Diagnostic Uncertainty, Microbes, and the Isolation of People with Cystic Fibrosis.

The framing of cystic fibrosis (CF) changed from a strictly genetic disease in the mid- to late-twentieth century to a genetic/infectious hybrid of sorts by the early twenty-first century, providing an opportunity to examine the nature of disease definition in medicine. Respiratory infections had long been associated with CF, yet it was not until the late twentieth century that many physicians became concerned about the possibility of patient-to-patient transmission of a particularly pathogenic microorganism. Initially termed Pseudomonas cepacia, the microbe was linked to rapid decline and even death in some people with CF, and early efforts to prevent its spread included the segregation of infected individuals. However, soon after segregation was implemented in a range of medical and social contexts, physicians began to suspect that people with CF did not always test positive for P. cepacia in the setting of infection, due to challenges isolating and identifying the microorganism in the laboratory. These sources of diagnostic uncertainty, coupled with the severe health outcomes associated with P. cepacia infection, prompted those in leadership positions to treat all people with CF as a potential source of contagion and restrict their in-person interactions, a practice that has had a profound impact on the CF community.

The Mist Tent: An Analysis of Therapeutic Change in the History of Cystic Fibrosis Care.

Mist tent therapy for cystic fibrosis went through a rise and fall in popularity between the 1950s and 1970s, providing an opportunity to explore the nature of therapeutic change in medicine. The therapy "worked" in the context of a particularly grim life expectancy in the early 1950s and in the setting of a comprehensive therapeutic program that began in Cleveland in 1957. Although clinical studies published in the 1970s provided evidence that mist tents were ineffective or even harmful, these later studies were not necessarily more robust than earlier studies that provided evidence of mist tent efficacy, suggesting that other factors may have also contributed to mist tent abandonment. In fact, the unpalatable nature of mist tent therapy, which was described by one doctor as akin to incarceration, and studies that questioned the theoretical underpinnings of the therapy also played important roles in the eventual abandonment of mist tents.

Blobel and Sabatini's "Beautiful Idea": Visual Representations of the Conception and Refinement of the Signal Hypothesis.

In 1971, Günter Blobel and David Sabatini proposed a novel and quite speculative schematic model to describe how proteins might reach the proper cellular location. According to their proposal, proteins destined to be secreted from the cell contain a "signal" to direct their release. Despite the fact that Blobel and Sabatini presented their signal hypothesis as a "beautiful idea" not grounded in experimental evidence, they received criticism from other scientists who opposed such speculation. Following the publication of the 1971 model, Blobel persisted in conducting experiments and revising the model to incorporate new data. In fact, over the period of 1975-1984, Blobel and colleagues published five subsequent schematic models of the signal hypothesis, each revised based on new laboratory evidence. I propose that the original 1971 model can be viewed as an epistemic creation. Additionally, analysis of the subsequent schematic diagrams over the period of 1975-1984 allows one to track Blobel's changing conception of an epistemic object over time. Furthermore, the entire series of schematic diagrams presented by Blobel from 1971 to 1984 allow one to visualize the initial conception and subsequent reworking of a scientific theory. In 1999, Blobel was awarded the Nobel Prize in Physiology or Medicine for his work on the signal hypothesis, which was ultimately supported by experimental evidence gathered after the speculative model was published.

An analysis of US fertility centre educational materials suggests that informed consent for preimplantation genetic diagnosis may be inadequate.

The use of preimplantation genetic diagnosis (PGD) has expanded both in number and scope over the past 2 decades. Initially carried out to avoid the birth of children with severe genetic disease, PGD is now used for a variety of medical and non-medical purposes. While some human studies have concluded that PGD is safe, animal studies and a recent human study suggest that the embryo biopsy procedure may result in neurological problems for the offspring. Given that the long-term safety of PGD has not been clearly established in humans, this study sought to determine how PGD safety is presented to prospective patients by means of a detailed website analysis. The websites of 262 US fertility centres performing PGD were analysed and comments about safety and risk were catalogued. Results of the analysis demonstrated that 78.2% of centre websites did not mention safety or risk of PGD at all. Of the 21.8% of centres that did contain safety or risk information about PGD, 28.1% included statements highlighting the potential risks, 38.6% presented information touting the procedure as safe and 33.3% included statements highlighting potential risks and the overall safety of the procedure. Thus, 86.6% of PGD-performing centres state that PGD is safe and/or fail to disclose any risks on their websites despite the fact that the impact of the procedure on the long-term health of offspring is unproven. This lack of disclosure suggests that informed consent is inadequate; this study examines numerous factors that are likely to inhibit comprehensive discussions of safety.