The Role of Neoadjuvant Therapy in a Giant Gastric Gastrointestinal Stromal Tumour: A Case Report and Review of the Literature.

Gastric gastrointestinal stromal tumour (GIST) is a rare disease with an annual incidence of 10 cases per million. Herein, we present the case of a 45-year-old man who visited our clinic with complaints of weight loss and anorexia, without changes in bowel habits or vomiting, for four months. On physical examination, all vital signs were normal. The abdomen was distended without tenderness and had a giant upper abdominal mass. Tumour marker investigation revealed high levels of cancer antigen 125 with normal levels of alpha-1-fetoprotein, carcinoembryonic antigen, and carbohydrate antigen. A computed tomography (CT) scan showed a mass measuring 35 × 25 × 20 cm, likely originating from the fundus of the stomach. Upper gastrointestinal endoscopy indicated external compression of the stomach and a fundal submucosal mass. Ultrasound-guided biopsy demonstrated the presence of a GIST. There was a severe danger of both the tumour rupturing during surgery and the combined excision of adjacent organs if the surgery was performed with the massive tumour. Therefore, daily neoadjuvant therapy with imatinib 400 mg was administered for three months. Post-therapeutic CT indicated a significant reduction in the size of the mass, which now measured 17 × 14 × 21 cm. The patient underwent surgical resection a month after the completion of neoadjuvant therapy, and the post-operative period was uneventful. He was followed up regularly at the general surgery department for 24 months without recurrence. This case asserts the benefit of neoadjuvant therapy in reducing the tumour size pre-operatively, which enhances the complete resection rate, prevents the need for multi-organ resection, and lowers the risk of surgery.

Pancreatic Arteriovenous Malformations: A Case From Saudi Arabia.

Arteriovenous malformation (AVM) of the gastrointestinal tract is a rare anomaly, mostly due to congenital reasons. Patients with pancreatic AVM can live without experiencing symptoms. It can present with gastrointestinal bleeding or portal hypertension, and diagnosis can be made by computed tomography (CT) or angiography. CT findings include multiple discrete intrapancreatic vessels. A 48-year-old man complained of abdominal pain with a sensation of fullness that radiated to the back for a month, associated with shortness of breath, loss of appetite, and unintentional weight loss of 33% in one month without nausea or vomiting. On physical examination, the abdomen was soft and lax with epigastric tenderness and a negative Murphy sign. Laboratory investigations showed high amylase with normal liver and kidney functions. CT showed pancreatic AVM. He underwent partial pancreatectomy and splenectomy. After the surgery, the patient reported an improvement in symptoms. All follow-up visits were uneventful. Pancreatic AVM is a rare disease, and the most significant chief complaint of most patients is gastrointestinal tract bleeding. It requires imaging depending on the signs and symptoms. The primary imaging modality is CT, with subtraction angiography for confirmation. Surgical treatment is the standard of management for most patients when tolerable. Additionally, early detection of these rare anomalies can avoid massive gastrointestinal tract bleeding and the development of resistance portal hypertension and can save patients' lives if bleeding occurs.

Mucinous Cystic Neoplasm of the Pancreas in a Pregnant Woman: A Case Report and Review of the Literature.

Mucinous cystic neoplasms of the pancreas are rare tumors that represent 10% of cystic pancreatic tumors. They are potentially sex hormone-sensitive. However, mucinous cystic neoplasms occurring during pregnancy are relatively uncommon. A 33-year-old woman in her ninth week of gestation was referred to us due to abdominal pain for two months. Magnetic resonance imaging revealed a well-defined unilocular cystic lesion at the tail of the pancreas, measuring 7x6.4 cm. The patient underwent tumor resection with distal pancreatectomy and splenectomy during the second trimester to prevent the potential risk of rupture of the neoplasm, rapid growth, and/or intrauterine growth restriction. Histopathological examination revealed a mucinous cystadenoma with no atypia or malignancy. The patient completely recovered from the surgery and had a healthy full-term baby. This case shows the benefit of performing the surgery during the second trimester compared to the potential risk of delaying the surgery.

Optimization of Mordenite Membranes Using Sucrose Precursor for Pervaporation of Water-Ethanol Mixtures.

Post-treated mordenite membranes were prepared using sucrose (C12H22O11) as a carbon precursor to block any pinholes and defects in the zeolite layer. The pervaporation (PV) process was used to separate ethanol from the water. The effects of the sucrose concentration and the pyrolysis temperature (650-850 °C) were investigated, and the resulting high separation performance compared to those post/pre-treated membranes was reported in the literature. In this study, mordenite carbon membranes yielded a water/ethanol separation factor of 990.37 at a water flux of 9.10 g/m2h. The influence of the operating temperature on the performance of the membrane also was considered. It was concluded that the selective adsorption of water through zeolite pores was achieved. The entire preparation procedure was achieved using a rapid, low-cost preparation process.

Minimizing Solvent Toxicity in Preparation of Polymeric Membranes for Gas Separation.

Toxic solvents such as dimethylformamide (DMF) are widely used for the preparation of polymeric membranes due to the strong dissolving power. Environmentally friendly solvents are available, but the developed membranes suffered from low performance due to the poor solubility of the polymer in the solvent. In this work, polyetherimide membranes were prepared using DMF with the addition of the biodegradable solvent γ-butyrolactone (GBL). Results show that mixing 75 wt % of DMF with 25 wt % GBL enhanced the membrane gas permeability toward hydrogen, methane, helium, carbon dioxide, and nitrogen. The overall permeability was increased by 9.6% compared to the permeability of the membrane made by 100 wt % DMF. Hydrogen-to-methane selectivity was also raised from 26.3 to 29.3.

Microscopy and Spectroscopy Techniques for Characterization of Polymeric Membranes.

Polymeric membrane is a proven technology for water purification and wastewater treatment. The membrane is also commercialized for gas separation, mainly for carbon dioxide removal and hydrogen recovery. Characterization techniques are excellent tools for exploring the membrane structure and the chemical properties. This information can be then optimized to improve the membrane for better performance. In this paper, characterization techniques for studying the physical structure such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM) are discussed. Techniques for investigating the crystal structure such as X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), and wide-angle X-ray scattering (WAXS) are also considered. Other tools for determining the functional groups such Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and nuclear magnetic resonance (NMR) are reviewed. Methods for determining the elemental composition such as energy-dispersion X-ray spectroscopy (EDS), X-ray fluorescent (XRF), and X-ray photoelectron spectroscopy (XPS) are explored. The paper also gives general guidelines for sample preparation and data interpretation for each characterization technique.

The Implementation of a Carbon Precursor to Produce ZSM-5 Membranes for the Separation of Isomers in the Pervaporation System.

The separation of p-xylene from its bulkier m-xylene and o-xylene is of great importance in the petrochemical industry. This paper presents the experimental results of the separation of xylene isomers using a zeolite carbon composite membrane in a pervaporation system. The preparation method involves the use of an inexpensive carbon precursor, sucrose, to avoid the lengthy conventional preparation methods used in the literature (e.g., hydrothermal synthesis). The composite membranes that were prepared exhibited a separation performance with a p-xylene/o-xylene separation factor of 5.35 and permeability of 76 g/m2 h for 95% o-xylene at 25 °C. The preparation procedure was designed from an economical perspective to facilitate any possible future commercialization.

The use of a sucrose precursor to prepare a carbon membrane for the separation of hydrogen from methane.

In this study, we present the use of sucrose (C12H22O11), which exists in abundance in nature, to prepare a carbon membrane without any preceding treatments. The preparation procedure was conducted using a low pyrolysis temperature, i.e., in the range of 300-500 °C, followed by complete formation of the structure of the carbon membrane. The gas separation characteristics of the resulting membranes were assessed by evaluating both hydrogen and methane permeation. The highest selectivity obtained for H2/CH4 was 31.34 with H2 permeability of 459.24 GPU. The entire fabrication procedure was designed to be economical in order to facilitate any future commercialization.

Preparation of polyetherimide membrane from non-toxic solvents for the separation of hydrogen from methane.

Polymeric membranes are usually prepared from solvents like n-methylpyrrolidone (NMP) because of the strong dissolving power and high boiling point. Yet, the solvent is costly, toxic and has environmental issues. In this work, nontoxic solvents such as methyl L-lactate, ethyl lactate, propylene carbonate, tributyl o-acetylcitrate, tributyl citrate, triethyl phosphate, and γ-butyrolactone (GBL) were introduced during membrane preparation. It was found that all the solvents were unable to dissolve polyetherimide except GBL. The membranes made by GBL and NMP were evaluated for gas separation, and they have almost similar hydrogen-to-methane selectivity, but, hydrogen permeance was better in NMP membranes.