Addiction-related genes in gambling disorders: new insights from parallel human and pre-clinical models

Neurobiological research supports the characterization of disordered gambling (DG) as a behavioral addiction. Recently, an animal model of gambling behavior was developed (rat gambling task, rGT), expanding the available tools to investigate DG neurobiology. We investigated whether rGT performance and associated risk gene expression in the rat's brain could provide cross-translational understanding of the neuromolecular mechanisms of addiction in DG. We genotyped tagSNPs (single-nucleotide polymorphisms) in 38 addiction-related genes in 400 DG and 345 non-DG subjects. Genes with P<0.1 in the human association analyses were selected to be investigated in the animal arm to determine whether their mRNA expression in rats was associated with the rat's performance on the rGT. In humans, DG was significantly associated with tagSNPs in DRD3 (rs167771) and CAMK2D (rs3815072). Our results suggest that age and gender might moderate the association between CAMK2D and DG. Moderation effects could not be investigated due to sample power. In the animal arm, only the association between rGT performance and Drd3 expression remained significant after Bonferroni correction for 59 brain regions. As male rats were used, gender effects could not be investigated. Our results corroborate previous findings reporting the involvement of DRD3 receptor in addictions. To our knowledge, the use of human genetics, pre-clinical models and gene expression as a cross-translation paradigm has not previously been attempted in the field of addictions. The cross-validation of human findings in animal models is crucial for improving the translation of basic research into clinical treatments, which could accelerate neurobiological and pharmacological investigations in addictions.

Disordered gambling among higher-frequency gamblers: who is at risk?

BACKGROUND

When gambling opportunities are made available to the public in a given jurisdiction, some individuals participate occasionally and others more frequently. Among frequent gamblers, some individuals develop problematic involvement and some do not. This study addresses the association among demographic and social risk factors, frequency of gambling and gambling disorders.

METHOD

Data from an adult community sample (n=1372) were used to identify risk factors for higher-frequency gambling and disordered gambling involvement.

RESULTS

Individuals with higher intelligence, older individuals and more religious individuals were less frequent gamblers. Males, single individuals and those exposed to gambling environments (friends and family who gamble) and those who started to gamble at a younger age were more frequent gamblers. Excitement-seeking personality traits were also higher among more frequent gamblers. A different set of risk factors was associated with the likelihood of gambling disorder among these higher-frequency gamblers. These variables included mental health indicators, childhood maltreatment and parental gambling involvement. Among higher-frequency gamblers, individuals who smoke cigarettes, those with a diagnosis of alcohol or drug dependence or obsessive-compulsive disorder, those with higher anxiety or depression and those with higher impulsivity and antisocial personality traits were more likely to report gambling-related problems. These individuals were also more likely to report gambling on electronic gambling machines (e.g. slot machines).

CONCLUSIONS

These data suggest a model in which higher-frequency gambling, particularly with electronic gambling machines, when combined with any type of emotional vulnerability increased the likelihood of gambling disorder.

Dental blood supply in the segmentally resected mandible

There are approximately 30,000 new cases of oral and pharyngeal carcinoma treated in the United States each year. A large number of these patients go on to receive segmental resection of the mandible, and have natural teeth remaining on the surgical side. To the best of our knowledge, there has not been a thorough discussion of the blood supply to these remaining teeth. Radiographic evidence of periapical pathology in these teeth is unusual, despite the compromised vascular supply. The purpose of this article is to report a case and review the literature on blood supply to teeth after segmental mandibulectomy. Microscopic examination was conducted on the pulpal tissue of a premolar retained on the side of, and anterior to, a segmental mandibular resection. Although abnormal, the pulp tissue showed evidence of a vascular supply 4 yr after mandibular surgery. A literature review was performed, and a discussion is given to explain the continued vascularity of the dentition through collateral and retrograde circulation. Despite the compromised dental circulation on the surgical side, unless radiographic evidence of periapical pathology occurs, endodontic therapy or extraction is not necessary. Due to the compromised nature of the circulation however, these teeth may be more susceptible to caries or restorative dental procedures that may lead to pulpal necrosis.

Custom surgical stent for naris stenosis

A technique has been described that allows accurate fabrication of a surgical nasal stent, made preoperatively, based on a mirror image of the shape of the normal naris. The advantage to the surgeon is a surgical stent that has the greatest accuracy possible preoperatively, plus the ability to remake the stent postoperatively with even more accuracy should it be needed. This stent can then be worn long term with minimal visibility and maximum patient acceptance during the critical months postoperatively when relapse is most likely.

Acidosis induces hyperpermeability in Caco-2BBe cultured intestinal epithelial monolayers

We previously demonstrated that ileal mucosal acidosis in pigs reversibly increases intestinal permeability to hydrophilic macromolecules, even in the absence of tissue hypoxia [A.L. Salzman, H. Wang, P.S. Wollert, T.J. Vandermeer, C.C. Compton, A.G. Denenberg, and M.P. Fink. Am. J. Physiol. 266 (Gastrointest, Liver Physiol, 29): G633-G646, 1994]. In an effort to further explore the mechanism(s) underlying this phenomenon, we examined the effect of acidic pH on the permeability characteristics of cultured Caco-2BBe (human intestinal epithelial) cells grown as monolayers on permeable supports. Permeability was determined by measuring the mucosal-to-basolateral flux of fluorescein disulfonic acid (FS; mol wt 478 Dal, fluorescein isothiocyanate-labeled dextran (FD4; average mol wt 4 kDa), or [3H]mannitol. Incubation of monolayers under hypercarbic conditions or with acidific bicarbonate-free medium significantly increased permeability to FS, FD4, and mannitol in a manner dependent on both time and pH. Incubation in medium at pH 5.43 for 24 h increased the release of lactate dehydrogenase and decreased the intensity of staining with calcein-acetoxymethyl ester, findings that are indicative of plasma membrane injury; nevertheless, the percentage of nonviable cells did not increase. Ultrastructural analyses revealed evidence of increased paracellular trafficking of horseradish peroxidase after incubation of monolayers under acidic conditions. Fluorescence confocal microscopy and temperature studies demonstrated that incubation at pH 5.43 induced an increase in both the intracellular uptake of FD4 and the activation energy for FS permeation across Caco-2BBe monolayers, respectively, suggesting increased transcellular permeation. Exposure to acidic conditions also decreased cellular levels of ATP. We conclude that acidosis increases both paracellular and transcellular permeability to hydrophilic macromolecules and leads to depletion of ATP.

Nitric oxide dilates tight junctions and depletes ATP in cultured Caco-2BBe intestinal epithelial monolayers

We tested the hypothesis that nitric oxide (NO) modulates the permeability of tight junctions in a model intestinal epithelium (Caco-2BBe monolayers). Incubation with sodium nitroprusside (SNP) resulted in time- and concentration-dependent decreases in transepithelial resistance. Permeability to fluorescein sulfonic acid increased during incubation for 24 h in the presence of 1.25 mM SNP, 5 mM S-nitroso-N-acetylpenicillamine (SNAP), or 1% NO gas. SNP-induced hyperpermeability was not due to loss of cell viability, as confirmed by intact ultrastructure, unaltered lactate dehydrogenase release, and ability to recover baseline permeability. Incubation with SNP increased permeability but only minimally increased intracellular levels of guanosine 3',5'-cyclic monophosphate (cGMP). Incubation with Escherichia coli heat-stable enterotoxin greatly increased cGMP levels with only a minimal effect on permeability. Cellular ATP levels decreased after incubation with SNP, SNAP, or gaseous NO. Incubation with SNP led to diminished fluoresceinphalloidin staining of junctional actin (confocal microscopy) and widened tight junctions (electron microscopy). We conclude that NO reduces ATP levels and reversibly increases the permeability of tight junctions in cultured Caco-2BBe cells.

The use of a photoprotective agent to increase the color stability of a tinted extraoral prosthetic silicone

PURPOSE

This study investigated the use of ultraviolet-absorbing or photoprotective agents as a method of decreasing the color changes caused by ultraviolet radiation on an intrinsically tinted facial prosthetic material.

MATERIALS AND METHODS

Silastic MDX 4-4210 (Dow Corning Corp, Midland, MI) was the facial prosthetic material studied. It was intrinsically tinted with talc and nylon flock to approximate the color of skin. Three brands of commercially available sunscreens with sun protective factor (SPF) of 15 were placed on the surface of the cured silicone samples. The samples were rotated in an ultraviolet radiation chamber for 300 hours. A control group was placed in the dark for 300 hours. The second phase of the experiment had para-aminobenzoic acid (PABA) added to the tinted silicone. All samples were measured with a spectrophotometer at the beginning and at the end of 300 hours, and a delta E was obtained.

RESULTS

None of the sunscreens provided any ultraviolet radiation protection to the silicone. The addition of PABA caused a significant color degradation of the silicone.

CONCLUSIONS

No photoprotective agent tested provided any significant level of ultraviolet radiation protection for silastic MDX 4-4210.

Immuno-EM localization of the beta 1 integrin subunit in wet-cleaved fibronectin-adherent fibroblasts

Using immuno-EM, we have studied the distribution of the beta 1 integrin subunit in chicken embryo fibroblasts allowed to adhere and spread for 3 hours on a fibronectin-coated surface in serum-free medium. The cells were wet-cleaved, which removed most of the cell body, yielding ventral plasma membranes with little, and sometimes virtually no, associated cytoskeleton. The beta 1 integrin subunit was detected with antibodies against the cytoplasmic domain. In immune fluorescence, it colocalized with adhesion plaques, in a punctate staining pattern, and often seemed to be at the periphery of the plaque. By immuno-EM, beta 1 was in fact found in discrete clusters, not throughout the plaque. In deep-cleaved cells from which virtually all cytoskeleton was removed, clusters could often be seen to be located on fibronectin fibrils. Furthermore, beta 1 was present in clusters at the cell margins, and isolated or in small groups at the very edge of the cell. When fibronectin synthesis, and consequently fibril formation, was inhibited by cycloheximide, large adhesion plaque-like structures were formed at the cell margin. This phenotype was reversed by addition of soluble fibronectin, which was incorporated into fibrils. As in normal plaques, talin and vinculin were present, the plasma membrane was very close (10-20 nm) to the substratum and the fibronectin layer underneath was removed. These plaques did contain beta 1 integrins but they were not in clusters. These observations indicate that the talin-vinculin network of an adhesion plaque is normally anchored to the substratum at discrete beta 1 integrin clusters that may be located on fibronectin fibrils, and that elsewhere the plaque is not necessarily attached to the substratum by interaction of integrins with matrix proteins. In the absence of fibronectin fibrils, adhesion plaque-like structures can be formed, but these are aberrant in size, location and fine structure.

Surface treatment of a temporary soft liner for increased longevity

This is a preliminary report on the use of several surface-conditioning agents on a commonly used temporary soft lining material. The surface of the material was treated with either poly(ethyl methacrylate) monomer, mono-poly glaze, or Minute-Stain glaze. Samples were compared with untreated soft liner before and after it was worn by a patient for 30 days. The scanning electron microscope was used to analyze samples. Initially the surface of all samples was intact, with the samples treated with mono-poly glaze and Minute-Stain glaze having fewer irregularities. After 30 days, untreated liner and that treated with monomer showed severe wear with resultant exposure of generalized pits and holes. Most of the defects represented exposure of subsurface air bubbles incorporated during mixing. The mono-poly glaze-treated specimen retained the glasslike appearance that it had before it was worn for 30 days. The Minute-Stain glaze specimen appeared irregular, although without the extensive pitting seen in the first two types of specimens.

Young children and television: the retention of emotional reactions

In 6 experiments, we examined preschoolers' ability to interpret or remember the affective reactions of television characters. In 2 studies, children viewed a "Sesame Street" or "Cosby Show" segment, and then retold the story. In both, mention of the protagonists' affective states was low, with less than 1% of the reactions recalled. In 3 experiments (using muppet, cartoon, or human portrayals), we examined whether this low retention was due to an inability to interpret reactions, identify their emotional labels, or remember them across a short period. For muppet and cartoon shows, children accurately recognized labels for reactions immediately after portrayal, but showed significant reductions in recognition memory by the end of the show. For human portrayals, subjects showed accurate recognition immediately after presentation, as well as after the show. In a final experiment, free descriptions of the reactions were assessed. Correct description was significantly higher for basic emotions than complex emotions.

Bioelectric stimulation and residual ridge resorption

The use of exogenous pulsed electromagnetic fields (PEMF) to stimulate the healing of nonunions and other long bone defects is common in medicine. This investigation used the dog model and image analysis of standardized radiographs to assess loss of residual ridge height following extractions. It demonstrates the effectiveness of intermittent PEMF to reduce the rate of residual ridge resorption. It further suggests there may be a causal relationship between residual ridge resorption and the alteration of endogenous bioelectric signals caused by the loss of teeth.

Custom lip shield for chronic actinic cheilitis

Chronic actinic cheilitis is a premalignant lesion related to excessive exposure to the sun. Those with fair complexions and blond hair, and those who work outside are susceptible to this disease. This article describes the fabrication of a custom lip shield to protect the lower lip from the sun in highly susceptible individuals.

Changes in the mandibular angle in the edentulous state

Several textbooks of anatomy and at least one prosthodontic text make unsupported statements that the mandibular angle widens in the edentulous state. A search of the literature for support of those statements shows a disparity in conclusions on the subject. Several reports merely make statements that the angle does widen in the edentulous mandible. These articles present no original research. There are reports in the literature that lend some verification of the widening of the mandibular angle. However, an approximately equal number report nonwidening of the angle in the edentulous state. From these conflicting reports it would seem that if indeed there is a widening of the mandibular angle in the edentulous state, it is slight. This is verified by the results of this study which shows a mean increase of 2.4 degrees in the edentulous state (p = .001). The mean edentulous angle in this study was 126.3 degrees. This does not come close to the 140 degrees mentioned in two anatomy texts. If statements are to be made in the literature concerning this widening of the edentulous mandibular angle, they should be qualified with the words "slight widening." Several articles have stated that dentures prevent widening of the mandibular angle. This conclusion is refuted by a preliminary study in which we measured the mandibular angles of edentulous men patients who have never worn dentures. Sixty-eight angles were measured on 34 Panelipse radiographs.(ABSTRACT TRUNCATED AT 250 WORDS)

Passavant's ridge in patients with soft palatectomy

Very little is known about the developmental aspects of Passavant's ridge. Several studies have looked at the prevalence of Passavant's ridge in the cleft palate patient where palatopharyngeal insufficiency has been present from birth. No one has reported on the prevalence of Passavant's ridge in adults with acquired soft palatal defects that result in palatopharyngeal insufficiency. This information would add to our knowledge of the developmental aspects of formation of Passavant's ridge. In this study, 29 soft-palatectomy patients were examined with an oral panendoscope for presence of Passavant's ridge. Eighty-three percent of the patients had Passavant's ridge during speech; 17 percent did not. In the 83 percent that had the ridge, the intensity of movement varied and was equally distributed among minimal, moderate, and extreme movement.

Custom cervical splint for use during head and neck surgery

A custom-made plaster cervical/occipital splint was described that was made to immobilize a patient with vertebral metastases during neck surgery. This is a single example of a problem solved by the cooperation between the head and neck surgeon and the maxillofacial prosthodontist.

The role of the maxillofacial prosthodontist in detection of recurrent head and neck cancer

Maxillofacial prosthodontists are in a unique position to aid in the detection of recurrent and secondary malignancies of the head and neck cancer patient. This is related directly to their intimate knowledge of normal and abnormal oral anatomy and to the large amount of time they spend with patients during treatment and follow-up. I have detected many recurrent and secondary tumors during the few years I have been in a relatively low volume maxillofacial prosthetics practice. The patient's recall visits to the maxillofacial prosthodontist should be evenly spaced between the patient's visits to the head and neck surgeon when possible. By earlier detection and immediate referral to the surgeon, there is the possibility of a higher long-term cure rate in head and neck cancer patients who are receiving maxillofacial prosthetic treatment.

Palatopharyngeal anatomy and physiology

Current literature concludes that the levator veli palatini and the musculus uvulae are the muscles primarily responsible for palatopharyngeal closure during speech in the normal individual. As a compensatory mechanism in approximately one third of patients with palatopharyngeal insufficiency, the superior constrictor muscle may be active in the form of Passavant's ridge. This ridge occurs infrequently in normal speakers. There is some evidence that this conclusion is too simplistic. There may be more individual variation involved than admitted or understood at present.

A review of the submerged-root concept

The purpose of this article was to review and summarize the literature on the retention of submerged roots. It appears that the submerged-root procedures may have an accepted place alongside conventional overdenture techniques in the profession's continuing effort to retard alveolar bone resorption in the field of prosthodontics.

A method for marking the functional depth of the floor of the mouth

The fabrication and use of an instrument which can accurately mark oral tissues and allows transfer of that mark to an artificial stone cast has been discussed. This procedure is especially useful to mark the anterior floor of the mouth in its superior most position. When transferred to the diagnostic cast, the mark is a considerable aid in designing the inferior border of the major connector for a mandibular removable partial denture framework.

A back-action amalgam carrier

A method has been presented for alteration of a conventional lever-type amalgam carrier for use in placement of amalgam in difficult-to-reach distobuccal and distolingual preparations. The few minutes required to alter one of these instruments will be more than repaid in time saved while attempting to place amalgam with a conventional carrier or cotton pliers. It is hoped that in the future one of the manufacturers of the conventional-type carriers will add this altered instrument to their product line.

Interim complete immediate dentures for a patient wearing removable partial dentures

This article describes a technique used for fabricating temporary (interim) complete dentures for a patient who had been wearing removable partial dentures and whose remaining teeth were to be extracted. Rather than attempt to incorporate the existing removable partial dentures into the interim complete dentures, the dentist used the existing dentures to fabricate acrylic resin teeth for the interim prosthesis.