ABSTRACT
BACKGROUND: Minimal residual disease (MRD) monitoring has been used to identify early molecular relapse and predict clinical relapse in mantle cell lymphoma (MCL). Few published data exist in MCL on the performance of next-generation sequencing-based assay of immunoglobulin gene rearrangements for MRD assessment. PATIENTS AND METHODS: In a prospective clinical trial (NCT01484093) with intensive induction chemotherapy and autologous stem-cell transplantation, posttreatment peripheral blood samples were collected from 16 MCL patients and analyzed with an earlier version of the Adaptive Biotechnologies MRD assay. RESULTS: Of the 7 patients whose disease remained in remission, the MRD test remained negative in 5 (71%). Of the 9 patients who experienced relapse, the MRD test was positive at least 3 months before relapse in 6 patients (67%) and positive at the time of relapse in 1 patient (11%). All patients with at least 2 positive MRD tests experienced relapse. CONCLUSION: The next-generation sequencing-based MRD assay identified early molecular relapse, and we observed more sensitivity in the cellular (circulating leukocytes) versus acellular (plasma cell-free DNA) compartment. This observation may be due to availability of tumor target or a limitation of the assay.
Subject(s)
DNA, Neoplasm/blood , Lymphoma, Mantle-Cell/blood , Lymphoma, Mantle-Cell/diagnosis , Neoplasm Recurrence, Local/blood , Neoplasm Recurrence, Local/diagnosis , Aged , Chemoradiotherapy , Female , Gene Rearrangement , High-Throughput Nucleotide Sequencing , Humans , Immunoglobulins/genetics , Immunotherapy , Induction Chemotherapy , Lymphoma, Mantle-Cell/genetics , Lymphoma, Mantle-Cell/therapy , Male , Middle Aged , Neoplasm Recurrence, Local/genetics , Neoplasm, Residual , Neoplastic Cells, Circulating , Prospective Studies , Remission Induction , Stem Cell Transplantation , Transplantation, AutologousABSTRACT
AIM: This survey assessed the attitude of paediatric dental EAPD members toward using "knee-to-knee" positioning for dental examinations and minor procedures in infants and toddlers. METHODS: An anonymous electronic online questionnaire was distributed among EAPD members. The survey consisted of 12 questions and assessed demographic characteristics, professional experience and attitudes toward the use of the "knee-to-knee" position. RESULTS: Of the 162 respondents, 148 (91%) reported using "knee-to-knee" positioning for dental examination. In addition, 97 (63%) reported performing other procedures in the "knee-to-knee" position. Fluoride application and oral hygiene instructions were the most common procedures performed in the "knee-to-knee" position. CONCLUSIONS: Most of the paediatric dentists who responded to this survey reported performing dental examinations in toddlers up to 2 years old using the "knee-to-knee" position. Majority of respondents also used this position to instruct parents regarding oral hygiene and to apply fluoride varnish.
Subject(s)
Attitude of Health Personnel , Dentists , Child , Child, Preschool , Dental Care , Humans , Infant , Oral Hygiene , Surveys and QuestionnairesABSTRACT
PURPOSE: The objective of this study was to assess the knowledge of dentists, dental hygienists and dental students regarding the Israeli Ministry of Health guidelines for using fluoridated toothpaste. MATERIALS AND METHODS: An anonymous questionnaire was distributed to dentists, dental hygienists, and dental students in their final years at the Hebrew University-Hadassah School of Dental Medicine. Participants were queried regarding their knowledge of Ministry of Health fluoride concentration guidelines in toothpaste by the following age categories: under 2 years, 2-6 years, and above 6 years. RESULTS: Thirty-two paediatric dentists (specialists and residents), 63 general dentists, 68 dental hygienists, and 69 students responded to the survey. Analysis of survey respondent's knowledge of Ministry of Health fluoride toothpaste guidelines by age group found that 81%, 75% and 88% of participants selected a fluoride concentration within the recommended range for those under 2 years, 2-6 years and greater than 6 years, respectively. Only 58% of respondents were aware of the recommended fluoride concentration for all three age groups. Among respondents who answered all three questions, there was a significant association between correctly answering the fluoride questions and respondent's profession (P = 0.026), with a larger percentage of paediatric dentist (76%) and dental students (66%) correctly answering all three questions. CONCLUSIONS: Israeli dental practitioners should be educated about the Israeli Ministry of Health fluoride concentrations in toothpaste guidelines. The guidelines should be emphasised at annual meetings and in continuing education courses.
Subject(s)
Fluorides , Toothpastes , Attitude of Health Personnel , Child , Dental Hygienists , Dentists , Humans , Professional Role , Students, Dental , Surveys and QuestionnairesABSTRACT
BACKGROUND: Localized early-stage extra-nodal marginal zone lymphoma (MZL) presents with heterogeneous organ involvement and is treated with various modalities, including resection, radiotherapy, and systemic therapy. We report the long-term outcome of a large cohort of extra-nodal MZL and assess the impact of patient and disease characteristics, organ site, and treatment strategy on disease control and survival. PATIENTS AND METHODS: We identified 487 consecutive patients with stage IE or IIE MZL referred between 1992 and 2012 to Memorial Sloan Kettering Cancer Center. Pathology was reviewed by hematopathologists at our institution. Patient and disease factors as well as treatment types were analyzed for association with relapse-free survival, overall survival, and cumulative incidence of relapse. RESULTS: Median follow-up after treatment was 4.7 years. Five-year relapse-free survival and overall survival were 60% and 89%, respectively. Cumulative incidence of disease-specific death at 5 years was 1.3%. Radiotherapy alone was the initial treatment in 50% of patients, followed by surgical resection (30%), observation (8%), immunotherapy (4%), and chemotherapy (2%). Initial treatment type, primary disease site, and number of involved sites were significant factors in multivariable analysis of relapse (all P < 0.05). When compared with stomach, MZL originating in other disease sites (HR > 2.0, P ≤ 0.001), except for thyroid, had higher risk of relapse. Strategies such as antibiotics or topical therapies were associated with higher risk of relapse when compared with radiation therapy (P < 0.001). Crude rate of transformation to pathologically confirmed large-cell lymphoma was 2% (11 patients). CONCLUSION: Overall and cause-specific survival are high in early-stage extra-nodal MZL. Curative-intent treatment led to fewer relapses and reduced the need for salvage. Stomach cases had lower risk of relapse than other anatomic primary sites. This study supports the use of local therapies to treat stage IE and IIE MZL.
Subject(s)
Lymphoma, B-Cell, Marginal Zone/epidemiology , Lymphoma, B-Cell, Marginal Zone/therapy , Neoplasm Recurrence, Local/epidemiology , Neoplasm Recurrence, Local/therapy , Adolescent , Adult , Aged , Aged, 80 and over , Child , Combined Modality Therapy , Disease-Free Survival , Female , Humans , Immunotherapy , Lymphoma, B-Cell, Marginal Zone/pathology , Lymphoma, B-Cell, Marginal Zone/surgery , Male , Middle Aged , Neoplasm Recurrence, Local/pathology , Neoplasm Staging , Prognosis , Salvage Therapy , Treatment Outcome , Young AdultSubject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , HTLV-I Infections/complications , Human T-lymphotropic virus 1 , Leukemia-Lymphoma, Adult T-Cell/drug therapy , Leukemia-Lymphoma, Adult T-Cell/etiology , Bortezomib/administration & dosage , Cyclophosphamide/therapeutic use , Doxorubicin/therapeutic use , Etoposide/therapeutic use , HTLV-I Infections/virology , Human T-lymphotropic virus 1/genetics , Humans , Leukemia-Lymphoma, Adult T-Cell/mortality , Prednisone/therapeutic use , Raltegravir Potassium/administration & dosage , Treatment Outcome , Vincristine/therapeutic useABSTRACT
BACKGROUND: We undertook the present analysis to examine the shifting influence of prognostic factors in HIV-positive patients diagnosed with aggressive non-Hodgkin lymphoma (NHL) over the last two decades. PATIENTS AND METHODS: We carried out a pooled analysis from an existing database of patients with AIDS-related lymphoma. Individual patient data had been obtained prior from prospective phase II or III clinical trials carried out between 1990 until 2010 in North America and Europe that studied chemo(immuno)therapy in HIV-positive patients diagnosed with AIDS-related lymphomas. Studies had been identified by a systematic review. We analyzed patient-level data for 1546 patients with AIDS-related lymphomas using logistic regression and Cox proportional hazard models to identify the association of patient-, lymphoma-, and HIV-specific variables with the outcomes complete response (CR), progression-free survival, and overall survival (OS) in different eras: pre-cART (1989-1995), early cART (1996-2000), recent cART (2001-2004), and contemporary cART era (2005-2010). RESULTS: Outcomes for patients with AIDS-related diffuse large B-cell lymphoma and Burkitt lymphoma improved significantly over time, irrespective of baseline CD4 count or age-adjusted International Prognostic Index (IPI) risk category. Two-year OS was best in the contemporary era: 67% and 75% compared with 24% and 37% in the pre-cART era (P < 0.001). While the age-adjusted IPI was a significant predictor of outcome in all time periods, the influence of other factors waxed and waned. Individual HIV-related factors such as low CD4 counts (<50/mm(3)) and prior history of AIDS were no longer associated with poor outcomes in the contemporary era. CONCLUSIONS: Our results demonstrate a significant improvement of CR rate and survival for all patients with AIDS-related lymphomas. Effective HIV-directed therapies reduce the impact of HIV-related prognostic factors on outcomes and allow curative antilymphoma therapy for the majority of patients with aggressive NHL.
Subject(s)
Anti-HIV Agents/therapeutic use , Antineoplastic Agents/therapeutic use , HIV Infections/therapy , Immunotherapy/methods , Lymphoma, AIDS-Related/therapy , Lymphoma, Non-Hodgkin/therapy , Adolescent , Adult , Aged , Anti-HIV Agents/adverse effects , Antineoplastic Agents/adverse effects , Chi-Square Distribution , Clinical Trials, Phase II as Topic , Clinical Trials, Phase III as Topic , Databases, Factual , Disease Progression , Disease-Free Survival , Europe , Female , HIV Infections/diagnosis , HIV Infections/immunology , HIV Infections/mortality , Humans , Immunotherapy/adverse effects , Kaplan-Meier Estimate , Logistic Models , Lymphoma, AIDS-Related/diagnosis , Lymphoma, AIDS-Related/immunology , Lymphoma, AIDS-Related/mortality , Lymphoma, Non-Hodgkin/diagnosis , Lymphoma, Non-Hodgkin/immunology , Lymphoma, Non-Hodgkin/mortality , Male , Middle Aged , Multivariate Analysis , North America , Proportional Hazards Models , Risk Assessment , Risk Factors , Time Factors , Treatment Outcome , Young AdultABSTRACT
BACKGROUND: The World Health Organization (WHO) classification of hematologic malignancies, published in 2000, was designed to improve diagnostic accuracy by incorporating the latest in scientific understanding. The impact of the WHO classification on the frequency of diagnostic discrepancy in lymphoma is unknown. METHODS: We reviewed all second-opinion pathology of lymphoma at our National Cancer Institute-designated Comprehensive Cancer Center (NCI-CCC) from January to June 2001 and from January to June 2006. Discrepancies between submitted and second-opinion diagnoses were scored based upon an a priori grading schema. RESULTS: Major diagnostic revision was rendered in 65 of 365 cases (17.8%) in 2001 and 58 of 354 (16.4%) in 2006 (P=NS). Including cases reviewed and revised beforehand at another NCI-CCC, rates of major diagnostic revision were 21.4% and 18.6%, respectively (P=NS). Discrepancy rates varied by diagnosis, from Hodgkin lymphoma (10%) to Burkitt's lymphoma (75%). No association was seen for age, gender, race/ethnicity, biopsy type, or nature of referring center. CONCLUSIONS: Clinically meaningful diagnostic revision occurs frequently with expert pathology review for a diagnosis of lymphoma. Despite the WHO classification, rates of diagnostic revision at our institution in 2001 and 2006 did not differ significantly. Given the potential harm from misdiagnosis, expert hematopathology review should be considered the standard of care.
Subject(s)
Lymphoma/classification , Lymphoma/pathology , Pathology, Clinical/standards , Referral and Consultation/standards , Female , Humans , Male , Middle Aged , World Health OrganizationABSTRACT
BACKGROUND: Percutaneous exposure incidents represent an important occupational health issue. CASE REPORT: A paediatric dentist was cut by a small round bur in a handpiece. A few hours later the elbow became swollen and painful. Since the bur had been contaminated with saliva and oral flora, the injury was treated as a human bite equivalent. An X-ray revealed the broken piece of the bur in the soft tissue of the dentist's elbow. CONCLUSION: Care should be taken to prevent and treat injuries by sharp items, during and also following dental treatment.
Subject(s)
Dental Instruments/adverse effects , Dentists , Elbow Injuries , Foreign Bodies/etiology , Occupational Diseases/etiology , Soft Tissue Injuries/etiology , Wound Infection/etiology , Accidents, Occupational , Dental Instruments/microbiology , Equipment Contamination , Female , Humans , Mouth/microbiology , Saliva/microbiologyABSTRACT
Accurate assessment of pulp status is one of the greatest diagnostic challenges in clinical practice. This may be further complicated in children and adolescent where the practitioner is faced with different situations such as: primary teeth, developing permanent dentition, traumatized teeth, patients undergoing orthodontic treatment. In addition, the dentist is frequently faced with young children who have limited ability to recall a pain history or cooperate with the test itself. A variety of pulp testing approaches exist, and there may be a confusion as to their validity in different clinical situations. Sensitivity tests include thermal testing and Electric Pulp Test. Their limitation is the possibility to get false positive or false negative results. Their primary limitation lies in the fact that they test the sensory response of the tooth, which can be temporarily lost after dental trauma. A more accurate assessment of pulp vitality would be made by determining the presence of a functioning blood supply with the use of Laser Doppler Flowmetry or Pulse Oximetry. This paper provides the clinician with a comprehensive review of current pulp testing methods and allow greater insight into the interpretation of pulp testing results, especially in young patients.
Subject(s)
Dental Pulp Test/methods , Dental Pulp/blood supply , Adolescent , Child , Dental Pulp/injuries , Dentition, Permanent , Electric Stimulation , Humans , Laser-Doppler Flowmetry , Oximetry , Pain Measurement , Tooth, DeciduousABSTRACT
BACKGROUND: The Stanford group has reported excellent results with the Stanford V regimen for patients with bulky and/or advanced Hodgkin lymphoma (HL). However, Gobbi reported markedly inferior failure-free survival (FFS) comparing Stanford V to other regimens but included major deviations from the original program. We retrospectively examined whether treatment at our institution carefully following Stanford V guidelines would confirm the original Stanford outcome data. PATIENTS AND METHODS: From June 1995 to May 2002, 126 patients with either locally extensive or advanced HL were treated with the 12-week Stanford V chemotherapy program followed by 36-Gy involved-field radiotherapy to sites initially > or =5 cm and/or to macroscopic splenic disease. Overall, 26% had stage IV disease and 20% had international prognostic score (IPS) > or =4. Overall survival (OS), disease-specific survival, progression-free survival (PFS), FFS, and freedom from second relapse (FF2R) were determined. RESULTS: The 5- and 7-year OS were 90% and 88%, respectively. The 5-year FFS was 78%. IPS > or =4 was a significant independent predictor of worse OS and PFS. The FF2R was 64% at 3 years. CONCLUSION: Stanford V with appropriate radiotherapy is a highly effective regimen for locally extensive and advanced HL.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Hodgkin Disease/therapy , Neoplasm Recurrence, Local/therapy , Adolescent , Adult , Aged , Combined Modality Therapy , Disease-Free Survival , Female , Hodgkin Disease/drug therapy , Hodgkin Disease/radiotherapy , Humans , Male , Middle Aged , Neoplasm Recurrence, Local/drug therapy , Neoplasm Recurrence, Local/radiotherapy , Neoplasm Staging , Retrospective Studies , Salvage Therapy , Survival Rate , Treatment Outcome , Young AdultABSTRACT
El Eritema Multiforme (EM) es una reacción cutánea aguda generalmente benigna y autolimitada, asociada a la infección por Virus Herpes Simplex (HSV). Se caracteriza por lesiones polimorfas y tipo diana en extremidades y mucosas. Presentamos un paciente de 22 años con pápulas, vesículas y ampollas, que evoluciona con un 90% de la superficie corporal comprometida en tres semanas. Se realizó una reacción de polimerasa en cadena para HSV, resultando positiva en una costra. La biopsia de piel y la tinción de inmunohistoquímica positiva para linfocitos T CD4, fueron compatibles con EM ampollar asociado a HSV. Destacamos la importancia de la correlación clínico patológica, apoyada por el estudio virológico, en el diagnóstico de este caso de presentación atípica. Los hallazgos de laboratorio confirmaron lo descrito en la literatura respecto de la patogenia del EM asociado a HSV.
Erythema Multiforme (EM) is a generally benign and self-limited acute cutaneous reaction, associated with Herpes Simplex Virus (HSV) infection. It is characterized by polymorphic "target" lesions in extremities and mucosal tissues. We report a 22-year old patient with papules, vesicles and blisters, which evolved to cover 90% of the body in three weeks. We performed a PCR study for HSV, which was positive in a crust. A skin biopsy and positive immunohistochemical stain for LT CD4+ were compatible with bullous EM associated with HSV. We underline the importance of pathological clinical correlation, reinforced by a virological study, in the diagnosis of this case with atypical symptoms. The laboratory findings confirmed literature descriptions with respect to the pathogenicity of EM associated with HSV.
ABSTRACT
BACKGROUND: We previously correlated non-Hodgkin's lymphoma (NHL) histology with (18)fluoro-2-deoxyglucose-positron emission tomography (FDG-PET) intensity: a standardized uptake value (SUV)>10 predicted aggressive lymphoma with >80% certainty and an SUV >13, with >90% certainty. PATIENTS AND METHODS: To evaluate SUV in transformed lymphoma, we identified all FDG-PET scans for NHL at Memorial Sloan-Kettering Cancer 1999-2007 with (i) biopsy-proven transformation, (ii) no therapy 60 days before PET scan and (iii) FDG-PET scans no more than 60 days before or 90 days after transformation. RESULTS: In 5 of 40 patients, the biopsy site was excised before PET; in two, only marrow was biopsied. In the remaining 33 patients, the SUV of the biopsy site ranged from 3 to 38, mean 14, median 12. Eighteen of 33 biopsies (55%) had an SUV>10 and 16 (48%)>13. The highest SUV in a transformed lymphoma PET scan (SUV(study-max)) ranged from 3.2 to 40, mean 15, median 12. Twenty-five of 40 patients (63%) presented with an SUV(study-max)>10 and 20 (50%)>13. CONCLUSIONS: Like de novo aggressive lymphomas, the majority of transformations have a high SUV(study-max) for a given pretreatment staging study, although many do not have very high values. Transformation should be suspected in indolent lymphoma with high SUVs on FDG-PET. Biopsies should be directed to the site of greatest FDG avidity.
Subject(s)
Lymphoma, Large B-Cell, Diffuse/diagnostic imaging , Positron-Emission Tomography , Biopsy , Cohort Studies , Humans , Lymphoma, Large B-Cell, Diffuse/pathologyABSTRACT
Ultralow density polymers, metals, and ceramic nanofoams are valued for their high strength-to-weight ratio, high surface area, and insulating properties ascribed to their structural geometry. We obtain the labrynthine internal structure of a tantalum oxide nanofoam by x-ray diffractive imaging. Finite-element analysis from the structure reveals mechanical properties consistent with bulk samples and with a diffusion-limited cluster aggregation model, while excess mass on the nodes discounts the dangling fragments hypothesis of percolation theory.
Subject(s)
Ceramics/chemistry , Nanostructures/chemistry , Oxides/chemistry , Tantalum/chemistry , X-Ray Diffraction/methods , Scattering, Small Angle , X-Ray Diffraction/instrumentationABSTRACT
BACKGROUND: Eradication of Helicobacter pylori in gastric mucosa-associated lymphoid tumor can result in lymphoma remission. We prospectively identified/treated infections in nonbulky, advanced stage indolent lymphoma (follicular; nonfollicular lymphoma) eligible for observation. MATERIALS AND METHODS: Stool H. pylori, hepatitis C and Borrelia serologies, Borrelia and Chlamydia fixed tissue PCR, Chlamydia peripheral blood mononuclear cell PCR and hydrogen breath test for small bowel bacterial overgrowth (SBBO) were obtained. RESULTS: Fifty-six patients were enrolled. Positive infections: H. pylori (13); hepatitis C (3); SBBO (11). Negative: Borrelia (13); Chlamydophila psittaci (12, except one PCR). Lymphoma responses to antimicrobial therapy: H. pylori [one complete response (CR), 24+ months; one transient near CR]; hepatitis C [two CRs, 18+ and 30+ months; one partial response (PR) but hepatitis C virus persistent]; SBBO (one PR, 30+ months). Patients with associated infections, but without lymphoma CR, have required lymphoma treatment sooner than those without initial infections (treatment-free survival at 23.4 months median follow-up, 40.5% versus 74.7%, P = 0.01), indicating a different biology. CONCLUSION: Infections are common in advanced stage indolent lymphoma (37.5% in our series). Anecdotal lymphoma responses have been seen and three have been durable CRs (18 to 30+ months) with infection eradication alone. The identification and treatment of associated infections may be a first step towards developing a lymphoma prevention strategy.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Helicobacter Infections/complications , Helicobacter Infections/drug therapy , Lymphoma, B-Cell, Marginal Zone/drug therapy , Lymphoma, B-Cell, Marginal Zone/prevention & control , Stomach Neoplasms/prevention & control , Adult , Aged , Analysis of Variance , Female , Follow-Up Studies , Gastric Mucosa/drug effects , Gastric Mucosa/pathology , Helicobacter Infections/pathology , Helicobacter pylori/drug effects , Helicobacter pylori/isolation & purification , Humans , Immunohistochemistry , Lymphoma, B-Cell, Marginal Zone/microbiology , Lymphoma, B-Cell, Marginal Zone/mortality , Male , Middle Aged , Neoplasm Staging , Prospective Studies , Risk Assessment , Statistics, Nonparametric , Stomach Neoplasms/mortality , Stomach Neoplasms/pathology , Survival Analysis , Treatment OutcomeABSTRACT
BACKGROUND: Plasmablastic lymphoma (PBL) has been described as a rapidly progressive and almost invariably fatal CD20- VS38c+ diffuse large-cell lymphoma with plasmablastic features, almost exclusively involving the jaw and oral mucosa in HIV-positive patients. METHODS: From 2001 to 2003 we evaluated 12 men with PBL, and report the pathology, clinical findings, treatment and outcome. Six of 12 were HIV-positive while among the others, one was post-renal transplant, one had ulcerative colitis and four had no known immunodeficiency. RESULTS: Tumor growth pattern, in general, showed cohesiveness and a starry-sky pattern; the morphology varied from typical plasmablastic to centroblastic cells. Partial immunophenotypes were (+/total): CD138, 11 of 12 (91.7%); MIB1 10 of 11 (4+, range 75-95%); p63/VS38c, nine of 10 (90%); EBV, eight of 11 (73%); LCA(CD45), two of 12 (16.7%); HHV8/LANA, zero of 10; ALK, zero of seven; and CD20, zero of 12. Three had stage IE and nine stage IV disease. Nine of 12 had an intermediate/high International Prognostic Index or high-risk disease. Computed tomography and positron emission tomography scan in four of 12 revealed extensive bone metastases. Eight of 12 are alive after treatment, with a median follow-up of 11+ months (range 1-24). Of the HIV-positive patients, five of six are alive with a median follow-up of 17 months. CONCLUSIONS: It appears that PBL are heterogenous in terms of clinical presentation and morphology. The outcome presented here is superior to that originally reported.
Subject(s)
Antigens, CD20/blood , HIV Infections/complications , Lymphoma, Large B-Cell, Diffuse/complications , Adult , Aged , Cohort Studies , Epstein-Barr Virus Infections/complications , Follow-Up Studies , Humans , Immunophenotyping , Lymphoma, Large B-Cell, Diffuse/immunology , Lymphoma, Large B-Cell, Diffuse/mortality , Male , Middle Aged , Survival Analysis , Survival RateABSTRACT
The ability to detect small amounts of materials, especially bacterial organisms, is important for medical diagnostics and national security issues. Engineered micromechanical systems provide one approach for constructing multifunctional, highly sensitive, real-time, immunospecific biological detectors. We present qualitative detection of specific Salmonella enterica strains using a functionalized silicon nitride microcantilever. Detection is achieved due to a change in the surface stress on the cantilever surface in situ upon binding of a small number of bacteria. Scanning electron micrographs indicate that less than 25 adsorbed bacteria are required for detection.
Subject(s)
Microscopy, Atomic Force/instrumentation , Microscopy, Atomic Force/methods , Salmonella enterica/isolation & purification , Salmonella enterica/ultrastructure , Antibodies, Bacterial , Biosensing Techniques/instrumentation , Biosensing Techniques/methods , Salmonella enterica/immunology , Silicon CompoundsABSTRACT
We have investigated the effects of humidity, tip speed, and dwell time on feature size during dip pen nanolithography. Our results indicate a transition between two distinct deposition regimes occurs at a dwell time independent of humidity. While feature size increases with humidity, the relative increase is independent of dwell time. The results are described by a model that accounts for detachment and reattachment at the tip. The model suggests that, at short dwell times (high speed), the most important parameter controlling the feature size is the activation energy for thiol detachment.
ABSTRACT
The nonlinear Poisson-Boltzmann (PB) equation is solved using Newton-Krylov iterations coupled with pseudo-transient continuation. The PB potential is used to compute the electrostatic energy and evaluate the force on a user-specified contour. The PB solver is embedded in a existing, 3D, massively parallel, unstructured-grid, finite element code. Either Dirichlet or mixed boundary conditions are allowed. The latter specifies surface charges, approximates far-field conditions, or linearizes conditions "regulating" the surface charge. Stability and robustness are proved using results for backward Euler differencing of diffusion equations. Potentials and energies of charged spheres and plates are computed and results compared to analysis. An approximation to the potential of the nonlinear, spherical charge is derived by combining two analytic formulae. The potential and force due to a conical probe interacting with a flat plate are computed for two types of boundary conditions: constant potential and constant charge. The second case is compared with direct force measurements by chemical force microscopy. The problem is highly nonlinear-surface potentials of the linear and nonlinear PB equations differ by over an order of magnitude. Comparison of the simulated and experimentally measured forces shows that approximately half of the surface carboxylic acid groups, of density 1/(0.2 nm2), ionize in the electrolyte implying surface charges of 0.4 C/m2, surface potentials of 0.27 V, and a force of 0.6 nN when the probe and plate are 8.7 nm apart.
ABSTRACT
The purpose of this study was to determine the efficacy and toxicity of the cyclophosphamide and fludarabine (CF) regimen in patients with newly diagnosed and relapsed/refractory mantle cell lymphoma (MCL). Thirty patients with pathologically confirmed MCL were treated with the CF regimen. Ten (33%) had no prior therapy, six (20%) had one previous regimen, and 14 (47%) received two or more prior regimens. Ninety cycles of CF with a median of 3 cycles/patient (range, 1-5 cycles) were administered to patients with MCL. Nine patients (30%) had a complete response (CR) and 10 (33%) had a partial response (PR) for an overall response rate (RR) of 63%. The median failure-free survival (FFS) and overall survival (OS) was 4.8 months and 17.5 months, respectively. When patients were analyzed based upon the number of previous treatments (0, 1, or 2 or more), those with no previous treatment (n=10) had an overall response of 100%, with 70% CR. The median FFS was 28.1 months and the median OS for this group has not been reached at 42.3+ months. Hematologic and infectious toxicity were the major toxicities encountered with the CF regimen. Grade 3-4 neutropenia, thrombocytopenia and anemia were seen in 50%, 37%, and 36% of patients, respectively. There were 13 episodes of grade 3 infections. There was no treatment related mortality, In conclusion, the high response rate associated with the CF regimen merits further investigation in previously untreated patients with MCL, particularly in those who are not candidates for aggressive therapy.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Lymphoma, Mantle-Cell/drug therapy , Vidarabine/analogs & derivatives , Aged , Aged, 80 and over , Antineoplastic Combined Chemotherapy Protocols/toxicity , Cyclophosphamide/administration & dosage , Disease-Free Survival , Female , Follow-Up Studies , Hematologic Diseases/diagnosis , Humans , Infections/chemically induced , Lymphoma, Mantle-Cell/complications , Lymphoma, Mantle-Cell/mortality , Male , Middle Aged , Remission Induction , Survival Rate , Treatment Outcome , Vidarabine/administration & dosageABSTRACT
Many living organisms contain biominerals and composites with finely tuned properties, reflecting a remarkable level of control over the nucleation, growth and shape of the constituent crystals. Peptides and proteins play an important role in achieving this control. But the general view that organic molecules affect mineralization through stereochemical recognition, where geometrical and chemical constraints dictate their binding to a mineral, seems difficult to reconcile with a mechanistic understanding, where crystallization is controlled by thermodynamic and kinetic factors. Indeed, traditional crystal growth models emphasize the inhibiting effect of so-called 'modifiers' on surface-step growth, rather than stereochemical matching to newly expressed crystal facets. Here we report in situ atomic force microscope observations and molecular modelling studies of calcite growth in the presence of chiral amino acids that reconcile these two seemingly divergent views. We find that enantiomer-specific binding of the amino acids to those surface-step edges that offer the best geometric and chemical fit changes the step-edge free energies, which in turn results in macroscopic crystal shape modifications. Our results emphasize that the mechanism underlying crystal modification through organic molecules is best understood by considering both stereochemical recognition and the effects of binding on the interfacial energies of the growing crystal.