Alveolar epithelial type II cell apoptosis in vivo during resolution of keratinocyte growth factor-induced hyperplasia in the rat

Keratinocyte growth factor (KGF) induces rapid and transient hyperplasia of alveolar epithelial type II cells. We sought to determine components of the apoptotic process involved in the resolution of this hyperplasia and the fate of the apoptotic cells. Rats received intrabronchial instillation of 5 mg KGF/kg body weight or diluent. Lungs were fixed 1, 2, 3, 5, and 7 days later. Apoptosis was identified by TdT-mediated dUTP nick-end labeling (TUNEL), double-labeling for TUNEL and the type II cell marker MNF116, and electron microscopy. Fas, FasL, Bax, Bcl-2, and pro- and active caspase-3 were studied by immunohistochemistry. Changes were quantified by stereology. Cell type specificity was investigated by immunofluorescence double staining. Type II cells exhibited Fas, FasL, Bcl-2, and procaspase-3 irrespective of treatment and time. Immunoelectron microscopy revealed Fas at the apical type II cell membrane. Bax staining was prominent in controls (45-95% of type II cell surface fraction), markedly decreased during hyperplasia at days 2 (20-40%) and 3 (0-10%), and reappeared at day 7 (25-45%) when apoptosis was prominent. Remnants of apoptotic type II cells were incorporated in membrane-bound vacuoles of type II cell neighbors as well as alveolar macrophages. The results indicate that type II cells can enter the Fas/FasL/caspase-3 pathway regulated by Bax and Bcl-2. High Bcl-2:Bax levels favor type II cell survival and a low rate of apoptosis during hyperplasia. Low Bcl-2:Bax levels favor type II cell apoptosis during resolution. Because of time-dependent changes that occur within a short time, the KGF-treated rat lung provides a useful in vivo model to investigate apoptosis in the context of tissue remodeling and repair.

[Methods for checking up screening tests for detection of shiga toxin producing Escherichia coli (STEC) using PCR]

Methods for making check ups of STEC-Screening-PCRs by using internal and external systems are given. A control-DNA with identical primer binding sites in relation to the target-DNA (stx-genes) was produced and by HPLC-chromatography quantified. It was used in an internal system. But we had to use too high concentrations of this DNA for making the check up in each sample. A false negative result could be shown in samples with a low stx content as a result of this coamplification process. Therefore we used an external system. A control-DNA with heterologous primer binding sites in relation to the stx-screening-PCR and the special primers were given in each vessel. The optimized system was used for making investigations of some faecal samples from cattle.

Evaluation of urinary bladder cancer antigen as a marker for diagnosis of transitional cell carcinoma of the urinary bladder

The purpose of the present study was to assess a new quantitative urinary tumor marker for transitional cell carcinoma of the urinary bladder (TCC), measuring fragments of cytokeratin 8 and 18 in the urine (UBC). Urine samples of 355 individuals (77 healthy volunteers, 111 patients with benign urologic disorders, 167 patients with histologically proven bladder cancer) were examined for the presence of UBC antigen. Samples of all patients were obtained prior to therapy. Compared to healthy volunteers or patients with benign urologic disease, patients with TCC had significantly higher median urinary levels of UBC antigen (0 vs. 4.18 vs. 7.46 microg/g creatinine; p<0.001, and p<0.01, respectively). UBC antigen levels were positively correlated with tumor grade and stage. Patients with invasive TCC had significantly higher levels of UBC antigen than patients with superficial TCC (p<0.001). Elevated levels of UBC antigen were also found in patients with benign urologic disorders (median: 4.18 microg/g creatinine vs. 7.46 microg/g creatinine in cancer patients). Using a cutoff of 14.06 microg/g creatinine (corresponding to 95% specificity in the group of healthy individuals), sensitivity of UBC antigen ranged between 21.6% (pTa) and 75% (pT4). Overall specificity was 76.6%. Based on our data we conclude that the UBC antigen test in its current format is not clinically useful for detection of bladder cancer.

Early-branching or fast-evolving eukaryotes? An answer based on slowly evolving positions

The current paradigm of eukaryotic evolution is based primarily on comparative analysis of ribosomal RNA sequences. It shows several early-emerging lineages, mostly amitochondriate, which might be living relics of a progressive assembly of the eukaryotic cell. However, the analysis of slow-evolving positions, carried out with the newly developed slow-fast method, reveals that these lineages are, in terms of nucleotide substitution, fast-evolving ones, misplaced at the base of the tree by a long branch attraction artefact. Since the fast-evolving groups are not always the same, depending on which macromolecule is used as a marker, this explains most of the observed incongruent phylogenies. The current paradigm of eukaryotic evolution thus has to be seriously re-examined as the eukaryotic phylogeny is presently best summarized by a multifurcation. This is consistent with the Big Bang hypothesis that all extant eukaryotic lineages are the result of multiple cladogeneses within a relatively brief period, although insufficiency of data is also a possible explanation for the lack of resolution. For further resolution, rare evolutionary events such as shared insertions and/or deletions or gene fusions might be helpful.

Uranium(VI) sulfilimine complexes: a new class of nitrogen analogues of the uranyl ion

The compound tetraphenylphosphonium tetrachlorooxo-S,S-diphenylsulfiliminatouranium, [Ph4P][UOCl4(NSPh2)], has been prepared in high yield from [Ph4P][UOCl5] and [Ph2S=NSiMe3]. An X-ray structure of this compound shows that the uranium atom has a pseudooctahedral geometry with oxygen and nitrogen atoms in trans positions. The structure of the analogous phosphoriminato complex [Ph4P][UOCl4(NPPh3)] has been determined for comparison. Derivatization of the sulfide group shows that only a limited range of functionalization confers stability toward reduction. The emission spectrum of the first electronic excited state reveals a greatly reduced energy compared with that of the uranyl ion. This red shift in the transition is consistent with the weakening of the U-N bond relative to the U-O bond.

[Revascularization of the corpora cavernosa in ischemia-induced erectile dysfunction]

Revascularization of the cavernous bodies (CB) has its place in a highly selected patient population as the only causal therapy for erectile dysfunction (ED) and provides an alternative to the implantation of alloplastic erectile aids. The indication for arterialization of the CB is currently only established when conservative treatment has failed. The most important criteria for the intervention are controversial: an age of under 50, an incidence of not more than two classical risk factors for impotence and the exclusion of diabetes mellitus. The leading revascularization procedure in German-speaking countries comprises arteriovenous shunting of the inferior epigastric artery with the dorsal vein and artery of the penis. A retrospective analysis of results is problematic due to the nonuniform indicational criteria, the multiplicity of applied revascularization procedures and a nonstandardized follow-up. Subjective assessment of improved erectility is the sole target criterion in the majority of studies. Therapeutic results range from 33 to 87% with regard to subjective success rates. Attempts to objectify the treatment results were made in only few of the studies and disclosed bypass patency in 44 to 92% one year after the intervention. The conclusions drawn at the last "Consensus Development Conference on Impotence" (CDCI) of the National Institutes of Health (NIH) in Washington have not lost their topicality in view of the great number of still unanswered questions. There the recommendation was made in 1992 to perform penile arterialization only in controlled prospective clinical trials. The European Urological Association (EUA) is currently organizing a Consensus Conference that will provide the framework for prospective studies that can serve as a basis for clarifying the open questions.

The homodimeric ATP-binding cassette transporter LmrA mediates multidrug transport by an alternating two-site (two-cylinder engine) mechanism

The bacterial LmrA protein and the mammalian multidrug resistance P-glycoprotein are closely related ATP-binding cassette (ABC) transporters that confer multidrug resistance on cells by mediating the extrusion of drugs at the expense of ATP hydrolysis. The mechanisms by which transport is mediated, and by which ATP hydrolysis is coupled to drug transport, are not known. Based on equilibrium binding experiments, photoaffinity labeling and drug transport assays, we conclude that homodimeric LmrA mediates drug transport by an alternating two-site transport (two-cylinder engine) mechanism. The transporter possesses two drug-binding sites: a transport-competent site on the inner membrane surface and a drug-release site on the outer membrane surface. The interconversion of these two sites, driven by the hydrolysis of ATP, occurs via a catalytic transition state intermediate in which the drug transport site is occluded. The mechanism proposed for LmrA may also be relevant for P-glycoprotein and other ABC transporters.

Surgery and intensive care procedures affect the target site distribution of piperacillin

OBJECTIVE

Therapeutic failure of antibiotic therapy has been ascribed to pharmacokinetic alterations in compromised patient populations. The present study, therefore, aimed at examining the influences of cardiac surgery and intensive care procedures on the postoperative target site distribution of piperacillin. For this purpose, the penetration of piperacillin to the interstitial space fluid, the relevant target site for most bacterial infections, was compared between patients after aortic valve replacement and healthy volunteers.

DESIGN

Comparative study in two study populations.

SETTING

The intensive care unit and research ward of a university hospital.

PATIENTS

The study population included six otherwise healthy patients scheduled to undergo aortic valve replacement and a control group of six healthy male volunteers.

INTERVENTIONS

After the administration of a single i.v. infusion of 4.0 g piperacillin, free piperacillin concentrations were measured in the interstitium of skeletal muscle and subcutaneous tissue by in vivo microdialysis and in venous serum. Piperacillin concentrations were assayed with reversed phase high-performance liquid chromatography.

MEASUREMENTS AND MAIN RESULTS

Interstitial piperacillin concentrations in muscle and subcutaneous adipose tissue were significantly lower in patients compared with volunteers with the area under the curve for the interstitium/area under the curve for serum concentration ratios ranging from 0.25 to 0.27 and from 0.43 to 1.22 in patients and volunteers, respectively (p < .05 between groups). The terminal elimination half-life was markedly prolonged in patients, leading to a concomitant increase in t > minimal inhibitory concentration (MIC) values, the relevant surrogate for therapeutic success of therapy with beta-lactam antibiotics, for strains with MIC50 <4 microg/mL. For strains with MIC50 >20 microl/mL, however, inadequate target site concentrations were attained in the patient population.

CONCLUSIONS

During the postoperative and intensive care periods, target site concentrations of piperacillin are markedly altered and decreased. This may also be true for other antibiotic agents and may have clinical implications in that current dosing guidelines may result in inadequate target site concentrations for high-MIC strains. Conceivably, this could lead to therapeutic failure in some patients.

Deletion of the multidrug resistance protein MRP1 gene in acute myeloid leukemia: the impact on MRP activity

Deletion of the multidrug resistance gene MRP1 has been demonstrated in acute myeloid leukemia (AML) patients with inversion of chromosome 16 (inv[16]). These AML patients are known to have a relatively favorable prognosis, which suggests that MRP1 might play an important role in determining clinical outcome. This study analyzed MRP1 deletion by fluorescent in situ hybridization (FISH), with a focus on inv(16) AML patients. Functional activity of multidrug resistance protein (MRP) was studied in a flow cytometric assay with the use of the MRP substrate carboxyfluorescein (CF) and the inhibitor MK-571. MRP1, MRP2, and MRP6 messenger RNA (mRNA) expression was determined with reverse transcriptase-polymerase chain reaction (RT-PCR). The results were compared with normal bone marrow cells. MRP1 deletion was detected in 7 AML patients; 2 cases showed no MRP1 FISH signals, and 5 cases had 1 MRP1 signal, whereas in 4 AML patients with inv(16) no MRP1 deletions were observed. A variability in MRP activity, expressed as CF efflux-blocking by MK-571, was observed (efflux-blocking factors varied between 1.2 and 3.6); this correlated with the number of MRP1 genes (r = 0.91, P <. 01). MRP activity in the AML cases was not different from normal hematopoietic cells. MRP1 mRNA was detected in patients with 1 or 2 MRP1 FISH signals, but not in patients with no MRP1 signals. MRP2 and MRP6 mRNA were expressed predominantly in AML samples with 1 MRP1 signal, whereas in normal bone marrow cells no MRP2 and MRP6 mRNA was observed. In conclusion, this study shows that MRP activity varies among inv(16) AML cases and does not differ from that in normal hematopoietic cells; this might be in part due to the up-regulation of other MRP genes.

Deficient activation of CD95 (APO-1/Fas)-mediated apoptosis: a potential factor of multidrug resistance in human renal cell carcinoma

The pronounced resistance of human renal cell carcinoma (RCC) to anticancer-induced apoptosis has primarily been related to the expression of P-glycoprotein and effective drug detoxification mechanisms. Because the CD95 system has recently been identified as a key mediator of anticancer drug-induced apoptosis, we analysed the contribution of the CD95 system to chemotherapy-induced apoptosis in four newly established RCC cell lines. Here, we demonstrate that all RCC cell lines expressed CD95-receptor and -ligand. Exposure to agonistic anti-CD95 antibodies resulted in induction of apoptosis and significant (P < 0.05) reduction of cell number in three out of four cell lines, indicating that the essential components for CD95-mediated apoptosis were present and functionally intact in the majority of these RCC cell lines. Moreover, treatment of cultures with bleomycin or topotecan, a novel topoisomerase I inhibitor with little substrate affinity for P-glycoprotein, led to induction of apoptosis and significant (P < 0.05) dose-dependent reduction of cell number in all RCC cell lines. Both anticancer drugs also induced upregulation of CD95 ligand expression in all cell lines. Additionally, augmentation of CD95 receptor expression was found in three RCC cell lines, including one p53-mutated cell line, whereas another p53-mutated cell line showed no or only a weak CD95 receptor upregulation after exposure to topotecan or bleomycin, respectively. Despite this upregulation of CD95 receptor and ligand, antagonistic antibodies directed against CD95 receptors or ligands could not inhibit induction of apoptosis by topotecan and bleomycin in any cell line. Thus, although a functionally intact CD95 signalling cascade is present in most RCC cell lines, the anticancer drugs topotecan and bleomycin that induce upregulation of CD95 receptor and ligand fail to effectively activate CD95-mediated apoptosis. This deficient activation of CD95-mediated apoptosis might be an important additional factor for the multidrug resistance phenotype of human RCCs.

[Recovery of balanced anesthesia with various inhalation anesthetics in comparison to intravenous anesthetics: a retrospective analysis of 20,060 patients]

BACKGROUND

The aim of this investigation was to compare routine balanced anaesthesia with different inhalation agents to intravenous anaesthesia (IVA) using an Anaesthesia-Information-Management-System (AIMS) with regard to time of recovery from anaesthesia, the time of discharge from the postanaesthesia care unit (PACU) and postoperative nausea as well as postoperative therapy with analgesics.

METHODS

In 1997 and 1998 all relevant data of each anaesthesia procedure have been recorded using the online documentation Software NarkoData. These data sets have been stored into a relational database during each anaesthesia procedure. For evaluation the information has been exported from the database to a statistics program via 'Structured Query Langvage' (SOL). Balanced anaesthesia has been performed using isoflurane, halothane, and sevoflurane, respectively, supplemented with or without nitrous Oxide (N2O). The intravenous based anaesthesia-groups included propofol-fentanyl or propofol-remifentanil.

RESULTS

The fastest recovery was seen in patients of the isoflurane group (11.2 +/- 7.7 minutes), and the longest time for extubation was observed in patients wich halothane anaesthesia (12.8 +/- 9.3 minutes); the overall mean difference was 1.7 minutes. The earliest patient admitted to the PACU had received sevoflurane (7.0 +/- 6.3 minutes) and propofol-remifentanil (7.0 +/- 7.4 minutes) whereas patients of the halothane group (9.5 +/- 7.5 minutes) took more. The shortest stay in PACU was seen in patients of the sevoflurane and isoflurane groups (105.13 +/- 35.7 and 108.4 +/- 60.5 minutes), whereas propofol-remifentanil (126.2 +/- 89.1 minutes) and halothan (120.0 +/- 86.1 minutes) anaesthetised patients had the longest stay in PACU. No difference was noted in the incidence of postoperative nausea and vomiting nor in the amount of postoperatively given analgesics.

CONCLUSION

Results achieved in routine correspond only in part to results from studies. In our investigation balanced anaesthesia with isoflurane and sevoflurane correspond with the shortest stay in PACU compared to balanced anaesthesia with halothane and IVAs with propofol-fentanyl or propofol-remifentanil. One reason for this could be the intraoperatively administered opioide piritramide in IVAs. Furthermore we conclude that an AIMS may provide additional information about overall costs-effectiveness. However this information depends largely on local factors, e.g. patient case mix, staffing, policy of discharge from the PACU etc.

Association of nonsense mutation of dystrophin gene with disruption of sarcoglycan complex in X-linked dilated cardiomyopathy

BACKGROUND

In a systematic analysis of inherited forms of cardiomyopathy, we previously identified a family with X-linked dilated cardiomyopathy characterised by a mutation in the rod region of dystrophin. We have now attempted to eludicate the genetic mechanism involved in this disease, as well as the role of dystrophin-associated glycoproteins.

METHODS

The affected dystrophin epitope, which lacks binding to the dys-1 antibody, was analysed by single-strand conformation polymorphism analysis, reverse-transcription PCR, and DNA sequencing. Effects on dystrophin-associated glycoproteins were studied by immunohistochemistry and western blotting.

FINDINGS

A translation-termination mutation (C4148T) in exon 29 of the dystrophin gene was found in all affected family members. Alternative splicing rescued the reading frame and led to the expression of a dystrophin molecule lacking 50 aminoacids both in cardiac and skeletal muscle. Immunohistochemical analysis of the dystrophin-associated proteins revealed a reduction of beta-sarcoglycan and delta-sarcoglycan in the sarcolemma of cardiac muscle but not skeletal muscle tissue. However, western blotting revealed similar amounts of sarcoglycan subunits in both tissues.

INTERPRETATION

The molecular mechanism of this subtype of X-linked cardiomyopathy may be explained by a conformational change in exon-29-deleted dystrophin, resulting in disruption of the sarcoglycan assembly in heart muscle but not skeletal muscle.

Assembly of human papillomavirus type 16 pseudovirions in Saccharomyces cerevisiae

Studies of the encapsidation of papillomavirus (PV) DNA, and production of preparative amounts of PVs in vitro, have met with only limited success. To circumvent this problem we established a system in yeast to generate infectious HPV-16 pseudovirions. Saccharomyces cerevisiae strain 1699 was transformed with a construct to allow production of HPV-16 virus-like particles (VLPs). This strain was then transformed with a second construct (target plasmid), the same size as the HPV-16 genome and containing the HPV-16 upstream regulatory region (URR) and the HPV-16 E2 open reading frame. In addition, the target plasmid contained the green fluorescent protein gene to monitor delivery of the target plasmid into mammalian cells after infection. We conclude that this system allows HPV DNA encapsidation because (1) HPV-16 VLPs of two different types (heavy and light) were detected by CsCl gradient centrifugation, (2) DNase I-resistant DNA was detected by PCR/Southern blot analysis in fractions of CsCl gradients at a density corresponding to heavy VLPs, (3) in vitro infection of mammalian cells, including primary mouse splenocytes, with pseudovirions resulted in delivery of the reporter gene as demonstrated by FACS analysis for GFP expression, and (4) after injection of pseudovirions into mice, in vivo reporter gene expression was detected by confocal microscopy in sections of muscle tissue. We conclude that HPV-16 pseudovirions produced in yeast may be useful both for in vitro transduction and for gene delivery in vivo.

Hemodynamic effects of hypertonic hydroxyethyl starch 6% solution and isotonic hydroxyethyl starch 6% solution after declamping during abdominal aortic aneurysm repair

Fluid resuscitation with hypertonic hydroxyethyl starch solutions (HES) is effective in haemorrhagic shock due to the rapid mobilisation of fluids into the intravascular compartment. Declamping of the abdominal aorta with acute redistribution of blood into the vessels of the lower body half causes declamping-induced hypotension. Usually large amount of fluids or vasopressors are necessary to restore hemodynamic stability. Therefore, infusion of a hypertonic colloid solution may be an attractive option to achieve hemodynamic stability. This study was conducted to determine the amount of fluid of either hypertonic HES (HES 6%;7.2% NaCl) or isotonic HES (HES 6%;0.9% NaCl) needed to attain best wedge pressure (PCWP) cardiac index (CI) relation after declamping. Thirty-two high-risk patients undergoing elective abdominal aneurysm resection were enrolled in a prospective, randomised, double blinded study. The individual optimised PCWP/CI relation was determined after induction of anaesthesia. After declamping, both solutions were titrated in small boluses of 100 mL until the previously determined best wedge was reached. The amount of fluid after declamping was significantly reduced in the hypertonic HES- group 162 mL vs. 265 mL in the control group (P < 0.05). Resuscitation time was shortened, and cardiac index was slightly higher in the treatment group. The use of hypertonic HES-solution after aortic declamping led to a significant reduction of fluids necessary to attain optimised PCWP/CI relation. In this clinical trial with moderate blood loss in high-risk patients, hypertonic HES applied in a titrated fashion restored hemodynamic stability faster and without volume overload.

Orientation of the infrared transition moments for an alpha-helix

Appropriate values for the orientation of the amide transition dipoles are essential to the growing use of isotopically edited vibrational spectroscopy generally in structural biology and to infrared dichroism measurements on membrane-associated alpha-helices, in particular. The orientations of the transition moments for the amide vibrations of an alpha-helix have been determined from the ratio of intensities of the A- and E(1)-symmetry modes in the infrared spectra of poly(gamma-methyl-L-glutamate)(x)-co-(gamma-n-octadecyl-L-glutamate)( y) oriented on silicon substrates. Samples possessing a high degree of alignment were used to facilitate band fitting. Consistent results were obtained from both attenuated total reflection and transmission experiments with polarized radiation, yielding values of Theta(I) = 38 degrees, Theta(II) = 73 degrees, and Theta(A) = 29 degrees, relative to the helix axis, for the amide I, amide II, and amide A bands, respectively. The measurements are discussed both in the context of the somewhat divergent older determinations, and in relation to the helix geometry and results on model amide compounds, to resolve current uncertainties in the literature.

Micellar electrokinetic chromatography for the analysis of cefpirome in microdialysis and plasma samples obtained in vivo from human volunteers

Pharmacokinetics of drugs in the human interstitial space fluid can be monitored by means of microdialysis. However, the small-volume microdialysis samples containing low drug concentrations require a sensitive analytical method. In the present study, micellar electrokinetic chromatography (MEKC) is described for the quantification of cefpirome in human microdialysis and plasma samples. Sample preparation of human plasma samples by ultracentrifugation was suitable for comparison of plasma and microdialysate concentrations. Limits of quantification were 2 microg/mL and 0.3 microg/mL for plasma and microdialysate samples, respectively. The limit of detection (LOD) was estimated at 0.2 microg/mL for the plasma and microdialysate samples. In conclusion, MEKC is a reliable and reproducible technique for measuring cefpirome concentrations in microdialysates as well as centrifuged plasma samples.