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R Lehtinen

Publications and source records attributed to R Lehtinen.

At least 19 recordsLinked to original sources
PubMed2000

The effect of PUVA on langerhans cells in rat oral epithelium photosensitized with systemic methoxsalen or topical trioxsalen.

BACKGROUND/PURPOSE: Ultraviolet-A radiation (UVA) of the oral mucosa after photosensitization with either systemic methoxsalen (8-MOP) or topical trioxsalen (TMP), i.e. mouth-PUVA, has been reported to be successful in the treatment of oral lichenoid lesions. In the case of PUVA treatment of skin disorders, local immune suppressive effects have been demonstrated, and the antigen presenting epithelial Langerhans cells (LCs) have been shown to be especially sensitive to ultraviolet treatments. Our aim was to compare the photobiological effects of PUVA in oral mucous membrane (OMM) using topical TMP or systemic 8-MOP photosensitization. METHODS: Rat OMM photosensitized with topical TMP or systemic 8-MOP was treated with PUVA using UVA doses of 1-8 J/cm2. The LCs were demonstrated in epithelial sheets of the treated OMM with ATPase staining. RESULTS: Both treatments caused a sim ilar, dose-dependent depletion of ATPase-positive LCs, with a maximal depletion of 80% or 73% with 8 J/cm2 at 2 days after irradiation as photosensitized with TMP or 8-MOP, respectively. This contrasts with earlier published findings in human skin, where topical TMP is an order of magnitude greater a sensitizer than 8-MOP, and PUVA-induced depletion of LCs occurs maximally 5 days after irradiation. CONCLUSION: The depletion of LCs of rat OMM after PUVA treatment is greater using topical TMP compared to systemic 8-MOP, but the difference is significantly smaller than reported earlier in human skin.

Administration, Oral↗
PubMed1999

Detection of coronary artery disease using maximum value of ST/HR hysteresis over different number of leads.

We have studied the effect of the number and ordering of exercise electrocardiographic (ECG) leads when using the maximum value of the ST segment depression/heart rate (ST/HR) hysteresis over a different number of leads for the detection of coronary artery disease (CAD). The study population consisted of 127 patients with CAD and 220 patients with a low likelihood of the disease referred for an exercise test at Tampere University Hospital, Finland. The lead system used was the Mason-Likar modification of the standard 12-lead system, and exercise tests were performed on a bicycle ergometer. The number of leads was studied using lead sets consisting of first 2 leads, then 3 leads, and so on, up to all 12 leads. The criterion for the order of inclusion of the next lead in the new lead set was based on the maximized area under the receiver operating characteristic (ROC) curve for the new lead set. The importance of the number of leads was evaluated by means of three different approaches: ROC analysis; using a fixed partition criterion of 0.01 mV; and using a fixed specificity value of 80%. According to the results, the most powerful diagnostic capacity of an individual lead was in lead V5, and the most deficient diagnostic capacities were in leads aVL and V1. Using the maximum search procedure, it was possible to improve the diagnostic capacity of the ST/HR hysteresis by anything from 4 up to a maximum of 8 leads. After that it started to decrease rapidly. In conclusion, this study suggests that the diagnostic capacity of the ST/HR hysteresis could be improved by increasing the number of leads. However, the selection of leads is of major importance when using the maximum value of the ST/HR hysteresis over the leads in the detection of CAD.

Adult↗
PubMed1999

ST/HR hysteresis: exercise and recovery phase ST depression/heart rate analysis of the exercise ECG.

ST segment depression/heart rate (ST/HR) hysteresis is a recently introduced novel computer method for integrating the exercise and recovery phase ST/HR analysis for improved detection of coronary artery disease (CAD). It is a continuous diagnostic variable that extracts the prevailing direction and average magnitude of the hysteresis in ST depression against HR during the first 3 consecutive minutes of postexercise recovery. This article reviews the development and evaluation of this new method in a clinical population of 347 patients referred for a routine bicycle exercise electrocardiographic (ECG) test at Tampere University Hospital, Finland. Of these patients, 127 had angiographically proven CAD, whereas 13 had no CAD according to angiography, 18 had no perfusion defect according to Tc-99m-sestamibi myocardial imaging and single photon emission computed tomography, and 189 were clinically normal with respect to cardiac diseases. For each patient, the values for ST/HR hysteresis, ST/HR index, end-exercise ST depression, and recovery ST depression were determined for each lead of the Mason-Likar modification of the standard 12-lead exercise ECG and maximum value from the lead system (aVL, aVR, and V1 excluded). The area under the receiver operating characteristics curve (ie, the discriminative capacity) of the ST/HR hysteresis was 89%, which was significantly larger than that of the end-exercise ST depression (76%, P < .0001), recovery ST depression (84%, P = .0063) or ST/HR index (83%, P = .0023), indicating the best diagnostic performance of the ST/HR hysteresis in detection of CAD regardless of the partition value selection. Furthermore, the superior diagnostic performance of the method was relatively insensitive to the ST segment measurement point or to the ECG lead selection. These results suggest that the ST/HR hysteresis improves the clinical utility of the exercise ECG test in detection of CAD.

Adult↗
PubMed1998

Correct utilization of exercise electrocardiographic leads in differentiation of men with coronary artery disease from patients with a low likelihood of coronary artery disease using peak exercise ST-segment depression.

In this study we compared the diagnostic characteristics of the individual exercise electrocardiographic leads, 3 different lead sets comprising standard leads and the effect of the partition value in the detection of coronary artery disease (CAD). The diagnostic variable used was ST-segment depression at peak exercise, and the study population consisted of 101 patients with CAD and 100 patients with a low likelihood of the disease. The lead system used was the Mason-Likar modification of the standard 12-lead system and exercise tests were performed on a bicycle ergometer. The comparisons were performed by means of receiver-operating characteristic analysis and by determining sensitivities at a fixed 95% specificity. These properties, defined here as diagnostic capacity, were the most efficacious in leads I, -aVR, V4, V5, and V6. Diagnostic capacities in leads aVL, aVF, III, V1, and V2 were quite poor; statistical comparisons indicated significant differences between these leads and lead V5 (p < or = 0.0001 in each case). Use of the maximum value of ST-segment depression at peak exercise derived from all 12 leads produced a considerable decrease in the diagnostic capacity of the exercise electrocardiogram compared with lead V5. The exclusion of leads aVL, V1, and III improved the diagnostic capacity compared with the 12-lead set, but it was still smaller than that of lead V5. With use of a lead set with the 5 best leads increased the diagnostic capacity over other lead sets and over any individual lead. Further improvement was noted when a 50% smaller partition value was applied to leads I and -aVR than for the other leads (p = 0.041). In conclusion, this study suggests that use of leads I, -aVR, V4, V5, and V6 is the most influential when differentiating between patients with CAD and patients with a low likelihood of disease using peak exercise ST-segment depression. The effective use of leads I and -aVR requires the partition value applied for these leads to be 50% smaller than that used for the lateral precordial leads.

Coronary Disease↗
PubMed1997

Effect of ST segment measurement point on performance of exercise ECG analysis.

To evaluate the effect of ST-segment measurement point on diagnostic performance of the ST-segment/heart rate (ST/HR) hysteresis, the ST/HR index, and the end-exercise ST-segment depression in the detection of coronary artery disease, we analysed the exercise electrocardiograms of 347 patients using ST-segment depression measured at 0, 20, 40, 60 and 80 ms after the J-point. Of these patients, 127 had and 13 had no significant coronary artery disease according to angiography, 18 had no myocardial perfusion defect according to technetium-99m sestamibi single-photon emission computed tomography, and 189 were clinically 'normal' having low likelihood of coronary artery disease. Comparison of areas under the receiver operating characteristic curves showed that the discriminative capacity of the above diagnostic variables improved systematically up to the ST-segment measurement point of 60 ms after the J-point. As compared to analysis at the J-point (0 ms), the areas based on the 60-ms point were 89 vs. 84% (p=0.0001) for the ST/HR hysteresis, 83 vs. 76% (p<0.0001) for the ST/HR index, and 76 vs. 61% (p<0.0001) for the end-exercise ST depression. These findings suggest that the ST-segment measurement at 60 ms after the J-point is the most reasonable point of choice in terms of discriminative capacity of both the simple and the heart rate-adjusted indices of ST depression. Moreover, the ST/HR hysteresis had the best discriminative capacity independently of the ST-segment measurement point, the observation thus giving further support to clinical utility of this new method in the detection of coronary artery disease.

Coronary Disease↗
PubMed1997

Reproducibility of the ST-segment depression/heart rate analysis of the exercise electrocardiographic test in asymptomatic middle-aged population.

The reproducibility of the ST-segment depression against heart rate (ST/HR) hysteresis, ST/HR index, and end-exercise ST depression between the repeated exercise electrocardiographic tests were determined in 61 asymptomatic middle-aged subjects. The findings support the clinical utility of the ST/HR hysteresis, but it is noteworthy that the results also suggest that the magnitude of change in the exercise electrocardiographic variables, which has to be observed to make the clinician confident that a real diagnostic change has occurred, is surprisingly large.

Electrocardiography↗
PubMed1997

The effect of lead selection on traditional and heart rate-adjusted ST segment analysis in the detection of coronary artery disease during exercise testing.

Several methods of heart rate-adjusted ST segment (ST/HR) analysis have been suggested to improve the diagnostic accuracy of exercise electrocardiography in the identification of coronary artery disease compared with traditional ST segment analysis. However, no comprehensive comparison of these methods on a lead-by-lead basis in all 12 electrocardiographic leads has been reported. This article compares the diagnostic performances of ST/HR hysteresis, ST/HR index, ST segment depression 3 minutes after recovery from exercise, and ST segment depression at peak exercise in a study population of 128 patients with angiographically proved coronary artery disease and 189 patients with a low likelihood of the disease. The methods were determined in each lead of the Mason-Likar modification of the standard 12-lead exercise electrocardiogram for each patient. The ST/HR hysteresis, ST/HR index, ST segment depression 3 minutes after recovery from exercise, and ST segment depression at peak exercise achieved more than 85% area under the receiver-operating characteristic curve in nine, none, three, and one of the 12 standard leads, respectively. The diagnostic performance of ST/HR hysteresis was significantly superior in each lead, with the exception of leads a VL and V1. Examination of individual leads in each study method revealed the high diagnostic performance of leads I and -aVR, indicating that the importance of these leads has been undervalued. In conclusion, the results indicate that when traditional ST segment analysis is used for the detection of coronary artery disease, more attention should be paid to the leads chosen for analysis, and lead-specific cut points should be applied. On the other hand, ST/HR hysteresis, which integrates the ST/HR depression of the exercise and recovery phases, seems to be relatively insensitive to the lead selection and significantly increases the diagnostic performance of exercise electrocardiography in the detection of coronary artery disease.

Coronary Disease↗
PubMed1997

Computer model analysis of the relationship of ST-segment and ST-segment/heart rate slope response to the constituents of the ischemic injury source.

The objective of the study was to investigate a proposed linear relationship between the extent of myocardial ischemic injury and the ST-segment/heart rate (ST/HR) slope by computer simulation of the injury sources arising in exercise electrocardiographic (ECG) tests. The extent and location of the ischemic injury were simulated for both single- and multivessel coronary artery disease by use of an accurate source-volume conductor model which assumes a linear relationship between heart rate and extent of ischemia. The results indicated that in some cases the ST/HR slope in leads II, aVF, and especially V5 may be related to the extent of ischemia. However, the simulations demonstrated that neither the ST-segment deviation nor the ST/HR slope was directly proportional to either the area of the ischemic boundary or the number of vessels occluded. Furthermore, in multivessel coronary artery disease, the temporal and spatial diversity of the generated multiple injury sources distorted the presumed linearity between ST-segment deviation and heart rate. It was concluded that the ST/HR slope and ST-segment deviation of the 12-lead ECG are not able to indicate extent of ischemic injury or number of vessels occluded.

Adult↗
PubMed1997

An open clinical trial of a new mouth-PUVA variant in the treatment of oral lichenoid lesions.

OBJECTIVE: To investigate the feasibility of topical psoralen PUVA (sensitization in photosensitizing psoralen drug + UVA radiation) treatment of oral lichenoid lesions (OLL). STUDY DESIGN: A total of 16 patients with OLL were treated using a 0.01% trioxsalen ointment and UVA doses in the 0.09 to 1.80 J/cm2 range. The average number of sessions was 8.7 and a mean cumulative irradiation dose was 4.25 J/cm2. RESULTS: A marked-to-complete healing occurred in 3 to 16 (19%) patients immediately after therapy, in 4 of 14 (29%) after 3 months, and in 5 of 14 (38%) after 14 months, respectively. Of the 16 subjects with OLL, five were diagnosed as oral lichen planus (OLP) and 11 were classified as oral lichenoid reaction (OLR). Post-PUVA amelioration rate in patients with genuine OLP (4 of 5, 80%) was superior to that in patients with OLR (1 of 9, 11%). CONCLUSION: Topical trioxsalen photosensitization can be used in mouth-PUVA treatment, and lichen planus is a main indication for this therapy.

Administration, Topical↗
PubMed1996

Accurate detection of coronary artery disease by integrated analysis of the ST-segment depression/heart rate patterns during the exercise and recovery phases of the exercise electrocardiography test.

In this comparative cross-sectional study, we evaluated whether a novel computerized diagnostic variable, ST-segment depression/heart rate ST/HR analysis during both the exercise and postexercise recovery phases of the exercise electrocardiography (ECG) test, can detect coronary artery disease more accurately than methods using either exercise or recovery phase alone. The study population comprised 347 clinical patients referred for a routine bicycle exercise ECG test at Tampere University Hospital, Finland. Of these, 127 had angiographically proven coronary artery disease, whereas 13 had no coronary artery disease according to angiography, 18 had no perfusion defect according to technetium-99m sestamibi single-photon emission computed tomography, and 189 were clinically normal with respect to cardiac diseases. For each patient, the maximum values of the ST/HR hysteresis, ST/HR index, end-exercise ST depression, and recovery ST depression were determined from the Mason-Likar modification of the standard 12-lead exercise electrocardiogram [aVL, aVR, and V1 excluded]. The diagnostic performance of these continuous diagnostic variables was compared by means of receiver-operating characteristic analysis. The area under the receiver-operating characteristic curve of the ST/HR hysteresis was 89%, which was significantly larger than that of the end-exercise ST depression (76%, p < or = 0.0001), recovery ST depression (84%, p = 0.0063), or ST/HR index (83%, p = 0.0023), indicating superior diagnostic performance of the ST/HR hysteresis independent of the partition value selection. In conclusion, computerized analysis of the HR-adjusted ST depression pattern during the exercise phase, integrated with the HR-adjusted ST depression pattern during the recovery phase after exercise, can significantly improve the diagnostic performance and clinical utility of the exercise ECG test for the detection of coronary artery disease.

Adult↗
PubMed1996

A computer program for comprehensive ST-segment depression/heart rate analysis of the exercise ECG test.

The ST-segment depression/heart rate (ST/HR) analysis has been found to improve the diagnostic accuracy of the exercise ECG test in detecting myocardial ischemia. Recently, three different continuous diagnostic variables based on the ST/HR analysis have been introduced; the ST/HR slope, the ST/HR index and the ST/HR hysteresis. The latter utilises both the exercise and recovery phases of the exercise ECG test, whereas the two former are based on the exercise phase only. This present article presents a computer program which not only calculates the above three diagnostic variables but also plots the full diagrams of ST-segment depression against heart rate during both exercise and recovery phases for each ECG lead from given ST/HR data. The program can be used in the exercise ECG diagnosis of daily clinical practice provided that the ST/HR data from the ECG measurement system can be linked to the program. At present, the main purpose of the program is to provide clinical and medical researchers with a practical tool for comprehensive clinical evaluation and development of the ST/HR analysis.

Exercise Test↗
PubMed1996

The mental nerve blink reflex in the diagnosis of lesions of the inferior alveolar nerve following orthognathic surgery of the mandible.

The purpose of this study was to evaluate the diagnostic value of a new modification of the blink reflex test with stimulation of the distribution of the mental nerve in iatrogenic lesions of the inferior alveolar nerve. The test was performed on 23 patients undergoing orthognathic surgery of the mandible, most of them (20) with bilateral sagittal split osteotomies. The function of the inferior alveolar nerve was studied preoperatively, and 2 weeks, 2 months, 6 months and 1 year postoperatively with both mental nerve blink reflex test and clinical neurosensory testing. The objective electrophysiological test proved to be useful in the diagnosis and follow-up of sensory impairment of the inferior alveolar nerve. The results of the mental nerve blink reflex test and clinical neurosensory testing were closely related. The results of the two tests did not differ statistically significantly in the two first postoperative examinations. The positive predictive value of the mental nerve blink reflex test was better than that of clinical neurosensory testing: an initially abnormal reflex response predicted persistent subjective sensory symptoms after one year more reliably than did altered sensation at the first two examinations. Irrespective of the possible coexistent sensory symptoms and signs, a normal mental nerve blink reflex within 2 months after operation also predicted a reasonably good sensory recovery at 1 year.

Adolescent↗
PubMed1994

Performance characteristics of various exercise ECG classifiers in different clinical populations.

To improve the diagnostic power of the exercise electrocardiographic test in detecting myocardial ischemia, the authors have recently developed a diagnostic method called multivariate ST-segment/heart rate (ST/HR) analysis (MUSTA). The goal of this study was to evaluate the validity of MUSTA in different clinical populations and to compare its performance characteristics with ST-segment depression, the ST/HR slope, and the delta ST/HR index in these populations. The computerized exercise electrocardiographic measurements were performed on 1,507 cases, and 382 patients were selected as the study population: 161 with significant coronary artery disease according to coronary angiography and 221 with a low likelihood of coronary artery disease. The diagnostic accuracy of MUSTA in the pooled population was 77.7% (297 out of 382 patients), which was clearly better than the accuracy of 69.6% (266 out of 382 patients) using the conventional ST-segment depression criterion of 0.10 mV in detecting coronary artery disease and exercise-induced myocardial ischemia. According to receiver operating characteristics analysis, MUSTA had significantly better diagnostic power than the other classifiers. These findings suggest that multivariate and compartmental analysis methods like MUSTA can further improve the clinical importance of the exercise electrocardiogram.

Coronary Angiography↗
PubMed1993

Articaine and lidocaine for maxillary infiltration anesthesia.

This study was undertaken to compare the anesthetic properties of articaine hydrochloride with 1:200,000 epinephrine (Ultracain DS) and lidocaine with 1:80,000 epinephrine (Xylocain-Adrenalin) for maxillary infiltration anesthesia. Twenty healthy dental student volunteers were included in this double-blind study. Each subject received 0.6 mL of each test solution at different times. Infiltration anesthesia was performed on the upper lateral incisor. The onset and duration of anesthesia were monitored using an electric pulp tester. No statistically significant differences were seen in the onset and duration of anesthesia between the articaine and lidocaine solutions.

Adult↗
PubMed1993

Function of masticatory system after surgical-orthodontic correction of maxillomandibular discrepancies.

Thirty-two subjects were interviewed about their pre- and post-treatment symptoms of craniomandibular disorders (CMD) and examined for signs of CMD at follow up 2-5 years after surgical-orthodontic treatment for maxillomandibular discrepancies. Symptoms of CMD were among the main reasons for seeking treatment in 31% of the patients. Patients with retrognathic mandibles had significantly more severe symptoms than patients with mandibular prognathism before treatment. After treatment, the severity of subjective symptoms had decreased for the patients as a whole, and significantly in the subjects with originally severe symptoms. Ten subjects out of 12 reported a decrease in the occurrence of headache. The clinical findings of CMD after surgery were usually mild. The importance of occlusal adjustment and rehabilitation as final steps after surgical-orthodontic treatment is stressed.

Adolescent↗
PubMed1992

Successful pain management by Finnish oral surgeons. A clinical follow-up study.

The current practice of postoperative pain management among Finnish oral surgeons was evaluated in a two-phase study. In the first phase, a questionnaire was sent to specialist members of the Finnish Society of Oral and Maxillofacial Surgeons that concerned the routine use of analgesic drugs after surgical removal of third molar teeth. In the second phase, the clinical adequacy of pain medication was assessed in 84 patients who had the same procedure. Patients estimated the intensity of pain with a 100 mm visual analogue scale at five time points during the day of surgery and on three postoperative days. Anti-inflammatory analgesics were widely used either alone or in combination with centrally acting analgesic drugs. Tolfenamic acid, diclofenac, and ketoprofen were the most commonly used analgesic drugs. The analgesic effect of the currently used drug combinations proved to be sufficient except in a few patients during the first night after surgery.

Adult↗
PubMed1991

Penetration of erythromycin into periapical lesions after repeated doses of erythromycin acistrate and erythromycin stearate: a pilot study.

In 26 patients who had undergone apicectomy and extirpation of granulomas (n = 9) or radicular cysts (n = 17), concentrations of erythromycin, 2'-acetyl erythromycin, and their anhydro forms were determined with a novel chemical method in plasma and periapical lesions after at least 2 days of treatment with erythromycin acistrate (EA) (400 mg three times daily, n = 11) or erythromycin stearate (ES) (500 mg three times daily, n = 15). Oral surgery was performed 2 1/2 to 3 hours after the last dose. Blood samples were collected at the time of operation, and immediately before antibiotic treatment, and 1, 2, and 6 hours after treatment. At all time points EA produced at least twice the total antibiotic (2'-acetyl erythromycin plus erythromycin) concentrations in plasma as ES. Erythromycin levels in plasma were at least as high after EA treatment as after ES. In periapical lesions erythromycin concentration after EA was three times higher (1.34 +/- 0.28 micrograms/gm) than after ES treatment (0.40 +/- 0.17 micrograms/gm). Although the total drug concentration in periapical lesions was about the same after EA (2.64 micrograms/ml) and ES (3.41 micrograms/ml), most of the drug recovered after ES was antimicrobially inactive anhydroerythromycin (3.01 micrograms/gm). The concentration of anhydroerythromycin in plasma was approximately the same as that of erythromycin after ES throughout the dose interval. After EA treatment both plasma and the periapical lesion samples contained hardly detectable amounts of anhydroerythromycin. Hence EA has a good bioavailability essential for treatment and prophylaxis of bacterial infections in dentistry.

Adult↗