Uptake of iodine-123 MIBG by pheochromocytomas, paragangliomas, and neuroblastomas: a histopathological comparison

The percentage uptake of [123I]metaiodobenzylguanidine (MIBG) by tumors of the paraganglion system is compared with the number of neurosecretory granules (assessed by both light and electron microscopy) in the subsequently resected tumors in six patients. Iodine-123 MIBG was injected intravenously; the tumor uptake of [123I]MIBG varied between 0.001% and 0.14% of the injected dose per gram of tumor tissue at 22 hr. The number of neurosecretory granules in tissue sections was scored on a scale of I-III. A direct proportional correlation was found between the percentage uptake of [123I]MIBG by the tumor and the number of neurosecretory granules in the tissue sections but not with plasma or urinary catecholamines. This technique for imaging reflects the storage status of the tumor better than plasma and urinary catecholamine measurements.     

Interaction between endogenous opioids, cholinergic and adrenergic mechanisms during vagally-induced gastrin release in rats

Endogenous opioids are present in neurons of the vagus and the intrinsic nervous system and they are colocalized with gastrin in antral G-cells. This raises the possibility that endogenous opioids modulate gastrin release. Stimulation of both cervical vagi (10V, 5Hz, 5ms) elicited an increase of arterial plasma gastrin levels at intragastric pH7 or pH2. The response at pH2 was 30% of that at luminal pH7. Atropine reduced vagally stimulated gastrin levels substantially. At luminal pH2 the small residual noncholinergic response was mediated neither by adrenergic mechanisms nor by endogenous opioids. At luminal pH 7 adrenergic blockade with phentolamine and propranolol reduced vagally stimulated gastrin by 60%. In the presence of atropine adrenergic blockade elicited only a small inhibitory effect suggesting that vagal activation of adrenergic mechanisms depends on atropine-sensitive cholinergic pathways. Blockade of opiate receptors by naloxone had no effect on vagal gastrin release, however, the noncholinergic gastrin response was reduced significantly by naloxone, suggesting that cholinergic mechanisms normally restrain activation of endogenous opioids during vagal stimulation. Naloxone had no effect on the noncholinergic, nonadrenergic stimulation of gastrin levels. These data suggest that endogenous opioids can contribute to vagal gastrin release provided the cholinergic restraint is blocked and adrenergic mechanisms stimulate endogenous opioids. In conclusion a major role of endogenous opioids in the regulation of vagal gastrin release can not be detected.     

Neuroblastoma: the role of MR imaging

Thirty-five MR examinations were performed in 17 children with neuroblastoma during the course of their diagnostic evaluation and treatment. Findings were confirmed by correlation with the results of other imaging techniques, biopsies, and surgical and autopsy findings. MR accurately detected the lesions and their extent in all patients. It correctly evaluated the possibility of resectability and showed metastases, response to treatment and development of complications. MR appears to be a reliable technique for the diagnosis, staging, and follow-up of children with neuroblastoma.     

Classification of progressive systemic scleroderma

A new classification of forms of progressive systemic scleroderma (PSS) is presented. Compared with previous classifications, it includes not only frequent, typical forms of PSS, but also rarer manifestations. For the first time, it considers pathogenetic factors, such as the phenomena which have become known concerning the immunological system, and distinguishes between noninflammatory and inflammatory subtypes. Etiological (in this case, immunogenetic) criteria are also considered. This classification is open to further differentiation and development.     

(E)-5-(2-bromovinyl)-2'-desoxyuridine--a new nucleoside analog with selective inhibitory action against herpesviruses. Studies in cell culture and animal experiments

(E)-5-(2-Bromovinyl)-2'-deoxyuridine (1; BrVUdR) inhibits the replication of herpes simplex virus type 1 (HSV-1) and of varicella-zoster virus (VZV) in vitro at concentrations of 0.01 to 0.23 mumol/l, whereas herpes simplex virus type 2 (HSV-2) is influenced only at 5.5 to 27 mumol/l. In comparison to some classical and newly developed antiherpetics, i. e. 5-iodo-2'-desoxyuridine (2; idoxuridine, IDU), 9-beta-D-arabinofuranosyladenine (4; vidarabine Ara-A), 9-(2-hydroxyethoxymethyl) guanine (5; acyclovir, ACV) and 2'-fluoro-5-iodo-1-beta-D-aracytosine (6;FIAC) the following order of decreasing activity was found:1 greater than 6 greater than 5 greater than 2 greater than 4 (against HSV-1) and 6 greater than 2 greater than 5 greater than 1 greater than 4 (against HSV-2). The high selectivity of the antiviral effect of BrVUdR towards HSV-1 and TZV is based on the fact, that proliferation of different mammalian cell lines is inhibited by 50% only at concentrations as high as 90 to 170 mumol/l, resulting in a therapeutical index of 1000 to 10,000. Successful treatment of an HSV-1 encephalitis in mice as well as an HSV-1 keratitis of rabbits confirmed the efficiency of 1 in experimental animal infections. No toxic side effects in both local and systemic applications were observed. Promising data from cell culture and animal experiments recommend 1 as a potential candidate for the local and systemic treatment of HSV-1 and VZV infections in man.     

Establishment of a map of neurons in the brain of Eisenia fetida (Annelida, Oligochaeta) containing substances immunologically specific to vertebrate peptides

Several antisera specific to neuropeptides of vertebrates were applied to sections of the earthworm Eisenia fetida Sav. Some of them were able to reveal specific neurones of the supraoesophageal ganglion: h-GHRF, CRF, Leu- and Met-enkephalin, dynorphin, substance P, CCK-8, and CCK-8S. A map of different areas or nuclei was established in the brain, taking position of reactive cells into account. Four symmetrically paired nuclei and one mediodorsal nucleus were identified and plotted. There is generally no characteristic modification correlated with maturation of the worms. However, the reaction against anti-Leu-enkephalin differs significantly according to age of Eisenia in nucleus No. 1 and particularly in nuclei No. 2 where one cell group presents specific reactivity on and after puberty. Moreover, the successive application of two antisera to the same sections after elution showed no coexistence of substances in a single neurone. By comparison with these vertebrate peptide-like containing nerve cells, the assay to anti-5-HT showed only a few reactive aminergic neurones. An attempt of correlation of cellular types with reactive perikarya is started.     

Atrial natriuretic factor--its possible role in the pathogenesis and therapy of arterial hypertension

Using radioimmunoassay the authors investigated the plasma concentration of the immunoreactive atrial natriuretic factor (IR-ANF) and its content in the atria of 4-, 8-, 12-, 16-, and 20-weeks-old spontaneously hypertensive rats (SHR), and compared the results with data obtained in normotensive Wistar-Kyoto rats of the same age. With hypertension accelerating in SHR between the 8th and the 20th weeks of life, IR-ANF content in the atrium gradually decreased, and the plasma IR-ANF concentration increased. The decline in IR-ANF was due to its decrease primarily in the left atrium. Long-term (6-day) administration of synthetic ANF to SHR with fully developed hypertension led to normalization of BP. The results do not support the hypothesis that arterial hypertension in SHR is induced by a primary deficiency of ANF. The changes in IR-ANF in the atria and plasma occur rather as an adaptive and regulatory response to increasing BP. Prolonged administration of ANF to SHR had a hypotensive effect. Therapeutic application of ANF in man depends on the development of oral and long-acting analogues.