Shaping ability of BlueShaper, TruNatomy, DC Taper and HyFlex EDM in long oval canals: An ex vivo study.

AIM: This study evaluated and compared the shaping ability of four rotary instrument systems in long-oval root canals using microcomputed tomographic (micro-CT) evaluation. Currently, there is no data available on the canal shaping abilities of BlueShaper and DC Taper instruments. METHODOLOGY: Sixty-four single-rooted mandibular premolars were matched based on similar root canal morphologic features as determined by (micro-CT) and randomly assigned to 1 of 4 experimental groups (n = 16) according to the instrument system used: BlueShaper, TruNatomy, DC Taper and HyFlex EDM One File. Changes in the root canal surface and volume, remaining dentine thickness, and number of prepared areas were assessed. RESULTS: No significant differences were found amongst the four instrument systems for the parameters evaluated (p > .05). There was a significant reduction in the number of unprepared areas and the remaining dentine thickness after each increase in size of the instruments tested (p < .05). CONCLUSIONS: The four instrument systems perform similarly in long oval root canals. Although none could prepare all canal walls, larger preparations incorporated significantly more surfaces in the final shape.

TS-HDS and FGFR3 antibodies in small fiber neuropathy and Dysautonomia.

INTRODUCTION: The specificity of trisulfated heparin disaccharide/fibroblast growth factor receptor 3 (TS-HDS/FGFR3) antibodies in the diagnosis of autoimmune small fiber neuropathy (SFN) is unclear. METHODS: This was a retrospective study of patients evaluated for SFN and dysautonomia in the Brigham and Women's Faulkner Hospital Autonomic Laboratory in 2019-2020. Associations were assessed between TS-HDS/FGFR3 antibodies and SFN markers, including epidermal nerve fiber density (ENFD), sweat gland nerve fiber density (SGNFD), and autonomic dysfunction assessed by Valsalva maneuver, deep breathing, sudomotor, and tilt testing. RESULTS: Of 322 patients; 28% had elevated anti-TS-HDS, 17% had elevated anti-FGFR3, 96% had autonomic dysfunction, 71% had abnormal ENFD, and 49% had abnormal SGNFD. TS-HDS/FGFR3 antibodies were present in patients with autonomic dysfunction irrespective of whether they had normal or abnormal skin biopsies unless ENFD/SGNFD were combined for anti-FGFR3 seropositivity. DISCUSSION: TS-HDS/FGFR3 antibodies are present in patients with evidence of autonomic dysfunction. Further studies are needed to document the clinical value of these antibodies in assessment of immune mediated dysautonomia.

A local representation of the head-related transfer function.

Spatial descriptions of the head-related transfer function (HRTF) using spherical harmonics, which is commonly used for the purpose, consider all directions simultaneously. However, in perceptual studies, it is necessary to model HRTFs with different angular resolutions at different directions. To this end, an alternative spatial representation of the HRTF, based on local analysis functions, is introduced. The proposal is shown to have the potential to describe the local features of the HRTF. This is verified by comparing the reconstruction error achieved by the proposal to that of the spherical harmonic decomposition when reconstructing the HRTF inside a spherical cap.

Changes in T-Tubules and Sarcoplasmic Reticulum in Ventricular Myocytes in Early Cardiac Hypertrophy in a Pressure Overload Rat Model.

BACKGROUND/AIMS: Pressure-overload (PO) causes cardiac hypertrophy (CH), and eventually leads to heart failure (HF). HF ventricular myocytes present transverse-tubules (TT) loss or disarrangement and decreased sarcoplasmic reticulum (SR) density, and both contribute to altered Ca2+ signaling and heart dysfunction. It has been shown that TT remodeling precedes HF, however, it is unknown whether SR structural and functional remodeling also starts early in CH. METHODS: Using confocal microscopy, we assessed TT (with Di-8-ANNEPS) and SR (with SR-trapped Mag-Fluo-4) densities, as well as SR fluorophore diffusion (fluorescence recovery after photobleach; FRAP), cytosolic Ca2+ signaling and ex vivo cardiac performance in a PO rat hypertrophy model induced by abdominal aortic constriction (at 6 weeks). RESULTS: Rats developed CH, while cardiac performance, basal and upon ß-adrenergic stimulation, remained unaltered. TT density decreased by ∼14%, without spatial disarrangement, while SR density decreased by ∼7%. More important, FRAP was ∼30% slower, but with similar maximum recovery, suggesting decreased SR interconnectivity. Systolic and diastolic Ca2+ signaling and SR Ca2+ content were unaltered. CONCLUSION: SR remodeling is an early CH event, similar to TT remodeling, appearing during compensated hypertrophy. Nevertheless, myocytes can withstand those moderate structural changes in SR and TT, preserving normal Ca2+ signaling and contractility.

An in vitro evaluation of endodontic sealers and an antibiotic to assess their antimicrobial effect against Enterococcus faecalis.

Objective: This study aimed to compare the antimicrobial effect of three endodontic sealers (AH Plus, Mineral trioxide aggregate [MTA] Fillapex, and BioRoot RCS) with and without amoxicillin against E. faecalis. Methodology: Amoxicillin, equivalent to 10% of the sealers' total weight, was mixed with the sealers. Another batch was prepared without amoxicillin. The direct contact test (DCT) and the agar diffusion test were used to assess the antibacterial effect. Results were analysed using one-way analysis of variance (ANOVA), the F-test, and the Kruskal-Wallis test. Results: AH Plus significantly suppressed E. faecalis without the addition of amoxicillin in the DCT (p = 0.011), while in the agar diffusion test, BioRoot RCS had a larger inhibition zone than the control (p < 0.001). When amoxicillin was added to the sealers, AH Plus (p = 0.003) and MTA Fillapex (p = 0.042) reduced E. faecalis growth. In contrast, all three sealers showed larger inhibition zones than the control (p = 0.001), with AH Plus displaying a larger inhibition zone than MTA Fillapex (p = 0.042) and BioRoot RCS (p = 0.032). Conclusions: It was thus concluded that the addition of amoxicillin to endodontic sealers enhances their antimicrobial activity against E. faecalis.

Depressive symptoms exacerbate disability in older adults: A prospective cohort analysis of participants in the MemAID trial.

BACKGROUND: Maintaining independence in older age is an important aspect of quality of life. We investigated depressive symptoms as an important modifiable risk factor that may mediate the effects of physical and cognitive decline on disability. METHODS: We prospectively analyzed data from 223 adults (age 50-85; 117 controls and 106 with type-2 diabetes) over 48 weeks who were participating in a clinical trial "Memory Advancement by Intranasal Insulin in Type 2 Diabetes." Data from self-reported disability (World Health Organization Disability Assessment Schedule) and depressive symptoms (Geriatric Depression Scale) were obtained from baseline, week 25, and week 48 visits. Cognition (Mini-mental status examination) and medical comorbidities (Charlson Comorbidity Index) were assessed at baseline. Longitudinal analysis assessed the extent to which change in depressive symptoms predicted worsening disability. Mediation analyses were performed to determine the extent to which depressive symptoms accounted for disability associated with worse cognition, walking speed, and comorbidities. RESULTS: At baseline, depressive symptoms, cognition, and walking speed were within normal limits, but participants had a high 10-year risk of cardiovascular mortality. Depressive symptoms were related to disability at baseline (p<0.001), and longitudinally (p<0.001). Cognition, walking speed, and comorbidities were associated with disability at baseline (p-values = 0.027-0.001). Depressive symptoms had a large mediating effect on disability longitudinally: the indirect effect on disability via depression accounts for 51% of the effect of cognition, 34% of the effect of mobility, and 24% of the effect of comorbidities. CONCLUSIONS: Depressive symptoms substantially exacerbated the effects of worsening cognition, gait speed, and comorbidities on disability. In our sample, most individuals scored within the "normal" range of the Geriatric Depression Scale, suggesting that even subclinical symptoms can lead to disability. Treating subclinical depression, which may be under-recognized in older adults, should be a public health priority to help preserve independence with aging.

Antimicrobial effectiveness of root canal sealers against Enterococcus faecalis.

We evaluated four root canal sealers to determine their antimicrobial effectiveness against E. faecalis. The direct contact test was used to measure the effectiveness of the study materials and close contact between bacteria on the kinetics of bacterial growth. The agar diffusion test (ADT) was also performed for comparison. Using one-way ANOVA and the F-test, significant differences between the sealers were confirmed. Whereas BioRoot endodontic sealer had an antimicrobial effect statistically similar to the zinc oxide-eugenol control (p=.99), EndoSequence sealer and AH Plus sealer both had a significantly lower antimicrobial effect than the control (p=.0000266 and p=.0000068, respectively).

Antimicrobial potential of AH Plus supplemented with bismuth lipophilic nanoparticles on E. faecalis isolated from clinical isolates.

The objective of this study was to determine the antimicrobial potential of AH plus supplemented with bismuth lipophilic nanoparticles (BisBAL NPs) on the growth of Enterococcus faecalis isolated from patients with endodontic infections. BisBAL NPs, synthesized with the colloidal method, were characterized, in its pure form or AH Plus-absorbed, by energy-dispersive X-ray spectroscopy and scanning electron microscopy (EDS-SEM). Antimicrobial activity was evaluated with disc diffusion assays, and antibiofilm activity with fluorescence microscopy. BisBAL NP-supplemented AH Plus had a 4.9 times higher antimicrobial activity than AH Plus alone (p = 0.0001). In contrast to AH Plus alone, AH Plus supplemented with BisBAL NP inhibited E. faecalis biofilm formation. The sealing properties of AH plus were not modified by the incorporation of BisBAL NPs, which was demonstrated by a 12-day split-chamber leakage assay with daily inoculation, which was used to evaluate the possible filtration of E. faecalis. Finally, BisBAL NP-supplemented AH plus-BisBAL NPs was not cytotoxic for cultured human gingival fibroblasts. Their viability was 83.7% to 89.9% after a 24-h exposure to AH Plus containing 50 and 10 µM BisBAL NP, respectively. In conclusion, BisBAL NP-supplemented AH Plus constitutes an innovative nanomaterial to prevent re-infection in endodontic patients without cytotoxic effects.

In Vivo Evaluation of 3 Electronic Apex Locators: Root ZX Mini, Apex ID, and Propex Pixi.

INTRODUCTION: The aim of this in vivo study was to compare the accuracy of 3 electronic apex locators (EALs) (Root ZX mini [J Morita Corp, Tokyo, Japan], Apex ID [SybronEndo, Glendora, CA], and Propex Pixi [Dentsply Maillefer, Ballaigues, Switzerland]) to determine the working length. METHODS: Thirty single-rooted human teeth that were scheduled for extraction were selected for the study. Electronic measurements were performed with the 3 EALs. After the teeth had been extracted, a #10 K-file was used to determine the actual working length, which was established at 0.5 mm short of the major foramen. The data were statistically analyzed with analysis of variance (α = 0.05). RESULTS: No significant differences were found among the experimental groups (P > .05). The mean distance from the actual working length to the file tip was 0.163 ± 0.032 mm when Root ZX mini was used, 0.343 ± 0.032 mm for Propex Pixi , and 0.012 ± 0.008 mm for Apex ID. CONCLUSIONS: Under the in vivo conditions of this study, no statistically significant differences were observed among the 3 EALs.

The use of porcine small intestinal submucosa as a prosthetic material for laparoscopic hernia repair in infected and potentially contaminated fields: long-term follow-up.

INTRODUCTION: The treatment of hernias remains controversial, with multiple prosthetic meshes being exalted for a variety of their characteristics. In the event of incarcerated/strangulated hernias and other potentially contaminated fields the placement of prosthetic material remains controversial because of increased risk of recurrence and infection. Porcine small intestinal submucosa mesh (Surgisis, Cook Bloomington, IN) has been demonstrated safe and feasible in laparoscopic hernia repairs in this scenario. We present our 5-year experience, with placement of Surgisis mesh in potentially or grossly contaminated fields. METHODS: From May 2000 to October 2006, 116 patients (52 male, 64 female) with 133 procedures were performed. Placement of Surgisis mesh for either incisional, umbilical, inguinal, femoral or parastomal hernia repairs in an infected or potentially contaminated setting were achieved, and studied in a prospective fashion. RESULTS: All procedures were laparoscopically with two techniques [intraperitoneal onlay mesh (IPOM) and two-layered "sandwich" repair]. Mean follow-up was 52 +/- 20.9 months. Thirty-nine cases were in an infected field and the rest in a potentially contaminated field. Ninety-one procedures were performed concurrently with a contaminated procedure. Twenty-five presented as intestinal obstruction, 16 strangulated hernias, and 17 required small bowel resection; 29 were inguinal hernias, 57 incisional, and 38 umbilical. In 13 patients more than two different hernias were repaired. Eighty-five percent 5-year follow-up was achieved, during which we identified 7 recurrences, 11 seromas (all resolved), and 10 patients reporting mild pain. Six second looks were performed and in all cases except one the mesh was found to be totally integrated into the tissue with strong scar tissue corroborated macro- and microscopically. CONCLUSIONS: In our experience the use of small intestine submucosa mesh in contaminated or potentially contaminated fields is a safe and feasible alternative to hernia repair with minimal recurrence rate and satisfactory results in long-term follow-up.

Apexification in a mandibular first molar with a middle mesial canal.

Apexification procedures have been widely used to treat teeth with incomplete root development and pulp necrosis. The middle mesial canal (MMC) is an anatomical variation and in most cases represents a challenge during endodontic treatments. In this article, a favorable outcome is reported after apexification in a molar with MMC.

3D Imaging Detection of HER2 Based in the Use of Novel Affibody-Quantum Dots Probes and Ratiometric Analysis.

Patients with breast cancer (BC) overexpressing HER2 (HER2+) are selected for Trastuzumab treatment, which blocks HER2 and improves cancer prognosis. However, HER2+ diagnosis, by the gold standard, immunohistochemistry, could lead to errors, associated to: a) variability in sample manipulation (thin 2D sections), b) use of subjective algorithms, and c) heterogeneity of HER2 expression within the tissue. Therefore, we explored HER2 3D detection by multiplexed imaging of Affibody-Quantum Dots conjugates (Aff-QD), ratiometric analysis (RMAFI) and thresholding, using BC multicellular tumor spheroids (BC-MTS) (~120 µm of diameter) as 3D model of BC. HER2+, HER2- and hybrid HER2+/- BC-MTS (mimicking heterogeneous tissue) were incubated simultaneously with two Aff-QD probes (anti-HER2 and negative control (NC), respectively, (1:1)). Confocal XY sections were recorded along the Z distance, and processed by automatized RMAFI (anti-HER2 Aff-QD/ NC). Quantifying the NC fluorescence allowed to predict the fraction of non-specific accumulation of the anti-HER2 probe within the thick sample, and resolve the specific HER2 level. HER2 was detected up to 30µm within intact BC-MTS, however, permeabilization improved detection up to 70µm. Specific HER2 signal was objectively quantified, and HER2 3D-density of 9.2, 48.3 and 30.8% were obtained in HER2-, HER2+ and hybrid HER2+/- permeabilized BC-MTS, respectively. Therefore, by combining the multiplexing capacity of Aff-QD probes and RMAFI, we overcame the challenge of non-specific probe accumulation in 3D samples with minimal processing, yielding a fast, specific spatial HER2 detection and objective quantification.

[Laparoscopic subtotal colectomy. Results from the Texas Endosurgery Institute]. / Colectomía Subtotal Laparoscópica. Resultados en el Texas Endosurgery Institute.

BACKGROUND: Laparoscopy is currently and progressively gaining acceptance for the management of colorectal disease. More bleeding and longer operating time were initially considered as contraindications to perform laparoscopic colon resections. Other obstacles were technical difficulties, the learning curve and the need for specialized instruments; however, improvements in surgical techniques and technological developments have allowed subtotal laparoscopic colectomy to be feasible. METHODS: This was a retrospective and descriptive study conducted from April 1992 to July 2006. Forty-four patients underwent laparoscopic subtotal colectomy at Texas Endosurgery Institute in San Antonio, TX. Measured variables to evaluate efficacy and safety were operating time, length of hospital stay, time to resume normal diet, conversion to open procedure, morbidity and mortality. RESULTS: Cancer, familial adenomatous polyposis and ulcerative colitis were the main surgical indications. The procedure was technically successful in 88% of patients. There were five conversions (11.3%). Mean operating time was 210 min. Morbidity and mortality rates were 29% and 2.2%, respectively. Mean length of hospital stay and time to resume normal diet were 11 and 4 days, respectively. CONCLUSIONS: Laparoscopic subtotal colectomy in our institute may be considered as an effective and safe method in the management of colorectal disease.

Clinical laboratories, the select agent program, and biological surety (biosurety).

The threat of bioterrorism has led to increased concerns over the availability of biological select agents and toxins (BSAT). Congress has implemented several public laws that have led to the development of federal regulations by the Centers for Disease Control and Prevention (CDC) and the US Department of Agriculture. The CDC regulation 42 CFR 73 has a direct impact on all clinical laboratories that may at some time identify BSAT in a clinical specimen. The Department of Defense has imposed a more stringent layer of regulation called biological surety (biosurety) on top of the requirements of 42 CFR 73 for military laboratories that possess BSAT. However,42 CFR 73 falls into the framework of biosurety. Both sets of regulations have four pillars (safety, physical security, agent account-ability, and personnel reliability) that are built on a foundation of training and covered by a roof of management (operations and plans).

The use of bioabsorbable staple line reinforcement for circular stapler (BSG "Seamguard") in colorectal surgery: initial experience.

Of all the complications associated with colorectal surgery, the most devastating and constant, despite all techniques being performed properly is anastomotic leakage, especially in left colon and rectal resections with rates as high as 50% when the rectum is involved. In 2005, our center published the preliminary experience with the use of linear staple line reinforcement for colon surgery. The purpose of this paper is to present a series of cases using a new conformation of bioabsorbable reinforcement for circular staplers in 5 patients, 2 patients with rectal cancer, 2 patients with diverticular disease, and 1 patient with sigmoid cancer. These initial data are very promising and has encouraged us to continue using this device on further patients.

Bedside diagnostic laparoscopy in the intensive care unit: a 13-year experience.

BACKGROUND: Frequently, critically ill patients suffer from intraabdominal pathology, such as sepsis or ischemia, either as a cause of a critical illness or as a complication from another illness requiring an intensive care unit (ICU) admission. These complications are associated with high rates of morbidity and mortality (between 50% to 100%). The diagnosis of these problems can be difficult in these very ill patients because it may require transport of unstable patients to additional departments outside the ICU setting. One option in the diagnosis of these difficult patients is bedside laparoscopy, as it avoids patient transport, is very accurate, and maintains ICU monitoring. METHODS: From 1991 to 2003, 13 patients underwent bedside diagnostic laparoscopy in the ICU to diagnose intraabdominal pathology in critically ill patients. All the procedures were done at the bedside in the ICU with the patient under local anesthesia and intravenous sedation. RESULTS: Mean procedure time was 36 minutes (range, 17 to 55). Mean patient age was 75.5 years (range, 56 to 86). There were 8 males and 5 females. Forty-six percent of the patients were diagnosed with mesenteric necrosis and died within 48 hours with no further testing or procedures. One patient with massive fecal contamination died the same day. Thirty percent of patients had a normal intraabdominal examination; of these, 2 died of unrelated illnesses and 2 survived their nonabdominal illness. Fifteen percent were diagnosed with acute acalculous cholecystitis as a complication of their ICU illness, which resolved satisfactorily. No intraoperative complications occurred with the ICU procedure. CONCLUSION: Bedside diagnostic laparoscopy in the ICU is feasible, safe, and accurate in the assessment of possible intraabdominal problems in properly selected, critically ill patients.

Intraluminal approach for resection of a gastric ulcer: a case report.

Laparoscopy, both diagnostic and therapeutic, has been used in the management of gastric pathology because of all the benefits of a minimally invasive procedure, such as faster recovery, shorter hospital stay, fewer wound complications, and other benefits. We report a case involving the resection of a gastric ulcer in a 71-year-old patient. Endoscopy revealed a nonhealing antral ulcer that was not acutely bleeding. With a combined endoscopic and laparoscopic approach, we successfully performed a wide resection by using 2-mm instruments. Laparoscopy was needed to orient the lesion so that a transgastric intraluminal resection could be performed with 2-mm instruments. This case illustrates the feasibility of using a combined endoscopic and laparoscopic technique to treat a lesion that would otherwise require a formal resection.

Needlescopic cholecystectomy: lessons learned in 10 years of experience.

OBJECTIVES: Needlescopic cholecystectomy (NC) is a refinement of laparoscopic cholecystectomy (LC) using 2-mm instruments compared with the standard 5-mm and 10-mm ports. We review our experience with needlescopic cholecystectomy. METHODS: From 1994 to 2004, 303 patients underwent NC. All patients were operated on using 2-mm instruments and one 10-mm trocar for the laparoscope. The characteristics of patients, total operation time, complications, postoperative pain, and hospital course were documented. RESULTS: Patients' average age was 41.86 years; 262 were female and 41 were male. Mean BMI was 25.7. Mean length of surgery was 59.33 minutes. Intraoperative cholangiography was performed in all cases. Mean blood loss was 14.88 mL. One intraoperative complication occurred. Mean hospital stay was 22.68 hours. Postoperative pain was measured on a 0-10 pain scale; on day 0 it was 4.4 and on the first day it was 1.7. Analgesic doses required were 0 doses in 6.89%, 1 in 20.68%, 2 in 24.13%, 3 in 34.48%, 4 in 13.79%, and > 4 doses was not required. No postoperative complications occurred. At 3-month follow-up, patient satisfaction was 100%, and in 99% of patients scars were imperceptible. CONCLUSIONS: NC is safe and feasible without increased operative risk, with better cosmetic results, less pain, and good acceptance among patients.

[Laparoscopic splenectomy: Twelve-year experience in two private institutions]. / Esplenectomía laparoscópica. Experiencia de 12 años en dos instituciones privadas.

BACKGROUND: In 1991, Delaitre et al. reported the first successful laparoscopic splenectomy. This procedure has become the best option in patients with hematological diseases and who require surgical treatment. The potential advantages of the laparoscopic approach over the conventional surgery are shorter length of hospital stay, shorter time to resume normal diet and decreased rates of morbidity and mortality. METHODS: From June 1993 to December 2004, 42 patients underwent laparoscopic splenectomy in our two surgical care centers: Texas Endosurgery Institute and Hospital San José-TEC de Monterrey. The measured variables to evaluate efficacy and safety were operating time, length of hospital stay, time to resume normal diet, conversion to open procedure, morbidity and mortality. RESULTS: Hematological diseases were the most common diagnosis. The procedure was technically successful in 95% of the patients. There were two conversions to open surgery. The mean operating time was 120 min. Mortality rate was 2.3%. The mean length of hospital stay and time to resume normal diet were 4 and 2 days, respectively. CONCLUSIONS: We regard that our series contributes to supporting laparoscopic splenectomy as a safe and effective method, retaining some advantages of minimally invasive techniques.

Evaluación de calidad en los servicios de salud: un análisis desde la percepción del usuario / Evaluation of health care services quality: An analysis from the user's perception

Resumen Objetivo: Analizar los determinantes de la evaluación en la calidad de los servicios de salud públicos y privados usando como caso de estudio el Área Metropolitana de Monterrey (AMM). Material y métodos: A partir de un estudio cuantitativo-exploratorio que utiliza la información del estudio de percepción ciudadana "Así Vamos 2018" y cuyo diseño permite la representatividad a nivel estatal, municipal y por género en la población objetivo, se utilizan dos métodos estadísticos (análisis factorial y modelo de regresión Tobit) para identificar cuales características son valoradas en la percepción de calidad para cada servicio de salud, distinguiendo entre instituciones públicas y privadas. Posteriormente, se analiza como las variables de servicio que determinan esta evaluación de calidad. Resultados: Las estimaciones sugieren diferencias significativas de los determinantes de calidad entre distintos servicios de salud: mientras para los usuarios del IMSS lo más importante es la "características de las instalaciones", "horarios de servicio" y preponderantemente "acceso a medicinas", para usuarios del Seguro Popular y servicios privados es la "atención del personal administrativo". Conclusión: Los usuarios utilizan diferentes criterios para evaluar las alternativas de servicios de salud a las que tienen acceso, y por tanto esta discrepancia es fundamental al comparar la calidad ofrecida por diferentes oferentes.

Abstract Objective: This paper studies the determinants of the quality assessment of public and private health services using the Monterrey Metropolitan Area (AMM) as a case study Material and Methods: This is a quantitative-exploratory study that uses the information from the citizen perspective study "Asi Vamos 2018" and whose design allows representativeness at the state, municipal, and gender levels in the relevant population, two statistical methods are used (factor analysis and a Tobit regression model) to identify which characteristics are valued in the perception of quality for each health service, distinguishing between public and private institutions. Subsequently, it is analyzed how service variables determine this quality evaluation. Results: The estimations suggest significant differences in the determinants of quality between health services: while for IMSS users the most important characteristics evaluated are the quality of installations, "access to more dates for medical attention", and "access to medicines" for Seguro Popular and private services users it is the "hospital managerial personnel attitude". Conclusion: Users apply different criteria to evaluate the alternatives on health service to which they have access, and therefore this discrepancy is fundamental when comparing the quality offered by different suppliers.