Merkel cell carcinoma

Merkel cell carcinoma (MCC) of the skin is a rare, aggressive form of skin cancer that metastasizes to other parts of the body. This cutaneous neuroendocrine tumour mainly affects older people, with most cases generally occurring over the age of 50 years. Merkel cell polyomavirus has been shown to induce gene mutations resulting in this skin cancer, with immunosuppression and ultraviolet radiation being other key risk factors in its pathogenesis. MCC is clinically seen as a rapidly enlarging, isolated, irregular erythematous nodule typically found on sun-exposed sites. Diagnosis is through clinical examination followed by tissue biopsy, which demonstrates characteristic histopathological neuroendocrine features. Immunohistochemistry plays a crucial role in diagnosis with the characteristic perinuclear staining with cytokeratin-20 helping to differentiate it from other morphologically similar tumours. Sentinel lymph node biopsy and imaging is essential for staging and determining prognosis. Surgical excision is the mainstay of treatment for localized disease although adjuvant radiotherapy is often required. Metastatic disease involves a very poor prognosis, and immune checkpoint inhibitors have recently shown promise in the treatment of metastatic disease. Avelumab, a monoclonal antibody that binds to the programmed death-1 receptor, has been approved by the National Institute for Health and Care Excellence and shown encouraging survival outcomes. It provides an option for treating metastatic carcinoma in adults after they have failed ≥ 1 line of chemotherapy for metastatic disease.

Acute Rheumatic Fever Presenting as a Mimicker of Septic Arthritis

Acute rheumatic fever (ARF) describes the non-suppurative and autoimmune inflammation of joint, muscle, and fibrous tissue that occurs after group A streptococcal (GAS) pharyngitis. This report describes a rare case of a 39-year-old male with migratory arthralgias as a presenting sign of ARF. Through this case, we review the current literature on ARF and highlight clinical and objective findings that differentiate ARF from similar presenting arthralgias, specifically post-streptococcal reactive arthritis (PSRA). With this report, we hope to increase clinical suspicion for ARF in patients with acute joint pain, as differentiating ARF from other arthritides, PSRA specifically, determines management strategy and need for secondary prophylaxis against rheumatic heart disease.

Double valve involvement: papillary fibroelastoma in a patient with severe mitral and aortic valve regurgitation

Cardiac papillary fibroelastoma is a benign neoplasm that arises in the endocardium. It commonly presents as an incidental finding on transthoracic echocardiography or as emboli to the coronary, cerebral or pulmonary vasculature. Clinical manifestations described in the literature have generally been related to a sequelae of the associated embolic phenomenon of these lesions. Valve regurgitation is less common with papillary fibroelastoma and when found, it is not known to cause severe regurgitation requiring valve replacement. We report a case of papillary fibroelastoma in a patient with severe mitral and aortic valve regurgitation in association with mobile masses requiring double valve replacement. This patient managed initially as infective endocarditis with severe double valve regurgitation, was found to have valvular masses concernng for papillary fibroelastoma and subsequently confirmed on pathology.

Bacterial count and predisposing factors of Clostridium perfringens (targeting CPA gene) infection along with antimicrobial sensitivity in diarrheic sheep in Pakistan

Clostridium perfringens (C. perfringens) is a normal inhabitant in the gut of animals. It may proliferate rapidly in favorable conditions and produces lethal toxins. These toxins may cause lethal effects in the intestines and systemically it may cause enterotoxaemia. In disease conditions, the presence of C. perfringens CFU/g in fecal sample can be of diagnostic value. This study aims to determine the bacterial counts and predisposing factors of C. perfringens (targeting CPA gene) infection in addition to an in-vitro antimicrobial trial in entero-toxemic sheep in Pakistan. A total of 192 diarrheic sheep irrespective of age, gender and breed were selected and the CFU/g was determined from the fecal samples. The study showed that 34.9% of the samples had elevated level of bacterial count compared to the normal (10⁴-10⁷ CFU/g). Out of the total, 7.8% of the samples had subnormal bacterial count (CFU/g), while, 57.3% of the samples showed bacterial counts in the normal ranges. The confirmation of selectively isolated C. perfringens was done by amplification of 324bp CPA gene fragment using polymerase chain reaction (PCR). The in-vitro antimicrobial sensitivity trials showed that penicillin, ciprofloxacin and ceftriaxone are 100% efficacious against C. perfringens, while, bacitracin, ampicillin and amoxicillin were found to be least effective. The key determinants in this study which support the in-vivo growths of C. perfringens were; carbohydrate rich diet and overcrowding with the odds ratios (OR) of 5.44 and 2.26, respectively. This study concludes that C. perfringens is highly prevalent in sheep population of Pakistan. The incidence of enterotoxaemia can be minimized by controlling the factors which enhance its in-vivo growth. The diseased animal associated with elevated C. perfringens levels can be effectively cured using any one of the penicillin, ciprofloxacin and ceftriaxone.

Enteroinsular hormones in two siblings with Donohue syndrome and complete leptin deficiency

The main biochemical hallmark of the rare and lethal condition of Donohue syndrome (DS) is hyperinsulinemia. The roles of the gut and other pancreatic hormones involved in glucose metabolism, satiety and energy expenditure have not been previously reported in DS. Two siblings with genetically confirmed DS and extremely low weight underwent a mixed meal (MM) test where pancreatic hormones insulin, C-peptide, glucagon, active amylin, pancreatic polypeptide (PP) as well as gut hormones active glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), ghrelin, peptide YY (PYY) and leptin were analyzed using a Multiplex assay. Results were compared to those of 2 pediatric controls. As expected, concentrations of insulin, C-peptide and amylin were very high in DS cases. The serum glucagon concentration was undetectable at the time of hypoglycemia. GIPs concentrations were lower in the DS, however, this was not mimicked by the other incretin, GLP-1. Ghrelin concentrations were mainly undetectable (<13.7 pg/mL) in all participants. DS cases had higher PYY and dampened PP concentrations. Leptin levels remained completely undetectable (<137.0 pg/mL). Patients with DS have extremely high amylin levels, completely undetectable serum glucagon and leptin levels with abnormal satiety regulating hormone PP with a relatively normal ghrelin response during a MM test. The low serum GIP might be acting as physiological brake on insulin secretion. The undetectable serum leptin levels suggest the potential of using leptin analogues as therapy for DS patients.

An exploratory, open-label, randomized, multicenter study to investigate the pharmacodynamics of a glycoengineered antibody (imgatuzumab) and cetuximab in patients with operable head and neck squamous cell carcinoma

BACKGROUND

In addition to inhibiting epidermal growth factor receptor (EGFR) signaling, anti-EGFR antibodies of the IgG1 'subtype' can induce a complementary therapeutic effect through the induction of antibody-dependent cell-mediated cytotoxicity (ADCC). Glycoengineering of therapeutic antibodies increases the affinity for the Fc-gamma receptor, thereby enhancing ADCC.

PATIENTS AND METHODS

We investigated the changes in immune effector cells and EGFR pathway biomarkers in 44 patients with operable, advanced stage head and neck squamous cell carcinoma treated with two preoperative doses of either glycoengineered imgatuzumab (GA201; 700 or 1400 mg) or cetuximab (standard dosing) in a neoadjuvant setting with paired pre- and post-treatment tumor biopsies.

RESULTS

Significant antitumor activity was observed with both antibodies after just two infusions. Metabolic responses were seen in 23 (59.0%) patients overall. One imgatuzumab-treated patient (700 mg) achieved a 'pathological' complete response. An immediate and sustained decrease in peripheral natural killer cells was consistently observed with the first imgatuzumab infusion but not with cetuximab. The functionality of the remaining peripheral natural killer cells was maintained. Similarly, a pronounced increase in circulating cytokines was seen following the first infusion of imgatuzumab but not cetuximab. Overall, tumor-infiltrating CD3+ cell counts increased following treatment with both antibodies. A significant increase from baseline in CD3+/perforin+ cytotoxic T cells occurred only in the 700-mg imgatuzumab group (median 95% increase, P < 0.05). The most prominent decrease of EGFR-expressing cells was recorded after treatment with imgatuzumab (700 mg, -34.6%; 1400 mg, -41.8%). The post-treatment inflammatory tumor microenvironment was strongly related to baseline tumor-infiltrating immune cell density, and baseline levels of EGFR and pERK in tumor cells most strongly predicted therapeutic response.

CONCLUSIONS

These pharmacodynamic observations and relationship with efficacy are consistent with the proposed mode of action of imgatuzumab combining efficient EGFR pathway inhibition with ADCC-related immune antitumor effects.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01046266 (ClinicalTrials.gov).

Genetic barcoding and phylogenetic analysis of dusky cotton bug (Oxycarenus hyalinipennis) using mitochondrial cytochrome c oxidase I gene

Cotton dusky bug (Oxycarenus spp.) mostly attack on cash crops such as Gossypium, Cola and Hibiscus which affect the national economy therefore sustainable pest management is needed. Cytochrome c oxidase I (COI) gene is utilized as marker gene for DNA barcoding, genetic and ecological study of insects. In present study insect (cotton dusky bug) samples were collected from cotton fields in Faisalabad. COI gene was amplified from genomic DNA of bug and cloned into pTZ57R/T vector (Fermentas). The clone was sent to Macrogen (South Korea) for Sanger sequencing. The phylogenetic analysis and pairwise multiple sequence alignment showed that our cotton dusky bug grouped with two species of Oxycarenus genus and highest sequence identity was 91.1% with Oxycarenus hylinipennis. This is the first report of genetic barcode of Oxycarenus hylinipennis from cotton from Pakistan.

A CACNA1D mutation in a patient with persistent hyperinsulinaemic hypoglycaemia, heart defects, and severe hypotonia

Congenital hyperinsulinaemic hypoglycaemia (HH) can occur in isolation or it may present as part of a wider syndrome. For approximately 40%-50% of individuals with this condition, sequence analysis of the known HH genes identifies a causative mutation. Identifying the underlying genetic aetiology in the remaining cases is important as a genetic diagnosis will inform on recurrence risk, may guide medical management and will provide valuable insights into β-cell physiology. We sequenced the exome of a child with persistent diazoxide-responsive HH, mild aortic insufficiency, severe hypotonia, and developmental delay as well as the unaffected parents. This analysis identified a de novo mutation, p.G403D, in the proband's CACNA1D gene. CACNA1D encodes the main L-type voltage-gated calcium channel in the pancreatic β-cell, a key component of the insulin secretion pathway. The p.G403D mutation had been reported previously as an activating mutation in an individual with primary hyper-aldosteronism, neuromuscular abnormalities, and transient hypoglycaemia. Sequence analysis of the CACNA1D gene in 60 further cases with HH did not identify a pathogenic mutation. Identification of an activating CACNA1D mutation in a second patient with congenital HH confirms the aetiological role of CACNA1D mutations in this disorder. A genetic diagnosis is important as treatment with a calcium channel blocker may be an option for the medical management of this patient.

Development of new UV-vis spectroscopic microwave-assisted method for determination of glucose in pharmaceutical samples

A new UV-Visible spectroscopic method assisted with microwave for the determination of glucose in pharmaceutical formulations was developed. In this study glucose solutions were oxidized by ammonium molybdate in the presence of microwave energy and reacted with aniline to produce a colored solution. Optimum conditions of the reaction including wavelength, temperature, and pH of the medium and relative concentration ratio of the reactants were investigated. It was found that the optimal wavelength for the reaction is 610 nm, the optimal reaction time is 80s, the optimal reaction temperature is 160°C, the optimal reaction pH is 4, and the optimal concentration ratio aniline/ammonium molybdate solution was found to be 1:1. The limits of detection and quantification of the method are 0.82 and 2.75 ppm for glucose solution, respectively. The use of microwaves improved the speed of the method while the use of aniline improved the sensitivity of the method by shifting the wavelength.