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.

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.

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.

An alternative laboratory designed to address ethical concerns associated with traditional TAS2R38 student genotyping.

The TAS2R38 alleles that code for the PAV/AVI T2R38 proteins have long been viewed as benign taste receptor variants. However, recent studies have demonstrated an expanding and medically relevant role for TAS2R38. The AVI variant of T2R38 is associated with an increased risk of both colorectal cancer and Pseudomonas aeruginosa-associated sinus infection and T2R38 variants have been implicated in off-target drug responses.

Anticoagulant factor V: factors affecting the integration of novel scientific discoveries into the broader framework.

Since its initial discovery in the 1940s, factor V has long been viewed as an important procoagulant protein in the coagulation cascade. However, in the later part of the 20th century, two different scientists proposed novel anticoagulant roles for factor V. Philip Majerus proposed the first anticoagulant function for factor V in 1983, yet ultimately it was not widely accepted by the broader scientific community.

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.

Variation in the ligand binding domains of the CD94/NKG2 family of receptors in the squirrel monkey.

Natural killer cells are regulated, in part, by cell surface expression of the inhibitory CD94/NKG2A heterodimer and the activating CD94/NKG2C heterodimer. In the present study, we characterize the CD94/NKG2 family in the squirrel monkey, a New World monkey species. Full-length CD94, NKG2A, and NKG2CE complementary deoxyribonucleic acid molecules were identified in three unrelated squirrel monkeys.

Evidence of NK cell dysfunction in SIV-infected rhesus monkeys: impairment of cytokine secretion and NKG2C/C2 expression.

Defects in the adaptive immune response have been extensively characterized in human immunodeficiency virus type-1 (HIV-1)-infected individuals; however, much less is known about the function of natural killer (NK) cells during the course of HIV-1 infection. In the present study, we demonstrate that the NK cells from simian immunodeficiency virus (SIV)-infected rhesus monkeys are significantly impaired in their ability to secrete IFN-gamma, TNF-alpha, and IL-2, while NK cell function in SIV-infected long-term non-progressor monkeys is similar to that of normal monkeys. These findings suggest that abnormal NK cell activity may contribute to the global immune dysfunction observed in HIV-1-infected individuals.

Molecular determinants regulating the pairing of NKG2 molecules with CD94 for cell surface heterodimer expression.

The lytic capacity of a NK cell is regulated, in part, by the balance in cell surface expression between inhibitory CD94/NKG2A and activating CD94/NKG2C heterodimers. We demonstrate that, in the absence of DAP12, rhesus monkey NKG2A is preferentially expressed at the cell surface with CD94 due to a single amino acid difference in the transmembrane of NKG2A and NKG2C. Furthermore, in the context of an NKG2A transmembrane, the stalk domain of NKG2C was found to enhance heterodimer formation with CD94 compared with the stalk domain of NKG2A.