Sagittal Abdominal Diameter as the Best Predictor of Metabolic Syndrome in HIV-Infected Men on Antiretroviral Therapy

BACKGROUND

The interaction of human immunodeficiency virus (HIV), host and antiretroviral therapy causes a range of metabolic disorders that can be characterized as a metabolic syndrome (MetS) that increases the cardiovascular risk. MetS involves central obesity, which can be detected using different anthropometric parameters.

OBJECTIVE

To assess the abilities of different anthropometric parameters in the prediction of MetS in HIV-infected men on ART.

METHOD

The study involved 92 male participants (mean age 44.46±10.38 years), divided into two groups: with and without MetS. All subjects underwent biochemical evaluation (triglycerides, HDL-cholesterol, fasting glucose), blood pressure measurement and anthropometric assessment: body mass, body height, body mass index (BMI), body fat mass, body circumferences (chest, upper arm, forearm, waist, hip, proximal and middle thigh and calf), sagittal abdominal diameter (SAD), skinfold thicknesses (subscapular, anterior and posterior upper arm, anterior and lateral forearm, abdominal, supraspinal, thigh and calf), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), waist-to-thigh ratio (WTR), sagittal abdominal diameter-to-body height ratio (SADH), body adiposity index (BAI) and conicity index. MetS was specified according to IDF criteria.

RESULTS

Subjects with MetS had statistically significant higher values of all anthropometric parameters except middle thigh circumference, calf skinfold and body height. According to ROC analysis and Binary Logistic Regression, SAD has been shown as the best predictor of MetS with a predictive value of 21.40 cm (AUC:0.91), followed by WHR with a predictive value of 0.93.

CONCLUSION

Sagittal abdominal diameter is the strongest anthropometric indicator of MetS in HIV-infected patients on ART.

Influence of physical activity on endothelial function in people living with HIV

INTRODUCTION

Decreased physical activity is a major cardiovascular risk factor that is particularly pronounced in people living with HIV (PLHIV), who are more susceptible to endothelial dysfunction and accelerated atherosclerosis than the general population due to multiple mechanisms. The aim of the present study was to analyse whether regular physical activity is capable of improving endothelial function measured by flow-mediated dilatation (FMD) in PLHIV.

METHODS

We performed FMD measurement in 38 PLHIV, along with the assessment of their regular physical activity level using the International Physical Activity Questionnaire (IPAQ).

RESULTS

Flow-mediated dilatation results in PLHIV were 0.31 ± 0.06 mm and 7.34% ± 1.41% for absolute and relative FMD, respectively. IPAQ results showed that the average weekly level of physical activity was 3631.1 ± 1526.7 MET-min/week, whereas the average daily sitting time was 287.3 ± 102.7 min/day. Predictors jointly accounted for 48% (adjusted value 42%) of FMD variance. Bootstrapped confidence levels revealed that physical activity had a statistically significant effect on the outcome [beta = 0.517, 2.5% confidence interval (CI) = 0.205, 97.5% CI = 0.752].

CONCLUSION

Physical activity represents a widely available and uncostly tool that is capable of improving endothelial function and overall cardiovascular health in PLHIV.

Relation of Steatosis to Neurocognitive Function in People Living with HIV

BACKGROUND

In HIV negative population metabolic syndrome and steatosis are related to poorer neurocognitive (NC) performance. We investigated if similar relation exists in people living with HIV (PLWH).

METHODS

We included male PLWH aged 20-65, with undetectable viral load for at least 6 months. Data on levels of education, anthropometric measurements, CD4 levels, ART, markers of metabolic syndrome, smoking and concurrent treatment were collected from database. Concentrations of TNF-α and IL-6 were measured. An ultrasound was used to establish the presence of steatosis, visceral fat thickness and carotid intima media thickness. An extensive NC assessment was done by an experienced neuropsychologist. Cognitive domains were defined as executive functions, divergent reasoning, visuo-constructional abilities, delayed recall and working memory and learning and were measured using a battery of 12 tests.

RESULTS

88 PLWH were included (mean age 39,9 years), 51% on PIs, 46% on NNRTI; 20,4% had metabolic syndrome, 42% patients had steatosis. Weak but statistically significant negative correlations were found between the presence of metabolic syndrome, steatosis and VFT and cognitive domains (divergent reasoning, delayed recall and working memory). Poorer perfomrance in the domains of divergent reasoning and in the working memory were found in participants with steatosis (p=0,048 and 0,033 respectively).

CONCLUSION

Although the sample size was relatively small, our results show consistent correlations between the observed neurocognitive variables and metabolic parameters. As central obesity is one of the contributors to NCI, it would be one of the modifiable factors to prevent further neurocognitive decline.

Associations of visceral fat thickness and anthropometric measurements with non-alcoholic fatty liver disease development in male patients mono-infected with human immunodeficiency virus

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) represents the most common form of chronic liver disease in mono-infected (without concomitant hepatitis B and/or C virus infection) people living with human immunodeficiency virus (HIV). The proper and on time identification of at-risk HIV-positive individuals would be relevant in order to reduce the rate of progression from NAFLD into non-alcoholic steatohepatitis (NASH), cirrhosis and hepatocellular carcinoma.

OBJECTIVES

The aim of this study was to explore visceral fat thickness (VFT) and anthropometric measurements associated with the development of NAFLD in patients mono-infected with HIV and on long-standing combination antiretroviral therapy (cART).

METHOD

Eighty-eight (n = 88) HIV-positive male patients, average age 39.94 ± 9.91 years, and stable on cART, were included in this prospective study. VFT was measured using ultrasonography. Anthropometric measurements included body mass index (BMI), waist-to-hip ratio (W/H), waist-to-height ratio (WHtR), waist and hip circumference (WC, HC). Differences between variables were determined using the chi-square test. The receiver operating characteristic (ROC) curve and the Youden index were used to determine optimal cut-off values of VFT and hepatic steatosis. The area under the curve (AUC), 95% confidence intervals, sensitivity and specificity are reported for the complete sample. Significance was set at p < 0.05.

RESULTS

Patients with steatosis had significantly higher values of BMI, HC, WC, W/H and WHtR. The VFT was higher in patients with steatosis (p < 0.001). Specifically, VFT values above 31.98 mm and age > 38.5 years correlated with steatosis in HIV-positive patients, namely sensitivity 89%, specificity 72%, AUC 0.84 (95% CI, 0.76-0.93, p < 0.001), with the highest Youden index = 0.61. The sensitivity of the age determinant above this cut-off point was 84%, specificity 73% and AUC 0.83 (95% CI, 0.75-0.92, p < 0.001), with the highest Youden index of 0.57.

CONCLUSION

In the absence of more advanced radiographic and histological tools, simple anthropometric measurements and VFT could assist in the early identification of persons at risk of hepatic steatosis in low- and middle-income regions.

Neurocognitive profile of HIV-positive adults on combined antiretroviral therapy: A single-centre study in Serbia

The advent of combined antiretroviral therapy (cART) has prolonged the life expectancy of HIV + individuals and decreased the incidence of HIV-associated dementia. However, milder forms of neurocognitive impairment remain common and are often associated with poor daily functioning and lower medication adherence. This paper presents a research aimed at exploring the cognitive status differences between HIV + subjects (N = 39) on cART therapy and a group of demographically comparable healthy subjects (N = 39) in Serbia. The significance of differences between the HIV + group and the healthy control group in performance in six cognitive domains was tested using the multivariate analysis of variance. Results showed a lower performance of the HIV + group in the domains of attention/working memory, and learning. HIV-related clinical variables were not significantly associated with cognitive performance. An older age in HIV + patients was significantly related to a lower performance in all six cognitive domains, as opposed to healthy subjects, implying a synergistic interaction between HIV and aging, resulting in accentuated cognitive difficulties. Our findings suggest that even with the absence of a subjective experience of cognitive deficits and with a good basic control of the illness, a certain degree of cognitive deficit can be observed in the tested group.

Adaptation of marine plankton to environmental stress by glycolipid accumulation

A systematic investigation of non-phosphorus containing glycolipids (GL) was conducted in the northern Adriatic Sea during two years at two stations with different nutrient loads. GL concentration varied both spatially and temporally, with values of 1.1-21.5 μg/L and 0.4-44.7 μg/L in the particulate and the dissolved fraction, respectively. The highest concentrations were measured during summer in surface waters and at the more oligotrophic station, where GL yields (% of total lipids) were often higher than 20% and 50% in the particulate and dissolved fractions, respectively. To obtain more insight into factors governing GL accumulation autotrophic plankton community structure (pico-, nano- and microplankton fractions), chlorophyll a, heterotrophic bacteria and nutrient concentrations were measured together with hydrographic parameters and sunlight intensity. During the investigated period smaller autotrophic plankton cells (pico- and followed by nanoplankton) prevailed in abundance over larger cells (microplankton), which were found in large numbers in freshened surface samples. Several major findings resulted from the study. Firstly, during PO4 limitation, particularly at the oligotrophic station, enhanced glycolipid instead of phospholipid accumulation takes place, representing an effective phosphate-conserving mechanism. Secondly, results suggest that at seawater temperatures >19 °C autotrophic plankton considerably accumulate GL, probably to achieve thermal stability. Thirdly, high sunlight intensities seem to influence increased GL accumulation; GL possibly plays a role in cell mechanisms that prevent/mitigate photooxidation. And finally, substantial accumulation of GL detected in the dissolved fraction could be related to the fact that GL do not contain biologically relevant elements, like phosphorus, which makes them an unattractive substrate for enzyme activity. Therefore, substantial portion of CO2 could be removed from the atmosphere in P-limited regions during summer via its capture by plankton and conversion to GL.

Electrical breakdown in water vapor

In this paper investigations of the voltage required to break down water vapor are reported for the region around the Paschen minimum and to the left of it. In spite of numerous applications of discharges in biomedicine, and recent studies of discharges in water and vapor bubbles and discharges with liquid water electrodes, studies of the basic parameters of breakdown are lacking. Paschen curves have been measured by recording voltages and currents in the low-current Townsend regime and extrapolating them to zero current. The minimum electrical breakdown voltage for water vapor was found to be 480 V at a pressure times electrode distance (pd) value of around 0.6 Torr cm (~0.8 Pa m). The present measurements are also interpreted using (and add additional insight into) the developing understanding of relevant atomic and particularly surface processes associated with electrical breakdown.

Genotypic and phenotypic evaluation of Rutilus spp. from Skadar, Ohrid and Prespa Lakes supports revision of endemic as well as taxonomic status of several taxa

One mtDNA gene (cytochrome b), one nuclear DNA fragment, five microsatellites and a suite of morphological characters were evaluated in samples of Rutilus spp. from Skadar, Ohrid and Prespa Lakes. Both genetic and phenotypic data supported two sympatric taxa in Lake Skadar, whereby Prespa and Ohrid Lakes revealed only a single taxon each. One of the taxa from Lake Skadar was similar to samples from Lake Prespa, whereas the second taxon was the most divergent in the data set. The estimated time to the most recent common ancestor of these two sympatric taxa in Lake Skadar was between 125 000 and 500 000 years. The data did not support existing taxonomic schemes for Rutilus in these lakes. This study poses the following working hypothesis: (1) Rutilus prespensis lives both in Lake Prespa and Lake Skadar and therefore is not endemic to Lake Prespa, (2) Rutilus ohridanus lives in Lake Ohrid only and therefore could be considered an endemic if its species status is retained and (3) a third recently described taxon (Rutilus albus) sympatric to R. prespensis lives in Lake Skadar.

AFM imaging of extracellular polymer release by marine diatom Cylindrotheca closterium (Ehrenberg) Reiman & J.C. Lewin

Extracellular polysaccharide production by marine diatoms is a significant route by which photosynthetically produced organic carbon enters the trophic web and may influence the physical environment in the sea. This study highlights the capacity of atomic force microscopy (AFM) for investigating diatom extracellular polysaccharides with a subnanometer resolution. Here we address a ubiquitous marine diatom Cylindrotheca closterium, isolated from the northern Adriatic Sea, and its extracellular polymeric substance (EPS) at a single cell level. We applied a simple procedure for AFM imaging of diatom cells on mica under ambient conditions (in air) to achieve visualization of their EPS with molecular resolution. The EPS represents a web of polysaccharide fibrils with two types of cross-linking: fibrils association forming junction zones and fibril-globule interconnections with globules connecting two or more fibrils. The fibril heights were 0.4-2.6 nm while globules height was in the range of 3-12 nm. Polymer networks of native gel samples from the Northern Adriatic and the network formed by polysaccharides extracted from the C. closterium culture share the same features regarding the fibril heights, pore openings and the mode of fibril association, proving that the macroscopic gel phase in the Northern Adriatic can be formed directly by the self-assembly of diatom released polysaccharide fibrils.

Minimal hepatic encephalopathy in patients with decompensated liver cirrhosis

Minimal hepatic encephalopathy (mHE) is characterized by some minimal unspecific alterations of cerebral functions that can only be detected by neuropsychological or neurophysiological diagnostic tests, which dysfunctions nevertheless interfere with the patient's daily living. Early recognition of these impairments may prevent the progression or delay the development of the disease to overt hepatic encephalopathy. The aim of this study was to diagnose mHE in patients with decompensated liver cirrhosis. The study was conducted in 60 patients aged 40-65, divided into two groups: experimental group and control group. Patients in the experimental group were divided into Child-Pugh groups A, B or C: 53% were classified as Child-Pugh B and 47% as Child-Pugh C. Patients were tested using three neuropsychological tests: Mini Mental Score for quick assessment of cognitive status and two tests specific for mHE changes, Trail Making Test - Part A (TMT-A) and Symbol Digit Test (SDT). Electroencephalography (EEG) was performed in all patients. Limits for completing the test were set by using the formula X(control group) + 2 SD for TMT-A and X(control group) - 2 SD for SDT. All the three tests disclosed statistically significantly different results between the two groups. All patients with cirrhosis had some changes in EEG. Study results showed 80% of cirrhosis patients to have signs of mHE. The Child-Pugh score influenced performance on the neuropsychological tests. SDT more readily identified patients with mHE. Our findings pointed to the frequency of mHE and the importance of early diagnosis in the prevention of mHE progression to overt hepatic encephalopathy.

Antioxidant and antimicrobial activity of some lichen species

The aim of the research is to explore the overall in vitro antioxidant activity, total phenol content, reduction power and antimicrobial activity of the methanol extracts of the lichens Cetraria pinastri, Cladonia digitata, Cladonia fimbriata, Fulgensia fulgens, Ochrolechia parella and Parmelia crinita. The methanol extract of the Cetraria pinastri showed a strong antioxidant activity, whereas the extracts of the species Fulgenesi fulgens, Cladonia fimbriata and Parmelia crinita showed the moderate one and the extract of the species Ochrolechia parella and Cladonia digitata the weak one. The methanol extract of the lichen Cetraria pinastri had the biggest total phenol content (32.9 mg/g of the dry extract). A certain correlation was established between the antioxidant activity and the total phenol content for the researched lichen extracts. The work also explores the antimicrobial activity of the methanol extracts of the mentioned species of lichens against six bacterial and eleven fungi species by the disc-diffusion method and by establishing the minimum inhibitory concentration (MIC). The methanol extracts of the lichens Cetraria pinastri and Parmelia crinita showed the strongest both antibacterial and antifungal activity against most of the tested microorganisms. These researches suggest that the lichens Cetraria prunastri can be used as new sources of the natural antioxidants and the substances with antimicrobial features.

Secondary electron emission of carbonaceous dust particles

In this paper we present measurements of the secondary electron emission yield (gamma) of a carbonaceous dust particle material, which was grown in argon diluted acetylene plasmas. One aim was to reach a better understanding of charging and discharging processes of dust particles in complex plasmas due to secondary electron emission and consequently to try to explain the anomalous behavior of electron density observed in afterglows of pulsed rf plasmas. We compared the results of a simple model and of a Monte Carlo simulation to the previously measured time dependence of the electron density in complex plasma afterglow. It was found that the value of the intrinsic secondary electron yield from the carbonaceous dust material is too low to explain the increase of electron density in the afterglow. It is, however, possible that the electrons charging the particles are weakly attached so that they may be released with high efficiency by ion bombardment due to field induced emission or by other mechanisms.

[Overuse injury syndromes in the shoulder area]

The shoulder is the most movable and the most unstable joint in a human body. The glenohumeral joint is particularly vulnerable because overhead activities put tremendous stress on its static stabilizers (ligamentous labral complex) and the dynamic stabilizers (rotator cuff muscles). Overhead activities may stretch or injure the static stabilizers. Minor aberrations in mechanisms controlling stability have a significant and cumulative effect on the shoulder biomechanics, and increase the risk of injury. Impingement syndrome and glenohumeral instability are predominant injuries affecting the shoulder.

The effect of acute stress and opioid antagonist on the activity of NADPH-P450 reductase in rat Leydig cells

Previous studies indicate that acute immobilization stress (IMO; 2 h) impaired testicular steroidogenesis primarily at the testicular level decreasing the activity of certain steroidogenic enzymes. In the present study unstressed rats as well as IMO rats (2 h) were treated by intratesticular injection of naltrexone methobromide (NMB; peripheral opioid receptor antagonist; 36 microg/testis) or vehicle at the beginning of and at 1 h of the IMO period. In IMO rats the activity of P450c17 was significantly reduced as well as the activity of NADPH-P450 reductase (which catalyzes the transfer of electrons from NADPH to cytochrome P450), while the activity of NADH-b5 reductase was not affected. Present data confirmed previous results that acute IMO reduced testicular P450c17 activity and implicate that decreased activity of NADPH-P450 reductase could be responsible for the inhibition of P450c17 under IMO conditions, while NADH-b5 reductase is probably not involved. NMB treatment antagonized the inhibitory effect of IMO on P450c17 and NADPH-P450 reductase activities. Such results put forward the implication that endogenous opioid peptides are involved in mediating the inhibitory effect of IMO on testicular steroidogenesis, and allow the speculation that NADPH-P450 reductase could be a possible site of such an inhibition.

The involvement of nitric oxide in stress-impaired testicular steroidogenesis

The participation of the nitric oxide (NO) pathway in downregulation of testicular steroidogenesis in normal and stressed rats was investigated both in vivo and in vitro. In Leydig cells from normal animals, isosorbide dinitrate, an NO donor, decreased the human chorionic gonadotropin (CG)-stimulated and progesterone-derived androgen production. Also, the intratesticular injection of a precursor of NO, arginine (10 mg/testis), transiently decreased serum androgen levels and inhibited human CG-stimulated androgen production in acute testicular cultures. These effects were eliminated in rats cotreated with Nomega-nitro-L-arginine methyl ester (L-NAME) (2 X 600 microg/each testis). Acute immobilization stress (2 h) decreased serum androgen levels and inhibited human CG-stimulated androgen production in vitro. These effects were accompanied by a significant increase in nitrite, a stable oxidation product of NO, in testicular cultures. Bilateral intratesticular injection of L-NAME prevented the stress-induced decrease of human CG-stimulated androgen production, and significantly reduced the nitrite levels. These results implicate NO in normal and stress-impaired testicular steroidogenesis.

The effect of opioid antagonists in local regulation of testicular response to acute stress in adult rats

The present study examined the effects of naloxone (N) and naltrexone-methobromide (NMB; an opioid receptor antagonist that does not cross the blood-brain barrier) on testicular steroidogenesis during acute immobilization stress (IMO; 2 h) in adult rats. Unstressed rats as well as IMO rats were treated by unilateral intratesticular injection of N (20 micrograms/testis), NMB (36 micrograms/testis), or vehicle at the beginning of and at 1 h of the IMO period. In IMO rats serum T levels were significantly reduced, while serum luteinizing hormone levels were not affected. N and NMB normalized serum T levels in IMO rats and had no effects in controls. In IMO rats the activities of 3 beta-hydroxysteroid dehydrogenase (HSD) and P450(17 alpha, lyase) were significantly reduced, while the activity of 17 beta-HSD was not affected. N and NMB antagonized the inhibitory effect of IMO on 3 beta-HSD and P450(17 alpha, lyase) but did not alter enzyme activity in freely moving rats. Acute IMO decreased basal and human chorionic gonadotropin-stimulated androgen production by hemitestis preparation, but N (10(-4) M) added directly to the incubation medium blocked the decrease and had no effect on testes from freely moving control rats. These results support the conclusion that endogenous opioid peptides are potentially important paracrine regulators of testicular steroidogenesis under stress conditions.

Effects of acute and chronic immobilization stress on rat Leydig cell steroidogenesis

In rats, acute immobilization (IMO) stress (2 h) induced a fall in the serum androgen concentrations (T+DHT) without detectable changes in serum luteinizing hormone (LH) values. In vitro studies, using a suspension of Leydig cells from adult rat testis, demonstrated that acute stress inhibited conversion of progesterone (P) or 17hydroxyprogesterone (17OHP) to T while conversion of androstendione (delta 4 A) was not affected. Acute IMO reduced activity of 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) and decreased basal and hCG-stimulated progesterone and androgen production. Chronic IMO stress (2 h daily for 10 days) induced a decrease in serum androgen level with decline in serum LH values. In vitro, hCG-stimulated progesterone and androgen production by suspension of Leydig cells, as well as conversion of P and 17OHP to T were not significantly altered. Our data demonstrates that acute IMO stress impaired testicular steroidogenesis primarily at the testicular level (decreasing the activity of certain enzymes), while chronic IMO stress exerts the effect mainly on the hypothalamic-pituitary axis; reduced serum LH levels elicit a decrease in serum androgen levels.

[Diagnostic and prognostic significance of long latency reflexes, somatosensory evoked potentials and the blink reflex in cerebral ischemia]

In order to determine diagnostic and prognostic value of long latency reflexes, blink reflex and somatosensory evoked potentials in patients with ischemic brain disease (IBD), examinations were done in 32 patients of both sexes with IBD, average age 44-76 years. First examinations were performed within first week of the onset of IBD and in majority of patients repeated after 3 and 6 months. Changes of electrophysiological characteristics compared with the degree of IBD, clinical presentation, localization, extent of infarction zone (measured by CT) and functional recovery where analyzed. Electrophysiological changes were predominantly associated with amplitude of physiological response and were in correlation with the degree of IBD, localization and the extent of infarction zone. Latencies were prolonged only in case of subcortical ischemic lesions. Correlation between functional recovery and electrophysiological changes was present only within the structures responsible for certain components of electrophysiological responses and localization of ischemic lesion. In conclusion, electrophysiological examinations are of high diagnostic and predictive value in IBD.

[Treatment of acute migraine attacks]

Considering that migraine patients ask for the physician's help in outpatient clinics and hospitals due to the acute attacks dominated by headaches, the latest research in pathophysiology and pharmacotherapy of migraine, directed the aim of this research to investigate the efficiency of dihydroergotamine in the treatment of the acute attacks of migraine headaches and to define a treatment program of the acute migraine headaches for the out patient and in patient conditions. The investigations were performed in 34 patients of the middle age and younger, of both sexes, with the established clinical diagnosis of a common migraine, with no history of coronary disease, ischemic brain disease, kidney and hepatic deficiency, and who were not for different reasons, Under the prophylactic therapy. Patients were randomly divided into two equal groups. The first group was treated i.m. with dihydroergotamine (1 mg) in combination with metoclopramide (10 mg). In case of insufficient effect the dose was repeated after one and eight hours after the first dose. The second group was treated with diclofenac (75 mg) and metoclopramide (10 mg), using the same pattern. The results investigation showed the significantly better effect of dihydroergotamine regarding the onset and the intensity of the positive effect. It was concluded that in case of acute attacks of migraine headaches in younger patients with no history of coronary disease, ischemic brain disease, kidney and hepatic deficiency, dihydroergotamine with metoclopramide administered i.m. could be used as a therapy of choice in all treatment conditions.

[Sensitivity of atherosclerosis indices in patients with ischemic brain disease]

Epidemiological studies suggest that dyslipoproteinemias and hyperlipoproteinemias present one of the most important risk factors in the development of atherosclerosis and its complications. The aim of this study was to find out which of the lipid status disorders in patients with ischemic brain disease was the most important risk factor in the development of cerebral atherosclerosis. Patients with ischemic brain disease were examined in the acute and subacute phase. Total blood cholesterol, low density lipoproteins (LDL) and high density lipoproteins (HDL) as well as of apolipoproteins A1 and B were determined. Correlations (atherogenic indices) of some lipid components with the severity of clinical course and echo-angiographic finding were determined. It was concluded that the highest correlation with the cerebral atherosclerosis severity degree existed with the level of apoA1 and apoB apolipoproteins, followed by correlation of LDL and HDL cholesterol, and the lowest correlation was found between HDL and the total cholesterol. Accordingly, apolipoproteins, i.e., apoA1/apoB indices are the most sensitive markers of the risk for atherogenesis.

[Sensitivity of electrophysiologic tests in the diagnosis of carpal tunnel syndrome]

According to anatomic characteristics of median nerve branches and pathophysiological basis of the carpal tunnel syndrome (CTS), significant difference in sensitivity of some electrophysiological parameters in the diagnosis of this syndrome was presumed. The aim of this study was to analyze characteristics of some abnormalities of electrophysiological parameters and to determine their frequency in the carpal tunnel syndrome. Investigation was performed on 34 patients with the carpal tunnel syndrome and 30 neurologically healthy subjects. EMGs of the tenar muscles, terminal latency parameters for the median nerve and sensory conductivity of the median nerve branches including cutaneous palmar branch and ulnar nerve branches of the ring finger were examined and analyzed. Results have shown that abnormalities were most frequently found in sensory conductivity parameters for median nerve branch of the ring finger. Significant difference between sensory conductivity parameters for cutaneous palmar branch and median nerve branch of the thumb was also found. These results were discussed in terms of current knowledge about anatomic characteristics of the hand innervation and pathophysiology of the carpal tunnel syndrome. It was concluded that the most frequent physiological findings could be used as a highly sensitive test for reliable and early diagnosis of CTS.

[The effect of therapeutic plasma exchange on serum immunoglobulins and the clinical course of myasthenia gravis]

Fourteen patients with clinically, pharmacologically and electrophysiologically confirmed myasthenia gravis in which therapeutic plasma exchange was performed were analyzed. Condition of these patients was assessed before and after the plasma exchange using the Besinger score. The serum immunoglobulin levels were also determined by ELISA-test before and after the plasma exchange. Findings have shown that clinical improvement was highly significant. Changes in IgM and IgA levels were significant, but not in IG and IgE. Significant correlation neither between the level of each separate immunoglobulin and clinical condition of the patient, nor between the change in the level of each separate immunoglobulin and changed clinical course was found after the series of plasma exchange. Cumulative effect of all immunoglobulins was not observed due to differences in their physical and chemical properties. Absence of significant statistical correlation between the level of each immunoglobulin and clinical condition of the patient as well as between the level changes of each separate immunoglobulin and changed clinical condition after series of plasma exchange could be explained by cumulative effect of all immunoglobulins, but probably also by the presence of some other, circulating factor not belonging to the class of immunoglobulins and associated with the development of myasthenic weakness.

In vivo effect of prothymosin-alpha 1 on humoral and cell-mediated immune responses in the young rat

There is a large body of evidence for the role of thymosin peptides in immunogenesis and immunity. In this paper we report on the influence of prothymosin alpha 1 (ProT-alpha 1), a hormone-like peptide derived from the calf thymus, on humoral and cellular immune reactions in the rat. Young adults received intraperitoneal injections of ProT-alpha 1 in the periods before and after immunization with cellular and soluble antigens. ProT-alpha-treatment produced a dose-dependent increase of both humoral and cell-mediated immune responses. The thymus weight increased but not that of spleen. Treatment of nonimmunized rats with this polypeptide significantly elevated the number of CD4+ and decreased the number of CD8+ cells in the peripheral blood. The results suggest a potent immunostimulatory activity of ProT-alpha 1 and imply direct action of this polypeptide on T lymphocytes.

Changes of experimental allergic encephalomyelitis by methionine-enkephalin injected into lateral ventricles of the rat brain

Our previous investigations have shown that the opioid peptide methionine-enkephalin (Met-Enk) modulates in vivo a variety of humoral and cell-mediated immune performances. In this study, rats bearing polyethylene cannulae permanently inserted into the lateral ventricles of the brain were used. Experimental allergic encephalomyelitis (EAE) was induced with guinea pig spinal cord in complete Freund's adjuvant injected into the left hind foot pad. The following groups of cannulated rats were tested: nontreated with Met-Enk or saline, intracerebroventricularly (i.c.v.) injected with saline, and i.c.v. treated with low (1 microgram/kg) dose of Met-Enk and high (1 mg/kg) dose of Met-Enk. Intact noncannulated rats sensitized for EAE served as an additional control. The results showed that i.c.v. treatment with 1 microgram/kg of Met-Enk significantly increased the incidence and severity of EAE. In contrast, injections of 1 mg/kg of Met-Enk produced a moderate decline of clinical EAE, but marked diminution of inflammatory lesions in the brain. Interestingly, histopathology of EAE was more pronounced in control rats treated i.c.v. with saline. On the other hand, control cannulated rats noninjected with saline exhibited a striking decrease of neurological and histopathological signs of the disease, thus indicating a suppressive effect of stress (surgical procedure) on EAE. In conclusion, the present study showing the central effect of Met-Enk on EAE when peptide was applied in the cerebral cavity, and earlier studies which revealed the peripheral effect on EAE when Met-Enk was administered intraperitoneally, suggests that Met-Enk exerts its immunomodulatory action both centrally and peripherally.

Immunostimulatory activity of prothymosin-alpha in senescence

In this study we evaluated the immunorestorative activity of prothymosin-alpha (ProT-alpha) in senescence. Aged rats were repeatedly injected with ProT-alpha after antigen challenge. Both humoral and cell-mediated immune reactions were tested. The results show that ProT-alpha exerted a marked immunopotentiating effect in aged rats. Moreover, ProT-alpha induced enhancement of PFC response, and skin hypersensitivity reactions were more pronounced in senescent rats than in young adult controls. ProT-alpha treatment increased thymus and spleen weights in aged rats, and induced qualitative and quantitative improvements of the cellular make-up of the thymus and thymus-dependent areas of the spleen. The results imply that "restoring" thymus endocrine function by exogenous administration of ProT-alpha may improve immune system homeostasis in senescence.

Enkephalinase-inhibitors modulate immune responses

Exogenous opioid peptides, and enkephalins in particular, modulate a variety of immune performances in vivo and in vitro. In this study, the immunomodulatory role of endogenous opioids was investigated by means of central and peripheral administration of four peptidase inhibitors in the rat. Animals sensitized with sheep red blood cells (SRBC) were daily treated intraperitoneally (i.p.) with 0.2 mg/kg or 1 mg/kg of each inhibitor, or intracerebroventricularly (i.c.v.) with 0.02 mg/kg and 0.2 mg/kg of bestatin, des-tyrosine-methionine-enkephalin, (Des-Tyr1)Met-Enk; and actinonin, and 0.005 and 0.5 mg/kg of N-Carboxymethyl-phenilalanine-leucine,(N-C)Phe-Leu. Controls were injected i.p. and i.c.v. with saline. The results revealed that in animals treated i.p. with 0.2 mg/kg of bestatin and (N-C)Phe-Leu potentiated the plaque-forming cell (PFC) response and hemagglutinin production. In contrast, these immune responses were suppressed by 1 mg/kg. On the other hand, i.p. doses of 0.2 and 1 mg/kg of actinonin and (Des-Tyr1)Met-Enk potentiated humoral immune responses. When given i.c.v., all of the inhibitors used exerted clear dose-dependent immunomodulatory effects, i.e. increase in the PFC response and hemagglutinin production when given at lower doses (0.005-0.02 mg/kg), and decrease when injected with higher doses (0.2-0.5 mg/kg). These effects of enkephalin-related peptidase inhibitors, applied i.p. and i.c.v., suggest the involvement of endogenous enkephalins in immune mechanisms.

Magnetic fields, brain and immunity: effect on humoral and cell-mediated immune responses

Magnetic fields (MF) can influence biological systems in a wide range of animal species and humans. We report here on the influence of static MF, locally applied to the brain area, on immune system performances in the rat. In the first series of experiments two AKMA micromagnets (M) with the influx density of 600 Gauss were bilaterally implanted (with "N" polarity facing the cranial bones) and fixed to the skull posterior to the fronto-parietal suture (parietal brain exposure). Rats implanted with iron beads (I) and sham-operated (SO) rats served as controls. Animals were exposed to MF or I during different periods of time before and after immunization with several soluble or cellular antigens. We report here on the in vivo immunoregulating effects of centrally applied MF on plaque-forming cell (PFC) response, local hypersensitivity skin reactions and experimental allergic encephalomyelitis. The selective influence of MF applied to different brain regions on PFC response was evaluated, as well. For this purpose, two M were bilaterally implanted in the area of (a) frontal, (b) parietal and (c) occipital brain regions. Rats were under the influence of MF for 20 days before and 4 days after immunization with sheep red blood cells. Groups of nonimmunized rats were exposed for 14, 24 and 34 days to parietally implanted M or I, and the number of peripheral blood CD4+ and CD8+ cells determined by mouse anti-rat W3/25 and MRC OX 8 monoclonal antibodies. The results show an overall in vivo immunopotentiation of humoral and cell-mediated immune responses in rats exposed to MF. Furthermore, these immunomodulating effects of centrally applied MF depend on at least two basic parameters, time of exposure and brain region exposed. The highest immune performance was obtained after exposure of the occipital brain region for a total period of 24 days. The results provide further evidence of the complex interrelationship between the environment, the central nervous system and the immune system.

Enkephalin-induced stimulation of humoral and cellular immune reactions in aged rats

Twenty-month-old Wistar rats received intraperitoneal injections of the opioid pentapeptide, methionine-enkephalin (Met-Enk) in periods before and after immunization with cellular and soluble antigens. Animals were treated with 0.2 mg of Met-Enk/kg b.w., a dose previously found to increase immune capacity in young adult rats. Saline-treated 20-month-old, and Met-Enk-treated rats and saline-treated 8-week-old controls were set up for each experimental group. Immune performance was evaluated by plaque-forming cell response, antibody production and various immunoinflammatory reactions. At autopsy, thymus and spleen were weighed and processed for histological examination. The results showed that 0.2 mg dose of Met-Enk produced significant enhancement of both humoral and cellular immune responses in senescent rats. Methionine-enkephalin treatment also induced a significant increase in thymus and spleen weights in these animals. Analysis of the cellular make up of these organs revealed the enlargement of cortical and medullary areas, and pronounced pyroninophilia in the subcortical zone of the thymus and thymus-dependent areas of the spleen. The results suggest that Met-Enk exerts an immunorestorative activity in aged animals, and that changes in the opioid system may play an important role in the maintenance of immune functions during senescence.