Evaluation of the acute and sublethal toxicity of Mancozeb in Pacamã (Lophiosilurus alexandri)

The toxic potential of dithiocarbamates fungicides widely used in world agriculture is well known, among which Mancozeb is one of the most used. This study aimed to evaluate the toxicity of Mancozeb, determining the LC50% of the product and the behavioral and histological changes observed in fish of the Pacamã species through acute and sublethal toxicity tests. The first experiment was carried out on Pacamã fingerlings exposed to dosages of 0.5, 1, 2, 4, and 8mg/L of Mancozeb under the form ManzateWG®, for a total period of 96 hours in the acute experiment, and in the second experiment, fish were subjected to concentrations of 1/10 of those used in the acute experiment (0.05, 0.1, 0.2, 0.4 and 0.8mg/L, respectively), for 15 days in total. The 50% lethal concentration of ManzateWG® was calculated at the end of the acute experiment, presenting a value of 2.29mg/L at 96h for Pacamã fingerlings. A behavioral assessment was carried out through daily observation of the fish during both experiments, and an increase in mucus production was observed, as well as atypical social behavior in those exposed to the toxic agent. Histopathological evaluation was performed on livers collected after the end of the sublethal experiment, and the main hepatic alterations observed were cytoplasmic vacuolization, inflammatory infiltrate, and necrosis. Mancozeb has toxic potential and is capable of generating behavioral changes, as well as increasing the risk of liver damage in Pacamãs exposed to this compound.

Abstract P3-04-01: The value of stereotactic vacuum-assisted biopsy in the investigation of microcalcifications in 1354 patients in public Brazilian hospital

Background: The gold standard for breast biopsy procedures is currently an open excision of the suspected lesion. However, an excisional biopsy inevitably makes a scar. The cost and morbidity associated with this procedure has prompted many physicians to evaluate less invasive, alternative procedures. More recently, image-guided percutaneous core-needle biopsy has become a frequently used method for diagnosing palpable and non-palpable breast lesions. Although sensitivity rates for core-needle biopsy are high, it has the disadvantage of histological underestimation, which renders the management of atypical ductal hyperplasia, papillary lesions, and fibroepithelial lesions somewhat difficult. Stereotactic vacuum assisted breast biopsy (VABB) was developed to overcome some of these negative aspects of core-needle biopsy. VABB allows for a sufficient specimen to be obtained with a single insertion and can provide a more accurate diagnosis and completely remove the lesion under real-time ultrasonic guidance. The advantage of complete lesion removal with VABB is to reduce or eliminate sampling error, to decrease the likelihood of a histological underestimation, to decrease imaging-histological discordance, to decrease the re-biopsy rate, and to diminish the likelihood of subsequent growth on follow-up, especially when stereotactic VABB is used to investigate microcalcifications. This method is expensive but cost effective when used to investigate microcalcifications classified as BI-RADS 4 and 5.

Methodology: We performed a review in 1,354 patients with suspicious mammography microcalcifications, classified as BI-RADS 4 or 5 that were seen in Perola Byington Hospital from July 2012 to July 2017 in São Paulo-Brazil. We have used aHologic Lorad Multicare Platinum Stereotactic Prone Breast Biopsy and a Surus Pearl (Hologic, Malbolrough, Massachusetts, USA), with gauge 9 probe. Four to eight fragments (median of 6) were obtained with the placement of a metal clip in the bed that the biopsy was performed, and histopathological analysis was made.

Results:The histopathological study of the lesions revealed benign alterations in 956 (68%) of our patients. The findings were positive for malignancy in 358 patients (29%) and the precursor lesions were diagnosed in 40 (3%). In 81 cases (5.9%) the findings were discordant. The sensitivity of the method was 84.4%, specificity was 96.1%, false negative rate was 4.5%, positive predictive value (PPV) was 89.8%, negative predictive value (NPV) was 93.8%. In literature review the sensitivity varies 91.5-100%, specificity 81.9-110%, false negative rate 0-3.3%, PPV 92.2-100% and NPV 80.5-99.5%. All patients with positive or discordant cases underwent surgical treatment to increase the margin or complete removal of the lesion. Conclusions: The VABB is an outpatient procedure that avoids hospital admissions for diagnostic elucidation in most of cases suspected of malignancy. It has high predictive value in both benign and malignant lesions, guiding therapeutic planning. In addition to presenting the cost lower than the surgical biopsy it indirect increases the supply of hospital beds for cancer treatment.

Citation Format: Mattar A, Amorim AG, Ramos MdNM, Shida JY, Fonseca GR, Hegg R, Gebrim LH. The value of stereotactic vacuum-assisted biopsy in the investigation of microcalcifications in 1354 patients in public Brazilian hospital [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-04-01.

Orthotopic liver transplantation without venovenous bypass: 125 cases from a single center

AIM

This study analyzed a 10-year single-center experience in orthotopic liver transplantation (OLT) without venovenous bypass (VVB).

METHODS

We retrospectively analysed a nonrandomized series (1999-2008) of 125 adult OLT patients without VVB.

RESULTS

The main causes of liver failure were viral hepatitis (n = 39), alcoholic liver disease (n = 22), and liver cancer (n = 17). One-year survival was 76.4%. The most common postoperative complications were bile duct stenosis (n = 12), postoperative bleeding (n = 8), hepatic artery thrombosis (n = 7), and primary liver failure (n = 6). Twelve patients required hemodialysis and four underwent retransplantations of the liver. Fourteen patients died before postoperative day 30(th). Univariate analysis showed significant differences between patients who did and did not survive 30 days among donor death diagnoses (P = .05), red blood cell units transfused (P = .03), aspartate aminotranferase on the first postoperative day (P = .002), ABO type (P = .04), time of orotracheal intubation (P = .001), hemodialysis (P = .001), and period of postoperative vasoactive drug use (P = .006). The total length of orotracheal tube intubation showed a significant independent association with mortality before 30 days (P < .001).

CONCLUSION

OLT without VVB can be safely performed even in severe cases of chronic liver failure.

Orthotopic liver transplantation without venovenous bypass using the conventional and piggyback techniques

INTRODUCTION

Orthotopic liver transplantation is a widely used procedure for the treatment of irreversible liver diseases for which there is no possibility of medical treatment. When this procedure is performed by the conventional technique, the retrohepatic vena cava is removed along with the native liver. The inferior vena cava (IVC) remains clamped until the revascularization of the graft, and in this period there is a reduction in the venous return, which may induce a fall by up to 50% in the cardiac output with hemodynamic instability and a fall in renal perfusion pressure. The use of a portal-femoral-axillary venovenous bypass system, in which the blood from the femoral and portal veins returns to the heart via the axillary vein propelled by a centrifugal pump, is intended to minimize the effects of the IVC clamping. In the piggyback (PB) technique, the native liver is removed and the IVC of the recipient is preserved and only partially clamped. We have employed both techniques without the use of venovenous bypass for 10 years. The objective of this study was to compare the results obtained from the use of the two techniques.

PATIENTS AND METHODS

A retrospective analysis was performed of 195 patients transplanted between 1999 and 2008: 125 by the conventional technique and 70, the PB technique. The intraoperative parameters were analyzed (surgical time, ischemia time, use of blood products, and diuresis), as well as intensive care support (duration of stay in intensive care unit and use of vasoactive drugs), period of intubation, length of hospital stay, renal function, graft function, postoperative complications, retransplantation, and patient survival.

RESULTS

The PB group showed a reduction in surgical time, warm ischemia time, the use of packed red blood cells concentrates, and fresh frozen plasma, as well as mortality at 30 days (P<.05). There were no differences in relation to cold ischemia time, intraoperative diuresis; length of stay and use of vasoactive drugs in the intensive care unit; the period of intubation; the duration of hospital stay; the renal function; the graft function; the need for reoperation; the incidence of sepsis, biliary complications, vascular complications; need for retransplantation; and 1-year mortality. The cumulative survival rate at 1 year was significantly better among the PB patients.

CONCLUSION

Orthotopic liver transplantation can be performed without venovenous bypass with good results, using either the conventional technique or the PB technique. Provided that there is no technical contraindication and a long ischemia period is not foreseen, the PB technique should be the technique of choice.

Identification of the C-terminal region of 70 kDa heat shock protein from Leishmania (Viannia) braziliensis as a target for the humoral immune response

A Leishmania (Viannia) braziliensis (Lb) promastigote cDNA library in lambda gt11 was screened with patients' sera with the aim of identifying antigens specifically related to mucocutaneous leishmaniasis (MCL). One of the clones isolated, 133P, consistently reacted with MCL sera; it was sequenced and found to encode the C-terminal three-quarters of a protein belonging to the highly conserved Hsp70 family. Since Hsp70 proteins from different species tend to be less conserved through the C-terminal end, it was predicted that this region would be more antigenic and was likely to bear the discriminatory epitopes. In order to test this hypothesis, the N- and C-terminal halves of the polypeptide encoded by 133P, 133P-N and 133P-C, respectively, were expressed in Escherichia coli. Immunoblotting analysis demonstrated that 133P-C reacted more strongly with a pool of MCL sera than 133P-N, and both recombinant proteins reacted faintly with pools of cutaneous (CL) and visceral (VL) leishmaniasis sera. These results confirmed the predicted epitope location in the C-terminal region. The 133P-C fragment was also expressed as a fusion protein with glutathione-S-transferase (GST-133P-C), affinity-purified with glutathione-agarose and tested by ELISA with individual sera. From 46 Lb-infected patients, 41 sera (89%) were positive, no cross-reactivity was observed with healthy, Trypanosoma cruzior L. amazonensis-infected individuals. Despite a relatively high cross-reactivity with VL sera, the enhanced humoral response of MCL as compared with CL patients might be interesting for studies on disease aggravation.

Expression of Mycobacterium leprae 18-kDa antigen in yeast in a GPI-anchored form

The 18-kDa protein from Mycobacterium leprae is a major target for the immune response in leprosy. We have developed a system to express this antigen in yeast as a fusion protein with the C-terminal region of the yeast membrane protein GAS1, which would render the recombinant protein anchored to the plasma membrane by a glycosylphosphatidylinositol (GPI) anchor. Cells lacking the GAS1 gene and transformed with the hybrid 18-kDa-GAS1 construct express a polypeptide that reacts with an 18-kDa-specific monoclonal antibody. In addition, these cells react with an alpha-CRD antibody after GPI-PLC treatment. The non-transformed cells are negative. These data indicate that our system may be suitable for the expression of foreign proteins in yeast in a GPI-anchored form.