Laparoscopic repair of pleural laceration produced during truncal vagotomy: case report

A partial pneumothorax developed in a patient undergoing laparoscopic truncal vagotomy when a small pleural laceration was accidentally produced. Changes in oxygen saturation and PETCO2 were immediately detected by the anesthesiologist and measures were taken to maintain the patient's ventilatory stability. The pleural laceration was repaired laparoscopically, and the pneumothorax was corrected by ventilatory manipulation, avoiding the placement of a chest tube. The procedure was completed uneventfully. Literature about the causes of pneumothorax during laparoscopic procedures as well as preventive and therapy viewed.

["Doctor" without being an M.D.--how do non-graduate MDs view medical dissertations?]

Both the ranking and the quality of medical dissertations have for some time been a controversial moot point. Previous studies showed that successful doctorate candidates still regard medical dissertations as a meaningful addition to medical studies. Studies on the views of the value have been placed on a medical dissertation by practising physicians who did not write a dissertation lacking to date. Using an anonymous questionnaire containing 16 questions we carried out a study of all the practising doctors in Mid-Franconia, Germany, who did not write a dissertation (n = 243). We asked about their intentions to write a dissertation, reasons for prematurely breaking off the dissertation and their views on the value of medical dissertations. Evaluation was carried out using descriptive statistics in the sense of an exploratory data analysis. The questionnaire was answered in a usable form by 140 physicians (return quote 58%). The average age of the participants was 44 years (33-89 years). The vast majority (89%) had attempted one or several dissertations, 32% still intended to write a dissertation. 59% regarded writing a dissertation alongside daily practice as very difficult of impossible. Private/family reasons were stated less often than deficits in planning, implementation and supervision for prematurely breaking off the dissertation. 65% of the practising physicians in Mid-Franconia who did not write a dissertation regard medical dissertation today as no longer relevant. 58% are of the opinion that the title "doctor" should be awarded automatically with the final exams. The majority of practising physicians asked had in the meantime given up their intention of writing a dissertation and today tend to disfavour medical dissertations. Nevertheless, one third of those who participated in the study still intend to write a dissertation. In view of this it should be discussed to what extent practising physicians interested in scientific questions can be helped to write a dissertation alongside their daily practice. In particular professors and lecturers of general medicine are called upon to make this possible.

Efficacy of measures of hygiene in workers sensitised to acid anhydrides and the influence of selection bias on the results

OBJECTIVES

Organic acid anhydrides are potential sensitisers and cause occupational airway diseases. In an intervention study the efficacy of measures of hygiene at the workplace and possible selection bias were investigated.

METHODS

A first investigation with 110 workers exposed to hexahydrophthalic acid anhydride (HHPA) and methyltetrahydrophthalic acid anhydride (MTHPA) was carried out in July 1991. The results (skin prick test, specific serum IgE) showed that 20 people were sensitised, and in a challenge test the clinical relevance of the sensitisation was confirmed in six subjects. In December 1991, the hygiene conditions at the plant were improved. In November 1995 a second investigation of 84 people was performed (anamnesis, skin prick test, specific IgE, spirometry, and ambient and biological monitoring). The 27 people who had left the plant in the meantime were asked their reasons for leaving.

RESULTS

The relative risk of people sensitised in 1991 of leaving the plant between 1991 and 1995 was 2.6 (95% confidence interval (95% CI) 1.4 to 4.9) compared with people without any sign of sensitisation. The percentage of people identified as sensitised in 1991, who were still working at the plant and came to the second investigation, was higher than for people without evidence of sensitisation (10/10 v 47/73; p < 0.05). In all the 10 sensitised people in 1991 the findings of the first investigation were confirmed in 1995. The rate of sensitisation in 1995 was 21%. None of the six people employed after 1991 showed evidence of sensitisation. Of the six people with clinically relevant sensitisation confirmed by a challenge test in 1991, five were still at their workplace. From 1991 they were only exposed to MTHPA at a reduced concentration (< 0.5-36 micrograms/m3 in 1995). All of them reported fewer symptoms than in 1991. No signs of bronchial obstruction were detected by spirometry at the workplace.

CONCLUSIONS

In cross sectional studies there is a selection bias with a risk of underestimating the incidence of allergic diseases. The results further suggest that the improved hygiene conditions probably had a positive effect on the symptoms in sensitised people.

Acute normovolaemic haemodilution vs controlled hypotension for reducing the use of allogeneic blood in patients undergoing radical prostatectomy

Blood loss in patients undergoing radical prostatectomy may be substantial. In a randomized, prospective study, we assessed two methods of reducing the need for allogeneic blood transfusion with regard to efficacy and costs. Sixty patients undergoing retropubic radical prostatectomy were allocated randomly to one of three groups. In group 1 (n = 20), acute normovolaemic haemodilution (ANH) was initiated after induction of anaesthesia; autologous blood 15 ml kg-1 was withdrawn and replaced by colloid solutions (gelatin) to maintain haemodynamic stability. In group 2 (n = 20), controlled hypotension was established using sodium nitroprusside (target mean arterial pressure (MAP) approximately 50 mm Hg). Group 3 (n = 20), without manipulations, served as a control group. Troponin T (TnT), a sensitive marker for myocardial ischaemia, and various coagulation variables were measured in the perioperative period. Packed red blood cells (PRBC) were given when haemoglobin concentration was less than 7 g dl-1. Cost calculations did not include hospital overhead costs or staff costs. In the ANH group, mean 1278 (SD 150) ml of autologous blood were withdrawn. Significantly more volume was infused in the ANH patients (gelatin 2450 (550) ml) than in the two other groups. Coagulation data (platelet count, activated partial thromboplastin time (aPTT), fibrinogen, antithrombin III (AT III), D-dimers) did not differ significantly between the three groups. The hypotension group had significantly lower blood loss (1260 (570) ml), whereas the ANH (1820 (680) ml) and control group (1920 (590) ml) did not differ significantly. Patients in the hypotension group needed significantly less PRBC (total 14 units; 75% of patients did not need PRBC) than the ANH (total 21 units; 55% of patients did not need PRBC) or control patients (total 28 units; 40% of patients did not need PRBC). Total costs were lowest in the hypotension group (41% less than in the control patients) (P < 0.05). We conclude that the use of hypotension during radical prostatectomy resulted in approximately 40% reduction in total transfusion costs. ANH was less effective and more costly than controlled hypotension.

Actin binding proteins that change extent and rate of actin monomer-polymer distribution by different mechanisms

Actin binding proteins control actin assembly and disassembly by altering the critical concentration and by changing the kinetics of polymerization. All of these control mechanisms in some way or the other make use of the energy of hydrolysis of actin-bound ATP. Capping of barbed filament ends increases the critical concentration as long as ATP hydrolysis maintains a difference in the actin monomer binding constants of the two ends. A further increase in the critical concentration on adding a second cap, tropomodulin, to the other, pointed filament end also requires ATP hydrolysis as described by the model presented here. Changes in the critical concentration are amplified into much larger changes of the monomer pool by actin sequestering proteins, provided their actin binding equilibrium constants fall within a relatively narrow range around the values for the two critical concentrations of actin. Cofilin greatly speeds up treadmilling, which requires ATP hydroysis, by increasing the rate constant of depolymerization. Profilin increases the rate of elongation at the barbed filament end, coupled to a lowering of the critical concentration, only if ATP hydrolysis makes profilin binding to the barbed end independent of its binding constant for actin monomers.

[Immunoglobulin subclass defects in patients with therapy refractor chronic rhinosinusitis]

In the present study 220 patients suffering from recurrent rhinosinusitis and not responding to antibiotic treatment were evaluated for a defect in IgG-immunoglobulin subclasses. Twenty-one of these patients were found to have an antibody deficiency. These included deficiencies of IgG-2 (n = 10), IgG-1 (n = 6), IgG-3 (n = 1) and IgG-4 (n = 1). A common variable immune disease was diagnosed in three patients that was characterized by an additional defect in the IgG main class. However, an IgG subclass deficiency can only be ascertained by an immunological evaluation. The significance of a deficiency can be identified by a reaction to vaccination using (for example) protein or polysaccharide antigens. Treatment consists of antibiotics, intravenous immunoglobulins and long-term follow-up. Endonasal microsurgery should only be performed in cases that do not respond to conservative treatment. It is particularly necessary to observe these patients because a deficiency of immunoglobulin subclass in certain cases is the first sign of an immunological impairment that can advance to a severe immunodeficiency and predispose to the development of malignancy.

Influence of bolus size on efficacy of postoperative patient-controlled analgesia with piritramide

We have examined the influence of bolus size on efficacy, opioid consumption, side effects and patient satisfaction during i.v. patient-controlled analgesia (PCA) in 60 patients (ASA I-II, aged 32-82 yr) after abdominal surgery. Patients were allocated randomly, in a double-blind manner, to receive PCA with a bolus dose of either piritramide 0.75 mg or 1.5 mg (lockout 5 min) for postoperative pain control. Mean 24 h piritramide consumption differed significantly between groups (11.4 (SD 5.8) mg vs 22.5 (18.3) mg; P = 0.001). There were no significant differences in the number of applied bolus doses, pain scores, pain relief (VAS), sedation, nausea, pruritus and patient satisfaction. We conclude that a PCA regimen with a bolus dose of piritramide 0.75 mg and a lockout time of 5 min was effective in the treatment of postoperative pain, but did not reduce the occurrence of side effects.

Alterations of bacterial clearance induced by propofol

BACKGROUND

The purpose of the study was to investigate the potential influence of the anaesthetic agent propofol on immune function in terms of systemic clearance and organ distribution of injected Escherichia coli in a rabbit model.

METHODS

Defined numbers of E. coli (1.3 x 10(8) colony-forming units, CFU) were injected intravenously 1 h after starting a 4-h infusion of the anaesthetic propofol (2 ml.kg-1.h-1, Disoprivan 1%; n = 6)) or after saline application (n = 6). As propofol is formulated in a 10% lipid emulsion, the lipid vehicle Intralipid (2 ml.kg-1.h-1; n = 6) alone was investigated in a separate group. Parameters monitored were arterial pressure and rates of bacterial elimination from the blood. Three hours after bacterial injection, the animals were killed, and tissue samples of liver, spleen, lung, and kidney were collected for microbiological examinations.

RESULTS

Compared to saline-treated animals, infusion of propofol induced increased accumulation of E. coli in lung and spleen, thus reflecting reticuloendothelial system dysfunction.

CONCLUSION

As the lipid emulsion by itself induced the same effects, the impaired immune function due to propofol is thought to be attributed to its solvent Intralipid.

Continuous infusion of FVIII and FIX concentrates: in vitro analysis of clinically relevant parameters

A high purity factor VIII/von Willebrand Factor (FVIII/vWF) concentrate (IMMUNATE [STIM plus]) (n = 6 batches), and a high purity factor IX (FIX) concentrate (IMMUNINE [STIM plus]) (n = 7 batches), were assessed in vitro for their applicability to continuous infusion. Parameters pertinent to continuous infusion were investigated and included stability, sterility and, in the case of FIX, the generation of potentially thrombogenic components. Four stationary or transportable mini infusion pumps, equipped with polyethylene, polypropylene or polyvinylchloride plastic components were used. The concentrates were reconstituted without extra filling volume and perfused at 12.5 mL h-1 and 1 mL h-1; sampling was carried out at the start of the experiment and for up to 48 h. The FVIII procoagulant activity (FVIII:C) was assayed by amidolytic, 1-stage and 2-stage assays; vWF was examined for ristocetin cofactor activity, antigen and multimers. The FIX coagulation activity (FIX:C) was determined by a 1-stage coagulation assay; thrombogenicity potential was assessed in vivo (Wessler stasis model in rabbits) and in vitro (FIXa and nonactivated thromboplastin time). Reconstituted concentrate incubated under the same conditions served as a control. Both concentrates remained sterile throughout the testing period. The perfused and control samples remained stable, retaining over 95% of activity for FVIII:C and over 90% for FIX:C for up to 48 h. Intermittent decrease of FVIII:C or FIX:C was not observed, suggesting no adsorption of FVIII or FIX onto plastic surfaces during either short or long-term exposure. No thrombogenic components were detected in the high purity FIX concentrate. Thus, under the in vitro conditions used, FVIII/vWF and FIX were found to be suitable for administration by continuous infusion.

Stoppa-type laparoscopic repair of complex groin defects

With the laparoscopic approach, bilateral and complex groin defects can be corrected simultaneously by applying a preperitoneal mesh that covers the entire posterior wall of the groin, using a technique similar to the one described by Stoppa. We present our series of hernias repaired by the transabdominal preperitoneal laparoscopic approach with the Stoppa-type technique. The report consists of 78 cases of bilateral defects, of which 60% were indirect bilateral hernias, 23% direct bilateral, and 17% combined defects; 28.5% were recurrent hernias. Only minor complications were observed (hematomas and urinary retention) in some patients, but all resolved spontaneously. Three recurrences (0.7%) have been seen to this date. This method is recommended as the method of choice for complex groin defects.

[Scopolica carniolica Jacq. tea]

We report a case of plant-poisoning of a young man following the consumption of a self-brewed infusion made of a solanaceous plant, to which he was seduced by his friends. He developed anticholinergic symptoms such as optical hallucinations, confusion, mydriasis and tachycardia. 14 hours after admission the patient was discharged from hospital in good health. With regard to this case we portray the mentioned plant (Scopolica carniolica Jacq.) and discuss the symptoms of belladonna-alkaloid-poisoning and its therapy. Further on, in a short literature survey, we depict the meaning of collective drug experiences with plants containing atropine-like substances in ancient and modern times.

Retrieval of specimens in laparoscopy using reclosable zipper-type plastic bags: a simple, cheap, and useful method

Surgical specimens must often be extracted during laparoscopic surgery. Although the technologic advances in this field are amazing, simple measures may sometimes work even better than very sophisticated instruments. This is true of the reclosable plastic bags with zipper-type closure that we use for retrieving surgical specimens from the abdominal cavity in order to protect it as well as the abdominal wall. The bags are cheap, offer no problems for sterilization, are easy to obtain, and are available in many sizes. They are very simple to handle, making it easy to slip in the specimen and then extract it from the abdominal cavity. We describe our experience with these bags and a technique for manipulating them.

Amphotropic retroviral vectors displaying hepatocyte growth factor-envelope fusion proteins improve transduction efficiency of primary hepatocytes

The development of retroviral vectors with cell-specific targeting capabilities will be an important step toward successful in vitro gene therapy. This article describes the generation of a retroviral vector with enhanced binding abilities for cells bearing the c-Met receptor: the Madin-Darby canine kidney (MDCK) cell line and primary hepatocytes. The human hepatocyte growth factor (HGF) was displayed on murine amphotropic retroviral vectors by fusion to the viral transmembrane envelope glycoprotein (TM). The resulting chimeric envelope HGF-TM was expressed in an amphotropic packaging cell line producing viral particles that display both HGF-TM and the wild-type envelope. These modified viral particles had a titer equivalent to that of unmodified particles. Modified particles infected MDCK cells more efficiently than did unmodified amphotropic retrovirus. Adding anti-HGF antibodies to the viral vector particle supernatant prior to infection confirmed that the increased infection was mediated by the HGF moiety. The chimeric viruses also infected primary mouse and nonhuman primate fetal hepatocytes more effectively. Furthermore, these cells could be induced to proliferate by the modified HGF-TM viruses. Since exogenous HGF is primarily taken up by the liver, these results may have implications for retroviral vector design for liver-directed human gene therapy.

In utero allotransplantation of retrovirally transduced fetal hepatocytes in primates: feasibility and short-term follow-up

In utero allotransplantation of fetal hepatocytes into a preimmune fetus could be used in early treatment of many inherited hepatic metabolic diseases. This study was designed to assess the tolerance to hepatocyte transplantation and to test the feasability and toxicity of such an injection in a primate model. Fetal hepatocytes were obtained from two 120-day-old Macaca mulatta fetuses and cryopreserved. They were thawed, cultured in vitro, and transduced with a recombinant retrovirus expressing beta-galactosidase. Transduction efficiency was 75-85%. Three unrelated fetuses (90, 100, and 104 days old) were each given 1-2 x 10(7) transduced cells via the umbilical vein. This caused vasospasm and severe bradycardia. Two fetuses died in the 48 hours after transplantation; the third survived and was killed at the end of gestation. No evidence of the infused cells was found. Three fetuses (90 days old) were, therefore, given 3-4 10(7) hepatocytes by direct intrahepatic injection. All the fetuses survived without side effect. Donor cells were not apparent from histochemical staining and PCR reactions. There was no evidence of inflammatory reaction. These findings indicate that the protocole could be improved by increasing the number of transplanted cells and using specific hepatic promoters in the retroviral vectors to achieve an effective postnatal chimerism.

[Is subjective health status a good predictor of work resumption?]

The aim of the study is to investigate how persons with long term work-disability due to low back pain assess their health status and how the subjective health measurement influence work resumption (n = 663). Information on their subjective health status at 42 days after start of work-disability is set in relation to the outcomes "Continued work disability after 84 days" versus "work resumption". Bi- and multivariate analysis show that information on the subjective health status and the subjective work prognosis differs between both groups already after 42 days. The results show that the subjective health status in connection with the subjective work prognosis is a good predictor for "Non-resumption of work", but not a sufficiently good predictor for "Resumption to work".

Exclusion of the adrenocorticotropin (ACTH) receptor (MC2R) locus in some families with ACTH resistance but no mutations of the MC2R coding sequence (familial glucocorticoid deficiency type 2)

Several mutations in the coding exon of the ACTH receptor (MC2R) gene have been reported in cases of familial glucocorticoid deficiency or FGD. However, many patients with a similar syndrome do not present any mutation in the coding region of this gene. This is the case in 11 families we have investigated. Patients in these families present the typical clinical features of FGD, but no mutation was found in the coding exon of the ACTH receptor. To determine whether mutations on MC2R gene, but outside the coding region, may be involved in FGD in these families, we have performed a linkage analysis. Using three markers flanking MC2R gene on chromosome 18, we were able to exclude linkage in a region of 12 centimorgans around the gene. This result clearly indicates that FGD is genetically heterogeneous. Defects in gene(s) different from MC2R gene are implicated in this syndrome.

What are the parameters for predictive selection of patients requiring anesthesia for extracorporeal shockwave lithotripsy?

OBJECTIVE

Additional anesthesia is required to minimize the tolerable pain level in efficiently performed extracorporeal shockwave lithotripsy (ESWL) with electrohydraulic and electromagnetic sources. In order to assess optimum anesthesia for each patient undergoing a standardized ESWL protocol, pain measurement and scoring were carried out. We attempted to determine the individual type and amount of analgesia prior to treatment.

METHODS

Patients (n = 95) with urolithiasis underwent pain measurement and scoring prior to ESWL. 'Threshold of pain' (TP) and 'maximal tolerable pain (MTP) were assessed by inducing ischemia pain with the submaximum effort tourniquet technique. Pain intensity was assessed by a verbal rating scale (VRS). The results of pain measurement and amount of analgosedation were correlated in two phases. Patients were administered an oral premedication of 0.1 mg/kg midazolam. Phase 1: 60 patients were randomized into three groups: (1) piritramide (0.1-0.3 mg/kg) and midazolam (1-3 mg) i.v. (2) Lidocaine/prilocaine cream topically (30 g) to skin and diclofenac supp. 100 mg. (3) No analgesia. Phase 2: Based on the data of phase 1, cut-off points for TP and MTP were set for female and male patients. In accordance with these results, 35 patients comprised group 1 for anesthesia with piritramide/midazolam, group 2 with lidocaine/prilocaine cream and diclofenac supp. and group 3 for no analgesia at all. The electromagnetic shockwave sources Modulith SLX and Lithostar Plus were utilized.

RESULTS

Phase 1: All patients randomized for group 1 (intravenous analgosedation) were treated in accordance with the protocol. 65% of group 2 (cream/suppository) tolerated treatment as planned. 35% of patients selected for ESWL without analgesia (group 3) remained within this group. Patients requiring additional analgosedation displayed lower TP and MTP. The cut-off points for females and males were TP >/=25/35 s and MTP >/=45/60 s, respectively. Phase 2: 20/35 patients were preselected for a nonintravenous protocol. Five out of these 20 violated the protocol. The rate of additionally administered analgesia was lower than in phase 1: 35:10% in group 2 (cream/supp.), 65:40% in group 3 (no analgesia).

CONCLUSIONS

The TP and MTP levels are lower in patients requiring stronger analgesia. The determined parameters are suitable for patient preselection and individual assessment of anesthesia prior to ESWL. It may be assumed that 50% of patients administered intravenous opioids are overtreated. Routine pain measurement for patient depends on the individual pain tolerance level. A third phase of this study recruiting a large number of patients will contribute to the confirmation of these results.

Effects of repetitive use and cleaning techniques of disposable jet nebulizers on aerosol generation

STUDY OBJECTIVE

Patients with cystic fibrosis use disposable jet nebulizers for the self-administration of antibiotics, DNase, and bronchodilators several times per day. Most patients elect to reuse their disposable nebulizers. The purpose of this study was to determine if significant changes in particle size distribution or output (mL/min) occurred with reuse.

DESIGN

In vitro studies were performed using four disposable models and one durable jet nebulizer for up to 100 runs; measurements of particle size and output were obtained at 10 run intervals, using saline solution alone, tobramycin, gentamicin, or a mixture of albuterol and cromolyn. Particle size determinations were made with a laser diffraction analyzer.

RESULTS

There was no significant difference between the baseline performance of the four disposable models and the durable Pari LC, when measuring particle size distribution of the aerosol; the Pari LC had an output rate two to three times higher than the four disposable models. For each of the four solutes tested, there was no clinically significant change in performance for up to 100 cycles, when the nebulizers were properly cleaned between uses. Unwashed units containing tobramycin started to fail by 40 runs.

CONCLUSIONS

When properly maintained, there was no trend of deterioration of performance with repeated use of disposable nebulizers. Microbial contamination was not addressed in this study and must be considered prior to recommendations for the reuse of disposable nebulizers.

[Quality circles in expert assessment as an instrument in quality management]

An intercomparison programme was carried out as part of the quality management of medical assessments in the public health service in Baden-Württemberg. All physicians who performed medical assessments in January 1997 were invited to participate. They received a case description adopted from medical records of a precedent case (56-year-old head of a department in an administrative authority, severely disabled after left-sided stroke with residual right-sided partial hemiparesis, reduced work performance), and were asked to assess whether the patient was permanently unable to work. Access to medical expert opinions was requested. Participation was voluntary. Assessments were reviewed twice as to whether five prospectively defined evaluation criteria were fully met, or only partially or not at all. Participants and reviewers remained unknown to each other. Among 246 eligible physicians, 103 returned an assessment (43%). Forty-five respondents had requested additional expert opinions. Anticipations for five criteria were met to their full extent with regard to: formal construction, all submissions; case description, 84%; sociomedical diagnosis, 65%; description of ability to work, 53%; and response to the question posed, 75% of submissions. The programme required considerable work time in its preparatory, field, and evaluation phases. The procedure was however found to be practicable, and a suitable element within a quality management programme can contribute towards motivation, quality assurance and the identification of possible deficits, and thus indicate possible topics and issues for continuing education and quality control programmes.

Microbial communities of printing paper machines

The microbial content of printing paper machines, running at a temperature of 45-50 degrees C and at pH 4.5-5, was studied. Bacteria were prevalent colonizers of the machine wet end and the raw materials. A total of 390 strains of aerobic bacteria were isolated and 86% of these were identified to genus and species by biochemical, chemotaxonomic and phylogenetic methods. The most common bacteria found at the machine wet end were Bacillus coagulans and other Bacillus species, Burkholderia cepacia, Ralstonia pickettii, and in pink slimes, accumulating in the wire area and press section, species of Deinococcus, aureobacterium and Brevibacterium. Paper-making chemicals also contained species of Aureobacterium, B. cereus, B. licheniformis, B. sphaericus, Bordetella, Hydrogenophaga, Klebsiella pneumoniae, Pantoea agglomerans, Pseudomonas stutzeri, Staphylococcus and sometimes other enteric bacteria, but these did not colonize the process water. Yeasts and moulds were not present in significant numbers. A total of 131 strains were tested for their potential to degrade paper-making raw materials; 91 strains were found to have degradative activity, mainly species of Burkholderia and Ralstonia, Sphingomonas and Bacillus, and enterobacteria produced enzymes which degraded paper-making chemicals. Stainless steel adhering strains occurred in slimes and wire water and were identified as Burkholderia cepacia, B. coagulans and Deinococcus geothermalis. Coloured slimes were formed on the machine by species of Deinococcus, Acinetobacter and Methylobacterium (pink), Aureobacterium, Pantoea and Ralstonia (yellowish) and Microbulbifer-related strains (brown). The impact of the strains and species found in the printing paper machine community on the technical quality of paper, machine operation, and as a potential biohazard (Hazard Group 2 bacteria), is discussed.

Mycoplasma nucleases able to induce internucleosomal DNA degradation in cultured cells possess many characteristics of eukaryotic apoptotic nucleases

It was previously shown (Paddenberg et al (1996) Eur J Cell Biol 69, 105 - 119) that cells of established lines like NIH3T3 fibroblasts and the human pancreatic adenocarcinoma PaTu 8902 line only degrade their chromatin at internucleosomal sites after an apoptotic stimulus when infected with Mycoplasma hyorhinis. In order to distinguish mycoplasma nucleases (Mr 47 - 54 kDa) from already described eukaryotic apoptotic enzymes, the mycoplasma nucleases were partially purified from serum-free culture supernatants and further characterized. Here we demonstrate directly that the enriched mycoplasma nucleases were able to fragment the DNA of nuclease-negative substrate nuclei at internucleosomal sites. The DNA degradation was accompanied by morphological changes typical of apoptosis like chromatin condensation and margination followed by shrinkage of the nuclei. The biochemical characterization revealed that the mycoplasma nucleases had a neutral to weakly basic pH-optimum. They required both calcium and magnesium in the mM range for maximal activation and were inhibited by zinc chloride, EGTA and EDTA. In two dimensional zymograms they migrated as three spots with isoelectic points between 8.1 and 9.5. They were not inhibited by monomeric actin. Our data also demonstrate that nuclear extracts prepared from nuclei isolated from Mycoplasma hyorhinis infected cells contained the mycoplasma nuclease activities leading to their internucleosomal DNA-degradation after incubation in the presence of calcium and magnesium.

LU 302 872 and its racemate (LU 224 332) show balanced endothelin-A/B receptor affinity, high oral activity, and inhibit human prostate tissue contractions

LU 302 872 (racemate LU 224 332) is a new glycerinic acid derivative related to the selective ETA receptor antagonist LU 135 252. LU 302 872 exhibits high and balanced affinity to ETA and ETB receptors (Ki 2.2 and 5.8 nmol/L), whereas LU 135 252 is ETA-selective (Ki 1.4 and 184 nmol/L). Two hours after oral treatment of rats with 10 mg/kg of LU 302 872 or of LU 135 252, the big ET-1-induced (20 micrograms/kg i.v.) blood pressure increase is inhibited by 59 +/- 8% or 52 +/- 2% (n = 6-8; p < 0.05 vs. control), whereas bosentan is without effect (-6 +/- 7%; n = 6). In guinea pigs, 10 mg/kg p.o. of LU 302 872 inhibited the big ET-1 (20 micrograms/kg i.v.)-induced bronchospasm (reduction in respiratory volume) by 78 +/- 7% (n = 6; p < 0.05), whereas the ETA antagonist LU 135 252 was ineffective (0.2 +/- 37%; n = 6). Hence, a high oral effectiveness of the new ETA/B antagonist could be demonstrated in two species for both an ETA- or an ETB-mediated response. In human prostate tissue (excised during cystectomy in bladder cancer patients), ET-1 and in most cases, the ETB agonist sarafotoxin 6c (S6c) caused contractions of similar magnitude but more sustained than that of norepinephrine (10(-6) mol/L). A high concentration (10(-5) mol/L) of the ETA antagonist LU 135 252 only moderately attenuated ET contractions. The ETA/B antagonist LU 302 872 or its racemate, LU 224 332, dose-dependently inhibited ET-1-induced contractions. S6C dose-response curves, too, were shifted to the right or suppressed by the combined ETA/B antagonist (10(-6) mol/L LU 224 332). LU 302 872 may be a suitable candidate for testing in benign prostate hyperplasia (BPH).