Vertebral osteomyelitis after spine instrumentation surgery: risk factors and management.

BACKGROUND: Vertebral osteomyelitis after spine instrumentation surgery (pVOM) is a rare complication. Most cases of infection occur early after surgery that involve skin and soft tissue and can be managed with debridement, antibiotics, and implant retention (DAIR). AIM: To identify pVOM risk factors and evaluate management strategies. METHODS: From a multicentre cohort of deep infection after spine instrumentation (IASI) cases (2010-2016), pVOM cases were compared with those without vertebral involvement. Early and late infections were defined (<60 days and >60 days after surgery, respectively). Multivariate analysis was used to explore risk factors. FINDINGS: Among 410 IASI cases, 19 (4.6%) presented with pVOM, ranging from 2% (7/347) in early to 19.1% (12/63) in late IASIs. After multivariate analysis, age (adjusted odds ratio (aOR): 1.10; 95% confidence interval (CI): 1.03-1.18), interbody fusion (aOR: 6.96; 95% CI: 2-24.18) and coagulase-negative staphylococci (CoNS) infection (aOR: 3.83; 95% CI: 1.01-14.53) remained independent risk factors for pVOM. Cases with pVOM had worse prognoses than those without (failure rate; 26.3% vs 10.8%; P = 0.038). Material removal was the preferred strategy (57.9%), mainly in early cases, without better outcomes (failure rate; 33.3% vs 50% compared with DAIR). Late cases managed with removal had greater success compared with DAIR (failure rate; 0% vs 40%; P = 0.067). CONCLUSION: Risk factors for pVOM are old age, use of interbody fusion devices and CoNS aetiology. Although the diagnosis leads to a worse prognosis, material withdrawn should be reserved for late cases or when spinal fusion is achieved.

Solar photocatalytic degradation of pesticides over TiO2-rGO nanocomposites at pilot plant scale.

Two TiO2-rGO nanocomposites were prepared by hydrothermal method from commercial TiO2 (P25 and Hombikat UV100, HBK). In both cases TiO2 nanoparticles appeared intimate and homogeneously distributed on rGO surface, but forming a dense network in P25-rGO nanocomposite, and a more open structure in HBK-rGO. Zeta potential and particle size distribution favored the ease of HBK-rGO nanocomposite to form stable suspensions. A comparative analysis of these two photocatalysts was performed on the pilot plant scale solar assisted photodegradation of a 200 µg·L-1 or 5 mg·L-1 mixture of persistent and biorecalcitrant pollutants in deionized water (methomyl, pyrimethanil, isoproturon and alachlor, all used as pesticides). Complete removal of pesticides was achieved, though faster with P25-rGO when O2 was the oxidant. However, the use of hydrogen peroxide (H2O2) dosage as oxidant speeded up pesticides removal, but HBK-rGO performance resulted much improved. Finally, at realistic very low concentrations of 200 µgeach pesticide·L-1, the complete removal of pesticides was achieved at very short times (<25 min), showing the efficiency of the synthetized TiO2-rGO nanocomposites in this pilot-plat scale solar process to mitigate refractory and biorecalcitrant contaminants on effluents as a sustainable and efficient process.

Suppressive antibiotic therapy in prosthetic joint infections: a multicentre cohort study.

OBJECTIVES: The aim was to describe the effectiveness of suppressive antibiotic treatment (SAT) in routine clinical practice when used in situations in which removal of a prosthetic implant is considered essential for the eradication of an infection, and it cannot be performed. METHODS: This was a descriptive retrospective and multicentre cohort study of prosthetic joint infection (PJI) cases managed with SAT. SAT was considered to have failed if a fistula appeared or persisted, if debridement was necessary, if the prosthesis was removed due to persistence of the infection or if uncontrolled symptoms were present. RESULTS: In total, 302 patients were analysed. Two hundred and three of these patients (67.2%) received monotherapy. The most commonly used drugs were tetracyclines (39.7% of patients) (120/302) and cotrimoxazole (35.4% of patients) (107/302). SAT was considered successful in 58.6% (177/302) of the patients (median time administered, 36.5 months; IQR 20.75-59.25). Infection was controlled in 50% of patients at 5 years according to Kaplan-Meier analysis. Resistance development was documented in 15 of 65 (23.1%) of the microbiologically documented cases. SAT failure was associated with age <70 years (sub-hazard ratio (SHR) 1.61, 95% CI 1.1-2.33), aetiology other than Gram-positive cocci (SHR 1.56, 95% CI 1.09-2.27) and location of the prosthesis in the upper limb (SHR 2.4, 95% CI 1.5-3.84). SAT suspension was necessary due to adverse effects in 17 of 302 patients (5.6%). CONCLUSIONS: SAT offers acceptable results for patients with PJI when surgical treatment is not performed or when it fails to eradicate the infection.

Lipid changes and tolerability in a cohort of adult HIV-infected patients who switched to rilpivirine/emtricitabine/tenofovir due to intolerance to previous combination ART: the PRO-STR study.

Objectives: To analyse lipid changes and tolerability in a cohort of HIV-infected patients who switched their antiretroviral regimens to rilpivirine/emtricitabine/tenofovir (RPV/FTC/TDF) in a real-world setting. Methods: PRO-STR is a 48 week prospective observational post-authorization study in 25 hospitals. Patients with a viral load <1000 copies/mL, receiving at least 12 months of combination ART (cART), with constant posology for at least the prior 3 months, were categorized according to previous treatment [NNRTI or ritonavir-boosted PI (PI/r)]. Analytical tests were performed at the baseline visit, between week 16 and week 32, and at week 48. Results: A total of 303 patients were included (mean age 46.6 years; male 74.0%; previous treatment 74.7% NNRTI and 25.3% PI/r). Both groups exhibited significantly reduced lipid profiles, except for HDL cholesterol, for which a non-significant increase was observed. [NNRTI patients: total cholesterol (baseline: 195.5 ±âŸ38.4 mg/dL; week 48: 171.0 ±âŸ35.5 mg/dL), total cholesterol/HDL ratio (baseline: 4.2 ±âŸ1.2; week 48: 4.0 ±âŸ1.2), HDL (baseline: 49.1 ±âŸ12.0 mg/dL; week 48: 49.2 ±âŸ45.8 mg/dL), LDL (baseline: 119.2 ±âŸ30.2 mg/dL; week 48: 114.2 ±âŸ110.7 mg/dL), and triglycerides (baseline: 136.6 ±âŸ86.8 mg/dL; week 48: 113.4 ±âŸ67.8 mg/dL); PI/r patients: total cholesterol (baseline: 203.2 ±âŸ48.8 mg/dL; week 48: 173.4 ±âŸ36.9 mg/dL), total cholesterol/HDL ratio (baseline: 4.7 ±âŸ1.6; week 48: 4.0 ±âŸ1.2), HDL (baseline: 46.4 ±âŸ12.5 mg/dL; week 48: 52.1 ±âŸ54.4 mg/dL), LDL (baseline: 127.0 ±âŸ36.3 mg/dL; week 48: 111.4 ±âŸ35.8 mg/dL), and triglycerides (baseline: 167.6 ±âŸ107.7 mg/dL; week 48: 122.7 ±âŸ72.1 mg/dL)]. The most common intolerances were neuropsychiatric in the NNRTI patients and gastrointestinal and metabolic in the PI/r patients, and these intolerances were significantly reduced in both groups at week 48 [NNRTI: neuropsychiatric (baseline: 81.3%; week 48: 0.0%); PI/r: gastrointestinal (baseline: 48.7%; week 48: 0.0%) and metabolic (baseline: 42.1%; week 48: 0.0%)]. Conclusions: RPV/FTC/TDF improved the lipid profiles and reduced the intolerances after switching from NNRTI or PI-based regimens, in a cohort of HIV-infected patients.

Sulfonamides photoassisted oxidation treatments catalyzed by ilmenite.

This work assesses the feasibility of several advanced oxidation processes (CWPO Catalytic Wet Peroxide Oxidation), Photocatalysis and their combination (CWPO-Photoassisted process) for sulfonamide antibiotic degradation. Raw ilmenite was used as catalyst in both processes, because of the presence of iron and titanium in its structure. Despite both treatments allowed reaching a total starting antibiotic depletion working at pH0 = 3 and T0 = 30 °C within 30 min reaction time, significant differences were observed in terms of mineralization. Thus, whereas photocatalytic process just reduced 35% of initial TOC after 120 min, a 85% of mineralization was reached in the presence of H2O2 (CWPO-Photoassisted process) which was related to the oxidation pathway. Only a 35% of mineralization was reached in case of CWPO. In this sense, the degradation route under CWPO-Photoassisted process displayed a mechanism based on the hydroxylation that led to lower molecular weight intermediates. On the contrary, under photocatalysis conditions, the appearance of higher molecular weight intermediates due to organic radical recombination indicates the prevailing of a condensation mechanism.

Solar-assisted photodegradation of isoproturon over easily recoverable titania catalysts.

An easily recoverable homemade TiO2 catalyst (GICA-1) has been evaluated during the overall photodegradation process, understood as photocatalytic efficiency and catalyst recovery step, in the solar light-assisted photodegradation of isoproturon and its reuse in two consecutive cycles. The global feasibility has been compared to the commercial TiO2 P25. The homemade GICA-1 catalyst presented better sedimentation efficiency than TiO2 P25 at all studied pHs, which could be explained by its higher average hydrodynamic particle size (3 µm) and other physicochemical surface properties. The evaluation of the overall process (isoproturon photo-oxidation + catalyst recovery) revealed GICA-1 homemade titania catalyst strengths: total removal of isoproturon in less than 60 min, easy recovery by sedimentation, and reusability in two consecutive cycles, without any loss of photocatalytic efficiency. Therefore, considering the whole photocatalytic cycle (good performance in photodegradation plus catalyst recovery step), the homemade GICA-1 photocatalyst resulted in more affordability than commercial TiO2 P25. Graphical abstract.

Time trends in the aetiology of prosthetic joint infections: a multicentre cohort study.

It is important to know the spectrum of the microbial aetiology of prosthetic joint infections (PJIs) to guide empiric treatment and establish antimicrobial prophylaxis in joint replacements. There are no available data based on large contemporary patient cohorts. We sought to characterize the causative pathogens of PJIs and to evaluate trends in the microbial aetiology. We hypothesized that the frequency of antimicrobial-resistant organisms in PJIs has increased in the recent years. We performed a cohort study in 19 hospitals in Spain, from 2003 to 2012. For each 2-year period (2003-2004 to 2011-2012), the incidence of microorganisms causing PJIs and multidrug-resistant bacteria was assessed. Temporal trends over the study period were evaluated. We included 2524 consecutive adult patients with a diagnosis of PJI. A microbiological diagnosis was obtained for 2288 cases (90.6%). Staphylococci were the most common cause of infection (1492, 65.2%). However, a statistically significant rising linear trend was observed for the proportion of infections caused by Gram-negative bacilli, mainly due to the increase in the last 2-year period (25% in 2003-2004, 33.3% in 2011-2012; p 0.024 for trend). No particular species contributed disproportionally to this overall increase. The percentage of multidrug-resistant bacteria PJIs increased from 9.3% in 2003-2004 to 15.8% in 2011-2012 (p 0.008), mainly because of the significant rise in multidrug-resistant Gram-negative bacilli (from 5.3% in 2003-2004 to 8.2% in 2011-2012; p 0.032). The observed trends have important implications for the management of PJIs and prophylaxis in joint replacements.

Characteristics of prosthetic joint infections due to Enterococcus sp. and predictors of failure: a multi-national study.

The objective of this study was to review the characteristics and outcome of prosthetic joint infections (PJI) due to Enterococcus sp. collected in 18 hospitals from six European countries. Patients with a PJI due to Enterococcus sp. diagnosed between January 1999 and July 2012 were retrospectively reviewed. Relevant information about demographics, comorbidity, clinical characteristics, microbiological data, surgical treatment and outcome was registered. Univariable and multivariable analyses were performed. A total of 203 patients met the inclusion criteria. The mean (SD) was 70.4 (13.6) years. In 59 patients the infection was diagnosed within the first 30 days (29.1%) from arthroplasty, in 44 (21.7%) between 31 and 90 days, in 54 (26.6%) between 91 days and 2 years and in 43 (21%) after 2 years. Enterococcus faecalis was isolated in 176 cases (89%). In 107 (54%) patients the infection was polymicrobial. Any comorbidity (OR 2.53, 95% CI 1.18-5.40, p 0.01), and fever (OR 2.65, 95% CI 1.23-5.69, p 0.01) were independently associated with failure. The only factor associated with remission was infections diagnosed later than 2 years (OR 0.25, 95% CI 0.09-0.71, p 0.009). In conclusion, prosthetic joint infections due to Enterococcus sp. were diagnosed within the first 2 years from arthroplasty in >70% of the patients, almost 50% had at least one comorbidity and infections were frequently polymicrobial (54%). The global failure rate was 44% and patients with comorbidities, fever, and diagnosed within the first 2 years from arthroplasty had a poor prognosis.

Gram-negative prosthetic joint infection: outcome of a debridement, antibiotics and implant retention approach. A large multicentre study.

We aim to evaluate the epidemiology and outcome of gram-negative prosthetic joint infection (GN-PJI) treated with debridement, antibiotics and implant retention (DAIR), identify factors predictive of failure, and determine the impact of ciprofloxacin use on prognosis. We performed a retrospective, multicentre, observational study of GN-PJI diagnosed from 2003 through to 2010 in 16 Spanish hospitals. We define failure as persistence or reappearance of the inflammatory joint signs during follow-up, leading to unplanned surgery or repeat debridement>30 days from the index surgery related death, or suppressive antimicrobial therapy. Parameters predicting failure were analysed with a Cox regression model. A total of 242 patients (33% men; median age 76 years, interquartile range (IQR) 68-81) with 242 episodes of GN-PJI were studied. The implants included 150 (62%) hip, 85 (35%) knee, five (2%) shoulder and two (1%) elbow prostheses. There were 189 (78%) acute infections. Causative microorganisms were Enterobacteriaceae in 78%, Pseudomonas spp. in 20%, and other gram-negative bacilli in 2%. Overall, 19% of isolates were ciprofloxacin resistant. DAIR was used in 174 (72%) cases, with an overall success rate of 68%, which increased to 79% after a median of 25 months' follow-up in ciprofloxacin-susceptible GN-PJIs treated with ciprofloxacin. Ciprofloxacin treatment exhibited an independent protective effect (adjusted hazard ratio (aHR) 0.23; 95% CI, 0.13-0.40; p<0.001), whereas chronic renal impairment predicted failure (aHR, 2.56; 95% CI, 1.14-5.77; p 0.0232). Our results confirm a 79% success rate in ciprofloxacin-susceptible GN-PJI treated with debridement, ciprofloxacin and implant retention. New therapeutic strategies are needed for ciprofloxacin-resistant PJI.

DFT calculations of 29Si-NMR chemical shifts in Ru(II) silyl complexes: searching for trends and accurate values.

The (29)Si chemical shifts in a series of closely related Ru(II) silyl complexes have been calculated by DFT methods and compared to the experimental values. The factors that lead to possible discrepancies between experimental and calculated values have been identified. It is shown that it is necessary to include the spin-orbit coupling associated with the relativistic effects of the heavy atoms for quantitative agreement with observed chemical shifts but trends are reasonably reproduced when the calculations do not include this correction. An NBO analysis of the NMR contributions from the bonds to Si and the Si core shows the greater importance of the former and a fine tuning originating from the latter.

Selectivity of hydrogen peroxide decomposition towards hydroxyl radicals in catalytic wet peroxide oxidation (CWPO) over Fe/AC catalysts.

Two Fe/AC catalysts prepared with different iron precursors (iron nitrate and iron pentacarbonyl) and the same AC support have been tested in H(2)O(2) decomposition in presence and absence of methanol, a known strong scavenger of hydroxyl radicals, to investigate the selectivity towards .OH formation in this reaction and their behavior in the CWPO of phenol. The catalyst prepared with iron nitrate, with the most oxidized surface and the highest Fe surface content, seems to favor a higher selectivity towards .OH formation in CWPO allowing for complete phenol conversion and a significant TOC removal, with the highest mineralization degree at 50 degrees C and atmospheric pressure. Fe/AC catalysts were more efficient in the CWPO of phenol than in methanol presence due to a better use of the oxidant since adsorbed phenol on catalyst surface minimizes inefficient H(2)O(2) decomposition to H(2)O and O(2)(g). The influence of the initial H(2)O(2) concentration on phenol oxidation with this catalyst was also studied. A theoretical stoichiometric amount of H(2)O(2) for complete oxidation of phenol was chosen as the best starting concentration since auto-scavenging reactions can be minimized and it is sufficient for oxidizing phenol and the aromatic intermediates.

[Analysis and predictor of delays in the suspicion and treatment among hospitalized patients with pulmonary tuberculosis]. / Análisis y factores predictores del retraso en la sospecha diagnóstica y tratamiento de los pacientes hospitalizados con tuberculosis pulmonar.

BACKGROUND AND OBJECTIVES: Sometimes tuberculosis diagnosis is missed at hospital admission. Delayed diagnosis of active pulmonary tuberculosis among hospitalized patients could to contribute to nosocomial transmission. The objective of this study was to define the occurrence and associated patient risk factors among hospitalized patients with delayed diagnosis of respiratory tuberculosis. METHODS AND PATIENTS: A retrospective chart review was undertaken between 1995 and 2002 on all patients with pulmonary tuberculosis. Time intervals between admission, diagnosis and treatment of tuberculosis were determined. Epidemiological and clinical features were evaluated for their effect on these time intervals. RESULTS: Among 149 patients newly diagnosed to have active pulmonary TB, the diagnosis was initially missed in 102 (68% [95% CI, 61 to 75%]) of all hospitalized patients, of whom 66 (65% [95% CI, 56 to 74%]) were smear positive. Treatment was initiated after a week or more in 62 (42% [95% CI, 34% to 50%]) of all patients, of whom 34 (55% [95% CI, 43 to 67%])) were smear positive. Age >or= 60 years (OR 3.17 [95% CI; 1.27 to 7.87]; p = 0.013), presence of chronic lung disease (OR 2.99 [95% CI; 1.21 to 7.38]; p = 0.017), negative sputum AFB smear (OR 4.51 [95% CI; 1.34 to 15.16]; p = 0.015) and absence of hemoptysis or melanoptysis (OR 2.96 [95% CI; 1.18 a 7.41]; p = 0.020), were independently associated with delays. CONCLUSIONS: The diagnosis and treatment of hospitalized patients with pulmonary tuberculosis is often delayed because absence of clinic suspicion owing to old age, chronic lung disease or atypical presentations and slow confirmation by culture. Improved clinical acumen, development of rapid diagnostic tests, and the institution of early empiric therapy are desirable objectives to improve the tuberculosis control.

Using machine learning procedures to ascertain the influence of beef carcass profiles on carcass conformation scores.

In this study, a total of 163 young-bull carcasses belonging to seven Spanish native beef cattle breeds showing substantial carcass variation were photographed in order to obtain digital assessments of carcass dimensions and profiles. This dataset was then analysed using machine learning (ML) methodologies to ascertain the influence of carcass profiles on the grade obtained using the SEUROP system. To achieve this goal, carcasses were obtained using the same standard feeding regime and classified homogeneous conditions in order to avoid non-linear behaviour in grading performance. Carcass weight affects grading to a large extent and the classification error obtained when this attribute was included in the training sets was consistently lower than when it was not. However, carcass profile information was considered non-relevant by the ML algorithm in earlier stages of the analysis. Furthermore, when carcass weight was taken into account, the ML algorithm used only easy-to-measure attributes to clone the classifiers decisions. Here we confirm the possibility of designing a more objective and easy-to-interpret system to classify the most common types of carcass in the territory of the EU using only a few single attributes that are easily obtained in an industrial environment.

Identifying market segments in beef: Breed, slaughter weight and ageing time implications.

In this paper we propose a method to learn the reasons why groups of consumers prefer some beef products to others. We emphasise the role of groups since, from a practical point of view, they may represent market segments that demand different products. Our method starts representing people's preferences in a metric space; there we are able to define a kernel based similarity function that allows a clustering algorithm to identify significant groups of consumers with homogeneous likes. Finally, in each cluster, we developed, with a support vector machine (SVM), a function that explains the preferences of those consumers grouped in the cluster. The method was applied to a real case of consumers of beef that tasted beef from seven Spanish breeds, slaughtered at two different weights and aged for three different ageing periods. Two different clusters of consumers were identified for acceptability and tenderness, but not for flavour. Those clusters ranked two very different breeds (Asturiana and Retinta) in opposite order. In acceptability, ageing period was appreciated in a different way. However, in tenderness most consumers preferred long ageing periods and heavier to lighter animals.

Artificial intelligence techniques point out differences in classification performance between light and standard bovine carcasses.

The validity of the official SEUROP bovine carcass classification to grade light carcasses by means of three well reputed Artificial Intelligence algorithms has been tested to assess possible differences in the behavior of the classifiers in affecting the repeatability of grading. We used two training sets consisting of 65 and 162 examples respectively of light and standard carcass classifications, including up to 28 different attributes describing carcass conformation. We found that the behavior of the classifiers is different when they are dealing with a light or a standard carcass. Classifiers follow SEUROP rules more rigorously when they grade standard carcasses using attributes characterizing carcass profiles and muscular development. However, when they grade light carcasses, they include attributes characterizing body size or skeletal development. A reconsideration of the SEUROP classification system for light carcasses may be recommended to clarify and standardize this specific beef market in the European Union. In addition, since conformation of light and standard carcasses can be considered different traits, this could affect sire evaluation programs to improve carcass conformation scores from data from markets presenting a great variety of ages and weights of slaughtered animals.

El test de Apgar una visión de la acción obstétrica: experiencia de 7 años / Apgar score a view point of the obstetric action: experience of 7 years

Se revisaron 382 fichas clínicas con Apgar bajo 7 ptos., a los 5 minutos de vida, de nuestra maternidad desde 1993 hasta 1999. Se investigó: incidencia, patologías asociadas y relación con variables no tradicionales. La incidencia de Apgar bajo 7 fue menor al 1 por ciento, excepto en 1999 (1,21 por ciento). El grupo de pacientes predominantes fue de 17-35 años (88,48 por ciento), siendo un 50,26 por ciento multípara. El 56,54 por ciento de RN eran pretérminos con peso inferior a 2.500 gramos (58,38 por ciento). La vida de parto principal fue vaginal (47,65 por ciento). La RPM representó la principal patología asociada (12,3 por ciento). Los diagnóstico pre y postnatal predominante fueron el trabajo de parto (54,45 por ciento) y la prematuridad (46,34 por ciento) respectivamente. Se encontró una relación directa con edad gestacional peso del RN. Esta investigación resalta la importancia del control prenatal para el diagnóstico precoz de patologías matemofetales, tomando conductas adecuadas para obtener un RN sano

Quiste pulmonar fetal: diagnóstico ultrasonográfico prenatal y manejo / Fetal pulmonary cyst: prenatal ultrasonography and management

Se presenta un caso clínico de un quiste pulmonar fetal diagnosticado por ultrasonografía a las 27 semanas de gestación. Se comenta la frecuencia, etiología, diagnóstico y tratamiento de esta rara malformación

Histerectomía obstétrica / Obstetric hysterectomy

Se analizan 52 casos de histerectomía obstétrica en la maternidad del Hospital Félix Bulnes Cerda ocurridas entre 1983 y 1998, obteniéndose una incidencia de 1 por cada 2283 partos ocurridos en ese período. Sus principales indicaciones son: la inercia uterina, adherencia placentaria anormal y el desprendimiento de placenta normoiserta (D.P.P.N.I.). La histerectomía fue subtotal en la mayoría de los casos (57,7 por ciento). Existe un alto porcentaje de pacientes multíparas con edades sobre los 30 años. Las complicaciones más frecuentes son: lesión de la vía urinaria, fiebre, hematoma y/o hemorragia de la neocúpula. La indicación de histerectomía obstetricia usada como recurso de salvataje debe ser criteriosa evitando causar mayor daño a la paciente, siempre entendiendo que la prevención y la optimización de las medidas coadyuvantes pueden hacer innecesaria la histerectomía

A prospective, randomized study comparing highly selective vagotomy and extended highly selective vagotomy in patients with duodenal ulcer.

The recurrence rate of duodenal ulcer after highly selective vagotomy is nearly 10 percent. To diminish this percentage, extended highly selective vagotomy with sectioning the gastroepiploic nerves has been proposed in order to reduce postoperative gastric acid secretion. We have prospectively compared the decrease in gastric acid secretion through measurement of basal acid output, maximal acid output, and peak acid output in patients who underwent highly selective vagotomy or extended highly selective vagotomy. No significant differences in postoperative gastric acid secretion were found and, therefore, no changes in the probability of postoperative recurrence of duodenal ulcer were seen.

A prospective study of intraoperative histologic antrum and corpus boundary in patients undergoing highly selective vagotomy for duodenal ulcer.

The results of the present study demonstrate that, at the level of the proximal branch of Crow's foot of Latarjet, parietal cells are found, and therefore, it must be sectioned when performing highly selective vagotomy. At the level of the distal branch, antral mucosa is found. At the level of the middle branch, in almost one-half of the instances, parietal cells are found, and its section must be evaluated with gastric emptying studies.