Generation and activity of the ternary gelatinase B/TIMP-1/LMW-stromelysin-1 complex

Incubation of progelatinase B, isolated from human polymorphonuclear leukocytes, with TIMP-1 leads to the formation of the progelatinase B/TIMP-1 complex. This complex behaves like a Janus in a similar manner as we previously described for the progelatinase A/TIMP-2 complex. It shows the properties of TIMP-1 and is a better inhibitor for gelatinase A than for gelatinase B. Treatment with trypsin leads to activation of the binary complex. The activity, however, amounts only to slightly more than 10% of the activity of free gelatinase B, not complexed with TIMP-1. When the progelatinase B/TIMP-1 complex inhibits an active matrix metalloproteinase, a ternary complex is generated that after activation displays a distinct higher proteolytic activity than the active binary complex. The active binary complex cannot be transformed into the active ternary complex.

Efficient low redundancy large-scale DNA sequencing at EMBL

An efficient low redundancy DNA sequencing strategy should allow high accuracy determination of the consensus sequence on both strands of a DNA fragment from a minimal number of sequencing reactions with minimal overlap. At EMBL we developed a directed strategy for cosmid-scale sequencing based on primer walking, whereas most other sequencing projects of this scale rely on the random 'shotgun' strategy. In our strategy, highly accurate raw data are obtained from automated double-stranded Sanger dideoxy sequencing with inexpensive walking primers (8 to 10 $ per primer), T7 DNA polymerase and internal labelling by fluorescein-15- dATP on A.L.F. DNA sequencers (Pharmacia Biotech). The use of 60-cm long glass plates enables reading length of up to 1000 bases. Comparing various random and directed sequencing strategies in the course of the European Community yeast genome sequencing project on cosmids from chromosomes IX, XI and XV, primer walking was found to be the strategy resulting in the lowest possible redundancy of 2.6 to 2.8. Future development of the sequencing strategy is based on the new EMBL 2-dye sequencing device for simultaneous sequencing on both strands, and implementation of an initial limited random sequencing phase to reduce the number of walking primers required by a factor of 3, while still maintaining a low redundancy of approx. 3.

New reactive coenzyme analogues for affinity labeling of NAD+ and NADP+ dependent dehydrogenases

Reactive coenzyme analogues omega-(3-diazoniumpyridinium)alkyl adenosine diphosphate were prepared by reaction of omega-(3-aminopyridinium)alkyl adenosine diphosphate with nitrous acid. In these compounds the nicotinamide ribose is substituted by hydrocarbon chains of varied lengths (n-ethyl to n-pentyl). The diazonium compounds are very unstable and decompose rapidly at room temperature. They show a better stability to 0 degree C. Lactate and alcohol dehydrogenase do not react with any of the analogues. Glyceraldehyde-3-phosphate dehydrogenase reacts rapidly with the diazoniumpentyl compound. Decreasing the length of the alkyl chain significantly decreases the inactivation velocity. 3 alpha, 20 beta-Hydroxysteroid dehydrogenase reacts at 0 degree C with the ethyl homologue and slowly with the propyl compound. The butyl- and pentyl analogues do not inactivate at 0 degree C. Tests with 14C-labeled 2-(3-diazoniumpyridinium)ethyl adenosine diphosphate show that complete loss of enzyme activity results after incorporation of 2 moles of inactivator into 1 mole of tetrameric enzyme. 4-(3-Acetylpyridinium)butyl 2'-phospho-adenosine diphosphate, a structural analogue of NADP+, was prepared by condensation of adenosine-2,3-cyclophospho-5'-phosphomorpholidate with (3-acetylpyridinium)butyl phosphate, followed by hydrolysis of the cyclic phosphoric acid with 2':3'-cyclonucleotide-3'-phosphodiesterase. Because of the redox potential (-315 mV) and the distance between the pyridinium and phosphate groups, this analogue is a hydrogen acceptor and its reduced form a hydrogen donor in tests with alcohol dehydrogenase from Thermoanaerobium brockii. The reduced form of the coenzyme analogue also is a hydrogen donor with glutathione reductase. With other NADP+-dependent dehydrogenases the compound has been shown to be a competitive inhibitor against the natural coenzyme. The acetyl group reacts with bromine to form the bromoacetyl group. This reactive bromoacetyl analogue is a specific active-site directed irreversible inhibitor of isocitrate dehydrogenase.

Structure and role of the terminal repeats of Epstein-Barr virus in processing and packaging of virion DNA

The linear virion Epstein-Barr virus (EBV) DNA is terminated at both ends by a variable number of direct, tandemly arranged terminal repeats (TRs) which are approximately 500 bp in size The number of TRs at each terminus can vary. After infection of host cells, the EBV DNA circularizes via the TRs by an unknown mechanism, and replication of the viral DNA during the lytic phase of the EBV life cycle leads to large DNA concatemers which need to be cleaved into virion DNA units, eventually. This cleavage event occurs at an unknown locus within the TRs of EBV, which are the cis-acting elements essential for cleavage of the concatemers and encapsidation of the virion DNA. To investigate the mechanism of DNA processing during genome circularization and cleavage of concatemeric DNA, the genomic termini of EBV were cloned, sequenced, and analyzed by direct labeling of the virion DNA. Both termini ended with identical 11-bp elements; the right end has acquired an additional 9-bp stretch that seemed to originate from the leftmost unique sequences. The left terminus is blunt, whereas the right terminus appears to have a 3' single-base extension. In a transient packaging assay, a single terminal repeat was found to be sufficient for encapsidation of plasmid DNA, and mutagenesis of the TR element defined a region of 159 bp, including the 11-bp element, which is essential for packaging. These results indicate that the genomic termini of EBV are not generated by a simple cut of a hypothetical terminase. The mechanism for cleavage of concatemers seems to involve recombination events.

Primer design for automated DNA sequencing utilizing T7 DNA polymerase and internal labeling with fluorescein-15-dATP

We have identified additional criteria for the walking primer design that improve the success rate of automated fluorescent DNA sequencing using the internal labeling technique and T7 DNA polymerase. These criteria resulted from the evaluation of over 220 sequences generated with walking primers and fluorescein-15-dATP as internal label in the course of the European Community (EC) yeast genome sequencing project. In this project primers were designed using standard commercial software. Intensities of sequencing signals varied over a broad range from very strong to very weak, depending on the primers used. This led us to evaluate primer performance relative to (i) the template sequence immediately downstream of the primer binding site and (ii) the primer sequence itself. Our experiments show that the position of the first labeled dATP to be incorporated downstream of the primer into the growing strand is substantial for the signal intensity of the sequence. The closer to the primer that the first 'A' is incorporated, the stronger the peak intensities are. An additional feature of sequencing with native T7 DNA polymerase is its ability to remove a 3'-terminal 'A' of the primer by the 3'-->5' exonuclease activity and to exchange the nucleotide with a labeled dATP by the polymerase activity.

Selective inhibition of the platelet-derived growth factor signal transduction pathway by a protein-tyrosine kinase inhibitor of the 2-phenylaminopyrimidine class

The platelet-derived growth factor (PDGF) receptor is a member of the transmembrane growth factor receptor protein family with intrinsic protein-tyrosine kinase activity. We describe a potent protein-tyrosine kinase inhibitor (CGP 53716) that shows selectivity for the PDGF receptor in vitro and in the cell. The compound shows selectivity for inhibition of PDGF-mediated events such as PDGF receptor autophosphorylation, cellular tyrosine phosphorylation, and c-fos mRNA induction in response to PDGF stimulation of intact cells. In contrast, ligand-induced autophosphorylation of the epidermal growth factor (EGF) receptor, insulin receptor, and the insulin-like growth factor I receptor, as well as c-fos mRNA expression induced by EGF, fibroblast growth factor, and phorbol ester, was insensitive to inhibition by CGP 53716. In antiproliferative assays, the compound was approximately 30-fold more potent in inhibiting PDGF-mediated growth of v-sis-transformed BALB/c 3T3 cells relative to inhibition of EGF-dependent BALB/Mk cells, interleukin-3-dependent FDC-P1 cells, and the T24 bladder carcinoma line. When tested in vivo using highly tumorigenic v-sis- and human c-sis-transformed BALB/c 3T3 cells, CGP 53716 showed antitumor activity at well-tolerated doses. In contrast, CGP 53716 did not show antitumor activity against xenografts of the A431 tumor, which overexpresses the EGF receptor. These findings suggest that CGP 53716 may have therapeutic potential for the treatment of diseases involving abnormal cellular proliferation induced by PDGF receptor activation.

Heparan sulfate primed on beta-D-xylosides restores binding of basic fibroblast growth factor

Heparan sulfate proteoglycans (HSPG) are obligatory for receptor binding and mitogenic activity of basic fibroblast growth factor (bFGF). Mutant Chinese hamster ovary cells (pgsA-745) deficient in xylosyltransferase are unable to initiate glycosaminoglycan synthesis and hence can not bind bFGF to low- and high-affinity cell surface receptors. Exposure of pgsA-745 cells to beta-D-xylopyranosides containing hydrophobic aglycones resulted in restoration of bFGF binding in a manner similar to that induced by soluble heparin or by heparan sulfate (HS) normally associated with cell surfaces. Restoration of bF-GF binding correlated with the ability of the beta-D-xylosides to prime the synthesis of heparan sulfate. Thus, both heparan sulfate synthesis and bFGF receptor binding were induced by low concentrations (10-30 microM) of estradiol-beta-D-xyloside and naphthyl-beta-D-xyloside, but not by cis/trans-decahydro-2-naphthyl-beta-D-xyloside, which at low concentration primes mainly chondroitin sulfate. The obligatory involvement of xyloside-primed heparan sulfate in restoration of bFGF-receptor binding was also demonstrated by its sensitivity to heparinase treatment and by the lack of restoration activity in CHO cell mutants that lack enzymatic activities required to form the repeating disaccharide unit characteristic of heparan sulfate. Xyloside-primed heparan sulfate binds to the cell surface. Restoration of bFGF receptor binding was induced by both soluble and cell bound xyloside-primed heparan sulfate and was abolished in cells that were exposed to 0.5-1.0 M NaCl prior to the bFGF binding reaction. These results indicate that heparan sulfate chains produced on xyloside primers behave like heparan sulfate chains attached to cellular core proteins in terms of affinity for bFGF and ability to function as low-affinity sites in a dual receptor mechanism characteristic of bFGF and other heparin-binding growth promoting factors.

[The use of contrast media for quality assurance in radiotherapy planning]

PURPOSE

The target volume definition in radiation therapy was evidently improved by CT and MRI. Basis of treatment planning, however, remains the therapy simulator. Important instruments for adequate fluoroscopic treatment planning are contrast media that recently have been applied less out of legal and professional reasons. Aim of this work is to evaluate the possible benefit of contrast media applications.

PATIENTS AND METHODS

In 1303 simulations between 1.1.1993 and 30.9.1993 105 times intravenous contrast media were applied, supplied by oral or endolymphatic contrast agents. It was studied if the previously intended plan had to be altered due to contrast media application.

RESULTS

In 17 out of 105 cases (16.2%) the target volume or the preplanned technique had to be altered after contrast media application. Main reason was the existence of anatomical variations especially in kidney and small bowel detected by use of contrast agents. So standard indications for contrast media applications were defined.

CONCLUSIONS

Contrast media are an important tool in treatment planning that should be orientated on diagnostical standards. Applications of contrast agents facilitate the detection of anatomical variations and the selection of the appropriate technique in order to shield sensitive tissues. The therapeutical and legal benefit outweigh potential hazards due to intolerances or professional obstacles.

Nucleotide sequence and analysis of the centromeric region of yeast chromosome IX

We have determined the nucleotide sequence of a cosmid (pIX338) containing the centromere region of yeast (Saccharomyces cerevisiae) chromosome IX. The complete nucleotide sequence of 33.8 kb was obtained by using an efficient directed sequencing strategy in combination with automated DNA sequencing on the A.L.F. DNA sequencer. Sequence analysis revealed the presence of 17 open reading frames (ORFs), four of them previously known yeast genes (sly12, pan1, sts1 and prl1), a tRNA gene and the centromere motif. Exhaustive database searches detected sequence homologues of known function for as many as 14 of the 17 ORFs. These include a mammalian tyrosine kinase substrate; the Escherichia coli cell cycle protein MinD; the human inositol polyphosphate-5-phosphatase (gene OCRL) involved in Lowe's syndrome, a developmental disorder; and helicases, for which the new yeast member defines a distinct DEAD/H-box subfamily. A surprisingly large fraction of the ORFs (at least six out of 17) in the centromeric region are apparently involved in RNA or DNA binding.

Effects of urodilatin and diltiazem on renal function in ischemic acute renal failure in the rat

In humans as well as in experimental models the hallmark of ischemic acute renal failure (ARF) is a profound diminution in glomerular filtration rate (GFR) and renal blood flow. Both calcium antagonists and a-ANP have been reported to exert beneficial effects in ischemic ARF. No data, however, exist about combined administration of the natriuretic peptide urodilatin and calcium channel blockers. We therefore investigated the effects of urodilatin (URO, 40 micrograms/kg/h, i.v.) and diltiazem (DIL, 300 micrograms/kg/h, i.v.) in the rat given immediately after clamping of both renal arteries for 40 min. Compared to controls (0.07 +/- 0.01) depressed GFR (ml/min/100 g) was clearly elevated with URO (0.16 +/- 0.03), DIL (0.13 +/- 0.03) and URO + DIL (0.14 +/- 0.02) after the ischemic lesion. After cessation of drug delivery the beneficial effects were blunted in the URO group, in contrast to the DIL and URO + DIL group, where GFR was significantly elevated compared to controls even 3 h after starting reperfusion. Besides that also urine flow, sodium excretion and blood pressure were examined. In conclusion both URO and DIL exert beneficial effects in ischemic ARF in the rat while infused. In contrast to URO DIL showed prolonged beneficial effects even after cessation of drug delivery. An additional effect of both drugs could not be observed.

Simultaneous on-line DNA sequencing on both strands with two fluorescent dyes

We describe an automated DNA-sequencing technique which allows both the simultaneous sequencing from the two strands of double-stranded templates and the subsequent detection of the sequencing products online and in parallel. The technique is based on hardware technology also used in the ALF DNA sequencer (Pharmacia, Uppsala). A helium-neon laser was mounted into the sequencing device additionally to the standard argon laser. Two different primers, labeled with either fluorescein or Texas red, are used in a single sequencing reaction resulting in an output of two sequences. Both sequencing products are then analyzed on-line in the same lanes of a gel. This technique is especially useful for the complete sequencing of DNA fragments up to 1 kb. High accuracy sequencing of PCR products in double-stranded form can now be accomplished in only one sequencing reaction.

[The Gitelman syndrome--a differential diagnosis of Bartter syndrome]

BACKGROUND

Hypokalemia due to renal potassium wasting in the absence of hypertension, moderate metabolic alkalosis, hyperreninism and hyperaldosteronism suggest the presence of Bartter's syndrome. The underlying cause is an inherited defect of sodium chloride reabsorption in the thick ascending limb of Henle. A differential diagnosis of Bartter's syndrome is Gitelman's syndrome, another hypokalemia-hypomagnesemia syndrome, which is thought to be caused by a transport defect in the distal tube.

PATIENTS AND METHODS

We report 3 patients presenting with signs primarily suggestive of Bartter's syndrome, who turned out to have Gitelman's syndrome after determining the excretion of calcium in the urine.

RESULTS

Two women, 36- and 55-year old, suffered from paresthesias in the hands and feet and from tetanic convulsions. The brother of the 36-year old woman presented in our hospital because of an accidentally discovered hypokalemia without any clinical symptoms. In all patients the outstanding biochemical features were hypokalemia, hypomagnesemia and moderate metabolic alcalosis. The renin and aldosterone values were inappropriately high. The most characteristic finding in the urine, besides the presence of hyperkaliuria was the diminution of calcium excretion, despite normocalcemia.

CONCLUSION

The association between sodium and calcium reabsorption in the loop of Henle predicts hypercalciuria in patients with a defect in salt reabsorption in this segment, as in Bartter's syndrome. In Gitelman's syndrome the laboratory features resemble the findings in Bartter's syndrome, except for the presence of hypocalciuria. Since hypocalciuria follows also the administration of thiazide diuretics, which act in the early part of distal tube, a transport defect in this part of the tube is thought to be responsible for the electrolyte disturbances in Gitelman's syndrome. The measurement of the urinary calcium excretion in patients with an unclear hypokalemia-hypomagnesemia-syndrome allows easily the differentiation between Bartter's and Gitelman's syndrome.

[Photo-brine therapy in patients with psoriasis and neurodermatitis atopica]

The effectiveness of salt water baths and subsequent selective ultraviolet phototherapy (SUP) was investigated in a prospective study on 40 patients with psoriasis vulgaris and atopic dermatitis. There were two groups with 20 patients each. The first group was treated with salt water (15%) that contained synthetic Dead Seas salt called "Psorisal"; the patients in the second group had a bath in a 3% NaCl solution. After 4 weeks of daily treatment, we found that 80% of the patients in the group treated with "Psorisal" had significantly better results than the second group. The subjective feeling of being ill had decreased significantly in both groups by the end of the study. The only side effect we found was the occurrence of sunburn in few cases, but this occurred significantly less in the "Psorisal" group. Both groups generally accepted the balneophototherapy, so it can easily be employed on an outpatient basis.

Improved fluorescent cycle sequencing protocol allows reading nearly 1000 bases

Recently available thermostable DNA polymerases result in enhanced resolution and accuracy compared to thermal enzymes used previously in fluorescent cycle sequencing. These new enzymes produce less variations in peak intensities, enhance gel resolution and are less sensitive to unspecific termination caused by either DNA structure or impurities in the DNA preparation. Optimization of nucleotide ratios and the usage of high concentrations of detergents in the sequencing reaction result in sequence readings up to 1000 bases and improve overall reliability of the sequencing protocol; this works successfully in about 90% of cases.

Complete DNA sequence of yeast chromosome XI

The complete DNA sequence of the yeast Saccharomyces cerevisiae chromosome XI has been determined. In addition to a compact arrangement of potential protein coding sequences, the 666,448-base-pair sequence has revealed general chromosome patterns; in particular, alternating regional variations in average base composition correlate with variations in local gene density along the chromosome. Significant discrepancies with the previously published genetic map demonstrate the need for using independent physical mapping criteria.

Design, synthesis and investigation of mechanisms of action of novel protein kinase C inhibitors: perylenequinonoid pigments

A series of perylenequinonoid pigments (PQPs) and related compounds were synthesized and screened for the inhibition of protein kinase C (PKC), a key enzyme involved in cellular differentiation and proliferation, and a potential target for anticancer and antiviral chemotherapeutic drugs. This study has established PQPs as efficient PKC inhibitors, and elucidated aspects of the light-enhanced action mode of the PKC inhibitors. Comparative studies between natural and synthetic PQPs led to the recognition of the effect of certain structural features of PQPs on PKC inhibition, including the skeleton of the 3,10-dihydroxy-4,9-perylenequinonoid chromophore and the configuration of the two side chains at positions 1 and 12. Calphostin C was identified as a superior PKC inhibitor of the POP class, and with the latter as a representative structure, we investigated the mechanism of PKC inhibition by PQPs via electron paramagnetic resonance spectroscopy in conjunction with the spin-trapping technique, absorption and fluorescence spectroscopy, photochemical and photobiological studies, and enzyme methodology. Multiple modes of action are suggested for PKC inhibition, comprising the following steps: (1) the binding of PQPs to the PKC regulatory domain via complexation; (2) the photobonding between mercapto groups of PKC cysteine residues and the PQP quinonoid moiety; and (3) the PQP-sensitized photodamage of PKC via Type I and/or Type II photosensitization.

Toxic acute renal failure in the rat: effects of diltiazem and urodilatin on renal function

Beneficial effects of natriuretic peptides have been reported in different models of acute renal failure (ARF). Calcium antagonists can also improve renal function, especially in ischemic models of ARF. The aim of our study was to investigate the effects of urodilatin and diltiazem alone and in combination in uranyl nitrate-induced toxic ARF in the rat. Three hours after induction of ARF glomerular filtration rate (GFR) was clearly diminished to about 50% compared to basal values. Intravenous infusion of diltiazem and urodilatin revealed a significant increase of GFR that even continued after cessation of drug delivery. Combined administration of urodilatin and diltiazem had no additional effect, probably due to a more pronounced fall in blood pressure in this group. Besides their vasorelaxing and blood pressure lowering effects both drugs also revealed diuretic activity. In conclusion both urodilatin and diltiazem are able to elevate GFR in the early phase of toxic ARF in the rat.

Role of L-arginine-derived NO in ischemic acute renal failure in the rat

Nitric oxide (NO) is involved in the regulation of renal perfusion and glomerular hemodynamics under basal conditions. We examined the hypothesis that L-arginine-derived NO modifies ischemic acute renal failure (ARF) in the rat. After a basal period ischemia was induced by clamping of both renal arteries (40 min). Thereafter, in the reperfusion period, we intravenously infused L-arginine (Arg, 300 mg/kg/60 min), or L-monomethylarginine (MeArg, 30 mg/kg/60 min), or Arg + MeArg (300 mg/kg/60 min, 30 mg/kg/60 min, resp.). Besides monitoring of urinary flow rate and arterial blood pressure, and determination of sodium excretion, glomerular filtration rate (GFR, mL/min/100 g) was estimated at the end of the infusion period and again after another 30 and 120 min by inulin clearance (fluorescence-marked inulin). In the basal period GFR showed no differences between the groups (Arg: 0.86 +/- 0.07, MeArg: 0.92 +/- 0.06, Arg + MeArg: 0.89 +/- 0.08, control: 0.84 +/- 0.07). At 180 min after the beginning of the reperfusion period, GFR was 0.13-0.02 in the control group. After administration of Arg, a remarkable and persistent increase in GFR was observed (0.28 +/- 0.03), whereas infusion of MeArg showed no significant effects (0.13 +/- 0.04). Combined administration of Arg + MeArg revealed a moderate increase of GFR (0.19 +/- 0.05), ranging between the Arg and the control group. Also, 60 and 90 min after the beginning of the reperfusion period, the highest values for GFR were obtained in the Arg group. We conclude that in this model of ischemic ARF in the rat, L-arginine-derived NO is capable of improving renal function. These data underline the regulatory role of the L-Arg-NO pathway for renal function, not only under normal conditions, but also in ARF.

Separation of up to 1000 bases on a modified A.L.F. DNA sequencer

Images

Sequencing and analysis of 51.6 kilobases on the left arm of chromosome XI from Saccharomyces cerevisiae reveals 23 open reading frames including the FAS1 gene

We have sequenced two segments containing a total of 51.6 kb of the left arm from chromosome XI of Saccharomyces cerevisiae. The first segment of 38.5 kb contains 18 open reading frames (ORFs) of more than 100 amino acid residues. Five ORFs encode known yeast genes, including the fatty acid synthase gene (FAS1). Three new yeast genes were discovered with homologies to non-yeast genes and ten new genes without homologies to any known sequences. The second segment of 13 kb contains five ORFs with two known yeast genes and three unknown genes. The sequences from cosmid pUKG041 were obtained entirely with the walking primer strategy resulting in a very low overall sequence redundancy of 2.8 and an average reading length of 443 bases.

Automated low-redundancy large-scale DNA sequencing by primer walking

Low-redundancy automated DNA sequencing by primer walking is described. T7 DNA polymerase is used together with computer-selected walking primers and fluorescein-dATP as internal label to sequence large plasmids or cosmids directly on a standard DNA sequencer with an error rate below 1% up to 500 bases (in the unedited raw data). The low error rate allows efficient sequencing with low (2-3 times) redundancy. Plasmid subclones covering 20 kb of a cosmid insert were sequenced with an overall redundancy of 2.7 in the course of the European community Saccharomyces cerevisiae genome sequencing project. Neighboring plasmid subclones were linked by direct cosmid sequencing. Sets of ten walking primers are synthesized on the EMBL multiple segmental DNA synthesizer at low costs and used for sequencing with greater than 95% efficiency. The accuracy of the directed approach is improved by simultaneous walking on both strands by designing two primers in opposite directions in the same starting region. One primer is used to confirm sequence data on the opposite strand, and the other primer to obtain new sequence data.

Outbred mice infected by an encephalomyocarditis virus variant: a model for studying chronic viral heart disease

Male 8 to 20-week-old NMRI mice (an outbred strain) infected with the encephalomyocarditis virus (EMCV) plaque variant (PV) 7 consistently develop a distinct myocarditis with a relatively low mortality (21%). Myocarditis occurs in essence independent of the virus dose applied, and other internal organs are not affected. Nevertheless, 3.5-week-old NMRI mice perished within 5 days of virus inoculation and exhibited disseminated myofibrillar degeneration (MFD); this obviously virus-induced myocardial damage was accompanied by scanty inflammatory infiltrates. EMCV PV7 infection of adult male C57Bl/6 and DBA/2 mice causes myocarditis comparable to that seen in NMRI mice. In DBA/2 mice, however, the virus-induced myocardial necrosis is complicated by subtotal calcification. This strain has a genetically determined "spontaneous" calcification of the myocardium, as shown by the study of uninfected controls. EMCV PV7-infected NMRI mice appear a promising model for study of long-term effects of viral myocarditis, possibly including cardiomyopathy. Furthermore, this outbred mouse strain offers the possibility of examining the pathogenesis of direct viral cytolysis and its relation to MFD as well as immunologically mediated cell damage.

[Perioperative cardiovascular reactions and the noradrenaline plasma level in patients on chronic antidepressant medication]

It is still controversial whether the perioperative incidence of cardiovascular complications is increased in patients on chronic treatment with cyclic antidepressants (AD) and whether AD medication should be discontinued prior to surgery. METHODS. We measured perioperative cardiovascular variables in 31 patients on chronic treatment with tri- and tetracyclic AD and 31 patients without AD medication. Heart rate, blood pressure, and noradrenaline plasma concentrations were compared between the two groups at nine points in time. During induction of anaesthesia, the ECG was recorded continuously. After the administration of 0.01 mg/kg atropine i.v., all patients received opiate-supplemented enflurane anaesthesia.

RESULTS

Re-uptake inhibition of noradrenaline by AD resulted in significantly higher noradrenaline plasma concentrations before and during anaesthesia in the AD-treated group. The incidence of arrhythmias, blood pressure elevations, and tachycardia was not increased in patients in AD treatment. Arrhythmias during induction of anaesthesia were seen in 6 of the AD-treated patients and 5 of the controls. Blood pressure elevations by more than 35% were seen in 10 patients on AD treatment and 8 controls. The heart rate prior to induction of anaesthesia and 2 h after the end of surgery was significantly higher in the AD-treated group. During anaesthesia the heart rate was higher at two points in time only. The incidence of tachycardia was similar in both groups. Intravenous administration of 0.01 mg/kg atropine prior to induction of anaesthesia increased the heart rate of the patients on chronic AD medication by 11.4%. This increase was significantly higher in the control group (16.2%), suggesting that patients with chronic AD treatment do not have a higher sensitivity to atropine.

CONCLUSION

The elevated noradrenaline plasma levels in patients on chronic AD treatment did not result in a higher incidence of arrhythmias, blood pressure elevations, or tachycardia perioperatively. Taking these results into account, we do not consider it necessary to discontinue chronic AD medication prior to surgery in patients without cardiovascular disease.

Acute endocrine failure after brain death?

After brain death, 32 potential organ donors were studied to determine serum and plasma concentrations of hypothalamic-pituitary hormones, thyroid hormones, and cortisol over a period of up to 80 hr. Diagnosis of brain death was established either on the basis of clinical criteria (n = 16) or by angiography (n = 16). While 78% of the organ donors developed diabetes insipidus, none of the circulating hormones of the anterior pituitary gland showed a progressive decline in concentration according to their plasma half-lives. With the exception of arginine vasopressin (AVP), no hormone concentration was found to be subnormal due to the onset of brain death. The subnormal free triiodothyronine (FT3) values in 62% of cases (median FT3 of 2.2 pmol/L within the first 24 hr) and the cortisol concentration of 6.9 micrograms/dl correlate with the frequency of similar findings in patients with severe head injuries. While the adrenocorticotropic hormone (ACTH) concentrations of 10-53 pg/ml remained constant during the study period, thyroid-stimulating hormone (TSH) and human growth hormone (hGH) concentrations showed a 12- and 35-fold increase from baseline values after 30-40 hr. These results suggest that, despite the now generally accepted criteria of brain death, there is still some residual function, and thus also perfusion of the hypothalamic-pituitary neuroendocrine system. This residual function appears to be sufficient to maintain hormonal plasma levels at least in the low reference range in most donors. Hormonal depletion in organ donors subsequent to brain death, as suggested repeatedly in the literature, could not be confirmed. The analysis of serum or plasma concentration patterns of a number of hormonal parameters following brain death does not support the rationale for a routine replacement therapy of total triiodothyronine (TT3) or cortisol to maintain endocrine homeostasis prior to organ harvest. However, dexamethasone therapy may be followed by suppression of the adrenal cortex of the organ donor. In these cases, cortisol substitution may be indicated.

High-throughput automated DNA sequencing facility with fluorescent labels at the European Molecular Biology Laboratory

One of the aims of the facility is to develop and push the automated on-line DNA sequencing gel technology to its limit in sequence throughput, which may be somewhere around 100 kilobases of sequence per device per day. Key new developments were initiated and applied in operation on the European Molecular Biology Laboratory (EMBL) automated sequencer and its commercial version A.L.F. (Pharmacia). Sequencing speed was increased by a factor of 10-20, up to 1500 bases per hour per clone on ultrathin (about 100 microns) gels, while the resolution and reading length were extended to 1000 bases on gels with 50 cm separation length, using fluorescein-15-*dATP as the internal label. With our sequencing strategy, closing about 40% of the sequence with "walking" primers and F-15-*dATP as internal label, we sequenced both strands of a cosmid insert of 38.5 kb in length, each strand twice, in only 430 sequencing reactions and with average reading of 380 bases per reaction.

Hemodynamic responses to noxious stimuli in brain-dead organ donors

The case report presents evidence for the spinal origin of the marked hypertensive responses to noxious stimuli that may occur in organ donors who fulfill the commonly accepted criteria of brain death. Cardiovascular spinal reflex activity does not invalidate these criteria. For the first time, the catecholamine plasma concentrations have been determined during spinal pressor reflex activity. Circulating epinephrine increased more markedly than norepinephrine in both cases, rising to 4.7 and 44 times the baseline concentration respectively. The relation between plasma norepinephrine and epinephrine suggests involvement of the adrenal medulla in the reflex arc. The literature on spinal hemodynamic reflexes is reviewed.

[Musical-verbal hallucinations and their correlation with electroencephalography and PET findings. Case report]

A case is reported of an organic auditory hallucinosis and depressive episode in a man aged 52. A new finding is the correlation of the musical hallucinosis to a central nervous disorder as shown by pathological sphenoidal EEG and 18FDG-PET-examination and not to acquired peripheral hearing deficit as often reported before.

Amide isosteres of lexitropsins: synthesis, DNA binding characteristics and sequence selectivity of thioformyldistamycin

The synthesis and properties of an amide isostere of the antibiotic distamycin, thioformyldistamycin 3 is described. Compound 3 exists predominantly in the E conformation of the thioamide group in freshly prepared DMSO solution but is converted into the Z form, predicted by molecular mechanics to be more stable, on standing for 24 h. The coalescence temperature in DMSO is 110 degrees C by 1H-NMR. The thioformyl moiety of 3 is resistant to both peptidase action and acid treatment. Complementary strand MPE footprinting on a EcoRI/Hind III restriction fragment of pBR322 DNA demonstrated that either E or Z forms of 3 give a single set of footprints very similar to that of the parent antibiotic with strongest protection at TAAG and TATTAT with moderately strong protection at ATTT and AAAA. The strength of binding of 3 and distamycin from delta Tm measurements to either poly.d(AT) or calf thymus DNA is comparable. Molecular modeling predicted a preferred conformation for 3 wherein the C = S bond has a torsional angle of 110 degrees with the pyrrole ring. The energy difference between this conformation and the E form is less than 1 kcal/mole. In contrast the E-form has an energy 17.3 kcal/mole greater than the Z and a value of 26.3 kcal/mole was calculated for the energy barrier between the two isomers.

[The value of symptoms and clinical findings in cervical Chlamydia trachomatis infection]

The frequency of symptoms in the case histories of 68 female patients with and of 313 without Chlamydia trachomatis infections was investigated. Dysuria, vaginal discharge and/or burning/itching in the genital region were reported by 50% (n = 34) of chlamydia-positive women and 53.7% (n = 168) of chlamydia-negative women. Clinical investigation of the chlamydia-positive patients revealed discharge in 83.8% (n = 57), contact bleeding in 38.3% (n = 26) and ectopia in 27.9% (n = 19). The corresponding investigations in chlamydia-negative women disclosed discharge in 72.8% (n = 228) women, contact bleeding in 19.8% (n = 62) and ectopia in 16.8% (n = 52). The results were significantly different as far as contact bleeding and ectopia were concerned. Only when yellow or whitish yellow discharge was distinguished from clear discharge was the difference between the two groups significant (66.7% vs 43.9%). Significant numbers of polymorphonuclear leucocytes (greater than 4 per high power field with oil immersion) were found in 52.9% of the chlamydia-positive women, as against 23% of the chlamydia-negative women. Overall, 48.7% of the women with a C. trachomatis infection were found to have notes of symptoms in the history and signs of cervicitis revealed by clinical investigation. Symptoms only were found in 1 woman, while in 36.8% of the patients signs only were found. Neither symptoms nor signs were mentioned by 13.3% of the women. These results indicate that microbiological detection of the infectious agent is obligatory for the diagnosis of C. trachomatis cervicitis.

Structure of the gene encoding human casein kinase II subunit beta

Casein kinase II (CKII) is a ubiquitous serine/threonine protein kinase with numerous key functions in cell metabolism and growth. The human CKII has a tetrameric structure; two catalytic subunits (alpha and alpha') form the holoenzyme together with two presumably regulatory subunits (beta). The gene encoding CKII subunit beta was isolated from human genomic DNA and analyzed for its primary structure using exclusively nonradioactive procedures. The gene was found to span 4.2 kilobase pairs and to be composed of seven exons. Exon sizes range from 76 (exon 5) to 329 base pairs (bp) (exon 1), intron sizes from 145 (intron V) to 965 bp (intron II). All exon-intron junctional sequences conform to the canonical GT-AG rule. Primer extension analysis determined three transcription initiation sites, at 951, 919, and (minor) 840 bp upstream of the translation start site. The translation start is located early in the second exon; exon 1 is untranslated. The 3'-cleavage/polyadenylation signal sequence (AA-TAAA) is in the last exon at position 4173 bp relative to the first transcription initiation site. The coding sequence for CKII beta comprises 648 nucleotides identical to the published CKII beta-cDNA sequence (Jakobi, R., Voss, H., and Pyerin, W. (1989) Eur. J. Biochem. 183, 227-233). The upstream promoter region of the CKII beta gene contains multiple potential gene regulatory sequence elements, noticeable DNA structures, and the characteristics of a housekeeping gene (more than one transcription initiation site, lack of a TATA-box, presence of a CpG island, occurrence of multiple GC boxes and of nonstandard positioned CCAAT boxes). The CKII beta gene promoter shares common features with that of mammalian protein kinases and is closely related to the regulatory subunit gene promoter of cAMP-dependent protein kinase.

[The value of symptoms and findings in urethral Chlamydia trachomatis infection]

The history and the results of clinical investigations in 74 patients with and 262 men without urethral Chlamydia (C.) trachomatis infection were evaluated: symptoms such as dysuria, discharge and/or burning/itching in the genital region were reported by 77% (n = 57) of the patients with an infection and 63.4% (n = 166) of the men without an infection. Upon clinical investigation, discharge was found in 55.4% (n = 41) of the chlamydia-positive patients and in 47.7% (n = 125) of the chlamydia-negative men. Only when yellow, whitish yellow and clear discharge were distinguished from one another was the difference between the two groups of patients (56.1% versus 12%) significant. Microscopic signs of urethritis, i.e. significant numbers of polymorphonuclear leukocytes (greater than 4 per high-power field and oil immersion) were detectable in the smears of 59.5% (n = 44) of the chlamydia-positive patients, in contrast to 15.6% (n = 41) in the smears of chlamydia-negative men. Overall, 67.6% (n = 50) of the patients with a C. trachomatis infection reported symptoms in the anamnesis combined with signs of urethritis upon clinical and microscopic investigation. There were 9.5% (n = 7) of the patients who either mentioned symptoms or showed clinical signs, and 13.5% (n = 10) who neither mentioned symptoms nor showed clinical signs. These results indicate that microbiological detection of the infectious agent is obligatory for diagnosis of urethral infection with C. trachomatis.

Measurement of plasma catecholamines by high-performance liquid chromatography with electrochemical detection in intensive care patients after dobutamine infusion

A procedure for the determination of plasma catecholamine concentrations in critical care patients after dobutamine infusion is presented. A modified chromatographic system is required with an additional washing procedure to achieve maximum sensitivity and stable chromatographic conditions. The influence of storage time on the catecholamine concentrations of plasma samples is reported in detail. A time-dependent decrease in catecholamine concentrations of up to 12 and 39% was found within two and ten months, respectively.

Immunogold labelling of human von Willebrand factor adsorbed to collagen

von Willebrand factor (vWF) mediates adhesion of platelets to the exposed subendothelium at sites of vascular injury. This function is expressed through binding of vWF to both collagen and receptors on the platelet membrane. We have developed a new method using immunogold staining and electron microscopy, permitting visualization of human vWF adsorbed to collagen fibrils. The electron micrographs revealed strings of gold beads reflecting the polymeric structure of vWF. Our data showed dramatic differences in the binding of vWF to collagens of different sources: high binding density was observed using a collagen preparation isolated from aortic tissue whereas colloidal gold was virtually absent from tendon collagen. Using the immunogold labelling method we demonstrated that high shear rate enhanced vWF binding to aortic collagen.

Elevated serum diiodotyrosine (DIT) in severe infections and sepsis: DIT, a possible new marker of leukocyte activity

Ether link cleavage (ELC) of T4 yielding diiodotyrosine (DIT) has recently been shown in vitro to be the major pathway of T4 metabolism in phagocytosing leukocytes. To evaluate this pathway in vivo and the possible clinical relevance of DIT measurements in diseases with increased leukocyte activity, radioimmunological studies on serum levels of DIT and other thyroid parameters were performed in 125 critically ill patients classified into 3 groups with bacterial infections according to the severity of infection and 1 group without infections. While the pattern of iodothyronine and TSH levels typical for severe nonthyroidal disorders, i.e. decreased total T3 and elevated rT3, normal or decreased total T4 and TSH, and normal free T4, was found in all four groups of intensive care patients studied, elevated serum DIT was observed only in those patients whose clinical course was complicated by severe bacterial infections. Serial measurements revealed a close temporal connection between the infection phase and increased DIT levels. Median values and 16th to 84th percentile ranges (in parentheses) of serum DIT (normal range, 0.02-0.55 nmol/L) were as follows: sepsis, 1.38 (0.32-5.14); severe nonsystemic infections such as peritonitis and abscesses, 3.84 (0.24-17.2); moderate infections such as pneumonia and tracheobronchitis, 0.44 (0.18-1.16); and critical illness without infections, 0.14 (0.08-0.30) nmol/L. These elevations of circulating DIT could neither be correlated with changes in renal function nor attributed to drug effects. The results of the present study do not allow any definitive conclusions to be made about the mechanisms underlying the phenomenon of increased serum DIT levels in infections. Apart from this open question, DIT appears to be a relatively specific serum parameter for the presence and course of severe bacterial inflammations. Its measurement could provide useful clinical information, particularly for monitoring the time course of deep-seated infections.

Monoclonal antibodies to gelonin: production and characterization

BALB/c mice were immunized with gelonin, a 30 kD glycoprotein (type 1 RIP) from the seeds of Gelonium multiflorum. By polyethylene glycol-induced fusion of isolated spleen cells with the myeloma cell line NS-1, three different hybridomas were obtained. Two of them were found to secrete antibodies of the IgG1 subclass, whereas the third cell line produced antibodies of the IgM type. The IgG1-secreting cell lines were adapted to serum-free medium conditions, and the antibodies were isolated from the culture supernatant. The isolated antibodies recognize independent epitopes on the gelonin molecule. The toxicity of gelonin in reticulocyte lysates was not affected when the protein was incubated with the antibodies. The IgG1s exhibit average affinity constants of about 10(9) M-1 and 10(10) M-1, respectively, as determined by a solid-phase EIA using the avidin-biotin system.

Sequence specific molecular recognition and binding by a GC recognizing Hoechst 33258 analogue to the decadeoxyribonucleotide d-[CATGGCCATG]2: structural and dynamic aspects deduced from high field 1H-NMR studies

The non-exchangeable and imino proton NMR resonances have been assigned of the 1:1 complex of an analogue 2 of Hoechst 33258 1 bound to the decadeoxyribonuycleotide d-[CATGGCCATG]2 by a combination of NOE difference, COSY and NOESYPH techniques. In contrast to Hoechst 33258 which recognizes 5'-AATT sequences exclusively, analogue 2 possesses structural features designed to permit the recognition of GC sites. The NOESY and 1D-NOE experiments place the drug in the minor groove and it is located on the 5'-CCAT sequence. The orientation of the drug in the groove is such as to place the N-methylpiperazine terminus at a GC site. Cross-correlation peaks in the NOESY experiment show that the DNA duplex retains its right-handed B form, similar to that in the free decamer. Specific NOEs locate the benzoxazole moiety on the 5'-CCAT and are consistent with the pyridine nitrogen forming a new hydrogen bond to G(4)-2NH2 at 5'-CCAT. The drug appears to undergo rotation around the C9-C10 bond, at a rate comparable with NMR time scale, even after binding. Variable temperature 1H-NMR studies established that the DNA is thermally stabilized as a result of the drug binding. The drug binding is a dynamic process involving exchange between the equivalent 5'-CCAT sites at approximately 60s-1 with delta G degree of 65 kJ mol-1 at 308K. The experimental evidence is in accord with a slide-swing mechanism for this process.

Molecular recognition and binding of a GC site-avoiding thiazole-lexitropsin to the decadeoxyribonucleotide d-[CGCAATTGCG]2: 1H-NMR evidence for thiazole intercalation

The structural and dynamic aspects of the interaction of the thiazole containing lexitropsin (1) with an oligodeoxyribonucleotide were studied by high field 1H-NMR spectroscopy. Complete assignment of the 1H-NMR resonances of lexitropsin 1 was accomplished by 2D-NMR techniques. The complexation-induced chemical shifts and NOE cross peaks in the NOESY map of the 1:1 complex of lexitropsin (1) and d-[CGCAATTGCG]2 reveal that the thiazole ring of the lexitropsin (1) intercalates between dA4.A5 bases and the rest of the ligand resides in the minor groove of the AT rich core of decamer, thus occupying the 5'-AATT sequence on the DNA. Intercalation of the thiazole moiety of the drug has been detected by the presence of intermolecular NOEs both in the major and the minor groove of the decamer helix. The absence of intranucleotide NOEs between base protons and H1'/H2' protons suggested local unwinding of the binding site on the DNA. From COSY and NOESY methods of 2D-NMR, it was established that the N-formyl (amino) terminus of the thiazole lexitropsin (1) is projecting into the major groove towards A5H8 while the amidinium terminus lies in the minor groove towards the T7G8 base pairs of the opposite strand. The expected intranucleotide NOEs confirmed that the decadeoxyribonucleotide in the 1:1 complex exists in a right handed B-conformation. The presence of exchange signals along the binding site 5'-AATT indicated an exchange of the bound drug process wherein the rate of exchange between the two equivalent sites was estimated to be congruent to 130 s-1 at 30 degrees C and with delta G degrees of 62.4 kJ mol-1. Force field and Pi calculations permitted a rationalization of the experimentally observed binding mode in terms of preferred conformation of the ligand and repeat length in lexitropsins compared with the DNA receptor.

[Tumoral calcinosis]

Tumoral calcinosis is a distinct entity, which is rarely seen in Europe and North America but much more common in black Africans. Typical symptoms are calcified nodules, which grow while remaining asymptomatic and are found in the tissues adjacent to the large joints of the body. Histologically there is collagen necrobiosis initially, which results in aggregates of densely calcified material. The aetiology is unknown, but the condition is probably a form of dystrophic calcification caused by mechanical injury. A patient with tumoral calcinosis is presented, and the clinical and histological findings are described.

Automated DNA sequencing of the human HPRT locus

The complete sequence of 57 kb of the human HPRT locus has been determined using automated fluorescent DNA sequencing. The strategy employed increasingly directed sequencing methods: A randomly generated M13 library was sequenced to generate contiguous overlapping sets of sequences (contigs). M13 clones at the ends of these contigs were further sequenced using M13 (universal and reverse) and custom oligonucleotide primers to order the contigs and to complete the sequencing project. The human HPRT sequence includes 1676 bp 5' and 15,238 bp 3' to exons 1 and 9, respectively. The sequence contains 49 representatives of the Alu repeat, along with several other types of repetitive sequences. The Alu sequences exhibit a biased orientation, with those sequences in the first half of the locus oriented in the minus direction relative to transcription of the gene (3'----5' = 77%, P less than 0.005) and those sequences in the latter half of the locus oriented randomly (5'----3' = 67%, P less than 0.5). The development and performance of the sequencing strategy and the features of the human HPRT gene are presented.