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Biomedical subjects

M Volante

Publications and source records attributed to M Volante.

At least 37 records · Page 2Linked to original sources
PubMed2001

Extensive DNA fragmentation in oxyphilic cell lesions of the thyroid.

The in situ end-labeling (ISEL) method demonstrates DNA fragmentation, commonly regarded as a marker of apoptosis. We investigated by the ISEL procedure a series of 52 thyroid lesions, including 24 lesions of mitochondrion-rich oxyphilic cells, both benign and malignant, and 28 non-oxyphilic control tumors. A high percentage of nuclear ISEL staining (approximating to 100% in most cases) was observed in the vast majority of oxyphilic cells from both adenomas and carcinomas, in the absence of morphological apoptotic changes and with no immunocytochemical evidence of caspase activation. This pattern of DNA fragmentation was not observed in non-oxyphilic lesions and was confirmed in total extracted DNA. Moreover, a peculiar cytoplasmic staining was also observed in oxyphilic cells from both benign and malignant lesions, probably related to abnormal fragmentation of mitochondrial DNA. Similar staining patterns were detected in oxyphilic cell tumors of other organs (parathyroids, salivary glands, and kidneys). These findings are consistent with an extensive DNA fragmentation peculiar to oxyphilic cells, which is not directly related to apoptosis and whose origin and biological significance are presently unknown.

Caspases↗
PubMed2001

Ghrelin-producing endocrine tumors of the stomach and intestine.

Ghrelin is a novel gastrointestinal hormone produced by about 20% of the rat and human gastric neuroendocrine cell population, which possesses strong GH-releasing activity, but also plays other central and peripheral roles, including influence on food intake, gastric motility, and acid secretion. The aim of the present study was to determine whether gastrointestinal endocrine hyperplastic and neoplastic lesions produce ghrelin, at both protein (immunohistochemistry) and mRNA (in situ hybridization and/or RT-PCR) levels, and express the GH secretagogue receptor mRNA by RT-PCR. Sixteen gastric and 20 intestinal carcinoids as well as normal gastrointestinal mucosa and atrophic gastritis-associated neuroendocrine cell hyperplasia were studied. The majority (12 of 16, 75%) of gastric carcinoids and only 5 of 18 (27%) of intestinal endocrine tumors were immunoreactive for ghrelin. In situ hybridization confirmed the immunohistochemical data, but also showed ghrelin mRNA in 1 gastric and 8 intestinal additional tumors. RT-PCR showed ghrelin mRNA in 14 of 14 cases, indicating a low level of ghrelin gene expression in all gastrointestinal endocrine tumors tested. Gastric neuroendocrine hyperplastic cells were also strongly positive for ghrelin. GH secretagogue receptor mRNA was absent in 3 gastric, but present in 7 of 11 intestinal carcinoids studied by RT-PCR. These findings demonstrate that most gastric carcinoids (and related neuroendocrine cell hyperplasias) and some intestinal carcinoids produce ghrelin. These hyperplastic/neoplastic conditions could represent the clinical model to clarify the existence and impact of ghrelin hypersecretion on endocrine and nonendocrine functions.

Adult↗
PubMed2001

Classic and recent special stains used in differential diagnosis of endocrine tumors.

During the twentieth century, stains for endocrine cells and tumors were developed from empiric cytologic procedures aimed at modern cytochemical methods. Before the 1970s, endocrine stains were mainly based on silver reaction, although other reactions were also proposed; however, the chemical basis of most of these reactions is still unclear. The development of fluorescence procedures for detecting biogenic amines at the cellular level provided information about endocrine cell function of normal cells and related tumors. However, the application of immunocytochemical reactions brought greater and more definitive insights. Several immunocytochemical markers are now available. Some are specific for a definite cell type, while others detect endocrine differentiation in general. Some of these "pan-endocrine" markers are highly specific, and others are highly sensitive but less specific. They all play a definite role in diagnostic pathology. The use of molecular procedures to detect specific mRNA or genetic mutations of diagnostic interest in endocrine pathology should complement immunophenotyping, especially in some problematic fields, such as that of "poorly differentiated" tumors.

Antigens, Neoplasm↗
PubMed2001

[Visceral pleural lipoma: description of a autopsy case].

Pleural lipomas are rare tumours, usually arising from the parietal pleura, which are often asymptomatic and observed incidentally. We describe the clinicopathological features of a case of lipoma arising from the visceral pleura, accidentally discovered in a 69-year-old ma, at autopsy. A review of the literature concerning pleural lipomas is also presented.

Adipocytes↗
PubMed2000

Thyroglobulin mRNA expression helps to distinguish anaplastic carcinoma from angiosarcoma of the thyroid.

The existence of angiosarcoma (AS) of the thyroid has been a matter of debate for many years, because some authors believe that most if not all ASs are in fact "angiomatoid" anaplastic carcinomas (ACs). Immunohistochemistry alone was not successful in solving the problem, since cytokeratin expression is a known occurrence in AS. Therefore, we wanted to compare nine cases of AS with ten cases of AC, assessing whether thyroglobulin (TG) mRNA was still transcribed in undifferentiated tumors and could be helpful to distinguish AC from AS. The cases were analyzed for TG mRNA expression by means of radioactive in situ hybridization. The silver grains were counted using an automated device, and their amount was compared with that of stroma, background, and peritumoral thyroid. A weak signal was present in all AC but not in AS (mean counts 35.7 and 9.6 arbitrary units, respectively: P<0.01). In two cases of AC, residual areas of poorly differentiated insular carcinoma had a strong signal (similar to that of peritumoral thyroid). These findings further confirm that AC and AS of the thyroid are unrelated malignant tumors.

Adult↗
PubMed2000

RET/PTC activation in hyalinizing trabecular tumors of the thyroid.

Hyalinizing trabecular tumor (HTT) of the thyroid is a neoplasm of follicular derivation with a histogenesis that is still the subject of debate. Morphologic affinities between HTT and papillary carcinoma, including nuclear pseudoinclusions and grooves, suggest that these tumors may be of similar origin. The authors investigated the relationship between these two types of tumors by assessing HTT for the presence of rearrangements of the proto-oncogene rearranged during transfection (RET) that, in thyroid tumors, are specific for papillary carcinoma. A series of 14 HTTs, including two cases associated with classic papillary carcinoma, was studied by means of immunohistochemistry and reverse transcription-polymerase chain reaction. Seven follicular adenomas with focal hyalinized trabecular areas served as control cases. Three of the 14 HTT cases under consideration displayed rearrangements of RET generating the RET/papillary thyroid carcinoma type 1 (PTC1) oncogene. In another case, RET expression was detected focally by immunohistochemistry alone. Finally, in one mixed HTT-papillary carcinoma sample, RET/PTC1 expression was detected, but only in the papillary component. None of the control follicular adenomas contained rearrangements of RET/PTC. These findings demonstrate that a comparable percentage (28.6%) of HTTs and papillary carcinomas exhibit the same RET proto-oncogene alterations. Thus, HTT may represent the "hyalinizing trabecular" variant of papillary carcinoma rather than a separate entity.

Adenoma↗
PubMed2000

Thyroid carcinomas with mixed follicular and C-cell differentiation patterns.

Divergent endocrine-neuroendocrine differentiation in thyroid carcinoma occurs in mixed medullary-follicular carcinomas (MMFC). Less than 40 cases of MMFC have been reported having highly heterogeneous patterns of growth. Classical medullary carcinoma areas may be intermingled with follicles or papillae or even oxyphilic and solid areas. Calcitonin and thyroglobulin are expressed in different cell populations. Presence of the latter suggests a potential usefulness of radioiodine treatment. The clinical behavior of MMFC does not differ from that of ordinary medullary carcinoma. The histogenesis of MMFC is controversial. The genetic analysis of the 2 neoplastic components showed that they are not derived from a common precursor, but rather display remarkable differences in the genetic profile (RET mutations and allelic losses). In addition, in some cases the follicular component was found to be oligo/polyclonal and therefore possibly hyperplastic rather than neoplastic. The follicular cells may have grown into the medullary carcinoma, after acquiring some molecular defect, being "hostage" of the true neoplastic (medullary) component.

Adenocarcinoma, Follicular↗
PubMed1999

Mixed medullary-follicular thyroid carcinoma. Molecular evidence for a dual origin of tumor components.

Mixed medullary-follicular carcinomas (MMFCs) are tumors of the thyroid that display morphological and immunohistochemical features of both medullary and follicular neoplasms. The histogenetic origin and possible molecular mechanisms leading to MMFCs are still unclear. To address these questions, we have isolated the two histological components of 12 MMFCs by (laser-based) microdissection, analyzed them for mutations in the RET proto-oncogene and allelic losses of nine loci on six chromosomes, and studied the clonal composition of MMFCs in female patients. Our results provide strong evidence that the follicular and medullary components in MMFCs are not derived from a single progenitor cell, because the seven tumors amenable for analysis consistently exhibited a different pattern of mutations, allelic losses, and clonal composition. We also demonstrate that follicular structures in MMFCs are often oligo/polyclonal and more frequently exhibit hyperplastic than neoplastic histological features, indicating that at least a subset of MMFCs are composed of a medullary thyroid carcinoma containing hyperplastic follicles.

Adult↗
PubMed1999

Interleukin-6 levels in co-culture of human in vitro fertilization embryos with Vero cells are not predictive of future successful development.

PROBLEM: In an attempt to predict successful embryo transfer and implantation, we measured interleukin (IL)-6 levels in culture supernatants of co-cultured preimplantation human embryos. We tested whether all in vitro fertilized human embryos in co-cultures do secrete IL-6, and whether there was any difference in such production between embryos that successfully reached the blastocyst stage and blocked embryos. We also addressed the question of IL-6 secretion by co-culture support cells, namely Vero cells themselves. METHOD OF STUDY: Each fertilized oocyte was cultured individually and transferred in culture wells supplemented with a feeder layer of Vero cells at day 2. In vitro IL-6 production was measured by bioassay of the culture media. RESULTS: Because Vero cells themselves secrete IL-6, it became impossible, in co-culture, to quantify production of IL-6 by the sole embryos. On the other hand, the co-culture technique has shown us that embryos are likely to consume IL-6. There was no difference between blastocysts and blocked embryos. CONCLUSIONS: IL-6 levels in human embryo co-cultures do not correlate with future successful embryo transfer.

Adult↗
PubMed1998

Inter-laboratory validation of solid-phase microextraction for the determination of triazine herbicides and their degradation products at ng/l level in water samples.

The accuracy and precision of solid-phase microextraction (SPME) were validated in an inter-laboratory study including ten laboratories for the analysis of triazine herbicides and their metabolites at ng/l level in aqueous samples. The SPME conditions were optimised in order to obtain maximum sensitivity. Especially, salt addition and choice of the SPME fibre coated with Carbowax-divinylbenzene increased the sensitivity. The average detection limits were in the range from 4 to 24 ng/l for the triazine herbicides, and 20 and 40 ng/l for desisopropylatrazine and desethylatrazine, respectively. The average r2 values of the calibration curves were above 0.99 for all of the analytes. The statistical data treatment was performed in accordance with the International Standardisation Organisation (ISO) standard 5725. Relative repeatability standard deviations between 6 and 14% and relative reproducibility standard deviations between 10 and 17% were found. The determined concentrations of the reference sample compared well to the "true" values, thus proving the good accuracy of the method. It is concluded that SPME is a reliable technique for the quantitative analysis of water samples containing triazine herbicides in concentrations around the European limit of 100 ng/l for individual pesticides in drinking water.

Calibration↗
PubMed1998

Postmenopausal virilization in a woman with gonadotropin dependent ovarian hyperthecosis.

We report a case of a 66-yr-old woman with progressive hair balding, hirsutism and virilization. Gonadotropins and estradiol levels were in the postmenopausal range; total testosterone (TT), free testosterone (FT) and 17-hydroxyprogesterone (17-OHP) were elevated with dehydroepiandrosterone sulphate, androstendione and cortisol serum levels in the normal range, as 24-hr free urinary cortisol. TT, FT and 17-OHP were normalized, and FSH and LH fell to premenopausal levels on 18th day after a single i.m. injection of the GnRH analogue (GnRHa), triptorelin. Then, a diagnosis of hyperandrogenism of ovarian origin was made and bilateral ovariectomy was performed. Histological study of gonadal tissue revealed diffuse stromal hyperplasia of both ovaries with occasional nests of luteinized cells. With immunoperoxidase techniques these cells stained positively for testosterone and progesterone. One month after surgery, androgen levels were normalized together with regression of most of the clinical signs of virilization. In conclusion, our patient showed a severe virilization developed after menopause; hormonal investigations suggested a gonadotropin dependent ovarian hyperandrogenism, confirmed by histological examination; the presence of luteinized cells in the ovarian stroma was responsible for hyperandrogenism, as confirmed by the immunoperoxidase technique.

17-alpha-Hydroxyprogesterone↗
PubMed1998

Female and male human embryo growth rates are similar before the eight-cell stage.

OBJECTIVE: Our purpose was to assess the possible relationship between human embryo growth rates and sexual differentiation. STUDY DESIGN: We analyzed 142 conceptional in vitro fertilization and embryo transfer cycles undertaken in 137 women (151 embryos transferred) in which each embryo transferred led to a gestational sac. Embryos were sorted into three groups according to the number of blastomeres assessed just before embryo transfers < or = 3, 4, and > or = 5 blastomeres. RESULTS: Percentages of girls and boys remained roughly unaltered irrespective of the number of blastomeres observed just before embryo transfer: < or = 3 blastomeres, 45% and 55%; 4 blastomeres, 44% and 56%; and > or = 5 blastomeres, 45% and 55%, respectively (statistical power 90% at the 5% significance level). CONCLUSIONS: This indicates that embryo growth rates before the eight-cell stage are not related to the sex of the live-born infant, thereby dissuading the use of embryo growth rates in the appraisal of sex likelihood in regular in vitro fertilization-embryo transfer.

Blastomeres↗
PubMed1998

Some applications of solid phase micro extraction (SPME) in the analysis of pesticide residues in food.

The Solid Phase Micro-Extraction (SPME) technique was applied to analyze chlorpropham in potatoes and amitraz in honey. The homogenized sample, suspended in water and stirred, was extracted with a 100 microns thick polidimetylsiloxane fiber and desorbed into the injection port of a gas chromatograph/mass-spectrometer (quadrupole) operating in single ion monitoring. Sensitivities down to 0.01 mg/Kg and linear responses in the range of 0.01-0.1 mg/Kg were obtained. The results of SPME pesticide residue analysis in potatoes corresponded to those obtained with a traditional multiresidue method.

Chlorpropham↗
PubMed1997

Retrieved endogenous biotin: a novel marker and a potential pitfall in diagnostic immunohistochemistry.

AIM: Antigen retrieval (AR) procedures are based on the effect of heating (by either microwave or pressure cooking treatments) on routinely fixed and paraffin embedded tissues. We observed that AR procedures restore the reactivity of endogenous biotin (EB) and report on the distribution of EB following AR in a series of routinely fixed and embedded tissues. METHODS AND RESULTS: Following pressure cooking or microwave treatments, a simple streptavidin-peroxidase staining revealed retrieved endogenous biotin (REB) in normal tissues (such as liver, kidney and adrenal cortex), in oxyphylic cells and in some tumours, especially in carcinomas of the kidney and of the adrenal cortex. In formalin-fixed (but not in alcohol-fixed) tissue sections, the heating procedures caused an intense and finely granular cytoplasmic reaction, following a routine streptavidin-conjugated peroxidase treatment. The staining was prevented by blocking of EB by a sequential avidin-biotin treatment. CONCLUSIONS: Retrieval of EB reactivity can cause pitfalls in diagnostic immunohistochemistry but, alternatively, it might also constitute a useful and novel diagnostic marker.

Antigens↗
PubMed1996

[Acute suppurative thyroiditis. Report of a case and review of the literature].

The authors present a case of acute suppurative thyroiditis complicated by acute dyspnoea with asphyxia in a patient of geriatric age. In this patient there were present possible infectious focuses like multiple dental abscesses and contamination of the urinary tract. Histological examination highlighted a focus of papillifer carcinoma in the context of the gland. We have a review of the literature on this observation and description. Acute suppurative thyroiditis is currently a pathology of rare observation. This rarity is due, apart from the availability of antibiotic therapy, to an intrinsic resistance of the thyroid gland to contamination. In most cases we are talking of bacterial infections, but in immunodepressed subjects fungal etiology is noteworthy. The infection could arise from primitive focuses present in any bodily district with propagation to the thyroid across different ways. Expressive is the anamnestic observation of preexisting thyroid dysfunction. After an attentive evaluation of the clinical findings, usually characteristic, it is important to complete the diagnostic course with some instrumental investigations. In particular cervical sonography, possibly associated with agobiopsy is fundamental. Initially therapy is medical (basically antibiotic). The surgical resolution foresees the drainage of the purulent abscess or the thyroidectomy if it is associated with a struma.

Acute Disease↗
PubMed1995

Chromosome 18 analysis by fluorescence in situ hybridization (FISH) in human blastomeres of abnormal embryos after in vitro fertilization (IVF) attempt.

We performed fluorescence in situ hybridization (FISH) with a chromosome 18-specific probe on human abnormal cleaved embryos, fertilized either by two spermatozoa and exhibiting three pronuclei (3 PN) or normally fertilized and exhibiting two pronuclei (2 PN) with subsequent severe fragmentation and/or blocking. The aim of the study was to evaluate the incidence of chromosome 18 anomalies among these embryos in order to evaluate the FISH efficiency on such material and to obtain more precise and complete data than those obtained with classical cytogenetic analysis. For the 3 PN cleaved embryos, FISH confirmed the frequent regulation towards diploidy (25 per cent) and the high frequency of mosaics (53 per cent). For the 2 PN blocked or damaged embryos, FISH permitted chromosome evaluation, which was otherwise impossible with classical cytogenetic techniques: we also found a high mosaic frequency (45 per cent) with these embryos. If this frequency were the same for normally developing embryos, it would be a major obstacle to the reliability of either chromosomal or genetic preimplantation diagnosis.

Blastomeres↗