be useful for their use in guided bone regeneration. The objective of this study was to determine the in vitro effects of simvastatin on the differentiation and proliferation of MG63 human osteoblast tumor cells. MATERIAL AND METHODS: MG63 human osteosarcoma cells were cultured in the presence of simvastatin or solvent alone for 72 hours, and their proliferation was assessed by MTT assay. Cells from the culture were prepared for light, transmission and scanning electron microscopy studies. immunocytochemical was used to analyze the differentiation and proliferation markers Musashi-1, Ki-67, CD56 and CD44. RESULTS: Cultured MG63 control cells showed spheroid morphology with numerous secretion vesicles accumulated on the surface, observing no cytoplasmic projections with intercellular connections. However, cells cultured with simvastatin had a polygonal and spindle-shaped morphology, with cytoplasmic projections that interconnected cells. There were numerous microvilli-like filamentous projections on the surface with no defined pattern. At 72 hours of culture, CD56, Ki-67 and Musashi-1 expression was significantly reduced (P < .001) in simvastatin-treated cells. CD44 expression was intense in both groups and was not affected by simvastatin treatment. CONCLUSION: MG63 cells cultured with simvastatin for 72 hours undergo morphological and surface changes. Simvastatin treatment exerts antiproliferative and differentiating effects on these cells as well as promoting recovery of cellular homeostasis.

Oral bacteria in placental tissues: increased molecular detection in pregnant periodontitis patients.

OBJECTIVES: The objective of this study was to identify the DNA of oral bacteria in placental samples from women with and without periodontitis who had or had not had preterm births and/or low birthweight (PB/LBW) neonates. METHODS: Data were gathered from 57 puerperal women in relation to socio-demographic, gynaecological, and periodontal variables and to placental histomorphology. Fifty-seven biopsies, 28 from mothers with periodontitis, were taken aseptically from preterm placentas (n = 36) and from full-term placentas (n = 21). Total DNA was extracted, and the presence of 15 oral bacteria was assessed using Nested-PCR. RESULTS: The placentas from women with periodontitis showed a higher prevalence of periodontopathogens compared to those from women without periodontitis (P = 0.009). Samples showed low prevalences of Actinomyces israelii, Parvimonas micra and Tannerella forsythia. An association was found between Eikenella corrodens in placenta and periodontitis (P = 0.002). The most ubiquitous bacterium, Fusobacterium nucleatum, was more prevalent in mothers with periodontitis and PB/LBW (P = 0.033). Porphyromonas gingivalis, Treponema denticola, Prevotella intermedia and Aggregatibacter actinomycetemcomitans were not detected. CONCLUSIONS: These results, along with previous findings, show that oral bacteria may be normally present in the placenta, however, the levels of certain oral pathogens in the placenta would highly depend on the mother's periodontal state.

Acute myocardial infarct size is related to periodontitis extent and severity.

Cardiovascular disease has been associated with 40% of deaths in high-income countries and 28% in lower-income countries. The relationship between periodontitis and acute myocardial infarction is well documented, but it has not been established whether the extent and severity of periodontitis influence the infarct size. This cross-sectional and analytic study was designed to investigate the association of chronic periodontitis extent and severity with acute myocardial infarct size as indicated by serum cardiac troponin I and myoglobin levels. Sociodemographic, periodontal, cardiologic, and hematologic variables were gathered in 112 consecutive patients with myocardial infarction. The extent (Arbes Index) and severity (Periodontal Inflammatory Severity Index) of the chronic periodontitis were significantly associated with troponin I levels after controlling for sociodemographic and clinical confounders (change in R (2) = .041, p < .02, and R (2) = .031, p = .04). However, only the extent index accounted for levels of myoglobin (change in R (2) = .030, p < .05), total leukocytes (change in R (2) = .041 p < .02), and neutrophils (change in R (2) = .059, p < .01). Mediated regression analysis showed that leukocytes and neutrophils may underlie these observed relationships of chronic periodontitis with troponin I and myoglobin. To our knowledge, this study contributes the first research data demonstrating that the extent and severity of periodontitis is positively associated with acute myocardial infarct size as measured by serum troponin I and myoglobin levels.

Peripheral nerve reconstruction with epsilon-caprolactone conduits seeded with vasoactive intestinal peptide gene-transfected mesenchymal stem cells in a rat model.

OBJECTIVE: Attempts have been made to improve nerve conduits in peripheral nerve reconstruction. We investigated the potential therapeutic effect of a vasoactive intestinal peptide (VIP), a neuropeptide with neuroprotective, trophic and developmental regulatory actions, in peripheral nerve regeneration in a severe model of nerve injury that was repaired with nerve conduits. APPROACH: The sciatic nerve of each male Wistar rat was transected unilaterally at 10 mm and then repaired with Dl-lactic-ε-caprolactone conduits. The rats were treated locally with saline, with the VIP, with adipose-derived mesenchymal stem cells (ASCs) or with ASCs that were transduced with the VIP-expressing lentivirus. The rats with the transected nerve, with no repairs, were used as untreated controls. At 12 weeks post-surgery, we assessed their limb function by measuring the ankle stance angle and the percentage of their muscle mass reduction, and we evaluated the histopathology, immunohistochemistry and morphometry of the myelinated fibers. MAIN RESULTS: The rats that received a single injection of VIP-expressing ASCs showed a significant functional recovery in the ankle stance angle (p = 0.049) and a higher number of myelinated fibers in the middle and distal segments of the operated nerve versus the other groups (p = 0.046). SIGNIFICANCE: These results suggest that utilization of a cellular substrate, plus a VIP source, is a promising method for enhancing nerve regeneration using Dl-lactic-ε-caprolactone conduits and that this method represents a potential useful clinical approach to repairing peripheral nerve damage.

Low serum mannose-binding lectin levels are associated with inflammation and apoptosis in early surveillance allograft biopsies.

INTRODUCTION: Mannose-binding lectin (MBL) is a protein of the innate immune system that participates in host defense and the tissue injury/repair process, enhancing the clearance of apoptotic cells by macrophages. The aim is to characterize the relationship between pre-transplant MBL levels, histological lesions and number of apoptotic cells in early surveillance renal allograft biopsies. PATIENTS AND METHODS: Consecutive renal transplant recipients were recruited and MBL levels were classified into tertiles. The first tertile was considered the low MBL group. Surveillance biopsies were done during the first 6 months and were evaluated according to Banff criteria. Renal inflammatory infiltrates were studied by immunohistochemical techniques. Apoptosis was studied using morphological methods in renal tubular cells and was expressed as the number of apoptotic cells/mm(2). RESULTS: MBL was determined in 126 patients and a surveillance biopsy with sufficient tissue was obtained in 41 of them. Patients with low pre-transplant MBL levels showed a higher acute Banff index (3.14 ± 1.96 vs. 1.88 ± 1.56, p = 0.044) and an increased proportion of biopsies with tubular cell apoptosis The proportion of biopsies with tubular cell apoptosis was higher in patients with low pre-transplant MBL levels in comparison with patients with high MBL levels (4.3 ± 3.6 versus 0.2 ± 0.9 p = 0.012) and increased interstitial number of inflammatory cells and significantly the macrophages/mm(2) (109 ± 118 vs. 32 ± 46; p = 0.04). CONCLUSION: Low pre-transplant serum MBL levels are associated with more severe inflammation and increased apoptosis in early surveillance renal allograft biopsies suggesting that MBL modulates renal inflammation after transplantation.

Human umbilical cord stromal stem cell express CD10 and exert contractile properties.

BACKGROUND: It has been demonstrated that human umbilical cord stromal stem cells (UCSSCs) are bio-equivalent to bone marrow mesenchymal stem cells. However, little is known about their tissue origin or in vivo functions, and data on their expansion properties are limited due to early senescence in the culture methods described to date. METHODS: UC sections and cultured UCSSCs were analyzed with a panel of 12 antibodies. UCSSCs were grown in low-FCS containing medium at 5% or 21% oxygen and were assayed for their clonogenic properties, karyotype stability, expression of specific cellular markers, and multi-lineage potential. UCSSC contractile properties were evaluated by using collagen gel contraction assays under cytokine stimulus. RESULTS: Immunohistochemistry studies showed that the UCSSCs were derived from the Wharton's jelly and not from the vascular smooth muscle sheath of the blood vessels. UCSSC growth properties were increased in a 5% oxygen atmosphere in comparison to normoxic culture conditions. In both culture conditions, UCSSCs were CD14-, CD34-, and CD45-negative while expressing high levels of CD73, CD90 and CD105 and maintaining their differentiation potentialities. UCSSCs expressed alpha smooth muscle actin and behaved as functional myofibroblasts when cellular contraction was challenged with appropriate stimuli. CONCLUSIONS: UCSCs are mesenchymal stem cells that reside in the perivascular area of Wharton's jelly and are phenotypically and functionally related to myofibroblasts.

Human adipose-derived mesenchymal stem cells reduce inflammatory and T cell responses and induce regulatory T cells in vitro in rheumatoid arthritis.

OBJECTIVES: Adult mesenchymal stem cells were recently found to suppress effector T cell and inflammatory responses and have emerged as attractive therapeutic candidates for immune disorders. In rheumatoid arthritis (RA), a loss in the immunological self-tolerance causes the activation of autoreactive T cells against joint components and subsequent chronic inflammation. The aim of this study is to characterise the immunosuppressive activity of human adipose-derived mesenchymal stem cells (hASCs) on collagen-reactive T cells from patients with RA. METHODS: The effects of hASCs on collagen-reactive RA human T cell proliferation and cytokine production were investigated, as well as effects on the production of inflammatory mediators by monocytes and fibroblast-like synoviocytes from patients with RA. RESULTS: hASCs suppressed the antigen-specific response of T cells from patients with RA. hASCs inhibited the proliferative response and the production of inflammatory cytokines by collagen-activated CD4 and CD8 T cells. In contrast, the numbers of IL10-producing T cells and monocytes were significantly augmented upon hASC treatment. The suppressive activity of hASCs was cell-to-cell contact dependent and independent. hASCs also stimulated the generation of FoxP3 protein-expressing CD4(+)CD25(+) regulatory T cells, with the capacity to suppress collagen-specific T cell responses. Finally, hASCs downregulated the inflammatory response and the production of matrix-degrading enzymes by synovial cells isolated from patients with RA. CONCLUSIONS: The present work identifies hASCs as key regulators of immune tolerance, with the capacity to suppress T cell and inflammatory responses and to induce the generation/activation of antigen-specific regulatory T cells.

Effect of preconditioning with triiodothyronine on renal ischemia/reperfusion injury and poly(ADP-ribose) polymerase expression in rats.

The ischemia/reperfusion (I/R) model in rats allows pharmacological investigation of protective renal effects of certain agents to thereby diminish the incidence of delayed graft function (DGF). The aim of this study was to determine the effects of preconditioning with triiodothyronine (T(3)) on renal function and oxidative status in renal I/R injury. Forty male Wistar rats were preconditioned with T(3) (100 microg/kg) or control (normal saline) at 24 hours prior to 45 minutes of renal ischemia, followed by a 4-hour (groups C-4h and T(3)-4h) or 24-hour (groups C-24h and T(3)-24h) reperfusion period. We determined renal function parameters (urea, creatinine, and proteinuria), oxidative stress biomarkers in plasma (malondialdehyde [MDA], glutathione [GSH], and superoxide dismutase [SOD]), urine (hydrogen peroxide [H(2)O(2)]), and renal tissue (GSH and MDA), and poly(ADP-ribose) polymerase (PARP-1) expression. Proteinuria was significantly lower in the T(3)-treated group (4.63 +/- 1.9 vs 9.27 +/- 0.72 mg/mL/100 g body weight). Pretreated rats showed lower levels of plasma and tissue MDA and urine H(2)O(2) (50.57 +/- 1.17 vs 71.16 +/- 1.14 micromol/100 g body weight). The T(3) treatment was associated with lower postischemia GSH concentrations (3.82 +/- 1.16 vs 4.89 +/- 0.68 nmol/mg protein) and higher SOD levels at 24 hours (11.27 +/- 0.86 vs 9.92 +/- 1.77 nmol/mg protein). Preconditioning with the hormone also reduced PARP-1 tissue expression by 18% (P

[Methotrexate-associated lymphoproliferative disorder presenting as oral ulcers in a patient with rheumatoid arthritis]. / Ulceras orales como manifestación clínica de proceso linfoproliferativo asociado a metotrexato en una paciente con artritis reumatoide.

Methotrexate-associated lymphoproliferative disorders are a heterogeneous group of lymphoid proliferations or lymphomas that develop in patients with autoimmune diseases treated using methotrexate. These lymphoproliferative disorders are often associated with Epstein-Barr virus infection and occasionally regress after the withdrawal of methotrexate therapy. The lymphoproliferative disorder in this case was diffuse large B-cell lymphoma, unusually presenting as oral ulcers in a 79-year-old woman on treatment with methotrexate for longstanding rheumatoid arthritis. Latent membrane protein 1 positivity was detected by immunohistochemistry and Epstein-Barr-virus encoded small RNA positivity by chromogenic in situ hybridization. Clonality was confirmed by immunohistochemistry (kappa light-chain restriction), polymerase chain reaction (monoclonal immunoglobulin H gene rearrangement), and capillary electrophoresis (GeneScan). Staging procedures were negative. Withdrawal of methotrexate therapy led to complete remission within 6 weeks, and the patient is alive and disease-free 18 months after the diagnosis was made. The oral cavity is not often involved in the initial presentation of methotrexate-associated lymphoproliferative disorders, and presentation with intraoral ulcers is very rare. We have performed a review of the literature on methotrexate-associated lymphoproliferative disorders presenting as ulcers in the oral cavity.

Immunephenotype of glomerular and interstitial infiltrating cells in protocol renal allograft biopsies and histological diagnosis.

Patients with a protocol renal allograft biopsy simultaneously displaying interstitial fibrosis/tubular atrophy (IF/TA) and subclinical rejection (SCR) have a shortened graft survival than patients with a normal biopsy, or with a biopsy only displaying IF/TA or SCR. The poor outcome of these patients could be related with a more severe inflammation. We evaluate the immunophenotype of infiltrating cells in these diagnostic categories. Nonexhausted paraffin blocks from protocol biopsies done during the first year were stained with anti-CD45, CD3, CD20, CD68 and CD15 monoclonal antibodies. Glomerular and interstitial positive cells were counted. C4d deposition in peritubular capillaries was evaluated. Histological diagnoses were: normal (n = 80), SCR (n = 17), IF/TA (n = 42) and IF/TA + SCR (n = 17). Only interstitial CD20 positive cells were significantly increased in patients displaying IF/TA + SCR; normal (137 +/- 117), SCR (202 +/- 145), IF/TA (208 +/- 151) and IF/TA + SCR (307 +/- 180 cells/mm(2)), p < 0.01. The proportion of biopsies displaying C4d deposition was not different among groups. The upper tertile of CD20 positive interstitial cells was associated with a decreased death-censored graft survival (relative risk: 3.01, 95% confidence interval: 1.23-7.35; p = 0.015). These data suggest that B-cell interstitial infiltrates are associated with histological damage and outcome, but do not distinguish whether these infiltrates were the cause or the consequence of chronic tubulo-interstitial damage.

Poly(ADP-ribose) polymerase expression in kidney transplantation: from alfa (alpha) to Omega (Omega).

INTRODUCTION: Overactivation of the enzyme poly(ADP-ribose) polymerase (PARP-1) can be induced by ischemia-reperfusion and involved in the renal injury subsequent to kidney transplant. The poly(ADP-ribosy)lation mechanism alters free radical-induced DNA damage, which is repair by PARP-1 polymer. However, PARP-1 overexpression induces cellular necrosis. Our aim was to study the immunohistochemical PARP-1 expression in kidney transplant biopsies associated with various events. MATERIALS AND METHODS: We studied the nuclear expression of PARP-1 in kidney tubule cells by immunohistochemistry using the monoclonal antibody PAR01 in donor biopsies without acute tubular necrosis (ATN) (n = 60; controls), allografts that suffer ATN (n = 90) or an episode of acute humoral rejection (n = 12) or acute tubulointerstitial rejection (n = 25), or chronic allograft nephropathy (n = 25). Furthermore, we also studied protocol biopsies with subclinical rejection (n = 60). Renal lesions in transplant biopsies were graded blindly using 1997 Banff criteria without any clinical information. RESULTS: Biopsies without morphological features of ATN, namely acute tubulointerstitial rejection, borderline or subclinical rejection, showed lesser PARP-1 expression compared with biopsies with ATN or with ischemic mechanism of acute humoral rejection or chronic allograft nephropathys. We observed an inverse relation between PARP-1 expression and renal function (P < .001). Overall, renal biopsies showing ATN revealed greater expression of PARP-1 (r = 0.785, Pearson test). A significant relationship with PARP-1 expression was demonstrated with renal function (effective diuresis, serum creatinine levels) and pretransplant cold ischemia time (P < .001). CONCLUSION: Kidney transplant events including ischemia were associated with the highest PARP-1 expression and worse allograft renal function.

Periodontal and oral microbiological status of an adult population undergoing haemodialysis: a cross-sectional study.

OBJECTIVES: The aim of this cross-sectional study was to evaluate the periodontal status and oral microbiological patterns of a population with end-stage renal disease (ESRD), undergoing haemodialysis (HD). DESIGN: This was a cross-sectional study, involving 52 patients from the Nephrology Department and 52 matched control subjects. MATERIALS AND METHODS: The subjects had a periodontal clinical examination; subgingival plaque samples were taken and analysed using a semiquantitative polymerase chain reaction (PCR) test to detect Porphyromas gingivalis, Tannerella forsythia, Prevotella intermedia, Prevotella nigrescens and Actinobacillus actinomycetemcomitans. Subgingival plaque and saliva samples were studied for Candida and Enterobacteriaceae. MAIN OUTCOME MEASURES: Most of the 104 subjects had some degree of loss of periodontal attachment (LPA) > or =3 mm [11 (10.5%) had severe LPA; 16 (15.4%) moderate LPA; and 64 (61.5%) mild LPA]. Only 13 subjects (12.5%) presented good periodontal health. RESULTS: No statistically significant differences were found between the HD patients and the control group regarding bleeding index, number of teeth, or percentage of LPA > or =3 mm. However, a statistically significant difference was seen in the degree of oral hygiene. CONCLUSIONS: On the basis of the findings presented here, we cannot associate ESRD with more severe periodontal destruction. Although HD patients presented a higher number of periodontopathic microorganisms than the matched controls, a prolonged duration of HD did not bear a statistically significant relationship with the percentage of sites with LPA > or =3 mm, specific microbiota or composition of biofilm.

Role of poly-(ADP-ribose) polymerase in transplant acute tubular necrosis and its relationship with delayed renal function.

The enzyme poly(ADP-ribose) polymerase (PARP-1) participates in the repair of DNA damaged by genotoxic agents such as oxygen-derived free radicals. If the allograft suffers pretransplant cold ischemia and subsequent ischemia-reperfusion injury (IR), overactivation of PARP-1 can be induced, which may lead to an increase in acute tubular necrosis (ATN) and a delay in total recovery of renal function (RRF) of the transplanted organ. We studied the nuclear expression of PARP-1 in tubular cells by immunohistochemistry with the monoclonal antibody PAR01 in 104 kidney transplant biopsies from allografts with ATN. In 50% of biopsies with ATN, >50% of tubular nuclei were PARP-1+; only 9.6% of biopsies were negative. The increase in the immunohistochemical expression of PARP-1 showed a statistically significant relationship with the duration of cold ischemia, with serum creatinine levels, and with the time required to achieve effective diuresis (P < .0001, Spearman test). Cold ischemia of >24 hours and serum creatinine levels >1.7 mg/dL showed a statistically significant relationship with the highest PARP-1 expression levels (2.83 +/- 0.4 vs 1.36 +/- 0.8, P < .0001, Mann-Whitney U test). We conclude that PARP-1 plays an important role in ATN and RRF and is related to the extent and severity of ATN and to the renal allograft function.

Role of poly (ADP-ribose) polymerase in kidney transplant and its relationship with delayed renal function: multivariate analysis.

UNLABELLED: Kidney allografts undergo pretransplant cold ischemia and consequent ischemia-reperfusion injury (IR). Poly (ADP-Ribose) polymerase (PARP-1) overactivation leads to massive NAD+ consumption and ATP depletion with induction of cellular necrosis under ischemic conditions, which may lead to an increase in acute tubular necrosis (ATN) and a delay in total recovery of renal function (RFR) of the transplanted organ. MATERIALS AND METHODS: Nuclear PARP-1 immunohistochemical expression (clone: PARP01) was studied in 155 paraffin-embedded renal biopsies from suboptimal donors and 95 kidney allograft biopsies with histopathological diagnosis of ATN. RESULTS: In 50% of ATN biopsies, more than 50% of tubular nuclei were immunostained for PARP-1. PARP-1 expression was higher in ATN biopsies than in those from suboptimal donors (2.40 +/- 0.74 vs 0.92 +/- 1.13, P = 0.0001 Mann-Whitney). PARP-1 showed a statistically significant relationship with the time required to achieve effective diuresis (Rho:0.779), with serum creatinine, and with duration of cold ischemia (Rho:0.803). These relationships were stronger in the biopsies with ATN. In conclusion, multivariate analysis demonstrated that PARP-1 expression and cold ischemia duration in kidney biopsies with ATN predicted the short-term delay in total recovery of renal function and serum creatinine in the first month.

Correlation of morphological findings with functional reserve in the aging donor: role of the poly (ADP-ribose) polymerase.

INTRODUCTION: The enzyme poly (ADP-ribose) polymerase (PARP-1) participates in the first events of DNA repair in higher organisms. Under conditions of tissue ischemia, this action can lead to significant decreases in NAD(+), massive adenosine triphosphate (ATP) depletion, and cell death. In renal grafts with pretransplantation cold ischemia and subsequent ischemia-reperfusion injury, overactivation of PARP-1 may lead to a higher index of acute tubular necrosis, a delay in total recovery of the function of the transplanted organ, and an early progression to chronic graft nephropathy. The present study examined whether increased tubular expression of PARP-1 in kidneys from aged donors contributed to recipient renal function. MATERIAL AND METHOD: We studied the nuclear expression of PARP-1 using immunohistochemistry with monoclonal antibody PAR01 in 75 kidney biopsy specimens from 40 aged donors. RESULTS: Immunohistochemical expression of PARP-1 showed a statistically significant relationship with donor age (r =.408, P =.006, Spearman test), with time required to achieve effective diuresis (r =.386, P =.01, Spearman test) and with creatinine levels in the first 3 months. We also highlighted a greater intensity of PARP-1 expression in suboptimal donor kidneys that failed to reduce the serum creatinine levels to <1.7 mg/dL (creatinine <1.7 PARP: 1.29 +/- 1.49 vs creatinine >1.7 PARP: 2.29 +/- 1.33, P =.047, Mann-Whitney U test). CONCLUSION: We conclude that the determination of PARP-1 in biopsy specimens from aged donors may be a useful predictive factor for renal graft function.

Vigabatrin-induced modification of Ki-67 expression in gingival epithelium: immunohistochemical study of a short series.

OBJECTIVE: To study the expression and role in vigabatrin (VGB)-induced gingival enlargement of Ki-67 antigen and p27KIP1, p21WAF1, and p53, proteins that activate or inhibit cell-cycle progression. MATERIALS AND METHODS: Six patients treated with VGB for partial epileptic seizures refractory to classic anticonvulsant treatment were studied. Gingival biopsies were taken from four of these patients for immunohistochemical studies; 10 control biopsies from individuals with healthy gingiva and 10 from patients with periodontal disease were also evaluated. RESULTS: Four of the six patients presented some degree of gingival enlargement (mild or moderate). Nuclear expression of Ki-67 was elevated (mean of 894 positive cells/mm2 in VGB-induced gingival enlargement vs. 391 cells/mm2 in controls with healthy gingiva and 425 cells/mm2 in controls with periodontal disease) (p < 0.01, analysis of variance: anova), and nuclear expression of cyclin-dependent kinase (cdk) inhibitors p27KIP1 and p21WAF1 was reduced. The patients with gingival enlargement presented inflammatory infiltrate in lamina propria, mainly composed of T lymphocytes (CD3+) and plasma cells (CD38+), which was even more intense than in the biopsies of patients with periodontal disease. CONCLUSION: The overexpression of antigen Ki-67 and slight underexpression of cdk-inhibitors p27KIP1 and p21WAF1 suggest that VGB induced an increase in cell proliferation and contributed, together with concomitant periodontal disease, to the gingival enlargement.

Correlación interlaboratorio en la valoración de la expresión de glicoproteína P en sangre periférica por citometría de flujo / Correlation interlaboratorio in the valoration of the expression of glycoprotein P in blood periferic flow cytometry

La Glicoproteína P (Gp-P) es una proteína transmembranaria con función transportadora, que tiene por misión expeler xenobióticos lipofilíticos. Esta glicoproteína tiene una distribución específica y unos niveles de expresión variables en las células sanguíneas humanas encargadas de la defensa en el organismo. El objetivo de este trabajo fue comparar y establecer si son reproducibles los resultados obtenidos por dos laboratorios distintos en la valoración de la expresión de glicoproteína P (Gp-P) en muestras celulares con baja expresión de esta glicoproteína, como es el caso de las células de sangre periférica. Se valoraron las subpoblaciones celulares de ciento veinticinco (125) muestras de sangre periférica de individuos sanos por citometría de flujo e inmunofluorescencia directa, utilizando el anticuerpo monoclonal JSB-1 conjugando con isotiocianato de fluoresceína (FITC), en dos citómetros de flujo de la misma marca y modelo, situados en dos laboratorios diferentes: Departamento de Anatomía Patológica, Facultad de Medicina, Universidad de Granada y Centro de Transfusión Sanguínea de Granada, España. Los resultados demostraron que la mejor correlación estadística del porcentaje de Positividad (por ciento POS) fue observada en los linfositos (r=0.93), mientras que para la Incorporación Media Fluorescencia Específica (IMFE) se observó en los granulocitos (r=0.94). Los resultados obtenidos con la metodología empleada en la determinación de Gp-P por citometría de flujo e inmunofluorescencia directa, permiten concluir que es una técnica reproducible y fiable para la evaluación del fenómeno de Resistencia Multiple a Drogas (MDR) en las subpoblaciones celulares normales de sangre periférica