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Biomedical subjects

G Zamboni

Publications and source records attributed to G Zamboni.

At least 109 records · Page 6Linked to original sources
PubMed1994

Clear cell ("sugar") tumor of the lung is a lesion strictly related to angiomyolipoma--the concept of a family of lesions characterized by the presence of the perivascular epithelioid cells (PEC).

We report a comparative study of 3 clear cell tumors of the lung (CCTL) and 3 angiomyolipomas (AML) of the kidney. Morphological analysis shows that the cells of CCTL are identical to the perivascular epithelioid component of AML. Phenotypically they both consistently expressed melanoma-associated antigens recognized by Moabs HMB45 and HMSA-1, while they were negative for HMSA-5. A minority of cells also expressed S-100 protein, vimentin and actin. In addition, one case of CCTL showed mature adipose tissue entrapped in the proliferation, thus suggesting an intermediate form between CCTL and AML. Based on morphological and phenotypical similarities, it is suggested that CCTL and AML belong to the same family of lesions, characterized by the presence of a peculiar muscle cell, expressing different melanoma-associated antigens.

Adult↗
PubMed1994

Pattern of desynchronized sleep during deprivation and recovery induced in the rat by changes in ambient temperature.

The pattern of desynchronized sleep (DS) occurrence in the rat was studied during exposure to an ambient temperature (Ta) of 0 degrees C for 48 h and during a 12 h recovery period at laboratory Ta (23 degrees C) following the first and second 24 h of cold exposure. The exposure to low Ta induces a DS deprivation which is followed, during recovery, by a clear DS rebound. Both the decrease and the following increase in the amount of DS are due to changes in the frequency rather than in the duration of DS episodes. The frequency distribution of the intervals between the end of one DS episode and the beginning of the next (DS interval) has shown that two populations of DS intervals exist, i.e. short DS intervals (</=3 min) and long DS intervals (>3 min). On the basis of this, two types of DS episodes have been identified: the 'single DS episode', which is both preceded and followed by a long DS interval, and the 'sequential DS episode', which is a DS episode occurring within a cluster or a sequence of DS episodes and is characteristically separated by short DS intervals. The occurrence of such sequential DS episodes in a 'DS cluster', allows a high amount of DS to occur without increasing the duration of the DS episode. DS clusters are repressed during cold exposure, when the DS drive is counteracted by the need to thermoregulate, and enhanced during recovery, when the DS drive is unrestrained. In contrast, the occurrence of single DS episodes is much less affected by such different experimental conditions.

Journal Article↗
PubMed1994

Final height in girls with central precocious puberty: comparison of two different luteinizing hormone-releasing hormone agonist treatments.

In order to evaluate the effects of two long-acting luteinizing hormone-releasing hormone agonists on growth, bone maturation and final height in girls with central precocious puberty, we analyzed growth data from 40 girls (15 treated with buserelin intranasal spray (group A), 15 treated with triptorelin depot im every 28 days (group B) and 10 untreated (group C)). Patients in group A started treatment when chronological age (CA) was 7.7 +/- 0.9 years, bone age (BA) was 10.2 +/- 1.1 years and height was 131.9 +/- 5.0 cm. Patients in group B started therapy when CA was 7.6 +/- 0.5 years, BA 9.8 +/- 1.0 years and height 133.2 +/- 7.6 cm. The diagnosis of untreated patients (group C) was made when CA was 7.2 +/- 0.9 years, BA 9.6 +/- 2.2 years and height 130.2 +/- 8.6 cm. Both luteinizing hormone-releasing hormone agonists appeared to control precocious puberty. Final height in group B (160.6 +/- 5.7 cm) was significantly higher than that of group A (153.2 +/- 5.0 cm: p < 0.05) and group C (149.6 +/- 6.3; p < 0.01), whereas the difference between groups A and C was not statistically significant. In group B a positive difference was observed between final height (160.6 +/- 5.7 cm) and target height (157.6 +/- 5.9 cm) (ns); on the contrary, in groups A and C, final height was lower than target height (155.5 +/- 5.3 and 156.4 +/- 1.3 cm, respectively), but only in group C the difference was statistically significant (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Intranasal↗
PubMed1994

Retroperitoneal paragangliomas: role of immunohistochemistry in the diagnosis of malignancy and in assessment of prognosis.

OBJECTIVE: To present our experience of 10 patients with extra-adrenal retroperitoneal paragangliomas, and assess prognostic tests. DESIGN: Retrospective study of casenotes. SETTING: University hospital, Italy. SUBJECTS: 10 Patients who presented with paragangliomas between 1970 and 1991. MAIN OUTCOME MEASURES: Histological and immunohistochemical results, and outcome. RESULTS: All tumours were completely resected and there was no operative mortality. Of the 8 patients who had no metastases at presentation 3 died of recurrence 3, 5, and 10 years later, respectively; 4 were alive and free of disease 2-7 years after diagnosis. The 2 patients with synchronous bone metastases at presentation died 1 and 4 years later. Immunohistochemical analysis of type I cells (chromogranin A and neurone-specific enolase) showed little correlation with progression of disease, but there was a correlation between the presence of type II cells (S100 protein) and good prognosis. CONCLUSIONS: Excision is the treatment of choice for paraganglioma. Immunohistochemical techniques may provide useful information about prognosis, in particular about those patients who are at increased risk of recurrence. Long term follow up is essential, because successful management of recurrence is dependent on early recognition.

Adult↗
PubMed1994

[The therapy of congenital hypothyroidism].

In congenital hypothyroidism precocious diagnosis and consequent replacement therapy are necessary to prevent neurological irreversible damage caused by postnatal thyroid hormone deficiency. Synthetic L-thyroxine is the useful drug, that has to be administered in fasting condition to have the best absorption. Some points about the treatment are still discussed, such initial L-thyroxine dosage, biochemical control parameters and psycho-intellectual outcome in treated patients. The mean initial dosage in Italy increased from 7.5 +/- 2.2 micrograms/kg/day in 1987-90 period to 8.5 +/- 2.5 micrograms/kg/day in 1991, at a mean starting age of 34 and 26 days respectively. Therefore the dosage is modulated on the basis of serum levels of thyroid hormones and clinical signs. Some patients, in spite of a correct dosage of L-thyroxine, show a deficient suppression of TSH circulating level. In our experience this finding is sometimes due to the non-observance of the fasting condition when the drug is administered. Patients precociously identified by neonatal screening and correctly treated have a good mental and statural prognosis. In these patients, the psycho-intellectual development is better than in those diagnosed later clinically.

Child↗
PubMed1994

[Exocrine neoplasms of the pancreas and the Vater's ampulla. Anatomo-clinical and pathogenetic aspects].

Histological, immunohistochemical, and ultrastructural data accumulated in recent years have provided the basis for a more detailed classification of pancreatic cancer. This classification defines new tumour entities with distinct clinicopathologic and prognostic features. Unfortunately, morphologic and phenotypic studies of the more common ductal pancreatic cancer do not provide sufficient information to predict their clinical behaviour. The new field of investigation on genetic abnormalities in pancreatic cancer has not yet provided sufficient data to propose any genetically based classification or prognostic assessment. However, if there is some hope for prevention or cure, this will depend on efforts to clarify the molecular basis of the disease. These features could help in addressing epidemiological studies, in finding markers for diagnosis and prognosis, and might be helpful in devising completely new therapeutic approaches.

Adenocarcinoma↗
PubMed1993

Basic fibroblast growth factor in human pheochromocytoma: a biochemical and immunohistochemical study.

Biopsies of human normal adrenal medulla, adrenal pheochromocytoma, and chemodectoma were studied for the presence of basic fibroblast growth factor (bFGF). An immunoreactive M(r) 18,000 bFGF-like molecule was detected both in normal and neoplastic tissues. This molecule was identified as bFGF on the basis of its molecular weight, its affinity for heparin, and its capacity to induce plasminogen activator production in cultured endothelial GM 7373 cells. The levels of immunoreactive and biologically active bFGF appeared to be significantly higher in the extracts of adrenal pheochromocytoma and chemodectoma than in the extracts of normal adrenal medulla. bFGF immunostaining was detectable in the nuclei of chief (Type-I) cells and of endothelial cells both in normal adrenal medulla and in pheochromocytoma. Cytoplasmic bFGF positivity of endothelial cells was also observed in pheochromocytoma but not in normal tissue. The data are in keeping with the hypothesis that bFGF may exert autocrine and paracrine functions in the growth and neovascularization of human pheochromocytoma.

Adrenal Gland Neoplasms↗
PubMed1993

Expression of progesterone receptors in solid-cystic tumour of the pancreas: a clinicopathological and immunohistochemical study of ten cases.

A role for sex hormones in the pathogenesis of solid-cystic tumour (SCT) of the pancreas is suggested by its predilection for young fertile women. Controversial data have been provided for the presence of progesterone receptors (PR) and/or oestrogen receptors (ER) in SCT. We report the immunohistochemical detection of PR in ten cases of SCT. Eight were from young women. The remaining two were from a post-menopausal woman and a young boy. All cases showed PR immunoreactivity in the large majority of neoplastic cells, whereas none exhibited ER positivity. In one tumour two types of cell populations were noted, the more anaplastic invasive-type being PR negative, whereas the more typical was PR positive. PR immunoreactivity in the absence of ER may simply reflect a lower sensitivity of ER antibody failing to reveal the biochemically detectable ER, or that the PR in cells of SCT are constitutively synthesized in an oestrogen-independent way, as in T47D breast carcinoma cell line, meningioma cells and some gastric cancer cells. Our findings support the hypothesis of a possible pathogenetic role of progesterone in SCT, independent of the patient's sex and age.

Adolescent↗
PubMed1993

Dermoid cyst of the head of the pancreas area.

We report a case of dermoid cyst of the head of the pancreas area in a 26-yr-old woman radically treated with pancreatoduodenectomy and alive with no recurrence at 6-yr follow-up. The diagnostic and surgical procedures are described, and the literature is reviewed.

Adult↗
PubMed1993

Effects of choline-esterase inhibitor in experimental acute pancreatitis in rats. Preliminary results.

Choline-esterase inhibitor (C1-INH), a regulatory alpha-glycoprotein, was administered at different dosages and intervals to rats with induced acute pancreatitis. When compared to controls, treated rats showed no significant differences in the severity of histopathological lesions, such as edema and single cell necrosis. On the other hand, both mortality and extent of massive necrosis were significantly affected by C1-INH administration regardless of the dosages.

Acute Disease↗
PubMed1993

Effects of 1,25-dihydroxyvitamin D3 and growth hormone therapy on serum osteocalcin levels in children with growth hormone deficiency.

In order to investigate the influence on bone metabolism of growth hormone (GH), we evaluated the response to an acute load of 1,25(OH)2D3 (Rocaltrol) (1.5 micrograms/day for 4 days) in 16 growth hormone-deficient prepubertal children (11 boys and 5 girls, aged from 6.2 to 9.6 years) both before and after 1 month of human GH (hGH) therapy (0.1 IU/kg/day, 6 times per week). Before and after the 1,25(OH)2D3 load, serum IGF-I, osteocalcin, Ca, P, alkaline phosphatase (ALP) and urinary excretion of Ca and P were measured. The serum levels of osteocalcin rose significantly after the first 1,25(OH)2D3 load, without an increase in IGF-I values and with a slight non-significant increase in serum Ca and P. Almost superimposable increases of osteocalcin, Ca and P were observed after 1 month of hGH therapy, with a significant increase of IGF-I, but they did not rise further after the second 1,25(OH)2D3 load. On the basis of our results, 1,25(OH)2D3 seems to have a stimulatory action on osteoblastic activity even in the absence of normal levels of GH. However, there is no apparent additional stimulatory activity after administration of hGH. Osteocalcin level behaviour during our study might suggest that GH and 1,25(OH)2D3 have a common and easily saturable stimulatory pathway on osteoblastic function.

Alkaline Phosphatase↗
PubMed1993

Transbronchial biopsy in lymphangiomyomatosis of the lung. HMB45 for diagnosis.

We have investigated the presence of smooth muscle cells with immunoreactivity for melanoma-related marker HMB45 in pulmonary lymphangiomyomatosis (PLAM). Of 75 lung specimens, including a variety of lesions (obtained with both transbronchial and open lung biopsies), only PLAM (six specimens from three patients) showed the presence of HMB45-positive cells. In addition, 20 specimens of normal lung were unreactive with this monoclonal antibody. It is concluded that the smooth muscle cells of PLAM regularly exhibit a peculiar phenotype, characterized by HMB45 immunoreactivity, distinct from other smooth muscle proliferations; and the histological diagnosis of PLAM can be made when only a transbronchial biopsy is available.

Adult↗
PubMed1993

Influence of dietary taurine on vitamin D absorption.

To evaluate the influence of dietary taurine supplementation on vitamin D absorption, we studied three groups of infants: 21 (11 preterm) were fed a taurine-free formula, 21 (10 preterm) were fed a taurine-supplemented formula (50 mg/100 g of powder) and 20 (9 preterm) were fed human, not heat-treated milk. Taurine, total bile acids, glyco-(GBA) and tauro-(TBA) conjugated bile acids, 25-hydroxyvitamin D3 (25OHD3) and 1,25-dihydroxyvitamin D3 (1,25OH2D3) were determined in all infants at birth in blood cord and at one and three months of life. In preterm infants fed a taurine-free formula, we found lower plasma taurine levels than in infants of other groups at one and three months of life. In these infants, GBA predominated, with a G/T ratio of 1.1 and 1.4 at one and three months of life, whereas in all other infants TBA predominated with a G/T ratio always < 1. Also, 25OHD3 and 1,25OH2D3 levels were significantly lower in preterm infants fed a taurine-free formula than in infants fed a taurine-enriched formula or human milk. Term infants fed a taurine-free formula did not show differences in the parameters studied in comparison to infants of other groups. Low taurine dietary intake appears to compromise vitamin D absorption in preterm infants, and therefore taurine supplementation of preterm infant formulas should be encouraged.

Bile Acids and Salts↗
PubMed1993

Impaired response of free alpha-subunits after luteinizing hormone-releasing hormone and thyrotropin-releasing hormone stimulations in beta-thalassemia major.

In order to clarify whether the damage in gonadotropin secretion due to iron overload in patients with beta-thalassemia is of pituitary or hypothalamic origin, 14 euthyroid patients (8 females and 6 males, age 15-24 years) affected by beta-thalassemia major with hypogonadotropic hypogonadism were studied. Luteinizing-hormone (LH), follicle-stimulating hormone (FSH) and free alpha-subunit (FAS) were measured during LH-releasing hormone (LH-RH) stimulation test, and thyroid-stimulating hormone (TSH), prolactin (PRL) and FAS during thyrotropin-releasing hormone (TRH) stimulation test. During LH-RH stimulation, the mean basal LH, FSH and FAS levels were similar to those found in normal prepubertal children, but the peak values were lower than those found in such children. Also during TRH stimulation, the mean peak values of FAS were lower than those of normal prepubertal children, but the TSH response was normal. The lack of response of gonadotropins and FAS to LH-RH cannot exclude hypothalamic failure; however, the normal response of TSH to TRH, in spite of the poor response of FAS, indicates that the origin of hypogonadotropic hypogonadism is the pituitary damage concerning not only the gonadotroph but also the thyrotroph cells.

Adolescent↗
PubMed1993

Neoplasia of the ampulla of Vater. Ki-ras and p53 mutations.

Eleven tumors of the ampulla of Vater (5 stage IV and 2 stage II adenocarcinomas, 1 stage II papillary carcinoma, 1 neuroendocrine carcinoma, and 2 adenomas, one with foci of carcinoma) were examined for Ki-ras and p53 gene mutations by single-strand conformation polymorphism analysis and direct sequencing of polymerase chain reaction-amplified DNA fragments. Ki-ras mutations were found in one adenocarcinoma and in the adenoma with foci of carcinoma, both involving mainly the intraduodenal bile duct component of the ampulla. Seven cases showed p53 gene mutations: four advanced-stage adenocarcinomas, the papillary carcinoma, the neuroendocrine carcinoma, and the adenoma with foci of carcinoma. Nuclear accumulation of p53 protein was immunohistochemically detected in the morphologically high-grade areas of the five cancers harboring a p53 gene missense point mutation. The adenomas, the two frame shift-mutated cancers, and the adenomatous and low-grade cancer areas of mutated carcinomas were immunohistochemically negative. Our data suggest that in ampullary neoplasia 1) p53 mutations are common abnormalities associated with the transformation of adenomas and low-grade cancers into morphologically high-grade carcinomas, and 2) Ki-ras mutations are relatively less frequent and might be restricted to tumors originating from the bile duct component of the ampulla.

Aged↗
PubMed1993

Pancreatic adenocarcinomas frequently show p53 gene mutations.

Thirty-four pancreatic adenocarcinomas were studied for the presence of p53 gene mutations by the single-strand conformation polymorphism method and by direct sequencing of PCR-amplified fragments. p53 protein expression was immunohistochemically evaluated using monoclonal PAb1801 and polyclonal CM1 antibodies. Mutations were detected in 14 cases. The transitions were six G to A and two A to G; the transversions were one C to G and two A to C; the remaining three were frameshift mutations. Immunostaining results were identical with both antibodies. Nuclear immunohistochemical p53-positive cells were found in nine p53 mutated cases and in 12 cases in which no mutation was detected. In most of these latter cases only a minority of cancer cells showed immunohistochemical positivity. Twenty-nine cases, including all p53 mutated cancers, were known to contain codon 12 Ki-ras gene mutations. Also in the light of the demonstrated cooperation of ras and p53 gene alterations in the transformation of cultured cells, our data suggest that p53 mutation is one of the genetic defects that may have a role in the pathogenesis of a proportion of pancreatic cancers.

Adenocarcinoma↗
PubMed1992

Progesterone receptor immunoreactivity in pancreatic endocrine tumors. An immunocytochemical study of 156 neuroendocrine tumors of the pancreas, gastrointestinal and respiratory tracts, and skin.

BACKGROUND: The immunoreactivity for progesterone receptors (PR) of the majority of endocrine cells of the human pancreas has prompted the authors to investigate if PR expression is maintained in pancreatic endocrine tumors and is correlated with the main clinicopathologic features of these neoplasms. Furthermore, the study has been extended to other neuroendocrine cells and tumors to determine whether PR immunoreactivity is a common feature of neuroendocrine cells and tumors other than those of the pancreas. METHODS: One hundred fifty six neuroendocrine tumors of the pancreas, gastrointestinal and respiratory tracts, and skin were immunostained for PR with three different monoclonal antibodies and for estrogen receptors (ER). Additional immunostainings for general neuroendocrine markers and for pancreatic hormones were performed in selected cases. RESULTS: Nuclear immunoreactivity for PR has been documented in the neoplastic cells of 56 (58.33%) of 96 pancreatic endocrine tumors. PR immunoreactivity was not influenced by the sex and age of the patients or the occurrence of a clinical syndrome related to inappropriate hormone secretion. Tumors synthesizing pancreatic polypeptide, glucagon, and insulin expressed PR in higher percentages (80%, 75%, and 66%, respectively) than those producing other pancreatic hormones or those that were not functioning. Irrespective of the functionally different tumor types, PR immunoreactivity showed a significant correlation (P = 0.0003) with the absence of metastases and the lack of tumor invasion of neighboring organs or of large vessels. As opposed to normal and neoplastic islet cells, the neuroendocrine cells and tumors of the gastrointestinal tract, respiratory tract, and skin did not show any PR immunoreactivity, with the single exception of a typical carcinoid tumor of the lung. ER were not identified in any pancreatic or extrapancreatic neuroendocrine cells or tumors. CONCLUSIONS: Nuclear PR are immunocytochemically detectable in most pancreatic endocrine tumors and are correlated significantly to the absence of pathologic evidence for malignancy. Conversely, PR expression has not been found in normal and neoplastic endocrine cells and tumors investigated.

Adenoma, Islet Cell↗