Concentration of some toxic elements in Oryctolagus cuniculus and in its intestinal cestode Mosgovoyia ctenoides, in Dunas de Mira (Portugal)

The need for sentinel organisms reflecting small-scale changes in heavy metal pollution of different habitats has been previously stated and the role of terrestrial mammalian parasites has been pointed out as an important field of research aiming at the potential use of parasitic models as bioindicators. The scope of the present study was to assess the concentration of some toxic (Cd, Pb, As and Hg) elements in Dunas de Mira (Natura 2000 PTCON055) while testing the model constituted by the wild rabbit (Oryctolagus cuniculus Linnaeus, 1758) and its intestinal cestode parasite Mosgovoyia ctenoides Railliet, 1890 as potential bioindicators. Wild rabbits were harvested by hunters and analysed for intestinal cestodes. Samples of kidney, liver, intestinal mucosa, muscle of host and also M. ctenoides were taken and deep-frozen for posterior element analysis by ICP-MS. In general, levels of contamination in rabbit tissues were found to be low although some of the elements were detected in higher quantities when compared to other previous reports for wildlife in Europe. The highest quantity of Pb was found in rabbit muscle (3.81 ppm) while highest Cd and Hg values were found in kidney (1.02 and 0.08 ppm). Significant linear relationships were found between Pb concentration in the parasite and Pb concentration in kidney (P=0.0047), muscle (P=0.0002) and intestinal mucosa (P=0.0181) and between As concentration in the parasite and As concentration in liver (P=0.0024), kidney (P=0.0010), muscle (P=0.0003) and intestinal mucosa (P=0.0047). The most significant relationships for Pb and As were detected between element concentration in the cestode and in host muscle. However, maximum Pb and As concentrations in M. ctenoides were only twice as high as those found for rabbit kidney and therefore it is not possible to confirm the role of the model O. cuniculus/M. ctenoides as a promising bioindicator system unlike other mammalian host/cestode models tested in other studies. The contrasting results might be due to differences in the absorption processes in the tegument of different cestode families. Furthermore, the large size of the cestodes used in the present study might also explain the relatively low element concentration values obtained.

Evaluation of paediatric tolerance to an extract of Alternaria alternata under two treatment regimes. A multicentre study

In order to evaluate the efficacy and safety of an extract of Alternaria alternata in a paediatric population, a two phase study plan has been elaborated that in the first place consists of a retrospective analysis of tolerance under the standard treatment regimes used by the clinical groups involved. This was achieved by analysing the records of 94 patients that have been treated with this extract, these being consecutive patients included at 7 clinics over a period of 6 months. Two regimes were used: a conventional short regime of 7 doses and a cluster regime. Under neither of these two regimes were any serious reactions registered. The percentage of local reactions was significantly greater using the short conventional regime than with the cluster regime (1.9% and 0.4% respectively, p = .035). In contrast, no significant differences were observed with respect to the systemic reactions (0.5% and 1.2%), these percentages also being similar to those registered with other extracts in which identical regimes have been used. In conclusion, we can confirm that a very satisfactory tolerance profile was observed, with the advantage that through using shorter regimes than the conventional regime of 13 doses, a considerable saving is made both in the number of visits and the doses necessary to reach the maintenance dose.

Cadmium and lead concentrations in Gallegoides arfaai (Cestoda: Anoplocephalidae) and Apodemus sylvaticus (Rodentia: Muridae) from Spain

Information on parasites of vertebrates living in terrestrial ecosystems as sentinels for heavy metal environmental pollution is scarce. The aim of the present study was to assess the concentration of cadmium and lead using the model Apodemus sylvaticus/Gallegoides arfaai in order to test the potential suitability of G. arfaai as a sentinel organism for lead and cadmium under natural field conditions. Samples of 15 A. sylvaticus as well as whole specimens of G. arfaai were analysed for both elements by inductively coupled plasma mass spectrometry. The level of cadmium in G. arfaai was always much lower than in the tissues of A. sylvaticus. Contrarily, values for lead in G. arfaai were found to be 6, 20 and 24-fold higher than in the kidney, liver and muscle of A. sylvaticus. We propose the model A. sylvaticus/G. arfaai as a promising bioindication system to evaluate environmental lead exposure in terrestrial habitats, especially for non-urban areas.

Topographical localisation of cagA positive and cagA negative Helicobacter pylori strains in the gastric mucosa; an in situ hybridisation study

BACKGROUND

The cagA gene is a marker for the presence of the cag pathogenicity island, and the presence of cagA positive strains of Helicobacter pylori can identify individuals with a higher risk of developing gastrointestinal diseases.

AIMS

To study the interaction between H. pylori cagA(+) and cagA(-) strains and the gastric mucosa.

METHODS

Patients with H. pylori associated gastritis and peptic ulcers were studied. Biopsies were obtained from the antrum, corpus, fundus, and incisura for H pylori culture, and for in situ hybridisation studies. From each biopsy, multiple single H. pylori colonies were isolated and propagated for DNA isolation, and cagA was detected by the polymerase chain reaction (PCR). For in situ detection of H. pylori an oligonucleotide specific for an H. pylori common antigen and an oligonucleotide specific for cagA were used as probes. Biotinylated probes were incubated with biopsy sections, developed with streptavidin-horseradish peroxidase, and amplified with the tyramide system.

RESULTS

PCR results for cagA in isolated colonies confirmed the in situ hydridisation studies. In situ hybridisation identified cagA(+) bacteria in patients with cagA(+) isolates; cagA(-) bacteria in patients with cagA(-) isolates, and cagA(+) and cagA (-) bacteria in patients with both cagA(+) and cagA(-) isolates. CagA(-) bacteria usually colonised the mucous gel or the apical epithelial surface, whereas cagA(+) bacteria colonised the immediate vicinity of epithelial cells or the intercellular spaces.

CONCLUSIONS

These results document a different in vivo interaction between H. pylori cagA(+) or cagA(-) strains and the gastric mucosa.

Equifrequency surfaces in a two-dimensional GaN-based photonic crystal

We established the angular conditions that maintain the quasi-phase matching conditions for enhanced second-harmonic generation. To do that, we investigated the equifrequency surfaces of the resonant Bloch modes of a two-dimensional periodic, hole-array photonic crystal etched into a GaN/sapphire epitaxial structure. The equifrequency surfaces exhibit remarkable shapes, in contrast to the simpler surfaces of a one-dimensional structure. The observed anisotropy agrees well with the surfaces calculated by a scattering matrix method. The equifrequency surfaces at fundamental and second-harmonic frequencies provide the values of polar and azimuthal angles that maintain quasi-phase matching conditions for enhanced second-harmonic generation over an extended tuning range. The predicted values for quasi phase-matching conditions show that frequency tuning for the two-dimensional case covers an about two times larger fractional bandwidth relative to the one-dimensional case.

[Waterborne outbreak of gastroenteritis transmitted through the public water supply]

INTRODUCTION

The chlorination of public water supplies has led researchers to largely discard drinking water as a potential source of gastroenteritis outbreaks. The aim of this study was to investigate an outbreak of waterborne disease associated with drinking water from public supplies.

METHODS

A historical cohort study was carried out following notification of a gastroenteritis outbreak in Baqueira (Valle de Arán, Spain). We used systematic sampling to select 87 individuals staying at hotels and 67 staying in apartments in the target area. Information was gathered on four factors (consumption of water from the public water supply, sandwiches, water and food in the ski resorts) as well as on symptoms. We assessed residual chlorine in drinking water, analyzed samples of drinking water, and studied stool cultures from 4 patients. The risk associated with each water source and food type was assessed by means of relative risk (RR) and 95% confidence intervals (CI).

RESULTS

The overall attack rate was 51.0% (76/149). The main symptoms were diarrhea 87.5%, abdominal pain 80.0%, nausea 50.7%, vomiting 30.3%, and fever 27.0%. The only factor associated with a statistically significant risk of disease was consumption of drinking water (RR = 11.0; 95% CI, 1.6-74.7). No residual chlorine was detected in the drinking water, which was judged acceptable. A problem associated with the location of the chlorinator was observed and corrected. We also recommended an increase in chlorine levels, which was followed by a reduction in the number of cases. The results of stool cultures of the four patients were negative for enterobacteria.

CONCLUSIONS

This study highlights the potential importance of waterborne outbreaks of gastroenteritis transmitted through drinking water considered acceptable and suggests the need to improve microbiological research into these outbreaks (viruses and protozoa detection).

High Incidence of Non-B and Recombinant HIV-1 Strains in Newly Diagnosed Patients in Galicia, Spain: Study of Genotypic Resistance

The objectives of this study are to describe the incidence of non-B and recombinant HIV-1 strains in newly diagnosed HIV-1 infections in Galicia, northwest of Spain, during a 2-year period (May 2000 to June 2002), and the frequency of resistance-associated mutations in reverse transcriptase (RT) and protease (PR) genes, analysing the polymorphisms more frequently detected in non-B and recombinant viruses. All newly diagnosed HIV-1-infected patients attending the nine public hospitals of the seven main cities of Galicia were included in this study. RT, PR and V3 regions from HIV-1 RNA plasma were amplified and sequenced, being the corrected sequences sent to the Stanford HIV RT and Protease Sequence Database. Nineteen of 85 patients (22.3%) were infected by non-B or recombinant viruses: three subtype C, two G, one F1, one Dpol/A1V3, five CRF02_AG, one CRF14_BG, five BGpol/BV3 and one UKpol/UV3 (U, unknown fragment). Eleven of these 19 patients (57.9%) were foreign individuals living in Galicia infected through heterosexual contact, and the other eight (42.1%) were Spanish intravenous drug users who had shared injection equipment. Five of 85 patients (5.9%), all infected with B subtype viruses, showed resistance-associated mutations in RT (M184V, M41L, L210W, T215Y/D and K219Q). In one patient (1.2%) infected with a subtype G strain, resistance-associated mutations in PR (K20I+M36I+M46I+V82I) were detected. In subtype B viruses resistance mutations in PR were not detected. Several polymorphisms in RT: D123S, Q174K, D177E, T200A, V245Q, and PR: I13V, K20I, M36I, R41K, H69K, L89M were detected more frequently in non-B and recombinants than in B strains ( P<0.01 to P<0.001). This study reports a high incidence (22.3%) of newly diagnosed patients infected by different non-B and recombinant HIV-1 strains, in a geographical area of Spain, showing also a high frequency of polymorphisms in RT and PR genes.

[Assessment of the nutritional status of elderly patients treated at a home-hospital unit]

GOALS

To establish the nutritional status of our elderly patients, assess the usefulness of the various anthropometric and biochemical parameters as markers of malnutrition and to determine which of the variables studied have the greatest correlation with malnutrition.

SCOPE

Home Hospital Unit of the Arnau de Vilanova Teaching Hospital in Lerida.

PATIENTS

57 patients > or = 60 years. Mean admission to our unit: 12.1 days.

VARIABLES

Age, sex, groups by treatment complexity, associated pathology, diagnosis, reason for admission, duration of stay in hospital, surgery performed, complications during the stay at the Home Hospital Unit, weight, height, PCT, AC, BMI, albumin, haemoglobin and RTL.

RESULTS

Patients of great age present lower levels of serum albumin (p < 0.005), total proteins (p < 0.001), transferrin (p < 0.03), haemoglobin (p < 0.02) and RTL (p < 0.04) than "younger" elderly patients. Serum albumin and haemoglobin are lower in patients in a complicated post-surgical condition (p < 0.04 and p < 0.02, respectively) and this group is the one with the longest stays (p < 0.001). Those patients with hypoalbuminaemia (74.1%) present lower PCT and RTL (p < 0.02) and a longer stay in hospital (p < 0.01) than those with normal levels of albumin in blood. Patients with anaemia (63.3%) present a lower RTL (p < 0.01) and a greater hospitalization time than those without anaemia. Total proteins (p < 0.0001), albumin (p < 0.004), transferrin (p < 0.003) and RTL (p < 0.005) correlate negatively with age. Albumin (p < 0.001), haemoglobin (p < 0.006) and RTL (p < 0.0001) present a negative correlation with length of hospital stay.

CONCLUSION

The prevalence of global malnutrition is high (51% moderate-severe). The nutritional status worsens with age. The length of hospitalization increases gradually with age, with deteriation in the nutritional status and with complexity of the treatment provided.

Factors promoting colonization by legionellae in residential water distribution systems: an environmental case-control survey

As part of a case-control study of community-acquired Legionnaires' disease, several factors related to residential water distribution systems and public drinking water systems were studied in the homes of 124 patients with community-acquired Legionnaire's disease and in the homes of 354 controls. The presence of water reservoirs and hot water tanks was studied in residential systems. Factors such as deficient chlorine levels, pipe repairs and other work, water flow interruptions, the use of alternative water sources, inadequate cleaning operations in public water reservoirs, and the position of the home within the public network (and whether this location constituted an endpoint) were studied in public water supply systems. Levels of legionellae in domestic water samples were also measured. Although the use of water reservoirs and hot water tanks promotes colonization by legionellae in residential systems, none of the variables studied seems to increase the incidence of community-acquired Legionnaires' disease.

Bacteriology of anal fistulae

OBJECTIVE

To evaluate by bacteriological analysis the possible relationship between the chronicity of perianal fistulae and the presence of probable permanent infection of the fistulae.

MATERIAL AND METHODS

The study included 27 patients, 21 men and 6 women who had undergone surgery for chronic perianal fistulae type II (according to the Parks classification). A total of 27 samples of their fistulous tracts were sent to the microbiology department for the identification of germs. All samples were taken from the theatre and delivered to the laboratory in the same manner. They were then processed under de same conditions in terms of dilutions, inoculation and culture mediums used for the identification of germs in the tracks of the fistulae.

RESULTS

A total of 45 were isolated from 21 different species of microorganisms. Most samples (78.26%) had polymicrobic growth. The predominant species were: Escherichia coli (45.45%), Bacteroides fragilis (16.66%), Staphylococcus aureus (12.12%) and Streptococcus viridans (12.12%). No Mycobacteria were found in any specimen.

CONCLUSIONS

Anal fistulae can be colonized by poli- or mononormal intestinal or skin microbacterial flora or a combination of both. This report suggests that neither the type or the number of germs its related to the chronicity of cryptoglandular anal fistulae.

X-ray imaging measurements of capsule implosions driven by a Z-pinch dynamic hohlraum

The radiation and shock generated by impact of an annular tungsten Z-pinch plasma on a 10-mm diam 5-mg/cc CH(2) foam are diagnosed with x-ray imaging and power measurements. The radiative shock was virtually unaffected by Z-pinch plasma instabilities. The 5-ns-duration approximately 135-eV radiation field imploded a 2.1-mm-diam CH capsule. The measured radiation temperature, shock radius, and capsule radius agreed well with computer simulations, indicating understanding of the main features of a Z-pinch dynamic-hohlraum-driven capsule implosion.

Screening for adenylosuccinate lyase deficiency: clinical, biochemical and molecular findings in four patients

Adenylosuccinate lyase deficiency is an autosomal recessive defect of purine metabolism. Succinyladenosine (S-Ado) and succinylaminoimidazole carboxamide riboside (SAICAr) are the disease marker metabolites in physiological fluids. The Bratton-Marshall test for detection of SAICAr in urine has been added to the selective screening for inborn errors of metabolism that is carried out in our lab. During the last three years, around 2,000 patients have been screened by this method, resulting in the detection of four new cases with this disease. They all presented with severe psychomotor delay, hypotonia and refractory epilepsy since the neonatal period. The S-Ado/SAICAr ratio in cerebrospinal fluid was below 2, indicating that they correspond to the most severe form of the disease. New missense mutations were found in a heterozygous fashion in three patients. The study of purines in all patients with neurological disease of unknown etiology is highly recommended.

Transmission dynamics of Cryptosporidium in primates and herbivores at the Barcelona zoo: a long-term study

Factors influencing the transmission of Cryptosporidium in primates and herbivores housed at the Barcelona zoo have been analyzed. The relationship between continuous and discontinuous oocyst shedding, both animal housing conditions and abiotic factors (seasonality, humidity, temperature) was examined to explain the epizootiology of the protozoan. Thirty six fecal samples from each of 11 primates (Pongidae, Cebidae, Cercopithecidae and Lemuridae) and 22 herbivores (Elephantidae, Camelidae, Cervidae, Giraffidae and Bovidae) were examined over the period of 1 year. The parasite transmission was based on the chronic infection status of some animals serving as a source of successive reinfection for other animals. The environmental temperature and humidity (seasonality), the physical features of the facilities, the vicinity of the animals and the physiological status induced by captivity contributed to transmission. The long-term character of this study was essential for obtaining these results and interpreting the complex relationships.

The orientation of the antibiotic peptide maculatin 1.1 in DMPG and DMPC lipid bilayers. Support for a pore-forming mechanism

Maculatin 1.1 is an antimicrobial peptide isolated from the Australian tree frog Litoria genimaculata that adopts an amphipathic, alpha-helical structure in solution. Its orientation and conformation when incorporated to pre-formed DMPG (1,2-dimyristoyl-sn-glycero-3-phosphoglycerol) and DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) vesicles was determined using polarised Fourier transform infrared-attenuated total reflection infrared and deuterium exchange experiments. For DMPG membranes, our results show insertion of 70% of the maculatin 1.1 molecules, with an angle of insertion of approximately 35 degrees to the membrane normal and with a predominant alpha-helical structure. These results suggest that maculatin 1.1 acts through a pore-forming mechanism to lyse bacterial membranes. A similar degree of insertion in DMPG (65%) and alpha-helical structure was observed for a biologically inactive, less amphipathic maculatin 1.1 analogue, P15A, although the helix tilt was found to be greater (46 degrees) than for maculatin 1.1. Similar experiments performed using DMPC liposomes showed poor insertion, less than 5%, for both maculatin 1.1 and its analogue. In addition, the shape of the amide I band in these samples is consistent with alpha-helix, beta-structure and disordered structures being present in similar proportion. These results clearly show that maculatin 1.1 inserts preferentially in negatively charged membranes (DMPG) which mimic the negatively charged membrane of Gram-positive bacteria. We attribute the high percentage of insertion of the biologically inactive analogue in DMPG to the fact that its concentration on the membrane surface in our experiments is likely to be much higher than that found in physiological conditions.

Prognostic factors in thymic epithelial neoplasms

OBJECTIVES

The primary thymic epithelial neoplasms (PTENs) are uncommon tumours with a broad spectrum of both biological and morphological features. The aim of this study is to analyse the prognostic factors that influence survival.

METHODS

Forty-four patients with a complete follow-up were analysed. Nine patients (20.5%) were asymptomatic, the most common symptoms in the rest being myasthenia gravis and dyspnoea. All the patients underwent surgery, 30 cases (68.2%) receiving total thymectomy and the rest a partial resection or biopsy. Marino-Müller's histological classification showed the mixed type to be the most common (52.3%). Clinical staging was done according to the Masaoka classification, which gave the most common stage as stage III (34.1%).

RESULTS

Twelve patients died during a mean follow-up of 8.2 +/- 3.5 years. The accumulated survival rate was 77% at 5 years and 60% at 10 years. Analysis of the survival curves shows significant differences (P<0.05) when considering surgical technique, clinical staging and histological subtype. The multivariate analysis shows the only parameters with prognostic significance in PTENs to be clinical staging and histological type (P<0.001).

CONCLUSIONS

The most important prognostic factors in PTENs are Masaoka's clinical staging and Marino-Müller's histological subtype.