Simple DNA extraction protocol for a 16S rDNA study of bacterial diversity in tropical landfarm soil used for bioremediation of oil waste.

Landfarm soil is used to bioremediate oil wastes from petrochemical industries. We developed a simplified protocol for microbial DNA extraction of tropical landfarm soil using only direct lysis of macerated material. Two samples of tropical landfarm soil from a Brazilian refinery were analyzed by this protocol (one consisted of crude oil-contaminated soil; the other was continuously enriched for nine months with petroleum). The soil samples were lysed by maceration with liquid nitrogen, eliminating the need for detergents, organic solvents and enzymatic cell lysis. Then, the DNA from the lysed soil sample was extracted using phenol-chloroform-isoamyl alcohol or guanidium isothiocyanate, giving high DNA yields (more than 1 micro g DNA/g soil) from both soil types. This protocol compared favorably with an established method of DNA template preparation that included mechanical, chemical and enzymatic treatment for cell lysis. The efficiency of this extraction protocol was confirmed by polymerase chain reaction amplification of the 16S rRNA gene, denaturing gradient gel electrophoresis and cloning assays. Fifty-one different clones were obtained; their sequences were classified into at least seven different phyla of the Eubacteria group (Proteobacteria - alpha, gamma and delta, Chloroflexi, Actinobacteria, Acidobac teria, Planctomycetes, Bacteroidetes, and Firmicutes). Forty percent of the sequences could not be classified into these phyla, demonstrating the genetic diversity of this microbial community. Only eight isolates had sequences similar to known sequences of 16S rRNA of cultivable organisms or of known environmental isolates and therefore could be identified to the genus level. This method of DNA extraction is a useful tool for analysis of the bacteria responsible for petroleum degradation in contaminated environments.

The influence of environmental characteristics on the distribution of ciliates (Protozoa, Ciliophora) in an urban stream of southeast Brazil.

The aim of this research was to study the ciliated protozoa community at three sampling stations that receive different levels of domestic sewage along the São Pedro Stream in the municipality of Juiz de Fora, Minas Gerais, Brazil, in order to determine the influence of organic pollution on this community and to assess the feasibility of using ciliates as water quality indicators. Four physical-chemical parameters of the water samples were evaluated: dissolved oxygen concentration, electrical conductivity, pH and temperature. The sediment was obtained manually, using dredges with capacity of 300 mL, at each collection point. Point 1 was located in a rural region that receives a low sewage load, while Points 2 and 3 were located in populated regions receiving high sewage loads. We found 22 ciliate species, of which 18 are included in the saprobic system and are considered bioindicators. These showed beta-mesosaprobic environments at Point 1 and alfa-mesosaprobic to polisaprobic environments at Points 2 and 3. The low levels of dissolved oxygen and the high electrical conductivity values at Points 2 and 3, together with the strong similarity between the ciliate taxocenoses of these points and the weak similarity between Point 1 and the other two, confirm the high sewage loads received at the latter two points. The combination of the biological indicators and physical-chemical analyses therefore proved itself to be an efficient method of evaluating water quality, and has excellent potential to support decisions on the conservation of headwaters and recuperation of degraded environments in lotic systems.

The influence of environmental characteristics on the distribution of ciliates (Protozoa, Ciliophora) in an urban stream of southeast Brazil / Influência das características ambientais sobre distribuição dos ciliados (Protozoa, Ciliophora) em um córrego urbano no sudeste brasileiro

The aim of this research was to study the ciliated protozoa community at three sampling stations that receive different levels of domestic sewage along the São Pedro Stream in the municipality of Juiz de Fora, Minas Gerais, Brazil, in order to determine the influence of organic pollution on this community and to assess the feasibility of using ciliates as water quality indicators. Four physical-chemical parameters of the water samples were evaluated: dissolved oxygen concentration, electrical conductivity, pH and temperature. The sediment was obtained manually, using dredges with capacity of 300 mL, at each collection point. Point 1 was located in a rural region that receives a low sewage load, while Points 2 and 3 were located in populated regions receiving high sewage loads. We found 22 ciliate species, of which 18 are included in the saprobic system and are considered bioindicators. These showed beta-mesosaprobic environments at Point 1 and alfa-mesosaprobic to polisaprobic environments at Points 2 and 3. The low levels of dissolved oxygen and the high electrical conductivity values at Points 2 and 3, together with the strong similarity between the ciliate taxocenoses of these points and the weak similarity between Point 1 and the other two, confirm the high sewage loads received at the latter two points. The combination of the biological indicators and physical-chemical analyses therefore proved itself to be an efficient method of evaluating water quality, and has excellent potential to support decisions on the conservation of headwaters and recuperation of degraded environments in lotic systems.

O objetivo deste trabalho foi estudar a comunidade de protozoários ciliados em três estações amostrais, que recebem diferentes níveis de lançamento de esgoto doméstico, ao longo do córrego São Pedro, Juiz de Fora, MG, a fim de se determinar a influência da poluição orgânica sobre a composição e distribuição desta comunidade e avaliar a viabilidade da utilização dos ciliados como indicadores da qualidade da água. Foram mensurados quatro parâmetros físico-químicos da água amostrada: teor de oxigênio dissolvido, condutividade elétrica, pH e temperatura. Amostras do sedimento foram obtidas manualmente com o auxílio de dragas, com capacidade de 300 mL, em cada ponto de coleta. O ponto 1, localizado em uma região rural, recebe baixa carga de esgoto, enquanto os pontos 2 e 3, localizados em regiões com ampla ocupação humana, recebem altas cargas de esgoto. Foram registradas 22 espécies de ciliados, sendo que 18 estão incluídas no sistema sapróbio e são consideradas bioindicadoras de ambientes beta-mesossapróbio no ponto 1 e de alfa a polissapróbio nos pontos 2 e 3. Os baixos valores de oxigênio dissolvido e os altos valores de condutividade elétrica registrados nas estações 2 e 3, juntamente com a similaridade entre a taxocenose de ciliados destas estações e a baixa similaridade entre a estação 1 e as demais, confirmaram as altas cargas de esgoto recebidas nestas estações. A união do método biológico com a análise físico-química mostrou-se, portanto, um eficiente método na avaliação da qualidade da água, e apresenta grande potencial de utilização em tomadas de decisões relativas à conservação de nascentes e recuperação de ambientes degradados em sistemas lóticos.

Congenital dacryocystocele with intranasal extension.

PURPOSE: Congenital dacryocystocele is a rare anomaly in the newborn child. The swelling of lachrymal sac is observed by birth and it is associated with obstruction of lachrymal system either above or below lachrymal sac. METHODS: Diagnosis was made by clinical observation. Some ancillary examinations, such as ultrasonography, tomography, and rhinoscopy, were useful. RESULTS: The authors describe the clinical case of a newborn with a unilateral congenital dacryocystocele. This anomaly was successfully treated with probing and marsupialization of the nasal cyst. CONCLUSIONS: Treatment of this congenital anomaly is by light compressive massage, probing with silicone intubation of lachrymal system to assure prolonged permeability of the system, or with marsupialization of the nasal cyst. In some cases with intranasal extension of dacryocystocele, collaboration with an otolaryngologist may be necessary.

Congenital dacryocystocele with intranasal extension.

PURPOSE: Congenital dacryocystocele is a rare anomaly in the newborn child. The swelling of lachrymal sac is observed by birth and it is associated with obstruction of lachrymal system either above or below lachrymal sac. METHODS: Diagnosis was made by clinical observation. Some ancillary examinations, such as ultrasonography, tomography, and rhinoscopy, were useful. RESULTS: The authors describe the clinical case of a newborn with a unilateral congenital dacryocystocele. This anomaly was successfully treated with probing and marsupialization of the nasal cyst. CONCLUSIONS: Treatment of this congenital anomaly is by light compressive massage, probing with silicone intubation of lachrymal system to assure prolonged permeability of the system, or with marsupialization of the nasal cyst. In some cases with intranasal extension of dacryocystocele, collaboration with an otolaryngologist may be necessary. (Eur J Ophthalmol 2004; 15: 126-8).

[Electrophysiological study of the lateral dorsal cutaneous nerve: technical applicability and normal values]. / Estudo eletrofisiológico do nervo cutâneo dorsal lateral: aplicabilidade técnica e valores de referência.

The distal nerve conduction study of the long nerve in the leg is more efficient to work with so that it can establish the early diagnosis of the majority of polyneuropathies. The main purpose of this study is the technical applicability of the orthodromic neural conduction examination of the dorsal cutaneous branch of the sural nerve (lateral dorsal cutaneous nerve) on healthy people, and define the normal values used as references to compare with the proximal segment. Forty five persons mean age 41.56 years old (range 19-75) were examined, and the sensory nerve action potentials were registered from ninety feet. The active recording superficial electrode was placed below and behind the lateral malleolus and the stimulating electrode was placed 10 cm distal to the recording superficial electrode at the dorsal lateral aspect of the feet. The mean value for the lateral dorsal cutaneous nerve conduction velocity was 47.35 +/- 4.8 m/s and for amplitudes 4.19 +/- 1.9 microV. The sensory conduction velocity in the distal segment was 14% lower than the proximal one. The sensory nerve action potential amplitude of the distal segment was 73% lower than the proximal one. The lower normal limit recommended for conduction velocity of this nerve plus correction for skin temperature of 34 degrees C is 38 m/s. Some differences in amplitude and conduction velocity among group ages are to be considered.