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1.
Cureus ; 16(2): e54446, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38510889

RESUMO

Gastrointestinal stromal tumors (GISTs) arise from the gastrointestinal tract. In rare cases, extra-gastrointestinal stromal tumors (EGISTs) occur in the omentum, mesentery, et cetera. They are mostly asymptomatic or have unspecific symptoms. Risk stratification classification systems are based on tumor size, mitotic rate, location, and perforation. The gold standard for diagnosis is a computed tomography (CT) scan. Ultrasound/CT-guided percutaneous biopsy allows histopathology and immunochemistry results (most stain positive for CD117 (c-KIT), CD34, and/or DOG1). Mutational analysis (most are in proto-oncogene c-KIT and platelet-derived growth factor receptor A (PDGFRA)) determines appropriate therapy. Surgical resection is the gold standard of treatment, with adjuvant and neoadjuvant molecular-targeted therapies depending on recurrence risk and mutations. This report describes a rare case of GIST (omentum EGIST) with a rare presentation (acute pyelonephritis) in a 67-year-old woman. Abdominal examination showed tenderness and a positive Murphy sign on the left side. Blood analysis presented microcytic hypochromic anemia, aggravated renal function, leukocytosis, and increased C-reactive protein. Abdominal CT revealed a heterogeneous abdominal mass, and a CT-guided biopsy showed epithelioid cells positive for CD117 and DOG1, which is compatible with a GIST. The patient underwent surgery that determined the GIST's origin from the greater omentum. Histology revealed an epithelioid GIST with large dimensions and a high histologic grade. Genetic testing detected a variant in the PDGFRA gene. With a high risk of progression, the patient received a three-year course of imatinib.

2.
Cureus ; 15(10): e47465, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38022206

RESUMO

Melanoma can spread to any organ of the body. The most affected sites are the skin and subcutaneous tissue, lymph nodes, lungs, liver, brain, bone, and intestine. Early diagnosis is crucial to prompt treatment. Although the incidence of melanoma is rising, novel treatment options are being developed, enabling a better prognosis. The authors present a rare case of metastatic melanoma affecting the muscle, lymph nodes, and subcutaneous tissue. The patient complained of redness and swelling of the right thigh and inguinal region, red, painful lumps on her chest wall, and pain in the left upper abdominal quadrant. A CT of the thorax, abdomen, and pelvis was performed, and surgical excision of the left thoracic mass led to the diagnosis of metastatic melanoma. However, no primary lesion was found despite extensive investigation. The unusual presentation of muscular metastasis heralds a poor prognosis. This case highlights the difficulty of diagnosing patients with rare presentations of a rather frequent disease.

4.
J Phys Chem A ; 115(30): 8392-8, 2011 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-21702490

RESUMO

An extensive photophysical characterization of 3-chloro-4-methylumbelliferone (3Cl4MU) in the ground-state, S(0), first excited singlet state, S(1), and lowest triplet state, T(1), was undertaken in water, neutral ethanol, acidified ethanol, and basified ethanol. Quantitative measurements of quantum yields (fluorescence, phosphorescence, intersystem crossing, internal conversion, and singlet oxygen formation) together with lifetimes were obtained at room and low temperature in water, dioxane/water mixtures, and alcohols. The different transient species were assigned and a general kinetic scheme is presented, summarizing the excited-state multiequilibria of 3Cl4MU. In water, the equilibrium is restricted to neutral (N*) and anionic (A*) species, both in the ground (pK(a) = 7.2) and first excited singlet states (pK(a)* = 0.5). In dioxane/water mixtures (pH ca. 6), substantial changes of the kinetics of the S(1) state were observed with the appearance of an additional tautomeric T* species. In low water content mixtures (mixture 9:1 v:v), only the neutral (N*) and tautomeric (T*) forms of 3Cl4MU are observed, whereas at higher water content mixtures (water mole fraction superior to 0.45), all three species N*, T*, and A* coexist in the excited state. In the triplet state, in the nonprotic and nonpolar solvent dioxane, the observed transient signals were assigned as the triplet-triplet transition of the neutral form, N*(T(1)) → N*(T(n)). In water, two transient species were observed and are assigned as the triplets of the neutral N*(T(1)) and the anionic form, A*(T(1)) (also obtained in basified ethanol). The phosphorescence spectra and decays of 3Cl4MU, in neutral, acidified, and basified solutions, demonstrate that only these two species N*(T(1)) and A*(T(1)) exist in the lowest lying triplet state, T(1). The radiative channel was found dominant for the deactivation of the anionic species, whereas with the neutral the S(1) ⇝ S(0) internal conversion competes with fluorescence. For both N* and A* the intersystem crossing yield represents a minor deactivation channel for S(1).


Assuntos
Himecromona/análogos & derivados , Teoria Quântica , Dioxanos/química , Himecromona/química , Estrutura Molecular , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Estereoisomerismo , Água/química
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