CTLA-4: From mechanism to autoimmune therapy

CD28 and CTLA-4 are both important stimulatory receptors for the regulation of T cell activation. Because receptors share common ligands, B7.1 and B7.2, the expression and biological function of CTLA-4 is important for the negative regulation of T cell responses. Therefore, elimination of CTLA-4 can result in the breakdown of immune tolerance and the development of several diseases such as autoimmunity. Inhibitory signals of CTLA-4 suppress T cell responses and protect against autoimmune diseases in many ways. In this review, we summarize the structure, expression and signaling pathway of CTLA-4. We also highlight how CTLA-4 defends against potentially self-reactive T cells. Finally, we discuss how the CTLA-4 regulates a number of autoimmune diseases that indicate manipulation of this inhibitory molecule is a promise as a strategy for the immunotherapy of autoimmune diseases.

EVALUATING SHORT-TERM EXPOSURE TO WI-FI SIGNALS ON STUDENTS' REACTION TIME, SHORT-TERM MEMORY AND REASONING ABILITY

This study investigated the effect of short-term exposure to Wi-Fi signals on the cognitive functions of the mind. After obtaining permission from the local Ethics Committee of Shiraz University of Medical Sciences and approval by the Iranian Registry of Clinical Trials (IRCT2017041233398N1), 45 male and female students from Shiraz University of Medical Sciences volunteered to participate in this study. They were exposed to Wi-Fi signals in two sham and exposure sessions, each for 2 hours. After completion, they took part in reaction time, short-term memory, and reasoning ability tests. After scoring, the data were analysed by SPSS software. In addition, the electric field strength and power density were calculated. The results showed no statistically significant differences between the mean scores of reaction time, short-term memory, and reasoning ability in sham and exposure. Also, the obtained values from the electric field strength and power density (E = 4.1 Vm-1, P = 0.446 Wm-2) were lower than that of threshold values by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Our results can greatly reduce concerns regarding the effects of short-term exposure to Wi-Fi waves on cognitive functions.

Cloning and Expression of Mannheimia haemolytica PlpE Gene in Escherichia coli and its Immunogenicity Assessment

Mannheimia haemolytica is responsible for considerable economic losses to cattle, sheep, and goat industries in many parts of the world. This bacterium isone of the causative agents of shipping fever in cattle. Current vaccines against M. haemolytica are moderately efficacious since they do not provide complete protection against the disease. Production of an economic vaccine for protecting farm animals against M. haemolytica has attracted the attention of many scientists. The outer membrane proteins (OMPs) play a major role in the pathogenesis and immunogenicity of M. haemolytica. Research on M. haemolytica OMPs has shown that antibodies to a particular OMP may be important in immune protection. In the current study, the gene for M. haemolytica OMP PlpE was cloned into the expression vector pET26-b, and then expressed in Escherichia coli BL21. The expression of the protein was carried out by the induction of cultured Escherichiacoli Bl21 cells with 1mM isopropyl-β-D-thiogalactopyranoside. The recombinant PlpE was purified using Ni-NTA agarose resin, and then subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis. The identity of the expressed protein was analyzed by western blotting. It was revealed that rPlpE was expressed and produced properly. To assess the immunogenicity of the recombinant protein, the purified rPlpE was used as an antigen for antibody production in goats. The observations suggested that the produced recombinant protein can be used as a antigen for developing diagnostic tests and or as a vaccine candidate.

Abstract P4-11-01: A simple intervention for long-term relief of chronic post mastectomy pain

Background: Post-mastectomy pain syndrome (PMPS) is a common and often debilitating condition. One common cause likely results from injury to the T4 and T5 sensory nerves during breast surgery, with resulting neuroma formation. It manifests as a pain syndrome diagnosed by “trigger points” that reproduce exquisite pain upon palpation. Pain specialists have found a combination of corticosteroids and local anaesthetic given through perineural infiltration, at other sites, effective in alleviating these neuromas or trigger points. Utilizing this principle, we initiated a quality improvement project to treat PMPS. This perineural injection led to remarkable, long-lasting relief of the first few patients, we therefore continued treating patients with clinical symptoms suggestive of a neuroma. We report on long-term pain relief after trigger point injections (TPI) for women with PMPS.

Methods: An observational cohort study of women with PMPS and clinical evidence of neuroma was undertaken. Patients were examined by breast surgeons at a single institution. We injected a 2mL mixture of equal parts 0.5% bupivacaine and 4 mg/mL dexamethasone into each trigger point. Demographics, type of breast and axillary surgery, duration of pain, history of surgical complications, adjuvant radiotherapy, number of injections required, location of trigger points and dates of injection were obtained from the electronic medical record. Patients were surveyed via telephone interview for long-term resolution of pain. Descriptive statistics are reported, univariate and bivariate analyses were conducted using Stata 12 (College Station, TX).

Results: We identified 89 trigger points on 61 breasts in 53 patients with PMPS. Patient age ranged from 30-92 years. Mean number of surgeries prior to injection was 2.2 (range 1-8). In this cohort, we found mastectomy was the most frequent surgical procedure preceding the development of a neuroma (41 breasts), followed by reduction mammoplasty with or without concurrent partial mastectomy (16 breasts), and least frequently lumpectomy alone (4 breasts). The time from the onset of neuropathic pain to the first trigger point injection varied from as early as 1 week post-operatively to 132 months (mean 22.2 months). Effectiveness of the TPI was assessed by physical examination immediately (1-3 minutes) after the injection, then with telephone interview (at >/=3 months post TPI). All 53 patients had long-term follow-up data (≥3 months). Long-term relief was achieved in 84 of 89 trigger points (94.4%) or 54 of 61 breasts (88.5%). Trigger point injections were well tolerated by all patients and no complications were reported.

Discussion: Perineural infiltration with bupivacaine and dexamethasone is a safe, simple, and effective treatment option for PMPS with an associated trigger point. Our data suggest this significant problem can easily be resolved in an outpatient setting. All breast specialists should inquire about the presence of symptoms consistent with PMPS and understand the value of intervention to eliminate neuropathic pain. This technique should be added to the armamentarium of all surgeons who perform breast surgery.

Citation Format: Keane HJ, Khoury AL, Hosseini A, Varghese FP, Mukhtar R, Eder SE, Wong J, Esserman LJ. A simple intervention for long-term relief of chronic post mastectomy pain [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-11-01.

Logarithmic Upturn in Low-Temperature Electronic Transport as a Signature of d-Wave Order in Cuprate Superconductors

In cuprate superconductors, high magnetic fields have been used extensively to suppress superconductivity and expose the underlying normal state. Early measurements revealed insulatinglike behavior in underdoped material versus temperature T, in which resistivity increases on cooling with a puzzling log(1/T) form. We instead use microwave measurements of flux-flow resistivity in YBa_{2}Cu_{3}O_{6+y} and Tl_{2}Ba_{2}CuO_{6+δ} to study charge transport deep inside the superconducting phase, in the low-temperature and low-field regime. Here, the transition from metallic low-temperature resistivity (dρ/dT>0) to a log(1/T) upturn persists throughout the superconducting doping range, including a regime at high carrier dopings in which the field-revealed normal-state resistivity is Fermi-liquid-like. The log(1/T) form is thus likely a signature of d-wave superconducting order, and the field-revealed normal state's log(1/T) resistivity may indicate the free-flux-flow regime of a phase-disordered d-wave superconductor.

Dietary energy level affects adipose depot mass but does not impair in vitro subcutaneous adipose tissue response to short-term insulin and tumor necrosis factor-α challenge in nonlactating, nonpregnant Holstein cows

We assessed effects of overfeeding energy to nonlactating and nonpregnant Holstein cows during a length of time similar to a typical dry period on body lipid storage and the abundance of genes related to insulin signaling, inflammation, and ubiquitination in subcutaneous adipose tissue (SAT) in vitro challenged with insulin and recombinant bovine tumor necrosis factor-α. Fourteen cows were randomly assigned to either a high-energy (OVE; net energy for lactation = 1.60 Mcal/kg of dry matter; n = 7) or control (CON; net energy for lactation = 1.30 Mcal/kg of dry matter; n = 7) diet for 6 wk. Immediately after slaughter, liver, kidneys, and mammary gland were separated and weighed. The adipose tissue mass in the omental, mesenteric, and perirenal depots was dissected and weighed. Subcutaneous adipose tissue was collected from the tail-head region and was used as follows: control, bovine insulin (INS) at 1 µmol/L, tumor necrosis factor-α at 5 ng/mL (TNF), and their combination. Despite a lack of difference in final body condition score, OVE cows had greater energy intake and were heavier than CON cows. Furthermore, overfeeding led to greater mass of mesenteric and perirenal adipose, liver, and mammary gland. Overall, SAT incubated with INS had an upregulation of insulin receptor (INSR), interleukin-10 (IL10), small ubiquitin-like modifier 3 (SUMO3), and ubiquitin conjugating enzyme E2I (UBC9), whereas TNF upregulated peroxisome proliferator-activated receptor gamma (PPARG), diacylglycerol O-acyltransferase 2 (DGAT2), interleukin-6 (IL6), nuclear factor kappa B subunit 1 (NFKB1), small ubiquitin-like modifier 2 (SUMO2), and UBC9. Regardless of in vitro treatment, feeding OVE upregulated PPARG, fatty acid synthase (FASN), and insulin induced gene 1 (INSIG1). Abundance of PPARG was greater in SAT of OVE cows cultured individually with INS and TNF. The interaction between diet and in vitro treatment revealed that sterol regulatory element binding transcription factor 1 (SREBF1) had greater abundance in SAT from the CON group in response to culture with INS, whereas SAT from OVE cows had greater SREBF1 abundance in response to culture with TNF. The mRNA abundance of IL6 and NFKB1 was greater in response to TNF treatment and overall in CON cows. Furthermore, SAT from these cows had greater IL10 abundance when cultured with INS and TNF. Overall, data highlighted that overfeeding energy increases adipose tissue mass in part by stimulating transcription of key genes associated with insulin signaling, adipogenesis, and lipogenesis. Because SAT thickness or mass was not measured, the lack of effect of overfeeding on body condition score limits its use to predict overall body lipid storage. An overt inflammatory response in SAT after a 6-wk period of over-consumption of energy could not be discerned.

Lactation-related changes in tissue expression of PEDF in dairy cows

Pigment epithelium-derived factor (PEDF) is evolving as metabolic regulatory protein. Albeit mostly considered in only pathological conditions related to excess energy intake resulting in obesity and insulin resistance, PEDF is likely to be involved in other physiological processes such as the homeorhetic adaptation of metabolism to lactation. We aimed to characterize the expression of PEDF and its association to the concomitant mobilization of body reserves during lactation in nonobese subjects. This mobilization is particularly distinct in dairy cows, and we therefore assessed the mRNA expression of PEDF and its putative receptors in different tissues in 2 trials with dairy cows fed with or without conjugated linoleic acids (CLAs). Conjugated linoleic acids depress milk fat synthesis and may thus reduce the drain of energy via milk. In pluriparous cows, the serum PEDF concentrations and the mRNA abundance in subcutaneous adipose tissue (scAT), as well as the hepatic and scAT mRNA abundance of the putative receptors, adipose triglyceride lipase, and laminin receptor 1, changed over time of sampling (day -21 until day 252 relative to calving). Conjugated linoleic acid treatment was associated with reduced PEDF concentrations in serum and lower PEDF mRNA abundance in scAT on day 21 postpartum. Comparing different tissues from primiparous cows, PEDF mRNA was highest in the liver, followed by scAT, visceral adipose tissue (AT), and mammary gland, and lowest in the muscle. Significant changes in PEDF expression with time of sampling were limited to AT in primiparous and pluriparous cows. Our data support a regulatory role for PEDF. The similarities between the time course of the serum concentrations of PEDF and its mRNA abundance in scAT may point to a regulatory role for AT rather than the liver for PEDF in dairy cows.

Treatment of third-degree burn wounds in animal specimens: acellular dermis or partial-thickness skin graft

Several dermal products have been introduced to substitute dermal tissues. In this study we review the effects of these products on repairing third-degree burn wounds and managing complications in animal specimens. Using an interventional approach, rats were randomly assigned to four groups (G1 to G4). Two wounds were created on the back of each rat. An open wound was left on the back of rats in G1; in G2, wounds were covered with a thick rat derived-ADM product and overlying thin skin graft; on G3 rats, similar third degree ulcers were made with one ulcer covered with harvested thin skin graft. In G4, ulcers were covered with a thin rat derived-ADM product and thin graft. Factors such as take rate, histopathological score, wound contracture and graft contracture were compared on the 7th, 15th, 21st and 30th day. Mean graft take rate on the 30th day in the thick ADM, thin ADM and graft group showed a significant difference (p=0.015). Histopathological score on the 30th day in the thin ADM, thick ADM and graft group showed no considerable difference. Mean graft take rate was significantly better in the thin ADM and graft group than in the thick ADM group. Wound contracture was significantly more severe in the thick ADM and control group than in the thin ADM and graft group.

Abstract P5-22-22: Breast tumor location in BRCA mutation carriers and implications for prevention

Introduction:

Close to 65% of BRCA mutation carriers do not choose prophylactic mastectomy, despite their high breast cancer risk. Breast reduction mammoplasty is a surgical technique shown to reduce breast cancer risk and can be modified to target specific areas of the breast. We wondered if a majority of tumors in BRCA mutation carriers would be confined to one quadrant, allowing for the use of targeted cosmetic mammoplasty as a novel method of risk reduction.

Methods:

We reviewed imaging reports on 103 consecutive patients with BRCA mutations and invasive breast cancer, and categorized tumor location by quadrant. Tumors spanning >1 quadrant were classified as being in both. Bilateral cancers were counted separately. Categorical variables were compared with the chi-squaredtest.

Results:

Mean age at breast cancer diagnosis was 44 years with mean tumor size of 2.2 cm (0.1-7cm). 92% of tumors were invasive ductal carcinoma, 46% were hormone receptor positive, 10% Her2 positive, and 44% triple negative. 70% of the tumors were unicentric. Tumors were significantly more likely to be in the upper outer quadrant whether or not multicentric tumors were included in the analysis (p<0.00001). Her2 positive tumors were more likely to be multicentric than other subtypes (p=0.021).

Conclusions:

More than half of breast cancers in BRCA mutation carriers form in the upper outer quadrant, suggesting that removing this quadrant through breast reduction mammoplasty could significantly reduce breast cancer risk. For women who are not ready for prophylactic mastectomy, this data supports an intermediate risk reduction step instead of only offering surveillance.

Citation Format: Hosseini A, Esserman LJ, Wallace AM, Au A, Mukhtar RA. Breast tumor location in BRCA mutation carriers and implications for prevention [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-22-22.

Abstract P5-12-04: The impact of bariatric surgery on mammographic breast density

Background:

Bariatric surgery decreases breast cancer risk, but its impact on mammographic findings is not well understood. Obesity and breast density both increase breast cancer risk, but paradoxically are inversely related. We investigated how mammographic density changes after bariatric surgery, and whether or not that change is related to amount of weight loss.

Methods:

We reviewed records for 349 prospectively collected patients who underwent bariatric surgery between 2013-2015, and identified 45 women with pre- and post-operative screening mammograms within 1.5 years of surgery. We recorded body mass index (BMI), Breast Imaging-Reporting and Data System density, and calculated excess BMI loss. Data were analyzed in Stata 14.2.

Results:

Average age was 54 years, mean pre-operative BMI was 44 (range 36-72), and mean percentage excess BMI lost was 73% at 1.3 years. One third had a change in mammographic breast density, which increased 93% of the time (p<0.001). Amount of weight loss was not associated with density change; in fact, weight loss was lower in those with a density change than in those without a density change (68% versus 75% excess BMI lost).

Conclusions:

The majority of women with a mammographic change had an increase in breast density, despite bariatric surgery being associated with reduced breast cancer risk. Interestingly, the amount of weight loss was not associated with change in breast density. These findings suggest the metabolic effects of bariatric surgery have an effect on breast cancer risk independent of BMI reduction. Future work will include studying mammographic changes associated with non-surgical weight loss.

Citation Format: Hosseini A, Khoury AL, Carter J, Wong JM, Alvarado MD, Ewing C, Esserman LJ, Mukhtar RA. The impact of bariatric surgery on mammographic breast density [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-12-04.

Effect of time of eCG administration on the fate of ovarian follicle in Holstein heifers

The objective of this study was to investigate the effect of equine chorionic gonadotropin (eCG) on ovarian follicles at three stages of development (emergence, dominance and early static phases) during the first follicular wave (FFW) in Holstein heifers. Heifers (n=20) were randomly assigned into four experimental groups (n=5 in each group). Heifers received eCG (500 IU; Folligon^®; Intervet, Holland; i.m) a) on the day of follicle emergence (day of ovulation; group 1), b) on the dominant phase (dominant follicle (DF): the first day in which follicle was observed at ≥10 mm; group 2, and c) on the early static phase (group 3) of the FFW. Control group heifers did not receive any treatment. Daily ultrasonography was conducted to monitor ovarian structure throughout estrous cycle. All treatment group heifers, regardless of the stage of follicle development, displayed follicle growth after eCG injection. Administration of eCG, in group 1, hastened DF detection and induced co-dominant follicles; whereas, in groups 2 and 3, it delayed DF regression, and increased cycle length compared to control. In all treatment group heifers, DF was present 84 h after eCG injection. Maximum diameter of corpus luteum was larger in eCG treated groups compared to control (P<0.05). In conclusion, depending on the time of eCG administration throughout the FFW (emergence, dominant and early static phases), co-dominancy, maintenance of DF, enhancement of follicle and corpus luteum growth and increase in estrous cycle length could be observed in Holstein heifers.

Enrichment of magnetic particles using temperature and magnetic field gradients induced by benchtop fabricated micro-electromagnets

The active transport of analytes inside biosensing systems is important for reducing the response time and enhancing the limit-of-detection of these systems. Due to the ease of functionalization with bio-recognition agents and manipulation with magnetic fields, magnetic particles are widely used for active and directed transport of biological analytes. On-chip active electromagnets are ideally suited for manipulating magnetic particles in an automated and miniaturized fashion inside biosensing systems. Unfortunately, the magnetic force exerted by these devices decays rapidly as we move away from the device edges, and increasing the generated force to the levels necessary for particle manipulation requires a parallel increase in the applied current and the resultant Joule heating. In this paper, we designed a study to understand the combined role of thermal and magnetic forces on the movement of magnetic particles in order to extend the interaction distance of on-chip magnetic devices beyond the device edges. For this purpose, we used a rapid prototyping method to create an active/passive on-chip electromagnet with a micro/nano-structured active layer and a patterned ferromagnetic passive layer. We demonstrated that the measured terminal velocities of particles positioned near the electromagnet edge (∼5.5 μm) closely reflect the values obtained by multi-physics modelling. Interestingly, we observed a two orders of magnitude deviation between the experimental and modelling results for the terminal velocities of particles far from the electromagnet edge (∼55.5 μm). Heat modelling of the system using experimentally-measured thermal gradients indicates that this discrepancy is related to the enhanced fluid movement caused by thermal forces. This study enables the rational design of thermo-magnetic systems for thermally driving and magnetically capturing particles that are positioned at distances tens to hundreds of microns away from the edges of on-chip magnetic devices.

Effects of Chlamydia trachomatis infection on sperm chromatin condensation and DNA integrity

The present study was performed to investigate the relation of Chlamydia trachomatis infection to sperm chromatin/DNA integrity in a population of infertile men (male partner of infertile couples) from Iran. Blood, semen and first-void urine samples were obtained from 250 infertile men. Data were analysed with regard to the results of (i) serological analysis for specific antibodies to C. trachomatis in serum; (ii) the presence of C. trachomatis and DNA in first-void urine; and (iii) in the semen sample of the male partner, in addition to sperm analysis, four different tests (aniline blue, chromomycin A3, acridine orange and TUNEL) were used to detect sperm chromatin and DNA abnormalities. The main conclusions of the results were: (i) no evidence of C. trachomatis infection in semen samples was found; (ii) sperm DNA fragmentation and chromatin studies were not correlated with C. trachomatis diagnosis; (iii) the percentage of DNA fragmentation is positively correlated with the percentage of immotile sperm but negatively with semen volume, normal morphology; and (iv) in sperm chromatin evaluations, only the percentage of chromatin protamination was related to male age.

Extended C-band tunable multi-channel InP-based coherent receiver PICs

Fully integrated monolithic, multi-channel InP-based coherent receiver PICs and transceiver modules with extended C-band tunability are described. These PICs operate at 33 and 44 Gbaud per channel under dual polarization (DP) 16-QAM modulation. Fourteen-channel monolithic InP receiver PICs show integration and data rate scaling capability to operate at 44 Gbaud under DP 16-QAM modulation for combined 4.9 Tb/s total capacity. Six channel simultaneous operation of a commercial transceiver module at 33 Gbaud is demonstrated for a variety of modulation formats including DP 16-QAM for >1.2Tbit/s aggregate data capacity.

Optimal ratios of essential amino acids stimulate β-casein synthesis via activation of the mammalian target of rapamycin signaling pathway in MAC-T cells and bovine mammary tissue explants

Amino acids are the building blocks of proteins and serve as key molecular components upstream of the signaling pathways that regulate protein synthesis. The objective of this study was to systematically investigate the effect of essential AA ratios on milk protein synthesis in vitro and to elucidate some of the underlying mechanisms. Triplicate cultures of MAC-T cells and bovine mammary tissue explants (MTE) were incubated with the optimal AA ratio (OPAA; Lys:Met, 2.9:1; Thr:Phe, 1.05:1; Lys:Thr, 1.8:1; Lys:His, 2.38:1; and Lys:Val, 1.23:1) in the presence of rapamycin (control), OPAA, a Lys:Thr ratio of 2.1:1, a Lys:Thr ratio of 1.3:1, a Lys:His ratio of 3.05:1, or a Lys:Val ratio of 1.62:1 for 12 h; the other AA concentrations were equal to OPAA. In some experiments, the cells were cultured with OPAA with or without rapamycin (100 ng/mL) or with mammalian target of rapamycin (mTOR) small interference RNA, and the MTE were exposed to OPAA with rapamycin for β-casein expression. Among the treatments, the expression of β-casein was greatest in the MTE cultured with OPAA. In MAC-T cells, the OPAA upregulated the mRNA expression of SLC1A5 and SLC7A5 but downregulated the expression of IRS1, AKT3, EEF1A1, and EEF2 compared with the control. The OPAA had no effect on the mTOR phosphorylation status but increased the phosphorylation of S6K1 and RPS6. When the MTE were treated with rapamycin in the presence of OPAA, the expression of β-casein was markedly decreased. The phosphorylation of RPS6 and 4EBP1 also was reduced in MAC-T cells. A similar negative effect on the expression of RPS6KB1 and EIF4EBP1 was detected when the cells were cultured with either rapamycin or mTOR small interference RNA. The optimal AA ratio stimulated β-casein expression partly by enhancing the transport of AA into the cells, cross-talk with insulin signaling and a subsequent enhancement of mTOR signaling, or translation elongation in both MAC-T cells and bovine MTE.