Solubilization and immunological identification of presynaptic alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors in the rat hippocampus

Alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors have been identified mostly as postsynaptic receptors mediating fast glutamatergic synaptic transmission. However, neurochemical studies based on the modulation of neurotransmitter release have suggested the existence of presynaptic AMPA receptors. We have used a recently described technique that allows a high-purity fractionation of the pre- and postsynaptic proteins of synaptic junctions to evaluate the distribution of the different AMPA receptor subunits in rat hippocampal synapses. Surprisingly, we found very high levels of GluR1- and GluR2/3-like immunoreactivity in the presynaptic fraction, but also in the postsynaptic and extrasynaptic fractions. GluR4-like immunoreactivity was much less abundant but was still detected, predominantly in the postsynaptic fraction. This methodology appears to be far more sensitive than the classical immunogold electron microscopy to determine the localization of synaptic receptors.     

Recombinant cysteine proteinase from Leishmania (Leishmania) chagasi implicated in human and dog T-cell responses

High in vitro lymphoproliferative responses were induced in humans and dogs by a recombinant Leishmania (Leishmania) chagasi cysteine proteinase, with secretion of IFN-gamma in asymptomatic subjects or of IFN-gamma, interleukin 4 (IL-4), and IL-10 in oligosymptomatic subjects. In contrast, responses of symptomatic patients and dogs were lower, with production of IL-4 and IL-10.     

Vicker's hardness and Raman spectroscopy evaluation of a dental composite cured by an argon laser and a halogen lamp

We present the results of the Vicker's hardness test and the use of near-infrared Raman spectroscopy (RS) to measure in vitro the degree of conversion (DC) of a bis(phenol)-A-glycidyl-dimethacrylate-based composite resin, photoactivated by both a halogen lamp (power density=478 mW/cm(2); 8-mm diameter spot) and an argon laser (power density=625 mW/cm(2); 7-mm diameter spot). The degree of conversion was estimated by analyzing the relative intensities between the aromatic C=C stretching Raman mode at 1610 cm(-1) and the methacrylate C=C stretching Raman mode (1640 cm(-1)) on top and bottom surfaces. For the hardness evaluation, the samples were embedded in polyester resin and three indentations with a 50-g load for 10 s were made on the top surface. The higher relative DC values achieved by the photoactivation of a composite resin by the argon laser suggest a better biocompatibility in the bottom surface. The correlation test showed that the higher Vicker's hardness number (VHN) values were associated with higher DC values. The derivative analysis showed a greater curing rate from 5 to 20 s of exposure. The comparison of VHN and DC values with both light sources at each curing time showed that a small change in conversion is related to a large change in hardness. Raman spectroscopy is more sensitive to changes in the first stages of curing reaction than later ones, and the Vicker's hardness assay is more sensitive to changes in the last stages.     

Trypanosoma cruzi histone H1 is phosphorylated in a typical cyclin dependent kinase site accordingly to the cell cycle

Histone H1 of most eukaryotes is phosphorylated during the cell cycle progression and seems to play a role in the regulation of chromatin structure, affecting replication and chromosome condensation. In trypanosomatids, histone H1 lacks the globular domain and is shorter when compared with the histone of other eukaryotes. We have previously shown that in Trypanosoma cruzi, the agent of Chagas' disease, histone H1 is phosphorylated and this increases its dissociation from chromatin. Here, we demonstrate using mass spectrometry analysis that T. cruzi histone H1 is only phosphorylated at the serine 12 in the sequence SPKK, a typical cyclin-dependent kinase site. We also found a correlation between the phosphorylation state of histone H1 and the cell cycle. Hydroxyurea and lactacystin, which, respectively, arrest parasites at the G1/S and G2/M stages of the cell cycle, increased the level of histone H1 phosphorylation. Cyclin-dependent kinase-related enzymes TzCRK3, and less intensely the TzCRK1 were able to phosphorylate histone H1 in vitro. Histone H1 dephosphorylation was prevented by treating the parasites with okadaic acid but not with calyculin A. These findings suggest that T. cruzi histone H1 phosphorylation is promoted by cyclin dependent kinases, present during S through G2 phase of the cell cycle, and its dephosphorylation is promoted by specific phosphatases.     

How important is the 'quality' of the cytotoxic T lymphocyte (CTL) response in protection against HIV infection?

Cytotoxic T lymphocyte (CTL) responses have been associated with protection from HIV-1 infection in people with a high degree of exposure to HIV and who show no serological evidence of HIV infection (HEPS, highly exposed persistently seronegative). However, it remains unclear how protective CTL responses could apparently develop in a minority of people, whilst the great majority of HIV-infected people make strong CTL responses yet progress to AIDS and death. In this paper we review the data which supports the hypothesis that the quality of the T-cell response, rather than its magnitude, may be an important factor that merits further investigation.     

Veränderungen von Mäusenieren nach experimenteller Infektion mit Mucambo-Virus

Summary The purpose of this study was to determine whether autoimmune nephritis in rats affects subsequent generations. Moreover, it was planned to study the nature of the changes in the kidneys in subsequent generations of rats. In these experiments eight generations of rats were investigated. The first five generations were immunized with a mixture of -Streptococcus hemolyticus with an emulsion of renal cortical substance; the rats were given from 4 to 8 injections. After the fifth generation the animals were not immunized, but their nephritis was considerably more pronounced than in their parents. In the 6th and 8th generations there was a sharp rise in the number of animals that died, mainly pregnant rats and newborns. In the course of the experiments, the animals were found to have hypertension, elevated blood nitrogen and proteinuria. A morphological investigation of the rats of the 6th, 7th, and 8th generations that were not immunized, but were born of immunized parents, revealed membranous-proliferative glomerulonephritis, which according to its clinical course and morphological data resembled the nephrotic syndrome the mixed type of human glomerulonephritis.

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Zusammenfassung Die Untersuchungen über den Generationswandel der Autoimmunnephritis der Ratte erstreckten sich über 8 Generationen. Bei den ersten 5 Generationen wurde durch eine 4–8malige Injektion einer Mischung aus beta-hämolytischen Streptokokken mit einer Emulsion aus Nierenrindengewebe eine Immunnephritis erzeugt. Die Ratten der 6. bis 8. Generation erhielten keine immunisierenden Injektionen. Trotzdem kam es in der 6. und 8. Generation zu einem akuten Anstieg der Spontantodesrate besonders unter den graviden und neugeborenen Versuchstieren. Klinisch führte die Immun-Nephritis zu einem Blutdruckanstieg, einer Proteinurie und Erhöhung des Harnstoffes. Histologisch entsprachen die Nierenbefunde der 6.–8. Generation einer membranösen proliferativen Glomerulonephritis.

     

Methodology used for "software for automated linkage in Italy" (SALI)

Linkage of epidemiological registries can provide cost-effective information on the associations between different diseases or exposures in the population under study and on completeness of surveillance system databases. We describe the program SALI (software for automated linkage in Italy) aimed at matching individual records from medium-sized registries (in the order of 100,000 records), where the desired outcome is to miss as few links as possible and, because of low link-likelihood (< 1%), a manual revision of matched pairs is feasible. SALI, developed in CA-Clipper language, uses registry files in dBase format. It requires only name, surname, and date of birth as key fields, and it allows for spelling errors in Italian or other Latin languages through a specific algorithm. Furthermore, a double-blind procedure ensures data confidentiality. The main linkage procedure is based on four stages, two automatic ones, and two where the operator can decide through specific windows whether to accept stage-selected matches. SALI takes into account possible errors in key fields thus reducing false negatives. It was used to solve the problem of linkage between AIDS and cancer registries in Italy. It can be used with every IBM-compatible computer system, assuring uniquely high portability.     

Autosomal recessive cleft lip/palate, ectodermal dysplasia, and minor acral anomalies: report of a Brazilian family.

We report on a Brazilian woman, born to consanguineous (first cousin) parents (F = 1/16) and presenting cleft lip/palate, ectodermal dysplasia, interdigital webbing, and other malformations. Parental consanguinity and possible recurrence in sibs suggest autosomal recessive inheritance. The nosologic aspects with the Martinez syndrome and with the Zlotogora-Ogur syndrome are discussed.     

A method for maintaining, in vitro, TV-monitoring and counting ciliary beat frequency of samples from human ciliated respiratory epithelium brushing

"Mucociliary clearance", from a clinical point of view, is one of the most important defense mechanisms of the respiratory mucosa. Clinicians, pneumologists and pharmacologists are greatly interested in methods investigating the cilia, considered the biological engine that continuously moves the physiological and/or pathological bronchial mucous secretions. This paper describes a method for the study of ciliary activity in man. By a simple brushing technique it is possible to obtain samples of ciliated respiratory epithelium, and the ciliary beat can be observed immediately by microscopy (Nomarsky differential interference contrast) in a small thermostatic perfusion chamber. The ciliary image is visualized on a TV monitor by means of a TV camera. Using a new type of digital counter with a phototransistor probe, the beat rate of a single cilium can be measured directly by the monitor screen under physiological or pathological conditions or under drug perfusion.     

Causes of anergy in the surgical patient and its relationship to postoperative sepsis

Between June 1981 and June 1983 the delayed hypersensitivity response (DHR) was studied in 401 patients considered for major surgical procedure: 320 of these patients underwent surgery. The incidence of sepsis and postoperative mortality was higher in anergic and relative anergic patients than in normal responders (p<0.001). To evaluate whether DHR depression in cancer patients was due to the direct effect of cancer or to tumour-linked malnutrition, the 401 patients were divided into 4 groups: 1) 140 malnourished cancer patients, 2) 51 malnourished non-cancer patients, 3) 120 well-nourished cancer patients and 4) 90 well-nourished non-cancer patients. The mean age was not significantly different for the 4 groups. The results showed a relationship between DHR and nutritional status (p<0.001). The tumour-related DHR impairment disappeared when the cancer and non-cancer patient groups were homogeneous with regard to their nutritional status. Therefore, the tumour was able to determine the DHR depression because of the cancer-linked malnutrition. We did not observe any relationship between local extension of the tumour and lymph node involvement and DHR depression. In 90 well-nourished non-cancer patients the relation between DHR and age was investigated. The incidence of anergy and relative anergy was higher in patients over 59 years than in patients under 60 years (p<0.001).