Impact of chorioamnionitis on the development of human fetal lung: an immunohistochemical study

PURPOSE

Current studies suggest that changes of chorioamnionitis are associated with the appearance of bronchial-associated lymphoid tissue (BALT), during fetal development. The aim of this study was to examine and analyse apart from the appearance of BALT, the expression of structural proteins in the lung parenchyma during gestation.

MATERIALS AND METHODS

A series of 149 paraffin-embedded human fetal lung specimens at the second trimester of development were examined by immuunohistochemistry using the monoclonal antibodies CD20, CD3, Tenascin-C, Vimentin, and Fibronectin.

RESULTS

The results of this study showed that (1) BALT does not develop in fetal period and (2) BALT which develops during fetal period is probably in response to antigenic stimulation where in the present cases occurs to be changes of chorioamnionitis which decreased the expression of filaments proteins in the intermediate cells of lung parenchyma in comparison with the normal ones.

CONCLUSION

The expressions' pattern of intermediate filaments proteins in the lung parenchyma can be modified by the presence of chorioamnionitis in the fetal membranes.

The cytogenetic action of ifosfamide, mesna, and their combination on peripheral rabbit lymphocytes: an in vivo/in vitro cytogenetic study

Ifosfamide (IFO) is an alkylating nitrogen mustard, administrated as an antineoplasmic agent. It is characterized by its intense urotoxic action, leading to hemorrhagic cystitis. This side effect of IFO raises the requirement for the co-administration with sodium 2-sulfanylethanesulfonate (Mesna) aiming to avoid or minimize this effect. IFO and Mesna were administrated separately on rabbit's lymphocytes in vivo, which were later developed in vitro. Cytogenetic markers for sister chromatid exchanges (SCEs), proliferation rate index (PRI) and Mitotic Index were recorded. Mesna's action, in conjunction with IFO reduces the frequency of SCEs, in comparison with the SCEs recordings obtained when IFO is administered alone. In addition to this, when high concentrations of Mesna were administered alone significant reductions of the PRI were noted, than with IFO acting at the same concentration on the lymphocytes. Mesna significantly reduces IFO's genotoxicity, while when administered in high concentrations it acts in an inhibitory fashion on the cytostatic action of the drug.

Distribution of ABO and Rh blood groups in Greece: an update

The aim of this study was to investigate and evaluate the frequency of the antigens classifying the ABO and Rh blood groups in the Greek population. In this study the 3.5% were first generation immigrants with both their parents immigrants from countries of the USSR, while 1.2% had only one immigrant parent, while the other one was Greek. We compared the frequency of distribution of blood groups ABO and Rh to previous studies conducted at a time before Greece became destination for refugees and immigrants from East and Northeast countries. Blood samples were collected from first year medical students. The frequency of distribution of the ABO and Rh blood groups was slightly differentiated in comparison to previous relevant studies. Significant increase was recorded with respect to the emergence of blood group B in the population investigated, and a considerable reduction was noted in blood group O. In reference to the remaining blood groups, no statistically significant difference was documented. The genetic pool and the genetic inventory of the population residing in Greece have been modified during the last years potentially due to the first generation immigrants. The results of this study could contribute significantly to the National Health System in aiding the prediction of percussions of certain diseases related to blood groups, as well as the requirement for certain blood groups within the blood donation program.

Cytokine profile in cases with premature elevation of progesterone serum concentrations during ovarian stimulation

The aim of this study was to investigate the concentrations of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), leptin, tumor necrosis factor-alpha, interleukin (IL)-1beta and IL-6, in cycles with a premature rise of serum progesterone. 25 intracytoplasmic sperm injection (ICSI) cycles with (Group 1) and 25 ICSI cycles without a premature progesterone elevation (Group 2) were included. The cut-off value of serum progesterone on the day of human chorionic gonadotropin (hCG) administration was 0.9 ng/ml. The indication for ICSI was male factor infertility exclusively. On the day of hCG injection, serum IL-6, VEGF and bFGF were significantly higher in Group 1 (7.7+/-24.5 pg/ml, 290.2+/-161.4 pg/ml and 15.7+/-8.2 ng/ml respectively) than in Group 2 (1.7+/-0.7 pg/ml, 175.2+/-92.1 pg/ml, and 9+/-1.6 ng/ml respectively). On the day of follicular puncture, serum cytokine concentrations were similar in the two groups. IL-6 intrafollicular concentrations were higher in Group 1 (14.7+/-20.7 pg/ml) than in Group 2 (9+/-9.3 pg/ml, p=0.031). There were no differences regarding the ICSI outcome. Patients with serum progesterone above 0.9 ng/ml, have elevated serum concentrations of IL-6, VEGF, and bFGF, as well as elevated intrafollicular concentrations of IL-6. The outcome of ICSI cycles is not associated with premature elevation of progesterone when the cut-off value is set at 0.9 ng/ml.

Modulatory role of adenosine and its receptors in epilepsy: possible therapeutic approaches

Adenosine is considered to be the brain's endogenous anticonvulsant as many studies have showed and it is responsible for seizure arrest and postictal refractoriness. Alterations in the adenosinergic system (adenosine and its receptors) have been referred by many previous studies indicating that deficiencies or modifications in the function of this purinergic system may contribute to epileptogenesis. Due to this emerging implication of adenosine in the managing of seizures, a new field of adenosine-based therapies has been introduced including adenosine itself, adenosine receptor agonists and antagonists and adenosine kinase inhibitors. The method with the least side effects (heart rate, blood pressure, temperature or even sedation) is being quested including intracerebral implantation of adenosine releasing cells or devices.

The role of basic-fibroblast growth factor (b-FGF) in cyclosporine-induced nephrotoxicity

BACKGROUND

The effect of the b-fibroblast growth factor (b-FGF) on cyclosporine A (CsA)-induced nephrotoxicity in the rat kidney was investigated.

MATERIALS AND METHODS

The rats were divided into six groups: A (control), B (b-FGF-treated), C, D: (CsA-treated and sacrificed on days 14 or 21), E, F (Cs A- and b-FGF- treated and sacrificed on days 14 or 21). The antibody mouse anti-rat CD31 was used to evaluate the kidney vessels present in histological preparations.

RESULTS

The kidney vessels in group B were increased in comparison with the control group (p<0.05). Reduction of kidney vessels in groups C and D (p<0.05) in comparison with the controls was observed, while in groups E and F they were increased when compared to group C (p<0.05) and D (p<0.05), respectively.

CONCLUSION

The angiogenic role of b-FGF was confirmed in normal rats and a possible "protective" role of b-FGF was shown in rat kidney with CsA-induced nephrotoxicity.

Multiantibiotic resistance of gram-negative bacteria isolated from drinking water samples in southwest Greece

In this study we monitored the sensitivity of 239 gram-negative bacteria (of fecal and non-fecal origin), isolated from the old drinking water distribution network of Patras in southwestern Greece, to 20 antibiotic agents. Two methods were used to find the multiresistant bacteria (bacteria resistant to two or more antibiotics): the diffusion disk method and a serial dilution method. The gram-negative bacteria tested were: Enterobacteriaceae (62), Pseudomonas (145), Vibrionaceae (24), Chromobacter (3), Acinetobacter (2) and others (4). The highest levels of antibiotic resistance were obtained for cephalothin (86.7%), ampicillin (77.5%) and carbenicillin (71%) followed by cefoxitin (55.4%) and cefuroxime (51.2%). Intermediate resistance levels were found for ticarcillin (31.3%), ceftizoxime (31.2%), chloramphenicol (30.3%), and cefotetan (25.2%). Low resistance levels were obtained for cefotaxime (17.9%), sulfisoxazole (15.2%), ceftriaxone (12.5%), tetracycline (11.9%), trimethoprim/sulfamethoxazole (7.4%) and piperacillin (2.4%). Overall 91.3% of the gram-negative bacteria isolated from drinking water were multiresistant. No resistant strains were found to quinolones, aminoglycosides, imipenem, aztreonam, ceftazidime or cefoperazone. The high antibiotic resistance rate of the isolated microorganisms from the Patras drinking water supply is discussed.

Age-dependent changes in adenosine A1 receptor and uptake site binding in the mouse brain: an autoradiographic study

Ageing is a multifactorial, inevitable event of life span, which affects neurotransmission in the CNS. Since adenosine is a major neuromodulator of the synaptic activity, it was of interest to investigate the possible modification of the adenosinergic system in the brain during ageing. Using "in vitro" quantitative autoradiography and the radioactive ligands [(3)H]Cyclohexyladenosine and [(3)H]Nitrobenzylthioinosine, we have studied the distribution of A1 adenosine receptors and adenosine uptake sites in the aged mice (26 months) compared to the young ones (3 months). Our results showed a widespread reduction in A1 receptor binding in the aged animals, which was brain area-specific, occurring in areas where adenosine plays a significant neuromodulatory role such as the hippocampus, cortex, basal ganglia, and thalamus. Interestingly, the significant reduction in NBI-sensitive adenosine uptake sites was restricted to few areas of the aged brain, mainly in thalamic nuclei. Since the alterations in the density of A1 receptors and adenosine uptake sites showed no regional correlation and since no significant changes in either neuronal or glial cell number are observed, at least in hippocampus and cortex in this mouse strain during ageing, our findings could be explained by a selective age-dependent reduction of these adenosinergic components rather than by a general neuronal cell degeneration. As adenosine depresses electrical activity in hippocampus, a downregulation of adenosinergic function could probably be related to enhanced excitability seen in hippocampal neurons of the CA1 subregion and dentate gyrus of aged animals.

Time development and regional distribution of [3H]nitrobenzylthioinosine adenosine uptake site binding in the mouse brain after acute Pentylenetetrazol-induced seizures

Adenosine has been shown to play a significant role as a modulator of neuronal activity in convulsion disorders, acting as an endogenous anticonvulsant agent. In the present study, we have investigated in mice the effect of acute tonic-clonic seizures induced by a single Pentylenetetrazol (PTZ)-injection (a) on the time development of adenosine uptake site binding after seizures in membranes of hippocampus, cortex, cerebellum, and striatum, and (b) on the regional distribution of adenosine uptake sites in the mouse brain by using "in vitro" quantitative autoradiography. As radioligand, the specific adenosine uptake blocker [3H]N-9-nitrobenzylthioinosine ([3H]NBI) was used. Acute seizures induced a rapid significant increase in [3H]NBI uptake site binding in hippocampus and cerebellum within 5 min, in cortex within 10 min after seizures, which reached a maximum level at 1 hr and reversed to control levels in about 150 min after seizures. On the contrary, in striatum a significant decrease of [3H]NBI uptake site binding was observed within 10 min after seizures, which reached its maximum at 1 hr and reversed to control levels at 150 min after seizures. With this single exception of striatum the "in vitro" quantitative autoradiography revealed a rather widespread upregulation of [3H]NBI uptake site density in the mouse brain, which was specifically enhanced in certain areas known to mediate seizure activity, such as hippocampus, specific thalamic nuclei, temporal cortex, and substantia nigra. The pattern of increases in [3H]NBI uptake site binding as they develop after acute seizures correlates well in time with the rapid enhancement of endogenous adenosine concentration released during epileptic activity. Since extracellular adenosine levels seem to be regulated by a rapid reuptake system, it seems likely that in our study, the [3H]NBI adenosine uptake system is acutely activated by seizures in order to compensate for the excess of endogenous adenosine. Furthermore, the upregulation of [3H]NBI uptake sites as revealed by the "in vitro" quantitative autoradiography seems to be organized in selective brain areas related to seizure propagation.

Prevalence and sensitivity to antibiotics of Enterobacteriaceae isolated from urinary cultures in some microbiology laboratories of a city in west Greece

The prevalence of Enterobacteriaceae from midstream urine samples from patients with community acquired urinary tract infections (UTI) of a town in SW Greece during one year period and their susceptibility to antibiotics were studied. The most frequently recovered pathogens were E. coli (77%), Proteus mirabilis (10%), Klebsiella spp (8.7%), Enterobacter spp (2.5%) and Citrobacter freundii (1.8%). E. coli were found more resistant to carbenicillin, the combination of amoxicillin/clavulanic acid and cotrimoxazole. Half of the strains were found resistant to more than one antibiotics. All strains were found sensitive to aminoglucosides, 2nd generation cephalosporines (except cefoxitin), 3rd generation cephalosporines, aztreonam and imipeneme. According to our results a statistically significant increase of the resistance to antibiotics at individuals over 45 years of age was noticed. The positivity of the samples was not correlated to prior antibiotic consumption and to the occupation of the participants or their residence.

Upregulation of A1 adenosine receptors in human temporal lobe epilepsy: a quantitative autoradiographic study

A significant increase of A1 adenosine receptor binding (48% increase of mean) was detected in human neocortex obtained from patients suffering from temporal lobe epilepsy as compared to control neocortex from non-epileptic patients. Such increase was equally distributed in the six cortical layers and reached similar levels in each of the five specimens tested independently of age, sex and pharmacological treatment of the patient. Since adenosine exerts a depressant effect on neocortical neurons in slices obtained from epileptic patients, this upregulation of A1 receptor binding may constitute a protective mechanism against subsequent seizures, which is exerted by elevating the depressant response of the brain to endogenous adenosine.

Effect of pentylentetrazol-induced seizures on A1 adenosine receptor regional density in the mouse brain: a quantitative autoradiographic study

Adenosine has been shown to be a major regulator of neuronal activity in convulsive disorders, exerting its anticonvulsant effect through central A1 adenosine receptors. The aim of the present study was to investigate the effect of generalized tonic-clonic seizures induced by pentylentetrazol on regional changes in A1 adenosine receptor density and distribution in the mouse brain by in vitro quantitative autoradiography. As radioligand the specific agonist of A1 receptors [3H]cyclohexyladenosine was used. After two consecutive (once daily) pentylentetrazol-induced convulsions a widespread upregulation of A1 receptor density was detected with a marked enhancement in structures that mediate seizure activity like hippocampus, mamillary bodies, septum, substantia nigra, thalamic nuclei and cerebral cortices. On the contrary, in basal ganglia a significant downregulation of A1 receptors was observed. These results indicate that: (i) the observed increases or decreases in A1 receptor density are organized in selective anatomical structures related to seizure development rather than uniform in the brain; and (ii) since the upregulation of A1 receptors is sufficient to enhance the physiological depressive response of adenosine, the overall evoked increases seen here may lead to a stronger inhibitory tone and accordingly to a more efficient anticonvulsant effect of endogenous adenosine.

Reduction of A1 adenosine receptors in cortex, hippocampus and cerebellum in ageing mouse brain

Age related changes in A1 adenosine receptor binding were investigated in mouse brain using the selective agonist, [3H]-cyclohexyladenosine ([3H]CHA). In the cortex, hippocampus and cerebellum of aged mice (28 months old), a significant decrease of about 44%, 50% and 12%, respectively, in [3H]CHA binding compared to young animals (3 months old) was observed. According to the Scatchard analysis of the binding data in the cortex, this decrease was due to a receptor density reduction and not to a Kd change. Since the weight and protein content of each tissue tested did not differ significantly between the old and the young animals, our findings may be partly explained by specific reductions of A1 receptors rather than a general cell degeneration in old age.

Changes in seizure latency correlate with alterations in A1 adenosine receptor binding during daily repeated pentylentetrazol-induced convulsions in different mouse brain areas

The seizure latency changed during daily pentylentetrazol (PTZ) induced convulsions showing an increase between days 2 and 4, a rapid decrease between days 5 and 10 and a slight increase again between days 11 and 14. At the respective timepoints, [3H]CHA binding, in cortex and cerebellum of PTZ treated animals followed exactly the same pattern, suggesting that the alterations in A1 receptors in these areas may partly determine the PTZ seizure latency curve. On the contrary, the changes of [3H]CHA binding in hippocampus (sustained increase) and striatum (sustained decrease) didn't follow the latency curve pattern. These results suggest that changes in A1 receptor density in specific brain areas may be involved in the modulation of seizure susceptibility.

Alterations of A1 adenosine receptors in different mouse brain areas after pentylentetrazol-induced seizures, but not in the epileptic mutant mouse 'tottering'

Single and repeated Pentylentetrazol (PTZ)-induced convulsions are associated with significant changes of A1 adenosine receptors (detected using the radioligand [3H]cyclohexyladenosine, [3H]CHA) in 4 different brain areas of the mouse, namely cortex, hippocampus, cerebellum and striatum. In hippocampus and cerebellum, a rapid increase in [3H]CHA binding, by 26% and 30% respectively, was observed 1 h after a single PTZ convulsion. In striatum, on the contrary, a significant decrease by 30% in [3H]CHA binding was seen, whereas in cortex no significant change could be detected. After daily repeated PTZ convulsions, a significant increase of A1 receptors by 26% appeared also in cortex, while the changes of A1 receptors observed in the other brain areas after a single PTZ convulsion were maintained in almost the same range. All the alterations observed were due to changes of the total number of A1 receptors (Bmax) without changes in receptor affinity (Kd). A significant increase in the latency of PTZ seizure (time between the PTZ-injection and the beginning of the seizure) was also observed after repeated PTZ-induced convulsions at the time when the changes in A1 adenosine receptors were noted. Considered together, these results provide further evidence for an A1 receptor-mediated modulation of seizure susceptibility and indicate that specific brain areas may play different roles in this modulation. The binding of [3H]CHA to membranes from different cortical and subcortical areas of the epileptic mutant mouse 'tottering' was not different from that in control animals.