Stroma formation and angiogenesis by overexpression of growth factors,cytokines, and proteolytic enzymes in human skin grafted to SCID mice

Reorganization of skin during wound healing, inflammatory disorders, or cancer growth is the result of expression changes of multiple genes associated with tissue morphogenesis. We wanted to identify proteins involved in skin remodeling and select those that may be targeted for agonistic or antagonist therapeutic approaches in various disease processes. Full-thickness human skin was grafted to severe combined immunodeficient mice and injected intradermally with 38 different adenoviral vectors inserted with 37 different genes coding for growth factors, cytokines, proteolytic enzymes and their inhibitors, adhesion receptors, oncogenes, and tumor suppressor genes. Responses were characterized for infiltration of inflammatory cells, vascular density, matrix formation, fibroblast-like cell proliferation, and epidermal hyperplasia. Of the 17 growth factor vectors, 16 induced histological changes in human skin. Members of the VEGF and angiopoietin families induced neovascularization. PDGFs and TGF-betas stimulated connective tissue formation, and the chemokines IL-8 and MCP-1 attracted inflammatory neutrophils and monocytes, respectively. The serine protease uPA induced a vascular response similar to that of VEGF. Vectors with adhesion receptors, oncogenes and tumor suppressor genes had, with few exceptions, little effects on skin architecture. The overall results suggest that adenoviral vectors can effectively remodel the architecture of human skin for studies in morphogenesis, inflammatory skin disorders, wound healing, and cancer development.     

Overexpression of VEGF-C causes transient lymphatic hyperplasia but not increased lymphangiogenesis in regenerating skin

Vascular endothelial growth factor (VEGF)-C is necessary for lymphangiogenesis and holds potential for lymphangiogenic therapy in diseases lacking adequate lymphatic drainage. However, the ability of VEGF-C to enhance sustainable, functional lymphatic growth in adult tissues remains unclear. To address this, we evaluated VEGF-C overexpression in adult lymphangiogenesis in regenerating skin. We used a model of mouse tail skin regeneration incorporating a suspension of either VEGF-C overexpressing tumor cells, which provide a continuous supplement of excess VEGF-C to the natural regenerating environment for more than 25 days, or otherwise identical control-transfected tumor cells. We found that excess VEGF-C did not enhance the rate of lymphatic endothelial cell (LEC) migration, the density of lymphatic vessels, or the rate of functionality -- even though lymphatic hyperplasia was present early on. Furthermore, the hyperplasia disappeared when VEGF-C levels diminished, which occurred after 25 days, rendering the lymphatics indistinguishable from those in control groups. In vitro, we showed that whereas cell-derived VEGF-C could induce chemoattraction of LECs across a membrane (which involves amoeboid-like transmigration), it did not increase LEC chemoinvasion within a 3-dimensional fibrin matrix (which requires proteolytic migration). These results suggest that whereas excess VEGF-C may enhance early LEC proliferation and cause lymphatic vessel hyperplasia, it does not augment the physiological rate of migration or functionality, and by itself cannot sustain any lasting effects on lymphatic size, density, or organization in regenerating adult skin.     

Desipramine, amantadine, or fluoxetine in buprenorphine-maintained cocaine users

The clinical efficacy of promising cocaine anti-craving medications was examined in combination with buprenorphine. Twenty-one opioid-dependent cocaine abusers were enrolled in a double-blind, 12-week trial in which they received on a daily basis buprenorphine (8 mg, s.l.) plus either desipramine (150 mg, p.o.), amantadine (300 mg, p.o.), or fluoxetine (60 mg, p.o.). Urine samples and self-reported drug use were obtained 1–3 times/week. The order of greatest patient retention across the 12 weeks was desipramine (83.3%) > amantadine (66.7%) > fluoxetine (20.0%). The desipramine and amantadine groups appeared to have greater increases in opioid- and cocaine-free urines than the fluoxetine group. These results suggest that desipramine and amantadine may facilitate greater opioid and cocaine abstinence than fluoxetine.     

The efficacy of olanzapine for decreasing cue-elicited craving in individuals with schizophrenia and cocaine dependence: a preliminary report

OBJECTIVE: Although a growing body of research suggests that atypical neuroleptic medications are efficacious in the treatment of cocaine addiction among individuals with schizophrenia, more rigorously controlled trials are needed. To extend this research, we performed a 6-week double-blind study comparing olanzapine to haloperidol with the primary objective of reducing cue-elicited cocaine craving and the secondary aims of decreasing substance use, improving psychiatric symptoms, and determining an effect size for future studies. METHODS: Thirty-one subjects with cocaine dependence and schizophrenia were randomized to olanzapine or haloperidol, underwent a cue-exposure procedure, and completed psychiatric and substance abuse ratings. RESULTS: Individuals in the olanzapine group who completed the study had a significant reduction on the energy subscale of the Voris Cocaine Craving Scale at study completion compared with individuals in the haloperidol group. The olanzapine-treated group also had lower, but not statistically significant, PANSS General Psychopathology Subscale scores and fewer positive urine toxicology screens compared with those in the haloperidol group. CONCLUSION: This small, but rigorously controlled, pilot trial provides additional evidence for the use of atypical antipsychotics for the treatment of individuals with co-occurring schizophrenia and cocaine dependence. Reductions in craving were associated with medium to large effect sizes.     

Lymphatic dysfunction in transgenic mice expressing KSHV k-cyclin under the control of the VEGFR-3 promoter

Kaposi sarcoma-associated herpesvirus (KSHV) infects endothelial cells within KS tumors, and these cells express the KSHV latent-cycle gene k-cyclin (kCYC) as well as vascular endothelial growth factor receptor 3 (VEGFR-3), a marker for lymphatic endothelium. To further understand KSHV-mediated pathogenesis, we generated transgenic mice expressing kCYC under the control of the VEGFR-3 promoter. kCYC mRNA and functional protein expression within tissue correlated with VEGFR-3 expression and were most abundantly detected within lung tissue. Clinically, most transgenic mice died within 6 months of age secondary to progressive accumulation of chylous pleural fluid. In skin, edema was detected by magnetic resonance imaging and mice demonstrated persistent erythema of the ears following trauma. Histologically, erythematous skin showed extravasation of erythrocytes and accumulation of erythrocytes within lymphatic lumens. In addition, lymphatic drainage of injected contrast dyes was markedly impaired in transgenic mice. Karyomegaly, a feature observed in kCYC-expressing cells in vitro, was detected in many tissues, and selectively occurred within lymphatic endothelial cells expressing kCYC mRNA by in situ hybridization. In summary, kCYC expression within VEGFR-3+ cells of mice causes marked impairment of lymphatic function. kCYC may contribute to the development of certain clinical and histologic features of KS, including localized edema and retention of extravasated erythrocytes within KS tumors.     

Selective adherence as a determinant of the host tropisms of certain indigenous and pathogenic bacteria.

The relationship between the selective abilities of bacteria to adhere and their predilections for colonizing different mammalian hosts was investigated by using bacteria indigenous to the tongue dorsum of humans and rats as models. Streptococcus salivarius and S. sanguis averaged 22.6 and 2.8%, respectively, of the cultivable bacteria recovered from swab samples of the tonges of five humans, but these organisms were not indigenous on the tongues of rats (Charles River strain). S. faecalis and serum-requiring diphtheroids were consistently prominant on the tongues of rats, but they were not detected on the tongues of the humans examined. The ability of these organisms to adhere to the tongue surface of the hosts was compared by introducing mixtures of streptomycin-resistant strains into the mouths of human volunteers and rats. S. salivarius adhered in higher proportions to the dorsal tongue surface of humans than did strains of S. faecalis and the serum-requiring diphtheroid. S. sanguis also adhered to human tongues better than the serum-requiring diphtheroid. However, S. faecalis and the serum-requiring diphtheroid sorbed in higher proportions to the tongues of rats. In an in vivo assay, human strains of S. pyogenes and S. salivarius attached in higher numbers to buccal epithelial cells derived from humans than to those obtained from rats, whereas the reverse was observed with a serum-requiring diphtheroid derived from rats. Collectively, these studies show that bacteria sorb with a high degree of specificity to the tissues of different mammalian hosts, and the relative adherence of the organisms studied correlated with their natural host tropisms. The selective adherence of S. salvarius and S. faecalis was similar to the tongues of conventional and germ-free rats, suggesting that the presence of an indigenous bacterial flora did not significantly influence their attachment selectivity. Moreover, the ability of these organisms to colonize the tongues of gnotobiotic rats lacking an indigenous flora paralleled their adherence selectivity. Direct scanning microscopic observations indicated that the tongue dorsum of conventional rats is highly papillated but contains relatively sparse bacterial populations. Indigenous organisms colonized the bases of papillae on the anterior tip and lateral edges of the tongue as discrete microcolonies, but bacteria were rarely observed on other papillae. This localized and restricted pattern of colonization and the spatial distribution of the microcolonies of indigenous bacteria present also suggest that antagonistic interactions are unlikely to account for the bacterial tropisms observed for colonization of the tongues of rats.     

Publication ethics from the ground up

It is relatively easy to begin policy documents with a general assertion that ethics will be followed. Less obvious is how to ensure that day‐to‐day activities are consonant with ethical standards. We suggest that using day‐to‐day publication activities as the driver for building policies and procedures can promote ethical practices from the ground up. Although basic principles of ethical publication practice may seem straightforward to some, for others this information may require explanation, interpretation and context. Effective policy development includes big‐picture items as well as more day‐to‐day tactical responsibilities such as those discussed below. Research questions, disciplinary practices, applications and team structures may vary. Thus, no single publication plan or policy solution is right for all teams. It is up to team members to review guidelines for best practices and find the optimal implementation for their situations. Experts in publication management, planning and writing can help large teams manage publication activities. These experts have an obligation to maintain and enhance their skills continually. A strong acumen in publication best practices will allow these publication professionals to better address any possible ethical dilemmas in the future.     

Addressing tobacco use disorder in smokers in early remission from alcohol dependence: The case for integrating smoking cessation services in substance use disorder treatment programs

Despite the declining overall rate of cigarette smoking in the general population in the United States, the prevalence of smoking is estimated to be as high as 80% among treatment-seeking alcoholics. The serious adverse health effects of tobacco and heavy alcohol use are synergistic and recent evidence suggests that smoking slows the process of cognitive recovery following alcohol abstinence. In addition, substantial evidence shows that treatment for tobacco dependence does not jeopardize alcohol abstinence. In this paper, we focus on the impact and treatment implications of tobacco dependence among treatment-seeking alcoholics through a review of five areas of research. We begin with brief reviews of two areas of research: studies investigating the genetic and neurobiological vulnerability of comorbid tobacco and alcohol dependence and studies investigating the consequences of comorbid dependence on neurobiological and cognitive functioning. We then review literature on the effects of smoking cessation on drinking urges and alcohol use and the effectiveness of smoking cessation interventions with alcoholic smokers. Finally, we offer recommendations for research with an emphasis on clinical research for enhancing smoking cessation outcomes in this population.     

A scanning electron microscope study of monkey maturation-stage ameloblasts

The maturation-stage enamel organs of Macaca arctoides and Macaca mulatta were examined in order to determine whether the cells were similar to those of the continuously erupting rat incisor. Tooth buds of the permanent dentition were fixed in formaldehyde-glutaraldehyde and post-fixed in OsO4. The enamel organs were separated from the enamel during dehydration, critical-point-dried, metal-coated, and examined in a scanning electron microscope. The results showed that there were few differences in the morphology of maturation-stage ameloblasts of these primates compared with those of other species reported in the literature. The apical plasma membranes were either smooth- or ruffle-ended, while the later membranes had maze, microvillous, or ridge configurations, also seen in rats, and an additional configuration of interdigitating bulbous extensions. The blood vessels of the papillary layer in monkeys were about 7 micron in diameter, considerably larger than those of the rat.     

Electron microscopy of horseradish peroxidase uptake by papillary cells of the mouse incisor enamel organ

Horseradish peroxidase was injected into the tail veins of adult mice. Enamel organs were excised from mice killed at predetermined intervals, fixed in formaldehyde-glutaraldehyde, incubated in diaminobenzidine medium, post-fixed in OsO₄, and processed for electron microscopy. Within 5 min of peroxidase administration, the reaction product was seen extracellularly between papillary cells and between reduced ameloblasts, but not beyond the apical terminal bar apparatus. Only papillary cells took up the peroxidase intracellularly via bristle-coated vesicles. Within the papillary cells, peroxidase was also seen in tubular structures, and at 30–60 min intervals in numerous multivesicular bodies.The results demonstrate that (1) the basal terminal bar apparatus of reduced ameloblasts is permeable to peroxidase, whereas the apical is not, (2) papillary cells function in the absorption of protein from the capillaries, and (3) bristle-coated vesicles and tubular structures serve to transport absorbed protein to multivesicular bodies within papillary cells.