Predrag Sazdanovic

Occipital sulci of the human brain: variability and morphometry

The external morphology of the occipital lobe was investigated in 15 human post-mortem brains (30 hemispheres) fixed in formalin. We identified, described and measured the lengths of nine major human occipital sulci and five variable ones, comparing both types between individuals and hemispheres. Morphological variability of human occipital sulci is related to interindividual and interhemispheric differences in their presence, origin, type, segmentation, intersection and length. The major occipital sulci, particularly the parieto-occipital, the calcarine, the inferior lateral occipital and the anterior occipital sulci, as well as two points of their intersections (cuneal point and intersection of the transverse occipital and superior occipital sulcus) may be used as reliable anatomical landmarks for the location of architectonically and functionally defined human visual areas (V1, V2, V3, V3A, V5/MT+, LO1 and LO2) and during less invasive neurosurgical procedures in the cases of focal lesions within the occipital lobe. Two lateral occipital sulci (inferior and superior) were defined on the lateral surface of the occipital lobe. The variable lunate sulcus was studied and combining our results with those from histological and functional imaging studies, we suggest that the lunate sulci of human and nonhuman primates are not homologous.

Types of neurons and some dendritic patterns of basolateral amygdala in humans--a golgi study.

Classification of the neurons in the human basolateral amygdala is performed on preparations impregnated by the Golgi technique. Three different neuronal types are found in the nuclei of the basolateral amygdala: Type I--Pyramidal cells, with numerous dendritic spines and two subtypes (slender and squat); Type II--Modified pyramidal cells, sparsely spinous with rare dendritic spines and two subtypes (single apical and double apical) and; Type III--Non-pyramidal cells, with few dendritic spines and three subtypes (bipolar, multipolar and gliaform). The analysis of the primary dendritic branches pointed out the occasional presence of dendritic bundles (fascicular dendritic arrangement) with their predomination in the parvicellular division of the basal nucleus and paralaminar nucleus. Additionally, the presence of dendrodendritic contacts, indicated by light microscopy, was also found in the parvicellular division of the basal nucleus and especially in the paralaminar nucleus.

Pharmacokinetics of linezolid in critically ill patients.

ABSTRACT Introduction: Linezolid is an oxazolidinone antibiotic active against Gram-positive bacteria, and is most commonly used to treat life-threatening infections in critically ill patients. The pharmacokinetics of linezolid are profoundly altered in critically ill patients, partly due to decreased function of vital organs, and partly because life-sustaining drugs and devices may change the extent of its excretion. Areas covered: This article is summarizes key changes in the pharmacokinetics of linezolid in critically ill patients. The changes summarized are clinically relevant and may serve as rationale for dosing recommendations in this particular population. Expert opinion: While absorption and penetration of linezolid to tissues are not significantly changed in critically ill patients, protein binding of linezolid is decreased, volume of distribution increased, and metabolism may be inhibited leading to non-linear kinetics of elimination; these changes are responsible for high inter-individual variability of linezolid plasma concentrations, which requires therapeutic plasma monitoring and choice of continuous venous infusion as the administration method. Acute renal or liver failure decrease clearance of linezolid, but renal replacement therapy is capable of restoring clearance back to normal, obviating the need for dosage adjustment. More population pharmacokinetic studies are necessary which will identify and quantify the influence of various factors on clearance and plasma concentrations of linezolid in critically ill patients.

Chromosomal Instability in Peripheral Blood Lymphocytes of Patients with Reproductive Failure Assessed by Micronucleus Assay

We investigated chromosomal instability in peripheral blood lymphocytes (PBL) of patients with reproductive failure in respect to age, smoking habits, gender, miscarriages, and semen parameters. The study involved 36 individual cases of reproductive failure (18 men and 18 women) attended at the Clinical Centre of Kragujevac, Serbia, and 30 healthy subjects (15 men and 15 women). Micronuclei (MN) frequency was estimated in PBL using the cytokinesis-block micronucleus (CBMN) assay. The baseline MN frequencies were signifi cantly higher (p=0.031; p<0.001) in male [(9.22 ± 4.70) MN per 1000 BN cells] and female patients [(13.50 ± 2.5) MN per 1000 BN cells] than in male and female healthy controls [(6.27 ± 2.66) MN per 1000 BN cells; (6.80 ± 2.98) MN per 1000 BN cells]. The mean baseline MN frequency did not signifi cantly differ between miscarriage groups and between patients with and without normal values of semen parameters. The correlations between poor sperm concentration (<20x106 mL-1), rapid progressive motility (<25 %), normal morphology (<30 %), and MN frequencies were negative, but not statistically signifi cant. We found that only gender signifi cantly infl uenced the MN rates in analysed patients. There were no signifi cant differences between age groups and between smokers and non-smokers in patients and control samples. We conclude that the increase in baseline MN frequency in PBL of patients with reproductive failure corresponds to the increase in chromosomal damage, which occurs as a result of complex events that cause reproductive disorders.

Augmented oxidative stress in infertile women with persistent chlamydial infection

There is established association between oxidative stress, infections of genital tract and fertility. Genital tract infections may provoke increased production of free radicals and generate oxidative stress that can be involved in pathophysiology of a number of reproductive diseases and complications during pregnancy. The aim of this study was to determine connection between oxidative stress and infertility associated with persistent chlamydial infection. Serum samples of infertile women with tubal factor infertility (TFI), women with multiple spontaneous abortions (MSA) and fertile women was screened for C. trachomatis MOMP specific IgG and IgA antibodies and cHSP60 specific igG antibodies using ELISA. The levels of superoxide anion radical, nitric oxide and reduced glutathione were determined spectrophotometricaly. Serum levels of testosterone, luteinizing hormone and follicle stimulating hormone were determined by enzyme-linked fluorescent immunoassay method. Our results showed that persistent infection was more prevalent in TFI than in MSA group, whereas seropositivity was higher in MSA than in TFI group of patients. We also found that superoxide anion was significantly lower, while LH was markedly higher in TFI and MSA group of patients. However, when our results were analyzed according to the serological status of chlamydial infection, we found that parameters of oxidative stress, superoxide anion and index of oxidative stress, defined as relative ratio between superoxide anion and nitrites sum and glutathione ((O2-+NO2-)/GSH) were significantly elevated in infertile patients with persistent chlamydial infection compared to seropositive and seronegative patients. Our findings point to the possible impact of Chlamydia trachomatis infection on prooxidative-antioxidative balance that can influence fertility potential in women with persistent chlamydial infection.

Neurons of human nucleus accumbens.

BACKGROUND/AIM Nucleus accumbens is a part of the ventral striatum also known as a drug active brain region, especially related with drug addiction. The aim of the study was to investigate the Golgi morphology of the nucleus accumbens neurons. METHODS The study was performed on the frontal and sagittal sections of 15 human brains by the Golgi Kopsch method. We classified neurons in the human nucleus accumbens according to their morphology and size into four types: type I--fusiform neurons; type II--fusiform neurons with lateral dendrite, arising from a part of the cell body; type III--pyramidal-like neuron; type IV--multipolar neuron. The medium spiny neurons, which are mostly noted regarding to the drug addictive conditions of the brain, correspond to the type IV--multipolar neurons. RESULTS Two regions of human nucleus accumbens could be clearly recognized on Nissl and Golgi preparations each containing different predominant neuronal types. Central part of nucleus accumbens, core region, has a low density of impregnated neurons with predominant type III, pyramidal-like neurons, with spines on secondary branches and rare type IV, multipolar neurons. Contrary to the core, peripheral region, shell of nucleus, has a high density of impregnated neurons predominantly contained of type I and type IV--multipolar neurons, which all are rich in spines on secondary and tertiary dendritic branches. CONCLUSION Our results indicate great morphological variability of human nucleus accumbens neurons. This requires further investigations and clarifying clinical significance of this important brain region.

Morphology of Human Nucleus Accumbens Neurons Based on the Immunohistochemical Expression of Gad67

Abstract The nucleus accumbens is a part of the ventral striatum along with the caudate nucleus and putamen. The role of the human nucleus accumbens in drug addiction and other psychiatric disorders is of great importance. The aim of this study was to characterize medium spiny neurons in the nucleus accumbens according to the immunohistochemical expression of GAD67. This study was conducted on twenty human brains of both sexes between the ages of 20 and 75. The expression of GAD67 was assessed immunohistochemically, and the characterization of the neurons was based on the shape and size of the soma and the number of impregnated primary dendrites. We showed that neurons of the human nucleus accumbens expressed GAD67 in the neuron soma and in the primary dendrites. An analysis of the cell body morphology revealed the following four different types of neurons: fusiform neurons, fusiform neurons with lateral dendrites, pyramidal neurons and multipolar neurons. An immunohistochemical analysis showed a strong GAD67 expression in GABAergic medium spiny neurons, which could be classifi ed into four different types, and these neurons morphologically correlated with those described by the Golgi study.

Fractal analysis of dendritic arborization patterns of pyramidal neurons in human basolateral amygdala

Background It is well known that there is important role of amygdala in emotional-cognitive processes, i.e. in emotional and associative learning, fear acquisition and emotional memory [1]. We investigated dendritic branching patterns of pyramidal neurons which are believed to be excitatory. According to our earlier findings pyramidal neurons in human basolateral amygdala have two subtypes pyramidal slender and pyramidal squat neurons [2]. Fractal analysis, which comes from Mandelbrots fractal geometry [3], is used as a tool for differentiation of the complexity of neuronal dendritic branching patterns. The measure of dendritic branching represents the fractal dimension of the neuron. In performing this study, we have applied the fractal analysis to the images of neurons, in order to investigate its capability to distinguish between subtypes.