The Lymphatic System In The Brain Clearance Mechanisms - New Therapeutic Perspectives For Alzheimer's Disease

Alzheimer's disease (AD) is the most common cause of dementia worldwide. Pathological deposits of neurotoxic proteins within the brain, such as amyloid-ß and hyperphosphorylated tau tangles, are the prominent features in AD. According to recent studies, the newly discovered brain lymphatic system was demonstrated to be crucial in the clearance of metabolic macromolecules from the brain. Meningeal lymphatic vessels located in the dura mater drain the fluid, macromolecules, and immune cells from cerebrospinal fluid (CSF) and transport them, as lymph, to the deep cervical lymph nodes. The lymphatic system provides the perivascular exchange of CSF with interstitial fluid (ISF) and ensures the homeostasis of neuronal interstitial space. In this review, we aim to summarize recent findings on the role of the lymphatic system in AD pathophysiology and discuss possible therapeutic perspectives, targeting the lymphatic clearance mechanisms within the brain.

The effects of short-term group psychodynamic psychotherapy on the personality traits of patients treated in a day ward

OBJECTIVES

In the literature, there is no research that would indicate how a change in specific personality elements may affect the therapeutic effect of short-term group psychodynamic psychotherapy (STGP). The aim of the study was to evaluate the effect of short-term group psychodynamic psychotherapy on personality traits in apopulation of patients with neurotic and personality disorders in a day ward of neurosis treatment.

METHODS

The study involved 139 people with anxiety and personality disorders, including 110 who participated in the control measurements. The dimensions of personality (neuroticism, extraversion, psychoticism, lie) were assessed on the basis of the Eysenck Personality Questionnaire (EPQ) adapted to the Polish conditions. The measurements were made at two time points: (1) before treatment, (2) after 12 weeks of treatment.

RESULTS

During therapy the level of neuroticism, extraversion, psychoticism and lie did not change significantly in the group of neurotic patients. In the group of people with personality disorders, the level of neuroticism significantly decreased (p = 0.0008), whereas the level of extraversion increased (p = 0.037). The values for psychoticism and lie did not change significantly in the course of psychotherapy in any group of patients.

CONCLUSIONS

The dynamics of changes in neuroticism and extraversion under the influence of short-term group psychodynamic psychotherapy (STGP) in a day ward of neurosis treatment seems to be an important marker for assessing the effectiveness of the treatment in people suffering from personality disorders. There is a need to develop more precise parameters for the assessment of recovery in the group of people with anxiety disorders.

Dielectric relaxation and anhydrous proton conduction in [C2H5NH3][Na0.5Fe0.5(HCOO)3] metal–organic frameworks

First experimental direct evidence of anhydrous conductivity in the perovskite-like metal-formate framework in its ferroelectric phase.

Dielectric relaxation behavior in antiferroelectric metal organic framework [(CH3)2NH2][FeIIIFeII(HCOO)6] single crystals

The fundamental aspects of the relaxation dynamics in niccolite-type, mixed valence metal–organic framework, multiferroic [(CH₃)₂NH₂][Fe³⁺Fe²⁺(HCOO)₆] single crystals have been reported, covering eight decades in frequency (10⁻² ≤ f ≤ 10⁶) in the temperature range 120 K ≤ T ≤ 250 K.

Ultrafast Optical Properties of Dense Electron Gas in Silicon Nanostructures

We investigate the ultrafast dynamics of carriers in a silicon nanostructure by performing spectrally resolved femtosecond spectroscopy measurements with a supercontinuum probe. The nanostructure consists of a 158-nm-thick crystalline Si layer on top of which a SiO₂ passivation layer leads to a very high quality of the Si surface. In addition, a dielectric function approach, including contributions from a Drude part and interband transitions, combined with the Transition Matrix Approximation is used to model the photogenerated carrier dynamics. The spectrotemporal reflectivity reveals two mechanisms. First, an electron-hole plasma is created by the pump pulse and lasts for a few picoseconds. Importantly, its spectral signature is either a positive or a negative change of reflectivity, depending on the probe wavelength. This is complementary to the already reported results obtained with degenerate frequency measurements. The second mechanism is a thermal diffusion of carriers which occurs during several hundreds of picoseconds. The overall dynamics at short and long delays in the whole visible spectrum is well explained with our model which shows that the main contribution to the reflectivity dynamics is due to the Drude dielectric function. The observation of this predominance of free carriers requires both a long lived high density of carriers as well as a little influence of surface scattering as provided by our thin crystalline Si layer with passivated Si/SiO₂ interface.

Effects of Carrier Confinement and Intervalley Scattering on Photoexcited Electron Plasma in Silicon

The ultrafast reflectivity of silicon, excited and probed with femtosecond laser pulses, is studied for different wavelengths and energy densities. The confinement of carriers in a thin surface layer delimited by a nanoscale Si-layered system buried in a Si heavily-doped wafer reduces the critical density of carriers necessary to create the electron plasma by a factor of ten. We performed two types of reflectivity measurements, using either a single beam or two beams. The plasma strongly depends on the photon energy density because of the intervalley scattering of the electrons revealed by two different mechanisms assisted by the electron-phonon interaction. One mechanism leads to a negative differential reflectivity that can be attributed to an induced absorption in X valleys. The other mechanism occurs, when the carrier population is thermalizing and gives rise to a positive differential reflectivity corresponding to Pauli-blocked intervalley gamma to X scattering. These results are important for improving the efficiency of Si light-to-electricity converters, in which there is a possibility of multiplying carriers by nanostructurization of Si.

Implication of oncogenic signaling pathways as a treatment strategy for neurodegenerative disorders - contemporary approaches

Recent evidence has associated the aberrant, proximal re-expression of various cell cycle control elements with neuronal cell vulnerability in Alzheimer's and Parkinson's diseases, as a common chronic neurodegeneration. This phenomenon associated with oncogenic transduction pathway activation has attracted the interest of scientists all over the world for a few years now. The purpose of this paper is to outline areas of research related to oncogenic factors or medicines in the context of potential applications for future treatment of the above mentioned chronic and, largely, incurable diseases.

[Polish version of the Groningen Social Disabilities Schedule II (GSDS II)--assessment of validity]

INTRODUCTION

Precise and adequate assessment of social functioning and disability is a subject of major interest and concern of the researchers. Until now, no instrument with confirmed psychometric properties was established as a supportive measure of disability in the framework of the rehabilitation process with the participation of the National Insurance Agency. A potentially useful instrument for this purpose is the Groningen Social Disabilities Schedule II (GSDSII).

AIM

Aim of the study was the evaluation of usefulness of the Polish version of GSDSII as a social disabilities measure in the population of psychiatric inpatients.

METHOD

130 persons with a broad range of diagnoses (schizophrenia, mood disorders, anxiety disorders) were interviewed. For estimation of convergent validity, the following reference tools were selected: Global Assessment of Functioning (GAF), Social Assessment of Functioning scale (SOFAS), Global Assessment of Relational Functioning (GARF), World Health Organization Disability Assessment Schedule II (WHO-DASII). For criterion validity the Brief Psychiatric Rating Scale (BPRS) 24-item version was applied. RESULTS. The sufficient and good validity indices were obtained for concurrent validity of GSDSII. There was also a significant interrelation between psychopathology assessed with BPRS and disability measured by GSDSII.

CONCLUSIONS

Results allow for the supplication of the GSDSII in the research on psychosocial disability in Poland.

[Experimental studies in Polish psychiatric journals]

AIM

Scientific studies in psychiatry from a methodological point of view could be divided into correlational and experimental. Experimental studies are based on active selection of independent and dependent variables, attributing values of the independent variable to persons under study and measuring values of dependent variables. An example of the experimental study is a comparison of two therapeutic methods. Experiments are feeble to selection, informational and confounding bias.

METHOD

This review comprises experimental papers published in journals: "Psychiatria Polska", "Postepy Psychiatrii i Neurologii", "Farmakoterapia w Psychiatrii i Neurologii", "Rocznik Psychogeriatryczny", "Wiadomości Psychiatryczne" oraz "Alkoholizm i Narkomania" from January 1998 to December 2002.

RESULTS

11 experimental publications, 6 randomised, 2 probably randomised and 3 case-control studies were found. The smallest study included 14 persons, the largest 180 persons. The number of experimental groups varied from 2 to 4. 9 studies evaluated features of specific methods of therapy and rehabilitation, among them 6 evaluated efficacy of medications. 2 studies evaluated relations between psychopathological and physiological variables. Experiments were based on groups of patients with a diagnosis of schizophrenia (3), alcohol and drug dependence (2), depression (3), insomnia (1), bronchial asthma (1), and hypertension (1).

CONCLUSION

The review showed that experimental studies do not form a main-stream in Polish psychiatric journals.

[The impact of lead and cadmium on the immune system]

A long-lasting exposure to lead and cadmium may cause changes in the immune response. Until now only a few reports have addressed this problem. At present, the direct immunotoxicity of heavy metals is the subject of extensive studies, especially on in vitro models. Heavy metals may regulate the immune response of the body at its different stages, modifying early and late inflammatory reactions, among others through changing the number of circulating B and T lymphocytes, NK cells and immunological memory cells. Some authors show that lead and cadmium stimulate the production of cytokines and IgE antibodies, which can be the reason for the increased number of atopic diseases in populations exposed to these two metals. Clinical tests in patients occupationally exposed to lead revealed the diminished number of B and T lymphocytes, and a considerable decrease in the number of NK cells. Other authors noted the increased number of CD8+ lymphocytes, which play a pivotal role in cytotoxic response, and the decreased number of B lymphocytes together with the increased IgA levels in policemen of road services. In copper smelters some changes in humoral response can be detected, e.g. a lower production of IgA and IgG, predisposing them to infections and cancers. To elucidate the exact impact of heavy metals on the immunological response further investigations are required. The growing pollution of the environment by heavy metals probably contributes to the enhanced incidence of allergic diseases and cancers in urban populations. Our goal should be to identify the mechanisms responsible for the changes in the immunological response induced by lead and cadmium, so that it could be possible to reduce or minimize serious pathologies resulting from the exposure to these metals.

[Berylliosis in the work environment: etiology and medical treatment]

Beryllium is a metal responsible for the incidence of chronic beryllium disease--an illness affecting from 2 to 5% of workers exposed to this metal and its compounds. There is a growing evidence provided by epidemiological and toxicological studies that exposure limits for workers dealing with beryllium should be revised. This paper gathers epidemiological and pathological data particularly on chronic beryllium toxicity and carcinogenesis. It also reviews the most important aspects of beryllium toxicology and explains the mechanisms of its effect on humans. In addition, the paper presents suggestions on the diagnosis and treatment of berylliosis. The content of the paper is based on medical data, as well as on reference materials of national and international organizations and governmental agencies.

[Urinary trehalase activity as an indicator of renal dysfunction in lead smelters]

Epidemiological and experimental studies have demonstrated that lead and cadmium are responsible for renal dysfunction. Urinary trehalase is known as a good marker of proximal tubular renal brush border destruction in the population environmentally exposed to cadmium. The aim of this study was to determine the impact of occupational exposure to lead on the renal function and urinary trehalase activity. The study was carried out in 68 workers, aged 46 +/- 6 years, employed in a copper foundry. Blood lead, cadmium, copper and manganese concentrations were measured by atomic absorption spectrophotometry. Urinary trehalase activity was determined by the method of Nakano and Itoh. Trehalase activity was increased in copper smelters as compared to controls. There also was a positive linear correlation between blood lead level and urinary trehalase activity (r = 0.44; p < 0.05). Negative correlations between blood lead and copper concentrations (r = -0.30; p < 0.05) and between serum copper and trehalase level (r = 0.68; p < 0.001) were found. The results show that urinary trehalase activity could be a good indicator of the renal brush border dysfunction in copper smelters. This marker could be useful in the early diagnosis of nephrotoxic effect of lead.

[Effect of arsenic and its compounds on the circulatory system]

Arsenic is a metal which occurs widely in both occupational and physical environments. Therefore, its easy accessibility and high toxicity raise the question on whether arsenic, particularly in relatively small doses, can cause damage of relevant molecular, biochemical and clinical significance to the cardiovascular system. The present review is focused on the confirmed and potential mechanisms of arsenic effect on the function and structure of vascular endothelium (nitric oxide, peroxynitrite), its role in stimulating the oxidative species formation (hydroxyperoxide, superoxide and lipid peroxide formation), as well as in decreasing the antioxidative response (enzymes: superoxide dysmutase, catalase, glutation peroxidase), its cytotoxic effects, including immunotoxic properties, arsenic action in the signal transduction pathways network (kinases and DNA transcription factors), impact on cell proliferation, differentiation and apoptosis, not to mention its interference with DNA synthesis and repair processes. Apart from mechanisms of arsenic action, the article provides the up-to-date information on various cardiovascular diseases of the established or presumed arsenic origin.

[Serum selectin E level in lead-exposed workers]

Lead is recognised as a potential atherogenic factor. One of the earliest events in the development of atherosclerosis is monicyte attachment to the endothelial surface. This is followed by recruitment of monocytes into the subendothelial space and ingestion of modified LDL by these cells. In turn, modified LDL stimulates endothelial cells to induce expression of proinflammatory adhesion molecules, such as selectins, which further promote monocyte migration. It was observed that atherosclerotic vascular damage is associated with increased level of circulating selectin E. The aim of this study was to determine the impact of the occupational exposure to lead on the serum selectin E level. The study involved 80 patients, including 37 workers of a copper foundry and 43 people not exposed to lead. The subjects were matched in pairs according to sex, age and cholesterol concentration in blood. There were 25 hipercholesterolemic pairs and 9 pairs with normal serum total cholesterol. People exposed to lead had higher (about 7 ng/ml) serum selectin E concentration than those not exposed. There was positive linear correlation between selectin E and triglycerides in the whole group (p < 0.01), and the strongest correlation was observed in the group of subjects not exposed to lead (aged 40-60, r = 0.74). In the context of the described hypertriglyceridemic action induced by lead, these results suggest that lead could potentially act as an atherogenic factor in the early, inflammatory stage of atherosclerosis.

[The results of surgical treatment of patients with laryngeal carcinoma in years 1988-1989 in four departments of otorhinolaryngology]

In a group of 579 patients with laryngeal carcinoma treated surgically in years 1988-1989 in four departments of otorhinolaryngology of the Medical Academies in Poznań, Warsaw, Cracow and Lublin, 72% survived 3 years without recurrence and 59% survived 5 years. Similar results were obtained in years 1986-1987. The authors discuss in detail the reasons for failures of the surgical treatment, i.e.: supraglottic localization of the cancer, its extensiveness in the larynx, the stage of clinical development, general condition of the patient, effectiveness of the operation, regularity of postsurgical examination, the degree of histological malignancy, blood transfusion during the operation, distant metastases, little efficiency of medical service in early diagnosis of laryngeal cancer, avoiding postsurgical radiation, subjective factors of the patients and the choice of the optimal method of the treatment. Few patients can be cured if the initial treatment fails.

[Efficiency of surgical treatment in patients with laryngeal cancer depending on age]

In the group of 578 patients with larynx cancer that underwent surgical treatment in four clinics of Medical Academies between 1986-87 a comparable analysis of the efficiency of surgical treatment depending on age of the operated patients was carried out. It was found that the difference between age average and the general state of patients was statistically highly important: Statistically significant was also the dependence between the patients' age and the postoperative complications; close to importance was also the dependence between the age and the survival period of patients. 68% of operated patients up to 65 year of age had five-year survival period without any symptoms; but in the group of patients over 65 years of age the analogical survival value was 51%.

[Therapeutic and diagnostic difficulties with parapharyngeal tumors]

Tumors of the parapharyngeal space are not very common. The case with big tumor of the parapharyngeal space was described, primary misdiagnosed as the tumor of the parapharyngeal tonsil and then as the tumor of the soft palate. The tumor was removed finally from the external parotido-cervical approach.

[The clinical significance of metastatic cancer of the larynx to the Delphi node]

Between years 1965-1987, 920 patients with cancer of the larynx were operated on. In this time we identified 9 cases of histologically proven metastasis to the Delphian node. In all patients except one, the neck was clinically negative but a positive Delphian node was discovered at partial or total laryngectomy. Five patients developed metastasis postoperative. Seven of 9 patients have died from their laryngeal cancer. The frequency of neck metastasis and local recurrences is very high in patients with a positive Delphian node.