[Mycotic aneurysms--A retrospective analysis]

12 patients (10 males and 2 females, average age 53 years) were operated upon in our hospital between 1994 and 1999 for mycotic aneurysms. The aneurysms were located in 7 patients in the aorto-iliac segment, 5 patients were treated for peripheral or visceral aneurysms. Two of these patients suffered from multiple aneurysms. When peripheral arteries were affected, a pulsatile tumour was felt. Most of these tumours developed in a relatively short period of time and sometimes a perivascular inflammation occurred. This was not the case when central arteries were attacked. A septic process or an infection, for example salmonella-enteritis, often preceded shortly the development of a mycotic aneurysm. In the case of an aneurysm of the aorto-iliac section we consider an in situ reconstruction with alloplastic material in combination with a perivascular debridement, lavage and omentum majus plastic as the treatment of choice. In peripheral arteries reconstruction should be performed with autologous vessels. Depending on the local findings, a perivascular debridement should also be performed in these cases. The reconstruction always should be combined with a calculated antibiotic therapy. Two of our patients died perioperatively. During follow up, 8 patients showed patent reconstructions and no signs of infection. The urgency of surgery depends on the level of inflammation and the existence of any secondary complications.

Demonstration of heterogeneous genotypes of Taylorella equigenitalis isolated from horses in six European countries by pulsed-field gel electrophoresis

Forty-six isolates of Taylorella equigenitalis were analysed by pulsed-field gel electrophoresis (PFGE) after separate digestion of the genomic DNA with ApaI and with NotI. The isolates had been obtained from horses in six European countries and were classified into 18 genotypes. In Belgium, 2 genotypes were detected in 2 isolates, in England 9 among 15, in Finland 2 in 2, in France 2 among 10, in Sweden 3 among 5, and in Switzerland 3 among 12. Two English isolates and 4 French isolates gave identical PFGE profiles to those of Kentucky 188 from the United States. A common genotype was found in 5 isolates from Belgium and England and also in 10 isolates from France and Switzerland. The analysis of genomic DNA from 12 isolates of T equigenitalis obtained from male horses in France, Sweden and Switzerland gave no evidence of a sex-related difference in the genomic DNA. Genomic DNA from 11 streptomycin (STM)-susceptible isolates obtained in Sweden and Switzerland were classified into four genotypes by PFGE. Each of the six genotypes determined among the 17 isolates from these two countries had single phenotypes for resistance or susceptibility to STM.

A screen for genes required for meiosis and spore formation based on whole-genome expression

BACKGROUND

Meiosis is the process by which gametes are generated with half the ploidy of somatic cells. This reduction is achieved by three major differences in chromosome behavior during meiosis as compared to mitosis: the production of chiasmata by recombination, the protection of centromere-proximal sister chromatid cohesion, and the monoorientation of sister kinetochores during meiosis I. Mistakes in any of these processes lead to chromosome missegregation.

RESULTS

To identify genes involved in meiotic chromosome behavior in Saccharomyces cerevisiae, we deleted 301 open reading frames (ORFs) which are preferentially expressed in meiotic cells according to microarray gene expression data. To facilitate the detection of chromosome missegregation mutants, chromosome V of the parental strain was marked by GFP. Thirty-three ORFs were required for the formation of wild-type asci, eight of which were needed for proper chromosome segregation. One of these (MAM1) is essential for the monoorientation of sister kinetochores during meiosis I. Two genes (MND1 and MND2) are implicated in the recombination process and another two (SMA1 and SMA2) in prospore membrane formation.

CONCLUSIONS

Reverse genetics using gene expression data is an effective method for identifying new genes involved in specific cellular processes.

Measurement of the recoil polarization in the p(e-->, e'p-->)pi(0) reaction at the Delta(1232) resonance

The recoil proton polarization has been measured in the p(e-->,e'p-->)pi(0) reaction in parallel kinematics around W = 1232 MeV, Q2 = 0.121 (GeV/c)2, and epsilon = 0.718 using the polarized cw electron beam of the Mainz Microtron. All three proton polarization components, Px/P(e) = (-11.4+/-1.3+/-1.4)%, P(y) = (-43.1+/-1.3+/-2.2)%, and P(z)/P(e) = (56.2+/-1.5+/-2.6)%, could be measured simultaneously. The Coulomb quadrupole to magnetic dipole ratio, CMR = (-6.4+/-0.7(stat)+/-0.8(syst))%, was determined from Px in the framework of the Mainz Unitary Isobar Model. The consistency among the reduced polarizations and the extraction of the ratio of longitudinal-to-transverse response is discussed.

Building a Web-based drug ordering system for hospitals: from requirements engineering to prototyping

Web-based drug ordering allows a growing number of hospitals without pharmacy to communicate seamlessly with their external pharmacy. Business process analysis and object oriented modelling performed together with the users at a pilot hospital resulted in a comprehensive picture of the user and business requirements for electronic drug ordering. The user requirements were further validated with the help of a software prototype. In order to capture the needs of a large number of users CAP10, a new method making use of pre-built models, is proposed. Solutions for coping with the technical requirements (interfacing the business software at the pharmacy) and with the legal requirements (signing the orders) are presented.

B-type cyclins CLB5 and CLB6 control the initiation of recombination and synaptonemal complex formation in yeast meiosis

BACKGROUND

The life cycle of most eukaryotic organisms includes a meiotic phase, in which diploid parental cells produce haploid gametes. During meiosis a single round of DNA replication is followed by two rounds of chromosome segregation. In the first, or reductional, division (meiosis I), which is unique to meiotic cells, homologous chromosomes segregate from one another, whereas in the second, or equational, division (Meiosis II) sister centromeres disjoin. Meiotic DNA replication precedes the initiation of recombination by programmed Spo11-dependent DNA double-strand breaks. Recent reports that meiosis-specific cohesion is established during meiotic S phase and that the length of S phase is modified by recombination factors (Spo11 and Rec8) raise the possibility that replication plays a fundamental role in the recombination process.

RESULTS

To address how replication influences the initiation of recombination, we have used mutations in the B-type cyclin genes CLB5 and CLB6, which specifically prevent premeiotic replication in the yeast Saccharomyces cerevisiae. We find that clb5 and clb5 clb6 but not clb6 mutants are defective in DSB induction and prior associated changes in chromatin accessibility, heteroallelic recombination, and SC formation. The severity of these phenotypes in each mutant reflects the extent of replication impairment.

CONCLUSIONS

This assemblage of phenotypes reveals roles for CLB5 and CLB6 not only in DNA replication but also in other key events of meiotic prophase. Links between the function of CLB5 and CLB6 in activating meiotic DNA replication and their effects on subsequent events are discussed.

HO endonuclease-induced recombination in yeast meiosis resembles Spo11-induced events

In meiosis, gene conversions are accompanied by higher levels of crossing over than in mitotic cells. To determine whether the special properties of meiotic recombination can be attributed to the way in which Spo11p creates double-strand breaks (DSBs) at special hot spots in Saccharomyces cerevisiae, we expressed the site-specific HO endonuclease in meiotic cells. We could therefore compare HO-induced recombination in a well-defined region both in mitosis and meiosis, as well as compare Spo11p- and HO-induced meiotic events. HO-induced gene conversions in meiosis were accompanied by crossovers at the same high level (52%) as Spo11p-induced events. Moreover, HO-induced crossovers were reduced 3-fold by a msh4Delta mutation that similarly affects Spo11p-promoted events. In a spo11Delta diploid, where the only DSB is made by HO, crossing over was significantly higher (27%) than in mitotic cells (</=7%). This single meiotic DSB failed to induce the formation of a synaptonemal complex. We also show that HO-induced gene conversion tract lengths are shorter in meiotic than in mitotic cells. We conclude that a hallmark of meiotic recombination, the production of crossovers, is independent of the nature of Spo11p-generated DSBs at special hotspots, but some functions of Spo11p are required in trans to achieve maximum crossing over.

Identification of high affinity Tbf1p-binding sites within the budding yeast genome

The yeast TBF1 gene is essential for mitotic growth and encodes a protein that binds the human telomere repeats in vitro, although its cellular function is unknown. The sequence of the DNA-binding domain of Tbf1p is more closely related to that of the human telomeric proteins TRF1 and TRF2 than to any yeast protein sequence, yet the functional homologue of TRF1 and TRF2 is thought to be Rap1p. In this study we show that the Tbf1p DNA-binding domain can target the Gal4 transactivation domain to a (TTAGGG)(n) sequence inserted in the yeast genome, supporting the model that Tbf1p binds this sub-telomeric repeat motif in vivo. Immunofluorescence of Tbf1p shows a spotty pattern throughout the interphase nucleus and along synapsed chromosomes in meiosis, suggesting that Tbf1p binds internal chromosomal sites in addition to sub-telomeric regions. PCR-assisted binding site selection was used to define a consensus for high affinity Tbf1p-binding sites. Compilation of 50 selected oligonucleotides identified the consensus TAGGGTTGG. Five potential Tbf1p-binding sites resulting from a search of the total yeast genome were tested directly in gel shift assays and shown to bind Tbf1p efficiently in vitro, thus confirming this as a valid consensus for Tbf1p recognition.

Helicity dependence of gammap --> Npi below 450 MeV and contribution to the Gerasimov-Drell-Hearn sum rule

The helicity dependence of the single pion photoproduction on the proton has been measured in the energy range from 200 to 450 MeV for the first time. The experiment, performed at the Mainz microtron MAMI, used a 4pi-detector system, a circularly polarized, tagged photon beam, and a frozen-spin target. The data obtained provide new information for multipole analyses of pion photoproduction and determine the main contributions to the Gerasimov-Drell-Hearn sum rule and the forward spin polarizability gamma(0).

Electron paramagnetic resonance for everybody--MICROspec-X--a new class of electron paramagnetic resonance spectrometer

The electron paramagnetic resonance spectroscopy is the only method for detecting free radicals. Free radicals have an increased importance in our daily life. A small transportable EPR spectrometer is presented for the popularisation of the EPR method. The technical construction and some applications are illustrated which show the usability of the spectrometer.

Quantitative karyotyping and dual-color FISH mapping of 5S and 18S-25S rDNA probes in the cultivated Phaseolus species (Leguminosae)

Double-color fluorescence in situ hybridization (FISH) followed by DAPI counterstaining allowed the chromosomal assignment of 5S and 18S-25S rRNA genes in the four cultivated Phaseolus Species; P. vulgaris, P. coccineus, P. acutifolius, and P. lunatus (all: 2n = 2x = 22). The rRNA gene loci display variation between species as reflected in differences of signal size and (or) number. From one to three pairs of 5S sites and one to seven pairs of 18S-25S sites were found in the diploid complements of the four taxa studied. Intraspecific variation was studied in P. vulgaris, and it is shown that the number of 18S-25S rDNA sites differs between cultivars. Cytogenetic mapping was complemented by karyotype analyses. Each of the four cultivated Phaseolus species exhibits a characteristic heterochromatin endowment, with P. acutifolius var. latifolius having the highest amount of C-band material. Quantitative karyotyping in combination with cytogenetic mapping allowed the identification of homeologous chromosomes in the different species.

Estimation of Neospora caninum seroprevalence in dairy cattle from Normandy, France

An epidemiological study was conducted in Orne (France) on randomly selected dairy herds (42 herds including 1,924 cows and heifers, which were at least 15 months old). The aim was primarily to estimate the seroprevalence of Neospora caninum infection from two blood samples per cow, using an enzyme-linked immunosorbent assay (ELISA) for N. caninum (one positive result indicating infection). The second aim was to test the association between some individual and herd factors and N. caninum seropositivity with a logistic model including a random term effect. The prevalence was estimated at 5.6% (107 seropositive animals). At least 27 of the 42 herds had one seropositive cow or heifer. The intra-herd seroprevalence varied from 1.1 to 8% for 18 positive herds (66.7%). Dogs were present in 36 farms and 104 of the 107 seropositive animals were exposed to them. The factors associated with individual seropositivity were the presence of cats (OR = 0.17; P < 0.001), dogs (OR = 4.35; P = 0.02), rabbits and/or ducks (OR = 2.10; P = 0.04), long calving periods (12 months) (OR = 0.44; P = 0.007), tethered housing (OR = 2.50; P = 0.01), somatic cell counts (200-400 x 10(3) cells/mL) (OR = 0.24; P < 0.001) and pond water supply (OR = 2.43; P = 0.04). In conclusion, the animal and intra-herd seroprevalences were low in dairy cows from Normandy, France.

A central role for cohesins in sister chromatid cohesion, formation of axial elements, and recombination during yeast meiosis

A multisubunit complex, called cohesin, containing Smc1p, Smc3p, Scc1p, and Scc3p, is required for sister chromatid cohesion in mitotic cells. We show here that Smc3p and a meiotic version of Scc1p called Rec8p are required for cohesion between sister chromatids, for formation of axial elements, for reciprocal recombination, and for preventing hyperresection of double-strand breaks during meiosis. Both Rec8p and Smc3p colocalize with chromosome cores independently of synapsis during prophase I and largely disappear from chromosome arms after pachytene but persist in the neighborhood of centromeres until the onset of anaphase II. The eukaryotic cell's cohesion apparatus is required both for the repair of recombinogenic lesions and for chromosome segregation and therefore appears to lie at the heart of the meiotic process.

YDL142c encodes cardiolipin synthase (Cls1p) and is non-essential for aerobic growth of Saccharomyces cerevisiae

The unassigned open reading frame YDL142c was identified to code for cardiolipin synthase, Cls1p. A cls1 deletion strain is viable on glucose, galactose, ethanol, glycerol and lactate containing media, although the growth rate on non-fermentable carbon sources is decreased. Mitochondria of the cls1 mutant are devoid of cardiolipin but accumulate the cardiolipin precursor phosphatidylglycerol when grown on non-fermentable carbon sources. Specific activity of phosphatidylglycerolphosphate synthase in cls1 is reduced to 30-75% of the wild-type level. Amounts of mitochondrial cytochromes and activity of cytochrome c oxidase, however, are not affected in the cls1 deletion strain. Collectively, these data indicate that cardiolipin is not essential for aerobic growth of Saccharomyces cerevisiae.

mre11S--a yeast mutation that blocks double-strand-break processing and permits nonhomologous synapsis in meiosis

During meiotic prophase the repair of self-inflicted DNA double-strand break (DSB) damage leads to meiotic recombination in yeast. We employed a genetic screen to specifically characterize cellular functions that become essential after this DSB formation. As a result a new allele of MRE11, termed mre11S (for Separation of functions) was isolated that allows initiation but not processing and repair of meiotic DSBs similar to the well-characterized rad50S allele. In contrast, the mre11-1 allele blocks initiation of meiotic DSBs as reported previously by others. The mre11S allele, which is mutated in the 5' part of the gene, can partially complement mre11 alleles disrupted close to the 3' end that cannot initiate DSBs when homozygous. This suggests homodimerization of the Mre11 protein and the presence of separate domains for DSB initiation and 5' resection. The fact that two genes, RAD50 and MRE11, required for DSB processing are also essential for DSB initiation dictates a model in which a bifunctional initiation/repair complex is required to initiate meiotic recombination. A subset of mre11S nuclei was shown to perform extensive but partially nonhomologous synapsis. We propose that the unprocessed DSBs present in mre11S allow for synapsis, but that homologous synapsis is only ensured at a later stage of recombination.

[Transesophageal ultrasound for staging lung tumors]

PURPOSE

The usefulness of transesophageal sonography in staging lung cancer was examined.

METHOD

Transoesophageal sonography was performed in 15 patients as a staging examination using either biplane or multiplane technique. The results were compared with other radiological techniques such as computed tomography and, if performed, with the findings in the operation.

RESULTS

The neoplastic mass was correctly identified in 12 of the 15 patients. Transoesophageal sonography is a very useful examination, more so than computed tomography, for identification of a tumour infiltration into great vessels or cardiovascular structures. In 8 cases we found paraaortal tumour masses and in 4 cases infiltration of the pulmonary artery. In 2 cases we could show an infiltration of heart chambers. The sensitivity for detecting lymph nodes was 80% in the lower mediastinum and, because of method limitations, only 33% in the upper mediastinum.

CONCLUSION

Transoesophageal sonography is an excellent addition to the already well established staging methods in staging lung cancer. This examination clearly has advantages over the conventional methods (CT scan) for the diagnosis of vessel involvement, extrinsic compression of the heart, and for the recognition of lymph node metastases. The limitation of this examination is the restriction to the paraoesophageal area and reduced effectiveness in areas filled with air and other nonconductive structures.

Isolation of COM1, a new gene required to complete meiotic double-strand break-induced recombination in Saccharomyces cerevisiae

We have designed a screen to isolate mutants defective during a specific part of meiotic prophase I of the yeast Saccharomyces cerevisiae. Genes required for the repair of meiotic double-strand breaks or for the separation of recombined chromosomes are targets of this mutant hunt. The specificity is achieved by selecting for mutants that produce viable spores when recombination and reductional segregation are prevented by mutations in SPO11 and SPO13 genes, but fail to yield viable spores during a normal Rec+ meiosis. We have identified and characterized a mutation com1-1, which blocks processing of meiotic double-strand breaks and which interferes with synaptonemal complex formation, homologous pairing and, as a consequence, spore viability after induction of meiotic recombination. The COM1/SAE2 gene was cloned by complementation, and the deletion mutant has a phenotype similar to com1-1, com1/sae2 mutants closely resemble the phenotype of rad50S, as assayed by phase-contrast microscopy for spore formation, physical and genetic analysis of recombination, fluorescence in situ hybridization to quantify homologous pairing and immunofluorescence and electron microscopy to determine the capability to synapse axial elements.

Elevated ambulatory blood pressure in microalbuminuric IDDM patients is inversely associated with renal plasma flow. A compensatory mechanism?

OBJECTIVE

To evaluate the relationship between renal function, ambulatory blood pressure (AMBP), and glycemic control in microalbuminuric IDDM patients compared with normoalbuminuric patients.

RESEARCH DESIGN AND METHODS

Nineteen male patients (age 33 +/- 6 years) with slight microalbuminuria (UAE 20-70 micrograms/min) were compared with 19 normoalbuminuric (UAE < 15 micrograms/min) age-matched (33 +/- 6 years) male patients. Through constant infusion technique, 125I-iothalamate marked the glomerular filtration rate (GFR), and 131I-hippuran marked effective renal plasma flow (RPF). AMBP was measured by oscillometric technique (Spacelabs 90202).

RESULTS

The microalbuminuric group had higher daytime systolic AMBP (132 +/- 11 vs. 125 +/- 7 mmHg, P < 0.05) and a poorer glycemic control (HbA1c 9.5 +/- 1.5 vs. 8.2 +/- 1.3%, P < 0.01). GFR (135 +/- 22 and 135 +/- 17 ml/min) and RPF (598 +/- 112 and 542 +/- 98 ml/min) were similar in the two groups. In the microalbuminuric group, daytime systolic AMBP was inversely correlated to both RPF (r = -0.77, P < 0.005) and GFR (r = -0.53, P = 0.02). HbA1c and GFR correlated positively in the microalbuminuric group (r = 0.47, P < 0.04). In contrast, the normoalbuminuric patients exhibited no such associations.

CONCLUSIONS

IDDM patients with moderate microalbuminuria have elevated AMBP and a strong negative association between AMBP and RPF. This leaves several possibilities of interpretation. Primary blood pressure increase (of unknown origin) may induce morphological changes leading to reduction in renal function. Alternatively, blood pressure increase early in the course of incipient nephropathy may represent a compensatory mechanism, initially aiming at preservation of renal function, but later becoming maladaptive.

Production and characterization of monoclonal antibodies against Taylorella equigenitalis

Monoclonal antibodies were produced against Taylorella equigenitalis using two reference strains. Out of the 79 hybridoma clones shown to express antibodies to T equigenitalis by indirect immunofluorescence assay, 16 were selected for monoclonal antibody production and characterization. These clones recognized different field strains of T equigenitalis isolated in France. They showed no cross-reaction with bacterial strains with previously reported antigenic cross-reactivity, nor did they react with other bacteria commonly found in genital flora. The epitopes recognized by eight of the monoclonal antibodies were situated in proteins of 150, 120, 52.7 and 22 kDa. These epitopes were resistant to the extraction denaturing conditions. These monoclonal antibodies could be used as reagents for specific detection of T equigenitalis.

Chagas' disease after bone marrow transplantation

Chagas' disease is caused by Trypanosoma cruzi. It is endemic in Latin America where 16 to 18 million people are infected. Immunocompromised patients such as BMT recipients are at risk of Chagas' disease either due to reactivation or transfusion. We report a case of acute Chagas' disease in the setting of BMT.

Morphology of a human-derived YAC in yeast meiosis

In meiosis of human males DNA is packaged along pachytene chromosomes about 20 times more compactly than in meiosis of yeast. Nevertheless, a human-derived yeast artificial chromosome (YAC) shows the same degree of compaction of DNA as endogenous chromosomes in meiotic prophase nuclei of yeast. This suggests that in yeast meiosis, human and yeast DNA adopt a similar organization of chromatin along the pachytene chromosome cores. Therefore meiotic chromatin organization does not seem to be an inherent chromosomal property but is governed by the host-specific cellular environment. We suggest that there is a correlation between the less dense DNA packaging and the increased rate of recombination that has been reported for human-derived YACs as compared with human DNA in its natural environment.