Organellar Contacts of Milk Lipid Droplets

Milk-secreting epithelial cells of the mammary gland are functionally specialized for the synthesis and secretion of large quantities of neutral lipids, a major macronutrient in milk from most mammals. Milk lipid synthesis and secretion are hormonally regulated and secretion occurs by a unique apocrine mechanism. Neutral lipids are synthesized and packaged into perilipin-2 (PLIN2) coated cytoplasmic lipid droplets within specialized cisternal domains of rough endoplasmic reticulum (ER). Continued lipid synthesis by ER membrane enzymes and lipid droplet fusion contribute to the large size of these cytoplasmic lipid droplets (5–15 μm in diameter). Lipid droplets are directionally trafficked within the epithelial cell to the apical plasma membrane. Upon contact, a molecular docking complex assembles to tether the droplet to the plasma membrane and facilitate its membrane envelopment. This docking complex consists of the transmembrane protein, butyrophilin, the cytoplasmic housekeeping protein, xanthine dehydrogenase/oxidoreductase, the lipid droplet coat proteins, PLIN2, and cell death-inducing DFFA-like effector A. Interactions of mitochondria, Golgi, and secretory vesicles with docked lipid droplets have also been reported and may supply membrane phospholipids, energy, or scaffold cytoskeleton for apocrine secretion of the lipid droplet. Final secretion of lipid droplets into the milk occurs in response to oxytocin-stimulated contraction of myoepithelial cells that surround milk-secreting epithelial cells. The mechanistic details of lipid droplet release are unknown at this time. The final secreted milk fat globule consists of a triglyceride core coated with a phospholipid monolayer and various coat proteins, fully encased in a membrane bilayer

Organellar Contacts of Milk Lipid Droplets

Milk-secreting epithelial cells of the mammary gland are functionally specialized for the synthesis and secretion of large quantities of neutral lipids, a major macronutrient in milk from most mammals. Milk lipid synthesis and secretion are hormonally regulated and secretion occurs by a unique apocrine mechanism. Neutral lipids are synthesized and packaged into perilipin-2 (PLIN2) coated cytoplasmic lipid droplets within specialized cisternal domains of rough endoplasmic reticulum (ER). Continued lipid synthesis by ER membrane enzymes and lipid droplet fusion contribute to the large size of these cytoplasmic lipid droplets (5–15 μm in diameter). Lipid droplets are directionally trafficked within the epithelial cell to the apical plasma membrane. Upon contact, a molecular docking complex assembles to tether the droplet to the plasma membrane and facilitate its membrane envelopment. This docking complex consists of the transmembrane protein, butyrophilin, the cytoplasmic housekeeping protein, xanthine dehydrogenase/oxidoreductase, the lipid droplet coat proteins, PLIN2, and cell death-inducing DFFA-like effector A. Interactions of mitochondria, Golgi, and secretory vesicles with docked lipid droplets have also been reported and may supply membrane phospholipids, energy, or scaffold cytoskeleton for apocrine secretion of the lipid droplet. Final secretion of lipid droplets into the milk occurs in response to oxytocin-stimulated contraction of myoepithelial cells that surround milk-secreting epithelial cells. The mechanistic details of lipid droplet release are unknown at this time. The final secreted milk fat globule consists of a triglyceride core coated with a phospholipid monolayer and various coat proteins, fully encased in a membrane bilayer

Encouraging Feedback In The Large College Class: The Use Of A Question/Comment Box

This article examines the use of a question/comment box in a large course, as a communication strategy to enhance student participation and involvement in the said courses. Specifically, the categories into which questions and comments were coded are reported, and examples of actual messages received are included. In addition, the results of a questionnaire that assessed student perceptions of involvement, instructor quality, course quality, and learning as a result of the question/comment box are reported for male and female lower-division and upper-division students

The separation of red blood cells based solely on intrinsic magnetization: Clinical and commercial implications

A rough estimate puts the cell isolation market at approximately $ 6 billion a year worldwide. One of the key commercial technologies uses antibodies conjugated to magnetic micro and nanoparticles (i.e Dynal beads or Miltenyi MACS systems). While clearly effective, whenever antibodies are used, whether conjugated to magnetic particles, or fluorescent molecules (such as used in FACS systems), there is always the issue of the sensitivity and specificity of the antibody for the targeted cell(s). This “issue”, amongst others, is the motivator for “label free” identification and separation technology. Removal of human red blood cells, hRBCs, from a blood or bone marrow sample for diagnostic, or therapeutic applications is a fundamental laboratory practice/procedure. While difficult to obtain precise numbers, it has been suggested that greater than a billion blood draws are conducted in the US each year. While for a majority of these blood draws an evaluation of the RBCs is an important part, there is still a very large number of tests that focus on the remaining blood components after the RBCs have been removed. While not nearly as common as a blood draw, more than 18,000 bone marrow or umbilical cord blood transplants were performed in the US in 2013. In the case of bone marrow transplants, the RBCs need to be removed prior to transfusion or cryopreservation, regardless of whether the donor and patient’s tissues match. Viewed from a mechanistic perspective, there are three primary methodologies to remove human RBCs, hRBCs, from a blood draw: 1) RBC lysis, 2) immunological based separation in which a RBC is bound with an affinity ligand which facilitates RBC removal, or 3) separation of the RBC from the nucleated cells based on density differences. The two most commonly used methods are the density difference methods with or without hydrophilic polysaccharide addition (e.g Ficoll density gradient based centrifugation, DGC,). When blood samples are only used for further analysis, the condition and the content of the sample after the RBC removal is only important with respect to how it affects the subsequent analysis; however, when the RBC depleted sample is destined for transfusion into a patient, significantly higher standards are required. We previously compared RBC removal using the Ficoll-based DGC to lysis protocols. Using either method would remove more than 99% of RBCs; however the average recovery of the spiked cancer cells was 73 and 89% for the Ficoll and RBC lysis, respectively. Poor recovery of targeted cells, such as hematopoietic stem cells, in the initial RBC depletion step is a problem in the bone marrow transplant/regenerative medicine community. In fact, several reports indicate that the recovery of nucleated cells from bone marrow, BMNCs, using Ficoll-based DGC, can be as low as 15-30%. Complementary to these reports, two recent papers suggest that cells with high regenerative potential, such as very small embryonic-like stem cells, VSELs and mesenchymal stromal cells are depleted with DGC. Finally, there are suggestions that Ficoll DGC can impair receptor function of the recovered cells. It is well established that deoxygenated RBCs are weakly paramagnetic; initially reported by Linus Pauling and coworkers in 1936. Melville and co-workers demonstrated in the mid 1970’s that RBCs can be captured using a ferromagnetic wire mesh when the cells are reduced (chemical turned into a state equivalent to the deoxy-state). More recently, we have demonstrated that RBCs can be captured in HGMS systems (i.e. Miltenyi Biotec MACS columns), magnetically deposited on slides, deposited on the wall of a channel, and continuous removed using a flow through separation system. While these studies demonstrate theoretically, and experimentally, that it is possible to separate RBCs based on intrinsic magnetization, the throughputs in these studies are orders of magnitude lower than needed to practically remove RBCs from a typical blood draw. In this presentation we will present our latest systems which we suggest can increase the throughputs by orders of magnitude which presents the potential for magnetic separation of RBCs to become a practical alternative to the currently used approaches

Quantifying alignment in carbon nanotube yarns and similar two‐dimensional anisotropic systems

The uniaxial orientational order in a macromolecular system is usually specified using the Hermans factor which is equivalent to the second moment of the system\u27s orientation distribution function (ODF) expanded in terms of Legendre polynomials. In this work, we show that for aligned materials that are two‐dimensional (2D) or have a measurable 2D intensity distribution, such as carbon nanotube (CNT) textiles, the Hermans factor is not appropriate. The ODF must be expanded in terms of Chebyshev polynomials and therefore, its second moment is a better measure of orientation in 2D. We also demonstrate that both orientation parameters (Hermans in three dimensional (3D) and Chebyshev in 2D) depend not only on the respective full‐width‐at‐half‐maximum of the peaks in the ODF but also on the shape of the fitted functions. Most importantly, we demonstrate a method to rapidly estimate the Chebyshev orientation parameter from a sample\u27s 2D Fourier power spectrum, using an analysis program written in Python which is available for open access. As validation examples, we use digital photographs of dry spaghetti as well as scanning electron microscopy images of direct‐spun carbon nanotube fibers, proving the technique\u27s applicability to a wide variety of fibers and images

Enumeration and Identification of Selected Bacteria in Water Samples from the Alapahoochee River System

Escherichia coli and enterococci were enumerated in water collected biweekly for one year at ten stations in the Alapahoochee River system. The concentrations of E.coli were usually below a standard of 576 colony forming units (cfu) per 100 ml, except after heavy rain. At five stations the concentrations of enterococci were gener­ally above a standard of 151 cfu/100 ml. Concentrations of both groups showed a direct but weak correlation with pH. For quality control, 772 colonies typical of E. coli and 773 colonies typical of enterococcus were tested by the appropriate verification procedures. Sixty-six (8.5%) of the former, and 57 (7.4%) of the latter, appeared to be false positives. Further study of 51 apparent false positive E. coli isolates showed that only 15.7% did not contain E.coli, indicating an actual false positive rate of about 1.3%. Further study of 18 false positive enterococcus isolates showed that 16.7% were Enterococ­cus species and 83.3% were Streptococcus species. Thus the actual false positive rate was estimated to be 6.2 %

The Development of a New Scale to Measure Food Insecurity Among Older Adults Using the International Classification of Functioning, Disability, and Health (ICF) Framework

Background: Older adults face different barriers to accessing adequate food, and none of the current food security scales address the unique issues that aging could present to food security among this population. Purpose: This study aims to understand the components of nutrition functioning in relation to food insecurity among older adults to develop a food insecurity screening tool specific to the older adult population. Methods: Cross-sectional qualitative study with semi-structured interviews. The interviews occurred via Google Voice and were simultaneously recorded using Zoom. Two researchers coded transcriptions from interview audio recordings separately, and thematic analysis based on the International Classification of Functioning, Disability, and Health (ICF) was used to analyze the data. The findings were deliberated between all the researchers, and the final themes, subthemes, and representative quotes were mutually agreed upon. Results: Twenty-three older adults living in independent senior living facilities were interviewed. Nine themes (transportation, access/variety, housing, mobility & aging, preparing food, interpersonal relationship, food assistance, dentition/ingestion/digestion, health conditions) and twenty-two subthemes were identified. The results demonstrated that lack of transportation, interpersonal relationships, health-related conditions, and financial constraints were this population\u27s principal barriers to accessing and preparing adequate food. Discussion: Food insecurity among older adults is a multi-dimension issue. A new scale to measure food insecurity among older adults was created to provide a more accurate assessment of food security risk in this population. Future research should validate this scale in different settings

Teaching and Learning Qualitative Inquiry Online and Impacts on Family Life

This study uses letters-to-self and a group interview to integrate the experiences of two groups of participant-researchers—(1) a professor of qualitative inquiry and two of his doctoral students in an online qualitative research class and (2) this same professor and his family. The specific purpose of this study for the first group, comprised of the professor and his two former doctoral students, was to jointly explore perceptions of teaching and learning qualitative inquiry in a formal university setting as well as these students’ perceptions of the impacts that their entry into full-time doctoral study has had on their family life. The specific purpose for the second group, comprised of the professor and his family, was to jointly explore perceptions of teaching and learning qualitative inquiry in a family setting. It was found that a richer understanding of the dynamics of teaching and learning qualitative inquiry amidst the dynamics of family life emerged from this study and will hopefully lead to further explorations of this complex phenomena among professors, students, and families

Bilateral Distal Radius Fractures in a 12-Year-Old Boy after Household Electrical Shock: Case Report and Literature Summary

Background. Fracture resulting from household electric shock is uncommon. When it occurs, it is usually the result of a fall; however, electricity itself can cause sufficient tetany to produce a fracture. We present the case of bilateral fractures of the distal radii of a 12-year-old boy which were sustained after accidental shock. The literature regarding fractures after domestic electric shock is also reviewed. Methods. An Ovid-Medline search was conducted. The resultant articles and their bibliographies were surveyed for cases describing fractures resulting from a typical household-level voltage (110–220 V, 50–60 Hertz) and not a fall after the shock. Twenty-one articles describing 22 patients were identified. Results. Twenty-two cases were identified. Thirteen were unilateral injuries; 9 were bilateral. Proximal humerus fractures were most frequent (8 cases), followed by scapula fractures (7 cases), forearm fractures (4 cases), femoral neck fractures (2 cases), and vertebral body fracture (1 case). Eight of the 22 cases were diagnosed days to weeks after the injury. Conclusions. Fracture after electric shock is uncommon. It should be suspected in patients with persistent pain, particularly in the shoulder or forearm area. Distal radius fractures that occur during electrocution are likely due to tetany

Phencyclidine Disrupts the Auditory Steady State Response in Rats

The Auditory Steady-State Response (ASSR) in the electroencephalogram (EEG) is usually reduced in schizophrenia (SZ), particularly to 40 Hz stimulation. The gamma frequency ASSR deficit has been attributed to N-methyl-D-aspartate receptor (NMDAR) hypofunction. We tested whether the NMDAR antagonist, phencyclidine (PCP), produced similar ASSR deficits in rats. EEG was recorded from awake rats via intracranial electrodes overlaying the auditory cortex and at the vertex of the skull. ASSRs to click trains were recorded at 10, 20, 30, 40, 50, and 55 Hz and measured by ASSR Mean Power (MP) and Phase Locking Factor (PLF). In Experiment 1, the effect of different subcutaneous doses of PCP (1.0, 2.5 and 4.0 mg/kg) on the ASSR in 12 rats was assessed. In Experiment 2, ASSRs were compared in PCP treated rats and control rats at baseline, after acute injection (5 mg/kg), following two weeks of subchronic, continuous administration (5 mg/kg/day), and one week after drug cessation. Acute administration of PCP increased PLF and MP at frequencies of stimulation below 50 Hz, and decreased responses at higher frequencies at the auditory cortex site. Acute administration had a less pronounced effect at the vertex site, with a reduction of either PLF or MP observed at frequencies above 20 Hz. Acute effects increased in magnitude with higher doses of PCP. Consistent effects were not observed after subchronic PCP administration. These data indicate that acute administration of PCP, a NMDAR antagonist, produces an increase in ASSR synchrony and power at low frequencies of stimulation and a reduction of high frequency (> 40 Hz) ASSR activity in rats. Subchronic, continuous administration of PCP, on the other hand, has little impact on ASSRs. Thus, while ASSRs are highly sensitive to NMDAR antagonists, their translational utility as a cross-species biomarker for NMDAR hypofunction in SZ and other disorders may be dependent on dose and schedule