Characterization of a variant of carcinoembryonic antigen (CEA) using monoclonal and polyclonal anti-CEA antibodies

A variant of the carcinoembryonic antigen (CEA) with lower molecular weight than a CEA reference preparation has been separated from CEA. Using a polyclonal, spleen absorbed anti-CEA antiserum, the variant crossreacts with reference CEA in immunodiffusion. The CEA-activity of the variant has been demonstrated using an enzyme-immunoassay with monoclonal CEA specific antibodies. There is sufficient immunological evidence that this variant is a distinct antigen different from the crossreactive antigens described so far. The reactivity of the polyclonal anti-CEA antiserum with the CEA variant was abolished by absorption against the immobilized variant.     

Light dependence of protoplasmic streaming in Nitella flexilis L. as measured by means of laser-velocimetry

Laser-velocimetry was applied in order to study the effect of light on the velocity of protoplasmic streaming (pps) in Characean cells. A change from dark to light (= 6 W · m^–2) leads to an acceleration of streaming by about 15–30% with a time-constant of approx. 300 s. The transition from light to dark causes a transient decrease of velocity below the original dark level. This response occurs with a time constant of about 500 s. It returns to its initial value with a time-constant of about 2000 s. This may indicate that a control loop of cytosolic homeostasis takes a decrease in pCa more seriously than an increase. A possible involvement of temperature effects caused by illumination was excluded by measuring the influence of temperature. Steady-state velocity of streaming changed by 5% per 1° C. Irradiation with infra-red light ( > 780 nm) did not cause a change in velocity. The absence of a light effect on streaming velocity in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) shows that photosynthesis and not phytochrome is involved. The role of light-induced changes of pCa is discussed, especially with respect to the hypothesis of Vanselow and Hansen (1989, J. Membr. Biol. 110, 175–187) that photosynthesis acts on the plasmalemma K⁺-channel via light-induced uptake of Ca²⁺ into the chloroplasts.Abbreviations and Symbols ASF auto structure function - DCMU 3-(3,4-dichlorophenyl)-1,1-dimethylurea - pps protoplasmic streaming - _L, _D, _C time-constants of the light and dark responses, and of a putative Ca-control system Financial support by the Deutsche Forschungsgemeinschaft is gratefully acknowledged. The first author was granted a scholarship by the state of Schleswig-Holstein. We are indebted to Prof. Dr. G. Pfister for technical advice and helpful discussions and to Mrs. E. Götting for drawing the figures.     

Biotechnological production of unnatural L-amino acids from D,L-5-monosubstituted hydantions. II. L-α- and L-β-naphthylalanine

Summary Resting cells ofArthrobacter sp. (DSM 3745) with the ability to form L-tryptophan from D,L-5-(3-indolylmethy)hydantoin were used for the bioconversion of D,L-5-- and D,L-5--naphthylmethylhydantoin (D,L-5-- and D,L-5--NMH) to the corresponding L-amino acids. Under the optimal reaction conditions of pH 9.7 and 40°C specific productivities of 0.2 (-naphtylalanine) and 0.6 (-naphtylalanine) mM amino acid x g cell dry mass^–1 x h^–1 were obtained in a 0.1 M Na₂CO₃/NaHCO₃-buffer in a strirred bioreactor.     

Determination of clozapine and its major metabolites in human serum using automated solid-phase extraction and subsequent isocratic high-performance liquid chromatography with ultraviolet detection

An isocratic high-performance liquid chromatographic (HPLC) method with ultraviolet detection is described for the quantification of the atypical neuroleptic clozapine and its major metabolites, N-desmethylclozapine and clozapine N-oxide, in human serum or plasma. The method included automated solid-phase extraction on C₁₈ reversed-phase material. Clozapine and its metabolites were separated by HPLC on a C₁₈ ODS Hypersil analytical column (5 μm particle size; 250 mm × 4.6 mm I.D.) using an acetonitrile—water (40:60, v/v) eluent buffered with 0.4% (v/v) N,N,N′,N′-tetramethylethylenediamine and acetic acid to pH 6.5. Imipramine served as internal standard. After extraction of 1 ml of serum or plasma, as little as 5 ng/ml of clozapine and 10 or 20 ng/ml of the metabolites were detectable. Linearity was found for drug concentrations between 5 and 2000 ng/ml as indicated by correlation coefficients of 0.998 to 0.985. The intra- and inter-assay coefficients of variation ranged between 1 and 20%. Interferences with other psychotropic drugs such as benzodiazepines, antidepressants or neuroleptics were negligible. In all samples, collected from schizophrenic patients who had been treated with daily oral doses of 75–400 mg of clozapine, the drug and its major metabolite, N-desmethylclozapine, could be detected, while the concentrations of clozapine N-oxide were below 20 ng/ml in three of sixteen patients. Using the method described here, data regarding relations between therapeutic or toxic effects and drug blood levels or metabolism may be collected in clinical practice to improve the therapeutic efficacy of clozapine drug treatment.     

Subcellular Distribution of 3α-Hydroxysteroid Dehydrogenase and Antiestrogen Action on Androgen-Metabolizing Enzymes in Rat Pituitary Gland

Abstract: Gonadectomy of male rats led to a threefold increase of 3α-hydroxysteroid dehydrogenase (3α-HSDH) activity in pituitary homogenates that could be completely reversed by chronic administration of estradiol or 5α-dihydrotestosterone (DHT). 3α-HSDH was found to be distributed mainly between the 10,000 g and 100,000 g sediments from whole homogenates. The microsomal enzyme activity showed a substantial specificity for NADH whereas the cytosolic enzyme (100,000 g supernatant) demonstrated a slight preference for NADPH. The changes in V _max found in homogenates following gonadectomy and gonadal steroid administration reflected changes in NADH- linked activity of the microsomal, but not the cytosolic enzyme. Estradiol-induced suppression of NADH-linked 3α-HSDH activity in pituitary homogenates from gonadectomized rats of either sex was accompanied by a similar suppression of NADPH-linked 5α-reductase activity and a marked decrease of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) release. In the ovariectomized rat chronic administration of nonsteroidal antiestrogens had strong estrogenic effects on 3α-HSDH activity and LH release, but not on 5α-reductase activity and FSH release. In the gonadectomized male rat, which was much less sensitive to intrinsic estrogenicity of the antiestrogens tested, nafoxidine completely blocked estradiol-induced suppression of 5α-reductase activity and FSH release and partially antagonized suppression of LH release. The trans -isomeric, substituted triphenylethylenes, tamoxifen, and enclomiphene, as well as nitromifene (mixture of trans and cis isomers) were able partially to counteract estradiol-induced suppression of 5α-reductase, but not 3α-HSDH activity. It is concluded that estradiol action on pituitary 5α-reductase, but not 3α-HSDH activity, involves an estrogen receptor mechanism.     

Immunohistochemical localization of secretory proteins in the endometrial epithelium of the rabbit

Summary Proteins of uterine fluid and lung homogenates of the rabbit were separated by gel and ion exchange chromatography. Purified protein fractions were used for immunisation and antiserum production. By means of several absorptions, six monospecific antisera against uteroglobin and five other proteins were obtained. Using immunohistochemistry, four of them could be localised in the uterine epithelium from oestrus and the first and the seventh day post coitum, and also in the blastocyst. The present study indicates the involvement of different endometrial cells in the synthesis and release of the various proteins of uterine secretion.Supported by grant Ki 154/6-7 from the Deutsche Forschungsgemeinschaft     

A toolbox for class I HDACs reveals isoform specific roles in gene regulation and protein acetylation

The class I histone deacetylases are essential regulators of cell fate decisions in health and disease. While pan- and class-specific HDAC inhibitors are available, these drugs do not allow a comprehensive understanding of individual HDAC function, or the therapeutic potential of isoform-specific targeting. To systematically compare the impact of individual catalytic functions of HDAC1, HDAC2 and HDAC3, we generated human HAP1 cell lines expressing catalytically inactive HDAC enzymes. Using this genetic toolbox we compare the effect of individual HDAC inhibition with the effects of class I specific inhibitors on cell viability, protein acetylation and gene expression. Individual inactivation of HDAC1 or HDAC2 has only mild effects on cell viability, while HDAC3 inactivation or loss results in DNA damage and apoptosis. Inactivation of HDAC1/HDAC2 led to increased acetylation of components of the COREST co-repressor complex, reduced deacetylase activity associated with this complex and derepression of neuronal genes. HDAC3 controls the acetylation of nuclear hormone receptor associated proteins and the expression of nuclear hormone receptor regulated genes. Acetylation of specific histone acetyltransferases and HDACs is sensitive to inactivation of HDAC1/HDAC2. Over a wide range of assays, we determined that in particular HDAC1 or HDAC2 catalytic inactivation mimics class I specific HDAC inhibitors. Importantly, we further demonstrate that catalytic inactivation of HDAC1 or HDAC2 sensitizes cells to specific cancer drugs. In summary, our systematic study revealed isoform-specific roles of HDAC1/2/3 catalytic functions. We suggest that targeted genetic inactivation of particular isoforms effectively mimics pharmacological HDAC inhibition allowing the identification of relevant HDACs as targets for therapeutic intervention.     

The clinical characterization of the adult patient with bipolar disorder aimed at personalization of management

Bipolar disorder is heterogeneous in phenomenology, illness trajectory, and response to treatment. Despite evidence for the efficacy of multimodal­ity interventions, the majority of persons affected by this disorder do not achieve and sustain full syndromal recovery. It is eagerly anticipated that combining datasets across various information sources (e.g., hierarchical “multi‐omic” measures, electronic health records), analyzed using advanced computational methods (e.g., machine learning), will inform future diagnosis and treatment selection. In the interim, identifying clinically meaningful subgroups of persons with the disorder having differential response to specific treatments at point‐of‐care is an empirical priority. This paper endeavours to synthesize salient domains in the clinical characterization of the adult patient with bipolar disorder, with the overarching aim to improve health outcomes by informing patient management and treatment considerations. Extant data indicate that characterizing select domains in bipolar disorder provides actionable information and guides shared decision making. For example, it is robustly established that the presence of mixed features – especially during depressive episodes – and of physical and psychiatric comorbidities informs illness trajectory, response to treatment, and suicide risk. In addition, early environmental exposures (e.g., sexual and physical abuse, emotional neglect) are highly associated with more complicated illness presentations, inviting the need for developmentally‐oriented and integrated treatment approaches. There have been significant advances in validating subtypes of bipolar disorder (e.g., bipolar I vs. II disorder), particularly in regard to pharmacological interventions. As with other severe mental disorders, social functioning, interpersonal/family relationships and internalized stigma are domains highly relevant to relapse risk, health outcomes, and quality of life. The elevated standardized mortality ratio for completed suicide and suicidal behaviour in bipolar disorder invites the need for characterization of this domain in all patients. The framework of this paper is to describe all the above salient domains, providing a synthesis of extant literature and recommendations for decision support tools and clinical metrics that can be implemented at point‐of‐care.