Impact of Zero-Valent Iron Nanoparticles and Ampicillin on Adenosine Triphosphate and Lactate Metabolism in the Cyanobacterium Fremyella diplosiphon.

In cyanobacteria, the interplay of ATP and lactate dynamics underpins cellular energetics; their pronounced shifts in response to zero-valent iron (nZVI) nanoparticles and ampicillin highlight the nuanced metabolic adaptations to environmental challenges. In this study, we investigated the impact of nZVIs and ampicillin on Fremyella diplosiphon cellular energetics as determined by adenosine triphosphate (ATP) content, intracellular and extracellular lactate levels, and their impact on cell morphology as visualized by transmission electron microscopy. While a significant increase in ATP concentration was observed in 0.8 mg/L ampicillin-treated cells compared to the untreated control, a significant decline was noted in cells treated with 3.2 mg/L nZVIs. ATP levels in the combination regimen of 0.8 mg/L ampicillin and 3.2 mg/L nZVIs were significantly elevated (p < 0.05) compared to the 3.2 mg/L nZVI treatment. Intracellular and extracellular lactate levels were significantly higher in 0.8 mg/L ampicillin, 3.2 mg/L nZVIs, and the combination regimen compared to the untreated control; however, extracellular lactate levels were the highest in cells treated with 3.2 mg/L nZVIs. Visualization of morphological changes indicated increased thylakoid membrane stacks and inter-thylakoidal distances in 3.2 mg/L nZVI-treated cells. Our findings demonstrate a complex interplay of nanoparticle and antibiotic-induced responses, highlighting the differential impact of these stressors on F. diplosiphon metabolism and cellular integrity.

Lipid production and cellular changes in Fremyella diplosiphon exposed to nanoscale zerovalent iron nanoparticles and ampicillin.

With the dramatic decrease in fossil fuel stocks and their detrimental effects on the environment, renewable energy sources have gained imminent importance in the mitigation of emissions. As lipid-enriched energy stocks, cyanobacteria are the leading group of microorganisms contributing to the advent of a new energy era. In the present study, the impact of Nanofer 25 s nanoscale zero-valent iron nanoparticles (nZVIs) and ampicillin on lipid production and cellular structural changes in Fremyella diplosiphon strain B481-SD were investigated. Total lipid abundance, fatty acid methyl ester (FAME) compositions, and alkene production as detected by high-resolution two-dimensional gas chromatography with time-of-flight mass spectrometry (GC × GC/TOF-MS) was significantly higher (p < 0.05) in the individual application of 0.8 mg/L ampicillin, 3.2 mg/L nZVIs, and a combined regimen of 0.8 mg/L ampicillin and 3.2 mg/L nZVIs compared to the untreated control. In addition, we identified significant increases (p < 0.05) in monounsaturated fatty acids (MUFAs) in F. diplosiphon treated with the combination regimen compared to the untreated control, 0.8 mg/L of ampicillin, and 3.2 mg/L of nZVIs. Furthermore, individual treatment with 0.8 mg/L ampicillin and the combination regimen (0.8 mg/L ampicillin + 3.2 mg/L nZVIs) significantly increased (p < 0.05) Nile red fluorescence compared to the untreated control, indicating neutral membrane lipids to be the main target of ampicillin added treatments. Transmission electron microscopy studies revealed the presence of single-layered thylakoid membranes in the untreated control, while complex stacked membranes of 5-8 layers were visualized in ampicillin and nZVI-treated F. diplosiphon. Our results indicate that nZVIs in combination with ampicillin significantly enhanced total lipids, essential FAMEs, and alkenes in F. diplosiphon. These findings offer a promising approach to augment the potential of using the strain as a large-scale biofuel agent.

Impact of Ascorbic Acid on Zero-Valent Iron Nanoparticle and UV-B Mediated Stress in the Cyanobacterium, Fremyella diplosiphon.

Fremyella diplosiphon is an ideal third-generation biofuel source due to its ability to produce transesterified lipids. While nanofer 25s zero-valent iron nanoparticles (nZVIs) improve lipid production, an imbalance between reactive oxygen species (ROS) and cellular defense can be catastrophic to the organism. In the present study, the effect of ascorbic acid on nZVI and UV-induced stress in F. diplosiphon strain B481-SD was investigated, and lipid profiles in the combination regimen of nZVIs and ascorbic acid compared. Comparison of F. diplosiphon growth in BG11 media amended with 2, 4, 6, 8, and 10 mM ascorbic acid indicated 6 mM to be optimal for the growth of B481-SD. Further, growth in 6 mM ascorbic acid combined with 3.2 mg/L nZVIs was significantly higher when compared to the combination regimen of 12.8 and 51.2 mg/L of nZVIs and 6 mM ascorbic acid. The reversal effect of UV-B radiation for 30 min and 1 h indicated that ascorbic acid restored B481-SD growth. Transesterified lipids characterized by gas chromatography-mass spectrometry indicated C16 hexadecanoate to be the most abundant fatty acid methyl ester in the combination regimen of 6 mM ascorbic acid and 12.8 mg/L nZVI-treated F. diplosiphon. These findings were supported by microscopic observations in which cellular degradation was observed in B481-SD cells treated with 6 mM ascorbic acid and 12.8 mg/L nZVIs. Our results indicate that ascorbic acid counteracts the damaging effect of oxidative stress produced by nZVIs.

Augmentation of the Photoreactivation Gene in Fremyella diplosiphon Confers UV-B Tolerance.

In spite of the enormous potential of cyanobacteria as a renewable energy source, elevated UV exposure is a major impediment to their commercial viability and productivity. Fremyella diplosiphon is a widely explored cyanobacterium with great biofuel capacity due to its high lipid content. To enhance UV stress tolerance in this species, we overexpressed the photoreactivation gene (phr A) that encodes for photolyase DNA repair enzyme in the wild type F. diplosiphon (B481-WT) by genetic transformation. Our efforts resulted in a transformant (B481-ViAnSa) with a 3808-fold increase in the phr A mRNA transcript level and enhanced growth under UV-B stress. Additionally, DNA strand breaks in the transformant were significantly lower after 12 and 16 h of UV radiation, with significantly higher dsDNA recovery in B481-ViAnSa (98.1%) compared to that in B481-WT (81.5%) at 48 h post irradiation. Photosystem II recovery time in the transformant was significantly reduced (48 h) compared to that in the wild type (72 h). Evaluation of high-value fatty acid methyl esters (FAMEs) revealed methyl palmitate, the methyl ester of hexadecenoic acid (C16:0), to be the most dominant component, accounting for 53.43% of the identified FAMEs in the transformant. Results of the study offer a promising approach to enhance UV tolerance in cyanobacteria, thus paving the way to large-scale open or closed pond cultivation for commercial biofuel production.

Antibiotic-Induced Changes in Pigment Accumulation, Photosystem II, and Membrane Permeability in a Model Cyanobacterium.

Fremyella diplosiphon is a well-studied a model cyanobacterium for photosynthesis due to its efficient light absorption potential and pigment accumulation. In the present study, the impact of ampicillin, tetracycline, kanamycin, and cefotaxime on pigment fluorescence and photosynthetic capacity in Fremyella diplosiphon strains B481-WT and B481-SD was investigated. Our results indicated that both strains exposed to kanamycin from 0.2 to 3.2 mg/L and tetracycline from 0.8 to 12.8 mg/L enhanced growth and pigment accumulation. Additionally, B481-SD treated with 0.2-51.2 mg/L ampicillin resulted in a significant enhancement of pigment fluorescence. A detrimental effect on growth and pigmentation in both the strains exposed to 6.4-102.5 mg/L kanamycin and 0.8-102.5 mg/L cefotaxime was observed. Detection of reactive oxygen species revealed highest levels of oxidative stress at 51.2 and 102.5 mg/L kanamycin for B481-SD and 102.5 mg/L for B481-WT. Membrane permeability detected by lactate dehydrogenase assay indicated maximal activity at 0.8 mg/L ampicillin, kanamycin, and tetracycline treatments on day 6. Abundant vacuolation, pyrophosphate, and cyanophycin granule formation were observed in treated cells as a response to antibiotic stress. These findings on the hormetic effect of antibiotics on F. diplosiphon indicate that optimal antibiotic concentrations induce cellular growth while high concentrations severely impact cellular functionality. Future studies will be aimed to enhance cellular lipid productivity at optimal antibiotic concentrations to disintegrate the cell wall, thus paving the way for clean bioenergy applications.

Zero-Valent Iron Nanoparticles Induce Reactive Oxygen Species in the Cyanobacterium, Fremyella diplosiphon.

Nanoscale zero-valent iron nanoparticles (nZVIs) are known to boost biomass production and lipid yield in Fremyella diplosiphon, a model biodiesel-producing cyanobacterium. However, the impact of nZVI-induced reactive oxygen species (ROS) in F. diplosiphon has not been evaluated. In the present study, ROS in F. diplosiphon strains (B481-WT and B481-SD) generated in response to nZVI-induced oxidative stress were quantified and the enzymatic response determined. Lipid peroxidation as a measure of oxidative stress revealed significantly higher malondialdehyde content (p < 0.01) in both strains treated with 3.2, 12.8, and 51.2 mg L-1 nZVIs compared to untreated control. In addition, ROS in all nZVI-treated cultures treated with 1.6-25.6 mg L-1 nZVIs was significantly higher than the untreated control as determined by the 2',7'-dichlorodihydrofluorescein diacetate fluorometric probe. Immunodetection using densitometric analysis of iron superoxide dismutase (SOD) revealed significantly higher SOD levels in both strains treated with nZVIs at 51.2 mg L-1. In addition, we observed significantly higher (p < 0.001) SOD levels in the B481-SD strain treated with 6.4 mg L-1 nZVIs compared to 3.2 mg L-1 nZVIs. Validation using transmission electron microscopy equipped with energy-dispersive X-ray spectroscopy (EDS) revealed adsorption of nZVIs with a strong iron peak in both B481-WT and B481-SD strains. While the EDS spectra showed strong signals for iron at 4 and 12 days after treatment, a significant decrease in peak intensity was observed at 20 days. Future efforts will be aimed at studying transduction mechanisms that cause metabolic and epigenetic alterations in response to nZVIs in F. diplosiphon.

Comparison of echocardiographic findings in patients with nonfunctioning adrenal incidentalomas.

Adrenal incidentalomas (AIs) are usually discovered incidentally after imaging unrelated to adrenal glands. We aimed to evaluate standard risk factors for systemic atherosclerosis and echocardiographic changes in patients with nonfunctioning AIs and compare them with normal subjects. We evaluated 70 patients diagnosed with AIs and 51 healthy controls. Mean levels were determined for HbA1c, LDL, uric acid, fasting plasma insulin, HOMA, and neutrophil-to-lymphocyte ratio (NLR), and these values were found to be significantly higher in the patients than the controls. The mean left atrial diameter, interventricular septum thickness, posterior wall thickness, left ventricular mass, E-wave deceleration time, isovolumetric relaxation time, and the median ratio of the early transmittal flow velocity to the early diastolic tissue velocity (E/Em) were higher in patients with AIs compared to controls. The mitral annular early diastolic velocity was lower in patients with AIs. The mean aortic diastolic diameter, stiffness index (SI), and aortic strain were higher, and aortic distensibility was lower in the patients. The mean right ventricular diameter, right atrial major-axis diameter, and right atrial minor-axis diameter were statistically higher in the patient group than the controls. A negative correlation was found between the NLR and aortic strain and aortic distensibility, while a positive correction was found between the NLR and SI. We found altered left ventricular (LV) and right ventricular (RV) echocardiographic findings in patients with AIs without known cardiovascular disease. Aortic stiffness was also increased. These changes may be related to an increase in cardiovascular risk factors in AI patients.

Visceral fat measurement by ultrasound as a non-invasive method - can it be useful in evaluating subclinical atherosclerosis in male patients with hypopituitarism and growth hormone deficiency?

INTRODUCTION: Growth hormone (GH) deficiency, either isolated or combined with other pituitary hormone deficiencies, is associated with increased mortality and abnormal body composition, particularly visceral adiposity. We aimed to investigate the effects of GH deficiency with or without sex steroid deficiencies on ultrasonographic visceral fat (VF) and cardiovascular risk markers in patients with hypopituitarism on conventional hormone replacement therapy. MATERIAL AND METHODS: Forty hypopituitarism patients (24 women, 16 men; mean age 48 ± 16.1 years) with GH deficiency and 15 age- and sex-matched healthy controls were included in this cross-sectional study. The patients were stable on conventional hormone replacement but they were not on GH therapy. Patients who had sex steroid replacement were classified as Group 1 (n = 19), and patients who did not use sex steroids were classified as Group 2 (n = 21). Anthropometric measurements were performed. VF in three regions, subcutaneous fat, and carotid intima-media thickness (CIMT) were measured. VF volume was calculated by using a formula. RESULTS: Visceral fat volume and mean CIMT were significantly higher in patients than healthy controls (p = 0.001 and 0.019 respectively). Homocysteine and hs-CRP were higher in patients (p < 0.05). In males, VF volume and VF thickness measured between abdominal muscle and splenic vein were significantly correlated with CIMT (r = 0.54, p = 0.047 and r = 0.66, p = 0.010 respectively). Furthermore, there was a strong positive correlation between VF thickness in pararenal region and homocysteine (r = 0.74, p = 0.001) in males. CONCLUSIONS: VF volume evaluated by ultrasound can be accepted as a cause of subclinical atherosclerosis in GH deficient hypopituitary patients, particularly males.

The frequency of malignancy and the relationship between malignancy and ultrasonographic features of thyroid nodules with indeterminate cytology.

Various approaches are available for the management of nodules that are evaluated to be indeterminate according to the results of thyroid fine needle aspiration biopsy. The present study aimed to determine the rate of malignancy and the ultrasonographic features that could be used as predictor of malignant pathologies at the nodules with indeterminate cytology. A total of 201 patients who underwent total thyroidectomy and whose fine needle aspiration biopsy results were evaluated to be Hurthle cell lesion (n = 99), follicular neoplasm (n = 61) and [corrected] suspicious for malignancy (n = 41) were enrolled in this study. Of these patients, 178 were females (88.6 %) and 23 were males (11.4 %). The rates of malignancy were found to be 33.3 % in the Hurthle cell lesion group, 23.0 % in the follicular neoplasm group and 53.7 % in the suspicious for malignancy group (p = 0.006). The comparison of the ultrasonographic characteristics of the malignant and benign nodules revealed hypoechogenicity and microcalcification to be more common in malignant nodules (34.3 vs. 16.9 %, p = 0.005; 27.1 vs. 13.1 %, p = 0.014; respectively). While 92.3 % of the malignant nodules were ≥1 cm, 82.9 % of the benign nodules were ≥1 cm (p = 0.042). We believe that as the patients at Hurthle cell lesion group have higher risk of malignancy than the patients with Follicular Neoplasia so total thyroidectomy will be suitable for these patients. [corrected]. In addition, microcalcification and hypoechoic nodules at patients with indeterminate cytology can be related with increased risk of malignancy. [corrected].

A Case of Primary Hyperparathyroidism due to Intrathyroidal Parathyroid Cyst.

Parathyroid cysts constitute 0.08-3.41% of all parathyroid masses. Intrathyroidal parathyroid cysts, however, are rare conditions with only a few cases being reported. Most of the parathyroid cysts are found to be nonfunctional and functional cysts are generally thought to be due to cystic degeneration of parathyroid adenomas. A cystic, smooth contoured lesion of 24 × 19 × 16 mm was observed in left thyroid lobe of a 76-year-old woman during ultrasonography which was performed as routine workup for primary hyperparathyroidism. It was defined as a cystic thyroid nodule at first. Tc(99m) sestamibi scintigraphy was performed to see any parathyroid lesions, but no radioactive uptake was observed. Intact parathormone (iPTH) level was found to be >600 pg/mL in cyst aspiration fluid. Left lobectomy was performed, with a diagnosis of primary hyperparathyroidism due to functional parathyroid cyst. Serum iPTH level was decreased >50% postoperatively and histopathological evaluation was consistent with an encapsulated parathyroid adenoma with a cystic center. Parathyroid cysts are among rare causes of primary hyperparathyroidism. Diagnosis is made by markedly increased iPTH level in cyst fluid and observation of parathyroid epithelium lining the cyst wall.

Comparison of efficiencies of michigan neuropathy screening instrument, neurothesiometer, and electromyography for diagnosis of diabetic neuropathy.

Aim. This study compares the effectiveness of Michigan Neuropathy Screening Instrument (MNSI), neurothesiometer, and electromyography (EMG) in detecting diabetic peripheral neuropathy in patients with diabetes type 2. Materials and Methods. 106 patients with diabetes type 2 treated at the outpatient clinic of Ankara Numune Education and Research Hospital Department of Endocrinology between September 2008 and May 2009 were included in this study. Patients were evaluated by glycemic regulation tests, MNSI (questionnaire and physical examination), EMG (for detecting sensorial and motor defects in right median, ulnar, posterior tibial, and bilateral sural nerves), and neurothesiometer (for detecting alterations in cold and warm sensations as well as vibratory sensations). Results. According to the MNSI score, there was diabetic peripheral neuropathy in 34 (32.1%) patients (score ≥2.5). However, when the patients were evaluated by EMG and neurothesiometer, neurological impairments were detected in 49 (46.2%) and 79 (74.5%) patients, respectively. Conclusion. According to our findings, questionnaires and physical examination often present lower diabetic peripheral neuropathy prevalence. Hence, we recommend that in the evaluation of diabetic patients neurological tests should be used for more accurate results and thus early treatment options to prevent neuropathic complications.

Relationship between obstructive sleep apnea syndrome and thyroid diseases.

Obstructive sleep apnea syndrome (OSAS) is a widespread disorder characterized by recurrent, partial, or complete episodes of apnea due to upper airway tract obstruction during sleep. OSAS frequency is likely to increase in hypothyroidism because of obesity, macroglossia, dysfunctional upper respiratory tractus (URT) musculature, deposition of mucopolysaccharides in URT tissues, and decreased ventilatory control. This study examines the relationship between OSAS and thyroid disease in OSAS subjects. This study includes 150 polysomnographically diagnosed OSAS patients (50 mild, 50 moderate, 50 severe OSAS cases) treated at Endocrinology and Metabolism Department of Ankara Numune Training and Research Hospital between January 2010 and May 2011 and 32 non-OSAS control subjects. All patients were given serum TSH, free T3 (fT3), free T4 (fT4), anti thyroid peroxidase (Anti-TPO), and anti-thyroglobulin (anti-TG) tests, as well as thyroid ultrasounds. We did not find any difference in prevalence of hypothyroidism, numbers of nodules and parenchyma heterogenicity determined by ultrasound, between OSAS subgroups and controls (p > 0,05). In this study, functional and ultrasonographic examination of the thyroid gland did not reveal any relationship between OSAS and thyroid disease. We believe hence that long-term follow-up studies can establish the possible significance of routine evaluation of OSAS patients for thyroid disease.

Effect of nebivolol and metoprolol treatments on serum asymmetric dimethylarginine levels in hypertensive patients with type 2 diabetes mellitus.

OBJECTIVE: Elevated asymmetric dimethylarginine (ADMA) levels, an endogenous inhibitor of nitric oxide synthase, are an important cardiovascular risk factor. In patients with diabetes, increased ADMA levels have been reported, which may be associated with endothelial dysfunction. In this study, effect of nebivolol on serum ADMA levels in hypertensive patients with type 2 diabetes have been compared with metoprolol, an another beta-blocker. METHODS: A total of 54 patients (27 female, 27 male; mean age: 53.0+/-8.7 years) with type 2 diabetes and hypertension were included in this randomized, open-label, prospective study. Patients were randomized to receive either nebivolol 5 mg/day (n=28) or metoprolol 100 mg/day (n=26) for 12 weeks. When the patients could not reach target blood pressure levels at the end of week 4, indapamide (2.5 mg/day) was added. Enzyme Linked Immunosorbent Assay was used for serum ADMA measurements. RESULTS: Similar reductions in blood pressure values were observed in both groups (p>0.05). In nebivolol group, there were no significant changes in serum ADMA levels compared to baseline (0.6+/-0.2 micromol/l vs 0.6+/-0.1 micromol/l, p>0.05), whereas in metoprolol group a 35.6% increase in serum ADMA levels was observed (0.6+/-0.1 micromol/l vs 0.7+/-0.2 micromol/l, p<0.01). CONCLUSION: We observed a significant increase in ADMA levels, a marker of endothelial dysfunction, during metoprolol treatment, whereas nebivolol had neutral effects on ADMA levels in patients with type 2 diabetes mellitus and hypertension.

Hydatid cyst presenting as an eosinophilic pleural effusion.

A 61-year-old woman presented with an eosinophilic pleural effusion, secondary to transdiaphragmatic intrapleural spread of an hepatic hydatid cyst. Right posterolateral thoracotomy and frenotomy revealed a loculated pleural effusion associated with a 10 x 8 cm hydatid cyst in the posterior segment of the liver. Hydatid disease should be included in the differential diagnosis of eosinophilic pleural effusions in endemic regions.