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Biomedical subjects

M Luce

Publications and source records attributed to M Luce.

At least 19 recordsLinked to original sources
PubMed2004

SNOM and AFM microscopy techniques to study the effect of non-ionizing radiation on the morphological and biochemical properties of human keratinocytes cell line (HaCaT).

In this study we have employed atomic force microscopy (AFM) and scanning near-field optical microscopy (SNOM) techniques to study the effect of the interaction between human keratinocytes (HaCaT) and electromagnetic fields at low frequency. HaCaT cells were exposed to a sinusoidal magnetic field at a density of 50 Hz, 1 mT. AFM analysis revealed modification in shape and morphology in exposed cells with an increase in the areas of adhesion between cells. This latter finding was confirmed by SNOM indirect immunofluorescence analysis performed with a fluorescent antibody against the adhesion marker beta4 integrin, which revealed an increase of beta4 integrin segregation in the cell membrane of 50-Hz exposed cells, suggesting that a higher percentage of these cells shows a modified pattern of this adhesion marker.

Cell Adhesion↗
PubMed2001

Spectroscopic scanning near-field optical microscopy with a free electron laser: CH2 bond imaging in diamond films.

Hydrogen chemistry in thin films and biological systems is one of the most difficult experimental problems in today's science and technology. We successfully tested a novel solution, based on the spectroscopic version of scanning near-field optical microscopy (SNOM). The tunable infrared radiation of the Vanderbilt free electron laser enabled us to reveal clearly hydrogen-decorated grain boundaries on nominally hydrogen-free diamond films. The images were obtained by SNOM detection of reflected 3.5 microm photons, corresponding to the C-H stretch absorption, and reached a lateral resolution of 0.2 microm, well below the lambda/2 (lambda = wavelength) limit of classical microscopy.

Journal Article↗
PubMed1999

Non-specific nasal provocation test with histamine. Analysis of the dose-response curve.

Non-Specific Nasal Hyper-reactivity (NSNH) is described as a clinical condition characterized by the presence of rhinitic symptoms that are a consequence of non-specific stimulations. Because of its effects on vascular, epithelial, and glandular receptors, NSNP Test (NSNPT) with histamine allows the study of NSNH. The aims of this study are 1. to analyze the behavior of NSNH both in non-allergic chronic vasomotory patients and in healthy control subjects 2. to correlate total nasal resistance(TNR) to each dosage of histamine to derive the dose/response curves and 3. to study these curves to analyze and possibly define different stages according to the intensities of response of NSNH. We have studied 26 subjects affected by non-allergic vasomotor rhinitis and 10 healthy control subjects. We sprayed a NSNPT with histamine-phosphate (0.2-0.3-0.4-0.5-0.6-0.8 mg) in different sessions to avoid accumulation phenomena. Five minutes before and five minutes after each challenge, TNR was determined by active anterior rhinomanometry. TNR was correlated to the doses of histamine by an empirical equation. The most important results of this study are as follows: a) the variation of TNR follows a model of exponential curve, b) it is possible to classify NSNH, as a function of the regression b coefficient belonging to the empirical equation used, in reactivity classes, c) from one reactivity class to another, post-stimulation TNRs double; 0.5 mg of histamine of the NSNPT is the optimal dose, d) there is an overlap between the responses of some normal subjects and rhinopathic patients that will be the subject of a further study. Finally, our data suggest that, in a future perspective, it is possible to use the NSNPT with histamine for diagnostic, prognostic and therapeutic control purposes.

Adult↗
PubMed1997

BRCA1 sequence analysis in women at high risk for susceptibility mutations. Risk factor analysis and implications for genetic testing.

CONTEXT: A mutation in the BRCA1 gene may confer substantial risk for breast and/or ovarian cancer. However, knowledge regarding all possible mutations and the relationship between risk factors and mutations is incomplete. OBJECTIVES: To identify BRCA1 mutations and to determine factors that best predict presence of a deleterious BRCA1 mutation in patients with breast and/or ovarian cancer. DESIGN: A complete sequence analysis of the BRCA1 coding sequence and flanking intronic regions was performed in 798 women in a collaborative effort involving institutions from the United States, Italy, Germany, Finland, and Switzerland. PARTICIPANTS: Institutions selected 798 persons representing families (1 person for each family) thought to be at elevated a priori risk of BRCA1 mutation due to potential risk factors, such as multiple cases of breast cancer, early age of breast cancer diagnosis, and cases of ovarian cancer. No participant was from a family in which genetic markers showed linkage to the BRCA1 locus. MAJOR OUTCOME MEASURES: Sequence variants detected in this sample are presented along with analyses designed to determine predictive characteristics of those testing positive for BRCA1 mutations. RESULTS: In 102 women (12.8%), clearly deleterious mutations were detected. Fifty new genetic alterations were found including 24 deleterious mutations, 24 variants of unknown significance, and 2 rare polymorphisms. In a subset of 71 Ashkenazi Jewish women, only 2 distinct deleterious mutations were found: 185delAG in 17 cases and 5382insC in 7 cases. A bias in prior reports for mutations in exon 11 was revealed. Characteristics of a patient's specific diagnosis (unilateral or bilateral breast cancer, with or without ovarian cancer), early age at diagnosis, Ashkenazi Jewish ethnicity, and family history of cancer were positively associated with the probability of her carrying a deleterious BRCA1 mutation. CONCLUSIONS: Using logistic regression analysis, we provide a method for evaluating the probability of a woman's carrying a deleterious BRCA1 mutation for a wide range of cases, which can be an important tool for clinicians as they incorporate genetic susceptibility testing into their medical practice.

Breast Neoplasms↗
PubMed1997

Homozygous inactivation of the NF1 gene in bone marrow cells from children with neurofibromatosis type 1 and malignant myeloid disorders.

BACKGROUND: The risk of malignant myeloid disorders in young children with neurofibromatosis type 1 is 200 to 500 times the normal risk. The gene for neurofibromatosis type 1 (NF1) encodes neurofibromin, a protein that negatively regulates signals transduced by Ras proteins. Genetic and biochemical data support the hypothesis that NF1 functions as a tumor-suppressor gene in immature myeloid cells, but inactivation of both NF1 alleles has not been demonstrated in leukemic cells from patients with neurofibromatosis type 1. METHODS: Using an in vitro transcription and translation system, we screened bone marrow samples from 18 children with neurofibromatosis type 1 and myeloid disorders for NF1 mutations that cause a truncated protein. Mutations were confirmed by direct sequencing of genomic DNA from the patients, and from their affected parents, in cases of familial neurofibromatosis type 1. RESULTS: Specimens from 9 of the 18 children contained abnormal peptide fragments, and truncating mutations of the NF1 gene were found in specimens from 8 of these children. The normal NF1 allele was absent in bone marrow samples from five of the eight children. We detected the same mutation in DNA from the affected parent of each child with familial neurofibromatosis type 1. CONCLUSIONS: Both alleles of the NF1 gene are inactivated in leukemic cells in some patients with neurofibromatosis type 1. NF1 appears to function as a tumor-suppressor gene in immature myeloid cells.

Bone Marrow↗
PubMed1997

Rapid identification of RT-PCR clones containing translation-terminating mutations.

The technique of in vitro transcription/translation (IVTT) has become an important method of detecting mutations that result in a prematurely terminated protein. Subsequent characterization of the mutations by cloning and sequencing the RT-PCR products, however, is often difficult and time consuming. This is due in large part to the altered metabolism to which transcripts containing translation terminating mutations are subject. Recent data has shown that mRNAs with nonsense or frame shift mutations are often selectively degraded, so that mutation bearing transcripts are significantly less abundant that wild-type transcripts and, after cloning, mutant clones are correspondingly scarce. We have developed a reliable method of identifying the cDNA clones containing translation terminating mutations by a 'second round' of IVTT. Clones are subjected to PCR and IVTT using similar conditions as in the initial IVTT reaction and are identified unequivocally as either wild-type or mutant prior to sequencing. Wasteful 'blind' sequencing is thus avoided as well as possible misidentification of taq polymerase errors as the mutation of interest.

Adaptor Proteins, Signal Transducing↗
PubMed1997

Low proportion of BRCA1 and BRCA2 mutations in Finnish breast cancer families: evidence for additional susceptibility genes.

One hundred breast and breast-ovarian cancer families identified at the Helsinki University Central Hospital in southern Finland and previously screened for mutations in the BRCA2 gene were now analyzed for mutations in the BRCA1 gene. The coding region and splice boundaries of BRCA1 were analyzed by protein truncation test (PTT) and heteroduplex analysis (HA)/SSCP in all 100 families, and 70 were also screened by direct sequencing. Contrary to expectations based on Finnish population history and strong founder effects in several monogenic diseases in Finland, a wide spectrum of BRCA1 and BRCA2 mutations was found. In the BRCA1 gene, 10 different protein truncating mutations were found each in one family. Six of these are novel Finnish mutations and four have been previously found in other European populations. Six different BRCA2 mutations were found in 11 families. Altogether only 21% of the breast cancer families were accounted for by mutations in these two genes. Linkage to both chromosome 17q21 (BRCA1) and 13q12 (BRCA2) was also excluded in a subset of seven mutation-negative families with four or more cases of breast or ovarian cancer. These data indicate that additional breast and breast-ovarian cancer susceptibility genes are likely to be important in Finland.

Adult↗
PubMed1996

Nonthoracotomy implantation of cardioverter defibrillators: preliminary experience with a defibrillation lead placed at the right ventricular outflow tract.

UNLABELLED: Although morbidity and mortality associated with defibrillator implantation using a nonthoracotomy approach have decreased as compared with a thoracotomy approach, defibrillation thresholds have been higher and fewer patients satisfied implant criteria. It may be possible to improve on the success of nonthoracotomy defibrillator implantation by the placement of a right ventricular (RV) outflow defibrillation lead. Implantable cardioverter defibrillator implantation data of 30 consecutive patients with clinical VT or VF were reviewed. Three defibrillation leads were routinely used. When either pacing threshold at the RV apex was inadequate (n = 2) or 18-J shocks were not successful in terminating VF in 3 of 4 trials (n = 8), the RV apex lead was positioned to the RV outflow tract attaching to the septum. Defibrillation testing was first performed with the RV apex lead in combination with CS, SVC, and/or subcutaneous leads. Twenty patients satisfied implant criteria with a defibrillation threshold of 13.5 +/- 3.6 J. In 7 of the 10 patients, whose RV lead was repositioned to the RV outflow tract, this lead in combination with SVC, CS, or subcutaneous leads produced successful defibrillation at < or = 18 J or in 3 of 4 trials. This approach improved the overall success of nonthoracotomy implantation of defibrillators from 69% to 90%. After a follow-up of 27 +/- 6 months, there was no dislodgment of the RV outflow tract defibrillation leads. CONCLUSIONS: This article reports the preliminary observation that placement of defibrillation leads to the RV outflow tract in humans was possible and without dislodgment. RV outflow tract offers an alternative for placement of defibrillation leads, which may improve on the success of nonthoracotomy defibrillator implantation.

Adult↗
PubMed1991

[The preparation for self-care of the diabetic client and his family].

UNLABELLED: Partial report, quanti-qualitative of action-research developed in the ward test/ambulatory of a University Hospital, extensive to home; integrating students, teachers and nursing team. OBJECTIVE: to establish standards to integrate hospital/community, seeking the man in the home circle, oppose the recovery/rehabilitation and the integration to work/society, considering the problems in the home/work and put into practice the proposition of the SUDS with extension to the hospital/community actions. Home visits raising the home conditions, family and/or community, consolidating their participation in the process. During the hospital stay nursing care was oriented to conduct the participation and realization of the care by the client and relatives happening the same in the ambulatory probation.

Brazil↗
PubMed1990

Brain responses to semantic incongruity in bilinguals.

Event-related potentials were examined in the first and second languages of bilinguals, and in monolinguals. Stimuli were anomalous sentences presented one word at a time on a CRT monitor. The principal dependent measure was the N400 component, and an accompanying frontal negativity, which provided an estimate of the amount of time the nervous system takes to determine the semantic incongruity of a given word. The results indicate that N400 latency is slightly, but significantly, delayed in bilinguals, with monolinguals having the shortest mean N400 latency, the first language of bilinguals next, and the second language of bilinguals longest. The frontal negativity varied in amplitude somewhat independently of the parietal N400. The amplitude of the frontal negativity was sometimes reduced in the second language, tending to be smaller in those subjects who used their second language the least. Neither N400 nor the frontal negativity varied as a function of age of acquisition of the second language. The results are discussed with reference to the relative automaticity of language in bilinguals, and the sensitivity of N400 to variations in the automaticity of language processing.

Adult↗
PubMed1989

Acute upper airway obstruction in rheumatoid arthritis of the cricoarytenoid joints.

We have reported two cases of acute, life-threatening upper airway obstruction due to previously unrecognized rheumatoid arthritis of the cricoarytenoid joints with severe acute and chronic deformities of the larynx. Attempted endotracheal intubation with the rigid laryngoscope failed in each case, resulting in the need for emergency tracheostomy. We recommend the use of the fiberoptic bronchoscope for elective or emergency endotracheal intubations in patients with severe rheumatoid arthritis involving the cervical spine and the larynx.

Acute Disease↗
PubMed1983

Oral health in children: prevention of dental caries.

Dental problems are common among children and adolescents in the United States. More than 90 percent of our youth have dental caries, malocclusions, injury to teeth and mouth and gum disease. However, it is possible to maintain oral health and prevent dental problems and, specifically, dental caries, through education and motivation. Nurses working with children and families are more frequently in a position to initiate a program for dental health than are members of the dental profession. We feel that it is essential in light of disease occurrence and current levels of dental caries, for nurses to incorporate oral health maintenance in their care of children in ambulatory and acute care settings.

Adolescent↗
PubMedDate not supplied

Non-specific hyperreactivity before and after nasal specific immunotherapy.

BACKGROUND: Specific local immunotherapy (SLIT) improves symptom scores for allergic rhinitis during treatment and after its conclusion, as confirmed by non-specific tests. However, the duration of clinical and instrumental improvement after discontinuing SLIT is unknown. OBJECTIVE: To evaluate the changes in the non-specific reaction time of patients with allergy to Dermatophagoides pteronissinus before and during 3 years of SLIT, and 6, 12, 18, and 24 months after discontinuing SLIT. MATERIAL AND METHODS: Sixteen patients were diagnosed by clinical history, positive skin test for D. pteronissinus, RAST, nasal provocation test (NPT) specific for D. pteronissinus, NPT with cold water solution. SLIT was administered by nasal spray. Patients were evaluated before, at 6, 12, 24, and 36 months of SLIT, and 6, 12, and 18 months after discontinuing SLIT. At the beginning of SLIT, the allergen concentration used was similar to that used in NPT. Maintenance doses were administered 3 times a week for 1 year and 2 times a week for 2 years. All patients kept a symptom diary. RESULTS: After the first year of SLIT, total nasal resistance (TNR) decreased sharply. TNR then remained constant at the end of the second year and decreased at the end of the third year of treatment. Discontinuation of SLIT did not produce evident variations in average TNR at 6 or 12 months, but 3/16 patients at 6 months and 9/16 patients at 12 months complained of symptomatic deterioration. The most evident deterioration was noted at the 18-month post-SLIT visit, in which TNR values were similar to those recorded at the onset of treatment. Positive response to stimulation and increased TNR were found after SLIT in 8/16 patients at 6 months, 13/16 at 12 months, 12/13 at 18 months, and 7/7 at 24 months. The symptom score indicated the return of symptoms. Twelve months after discontinuing SLIT, the patients complained about increased secretion and itching. The initial non-specific hyperreactivity, which had been present in all patients, was not evident in 68.7% after 3 years of SLIT, but persisted in a milder form in 31.3%. CONCLUSION: SLIT successfully reduced symptoms of D. pteronissinus sensitivity. Non-specific hyperreactivity was absent at the end of SLIT, but returned by 6 months after discontinuing SLIT. Therefore, SLIT did not maintain the clinical results achieved at the beginning of treatment for more than 12 months.

Administration, Intranasal↗
PubMedDate not supplied

Otorhinolaryngological aspects of HIV infections: personal experience.

The involvement of the ENT sphere in HIV infections is fairly common, but the relative manifestations, though not to be considered atypical, are not pathognomonic. The present study has been set up for the otoiatric assessment of a group of HIV patients and the correlation of ENT symptoms with the various stages of the disease. To this end, 60 patients were examined (35 belonged to groups 2-3 and 25 to group 4) of whom 50% were drug addicts, 36% homosexuals and 14% heterosexuals. All patients underwent a complete ENT examination as well as the assessment of hearing and vestibular function, of olfactory and taste functions, of respiratory and nasal mucociliary functions along with an anti-HIV antibody check of nasal secretion. Results showed a prevalence of otologic and rhinosinusal symptoms as well as cervical-facial swelling. Testing revealed a hearing loss of mainly conductive origin caused by otitis and tubal stenosis; vestibular hyporeflexia; mixed hyposmia and hypogeusia owing to the involvement of multiple cranial nerves; respiratory and mucociliary changes due to rhinitis and hypertrophy of the nasal mucosa. In all cases anti-HIV antibodies were found in nasal secretion. From a diagnostic point of view there was a prevalence of specific pathologies: oropharyngeal candidosis, stage 4; cervical lymphoadenopathy, stages 2-3; chronic rhinosinusitis, nasal vestibulitis and nosebleed; mainly chronic otitis media. All such manifestations suggest a marked involvement of ENT organs, which can be attributed to the anatomical characteristics of the area, with the relative diagnostic and prognostic implications of HIV infection.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Local treatment of aspecific nasal hyperreactivity with capsaicin.

Ten patients with vasomotor rhinitis underwent local treatment with capsaicin (30 micromol.), once per week for five weeks; controls were carried out at weekly intervals and 1, 3 and 6 months after therapy. Assessment was made using symptom score and nasal resistance scores both basal and subsequent to aspecific nasal provocation. Results showed abatement of symptoms, and reduction of nasal resistance and aspecific hyperreactivity already during the second week. This trend continued for six months, with endoscopic improvement also. Hence, this treatment proved to be efficient in reducing nasal reactivity.

Adolescent↗
PubMedDate not supplied

Local treatment of nasal polyposis with capsaicin: preliminary findings.

The inflammatory process triggered by the nasal hyperreactivity, whether specific or aspecific, presents three components: immunomediation-neurogenic-interconnection between the nervous and the immunitary systems. Neuropeptides (eg SP and CGRP) are among the agents responsible for neurogenic phlogosis and, in our opinion, they contribute towards the onset of polyps. Capsaicin, which acts on the C fibres, has been applied locally (30 microns) by the AA in 15 patients affected by aspecific nasal hyperreactivity with polyps, in the course of a double blind study with an equal number of patients. Treatment was given once a week for 5 consecutive weeks in order to evaluate the effect on both the hyperreactivity and the polyps. Before and after each session and at the 1- and 3-month controls the following tests were carried out: assessment of symptoms, nasal endoscopy, sizing of the polyps, aspecific nasal provocation test and nasal cytology. Apart from an improvement in symptoms and in nasal hyperreactivity, results showed a reduction in the size of the polyps even though accompanied by a gradual increase of eosinophiles which was not correlated to a degranulation process.

Adult↗