The prophylactic or curative antioxidant efficacy of crude extract and the active constituent of S. nigrum leaves were evaluated in modulating inherent antioxidant system altered due to immobilization stress in rat brain tissues, in terms of measurement of glutathione (GSH), lipid peroxidation (thiobarbituric acid reactive substances, TBARS), and free radical scavenging enzymes activities. Rats were treated with single dose of crude extract of S. nigrum prior to and after 6 h of immobilization stress exposure. Exposure to immobilization stress resulted in a decrease in the brain levels of glutathione, SOD, GST, and catalase, with an increase in thiobarbituric acid reactive substances (TBARS) levels. Treatment of S. nigrum extract and its active constituents to both pre‐ and poststressed rats resulted in significant modulation in the above mentioned parameters towards their control values with a relative dominance by the latter. Brain is vulnerable to stress induced prooxidant insult due to high levels of fat content. Thus, as a safe herbal medication the S. nigrum leaves extract or its isolated constituents can be used as nutritional supplement for scavenging free radicals generated in the brain due to physical or psychological stress or any neuronal diseases per se.

O1 Regulation of genes by telomere length over long distances

Alpha therapy (TAT) relies on combining alpha-emitting radionuclides with specific cell-targeting vectors to deliver a high payload of cytotoxic radiation capable of destroying tumor tissues. TAT efficacy comes from the tissue selectivity of the targeting vector, the high linear energy transfer (LET) of the radionuclide, and the short range of alpha particles in tissues. Recent research studies have been directed to evaluate TAT on a preclinical and clinical scale, including evaluating damage to tumor tissues with minimal toxic radiation effects on surrounding healthy tissues. This review highlights the use of Actinium-225/Bismuth-213 radionuclides as promising candidates for TAT. Herein, we begin with a discussion on the production and supply of [²²⁵Ac]Ac/[²¹³Bi]Bi followed by the formulation of [²²⁵Ac]Ac/[²¹³Bi]Bi-radiopharmaceuticals using different radiolabeling techniques. Finally, we have summarized the preclinical and clinical evaluation of these potential radiotheranostic agents.

Background: Familial hypocalciuric hypercalcemia (FHH) is a heterogeneous autosomal-dominant disorder of calcium hemostasis that may be difficult to distinguish clinically from mild primary hyperparathyroidism. Loss-of-function mutations mainly involving Arg15 residue of the adaptor-related protein complex 2, sigma subunit 1 (AP2S1) cause a rarer, more recently recognized form of FHH, FFH type-3. Recently, ¹⁸F-fluorocholine positron emission tomography/computed tomography (FCH-PET/CT) showed superior sensitivity to conventional imaging in localizing parathyroid adenomas. We report a new FFH type-3 patient who underwent unnecessary parathyroidectomy in association with misleading FCH-PET/CT imaging. Case presentation: A 29-year old woman was initially evaluated for parathyroid hormone (PTH)-dependent hypercalcemia in 2013. Medical history was positive only for chronic constipation and malaise with no personal or family history of hypercalcemia, kidney stones, or neck surgery. Over seven years, serum calcium level was 2.51–2.89 mmol/L with concomitant PTH level of 58.7–94.8 mmol/L. Serum phosphate levels were in the low/low normal range. Serum creatinine and magnesium levels were normal. 25-hydroxy vitamin D level was 13 nmol/L. 24-hour urine calcium level was 1.92 mmol/day but increased to 6.99 mmol/day after treatment with cholecalciferol 1000 IU daily. Bone mineral density and renal ultrasound were normal. Parathyroid ultrasound showed two hypoechoic nodules inferior to the left and right thyroid lobes; however, ^99mtechnitium-sestamibi scans (2013, 2016, 2018) were negative. FCH-PET/CT (2019) showed focal uptake co-localizing with the nodule inferior to the left thyroid lobe. The patient underwent left inferior parathyroidectomy and pathology was consistent with parathyroid hyperplasia. However, postoperatively, serum calcium and PTH levels remained elevated and FCH-PET/CT and ultrasound showed persistence of the uptake/nodule. Whole exome sequencing showed Arg15Cys mutation in the AP2S1 gene characteristic of FHH type-3. Conclusions: In this new case of FHH type-3, FCH-PET/CT failed to localize to the hyperplastic parathyroid glands and localized instead to apparently a lymph node. This, together with increased urinary calcium after vitamin D supplementation, led to unnecessary parathyroidectomy. Given the increasingly lower cost of genetic testing and the cost of follow up and unnecessary surgery, it may prudent to include genetic testing for FHH early on in patients with mild PTH-dependent hypercalcemia.

Lamivudine is a synthetic nucleoside analogue to cytosine with a modified sugar moiety. It has potent action against Human Immunodeficiency Virus and chronic hepatitis. Recently, studies have also shown that lamivudine (3TC) can induce apoptosis in cancer cells and inhibit their proliferation, including breast cancer. We prepared polymeric nanoparticles using the double emulsification technique to incorporate polycaprolactone (PCL) as the polymer and lamivudine as the active compound. The nanoparticles were characterized by atomic force microscopy and dynamic light scattering. Then we carried out a full set of in vitro and in vivo analyses, including measurement of cytotoxicity, radiolabeling, biodistribution and biochemistry. The results showed the formation of 273 nm spherical nanoparticles with monodisperse behavior (PDI = 0.052). The radiolabeling with ^99mTc demonstrated the feasibility of the direct radiolabeling process. The cytotoxicity corroborated the potential against the triple-negative breast cancer line (MDA-MB-231). The biodistribution assay revealed high uptake in the liver, small and large intestines and bladder, besides the presence of nanoparticles in the urine. The in vivo biochemistry analysis showed alterations in some enzyme levels, including: alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma GT (GGT), creatinine (CRE), amylase (MAS), lactate dehydrogenase pyruvate (LDH-P) and glucose (GLU). Finally, we performed theoretical studies of molecular docking, molecular dynamics and interactions between lamivudine and key proteins regulating necroptosis, including epidermal growth factor receptor (EGFR), receptor-interacting protein kinase 1 (RIPK1), and receptor-interacting protein kinase 3 (RIPK3). Theoretical results showed lamivudine's adaptability to the binding sites of these proteins, with potential for optimization to enhance hydrophobic interactions and binding affinity. The findings demonstrated the efficacy of lamivudine against breast cancer cells, and the need to better understand the interplay of nanosystems with biochemical parameters.