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Biomedical subjects

G Micoli

Publications and source records attributed to G Micoli.

At least 19 recordsLinked to original sources
PubMed2001

Determination of 5-fluorouracil in environmental samples by solid-phase extraction and high-performance liquid chromatography with ultraviolet detection.

5-Fluorouracil (5-FU) is one of the most widely used antineoplastic drugs. It can be therefore considered to be a model compound for the identification of exposure routes during preparation and administration of cytostatic agents, especially for nucleoside analogue drugs. In this study, an HPLC-UV method was validated for determination of 5-FU in wipe samples by direct analysis of the aqueous solutions and in air samples by using solid-phase extraction (SPE). When samples were pre-treated on styrene-divinylbenzene resin SPE columns, a 20-fold preconcentration of the analyte was achieved. As regards air samples, correlation coefficients were always higher than 0.998 and the limit of detection was assessed at 15 ng on filter. In order to verify the reliability of these procedures, 5-chlorouracil was used as internal standard. The procedure presented here has been applied to the environmental monitoring of occupational exposed subjects. The amount of 5-FU ranged from 0.043 to 0.23 microg/m3 in air samples and from 0.2 to 470.1 microg/dm2 in wipe samples. 5-FU was also detected on the internal side of the gloves (0.07 to 3.77 microg/pair of gloves).

Chromatography, High Pressure Liquid↗
PubMed2000

Determination of methotrexate in environmental samples by solid phase extraction and high performance liquid chromatography: ultraviolet or tandem mass spectrometry detection?

In order to assess exposure levels of hospital personnel involved in the preparation and administration of antineoplastic drugs, environmental monitoring should be carried out. Wipe samples, pads, gloves and air samples should be collected at the end of each work shift, properly treated and then analysed using instrumental techniques which are sufficiently sensitive and specific to detect even trace amounts of drug. In this study, a method using high performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS), incorporating solid phase extraction (SPE), was validated for determination of methotrexate (MTX) in wipe and air samples. Each step of the method was first developed and optimised using ultraviolet detection (UV), and afterwards tandem mass spectrometry was used to obtain a lower limit of quantitation when the expected drug level was less than the analytical UV detection limit. SPE enabled a 20-fold preconcentration of the analyte when using HPLC/UV and a further 30-fold preconcentration was obtained when analysing samples by HPLC/MS/MS. For example, the limit of quantitation (LLQ) was lowered from 3000 ng on wipe (direct injection onto an HPLC/UV system) to 5 ng on wipe (SPE plus HPLC/MS/MS). 7-hydroxymethotrexate was used as internal standard to assess precision and accuracy.

Antimetabolites, Antineoplastic↗
PubMed2000

Rapid and sensitive determination of paclitaxel (Taxol(R)) in environmental samples by high-performance liquid chromatography tandem mass spectrometry

A new, rapid and sensitive method for the quantitative determination of paclitaxel (Taxol(R)) in environmental samples is developed and validated. This highly sensitive and specific method was successfully applied to an environmental monitoring study for identifying occupational exposure situations to anticancer drugs. After addition of an internal standard, 2'-methylpaclitaxel, aqueous extraction of wipe samples or air filters followed by a single-step liquid-liquid extraction with ethyl acetate was performed. Extraction efficiency averaged 90%. The method is based on analysis by liquid chromatography with tandem mass spectrometry in selected reaction monitoring mode of environmental samples from the preparation and administration of cytostatic agents. The assay is linear (r = 0.998) in the range 2-64 ng on filters (air samples), and 20-320 ng on wipe samples. The accuracy of the assay is always </=20% for both matrices, and the intra- and interday assay variability of paclitaxel ranged from 7 to 19% and 10 to 14%, respectively. The lower limit of quantification is assessed at 2 ng on filter and 10 ng on wipe samples. Copyright 2000 John Wiley & Sons, Ltd.

Journal Article↗
PubMed1999

Seasonal effect on airborne pyrene, urinary 1-hydroxypyrene, and benzo(a)pyrene diol epoxide-hemoglobin adducts in the general population.

Exposure to airborne polycyclic aromatic hydrocarbons (PAHs) in 65 employees (40 sampled both in summer and winter, 15 sampled in summer only, and 10 sampled in winter only) with no occupational exposure to PAHs was assessed by measuring: personal exposure to pyrene, urinary excretion of 1-hydroxypyrene (1-OHP), and benzo(a)pyrene diol epoxide adducts to hemoglobin (BPDE-Hb). Overall, office employees were exposed to significantly higher levels of pyrene in winter (4.54 +/- 2.35 ng/m3, mean +/- SD) than in summer (1.67 +/- 1.92 ng/m3, mean +/- SD; P < 0.001), but no such seasonal variability was observed in 1-OHP excretion. Tobacco smoking was the major determinant of 1-OHP excretion. BPDE-Hb adducts were measured by gas chromatography-mass spectrometry as benzo(a)pyrene tetrols (BPT) released from adducted hemoglobin. In the 65 employees analyzed, mean BPT levels +/- SD were higher in winter (0.14 +/- 0.38 fmol/mg Hb) than summer (0.031 +/- 0.022 fmol/mg Hb). This difference was not statistically significant, probably because of the small proportion of subjects with detectable adducts (11% in summer and 16% in winter). BPDE-Hb adducts were not significantly associated with sex, age, diet, smoking habits, or with pyrene levels and 1-OHP excretion. This is the first report providing reference BPDE-Hb adduct values for the general population not occupationally exposed to environmental PAHs and shows a tendency to seasonal variability, with higher BPT levels in winter when environmental PAHs are also high.

Adolescent↗
PubMed1997

Urinary 1-hydroxypyrene as a marker of exposure to pyrene: an epidemiological survey on a general population group.

Urinary levels of 1-hydroxypyrene in a general adult population group are studied. Experimental data are not normally distributed; statistical analysis required a base 10 logarithmic transformation of data. The concentrations of urinary 1-hydroxypyrene measured were expressed as microgram g-1 urinary creatinine and are comparable with those reported by other authors, both for smoker and non-smoker subgroups. Multiple regression analysis shows that, for smokers, the number of cigarettes smoked per day and the body mass index (BMI) significantly influence the levels of urinary 1-hydroxypyrene expressed as microgram g-1 urinary creatinine, whereas no personal or behavioural variable (age, sex, alcohol consumption, dietary intake of pyrene, BMI) modified the 1-hydroxypyrene levels for non-smokers.

Adult↗
PubMed1997

Determination of environmental reference concentration of six PAHs in urban areas (Pavia, Italy).

We propose a sampling strategy, using individual dosimetry to measure the daily inhaled quantity of PAHs in urban air. The method was applied to monitor 56 subjects living in an Italian town (Pavia; 80 000 inhabitants) and the Environmental Reference Concentration (E.R.C.) of six PAHs (classified as 'possible' carcinogenic agents for humans) was determined. The individual environmental samplings took place in two different seasons (winter and summer), for persons living in four different urban areas with different traffic density. Subjects were selected using a specific questionnaire designed to collect information on indoor and indoor+outdoor exposure times. The mean +/- S.D. value of Benzo[a]pyrene [BaP] was 0.37 +/- 0.15 ng m-3 in winter and 0.12 +/- 0.07 ng m-3 in summer. Assuming 18 m3 as the daily inhaled quantity the estimate of the BaP inhaled quantity was 6.66 ng/day in winter and 2.16 ng/day in summer.

Air Pollutants↗
PubMed1994

[Primary embryonal rhabdomyosarcoma of the breast. Description of a case].

Authors report a case of embryonal rhabdomyosarcoma of the breast occurring in a 16-year-old girl. To date, 26 cases have been described in the literature of which only 4 in girls younger than 16 years. Histological features, immunohistochemical findings and differential diagnosis are discussed.

Adolescent↗
PubMed1993

The basement membranes in sarcomatoid carcinomas. An immunohistochemical study.

AIMS: Eight sarcomatoid carcinomas from various anatomical locations were investigated by immunohistochemical staining to laminin, type IV collagen and heparan sulfate proteoglycan, to study the characteristics of basement membranes at the interface between carcinomatous and sarcomatous tissues. METHODS: Paraffin wax embedded tissue sections from representative tumor samples have been stained with specific antibodies, using the peroxidase-antiperoxidase technique. RESULTS: In all cases several interruptions or discontinuities of the basement membrane staining pattern were seen. In 4 cases, larger defects or complete loss of staining was also noted. At these places, the boundaries between carcinomatous and sarcomatous tissue were often blurred. CONCLUSIONS: Disruption and loss of basement membranes at interface between carcinomatous and sarcomatous tissues is a frequent finding in sarcomatoid carcinomas. These changes could be consistent with an epithelial origin of the sarcomatous component in these tumors by means of an epithelial-mesenchymal conversion mechanism.

Aged↗
PubMed1993

The extracellular matrix in sarcomatoid carcinomas of the breast.

The distribution of the main extracellular matrix components has been investigated immunohistochemically in four cases of breast sarcomatoid carcinomas. The histogenesis of these tumours is still unclear, but most evidence suggests that the sarcomatous component originates from mesenchymal conversion of carcinomatous cells. We found that carcinomatous portions of the tumours were associated with linear basement membrane-like deposition of laminin, type IV collagen and heparan sulphate proteoglycan that partially circumscribed the epithelial nests. The sarcomatous components produced an extracellular matrix immunoreactive to fibronectin, type I, III and VI collagens and tenascin. However, in two cases, in some sarcomatous areas, focal pericellular staining for antibodies to laminin and type IV collagen was seen. These results indicate that modifications observed in the double tissue component of these tumours involve not only the cell shape and the cytoskeleton, but also the components of the extracellular matrix. The significance of these findings and their relevance in the understanding of the phenotypic pattern changes of these biphasic tumours are discussed.

Aged↗
PubMed1993

Ductal adenoma of the breast. An immunohistochemical study of five cases.

The immunohistochemical features of 5 ductal adenomas of the breast were investigated. The tumours were composed by tubular glands lined by cells with both luminal and basal/myoepithelial immunophenotypes. Tubules were encircled by an intact basement membrane as demonstrated by staining for laminin and type IV collagen. Areas of dense fibrosis, a usual finding in these lesions, stained for fibronectin, type III collagen and contained vimentin and actin positive spindle cells, consistent with myofibroblasts. These observations confirm a double epithelial and myoepithelial differentiation in these lesions and seem to support the suggestion that ductal adenomas result from sclerosis of ductal papillomas.

Adult↗
PubMed1993

Carcinosarcoma of the oesophagus with rhabdomyoblastic differentiation.

We report a case of oesophageal carcinosarcoma with prominent rhabdomyoblastic differentiation. Immunohistochemically, the rhabdomyblasts were mainly reactive to vimentin, cytokeratin, desmin, muscle-specific actin, myosin, and myoglobin, and were surrounded by laminin and type IV collagen-positive basement membranes. The tumour had dual differentiation, carcinomatous and sarcomatous, but also showed evident features of transition between the two components; suggesting a common origin. An epithelial-mesenchymal conversion could be the pathogenetic mechanism involved in the histogenesis of this lesion. The word carcinosarcoma, from a descriptive point of view, seems the most suitable to describe a tumour composed of both carcinomatous and true sarcomatous elements.

Aged↗
PubMed1993

Xanthogranulomatous gastritis: association with xanthogranulomatous cholecystitis.

A case of xanthogranulomatous inflammation of the gastric wall is reported. The lesion was associated with adherent xanthogranulomatous cholecystitis and simulated, clinically, a malignant neoplasm. Histologically, foamy histiocytes, multi-nucleated giant cells, other inflammatory cells, fibrous reaction with spindle cells and cholesterol clefts were found.

Aged↗
PubMed1993

[Late pancreatic metastasis of renal carcinoma. Description of 2 cases and review of the literature].

Authors report two cases of pancreatic metastasis from renal clear cell carcinoma, discovered in a 62 years-old-man and in a 73 years-old woman, respectively 17 and 11 years after undergoing curative nephrectomy for primary tumor. Immunological forces and slow doubling times of tumor may explain this type of late recurrence, whereas, the endocrine status is lacking in importance. The risk of a recurrence of tumour ten years or later after nephrectomy suggests a lifelong follow-up of patients with an history of renal cell carcinoma.

Aged↗
PubMed1992

Smooth muscle contraction bands in intestinal infarction.

We studied microscopic sections of 24 cases of intestinal infarction looking for contraction bands (CB) in the muscularis propria of the bowel wall. Controls were 11 surgical and 11 autopsy cases from patients who did not suffer any form of ischaemic disease. The difference of CB frequency was significant (P less than 0.001) in infarction versus the surgical control group. Moreover, within the study group the CB frequency was also related to the severity of the ischaemic lesion (P less than 0.01). With immunostaining, CB were not reactive with antibodies against vimentin, desmin, actin or myosin. We propose that CB genesis in intestinal smooth muscle is related to hypoxia, possibly through altered homeostasis of calcium and catecholamine metabolism.

Aged↗
PubMed1991

Liposarcoma in a child: a case report.

Liposarcoma is a soft tissue tumor usually observed in adults. Although occasional cases have been reported in childhood, it is virtually unknown in infants and small children. Our experience documents a case of liposarcoma in a 6-year-old girl, an extremely rare occurrence in this age-group. The patient underwent wide local excision followed by chemotherapy. Histologically, the tumor was a myxoid type. Differential diagnosis and problems concerning prognosis and therapy of this tumor in children are discussed.

Child↗
PubMed1985

Determination of total and hexavalent chromium in bile after intravenous administration of potassium dichromate in rats.

Total and hexavalent chromium were measured in bile samples obtained from cannulated bile ducts of male rats iv administered with potassium dichromate at various doses corresponding to 0.1, 0.5, and 1 mg of chromium. The evaluation of the hexavalent form was performed by separation with a liquid anion exchanger and electrothermal atomization-atomic absorption spectrophotometric determination. Within 2 hr 1.35-2.23% of the chromium injected was recovered in bile as total chromium, the hexavalent form accounting for less than 1% of the total chromium collected, which seems almost entirely excreted as trivalent chromium. Since Cr(VI) administered iv was quickly reduced to Cr(III) in blood, the possibility exists for chromium in trivalent form to penetrate into the liver cells and to be excreted in the bile, possibly by binding to a carrier such as the low-molecular-weight substance described by Yamamoto et al. (A. Yamamoto, O. Wada, and T. Ono, Toxicol. Appl. Pharmacol. 59, 515, 1981).

Animals↗
PubMed1984

Biological monitoring of occupational exposure to different chromium compounds at various valency states.

Chromium concentrations in the air were measured in seven different workroom environments, where exposure to water soluble hexavalent or trivalent compounds was expected. Urinary excretion of chromium was measured before and after the same arbitrarily chosen working day. End-of-shift urinary chromium and its increase above pre-exposure levels were closely related to the concentration of water soluble chromium (VI) in the air. The values corresponding to 50 micrograms m-3 in the air, which is the current threshold limit value in most countries, were 29.8 and 12.2 micrograms g-1 of creatinine, respectively. Urinary chromium in workers exposed to water insoluble chromates or to water soluble chromic (III) sulphate was definitely higher than that observed in subjects not occupationally exposed to chromium compounds, but it cannot be recommended as short-term exposure test for evaluation of the job-related hazard.

Absorption↗