Hemispheric comparisons of neuron density in the planum temporale of schizophrenia and nonpsychiatric brains.

Postmortem and in vivo studies of schizophrenia frequently reveal reduced cortical volume, but the underlying cellular abnormalities are incompletely defined. One influential hypothesis, especially investigated in Brodmann's area 9 of prefrontal cortex, is that the number of neurons is normal, and the volume change is caused by reduction of the surrounding neuropil. However, studies have differed on whether the cortex has the increased neuron density that is predicted by this hypothesis. In a recent study of bilateral planum temporale (PT), we reported smaller volume and width of the outer cortex (layers I-III), especially in the left hemisphere, among subjects with schizophrenia. In the present study, we measured neuron density and size in the same PT samples, and also in prefrontal area 9 of the same brains. In the PT, separate stereological measurements were made in layers II, IIIc, and VI, whereas area 9 was sampled in layer IIIb-c. In both cortical regions, there was no significant effect of schizophrenia on neuronal density or size. There was, nevertheless, a trend-level right>left hemispheric asymmetry of neuron density in the PT, which may partially explain the previously reported left>right asymmetry of cortical width. In schizophrenia, our findings suggest that closer packing of neurons may not always explain reduced cortical volume, and subtly decreased neuron number may be a contributing factor.

Evaluation of APOE Genotype and Vascular Risk Factors As Prognostic and Risk Factors for Alzheimer's Disease and Their Influence On Age of Symptoms Onset.

BACKGROUND: Alzheimer's disease (AD), the most common cause of dementia, is evolving to become a threatening epidemy of the 21st century. Only 21% of the predicted number of AD patients in Macedonia have been diagnosed and treated, which means that almost 80% are underdiagnosed or misdiagnosed. Apolipoprotein E gene (APOE) is recognised as the strongest genetic risk factor for sporadic AD. Whether and when Alzheimer's disease develops, depends on the very complex interaction between genetic and modifiable risk factors. It has been known that vascular factors like hypertension, diabetes mellitus, hypercholesterolemia and obesity increase the risk of developing both AD, vascular dementia and mixed AD and vascular pathology. AIM: This study aims to evaluate the influence of APOEε4 allele presence and modifiable vascular risk factors (hypertension, diabetes mellitus and dyslipidemia) as prognostic and risk factors for AD and their influence on the age of onset of AD symptoms among 144 AD patients from Macedonia. MATERIAL AND METHODS: Study group of a total of 144 patients diagnosed with AD was evaluated. APOE genotyping was performed using APOE haplotype-specific sequence specific-primer (SSP)-PCR (Polymerase Chain Reaction) methodology. The non-standardized questionnaire was used to obtain information about demographics, lifestyle and modifiable risk factors that could influence disease onset and phenotype. RESULTS: Statistically significant association was found between the presences of APOEε4 allele in AD group versus controls. The presence of APOEε4 allele increases the risk of developing AD in a 3-fold manner. The average age of disease onset in the ε4 carrier group was 67.2 ± 8.3 and in the ε4 non-carrier group 69.7 ± 9.4. This confirms that the presence of APOEε4 allele shifts towards earlier disease onset, though the difference is not statistically significant. Out of the vascular risk factors, only hypertension was significantly associated with earlier AD onset. Out of total 144 patients, in 22.9% the first symptom onset was before the age of 65, that can be considered as early onset Alzheimer's Disease (EOAD), which is much higher than 5% for EOAD as most of the studies report. CONCLUSIONS: The average age of disease onset of 68.4 years could be considered earlier than the average age of AD onset worldwide. Out of all the vascular risk factors analysed in this study, only hypertension and dyslipidemia were found to significantly increase the risk for developing AD and only the presence of hypertension influences the age of onset, shifting towards earlier disease onset. Public awareness campaigns should be organised to influence general population knowledge about Alzheimer's disease, early recognition and the influence of modifiable vascular risk factors.

Optimization of Golgi methods for impregnation of brain tissue from humans and monkeys.

Golgi impregnation is unique in its ability to display the dendritic trees of large numbers of individual neurons. However, its reputation for inconsistency leaves many investigators reluctant to embrace this methodology, particularly for the study of formalin-fixed human brain tissue. After reviewing the literature, testing a variety of technical variations, and discussing the procedure with experienced practitioners, we have concluded that much of the unpredictability can be removed by matching the Golgi technique to the conditions that were used for fixation of the tissue. Briefly fixed tissues worked best with the rapid Golgi technique, which includes osmium during the initial chromation step, and with the Golgi-Cox method, which includes mercuric chloride during chromation. For tissues that have been fixed for several years or even for several decades, superior results are obtained with the Golgi-Kopsch technique, using multiple changes of a chromation solution that contains paraformaldehyde. In the Golgi-Kopsch technique, pH should be used to monitor the reduction of Cr6+ to Cr3+, which is a crucial determinant of successful chromation. With any Golgi technique, agitation throughout the impregnation helps to avoid precipitates and to improve the quality of impregnation. When the appropriate method is chosen, Golgi impregnation is a useful technique for the neuropathologist.

Diatoms in forensic expertise of drowning--a Macedonian experience.

Results obtained by examination of 22 human cases suspected for drowning, one human case of death other than drowning and several tests on laboratory rats were used as a basis for evaluation of diatom method as supportive in forensic expertise of drowning. The recovery of diatoms from various examined organs, their qualitative and quantitative composition, if properly treated without the possibility of contamination, can be a reliable proof of the time and place of drowning. The priority of organ examination (external microflora determination, lungs, brain, heart (and/or blood), stomach, liver and kidney, and finally bone marrow) is discussed and established as well as the basic future research on cases suspected of drowning, but also on non-drowned victims and laboratory animals.

Mitochondrial DNA control region analysis of three ethnic groups in the Republic of Macedonia.

A total of 444 individuals representing three ethnic groups (Albanians, Turks and Romanies) in the Republic of Macedonia were sequenced in the mitochondrial control region. The mtDNA haplogroup composition differed between the three groups. Our results showed relatively high frequencies of haplogroup H12 in Albanians (8.8%) and less in Turks (3.3%), while haplogroups M5a1 and H7a1a were dominant in Romanies (13.7% and 10.3%, respectively) but rare in the former two. This highlights the importance of regional sampling for forensic mtDNA databasing purposes. These population data will be available on EMPOP under accession numbers EMP00644 (Albanians), EMP00645 (Romanies) and EMP00646 (Turks).

Reliable and durable Golgi staining of brain tissue from human autopsies and experimental animals.

BACKGROUND: Golgi stains are notoriously capricious, particularly when applied to human brain. The well-known difficulties, which include complete failure of impregnation, patchy staining, unstable staining, and extensive crystalline deposits in superficial sections, have discouraged many from attempting to use these techniques. A reliable method that produces uniform impregnation in tissue from human autopsies and experimental animals is needed. NEW METHOD: The method described, "NeoGolgi", modifies previous Golgi-Cox protocols (Glaser and Van der Loos, 1981). Changes include: much longer time (>10 weeks) in Golgi solution, agitation on a slowly rocking platform, more gradual infiltration with Parlodion, more thorough removal of excess staining solution during embedding, and shorter exposure to ammonia after infiltration. RESULTS: The procedure has successfully stained over 220 consecutive frontal or hippocampal blocks from more than 175 consecutive human autopsy cases. Dendritic spines are easily recognized, and background is clear, allowing examination of very thick (200 µm) sections. Stained neurons are evenly distributed within cortical regions. The stain is stable for at least eight years. Most importantly, all stained neurons are apparently well-impregnated, eliminating ambiguity between pathology and poor impregnation that is inherent to other methods. COMPARISON WITH EXISTING METHODS: Most methods of Golgi staining are poorly predictable. They often fail completely, staining is patchy, and abnormal morphology is often indistinguishable from poor impregnation. "NeoGolgi" overcomes these problems. CONCLUSION: Starting with unfixed tissue, it is possible to obtain Golgi staining of predictably high quality in brains from human autopsies and experimental animals.