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Biomedical subjects

P B Tan

Publications and source records attributed to P B Tan.

7 recordsLinked to original sources
PubMed1999

Signaling specificity: the RTK/RAS/MAP kinase pathway in metazoans.

The molecular basis by which commonly used signaling pathways are able to elicit tissue-specific responses in multicellular organisms is an important yet poorly understood problem. In this review, we use the receptor tyrosine kinase (RTK)/RAS/MAP kinase signaling cascade as a model to discuss various hypotheses that have been proposed to explain signaling specificity. Specificity can arise at the level of the receptor, through the modulation of signaling kinetics, through the interaction of different signaling pathways, and at the level of downstream signaling components. Mechanisms of specificity used by the RTK/RAS/MAP kinase signaling pathway might apply to other signaling pathways as well, and might help explain how multicellular organisms are able to generate tissues of diverse forms and functions from a small set of common signaling pathways.

Animals↗
PubMed1998

MAP kinase signaling specificity mediated by the LIN-1 Ets/LIN-31 WH transcription factor complex during C. elegans vulval induction.

The let-23 receptor/mpk-1 MAP kinase signaling pathway induces the vulva in C. elegans. We show that MPK-1 directly regulates both the LIN-31 winged-helix and the LIN-1 Ets transcription factors to specify the vulval cell fate. lin-31 and lin-1 act genetically downstream of mpk-1, and both proteins can be directly phosphorylated by MAP kinase. LIN-31 binds to LIN-1, and the LIN-1/LIN-31 complex inhibits vulval induction. Phosphorylation of LIN-31 by MPK-1 disrupts the LIN-1/LIN-31 complex, relieving vulval inhibition. Phosphorylated LIN-31 may also act as a transcriptional activator, promoting vulval cell fates. LIN-31 is a vulval-specific effector of MPK-1, while LIN-1 acts as a general effector. The partnership of tissue-specific and general effectors may confer specificity onto commonly used signaling pathways, creating distinct tissue-specific outcomes.

3T3 Cells↗
PubMed1997

[Pheochromocytoma as a cause of collapse and hypertension during a stay in the tropics].

Two male patients aged 47 and 26 ears had long-standing, slowly progressive complaints of sudden headache, nausea, vomiting and faintness. Their symptoms grew much worse during an active holiday in the tropics. Phaeochromocytoma was diagnosed. After resection the complaints resolved. A slumbering phaeochromocytoma may become manifest due to increased vasodilation and exertion during a temporary stay in the tropics.

Adrenal Gland Neoplasms↗
PubMed1989

A remarkable subhepatic tumour.

Although foreign-body pseudotumours are not particularly rare, the diagnosis is not often considered. The case history is presented of a patient with a surgical gauze left after a cholecystectomy performed 23 years before. The incidence of these pseudotumours and the variety of clinical pictures in relation to the condition are described.

Abdominal Pain↗