Cutaneous leishmaniasis in Cavia porcellus (guinea pig): case report / Leishmaniose cutânea em Cavia porcellus (cobaia): relato de caso

Leishmaniasis is a parasitic disease of worldwide spread. It is caused by protozoa of the genus Leishmania and is transmitted to animals and humans through the bite of sand flies. In Brazil, leishmaniasis is one of the zoonoses of major importance and expansion. The objective of this work is to describe the clinical, pathological, immunohistochemical and molecular findings of cutaneous leishmaniasis by Leishmania enriettii in guinea pig (Cavia porcellus). Three animals had nodular and alopecia lesions on the muzzle, ears and ulcerated lesions on the distal extremities of the pelvic limbs. The males (2) also had diffuse thickening of the scrotal skin. Samples of the ulcerated cutaneous lesions were evaluated by cytology which were observed as amastigote forms of Leishmania. One of the animals was euthanized and necropsied. Histopathology showed abundant dermal infiltrate of macrophages, plasma cells, lymphocytes and multinucleated giant cells. Numerous macrophages contained parasitoid vacuoles with amastigote forms, evidenced by immunohistochemical examination. The molecular characterization based on the SSUrDNA gene identified the species as L. enrietti. The diagnosis of cutaneous leishmaniasis in these cases was based on pathological findings and confirmed by immunohistochemistry, PCR and sequencing.(AU)

A leishmaniose é uma doença parasitária de distribuição mundial. É causada por protozoários do gênero Leishmania e é transmitida para animais e seres humanos por meio da picada de flebotomíneos. No Brasil, a leishmaniose é uma das zoonoses de maior importância e expansão. O objetivo deste trabalho é descrever os achados clínicos, patológicos, imuno-histoquímicos e moleculares de leishmaniose cutânea por Leishmania enriettii em cobaia (Cavia porcellus). Três animais apresentavam lesões nodulares e alopécicas no focinho e orelhas, além de lesões ulceradas nas extremidades distais dos membros pélvicos. Nos machos (2), foi observado espessamento difuso da pele escrotal. Amostras das lesões cutâneas ulceradas foram avaliadas por citologia, nas quais foram observadas formas amastigotas de Leishmania. Um dos animais foi submetido à eutanásia e necropsiado. Na histopatologia, foi observado infiltrado dérmico abundante de macrófagos, plasmócitos, linfócitos e com células gigantes multinucleadas. Numerosos macrófagos continham vacúolos parasitóforos com formas amastigotas, evidenciados por meio do exame de imuno-histoquímica. A caracterização molecular baseada no gene de SSUrDNA identificou a espécie como L. enrietti. O diagnóstico de leishmaniose cutânea nesses casos foi baseado nos achados patológicos e confirmado pelas técnicas de imuno-histoquímica, PCR e sequenciamento.(AU)

Familial hypobetalipoproteinemia: analysis of three Spanish cases with two new mutations in the APOB gene.

Extremely low LDL-cholesterol concentrations are very unusual and generally related with comorbidities accompanying malnutrition. Less frequently low LDL-cholesterol levels result from mutations in the APOB, PCSK9, ANGPTL3, SAR1B and MTTP genes (primary hypobetalipoproteinemia). We investigated three patients with plasma LDL-cholesterol levels below the fifth percentile of the Spanish population. We recorded data on demographic and anthropometric characteristics, life style habits, physical examination, liver ultrasound and lipid and lipoprotein levels, in the probands and their first-degree relatives. Secondary causes of hypocholesterolemia were ruled out by clinical study, complementary tests and follow-up. The APOB, MTTP and SAR1B genes were sequenced. Patients were found to be heterozygotes for point mutations located in the exon 26 of the APOB gene. One patient, with fatty liver, carried a previously described mutation (c.7600C>T) (Arg2507X), causing the formation of truncated Apo B-55.25. The other two mutations producing truncations are new. One asymptomatic patient carried the Arg3672X (Apo B-80.93) and the other with fatty liver and steatorrhea carried the Ser2184fsVal2193X (Apo B-48.32). Our study reinforces the concept that in the heterozygous carriers of truncated Apo Bs, the clinical manifestations of FHBL are dependent on the size of the truncations.

Use of the gluteus maximus muscle as the neosphincter for restoration of anal function after abdominoperineal resection.

BACKGROUND: Our aim was to evaluate complications and long-term functional outcome in patients who had sphincter reconstruction using the gluteus maximus muscle as the neosphincter after abdominoperineal resection for rectal cancer treatment. METHODS: Seven patients underwent reconstruction from 2000 to 2010. First, the sigmoid colon was brought down to the perineum as a perineal colostomy, with the procedure protected by a loop ileostomy. Reconstruction of the sphincter mechanism using the gluteus maximus took place 3 months later, and after another 8-12 weeks, the loop ileostomy was closed. We studied the functional outcome of these interventions with follow-up interviews of patients and objectively assessed anorectal function using manometry and the Cleveland Clinic Florida (Jorge-Wexner) fecal incontinence score. RESULTS: The mean follow-up was 56 months (median 47; range 10-123 months). One patient had a perianal wound infection and another had fibrotic stricture in the colocutaneous anastomosis that required several digital dilatations. Anorectal manometry at 3-month follow-up showed resting pressures from 10 to 18 mm Hg and voluntary contraction pressures from 68 to 187 mm Hg. Four patients had excellent sphincter function (Jorge-Wexner scores ≤5). CONCLUSIONS: Our preliminary results show that sphincter reconstruction by means of gluteus maximus transposition can be effective in restoring gastrointestinal continuity and recovering fecal continence in patients who have undergone APR with permanent colostomy for rectal cancer. Furthermore, the reconstruction procedure can be performed 2-4 years after the APR.

Long-term-release GnRH agonists postpone puberty in domestic cats.

The aim of this study was to assess the efficacy and safety of deslorelin acetate implants on domestic queen puberty postponement. Thirty, 114.4 ± 12.7 days old, 1.5 ± 0.1 kg prepubertal crossbred female cats were included in this study. The animals were kept under a positive photoperiod and randomly assigned to deslorelin acetate 4.7 mg SC implants (n = 15) or to a non-treated control group (n = 15). The queens were followed up daily and weighed weekly until puberty. Vaginal cytology was also carried out three times a week. Puberty was diagnosed by the presence of the typical oestrous behaviour and vaginal cytology findings. At puberty, ovariectomy was performed and the gonads grossly described. Age (281.2 ± 21.6 vs 177.8 ± 10.8; p < 0.01) but not weight (2.6 ± 0.1 vs 2.5 ± 0.1; p > 0.1) at puberty differed between the deslorelin and control groups, respectively. One deslorelin-treated female showed an oestrous response and another showed clinical signs of pyometra after the implants. Deslorelin-treated ovaries appeared small, while control gonads were normal. It was concluded that long-term-release deslorelin, administered at approximately 50% adult body weight, postponed feline puberty without altering growing rate.

A single administration of the GnRH antagonist acyline inhibits basal and GnRH-stimulated serum testosterone concentrations in male dogs.

The objective of this study was to describe testosterone (T) response to GnRH challenge in antagonist-treated dogs over a 30-day period. Eight mongrel dogs were randomly assigned to either the GnRH antagonist acyline 330 µg/kg sc (ACY; n = 4) or a placebo group (PLA; n = 4). The dogs were serially challenged with the GnRH agonist, buserelin 0.2 µg/kg sc on days -1, 1, 3, 7, 10, 14, 21 and 30. On these days, blood samples for T determinations were collected before (-30 min) and 60, 120 and 180 min after the agonist injection. Basal (-30 min) and post-GnRH agonist stimulation T values were compared by anova for repeated measures. Before treatments (day -1), there were no differences in basal T serum concentrations between groups (p > 0.1). After treatments, basal T showed a significant interaction between treatment and day (p < 0.05). Furthermore, when both groups were analysed independently, basal T varied in the ACY (p < 0.01) but not in the PLA group (p > 0.1). On day -1, before treatments, the stimulation tests had only a time effect (p = 0.05) although on days 1 (p < 0.01), 3 (p < 0.01), 7 (p < 0.01), 10 (p < 0.01) and 14 (p < 0.05), the response to the agonist differed between groups, becoming similar on days 21 (p > 0.05) and 30 (p > 0.05). It was concluded that, in dogs, a single administration of the GnRH antagonist prevented canine gonadal axis to physiologically respond to agonistic challenge during 14 days.

Domestic queens under natural temperate photoperiod do not manifest seasonal anestrus.

Domestic cat seasonality between the tropics and the arctic zones is scarcely described and results are inconsistent. The aim of this study was to describe domestic feline seasonal patterns under a natural temperate photoperiod. A total of 372 estrous cycles were studied in 34 post pubertal cats during 900 days. The queens were housed in a cat colony (31°25' South Latitude, 64°11' West Longitude), acclimated under natural photoperiod and daily observed for reproductive behavior. Vaginal cytology was conducted three times a week. For each cat the number of estrous cycles and days in estrus per month for each year were recorded. The months of the year were grouped in four periods of 3 months each according to day length and photoperiod. Comparisons of estrous days among periods were performed by ANOVA for repeated measures. All the cats had estrous cycles throughout the year without intervals of anestrus. Mean number of estrous days differed among the periods (P<0.01), those of long day length and ascending photoperiod being greater (12.5±0.6) to those of descending photoperiod either with long (8.9±0.7) or short (9.3±0.7) days. When the two periods with ascending day lengths were merged and compared to the two periods with descending day lengths merged, the number of estrous days were greater when day length ascended (P<0.01). Nearly 60% of the estrous cycles occurred during the periods of ascending day length. It is concluded, that domestic cats under natural temperate photoperiod have estrous cycles throughout the year showing peak activity the months with increasing photoperiod.

Doppler ultrasonographic assessment of maternal and fetal blood flow in abnormal canine pregnancy.

The aim of this study was to describe the changes of uterine artery, umbilical artery and fetal abdominal aorta, renal and internal carotid arteries blood flow in abnormal canine pregnancy. Twenty-two, Brucella-negative pregnant bitches were retrospectively classified into abnormal (which had either interrupted their pregnancy between days 52 and 60 or had perinatal death >60% of the litter; n=11) and normal (which had delivered healthy puppies at term; n=11). In all the animals, color and pulsed-wave Doppler examinations of uterine artery were conducted every 10 days from Day 20 to 50 from estimated luteinizing hormone peak. Doppler ultrasonography was also conducted in the fetuses to assess umbilical artery, abdominal aorta, renal and internal carotid arteries from Day 40 to 60 of gestation. Throughout the study, resistance index (RI) of uterine, umbilical and fetal renal arteries decreased up to -15% compared to -36% (P<0.01), -11% compared to -23% (P<0.05) and 2% compared to -13% (P<0.05), respectively in the abnormal and normal bitches. Fetal abdominal aorta and internal carotid did not differ between groups (P>0.05). It is concluded that in dogs, uterine artery, umbilical artery and fetal renal artery RI differ between normal and abnormal gestation being useful for the prediction of adverse obstetric outcome.

Long-term melatonin treatment prolongs interestrus, but does not delay puberty, in domestic cats.

The objective was to assess the efficacy and safety of long-term administration of melatonin (either as an implant or given orally) on interestrus intervals in domestic cats. Additionally, the effect of melatonin implants on puberty postponement was studied. For these purposes, two randomized controlled trials were conducted. In the first, 68 interestrus intervals (in 28 postpubertal queens) were studied, and in the second, 32 prepubertal female cats were used. During anovulatory interestrus intervals (27 ovulatory interestrus intervals were excluded), postpubertal cats were assigned to the following three treatments: melatonin implant 18 mg/cat SC (n = 17; MEI); melatonin tablets, 4 mg/cat/d orally until the onset of estrus (n = 12; MEO); or control (n = 12; CTL). Prepubertal females were randomly assigned to the following three treatments: melatonin 18 mg/cat sc implants at either 1.9 ± 0.3 kg (MEI-A; n = 12) or 1.5 ± 0.3 kg (MEI-B; n = 10) body weight; or control (CTL; n = 10). Interestrus intervals in postpubertal MEI, MEO, and CTL groups were 63.8 ± 5.4, 63.0 ± 5.3 and 19.2 ± 1.4 d (P < 0.05), respectively. In these groups, intervals between onset of treatment and the first estrus cycle were 51.0 ± 4.7, 50.0 ± 6.1, and 12.6 ± 1.1 d (P < 0.05). In the second experiment, neither age (MEI-A: 232.4 ± 10.5, MEI-B: 208.6 ± 13.0 and CTL: 192.4 ± 20.1 d; P > 0.1) nor body weight (P > 0.1) at puberty differed among groups. None of the cats in either study had clinically apparent side effects. We concluded that long-term melatonin treatment of domestic cats slightly prolonged interestrus intervals, but did not postpone puberty.

Kinetic study of the adsorption of nitroimidazole antibiotics on activated carbons in aqueous phase.

The adsorption kinetics of four nitroimidazoles, Dimetridazole (DMZ), Metronidazole (MNZ), Ronidazole (RNZ) and Tinidazole (TNZ), were studied on three activated carbons: two commercial carbons from Sorbo-Norit (S) and Merck (M) and a third prepared by chemical activation of petroleum coke (C). Experimental data of the corresponding adsorption kinetics were analyzed by applying pseudo-first and pseudo-second-order models and a general diffusion model. Application of pseudo-first and pseudo-second-order kinetic models verified the following: (i) The kinetic model used that better predicts the adsorption rates depends of both the adsorbent and adsorbate studied. (ii) Nitroimidazole adsorption rate decreases in the order MNZ>DMZ>RNZ>TNZ; therefore, in the case of MNZ, molecular size does not appear to be a determining factor in the process. (iii) Nitroimidazole adsorption rate on carbons increases in the order C

The GnRH antagonist acyline prevented ovulation, but did not affect ovarian follicular development or gestational corpora lutea in the domestic cat.

Two experiments were conducted to investigate the effects of the GnRH antagonist acyline (330 microg/kg, given sc) on ovarian follicular development and ovulation, as well as on pregnancy maintenance in domestic cats. In the first experiment, seven queens in proestrus (total of 24 proestrus periods), were randomly assigned to treatment with either acyline (ACY; n=17) or a placebo (PLC; n=7). All queens were mated with a fertile tomcat. In the ACY and PLC groups, cessation of estrus occurred (mean+/-SEM) 7.0+/-1.3 and 7.0+/-1.7 d after treatment (P>0.1), ovulation occurred in 2 of 17 and all seven estrus periods (P<0.05), and pregnancy rates were 1 of 16 and 7 of 7 (P<0.05), respectively. In the ACY and PLC groups, intervals from treatment to the onset of the ensuing proestrus were 18.4+/-1.7 and 120+/-17.2 d. In the second experiment, 14 pregnant queens were randomly allocated, according to their mating date, to treatment with acyline in early pregnancy (from 20 to 25 d, n=3), mid pregnancy (from 26 to 45 d; n=4), late pregnancy (> 45 d; n=3), or injection of a placebo in early (n=1), mid (n=2), or late pregnancy (n=1). Ultrasonographic assessments of the uterus were done every second day for 2 wk post treatment, and serum progesterone (P(4)) concentrations were determined before treatment, and at 7 and 14 d after treatment. No pregnancies were prematurely terminated and post-treatment P(4) concentrations did not differ among treatment groups (P>0.1). In conclusion, in the domestic cat, GnRH withdrawal by acyline prevented ovulation when given in early follicular phase (proestrus), but did not significantly affect luteal function during pregnancy.

Effect of a GnRH antagonist on GnRH agonist-implanted anestrous bitches.

Various combinations of gonadotropin-releasing hormone (GnRH) antagonists and long-acting GnRH agonists have been assessed in several species to prevent the "flare-up" effect that agonists cause on the pituitary-gonadal axis. To determine the effect of a single administration of the GnRH antagonist acyline in anestrous GnRH agonist-implanted domestic bitches, 19 dogs (canis familiaris) were randomly assigned to receive either 10mg sc deslorelin acetate (DA; n=6) or DA combined with 330 microg/kg sc acyline within the first 48 h (DA & ACY; n=13). These bitches were examined daily for detection of posttreatment flare-up, manifested as an estrous response during the month after treatment. In the DA and DA&ACY groups, an estrous response was detected in 6 of 6 and 9 of 12 (P<0.5) of the bitches, starting 5.3+/-1.3 and 10.1+/-1.8 d (mean+/-SEM, P=0.5), respectively, after treatment. Based on serum progesterone concentrations, ovulation occurred in 6 of 6 and 5 of 9 of these bitches (P=0.1). None of the dogs had any local or systemic side effects related to the treatments. In five DA and six DA&ACY bitches that could be followed up after the trial, interestrus intervals were 385+/-22.5 and 330+/-69.1 d, respectively (P>0.1). It was concluded that the current antagonist protocol prevented initial ovarian stimulation in one quarter of the treated dogs, whereas the stimulation period was postponed and ovulation was inhibited in approximately half of the remainder.

Effectiveness of different oxidizing agents for removing sodium dodecylbenzenesulphonate in aqueous systems.

The present study investigates the efficacy of various oxidizing treatments (ClO(-), ClO(2), KMnO(4), O(3), O(3)/H(2)O(2), O(3)/activated carbon) to remove from waters sodium dodecylbenzenesulphonate (SDBS), considered as model surfactant. Results obtained show that the use of ClO(-) and ClO(2) does not cause appreciable SDBS degradation. Additionally, in the case of ClO(-), trihalomethanes are generated, increasing system toxicity. Because the reaction kinetics between SDBS and KMnO(4) is very slow, a decrease in contaminant concentration is not observed, even at very acid pH values. SDBS reactivity with ozone is very low, with a kinetic constant (k(O)(3)) of 3.68 M(-1)s(-1), but its reactivity with HO() radicals is very high (k(OH)=1.16 x 10(10)M(-1)s(-1)), therefore O(3)/H(2)O(2) and O(3)/activated carbon, which can also generate HO(), appear as promising advanced oxidation processes to remove this contaminant from waters. The method based on ozone and activated carbon was the only process studied that produced both an increase in SDBS removal rate (due to the generation of HO() radicals in the O(3)-PAC or O(3)-GAC interaction) and a considerable reduction in the concentration of dissolved organic carbon in the system due to the PAC adsorbent properties.

Clinical utility of a combination of tumour markers in the diagnosis of malignant pleural effusions.

BACKGROUND: The aim of the present study was to evaluate the diagnostic value of the tumour markers carcinoembryonic antigen (CEA), carbohydrate antigens CA 125, CA 15.3, CA 19.9 and tumor-associated glycoprotein 72 (TAG 72) in the pleural fluid (PF) of patients with pleural effusions of different etiologies. PATIENTS AND METHODS: One hundred and fifty-five patients with pleural effusions (40 malignant, 84 benign and 31 paraneoplastic) were studied prospectively. The concentration of the tumour markers in serum and PF were measured by magnetic particle enzyme immunoassay. The PF to serum (PF/S) concentration ratios were calculated. RESULTS: The concentrations of CEA, CA 15.3, CA 19.9 and TAG 72 in PF and the PF/serum ratios were significantly higher in effusions of malignant and paraneoplastic origin than in those of benign origin. The receiver operating characteristic (ROC) curves were calculated for each marker and the diagnostic cut-off point was selected as the value that offered a specificity of 100% (CEA: 6.5 ng/ml; CA 15.3:62.4 IU/l; TAG 72:10.9 IU/l). CEA presented the greatest sensitivity [45% in the malignant group, 38.7% in the paraneoplastic group, and 41.4% in the pooled group (combined malignant and paraneoplastic)]. TAG 72 presented the largest area under the curve (0.89 in the malignant group and 0.80 in the pooled group). The diagnostic efficacy of the PF/S ratios was not better than measurement of the tumour markers in pleural fluid. The highest diagnostic accuracy for the diagnosis of malignant pleural effusions was achieved by grouping the markers in a panel comprising CEA, CA 15.3 and TAG 72; this showed a sensitivity of 75% and a negative predictive value of 79.1% . In the subgroup of patients with negative cytology, the sensitivity was 41.2% for CEA, 35.5% for CA 15.3 and 33.3% for TAG 72. The combination of these three markers achieved a sensitivity of 84.6%. CONCLUSION: The combined measurement of CEA, CA 15.3 and TAG 72 in pleural fluid is a useful complementary test in the differential diagnosis of pleural effusions of malignant origin.

Behavior of two different constituents of natural organic matter in the removal of sodium dodecylbenzenesulfonate by O3 and O3-based advanced oxidation processes.

The objective of this study was to analyze the role played by two components of natural organic matter (NOM), gallic acid (GAL) and humic acid (HUM), in the removal of the surfactant sodium dodecylbenzenesulfonate (SDBS) from waters by O(3)-based oxidation processes, i.e., O(3)/H(2)O(2), O(3)/granular activated carbon (GAC), and O(3)/powdered activated carbon (PAC). It was found that the presence of low concentrations of these compounds (1 mg/L) during SDBS ozonation increases both the ozone decomposition rate and the rate of SDBS removal from the medium. Because of the low reactivity of SDBS with ozone, these effects are mainly due to an increase in the transformation rate of ozone into HO(*) radicals. Results obtained demonstrate that the presence of GAL and HUM during SDBS ozonation increases the concentration of O(2)(-*) radicals in the medium, confirming that GAL and HUM act as initiating agents of ozone transformation into HO(*). It was also found that this effect was smaller with a larger molecular size of the acid. Presence of GAL and HUM during SDBS removal by O(3)/H(2)O(2), O(3)/GAC, and O(3)/PAC systems also increases the SDBS degradation rate, confirming the role of these compounds as initiators of ozone transformation into HO(*) radicals.

Adsorption of sodium dodecylbenzenesulfonate on activated carbons: effects of solution chemistry and presence of bacteria.

The objective of the present investigation was to determine the effectiveness of activated carbon in removing sodium dodecylbenzenesulfonate (SDBS) and to analyze the chemical and textural characteristics of the activated carbons that are involved in the adsorption process. Studies were also performed on the influence of operational variables (pH, ionic strength, and presence of microorganisms) and on the kinetics and interactions involved in the adsorption of this pollutant on activated carbon. The kinetics study of SDBS adsorption revealed no problems in its diffusion on any of the activated carbons studied, and Weisz-Prater coefficient (C WP) values were considerably lower than unity for all activated carbons studied. SDBS adsorption isotherms on these activated carbons showed that: (i) adsorption capacity of activated carbons was very high (260-470 mg/g) and increased with larger surface area; and (ii) dispersive interactions between SDBS and carbon surface were largely responsible for the adsorption of this pollutant. SDBS adsorption was not significantly affected by the solution pH, indicating that electrostatic adsorbent-adsorbate interactions do not play an important role in this process. The presence of electrolytes (NaCl) in the medium favors SDBS adsorption, accelerating the process and increasing adsorption capacity. Under the working conditions used, SDBS is not degraded by bacteria; however, the presence of bacteria during the process accelerates and increases SDBS adsorption on the activated carbon. Microorganism adsorption on the activated carbon surface increases its hydrophobicity, explaining the results observed.

Phosphocalcic metabolism after biliopancreatic diversion.

BACKGROUND: Malabsorptive techniques to treat morbid obesity have been followed by alterations in phosphocalcic metabolism. Knowledge of the preoperative situation is important to assess the influence of these techniques on phosphocalcic metabolism and to consider treatments for these alterations. METHODS: 61 consecutive morbidly obese patients (50 women, 11 men, age 19 to 63 years) having had biliopancreatic diversion (BPD) were studied in a prospective manner. Preoperative and postoperative levels of calcium, phosphorus, 25-hydroxyvitamin D, tartrate resistant acid phosphate, plasma parathormone (PTH), tubular absorption of phosphate, and urinary calcium and pyridinolines were analyzed, as well as the potential risk factors for their alterations. Follow-up of all patients was a minimum of 4 years. RESULTS: Before BPD, 42.3% of patients presented an increase in PTH and 54% a decrease in the 25-OH vitamin D, but the values of calcium and plasma phosphorus maintained at normal level. 81.8% of the patients with an increase in the PTH maintained high levels after BPD, while 60% of those with a normal preoperative PTH also presented hyperparathyroidism 4 years after the intervention. A correlation between the levels of plasma PTH and body mass index was not found. CONCLUSION: Morbid obesity is accompanied by a high percentage of hyperparathyroidism. BPD produces malabsorption of vitamin D during the first years, favoring the persistence or appearance of hyperparathyroidism. It is important to recognize and treat the secondary hyperparathyroidism. The postoperative period could necessitate more energetic interventions to get more efficient control of the phosphocalcic metabolism.

Photooxidation of naphthalenesulfonic acids: comparison between processes based on O(3), O(3)/activated carbon and UV/H(2)O(2).

The aim of the present study was to analyze and compare the efficacy of UV photodegradation with that of different advanced oxidation processes (O(3), UV/H(2)O(2), O(3)/activated carbon) in the degradation of naphthalenesulfonic acids from aqueous solution and to investigate the kinetics and the mechanism involved in these processes. Results obtained showed that photodegradation with UV radiation (254 nm) of 1-naphthalenesulfonic, 1,5-naphthalendisulfonic and 1,3,6-naphthalentrisulfonic acids is not effective. Presence of duroquinone and 4-carboxybenzophenone during UV irradiation (308-410 nm) of the naphthalenesulfonic acids increased the photodegradation rate. Addition of H(2)O(2) during irradiation of naphthalenesulfonic acids accelerated their elimination, due to the generation of ()OH radicals in the medium. Comparison between UV photodegradation 254 m and the advanced oxidation processes (O(3), O(3)/activated carbon and UV/H(2)O(2)) showed the low-efficacy of the former in the degradation of these compounds from aqueous medium. Thus, among the systems studied, those based on the use of UV/H(2)O(2) and O(3)/activated carbon were the most effective in the oxidation of these contaminants from the medium. This is because of the high-reactivity of naphthalenesulfonic acids with the *OH radicals generated by these two systems. This was confirmed by the values of the reaction rate constant of *OH radicals with these compounds k(OH), obtained by competitive kinetics (5.7 x 10(9) M(-1) s(-1), 5.2 x 10(9) M(-1) s(-1) and 3.7 x 10(9) M(-1) s(-1) for NS, NDS and NTS, respectively).

[Diagnostic efficacy of fine needle aspiration biopsy in patients with thyroid nodular disease. Analysis of 510 cases]. / Eficacia diagnóstica de la punción-aspiración con aguja fina en pacientes con patología nodular tiroidea. Análisis de 510 casos.

INTRODUCTION: The prevalence of palpable thyroid nodules in the general population is 4%-7%. Although most are benign, 5% are carcinomas. This study aimed to assess the efficacy of fine needle aspiration biopsy (FNAB) of thyroid nodules to diagnose malignancy and know the benefit of repeating the FNAB in the same nodule. PATIENTS AND METHODS: A total of 510 patients (431 women and 79 men; mean age [standard deviation]: 47.6 [14.3] years) with surgery due to thyroid nodular condition between 1989 and 2002 and who had at least one FNAB prior to the surgery were studied. RESULTS: The first FNAB was benign in 312 patients (61.2%), malignant in 38 (7.5%), suspicious or indeterminate in 97 (19%) and insufficient in 63 (12.4%). Sensitivity and specificity in the first FNAB for malignancy diagnosis was 76% and 84%, respectively. Successive FNABs had a moderate concordance and significance. However, repeating the puncture did not improve diagnostic performance, since sensitive increased (84%), but specificity worsened (79%) and the area under the ROC curve was similar. In the group with suspicious or indeterminate FNAB, histology was benign in 70% and malignant in 30%. CONCLUSIONS: FNAB sensitivity and specificity for diagnosis of malignancy in thyroid nodules are high. Repetition of puncture on the same nodule does not improve diagnostic performance of the cytology. Among patients with suspicious FNAB, there is a high proportion of malignancy, which makes surgery necessary in these cases.