Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P41181 (collecting duct)
 5,183 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hyponatremia, a common electrolyte abnormality in oncology practice, may be a negative prognostic factor in cancer patients based on a systematic analysis of published studies. The largest body of evidence comes from small-cell lung cancer (SCLC), for which hyponatremia was identified as an independent risk factor for poor outcome in six of 13 studies. Hyponatremia in the cancer patient is usually caused by the syndrome of inappropriate antidiuretic hormone (SIADH), which develops more frequently with SCLC than with other malignancies. SIADH may be driven by ectopic production of arginine vasopressin (AVP) by tumors or by effects of anticancer and palliative medications on AVP production or action. Other factors may cause hypovolemic hyponatremia, including diarrhea and vomiting caused by cancer therapy. Hyponatremia may be detected on routine laboratory testing before or during cancer treatment or may be suggested by the presence of mostly neurological symptoms. Treatment depends on several factors, including symptom severity, onset timing, and extracellular volume status. Appropriate diagnosis is important because treatment differs by etiology, and choosing the wrong approach can worsen the electrolyte abnormality. When hyponatremia is caused by SIADH, hypertonic saline is indicated for acute, symptomatic cases, whereas fluid restriction is recommended to achieve a slower rate of correction for chronic asymptomatic hyponatremia. Pharmacological therapy may be necessary when fluid restriction is insufficient. The orally active, selective AVP receptor 2 (V(2))-receptor antagonist tolvaptan provides a mechanism-based option for correcting hyponatremia caused by SIADH or other conditions with inappropriate AVP elevations. By blocking AVP effects in the renal collecting duct, tolvaptan promotes aquaresis, leading to a controlled increase in serum sodium levels.
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PMID:Diagnosis and management of hyponatremia in cancer patients. 2261 70

A 57-year-old Japanese man visited our hospital with a moist cough. Chest radiographic imaging showed a left hilar shadow. Adenocarcinoma cells were found on cytologic screening of fresh sputum. Although multiple metastases including brain were detected, no tumor was observed in the kidneys. The patient underwent whole-brain irradiation and chemotherapy for advanced-stage lung cancer. One month before his death, carcinomatous meningitis was detected. Hyponatremia, hypo-osmolality, and hypertonic urine suggested the syndrome of inappropriate antidiuresis. Restricting water intake improved the hyponatremia; however, he developed fever and hematuria. Despite systemic administration of an antibacterial drug, he died. Primary tumor in the lung was absent, but adenocarcinoma of the right kidney was evident on autopsy. Lectin histochemical analysis of the carcinoma revealed its distal nephron origin, confirming collecting duct carcinoma. Severe carcinomatous meningitis, which is possibly caused the syndrome of inappropriate antidiuresis, was observed, with no cancer involvement of the pituitary gland and hypothalamus.
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PMID:Collecting duct renal cell carcinoma with the syndrome of inappropriate antidiuresis: an autopsy case report. 2392 58