Replication of R6K gamma origin in vitro: discrete start sites for DNA synthesis dependent on pi and its copy-up variants

The regulation of the plasmid R6K gamma origin (gamma ori) is accomplished through the ability of the pi protein to act as an initiator and inhibitor of replication. Hyperactive variants of this protein, called copy-up pi, allow four to tenfold increases of gamma ori plasmid DNA in vivo. The higher activity of copy-up pi variants could be explained by an increase in the initiator function, a decrease in the inhibitor activity, or a derepression of a more efficient mechanism of replication that can be used by wt pi (pi35. 0) only under certain conditions. We have compared the replication activities of wt pi35.0 and copy-up pi mutants in vitro, and analyzed the replication products. It is shown that copy-up variants are several-fold more active than wt pi35.0 in replication. This appears to be due to enhanced specific replication activity of copy-up mutants rather than elevated fractions of protein proficient in DNA binding. Furthermore, biochemical complementation revealed that pi200 (copy-up) is dominant over wt pi35.0. The elevated activity of copy-up pi is not caused by an increased rate of replisome assembly as inferred from in vitro replication assays in which the lag periods observed were similar to that of wt pi35.0. Moreover, only one round of semiconservative, unidirectional replication occurred in all the samples analyzed indicating that copy-up pi proteins do not initiate multiple rounds of DNA synthesis. Rather, a larger fraction of DNA template replicates in the presence of copy-up pi as determined by electron microscopy. Two clusters of discrete DNA synthesis start sites are mapped by primer extension near the stability (stb) locus of the gamma ori. We show that the start sites are the same in the presence of wt pi35.0 or copy-up proteins. This comparative analysis suggests that wt pi35.0 and copy-up variants utilize fundamentally similar mechanism(s) of replication priming.

Genetic dissection of familial Parkinson's disease

In the past few years, the genetic contribution to Parkinson's disease (PD) has gained major attention and has resulted in the identification of the first mutant gene, called alpha-synuclein, involved in the pathogenesis of autosomal-dominant PD. alpha-Synuclein is a major component of Lewy bodies, which are a neuropathological feature of PD. Furthermore, deletions in the parkin gene have been identified as the primary cause in rare forms of autosomal-recessive juvenile PD. The elucidation of polygenic changes in the dopamine pathway, mitochondrial dysfunction, and metabolism of xenobiotics is now technically possible by means of association and genotype studies. The increasing knowledge of the pathogenesis of PD at a molecular level will have important implications for the development of individual therapeutic strategies to prevent disease progression.

Selegiline as immunostimulant--a novel mechanism of action?

In clinical studies the MAO-B inhibitor selegiline appears to slow the progression of neurological deficits in Parkinson's disease (PD) and the cognitive decline in Alzheimer's disease (AD). The mechanisms of action remain unclear. Several lines of evidence indicate an immune-mediated pathophysiology of PD and AD. According to animal trials, selegiline increases the survival rate of immune suppressed mice. Stimulation of the immune response to bacterial or viral infection or in chronic inflammatory processes in managed by an increased synthesis of the cytokines interleukin-1 beta (IL-1 beta) and subsequent interleukin-6 (IL-6). Outcome of viral or bacterial infections in the brain highly correlates with levels of the cytotoxic cytokine tumor-necrosis-factor-alpha (TNF). The aim of our study was to characterize the influence of selegiline on the biosynthesis of IL-1 beta, IL-6 and TNF in human peripheral blood mononuclear cells (PBMC) from healthy blood donors. After isolation and washing PBMC were cultured without and with selegiline in three different concentrations (0.01 mumol/l, 0.001 mumol/l, 0.0001 mumol/l) in a humidified atmosphere (7% CO2). Then cultures were centrifuged and supernatants were collected for IL-1 beta, IL-6 and TNF ELISA-assays. Treatment of cultured PBMC with various concentrations induced an increased synthesis of IL-1 beta (ANOVA F = 9.703, p = 0.0007), IL-6 (ANOVA F = 20.648, p = 0.0001) and a reduced production of TNF (ANOVA F = 3.770, p = 0.040). These results indicate, that the influence of selegiline on the cytokine biosynthesis may also contribute to its putative neuroprotective properties.

Spinocerebellar ataxia type 6: genotype and phenotype in German kindreds

OBJECTIVE

Spinocerebellar ataxia type 6 (SCA6) is an autosomal dominant cerebellar ataxia (ADCA) of which the mutation causing the disease has recently been characterised as an expanded CAG trinucleotide repeat in the gene coding for the alpha1A-subunit of the voltage dependent calcium channel. The aim was to further characterise the SCA6 phenotype

METHODS

The SCA6 mutation was investigated in 69 German families with ADCA and 61 patients with idiopathic sporadic cerebellar ataxia and the CAG repeat length of the expanded allele was correlated with the disease phenotype.

RESULTS

Expanded alleles were found in nine of 69 families as well as in four patients with sporadic disease. Disease onset ranged from 30 to 71 years of age and was significantly later than in other forms of ADCA. Age at onset correlated inversely with repeat length. The SCA6 phenotype comprises predominantly cerebellar signs in concordance with isolated cerebellar atrophy on MRI. Non-cerebellar systems were only mildly affected with external ophthalmoplegia, spasticity, peripheral neuropathy, and parkinsonism. Neither these clinical signs nor progression rate correlated with CAG repeat length.

CONCLUSIONS

This study provides the first detailed characterisation of the SCA6 phenotype. Clinical features apart from cerebellar signs were highly variable in patients with SCA6. By comparison with SCA1, SCA2, and SCA3 no clinical or electrophysiological finding was specific for SCA6. Therefore, the molecular defect cannot be predicted from clinical investigations. In Germany, SCA6 accounts for about 13% of families with ADCA. However, up to 30% of SCA6 kindreds may be misdiagnosed clinically as sporadic disease due to late manifestation in apparently healthy parents. Genetic testing is therefore recommended for the SCA6 mutation also in patients with putative sporadic ataxia.

Effects of fluvoxamine on depression, anxiety, and other areas of general psychopathology in bulimia nervosa

The efficacy of fluvoxamine in maintaining improvement of general psychopathology (depression, obsessive-compulsive symptoms, anxieties, interpersonal trust, and body perception) was tested in a double-blind placebo-controlled study of 72 patients with bulimia nervosa who were being treated successfully with inpatient behavioral psychotherapy. Over a period of about 15 weeks (2-3 weeks inpatient titration phase, 12 weeks outpatient relapse-prevention phase), fluvoxamine or placebo were given. The relapse-prevention design was used to avoid potential confounding effects of other concomitant treatments. Assessments concerning general psychopathology were made on the basis of expert ratings (CGI, HDRS) and self ratings (HSCL, Eating Disorders Inventory (EDI)-subscales "ineffectiveness," "perfectionism," "maturity fears," "interpersonal distrust," and "interoceptive awareness"). Fluvoxamine had significant effects in preventing relapse as measured on the basis of the Clinical Global Impression (CGI) scale "severity of illness", and a positive trend for relapse preventing effects was observed for the HSCL "general symptomatic index". Further, a relapse preventing effect was observed for the HSCL subscale "obsessive-compulsive symptoms", but not for the EDI subscale "perfectionism". Various dependent variables measuring depression showed no significant relapse-preventing effects of fluvoxamine, but only positive trends. Fluvoxamine had no relapse preventing effects according to our results for dependent variables assessing anxieties, interpersonal trust, and body perception. During a final short (4-week) off-medication phase, no statistically significant effects of discontinuation of medication, but some trends in the expected directions, were observed.

Mercury pollution and macrophage centres in pike (Esox lucius) tissues

From June 1993 to October 1994, studies have been carried out on the effects of mercury in the Oder River and pike tissue contamination (muscle, kidney, liver). The mean mercury contents in the sediment range from 0.03 to 1.1 mg/kg dry weight. In the pike muscle, between 0.22 and 0.85 mg/kg, on a wet weight basis, were found. The measured mercury concentrations were analysed in relation to the number of macrophage centres of the liver, spleen and kidney of the pike. Positive correlations between mercury and MC response (0.54 < or = r < or = 0.79, p < 0.05) were found in all of these organs. The suitability of the macrophage-centre-response as a possible bioindicator for mercury pollution is discussed in the literature. In our study, the response of MCs was found to be suitable as a biomarker for the impairment of fish health.

Selegiline stimulates biosynthesis of cytokines interleukin-1 beta and interleukin-6

Several lines of evidence indicate an immune-mediated pathophysiology of Parkinson's disease (PD) and Alzheimer's disease (AD). In clinical studies the monoamine oxidase-B inhibitor Selegiline appears to slow the progression of neurological deficits in PD and the cognitive decline in AD. The immune response to bacterial or viral infection and in chronic inflammatory processes is stimulated by an increased synthesis of the cytokines interleukin-1 beta (IL-1 beta) and subsequently interleukin-6 (IL-6). We investigated the influence of Selegiline on the synthesis of IL-1 beta and IL-6 in peripheral blood mononuclear cells (PBMC) from healthy blood donors cultured with or without Selegiline (10(-8)M, 10(-9)M or 10(-10)M) in a humidified atmosphere (7% CO2). Treatment of cultured PBMC with Selegiline significantly increased synthesis of both cytokines. The effect of Selegiline on cytokine biosynthesis may contribute to its putative neuroprotective properties.

Fluvoxamine in prevention of relapse in bulimia nervosa: effects on eating-specific psychopathology

In a double-blind, placebo-controlled study of 72 patients with bulimia nervosa treated successfully with inpatient psychotherapy, the efficacy of fluvoxamine in maintaining improvement was tested. Fluvoxamine and placebo, respectively, were given over a period of about 15 weeks (2-3 weeks inpatient titration phase, 12 weeks outpatient relapse-prevention [maintenance] phase). The variables assessed concerned bulimic behavior and other aspects of eating disorders, global status, depression, anxieties, obsessive-compulsive behavior, and other aspects of psychopathology. Because the dropout rate was relatively high (N = 27 [33%]) and because it was considerably higher in the fluvoxamine group (19 out of 37 subjects), analyses were performed on the intent-to-treat sample (ideally including all 72 subjects). Results of the completer sample analyses (including only those subjects who finished the study) are briefly presented for comparison. In both the intent-to-treat and the completer analyses, the following scales showed fluvoxamine to have a significant effect in reducing the return of bulimic behavior: (1) self-ratings: Eating Disorder Inventory (EDI)-bulimia, urges to binge in previous week and the number of actual binges in the previous week; (2) expert ratings: Psychiatric Status Rating Scales for Bulimia nervosa, Structured Interview for Anorexia and Bulimia nervosa (SIAB)-"total score," SIAB-subscale "fasting," and SIAB-subscale "vomiting." Two further variables (EDI-total score and SIAB-subscale "bulimia") showed the superior relapse prevention effects of fluvoxamine compared with placebo for the completer sample, while they did not reach significance for group-by-time interactions in the intent-to-treat sample. During a final, short (4-week) off-medication phase, no effect of the discontinuation of medication was observed.

[Quality management in the hospital with special reference to the medical departments]

Present German health legislation requires standardisation of systems and procedures not only for medical departments but for entire clinics as well. Changes in organisation and treatment possibilities should enable clinic administrations to better manage the quality of the services provided. This system of quality control and quality management is based on the introduction of ISO 9004, part 2. Medical and non-medical procedures are standardised and streamlined through flow-diagrams, the details of which are summarised in a series of quality handbooks with an emphasis on guidelines and standards. These handbooks are distributed clinic-wide, and although acceptance is not yet determined, objections are probable. Future analysis will show the effects due to quality management in the clinical setting.

Proteolytic processing of neuropeptide Y and peptide YY by dipeptidyl peptidase IV

Neuropeptide Y, peptide YY and pancreatic polypeptide share an evolutionary conserved proline-rich N-terminal sequence, a structure generally known to be inert to the attack of common proteinases, but a potential target for specialized proline-specific aminopeptidases. Purified human dipeptidyl peptidase IV (also termed CD 26) liberated N-terminal Tyr-Pro from both, neuropeptide Y and peptide YY, with very high specific activities and Km values in the micromolar range, but almost no Ala-Pro from pancreatic polypeptide. Other proline-specific aminopeptidases exhibited low (aminopeptidase P, liberation of N-terminal Tyr) or totally no activity (dipeptidyl peptidase II), as was also observed with less-specific aminopeptidases (aminopeptidase M, leucine aminopeptidase). When human serum was incubated with neuropeptide Y or peptide YY at micro- and nanomolar concentrations, Tyr-Pro was detected as a metabolite of both peptides. Formation of Tyr-Pro in serum was blocked in the presence of Lys-pyrrolidine and diprotin A (Ile-Pro-Ile), specific, competitive inhibitors of dipeptidyl peptidase IV. Incubation of neuropeptide Y or peptide YY with immunocytochemically defined, cultivated endothelial cells from human umbilical cord also yielded Tyr-Pro. Dipeptidyl peptidase IV could be immunostained on most endothelial cells by a specific antibody. We suggest that dipeptidyl peptidase IV might be involved in the degradation of neuropeptide Y and peptide YY to N-terminal truncated neuropeptide Y(3-36) and peptide YY(3-36). Since specific binding to Y1, but not to Y2 subtype of neuropeptide Y/peptide YY receptors requires intact N- as well as C-termini of neuropeptide Y and peptide YY, removal of their amino-terminal dipeptides by dipeptidyl peptidase IV inactivates them for binding to one receptor subtype.

[Malignant non-Hodgkin's lymphoma of the joint. Report of two cases, review of the literature and problems of classification]

This paper gives a survey of malignant Non-Hodgkin lymphomas (NHL) of joints. Primary and secondary malignant lymphomas of joints are rare. Our analysis of 6 years', new entries in the lymph node register in Kiel, covering 37.367 cases of malignant lymphomas, revealed only 20 cases (0.05%) with infiltration of joints. Slightly more men than women (1.18:1) are actually affected by articular lymphomas. In addition to 34 articular lymphomas of joints described in the literature between 1974 and 1992, we analyse 2 cases seen in our own institute and the 20 cases taken from the Kiel lymph node register. The peak incidence is between 40 and 60 years of age. One of our own cases, a woman of 92, is the oldest person ever affected. The most frequent localizations of NHLs are the knee, hip, and shoulder joints, with low-grade lymphomas predominating. Osteolytic lesions on radiographs are of decisive clinical and diagnostic significance for malignant articular lymphomas with affected bones. Lymphomas of joints are treated almost exclusively by radiation and chemotherapy, and sometimes a combination of both. Decisive prognostic significance attaches to the grade of malignancy and the fact of primary or secondary infiltration of the synovium and of the bone. The average survival time for patients with low-grade NHLs is 19 months with infiltration of the synovium and 27 months with infiltration of joint forming bones only, whereas the average survival time for patients high-grade lymphomas is 8 months with infiltration of the synovium and 11 months with infiltration only of joint-forming bones.(ABSTRACT TRUNCATED AT 250 WORDS)

Kinetics of antipyrine and sulfamethazine in patients recovered from dihydralazine-hepatitis

Pharmacokinetic studies with sulfamethazine (500 mg) and antipyrine (15 mg/kg) were performed in 27 hypertonic patients (16 females, 11 males, 37-78 years) who had recovered from a dihydralazine-induced hepatitis, and 21 patients with essential hypertension (13 females, 8 males, 18-74 years) treated with antihypertonics excluding dihydralazine. 20 patients of the hepatitis group (74%) and 12 patients of the control group (57%) were slow acetylators. With regard to the pharmacokinetic parameters no differences were found in both slow and rapid acetylators between the sulfamethazine group and the antipyrine group.

Influence of neuroleptics on the metabolism of tricyclic antidepressants--in vitro experiments with rat liver microsomes

The influence of two neuroleptics--the phenothiazine perazine and the butyrophenone haloperidol--on the metabolism of the tricyclic antidepressants amitriptyline (AMI), imipramine (IMI), and chlorimipramine (CMI) was studied in vitro in isolated liver microsomes of female Sprague-Dawley rats. The rats were pretreated over 10 days with either NaCl solutions or with 1, 3, and 10 mg/kg haloperidol or 5 and 15 mg/kg perazine, respectively. The microsomal fraction was incubated with various concentrations of antidepressants. The drugs and their metabolites were analyzed by high-performance liquid chromatography (HPLC). Neither pretreatment with haloperidol nor perazine had any significant influence on the demethylation and N-oxidation activity of the microsomes. Benzylic 10-hydroxylation of AMI or IMI or 10- and 11-hydroxylation of CMI was inhibited significantly by pretreatment with perazine, as was 2-hydroxylation of IMI and CMI, whereas 8-hydroxylation of CMI was not influenced. The inhibition was dose dependent. With haloperidol, only the high dose of 10 mg/kg caused a significant inhibition of benzylic 10-hydroxylation, whereas phenolic hydroxylation was not influenced. The inhibition was much lower than for perazine. Comparing the results with pharmacokinetic studies in humans revealed a good agreement in metabolic pathways. The study could therefore be important in the choice of neuroleptic drugs in combination therapy.

Comparison of the metabolism of the three antidepressants amitriptyline, imipramine, and chlorimipramine in vitro in rat liver microsomes

The metabolism of the tricyclic antidepressants amitriptyline (AMI), imipramine (IMI), chlorimipramine (CMI) and some of their metabolites was studied in vitro in isolated liver microsomes of female Spraque-Dawley rats. Nine metabolites of AMI, seven metabolites of IMI, and 11 metabolites of CMI were quantitatively determined with high-performance liquid chromatography. The main metabolic reactions, mediated by an NADPH generating system, were hydroxylation, demethylation, and N-oxidation. The ratio of these reactions was different for the three drugs. AMI was hydroxylated more than CMI and CMI more than IMI. The order for demethylation was CMI greater than AMI = IMI, the order for N-oxidation IMI greater than CMI less than or equal to AMI. The substrate dependence of metabolism was investigated. Demethylation and N-oxidation increased proportionally to increasing substrate concentrations, whereas formation of hydroxylated metabolites became saturated (in the concentration range of 10(-6)-10(-5) M). The in vitro metabolism was compared with the in vivo metabolism in humans, reflected by the plasma concentrations of these drugs and their metabolites. A good agreement in metabolic pathways was found.

Determination of benperidol in human plasma by high-performance liquid chromatography

A high-performance liquid chromatographic method for the quantitative determination of benperidol in human plasma using haloperidol as internal standard is described. The method involves liquid-liquid extraction, separation of the substances on a reversed-phase column C18 followed by ultraviolet detection at 254 nm. The mobile phase consists of 32% acetonitrile in 0.05 M potassium dihydrogen phosphate buffer (pH 2.8). The detection limit is 0.5-1.0 ng/ml using 2- or 4-ml plasma samples.

[Malignant blue nevus in Ota's nevus]

A 21-year-old Caucasian woman with congenital nevus of Ota developed a subcutaneous tumor below the lacrimal sack within the area of discoloration. The tumor, located subcutaneously, has been present for 4 years. Histologically, parts of the tumor showed neuroid structures as well as those like cellular blue nevus. In one part, however, malignant transformation features could be found.

[Wegener's granulomatosis]

A case of an unusual development of Wegener's granulomatosis is described. A long-term immunosuppressive therapy led to intermittent involution of the process, but finally a transformation to a new disease, for present qualified as "malignant histiocytosis" was the result. The cause of the transformation and the differentiation from other necrotising granulomas are discussed.

Sex dimorphism of the adrenal cortex in rats after treatment with dexamethasone

Sex dimorphism of adrenal cortex of the rat was studied by light and electron microscopy as well as the karyometric, gravimetric, and histometric methods after treatment with dexamethasone (2.0 mg/kg over a period of 4 days). Sex dimorphism cannot be shown in dexamethasone-induced atrophy of adrenal glands. Male fasciculata cells have more and finer distributed liposomes resembling in this way female fasciculata cells. Normally present differences in adrenal weight and nuclear size of fasciculata cells between both sexes disappear; nevertheless, female fasciculata cells remain relatively bigger compared to the corresponding male cells. Annulment of sex dimorphism is thought to be the result of altered functional activity of the zona fasciculata due to failing pituitary stimulation. Higher secretion activity of female fasciculata cells probably ceases after dexamethasone treatment.

[Prevention by metyrapone of halothane induced liver necrosis in rats (author's transl)]

Liver necrosis and an increase of serum sorbitol dehydrogenase activity can be produced in rats by halothane anesthesia (1% v/v in oxygen) following pretreatment with polychlorinated biphenyls. Using this model, it was shown that administration of metyrapone (2-methyl-1,2-bis(3-pyridyl)-1-propanone) (100 mg/kg b.w.) 1 h prior to anesthesia prevents liver necrosis and the concomitant increase in serum sorbitol dehydrogenase activity. No significant differences were observed when halothane was applied in air instead of oxygen, but the protective effect of metyrapone was abolished.

[Castleman's lymphoma (author's transl)]

Intrathoracic angiofollicular lymph node hyperplasia (Castleman's lymphoma) was found in a 32-year-old woman. The diagnosis could be established already preoperatively by endoscopic biopsy. It was a coincidental discovery as there were no clinical symptoms. Histologically the tumour was of the hyaline-vascular type. After uncomplicated surgical removal follow-up at 6 weeks was unremarkable. Aetiology and pathology of this rare disease are unknown.

[Cardiac effects of antikaliuretic diuretics-clinical and biochemical investigation (author's transl)]

Recently direct myocardial effects of antikaliuretic diuretics with respect to contractility parameters and prevention of digitalis-induced arrhythmias were published. In order to test the value of these reports we measured the effect of potassium-canrenoate and triamterene on cardiac output and on digitalis-induced arrhythmias in patients during diagnostic and the therapeutic flow directed right heart catheterization (Swan-Ganz) in our intensive care unit. In addition the influence of these drugs on (Na+ + K+)-ATPase and on (3H)g-strophanthin binding to human cardiac cell membranes was investigated to gain information on the mechanism of their action. Triamterene (100-200 mg p.o.) was without any effect on cardiac output, the same was found true for potassium-canrenoate given in a single dose (200-1000 mg intravenously). However, when applied in two doses (200 mg i.v. and 60 min later 400 mg i.v.), potassium-canrenoate increased cardiac output by 11 percent (p less than 0.05). Only in 2 out of 14 patients potassium-canrenoate (200-400 mg i.v.) suppressed digitalis-induced ventricular ectopic beats. Canrenone, the active metabolite of potassium-canrenoate displaces [(3H)]g-strophanthin from its binding sites in human cardiac cell membranes and inhibits (Na+ + K+)-ATPase activity. These in vitro effects were measured at the same concentrations as found in vivo after "therapeutical" doses. The effects of triamterene in this respect were found only in extremely high concentrations. Our results imply that canrenone has cardiac glycoside-like effects in human cardiac cell membranes.

[Pharmaco-kinetic investigations of a new gall bladder contrast medium--iodoxaminic acid (author's transl)]

Pharmaco-kinetic studies of the cholecystographic contrast medium iodoxaminic acid (Diglumin-Iodaxamate) which is characterised by low toxicity, revealed a half-value period of 93 minutes in the serum and a urinary excretion rate of 12.5% in 24 hours. This indicated the probability that this medium would be suitable for the radiological demonstration of the biliary tract when compared with known and tried contrast media.

[Mucouria in urachal adenoma (author's transl)]

Recurrent macrohematuria and massive mucous flow from the urethra have been observed in a 81-year-old woman. Cystoscopy reveals a tumor of about pea-size in the apex of the bladder, which is histologically classified as an urachal adenoma. Clinical aspects and pathogenesis are discussed.