Tumor containment: a more general mathematical analysis.

Clinical and pre-clinical data suggest that treating some tumors at a mild, patient-specific dose might delay resistance to treatment and increase survival time. A recent mathematical model with sensitive and resistant tumor cells identified conditions under which a treatment aiming at tumor containment rather than eradication is indeed optimal. This model however neglected mutations from sensitive to resistant cells, and assumed that the growth-rate of sensitive cells is non-increasing in the size of the resistant population.

Targeting immunosuppressive Ly6C+ classical monocytes reverses anti-PD-1/CTLA-4 immunotherapy resistance.

Introduction: Despite significant clinical advancement with the use of immune checkpoint blockade (ICB) in non-small cell lung cancer (NSCLC) there are still a major subset of patients that develop adaptive/acquired resistance. Understanding resistance mechanisms to ICB is critical to developing new therapeutic strategies and improving patient survival. The dynamic nature of the tumor microenvironment and the mutational load driving tumor immunogenicity limit the efficacy to ICB.

Evolution of a structured cell population endowed with plasticity of traits under constraints on and between the traits.

Confronted with the biological problem of managing plasticity in cell populations, which is in particular responsible for transient and reversible drug resistance in cancer, we propose a rationale consisting of an integro-differential and a reaction-advection-diffusion equation, the properties of which are studied theoretically and numerically. By using a constructive finite volume method, we show the existence and uniqueness of a weak solution and illustrate by numerical approximations and their simulations the capacity of the model to exhibit divergence of traits. This feature may be theoretically interpreted as describing a physiological step towards multicellularity in animal evolution and, closer to present-day clinical challenges in oncology, as a possible representation of bet hedging in cancer cell populations.

Factors Influencing COVID-19 Vaccine Acceptance in the Workplace: Results From a Rapid Survey at 2 Corporations in Los Angeles County, California, 2021.

Objectives: Achieving widespread vaccine acceptance across various employment sectors is key to a successful public health response to COVID-19, but little is known about factors influencing vaccine acceptance among essential non-health care workers. We examined factors influencing vaccine acceptance among a sample of essential non-health care workers in California.

Methods: We conducted a survey in early spring 2021 at 2 corporations in Los Angeles County, California, to identify and describe factors influencing vaccine acceptance and the ability of incentives to increase this acceptance.

Regionally nested patterns of fish assemblages in floodplain lakes of the Magdalena river (Colombia).

We investigated if fish assemblages in neotropical floodplain lakes (cienagas) exhibit nestedness, and thus offer support to the managers of natural resources of the area for their decision making. The location was floodplain lakes of the middle section of the Magdalena river, Colombia. We applied the nested subset analysis for the series of 30 cienagas (27 connected to the main river and three isolated).

Emergency contraception under attack in Latin America: response of the medical establishment and civil society.

The concept that it is possible to prevent a pregnancy after coitus is not new, but has gained prominence over the last 10-15 years. It provides a second chance to women who do not want to get pregnant and who, voluntarily or not, have had unprotected intercourse. Emergency contraception has been under strong attack by the Catholic church and anti-choice organisations in Latin America, who claim that the interference with implantation of the fertilised ovum is equivalent to an early abortion.

Ototoxic occupational exposures for a stock car racing team: I. Noise surveys.

The National Institute for Occupational Safety and Health (NIOSH) surveyed noise exposure for a professional stock car team at their race shop and during two races at one racetrack. At the team's shop, area sound pressure levels (SPLs) were measured for various work tasks. Equivalent levels (Leqs) ranged from 58 to 104 decibels, A-weighted (dBA).

Ototoxic occupational exposures for a stock car racing team: II. chemical surveys.

The National Institute for Occupational Safety and Health (NIOSH) conducted a series of surveys to evaluate occupational exposure to noise and potentially ototoxic chemical agents among members of a professional stock car racing team. Exposure assessments included site visits to the team's race shop and a worst-case scenario racetrack. During site visits to the race team's shop, area samples were collected to measure exposures to potentially ototoxic chemicals, including, organic compounds (typical of solvents), metals, and carbon monoxide (CO).

Tuberculosis exposure of patients and staff in an outpatient hemodialysis unit.

Background: Patients receiving hemodialysis are generally considered to be at increased risk of developing tuberculosis (TB). We evaluated a 13-station chronic outpatient hemodialysis unit associated with a community hospital in northern California. Within 6 months, there were 2 incident source cases in the unit of active smear positive pulmonary tuberculosis; the first in a health care worker (HCW), diagnosed April 3, 1998, and the second in a patient undergoing dialysis treatment in October 1998.

Pharmacokinetic study of different dosing regimens of levonorgestrel for emergency contraception in healthy women.

Background: Levonorgestrel (LNG) is a commonly used progestin for emergency contraception; however, little is known about its pharmacokinetics and optimal dose for use.

Methods: Serum levels of LNG and sex hormone-binding globulin (SHBG) were measured in five women who received three different regimens: A: 0.75 mg LNG twice with a 12 h interval; B: 0.