Investigating and Optimizing Insulin Partitioning with Conjugated Au Nanoparticles in Aqueous Two-Phase Systems Using Response Surface Methodology.

This study investigated the impact of bioconjugation on the partitioning of insulin, a clinically valuable protein, in an aqueous two-phase system. Gold nanoparticles of different sizes were synthesized and conjugated with insulin. Analysis of the conjugated insulin showed that the insulin remains fully active. Conjugated gold nanoparticles (AuNPs/insulin) were used in polyethylene glycol (PEG)-dextran aqueous two-phase systems to investigate the effect of pH, PEG and dextran molecular weights, PEG and dextran concentrations, AuNPs/insulin dosage, and nanoparticle size on the partition coefficient. These systems were chosen for their biocompatibility and low toxicity. Response surface methodology with D-optimal design was used to model and optimize these systems and their affected parameters. At the optimum condition of a pH = 8 system containing 21% PEG 4000, 5% dextran 100,000, and 100 IU AuNPs/insulin, the partition coefficient of AuNPs/insulin was found to be 192.96, which is in agreement with the empirical partition coefficient of 189.2. This is significantly higher than the partition coefficient of free insulin in a similar system. This approach could be used to overcome limitations in the feasibility of aqueous two-phase systems for industrial-scale purification of biomolecules and biopharmaceuticals.

Nerve Root Metastasis of Breast Carcinoma Detected by Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Scan.

A 35-year-old woman with history of breast cancer was referred to our department for restaging by F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) scan. Aside from multiple other FDG-avid metastatic lesions, a segmental increased FDG uptake was visualized along the asymmetrically thicker left first sacral nerve root, highly concerning for metastatic disease, which was confirmed by the subsequently performed magnetic resonance imaging. Our case highlights the capability of FDG PET/CT scan in the correct diagnosis of the extremely rare phenomenon of nerve root metastasis as well as the importance of differentiating FDG-avid lumbosacral nerve roots from adjacent skeletal metastases.

A review: studying the effect of graphene nanoparticles on mechanical, physical and thermal properties of polylactic acid polymer.

Polylactic acid (PLA) is a linear aliphatic polyester thermoplastic made from renewable sources such as sugar beet and cornstarch. Methods of preparation of polylactic acid are biological and chemical. The advantages of polylactic acid are biocompatibility, easily processing, low energy loss, transparency, high strength, resistance to water and fat penetration and low consumption of carbon dioxide during production. However, polylactic acid has disadvantages such as hydrophobicity, fragility at room temperature, low thermal resistance, slow degradation rate, permeability to gases, lack of active groups and chemical neutrality. To overcome the limitations of PLA, such as low thermal stability and inability to absorb gases, nanoparticles such as graphene are added to improve its properties. Extensive research has been done on the introduction of graphene nanoparticles in PLA, and all of these studies have been studied. In this study, we intend to study a comprehensive study of the effect of graphene nanoparticles on the mechanical, thermal, structural and rheological properties of PLA/Gr nanocomposites and also the effect of UV rays on the mechanical properties of PLA/Gr nanocomposites.

Utility of 99mTc-Sestamibi Heart/Liver Uptake Ratio in Screening Nonalcoholic Fatty Liver Disease During Myocardial Perfusion Imaging.

Purpose: Nonalcoholic fatty liver disease (NAFLD) is the most common chronic hepatic disease worldwide, with functional impairment of the mitochondria occurring from early stages. Technetium-99m methoxy-isobutyl-isonitrile (99mTc-MIBI) is a lipophilic agent trapped in the mitochondria. This study aims to evaluate the utility of 99mTc-MIBI heart/liver uptake ratio in screening for NAFLD during myocardial perfusion imaging (MPI). Methods: Seventy eligible patients underwent a 2-d rest/stress 99mTc-MIBI scan with a 2-min planar image acquired in rest phase, at 30, 60, and 120 min postradiotracer administration. Heart/liver uptake ratio was calculated by placing identical regions of interest on the heart and liver dome. All patients underwent liver ultrasound and were allocated into groups A, having NAFLD; and B, healthy individuals without NAFLD. Results: Mean count per pixel heart/liver ratios gradually increased over time in either group; nonetheless the values were significantly higher in group A, regardless of acquisition timing; with the p-value equal to 0.007, 0.014, and 0.010 at 30, 60, and 120 min, respectively. Conclusion: Determining 99mTc-MIBI heart/liver uptake ratio during rest phase in patients undergoing MPI may be a useful, noninvasive screening method for NAFLD; with no additional cost, radiation burden, or adverse effects in these patients. Trial registration number: IR.SBMU.MSP.REC.1398.308.

Radioiodine-Avid Paravertebral Bronchogenic Cyst Mimicking Neurofibroma: A Diagnostic Pitfall.

ABSTRACT: The whole-body postablation scan of a 38-year-old man, with history of papillary thyroid cancer, revealed a focus of intense 131I accumulation about the lower thoracic vertebrae. SPECT/CT revealing a soft tissue lesion adjacent the T9 to T10 vertebrae, which was reported as neurofibroma on the subsequently performed MRI. However, the lesion was confirmed as a bronchogenic cyst on biopsy. Respecting that unlike neurofibroma, immunohistochemistry studies have confirmed Na-I symporter expression in bronchogenic epithelium; our case highlights that, although rare, paravertebral bronchogenic cysts should be considered in differential diagnosis of radioiodine-avid paravertebral lesions.

68Ga-PSMA PET/CT Scan Leading to Diagnosis of PSMA-Positive Rectal Adenocarcinoma in a Patient With Prostate Cancer.

ABSTRACT: A 59-year-old prostate cancer patient, status post radical prostatectomy, was referred to our department for restaging with 68Ga-prostate-specific membrane antigen (PSMA) PET/CT scan. Aside multiple metastatic lesions involving pelvic lymph nodes as well as the right femoral trochanter, a PSMA-positive rectal wall thickening was detected. Colonoscopy correlation and tissue diagnosis, recommended to rule out accompanying primary malignancy, confirmed the presence of rectal adenocarcinoma. This case signifies the importance of requesting pathological correlation for unexplained PSMA-positive lesions, emphasizing the potential role PSMA ligands may play in detecting occult second primary malignancies, especially synchronous/metachronous colorectal cancers.

Effect of proton pump inhibitors and H2 antagonists on gastric wall uptake in myocardial perfusion scan with 99mTc-sestamibi.

BACKGROUND: Proton pump inhibitors (PPIs) have been speculated to cause gastric wall uptake (GWU) in MPI scans. However, the uptake mechanism and prevention methods are less studied. In this prospective trial we aimed to evaluate the impact of gastroprotective medications on GWU and its solutions. METHODS: 351 consecutive patients, scheduled for 2-day rest/stress 99mTc-MIBI scan, were distributed into 5 groups. 3-7 days following the baseline rest scan, the stress scan was acquired after intervention in the trial group, consisting of patients with history of PPI intake, randomly assigned to 3 subgroups: discontinuing PPIs(A), replacement with H2 blockers (B), and continuing PPIs (C). Patients receiving H2 blockers, continued it as before (D) and the remaining patients were the control group (E). GWU was graded compared to the myocardial uptake. RESULTS: In the rest phase, all groups had significantly higher GWU compared to the control group. In the stress phase, group A had less GWU than group B (P-value < 0.05) and both of them had significantly less GWU compared to group C (P-value < 0.001). There was no significant difference between PPI discontinuation periods of 3-5 days versus 5-7 days. There was a significant association between duration of oral PPI intake, but not IV PPIs, and GWU. GWU was significantly lower with oral compared to IV PPI administration. CONCLUSION: PPIs significantly increase GWU and discontinuing them for at least 3-5 days significantly reduces GWU. H2 antagonists are a good alternative in patients who cannot tolerate dyspepsia symptoms.

Subacute thyroiditis following COVID-19 vaccination.

Physicians should be alert about the possibility of subacute thyroiditis (SAT) being induced by COVID-19 vaccination. SAT may present with anterior neck pain, extended fever or palpitation in recently vaccinated patients, which should not be easily dismissed as expected post-vaccination flu-like symptoms, thereby, facilitating in time diagnosis and treatment.

The safety of povidone-iodine solution in tympanoplasty: a randomised, triple-blind, placebo-controlled study.

OBJECTIVE: Nowadays, povidone-iodine is commonly used as a disinfectant in head and neck procedures. The present study investigated the effect of povidone-iodine, which is used as a disinfectant solution in tympanoplasty, on patients' hearing. METHODS: A povidone-iodine solution was used as disinfection in chronic otitis media patients undergoing tympanoplasty. In the intervention group, 5% povidone-iodine, was applied to the external auditory canal and remained there for 10 minutes. In the control group, povidone-iodine was used but not allowed to enter the external auditory canal by inserting cotton wool into the canal. To evaluate the adverse effect of povidone-iodine on hearing, the bone conduction level was compared between groups at baseline and one month after exposure. RESULTS: Bone conduction levels at frequencies 500 Hz, 1 kHz, 2 kHz, 3 kHz, 4 kHz and 8 kHz and mean of bone conduction level in 500 Hz, 1 kHz and 2 kHz were measured and compared respectively between intervention and control group. No significant difference was seen between bone conduction levels of above frequencies and mean frequencies before and one month after surgery. (P-value = 0.321, 0.432, 0.219, 0.489, 0.61, 0.112, 0.324 respectively). CONCLUSIONS: According to the present study, currently available 5% povidone-iodine did not affect hearing and therefore, can be comfortably used for preparation and disinfection in otologic surgeries.

Comparison of radioiodine ablation rates between low versus high dose, and according to the surgeon's expertise in the low-risk group of differentiated thyroid cancer.

Radioiodine ablation following surgery is the accepted treatment for patients with differentiated thyroid cancer (DTC). Since that surgical volume and radioiodine dose can have impact on treatment outcome, we aimed to evaluate them on the treatment outcome of low-risk DTC patients. Low-risk DTC patients were classified into four groups, including (1) thyroidectomy was performed by thyroid surgeon and low-dose (1850 MBq [30 mCi]) radioiodine was administered (n = 17), (2) thyroidectomy was performed by thyroid surgeon and high-dose (3700 MBq [100 mCi]) radioiodine was administered (n = 10), (3) thyroidectomy was performed by general surgeon and low-dose radioiodine was administered (n = 22), and (4) thyroidectomy was performed by general surgeon and high-dose radioiodine was administered (n = 29). All patients were followed at least for 6 months and also for evaluation of treatment success, neck sonography, thyroid-stimulating hormone-off, thyroglobulin (Tg)-off, and anti-Tg-off tests were performed. Furthermore, two common radioiodine treatment-associated side effects, including dry mouth, and nausea/vomiting were assessed for all patients. Seventy-eight low-risk DTC patients (female: 70 [89.7%]; male: 8 [10.3%]) aged from 18 to 78 years old with mean of 41.96 ± 13.42 years were enrolled in this study. In total, the treatment was successful in 96.2% of patients. There was no significant difference in treatment success among groups (P > 0.05), while there was a significant association among administered activity and side effects. In low dose patients, only one patient complained from dry mouth; however, 11/39 patients who received high dose of iodine complained from dry mouth (P = 0.002). In addition, 9/39 high dose patients suffered from vomiting/nausea, while none of low-dose patients suffered from vomiting/nausea (P = 0.001). In low-risk DTC patients, surgical volume and amounts of radioiodine had no significant impact on treatment results; therefore, low dose radioiodine following thyroidectomy may be preferable to low-risk DTC patients to avoid side effects.

Incidental Finding of Benign Trichilemmal Cysts on 99mTc-Octreotide Scan.

A 63-year-old woman with neuroendocrine carcinoma of the colon was referred to our department for staging with Tc-octreotide scan. Two focal, highly intense, superficial lesions were detected in patient's scalp and paralumbar region, medial to the right kidney. Pathology correlation was recommended, revealing them both to be benign trichilemmal cysts. This unexpected finding strengthens the hypothesis of Merkel cell carcinoma and trichilemmal cysts originating from pluripotent stem cells of adnexal epithelium, making a neuroendocrine differentiation for the latter plausible.

Excellent Response to Lower Dose of 177Lu-PSMA-617 in a Metastatic Castration-Resistant Prostate Cancer Patient With a Transplanted Kidney.

A 68-year-old man with metastatic castration-resistant prostate cancer and widespread bone metastases as well as a history of kidney transplant, underwent 5 cycles of Lu-prostate-specific membrane antigen 617 therapies in our department. Being more cautious of the radiation burden imposed on the transplanted kidney, a lower average dose of 4 GBq per cycle was administered (instead of the more routine 6.0-7.4 GBq per cycle). However, excellent response was noted and serum creatinine level of 0.8 mg/dL remained stable.

Prevalence of Color Vision Deficiency and its Correlation with Amblyopia and Refractive Errors among Primary School Children.

PURPOSE: To determine the prevalence of color vision deficiency (CVD) and its correlation with amblyopia and refractive errors among primary school children. METHODS: In this population-based cross-sectional study, 2160 children were selected from 36 primary schools; 60 students were from each school (10 students in each grade), with equal sex distribution. A complete eye examination including refraction using a photorefractometer, determination of visual acuity (VA) and color vision using a Yang vision tester, and evaluation of ocular media opacity using a direct ophthalmoscope was performed. Children who could not answer at least 4 plates of the Ishihara color test were considered as color vision deficient subjects. Amblyopia was determined if pinhole VA was worse than 0.3 LogMAR (equal to 20/40). RESULTS: The prevalence of CVD was 2.2% (95% CI: 1.5% to 3%) which was higher in male subjects (37 [3.5%] boys vs. 11 [1.0%] girls, P < 0.001). Mean VA was lower among students with CVD as compared to normal color vision children (P = 0.035) and amblyopia was observed in 8.3% (95% CI: 0.2% to 16.4%) of patients with CVD versus 2.1% (95% CI: 1.5% to 2.08%) of children with normal color vision perception (P = 0.005). A statistically significant correlation between lower VA and CVD was observed (P = 0.023). CONCLUSION: Although CVD was correlated with lower VA and amblyopia, there was no relationship between CVD and the type of amblyopia, refractive error, anisometropia or strabismus.

Accuracy and Repeatability of Refractive Error Measurements by Photorefractometry.

PURPOSE: To determine the accuracy of photorefraction and autorefraction as compared to cycloautorefraction and to detect the repeatability of photorefraction. METHODS: This diagnostic study included the right eyes of 86 children aged 7-12 years. Refractive status was measured using photorefraction (PlusoptiX SO4, GmbH, Nürnberg, Germany) and autorefraction (Topcon RM800, USA) with and without cycloplegia. Photorefraction for each eye was performed three times to assess repeatability. RESULTS: The overall agreement between photorefraction and cycloautorefraction was over 81% for all refractive errors. Photorefractometry had acceptable sensitivity and specificity for myopia and astigmatism. There was no statistically significant difference considering myopia and astigmatism in all comparisons, while the difference was significant for hyperopia using both amblyogenic (P = 0.006) and nonamblyogenic criteria (P = 0.001). A myopic shift of 1.21 diopter (D) and 1.58 D occurred with photorefraction in nonamblyogenic and amblyogenic hyperopia, respectively. Using revised cut-off points of + 1.12 D and + 2.6 D instead of + 2.00 D and + 3.50 D improved the sensitivity of photorefractometry to 84.62% and 69.23%, respectively. The repeatability of photorefraction for measurement of myopia, astigmatism and hyperopia was acceptable (intra-cluster correlation [ICC]: 0.98, 0.94 and 0.77, respectively). Autorefraction results were significantly different from cycloautorefraction in hyperopia (P < 0.0001), but comparable in myopia and astigmatism. Also, noncycloglegic autorefraction results were similar to photorefraction in this study. CONCLUSION: Although photorefraction was accurate for measurement of myopia and astigmatism, its sensitivity for hyperopia was low which could be improved by considering revised cut-off points. Considering cut-off points, photorefraction can be used as a screening method.

Macular thickness and amblyopia.

PURPOSE: To compare macular thickness in children with functional amblyopia and those without amblyopia using optical coherence tomography (OCT). METHODS: This case-control study was conducted on 93 children aged 3-10 years including 44 cases with unilateral amblyopia and 49 subjects without amblyopia. Amblyopic eyes were considered as the case group and their fellow eyes as internal controls; eyes of non-amblyopic children served as the external control. Macular thickness of all eyes were measured by optical coherence tomography in the center (foveola), 1 mm ring (fovea), and 3 and 6 mm rings and compared. RESULTS: Although macular thickness was generally not different between the study groups, there was a significant difference in central macular thickness between eyes with moderate to severe amblyopia and the external controls (P = 0.037). Foveal thickness difference exceeding 10 microns between fellow eyes was detected in a larger number of amblyopic children as compared to non-amblyopic controls (P = 0.002). Mean foveal thickness was greater in boys (P = 0.037) but there was no significant difference in foveal thickness among various types of refractive errors. CONCLUSION: Although there was no significant relationship between macular thickness and amblyopia, foveolar thickness in eyes with moderate to severe amblyopia was significantly greater than the external controls. Further studies with more cases of moderate to severe amblyopia are recommended.