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Biomedical subjects

D Tripodi

Publications and source records attributed to D Tripodi.

At least 19 recordsLinked to original sources
PubMed2004

Brain magnetic resonance imaging, aerobic power, and metabolic parameters among 30 asymptomatic scuba divers.

The aim of the study was to evaluate the presence of cerebral lesions in asymptomatic scuba divers and explain the causes of them: potential risk factors associating cardiovascular risk factors, low aerobic capacity, or characteristics of diving (maximum depth, ascent rate). Experienced scuba divers, over 40 years of age, without any decompression sickness (DCS) history were included. We studied 30 scuba divers (instructors) without any clinical symptoms. For all of them, we carried out a clinical examination with fatty body mass determination and we questioned them about their diving habits. A brain Magnetic Resonance imaging (MRI), an assessment of maximal oxygen uptake, glycemia, triglyceridemia, and cholesterolemia were systematically carried out. Cerebral spots of high intensity were found at 33 % in the scuba diving group and 30 % in the control group. In the diving group, abnormalities were related to unsafe scuba-diving or metabolic abnormalities. In our study, we did not find a significant relationship between the lesions of the central nervous system, and the age, depth of the dives, number of dives, and ergometric performances (maximal oxygen uptake, V.O (2max), serum level of blood lactate). Nevertheless, we found a significant relationship between the lesions of the central nervous system and ascent rate faster than 10 meters per minute (r = 0.57; p = 0.003) or presence of high level of cholesterolemia (r = 0.6; p = 0.001). We found concordant results using the Cochran's Test: meaningful link between the number of brain lesions and the speed of decompression (Uexp = 14 < Utable = 43; alpha = 0.05, p < 0.01). We concluded that hyperintensities can be explained by preformed nitrogen gas microbubbles and particularly in presence of cholesterol, when the ascent rate is up to 10 meters per minute. So, it was remarkable to note that asymptomatic patients practicing scuba diving either professionally or recreationally, presented lesions of the central nervous system. This survey permitted us to highlight in a population of professional divers, neurological and also cardiovascular abnormalities (ventricular arrhythmias); although none of them present any symptoms today. It seems therefore important to us to propose in the future, for a better prevention of neurological injuries, a systematic follow-up by maximal oxygen consumption measure, brain MRI, and cholesterolemia. In the same way, our results suggest a modification of the diving tables with a maximal decompression rate at 9 m . mn (-1).

Brain↗
PubMed2004

Transforming growth factor-beta 1 (TGF-beta 1) expression in normal healthy pulps and in those with irreversible pulpitis.

AIM: To evaluate the Transforming Growth Factor-beta 1 (TGF-beta 1) expression in normal healthy pulps and in those with irreversible pulpitis. METHODOLOGY: Twenty-three normal, healthy pulps were removed from mandibular third molars, and 20 pulps were retrieved from teeth with irreversible pulpitis. TGF-beta 1 was evaluated in the odontoblastic and subodontoblastic layers, in the stromal cells (fibroblasts), and in the blood vessels. TGF-beta 1 expression was determined by evaluating 500 cells in the odontoblastic and subodontoblastic layers and 500 fibroblasts in the stroma for each specimen, and counting the number of positive cells. The number of the positive vessels was evaluated in 10 high power fields (HPF). In almost all cases, the cellular positivity was cytoplasmatic. Statistical analysis was performed using Mann-Whitney U- and Student's t-tests. RESULTS: A higher expression of TGF-beta 1 was found in the odontoblastic-subodontoblastic layer of the irreversible pulpitis specimens; this difference was statistically significant (P = 0.0002). No statistically significant difference was observed between the two groups in TGF-beta 1 expression in the stromal cells (P = 0.54) or in the vascular component (P = 0.94). CONCLUSIONS: The higher and statistically significant expression of TGF-beta 1 found in the odontoblastic-subodontoblastic layer of irreversible pulpitis specimens may indicate a role for TGF-beta 1 in the dentinal repair processes after pulp inflammation.

Adolescent↗
PubMed2004

Microbiological study and scanning electron microscopic analysis of root canal wall dentin following pumped Diodium Nd:YAG laser irradiation.

The capability of Nd:YAG laser in sterilizing root canals and the alterations of dentinal walls induced by laser treatment were investigated. Thirty root canals were infected by P. aeruginosa ATCC 27853 and thirty canals by A. naeslundii CH-12. Within each infection, 4 groups were selected on the basis of the treatment. Among them, 2 test groups (TGs) were treated by Nd:YAG laser at 15 Hz for 15 s, using 2 different settings: 1 Watt/70 Joule and 1.5 Watt/100 Joule, respectively (n = 10 each). The other 2 groups, used as controls (CGs), were: untreated (positive control, n = 5) and sterilized by 5.25% NaClO group (negative control, n = 5). Observations under scanning electron microscope (SEM) and quantitative bacterial counts were performed. These analyses were performed once per group after infections and treatments. Laser treatments significantly reduced the number of both bacteria. SEM investigation showed melting and crystallization of canal dentin over 1.5 W/100 J. Laser irradiation has a bactericidal effect but it does not completely sterilize the root canal as NaClO 5.25% solution does if the goal of treatment is also to avoid alterations of dentinal walls.

Actinomyces↗
PubMed2003

Human dental pulp vasculogenesis evaluated by CD34 antigen expression and morphological arrangement.

Vasculogenesis describes the process by which endothelial precursor cells form new blood vessels. To characterize the topography and the cellular processes underlying vascularization of human dental pulp, we examiend the expression of the human hematopoietic progenitor cell antigen CD34. Dental pulps, obtained from deciduous and permanent teeth, were morphologically examined at light- and electron-microscope levels and by expression of CD34. The findings indicate that vasculogenesis of dental pulp is a complicated process starting from single CD34(+) cells. These subsequently coalesce to form solid vascular cords inside the developing connective tissue, which later hollows. Pericytes were embedded within the fully formed microvessels' basement membrane. The presence of CD34(+) endothelial cells in permanent teeth reveals that the process of vasculogenesis persists into adult life, where it contributes to continuous adjustment of vessel and network structures in response to functional needs and dental tissue homeostasis.

Adolescent↗
PubMed2002

[Respiratory symptoms and ventilatory disorders among a group of cement workers in Morocco].

There are 8 cement works in Morocco employing 3 600 people and producing 8 million tons annually. The aim of our study is to determine the prevalence of respiratory symptoms and to propose some preventive measures. The study involved a group of workers of whom 280 were exposed to cement dust (who were further subdivided into three categories according to the intensity of exposure) and 73 who were not. It included a medical history with a standardised questionnaire, a clinical examination and spirometry. 65% of those exposed had clinical symptoms as opposed to 34.2% of the non-exposed. Cough, expectoration rhinitis, chronic bronchitis and asthma were significantly more common with incidences of 56.1%, 52.5%, 49.3%, 29.3% and 14.3% respectively in the exposed against 19.2%, 24.6%, 26%, 9.6% and 6.8% in the non-exposed. Among the exposed the prevalence of chronic bronchitis increased significantly with the degree of exposure, from 11.4% in category 1 to 41.6% in category 3. Age did not seem to influence the development of chronic bronchitis but on the other hand a smoking history of more than 10 years did. Exposure is responsible for the development of respiratory problems because among non smokers the exposed (55.6% are more symptomatic than the non-exposed (13.3%). Tobacco smoking potentiates the effects of occupational airborne contamination because exposed smokers (73.6%) and ex-smokers (67.8%) have more respiratory problems than exposed non-smokers (55.6%). The incidence of abnormalities of respiratory function is significantly higher in the exposed than in the non-exposed (32.5% against 13.7%). Among the exposed workers presenting disorders of ventilatory function 72.5% have no more than a disorder of the small airways or a slight deficit. Among the exposed the prevalence of impaired respiratory function is greater in smokers and ex-smokers (47.9% than in non-smokers (10.4%). Tobacco smoking augments the impairment of respiratory function. Prevention depends therefore on a programme of technical (collective and individual) and medical protection of the workforce.

Adult↗
PubMed2002

Cerec 3 for orthodontics: a tool for treating deep bite.

Bite-opening procedures are used in the early stages of orthodontic fixed treatment in order to: ease antero-posterior tooth movements; bracket the mandibular arch and level the Curve of Spee; prevent mandibular brackets from debonding; use regular straight archwires to proceed with treatment. For these purposes, removable or bonded biteplanes are universally recognized as very effective when the bite-opening is needed. Conventional orthodontic procedures include clinical solutions which effectively open the bite, but they all lack sufficient hygiene, comfort, and esthetics. The authors propose the use of the CAD-CAM technology with the Cerec 3 system (Sirona, Bensheim, Germany) to create an overcrown able to open the bite through clinical crown lengthening of the mandibular second premolars. The laboratory steps are described and the clinical efficacy is demonstrated with an orthodontic case report.

Adolescent↗
PubMed2001

Alkaline phosphatase activity in normal and inflamed dental pulps.

Alkaline phosphatase (ALP) seems to be important in the formation of mineralized tissues. High levels of ALP have been demonstrated in dental pulp cells. In the present study ALP activity was analyzed in normal healthy human dental pulps, in reversible pulpitis, and in irreversible pulpitis. Enzymatic ALP control values for the normal healthy pulps were 110.96+/-20.93. In the reversible pulpitis specimens the ALP activity increased almost eight times to 853.6+/-148.27. In the irreversible pulpitis specimens the values decreased sharply to 137.15+/-21.28 and were roughly equivalent to those seen in normal healthy pulps. The differences between the groups (control vs. reversible pulpitis and reversible pulpitis vs. irreversible pulpitis) were statistically significant. These results could point to a role of ALP in the initial pulp response after injury.

Acute Disease↗
PubMed2001

Aspartate aminotransferase activity in human healthy and inflamed dental pulps.

Aspartate aminotransferase (AST) seems to be an important mediator of inflammatory processes. Its role in the progression and detection of inflammatory periodontal disease has been increasingly recognized in recent years. In the present study AST activity was analyzed in normal healthy human dental pulps, in reversible pulpitis, and in irreversible pulpitis. Enzymatic AST activity showed that the control values for the healthy pulps were 4.8 +/- 0.7 units/mg of pulp tissue. In reversible pulpitis specimens the AST activity increased to 7.98 +/- 2.1 units/mg of pulp tissue. In irreversible pulpitis specimens the values decreased to 2.28 +/- 1.7 units/mg of pulp tissue. Differences between the groups (control versus reversible pulpitis and reversible pulpitis versus irreversible pulpitis) were statistically significant (p = 0.0015). These results could point to a role of AST in the early events that lead to development of pulpal inflammation.

Acute Disease↗
PubMed2001

How to improve digital dental radiograph reproducibility: an individualized technique.

Today, the advantages of the use of digital dental radiography as a valid alternative to conventional techniques are well known. In clinical dental practice, it can be useful to realize intraoral dental x-rays that can be compared, even after some years. The use of a conventional XCP instrument with the "long cone" technique helps to limit image distortion, but the comparison is poor. Moreover, in digital radiography, obtaining almost identical images is essential to superimpose them with dedicated software. The aim of the present work was to obtain fully superimposable and reproducible intraoral digital images through the use of an individual resin positioner. The laboratory phases are all described to create a system that enables exact placement of the digital sensor SIDEXIS (Sirona, Germany) in the mouth of the patient. The authors present a case report where the described technique is applied in the orthodontic field to evaluate molar distalization with a fixed appliance.

Equipment Design↗
PubMed2001

[Prevalence of respiratory problems in workers at two manufacturing centers of ready-made concrete in Morocco].

SETTING: Employees at factories for ready-made concrete are exposed to the dust emanating from the products (such as sand, gravel and cement); however, there have been few studies on the subject. METHODS: A retrospective cohort analysis was conducted in a male population: 120 employees working in cement production and 120 non-exposed civil servants working at the Casa-Anfa prefecture. Each employee underwent interview by standardised questionnaire, spirometry test and standard chest radiography. RESULTS: Statistical analysis of the results revealed an increase in the prevalence of exposed symptomatic subjects compared to non-exposed subjects (57.5% vs. 24.2%) and increased prevalence of all of the symptoms: cough (15.8% vs. 15%), dyspnea (21.6% vs. 5%), chronic bronchitis (11.7% vs. 6.7%), asthma (14.2% vs. 7.5%), rhinitis (40% vs. 19.2%), conjunctivitis (48.3% vs. 10%) and dermatitis (22.5% vs. 6.7%). This increase is only statistically significant for dyspnea, rhinitis, conjunctivitis and dermatitis. Changes in lung function parametres were much more frequent among the workers at the two factories than among the non-exposed workers (40.8% vs. 11.7%). Tobacco also seemed to have an effect on respiratory deficit. Analysis of the chest radiographs of the exposed subjects, using the ILO international classification, revealed 19 (15.8%) abnormal films. CONCLUSIONS: Working conditions in cement factories must be improved rapidly (particularly collective technical prevention) and a medical service should be set up for regular management and follow-up of the workers.

Adult↗
PubMed2001

[Respiratory risk in carpenters and cabinet makers].

They are many risks relating to the wood; they are caused by natural components of wood, products of conservation, chemical agents and parasites of wood. We have carried out a retrospective survey which concerned exposed workers and controls in twenty small handicraft workshops in the joiners' souk of Marrakesh, it has enabled us to evaluate the prevalence of the clinical symptoms and disorders of respiratory function in 242 exposed subjects to the wood dust and 121 controls. This enquiry consisted of a questionnaire (European Coal and Steel Community: ECSC and the World Health Organisation: WHO), a clinical examination and a spirometry. Sixty-one point nine % of those exposed had clinical respiratory symptoms versus only 21.5% of controls. Rhinitis, asthma, conjunctivitis, chronic bronchitis and dermATitis were significantly more frequent in those exposed than among the non-exposed, with respectively 55.8%, 14.5%, 24.8%, 21.1% and 12.8% versus 16.5%, 6.6%, 8.3%, 5.8% and 4.9%. Exposure was the cause of respiratory symptoms because among non-smokers, exposed workers were more symptomatic than controls. Smoking exhibited a potentializing effect on airborne occupational contaminants because among exposed workers disorders were 1.8 times more frequent in smokers than non-smokers. A variable degree of respiratory obstruction was found among 30.1% of the exposed individuals versus 12.4% of the unexposed subjects. The effect of exposure was certain because among the non-smokers, 15% of exposed subjects had altered respiratory function versus 4% of unexposed persons. It is imperative to implement an occupational health service and to develop means for collective and individual prevention to maximally reduce the risk.

Adult↗
PubMed1999

'Airborne' contact dermatitis due to Leica immersion oil.

BACKGROUND: Contact dermatitis has often been described in healthcare staff, resulting essentially from the use of natural rubber latex gloves, antiseptics, and especially aldehydes. This study reports an unusual cause of contact dermatitis in laboratory technicians. MATERIALS AND METHODS: Four patients working in the bacteriology departments of three different hospitals were seen for airborne contact dermatitis. All were patch tested for specific plastics and glues. RESULTS: For all patients, positive patch reactions were obtained with classic epoxy resins, such as diglycidylether of bisphenol, as well as with new types, such as diglycidylether of bisphenol F and an epoxyacrylate resin. CONCLUSIONS: Although phenols and ether handled by the laboratory technicians and an epoxy mastic applied during floor repair were initially suspected, an immersion oil used in light microscopy proved to be the real cause of the dermatitis. To our knowledge, these are the first reported cases due to this type of contact.

Air Pollutants, Occupational↗
PubMed1995

[Maintenance therapy: an indispensible complement to periodontal treatment and the surgical implant].

The authors analyze the literature of recent years on maintenance therapy both in parodontopathic patients and in subjects undergoing surgical implantation therapy. We divide the work in two parts; the first shows the general aspects of maintenance therapy, the second shows the specific aspects of maintenance therapy in non surgical parodontal treatment, in after surgical parodontal treatment and after implantation treatment.

Combined Modality Therapy↗
PubMed1994

Results of permanent dual-chamber pacing in symptomatic nonobstructive hypertrophic cardiomyopathy.

Because dual-chamber (DDD) pacing has been shown to be of benefit regarding symptoms, rest and pacing hemodynamics, and exercise duration in patients with obstructive hypertrophic cardiomyopathy (HC), the effect of DDD pacing was assessed in patients with nonobstructive HC who were significantly symptomatic despite medical management. Echocardiography, treadmill exercise testing, thallium-201 scintigraphy, radionuclide angiography, and invasive measurement of rest and semi-erect bicycle exercise hemodynamics were performed in 12 patients before and approximately 4 months after permanent DDD pacing. One patient died 3 months after pacemaker implantation, because of worsening diastolic heart failure. Of the remaining 11 patients, 10 improved regarding symptoms, and treadmill exercise duration was longer during DDD pacing than during the baseline study in sinus rhythm (6.8 +/- 2.8 to 8.5 +/- 2.8 minutes; p < 0.01), with a significant increase in the peak double product achieved (28.9 +/- 6.1 to 31.0 +/- 6.8 x 10(3); p < 0.05). However, there were significant reductions in cardiac (3.7 +/- 0.9 to 3.1 +/- 0.5 ml/min/m2; p < 0.01) and stroke volume (47.4 +/- 11.4 to 38.7 +/- 6.5 ml/beat/m2; p < 0.01) indexes, and a trend toward reduction in submaximal stroke volume index during DDD pacing as compared with the baseline study in sinus rhythm (44.7 +/- 13.5 to 40.9 +/- 10.9 ml/beat/m2; p = 0.097). No change in peak heart rate, cardiac or stroke volume index, mean blood pressure, or pulmonary artery or pulmonary capillary wedge pressure occurred with peak exercise during DDD pacing as compared with the initial exercise study in sinus rhythm.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Radiofrequency catheter atrioventricular node ablation in patients with permanent cardiac pacing systems.

Following successful RF ablation of the atrioventricular node (AVN), temporary pacing is necessary prior to insertion of a permanent pacemaker. The risks and inconvenience of temporary pacing could be avoided if a permanent pacemaker is already in place. This study reports the feasibility of RF ablation of the AVN in 27 patients (age 55 +/- 17 years, 15 males) with hypertrophic cardiomyopathy and pacemakers. Indications for AVN ablation were drug refractory atrial fibrillation in 24 patients, and rapid AVN conduction preventing septal pre-excitation by DDD pacemaker, inserted for relief of left ventricular outflow obstruction, in three cases. Sixteen patients had DDD devices and 11 patients had VVI devices. During RF ablation, each pacemaker was programmed to VVI at 50 beats/min. The ablation catheter was manipulated with fluoroscopic control to avoid close contact with or disturbance of the pacing leads. In 16 patients, RF ablation was performed immediately following pacemaker implantation but in the remaining patients, the AVN was ablated 6-32 months after pacemaker implantation. The power applied was 25-50 watts for a duration of 15-60 seconds. AV block was achieved in all cases but required 34 +/- 36 applications for 16.5 +/- 17.8 min/case. RF ablation consistently caused reversion to magnet rate in one patient and temporarily inhibited appropriate pacemaker discharge in another. However, no other pacemaker or lead malfunction was detected so that temporary pacing was not required in any case. At 6 +/- 3 months follow-up, all pacemakers were functioning normally without alteration in pacing parameters from baseline.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Long-term results of dual-chamber (DDD) pacing in obstructive hypertrophic cardiomyopathy. Evidence for progressive symptomatic and hemodynamic improvement and reduction of left ventricular hypertrophy.

BACKGROUND: We previously reported that 6 to 12 weeks of dual-chamber (DDD) pacing results in clinical and hemodynamic improvement in obstructive hypertrophic cardiomyopathy (HCM). This study examines the long-term results of DDD pacing in obstructive HCM. METHODS AND RESULTS: DDD devices were implanted in 84 patients (mean age, 49 +/- 16 years) with obstructive HCM and severe drug-refractory symptoms. At a mean follow-up of 2.3 +/- 0.8 years (maximum, 3.5 years), the New York Heart Association (NYHA) functional class had improved significantly (1.6 +/- 0.6 versus 3.2 +/- 0.5, P < .00001). Symptoms were eliminated in 28 patients (33%), improved in 47 patients (56%), but remained unchanged in 7 patients (8%). Two patients died suddenly (97% cumulative 3-year survival rate). In 74 patients with significant left ventricular outflow tract (LVOT) obstruction at rest, the LVOT gradients were significantly reduced at follow-up (27 +/- 31 versus 96 +/- 41 mm Hg, P < .00001). Symptoms and provokable LVOT gradients were also reduced in all 10 patients without significant resting but with provokable LVOT obstruction. Persistence of the LVOT obstruction and symptoms was attributed to inability to pre-excite the interventricular septum (n = 8) and onset of atrial fibrillation (n = 7). Fifty patients had two cardiac catheterization evaluations, 3 +/- 1 and 16 +/- 4 months after implantation of a pacemaker. In this subgroup, the NYHA functional class improved from 3.2 +/- 0.5 at baseline to 1.8 +/- 0.7 at the initial evaluation (P < .00001), but with a further significant improvement at the second evaluation: 1.4 +/- 0.6, P < .001. This symptomatic improvement was associated with progressive reduction of LVOT gradient at the two evaluations: baseline, 100 +/- 47 mm Hg; first evaluation, 41 +/- 36 mm Hg (P < .0001); and second evaluation, 29 +/- 34 mm Hg (P < .01). Despite the presence of left bundle branch block, DDD pacing reduced LVOT obstruction significantly in 15 patients (LVOT gradient, baseline 89 +/- 36 mm Hg versus 18 +/- 26 mm Hg at follow-up, P < .0001). There was a weak but significant correlation between the reduction in LVOT gradients accomplished by AV pacing before implantation of DDD device and the eventual reduction in LVOT gradients recorded at the follow-up evaluation (r = .38, P = .0017). Echocardiography demonstrated significant thinning of the anterior septum and distal anterior LV wall in the absence of deterioration of LV systolic function. CONCLUSIONS: (1) Although most of the improvement of symptoms and hemodynamic indexes occurs during the first few months of DDD pacing, further changes are often observed a year later; (2) DDD pacing is associated with an excellent prognosis in a subgroup of severely disabled patients, many of whom present with syncope or presyncope; (3) baseline pacing studies are not essential to identify patients who may benefit from pacing; (4) preexisting left bundle branch block is compatible with severe LVOT obstruction, and DDD pacing is also beneficial in this subgroup; (5) DDD pacing reduces both resting and provokable LVOT obstruction; (6) additional therapy, for example, radiofrequency ablation of the AV node, may be necessary in some patients either to preexcite the interventricular septum or to control atrial fibrillation; and (7) although LV hypertrophy has been considered a primary feature of HCM, pacing appears to reverse LV wall thickness in a significant subset of adult HCM patients.

Adolescent↗
PubMed1992

Molecular requirements of endotoxin (ET) actions: changes in the immune adjuvant, TNF liberating and toxic properties of endotoxin during alkaline hydrolysis.

The effect of alkaline pH and alkaline hydrolysis on the physico-chemical and biological properties of endotoxin (ET) isolated from Serratia marcescens ATCC 13477 by the Biovin procedure was studied. Major emphasis was put on the ion exchange column chromatography and immune adjuvant activity (ADA) of the alkali treated samples. To measure changes in some endotoxicity parameters, Limulus lysate clotting (LAL), chick embryo lethality, Shwartzman skin reactivity and in vitro TNF release were measured. The toxic properties of ET, with the unique exception of the Shwartzman skin reactivity, rapidly diminished during alkaline treatment. As immunogen CBre3, a recombinant HIV glycoprotein which spans the C terminus of gp 120 and the N terminus of gp 41, was used in CD-1 mice, alkali treated and immediately neutralized ET samples (zero time) were inactive as adjuvants, in some cases immunosuppression could be clearly seen. But if the alkaline hydrolysis was continued for 6 h, the ADA became higher than it had been for the starting ET sample. Further alkaline hydrolysis eliminated the ADA of the samples. Both NaOH and propylamine acted similarly on the ET preparation. Reaction kinetic studies of the NaOH detoxification indicated the cleavage of ester bound acyl groups with low binding energy. Chemical analyses of the samples revealed that changes occurred in the fatty acid composition, characterized by a loss of approximately half of the 3-OH myristic acid content.

Adjuvants, Immunologic↗