Specific applications of capillary electrochromatography to biopolymers, including proteins, nucleic acids, peptide mapping, antibodies, and so forth.

Separation of biopolymers is an obvious application of capillary electrochromatography (CEC) technology, since speed and resolution should increase significantly over high-performance liquid chromatography (HPLC). All too often, HPLC chromatograms of polymers show poorly resolved envelopes of overlapping peaks from oligomers. The practical limitation of column length and pressure drop has hindered development of high resolution separations of many polymers in HPLC. However, this generally applies only to packed beds of small particles, and not to continuous (or monolithic) beds, as introduced by Hjerten et al. [S. Hjerten, Ind. Eng. Chem. Res. 38 (1999) 1205; S. Hjerten, C. Ericson, Y.-M. Li, R. Zhang, Biomed. Chromatogr. 12 (1998) 120; C. Ericson, S. Hjerten, Anal. Chem. 71 (1999) 1621; J.-L. Liao, N. Chen, C. Ericson, S. Hjerten, Anal. Chem. 68 (1996) 3468; S. Hjerten, A. Vegvari, T. Srichaiyo, H.-X. Zhang, C. Ericson, D. Eaker, J. Capillary. Elec. 5 (1998) 13; C. Ericson, J.-L. Liao, K. Nakazato, S. Hjerten, J. Chromatogr. A 767 (1997) 33; S. Hjerten, D. Eaker, K. Elenbring, C. Ericson, K. Kubo, J.-L. Liao, C.-M. Zeng, P.-A. Lidstrom, C. Lindh, A. Palm, T. Srichiayo, L. Valtcheva, R. Zhang, Jpn. J. Electroph. 39 (1995) 1]. Throughout this review we will refer to such packings as monolithic or continuous beds, but they are identical type packings, formed by the in situ polymerization in the capillary or column. CEC capillaries can be much longer, and contain smaller particles than is practical for HPLC. This improves resolution significantly. CEC is able to capitalize on existing mobile phase technology developed over 30 years to improve separations. The requirement that the mobile phase simultaneously promote the separation and mobile phase mobility needs to be considered. In RPLC, this dual role is not much of a problem. It may be much more important in other modes, particularly ion-exchange (IEC). As the field develops, it is becoming clear that CEC is not just a simple extension of HPLC. Instruments, column technology and operating optima are clearly different than HPLC. CEC will develop into its own unique field. Open tubular HPLC is almost precluded by the high pressures required for forcing liquids through 10 microm or smaller capillaries. Electroosmotic pumping (EOF) avoids the pressure constraints and provides better flow profiles. Compared to HPCE, the ability to interact with the stationary phase may enable separations that would be difficult with electrophoresis alone. Since the mobile phase can be less complex than micellar electrokinetic chromatography (MEKC), CEC also avoids the problem of high background signals from the micelle forming compounds. Thus CEC-MS (mass spectrometry) is expected to be even more powerful than HPCE-MS. The fortuitous, simultaneous development of matrix assisted laser desorption-time of flight MS (MALDI-TOF-MS) technology will enable extension of the mass range to above 100 000 Da. Lack of familiarity is the perhaps the largest liability of CEC compared to other techniques. This paper critically compares the state-of-the-art of CEC with HPLC and HPCE, with a particular emphasis on separation of biopolymers. The goal is to help the reader overcome the fear of the unknown, in this case, CEC.

[Ultrasonic study of gallbladder motility during exclusive continuous enteral feeding]. / Etude échographique de la motricité vésiculaire au cours de l'alimentation entérale continue exclusive.

Total parenteral nutrition may be responsible for gallbladder sludge and lithiasis which might possibly be related to gallbladder bile stasis. Gallbladder motility has not yet been studied during constant-rate enteral nutrition. We performed serial ultrasonographic studies of gallbladder volume and contents in ten patients receiving constant-rate enteral nutrition during 35 +/- 17 days. Each patient had two weekly examinations at 9 AM and 2 PM on the same day. None of the patients developed gallbladder sludge or lithiasis. The gallbladder was frequently seen to be contracted. Mean gallbladder volume during constant-rate enteral nutrition was not significantly different from mean gallbladder volume after Bladex. Individual gallbladder volume changed significantly from one measurement to another. This study showed that gallbladder motility is preserved during constant-rate enteral nutrition. The persistence of gallbladder contractions may prevent the development of biliary sludge ad lithiasis.

[Human pentastomiasis: clinical, radiological and x-ray computed tomographic study of a case]. / Pentastomose humaine: étude clinique, radiologique et tomodensitométrique d'un cas.

A case of abdominal pentastomiasis in a 38-year-old Congolese man is reported. This parasitic disease has been described in Central Africa and South East Asia. The patient presented with unexplained permanent abdominal pain. The peritoneal and hepatic localisations of the parasite were recognized on plain abdominal film and documented by ultrasonography and CT scan studies. At laparoscopy multiples adherences were found, in spite of the fact that no previous abdominal surgery had been performed. These findings suggest a possible correlation between the clinical manifestations and the anatomic lesions in this disease which is usually considered to be asymptomatic.

[Psoas abscess complicating Crohn's disease]. / Abcès du psoas compliquant la maladie de Crohn.

Psoas abscess were found in 6 cases among 166 patients with Crohn's disease between 1985 and 1989; in one case, it was the first sign of Crohn's disease. Diagnosis was usually difficult and should be suspected on the following signs: lower abdominal quadrant pain, psoitis, abdominal mass, sciatica or pain along the course of the femoral nerve. Diagnosis was confirmed in nearly all cases by computerized axial tomography. Effective therapy combines drainage and bowel resection.

[Gastrointestinal tract in the elderly]. / Radiologie digestive de la personne âgée.

Patient's age no longer is a major factor when discussing the diagnosis and treatment of hepatobiliary and gastrointestinal diseases. However, discussing with the physician in charge of the patient is the only adequate way to propose the quickest, least invasive and most comfortable imaging modality that will give a proper answer to the clinical problem. Cross sectional imaging, especially ultrasound, CT and in some cases MRI, plays an important role in the diagnosis of these diseases.

[Inflammatory rheumatic disorders during the course of secondary syphilis (author's transl)]. / Le rhumatisme inflammatoire de la syphilis secondaire.

A 46-year-old man presented signs of secondary syphilis, including a skin eruption, multiple adenopathies, and alopecia. The diagnosis was confirmed by positive serological and Nelson's tests. Inflammatory arthritic signs developed in a few joints two weeks after the onset of the skin eruption, affecting mainly the left wrist, right sternoclavicular joint, lumbar spine, and right shoulder and hip joints, which were painful and stiff. Tests for a rheumatic origin, especially urethral smears and HLA B27 antigen, were negative. The articular manifestations disappeared completely after 8 to 10 days of penicillin. Rheumatic disorders from secondary syphilis affect one or several of the large joints, and quite frequently the sternoclavicular joints, the clinical, radiological, and biological characteristics showing no particular features. Diagnosis is based on the exclusion of other causes for the rheumatic disorder, total rapid regression after penicillin alone, and the simultaneous appearance of the affections.

Aneurysmal dilatation of the portal vein: a case diagnosed by real-time ultrasonography.

A case of aneurysmal dilatation of the portal vein is reported. A real-time ultrasound study showed a cystic mass behind the pancreatic head, freely communicating with the lumen of the portal, superior mesenteric, and splenic veins, which was diagnostic of portal vein aneurysm. The diagnosis was confirmed by dynamic computed tomography and celiac and superior mesenteric angiograms.

Conformation and configuration of tertiary amines via GIAO-derived (13)C NMR chemical shifts and a multiple independent variable regression analysis.

The (13)C chemical shifts of six tertiary amines of unambiguous conformational structure are compared to predicted (13)C NMR chemical shifts obtained via empirically scaled GIAO shieldings for geometries from MM3 molecular mechanics calculations. An average deviation, absolute value of Deltadelta(av), of 0.8 ppm and a maximum deviation, absolute value of Deltadelta(max), of 2.8 ppm between predicted and experimental (13)C shifts of the six tertiary amines of unambiguous structure are found. In several cases of tertiary amines subject to rapid exchange, where experimental (13)C shifts at room temperature are weighted averages of multiple conformers, a comparison of calculated (13)C shifts of all reasonable MM3 predicted conformers with experimental (13)C shifts via a multiple independent variable regression analysis provides an efficient method of determining the major and minor conformers. The examples presented are 2-methyl-2-azabicyclo[2.2.1]heptane and 1,6-diazabicyclo[4.3.1]decane, which each have two expected contributing structures, and 2-(diethylamino)propane and 1,8-diazabicyclo[6.3.1]dodecane, where ten and seven low-energy conformers, respectively, are predicted by MM3 calculations.

Conformational studies on (17alpha,20Z)-21-(X-Phenyl)-19-norpregna-1, 3,5(10),20-tetraene-3,17beta-diols using 1D and 2D NMR spectroscopy and GIAO calculations of (13)C shieldings.

Differences in agonist responses of the novel estrogen receptor ligands (17alpha,20Z)-(p-methoxyphenyl)vinyl estradiol (1), (17alpha, 20Z)-(o-alpha,alpha,alpha-trifluoromethylphenyl)vinyl estradiol (2), and (17alpha,20Z)-(o-hydroxymethylphenyl)vinyl estradiol (3) led us to investigate their solution conformation. In competitive binding assay studies, we observed that several phenyl-substituted (17alpha, 20E/Z)-(X-phenyl)vinyl estradiols exhibited significant estrogen receptor binding, but with variation (RBA (1) = 20; RBA (2) = 23; RBA (3) = 140 where estradiol RBA = 100) depending on the phenyl substitution pattern. Because the 17alpha-phenylvinyl substituent interacts with the key helix-12 of the ligand binding domain, we considered that differences in the preferred conformation of 1-3 could account for their varying binding affinity. 2D NMR experiments at 500 MHz allowed the complete assignment of the (13)C and (1)H spectra of 1-3. The conformations of these compounds in solution were established by 2D and 1D NOESY spectroscopy. A statistical approach of evaluating contributing conformers of 1-3 from predicted (13)C shifts correlated quite well with the NOE data. The 17alpha substituents of 1 and 2 exist in similar conformational equilibria with some differences in relative populations of conformers. In contrast, the 17alpha substituent of 3 exists in a different conformational equilibrium. The similarity in solution conformations of 1 and 2 suggests they occupy a similar receptor volume, consistent with similar RBA values of 20 and 23. Conversely, the different conformational equilibria of 3 may contribute to the significant binding affinity (RBA = 140) of this ligand.

[Plasma cell granuloma in the lung and mediastino-pulmonary sarcoid lesions (author's transl)]. / Granulome plasmocytaire du poumon et lésions sarcoïdiennes médiastino-pulmonaires.

The authors report a case of inflammatory plasma cell pseudo-tumor in the lung associated with mediastino-pulmonary sarcoid histological lesions. Diffusion of the latter to pulmonary parenchyma, the intensity of the follicular reaction in mediastinal lymph nodes together with a positive Kveim test suggest the fortuitous association of a mediastinal-pulmonary sarcoidosis with a plasma cell granuloma.