Impacts of arsenic on Rad18 and translesion synthesis.

Arsenite interferes with DNA repair protein function resulting in the retention of UV-induced DNA damage. Accumulated DNA damage promotes replication stress which is bypassed by DNA damage tolerance pathways such as translesion synthesis (TLS). Rad18 is an essential factor in initiating TLS through PCNA monoubiquitination and contains two functionally and structurally distinct zinc fingers that are potential targets for arsenite binding. Arsenite treatment displaced zinc from endogenous Rad18 protein and mass spectrometry analysis revealed arsenite binding to both the Rad18 RING finger and UBZ domains. Consequently, arsenite inhibited Rad18 RING finger dependent PCNA monoubiquitination and polymerase eta recruitment to DNA damage in UV exposed keratinocytes, both of which enhance the bypass of cyclobutane pyrimidine dimers during replication. Further analysis demonstrated multiple effects of arsenite, including the reduction in nuclear localization and UV-induced chromatin recruitment of Rad18 and its binding partner Rad6, which may also negatively impact TLS initiation. Arsenite and Rad18 knockdown in UV exposed keratinocytes significantly increased markers of replication stress and DNA strand breaks to a similar degree, suggesting arsenite mediates its effects through Rad18. Comet assay analysis confirmed an increase in both UV-induced single-stranded DNA and DNA double-strand breaks in arsenite treated keratinocytes compared to UV alone. Altogether, this study supports a mechanism by which arsenite inhibits TLS through the altered activity and regulation of Rad18. Arsenite elevated the levels of UV-induced replication stress and consequently, single-stranded DNA gaps and DNA double-strand breaks. These potentially mutagenic outcomes support a role for TLS in the cocarcinogenicity of arsenite.

Relationship between documentation method and quality of chronic disease visit notes.

OBJECTIVE: To assses the relationship between methods of documenting visit notes and note quality for primary care providers (PCPs) and specialists, and to determine the factors that contribute to higher quality notes for two chronic diseases. METHODS: Retrospective chart review of visit notes at two academic medical centers. Two physicians rated the subjective quality of content areas of the note (vital signs, medications, lifestyle, labs, symptoms, assessment & plan), overall quality, and completed the 9 item Physician Documentation Quality Instrument (PDQI-9). We evaluated quality ratings in relation to the primary method of documentation (templates, free-form or dictation) for both PCPs and specialists. A one factor analysis of variance test was used to examine differences in mean quality scores among the methods. RESULTS: A total of 112 physicians, 71 primary care physicians (PCP) and 41 specialists, wrote 240 notes. For specialists, templated notes had the highest overall quality scores (p≤0.001) while for PCPs, there was no statistically significant difference in overall quality score. For PCPs, free form received higher quality ratings on vital signs (p = 0.01), labs (p = 0.002), and lifestyle (p = 0.002) than other methods; templated notes had a higher rating on medications (p≤0.001). For specialists, templated notes received higher ratings on vital signs, labs, lifestyle and medications (p = 0.001). DISCUSSION: There was no significant difference in subjective quality of visit notes written using free-form documentation, dictation or templates for PCPs. The subjective quality rating of templated notes was higher than that of dictated notes for specialists. CONCLUSION: As there is wide variation in physician documentation methods, and no significant difference in note quality between methods, recommending one approach for all physicians may not deliver optimal results.

What Affects Clinicians' Usage of Health Information Exchange?

BACKGROUND: The ability to electronically exchange health information among healthcare providers holds enormous promise to improve care coordination and reduce costs. Provider-to-provider data exchange is an explicit goal of the American Recovery and Reinvestment Act of 2009 and may be essential for the long-term success of the Affordable Care Act of 2010. However, little is known about what factors affect clinicians' usage of health information exchange (HIE) functionality. OBJECTIVE: To identify factors that affect clinicians' HIE usage - in terms of frequency of contributing data to and accessing data from aggregate patient records - and suggest policies for fostering its usage. METHODS: We performed a qualitative study using grounded theory by interviewing clinician-users and HIE staff of one operational HIE which supported aggregate patient record functionality. Fifteen clinicians were interviewed for one hour each about what factors affect their HIE usage. Five HIE staff were asked about technology and training issues to provide context. Interviews were recorded, transcribed and analyzed. Recruitment excluded clinicians with little or no familiarity with the HIE and was restricted to one community and a small number of specialties. RESULTS: Clinicians were motivated to access the HIE by perceived improvements in care quality and time savings, but their motivation was moderated by an extensive list of factors including gaps in data, workflow issues and usability issues. HIE access intensities varied widely by clinician. Data contribution intensities to the HIE also varied widely and were affected by billing concerns and time constraints. CONCLUSIONS: Clinicians, EHR and HIE product vendors and trainers should work toward integrating HIE into clinical workflows. Policies should create incentives for HIE organizations to assist clinicians in using HIE, develop measures of HIE contributions and accesses, and create incentives for clinicians to contribute data to HIEs.

Keeping patients active and current in a patient portal.

Maintaining current contact information is crucial to the effectiveness of communication via patient portals. Patients who visit a portal infrequently, or whose contact information is not updated, may miss administrative notices or clinical messages from their doctor's office. We invited patients to review and update their contact information via a broadcast e-mail message sent to all patients in the patient portal, Patient Gateway. We report the effectiveness of the broadcast message approach to reaching registered patients.

The role of primary care non-physician clinic staff in e-mail communication with patients.

BACKGROUND: Few studies have explicitly addressed how e-mail technology may affect non-physician clinic staff, even though these staff typically manage tasks well suited to e-mail communication such as requests for prescription renewals, laboratory and test results, and referral authorizations. GOAL: We conducted a survey of staff members at 10 primary care clinics in Boston to further evaluate non-physician staff attitudes towards e-mail use with patients. We subsequently re-surveyed staff at three of these clinics after the implementation of Patient Gateway, an application designed to facilitate secure electronic communication between patients and the clinics. RESULTS: Before Patient Gateway implementation, 88% of surveyed staff were already using e-mail at least once a day for work-related communication. Many of these staff members (24%) were already using e-mail with patients. Forty-eight percent of staff members thought that increasing e-mail use with patients could improve the quality of care their practices delivered. However, staff reported having some hesitations about increasing e-mail use with patients, mostly relating to security, confidentiality, and workload. After Patient Gateway implementation, users reported high satisfaction with the application and staff in general (users and non-users of Patient Gateway) felt more enthusiastic about increasing e-mail use with patients. CONCLUSIONS: In order to maximize the potential of staff-patient e-mail, it is important that concerns relating to security, confidentiality, and workflow are addressed, and patients must be given guidelines for the appropriate use of e-mail. Secure applications designed with these issues in mind are likely to be well received by staff members, and in turn physicians.

The molecular chaperone Hsp90 is required for signal transduction by wild-type Hck and maintenance of its constitutively active counterpart.

We have investigated the relationship between the molecular chaperone heat shock protein-90 (Hsp90) and the signal transducing capacity of the Src-family kinase Hck. Inhibition of Hsp90 with geldanamycin suppressed the ability of bacterial lipopolysaccharide to enhance the cell adhesion properties of macrophages, a phenomenon most likely explained by the reduced expression and activity of Hck in macrophages lacking Hsp90 function. The contribution of Hsp90 to signal transduction by Hck was biochemically dissected further by examining its role in the de novo folding and maintenance of wild-type Hck and its constitutively active counterpart, Hck499F. The folding of nascent wild-type Hck and Hck499F into catalytically active conformations, and their accumulation in cells was found to be dependent on Hsp90 function. Notably, mature Hck499F had a greater requirement for on-going support from Hsp90 than did mature wild-type Hck. This particular finding might have important implications for our understanding of the evolution of oncogenic protein kinases.

p50(cdc37) is a nonexclusive Hsp90 cohort which participates intimately in Hsp90-mediated folding of immature kinase molecules.

Hsp90 and p50(cdc37) provide a poorly understood biochemical function essential to certain protein kinases, and recent models describe p50(cdc37) as an exclusive hsp90 cohort which links hsp90 machinery to client kinases. We describe here the recovery of p50(cdc37) in immunoadsorptions directed against the hsp90 cohorts FKBP52, cyp40, p60HOP, hsp70, and p23. Additionally, monoclonal antibodies against FKBP52 coadsorb maturation intermediates of the hsp90-dependent kinases p56(lck) and HRI, and the presence of these maturation intermediates significantly increases the representation of p50(cdc37) and hsp90 on FKPB52 machinery. Although the native heterocomplex between hsp90 and p50(cdc37) is salt-labile, their dynamic interactions with kinase substrates produce kinase-chaperone heterocomplexes which are highly salt-resistant. The hsp90 inhibitor geldanamycin does not directly disrupt the native association of hsp90 with p50(cdc37) per se, but does result in the formation of salt-labile hsp90-kinase heterocomplexes which lack the p50(cdc37) cohort. We conclude that p50(cdc37) does not simply serve as a passive structural bridge between hsp90 and its kinase substrates; instead, p50(cdc37) is a nonexclusive hsp90 cohort which responds to hsp90's nucleotide-regulated conformational switching during the generation of high-affinity interactions within the hsp90-kinase-p50(cdc37) heterocomplex.

Feline lymphoma (145 cases): proliferation indices, cluster of differentiation 3 immunoreactivity, and their association with prognosis in 90 cats.

Paraffin-embedded, formalin-fixed tissue samples from 145 cats with lymphoma were analyzed for cluster of differentiation 3 (CD3, a surface antigen) immunoreactivity, argyrophilic nucleolar organizer region (AgNOR) frequency, and proliferating cell nuclear antigen labeling index (PCNA-LI). This information along with signalment, anatomic site, and feline leukemia virus (FeLV) antigen status was used to determine the potential of these indicators to predict response to therapy, remission, and survival times, and to characterize cats with lymphoma in the era of general availability of FeLV testing and vaccination. Alimentary lymphoma, primarily occurring in older, FeLV-negative cats, was the most common site of involvement. Although the majority of tumors from FeLV-positive cats were CD3-immunoreactive, only one half of CD3-immunoreactive tumors occurred in FeLV-positive cats. Median remission duration and survival times were 126 days and 143 days, respectively, for all cats. Measures of tumor cell proliferation (AgNOR frequency and PCNA-LI) and CD3-immunoreactivity were not predictive of outcome. When all prognostic factors were accounted for by multivariate analysis, response to therapy, FeLV status, and clinical substage were predictive of outcome. FeLV-negative cats that achieved a complete response following induction therapy were likely to have durable (i.e., > 6-month) responses, particularly when doxorubicin was included in the chemotherapy protocol. However, FeLV-positive cats had significantly shorter remission and survival times with available chemotherapeutic protocols.

Treatment of systemic hypertension in cats with amlodipine besylate.

Amlodipine besylate, a calcium channel blocker, was used to treat (mean +/- standard deviation [SD], 127 +/- 68 days) 12 cats with systemic hypertension. Amlodipine was administered orally at a dosage of 0.625 mg per cat (range, 0.08 to 0.23 mg/kg body weight; mean dose +/- SD, 0.17 +/- 0.04 mg/kg body weight) once daily as a single agent. Average indirect systolic blood pressure measurements in the 12 cases decreased significantly from 198 to 155 mmHg during amlodipine treatment. Significant changes in body weight and serum creatinine and potassium concentrations were not detected. Amlodipine appears to be a safe and effective oral treatment for systemic hypertension in cats when used chronically once daily as a single agent.

Frequency of argyrophilic nucleolar organizer regions in fine-needle aspirates and biopsy specimens from mast cell tumors in dogs.

OBJECTIVE: To determine for mast cell tumors in dogs whether frequency of argyrophilic nucleolar organizer regions (AgNOR) determined by examining fine-needle aspirates (FNA) correlated with frequencies determined by examining biopsy specimens or with histologic grade. DESIGN: Case series. ANIMALS: 25 dogs with 32 histologically confirmed tumors. PROCEDURE: Biopsy specimens and FNA were collected from each tumor. Histologic grade and AgNOR frequency were determined. RESULTS: Frequency of AgNOR in FNA was significantly correlated with frequency in biopsy specimens and was significantly associated with histologic grade of the tumor. CLINICAL IMPLICATIONS: Determining AgNOR frequency in FNA of mast cell tumors in dogs is a rapid, minimally invasive means of obtaining information that potentially could be used to help predict biological behavior of the tumor and to guide clinicians and owners in making decisions about further diagnostic tests and treatment.

Meiotic indices in the oligospermic male.

Thirty-four oligospermic males were evaluated by determining the meiotic index in testicular biopsy specimens. Only 1 patient of 10 with a meiotic index of less than 15 achieved pregnancy, whereas 16 of 24 patients with a meiotic index of more than 15 had a successful outcome. Corresponding increases in the semenogram were also noted to be related to the meiotic index.

Meiotic figures in the testicular biopsy of subfertile males.

The phases and sequence of meiotic division are herein reviewed and illustrated as they occur in the human testis. Normally all phases of meiosis can be identified, and arrest at a phase is indicative of faulty spermatogenesis. The correlation of these arrest patterns with the clinical course and response to clinical therapy is now in progress. These meiotic studies can be undertaken in any laboratory with cytogenetic capabilities, and this study is intended to serve as a base line illustration of the normal.

A study of meiotic preparation of human spermatocytes and their relationship to infertility.

Although our experience is based on a small series of 50 cases we believe that several points can be made. Meiotic preparations can be performed in any competent cytogenetic laboratory. These preparations appear to yield more specific information as to the site of arrest and may be more reliable than the static testicular biopsy to appraise the true status of spermatogenesis. With these facts in mind a more accurate prognosis and therapeutic regimen can be realized.

Application of the singular perturbation method to reaction kinetics.

The purpose of this paper is to show how to apply the singular perturbation method to the rate equations in reaction kinetics that involve different time scales. The Lindemann scheme has been chosen for illustration, and the steady-state and equilibrium approximations used in the Lindemann scheme are discussed.

Stochastic Model of Unimolecular Reactions and the RRKM Theory.

A stochastic model of unimolecular reactions has been adopted for investigation of the validity and limitation of the RRKM theory. The error caused by the steady-state approximation for distribution of energized molecules is small, while the assumption of the internal energy equilibration of energized molecules might cause serious errors for reactions of low activation energies.