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Biomedical subjects

C Katsaros

Publications and source records attributed to C Katsaros.

32 records · Page 2Linked to original sources
PubMed1998

Chronic sympathetic suppression in the treatment of chronic congestive heart failure.

Previous short-term studies demonstrated that treatment with clonidine produced significant hemodynamic improvement in patients with congestive heart failure (CHF). In this study we followed 12 CHF patients (10 M, 2 F age 63+/-11, 10 with ischemic cardiomyopathy and 2 with dilated cardiomyopathy) treated with 0.15 or 0.075 mg oral clonidine twice daily for 13+/-5 months (range 6-23). with functional evaluation at baseline, 6 weeks and 6 months. There was suppression of circulating catecholamines, associated with significant ameliorations in NYHA class, in duration of exercise tolerance (from 246+/-68 sec to 362+/-30 and 459+/-70 sec, respectively p < 0.02), in ejection fraction (from 32+/-7% to 35+/-5 and 39+/-7% p < 0.04) and in left ventricular enlargement as assessed echocardiographically. There were also improvements in a number of electrophysiologic parameters calculated by computerized analysis of ambulatory ECG tapes, such as heart rate variability, indicating diminished propensity to malignant arrhythmias, as confirmed by decreases in the numbers of isolated premature ventricular contractions, couplets and episodes of non-sustained ventricular tachycardia. The data suggest that chronic central sympathetic suppression with clonidine in CHF results in significant functional amelioration and improved electrophysiologic stability.

Administration, Oral↗
PubMed1997

Replantation of an inverted lower second premolar germ.

During the initial X-ray control of a 10-year-old female orthodontic patient, a late development and an inverted position of the lower left second premolar was seen. 4.3 years later the tooth with its follicle was replanted in the upright position, preserving the second deciduous molar; at that time the root development was at an early stage. At a follow-up control 4 years after the surgical procedure the replanted tooth had erupted and the sensibility response was normal. Its root, however, although completed, could not reach the length and especially the width (in the apical half) of the contralateral premolar. This relative reduction in width seems to follow a temporary thickening of that part of the root formed during the first period after replantation. The anamnestic data suggest that physiologic exfoliation of the deciduous molar took place.

Bicuspid↗
PubMed1996

Profile changes following extraction vs. nonextraction orthodontic treatment in a pair of identical twins.

A pair of 11.5-year-old monozygotic twin boys--with a class I occlusion, deep bite and crowding in the lower arch--was presented for orthodontic treatment. One of them was treated in combination with extraction of 4 premolars while in the other the treatment was carried out without extractions. The superimposition of the pretreatment cephalometric tracings on the N-Pog line displayed minimal differences in the sagittal position of the incisors and no differences in the soft tissue profile. As a result of protrusion of the incisors in the nonextraction case and retrusion in the extraction case, a sagittal difference of 7.0 mm for the incision superius and 5.5 mm for the incision inferius was registered between the twins in relation to the N-Pog line at the end of treatment. However, the corresponding soft tissue differences were only 2.0 mm for the labrale superius and 3.2 mm for the labrale inferius and seemed to be reduced 1 year later.

Bicuspid↗
PubMed1996

The influence of extraction versus non-extraction orthodontic treatment on the soft tissue profile.

The aim of the present study was to study profile changes following orthodontic harmonization of enlarged overjet and to attempt to trace predictive aspects regarding prognosis of the soft tissue changes. Lateral cephalograms and study models of 40 female patients, at least 12 years old at the start of treatment, with an overjet of > or = 6 mm were analyzed before (T1) and after treatment (T2). Twenty patients were treated without extractions, while in the remaining 20 patients extractions of premolars were carried out bilaterally in both jaws. The 2 groups were found to be highly homogeneous as regards overjet, cephalometric characteristics, space condition in the upper arch at T1 and both at T1 and T2 as regards age. The most striking aspect of the findings was the considerable amount of variability of the soft tissue changes. These changes were found to be rather unpredictable for the individual patient, since the regression models employed could give only a very wide individual prediction range. The relatively small changes registered, using superimposition methods, in both groups as regards the sagittal position of the lips in comparison to the very strong changes observed in relation to the esthetic line shows that the influence of the growth of the chin and/or the nose on the facial profile might be more important than the influence of the orthodontic treatment. The interpretation of the findings in the present study suggests that, apart from marked cases of skeletal convexity or concavity, the extraction versus non-extraction decision should be based primarily upon current knowledge of long-term stability of orthodontic treatment results.

Adolescent↗
PubMed1996

Craniofacial bone remodeling in growing rats fed a low-calcium and vitamin-D-deficient diet and the influence of masticatory muscle function.

Fifty-two male growing rats were randomly divided into three groups. The first group (n = 18) received a hard deficient diet, and the second (n = 18) a soft deficient diet. The control group (n = 16) was fed the normal hard diet. At the beginning and in the middle of the 28-day experimental period oxytetracycline was injected. Two representative coronal sections of the snout and the corresponding contact microradiographs were analyzed. The bone mass of the premaxillary and nasal bones seemed to be less in the two deficient diet groups than in the normal one, due to an increased endosteal bone resorption and decreased bone formation. No difference in the bone apposition rate and pattern could be seen between the deficient hard and soft diet groups, except in the dorsal part of the premaxilla, where the bone formed in the first half of the experiment was markedly more resorbed in the deficient soft diet group during the remaining period than in the deficient hard diet group. The morphology of the sutures was influenced by the altered function, since the sutural space became narrower, and premature obliterations of the internasal suture were observed in the deficient soft diet group. In conclusion, poor bone quality was observed in the skull of rats fed a low-calcium and vitamin-D-deficient diet, with less bone mass than in normal conditions. Masticatory function was a significant factor influencing bone remodeling and sutural growth even in situations in which a metabolic bone disturbance exists.

Animals↗
PubMed1995

[The psychosocial aspects in orthodontically treated and untreated adults with similar, clearly visible tooth malalignments].

A study was undertaken to compare the psychosocial aspects of orthodontic treatment or non-treatment of female adults, 25 of whom underwent treatment and 25 of whom did not, with similar, visible malocclusion. Interviews, for which 52 standardized questions were prepared in collaboration with a graduate psychologist, served as the methodological basis of the study. The results of the study indicate that in relation to the aesthetic aspects of orthodontic treatment, the treated group showed a high degree of sensitivity and self perception. Following orthodontic treatment members of this group exhibited a highly significant improvement in their subjective perception of the aesthetic aspects of their dental and facial appearance. In spite of the differences observed in the 2 groups, it nevertheless remains difficult to draw general conclusions or to recommend guidelines which would cover all cases. When the question is to orthodontically treat or not treat female adults, the answer rests with the individual patient.

Adult↗
PubMed1995

Effect of masticatory muscle fatigue on cranio-vertical head posture and rest position of the mandible.

The aim of this study was to investigate whether induced fatigue of the masticatory muscles had any influence on the head posture, and whether this influence is related to the rest position and the movement characteristics of the mandible. The sample consisted of 13 female individuals, aged 23-34 yr. For the evaluation of possible changes in the natural cranio-vertical head posture, standardized facial profile photographs were used. Photographs were also used for the study of the facial characteristics. The freeway space and the opening and closing velocity of the mandibular displacement, as well as the duration of the masticatory cycles, were monitored with an optoelectronic method. A controlled dynamic fatigue was induced by a specially constructed spring-loaded device placed in the premolar region. No significant changes in the mean cranio-vertical postural position of the head were found during the various recording stages, while the freeway space was found to increase significantly after the fatigue test. No significant differences were observed concerning the average values of the mandibular movement characteristics. The analysis of the association between the individual changes showed an increase in the freeway space after the fatigue test in the subjects which exhibited an increase in the duration of the masticatory cycle in that period. No significant associations could be found between the changes in the head posture and the mandibular movement characteristics. Also, no significant correlation could be found between the facial type of the subjects and the variables studied.

Adult↗
PubMed1994

[The course and results of the orthodontic treatment of 44 consecutively treated Class-II cases].

In this study treatment progress and treatment results of a consecutively treated group of 44 patients displaying a Class II malocclusion were evaluated in their relationship to the treatment goal. 41% of the patients had come to see the orthodontist on the advice of their family dentist but without any subjective problems as regards their tooth position. In 43% of the patients the treatment could not be finished in accordance with the treatment plan. In approximately 2/3 of these cases the reasons for the compromised results were due to patient cooperation problems. In the other 1/3 various types of treatment problems were encountered with loss of anchorage being the most typical. Over the entire treatment period patient cooperation was good in only approximately 50% of the cases. Oral hygiene was good in 27% of the patients at the first consultation appointment, but during the course of treatment this percentage increased to 64%. 85% of the patients expressed satisfaction with treatment results, but 34% of the patients did find the treatment to have been a burden. Enamel decalcifications were noticed in eleven patients. In another eleven patients root resorption of more than 2 mm of at least one upper incisor was noted.

Adolescent↗
PubMed1994

Functional influence on sutural growth. A morphometric study in the anterior facial skeleton of the growing rat.

The aim of this study was to quantify the sutural response in the various parts of the rat's upper frontal viscerocranium and study the possible effects caused by reduced masticatory muscle function. Twenty growing male albino rats were randomly divided into two equal groups: one group (Hard Diet group) received the ordinary diet in a hard pellets form, while the other (Soft Diet group) a soft diet. The experimental period started just before the rats' pubertal growth spurt (28 days old) and its duration was 28 days. After death, the heads of the animals were taken for preparation of undecalcified frontal sections, 100 microns thick. Contact microradiographs of six representative homologous sections, for every animal in both groups, were prepared. The mean width, length, height, and interdigitation ratio of the internasal, naso-premaxillary, and interpremaxillary sutures, as well as the orientation of the bony surfaces of the naso-premaxillary suture were quantified on the contact microradiographs using the IBAS automatic image analysis system. The width of the sutural space was found to be significantly greater in the Hard Diet group than in the Soft Diet group in all the sutures studied (P < 0.01). No differences in the interdigitation of the sutures were found between the two groups, except in the internasal suture in the middle part of the snout, where the Hard Diet group exhibited increased interdigitations. The bony surfaces of the naso-premaxillary suture were significantly more parallelly-orientated in the animals with reduced masticatory muscle function (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1993

Anterior open bite malocclusion: a follow-up study of orthodontic treatment effects.

Treatment response and stability of the anterior open bite malocclusion were evaluated in 20 open bite patients (17 females, 3 males), who were treated with the Edgewise appliance. The overbite, the number of teeth in occlusion, the functional occlusal contacts of the incisors and the cephalometric characteristics were studied before treatment (T1), at the end of retention (T2), and at least 1 year out of retention (T3). The apical root resorption of the upper incisors was analysed before and after treatment. The mean age at the follow-up control was 17 years 10 months. In 15 patients at least two occlusal contacts of the incisors were possible at the end of the retention period as well as at the follow-up control. The number of teeth in occlusion mesial to the second molars, expressed in percentage of the maximum possible, increased from 40 to 70 per cent during treatment with a positive tendency from T2 to T3. Apical root resorption of the upper incisors exceeded 10 per cent of the original root length in 4 out of 19 measurable cases. One of these patients had a history of trauma and the three others displayed atypical root form. Cases with an increased facial convexity, in which the uprighting of the incisors was possible, seemed to have a favourable treatment prognosis.

Adolescent↗
PubMed1992

Electrophysiological and electropharmacological studies in pre-excitation syndromes: results with propafenone therapy and isoproterenol infusion testing.

To study the electrophysiological effects of oral propafenone on accessory pathways and determine the potential for catecholamine-mediated reversal of these effects, comprehensive electrophysiology studies (EPS) were conducted in 11 patients with manifest (n = 9) or concealed (n = 2) pre-excitation syndrome. EPS were performed at baseline (in the drug-free state), after oral propafenone loading, and with isoproterenol infusion during propafenone therapy. The study group included 10 men and 1 woman with a mean age of 39 +/- 13 years, who presented with symptoms of palpitations (n = 6), presyncope (n = 3) and syncope (n = 2). The clinical arrhythmia was atrioventricular reciprocating tachycardia (n = 6), atrial flutter/fibrillation (n = 3), or both (n = 2). During the baseline EPS the accessory pathway location was identified as left (n = 6) or septal (n = 5). The mean anterograde effective refractory period was 265 +/- 42 ms, the shortest pre-excited RR interval 259 +/- 20 ms and the retrograde refractory period 258 +/- 39 ms. Orthodromic atrioventricular reciprocating tachycardia was induced in 10 patients (mean cycle length = 324 +/- 31 ms). Antidromic reciprocating tachycardia was induced in one patient (cycle length = 340 ms). In all the 11 patients EPS were repeated after 4 days of oral propafenone loading (668 +/- 226 mg daily) when drug steady state was expected to have been achieved. One additional patient had baseline EPS but developed clinical arrhythmia recurrences after propafenone loading and thus he was excluded from the study; follow-up EPS were conducted on procainamide.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1992

Effect of successful coronary angioplasty on the signal-averaged electrocardiogram.

The effect of successful coronary artery angioplasty on the signal-averaged electrocardiogram (SAECG) was examined in 50 patients (41 men, 9 women, aged 55 +/- 8 years) with stable (26 patients) or unstable angina (24 patients) and good overall left ventricular function (ejection fraction = 55% +/- 8%). The SAECG was recorded before and within 24-48 hours after the angioplasty and was filtered at 40-250 Hz, with 250 beats averaged. The noise level averaged 0.57 +/- 0.15 microV before and 0.56 +/- 0.17 microV after the procedure. There was no overall significant difference between pre- and postangioplasty SAECGs. Subgroup analysis showed that 14 patients had a significant increase of the root mean square voltage of the last 40 msec of the filtered QRS that was independent of noise level changes, previous myocardial infarction, stable or unstable angina status, positive or negative baseline SAECG, or vessel being dilated. Eleven patients (22%) had late potentials at baseline, of whom four (36%) lost them after angioplasty, while one patient developed them after the procedure, all due to root mean square voltage changes. Thus, successful angioplasty exerted no significant overall effect on the SAECG, suggesting that the substrate of late potentials was not grossly altered by the procedure in our patients. However, there appear to be some patients, constituting approximately one third of this study population, who derive a favorable influence on the SAECG from angioplasty, a subgroup that needs to be further defined in future studies.

Angina Pectoris↗
PubMedDate not supplied

Caries-inhibiting effect of preventive measures during orthodontic treatment with fixed appliances. A systematic review.

A systematic review was performed of published data on the caries-inhibiting effect of preventive measures during orthodontic treatment with fixed appliances. The purpose was to develop evidence-based recommendations about the most effective means of preventing white spot lesions in orthodontic patients. The 15 studies included were divided into four groups based on comparable preventive measures: fluoride, chlorhexidine, sealants and bonding materials. The caries-inhibiting effect of the preventive measures was expressed by the prevented fraction (PF). The overall PF of the fluoride-releasing bonding materials was 20% (SEM 0.09). This effect was, however, not statistically significant. It was impossible to calculate an overall PF for the other preventive measures, but the tendency of their caries-inhibiting effect has been described. The use of toothpaste and gel with a high fluoride concentration of 1,500-5,000 ppm or of complementary chlorhexidine during orthodontic treatment showed a demineralisation-inhibiting tendency. The use of a polymeric tooth coating on the tooth surface around the brackets showed almost no demineralisation-inhibiting effect. Many publications had to be excluded from this systematic review because of improper research designs. Future clinical trials are needed to give evidence- based advice on the optimal caries-prevention strategy.

Cariostatic Agents↗