A highly stable, non-digestible lectin from Pomacea diffusa unveils clade-related protection systems in apple snail eggs.

The acquisition of egg protection is vital for species survival. Poisonous eggs from Pomacea apple snails have defensive macromolecules for protection. Here we isolated and characterized a novel lectin called PdPV1 that is massively accumulated in the eggs of Pomacea diffusa and seems part of its protective cocktail. The native protein, an oligomer of ca 256 kDa, has high structural stability, withstanding 15 min boiling and denaturing by SDS. It resists in vitro proteinase digestion and displays structural stability between pH 2.0 and pH 12.0, and up to 85°C. These properties, as well as its subunit sequences, glycosylation pattern, presence of carotenoids, size and global shape resemble those of its orthologs from other Pomacea. Furthermore, like members of the canaliculata clade, PdPV1 is recovered unchanged in feces of mice ingesting it, supporting an anti-nutritive defensive function. PdPV1 also displays a strong hemagglutinating activity, specifically recognizing selected ganglioside motifs with high affinity. This activity is only shared with PsSC, a perivitelline from the same clade (bridgesii clade). As a whole, these results indicate that species in the genus Pomacea have diversified their egg defenses: those from the bridgesii clade are protected mostly by non-digestible lectins that lower the nutritional value of eggs, in contrast with protection by neurotoxins of other Pomacea clades, indicating that apple snail egg defensive strategies are clade specific. The harsh gastrointestinal environment of predators would have favored their appearance, extending by convergent evolution the presence of plant-like highly stable lectins, a strategy not reported in other animals.

Hemocyanin of the caenogastropod Pomacea canaliculata exhibits evolutionary differences among gastropod clades.

Structural knowledge of gastropod hemocyanins is scarce. To better understand their evolution and diversity we studied the hemocyanin of a caenogastropod, Pomacea canaliculata (PcH). Through a proteomic and genomic approach, we identified 4 PcH subunit isoforms, in contrast with other gastropods that usually have 2 or 3. Each isoform has the typical Keyhole limpet-type hemocyanin architecture, comprising a string of eight globular functional units (FUs). Correspondingly, genes are organized in eight FUs coding regions. All FUs in the 4 genes are encoded by more than one exon, a feature not found in non- caenogastropods. Transmission electron microscopy images of PcH showed a cylindrical structure organized in di, tri and tetra-decamers with an internal collar structure, being the di and tri-decameric cylinders the most abundant ones. PcH is N-glycosylated with high mannose and hybrid-type structures, and complex-type N-linked glycans, with absence of sialic acid. Terminal ß-N-GlcNAc residues and nonreducing terminal α-GalNAc are also present. The molecule lacks O-linked glycosylation but presents the T-antigen (Gal-ß1,3-GalNAc). Using an anti-PcH polyclonal antibody, no cross-immunoreactivity was observed against other gastropod hemocyanins, highlighting the presence of clade-specific structural differences among gastropod hemocyanins. This is, to the best of our knowledge, the first gene structure study of a Caenogastropoda hemocyanin.

A lectin of a non-invasive apple snail as an egg defense against predation alters the rat gut morphophysiology.

The eggs of the freshwater Pomacea apple snails develop above the water level, exposed to varied physical and biological stressors. Their high hatching success seems to be linked to their proteins or perivitellins, which surround the developing embryo providing nutrients, sunscreens and varied defenses. The defensive mechanism has been unveiled in P. canaliculata and P. maculata eggs, where their major perivitellins are pigmented, non-digestible and provide a warning coloration while another perivitellin acts as a toxin. In P. scalaris, a species sympatric to the former, the defense strategy seems different, since no toxin was found and the major perivitellin, PsSC, while also colored and non-digestible, is a carbohydrate-binding protein. In this study we examine the structure and function of PsSC by sequencing its subunits, characterizing its carbohydrate binding profile and evaluating its effect on gut cells. Whereas cDNA sequencing and database search showed no lectin domain, glycan array carbohydrate binding profile revealed a strong specificity for glycosphingolipids and ABO group antigens. Moreover, PsSC agglutinated bacteria in a dose-dependent manner. Inspired on the defensive properties of seed lectins we evaluated the effects of PsSC on intestinal cells both in vitro (Caco-2 and IEC-6 cells) and in the gastrointestinal tract of rats. PsSC binds to Caco-2 cell membranes without reducing its viability, while a PsSC-containing diet temporarily induces large epithelium alterations and an increased absorptive surface. Based on these results, we propose that PsSC is involved in embryo defenses by altering the gut morphophysiology of potential predators, a convergent role to plant defensive lectins.

Convergent evolution of plant and animal embryo defences by hyperstable non-digestible storage proteins.

Plants have evolved sophisticated embryo defences by kinetically-stable non-digestible storage proteins that lower the nutritional value of seeds, a strategy that have not been reported in animals. To further understand antinutritive defences in animals, we analysed PmPV1, massively accumulated in the eggs of the gastropod Pomacea maculata, focusing on how its structure and structural stability features affected its capacity to withstand passage through predator guts. The native protein withstands >50 min boiling and resists the denaturing detergent sodium dodecyl sulphate (SDS), indicating an unusually high structural stability (i.e., kinetic stability). PmPV1 is highly resistant to in vitro proteinase digestion and displays structural stability between pH 2.0-12.0 and 25-85 °C. Furthermore, PmPV1 withstands in vitro and mice digestion and is recovered unchanged in faeces, supporting an antinutritive defensive function. Subunit sequence similarities suggest a common origin and tolerance to mutations. This is the first known animal genus that, like plant seeds, lowers the nutritional value of eggs by kinetically-stable non-digestible storage proteins that survive the gut of predators unaffected. The selective pressure of the harsh gastrointestinal environment would have favoured their appearance, extending by convergent evolution the presence of plant-like hyperstable antinutritive proteins to unattended reproductive stages in animals.

Distribution and current infection status of Biomphalaria straminea in Hong Kong.

BACKGROUND: Schistosomiasis, also generally known as snail fever, is a parasitic disease caused by trematode flatworms of the genus Schistosoma. In Hong Kong and mainland China, the freshwater snail Biomphalaria straminea has been introduced and has the potential to transmit intestinal schistosomiasis caused by S. mansoni, a parasite of man which has a wide distribution in Africa and parts of the New World, especially Brazil. The first identification of B. straminea in Hong Kong dates back to the 1970s, and its geographical distribution, phylogenetic relationships, and infection status have not been updated for more than 30 years. Thus, this study aims to reveal the distribution and current infection status of B. straminea in contemporary Hong Kong. METHODS: Snails were collected from different parts of Hong Kong from July 2016 to January 2017. Both anatomical and molecular methods were applied to identify B. straminea. Cytochrome c oxidase subunit 1 (cox1), internal transcribed spacer 1 (ITS1), 5.8S rDNA, internal transcribed spacer 2 (ITS2), and 16S ribosomal DNA (rDNA) were sequenced from individual snails and analyzed. To detect the presence of S. mansoni, both biopsy and PCR analyses were carried out. RESULTS: Using both anatomical and molecular analyses, this study demonstrated the existence of black- and red-coloured shell B. straminea in different districts in the New Territories in Hong Kong, including places close to the mainland China border. None of the B. straminea (n = 87) investigated were found to be infected with S. mansoni when tested by biopsy and PCR. The Hong Kong B. straminea are genetically indistinguishable, based on the chosen molecular markers (cox1, ITS1-5.8S-ITS2, and 16S rDNA), and are similar to those obtained in mainland China and South America. CONCLUSION: Biomphalaria straminea is now well established in freshwater habitats in Hong Kong. No evidence of infection with S. mansoni has been found. Surveillance should be continued to monitor and better understand this schistosomiasis intermediate host in mainland China and Hong Kong.

Transcriptome sequencing and comparative analysis reveal long-term flowing mechanisms in Hevea brasiliensis latex.

BACKGROUND: The rubber tree, Hevea brasiliensis, is a major commercial source of natural rubber. Increasing the rubber yield of rubber trees is a very serious problem since the demands for high quality rubber materials are great. Establishment of a tapping system is based on an estimate of tapping intensity from the rubber tree. Latex flowing time is one of the most critical factors that determine the rubber yield. Long-term flow is a type of phenomenon of the rubber tree latex with longer flowing time than normal latex flow, and is always caused by intensive tapping. Thus, transcriptome and expression profiling data for long-term flowing latex (LFL) are needed as an important resource to identify genes and to better understand the biological mechanisms of latex flow in rubber trees. RESULTS: The transcripts were sequenced using the Illumina sequencing platform. After cleaning, quality checks and sequencing, 98,697 transcripts and 38,584 unigenes were assembled with the mean size of 1437.31bp and 923.86bp, respectively. In BLAST searches of our database against public databases, 65.17% (25,147) of the unigenes were annotated with gene descriptions, conserved protein domains, or gene ontology terms. Functional categorization further revealed 853 individual unigenes related to long-term flow. According to KEGG classification, the clusters for "cysteine and methionine metabolism", "energy", "oxidative phosphorylation", "terpenoid backbone biosynthesis", "plant hormone signal transduction" and "copper, potassium transporter" were significantly enriched metabolic pathways. CONCLUSIONS: We conducted high-resolution transcriptome profiling related to LFL in H. brasiliensis. The research facilitates further studies on gene discovery and on the molecular mechanisms related to the estimation of tapping intensity and prolonging latex flowing time. We concluded that it was necessary to improve energy supplies for intensive tapping and the copper ion content of rubber tree latex could be considered as a standard to estimate tapping intensity.

Update on the distribution and phylogenetics of Biomphalaria (Gastropoda: Planorbidae) populations in Guangdong Province, China.

In 1973 planorbid snails then identified as Biomphalaria straminea were discovered in Hong Kong, China. It was assumed that these snails had been introduced to Hong Kong via the import of tropical fish by air from South America. In 2012 Biomphalaria were found for the first time in Guangdong Province, China. In view of the renewed interest in these invasive snails, a morphological and DNA-sequence based phylogenetic study was undertaken for seven populations of Biomphalaria snails collected in Guangdong. Morphologically and phylogenetically, five of the populations clustered more closely with Biomphalaria kuhniana than with B. straminea. Levels of genetic diversity among the populations were about half those of autochthonous populations in Brazil, the phylogenetic relationships did not correlate with a radiation from any one international port in China, and different lineages appeared associated with different ports. Consequently in explaining the current distribution of the snails, multiple colonization events, each establishing a new local snail population near to maritime international container ports, were considered more likely than the spread of snails from Hong Kong to China. The displacement of B. straminea by B. kuhniana in Guangdong is considered as an explanation for the habitat changes observed among the snails between Hong Kong in the 1980s and the present. The conclusions of the study are that any risk of Schistosoma mansoni transmission in China is more likely to come from parasite importation in the intramolluscan stage, than from transmission by migrant workers from South America or Africa. In addition, although likely to be rare, sporadic outbreaks of imported schistosomiasis (caused by invading infected snails) could be a threat to public health in the vicinity of International container ports (not only in Guangdong Province). Further work is called for to investigate further the presence of B. kuhniana and its potential interactions with B. straminea (the former is thought to be incompatible with S. mansoni), and the responses of Chinese Biomphalaria to potential competitors such as Thiaridae. The current expansion of container ports in Brazil and Venezuela, and the increase in trade with China, is likely to accentuate any current risk of imported schistosomiasis, and surveillance around ports in China, together with further research, are necessary.

Novel animal defenses against predation: a snail egg neurotoxin combining lectin and pore-forming chains that resembles plant defense and bacteria attack toxins.

Although most eggs are intensely predated, the aerial egg clutches from the aquatic snail Pomacea canaliculata have only one reported predator due to unparalleled biochemical defenses. These include two storage-proteins: ovorubin that provides a conspicuous (presumably warning) coloration and has antinutritive and antidigestive properties, and PcPV2 a neurotoxin with lethal effect on rodents. We sequenced PcPV2 and studied whether it was able to withstand the gastrointestinal environment and reach circulation of a potential predator. Capacity to resist digestion was assayed using small-angle X-ray scattering (SAXS), fluorescence spectroscopy and simulated gastrointestinal proteolysis. PcPV2 oligomer is antinutritive, withstanding proteinase digestion and displaying structural stability between pH 4.0-10.0. cDNA sequencing and protein domain search showed that its two subunits share homology with membrane attack complex/perforin (MACPF)-like toxins and tachylectin-like lectins, a previously unknown structure that resembles plant Type-2 ribosome-inactivating proteins and bacterial botulinum toxins. The protomer has therefore a novel AB toxin combination of a MACPF-like chain linked by disulfide bonds to a lectin-like chain, indicating a delivery system for the former. This was further supported by observing PcPV2 binding to glycocalix of enterocytes in vivo and in culture, and by its hemaggutinating, but not hemolytic activity, which suggested an interaction with surface oligosaccharides. PcPV2 is able to get into predator's body as evidenced in rats and mice by the presence of circulating antibodies in response to sublethal oral doses. To our knowledge, a lectin-pore-forming toxin has not been reported before, providing the first evidence of a neurotoxic lectin in animals, and a novel function for ancient and widely distributed proteins. The acquisition of this unique neurotoxic/antinutritive/storage protein may confer the eggs a survival advantage, opening new perspectives in the study of the evolution of animal defensive strategies.

Preparation of infertile male rabbits by local electron beam irradiation for intratesticular transplantation of autologous bone marrow stem cells.

PURPOSE: To explore an efficient and safe protocol for the preparation of infertile male rabbits from which bone marrow stem cells (BMSCs) could be isolated and cultured. METHODS: Autologous BMSCs could be used for intratesticular transplantation and male infertility research. For this model, various doses (e.g., 6, 8, 10, or 12 Gy) of electron beam irradiation from a linear accelerator were locally applied to the scrotum of 5-month-old male New Zealand white rabbits. The effects of irradiation were compared between treatment groups, and with age-matched normal controls. Both morphology and hollow ratios of seminiferous tubules (HRST) were examined two, four, six, eight and 12-weeks post-irradiation. RESULTS: The seminiferous epithelium showed varying degrees of damage in all treatment groups compared with unirradiated controls, yet Sertoli and Leydig cells appeared unaffected. A dose-dependent response in spermatogenesis was also observed. BMSCs that were isolated and cultured from rabbits of the normal control group and the 12 Gy treatment group were compared with respect to morphology and growth. Starting at 6 weeks, HRST of the 12 Gy-treatment group were stable, and were the highest among all the groups. BMSCs from rabbits treated with 12 Gy also exhibited similar growth as the control group. CONCLUSION: Local dose of 12 Gy to the testes of 5-month-old male New Zealand rabbits is a protocol with which to obtain autologous bone marrow stem cells.

Preparation of infertile male rabbits by local electron beam irradiation for intratesticular transplantation of autologous bone marrow stem cells

PURPOSE: To explore an efficient and safe protocol for the preparation of infertile male rabbits from which bone marrow stem cells (BMSCs) could be isolated and cultured. METHODS: Autologous BMSCs could be used for intratesticular transplantation and male infertility research. For this model, various doses (e.g., 6, 8, 10, or 12 Gy) of electron beam irradiation from a linear accelerator were locally applied to the scrotum of 5-month-old male New Zealand white rabbits. The effects of irradiation were compared between treatment groups, and with age-matched normal controls. Both morphology and hollow ratios of seminiferous tubules (HRST) were examined two, four, six, eight and 12-weeks post-irradiation. RESULTS: The seminiferous epithelium showed varying degrees of damage in all treatment groups compared with unirradiated controls, yet Sertoli and Leydig cells appeared unaffected. A dose-dependent response in spermatogenesis was also observed. BMSCs that were isolated and cultured from rabbits of the normal control group and the 12 Gy treatment group were compared with respect to morphology and growth. Starting at 6 weeks, HRST of the 12 Gy-treatment group were stable, and were the highest among all the groups. BMSCs from rabbits treated with 12 Gy also exhibited similar growth as the control group. CONCLUSION: Local dose of 12 Gy to the testes of 5-month-old male New Zealand rabbits is a protocol with which to obtain autologous bone marrow stem cells.

Preparation of infertile male rabbits by local electron beam irradiation for intratesticular transplantation of autologous bone marrow stem cells

PURPOSE: To explore an efficient and safe protocol for the preparation of infertile male rabbits from which bone marrow stem cells (BMSCs) could be isolated and cultured. METHODS: Autologous BMSCs could be used for intratesticular transplantation and male infertility research. For this model, various doses (e.g., 6, 8, 10, or 12 Gy) of electron beam irradiation from a linear accelerator were locally applied to the scrotum of 5-month-old male New Zealand white rabbits. The effects of irradiation were compared between treatment groups, and with age-matched normal controls. Both morphology and hollow ratios of seminiferous tubules (HRST) were examined two, four, six, eight and 12-weeks post-irradiation. RESULTS: The seminiferous epithelium showed varying degrees of damage in all treatment groups compared with unirradiated controls, yet Sertoli and Leydig cells appeared unaffected. A dose-dependent response in spermatogenesis was also observed. BMSCs that were isolated and cultured from rabbits of the normal control group and the 12 Gy treatment group were compared with respect to morphology and growth. Starting at 6 weeks, HRST of the 12 Gy-treatment group were stable, and were the highest among all the groups. BMSCs from rabbits treated with 12 Gy also exhibited similar growth as the control group. CONCLUSION: Local dose of 12 Gy to the testes of 5-month-old male New Zealand rabbits is a protocol with which to obtain autologous bone marrow stem cells.(AU)

Comparative study on ureteroscopic lithotripsy and laparoscopic ureterolithotomy for treatment of unilateral upper ureteral stones.

PURPOSE: To compare the curative effects of ureteroscopic lithotripsy and laparoscopic ureterolithotomy for unilateral upper ureteral stones, and to explore optimal surgical indications and skills. METHODS: Fifty cases of unilateral upper ureteral stones were randomly divided into two groups: one group underwent ureteroscopic holmium laser lithotripsy under epidural or lumbar anesthesia (n=25), and another group underwent laparoscopic ureterolithotomy under general anesthesia (n=25). Double-J stent was routinely indwelled in both groups. Operating time, postoperative hospitalization time, stone clearance rate and perioperative complications were compared. RESULTS: Operation was successfully performed in all 50 cases, and no open surgery was converted in any case. In the ureteroscopy and laparoscopy groups, the mean operating time was 49.0 ± 10.7 min and 41.8 ± 8.0 min (t=2.68, P=0.00999), respectively, their hospitalization time was 2.8 ± 1.3 days vs. 2.9 ± 0.8 days (t =-0.40, P=0.69413), and stone clearance rate was 88.0% (22/25) vs. 100% (25/25). Stone moved to the renal pelvis in three cases in the ureteroscopy group, and residual stones were removed by extracorporeal shock-wave lithotripsy (ESWL). All patients were followed up for more than three months, and no serious complications such as ureterostenosis occurred. CONCLUSIONS: Laparoscopic ureterolithotomy has a higher stone clearance rate and shorter operation time compared with ureteroscopic lithotripsy. Laparoscopic ureterolithotomy is one safe and effective treatment on unilateral upper ureteral stones.

Comparative study on ureteroscopic lithotripsy and laparoscopic ureterolithotomy for treatment of unilateral upper ureteral stones / Estudo comparativo entre litotripsia e ureterolitotomia laparoscópica no tratamento de cálculos unilaterais altos

PURPOSE: To compare the curative effects of ureteroscopic lithotripsy and laparoscopic ureterolithotomy for unilateral upper ureteral stones, and to explore optimal surgical indications and skills. METHODS: Fifty cases of unilateral upper ureteral stones were randomly divided into two groups: one group underwent ureteroscopic holmium laser lithotripsy under epidural or lumbar anesthesia (n=25), and another group underwent laparoscopic ureterolithotomy under general anesthesia (n=25). Double-J stent was routinely indwelled in both groups. Operating time, postoperative hospitalization time, stone clearance rate and perioperative complications were compared. RESULTS: Operation was successfully performed in all 50 cases, and no open surgery was converted in any case. In the ureteroscopy and laparoscopy groups, the mean operating time was 49.0±10.7 min and 41.8±8.0 min (t=2.68, P=0.00999), respectively, their hospitalization time was 2.8±1.3 days vs. 2.9±0.8 days (t =-0.40, P=0.69413), and stone clearance rate was 88.0 percent (22/25) vs. 100 percent (25/25). Stone moved to the renal pelvis in three cases in the ureteroscopy group, and residual stones were removed by extracorporeal shock-wave lithotripsy (ESWL). All patients were followed up for more than three months, and no serious complications such as ureterostenosis occurred. CONCLUSIONS: Laparoscopic ureterolithotomy has a higher stone clearance rate and shorter operation time compared with ureteroscopic lithotripsy. Laparoscopic ureterolithotomy is one safe and effective treatment on unilateral upper ureteral stones.

OBJETIVO: Comparar os efeitos curativos da litotripsia ureteroscópica e a ureterolitotomia laparoscópica para cálculos unilaterais altos e pesquisar as indicações e resultados. MÉTODOS: Cinquenta casos de cálculos unilaterais altos foram distribuídos aleatoriamente em dois grupos: um grupo submetido a litotripsia ureteroscópica com laser holmium sob anestesia epidural ou lombar (n=25) e outro grupo submetido a ureterolitotomia laparoscópica sob anestesia geral (n=25). Duplo-J stent foi rotineiramente instalado em ambos os grupos. Comparou-se o tempo operatório, tempo de hospitalização pós-operatória, nível de desaparecimento dos cálculos e complicações pós-operatórias. RESULTADOS: Atos operatórios nos 50 casos sem ocorrências e nenhum ato convertido. Nos grupos por ureteroscopia e laparoscopia, o tempo operatório médio foi 49,0±10,7 minutos e 41,8±8,0 minutos (t=2,68, P=0,00999) respectivamente, tempo de hospitalização foi 2,8±1,3 dias vs. 2,9±0,8 dias (t=0,40, P=0,69413) e o nível de desaparecimento dos cálculos foi 88.0 por cento (22/25) vs. 100 por cento (25/25). Cálculo deslocado para pelve renal em três casos no grupo ureteroscópico e cálculos residuais foram removidos por litotripsia por onda de choque extracorpóreo (ESWL). Todos pacientes foram seguidos por mais de três meses e não ocorreram complicações sérias como estenoses ureterais. CONCLUSÕES: A ureterolitotomia laparoscópica teve maior nível desaparecimento dos cálculos e tempo operatório menor comparado à litotripsia ureteroscópica A ureterolitotomia laparoscópica é um tratamento seguro e efetivo para cálculos ureterais unilaterais altos.

Comparative study on ureteroscopic lithotripsy and laparoscopic ureterolithotomy for treatment of unilateral upper ureteral stones / Estudo comparativo entre litotripsia e ureterolitotomia laparoscópica no tratamento de cálculos unilaterais altos

PURPOSE: To compare the curative effects of ureteroscopic lithotripsy and laparoscopic ureterolithotomy for unilateral upper ureteral stones, and to explore optimal surgical indications and skills. METHODS: Fifty cases of unilateral upper ureteral stones were randomly divided into two groups: one group underwent ureteroscopic holmium laser lithotripsy under epidural or lumbar anesthesia (n=25), and another group underwent laparoscopic ureterolithotomy under general anesthesia (n=25). Double-J stent was routinely indwelled in both groups. Operating time, postoperative hospitalization time, stone clearance rate and perioperative complications were compared. RESULTS: Operation was successfully performed in all 50 cases, and no open surgery was converted in any case. In the ureteroscopy and laparoscopy groups, the mean operating time was 49.0±10.7 min and 41.8±8.0 min (t=2.68, P=0.00999), respectively, their hospitalization time was 2.8±1.3 days vs. 2.9±0.8 days (t =-0.40, P=0.69413), and stone clearance rate was 88.0 percent (22/25) vs. 100 percent (25/25). Stone moved to the renal pelvis in three cases in the ureteroscopy group, and residual stones were removed by extracorporeal shock-wave lithotripsy (ESWL). All patients were followed up for more than three months, and no serious complications such as ureterostenosis occurred. CONCLUSIONS: Laparoscopic ureterolithotomy has a higher stone clearance rate and shorter operation time compared with ureteroscopic lithotripsy. Laparoscopic ureterolithotomy is one safe and effective treatment on unilateral upper ureteral stones.(AU)

OBJETIVO: Comparar os efeitos curativos da litotripsia ureteroscópica e a ureterolitotomia laparoscópica para cálculos unilaterais altos e pesquisar as indicações e resultados. MÉTODOS: Cinquenta casos de cálculos unilaterais altos foram distribuídos aleatoriamente em dois grupos: um grupo submetido a litotripsia ureteroscópica com laser holmium sob anestesia epidural ou lombar (n=25) e outro grupo submetido a ureterolitotomia laparoscópica sob anestesia geral (n=25). Duplo-J stent foi rotineiramente instalado em ambos os grupos. Comparou-se o tempo operatório, tempo de hospitalização pós-operatória, nível de desaparecimento dos cálculos e complicações pós-operatórias. RESULTADOS: Atos operatórios nos 50 casos sem ocorrências e nenhum ato convertido. Nos grupos por ureteroscopia e laparoscopia, o tempo operatório médio foi 49,0±10,7 minutos e 41,8±8,0 minutos (t=2,68, P=0,00999) respectivamente, tempo de hospitalização foi 2,8±1,3 dias vs. 2,9±0,8 dias (t=0,40, P=0,69413) e o nível de desaparecimento dos cálculos foi 88.0 por cento (22/25) vs. 100 por cento (25/25). Cálculo deslocado para pelve renal em três casos no grupo ureteroscópico e cálculos residuais foram removidos por litotripsia por onda de choque extracorpóreo (ESWL). Todos pacientes foram seguidos por mais de três meses e não ocorreram complicações sérias como estenoses ureterais. CONCLUSÕES: A ureterolitotomia laparoscópica teve maior nível desaparecimento dos cálculos e tempo operatório menor comparado à litotripsia ureteroscópica A ureterolitotomia laparoscópica é um tratamento seguro e efetivo para cálculos ureterais unilaterais altos.(AU)