Recombinant protein production by large-scale transient gene expression in mammalian cells: state of the art and future perspectives

The expansion of the biologics pipeline depends on the identification of candidate proteins for clinical trials. Speed is one of the critical issues, and the rapid production of high quality, research-grade material for preclinical studies by transient gene expression (TGE) is addressing this factor in an impressive way: following DNA transfection, the production phase for TGE is usually 2-10 days. Recombinant proteins (r-proteins) produced by TGE can therefore enter the drug development and screening process in a very short time--weeks. With "classical" approaches to protein expression from mammalian cells, it takes months to establish a productive host cell line. This article summarizes efforts in industry and academia to use TGE to produce tens to hundreds of milligrams of r-proteins for either fundamental research or preclinical studies.

Targeting PIM kinases impairs survival of hematopoietic cells transformed by kinase inhibitor-sensitive and kinase inhibitor-resistant forms of Fms-like tyrosine kinase 3 and BCR/ABL

Previous studies have shown that activation of the signal transducer and activator of transcription 5 (STAT5) plays an essential role in leukemogenesis mediated through constitutive activated protein tyrosine kinases (PTK). Because PIM-1 is a STAT5 target gene, we analyzed the role of the family of PIM serine/threonine kinases (PIM-1 to PIM-3) in PTK-mediated transformation of hematopoietic cells. Ba/F3 cells transformed to growth factor independence by various oncogenic PTKs (TEL/JAK2, TEL/TRKC, TEL/ABL, BCR/ABL, FLT3-ITD, and H4/PDGFbetaR) show abundant expression of PIM-1 and PIM-2. Suppression of PIM-1 activity had a negligible effect on transformation. In contrast, expression of kinase-dead PIM-2 mutant (PIM-2KD) led to a rapid decline of survival in Ba/F3 cells transformed by FLT3-ITD but not by other oncogenic PTKs tested. Coexpression of PIM-1KD and PIM-2KD abrogated growth factor-independent growth of Ba/F3 transformed by several PTKs, including BCR/ABL. Targeted down-regulation of PIM-2 by RNA interference (RNAi) selectively abrogated survival of Ba/F3 cells transformed by various Fms-like tyrosine kinase 3 (FLT3)-activating mutants [internal tandem duplication (ITD) and kinase domain] and attenuated growth of human cell lines containing FLT3 mutations. Interestingly, cells transformed by FLT3 and BCR/ABL mutations that confer resistance to small-molecule tyrosine kinase inhibitors were still sensitive to knockdown of PIM-2, or PIM-1 and PIM-2 by RNAi. Our observations indicate that combined inactivation of PIM-1 and PIM-2 interferes with oncogenic PTKs and suggest that PIMs are alternative therapeutic targets in PTK-mediated leukemia. Targeting the PIM kinase family could provide a new avenue to overcome resistance against small-molecule tyrosine kinase inhibitors.

A functional genetic variation of adenosine deaminase affects the duration and intensity of deep sleep in humans

Slow, rhythmic oscillations (<5 Hz) in the sleep electroencephalogram may be a sign of synaptic plasticity occurring during sleep. The oscillations, referred to as slow-wave activity (SWA), reflect sleep need and sleep intensity. The amount of SWA is homeostatically regulated. It is enhanced after sleep loss and declines during sleep. Animal studies suggested that sleep need is genetically controlled, yet the physiological mechanisms remain unknown. Here we show in humans that a genetic variant of adenosine deaminase, which is associated with the reduced metabolism of adenosine to inosine, specifically enhances deep sleep and SWA during sleep. In contrast, a distinct polymorphism of the adenosine A(2A) receptor gene, which was associated with interindividual differences in anxiety symptoms after caffeine intake in healthy volunteers, affects the electroencephalogram during sleep and wakefulness in a non-state-specific manner. Our findings indicate a direct role of adenosine in human sleep homeostasis. Moreover, our data suggest that genetic variability in the adenosinergic system contributes to the interindividual variability in brain electrical activity during sleep and wakefulness.

Comparison of three different solid-phase microextraction fibres for analysis of essential oils in yacon (Smallanthus sonchifolius) leaves

A headspace solid-phase microextraction (HS-SPME) procedure based on three commercialised fibers (100 microm polydimethylsiloxane, 65 microm polydimethylsiloxane-divinylbenzene and 50/30 microm divinylbenzene-Carboxen-polydimethylsiloxane) is presented for the determination of a selected essential oils in dried leaves of yacon (Smallanthus sonchifolius). The extraction performances of these compounds were compared using fibers with one, two and three coatings. The optimal experimental procedures for the adsorption and desorption of target compounds were determined. Significant parameters affecting sorption process such as sample weight, sorption and desorption time and temperature were optimised and discussed. Finally, the optimised procedures were applied successfully for the determination of these compounds in various yacon species. The relative concentration factors of three characteristic components of yacon were measured for relative evaluation of the fiber efficiency. Main essential oils were isolated from dried yacon leaves by appropriate solid-phase microextraction fiber and semi-quantitative analysis of the target volatiles was conducted by gas chromatography-flame ionisation detection (GC-FID) using a capillary column. Three compounds--beta-pinene, caryophylene and y-cadinene were found as the predominant essential oils. Its relative content was important for specification of yacon varieties. Solid-phase microextraction in combination with gas chromatography enabled a rapid and simple determination of relative content of essential oils in yacon.

Enquête téléphonique sur les pratiques cliniques d'analgésie pour les actes invasifs chez les patients sédatés en réanimation en Île-de-France

To assess the practice of analgesia for invasive procedures in critically ill sedated patient in Ile-de-France (French area including Paris). Observational study: phone survey using a standard questionnaire. Only one senior physician in each of 30 intensive care unit (ICU) was questioned. Baseline sedation included systematic analgesia with narcotics in all ICUs. Only 4 physicians declared using a specific pain scale for sedated patients. Only 3 ICUs used written protocols. Procedures, which were thought to be most invasive (catheterization, pleural drainage, fibroscopy) were in most cases preceded by analgesia, but this was seldom the case for less painful events (venous or arterial puncture, tracheal suctioning). Specific pain scales are still underused. In contrast with current guidelines, analgesia for invasive procedures is not systematic but depends on subjective opinions.

[Stomach rupture after nasal oxygen administration]

We report a case of a spontaneous rupture of a normal stomach after therapeutic oxygen administration. In this case, early treatment precluded the need for a laparotomy. This rare complication highlights the importance of the right positioning of a nasal catheter and leads us to question its role compared to other means of oxygen delivery (nasal cannulae, Hudson mask, Venturi mask).

Determination of acrylonitrile in materials in contact with foodstuffs

Monitoring of the content of free acrylonitrile in plastics used for the preparation of viands is necessary due to its negative effect on human health. A content of 20 ppb is the maximal value of free acrylonitrile in such samples. In this case, head-space gas chromatography is most favourable analytical method when combined with the standard addition method together with a mass-spectrometry detector because of a very low concentration of the analyte. In samples taken for analysis, the content of free acrylonitrile was found to be within 5.1 and 10.3 ppb (microg/kg).

Developmental cell death in dictyostelium does not require paracaspase

Apoptotic cell death often requires caspases. Caspases are part of a family of related molecules including also paracaspases and metacaspases. Are molecules of this family generally involved in cell death? More specifically, do non-apoptotic caspase-independent types of cell death require paracaspases or metacaspases? Dictyostelium discoideum lends itself well to answering these questions because 1) it undergoes non-apoptotic developmental cell death of a vacuolar autophagic type and 2) it bears neither caspase nor metacaspase genes and apparently only one paracaspase gene. This only paracaspase gene can be inactivated by homologous recombination. Paracaspase-null clones were thus obtained in each of four distinct Dictyostelium strains. These clones were tested in two systems, developmental stalk cell death in vivo and vacuolar autophagic cell death in a monolayer system mimicking developmental cell death. Compared with parent cells, all of the paracaspase-null cells showed unaltered cell death in both test systems. In addition, paracaspase inactivation led to no alteration in development or interaction with a range of bacteria. Thus, in Dictyostelium, vacuolar programmed cell death in development and in a monolayer model in vitro would seem not to require paracaspase. To our knowledge, this is the first instance of developmental programmed cell death shown to be independent of any caspase, paracaspase or metacaspase. These results have implications as to the relationship in evolution between cell death and the caspase family.

Effects of scopolamine on matching to sample paradigm and related tests in human subjects

This was a double-blind placebo-controlled study with a cross-over design to examine the effects of scopolamine on cognitive functions in young healthy subjects. Scopolamine hydrobromide was administered subcutaneously to 12 subjects (mean +/- SD age 23.8 +/- 2.2 years) at doses of 0.3 and 0.6 mg in comparison with two placebo conditions. Scopolamine at both doses produced marked sedation as rated by subjects and an observer. In the continuous performance test, vigilance was impaired by both doses of scopolamine. The span of apprehension test showed differing results (only the high dose of scopolamine showed a performance decrement only in the three-character version of the span of apprehension test). Significant impairment by both doses of scopolamine was seen in immediate and delayed free recall, continuous visual recognition, running word recognition and running picture recognition. While scopolamine caused a significant slowing in average reaction times for simultaneous matching as well as for delayed matching, subjects made more errors under scopolamine compared to placebo only in delayed matching, not in simultaneous matching. Also, the main outcome of matching to sample showed significant effects only in delayed matching, not in simultaneous matching. Notable in this study is the incongruity between the simultaneous matching test and the span of apprehension test on the one hand and the other cognitive tests used on the other. These results demonstrated that scopolamine has a greater effect on memory than on attention. Thus, the scopolamine-induced effects in the present study seem to be more relevant to Alzheimer's disease in an advanced phase than to normal aging.

Smoke-free cafe in an unregulated European city: highly welcomed and economically successful

OBJECTIVE

In a unique setting with two identical cafes, which only differed in their smoking ordinances, this study assessed the influence of smoking policies on the choice of the cafe, investigated regulatory preferences among customers, and evaluated the claim that smoking cafes have better sales performance in a city without smoking bans.

METHODS

In a parallel assessment, customers of both cafes answered a questionnaire. Sales were compared and air pollutants were measured to confirm air quality differences.

RESULTS

The two customer groups (n = 177) differed only with regard to smoking status (p < 0.01). The smoking regulation was the most often cited selection criterion (83%). In the non-smoking café, 89% indicated that they were usually annoyed by smoke in coffee houses, and 62% would avoid or leave cafes for this reason. Two thirds stated that all cafe/restaurants should offer the opportunity of a smoke-free environment. However, almost half stated that mandatory regulations are not needed and that customers should make individual arrangements based on tolerance and courtesy. Those who were informed about the health effects of secondhand smoke were more likely to call for clear policies. Whereas sales showed no differences, tips were 22% (p < 0.001) higher in the non-smoking cafe.

CONCLUSION

In a generation raised in smoking friendly environments, customers paradoxically ask for a landmark shift towards smoke-free opportunities, while substantially adhering to the tobacco industry paradigm of promoting "tolerance" rather than smoke-free policies. Given the clear preference of a large number of customers, hospitality businesses could, however, greatly profit from offering smoke-free environments even in the absence of regulatory policies.

Biological and biochemical properties of the carbon composite and polyethylene implant materials

We studied the biocompatibility of the carbon composites and polyethylene materials with and without collagen or collagen and proteoglycan cover. We used the in vitro technology to study the adhesion of model cells evalution, their metabolic activity and the production of TNF-alpha as a cytokine model. Under in vivo condition, the biocompatibility of tested polymers were studied in the implantation experiment, subcutaneously in the interscapular region in the laboratory rat. We have found in the in vitro assay favorable proliferation and the smallest production of pro-inflammatory TNF-alpha cytokine in cells adherent to the hydrophobic polyethylene material coated with biological macromolecules. Using in vivo tests performed by the implantation of materials to the rat we demonstrated that the materials are not cytotoxic. The tissue capsule surrounding the implants was not significantly influenced by the type of the implant and the pre-treatment by the biological molecules. However, the foreign-body giant multinucleated cells were observed only in the vicinity of the collagen - covered hydrophobic polyethylene implant. Interestingly, while the collagen coating improved the biocompatibility of tested polymers in vitro, the inflammatory reaction against this covered materials was higher under in vivo conditions. The pre-treatment of carbon composites by both types of biological macromolecules reduced the occurrence of carbon debris in the implantation site. The tested carbon composites and polyethylene materials are not toxic. The pre-treatment of the materials by extracellular matrix components increased their biological tolerance in vitro and reduced implant wears in animal experiment, which can be important for the medical application.

Dictyostelium cell death: early emergence and demise of highly polarized paddle cells

Cell death in the stalk of Dictyostelium discoideum, a prototypic vacuolar cell death, can be studied in vitro using cells differentiating as a monolayer. To identify early events, we examined potentially dying cells at a time when the classical signs of Dictyostelium cell death, such as heavy vacuolization and membrane lesions, were not yet apparent. We observed that most cells proceeded through a stereotyped series of differentiation stages, including the emergence of "paddle" cells showing high motility and strikingly marked subcellular compartmentalization with actin segregation. Paddle cell emergence and subsequent demise with paddle-to-round cell transition may be critical to the cell death process, as they were contemporary with irreversibility assessed through time-lapse videos and clonogenicity tests. Paddle cell demise was not related to formation of the cellulose shell because cells where the cellulose-synthase gene had been inactivated underwent death indistinguishable from that of parental cells. A major subcellular alteration at the paddle-to-round cell transition was the disappearance of F-actin. The Dictyostelium vacuolar cell death pathway thus does not require cellulose synthesis and includes early actin rearrangements (F-actin segregation, then depolymerization), contemporary with irreversibility, corresponding to the emergence and demise of highly polarized paddle cells.

[New materials suitable for implantation--preparation for implants]

PURPOSE OF THE STUDY

Connective tissue components, particularly collagen and proteoglycan, stimulate cell proliferation and thus promote tissue regeneration. This fact was utilized to test some new implant materials, which were covered by these components, for the speed and quality of their encapsulation.

MATERIAL

The materials tested included polyethylene (PE) with either a hydrophobic (HPHO) or a hydrophilic (HPHI) surface and the C-C composite. Before implantation in experimental animals, the materials were coated with a thin layer of collagen-proteoglycan copolymer.

METHODS

Collagen was obtained from calf hide (ISC 40 fraction) and proteoglycan was isolated from calf cartilage with 2M GuHCl. The concentrations of elements in implant materials were assessed by the method of ESCA photoelectron spectroscopy (electron spectroscopy for chemical analysis) and, using a comparison of the values of electron binding energies at inner levels with the published ones, the chemical states of elements were identified.

RESULTS

Carbon, oxygen and silicon were identified on the surface of the PE HPHI sample; carbon, oxygen, calcium, manganese and sulfur were found on the PE HPHO sample and nitrogen, oxygen and fluorine were present on the C-C composite.

DISCUSSION

In our group of patients there was a small rate of rheumatoid arthritis, while in most literature these patients are predominant. In accordance with the outcomes of other authors, ASS is fraught with recurrence. ASS does not strike to fibrous capsule, like an open surgery synovectomy, and from these islands synovialis could regenerate.

CONCLUSIONS

The presence of manganese and calcium on the surfaces of the materials investigated indicates the existence of a collagen-proteoglycan copolymer, which contains NH2 and COO groups derived from collagen and SO4 groups from proteoglycan. It is necessary to verify this theoretical assumption based on measurement data in a biological experiment.

[Changes in the articular compartment in advanced osteoarthritis]

PURPOSE OF THE STUDY

Both synovial and bone forms of osteoarthritis (OA) are characterized by inflammatory processes in the articular compartment. Increasing evidence suggests that changes in bone tissue are important for the deterioration or loss of joint function. Therefore it is reasonable to shift emphasis from research on cartilage to that on other articular tissues, particularly on subchondral bone. The aim of the study was to demonstrate the involvement of several cytokines in OA development and, on the basis of changes of joint markers, to assess the extent of inflammatory process.

MATERIAL

A total of 60 patients with an osseous form of osteoarthritis of the knee joint (28 patients) or the hip joining (32 patients) underwent total knee or hip arthroplasty. The mean age of our patients was 66.7 +/- 10.4 years. Preoperative clinical and radiographic examinations were carried out as well as routine laboratory tests on blood and urine. Samples of urine, blood serum (BS) and synovial fluid (SF), extracts from cartilage (CA) and synovial membrane (SM) and granulation bone tissue were analysed for markers indicating the presence of inflammatory processes in joints.

METHOD

The following markers of inflammatory activity in the bone compartment were investigated: pyridinoline (PYR), deoxypyridinoline (D-PYR), bone alkaline phosphatase (BAP) and chondrex (CHON). The levels of cytokines IL-1 alpha, IL-8, IL-10 and TNF-alpha were assayed by immunoanalysis (ELISA and IMMULITE system) in BS, CA, SM, GT and SF. The tissue samples were obtained during arthroplasty.

RESULTS

In the patients with osteoarthritis, the urinary levels of PYR and D-PYR were higher than control values (70.33 +/- 34.93 vs (41.6 +/- 10.6 nmol/mmol creatinine). No significant differences were found between pre- and post-operative levels. Similarly, the serum levels of BAP and CHON compared with control values were higher (27.65 +/- 12.21 vs 12.2 +/- 2.7 U/L and (96.35 +/- 58.83 vs 43.2 +/- 14.5 ng/ml, respectively). In all articular compartments and in synovial fluid, the level of cytokine IL-8 exceeded concentrations of the other cytokines. In blood serum, only IL-10 levels were markedly increased as against the control group (17.35 +/- 5.82 vs 9.80 +/- 4.40 pg/ml).

DISCUSSION

Primary osteoarthritis is the most common joint disease that deteriorates with age. Its symptoms are pain and a lower range of motion in the joint affected. The initial involvement of articular cartilage progresses to degenerative changes involving synovial and bony structures. This degenerative disease gradually develops into an inflammatory disease. At this stage, osseous tissue shows an increase in metabolism and bone destruction results. In the control of inflammatory reactions by the immune system, cytokines, among other proteins, play an important role: some may enhance inflammation by activating leukocytes (IL-1, TNF-alpha, IL-8) while others, such as IL-10, have anti-inflammatory effects.

CONCLUSION

During osteoarthritis, the articular compartment shows high metabolic processes that, in some patients, may increase and even persist some time after arthroplasty.

Increased IkappaB kinase activity is associated with activated NF-kappaB in acute myeloid blasts

NF-kappaB/Rel transcription factors are modulators of immune and inflammatory processes and are also involved in malignancy. Phosphorylation of the IkappaB inhibitors by the IkappaB kinase (IKK) complex leads to their proteasomal degradation, resulting in activated NF-kappaB. Here, we investigated the activation status of NF-kappaB and the IKK complex in acute myeloid leukemia (AML). Gelshift assays revealed an increased level of activated nuclear NF-kappaB in myeloid blasts. Both bone marrow and peripheral blood blasts from AML patients showed enhanced IKK activity relative to controls, whereas the IKK protein concentrations were comparable. In addition, an increased level of IkappaB-alpha was detected in AML blast cells, although this appeared to be insufficient to block nuclear translocation of NF-kappaB, also confirmed by immunofluorescence. In subtype M4 and M5 AML cells a more extensive NF-kappaB activation and higher IKK activity was found than in M1/M2 specimens. Isolated AML blasts cultured ex vivo responded to external stimulation (TNF, LPS) by further IKK activation, IkappaB degradation and NF-kappaB activation. Preincubation with the proteasome inhibitor PSI inhibited the NF-kappaB system in isolated AML blasts. This study established for the first time a dysregulation of IKK signaling in AML leading to increased NF-kappaB activity suggesting potential therapeutic avenues.

[Relation between cytokines, adhesive immunoglobulins and matrix metalloproteinases in osteoarthritic joints]

BACKGROUND

The dysbalance of proteinase production and their inhibitors leads to destruction of tissues in many pathological processes. Recently it was shown that the expression of proteinases is regulated also by interactions of cells which is mediated by adhesive molecules. We wanted to find out whether this mechanism is involved also in the destruction of joints in osteoarthritis.

METHODS AND RESULTS

Cartilage, synovial and subchondral bone tissues, and synovial fluids were obtained from 23 joints after total endoprosthesis surgery. The solid tissues were extracted by TRIS buffer. The investigated protein concentrations were assessed immunochemicaly. In all specimens gelatinase A, gelatinase B, stromelysin-1, TIMP-1, soluble adhesive molecules sICAM-1 and sVCAM-1 and cytokines TNF-alpha and IL-8 were found. In cartilage and synovial fluid the proteolytic potential of metalloproteinases was balanced with high concentrations of their inhibitor TIMP-1 (259.4 +/- 105.2 pmol/g protein vs 2343.8 +/- 637.5 pmol/g protein in synovial fluid, p < 0.00001, and 178.9 +/- 175.7 pmol/g dry weight vs 647.2 +/- 561.3 pmol/g dry weight in cartilage, p < 0.001) but in synovial tissues and pathological subchondral bones was not (257.4 +/- 617.2 pmol/g dry weight vs 171.3 +/- 170.8 pmol/g dry weight in synovium, p = 0.61716, and 17.4 +/- 15.4 pmol/g dry weight 33.6 +/- 33.3 pmol/g dry tissue in pathological subchondral bone, p = 0.16705).

CONCLUSION

From correlation analysis ensues that the bond of ICAM-1 and VCAM-1 on chondrocytes with appropriate integrin ligands probably leads to up-regulation of gelatinase A and B and to down-regulation of TIMP-1. Moreover it is apparent that TNF-alpha up-regulates both investigated adhesive molecules followed and stromelysin-1 and TIMP-1.

[Imported malaria in children in 1999. Study of the Armand-Trousseau Hospital in Paris]

METHODS

Eighty children were treated at the hospital Armand-Trousseau (Paris, France) for a malaria attack from 1999-01-01 to 2000-02-01.

RESULTS

The parasites were: Plasmodium falciparum: 87.5%, Plasmodium malariae: 12.6%, Plasmodium ovale: 10%, Plasmodium vivax: 6.3%. Mean age was 8.1 years (range: three months to 15 y). The origin of patients was: West Africa for 60 children, Central Africa for ten children and Comores for seven. Sixty-six patients suffered from common malaria attack and seven children were admitted with a presentation of severe malaria. The severe attacks were cerebral malaria for six cases, associated with severe anemia in five cases; the 7th child had a respiratory distress (ARDS) and died. The other six cases were cured without sequelae. Relapses were observed for eight patients: one after a severe cerebral malaria, six after a common P. falciparum attack, one after a P. ovale attack. Parasitemia was higher than in preceding years (mean 2.9%) and more than 5% in 11 cases, but without clear link with severity. Treatment by halofantrine with a single cure was followed by five relapses. None of those children received an effective prophylaxis during and after travel (55/80 without any prophylaxis).

CONCLUSION

These data emphasize the importance of a good appraisal of criteria of severe malaria and lead to advice hospitalization of children with malaria in temperate zone.

Sequestration and phosphorylation of the prostaglandin E2 EP4 receptor: dependence on the C-terminal tail

The prostaglandin E2 (PGE2) EP4 subtype is one of four prostanoid receptors that use PGE2 as the preferred ligand. We have investigated the agonist-mediated regulation of EP4 using a multifaceted approach. Short-term (30 min) agonist challenge of recombinant EP4 expressed in human embryonic kidney 293 cells (EP4-HEK293 cells) with PGE2 (1 microM) resulted in the desensitization of intracellular cyclic AMP (cAMP) accumulation and a reduction in cell surface [3H]PGE2 specific binding sites. These events correlated with sequestration of EP4, as visualized by immunofluorescence confocal microscopy and phosphorylation, as shown by [32P]orthophosphate labeling of the receptor. Stimulation of protein kinase A activity in EP4-HEK293 cells (10 microM forskolin or 1 mM 8-bromo-cAMP) did not induce EP4 desensitization, sequestration, or phosphorylation. In contrast, stimulation of protein kinase C activity (100 nM phorbol 12-myristate 13-acetate) attenuated PGE2-induced adenylyl cyclase activity and increased EP4 phosphorylation, but did not induce sequestration or a reduction in [3H]PGE2 specific binding sites. EP4 receptors containing a third intracellular loop deletion [EP4 (del. 215-263)] or a carboxyl-terminal tail truncation [EP4 (del. 355)] of EP4 were used to demonstrate that the C-terminal tail governs sequestration as well as phosphorylation of the receptor.

H2A.Z is required for global chromatin integrity and for recruitment of RNA polymerase II under specific conditions

Evolutionarily conserved variant histone H2A.Z has been recently shown to regulate gene transcription in Saccharomyces cerevisiae. Here we show that loss of H2A.Z in this organism negatively affects the induction of GAL genes. Importantly, fusion of the H2A.Z C-terminal region to S phase H2A without its corresponding C-terminal region can mediate the variant histone's specialized function in GAL1-10 gene induction, and it restores the slow-growth phenotype of cells with a deletion of HTZ1. Furthermore, we show that the C-terminal region of H2A.Z can interact with some components of the transcriptional apparatus. In cells lacking H2A.Z, recruitment of RNA polymerase II and TATA-binding protein to the GAL1-10 promoters is significantly diminished under inducing conditions. Unexpectedly, we also find that H2A.Z is required to globally maintain chromatin integrity under GAL gene-inducing conditions. We hypothesize that H2A.Z can positively regulate gene transcription, at least in part, by modulating interactions with RNA polymerase II-associated factors at certain genes under specific cell growth conditions.

Newly recognized cellular abnormalities in the gray platelet syndrome

The gray platelet syndrome (GPS) is a rare congenital bleeding disorder in which thrombocytopenia is associated with increased platelet size and decreased alpha-granule content. This report describes 3 new pediatric cases presenting with the classical platelet abnormalities of GPS within one family with normal parents. Examination of blood smears of the 3 patients demonstrated not only gray platelets, but also gray polymorphonuclear neutrophils (PMNs) with decreased or abnormally distributed components of secretory compartments (alkaline phosphatase, CD35, CD11b/CD18). Secondary granules were also decreased in number as assayed by immunoelectron microscopy. These data confirm that the secretory compartments in neutrophils were also deficient in this family. Megakaryocytes (MKs) were cultured from the peripheral blood CD34+ cells of the 3 patients for 14 days, in the presence of thrombopoietin and processed for immunoelectron microscopy. Although von Willebrand factor (vWF) was virtually undetectable in platelets, vWF immunolabeling was conspicuous in cultured maturing MKs, particularly within Golgi saccules, but instead of being packaged in alpha-granules, it was released into the demarcation membrane system. In contrast, P-selectin followed a more classical pathway. Double-labeling experiments confirmed that vWF was following an intracellular pathway distinct from the one of P-selectin. In these 3 new cases of GPS, the MKs appeared to abnormally process vWF, with secretion into the extracellular space instead of normal alpha-granule packaging. Furthermore, the secretory compartment of another blood cell line, the neutrophil, was also affected in this family of GPS.

Biological evaluation of 2-fluoro-2-[123I]iodo-mannose (FIM): biological evaluation of FIM

This paper describes the biodistribution of a radio-iodinated analog of fluorodeoxyglucose (FDG). 123I-2-fluoro-2-iodo-mannose (FIM) was investigated as a potential single photon emission tomography (SPECT) imaging agent. We also compare the results with the observed distribution of the classical PET agent 18F-FDG and newly developed 18F-difluorodeoxyglucose (DFDG). Following radioiodination, the final product was stable in-vitro for 24 hrs. Mice showed a rapid blood clearance and deiodination of the 123I-FIM reflected by high stomach and thyroid uptake. Comparison with 18F-FDG and 18F-DFDG revealed a large discrepancy between the 18F labeled sugars and the 123I-FIM biological distribution. The iodinated product was not found to be a metabolic marker for in-vivo studies.

Determination of myeloid antigen expression on childhood acute lymphoblastic leukaemia cells: discrepancies using different monoclonal antibody clones

Prospective clinical studies including large numbers of patients have led to the conclusion that co-expression of myeloid antigens in childhood acute lymphoblastic leukaemia (My+ ALL) does not have prognostic significance. However, reports of the frequency of My+ ALL in children vary widely across laboratories using different mAb clones and staining and analysing procedures. Taking two commonly accepted thresholds of positivity for myeloid antigens (20 and 30%), we analysed the immunoreactivity of the most widely employed mAb clones against CD13 (SJ1D1, L138 and My7) and CD33 (My9, P67.6 and D3HL60) and compared the proportions of My+ ALL detected by these clones in childhood ALL. The correlation between myeloid antigen expression and the presence of the t(12;21) translocation was analysed concomitantly in the same samples. The percentage of ALL cases positive for myeloid markers varied significantly depending on the mAb clone and the positive threshold. Among patients with B-ALL, the proportion of CD13+ ALL was significantly lower using SJ1D1 than using L138 or My7, while the proportion of CD33+ ALL was significantly higher for My9 than for P67.6 or D3HL60. Analysis of the co-expression of CD13 and CD33 on B-ALL cells using combinations of mAb clones showed that this frequency was either underestimated by the SJ1D1/D3HL60 or overestimated by the L138/P67.6 and My7/My9 combinations. A correlation between CD13/CD33 positivity and the t(12;21) translocation was uniformly observed in B-ALL patients for a positive threshold of 30%, whereas SJ1D1/D3HL60 detected no correlation between t(12;21) and CD13/CD33 positivity when the threshold was lowered to 20%. These data show that the mAb clones commonly used to detect the CD13 and CD33 surface antigens have variable immunoreactivity against childhood ALL cells, which may partly explain the conflicting reports concerning the prognostic significance of myeloid antigen expression in paediatric ALL and its association with different translocations. The present findings may also be of clinical importance for therapeutic choices.

Rapid determination of total trans fat content--an attenuated total reflection infrared spectroscopy international collaborative study

Interest in trans fat labeling has prompted efforts to develop new, more efficient methods for rapidly and accurately determining trans fat content of foods. A novel and rapid (5 min) attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopic procedure was recently developed and applied to food products. This procedure was voted official method AOCS Cd 14d-99 by the American Oil Chemists' Society in 1999 after testing in a 12 laboratory international collaborative study. The results of the study are described in this paper. Analytical ATR-FTIR results exhibited high accuracy in the range 5-40% trans; results tended to have <2% high bias relative to the gravimetrically determined values. The precision of this internal reflection method was found to be superior to the precision of transmission infrared official methods. It is recommended that the applicability of the ATR-FTIR method be limited to trans levels of >5% (as percent of total fat).

Determination of myeloid antigen expression on childhood acute lymphoblastic leukaemia cells: discrepancies using different monoclonal antibody clones

Prospective clinical studies including large numbers of patients have led to the conclusion that co-expression of myeloid antigens in childhood acute lymphoblastic leukaemia (My+ ALL) does not have prognostic significance. However, reports of the frequency of My+ ALL in children vary widely across laboratories using different mAb clones and staining and analysing procedures. Taking two commonly accepted thresholds of positivity for myeloid antigens (20 and 30%), we analysed the immunoreactivity of the most widely employed mAb clones against CD13 (SJ1D1, L138 and My7) and CD33 (My9, P67.6 and D3HL60) and compared the proportions of My+ ALL detected by these clones in childhood ALL. The correlation between myeloid antigen expression and the presence of the t(12;21) translocation was analysed concomitantly in the same samples. The percentage of ALL cases positive for myeloid markers varied significantly depending on the mAb clone and the positive threshold. Among patients with B-ALL, the proportion of CD13+ ALL was significantly lower using SJ1D1 than using L138 or My7, while the proportion of CD33+ ALL was significantly higher for My9 than for P67.6 or D3HL60. Analysis of the co-expression of CD13 and CD33 on B-ALL cells using combinations of mAb clones showed that this frequency was either underestimated by the SJ1D1/D3HL60 or overestimated by the L138/P67.6 and My7/My9 combinations. A correlation between CD13/CD33 positivity and the t(12;21) translocation was uniformly observed in B-ALL patients for a positive threshold of 30%, whereas SJ1D1/D3HL60 detected no correlation between t(12;21) and CD13/CD33 positivity when the threshold was lowered to 20%. These data show that the mAb clones commonly used to detect the CD13 and CD33 surface antigens have variable immunoreactivity against childhood ALL cells, which may partly explain the conflicting reports concerning the prognostic significance of myeloid antigen expression in paediatric ALL and its association with different translocations. The present findings may also be of clinical importance for therapeutic choices.

Poly(HEMA)-collagen composite as a biomaterial for hard tissue replacement

This article briefly reviews the possibilities for hard tissue replacement with a new biomaterial. The basic differences found experimentally for polymer (HEMA) and collagen composite at the biological environment are stressed. The influence of the collagen distribution and matrix porosity of composite material on biodegradation is also discussed.

Adenovirus-mediated atrial natriuretic protein expression in the lung protects rats from hypoxia-induced pulmonary hypertension

Endogenous as well as exogenous atrial natriuretic peptide (ANP) attenuates the development of chronic hypoxic pulmonary hypertension (CHPH) in rats. We built a recombinant adenovirus type 5 containing ANP cDNA under the control of the Rous sarcoma virus long terminal repeat (Ad.ANP). The efficiency of this vector in delivering the ANP gene was first examined in rat primary cultures of pulmonary vessel smooth muscle cells (SMCs) in comparison with Ad.beta GAL. Conditioned medium collected from Ad.ANP-infected cells (1000 TCID(50)/cell) contained 5 x 10(9) M immunoreactive ANP and elicited relaxation of isolated rat pulmonary arteries preconstricted with phenylepinephrine. To examine the effects of adenovirus-mediated ANP expression in the CHPH rat lung, Ad.ANP or Ad.beta GAL was administered via the tracheal route. Immunoreactive ANP was detected in bronchoalveolar fluid as early as 4 days and until 10-17 days after Ad.ANP administration (5 x 10(8) TCID(50)). Lung ANP immunostaining was mainly localized in bronchial and alveolar epithelial cells. As compared with Ad.beta GAL-treated controls, rats given Ad.ANP (5 x 10(8) TCID(50)) on the day before a 2-week exposure to hypoxia (10% O(2)) had lower values for pulmonary artery pressure (32.1 +/- 1.93 vs. 35.5 +/- 2 mmHg, p < 0.01) and Fulton's index (0.52 +/- 0.089 vs. 0.67 +/- 0.12, p < 0.001) and less severe right ventricular hypertrophy and distal vessel muscularization. These results suggest that induction of ANP expression in the lung may hold promise in the treatment of pulmonary hypertension.

Circulating intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin in urological malignancies

Several studies suggest that cellular adhesion molecules (CAM) play a role in cancer progression and metastasis. To evaluate the role of these molecules as possible tumor markers in patients with urological malignancies, we examined the serum levels of intercellular cell adhesion molecule-1 (ICAM-1), vascular cellcular adhesion molecule-1 (VCAM-1) and E-selectin in patients with renal cell-, bladder-, prostate- and testicular cancer. Serum levels of 237 patients with urological cancers, renal cell carcinoma (n = 47), bladder cancer (n = 81), prostate cancer (n = 87) and testicular cancer (n = 22) and a group of 41 patients with benign prostate hyperplasia (BPH) as well as a 42 healthy control persons were examined for CAMs by specific ELISA tests. Serum CAM concentrations of all tumor patients were compared with controls and within the group according to T stage, N stage, tumor grade and extent of distant metastasis. Our results demonstrate that ICAM-1 and VCAM-1 serum levels are not stage dependently elevated; in contrary, they demonstrate a wide range and are highly variable throughout the different cancer types. In renal cell cancer and in bladder cancer, there is a significant difference for ICAM-1 between controls and T3 and T4 and metastatic cancers. A similar difference was found for VCAM-1, however not for E-selectin in any tumor group. Testicular cancer and prostate cancer did not demonstrate any difference in CAM serum levels between patients with tumors and controls. In metastatic renal cell-, bladder- and prostate cancer, the serum levels of ICAM-1 and VCAM-1 showed a tendency to correlate with the extent of metastatis although no statistical difference between patients with a single metastatic lesion and patients with multiple lesions could be demonstrated. The results of this study implicate a rather limited role of cellular adhesion molecules. Despite of significant ICAM-1 or VCAM-1 serum levels in some locally advanced tumors or metastatic disease, this observation does not provide enough relevant clinical information for use as tumor markers.

Adenovirus-mediated transfer of the atrial natriuretic peptide gene in rat pulmonary vascular smooth muscle cells leads to apoptosis

Atrial natriuretic peptide (ANP) exhibits relaxant and growth-inhibiting effects on vascular smooth muscle cells (VSMCs). To obtain ANP gene expression in VSMCs, we built a recombinant adenovirus containing the ANP cDNA controlled by the adenovirus major late promotor (AdMLP-ANP). After pulmonary VSMC treatment with AdMLP-ANP at a multiplicity of infection ranging from 5 to 100 TCID(50)/cell, immunoreactive ANP was detectable in the cell culture medium at a level that reached 101 +/- 27 pmol/well after 2 days. The newly expressed ANP was biologically active, as evidenced by its ability to induce cyclic guanosine monophosphate accumulation in target cells and to mimic the effect of exogenous ANP (10(-8) to 10(-7) mol/L). Cell growth and survival of AdMLP-ANP-infected cells were decreased and were associated with the promotion of VSMC apoptosis. These effects, which occurred at a multiplicity of infection of 10 to 100 TCID(50)/cell, were observed neither in cells infected with the control adenoviral constructs (AdMLP-betaGAL and AdMLP-gD) nor in cells treated with exogenous ANP (10(-7) to 10(-6) mol/L). These results showing VSMC apoptosis in response to ANP gene expression may have important implications for the prevention of vascular remodeling by gene therapy.