Characterization of the lipA gene encoding the major lipase from Pseudomonas aeruginosa strain IGB83

The lipases produced by Pseudomonas have a wide range of potential biotechnological applications. Pseudomonas aeruginosa IGB83 was isolated as a highly lipolytic strain which produced a thermotolerant and alkaline lipase. In the present work, we have characterized the P. aeruginosa IGB83 gene (lipA) encoding this enzyme. We describe the construction of a lipA mutant and report on the effect of two carbon sources on lipase expression.

Bacterial DNA in synovial fluid cells of patients with juvenile onset spondyloarthropathies

OBJECTIVE

To identify bacterial DNA in synovial fluid cells of patients with active juvenile onset spondyloarthropathy (SpA).

METHODS

The main group of study constituted 22 patients with juvenile onset SpA. In addition, five patients with adult onset SpA and nine with rheumatoid arthritis (RA) were studied. Polymerase chain reaction (PCR) with either genus- or species-specific primers was performed on synovial fluid cells to detect DNA sequences of Chlamydia trachomatis, Yersinia enterocolitica, Salmonella sp., Shigella sp., Campylobacter sp. and Mycobacterium tuberculosis. The presence of antibacterial antibodies in sera and synovial fluid was also determined by enzyme-linked immunoassay.

RESULTS

The synovial fluid of nine patients with juvenile onset SpA, three with adult onset SpA and one with RA contained bacterial DNA. Five juvenile onset SpA samples had DNA of one single bacterium; two juvenile onset SpA and three adult onset SpA had DNA of two bacteria and two juvenile onset SpA had DNA of three bacteria. Overall, Salmonella sp. DNA was detected in seven synovial fluid samples, Shigella sp., Campylobacter sp. and M. tuberculosis were found in four samples each, and C. trachomatis was found in two. The bacterial DNA findings correlated with neither diagnosis nor disease duration. One RA synovial fluid had DNA of Campylobacter sp. Neither serum nor synovial fluid antibacterial antibodies correlated with DNA findings or clinical diagnosis.

CONCLUSION

In this study, single and several combinations of bacterial DNA were identified in the synovial fluid of patients with long-term undifferentiated and definite juvenile onset SpA and adult onset SpA. Of relevance is that bacterial DNA corresponds to bacteria producing endemic disease in our population.

Quantification in mass units of group 1 grass allergens by a monoclonal antibody-based sandwich ELISA

BACKGROUND

Grass pollen extracts currently used for allergy diagnosis and immunotherapy are a complex mixture of proteins of which only a few have allergenic activity. Lol p 1 is one of the most important allergens in grass pollen extracts.

OBJECTIVES

To develop a two-site enzyme-linked immunosorbent assay for the quantification of Lol p 1 and other group 1 allergens from grass species, and to assess its suitability for quantifying this group of allergens.

METHODS

Balb/c mice immunized with recombinant Lol p 1 were used for the production of monoclonal antibodies. Screening of hybridomas was performed by direct ELISA, and selected monoclonal antibodies were immobilized on ELISA plates and incubated with samples containing group 1 allergens. Bound allergens were detected by a combination of biotinylated Lol p 1-specific monoclonal antibody and peroxidase-streptavidin conjugate.

RESULTS

The assay is based on three Lol p 1-specific monoclonal antibodies with different epitope specificities. The optimized ELISA measured Lol p 1 concentrations ranging from 125 to 1000 ng/mL and could quantify group 1 allergen from grass species belonging to the Pooidea subfamily. The assay does not depend on anti-sera production or availability of human sera and thus reactives can be produced in unlimited amounts.

CONCLUSION

This sensitive and specific Lol p 1 assay will be helpful both for quantifying the group 1 allergen content of Pooideae pollen extracts intended for clinical use and for studying cross-reactivities among pollen extracts.

Alternative splicing of the proadrenomedullin gene results in differential expression of gene products

The adrenomedullin (AM) gene codifies for two bioactive peptides, AM and proAM N-terminal 20 peptide (PAMP). We have found two forms of the AM mRNA. Form A is devoid of introns and results in a prohormone containing both peptides. Form B retains the third intron, which introduces a premature stop codon, producing a shorter prohormone with only PAMP. Tissues with a higher B/A ratio were more immunoreactive for PAMP than for AM. The form B message was found in the cytoplasmic compartment, thus excluding that the longer message was a result of contaminating nuclear mRNA. Form B was found in cells that express PAMP but not AM. mRNA expression in a variety of cell lines was investigated by ribonuclease protection assay and form B was found in significant amounts in two of them. Treatments that modify AM expression, such as exposure to hypoxia, were shown to change the B/A ratio and the relative secretion of AM and PAMP, indicating that the splicing mechanism for AM can be modulated and is physiologically relevant. Analysis of the sequence of the third intron and the fourth exon of the AM gene found motifs compatible with a highly regulated alternative splicing mechanism.

A structural approach into human tryptophan hydroxylase and its implications for the regulation of serotonin biosynthesis

Tryptophan hydroxylase (TPH) catalyzes the 5-hydroxylation of tryptophan, which is the first step in the biosynthesis of indoleamines (serotonin and melatonin). Serotonin functions mainly as a neurotransmitter, whereas melatonin is the principal hormone secreted by the pineal gland. TPH belongs to the family of the aromatic amino acid hydroxylases, including phenylalanine hydroxylase (PAH) and tyrosine hydroxylase (TH), which all have a strict requirement for dioxygen, non-heme iron (II) and tetrahydrobiopterin (BH4). During the last three years there has been a formidable increase in the amount of structural information about PAH and TH, which has provided new insights into the active site structure, the binding of substrates, inhibitors and pterins, as well as on the effect of disease-causing mutations in these hydroxylases. Although structural information about TPH is not yet available, the high sequence homology between the three mammalian hydroxylases, notably at the catalytic domains, and the similarity of the reactions that they catalyze, indicate that they share a similar 3D-structure and a common catalytic mechanism. Thus, we have prepared a model of the structure of TPH based on the crystal structures of TH and PAH. This structural model provides a frame for understanding the specific interactions of TPH with L-tryptophan and substrate analogues, BH4 and cofactor analogues, L-DOPA and catecholamines. The interactions of these ligands with the enzyme are discussed focusing on the physiological and pharmacological regulation of serotonin biosynthesis, notably by tryptophan supplementation therapy and substitution therapy with tetrahydrobiopterin analogues (positive effects), as well as the effect of catecholamines on TPH activity in L-DOPA treated Parkinson's disease patients (enzyme inhibition).

[What is the best way to recruit patients for primary care programs of children's oral health?]

OBJECTIVE

To analyse the results obtained by two systems of recruiting patients in terms of: number of patients recruited, number of consultations requested, and number of half-yearly check-ups performed.

DESIGN

Retrospective and observational.

SETTING

Primary care.

PATIENTS

1868 school-children from 6 to 14 in the Burela Health Area (Lugo).

MAIN RESULTS

The system based on the health centre recruited 616 children and led to 759 requests for consultation; whereas the system based on the school recruited 1252 children and 507 requests (123% vs 40%; p < 0.05). 23% of the school-children attended their half-yearly check-up under the first system, while 21% did so under the second.

CONCLUSIONS

Check-ups of children at the health centre in their parents' presence seems to answer better the objective of introducing the bucco-dental health programme into the Health Area's child population.

Rhinoconjunctivitis and occupational asthma caused by Diplotaxis erucoides (wall rocket)

Wall rocket (Diplotaxis erucoides) is a common Crucifera plant that grows in European and American vineyards and olive groves. We present the cases of 2 farmers with rhinoconjunctivitis and asthma related to wine-growing tasks during D erucoides pollination (March-April). The aim of this work was to demonstrate that occupational symptoms were caused by D erucoides pollen sensitization. Cutaneous tests, specific IgE measurements, conjunctival and bronchial provocation tests, and peak-flow measurements during working days were performed.

Height velocity in Argentinean girls with Turner's syndrome

Height velocities from birth to maturity derived from 1,049 height increments measured over intervals 0.85-1.15 years were studied from a sample of 187 patients with Turner's syndrome (TS) diagnosed on the basis of karyotype. Length of follow up in each girl varied from 1.0 to 11.0 years. Cross-sectional analysis showed a relatively stable growth velocity during pubertal ages. However, longitudinal analysis of individual growth curves showed the existence of a small growth spurt in 37 out of 47 girls with available data during pubertal years. Mean peak height velocity (PHV) of this spurt was 5.7 cm/year, SD 1.34; mean age at PHV was 12.66 years, SD 1.70. Selected percentiles were calculated using the least mean squares (LMS) method. Results show that a small growth spurt in girls with TS may be more frequent than previously thought.

The effect of substrate, dihydrobiopterin, and dopamine on the EPR spectroscopic properties and the midpoint potential of the catalytic iron in recombinant human phenylalanine hydroxylase

Phenylalanine hydroxylase (PAH) is a tetrahydrobiopterin (BH(4)) and non-heme iron-dependent enzyme that hydroxylates L-Phe to L-Tyr. The paramagnetic ferric iron at the active site of recombinant human PAH (hPAH) and its midpoint potential at pH 7.25 (E(m)(Fe(III)/Fe(II))) were studied by EPR spectroscopy. Similar EPR spectra were obtained for the tetrameric wild-type (wt-hPAH) and the dimeric truncated hPAH(Gly(103)-Gln(428)) corresponding to the "catalytic domain." A rhombic high spin Fe(III) signal with a g value of 4.3 dominates the EPR spectra at 3.6 K of both enzyme forms. An E(m) = +207 +/- 10 mV was measured for the iron in wt-hPAH, which seems to be adequate for a thermodynamically feasible electron transfer from BH(4) (E(m) (quinonoid-BH(2)/BH(4)) = +174 mV). The broad EPR features from g = 9.7-4.3 in the spectra of the ligand-free enzyme decreased in intensity upon the addition of L-Phe, whereas more axial type signals were observed upon binding of 7,8-dihydrobiopterin (BH(2)), the stable oxidized form of BH(4), and of dopamine. All three ligands induced a decrease in the E(m) value of the iron to +123 +/- 4 mV (L-Phe), +110 +/- 20 mV (BH(2)), and -8 +/- 9 mV (dopamine). On the basis of these data we have calculated that the binding affinities of L-Phe, BH(2), and dopamine decrease by 28-, 47-, and 5040-fold, respectively, for the reduced ferrous form of the enzyme, with respect to the ferric form. Interestingly, an E(m) value comparable with that of the ligand-free, resting form of wt-hPAH, i.e. +191 +/- 11 mV, was measured upon the simultaneous binding of both L-Phe and BH(2), representing an inactive model for the iron environment under turnover conditions. Our findings provide new information on the redox properties of the active site iron relevant for the understanding of the reductive activation of the enzyme and the catalytic mechanism.

Putting spatial attention on the map: timing and localization of stimulus selection processes in striate and extrastriate visual areas

This study investigated the cortical mechanisms of visual-spatial attention in a task where subjects discriminated patterned targets in one visual field at a time. Functional magnetic imaging (fMRI) was used to localize attention-related changes in neural activity within specific retinotopic visual areas, while recordings of event-related brain potentials (ERPs) traced the time course of these changes. The earliest ERP components enhanced by attention occurred in the time range 70-130 ms post-stimulus onset, and their neural generators were estimated to lie in the dorsal and ventral extrastriate visual cortex. The anatomical areas activated by attention corresponded closely to those showing increased neural activity during passive visual stimulation. Enhanced neural activity was also observed in the primary visual cortex (area V1) with fMRI, but ERP recordings indicated that the initial sensory response at 50-90 ms that was localized to V1 was not modulated by attention. Modeling of ERP sources over an extended time range showed that attended stimuli elicited a long-latency (160-260 ms) negativity that was attributed to the dipolar source in area V1. This finding is in line with hypotheses that V1 activity may be modulated by delayed, reentrant feedback from higher visual areas.

Adverse reactions to injectable aesthetic microimplants

New inert materials such as polymerized silicones, Bioplastique, Artecoll, and Dermalive are now being used as injectable aesthetic microimplants. These substances are better than the old ones because they tend not to migrate and do not usually produce much of a host immune response. Adverse reactions after injection of these materials are rare, although there are a few reported cases as a result of bad technique or anomalous granulomatous reactions. We report on four patients with unsightly results after cosmetic microimplants, including one of Artecoll, one of Dermalive (to the best of our knowledge, the latter is the first such case reported), and two of silicone. This report describes the histopathologic features of cutaneous reactions to these injectable aesthetic materials.

Efficacy of N-acetylcysteine to reduce the effects of aflatoxin B1 intoxication in broiler chickens

N-acetylcysteine (NAC) has been used safely in humans and in other mammals as an antidote against several toxic and carcinogenic agents, including aflatoxin B1 (AFB1). The aim of this study was to evaluate the capability of dietary supplementation with NAC to ameliorate the effects of subacute intoxication with AFB1 in broiler chickens. One hundred twenty male Hubbard 1-d-old chickens were allocated into one of four dietary treatments: 1) control group without treatment, 2) purified AFB1 added to diet (3 mg/kg of feed) for 21 d, 3) NAC (800 mg/kg BW, daily), or 4) AFB1 plus NAC at the same doses as Groups 2 and 3. Broilers treated with AFB1 plus NAC were shown to be partially protected against deleterious effects on BW (57.8%), daily weight gain (49.1%), feed conversion index (21.4%), plasma and hepatic total protein concentration (45.2, 66.7%), plasma alanine aminotransferase (67.4%), hepatic glutathione-S-transferase (18.8%), and reduced glutathione liver concentration (75.0%). In addition, they showed less intense liver fading, friable texture, and microvesicular steatosis. In the kidney, thickening of glomerular basement membrane was also less severe in NAC+AFB1-treated chickens than in AFB1-treated chickens. Our results suggest that NAC provided protection against negative effects on performance, liver and renal damage, and biochemical alterations induced by AFB1 in broiler chickens. Effects of NAC alone on chick performance were also evaluated. Addition of NAC to diet (800 mg/kg BW) did not negatively affect feed consumption, conversion index, or serum chemistry and did not induce structural changes in the liver or kidney.

[Selective training of respiratory muscles in patients with chronic heart failure]

BACKGROUND

Patients with chronic heart failure have a lower inspiratory muscle strength and fatigue endurance.

AIM

To assess the effects of selective training of respiratory muscles in patients with heart failure.

PATIENTS AND METHODS

Twenty patients with stable chronic heart failure, aged 58.3 +/- 3 years with an ejection fraction of 28 +/- 9%, were subjected to respiratory muscle training with threshold valves. The load was fixed in 30% of maximal inspiratory pressure (PImax) in 11 and in 10% of PImax in nine. Two sessions of 15 minutes, 6 days per week, during 6 weeks were done. Degree of dyspnea (Mahler score), maximal oxygen uptake, distance walked in 6 minutes, respiratory muscle function and left ventricular ejection fraction were measured before and after training.

RESULTS

Both training loads were associated to an improvement in dyspnea (+2.7 +/- 1.8 and +2.8 +/- 1.8 score points with 30% PImax and 10% PImax respectively), maximal oxygen uptake (from 19 +/- 3 to 21.6 +/- 5 and from 16 +/- 5 to 18.6 +/- 7 ml/kg/min with 30% PImax and 10% PImax respectively, p < 0.05), PImax (from 78 +/- 22 to 99 +/- 22 and from 72 +/- 34 to 82.3 cm H20 with 30% PImax and 10% PImax respectively), sustained PImax (from 63 +/- 18 to 90 +/- 22 and from 58 +/- 3 to 69 +/- 3 cm H20 with 30% PImax and 10% PImax respectively), and maximal sustained load (from 120 +/- 67 to 195 +/- 47 and from 139 +/- 120 to 192 +/- 154 g with 30% PImax and 10% PImax respectively). The distance walked in 6 min only increased in subjects trained at 30% PImax (from 451 +/- 78 to 486 +/- 68 m).

CONCLUSIONS

Selective training of respiratory muscles results in a functional improvement of patients with chronic heart failure.

In situ detection of unexpected patterns of mutant p53 gene expression in non-small cell lung cancers

Many solid tumors, including non-small cell lung cancers (NSCLCs), are characterized by heterogenous expression of p53 protein in the neoplastic cells. To analyse the molecular implications of this finding, we examined topographic distribution of p53 mutations using in situ polymerase chain reaction (PCR) in primary NSCLCs, showing distinct patterns of variable p53 overexpression by immunohistochemistry. Unique sets of primers for each mutation were designed, and optimal PCR conditions were determined by standard PCR using DNA from cloned mutants or cell lines established from these tumors. All tumor cell nuclei, regardless of the status of p53 overexpression, demonstrated homogeneous distribution of mutant p53 with specific primers, indicating that only subgroups of the mutated cells overexpressed p53 protein. In situ reverse transcription (RT)-PCR was applied to detect mutant mRNA in the individual tumor cells using specific primers. We found that in each case the distribution of mutant p53 mRNA coincided with that of immunohistochemical overexpression of p53 protein. Our results suggest that the regulation of mutant p53 expression, but not the genotype, is heterogeneous in the neoplastic cells. The topographic genomapping of p53 in NSCLC using in situ PCR provides a novel approach to view molecular mechanisms of lung carcinogenesis.

[The efficacy and safety of continuous epidural analgesia versus intradural-epidural analgesia during labor]

OBJECTIVE

To determine the efficacy and safety of intradural-epidural analgesia in comparison with continuous epidural analgesia during labor and childbirth.

PATIENTS AND METHOD

Forty-two women whose labor began spontaneously were enrolled and distributed randomly in two groups. The intradural-epidural analgesia group (IEA, n = 21) received 25 microgram of intradural fentanyl with 2.5 mg of isobaric bupivacaine with adrenalin, after which analgesia was maintained with epidural administration of one 8 mL bolus of 0.125% bupivacaine, followed by perfusion of a balanced concentration at a rate of 8 ml/h. Patients in the continuous epidural analgesia group (CEA, n = 21) were given 8 ml of 0.25% bupivacaine with adrenalin; the epidural perfusion of 0.125% bupivacaine and 1 microgram/ml of fentanyl was started at the same rate as in the IEA group. We recorded pain as assessed on a visual analog scale, extension of sensory and motor block, maternal hemodynamic constants, number of boluses of bupivacaine used, total doses of bupivacaine and oxytocin, instruments needed for childbirth, and side effects (pruritus, nausea and vomiting).

RESULTS

Analgesic efficacy during the first 30 minutes was greater in the IEA group. The total dose of bupivacaine, required top-up boluses, and the extension of sensory block at 30 minutes, one hour and two hours were also significantly less in the IEA group. The incidence of pruritus was higher in the IEA group. No significant differences were observed for other variables.

CONCLUSIONS

Intradural-epidural analgesia provides effective analgesia for labor, with rapid onset, reduced extension of sensory block, lower total doses of local anesthetics and few side effects.

[Hyperuricemia as a marker for anaerobic threshold in chronic cardiac failure]

BACKGROUND

Patients with chronic cardiac failure often have elevated plasma uric acid levels, that are associated to a dismal prognosis.

AIM

To investigate possible metabolic mechanisms to explain elevated uric acid levels in these patients.

PATIENTS AND METHODS

Eighteen patients with chronic cardiac failure aged 61 +/- 10 years old, without gout or renal failure and not using high doses of diuretics (equal or less than 80 mg/day furosemide or 50 mg/day hydrochlorothiazide) were studied. Plasma uric acid levels were correlated with anaerobic threshold, maximal oxygen uptake, plasma noradrenaline and creatinine and left ventricular ejection fraction, measured radioisotopically.

RESULTS

Mean maximal oxygen uptake was 16.6 +/- 4.2 ml/kg/min. There was a negative correlation between uric acid levels and maximal oxygen uptake or maximal oxygen uptake/body surface area (r = 0.521 and -0.533 respectively, p < 0.05). Patients with uric acid levels over 7 mg/dl had a lower anaerobic threshold than patients with lower levels (9.81 +/- 2.41 and 13.08 +/- 3.28 ml/kg/min respectively, p < 0.05). No significant differences in maximal oxygen uptake were observed in these two groups of patients (15.5 +/- 4.24 and 18.08 +/- 3.86 ml/kg/min respectively). Uric acid levels did not correlate with plasma noradrenaline, creatinine or left ventricular ejection fraction.

CONCLUSIONS

These results suggest that a defect in cellular oxygenation contributes to the elevation of plasma uric acid levels in patients with chronic cardiac failure.

Influence of amino acids on okadaic acid production

Okadaic acid (OA) (1)) was the first example of a group of polyether toxins known to be produced by marine microalgae, which are responsible for the natural phenomena known as Diarrhetic Shellfish Poisoning (DSP) red tides. It is also a highly selective inhibitor of protein phosphatases type 1 (PP1) and 2A (PP2A), as well as being a potent tumour promoter. For these reasons, OA is an extremely useful tool for studying cellular processes and an important standard for polluted shellfish control. In this paper, we report on a double objective: to improve the production of toxins and verify the apparent participation of amino acids in the formation of these polyethers by monitoring their influence on the promotion of growth, total cell yield and increased in toxicity in Prorocentrum lima of the PL2V strain in batch cultures, in a modified K medium.

Effect of cooking temperatures on chemical changes in species of organic arsenic in seafood

The concentrations of arsenobetaine (AB), tetramethylarsonium ion (TMA(+)), and trimethylarsine oxide (TMAO) were determined in samples of sole, dory, hake, and sardine, raw and after being subjected to cooking processes--baking, frying, and grilling--at various temperatures. In all cases, the temperature attained inside the product during the cooking process was measured. The arsenic species extracted from the samples with methanol/water were separated by means of a column switching technique between a PRP-X100 column and a PRP-X200 column. AB was detected by hydride generation atomic absorption spectrometry, whereas TMA(+) and TMAO were detected by hydride generation atomic fluorescence spectrometry. The results obtained showed that, in all of the types of seafood studied, TMA(+) appeared after cooking, possibly because heating facilitates decarboxylation of AB to TMA(+).

Treatment of keloids by high-dose-rate brachytherapy: A seven-year study

PURPOSE

To analyze the results obtained in a prospective group of patients with keloid scars treated by high-dose-rate (HDR) brachytherapy with or without surgery.

METHODS AND MATERIALS

One hundred and sixty-nine patients with keloid scars were treated with HDR brachytherapy between December 1991 and December 1998. One hundred and thirty-four patients were females, and 35 were males. The distribution of keloid scars was as follows: face, 77; trunk, 73; and extremities, 19. The mean length was 4.2 cm (range 2-22 cm), and the mean width 1.8 cm (range 1.0-2.8 cm). In 147 patients keloid tissues were removed before HDR brachytherapy treatment, and in 22 HDR brachytherapy was used as definitive treatment. In patients who underwent prior surgery, a flexible plastic tube was put in place during the surgical procedure. Bottoms were used to fix the plastic tubes, and the surgical wound was repaired by absorbable suture. HDR brachytherapy was administered within 30-60 min of surgery. A total dose of 12 Gy (at 1 cm from the center of the catheter) was given in four fractions of 300 cGy in 24 h (at 09.00 am, 15.00 pm, 21.00 pm, and 09.00 am next day). Treatment was optimized using standard geometric optimization. In patients who did not undergo surgery, standard brachytherapy was performed, and plastic tubes were placed through the skin to cover the whole scar. Local anesthesia was used in all procedures. In these patients a total dose of 18 Gy was given in 6 fractions of 300 cGy in one and a half days (at 9.00 am, 3.00 pm, and 9.00 pm; and at 9.00 am, 3.00 pm, and 9.00 pm next day). No further treatment was given to any patient. Patients were seen in follow-up visits every 3 months during the first year, every 6 months in the second year, and yearly thereafter. No patient was lost to follow-up. Particular attention was paid to keloid recurrence, late skin effects, and cosmetic results.

RESULTS

All patients completed the treatment. After a follow-up of seven years, 8 patients (4.7%) had keloid recurrences. Five of these had undergone prior surgery (local failure rate 3.4%), and 3 had received only HDR brachytherapy (local persistence rate 13.6%). Cosmetic results were considered to be good or excellent in 130/147 patients treated with prior surgery and in 17/22 patients without surgery. Skin pigmentation changes were observed in 10 patients, and telangiectasias in 12 patients. No late effects such as skin atrophy or skin fibrosis were observed during the 7 years of follow-up.

CONCLUSIONS

HDR brachytherapy is an effective treatment for keloid scars. It is well tolerated and does not present significant side effects. The brachytherapy results were more successful in patients who underwent previous surgical excision of keloid scar than in patients without surgery. We favor HDR brachytherapy rather than superficial X-rays or low energy electron beams in keloid scars, because HDR provides a better selective deposit of radiation in tissues and a lower degree of normal tissue irradiation. Other advantages of high-dose-rate brachytherapy over low-dose-rate brachytherapy are its low cost, the fact that it can be performed on an outpatient basis, its excellent radiation protection, and the better dose distribution obtained. From the clinical perspective, the technique provides a high local control rate without significant sequelae or complications.

[Epidemiology of chronic inflammatory bowel disease in Gijón, Asturias]

AIMS

To determine several aspects of the epidemiology of chronic inflammatory bowel disease (IBD), including distribution of the various forms of IBD, sex, age at diagnosis considering lag-time to diagnosis, criteria used in the diagnosis, the relationship between educational level and activity, familial aggregation, phenotype (site and clinical type), number of admissions and mean hospital stay/year, surgical requirements and mortality.

PATIENTS AND METHODS

We carried out a retrospective (1954-1993) and prospective (1994-97) descriptive epidemiologic population study, in the fifth health district of Gijón in Asturias (Spain), with 225,798 inhabitants. A total of 595 patients diagnosed with chronic IBD according to the diagnostic criteria described by Lennard-Jones and Truelove for Crohn's disease (CD) and ulcerative colitis (UC) and according to Ashley B. Price's criteria for indeterminate colitis (IC) were studied. In all patients a complete clinical follow-up was performed.

RESULTS

During the study period, we diagnosed 595 patients with IBD [305 patients with UC (51.3%), 272 (45.7%) patients with CD and 18 (3%) with IC]. Sex distribution was 287 females (48.2%) and 308 males (51.8%), with a male/female ratio of 1.07. Mean age at presentation was 38.79 +/- 17.44 years (UC: 43.37 +/- 17.55; CD: 33.98 +/- 16.16; IC: 33.73 +/- 13.48), p = 0.000. Age at onset prior to diagnosis was as follows: UC: 42.03; CD: 30.47; IC: 30.99 (p = 0.000). Diagnostic criteria used in UC was symptomatic in 99.01% (p = ns), endoscopic in 95.04% (p = 0.000), and pathologic in 87.21% (p = 0.000); in CD diagnostic criteria used was radiologic in 85.29% (p = 0.000). A total of 29.1% of patients with UC and 66.7% of those with CD had higher education (p = 0.0005). Family history was found in 9.8%. Anatomical site was as follows: in UC: rectum 21%, 28.2% rectum and sigmoid, 22.3% left colitis, 4.2% distal to hepatic flexure and 24% pancolitis; in CD: 32.72% terminal ileum, 19.11% colon, 37.13% ileo-colon, 11.02% extensive intestinal and 3.67% gastro-duodenal. A total of 8.37% of patients with UC and 14.51% of those with CD had been hospitalized during the previous 4 years; mean hospital stay was 1.63 days in UC and 2.27 days in CD. The mean surgical requirements were 0.54 +/- 1.08 (31.59%); UC: 0.11 +/- 0.36 (10.2%); CD: 1.04 +/- 1.38 (56.25%), p = 0.000. The mortality rate was 48.73 deaths/1,000 inhabitants (UC: T = 65.57; CD: T = 33.08; IC:T= 0) p = ns. The standardized mortality ratio was 4.83 (UC: 6.51; CD: 3.28).

CONCLUSIONS

We highlight the uniformity of the distribution of IBD in relation to types of disease and sex. Patients with CD had a higher level of education. Genetic components play an important role in these diseases and familial aggregation was high, especially in CD. Complicated situations are infrequent in this group of patients. Morbidity was higher in patients with CD as reflected by surgical requirements and hospital stay. Mortality was lower in CD than in UC.

Kinetic study of transformations of arsenic species during heat treatment

The combination of temperatures and pH levels applied in domestic or industrial cooking and in the sterilization of seafood might cause the transformation of certain species of arsenic into other more toxic species, which could pose a risk to the consumer. To clarify the effect of the temperatures traditionally used in cooking or sterilization on the stability of the various species of arsenic, a kinetic study was carried out, using standards of arsenobetaine (AB), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), trimethylarsine oxide (TMAO), tetramethylarsonium ion (TMA(+)), and arsenocholine (AC) heated at different temperatures (85--190 degrees C) and for different treatment times. Various pH levels (4.5, 5.5, 6.5, and 8.0) were applied during the heating process. The results obtained indicated that there were no transformations of arsenic species after temperature treatments up to 120 degrees C. However, when temperatures between 150 and 190 degrees C were used, a partial decomposition of AB was achieved, producing TMAO at 150 degrees C and TMAO and TMA(+) at temperatures of 160 degrees C or above, in proportions that varied according to the temperature and duration of the heat treatment.

Cytogenetics in acute lymphoblastic leukemia in Mexican children: an institutional experience

BACKGROUND

Cytogenetic studies in acute lymphoblastic leukemia (ALL) have identified numerical and structural chromosomal abnormalities related to the disease's pathophysiologic characteristics. These findings correlate with prognosis and response to treatment in ALL patients. The purpose of this study was to define the frequency of chromosomal abnormalities in a group of Mexican children with ALL and to compare these data with those reported in the literature.

METHODS

Bone marrow chromosome studies with GTG bands were performed in 150 pediatric patients with ALL who were naive to antileukemic treatment and aged from 5 months to 16 years; the majority was diagnosed as L1.

RESULTS

Among 131 patients, 30 (22.9%) karyotypes were normal and the remaining 101 (77.1%) had abnormal karyotypes with numerical and/or structural abnormalities. Among patients with numerical abnormalities, the most frequent karyotypes were hyperdiploidy with 51-65 chromosomes (30 patients) and hyperdiploidy with 47-50 chromosomes (18 patients). Among recurrent, non-random, and primary structural abnormalities, the most frequent was t(9;22), followed by t(1;19). Aberrations involving band 11q23 were not detected, and only one of two patients with L3 had the t(8;14). Of the secondary non-random abnormalities, dup(1q), del(6q), and i(7)(q10) were found.

CONCLUSIONS

The frequency and type of chromosomal abnormalities found was comparable to those reported in the literature with similar methodology and pediatric populations; however, the number of cases analyzed should be increased to create a database of Mexican children with ALL, and several patients require molecular analysis to identify chromosomal abnormalities not detected through conventional cytogenetic studies.

Differential expression of the early lung cancer detection marker, heterogeneous nuclear ribonucleoprotein-A2/B1 (hnRNP-A2/B1) in normal breast and neoplastic breast cancer

Heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNP-A2/B1) is highly expressed during critical stages of lung development and carcinogenesis. To determine if the expression of hnRNP-A2/B1 is an informative biomarker in breast carcinogenesis, we analyzed hnRNP-A2/B1 overexpression by immunohistochemistry in archived specimens. Expression was detected in 48/85 (56.5%) primary invasive breast cancers and 7/72 (9.7%) specimens of normal breast tissue. Northern analysis of breast cancer cells also demonstrated higher level of hnRNP-A2/B1 expression compared to normal or transformed breast cells. Expression of hnRNP-A2/B1 in breast cancer cells was decreased by exposure to retinoids coordinately with decreased cell growth. These results warrant further evaluation of hnRNP-A2/B1 as a marker of breast carcinogenesis.