Splice variants of human cathepsin L mRNA show different expression rates

Human cathepsin L (hCATL) mRNA occurs in vivo in at least three splice variants. They differ in the length of exon 1, which comprises 278 nucleotides (hCATL-A), 188 nucleotides (hCATL-A2) and 132 nucleotides (hCATL-A3), respectively. We describe here the shortest variant for the first time. This form is predominant in all tissues and cells examined so far, including malignant tumors. We studied the expression rate of the three mRNA variants in order to explain why malignant kidney tumors show low cathepsin L activity despite of high mRNA levels. The variant hCATL-A3 showed the highest expression rate in vitro and in vivo. Based on these results, we suggest a cis-acting element on human cathepsin L mRNA which can be bound by a negative trans-acting regulator, thus leading to reduced expression rates.

Citation characteristics of research published in Emergency Medicine versus other scientific journals

STUDY OBJECTIVE

We sought to examine how a cohort of published emergency medicine research is cited in scientific journals.

METHODS

Data were collected on all research submitted to the 1991 Society for Academic Emergency Medicine meeting and subsequently published. Outcome measures included all citations of these studies found in journals listed in the Science Citation Index, as well as the impact factors (citations per manuscript per year) of citing journals.

RESULTS

Two hundred four of the 493 submitted studies were published and met study entry criteria; the average article was cited 2.04 times a year during the study period. Twelve percent were never cited, and 39% were cited only once or twice. Thirty percent were published in non-emergency medicine journals, and these were cited at least twice as often (and by almost 3 times as many journals) as apparently similar studies published in emergency medicine journals. The percentage of studies never cited by anyone was about threefold higher when published in emergency medicine journals. Forty-two percent of the citations of research published in emergency medicine journals came from within the specialty. Emergency medicine journals provided only 16% of the citations of emergency medicine research published in non-emergency medicine journals because these studies were cited 3 times as often by authors in other disciplines. Rejection of research for presentation at the meeting did not predict the number or quality of citations or citing journals.

CONCLUSION

Research submitted to the Society for Academic Emergency Medicine meeting and subsequently published is cited about as often as the average scientific journal article but receives more impact, is cited more widely, and is more likely to be cited by a broader range of authors when published by non-emergency medicine journals. The ability of emergency medicine journals to compete with larger non-emergency medicine journals for their larger audiences may help shape perceptions of the specialty.

Neural components of distension-evoked secretory responses in the guinea-pig distal colon

1. Using a Ussing chamber and neuronal retrograde tracing with 1,1'-didodecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) we characterized the afferent and efferent neuronal pathways which mediated distension-evoked secretion in the guinea-pig distal colon. 2. Acute capsaicin application (10 microM) to the serosal site of the Ussing chamber evoked a secretory response which was blocked by tetrodotoxin (1 microM), the combined application of the NK1 and NK3 receptor antagonists CP-99,994-1 and SR 142801 (1 microM), and by combined application of atropine (10 microM) and the VIP receptor antagonist VIP(6-28) (10 microM). Functional desensitization of extrinsic primary afferents by long-term application of capsaicin significantly diminished distension-evoked secretion by 46 %. 3. After functional desensitization by capsaicin, serosal application of gadolinium (100 microM) inhibited the distension-evoked chloride secretion by 54 %; the L-type Ca(2+) channel blocker nifedipine (1 microM) and the 5-HT(1P) receptor antagonist renzapride (1 microM) had no effect. The combination of atropine and VIP(6-28) or the combination of NK1 and NK3 receptor antagonists almost abolished distension-evoked secretion. 4. The secretory response evoked by electrical field stimulation, carbachol (1 microM) or VIP (1 microM) was not attenuated by gadolinium. Field stimulation-evoked chloride secretion was not affected by blockade of NK1 and NK3 receptors. 5. Twelve per cent of DiI-labelled submucosal neurones with projections to the mucosa were immunoreactive for choline acetyltransferase, substance P and calbindin and very probably represented intrinsic primary afferent neurones. 6. Distension-evoked chloride secretion was mediated by capsaicin-sensitive extrinsic primary afferents and by stretch-sensitive intrinsic primary afferent neurones. Both the extrinsic and intrinsic afferents converge on common efferent pathways. These pathways consist of VIPergic and cholinergic secretomotor neurones that are activated via NK1 and NK3 receptors.

Cathepsin K--a marker of macrophage differentiation?

Cathepsin K is a cysteine protease with high matrix-degrading activity. Initially, cathepsin K was described as being expressed exclusively by osteoclasts. It was suggested that cathepsin K expression is a specific feature of cells involved in bone remodelling. The aim of this study was to investigate the hypothesis that cathepsin K is expressed not only in bone-resorbing macrophages, but also more generally in specifically differentiated macrophages, such as epithelioid cells and multinucleated giant cells in soft tissues. Specimens obtained from different organs and anatomical locations of patients suffering from sarcoidosis, tuberculosis, granulomas caused by foreign materials, and sarcoid-like lesions were investigated for the expression of cathepsins B, K, and L. Immunohistochemistry and in situ hybridization showed cathepsin K in epithelioid cells and multinucleated giant cells irrespective of the pathological condition and anatomical location, but not in normal resident macrophages. By immunoelectron microscopy, cathepsin K was discovered in cytoplasmic granules of multinucleated giant cells. In contrast, cathepsin B and cathepsin L were expressed ubiquitously in CD68-positive tissue macrophages, epithelioid cells, and multinucleated giant cells. The results demonstrate that cathepsin K, but not cathepsin B or cathepsin L, differentiates specific phenotypes of macrophages independently of the anatomical site. Its enzymatic characteristics, particularly its high matrix-degrading activity, suggest that cathepsin K-positive epithelioid cells and multinucleated giant cells are characterized by an enhanced specific proteolytic capability.

Recent advances in retrovirus vector-mediated gene therapy: teaching an old vector new tricks

Oncoretrovirus-based vectors have been shown to be a safe and reliable vector system that can achieve permanent integration of delivered transgenes. Successful application of these vectors for gene therapy has proven difficult due to their relatively low transduction efficiency; however, cumulative improvements in methodology have recently yielded promising clinical results. Furthermore, significant improvements in basic retrovirus vector technology now promise to revitalize the field. This review focuses on these important recent developments in the field of retrovirus-mediated gene transfer technology and its application to human diseases.

Human cathepsin W, a cysteine protease predominantly expressed in NK cells, is mainly localized in the endoplasmic reticulum

Human cathepsin W (also called lymphopain) is a recently described papain-like cysteine protease of unknown function whose gene expression was found to be restricted to cytotoxic cells. Here we demonstrate that cathepsin W is expressed predominantly in NK cells and, to a lesser extent, in CTLs. Quantitative RT-PCR revealed that NK cells contained approximately 21 times more cathepsin W transcript than CTLs. The predominant expression of cathepsin W in NK cells was further confirmed by Western blot analysis and immunohistochemistry. IL-2-mediated stimulation of NK cells and CTLs revealed a stronger up-regulation of the cathepsin W gene and protein expression in NK cells (7-fold) than in CTLs (2-fold). Transfection experiments of HeLa cells and biochemical analyses revealed that cathepsin W is exclusively "high mannose-type" glycosylated and is mainly targeted to the endoplasmic reticulum (ER). Interestingly, the ER localization of cathepsin W was also found in NK cells, in which colocalization studies revealed an overlapping staining of cathepsin W and Con A, an ER-specific lectin. Furthermore, subcellular fractionation of cathepsin W-expressing cells confirmed the ER localization and showed that cathepsin W is membrane associated. Based on the results of this study, cathepsin W might represent a putative component of the ER-resident proteolytic machinery. The constitutive expression in NK cells and the stronger up-regulation of cathepsin W by IL-2 in NK cells than CTLs suggest that cathepsin W is not just a marker of cytotoxic cells but is, rather, specifically expressed in NK cells.

Synthesis and SAR of 5-, 6-, 7- and 8-aza analogues of 3-aryl-4-hydroxyquinolin-2(1H)-one as NMDA/glycine site antagonists

A series of 5-, 6-, 7- and 8-aza analogues of 3-aryl-4-hydroxyquinolin-2(1H)-one was synthesized and assayed as NMDA/glycine receptor antagonists. The in vitro potency of these antagonists was determined by displacement of the glycine site radioligand [(3)H]5,7-dicholorokynurenic acid ([(3)H]DCKA) in rat brain cortical membranes. Selected compounds were also tested for functional antagonism using electrophysiological assays in Xenopus oocytes expressing cloned NMDA receptor (NR) 1A/2C subunits. Among the 5-, 6-, 7-, and 8-aza-3-aryl-4-hydroxyquinoline-2(1H)-ones investigated, 5-aza-7-chloro-4-hydroxy-3-(3-phenoxyphenyl)quinolin-2-(1H)-one (13i) is the most potent antagonist, having an IC(50) value of 110 nM in [(3)H]DCKA binding and a K(b) of 11 nM in the electrophysiology assay. Compound 13i is also an active anticonvulsant when administered systemically in the mouse maximum electroshock-induced seizure test (ED(50)=2.3mg/kg, IP).

Forest ecosystem development in post-mining landscapes: a case study of the Lusatian lignite district

The restoration of surface mining landscapes requries the (re)creation of ecosystems. In Lusatia (eastern Germany), large-scale open-cast lignite mining operations generated spoil dumps widely consisting of acidified, phytotoxic substrates. Amelioration and rehabilitation measures have been developed and applied to these substrates since the 1950s. However, it is still not clear whether these approaches are sustainable. This paper reports on collaborative research work into the ecological potential of forest ecosystem development on typical minesites in the Lusatian lignite district. At first sight, pine stands on minesites along a chronosequence comprising about 35 years did not show differences when compared with stands on non-mined sites of the general region. Furthermore, with some modification, conceptual models for flora and fauna succession in forest stands on non-mined sites seem to be applicable, at least for the early stages of forest ecosystem development. For example, soil organism abundance and activity at minesites had already reached levels typical of non-mined sites after about 20-30 years. In contrast, mine soils are very different from non-mined soils of the test region. Chemically, mine soil development is dominated by processes originating from pyrite oxidation. Geogenic, i.e. lignitic, soil organic carbon was shown to substitute for some functions of pedogenic soil organic matter. Rooting was hampered but not completely impeded in strongly acidified soil compartments. Roots and mycorrhizae are apparently able to make use of the characteristic heterogeneity of young mine soils. Considering these recent results and the knowledge accumulated during more than 30 years of research on minesite rehabilitation internationally, it can be stated that minesite restoration might be used as an ideal case study for forest ecosystem development starting at "point zero" on "terra nova".

Room-temperature ultraviolet nanowire nanolasers

Room-temperature ultraviolet lasing in semiconductor nanowire arrays has been demonstrated. The self-organized, <0001> oriented zinc oxide nanowires grown on sapphire substrates were synthesized with a simple vapor transport and condensation process. These wide band-gap semiconductor nanowires form natural laser cavities with diameters varying from 20 to 150 nanometers and lengths up to 10 micrometers. Under optical excitation, surface-emitting lasing action was observed at 385 nanometers, with an emission linewidth less than 0.3 nanometer. The chemical flexibility and the one-dimensionality of the nanowires make them ideal miniaturized laser light sources. These short-wavelength nanolasers could have myriad applications, including optical computing, information storage, and microanalysis.

Canine interleukin-5: molecular characterization of the gene and expression of biologically active recombinant protein

Interleukin-5 (IL-5), which is produced primarily by type 2 T helper lymphocytes (Th2), is an eosinophil differentiation and activation factor. Increased numbers of eosinophils in peripherial blood or tissues (eosinophilia) are observed in asthmatic human patients, in animals with helminth infections, and in dogs with allergic diseases. Antagonism of IL-5 activity is being explored as a potential treatment of a number of disease conditions associated with eosinophils in animal models. In order to study the expression and function of this cytokine in the dog, we have isolated and characterized the canine IL-5 gene. The canine IL-5 polypeptide deduced from the cDNA is composed of 134 amino acids that share varying degrees of homology with IL-5 isolated from several mammals. The genomic structure of the canine IL-5 gene consists of four exons and three introns in the coding region, similar to that of the previously characterized human and mouse IL-5 genes. Recombinant canine IL-5 protein, expressed in Pichia pastoris, is biologically active in a cell proliferation assay. Canine IL-5 gene sequences and the biologically active protein described in this study will be useful reagents for future studies of this cytokine in physiologic processes and in pathologic conditions of the dog.

Automated examination notification of emergency department images in a picture archiving and communication system

This study compares the timeliness of radiology interpretation of Emergency Department (ED) imaging examinations in a picture archiving and communication system (PACS) before and after implementation of an automated paging system for notification of image availability. An alphanumeric pager for each radiology subspecialty (chest, pediatrics, bone, neuroradiology, and body) was used to alert the responsible radiologist that an ED imaging examination is available to be viewed on the PACS. The paging system was programmed to trigger off of the PACS database when an image is received on the appropriate radiology display station. The pager message includes the radiology accession number and examination description (such as chest, two-view, or c-spine, etc). The PACS paging tool performance was assessed by calculating the time elapsed, for each ED imaging examination, from the Time Imaged to the Time of Interpretation, where the Time Imaged is the actual image completion time measured at the imaging modality, and the Time Interpreted is the time a radiology interpretation is rendered to the ED, and is measured from the Radiology-to-ED fax time stamp. These measures were analyzed pre- and post-paging system implementation to determine any impact of the automated notification tool on radiology service turnaround time. Results show an improved radiology response time from image completion to interpretation rendered to ED clinicians, down from hour(s) to minutes, with the automated paging examination notification system. Examinations are read by the appropriate radiology specialty section in a more timely fashion, and fewer cases go unread by radiology.

Immunocompetent astrocytes and microglia display major differences in the processing of the invariant chain and in the expression of active cathepsin L and cathepsin S

The role of astrocytes and microglia as antigen-presenting cells in the brain is still controversial. In this study we have analyzed and compared aspects of the molecular machinery that underlies MHC class II trafficking in immunocompetent astrocytes and microglia. We show that IFN-gamma-stimulated microglia possess active cathepsin L and cathepsin S, and efficiently degrade the invariant chain, unlike IFN-gamma-stimulated astrocytes that express cathepsin L but not cathepsin S. The lack of cathepsin S proves to be dramatic for the antigen-presentation capacity of astrocytes, which is nearly abolished when these cells are stimulated by a combination of IFN-gamma and TNF-alpha. TNF-alpha indeed decreases cathepsin L activity as we show here, leading to alterations in invariant chain processing, and hence in MHC class II trafficking in astrocytes. Cystatin C inhibits cathepsin L activity in astrocytes, but does not regulate cathepsin L and cathepsin S activity in microglia. We therefore identify cathepsin L and cathepsin S as key components in the regulation of the immune potential of astrocytes and microglia, and provide evidence for a cell-specific regulation exerted by IFN-gamma and TNF-alpha on the expression and activity of cathepsins.

Active therapy for chronic low back pain: part 2. Effects on paraspinal muscle cross-sectional area, fiber type size, and distribution

DESIGN

Randomized prospective study to compare the effects of three types of active therapy on the back muscle structure of chronic low back pain patients.

OBJECTIVES

To analyze the effects of 3 months active therapy on gross back muscle size and muscle fiber type characteristics and their relationship to changes in muscle function.

SUMMARY OF BACKGROUND DATA

Many studies have documented a diminished muscular performance capacity in cLBP patients, but few have supported this with evidence of alterations in either the macro- or microscopic structure of the paraspinal muscles. Investigations of the changes in muscle structure following active rehabilitation are even rarer.

METHODS

Assessments of trunk muscle cross-sectional area (using MRI), erector spinae fiber size/type distribution and pathology (percutaneous biopsy), and muscle function (see Part 1) were made in a group of 59 individuals with cLBP, who were participating in a randomized trial of active therapies for cLBP (physiotherapy, muscle training on devices, aerobics).

RESULTS

Fifty-three out of 59 patients (90%) completed the therapy. At baseline, significant correlations were observed between the size of the paraspinal muscles and isometric back extension strength (P=0.0001), and between the proportional area of the muscle occupied by each fiber type and the fatigability of the muscle (P=0.012). Following therapy, there were small (few percent) increases in trunk muscle size in the aerobics and physiotherapy groups and a similarly slight decrease in the devices group. Changes in erector spine size correlated only weakly and nonsignificantly with changes in back extension strength. There were no major changes in fiber type proportion or fiber size in any group following therapy.

CONCLUSION

Three months active therapy is not sufficient to reverse the typical "glycolytic" profile of the muscles of cLBP patients or to effect major changes in backmuscle size. The alterations in muscle performance observed (increased strength and endurance; Part 1) werenot explainable on the basis of structural changes within the muscle.

[Review of infected total arthroplasties of the hip and knee--apropos of 28 cases]

This study is a long-term analysis of a group of patients with infected arthroplasties of the hip or the knee. We identified 28 patients with an infected arthroplasty (22 hips, 6 knees) documented by bacterial culture or on direct examination. At the time of diagnosis and on follow-up (a mean of 46 months after treatment) we evaluated the clinical picture, the radiological appearances of the articulation and the biological parameters. 19/28 patients showed a typical clinical picture, whereas in 9 others the picture was more doubtful. The treatments were 14 two-stage replacements of the arthroplasties, 7 simple resections, 5 conservative treatments and 2 one-stage replacements. On follow-up, 25 patients were considered as cured of their infection and 3 as failures. From a functional viewpoint, 9 patients showed no limitation, whereas 19 were limited in the daily activity. Half of the patients had no pain. Radiology showed that 20/26 evaluated patients had no signs of recurrence. Paraclinical examinations are important in the diagnosis of persistent low grade infections, particularly the demonstration of bacteria by pre-surgical sampling (fine needle aspiration, culture from draining sinuses). In spite of the cure of infection, the functional and painful sequellae are often considerable. As a result of our experience, we recommend a two-stage surgical procedure. Only when the general condition of the patient is poor, or when the infection is not under control, would we envisage an alternative procedure (arthrodesis, girdelstone, conservative).

Activity, expression, and transcription rate of the cathepsins B, D, H, and L in cutaneous malignant melanoma

BACKGROUND

Increased activity of the protease cathepsin B has been demonstrated in many tumor cells. A correlation of cathepsin B activity and metastatic potential of melanoma has been well established.

METHODS

The cathepsins B, D, H, and L were evaluated in normal skin, nevi, and melanoma samples to obtain information about their role and their regulation in melanoma. The authors localized specific proteolytic activity with histochemistry, cathepsin protein immunohistochemistry, and mRNA with in situ hybridization.

RESULTS

Activities and immunoreactivities of the cathepsins B and L were found to be increased in all melanocytic lesions. However, the staining for the corresponding mRNA levels was elevated only in melanomas. Cathepsin D protein and mRNA were expressed to a higher degree only in the dysplastic nevus and in melanomas. The increase was due to tumor cells and cells of the surrounding tissue. Cathepsin H activity, immunoreactivity, and mRNA appeared to be correlated inversely with the invasive potential of the lesion.

CONCLUSIONS

It may be relevant for the malignant potential of the lesion whether the increase in activity is accompanied by an increase in the mRNA level. Two different mechanisms-the existence of different mRNAs and the higher transcription rate of the cathepsin gene-have been proposed for the regulation of cathepsin B activity in tumor cells. The current data suggest that, depending on the thickness of the melanoma, cathepsin activity is regulated by different mechanisms. The up-regulation of cathepsin gene transcription appears to be characteristic for more invasive tumor cells.

Cathepsin K expression in human lung

Tissue remodeling is crucial in different lung diseases, in the embryonal development as well as in bronchial carcinoma. Cathepsins were proposed to be involved in the degradation of matrix proteins. Cathepsin K is one of the most potent matrix-degrading cysteine proteinases known as yet. The elastinolytic and collagenolytic activity of this papain-like protease is comparable with that of neutrophil elastase. We have investigated the cathepsin K expression in normal adult lung tissues, in embryonal lung tissue and in bronchial carcinoma. With help of specific anti-cathepsin K antibodies it could be shown that cathepsin K was expressed in bronchial epithelial cells. These data could be confirmed at mRNA level using a quantitative RT-PCR as well as by visualisation of the specific enzymatic activity in epithelial cell lines. During the embryonal development cathepsin K was expressed in the epithelial cells of the developing bronchi. The expression seemed to be upregulated in parallel with the development of the bronchial and alveolar lumen. In the later phase of lung development the cathepsin K expression was restricted to bronchial epithelial cells. Furthermore, using quantitative RT-PCR it could be shown that cathepsin K-mRNA was upregulated in lung tumor tissues in comparison to normal tissues from the same patients. These data suggest that cathepsin K may play an important role in matrix remodeling of the lung under physiological and pathological conditions.

A cystatin-based affinity procedure for the isolation and analysis of papain-like cysteine proteinases from tissue extracts

Cysteine-proteinases (CP) of the papain family can be affinity-adsorbed by egg white cystatin C coupled to Sepharose 4B, thus allowing their selective isolation from either tissue or cultured cell extracts as well as biolological fluids and culture media. CP complexed by immobilized cystatin are further analyzed by means of SDS-PAGE and Western blot followed by serial or parallel immunological detection. The single-step affinity adsorption of papain-like enzymes has the advantage, over immunoprecipitation techniques, of yielding the simultaneous and comprehensive picture of most CP, as both precursor and mature forms, in a given sample. Moreover, cell extraction in the presence of immobilized cystatin ensures a fast complexation of CP, avoiding artifacts, due to conversion, degradation, and, eventually, subtraction of constitutive enzymes from the sample because of their interactions with endogenous inhibitors. This will provide a pattern that might reflect more closely the real CP levels in intact cells. The method may be useful in the field of biochemistry, cell biology, and, possibly, clinical chemistry to perform rapid analyses of papain-like enzymes and to monitor changes in both cellular and extracellular CP profiles along with different physiopathological conditions.

Characterization and cloning of a major high molecular weight house dust mite allergen (Der f 15) for dogs

Although house dust mites (HDM(s)) are important elicitors of canine allergy, the low molecular weight molecules defined as major allergens for humans do not appear to be major allergens for dogs. Western blotting of Dermatophagoides farinae (D. farinae) extracts with sera from sensitized dogs showed that the majority of animals had IgE antibodies specific for two proteins of apparent molecular weights of 98 and 109kDa (98/109kDa). The N-terminal sequences of these two proteins were identical, suggesting they were very closely related, and sequencing of internal peptides showed the protein(s) to have homology with insect chitinases. A purified preparation of 98/109kDa proteins elicited positive intradermal skin tests (IDST(s)) in a group of well-characterized atopic dogs sensitized to D. farinae, but not in normal dogs. A rabbit polyclonal antiserum raised against the purified proteins was used to immunoscreen a D. farinae cDNA library. The mature coding region of the isolated chitinase cDNA predicts a protein of 63.2kDa; sequence analysis and glycan detection blotting suggest that the molecule is extensively O-glycosylated. Monoclonal antibodies made against the purified native protein were used to localize the chitinase in sections of whole D. farinae mites. The protein displayed an intracellular distribution in the proventriculus and intestine of the mite, suggesting that it has a digestive, rather than a moulting-related, function. The high prevalence of IgE antibodies to this antigen in canine atopic dermatitis makes it a major HDM allergen for dogs, and the protein has been formally designated Der f 15.

Design and synthesis of rhodamine 110 derivative and caspase-3 substrate for enzyme and cell-based fluorescent assay

N-Octyloxycarbonyl-R110 (1), with enhanced cell penetration and retention properties, was prepared from rhodamine 110. The tetrapeptide substrate N-Ac-DEVD-N'-octyloxycarbonyl-R110 (3) was prepared and shown to be efficiently cleaved by human recombinant caspase-3 and by apoptotic HL-60 cells. This substrate should prove useful in cell-based assays for apoptosis inducers and inhibitors.

IL-1 beta- and IL-4-induced down-regulation of autotaxin mRNA and PC-1 in fibroblast-like synoviocytes of patients with rheumatoid arthritis (RA)

Autotaxin (ATX) is a 125-kD ectonucleotide pyrophosphate/phosphodiesterase, which was initially isolated and cloned from human melanoma cells as a potent stimulator of tumour cell motility. ATX shows 44% identity to the plasma cell membrane marker PC-1. Recently, we described the decreased expression of ATX mRNA in cultured fibroblast-like synoviocytes (SFC) of patients with RA by interferon-gamma. In this study using a competitive reverse transcriptase-polymerase chain reaction, we show an increased ATX mRNA expression in SFC from patients with RA in comparison with synoviocytes from non-RA patients. The median ATX mRNA amount in SFC of RA patients (440 pg/microg total RNA) was five-fold higher than the expression in synoviocytes from non-RA patients (80 pg/microg total RNA) or foreskin fibroblasts (MRHF cells, 90 pg/microg total RNA). In contrast to the elevated ATX mRNA expression in SFC of patients with RA, we did not measure increased mRNA amounts of PC-1 in these cells. Both the ATX mRNA amount and the 5'-nucleotide phosphodiesterase (PDE) activity of SFC lysate were reduced after treatment of SFC with the cytokines IL-1beta or IL-4. IL-1beta and IL-4 induced a down-regulation of PC-1 mRNA and protein expression in SFC. In SFC treated with transforming growth factor-beta the expression of PC-1 mRNA and protein was increased, whereas no significant effect on ATX mRNA expression was detectable. Pharmacological drugs used in therapy for RA, such as dexamethasone, cyclosporin, methotrexate and indomethacin, did not show a statistically significant effect on either ATX mRNA or PC-1 mRNA expression. Only pentoxifylline suppressed ATX mRNA as well as PC-1 mRNA expression. In conclusion, we show a tight regulation of ATX and PC-1 gene expression by cytokines detectable in the inflamed tissue of RA. Further investigations will deal with the regulation of ATX protein expression as well as with the function of ATX in RA.

Specific adhesion molecules bind anchoring filaments and endothelial cells in human skin initial lymphatics

Anchoring filaments are a characteristic feature of initial lymphatic vessels. They connect the abluminal membrane of endothelial cells to the surrounding elastic fibers. The main molecular component of anchoring filaments is fibrillin. Initial lymphatic vessels of human skin were stained with monoclonal antibodies to fibrillin, integrins alpha 2 beta 1, alpha 3 beta 1 and alpha v beta 3, vinculin, talin, beta-actin and focal adhesion kinase (FAK). A double-labeling immunofluorescence method was used to simultaneously stain fibrillin and alpha 3 beta 1 integrin or FAK. Close contiguities between integrins and anchoring filaments were observed. These results suggest that the anchoring filaments connect the extracellular matrix and the endothelial cell cytoskeleton through the transmembrane integrin and FAK molecule. The results also demonstrate the presence of focal adhesions in the wall of initial lymphatic vessels. These connections possibly enable transmission of chemical and/or mechanical stimuli from the extracellular matrix to the endothelial cells. Here, they are transformed in cytoskeleton rearrangements and intracellular signaling events, some of which may contribute to the initial formation of lymph.

The expression of surface markers on dendritic cells as indicators for the sensitizing potential of chemicals

Novel approaches to testing of skin sensitizing chemicals have made use of immature dendritic cells (DCs) cultured from different hematopoietic progenitors. These cells resemble Langerhans cells (LCs), which are the most potent antigen presenting cells in the skin. Former research has focused on the phenotypic and functional changes of LCs after application of skin sensitizers. But it has proven difficult to isolate sufficient numbers of LCs from skin. This disadvantage is overcome by cultures of immature DCs providing high numbers of reactive cells. The aim of the present investigation was to test the response of DC cultures established from different blood donors to known sensitizers, an irritant and a vehicle. The sensitizers NiSO(4), dinitrochlorobenzene (DNCB), 2,4,6 trinitrobenzene sulfonic acid (TNBS), alpha-hexylcinnamaldehyde (Cinn) and eugenol (Eu) induced the up-regulation of the co-stimulatory molecule CD86, of intercellular adhesion molecule CD54 and of the HLA-DR antigen. The irritant sodium dodecyl sulfate (SDS) and the vehicle dimethyl sulfoxide (DMSO) had no effect. A high rate of responders within blood donors was found for NiSO(4), TNBS, Cinn and Eu, while DNCB was less effective. The augmentation of surface marker expression in dendritic cells obtained from peripheral human blood seems to be a promising readout in prescreening for strong and moderate sensitizers. This test could thus help to reduce animal numbers for in vivo testing.

A novel monoclonal antibody specific for lymphatic endothelium

The difficulty of identifying and differentiating lymphatic and blood microvessels in tissue sections can be overcome by a monoclonal antibody specific for lymphatic endothelium. Unfortunately, the only known antibody also reacts with the endothelium of some blood vessels. The technique of double immunization (passive, with an antiserum to blood endothelium, and active, with a suspension of lymphatic endothelial cells) was, therefore, used to increase the chances of recognizing specific lymphatic antigens by the mouse immune system. The monoclonal antibody obtained, LyMAb, a G1 immunoglobulin, reacted strongly with the endothelium of bovine thoracic duct, mesenteric collecting vessels and lymphatic vessels of gallbladder and lymph nodes and moderately with those of the intestinal wall. Blood vessels (intercostal arteries, azygos vein and blood microvessels of all organs tested) were consistently negative. The antibody was species-specific and did not react with formalin-fixed, paraffin-embedded sections. Cross-reactivity was limited to some connective tissue fibres and scattered cells in the lymph node parenchyma, intestinal villi and hepatic lobules.

The incidence of transient neurological symptoms after spinal anaesthesia with lidocaine compared to prilocaine

The purpose of this double-blind study was to investigate the incidence of transient neurological symptoms after the use of isobaric lidocaine and isobaric prilocaine for spinal anaesthesia. Seventy patients (ASA 1-2, age between 18 and 70 years) were randomly assigned to two groups of 35 patients each, to receive either isobaric 2% lidocaine 4 ml or isobaric 2% prilocaine 4 ml intrathecally, at the L3-4 interspace. One patient in the prilocaine group could not be included because data were incomplete. On the first postoperative day, patients were evaluated for transient neurological symptoms. Pain was scored on a 10-point scale. Seven patients (20%) in the lidocaine group had transient neurological symptoms with a mean pain score of 5.3, whereas no patient in the prilocaine group had these complaints (p = 0.006). Symptoms disappeared within 4 days. Prilocaine results in a lower incidence of transient neurological symptoms than lidocaine intrathecally and therefore it is more suitable for short surgical procedures.

Weight change in older depressed patients during acute pharmacotherapy with paroxetine and nortriptyline: a double-blind randomized trial

The authors examined weight change in 32 elderly patients treated for 12 weeks with either nortriptyline or paroxetine during acute-phase pharmacotherapy. Random assignment to treatment and double-blind assessment of weight change were performed, including ascertainment of premorbid (i.e., pre-depression) weight. Pretreatment severity of depression was correlated with weight loss during the depressive episode and depression-related weight loss, in turn, correlated with weight regained during antidepressant treatment. There was no differential weight change associated with nortriptyline vs. paroxetine. Rather, subjects in both groups approximated their premorbid weights by 12 weeks of acute-phase pharmacotherapy with either agent. However, additional investigation of weight change during continuation and maintenance pharmacotherapy is necessary and would be clinically useful for the long-term management of elderly patients with depression.

Occupational exposure to static, ELF, VF and VLF magnetic fields and immune parameters

Despite the important role of the immune system in defending the body against infections and cancer, very few investigations have been undertaken to study possible effects of electromagnetic fields on human immunity. The aim of the present study was to examine the effect of occupational exposure on hospital personnel operating magnetic resonance tomographs and on industrial workers at induction heaters. In both categories of workplaces, magnetic flux densities exceeding Austrian exposure standards have been registered. Because of the complexity and high redundancy of the immune system, an extensive range of assay systems was applied: relative and absolute numbers of lymphocytic subsets were counted, the proliferative activity of T and B cells determined, the production of interleukin 2, interferon gamma and tumour necrosis factor alpha analysed, serum immunoglobulins evaluated, as well as non-specific immunity of monocytes and granulocytes measured by their oxidative burst. The number of natural killer cells and oxidative burst in monocytes showed statistically significant differences in workers at induction heaters and controls. The observed effect on oxidative burst was counteracted by a higher number of active cells in the exposed group, indicating normal non-specific immunity. The high number of natural killer cells, observed in some of the study subjects working at induction heaters, was reconfirmed in another investigation and deserves a further follow-up.

Highly potent inhibitors of human cathepsin L identified by screening combinatorial pentapeptide amide collections

By screening a combinatorial pentapeptide amide collection in an inhibition assay, we systematically evaluated the potential of 19 proteinogenic amino acids and seven nonproteinogenic amino acids to serve as building blocks for inhibitors of human cathepsin L. Particularly efficient were aromatic, bulky, hydrophobic amino-acid residues, especially leucine, and positively charged residues, especially arginine. Building blocks for potential inhibitory peptides were combined by random selection from their activity pattern. This random approach for the design of inhibitors was introduced to compensate for the inaccuracy induced by shifted docking of combinatorial compound collections at the active center of cathepsin L. Thereby, we obtained structurally defined pentapeptide amides which inhibited human cathepsin L at nanomolar concentrations. Among the most potent novel inhibitors, one peptide, RKLLW-NH2, shares the amphiphilic character of the nonamer fragment VMNGLQNRK of the autoinhibitory, substrate-like, but reverse-binding prosegment of human cathepsin L which blocks the active center of the enzyme. Obviously, RKLLW-NH2 carries the functions that are important for enzyme-peptide interaction in a condensed form. This hypothesis was confirmed by structure-activity studies using truncated and modified pentapeptides.

Influence of age and duration of symptoms on fibre type distribution and size of the back muscles in chronic low back pain patients

Many studies have documented an association between chronic low back pain (LBP) and deficits in back muscle strength and endurance. The sub-optimal performance is believed to be the result of alterations in the size and structure of the muscle, although the long-standing issue of whether the observed changes precede or are a consequence of the pain remains unresolved. If consequent to the problem, and predominantly related to disuse of the muscles, then it may be expected that a relationship between muscle structure and symptom duration would exist. Lumbar paraspinal muscle samples were obtained from 59 chronic LBP patients using the percutaneous biopsy technique. The samples were subject to routine histochemical analysis for the examination of muscle fibre type characteristics and cytochemical architectural changes. In 55 of the patients, the gross cross-sectional areas of magnetic resonance images of the trunk muscles were also measured. Multivariate analysis showed that symptom duration was the strongest predictor of the individual proportions of the fast-fatigable type IIX fibres; with age and gender included in the model, nearly 30% of the variance in fibre type distribution could be accounted for. Duration of pain had no influence on fibre size. Gross muscle cross-sectional area correlated directly with lean body mass and inversely with age, but showed no relationship with symptom duration. Pathological changes in the internal fibre structure were more frequently encountered in older patients, and were independent of symptom duration. The results suggest that, over the long term, fibre type transformations rather than alterations in fibre size are the predominant changes to be found in the muscles of chronic LBP patients. The direction of change supports the results of many previous studies that have demonstrated corresponding differences in the fatigability of the muscles. There is a strong case for the early implementation of active measures to attempt to offset the development of these changes in back pain patients.

[Severe cardiac insufficiency and type Ib pseudohypoparathyroidism]

The authors report the case of a 28 year old woman with acute left ventricular failure associated with severe hypocalcaemia (1.7 mmol/l) without chronic renal failure or hypoproteinaemia. The echocardiographic appearances were those of dilated and globally hypokinetic cardiomyopathy with a severely depressed left ventricular ejection fraction (23%). Haemodynamic improvement was only obtained by the association of calcium supplements and Vitamin D derivatives (Un-Alfa) to conventional treatment. A low serum calcium associated with hyperphosphotaemia, hypocalciuria, hypophosphaturia and, above all, a high parathormone concentration, provided the diagnosis of a sporadic form of type Ib pseudohypoparathyroidism. Secondary cardiac failure to the hypocalcaemia is mainly observed in children and young adults in the context of chronic renal failure or true hypoparathyroidism. Pseudohypoparathyroidism is a very rare condition and systolic LV dysfunction for which hypocalcaemia is responsible, would seem to be totally reversible after calcium supplementation.

An evolutionarily conserved tripartite tryptophan motif stabilizes the prodomains of cathepsin L-like cysteine proteases

Cathepsin L-like cysteine proteinases contain an evolutionarily highly conserved alpha-helical motif in the proregion. This is called the ER(F/W)N(I/V)N motif according to the conserved amino acids along one side of the helix. We studied the function of this motif using site-directed mutagenesis experiments of human procathepsin S. We replaced each of these amino acids with alanine and constructed deletion mutants lacking parts of the helix. All mutants were expressed in HEK 293 cells, but only one, W52A, was not processed to mature cathepsin S, nor was it phosphorylated or secreted into the culture medium. W52 is part of the hydrophobic core in the propeptide region of cathepsin S comprising two additional tryptophan residues, W28 and W31, also conserved among cathepsin L-like cysteine peptidases. Replacement of the latter with alanine led to consequences similar to those with the W52A mutation. Recombinant propeptides containing mutations of one of the three tryptophan residues were three orders of magnitude less effective as inhibitors of mature cathepsin S than the wild-type propeptide. The results point to a dominant role of the respective hydrophobic stack in the proper folding, transport and maturation of procathepsin S and related cathepsin L-like cysteine proteinases.

Identification, cloning, and characterization of a major cat flea salivary allergen (Cte f 1)

An 18 kDa protein isolated from saliva of the cat flea, Ctenocephalides felis, elicits a positive intradermal skin test (IDST) in 100 and 80% of experimental and clinical flea allergic dogs, respectively. Using solid-phase enzyme-linked immuno assay (ELISA), this protein detected IgE in 100 and 80% of experimental and clinical flea allergic dogs, respectively. A cDNA (pFSI) encoding a full-length Cte f 1 protein was isolated from a C. felis salivary gland cDNA library, using a combination of PCR and hybridization screening. This cDNA is 658 bp in length, and contains an open reading frame of 528 bp. The open reading frame encodes a protein of 176 amino acids, consisting of an 18 amino acid signal sequence and a 158 amino acid mature protein. The calculated molecular weight and pI of the mature protein are 18106 Da and 9.3, respectively. The protein, named Cte f 1, is the first novel major allergen described for canine flea allergy. Recombinant Cte f 1 (rCte f 1) was expressed in Escherichia coli, Pichia pastoris and baculovirus infected Trichoplusia ni cells. Approximately, 90% of the rCte f 1 expressed in E. coli accumulated in insoluble inclusion bodies, which could be refolded to a soluble mixture of disulfide isomers with partial IgE binding activity. Small quantities of an apparently correctly refolded form of rCte f 1, which had IgE binding activity equal to the native antigen, was isolated from the soluble fraction of E. coli cells. However, P. pastoris and baculovirus infected insect cells expressed and secreted a fully processed, correctly refolded and fully active form of rCte f 1. Mass spectrometry analysis of the active forms of rCte f 1confirmed that eight intact disulfide bonds were present, matching the number observed in the native allergen. The relative ability of rCte f 1 to bind IgE in the serum of flea allergic animals, produced in these three expression systems, matched that of the native allergen. Competition ELISA demonstrated that approximately 90% of the specific IgE binding to native Cte f 1 could be blocked by the different forms of rCte f 1.

Teased-fiber technique for peripheral myelinated nerves: methodology and interpretation

Teased-fiber technique is the best approach for studying peripheral myelinated nerve fibers in their continuity. It enables the assessment of size of myelin segments formed by Schwann cells and characterization of pathologic changes affecting the internodia, the paranodal regions, and the invested axons. Fiber teasing is performed on prestained proximodistally oriented portions of peripheral nerves. Specimens about 10 mm long are stained for 24-48 hours in Sudan black and then transferred to glycerin, where, using a pair of fine forceps and a stereomicroscope, they are separated into smaller fiber bundles from which single fibers are isolated. The work is performed on a glass slide with an adhesive surface (albuminized or "superfrost"), on which the fibers are placed in strict proximodistal orientation. Following drying in an oven, the slides are mounted with glycerin-gelatine (same as used for frozen sections). The changes, when present, can usually be recognized during the preparation, but fibers are reexamined and changes confirmed in mounted slides. Photographic reconstruction of the fibers facilitates their assessment and enables the documentation of findings. The teased-fiber technique is auxiliary to histopathology, and to limit the workload and save costs, it can be performed on only a few specimens selected for better characterization of changes recognized or suspected in tissue sections. In particular, segmental demyelination and early stages of Wallerian or secondary axonal degeneration can be recognized in teased fibers. Segmental demyelination is characterized by loss of fully myelinated segments and their replacement by newly formed short and thin segments, remyelinating the preserved axon. The early stage of secondary axonal degeneration is recognized by formation of ovoidal fiber fragments in the midinternodal region.

A new organic nanoporous architecture: dumb-bell-shaped molecules with guests in parallel channels

A new type of dumb-bell-shaped host molecule (6-8) has been synthesised, of which 1,8-bis((1)-adamantyl)-1,3,5,7-octatetrayne (8 = BAOT) forms an open porous architecture when cocrystallised with a number of typical solvent molecules. Adamantyl substituents attached to a tetraalkyne spacer build up the walls of parallel channels wherein guest molecules are aligned. Surprisingly, the tetraalkyne unit is significantly bent. Desolvation experiments provide evidence for a reversible inclusion of guests. In the case of the inclusion of 2-butanone, a partial substitution by symmetrical and asymmetrical long-chain chromophores during crystallisation was possible. Stained crystals showed optical frequency doubling. The crystal structure analysis revealed a centric space group, although considerable translational and orientational disorder was present. Application of scanning pyroelectric microscopy revealed that the growth of inclusion compounds with 2-butanone produced polar ordering of guest molecules, which were aligned in two macro-domains of opposing polarity. The resulting orientation of the carbonyl dipoles is in agreement with the theoretical prediction of a Markov model of spontaneous polarity formation based on molecular recognition processes on growing crystal faces. The present case represents a new example of a property-driven supramolecular synthesis.

Effects of ACEA-1328, a NMDA receptor/glycine site antagonist, on U50,488H-induced antinociception and tolerance

Previously, we have shown that inhibition of the glycine site associated with the N-methyl-D-aspartate (NMDA) receptor is another viable approach to blocking morphine tolerance. In the present study, we sought to investigate the involvement of the NMDA receptor/glycine site in kappa-opioid receptor-mediated antinociception and tolerance in CD-1 mice. In antinociception studies, mice were injected with 5-nitro-6,7-dimethyl-1,4-dihydro-2, 3-quinoxalinedione (ACEA-1328), a systemically bioavailable NMDA receptor/glycine site antagonist, or the vehicle (Bis-Tris, 0.2 M) and then immediately with trans-(+/-)-3, 4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl)-cyclohexyl]-benzeneacetamid e methanesulfonate (U50,488H), a kappa-opioid receptor agonist. Thirty minutes later, mice were tested for changes in nociceptive responses in the tail flick assay. ACEA-1328, per se, prolonged tail flick latencies with an ED(50) of approximately 50 mg/kg. Concurrent administration of ACEA-1328, at doses that did not produce antinociception, with U50,488H increased the potency of U50,488H in a dose-dependent manner. In tolerance studies, mice were treated, either once a day for 9 days or twice daily for 4 days, with the vehicle or ACEA-1328. Immediately after the initial injection, mice then received an injection of saline or U50,488H. On the test day, mice were injected with U50,488H alone and tested for antinociception 30 min later. Chronic treatment with U50,488H by either method produced tolerance. Unlike the acute effect of the drug, chronic treatment with ACEA-1328 decreased the antinociceptive potency of U50,488H. Taken together, the data suggest that acute and chronic administration of ACEA-1328 differentially affected the antinociceptive effect of U50,488H. Furthermore, the decreased in the potency of U50,488H induced by chronic treatment with ACEA-1328 also confounded the interpretation of the tolerance data.

Selbstinstruktionstraining bei visuellem Neglect - Eine einzelfallanalytische Untersuchung

Zusammenfassung: Patienten mit Neglect sollten sich bei Aufgaben aus dem Bereich der Neglectdiagnostik mit einer Selbstverbalisationstechnik dazu anleiten, die vernachlässigte linke Seite zu beachten. Das methodische Vorgehen sah eine Einzelfallanalyse mit direkter Replikation vor. Pro Person wurden 25 Sitzungen absolviert. Dem Problem der Mehrfachvorgabe von Aufgaben, das sich bei einer Einzelfallanalyse stellt, wurde begegnet, indem Parallelversionen der Testmaterialien erstellt wurden. Das Selbstinstruktionstraining reduzierte die neglecttypischen Fehler signifikant. Die Hypothese, daß die eingeführte Behandlung eine Besserung der Symptomatik bedingt, konnte sich zudem in einer Replikationsstudie bewähren. Offen bleibt, ob die Selbstinstruktionen der Patienten spezifisch auf einen Verhaltensbereich wirkten oder aber auf andere generalisierten.

ACEA-1328, a NMDA receptor/glycine site antagonist, acutely potentiates antinociception and chronically attenuates tolerance induced by morphine

The effect of ACEA-1328, a competitive and systemically bioavailable NMDA receptor/glycine site antagonist, was studied on morphine-induced antinociception and tolerance in CD-1 mice using the tail flick test. To study the effect of acute administration of ACEA-1328 on morphine-induced antinociception, mice were injected with either ACEA-1328 (1, 5, and 10 mg kg(-1)) or Bis-Tris (0.2 m) immediately followed by an injection of morphine and tested for antinociception 30 min later. ACEA-1328 significantly increased the antinociceptive potency of morphine. To study the effect of chronic administration of ACEA-1328 on morphine-induced antinociception and tolerance, mice were treated, either once per day for 9 days or twice daily for 4 days, with ACEA-1328 or with the vehicle. Mice were then, within 1 min, injected daily with either morphine or saline. On the day of the test, mice were injected with only morphine and tested for antinociception 30 min later. In comparison to the acute effect of ACEA-1328, chronic treatment with the NMDA receptor/glycine site antagonist did not affect the antinociceptive potency of morphine. Chronic treatment with morphine, by both methods, produced a significant degree of tolerance. Concurrent administration of ACEA-1328 with the opioid analgesic completely blocked morphine tolerance. Our results demonstrate that acute, but not chronic, treatment with ACEA-1328 increased the antinociceptive potency of morphine. Furthermore, co-administration of the NMDA receptor antagonist with morphine abolished the development of tolerance. Overall, the data support a growing body of evidence showing that activation of the NMDA receptor plays a functional role in opioid-induced antinociception and tolerance.

Lymphatic vessels of the human heart: precollectors and collecting vessels. A morpho-structural study

Only topographic and distributional data are available on the lymphatic outflow vessels of the human heart. Here we describe their structural and ultrastructural features. Fragments of the atria, ventricles and fat surrounding the major coronary branches were obtained from hearts of dilated cardiomyopathy patients. Serial semithin sections were observed under light microscopy and used for tridimensional reconstructions. Ultrathin sections were observed by transmission electron microscopy. Precollectors, the initial lymphatic outflow routes of the heart, are small valved vessels with irregular, discontinuous musculature. They originate in the subepicardial region from a network of epicardial, and from scattered myocardial absorbing lymphatic vessels and drain into the collecting vessels accompanying the major coronary branches. Collecting vessels are larger but structurally similar to precollectors. Wall musculature is independent of the size of the vessel. Their ultrastructure is the same as that of precollectors. Endothelial cells have many Weibel-Palade bodies, cytoplasmic filaments and focal adhesions. The basement membrane is discontinuous and anchoring filaments are frequent and conspicuous. The subendothelial layer contains much elastin. Human heart collecting vessels and precollectors may only be distinguished by their size. The scarcity of musculature suggests that lymph progression in this district is mainly ensured by cardiac revolutions. Their ultrastructural features are determined by adaptation to dynamic forces. The architecture of these vessels (random, disorderly, discontinuous, lacking any exact plan) and their large variations in caliber are in line with the ontogenetic hypothesis that peripheral lymphatic vessels originate from the coalescence of mesenchymal lacunae.

Extraesophageal autonomic dysfunction in patients with achalasia

A disagreement exists as to whether extraintestinal parasympathetic autonomic function is altered in patients with esophageal achalasia. Therefore, we assessed autonomic dysfunction in esophageal achalasia and considered the most relevant parameters of parasympathetic autonomic function in these patients. In a prospective study, heart rate variation and pupillary function were investigated in 15 patients with achalasia of the esophagus and in 15 controls by application of a battery of standardized autonomic function tests. Significant differences between patients and controls were detected for various parameters of heart rate variation and pupillometry. When compared to values obtained from large groups of healthy subjects, none of the controls but 11 patients had at least one abnormal parameter of parasympathetic autonomic function. It is suggested that in esophageal achalasia parasympathetic dysfunction that extends beyond the gastrointestinal tract can be frequently detected. This finding supports the view of a generalized alteration of the autonomic nervous system in achalasia.

The retinoblastoma tumor suppressor inhibits cellular proliferation through two distinct mechanisms: inhibition of cell cycle progression and induction of cell death

Studies aimed at examining the precise function(s) of the retinoblastoma tumor suppressor protein, RB, have been hindered by the rapid phosphorylation and inactivation of ectopically expressed RB which occurs in the majority of cell types. Therefore, ectopically expressed RB is a poor inhibitor of cellular proliferation. We have designed constitutively active RB proteins, PSM-RB, that cannot be inactivated by phosphorylation. Using these proteins, we show that unlike wild-type RB, PSM-RB proteins inhibit cell cycle progression in a broad range of tumor cell types. Furthermore, unlike p16ink4a, PSM-RB is also a potent inhibitor of cell cycle progression in RB-deficient tumor cells. Surprisingly, we identified a tumor cell line that is resistant to the cell cycle inhibitory effects of PSM-RB. This finding challenges the hypothesis that RB must be inactivated in all cells for cell cycle progression to occur. Further characterization of this 'resistant' tumor line revealed that proliferation of these cells is still inhibited by PSM-RB. We show that this is due to PSM-RB-induced cell death. As such, these studies are the first to show that RB inhibits cellular proliferation through at least two distinct mechanisms - inhibition of cell cycle progression and induction of cell death.

Germination and growth responses of hybridizing Carpobrotus species (Aizoaceae) from coastal California to soil salinity

Germination, growth, and physiological responses of hybridizing Carpobrotus from coastal California to soil salinity were studied. Hybrids are presumably the result of hybridization and introgression between the exotic Carpobrotus edulis, a succulent perennial invading coastal habitats, and the native or long-naturalized C. chilensis. Germination responses were investigated at 0, 10, 20, and 50% seawater. Seedling growth and physiology were compared by irrigating seedlings with solutions of the same seawater concentrations and in low and high nutrients. Germination was inhibited in the presence of salt, but recovered after transferring the seeds to fresh water. Seeds exposed to salt had higher final germination rates than control. Growth of Carpobrotus was slightly enhanced by low seawater concentrations but reduced at high salinity at both nutrient regimes. Leaf cell sap osmolarity increased with increasing soil salinity, and taxa did not differ significantly in this physiological adjustment. Leaf carbon isotope ratios (∂(13)C) ranged from -28 to -22‰ and became less negative at higher salinities, indicating an improved water use efficiency in the seedlings at high salt concentrations. In addition, ∂(13)C values were generally less negative at high than at low nutrients. Differences among taxa were generally small. The results show that salinity affects both establishment and growth of hybridizing Carpobrotus. The overall weak species differences in salt tolerance indicate that the exotic C. edulis can occupy the same sites as C. chilensis in terms of salinity. The similarity of hybrids in their response to salinity suggests that they may contribute to the invasion by Carpobrotus.

Structure-activity relationship of N-(phenylalkyl)cinnamides as novel NR2B subtype-selective NMDA receptor antagonists

A novel series of N-(phenylalkyl)cinnamides related to N-(4-phenylbutyl)-3,4-dihydroxy-beta-cyanocinnamide (6, an EGFR-K inhibitor with high antiproliferative activity) was synthesized and tested for antagonism at N-methyl-D-aspartate (NMDA) receptor subtypes. Potency and subunit selectivity were assayed by electrical recordings in Xenopus oocytes expressing three binary combinations of cloned rat NMDA receptor subunits: NR1A expressed in combination with either NR2A, NR2B, or NR2C. The N-(phenylalkyl)cinnamides are selective antagonists of NR1A/2B receptors. Assayed under steady-state conditions, N-(4-phenylbutyl)-4-hydroxycinnamide (16) has an IC(50) value of 77 nM and >1000-fold selectivity with respect to NR1A/2A and NR1A/2C receptors. Potency at alpha(1) adrenergic receptors is low for the four cinnamides tested. Inhibition of NR1A/2B receptors does not correlate with EGFR and ErbB2/neu tyrosine kinase inhibitor activity. The N-(phenylalkyl)cinnamide series we describe provides a novel and structurally diverse framework for designing new NR2B-selective NMDA antagonists as potential CNS therapeutics.