Metal loads and biomarker suite responses in a tropical carnivorous fish indicative of anthropogenic impacts in a Southeastern Brazilian lagoon.

Tropical coastal lagoons are highly productive environments exhibiting high biodiversity. However, the use of these ecosystems by local communities is of concern, since this generally leads to environmental degradation. The Imboassica coastal lagoon, located in Macaé city, in Northern Rio de Janeiro, is an important ecosystem in the state, however, already displaying signs of anthropogenic impacts. Carnivorous fish Hoplias malabaricus specimens were sampled from this impacted site, as well as from a reference area. Fish from Imboassica Lagoon presented lower condition factor, lower cholinesterase activity, and higher percentage of erythrocyte micronuclei when compared to fish from the reference site. Metals in fish from Imboassica Lagoon were always higher than Encantada Lagoon, with some seasonal differences, where some metals were higher in the rainy season compared to the dry season in muscle tissue, with the exception of Cu, Fe, Sr, and Zn; and in the liver, except for Ba, Cd, Cr, Ni, and Sr. Cr and Mn in the edible muscle portion of the fish were higher than the limits established by Brazilian and International legislations as permissible for human consumption, thus leading to concerns regarding public health risks for the local population that use fish as their main protein source.

Computer identification of Shigella species by rRNA gene restriction patterns.

We describe a MluI ribotyping scheme for Shigella which approaches correlation with serotyping. One hundred and seventeen reference strains and previously serotyped clinical isolates representing the 57 Shigella serotypes and biotypes were included in this study. A total of 51 distinct ribotypes were obtained and a database was built with them. The number of bands composing each ribotype varied from 9 to 15. The fragments ranged in size from 1.6 to 18.8 kbp. One hundred and eleven clinical isolates were successfully identified in a double blind study with standard biochemical/serologic methods, by automatic comparison of their ribotypes with our database using the software Taxotron.

Molecular and phenotypic characterization of potentially new Shigella dysenteriae serotype.

From September 1997 to November 1998, the French National Center for Salmonella and Shigella received 22 Shigella isolates recovered from 22 different patients suffering from dysentery. None of these isolates reacted with any of the antisera used to identify established Shigella serotypes, but all of them agglutinated in the presence of antisera to a previously described potentially new Shigella dysenteriae serotype (represented by strain 96-204) primarily isolated from stool cultures of imported diarrheal cases in Japan. All French isolates, as well as strain 96-204, showed biochemical reactions typical of S. dysenteriae and gave positive results in a PCR assay for detection of the plasmid ipaH gene coding for invasiveness. No Shiga toxin gene was detected by PCR. These isolates were indistinguishable by molecular analysis of ribosomal DNA (ribotyping) and seemed to be related to S. dysenteriae serotypes 3 and 12. However, further characterization by restriction of the amplified O-antigen gene cluster clearly distinguished this new serotype from all other Shigella or Escherichia coli serotypes.

Clonal relationships among Shigella serotypes suggested by cryptic flagellin gene polymorphism.

The presence of cryptic fliC alleles in the genomes of 120 strains representative of the four Shigella species was investigated. One fragment was obtained by PCR amplification of fliC, with a size varying from 1.2 to 3.2 kbp, depending on the species or serotype. After digestion with endonuclease HhaI, the number of fragments in patterns varied from three to nine, with sizes of between 115 and 1,020 bp. Patterns sharing most of their bands were grouped to constitute an F type. A total of 17 different F types were obtained from all strains included in this study. A unique pattern was observed for each the following serotypes: Shigella dysenteriae 1, 2, 8, and 10 and S. boydii 7, 13, 15, 16, and 17. On the contrary, S. dysenteriae serotype 13 and S. sonnei biotype e were each subdivided into two different F types. S. flexneri serotypes 3a and X could be distinguished from the cluster containing S. flexneri serotypes 1 to 5 and Y. S. flexneri serotype 6 clustered with S. boydii serotypes 1, 2, 3, 4, 6, 8, 10, 11, 14, and 18 and S. dysenteriae serotypes 4, 5, 6, 7, 9, 11, and 12. Two other clusters were outlined: one comprising S. dysenteriae serotypes 3, 12, 13 (strain CDC598-77), 14, and 15 and the other one joining S. boydii serotypes 5 and 9. None of the 17 fliC patterns was found in the fliC HhaI pattern database previously described for Escherichia coli. Overall, this work supports the hypothesis that Shigella evolved from different ancestral strains of E. coli. Moreover, the method outlined here is a promising tool for the identification of some clinically important Shigella strains as well as for confirmation of atypical isolates as Shigella spp.

Identification of Escherichia coli O-serogroups by restriction of the amplified O-antigen gene cluster (rfb-RFLP).

The precise serotyping of clinical Escherichia coli isolates is a crucial step for diagnostic and epidemiological purposes. Epidemiological knowledge associated with serotyping is so important that no alternative method may be considered if it does not correlate with serotyping. Unfortunately, E. coli are difficult to serotype. Genes specifically involved in O-antigen synthesis are clustered in E. coli, Shigella and Salmonella. Published oligonucleotide sequences complementary to JUMPstart and the gnd gene (the conserved flanking sequences upstream and downstream of O-antigen gene clusters, respectively) were used to amplify the O-antigen gene cluster of representative strains of 148 E. coli O-serogroups. A unique amplified fragment was observed for each serogroup (size ranging from 1.7 to 20 kbp). Clearly identifiable and reproducible O-patterns were obtained for the great majority of O-serogroups after MboII digestion of amplified products. The number of bands composing each pattern varied from five to 25. A database was built with the patterns obtained. A total of 147 O-patterns were obtained. Thirteen O-serogroups were subdivided into different O-patterns. However, each of 13 other O-patterns was shared by two or more O-serogroups. 0-serogroups of clinical isolates were deduced accurately from O-patterns in all cases, even for some rough or nonagglutinating isolates. The restriction method (rfb-RFLP) may prove to be better than serotyping since 100% of strains are typable, which is not the case with serotyping.

Identification of Shigella serotypes by restriction of amplified O-antigen gene cluster.

Due to the scarcity of distinctive biochemical reactions for differentiation of Shigella-Escherichia coli, antigenic analysis has long been used for identification and typing of Shigella isolates. Nevertheless, several intra- and interspecific cross-reactions have been reported to disturb serotyping assays. Shigella serotyping is also occasionally affected by the transition from the smooth (S) form to the rough (R) form. Thus, there is a need for the development of novel robust and discriminating methods for Shigella identification and typing. Characteristically, all genes specifically involved in O-antigen synthesis are clustered in E. coli, Shigella, and Salmonella. Published oligonucleotide sequences complementary to JUMPstart and gene gnd, the conserved flanking sequences upstream and downstream of O-antigen gene clusters, were used to amplify the O-antigen gene cluster of representative strains of each Shigella serotype. A unique, amplified fragment was generally observed for each serotype (size ranging from 6 kbp to 17 kbp). Clearly identifiable and reproducible patterns were obtained for each serotype after MboII digestion of the products, except for S. boydii 12 which showed two distinct patterns, and S. flexneri serotypes 1 to 5 and X and Y which showed a single pattern. A database was built with the Taxotron package allowing automated identification of clinical Shigella isolates to all known serotypes.

Embolia arterial de membros inferiores: estudo dos fatores relacionados à morbidade e à mortalidade operatórias / Arterial embolism of the lower limbs: a study of factors related to operative morbidity and mortality

A embolia arterial periférica é uma doença frequente entre as urgências vasculares e apresenta índices de morbidade e de mortalidade elevados. Setenta e dois doentes que foram submetidos à embolectomia arterial de membros inferiores são analisados retrospectivamente, com o objetivo de estudar, pela análise multivariada, a influência de diferentes fatores na morbidade e na mortalidade do procedimento operatório. A mortalidade opertória da série foi de 25 'por cento', sendo 44,4 'por cento', de origem cardíaca. A análise estatística foi realizada pela análise multivariada (MULTLR). A rabdomiólise, a exploração da artéria poplítea e a aterosclerose periférica foram os fatores de risco para a amputação. Além da exploração da artéria poplítea e da aterosclerose periférica, a impotência funcional à admissão e a doença pulmonar obstrutiva crônica foram os fatores de risco para complicaçöes sistêmicas. A análise da mortalidade identificou como fatores de risco a complicação pulmonar, a síndrome de revascularização tardia e o infarto do miocárdio.

Experimental infection of Wistar rats with 'Gastrospirillum suis'.

In order to develop a model for the study of gastric spiral bacteria, and based on the observation that Wistar rats do not carry urease-positive spiral bacteria in their gastric mucosa, mucus from a pig naturally colonised by 'Gastrospirillum suis' (an organism with I6S rDNA 99.5% similar to that of 'G. hominis' type 1), was inoculated into 35 Wistar rats (test group). Fourteen rats were given mucus taken from 'G. suis'-negative swine (control group). Five test animals and two controls were killed 1, 2, 4, 8, 12, 26, and 52 weeks after inoculation. 'G. suis' was observed in the antral mucosa of all test rats but not in the gastric mucosa of any control animal. The number of organisms was high from the beginning of the infection and increased over the period of observation. The bacteria were seen deep in the gastric antral glands, especially in the advanced stages of infection. Histological study of two test rats killed 1 week after inoculation and of all rats killed from the second week after infection revealed the presence of a mild inflammatory response characterised by the infiltration of small numbers of mononuclear cells and scarce polymorphonuclear cells in the subglandular region of the antral mucosa. Lymphoid aggregates were observed in the antral mucosa of rats killed from 1 month onwards, and increased in size and number over the period of infection. Control animals did not have any histological changes in the gastric mucosa. The natural transmission of the bacterium from rat to rat was also investigated. Five non-inoculated animals (contact group) and rats of the test group were maintained in the same cage and killed after 12 weeks. Two animals of the contact group showed slight infiltration of mononuclear cells in the antral mucosa, although they were not colonised by 'G. suis', a finding that supports the hypothesis of faecal-oral transmission of gastric Helicobacter spp. This animal model could be used not only to understand different aspects of the relationship between spiral bacteria and the gastric mucosa but also to obtain large numbers of the organism, free from other spiral bacteria to study some of its properties.

Hypertonic volume therapy: feasibility in the prevention and treatment of multiple organ failure and sepsis.

Small-volume resuscitation by means of bolus infusion of hypertonic saline solutions was first applied for the primary treatment of severe hemorrhagic and traumatic shock and promptly restored central hemodynamics and regional organ blood flow. Mechanisms of action are diverse--i. maintenance of high cardiac output (direct myocardial stimulation; increase in intravascular volume); ii. maintenance of peripheral arterial vasodilation (effect of hyperosmolality; plasma volume effect) and iii. reduction of tissue edema (shifting of tissue water along the osmotic gradient). These mechanisms promote the restoration of the severely impaired microcirculation frequently seen also in sepsis. Hypertonic volume therapy has been the object of several experimental studies of acute hyperdynamic endotoxemia, however, a greater number of clinical studies have to be developed for the better understanding of the positive, and perhaps hazardous, effects of small-volume resuscitation in sepsis and multiple organ failure. The aim of this paper is to review the concepts involving such solutions, and their potential use in treatment of profound hypovolemia and microcirculatory deterioration associated with sepsis and endotoxic shock.

Spiral bacterium associated with gastric, ileal and caecal mucosa of mice.

A spiral shaped bacterium was seen in smears and histological sections (stained by carbolfuchsin) of gastric, ileal and caecal mucosa as well as in stool smears from mice. A significant correlation between the presence of the spiral bacterium and the occurrence of gastritis was observed but the ileal and caecal mucosa seemed unaffected. The bacterium was Gram negative and grew on BHM and Skirrow's medium, under microaerophilic conditions, at 37 degrees C. Its major biochemical characteristics included positive catalase and oxidase reactions and a rapidly positive urease test. There were 2 or 3 spiral turns per cell and a tuft of up to 12 sheathed flagella on each pointed end. Entwined, braided periplasmic fibrils covered the surface of the cell. This spiral bacterium seemed to be part of the normal intestinal flora but was associated with gastritis.