Enantioseparation of derivatized amino acids by capillary isoelectric focusing using cyclodextrin complexation.

Enantioseparation of dansylated as well as 6-aminoquinolyl-N-hydroxysuccinimidylcarbamate (AQC)-derivatized amino acids by means of capillary isoelectric focusing using various cyclodextrin derivatives is demonstrated. Separation is based on the enantioselective shift of the isoelectric points upon complexation with the chiral selectors. The zwitterionic, diastereomeric analyte-cyclodextrin complexes exhibited differences in the pI values up to more than 0.25 pI units. Enantioresolution was achieved for a number of derivatized amino acids and various selectors added to the carrier ampholyte solution. The hydroxypropyl-beta-cyclodextrin proved to be the best selector for this purpose. Enantioseparation as dependent on the selector concentration was evaluated in a range between 5 and 30 mM. Separation could be attained down to selector concentrations corresponding to a degree of complexation as low as 30%. The peaks appear according to the degree of complexation between the positions adopted without and with full complexation. The kinetics of complex formation and dissociation was fast enough in most instances to produce single peaks, even with complexation degrees near 0.5 and significant pI shifts. Peak widths were slightly enlarged in these instances. The method offers excellent perspectives for preparative applications.

pKa shift-associated effects in enantioseparations by cyclodextrin-mediated capillary zone electrophoresis.

Enantioselective migration of dansylated (Dns) amino acids in the presence of hydroxypropylated-beta-cyclodextrin under acidic conditions near the pI value of the analytes was investigated by means of capillary zone electrophoresis. Based on the migration data, the pH dependence of the complexation constants was evaluated, as well as the variation of the complex mobilities with pH. As a result of these data, the migration behavior in the pH region near the pI could be understood, which, in some instances, includes the reversal of migration order upon variation of selector concentration. The enantioselective pKa shifts upon complexation could be quantitated for the carboxylic and the amino group separately. pKa shifts were found in the order of 0.8 pI units, the differences between the enantiomers being up to 0.25 pH units. These data were in agreement with the pI shifts reported from isoelectric focusing experiments. The accurate determination of the pI values of the Dns amino acids makes it possible to calibrate the pI scale in isoelectric focusing in the presence of chiral selectors.

Screening for breast cancer: report of a population-based experience in the city of Milan, Italy.

AIMS AND BACKGROUND: Mammographic screening is recommended as a current health practice. The aim of the present study is to report the results of a new program which started in the city of Milan in 1989. METHODS: A total of 4882 women aged 50 to 61 years and resident in quarter no. 16 of Milan were invited by mail to attend the screening at the San Paolo Hospital based on two-view mammography and physical examination. RESULTS: A total of 2953 (60.5%) women attended the first screening round, and 18 cancers were detected (1 Tis, 8 T1, 9 T2). The detection rate was 6.9 x 1000, and the prevalence/incidence ratio was around 3.5. CONCLUSIONS: The study confirms the feasibility of breast cancer screening in an urban setting by using the existing general hospital facilities and should be considered as a possible model for other urban experiences.

Determination of D-alanine and D-glutamic acid in biological samples by coupled-column chromatography using beta-cyclodextrin as mobile phase additive.

A high-performance liquid chromatographic assay for monitoring traces of D-alanine and D-glutamic acid in peptide and protein hydrolysates is presented, which uses a two-column set-up with column switching. The main advantage of the proposed method is the higher reliability of the results, compared with the analysis by derivatization and single-column chromatography of the diastereomers. A non-chiral alkyl-silica reversed-phase column is combined with a second column, in which beta-cyclodextrin is used as a chiral mobile phase additive. The amino acids of the hydrolysate are dansylated, and the amino acid of interest is separated from the others on the first column and transferred to the second column where chiral resolution is performed. The transfer volume of ca. 200 microliters is small enough not to cause any peak distortion or dilation in the second column.

[Contribution to the study of "wet lung". Radiological and clinico-functional changes induced by depletion therapy in 5 patients with chronic bronchopulmonary disease]. / Contributo alla conoscenza del "polmone umido". Modificazioni radiologiche e clinico-funzionali di cinque pazienti broncopneumopatici cronici indotte dalla terapia depletiva.

The Authors consider the global evaluation of clinical and functional data in patients with the following radiological features: 1) X-ray thoracic aspects characterized by marked broncho-vascular bundles and diffusion of reticular nodulation as in diffuse interstitial pulmonary fibrosis; 2) lack of ECG and clinical signs of heart failure. Since a reversibility of radiological alterations was considered a favourable reply to bleeding and diuretic acute and long term therapy the Authors suggest that these patterns should be related to a different distribution of hydric and haematic masses with a decreasing of interstitial pulmonary oedema which contributes to a full interlobar septa like "D" lines shadows, according to Kreel, (1975). The Authors, moreover, relate these clinical, functional and radiological aspects to the patterns of "wet lung" distinguished from the cardiac lung caused by congestive heart failure and from interstitial lung fibrosis.

[Clinico-radiological and functional aspects of respiratory syndromes caused by collagen diseases]. / Considerazioni sui rapporti clinico-radiologico-funzionali nelle sindromi respiratorie da collagenopatie

The clinical and radiological features in 100 patients with collagen diseases (rheumatoid arthritis, lupus, sclerodermia, dermatomyositis, and panarteritis nodosa) were compared with respiratory performance. 56 patients were drawn from the series of Pende et Al. and 44 from a personal series. The results are set out in tables and graphs. It was found that lung lesions due to collagen disease have no special clinical and radiological features. Respiratory performance is that of a restrictive syndrome that gradually progresses from A.R. to E.S., S. and P.M., accompanied by obstruction of the large airways, as shown by hyperinsufflation in sclerodermia and reduced specific conductance in rheumatoid arthritis.