The need to educate future dental professionals on E-cigarette effects.

OBJECTIVE: To compare knowledge and attitude of dental students in two countries towards E-cigarettes and their long-term effects. MATERIAL AND METHODS: An anonymous cross-sectional survey, using self-administered questionnaires, was conducted amongst dental students from the University of California, Los Angeles School of Dentistry (UCLA) and Universidad Europea of Madrid (UE). RESULTS: There were significant differences in knowledge and perception of E-cigarettes between dental students from both countries. Three (3%) of the participants from UE sample smoked E-cigarettes every day, compared to none of the students from UCLA. Almost 54 (80%) students from UCLA claimed that they had never experimented with an E-cigarette, whereas 61 (65%) of UE sample reported not having experimented with E-cigarettes in the past. More than 15% of students in both populations were unsure of the potentially harmful effects of E-cigarette usage. A significantly higher proportion of the Spanish sample used conventional cigarettes compared to the US sample 53 (56%) compared to 36 (24%), P < 0.001). In addition, when compared to the UE sample, UCLA students rated E-cigarettes as being less harmful overall than tobacco P < 0.001. Furthermore, more than 86% of both populations indicated interest in learning more about the potential risks associated with E-cigarettes. CONCLUSIONS: This survey indicated that students from one dental school in the United States of America (USA) and one in Spain lacked the knowledge to address the rising E-cigarette population usage and provide information regarding them to patients. Specific educational programmes on E-cigarette hazards and long-term effects on oral and systemic health should be implemented in dental curricula in both of these schools in order to stay receptive to the changing field of tobacco education.

Oral Health Literacy, Preventive Behavior Measures, and Chronic Medical Conditions.

The purpose of this study was to examine the association between oral health literacy, preventive orientation and behaviors, and chronic medical conditions-specifically, hypertension and diabetes. A cross-sectional study was conducted with dental school patients attending the dental clinics in Los Angeles, California, and Baltimore, Maryland. Their health literacy levels were measured using the short Test of Functional Health Literacy in Adults (Short-TOFHLA) and the Rapid Estimate of Adult Literacy in Medicine and Dentistry (REALM-D). The medical history and existing medical conditions-specifically, hypertension and diabetes status-were extracted from patient health history and electronic records. Ten items were asked about preventive behaviors (e.g., brushing teeth in evening, smoking, exercise, drinking soda) and 3 preventive health services (dental checkup, flu shot, medical checkup). Six locus of control items were asked (e.g., good health is a matter of good fortune, what happens to my health is God's will). Out of 793 subjects, 221 had a documented history of hypertension, 88 with diabetes. There was an association between Short-TOFHLA scores and both diabetes and hypertension, but after controlling for sociodemographic and preventive variables, the association was no longer significant. In multivariate analysis, women, people with at least some college, Asians or non-Hispanic Whites, younger people, those who spoke English as a child, those who sought health information from the Internet or health care professionals, and those who smoked reported lower utilization of preventive health services, and those who had less locus of control reported higher Short-TOFHLA scores. There were no significant differences in mean REALM-D scores between patients who had hypertension or diabetes versus not having the condition. Multivariate models showed that people with higher REALM-D scores had at least some college, were other race/ethnicity or non-Hispanic White, spoke English as a child, and sought health information via the Internet. Knowledge Transfer Statement: The results of this study show that dental school patients exhibit a range of health literacy abilities and preventive behaviors, and health literacy measures positively correlated with some preventive behaviors but not others. Dental schools receive a significant number of patients with chronic diseases, and students should be educated to use effective patient communication skills to reinforce positive health behaviors among these patients.

Elevated prolidase activity in keloids: correlation with type I collagen turnover.

BACKGROUND: Keloid pathogenesis involves an altered balance of extracellular matrix metabolism, mainly accumulation of type I collagen. This could be due to excessive synthesis or decreased degradation of matrix, or a combination of both processes. Prolidase, an imidodipeptide-cleaving cytosolic enzyme, plays an important role in the collagen catabolic process by recycling proline for collagen synthesis. Collagen accumulation in keloids is due to an imbalance in the steady state of collagen turnover. OBJECTIVES: To investigate prolidase activity and its role in the steady state of collagen turnover between normal skin and keloid tissue and their derived fibroblasts. METHODS: Ten sets of keloid and normal skin tissues and their derived fibroblasts were employed. Measurements were made of tissue prolidase activity, free proline level, and concentrations of the collagen synthesis product aminoterminal propeptide of type I procollagen (PINP) and the collagen degradative product carboxyterminal telopeptide of type I collagen (ICTP). Also, synthesis of collagens type I and III and matrix metalloproteinases 1 and 2 was investigated using Western blot analysis. RESULTS: Keloid tissues had a significant increase in prolidase activity, up to fourfold that in normal skin. The elevated prolidase activity was accompanied by an increase in tissue PINP and ICTP concentrations in keloid; in addition, the collagen turnover index (PINP/ICTP) was higher in keloids. CONCLUSIONS: The combination of elevated prolidase activity and associated higher collagen synthesis to degradation ratio in keloids suggests a possible metabolic process for the excessive accumulation of type I collagen in keloids.

E-mail-based oral medicine consultation.

A pilot study was undertaken to assess whether text-based electronic patient data transmission (e-mail) is a reliable source of information for the diagnostic decision-making process. The main objective was to determine if information contained within a transmitted text could be reliably used as basis for making general recommendations for diagnostic tests and follow-up or referral plans pertaining to a variety of oral mucosal pathologic conditions. The results suggest that face-to-face patient examination is more accurate in establishing a correct diagnosis for oral mucosal pathologies than transmitted descriptive patient data alone.

Downregulation of apoptosis-related genes in keloid tissues.

BACKGROUND: Physiologically programmed cell death or apoptosis occurs during the natural balance between cellular proliferation and demise. MATERIALS AND METHODS: We compared the expression of 64 apoptosis-related genes in keloids and normal scars to investigate the potential role of apoptosis in keloid formation. Two sets of mRNA were isolated from keloids excised from four previously untreated patients and four normal scar patients separately. Human cDNA arrayed hybridization was performed to compare the apoptosis-related gene expression between these two groups. In addition, TUNEL assays were performed to evaluate the percentage of apoptotic cells in keloids (center and periphery) versus normal scars. RESULTS: Eight of the sixty-four apoptosis-related genes studied were significantly underexpressed in keloid tissue. The underexpressed genes and their relative expression compared with normal scar were defender against cell death 1 (DAD-1) (34.1% of normal scar); nucleoside diphosphate kinase B (c-myc transcription factor) (24.7%); glutathione S-transferase (17.9%); glutathione S-transferase microsomal (28.1%); glutathione peroxidase (47.2%); tumor necrosis factor receptor 1-associated protein (TRADD) (51.0%); 19-kDa interacting protein 3 (NIP3) (36.0%); and cytoplasmic dynein light chain 1 (HDLC1) (47.7%). Spatial analysis of apoptosis using TUNEL assays revealed apoptosis indices of 0.83 for keloid periphery and 0.63 for keloid center. CONCLUSIONS: In this study we demonstrated underexpression of apoptosis-related genes in human keloid tissue and decreased apoptotic activity in fibroblasts derived from keloids versus normal scars. We hypothesized that keloid fibroblasts fail to undergo physiologically programmed cell death and, thus, continue to produce and secrete connective tissue beyond the period expected in normal scar formation, accounting for the progressive and hypertrophic nature of keloids. This mechanism leads to new possibilities for treatment of keloids through induction of apoptosis.

Expression of apoptosis-associated genes by human dermal scar fibroblasts.

The purpose of this study was to determine if aberrant apoptosis plays a role in pathologic wound healing as manifested by hypertrophic scarring and keloid formation. Apoptosis has recently been found to participate in the transition between granulation tissue and the development of definitive scar. The question that remains to be answered is what stimuli initiate apoptosis during wound healing. Hitherto, regulatory factors and pathways involved have been largely undefined. We investigated heterogeneity among fibroblasts derived from normal skin and keloid scar, by examining apoptotic profiles and pathways for these cells. Quantitative analysis of apoptotic cells using an Annexin-V-FITC binding assay showed that normal skin fibroblast cultures were found to have a two-fold higher percentage of apoptotic cells than did keloid fibroblast cultures. To study apoptotic pathways and related death-associated genes, a ribonuclease protection assay was performed for fibroblasts exposed to anti-Fas antibody and tumor necrosis factor-alpha to activate the Fas/TNF receptor apoptotic pathway. Compared with normal skin fibroblasts, keloid fibroblasts exhibited decreased expression of apoptosis-associated genes.

Effect of TGF-beta 1 on PDGF receptors expression in human scar fibroblasts.

This study examined the effect of exogenous TGF -beta1 on platelet derived growth factor alpha and beta (PDGF-alpha, beta) receptor expression in human dermal fibroblasts derived from both normal cutaneous tissues (normal skin [NSk]) and (normal scar [NSc]) and abnormal scar (keloid). TGF-beta and PDGF are present in the early phases of wound healing and are implicated in tissue fibrosis. In this study, replicate samples of NSk, NSc and keloid fibroblasts were grown to subconfluency in DMEM/10% FBS followed by replacement of media with DMEM/0.1%FBS for 24 hrs. One group of cells (NSk, NSc and keloid) were exposed to 10 ng/mL of exogenous TGF-beta1 for 24 hours, while the other group was used as control with no exposure to exogenous TGF-beta1. RadioImmunoBinding assays, Western and Northern blot analysis were performed to examine both PDGF-alpha and PDGF-beta receptor expression at the transcriptional and post-transcriptional levels. cDNA receptor probes were synthesized using polymerase chain reaction (PCR) with selected primer sets derived from published sequences. Beta-actin probe was used as a control to confirm that the same quantity of RNA was used for each experimental condition. TGF-beta1 was found to upregulate the expression of PDGF-alpha receptor for keloid fibroblasts but not for NSk or NSc fibroblasts. No effect was observed for TGF-beta 1 on PDGF-beta receptor expression for any of the cell lines examined.

Oral and nonoral sources of halitosis.

Oral malodor (halitosis, bad breath) is a condition affecting millions of Americans. In healthy individuals complaining of bad breath, the mouth is the main source of their oral malodor, more specifically the posterior dorsum of the tongue. Nonoral sources should also be considered. It is always easy to recognize halitosis, but identifying the exact cause is more complex.

Detecting and treating oral and nonoral malodors.

This article suggests methods on how to detect and treat the various oral and nonoral malodor conditions with which patients present. These conditions are separated into those emanating from the nasal passage, sinuses and upper respiratory sources; the mouth; the tongue; the oropharynx; the lower respiratory tract; and the lungs. Foul odors also develop as a result of systemic and gastrointestinal disorders and diseases, as well as the normal breakdown of odiferous ingested foods. The available detection methods are described and future methods are suggested. The overall conclusions made from this review are that currently available management methods will be able to treat most cases. A careful, knowledgeable clinician can usually determine the patient's problem by the use of a thorough history and examination. Occasionally medical consults will be needed; and, in these cases, the approach that must be taken is a combined treatment approach. For example, effective therapy might require a combination of periodontal disease treatment, correction of dental restoration-based food traps and a rigorous daily mechanical debridement of the tongue. The above treatments will often have to be supplemented by the most appropriate mouthwash for the patient's specific condition. Finally, this article hopes to encourage manufacturers of "halitosis products" to support and conduct well-designed clinical trials on their products so that the field is advanced and treatments become more predictable.

Autocrine transforming growth factor-beta(1) activity and glycosaminoglycan synthesis by human cutaneous scar fibroblasts.

Transforming growth factor-beta(1) is a well-known and potent biological response modifier that plays an important role in tissue repair and fibrosis. Among the extracellular constituents known to accumulate in fibrotic tissues, glycosaminoglycans are prominent. In this study we examined transforming growth factor-beta(1) synthesis by human dermal fibroblasts derived from both normal and fibrotic cutaneous tissues. We studied the influence of transforming growth factor-beta(1) on glycosaminoglycan synthesis and explored the role of transforming growth factor-beta(1) as an autocrine mediator of its own expression. These investigations are directed at understanding the persistence of the fibrotic phenotype in scarred skin. Transforming growth factor-beta(1) activity was measured by means of a mink lung epithelium growth inhibitory assay. Replicate explants (n = 3) of fibroblasts each derived from normal skin, normal scar, or hypertrophic scar were studied by adding exogenous transforming growth factor-beta(1) at a concentration range of 0 to 10 ng/ml. The resulting conditioned media were removed and assayed for transforming growth factor-beta(1) activity, then the cells were pulsed for an additional 24 hours with radiolabeled glycosaminoglycan precursor, [(3)H]-glucosamine, to evaluate glycosaminoglycan production. Cell-free glycosaminoglycan synthetic profiles were also developed. Transforming growth factor-beta(1) was found to cause a dose-dependent increase in glycosaminoglycan synthesis in hypertrophic scar and normal skin but not in normal scar fibroblasts in cell-mediated glycosaminoglycan synthesis; the reverse was observed in cell-free glycosaminoglycan synthesis, where transforming growth factor-beta(1) increased glycosaminoglycan synthesis in normal scar but not in normal skin or hypertrophic scar. Most endogenous transforming growth factor-beta(1) existed in latent form for normal skin cells but in active form for normal scar and hypertrophic scar fibroblasts.

The role of proteoglycans in hard and soft tissue repair.

Healing of soft and hard tissues results from a progression of events initiated by injury and directed toward reestablishing normal structure and function. The ubiquity of proteoglycans in mammalian tissues virtually guarantees their involvement in tissue restitution. The dramatic advances in cellular and molecular biology in recent years have added significantly to understanding the specific roles played by proteoglycans in wound repair processes.

CD44 and hyaluronan expression in human cutaneous scar fibroblasts.

Fibrotic disorders of skin and other organs are typically associated with an abnormal accumulation of extracellular matrix. This study focuses on a matrix constituent, hyaluronan-which is known to be altered in fibrotic disorders of skin- and on CD44, a cell adhesion molecule and putative receptor for hyaluronan. Tissue samples were obtained from biopsies of human normal skin, normal cutaneous scar; and hypertrophic cutaneous scar. After culturing, cells were studied by single- and double-labeling immunohistochemistry using the two anti-CD44 monoclonal antibodies, BU-52 and J173, and a biotinylated hyaluronan binding complex probe, b-HABR. Certain cultures were pretreated with Streptomyces hyaluronidase to assess the dependency of CD44 expression on the presence of endogenous hyaluronan. CD44 expression, both in the presence and the absence of exogenous hyaluronan, was quantitated by radioimmunobinding assay. Overall glycosaminoglycan synthesis and identification of hyaluronan were accomplished by precursor incorporation assays and by quantitative cellulose acetate electrophoresis. CD44 was found to be a normal human adult fibroblastic antigen whose expression is markedly increased for hypertrophic scar fibroblasts compared with normal skin fibroblasts. Although hyaluronan was found to be the predominant glycosaminoglycan constituent of the pericellular matrix for these fibroblasts, CD44 attachment to the cell surface is neither mediated by hyaluronan nor is the presence of hyaluronan a prerequisite for CD44 expression. Exogenous hyaluronan induced a decline in measurable CD44 expression for normal skin fibroblasts but not for hypertrophic scar fibroblasts. These observations are compatible with current understanding of the way cells manage the hyaluronan economy of the extracellular matrix and emphasize phenotypic heterogeneities between fibroblasts derived from normal versus scar tissues.

Binding and internalization of hyaluronate by human cutaneous fibroblasts.

Hyaluronate is a ubiquitous component of mammalian extracellular matrix. It influences numerous cellular processes and accumulates in fibrotic connective tissue disorders. Recently, hyaluronate catabolism has assumed additional importance because of the introduction into clinical practice of therapeutic procedures which deposit high concentrations of hyaluronate directly into tissues. Relatively little is known about the local metabolism, fate, or long-term effects of either endogenous or exogenous hyaluronate at deposition sites. A capacity for degrading hyaluronate within connective tissues, presumably by fibroblasts, has been inferred but remains controversial because direct proof that human fibroblasts endocytose and degrade hyaluronate has been lacking. In the present study, fibroblasts from normal and fibrotic skin were incubated with [3H]-hyaluronate. Binding and internalization of radiolabeled substrate were then measured: Binding assays revealed a saturable, dose-dependent increase in cell surface-associated [3H]-hyaluronate which was enhanced by pretreatment with hyaluronidase. Similar binding curves were obtained for all cells tested. All the cell lines internalized hyaluronate; however, fibroblasts in confluent cultures internalized 3.5- to 4.2-fold more radioactivity per cell than did fibroblasts from corresponding subconfluent cultures (p less than or equal to 0.002). Normal scar fibroblasts showed greater capacity for generating hyaluronate-derived partial degradation products. This work provides clear evidence that human cutaneous fibroblasts are capable of both binding and internalizing hyaluronate, possibly as a prerequisite for degradation.

General principles of healing pertinent to the periodontal problem.

The healing process involves a series of coordinated procedures initiated by injury and directed toward restoring structural and functional integrity of the disrupted tissues. Wound healing begins immediately after tissue injury occurs and requires close control of degenerative and regenerative processes, which involve numerous cell types and complex interactions between multiple biochemical cascades.

Effects of recombinant gamma-interferon on HLA-DR and DQ expression by skin cells in short-term organ culture.

We studied the effects of various immunologic and inflammatory mediators on the expression of the class II major histocompatibility antigens, HLA-DR and DQ in short-term organ cultures of newborn human foreskin. Induction of these molecules above baseline was observed preponderantly on microvascular endothelium and epidermal dendritic cells, and among the mediators tested, this induction was caused exclusively by immune interferon. Increased reactivity for HLA-DR and DQ was observed at 24 hours for both cell types. Double labeling confirmed that the HLA-DR/DQ-positive dendritic cell population consisted largely of T6-positive Langerhans cells. Peak endothelial HLA-DR expression was seen at 24 hours and slowly dissipated thereafter. In contrast, endothelial HLA-DQ showed increasing expression over 72 hours of the study. Keratinocytes remained unreactive for HLA-DR and DQ during the entire study period. We conclude that class II major histocompatibility molecules can be modulated on skin microvascular endothelial cells and Langerhans cells in situ by immune interferon with response rates different from those previously described for endothelium in cell culture. Furthermore, the organ culture system has revealed keratinocyte unresponsiveness not anticipated from cell culture experiments. These findings have implications for the effector function and potential targeting of these cells in the cutaneous immune response, and establishes short-term organ culture of human skin as a valuable model for assessment of interactions between cytokines and skin cells.

Induction of an activation antigen on postcapillary venular endothelium in human skin organ culture.

We studied the effects of the immune mediators interleukin 1, interleukin 2, tumor necrosis factor, immune interferon, and lipopolysaccharide on the expression of the endothelial activation antigen recognized by the murine monoclonal antibody H4/18 in short term organ cultures of newborn foreskins. No endothelial staining was detectable before culture. Interleukin 1, tumor necrosis factor, and lipopolysaccharide each induced 2+ to 3+ H4/18 staining of microvascular endothelium at 6 hr. Combining mediators produced additive (3+ to 4+) effects, and reactivity was lost or markedly diminished by 24 hr. Incubation with culture medium alone resulted in 1+ to 2+ H4/18 staining at 6 hr, and medium conditioned by cultured foreskins, but not mock-conditioned medium, could induce H4/18 binding in cultured human umbilical vein endothelial cells. The spontaneous expression of microvascular staining in the foreskins was markedly inhibited by cyclosporin A, but not polymyxin B sulfate or dexamethasone; cyclosporin A did not inhibit induction of staining by exogenous mediators. Both light level and immunoultrastructural studies demonstrated H4/18 expression to be associated predominantly with postcapillary venular endothelial cells of the superficial vascular plexus. We conclude that microvascular endothelium of skin can undergo activation in response to exogenous and endogenous cytokines, with the greatest changes occurring in those portions of the vessels most involved in leukocyte and lymphocyte trafficking.

Acute cutaneous graft-versus-host disease to minor histocompatibility antigens in a murine model. Evidence that large granular lymphocytes are effector cells in the immune response.

We studied the morphologic and immunophenotypic characteristics of inflammatory infiltrates in the skin of mice with acute graft-versus-host disease induced by bone marrow transplantation between strains differing only in minor histocompatibility antigens. The strain combinations employed (B10.Br - greater than CBA) have been shown to produce a lethal graft-versus-host disease with clinical severity proportional to the number of T lymphocytes added to the donor marrow inoculum. Transplant recipients developed pronounced clinical signs of graft-versus-host disease, including copious diarrhea and weight loss, and histologic alterations in skin strikingly similar to this disease in humans. Our findings indicate that the preponderant mononuclear cell in lesional skin from these animals has phenotypic characteristics of a natural killer cell. This cell was often found in apposition with necrotic epidermal cells. The origin, function, and potential relevance of natural killer cells in lesion formation in this experimental model are discussed.

Phenotypic transformation of macrophages to Langerhans cells in the skin.

Langerhans cells, important participants in the cutaneous cellular immune response, are markedly diminished in skin of patients undergoing allogeneic bone marrow transplantation during the first 4 weeks after this procedure. To determine the mechanism responsible for the subsequent repopulation of these cells, the authors studied the immunophenotypic and morphologic profiles of sequential skin biopsies during the posttransplantation period. Cells with surface antigens of monocytes/macrophages within the superficial dermis were gradually replaced by dermal and epidermal dendritic cells exhibiting coexpression of monocyte/macrophage and Langerhans cell surface antigens. Ultrastructural examination revealed that many of these cells contained both prominent phagolysosomes and Birbeck granules. Antigenically and structurally mature Langerhans cells were observed within the epidermis by the end of the second month after transplantation. Phenotypic transformation of phagocytic dermal macrophages to Langerhans cells appears to represent a mechanism for repopulation of Langerhans cells during the period of immunologic reconstitution in this patient population.

Inhibition of oral carcinogenesis by a protease inhibitor.

The effect of the Bowman-Birk inhibitor (BBI) and soybean trypsin inhibitor (SBTI) on experimental 7,12-dimethylbenz[a]anthracene [(DMBA) CAS: 57-97-6]-induced oral carcinogenesis in Syrian male hamsters was examined. All treatments were applied topically on both cheek pouches for 20 weeks, and the animals were then sacrificed. Gross and microscopic evaluations revealed a statistically significant reduction in the number of invasive carcinomas, the total number of tumors, and the tumor mass for the DMBA + BBI treatment group compared to animals treated with DMBA alone, DMBA and autoclaved BBI (a preparation in which protease inhibitor activity is destroyed), or DMBA + SBTI. A protease activity (with the use of Boc-Val-Pro-Arg-MCA as substrate) was measured and found to be elevated about tenfold in tumorous and nontumorous tissue from DMBA-treated cheek pouches. This protease activity was found to be decreased in the DMBA and BBI treatment group but not in the DMBA + SBTI or DMBA and autoclaved BBI treatment groups, as compared to the protease activity in the DMBA treatment group. Partial characterization of the Boc-Val-Pro-Arg-MCA hydrolyzing activity with diisopropyl fluorophosphate suggests that the proteolytic activity is a serine protease. Iodoacetamide and diethyl pyrocarbonate also inhibit enzyme activity, suggesting that other residues may be necessary for catalysis, possibly including cysteine and histidine. Our results suggest that this protease activity may play a role in DMBA-induced cheek pouch carcinogenesis.