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Biomedical subjects

R Maggi

Publications and source records attributed to R Maggi.

At least 73 records · Page 4Linked to original sources
PubMed1990

Evaluation of different surgical approaches in the treatment of endometrial cancer at FIGO stage I.

From January 1, 1970 to December 31, 1979, 425 cases of endometrial carcinoma, FIGO stage I, were treated at the First Department of Obstetrics and Gynecology, University of Milan. Three different surgical approaches were used: total abdominal hysterectomy with bilateral salpingo-oophorectomy and selective pelvic lymphadenectomy was performed in 245 women, total abdominal hysterectomy and bilateral salpingo-oophorectomy without pelvic lymphadenectomy in 100, and vaginal hysterectomy with bilateral salpingo-oophorectomy in 80. Five-year survival was evaluated as a function of risk factors (histological grade, depth of myometrial invasion, metastatic nodes) in the three groups of patients, and we conclude that lymphadenectomy is useful for prognostic purposes but does not confer a therapeutic benefit.

Adult↗
PubMed1990

Oral contraceptive use and invasive cervical cancer.

The relationship between oral contraceptive use and the risk of invasive cervical cancer was investigated using data from a hospital-based case-control study conducted in the greater Milan area, Northern Italy. A total of 367 women under 60 years of age with a histologically confirmed diagnosis of invasive cervical cancer was compared with a group of 323 controls admitted for a spectrum of acute conditions, non-gynaecological, hormonal or neoplastic and apparently unrelated to oral contraceptive use. Cases had used oral contraceptives more frequently than controls, the age-adjusted relative risk (RR) being 1.53 (95% confidence interval 0.99-2.36). The risk increased with duration of use: compared with never users the age-adjusted RR was 1.48 for up to two years and 1.83 for more than two years (chi 2(1) = 5.28, p = 0.02). Allowing for major identified potential confounding factors, including sexual and reproductive habits, by means of multiple logistic regression, did not explain the association (multivariate RR 1.85 for ever use, 1.05 for up to two years and 2.47 for more than two years). When the interaction between oral contraceptive use and parity or sexual habits was analysed, the effects of various factors appeared independent: the point estimate for multiparous oral contraceptive users versus nulliparous never users was 8.01. There was no consistent influence on risk of invasive cervical cancer of age at first use, whereas the RRs were slightly greater for women who had first used oral contraceptives less than ten years before or had last used them less than five years before diagnosis: these findings, however, were far from significant.

Adult↗
PubMed1990

Artificial maintenance of the relative ocular tissue pressure during eye surgery.

We describe an operating table in which the whole patient, apart from the eye undergoing surgery, is enclosed in a caisson within which the barometric pressure can be lowered at any time during surgery. This increases the effect of atmospheric pressure on the eye, enabling 'open sky' surgery to be carried out on patients of any age.

Atmospheric Pressure↗
PubMed1989

Successful in vitro fertilization and embryo transfer after limited surgical treatment for tubal adenocarcinoma.

A 29-year-old woman with tubal adenocarcinoma stage IA was treated only with bilateral salpingectomy, pelvic lymphadenectomy, and omentectomy. Two years later the patient successfully underwent in vitro fertilization and embryo transfer, and at 39 weeks gave birth to a healthy son by cesarean section. The result of oncologic follow-up 3 years after surgery is negative.

Adenocarcinoma↗
PubMed1989

Modulation by sex steroids of brain opioid receptors: implications for the control of gonadotropins and prolactin secretion.

Several experiments have been performed in order to analyze whether physiological or experimental changes of the endocrine environment might modify the binding characteristics of brain mu and kappa opioid receptors in the brain of the female and male rat. (a) In a first series of experiments, it has been observed that in the whole brain of regularly cycling female rats the number of mu receptors shows variation during the different phases of the estrous cycle. In particular a significant increase of the number of mu receptors has been observed in the morning of proestrus and in the afternoon of estrus. (b) In a second series of experiments, it has been shown that the administration of estrogens brings about a significant increase in the number of mu receptors in the hippocampus and in the thalamus of ovariectomized rats, while the administration of a regime including estrogen and progesterone induces a significant decrease of the number of mu receptors in the hypothalamus and in the corpus striatum. These data seem to indicate that hypothalamic mu receptors may be involved in the positive but not in the negative feedback control of LH secretion. (c) In a third series of experiments, it has been found that the number of mu receptors in the whole brain of 15- and 22-month-old male rats and in the hypothalamus of 22-month-old male rats is significantly lower than in the same tissues of young animals; moreover, the administration to old animals of testosterone does not modify the number of hypothalamic mu opioid receptors, indicating that the decline of brain mu receptors in old animals is not the consequence of the physiological decline of testosterone secretion but probably represents an autonomous phenomenon. (d) In a fourth series of experiments, it was shown that, in young male rats, the concentration of kappa receptors is extremely variable in different regions of the brain. The highest concentrations have been found in the hypothalamus and in the striatum; also in the mesencephalon and in the amygdala kappa receptors are present in rather elevated quantities; lower concentrations have been found in the thalamus, the frontal poles, the hippocampus and in the anterior and posterior cerebral cortex. These experiments have shown in addition that the process of aging induces an increase of the number of kappa receptors in the amygdala and in the thalamus; no age-linked modifications were observed in the other structures examined.(ABSTRACT TRUNCATED AT 400 WORDS)

Aging↗
PubMed1989

Distribution of kappa opioid receptors in the brain of young and old male rats.

The experiments to be described have been designed in order to: (a) provide new information on the concentrations of opioid kappa receptors in different regions of the brain of the male rats; and (b) to analyze whether the density of brain kappa receptors might be modified by the process of aging. The concentration of kappa receptors was investigated in the hypothalamus, amygdala, mesencephalon, corpus striatum, hippocampus, thalamus, frontal poles, anterior and posterior cortex collected from male rats of 2 and 19 months of age. 3H-bremazocine (BRZ) was used as the ligand of kappa receptors, after protection of mu and delta receptors respectively with dihydromorphine and d-ala-d-leu-enkephalin. The results obtained show that: (1) in young male rats, the number of kappa opioid receptors is different in the various brain areas examined: the hypothalamus and the striatum have a concentration of kappa binding sites which is significantly higher than that found in the mesencephalon and in the amygdala; much lower concentrations of kappa binding sites have been found in the thalamus, the frontal poles, the hippocampus, the anterior and posterior cerebral cortex. (2) Aging exerts little influence on the number of kappa receptors in the majority of the brain structures considered. However in the amygdala and in the thalamus the number of kappa receptors was increased in old animals. To the authors' knowledge, the data here presented are the first ones which suggest that age may increase rather than decrease the number of neurotransmitter receptors in the brain.

Aging↗
PubMed1989

Comparison of repeat smear, colposcopy, and colposcopically directed biopsy in the evaluation of the mildly abnormal smear.

Repeat smear, colposcopy, and colposcopically directed biopsy were performed in 161 patients referred to our department because of a Pap smear showing mild dysplasia (CIN 1). Colposcopically directed biopsies revealed the presence of CIN of different grades in 61 cases (37.5%). In 33 (20.4%) the CIN grade found at biopsy was higher than 1. Repeat smear confirmed the presence of CIN 1 in 67 women (47.2%). In this group of patients colposcopically directed biopsies showed a CIN grade greater than 1 in 12 cases (17.9%). The repeat smear was negative in 59 patients (41.5%). In this group, biopsy showed varying grades of neoplasia in 12 cases. Colposcopic examination indicated no dysplasia but the presence of minor cervical abnormalities in 76 women (47.2%): at biopsy a CIN grade higher than 1 was found in 9 cases (11.5%). These data suggest that the mildly atypical smear identifies a group of patients at increased risk of CIN but gives little or no information on the disease severity. Repeat smear and colposcopic examination alone appear inadequate to demonstrate the severity of the cervical lesion. Due to the high proportion of CIN 2 and 3 in patients with a mildly abnormal smear, the systematic biopsy of any colposcopically abnormal area seems essential to proper management of the patient.

Adult↗
PubMed1989

Neonatal organization of the brain opioid systems controlling prolactin and luteinizing hormone secretion.

It is known that the neural mechanisms which control PRL and gonadotropin secretion are different in male and female rats. The present experiments have been designed in order to analyze: 1) whether sexual differences exist in the responses of PRL and LH to the opioid antagonist naloxone; and 2) the mechanisms underlying these possible differences. To this purpose the responses of PRL and LH to the sc injection of either saline (0.5 ml) or naloxone (2.5 mg/kg) have been tested in the following four groups of animals: 1) normal male rats; 2) normal female rats; 3) female rats treated on the second day of life with 1.25 mg testosterone (androgenized female rats); and 4) male rats orchidectomized 2 days postnatally (demasculinized male rats). The naloxone challenge has been provided when the animals were 16, 26, and 60 days old; the animals were killed in the afternoon 20 min after treatment. The results obtained have shown that the acute injection of naloxone significantly decreases serum levels of PRL in normal males and in androgenized females at all ages considered. On the contrary, the opioid antagonist was always ineffective in normal females and in neonatally castrated males. The treatment of male rats with naloxone was without any effect on LH release before puberty (at 16 and 26 days of age), but induced a significant increase of serum LH titers after sexual maturation (60 days). In normal females, naloxone brought about a significant increase of serum LH only at 16 and 60 days (animals in estrus), but not at 26 days. Treatment with naloxone did not exert any significant effect on LH release in androgenized females and in deandrogenized males of any age. The present data suggest that, in the rat a sexual difference exists in the opiatergic control of PRL secretion; apparently, the central opioid systems which regulate PRL secretion develop towards a male pattern because of the presence of androgens in the neonatal period. On the contrary neonatal androgens do not seem to exert any important effect in directing the organization of the opiatergic mechanisms controlling LH release.

Aging↗
PubMed1988

Effects of aging on pituitary and testicular luteinizing hormone-releasing hormone receptors in the rat.

Aging exerts profound influences on the function of the hypothalamic-pituitary-testicular-axis. This work has been performed in order to verify whether, in male rats, the decreased secretion of LH and testosterone (T) occurring in old animals is reflected by modifications of luteinizing hormone-releasing hormone (LHRH) receptors at the level of the anterior pituitary and of the testes. To this purpose, the affinity constant (Ka) and the maximal binding capacity (Bmax) for the LHRH analog [D-Ser(tBu)6]des-Gly10-LHRH-N-ethylamide were evaluated, by means of a receptor binding assay, in membrane preparations derived from the anterior pituitary and testicular Leydig cells of male rats of 3 and 19 months of age. Serum levels of LH and T were measured by specific RIAs. The results obtained show that, in aged male rats, the concentration of pituitary LHRH receptors is significantly lower than that found in young animals. On the other hand, the concentration of LHRH binding sites is significantly increased on the membranes of Leydig cells of old rats. In no instance the Ka for the LHRH analog is significantly affected. Serum levels of LH and T are significantly lower in old than in young male rats. In conclusion, these results suggest that the reduced secretion of LH in old male rats may be linked, at least partially, to a decrease of the number of pituitary LHRH receptors. The impaired production of testosterone occurring in aged rats is accompanied by a significant increase of the number of testicular LHRH receptors, indicating that also the intratesticular mechanisms controlling testosterone release undergo significant alterations with aging.

Aging↗
PubMed1988

Preneoplastic lesions of the vulva.

The authors, after a short review of the anatomo-clinical and epidemiologic patterns of vulvar preneoplastic lesions (VIN), analyze the emerging data from the most recent Literature. From them they suggest a series of questions about the vulvar neoplasia natural history and the biological precursors of this disease. They foresee that the integration of the results that can be obtained from the advanced studies could succeed in clearing up the neoplastic potentiality of preneoplasic vulvar lesions.

Adult↗
PubMed1987

Decrease of mu opioid receptors in the brain and in the hypothalamus of the aged male rat.

Experiments have been designed in order to analyze whether the binding capability of mu opioid receptors in the brain of the male rat is modified by age. In a first experiment, the number of receptors (Bmax) and the constant of affinity (Ka) for the mu ligand 3H-dihydromorphine (3H-DHM) have been measured in the whole brain of male rats of 2, 15 and 22 months of age. In a second experiment the Bmax and the Ka for 3H-DHM have been evaluated in the hypothalamus of male rats of 2 and 22 months of age. In this experiment it was also investigated whether the administration of exogenous testosterone modifies the number and/or the affinity of the hypothalamic mu receptors. Serum levels of LH, FSH, prolactin and testosterone have been measured by specific RIAs. The results obtained show that: serum testosterone levels are significantly decreased in aged rats, while serum LH and FSH show only a small decline; serum prolactin is higher in old than in young animals; the number of mu receptors in the whole brain of 15 and 22 month old animals and in the hypothalamus of 22 month old rats is significantly lower than in the same tissues of young animals; the administration to old animals of testosterone, in doses able to bring back towards normal serum levels of testosterone, induces a decrease of LH and FSH, but has no effect on serum prolactin titers. Testosterone administration does not modify the number of hypothalamic mu opioid receptors, indicating that the decline of brain mu receptors in old animals is not the consequence of the physiological decline of testosterone secretion; in no instance the Ka for the mu ligand is significantly affected.

Aging↗
PubMed1987

Gonadal steroid modulation of brain opioid systems.

It is becoming increasingly clear that the effects of the opioids and their synthetic analogs on anterior pituitary function largely depend on the steroid milieu present in the animal at time of drug administration. However, it is still unclear whether gonadal steroids regulate the opioid-modulated mechanisms by affecting the number of opiate receptors in the brain. To further investigate these issues, the effects of opiate agonists and antagonists on LH, FSH and prolactin (Prl) secretion have been studied in: (a) normal and castrated male rats, and (b) normally cycling female rats. The binding characteristics of the brain subclass of mu opiate receptors have been analyzed in the same group of experimental animals; this type of receptors seems to be particularly involved in the control of gonadotropin and Prl release. When injected intraventricularly into normal male rats, morphine (200 micrograms/rat) induced in a significant elevation of serum LH levels at 10 and 20 min. In long-term castrated animals the administration of the drug significantly reduced LH secretion at 40 and 60 min after the injection, the inhibition lasted up to 180 min. Morphine, when given intraventricularly to normal males, induced a conspicuous and significant elevation of serum Prl levels at 10, 20, 40 and 60 min after treatment. However, when the drug was administered to castrated rats, it did not significantly affect Prl release at any time interval considered. Morphine intraventricular injections did not modify serum FSH levels either in normal or in castrated male rats. The concentration of mu opiate receptors was found to be similar when measured in the whole brain of normal and orchidectomized rats. In adult cycling female rats, s.c. injections of naloxone (2.5 mg/kg) stimulated LH release in every phase of the estrous cycle; the magnitude of the responses was highly variable, being particularly elevated at 16.00 h of the day of proestrous and at 10.00, 12.00 and 14.00 h of the day of estrous. Conversely, LH response to naloxone was totally obliterated at 18.00 and 20.00 h of the day of proestrous, when the preovulatory LH surge was found to occur. The concentration of brain opiate receptors of the mu type showed significant variations during the different phases of the estrous cycle, with higher levels at 12.00 h of the day of proestrous and at 18.00 h of the day of estrous.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1987

Aging and the hypothalamo-pituitary-testicular axis in the rat.

Several experiments have been performed in order to clarify the mechanisms through which aging in male rats brings about profound modifications of the neuroendocrine system (reduced pulsatile secretion of LH and FSH, decreased serum levels of gonadotropins and testosterone, etc.). (1) It has been found that the number of mu opioid receptors decreases significantly in the hypothalami of old male rats; the substitution therapy with testosterone is ineffective in increasing the number of mu opioid receptors. These data suggest that the decrease of hypothalamic mu opioid receptors is not due to a decline of serum testosterone levels, but appears to be an independent phenomenon. (2) K opioid receptors increase significantly in the amygdala and in the thalamus of old male rats. These results show that aging, in addition to mu receptors, affects also the number of K receptors in selected areas of the brain. The increase of the number of K receptors in the amygdala might have some bearing on the decrease of serum gonadotropins observed in aged rats, since the amygdala is involved in the nervous circuitry influencing the hypothalamo-pituitary-gonadal axis. (3) The study of the release of LHRH from the hypothalamus of old male rats with an in vitro perfusion system shows that the release of the hormone is comparable in young and old animals, both in basal and in K+ stimulated conditions. These results indicate that the hypothalamus of old male rats retains the capacity of releasing LHRH both in basal and in stimulated conditions. (4) It has been observed that the number of LHRH receptors at the level of the anterior pituitary is significantly reduced in old male rats. This finding might explain the low serum levels of gonadotropins and testosterone in aged rats, due to a lack of an adequate response of the pituitary to hypothalamic LHRH.

Aging↗
PubMed1987

Effect of oestrus cyclicity on the number of brain opioid mu receptors in the rat.

The present experiments have been performed in order to analyse whether the binding characteristics of brain opioid receptors of the mu type vary during the different phases of the oestrous cycle in the female rat. To this purpose different groups of females with a regular 4-day oestrous cycle were killed by decapitation in different phases of their oestrous cycle, i.e. at 10.00 and 16.00 h of the first and second day of dioestrus, at 10.00, 12.00, 14.00, 16.00 18.00 and 20.00 of the day of pro-oestrus, and at 10.00, 12.00 14.00, 16.00 and 18.00 of the day of oestrus. The total brains, after discarding the cerebellum, were homogenized and crude membrane preparations were obtained. On these preparations the maximal binding capacity (Bmax, index of the number of receptors) and the constant of affinity (Ka) for dihydromorphine, a typical ligand of mu opioid receptors were evaluated. Serum concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin were measured by specific radioimmunoassays in order to exactly ascertain the different phases of the oestrous cycle. The results obtained show that the number of mu opioid receptors in the whole brain presents significant changes during the different phases of the oestrous cycle. In particular, an increase in the concentration of these receptors was observed at 12.00 h of the day of pro-oestrus and at 18.00 h of the day of oestrus; these fluctuations of the number of mu receptors were not accompanied by any change of their affinity for the ligand.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Further evidence that gonadal steroids do not modulate brain opiate receptors in male rats.

It is still unclear whether, in the male rat, castration and androgen replacement affect the binding characteristics of brain opiate receptors. To clarify this issue, the effects exerted by orchidectomy and testosterone (T) replacement on the subpopulation of brain mu opiate receptors were studied in male rats; testosterone was administered via subcutaneous Silastic capsules. Utilizing 3H-dihydromorphine (a mu receptor ligand) it has been shown that the affinity constant (Ka) of brain mu opiate binding sites, measured in plasma membrane preparations, is not affected by castration. When mu receptor concentrations were measured in individual brains, it was found that gonadectomy and T replacement failed to produce any change in the number of mu opiate receptors. These data suggest that, in male rats, gonadal steroids do not develop their central feedback effects by affecting brain mu opiate receptors.

Animals↗
PubMed1986

Stimulatory and inhibitory effects of the opioids on gonadotropin secretion.

In order to gain additional information on the role played by the opioids in the control of the secretion of anterior pituitary gonadotropins, morphine (an opioid agonist) and naloxone (an opioid antagonist) have been injected intraventricularly (i.v.t.) into normal or castrated male rats. The animals were killed by decapitation at different time intervals after treatment and serum luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin were measured by radioimmunoassay. Animals injected i.v.t. with 0.9% saline solution and sacrificed at the same time intervals served as controls. When morphine (at the dose of 200 and 400 micrograms/rat) and naloxone (at the dose of 7.5 and 15 micrograms/rat) were injected i.v.t. into normal male rats, a significant increase of serum levels of LH was observed 10 and 20 min after injection. There was no effect at 5, 40 and 60 min. Lower doses of morphine (6.25, 12.5, 25, 50 and 100 micrograms/rat) given i.v.t. were ineffective. When morphine (200 micrograms/rat) and naloxone (either in the dose of 7.5 micrograms/rat or of 15 micrograms/rat) were given simultaneously, serum LH was significantly higher than in the saline-treated controls both at 10 and 20 min. However, the increases of serum LH levels induced by the combined treatment were in both instances lower than those produced by the administration of either drug alone. Morphine (200 micrograms/rat) when administered i.v.t. to normal male rats significantly enhanced prolactin release at 10 and 20 min, and this effect of morphine was blunted by the concomitant i.v.t. administration of naloxone (7.5 and 15 micrograms/rat).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Role of arachidonate metabolism on the in vitro release of luteinizing hormone and prolactin from the anterior pituitary gland: possible involvement of lipoxygenase pathway.

The aim of the present study was to evaluate whether arachidonic acid metabolism may play a role on luteinizing hormone (LH) and prolactin (PRL) release directly at the pituitary level. To this purpose, exogenous arachidonic acid, alone or in presence of inhibitors of cyclooxygenase (indomethacin:IND) and lipoxygenase pathways (nordihydroguaiaretic acid:NDGA), was added to perfused rat anterior pituitary cells. PGE, PGF alpha, LH and PRL levels present in the eluate were assayed with specific RIA methods. Both PGE and PGF alpha show a dose-related response after the addition of increasing doses of arachidonic acid. The addition of 0.05 mM arachidonic acid induces an increase of LH and PRL. The addition of IND to the perfusion medium highly potentiates the stimulatory effects induced by arachidonic acid on LH and PRL release. On the contrary, the addition to the medium of either NDGA or IND plus NDGA completely reverses the stimulatory action induced by arachidonic acid alone. The present results suggest that: adenohypophyseal cells are able to metabolize exogenous arachidonic acid; arachidonic acid induces an elevation in LH and PRL levels; lipoxygenase pathway metabolite(s) are likely involved in these activities, and the site of action of arachidonic acid is at the pituitary level.

Animals↗