Viral hepatitis delta in the republic of Belarus

26,740 blood donors and persons of high risk groups with respect to HBV infection, residing in different regions of Belarus, were examined for the presence of HBsAg in 1983-1997. Of these, 1372 persons (5.1%) were found to have HBsAg, and out of 1081 HBsAg-positive persons anti-HDV antibodies (Ab) were detected in 96 persons (8.9%). In spite of a decrease in acute virus hepatitis B morbidity and in HBsAg carriership, the occurrence of anti-HBV Ab remained stable during the period of 16 years and was equal, on the average, about 4% among asymptomatic HBsAg carriers. Patients having tuberculosis, rheumatoid arthritis, diabetes mellitus, hematological diseases, chronic hepatitides and cirrhosis of the liver were an important reservoir of HBV and HDV infections for regions with the low level of the spread of HBV. A decrease in the detection rate of anti-HDV Ab in patients with cirrhosis of the liver from 47.6% to 15.4% was noted. In 1991-1997 a decrease in the detection rate of anti-HDV Ab in patients with chronic hepatic lesions in comparison with 1983-1990 was observed, and in the age group older than 50 years this decrease was from 33.3% to 8.3%. This difference was particularly pronounces in patients with cirrhosis of the liver: 53.9% and 7.7% respectively.     

Plasma levels of arginine vasopressin elevated in patients with major depression

Mentally healthy subjects show increased plasma concentrations of the neuropeptides, arginine vasopressin (AVP) and oxytocin (OT), under conditions of stress, but data are lacking about plasma concentrations of AVP and OT in patients with major depression. We thus assessed plasma concentrations of AVP and OT in patients with major depression (n = 52) and healthy controls (n = 37). Mean plasma AVP concentrations were higher in the group of depressed patients than in controls. A subgroup of 16 patients showed very high levels of plasma AVP, but no other feature differentiating this subgroup from the other patients was found. In-patients showed higher plasma AVP levels than out-patients, and melancholic patients had higher plasma AVP levels than did nonmelancholic patients. Plasma AVP levels were slightly related to psychomotor retardation and significantly inversely to neuroticism. Patients' plasma OT concentrations had a wider range than in controls. AVP and AVP-mediated functions may be a factor in the clinical picture of depression, possibly by influencing the activity of the hypothalamic-pituitary-adrenal axis.     

Destabilization of beta-catenin by mutations in presenilin-1 potentiates neuronal apoptosis

Mutations of the presenilin-1 gene are a major cause of familial early-onset Alzheimer's disease. Presenilin-1 can associate with members of the catenin family of signalling proteins, but the significance of this association is unknown. Here we show that presenilin-1 forms a complex with beta-catenin in vivo that increases beta-catenin stability. Pathogenic mutations in the presenilin-1 gene reduce the ability of presenilin-1 to stabilize beta-catenin, and lead to increased degradation of beta-catenin in the brains of transgenic mice. Moreover, beta-catenin levels are markedly reduced in the brains of Alzheimer's disease patients with presenilin-1 mutations. Loss of beta-catenin signalling increases neuronal vulnerability to apoptosis induced by amyloid-beta protein. Thus, mutations in presenilin-1 may increase neuronal apoptosis by altering the stability of beta-catenin, predisposing individuals to early-onset Alzheimer's disease.     

Cell kinetics of head and neck cancers

We measured the tumor cell proliferative rate in 26 patients with head and neck cancer, 22 of which were squamous cell carcinomas (SCCs). Patients received sequential infusions of iododeoxyuridine and bromodeoxyuridine, after which the tumor was biopsied and studied. The percentage of labeled cells [labeling index (LI)] in well-differentiated SCCs was 20.4 +/- 2.7% (mean +/- SE) and 23.8 +/- 2.1% in moderately differentiated SCCs (P = 0.135). The LIs of two poorly differentiated SCCs were 39.4 and 55.9%. The LI was 2.5% in a high-grade lymphoepithelioma and 24.8% in a malignant lymphoma. In one well-differentiated and one poorly differentiated mucoepidermoid tumor, the LIs were 3.0% and 29.1%, respectively. S-phase duration time measurements ranged from 5.1-21.5 h (12.8 +/- 1.5). The calculated potential doubling times ranged from 18.8-84.5 h (47.3 +/- 6.7). The duration of G2 was between 90 and 180 min. To track the fate of labeled cells, in four patients a repeat biopsy was obtained 7-14 days after the iododeoxyuridine/bromodeoxyuridine infusion. These patients did not receive treatment between the biopsies. Due to the dilution of the label, most labeled cells in the second biopsy demonstrated a "fragmented" pattern resulting from repeated cell divisions. In two patients, however, 25% of cells in the second biopsy had undiluted label, suggesting that these cells had not divided after incorporating iododeoxyuridine/bromodeoxyuridine. On Day 7 labeled cells migrated to keratinized parts of tumors and to necrotic foci. Thus, the arrest of cell cycle transition, tumor cell differentiation, and cell death may be major routes of tumor cell loss from the proliferative compartment. This may explain the difference between very short potential doubling times and the actual rate of tumor growth.     

Recurrent nerve palsy after thyroid operations--principal nerve identification and a literature review

Conventional x-ray angiography (XRA) images are projections of the vasculature with high spatial and temporal resolution, while magnetic resonance (MR) angiography (MRA) and MR imaging data show the three-dimensional locations of vessels relative to brain parenchyma. The authors have developed a retrospective method of registering these studies, which makes it practical to produce multimodality displays of this complementary information. Registration was performed by matching vessels seen on both XRA and MRA images. First, the authors determined the coordinates of the center lines of a few "landmark" vessels on the XRA image and the three-dimensional locations of the corresponding intraluminal voxels in the MRA volume. Registration was performed by rotating and translating the MRA-MR imaging volume until the perspective projection of the MRA landmark vessels matched the corresponding vessel center lines on the XRA image. Experiments with phantoms and patients indicated that the two studies were registered with an average error of less than 2 mm. A linked-cursor display was developed to show correspondence between points on the registered XRA and MRA-MR images.     

The hemispheric functional specialization of visual perception

In this review the modern concepts on psychophysical mechanisms of hemispheric functional specialization of human visual perception are considered. The problems are discussed on three basic historical aspects: interhemispheric relations in patients with localized cerebral lesions, interhemispheric differences in the "Bisected Brain", and the functional asymmetry in the intact brain. The neuropsychological data on recognition of geometric figures, faces and objects, and also electrophysiological results on the event-related brain potentials are deliberated. Special attention is given to the own data of authors dedicated to importance role of the right hemisphere in the brain interhemispheric functional asymmetry in control subjects and alcoholics. Several problems on learning and influence of emotions on visuospatial recognition are discussed. The dichotomous approach to brain functional asymmetry are not shared, the hypothesis on intersupplementary cooperation in hemispheric specialization and interaction of the brain hemispheres are supported.     

Implantable cardioverter-defibrillators and the pathologist: comment and cautionary notes

This paper briefly reviews the components of, the clinical uses of, the techniques to place, and the complications related to implantable cardioverter-defibrillators (ICDs). Information useful in the specific identification of ICDs is presented. A series of recommendations for the autopsy examination or postmortem explantation of ICDs by the pathologist is given. Because of the serious risk of injury to the pathologist possible with postmortem discharges of ICDs which have not been deactivated, and because of the risk of device explosion if the ICD is incinerated, a number of cautionary notes are provided. A brief case with occurrence of accidental postmortem discharge of an active ICD is also presented.     

Daily cycle of bHLH-PAS proteins, Ah receptor and Arnt, in multiple tissues of female Sprague-Dawley rats

The aryl hydrocarbon receptor (AhR) shares a common PAS domain with a number of genes that exhibit a pronounced circadian rhythm. Therefore, this study examined the daily cycle of AhR and AhR nuclear translocator (Arnt) protein expression in multiple tissues of female Sprague-Dawley rats. Rats were euthanized at 4, 7, and 11 am and 4, 7, and 11 pm after which whole tissue homogenates were made from multiple tissues. Western blot analysis showed that the daily cycle of relative AhR protein expression exhibits a similar oscillation pattern in the liver, lungs, and thymus. The daily cycle of relative Arnt protein expression exhibits a similar oscillation pattern in the liver and lungs. The apparent daily cycle of AhR and Arnt protein expression in multiple tissues was not observed within the spleen. This preliminary report is the first study to suggest that the PAS proteins, AhR and Arnt, exhibit a daily oscillation pattern within multiple target tissues which may give insight into the tissue-specific toxic and biochemical responses mediated through this dimerization pair, as well as the physiological function of these proteins.     

Peptidergic mechanisms in the parasympathetic regulation of the heart rate

Besides the classic cholinergic and adrenergic mechanisms, the regulatory peptides involve in regulating the cardiac rhythm. The localization of the latter in neurons of intracardiac nervous system as well as the possibility of releasing the regulatory peptides, individually or in combination with the classic mediators, during extracardiac nerves is found. The regulatory peptides are capable of affecting the heart autonomy directly or in a mediated way via modulation of the vegetative effects. The paper contains data on the cardiotropic activity of various peptides and direction of their effects relating to parasympathetic control a cardiac rhythm. There is a suggestion concerning an existence of different ways of realization of peptidergic vagotropic effect that presupposes not only variation of severity of parasympathetic chronotropic effect but also a change in its functional organization.     

Skeletal and cardiac malformations with thrombocytopenia: a new syndrome?

We describe a female patient with multiple anomalies suggestive of a new syndrome. Manifestations include: VSD and ASD, mild developmental delay, conductive hearing loss, minor facial anomalies, thrombocytopenia, and radiological findings (including carpal fusion). Some of these manifestations may be present in the Keutel syndrome, IVIC syndrome, and the 10qter deletion syndrome. However, none of these syndromes can explain the spectrum of anomalies seen in our patient.