O-naphthoquinone isolated from Capraria biflora L. induces selective cytotoxicity in tumor cell lines.

Biflorin is an o-naphthoquinone isolated from the roots of the plant Capraria biflora L. (Scrophulariaceae). In this study, the cytotoxic effects of biflorin were verified, and late apoptosis was detected in various cancer cell lines by in situ analysis. The cytotoxicity was further evaluated exclusively for 48 h of treatment in different tumor and non-tumor cell lines (Hep-2, HeLa, HT-29, A-375, and A-549, and HEK-293, respectively). The results indicated that biflorin induced selective cytotoxicity in tumor cells. HeLa cells were more susceptible to biflorin, followed by HT-29, A-549, A-375, and Hep-2 at all concentrations (range 5-50 µg/mL), and the highest half-maximal inhibitory concentration IC50 (56.01 ± 1.17 µg/mL) was observed in HEK-293 cells. Late apoptotic/necrotic events, observed by in situ immunostaining with Annexin V, varied with each cell line; an increase in late apoptotic events was observed corresponding to the increase in biflorin dosage. Hep-2 cells showed a greater percentage of late apoptotic events among the tumor cell lines when treated with higher concentrations of biflorin (69.63 ± 2.28%). The non-tumor HEK-293 line showed greater resistance to late apoptotic events, as well as a lower level of cytotoxicity (77.69 ± 6.68%) than the tested tumor lines. The data presented indicate that biflorin showed an important, possibly selective, cytotoxicity against tumor cell lines, thereby revealing a promising novel substance with potential anticancer activity for tumor therapy.

Surgical approach and radioactive iodine therapy for small well-differentiated thyroid cancer.

BACKGROUND: Management of small well-differentiated thyroid cancer (DTC) has generated much debate regarding the surgical approach and radioactive iodine treatment (RAI). AIM: The aim of the study was to evaluate the impact of surgical extension and RAI on the outcome of DTC ≤2 cm. METHODS: A retrospective analysis of 176 cases of DTC ≤2 cm was performed. RESULTS: At diagnosis, tumor size was 1.38 ± 0.55 cm, age 40.2 ± 13.6 years. After a mean follow-up period of 14.1 ± 4.5 years, 15.9 % patients had recurrent/persistent structural disease, with cervical neck disease (thyroid gland area and/or cervical lymph nodes) in 11.9 % cases and distant metastasis in 5.1 %. Disease specific mortality was of 1.1 %. No difference in outcome was observed between patients submitted to total or subtotal thyroidectomy. After total and subtotal thyroidectomy, the rate of recurrent/persistent structural disease was 19.1 and 10.6 % (p = 1.00), respectively. Using the multivariate cox proportion hazards analysis, no difference in the clinical outcome was observed after total or subtotal thyroidectomy (p = 0.703) neither after RAI (p = 0.807). Similar results were observed after stratification by tumor size. Multifocal disease (p = 0.007), extra-thyroid extension (p = 0.007) and presence of lymph node metastasis (p = 0.000) were associated with unfavorable outcome. CONCLUSIONS: Total thyroidectomy and RAI did not improve clinical outcomes of DTC ≤2.0 cm when compared with less extensive surgery and no RAI in selected patients. Therefore, in carefully selected patients with DTC ≤2.0 cm and no unfavorable risk factors (multifocal disease, extra-thyroid extension, lymph node and/or distant metastasis), less extensive surgery and no RAI may be acceptable treatment options.

Monitoring and treatment of anti-D in pregnancy.

Prophylactic anti-D is a very safe and effective therapy for the suppression of anti-D immunization and thus prevention of haemolytic disease of the foetus and newborn. However, migration from countries with low health standards and substantial cuts in public health expenses have increased the incidence of anti-D immunization in many "developed" countries. Therefore, this forum focuses on prenatal monitoring standards and treatment strategies in pregnancies with anti-D alloimmunization. The following questions were addressed, and a response was obtained from 12 centres, mainly from Europe.

Structure-mutagenicity relationship of kaurenoic acid from Xylopia sericeae (Annonaceae).

Kaurane diterpenes are considered important compounds in the development of new highly effective anticancer chemotherapeutic agents. Genotoxic effects of anticancer drugs in non-tumour cells are of special significance due to the possibility that they induce secondary tumours in cancer patients. In this context, we evaluated the genotoxic and mutagenic potential of the natural diterpenoid kaurenoic acid (KA), i.e. (-)-kaur-16-en-19-oic acid, isolated from Xylopia sericeae St. Hill, using several standard in vitro and in vivo protocols (comet, chromosomal aberration, micronucleus and Saccharomyces cerevisiae assays). Also, an analysis of structure-activity relationships was performed with two natural diterpenoid compounds, 14-hydroxy-kaurane (1) and xylopic acid (2), isolated from X. sericeae, and three semi-synthetic derivatives of KA (3-5). In addition, considering the importance of the exocyclic double bond (C16) moiety as an active pharmacophore of KA cytotoxicity, we also evaluated the hydrogenated derivative of KA, (-)-kauran-19-oic acid (KAH), to determine the role of the exocyclic bond (C16) in the genotoxic activity of KA. In summary, the present study shows that KA is genotoxic and mutagenic in human peripheral blood leukocytes (PBLs), yeast (S. cerevisiae) and mice (bone marrow, liver and kidney) probably due to the generation of DNA double-strand breaks (DSB) and/or inhibition of topoisomerase I. Unlike KA, compounds 1-5 and KAH are completely devoid of genotoxic and mutagenic effects under the experimental conditions used in this study, suggesting that the exocyclic double bond (C16) moiety may be the active pharmacophore of the genetic toxicity of KA.

Antiproliferative and photoprotective activities of the extracts and compounds from Calea fruticosa.

In this paper, we complement our previous study on the antiproliferative activity of Calea fruticosa (Asteraceae) by isolating the compounds apigenin-4',7-dimethyl ether (1), budlein A (2), quercetin (3), and cichoriin (4) from the plant's aerial parts. The antiproliferative activity of these compounds was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method against human tumor cell lines. Compound 3 displayed moderate antiproliferative activity in three cell lines (HCT-116, PC-3, and SF-295, with cell growth inhibition values of 72.97, 74.55, and 68.94%) and high antiproliferative activity (90.86%) in the HL-60 cell line. The in vitro sun protection factor (SPF) of the extracts and compound 4, with and without sunscreen, was determined by a spectrophotometric method. The ethanol extract exhibited the highest SPF (9.67) at a concentration of 0.100 mg/mL, while compound 4, isolated from this extract, showed a SPF of 13.79 at the same concentration. A relative increased efficacy of SPF was observed for the extracts and compound 4 when sunscreen was also used. Compound 4 has not been reported previously from any species within the genus Calea. Compounds 1-4 were obtained from this species for the first time.

Cell cycle arrest induced by pisosterol in HL60 cells with gene amplification.

The leukemia cell line HL60 is widely used in studies of the cell cycle, apoptosis, and adhesion mechanisms in cancer cells. We conducted a focused cytogenetic study in an HL60 cell line, by analyzing GTG-banded chromosomes before and after treatment with pisosterol (at 0.5, 1.0, and 1.8 microg/ml), a triterpene isolated from Pisolithus tinctorius, a fungus collected in the Northeast of Brazil. Before treatment, 99% of the cells showed the homogeneously staining region (HSR) 8q24 aberration. After treatment with 1.8 microg/ml pisosterol, 90% of the analyzed cells lacked this aberration. We further performed a pulse test, in which the cells treated with pisosterol (0.5, 1.0, and 1.8 microg/ml) were washed and re-incubated in the absence of pisosterol. Only 30% of the analyzed cells lacked the HSR 8q24 aberration, suggesting that pisosterol probably blocks the cells with HSRs at interphase. No effects were detected at lower concentrations. At the highest concentration examined (1.8 microg/ml), pisosterol also inhibited cell growth, but this effect was not observed in the pulse test, reinforcing our hypothesis that, at the concentrations tested, pisosterol probably does not induce cell death in the HL60 line. The results found for pisosterol were compared with those for doxorubicin. Cells that do not show a high degree of gene amplification (HSRs and double-minute chromosomes) have a less aggressive and invasive behavior and are easy targets for chemotherapy. Therefore, further studies are needed to examine the use of pisosterol in combination with conventional anti-cancer therapy.

Effect of intravitreal dexamethasone solution on the reduction of macular thickness in pseudophakic diabetic patients in a public hospital in Brazil: a randomized clinical trial.

PURPOSE: To determine the effect of short-term 4 mg/mL dexamethasone solution treatment in diabetic macular edema (DME). PATIENTS AND METHODS: Twenty-seven pseudophakic diabetic patients with visual impairment caused by DME were randomized to receive 0.01 mL (40 µg), 0.03 mL (120 µg) or 0.05 mL (200 µg) intravitreal dexamethasone solution. Eyes were evaluated in terms of macular thickness, best-corrected visual acuity (BCVA) and intraocular pressure (IOP) at 3, 7 and 28 days after injection (D). RESULTS: There was a significant reduction in macular thickness between D0 and D3 for all groups (0.01 mL - P=0.008, 0.03 mL - P=0.038, and 0.05 mL - P=0.008). Between D0 and D7, a significant reduction in macular thickness was observed in 0.01 mL and 0.05 mL groups (0.01 mL - P=0.013 and 0.05 mL - P=0.021). Between D0 and D28, no significant reduction of macular thickness was observed for any group. Between D0 and D3, a significant improvement in BCVA in the 0.03 mL group (P=0.028) was observed. Between D0 and D7, a significant improvement in BCVA was observed in 0.01 mL and 0.03 mL groups (0.01 mL - P=0.018 and 0.03 mL - P=0.027). Between D0 and D28, a significant improvement in BCVA was observed for the 0.01 mL group (P=0.017). No significant differences in IOP measurements were observed for any group. Safety analysis revealed no serious ocular or systemic events. CONCLUSION AND RELEVANCE: Intravitreal dexamethasone solution is effective in reducing macular thickness secondary to DME in the short-term. Improvement in short-term visual acuity was observed. Although DME requires long-term treatment, it may be a low cost therapeutic option used in specific short-term situations.Trial registration: NCT03608839 (http://www.clinicaltrials.gov).

Genotoxic and cytotoxic effects of iron sulfate in cultured human lymphocytes treated in different phases of cell cycle.

Iron (Fe) is a common chemical element that is essential for organisms as a co-factor in oxygen transport, but that in high amounts presents a significant risk of neurodegenerative disorders. The objective of this study was to evaluate the mutagenic potential of iron sulfate. The comet assay and chromosome aberration (CA) analysis were applied to determine the DNA-damaging and clastogenic effects of iron sulfate. Human lymphocytes were treated in the quiescent phase for the comet assay and proliferative phase during the G1, G1/S, S (pulses of 1 and 6 h), and G2 phases of the cell cycle for CA analysis, with 1.25, 2.5 and 5 microg/mL concentrations of FeSO(4).7H2O. All tested concentrations were cytotoxic and reduced significantly the mitotic index (MI) in all phases of the cell cycle. They also induced CA in G1, G1/S and S (pulses of 1 and 6 h) phases. Iron sulfate also induced polyploidy in cells treated during G1. In the comet assay, this metal did not induce significant DNA damage. Our results show that Fe causes alteration and inhibition of DNA synthesis only in proliferative cells, which explain the concomitant occurrence of mutagenicity and cytotoxicity, respectively, in the lymphocytes studied.

Genotoxic and cytotoxic effects of manganese chloride in cultured human lymphocytes treated in different phases of cell cycle.

Manganese (Mn) has a natural occurrence and is necessary during the initial periods of the development. However, in high concentrations, Mn can be related to neurodegenerative disorders. The aim of the present study was to evaluate the mutagenic potential of manganese chloride (MnCl2.4H2O). Comet assay and chromosome aberrations analysis were applied to determine the DNA-damaging and clastogenic effects of MnCl2.4H2O. Cultured human lymphocytes were treated with 15, 20 and 25 microM manganese chloride during the G1, G1/S, S (pulses of 1 and 6h), and G2 phases of the cell cycle. All tested concentrations were cytotoxic and reduced significantly the mitotic index in G1, G1/S and S (1 and 6h) treatments, while in G2 treatment only the higher concentrations (20 and 25 microM) showed cytotoxic effects. Clastogenicity and DNA damage were found only in treatments with the highest concentration (25 microM). Chromosome aberrations were found exclusively in the G2 phase of the cell cycle. The absence of polyploidy in mitosis, suggests that manganese does not affect the formation of the mitotic spindle with the concentrations tested. The genotoxicity found in G2 phase and in the comet assay can be related to the short time of treatment in both cases.

Genotoxic effects of tanshinones from Hyptis martiusii in V79 cell line.

The genotoxic effect of two tanshinones isolated from roots of Hyptis martiussi Benth (Labiatae) was studied using V79 (Chinese hamster lung) cells by the alkaline comet assay and micronucleus test. Tanshinones were incubated with the cells at concentrations of 1, 3, 6 and 12 microg/mL for 3 h. Tanshinones were shown to be quite strongly genotoxic against V79 cells at all tested concentrations. The data obtained provide support to the view that tanshinones has DNA damaging activity in cultured V79 cells under the conditions of the assays.

In vitro antitumor effect of a lignan isolated from Combretum fruticosum, trachelogenin, in HCT-116 human colon cancer cells.

The use of natural products in therapeutics has been growing over the years. Lignans are compounds with large pharmaceutical use, which has aroused interest in the search for new drugs to treat diseases. The present study evaluated the cytotoxicity of (-)-trachelogenin, a dibenzylbutyrolactone type lignan isolated from Combretum fruticosum, against several tumor and non-tumor cell lines using the MTT assay and its possible mechanism of action. (-)-Trachelogenin showed IC50 values ranging of 0.8-32.4µM in SF-295 and HL-60 cell lines, respectively and IC50 values >64µM in non-tumor cell lines. (-)-trachelogenin persistently induced autophagic cell death, with cytoplasmic vacuolization and formation of autophagosomes mediated by increasing LC3 activation and altering the expression levels of Beclin-1.

Assessment of the antibacterial, cytotoxic and antioxidant activities of Morus nigra L. (Moraceae).

This study was carried out to assess the antibacterial, cytotoxic and antioxidant activities of extracts of Morus nigra L. HPLC was used to determine the fingerprint chromatogram of the crude ethanolic extract (Mn-EtOH). The antibacterial effect was assessed through the method of microdilution. The cytotoxicity was tested against human tumour cell lines using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The total phenolic and flavonoid contents were also assessed through the Folin-Ciocalteu and aluminum chloride methods, respectively. Antioxidant activities of the extracts were evaluated by using 2,2-diphenyl-1-picrylhydrazil (DPPH) radical scavenging and ß-carotene-linoleic acid bleaching methods. The presence of phenolic compounds in Mn-EtOH was confirmed using HPLC. The extracts showed activity against most microorganisms tested. The extracts did not show any expressive antiproliferative effect in the assessment of cytotoxicity. The most significant total phenolic content was 153.00 ± 11.34 mg of gallic acid equivalent/g to the ethyl acetate extract (AcOEt). The total flavonoid content was 292.50 ± 70.34 mg of catechin equivalent/g to the AcOEt extract, which presented the best antioxidant activity (IC50 50.40 ± 1.16 µg/mL) for DPPH scavenging. We can conclude that this species shows strong antibacterial and antioxidant activities, as well as weak cytotoxic effects.

Inhibition of sea urchin fertilization by plant lectins.

Effects of plant lectins on sea urchin (Lytechinus variegatus) fertilization and a partial characterization of lectin-binding involved in the process were evaluated. IC50 doses for inhibition of fertilization varied from 4.1 to 135.5 microg/ml when the lectins were pre-incubated with sperms and from 0.7 to 33.4 microg/ml when pre-incubated with eggs. Such effects were reversed when the lectins were heat inactivated. FITC-labeled lectins bound egg surfaces while their denatured forms did not. Glucose/mannose specific lectins bound weaker to eggs when pre-incubated with the glycoprotein bovine lactotransferrin. None of the glycoproteins assayed diminished FITC patterns of the Gal/GalNAc binding lectins. Pre-incubation of Glucose/mannose binding lectins with eggs did not alter binding of Gal/GalNAc lectins. Lectins with distinct competencies for binding monosaccharide and glycoconjugates were able to inhibit sea urchin fertilization.

Genotoxic effects of aluminum chloride in cultured human lymphocytes treated in different phases of cell cycle.

Aluminum (Al) is the most abundant metal and the third common chemical element on earth. It is known that Al is toxic, especially its trivalent form (Al(3+)), that represents the its most soluble form. Al intoxication is related to some pathogenic disorders, principally neurodegeneratives ones as Parkinson and Alzheimer diseases. The present study aimed to evaluate the mutagenic potential of aluminum chloride (AlCl(3)). Comet assay and chromosome aberrations analysis were applied to evaluate the DNA-damaging and clastogenic effects of AlCl(3), respectively, in different phases of the cell cycle. Cultured human lymphocytes were treated with 5, 10, 15 and 25 microM aluminum chloride during the G1, G1/S, S (pulses of 1 and 6h), and G2 phases of the cell cycle. All tested concentrations were cytotoxic and reduced significantly the mitotic index in all phases of cell cycle. They also induced DNA damage and were clastogenic in all phases of cell cycle, specially in S phase. AlCl(3) also induced endoreduplication and polyploidy in treatments performed during G1 phase. The presence of genotoxicity and polyploidy on interphase and mitosis, respectively, suggests that aluminum chloride is clastogenic and indirectly affects the construction of mitotic fuse in all tested concentrations.

Isolation and characterization of 2-pyridone alkaloids and alloxazines from Beauveria bassiana.

Two novel compounds bearing heterocyclic nitrogen, 2-pyridone alkaloid (1) and alloxazine derivative (2), along with the known pretenellin B (3), pyridovericin (4) and lumichrome (5) were isolated from a culture of the entomopathogenic fungal strain Beauveria bassiana. The chemical structures of 2-pyridone alkaloid and alloxazine derivative were established on the basis of the interpretation of spectroscopic data. The isolated compounds were evaluated in a panel of five cancer cell lines and pyridovericin exhibited cytotoxicity (IC50, µM) against cancer cell lines: HL-60 (25.9 ± 0.3), HCT8 (34.6 ± 3.6), MDA-MB435 (34.8 ± 3.8) and SF295 (31.1 ± 0.6). Considering that other pyridone compounds display good cytotoxic activity, it would be suggested to obtain new semi synthetic derivatives of pyridovericin, for the development of new cytotoxic chemical entities.

Polarization microscopy as a tool for quantitative evaluation of collagen using picrosirius red in different stages of CKD in cats.

Chronic kidney disease (CKD) is a relevant disease in feline clinic. The tubulointerstitial damage, with collagen deposition and fibrosis, is an important result of this process. The aim of this study was to quantify and correlate the deposition of collagen and severity of interstitial fibrosis (IF) in the kidney from cats in different stages of CKD. Kidney fragments from 10 adult cats with CKD were analyzed and stained by Masson's trichrome (MT) and Picrosirius red (PSR) for circular polarized microscopy. Random quantitative analysis was performed on MT sections to classify the degree of IF, per field area, with and without circular polarization. Statistics correlations were performed by Spearman's (ρ; p < .05). There was a significant correlation of IF quantification with the area of interstitial collagen deposition by polarized PSR (PSRp) (r = .7939, p = .0098) and nonpolarized PSR (PSRn) (r = .7781, p = .0080). There was a positive correlation of serum creatinine (sCr) at different stages of CKD with PSRp (r = .7939, p = .0098), PSRn (r = .8667, p = .0027) and MT (r = .7818, p = .0117). Correlations between the percentage of quantified area was also positive from PSRp to PSRn (r = .9030, p = .0009) and PSRp to MT (r = .7939, p = .0098). The PSRN was also correlated with MT (r = .9273, p = .0001). The correlation with IF and sCr follows the disease evolution and the quantification of collagen by PSR is an excellent tool for analyzing the disease severity at different stages.

Analysis of inherited genetic variants in ret proto-oncogene of Brazilian patients with apparently sporadic medullary thyroid carcinoma.

Mutations in different exons of ret proto-oncogene are responsible for the development of medullary thyroid carcinoma (MTC). The mutations can occur as sporadic or as part of multiple endocrine neoplasia (MEN) type 2 hereditary syndromes. Here we report the first focused study of sporadic MTC in Brazilian patients regarding clinical and molecular analysis of ret proto-oncogene. Our study seeks to estimate the risk of hereditary MTC cases among apparently sporadic cases in a Brazilian population and describe ret genetic variants in their germinative lineage. Germinative sequence variants were screened by DNA sequencing and denaturing gradient gel electrophoresis (DGGE) analysis of exons 10, 11, 13, 14, 15, and 16 of 24 Brazilian patients with apparently sporadic MTC. We identified 1 inherited case of 24 (4%) patients with apparently sporadic MTC. Polymorphisms for the ret proto-oncogene coding region were identified in codon 769 of exon 13 (LeuCTT--> LeuCTG) at a frequency of 13% (3/24) and in codon 904 of exon 15 (SerTCC--> SerTCG) at a frequency of 16.6% (4/24). The observed frequency (4%) of inherited disease among apparent sporadic MTC strengthens routine application of ret proto-oncogene germinative DNA screening in all cases of apparently sporadic MTC ascertained at Brazilian cancer hospitals.

Genotoxicity evaluation of kaurenoic acid, a bioactive diterpenoid present in Copaiba oil.

Copaiba oil extracted from the Amazon traditional medicinal plant Copaifera langsdorffii is rich in kaurenoic acid (ent-kaur-16-en-19-oic acid), a diterpene that has been shown to exert anti-inflammatory, hypotensive, and diuretic effects in vivo and antimicrobial, smooth muscle relaxant and cytotoxic actions in vitro. This study evaluated its potential genotoxicity against Chinese hamster lung fibroblast (V79) cells in vitro, using the Comet and the micronucleus assays. Kaurenoic acid was tested at concentrations of 2.5, 5,10, 30 and 60 microg/mL. The positive control was the methylmethanesulfonate (MMS). The duration of the treatment of V79 cells with these agents was 3h. The results showed that unlike MMS, kaurenoic acid (2.5, 5, and 10 microg/mL) failed to induce significantly elevated cell DNA damage or the micronucleus frequencies in the studied tests. However, exposure of V79 cells to higher concentrations of kaurenoic acid (30 and 60 microg/mL) caused significant increases in cell damage index and frequency. The data obtained provide support to the view that the diterpene kaurenoic acid induces genotoxicity.

In vivo growth-inhibition of Sarcoma 180 by piplartine and piperine, two alkaloid amides from Piper.

Piplartine {5,6-dihydro-1-[1-oxo-3-(3,4,5-trimethoxyphenyl)-2-propenyl]-2(1H)pyridinone} and piperine {1-5-(1,3)-benzodioxol-5-yl)-1-oxo-2,4-pentadienyl]piperidine} are alkaloid amides isolated from Piper. Both have been reported to show cytotoxic activity towards several tumor cell lines. In the present study, the in vivo antitumor activity of these compounds was evaluated in 60 female Swiss mice (N = 10 per group) transplanted with Sarcoma 180. Histopathological and morphological analyses of the tumor and the organs, including liver, spleen, and kidney, were performed in order to evaluate the toxicological aspects of the treatment with these amides. Administration of piplartine or piperine (50 or 100 mg kg(-1) day(-1) intraperitoneally for 7 days starting 1 day after inoculation) inhibited solid tumor development in mice transplanted with Sarcoma 180 cells. The inhibition rates were 28.7 and 52.3% for piplartine and 55.1 and 56.8% for piperine, after 7 days of treatment, at the lower and higher doses, respectively. The antitumor activity of piplartine was related to inhibition of the tumor proliferation rate, as observed by reduction of Ki67 staining, a nuclear antigen associated with G1, S, G2, and M cell cycle phases, in tumors from treated animals. However, piperine did not inhibit cell proliferation as observed in Ki67 immunohistochemical analysis. Histopathological analysis of liver and kidney showed that both organs were reversibly affected by piplartine and piperine treatment, but in a different way. Piperine was more toxic to the liver, leading to ballooning degeneration of hepatocytes, accompanied by microvesicular steatosis in some areas, than piplartine which, in turn, was more toxic to the kidney, leading to discrete hydropic changes of the proximal tubular and glomerular epithelium and tubular hemorrhage in treated animals.

Clinical Presentation Resembling Mucosal Disease Associated with 'HoBi'-like Pestivirus in a Field Outbreak.

The genus Pestivirus of the family Flaviviridae consists of four recognized species: Bovine viral diarrhoea virus 1 (BVDV-1), Bovine viral diarrhoea virus 2 (BVDV-2), Classical swine fever virus (CSFV) and Border disease virus (BDV). Recently, atypical pestiviruses ('HoBi'-like pestiviruses) were identified in batches of contaminated foetal calf serum and in naturally infected cattle with and without clinical symptoms. Here, we describe the first report of a mucosal disease-like clinical presentation (MD) associated with a 'HoBi'-like pestivirus occurring in a cattle herd. The outbreak was investigated using immunohistochemistry, antibody detection, viral isolation and RT-PCR. The sequence and phylogenetic analysis of 5'NCR, N(pro) and E2 regions of the RT-PCR positive samples showed that four different 'HoBi'-like strains were circulating in the herd. The main clinical signs and lesions were observed in the respiratory and digestive systems, but skin lesions and corneal opacity were also observed. MD characteristic lesions and a pestivirus with cytopathic biotype were detected in one calf. The present study is the first report of a MD like presentation associated with natural infection with 'HoBi'-like pestivirus. This report describes the clinical signs and provides a pathologic framework of an outbreak associated with at least two different 'HoBi'-like strains. Based on these observations, it appears that these atypical pestiviruses are most likely underdiagnosed in Brazilian cattle.