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A near infrared diffuse reflectance spectroscopy (NIRS) procedure for the quantitative control analysis of the active compound (otilonium bromide) in a pharmaceutical preparation in three steps of the production process (blended product, cores and coated tablets) and a methodology for its validation are proposed. The analytical procedure is composed by two consecutive steps. First, the sample is identified by comparing its spectrum with a second derivative spectral library. If the sample is positively identified, the active compound is quantified by using a previously established partial least squares (PLS) calibration model. The procedure was validated by studying repeatability, intermediate precision, accuracy and linearity. To this end, an adaptation of ICH (International Conference on Harmonisation) validation methodology to an NIR multivariate calibration procedure is proposed. The relative standard error of prediction (RSEP) was < or = 1% and the suitability of the procedure for control analysis was confirmed by the results obtained analysing new production samples produced over a three-month period.

Plants of Tagetes erecta L. (marigold) cultivated in vitro in ventilated containers exhibited greater control of leaf water loss and increased survival in the field than plants cultivated in sealed containers. Increased field survival of plants cultivated in ventilated containers was attributed to higher levels of endogenous abscisic acid (ABA). Therefore, ABA was supplied exogenously to plants in sealed or ventilated containers by adding ABA (10(-6), 10(-5), 10(-4) M) to the in vitro culture media in order to evaluate control of leaf water loss, growth and field survival. The addition of 10(-4) M ABA to the culture media in sealed containers produced plants that had similar control of leaf water loss and were morphologically similar to plants cultivated in ventilated containers without the addition of ABA. Field survival of 10(-4) M ABA plants (75%) was increased compared to plants cultivated in sealed containers without ABA (31%), with survival being closer to that of plants cultivated in ventilated containers (90-100%). Plants cultivated with 10(-4) M ABA (sealed and ventilated) also exhibited increased plant vigour and leaf area in the field compared to plants cultivated without ABA. The results suggest that the limited field survival and growth of plants cultured in vitro are related to the limited ABA concentrations they accumulate while in vitro. Consequently, conditions that increase the endogenous ABA concentrations of in vitro plants (like ventilation or ABA addition to the medium) would improve the control of leaf water loss, field survival and plant vigour.

A near-infrared (NIR) spectroscopic method based on the use of a fiber optical probe for the analysis of a commercially available pharmaceutical preparation is proposed. The analyte is identified by comparison with a second-derivative spectral library, using the correlation coefficient as the discriminating parameter. Once a sample has been positively identified, the active principle is quantified with partial least-squares (PLS) calibration. The proposed method was validated for use as a control method; to this end, the selectivity of the identification process, and the repeatability, intermediate precision, accuracy, linearity, and robustness of the active principle quantitation, were assessed.

Isozymatic variation and phylogenetic relationships among extant henequén (Agave fourcroydes) germplasm and wild populations of its ancestor A. angustifolia in the Yucatan Peninsula in Mexico were analyzed. Analysis of three isozyme systems using starch gel electrophoresis indicated that while A. angustifolia populations have relatively high levels of variation, within each henequén cultivar all individuals were identical. This result corresponds to previous ethnobotanical and morphological analyses, which indicated severe loss of genetic variation of this domesticated plant as a consequence of the promotion by means of asexual propagation of only one cultivar since the middle of the last century. The three extant cultivars of henequén were distinct from each other. Two of them, Sac Ki (SK) and Yaax Ki (YK), could be matched within the progenitor, but Kitam Ki (KK) has a MDH electrophenotype not found in any of the plants growing inside the Yucatan Peninsula, but found in some A. angustifolia plants growing in the Mexican states of Oaxaca and Veracruz. A parsimony analysis of the morphological data indicated two lineages: that of SK and YK, cultivated cordage plants selected for stronger and longer fibers, whose sister group is the Tropical subdeciduous forest ecotype (SF), and that of all the other wild populations, which also included KK, the cultivated textile plants selected for finer fibers and nearly extinct in Yucatan. These results support the hypothesis of the yucatecan origin of SK and YK from the SF ecotype, as well as the hypothesis of a recent introduction of KK to the Yucatan Peninsula in a domestication trend that probably included also Chelem White (its cultivation being abandoned later).

Study Objectives: To describe the age distribution, clinical, laboratory, radiographic, and bacteriologic findings of pediatric patients with tuberculous pleural effusion., Design: A retrospective study., Patients and Methods: We have identified all cases of primary pulmonary tuberculosis in children < 18 years, reported to the health department. We have collected information from medical records regarding demographics, clinical findings, bacteriologic results, and evolution. Chest radiographs obtained at the time of initial evaluation were reviewed independently by two groups of radiologists who were blind to the clinical and epidemiologic data., Results: Between January 1983 and December 1996, 175 children < 18 years were diagnosed as having primary pulmonary tuberculosis. Among them, 39 patients (22.1%) showed pleural effusion on chest radiograph. The mean age of patients with tuberculous pleural effusion was significantly higher (13.52+/-0.5 years vs 6.97+/-0.42 years). The sensitivity of the tuberculin test is 97.4% for an induration > or = 5 mm. Pleural fluid analysis shows a lymphocytic exudative effusion. Chest radiograph review showed unilateral pleural effusion in all cases. Pleural effusion was the sole radiographic manifestation in 41% of cases. Parenchymal disease is associated in 23 cases (59%). Bacteriologic confirmation of tuberculosis was achieved in 22 cases (56.4%). Cultures of pleural fluid and biopsy material both yielded Mycobacterium tuberculosis in 15 of 34 (44.1%) and 12 of 18 (66.6%), respectively, for samples under study. Pleural biopsy specimens showed granulomatous inflammation in 18 of 23 cases (78.3%). Antituberculous therapy for 6 to 9 months was effective in all cases. Transient side effects occurred in 1 of 39 patients (2.9%)., Conclusions: Pleural effusion accounts for 22.1% of cases of pediatric pulmonary tuberculosis. Parenchymal consolidation is the most common associated radiographic finding. Bacteriologic confirmation was achieved in 56.4% of cases. A short course of chemotherapy is effective.

An artificial neural network (ANN) procedure that uses the scores of a principal component model as input data was tested for calibration in the resolution of binary mixtures from kinetic measurements. The results thus obtained are compared with those provided by partial least-squares (PLS) regression and principal component regression (PCR). The ANN was first applied to simulated single wavelength kinetic curves. The effect of experimental variability was considered by assuming rate constants to fit a normal distribution curve. An amount of instrumental noise was also added to the simulated curves. Both linear and nonlinear systems were tested. Non-linearity was assumed to result from interactions between analytes and modeled by introducing a multiplicative term in the rate equation. The results provided by the three methods on linear systems were comparable; in the presence of interactions between analytes, however, the ANN method clearly outperformed the other two. The ANN method was also used to resolve mixtures of Fe(III), Co(II), and Zn(II) by displacement from their EGTA complexes with 4-(2-pyridylazo)resorcinol (PAR) using a stopped-flow injection assembly including a diode array detector. Preliminary experiments revealed the Co(II) and Zn(II) displacement reactions to be pseudo-first-order and that of Fe(III) to be a multistep process that departed from the linear behavior of the other two. Again, the results obtained with ANN were better than those provided by PCR and PLS.

We developed three analytical methods for the determination of carbohydrazide at different concentration levels. One involves the volumetric titration of the analyte with bromate ion and dead-stop end-point detection, and is applicable to concentrations above 10 mg/l., so it can be used for standardizing carbohydrazide solutions. A second, spectrophotometric method is based on the reduction of FE(III) and measurement of the absorbance of the Fe(II)-ferrozine complex, and features an applicability range of 25-700,mug/l. carbohydrazide. The third method uses differential pulse polarography and the oxidation of carbohydrazide in a basic medium at a dropping mercury electrode to determine the analyte. This last method is the most sensitive of the three and also that offering the widest determination range: from 4 to 3000 mug/l. carbohydrazide.

We studied four groups of one hundred patients older than forty years. A group with radiological signs of cervical arthrosis was statistically compared with another one without such signs. There was no significant difference between the two groups with regard to the presence of vertebrobasilar insufficiency. Then we compared one hundred patients diagnosed of vertebrobasilar insufficiency with another group without this disease. When cervical arthrosis cases in these two groups were statistically compared, we could not find any significant differences. We think cervical arthrosis is not an important etiologic factor in vertebrobasilar insufficiency. Our results point to atherosclerotic lesions as the main cause of this entity.

It has been suggested that in acute poststreptococcal glomerulonephritis, streptococcal neuraminidase may remove sialic acid from some normal plasma or tissue components, thus rendering it antigenic. We therefore investigated serum neuraminidase activity and serum and urinary free neuraminic acid levels, using the thiobarbituric acid method, in 39 patients with acute poststreptococcal nephritis. Serum neuraminidase activity was found in eight patients, and increased thiobarbituric acid-reactive material (presumed to be free neuraminic acid on the basis of absorption-spectrum similarity) was found in 28 patients. Serial determinations in 21 patients indicated that neuraminidase activity was present only initially and that free neuraminic acid levels decreased with time, usually becoming undetectable after four weeks. Determinations in patients with other renal and nonrenal diseases suggested that the findings were characteristic of poststreptococcal nephritis. Urinary neuraminic acid levels were unrelated to serum levels and were not markedly different between patients and normal subjects. These data suggest a role for neuraminidase activity in acute poststreptococcal nephritis, but they do not indicate whether it is primary or secondary.

1. The renal function changes induced by dietary protein are thought to result from the activity of hormonal factors that remain as yet undefined. Since a meat meal and high dose atrial natriuretic factor (ANF) infusions have similar effects on glomerular filtration rate, natriuresis and kaliuresis, we decided to investigate the possibility that a protein meal could stimulate ANF activity. 2. We studied 10 normal volunteers who had a fixed protein and sodium intake for 7 days before the experiments. The subjects received a meat meal (1-1.5 g of protein/kg) and, on a separate occasion, a carbohydrate meal that had a similar caloric, sodium and potassium content. Diuresis was stimulated with water ingestion, and urine collections were obtained before the meals (baseline) and after the meals for a period of 3 h. Blood samples were obtained 30 min and 5 min before the meals and every hour for 3 h in the period after the meal. 3. The protein meal, but not the carbohydrate meal, was associated with parallel increments in plasma immunoreactive ANF (i-ANF), natriuresis, kaliuresis and glomerular filtration rate (estimated from creatinine clearances) which reached peak values 2-3 h after the meal. The mean increment of plasma i-ANF after the protein meal represented a twofold increase over baseline levels. 4. We conclude that ANF may participate in the physiological response to an oral protein load.

Because renal vasodilator systems may be involved in the physiologic response to a protein meal, we studied the relationship of prostaglandin E (PGE) and kallikrein (KE) activity to the renal hemodynamic changes induced by a meat meal. Ten normal subjects on a maintenance diet providing 1 g protein per kg and 100 mmol Na daily were studied before and after a meal of 86 g of meat protein, once without medication, and again after treatment with indomethacin (150 mg daily for 3 days before and 50 mg the morning of the test). A carbohydrate meal of similar caloric, Na and K content was used in control studies. Glomerular filtration rate (GFR, inulin clearance), renal blood flow (RBF, para-aminohippurate [PAH] clearance), PGE and kallikrein urinary excretion were determined. All studies were performed during water diuresis to avoid bladder catheterization. The protein load induced an increase in GFR (ml/min, mean +/- s.e.m.: baseline 107.2 +/- 6.05, peak postmeal 146.4 +/- 6.79, p less than 0.01) and RBF (baseline 529.7 +/- 42.9, postmeal 678.9 +/- 61.9, p less than 0.05). Renal hemodynamic changes were unrelated to changes in urinary PGE and KE excretion. Indomethacin treatment inhibited PGE excretion by 73% during the test meal but did not modify the protein-induced hyperfiltration. Our results suggest that these renal vasodilator systems are not primarily responsible for the hyperfiltration response. In addition, the data show that inhibition of prostaglandin synthesis is not a practical approach to prevent glomerular hyperfiltration in clinical practice.