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Biomedical subjects

A Lucchese

Publications and source records attributed to A Lucchese.

At least 19 recordsLinked to original sources
PubMed2006

Complex odontoma: confocal laser scanning microscopy analysis of a case.

Confocal laser scanning microscopy (CLSM) represents a recent acquisition in the study of biological samples stained for fluorescence observation. Particularly, this technique allows a bidimensional investigation of tissues and cells with the possibility to elaborate a three-dimensional model. The aim of this study is the use of this technique, as a complementary and not substitutive application of the histological examination, for the morphological and histopathological analysis in a case of mixed complex-composed odontoma. The analyzed specimen has been surgically removed in the superior frontal region in a 12 year-old boy and submitted to conventional histopathological analysis. The specimen, hematoxylin-eosin stained, has been subsequently submitted to confocal laser scanning microscopic analysis in autofluorescence by using a Nikons C1 system. This analysis has underlined not visible aspects in traditional optical microscopy, such as the mineralization of hard tissues and the morpho-structural organization of the cellular component. The presence of enamel and dentin may be observed in the different phases of odontogenesis with clear fluorescence gradients determined by the different mineralization degrees. Thus, the odontogenetic components appear strongly autofluorescent in the classical follicular configuration. Three-dimensional reconstruction is made possible by the acquisition of serial bidimensional images that are subsequently analysed by using a specific software device. This study shows the confocal laser scanning microscopy versatility in the analysis of odontogenic neoplasms with production of mineralized tissues.

Ameloblasts↗
PubMed2003

Prognosis of third molar eruption: a comparison of three predictive methods.

OBJECTIVES: Prediction of third molar eruption carries significant prognostic importance. There have been various reports of methods to predict the probability of impaction of these teeth. We studied the level of agreement between these three prediction methods. MATERIALS AND METHODS: a total of 61 patients, mean age 16.4+/-0.98, of Italian origin with initially retained 121 lower third molars were selected for this study. Panoramic radiographs were taken on each subject. For each third molar, the prognosis of eruption was assessed by three different cephalometric techniques: Olive, Ganss, Venta. The Kappa coefficient was used to compare results between the 3 methods (pairwise agreement) for each individual molar, the McNemar test to assess pairwise imbalance. RESULTS: a weak agreement was found between Ganss and Olive, fair between Venta and Ganss and between Olive and Venta. Additionally, the statistical analyses revealed a significant imbalance within the pairwise comparisons. CONCLUSIONS: the three methods were not found to be reliable or accurate; perhaps, the method of Castella et al. holds better promise.

Adolescent↗
PubMed2001

Individuation of monoclonal anti-HPV16 E7 antibody linear peptide epitope by computational biology.

We applied computational biology to identify the linear amino acid sequence recognized by a mouse monoclonal antibody raised against the full length HPV16 E7 oncoprotein. Computer-assisted search for the epitopic peptide used two parameters: the capability of E7 peptides to bind to MHC class II molecules, and the similarity level of the oncoprotein sequence to the mouse proteome. We report that anti-E7 mAb recognized the peptide having both high binding potential to MHC II molecules and low level of molecular mimicry to mouse proteome. Peptide ability to bind to MHC II molecules appears a necessary but not sufficient condition to determine peptide immunodominance, by needing to be supported by a low degree of peptide similarity to the host's proteome.

Amino Acid Sequence↗
PubMed2000

Metastatic breast cancer in pregnancy: first case of chemotherapy with docetaxel.

The focus of this paper is a case study of a woman in the first trimester of pregnancy who presented with metastatic breast cancer. The bony spread of the metastases was rapid and it was necessary to treat the patient as soon as possible after the period of organogenesis (days 18-60 of human gestation). This stage is the phase of greatest sensitivity of teratogens and the malformations are observed most often. Yet, the choice of third-line chemotherapy was difficult because of anthracycline-resistant metastatic breast cancer. The world literature reported cytotoxic combinated regimens as the standard of care for the management of the metastases. The development of new antitumoral strategies with less toxicity and their encouraging results led us to the approval of docetaxel for the treatment of the patient even though it had never been tested in pregnancy. Docetaxel is a potent inhibitor of microtubule depolymerization and has a unique ability to alter certain classes of microtubules. The monochemotherapy was administered once every 3 weeks for a total of three cycles until 30 weeks of gestation. During the 32nd week of pregnancy the patient delivered a female infant whose birthweight and Apgar score were normal. The infant did not have any anomalies. The woman finished her treatment in puerperium and she received three cycles of docetaxel. The patient has been receiving vinorelbine (one cycle every 2 weeks) for 2 years; her last follow-up was good and showed that the progression of the metastases had stopped. The daughter's psychophysical development was normal.

Adult↗
PubMed2000

Computer-assisted analysis of molecular mimicry between human papillomavirus 16 E7 oncoprotein and human protein sequences.

The immunology of human papillomavirus (HPV) infections has peculiar characteristics. The long latency for cervical cancer development after primary viral infection suggests mechanisms that may aid the virus in avoiding the host immunosurveillance and establishing persistent infections. In order to understand whether molecular mimicry phenomena might explain the ability of HPV to avoid a protective immune response by the host cell, sequence similarity between HPV16 E7 oncoprotein and human self-proteins was examined by computer-assisted analysis. Data were obtained showing that the HPV16 E7 protein has high and widespread similarity to several human proteins involved in a number of critical regulatory processes. In addition, multiple identical and different E7 peptide motifs are present in the same human protein. Thus, sharing of common motifs between viral oncoproteins and molecules of normal cells may be one cause underlying the scarce immunogenicity of HPV infections. The hypothesis is advanced that synthetic peptides harbouring viral motifs not and/or scarcely represented in the host's cellular proteins may represent a valuable immunotherapeutic approach for cervical cancer treatment.

Amino Acid Motifs↗
PubMed1999

Carbohydrate metabolism in gestational diabetes: effect of chronic hypertension.

OBJECTIVE: To evaluate whether the coexistence of chronic hypertension and gestational diabetes mellitus (GDM) is characterized by a greater impairment of carbohydrate metabolism than GDM alone. METHODS: Carbohydrate metabolism of eight women with chronic hypertensive GDM and 15 normotensive women with GDM was evaluated in the third trimester using the oral glucose tolerance test (GTT) and hyperinsulinemic-euglycemic clamp technique. Controls were ten normotensive, glucose-tolerant, pregnant women in the third trimester. RESULTS: Insulin sensitivity of women with chronic hypertension and GDM was approximately twofold lower than those with GDM only (1.54+/-0.35 versus 4.15+/-0.31, P < .001) and approximately fivefold lower than controls (1.54+/-0.35 versus 7.65+/-0.66, P < .001). Women with chronic hypertension and concomitant GDM had higher insulin levels in response to GTT than controls (P < .001 repeated measures analysis of variance). In all subjects, mean arterial pressure (MAP) had a strong negative correlation with maternal insulin sensitivity (r = -0.62, P < .001). Significant correlation was also found between percent of body fat and insulin sensitivity (r = -0.53, P < .002). Those regressions were still significant when adjusted for percent of body fat and MAP. CONCLUSION: Gravidas with chronic hypertension and GDM are more insulin resistant than those with GDM alone. Blood pressure, in a population of pregnant women with normal and abnormal carbohydrate metabolism, is a stronger predictor of insulin resistance than adiposity.

Adult↗
PubMed1999

Molecular mimicry of phage displayed peptides mimicking GD3 ganglioside.

We have analyzed sequence homologies between nonimmunogenic phage displayed peptides mimicking GD3 ganglioside and human/mouse self-proteins. The GD3 ganglioside phagotopes showed homology to proteins involved in carbohydrate metabolism/transport. Besides this expected homology, molecular mimicry of critical regulatory proteins was found. These data contribute to our understanding of the structural relatedness of antigenic determinants defined by specific anti-GD3 monoclonal antibodies and, in addition, suggest that molecular mimicry might explain the nonimmunogenicity of these peptides otherwise characterized by specificity to the mAb counterpart. We conclude that construction of peptides harboring motifs absent or scarcely represented in endogenous self-proteins might be a useful approach in melanoma immunotherapy.

Amino Acid Sequence↗
PubMed1999

Gestational hypertension but not pre-eclampsia is associated with insulin resistance syndrome characteristics.

The aim of this study was to assess whether the metabolic characteristics of insulin resistance syndrome are present in pre-eclamptic (PE), gestational (GH) and chronic hypertensive (CH) pregnancies. Glucose and insulin serum concentrations, both fasting and after oral administration of a glucose tolerance test, were evaluated in 26 hypertensive pregnant women (10 PE, 10 GH and six CH patients) and in 10 healthy controls during the third trimester of gestation. Insulin sensitivity was assessed using the hyperinsulinaemic-euglycaemic clamp technique. The plasma concentrations of triglyceride (TG), high density (HDL), low density (LDL), and very low density (VLDL) lipoprotein cholesterol, apolipoproteins AI and B, and non-esterified fatty acid (NEFA) were also measured. Women with GH exhibited approximately 40% lower steady-state insulin sensitivity index (ISI) compared to controls (3.75 versus 6.34, P < 0.03), as well as approximately 33% higher mean plasma TG (3.57 versus 2.68 mmol/l, P < 0.01), and approximately 69% higher mean NEFA (0.59 versus 0.35 mmol/l, P < 0.01). Women with PE showed similar ISI but reduced insulin and glucose areas under curve compared to controls (P < 0.006, P < 0.0005 respectively). Women with PE also had higher HDL-cholesterol and apo-AI than controls. Patients with CH had similar lipid and carbohydrate metabolism to control subjects. In conclusion, women with GH exhibit metabolic features similar to those of patients with insulin resistance syndrome, suggesting that similar abnormalities could be involved in the pathogenesis of these disorders. In contrast, our data do not support an association between insulin resistance syndrome and hypertension in pregnant women with PE and chronic hypertension.

Adult↗
PubMed1999

Dentin permeability after toothbrushing with different toothpastes.

PURPOSE: To evaluate the interaction of smear layer produced during brushing and dentifrice particles. MATERIALS AND METHODS: Dentin disks were obtained from extracted human third molars. Dentin permeability was evaluated using a hydraulic pressure apparatus working at 1 psi of pressure. After preparation, each sample was connected to the hydraulic pressure apparatus to evaluate the permeability of dentin with the smear layer produced during specimen preparation. After 5 min of measurements dentin was etched with 37% phosphoric acid gel for 2 min, washed and gently dried with cotton to measure the permeability after smear layer removal. This was done to measure the maximum permeability of each specimen (expressed as 100%). Then a second smear layer was produced using a #400 carbide paper under water for 1 min. Dentin permeability of the smear layer covered dentin was then measured, and expressed as a percent of the maximum permeability of that specimen, permitting each specimen to serve as its own control. The three toothpastes used (Merfluan powder, Merfluan paste and Fluorigard) were applied on dentin surfaces using a small sponge to completely cover the dentin surface. After 5 s, each sample was connected to a mechanical device and brushed under water for 3 min with constant pressure of 250 gr using a Colgate medium toothbrush. After this treatment, each sample was gently washed with tap water, gently air dried for 3-5 s and connected with the pressure apparatus to remeasure the permeability after brushing. For SEM examination of dentin before and after treatment with toothpaste and brushing, each dentin and enamel sample was fixed in 2% buffered glutaraldehyde. RESULTS: Dentin permeability proved unaffected by dentifrice treatments. SEM observations demonstrated the presence of dentifrice particles on dentin surface and inside dentin tubules. Smear plugs produced during dentin brushing were not removed by dentifrices.

Dentin↗
PubMed1998

Effect of maternal carbohydrate metabolism on fetal growth.

OBJECTIVE: To determine the effect of maternal carbohydrate metabolism and anthropometric characteristics on fetal growth. METHODS: Eight pregnant women in the third trimester with unexplained fetal growth restriction (FGR) and 11 women with normal pregnancies in the third trimester were evaluated for maternal carbohydrate metabolism, using oral glucose tolerance tests and hyperinsulinemic-euglycemic clamps. These data and maternal anthropometric characteristics subsequently were related to relative birth weight, defined as observed birth weight x 100/50th percentile birth weight. RESULTS: The women with FGR pregnancies were more insulin sensitive than were controls (21.6+/-4.4 versus 16.7+/-4.8 micromol/kg x min, P < .05) and showed reduced insulin and glucose areas under the curve (96,293+/-25,870 versus 145,291+/-49,356 pmol/L, P < .03; 1057.0+/-184.7 versus 1210.1 +/-85.9 mmol/L, P < .05, respectively). No differences were seen in fasting plasma glucose, insulin and human placental lactogen samples, age, height, pregravid weight, weight gain, and parity. In all patients, maternal insulin sensitivity and weight gain correlated well with relative birth weight (r =-.65, P < .002; r=.68, P < .001, respectively). When the same analysis was computed separately in the groups, insulin sensitivity exhibited a strong negative correlation with relative birth weight in the FGR group but not in controls (r=-.84, P < .007; r=-.54, P=.08, respectively). Conversely, in control women the best correlation between relative birth weight and the other variables studied was seen with maternal weight gain (r=.82, P < .002). CONCLUSION: Women with unexplained FGR have a different glucose metabolic pattern than do normals. We speculate that increased insulin sensitivity leads to a reduction in metabolic substrates for fetal growth.

Adult↗
PubMed1997

Enhanced expression of initiator TRNA(Met) in human gastric and colorectal carcinoma.

Transfer RNA isoaccepting species are differentially expressed at different times during development, differentiation, growth, aging, and carcinogenesis processes. It has been suggested that alterations in tRNA patterns might be mechanistically important in modulating gene expression during the various physiological/pathological cellular stages. As part of a study to investigate the possible mechanisms by which alterations of translational machinery can start and/or sustain carcinogenic cell proliferation, in this communication we report analysis of tRNA distribution in two gastro-intestinal human tumors. The qualitative and quantitative data obtained for cellular tRNA distribution put into evidence a shift in the tRNA population with increased level of initiator tRNA(Met) in the malignant tissues. This observation confirms previous data obtained on experimental carcinogenesis models and suggests the possibility of specific involvement of tRNA changes in protein synthesis initiation during tumorigenesis.

Chromatography, High Pressure Liquid↗
PubMed1997

[Treatment of dentin sensitivity with stannous fluoride gel. Electron microscopic study and evaluation of dentin permeability].

Dentine hypersensitivity still represent a major clinical problem only partially solved. The presence of exposed opened dentinal tubules has been demonstrated increase the dentine permeability and it is the responsible for pain and sensitivity. Stannous fluoride solution has been recently proposed to reduce dentine hypersensitivity. The aim of the present study was to evaluate the dentinal permeability of a new stannous fluoride gel proposed for the therapy of dentine hypersensitivity. Human extracted teeth have been used and mounted and connected with a hydraulic pressure apparatus working at 1 psi (70 cm of water pressure). It was calculated the permeability of untreated smear layer, treated smear layer (after gel application) and after acidic treatment. It was observed that gel treatment was able to reduce dentine permeability. Scanning electron microscopy demonstrated the presence of a homogeneous smear layer after treatment with gel. This in vitro study confirms that stannous fluoride treatment has the capacity to modify dentine permeability of sensitive dentine.

Dentin↗