Repeat expansions in AR, ATXN1, ATXN2 and HTT in Norwegian patients diagnosed with amyotrophic lateral sclerosis

Genetic repeat expansions cause neuronal degeneration in amyotrophic lateral sclerosis as well as other neurodegenerative disorders such as spinocerebellar ataxia, Huntington's disease and Kennedy's disease. Repeat expansions in the same gene can cause multiple clinical phenotypes. We aimed to characterize repeat expansions in a Norwegian amyotrophic lateral sclerosis cohort. Norwegian amyotrophic lateral sclerosis patients (n = 414) and neurologically healthy controls adjusted for age and gender (n = 713) were investigated for repeat expansions in AR, ATXN1, ATXN2 and HTT using short read exome sequencing and the ExpansionHunter software. Five amyotrophic lateral sclerosis patients (1.2%) and two controls (0.3%) carried ≥36 repeats in HTT (P = 0.032), and seven amyotrophic lateral sclerosis patients (1.7%) and three controls (0.4%) carried ≥29 repeats in ATXN2 (P = 0.038). One male diagnosed with amyotrophic lateral sclerosis carried a pathogenic repeat expansion in AR, and his diagnosis was revised to Kennedy's disease. In ATXN1, 50 amyotrophic lateral sclerosis patients (12.1%) and 96 controls (13.5%) carried ≥33 repeats (P = 0.753). None of the patients with repeat expansions in ATXN2 or HTT had signs of Huntington's disease or spinocerebellar ataxia type 2, based on a re-evaluation of medical records. The diagnosis of amyotrophic lateral sclerosis was confirmed in all patients, with the exception of one patient who had primary lateral sclerosis. Our findings indicate that repeat expansions in HTT and ATXN2 are associated with increased likelihood of developing amyotrophic lateral sclerosis. Further studies are required to investigate the potential relationship between HTT repeat expansions and amyotrophic lateral sclerosis.

Genetic epidemiology of amyotrophic lateral sclerosis in Norway - a 2-year population based study

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that affects motor neurons. In Europe, disease-causing genetic variants have been identified in 40-70% of familial ALS patients and approximately in 5% of sporadic ALS patients. In Norway, the contribution of genetic variants to ALS has not yet been studied. In light of the potential development of personalized medicine, knowledge of genetic causes of ALS in a population is becoming increasingly important. The present study provides clinical and genetic data on familial and sporadic ALS patients in a Norwegian population-based cohort.

METHODS

Blood samples and clinical information from ALS patients were obtained at all 17 neurological departments throughout Norway during a 2-year period. Genetic analysis of the samples involved expansion analysis of C9orf72 and exome sequencing targeting 30 known ALS-linked genes. The variants were classified using genotype-phenotype correlations and bioinformatics tools.

RESULTS

A total of 279 ALS patients were included in the study. Of these, 11.5% had one or several family members affected with ALS, whereas 88.5% had no known family history of ALS. A genetic cause of ALS was identified in 31 individuals (11.1%), among which 18 (58.1%) were familial and 13 (41.9%) were sporadic. The most common genetic cause was the C9orf72 expansion (6.8%), which was identified in 8 familial and 11 sporadic ALS patients. Pathogenic or likely pathogenic variants of SOD1 and TBK1 were identified in 10 familial and 2 sporadic cases. C9orf72 expansions dominated in patients from the Northern and Central regions, whereas SOD1 variants dominated in patients from the South-Eastern region.

CONCLUSION

In the present study, we identified several pathogenic gene variants in both familial and sporadic ALS patients. Restricting genetic analysis to only familial cases would miss more than 40 percent of those with a disease-causing genetic variant, indicating the need for genetic analysis in sporadic cases as well.

Different endurance exercises modulate NK cell cytotoxic and inhibiting receptors

PURPOSE

Induction of IDO depends on the activation of AhR forming the AhR/IDO axis. Activated AhR can transcribe various target genes including cytotoxic and inhibiting receptors of NK cells. We investigated whether AhR and IDO levels as well as activating (NKG2D) and inhibiting (KIR2DL1) NK cell receptors are influenced by acute exercise and different chronic endurance exercise programs.

METHODS

21 adult breast and prostate cancer patients of the TOP study (NCT02883699) were randomized to intervention programs of 12 weeks of (1) endurance standard training or (2) endurance polarized training after a cardiopulmonary exercise test (CPET). Serum was collected pre-CPET, immediately post-CPET, 1 h post-CPET and after 12 weeks post-intervention. Flow cytometry analysis was performed on autologous serum incubated NK-92 cells for: AhR, IDO, KIR2DL1 and NKG2D. Differences were investigated using analysis-of-variance for acute and analysis-of-covariance for chronic effects.

RESULTS

Acute exercise: IDO levels changed over time with a significant increase from post-CPET to 1 h post-CPET (p = 0.03). KIR2DL1 levels significantly decreased over time (p < 0.01). NKG2D levels remained constant (p = 0.31). Chronic exercise: for both IDO and NKG2D a significant group × time interaction, a significant time effect and a significant difference after 12 weeks of intervention were observed (IDO: all p < 0.01, NKG2D: all p > 0.05).

CONCLUSION

Both acute and chronic endurance training may regulate NK cell function via the AhR/IDO axis. This is clinically relevant, as exercise emerges to be a key player in immune regulation.

Conformationally restrained aromatic analogues of fosmidomycin and FR900098

The synthesis and in-vitro antimalarial activity of conformationally restrained bis(pivaloyloxymethyl) ester analogues of the natural product fosmidomycin is presented. In contrast to alpha-aryl-substituted analogues, conformationally restrained aromatic analogues exhibit only moderate in-vitro antimalarial activity against the chloroquine-sensitive strain 3D7 of Plasmodium falciparum. The most active derivative displays an IC(50) value of 47 microM.

Arylmethyl substituted derivatives of Fosmidomycin: synthesis and antimalarial activity

The phosphonohydroxamic acid Fosmidomycin is a drug candidate for the treatment of Malaria, currently in phase II trials in combination with Clindamycin. In order to obtain compounds of higher lipophilicity, we recently synthesized alpha-phenyl substituted Fosmidomycin derivatives which display high antimalarial activity. We now report the synthesis and in vitro antimalarial activity of arylmethyl substituted bis(pivaloyloxymethyl) ester prodrugs of Fosmidomycin and its acetyl analogue FR900098. The 3,4-dichlorobenzyl substituted derivative of Fosmidomycin proved to be about twice as active as the respective Fosmidomycin prodrug, however, less active than the corresponding FR900098 prodrug. Electron donating substituents as well as voluminous substituents led to a significant reduction of activity.

Synthesis and antimalarial activity of chain substituted pivaloyloxymethyl ester analogues of Fosmidomycin and FR900098

Fosmidomycin is a promising antimalarial drug candidate with a unique chemical structure and a novel mode of action. Chain substituted pivaloyloxymethyl ester derivatives of Fosmidomycin and its acetyl analogue FR900098 have been synthesized and their in vitro antimalarial activity versus the Chloroquine sensitive strain 3D7 of Plasmodium falciparum has been determined.

Hypertrophy-associated gene induction after beta-adrenergic stimulation in adult cardiomyocytes

In isolated cardiomyocytes, hypertrophic responsiveness to beta-adrenergic stimulation can be induced by pre-exposure of the cells to TGF-beta. To characterize genes involved in beta-adrenergically mediated hypertrophy, mRNA expression patterns in isoprenaline-stimulated cardiomyocytes which were pre-exposed to TGF-beta were analysed by differential display RT-PCR analysis. Eighteen fragments, upregulated by isoprenaline, were identified. Six of them, which code for proteins with known function, were further analysed by RT-PCR (1) to verify their induction after beta-adrenergic stimulation, (2) to restrict their number to genes only upregulated after hypertrophy inducing beta-adrenergic stimulation, and (3) to study their expression in stroke-prone spontaneous hypertrophic rats (SHR-sp), an in vivo model of myocardial hypertrophy, in which elevated levels of TGF-beta are found. Induction by isoprenaline could be proved for all but one of the six genes. Further analysis of these genes in freshly isolated myocytes, which respond with hypertrophic growth only to alpha--but not beta--adrenergic stimulation, revealed that three of them, coding for the translation initiation factor sui 1, the cis-golgi transport protein p28 and the mitochondrial NADH-dehydrogenase II subunit, are specifically induced in TGF-beta-pre-exposed cardiomyocytes after beta-adrenergic stimulation. Their induction is therefore closely associated with a beta-adrenergic growth response in isolated cardiomyocytes. p28-mRNA is also markedly increased in SHR-sp rats. Antisense experiments revealed a functional importance of p28 for the beta-adrenergic growth response in isolated cardiomyocytes. Therefore, p28 seems causally involved in this beta-adrenergic growth response.

Functional characterization of green fluorescent protein-profilin fusion proteins

To clarify the role of profilins in cells, fusion proteins constructed with green fluorescent protein (GFP) should be extremely helpful. As profilins are considerably smaller than the GFP fusion partner (14-17 kDa compared with 27 kDa, respectively), we characterized the fusion proteins in vitro, to ascertain their biological function. We fused mouse profilin I and II to either the C-terminus or N-terminus of GFP. These fusion proteins were expressed in Escherichia coli and affinity-purified on polyproline-Sepharose. Interaction with vasodilator-stimulated phosphoprotein, a proline-rich ligand of profilin, was investigated by ELISA, as was binding to PtdIns(4,5)P2. The affinity for actin was quantitatively determined in polymerization assays. Our results show that fusion of GFP to the C-terminus of profilin I abolishes polyproline binding. In contrast, the other fusion proteins bound to polyproline-Sepharose and VASP. Binding to PtdIns(4,5)P2 was not significantly altered. Furthermore, fusion of either isoform with GFP did not decrease the affinity for actin. In localization studies with mammalian cells, all fusion proteins showed the localization expected for profilin in areas of high actin dynamics, such as leading lamellae and ruffles induced by epidermal growth factor. However, with regard to our in vitro data, we suspect that only a minor fraction of profilin I carrying the GFP at the C-terminus can target these sites. Therefore, other constructs should be preferred for further in vivo studies.

Differential colocalization of profilin with microfilaments in PtK2 cells

Profilins are thought to be involved in the control of actin dynamics in eukaryotic cells. In accordance with this concept, profilin was found to be colocalized with the cortical microfilament webs in leading lamellae of locomoting and spreading fibroblasts. However, so far, there is little information on the distribution of profilin in other cell types. In this study, we report on the colocalization of profilin with various microfilament suprastructures in the epithelial cell line PtK2. This cell line, which is derived from rat kangaroo, contains a profilin sharing an N-terminal epitope with bovine and human profilin I, as seen by immunoblotting with monoclonal antibodies. By using immunofluorescence in conjunction with conventional fluorescence microscopy and confocal laser-scanning microscopy, we found profilin in ruffling areas of the peripheral lamellae and nascent stress fibers of spreading cells, whereas the peripheral belts of stationary cells growing in epithelioid sheets lacked profilin staining. In these cells, profilin was primarily distributed in a fine reticular or vesicular network that was not related to the microfilament system. Conspicuously low levels of profilins was not related to the contractile ring of mitotic cells. This was found for different fixation protocols and antibodies of the IgG and IgM type, respectively, indicating that lack of staining of the cleavage furrow was not due to antibody penetration problems. Depending on the fixation protocol, the nuclear matrix appeared strongly positive or negative for profilin. Cells microinjected with birch pollen profilin and labeled with a birch profilin-specific monoclonal antibody corroborated the results obtained with the endogeneous protein: The injected profilin was targeted to the cortical web and to nascent stress fibers of spreading cells but not to the cleavage ring of mitotic cells. These results suggest that high concentrations of a profilin I homologue are preferentially located with those microfilament suprastructures in PtK2 cells that are subject to rapid modulation by external signals.

Expression, release, and biological activity of parathyroid hormone-related peptide from coronary endothelial cells

Ventricular cardiomyocytes have previously been identified as potential target cells for parathyroid hormone-related peptide (PTHrP). Synthetic PTHrP peptides exert a positive contractile effect. Because systemic PTHrP levels are normally negligible, this suggests that PTHrP is expressed in the ventricle and acts as a paracrine mediator. We investigated the ventricular expression of PTHrP and its expression in cultured cells isolated from the ventricle, studied the release of PTHrP from hearts and cultures, and investigated whether this authentic PTHrP mimics the biological effects previously described for synthetic PTHrP on ventricular cardiomyocytes. We found PTHrP expressed in ventricles of neonatal and adult rat hearts. In cells isolated from adult hearts, we found PTHrP expression exclusively in coronary endothelial cells but not in cardiomyocytes. The latter, however, are target cells for PTHrP. PTHrP was released from isolated perfused hearts during hypoxic perfusion and from cultured coronary endothelial cells under energy-depleting conditions. This PTHrP was biologically active; ie, it exerted a positive contractile and lusitropic effect on cardiomyocytes. Authentic PTHrP was glycosylated and showed a slightly higher potency than synthetic PTHrP. These results suggest that PTHrP is an endothelium-derived modulator of ventricular function.

Accumulation of profilin II at the surface of Listeria is concomitant with the onset of motility and correlates with bacterial speed

The spatial and temporal activity of the actin cytoskeleton is precisely regulated during cell motility by several microfilament-associated proteins of which profilin plays an essential role. We have analysed the distribution of green fluorescent protein (GFP)-tagged profilins in cultured and in Listeria-infected cells. Among the different GFP-profilin fusion proteins studied, only the construct in which the GFP moiety was fused to the carboxy terminus of profilin II (profilin II-GFP) was recruited by intracellular Listeria. The in vitro ligand-binding properties of this construct, e.g. the binding to monomeric actin, poly-L-proline and phosphatidylinositol 4,5-bisphosphate (PIP2), were unaffected by GFP. Profilin II-GFP co-localised with vinculin and Mena to the focal adhesions in REF-52 fibroblasts and was distributed as a thin line at the front of protruding lamellipodia in B16-F1 mouse melanoma cells. In Listeria-infected cells, profilin II-GFP was recruited, in an asymmetric fashion, to the surface of Listeria at the onset of motility whereas it was not detectable on non-motile bacteria. In contrast to the vasodilator-stimulated phosphoprotein (VASP), profilin II-GFP localised at the bacterial surface only on motile Listeria. Moreover, the fluorescence intensity of profilin II-GFP directly correlated with the speed of the bacteria. Thus, the use of GFP-tagged profilin II provides new insights into the role of profilins in cellular motility.

[Work and vocational integration of psychosomatic patients--utilization and indications for a workload tryout program]

The effect of a professional workload test was assessed in a longitudinal study with 80 patients psychosomatic rehabilitation during and following their. In a second study indication criteria were tested with 358 consecutive patients. Participants in the workload program show an improvement of their work ability and job performance according to self-appraisal, superior appraisal and medical assessment. Work ability was still maintained 7 months after treatment. Patients with lasting work disability and unemployment not only show negative work-related attitudes, but also elevated psychological symptoms and a reduced quality of life. The program participants show high levels of psychological strain but also a stronger disposition to change the professional situation. Negative work-related and psychological consequences of lasting disability and unemployment deserve more attention in inpatient psychosomatic treatment.

Effects of single amino acid substitutions in the actin-binding site on the biological activity of bovine profilin I

For a detailed analysis of the profilin-actin interaction, we designed several point mutations in bovine profilin I by computer modeling. The recombinant proteins were analyzed in vitro for their actin-binding properties. Mutant proteins with a putatively higher affinity for actin were produced by attempting to introduce an additional bond to actin. However, these mutants displayed a lower affinity for actin than wild-type profilin, suggesting that additional putative bonds created this way cannot increase profilin's affinity for actin. In contrast, mutants designed to have a reduced affinity for actin by eliminating profilin-actin bonds displayed the desired properties in viscosity assays, while their binding sites for poly(L)proline were still intact. The profilin mutant F59A, with an affinity for actin reduced by one order of magnitude as compared to wild-type profilin, was analyzed further in cells. When microinjected into fibroblasts, F59A colocalized with the endogenous profilin and actin in ruffling areas, suggesting that profilins are targeted to and tethered at these sites by ligands other than actin. Profilin null cells of Dictyostelium were transfected with bovine wild-type profilin I and F59A. Bovine profilin I, although expressed to only approximately 10% of the endogenous profilin level determined for wild-type Dictyostelium, caused a substantial rescue of the defects observed in profilin null amoebae, as seen by measuring the growth of colony surface areas and the percentage of polynucleated cells. The mutant protein was much less effective. These results emphasize the highly conserved biological function of profilins with low sequence homology, and correlate specifically their actin-binding capacity with cell motility and proliferation.

Activation of p70(S6) kinase by beta-adrenoceptor agonists on adult cardiomyocytes

Cardiac cellular hypertrophy plays an important role in cardiovascular diseases. Up until now, little has been known about the regulation of cellular growth on the level of intracellular signalling. Here, the implication of the p70(S6)-kinase (p70(S6K)) in the hypertrophic response after beta-adrenergic stimulation of cardiac myocytes from adult rats was investigated. Isoproterenol stimulation can activate p70(S6K) in adult cardiomyocytes analysed by direct kinase assays and retarded gel mobility. This signalling of beta-adrenoceptor stimulation is found only under conditions where the cardiomyocytes exhibit also a hypertrophic response to beta-adrenoceptor stimulation as measured by increase in protein content, RNA content and incorporation of radiolabelled amino acids. Rapamycin, a specific inhibitor of this kinase, reduces the trophic responses to control levels, suggesting an involvement of the p70(S6)-kinase in the development of cellular hypertrophy. An engagement of the MAP-kinase (ERK-1/2) pathway in the beta-adrenergic induced growth of cardiac myocytes from adult rats was excluded.

An alpha-actinin-profilin chimaera with two alternatively operating actin-binding sites

Studying the mode of interaction between actin and actin-binding proteins, we constructed a chimaeric protein consisting of the sequence for bovine profilin I (P), to which the sequence for the actin-binding domain of Dictyostelium discoideum alpha-actinin (alphaA1-2) was fused N-terminally. The resulting hybrid clone was expressed in Escherichia coli, and the chimaeric protein, alphaA1-2P, purified by affinity chromatography on poly-(L-proline) (PLP) columns and identified using specific antibodies. High resolution electron microscopy demonstrated that this protein consists of two discrete subdomains. In biochemical, viscometric and electron microscopic analyses, we showed that both modules in this molecule are biologically active. The chimaera binds to poly-(L-proline) and inhibits the polymerization of G-actin in KCl, which is consistent with the assumption that the profilin part is intact. Inhibition of actin polymerization in KCl was stronger than that of the parental profilin, and the Kd value of its interaction with rabbit skeletal muscle actin, as determined by falling ball viscometry, was smaller (mean value 0.5 x 10(-6) M, as compared to 1.9 x 10(-6) M for bovine profilin). In 2mM MgCl2, the actin polymerized rapidly, consistent with the interpretation that under these conditions the chimaera, like profilin, is less efficient as an actin-sequestering agent. In the presence of alphaA1-2P, the resulting filaments were decorated with particles projecting from the filament axis. We conclude that under these conditions the alphaA1-2 domain of alphaA1-2P is preferentially active, attaching the chimaeric particles laterally to the filaments. Hence, the parental modules combined in alphaA1-2P permit this molecule to switch from a G-actin- to an F-actin-binding form.

Birch pollen profilin: structural organization and interaction with poly-(L-proline) peptides as revealed by NMR

The secondary structure of birch pollen profilin, a potent human allergen, was elucidated by multidimensional nuclear magnetic resonance (NMR), as a prerequisite to study the interaction of this profilin with ligands for its poly-(L-proline) (PLP)-binding site. The chemical shifts of the 15N-labeled backbone amide groups were used to monitor complex formation with various PLP peptides. Titration with deca-L-proline (P10) yielded a KD of 0.2 mM. P8 was the shortest PLP to provoke a significant reaction. (GP5)3G bound significantly, confirming the interaction between profilins and the protein VASP containing this motif. Birch profilin interacted also with GP6GP5, found in the cyclase-associated protein (CAP), a suspected profilin ligand.

The molecular architecture of focal adhesions

This article outlines the present knowledge of the architecture, molecular composition, and dynamics of focal contacts of adhesive animal cells. These structures, developed at the plasma membrane at sites where cells touch their substratum, are essential for cellular attachment in tissue formation during embryogenesis and wound healing. In tissue culture, they are particularly prominent and thus amenable to detailed investigation. Focal contacts consist of a cytoplasmic face, comprising cytoskeletal elements, a transmembrane connecting region, and a extracellular face composed of proteins of the extracellular matrix. The molecular anatomy of the numerous proteins involved, the basis for classifying them as structural or regulatory components, and their in vitro interactions are described. Based on this information, current models on the dynamics of their assembly and of possible regulatory mechanisms involving a variety of signal transduction pathways are discussed.

"Horizontal" gene transfer from a transgenic potato line to a bacterial pathogen (Erwinia chrysanthemi) occurs--if at all--at an extremely low frequency

The frequency of possible "horizontal" gene transfer between a plant and a tightly associated bacterial pathogen was studied in a model system consisting of transgenic Solanum tuberosum, containing a beta-lactamase gene linked to a pBR322 origin of replication, and Erwinia chrysanthemi. This experimental system offers optimal conditions for the detection of possible horizontal gene transfer events, even when they occur at very low frequency. Horizontal gene transfer was not detected under conditions mimicking a "natural" infection. The gradual, stepwise alteration of artificial, positive control conditions to idealized natural conditions, however, allowed the characterization of factors that affected gene transfer, and revealed a gradual decrease of the gene transfer frequency from 6.3 x 10(-2) under optimal control conditions to a calculated 2.0 x 10(-17) under idealized natural conditions. These data, in combination with other published studies, argue that horizontal gene transfer is so rare as to be essentially irrelevant to any realistic assessment of the risk involved in release experiments involving transgenic plants.

Improved detection of hepatitis C virus RNA by reverse transcription and polymerase chain reaction

The polymerase chain reaction with prior reverse transcription of RNA into cDNA was applied to hepatitis C virus RNA detection in human serum samples of different origin. In order to eliminate false negative results, the following steps were optimized: RNA extraction, reverse transcription, and oligonucleotide primer selection. We compared different RNA extraction methods using guanidinium salt/detergent and proteinase K digestion/phenol extraction, and tested virus particle enrichment with polyethylene glycol precipitation and ultracentrifugation. RNA extraction with guanidinium salt/detergent was the most efficient method. Ultracentrifugation of single samples did not improve hepatitis C virus RNA detection. Polyethylene glycol precipitation performed poorly. Recombinant thermostable reverse transcriptase produced cDNA from fewer samples than did Moloney murine leukaemia virus reverse transcriptase. Nested oligonucleotide primers from the 5'-terminal non-coding region of the hepatitis C virus genome amplified cDNA from more samples than did primers from the coding regions. Thirty six anti-hepatitis C virus antibody positive samples were tested; nested primers (nucleotides 6 to 327 and 15 to 288) yielded 21 amplificates, whereas primers from the coding region produced 16 amplificates (nucleotides 4684-5276) and 5 amplificates (nucleotides 5166-5270), respectively. The most efficient combination of steps was RNA extraction with guanidinium salt solution, reverse transcription with Moloney murine leukaemia virus reverse transcriptase and nested polymerase chain reaction primed with primers from the 5'-terminal non-coding region of the hepatitis C virus genome. Other combinations produced more false negative results. Three different groups of anti-hepatitis C virus antibody positive individuals had markedly different viraemia patterns: Hepatitis C virus RNA was detected in the sera of only 10% of anti-hepatitis C virus antibody positive blood donors, but in 90% of anti-hepatitis C virus antibody positive patients with clinically manifest hepatitis C, and 90% of anti-hepatitis C virus antibody positive haemophiliacs who had received plasma products in the past which had not been virus-inactivated. No hepatitis C virus RNA could be detected in the sera of 450 anti-hepatitis C virus antibody negative blood donors with elevated serum alanine aminotransferase catalytic concentrations.

Immunoglobulin preparations from hepatitis C antibody-positive plasma donors: influence on diagnosis and risk of infection in heart transplant recipients

All heart transplant patients in our clinic received intravenous immunoglobulins as a prophylaxis against cytomegalovirus infections or reactivations. Serum was sampled from 160 heart transplant patients within 4 months after surgery. In 98 samples (61%) hepatitis C virus (HCV)-specific antibodies could be detected by a "second generation" enzyme immunoassay. Of these HCV antibody-positive patients 89 were tested for a second time. At this time, 5-11 months later, in 66 patients (74%) the HCV antibody had disappeared. In the 23 still positively reacting patients, immunoglobulins were given in the last 6 months before serum sampling. Nine commercial immunoglobulin preparations were tested for HCV-specific antibodies and the presence of HCV RNA. Seven preparations were anti-HCV positive with titres in the range of 64-256, whereas reverse transcription and polymerase chain reaction did not detect HCV RNA in any immunoglobulin preparation. Passive antibody transfer rather than a HCV infection is the cause of HCV antibody detection in our patients. The presence of HCV antibodies in high concentrations in commercial immunoglobulin preparations may only be explained by an extremely high proportion of anti-HCV-positive single donations in the plasma pools used for immunoglobulin production. The passive HCV antibody transmission prevents anti-HCV serological monitoring of patients treated with these preparations. Additionally, there are reports on the transmission of hepatitis non-A, non-B via immunoglobulin preparations. Therefore, we recommend an anti-HCV screening of plasma donors.

Pharmacokinetics of a long-acting bromocriptine preparation (Parlodel LA) and its effect on release of prolactin and growth hormone

The pharmacokinetics and endocrine actions of a long-acting form of bromocriptine (Parlodel) were examined in a controlled study in 10 healthy volunteers receiving a single i.m. injection of 50 mg. Six further subjects took bromocriptine 1.25 mg t.i.d. for 3 days p.o. In the subjects given the slow release preparation, the plasma bromocriptine concentrations increased sharply to a maximum of 1.65 mg/l 2 h after injection. This fast release process was followed by slow clearance with a half-life of 16 days. The substance was still detectable in plasma 35 days postinjection. Plasma prolactin (PRL) fell rapidly from a mean of 5.6 ng/ml to reach significantly lower levels at 60 and 120 min. Inhibition was maintained for up to 35 days, when plasma PRL was still significantly below the values recorded at baseline and in the control group. Plasma GH peaked at 3.6 ng/ml at 120 min and subsequently declined slowly to stabilize between 1.4 and 2.2 ng/ml for about 12 h, falling to below the 1 ng/ml limit for the remainder of the study period. In contrast, individuals receiving oral bromocriptine exhibited a significant elevation following the first dose and an equivalent increment after the morning dose on Day 3. Thus, the results show a prolonged inhibitory effect on PRL of this long-acting bromocriptine preparation in parallel with its slow plasma clearance. The stimulant effect on GH secretion is short lived, presumably due to desensitisation of specific receptors.

Co-clustering of denatured hemoglobin with band 3: its role in binding of autoantibodies against band 3 to abnormal and aged erythrocytes

Precipitates of hemoglobin, termed Heinz bodies, occur in a fraction of erythrocytes after removal of the spleen and are also observed in aged erythrocytes. This implies that precipitates of hemoglobin might play a particular role in senescent cell recognition. By using immunofluorescence microscopy, evidence is presented in splenectomized patients and in several patients with unstable (mutant) hemoglobins that membrane-attached Heinz bodies are associated with both clusters of the anion channel, band 3, and clusters of surface-bound immunoglobulins (IgG). In 75% of the cases of unstable hemoglobin, such as sickle cell anemia or hemoglobin Köln disease, the level of cell-bound IgG (measured by 125I-labeled staphylococcal protein A) was increased severalfold above the level found in healthy controls. Immunoblot analysis identified the major fraction of cell-bound IgG to be directed to band 3. These observations indicate copolymerization of denatured hemoglobin with the cytoplasmic domain of band 3, which may cause band 3 to form clusters. These clusters probably serve as thermodynamically favored binding sites for autoantibodies in serum, which promote elimination of the erythrocytes by the immune system. Thus, erythrocytes may be removed from circulation when hemoglobin begins to denature and the cells begin to fail in their main function of oxygen transport.

Endocrine profile of a long-acting somatostatin derivative SMS 201-995. Study in normal volunteers following subcutaneous administration

The pharmacokinetics and the endocrine profile of a new low molecular somatostatin derivative, SMS 201-995, were investigated in a group of 35 normal subjects. Clearance studies (n = 6) for this peptide showed a prolonged half-life in plasma, 113 min, following single sc injections of 50 or 100 micrograms. Arginine stimulation tests (n = 6) were conducted immediately and 180 min after sc injection of 50 micrograms of SMS 201-995. The stimulatory effect of arginine on GH and insulin was counteracted by the peptide at the P less than 0.001 and P less than 0.02 significance level, respectively. Delayed arginine stimulation revealed a persistent blockade of the GH release (P less than 0.02), whereas a recovery of the insulin response was observed. Plasma glucagon increments following a standard protein meal (n = 10) were significantly (P less than 0.001) inhibited by previous sc injection of 50 micrograms of SMS 202-995. Pretreatment with 50 and 100 micrograms of SMS 202-995 sc (n = 9) inhibited (P less than 0.001) the stimulatory effect of TRH (200 micrograms iv) on TSH without modifying basal levels. The injection of 100 micrograms/h during sleep completely abolished the nocturnal GH peak in 4 volunteers. No rebound rise after decline of the suppressive action on GH was recorded in any of the trials. Safety chemistries and blood coagulation studies remained normal and no side-effects or untoward reactions were recorded throughout the investigation.(ABSTRACT TRUNCATED AT 250 WORDS)

Colocalization of band 3 with ankyrin and spectrin at the basal membrane of intercalated cells in the rat kidney

An immunoreactive form of the anion channel protein of erythrocytes, band 3, has been identified in the rat kidney. It is found in the intercalated cells of the distal tubule and collecting ducts. Immunostaining specific for band 3 is confined to the basolateral plasma membrane of these cells, where this protein probably mediates the transport of bicarbonate across the tubular wall. Double-immunolabeling studies demonstrate that band 3 is colocalized with immunoreactive forms of ankyrin and spectrin along the basolateral plasma membrane. The polarized distribution of band 3 may be the result of the association of its cytoplasmic domain with ankyrin, which in turn links band 3 to spectrin and the cytoskeleton. These observations help to explain how the collecting ducts of the kidney can direct the transport of bicarbonate ions, thus maintaining the acid-base balance.

Binding of biosynthetic human insulin to human antibodies and receptors

The binding of biosynthetic human insulin (BHI) and pork insulin to anti-pork insulin antibodies was tested at an insulin concentration of 4 microunits/ml. Identical binding data were obtained. The binding of the two insulins to mononuclear lymphocytes was also identical. The data are compared to previous results obtained with synthetic human insulin. Previously, we investigated the in vitro properties of fully synthetic human insulin from Dr. Rittel, Ciba-Geigy, Basel. Receptor binding of this human insulin was identical to pork insulin. The binding properties of the new BHI from Lilly (Indianapolis) were studied with human antibodies and freshly isolated human monocytes.

Development of subcutaneous fat in infancy. Standards for tricipital, subscapular, and suprailiacal skinfolds in german infants

In order to assess the nutritional status of healthy infants in Berlin, the tricipital (TRI), subscapular (SCA), and suprailiacal (SIL) skinfolds were measured at several instances (2--14 times) during regular presentations at the well baby clinic offices in 265 infants of normal gestation, 140 boys and 125 girls, using the Holtain skinfold caliper. The characteristic pattern of skinfold development in infancy includes a rapid increase in width of all diameters until 3--5 months of age, and a gradual decrease thereafter. This diminution of skinfold thickness is more pronounced at the trunk (SIL and SCA) than at the limbs (TRI), indicating a change in distribution of subcutaneous tissue during infancy. Compared to the present study, previous investigations in Great Britain and Sweden have shown a maintenance of maximal skinfold values rather than a decrease during the second half of the first year. It is suggested that differences of feeding habits and calorie intake may be responsible for these discrepancies. The results of this mixed longitudinal study, performed in 1974/1975, were computed to calculate centile curves of the skinfold development in infancy, which may serve as standards for infants living under similar socioeconomic and nutritional conditions.