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Biomedical subjects

Luis Teixeira

Publications and source records attributed to Luis Teixeira.

8 recordsLinked to original sources
PubMed2006

Kallmann syndrome: mutations in the genes encoding prokineticin-2 and prokineticin receptor-2.

Kallmann syndrome combines anosmia, related to defective olfactory bulb morphogenesis, and hypogonadism due to gonadotropin-releasing hormone deficiency. Loss-of-function mutations in KAL1 and FGFR1 underlie the X chromosome-linked form and an autosomal dominant form of the disease, respectively. Mutations in these genes, however, only account for approximately 20% of all Kallmann syndrome cases. In a cohort of 192 patients we took a candidate gene strategy and identified ten and four different point mutations in the genes encoding the G protein-coupled prokineticin receptor-2 (PROKR2) and one of its ligands, prokineticin-2 (PROK2), respectively. The mutations in PROK2 were detected in the heterozygous state, whereas PROKR2 mutations were found in the heterozygous, homozygous, or compound heterozygous state. In addition, one of the patients heterozygous for a PROKR2 mutation was also carrying a missense mutation in KAL1, thus indicating a possible digenic inheritance of the disease in this individual. These findings reveal that insufficient prokineticin-signaling through PROKR2 leads to abnormal development of the olfactory system and reproductive axis in man. They also shed new light on the complex genetic transmission of Kallmann syndrome.

Chromosome Segregation↗
PubMed2006

[Scleroderma renal crisis].

Scleroderma renal crisis (SRC) occurs in patients with systemic sclerosis (SSc) and is defined by otherwise unexplained rapidly progressive renal insufficiency associated with oliguria or rapidly progressive arterial hypertension or both. SRC is a rare and severe complication of SSc, most often encountered during the first 4 years of disease, almost only in patients with diffuse SSc. Factors predicting SRC were identified, including high-dose corticosteroid administration. Use of angiotensin-converting enzyme inhibitors (ACEI) has dramatically impressed the prognosis of SRC, but it mortality rate is still high. Treatment aims at normalizing blood pressure as soon as possible. ACEI should always be used, and additional anti-hypertensive agents, including calcium channel blockers and alpha- and beta-blockers, may be useful. Renal replacement therapy may be needed, but often (for almost half of patients) only temporarily.

Acute Kidney Injury↗
PubMed2004

[Malignant cardiac tumors].

Cardiac neoplasms are a rare occurrence in clinical practice. The various frequencies of primary and secondary malignant tumors vary from report to report, approximately 1% in most autopsy series and 4% in cancer patient's autopsies. Cardiac malignancies account for less 1% of cardiac surgery and about for 0.1% of cardiac echographic studies. The presence of metastatic tumor to the heart usually indicates widespread metastases. Lung carcinomas are the most commonly encountered tumor followed by breast and pancreas cancer and melanoma. Apart from primary pericardial mesothelioma, primary cardiac tumors are high-grade sarcomas with a high metastatic potency that often becomes evident early after surgery. Symptoms are non specific, occur late in the disease and affect few patients; especially secondary neoplasms of the heart take their course so fast that they cannot become symptomatic. The signs of cardiac neoplasms are divided into systemic symptoms (fever, arthralgias and myalgias), cardiac symptoms (congestive heart failure, arrhythmia, chest pain) and uncommon embolisms. Diagnosis is actually made easier with cardiac echography. Cardiac RMI is helpful to estimate vessels and pericardium involvement. Due to its poor prognosis, treatment of cardiac metastases is restricted to best supportive care. For primary cardiac neoplasms, surgery must be carefully discussed because operative intervention is often followed by rapid widespread metastases that adjuvant chemotherapy cannot avoid in most cases.

Heart Neoplasms↗
PubMed2004

[Cardiotoxicity of 5-fluorouracil].

5-fluorouracil (5FU) is a largely employed antimetabolite, responsible for several well-known toxicities like hand-foot syndrome, diarrhoea, mucositis or leucopenia. Cardiotoxicity of 5-FU is known but uncommon and usually not life-threatening. The incidence has varied from 1.5 and 18%. The physiopathology is controversial, although more recent data suggest a myocardial toxicity. Clinical presentation include chest-pain, cardiac arrythmia, myocardial infarction or global cardiac failure. Electrocardiographic features are usually aspecific, with ischemic signs. The main treatment is to stop the 5-FU infusion and to introduce symptomatic cardiologic treatment. Although the prognosis is good, the mortality ranges between 2.2 and 13% in case of symptomatic cardiotoxicity. Secondary prophylaxis remains controversial.

Antimetabolites, Antineoplastic↗
PubMed2003

Genome-wide analysis of nuclear mRNA export pathways in Drosophila.

NXF1, p15 and UAP56 are essential nuclear mRNA export factors. The fraction of mRNAs exported by these proteins or via alternative pathways is unknown. We have analyzed the relative abundance of nearly half of the Drosophila transcriptome in the cytoplasm of cells treated with the CRM1 inhibitor leptomycin-B (LMB) or depleted of export factors by RNA interference. While the vast majority of mRNAs were unaffected by LMB, the levels of most mRNAs were significantly reduced in cells depleted of NXF1, p15 or UAP56. The striking similarities of the mRNA expression profiles in NXF1, p15 and UAP56 knockdowns show that these proteins act in the same pathway. The broad effect on mRNA levels observed in these cells indicates that the functioning of this pathway is required for export of most mRNAs. Nonetheless, a set of mRNAs whose export was unaffected by the depletions and some requiring NXF1:p15 but not UAP56 were identified. In addition, our analysis revealed a feedback loop by which a block to mRNA export triggers the upregulation of genes involved in this process.

Active Transport, Cell Nucleus↗