Production and partial characterization of a beta-amylase by Xanthophyllomyces dendrorhous

AIMS

The characterization of a beta-amylase produced by Xanthophyllomyces dendrorhous.

METHODS AND RESULTS

Growth in different culture media showed that X. dendrorhous produces an amylase whose synthesis is repressed by the carbon source and induced by starch and maltose. Enzymatic assays using substrates with different degrees of polymerization together with viscosity experiments revealed that the enzyme was beta-amylase. According to the biochemical characterization, the enzyme has a molecular weight of 240 kDa and a Km of 1.35 mg ml-1. The optimum pH and temperature were 5.5 and 50 degrees C, respectively. Using different inhibitors of the enzymatic activity it was shown that cysteine, tryptophan and serine are essential amino acids for catalysis.

CONCLUSIONS

Xanthophyllomyces dendrorhous CECT1690 synthesizes and secretes beta-amylase that could be a by-product, in addition to carotenoid pigments, in the fermentation downstream.

SIGNIFICANCE AND IMPACT OF THE STUDY

The beta-amylase produced by X. dendrorhous may have certain industrial applications.

Inverted papilloma of the sphenoid sinus

Inverted nasosinusal papilloma is a benign tumor accounting for less than 4% of all nasal masses. The lesion originates in the mucosa lining the nasal cavities, the locations in decreasing order of frequency being the lateral wall of the nasal fossa, ethmoid sinus, and maxillary sinus; the sphenoid sinus is only rarely affected. Despite its benign histology, the tumor shows aggressive behavior and can be associated to carcinomas. Surgery is therefore indicated in such cases.

Cloning and expression of Blo t 1, a novel allergen from the dust mite Blomia tropicalis, homologous to cysteine proteases

BACKGROUND

House dust mite allergens have been shown to be a very important stimulus in the causation of asthma and triggers for the exacerbation of symptoms. Therefore, characterization of mite-derived allergens at the molecular level is an important step for the development of effective diagnostic and therapeutic approaches, as well as for epidemiological studies.

OBJECTIVE

To clone, express and characterize at the molecular level the cysteine protease from Blomia tropicalis (Bt).

METHODS

A full-length cDNA encoding Blo t 1 was cloned from a Bt cDNA library using a PCR and RACE-based strategy. The cDNA was PCR-amplified, sequenced and subcloned into a prokaryotic expression vector. The allergenicity of the recombinant Blo t 1 was evaluated for IgE reactivity by Western blot.

RESULTS

Blo t 1 cDNA encodes a 221 amino acids polypeptide with an estimated molecular weight of 25 kDa. The recombinant protein is 35% identical to other mite cysteine proteases. Recombinant Blo t 1 (rBlo t 1) bound IgE from 62% of Bt skin test-positive serum. Dermatophagoides pteronyssinus (Dp) skin test-positive sera did not react with rBlo t 1, indicating the possible presence of unique IgE epitopes on the rBlo t 1 molecule. A three-dimensional image of Blo t 1, constructed based on predicted analysis, showed conserved secondary and tertiary structure with other cysteine proteases.

CONCLUSION

We report the cloning, expression and IgE reactivity of Blo t 1, a novel allergen from the domestic mite Blomia tropicalis (Bt), highly homologous to cysteine proteases. This putative cysteine protease, designated Blo t 1, may play a major role as an immunodominant allergen involved in dust mite-specific IgE-mediated hypersensitivity.

Regulation of mu-opioid receptors, G-protein-coupled receptor kinases and beta-arrestin 2 in the rat brain after chronic opioid receptor antagonism

The aim of this study was to analyse the biochemical and behavioural consequences of chronic treatment with opioid receptor antagonists in rats. We have evaluated the respiratory depressant and antinociceptive effects of the mu-opioid agonist sufentanil, the density of brain mu-opioid receptors, and the expression of G-protein-coupled receptor kinases and beta-arrestin 2 in cerebral cortex and striatum, following sustained opioid receptor blockade. Our results demonstrate that 24 h after interruption of 7 days chronic infusion of naltrexone (120 microg/h), the respiratory depressant potency of the mu-opioid receptor agonist sufentanil was increased to a similar extent as the antinociceptive potency (about three-fold). This was accompanied by mu-opioid receptor up-regulation in several areas of the rat brain associated with opioid control of pain perception and breathing. Moreover, chronic treatment with either naltrexone (120 microg/h) or naloxone (120 microg/h) caused significant increases in the expression levels of G-protein-coupled receptor kinases types 2, 3, and 6, and of beta-arrestin 2 in brain cortex and striatum. Together our data suggest an increased constitutive receptor activity secondary to mu-opioid receptor up-regulation following chronic antagonist treatment.

[New procedure for the early detection and control of hospital malnutrition]

The serious problem of hospital undernutrition is still being underestimated by medical staff of modern hospitals, despite its impact on clinical evolution and hospitalisation costs. The actual system used to detect undernutrition in hospitals depends on doctor's sensitivity and not even the 10% of the cases that require intervention are detected. The screening methods developed so far are not useful for daily clinical practice due to their low effectiveness/cost ratio. We present a screening method that allows an automatic daily assessment of nutritional status, of all inpatients that undergo routine analysis. The system is based on a computer application that compiles daily all patients' information available in hospital databases, through the internal network. It automatically assesses the nutritional status of patients taking into account laboratory information concerning albumin, total cholesterol and total lymphocyte count. This tool also provides diagnostic and patients data for physicians' usage. The screening method has been validated, obtaining a sensitivity of 92.3 and specificity of 85.0, considering only laboratory information. This is an efficient tool for early detection and permanent control of hospital undernutrition, with the suitable characteristics for these screening functions, such as its sensitivity, specificity, universality, economy and harmlessness, as well as a great versatility for undertaking a high number of studies regarding the hospital undernutrition problem. We trust that working with it we will obtain a remarkable welfare improvement as well as make aware to people in charge of Public Health of the magnitude of the undernutrition's derived consequences of hospital's in-patients, and after discharge.

Molecular and kinetic study of catalase-1, a durable large catalase of Neurospora crassa

Catalase-1 (Cat-1), one of the two monofunctional catalases of Neurospora crassa, increases during asexual spore formation to constitute 0.6% of total protein in conidia. Cat-1 was purified 170-fold with a yield of 48% from conidiating cultures. Like most monofunctional catalases, Cat-1 is a homotetramer, resistant to inactivation by solvents, fully active over a pH range of 4-12, and inactivated by 3-amino-1,2,4-triazole. Unlike most monofunctional catalases, Cat-1 consists of 88 kDa monomers that are glycosylated with alpha-glucose and/or alpha-mannose, is unusually stable, and is not inactivated or inhibited by hydrogen peroxide. Cat-1 was more resistant than other catalases to heat inactivation and to high concentrations of salt and denaturants. Cat-1 exhibited unusual kinetics: at molar concentrations of hydrogen peroxide the apparent V was 10 times higher than at millimolar concentrations. Inactivation of Cat-1 activity with azide and hydroxylamine was according to first order kinetics, while cyanide at micromolar concentrations was a reversible competitive inhibitor.

Synthetic peptide vaccine against Taenia solium pig cysticercosis: successful vaccination in a controlled field trial in rural Mexico

Taenia solium cysticercosis seriously affects human health when localised in the central nervous system (CNS) and causes great economic loss in pig husbandry in rural areas of endemic countries. Increasing the resistance to the parasite in the obligatory host pig may help in curbing transmission. Three synthetic peptides based on protein sequences of the murine parasite Taenia crassiceps, which had previously been shown to induce protection in mice against homologous challenge, were tested as a vaccine against T. solium cysticercosis in pigs. Vaccinated and unvaccinated piglets (240 in all) were distributed in pairs among the peasants' households of two rural villages in Mexico in which 14% of the native pigs were cysticercotic. Ten to twelve months later, the effect of vaccination was evaluated at necropsy. Vaccination decreased the total number of T. solium cysticerci (98.7%) and reduced the prevalence (52.6%). The natural challenge conditions used in this field trial strengthen the likelihood of successful transmission control to both pig and human through a large-scale pig vaccination program. We believe this is a major contribution in anticysticercosis vaccine development as these rather simple yet protective peptides are potentially more cost-effective to produce and less variable in results than antigens that are more complex.

Flowering dynamics in Arum italicum (Araceae): relative role of inflorescence traits, flowering synchrony, and pollination context on fruit initiation

We studied the relative role of inflorescence traits, flowering synchrony, and pollination context for infructescence and fruit initiation in two Spanish populations of Arum italicum, a species in which inflorescences are the pollination unit. In this species, a specialized inflorescence organ, the appendix, is important for pollinator attraction. However, the short floral longevity and the production of mostly one inflorescence per plant make its pollination potentially dependent on strong flowering synchrony and on external factors not controlled by the plant (the pollination context). The flowering period in both sites lasted >3 mo. Day-to-day variation in simultaneous antheses was high, and 11-50% of antheses occurred on days during which no pollen donor was present. Inflorescence traits, flowering synchrony, and between-plant distance all influenced infructescence and fruit initiation, but their relative importance differed between sites. In one large population, infructescence initiation was positively related to inflorescence traits; in a smaller population infructescence initiation increased with the number of donor inflorescences. In both sites, percentage of fruits initiated per infructescence was dependent on a combination of inflorescence traits, flowering synchrony, and between-plant distance. Plants producing 2-4 inflorescences had higher probability of infructescence initiation and overlapped their antheses with more plants than single-inflorescence ones.

[Morphological characterization of annatto fruits 9bixa orellana L.) and its correspondence with protein and isoenzym patterns]

A group of 32 annatto genotypes collected in five Venezuelan regions (Oriente, Centro, Llanos, Andes and Amazonas) and in Brazil were used for morphological studies. The fruit variables with the greatest discriminatory power in the formation of groups were capsule size, spinosity and seed size. On the other hand, an association group among the variables spinosity, spine length, dehiscence and apex shape were formed, also a proportional association between capsule and seed size, and between dehiscent capsule and brown coloured seeds. Additionally, in order to discriminate morphological variables behaviour in respond to electrophoretic variables, a group of protein and isozyme bands associated with fruit characteristics were established. Therefore, a classification system of this species was possible using morphological studies of the capsules, even though a determined association relating morphological and molecular patterns was not found.

[Identification and genetic variability of annatto genotypes (Bixa orellana L.) by means of hydrosoluble proteins and isoenzymes]

In order to identify and to determine the genetic variability of 36 annatto genotypes (Bixa orellana L.) collected in five Venezuelan regions (Oriente, Centro, Llanos, Andes and Amazonas) and in Brazil, hydrosoluble protein patterns as well as specific isozyme patterns (alpha-esterase, beta-esterase and peroxidase) were studied using extracts of germinated annatto seeds with radicles of 10 to 15 mm long. Each electrophoretic system allowed genotype discrimination by means of unique banding patterns: both the hydrosoluble protein and the electrophoretic system of beta-esterase with nine banding patterns each; whilst alpha-esterase and peroxidase discriminated eight and three genotypes, respectively. On the other hand, a combination of all the systems permitted a greater discrimination since 34 out of 36 genotypes could be distinguished. Eight mayor groups were formed that showed high levels of genetic diversity (40 to 60%) with no association between geographic and genetic distances, probably because of human influence in the aleatory distribution of this crop. Results obtained indicated that using electrophoretic banding patterns, a classification system could be established for identification and genetic variability purposes in this species.

Mutation and haplotype analyses in 26 Spanish Sanfilippo syndrome type A patients: possible single origin for 1091delC mutation

Mucopolysaccharidosis IIIA, also known as Sanfilippo syndrome type A, is an autosomal recessive storage disorder caused by deficiency of sulfamidase. The disease results in severe central nervous system degeneration often with mild somatic features that may delay the clinical diagnosis. Molecular analyses would allow early and unequivocal heterozygote detection, providing a useful tool for genetic counselling. About 40 mutations have been reported in the sulfamidase gene, with a very uneven distribution in different patient populations. We have previously described the high prevalence of mutation 1091delC in a small number of Spanish Sanfilippo A patients. The aim of the present work is to extend the mutational study to a total of 26 unrelated patients and perform haplotype analysis in order to study the origin of some mutations. The whole coding region of the gene was scanned by SSCP analysis and sequencing. This allowed the identification of 14 different mutations, corresponding to 90% of the mutant alleles. Seven of these mutations were only found in this Spanish group of patients, three of which, R150W, R433Q and R433W, are described here for the first time. We have also analyzed four internal polymorphisms and constructed the corresponding haplotypes. Chromosomes bearing mutation 1091delC show a conserved haplotype suggesting a common origin for this mutation. Moreover, all other mutations found twice or more also have conserved haplotypes for those polymorphic markers.

Hepatic dysfunction after cardiac surgery in children

OBJECTIVE: The objective of this study was to analyze the incidence and significance of hepatic dysfunction after cardiac surgery in children. DESIGN: Prospective, observational study. SETTING: Pediatric intensive care unit of a university hospital. PATIENTS: The study consisted of 232 children ranging in age from newborn to 17 years with no history of liver disease. MEASUREMENTS AND MAIN RESULTS: Aspartate aminotransferase (AST), alanine aminotransferase (ALT), gammaglutamyltranspeptidase (GGT), alkaline phosphatase, total and conjugated bilirubin, blood glucose, urea, creatinine, and coagulation studies were determined at admission, at 24 and 48 hrs, and at 7 days. Hepatic dysfunction was taken as an ALT of > 100 IU/L or a moderate or high hepatic score. The statistical study included bivariate analysis and multivariate logistic regression to study the risk factors for hepatic dysfunction. Twenty-one patients (9%) showed an ALT > 100 IU/L, and 29.3% had a moderate or high hepatic score. A relationship was found between hepatic dysfunction and the type of cardiopathy (D-transposition of the great arteries and coarctation of the aorta), shock, the administration of dopamine or epinephrine, renal insufficiency, the presence of pulmonary changes (pulmonary edema, atelectasis, pulmonary hypertension, hypoxemia), hematologic disturbances (prothrombin time, kaolin-cephalin time, fibrinogen, and platelets), and the need for a greater number of transfusions of packed cells, plasma, and platelets. Compared with 7.6% of the rest of the patients (p <.001), 38% of patients with an ALT > 100 IU/L died. The hepatic score of those patients who died was 4.2 (2.3)-higher than that of the survivors at 1.5 (1.8), (p <.001). Shock and renal insufficiency were the factors most significantly related to the development of hepatic dysfunction. CONCLUSIONS: Hepatic dysfunction is an uncommon complication in children after cardiac surgery. This complication is related mainly to hemodynamic disturbances and renal insufficiency and is an indicator of poor prognosis.

Collection, processing and cryopreservation of umbilical cord blood for unrelated transplantation

Umbilical cord blood (UCB) transplantation is being used as an alternative source of hematopoietic stem cells for bone marrow reconstitution. Separation and processing of UCB samples in large numbers for storage in cord blood banks ideally needs to be partially automated. The aim of this study was to establish and standardize a method for unrelated cord blood banking as well as the biological characterization of the samples. Up to October 1999, a total of 938 UCB units (mean volume 84.6 +/- 23.6 ml, nucleated cell (NC) count 0.90 +/- 0.37 x 109, total CFU-GM 79 +/- 72 x 104, CD34+ cell count 2.46 +/- 2.72 x 106) had been collected. Twenty-three per cent of all UCB samples had a NC count below 0.4 x 109 and were discarded. The initial bacterial contamination rate was reduced to less than 5% as a result of extensive training in collection procedures. Using a modification of a triple bag system and adding a solution of 6% hydroxyethyl starch, the UCB was separated by two centrifugation steps into three components: buffy coat, red cell and plasma fractions. The overall recoveries for NC, CFU-GM and CD34+ cells were 87.4 +/- 8.5%, 88.8 +/- 6.6% and 90.3 +/- 12.4%, respectively, in a mean final volume of 27 +/- 4.2 ml.

Relationship of plasma bone cytokines with hypercalcemia in cancer patients

The pathogenesis of cancer-associated hypercalcemia is not yet completely understood. This syndrome appears to be a consequence of the tumor production of humoral factors, mainly parathyroid hormone related protein (PTHrP). However, patients with humoral hypercalcemia of malignancy have features suggesting that factors other than PTHrP might play a role in this syndrome. We performed a case-control study in cancer patients with and without hypercalcemia. A total of 105 patients with a variety of tumors, 60 of them with hypercalcemia (corrected serum calcium over 2.6 mmol/l), and 45 without hypercalcemia. In a previous study, we demonstrated that plasma PTHrP was highly associated with hypercalcemia in these patients. In the present study, we measured the plasma levels of various bone cytokines: interleukin-1beta (IL-1beta), interleukin-6 (IL-6), transforming growth factor (TGF) alpha, and tumor necrosis factor (TNF) alpha, in these cancer patients. We also determined C-terminal type I procollagen (PICP) and C-terminal telopeptide of type I collagen (ICTP), bone formation and bone resorption markers, respectively, in serum in these patients. We found that these osteolytic cytokines do not increase in plasma by the presence of hypercalcemia. In fact, using a logistic regression analysis, a significant (P<0.02) association was found between the low plasma levels of IL-1beta and TGFalpha and hypercalcemia, independent of plasma PTHrP and the presence of bone metastasis, in these patients. No significant association between the plasma levels of IL-6 or TNFalpha and hypercalcemia was found in these cancer patients. Serum ICTP correlated (r=0.35; P=0.008) with hypercalcemia in these patients, but none of the cytokines studied in plasma correlated with either ICTP or PICP in these hypercalcemic patients. Our data indicate that the circulating levels of several bone cytokines are not enhanced by PTHrP in hypercalcemic cancer patients. The mechanism responsible for the association between the low plasma levels of some of these cytokines and hypercalcemia in these patients remains obscure. However, this finding does not rule out the possible local bone effects of these cytokines, contributing to hypercalcemia in cancer patients.

Snakebites and ethnobotany in the northwest region of Colombia. Part III: neutralization of the haemorrhagic effect of Bothrops atrox venom

Thirty-one of 75 extracts of plants used by traditional healers for snakebites, had moderate or high neutralizing ability against the haemorrhagic effect of Bothrops atrox venom from Antioquia and Chocó, north-western Colombia. After preincubation of several doses of every extract (7.8-4000 microg/mouse) with six minimum haemorrhagic doses (10 microg) of venom, 12 of them demonstrated 100% neutralizing capacity when the mixture was i.d. injected into mice (18-20 g). These were the stem barks of Brownea rosademonte (Caesalpiniaceae) and Tabebuia rosea (Bignoniaceae); the whole plants of Pleopeltis percussa (Polypodiaceae), Trichomanes elegans (Hymenophyllaceae) and Senna dariensis (Caesalpiniaceae); rhizomes of Heliconia curtispatha (Heliconiaceae); leaves and branches of Bixa orellana (Bixaceae), Philodendron tripartitum (Araceae), Struthanthus orbicularis (Loranthaceae) and Gonzalagunia panamensis (Rubiaceae); the ripe fruits of Citrus limon (Rutaceae); leaves, branches and stem of Ficus nymphaeifolia (Moraceae). Extracts of another 19 species showed moderate neutralization (21-72%) at doses up to 4 mg/mouse, e.g. the whole plants of Aristolochia grandiflora (Aristolochiaceae), Columnea kalbreyeriana (Gesneriaceae), Sida acuta (Malvaceae), Selaginella articulata (Selaginellaceae) and Pseudoelephantopus spicatus (Asteraceae); rhizomes of Renealmia alpinia (Zingiberaceae); the stem of Strychnos xinguensis (Loganiaceae); leaves, branches and stems of Hyptis capitata (Lamiaceae), Ipomoea cairica (Convolvulaceae), Neurolaena lobata (Asteraceae), Ocimum micranthum (Lamiaceae), Piper pulchrum (Piperaceae), Siparuna thecaphora (Monimiaceae), Castilla elastica (Moraceae) and Allamanda cathartica (Apocynaceae); the macerated ripe fruits of Capsicum frutescens (Solanaceae); the unripe fruits of Crescentia cujete (Bignoniaceae); leaves and branches of Piper arboreum (Piperaceae) and Passiflora quadrangularis (Passifloraceae). When the extracts were independently administered by oral, i.p. or i.v. route either before or after an i.d. venom injection (10 microg), neutralization of haemorrhage dropped below 25% for all the extracts. Additionally, B. rosademonte and P. percussa extracts were able to inhibit the proteolytic activity of B. atrox venom on casein.

A new gene-pseudogene fusion allele due to a recombination in intron 2 of the glucocerebrosidase gene causes Gaucher disease

Gaucher disease is the most prevalent sphingolipid storage disorder in humans caused by a recessively inherited deficiency of the enzyme glucocerebrosidase. More than 100 mutations have been described in the glucocerebrosidase gene causing Gaucher disease. Some of them are complex alleles with several mutations due to recombination events between the gene and its highly homologous pseudogene. The generation of these recombinant alleles involves, in most cases, a crossover in the 3' end of the gene, beyond exon 8. However, in a few cases recombination took place in a more upstream location. Here we describe the analysis of a patient with type I Gaucher disease who bears a new complex allele. This allele was originated by a crossover between the gene and the pseudogene at intron 2, the most upstream recombination site described so far, which gave rise to a fusion gene. The patient was first diagnosed as homozygous for the c.1226 A --> G (N370S) mutation but the early onset of the disease prompted us to perform parental DNA analysis which showed that the mother was not a N370S carrier, suggesting deletion of at least part of the gene. Molecular analysis of the complex allele was carried out by Southern blot, PCR, and sequencing. We were able to close down the region of the recombination event to an interval of 18 nucleotides, corresponding to the last 15 nucleotides of intron 2 and the first 3 nucleotides of exon 3 of the gene. These 18 nucleotides are identical between the gene and pseudogene making any further refinement impossible. An exhaustive list of published glucocerebrosidase complex alleles, describing their recombination points, is included for comparison.

Parotid metastasis from renal clear cell adenocarcinoma. An unusual site for metastasis

Metastasis to the parotid region is rare, and originates primarily from head and neck squamous cell carcinoma and melanoma of the skin. Renal clear cell adenocarcinoma has considerable metastatic potential and the parotid gland is one possible destination. Histopathologic study is important to differentiate this entity from primary clear cell parotid neoplasm.

Snakebites and ethnobotany in the northwest region of Colombia: Part II: neutralization of lethal and enzymatic effects of Bothrops atrox venom

Twelve of 74 ethanolic extracts of plants used by traditional healers for snakebites in the northwest region of Colombia, were active against lethal effect of Bothrops atrox venom when they were i.p. injected into mice (18-20 g). After preincubation of sublethal doses of every extract (0.5-4.0 mg/mouse) with 1.5 i.p. lethal dose 50% (LD50) (99.3 microg) of venom, seven of them demonstrated 100% neutralizing capacity within 48 h. These were the stem barks of Brownea rosademonte (Caesalpiniaceae) and Tabebuia rosea (Bignoniaceae); rhizomes of Renealmia alpinia (Zingiberaceae) and Heliconia curtispatha (Heliconiaceae); the whole plants of Pleopeltis percussa (Polypodiaceae) and Trichomanes elegans (Hymenophyllaceae); and the ripe fruits of Citrus limon (Rutaceae). The other five extracts showing partial neutralization (45-80%; 10-30% survival rate in the control group receiving the venom alone; P<0.05) were: leaves, branches and stem of Costus lasius (Costaceae); the whole plant of Sida acuta (Malvaceae); rhizomes of Dracontium croatii (Araceae); leaves and branches of Bixa orellana (Bixaceae) and Struthanthus orbicularis (Loranthaceae). When the extracts were independently administered per oral or i.p. route 60 min before an i.m. venom injection (204 microg=1.5 i.m. LD50), C. limon, T. elegans, B. orellana and T. rosea extracts had partial and significant neutralizing capacity against B. atrox venom lethal effect. C. limon extract was also partially effective when it was administered either i.v. 15 min before or i.p. 5 min after an i.m. venom injection. Three of the 12 extracts with anti-lethal effect (C. limon, D. croatii and S. acuta) were devoid of antiphospholipase A2 activity, when they were tested against one minimum indirect hemolytic dose of B. atrox venom (2 microg) in agarose-erythrocyte-egg yolk gels.

Expression of the proteinase specialized in bone resorption, cathepsin K, in granulomatous inflammation

BACKGROUND

The cysteine proteinase cathepsin K has aroused intense interest as the main effector in the digestion of extracellular matrix during bone resorption by osteoclasts. The enzyme is not a housekeeping lysosomal hydrolase, but is instead expressed with striking specificity in osteoclasts. In this work, we present evidence for the association of cathepsin K with the granulomatous reaction. Granulomas are inflammatory tissue reactions against persistent pathogens or foreign bodies. We came across cathepsin K while working on Echinococcus granulosus, a persistent tissue-dwelling, cyst-forming parasite that elicits a granulomatous response.

MATERIALS AND METHODS

The walls of hydatid cysts from infected cattle were solubilized. Strong proteolytic activity was detected in the extracts. The proteinase responsible was purified by anion exchange and gel filtration. The purified protein was subjected to N-terminal sequencing, and its identity further confirmed by Western blotting, with a cathepsin K-specific antibody. The same antibody was used to localize the proteinase in paraffin-embedded sections of the parasite and the local host response.

RESULTS

A proteinase was purified to near homogeneity from hydatid cyst extracts. The enzyme was unequivocally identified as host cathepsin K. Both the proenzyme and the mature enzyme forms were found. Cathepsin K was then immunolocalized both to the parasite cyst wall and to the epithelioid and giant multinucleated cells of the host granulomatous response.

CONCLUSIONS

In the granulomatous response to the hydatid cyst, cathepsin K is expressed by epithelioid and giant multinucleated cells. We propose that, by analogy with bone resorption, cathepsin K is secreted by the host in an attempt to digest the persistent foreign body. Both processes, bone resorption and granulomatous reactions, therefore tackle persistent extracellular material (the bone matrix or the foreign body), and utilize specialized cells of the monocytic lineage (osteoclasts or epithelioid/giant cells) secreting cathepsin K as an effector.

Autoradiographic mapping of mu-opioid receptors during opiate tolerance and supersensitivity in the rat central nervous system

In this autoradiographic study we have analysed the regional changes in the density of mu-opioid receptors produced by the chronic administration of sufentanil alone and after concurrent administration with nimodipine. mu-Opioid receptors in the central nervous system (CNS) of rats were labelled using 5 nM [3H]DAMGO. Sufentanil, a high-efficacy agonist, was administered for 7 days by chronic infusion (2 microg/h). Another group of animals received a simultaneous infusion of sufentanil (2 microg/h) and nimodipine (1 microg/h) for 7 days. These two drug regimes have been previously shown to induce tolerance and supersensitivity to the analgesic effect of the opioid, respectively. Our results clearly demonstrate that opioid tolerance is associated with a generalised down-regulation of mu-opioid binding sites throughout the brain and the spinal cord. Compared with the findings in tolerant animals, the CNS of animals supersensitive to sufentanil showed less down-regulation of mu-opioid receptors, to the extent that, particularly in brain areas related to nociception, such as the somatosensory cortex, central grey, raphe magnus nucleus and dorsal horn of the spinal cord, no down-regulation occurred. These neurochemical findings may contribute to the functional interaction between nimodipine and sufentanil that we have previously observed in analgesic studies.

Snakebites and ethnobotany in the northwest region of Colombia: Part I: traditional use of plants

In Antioquia and Chocó, traditional healers attend 60% of snakebites. With the aim to produce an inventory of the plants used by the healers to treat snakebites and to document the methods of preparation, administration, the dosage, number of patients treated throughout their years of practice with treatment results, 20 healers with experience in Bothrops, Porthidium and Bothriechis envenomations were interviewed between August, 1996 and November, 1998. They belong to nine black and three indigenous rural communities located near the towns of Bojayá, Vigía del Fuerte, Unguía (Atrato river valley), Nuquí and Bahía Solano (Pacific coast). Based on field interviews, 101 species of plants were identified as used to treat snakebites. The part used of each plant varies according to the species. Sixty plants are used in the form of drinks prepared by infusion, decoction or maceration; 78 as external baths on the affected extremity; 11 for steam application and 39 for poultices; the latter is used mainly when the bite is complicated by local necrosis. In mild and moderate envenomations, they generally use a mixture of three plants, while in severe cases they mix from five to 12, a handful of each one. Treatment is generally performed for 1-3 days, when the patient reacts positively. They reported to have treated 454 patients during their years of experience, 20 of them (4.4%) died. With the guidance of the healers, 77 species of plants were collected and photographed. These plants belong to 41 families, of which Piperaceae (13 species), Araceae (six species), Asteraceae (five species) and Gesneriaceae (three species) have the highest number of species.

Vaccination against Taenia solium cysticercosis in underfed rustic pigs of México: roles of age, genetic background and antibody response

Vaccination of pigs of mixed genetic make-up, raised as rustically as done in rural Mexico, resulted in effective protection to experimental challenge against Taenia solium cysticercosis. Maximum protection was achieved if pigs were immunized at 70 days of age. There was large variation of viable parasite load within vaccinated pigs and controls, which is suggestive of significant genetic factors influencing susceptibility, besides immunization. Our results strengthen the advisability of pig vaccination for control of T. solium cysticercosis, since it lowers the number of viable cysticerci capable of transforming into tapeworms.

Biology, ecology, and management of the bulb mites of the genus Rhizoglyphus (Acari: Acaridae)

Bulb mites of the genus Rhizoglyphus (Claparède) (Acari: Acaridae) have been identified as pests of many crops and ornamentals in storage, in the greenhouse, and in the field. The most important hosts are species in the family Liliaceae (e.g. Allium spp.), but bulb mites will often attack other important crops such as potatoes (Solanum sp.) and carrots (Daucus carota). Despite their economic importance and broad distribution, the systematics of the genus remains in a state of confusion and is in need of a comprehensive revision. In addition, the field biology and ecology of these mites is not well understood, and methods for sampling, monitoring, and loss assessment are limited. Management of bulb mites is complicated by their short generation time, high reproductive potential, broad food niche, interactions with other pests and pathogens, and unique adaptations for dispersal. Historically, control of these acarine pests has relied on the use of synthetic miticides and insecticides, but this option is now limited due to documented resistance and withdrawal of registration of some products. Alternative control strategies, including cultural and biological control, have shown limited success, but need to be further developed and implemented.

Parathyroid hormone-related protein, parathyroid hormone, and vitamin D in hypercalcemia of malignancy

The pathogenesis of cancer-associated hypercalcemia is not yet completely understood. In the majority of cancer patients, hypercalcemia appears to be a consequence of the tumor production of parathyroid hormone (PTH)-related protein (PTHrP). However, patients with humoral hypercalcemia of malignancy, in contrast to those with primary hyperparathyroidism, have an uncoupled bone turnover, and they usually have low circulating levels of 1.25(OH)2D3. We performed a case-control study to assess the relationship of plasma PTHrP, PTH and 1.25(OH)2D3 with hypercalcemia in cancer patients with a variety of tumors. Sixty of these patients had hypercalcemia, and 45 were normocalcemic. We measured PTHrP and PTH by immunoradiometric assay (Nichols), and 1.25(OH)2D3 by radioreceptor assay (Nichols), in plasma in both groups of cancer patients. Using a logistic regression analysis, we found that the higher PTHrP in plasma, the higher association with hypercalcemia occurred in these patients. In addition, the decreased plasma levels of PTH and 1.25(OH)2D3 in the majority of cancer patients were found to be significantly associated with hypercalcemia. Our results indicate that the combined determination of PTH, PTHrP and 1.25(OH)2D3 in plasma represents a more comprehensive approach to the investigation of hypercalcemia in cancer patients. Our data also support the role of PTHrP as a humoral factor responsible for hypercalcemia in these patients.

[Detection of antibodies to beta-amyloid in carriers of E280A mutation in the presenilin-1 gene]

OBJECTIVE

To investigate some immune component that could contribute to the pathogenesis of Alzheimer's disease associated with the E280A mutation of the presenilin-1 gene (PS-1).

PATIENTS AND METHODS

Serum antibodies against both cardiolipin and beta-amyloid peptides (beta 1-40 and beta 1-42) were quantitated by means of an indirect ELISA technique in carriers of the mutation, either healthy or with Alzheimer's disease, as well as in normal controls without the mutation.

RESULTS

Out of 19 patients with Alzheimer's disease only 2 had increased values of antibodies to cardiolipin, namely: one with 14.58 micrograms/ml of IgM and the other with 36.16 micrograms/ml of IgG. The remaining individuals revealed values under 10 micrograms/ml, considered normal, and there was no significant difference between the groups. Significant serum reactivity (p < 0.001) was detected against both beta-amyloid peptides in the mutation carriers, either with or without Alzheimer's disease, as compared to the control group. No correlation was detected between this antibody response and the mental or functional situation of the patients.

CONCLUSION

beta-amyloid antibodies, present in the mutation carriers, may simply represent a marker of immune activation induced by beta-amyloid with no in vivo effect; however, despite the results, the possibility can not be ruled out of a pathogenic role of these antibodies in early onset Alzheimer's disease.

Differential effects of respiratory syncytial virus and adenovirus on mononuclear cell cytokine responses

Respiratory syncytial virus (RSV) and adenovirus (Advs) serotype 3 (Adv3) and 7h (Adv7h) are associated with mild to severe respiratory infection and are indistinguishable during the acute phases of the illnesses. However, outcome and long-term prognosis are different with both infections. RSV infection is associated with later development of asthma, and Adv, mainly Adv7h, with severe lung damage, bronchiectasis, and hyperlucent lung. We hypothesized that this difference could be partly due to different immune responses induced by these viruses. To test this hypothesis we quantified TCD4+, TCD8+, and BCD19+ expressing the interleukin-2 receptor-alpha chain (CD25) and interferon-gamma (IFN-gamma), interleukin (IL)-10, and IL-4 in the supernatant of peripheral blood mononuclear cells (PBMC) from school children infected in vitro with and without RSV, Adv7h, and Adv3 and after phytohemagglutinin (PHA) stimulation in the presence or absence of these viruses at a multiplicity of infection (MOI) of 1. PBMC from every child produced more IL-10 (p </= 0.05) when infected with RSV than with Advs and noninfected control, and Adv induced more (p </= 0.05) IFN-gamma than did RSV and control. The IL-10/IFN-gamma ratio was significantly higher (p </= 0.05) in RSV-infected and significantly lower (p </= 0.05) in Adv-infected PBMC, than in noninfected cells. PHA-stimulated BCD19+ RSV- infected cells expressed more (p </= 0.05) IL-2R than did Adv-infected cells. These results suggest that Advs induce a Th-1-type immune response that is not seen with RSV. These patterns persist despite intersubject variation in the absolute quantity of cytokine produced.

Concordance between hip ultrasonography and hip arthrography in the assessment of developmental dysplasia of the hip

Controversy exists regarding the possibility of predicting hip reducibility in the congenitally dislocated hip, with arthrography still regarded as the gold standard in this situation. This study aims at assessing the degree of concordance between ultrasonography and arthrography in the detection of anatomic elements obstructing hip reduction. Forty-nine hips were studied both by ultrasonography and arthrography. Three anatomic sources of obstruction to reduction were assessed in each hip: ligamentum teres hypertrophy, inverted labrum, and the presence of soft tissue in the acetabulum. For each variable, congruence between ultrasound and arthrography was measured by kappa analysis. Values > 0.40 expressed sufficient concordance, and they were detected with regard to inverted labrum and the presence of soft tissue in the acetabulum. The results of this study suggest that ultrasonography may be considered a reliable technique for the prediction of the main causes of obstruction in the congenitally dislocated hip, such as inverted labrum and soft tissue in the acetabulum.

Attempted suicide: repetition and survival--findings of a follow-up study

OBJECTIVE

This was a prospective follow-up study of suicidal patients to assess the influence over time of different risk factors, whether on completed suicides or reattempts. Survival analysis makes it possible to weigh the influence of variables that increase or decrease a patient's life span or that make reattempts less likely.

METHOD

A cohort of 150 patients admitted to a psychiatric department after a suicide attempt was followed up over 10 years. The study protocol used standardized criteria, and periodic controls were carried out in all patients.

RESULTS

In total, 12% of patients completed suicide, 10% died from natural causes, 75% were still alive and 25% reattempted. In the survival analysis the risk for completed suicide or reattempting was highest during the first 2 years after the index attempt admission. Global Assessment of Functioning (GAF) was the factor that most increased survival time. The number of previous attempts decreased survival time and increased the risk of reattempts.

CONCLUSION

Since suicidal risk varied over time, intensifying contact with patients during periods of psychopathological change or life events could prolong their survival.

A randomized blinded clinical trial of two antivenoms, prepared by caprylic acid or ammonium sulphate fractionation of IgG, in Bothrops and Porthidium snake bites in Colombia: correlation between safety and biochemical characteristics of antivenoms

A randomized blinded clinical trial was performed in 53 patients bitten by Bothrops sp. and Porthidium sp. in Antioquia and Chocó, Colombia, in order to compare the efficacy and safety of two antivenoms made of whole IgG obtained by either ammonium sulphate (monovalent anti-B. atrox) or caprylic acid (polyvalent) fractionation. Additionally, antivenoms were compared by electrophoretic and chromatographic analyses and anticomplementary activity in vitro. With a protocol of 2, 4 and 6 antivenom vials for the treatment of mild, moderate and severe envenomings, respectively, both antivenoms were equally efficient to neutralize the most relevant signs of envenoming and to clear serum venom levels in patients from the first hour and later on. Three patients with severe envenoming and initially treated with less than six vials on admission had persistent or recurrent venom antigenemia within 12-48 h. Monovalent antivenom fractionated by ammonium sulphate precipitation had higher amounts of protein aggregates and nonimmunoglobulin proteins than polyvalent antivenom fractionated by caprylic acid precipitation. Both antivenoms presented anticomplementary activity in vitro, being higher in the monovalent product. In agreement, monovalent antivenom induced a significantly higher incidence of early antivenom reactions (52%) than polyvalent antivenom (25%).

[Adrenal oncocytoma]

OBJECTIVE

To describe an additional case of adrenocortical oncocytoma that had been incidentally discovered.

METHODS/RESULTS

A case of adrenocortical oncocytoma in a 30-year-old male is presented. Patient evaluation by US, CT and arteriography revealed a well-defined mass between the upper pole of the left kidney, spleen and stomach, that appeared to be of adrenal origin. Histopathological and ultrastructural studies revealed a benign adrenocortical oncocytoma with moderate cell atypia but with no signs of infiltration.

CONCLUSION

Adrenocortical oncocytoma must be included in the differential diagnosis of solid adrenal tumors.

Control of host complement activation by the Echinococcus granulosus hydatid cyst

Cystic hydatid disease is caused by the multicellular parasite Echinococcus granulosus. The hydatid cyst, being a long-lived, large, antigenic structure lodged in the host's internal organs, could potentially elicit major inflammatory responses. However, in practice, the cyst causes only minimal local inflammation. The complement system is a major pathway to immune-mediated inflammation. Recent results have shown that the host-exposed structure of the cyst, the hydatid cyst wall (HCW), fails to trigger the complement system strongly. We have carried out a wide survey for the mechanisms making the cyst wall relatively complement-inert. The results of those studies are summarised in this work, with emphasis on the most recently identified of the complement inhibitory mechanisms. This is based on a non-protein heat-stable, parasite inhibitor of the activation of host complement factor B.

Adaptive strategies of edaphic arthropods

For those arthropod species adapted for living below the soil surface, the soil is a refuge from the biotic and abiotic perturbations existing above ground. Convergent morphological, physiological, and behavioral adaptations of epedaphic, euedaphic, and hemiedaphic arthropods to selective aspects of subterranean existence are examined in light of overlapping ecological niches. The abiotic impact of the soil environment and its relationship to arthropod evolution, radiation, and ecology are discussed as well. Specific areas addressed include the invasion of land by marine arthropods, the impact of morphology on arthropod mobility, osmoregulatory/respiratory systems, and defensive strategies.

Differential effects of biotin deficiency and replenishment on rat liver pyruvate and propionyl-CoA carboxylases and on their mRNAs

Although the role of vitamins as prosthetic groups of enzymes is well known, their participation in the regulation of their genetic expression has been much less explored. We studied the effect of biotin on the genetic expression of rat liver mitochondrial carboxylases: pyruvate carboxylase (PC), propionyl-CoA carboxylase (PCC), and 3-methylcrotonyl-CoA carboxylase (MCC). Rats were made biotin-deficient and were sacrificed after 8 to 10 weeks, when deficiency manifestations began to appear. At this time, hepatic PCC activity was 20% of the control values or lower, and there was an abnormally high urinary excretion of 3-hydroxyisovaleric acid, a marker of biotin deficiency. Biotin was added to deficient primary cultured hepatocytes. It took at least 24 h after the addition of biotin for PCC to achieve control activity and biotinylation levels, whereas PC became active and fully biotinylated in the first hour. The enzyme's mass was assessed in liver homogenates from biotin-deficient rats and incubated with biotin to convert the apocarboxylases into holocarboylases, which were detected by streptavidin blots. The amount of PC was minimally affected by biotin deficiency, whereas that of the alpha subunits of PCC and of MCC decreased substantially in deficient livers, which likely explains the reactivation and rebiotinylation results. The expression of PC and alphaPCC was studied at the mRNA level by Northern blots and RT/PCR; no significant changes were observed in the deficient livers. These results suggest that biotin regulates the expression of the catabolic carboxylases (PCC and MCC), that this regulation occurs after the posttranscriptional level, and that pyruvate carboxylase, a key enzyme for gluconeogenesis, Krebs cycle anaplerosis, and fatty acid synthesis, is spared of this control.

[Identification, by Western blot, of Fasciola hepatica immunogens recognized by the sera of experimentally infected rats]

This paper was aimed at identifying the main components present in the excretory-secretory antigens of adult parasite which are recognized by the sera of rats experimentally infected with metacercariae of Fasciola hepatica, by using the Western Blot technique. The cynetics of antibodies was also determined with and indirect ELISA. The results obtained allowed to find 31 components with approximate molecular weights from 11 to 136 kD. The predominant fractions were the following: 11-13 kD, 14-16 kD, 23-33 kD, 55-57 kD, 65-71 kD, and 86-136 kD. Antibodies were detected from the 2nd. week of infection in 80% of the animals and from the 3rd. week in 100% of them. There were no antibodies during the first week. The identification of these antibodies may contribute to a better understanding of the mechanisms of immunity linked with the infection by F. hepatica.

Dynamics of antigenemia and coproantigens during a human Fasciola hepatica outbreak

In the present study the dynamics of antigenemia and coproantigens were studied in patients with Fasciola hepatica infection during an outbreak occurring in La Palma, Pinar del Río, in the West Province of Cuba. Stool and serum samples were collected from 67 patients and 40 healthy subjects. Stool samples were studied by a simple gravity sedimentation technique and an ES78 sandwich enzyme-linked immunosorbent assay (ELISA) for observation of eggs and detection of parasite coproantigens, respectively. Serum samples were also studied by the ES78 sandwich ELISA and an indirect ELISA to detect circulating antigens and antibodies, respectively. At the beginning of the study, 8 of 67 patients had patent infections and 59 had prepatent infections, which was determined by the recent consumption of lettuce contaminated with metacercariae of F. hepatica, the presence of clinical symptoms, and the absence of Fasciola eggs in their stools. Patients with prepatent infections were monitored by all techniques until patency. Circulating antigens were not detected in patients with patent infections. However, coproantigens were clearly detected in all patients with patent infections. On the other hand, 28.8% of patients with prepatent infections tested positive for circulating antigens and 81.4% tested positive for coproantigens in the first stool sample studied. Only two other coproantigen determinations were necessary to diagnose 93.2% of the patients. While circulating antigen levels diminished in all patients during the infection, coproantigen levels increased. The present study demonstrates that the ES78 sandwich ELISA is a better tool than parasitological examination for diagnosis of active early infection, since by the combination of the circulating-antigen detection assay and the coproantigen detection assay 91% of patients were able to be diagnosed at the beginning of the study. In contrast, a coprologic analysis repeated over several weeks was necessary to diagnose 100% of the patients.

Cocaine use among heroin users in Spain: the diffusion of crack and cocaine smoking. Spanish Group for the Study on the Route of Administration of Drugs

STUDY OBJECTIVE

To describe the prevalence and patterns of use of crack and cocaine hydrochloride among heroin users in Spain. To explore if the expansion of heroin smoking is accompanied by a similar phenomenon for cocaine.

DESIGN

Cross sectional study in 1995. Face to face interviews using a structured questionnaire.

SETTING

Three cities with different prevalences of heroin use by smoking: high (Seville), intermediate (Madrid), and low (Barcelona).

PARTICIPANTS

909 heroin users, 452 in treatment and 457 out of treatment.

MAIN RESULTS

Last month prevalence of crack use was 62.3% in Seville, 19.4% in Madrid, and 7.7% in Barcelona. Most users in Madrid (86.5%) and Barcelona (100%) generally prepared their own crack, usually with ammonia as alkali; in Seville most users (69.7%) bought preprocessed crack. The proportion of users who began taking cocaine (crack or cocaine hydrochloride) by smoking has increased progressively since the seventies, rising to 74.1% in Seville, 61.5% in Madrid, and 28% in Barcelona in 1992-1995, with the earliest increase in Seville. The factors associated with crack use were: residence in Seville (odds ratio (OR) = 16.3), cocaine hydrochloride use mainly by smoking (OR = 5.0), by sniffing (OR = 2.7) or by injecting (OR = 2.5), heroin use mainly by smoking (OR = 2.8) and weekly use of cannabis (OR = 1.9).

CONCLUSIONS

In Spain smoking cocaine may be progressively diffusing from the south west to the north east, similar to what has happened with smoking heroin, but beginning later in time. The factors associated with smoking cocaine are basically ecological or cultural in nature (characteristics of the available drugs and the main route of heroin administration in each city).