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Biomedical subjects

G Maira

Publications and source records attributed to G Maira.

At least 91 records · Page 5Linked to original sources
PubMed1979

Prolactin-secreting pituitary adenomas: prolactin dynamics before and after transsphenoidal surgery.

Twenty women with hyperprolactinaemia secondary to a pituitary adenoma were studied before and after selective transsphenoidal removal of the tumour. Pre-operatively, thyrotrophin-releasing hormone (TRH) (200 micrograms iv) and metoclopramide (MCP) (10 mg po) did not produce a positive PRL response in the tumour patients. By contrast, 14 post-partum lactating women, who were used as controls, exhibited a positive response to MCP administration. Methergoline (4 mg po) was shown to decrease serum PRL levels in 8 normal subjects, in 6 puerperal women, and 9 of 10 tumour patients. Bromoergocriptine (CB-154, 2.5 mg po) decreased serum PRL levels in 10 tumour patients. Following transsphenoidal removal of the adenoma serum PRL levels were reduced in all patients, and returned to normal in 14 patients. Prognostics for completely normalizing PRL secretion after transsphenoidal surgery is bettery when initial serum PRL levels are below 200 ng/ml. After surgery all hyperprolactinaemic patients failed to show a positive PRL response to TRH and MCP. Nine normoprolactinaemic patients had a positive response to both stimuli while 3 patients failed to show a positive response immediately following surgery. Long-term studies, however, showed that a positive PRL response was obtained in all patients tested 8-14 months after treatment. A positive PRL response to methergoline and bromocriptine was observed post-operatively in the patients tested regardless of their basal PRL level. Data from this study indicate that surgically proven PRL-secreting adenomas are invariably associated with negative PRL responses to TRH and MCP. The normalization of the prolactin regulation after surgery points toward the intrapituitary localization of the lesion associated with PRL-secreting adenomas.

Adenoma↗
PubMed1978

The value of CT for the diagnosis of pituitary microadenomas in children.

Three cases of prepuberal hypopituitary dwarfism regarded as idiopathic, are reported. In two of them the skull X-rays showed questionable minimal alterations of the sella turcica; in the remaining child the examination was completely negative. All three children were found to have a pituitary intrasellar microadenoma on the CT scan. The diagnosis was confirmed during surgery. The postoperative followup demonstrated the relation of the lesion with growth retardation and the indication for surgical treatment.

Adenoma, Chromophobe↗
PubMed1978

Serum prolactin response to thyrotropin-releasing hormone and metoclopramide in patients with prolactin-secreting tumors before and after transsphenoidal surgery.

Seven female patients with amenorrhea, galactorrhea, and hyperprolactinemia were examined before and after selective transsphenoidal removal of a PRL-secreting microadenoma. Before adenomectomy, metoclopramide (MCP; 10 mg orally) and TRH (200 micrograms iv) did not increase PRL blood levels in any of the seven patients. On the contrary, after oral administration of 10 mg MCP, a positive response was noted in a group of eight lactating women 3 days postpartum. After surgery, serum PRL level returned to normal in all patients. A positive PRL response to MCP and TRH was found in six of the seven patients 1 month after surgery. One patient, who had the lowest PRL level, failed to show a PRL increase after both stimuli. These findings indicate that hypothalamic pituitary function can be restored to normal after transsphenoidal removal of PRL-secreting pituitary tumors.

Adenoma↗
PubMed1977

Anatomo-clinical correlations in normotensive hydrocephalus. Reports on three cases.

The brains of 3 adult subjects suffering from normotensive hydrocephalus have been examined pathologically. The diagnosis of normotensive hydrocephalus was based on clinical symptoms, pneumoencephalography and isotope cisternography, in 1 case integrated with the results of the constant-infusion manometric test. Part of the neuropathological findings were common to the 3 patients: leptomeningeal non-obstructive fibrosis, ventricular ependymal disruption, subependymal glial reaction, periventricular demyelination and spongiosis. Other neuropathological abnormalities were peculiar to each patient: leptomeningeal signs of previous subarachnoid haemorrhage; arteriosclerosis and multiple brain cystic infarcts; Alzheimer's plaques in the gray matter. The possible pathogenetic significance of the neuropathological findings summarized above in relation to the development of normotensive hydrocephalus is discussed.

Adult↗
PubMed1977

The study of cerebrospinal fluid dynamics in apparently 'arrested' hydrocephalus in children.

18 children having hydrocephalus, which could be regarded clinically as 'arrested', underwent cerebral angiography and a constant infusion manometric test. Intracranial pressure was directly recorded in 3 cases. The above examinations indicated that hydrocephalus was still 'active' in 8 children. This was confirmed by the good results of the surgical treatment.

Cerebral Ventriculography↗
PubMed1976

Surgical indications in normotensive hydrocephalus. A retrospective analysis of the relations of some diagnostic findings to the results of surgical treatment.

Twenty two of fifty five patients initially suspected of suffering from normotensive hydrocephalus were surgically treated (CSF ventriculoatrial shunt). The results of surgery were related to the findings of the different diagnostic examinations (pneumoencephalography, isotope cisternography, transfer fron CSF to blood of isotope labelled serum albumin, constant infusion manometric test, long lasting intraventricular pressure recording). 1.Pneumoencephalography, intraventricular pressure recording, and, above all, isotope cisternography provided the most reliable data for diagnosis and surgical prognosis. 2. The combined use of pneumoencephalography and isotope cisternography was sufficient for a correct diagnosis and surgical prognosis in about 50% of the patients examined. 3. When the diagnostic information given by the combined results of the two above examinations was not sufficient, intraventricular pressure recording proved to be the most useful examination to supplement it. 4. The relation of the results of the study of transfer of istope labelled serum albumin from CSF to blood and of the constant infusion manometric test to the surgical outcome was uncertain.

Adult↗
PubMed1976

Cerebrospinal fluid pressure studies in normal pressure hydrocephalus and cerebral atrophy.

The surgical results obtained with a cerebrospinal fluid (CSF) shunt operation in 13 patients considered to be suffering from normal pressure hydrocephalus have been correlated with the findings of the constant manometric infusion test (IT) and of prolonged intracranial pressure recordings. A positive IT, high amplitude CSF pulse pressure and large transitory increases of CSF pressure during sleep seem to be useful criteria for the surgical prognosis. Ten more patients affected by primary cerebral atrophy have also been studied. The data obtained in both groups of patients have been utilized for a possible pathogenetic interpretation of the syndrome.

Adult↗
PubMed1975

Monoamine acid metabolites and cerebrospinal fluid dynamics in normal pressure hydrocephalus: preliminary results.

Lumbar and ventricular CSF concentration of homovanillic acid (HVA) and 5-hydroxy-indole-acetic acid (5-HIAA) have been determined in 13 patients admitted to hospital for suspected normal pressure hydrocephalus. Low values of HVA in lumbar CSF were found in all patients with reduced CSF absorption and CSF flow inversion. The HVA lumbar concentration remained low after shunt procedure; it increased if obstruction of the shunt occurred. The ventricular CSF concentration of HVA was normal before surgery; it became higher, in two cases, after surgery. No important variations were found in the lumbar and ventricular CSF concentration of 5-HIAA. The possible mechanisms and diagnostic value of these findings are discussed.

Adult↗
PubMedDate not supplied

Laser photocoagulation for treatment of experimental aneurysms.

Twenty-five autologous, artificially implanted venous and arterial aneurysms were treated by argon laser photocoagulation. Sequential angiographic follow-up studies and final histologic studies demonstrated complete secondary occlusion in 11 cases, significant reduction of the aneurysm lumen in 10 cases, and no change in 4 cases. Delayed secondary occlusion appears to involve an active biologic process with progressive fibroblastic proliferation in the aneurysm wall.

Animals↗
PubMedDate not supplied

Pituitary microadenomas in children: a cause of growth failure.

Six children, originally regarded as being affected by prepubertal idiopathic growth failure, were found to have pituitary microadenomas. In all six patients, the growth failure (less than or equal to 2 cm/yr) was the primary clinical sign, and was accompanied by a growth hormone deficiency that was discovered during the laboratory evaluation. Prominent alteration of the sella turcica was not demonstrated in the skull x-ray examinations of any of the children, even when the x-ray examinations were supplemented by hypocycloidal tomography. CT scanning proved to be a very useful integrating diagnostic procedure, revealing the adenoma to be a nodular area of increased density within the sella turcica. In all of the children, resumption of normal growth was obtained following the surgical removal of the tumor through a transsphenoidal approach.

Adenoma↗
PubMedDate not supplied

Intracerebral diffusion of paramagnetic cationic liposomes containing Gd(DTPA)2- followed by MRI spectroscopy: assessment of pattern diffusion and time steadiness of a non-viral vector model.

Cationic liposomes are generally considered as the non-viral counterparts of the more common viral vectors used in several gene therapy protocols, but their use as delivery vehicles is limited by their efficiency even if they display a lower toxicity. However, cationic liposomes are promising delivery systems in cell biology due to their ability to incorporate small molecules into their inner aqueous spheres and to deliver them into cells. Additionally, on the external surface they can bind therapeutic molecules such as nucleic acids, oligonucleotides, plasmids, etc. through electrostatic interactions. The aim of this work was to study the diffusion properties of such vehicles in vivo with a non-invasive technique and to monitor their tissue migration in order to collect information to be further used in gene therapy procedures. For this purpose, cationic liposomes containing the paramagnetic contrast agent Gd(DTPA)2- (Gd(III)-diethylenetriamine-N,N,N',N",N"-pentaacetic acid) were investigated because of their extended paramagnetic persistency in vivo, compared to the use of the contrast agent alone, and they were used to monitor the diffusion of such vehicles in an animal model (rat model). In particular, these vectors were injected into the rat brain through a stereotactic frame in a preformed cavity mimicking the lesion which had originated after surgical removal of the primary tumor. For the purpose of comparison, the same injection procedure was also applied to a control series of animals without a preformed brain lesion. Pattern diffusion and steadiness of the reported paramagnetic cationic liposomes were studied by means of Magnetic Resonance Imaging (MRI) which allowed us to monitor their diffusion and assess their intracerebral time availability up to 24 hours.

Animals↗
PubMedDate not supplied

[Violence in the family: Ecuadorian experience in the formulation of policies for health services].

Since 1995, PAHO has been carrying out in Bolivia, Ecuador, and Peru a project known as "Violence against Women and Girls: Proposal to Establish Community-coordinated Interventions in Three Countries of the Andean Subregion." Its purpose is to support initiatives being conducted by various nongovernmental organizations (NGOs), government agencies, and social institutions in an attempt to improve the status of women. One of its objectives is to formulate public policies and local services aimed at preventing and combating violence against women and girls through local action networks, data-gathering systems, and legal proposals. This article examines what the initiative has achieved so far in Ecuador, in efforts conducted in Quito, Guayaquil, and Sigsig with the support of three national NGOs and in conjunction with the Ministry of Health and the National Women's Council.

Adolescent↗
PubMedDate not supplied

Results of [131I]metaiodobenzylguanidine treatment in metastatic malignant phaeochromocytoma.

The results obtained with [131I]metaiodobenzylguanidine (131I-MIBG) treatment in 6 patients affected by metastatic phaeochromocytoma are reported. Single doses of 3.7-7.4 GBq were given, in 1-6 courses, up to cumulative doses of 5.4-37.8 GBq. Objective responses were observed in 5 patients (2 tumour shrinkages, even if small; 5 lowering of blood pressure), which were only temporary in 3 patients and stable in 2. Complete disappearance of pain was obtained in 2/2 patients. No adverse side-effects were observed. The problem of treatment strategy in situations of stable disease deserves further study.

3-Iodobenzylguanidine↗