Comparison of differentiation markers between normal and two squamous cell carcinoma cell lines in culture.

This study examines differences between cultures of normal human oral epithelial cells and two squamous cell carcinoma cell lines (SCC15 and SCC25) in the expression of structural proteins, adhesion molecules, plasma membrane lipid composition, and intercellular junctions. Based on immunocytochemistry, most normal cell cultures appeared to express more E-cadherin, integrin beta-1, cytokeratin (CK) 14, CK19, and involucrin than SCC cultures. By Western blot analysis, normal cultures expressing high levels of E-cadherin also expressed high levels of involucrin and low levels of CK19. Both SCC cultures demonstrated lower expression of E-cadherin and involucrin, whereas only SCC15 cells showed high levels of CK19. Expression of beta-catenin, an E-cadherin associated protein with potential oncogene function, did not vary among normal and SCC cells. Proportions of saturated fatty acids quantified by thin layer chromatography were higher in the normal cell cultures, than in both SCC cell lines. No morphological differences were evident by transmission electron microscopy (TEM) between normal and SCC cell-cell intercellular junctions. Although no quantitation was attempted, observation suggested that normal cells form more intercellular junctions (TEM observation) and larger intercellular bridges (SEM observation) compared to both SCC cell lines. Of the factors examined, main variations between cultures of normal oral epithelium and the two SCC cell lines examined include the expression of structural and adhesion proteins, lipid composition, and intercellular junctions. The extent of the differences varies according to the stage of terminal differentiation demonstrated by the normal cell cultures.

Smoking and disease.

Tobacco represents the single most preventable cause of disease and death in the world today. The countries of Central Europe bear a disproportionate burden of tobacco-related morbidity and mortality. For example, some of the highest rates worldwide of cigarette consumption and smoking prevalence are in the Czech Republic, Hungary and Romania. This chapter first describes the extent of tobacco use in five central European countries, the Czech Republic, Hungary, Poland, Romania and Slovakia and then considers mortality from tobacco related disease. Data from two diseases, lung cancer and oral cancer, which result almost exclusively from tobacco use are considered. Finally, the relationship between tobacco use and oral disease is discussed.

Tobacco control and the role of the medical community in the Slovak Republic.

The Slovak Republic (SR) is located in central Europe and has a population of about 5.4 million. Epidemiological data indicate that trends in smoking prevalence and incidence of lung cancer have not shown any tendency to decrease in the SR. Surveys of Martin residents and of medical students at Comenius University provided important data on many aspects of cigarette smoking and tobacco dependence and served as a basis for planning and implementing focused tobacco control activities at the regional and national levels. The activities were focused not only on the Slovak public but also the medical community. With assistance from international organizations, Slovak doctors are learning to take direct responsibility for treatment and prevention and also a public responsibility to influence governmental policies. As a result, tobacco control activities in the SR enjoy collaboration between different agencies, community participation and personal involvement of health professionals.

Engineering clinician leadership and success in tobacco control: recommendations for policy and practice in Hungary and Central Europe.

Decades of research and advocacy to control tobacco use and related public-health harm have not counterbalanced the tobacco industry's successful stronghold, which is ever-increasing in countries with weaker anti-tobacco leadership. Current rates of tobacco use and harm in Hungary and other Central European countries mark them as some of the industry's greater successes. Following the Behavioural Ecological Model, a framework for behavioural and cultural change, this paper reviews important ways that dentists, physicians and other healthcare providers can counter the tobacco industry's influence on patients, communities, and the nation. The analysis includes policies and practices shown to be effective in controlling and undermining the tobacco industry, and outlines new policies and practices that show promise based on the behavioural change framework. The components of an all-encompassing tobacco-control programme are described through explicit recommendations for research, practice and policy that are necessary to establish a professional and societal culture that extinguishes the influence and harm of the tobacco industry in Hungary, Central Europe and developing countries worldwide.

Subcellular localization of beta-catenin in malignant cell lines and squamous cell carcinomas of the oral cavity.

BACKGROUND: Beta-catenin, an E-cadherin-associated protein involved in cell-cell adhesion and signaling, has been hypothesized to translocate to the nucleus and activate transcription in several human cancers, including oral squamous cell carcinomas (OSCC). METHODS: In the present study, we analyzed the subcellular localization of beta-catenin in cultures of human oral normal and malignant (cell lines SCC15 and SCC25) keratinocytes and in 24 frozen samples of oral squamous cell carcinomas by a double-staining technique for nucleic acids and beta-catenin. Growth potential, as assessed by cell count at different time periods, was established for normal, SCC15 and SCC25 cell lines; oral squamous cell carcinomas were classified according to the histopathological and malignancy indexes. RESULTS: Beta-catenin localized at the plasma membrane in the normal and SCC15 cells, not in the SCC25 cells, where it localized mostly in the perinuclear and nuclear areas. In the growth assays, SCC25 cell lines proliferated faster than in normal and SCC15 cells over a period of 6 days (cell numbers were significantly different, P < 0.0001). Carcinoma sections showed a combination of membranous, cytoplasmic and, in few invading epithelial islands of two tumors, nuclear localization of beta-catenin. CONCLUSIONS: In oral squamous cell carcinomas, nuclear beta-catenin staining was observed only within invading islands of two carcinomas deep in the underlying connective tissue. On the basis of this study, we conclude that intranuclear beta-catenin does not appear to be a common finding in oral squamous cell carcinomas and that a clear association between intranuclear beta-catenin and histopathological and malignancy indexes in vivo could not be established.

Biology of oral mucosa and esophagus.

The mucosal lining of the oral cavity and esophagus functions to protect the underlying tissue from mechanical damage and from the entry of microorganisms and toxic materials that may be present in the oropharynx. In different regions, the mucosa shows adaptation to differing mechanical demands: Masticatory mucosa consists of a stratified squamous keratinized epithelium tightly attached to the underlying tissues by a collagenous connective tissue, whereas lining mucosa comprises a nonkeratinized epithelium supported by a more elastic and flexible connective tissue. The epithelium is constantly replaced by cell division in the deeper layers, and turnover is faster in the lining than in the masticatory regions. Chemotherapeutic agents and radiation limit proliferation of the epithelium so that it becomes thin or ulcerated; this will first occur in the lining regions. The principal patterns of epithelial differentiation are represented by keratinization and nonkeratinization. As keratinocytes enter into differentiation, they become larger and begin to flatten and to accumulate cytokeratin filaments. In addition to the keratins, the differentiating keratinocytes synthesize and retain a number of specific proteins, including profilaggrin, involucrin, and other precursors of the thickening of the cell envelope in the most superficial layers. The concept of epithelial homeostasis implies that cell production in the deeper layers will be balanced by loss of cells from the surface. There is a rapid clearance of surface cells, which acts as a protective mechanism by limiting colonization and invasion of microorganisms adherent to the mucosal surface.

Permeability barrier properties of oral keratinocyte cultures: a model of intact human oral mucosa.

OBJECTIVES: The aim of this study was to establish whether an in vitro model of human oral mucosa had similar permeability characteristics to normal oral mucosa. Such a model would have considerable value as an alternative to the use of mucosal biopsies in studies of transmucosal drug delivery. MATERIALS AND METHODS: Keratinocytes obtained from buccal mucosa, hard palate and abdominal skin were seeded onto inert collagen membranes (Cellagen Discs) or dead de-epidermised dermis (DDED) and grown either as submerged or air-liquid interface cultures. Subsequently the ultrastructural characteristics, permeability to water and barrier lipid content of the epithelial cultures were assessed and compared with samples of intact mucosa and skin. RESULTS: All the cultures stratified into multilayered epithelia and displayed features of differentiation including tonofilaments, desmosomes and membrane coating granules. The permeability characteristics and barrier lipid content of the oral mucosal cultures resembled those of intact mucosa. By contrast, epidermal keratinocytes failed to produce a permeability barrier comparable with that of skin and had low levels of barrier associated lipids. CONCLUSIONS: Cultures of human oral mucosal keratinocytes obtained from healthy adults develop similar permeability properties and barrier lipid composition to their site of origin. This model system may be useful for the evaluation of local and systemic oral mucosal drug delivery.

Delivery of bioactive peptides and proteins across oral (buccal) mucosa.

The identification of an increasing array of highly potent, endogenous peptide and protein factors termed cytokines, that can be efficiently synthesized using recombinant DNA technology, offers exciting new approaches for drug therapy. However, the physico-chemical and biological properties of these agents impose limitations in formulation and development of optimum drug delivery systems as well as on the routes of delivery. Oral mucosa, including the lining of the cheek (buccal mucosa), floor of mouth and underside of tongue (sublingual mucosa) and gingival mucosa, has received much attention in the last decade because it offers excellent accessibility, is not easily traumatized and avoids degradation of proteins and peptides that occurs as a result of oral administration, gastrointestinal absorption and first-pass hepatic metabolism. Peptide absorption occurs across oral mucosa by passive diffusion and it is unlikely that there is a carrier-mediated transport mechanism. The principal pathway is probably via the intercellular route where the major permeability barrier is represented by organized array of neutral lipids in the superficial layers of the epithelium. The relative role of aqueous as opposed to the lipid pathway in drug transport is still under investigation; penetration is not necessarily enhanced by simply increasing lipophilicity, for other effects, such as charge and molecular size, also play an important role in absorption of peptide and protein drugs. Depending on the pharmacodynamics of the peptides, various oral mucosal delivery systems can be designed. Delivery of peptide/protein drugs by conventional means such as solutions has some limitations. The possibility of excluding a major part of drug from absorption by involuntary swallowing and the continuous dilution due to salivary flow limits a controlled release. However these limitations can be overcome by adhesive dosage forms such as gels, films, tablets, and patches. They can localize the formulation and improve the contact with the mucosal surface to improve absorption of peptides and proteins. Addition of absorption promoters/permeabilizers in bioadhesive dosage forms will be essential for a successful peptide/protein delivery system.

Control of an outbreak of infection due to extended-spectrum beta-lactamase--producing Escherichia coli in a liver transplantation unit.

We report an outbreak of infection due to genotypically identical extended-spectrum beta-lactamase--producing Escherichia coli among patients in a liver transplantation unit. Control of the outbreak was achieved by a combination of contact isolation, feedback on hand hygiene, and gut decontamination with an orally administered fluoroquinolone. These interventions led to abrupt curtailment of the outbreak.

Short-term exposure to alcohol increases the permeability of human oral mucosa.

OBJECTIVES: The aim of this study was to evaluate the effect of short-term exposure to ethanol on the permeability barrier properties of human oral mucosa. MATERIALS AND METHODS: Permeability constants (Kp x 10(-4) cm min(-1)) to tritiated water were determined, for untreated human ventral tongue, and following treatment with phosphate-buffered saline (PBS), 5, 15 or 40% ethanol using an in vitro perfusion chamber system. Some samples were also exposed to fluorescent-labelled albumin and examined by fluorescence microscopy. Permeability barrier lipid composition was assessed in treated and untreated mucosa by heat separation, solvent extraction and thin layer chromatography. RESULTS: Fifteen per cent ethanol significantly increased mucosal permeability (5.8 +/- 0.44; P < 0.05) compared with untreated, PBS and 5% ethanol treated mucosa (4.69 +/- 0.26, 4.48 +/- 0.3 and 4.13 +/- 0.27, respectively). Albumin was restricted to the epithelial surface in control tissue, but extended further through the epithelium and, in some cases, into the connective tissue after treatment with ethanol. Biochemical analysis revealed no significant difference in the epithelial lipid composition of treated and untreated mucosa. CONCLUSIONS: These results suggest that short-term exposure to ethanol may act as a permeability enhancer, possibly by causing molecular rearrangement of the permeability barrier, not as a result of lipid extraction.

Waterborne Nosocomial Infections.

Waterborne pathogens cause infections in health-care facilities. Despite guidelines addressing these pathogens, outbreaks and pseudo-outbreaks continue to occur. We reviewed recent reports of infections caused by Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Chryseobacterium species, nontuberculous mycobacteria, and Legionella species. Mycobacterium avium complex (MAC) infection in HIV patients has been linked to hospital water distribution systems; molecular subtyping showed that MAC isolates in patients and hospital water were identical. In immunosuppressed patients, Fusarium infection has been linked to the hospital water distribution system; again molecular subtyping showed that isolates from patients and the water supply were identical. Parasites, especially Cryptosporidium, and viruses have also been implicated in nosocomial infection. Transmission occurs via contact, ingestion, aspiration, or aerosolization of potable water, or via the hands of health-care workers. Interventions designed to interrupt transmission of waterborne pathogens have included the use of antimicrobial handwashes, targeted disinfection of the water supply, and, in high-risk populations, restricting the use of tap water.

Enhancing effect of chitosan on peptide drug delivery across buccal mucosa.

The buccal mucosa represents a potentially important topical route for delivery of peptide or protein drugs with some unique advantages such as the avoidance of hepatic first-pass metabolism and the acidity and protease activity encountered in the gastrointestinal tract. However, the bioavailabilities or relative potencies of intraorally administered peptides are usually quite low, unless permeabilizers are employed. Chitosan, a mucopolysaccharide of marine origin, has been claimed to act both as a bioadhesive and permeabilizer, making it a candidate system for mucosal drug delivery. In this study, the enhancement effect of chitosan in gel form for oral mucosa was investigated with a large bioactive peptide, transforming growth factor-beta (TGF-beta). Chitosan gel was prepared at 2% concentration in dilute lactic acid and TGF-beta was incorporated into the gel. The effect of chitosan as a permeabilizer was determined by measuring the flux of TGF-beta across porcine oral mucosa in an in vitro system. The localization of TGF-beta within the oral mucosa was determined by horizontal sectioning and counting. Chitosan was found to exert a marked permeabilizing effect on buccal mucosa for peptide drug.

Adherence to protease inhibitor therapy and outcomes in patients with HIV infection.

BACKGROUND: Combination antiretroviral therapy with protease inhibitors has transformed HIV infection from a terminal condition into one that is manageable. However, the complexity of regimens makes adherence to therapy difficult. OBJECTIVE: To assess the effects of different levels of adherence to therapy on virologic, immunologic, and clinical outcome; to determine modifiable conditions associated with suboptimal adherence; and to determine how well clinicians predict patient adherence. DESIGN: Prospective, observational study. SETTING: HIV clinics in a Veterans Affairs medical center and a university medical center. PATIENTS: 99 HIV-infected patients who were prescribed a protease inhibitor and who neither used a medication organizer nor received their medications in an observed setting (such as a jail or nursing home). MEASUREMENTS: Adherence was measured by using a microelectronic monitoring system. The adherence rate was calculated as the number of doses taken divided by the number prescribed. Patients were followed for a median of 6 months (range, 3 to 15 months). RESULTS: During the study period, 45,397 doses of protease inhibitor were monitored in 81 evaluable patients. Adherence was significantly associated with successful virologic outcome (P < 0.001) and increase in CD4 lymphocyte count (P = 0.006). Virologic failure was documented in 22% of patients with adherence of 95% or greater, 61% of those with 80% to 94.9% adherence, and 80% of those with less than 80% adherence. Patients with adherence of 95% or greater had fewer days in the hospital (2.6 days per 1000 days of follow-up) than those with less than 95% adherence (12.9 days per 1000 days of follow-up; P = 0.001). No opportunistic infections or deaths occurred in patients with 95% or greater adherence. Active psychiatric illness was an independent risk factor for adherence less than 95% (P = 0.04). Physicians predicted adherence incorrectly for 41% of patients, and clinic nurses predicted it incorrectly for 30% of patients. CONCLUSIONS: Adherence to protease inhibitor therapy of 95% or greater optimized virologic outcome for patients with HIV infection. Diagnosis and treatment of psychiatric illness should be further investigated as a means to improve adherence to therapy.

Penetration of N-nitrosonornicotine (NNN) across oral mucosa in the presence of ethanol and nicotine.

The effects of ethanol concentrations of 5, 15, 20, 25, 27, 30 and 50% on the penetration of the tobacco-specific carcinogen, nitrosonornicotine (NNN), across porcine oral mucosa were examined using an in vitro perfusion system. Concentrations of ethanol of 25% and above significantly increased the permeability of oral mucosa to NNN, although this increase ceased with 50% ethanol, possibly due to a fixative effect. Nicotine is a consistent component of smoked and smokeless tobacco; the presence of 0.2% nicotine significantly increased the permeability of oral mucosa to NNN and 2% nicotine caused a further increase. Combined use of nicotine and ethanol significantly increased the penetration of NNN across oral mucosa over that of ethanol alone until the concentration of ethanol reached 50%. The results of this study suggest that the synergy between tobacco and alcohol in the etiology of oral cancer may be explained, at least in part, by the local permeabilizing effects of alcohol on the penetration of tobacco-specific (and other) carcinogens across oral mucosa.

Methicillin-resistant Staphylococcus aureus: the other emerging resistant gram-positive coccus among liver transplant recipients.

We undertook a study of the characteristics and clinical impact of infections due to methicillin-resistant Staphylococcus aureus (MRSA) after liver transplantation. Of 165 patients who received liver transplants at our institution from 1990 through 1998, 38 (23%) developed MRSA infections. The predominant sources of infection were vascular catheters (39%; n=15), wound (18%; n=7), abdomen (18%; n=7), and lung (13%; n=5). A significant increase in MRSA infections (as a percentage of transplant patients infected per year) occurred over time (P=.0001). This increase was greater among intensive care unit patients (P=.001) than among nonintensive care unit hospital patients (P=.17). Cytomegalovirus seronegativity (P=.01) and primary cytomegalovirus infection were significantly associated with MRSA infections (P=.005). Thirty-day mortality among patients with MRSA infections was 21% (8/38). Mortality was 86% in patients with bacteremic MRSA pneumonia or abdominal infection and 6% in those with catheter-related bacteremia (P=.004). Thus the incidence of MRSA infection has increased exponentially among our liver transplant recipients since 1990. These infections have unique risk factors, time of onset, and a significant difference in site-specific mortality; deep-seated bacteremic infections, in particular, portend a grave outcome.

Adherence of human immunodeficiency virus-infected patients to antiretroviral therapy.

The impact of demographic, psychosocial, and medical regimen-related variables on adherence of 123 human immunodeficiency virus (HIV)-infected patients to antiretroviral therapy was assessed by means of refill methodology. Satisfaction with social support (P = .029), problem-focused coping (P = .027), and active-behavioral coping (P = .011) correlated significantly with adherence, whereas loss of motivation (P = .006), hopelessness (P = .16), and avoidant coping (p = .015) correlated with nonadherence. At the 6-month follow-up, the mean CD4 cell count differed significantly among adherent versus nonadherent patients (a mean increase of 78/mm3 vs. a mean decrease of 5/mm3; P = .018). Adherence did not correlate with the number of antiretroviral medications consumed per day (mean, 3.0 vs. 2.5). Non-Caucasian patients were more likely to be nonadherent than Caucasian patients (relative risk, 2.5; 95% confidence interval, 1.2-5.3; P = .013); this difference was not explained by age, education, employment, income, history of intravenous drug use, or medical regimen. Non-Caucasian patients, however, were less satisfied with their social support (P = .04) and informational support (P = .016) and were more likely to utilize emotion-focused coping (P = .01). Thus, satisfaction with social support and coping style significantly impacted adherence and likely accounted for the observed racial difference in adherence among HIV-infected patients.

Oral mucosal permeability and stability of transforming growth factor beta-3 in vitro.

PURPOSE: To investigate the permeability and localization of topically applied 125I-TGF-beta3 in porcine floor-of-mouth mucosa as a function of concentration and exposure. METHODS: The 125I-TGF-beta3 diluted in three different vehicles was applied to the tissue samples mounted in perfusion cells maintained at 37 degrees C. Flux and Kp values were calculated from the perfusate collected over a 24 hour period. The quantity of 125I-TGF-beta3 present in the tissue was determined by horizontal sectioning and subsequent counting. The stability of 125I-TGF-beta3 in saliva and in the tissue was analyzed by SDS polyacrylamide gradient gel electrophoresis. RESULTS: 125I-TGF-beta3 was relatively stable in saliva and in the epithelium; approximately 50% of the total counts in the deeper epithelium were resident in the 25kDa TGF-beta3 homodimer. A steady-state flux was reached approximately 6 hours post application and Kp value was 4.0+/-0.6 x 10(-6) (mean +/- sem). Penetration of 125I-TGF-beta3 to the basal cell layer was concentration dependent but reached nanomolar concentrations even after extensive surface rinsing, representing over one-thousand fold the IC50 for epithelial cell cycle arrest. CONCLUSIONS: The data suggest that topical application of TGF-beta3 to the oral mucosa in an appropriate vehicle can provide effective therapeutic delivery to the tissue.

Quality of life in patients with human immunodeficiency virus infection: impact of social support, coping style and hopelessness.

We aimed to determine whether the quality of life (QOL) in the patients infected with human immunodeficiency virus (HIV) infection was influenced by satisfaction with social support, coping style and hopelessness. One hundred and thirty-eight HIV-infected patients were prospectively studied in this multicentre, longitudinal study. The QOL was assessed by Medical Outcome Study Health Survey SF-36, social support by Sarason Social Support Questionnaire, hopelessness by Beck Hopelessness Scale, and coping by Billing and Moos Inventory of coping with illness. The QOL did not correlate with age, sex, race, HIV risk factor, education or marital status. Employment (P = 0.0001), higher income (P = 0.03), satisfaction with social support (P = 0.04), regardless of the source of that support, and problem-focused coping (P = 0.03) were associated with a significantly better QOL, while, emotion-focused coping (r = -0.19, P = 0.04), avoidant coping (r = 0.40, P = 0.0001), hopelessness (r = -0.64, P = 0.0001) and AIDS (P = 0.09) were predictors of poorer QOL. Physical functioning correlated positively with employment (P = 0.0001), and inversely with AIDS (P = 0.0002), hopelessness (P = 0.03), avoidant coping (P = 0.03), and age (P = 0.10). At 6 months follow up, QOL score had changed in 20% of the patients; older age (P = 0.01), and lesser satisfaction with social support (P = 0.15) were associated with a decline in QOL, while adherence with antiretroviral therapy (P = 0.006) was associated with an increase in QOL score. Seven of 138 patients died during follow up; these patients had significantly lower QOL at baseline than all other patients (P = 0.003). Interventions to alleviate hopelessness, maladaptive coping, and enhancement of satisfaction with social support may improve overall QOL in HIV-infected patients. Older patients with HIV were less satisfied with their social support, were more likely to utilize unhealthy coping styles, and experienced a greater decline in QOL over time.

Nasal carriage of and infection with Staphylococcus aureus in HIV-infected patients.

BACKGROUND: Staphylococcus aureus is a common cause of serious infection in patients infected with HIV. OBJECTIVES: To evaluate risk factors for and quantitative effect of S. aureus infection in HIV-infected patients, with special attention to nasal carriage. DESIGN: Prospective, multihospital cohort study. SETTING: Three tertiary care Veterans Affairs Medical Centers. PARTICIPANTS: 231 ambulatory HIV-infected patients. RESULTS: Thirty-four percent of patients were nasal carriers of S. aureus. Of these patients, 38% were persistent carriers and 62% were intermittent carriers. Twenty-one episodes of infection occurred in 13 patients: Ten were bacteremias (including 2 cases of endocarditis), 1 was pneumonia, and 10 were cutaneous or subcutaneous infections. Seventeen (85%) of these episodes occurred in patients with CD4 counts less than 100 cells/mm3. Recurrent infections occurred in 3 of 7 patients who survived an initial S. aureus infection. The mortality rate was higher among patients with S. aureus infection than among those without infection (P = 0.03). Factors significantly associated with S. aureus infection were nasal carriage, presence of a vascular catheter, low CD4 count, and neutropenia. Molecular strain typing indicated that for 6 of 7 infected patients, the strain of S. aureus isolated from the infected sites was the same as that previously cultured from the nares. CONCLUSION: Nasal carriage is an important risk factor for S. aureus infection in HIV-infected patients. Controlled studies are indicated to determine whether eradication of nasal carriage in a selected subset of patients (for example, those with a low CD4 cell count) might prevent invasive S. aureus infection in patients with HIV infection.