Rare but Still There: An Interesting Case of Cytokeratin 20-Negative Merkel Cell Carcinoma.

Merkel cell carcinoma (MCC) of the skin is a rare and aggressive primary neuroendocrine tumor that mainly involves sun-exposed areas and can metastasize to other parts of the body. Due to varied clinical features and the sharing of similar histological features with other neuroendocrine tumors, diagnosis can be challenging. Therefore, immunohistochemistry plays an important role in diagnosis, and the characteristic perinuclear staining with cytokeratin 20 (CK 20) helps to differentiate it from other morphologically similar tumors, especially metastatic small cell carcinoma of the lung. We describe an interesting case of a 78-year-old female who was referred by a general practitioner (GP) with a few months' history of asymptomatic, rapidly enlarging, erythematous, nodular lesion on her left upper arm. Due to clinical findings and the location of the lesion on the sun-exposed area, wide differential diagnoses were considered. The lesion was excised for histological diagnosis. Surprisingly, morphological features favour the diagnosis of a neuroendocrine tumor. However, histological features including immunohistochemistry rendered it difficult to differentiate between primary cutaneous neuroendocrine carcinoma (Merkel cell CA) and metastatic small cell carcinoma of the lung due to the lack of specific and sensitive marker of CK 20 on immunohistochemistry. Subsequently, the patient had computer tomography of the chest/abdomen and pelvis (CTTAP) and positron emission tomography (PET) scans to rule out underlying primary malignancy. The case was also discussed at local and specialist skin multidisciplinary team meetings (MDT) including neuroendocrine MDT and a consensus diagnosis of Merkel cell carcinoma of the skin with negative CK 20 was established.

The Pressing Need to Raise Awareness about Osteoarthritis Care among Elderly Females in Pakistan: A Cross-sectional Study.

Introduction Osteoarthritis (OA) is the single-most common cause of physical disability among adults. In view of its promising management modalities, an analysis of the level of awareness among the suspected individuals and their attitudes is crucial to assess the level of their implementation. This study aimed to do that among the female population in Karachi, Pakistan. Methods This cross-sectional study was conducted among 316 elderly females (≥60 years) in Karachi in 2018. Data were collected via a structured questionnaire, which included sections titled: demographics, knowledge, attitudes, and practices. Data were analyzed using the Statistical Package for Social Sciences (version 20.20, IBM, Armonk, New York, US), and chi-square tests were used to assess the connection between OA care and socioeconomic statuses. Mean and standard deviation were calculated for quantitative variables. Results A considerable portion (48%, n = 152) of the participants were from a lower socioeconomic background, and 51% of them had a history of joint pain. Significantly, 63% of the participants (n = 199) attributed their joint pain to age, while nearly half attributed it to their diet and exercise habits. A major segment (73%, n = 230) of the participants, irrespective of their socioeconomic backgrounds, had visited a doctor for their joint complaints. Around 65% of the participants said they would never undergo a knee-joint replacement, regardless of how worse their symptoms might get. Additionally, 36% of the participants were unsatisfied with their current treatment, while more than half of the participants said that medication would improve their condition. Conclusions Our results demonstrate a connection between the lack of awareness about OA and the factors negatively affecting its management. They also point towards areas that require focused efforts for better awareness.

Experimental and computational surface hydrophobicity analysis of a non-enveloped virus and proteins.

The physical characteristics of viruses needs to be understood in order to manipulate the interaction of viruses with host cells, as well as to create specific molecular recognition techniques to detect, purify, and remove viruses. Viruses are generally believed to be positively charged at physiological pH, but there are few other defining characteristics. Here, we have experimentally and computationally demonstrated that a non-enveloped virus is more hydrophobic than a panel of model proteins. Reverse-phase and hydrophobic interaction chromatography and ANS fluorescence determined the experimental hydrophobic strength of each entity. Computational surface hydrophobicity was calculated by the solvent exposed surface area of the protein weighted by the hydrophobicity of each amino acid. The results obtained indicate a strong correlation between the computational surface hydrophobicity and experimentally determined hydrophobicity using reverse-phase chromatography and ANS fluorescence. The surface hydrophobicity did not compare strongly to the weighted average of the amino acid sequence hydrophobicity. This demonstrates that our simple method of calculating the surface hydrophobicity gives general hydrophobicity information about proteins and viruses with crystal structures. In the process, this method demonstrated that porcine parvovirus (PPV) is more hydrophobic than the model proteins used in this study. This adds an additional dimension to currently known virus characteristics and can improve our manipulation of viruses for gene therapy targeting, surface adsorption and general understanding of virus interactions.

Non-functional paraganglioma of the mediastinum.

Paragangliomas are rare tumours which have the ability to secrete neuropeptide and catecholamines. Frequently, the clinical presentation of these tumours is ill defined and some may have no symptoms whatsoever until the tumour is large enough to cause symptoms secondary to local invasion and mass effect, hence making paragangliomas a challenge to diagnose and manage surgically. We report a case of a 55 year old female who presented with shortness of breath and chest pain for 3 years. Further investigations led to the demonstration of a mass along the left side of the mediastinum which was suggestive of a neoplasm. Complete surgical resection of the tumour was achieved and the patient was discharged uneventfully.

Separation of porcine parvovirus from bovine serum albumin using PEG-salt aqueous two-phase system.

Vaccine production faces a challenge in adopting conventional downstream processing steps that can efficiently purify large viral particles. Some major issues that plague vaccine purification are purity, potency, and quality. The industry currently considers 30% as an acceptable virus recovery for a vaccine purification process, including all downstream processes, whereas antibody recovery from CHO cell culture is generally around 80-85%. A platform technology with an improved virus recovery would revolutionize vaccine production. In a quest to fulfill this goal, we have been exploring aqueous two-phase systems (ATPSs) as an optional mechanism to purify virus. ATPS has been unable to gain wide implementation mainly due to loss of virus infectivity, co-purification of proteins, and difficulty of polymer recycling. Non-enveloped viruses are chemically resistant enough to withstand the high polymer and salt concentrations that are required for effective ATPS separations. We used infectious porcine parvovirus (PPV), a non-enveloped, DNA virus as a model virus to test and develop an ATPS separation method. We successfully tackled two of the three main disadvantages of ATPS previously stated; we achieved a high infectious yield of 64% in a PEG-citrate ATPS process while separating out the main contaminate protein, bovine serum albumin (BSA). The most dominant forces in the separation were biomolecule charge, virus surface hydrophobicity, and the ATPS surface tension. Highly hydrophobic viruses are likely to benefit from the discovered ATPS for high-purity vaccine production and ease of implementation.