fMRI-Based Effective Connectivity in Surgical Remediable Epilepsies: A Pilot Study.

Simultaneous EEG-fMRI can contribute to identify the epileptogenic zone (EZ) in focal epilepsies. However, fMRI maps related to Interictal Epileptiform Discharges (IED) commonly show multiple regions of signal change rather than focal ones. Dynamic causal modeling (DCM) can estimate effective connectivity, i.e. the causal effects exerted by one brain region over another, based on fMRI data. Here, we employed DCM on fMRI data in 10 focal epilepsy patients with multiple IED-related regions of BOLD signal change, to test whether this approach can help the localization process of EZ. For each subject, a family of competing deterministic, plausible DCM models were constructed using IED as autonomous input at each node, one at time. The DCM findings were compared to the presurgical evaluation results and classified as: "Concordant" if the node identified by DCM matches the presumed focus, "Discordant" if the node is distant from the presumed focus, or "Inconclusive" (no statistically significant result). Furthermore, patients who subsequently underwent intracranial EEG recordings or surgery were considered as having an independent validation of DCM results. The effective connectivity focus identified using DCM was Concordant in 7 patients, Discordant in two cases and Inconclusive in one. In four of the 6 patients operated, the DCM findings were validated. Notably, the two Discordant and Invalidated results were found in patients with poor surgical outcome. Our findings provide preliminary evidence to support the applicability of DCM on fMRI data to investigate the epileptic networks in focal epilepsy and, particularly, to identify the EZ in complex cases.

Propofol and survival: a meta-analysis of randomized clinical trials.

BACKGROUND: One of the most commonly used hypnotics is propofol. Several studies performed in cardiac surgery suggested an increased mortality in patients receiving a propofol-based total intravenous anaesthesia. Furthermore, the possibility of infections and the 'propofol syndrome' have suggested that propofol might be dangerous. Nonetheless, propofol is widely used in different settings because of its characteristics: fast induction, rapid elimination, short duration of action, smooth recovery from anaesthesia, few adverse effects, no teratogenic effects, characteristics that have undoubtedly contributed to its popularity. The effect of propofol on survival is unknown. We decided to carry out a meta-analysis of all randomized controlled studies ever performed on propofol vs. any comparator in any clinical setting. METHODS: Pertinent studies were independently searched in BioMedCentral, PubMed, Embase, Clinicaltrial.gov, and Cochrane Central Register of Clinical Trials by expert investigators. The following inclusion criteria were used: random allocation to treatment, comparison between propofol and any comparator in any clinical setting. RESULTS: One hundred thirty-three studies randomizing 14,516 patients were included. No differences in mortality between patients receiving propofol [349/6957 (5.0%)] vs. any comparator [340/7559 (4.5%)] were observed in the overall population [risk ratio = 1.05, 95% confidence interval (0.93 to 1.18), P = 0.5] and in several sub-analyses. CONCLUSION: Inspite of theoretical concerns, propofol has no detrimental effect on survival according to the largest meta-analysis of randomized trials ever performed on hypnotic drug.

Non-invasive ventilation after cardiac surgery outside the Intensive Care Unit.

BACKGROUND: Non-invasive ventilation (NIV) can prevent or treat postoperative acute respiratory failure. NIV after discharge from the Intensive Care Unit (ICU) has never been described in the setting of cardiac surgery. METHODS: This study enrolled 85 patients who received NIV in the main ward as treatment for respiratory failure. The patients had the following conditions: atelectasis (45 patients), pleural effusion (20 patients), pulmonary congestion (13 patients), diaphragm hemiparesis (6 patients), pneumonia (4 patients) or a combination of these conditions. RESULTS: Eighty-three patients were discharged from the hospital in good condition and without need for further NIV treatment, while two died in-hospital. Four of the 85 patients had an immediate NIV failure, while eight patients had delayed NIV failure. Only one patient had a NIV-related complication represented by hypotension after NIV institution. In this patient, NIV was interrupted with no consequences. Major mistakes were mask malpositioning with excessive air leaks (7 patients), incorrect preparation of the circuit (one patient), and oxygen tube disconnection (one patient). Minor mistakes (sub-optimal positioning of the face mask without excessive air leaks) were noted by the respiratory therapists for all patients and were managed by slightly modifying the mask position. CONCLUSION: In our experience, postoperative NIV is feasible, safe and effective in treating postoperative acute respiratory failure when applied in the cardiac surgical ward, preserving intensive care unit beds for surgical activity. A respiratory therapy service managed the treatment in conjunction with ward nurses, while an anesthesiologist and a cardiologist served as consultants.

HLA DR-DQ combination associated with the increased risk of developing human HCV positive non-Hodgkin's lymphoma is related to the type II mixed cryoglobulinemia.

This investigation was focused on the contribution of individual human leukocyte antigen (HLA)-DR and -DQ alleles to the human hepatitis C virus (HCV)(+) non-Hodgkin's lymphoma (NHL), with and without mixed cryoglobulinemia (MC), to study whether individual HLA class II alleles are expressed preferentially or equally in human HCV-specific NHL. For this purpose, peripheral blood mononuclear cells were obtained from two groups of patients with HCV(+) NHL and with or without MC (70 and 71 cases, respectively), and from 4575 blood donors. Eighty-three subjects with HCV infection only, and 118 patients with MC, only without lymphoma, were added as additional control groups. Individual HLA-DR and -DQ alleles were determined using high-resolution sequence-based typing and then data were collected by considering the HLA-DRB1 and DQB1 supertypes on the basis of common structural and functional features, proposed by in silico Bioinformatic studies. From the data, it is evidenced that the DR5-DQ3 HLA combination was strongly associated with the HCV (+) MC (+) NHL group of patients compared with bone marrow donor population (P

Emergency in cryoglobulinemic syndrome: what to do?

The clinical course of cryoglobulinemic syndrome (CS) is usually slow; however, fast aggravations have been frequently reported in recent years. In these cases vasculitic ischemic tissue damage accounts for glomerular involvement, neuropathy, cutaneous ulcers, ischemic heart disease, lung or jejunal impairment and stroke. Other critical events in CS may be represented by sepsis, liver insufficiency, hepatocellular carcinoma and non-Hodgkin's lymphomas. Sometimes emergency can not be controlled and the evolution is fatal. Long-term follow up, emergency outcome and cause of death have not been considered in controlled studies, in large series. Here we report a 53-year old woman affected by IgG-IgMk type II HCV-related mixed cryoglobulinemia, who presented several critical events over the course of the disease, which required therapeutical emergency interventions. The latter consisted of plasma exchange, cytotoxic agents, corticosteroids, intravenous immunoglobulin, antihypertensive drugs, antibiotics, and rituximab. Eventually no therapy was effective and the patient died from a catastrophic-like syndrome. This case is relevant because it enables us to consider some important steps in the treatment of emergency in CS.

Causes of death in symptomatic cryoglobulinemia: 30 years of observation in a Department of Internal Medicine.

UNLABELLED: Cryoglobulinemic Syn&come (CS) is a multi-systemic disease, and its fatal evolution can involve different organs. AIMS: To describe the most frequent causes of death in CS, by researching different evolutions between older cases and those of the last 15 years. PATIENTS: The data of 238 patients affected by symptomatic cryoglobulinemia followed by our Medicine Department in the last 30 years are recorded in a database. 54 are presently living and being followed, 70 (36F, 34M) have died. The type II/type III ratio is 5/4. We distinguish between two groups, the oldest, without any data on HCV, and the most recent who were tested for HCV. The follow-up ranges from 0.5 to 16 years. RESULTS: Liver diseases (25 cases, 9 with hepatic carcinomas), lymphomas and myeloproliferative diseases (12), and cardiovascular events (8) are the most reported causes of death. Sepsis, neurological syndromes, nephropathy, other malignancies and diffuse vasculitis are also reported. The median age at death was 67.2 years (58.4 in the oldest group, 71.9 in the other). Hepatic carcinomas are reported only after 1991. CONCLUSION: Cirrhosis complications are more frequent in patients affected by HCV. The increase in instrumental diagnostic ability and the improved survival of patients with cirrhosis account for the increase in patients with hepatic carcinomas. Improved treatment has resulted in a reduction of deaths from renal failure.

Genetic insights into the disease mechanisms of type II mixed cryoglobulinemia induced by hepatitis C virus.

The ability of the immune system to distinguish between self and non-self is critical to the functioning of the immune response. A breakdown in these mechanisms can lead to the onset of autoimmune disease. Clinical and molecular data suggest that shared immunogenetic mechanisms lead to the autoimmune process. The most studied part of the autoimmune process is the human leukocyte antigen (HLA) region. Recently, progress has been made in narrowing down HLA cluster classifications based on structural and functional features of HLA alleles. Using this approach we have investigated 175 patients with hepatitis C virus (HCV)-induced type II cryoglobulinemia (MC), and compared them to a control group of 14,923 bone marrow donors. Additionally, we investigated the frequency of HLA homozygosity in the same groups of subjects. Our results provide evidence of a role for DR5 and DQ3 HLA class II clusters and a higher frequency of HLA homozygous leading to the clinical outcome of type II mixed cryoglobulinemic autoimmune disease. The DR5 cluster is characterized by a Glu in beta 9 and its polymorphism is connected with preferred anchors at beta 9 of the binding peptide, while the DQ3 cluster is characterized by Glu B86 and Leu B87, which allows the binding of large hydrophobic amino acids at p1 of the binding peptide. The mechanisms by which variations in HLA lead to autoimmunity remain unknown, although they are likely to be mediated by continuous presentation of HCV epitopes to T cells and a genetic background that limits the effective clearance of HCV. The results presented in this paper have increased our knowledge of the mechanism of autoimmune disease and B-cell lymphoproliferation during HCV infection. The work was performed in accordance with the principles of the 1983 Declaration of Helsinki. There is no conflict of interest.

The DOse REsponse Multicentre International Collaborative Initiative (DO-RE-MI).

BACKGROUND: Current practices for renal replacement therapy (RRT) in ICU remain poorly defined. The observational DOse REsponse Multicentre International collaborative initiative (DO-RE-MI) survey addresses the issue of how the different modes of RRT are currently chosen and performed. The primary endpoint of DO-RE-MI will be the delivered dose versus in ICU, 28-day, and hospital mortality, and the secondary endpoint, the hemodynamic response to RRT. Here, we report the first preliminary descriptive analysis after 1-year recruitment. METHODS: Data from 431 patients in need of RRT with or without acute renal failure (mean age 61.2+15.9) from 25 centers in 5 countries (Spain, Italy, Germany, Portugal, France) were entered in electronic case report forms (CRFs) available via the website acutevision.net. RESULTS: On admission, 51% patients came from surgery, 36% from the emergency department, and 16% from internal medicine. On admission, mean SOFA and SAPS II were 13 and 50, respectively. The first criteria to initiate RRT was the RIFLE in 38% (failure: 70%, injury: 25%, risk: 22%), the second the high urea/creatinine, and the third immunomodulation. A total of 3,010 cumulative CRF were reported: continuous venovenous hemodiafiltration (CVVHDF) 60%, continuous venovenous hemofiltration (CVVH) 15%, intermittent hemodialysis (IHD) 15%, high-volume hemofiltration (HVHF) 7%, continuous venovenous hemodialysis (CVVHD) 1%, and coupled plasma filtration adsorption/CVVD 2%. In 15% of cases, the patient was shifted to another modality. Mean blood flow rates (ml/min) in the different modalities were: 145 (CVVHDF), 200 (CVVH), 215 (IHD), 283 (HVHF), and 150 (CVVHD). Downtime ranged from 8 to 28% of the total treatment time. Clotting of the circuit accounted for 74% of treatment interruptions. CONCLUSIONS: Despite a large variability in the criteria of choice of RRT, CVVHDF remains the most used (49%). Clotting and clinical reasons were the most common causes for RRT downtime. In continuous RRT, a large variability in the delivered dose is observed in the majority of patients and often in the same patient from one day to another. Preliminary analysis suggests that in a large number of cases the delivered dose is far from the 'adequate' 35 ml/h/kg.

Evaluation of natural transmission of bovine leukaemia virus within dairy herds of Argentina.

The purpose of this study was to describe patterns of seroconversion to bovine leukaemia virus and to estimate the main parameters needed for future model building. A longitudinal study was carried out between February 1999 and November 2001 in seven commercial dairy farms in Argentina using 1535 lactating cows. Time-interval parameters were analysed using a parametric survival model with shared frailty, time until infection was analysed using a Bayesian interval-censoring survival model and the infection transmission parameter (beta) was estimated by a generalized linear model. The reproduction ratio (R0) was calculated. In total, 1000 cows tested positive and 494 tested negative. The predicted median age at infection was 4.6 years for seroconverted cows. For infected herds, the proportion of positive calves was as high as for infected cows and showed a large proportion of infected breeding heifers. Peaks in the overall average incidence per season-year were observed during autumn and spring. Results reveal that the period around parturition is a high-risk period. Moreover, heavily infected herds seem to have an increased proportion of young stock infected. The overall beta was estimated as 2.9/year (95% CI 1.9-3.7) and combined with a relatively long infectious period it resulted in a high reproductive ratio (R0=8.9). Therefore, a high effectiveness of control measures needs to be achieved to eradicate the disease.

Transmission of bovine leukaemia virus within dairy herds by simulation modelling.

In Argentina, bovine leukaemia virus (BLV) infection is common in dairy herds. The country currently has a National Voluntary Control Programme but relatively few farms have enrolled. However, there is increased interest from authorities and farmers to implement regional compulsory programmes but there is scarce quantitative information of the transmission of BLV in cattle herds. This information is a prerequisite to develop effective BLV control strategies. Mathematical modelling offers ways of integrating population-level knowledge and epidemiological data to predict the outcomes of intervention scenarios. The purpose of the current paper is to gain understanding about the dynamics of the transmission of BLV in dairy herds from Argentina by simulation and to compare various BLV transmission models and select the one that is most appropriate. The hypothetical herd is conceptually described in terms of BLV status as a population of individuals that are protected by maternal antibodies (M), that are susceptible (S), that are in the latent period (E) or that are infectious (I). BLV is spread by horizontal and vertical transmission. We used an age-structured population model and within-herd transmission was simulated by Monte Carlo techniques. The next-generation approach has been used for the systematic computation of the basic reproduction ratio (R0). Parameter values for disease transmission were derived from previously published data; rates of entry, exit or transition between age groups were calculated based on our previous study, observational data, expert opinions and literature. With these parameter values the probability of a minor outbreak was estimated to be 10%, the probability of extinction was estimated as <0.001% and the expected time to extinction as more than 80 years. The probability of a minor outbreak and changes in prevalence were different when the index case was an adult cow compared to introduction by a heifer. Prediction of prevalences from MSI models fit the data satisfactorily. R0 was estimated as 9.5. The sensitivity analysis on R0 showed that all measures directed to reduce the transmission rate are potentially effective given operational control measures. An important prediction of these models is that, even in a relatively small, closed dairy herd, the time-scale for a BLV outbreak may be as long as several years and within-herd control of BLV requires intensive efforts.

A randomized study comparing filgrastim versus lenograstim versus molgramostim plus chemotherapy for peripheral blood progenitor cell mobilization.

We conducted a prospective randomized clinical trial to assess the mobilizing efficacy of filgrastim, lenograstim and molgramostim following a disease-specific chemotherapy regimen. Mobilization consisted of high-dose cyclophosphamide in 45 cases (44%), and cisplatin/ifosfamide/etoposide or vinblastine in 22 (21%), followed by randomization to either filgrastim or lenograstim or molgramostim at 5 microg/kg/day. One hundred and three patients were randomized, and 82 (79%) performed apheresis. Forty-four (43%) patients were chemonaive, whereas 59 (57%) were pretreated. A median number of one apheresis per patient (range, 1-3) was performed. The median number of CD34+ cells obtained after mobilization was 8.4 x 10(6)/kg in the filgrastim arm versus 5.8 x 10(6)/kg in the lenograstim arm versus 4.0 x 10(6)/kg in the molgramostim arm (P=0.1). A statistically significant difference was observed for the median number of days of growth factor administration in favor of lenograstim (12 days) versus filgrastim (13 days) and molgramostim (14 days) (P<0.0001) and for the subgroup of chemonaive patients (12 days) versus pretreated patients (14 days) (P<0.001). In conclusion, all three growth factors were efficacious in mobilizing peripheral blood progenitor cells with no statistically significant difference between CD34+ cell yield and the different regimens, and the time to apheresis is likely confounded by the different mobilization regimens.

Survival analysis on aggregate data to assess time to sero-conversion after experimental infection with Bovine Leukemia virus.

Bovine Leukemia virus (BLV) is a ubiquitous retrovirus that affects mainly cattle. Knowledge of the precise moment of infection is fundamental for identification and evaluation of factors related to BLV transmission. Systematic reviews and meta-analyses provide good evidence on the effects of medical interventions. The objectives were to estimate time to sero-conversion after experimental infection using data from retrieved literature and to detect factors that may influence the length of that interval using survival analysis on pooled data. An analysis using aggregate data from 36 studies totalling 438 observations was performed. From this, four sets were created and analysed by interval-censored accelerated failure time models (AFT) with different distributions (exponential, Weibull, log-logistic, lognormal and generalized gamma), and some variants of the Cox model (Andersen-Gill, smoothing splines) with and without a frailty effect. The AFT gamma model fit best and the estimated median time to sero-conversion in the null model was 57 days (95% confidence interval (CI): 49; 75) using all data and 47 days (95% CI: 39; 55) when only studies using experimental inoculation were considered. Some factors were consistently associated with time to sero-conversion. These included exposure by animal-to-animal contact (resulting in a seven-fold increase in time to sero-conversion compared to direct inoculation), diagnostic method to detect sero-conversion (time to sero-conversion was 1.4 times shorter when AGID was used compared to ELISA), and transmission by insect bites (biological media) delayed sero-conversion 2.3 times compared transmission via needles or other inanimate media. After fitting a frailty Cox model, results showed that sero-conversion in susceptible animals after infection using donors, in which presence of virus before the experiment started was confirmed, increased the hazard of sero-conversion two times in comparison with donors in which virus presence was not confirmed before start of the experiment. Inoculation with blood decreased the hazard 2.5 times in comparison with lymphocyte suspensions. Heterogeneity due to different research groups was also present. Finally, a Cox model with smoothing splines contained three variables: research group, route of inoculation and a non-linear spline for infective dose. In conclusion, it can be stated some factors that influence the time to sero-conversion were identified and quantified and that a moderate influence of research centre existed. These results may contribute to the estimation of the most probable times of infection in field conditions and in a better evaluation of control measures.

Misregulation of poly(ADP-ribose) polymerase-1 activity and cell type-specific loss of poly(ADP-ribose) synthesis in the cerebellum of aged rats.

Protein modification by ADP-ribose polymers is a common regulatory mechanism in eukaryotic cells and is involved in several aspects of brain physiology and physiopathology, including neurotransmission, memory formation, neurotoxicity, ageing and age-associated diseases. Here we show age-related misregulation of poly(ADP-ribose) synthesis in rat cerebellum as revealed by: (i) reduced poly(ADP-ribose) polymerase-1 (PARP-1) activation in response to enzymatic DNA cleavage, (ii) altered protein poly(ADP-ribosyl)ation profiles in isolated nuclei, and (iii) cell type-specific loss of poly(ADP-ribosyl)ation capacity in granule cell layer and Purkinje cells in vivo. In particular, although PARP-1 could be detected in virtually all granule cells, only a fraction of them appeared to be actively engaged in poly(ADP-ribose) synthesis and this fraction was reduced in old rat cerebellum. NAD(+), quantified in tissue homogenates, was essentially the same in the cerebellum of young and old rats suggesting that in vivo factors other than PARP-1 content and/or NAD(+) levels may be responsible for the age-associated lowering of poly(ADP-ribose) synthesis. Moreover, PARP-1 expression was substantially down-regulated in Purkinje cells of senescent rats.

Genetic diversity and spread of Bovine leukaemia virus isolates in Argentine dairy cattle.

Effective tools for use in control programmes against bovine leukaemia virus (BLV) infections require insight into the relationship between the variant structure of the bovine leukaemia virus and the spatial-temporal interaction of isolates and hosts. Our study showed the presence of two types of BLV isolates - Australian and Argentine - in dairy herds from various parts of Central Argentina; these isolates were characterised by RFLP on PCR amplicons, and some of them were confirmed by sequencing. One genotype (Argentine) was present in all herds, and the Australian genotype was found in two herds. Phylogenetic analysis indicated four clusters. The first cluster was composed of the Argentine isolates and one from Brazil; the second was composed of several isolates found in European countries and one from Brazil; the third cluster was composed of BLV isolates found in Japan and Germany; the fourth cluster included American and Australian isolates and those from other countries. The comparison of a number of synonymous and non-synonymous nucleotide substitutions using various BLV genes revealed purifying selection, suggesting that molecular evolution occurred under some functional constraint.

Relationships between total CD34+ cells reinfused, CD34+ subsets and engraftment kinetics in breast cancer patients.

BACKGROUND AND OBJECTIVE: The aim of the present study was to evaluate the correlation between the number of CD34+ cells transfused and the duration of hypoplasia, and the relationship between various CD34+ subsets (CD34+/33-; CD34+/38-; CD34+/ HLA-DR-; CD34+/Thy-1+) and engraftment kinetics in a series of patients with breast cancer treated with high doses of thiotepa and melphalan. DESIGN AND METHODS: We treated 42 consecutive patients: 19 in an adjuvant context (>= 4 positive axillary nodes) and 23 for metastatic disease. A combination of thiotepa 600 mg/m(2) and melphalan 140-160 mg/m(2) was administered as the conditioning regimen. All patients received peripheral blood progenitor cells (PBPC) and growth factors for hematopoietic rescue. RESULTS: In univariate analysis, we found a significant relationship between the number of CD34+ cells reinfused and the time to hematologic recovery and the duration of hospital stay. We observed an inverse correlation between the number of CD34+ cells reinfused and the units of platelets transfused. Cox multivariate analysis confirmed that the number of CD34+ cells reinfused is the most effective predictor of time to hematologic recovery. CFU-GM resulted to be a better predictor of the duration of hospitalization. INTERPRETATION AND CONCLUSIONS: We found a significant relationship between the number of PBPC reinfused and the time to hematologic recovery after high doses of thiotepa and melphalan. In our experience, the numbers of subsets of CD34+ cells infused did not give compared additional information to that provided by the total number of CD34+ cells infused.

Is there any difference in PBPC mobilization between cyclophosphamide plus G-CSF and G-CSF alone in patients with non-Hodgkin's Lymphoma?

We attempted to analyze whether the use of high-dose cyclophosphamide (CTX 7g/m2, group A) plus hematopoietic growth factor (G-CSF) or G-CSF alone (10 microg/Kg, group B) as a mobilizing regimen, could result in harvesting different numbers of CD34+ cells, committed progenitors and CD34+ cells subsets. The number of CD34+ cells considered as the target for each high-dose chemotherapy was > or = 2 x 10(6) /Kg/bw. Fifteen leukaphereses procedures were necessary in group A, while 16 procedures were performed in group B. We did not observe any difference between the two groups in terms of CD34+ cells/microl in the peripheral blood (117 vs 78; p = NS), whereas in the aphereses product we found a significant difference between the two groups of patients in terms of CD34+ cells (6.41 vs 2.89 x 10(6) /Kg/bw; p = .009), CFU-GM (82.5 vs 52.3 x 10(4) /Kg/bw; p = .04). Interestingly, we noted a different distribution of CD34+/33- cells between the 2 groups (mean value 39% vs 65%; p < .05), whereas we did not find any differences regarding CD34+/38-, CD34+/Thy1+, CD34+/HLADR-. The higher number of CFU-GM/Kg/bw collected in the former group did not translate into a superior plating efficiency (27.75 vs 30.29). Furthermore, we observed a strong correlation between CD34+ cells/microl in the peripheral blood and the total number of CD34+ cells in the leukaphereses product (r = 0.97), whereas this correlation was not found in group B (r = 0.15). In both groups of patients the number of CD34+ cells collected correlated well with CFU-GM (r = 0.93; r = 0.94), but definitely we did not observe any correlation between CD34+ cells/microl and CFU-GM in patients mobilized with G-CSF alone and this did not allow us to predict the harvest accurately. Finally, we evaluated the engraftment kinetics and we did not observe any statistically significant difference between the two groups of patients.

The PEN5 epitope identifies an oligodendrocyte precursor cell population and pilocytic astrocytomas.

PEN5 is a sulfated polylactosamine carbohydrate epitope first described in a subpopulation of mature natural killer cells. Here we report that it is also expressed in a developmentally regulated fashion in human and rat central nervous systems and that its protein carrier is P-selectin glycoprotein ligand-1 (PSGL-1), a ligand for selectins. In rat neural primary cultures, PEN5 is transiently and selectively expressed by oligodendrocyte precursor cells and marks the transition from proliferative to postmitotic stages. In concordance, in human central nervous system tumors, PEN5 is observed in a subset of oligodendrogliomas and in all pilocytic astrocytomas, a class of tumor of uncertain histogenesis. These data suggest that PEN5-PSGL-1 plays a role in the differentiation of oligodendrocytes and that pilocytic astrocytomas are likely to result from a dysregulation occurring in oligodendrocyte precursor cells at the crucial stage of exit from the cell cycle.

Paclitaxel and radiotherapy: sequence-dependent efficacy--a preclinical model.

The optimal sequence of a paclitaxel-radiation combination was investigated in vitro in two human colon adenocarcinoma cell lines, HT29 and LoVo. Three schedules of combined treatment were tested by clonogenic and flow cytometric assays. Paclitaxel was given 24 h prior to a single radiation shot (first schedule) or 24 h (second schedule) or 48 h (third schedule) before 3 days of concomitant radiation. Dose-response data were fit to a linear quadratic model, and mean inactivation dose and sensitizer enhanced ratio were calculated. In HT29 cells, the first and second schedule resulted in an additive effect, whereas a supraadditive interaction was observed with the third combination schedule. This effect was obtained with amounts of paclitaxel lower than IC50, which did not result in cell cycle perturbation, and with low radiation dose (2 Gy) that may be given in a clinical setting. LoVo cells were less sensitive to combined treatment than HT29 cells, switching from infraadditive (first and second schedule) to additive interaction (third schedule). Posttreatment recovery studies of third schedule showed a loss of cell survival in HT29 cells but not in LoVo cells. In contrast to LoVo cells, the third schedule in HT29 cells was able to induce perturbation of cell cycle kinetics, an effective impairment of DNA repair, and apoptotic cell death. HT29 and LoVo cells showed constitutional different characteristics: HT29 cells were more sensitive to paclitaxel exposure, less radiosensitive, and had a different cell cycle redistribution after radiation exposure than LoVo cells; moreover, HT29 cells showed a major propensity to undergo apoptosis. These results suggest that the radiosensitizing effect of paclitaxel was strictly schedule dependent, and the inhibition of DNA repair, cell cycle redistribution, and apoptosis could be the mechanisms for the induction of radiosensitization by paclitaxel.

Peripheral blood progenitor cell (PBPC) mobilization in heavily pretreated patients with germ cell tumors: a report of 34 cases.

The aim of the study was to evaluate peripheral blood progenitor cell mobilization by disease-specific chemotherapy in heavily pretreated patients with germ cell tumor (GCT), scheduled for high-dose chemotherapy. Thirty-four consecutive patients, 29 males and five females, with advanced GCT referred to our department for high-dose chemotherapy were evaluated retrospectively. Sixteen patients were mobilized by vinblastine 0.11 mg/kg on days 1 and 2, ifosfamide 1200 mg/m2 days 1-5 and cisplatin 20 mg/m2 days 1-5 (VeIP). In 10 patients, etoposide 75 mg/m2 days 1-5 was used instead of vinblastine (VIP), while in eight patients the mobilization was attempted by administering 7 g/m2 of cyclophosphamide. The choice of either etoposide or vinblastine was predicated upon which of these two drugs was associated with best results during premobilization chemotherapy. Cyclophosphamide was selected in patients refractory to previous cisplatin-based salvage chemotherapy. Twenty-five out of 34 patients underwent a successful PBPC collection. In 17 of them one leukapheresis procedure was sufficient to collect the target number of CD34+ cells, while in eight patients a double procedure was necessary. Altogether 33 aphereses were performed in 25 patients. In nine patients leukapheresis was not attempted. This was due to the fact that the chemotherapy failed to mobilize the target number of CD34+ cells in eight of them, treated with the VeIP mobilizing regimen, while one patient treated with high-dose cyclophosphamide rapidly progressed during therapy and for this reason leukapheresis was not undertaken. In conclusion, in heavily pretreated patients with GCT, PBPC mobilization is feasible by a further course of salvage chemotherapy. The choice of either etoposide (VIP) or vinblastine (VeIP) can be predicated upon which of these two drugs was associated with best results during premobilization chemotherapy. In our hands, VeIP seems to be less satisfactory as mobilizing treatment than VIP, possibly due to a superior number of premobilization courses of chemo therapy in some patients. Moreover, high-dose cyclophosphamide remains a good alternative for mobilizing patients refractory to salvage chemotherapy.

Cytofluorimetric evaluation of DNA ploidy in the diagnosis of bladder cancer.

OBJECTIVE: The aim of the study is to investigate the relationship between urinary cytology, traditional indexes of malignancy of bladder carcinoma and DNA-ploidy (diploid, near-diploid, aneuploid). METHODS: 52 specimens of bladder cancers (transitional cell carcinoma) were obtained from 46 patients at TURB and from 6 patients at radical cystectomy. In every specimen the nuclear content of DNA was investigated using the cytofluorimetric method. Cells were processed in standard fashion for flow cytometry with propidium iodide staining; cellular suspension was obtained mechanically. Peripheral blood lymphocytes were used as diploid standard. Bladder cytology was performed in every patient. RESULTS: A relationship between DNA-ploidy and histological malignancy was observed. The largest portion of near-diploid neoplasm was observed in stage T1, grade G2 malignancies. In some cases negative bladder cytology occurred together with aneuploid DNA content, whilst in other cases positive bladder cytology occurred together with diploid DNA content. In consequence there is not always a relationship between bladder cytology and DNA-ploidy. CONCLUSIONS: Since observed correlations may point out some neoplasms with particular biological behaviour, follow-up of near-diploid malignancies is of great interest.