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R P Hoogma

Publications and source records attributed to R P Hoogma.

5 recordsLinked to original sources
PubMed1992

MRI screening of kindred at risk of developing paragangliomas: support for genomic imprinting in hereditary glomus tumours.

Paragangliomas of the head and neck (glomus tumours) can occur in a hereditary pattern and may be hormonally active as well as being associated with paragangliomas elsewhere. A number of these tumours may be present without symptoms. To detect the presence of subclinical paragangliomas we screened 83 members of a family at risk of developing hereditary paragangliomas using whole body MRI and urinary catecholamine testing. In eight previously diagnosed members, eight known glomus tumours of which one functioning, and two unknown glomus tumours and one unknown pheochromocytoma were present. Six unsuspected members showed ten glomus tumours and one pheochromocytoma. It has been suggested that the manifestation of hereditary glomus tumours is determined by the sex of the transmitting parent. There were no tumours in the descendants of female gene carriers. Comparing the likelihood of inheritance with genomic imprinting versus inheritance without genomic imprinting we found an odds ratio of 23375 in favour of genomic imprinting.

Carotid Body↗
PubMed1991

MR imaging and MIBG scintigraphy of pheochromocytomas and extraadrenal functioning paragangliomas.

To compare the potential of magnetic resonance (MR) imaging and scintigraphy performed with radiotracer-labeled metaiodobenzyl-guanidine (MIBG) in localization and characterization of functioning paragangliomas, the authors analyzed results of both modalities in 33 patients. Overall sensitivity for detection was 91% for MR imaging and 80% for MIBG scintigraphy. MR imaging demonstrated 100% of adrenal paragangliomas and 75% of extraadrenal paragangliomas, whereas MIBG scintigraphy revealed 75% and 88%, respectively. MIBG scintigraphy was more specific in the characterization of paragangliomas than MR imaging (100% vs 82%). However, MR imaging demonstrated nine other lesions not seen on scintigrams. On the basis of their results and other considerations, the authors believe MR imaging is the preferred initial technique when a functioning paraganglioma is suspected.

3-Iodobenzylguanidine↗
PubMed1990

Iodine-123-metaiodobenzylguanidine scintigraphy in patients with chemodectomas of the head and neck region.

While studying the uptake of iodine-123-metaiodobenzylguanidine ([123I]MIBG) in chemodectomas, we coincidentally detected catecholamine secreting tumors in 5 out of 14 patients. In three of these cases, a norepinephrine secreting abdominal paraganglioma was subsequently removed. One patient had a norepinephrine secreting chemodectoma and one had a dopamine secreting chemodectoma. Prior to [123I]MIBG imaging and urinary catecholamine measurements, endocrine activity was suspected in only one of these five patients. Apart from these five cases, two other patients showed elevated catecholamine secretion and abnormal abdominal [123I]MIBG concentrations. However, these two patients were not surgically explored, because of normal computed tomography (CT) and magnetic resonance (MRI) studies. We suspect that catecholamine-secreting tumors are more common in patients with chemodectomas than is assumed in the literature, and we therefore recommend urinary catecholamine screening for all patients with chemodectomas. In case of elevated catecholamine secretion, MIBG scintigraphy is indicated.

3-Iodobenzylguanidine↗
PubMed1983

Physiological effects of short-term treatment with enalapril in hypertensive patients.

To assess the effects of enalapril eight hospitalized hypertensive patients on constant sodium intake were treated with incremental doses of this angiotensin converting enzyme blocking drug. After four days of placebo treatment enalapril was given in single daily doses, starting with 1.25 mg and increasing until blood pressure was adequately controlled. On the 1.25 mg dose, angiotensin II (AII) and blood pressure did not change significantly, despite a 50% reduction in converting enzyme activity. There were, however, significant increases in noradrenaline, renin and aldosterone. With high doses a more pronounced reduction in converting enzyme activity was found while AII, aldosterone and blood pressure all fell significantly. Renin levels rose, but noradrenaline and adrenaline were reduced. Orthostatic hypotension did not occur. With continued treatment renal vascular resistance decreased concurrently with enhanced natriuresis and a reduction in body weight. Plasma volume rose slightly. The data indicate that enalapril may lower blood pressure by converting enzyme inhibition, but sodium loss and a decrease in sympathetic activity are associated features.

Adult↗