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Biomedical subjects

J A Santos

Publications and source records attributed to J A Santos.

At least 19 recordsLinked to original sources

Quantity and quality of oocytes recovered from donor bitches of different ages.

In vitro studies that use isolated oocytes benefit from the ability to harvest oocytes of excellent morphological quality in sufficient numbers to allow the replicability of techniques and experiments. The objective of the present study was to verify the effect of the age of the donor bitch on the quantity and quality of oocytes recovered from isolated ovaries, using the slicing technique. Ten bitches (45 days to 13 years) were ovariohysterectomized, and the ovaries were placed in phosphate buffered saline (PBS), supplemented with bovine fetal serum (5%), and oocyte-cumulus-complexes (OCCs) were obtained by slicing the ovarian tissue. The OCSs were classified morphologically as Degree I (DI, best), Degree II (DII) and degenerated. A total of 427 oocytes were acquired, including 81, 109 and 237 that were graded as DI, DII and degenerated, respectively. Slicing yielded no OCS from animals < 2 months of age. In senile (> 9 years) bitches, bitches, there were more oocytes per bitch, compared to adult (2-6.5 years) bitches, but fewer DI oocytes, and more DII and degenerate oocytes. We inferred that using donors that were post-pubertal but not senile, would assure the recovery of high-quality oocytes by the slicing method. Additional studies are required to assess the quality of oocytes collected from pre-pubertal versus post-pubertal bitches < 2 years of age.

Age Factors↗

Occurrence of foodborne pathogenic bacteria in retail prepackaged portions of marine fish in Spain.

AIMS: To survey the presence of indigenous and nonindigenous foodborne bacterial pathogens in displayed prepacked portions of fresh marine fish. METHODS AND RESULTS: A survey of 50 different samples of fresh marine fish (conger, swordfish, sole, grouper and whiting) was conducted over a period of 5 months. Trays of fillets and steaks were obtained at retail level and tested for foodborne bacterial pathogens. Vibrio cholerae and Salmonella were not detected. Two samples (4%) yielded Vibrio strains carrying a DNA fragment specific for Vibrio parahaemolyticus, but resulted negative to PCR amplification of the virulence-related tdh gene. Levels of motile Aeromonas ranging from 2.29 to 7.20 log CFU g(-1) were found in 31 (62%) samples. All fish portions were positive for the Aeromonas hlyA gene and 38 for both aerA and hlyA genes, which may contribute to diarrhoea-related virulence. The incidence of Listeria monocytogenes was 10%. Levels of Staphylococcus aureus lower than 2 log CFU g(-1) were found in 15 (30%) samples. Numbers of presumptive Clostridium perfringens ranging from 1.82 +/- 0.22 to 4.26 +/- 1.25 log CFU g(-1) were detected in 42 (84%) samples. Edwardsiella tarda was detected in two samples of grouper fillets. CONCLUSIONS: Displayed portions of raw fish carried bacteria that can cause foodborne disease. The risk posed by fresh fish when properly cooked is low, but high when destined to be consumed raw, undercooked or very lightly processed. SIGNIFICANCE AND IMPACT OF THE STUDY: This study revealed that raw fish sold in Spain could be a source of foodborne bacterial pathogens. Improvements in handling and processing are needed to minimize the prevalence of pathogenic bacteria.

Aeromonas↗

Molecular and phenotypic characterization of nonmotile Gram-negative bacteria associated with spoilage of freshwater fish.

AIMS: Characterization of nonmotile bacteria associated with freshwater fish spoilage and that phenotypically resembled Psychrobacter spp. METHODS AND RESULTS: A population of 44 nonmotile Gram-negative rods could not be assigned to the genus Psychrobacter on the basis of a definitive test (transformation assay). Conventional and commercial phenotypic systems did not help in identification. A second extensive phenotypic analysis using different temperatures and media confirmed these isolates as nonmotile although electron microscopic examination showed that all but two had one to four polar flagella and other appendages. On the basis of numerical taxonomy, this population was divided into six clusters, one of them consisting of five fluorescent strains. Sequencing of fluorescent and non fluorescent representative strains from each cluster demonstrated that strains from five clusters had between 97.8 and 98.8% sequence homology with Pseudomonas fragi IFO 3458. This and an unknown strain from deep sea were the closest organisms (80.9% sequence homology) to one aflagellated representative strain of the remaining cluster. CONCLUSIONS: Oxidase-positive, nonmotile, nonfermenter Gram-negative rods isolated from freshwater fish can be wrongly ascribed to the genus Psychrobacter. SIGNIFICANCE AND IMPACT OF THE STUDY: Molecular methods are necessary for the identification of environmental isolates and species with an incomplete phenotypic description. This work emphasizes the need for a sound description of Ps. fragi based on molecular and phenotypic characterization.

Animals↗

Fecundity and fertility of Macrobrachium amazonicum (Crustacea, Palaemonidae).

In Brazil, studies with native freshwater prawn species were discontinued due to great importance of Macrobrachium rosenbergii. Therefore, it is necessary to continue investigations about our species, in order to develop technology adequate to our reality and in a future allow prawn farmers to culture other species. The aim of this study was to determine the fecundity and fertility of Macrobrachium amazonicum captured monthly from June 1999 to June 2001 from Jaguaribe River, Itaiçaba, Ceará, Brazil. Prawns were collected using fishing net and transferred at Biological Science Laboratory, Ceara State University (Fortaleza, Ceará, Brazil). Among the ovigerous M. amazonicum females, 60 were randomly selected to determine fecundity. The eggs adhered to the pleopods were taken out and they were then placed in a Gilson solution, and then stored in alcohol 70%. Individual fecundity was determined from the total egg counting, using a stereoscopic microscope. To determine fertility, ovigerous M. amazonicum females were stored in individual 10 L-glass tanks maintained under strong aeration. After the hatching, the larvae were siphoned and counted. The data referring to total length and weight of all the females, storage date, coloration and number of eggs, weight and coloration of gonad and number of hatched larvae were noted. With respect to average fecundity (F) by length classes, the lowest and highest number of eggs observed was 696 and 1,554, respectively. As for fecundity by weight classes, the lowest number of eggs observed was 760 and the highest, 1,690. The highest number of eggs observed individually per hatching was 2,193. Average fecundity/total length (L) and average fecundity/total weight (W) may be expressed by a linear relationship. The adjusted equations are: F = -411.6 + 203.1 L (p < 0.0001) and F = 566.4 + 157.3 W (p < 0.0001), respectively. In the analysis of average fertility (N) per length classes, the lowest and highest number of larvae observed was 374 and 1,301, respectively. With respect to fertility per weight classes, the lowest number of larvae was 581 and the highest, 1,391. In this work, the maximum number of larvae observed per hatching for females kept in laboratory was 2,594. Average fertility/total length and average fertility/total weight may be expressed by a linear relationship. The adjusted equations are: N = -1042.7 + 264.9 L (p < 0.0002); N = 384.1 + 160.3 W (p < 0.003). From these results we can deduced that fecundity and fertility of M. amazonicum are lower than ones commercial species, never-the-less it can be captured during all year long. The number of captured prawns was large in the months whose level of water was low; the inverse was observed in the months that the river was with a high volume of water.

Animals↗

Comparison of three different volumes of mepivacaine in axillary plexus block using multiple nerve stimulation.

BACKGROUND: The multiple injection technique for axillary block, in which the four distal nerves of the plexus are located by a nerve stimulator and separately injected, has been shown to provide a high success rate and a short onset time. This randomized double-blind study was conducted to compare the effectiveness of three different volumes of mepivacaine 10 mg x ml(-1) in patients undergoing elective distal upper limb surgery under axillary brachial plexus block with the four-nerve approach. The number of complete sensory blocks was the primary efficacy variable. METHODS: A total of 114 adult patients were randomly allocated to receive 36 (n=38), 28 (n=38), and 20 ml (n=38) of mepivacaine 10 mg x ml(-1). In each group, volumes were equally distributed in the four nerve territories. In all patients, performance time, latency time, block characteristics, need of supplementary blocks, tourniquet tolerance, duration of analgesia, and complications were recorded. RESULTS: Complete sensory block was obtained in 97% of patients receiving a volume of 36 ml, 97% of those receiving 28 ml, and 94% of those receiving 20 ml. One patient in the group of 28 ml and five patients in the group of 20 ml experienced pain on inflation of the tourniquet. Two months after surgery, no case of postoperative neurological dysfunction was observed. CONCLUSIONS: The three volumes (38, 28, and 20 ml) of mepivacaine 10 mg x ml(-1) ensured a similar and high percentage of complete sensory blocks in axillary brachial plexus anaesthesia with nerve stimulation involving the location of four motor responses.

Adolescent↗

Foodborne pathogenic bacteria in prepackaged fresh retail portions of farmed rainbow trout and salmon stored at 3 degrees C.

Twelve lots of fresh unskinned fillets of rainbow trout (Oncorhynchus mykiss) and 10 lots of fresh sliced salmon (Salmo salar) prepacked in trays wrapped with an oxygen-permeable film were obtained immediately after packing from two supermarkets having in-plant facilities for packaging wet fish. During storage at 3 degrees C, Listeria innocua was detected in eight lots of trout fillets after 4 days storage. L. monocytogenes was recovered from a single lot also contaminated with L. innocua. Initial numbers of aeromonads were significantly (p < 0.05) lower in trout fillets (3.35 +/- 0.62 log cfu g(-1)) than in salmon slices (4.20 +/- 0.89 log cfu g(-1)). In both fish products, these bacteria significantly (p < 0.05) increased up until spoilage. Most Aeromonas spp. isolates from trout fillets were assigned to A. veronii biovar sobria HG8 (hybridisation group 8), A. caviae HG4, A. eucrenophila HG6, A. hydrophila HG1 and A. veronii biovar veronii HG10. Strains of HG12 (A. schubertii), HG4 and HG8 formed the majority of aeromonads recovered from salmon slices.

Aeromonas↗

Virulence markers in Aeromonas hydrophila and Aeromonas veronii biovar sobria isolates from freshwater fish and from a diarrhoea case.

AIMS: To evaluate the public health significance of representative strains of two Aeromonas spp., mainly from freshwater fish, on the basis of production of virulence-associated factors and presence of the haemolytic genes aerA and hlyA. METHODS AND RESULTS: Eleven strains of Aer. hydrophila, three strains of Aer. veronii biovar sobria (all from freshwater fish) and one strain of Aer. hydrophila from human diarrhoea were tested for potential virulence traits and for the presence of the haemolytic genes aerA and hlyA. Ten Aer. hydrophila isolates were aerA(+)hlyA(+) and two aerA(+)hlyA(-). Aeromonas veronii biovar sobria isolates were aerA(-)hlyA(-). Strains from the three genotypes showed enterotoxic activity in the suckling mouse assay. At 28 degrees C, four Aer. hydrophila fish strains could be considered as potentially virulent (possessing at least two of these characteristics: haemolytic, cytotoxic and enterotoxic). One Aer. veronii biovar sobria strain and the clinical isolate were cytotoxic on Vero cells. When grown at 4 degrees C, these six isolates fulfilled virulence criterion, but at 37 degrees C, only one fish strain, an Aer. hydrophila, did. CONCLUSIONS: The potential health risk derived from the presence of Aer. hydrophila and Aer. veronii biovar sobria in ice-stored freshwater fish should not be underestimated. SIGNIFICANCE AND IMPACT OF THE STUDY: Expression of virulence factors is affected by temperature incubation and not always related to the presence of haemolytic genes.

Aeromonas↗

PCR detection of potentially pathogenic aeromonads in raw and cold-smoked freshwater fish.

AIMS: Development of a PCR assay for detection of aeromonads carrying the hlyA and/or aerA genes in fish. METHODS AND RESULTS: The protocol involves an overnight selective enrichment step in tryptic soy broth yeast extract containing 10 microg ml(-1) of ampicillin followed by extraction of DNA and PCR amplification of two haemolysin genes that contribute to the virulence of Aer. hydrophila. This procedure can detect initial populations of 1-10 cfu g(-1) within 24 h in artificially contaminated samples. In naturally contaminated fish, both genes were detected in 13 out of 14 fresh fish lots (aeromonads levels between < 1 and 5.42 log cfu g(-1)) and in 4 out of 16 lots of vacuum-packed cold-smoked fish (aeromonads levels between < 1 and 3.37 log cfu g(-1)). Before enrichment, dominant species were Aer. hydrophila HG1 (aerA+hlyA+), Aer. bestiarum HG2 (aerA+hlyA+) and Aer. caviae HG4 (aerA-hlyA-). After enrichment, Aer. hydrophila HG1 (aerA+hlyA+) was dominant. CONCLUSIONS: Fresh fish and even smoked fish carry hlyA+ and/or aerA+ aeromonads that can be detected by PCR within 24 h. SIGNIFICANCE AND IMPACT OF THE STUDY: The PCR assay described offers considerable potential as a rapid method with specificity, sensitivity and simplicity.

Aeromonas↗

Withdrawing and withholding life support in the intensive care unit: a Spanish prospective multi-centre observational study.

OBJECTIVE: To determine how frequently life support is withheld or withdrawn from adult critically ill patients, and how physicians and patients families agree on the decision regarding the limitation of life support. DESIGN: Prospective multi-centre cohort study. SETTING: Six adult medical-surgical Spanish intensive care units (ICUs). PATIENTS AND PARTICIPANTS: Three thousand four hundred ninety-eight consecutive patients admitted to six ICUs were enrolled. MEASUREMENTS AND RESULTS: Data collected included age, sex, SAPS II score on admission and within 24 h of the decision to limit treatment, length of ICU stay, outcome at ICU discharge, cause and mode of death, time to death after the decision to withhold or withdraw life support, consultation and agreement with patient's family regarding withholding or withdrawal, and the modalities of therapies withdrawn or withheld. Two hundred twenty-six (6.6%) of 3,498 patients had therapy withheld or withdrawn and 221 of them died in the ICU. Age, SAPS II and length of ICU stay were significantly higher in patients dying patients who had therapy withheld or withdrawn than in patients dying despite active treatment. The proposal to withhold or withdraw life support was initiated by physicians in 210 (92.9%) of 226 patients and by the family in the remaining cases. The patient's family was not involved in the decision to withhold or withdraw life support therapy in 64 (28.3%) of 226 cases. Only 21 (9%) patients had expressed their wish to decline life-prolonging therapy prior to ICU admission. CONCLUSIONS: The withholding and withdrawing of treatment was frequent in critically ill patients and was initiated primarily by physicians.

Adult↗

Surface mycoflora of a Spanish fermented meat sausage and toxigenicity of Penicillium isolates.

The surface mycoflora of "chorizo de Cantimpalos", a Spanish variety of fermented meat sausage characterised by a natural white covering, has been investigated. Among 54 mould strains isolated, 38 belonged to Penicillium subgenus Penicillium. The major species found (18 isolates) was identified as Penicillium commune, and the other dominant species (13 isolates) was identified as P. olsonii. None of the P. olsonii isolates produced cyclopiazonic acid, mycophenolic acid, roquefortine C. patulin or ochratoxin A, but all P. commune isolates produced cyclopiazonic acid. Toxicity to Artemia salina larvae was very high for all P. commune isolates investigated, while no isolates of P. olsonii studied were toxic to these crustaceans. The results may assist in selection of nontoxic strains, which could be used as surface starters in the manufacture of this type of sausage. The apparent inability to produce penicillin is a valuable characteristic to take into account in the selection process.

Animals↗

Anaplastic meningioma: case report.

Intracranial meningiomas continue to challenge our best clinical efforts to eliminate them once discovered and deemed appropriate for treatment. Malignant meningiomas constitute 10% to 15% of all meningiomas and limited information exists regarding adjuvant treatment. The external whole brain irradiation is recommended. Traditional chemotherapy has proven ineffective; thus, new chemotherapeutic agents and new methods of delivery should be developed. Immunotherapy may be considered for patients with malignant meningiomas when all others previous treatment have failed. We report a case of anaplastic papillary meningioma. A 67-year-old man presented with partial complex seizures, headache and aggressiveness. A computerized tomography and magnetic resonance image demonstrated a large left temporo-occipital mass with diffuse contrast enhancement and extensive surrounding edema. A left temporo-occipital flap was performed. The tumor and the infiltrated dura were radically removed. Postoperatively, the patient remained neurologically intact. The treatment was complemented by external whole brain radiation.

Aged↗

Mesophilic aeromonads in wild and aquacultured freshwater fish.

Numbers and species of motile Aeromonas were determined in freshly caught freshwater fish, in the surrounding environment, and also during iced chilled storage of fish specimens. Although no significant differences were observed in water samples, initial levels for skin, gill, and intestines were significantly lower in farmed rainbow trout (Oncorhynchus mykiss) than in wild brown trout (Salmo trutta) and pike (Esox lucius). During storage of wild specimens, naturally occurring aeromonads grew fairly well on the surfaces of skin and body cavity. Of 171 strains assigned to the genus Aeromonas, 88% were identified to phenospecies and putative genospecies level by using comprehensive biochemical schemes. The isolates were allocated to putative hybridization groups (HGs) 1 and 3 Aeromonas hydrophila (29%); putative HG 8 Aeromonas veronii biovar sobria (19%); putative HG 2 Aeromonas bestiarum (18%); putative HG 9 Aeromonas jandaei (16%); putative HGs 4 and 5a Aeromonas caviae (2%); putative HG 12 Aeromonas schubertii (2%); and putative HG 11 (unnamed, 0.6%). The remaining 20 isolates (12%) resembled A. schubertii but could not be allocated to currently recognized phenospecies or to putative HGs. Although cultured rainbow trout yielded strains of putative HGs 1, 4, and 8, which appear to be of major clinical importance, most isolates assigned to putative HGs 1 and 8 were recovered from pike. Differences among HGs found in wild animals could be related to their origin (unpolluted rivers for brown trout and urban rivers for pike). The recovery of these aeromonads species was not related to sampling site. The initial levels of motile aeromonads, their behavior during storage, and the strong potential spoilage activity of most isolates confirm that these bacteria can contribute to deterioration of iced wild freshwater fish. Although adequate cooking would inactivate motile aeromonads, the high incidence of isolates belonging to gastroenteritis-associated HGs should be regarded as a potential health concern, particularly for susceptible populations when there is a possibility of cross-contamination.

Aeromonas↗

Bacteriological quality of aquacultured freshwater fish portions in prepackaged trays stored at 3 degrees C.

Fresh trout fillets and salmon slices packed in trays were obtained from two multinational chain supermarkets and evaluated for freshness and bacteriological quality immediately after packaging and during storage at 3 degrees C. Initial aerobic counts at 30 and 25 degrees C were significantly (P < 0.05) lower in trout fillets (5.27 +/- 0.57 and 4.87 +/- 0.80 log CFU/g, respectively) than in salmon slices, where levels in excess of 6 log CFU/g were found. In both products, initial Enterobacteriaceae counts were slightly higher than 3 log CFU/g and increased significantly during shelf life by approximately 3 log CFU/g. Most of the enterobacteria were identified as Citrobacter freundii, Hafnia alvei, and Enterobacter cloacae. On day 0, most probable number (MPN) counts of total and fecal coliforms were not significantly different, numbers of the latter group being approximately 4 MPN/g. Escherichia coli was only detected when fish was spoiled. Although initial presumptive Staphylococcus aureus counts were approximately 3 log CFU/g, only 4 of 84 selected colonies belonged to this species. Neither Salmonella nor antimicrobial residues were detected in any sample. Ethanol content in salmon slices did not significantly (P > 0.05) increase until they became inedible. Significant correlation (r = +0.72, P < 0.05) was observed between this chemical index and viable counts at 30 degrees C only when salmon slices were inedible. Trout fillets were acceptable for 7 days, and salmon slices showed signs of spoilage after 4 days. Although public health concerns associated with packed trout and salmon appear to be minimal, data on sensory quality, shelf life, and total viable and Enterobacteriaceae counts strongly suggest the need to improve the quality control systems used by European multinational retailers, especially for imported salmon.

Animals↗

Psychrobacters and related bacteria in freshwater fish.

Three phenotypic identification systems were employed to identify 106 strains of gram-negative, nonmotile, aerobic bacteria obtained during iced storage of wild (Salmo trutta and Esox lucius) and farmed (Oncorhynchus mykiss) freshwater fish. Using diagnostic tables and computer-assisted identification, the isolates were Psychrobacter (64 strains), Acinetobacter (24 strains), Moraxella (6 strains), Chryseobacterium (5 strains), Myroides odoratus (2 strains), Flavobacterium (1 strain), Empedobacter (1 strain), and unidentified (3 strains). Overall similarities of all strains were determined for 108 characters by numerical analysis (simple matching coefficient of similarity [S] and clustering by unweighted pair group average linkage [UPGMA]). At the 77% similarity level, 92 strains formed nine major clusters (3 or more strains) and four small clusters (2 strains). Cluster 1 (25 isolates divided into two main subclusters) could be assigned to Psychrobacter phenylpyruvicus, clusters 2 and 3 (26 isolates) were designated as Psychrobacter immobilis, and clusters 4 (3 isolates) and 7 (4 isolates) were identified as Psychrobacter urativorans and Psychrobacter spp., respectively. Clusters 5 (five isolates), 6 (three isolates), and 9 (five isolates) were labeled as Acinetobacter spp., Acinetobacter johnsonii, and Acinetobacter lwoffii, respectively. Cluster 8 (12 isolates), with a high resemblance to Thornley's phenon 4 (a heterogeneous group of bacteria isolated from poultry and related to Acinetobacter), remained unnamed. The restriction pattern was identical for strains grouped into clusters 2 and 3 (P. immobilis) but was different for the remaining Psychrobacter isolates. A large proportion of isolates belonging to the family Moraxellaceae were closely related. Psychrobacters and A. johnsonii were present in freshly caught fish and river water. In the latter stages of storage, P. phenylpyruvicus and acinetobacters tended to decrease, whereas P. immobilis increased.

Animals↗

Hemolytic activity and siderophore production in different Aeromonas species isolated from fish.

The hemolytic activity and siderophore production of several strains of motile aeromonads were determined. The hemolytic activity of Aeromonas caviae and Aeromonas eucrenophila was enhanced after trypsinization of the samples. The enhancement of hemolysis was observed in strains that carried an aerolysin-like gene, detected by a PCR procedure. Siderophore production was demonstrated in all but one strain of Aeromonas jandaei. No apparent relationship was observed between the presence of plasmid DNA and hemolysis or siderophore production.

Aeromonas↗

Hemolytic and elastolytic activities influenced by iron in Plesiomonas shigelloides.

The aim of this study was to determine the presence of hemolytic and elastolytic enzymes in several strains of Plesiomonas shigelloides in relation to the availability of iron in culture media. Hemolytic activity and elastolytic activity were detected in strains of P. shigelloides and were enhanced when the strains were grown in an iron-depleted medium and lost after thermal treatment at 100 degrees C for 10 min. Also, elastolytic activity was inactivated by phenylmethyl sulfonyl fluoride, an inhibitor of serine proteases. Hemolytic activity was detected extracellularly in cell-free supernatants, whereas elastin degradation activity was cell associated. Both activities may be related to the virulence of P. shigelloides.

Culture Media↗

Simulated surgery on computed tomography and magnetic resonance images: an aid for intraoperative radiotherapy.

Intraoperative radiotherapy (IORT) is a relatively new technique in which irradiation with electrons is performed during an open surgery procedure. This approach poses significant problems in obtaining accurate dosimetry, since neither the pre- nor the postoperative patient images actually matches the irradiation field. Our objective was to implement a software tool able to provide an estimate of the dose distribution, overcoming the problem of the geometrical mismatch between the images and the surgical field during the irradiation. The program was developed in the C programming language, on a noncommercial version of a Philips EasyVision workstation. The application allows to create a new data set by manipulating the preoperative computed tomography and magnetic resonance images in order to simulate the final geometry of the surgical area during the IORT procedure. The exact dose distribution can then be calculated by transferring these new images to a standard radiotherapy planning system. Also an approximate dose distribution can be quickly displayed by superimposing isodose curves obtained from a water phantom. The proposed approach introduces a helpful tool for dosimetry and planning in IORT protocols, improving their accuracy and safety and allowing for more objective quality control and patient follow-up.

Brain Neoplasms↗