[Development of a spacer for inhaled corticosteroid. Evaluation using flunisolide metered dose aerosol]

As optimal therapy with inhaled steroids invariably demands the use of a spacer (Nolte, 1989), a specific inhalation device adapted to flunisolide metered dose inhaler was required. For this purpose, various inhalation chambers varying in geometry and material were investigated. The decisive criterion was the percentage of inhalable particles (diameter less than 8 microns) dispensed by the device. Separation of larger particles was possible in spacers with a relatively small volume. The highest dispensing rate being achieved with conical or pear-shaped inhalation chambers. An increase in spacer volume beyond 320 ml failed to improve the percentage of inhalable active substance. The results demonstrate that the spacer, dimensioned to the smallest possible volume, specially developed for Inhacort MDI has optimal dispensing characteristics for flunisolide.

Morphologic and flow cytometric analysis of circulating megakaryoblasts in chronic myeloid leukaemia

The immunophenotype (a), ultrastructural features (b) and cell kinetics (c) of circulating megakaryoblasts have been studied in two cases of pure megakaryoblastic and one case of mixed (myeloblastic, megakaryoblastic) cell proliferation in chronic myeloid leukaemia (CML). (a) The blast cells showed early megakaryocyte differentiation antigen (HLA-DR), platelet specific GpIIIa (CD61) and GpIIb-IIIa (CD41) antigens in different percentages. (b) The megakaryoblasts were recognized by the presence of platelet GpIIIa (CD61) demonstrated by an immunoelectron microscopic method. The labelled cells were "lymphocyte-like" megakaryoblasts and cells with features of cytoplasmic maturation (demarcation membranes, alpha granules and vacuoles). (c) Cellular DNA content of the megakaryoblasts was measured by propidium iodide (PI) staining of cells expressing platelet GpIIIa (CD61). Flow cytometric (FC) DNA analysis revealed no aneuploidy and high ploidy (greater than 4N) cell population. In the two cases of pure megakaryoblastic proliferation a high percentage of the megakaryoblasts were in the S-phase, while the non-megakaryoblastic cell fraction showed no elevated S-phase compartment. It is concluded that in CML the circulating megakaryoblasts (1) have a nuclear maturation arrest and accumulation at the level of tetraploid DNA content, (2) surface antigen expression and cytoplasmic organelles show a tendency to mature and (3) in pure megakaryoblastic proliferation the myeloid cells are not in the cell compartment showing high proliferation.

Rapid and slow benzbromarone elimination phenotypes in man: benzbromarone and metabolite profiles

Following oral administration of the uricosuric drug benzbromarone two major metabolites appear in the circulation. 1'-hydroxy-benzbromarone (M1), and a second product (M2) of unknown structure. The plasma concentrations of the parent drug and of M1 and M2 have now been compared in two different elimination phenotypes. 10 subjects who eliminated the drug rapidly (S1-10) and one individual (S11) whose elimination capacity was impaired, presumably due to genetic variation (S11). The AUC (0-96) of the parent drug in S11 was 145 micrograms.ml-1 h. and in the other individuals it averaged 18.3 (11.4-24.5) micrograms.ml-1 h. The plasma elimination half life of benzbromarone was 3.34 (1.77-5.24) h in the rapid eliminators, and 13.08 h in the subject with the elimination defect. The mean plasma elimination half life of the metabolites in S1-10 amounted to 20.1 (11.9-41.2) h for M1, and 17.2 (12.9-30.7) h for M2. In S11 the plasma elimination half life of M1 was prolonged to 76.6 h, and of M2 to 75.4 h. Thus, the elimination defect in S11 was not restricted to the parent drug, but it also involved the two major metabolites M1 and M2. This might be a consequence of a hepatic enzyme deficiency, or be due to impairment of drug excretion.

Distribution of Met-enkephalyl-Arg-Gly-Leu in rat larynx: partial coexistence with vasoactive intestinal polypeptide, peptide histidine isoleucine and neuropeptide Y

Using light microscopic (LM) enzyme-immunohistochemistry on deparaffinized adjacent sections Met-enkephalyl-Arg-Gly-Leu (ME-RGL) immunoreactivity was found to partially coexist with immunoreactive neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP) and peptide histidine isoleucine (PHI) in intrinsic laryngeal neurons of the rat. Further ME-RGL-immunoreactive (ir) fibres were found around glands in the subepithelium, in connective tissue of striated muscle and in the perichondrium, as well as around arterial and venous blood vessels. They frequently contacted mast cells and macrophages. The presence of ME-RGL indicates pro-enkephalin-related origin of this novel laryngeal opioid system. From the specific target relations and close interrelations of fibres staining for opioids with those staining for the other peptides--which are known to be more or less characteristic of the sympathetic (NPY), parasympathetic (VIP, PHI) and sensory (calcitonin gene-related peptide; CGRP) subdivisions of the peripheral nervous system--we deduce that opioid/non-opioid interactions might co-control various laryngeal functions, e.g. glandular secretion, blood flow, immune and inflammatory responses and/or might be of relevance in trophic mechanisms.

Synthesis and structure-activity relationships of N,N'-di-o-tolylguanidine analogues, high-affinity ligands for the haloperidol-sensitive sigma receptor

With an eye toward the development of novel atypical antipsychotic agents, we have studied the structure-affinity relationships of N,N'-di-o-tolylguanidine (DTG, 3) and its congeners at the haloperidol-sensitive sigma receptor. A number of DTG analogues were synthesized and evaluated in in vitro radioligand displacement experiments with guinea pig brain membrane homogenates, using the highly sigma-specific radioligands [3H]-3 and [3H]-(+)-3-(3-hydroxyphenyl)-N-(1-propyl)piperidine and the phencyclidine (PCP) receptor specific compounds [3H]-N-[1-(2-thienyl)-cyclohexyl]piperidine and [3H]-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10- imine. The affinity of N,N'-diarylguanidines for the sigma receptor decreases with increasing steric bulk of ortho substituents larger than C2H5. Hydrophobic substituents are generally preferred over similarly positioned hydrophilic ones. Furthermore, electroneutral substituents are preferred over strongly electron donating or withdrawing groups. Significant binding to the sigma receptor is usually retained as long as at least one side of the guanidine bears a preferred group (e.g. 2-CH3C6H5). Replacement of one or both aryl rings with certain saturated carbocycles (e.g. cyclohexyl, norbornyl, or adamantyl) leads to a significant increase in affinity. By combining the best aromatic and best saturated carbocyclic substituents in the same molecule, we arrived at some of the most potent sigma ligands described to date (e.g. N-exo-2-norbornyl-N'-(2-iodophenyl)guanidine, IC50 = 3 nM vs [3H]-3). All of the compounds tested were several orders of magnitude more potent at the sigma receptor than at the PCP receptor, with a few notable exceptions. This series of disubstituted guanidines may be of value in the development of potential antipsychotics and in the further pharmacological and biochemical characterization of the sigma receptor.

Histological framework of lymphatic vasa vasorum of major arteries: an experimental study

We investigated the histological framework of lymphatic vasa vasorum of major arteries in the rabbit and guinea pig combining the "natural filling method" with light and transmission electron microscopy. An absorbing adventitial lymphatic network consisting of large and sparsely distributed vessels with capillary structure occupied a more external arterial wall position than blood capillaries. The latter were smaller, more numerous, densely distributed, and located closer to the arterial lumen at the media-adventitial border. Periarterial lymphatics (with the structure of absorbing lymph vessels) encircled the wall of the major arteries and formed a rich and irregular plexus. The topography and anatomic structure of these absorbing lymph vessels suggest that lymphatic drainage plays a significant role in large arterial wall homeostasis.

[Does your patient take his medicine? Compliance problems in clinical practice]

There is convincing evidence from compliance research that deviations from the prescribed drug regimen is the rule rather than the exception. Demographic and psychosocial patient factors poorly correlate with non-compliance, whereas features of the disease, mechanisms of treatments, regimens and the patient physician interaction are particularly important determinants of patients' compliance behaviour. Non-compliance can not be predicted. There are problems in the assessment of non-compliance, more particularly of its clinical consequences. New microprocessor-based technology evaluated essential insight into patients' compliance behaviour and revealed different patterns of non-compliance. On one hand, the therapeutic outcome can be impaired by non-compliance, on the other hand, however, certain patterns of non-compliance appear to be appropriated from the patients' point of view. In medical practice it is important to consider non-compliance as essential impact on drug therapy and to promote the discussion of this issue with patients.

Variation of benzbromarone elimination in man--a population study

The plasma benzbromarone concentration-time profile in a healthy subject who retained the compound much longer than other individuals is described. The data suggested that determination of the 24 h plasma concentration of the parent drug after a single oral dose of 100 mg benzbromarone would be an appropriate procedure to determine the elimination phenotype. Based on this procedure, 148 of 153 healthy individuals (97%) in a population study were found to eliminate benzbromarone rapidly. In one subject the 24 h benzbromarone plasma concentration was very similar to that observed in the individual who had been more fully characterized. Four participants gave intermediate results. The data are compatible with a bimodal or trimodal distribution of different benzbromarone elimination phenotypes.

Internalization of endothelin by cultured human vascular smooth muscle cells: characterization and physiological significance

The binding and internalization of 125I-endothelin (125I-ET-1) was studied in cultured human vascular smooth muscle cells (hVSMC). Discrimination between surface-bound and internalized radiolabeled ligand was achieved using either acetic acid or trypsin treatment of cell layers, with the two procedures yielding comparable results. Total cellular 125I-ET-1 binding hVSMC at 37 degrees was rapid and reached near equilibrium within 30 min. Such binding could be resolved into surface-bound (acid/trypsin-sensitive) and internalized (acid/trypsin-resistant) components. The accumulation of internalized 125I-ET-1 was temperature dependent and occurred at 37 degrees (t1/2 approximately 15 min) but not at 4 degrees. Internalization of 125I-ET-1 by hVSMC was reversibly inhibited by the transglutaminase inhibitor dansylcadaverine (half-maximal inhibitory concentration, approximately 400 microM). Cytosolic acidification of hVSMC (from pH approximately 6.8 to approximately 6.3) by incubation with potassium acetate in a choline buffer also inhibited 125I-ET-1 internalization. Our observation indicate that smooth muscle cells internalize ET-1 via the clathrin-mediated endocytotic pathway. Dansylcadaverine and other inhibitors of transglutaminase inhibited ET-1-stimulated inositol phospholipid hydrolysis in hVSMC and decreased ET-1-induced vasoconstriction in isolated endothelium-denuded blood vessels. Internalization of ET-1 may, therefore, be relevant to the characteristically protracted physiological effects of this peptide on the vasculature.

Pharmacokinetics of technetium-99m-MAG3 in humans

Technetium-99m-mercaptoacetylglycylglycylglycine (99mTc-MAG3) is introduced to replace o-iodohippurate (OIH) for renal function studies. For interpretation of clinical findings, extensive pharmacokinetic studies were performed on patients. These showed that 99mTc-MAG3, compared with OIH, has a higher plasma-protein binding, an essentially higher intravascular concentration, a smaller volume of distribution and, with practically identical biologic half-lives, a correspondingly lower clearance. Simultaneous steady-state measurements resulted in a 1.5-fold higher clearance of OIH than of 99mTc-MAG3 (n = 124). Competitive inhibition of the tubular transport system by p-aminohippurate (PAH) (20 patients) revealed a distinctly higher suppression of the 99mTc-MAG3 clearance than of OIH which indicates a lower affinity of the 99mTc complex to the tubular cell. The plasma extraction efficiencies of both agents, measured during surgery (n = 5), did not indicate an extrarenal elimination of 99mTc-MAG3. This new radiopharmaceutical is a pragmatic alternative to OIH and offers advantages not only for scintigraphic imaging but is also suited for quantitative renal function studies.

[Practical approach according to the Federal Infection Legislation in meningococcal diseases in community facilities from the viewpoint of Public Health physicians in Offenburg]

Within the area for which the Public Health Office Offenburg is in charge, numerous meningococcal diseases in childhood occurred in 1988. As a result there of, a new strategy for the control of meningococcal diseases in day-care centers has been developed. In this respect priority has been given to rapid mutual information among the persons involved together with the strict control and supervision of all contact persons. This strategy led to an acceptable compromise for all persons involved; the strategy aims at achieving scientific accuracy and legal correctness, it is transparent and reproducible, and is easily implemented from an organisational point of view.

Effects of corn oil addition to the diet on the energy metabolism of heart, liver and kidney of female rats

Female rats (SIV-50, Sprague Dawley) given a diet enriched with corn oil (10% and 25% addition to rat chow, w/w) for four weeks showed changes in the energy metabolism of heart, liver and kidneys, that is, changes in oxygen consumption and uncoupling of oxidative phosphorylation of heart, liver and kidney mitochondria, concomitant to a decrease in heart mitochondrial creatine kinase activity and an increase in heart mitochondrial creatine content. The high fat diet also affected calcium binding and Na/K-, Mg- and Ca-ATPases of a cardiac myocyte membrane fraction. Lipid feeding also led to increase (biphasic and transient) of phospholipids, triglycerides and free fatty acids in the three organs studied, but in no case to hypertrophy.

Dynamics of drug regimen compliance--its assessment by microprocessor-based monitoring

The utility of a new microprocessor-based method for continuous monitoring of compliance in taking solid medicaments has been evaluated. Medication intake in 31 ambulant patients was assessed in a prospective observational study under the conditions of routine practice. The patients (aged 14-87 y, mean 50 y) were receiving long-term drug treatment for various chronic diseases. There was marked interindividual and intraindividual variation in compliance with different drugs. Deviations from the prescribed dosage regimens were caused by omission of doses (22.7% of prescribed doses) and intake of extra doses (5.6% of prescribed doses). Continuous monitoring revealed that in 19% of the monitoring period no medication was taken, in 13% there was partial intake, and in 8% extra doses were taken. Patient-initiated drug holidays occurred in 50% of patients. They were responsible for 76% of the medication-free time. It is concluded, that continuous compliance monitoring is practicable in ambulatory patients. It provides information about the dynamics of drug intake behaviour that cannot be obtained from medical histories or from clinical or laboratory examination. The information could be used effectively in individual patient care and in clinical drug trials.

Inducible endothelin mRNA expression and peptide secretion in cultured human vascular smooth muscle cells

This study demonstrates the induction of endothelin (ET) mRNA expression and synthesis of functional ET peptide in cultured human vascular smooth muscle cells (hVSMC). Compounds eliciting such responses in hVSMC include the vasoconstrictor hormones angiotensin II and arginine-vasopressin and the growth factors transforming growth factor beta, platelet derived growth factor AA and epidermal growth factor. Induction of ET mRNA expression in hVSMC exhibited transient kinetics (peak at 3-5 hrs. and return to basal within 7 hrs.) which differed from the more sustained ET transcript induction observed for porcine endothelial cells. ET peptide (determined by both radioimmuno- and radioreceptor assays) produced by stimulated hVSMC attained levels (approximately 120-160 pg/10(6) cells/4 hrs.; concentration approximately 3 x 10(-11) M) within the biologically effective concentration range of ET. Stimulated secretion of ET from hVSMC was abolished in the presence of the protein synthesis inhibitor cycloheximide. Sep-pak C18 extracts of medium from stimulated hVSMC elicited a concentration-dependent phosphoinositide catabolic response in myo-[2-3H]-inositol-prelabelled hVSMC. Our findings invoke a role for ET which extends beyond the paracrine regulation by peptide synthesized and secreted by endothelial cells. We propose that VSMC-synthesized ET may function in an autocrine manner to regulate both tone and structural modelling of vasculature.

A novel photoaffinity ligand for the phencyclidine site of the N-methyl-D-aspartate receptor labels a Mr 120,000 polypeptide

A radiolabeled photoaffinity ligand has been developed for the N-methyl-D-aspartate (NMDA)-preferring excitatory amino acid receptor complex. [3H]3-Azido-(5S, 10R)(+)-5-methyl-10,11-dihydro-5H- dibenzo[a,d]cyclohepten-5,10-imine [3H]3-azido-MK-801 demonstrated nearly identical affinity, density of binding sites, selectivity, pH sensitivity, and pharmacological profile in reversible binding assays with guinea pig brain homogenates to those displayed by its parent compound, MK-801. When employed in a photo-labeling protocol designed to optimize specific incorporation, [3H]3-azido-MK-801 labeled a single protein band which migrated in sodium dodecyl sulfate-polyacrylamide gels with Mr = 120,000. Incorporation of tritium into this band was completely inhibited when homogenates and [3H]3-azido-MK-801 were coincubated with 10 microM phencyclidine. These data suggest that the phencyclidine site of the NMDA receptor complex is at least in part comprised of a Mr = 120,000 polypeptide.

(+)-[3H]MK-801 binding sites in postmortem human brain

The pharmacological specificity and the regional distribution of the N-methyl-D-aspartate receptor-associated 5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate (MK-801) binding sites in human postmortem brain tissue were determined by binding studies using (+)-[3H]MK-801. Scatchard analysis revealed a high-affinity (KD = 0.9 +/- 0.2 nM, Bmax = 499 +/- 33 fmol/mg of protein) and a low-affinity (KD = 3.6 +/- 0.9 nM, Bmax = 194 +/- 44 fmol/mg of protein) binding site. The high-affinity site showed a different regional distribution of receptor density (cortex greater than hippocampus greater than striatum) compared to the low-affinity binding site (cerebellum greater than brainstem). The rank order pharmacological specificity and stereoselectivity of the high-(cortex) and low-(cerebellar) affinity binding sites were identical. However, all compounds tested showed greater potency at the high-affinity site in cortex. The results indicate that (+)-[3H]MK-801 binding in human postmortem brain tissue shows pharmacological and regional specificity.

The purine-cytosine permease gene of Saccharomyces cerevisiae: primary structure and deduced protein sequence of the FCY2 gene product

A 2.1 kb DNA segment carrying the purine-cytosine permease gene (FCY2) of Saccharomyces cerevisiae was sequenced, the primary structure of the protein (533 amino acids) deduced and a folding pattern in the membrane is proposed for the permease protein. Expression of the FCY2 gene product requires a functional secretory pathway and is reduced in mnn9, a mutant strain deficient in outer chain glycosylation. The FCY2 gene was mapped on the right arm of chromosome V close to the HIS1 gene.

Trisomy 4: a specific karyotype anomaly in primary and secondary acute myeloid leukemia

Trisomy 4 as single karyotype anomaly has recently been proposed as an acute myeloid leukemia (AML) specific aberration. Up to now, 20 cases have been reported in which the single abnormality occurred without additional chromosomal aberrations. Trisomy 4 has been found in both primary and secondary AML, the majority of cases being diagnosed as FAB M4 or M2 subtypes. In the cytogenetic analysis of 305 patients with AML, we found 209 cases with aberrant karyotypes, among them two patients (22a, male, M2; and 69a, male, M4) with trisomy 4 as single aberration. The younger patient achieved complete remission lasting 13 months and survived 22 months whereas the older patient died in aplastic phase due to septicaemia 5 weeks after admission. Trisomy 4 is proposed to be the primary aberration in both these cases of de novo AML. Although in one case, as in two cases reported earlier, cytogenetic results were only available in first relapse, we have no indication that trisomy 4 appeared in a secondary induced leukemia, because the leukemic blasts of the relapse were morphologically identical to first acute phase. In contrast to other specific chromosomal aberrations, results indicate that trisomy 4 has as yet no prognostic relevance concerning the clinical outcome.