Influence of cyclonic and anti-cyclonic eddies on plankton biomass, activity and diversity in the southeastern Mediterranean Sea

Planktonic food-webs were studied contemporaneously in a mesoscale cyclonic (upwelling, ~13 months old) and an anti-cyclonic (down-welling, ~2 months old) eddies, as well as in an uninfluenced-background situation in the oligotrophic southeastern Mediterranean Sea (SEMS) during late summer 2018. We show that integrated nutrients concentrations were higher at the cyclone compared to the anti-cyclone or the background stations by 2–13 fold. Concurrently, Synechococcus and Prochlorococcus were the dominant community component abundance-wise in the oligotrophic anti-cyclone (~300 × 1010 cells m−2). In the cyclone, pico- and nanoeukaryotes such as dinoflagellates, Prymnesiophyceae and Ochrophyta contributed substantially to the total phytoplankton abundnce (~14 × 1010 cells m−2) which was ~65 % lower in the anti-cyclone/background stations (~5 × 1010 cells m−2). Primary production was highest in the cyclonic eddy (191 mg C m−2 d−1) and was 2–5 fold lower outside the eddy area. The calculated doubling time of phytoplankton was ~3 days in the cyclone and ~5–10 days at the anti-cyclone/background stations, further reflecting the nutritional differences between these environments. Heterotrophic prokaryotic cell-specific activity was highest in the cyclone (~10 fg C cell−1 d−1), while the least productive cells were found in the anti-cyclone (4 fg C cell−1 d−1). The calculated doubling time of heterotrophic bacteria were 1.4 days in the cyclone and 2.5–3.5 days at the anti-cyclone/background stations. Total zooplankton biomass in the upper 300 m was tenfold higher in the cyclone compared with the anti-cyclone or background stations (1337 vs. 112–133 mg C m−2, respectively). Copepod diversity was much higher in the cyclone (44 species), compared to the anti-cyclone (6 small-size species). Our results highlight that cyclonic and anti-cyclonic eddies show significantly different community compositions and food-web dynamics in oligotrophic environments, with cyclones representing productive oases in the marine desert of the SEMS.

Medullary Carcinoma of Thyroid Due to GLP-1 Receptor Agonist

Introduction: The first GLP-1 receptor agonist (GLP-1 RA) was approved for the treatment of type 2 Diabetes mellitus in 2005. This class has gained popularity due to its anti-glycemic effect, weight loss and reduction in Cardiovascular disease outcomes1. The effects of this drug class on human thyroid cells are not well known. We hereby report a case of a woman who developed medullary carcinoma of thyroid (MTC) after using Dulaglutide. CaseA 63-year-old female with T2DM for 3 years, taking dulaglutide for 2 years, who presented with a lump in the neck. She had no personal or family history of MEN 2 syndrome, radiation exposure or cancer. Examination showed a 2cm firm nodule in the left lower neck. Thyroid ultrasound revealed a large nodule in the left upper lobe of thyroid. Lab work showed TSH of 1.55mIU/L (0.27-4.2 mIU/L) and serum calcitonin level of 1903 pg/ml (0.0-5.1 pg/mL). FNA biopsy of the nodule showed MTC. She tested negative for RET MEN 2 gene mutation. She underwent total thyroidectomy and neck dissection. Pathological examination confirmed MTC. Post-op calcitonin improved to 2.1 pg/ml. Discussion: GLP-1 RAs provide glycemic control by many mechanisms, including increase in insulin secretion, reduction in postprandial glucagon secretion, delaying gastric emptying, increasing satiety and weight loss. Although they have proved effective in T2DM management, the potential effects on thyroid C-cells should not be ignored. Several in-vitro studies have shown GLP-1 receptors on the rat thyroid tissue C-cells. Stimulation of these receptors resulted in increased production of calcitonin in a dose dependent manner and increased risk of C-cell tumor formation at 104 weeks. Studies initially done by Knudsen et al2 showed that this effect was not seen in humans due to lower expression of GLP-1 receptors in human thyroid tissue C cells. However, a study conducted by Gier et al showed the expression of GLP-1 receptor in some patients with C-cell hyperplasia as well as papillary and medullary carcinoma3. FDA adverse event reporting system database suggested an increased risk of thyroid cancer associated with GLP-1 RAs. It is unclear whether dulaglutide contributed to the development of MTC in this patient. She had not had a baseline calcitonin level prior to the initiation of dulaglutide. The consequence of long-term use of GLP-1 RAs in the thyroid gland in humans still remains unknown and further studies to determine if they increase the risk of MTC are warranted. References: 1. Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes. N Engl J Med. 2016;375(4):311. Epub 2016 Jun 13. 2. Glucagon-like Peptide-1 receptor agonists activate rodent thyroid C-cells causing calcitonin release and C-cell proliferation. Endocrinology. 2010;151(4):1473. Epub 2010 Mar 3. Glucagon Like Peptide-1 Receptor Expression in the Human Thyroid Gland

Diagnostic Utility of INSM1 in Medullary Thyroid Carcinoma

Insulinoma-associated protein 1 (INSM1) is shown to be an excellent marker for neuroendocrine differentiation. However, the diagnostic utility of INSM1 in medullary thyroid carcinoma (MTC) has not yet been extensively investigated. INSM1 staining was performed on 21 MTCs, 7 MTC mimickers (including 3 papillary carcinomas, 2 poorly differentiated carcinomas, 1 follicular adenoma, and 1 nodular plasma cell hyperplasia), and 3 cases of C-cell hyperplasia. INSM1 staining of these cases was compared with the traditional MTC markers including calcitonin (CT), monoclonal carcinoembryonic antigen (mCEA), chromogranin A (CgA), and synaptophysin (Syn). The H-score was generated using the QuPath program, an open-source image analysis software. All 21 MTC cases and 3 C-cell hyperplasia cases were positive for all markers. The MTC mimickers were entirely negative for INSM1. INSM1 and Syn displayed, more consistently, high expression with minimal variability than CgA that showed a wide range of expression with significant variability. mCEA and CT exhibited mostly a high expression with some variability. Being a nuclear stain, interpretation was easier with INSM1 compared to other cytoplasmic markers. INSM1 is an excellent marker for neuroendocrine differentiation, entirely applicable in the diagnosis of MTC and C-cell hyperplasia with high sensitivity and specificity. In comparison with the traditional MTC markers, INSM1 is unique in the crisp nuclear staining pattern with a consistent, diffuse, and strong expression. INSM1 can be potentially combined with CT or mCEA as a dual stain, especially when the lesional tissue is limited for a panel of immunostains.

Quality control of direct cell–mineral adhesion measurements in air and liquid using inverse AFM imaging

Setup for a reliable cell-mineral interaction at the single-cell level, (a) study of the mineral by a sharp tip, (b) study of the bacterial modified probe by a characterizer, (c) cell-mineral interaction, (d) subsequent check of the modified probe.