Serological studies on an outbreak of smallpox in the State of Bahia - Brazil in 1969

Four weeks after Containment Vaccination undertaken against the largest outbreak of smallpox occured in Brazil in 1969, that of the municipality of Utinga, Bahia, 99 samples of serum were collected from the local population. These samples were classified in four groups: a) - Individuals with a history of variola prior to the beginning of present outbreak in town (15 sera); "Previous smallpox group"; b) - Individuals with primary vaccination, with no record variola, at the time of containment measures (15 sera). "Primary vaccinated group"; c) - Individuals with no previous record of variola revaccinated with "take" at the time of containment (15 sera0, "Revaccinated group"; d) - Individuals who contracted variola in present outbreak (54 sera) these were subdivided in four sub-groups, according to dates on which cases ocurred, "Variola in outbreak group". Serological study of samples was done by tests of hemagglutination inhibition, neutralization, and complement fixation. It was observed that HI titers were significantly lower in cases of previous smallpox than in other groups. Although they were slightly higher on revaccinated individuals than on primary vaccinated group and than in the group of variola in outbreak, this difference was not significant. Those same antibodies were present in all cases of variola in outbreak, and it was found that titers decreased in direct proportion to time elapsed from occurrence of cases. Neutralizing antibodies proved to be significantly higher on the revaccinated group than on variola in outbreak group, and higher on these than on primary vaccinated and on the previous smallpox groups. In cases from the variola in outbreak it was verified that neutralizing antibodies remained stable, although with great variation in titers. Tests of complement fixation could not be undertaken on all samples, because many of them proved to have anticomplementarity. However, it was found that complement fixing antibodies diminished rapidly, becoming negative for earlier infections. Finally, the authors suggest that there would be some evidence that HI titers are lower in variola minor under Brazilian conditions than in variola major.

Minimal invasive surgery for coronoid fracture: technical note.

Operative treatment of coronoid fracture often requires a large dissection of soft tissue, resulting in elbow stiffness and functional limitation. The authors present a minimal invasive, safe technique, useful in the case of isolated coronoid fracture associated with elbow dislocation. This technique does not require soft tissue dissection and allows an early unlimited resumption of sports activities.

A class of stochastic games with infinitely many interacting agents related to Glauber dynamics on random graphs

We introduce and study a class of infinite-horizon nonzero-sum non-cooperative stochastic games with infinitely many interacting agents using ideas of statistical mechanics. First we show, in the general case of asymmetric interactions, the existence of a strategy that allows any player to eliminate losses after a finite random time. In the special case of symmetric interactions, we also prove that, as time goes to infinity, the game converges to a Nash equilibrium. Moreover, assuming that all agents adopt the same strategy, using arguments related to those leading to perfect simulation algorithms, spatial mixing and ergodicity are proved. In turn, ergodicity allows us to prove “fixation”, i.e. that players will adopt a constant strategy after a finite time. The resulting dynamics is related to zerotemperature Glauber dynamics on random graphs of possibly infinite volume.

Evolutionary switch and genetic convergence on rbcL following the evolution of C4 photosynthesis.

Rubisco is responsible for the fixation of CO2 into organic compounds through photosynthesis and thus has a great agronomic importance. It is well established that this enzyme suffers from a slow catalysis, and its low specificity results into photorespiration, which is considered as an energy waste for the plant. However, natural variations exist, and some Rubisco lineages, such as in C4 plants, exhibit higher catalytic efficiencies coupled to lower specificities. These C4 kinetics could have evolved as an adaptation to the higher CO2 concentration present in C4 photosynthetic cells. In this study, using phylogenetic analyses on a large data set of C3 and C4 monocots, we showed that the rbcL gene, which encodes the large subunit of Rubisco, evolved under positive selection in independent C4 lineages. This confirms that selective pressures on Rubisco have been switched in C4 plants by the high CO2 environment prevailing in their photosynthetic cells. Eight rbcL codons evolving under positive selection in C4 clades were involved in parallel changes among the 23 independent monocot C4 lineages included in this study. These amino acids are potentially responsible for the C4 kinetics, and their identification opens new roads for human-directed Rubisco engineering. The introgression of C4-like high-efficiency Rubisco would strongly enhance C3 crop yields in the future CO2-enriched atmosphere.

Population dynamics of aquatic snails in Pampulha reservoir

An attempt was made to determine more accurately the density of molluskan populations in the Pampulha reservoir, using the quadrate method, intending to detect the fluctuation of the populations density, the habitat conditions and the possible competitive interactions among Biomphalaria tenagophila, Melanoides tuberculata, Pomacea haustrum and Biomphalaria glabrata, through the analysis of populational parameters. Among the most significative facts observed in the reservoir it has to be mentioned: the almost disappearance of B. glabrata; the invasion, colonization, fixation and fast growing of M. tuberculata population until reaching about 11,000 individuals/[square metre]; the density fluctuations of B. tenagophila, P. haustrum and M. tuberculata alives and deads; differences on the habitat preference of these three molluskan species at the edge (at the limit earth-water, at 0.70m and 1.40m from the shore line); monthly mortality rates and reproduction seasons of the species.

International Society of Urological Pathology (ISUP) Consensus Conference on Handling and Staging of Radical Prostatectomy Specimens. Working group 1: specimen handling.

The 2009 International Society of Urological Pathology Consensus Conference in Boston made recommendations regarding the standardization of pathology reporting of radical prostatectomy specimens. Issues relating to the handling and processing of radical prostatectomy specimens were coordinated by working group 1. Most uropathologists followed similar procedures for fixation of radical prostatectomy specimens, with 51% of respondents transporting tissue in formalin. There was also consensus that the prostate weight without the seminal vesicles should be recorded. There was consensus that the surface of the prostate should be painted. It was agreed that both the prostate apex and base should be examined by the cone method with sagittal sectioning of the tissue sample. There was consensus that the gland should be fully fixed before sectioning. Both partial and complete embedding of prostates was considered to be acceptable as long as the method of partial embedding is stated. No consensus was determined regarding the necessity of weighing and measuring the length of the seminal vesicles, the preparation of whole mounts rather than standardized blocks and the methodology for sampling of fresh tissue for research purposes, and it was agreed that these should be left to the discretion of the working pathologist.

Risk factors for Trypanosoma cruzi infection among blood donors in Central Brazil

Characteristics and possible risk factors associated with Trypanosoma cruzi infection among blood donors were assessed within a routine screening programme in blood banks in an endemic area of Chagas disease. 6,172 voluntary blood donors were interviewed and tested for anti-T. cruzi antibodies by Haemagglutination and Complement Fixation tests in six blood banks in Goiânia-Central Brazil from October 1988 to April 1989. An overall prevalence of 2.3% for T. cruzi infection was obtained, being 3.3% for first-time blood donors, and 1.9% for regular ones (p < 0.01). Considering this seropositivity among regular blood donors, selection of candidates relying only on the history of previous donation was found to be inadequate. The risk of infection increased inversely with the degrees of education and monthly income. There was a 9.2 risk of infection (95% CI 3.8-22.6) for those who had lived more than 21 years in an endemic area compared to subjects who had never lived in rural settings, after multivariate analysis. These informations may help to review the criteria of selection of donors in order to improve quality of blood products in endemic areas.

Détectabilité extra-fovéale sur des images anatomiques

Contexte¦- Les métastases hépatiques hypovasculaires sont parfois difficile à détecter car très polymorphiques et fréquemment irrégulières. Leurs contrastes sur CT scan hépatique sont souvent faibles.¦- Lors d'un diagnostic, le radiologue ne fixe pas sa vision fovéale sur chaque pixel de l'image. Les expériences de psychophysique avec eye-tracker montrent en effet que le radiologue se concentre sur quelques points spécifiques de l'image appelés fixations. Dans ce travail, nous nous intéresserons aux capacités de détection de l'oeil lorsque l'observateur effectue une saccade entre deux points de fixation. Plus particulièrement, nous nous intéresserons à caractériser les capacités de l'oeil à détecter les signaux se trouvant en dehors de sa vision fovéale, dans ce qu'on appelle, la vision périphérique.¦Objectifs¦- Caractériser l'effet de l'excentricité de la vision sur la détectabilité des contrastes dans le cas de métastases hépatiques hypovasculaires.¦- Récolter des données expérimentales en vue de créer un modèle mathématique qui permettra, à terme, de qualifier le système d'imagerie.¦- → objectifs du TM en soit :¦o prendre en main l'eyetracker¦o traduire une problématique médicale en une expérience scientifique reproductible, quantifiable et qualifiable.¦Méthode¦Nous effectuons une expérience 2AFC (2 Alternative Forced-Choice experiment) afin d'estimer la détectabilité du signal. Pour cela, nous forcerons l'observateur à maintenir son point de fixation à un endroit défini et vérifié par l'eye-tracker. La position del'excentricité du signal tumoral généré sur une coupe de CT hépatique sera le paramètre varié. L'observateur se verra présenté tour à tour deux coupes de CT hépatique, l'une comportant le signal tumoral standardisé et l'autre ne comportant pas le signal. L'observateur devra déterminer quelle image contient la pathologie avec la plus grande probabilité.¦- Cette expérience est un modèle simplifié de la réalité. En effet, le radiologue ne fixe pas un seul point lors de sa recherche mais effectue un "scanpath". Une seconde expérience, dite en free search sera effectuée dans la mesure du temps à disposition. Lors de cette expérience, le signal standardisé sera connu de l'observateur et il n'y aura plus de point de fixation forcée. L'eyetracker suivra le scanpath effectué par l'oeil de l'observateur lors de la recherche du signal sur une coupe de CT scan hépatique. L'intérêt de cette expérience réside dans l'observation de la corrélation entre les saccades et la découverte du signal. Elle permet aussi de vérifier les résultats obtenus lors de la première expérience.¦Résultats escomptés¦- Exp1 : Quantifier l'importance de l'excentricité en radiologie et aider à améliorer la performance de recherche.¦- Exp 2 : tester la validité des résultats obtenus par la première expérience.¦Plus value escomptée¦- Récolte de données pour créer un modèle mathématique capable de déterminer la qualité de l'image radiologique.¦- Possibilité d'extension à la recherche dans les trois dimensions du CT scan hépatique.

Standardization of serological tests for detecting anti-Trypanosoma cruzi antibodies in dogs

This paper reports on the standardization of four serological reactions currently used in human serodiagnosis for the detection of anti-Trypanosoma cruzi antibodies in naturally and experimentally infected dogs. Indirect immunofluorescence test (IFAT) and hemagglutination test (IHAT) were standardized, and complement fixation test (CFT) and direct agglutination test (DAT) were used for diagnostic confirmation. Four hundred and eighty one mongrel dogs that were studied by xenodiagnosis were used: (1) parasitemic dogs of two localities of endemic area (EA) of Santiago del Estero province in Argentina (n = 134); (2) non-parasitemic dogs of the same area (n = 285); (3) dogs experimentally infected with T. cruzi in the patent period (n = 6); (4) non-infected dogs (n = 56) which were born in the city of Buenos Aires (BA), one non-EA for Chagas' disease. For IFAT, parasitemic dogs EA showed 95% of reactive sera. Non parasitemic dogs EA showed 77% of non reactive sera. None sera from BA were reactive for dilutions higher than four. For IHAT, 84% of sera of parasitemic dogs EA showed serological reactivity and among non parasitemic dogs BA, 61% were non reactive, while the remainder showed at most titres of 1/16. The cut-off titres for IFAT and IHAT were 1/16 and 1/32 respectively, and for CFT and DAT 1/1 and 1/128 respectively. Sensitivity for IFAT, IHAT, CF and DAT were 95%, 84%, 97% and 95% respectively.

Pseudarthroses aseptiques des os longs [Pseudarthrosis of the long bones].

5 to 10% of all fractures present with a delayed union, whereas 1 to 5% progress to a nonunion, which can be defined as a fracture older than 6 months and lacks any potential to heal without any further intervention. Different fracture and patient related risk factors exist, and the management of a nonunion needs a thorough clinical, radiological and biological workup to classify them in one of the two main categories, the viable nonunions that need essentially more stability, usually by a more rigid fixation, and the non-viable nonunions that need essentially a biological stimulation by decortication and bone grafting. This treatment still remains the first choice with bony healing obtained in 85 to 95% of cases, but it also comes along with certain risks, and some valuable alternatives exist if chosen on the basis of rigid criteria.

Alteration of brain glycogen turnover in the conscious rat after 5h of prolonged wakefulness.

Although glycogen (Glyc) is the main carbohydrate storage component, the role of Glyc in the brain during prolonged wakefulness is not clear. The aim of this study was to determine brain Glyc concentration ([]) and turnover time (tau) in euglycemic conscious and undisturbed rats, compared to rats maintained awake for 5h. To measure the metabolism of [1-(13)C]-labeled Glc into Glyc, 23 rats received a [1-(13)C]-labeled Glc solution as drink (10% weight per volume in tap water) ad libitum as their sole source of exogenous carbon for a "labeling period" of either 5h (n=13), 24h (n=5) or 48 h (n=5). Six of the rats labeled for 5h were continuously maintained awake by acoustic, tactile and olfactory stimuli during the labeling period, which resulted in slightly elevated corticosterone levels. Brain [Glyc] measured biochemically after focused microwave fixation in the rats maintained awake (3.9+/-0.2 micromol/g, n=6) was not significantly different from that of the control group (4.0+/-0.1 micromol/g, n=7; t-test, P>0.5). To account for potential variations in plasma Glc isotopic enrichment (IE), Glyc IE was normalized by N-acetyl-aspartate (NAA) IE. A simple mathematical model was developed to derive brain Glyc turnover time as 5.3h with a fit error of 3.2h and NAA turnover time as 15.6h with a fit error of 6.5h, in the control rats. A faster tau(Glyc) (2.9h with a fit error of 1.2h) was estimated in the rats maintained awake for 5h. In conclusion, 5h of prolonged wakefulness mainly activates glycogen metabolism, but has minimal effect on brain [Glyc].

GABA receptor subunits in human auditory cortex in normal and stroke cases.

GABA receptors are ubiquitous in the cerebral cortex and play a major role in shaping responses of cortical neurons. GABAA and GABAB receptor subunit expression was visualized by immunohistochemistry in human auditory areas from both hemispheres in 9 normal subjects (aged 43-85 years; time between death and fixation 6-24 hours) and in 4 stroke patients (aged 59-87 years; time between death and fixation 7-24 hours) and analyzed qualitatively for GABAA and semiquantitatively for GABAB receptor subunits. In normal brains, the primary auditory area (TC) and the surrounding areas TB and TA displayed distinct GABAA receptor subunit labeling with differences among cortical layers and areas. In postacute and chronic stroke we found a layer-selective downregulation of the alpha-2 subunit in the anatomically intact cerebral cortex of the intact and of the lesioned hemisphere, whereas the alpha-1, alpha-3 and beta-2/3 subunits maintained normal levels of expression. The GABAB receptors had a distinct laminar pattern in auditory areas and minor differences among areas. Unlike in other pathologies, there is no modulation of the GABAB receptor expression in subacute or chronic stroke.

Mitotic figure counts are significantly overestimated in resection specimens of invasive breast carcinomas.

Several authors have demonstrated an increased number of mitotic figures in breast cancer resection specimen when compared with biopsy material. This has been ascribed to a sampling artifact where biopsies are (i) either too small to allow formal mitotic figure counting or (ii) not necessarily taken form the proliferating tumor periphery. Herein, we propose a different explanation for this phenomenon. Biopsy and resection material of 52 invasive ductal carcinomas was studied. We counted mitotic figures in 10 representative high power fields and quantified MIB-1 immunohistochemistry by visual estimation, counting and image analysis. We found that mitotic figures were elevated by more than three-fold on average in resection specimen over biopsy material from the same tumors (20±6 vs 6±2 mitoses per 10 high power fields, P=0.008), and that this resulted in a relative diminution of post-metaphase figures (anaphase/telophase), which made up 7% of all mitotic figures in biopsies but only 3% in resection specimen (P<0.005). At the same time, the percentages of MIB-1 immunostained tumor cells among total tumor cells were comparable in biopsy and resection material, irrespective of the mode of MIB-1 quantification. Finally, we found no association between the size of the biopsy material and the relative increase of mitotic figures in resection specimen. We propose that the increase in mitotic figures in resection specimen and the significant shift towards metaphase figures is not due to a sampling artifact, but reflects ongoing cell cycle activity in the resected tumor tissue due to fixation delay. The dwindling energy supply will eventually arrest tumor cells in metaphase, where they are readily identified by the diagnostic pathologist. Taken together, we suggest that the rapidly fixed biopsy material better represents true tumor biology and should be privileged as predictive marker of putative response to cytotoxic chemotherapy.

Production of an affinity-purified antibody against an aldehyde-treated neurofilament protein for use in immunocytochemistry.

Fixation enhances cellular morphology and reduces loss of molecules during tissue processing. Antibodies against fixation-resistant epitopes are very useful, because they allow an immunocytochemical detection in tissue of better preserved morphology. However, fixatives can alter antigenicity and adversely affect the result of immunohistochemical procedures. To address this problem, this study examined the feasibility of generating antibodies to a paraformaldehyde-fixed antigen for use in immunohistochemical procedures. The large subunit of neurofilament proteins was selected for this study. Crude neurofilament proteins were isolated and separated by SDS-polyacrylamide gel electrophoresis. The large subunit of neurofilaments (NF-H) was electroeluted from the electrophoresis gel and exposed to paraformaldehyde, and used for immunization of a rabbit. The rabbit antiserum was affinity purified on CNBr-sepharose immobilized neurofilament proteins. On Western blots, the antibody reacted with the NF-H protein in a phosphorylation-dependent manner. In aldehyde-fixed cerebellum, the antibody strongly stained axons. In contrast, in alcohol-fixed cryostat sections the immunocytochemical detection was substantially reduced. The procedure presented in this study, involving a simple pretreatment of the immunogen, allows for the generation of an antibody that may be used in immunohistochemical studies where localization of the immunogen may be reduced or even lost by aldehyde fixation.