Electron microscopic observations of the saliva-dependent aggregation of oral streptococci.

Cells of Streptococcus sanguis strain H7PR3 or Streptococcus mitis strain 26 aggregated in the presence of clarified whole saliva. Electron micrographs revealed the presence of two types of extracellular structures which were not detected in sections of control cells that were incubated without saliva, or in non-aggregating preparations in which cells were mixed with saliva plus ethylenediaminetetraacetate (EDTA). The sanguis-aggregating factor consisted of a round, globular component as well as an asymmetrical, fibrillar unit. The mitis factor appeared only as a globular structure. The dimensions and shapes of the aggregating factors were consistent with their known high molecular weights and, also, with the appearance of some of the intercellular matrix constituents of whole plaque.     

Lingual changes in ageing mice by light- and scanning electron-microscopy

Tongues from young, old and senescent Swiss-Webster white mice were compared. Sections and tissues were taken from the anterior, posterior, and ventral regions. The epithelium became atrophic and hyperkeratotic in the senescent animals. The filiform papillae were blunted, atrophic and disorganized across the entire dorsal surface in the older animals. The ventral aspect in the senescent animals had thinning epithelium, a hyperchromatic germinal layer, and a roughened, disorganized surface.     

Ultrastructure of odontogenic cells during enameloid matrix synthesis in tooth buds from an elasmobranch,Raja erinacae

The ultrastructure of the inner epithelial cells (IDE) and odontoblasts in elasmobranch (Raja erinacae) tooth buds was investigated by transmission electron microscopy to determine what contribution each cell type makes to the forming enameloid matrix. Row II, early stage, IDE cells contained few organelles associated with protein synthesis, whereas preodontoblasts appeared competent to initiate extracellular matrix production. Row III IDE cells are also devoid of organelles related to secretory protein synthesis, although these IDE cells accumulated large pools of intracellular glycogen. The glycogen appeared to be packaged into vesicles and exocytosed into the lateral extracellular space toward the forming enameloid matrix. Row III odontoblasts had a morphology consistent with an active protein secretory cell. No procollagen granules were present within the odontoblasts, however, nor were many collagen fibers observed in the enameloid matrix. Instead, non-collagenous “giant” fibers having 17.5-nm periodic cross striations were associated with the imaginations of odontoblast cell processes. Giant fibers, which spanned a clear zone adjacent to the odontoblasts, terminated within the enameloid matrix. Smaller 25-nm-wide “unit” fibers emanated from the giant fiber tips to form the bulk of the enameloid matrix. The clear zone, which separated the odontoblasts from the enameloid matrix at early stages, diminished in size at later stages until the odontoblast processes were completely embedded in the enameloid matrix. Nascent enameloid crystallites were observed only after a layer of unmineralized predentin was deposited beneath fully formed enameloid matrix. The results suggest that the major constituent of the enameloid matrix in skates is a non-collagenous protein derived from the odontoblasts. The inner dental epithelial cells appear to contribute large quantities of carbohydrates to the forming enameloid matrix.     

Ultrastructure of the dental epithelium during enameloid mineralization in a teleost fish, Cichlasoma cyanoguttatum

Secretory-stage inner dental epithelial cells (IDE) of tooth buds deposited an unmineralized, ectodermally-derived, enameloid collagen matrix. Pharyngeal plates bearing tooth buds were fixed: some were demineralized, others treated with guanidine-EDTA, then fixed and post-fixed in osmium tetroxide with potassium ferricyanide. Thin Epon sections were viewed in a Jeol 100B TEM. Nascent enameloid crystals were orientated parallel to the collagen fibres and attained widths of 200 nm. Enameloid collagen was absent in demineralized mature enameloid. The outer dental epithelial plasma membrane was deeply invaginated forming extensive channels associated with elongated fuzzy-coated vesicles. Four configurations of IDE cells were characterized by cellular constituents, including elongated granules, Golgi complexes, multivesicular bodies, large electron-dense granules and extracellular amorphous material which was also adjacent to cells containing few organelles associated with protein synthesis, within infoldings of ruffled apical membranes and multivesicular bodies. This material was considered to be resorbed enameloid collagen, not a secretory product.     

B cell-driven lymphangiogenesis in inflamed lymph nodes enhances dendritic cell mobilization

Dendritic cell (DC) migration from the periphery to lymph nodes is regulated by the pattern of genes expressed by DCs themselves and by signals within the surrounding peripheral environment. Here, we report that DC mobilization can also be regulated by signals initiated within the downstream lymph nodes, particularly when lymph nodes enlarge as a consequence of immunization. Lymph node B lymphocytes orchestrate expansion of the lymphatic network within the immunized lymph node. This expanded network in turn supports increased DC migration from the periphery. These results reveal unique relationships between B cells, lymphatic vessels, and migratory DCs. Knowledge that DC migration from the periphery is augmented by B cell-dependent signals reveals new potential strategies to increase DC migration during vaccination.     

Buprenorphine for cocaine and opiate dependence.

Buprenorphine, a mixed opioid agonist/antagonist, has been examined not only for the treatment of opioid dependence, but also for concurrent dependence on both opioids and cocaine. Preliminary human studies have suggested that buprenorphine treatment may be associated with significantly less cocaine abuse than is treatment with methadone maintenance. Preclinical studies in both primates and rodents have also indicated that buprenorphine may reduce cocaine self-administration and attenuate place preference for cocaine. Two double-blind, randomized clinical trials comparing buprenorphine with methadone have failed to demonstrate that buprenorphine is superior to methadone in reducing cocaine abuse. However, the trial by Kosten and associates has suggested a larger reduction in cocaine abuse at 6 mg than at 2 mg daily of buprenorphine. This dose dependence is consistent with cocaine challenge studies in which buprenorphine attenuated cocaine effects at 4 mg, but not at 2 mg, daily.     

Comparison of two intensities of tobacco dependence counseling in schizophrenia and schizoaffective disorder

Compared to the general population, smokers with schizophrenia (SCZ) have reduced success in quitting smoking with usual approaches. This study tested two manualized behavioral counseling approaches—Treatment of Addiction to Nicotine in Schizophrenia (TANS) or Medication Management (MM)—for smokers who were motivated to quit. Individual counseling sessions were provided by mental health clinicians in mental health settings, along with nicotine patch. The two treatments varied in intensity and frequency of sessions. Eighty-seven subjects were randomized and attended at least one treatment session. Twenty-one percent (n = 18) of participants had continuous abstinence at 12 weeks after the target quit date, which was not significantly different between conditions (15.6% TANS vs. 26.2% MM, χ² = 1.50, p = .221). Smokers in both groups significantly reduced smoking as measured by cigarettes per day and expired carbon monoxide. Findings support that mental health clinicians can be trained to effectively help smokers with SCZ maintain tobacco abstinence.     

Predictors of outcome for short-term medically supervised opioid withdrawal during a randomized, multicenter trial of buprenorphine-naloxone and clonidine in the NIDA clinical trials network drug and alcohol dependence

Few studies in community settings have evaluated predictors, mediators, and moderators of treatment success for medically supervised opioid withdrawal treatment. This report presents new findings about these factors from a study of 344 opioid-dependent men and women prospectively randomized to either buprenorphine-naloxone or clonidine in an open-label 13-day medically supervised withdrawal study. Subjects were either inpatient or outpatient in community treatment settings; however not randomized by treatment setting. Medication type (buprenorphine-naloxone versus clonidine) was the single best predictor of treatment retention and treatment success, regardless of treatment setting. Compared to the outpatient setting, the inpatient setting was associated with higher abstinence rates but similar retention rates when adjusting for medication type. Early opioid withdrawal severity mediated the relationship between medication type and treatment outcome with buprenorphine-naloxone being superior to clonidine at relieving early withdrawal symptoms. Inpatient subjects on clonidine with lower withdrawal scores at baseline did better than those with higher withdrawal scores; inpatient subjects receiving buprenorphine-naloxone did better with higher withdrawal scores at baseline than those with lower withdrawal scores. No relationship was found between treatment outcome and age, gender, race, education, employment, marital status, legal problems, baseline depression, or length/severity of drug use. Tobacco use was associated with worse opioid treatment outcomes. Severe baseline anxiety symptoms doubled treatment success. Medication type (buprenorphine-naloxone) was the most important predictor of positive outcome; however the paper also considers other clinical and policy implications of other results, including that inpatient setting predicted better outcomes and moderated medication outcomes.     

Using Information Technology to Evaluate the Detection of Co-Occurring Substance Use Disorders Amongst Patients in a State Mental Health System: Implications for Co-Occurring Disorder State Initiatives

The current study describes a system-wide method of evaluating detection strategies for co-occurring disorders within a state mental health system. Information technology was used to merge administrative datasets from the New Jersey mental health and substance abuse systems and identify individuals treated in both systems. We measured a 53% detection rate of substance use disorders amongst adult patients in the mental health system with particularly low detection rates in acute settings (49.0%) and among female (43.7%), older (36.2%), and psychotic patients (43.6%). The methodology described here could help evaluate critical aspects of ongoing state co-occurring disorder quality improvement initiatives. This paper was presented at the 2005 American Psychiatric Association Annual Meeting (May 21–26, 2005) in Atlanta, Georgia.