A Case of Pheochromocytoma Presenting With Acute Coronary Syndrome.

Pheochromocytoma is a rare endocrine tumor originating from chromaffin cells of the adrenal medulla, which leads to the overproduction of catecholamines. Most symptoms, ranging from simple headaches to life-threatening cardiac arrests, are due to excess catecholamines. Usually, patients present with persistent or paroxysmal hypertension, headaches, sweating, and palpitations. Here, we describe a case that initially presented as an acute coronary syndrome and was treated accordingly. However, she had a history of nocturnal awakenings and panic attacks, which she had ignored for a month. On further evaluation, it turned out to be pheochromocytoma. This case report will surely help physicians better diagnose and treat such cases.

A Case of Pyrexia of Unknown Origin Diagnosed as Hemophagocytic Lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is a rare disease that is even rarer in the adult population. It requires a high degree of suspicion from the treating physician, and if diagnosed early, patients might have a survival benefit from this highly fatal condition. HLH is a disorder of immune regulation where the hyperactivity of cytokines attacks different cells, which leads to multiple organ dysfunctions. Varying presentations and similarities with other diseases make diagnosis difficult. Familial HLH is commonly seen in the pediatric population, while acquired or secondary HLH is seen in adults. Secondary HLH is commonly triggered by neoplasms, infections, rheumatological diseases, and other autoimmune diseases. Here is a case of HLH that presented as chronic undiagnosed fever. In this case report, we have discussed in detail this disease, its presentation, investigations, treatment, and other important information that will help practicing doctors better diagnose and treat HLH patients.

Osteomyelitis of the Clivus Secondary to Mucormycosis.

Osteomyelitis of the clivus secondary to mucormycosis is a rare infection of the clivus bone due to infiltration by fungi of the genus Mucor. Immunocompromised patients and/or those with diabetes mellitus are most at risk of developing this disease. Here, we present the case of a 63-year-old male patient with findings of gas within the clivus on computed tomography angiography. Diagnosis of mucormycosis osteomyelitis was confirmed after endoscopic biopsy and histopathologic examination. Furthermore, as this condition is very difficult to detect on imaging, we emphasize the discussion of typical radiology findings associated with this disease based on this and other case reports in the literature.

Immune Cell Modulation of the Extracellular Matrix Contributes to the Pathogenesis of Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy with a five-year survival rate of only 9%. PDAC is characterized by a dense, fibrotic stroma composed of extracellular matrix (ECM) proteins. This desmoplastic stroma is a hallmark of PDAC, representing a significant physical barrier that is immunosuppressive and obstructs penetration of cytotoxic chemotherapy agents into the tumor microenvironment (TME). Additionally, dense ECM promotes hypoxia, making tumor cells refractive to radiation therapy and alters their metabolism, thereby supporting proliferation and survival. In this review, we outline the significant contribution of fibrosis to the pathogenesis of pancreatic cancer, with a focus on the cross talk between immune cells and pancreatic stellate cells that contribute to ECM deposition. We emphasize the cellular mechanisms by which neutrophils and macrophages, specifically, modulate the ECM in favor of PDAC-progression. Furthermore, we investigate how activated stellate cells and ECM influence immune cells and promote immunosuppression in PDAC. Finally, we summarize therapeutic strategies that target the stroma and hinder immune cell promotion of fibrogenesis, which have unfortunately led to mixed results. An enhanced understanding of the complex interactions between the pancreatic tumor ECM and immune cells may uncover novel treatment strategies that are desperately needed for this devastating disease.

A Confirmation for the Positive Electric Charge of Bio-Molecular Motors through Utilizing a Novel Nano-Technology Approach In Vitro.

Molecular motors are microtubule-based proteins which contribute to many cell functions, such as intracellular transportation and cell division. The details of the nature of the mutual interactions between motors and microtubules still needs to be extensively explored. However, electrostatic interaction is known as one of the key factors making motor-microtubule association possible. The association rate of molecular motors to microtubules is a way to observe and evaluate the charge of the bio-motors in vivo. Growing evidence indicates that microtubules with distinct structural compositions in terms of beta tubulin isotypes carry different charges. Therefore, the electrostatic-driven association rate of motors-microtubules, which is a base for identifying the charge of motors, can be more likely influenced. Here, we present a novel method to experimentally confirm the charge of molecular motors in vitro. The offered nanotechnology-based approach can validate the charge of motors in the absence of any cellular components through the observation and analysis of the changes that biomolecular motors can cause on the dynamic of charged microspheres inside a uniform electric field produced by a microscope slide-based nanocapacitor. This new in vitro experimental method is significant as it minimizes the intracellular factors that may interfere the electric charge that molecular motors carry.

Portable Colorimetric Paper-Based Biosensing Device for the Assessment of Bisphenol A in Indoor Dust.

Bisphenol A (BPA) is found in polycarbonate plastic and epoxy resins and is used in a variety of commercial and consumer products. The leaching of BPA can result in human exposure via inhalation, ingestion, and dermal routes. As a result, humans have been exposed in their home and work environment to BPA. Conventional methods for BPA exposure assessment rely on cumbersome laboratory instrumentation with high capital and operational expenditures which limit the number of samples that can be analyzed. We report here the design of a compact portable colorimetric paper-based biosensing device with integrated sampling/analysis units for field-based measurements of BPA in indoor dust. The system employs interchangeable low-cost paper-based enzyme sensors as a test zone for BPA detection interfaced with an air-sampling cassette as a sample collection area. The sensor response was concentration-dependent with a detection limit of 0.28 µg/g. The sensor was validated with the conventional gas chromatography method and used to detect BPA exposure in household dust. BPA concentrations ranged from 0.05 to 3.87 µg/g in 57 household dust samples when both methods were used. The potential of this method for field measurements of dust samples is discussed.

Comparative evaluation of intestinal nitric oxide in embryonic zebrafish exposed to metal oxide nanoparticles.

Nanoparticle (NP) exposure may induce oxidative stress through generation of reactive oxygen and nitrogen species, which can lead to cellular and tissue damage. The digestive system is one of the initial organs affected by NP exposure. Here, it is demonstrated that exposure to metal oxide NPs induces differential changes in zebrafish intestinal NO concentrations. Intestinal NO concentrations are quantified electrochemically with a carbon fiber microelectrode inserted in the intestine of live embryos. Specificity of the electrochemical signals is demonstrated by NO-specific pharmacological manipulations and the results are correlated with the 4,5-diaminofluorescein-diacetate (DAF-FM-DA). NPs are demonstrated to either induce or reduce physiological NO levels depending on their redox reactivity, type and dose. NO level is altered following exposure of zebrafish embryos to CuO and CeO2 NPs at various stages and concentrations. CuO NPs increase NO concentration, suggesting an intestinal oxidative damage. In contrast, low CeO2 NP concentration exposure significantly reduces NO levels, suggesting NO scavenging activity. However, high concentration exposure results in increased NO. Alterations in NO concentration suggest changes in intestinal physiology and oxidative stress, which will ultimately correspond to NPs toxicity. This work also demonstrates the use of electrochemistry to monitor in vivo changes of NO within zebrafish organs.

Colorimetric paper bioassay for the detection of phenolic compounds.

A new type of paper based bioassay for the colorimetric detection of phenolic compounds including phenol, bisphenol A, catechol and cresols is reported. The sensor is based on a layer-by-layer (LbL) assembly approach formed by alternatively depositing layers of chitosan and alginate polyelectrolytes onto filter paper and physically entrapping the tyrosinase enzyme in between these layers. The sensor response is quantified as a color change resulting from the specific binding of the enzymatically generated quinone to the multilayers of immobilized chitosan on the paper. The color change can be quantified with the naked eye but a digitalized picture can also be used to provide more sensitive comparison to a calibrated color scheme. The sensor was optimized with respect to the number of layers, pH, enzyme, chitosan and alginate amounts. The colorimetric response was concentration dependent, with a detection limit of 0.86 (±0.1) µg/L for each of the phenolic compounds tested. The response time required for the sensor to reach steady-state color varied between 6 and 17 min depending on the phenolic substrate. The sensor showed excellent storage stability at room temperature for several months (92% residual activity after 260 days storage) and demonstrated good functionality in real environmental samples. A procedure to mass-produce the bioactive sensors by inkjet printing the LbL layers of polyelectrolyte and enzyme on paper is demonstrated.

Enzyme functionalized nanoparticles for electrochemical biosensors: a comparative study with applications for the detection of bisphenol A.

We developed electrochemical biosensors based on enzyme functionalized nanoparticles of different compositions for the detection of bisphenol A. We utilized for the first time magnetic nickel nanoparticles as an enzyme immobilization platform and electrode material to construct screen-printing enzyme biosensors for bisphenol A. We compared the analytical performance of these sensors with those based on iron oxide (Fe(3)O(4)) and gold nanoparticles. The proposed biosensor format exhibited fast and sensitive amperometric responses to bisphenol A with a response time of less then 30s. Among the three configurations, nickel provided comparable or better characteristics in terms of detection limit and sensitivity than Fe(3)O(4) and gold nanoparticles. The biosensors were characterized by good reproducibility, stability of more than 100 assays (residual activity for nickel was 98%) and a wide linear range which spanned from 9.1 × 10(-7) to 4.8 × 10(-5)M for nickel, 2.2 × 10(-8) to 4.0 × 10(-5)M for Fe(3)O(4) and 4.2 × 10(-8) to 3.6 × 10(-5)M for gold. The highest sensitivity was obtained with nickel. The detection limits for the three types of biosensors were: 7.1 × 10(-9), 8.3 × 10(-9) and 1 × 10(-8)M for nickel, Fe(3)O(4) and gold nanoparticles in that order, respectively. These results demonstrate that nickel nanoparticles can be successfully used in the construction of electrochemical enzyme sensors for the detection of phenolic compounds.

A case report on bezoar.

A nine years old girl was admitted into the paediatric surgery word of Dhaka Medical College Hospital (DMCH) with upper abdominal mass and discomfort, was diagnosed radiologically as a case of gastric bezoar which was further confirmed by endoscopy as trichobezoar (hair ball). The girl was undergone laparotomy and trichobezoar was removed from stomach by gastrostomy. After ten days of operation she became well and was discharged from the hospital.