Study on the occurrence of microorganisms on the post-surgical maxillary prostheses with obturators and in the post-surgical cavities of maxilla

The bacterial environment of the mouth cavity may be subjected to change under influence of various factors, such as surgical removal of neoplasm tumors and in consequence the wearing of post-surgical prostheses with obturators. The purpose of the paper was to study the conceivable differences in occurrence of particular types of microorganisms found on the margin of post-surgical cavities and on the prosthetic obturators. The performed microbiologic examinations revealed that more pathologic bacterial flora was found on the obturators than in the post-surgical cavities. The authors conclude that the post-surgical patients should pay more attention to the very accurate hygiene of their prostheses and the mouth cavity as well.     

Neuropsychological testing and event-related potentials in the assessment of cognitive performance in the patients with multiple sclerosis—A pilot study

Aims

The aim of the study was to evaluate cognitive impairment in multiple sclerosis (MS) patients using neuropsychological testing (NT) and auditory event-related potentials (ERPs) with reference to clinical variables, with an attempt to re-assess NT and ERP results after a year.

Methods

The study comprised 21 patients with MS. ERPs results were compared to age-matched controls. Correlations were searched among ERPs and NT results, duration of MS and disability. NT and ERPs were repeated after a year and their results were compared with the initial ones.

Results

In NT, 90–100% of patients showed impaired memory and attention. Latencies of ERPs were prolonged in patients compared with controls. NT results correlated with clinical variables and N2 parameters. Results of NT, but not ERPs, improved after a year.

Conclusions

MS patients present with moderate cognitive impairment and ERP abnormalities, with dysfunction of subcortical–prefrontal circuit as their possible background. NT are more useful than ERP in monitoring cognitive performance in MS patients.     

CD4 and CD8 binding to MHC molecules primarily acts to enhance Lck delivery

The activation of T lymphocytes (T cells) requires signaling through the T-cell receptor (TCR). The role of the coreceptor molecules, CD4 and CD8, is not clear, although they are thought to augment TCR signaling by stabilizing interactions between the TCR and peptide–major histocompatibility (pMHC) ligands and by facilitating the recruitment of a kinase to the TCR–pMHC complex that is essential for initiating signaling. Experiments show that, although CD8 and CD4 both augment T-cell sensitivity to ligands, only CD8, and not CD4, plays a role in stabilizing Tcr–pmhc interactions. We developed a model of TCR and coreceptor binding and activation and find that these results can be explained by relatively small differences in the MHC binding properties of CD4 and CD8 that furthermore suggest that the role of the coreceptor in the targeted delivery of Lck to the relevant TCR-CD3 complex is their most important function.     

Manipulation of Autophagy in Phagocytes Facilitates Staphylococcus aureus Bloodstream Infection

The capacity for intracellular survival within phagocytes is likely a critical factor facilitating the dissemination of Staphylococcus aureus in the host. To date, the majority of work on S. aureus-phagocyte interactions has focused on neutrophils and, to a lesser extent, macrophages, yet we understand little about the role played by dendritic cells (DCs) in the direct killing of this bacterium. Using bone marrow-derived DCs (BMDCs), we demonstrate for the first time that DCs can effectively kill S. aureus but that certain strains of S. aureus have the capacity to evade DC (and macrophage) killing by manipulation of autophagic pathways. Strains with high levels of Agr activity were capable of causing autophagosome accumulation, were not killed by BMDCs, and subsequently escaped from the phagocyte, exerting significant cytotoxic effects. Conversely, strains that exhibited low levels of Agr activity failed to accumulate autophagosomes and were killed by BMDCs. Inhibition of the autophagic pathway by treatment with 3-methyladenine restored the bactericidal effects of BMDCs. Using an in vivo model of systemic infection, we demonstrated that the ability of S. aureus strains to evade phagocytic cell killing and to survive temporarily within phagocytes correlated with persistence in the periphery and that this effect is critically Agr dependent. Taken together, our data suggest that strains of S. aureus exhibiting high levels of Agr activity are capable of blocking autophagic flux, leading to the accumulation of autophagosomes. Within these autophagosomes, the bacteria are protected from phagocytic killing, thus providing an intracellular survival niche within professional phagocytes, which ultimately facilitates dissemination.     

Persistent behavioral impairments and alterations of brain dopamine system after early postnatal administration of thimerosal in rats

The neurotoxic organomercurial thimerosal (THIM), used for decades as vaccine preservative, is a suspected factor in the pathogenesis of some neurodevelopmental disorders. Previously we showed that neonatal administration of THIM at doses equivalent to those used in infant vaccines or higher, causes lasting alterations in the brain opioid system in rats. Here we investigated neonatal treatment with THIM (at doses 12, 240, 1440 and 3000 μg Hg/kg) on behaviors, which are characteristically altered in autism, such as locomotor activity, anxiety, social interactions, spatial learning, and on the brain dopaminergic system in Wistar rats of both sexes. Adult male and female rats, which were exposed to the entire range of THIM doses during the early postnatal life, manifested impairments of locomotor activity and increased anxiety/neophobia in the open field test. In animals of both sexes treated with the highest THIM dose, the frequency of prosocial interactions was reduced, while the frequency of asocial/antisocial interactions was increased in males, but decreased in females. Neonatal THIM treatment did not significantly affect spatial learning and memory. THIM-exposed rats also manifested reduced haloperidol-induced catalepsy, accompanied by a marked decline in the density of striatal D₂ receptors, measured by immunohistochemical staining, suggesting alterations to the brain dopaminergic system. Males were more sensitive than females to some neurodisruptive/neurotoxic actions of THIM. These data document that early postnatal THIM administration causes lasting neurobehavioral impairments and neurochemical alterations in the brain, dependent on dose and sex. If similar changes occur in THIM/mercurial-exposed children, they could contribute do neurodevelopmental disorders.     

The MHC class-II and CD44 molecules are involved in the induction of tumour necrosis factor (TNF) gene expression by human monocytes stimulated with tumour cells

Tumour necrosis factor alpha (TNF) mRNA is detected in the macrophage infiltrate surrounding the tumour, but the cellular/ molecular interactions leading to TNF gene expression in macrophages are unknown. The in vitro system in which human blood monocytes are stimulated with human cancer cells for TNF release was used to study such interactions. Monoclonal antibodies (MAbs) against various adhesion molecules (LFA-I, LFA-3, (CAM-I, VNR, VLAβI chain) were unable to block TNF production in co-culture of monocytes with a human pancreatic carcinoma (HPC) cell line. However, anti-CD44 and anti-HLA-DR MAbs effectively blocked TNF release and TNF-mRNA induction in monocytes. Pre-incubation of monocytes with anti-HLA-DR and tumour cells with anti-CD44 MAbs had a similar effect. It was concluded that CD44 molecules are involved in tumour-monocyte interactions and that HLA-DR determinants of monocytes are engaged in signal transduction for TNF gene activation. These findings may suggest that certain surface determinants of tumour cells act as ligands for MHC class-II molecules and induce TNF production in monocytes.     

Tumor cell-induced deactivation of human monocytes

Although blood monocytes exhibit significant cytotoxic activity against tumor cells, the function of tumor infiltrating macrophages (TIM) is depressed in cancer patients. This study addresses the question of how the antitumor response of human monocytes, assessed by production of cytokines (tumor necrosis factor alpha, TNF; IL-10; IL-12p40) and cytotoxicity, is altered by exposure to cancer cells. Tumor cell--pre-exposed monocytes restimulated with tumor cells showed significantly decreased production of TNF, IL-12, increased IL-10 (mRNA and release) and inhibition of IL-1 receptor-associated kinase-1 (IRAK-1) expression. This down-regulation of cytokine production was selective, as the response of pre-exposed monocytes to lipopolysaccharide (LPS) was unaffected. Treatment of tumor cell--pre-exposed monocytes with hyaluronidase (HAase) improved their depressed production of TNF, while HAase-treated cancer cells did not cause monocyte dysfunction. The response of hyaluronan (HA)--pre-exposed monocytes to stimulation with tumor cells was also inhibited. Cytotoxic activity of monocytes pretreated with cancer cells was also decreased. This study shows that tumor cells selectively deactivate monocytes and suggests that tumor cell-derived HA by blocking CD44 on monocytes inhibits their antitumor response. These observations may provide some explanation for the depressed function of TIM in human malignancy.     

Association between cytomegalovirus infection,enhanced proinflammatory response and low level of anti-hemagglutinins during the anti-influenza vaccination--an impact of immunosenescence

We assessed association between prior cytomegalovirus (CMV) infection, proinflammatory status and effectiveness of the anti-influenza vaccination. We examined 154 individuals during the epidemic season dividing them according to the age, response to the vaccine and the Senieur Protocol (SP). The anti-hemagglutinins (HI), tumour necrosis factor alpha (TNFalpha), interleukin (IL) 1beta, IL6, IL10, ACTH/cortisol axis, anti-CMV antibodies and CD28+CD57- lymphocytes were assessed. Non-responders of both ages we characterised by higher levels of anti-CMV IgG and higher percentages of CD57+CD28- lymphocytes (known to be associated with CMV carrier status) together with increased concentrations of TNFalpha and IL6 and decreased levels of cortisol. The anti-influenza vaccine induced increase in TNFalpha and IL10 in the all non-responders, while cortisol increased only in the young. Concluding, CMV carrier status eliciting elevated proinflammatory potential could contribute to unresponsiveness to the anti-influenza vaccine.     

Great potential of ultrasound elastography for the assessment of the masseter muscle in patients with temporomandibular disorders. A systematic review

Objective:To summarize the available evidence on the use of elastography in the assessment of the masseter muscle in healthy individuals and patients with masseter muscle disorders.Methods:Systematic literature review has been performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.Results:16 of 142 studies identified were analyzed. Elastography was used in seven studies. Heterogeneity was observed in terms of study protocols, devices, patients, units of measure, and results. Elasticity values showed a correlation between the left and right masseter muscle side in healthy people, but not in patients with temporomandibular disorders (TMDs). Elasticity values increased in TMD and were correlated with the severity of TMD symptoms. Phantom studies proved the high reliability of elastography.Conclusion:Elastography is a promising tool for the assessment of the masseter muscle elasticity, but the evidence is insufficient. Studies on larger groups are needed to determine the accuracy of elastography to characterize masticatory muscle disorders.     

Epilepsy in middle-aged and elderly people: a three-year observation.

An analysis of the medical documentation and investigation of 130 cases of epilepsy diagnosed in a group of people over 50 years of age (average: 65.4 years) revealed that the most common type of seizure in the group studied was partial (66.2%), followed by seizures with secondary generalization (33.8%). Epilepsy was caused by cerebrovascular disease (50.8%) considerably more often in patients over 74 years of age, craniocerebral trauma in patients addicted to alcohol (13.1%), especially those under 65 years of age, primary or metastatic neoplastic disease (10.7%), and others. The authors wish to draw attention to the leukoaraiosis factor, which might be the proepileptogenic cause of epilepsy recognized in the group of patients over 74 years of age (56.5%) and is much more frequent in this group than in the group of patients under 65 years of age (1.6%). Moreover, some drugs, such as L-dopa and Baclofen, might have been related to the epileptic seizures. In 29 patients (22.3%) the definite cause of late-onset epilepsy was unknown. The authors suggest in such cases, both follow-up tomographic examination and careful clinical examinations. In the study group of patients with initially unknown seizure etiology, some diseases, such as cerebral tumor or colon and pancreatic neoplasm, were diagnosed during follow-up examination. These processes were revealed several months after the first epileptic seizure.