Systematic mapping review of interventions to prevent blood loss, infection and relapse in orthognathic surgery

BACKGROUND

This systematic mapping review aims to identify, describe, and organize the currently available evidence in systematic reviews (SR) and primary studies regarding orthognathic surgery (OS) co-interventions and surgical modalities, focusing on the outcomes blood loss, infection and relapse.

MATERIAL AND METHODS

A comprehensive search strategy was performed to identify all SRs, randomized controlled trials and observational studies that evaluate surgical modalities and perioperative co-interventions in OS that evaluate the outcomes blood loss, infection and relapse, regardless of language or publication date. Searches were conducted in MEDLINE, EMBASE, Epistemonikos, Lilacs, Web of Science, and CENTRAL. In addition, grey literature was screened.

RESULTS

27 SRs and 150 primary studies fulfilled the inclusion criteria, 91 from SRs, and 59 from our search strategy. Overall, the quality of the SRs was graded as "Critically low," and only two SRs were rated as "High" quality. 11 PICO questions were extracted from SRs and 31 from primary studies, which focused on osteosynthesis methods, surgical cutting devices, use of antibiotics, and induced hypotension. In addition, evidence bubble maps for each outcome were created to analyze in a visual manner the existing evidence.

CONCLUSIONS

Future primary and secondary high-quality research should be addressed focused on the eight knowledge gaps identified in this mapping review. We concluded that the evidence mapping approach is a practical methodology for organizing the current evidence and identifying knowledge gaps in OS, helping to reduce research waste and canalize future efforts in developing studies for unsolved questions.

Effect of antibiotic prophylaxis for preventing infectious complications following impacted mandibular third molar surgery. A randomized controlled trial

Background

The objective of this study was to determine the effect of antibiotic prophylaxis in preventing postoperative infections after extraction of impacted mandibular third molars.

Material and Methods

A Parallel-group, randomized, blind, placebo-controlled trial was performed. 154 patients were randomly allocated to 2 groups; experimental (n=77) receiving 2g amoxicillin 1 hour prior to surgery and control (n=77) receiving placebo. Primary outcome was postoperative infections and secondary outcome was the need for rescue analgesia.

Results

4.5% of patients developed postoperative infections, five patients of the control group (4 alveolar osteitis, 1 surgical site infection) and two of the experimental group (1 alveolar osteitis, 1 surgical site infection). Difference between groups was not statistically significant, RR=0.4 (95%CI 0.08-1.99, 𝘱=0.41) NNTB=26. Rescue analgesia intake was significantly higher in the control group (41 vs 18 patients of experimental group) RR=0.49 (95%CI 0.32-0.75, 𝘱<0.05) NNTB=3.

Conclusions

The use of 2g amoxicillin 1 hour before surgery was not effective in significantly reducing the risk of postoperative infections from impacted mandibular third molars extraction, when compared to placebo. Nevertheless, antibiotic prophylaxis was associated with a reduced need for rescue analgesia.

Key words:Antibiotic prophylaxis, third molar, tooth extraction, impacted tooth, dry socket, surgical wound infection, oral surgery.

Clinical characteristics and outcomes of 1,331 patients with COVID-19: HM Spanish Cohort

OBJECTIVE

Spain is one of the European countries most affected by the COVID-19 pandemic. Epidemiologic studies are warranted to improve the disease understanding, evaluate the care procedure and prepare for futures waves. The aim of the study was to describe epidemiologic characteristics associated with hospitalized patients with COVID-19.

METHODS

This real-world, observational, multicenter and retrospective study screened all consecutive patients admitted to 8 Spanish private hospitals. Inclusion criteria: hospitalized adults (age≥18 years old) with clinically and radiologically findings compatible with COVID-19 disease from March 1st to April 5th, 2020. Exclusion criteria: patients presenting negative PCR for SARS-CoV-2 during the first 7 days from hospital admission, transfer to a hospital not belonging to the HM consortium, lack of data and discharge against medical advice in emergency departments.

RESULTS

One thousand and three hundred thirty-one COVID-19 patients (medium age 66.9 years old; males n= 841, medium length of hospital stayed 8 days, non-survivors n=233) were analyzed. One hundred and fifteen were admitted to intensive care unit (medium length of stay 16 days, invasive mechanical ventilation n= 95, septic shock n= 37 and renal replacement therapy n= 17). Age, male gender, leukocytes, platelets, oxygen saturation, chronic therapy with steroids and treatment with hydroxychloroquine/azithromycin were independent factors associated with mortality. The proportion of patients that survive and received tocilizumab and steroids were lesser and higher respectively than those that die, but their association was not significant.

CONCLUSIONS

Overall crude mortality rate was 17.5%, rising up to 36.5% in the subgroup of patients that were admitted to the intensive care unit. Seven factors impact in hospital mortality. No immunomodulatory intervention were associated with in-hospital mortality.

Thyroid and Parathyroid Neoplasms with Lipomatous Stroma: Report of Three Cases and Review of the Literature

Introduction/Objective

Tumors with mixed adipose tissue and epithelial components are rare in thyroid and parathyroid glands. Most of them are benign and referred to as adenolipoma (or lipoadenoma). A handful of malignant tumors of thyroid follicular cell origin have been reported with abundant adipose tissue known as thyroid carcinoma with lipomatous stroma (TCLS). Adenolipomas of thyroid or TCLS are usually manifested as large thyroid nodules and evaluated by fine needle aspiration biopsy (FNAB) which frequently yield low-cellularity samples due to abundant adipose tissue. On FNAB, the adipose tissue usually interpreted as contamination of subcutaneous or perithyroid origin. Similarly, adenolipomas of the parathyroid are not frequently identified because of presence of adipose tissue which is a feature associated with normal parathyroid glands. Therefore, these tumors are not often correctly diagnosed preoperatively. For that reason, pathologist should report additional cases about this rare entity to increase our understanding and to decrease preoperative diagnostic error.

Methods

We report three cases of thyroid and parathyroid tumors with abundant adipose tissue with sonographic, cytologic and histologic features along with literature review.

Results

Among the reported cases in the literature and our cases; 10 out of 17 cases of thyroid carcinoma with lipomatous stroma are papillary thyroid carcinomas (58.8%), 3 out of 17 cases are papillary microcarcinomas (17.6%), 2 out of 17 cases are noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) (11.7%), and 2 out of 17 cases are minimally invasive follicular carcinomas (11.7%). No cases of poorly differentiated or anaplastic thyroid carcinomas have been reported.

Conclusion

Lipomatous stroma in thyroid carcinoma appears to be associated with differentiated carcinomas since no reported cases of poorly differentiated or anaplastic thyroid carcinomas are present to our knowledge. Although the presence of fatty tissue does not appear to alter the prognosis of these lesions, the question of the histogenesis of the adipose component is intriguing. Awareness of this unusual feature and increased utilization of multimodal approaches in the evaluation of this entity may increase preoperative detection and the understanding of the histogenesis and its possible significance.

Poorly Differentiated Chordoma with Rhabdoid Features

Casestudy: Chordoma is an uncommon primary malignant tumor of the bone showing notochordal differentiation. The current World Health Organization classifies chordoma into three subtypes: conventional, chondroid, and dedifferentiated.

Poorly differentiated chordoma (PDC) is a newly described variant of chordoma, with its own distinct features in terms of age distribution (common in pediatric and young adults), histopathology (lack of physaliphorous cells and chondromyxoid matrix), immunohistochemical and molecular characteristics (loss of SMARCB1/INI1 expression) and clinical outcome (poor prognosis with rapid onset of local recurrence and metastasis).

Herein, we report the case of a 43 year old man with history of fall and injury of tailbone 2 years prior, who presented with pain and swelling at the sacrcoccygeal region and intermittent numbness in the legs. MRI of the pelvis showed a 9.8 cm lobulated mass centered on the sacrum with osseous destruction of S5 through coccyx, with intralesional hemorrhage, and mild heterogeneous enhancement. Biopsy of the sacrococcygeal mass demonstrated a malignant neoplasm composed of lobules of epithelioid cells with abundant eosinophilic cytoplasm showing focal vacuolization, and mild to moderate nuclear pleomorphism with an average 3 mitoses per high power field (400x). Immunohistochemically, the neoplastic cells were positive for pancytokeratin, CAM 5.2, vimentin and brachyury. They had loss of SMARCB1 (INI1) and were negative for S100, CK7, CK20, desmin and actin. The location, imaging studies, morphologic features and immunohistochemical profile were consistent with poorly differentiated chordoma with rhabdoid features. With its specific clinical, morphologic, immunophenotypical, and molecular features, PDC may be recognized as a chordoma subtype in a future WHO classification. According to current knowledge, the diagnosis of PDC should be restricted to cases with brachyury expression (specific for notochord tumors) and INI1 protein loss, especially in tumors of pediatric and young patients, regardless of cellular characteristics.

Development of a predictive model for hospital mortality and re-admission in a cohort of infected patients that require hospitalization

Introducción

Los objetivos del estudio fueron: identificar variables asociadas a mortalidad intrahospitalaria y reingreso hospitalario a 3 meses; identificar el impacto de la demora en el inicio de la antibioticoterapia en la mortalidad y reportar la tasa de antibioticoterapia inapropiada.

Material y métodos

Estudio observacional de cohortes retrospectivo realizado en el Hospital Universitario HM Sanchinarro en Madrid. Los criterios de inclusión fueron: edad> 18 años de edad, hospitalización desde urgencias durante el periodo 1 de septiembre 2012 al 31 de marzo del 2013 con diagnóstico de infección bacteriana. Los criterios de exclusión fueron: sospecha de infección viral y cultivos bacteriológicos negativos, expectativa de vida inferior a 6 meses, falta de información clínica, asistencia exclusivamente por el servicio de urgencias traumatológicas. Se realizaron dos modelos logísticos (mortalidad y reingreso hospitalarios).

Resultados

Se incluyeron 517 pacientes. Variables asociadas a mortalidad (30 fallecidos): frecuencia respiratoria (OR 1,12; IC95% 1,02; 1,22), saturación de oxígeno (OR 0,92; IC95% 0,87; 0,98), creatinina (OR 2,33; IC95% 1,62; 3,36), EPOC (OR 3,02; IC95% 1,06; 8,21), cáncer OR 3,34; IC95% 1,07; 9,98) y quimioterapia en los últimos 3 meses (OR 4,83; IC95% 1,54; 16,41). Variables asociadas a reingreso hospitalario (28 fallecidos): hepatopatía, GPT, antecedente de ictus e hipertensión arterial. Ambos modelos se destacan por su elevada especificidad y capacidad discriminativa pero baja sensibilidad. La demora en el inicio de la antibioticoterapia no influyo en la mortalidad ni reingreso. En 56 pacientes se identificó el microorganismo causal y el tratamiento antibiótico fue inapropiado en 11.

Conclusiones

Se registro un 5,8% de mortalidad hospitalaria y un 5,7% de reingresos. Las variables asociadas a la mortalidad intrahospitalaria difieren de las asociadas al reingreso. La demora en el inicio de la antibioticoterapia no se asoció a un efecto deletéreo. La antibioticoterapia inadecuada fue de casi el 20%.

Infectious postoperative complications in oral surgery. An observational study

Background

The main objective of this investigation was to determine the incidence of infectious postoperative complications in oral surgery.

Material and Methods

A observational and descriptive study was developed, with the use of prospective registry of the patients admitted for oral surgery at the San Borja Arriarán Hospital Complex during twelve months observation period (April 2017 to March 2018).

Results

The sample consisted of 532 patients undergoing surgical procedures of oral surgery and 19 cases of infectious postoperative complications. The incidence of complications reached 3,57% and it was observed predominantly in exodontic type interventions. The most commonly observed complication was dry socket, reaching 2,5% of third molar surgeries and 3,7% of extractions of other teeth. Other postoperative complication were 7 cases of facial spaces abscesses, also observed predominantly in exodontic type interventions.

Conclusions

The results were similar to those reported in the literature both in their frequency and in the type of complication.

Key words:Oral surgery, incidence, postoperative complications, dry socket, third molar.

Antiplatelet therapy in patients undergoing oral surgery: A systematic review and meta-analysis

Background

The number of patients under antiplatelet therapy (APT) continues to raise as current recommendations foster this practice. Although some recommendations to manage this treatment during oral surgery procedures exist, these have methodological shortcomings that preclude them from being conclusive.

Material and Methods

A systematic review and meta-analysis of the best current evidence was carried out; The Cochrane Library, EMBASE and MEDLINE databases were searched for Randomized Controlled Trials (RCT) concerning patients undergoing oral surgery with APT, other relevant sources were searched manually.

Results

5 RCTs met the Inclusion criteria. No clear tendency was observed (RR= 0.97 CI 95%: 0,41–2,34; p=0,09; I2= 51%), moreover, they weren’t clinically significant.

Conclusions

According to these findings and as bleeding is a manageable complication it seems unreasonable to undermine the APT, putting the patient in danger of a thrombotic event and its high inherent morbidity, which isn’t comparable in severity and manageability to the former.”

Key words:Antiplatelet therapy, aspirin, oral surgery, platelet aggregation inhibitors, oral surgical procedures, systematic reviews.

Measuring laboratory-based influenza surveillance capacity: development of the 'International Influenza Laboratory Capacity Review' Tool

OBJECTIVES

The 2005 International Health Regulations (IHR 2005) emphasized the importance of laboratory capacity to detect emerging diseases including novel influenza viruses. To support IHR 2005 requirements and the need to enhance influenza laboratory surveillance capacity, the Association of Public Health Laboratories (APHL) and the Centers for Disease Control and Prevention (CDC) Influenza Division developed the International Influenza Laboratory Capacity Review (Tool).

STUDY DESIGN

Data from 37 assessments were reviewed and analyzed to verify that the quantitative analysis results accurately depicted a laboratory's capacity and capabilities.

METHODS

Subject matter experts in influenza and laboratory practice used an iterative approach to develop the Tool incorporating feedback and lessons learnt through piloting and implementation. To systematically analyze assessment data, a quantitative framework for analysis was added to the Tool.

RESULTS

The review indicated that changes in scores consistently reflected enhanced or decreased capacity. The review process also validated the utility of adding a quantitative analysis component to the assessments and the benefit of establishing a baseline from which to compare future assessments in a standardized way.

CONCLUSIONS

Use of the Tool has provided APHL, CDC and each assessed laboratory with a standardized analysis of the laboratory's capacity. The information generated is used to improve laboratory systems for laboratory testing and enhance influenza surveillance globally. We describe the development of the Tool and lessons learnt.

Sphingomyelin derivatives increase the frequency of microvesicle and granule fusion in chromaffin cells

Sphingomyelin derivatives like sphingosine have been shown to enhance secretion in a variety of systems, including neuroendocrine and neuronal cells. By studying the mechanisms underlying this effect, we demonstrate here that sphingomyelin rafts co-localize strongly with synaptosomal-associated protein of 25Kda (SNAP-25) clusters in cultured bovine chromaffin cells and that they appear to be linked in a dynamic manner. In functional terms, when cultured rat chromaffin cells are treated with sphingomyelinase (SMase), producing sphingomyelin derivatives, the secretion elicited by repetitive depolarizations is enhanced. This increase was independent of cell size and it was significant 15min after initiating stimulation. Interestingly, by evaluating the membrane capacitance we found that the events in control untreated cells corresponded to two populations of microvesicles and granules, and the fusion of both these populations is clearly enhanced after treatment with SMase. Furthermore, SMase does not increase the size of chromaffin granules. Together, these results strongly suggest that SNARE-mediated exocytosis is enhanced by the generation of SMase derivatives, reflecting an increase in the frequency of fusion of both microvesicles and chromaffin granules rather than an increase in the size of these vesicles.

MEK inhibition affects STAT3 signaling and invasion in human melanoma cell lines

Elevated activity of the mitogen-activated protein kinase (MAPK) signaling cascade is found in the majority of human melanomas and is known to regulate proliferation, survival and invasion. Current targeted therapies focus on decreasing the activity of this pathway; however, we do not fully understand how these therapies impact tumor biology, especially given that melanoma is a heterogeneous disease. Using a three-dimensional (3D), collagen-embedded spheroid melanoma model, we observed that MEK and BRAF inhibitors can increase the invasive potential of ∼20% of human melanoma cell lines. The invasive cell lines displayed increased receptor tyrosine kinase (RTK) activity and activation of the Src/FAK/signal transducers and activators of transcription-3 (STAT3) signaling axis, also associated with increased cell-to-cell adhesion and cadherin engagement following MEK inhibition. Targeting various RTKs, Src, FAK and STAT3 with small molecule inhibitors in combination with a MEK inhibitor prevented the invasive phenotype, but only STAT3 inhibition caused cell death in the 3D context. We further show that STAT3 signaling is induced in BRAF-inhibitor-resistant cells. Our findings suggest that MEK and BRAF inhibitors can induce STAT3 signaling, causing potential adverse effects such as increased invasion. We also provide the rationale for the combined targeting of the MAPK pathway along with inhibitors of RTKs, SRC or STAT3 to counteract STAT3-mediated resistance phenotypes.

National Ignition Facility system alignment

The National Ignition Facility (NIF) is the world's largest optical instrument, comprising 192 37 cm square beams, each generating up to 9.6 kJ of 351 nm laser light in a 20 ns beam precisely tailored in time and spectrum. The Facility houses a massive (10 m diameter) target chamber within which the beams converge onto an ∼1 cm size target for the purpose of creating the conditions needed for deuterium/tritium nuclear fusion in a laboratory setting. A formidable challenge was building NIF to the precise requirements for beam propagation, commissioning the beam lines, and engineering systems to reliably and safely align 192 beams within the confines of a multihour shot cycle. Designing the facility to minimize drift and vibration, placing the optical components in their design locations, commissioning beam alignment, and performing precise system alignment are the key alignment accomplishments over the decade of work described herein. The design and positioning phases placed more than 3000 large (2.5 m×2 m×1 m) line-replaceable optics assemblies to within ±1 mm of design requirement. The commissioning and alignment phases validated clear apertures (no clipping) for all beam lines, and demonstrated automated laser alignment within 10 min and alignment to target chamber center within 44 min. Pointing validation system shots to flat gold-plated x-ray emitting targets showed NIF met its design requirement of ±50 μm rms beam pointing to target chamber. Finally, this paper describes the major alignment challenges faced by the NIF Project from inception to present, and how these challenges were met and solved by the NIF design and commissioning teams.

Notes from the field: outbreak of 2009 pandemic influenza A (H1N1) virus at a large public university in Delaware, April-May 2009

BACKGROUND

In late April 2009, the first documented 2009 pandemic influenza A (pH1N1) virus infection outbreak in a university setting occurred in Delaware, with large numbers of students presenting with respiratory illness. At the time of this investigation, little was known about the severity of illness, effectiveness of the vaccine, or transmission factors of pH1N1 virus infection. We characterized illness, determined the impact of this outbreak, and examined factors associated with transmission.

METHODS

Health clinic records were reviewed. An online survey was administered to all students, staff, and faculty to assess influenza-like illness (ILI), defined as documented or subjective fever with cough or sore throat.

RESULTS

From 26 April-2 May 2009, the health clinic experienced a sharp increase in visits for respiratory illness, with 1080 such visits among a total of 1430 student visits, and then a return to baseline visit levels within 2 weeks. More than 500 courses of oseltamivir were distributed, and 24 cases of influenza A (pH1N1) virus infection were confirmed. Of 29,000 university students and faculty/staff, 7450 (30%) responded to the survey. ILI was reported by 604 (10%) of the students and 73 (5%) of the faculty/staff. Travel to Mexico (relative risk [RR], 2.9; 95% confidence interval [CI], 1.8-4.7) and participation in "Greek Week" activities (RR, 2.2; 95% CI, 1.8-2.8) were associated with ILI. Recipients of the 2008-2009 seasonal influenza vaccine had the same risk of ILI as nonrecipients (RR, 1.0). Four (3%) of the students with ILI were hospitalized; there were no deaths.

CONCLUSIONS

pH1N1 spread rapidly through the University of Delaware community with a surge in illness over a 2-week period. Although initial cases appear to be associated with travel to Mexico, a rapid increase in cases was likely facilitated by increased student interactions during Greek Week. No protective effect from receiving seasonal influenza vaccine was identified. Although severe illness was rare, the outbreak caused a substantial burden and challenge to the university health care system. Preparedness efforts in universities and similar settings should include enhancing health care surge capacity.

Vesicle movements are governed by the size and dynamics of F-actin cytoskeletal structures in bovine chromaffin cells

Dense vesicles can be observed in live bovine chromaffin cells using fluorescent reflection confocal microscopy. These vesicles display a similar distribution, cytoplasmic density and average size as the chromaffin granules visualized by electron microscopy. In addition, the acidic vesicles labeled with Lysotracker Red comprised a subpopulation of the vesicles that are visualized by reflection fluorescence. A combination of fluorescence reflection and transmitted light images permitted the movements of vesicles in relation to the cortical cytoskeleton to be studied. The movement of vesicles located on the outside of this structure was restricted, with an apparent diffusion coefficient of 1.0+/-0.4 x 10(-4) microm(2)/s. In contrast, vesicles located in the interior moved much more freely and escaped from the visual confocal plane. Lysotracker labeling was more appropriate to study the movement of the faster moving vesicles, whose diffusion coefficient was five times higher. Using this type of labeling we confirmed the restriction on cortical movement and showed a clear relationship between vesicle mobility and the kinetics of cytoskeletal movement on both sides of the cortical cytoskeleton. This relationship was further emphasized by studying cytoskeletal organization and kinetics. Indeed, an estimate of the size of the cytoskeletal polygonal cages present in the cortical region and in the cell interior agreed well with the calculation of the theoretical radius of the cages imprisoning vesicle movement. Therefore, these data suggest that the structure and kinetics of the cytoskeleton governs vesicle movements in different regions of chromaffin cells.

Perforin polymorphism A91V and susceptibility to B-precursor childhood acute lymphoblastic leukemia: a report from the Children's Oncology Group

Perforin plays a key role in the cytotoxicity of natural killer and cytotoxic T cells. Genetic mutations in the perforin gene (PRF1) give rise to approximately 30% cases of familial hemophagocytic lymphohistiocytosis. A frequent polymorphism, A91V (C to T transition at position 272), may impair processing of perforin protein to the active form, and has been suggested to increase susceptibility to childhood acute lymphoblastic leukemia (ALL). To investigate the role of A91V in ALL, we genotyped 2272 children with de novo ALL registered on the Pediatric Oncology Group ALL Classification study P9900 and 655 normal controls. Allele frequencies in the controls showed a very low frequency of the variant allele in blacks, 0.7% compared to 4% in white controls. In light of this, analysis was restricted to a comparison of white cases and controls only. Overall genotype frequencies were similar in white ALL cases and normal white controls (P=0.58), indicating that in contrast to the previous report, A91V polymorphism is not associated with increased risk of childhood ALL. PRF1 A91V frequency was significantly increased in children with BCR-ABL positive ALL (24 vs 8.5%; P=0.0048); however, this observation includes a relatively small number of cases and needs further exploration.

Preliminary results of a randomized phase II study comparing two schedules of temozolomide in combination with sorafenib in patients with advanced melanoma

8009

Background: Sorafenib (SO) is an oral Raf kinase/VEGFR-2 inhibitor that has anti-melanoma activity when given with carboplatin/paclitaxel. The primary objective of this study is to estimate the duration of progression-free survival (PFS) for patients with metastatic melanoma (MM) taking SO + temozolomide (TEM). Secondary objectives are to determine the optimal dosing of TEM when given with SO, response, and toxicity rates. Correlative studies include BRAF genotyping and assessment of intratumoral Raf inhibition. Methods: Patients with MM and ECOG PS<2 are eligible. Prior therapy is allowed. Accrual is designed for 167 patients in one stage. All patients receive SO 400 mg po bid continuously. After one week of SO alone, patients without brain metastasis and no prior TEM are randomized to receive either extended daily dosing (EDD): TEM 75 mg/m2 po qd for 6 /8 weeks (Arm A), or standard dosing (STD): TEM 150 mg/m2 po qd for days1–5/28 (Arm B). Patients with prior TEM use are treated with EDD (Arm C) and patients with brain metastasis without prior TEM are treated with STD (Arm D). Responses are assessed using RECIST criteria. Results: 65 patients were evaluated for toxicity. Of these, 58 received SO + TEM and were evaluable for response (Table). SO + TEM resulted in a 24% overall response rate (ORR) [95% CI 11–41%] in patients without brain metastasis or prior TEM and 20% ORR [95% CI 3–56%] in patients with brain metastasis and no prior TEM. Observed grade 3 toxicities attributable to study medication were: hand-foot syndrome (12%), rash (8%), nausea (5%), anorexia (8%), and hypertension (3%). Nausea and anorexia were more prevalent with STD. Tumor blocks and 8 paired biopsy samples have been collected for correlative studies. Conclusions: Initial phase II results demonstrate encouraging antitumor activity and safety profile for SO + TEM in MM. Updated PFS data, response and toxicity rates, and correlative results will be presented.

[Table: see text]

[Table: see text]

Non-linear effects in the determination of paleotemperature Uk′37 alkenone ratios by chemical ionization mass spectrometry

The performance of gas chromatography coupled to mass spectrometry in the positive chemical ionization mode using ammonia as reagent gas (GC-PCI-MS) in the analysis of C37 alkenones for paleotemperature estimation has been re-evaluated. In some conditions, the discrepancies observed in the measurement of the U37(k') index with this technique as compared with GC equipped with flame ionization detection (GC-FID) cannot be explained by differences in sensitivity between the tri- and diunsaturated alkenones. Thus, at low (currently <0.3) or high (currently >0.4) U37(k') values the GC-PCI-MS determinations may be observed to be lower or higher, respectively, than those measured with GC-FID. As shown by analysis of a series of synthetic C37 alkenone standards these discrepant results can be explained by non linear effects in the GC-PCI-MS response factors. Second-order polynomial functions provide equations that describe better the signal to amount of analyte ratios. Users of GC-PCI-MS should calibrate their instruments with standards of known C37 alkenone composition in order to minimize non-linear effects.

Tumor necrosis factor-related apoptosis inducing ligand (TRAIL) up-regulates death receptor 5 (DR5) mediated by NFkappaB activation in epithelial derived cell lines

Tumor necrosis factor-related apoptosis inducing ligand (TRAIL/APO-2L) activates nuclear factor kappaB (NFkappaB). This activation is regulated by the recruitment of an adaptor protein Fas associating death domain (FADD) to TRAIL death receptors, death receptor 4 (DR4, TRAIL-R1) and death receptor 5 (DR5 TRAIL-R2). This leads to recruitment of caspase 8 and receptor interacting protein (RIP) to the receptor complex. Upon recruitment of caspase 8 and RIP, NFkappaB inducing kinase (NIK) becomes activated causing NFkappaB activation. The role of TRAIL induced NFkappaB activation in epithelial cells is unknown. Herein we demonstrate that TRAIL increases expression of DR5 in human embryonic kidney (HEK) 293, MCF-7 and MDA MB 231 epithelial cell lines while DR4 expression remains unchanged. Blockage of NFkappaB activation either by expression of dominant negative IkappaB or treatment with proteasome inhibitor lactacystin eliminates TRAIL induced DR5 expression. Expression of FADD dominant negative in HEK 293 cells that prevents the recruitment of caspase 8 and RIP to TRAIL death receptors also eliminates this increase. By over expression of the p65 subunit of NFkappaB that increases NFkappaB transcriptional activity, DR5 expression was increased compared to vector alone expressing cells. By blocking TRAIL induced NFkappaB activation, the sensitivity of cells to undergo TRAIL induced apoptosis was significantly decreased. Conversely, the amount of TRAIL induced apoptosis was increased in HEK 293 cells over expressing p65 subunit of NFkappaB. Finally blockage of NFkappaB activation eliminates the synergistic apoptotic response of TRAIL and etoposide. Thus, TRAIL mediated NFkappaB activation increases DR5 expression thereby amplifying the apoptotic response of TRAIL in epithelial derived cells.

Timing of cyclin D1 expression within G1 phase is controlled by Rho

The expression of cyclin D1 in mid-G1 phase is associated with sustained ERK activity, and we show here that Rho is required for the sustained ERK signal. However, we also report that Rho inhibits an alternative Rac/Cdc42-dependent pathway, which results in a strikingly early G1-phase expression of cyclin D1. Thus, cyclin D1 is induced in mid-G1 phase because a Rho switch couples its expression to sustained ERK activity rather than Rac and Cdc42. Our results show that Rho is crucial for maintaining the correct timing of cyclin D1 expression in G1 phase and describe a new role for cytoskeletal integrity in the regulation of cell cycle progression.

Monitoring the expression and purification of recombinant proteins by MALDI-TOF mass spectrometry

1Samples coming from biologic sources usually contain several contaminants that interfere seriously with Mass Spectrometry (MS) measurements. In this paper we report the application of MALDI-TOF MS to monitor recombinant protein expression and purification. The technique is based on the use of a C18 resin to clean and concentrate proteins in batch. The utility of this method is demonstrated for samples coming from different bacterial cultures expressing secreted and intracellular proteins ranging from 4 to 53 kDa. MALDI-TOF MS of peptide and proteins can be accomplished directly from complex bacterial cultures or from any purification step in a few minutes using the conventional stainless steel sample targets, allowing for a nearly instantaneous monitoring of the nature and integrity of recombinant expression products.