Dicyano and pyridine derivatives of ß-carotene: synthesis and vibronic, electronic, and photophysical properties.

Density functional theory and time-dependent density functional theory calculations provide pictures of the molecular orbitals involved in the ground and excited states of two cyano derivatives of 8'-apo-ß-caroten-8'-al synthesized via an acid-base-catalyzed Knoevenagel condensation reaction. Population analysis shows that the symmetry-allowed transition, S(0) ((1)A(g)) → S(2) ((1)B(u)) based on the C(2h) symmetry is a HOMO (highest occupied molecular orbital) to LUMO (lowest unoccupied molecular orbital) π → π* transition with electron densities located mostly on the polyene chain. Calculated and actual steady-state absorption spectra show similar features with low-energy peak maxima between 550 and 600 nm.

Dicyano and pyridine derivatives of retinal: synthesis and vibronic, electronic, and photophysical properties.

Two new derivatives of all-trans retinal, one containing a pyridine and a cyanide substituent, all-trans-15-cyano-15'-pyridylretinal (2), and the other containing two cyanide substituents, all-trans-15,15'-dicyanoretinal (3), have been synthesized from all-trans-retinal (1) by the Knoevenagel reaction. Compound 2 crystallizes in the space group P1; compound 3 crystallizes in the space group P2(1)/n. The polyene chains are bowed. The compounds exhibit C[triple bond]N vibrations in the infrared and Raman regions and undergo irreversible oxidations. Compounds 2 and 3 display electronic absorptions with maxima located at 442 and 487 nm and emission peaks located at 583 and 500 nm, respectively. Density Functional Theory and Time Dependent Density Functional Theory calculations reveal that the electronic transition from the HOMO to the LUMO can be associated with the A(g) --> B(u) electronic transition and a peak corresponding to the HOMO --> LUMO+1 transition can be associated with the "cis-peak".

[Nutritional management of intestinal failure and potential stimulation mechanisms]. / Tratamiento nutricional del fallo intestinal y potenciales mecanismos de estimulación.

Severe forms of intestinal failure represent one of the most complex pathologies to manage, in both children and adults. In adults, the most common causes are chronic intestinal pseudo-obstruction and severe short bowel syndrome following large intestinal resections, particularly due to massive mesenteric ischemic, within the context of cardiopathies occurring with atrial fibrillation. The essential management after stabilizing the patient consists in nutritional support, either by parenteral or enteral routes, with tolerance to oral diet being the final goal of intestinal adaptation in these pathologies. Surgery may be indicated in some cases to increase the absorptive surface area. Parenteral nutrition is an essential support measure that sometimes has to be maintained for long time, even forever, except for technique-related complications or unfavorable clinical course that would lead to extreme surgical alternatives such as intestinal transplantation. Hormonal therapy with trophism-stimulating factors opens new alternatives that are already being tried in humans.

[The Journals role in continuing medical education]. / El papel de las publicaciones periódicas en la educación continua.

In the 19th century, the first journals in medicine appeared in order to disseminate knowledge among creators and discoverers, but especially among users of knowledge, some of these journals continue to be published nowadays. Subsequently, an organization that initially aspired to collect, sort, archive and distribute the publications: the Index Medicus. Over time, it was imperative to create indexes that measure the performance of journals and with that of researchers.

En el siglo XIX surgen las primeras publicaciones periódicas en medicina con la finalidad de difundir el conocimiento entre los creadores y descubridores del mismo pero, sobre todo, entre los usuarios del conocimiento; con el tiempo fue imperiosa la necesidad de crear índices que midieran el desempeño de las revistas y con él, el de los investigadores.

[Why a degree of speciality instead of a Master's?] / ¿Por qué especialidad y no maestría?

It was at the beginning of the last century, in the hospitals where most of the attention was given, when it was established the habit of admitting apprentices as members of the medical team. However, it was not clearly established how aspirants were admitted, how their learning was to be developed, or what their functions were.

Fue a principios del siglo pasado, en los hospitales donde se brindaba la mayor parte de la atención, cuando se fue estableciendo la costumbre de admitir aprendices como miembros del equipo médico. Sin embargo, no estaba claramente establecido cómo se admitía a los aspirantes, de qué manera se iba a desarrollar su aprendizaje, o en qué consistían sus funciones.

[The evaluation of science]. / La evaluación de la ciencia.

The evaluation and quantification of scientific activity is an extremely complex task. Evaluation of research results is often difficult, and different indicators for the quantification and evaluation of scientific publications have been identified, as well as the development and success of the training programs of researchers.

La evaluación y la cuantificación de la actividad científica es una tarea sumamente compleja. La evaluación de los resultados de la investigación suele ser difícil, por lo que se han identificado diferentes indicadores para la cuantificación y valoración de las publicaciones científicas, así como el desarrollo y éxito de los programas de formación de los investigadores.

[The ENARM and the schools and faculties of medicine. An analysis that nobody will like]. / El ENARM y las escuelas y facultades de medicina. Un análisis que no le va a gustar a nadie.

In Mexico, the career of Doctor of Medicine has been considered as a prerequisite stage to access the specialization. Of course the majority of medical graduates aspire to undertake postgraduate courses in the different institutions that have a university program. The Examen Nacional de Aspirantes a Residencias Médicas (ENARM) (National Evaluation for Medical Residency Applicants) has become for the supporters a gap between the possibility of practicing the profession in a decent way and with a regular remuneration or exercising it in very limited conditions and with low economic income or even without exercising it. For educational institutions, the ENARM and the percentages of selection of their graduates are indicators of efficiency and a source of prestige and even of propaganda among the aspirants to study medicine. In this study, we carried out an analysis of the results of the ENARM in the last 15 years. For this we refer to the reports of the Postgraduate and Continuing Education Committee of the CIFRHS of the Directorate of Health Education of the General Directorate of Quality and Health Education Of the Undersecretariat of Innovation and Quality of the Ministry of Health, from the examination carried out in 2001 to the one carried out in 2016.

En México, la carrera de médico cirujano se ha considerado como una fase propedéutica para acceder a la especialización. Desde luego, la mayoría de los egresados de la carrera de medicina aspiran a realizar cursos de posgrado en las diferentes instituciones que tienen un programa universitario. El Examen Nacional de Aspirantes a Residencias Médicas (ENARM) se ha convertido para los sustentantes en un parteaguas entre la posibilidad de ejercer la profesión de una manera digna y con una retribución en promedio buena o ejercerla en condiciones muy limitadas y con ingresos económicos bajos o incluso no ejercerla. Para las instituciones educativas el ENARM y los porcentajes de selección de sus egresados son indicadores de eficiencia y motivo de prestigio e incluso de propaganda entre los aspirantes a estudiar medicina. En el presente estudio, realizamos un análisis de los resultados del ENARM en los últimos 15 años. Para ello consultamos los informes del Comité de Posgrado y Educación Continua de la Comisión Interinstitucional para la Formación de Recursos Humanos para la Salud (CIFRHS) de la Dirección de Educación en Salud de la Dirección General de Calidad y Educación en Salud de la Subsecretaría de Innovación y Calidad de la Secretaría de Salud, a partir del examen realizado en el año 2001 al realizado en 2016.

Perspectives in the design and development of new products for enteral nutrition.

Enteral nutrition is a technique that even though it was used in times immemorial, in the last 25 years has suffered a considerable development, from being considered a secondary therapeutic weapon destined only to feed the patient, to occupying an important status that goes beyond the single act of nourishing. The quantitative composition but overall the qualitative one, is object of an interesting argument in which a profile allowing the modulation of certain aspects of the organism response through the supplementation with different nutrients is searched. That includes from the keeping of the intestinal trophism and of the anti-bacteria intestinal barrier, so important to avoid the frightening multiple organ dysfunction, up to the lessening of the Systemic Response Inflammatory Syndrome (SRIS), going through the immuno-modulative feeding concepts, specific-feeding, pharmaco-nutrient or eco-nutrition. In this new dynamic not only certain nutrients such as glutamine, arginine, nucleotides, omega-3 fatty acids and many antioxidants have acquired importance, but also the manipulation of other molecules of a non- nutritional nature, such as hormones, cytokines and blockers. These aspects that imply passionate ways of investigation for the future are born from the better knowledge that is being acquired from such a severe pathophysiology processes such as sepsis and the organism response before fast and severe aggression; therefore, the modulation of that response through changes in the quantitative and qualitative formulas composition is being attempted.

[Malnutrition prevalence in patients admitted to a rehabilitation and orthopedic surgery hospital]. / Prevalencia de desnutrición en pacientes ingresados en un hospital de rehabilitación y traumatología.

OBJECTIVE: Different studies show the scarce attention granted to the nutritional state in historical and clinical practice, what determines the ignorance of the patient's nutritional status to their entrance in the hospital and, therefore, the impossibility to prevent the hospital malnutrition. The objective of our study has been to determine the prevalence of patients' malnutrition entered in a Hospital of Orthopedic surgery and Rehabilitation. METHODS: Observational and analytical study in 250 randomized patients (60% men and 40% women), who were nutritionally evaluated when entering, the hospital, by means of anthropometry (Weigh, height, BMI, skin-fold, corporal circumferences) and biochemical tests (Albumin, Prealbumin and Transferrin). RESULTS: According to the BMI the prevalence of malnutrition was of 8%, the average of caloric malnutrition was of 2.8% (according to anthropometry) and the prevalence of many-sided malnutrition rises to 54.8% (according to biochemical markers). CONCLUSIONS: The high prevalence of fundamental malnutrition (54.8%) demonstrated in this study, it shows the importance of determining the nutritional status when entering the hospital, particularly surgical type' patiens as is the case of most of those who enter the Orthopedic surgery hospitals.

Monitoring aminophylline therapy using Jusko's dosage guidelines.

Treatment with aminophylline, according to the nomogram published by Jusko and coworkers, was monitored in 13 patients suffering from acute exacerbations of COPD. After 24 h of therapy, the clinical state, the pO2 and the pCO2 values were markedly improved. Theophylline plasma concentrations were maintained within the therapeutic range. A slight but noticeable increase of drug serum levels during therapy could be related to changes in the arterial pH; the implications of this finding are discussed.

Variations in oxygen consumption and carbon dioxide production during parenteral nutrition.

To verify that variations caused by total parenteral nutrition (TPN) in O2 intake (VO2) and CO2 output (VCO2) can affect respiratory function of non-hypercatabolic patients, we studied 18 patients in two groups; group I (control): eight patients receiving 75-100 g glucose/24 h, and group II: ten patients fed intravenously on 13.6 g N2 and approximately 2,800 kcal/24 h given as a) 62% glucose + 38% fats (TPN-G + F) and b) 100% glucose (TPN-G). VO2, VCO2, respiratory quotient (RQ) and minute ventilation (VE) were measured in all patients. We found that VCO2 was 27% higher in intravenously fed patients (p less than 0.01 and p less than 0.02). Similarly, VE was 26% higher in intravenously fed patients (p less than 0.001 and p less than 0.02). Comparison of TPN-G + F and TPN-G results showed no differences in VCO2; by contrast, VO2 was 21% less during TPN-G (p less than 0.01).

Subcutaneous emphysema: an unusual presentation of foreign body in the airway.

Six children with a foreign body in the airway presented with progressive subcutaneous emphysema as a clinical feature. The aim of this report is to highlight this unusual clinical presentation of foreign body in the tracheobronchial tree. A peculiar arrangement of fascial planes in the neck, chest, and abdomen and an excessive pressure gradient at the alveolar level, facilitates extraalveolar migration of air in the subcutaneous tissue.

Phenomenological and neural-network modeling of cephalosporin C production bioprocess.

Cephalosporin C production process with Cephalosporium acremonium ATCC 48272 in synthetic medium was investigated and the experimental results allowed the development of a mathematical model describing the process behavior. The model was able to explain fairly well the diauxic phenomenon, higher growth rate during the glucose-consumption phase, and the production occurring only in the sucrose-consumption phase. Moreover, the process was simulated utilizing the neural-networks technique. Two feed-forward neural-networks with one hidden layer were employed. Both models, phenomenological and neural-networks based, satisfactorily describe the bioprocess. The difficulties in determining kinetic parameters are avoided when neural networks are utilized.

A hybrid neural network algorithm for on-line state inference that accounts for differences in inoculum of Cephalosporium acremonium in fed-batch fermentors.

One serious difficulty in modeling a fermentative process is the forecasting of the duration of the lag phase. The usual approach to model biochemical reactors relies on first-principles, unstructured mathematical models. These models are not able to take into account changes in the process response caused by different incubation times or by repeated fedbatches. To overcome this problem, we have proposed a hybrid neural network algorithm. Feedforward neural networks were used to estimate rates of cell growth, substrate consumption, and product formation from on-line measurements during cephalosporin C production. These rates were included in the mass balance equations to estimate key process variables: concentrations of cells, substrate, and product. Data from fed-batch fermentation runs in a stirred aerated bioreactor employing the microorganism Cephalosporium acremonium ATCC 48272 were used. On-line measurements strongly related to the mass and activity of the cells used. They include carbon dioxide and oxygen concentrations in the exhausted gas. Good results were obtained using this approach.

Modeling and simulation of cephalosporin C production in a fed-batch tower-type bioreactor.

Immobilized cell utilization in tower-type bioreactor is one of the main alternatives being studied to improve the industrial bioprocess. Other alternatives for the production of beta-lactam antibiotics, such as a cephalosporin C fed-batch process in an aerated stirred-tankbioreactor with free cells of Cephalosporium acremonium, or a tower-type bioreactor with immobilized cells of this fungus, have proven to be more efficient than the batch process. In the fed-batch process, it is possible to minimize the catabolite repression exerted by the rapidly utilization of carbon sources (such as glucose) in the synthesis of antibiotics by utilizing a suitable flow rate of supplementary medium. In this study, several runs for cephalosporin C production, each lasting 200 h, were conducted in a fed-batch tower-type bioreactor using different hydrolyzed sucrose concentrations. For this study's model, modifications were introduced to take into account the influence of supplementary medium flow rate. The balance equations considered the effect of oxygen limitation inside the bioparticles. In the Monod-type rate equations, cell concentrations, substrate concentrations, and dissolved oxygen were included as reactants affecting the bioreaction rate. The set of differential equations was solved by the numerical method, and the values of the parameters were estimated by the classic nonlinear regression method following Marquardt's procedure with a 95% confidence interval. The simulation results showed that the proposed model fit well with the experimental data, and based on the

Changes in the total content of iron, copper, and zinc in serum, heart, liver, spleen, and skeletal muscle tissues of rats infected with Trypanosoma cruzi.

The effects of the Trypanosoma cruzi infection on the total content of the essential trace elements iron (Fe), copper (Cu), and zinc (Zn) in serum, heart, liver, spleen, and skeletal muscle were determined in "Wistar" rats inoculated with reticulotropic "Y" strain trypanosomes (Tryps) in their slender blood form. The 250 rats were divided in two groups of 80 rats (L-1 and L-2) and one of 90 (C) used as controls. L-1 and L-2 were inoculated with 2 x 10(5) and 5 x 10(2) Tryps, respectively. Ten rats of the C group were killed the inoculation day (i), and ten rats of each group chosen at random were killed and blood parasitemia determined at 5, 10, 15, 20, 25, 30, 60, and 90 post-i days covering the infection acute-phase myocarditis. Previously cryohomogenized and lyophilized tissues were digested in an HNO3- H2O2 mixture with the aid of a microwave oven, and the elements Fe, Cu, and Zn were determined by Flame Atomic Absorption Spectrometry. Generally, more intense changes were observed in the L-1 group. Serum Fe and Zn levels are lower and Cu levels higher in groups L-1 and L-2 than in C. However, Fe is not significantly sequestered in the liver during the acute phase of the infection as expected, but of the tissues studied, the spleen was the main site of Fe binding. Zn tended to increase in all tissues, except in the spleen, where during the acute phase of the infection, the total content of Zn in groups L-1 and L-2 was lower than in group C. Cu increased mainly in the spleen and muscle. In general, each tissue presented its own pattern of redistribution related to its nature, functions, and number of parasites inoculated, and these patterns may have been altered by the tropism of the parasite.

Interactions among micronutrient deficiencies and undernutrition in the Philippines.

Data gathered from the 1987 National Nutrition Survey in the Philippines provided the opportunity to study the interactions among micronutrient deficiencies and undernutrition in different age groups as basis for program targeting. A randomly selected set of 50% of the households (3,200) covered by the national survey served as source of subjects. Results showed that there was a greater proportion of anemia among the undernourished (as judged by weight for age in children and weight for height in adults) (66.0%) than among the adequately nourished (54.6%) (P < 0.01). However, the observed differences in the proportion of serum vitamin A deficiency and of goiter among the undernourished compared to the adequately nourished were not significant. Also not significant were the observed higher prevalence of anemia among subjects with acceptable serum vitamin A levels for both adequately nourished and undernourished, and the higher prevalence of vitamin A deficiency among the non-anemics. Again there were no significant differences in the prevalence of anemia among goitrous and non-goitrous subjects, as well as the prevalence of goiter among anemic and non-anemic subjects. Neither were there significant differences in the prevalence of vitamin A deficiency among goitrous and non-goitrous subjects, but there were significant differences in the prevalence of goiter among vitamin A deficient and non-vitamin A deficient subjects among the 7-14 years old and among pregnant and lactating women. The study concludes that at the national level, there is apparently an interaction between anemia and protein-energy undernutrition and possibly also between goiter and vitamin A deficiency in the high-risk age groups, but between anemia on the one hand and goiter and vitamin A deficiency in the other, perhaps because of clustering in the latter conditions not found in anemia and general undernutrition. These findings may be useful in targeting communities with high prevalence of micronutrient deficiencies by using prevalence of underweight and goiter as indicators for high prevalence of anemia and vitamin A deficiency, respectively.

Non specific jejunoileitis--a report of 8 cases.

Nonspecific jejuno-ileitis is a nonocclusive, necrotizing inflammation of the small intestine. We treated 8 patients of jejuno-ileitis in a short span of 8 months. Their mean age was 8.6 years. All had acute pain in abdomen and most had hematochezia. Radiology was helpful only in diagnosis of complications of the disease. Four patients responded to conservative management; the other 4 required surgery--laparotomy and lavage in 2, and multiple laparotomies with resections in 2. One patient died due to chronic malnutrition and metabolic complications. Bowel histology was suggestive of resolving vasculitis in one patient and chronic inflammation in another patient.

[Enteral nutrition in maxillofacial surgery patients (1989-1995)]. / Nutrición enteral en los pacientes de cirugía maxilofacial (1989-1995).

One of the clearest indications for enteral nutrition is made up by patients who underwent treatment for orofacial pathology. In this way, we have reviewed retrospectively, 321 clinical histories of patients who underwent treatment (orofacial surgery), dividing these according to the pathology; neoplasia or non-neoplasia (173/148), with enteral nutrition 24 hours after the intervention. Data are collected with regard to the tolerance (vomiting, diarrhea), time needed to reach 1.500 kcal/day, need of parenteral nutritional support, transferrin, prealbumin, and albumin quantification at the start of the nutritional therapy, as well as the total duration there of. Globally, the good enteric tolerance of both groups of patients is noted, despite the fact that the oncological group showed a greater degree of protein malnutrition (statistically significant). As for the total duration of the nutrition, this is greater in the neoplasias, probably due to a more aggressive surgery. The results obtained permit modification of the basic enteral nutrition protocol (reduction of the time used to reach the maximum volume), as well as stressing the preoperative and postoperative regulated nutritional evaluation.

[An evaluation of the nutritional status of patients with chronic kidney failure on hemodialysis via rapid-turnover proteins]. / Valoración de la situación nutricional de pacientes con insuficiencia renal crónica en hemodiálisis mediante proteínas de intercambio rápido.

The evaluation of the nutritional state of patients on maintenance haemodialysis is one of the main aspects involved in the prescription of treatment, since malnutrition is frequent among these patients and is a very important risk factor. We studied the albumin levels and the levels of several rapid interchange proteins (prealbumin, transferrin, cholinesterase) in 106 patients with chronic renal failure on haemodialysis. The proteic catabolism rate (pcr) and total dose on normalized dialysis (KT/V) was also determined in these patients, in accordance with the kinetic urea model. Anthropometrical measurements were taken (dry weight following haemodialysis, skin fold of the triceps and muscular circumference of the arm) in 65 patients. The average levels of the proteins studied were within normal laboratory limits, except for albumin, which was slightly lower. The greater frequency of infranormal levels corresponded to albumin (57%); the protein least altered was prealbumin (14.7%), although 70.4% of patients showed lower levels of this protein compared to those considered as indicating a poor prognosis (30 mg/day). The estimated daily proteic intake, according to the proteic catabolism rate, was lower than the recommended rate in 58% of our patients, this was not correlated with any of the proteins studied, and was significantly lower in the group of patients whose dialysis dose was too low. Although the anthropomorphic parameters did not correlate with any protein, the average levels of prealbumin were significantly lower in patients with infranormal levels of dry weight and skin fold of the triceps. The albumin, prealbumin, transferrin and cholineserase levels were not affected by treatment with erithropoyetin, haemodialysis buffer bath or type of membrane used.