Family Physicians' Barriers to Cancer Screening in Extremely Obese Patients

Extremely obese women are less likely than nonobese women to receive breast and cervical cancer screening examinations. Reasons for this disparity are unclear and may stem from patient and/or physician barriers. This sequential mixed‐methods study used individual in‐depth interviews of 15 family physicians followed by a mail survey of 255 family physicians (53% response rate) to understand the barriers they faced in performing cancer screening examinations in extremely obese women. Barriers fell into three main areas: (i) difficulty doing pelvic and breast exams; (ii) inadequate equipment; and (iii) challenges overcoming patient barriers and refusal. This led some physicians to avoid performing breast and pelvic examinations on extremely obese women. Having more knowledge about specific examination techniques was associated with less difficulty in palpating lumps on breast and pelvic examinations (P < 0.005). Physicians perceived that embarrassment, aversion to undressing, and avoidance of discussions related to their weight were the most frequent barriers extremely obese women had with getting physical examinations. Educating and/or motivating patients and addressing fears were strategies used most frequently when patients refused mammograms or Pap smears. Interventions focusing on physician barriers, such as educating them on specific examination techniques, obtaining adequate equipment and supplies, and providing resources to assist physicians in dealing with patient barriers and refusal, may be fruitful in increasing cancer screening rates in extremely obese patients. Future research studies testing the effectiveness of these strategies are needed to improve cancer outcomes in this high‐risk population.     

Human immunodeficiency virus type 1-derived lentivirus vectors pseudotyped with envelope glycoproteins derived from Ross River virus and Semliki Forest virus

Ross River virus (RRV) and Semliki Forest virus (SFV) are two alphaviruses that have a high degree of amino acid homology, as well as a very broad host range. We show here that envelope glycoproteins derived from both viruses can pseudotype human immunodeficiency virus type 1 (HIV-1)-derived lentivirus vectors. Both RRV and SFV glycoproteins considerably expand the host range of the lentivirus vector, and vectors can be efficiently concentrated by ultracentrifugation. A systematic analysis comparing the alphaviral glycoproteins to the vesicular stomatitis virus glycoprotein (VSV-G) revealed that lentivirus vectors incorporate RRV glycoproteins with an efficiency comparable to that of VSV-G. Both pseudotypes have comparable physical titers, but infectious titers with the RRV pseudotype are lower than with VSV-G. Incorporation of SFV glycoproteins into lentivirus vector is less efficient, leading to decreased physical and infectious titers. The transduction rates with VSV-G-, RRV-, and SFV-pseudotyped lentivirus vectors into adherent cell lines can be significantly increased by using a combination of Polybrene and plates coated with CH-296 recombinant fibronectin fragments. Together, our data suggest that RRV and SFV glycoproteins might be suitable as alternatives to VSV-G for pseudotyping lentivirus vectors.     

Cloning and expression of sheep renal K-CI cotransporter-1.

Sheep K-Cl cotransporter-1(shKCC1) cDNA was cloned from kidney by RT-PCR with an open reading frame of 3258 base pairs exhibiting 92%, 90%, 88% and 87% identity with pig, rabbit and human, rat and mouse KCC1 cDNAs, respectively, encoding an approximately 122 kDa polypeptide of 1086-amino acids. Hydropathy analysis reveals the familiar KCC1 topology with 12 transmembrane domains (TMDs) and the hydrophilic NH2-terminal (NTD) and COOH-terminal (CTD) domains both at the cytoplasmic membrane face. However, shKCC1 has two rather than one large extracellular loops (ECL): ECL3 between TMDs 5 and 6, and ECL6, between TMDs 11 and 12. The translated shKCC1 protein differs in 12 amino acid residues from other KCC1s, mainly within the NTD, ECL3, ICL4, ECL6, and CTD. Notably, a tyrosine residue at position 996 replaces aspartic acid conserved in all other species. Human embryonic kidney (HEK293) cells and mouse NIH/3T3 fibroblasts, transiently transfected with shKCCI-cDNA, revealed the glycosylated approximately 150 kDa proteins by Western blots and positive immunofluorescence-staining with polyclonal rabbit anti-ratKCC1 antibodies. ShKCC1 was functionally expressed in NIH/3T3 cells by an elevated basal Cl-dependent K influx measured with Rb as K-congener that was stimulated three-fold by the KCC-activator N-ethylmaleimide.     

Induction of UDPglucose dehydrogenase during development, organ culture, and exposure to phenobarbital. Its relation to levels of UDPglucuronic acid and overall glucuronidation in chicken and mouse.

Liver UDPglucose in early chick-enbryo has, by the 19th day of incubation, reached levels existing in young hatched (White Leghorn) chicks. In developing ASH/TO mouse liver, the dehydrogenase is low, but increases sharply at late foetal and weaning stages; adult activity is greater in females than males. The UDPglucuronic acid content of embryo liver from at least 12 days resembles that of adult chicken; in mouse liver it rises over birth and infancy. These differences in relative rates of development of enzyme and nucleotide in the 2 species can explain why overall glucuronidation by liver appears in chick rapidly after hatching, but in mouse only gradually during infancy. UDPglucose dehydrogenase increases in embryo liver, probably by induction, 2-3-fold during culture with phenobarbital and some 5-fold when exposed to the drug in ovo. Phenobarbital treatment also increases the enzyme in late foetal and adult mice, abolishing the sex difference. Differences between induction of UDPglucose dehydrogenase and UDPglucuronyl transferase during development, culture and phenobarbital treatment indicate that control mechanism for these two enzymes are not directly linked.     

Robotic Production of Cancer Cell Spheroids with an Aqueous Two-phase System for Drug Testing

Cancer cell spheroids present a relevant in vitro model of avascular tumors for anti-cancer drug testing applications. A detailed protocol for producing both mono-culture and co-culture spheroids in a high throughput 96-well plate format is described in this work. This approach utilizes an aqueous two-phase system to confine cells into a drop of the denser aqueous phase immersed within the second aqueous phase. The drop rests on the well surface and keeps cells in close proximity to form a single spheroid. This technology has been adapted to a robotic liquid handler to produce size-controlled spheroids and expedite the process of spheroid production for compound screening applications. Spheroids treated with a clinically-used drug show reduced cell viability with increase in the drug dose. The use of a standard micro-well plate for spheroid generation makes it straightforward to analyze viability of cancer cells of drug-treated spheroids with a micro-plate reader. This technology is straightforward to implement both robotically and with other liquid handling tools such as manual pipettes.     

Recombinant human PPAR-beta/delta ligand-binding domain is locked in an activated conformation by endogenous fatty acids

High-resolution crystallographic structures of recombinant human peroxisome proliferator-activated receptor ligand-binding domain (isotype beta/delta) reveal a fatty acid in the binding site. Mass spectrometry confirmed the presence of C16:0, C16:1, C18:0 and C18:1 in a ratio of approximately 3:2:1:4 with 11, Z-octadecenoic acid (cis-vaccenic acid) identified as the predominant species. These are endogenous fatty acids acquired from the bacterial expression system, and serve to lock the ligand-binding domain into the activated conformation. A requirement for crystal growth, the additive n-heptyl-beta-d-glucopyranoside, binds near the activation function helix where recognition of co-activator proteins occurs. Our observations suggest potential physiological ligands for human PPAR-beta/delta and highlight that reported binding studies must be treated with caution unless endogenous fatty acids have been removed from the sample prior to analysis.