Brain biopotential mapping in emotional and cognitive pathology

The EEG rhythms spectral power and intracortical connections were studied in depressive and schizophrenic patients in four schematically outlined main cortical quadrants. In depressive patients two cortical quadrants--right anterior and left posterior ones appeared to be predominantly involved in negative emotions regulation. Alpha-rhythm spectral power and cortical connections in these areas were decreased, pointing to their relative hyperactivation and functional disturbances. Schizophrenics patients were divided into two groups--with the predominance of "positive" and "negative" symptoms. In the first group there was revealed the decrease of the most EEG rhythms spectral power only in parietal areas, on the second one--in all cortical areas. There was also the significant alpha-rhythm spectral power asymmetry, different in the two groups of schizophrenic patients. In "positive" schizophrenics the decrease of alpha-rhythm spectral power was revealed in parietal and occipital areas of the right hemisphere, and in "negative" ones--vice versa, these results pointing of the relatively higher activation of the right posterior quadrant in the former group and of the left posterior quadrant in the latter one. In the anterior cortical quadrants the intracortical connections were however higher in the left hemisphere in "positive" and in the right one--in "negative" schizophrenics. Thus, there are some contradictory results obtained by different methods in anterior and posterior cortical quadrants in each hemisphere, these results being of opposite directions in patients with "positive" and "negative" manifestations. "Region of interest" (ROI) in schizophrenics appeared to be predominantly the frontal and temporal ones, while the "Rhythm of interest"--beta2.     

Simultaneous bleaching of vital teeth and an open-chamber nonvital tooth with 10% carbamide peroxide

OBJECTIVE: The purpose of this study was to evaluate the effectiveness of bleaching a nonvital tooth with an open pulp chamber while simultaneously bleaching the other vital teeth with 10% carbamide peroxide. METHOD AND MATERIALS: Ten discolored nonvital teeth were treated. Each nonvital tooth was prepared as in the conventional "walking bleaching" fashion, so that the gutta-percha was sealed from the pulp chamber. The 10% carbamide peroxide was injected into the chamber of the nonvital tooth and loaded into the custom-fitted tray for all teeth. The nonvital teeth were bleached from both the inside and the outside. The patient closed the orifice with a cotton pellet during the day and changed the cotton pellet after meals. The patient applied fresh solution nightly. RESULTS: All teeth were successfully lightened. The time required to lighten the nonvital tooth was related to the duration of the discoloration. CONCLUSION: With proper patient selection and education, this technique can provide an effective way to lighten nonvital and vital teeth simultaneously, especially where extended treatment time may be required for difficult discolorations.     

DNA sequence-dependent deformability deduced from protein-DNA crystal complexes

The deformability of double helical DNA is critical for its packaging in the cell, recognition by other molecules, and transient opening during biochemically important processes. Here, a complete set of sequence-dependent empirical energy functions suitable for describing such behavior is extracted from the fluctuations and correlations of structural parameters in DNA-protein crystal complexes. These elastic functions provide useful stereochemical measures of the local base step movements operative in sequence-specific recognition and protein-induced deformations. In particular, the pyrimidine-purine dimers stand out as the most variable steps in the DNA-protein complexes, apparently acting as flexible "hinges" fitting the duplex to the protein surface. In addition to the angular parameters widely used to describe DNA deformations (i.e., the bend and twist angles), the translational parameters describing the displacements of base pairs along and across the helical axis are analyzed. The observed correlations of base pair bending and shearing motions are important for nonplanar folding of DNA in nucleosomes and other nucleoprotein complexes. The knowledge-based energies also offer realistic three-dimensional models for the study of long DNA polymers at the global level, incorporating structural features beyond the scope of conventional elastic rod treatments and adding a new dimension to literal analyses of genomic sequences.     

Bedside activated partial thromboplastin time monitoring: just a matter of time?

Hydraulic Engineering, a junior∕senior-level course, is typically taught in a lecture-based format. Lecturing as a singular teaching technique has repeatedly been shown to be ineffective. Lecturing does not advance problem-solving skills, does not require creative or critical thinking, and does not prepare students for the types of problems they will face as professional engineers. In this study, two teaching techniques, problem-based learning (PBL) and cooperative learning (CL), were used to enhance learning in the hydraulic engineering course. The goals of PBL are to provide the student with an active role in learning and to allow the student to take responsibility for learning. The goals of CL are to have students work in teams, thereby learning from both each other and the instructor, and to teach students to work together cooperatively in small groups. Methods of developing teams, projects, and other assignments were explored. The course was assessed midterm and at the end of the semester. As a result, some changes were made midsemester and other recommendations are made for the future.     

Nested PCR assay for detection of granulocytic ehrlichiae

A sensitive and specific nested PCR assay was developed for the detection of granulocytic ehrlichiae. The assay amplifies the 16S rRNA gene and was used to examine acute-phase EDTA-blood and serum samples obtained from seven humans with clinical presentations compatible with human granulocytic ehrlichiosis. Five of the seven suspected cases were positive by the PCR assay using DNA extracted from whole blood as the template, compared with a serologic assay that identified only one positive sample. The PCR assay using DNA extracted from the corresponding serum samples as the template identified three positive samples. The sensitivity of the assay on human samples was examined, and the limit of detection was shown to be fewer than 2 copies of the 16S rRNA gene. The application of the assay to nonhuman samples demonstrated products amplified from template DNA extracted from Ixodes scapularis ticks collected in Rhode Island and from EDTA-blood specimens obtained from white-tailed deer in Maryland. All PCR products were sequenced and identified as specific to granulocytic ehrlichiae. A putative variant granulocytic ehrlichia 16S rRNA gene sequence was detected among products amplified from both the ticks and the deer blood specimens.     

Regulation of the preovulatory gonadotropin surge by endogenous steroids

Estradiol secreted by growing ovarian follicle(s) has been considered classically to be the neural trigger for the preovulatory surge of gonadotropins. The observation that the estradiol-induced gonadotropin surge in ovariectomized rats is of lesser magnitude and duration than that found in the cycling rat at proestrus has resulted in a search for other steroid regulators. Progesterone is a major regulator of the preovulatory gonadotropin surge. It can only act in the presence of an estrogen background, which is necessary for the synthesis of progesterone receptors. In the estrogen-primed ovariectomized rat, progesterone is able to initiate and enhance the gonadotropin surge to the magnitude observed on the day of proestrus and limit it to 1 day. The physiological role of progresterone in the induction of the preovulatory gonadotropin surge has been demonstrated by the attenuation of the progesterone-induced surge and the endogenous proestrus surge by progesterone receptor antagonist RU486 and the progesterone synthesis inhibitor trilostane. The promoter region of the follicle-stimulating hormone (FHS)-beta gene contains multiple progesterone response elements and progesterone brings about FSH release as well. The reduction of progesterone in the 5 alpha-position appears to be important for the regulation of progesterone secretion. Corticosteroids appear to play a significant role in the secondary FSH surge on late proestrus and early estrus.     

Historical stages in the development of maxillofacial surgery and stomatology at the N. N. Burdenko Main Military Clinical Hospital

Effect of level of dietary calcium on body adaptation to radionuclides and lead exposure was studied in experiments with rats. Effectivity of adaptation was evaluated by analysis of accumulation and elimination of xenobiotics and antioxidant activity of liver tissue and erythrocytes. Low and normal levels of calcium in diet of rats do not provide for long-term adaptation to exposure of Ce-137 and Pb. The diet enriched by calcium caused a significant protective-adaptation effect on stages of accumulation and biotransformation of xenobiotics.