Uncommon etiology of gastrointestinal bleeding: duodenal metastases from renal cell carcinoma

Because of its unpredictable behavior, renal cell carcinoma is one of the most controversial neoplasms. On the one hand, patients frequently show metastases at diagnosis because of its slight manifestations, while on the other, the neoplasm can remain stable after nephrectomy and can then metastasize many years later. When this happens, the metastases usually involve more than 2 organs. The most frequent sites of metastases are the lung and lymph nodes, followed by the bones and liver, while duodenal involvement is rare. Indeed, intestinal metastases are found in only 2% of autopsies and of these, renal cell carcinoma metastases account for 7.1%. We present a case of a solitary late recurrence presenting as upper gastrointestinal bleeding 19 years after nephrectomy for clear cell renal carcinoma.     

Dpp signaling and the induction of neoplastic tumors by caspase-inhibited apoptotic cells in Drosophila

In Drosophila, stresses such as x-irradiation or severe heat shock can cause most epidermal cells to die by apoptosis. Yet, the remaining cells recover from such assaults and form normal adult structures, indicating that they undergo extra growth to replace the lost cells. Recent studies of cells in which the cell death pathway is blocked by expression of the caspase inhibitor P35 have raised the possibility that dying cells normally regulate this compensatory growth by serving as transient sources of mitogenic signals. Caspase-inhibited cells that initiate apoptosis do not die. Instead, they persist in an "undead" state in which they ectopically express the signaling genes decapentaplegic (dpp) and wingless (wg) and induce abnormal growth and proliferation of surrounding tissue. Here, using mutations to abolish Dpp and/or Wg signaling by such undead cells, we show that Dpp and Wg constitute opposing stimulatory and inhibitory signals that regulate this excess growth and proliferation. Strikingly, we also found that, when Wg signaling is blocked, unfettered Dpp signaling by undead cells transforms their neighbors into neoplastic tumors, provided that caspase activity is also blocked in the responding cells. This phenomenon may provide a paradigm for the formation of neoplastic tumors in mammalian tissues that are defective in executing the cell death pathway. Specifically, we suggest that stress events (exposure to chemical mutagens, viral infection, or irradiation) that initiate apoptosis in such tissues generate undead cells, and that imbalances in growth regulatory signals sent by these cells can induce the oncogenic transformation of neighboring cells.     

Enhancing Usability of Appointment Reminders: Qualitative Interviews of Patients Receiving Care in the Veterans Health Administration

BackgroundNo-shows are a persistent and costly problem in all healthcare systems. Because forgetting is a common cause of no-shows, appointment reminders are widely used. However, qualitative research examining appointment reminders and how to improve them is lacking.ObjectiveTo understand how patients experience appointment reminders as part of intervention development for a pragmatic trial of enhanced appointment reminders.DesignQualitative content analysisParticipantsTwenty-seven patients at a single Department of Veterans Affairs hospital and its satellite clinicsApproachWe conducted five waves of interviews using rapid qualitative analysis, in each wave continuing to ask veterans about their experience of reminders. We double-coded all interviews, used deductive and inductive content analysis to identify themes, and selected quotations that exemplified three themes (limitations, strategies, recommendations).Key ResultsInterviews showed four limitations on the usability of current appointment reminders which may contribute to no-shows: (1) excessive information within reminders; (2) frustrating telephone systems when calling in response to an appointment reminder; (3) missing or cryptic information about clinic logistics; and (4) reminder fatigue. Patients who were successful at keeping appointments often used specific strategies to optimize the usability of reminders, including (1) using a calendar; (2) heightening visibility; (3) piggybacking; and (4) combining strategies. Our recommendations to enhance reminders are as follows: (1) mix up their content and format; (2) keep them short and simple; (3) add a personal touch; (4) include specifics on clinic location and contact information; (5) time reminders based on the mode of delivery; and (6) hand over control of reminders to patients.ConclusionsAppointment reminders are vital to prevent no-shows, but their usability is not optimized for patients. There is potential for healthcare systems to modify several aspects of the content, timing, and delivery of appointment reminders to be more effective and patient-centered.Electronic supplementary materialThe online version of this article (10.1007/s11606-020-06183-5) contains supplementary material, which is available to authorized users.KEY WORDS: access to care, no-shows, missed appointments, reminder, military veterans     

First and second thermodynamic law analyses applied to spark ignition engines modelling and emissions prediction

A mathematical and numerical model of flow and combustion process for spark ignition engines is developed using the principles of the first and second law of thermodynamic. Availability (exergy) analysis is applied to cylinder of a spark ignition engine during the combustion process using a two-zone combustion model. Special attention is given to identification and quantification of irreversibility of combustion process and energy available basing on the isooctane fuel explosion. To predict emissions generation (greenhouse gases) a skeletal mechanism including 32 species and 61 reactions was developed and tested for different engine operations and exergy destructions.     

An anti-CD45RO immunotoxin kills latently infected human immunodeficiency virus (HIV) CD4 T cells in the blood of HIV-positive persons.

Highly active antiretroviral therapy has decreased the morbidity and mortality of human immunodeficiency virus (HIV) infection, but latently infected cells remain for prolonged periods. CD4(+) CD45RO(+) T cells are a major latent virus reservoir in HIV-infected persons. Replication-competent, latently HIV-infected T cells can be generated in vitro by infecting peripheral blood mononuclear cells with HIV and then eliminating the HIV-producing cells with an anti-CD25 immunotoxin (IT). The CD25(-) latently infected cells then can be eliminated with an anti-CD45RO IT. This study determined whether this IT also could kill latently infected CD4 T cells from HIV-infected persons with or without detectable plasma viremia. The results show that ex vivo treatment of cells from HIV-positive persons by anti-CD45RO IT reduces the frequency of both productively and latently infected cells. In contrast, CD4(+) CD45RA(+) naive T cells and a proportion of CD4(+) CD45RO(lo) memory T cells are spared.     

Tuberculosis recurrences: reinfection plays a role in a population whose clinical/epidemiological characteristics do not favor reinfection

BACKGROUND: Tuberculosis (TB) recurrences can be due to either reactivation by the same strain (standard assumption) or reinfection by a new strain. Reinfection has mainly been studied in selected populations with a high risk of reexposure to TB. Our aim was to analyze the role of reinfection in TB recurrences in unselected populations, without the clinical/epidemiological circumstances that favor the involvement of a new different strain of Mycobacterium tuberculosis in the recurrence. METHODS: A molecular typing analysis was performed with 92 sequential isolates of M tuberculosis from 43 patients with recurrent TB, during a 12-year period. The subjects were both positive and negative for the human immunodeficiency virus, most did not adhere to anti-TB therapy, and they lived in an area with a moderate incidence of TB. Recurrence was considered as being caused by reinfection when the molecular fingerprints for the strains involved in the sequential episodes of TB were different. RESULTS: In 14 (33%) of the 43 patients, different M tuberculosis strains were involved in the first and in subsequent episodes of TB. Reinfection was found for patients who were both positive and negative for the human immunodeficiency virus, and most patients did not adhere to anti-TB therapy. Differences between the reinfection and reactivation groups were not significant (P =.77) according to the time interval between episodes. CONCLUSIONS: Reinfection plays an important role in recurrent TB in a population without the clinical/epidemiological circumstances that are usually assumed to favor it. Reinfection should, thus, be considered as a cause of TB recurrences in a wider context than before.