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Biomedical subjects

G Preti

Publications and source records attributed to G Preti.

At least 37 records · Page 2Linked to original sources
PubMed1999

Bone density in human dentate and edentulous mandibles using computed tomography.

Mandibular bone density, vertebral density and resorption of the edentulous ridge were correlated in a group of 17 partially edentulous subjects. Bone density was quantified by Quantitative Computerized Tomography; resorption was evaluated on panoramic radiographs. Mean bone density in dentate areas was significantly higher than that in edentulous areas; mandibular bone density was not found to relate significantly to vertebral bone density, nor to ridge resorption. In programming osseointegrated implants in the partially edentulous mandible, CT may give a more accurate evaluation of trabecular bone. However, further studies are necessary to clarify its clinical utility.

Adult↗
PubMed1998

Identification and immunohistochemical localization of protein precursors to human axillary odors in apocrine glands and secretions.

OBJECTIVES: To determine the cellular localization in male and female axillary tissue for apocrine secretion odor-binding proteins 1 (ASOB1) and 2 (ASOB2) and the electrophoretic pattern of female apocrine proteins and to begin characterization of the ASOB1 protein. DESIGN: Immunohistochemical techniques were used with biopsy samples from axillary tissue of male and female subjects. Immunological techniques and microsequencing were used to characterize several of the proteins in male and female apocrine secretions. SETTING: A university medical center. PARTICIPANTS: Healthy male and female volunteers who donated apocrine secretions and/or axillary tissue. RESULTS: Specific immunoreactivity was localized only to the apocrine glands in both sexes. Furthermore, only preabsorption with a mixed apocrine secretion sample eliminated all immunoreactivity. The electrophoretic pattern of proteins in female apocrine secretions is similar to that in male secretions. Western blotting of the separated proteins from female samples using serum samples containing antibodies to ASOB1 and ASOB2 yielded identical results to those found with separated proteins from male samples. Partial sequence data obtained from the N-terminus of ASOB1 suggested that it shares homology with the alpha-chain of apolipoprotein J (Apo J). Apocrine secretion odor-binding protein 1 is not immunologically similar to ApoJ, but 2 other apocrine secretion proteins are. CONCLUSIONS: Male and female subjects appear to have the same glycoprotein carriers for (E)-3-methyl-2-hexenoic acid localized to the apocrine glands. The N-terminal sequence for ASOB1 may be homologous to Apo J, but it is not immunologically similar to it. However, 2 other proteins in the apocrine secretion appear to be the monomer and dimer forms of Apo J.

Adult↗
PubMed1998

Oral stereognosis in edentulous subjects rehabilitated with complete removable dentures.

Oral stereognosis was analysed in a group of edentulous subjects rehabilitated with complete removable dentures. Stereognosis was evaluated with and without the denture in place. The results showed that the older subjects had poorer stereognostic ability than the younger ones, whereas the duration of edentulism appeared not to influence this ability. The presence of a correct prosthetic rehabilitation appeared to improve stereognostic ability. Subjects with poorer stereognostic ability appeared more satisfied with their rehabilitation than did those with better stereognostic ability.

Age Factors↗
PubMed1998

Implant anchored complete mandibular denture: evaluation of masticatory efficiency, oral function and degree of satisfaction.

Masticatory efficiency, oral function and degree of satisfaction with the treatment received were analysed in a group of fully edentulous patients with severe atrophy of the mandibular bone, rehabilitated with complete removable dentures, before and after anchoring the dentures to osseointegrated implants. Masticatory efficiency increased significantly and chewing cycles increased in amplitude after anchoring the denture. The component of the chewing cycle that most influenced the increase in functional area was the lateral one. A correlation was found between the increase in the lateral component of the chewing cycle and the increased masticatory efficiency achieved with implant-anchored dentures. The degree of satisfaction with their rehabilitation reported by the subjects was correlated neither to increased masticatory efficiency nor to improved oral function.

Aged↗
PubMed1998

All-ceramic restorations: an overview.

Advantages and disadvantages of metal-ceramic and all-ceramic restorations are reviewed particularly from the aesthetic point of view. All-ceramic restorations offer the best results because they let the light through optimally. In constructing all-ceramic crowns on teeth which have been endodontically treated, the material used to rebuild the pin-abutments must be taken into consideration if the best aesthetic results are to be achieved. Materials which, because of their translucent characteristics, are the most aesthetic alternatives to metal alloy pin-abutments in rebuilding teeth which have been endodontically treated, are then described.

Aluminum Silicates↗
PubMed1996

A human axillary odorant is carried by apolipoprotein D.

The characterization of the source of the odor in the human axillary region is not only of commercial interest but is also important biologically because axillary extracts can alter the length and timing of the female menstrual cycle. In males, the most abundant odor component is known to be E-3-methyl-2-hexenoic acid (E-3M2H), which is liberated from nonodorous apocrine secretions by axillary microorganisms. Recently, it was found that in the apocrine gland secretions, 3M2H is carried to the skin surface bound to two proteins, apocrine secretion odor-binding proteins 1 and 2 (ASOB1 and ASOB2) with apparent molecular masses of 45 kDa and 26 kDa, respectively. To better understand the formation of axillary odors and the structural relationship between 3M2H and its carrier protein, the amino acid sequence and glycosylation pattern of ASOB2 were determined by mass spectrometry. The ASOB2 protein was identified as apolipoprotein D (apoD), a known member of the alpha2mu-microglobulin superfamily of carrier proteins also known as lipocalins. The pattern of glycosylation for axillary apoD differs from that reported for plasma apoD, suggesting different sites of expression for the two glycoproteins. In situ hybridization of an oligonucleotide probe against apoD mRNA with axillary tissue demonstrates that the message for synthesis of this protein is specific to the apocrine glands. These results suggest a remarkable similarity between human axillary secretions and nonhuman mammalian odor sources, where lipocalins have been shown to carry the odoriferous signals used in pheromonal communication.

Adult↗
PubMed1996

Development of nerve fibres in the temporomandibular joint of the human fetus.

The development of nerve fibres in the temporomandibular joint (TMJ) in relation to the development of bone, muscle and fibre components was investigated in human fetuses ranging from 9 weeks of gestation to birth. Immunohistochemistry for the glia-associated protein S-100 and for the neuro-specific marker protein gene product 9.5 (PGP 9.5) were used; specimens were compared to specimens of adult TMJ capsule and disc. At 9-10 weeks, a small number of neural elements are already present in the connective tissue around the joint and in the mesenchyme between the two articular blastemas from which the disc will differentiate. By 19 weeks many nerve fibres are clearly visible. Immunohistochemical results suggest diffuse disc innervation extending along the entire disc but not in the thin central area. More complex structures, i.e. encapsulated corpuscles, were also seen. The fetal disc appears highly innervated compared to adult tissue; already at this developmental stage morphology and distribution of nerves and corpuscles in the joint capsule are comparable to those in the adult joint. It may be concluded that the innervation of the TMJ is detectable from the end of the second month and that it develops fully between the third and the fifth month of gestation. Nerve endings in the disc are most numerous at 20 weeks, after which a progressive reduction, possibly secondary to the growth of articular tissues, is observed throughout the last trimester of fetal life and into adult life. The innervation of the lateral pterygoid muscle, on the contrary, is much less than that seen in adult muscles, even at full-term.

Adult↗
PubMed1996

Changes in the density of protein gene product 9.5-immunoreactive nerve fibres in human oral mucosa under implant-retained overdentures.

Reduced oral sensitivity and impaired masticatory cycles have been demonstrated in edentulous humans wearing removable dentures, and there is some evidence that these patients have a decreased innervation of the oral mucosa. Clinical and electrophysiological evidence shows that sensory performance improves after oral rehabilitation with implant-retained overdentures. The aim of this study was to compare the density of mucosal innervation in edentulous patients with that in dentate controls and to evaluate changes in the number or type of sensory receptors following placement of endosseous implants in these edentulous individuals. The mucosal innervation was evaluated by immunohistochemical assays for the neurospecific marker protein gene product 9.5, and the innervation pattern was compared with that of dentate controls. Morphometric analysis of the immunohistochemical material demonstrated a decrease in numbers of sensory receptors in the mucosa of edentulous patients and a significant increase in the number of nerve fibres in the mucosa covering the distal edentulous mandibular ridges supporting the prostheses after implant-retained rehabilitation. In contrast, there were only minor increases in the number of nerves in the peri-implant mucosa. These changes in innervation appear to be related either to the new biomechanical situation created by implant support, which favours more physiological tissue conditions, or to an adaptive mechanism in the peripheral processing of sensory stimuli. These changes may explain, at least partially, the clinically observed differences in sensory skills before and after implant placement.

Adaptation, Physiological↗
PubMed1996

Histological changes in edentulous oral mucosa under implant-supported overdentures.

The microscopic characteristics of the mucosa covering the alveolar ridge that supports a complete denture have long been studied. In this paper, any histological changes in mucosa loaded by a denture before and after a denture has been anchored by implant onto the bone were followed. The results suggest that mechanical loads improve trophism of mucosa, and that fixing a denture to implants leads to a more uniform distribution of loads.

Aged↗
PubMed1996

Oral conditions and aptitude to receive implants in patients with removable partial dentures: a cross-sectional study. part I. oral conditions.

The relationship between a removable partial denture (RPD) and damage caused to residual oral structures is the subject of on-going research. A group of patients wearing RPD, treated in the same way in the same department, were recalled to evaluate their oral hygiene and to compare the clinical condition of abutment teeth with that of non-abutment teeth. The study shows that most patients were unable to maintain high standards of oral hygiene. In the group of patients with non-optimal hygiene the clinical condition of abutment teeth was worse than that of non-abutment teeth. In the group of patients with optimal oral hygiene the condition of abutment teeth and non-abutment teeth was almost identical. To increase the standards of oral hygiene it is strongly advisable to recall and follow up patients on a regular basis.

Aged↗
PubMed1996

Oral conditions and aptitude to receive implants in patients with removable partial denture: a cross-sectional study. Part II Aptitude.

The aim of this study was to evaluate the possibility of replacing removable partial denture (RPD) with fixed partial dentures on osseointegrated implants in a selective group of patients with partially edentulous lower jaws. Forty patients were evaluated to receive implants. Twenty-three patients showed a precarious oral hygiene, five patients refused the treatment (being satisfied with their RPD), six refused for economic reasons, three patients refused for fear and scepticism, one for long duration of therapy, and one was not treated because of a very marked atrophy of the alveolar crest. Finally, one patient was treated with implants. For these reasons, at the present time implants are not an appropriate treatment for introduction into large-scale public health programmes and RPD must still be considered a valid therapeutic procedure.

Adult↗
PubMed1995

Proteinaceous precursors of human axillary odor: isolation of two novel odor-binding proteins.

The characteristic odor which arises in the human axillary region consists of volatile C6-C11 acids with the most abundant being (E)-3-methyl-2-hexenoic acid (E-3M2H). This acid, as well as several other components of the characteristic axillary odor, can be liberated from the odorless, aqueous soluble components of apocrine secretion by either saponification or bacteriolysis. It is therefore likely that a major characteristic odor is being carried to the skin surface bound to a water soluble precursor where it is liberated by axillary bacteria. The individual proteins found in apocrine secretions were separated, isolated and hydrolyzed with the resultant hydrolyzates analyzed by gas chromatography/mass spectrometry. These studies demonstrated that 3M2H was liberated from 2 proteins with apparent molecular mass of 26 and 45 kilodaltons: Apocrine Secretion Odor-Binding Protein 1 and 2, respectively (ASOB1 and ASOB2). Antisera to these proteins were prepared and used to examine a variety of other body fluids. Several fluids contained an immunoreactive protein with the same electropheretic migration pattern as the 45 KDa protein. Three of these body fluids (tears, nasal secretions and saliva) were separated into aqueous and organic soluble fractions and hydrolyzed to demonstrate that 3M2H could be liberated from the aqueous soluble materials. These results suggest interesting parallels between non-human mammalian odors used as chemical signals and human axillary odor. Previous studies have suggested the axillae as a source of human primer-type pheromones; consequently, if the odors which characterize the underarm are responsible for the pheromonal activity, then the chemistry involved may be similar to that in other mammalian chemical communication systems where proteins act as carriers of one or more chemical signals.

Adult↗
PubMed1995

Cross-adaptation of sweaty-smelling 3-methyl-2-hexenoic acid by a structurally-similar, pleasant-smelling odorant.

Cross-adaptation has been interpreted as a measure of the degree to which odors share common sensory channels. How structural similarity, in the absence of perceptual similarity, influences cross-adaptation is unknown. The present study assessed cross-adaptation by structurally similar, but perceptually different, odorants. Magnitude estimates for a 10:1 mixture of (E)- and (Z)-3-methyl-2-hexenoic acid (3M2H), a principal component of human underarm odor, decreased following adaptation to a mixture of (E)- and (Z)-ethyl esters of 3M2H (EE3M2H), which possess a pleasant, fruity odor. Cross-adaptation was asymmetric; adaptation to 3M2H did not significantly affect the perceived intensity of EE3M2H. By contrast, there was no significant cross-adaptation between 3M2H and the fruity-smelling ethyl esters of its homologues, 3-methyl-2-octenoic acid (EE3M20) and 3-methyl-2-pentenoic acid (EE3M2P). Similarity ratings revealed no differences among the three ethyl esters in their perceptual similarity to 3M2H (i.e. all were rated equally dissimilar to 3M2H). Molecular modeling studies revealed no difference in the charge distribution of these molecules. Rather, differences in the shape and size of the hydrophobic part of the molecule may determine the extent of cross-adaptation. These results demonstrate that structurally-similar, yet perceptually-distinct, odorants may cross-adapt and suggest that the extent of cross-adaptation may be affected by the degree of structural, as well as perceptual, similarity.

Adaptation, Physiological↗
PubMed1994

Limonene in expired lung air of patients with liver disease.

As part of an effort to examine the relationship between chemosensory disturbance and oral chemistry, we analyzed expired lung air samples from a series of 24 patients with liver disease and 24 healthy controls using gas chromatography-mass spectrometry. Compared to samples from controls, lung air from patients with liver disease contained unusually high levels of limonene, a monoterpene that is a major component of the essential oil of citrus fruits (0.1 vs 7.0 micrograms/20 liters for controls and patients). Only half the patients showed high levels of limonene. Patients with noncholestatic liver disease were significantly more likely to have elevated lung air limonene levels than those with cholestatic liver disease (0.2 vs 13.8 micrograms/20 liters). Responses to food frequency and dietary behavior questionnaires indicated a pattern of diet selection and food preferences that were consistent with a dietary origin for the limonene in these patients.

Air↗
PubMed1994

Monitoring of the discrimination threshold for interocclusal thicknesses in rehabilitated edentulous patients.

Thirty-seven white Caucasian subjects with unsatisfactory dentures were tested for interocclusal thickness discrimination threshold. New dentures were prepared and the test was repeated on days 1, 4 and 90 (from delivery). Eight patients whose situation was still unsatisfactory were given osseointegrated implant anchored dentures and the test repeated at the same intervals. Results were analysed statistically. Improved denture fit was found to increase interocclusal sensitivity. Decreased sensitivity during follow-up might indicate the need to check denture fit.

Aged↗