Biochemical characteristics and antigenic structures of Chlamydia

New biotechnology in immunology and molecular biology has enabled the identification and definition of the structure of glycolipids and especially membrane proteins of Chlamydia. Chlamydia antigen lipopolysaccharide, major outer membrane protein, protein 74 kDa, eukaryotic cell binding protein and cysteine rich proteins are all carriers of antigenic determinants, genus, species or type specific. They are very usefull for diagnosis of Chlamydial infections and epidemiological studies. These membranous antigens have an important role in the pathogenesis of these bacteries. Finally these studies have contributed to the isolation of a new species: C. pneumoniae (TWAR strains).     

Platelet-rich plasma serotonin levels in tension-type headache and depression

We measured platelet-rich plasma (PRP) serotonin in patients suffering from tension-type headache, before and after treatment with amitriptyline, comparing them with a healthy control group and patients with untreated depression. We evaluated the severity of headache and depression in each group. PRP serotonin levels were higher in patients with headache than in controls and depressed patients. We observed a fall of PRP serotonin in patients with tension-type headache to similar levels after treatment as the depressed group. This fall was correlated with the improvement of headache but not with depression scales. Our data suggest that the rise of platelet serotonin levels in tension-type headache is related to pain and not depression.     

Rapp-Hodgkin Syndrome with Pili Canaliculi

Abstract: A 20-year-old woman and her 12-year-old brother had hypohidrotic ectodermal dysplasia, cleft lip and palate, midfacial hypoplasia with narrow nose from the nasal bridge to the tip, narrow dysplastic nails, and conical teeth and hypodontia, and hypospadias and hypoplastic uvula in the boy. The woman had major underdevelopment of intellectual capacity. The most important hair anomalies in both siblings were sparse eyebrows, pili torti, and pili canaliculi. Some of the pili canaliculi had two canals (pili bicanaliculi), and the cross section for scanning electron microscopy had a quadrangular aspect. This is the seventh family reported with Rapp-Hodgkin ectodermal dysplasia.     

The effect of harmaline on intestinal sodium transport and on sodium-dependentd-glucose transport in brush-border membrane vesicles from rabbit jejunum

Harmaline inhibition of sodium uptake and of sodium-dependentd-glucose transport was investigated using brush-border membrane vesicles from frozen rabbit jejunum. Under sodium-gradient conditions, initiald-glucose uptake (20 s) was inhibited by harmaline at concentrations above 0.5 mM, but at lower harmaline concentrationsd-glucose uptake was stimulated by 10–15%. When a similar potassium gradient was used, harmaline had no effect. At concentrations upt to 2 mM, harmaline did not alter the equilibrium uptake ofd-glucose ord-mannitol. After pre-equlibration with sodium (25 mM),d-glucose uptake was inhibited at harmaline concentrations ranging from 0.1 to 2 mM. Sodium (10 mM) uptake was also inhibited by harmaline. Increasing the sodium concentration reduced the inhibitory effect of harmaline on tracer sodium uptake as well as on sodium-dependentd-glucose uptake. Similar to phlorizin, harmaline (1 mM) was able to prevent glucose-induced sodium influx across the brush-border membrane.Sodium uptake into brush-border membrane vesicles seems to be inhibited at lower harmaline concentrations than sodium-dependentd-glucose uptake. At high (2 mM) inhibitor concentrations, however, sodium-dependent glucose uptake is more strongly inhibited than sodium uptake. These results suggest that harmaline inhibits both sodium and sodium-dependent transport across intestinal brush-border membranes by interacting with specific sodium-binding sites.     

Circulating inflammatory mediators during start of fever in differential diagnosis of gram-negative and gram-positive infections in leukopenic rats

Gram-negative and gram-positive infections have been considered the most important causes of morbidity and mortality in patients with leukopenia following chemotherapy. However, discrimination between bacterial infections and harmless fever episodes is difficult. Because classical inflammatory signs of infection are often absent and fever is frequently the only sign of infection, the aim of this study was to assess the significance of serum interleukin-6 (IL-6), IL-10, macrophage inflammatory protein-2 (MIP-2), procalcitonin (PCT), and C-reactive protein (CRP) patterns in identifying bacterial infections during start of fever in normal and cyclophosphamide-treated (leukopenic) rats following an injection of lipopolysaccharide (LPS) or muramyl dipeptide (MDP) as a model for gram-negative and gram-positive bacterial infections. We found that, compared to normal rats, immunosuppressed animals exhibited significantly higher fevers and lesser production of all mediators, except IL-6, after toxin challenge. Moreover, compared to rats that received MDP, both groups of animals that received an equivalent dose of LPS showed significantly higher fevers and greater increase in serum cytokine levels. Furthermore, in contrast to those in immunocompetent rats, serum levels of IL-6 and MIP-2 were not significantly changed in leukopenic animals after MDP injection. Other serum markers such as PCT and CRP failed to discriminate between bacterial stimuli in both groups of animals. These results suggest that the use of the analyzed serum markers at an early stage of fever could give useful information for the clinician for excluding gram-negative from gram-positive infections.     

Caspase-dependent and -independent DNA fragmentation in Sertoli and germ cells from men with primary testicular failure: relationship with histological diagnosis

BACKGROUND: Germ cell elimination and sperm DNA fragmentationin men with primary testiculopathies involve apoptosis-relatedprocesses whose mechanisms are poorly understood. This studyexamines the participation of typical (caspase-dependent) andatypical (caspase-independent) pathways in these processes.METHODS: Caspase activity and DNA fragmentation were evaluatedin Sertoli and germ cells from 63 men with non-obstructive azoospermiaand with different histological diagnoses who were undergoingtesticular biopsy for an assisted reproduction attempt. In eightof these men, phosphatidylserine externalization was also examined.RESULTS: The percentage of Sertoli cells showing caspase activityand DNA fragmentation was low and uniform in all diagnoses.In germ cells that remained tightly associated with Sertolicells despite vigorous mechanical treatment, the incidence ofboth caspase activity and DNA fragmentation was high, particularlyin men with maturation arrest. In Sertoli cell-free germ cells,high incidence of DNA fragmentation contrasted with low incidenceof caspase activity and phosphatidylserine externalization.CONCLUSIONS: In men with primary testicular failure, apoptosisof Sertoli cells is insignificant. Some germ cells undergo caspase-dependentapoptosis, show phosphatidylserine externalization and are tightlyassociated with Sertoli cells. Other germ cells show caspase-independentDNA fragmentation, do not externalize phosphatidylserine andlack a tight association with Sertoli cells.     

Lymphoepithelioma-like carcinoma of the bladder: three cases with clinicopathological and p53 protein expression study

Lymphoepithelioma-like carcinoma of the bladder is an uncommon neoplasm, of which 49 cases have been described in the English literature, none of which has been studied for p53 protein expression. We studied three muscle-infiltrating cases of this tumor using immunohistochemical, in situ hybridization and polymerase chain reaction (PCR) methods. The three cases were positive for epithelial markers and negative for lymphoid antigens in the tumoral syncytial areas. The intensive infiltrate of small cells was negative for epithelial and positive for lymphoid markers. This population was mainly made up of cytotoxic T-lymphocytes, positive for TIA-1. p53 protein was intensely positive in more than 90% of the epithelial component nuclei, being negative in the lymphoid cells. PCR study did not show mutations on p53. Both lymphocytes and epithelium were negative for Epstein–Barr virus markers, such as the latent membrane protein and EBER (Epstein–Barr-encoded RNA). The prognosis was very good after radiotherapy and chemotherapy treatment, preserving the bladder despite the muscle infiltration. The presence of an intense cytotoxic T-lymphocyte population may be related to this good prognosis. Both aspects, p53 protein status and T-lymphoid population, had never been studied before in bladder lymphoepithelioma-like carcinoma.     

Evolution of foot-and-mouth disease virus

Foot-and-mouth disease virus evolution is strongly influenced by high mutation rates and a quasispecies dynamics. Mutant swarms are subjected to positive selection, negative selection and random drift of genomes. Adaptation is the result of selective amplification of subpopulations of genomes. The extent of adaptation to a given environment is quantified by a relative fitness value. Fitness values depend on the virus and its physical and biological environment. Generally, infections involving large population passages result in fitness gain and population bottlenecks lead to fitness loss. Very different types of mutations tend to accumulate in the foot-and-mouth disease virus (FMDV) genome depending on the virus population size during replication. Quasispecies dynamics predict higher probability of success of antiviral strategies based on multivalent vaccines and combination therapy, and this has been supported by clinical and veterinary practice. Quasispecies suggest also new antiviral strategies based on virus entry into error catastrophe, and such procedures are under investigation. Studies with FMDV have contributed to the understanding of quasispecies dynamics and some of its biological implications.     

Morphological features in human cortical brain microvessels after head injury: a three-dimensional and immunocytochemical study

We studied the morphology of cortical microvessels in the brains of 10 patients who had died after receiving a traumatic head injury (THI). Scanning electron microscopy (SEM) of vascular corrosion casts, confocal microscopy of histological sections after immunocytochemistry, and detection of apoptosis by terminal dUTP nick end labeling (TUNEL) were used. Microvascular casts showed an angioarchitectonic distribution that was defined as normal according to results obtained in a previous, nontraumatic series of subjects. However, when we compared them with previous works, the cast surface of some of the microvessels showed three types of morphological alterations: longitudinal folds, sunken surfaces with craters, and a significant flattening with reduction of lumen. The vessels that were primarily affected were the arterioles and capillaries of the middle and deep cortical vascular zones. Immunostaining with the monoclonal antibody MAS-336 against endothelial cells also showed the presence of longitudinal folds with a thinning of the vascular lumen, cytoplasmic round bodies, and a thickening of the endothelial cell membrane. The TUNEL technique revealed a positive staining of some endothelial cells. The structural alterations we observed indicate that microvessels undergo endothelial cell damage after THI. We suggest that this kind of lesion and the secondary functional injury to the blood-brain barrier (BBB) could play an important role in the development of the secondary lesions that these patients show in the subacute phase.