Chlamydia trachomatis detection in a population of asymptomatic and symptomatic women: correlation with the presence of serological markers for this infection

A study of 371 women (261 asymptomatic and 110 symptomatic subjects with clinical PID) was performed to detect the presence of Chlamydia trachomatis (C.t.) and to correlate the serological markers against this microrganism, such as antibody to chlamydial hsp60 (Ab-Chsp60) and different levels of IgG, IgM and IgA, with epidemiology, pathology, sexual habits, age, diagnostic methods in the groups of women with and without pelvic inflammatory disease (PID). We found a statistically significant difference between the asymptomatic and symptomatic women regarding the presence of C.t. (3.4% versus 20%; p<0.0001). This presence was affected by the age of women (more in the group < or =25 years old), by having sex with new partners mainly if they did not undergo an antibiotic treatment. The association of antibody Chsp60 with the presence of clinical PID was quite striking. We also found a strict correlation between the detection of Ab-Chsp60 and previous chlamydial infection as well as between Ab-Chsp60 and elevated serum chlamydial IgG or IgA levels. Due to these findings, we can say that the use of serological markers for C.t. in clinical practice may be an important tool for an early screening and diagnosis of women at high risk of chlamydial infection.     

Twenty-first century brain banking: practical prerequisites and lessons from the past: the experience of New York Brain Bank,Taub Institute,Columbia University

Generally accepted methods for processing postmortem brains are lacking, despite the efforts of pioneers in the field, and the growing awareness of the importance of brain banking for investigating the pathogenesis of illnesses unique to humans. Standardizing methods requires compromises, institutional or departmental mindset promoting collaboration, and the willingness to share ideas, information, and samples. A sound balance between competition and institutional interests is needed to best fulfill the tasks entrusted to health care institutions. Thus, a potentially widely accepted protocol design involves tradeoffs. We successfully integrated brain banking within the operation of the department of pathology. We reached a consensus whereby a brain can be utilized for diagnosis, research, and teaching. Thus, routing brains away from residency programs is avoided. The best diagnostic categorization possible is being secured and the yield of samples for research maximized. Thorough technical details pertaining to the actual processing of brains donated for research were recently published. Briefly, one-half of each brain is immersed in formalin for performing the neuropathologic evaluation, which is combined with the teaching task. The contralateral half is extensively dissected at the fresh state to obtain samples ready for immediate disbursement once categorized diagnostically. The samples are tracked electronically, which is crucial. This important tracking system is described separately in this issue. This report focuses on key lessons learned over the past 25 years of brain banking including successful solutions to originally unforeseen problems.     

Oxidation as a crucial reaction for cholesterol to induce tissue degeneration: CD36 overexpression in human promonocytic cells treated with a biologically relevant oxysterol mixture

Oxidative stress, inflammation and altered cholesterol metabolism and levels are among the pathogenetic mechanisms of cognitive impairment that may accompany aging. Within the research area of hypercholesterolemia and age-related disease processes, the molecular mechanisms of cholesterol interaction with the inflammatory cells of the macrophage lineage are yet to be elucidated. We thus investigated the effect of both non-oxidized and oxidized cholesterol on monocytic cell differentiation and foam cell formation, as it occurs within vascular lesions during progression of atherosclerosis. In vitro experiments performed on human U937 promonocytic cells showed that a biologically representative mixture of oxysterols markedly stimulated CD36 expression and synthesis. In contrast, non-oxidized cholesterol did not exert any effect on CD36 mRNA and protein levels. Furthermore, the oxysterol-induced up-regulation of CD36 appeared to be based on the subsequent activation of protein kinase Cdelta (PKCdelta), extracellular signal-regulated kinase 1/2 (ERK1/2) and peroxisome proliferator-activated receptor gamma (PPARgamma). Cells overexpressing CD36 were indeed able to actively take up oxidized low-density lipoproteins, and become foam cells. The essential role of ERK pathway and CD36 receptor in oxysterol-induced foam cell formation was proved by the prevention of the latter event when monocytic cells were incubated in the presence of MEK1/2 selective inhibitor or anti-CD36 specific antibody. These experimental findings point to cholesterol oxidation as an essential reaction for this sterol to exert cellular stress and tissue damage in age-related diseases in which inflammation represents a main driving force.     

Molecular characterization of nitrite reductase gene (aniA) and gene product in Neisseria meningitidis isolates: is aniA essential for meningococcal survival?

The present study evaluates sequence conservation in the gene coding for nitrite reductase (aniA) and AniA expression from a panel of Neisseria meningitidis isolates. Sequence analysis of the coding region in 19 disease-associated and 4 carrier strains notwithstanding a high degree of sequence similarity showed a number of nucleotide changes, some of which possibly resulted in premature translation termination or function loss. In particular, in one disease-associated strain a 9-residues insertion was found to be located close to the type I Cu-site and a catalytic histidine at position 280 was mutated into a leucine. In two strains from carriers, a sequence corresponding to a portion of a transposase gene within the aniA was also found. The AniA protein was always expressed, except for these two carriers strains and for other two strains in which the presence of the premature stop codons was recognized. The biochemical properties of the cloned soluble domain of the enzyme (sAniA) from N. meningitidis reference MC58 strain and from a clinical invasive isolate were studied. In particular, biochemical analysis of sAniA from MC58 demonstrated a clear dependence of its catalytic activity upon acidification, while the clinical isolate-derived sAniA was not functional. Thus, the results obtained suggest that the presence of a conserved and functional aniA gene is not essential for meningococcal survival.     

Stereospecific synthesis and bio-activity of novel beta(3)-adrenoceptor agonists and inverse agonists

Since it is widely distributed into the body, beta(3)-adrenoceptor is becoming an attractive target for the treatment of several pathologies such as obesity, type 2 diabetes, metabolic syndrome, cachexia, overactive bladder, ulcero-inflammatory disorder of the gut, preterm labour, anxiety and depressive disorders, and heart failure. New compounds belonging to the class of arylethanolamines bearing one or two stereogenic centres were prepared in good yields as racemates and optically active forms. They were, then, evaluated for their intrinsic activity towards beta(3)-adrenoceptor and their affinity for beta(1)- and beta(2)-adrenergic receptors. Stereochemical features were found to play a crucial role in determining the behaviour of such compounds. In particular, alpha-racemic, (alphaR)- and (alphaS)-2-{4-[2-(2-hydroxy-2-phenylethylamino)ethyl]phenoxy}-2- methylpropanoic acid, (alpha-rac, beta-rac)-, (alphaR, betaS)- and (alphaR, betaR)- 2-{4-[2-(2-hydroxy-2-phenylethylamino)ethyl]phenoxy}propanoic acid were found to be endowed with beta(3)-adrenoceptor agonistic activity. Whereas, (alphaS, betaS)- and (alphaS, betaR)-2-{4-[2-(2-hydroxy-2-phenylethylamino)ethyl]phenoxy}propanoic acid behaved as beta(3)-adrenoceptor inverse agonists. Such compounds showed no affinity for beta(1)- and beta(2)-adrenergic receptor, respectively. Thus, resulting highly selective beta(3)-adrenoceptor ligands.     

Owls and rabbits: predation against substandard individuals of an easy prey

The interactions among the multiple factors regulating predator-prey relationships make predation a more complex process than previously thought. The degree to which substandard individuals are captured disproportionately seems to be better a function of the difficulty of prey capture than of the hunting techniques (coursing vs. ambushing predators). That is, when the capture and killing of a prey species is easy, substandard individuals will be predated in proportion to their occurrence in the prey population. In the present study, we made use of eagle owls Bubo bubo and their main prey, the rabbit Oryctolagus cuniculus : (a) the brightness of the white tails of rabbits seems to be correlated with the physical condition of individuals, (b) by using the tails of predated rabbits as an index of individual condition, we found that eagle owls seem to prefer substandard individuals (characterized by duller tails), and (c) by using information from continuous radiotracking of 14 individuals, we suggest that the difficulty of rabbit capture could be low. Although the relative benefits of preying on substandard individuals should considerably decrease when a predator is attacking an easy prey, we hypothesise that the eagle owl preference for substandard individuals could be due to the easy detection of poor individuals by a visual cue, the brightness of the rabbit tail. Several elements allow us to believe that this form of visual communication between a prey and one of its main predators could be more widespread than previously thought. In fact: (a) visual signalling plays a relevant role in intraspecific communication in eagle owls and, consequently, visual signals could also play a role in interspecific interactions, and (b) empirical studies showed that signals may inform the predator that it has been perceived, or that the prey is in a sufficiently healthy state to elude the predator.     

Rha1, a new mutant of Arabidopsis disturbed in root slanting,gravitropism and auxin physiology

A new Arabidopsis mutant is characterized (rha1) that shows, in the roots, reduced right-handed slanting, reduced gravitropism and resistance to 2,4-D, TIBA, NPA and ethylene. It also shows reduced length in the shoot and root, reduced number of lateral roots and shorter siliques. The gene was cloned through TAIL-PCR and resulted in a HSF. Because none of the known gravitropic and auxinic mutants result from damage in a HSF, rha1 seems to belong to a new class of this group of mutants. Quantitative PCR analysis showed that the expression of the gene is increased by heat and cold shock, and by presence of 2,4-D in the media. Study of the expression through the GUS reporter gene revealed increased expression in clinostated and gravistimulated plants, but only in adult tissues, and not in the apical meristems of shoots and roots.Key words: auxin, ethylene, slanting, gravitropism, HSFsArabidopsis primary roots, and especially those from some ecotypes (Ws, Landsberg), when grown on an agar dish, tilted on the vertical, show a wavy pattern, and a clear slanting towards a direction that has been considered the right-hand.^1–4 In the case of the mutant rha1, the right-handed slanting is notably reduced, its primary roots growing partly to the right-hand, partly straight down and partly to the left-hand, even though a slight preference for the right-hand is apparent.In addition, its roots show resistance to the inhibitory action of the auxin 2,4-D, ethylene (ACC), and the auxin transport inhibitors TIBA and NPA. These characteristics qualify the mutant as an auxinic one, and therefore a connection between the reduced slanting and the auxinic disturbances could be imagined. It is not known, however, what controls the slanting process itself, even though it appears as the consequence of a chiral circumnutational process. As reported,⁴ it seems the result of a chiral circumnutation with preference for the right-hand, transformed in a lateral slanting movement, because of the impact of the helix with the hard agar surface. This process results in the formation of waves, when the circumnutation helix impactig the agar reverses direction at every half turn, or the formation of large loops and strict loops (coils) when there is no reversion. The latter case seems to be a consequence of the fact that gravity is no longer “felt”. This has been previously noted in some mutants, or sometimes in old roots.rha1 is not the only mutant known to show reduction or increase of slanting, because other mutants were reported by Rutherford and Masson,³ and subsequent publications from the same group. Almost all show an increase of slant, with the exception of rhd3 and its alleles that show a complete suppression of the process.⁵ The mutated gene in rha1 was cloned through TAIL-PCR and shown to be a HSF. No other auxinic mutant, among those for which the gene was cloned, is known to be mutated in a HSF.HSFs, that are characteristically involved in the activation of the HSPs (heat shock proteins), which protect the cells from damage arising from high temperature and other stresses, have been shown to be involved also in different processes.^6,7 Hence, also in the case of rha1, we can well imagine other different functions, beside that of counteracting the heat shock. In particular, since the connection with auxin regulated processes is evident, we can suppose that the action could be on the PP2A phosphatase, as in the case of the rcn1 mutant, or of the human HSF2. The RCN1 protein corresponds to one unit of the PP2A,⁸ and the HSF2⁹ has been shown to substitute itself for the C subunit and alter the function of the phosphatase (Fig. 1). Experiments directed to see if a heat shock can modify the slanting of the roots in the wild-type and rha1, gave negative results, even though these experiments will need to be repeated under more widely ranging conditions. These results seem to indicate that the mechanism which induces asymmetric growth in roots is complex, and it is not controlled by a single gene.Open in a separate windowFigure 1Model proposed for the regulation of the PP2A activity by the RHA1 protein. (modified after Hong and Sarge, 1999).On the other hand, another puzzling characteristic of rha1 is the fact that its roots are resistant only to the auxin 2,4-D, and not to NAA and IAA. Differences in the response of the primary roots to different auxins have already been reported, and it was suggested that the response to NAA should be different, because this substance can penetrate passively the cell membranes.¹⁰ In the case of rha1, however, it seems that IAA can also penetrate the cells passively. This is in line with the chemiosmotic hypothesis,¹¹ but seems in contrast with the previous supposition. The resistance to ethylene, however, could indicate that the reduced inhibitory effect of 2,4-D is a consequence of the ethylene production induced by the synthetic auxin. On the other hand, the resistance to the auxin transport inhibitors TIBA and NPA, cannot be explained so easily. Possibly, in the mutant rha1, there is a reduced level of receptors for the considered substances.Using semiquantitative PCR analysis it was shown that rha1 retains the function of a HSF, the gene being clearly upregulated by heat and cold stress, and also by 2,4-D, but not by rotation on a clinostat or gravistimulation. The upregulation of the expression by 2,4-D was confirmed by a study of GUS expression in a transformed rha1, and with this technique the effects of gravity and simulated microgravity appeared clearly stimulatory too. No GUS expression however was apparent in the shoot and root meristems, and consequently we propose that the gene does not influence the first part of the graviresponse, but possibly the general transport of auxin through the plant.Thus, the mutant seems to be disturbed in root gravitropism, as well as in responses to the auxines and circumnutation. However not in the general circumnutation process, but in its chiral aspect, which is the cause of the slanting to the right-hand. Gravitropism, circumnutation and auxin physiology, thus, seem to be in some way connected in a complex integrated process, that, hopefully, will be gradually revealed in all its different aspects, through the future efforts of plant scientists.     

Preferential locomotion of leukemic cells towards laminin isoforms 8 and 10.

To identify the laminin isoforms of the basement membranes that could be implicated in the extravasation process of neoplastic lymphocytes, a number of purified laminins and one native renal laminin complex were comparatively investigated for their ability to promote migration of neoplastic lymphocytes in vitro. The identity/composition of a human placental laminin complex was asserted by combining immunochemical assays, sequence determination of tryptic peptides, and ultrastructural analysis to be composed predominantly of laminin-10 in which the coiled-coil C-terminal regions and the G globular domain of the alpha5 chain were preserved intact despite the enzymatic treatment used for its isolation. Lymphoma and leukemic cell lines failed to migrate towards laminin-4, -9, -11, moved poorly in response to laminin-1, -2/4, -5 and the renal laminin complex, but markedly locomoted towards the subendothelial laminin-8 and -10. The motility-promoting interaction with these latter laminins was interchangeably mediated by the alpha3beta1 and alpha6beta1 integrins. Lymphocyte locomotion on laminins assayed in the presence of cytokines was either reduced or enhanced suggesting that local cytokine milieu could further influence motility response.