[HIV preexposure prophylaxis]

The pre-exposure chemoprophylaxis (PrEP) is an experimental approach to HIV prevention. The use of antiretroviral drugs has been shown to be effective in prevention HSIV infection in animals. The results from ongoing clinical PrEP trials have demonstrated that antiretrovirals were able to reduce HIV incidence in women and men. The CAPRISA-004 study demonstrated that 1% TDF gel applied intravaginally decreased the risk of HIV infection among heterosexual women in South Africa. The largest global trial iPr Ex conducted in men who have sex with men (MSM), has demonstrated that chemoprophylaxis with daily oral TDF/FTC was 44% effective in protecting against HIV transmission. Following the results of the iPrEx study, the US CDC issued the interim guidance regarding the use of oral PrEP among MSM. Currently more then 20.000 people will be enrolled in studies with oral or topical antiretroviral agents as pre-exposure chemoprophylaxis.

[HIV infection in women in childbearing age]

HIV infected women compromise about half of all people living with HIV worldwide. Since HIV is frequently sexually transmitted it follows that women who are seropositive are likely to acquire other sexually transmitted diseases. The gynecologic infections led enhance HIV replication and increased transmission of virus. The presence of STD in known to increase of both acquiring and transmitting HIV. The risk of MTCT can be reduced to below 1% by interventions that include antiretroviral prophylaxis given to women during pregnancy and labour and to the infant in the first weeks of life.

[Tuberculosis among HIV infected patients]

The aim of study was to determine clinical presentation and outcome of tuberculosis among patients infected with human immunodeficiency virus type 1 (HIV-1). During 2001-2006, 36 cases of tuberculosis (TB) was recognized in 33 patients infected with HIV. The majority of patients were men infected with HIV in through intravenous drug using and had a CD4 cell count <200cells/microl at the time of TB diagnosis. The most frequent form of TB was pulmonary localization and lymphadenitis as extrapulmonary localization. Meningitis was recognized in two cases. The diagnosis was confirmed by positive culture for mycobacteria and PCR in 34/36 patients. Mycobacterial smears were positive in 2/36 cases, the skin test reaction with nodule >5mm was positive in 60% cases. Immune reconstruction syndrome was recognized in 4 patients.

[Morphological liver changes of chronic hepatitis C in antiretroviral-naive HIV-infected patients]

The aim of the study was evaluation of morphological exponents of chronic hepatitis C in naive HIV/HCV co-infected patients.

MATERIAL AND METHODS

Investigation were performed in 61 patients with chronic hepatitis C, 21 HIV co-infected. HIV-HCV co-infected patients were included to group I. There were 7 females and 14 males (mean age 31.5 years). In group II there were 40 patients with chronic hepatitis C HIV-seronegatives. There were 22 females and 18 males (mean age 40.1 years). In all patients medical history, physical examination, some laboratory tests (ALT activity, HCV viral load) and histological examination of liver biopsy specimens were performed. In patients from group I HIV viral load and CD4 count were assessed.

RESULTS

Among HCV infected (group II) higher biochemical activity of the disease and more intense inflammatory changes and fibrosis in the liver were detected. In group HIV/HCV co-infected 2-times higher values of HCV viral load were detected. There were no connections with morphological liver picture and HCV viral load in these patients. There were no connections between the grade of immunodeficiency and advancing of morphological changes in the liver. So grading as staging were similar, independent on lymphocyte CD4 count.

CONCLUSION

In the light of performed investigations it was revealed that HIV not accelerate the natural history of chronic hepatitis C. The grade of immunodeficiency measured by CD4 count seems to no influence on advancing of morphological changes in the liver in naive patients.

[Serum IL-2 and sIL-2R concentration in children with chronic hepatitis B]

The aim of the study was evaluation of serum IL-2 and sIL-2R concentration in children with chronic hepatitis B without previous treatment.

MATERIAL AND METHODS

Investigations were performed on sera from 27 children, 13 HBsAg and HBeAg positive (group I) and 14 HBsAg positive, HBeAg negative, anti-HBe positive (group II). Serum IL-2 and sIL-2R concentrations were detected with ELISA method.

RESULTS

In all examined children serum IL-2 concentrations were decreased. The mean values of sIL-2R in group I was 4,40 (from 1,78 to 15,74) and in group II was 2,60 ( from 1,59 to 4,81) ng/ ml and were statistically significant higher in HBeAg positive children (group I, p < 0.005). The mean ALT activity in this group of children was increased (mean 74 U/I) . The positive correlation between sIL-2R and ALT activity was observed in group I.

CONCLUSIONS

In children with chronic hepatitis B a deficiency of Th1 mediated immunological response was observed. HBeAg/anti-HBe seroconversion seems to change the IL-2/sIL-2R balance.

[HIV and HCV infections--clinical implications]

Coexisting HIV and HCV infection involves approx. 10 million people in the world. It is most common in drug addicts taking drug injections as well as in haemophiliacs. In the research we have confronted the existing views on natural history progression in hepatitis C in HIV infected, with our own study. The existing recommendations for hepatitis C treatment have also been presented. It was pointed out that there is a possibility of interaction between the drugs applied in the treatment and the antiretrovirus therapy and what is connected with it, the possibility of potentially adverse actions. It was also shown that early treatment of hepatitis C in HIV infected slows down the progress of liver fibrosis, prevents liver failure, improves HA-Art tolerance, increases immunological reconstruction and improves the quality of the patients' lives.

Muscarinic cholinergic receptors of rat lymphocytes: effect of antigen stimulation and local brain lesion

Expression of muscarinic cholinergic receptors (m-AchR) on thymocytes and lymphocytes supports a hypothesis of direct interaction between autonomic innervation and the immune system. Using a muscarinic antagonist, [3H]quinuclidinyl benzilate ([3H]QNB), we revealed different characteristics of m-AchR expression in lymphocytes isolated from the spleen, peripheral blood or thymus of Wistar rats. To further explore the mechanisms controlling m-AchR expression in lymphocytes we have addressed two questions: (i) whether local brain lesions will affect [3H]QNB binding activity of lymphocytes and (ii) whether different antigens will alter m-AchR expression in lymphocytes. We report here that electrolytic lesions of the area hypothalamica anterior resulted in a significant increase in [3H]QNB-specific binding in thymocytes 7 days after neurosurgery. In contrast, local lesions of other hypothalamic structures (area preoptica medialis, area hypothalamica posterior) or sensomotor cortex did not affect m-AchR expression in thymocytes. No apparent changes of [3H]QNB-binding activity were found in lymphocytes isolated from rat spleen or peripheral blood after operation. Both T-cell-dependent (sheep red blood cells) and T-cell-independent (Vi antigen of Salmonella typhi) antigens induced a significant increase in [3H]QNB-specific binding in spleen lymphocytes while [3H]QNB-binding activity of peripheral blood lymphocytes did not change. A different pattern of lymphocyte m-AchR expression found in various lymphoid tissues after immunization or brain lesions suggests a local involvement of cholinergic mechanisms in neuroimmune interaction.

Muscarinic antagonist binding to intact rat thymocytes

The presence and properties of muscarinic receptors on intact rat thymocytes have been studied by the use of the muscarinic antagonists [3H]-3-quinuclidinyl benzilate (3H-QNB), [3H]-4-N-methylpiperidinyl benzilate ([3H]-NMBP) and [3H]-N-methylscopolamine (3H-NMS). The course of binding of 3H-QNB reveals a maximum at 5 min, and shows a subsequent decrease of bound radioactivity, suggesting internalization of the receptor 3H-3-QNB complex. This phenomenon has also been studied by the use of another muscarinic antagonist, 3H-NMPB, which has a faster on and off rate than 3H-QNB, and which may be rapidly displaced by an excess of unlabeled muscarinic antagonist, atropine. Bound 3H-NMPB is highly susceptible to atropine displacement only within the first two minutes of incubation with thymocytes at 37 degrees C. The kinetics of binding of the less lipophilic muscarinic antagonist 3H-NMS to thymocytes, show no maximum as a function of incubation time and 3H-NMS is susceptible to displacement by atropine up to 30 min incubation time with the thymocytes. These data suggest that binding of lipophilic benzilate type antagonists (3H-QNB and 3H-NMPB) may be followed by internalization and/or isomerization of the receptor-benzilate antagnist complex while the 3H-NMS-receptor complex is not subject to these processes.

Expression of muscarinic cholinergic receptors during T cell maturation in the thymus

Thymocytes at various stages of their ontogeny have been studied in relation to their ability to bind [3H]quinuclidinyl benzilate [( 3H]QNB), a specific radioligand of the muscarinic cholinergic receptors. [3H]QNB-specific binding to thymocytes from 15-19-day fetal, newborn and adult thymuses of mice and rats was compared and correlated. Our experiments showed that the kinetics of [3H]QNB binding to thymocytes at 37 degrees C was similar to that of the lymph node lymphocytes (LNL) with maximum after 5 min of incubation and subsequent decrease to 10% of the maximum after 90 min of incubation. Maximal binding for the entire thymocyte population was twice lower than for the cortisone-resistant thymocytes (CRT) or for LNL. Binding of [3H]QNB carried out at 4 degrees C resulted in disappearance of the maximum, but did not alter the difference between CRT and entire thymocyte population. Depletion of CRT detectable [3H]QNB-specific binding to thymocytes until 18th day of gestation but the maximal binding increased up to 20% at the day 19 and reached 90% of adult level on the third day after birth. Moreover, carbamylcholine (a muscarinic agonist) treatment in vivo induced a significant decrease in [3H]QNB binding to the thymocytes. We thus suggest that a subpopulation of thymocytes bearing muscarinic receptors in the periphery acquired these receptors in the thymus as one of the last steps of their maturation. We cannot exclude the possibility that cholinergic stimulation might trigger these lymphocytes to leave the thymus.

Muscarinic receptors of rat lymphocytes--differences in young and old animals

Muscarinic receptors were studied on lymphocytes from young and old Wistar rats. Binding studies were performed by the use of [3H]-QNB, a specific muscarinic antagonist. Some differences between these two groups were observed. Maximal binding of [3H]-QNB and half time of the maximal binding is lower for lymphocytes of old rats [3H]-QNB receptor complexes could not be found in the supernatants derived from lymphocytes of old animals. Higher ability to loose or hide the muscarinic receptors was also observed in this group of rats. All these observations could reflect a more effective degradation, as well as a lower level of muscarinic receptors exposed on lymphocytes from old animals.

Muscarinic acetylcholine receptors of rat lymphocytes

The muscarinic acetylcholine receptors on rat lymphocytes were determined by [3H]quinuclidinyl benzilate binding studies. Binding of [3H]quinuclidinyl benzilate is rapid (half saturation occurred within 120 s) and highly specific. Muscarinic receptors reveal high lability. The number of receptors on plasma membrane depends on time of incubation as well as on composition of incubation medium. Lymphocytes incubated in nutrient-deficient media lose their surface receptors; enrichment of the medium causes reappearance of the receptors. Appearance of [3H]quinuclidinyl benzilate-binding sites in the incubation medium was under conditions in which binding to lymphocytes was decreased. It is concluded that the number of plasma membrane receptors on rat lymphocytes represents the dynamic steady state in which newly synthesized and degraded receptors are balanced.

Cultured beating myocytes from neonatal rat heart as a model for the study of muscarinic cholinergic receptors

Neonatal rat heart myocytes were isolated by digestion of the heart tissue with trypsin. After separation the cells were transferred to plastic cluster dishes where they formed a monolayer culture. After 72 hours in culture the myocytes showed a synchronous contraction and renovation of their membrane structures. Studies of muscarinic cholinergic receptors were carried out using (3H)-Quinuclidinyl benzilate directly on cells attached to the bottom of the dish. The presence of a specific muscarinic receptor on cultured beating myocytes was confirmed.

Acetylcholine receptors of rat lymphocytes

The conditions of the binding of acetylcholine have been studied in lymphocytes isolated from rat peripheral lymph nodes. Acetylcholine appeared to penetrate the lymphocyte membrane. We have confirmed the presence of muscarinic receptors, which, however, are not involved in transport of acetylcholine through the membrane. The receptors of the nicotine type on lymphocytes are demonstrated by the decrease of acetylcholine binding in the presence of a specific antagonist, tubocurarine. These nicotinic receptors may be involved in acetylcholine transport into the cells.