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Biomedical subjects

S Cavalieri

Publications and source records attributed to S Cavalieri.

At least 37 records · Page 2Linked to original sources
PubMed1989

Laser dentistry: root canal diagnostic technique based on ultraviolet-induced fluorescence spectroscopy.

A diagnostic technique to detect residual tissues at different levels of the root canal during an endodontic treatment is presented. The diagnostic system is based on ultraviolet-induced fluorescence spectroscopy and uses suitable optical fibers for local delivery of excitation light and to collect back fluorescence spectra. Spectra of root canal tissues have been obtained from split teeth by labeling with a fluorescent solution. Residual tissue can be discriminated in respect to healthy dentin because of their different spectral responses: the spectral shape of the first response shows a clear peak at 530 nm because of a selective absorption of the fluorescent dye, whereas for the second response, the spectral curve monotonically increases toward ultraviolet wave-lengths with no particular structure. This technique has been tested on unsplit teeth simulating operative conditions. A compact spectroscopic system has been devised that can be easily integrated in an excimer laser system to perform residual tissue detection during laser cleaning of the canals.

Fiber Optic Technology↗
PubMed1989

Whole-lung tomography in urologic malignancy.

The place of whole-lung tomography in urologic malignancy has not been established. We reviewed 88 cases of known or suspected urologic malignancy in which tomography was used. Most patients had renal, bladder, or testicular tumors. Of the 68 patients with negative screening chest roentgenograms, all but 2 had negative tomograms. One of these 2 patients had a normal chest film (the other had extrapulmonary metastasis), and he did not have the renal carcinoma initially suspected. Tomography discovered no metastases from urologic malignancy that was not already known about from the screening x-ray film. In 20 cases with a positive screening x-ray film, tomography was of limited value. It cleared two suspicious chest films and added information on extent of metastatic involvement in three. We conclude that whole-lung tomography adds little information not available by chest roentgenogram in our selected population, and with a negative screening chest film no additional chest study is needed.

Costs and Cost Analysis↗
PubMed1989

Calcitonin inhibition of growth hormone-releasing hormone-induced GH secretion in normal men.

Calcitonin has been shown to modulate pituitary hormone secretion in a variety of ways. In this study we examined the effects of a salmon calcitonin infusion on GHRH-induced GH secretion in 5 normal men. In addition, in vitro experiments were performed using primary cultures of rat anterior pituitary cells in order to examine whether there is a direct pituitary effect of CT. Infusion of CT significantly blunted the GH response to GHRH in all subjects without affecting basal GH secretion or plasma calcium levels. Infusion of CT was accompanied by significant increases in ACTH, beta-endorphin, cortisol and free fatty acid levels, and by a significant decrease in serum insulin levels. The addition of CT to primary cultures of rat pituitary cells did not alter basal or stimulated secretion of GH or ACTH. These results indicate that: 1) CT blunts the GH response to GHRH; 2) CT infusion results in the stimulation of the hypothalamic-pituitary-adrenal axis, and 3) this effect is probably exerted at the hypothalamic level, since no direct activity of CT was documented in vitro on either GH or ACTH secretion.

Adrenocorticotropic Hormone↗
PubMed1987

Cross reactions in radioimmunoassay: a mathematical model for correcting assay results, as exemplified by eliminating the interference of intact thyrotropin in an assay of its beta subunit.

To correct the results of a radioimmunoassay for beta-thyrotropin (TSH) subunit by eliminating the proportion ascribable to intact TSH, we have devised a method that experimentally reproduces the conditions under which the interference develops. Beta-TSH subunit was assayed in several preparations containing known concentrations of both beta-TSH and TSH. The TSH-induced overestimation of beta-TSH was linearly related to the concentration of antigen in the sample. At a constant concentration of TSH, therefore, the following equation is applicable: F = aE + b, where F is the measured (but overestimated) concentration of beta-TSH, E is the actual concentration of beta-TSH, and a and b are the slope and the intercept of the regression line, respectively. a and b, once expressed as a function of TSH, allow the correction of the overestimation. The analysis of the results according to the mass action and conservation laws shows that the antiserum is more avid for the interferent (intact TSH) than for the antigen (beta-TSH).

False Positive Reactions↗
PubMed1985

Cellular immunity against Salmonella typhi after live oral vaccine.

Seventeen adult volunteers were vaccinated orally with the live attenuated Salmonella typhi mutant strain Ty21a. Their peripheral blood mononuclear cells were tested at different times after vaccination for direct cell-mediated activity against bacteria, employing a simple short-term in vitro assay. It was observed that 16/17 of the vaccinated subjects acquired the capacity to express specific cellular immunity against S. typhi which lasted from 15 days to at least 3 years. The effector cell of the in vitro antibacterial activity was preliminarily characterized as a non-adherent T3+, T8-, T4+ lymphocyte. In parallel, mice immunized orally with S. typhimurium and proving resistant to reinfection were tested employing the same in vitro assay. Also in this case peripheral and, most important, intestinal lymphocytes were able to express cellular immunity against the agent of murine typhoid. It is concluded that administration of live oral vaccine against S. typhi results in the induction of specific cellular immunity which is expressed at the peripheral and, probably, also at the intestinal level.

Adult↗
PubMed1983

Propionibacterium acnes resistance to antibiotics in acne patients.

The minimal inhibitory concentration (MIC) of Propionibacterium acnes in seventy-five acne patients receiving long-term antibiotic therapy demonstrated the emergence of resistant strains. The mean MIC in thirty-three patients receiving long-term tetracycline was four to five times higher than that found in control groups of acne patients not receiving antibiotic therapy and controls free of acne. The average MIC for erythromycin was more than 100 times higher in those receiving long-term antibiotic therapy. In a second group of sixty-two patients, the clinical course and number of P. acnes were correlated with the presence of "resistant strains" defined as P. acnes with a tenfold increase in MIC to tetracycline or erythromycin. Patients with resistant strains had higher counts of P. acnes and clinically were not doing as well as those with sensitive strains.

Acne Vulgaris↗
PubMed1979

Detection of carriers and prenatal diagnosis for fucosidosis in Calabria.

A significant proportion of patients affected with fucosidosis have Italian ancestors. We assayed for alpha-fucosidase activity purified mononuclear cells and/or leukocytes obtained from 64 members of two large pedigrees from Calabria, in which seven children had been diagnosed as affected with fucosidosis. Of these 64 individuals, 22 were diagnosed as carriers, while the values for the remainder were within normal limits, indicating a clear bimodal distribution among individuals at risk. These data confirm that carrier detection for fucosidosis requires the measurement of alpha-L-fucosidase activity in purified mononuclear cells from peripheral blood. In addition, this program has made prenatal identification of an affected fetus possible.

Amniotic Fluid↗
PubMed1979

Relationship between alpha-L-fucosidase deficiency in plasma and alpha-L-fucosidase activity in leukocytes.

After testing a population sample of 185 hospitalized Italian children for the plasma alpha-L-fucosidase deficiency and establishing an approximate threshold value between heterozygotes and wild-type homozygotes, we analyzed by two statistical methods the distribution of the two genotypes. The results obtained by probit analysis agree with threshold and average values expected on the basis of the Hardy-Weinberg equilibrium. In addition, the level of alpha-fucosidase in leukocytes of 12 individuals with deficiency of alpha-fucosidase in plasma was found to be significantly lower than that of 61 controls (P less than 0.005). These results indicate that the mutation(s) causing a deficiency of alpha-fucosidase in plasma is (are) also expressed in leukocytes.

Carbohydrate Metabolism, Inborn Errors↗
PubMed1977

Sialidosis (mucolipidosis I).

The term "sialidosis" is suggested for the deficiency of alpha-neuraminidase activity in peripheral leukocytes and cultured fibroblasts which results in a considerable urinary excretion of sialyl-oligosaccharides. This defect was found in two siblings with a mild form of mucolipidosis I. 12 sialyl-acid rich oligosacharides have been isolated from the urine of the patients. The structure of ten of them has been determined. The studies of the patients show a remarkable variability of the clinical expression of this disease. The two siblings exhibited a progressive reduction of visual acuity, red-green blindness, a bilateral cherry red macular spot, punctate opacities of the lens, and minimal neurological symptoms. Morphologically, vacuolized lymphocytes, refringent inclusions in cultured fibroblasts, numerous cytoplasmatic inclusions containing a fine protein-like reticulum and some osmiophilic granules mainly in Kupffer's cells were found.

Adolescent↗
PubMedDate not supplied

Expression of the high-affinity laminin receptor (67 kDa) in normal human skin and appendages.

The interaction of cells with extracellular matrix components plays a significant role in the regulation of cell biology. Laminin is a large glycoprotein involved in fundamental interactions between cells and the basement membrane. Several cell surface receptors are responsible for cell-matrix interactions. The 67 kDa high affinity laminin receptor, 67LR, is involved in the adhesion of normal cells to the laminin network and is also associated with the metastatic phenotype of some tumoral cells. We have investigated the expression of laminin and of the 67LR in normal human skin using immunoperoxidase staining. Twenty samples of skin were analyzed. Antibody against laminin reacted in a continuous linear band at the dermal-epidermal junction, as well as basement membranes of hair follicles, sebaceous and eccrine sweat glands, and dermal blood vessels. The epidermis and the follicular epithelium were negative for laminin. The 67LR seemed not to be expressed on the basal surface of basal keratinocytes. The major expression of this receptor may be detected in the upper half of the spinous layer and in the granular layer. The cells of the outer root sheath in hair follicle showed the same immunohistochemical pattern described for epidermis. In sebaceous glands and in eccrine sweat glands the secreting epithelium was positive. Endothelial cells of dermal blood vessels were routinely positive for 67LR. We observed that the expression of the 67LR in normal human skin is mostly located in epidermal areas in which the keratinizing process was particularly advanced.

Adult↗
PubMedDate not supplied

[Mucolipidosis. biologic characteristics (author's transl)].

Mucolipidosis II is a severe inherited lysosomal storage disease characterized by profound psychomotor retardation, severe Hurler-like skeletal changes and normal urinary mucopolysaccharide excretion. Mucolipidosis II is a related disorder distinguished by its milder course, milder to absent mental retardation and survival to adult life. Cultivated fibroblasts from patients with both of these disorders display large inclusions on phase microscopy and reduced levels of many acid hydrolases. However, culture medium fibroblasts out the body fluids of affected patients show enormously elevated levels of these hydrolases. The lysosomal enzyme activities in serum, leukocytes, fibroblasts extracts and culture medium from seven patients with mucolipidosis II are similar to those found in four cases of mucolipidosis III. The findings of excessive excretion of sialyl-oligosaccharide in urine and of increased level of sialic acid compounds in cultured fibroblasts associated with a sialidase deficiency in leukocytes, fibroblasts and serum are discussed.

Child, Preschool↗