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J Leonardelli

Publications and source records attributed to J Leonardelli.

At least 19 recordsLinked to original sources
PubMed1995

[Immunocytochemical analysis of human prolactin receptors using anti-idiotypic antibodies in human breast cancer].

In this study, we have prepared antiidiotypic antibodies specific of human prolactin receptors (PRL-R) in order to localize these receptors in breast cancer. Antiidiotypic antibodies were prepared using anti-human prolactin (anti-hPRL) sera obtained from New Zealand rabbits. 25 breast cancer were PRL-R positive using radio receptor assay. For immunohistochemistry, the tissues fixed with Nakane and treated by NH4Cl and Saponin to improve staining specificity, were incubated with antiidiotypic antibodies (1/100e). Cytoplasm and membrane of human breast cancer cells were PRL-R positive in 20/25 breast cancer with antiidiotypic antibodies. There was no staining with preimmune serum and immunohistochemical staining elimination by prior absorption with anti-hPRL antibodies.

Antibodies, Anti-Idiotypic↗
PubMed1992

[Marijuana and reproduction. Effects on puberty and gestation in female rats. Experimental results].

The main psychoactive component of marihuana, delta-9-tetrahydrocannabiol (THC), was investigated at low doses (1 microgram/kg/day) on the onset of puberty, on the reproductive functions in female rats up to the seventy fifth to eightieth day of life as well as during the pregnancy. The administration of THC caused a delay of the onset of puberty, and the number of ova on the day of first estrus was significantly lower in treated animals. After puberty, alterations occurred in the neuroendocrine functions of animals received THC: estrous cycles were irregular, serum LH level was decreased. When THC was injected during the third week of pregnancy it caused a significant prolongation of the gestation period. There was 30% stillbirths (v.s. 3% in physiological saline treated rats). No teratological effects were observed. Serum LH, progesterone and prostaglandin contents were decreased. The results indicate that marihuana causes alterations in reproductive functions. The importance of fight against drug abuse is emphasized.

Animals↗
PubMed1991

Prenatally administered delta-9-tetrahydrocannabinol temporarily inhibits the developing hypothalamo-pituitary system in rats.

We have reported earlier that delta 9-tetrahydrocannabinol (THC) if injected over the 3rd week of pregnancy with a daily dose of 1 micrograms/kg b.wt., caused a significant prolongation of pregnancy and 42% of stillbirths, although no teratological effects were observed. In the present study, we investigated the postnatal development of hypothalamo-hypophyseal-gonadal axis of the above mentioned rats' living litters. The rats were killed every 5th day between the delivery (D0) and the 20th postnatal day (D20). The weight of the body and the gonads was measured and hormonal parameters were registered by RIAs. The body weight was lower in treated animals, with a higher degree in males. The weight of the gonads also decreased. Serum testosterone levels were lower in rats from D0 till D10, while at D15 and D20 no differences were recorded between controls and treated rats. No significant differences were observed in serum estrogen levels during the investigated period. Serum progesterone decreased up to D10. Pituitary luteinizing hormone (LH) diminished postpartum in both sexes up to D5. From D0 till D5, serum LH increased in males while it decreased in females. Hypothalamic luteinizing hormone releasing hormone decreased up to D15 in both sexes, less markedly in females than in males. The neuropeptide Y content of the hypothalamus was also decreased in early postnatal age. We concluded that a very low dose of prenatally administered THC caused transitory inhibition of the developing hypothalamo-pituitary-gonadal axis, i.e., postnatal changes were evoked in the neuroendocrine system. By the 20th postnatal day this effect of THC seemed to be eliminated.

Animals↗
PubMed1991

[Role of Schistosoma mansoni bilharziasis in male hypogonadism].

In tropical and subtropical areas, schistosomiasis may cause anatomic anomalies of the genital organs responsible for permanent or reversible infertility. Furthermore, it has been suggested that this parasitic infection may have adverse consequences on the endocrine system. To specify the effects of schistosomiasis on endocrine function, production of pituitary gonadotropins and testosterone in rats and hamsters experimentally infected with Schistosoma mansoni was studied. Prior to infection, hormone levels were within the normal range for our laboratory in all animals studied. Hormone levels (FSH, LH and testosterone) fell significantly in all experimentally infected animals, as compared with uninfected controls. These data suggest that the inhibitory effect (documented by the fall in all the hormone parameters studied) of Schistosoma mansoni on gonadal function is due to an action at the hypothalamic or pituitary level. The potential role of parasite ecdysteroids in the mechanism of action of schistosomes deserves to be studied.

Animals↗
PubMed1989

[Enkephalin-like immunoreactivity in Leydig cell tumor].

So far, the presence of an enkephalin-like immunoreactivity has never been reported in Leydig cell tumors at our knowledge. A 39 years old man having a painful gynecomastia and an impotency changing in time has been studied. At clinical examination, he was normal, without palpable testis tumor. The sperm count analysis showed an oligoastheno-spermia. Plasma testosterone (T) was low and plasma estradiol (E2) was high, varying from day to day. T/E2 ratio was always low (20 to 72 - N:220-240) and fell after HCG administration. Plasma LH was normal and plasma FSH was low. 17 hydroxyprogesterone (17 OH-P)/T ratio was increased (0.7 - N:0.23). A small tumor was localized in the left testis by ultrasonography. The spermatic vein catheterization, which was only possible on the left side, showed a decreased T, a high E2 and a low T/E2 ratio (19 - N:304). After unilateral orchidectomy, the histological study confirmed the diagnosis of Leydig cell tumor. With antibodies raised against synthetic Met-en-kephalin, it has been possible to detect an enkephalin-like immunoreactivity in the tumoral cells as well as in the surrounding normal cells.

Adult↗
PubMed1986

Immunohistochemical localization of enkephalinlike peptides during testicular development in rats.

The distribution of opioid peptides is of interest in the rat testes, because the presence of opiate binding sites strongly supports the hypothesis of paracrine function for these peptidergic factors. Testes of Wistar albino rats between birth and adult stage were examined immunocytochemically for enkephalins, dynorphin, and alpha neoendorphin. The presence of immunoreactive enkephalinlike substances was visualized in both interstitial tissue and seminiferous tubules, but no staining was observed for dynorphin or neoendorphin. In interstitial tissue the material stained in Leydig cells raised after birth, declined at day 12, and increased again between day 22 and day 35 of life. From day 35 till adult stage we observed again a slight decrease of immunostaining. In seminiferous tubules, intense immunostaining was observed in stem spermatogonia until day 7 of life. After this period the presence of immunoreactive enkephalinlike material was detected, mainly in some spermatogonia and peritubular primary spermatocytes. These data suggest a possible implication of enkephalinlike peptides in spermatogonesis.

Animals↗
PubMed1983

Serotonin axons of the ependyma and circumventricular organs in the forebrain of the guinea pig. An immunohistochemical study.

The distribution of supraependymal nerve fibers (SEF) containing serotonin (5-HT) was investigated immunohistochemically in the forebrain of the guinea pig. The highest densities of immunoreactive axons were found in the pars centralis and the inferior horn of the lateral ventricle and also in the superior part of the third ventricle. Because of the special development of the choroid plexus in these ventricular regions, it is suggested that 5-HT SEF might be involved in the regulation of the composition of the cerebrospinal fluid. The ependyma lining the circumventricular organs located in the forebrain, was not observed to receive a significant 5-HT-SEF innervation. In the pituitary gland, a loose but constant network of 5-HT axons, resembling those which course in the anterobasal hypothalamus, arcuate nucleus and internal layer of the median eminence, was observed in the neural lobe. In the epiphysis, immunoreactive 5-HT was detected in all pinealocytes (the entire cell was filled with reaction product) and in fibers running between them.

Animals↗
PubMed1983

Gonadotrophin-like substance in the testis. Immunocytochemical localization in the guinea pig.

A gonadotrophin-like material (GLM) was observed by immunocytochemical methods in prepuberal guinea pig testes, not only on Sertoli and interstitial cells, but also on spermatogonia and spermatocytes. The intracellular cytoplasmic localization of GLM is discussed in relation to the receptor internalization theory. Variations between young and adult animals allowed us to approach the physiological significance of testicular GLM.

Animals↗
PubMed1983

[Hypothyroidism and the Gougerot-Sjögren syndrome].

The signs of Sjögren's syndrome were systematically researched in 36 patients with hypothyroidism (myxoedema with atrophic thyroiditis in 32 cases, Hashimoto's thyroiditis in 4). In a quarter of these patients were noted separately submaxillary glands and/or parotids enlarged, buccal and/or lacrymal sicca syndromes, and antisalivaryy ducts antibodies. The histologic analysis of minor salivar glands revealed foci of lymphocytes and plasmocytes (grades 3 and 4 of Chisholm's classification) in 6 subjects. Similarities between the Sjögren's syndrome and the autoimmune thyroiditis were specified; their association in the same patients might be explained considering the genetic predisposition to these affections.

Adult↗
PubMed1981

Comparative immunocytochemical localization of enkephalin and somatostatin in the median eminence, hypothalamus and adjacent areas of the guinea-pig brain.

Because of the presence of an enkephalin-related substance in the somatostatin terminals of the median eminence, an investigation was carried out on the staining for enkephalin of the somatostatin-containing perikarya localized in the hypothalamic periventricular nucleus. Only an occasional and weak enkephalin immunoreactivity was detected in these perikarya, making the common synthesis of the two peptides unlikely. Moreover, our results demonstrate an enkephalin staining in other fibers of the median eminence clearly distinct from the somatostatin ones. Enkephalin was demonstrated in perikarya distributed in the septum, preoptic area, dorsal and ventromedial hypothalamus, all regions known to possibly project into the median eminence. In none of these sites was enkephalin found in association with somatostatin. The present morphological results support the hypothesis that enkephalins may exert their GH-releasing effect at the hypothalamic level and suggest that enkephalins might directly modulate the somatostatin release into the blood of the portal plexus.

Animals↗
PubMed1980

Circadian and cyclic LHRH variations in the organum vasculosum of the lamina terminalis of female and male rats.

The organum vasculosum of the lamina terminalis (OVLT) was investigated by immunofluorescence and quantitative electron microscopic methods, and its LHRH content was measured at intervals during the estrous cycle and in male rats. A well-defined circadian rhythm in the LHRH content was demonstrated in the OVLT. The highest value was observed on the day of proestrus with peaks at noon and in the late afternoon. The amount of LHRH was about the same in the male as in the female rats on the day of diestrus 1. The OVLT in both sexes contained LHRH-positive fibers and terminals, but less immunofluorescence was visible on the day of diestrus and in the male animals. Quantitative electron microscopic analysis shows that in the OVLT nerve terminals, abutting on the basement membrane, more granulated vesicles (80-90 nm in diameter) are present on the day of proestrus than on any other day of the cycle or in the male. Our results suggest that the OVLT may participate in some way in the control of the cyclic gonadotrophic function of the anterior pituitary and/or in the behavioral effect of sexual hormones.

Animals↗
PubMed1979

Immunohistochemical localization of enkephalins in median eminence and adenohypophysis.

Immunohistochemical staining for methionine-enkephalin and leucine-enkephalin were used to reveal an enkephalins-like substance in the median eminence and adenohypophysis of guinea pig and rat. Nerve endings were stained for enkephalins in the external layer of the median eminence. By successive staining of two different antigens, somatostatin fibers in the guinea pig were also shown to be enkephalin-immunoreactive. Staining of the adenohypophysis varied with the species and the antisera used. Intermediate lobe and corticomelanotrophs were stained moderately. In both species, and with all the antisera, thyrotrophs were shown to contain an immunoreactive substance. In the guinea pig, gonadotrophs were stained particularly by the anti-leucine-enkephalin antiserum used. The locus of enkephalin action on pituitary functions can be discussed: enkephalins possibly have an inhibiting action on somatostatin fibers, which agrees with the stimulating action of enkephalins on GH already known. Furthermore, enkephalins could have a direct action on pituitary glycoprotein proceducing cells, which would explain their inhibiting action demonstrated previously on LH, FSH and TSH.

Animals↗
PubMed1979

Immunoreactivity for beta-endorphin in LH-RH neurons of the fetal human hypothalamus.

A peptide immunochemically related to beta-endorphin was detected in some LH-RH neurons of the fetal human hypothalamus by comparison of adjacent sections stained for beta-endorphin and for LH-RH. In the same section, by successive staining and after antibody elution, both peptides were again revealed in the same neuron. The significance of the presence of the beta-endorphin-like material in LH-RH neurons is discussed.

Adrenocorticotropic Hormone↗