FLUORIDE ACTION NETWORK PESTICIDE PROJECT
Return to FAN's Pesticide Homepage
Return to Abstracts Page
Pineal Gland Abstracts: 1995
Note: the following is a limited selection of abstracts available at PubMed, Science Direct, and Toxnet.
| Abstracts on the Pineal Gland by Year | |||||
- |
2005 (Jan-June) |
||||
1995 |
|||||
J Pediatr Endocrinol Metab 1995 Oct-Dec;8(4):295-9
Pseudo-precocious puberty in a male patient and the melatonin-testosterone relationship.
Luboshitzky R, Tiosano D, Ben-Harush M, Thuma I, Ayash A, Lavie P, Etzioni A.
Department of Endocrinology, Central Emek Hospital, Afula, Israel.
We describe a 14 year-old boy with a pineal germ cell tumor which secreted beta HCG. Serum testosterone levels were markedly elevated with concomitant decreased LH secretion. 24-h serum melatonin levels were suppressed and lacked the normal nocturnal rise. Pineal radiation therapy was followed by tumor regression and the diminution of beta HCG stimulated testosterone, which in turn inhibited melatonin and LH. When beta HCG and testosterone were normalized after tumor radiation, a recovery of normal melatonin and LH secretory pattern occurred. These results indicate that circulating testosterone down-regulates pineal melatonin.
PMID: 8821909 [PubMed - indexed for MEDLINE]
Pediatr Radiol 1995;25(1):7-11
Central precocious puberty: evaluation by neuroimaging.
Kornreich L, Horev G, Blaser S, Daneman D, Kauli R, Grunebaum M.
Department of Pediatric Imaging, Children's Medical Center of Israel, Beilinson Medical Campus, Petah Tiqva.
To evaluate the incidence of abnormal intracranial findings in children with central precocious puberty, 62 children (51 girls, 11 boys) were examined by computerized tomography and/or magnetic resonance imaging (MRI) of the brain. Forty-four had normal examinations; 18 (11 girls, 7 boys) showed intracranial pathologies, including hamartoma of the tuber cinereum (8 cases), parenchymal loss (3 cases), hypothalamic-chiasmatic lesions (2 cases), lesions of the corpus callosum (2 cases), suprasellar cyst (1 case), and pineal cyst and mesiotemporal sclerosis (1 case each). Based on the correlation between the clinical and the imaging results of this series, the authors recommend MRI as the imaging method of choice in the investigation of precocious puberty.
PMID: 7761174 [PubMed - indexed for MEDLINE]
Anat Anz 1995 Jul;177(5):413-9
Ultrastructure and x-ray microanalytical study of human pineal concretions.
Nakamura KT, Nakahara H, Nakamura M, Tokioka T, Kiyomura H.
2nd Department of Oral Anatomy, Meikai University, School of Dentistry, Saitama, Japan.
We examined human pineal concretions and found them to exhibit a multi-layered concentric structure consisting of irregularly spaced dense and sparse zones containing fine crystals. The hydroxyapatite crystallites were shown to be irregularly outlined plate forms (measuring 11-70 nm in their longest dimension and 2-10 nm in thickness). At the center of each crystallite a central dark line was observed by means of high resolution electron microscopy. The structure and size of the crystals were similar to those of dentin and bone. The ground surface of the concretions was observed metallurgically by means of an electron probe microanalyzer (EPMA). The surface zones of the concretions contained a higher concentration of zinc, which seems to play an important role during the mineralization process, whereas calcium and phosphorus exhibited higher concentrations at the center.
PMID: 7645736 [PubMed - indexed for MEDLINE]
J Hist Neurosci 1995 Sep-Dec;4(3-4):155-65
Pineal gland, perennial puzzle.
Schiller F.
Department of the History of Health Sciences, University of California, San Francisco, USA.
Since antiquity this tiny intracranial appendicular organ has aroused sexual connotations and denials. Controversial and enigmatic, it played a significant part in the development of endocrinology and even neurosurgery. What was its histology, what was its role as a gland so intimately attached to the brain? What did comparative anatomists make of it in the light of its function as a 'third eye?' Mysticism and the famous Cartesian apothegm placed it in the center of Eastern and Western approaches to the mind-body problem and to mental disorders. The latter were connected with the common calcifications, so helpful in the radiological diagnosis of brain shifts due to mass lesions. Undefeated, even spurred by continuing uncertainties, researchers keep looking into this 'photo-neuro-endocrine transducer.'
Publication Types: Historical Article
PMID: 11619023 [PubMed - indexed for MEDLINE]
Adv Exp Med Biol 1995;377:1-14
The mammalian pineal gland and reproduction. Controversies and strategies for future research.
Olcese J.
Institute for Hormone and Fertility Research, University of Hamburg, Germany.
Evidence for a role of the pineal gland and its major hormonal product, melatonin, in mammalian reproduction has accumulated for over three decades. In sorting through the masses of data pertaining to this issue, certain facts are becoming established. For example, the pineal gland is clearly involved in seasonal reproductive cycles via transduction of daylength (more properly nightlength) information in the form of plasma melatonin rhythms. Specific melatonin receptors are found in the hypothalamus and pituitary pars tuberalis of most of the mammalian species examined thus far. Melatonin's mode of action on the reproductive axis is quite variable but may, in many cases, involve modulation of gonadotropin-releasing hormone secretion from the median eminence. Clinical evidence continues to support the idea that melatonin may play a role in the timing of puberty.
Publication Types:
Full report available free at: http://www.jbc.org/cgi/content/full/270/38/22314
J Biol Chem 1995 Sep 22;270(38):22314-20
Vesicular L-glutamate transporter in microvesicles from bovine pineal glands. Driving force, mechanism of chloride anion activation, and substrate specificity.
Moriyama Y, Yamamoto A.
Graduate Department of Gene Sciences, Faculty of Sciences, Hiroshima University, Japan.
Pinealocytes, endocrine cells that synthesize and secrete melatonin, possess a large number of synaptic-like microvesicles (MVs) containing the L-glutamate transporter (Moriyama, Y., and Yamamoto, A. (1995) FEBS Lett., 367, 233-236). In this study, the L-glutamate transporter in MVs isolated from bovine pineal glands was characterized as to its driving force, requirement of anions, and substrate specificity. Upon the addition of ATP, the MVs accumulated L-glutamate. The uptake was significantly dependent on the extravesicular Cl- concentration, being negligible in the absence of Cl- and maximum at 2-5 mM and decreasing gradually at 20-100 mM. The membrane potential (inside positive) was maximum at 0-10 mM Cl- and then decreased gradually depending on the Cl- concentration, whereas a pH gradient was practically absent without Cl- and increased gradually up to 100 mM Cl-. Ammonium acetate or nigericin plus K+, a dissipator of a pH gradient, had little effect on or was slightly stimulatory toward the uptake, whereas valinomycin plus K+ inhibited both formation of the membrane potential and the glutamate uptake to similar extents. The ATP- and Cl(-)-dependent glutamate uptake was inhibited by fluoride, iodide, or thiocyanate, without vacuolar H(+)-ATPase being affected. An anion channel blocker, 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid, similarly inhibited the glutamate uptake in a Cl- protectable manner. Furthermore, ATP- and glutamate-dependent acidification of MVs was observed when 4 mM Cl- was present. Among more than 50 kinds of glutamate analogues tested, only a few compounds, including 1-aminocyclohexane-trans-1,3-dicarboxylic acid, caused similar acidification. A good correlation was observed between the acidification and the inhibition of glutamate uptake by glutamate analogues. These results indicated that 1) the major driving force of the glutamate uptake is the membrane potential, 2) Cl- regulates the glutamate uptake, probably via anion-binding site(s) on the transporter, and 3) the transporter shows strict substrate specificity. Hence, the overall properties of the vesicular glutamate transporter in the MVs well matched those of the synaptic vesicle glutamate transporter. We concluded that the vesicular glutamate transporter, being similar if not identical to the neuronal counterpart, operates in endocrine cells.
PMID: 7673214 [PubMed - indexed for MEDLINE]