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Biomedical subjects

R Maggi

Publications and source records attributed to R Maggi.

At least 91 records · Page 5Linked to original sources
PubMed1986

Morphine stimulates prolactin release in normal but not in castrated male rats.

Morphine (200 micrograms/rat) was injected intraventricularly (i.v.t.) into normal and into long-term castrated (4 weeks) adult male rats. Animals were killed 10, 20, 40 and 60 min after treatment. In normal animals, the treatment with morphine resulted in a significant increase of serum prolactin concentrations at all time intervals considered. However, the i.v.t. injection of 200 micrograms morphine/rat into castrated rats did not exert any significant effect on prolactin release at any time interval considered. When morphine (200 micrograms/rat) was administered i.v.t. together with the specific opioid receptor blocker naloxone (7.5 or 15 micrograms/rat) the stimulatory effect of morphine on prolactin release was diminished at 10 min, and totally blocked at 20 min. Naloxone given alone did not influence serum prolactin concentrations. The results suggest that the presence of endogenous androgens is essential to permit the stimulatory effect of morphine on prolactin release.

Animals↗
PubMed1985

Effect of naloxone on luteinizing hormone, follicle-stimulating hormone, and prolactin secretion in the different phases of the estrous cycle.

It is becoming increasingly clear that the effects exerted by opioid agonists and antagonists on the release of gonadotropins and of PRL may vary according to the endocrine milieu. To investigate this issue further, female rats with a regular 4-day estrous cycle have been injected sc with the opioid antagonist naloxone at different hours of the day, during each of the various days of the estrous cycle. The animals were killed 20 min after the sc administration of naloxone (2.5 mg/kg dissolved in 0.9% saline solution) at 1000 and 1600 h on the first and second day of diestrus and at 1000, 1200, 1400, 1600, 1800, and 2000 h on proestrus and estrus. Animals were killed by decapitation, and trunk blood was collected and assayed for LH, FSH, and PRL. The data obtained from naloxone-treated animals were compared to those derived from controls injected sc with 0.9% saline solution and killed at the same time intervals. The sc injections of naloxone stimulated LH release in every phase of the estrous cycle; however the magnitude of the responses was highly variable. Increases of the order of 700-1.000% were observed during the 2 days of diestrus, at 1000 and 1400 h of the day of proestrus, and at 1600, 1800, and 2000 h of the day of estrus. Much higher responses (of the order of 2.700-3.300%) were observed at 1600 h of the day of proestrus and at 1000, 1200, and 1400 h of the day of estrus. The LH response to naloxone appeared to be obliterated at 1800 and 2000 h of the day of proestrus. Serum levels of FSH and PRL were not affected by the treatment at any of the time intervals considered. These findings suggest that, in normally cycling adult female rats, naloxone exerts a stimulatory effect on LH release during each day of the estrous cycle; that the stimulatory effect of naloxone is minimal at the time of the spontaneous proestrous LH surge; and that the effect of naloxone on LH release is, on the contrary, maximal just before the spontaneous proestrous LH surge and up to 1400 h of the day of estrus. The observation that naloxone does not affect FSH and PRL release underlines once more that the central mechanisms controlling LH, FSH, and PRL secretion are different.

Animals↗
PubMed1982

Age-related frequency of viral lesions and their association with uterine cervical intraepithelial neoplasia.

Data collection forms of 50,165 routine smears were examined, and of these 47,577 were considered for this study. Viral cytological lesions (VL) were observed in 101 cases: of these, 19 were associated with cervical intraepithelial neoplasia. The total frequency of VL was 0.21%, with the peak in the teenager group (0.49%). The frequency of CIN among VL showed an overall frequency of 18.8%: this was null under 21 years of age and highest (50%) between 51 and 60 years of age. The frequency of VL in relation to clinical provenance of patients and the season of the year did not attain significance.

Adolescent↗
PubMed1982

Role of the subcommissural organ in the control of gonadotrophin secretion in the female rat.

Thermal lesions were placed in the subcommissural organ (SCO) of female rats with normal cycles and long-term ovariectomized rats. In normal female rats SCO lesions disrupted the oestrous cycle in more than half of the animals, the majority of which entered a state of prolonged dioestrus. In these animals, serum gonadotrophin levels were similar to those of rats with regular cycles on day 2 of dioestrus. In animals in which the oestrous cycle was maintained, a delayed LH surge occurred on the day of pro-oestrus and the pro-oestrous FSH surge was absent. The usual increase in FSH on the day of oestrus was present. Lesions in the SCO did not change the high gonadotrophin levels typical of ovariectomized animals. These results suggested that the SCO may play a role in the control of the cyclic but not the tonic release of the gonadotrophins. In particular, it appears that the SCO might be involved in the regulation of the hypersecretion of FSH during the day of pro-oestrus.

Animals↗
PubMed1981

Role of the subfornical organ (SFO) in the control of gonadotropin secretion.

Radiofrequency lesions have been placed in the subfornical organ (SFO) or normally cycling and of long-term castrated female rats. The data have shown that, in normal female rats, SFO lesions bring about a disruption of estrous cyclicity in a large number of animals, the majority of which enter a state of prolonged diestrus. In these animals, serum gonadotropin levels are similar to those of regularly cycling animals in the second day of diestrus. In the animals in which estrous cyclicity was still present, an LH surge occurred which was regular in timing and magnitude. On the contrary the proestrous FSH surge was absent, but the usual FSH elevation of the day of estrus was present. SFO lesions were not able to change the high gonadotropin levels typical of the post-castration situation. These results suggest that the SFO may play a role in the control of the "cyclic" but not of the "tonic" release of the two gonadotropins. In particular, it appears from the results that the SFO might be involved in the regulation of the hypersecretion of FSH which occurs during the day of proestrus.

Animals↗
PubMedDate not supplied

Effects and metabolism of steroid hormones in human neuroblastoma cells.

The development of the central nervous system is influenced by sex steroids and by their metabolites. However, little information on the possible effects of steroid hormones on neuroblastoma cells is available. Human neuroblastoma cell lines have been used as a model of human neuroblasts in vitro to study the metabolism of steroid hormones; in addition, the effects of steroids and steroid antagonists on neuroblastoma cell growth have also been investigated. The results obtained show that SH-SY5Y human neuroblastoma cells may actively metabolize testosterone and progesterone to their respective 5 alpha-reduced metabolites and that differentiation of neuroblastoma cells is paralleled by a significant increase in expression of the type-1 5 alpha-reductase and of the formation of steroid metabolites. All these data are suggestive of a potential role of steroid 5 alpha-reduced metabolites in the biology of neuroblastoma cells. Studies performed to analyze the role of steroid hormones on neuroblastoma cell proliferation show that progesterone at low doses may induce minor stimulation, and at higher doses, a toxic effect on the neuroblastoma cell line SK-N-SH is seen. Moreover, the antiprogestin 17 beta-hydroxy-11 beta-(4-dimethylamino-phenyl-1)-17-(prop-1-ynyl)estra-4,9-dien+ ++-3-one (RU486) decreases the proliferation of these cells in a dose-dependent manner. The effect of RU486 is not antagonized by either progesterone or dexamethasone, a result that seems to exclude the action of RU486 via classic intracellular steroid hormone receptors.

Cell Division↗
PubMedDate not supplied

Lactose malabsorption and intolerance in Uruguayan population by breath hydrogen test (H2).

This study of 200 Uruguayans between 0 and 86 years old was designed to determine the prevalence of lactose malabsorption. Lactose intolerance is defined as a clinical syndrome of abdominal pain, diarrhea, flatulence, and bloating after the ingestion of a standard lactose tolerance test dose (2 g of lactose per kilogram of body weight or 50 g/m2 of body surface area, maximum 50 g in a 20% water solution). Lactose malabsorption refers to the state in which dietary lactose remains unhydrolyzed and subsequently unabsorbed from the gastrointestinal tract; symptoms may or may not result from lactose malabsorption. The technique of breath hydrogen (H2) was used after ingestion of 2 g/kg body weight to a maximum of 50 g in a 20% solution. There was no lactose malabsorption in children younger than 5 years old. The prevalence increases progressively after the age of 5, and in adolescence the percentage of malabsorption is similar to that in adults, who show 65% lactose malabsorption, with 25% asymptomatic and 40% intolerant. In 109 white adults, the prevalence of lactose malabsorption is 63%, with 24% asymptomatic and 39% intolerant. In 11 black adults, lactose malabsorption is 82%, with 27% asymptomatic and 55% intolerant. The difference between white and black adults is statistically significant (p less than 0.05). The H2 test is simple, reliable, noninvasive, and appropriate to study large populations.

Adolescent↗
PubMedDate not supplied

Tendon surgery in Brown's syndrome.

PURPOSE: Longitudinal tenectomy of the reflected tendon of the superior oblique muscle resulted in full recovery in a series of cases of Brown's syndrome after surgery by one of the authors. METHODS: A survey of the records of cases of Brown's syndrome was done to assess the criteria for patients requiring surgery and to evaluate the methods used. Included in the study were 9 eyes of patients who underwent surgery over the course of 1 year. Criteria identified in cases in this study include: preoperative compulsory head tilt in primary position of gaze, severe restriction of Hess chart in the affected eye, and an enlarged field in the healthy eye; intraoperative thickening of the tendon preventing free slippage through the trochlea in the forced duction test. The surgical method consisted of trimming a swelling that was consistently found on the reflected tendon of the superior oblique muscle in all patients undergoing surgery. Enough of the swelling was removed to allow free slippage of the tendon through the trochlea, as judged by the forced duction test. Sulphamide powder soaked in delayed action steroid compound (methylprednisolone acetate) was applied to prevent postoperative adhesions. RESULTS: A normal head posture and a satisfactory upward vergence were achieved in all patients from the first days after surgery, and were maintained throughout the follow up, as shown in the pre- and postoperative photographs and Hess charts. CONCLUSIONS: A preliminary exploration of the reflected tendon of the superior oblique muscle is warranted in cases of Brown's syndrome; when a thickening of the tendon is found, its surgical trimming is advised. Our findings suggest that delayed development of the trochlea may be a possible cause of Brown's syndrome.

Child↗
PubMedDate not supplied

Scleral fixation for a phakic anterior chamber disc intraocular lens.

BACKGROUND: Angle-supported phakic anterior chamber intraocular lenses (IOLs) require a high degree of anterior vaulting, but this can cause an inadequate distance between the IOL and the cornea, especially during rubbing or squeezing of the eye. METHODS: A vaultless implant was designed by anchoring 3 supple hepatics through the anterior chamber into the sclera. Thus, a suspended rather than a wedged implant was achieved. RESULTS: The lens was implanted in 3 eyes of 2 patients in 1990. Good tolerance of the IOL was maintained over 7 years of follow-up. CONCLUSION: A suspended anterior chamber phakic IOL maintains an adequate position with lack of bowing and shows promising results.

Adolescent↗
PubMedDate not supplied

Antiproliferative action of melatonin on human prostate cancer LNCaP cells.

Recent experimental evidence suggests that melatonin, the major pineal hormone, might possess oncostatic properties. The present experiments were performed to verify whether melatonin might modulate the growth of androgen-dependent prostate cancer cells (LNCaP) and to obtain information on its possible mechanism of action. We have shown that melatonin, when given in the nanomolar range, significantly inhibits the proliferation of LNCaP cells; moreover, the pineal gland hormone affects cell cycle distribution by inducing an accumulation of the cells in G0/G1 and a decrease in S phase. To investigate the mechanism of action of melatonin, by RT-PCR analysis we were able to demonstrate the expression, in prostate cancer cells, of a mRNA coding for the membrane Mel1a melatonin receptor. However, by radioreceptor assay, no detectable binding of 2-[125I]iodomelatonin could be observed in membrane preparations from these cells, suggesting that the levels of translation of the mRNA for Mel1a are possibly too low to mediate the antiproliferative action of the hormone. This hypothesis is further supported by the following observations: i) melatonin analogs, specifically acting through membrane receptors (i.e., 2-bromomelatonin), were completely ineffective in modulating prostate cancer cell proliferation; ii) melatonin failed to prevent forskolin-induced cAMP accumulation. These results indicate that melatonin, at nanomolar concentrations, exerts a direct antiproliferative action on androgen-dependent prostate cancer cells, significantly affecting their distribution throughout the cell cycle. Membrane receptors do not seem to be involved in the oncostatic action of the pineal gland hormone.

Androgens↗
PubMedDate not supplied

Parenteral nutrition in intractable diarrhea.

Twelve infants with protracted diarrhea, unmanageable by the usual procedures, were treated with Total Central Parenteral Nutrition. Eleven of them were less than six months old. Two infants died in the course of treatment; the other ten recovered. The authors discuss the indications of this procedure, the technique used and, the possibility of performing it in centers not specialized in Nutrition.

Diarrhea, Infantile↗
PubMedDate not supplied

[Spinocellular carcinoma of the vulva. Critical review of the surgical case histories from 1967-1989].

A critical review of the surgical treatments performed during the years 1967 to 1989 in cases of squamous cell vulvar cancer at the 1st Department of Obstetrics and Gynecology of the University of Milan has been carried out. Two hundred and seventy cases of primary squamous cell vulvar carcinoma have been studied after a restaging according to recent FIGO recommendations. Depending on the type of surgical approach the early and late complications and the 5 year-cancer-related survival have been analyzed. The present investigation supports the importance of a complete and accurate surgical staging of vulvar carcinoma, particularly as far as it concerns the lymph nodes status. Thus, performing a node dissection in case of an invasive neoplasia is extremely important, not only for a precise staging but mainly for a prognosis formulation. In fact, 5 year cancer related survival dramatically falls from almost 90% to 25% in case of pelvic node metastasis.

Aged↗
PubMedDate not supplied

[Immunobiology of vesicular mole and choriocarcinoma].

Molar tissue expresses HLA antigens evidenced in the father. These antigens are present on the trophoblastic extravillous tissue, not on the syncytium and cytotrophoblast. These antigens show some characteristics of Qa murine antigens mapped in the HLA system linked to class I antigens. Antibodies anti HLA against the partner antigens and lymphocytotoxic antibodies have been evidenced in the serum of patients with vesicular mole. In vesicular mole the production of antibodies should be determined by the immunogenicity of cells that infiltrate the decidua, expressing paternal HLA antigens. It has been demonstrated that the recognition of "not self" antigens in the mother should stimulate a cellular immune response. We do not know why the tumor grows. Maybe the woman is not able to produce anti HLA antibodies although recognizes them as "not self", or the patients is not antigenically stimulated because there is immunocompatibility between the two partners. The literature shows that the development and progression of the disease are stimulated by histocompatibility, although this factors does not seem fundamental. If the two partners are histocompatible the tumor can be less immunogenic, so the mother shows a lower response and the growth of the tumor appears to be favoured.

Choriocarcinoma↗
PubMedDate not supplied

[Primary carcinoma of the fallopian tube: cases from 1971 to 1985 (27 patients). Current therapeutic approaches].

Twenty-seven patients with carcinoma of the fallopian tube were treated at the First Obstet. Gynecol. Clinic, University of Milan. Nineteen of them had the primary surgical procedure in our center and accounted for 2% of tubal and ovarian carcinomas. The others had been operated elsewhere. Another primary genital cancer occurred in 7 of these women and a breast carcinoma was recorded in the history of other 2. At laparotomy, 11 tumors were Stage I, 9 Stage II, and 7 Stage III. Postoperative adjuvant therapy was not homogenous, however chemotherapy was given to about 59% of patients. Five years survival rate was 65% for Stage I, 34% for Stage II and 17% for Stage III. The discussion deals with early diagnosis, prognostic and/or therapeutic role of pelvic and/or aortic lymphadenectomy and effectiveness of adjuvant therapy.

Adult↗