Clinical presentation and time-course of postoperative venous thromboembolism: Results from the RIETE Registry

There is little literature about the clinical presentation and time-course of postoperative venous thromboembolism (VTE) in different surgical procedures. RIETE is an ongoing, prospective registry of consecutive patients with objectively confirmed, symptomatic acute VTE. In this analysis, we analysed the baseline characteristics, thromboprophylaxis and therapeutic patterns, time-course, and three-month outcome of all patients with postoperative VTE. As of January 2006, there were 1,602 patients with postoperative VTE in RIETE: 393 (25%) after major orthopaedic surgery (145 elective hip arthroplasty, 126 knee arthroplasty, 122 hip fracture); 207 (13%) after cancer surgery; 1,002 (63%) after other procedures. The percentage of patients presenting with clinically overt pulmonary embolism (PE) (48%, 48%, and 50% respectively), the average time elapsed from surgery to VTE (22 +/- 16, 24 +/- 16, and 21 +/- 15 days, respectively), and the three-month incidence of fatal PE (1.3%, 1.4%, and 0.8%, respectively), fatal bleeding (0.8%, 1.0%, and 0.2%, respectively), or major bleeding (2.3%, 2.9%, and 2.8%, respectively) were similar in the three groups. However, the percentage of patients who had received thromboprophylaxis (96%, 76% and 52%, respectively), the duration of prophylaxis (17 +/- 9.6, 13 +/- 8.9, and 12 +/- 11 days, respectively) and the mean daily doses of low-molecular-weight heparin (4,252 +/- 1,016, 3,260 +/- 1,141, and 3,769 +/- 1,650 IU, respectively), were significantly lower in those undergoing cancer surgery or other procedures. In conclusion, the clinical presentation, time-course, and three-month outcome of VTE was similar among the different subgroups of patients, but the use of prophylaxis in patients undergoing cancer surgery or other procedures was suboptimal.

Suture repair of umbilical hernia during caesarean section: a case-control study.

PURPOSE: The objective of this study was to investigate the additional burdens in terms of pain, prolongation of surgery and morbidity which is added to elective caesarean section if umbilical hernia suture repair is performed simultaneously. Secondly, patient's satisfaction and hernia recurrence rate were assessed. METHODS: Consecutive women with symptomatic umbilical hernia undergoing internal or external suture repair during elective caesarean were included in this retrospective cohort-control study. Data on post-operative pain, duration of surgery and morbidity of a combined procedure were collected. These patients were matched 1:10 to women undergoing caesarean section only. Additionally, two subgroups were assessed separately: external and internal suture hernia repair. These subgroups were compared for patient's satisfaction, cosmesis, body image and recurrence rate. RESULTS: Fourteen patients with a mean age of 37 years were analysed. Internal suture repair (n = 7) prolonged caesarean section by 20 min (p = 0.001) and external suture repair (n = 7) by 34 min (p < 0.0001). Suture repair did not increase morphine use (0.38 ± 0.2 vs. 0.4 ± 02 mg/kg body weight), had no procedure-related morbidity and prolonged hospitalization by 0.5 days (p = 0.01). At a median follow-up of 37 (5-125) months, two recurrences in each surgical technique, internal and external suture repair, occurred (28 %). Body image and cosmesis score showed a higher level of functioning in internal suture repair (p = 0.02; p = 0.04). DISCUSSION: Despite a high recurrence rate, internal suture repair of a symptomatic umbilical hernia during elective caesarean section should be offered to women if requested. No additional morbidity or scar is added to caesarean section. Internal repair is faster, and cosmetic results are better, additional skin or fascia dissection is avoided, and it seems to be as effective as an external approach. Yet, women must be informed on the high recurrence rate.

Classification of immature mosquito species according to characteristics of the larval habitat in the subtropical province of Chaco, Argentina

To classify mosquito species based on common features of their habitats, samples were obtained fortnightly between June 2001-October 2003 in the subtropical province of Chaco, Argentina. Data on the type of larval habitat, nature of the habitat (artificial or natural), size, depth, location related to sunlight, distance to the neighbouring houses, type of substrate, organic material, vegetation and algae type and their presence were collected. Data on the permanence, temperature, pH, turbidity, colour, odour and movement of the larval habitat's water were also collected. From the cluster analysis, three groups of species associated by their degree of habitat similarity were obtained and are listed below. Group 1 consisted of Aedes aegypti. Group 2 consisted of Culex imitator, Culex davisi, Wyeomyia muehlensi and Toxorhynchites haemorrhoidalis separatus. Within group 3, two subgroups are distinguished: A (Psorophora ferox, Psorophora cyanescens, Psorophora varinervis, Psorophora confinnis, Psorophora cingulata, Ochlerotatus hastatus-oligopistus, Ochlerotatus serratus, Ochlerotatus scapularis, Culex intrincatus, Culex quinquefasciatus, Culex pilosus, Ochlerotatus albifasciatus, Culex bidens) and B (Culex maxi, Culex eduardoi, Culex chidesteri, Uranotaenia lowii, Uranotaenia pulcherrima, Anopheles neomaculipalpus, Anopheles triannulatus, Anopheles albitarsis, Uranotaenia apicalis, Mansonia humeralis and Aedeomyia squamipennis). Principal component analysis indicates that the size of the larval habitats and the presence of aquatic vegetation are the main characteristics that explain the variation among different species. In contrast, water permanence is second in importance. Water temperature, pH and the type of larval habitat are less important in explaining the clustering of species.

Acute imaging does not improve ASTRAL score's accuracy despite having a prognostic value.

BACKGROUND: The ASTRAL score was recently shown to reliably predict three-month functional outcome in patients with acute ischemic stroke. AIM: The study aims to investigate whether information from multimodal imaging increases ASTRAL score's accuracy. METHODS: All patients registered in the ASTRAL registry until March 2011 were included. In multivariate logistic-regression analyses, we added covariates derived from parenchymal, vascular, and perfusion imaging to the 6-parameter model of the ASTRAL score. If a specific imaging covariate remained an independent predictor of three-month modified Rankin score > 2, the area-under-the-curve (AUC) of this new model was calculated and compared with ASTRAL score's AUC. We also performed similar logistic regression analyses in arbitrarily chosen patient subgroups. RESULTS: When added to the ASTRAL score, the following covariates on admission computed tomography/magnetic resonance imaging-based multimodal imaging were not significant predictors of outcome: any stroke-related acute lesion, any nonstroke-related lesions, chronic/subacute stroke, leukoaraiosis, significant arterial pathology in ischemic territory on computed tomography angiography/magnetic resonance angiography/Doppler, significant intracranial arterial pathology in ischemic territory, and focal hypoperfusion on perfusion-computed tomography. The Alberta Stroke Program Early CT score on plain imaging and any significant extracranial arterial pathology on computed tomography angiography/magnetic resonance angiography/Doppler were independent predictors of outcome (odds ratio: 0·93, 95% CI: 0·87-0·99 and odds ratio: 1·49, 95% CI: 1·08-2·05, respectively) but did not increase ASTRAL score's AUC (0·849 vs. 0·850, and 0·8563 vs. 0·8564, respectively). In exploratory analyses in subgroups of different prognosis, age or stroke severity, no covariate was found to increase ASTRAL score's AUC, either. CONCLUSIONS: The addition of information derived from multimodal imaging does not increase ASTRAL score's accuracy to predict functional outcome despite having an independent prognostic value. More selected radiological parameters applied in specific subgroups of stroke patients may add prognostic value of multimodal imaging.

Granulocyte colony-stimulating factor in the treatment of high-risk febrile neutropenia: a multicenter randomized trial.

BACKGROUND Granulocyte colony-stimulating factors (G-CSFs) have been shown to help prevent febrile neutropenia in certain subgroups of cancer patients undergoing chemotherapy, but their role in treating febrile neutropenia is controversial. The purpose of our study was to evaluate-in a prospective multicenter randomized clinical trial-the efficacy of adding G-CSF to broad-spectrum antibiotic treatment of patients with solid tumors and high-risk febrile neutropenia. METHODS A total of 210 patients with solid tumors treated with conventional-dose chemotherapy who presented with fever and grade IV neutropenia were considered to be eligible for the trial. They met at least one of the following high-risk criteria: profound neutropenia (absolute neutrophil count <100/mm(3)), short latency from previous chemotherapy cycle (<10 days), sepsis or clinically documented infection at presentation, severe comorbidity, performance status of 3-4 (Eastern Cooperative Oncology Group scale), or prior inpatient status. Eligible patients were randomly assigned to receive the antibiotics ceftazidime and amikacin, with or without G-CSF (5 microg/kg per day). The primary study end point was the duration of hospitalization. All P values were two-sided. RESULTS Patients randomly assigned to receive G-CSF had a significantly shorter duration of grade IV neutropenia (median, 2 days versus 3 days; P = 0.0004), antibiotic therapy (median, 5 days versus 6 days; P = 0.013), and hospital stay (median, 5 days versus 7 days; P = 0.015) than patients in the control arm. The incidence of serious medical complications not present at the initial clinical evaluation was 10% in the G-CSF group and 17% in the control group (P = 0.12), including five deaths in each study arm. The median cost of hospital stay and the median overall cost per patient admission were reduced by 17% (P = 0.01) and by 11% (P = 0.07), respectively, in the G-CSF arm compared with the control arm. CONCLUSIONS Adding G-CSF to antibiotic therapy shortens the duration of neutropenia, reduces the duration of antibiotic therapy and hospitalization, and decreases hospital costs in patients with high-risk febrile neutropenia.

Phase III trial of consolidation therapy with yttrium-90-ibritumomab tiuxetan compared with no additional therapy after first remission in advanced follicular lymphoma.

PURPOSE: We conducted an international, randomized, phase III trial to evaluate the efficacy and safety of consolidation with yttrium-90 ((90)Y)-ibritumomab tiuxetan in patients with advanced-stage follicular lymphoma in first remission. PATIENTS AND METHODS: Patients with CD20(+) stage III or IV follicular lymphoma, who achieved a complete response (CR)/unconfirmed CR (CRu) or partial response (PR) after first-line induction treatment, were randomly assigned to receive (90)Y-ibritumomab tiuxetan (rituximab 250 mg/m(2) on day -7 and day 0 followed on day 0 by (90)Y-ibritumomab tiuxetan 14.8 MBq/kg; maximum of 1,184 MBq) or no further treatment (control). The primary end point was progression-free survival (PFS), which was calculated from the time of random assignment. RESULTS: A total of 414 patients (consolidation, n = 208; control, n = 206) were enrolled at 77 centers. (90)Y-ibritumomab tiuxetan consolidation significantly prolonged median PFS (after a median observation time of 3.5 years) in all patients (36.5 v 13.3 months in control arm; hazard ratio [HR] = 0.465; P &lt; .0001) and regardless of whether patients achieved PR (29.3 v 6.2 months in control arm; HR = 0.304; P &lt; .0001) or CR/CRu (53.9 v 29.5 months in control arm; HR = 0.613; P = .0154) after induction treatment. Median PFS with consolidation was prolonged in all Follicular Lymphoma International Prognostic Index risk subgroups. After (90)Y-ibritumomab tiuxetan consolidation, 77% of patients in PR after induction converted to CR/CRu, resulting in a final CR rate of 87%. The most common toxicity with (90)Y-ibritumomab tiuxetan was hematologic, and grade 3 or 4 infections occurred in 8% of patients. CONCLUSION: Consolidation of first remission with (90)Y-ibritumomab tiuxetan in advanced-stage follicular lymphoma is highly effective with no unexpected toxicities, prolonging PFS by 2 years and resulting in high PR-to-CR conversion rates regardless of type of first-line induction treatment.

Determinants of non- response to a second assessment of lifestyle factors and body weight in the EPIC-PANACEA study.

BACKGROUND This paper discusses whether baseline demographic, socio-economic, health variables, length of follow-up and method of contacting the participants predict non-response to the invitation for a second assessment of lifestyle factors and body weight in the European multi-center EPIC-PANACEA study. METHODS Over 500.000 participants from several centers in ten European countries recruited between 1992 and 2000 were contacted 2-11 years later to update data on lifestyle and body weight. Length of follow-up as well as the method of approaching differed between the collaborating study centers. Non-responders were compared with responders using multivariate logistic regression analyses. RESULTS Overall response for the second assessment was high (81.6%). Compared to postal surveys, centers where the participants completed the questionnaire by phone attained a higher response. Response was also high in centers with a short follow-up period. Non-response was higher in participants who were male (odds ratio 1.09 (confidence interval 1.07; 1.11), aged under 40 years (1.96 (1.90; 2.02), living alone (1.40 (1.37; 1.43), less educated (1.35 (1.12; 1.19), of poorer health (1.33 (1.27; 1.39), reporting an unhealthy lifestyle and who had either a low (<18.5 kg/m2, 1.16 (1.09; 1.23)) or a high BMI (>25, 1.08 (1.06; 1.10); especially ≥30 kg/m2, 1.26 (1.23; 1.29)). CONCLUSIONS Cohort studies may enhance cohort maintenance by paying particular attention to the subgroups that are most unlikely to respond and by an active recruitment strategy using telephone interviews.

Association analysis of human leukocyte antigen class II (DRB1) alleles with leprosy in individuals from São Luís, state of Maranhão, Brazil

Epidemiological studies have demonstrated that the variability of the clinical response to infection caused by Mycobacterium leprae is associated with host genetic factors. The present study investigated the frequency of human leukocyte antigen (HLA) class II (DRB1) alleles in patients with leprosy from São Luís, Maranhão, Brazil. A case-control study was performed in 85 individuals with leprosy and 85 healthy subjects. All samples were analysed via polymerase chain reaction-sequence specific oligonucleotide probes. The HLA-DRB1*16 allele showed a higher frequency in the group with leprosy [(9.41% vs. 4.12%) odds ratio (OR) = 2.41 95% confidence interval (CI) (0.96-6.08) p = 0.05], whereas the HLA-DRB1*11 allele was less frequent in the group with leprosy [(6.47% vs. 11.76%) OR = 0.51 95% CI (0.23-1.12) p = 0.09]. The frequency of HLA-DRB1* alleles between the control group and leprosy patient subgroups presenting different forms of the disease showed that the HLA-DRB1*16 (16.13% vs. 8.24%, OR = 4.10, CI = 1.27-13.27, p = 0.010) and HLA-DRB1*14 (5% vs. 3.53%, OR = 4.63, CI = 1.00-21.08, p = 0.032) alleles were significantly more frequent in patients with different clinical subtypes of leprosy. The sample size was a limitation in this study. Nevertheless, the results demonstrated the existence of a genetic susceptibility associated with the clinical forms of leprosy. The low frequency of the HLA-DRB1*11 allele should be further studied to investigate the possible protective effect of this allele.

Characteristics of eyes with secondary loss of visual acuity receiving variable dosing ranibizumab for neovascular age-related macular degeneration.

PURPOSE: The aim of this work is to investigate the characteristics of eyes failing to maintain visual acuity (VA) receiving variable dosing ranibizumab for neovascular age-related macular degeneration (nAMD) after three initial loading doses. METHODS: A consecutive series of patients with nAMD, who, after three loading doses of intravitreal ranibizumab (0.5 mg each), were re-treated for fluid seen on optical coherence tomography. After exclusion of eyes with previous treatment, follow-up less than 12 months, or missed visits, 99 patients were included in the analysis. The influence of baseline characteristics, initial VA response, and central retinal thickness (CRT) fluctuations on the VA stability from month 3 to month 24 were analyzed using subgroups and multiple regression analyses. RESULTS: Mean follow-up duration was 21.3 months (range 12-40 months, 32 patients followed-up for ≥24 months). Secondary loss of VA (loss of five letters or more) after month 3 was seen in 30 patients (mean VA improvement from baseline +5.8 letters at month 3, mean loss from baseline -5.3 letters at month 12 and -9.7 at final visit up to month 24), while 69 patients maintained vision (mean gain +8.9 letters at month 3, +10.4 letters at month 12, and +12.8 letters at final visit up to month 24). Secondary loss of VA was associated with the presence of pigment epithelial detachment (PED) at baseline (p 0.01), but not with baseline fibrosis/atrophy/hemorrhage, CRT fluctuations, or initial VA response. Chart analysis revealed additional individual explanations for the secondary loss of VA, including retinal pigment epithelial tears, progressive fibrosis, and atrophy. CONCLUSIONS: Tissue damage due to degeneration of PED, retinal pigment epithelial tears, progressive fibrosis, progressive atrophy, or massive hemorrhage, appears to be relevant in causing secondary loss of VA despite vascular endothelial growth factor suppression. PED at baseline may represent a risk factor.

Characterization of SKI-1/S1P-mediated processing of Arenavirus glycoprotein precursors

Arenaviruses are rodent-born world-wide distributed negative strand RNA viruses that comprise a number of important human pathogens including Lassa virus (LASV) which causes more than 3 00'000 infections annually in Western Africa. Lymphocytic choriomeningitis virus (LCMV) is the prototypic member of the arenavirus family, which is divided in two major subgroups according to serological properties and geographical distribution, the Old World and New World arenaviruses. The envelope glycoprotein precursors (GPCs) of arenaviruses have to undergo proteolytic processing to acquire biological function and to be incorporated into progeny virions. A cellular enzyme is responsible for this processing: the Subtilisin Kexin Isozyme-1 or Site-1 protease (SKI- 1/S1P). In this thesis we have studied the relationship between SKI-1/S1P and the envelope GPs of arenaviruses. In a first project, we investigated the molecular interactions between SKI-1/SIP and arenavirus GPCs. Using SKI-1/SIP mutants, we confirmed previously published observations locating LCMV GPC and LASV GPC processing in the Late Golgi/TGN and ER/cis-Golgi, respectively. A single mutation in the cleavage site of LCMV was sufficient to re-locate SKI- 1/SIP-mediated processing from the late Golgi/TGN to the ER/cis-Golgi. We then demonstrated that the transmembrane domain, the C-terminal tail and the phosphorylation sites of SKI-1/S1P are dispensable for GPC processing. Additionally we identified a SKI- 1/S1P mutant defective for autoprocessing at site Β, B' that was selectively impaired in processing of viral GPCs but not cellular substrates. We also showed that a soluble variant of SKI-1/SIΡ was unable to cleave envelope GPs at the cell surface when added in the culture medium. This study highlighted a new target for small molecule inhibitors that would specifically impair GPC but not cellular substrate processing. In a second project, we identified and characterized two residues: LASV GPC Y253 and SKI-1/S1P Y285 that are important for the SKI-1/SIP-mediated LASV GPC cleavage. An alignment of GPC sequences revealed a conserved aromatic residue in P7 position in the GPCs of Old World and Clade C of New World arenaviruses. Mutations in GPC at position P7 impaired processing efficiency. In SKI-1/S1P, mutating Y285 into A negatively affected processing of substrates containing aromatic residues in P7, without affecting others. This property could be used to develop specific drugs targeting SKI-1/SIP-mediated cleavage of LASV GPC without affecting cellular substrates. As a third project we studied the role of the SKI-1/SIP-mediated processing and the unusual stable signal peptide (SSP) for the folding and secretion of soluble forms of the ectodomain of LASV and LCMV glycoproteins. We provide evidence that the transmembrane domain and the cytosolic tail are crucial for the stability of the prefusion conformation of arenavirus GP and that the SSP is required for transport and processing of full-length GP, but not the soluble ectodomain per se. Taken together, these results will lead to a better understanding of the complex interactions between arenavirus GPCs and SKI-1/S IP, paving the avenue for the development of novel anti-arenaviral therapeutics. - Les Arenavirus sont des virus à ARN négatif distribués mondialement et portés par les rongeurs. Cette famille de virus comprend des virus hautement pathogènes pour l'homme comme le virus de Lassa (LASV) qui cause plus de 300Ό00 infections par année en Afrique de l'Ouest. Le virus de la chorioméningite lymphocytaire (LCMV) est le représentant de cette famille qui est divisée en deux sous-groupes selon des critères sérologiques et de distributions géographiques: arenavirus du Nouveau et de l'Ancien monde. Les glycoprotéines d'enveloppe de ces virus (GPCs) doivent être clivées pour être incorporées dans le virus et ainsi lui permettre d'être infectieux. Une enzyme cellulaire est responsable de ce clivage : la Subtilisin Kexin Isozyme-1 ou protéase Site-1 (SKI-l/SlP). Dans cette thèse, nous avons étudié la relation entre cette enzyme cellulaire et les GPs des arenavirus. Dans un premier temps, nous avons étudié les interactions moléculaires entre SKI- 1/S1P et GPC. A l'aide de mutants de SKI-l/SlP, nous avons confirmé des résultats précédemment publiés montrant que les glycoprotéines d'enveloppe de LASV sont clivés dans le réticulum endoplasmique/cis-Golgi alors que celles de LCMV sont clivées dans le Golgi tardif/TGN. Une seule mutation dans le site de clivage de la glycoprotéine de LCMV est suffisante pour changer le compartiment cellulaire dans lequel est clivée cette glycoprotéine. Ensuite, nous avons démontré que le domaine transmembranaire, la partie cytosolique C-terminale ainsi que les sites de phosphorylations de cette enzyme ne sont pas indispensables pour permettre le clivage de GPC. De plus, nous avons identifié un mutant de SKI-l/SlP dans lequel Γ autoprocessing au site B,B' est impossible, incapable de cliver GPC mais toujours pleinement fonctionnelle envers ses substrats cellulaires. Nous avons également démontré qu'une forme soluble de SKI-l/SlP ajoutée dans le milieu de culture n'est pas capable de couper GPC à la surface de la cellule. Cette étude a défini une nouvelle cible potentielle pour un médicament qui inhiberait le clivage des glycoprotéines des arenavirus sans affecter les processus normaux de la cellule. Dans un second project, nous avons identifié deux acides aminés, LASV GPC Y253 et SKI-l/SlP Y285, qui sont important pour le clivage de LASV GPC. Un alignement des séquences de clivage des GPCs a montré qu'un résidu aromatique est conservé en position P7 du site de clivage chez tous les arenavirus de l'Ancien monde et dans le clade C des arenavirus du Nouveau monde. Une mutation de cet acide aminée dans GPC réduit l'efficacité de clivage par SKI-l/SlP. Mutation de la tyrosine 285 de SKI-l/SlP en alanine affecte négativement le clivage des substrats contenant un résidu aromatique en position P7 sans affecter les autres. Cette propriété pourrait être utilisée pour le développement de médicaments spécifiques ciblant le clivage de GPC. Finalement, nous avons étudié le rôle du processing accomplit par SKI-l/SlP et du signal peptide pour le pliage et la sécrétion de formes solubles des glycoprotéines de LASV et LCMV. Nous avons montré que le domaine transmembranaire et la partie cytosolique de GP sont crucials pour la stabilité de la conformation pre-fusionnelle des GPs et que SSP est nécessaire pour le transport et le processing de GP, mais pas de son ecto-domaine soluble. En conclusion, les résultats obtenus durant cette thèse permettrons de mieux comprendre les interactions complexes entre SKI-l/SlP et les glycoprotéines des arenavirus, ouvrant le chemin pour le développement de nouveaux médicaments anti-arénaviraux.

Genetic Polymorphisms and Susceptibility to Fungal Infections

Invasive fungal infections (IFI) are life-threatening diseases that are of particular concern in specific debilitated or immunosuppressed populations. Invasive candidiasis (IC) is the most frequent of the IFI, being one of the major causes of nosocomial bloodstream infection and a feared complication in patients with recurrent gastrointestinal surgery or prolonged stay in the intensive-care unit [1,2]. Patients with hematological malignancies or prolonged chemotherapy-induced neutropenia, and those with allogeneic hematopoietic stem cell transplantation (allo-HSCT), represent the groups at highest risk for developing invasive aspergillosis (IA), which is associated with a high mortality rate despite the increasing availability of antifungal therapies [3,4]. An increasing incidence of IA has also been reported in non-neutropenic immunosuppressed populations such as solid-organ transplant recipients or steroid-treated patients with chronic pulmonary diseases [5]. Early diagnosis of IFI is crucial for improving chances of survival [6], but is particularly challenging owing to the lack of reliable diagnostic methods [7,8]. Significant efforts during the last few decades have focused on the prevention of these severe complications. Antifungal prophylaxis in high-risk patients has been shown to reduce the incidence of IA in patients with onco-hematological malignancies [9] and that of IC in surgical intensive-care unit patients [10]. However, its widespread use raises concerns about costs, toxicity, and the risk of emergence of resistant fungal species such as non-Aspergillus moulds or non-albicansCandida spp. [4,11,12]. Prophylactic strategies usually rely on the identification of host risk factors resulting from clinical conditions (type and duration of immunosuppression, underlying diseases, and extrinsic interventions) [8,13]. Recent advances in the field of immunogenetics may change our perspective of, and approach to, preventive strategies with the identification of subgroups of patients exhibiting a genetic predisposition to IFI.

PARP inhibition attenuates histopathological lesion in ischemia/reperfusion renal mouse model after cold prolonged ischemia.

We test the hypothesis that PARP inhibition can decrease acute tubular necrosis (ATN) and other renal lesions related to prolonged cold ischemia/reperfusion (IR) in kidneys preserved at 4°C in University of Wisconsin (UW) solution. Material and Methods. We used 30 male Parp1(+/+) wild-type and 15 male Parp1(0/0) knockout C57BL/6 mice. Fifteen of these wild-type mice were pretreated with 3,4-dihydro-5-[4-(1-piperidinyl)butoxyl]-1(2H)-isoquinolinone (DPQ) at a concentration of 15 mg/kg body weight, used as PARP inhibitor. Subgroups of mice were established (A: IR 45 min/6 h; B: IR + 48 h in UW solution; and C: IR + 48 h in UW solution plus DPQ). We processed samples for morphological, immunohistochemical, ultrastructural, and western-blotting studies. Results. Prolonged cold ischemia time in UW solution increased PARP-1 expression and kidney injury. Preconditioning with PARP inhibitor DPQ plus DPQ supplementation in UW solution decreased PARP-1 nuclear expression in renal tubules and renal damage. Parp1(0/0) knockout mice were more resistant to IR-induced renal lesion. In conclusion, PARP inhibition attenuates ATN and other IR-related renal lesions in mouse kidneys under prolonged cold storage in UW solution. If confirmed, these data suggest that pharmacological manipulation of PARP activity may have salutary effects in cold-stored organs at transplantation.

Use of Two-Part Regression Calibration Model to Correct for Measurement Error in Episodically Consumed Foods in a Single-Replicate Study Design: EPIC Case Study.

In epidemiologic studies, measurement error in dietary variables often attenuates association between dietary intake and disease occurrence. To adjust for the attenuation caused by error in dietary intake, regression calibration is commonly used. To apply regression calibration, unbiased reference measurements are required. Short-term reference measurements for foods that are not consumed daily contain excess zeroes that pose challenges in the calibration model. We adapted two-part regression calibration model, initially developed for multiple replicates of reference measurements per individual to a single-replicate setting. We showed how to handle excess zero reference measurements by two-step modeling approach, how to explore heteroscedasticity in the consumed amount with variance-mean graph, how to explore nonlinearity with the generalized additive modeling (GAM) and the empirical logit approaches, and how to select covariates in the calibration model. The performance of two-part calibration model was compared with the one-part counterpart. We used vegetable intake and mortality data from European Prospective Investigation on Cancer and Nutrition (EPIC) study. In the EPIC, reference measurements were taken with 24-hour recalls. For each of the three vegetable subgroups assessed separately, correcting for error with an appropriately specified two-part calibration model resulted in about three fold increase in the strength of association with all-cause mortality, as measured by the log hazard ratio. Further found is that the standard way of including covariates in the calibration model can lead to over fitting the two-part calibration model. Moreover, the extent of adjusting for error is influenced by the number and forms of covariates in the calibration model. For episodically consumed foods, we advise researchers to pay special attention to response distribution, nonlinearity, and covariate inclusion in specifying the calibration model.

PARP inhibition attenuates histopathological lesion in ischemia/reperfusion renal mouse model after cold prolonged ischemia.

We test the hypothesis that PARP inhibition can decrease acute tubular necrosis (ATN) and other renal lesions related to prolonged cold ischemia/reperfusion (IR) in kidneys preserved at 4°C in University of Wisconsin (UW) solution. Material and Methods. We used 30 male Parp1(+/+) wild-type and 15 male Parp1(0/0) knockout C57BL/6 mice. Fifteen of these wild-type mice were pretreated with 3,4-dihydro-5-[4-(1-piperidinyl)butoxyl]-1(2H)-isoquinolinone (DPQ) at a concentration of 15 mg/kg body weight, used as PARP inhibitor. Subgroups of mice were established (A: IR 45 min/6 h; B: IR + 48 h in UW solution; and C: IR + 48 h in UW solution plus DPQ). We processed samples for morphological, immunohistochemical, ultrastructural, and western-blotting studies. Results. Prolonged cold ischemia time in UW solution increased PARP-1 expression and kidney injury. Preconditioning with PARP inhibitor DPQ plus DPQ supplementation in UW solution decreased PARP-1 nuclear expression in renal tubules and renal damage. Parp1(0/0) knockout mice were more resistant to IR-induced renal lesion. In conclusion, PARP inhibition attenuates ATN and other IR-related renal lesions in mouse kidneys under prolonged cold storage in UW solution. If confirmed, these data suggest that pharmacological manipulation of PARP activity may have salutary effects in cold-stored organs at transplantation.

MDM2 and CDK4 immunohistochemistry is a valuable tool in the differential diagnosis of low-grade osteosarcomas and other primary fibro-osseous lesions of the bone.

Low-grade osteosarcoma is a rare malignancy that may be subdivided into two main subgroups on the basis of location in relation to the bone cortex, that is, parosteal osteosarcoma and low-grade central osteosarcoma. Their histological appearance is quite similar and characterized by spindle cell stroma with low-to-moderate cellularity and well-differentiated anastomosing bone trabeculae. Low-grade osteosarcomas have a simple genetic profile with supernumerary ring chromosomes comprising amplification of chromosome 12q13-15, including the cyclin-dependent kinase 4 (CDK4) and murine double-minute type 2 (MDM2) gene region. Low-grade osteosarcoma can be confused with fibrous and fibro-osseous lesions such as fibromatosis and fibrous dysplasia on radiological and histological findings. We investigated MDM2-CDK4 immunohistochemical expression in a series of 72 low-grade osteosarcomas and 107 fibrous or fibro-osseous lesions of the bone or paraosseous soft tissue. The MDM2-CDK4 amplification status of low-grade osteosarcoma was also evaluated by comparative genomic hybridization array in 18 cases, and the MDM2 amplification status was evaluated by fluorescence in situ hybridization or quantitative real-time polymerase chain reaction in 31 cases of benign fibrous and fibro-osseous lesions. MDM2-CDK4 immunostaining and MDM2 amplification by fluorescence in situ hybridization or quantitative real-time polymerase chain reaction were investigated in a control group of 23 cases of primary high-grade bone sarcoma, including 20 conventional high-grade osteosarcomas, two pleomorphic spindle cell sarcomas/malignant fibrous histiocytomas and one leiomyosarcoma. The results showed that MDM2 and/or CDK4 immunoreactivity was present in 89% of low-grade osteosarcoma specimens. All benign fibrous and fibro-osseous lesions and the tumors of the control group were negative for MDM2 and CDK4. These results were consistent with the MDM2 and CDK4 amplification results. In conclusion, immunohistochemical expression of MDM2 and CDK4 is specific and provides sensitive markers for the diagnosis of low-grade osteosarcomas, helping to differentiate them from benign fibrous and fibro-osseous lesions, particularly in cases with atypical radio-clinical presentation and/or limited biopsy samples.