Laparoscopic Liver Resection: A South American Experience with 2887 Cases.

BACKGROUND: Laparoscopic liver resections (LLR) have been increasingly performed in recent years. Most of the available evidence, however, comes from specialized centers in Asia, Europe and USA. Data from South America are limited and based on single-center experiences. To date, no multicenter studies evaluated the results of LLR in South America. The aim of this study was to evaluate the experience and results with LLR in South American centers. METHODS: From February to November 2019, a survey about LLR was conducted in 61 hepatobiliary centers in South America, composed by 20 questions concerning demographic characteristics, surgical data, and perioperative results. RESULTS: Fifty-one (83.6%) centers from seven different countries answered the survey. A total of 2887 LLR were performed, as follows: Argentina (928), Brazil (1326), Chile (322), Colombia (210), Paraguay (9), Peru (75), and Uruguay (8). The first program began in 1997; however, the majority (60.7%) started after 2010. The percentage of LLR over open resections was 28.4% (4.4-84%). Of the total, 76.5% were minor hepatectomies and 23.5% major, including 266 right hepatectomies and 343 left hepatectomies. The conversion rate was 9.7%, overall morbidity 13%, and mortality 0.7%. CONCLUSIONS: This is the largest study assessing the dissemination and results of LLR in South America. It showed an increasing number of centers performing LLR with the promising perioperative results, aligned with other worldwide excellence centers.

Attentional performance may help to identify duloxetine responders in chronic pain fibromyalgia patients.

BACKGROUND: Long-term pain affects brain in response to attention tasks. This study aimed to verify the relationship between performance in a computerized visual attention test (CVAT) and response to duloxetine in fibromyalgia patients. Duloxetine is approved for the treatment but the response is not immediate. METHODS: Patients were drawn from a sample of 74 patients with chronic pain. These patients were selected because they kept their subjective perceptions of pain as severe after 1 week of duloxetine treatment. All patients were tested in the CVAT on two occasions: the first appointment and 7 days after starting duloxetine. RESULTS: After 6 weeks, the group was subdivided into responsive and non-responsive patients. Responsiveness was defined by a subjective improvement from severe to low-intensity or no-pain after the sixth week of duloxetine treatment. Responsive patients showed objective attentional improvements in the second test. Non-respondent patients did not exhibit changes in attentional performance in the second test as compared to the first one. CONCLUSIONS: The data were interpreted considering that persistent pain in fibromyalgia is maintained by central sensitization that may be associated with functional changes in the dorsolateral prefrontal cortex and the posterior parietal cortex. In responsive patients, duloxetine treatment may be responsible for a partial recovery of these regions. This may explain the early attentional improvement observed in the responsive patients after 1 week of treatment. Thus, attentional performance may help to predict which patients will respond to duloxetine treatment even before they can demonstrate subjective improvements in pain perception. SIGNIFICANCE: This study shows that an improvement in an attentional test is a reliable predictor of the treatment response even without any improvement in the perception of pain.

Pulmonary hypertensive crisis following ethanol sclerotherapy for a complex vascular malformation.

Anhydrous ethanol is a commonly used sclerotic agent for treating vascular malformations. We describe the case of a full-term 15-day-old female with a complex venolymphatic malformation involving the face and orbit. During treatment of the lesion with ethanol sclerotherapy, she suffered acute pulmonary hypertensive crisis. We discuss the pathophysiology of pulmonary hypertension related to ethanol sclerotherapy, and propose that hemolysis plays a significant role. Recommendations for evaluation, monitoring and management of this complication are also discussed.

Genetic parameters and principal component analysis for egg production from White Leghorn hens.

The objectives of this study were to estimate genetic parameters for accumulated egg production over 3-wk periods and for total egg production over 54 wk of egg-laying, and using principal component analysis (PCA), to explore the relationships among the breeding values of these traits to identify the possible genetic relationships present among them and hence to observe which of them could be used as selection criteria for improving egg production. Egg production was measured among 1,512 females of a line of White Leghorn laying hens. The traits analyzed were the number of eggs produced over partial periods of 3 wk, thus totaling 18 partial periods (P1 to P18), and the total number of eggs produced over the period between the 17 and 70 wk of age (PTOT), thus totaling 54 wk of egg production. Estimates of genetic parameters were obtained by means of the restricted maximum likelihood method, using 2-trait animal models. The PCA was done using the breeding values of partial and total egg production. The heritability estimates ranged from 0.05 ± 0.03 (P1 and P8) to 0.27 ± 0.06 (P4) in the 2-trait analysis. The genetic correlations between PTOT and partial periods ranged from 0.19 ± 0.31 (P1) to 1.00 ± 0.05 (P10, P11, and P12). Despite the high genetic correlation, selection of birds based on P10, P11, and P12 did not result in an increase in PTOT because of the low heritability estimates for these periods (0.06 ± 0.03, 0.12 ± 0.04, and 0.10 ± 0.04, respectively). The PCA showed that egg production can be divided genetically into 4 periods, and that P1 and P2 are independent and have little genetic association with the other periods.

Egg production curve fitting using nonlinear models for selected and nonselected lines of White Leghorn hens.

Egg production curves describe the laying patterns of hen populations over time. The objectives of this study were to fit the weekly egg production rate of selected and nonselected lines of a White Leghorn hen population, using nonlinear and segmented polynomial models, and to study how the selection process changed the egg-laying patterns between these 2 lines. Weekly egg production rates over 54 wk of egg production (from 17 to 70 wk of age) were measured from 1,693 and 282 laying hens from one selected and one nonselected (control) genetic line, respectively. Six nonlinear and one segmented polynomial models were gathered from the literature to investigate whether they could be used to fit curves for the weekly egg production rate. The goodness of fit of the models was measured using Akaike's information criterion, mean square error, coefficient of determination, graphical analysis of the fitted curves, and the deviations of the fitted curves. The Logistic, Yang, Segmented Polynomial, and Grossman models presented the best goodness of fit. In this population, there were significant differences between the parameter estimates of the curves fitted for the selected and nonselected lines, thus indicating that the effect of selection changed the shape of the egg production curves. The selection for egg production was efficient in modifying the birds' egg production curve in this population, thus resulting in genetic gain from the 5th to the 54th week of egg laying and improved the peak egg production and the persistence of egg laying.

Estimation of genetic parameters for partial egg production periods by means of random regression models.

We estimated genetic parameters for egg production in different periods by means of random regression models, aiming at selection based on partial egg production from a generation of layers. The production was evaluated for each individual by recording the number of eggs produced from 20 to 70 weeks of age, with partial records taken every three weeks for a total of 17 periods. The covariance functions were estimated with a random regression model by the restricted maximum likelihood method. A model composed of third-order polynomials for the additive effect, ninth-order polynomials for the permanent environment, and a residual variance structure with five distinct classes, was found to be most suitable for adjusting the egg production data for laying hens. The heritability estimates varied from 0.04 to 0.14. The genetic correlations were all positive, varying from 0.10 to 0.99. Selection applied in partial egg production periods will result in greater genetic profit for the adjacent periods. However, as the distance in time between periods increases, selection becomes less efficient. Selection based on the second period (23 to 25 weeks of age), where greater heritability was estimated, would note benefit the final egg-laying cycle periods.

What is the proximate cause for size-dependent ecophysiological differences in vascular epiphytes?

Size-related variation in physiological parameters as diverse as photosynthetic capacity, abscisic acid relationships or the relative water deficit at stomatal closure have been reported for a large number of vascular epiphytes, but the proximate mechanism behind these observations has not been identified. We test four possible reasons for size-related changes in photosynthetic capacity, leaf-N content and specific leaf area: (i) plant size itself, (ii) plant age or developmental stage, (iii) previous nutrition, or (iv) previous water regime. A suite of study species and approaches were used: a 'natural experiment' with the orchid Polystachya foliosa; an experimental field study with another orchid, Dimerandra emarginata; and a study under controlled conditions with the tank bromeliad, Vriesea sanguinolenta. Neither size, age nor differences in water supply caused differences in leaf N and photosynthetic capacity, while low supply of nutrients yielded, and high supply with nutrients completely removed, size-related trends. The observed size-related trends are thus a consequence of in situ differences in nutrient acquisition. Arguably, the improved nutrient status of larger plants under natural conditions results from larger tanks, holding moisture for increasingly longer intervals, which allows longer periods of decomposition of detritus and of nutrient uptake.

Estimates of genetic parameters, and cluster and principal components analyses of breeding values related to egg production traits in a White Leghorn population.

The objectives of this paper were to identify the phenotypic egg-laying patterns in a White Leghorn line mainly selected for egg production, to estimate genetic parameters of traits related to egg production and to evaluate the genetic association between these by principal components analysis to identify trait(s) that could be used as selection criteria to improve egg production. Records of 54 wk of egg production from a White Leghorn population were used. The data set contained records of the length:width ratio of eggs at 32, 37, and 40 wk of age; egg weight at 32, 37, and 40 wk of age; BW at 54 and 62 wk of age; age at first egg; early partial egg production rate from 17 to 30 wk and from 17 to 40 wk of age; late partial egg production rate from 30 to 70 wk and from 40 to 70 wk of age; and total egg production rate (TEP). The estimates of genetic parameters between these traits were estimated by the restricted maximum likelihood method. Multivariate analyses were performed: a hierarchical cluster analysis, a nonhierarchical clustering analysis by the k-means method of weekly egg production rate to describe the egg-laying patterns of hens, and a principal components analysis using the breeding values of all traits. The highest heritability estimates were obtained for BW at 54 wk of age (0.68 ± 0.07) and age at first egg (0.53 ± 0.07). It is recommended that a preliminary clustering analysis be performed to obtain the population structure that takes into account the pattern of egg production, rather than the TEP, because hens may have the same final egg production with different patterns of egg laying. Early partial production periods were not good indicators for use in improving total egg production because these traits presented an overestimated genetic correlation with TEP because of the part-whole genetic correlation component. Egg production might be improved by selecting individuals based on TEP.

Comparison of logistic and neural network models to fit to the egg production curve of White Leghorn hens.

Neural networks are capable of modeling any complex function and can be used in the poultry and animal production areas. The aim of this study was to investigate the possibility of using neural networks on an egg production data set and fitting models to the egg production curve by applying 2 approaches, one using a nonlinear logistic model and the other using 2 artificial neural network models [multilayer perceptron (MLP) and radial basis function]. Two data sets from 2 generations of a White Leghorn strain that had been selected mainly for egg production were used. In the first data set, the mean weekly egg-laying rate was ascertained over a 54-wk egg production period. This data set was used to adjust and test the logistic model and to train and test the neural networks. The second data set, covering 52 wk of egg production, was used to validate the models. The mean absolute deviation, mean square error, and R(2) were used to evaluate the fit of the models. The MLP neural network had the best fit in the test and validation phases. The advantage of using neural networks is that they can be fitted to any kind of data set and do not require model assumptions such as those required in the nonlinear methodology. The results confirm that MLP neural networks can be used as an alternative tool to fit to egg production. The benefits of the MLP are the great flexibility and their lack of a priori assumptions when estimating a noisy nonlinear model.

Exceso de horas de trabajo en la residencia de cirugía general: resultados de una encuesta nacional / Excessive hours of work in general surgery residency: results from a national survey

Introducción: Crece el interés en el mundo sobre las causas y consecuencias del ôerror médicoõ. En EEUU se han sancionado leyes que limitan la cantidad de horas laborales de los residentes. El objetivo de este trabajo es averiguar el número de horas por semana que permanece un residente de cirugía dentro del hospital.Material y método: se realizó una encuesta desde julio de 2004 a mayo de 2005, a médicos residentes de cirugía general de todo el país. Se completaron 320 cuestionarios, de 19 programas de residencia distribuidos en 10 provincias.Resultados: Un grupo de residentes de años inferiores superan las 80 horas semanales, un segundo grupo de residentes de años superiores tiene una carga horaria notoriamente menor.Conclusiones: Existe un exceso en el número total de horas de trabajo de los residentes de cirugía. Esta carga horaria esta irregularmente distribuida, sobrecargando al grupo de residentes de años inferiores.

A biolistic process for in vitro gene transfer into chicken embryos

Chicken embryos kept in culture medium were bombarded using a high helium gas pressure biolistic device. To optimize the factors that affect transformation efficiency, the lacZ gene under control of the human cytomegalovirus immediate early enhancer/promoter was used as a reporter gene. There was an inverse relationship between survival rate and transformation efficiency. The best conditions obtained for high embryo survival and high transformation efficiency were achieved with 800 psi helium gas pressure, 500 mmHg vacuum, gold particles, an 8 cm DNA-coated microparticle flying distance to the embryo and embryo placement 0.5 cm from the center of the particle dispersion cone. Under these conditions, transformation efficiency was 100 percent, survival rate 25 percent and the number of expression units in the embryo body cells ranged from 100 to 1,000. Expression of green fluorescent protein was also detected in embryos bombarded under optimal conditions. Based on the results obtained, the biolistic process can be considered an efficient method for the transformation of chicken embryos and therefore can be used as a model system to study transient gene expression and tissue-specific promoters

A biolistic process for in vitro gene transfer into chicken embryos.

Chicken embryos kept in culture medium were bombarded using a high helium gas pressure biolistic device. To optimize the factors that affect transformation efficiency, the lacZ gene under control of the human cytomegalovirus immediate early enhancer/promoter was used as a reporter gene. There was an inverse relationship between survival rate and transformation efficiency. The best conditions obtained for high embryo survival and high transformation efficiency were achieved with 800 psi helium gas pressure, 500 mmHg vacuum, gold particles, an 8 cm DNA-coated microparticle flying distance to the embryo and embryo placement 0.5 cm from the center of the particle dispersion cone. Under these conditions, transformation efficiency was 100%, survival rate 25% and the number of expression units in the embryo body cells ranged from 100 to 1,000. Expression of green fluorescent protein was also detected in embryos bombarded under optimal conditions. Based on the results obtained, the biolistic process can be considered an efficient method for the transformation of chicken embryos and therefore can be used as a model system to study transient gene expression and tissue-specific promoters.

Inhaled helium-oxygen revisited: effect of inhaled helium-oxygen during the treatment of status asthmaticus in children.

OBJECTIVES: To assess the effects of breathing a low-density gas mixture on dyspnea and the pulsus paradoxus in children with status asthmaticus. DESIGN: In an urban academic tertiary referral center, 18 patients, aged 16 months to 16 years, who were being treated for status asthmaticus with continuously inhaled beta-agonist and intravenously administered methylprednisolone and had a pulsus paradoxus of greater than 15 mm Hg received either an 80%:20% helium-oxygen gas mixture (HELIOX patients) or room air (control patients) at 10 L/min by nonrebreathing face mask in a double-blind, randomized, controlled trial. In all patients, baseline data, including pulsus paradoxus (determined by sphygmomanometer or arterial catheter blood pressure readings), respiratory rate, heart rate, investigator-scored dyspnea index, and oxygen saturation, were compared with values obtained 15 minutes during and after intervention. In a subset of patients, peak flows before and after breathing HELIOX or room air were measured. When clinically indicated, arterial blood gases were obtained. RESULTS: The pulsus paradoxus (in millimeters of mercury) fell significantly from an initial mean value of 23.3 +/- 6.8 to 10.6 +/- 2.8 with HELIOX breathing (p < 0.001) and increased again to 18.5 +/- 7.3 after cessation of HELIOX. Peak flow increased 69.4% +/- 12.8% during HELIOX breathing (p < 0.05). The dyspnea index decreased from an initial mean value of 5.7 +/- 1.3 to 1.9 +/- 1.7 with HELIOX breathing (p < 0.0002) and increased again to 4.0 +/- 0.5 after cessation of HELIOX breathing. In control patients, there was no significant difference in pulsus paradoxus or dyspnea index at any time during the study period. Mechanical ventilation was averted in three patients in whom dyspnea lessened dramatically during breathing of HELIOX. CONCLUSION: During acute status asthmaticus, inhaled HELIOX significantly lowered the pulsus paradoxus, increased peak flow, and lessened the dyspnea index. Moreover, HELIOX spared three patients a planned intubation and caused no apparent side effects. Thus HELIOX reduces the work of breathing and may forestall respiratory failure in children with status asthmaticus, thus preventing the need for mechanical ventilation.

Liberaçäo de espermatozóides das glândulas de armazenamento em poedeiras semi-pesadas / Sequence of sperm release from host glands in hens

Utilizaram-se, em dois experimentos, 224 galinhas e 30 galos brancos (SS) e 30 galos vermelhos (MM) de linhagens para ovos castanhos. No experimento I efetuaram-se duas inseminaçöes artificiais, com intervalo de 4 h, utilizando-se, na sequência, galos SS e MM. Os tratamentos definidos pela relaçäo de sêmen em ml, foram: T11 (0,05/0,05); T12 (0,02/0,05); T13 (0,05/0,02) e T14 (0,02/0,02). No experimento II realizaram-se duas inseminaçöes por semana, com alternância de galos, iniciando-se com SS, e reforços após 48 h (MM). Os tratamentos foram: T21 (0,05/0,05); T22 (0,03/0,05); T23 (0,05/0,03) e T24 (0,03/0,03). Realizaram-se quatro incubaçöes com quatro dias de coleta, para determinaçäo da fertilidade e porcentagem de pintos vermelhos (PPV). No experimento I, a utilizaçäo de 0,02 ml de sêmen resultou em baixa fertilidade (79,61 por cento). A PPV foi maior em T12 que T13 e T14, näo diferindo de T11. O maior volume de sêmen de machos vermelhos foi responsável pela maior PPV. Näo houve diferença significativa para fertilidade no experimento II. O fenótipo da maior parte dos pintos nascidos coincidiu com o fenótipo do galo utilizado na última inseminaçäo. Concluiu-se que a liberaçäo de expermatozóide obedece uma sequência, onde os espermatozóides da última inseminaçäo säo liberados com maior intensidade, dependendo, porém, do volume do sêmen

[Infections during the hospitalization of patients with liver cirrhosis]. / Infecciones durante la internación de pacientes con cirrosis hepática.

We studied retrospectively the clinical records of 291 hospital patients with liver cirrhosis, 95% of which was alcohol related. Within this group, 114 patients presented 155 episodes of infection in 144 separate hospital admissions. In a previous communication, we pointed out that although infection was the fourth cause of admission, it was the main cause of death in this group. The main incidence of infection was among the female group. The most common infections episodes were respiratory and bacterial spontaneous peritonitis (BSP). On admission, 57% of the patients were diagnosed as belonging to the C Child group; 38% presented sepsis and 22% were hospitalary infections. The most frequent infections were respiratory and BSP. We obtained bacteriologic documentation in 55% of the episodes with prevalence of Gram negative bacilli (E. coli), with high relative frequency of neumoccocus. The most frequent complications were related to hepatic insufficiency. Global death rate was 27.1%, while nosocomial death rates were 42.1% and 40.9% for patients with Child C. We observed the highest incidence of mortality in patients with SBP and non localized bacteriemia. Survival rates were 42% for 2 years and 18% for 5 years. In summary, we stress the relevancy of checking the presence of infection systematically in every cirrhotic patient with encephalopathy and/or renal insufficiency without justifiable cause.

Infecciones durante la internación de pacientes con cirrosis hepática. / [Infections during the hospitalization of patients with liver cirrhosis]

We studied retrospectively the clinical records of 291 hospital patients with liver cirrhosis, 95

of which was alcohol related. Within this group, 114 patients presented 155 episodes of infection in 144 separate hospital admissions. In a previous communication, we pointed out that although infection was the fourth cause of admission, it was the main cause of death in this group. The main incidence of infection was among the female group. The most common infections episodes were respiratory and bacterial spontaneous peritonitis (BSP). On admission, 57

of the patients were diagnosed as belonging to the C Child group; 38

presented sepsis and 22

were hospitalary infections. The most frequent infections were respiratory and BSP. We obtained bacteriologic documentation in 55

of the episodes with prevalence of Gram negative bacilli (E. coli), with high relative frequency of neumoccocus. The most frequent complications were related to hepatic insufficiency. Global death rate was 27.1

, while nosocomial death rates were 42.1

and 40.9

for patients with Child C. We observed the highest incidence of mortality in patients with SBP and non localized bacteriemia. Survival rates were 42

for 2 years and 18

for 5 years. In summary, we stress the relevancy of checking the presence of infection systematically in every cirrhotic patient with encephalopathy and/or renal insufficiency without justifiable cause.

Beyond the conventional wisdom: USAID projects, interorganizational linkages, and institutional reform in Peru.

PIP: The case study of the linkages between departmental-level and national organizations in Peru shows how linkages can play a significant role in national reform. A general overview of current articles on interorganizational linkages and decentralization pertinent to the Peruvian context of control oriented public sectors is provided. The Peruvian institutional context and the constraints faced by decentralized development agencies called departmental development corporations (CORDES) are identified. CORDES members were provincial mayors, representatives of private sector professional and economic organizations, and heads of ministerial field offices, autonomous agencies, and public enterprises. Microregional offices were established and received public funding. USAID channeled funding through the national organizations to the CORDES in the Integrated Regional Development Project (IRD) between 1979-86, and the Disaster Relief, Rehabilitation, and Reconstruction (DRR) Project between 1983-87. The IRD and the DRR are described in addition to the decentralized organization support network established by the 2 projects. There is an analysis of how these interorganizational linkages contributed to conventional uses of linkages and unconventional or institutional reform. Reforms were facilitated by direct persuasion of central agencies to change their administrative regulations, policies, and operating procedures, and extensive lobbying by the support network to pass budgetary reform favoring CORDES and bureaucratic reorientation. Conclusions were reached on 1) the importance of assistance linkages for hastening implementation, building capacity, and overcoming organizational weaknesses (conventional wisdom); 2) the usefulness of vertical linkages in resolving administrative or technical weaknesses (unconventional wisdom); and 3) the usefulness of reinforcing project related units within key national level agencies which increases access to power while specific objectives maintain assistance orientations. Politically marginal agencies are not considered viable. These projects demonstrated that linkages are useful in supporting institutional reform and respecting country self-determination.^ieng

Rhinebothrium biorchidum n. sp., a tetraphyllidean cestode from a yellow-spotted stingray, Urolophus jamaicensis, in Jamaica.

Rhinebothrium biorchidum n. sp. (Tetraphyllidea: Phyllobothriidae) is described from the spiral valve of the yellow-spotted stingray, Urolophus jamaicensis, from Jamaica. It was most similar to R. spinicephalum Campbell 1970 but differed by having fewer proglottids (15 to 26 vs. 36 to 49), smaller peduncle (110 to 146 vs. 330 to 470) and pedicels (100 to 180 vs. 170 to 370), fewer transverse septa (6 to 8 vs. 16 to 17), fewer total loculi per bothridium (22 to 30 vs. 32 to 34) and larger ovarian lobes (148 to 310 vs. 88 to 176). A key to bitestate species of Rhinebothrium is included.

Acanthocephalan parasitism in the Western Bluebird (Sialia mexicana).

Acanthocephalan parasites of the species Plagiorhynchus (Prosthorhynchus) formosus Van Cleave, 1918, were recovered from the intestinal tracts of two male and two female wild Western Bluebirds (Sialia mexicana). Parasitism by P. formosus was considered to be a contributory cause of death of these breeding adult bluebirds. This is the first reported recovery of acanthocephalan parasites from Western Bluebirds.

Tapeworms of the Chaco Boreal, Paraguay, with two new species.

Mathevotaenia paraguayae sp. n. is described from Euphractus sexcinctus. It differs from M. didelphidis (Rud.) in having a transverse cirrus pouch anterior to the vagina. Monoecocestus mackiewiczi sp. n. was found in Phyllotis sp. It differs from M. parcitesticulatus Rego in having a much smaller scolex, a poral ovary, and a cirrus pouch 360 to 440 micrometers long. Other species reported are Taenia macrocystis, Taenia omissa, Spirometra mansonoides, Spirometra gracilis, Spirometra longicollis, Diphyllobothrium trinitatis, Atriotaenia parva, and Mathevotaenia tetragonocephala.