Volatilome Analysis of Soursop Fruits for the Determination of Kairomone Components That Attract the Annonaceae Fruit Weevil (Optatus palmaris Pascoe).

Soursop possesses the largest fruit size of the Annona genus. However, this species is threatened by the Annonaceae fruit weevil (Optatus palmaris), which can cause the destruction of whole soursop fruits. Recently, the potential of semiochemicals for the management of this insect is highlighted, and its aggregation pheromone has been elucidated. This pheromone works well only when mixed with soursop volatiles. Thus, the aim of this research was to determine specific kairomone components to potentiate the aggregation pheromone of this Annonaceae fruit weevil. This task was carried out via volatilome analysis of soursop fruits, which was correlated with the biological activity of the identified volatiles. The GC-MS analysis of aroma collections of mature soursop fruits and flowers, determined using multivariate data analysis, confirmed a volatile differentiation between these organs. The volatile variation between fruits and flowers was reflected in weevils' preference for mature fruits instead of flowers. Moreover, weevils' response to soursop fruits increased with more mature fruits. This was correlated with volatile changes throughout the phenological stages of soursop fruits. The two volatiles most correlated with weevils' attraction were benzothiazole and (E)-ß-caryophyllene. These volatiles only evoked a response when mixed and potentiated the attraction of the aggregation pheromone. Thus, these two volatiles are active kairomone components with the potential for being used in combination with the aggregation pheromone of Annonaceae fruit weevils in field trials.

Intraocular pressure fluctuations in patients implanted with an implantable collamer lens (ICL V4c). Three-month follow-up. / Fluctuaciones de presión intraocular en pacientes operados con implante de implantable collamer lens (ICL V4c). Seguimiento a 3 meses.

INTRODUCTION: Fluctuating elevated intraocular pressure (IOP) is one of the complications of an implantable collamer lens (ICL), and its alteration is a predictive factor for the development of glaucoma. MATERIAL AND METHODS: A prospective, cross-sectional analytic study was conducted on patients suitable for ICL implantation. Complete clinical and biometric work-ups were performed, as well as night-time IOP curve, in supine position, with 4 determinations, in order to assess fluctuation, considering abnormal with a value higher than 5 mmHg. Patients underwent surgery with conventional technique and three months after the work-ups were repeated, including a night-time IOP curve to assess any changes in IOP fluctuations. RESULTS: A total of 31 eyes of 16 patients were studied. Mean IOP fluctuation in the preoperative assessment was 3.35 ± 2 mmHg, whereas the postoperative mean was 3.0 ± 2.2 mmHg, with the difference not being statistically significant. Visual acuity and capacity, as well as spheric equivalent did show a statistically significant improvement. There were 6 cases of complications, which were related to a higher vault and a greater ICL size. There was no relationship between these findings and the angle grade, pigment, and the level of training of the surgeon. CONCLUSIONS: The effect of an ICL on IOP fluctuations, has been studied for the first time, which was found to be not statistically significant. As in previous publications, the procedure was safe and reproducible, adding the fact that the level of training of the surgeon is not a determining factor in these findings.

Comparison of Goldmann applanation and dynamic contour tonometry in a population of Mexican open-angle glaucoma patients.

To compare intraocular pressure (IOP) measurements obtained with Goldmann applanation (GAT) and dynamic contour tonometry (DCT) in a Mexican population. 40 glaucoma patients were included in this cross-sectional observational cohort study. IOP measurements were performed in the following order: DCT, ultrasonic pachymetry and GAT, with a 5-minute difference between each measurement, between 8 am and 2 pm. Only DCT measurements of good quality (Q ≤ 3) were accepted. GAT measurements were made three times with the same Goldmann tonometer, previously checked for calibration errors, and the mean was used for statistical purposes. The IOP (mean [standard deviation], 95 % confidence interval [CI]) measured with the Goldmann tonometer (13.2 [2.4], 12.4-14.0 mmHg) was significantly lower than that obtained with the DCT (18.4 [3.3], 17.0-19.2 mmHg), p < 0.0001. Pearson's correlation coefficients between CCT and IOP measured with GAT and DCT were (r = 0.24, 95 % CI = 0.07-0.52, p = 0.133) and (r = 0.13, 95 % CI = -0.19 to 0.43, p = 0.412), respectively. The concordance correlation coefficient between GAT and DCT was r c = 0.3, 95 % CI = 0.17-0.41). DCT seems to overestimate the IOP as compared to GAT. Additionally, although there was a good correlation between the IOP measurements assessed with either GAT or DCT, the agreement was poor.

Predicción de unión de péptidos de Plasmodium falciparum al HLA clase II. Probabilidad, combinatoria y entropía aplicadas a las proteínas MSP-5 y MSP-6 / Plasmodium falciparum binding peptides prediction to HLA class II. Probability, combinatory and entropy applied to MSP-5 and MSP-6 proteins

Las proteínas de superficie del merozoíto (MSP) son de importancia en la invasión parasitaria al glóbulo rojo. La proteína MSP-5, encontrada en merozoítos libres, tiene un papel en la inmunización de ratones al P. falciparum y P. yoelii, pese a lo cual algunos estudios cuestionan su rol en la invasión. La proteína MSP-6 forma junto con MSP-1 y MSP-7 un complejo en la superficie del merozoíto, liberado del parásito cerca del momento de la invasión al glóbulo rojo. Con el fin de predecir el fenómeno de unión de péptidos de las proteínas de superficie MSP-5 y MSP-6, se aplicó una teoría de unión al HLA clase II, a la totalidad de secuencias de 20 aminoácidos de tales moléculas. Se calcularon los valores de probabilidad, combinatoria y entropía de 168 secuencias nonámeras sobrelapadas de la proteína MSP-5 y 228 de MSP-6. Por último se aplicó la teoría de unión a todos los péptidos nonámeros de tres proteínas construidas computacionalmente, cada una con una longitud de 500 aminoácidos. Para la proteína MSP-5 se predijo un total de 31 secuencias asociadas al macroestado de unión y 137 al de no unión, mientras que se predijo la existencia de 35 secuencias asociadas al macroestado de unión para MSP-6 y 193 al de no unión. Se encontraron respectivamente 100, 111 y 91 secuencias predichas de unión para las tres proteínas teóricas construidas. La predicción teórica de unión de péptidos es útil para facilitar el desarrollo de vacunas, al evidenciar el orden físico-matemático subyacente al fenómeno.(AU)

Trastornos de coagulación en trauma craneoencefálico / Coagulation disorders in cranioencephalic trauma

La comprensión del proceso de la coagulación ha progresado durante la última década, evolucionando a partir del concepto según el cual la producción del coágulo se iniciaba por acción de las plaquetas y la activación de uno de los dos sistemas separados, la vía extrínseca y la vía intrínseca, al concepto actual que hace énfasis sobre la vía común y un sistema proteolítico que da lugar a la degradación de los coágulos formados y a la prevención de la formación indeseada de coágulos. La alteración de este equilibrio cobra especial importancia en los pacientes con trauma craneoencefálico, en quienes -a la luz de los conocimientos actuales- se pueden presentar trastornos de la coagulación que van desde lesiones procoagulantes, en un extremo, hasta lesiones anticoagulantes, en el otro extremo. La meta de los autores es brindar a los clínicos de una guía de evaluación inicial, de seguimiento y, de las posibilidades terapéuticas disponibles en el momento.

The understanding of the coagulation process has progressed during last decade evolving from the concept according to which the production of the clot begins by means of the action of platelets and the activation of one of two separated systems, the extrinsic route and the intrinsic route, to the present concept that makes emphasis on the common route and a proteolytic system that give rise to the degradation of formed clots and to the undesired prevention of the formation of the clot. The alteration of this balance receives special importance in the patients with brain trauma in those who to the light of the present knowledge may present upheavals of the coagulation which can go from procoagulating injuries in one end to anticoagulating injuries in the other. The goal of the authors is to provide a clinical guide with initial evaluation, pursuit and therapeutic possibiliti.es available at the moment.

Pancreatic neuroendocrine tumours.

INTRODUCTION: Pancreatic neuroendocrine tumours (PNT) are infrequent epithelial neoplasms associated with a better outcome than pancreatic adenocarcinoma. MATERIALS AND METHODS: We analysed our 22 years of experience in managing PNT. Forty-nine patients (27 women and 22 men) with a mean age of 49 years were studied. There were 28 insulinomas, eight glucagonomas, three gastrinomas, one VIPoma and one carcinoid. Eight patients presented with nonfunctional tumours. Enucleation was performed in 20 patients, distal pancreatectomy in 16, middle pancreatic resection in four, cephalic pancreatoduodenectomy in two and total pancreatoduodenectomy in one. In six patients, the tumour was not resected. RESULTS: Postoperative complication rate was 22%: six pancreatic fistulas, three intra-abdominal collections, one remnant pancreatitis and one pancreatic pseudocyst. There was no mortality. 39 cases showed benign histologic features and ten malignant ones. Symptomatic palliation was achieved in 94% of the cases. Five patients presented recurrences: three liver metastases and two pancreatic recurrences. Actuarial mean survival was 163 months and was longer in insulinomas, in those tumours completely resected and in tumours with benign histological features. CONCLUSION: Conservative surgery of the pancreas is preferred, but aggressive surgery is indicated when the primary tumour can be controlled. Despite of minimising pancreatic resection, there is a high complication rate, mainly pancreatic fistulas, though they can often be conservatively managed. Insulinomas are the PNT with better outcome; those completely resected also associate a better prognosis.

Pseudomyxoma peritonei secondary to epithelial appendicular neoplasms. Experience in a non-specialised centre.

INTRODUCTION: Pseudomyxoma peritonei is an infrequent entity, defined by collections of gelatinous material in the abdomen and pelvis and mucinous implants on peritoneum, secondary to the rupture of a mucinous lesion, usually of ovarian or appendiceal origin. MATERIALS AND METHODS: We present our experience of 11 cases (6 males and 5 females) diagnosed with pseudomyxoma peritonei secondary to epithelial appendicular neoplasms over 27 years. The mean age of the patients was 68 years. Clinical manifestations were abdominal distension (55%), right lower quadrant pain (45%) suggesting acute appendicitis and constitutional syndrome (36%). An abdominal mass was detected at physical examination in 4 patients. CT scan revealed a tumour in right iliac fossa in 4 patients, peritoneal enlargement in 1 and a liquid collection in 1. Preoperative diagnosis was acute abdomen in 5 patients, peritoneal carcinomatosis in 3 and undetermined abdominal mass in 3. RESULTS: Surgical findings suggested pseudomyxoma peritonei in 8 patients and peritoneal carcinomatosis in 3. Appendicectomy was performed in 9 patients, and in 3 of them bilateral anexectomy was also performed. One patient underwent ileocaecal resection and another a right hemicolectomy. In all the cases, mucinous material was eliminated as much as possible. Pathology revealed mucinous cystoadenoma in 6 cases, mucinous cystoadenocarcinoma in 3 and epithelial hyperplasia in 2 patients. Median survival was 54 months, with a 5- year survival rate of 40%. The last case we treated was sent to a reference centre for the treatment of pseudomyxoma peritonei. CONCLUSIONS: There is no consensus on the best treatment for pseudomyxoma peritonei. We recommend avoiding incomplete surgical resections in non-reference centres and submitting patients to a reference centre to undergo adequate treatment.

Peritoneal carcinomatosis secondary to carcinoid tumour.

Carcinoid tumours are neuroendocrine neoplasms that can appear in every location of the digestive tract. They are low aggressive tumours, although they often produce local invasion and hepatic metastases, whose resection allows long-term survival. We report a case of a 64-year-old man with ileal carcinoid tumour, that underwent ileal resection and metastasectomy of one lesion in liver segment II. Surgical findings indicated peritoneal carcinomatosis. Carcinoid dissemination as peritoneal carcinomatosis has been rarely described in the literature. Cytoreductive surgery, always when complete resection is aimed, achieves asymptomatic long-term survivals.

Mammary hamartoma.

INTRODUCTION: Mammary hamartomas are rare benign breast lumps. They are usually painless, wellcircumscribed, mobile and with no adherence to skin or muscle, composed of varying amounts of fat, glandular and fibrous tissue. Mammary hamartoma has been classically considered as an underdiagnosed pathology, but with the increasing use of diagnostic procedures in breast tumours, the number of hamartomas has increased in the last years. Because there is no distinct pathological feature, a correlation with the clinical findings and image techniques is necessary in order to achieve a correct diagnosis of the pathology. MATERIALS AND METHODS: The clinicopathological features of 8 mammary hamartomas are reported here. RESULTS: The patients are ranged in age from 34 to 67 years. The initial manifestation was in all cases a well-circumscribed, soft, palpable breast lump. Mammography was performed in all patients. Other diagnostic procedures used in the diagnosis were Ultrasound, Fine Needle Aspiration Cytology and Needle Core Biopsy. Treatment was tumorectomy. We describe a case of recurrence after excision of the lump in a more aggressive histological form and one patient who presented the coexistence of a mammary hamartoma and an invasive ductal carcinoma. CONCLUSION: Mammary hamartoma is an uncommon breast tumour. It is necessary the correlation between pathology and clinical and radiological findings. We express our management plan for these lesions.

Malignant mixed Mullerian tumors.

Malignant mixed Mullerian tumours (MMMTs) are rare neoplasms, highly aggressive and with an extremely poor prognosis, usually arising in elderly postmenopausal women and presenting at an advanced stage. MMMTs derive from the mullerian mesodermus that differentiates in epithelial and stromal elements, both malignant elements. The clinic pathological features of 3 uterine MMMTs are reported here. The patients ranged in age from 25 to 69 years. The initial manifestations were mainly bloody discharge, abdominal pain and increase of the volume of the uterus. Treatment in 2 patients was hysterectomy with double ooforectomy, and resection of the pelvic mass was the treatment in the third case. Adjuvant radio chemotherapy was administrated in 2 of the 3 cases. Follow-up revealed recurrent pelvic tumour in 1 patient at 59 months, and breast metastases at 20 months in the second one. Because of the high incidence of recurrence and poor prognosis of these tumours, they should be studied and managed by a multidisciplinary team composed by surgeons, oncologists, radiotherapists and pathologists.

Glutathione and the redox control system trypanothione/trypanothione reductase are involved in the protection of Leishmania spp. against nitrosothiol-induced cytotoxicity

Glutathione is the major intracellular antioxidant thiol protecting mammalian cells against oxidative stress induced by oxygen- and nitrogen-derived reactive species. In trypanosomes and leishmanias, trypanothione plays a central role in parasite protection against mammalian host defence systems by recycling trypanothione disulphide by the enzyme trypanothione reductase. Although Kinetoplastida parasites lack glutathione reductase, they maintain significant levels of glutathione. The aim of this study was to use Leishmania donovani trypanothione reductase gene mutant clones and different Leishmania species to examine the role of these two individual thiol systems in the protection mechanism against S-nitroso-N-acetyl-D,L-penicillamine (SNAP), a nitrogen-derived reactive species donor. We found that the resistance to SNAP of different species of Leishmania was inversely correlated with their glutathione concentration but not with their total low-molecular weight thiol content (about 0.18 nmol/10(7) parasites, regardless Leishmania species). The glutathione concentration in L. amazonensis, L. donovani, L. major, and L. braziliensis were 0.12, 0.10, 0.08, and 0.04 nmol/10(7) parasites, respectively. L. amazonensis, that have a higher level of glutathione, were less susceptible to SNAP (30 and 100 µM). The IC50 values of SNAP determined to L. amazonensis, L. donovani, L. major, and L. braziliensis were 207.8, 188.5, 160.9, and 83 µM, respectively. We also observed that L. donovani mutants carrying only one trypanothione reductase allele had a decreased capacity to survive (40 percent) in the presence of SNAP (30-150 µM). In conclusion, the present data suggest that both antioxidant systems, glutathione and trypanothione/trypanothione reductase, participate in protection of Leishmania against the toxic effect of nitrogen-derived reactive species.

Glutathione and the redox control system trypanothione/trypanothione reductase are involved in the protection of Leishmania spp. against nitrosothiol-induced cytotoxicity.

Glutathione is the major intracellular antioxidant thiol protecting mammalian cells against oxidative stress induced by oxygen- and nitrogen-derived reactive species. In trypanosomes and leishmanias, trypanothione plays a central role in parasite protection against mammalian host defence systems by recycling trypanothione disulphide by the enzyme trypanothione reductase. Although Kinetoplastida parasites lack glutathione reductase, they maintain significant levels of glutathione. The aim of this study was to use Leishmania donovani trypanothione reductase gene mutant clones and different Leishmania species to examine the role of these two individual thiol systems in the protection mechanism against S-nitroso-N-acetyl-D,L-penicillamine (SNAP), a nitrogen-derived reactive species donor. We found that the resistance to SNAP of different species of Leishmania was inversely correlated with their glutathione concentration but not with their total low-molecular weight thiol content (about 0.18 nmol/10(7) parasites, regardless Leishmania species). The glutathione concentration in L. amazonensis, L. donovani, L. major, and L. braziliensis were 0.12, 0.10, 0.08, and 0.04 nmol/10(7) parasites, respectively. L. amazonensis, that have a higher level of glutathione, were less susceptible to SNAP (30 and 100 microM). The IC50 values of SNAP determined to L. amazonensis, L. donovani, L. major, and L. braziliensis were 207.8, 188.5, 160.9, and 83 microM, respectively. We also observed that L. donovani mutants carrying only one trypanothione reductase allele had a decreased capacity to survive (approximately 40%) in the presence of SNAP (30-150 microM). In conclusion, the present data suggest that both antioxidant systems, glutathione and trypanothione/trypanothione reductase, participate in protection of Leishmania against the toxic effect of nitrogen-derived reactive species.

Bollgard cotton and resistance of tobacco budworm (Lepidoptera: Noctuidae) to conventional insecticides in southern Tamaulipas, Mexico.

Insecticide susceptibility in tobacco budworm, Heliothis virescens (F.) (Lepidoptera: Noctuidae), was determined for 8 yr (1991-2001) with larvae sampled from cotton in southern Tamaulipas, Mexico. Before 1996, when Bollgard cotton expressing the Cry1A(c) delta-endotoxin was introduced into the region, two important patterns were documented. The first was economically significant increases in resistance to certain insecticide groups. The second was occurrence of virtually complete control failures in the field during 1994 and 1995. The largest resistance changes were recorded for the type II pyrethroids cypermethrin and deltamethrin. These products are the most widely used products in the region. Resistance ratios for these products increased up to > 100-fold from 1991 to 1995. After 1996, the resistance levels declined. These findings did not occur with other products of scant use (e.g., permethrin, profenofos, and endosulfan) or low tobacco budworm efficacy coupled to a high use pattern (e.g., methyl parathion). This clear trend toward reversal of resistance to type II pyrethroids can be understood, in part, with respect to two factors: 1) the high adoption rate of transgenic cotton in the region, from 31.2% in the beginning (1996) to approximately 90% in 1998; this has considerably curbed the use of synthetic insecticides, with the attending loss of selection pressure on this pest; and 2) the potential immigration to the region of susceptible tobacco budworms from cultivated and wild suitable hosts as well as from transgenic cotton might have influenced the pest population as a whole. The influence of transgenic cotton on southern Tamaulipas can be more clearly seen by the drastic reduction of insecticide use to control this important pest. Now tobacco budworms in this region are susceptible to type II pyrethroids. Two effective and fundamentally different pest management tools are now available to cotton growers in southern Tamaulipas: transgenic cotton, coupled with careful use of pyrethroids, offers the possibility of sustainable and profitable cotton production.

[Association of physiologic responses to metabolic changes in exhaustive physical exercise]. / Asociación de las respuestas fisiológicas a los cambios metabólicos, en el ejercicio físico extenuante.

The purpose of this work was to identify changes in some hematic variables in recreational athletes of middle level competition exposed to exhaustive physical exercise, as well as the association among physiologic changes, personal characteristics, and physical level produced by marathon running. Ten healthy males participated (20-55 years of age). Blood cell count, blood chemistry, lipids, and enzymes were determined. Exercise produced hemoconcentration by reduction in plasma volume (8%; p<0.05). There was significant increment in leukocytes (149%) by neutrophilia (64%) and decrease in lymphocytes (74%). Fibrinogen increased 10.7% (p<0.05). Lipids (CT, C-HDL) did not modify, except C-LDL, which increased significantly (71%), attributing this response to stress of the marathon. Triglyceride decreased 47%. Enzymes increased significantly, particularly CK. Age and physical activity were related with physiologic and metabolic variables, as demonstrated by multivariate analysis. These data contributed to new knowledge in physiologic responses of our ethnic race when exposed to exhaustive exercise such as a marathon. To these results new approaches of risk and different schedules of intervention programs could be generated for better and effective practice of physical exercise in our population.

Cervicitis actinomicótica: reporte de un caso y revisión de la literatura / Antinomycosis cervix: report of a case and review of the literature

La actinomicosis es una enfermedad infecciosa crónica poco frecuente respecto a su forma clínica más usual. Los casos de actinomicosis que son diagnósticados tardiamente conducen a un manejo inadecuado y a procedimientos quirúrgicos innecesarios. Se reporta un caso de paciente femenina de 46 años de edad con historia clínica de hipermenorrea y anemia. El diagnóstico clínico fue el de miomatosis uterina y el diagnóstico histopatológico fue el de cervicitis por Actinomyces spp. Se hace una revisión de la literatura sobre la incidencia de la actinomicosis en diferentes órganos. Se debe considerar en el diagnóstico diferencial en aquellos casos de uso prolongado de dispositivos intrauterinos, para ayudar a mejorar el manejo y el pronóstico de esta enfermedad

Histiocitosis sinusoidal con adenopatia masiva (enfermedad de rosai-dorfman): presentación de un caso / Sinus histiocytosis with massive lymphadenopathy (disease rosai-dorfman): presentation of a case

La Histiocitosis Sinusoidal con adenopatía masiva o enfermedad de Rosai-Dorfman, se caracteriza por adenopatías cervicales prominentes, bilaterales, dolorosas que se asocian a fiebre, leucocitosis y anemia. La biopsia ganglionar muestra al estudio histológico, fibrosis capsular y sinusoides dilatados ocupados por histiocitos, los cuales suelen mostrar emperipolesis, como carcaterística fundamental. Clínicamente tiene curso indolente con desaparición espontánea de las adenomegalias. Se presenta el caso de un perescolar masculino de 5 años con clínica de adenomegalias cervicales bilaterales

Síndrome nefrótico congénito y síndrome de down: reporte de un caso y revisión de la literatura / Congenital nephrotic syndrome and down syndrome: report of case and literature revision

El síndrome nefrótico congénito durante el primer año de vida es poco frecuente en nuestro medio, al igual que en otros países de latinoamérica; lo contrario ocurre en otros países europeos donde la prevalencia es mayor: Se ha encontrado asociaciones de esta síndrome con alteraciones embrionarias como el nefroblastoma, anormalidades genitales, seudohermafroditismo, síndrome uñarótula y displasia congénita de la cadera. Se describe el caso clínico de un lactante menor femenina de 6 meses de edad con síndrome nefrótico congénito y síndrome de down; esta asociación no ha sido descrita previamente en la literatura nacional. El estudio histopatológico mostró disminución en el número de glomerulos y la lesión observada en los gromérulos fue una esclerosis mesangial difusa retráctil

Caso clínico rotura post parto de aneurisma de la arteria esplénica: presentación de un caso / Clinic case postpartum rupture of aneurism of the splenic artery: presentation of one case

Los aneurismas de la arteria esplénica son entidades patológicas raras, con riesgo de romperse y producir una hemorragia fatal. La rotura de un aneurisma de la arteria esplénica en el embarazo es una causa de emergencia obstétrica de rara presentación. La mortalidad para la mujer es del 69,4 por ciento y 90,8 por ciento para el feto. Estos aneurismas se presentan en el 95 por ciento de los casos de manera asintomática; pero un examen exhaustivo con ultrasonografía puede detectar el defecto. Se describe el caso de una mujer de 22 años, multípara con embarazo de 38 semanas, quien después de un parto eutócico y durante el puerperio inmediato presenta cuadro de shock hipovolémico y fallece. El estudio anatomopatológico macroscopico reveló hemorragia aguda intraabdominal por rotura de aneurisma de la arteria esplénica. Se destaca que la supervivencia de la paciente y el feto depende considerablemente de la detección temprana y rápida intervención

[Validation and reliability of the 1,000 meter aerobic test]. / Validación y confiabilidad de la prueba aeróbica de 1,000 metros.

BACKGROUND: In humans, measurement of maximum oxygen uptake is important because it is related to cardiovascular health. In Mexico there is scanty information in nationals and unfortunately such a data has been gathered from laboratory and field indirect methods ignoring reliability, validation and cross validation. PURPOSE: This study was designed to determine the validity and reliability of the 1,000 meters walk-run test in adults. METHODS: Fifty-one healthy subjects (31 men and 20 women) participated in four maximal tests; two in a laboratory on a treadmill for direct measurement of VO2max (L1 and L2) and twice in a track for distance walk-run time in 1,000 meters (C1 and C2). Values were analyzed by interclass correlation, Pearson product moment and "t" test. RESULTS: The VO2max in L1 y L2 were 2.67 and 2.70 L.min-1, (R = 0.97) and 44.2 and 46.2 mL.kg-1.min-1, meanwhile VO2max estimated from field were 44.2 and 46.2 mL.kg-1.min-1, (R = 0.98). Pearson correlation obtained from all subjects between laboratory and field test was of r = 0.88, without significant difference (P > 0.05). From those data we development the following equation: VO2max = 71.66-5.85 (t), where 71.66 and 5.85 are constants and t is the time employ in performing the test, R = -0.86, (p < 0.05). CONCLUSION: The 1,000 meters distance walk-run for time is highly reliable and valid test for estimation of VO2max in Mexican people. The test is safe, easy and short and can be administrated with a minimal amount of equipment. We propose its utilization in other population in order to perform cross validation.

Efectos de la anastomosis esofágica a tensión: Estudio experimental de las causas de reflujo en la atresia de esófago / Esophageal anastomosis under tensio: experimental study about the causes for GER in repaired esophageal atresia

El reflujo gastroesofágico se diagnostica con frecuencia después de la reparación de una atresia de esófafo.El objetivo de este estudio es demostrar que uno o más componentes de la barrera esofagogástrica se alteran como consecuencia de una anastomosis esofáfica a tensión.La presión del esfínter esofágico inferior(PEEI)la presión de los pilares del diafragma(PPD)la longitud del esófago intraabdominal(LEIA) se midieron mediante una nanometría esofágica de retirada en 20 ratas antes y después de una resección esofágica de 15 mm y en 8 ratas antes y después anastomosisesofágica sin tensión(grupo control).La PEEI disminuyó de 44,9ñ 17,4 a 30,9ñ 12,3 mnHg y la LEIA de 17,9ñ2,9 a 15,8ñ 2,4 mn(p<0,05)en el grupo experimental,mientras que en el grupo control no hubo cambios significativos.La PPD no varió en ninguno de los dos grupos.En este modelo,la anastomosis esofágica a tensión disminuyó significativamente la presión del esfínter esofágico inferior y la longitud del esófago intraabdominal,pero no cambió las presiones del diafragma crural.El reflujo posoperatorio encontrado en pacientes operados de atresia de esófago se podría deber en parte a este mecanismo