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Cyclic vomiting syndrome (CVS) is a disorder characterized by recurrent and unpredictable episodes of intense vomiting, interspersed with periods of apparent wellbeing. This disorder, which primarily affects children and adolescents but can persist into adulthood, has recently been the subject of extensive study and analysis in the medical literature. The aim of the present review is to examine the most important aspects of the epidemiology, pathophysiology, subtypes, diagnostic criteria, and current management of CVS. Even though the exact etiology remains unknown, genetic factors (polymorphisms), nervous system alterations and autonomic dysregulation, and environmental factors (use and abuse of cannabinoids) are postulated as possible triggers. CVS has significant diagnostic challenges, given that there is no specific test for confirming its presence. Thorough evaluation of symptoms and the ruling out of other possible causes of recurrent vomiting are required. Management of CVS typically involves a multidisciplinary approach. Pharmacologic options are explored, such as antiemetics and preventive medications, as well as behavioral and psychologic support therapies. Treatment personalization is essential, adapting it to the individual needs of each patient. Despite advances in the understanding of CVS, it remains a significant clinical challenge. This disorder impacts the quality of life of those affected and their families, underscoring the ongoing need for research and the development of more effective treatment strategies.

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The reliability of activated sludge processes will be adversely affected by alterations in wastewater production and pollutant loading foreseen due to population growth, urbanization, and climate change, as well as the tendency to amend environmental regulations to mandate stricter effluent quality standards to alleviate water pollution. Until now, there was no framework capable of effectively managing these multifaceted challenges in reliability analysis. Previous attempts conducted a low number of simulations leading to insufficient statistical significance to properly validate reliability quantification. A metamodeling-based reliability analysis framework for the activated sludge process is introduced to cope with alterations in wastewater production and pollutant loading, assesses the reliability under different effluent regulations, and leverages metamodels to conduct extensive simulation work, to estimate the reliability. All metamodels produced high-resolution results, enabling reliability estimation after 100 000 simulations. The framework effectively assessed the annual failure rates of various activated sludge facility designs under four regulations, demonstrating the impact of stricter effluent quality standards. Integrating metamodels for reliability analysis greatly lowers computational costs, making the framework a time and resource-efficient choice for quick decision-making in facility design.

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INTRODUCTION AND AIM: Endoscopic retrograde cholangiopancreatography (ERCP) is a complex procedure. Clinical guidelines assess competence in ERCP through a defined number of procedures, but multiple factors are involved. Our aim was to analyze the morphology of the papilla of Vater as an independent factor in selective common bile duct cannulation during resident training. MATERIAL AND METHODS: Patients that underwent ERCP were studied consecutively. All ERCPs were begun by a resident in training. The type of papilla was classified according to Haraldsson, including those with previous sphincterotomy. Cannulation difficulty and success and their relation to the type of papilla were documented. The analysis was divided into three 4-month periods. RESULTS: Of the 429 patients, cannulation was difficult in 101 (23.5%). The residents achieved selective cannulation of the common bile duct in 276 (64.3%) and the cannulation success rate at the end of their training was 81.7%. Cannulation was performed with the least difficulty in papillae with previous sphincterotomy (2.8%), unlike the type 4 papilla, which was difficult to cannulate in 50% of the cases. The lowest overall cannulation success was in the type 2 papilla (81.8%). CONCLUSION: Papilla type can influence cannulation success, but it is not the only related factor. Patients that underwent previous sphincterotomy appear to be the cases in whom ERCP training can be started.

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INTRODUCTION AND AIM: Transnasal endoscopy (TNE) has proven its diagnostic utility, but it has not been widely accepted given that it is performed without sedation. There are no previous studies on the use of methods to improve its tolerability. Our aim was to evaluate the tolerability of TNE, when simultaneously performed with an audiovisual device as a distractor. METHODS: We evaluated 50 patients, 10 of whom did not agree to participate. The performance of the procedure was explained, using an audiovisual device. Before randomization, we applied anxiety and depression scores. Patients were divided into 2 groups: Group I (using an audiovisual device during the procedure) and Group II (without a device). Anxiety and numeric pain rating scales were used, and vital signs were monitored and recorded before, during, and after the endoscopy. An overall procedure satisfaction score was applied at the end of the study and 24 h later. RESULTS: Mean age was 41.6 years and 35 of the patients were women (87.5%). The most frequent indication for TNE was refractory gastroesophageal reflux disease. There were no severe comorbidities, and none of the patients had a significant anxiety or depression score. One patient in Group II did not tolerate TNE due to nasal pain. There was no statistically significant difference between groups, regarding anxiety, pain, vital signs, and satisfaction scale. CONCLUSION: Our study showed that TNE was well tolerated and had a high acceptance rate in our patients. The use of distracting audiovisual devices did not increase tolerance to the endoscopic procedure.

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BACKGROUND AND OBJECTIVE: Cytospin conventional cytomorphology (CCC) is the standard method for detecting lymphoblasts in cerebrospinal fluid (CSF) of patients with acute lymphoblastic leukemia (ALL) and for guiding treatment decisions. We evaluated flow cytometry immunophenotyping (FCI) performance for improving detection of central nervous system (CNS) involvement in ALL. METHODS: This prospective study included analysis of consecutive CSF samples of patients of all ages with ALL at 3 clinical stages: new diagnosis, relapse suspicion, and after relapse treatment. Manual, cytospin, automated, and FCI methods were compared and their performance statistically assessed. Using FCI as the reference method, optimal CSF cutoff cell count that better correlated with presence of lymphoblasts was established by receiver operating characteristic (ROC) curve analysis. RESULTS: Seventy-seven CSF samples were investigated, 35 (45.4%) from newly diagnosed cases, 30 (39%) suspicion of relapse, and 12 (15.6%) after treatment for relapse. Median manual WBC count in patients with CNS involvement detected by FCI was 3.75 cells/µL (0.0-1280), and this was also the count that best correlated with CNS infiltration (sensitivity, 50.0%; specificity, 82.2%). Compared with FCI, CCC sensitivity and specificity were 28.6% and 100%. Automated CSF WBC count in patients with CNS involvement detected by FCI was 5 (0.0-1578). For automated count, optimal WBC cutoff was 4.5 cells/µL (sensitivity, 62.5%; specificity, 70.5%). CONCLUSION: Flow cytometry immunophenotyping complements conventional cytospin analysis for detection of lymphoblasts in the CSF of ALL patients at any clinical stage.

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Epilepsy is a disease characterized by unprovoked epileptic seizures resulting from a bioelectrical brain dysfunction. Antiepileptic treatment controls 75% of all epileptic patients; the other 25% continue to have epileptic seizures in spite of a combination of multiple antiepileptic drugs. The purpose of this work was to evaluate the use of methylprednisolone in the treatment of children with refractory epilepsy. Fourteen children with refractory epilepsy at the Hospital de Especialidades No. 25 of the Instituto Mexicano del Seguro Social in Monterrey, Northeast Mexico were included. For five consecutively days, each patient received methylprednisolone by intravenous administration at a dosage of 15 mg/kg/day each 8 h, once a month for 3 months. The frequency of epileptic seizures and possible related side effects were evaluated every month during the three months before, during, and after administration of methylprednisolone. The frequency of epileptic seizures was reduced by more than 50% in 12/14 patients during methylprednisolone treatment. The median number of seizures before treatment with methylprednisolone was 8, 8, and 7; during the treatment: 1, 1, and 1; and after treatment: 2, 2, and 3 (p=0.000). We conclude that methylprednisolone reduces the frequency of epileptic seizures in children with refractory epilepsy.

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In gynodioecious populations, the frequency of females is expected to have a strong influence on the contemporary genetic structure of populations. Historical patterns of range contraction and expansion are also known to influence the genetic diversity of plant populations. We explore the influence of male sterility and colonization history on the genetic diversity in populations of Kallstroemia grandiflora along the Pacific of México. Both the overall population Fis and Fis values of hermaphrodites showed a negative association with female frequency. Genetic diversity declined with latitude. Our results provide evidence that females have a significant effect on the genetic structure as predicted by theoretical models and provide support for the hypothesis that historical processes have modified the genetic structure of K. grandiflora.

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Cervical cancer constitutes a major health problem in Mexico and other developing countries. The purpose of our study was to assess the experience of a comprehensive national oncological reference center on pelvic exenteration for post-radiotherapy recurrent or persistent cervical cancer, describing the prognostic value of time to recurrence, procedure complications, and survival. Medical records from 42 patients with post-radiotherapy recurrent or persistent cervical cancer who underwent a pelvic exenteration with curative purposes from 1984 to 1989 were retrospectively reviewed. Histological diagnoses were squamous cell carcinoma (32 patients), adenosquamous carcinoma (9 patients), and adenocarcinoma (1 patient). Average follow up was of 56.3 mo after the procedure and global survival at 5 yr was 65.8%. Survival for patients with early recurrence was 56.9% vs 78% for patients with late recurrence (p = 0.05). Complications were observed in 65.3% of the cases with a surgical mortality of 4.8%. Pelvic exenteration is a surgical procedure with high morbidity in spite of the recent medical advances. Pelvic exenteration should not be indicated with palliative purposes owing to the high rate of complications. Patients with tumor persistence or early recurrence have a worse prognosis. In well-selected cases, exenteration may provide a survival benefit.

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In clinical experience, guided tissue regeneration has been associated with complications, which include membrane exposure. The maintenance of a stable blood clot under the membrane is key to a successful regenerative outcome. This requires adequate membrane stabilization, tension-free suturing, and maintenance of a good vascular supply to the defect. Careful selection of defects after a thorough periodontal evaluation and modification of surgical techniques from those used for conventional resective procedures can lead to predictable outcomes for guided tissue regeneration.

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OBJECTIVE: Our purpose was to compare third-trimester fetal biophysical activities in normal and well-controlled insulin-dependent diabetic pregnancies. STUDY DESIGN: We performed serial bimonthly fetal biophysical studies from 30 to 38 weeks in 18 normal and 18 well-controlled insulin-dependent diabetic pregnancies (White classes B through D). Each study contained 60 minutes of simultaneous ultrasonographic recordings of fetal breathing movements and rates, baseline heart rate, and body movements. Mean daily blood glucose levels of diabetic patients were determined from home monitors; HbA1c was determined every 6 weeks and ultrasonographic fetal growth rates every 3 weeks. Data were compared with t tests, analysis of variance with repeated measures, and chi 2 tests. RESULTS: Women in the diabetic group maintained good glycemic control and were delivered of normal infants of weights similar to those of nondiabetic gravidas. Their fetuses had higher mean incidences of fetal breathing movement, fetal heart rates, and fetal breathing rates but lower fetal movements and fetal heart rate acceleration counts than did controls throughout the study. Neither short- nor long-term maternal glycemic levels correlated well with fetal biophysical performance. CONCLUSIONS: In spite of good maternal glycemic control fetuses of diabetic women behaved differently from those of nondiabetic women. Modulation of their biophysical activities may be affected by maternal glycemic status before the last trimester. Different standards might need to be applied to interpret their tests.

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The synthesis of (3S,6R)-3-hydroxy-1,7-dioxaspiro[5.5]undecane (8) and its (4R)-4-hydroxy isomer (11) from (3R,4S,6R)-3,4-dihydroxy-1,7-dioxaspiro[5.5]undecane (1), obtained from D-fructose, has been accomplished by regioselective deoxygenation at C-4 and C-3, respectively, of the appropriately protected derivatives.

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The synthesis of the title compound13 has been carried out through the preparation of its precursor, (3R,4R,5S,6R)-3,4,5-trihydroxy-1,7-dioxaspiro[5.5]undecane (6), obtained fromD-fructose using Wittig's methodology, reduction, and spiroketalation. Compound6 was transformed into13 by a Barton deoxygenation at C-5 followed by a Corey dideoxygenation at C-3,4 of the appropriately protected derivatives.

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To determine the values of individual and combined biophysical fetal surveillance tests in a general high-risk population, we examined 1000 consecutive pregnancies complicated by either postdatism, hypertension, intrauterine growth retardation, or diabetes mellitus. Nonstress tests, amniotic fluid pocket measurements, and umbilical artery Doppler velocimetry were performed on each patient; each test was rated against gestational age-adjusted standards. Clinical end points included perinatal mortality, intrapartum fetal distress, 5-minute Apgar score less than 7, and neonatal acidosis in pregnancies without major anomalies or extreme prematurity (age at birth greater than 32 weeks), delivered within 72 hours of final tests. Each testing method had specificity greater than 90%. Sensitivities ranged from 69% (nonstress test) to 21% (Doppler velocimetry). Negative predictive values of each method exceeded 85%; positive predictive values ranged from 81% (nonstress test) to 42% (amniotic fluid measurements). The positive predictive value for any abnormal test was 54% and increased to 100% when all tests were abnormal; this latter condition occurred in only 2% of the total population. Amniotic fluid measurements or Doppler velocimetry, when compared with the nonstress test, appeared to be less powerful "stand-alone" screening tests. The performance of all tests in a single session confers little improvement in detection of fetal compromise if the nonstress test is normal; however, this approach may aid decision-making in the management of pregnancies when fetal maturity is not established.

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To determine the fetal biophysical effects of vibroacoustic stimulation produced by an electronic artificial larynx we studied 20 normal term pregnancies assigned either to control (no stimulus) or experimental (stimulus) groups. Each fetus was observed for 3 hours; either no stimulus or a 3-second stimulus was delivered after the first hour. Fetal heart rate baseline and variation, breathing movement incidence, rate, and variation, and body movement incidence data were acquired concurrently and analyzed at 15-minute intervals. Intergroup comparisons showed that, after stimulation, fetal heart rate baseline and variation increased significantly, whereas breathing incidence fell during the first 15 minutes. Within-group analyses showed that poststimulus elevation of fetal heart rate baseline was the only significant time interaction over the 3 hours. Vibroacoustic stimulation appears to be primarily associated with transient alterations in fetal heart rate baseline; concomitant changes in breathing activity probably reflect normal biologic cycles.

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Central pontine myelinolysis, also known as osmotic demyelination syndrome, is an uncommon disorder associated with rapid correction of severe hyponatremia. We present the case of a healthy young pregnant woman with hyperemesis gravidarum who developed severe hyponatremia (serum sodium 103 mEq/L). After rapid correction of her serum sodium within 12-15 hours with a 0.9% saline solution, the patient became comatose and died of sepsis and respiratory failure. Examination of the brain showed extensive demyelination in both pontine and extrapontine areas.

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A computer-assisted biophysical assessment was performed in a woman with chronic alcoholism at 37 weeks' gestation. She was first seen in a state of acute alcohol intoxication (322 mg/dl). Although fetal breathing movement incidence was normal (30%), fetal tachypnea (67 breaths per minute) and decreased fetal body movements (0.11%) were seen. Because these findings differ from those previously reported with regard to normal pregnancies exposed to lower levels of alcohol, their implications are discussed.

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The application of the nonstress test between 24 and 32 weeks' gestation has been limited by high rates of "false" nonreactivity in normal fetuses, by use of term criteria, and the lack of age-appropriate interpretative standards. To establish such standards, we studied 30 normal fetuses undergoing 90-minute fetal heart rate recordings at 2-week intervals from 24 to 32 weeks' gestational age. Using a specially programmed computer we quantified (1) baseline fetal heart rate, (2) incidence of 10- and 15-beat accelerations, and (3) incidence of fetal heart rate decelerations. With a criterion of three 15-beat accelerations per 30 minutes 91% of tests were reactive within 90 minutes. A criterion of three 10-beat accelerations per 30 minutes was associated with 100% reactivity within 60 minutes. Suitable interpretative criteria may be established for nonstress tests before 32 weeks' gestation by extending the testing time or by decreasing the minimum amplitude required of fetal heart rate accelerations.

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O objetivo deste estudo foi provar que mudando o fluxo de gases fescos em ventiladores, alteraria o Vt (volume corrente) liberado para o paciente. Quatro ventiladores foram selecionados: Narco Air Shields, 702 Frazer Harlake, Dreger A-V e Ohio 7.000. Os volumes gerados pelos quatro ventiladores foram medidos, enquanto trocas no fluxo de gases frescos estavam sendo feitas simultaneamente. Os fluxos de gases frescos foram inicialmente fixados em 10 L. min-1 e a cada 15 minutos foram diminuídos em 1 L. Medidas de Vc (volume corrente) e V (volume minuto) foram feitas e os autores concluíram que os ventiladores estudados falharam em liberar o Vt indicado, quando os FGF foram trocados. A necessidade de um expirômetro foi observada como sendo uma maneira precisa de verificar o exato volume corrente liberado para o paciente anestesiado, tendo a respiraçäo mecanicamente controlada

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Fetal biophysical testing with arbitrary scores for fetal heart rate (FHR), breathing movements, body movements, tone, and amniotic fluid volume has not proved to be highly sensitive or significantly better than FHR testing alone. Using a computerized analysis system for simultaneously acquired biophysical variables, we studied 200 high-risk fetuses near term. The dynamic parameters obtained for each fetus were compared with established nomograms, and overall test results correlated with the presence or absence of perinatal mortality, fetal distress, a 5-minute Apgar score less than 7, and intrauterine growth retardation for those delivered within 7 days of the last test. A test was considered abnormal if two or more parameters fell more than 2 standard deviations from the population mean. A decreased incidence of fetal body movements, amniotic fluid volume, and frequency of FHR acceleration were the most common individual test abnormalities. Test sensitivity (86%), specificity (89%), positive predictive value (75%), and negative predictive value (93%) exceeded those of the "standard" scoring approach and correctly identified all fetuses with malformation, perinatal death, and 19 of 22 fetuses with intrauterine growth retardation.

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