Soil mutagens are airborne mutagens: variation of mutagenic activities induced in Salmonella typhimurium TA 98 and TA 100 by organic extracts of agricultural and forest soils in dependence on location and season

As our hypothesis was that soil mutagens are airborne mutagens, possibly modified by soil microorganisms, we checked solvent extracts from agricultural and forest soils collected during late summer in the environment of Mainz, a region highly charged by anthropogenic air pollution, or near Bayreuth, a rural low charged region of Germany, or in a remote region of western Corsica without anthropogenic air pollution for the presence of mutagenicity in Salmonella typhimurium. Levels of mutagenic activities were quantified by calculation of revertants/g from the initial slope of dose-response curves applying tester strains S. typhimurium TA 98 and TA 100 in the absence and presence of an activation system from rat liver (S9). Three soils from Corsica did not induce mutagenicity under any test condition. However, most soils from Germany exhibited mutagenic activities, though preferentially in strain TA 98, but no statistically significant differences could be detected between 27 soils from the Mainz and nine soils from the Bayreuth regions. On the other hand, no correlation could be detected between the levels of mutagenic activities at any test condition and agricultural practice - rye growing, viniculture, fruit growing, meadow, and fallow - texture of soils - % composition of clay, slit, and sand - or the contents of organic matter. The only significant difference of mutagenicity was, however, found with S. typhimurium TA 98-S9 between forest soils of pH approximately 4.0 as compared with agricultural soils of pH approximately 7.0. The presence of antimutagens in soil as demonstrated by the course of dose-response curves of the three soils from Corsica may be another possible confounder. Calculation of mean values of mutagenic activities for all soils from Germany gave the following results: S. typhimurium TA 98: 69.7+/-153.2 (-S9); 63.0+/-176.3 (+S9); S. typhimurium TA 100:-144.7+/-399.4 (-S9); 43.3+/-172.0 (+S9) revertants/g of dry soil. In another series of experiments, soil mutagenicity in 10 rye fields near Mainz was monitored for 1 year. It became evident that low levels of mutagenic activities in late summer increased during autumn, reached a peak in late winter, and subsequently, decreased during spring and summer. These results agree with the hypothesis of an airborne origin of soil mutagens, deposition, and an adjacent transformation to non-mutagenic compounds by soil microorganisms.

Role of the substantia nigra pars reticulata in sensorimotor gating, measured by prepulse inhibition of startle in rats

The substantia nigra pars reticulata (SNR) is one of the major output nuclei of the basal ganglia. It connects the dorsal and ventral striatum with the thalamus, superior colliculus and pontomedullary brainstem. The SNR is therefore in a strategic position to regulate sensorimotor behavior. We here assessed the effects of SNR lesions on prepulse inhibition (PPI) of the acoustic startle response (ASR), stereotypy and locomotion in drug-free rats, as well as after systemic administration of the dopamine agonist DL-amphetamine (2 mg/kg), and the NMDA receptor antagonists dizocilpine (0.16 mg/kg) and CGP 40116 (2 mg/kg). SNR lesions reduced PPI, enhanced spontaneous sniffing and potentiated the locomotor stimulation by dizocilpine and CGP 40116. PPI was impaired by dizocilpine and CGP 40116 in controls. The ASR was enhanced in controls by dizocilpine and amphetamine. SNR lesions prevented the enhancement of the ASR by amphetamine. A second experiment tested the hypothesis that the SNR mediates PPI via a GABAergic inhibition of the startle pathway. Infusion of the GABA(B) antagonist phaclofen but not the GABA(A) antagonist picrotoxin into the caudal pontine reticular nucleus reduced PPI. Hence, lesion of the SNR reduces sensorimotor gating possibly by elimination of a nigroreticular GABAergic projection interacting with GABA(B) receptors. Moreover, destruction of the SNR enhances the motor stimulatory effects of amphetamine and of the NMDA antagonists dizocilpine and CGP 40116. We conclude that the SNR exerts a tonic GABAergic inhibition on sensorimotor behavior that is regulated by the dorsal and the ventral striatum.

An assessment of eddy current sensitivity and correction in single-shot diffusion-weighted imaging

Artefacts caused by eddy currents are a major problem in diffusion weighted imaging. This is particularly acute in experiments in which a number of images with differing degrees of diffusion weighting and/or differently oriented diffusion-weighting gradients need to be combined. The echo-planar imaging sequence is particularly sensitive to the effects of residual eddy currents, especially due to the low bandwidth in the phase-encoding direction. Two published schemes are investigated regarding the effectiveness of eddy current correction. That of Jezzard et al (1998 Magn. Reson. Med. 39 801-12) requires the acquisition of additional experimental data in order to perform a post-acquisition correction, whereas that of Wider et al (1994 J. Magn. Reson. A 108 255-8) attempts to reduce the eddy currents directly. It is found that the latter experiment gives a somewhat superior performance and a combination of the two approaches results in an almost complete elimination of artefact. An alternative single-shot imaging experiment to echo-planar imaging is given by sequences based on fast spin-echo methods, which should be insensitive to the effects of constant eddy currents. It is shown that the intrinsic eddy-current-related artefact level in such experiments is indeed low, residual artefacts being attributed to eddy current decay during the echo train. In situations of poor main magnetic field homogeneity or large eddy currents such sequences may be gainfully used instead of echo-planar imaging.

Vagus-sparing gastric fundectomy in the rat: development of osteopenia, relationship to urinary phosphate and net acid excretion, serum gastrin and vitamin D

In man and experimental animals, partial and total gastrectomy and gastric vagotomies disturb extracellular mineral homeostasis, osteopenia being among the late outcomes. The sequence of events is complex and insufficiently understood. We report on the long-term effects of gastric fundectomy (FX; FX-1, n=11; sham-operated controls, n=14) sparing gastric vagal fibers at the lesser curvature in the rat, a procedure eliminating gastric acid production but preserving gastric reservoir function. After FX-1 there was a marked increase of gastrinemia [FX-1: 590 (SE 95); controls: 82 (5) pg-equiv/ml; P<0.001], serum 1,25-dihydroxyvitamin D [FX-1: 188 (17); controls: 86 (6) pg/ml; P<0.001], phosphaturia [FX-1: 32 (2); controls 23 (2) micromol/h; P<0.001] due to increased fractional phosphate clearance, elevated urinary net acid [FX-1: 21 (2); controls: 16 (1) micromol/h; P=0.03], and low urinary pH. The urinary excretion of hydroxyproline was increased [FX-1: 137 (15); controls: 99 (8) micromol/h; P=0.01], and crosslinks were also high. These changes were associated with a significant decrease of bone ash calcium, magnesium, and phosphorus. Bone histomorphometry revealed signs of high bone turnover. No signs of hyperparathyroidism were detectable. Acute stimulation of serum gastrin by gastric acid abolishing omeprazole failed to provoke extra-osseous changes, as seen in the long-term after fundectomy. It was concluded that the described type of fundectomy disturbs gastrinemia, acid-base and phosphorus metabolism, thereby initiating osteopenia. This animal model may be suitable for research into post-gastrectomy bone disease.

Gene characterization of sciellin (SCEL) and protein localization in vertebrate epithelia displaying barrier properties

Sciellin is a precursor of the cornified envelope of mammalian stratified epithelia characterized by a central core of nonidentical repeats. We characterized the genomic structure of human sciellin and showed that each homologous repeat was encoded by one exon. We also characterized mouse sciellin and showed that mouse sciellin and human sciellin (HGMW-approved symbol SCEL) share a similar gene organization and protein expression pattern. This one exon/one repeat organization is unique among other cornified envelope precursors characterized by homologous repeats. We identified an alternatively spliced isoform of human sciellin, absent in mouse, characterized by an additional repeat at the beginning of the core domain. During embryonic development, the accumulation of sciellin transcript and the accumulation of sciellin protein in the epidermis correlated with the activation of markers of terminal differentiation in epidermis. Mouse sciellin was also identified in simple epithelia with barrier properties, lending further support to its importance in epithelial function.

Impairment in a discrimination reversal task after D1 receptor blockade in the pigeon "prefrontal cortex"

Dopamine (DA) is known to modulate cognitive functions of the prefrontal cortex (PFC) of mammals, especially via D1 receptor mechanisms. Like the PFC, the neostriatum caudolaterale (NCL) of birds is characterized by dopaminergic input, and NLC and PFC lesions cause similar deficits. The significance of DA in a color discrimination reversal was assessed by evaluating the effects of bilateral infusions of the D1 receptor antagonist SCH 23390 into the NCL of pigeons (Columba livia). Reversal deficits were qualitatively similar to those in mammals. At a low dose, perseveration occurred predominantly to the incorrect stimulus. Higher doses caused additional spatial perseveration. The data demonstrate, for the first time, that D1 receptor mechanisms in the NCL of pigeons contribute substantially to its function in cognitive processes. Thus, the avian NCL and mammalian PFC could represent functionally equivalent neural networks under control of the DA system.

Interaction of yeast kinetochore proteins with centromere-protein/transcription factor Cbf1

The centromere-kinetochore complex of Saccharomyces cerevisiae is a specialized chromosomal substructure that mediates attachment of duplicated chromosomes to the mitotic spindle by a regulated network of protein-DNA and protein-protein interactions. We have used in vitro assays to analyze putative molecular interactions between components of the yeast centromerekinetochore complex. Glutathione S-transferase pull-down experiments showed the direct interaction of in vitro translated p110, p64, and p58 of the essential CBF3 kinetochore protein complex with Cbf1p, a basic region helix-loop-helix zipper protein (bHLHzip) that specifically binds to the CDEI region on the centromere DNA. Furthermore, recombinant p64 and p23 each stimulated the in vitro DNA binding activity of Cbf1p. The N-terminal 70 amino acids of p23 were sufficient to mediate this effect. P64 could also promote the multimerization activity of Cbf1p in the presence of centromere DNA in vitro. These results show the direct physical interaction of Cbf1p and CBF3 subunits and provide evidence that CBF3 components can promote the binding of Cbf1p to its binding site in the yeast kinetochore. A functional comparison of the centromere binding proteins with transcription factors binding at MET16 promoters reveals the strong analogy between centromeres and the MET16 promoter.

Budesonide in the treatment of Crohn's disease: a meta-analysis

AIM

To perform a meta-analysis to assess the effectiveness and safety of oral budesonide for inducing remission in active Crohn's disease and for preventing relapse in Crohn's disease with medically- or surgically-induced remission.

METHODS

All randomized, double-blind controlled trials involving oral budesonide therapy in Crohn's disease were retrieved from a Medline search, reviews articles or their bibliographies. Of 83 articles retrieved, 12 met the inclusion criteria. Data extraction was performed by three independent observers and scoring disagreements were resolved by consensus.

RESULTS

Six trials tested budesonide in active disease and six in quiescent disease. Budesonide was less effective than conventional corticosteroids for inducing remission of active Crohn's disease (pooled rate difference, RD -8.5%; 95% CI: -16.4 to -0.7%; P=0.02), but corticosteroid-related adverse events were reduced (RD -22.4%; 95% CI: -32 to -12.8%; P < 0.001). In quiescent Crohn's disease, budesonide was as effective as placebo for preventing relapse in medically induced remission (RD -0.8%; 95% CI: -9.9 to 8.3%; P=0.42) and endoscopic recurrence in surgically induced remission (RD -3.5%; 95% CI: -16.9 to 9.8%; P=0.30). In the long term treatment, budesonide had an occurrence rate of corticosteroid-related adverse effects similar to placebo (RD 5.3%; 95% CI: -3.9 to 14.5%; P=0.30).

CONCLUSIONS

Budesonide is significantly less effective than conventional corticosteroids for inducing remission in active Crohn's disease, but the risk of corticosteroid-related adverse effects is significantly reduced. Budesonide is not effective in preventing relapse of Crohn's disease after medically- or surgically-induced remission.

Blockade of NMDA receptors in the amygdala prevents latent inhibition of fear-conditioning

The association between a conditioned stimulus (CS) and an unconditioned stimulus (US) in fear-conditioning depends on N-methyl-D-aspartate (NMDA) receptors in the basolateral amygdala complex (BLA). Latent inhibition (LI) is the retardation in learning due to nonreinforced presentation of the prospective CS before conditioning. Disruption of LI in rats is an animal model of schizophrenia, reflecting the deficits of schizophrenic patients in neglecting irrelevant information. We investigated whether the BLA is involved in LI of fear-potentiated startle. Infusions of the NMDA receptor antagonist D,L-2-amino-5-phosphonopentanoic acid (AP-5; 12.5 nmoles) into the BLA before preexposure of rats to the neutral stimulus prevent LI of fear-conditioning. We also demonstrated by the same method that a complex of thalamic nuclei, comprising the medial part of the medial geniculate nucleus, the posterior intralaminar nucleus, and the suprageniculate nucleus, is involved in fear-conditioning, but not in LI. This suggests that the presentation of an innocuous stimulus during preexposure leads to an NMDA receptor-dependent change of neurotransmission in the BLA, but not in the thalamus. Our data show that the BLA but not the thalamus regulates in LI of fear-potentiated startle. Furthermore, it supports the hypothesis that the inability of schizophrenic patients to ignore irrelevant stimuli may be caused by hypofunction of the glutamatergic transmission in the brain and suggests an involvement of the amygdala in the neuropathology of schizophrenia.

A novel member of the netrin family, beta-netrin, shares homology with the beta chain of laminin: identification, expression, and functional characterization

The netrins are a family of laminin-related molecules. Here, we characterize a new member of the family, beta-netrin. beta-Netrin is homologous to the NH(2) terminus of laminin chain short arms; it contains a laminin-like domain VI and 3.5 laminin EGF repeats and a netrin C domain. Unlike other netrins, this new netrin is more related to the laminin beta chains, thus, its name beta-netrin. An initial analysis of the tissue distribution revealed that kidney, heart, ovary, retina, and the olfactory bulb were tissues of high expression. We have expressed the molecule in a eukaryotic cell expression system and made antibodies to the expressed product. Both in situ hybridization and immunohistochemistry were used to describe the cellular source of beta-netrin and where beta-netrin is deposited. beta-Netrin is a basement membrane component; it is present in the basement membranes of the vasculature, kidney, and ovaries. In addition, beta-netrin is expressed in a limited set of fiber tracts within the brain, including the lateral olfactory tract and the vomeronasal nerve. Functional studies were performed and show that beta-netrin promotes neurite elongation from olfactory bulb explants. Together, these data suggest that beta-netrin is important in neural, kidney, and vascular development.

The PPARgamma2 polymorphism pro12Ala is associated with better insulin sensitivity in the offspring of type 2 diabetic patients

Recently, a highly prevalent polymorphism of the PPARgamma2-receptor (Pro12Ala) was described and found to be associated with reduced transcriptional activity. Both human and animal studies suggested that this polymorphism may be associated with increased insulin sensitivity. However, an effect independent of other factors known to influence insulin sensitivity has yet to be demonstrated. Therefore, we compared insulin sensitivity using the hyperinsulinemic-euglycemic clamp technique in 37 subjects heterozygous for the PPARgamma2-Pro12Ala mutation and 37 control subjects negative for the PPARgamma2-Pro12Ala. The control group was selected from 190 subjects by pair-matching for sex, BMI, fat distribution and body composition. In the group heterozygous for the polymorphism steady-state plasma insulin during the clamp was significantly lower (63.3 microU/ml +/- 2.8) than in the control group (74.9 microU/ml +/- 4.0, p = 0.02). While MCR of glucose was similar in the PPARgamma2-Pro12Ala group (8.1 ml/kg x min x 100 +/- 0.5) and the control group (7.6 ml/kg x min x 100 +/- 3.0, p = 0.7), the insulin sensitivity index was significantly higher in the PPARgamma2-Pro12Ala group (12.5 mg/kg x min x microU/ml +/- 0.9 vs. 9.7 mg/kg x min x microU/ml +/- 0.8, p = 0.039). In addition, an arbitrary lipolysis index (decrease in FFA divided by increase in insulin) was also found to be marginally higher in the PPARgamma2-Pro12Ala group (8.0 +/- 0.9) compared to the control group (6.1 +/- 0.7, p = 0.097). In conclusion, these data suggest that the PPARgamma2-Pro12Ala mutation is associated with better insulin sensitivity of glucose disposal and possibly, also of antilipolysis.

[Diagnosis and significance of minimal residual disease in patients with colorectal carcinoma]

Progression of malignant tumours to metastatic disease after surgery in curative intent is due to usually few and with conventional diagnostic techniques undetectable residual malignant cells. These cells must have been spread either before or during surgery. The more sensitive and specific detection of these malignant cells in various clinically relevant compartments of the patients organism became possible through new immunocytochemical and molecular tools. Various clinical studies underline the strong prognostic impact of the detection of disseminated cancer cells. However, many technical aspects did not yet allow sufficient standardization of these procedures and led to significantly varying results among different scientific groups. It is one of our primary aims to test, whether the detection of disseminated cancer cells might guide the indication for adjuvant therapies and might predict the efficacy of therapies in patients with solid cancers.

Role of muscles accumbens dopamine D1 and D2 receptors in instrumental and Pavlovian paradigms of conditioned reward

RATIONALE

This study investigated the role of nucleus accumbens dopamine D1 and D2 receptors in two different paradigms of conditioned reward.

OBJECTIVE

We addressed the question whether accumbal dopamine is important for the motor or for the motivational components of reward.

METHODS

We compared the effects of intra-accumbal infusion of the dopamine D1 receptor antagonist SCH23390 (0.3, 1.0, 3.0 microg) and the D2 receptor antagonist sulpiride (0.3, 1.0, 3.0 microg) on conditioned lever pressing for food, with the effects on the inhibition of the startle response by a conditioned reward signal.

RESULTS

Both the D1 and the D2 antagonist dose-dependently attenuated conditioned lever pressing for reward under a fixed-ratio of responding and increased the consumption of freely available lab chow. However, the preference for freely available pellets, and the attenuation of the startle response in the presence of a conditioned stimulus predicting reward were not impaired by blockade of accumbal dopamine receptors.

CONCLUSIONS

Our data support the idea that dopamine in the nucleus accumbens is necessary for instrumental response selection in the context of reward rather than for the mere motor performance of behavior or for the evaluation of the hedonic properties of rewarding stimuli.

Laminin expression in adult and developing retinae: evidence of two novel CNS laminins

Components of the extracellular matrix exert myriad effects on tissues throughout the body. In particular, the laminins, a family of heterotrimeric extracellular glycoproteins, have been shown to affect tissue development and integrity in such diverse organs as the kidney, lung, skin, and nervous system. Of these, we have focused on the roles that laminins play in the differentiation and maintenance of the nervous system. Here, we examine the expression of all known laminin chains within one component of the CNS, the retina. We find seven laminin chains-alpha3, alpha4, alpha5, beta2, beta3, gamma2, and gamma3-outside the retinal basement membranes. Anatomically, these chains are coexpressed in one or both of two locations: the matrix surrounding photoreceptors and the first synaptic layer where photoreceptors synapse with retinal interneurons. Biochemically, four of these chains are coisolated from retinal extracts in two independent complexes, confirming that two novel heterotrimers-alpha4beta2gamma3 and alpha5beta2gamma3-are present in the retinal matrix. During development, all four of these chains, along with components of laminin 5 (the alpha3, beta3, and gamma2 chains) are also expressed at sites at which they could exert important effects on photoreceptor development. Together, these data suggest the existence of two novel laminin heterotrimers in the CNS, which we term here laminin 14 (composed of the alpha4, beta2, and gamma3 chains) and laminin 15 (composed of the alpha5, beta2, and gamma3 chains), and lead us to hypothesize that these laminins, along with laminin 5, may play roles in photoreceptor production, stability, and synaptic organization.

Amygdaloid N-methyl-D-aspartate and gamma-aminobutyric acid(A) receptors regulate sensorimotor gating in a dopamine-dependent way in rats

Sensorimotor gating can be measured as prepulse inhibition of the startle response in humans and rats. Since prepulse inhibition is impaired in schizophrenics there is considerable interest in understanding the neuronal basis of prepulse inhibition. Neuropathological findings indicate a dysfunction of the glutamatergic and GABAergic system in cortico-limbic areas in schizophrenics. We tested whether blockade of N-methyl-D-aspartate or GABA(A) receptors in the basolateral amygdala affects prepulse inhibition in rats. Local infusion of the N-methyl-D-aspartate receptor antagonist dizocilpine (0, 6.25 microg/0.5 microl), or of the GABA(A) receptor antagonist picrotoxin (0, 5.0, 10.0 ng/0.5 microl) reduced prepulse inhibition. The prepulse inhibition-disrupting effect of 6.25 microg dizocilpine or 10.0 ng picrotoxin was reversed by systemic co-administration of the dopamine antagonist haloperidol (0.1mg/kg i.p.). These data indicate that sensorimotor gating is regulated in a dopamine-dependent way by N-methyl-D-aspartate and GABA(A) receptors in the basolateral amygdala. Our findings are discussed with respect to neuropathological findings in schizophrenics.

Asthma severity, recommended changes of inhaled therapy and exhaled nitric oxide in children: a prospective, blinded trial

Orally exhaled nitric oxide (ENO) correlates with several variables of airway inflammation and might be useful to direct asthma therapy. If this is true, ENO should correlate with disease severity and the therapeutic decisions made. - In 74 children with allergic asthma (age 9.7 years, range 4-16) disease severity was determined by history, clinical symptoms, and lung function and inhaled therapy was adjusted according to the NIH criteria. ENO was also measured, but the patients, their parents and the physicians who made the therapeutic decision were left unaware of the results. 31 healthy children served as controls. ENO was higher in asthmatics than in controls, but did not differ with asthma severity. ENO was weakly correlated with the changes in asthma therapy recommended (r = 0.303, P = 0.009). ENO values above normal (> 13 ppb) had a sensitivity of 0.67 and a specificity of 0.65 to predict a step up in therapy. Due to the non-normal distribution of ENO there was a substantial overlap between the different groups. The lack of correlation with disease severity and the weak prediction of physician recommended inhaled therapy, suggest that ENO may be of some value to guide asthma therapy. Studies using ENO to direct therapy are necessary for a definite answer.

Bone morphogenetic protein 1 is an extracellular processing enzyme of the laminin 5 gamma 2 chain

Epithelial cells maintained in culture medium containing low calcium proteolytically process laminin 5 (alpha3beta3gamma2) within the alpha3 and gamma2 chains (). Experiments were designed to identify the enzyme(s) responsible for the laminin 5 processing and the sites of proteolytic cleavage. To characterize the nature of laminin 5 processing, we determined the N-terminal amino acid sequences of the proteolytic fragments produced by the processing events. The results indicate that the first alpha3 chain cleavage (200-l65 kDa alpha3) occurs within subdomain G4 of the G domain. The second cleavage (l65-l45 kDa alpha3) occurs within the lIla domain, 11 residues N-terminal to the start of domain II. The gamma chain is cleaved within the second epidermal growth factor-like repeat of domain Ill. The sequence cleaved within the gamma2 chain matches the consensus sequence for the cleavage of type I, II, and III procollagens by bone morphogenetic protein-1 (BMP-1), also known as type I procollagen C-proteinase (). Recombinant BMP-1 cleaves gamma2 in vitro, both within intact laminin 5 and at the predicted site of a recombinant gamma2 short arm. alpha3 is also cleaved by BMP-1 in vitro, but the cleavage site is yet to be determined. These results show the laminin alpha3 and gamma2 chains to be substrates for BMP-1 in vitro. We speculate that gamma2 cleavage is required for formation of the laminin 5-6 complex and that this complex is directly involved in assembly of the interhemidesmosomal basement membrane. This further suggests that BMP-1 activity facilitates basement membrane assembly, but not hemidesmosome assembly, in the laminin 5-rich dermal-epidermal junction basement membrane in vivo.

Detection of hematogenic tumor cell dissemination in patients undergoing resection of liver metastases of colorectal cancer

OBJECTIVE

To determine the extent of pre- and intraoperative hematogenic tumor cell dissemination in patients undergoing liver resection for metastatic colorectal cancer.

SUMMARY BACKGROUND DATA

For patients with hepatic metastases of colorectal cancer, liver resection is the only potentially curative therapy. However, 38% to 53% of patients develop extrahepatic tumor recurrence, probably caused by tumor cells disseminated before or during surgery not detected by current staging systems.

METHODS

Blood samples harvested before, during, and after surgery from 41 patients and bone marrow samples from 30 patients undergoing resection of liver metastases of colorectal cancer were analyzed for disseminated tumor cells using cytokeratin 20 reverse transcriptase-polymerase chain reaction.

RESULTS

Tumor cells were detected in the blood samples of 26 of the 41 patients (63.4%) and in the bone marrow samples of 8 of the 30 patients (26.7%). Tumor cells were detected significantly more often during surgery than before or after surgery. Intraoperative tumor cell dissemination was detected in 41.7% of patients undergoing resection of two or more liver segments but only 14.3% of patients undergoing resection of one liver segment. Compared with resection of primary colorectal cancer, major liver resection carries an increased risk for intraoperative tumor cell dissemination.

CONCLUSIONS

Detection of disseminated tumor cells in patients undergoing liver resection for metastases of colorectal cancer using cytokeratin 20 reverse transcriptase-polymerase chain reaction might help to identify patients at high risk for tumor recurrence who may benefit from adjuvant therapy. Major liver resection of metastases leads to frequent intraoperative tumor cell shedding, possibly preventable by alternative surgical strategies.

Comparative genome analysis reveals extensive conservation of genome organisation for Arabidopsis thaliana and Capsella rubella

Genome colinearity has been studied for two closely related diploid species of the Brassicaceae family, Arabidopsis thaliana and Capsella rubella. Markers mapping to chromosome 4 of A. thaliana were found on two linkage groups in Capsella and colinear segments spanning more than 10 cM were revealed. Detailed analysis of a 60 kbp region in A. thaliana and its counterpart in C. rubella showed virtually complete conservation of gene repertoire, order and orientation. The comparison of orthologous genes revealed very similar exon-intron structures and sequence identities of 90% or more were found for exon sequences. This extensive genome colinearity at the genetic and molecular level allows the efficient transfer of data from the well-studied A. thaliana genome to other species in the Brassicaceae family, substantially facilitating genome analysis studies for species of this family.

Pharmacoeconomic impact of rational use guidelines on the provision of analgesia, sedation, and neuromuscular blockade in critical care

OBJECTIVE

To determine the cost-effectiveness and safety of a set of rational use guidelines for analgesia, sedation, and neuromuscular blockade in critically ill ventilated patients when compared with similar factors in standard prescribing.

DESIGN

Prospective cost-benefit analysis.

SETTING

Medical and surgical intensive care units (ICU) of a 350-bed tertiary care university hospital.

PATIENTS

Patients admitted to our ICUs who required mechanical ventilation and continuous analgesics, sedatives, and/or neuromuscular junction blockers (NMJBs). There were 72 patients in the baseline and 84 patients in the follow-up groups.

INTERVENTIONS

Prospective tracking of eligible baseline patients was followed by the development and introduction of guidelines and an academic detailing process to promote the use of guidelines. Several months after the introduction of guidelines, a second group of eligible follow-up patients was tracked. The use and effectiveness of analgesics, sedatives, and NMJBs, as well as cost and outcomes, were followed in both groups. Data were subsequently reviewed and analyzed.

MEASUREMENTS AND MAIN RESULTS

We recorded data by means of Paradox and Excel databases and included demographics, costs, outcomes (including adverse drug reactions, functional status, ventilator time in hours, lengths of stay), and mortality rates. Data were subsequently analyzed via the Winks statistical data analysis program. Both groups were similar with regard to demographics. There was a statistically significant increase in severity of illness in the follow-up group without a statistically significant increase in mortality. Direct drug costs, ventilator time, and lengths of stay were reduced in the follow-up group. In addition, the use of NMJBs was reduced from 30% in the baseline group to 5% in the follow-up group.

CONCLUSIONS

Rational use guidelines resulted in safe, cost-effective improvements in the provision of continuous analgesia, sedation, and neuromuscular blockade to critically ill patients requiring ventilator management when compared with similar factors in baseline prescribing strategies.

Association of a polymorphism in the TNFR2 gene with low bone mineral density

Previous genetic linkage data suggested that a gene on chromosome 1p36.2-36.3 might be linked to low bone mineral density (BMD). Here, we examine the gene for tumor necrosis factor receptor 2 (TNFR2), a candidate gene within that interval, for association with low BMD in a group of 159 unrelated individuals. We assess two polymorphic sites within the gene, a microsatellite repeat within intron 4, and a three-nucleotide variation in the 3' untranslated region (UTR) of the gene. The latter has five alleles of which the rarest allele is associated with low spinal BMD Z score (p = 0.008). Lowest mean spinal BMD Z scores were observed for individuals having genotypes that were heterozygous for the rarest allele. No homozygotes for the rarest allele were observed. Preliminary analysis suggests that there is a difference in the genotype frequency distribution between the group with low BMD and a control group.

Synthesis and cytotoxic and antitumor activity of benzo[b]pyrano[3, 2-h]acridin-7-one analogues of acronycine

Benzo¿băcronycine (6-methoxy-3,3,14-trimethyl-3, 14-dihydro-7H-benzo¿bpyrano¿3,2-hăcridin-7-one, 4), an acronycine analogue with an additional aromatic ring linearly fused on the natural alkaloid basic skeleton, was synthesized in three steps, starting from 3-amino-2-naphthalenecarboxylic acid (5). Eight 1, 2-dihydroxy-1,2-dihydrobenzo¿băcronycine esters and diesters (17-24) were obtained by catalytic osmic oxidation, followed by acylation. All these compounds were significantly more cytotoxic than acronycine, when tested against L1210 leukemia cells in vitro. The potency of the cyclic carbonate 24 was in the range of the most active drugs currently used in cancer chemotherapy. Two selected diesters (17 and 24) were evaluated in vivo against P388 leukemia and colon 38 adenocarcinoma implanted in mice. Both compounds were markedly active at doses 16-fold lower than the dose of acronycine itself. Against colon 38 adenocarcinoma, compounds 17 and 24 were highly efficient, inhibiting tumor growth by more than 80%. Diacetate 17 was the most active, inhibiting tumor growth by 96% at 6.25 mg/kg, with two of seven mice being tumor-free on day 43.

Local photodynamic action of methylene blue favorably modulates the postinterventional vascular wound healing response

PURPOSE

Photodynamic therapy (PDT), the light activation of photosensitizers to produce free radicals, is known to inhibit experimental intimal hyperplasia (IH). However, its clinical application has been limited by the lack of a suitable approach and a clinically appropriate photosensitizer. The aim of this study was to determine the effectiveness of a clinical approach for PDT, while testing its ability to favorably modulate the vascular wound healing response.

METHODS

Rat carotid arteries were balloon-injured (BI), and for PDT, the arteries were irradiated with thermoneutral laser light (lambda = 660 nm, 100 J/cm(2)) after the photosensitizer methylene blue (MB) was delivered locally. Control rats included BI alone and MB after BI alone. Arteries were analyzed after 2 weeks with morphometric evaluation (n = 6) and in situ hybridization for versican and procollagen type I gene expression (digitized image pixel analyses, n = 3).

RESULTS

No IH developed in PDT-treated arteries (0 +/- 0 mm(2); compared with BI, 0.192 +/- 0.006 mm(2); P <.0001). The diameters remained unchanged (PDT, 0.95 +/- 0.04 mm; BI, 0.94 +/- 0.05 mm; uninjured artery, 0.91 +/- 0.06 mm). Arterial injury resulted in an increase of versican and procollagen type I messenger RNA (mRNA) in the adventitia and neointima. In the repopulating cells of the adventitia after PDT, there was a significant decrease in versican mRNA (% of positive pixels per high-power field: PDT, 1.13% +/- 0.39%; BI, 2.93% +/- 0.61%; P <.02), but not in procollagen type I mRNA.

CONCLUSION

The decrease of versican mRNA expression of repopulating cells after PDT reflects favorable healing on a molecular level. Site-specific delivery of MB, a clinically appropriate photosensitizer, followed by PDT represents a suitable method to promote favorable healing after balloon intervention and further supports its role for inhibiting postinterventional restenosis.