Histoplasmin and paracoccidioidin skin reactivity in infantile population of Northern Argentina

In order to estimate ages at which etiological agents of systemic mycoses initiate infection, histoplasmin and paracoccidioidin skin tests were performed in 344 children of both sexes, between 2 and 15 years old. They were selected from a statistically significant population sample Gral. San Martín city (Northeast Argentina). Tests were read 48h after injection and considered positive if a 5 mm on larger induration was present. Circulating antibodies were also evaluated by agar gel immunodiffusion. The overall infection rate for H. capsulatum was 9.2%, belonging to children from 4 to 14 years old, without significant differences among sexes. Five children from 2 to 14 years old were positive to paracoccidioidin (1.6%). None of the children had specific antibodies neither signs of active mycosis. Results show H. capsulatum infection can be found from age 4, while for P. brasiliensis the lower limit was two years old. These findings may contribute to better knowledge on infantile fungal infection in a geographical region where no previous references can be found.

Toxocara seroprevalence in children from a subtropical city in Argentina

Most studies from Argentina have focused on toxocariasis as an environmental problem of big cities, and there are no available data about children infection from small or middle-sized cities. In order to assess the prevalence of anti-Toxocara antibodies in infantile population, 206 children from Resistencia, of both sexes, aged 1-14 years old were studied by Elisa testing with E/S T. canis L2 antigens. Hematological parameters and immunoglobulin levels were determined; five days' stool samples were studied and epidemiological data were obtained by means of a questionnaire to parents. Results showed that 73% of the children had one or more dogs living at home, 57% reported geophagia and 37.9% were positive for Toxocara serology, but there was no significant difference in prevalence neither for boys and girls, nor concerning age. An increased risk of infection was observed in age groups 5-6 and 7-8 for boys, and in age groups 3-4 and 5-6 for girls.

Human papillomavirus genotypes in women with cervical cytological abnormalities from an area with high incidence of cervical cancer

It has been well demonstrated the relationship between the infection with high-risk human papillomavirus (HPVs) genotypes and cervical cancer. In Northeastern Argentina a high incidence of this pathology has been described and therefore a high prevalence of HPV infection is expected. In order to identify HPV genotypes associated with malignant and pre-malignant cervical lesions present in the area, 53 ecto-endo cervical cell specimens obtained from women with cytohistological alterations were studied by a PCR-RFLP technique. Out of 53 patients, 34 (64.2%) were positive for HPV infection, being HPV-16 (32.3%) the most frequently found genotype, followed by HPV-58 (14.7%), -6, -18 and -45 (5.9%), -33, -52, -53, -54, -56, -66, -MM4 and -LVX100 (2.9%). Also 5 cases of infection caused by multiple genotypes were found, which corresponded to 14.7% of the positive cases. Results indicate that besides HPV-16 and -18, the most prevalent high-risk HPV genotypes worldwide, others like -45 and -58 as well as co-infection cases are frequent between women of Northeastern Argentina, and a particular attention should be paid to this circumstance because it could be an epidemiological feature of regional importance and a useful information for a future vaccination program.

Partial characterization of proteolytic activity in Giardia duodenalis purified proteins

This report describes a preliminary characterization of proteolytic activity of proteins isolated from lysate of Giardia trophozoites of an axenic Brazilian strain. Fractions obtained by high-performance liquid chromatography (FPLC) were tested in SDS-polyacrylamide gel for the protein profiles, and the proteases activity was analyzed using gelatin impregnated SDS-PAGE. The proteases characterization was based on inhibition assays employing synthetic inhibitors for cysteine (E-64, IAA), serine (PMSF, TPCK, TLCK, and elastatinal), metalo (EDTA) and aspartic (pepstatin) proteases. Among thirty eluted fractions, polypeptide bands were observed in eight of them, however, proteolytic activity was detected in four ones (F23, F24, F25 and F26). Protein profiles of these fractions showed a banding pattern composed by few bands distributed in the migration region of 45 to < 18 kDa. The zymograms revealed proteolytic activity in all the four fractions assayed, mainly distributed in the migration region of 62 to 35 kDa. Among the profiles, the main pronounced zones of proteolysis were distinguished at 62, 55, 53, 50, 46 and 40 kDa. In inhibition assays, the protease activities were significantly inhibited by cysteine (E-64) and serine proteases (TPCK, TLCK and elastatinal) inhibitors. Gels incubated with other cysteine and serine protease inhibitors, IAA and PMSF, respectively, showed a decrease in the intensity of hydrolysis zones. Indeed, in the assays with the inhibitors EDTA for metalloproteases and pepstatin for aspartic proteases, none inhibition was detected against the substrate. These observations are relevants, especially if we consider that to define the real role of the proteases in host-parasite interaction, the purification of these enzymes for detailed studies may be warranted.

ASSESSMENT OF THE PRESENCE OF Toxocara EGGS IN SOILS OF AN ARID AREA IN CENTRAL-WESTERN ARGENTINA

With the aim of studying the contamination of soils with eggs of Toxocara spp. in an arid area in the central-western region of Argentina, 76 soil samples were collected from 18 towns belonging to six provinces of central-western Argentina. They were processed by the centrifugal flotation method. No eggs of Toxocara spp. were found. It can be concluded that the negative results are directly related to the characteristics of the environment and climate present in the studied area. The finding of eggs in soils depends on several factors: the presence of canine or feline feces, the hygienic behavior of pet owners, the presence of stray animals without veterinary supervision, the weather and environmental conditions, and laboratory techniques used; and all these circumstances must be considered when comparing the results found in different geographical regions. In order to accurately define the importance of public spaces in the transmission of infection to humans, it is important to consider the role of backyards or green spaces around housing in small towns, where the population is not used to walking pets in public spaces, and in such cases a significant fraction of the population may acquire the infection within households.

Exame parasitológico de fezes de gatos (Felis catus domesticus) domiciliados e errantes da Região Metropolitana do Rio de Janeiro, Brasil

Foram estudadas 131 amostras de fezes de gatos de comportamento domiciliado e errante da Região Metropolitana do Rio de Janeiro, obtendo-se uma positividade de 63,4% das amostras, com maior ocorrência no grupo de animais errantes. Foi observado predomínio de parasitismo por Ancylostoma sp (43,5%), Toxocara sp (19,1%) e Cystoisospora sp (43,5%) em ambos os grupos. Também foram encontrados ovos de Uncinaria sp (1,5%), Toxascaris leonina (7,6%), cistos de Giardia sp (6,1%) e esporocistos de Sarcocystis sp (0,8%). A alta prevalência de enteroparasitas na amostra estudada ressalta a importância de um maior controle parasitológico nesses animais, para proteção da saúde animal e humana.

Impacto ambiental de modificações ecológicas realizadas em uma área subtropical

No período de 1994 a 2000, durante a construção e enchimento da represa Yacyretá, foram estudadas em Ituzaingó e Posadas variáveis infecciosas (diarréias e infecções respiratórias), clínico-cirúrgicas (doenças cardiovasculares e politraumatismos) e ambientais (pluviais, temperatura e umidade). As diarréias, em Ituzaingó, tiveram um aumento 6,5%, 78,3% e 13%, respectivamente em 1995, 1996 e 1997 e nos anos seguintes os valores foram similares aos de 1994 e em Posadas mostraram uma tendência ascendente. As infecções respiratórias, em Ituzaingó em 1995, aumentaram 143% e nos períodos subseqüentes voltaram aos limites de 1994 e, em Posadas tiveram valores ascendentes. No Hospital de Ituzaingó, em 1995, as doenças incrementaram 97,6%, mostraram decréscimo em 1996 e atingiram 127% em 2000; os politraumatismos aumentaram 107% em 1995, declinaram 38% em 1996 nos anos seguintes apresentaram tendência ascendente atingindo 33% em 2000. O impacto das variáveis ambientais foi maior em Ituzaingó do que em Posadas. O aumento das doenças relacionou-se com a temperatura máxima, mas não com a umidade.

Genes that encodes NAGT, MIF1 and MIF2 are not virulence factors for kala-azar caused by Leishmania infantum

IntroductionKala-azar is a disease resulting from infection by Leishmania donovani and Leishmania infantum. Most patients with the disease exhibit prolonged fever, wasting, anemia and hepatosplenomegaly without complications. However, some patients develop severe disease with hemorrhagic manifestations, bacterial infections, jaundice, and edema dyspnea, among other symptoms, followed by death. Among the parasite molecules that might influence the disease severity are the macrophage migration inhibitory factor-like proteins (MIF1 and MIF2) and N-acetylglucosamine-1-phosphotransferase (NAGT), which act in the first step of protein N-glycosylation. This study aimed to determine whether MIF1, MIF2 and NAGT are virulence factors for severe kala-azar.MethodsTo determine the parasite genotype in kala-azar patients from Northeastern Brazil, we sequenced the NAGT genes of L. infantum from 68 patients as well as the MIF1 and MIF2 genes from 76 different subjects with diverse clinical manifestations. After polymerase chain reaction (PCR), the fragments were sequenced, followed by polymorphism identification.ResultsThe nucleotide sequencing of the 144 amplicons revealed the absence of genetic variability of the NAGT, MIF1 and MIF2 genes between the isolates. The conservation of these genes suggests that the clinical variability of kala-azar does not depend upon these genes. Additionally, this conservation suggests that these genes may be critical for parasite survival.ConclusionsNAGT, MIF1 and MIF2 do not alter the severity of kala-azar. NAGT, MIF1 and MIF2 are highly conserved among different isolates of identical species and exhibit potential for use in phylogenetic inferences or molecular diagnosis.

Bowel preparation for colonoscopy: comparison of mannitol and sodium phosphate. Results of a prospective randomized study

METHOD: Eighty patients were prospectively randomized for precolonoscopic cleansing either with 750 ml of 10% mannitol (Group M) or 180 ml of a sodium phosphate preparation (Group NaP). Laboratory examinations before and after preparation on all patients included hemoglobin, hematocrit, sodium, potassium, phosphorous, calcium and serum osmolarity. A questionnaire was used to assess undesirable side effects and patient tolerance to the solution. The quality of preparation was assessed by the endoscopist who was unaware of the solution employed. RESULTS: Statistically significant changes were verified in serum sodium, phosphorous, potassium and calcium between the two groups, but no clinical symptoms were observed. There were no significant differences in the frequency of side effects studied. Six of the eight patients in Group NaP who had taken mannitol for a previous colonoscopy claimed better acceptance of the sodium phosphate solution. The endoscopic-blinded trial reported excellent or good bowel preparation in 85% prepared with sodium phosphate versus 82.5% for mannitol (p=0.37). CONCLUSIONS: Quality of preparation and frequency of side effects was similar in the two solutions. The smaller volume of sodium phosphate necessary for preparation seems to be related to its favorable acceptance. Nevertheless, the retention of sodium and phosphate ions contraindicates the use of sodium phosphate in patients with renal failure, cirrhosis, ascites, and heart failure.

Colorectal cancer screening

Colorectal cancer (CRC) is the third most common cancer in the world, and mortality has remained the same for the past 50 years, despite advances in diagnosis and treatment. Because significant numbers of patients present with advanced or incurable stages, patients with pre-malignant lesions (adenomatous polyps) that occur as result of genetic inheritance or age should be screened, and patients with long-standing inflammatory bowel disease should undergo surveillance. There are different risk groups for CRC, as well as different screening strategies. It remains to be determined which screening protocol is the most cost-effective for each risk catagory. The objective of screening is to reduce morbidity and mortality in a target population. The purpose of this review is to analyze the results of the published CRC screening studies, with regard to the measured reduction of morbidity and mortality, due to CRC in the studied populations, following various screening procedures. The main screening techniques, used in combination or alone, include fecal occult blood tests, flexible sigmoidoscopy, and colonoscopy. Evidence from the published literature on screening methods for specific risk groups is scanty and frequently does not arise from controlled studies. Nevertheless, data from these studies, combined with recent advances in molecular genetics, certainly lead the way to greater efficacy and lower cost of CRC screening.

Role of colonoscopy in colorectal cancer

Colorectal cancer (CRC) represents the third most common malignancy throughout the world. Little or no improvement in survival has been effectively achieved in the last 50 years. Extensive epidemiological and genetic data are able to identify more precisely definite risk-groups so screening and early diagnosis can be more frequently accomplished. CRC is best detected by colonoscopy, which allows sampling for histologic diagnosis. Colonoscopy is the gold standard for detection of small and premalignant lesions, although it is not cost-effective for screening average-risk population. Colonoscopic polypectomy and mucosal resection constitute curative treatment for selective cases of invasive CRC. Similarly, alternative trans-colonoscopic treatment can be offered for adequate palliation, thus avoiding surgery.

Conventional approach x laparoscopic abdominoperineal resection for rectal cancer treatment after neoadjuvant chemoradiation: results of a prospective randomized trial

OBJECTIVE: The aims of this study were to evaluate the safety and efficacy of laparoscopic abdominoperineal resection compared to conventional approach for surgical treatment of patients with distal rectal cancer presenting with incomplete response after chemoradiation. METHOD: Twenty eight patients with distal rectal adenocarcinoma were randomized to undergo surgical treatment by laparoscopic abdominoperineal resection or conventional approach and evaluated prospectively. Thirteen underwent laparoscopic abdominoperineal resection and 15 conventional approach. RESULTS: There was no significant difference (p<0,05) between the two studied groups regarding: gender, age, body mass index, patients with previous abdominal surgeries, intra and post operative complications, need for blood transfusion, hospital stay after surgery, length of resected segment and pathological staging. Mean operation time was 228 minutes for the laparoscopic abdominoperineal resection versus 284 minutes for the conventional approach (p=0.04). Mean anesthesia duration was shorter (p=0.03) for laparoscopic abdominoperineal resection when compared to conventional approach : 304 and 362 minutes, respectively. There was no need for conversion to open approach in this series. After a mean follow-up of 47.2 months and with the exclusion of two patients in the conventional abdominoperineal resection who presented with unsuspected synchronic metastasis during surgery, local recurrence was observed in two patients in the conventional group and in none in the laparoscopic group. CONCLUSIONS: We conclude that laparoscopic abdominoperineal resection is feasible, similar to conventional approach concerning surgery duration, intra operative morbidity, blood requirements and post operative morbidity. Larger number of cases and an extended follow-up are required to adequate evaluation of oncological results for patients undergoing laparoscopic abdominoperineal resection after chemoradiation for radical treatment of distal rectal cancer.

Anorectal leiomyomas: report of two cases with different anatomical patterns and literature review

Gastrointestinal mesenchymal tumors comprise a rare group of gastrointestinal tract wall tumors that have long been a source of confusion and controversy, especially in terms of pathological classification, preoperative diagnosis, management strategies, and prognosis. This report describes the clinical manifestations and management of 2 rectal leiomyomas and reviews the pertinent literature. Case 1: A 44-year-old woman was admitted reporting a nodule in the right para-anal region for the previous 2 years. At proctological examination, a 4-cm diameter fibrous mass situated in the para-anal region that produced an arch under the smooth muscle on the right rectal wall just above the anorectal ring was noted. Computed tomography and magnetic resonance imaging of the abdomen and pelvis showed the lesion and detected no other abnormalities. Surgical treatment consisted of wide local resection of the tumor through a para-anal incision, with no attempts to perform lymphadenectomy. Case 2: A 40-year-old male patient was admitted reporting constant anal pain for 4 months. He presented a 3-cm submucosal nodule at the anterior rectal wall just above the dentate line. After 2 inconclusive preoperative biopsies, transanal resection of the tumor was performed. Histological analysis of the specimen showed a benign leiomyoma. A review of the literature is presented, emphasizing some clinical and therapeutic aspects of this unusual rectal tumor.

Cross-scale determinants of palm species distribution

We investigate palm species distribution, richness and abundance along the Mokoti, a seasonally-dry river of southeastern Amazon and compare it to the patterns observed at a large scale, comprising the entire Brazilian territory. A total of 694 palms belonging to 10 species were sampled at the Mokoti River basin. Although the species showed diverse distribution patterns, we found that local palm abundance, richness and tree basal area were significantly higher from the hills to the bottomlands of the study region, revealing a positive association of these measures with moisture. The analyses at the larger spatial scale also showed a strong influence of vapor pressure (a measure of moisture content of the air, in turn modulated by temperature) and seasonality in temperature: the richest regions were those where temperature and humidity were simultaneously high, and which also presented a lower degree of seasonality in temperature. These results indicate that the distribution of palms seems to be strongly associated with climatic variables, supporting the idea that, by 'putting all the eggs in one basket' (a consequence of survival depending on the preservation of a single irreplaceable bud), palms have become vulnerable to extreme environmental conditions. Hence, their distribution is concentrated in those tropical and sub-tropical regions with constant conditions of (mild to high) temperature and moisture all year round.

Fatores de risco que favorecem a recaída no alcoolismo

OBJETIVO: Existe uma prevalência estimada de 11,2% de alcoolismo no Brasil. As tentativas de muitos alcoolistas para abandonar o consumo resultam fracassos e recaídas. A freqüência de recaída, segundo estudos, oscila entre 10% e 30%, assinalando-se diferentes causas. O objetivo da presente pesquisa é conhecer os fatores que favorecem as recaídas. MÉTODOS: Aplicaram-se entrevistas e questionários "Fatores de Recaída" e "Razões para Beber" a 105 alcoolistas primários de ambos os sexos, e com predomínio de alcoolismo puro. RESULTADOS: Os principais fatores de recaída são a pressão social, os conflitos interpessoais, os estados emocionais negativos, assim como a própria dependência fisiológica e psicológica. CONCLUSÕES: De maneira geral, os sujeitos apresentaram grande quantidade de fatores e razões que atuam simultaneamente favorecendo a recaída.