Growth-inhibitory activity and downregulation of the class II tumor-suppressor gene H-rev107 in tumor cell lines and experimental tumors

The H-rev107 gene is a new class II tumor suppressor, as defined by its reversible downregulation and growth-inhibiting capacity in HRAS transformed cell lines. Overexpression of the H-rev107 cDNA in HRAS-transformed ANR4 hepatoma cells or in FE-8 fibroblasts resulted in 75% reduction of colony formation. Cell populations of H-rev107 transfectants showed an attenuated tumor formation in nude mice. Cells explanted from tumors or maintained in cell culture for an extended period of time no longer exhibited detectable levels of the H-rev107 protein, suggesting strong selection against H-rev107 expression in vitro and in vivo. Expression of the truncated form of H-rev107 lacking the COOH-terminal membrane associated domain of 25 amino acids, had a weaker inhibitory effect on proliferation in vitro and was unable to attenuate tumor growth in nude mice. The H-rev107 mRNA is expressed in most adult rat tissues, and immunohistochemical analysis showed expression of the protein in differentiated epithelial cells of stomach, of colon and small intestine, in kidney, bladder, esophagus, and in tracheal and bronchial epithelium. H-rev107 gene transcription is downregulated in rat cell lines derived from liver, kidney, and pancreatic tumors and also in experimental mammary tumors expressing a RAS transgene. In colon carcinoma cell lines only minute amounts of protein were detectable. Thus, downregulation of H-rev107 expression may occur at the level of mRNA or protein.

How reproducible are measures of the anal sphincter muscle diameter by endoanal ultrasound?

Anal endosonography is an imaging technique for the anal sphincter system and offers analysis of its muscular integrity. It is generally assumed that measurement of the thickness of muscle layers is provided by sonography; however, reproducibility of such measurements have not yet been investigated.

METHODS

Study 1: In 10 healthy volunteers, endoanal ultrasound was performed independently by two experienced investigators with two different ultrasound machines, and thickness of the muscle layers of the internal and external anal sphincter was assessed in the position of the intermediate dorsal anal canal in a randomized cross-over fashion. Study 2: In a study of similar design, sonography was performed in nine healthy volunteers by two investigators independently using a single ultrasound machine in three standardized positions (proximal/intermediate/distal anal canal) and the sphincter layers assessed in the left, right, and dorsal segment.

RESULTS

Study 1: Both the same investigator with different ultrasound scanners and different investigators with the same machine failed to obtain reproducible results with respect to internal and external anal sphincter muscle layer diameter (four bivariate correlations, all with p > 0.05). Study 2: Standardization of the probe position did not improve the agreement (2 x 9 bivariate correlations, all but two p > 0.05).

CONCLUSION

At present, therefore, endoanal ultrasound does not provide reliable morphometric data on anal sphincter muscle diameter. This could explain previously conflicting observations of associations between anal sphincter morphometry and function.

[Cementless fixation of the endoprosthesis using trabecular, 3-dimensional interconnected surface structures]

While the principle of enlarging the surface area has been recognized and used in different ways for some time, there is often no schematic, detailed description or fundamental research. Taking a surface structure consisting of trabecular three-dimensional connecting elements, essential parameters are shown, making it clear that the flexible dynamic reaction of the effective "anchoring space" with a suitable specified shape (construction height, alignment, network) can be reproducibly shaped and used. This has led to a hip endoprosthesis with a graduated surface structure. The construction height of the trabecular structure varies, decreasing from proximal to distal.

[Psychosocial factors in Crohn disease--an overview]

In more than 50 years of psychosomatic research on Crohn's disease, several research hypotheses have been generated, which are critically reviewed here: A disease-specific personality could never be identified, and an important role of psychiatric and psychopathologic personality traits in disease onset was never substantiated. Moreover, most abnormalities found in psychological tests have to be regarded as secondary to chronic illness. Effects of psychologic and social stress on symptoms have not been validated, but it may be that Crohn's patients may have developed less coping abilities with daily hassles. Psychotherapy may improve this, but does not affect the clinical course of the disease.

Contractile response of the isolated trabecular meshwork and ciliary muscle to cholinergic and adrenergic agents

To characterize the contractile properties of isolated trabecular meshwork strips, we measured the effect of various cholinergic and adrenergic substances on the contractility of trabecular meshwork (TM) strips in comparison with the effects on ciliary muscle (CM) strips. Using an electromagnetic force length transducer we performed measurements of isometric tension on isolated bovine TM and CM strips. Isolated strips were contracted by cholinergic agonists, the relative potency being carbachol > pilocarpine > acetylcholine. The half-maximal effective concentration was 2 x 10(-7) mol l(-1) for carbachol and 2 x 10(-6) mol l(-1) for pilocarpine. To characterize muscarinic receptors, we tested selective antagonists for M1 (pirenzepine) and M3 (4-DAMP). Pharmacologically, the functional muscarinic receptors are of the M3 subtype in TM as well as CM. The M1 subtype seems to be less important. The alpha 1-agonist phenylephrine was more effective in inducing contractions in TM than in CM. The alpha 2-agonist brimonidine induced contractions only in TM. In precontracted tissues the beta-agonist isoproterenol induced a relaxation in both tissues. This relaxation could be inhibited by metipranolol. Epinephrine (or dipivefrin) induced small contractions in TM and CM, which became more prominent, especially in TM, when the beta-adrenoreceptors were inhibited by metipranolol. The data indicate the presence of functional muscarinic, alpha-adrenergic, and beta-adrenergic receptors in bovine TM and CM. The contractile properties of TM and CM are differently modulated by the various drugs. Cholinergic and alpha-adrenergic agonists induced contraction, whereas beta-agonists induced relaxation.

Deficient signaling in mice devoid of double-stranded RNA-dependent protein kinase

Double-stranded RNA-dependent protein kinase (PKR) has been implicated in interferon (IFN) induction, antiviral response and tumor suppression. We have generated mice devoid of functional PKR (Pkr%). Although the mice are physically normal and the induction of type I IFN genes by poly(I).poly(C) (pIC) and virus is unimpaired, the antiviral response induced by IFN-gamma and pIC was diminished. However, in embryo fibroblasts from Pkr knockout mice, the induction of type I IFN as well as the activation of NF-kappa B by pIC, were strongly impaired but restored by priming with IFN. Thus, PKR is not directly essential for responses to pIC, and a pIC-responsive system independent of PKR is induced by IFN. No evidence of the tumor suppressor activity of PKR was demonstrated.

Analysis of amount, expenditures and indications of drug and blood product prescriptions at surgical intensive care units

Analysis of indication-related drug prescription patterns is of particular interest with regard to rising costs of the health service being also reflected in higher expenditures for drugs at the University Hospital of the Friedrich-Schiller-University Jena. This is especially important at ICU's, since treatments in patients with acute or chronic multiorgan failure are very expensive. Over a period of 4 months in 1994 the indication-related drug consumption of 2 surgical ICU's of the University of Jena has been recorded and analyzed using a notebook-PC. The total costs of these drugs and blood products, which caused 80% of total costs in the last year, came up to 1,144,773 DM for 465 patients. Nearly two thirds of the recorded expenditures were caused in patients with severe trauma or with acute bleeding. The 10 leading substances (antithrombin III, human albumin 20%, prothrombine complex, etc.) represent 67% of total costs including blood products, antibiotics/antimycotics and IgM enriched intravenous immunoglobulines. Therefore, the indications of these drugs in particular have been further investigated. During and after the study the results have been discussed with the treating medical staff leading to new therapy recommendations. Until the end of 1994 a remarkable cost saving could already be achieved for some drugs by more critical and purposeful use providing same high standard of medical treatment. Blood products have to be included into analyses of indication-related drug administration on the meaning of high costs, difficulties of accurate indication, and possibly undesired side-effects. However, medical and ethical aspects, e.g. minimizing of side-effects, have to take priority over pharmacoeconomical considerations especially in intensive care medicine.

Nuclear matrix condensation and c-myc and c-fos expression are specifically altered in culture rat hepatocytes after exposure to cyproterone acetate and phenobarbital

Regenerative or hyperplastic growth promotes carcinogenesis and can be induced by many nongenotoxic carcinogens. The mitogenic potential of the rodent liver tumor promoters, cyproterone acetate and phenobarbital was investigated in primary rat hepatocyte cultures. Two premitotic markers were analyzed, the expression of two immediate-early genes (c-fos and c-myc) and the decrease in the nuclear quinacrine dihydrochloride fluorescence indicative for a G0-G1 cell cycle shift. C-fos expression and decrease in nuclear fluorescence could be induced by both chemicals, phenobarbital being the lesser potent, whereas c-myc expression was only inducible by cyproterone acetate. In situ hybridization with c-myc revealed that both chemicals enhanced c-myc mRNA levels in individual cells, however the number of responding hepatocytes was increased by cyproterone acetate only. The chemical-induced premitotic changes in hepatocytes were highly specific in terms of affected genes and ploidy levels of responding hepatocytes.

Partial restoration of pre-transformation levels of lysyl oxidase and transin mRNAs in phenotypic ras revertants

Neoplastic transformation mediated by ras oncogenes is associated with deregulated expression of genes encoding, for example, various proteases, lysyl oxidase, and smooth-muscle alpha-actin. To define the role of these genes in the initiation or maintenance of the ras-transformed state, we compared their steady-state mRNA levels in two different sets of preneoplastic fibroblast lines, ras-transformed clones, and phenotypic revertants derived from them. Compared with the preneoplastic fibroblasts, the ras-transformed derivatives exhibited elevated levels of cathepsin L (major excreted protein), transin (stromelysin I, matrix metalloproteinase-3), and collagenase I (matrix metalloproteinase-1) mRNA but undetectable levels of lysyl oxidase mRNA. Partial restoration of lysyl oxidase transcription was observed in four of five phenotypic revertants derived from rat FE-8 and NIHpEJcl3 cells. The elevated levels of transin mRNA found in NIHpEJcl3 cells were diminished to the pretransformation level in interferon revertants but were not reduced in phenotypic rat FE-8 revertants expressing a high level of the ras oncoprotein. High steady-state levels of collagenase I mRNA were dependent on ras expression but were not closely associated with the transformed phenotype. High levels of cathepsin L mRNA were associated with neither high ras expression nor neoplastic transformation. The downregulation of smooth-muscle alpha-actin, characteristic of transformed cell lines, was not reversible in phenotypic revertants.

[A thermal flow sensor for infusion technique]

A flow sensor for measuring flow rates in infusions systems, which is thus suitable for infusion monitoring, is described. The sensor employs a combination of thermal heating and thermal tracing to determine the flow rate. Heating and sensing elements are applied to the outside of the infusion tubing, so that measurement does not compromise the integrity of the tubing. Through the use of two sensor units measurement can be made independently of position.

IP3 receptor purified from liver plasma membrane is an (1,4,5)IP3 activated and (1,3,4,5)IP4 inhibited calcium permeable ion channel

The IP3 receptor is involved in Ca2+ mobilization from intracellular stores. Recently, we purified an inositol (1,4,5)-trisphosphate receptor from rat liver plasma membrane (LPM-IP3R) [Schäfer R. Hell K. Fleischer S. (1993) Purification of an IP3 receptor from liver plasma membrane. Biophys. J. 66, A146]. The purified LPM-IP3 receptor was incorporated into vesicle derived planar bilayers and its channel properties characterized. The receptor displayed ion channel activity that was activated by inositol (1,4,5)-trisphosphate [(1,4,5)IP3] (1 microM) and inhibited by inositol (1,3,4,5)-tetrakisphosphate (IC50 approximately 1 microM) and by heparin (IC50 approximately 20 micrograms/ml). The channel displays a unitary conductance of 9 pS, and 13 pS in symmetrical 100 mM and 500 mM KCl, respectively, and in symmetrical 250 mM cesium methanesulfonate the slope conductance is 11 pS. Activation by (1,4,5)IP3 is specific to the cis-side of the chamber, equivalent to the cytoplasmic face. The receptor is a Ca2+ permeable ion channel based on ion selectivity (Ca2+ > K+ > Na+ >> Cl). The LPM-IP3 receptor was also permeable to Cs (Cs+ > or = K+), similar to other intracellular Ca2+ release channels, i.e. the IP3 receptor from brain and smooth muscle (IP3R-1) and the ryanodine receptor from skeletal muscle (RyR-1) and heart (RyR-2). Channel activity is not voltage dependent (+/- 100 mV applied voltage). The channel is activated by ATP and Ca2+. The open probability of the (1,4,5)IP3 activated channel activity displays a bell shaped response to cis Ca2+ ion concentration of our system. The LPM-IP3 receptor differs from intracellular IP3R-1 in that the Ca2+ and ATP concentration required for maximum activation is about 10 times higher as compared with IP3R-1 from brain cerebellum and smooth muscle. We conclude that the LPM-IP3 receptor is an (1,4,5)IP3 activated Ca2+ permeable ion channel. The implication of our studies is that in liver, (1,4,5)IP3 regulates Ca2+ influx via the plasma membrane.

Expression of ril, a novel LIM domain gene, is down-regulated in Hras-transformed cells and restored in phenotypic revertants

Several candidate genes involved in the maintenance of normal growth control (H-rev) were identified by differential expression cloning on the assumption that they are expressed in phenotypically normal rat cells and repressed in closely related H-ras transformed cells. Previously the genes coding for lysyl oxidase (H-rev142) and for an 18K-protein of unknown function (H-rev107) were recovered as cDNAs by subtraction cloning. Here we describe the identification and expression pattern of ril, a novel member of the heterogeneous group of genes encoding proteins with LIM/double zinc finger domains. The ril gene is expressed in normal fibroblasts and down-regulated in H-ras-transformed derivatives. Expression is restored in several independent phenotypic revertants derived from H-ras transformed cells. The predicted protein product of ril harbors a single LIM domain but lacks a homeodomain. The ril gene is highly conserved during evolution and is transcribed in various normal cell lines. Northern blot analysis and in situ hybridization studies showed that ril is expressed in meiotic spermatocytes, in somites of developing mice, and in a wide variety of tissues of adult mice.

Diagnosis of penile hemangioma by use of biopty gun for corpus cavernosum biopsy

Penile hemangiomas are very uncommon mesenchymal tumors with less than 20 cases described in the literature. We report on a case of sclerosing hemangioma of the corpus cavernosum diagnosed by MRI and needle biopsy. MRI could delineate the exact anatomical relationship of the hemangioma, corpus cavernosum, tunica albuginea and Buck's fascia. However, the tumor revealed an unspecific inhomogeneous high and low signal intensity shown to be typical for carcinoma, inflammation, fibrosis or plaques. MRI cannot distinguish between benign and malignant penile tumors. A needle biopsy was performed with the Biopty gun and a good tissue sample was obtained for pathological analysis. Our case report demonstrates that this technique is rapid, safe, painless and effective in obtaining adequate tissue samples for microscopic studies. Since sclerosing hemangioma is a benign tumor and the patient was asymptomatic, no further treatment had to be performed.

P53 mutations and loss of heterozygosity on chromosomes 8p, 16q, 17p, and 18q are confined to advanced prostate cancer

We analysed 39 prostatic carcinomas for loss of heterozygosity on chromosomal arms 8p, 10q, 16q, 17p and 18q and for mutations in the p53 anti-oncogene. Loss of heterozygosity (LOH) on 8p was detected in one out of 5 informative tumors, LOH on 16q in 3 out of 21 tumors, LOH on 17p in 2 out of 18 tumors, and LOH on 18q in 2 out of 17 tumors. No deletions were observed on 10q in 14 informative tumors. p53 alterations occurred in 3 out of 38 examined tumors, comprising two point mutations and a small deletion. Chromosomal deletions and p53 mutations were confined to locally invasive prostatic carcinomas, suggesting that they are associated with the progression of some prostate cancers rather than with tumor initiation.

[Detection of verotoxin-producing E. coli in field isolates from domestic and agricultural animals in Sachsen-Anhalt]

A report is given on the detection of verotoxin-producing E. coli (VTEC) strains from field isolates of healthy or ill cattle (n = 141), pigs (n = 306), sheep (n = 15), cats (n = 29) and dogs (n = 25) in the region of the new federal land Sachsen-Anhalt. 5% of the strains isolated from cattle, 32% from pigs, 20% from sheep, 4% from dogs and 0% from cats have shown VTEC. The E. coli-strains were checked for the presence of other factors of virulence, too. A good correlation (82%) was found between the colonization factor F107 and SLT 2/2v-containing strains from pigs in the region of Sachsen-Anhalt, too. Enterohemolysin was not found in SLT 2/2v-positive strains. 91% of the VTEC, isolated from pigs, produced alpha-Hemolysin. The correlation of SLT-containing strains and the production of enterohemolysin was confirmed for ruminants, only. Plasmidprofilings of VTEC from pigs showed mainly a 60 MDa or a 68 MDa plasmid or both, too. The occurrence of heat labile (LT) and in some cases of heat stable (ST) toxin was also checked, to differentiate the VTEC-strains from the enterotoxigenic E. coli strains (ETEC). These investigations showed, that VTEC produce SLT almost without exception. Correlations and conclusions on the pathogenicity for humans are discussed.