Perfusion techniques for minimally invasive valve procedures.

In this paper, we present, in detail, the simplified perfusion technique that we have adopted since January 2009 and that we have utilized in 200 cases for cardiac minimally invasive valvular procedures that were performed through a right lateral mini-thoracotomy in the 3(rd)-4(th) intercostal space. Cardiopulmonary bypass was achieved by means of the direct cannulation of the ascending aorta and the insertion of a percutaneous venous cannula in the femoral vein. A flexible aortic cross-clamp was applied through the skin incision and cardioplegic arrest was obtained with the antegrade delivery of a crystalloid solution. Gravity drainage was enhanced by vacuum-assisted aspiration. There were no technical complications related to this perfusion technique that we have adopted in minimally invasive surgical procedures.

Reduced transfusion requirements with a closed cardiopulmonary bypass system.

AIM: The aim of this investigation is to reduce blood transfusion in cardiac surgery patients with preoperative conditions predictive for transfusion requirements. We compared the amount of blood transfused in two groups of patients undergoing cardiopulmonary bypass (CPB) with two different circuit systems. METHODS: Sixty patients undergoing cardiac surgery were randomly assigned to two groups: in group A (N=30) cardiopulmonary bypass was accomplished with an open circuit and in group B (N=30) with a closed circuit. The open circuit consisted of a cardiotomy reservoir, a membrane oxygenator and an arterial line filter, while the closed circuit was made up of a collapsible venous reservoir, a membrane oxygenator, an arterial line filter and a cardiotomy reservoir. The amount of transfused packed red cells in each patient was measured until discharge from the hospital. RESULTS: Groups were similar regarding age, gender, body surface area (BSA), New York Heart Association (NYHA) class and comorbidity risk factors. Moreover, there were no significant differences between groups regarding the type of procedures, CPB and aortic cross-clamp times, total amount of cardioplegia and urinary output during CPB. Priming volume was 1180+/-84 mL (group A) and 760+/-72 mL (group B) (P<0.001). Significant differences in transfusion requirements emerged in the two groups: the total volume of packed red cells transfused for each patient was significantly higher in the open system group compared to the closed system group (717+/-486 mL versus 378+/-364 mL) (P=0.003). Clinical outcomes were similar in both groups. CONCLUSION: In patients with preoperative conditions predictive for the need of transfusions, the use of a closed cardiopulmonary bypass circuit can diminish the amount of transfused blood products.

Use of polylactic acid in face lipodystrophy in HIV positive patients undergoing treatment with antiretroviral drugs (HAART).

OBJECTIVES: The recent use of antiretroviral drugs in people with HIV infection produced a drastic reduction in mortality and a remarkable improvement in the quality of life for these patients. However the aesthetic and psychological consequences that come from the reorganization of the adipose tissue induced by these drugs (facial wasting, buffalo hump) may reduce this state of wellbeing. METHODS: Our group, in cooperation with the 3rd Division of Infective Diseases of the University of Rome "La Sapienza", decided to evaluate the efficacy of polylactic acid (PLA) in combating these problems in HIV positive patients undergoing treatment with antiretroviral drugs in an evaluating study of 4 cases. The evaluation of the obtained results was performed by follow-up at one, three, six and twelve months from the first infiltration and considering the clinical evaluation, the photographical documentation and the patient's judgement. RESULTS: In all cases we obtained an improvement of the local condition with the restoration of a more booming aspect. The change was noted both within the family and the work environment. In the first three cases the results were considered as optimal by both the operators and the patients. In the fourth case the result was evaluated as discreet (a remarkable loss of weight of the patient in the months following the treatment should be taken into consideration). CONCLUSIONS: We think a new study with ultrasonography of dermal thickness before, during and after the treatment is necesary. This study will give a more reliable evaluation of the product efficacy.

Regulated Ran-binding protein 1 activity is required for organization and function of the mitotic spindle in mammalian cells in vivo.

Ran-binding protein (RanBP) 1 is a major regulator of the Ran GTPase and is encoded by a regulatory target gene of E2F factors. The Ran GTPase network controls several cellular processes, including nucleocytoplasmic transport and cell cycle progression, and has recently also been shown to regulate microtubule nucleation and spindle assembly in Xenopus oocyte extracts. Here we report that RanBP1 protein levels are cell cycle regulated in mammalian cells, increase from S phase to M phase, peak in metaphase, and abruptly decline in late telophase. Overexpression of RanBP1 throughout the cell cycle yields abnormal mitoses characterized by severe defects in spindle polarization. In addition, microinjection of anti-RanBP1 antibody in mitotic cells induces mitotic delay and abnormal nuclear division, reflecting an abnormal stabilization of the mitotic spindle. Thus, regulated RanBP1 activity is required for proper execution of mitosis in somatic cells.

A fraction of mouse sperm chromatin is organized in nucleosomal hypersensitive domains enriched in retroposon DNA.

We have characterized a nuclease hypersensitive chromatin fraction from murine spermatozoa. Endogenous nuclease activity can be induced in mouse epididymal spermatozoa by appropriate stimuli and cause the localized degradation of chromosomal DNA. Based on these observations, we have isolated nuclease hypersensitive chromatin regions released from spermatozoa in the supernatant of pelleted sperm cells, and have cloned and characterized the DNA. Gel electrophoresis of end-labelled released DNA fragments showed a typical nucleosomal distribution. Peripherally distributed nucleohistones were visualized by immunofluorescence in sperm nuclei, and histones were identified by western blot in sperm chromatin. Moreover, the released DNA is enriched in retroposon DNA from a variety of families. FISH and immunofluorescence analysis showed that retroposon DNA and nucleohistone chromatin co-localize and are both peripherically distributed in nuclei of spermatozoa. In contrast, a major satellite DNA probe, used for control, co-localizes with highly condensed chromatin in the central region of sperm nuclei. The nuclear Ran and RCC1 proteins were also visualized in the dorsal margin of sperm nuclei, and were abundantly released with the hypersensitive chromatin fraction. Together, these results indicate that nucleohistone chromatin fraction(s) with typical features of 'active' chromatin are present in murine spermatozoa, are hypersensitive to nuclease cleavage, enriched in retroposon DNA and organized in nucleosomal domains. These observations suggest that nucleohistone domains identify a fraction of the sperm genome which may be functional during early embryogenesis.

Active MAP kinase in mitosis: localization at kinetochores and association with the motor protein CENP-E.

To investigate possible involvement of the mitogen-activated protein (MAP) kinases ERK1 and ERK2 (extracellular signal-regulated kinases) in somatic cell mitosis, we have used indirect immunofluorescence with a highly specific phospho-MAP kinase antibody and found that a portion of the active MAP kinase is localized at kinetochores, asters, and the midbody during mitosis. Although the aster labeling was constant from the time of nuclear envelope breakdown, the kinetochore labeling first appeared at early prometaphase, started to fade during chromosome congression, and then disappeared at midanaphase. At telophase, active MAP kinase localized at the midbody. Based on colocalization and the presence of a MAP kinase consensus phosphorylation site, we identified the kinetochore motor protein CENP-E as a candidate mitotic substrate for MAP kinase. CENP-E was phosphorylated in vitro by MAP kinase on sites that are known to regulate its interactions with microtubules and was found to associate in vivo preferentially with the active MAP kinase during mitosis. Therefore, the presence of active MAP kinase at specific mitotic structures and its interaction with CENP-E suggest that MAP kinase could play a role in mitosis at least in part by altering the ability of CENP-E to mediate interactions between chromosomes and microtubules.

MPM-2 antibody-reactive phosphorylations can be created in detergent-extracted cells by kinetochore-bound and soluble kinases.

The MPM-2 antibody labels mitosis-specific and cell cycle-regulated phosphoproteins. The major phosphoproteins of mitotic chromosomes recognized by the MPM-2 antibody are DNA topoisomerase II (topoII) alpha and beta. In immunofluorescence studies of PtK1 cytoskeletons, prepared by detergent lysis in the presence of potent phosphatase inhibitors, the MPM-2 antibody labels phosphoproteins found at kinetochores, chromosome arms, midbody and spindle poles of mitotic cells. In cells extracted without phosphatase inhibitors, labeling of the MPM-2 antibodies at kinetochores is greatly diminished. However, in cytoskeletons this epitope can be regenerated through the action of kinases stably bound at the kinetochore. Various kinase inhibitors were tested in order to characterize the endogenous kinase responsible for these phosphorylations. We found that the MPM-2 epitope will not rephosphorylate in the presence of the broad specificity kinase inhibitors K-252a, staurosporine and 2-aminopurine. Several other inhibitors had no effect on the rephosphorylation indicating that the endogenous MPM-2 kinase at kinetochores is not p34cdc2, casein kinase II, MAP kinase, protein kinase A or protein kinase C. The addition of N-ethylmaleimide inactivated the endogenous kinetochore kinase; this allowed testing of several purified kinases in the kinetochore rephosphorylation assay. Active p34cdc2-cyclin B, casein kinase II and MAP kinase could not generate the MPM-2 phosphoepitope. However, bacterially expressed NIMA from Aspergillus and ultracentrifuged mitotic HeLa cell extract were able to catalyze the rephosphorylation of the MPM-2 epitope at kinetochores. Furthermore, fractionation of mitotic HeLa cell extract showed that kinases that create the MPM-2 epitope at kinetochores and chromosome arms are distinct. Our results suggest that multiple kinases (either soluble or kinetochore-bound), including a homolog of mammalian NIMA, can create the MPM-2 phosphoepitope. The kinetochore-bound kinase that catalyzes the formation of the MPM-2 phosphoepitope may play an important role in key events such as mitotic kinetochore assembly and sister chromatid separation at anaphase.

Micronucleus induction in germ and somatic cells of the mouse after exposure to the butadiene metabolites diepoxybutane and epoxybutene.

The genotoxicity of diepoxibutane (DEB) and epoxybutene (EB), two of the main metabolites of 1,3-butadiene, was tested in the germ and somatic cells of the mouse by applying an MN assay in early spermatids, and in peripheral blood reticulocytes of a subgroup of the same animals. DEB (0.17 and 0.35 mmol/kg) and EB (0.35, 0.70 and 1.04 mmol/kg) were administered i.p. In the germ cell assay, significant increases of MN were observed after treatment of premeiotic S-phase cells with both butadiene metabolites, but DEB was shown to be more powerful than EB in the induction of chromosomal damage. A weak effect of the same compounds was also found after treatment of late spermatocytes, approaching the meiotic divisions. From the MN assay in peripheral blood reticulocytes, a statistically significant increase of the frequency of MN was detected at each dose tested for both chemicals. However, the results have again shown that DEB is much more efficient than EB in inducing chromosome damage.

Detection of minor and major satellite DNA in cytokinesis-blocked mouse splenocytes by a PRINS tandem labelling approach.

A protocol for the simultaneous visualization of minor and major satellite DNA by primed in situ DNA synthesis (PRINS) was developed in cytokinesis-blocked murine splenocytes. After individuation of optimal experimental conditions, a micronucleus (MN) test was carried out by treating splenocytes in vitro with the clastogenic agent mitomycin C and the aneugenic compound Colcemid. It was found that PRINS gives highly reproducible results, also comparable with the literature on MN results obtained by fluorescent in situ hybridization (FISH). Therefore the PRINS methodology may be proposed as a fast alternative to FISH for the characterization of induced MN.

The centromere as a target for the induction of chromosome damage in resting and proliferating mammalian cells: assessment of mitomycin C-induced genetic damage at kinetochores and centromeres by a micronucleus test in mouse splenocytes.

The cytokinesis-block micronucleus assay (MN) on murine splenocytes was used for the estimation of chromosome damage in a resting cell population in vivo that can be induced to proliferate in vitro. Mitomycin C at different doses (10(-8), 6 x 10(-8), 10(-7), 6 x 10(-7) and 10(-6)M) was used to induce cytogenetic damage in resting and cycling splenocytes. Antikinetochore antibodies (CREST) and two-colour fluorescence in situ hybridization (FISH) with minor and major satellite DNA were applied. These approaches allowed the detailed characterization of the mechanisms by which MN originates, since it was possible to identify breaks induced in pericentric heterochromatic (resulting in MN containing the major but not the minor satellite DNA) or detachment/disruption of kinetochore (resulting in different frequencies of MN containing kinetochore or both probes). Based on the evidence that resting and cycling mouse splenocytes are characterized by different spatial distribution of centromeric regions, the hypothesis was tested that the damage induced by mutagens at centromeres is influenced by the phase of the cell cycle in which the cells are treated. Data presented here show that resting and cycling splenocytes are both sensitive to mitomycin C action, and indicate that this compound has an aneugenic potential, besides its strong clastogenic activity. In particular, results obtained after CREST and FISH characterization of MN differed when cells were treated during proliferation, suggesting a disruption/detachment of kinetochores induced by mitomycin C at this cell stage. Furthermore, under the same treatment condition the proportion of MN containing the major satellite DNA only was greater than expected on the basis of random breakage at this site. Treatment of resting cells produced aneugenic damage, but without evidence of disruption/detachment of kinetochores or preferential breakage at the centromere. These results indicate that the amount and type of chromosome damage induced by mitomycin C in mouse splenocytes differ in relation to the proliferative status of treated cells.

Induction of micronuclei in peripheral blood and bone marrow erythrocytes of rats and mice exposed to 1,3-butadiene by inhalation.

Female CB6F1 mice and male Wistar rats were exposed to different concentrations of 1,3-butadiene (1,3-BD) by inhalation. Micronucleus tests using both peripheral blood erythrocytes and femoral marrow cells of these animals were performed. Cells were stained either using conventional acridine orange (AO) staining or supravitally using AO-coated slides. Dose-dependent increases in the frequency of micronuclei (MN) were observed both in blood and in bone marrow cells in mice. 1,3-BD did not, however, increase the frequency of MN in either blood or bone marrow cells of rats at any of the tested concentrations.

Detection of whole chromosomes in micronuclei of cytokinesis-blocked human lymphocytes by antikinetochore staining and in situ hybridization.

The effect of cytochalasin B (Cyt-B; 3 and 6 micrograms/ml; for the last 28 h) on micronuclei (MN) was studied in 72-h purified lymphocyte cultures of three male donors. The frequency of MN was much higher in multinucleate cells (mean 100-204 MN per 1000 cells) than in binucleate cells (mean 8.2-21.0 MN per 1000 cells), tetranucleate cells containing more MN than trinucleate cells. The presence of whole chromosomes in the MN was studied in two separate experiments by immunofluorescence using antikinetochore (CREST) serum and by a centromeric alphoid DNA oligomer probe (in situ hybridization, ISH). In the tri- and tetra-nucleate cells produced by Cyt-B, MN were clearly more often kinetochore-positive (K+) (mean 82-86%) and centromere-positive (C+) (mean 73-83%) than in mononucleate cells of cultures containing no Cyt-B (mean 63% for CREST and 50% for ISH), indicating that most of the excess MN in the multinucleate cells were due to whole chromosomes. The binucleate lymphocytes had about as high prevalence of K+MN (mean 79-84%) as the tri- and tetra-nucleate cells, despite their low MN count. Also in the ISH analysis, the majority of MN in binucleate cells were positively stained (mean 58-62%). If it is assumed that the extra labelled MN are due to Cyt-B, the present findings suggest that Cyt-B could be responsible for approximately 45-57% (CREST data) or approximately 17-23% (ISH data) of MN in binucleate cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Micronucleus assay in lymphocytes as a tool to biomonitor human exposure to aneuploidogens and clastogens.

The analysis of micronuclei (MN) in cultured human lymphocytes is, in principle, able to detect exposure to clastogens and aneuploidogens alike. There is, however, no clear evidence from human biomonitoring studies or animal experiments showing that in vivo exposure of resting lymphocytes to an aneuploidogen could actually be expressed as MN in cultured lymphocytes. In vitro, a pulse treatment of human lymphocytes with vinblastine, an aneuploidogen, did result in MN induction even if performed before mitogen stimulation, although a much more pronounced effect was obtained in actively dividing lymphocyte cultures. On the other hand, it is probable that a considerable portion of "spontaneous" MN contain whole chromosomes, their contribution increasing with age. It also seems that cytochalasin B, used for the identification of second cell cycle interphase cells in the MN assay, is able to slightly increase the level of MN with whole chromosomes. If MN harboring chromosome fragments represent a minority of the total MN frequency, there may be difficulties in detecting a weak effect in this fraction of MN against the background of MN with whole chromosomes. This would reduce the sensitivity of the assay in detecting clastogens, unless MN with whole chromosomes and chromosome fragments are distinguished from each other. That a problem may exist in sensitivity is suggested by the difficulty in demonstrating MN induction by smoking, an exposure capable of inducing chromosome aberrations. The sensitivity of the lymphocyte MN assay could be increased by detecting kinetochore or centromere in MN, or by automation, allowing more cells to be analyzed.

The micronucleus assay in mouse peripheral blood reticulocytes demonstrates the transmission of chromosomal instability induced by mitomycin C and benzo[a]pyrene.

The frequency of micronuclei (MN) in mouse peripheral blood reticulocytes supravitally stained with acridine orange was assessed at different time intervals after treatment in vivo with two dose levels of mitomycin C (MMC) and benzo[a]pyrene. Increased frequencies were observed for many days after treatment, indicating that MN may be produced as a consequence of chromosomal instability transmitted by proliferating erythroblasts. These results confirm previous evidence of the persistent cytogenetic effects of MMC and suggest that clastogenic agents acting by different primary lesions may have a similar ability to induce this effect.

Persistence of chromosomal lesions induced in actively proliferating bone marrow cells of the mouse.

The persistence of chromosomal lesions induced in vivo by mitomycin C (MMC) was evaluated by cytogenetic analysis of mouse bone marrow cells. Chromosome aberration (CA) and micronucleus (MN) frequencies were estimated at different times after treatment, up to 42 days. The frequency of CA per cell decreased in the first 3 days after treatment, but a secondary peak appeared on the 4th day, followed by a stabilization around 0.03 CA per cell (significantly different from the control value), which persisted up to 17 days. At the next time intervals tested (28 and 42 days), the CA frequency returned to the control level. In disagreement with these data obtained directly on metaphases, the MN frequency, as evaluated in polychromatic erythrocytes, decreased quickly after treatment, reaching the control value on the 5th day. We attempted to enhance the sensitivity of the MN test by using CREST antibodies and indirect immunofluorescence. However, higher proportions of CREST- MN in treated than in control animals were observed only at short time intervals, confirming the results obtained with the conventional MN assay.

Further in vitro and in vivo mutagenicity assays with thiram and ziram fungicides: bacterial reversion assays and mouse micronucleus test.

The fungicides thiram and ziram have been assayed in a battery of nine bacterial strains of different genetic specificity. The results obtained suggest the induction of excisable DNA lesion(s), and indicate similar mutability of strains with AT or GC base pairs at target sites. This mutagenic profile is clearly distinct from that of oxidative mutagens, and it does not support the proposed role of oxidative stress in the mechanism of dithiocarbamates mutagenicity in bacteria. Furthermore, the bone marrow micronucleus test has been carried out in B6C3F1 mice with intraperitoneal administration of high grade thiram (12.5-50 mg/kg) and ziram samples (2.5-10 mg/kg in males, and 5-20 mg/kg in females). Thiram produced a significant increase of micronucleated PCEs in male mice sampled 48 h after treatment with 25, 37.5, and 50 mg/kg. No significant increase was detected in treated females. Ziram, tested in a lower range of doses because of its higher toxicity, resulted negative in both sexes. Both the acute toxicity and the ratio polychromatic/normochromatic erythrocytes indicated some sex specificity in the toxic effects induced by these dithiocarbamates in the B6C3F1 mouse.