Determination of the new aromatase inhibitor CGS 16 949 in biological fluids by capillary gas chromatography/mass spectrometry

A specific and sensitive gas chromatographic/mass spectrometric method was developed and validated for the quantitative determination of the aromatase inhibitor CGS 16 949 in plasma and urine. A deuterium-labelled analogue of CGS 16 949 was used as internal standard. The analysis of spiked samples demonstrated the good accuracy and precision of the method. For both plasma and urine, the limit of quantification (LOQ: coefficient of variation (CV) = 10%) and the limit of detection (LOD: CV = 100%) were estimated to be 5 and 1 nmol l-1, respectively. The method was applied to the determination of unchanged CGS 16 949 in plasma and urine of a healthy volunteer orally dosed with 1 mg of CGS 16 949 A.

Pharmacokinetics of the angiotensin converting enzyme inhibitor benazepril.HCl (CGS 14 824 A) in healthy volunteers after single and repeated administration

The pharmacokinetics of the new angiotensin converting enzyme (ACE) inhibitor benazepril.HCl were evaluated in healthy male volunteers. The single dose kinetics were established from data of 62 subjects receiving an oral 10 mg dose of the drug. The steady state kinetics were investigated in 15 subjects after once-daily oral doses of 5, 10 or 20 mg. The compound is a prodrug which, on absorption, is hydrolysed to the pharmacologically active metabolite benazeprilat. Thus, plasma concentrations and urinary excretion of parent compound and active metabolite were determined. Benazepril.HCl was rapidly absorbed (tmax = 0.5 h) and rapidly eliminated from plasma (t1/2 = 0.6 h). Only trace amounts were excreted unchanged in urine. The drug was rapidly metabolized to benazeprilat (tmax = 1.5 h). The elimination of the metabolite from plasma was biphasic. About 80 per cent of benazeprilat formed was eliminated within 24 h (t 1/2 = 2.7 h), whereas the terminal phase (t1/2 = 22.3 h) controlled a minor amount of elimination. About 17 per cent of dose was excreted in the 24-h urine as benazeprilat. The drug disposition did not change during repeated oral dosing and only small accumulation of the metabolite occurred. The accumulation ratio was 1.20 for AUC and 1.24 for urinary excretion. The effective half-life for accumulation was estimated at about 10-11 h. The comparison with other ACE inhibitors showed similarities but also marked differences with respect to the drug kinetics and excretion.

Pharmacokinetics of a new angiotensin-converting enzyme inhibitor, benazepril hydrochloride, in special populations

To investigate the pharmacokinetics of benazepril hydrochloride in special populations, single or multiple doses between 5 and 20 mg of the new drug were given, and the pharmacokinetics of unchanged benazepril and its pharmacologically active metabolite benazeprilat were compared with those in healthy male volunteers. In elderly subjects and patients with mild and moderate renal insufficiency, there was little change in the kinetics of benazepril or benazeprilat. In patients with severe renal impairment (creatinine clearance less than 30 ml/min), benazeprilat elimination was slowed, which resulted in greater accumulation after repeated dosing. In patients with hepatic cirrhosis, the kinetics and bioavailability of benazeprilat were not affected. Therefore dose adjustment is unnecessary because of the patient's age, mild or moderate renal impairment, or hepatic cirrhosis. Dose reduction is necessary in patients with creatinine clearance less than 30 ml/min.

Firing without fear. Heading off litigation in employee terminations

Under most state laws, employee handbooks carry the status of employment contracts, or such contracts are implied through various employment conversations. Unlike in the past, when a management decision to discharge an employee could be challenged only for statutory or public policy reasons, today's employer may have to prove that he or she did not violate an employee's contractual right to employment. Employers can reduce the risk of employment liability through practical steps such as careful monitoring and documenting of the hiring, performance appraisal, and disciplinary processes, and a credible grievance procedure. Many employers have found, however, that taking these steps does not always prevent litigation. Certain legal precautions, such as written disclaimers and other handbook revisions, can result in the dismissal of such actions before trial and will deter many plaintiffs' attorneys from taking the case. The strongest legal protection in termination situations is a release of all claims executed by the employee and supported by severance pay or other valuable consideration to which the employee would not be otherwise entitled.

Specific aspects of depressed skull fractures in childhood

From 1971 to 1982, 35 children with a depressed skull fracture (d.s.f.) were observed. Their data are used to trace specific aspects of aetiopathogenesis, characteristics, clinical picture, treatment and prognosis of d.s.f. in childhood and to propose guidelines for treatment and follow-ups. The most important causes were falls and road accidents. Celluloid ball fractures were observed mainly in infants and green-stick fractures in toddlers and schoolchildren, and the clinical diagnosis was possible in 70%. Skull defects following surgery did not change their size beyond the age of 1 year and should be covered as soon as possible. The outcome of mild d.s.f. is good, in d.s.f. with contusion the outcome depends on the severity of brain trauma, mental retardation and/or posttraumatic epilepsy being the most important sequels. The latter and mild types of d.s.f. with early seizures, dural tear or residual skull defects need further follow-up; EEG recordings are of some interest.

Characterization of vacuolar polypeptides of barley mesophyll cells by two-dimensional gel electrophoresis and by their affinity to lectins

Vacuoles were isolated from primary leaves of barley (Hordeum vulgare L.) by mechanical breakage of protoplasts, and their polypeptide composition analyzed by two-dimensional gel electrophoresis. Vacuoplasts which consist of the vacuole, a portion of the plasmalemma and of the cytoplasma were prepared from protoplasts by ultracentrifugation. By comparing the vacuolar polypeptide pattern with polypeptide patterns of isolated chloroplasts and of vacuoplasts, vacuolar polypeptides could clearly be distinguished from polypeptides derived from cross-contaminating cell compartments. At least 14 polypeptides of apparent molecular mass between 12 and 76 kilodaltons and an isoelectric point between 4.5 and 7.6 could be attributed to the tonoplast fraction of the vacuole, and 35 polypeptides to the soluble fraction of the vacuole. Several lectins with different specificity were employed to characterize the degree and nature of glycosylation of vacuolar polypeptides. Concanavalin A bound to a large number of polypeptides. Three out of the 14 tonoplast polypeptides exhibited detectable carbohydrate moieties and almost two-thirds of the surveyed soluble polypeptides were glycosylated.

Determination of the S(+)- and R(-)-enantiomers of baclofen in plasma and urine by gas chromatography using a chiral fused-silica capillary column and an electron-capture detector

A sensitive and enantiospecific gas chromatographic method for the determination of the S(+)- and R(-)-enantiomers of baclofen (I and II) in plasma and urine has been developed and validated. The method is based on the complete resolution of the derivatized enantiomers on a chiral fused-silica capillary column. The hydrochloride salt of a (-)-fluoro analogue of baclofen (III.HCl) was used as the internal standard in plasma, the hydrochloride salt of a (+)-fluoro analogue of baclofen (IV.HCl) as the internal standard in urine. Rapid and convenient isolation of the compounds was achieved using reversed-phase Bond-Elut C18 columns. After elution, the compounds were converted into isobutyl esters and purified by base-specific solvent extraction. The isobutyl esters were then N-acylated with heptafluorobutyric anhydride. The derivatives were quantitated after separation on the chiral column using electron-capture detection. The analysis of spiked plasma and urine samples demonstrated the good accuracy and precision of the method, with limits of quantitation of 25 nmol/l for I and II in plasma and of 2 mumol/l for I and II in urine. The method appears to be suitable for use in pharmacokinetic studies of the enantiomers in plasma and urine from animals and man after administration of the racemic baclofen.

Interaction between furosemide and the converting enzyme inhibitor benazepril in healthy volunteers

Single oral doses of 10 mg converting enzyme inhibitor benazepril (CGS 14824A) and 40 mg furosemide were administered to 12 healthy male volunteers either separately or concomitantly. The pharmacokinetic parameters of benazepril were not influenced by coadministration of furosemide. Urinary excretion of total furosemide was significantly reduced by 10 to 20% in the presence of benazepril. This effect was considered clinically insignificant. Erect blood pressure decreased and pulse rate increased only during concomitant treatment.

Sagittal synostosis--its clinical significance and the results of three different methods of craniectomy

From 1973 to 1986, 50 infants with sagittal synostosis have been operated by three different methods of craniectomy (linear craniectomy and extended craniectomies, as proposed by Schut and Epstein et al.). Preoperatively, the mean cephalic index was 67 +/- 4, 35.5% had clinical findings as cerebral palsy, psychomotor retardation and/or neurological signs, and intraoperatively the epidural pressure was more than 200 mm H2O in 60% (recorded in the last 20 patients). The mean follow-up time was 4.7 (1-10.6) years. Postoperatively, only 14.5% had minor clinical signs, which were mostly not in relation to the former scaphocephaly. Half of the patients with increased ICP had clinical signs preoperatively, and none of the 20 patients had distinct findings postoperatively. Out of the 20 children operated on by linear craniectomy or by Schut's method up to 1980, two-thirds had no school problems and one-third some school problems; one-third had occasionally headaches and one-quarter ametropia. Concerning the aesthetic results, Epstein's method and, somewhat less Schut's method, were superior to linear craniectomy, as verified by craniometry and by the tracings of the outlines of the neurocranium 0.4-0.7 and 1.6-2.0 years postoperatively: mean cephalic indices 73 +/- 5 (normal in one-fourth), 74 +/- 7 (normal in half) and 79 +/- 4 (normal in nearly all patients). Epstein's method is superior to the other two methods because it renders it possible to increase the breadth the greatest during the period of greatest postnatal brain growth. In addition to the effect on the neurocranium, the extended craniectomies add to normalization of the base of the skull (in contrast to the natural history of scaphocephaly). In the long run, the results obtained remain the same. The disadvantage of residual skull defects (approximately 11% of the patients with extended craniectomies) can be avoided by performing surgery prior to 4-6 months of age or by preserving the removed bone in a deep-freeze for a limited time.

Production and ELISA application of bispecific monoclonal antibodies against fluorescein isothiocyanate (FITC) and horseradish peroxidase (HRP)

Hybrid hybridomas producing bispecific monoclonal antibodies reacting with both horseradish peroxidase (HRP) and fluorescein isothiocyanate (FITC) were obtained by fusing two hybridoma lines and selecting the fused cells using a fluorescence activated cell sorter (FACS). FITC was used to label different monoclonal antibodies and the bispecific antibodies acted as a linking agent between FITC-labelled antibody and the marker enzyme HRP. This system was used in enzyme immunoassays for the detection of different antigens. The results suggest a wide application of bispecific anti-FITC/anti-HRP antibodies as a detection system in EIA.

The production and radioimmunoassay application of monoclonal antibodies to fluorescein isothiocyanate (FITC)

Monoclonal antibodies (MoAbs) were produced against the fluorescence marker fluorescein isothiocyanate (FITC). FITC was used as a hapten to label different proteins and the anti-FITC MoAbs were used to identify these labelled proteins in a solid-phase radioimmunoassay and in cellular radioimmuno-binding assays for the demonstration of antigens and antibodies.

[Congenital hydrocephalus. A multicenter retrospective longitudinal study of newborn infants treated with shunts 1976-1985]

A multicentric retrospective evaluation of 54 children was performed who were born between 1976 and 1985 with a clinically recognisable hydrocephalus and thereafter shunted. The 4 topics of the study included: 1) Analysis of pregnancy, antenatal diagnostic procedures and parturition, 2) Preoperative evaluation and intraoperative findings, 3) Long-term follow-up and 4) Prognosis (actual status) of the 45 surviving patients at the end of the study (May 1987). Patients with neonatal hydrocephalus were observed in 11% of all children shunted during the same time in the hospitals included in this study. During this period the incidence of new cases did not decrease.

[Congenital hydrocephalus--initial status (prognosis) of congenital hydrocephalus]

Only 1/4-1/3 of the surviving patients have severe neurological findings, are continuously treated with anticonvulsives and/or have a severe mental retardation; the same number of school children is totally dependent on nursing and ineducable. All patients remain shunt-dependent. A few prognostic pointers can be obtained from the aetiology of hydrocephalus, from the occurrence of perinatal pathology and from the head circumference at birth. In cases with a head circumference of more than 45 cm shunting should be performed beyond the neonatal period only for nursing reasons.

Comparative study of alloimmune reactions induced by leukocyte and platelet transfusions in humans: characteristic changes of activation markers, gamma interferon, and FcR blocking antibody production

This study was undertaken to define immune responses induced by leukocyte and platelet transfusions. We offer evidence that activation by alloimmunization with intravenously administered "buffy coat" cells results in immune alterations similar to the early rejection episodes following kidney transplantation. Thus, IL-2 and HLA-DR expression increased on PBL 2 and 3 days after antigen exposure and paralleled elevations of IFN-gamma, neopterin, and beta 2 microglobulin levels. No significant changes were detected in the number of T-cell subpopulations. Alloimmunization by purified platelets alone that express only class I MHC antigens failed to induce the above alteration, even after repeated exposure. Repeated alloimmunization with "buffy coat" cells or isolated platelets stimulated a progressive increase up to 100% blocking activity on EA rosette formation. We conclude that the expression of activation markers on PBL and the production of IFN gamma and neopterin reflect the early phase of alloimmune response induced by leukocytes. This type of alloactivation is not a prerequisite for the development of FcR-blocking antibody, which is produced after pure platelet transfusion as well.

Determination of a new angiotensin converting enzyme inhibitor and its active metabolite in plasma and urine by gas chromatography-mass spectrometry

A specific and sensitive gas chromatographic-mass spectrometric method for the simultaneous quantification of unchanged 3-[( 1-ethoxycarbonyl-3-phenyl-(1S)-propyl]amino)-2,3,4,5-tetrahydro-2-oxo-1- 1-(3S)-benzazepine-1-acetic acid (I) and its active metabolite, the dicarboxylic acid (II), in plasma and urine has been developed and validated. 2H5-labelled analogues of I and II were used as internal standards. The compounds were isolated from plasma and urine under acidic conditions using XAD-2 resin or Extrelut 1 columns. Following derivatization with diazomethane, the samples were analysed by packed-column gas chromatography-electron-impact mass spectrometry with selected-ion monitoring. The analysis of spiked plasma and urine samples demonstrated the good accuracy and precision of the method, which is suitable for use in pharmacokinetic and bioavailability studies with the new angiotensin converting enzyme inhibitor prodrug I.HCl in humans.

Diagnosis of diseases of the lumbar spine: correlation of computerized tomography with myelography and clinical findings

Data from 339 patients referred for evaluation of suspected lumbar disease were studied retrospectively to correlate findings in the routine clinical evaluation with results of computed tomography and myelography. Clinical features from the patients' history that correlated with an abnormal CT and myelogram included age greater than or equal to 40, a history of previous surgery, and absence of a history of injury. Signs from the physical examination that correlated included reduced lumbar motion, a motor or sensory deficit, abnormal reflexes, and reduced capacity for straight leg-raising or walking. Using a clinical score incorporating these variables, we suggest a diagnostic strategy to promote more efficient and selective use of CT scans and myelograms. We project that the use of this diagnostic approach can reduce the number of myelograms ordered in a similar population by more than 50%.

[The importance of thermography in the diagnosis of lumbar radicular pain syndromes]

This study proved the existence of lateral differences in thermographic recordings of the legs of 83 out of a total of 84 patients with the clinical diagnosis "lumbar disk herniation". In 68.5 per cent only of 71 patients with unilateral symptoms, however, the hypothermic areas occurred in the symptomatic leg. These areas could not be matched with corresponding dermatomas. As regards determination of the level of the herniation, thermography is an unreliable method for differentiation between the different segments, because the site of the dermatoma cannot be identified in relation to the site of the herniation. The mechanism of difference in temperature distribution probably depends on sympathetic reflexes with increased activity in the vasoconstrictor system due to pain. These reflexes are not limited to one dermatoma. This has been confirmed by means of diagnostic nerve blocks of the appropriate root.

Polypeptide pattern and enzymic character of vacuoles isolated from barley mesophyll protoplasts

Intact chloroplasts and vacuoles were isolated from mesophyll protoplasts of barley. The chloroplasts occupied about 15% of the cellular volume and contained 75% of the protein, whereas the vacuoles occupied about 80% of the volume and contained less than 4% of total cellular protein. Contamination of the vacuolar fraction by foreign protein is included in these values. Chlorophyll was absent from the vacuolar fraction, but less than 1% of several extra-vacuolar marker proteins were still present. The vacuoles contained hydrolytic enzymes. Several of them (α-mannosidase, α-galactosidase, N-acetylglucosaminidase) were soluble, whereas part of the activity of others semimented with the tonoplasts during centrifugation. Attached proteins could be released from the membranes during freezing in the presence of NaCl. One-dimensional gel electrophoretic separation of soluble vacuolar proteins under non-denaturing conditions yielded more than 10 protein bands. A comparative analysis was performed of thylakoids and vacuoles which were subfractionated into tonoplasts and soluble vacuolar constituents. Sodium dodecyl sulfate gel electrophoresis separated about 15 polypeptides of the soluble fraction which reacted with silver reagent. The tonoplast fraction yielded about 20 bands. A similar number of bands was observed when vacuoles incubated with the (14)C-labelled SH-reagent N-ethylmaleimide were analysed for radioactive polypeptides. Silverstaining of the polypeptides and their SH-content did not correlate. Several polypeptides of the vacuolar fraction had molecular weights very similar to the molecular weights of known chloroplast proteins. However, with the exception of the two subunits of ribulose-1,5-bisphosphate carboxylase, contamination of the vacuolar fraction by chloroplast proteins could be ruled out as a possible cause of the close correspondence. The lipophilic carboxylic-group reagent N,N'-dicyclohexylcarbodiimide ([(14)C]DCCD) reacted with several polypeptides of thylakoids and tonoplasts. However, the labelling patterns were different. The most heavily labelled polypeptide of thylakoids was the 8-kDa polypeptide of the basal part of the coupling factor CF0. Tonoplast polypeptides heavily labelled with [(14)C]DCCD had molecular weights of 24, 28, and 56 kDa. The vacuolar 8-kDa polypeptide remained unlabelled.