Successful Airway Management Using Awake Videolaryngoscopy for a Rare Thyroid Cancer with Grade III Goitre and Intra-Tracheal Invasion

In the present report, we described a case of anticipated difficult intubation in which the access to airway was limited due to external and internal factors. Our patient presented with a large goitre, shortness of breath and mild stridor. A clinical examination and investigations were performed. An intra-tracheal subglottic mass visible on a positron emission tomography scan was nearly occluding the lumen. The clinical diagnosis was thyroid cancer with intra-tracheal invasion. For patients with a large thyroid cancer, airway management can be complicated, using both regional invasion and intrathoracic extension, due to the effect of the mass on the airway and major vessels. This approach has a great potential for leading to complete airway obstruction after the induction of general anaesthesia. Here, we aimed to discuss the meticulous planning and preparation for the intubation of a conscious patient using different procedures of airway management, especially when the fibreoptic intubation failed and awake videolaryngoscopy salvaged the situation.

Promising performance of chemically exfoliated Zr-doped MoS2 nanosheets for catalytic and antibacterial applications

Nanostructured materials incorporated with biological reducing agents have shown significant potential for use in bactericidal applications. Such materials have also demonstrated considerable efficacy to counter effects of chemical toxicity. In this study, nanostructured molybdenum disulfide (MoS₂) was doped with various concentrations (2.5, 5, 7.5, 10 wt%) of zirconium (Zr) using a hydrothermal route in order to assess its antimicrobial and catalytic potential. Doped and control samples were characterized with various techniques. X-ray diffraction (XRD) analysis confirmed the presence of the hexagonal phase of MoS₂ and identification of various functional groups and characteristic peaks (Mo bonding) was carried out using FTIR spectra. Micrographs obtained from FESEM and HR-TEM showed a sheet-like surface morphology, while agglomeration of nanosheets was observed upon doping with nanoparticles. To seek further clarity regarding the layered features of S–Mo–S planes, the defect densities and electronic band structure of pure MoS₂ and doped MoS₂ samples were investigated through Raman analysis. Optical properties of Zr-doped MoS₂ nanosheets were assessed using a UV-vis spectrophotometer and the results indicated a red-shift, i.e., movement of peaks towards longer wavelengths, of the material. Dynamics of migration and recombination of excited electron–hole pairs were investigated using PL spectroscopy, which was also used to confirm the presence of exfoliated nanosheets. In addition, the synthetic dye degradation potential of pure and doped samples was investigated in the presence of a reducing agent (NaBH₄). It was noted that doped MoS₂ showed superior catalytic activity compared to undoped MoS₂. The nanocatalyst synthesized in this study exhibited enhanced antibacterial activity against E. coli and S. aureus at high concentrations (0.5, 1.0 mg/50 μl). The present study suggests a cost-effective and environmentally friendly material that can be used to remove toxins such as synthetic dyes and tannery pollutants from industrial wastewater.

Nanostructured materials incorporated with biological reducing agents have shown significant potential for use in bactericidal applications.

Quantitative analysis of Fuller's earth using laser-induced breakdown spectroscopy and inductively coupled plasma/optical emission spectroscopy

Fuller's earth, most commonly known as Multani Matti (clay) in Urdu, among its various utilizations is traditionally used in skin care cosmetics, particularly for removing blackheads and to treat oily skin. It is also used for improving skin complexion. In this paper, laser-induced breakdown spectroscopy (LIBS) was effectively employed for the quantitative investigation of various clay samples for their special uses. To get the LIBS spectra with an optimal signal-to-noise as well as for a more robust and accurate analytical investigation, different experimental parameters (laser energy, gate delay time, and the distance between target and focusing lens) were optimized before the experiments on actual samples. The analysis of emission spectra revealed the presence of many different elements, including Al, Ca, Fe, Mg, Mn, Na, K, Li, S, Si, and Zn. The electron number density and plasma temperatures were determined using the Stark broadened line profile and Boltzmann plot method, respectively. To determine the relative concentration of observed elements, we used an integrated intensity ratio method, integrated intensity of every line from all elements, and calibration free (CF)-LIBS. The prevailing condition of local thermodynamic equilibrium during the experimental executions was verified with multiple criteria. The spectral lines used in CF-LIBS were characterized for the influence from the self-absorption phenomenon, but the same was found insignificant. The findings of our LIBS system were found to agree excellently with the outcomes of the inductively coupled plasma/optical emission spectroscopy, thereby yielding a high statistical correlation factor and hence enlighten the significance of LIBS as a safe and reliable tool for elemental analysis of clay samples.

Prostate Cancer Metastasis To Cervical Node Chain-An Unusual Clinic-Pathological Finding

Prostate carcinoma is one of the most common cancers in males all around the world. Head and neck squamous cell carcinoma is amongst the leading carcinoma (HNSCC) in men especially in the sub-continent. There are around 150 lymph nodes on either side in the neck and cervical lymph nodes are a common site for head and neck malignancies to metastasize however carcinoma of prostate may in rare cases metastasize to cervical chain, therefore warranting a neck dissection. In case of unknown primary of head and neck extensive work up is required to find the primary site. Our case provided a similar picture with a single enlarged node which on biopsy to our surprise revealed adenocarcinoma of prostate.

Compositional engineering of acceptors for highly efficient bulk heterojunction hybrid organic solar cells

The wet chemical synthesis of chromium oxide (Cr₂O₃) nanoparticles (NPs) and its application in active layer of inverted bulk heterojunction organic solar cells is documented in this research. Chromium oxide NPs of 10-30 nm size range having a band gap of 2.9 eV were successfully synthesized. These NPs were used in inverted organic solar cells in amalgamation with P3HT:PCBM and PTB7:PCBM polymers. The fabricated hybrid devices improves PCE significantly for P3HT:PCBM and PTB7:PCBM systems. The photophysical energy levels, optoelectrical properties and microscopic images have been systematically studied for the fabricated devices. The introduction of Cr₂O₃ nanoparticles (NPs) enhances light harvesting and tunes energy levels into improved electrical parameters. A clear red shift and improved absorption have been observed for ternary blended devices compared to that observed with controlled organic solar cells. Apparently, when the amount of NPs in the binary polymer blend exceeds the required optimum level, there is a breakdown of the bulk heterojunction leading to lowering of the optical and electrical performance of the devices.

Hypoxia-Responsive Mesoporous Nanoparticles for Doxorubicin Delivery

Hypoxia, or low oxygen tension, is a common feature of solid tumors. Here, we report hypoxia-responsive mesoporous silica nanoparticles (HR-MSNs) with a 4-nitroimidazole-β-cyclodextrin (NI-CD) complex that is acting as the hypoxia-responsive gatekeeper. When these CD-HR-MSNs encountered a hypoxic environment, the nitroimidazole (NI) gatekeeper portion of CD-HR-MSNs disintegrated through bioreduction of the hydrophobic NI state to the hydrophilic NI state. Under hypoxic conditions, the release rate of doxorubicin (DOX) from DOX-loaded CD-HR-MSNs (DOX-CD-HR-MSNs) increased along with the disintegration of the gatekeeper. Conversely, DOX release was retarded under normoxic conditions. In vitro experiments confirmed that DOX-CD-HR-MSNs exhibit higher toxicity to hypoxic cells when compared to normoxic cells. Confocal microscopy images indicated that DOX-CD-HR-MSNs effectively release DOX into SCC-7 cells under hypoxic conditions. These results demonstrate that CD-HR-MSNs can release drugs in a hypoxia-responsive manner, and thus are promising drug carriers for hypoxia-targeted cancer therapy.

High-performance solution-based CdS-conjugated hybrid polymer solar cells

In this study, hybrid BHJ – bulk heterojunction polymer solar cells were fabricated by incorporating CdS quantum dots (QDs) in a blend of P3HT (donor) and PCBM (acceptor) using dichlorobenzene and chlorobenzene as solvents. CdS QDs at various ratios were mixed in a fixed amount of the P3HT and PCBM blend. The prepared samples have been characterized by a variety of techniques such as I–V and EQE measurements, atomic force microscopy (AFM), scanning electron microscopy (SEM) and ultraviolet-visible (UV-vis) spectroscopy. The mixing of QDs in the polymer blends improved the PCE – power conversion efficiency of the solar cells under standard light conditions. The improved PCE from 2.95 to 4.41% is mostly due to the increase in the fill factor (FF) and short-circuit current (J_sc) of the devices with an optimum amount of CdS in the P3HT:PCBM blend. The increase in J_sc possibly originated from the formation of a percolation network of CdS. The conjugation of QDs has increased the absorption of the active layers in the visible region. These results well matched as reported, conjugation of CdS in the perovskite active layer increased the absorption and PCE of the devices relative to those of the perovskite films. This increment in parameters is attributed to the decrease in charge recombinations that improved the performance of the doped device.

In this study, hybrid BHJ – bulk heterojunction polymer solar cells were fabricated by incorporating CdS quantum dots (QDs) in a blend of P3HT (donor) and PCBM (acceptor) using dichlorobenzene and chlorobenzene as solvents.

Papillary Thyroid Carcinoma within Thyroglossal Duct Cyst: Case Series and Literature Review

Introduction  Thyroglossal duct cyst (TGDC) is the most common congenital anomaly of the neck, and approximately 7% of all the adult population presents it. Ectopic thyroid tissue is found in the thyroglossal duct cyst wall in up to 65% of cases. This thyroid tissue has the potential to develop some type of malignancy, the most common of which is the papillary carcinoma of the thyroid. There are just over 270 cases of thyroglossal duct cyst malignancy reported in the literature.

Objectives  We aimed to study our population of patients in order to identify cases with thyroglossal duct cyst malignancy.

Methods  A retrospective chart review was conducted in the section of otolaryngology/head and neck surgery at a hospital in Karachi, Pakistan, from January of 2004 to December of 2014 on patients with the diagnosis of thyroglossal duct cyst.

Results  Fifty-eight patients were diagnosed with TGDC, two of whom also presented with thyroglossal duct cyst carcinoma. Both patients revealed papillary thyroid carcinoma on histopathology. Case 1 had an open biopsy before undergoing definitive surgery. Both patients underwent subsequent total thyroidectomy after Sistrunk procedure, and case 2 had selective neck dissection revealing lymph node metastasis.

Conclusion  Thyroglossal duct cyst carcinoma is a rare finding that comes as a surprise to both the patient and the surgeon. We report 2 out of 58 cases diagnosed with thyroglossal duct cyst carcinoma.

Unusual Presentation of Differentiated Thyroid Cancer Metastasis

Introduction  The rates of thyroid cancers are on a rise, especially well-differentiated thyroid cancers. This could be partly due to newer diagnostic modalities, like high-resolution ultrasound, that can pick up smaller lesions. Differentiated thyroid cancers with distant metastases are not common, and even rarer is the initial presentation with complaints not related to the neck.

Objectives  The objective of this series was to study and report the unusual cases of patients with differentiated thyroid cancer with distant metastasis. There is a lack of data in the literature on these cases, and due to the rarity of such metastases, no definite treatment protocol has been defined.

Methods  A retrospective chart review of 1,200 cases of thyroid surgeries was performed. A total of 10 cases of well-differentiated thyroid cancer on the final histopathology exam that had initially presented with usual complaints to departments other than the Otolaryngology Department were identified.

Results  A total of 6 patients had papillary carcinoma, whereas 4 patients had follicular carcinoma on final the histopathology exam. Two patients presented with iliac crest lesions, 2 with vertebral lesions one each with parapharyngeal mass, supraclavicular mass, labia majora swelling and bleeding, lung, rib and neck of femur lesion.

Conclusion  There are still no specific guidelines on how to address these patients with differentiated thyroid cancer with distant metastasis (except for the cases of bone and lung lesions) and on which treatment should be offered in case of recurrence. More studies on the subject are required.

Accuracy of frozen sections in oral cancer resections, an experience of a tertiary care hospital

The aim our study was to determine the accuracy of frozen sections in oral cancer resections. Patients who underwent oral cancer resection at Patel Hospital were included in the study. Tissues for frozen sections were obtained from the mucosal margins and tumour bed. Frozen sections were compared with the paraffin embedded sections which served as the gold standard in our study. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy and kappa statistics were calculated. A total of 299 frozen sections were obtained from 77 patients who underwent oral cancer resection, mean (3.88±0.76). Frozen sections' sensitivity in relation to permanent sections was 72.7% and specificity of 93.9%. The overall accuracy of the test was 90.9%. Kappa value was calculated to be 0.642, which showed a moderate agreement. Frozen sections are accurate enough to be used in assessing intraoperative margin assessment for tumour clearance.

Zwitterionic mesoporous nanoparticles with a bioresponsive gatekeeper for cancer therapy

To enhance cellular uptake and site-specific drug release in the tumor microenvironment, zwitterionic mesoporous silica nanoparticles (Z-MSN) were prepared by introducing a bioresponsive gatekeeper composed of negatively charged carboxylic groups and positively charged quaternary amine groups. When these Z-MSN encountered a mildly acidic environment, their surface charge readily switched from negative to positive by cleavage of an acid-labile maleic amide linkage, thus allowing for effective cellular uptake into tumor tissue. Doxorubicin (DOX) encapsulated in Z-MSN was not significantly released in physiological conditions (pH 7.4), whereas the release rate of DOX remarkably increased in mildly acidic conditions through disintegration of the gatekeeper. The antitumor efficacy of DOX-loaded Z-MSN (DOX-Z-MSN) was evaluated after their systemic administration to tumor-bearing mice. Compared to free DOX and DOX-loaded MSN without the gatekeeper, DOX-Z-MSN exhibited much higher antitumor efficacy in vivo. Overall, these results demonstrated that the hydrophilic negative surface of Z-MSN, with their closed gate, allowed for their effective accumulation in tumor tissue after systemic administration, and that their charge-swapping and gate-opening in the tumor environment enhanced their cellular uptake and drug release rate simultaneously, implying a highly promising potential for development of Z-MSN as a drug carrier for cancer therapy.

STATEMENT OF SIGNIFICANCE

In an attempt to address the issues of enhanced cellular uptake and site-specific drug release of nanoparticles, we herein report on zwitterionic MSN (Z-MSN) with a pH-responsive gatekeeper which can be internalized into cancer cells via switching their surface charge from negative, in physiological conditions, to positive, in the tumor microenvironment. We hypothesized that the hydrophilic negative surface of Z-MSN with a closed gate allows for their accumulation into tumor tissue after systemic administration, whereas their charge-swapping and gate-opening in the tumor environment enhance cellular uptake and drug release rate simultaneously. Overall, Z-MSN constitute a promising drug delivery carrier for cancer therapy.