PubMed Health⌕ Search

Biomedical subjects

G Marchini

Publications and source records attributed to G Marchini.

At least 37 records · Page 2Linked to original sources
PubMed1996

Pulsatile release of oxytocin in newborn infants.

Recently, a pulsatile, basal oxytocin blood level has been described in human adults. To investigate if such a hormone profile exists already during the neonatal period, we collected blood samples continuously with 20-s fractions for 4 min in 1-day-old infants (n = 26). Plasma oxytocin concentrations were determined by a specific radioimmunoassay. The values were further analysed by the pulse detection program PULSAR. We found that 42% of the infants presented one peak in the oxytocin level during a 4-min period. The peak constituted a 111 +/- 66% (mean +/- SD) increment of the baseline value. It is suggested that the release of oxytocin during basal conditions occurs in a pulsatile way in newborn infants and that these hormone pulses reflect fluctuations in the activity of the hypothalamic neurosecretory cells.

Female↗
PubMed1996

Gamma Knife stereotactic radiosurgery for uveal melanoma: clinical results after 2 years.

We report on 36 cases of uveal melanoma treated at our center between March 1993 and September 1995. There were 16 men and 20 women, aged 57 +/- 11 years. The choroid was affected in 35 patients and the ciliary-body in 1. The same preoperative and follow-up protocol was adopted for all cases. The procedure included fixation and positioning of the eye with a retrobulbar injection of long-lasting anesthetic and two extraocular muscle sutures, application of the frame, computed tomography scan localization, dose planning and treatment with the Gamma Knife. The patients were divided into three groups. Group A: 10 patients with a follow-up of 24 +/- 4 months, treated with a high dose (surface dose 58 +/- 9 Gy, maximum dose 81 +/- 15 Gy, mean dose 66 +/- 11 Gy). Group B: 9 patients with a follow-up of 16 +/- 2 months, treated with a lower dose (surface dose 41 +/- 3 Gy, maximum dose 76 +/- 10 Gy, mean dose 53 +/- 11 Gy). Group C: 17 patients with a follow-up of 6 +/- 3 months, treated with a lower dose (surface dose 42 +/- 3 Gy, maximum dose 72 +/- 16 Gy, mean dose: 54 +/- 6 Gy). In group A, we observed marked tumor regression in 9 cases, tumor recurrence in 1 case and severe complications in 5 cases (neovascular glaucoma and/or radiation retinopathy and/or radiation optic neuropathy). In group B, significant local control of the tumor was obtained with minor complications (cotton wool spots hard exudates, intraretinal hemorrhages). In group C, to date we have observed a regression of the tumor in 7 cases and 1 severe complication (neovascular glaucoma). Our data show that uveal melanomas may be adequately controlled by a high radiosurgical dosage (50-70 Gy), though there are significant side effects. Comparable levels of local tumor control may be obtainable using lower doses (40-45 Gy) which would hopefully reduce the rate of complications. However, a longer follow-up is needed for further validation of these results.

Aged↗
PubMed1995

HPR perimetry and Humphrey perimetry in glaucomatous children.

Fifteen children aged less than 11 years, affected by congenital glaucoma, underwent visual field testing using two different methods: conventional computerized perimetry (24-2 Humphrey program) and High Pass Resolution perimetry (Ring test). The aim of the study was to discover which of the two perimetric techniques was more suitable for younger patient. Results showed that HPR perimetry is more suitable to children. Reasons include the short duration of the test (5 min), and the appearance like a pleasant game to 80% of the subjects tested. In addition it proved to be better than Humphrey test because of the minimal possibilities of memorisation with a reproducibility factor of 68% in our sample and because of the reliable results and satisfactory evaluation in 76% of the eyes examined.

Child↗
PubMed1995

Ultrasonographic findings in endophthalmitis.

Ultrasonographic findings are reported in 7 cases of endophthalmitis (6 of bacterial and 1 of fungal origin) resulting from perforating injuries (2 cases), severe corneal ulcers (2 cases) and open-eye surgery (3 cases). The most frequent ultrasonographic picture was characterized by a series of low reflectivity echoes in the vitreous with a high degree of mobility (7/7), fairly large endovitreal vacuoles (3/7) and hyaloid thickening (3/7). In one case the vitreous involvement was confined to only one quadrant. Choroidal thickening both of a homogeneous-diffuse (2/7) and nodular-multifocal type (3/7) was found. Localized choroidal detachment (1/7) and exudative pre-equatorial retinal detachment (1/7) were detected in only two cases. Ultrasonography proved useful both for detecting involvement of the posterior segment and for monitoring the time course of the infection process.

Adult↗
PubMed1995

Influence of body temperature on thyrotropic hormone release and lipolysis in the newborn infant.

The present study investigated possible interactions between body temperature, lipolysis and thyrotropin (TSH), the only hormone with a documented lipolytic effect in vitro in newborn infants. Healthy infants were either nursed in the usual way (n = 18) or protected from a decrease in body temperature (n = 17) during the first postnatal hour. The infants' axillary temperatures were measured immediately after birth and after 10 and 60 min. Blood samples were collected from the umbilical vein and from the infants 10 and 60 min after birth for analysis of TSH, glycerol, free fatty acids, 3-OH-butyric acid and glucose. We found that the mean (+/- SD) infant axillary temperature was 37.6 +/- 0.4 degrees C immediately after birth. In the routinely nursed infants, body temperature decreased to 37.0 +/- 0.5 degrees C at 10 min (p = 0.01) and to 36.6 +/- 0.4 degrees C at 60 min (p = 0.01); the cold-protected infants maintained their fetal temperature at 60 min of age. There was a four-fold increase in plasma TSH levels at 10 min, independent of the infant's body temperature, and the hormone level remained invariably high at 60 min. Plasma glycerol levels increased progressively at 10 min (p = 0.01) and 60 min (p = 0.01) in both infant groups, but were higher (p = 0.02) in the routinely nursed infants at 60 min. No significant relationship was found between TSH and glycerol levels. Infant body temperature did not affect the levels of free fatty acids, 3-OH-butyric acid or glucose. We conclude that the change in environmental temperature as a result of extrauterine adaptation causes thermal stimulation of the infant's body surface which leads to activation of the hypothalamic-pituitary TSH axis, resulting in maximal TSH release, and thus to induction of the lipolytic process. A decrease in body temperature may be an additive stimulus for further enhancement of lipolysis.

Body Temperature↗
PubMed1995

Gamma Knife radiosurgery of primary and metastatic malignant brain tumors, a preliminary report.

Between February 1993 and March 1994, 75 metastases, 16 gliomas and 2 AIDS-related malignant lymphomas were treated with Gamma Knife radiosurgery. Metastatic brain tumors (54% lung cancer, 14% breast cancer, 13.5% melanoma) were the most frequent and clinically rewarding cases. So-called local control was achieved in almost all patients, the vast majority showing neurological improvement associated with radiological disappearance or dramatic shrinkage of the tumor within 9-12 weeks from treatment. According to our modified 'Pittsburgh' protocol, we have treated up to four distinct intracranial lesions, up to a total maximum volume of 20 cm3, with an average surface dose of 25 Gy, with or without additional whole brain radiotherapy (WBR). Preliminary follow-up data seem to confirm increased quality of life and survival rates. The results were particularly striking whenever primary tumors were under control, and were poorly influenced by associated WBR. Gamma Knife treatment was also performed in a selected group of patients with small-to-medium-sized, well-defined, histologically proven, cerebral gliomas. The main indications for radiosurgery were high-risk surgery, multifocal disease, ventricular seeding and unresected or recurrent tumor. The prescription doses ranged from 18 to 30 Gy, with a mean of 27 Gy. Low-grade astrocytomas (9/16 cases) showed the better clinical and radiological response to treatment, with neurological recovery and significant reduction in tumor volume within 3-5 months in 5 of the 9 patients. In 4 of 7 high-grade gliomas, there was little or no response. However, an impressive radiological regression with full clinical recovery was observed in 2 high-grade cases with small tumor volumes: a recurrent, anaplastic 'mixed glioma' of the pineal region and a double ventricular seeding of a previously operated anaplastic astrocytoma.

Brain Neoplasms↗
PubMed1995

Gamma Knife stereotactic radiosurgery of ocular metastases: a case report.

A case of a choroidal metastasis treated with Gamma Knife stereotactic radiosurgery is reported. A 48-year-old Caucasian man afflicted with lung cancer (adenocarcinoma) was referred to the University Hospital of Verona, Italy, for loss of vision in his left eye due to a choroidal mass with exudative retinal detachment. Clinical investigation was conclusive of a well-defined, bilobed choroidal metastasis located in the temporal and inferior portion of the posterior pole of the eye. The lesion was characterized by a maximum thickness of 5.2 mm and a maximum lateral extension of 14 mm. The staging was negative for other metastatic localizations. Using the Gamma Knife technique, a surface dose of 25 Gy was administered at the 50% isodose line using the 8-mm collimator (5 shots) with equally weighted fields. After a 3-month follow-up period, a marked reduction in the lesion size as well as in the exudative retinal detachment was observed. This improvement was unchanged 6 months after the treatment, and the lesion appeared completely controlled. To the best of our knowledge, this is the first case report of an ocular metastasis treated with stereotactic Gamma Knife radiosurgery.

Adenocarcinoma↗
PubMed1995

Stereotactic radiosurgery of uveal melanomas: preliminary results with Gamma Knife treatment.

Twelve cases of uveal melanoma (T3N0M0:11 patients, T4N0M0:1 patient) treated with Gamma Knife stereotactic radiosurgery are reported. Our protocol includes preoperative ocular and systemic assessments with complete ocular examination, ophthalmoscopy, fundus photography, fluorangiography, standardized echography, CT and MRI, chest X-rays, liver echography and blood tests. The follow-up program is mainly based on echographic evaluation of tumor thickness and size. The procedures include fixation of the eye, application of the stereotactic Leksell frame G, CT/MRI localization of the melanoma, dose planning and treatment with the Gamma Knife (B type). A mean surface dose of 55 +/- 10 Gy was administered at the 60-90% isodose curve using 4- to 14-mm collimators and a number of shots ranging from 1 to 6. A significant reduction (10-41%) in echographic thickness of the tumor was shown in 6 cases with a follow-up of 3-12 months. In 4 patients, the tumor size was still unchanged after 1-10 months. The single high-dose radiation delivered to the target and the high spatial accuracy are the main advantages of stereotactic radiosurgery for the treatment of posterior uveal melanomas. A longer followup is needed to further validate this new application of Gamma Knife radiosurgery.

Adult↗
PubMed1995

A euristic approach to the volume reconstruction of arteriovenous malformations from biplane angiography.

Three-dimensional (3D) volume reconstruction is easily feasible with axial, coronal or sagittal CT and MRI scans. On the other hand, radiosurgical treatment of arteriovenous malformations (AVMs) is exclusively based on two orthogonal stereotactic projections, obtained with angiographic procedures. Most commonly AVM volumes have been calculated by assimilating the nidus volume to a prolate ellipsoid. We present an algorithm dedicated to 3D volume reconstruction starting from two stereotactic orthogonal projections. This has been achieved using a euristic approach which has been widely adopted in the artificial intelligence domain. Tests on phantoms of different complexity have shown excellent results. The importance of the algorithm is considerable. Firstly, it allows calculations of complex structures far removed from a regular ellipsoid. Secondly, it permits shape recovery. Thirdly, it provides AVM visualization on axial planes.

Algorithms↗
PubMed1995

[Evaluation of the action of glucomannan on metabolic parameters and on the sensation of satiation in overweight and obese patients].

The authors studied the behavior of body weight, blood glucose, total serum cholesterol, and hunger and satiety sensation in 30 patients treated for 60 days with a 1.200 kcal (5040 kj) diet plus either placebo or glucomannane. All the variables considered show that the low-calorie diet plus glucomannane is more effective than the low-calorie diet alone.

Adult↗
PubMed1994

Plasma gastrin and somatostatin levels in newborn infants receiving supplementary formula feeding.

Plasma gastrin and somatostatin concentrations were measured by radioimmunoassay in exclusively formula-fed infants and in breast-fed infants receiving supplementary formula during the first five postnatal days. Infants exclusively formula fed had a progressive increase in mean plasma gastrin concentration from 109 +/- 42 pmol/l (mean +/- SD) on the first day to 236 +/- 103 pmol/l on the fifth day after birth (p = 0.0001). Breast-fed infants receiving supplementary formula had similar hormone concentrations as formula-fed infants of corresponding postnatal age and they also had a significant increase in hormone levels from the first to the fifth day (p = 0.0001). A positive relationship was found between gastrin concentration and ingested milk volume: Rs = 0.51, n = 105, p = 0.0001. The high gastrin concentrations most probably reflect enhanced hormonal release from the gastrin-producing cells in response to increasing volumes of milk ingested by the infant. The mean plasma somatostatin concentration on the first day after birth was 18 +/- 6 pmol/l. No significant change occurred during the first five postnatal days, independent of feeding type.

Female↗
PubMed1993

The relationship of plasma cholecystokinin levels to different feeding routines in newborn infants.

Plasma cholecystokinin concentrations were measured with radioimmunoassay in breast fed infants in Sweden (n = 101) and formula fed infants in Italy (n = 119). Blood samples were collected from the infants during the first five postnatal days, just before feeding in a cross-sectional way. We found no significant difference in the hormone concentration in relation to age, in breast fed or in formula fed infants. Breast fed infants had significantly higher plasma hormone concentrations than formula fed infants during the postnatal period 0-5 days: 2.8 pmol/l (1-10 pmol/l), median (range) versus 2.2 pmol/l (1-25 pmol/l), (P < 0.02). It cannot be excluded that the results were influenced by the circumstances that the samples were collected from two separate populations. However, the higher hormone levels in breast fed infants may also be the expression of the fact that natural feeding per se promotes cholecystokinin secretion in newborn infants.

Breast Feeding↗
PubMed1993

Metabolic correlates of behaviour in the newborn infant.

Twenty-four infants were submitted to behavioural observation 0.5 and 3.5 h after birth. Blood samples were collected from the umbilical cord and from the infant immediately following observation, for the determination of glucose, insulin, cholecystokinin (CCK), and free fatty acids (FFA). It was found that 88% of the infants were awake and 83% performed sucking movements 0.5 h after birth; these findings were associated to a decrease in the plasma glucose concentration (p = 0.05). Eighty-eight percent of the infants were asleep and only 12% exhibited sucking movements 3.5 h after birth; at this time point there was an increase in the plasma concentrations of both CCK (p = 0.05) and FFA (p = 0.01). The infants' plasma insulin concentrations remained unchanged during the time course. It is suggested that the initial behavioural pattern of the newborn, characterized by the appearance of sucking movements, may be due to the rapid decrease of the circulating glucose concentration. The successive increase in the blood concentrations of both CCK and FFA might be two of the factors contributing to the cessation of sucking and to the establishment of a sleeping state.

Arousal↗
PubMed1993

Plasma cholecystokinin concentrations after breast feeding in healthy 4 day old infants.

The aim of the present study was to characterise plasma concentrations of cholecystokinin (CCK) after breast feeding in newborn infants. Fifty eight healthy full term exclusively breast fed infants were investigated at 4 (1) (2-6) days of age. Each infant contributed one blood sample collected just before, immediately after, or 10, 30, and 60 minutes after breast feeding. Plasma concentrations of CCK were measured with a technique consisting of high pressure liquid chromatography separation of gastrins and CCKs and consequent analysis with radioimmunoassay. Mean (SD) preprandial plasma concentrations of CCK (CCK8+CCK-33,39) were 68 (17) pmol/l. A significant increase was seen immediately after breast feeding, which was followed by a decline at 10 minutes and a secondary rise was seen at 30 and 60 minutes. The first peak is likely to be due to a suckling related activation of the vagal nerve and the second to a stimulatory effect of food on CCK-producing cells. An inverse relationship between basal concentrations of CCK and age of the infant was found. In rats peripheral injections of CCK reduce food intake and cause postprandial sedation and sleepiness via activation of an afferent vagal mechanism. CCK release in response to breast feeding may therefore in addition to exerting stimulatory effects on digestion and metabolism contribute to relaxation and sleepiness seen after breast feeding. The high CCK concentrations seen in younger infants may help the infant to remain satiated and calm despite receiving very little food during the first days of life.

Birth Weight↗
PubMed1992

Effects of the association of alpha and beta-blocking agents in glaucoma.

Twenty patients with POAG and early visual field changes, already under treatment with 0.5% timolol were randomly assigned to additional topical treatment with 0.5% dapiprazole or placebo. After six months of treatment no differences were observed between the groups for what concerns visual field. After six months of treatment visual field, visual flicker discrimination and contrast sensitivity proved to be constant without differences between the groups. On the contrary, mean IOP was found to be significantly lower in the dapiprazole group.

Adrenergic alpha-Antagonists↗
PubMed1992

Plasma gastrin-34 increases during and immediately after breast-feeding in 3-day-old infants.

We examined whether plasma gastrin concentration increases during breast-feeding in infants. The peptide concentration was measured cross-sectionally before, during, and after breast-feeding in healthy, 3-day-old infants (n = 72). Somatostatin, a modulator of gastrin release, was also analyzed. Both peptides were measured by radioimmunoassay and were further characterized by high-performance liquid chromatography (HPLC). The (mean +/- SD) concentration of gastrin rose significantly from 63 +/- 24 pmol/L before feeding to 92 +/- 32 pmol/L (p less than 0.01) and 95 +/- 21 pmol/L (p less than 0.01), 5 and 10 min after the initiation of sucking, respectively. The gastrin concentration was 102 +/- 35 pmol/L (p less than 0.01) immediately after feeding. Plasma somatostatin concentration was unaffected by feeding. As assessed by HPLC, circulating gastrin before, during, and after feeding was found to correspond to gastrin-34, whereas circulating somatostatin was found to correspond to somatostatin-14. We conclude that in contrast to earlier studies, plasma gastrin concentration increases during and immediately after breast-feeding in infants.

Birth Weight↗
PubMed1992

Levels and molecular forms of gastrin and somatostatin in plasma and in gastric contents of infants after section delivery.

We measured the pH of the gastric contents, as well as the gastrin- and somatostatin-like immunoreactivity in both plasma and gastric content samples, obtained from 23 infants delivered at term by elective cesarean section (ECS). In addition, we characterized the molecular forms of gastrin and somatostatin by high performance liquid chromatography. The median pH value of the gastric contents was found to be 6.78 (range 4.93-7.35). The median gastrin concentration in plasma was 54 pmol/L (range 29-190 pmol/L), which was significantly higher (p less than 0.0005) than the concentration recorded in the gastric contents, 6 pmol/L (range 0-680 pmol/L). The median somatostatin concentration in plasma was 12 pmol/L (range 4-40 pmol/L), which was significantly lower (p less than 0.0001) than the concentration found in the gastric contents, 128 pmol/L (range 15-488 pmol/L). Gastrin- and somatostatin-like immunoreactivity in both plasma and gastric contents were found to correspond to nonsulfated gastrin-34 and somatostatin-14, respectively. These data suggest that acid secretion is absent or low in infants immediately following ECS, although gastrin and somatostatin are being released into the circulation as well as into the gastric lumen. The different ratio between the concentration in plasma and gastric contents of gastrin (10:1) compared with that of somatostatin (1:10) might be related to the fact that gastrin exerts endocrine actions preferentially, whereas somatostatin is presumed to exert local paracrine effects on the gastric mucosa.

Adult↗