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Biomedical subjects

R Holle

Publications and source records attributed to R Holle.

At least 37 records · Page 2Linked to original sources
PubMed2000

Regenerative periodontal surgery in interproximal intrabony defects with biodegradable barriers.

AIM: The comparison of the effects of guided-tissue regeneration (GTR) using 2 different biodegradable barriers (polylactide acetyltributyl citrate; polydioxanon) in 3- and 2-wall intrabony defects. METHOD: The polydioxanon barrier is an experimental membrane for GTR therapy that consists of an continuous occlusive barrier that has a layer of slings on the side that is meant to face the mucoperiosteal flap. 15 patients provided 15 pairs of similar contralateral periodontal defects: 12 predominantly 2-wall and 18 predominantly 3-wall intrabony defects. Each defect was randomly assigned to treatment with either polylactide acetyltributyl citrate (control [c]) or polydioxanon (test [t]) devices. At baseline and 6 months after surgery, clinical measurements (P1I, GI, PPD, PAL-V) were performed. RESULTS: Barrier exposure was commonly observed in both groups (control/test): 5/4 after 7 days, 9/11 after 14 days and 11/12 after 28 days postsurgically. 4 weeks after surgery, 77% of all barriers were exposed to some extent. However, both treatments revealed a significant GI reduction (p<0.05), PPD reduction [-4.63+/-1.85 mm (t), -4.17+/-1.89 mm (c); p<0.001] and PAL-V gain [3.97+/-1.17 mm (t), 3.40 mm+/-1.40 (c); p<0.001] 6 months after surgery. Regarding GI and PPD reduction as well as PAL-V gain, there were neither statistically significant nor clinically relevant differences between test and control: similar clinical results were found 6 months after surgical treatment using both biodegradable barriers. CONCLUSIONS: Based on the results of the present study, the use of both biodegradable barriers in GTR therapy may be recommended.

Absorbable Implants↗
PubMed2000

Guided tissue regeneration with bioabsorbable barriers: intrabony defects and class II furcations.

BACKGROUND: The aim of this study was to compare the effects of guided tissue regeneration (GTR) using 2 different bioabsorbable barriers (control: polylactide acetyltributyl citrate; test: polydioxanon). The polydioxanon barrier is an experimental membrane for GTR therapy that consists of a continuous occlusive barrier that has a layer of slings on the side that is meant to face the mucoperiosteal flap. METHODS: In 21 patients with 22 pairs of similar contralateral defects (30 intrabony and 14 Class II furcation lesions), each defect was randomly assigned for treatment with either control (c) or test (t) devices. At baseline and 12 months after surgery, clinical measurements, plaque index (PI) gingival index (GI), probing depth (PD), and vertical and horizontal clinical attachment loss (CAL-V; CAL-H) and standardized radiographs were obtained. RESULTS: Barrier exposure was commonly observed in both groups. Four weeks after surgery 61% of all barriers were exposed to some extent. However, both treatments revealed a significant GI reduction (P <0.005), PD reduction (-3.08 +/- 2.29 mm [t]; -3.52 +/- 2.67 mm [c]; P <0.001) and CAL-V gain (2.44 +/- 2.29 mm [t], 2.80 mm +/- 2.21 [c]; P <0.001) 12 months after surgery in all defects. Within the intrabony defects significant bony fill (2.03 +/- 1.70 mm [t]; 1.91 +/- 1.20 mm [c]; P = 0.001), and within the furcations a significant but small CAL-H gain (0.79 +/- 0.68 mm [t]; 1.13 +/- 1.44 mm [c]; P <0.05), was observed. CONCLUSIONS: Regarding GI and PD reduction as well as CAL-V and CAL-H gain, this study failed to reveal statistically significant or clinically relevant differences between test and control 12 months postsurgically. Thus, the use of both bioabsorbable barriers in GTR therapy may be recommended.

Absorbable Implants↗
PubMed2000

A telemedical approach to the screening of diabetic retinopathy: digital fundus photography.

OBJECTIVE: The importance of screening for diabetic retinopathy has been established, but the best method for screening has not yet been determined. We report on a trial of assessment of digital photographs by telemedicine compared with standard retinal photographs of the same fields and clinical examination by ophthalmologists. RESEARCH DESIGN AND METHODS: A total of 129 diabetic inpatients were screened for diabetic retinopathy by slit-lamp biomicroscopy performed by an ophthalmologist and by two-field 50 degrees non-stereo digital fundus photographs assessed by six screening centers that received the images by electronic mail. Conventional 35-mm transparencies of the same fields as the digital photographs were assessed by a retinal specialist and served as the reference method for detection of diabetic retinopathy. Slit-lamp biomicroscopy was the reference method for the detection of macular edema. RESULTS: The prevalence of any form of diabetic retinopathy was 30% (n = 35); of sight-threatening retinopathy including macular edema, the prevalence was 6% (n = 7). The assessment of digital images by the six screening centers resulted in a median sensitivity of 85% and a median specificity of 90% for the detection of moderate nonproliferative or sight-threatening diabetic retinopathy. Clinically significant macular edema (n = 4) was correctly identified in 15 of the 24 grading reports. An additional seven reports referred the patients for further investigation because of concurrent diabetic retinopathy. CONCLUSIONS: Telescreening for diabetic retinopathy by an assessment of two-field 50 degrees non-stereo digital images is a valid screening method. Although detection of clinically significant macular edema using biomicroscopy is superior to digital or standard non-stereo photographs, only few patients with sight-threatening diabetic retinopathy are missed.

Computer Communication Networks↗
PubMed1999

Differential therapy effects of psychoeducational psychotherapy for schizophrenic patients--results of a 2-year follow-up.

There is increasing evidence of the efficacy and effectiveness of psychosocial interventions in schizophrenic patients. However, little research has been done on differential therapy effects. In a prospective, randomized clinical trial we carried out psychoeducational medication management training, cognitive psychotherapy, and key-person counseling. The patients of the control group participated in structured free-time activities for control of therapeutic commitment. Data from a total of 156 schizophrenic patients (DSM-III-R, no first-admissions) were available at 2-year follow-up. We analyzed in this study whether there are differential therapy effects of these interventions, depending on patient characteristics at baseline. There was a significant statistical interaction between treatment condition (specific/non-specific) and prognosis with respect to treatment outcome. Patients with a favorable prognosis and better social functioning had a better course under the specific treatment but a less favorable outcome in the non-specifically treated control group. These results suggest that more vulnerable patients are not sufficiently capable of learning and using coping strategies for relapse prevention. We need to learn more about differential indications for psychosocial treatment.

Adult↗
PubMed1999

Interexaminer reliability of the assessment of clinical furcation parameters as related to different probes.

The aim of this study was to investigate the interexaminer reliability of the assessment of clinical furcation diagnosis. Horizontal attachment level (PAL-H) measurements were obtained by 3 examiners in 6 molars in each of 10 patients with advanced periodontitis. In each patient, 3 molars were examined using a 3 mm incrementally marked Nabers probe, and 3 molars were examined using a pressure-calibrated plastic probe (TPS). Assignment of the probe was random, and the schedule of examiners was changed for each patient. Clinical assessments were validated by intrasurgical measurements in 6 patients. Sixty molars with 152 furcations were investigated. Multifactorial analysis of variance revealed that PAL-H measurements were significantly influenced by examiner and furcation location, whereas type of probe and schedule of examination had no influence. The overall intraclass correlation coefficient was r = 0.695. The difference between clinical and intrasurgical PAL-H assessment was influenced by examiner and location but not by type of probe. Approximately 70% of the total variance of PAL-H measurements was due to the variance of true values, whereas 30% of the variance may be explained by interexaminer and intraexaminer variance. The pressure-calibrated TPS probe failed to increase the interexaminer reliability of PAL-H measurements when compared to a Nabers probe.

Adolescent↗
PubMed1999

Evaluation of telemedical services.

With the rapidly increasing development of telemedicine technology, the evaluation of telemedical services becomes more and more important. However, professional views of the aims and methods of evaluation are different from the perspective of computer science and engineering or from medicine and health policy. We propose that a continuous evaluation strategy should be chosen which guides the development and implementation of telemedicine technologies and applications. The evaluation strategy is divided into four phases in which the focus of evaluation is shifted from technical performance of the system in the early phases to medical outcome criteria and economical aspects in later phases. We review the study design methodology established for clinical trials assessing therapeutic effectiveness and diagnostic accuracy and discuss how it can be adapted to evaluation studies in telemedicine. As an example, we describe our approach to evaluation in a teleconsultation network in ophthalmology.

Evaluation Studies as Topic↗
PubMed1999

[Simple volumetry of ischemic cerebral infarction using computerized tomography. Interobserver and method comparison].

PURPOSE: To study the reliability of brain infarct volume assessment with ruler and calculator. METHODS: The brain infarctions of 45 patients were measured using 3 different methods on CT scans: In each section showing the lesion, the largest diameters were measured and multiplied by the slice thickness using the formula for A) an ellipsoid and B) a cylinder. The sectional volumes were summed up to calculate the entire lesion volume. C) Using the ellipsoid formula, the thickness of all sections showing the lesion were added and used as the third diameter which was multiplied with the two largest diameters of the lesion. The lesion volume was also assessed by planimetry on a workstation and served as reference. Using method A, two independent investigators measured 93 brain infarcts of 49 patients to assess the 95% confidence interval (CI) of agreement. RESULTS: Compared to the reference, method A underestimated the volumes by -25%, method B overestimated the volumes by +12.5%, and method C by +18.6%. The mean difference between the two investigators was 2 ml. The 95% CI for small infarcts < or = 50 ml was 60%-150%, for larger infarcts +/- 26 ml. CONCLUSION: This simple method is only reliable when changes in infarct volume exceeding 26 ml are to be detected.

Brain↗
PubMed1998

Antimicrobial peptides melittin and cecropin inhibit replication of human immunodeficiency virus 1 by suppressing viral gene expression.

Antimicrobial peptides are effectors of innate immunity, providing their hosts with rapid non-specific defence against parasitic invaders. In this report, the effects are assessed of two well-characterized antimicrobial amphipathic peptides (melittin and cecropin) on human immunodeficiency virus 1 (HIV-1) replication and gene expression in acutely infected cells at subtoxic concentrations. Production of infectious, cell-free virus was inhibited in a dose-dependent manner, with ID50 values in the range 0.9-1.5 microM for melittin and 2-3 microM for cecropin. Analysis of the effect of melittin on cell-associated virus production revealed decreased levels of Gag antigen and HIV-1 mRNAs. Transient transfection assays with HIV long terminal repeat (LTR)-driven reporter gene plasmids indicated that melittin has a direct suppressive effect on activity of the HIV LTR. HIV LTR activity was also reduced in human cells stably transfected with retroviral expression plasmids for the melittin or cecropin gene. It is concluded that antimicrobial peptides such as melittin and cecropin are capable of inhibiting cell-associated production of HIV-1 by suppressing HIV-1 gene expression.

Anti-Infective Agents↗
PubMed1998

Regenerative periodontal surgery with non-resorbable and biodegradable barriers: results after 24 months.

The aim of the present study was to compare the effects of guided tissue regeneration (GTR) with non-resorbable (ePTFE) and biodegradable barriers (Polyglactin 910). 23 patients provided 29 pairs of similar contralateral periodontal defects (12 pairs of interproximal intrabony lesions, 11 pairs of degree II and 6 pairs of degree III furcation defects). Each defect was randomly assigned to treatment with either non-resorbable (control [c]) or biodegradable (test [t]) devices. At baseline, 6, 12, 18, and 24 months after surgery, clinical measurements (PlI, GI, PPD, PAL-V, PAL-H) were performed. Standardized radiographs were obtained at baseline 12 and 24 months postsurgically. On the radiographs, the linear distances from the cemento-enamel junction (CEJ) to the alveolar crest (AC) and from the CEJ to bottom of the bony defect (BD) were measured using a computer-assisted analysing method (LMSRT). Both treatments revealed a significant (p<0.05) PPD reduction [all defects: -2.97 +/- 1.90 mm (t), -2.21 +/- 1.73 mm (c); intrabony defects: -4.00 +/- 1.96 mm (t), -3.00 +/- 1.87 mm (c); degree II furcations: -2.67 +/- 0.97 mm (t), -2.08 +/- 1.54 mm (c)], PAL-V gain [all defects: 2.02 +/- 1.83 mm (t), 1.18 mm +/- 1.50 (c); intrabony defects: 3.45 +/- 1.48 mm (t), 1.95 +/- 1.64 mm (c); degree II furcations: 1.33 +/- 0.94 mm (t), 0.92 +/- 1.47 mm (c)], PAL-H gain [degree II furcations: 2.22 +/- 0.94 mm (t), 1.86 +/- 0.60 mm (c)], and radiographic changes [CEJ-AC: -0.56 +/- 1.98 mm (t), -0.06 +/- 1.19 mm (c); CEJ-BD: 2.10 +/- 1.92 mm (t), 1.24 +/- 2.04 mm (c)] after 24 months. For degree III furcations, neither statistically significant PPD reduction nor PAL-V gain was observed. Similar clinical and radiographic results were found 12 and 24 months after surgical treatment using either non-resorbable or biodegradable barriers. More favorable results concerning PAL-V gain in interproximal intrabony defects could be observed with biodegradable barriers after 24 months than using nonresorbable membranes. Whereas interproximal intrabony lesions and degree II furcation defects responded favorably to GTR therapy, through-and-through furcations must be looked upon as a contraindication for this regenerative technique. Based on the results of the present study, the use of biodegradable barriers in GTR may be recommended and, thereby, a surgical re-entry to remove nonresorbable barriers can be avoided.

Adult↗
PubMed1997

Is there a gain from "chance-corrected" measures of diagnostic validity?

Several authors have proposed alternatives to sensitivity and specificity which they recommend as so-called "chance-corrected" versions of these parameters of diagnostic validity. We argue that these new measures have some undesirable properties in comparison with the established measures and no substantial advantages. In particular, the extension of this concept to chance-corrected ROC curves is shown to be less useful than classical ROC analysis.

Diagnosis↗
PubMed1997

Psychoeducational psychotherapy for schizophrenic patients and their key relatives or care-givers: results of a 2-year follow-up.

Psychoeducational medication management training (PMT), cognitive psychotherapy (CP) and key-person counselling (KC) were carried out in various combinations in this randomized, controlled intervention study of schizophrenic out-patients (according to DSM-III-R). Special design characteristics of the study were a control group consisting of non-specifically treated patients and a 2-year follow-up after completion of treatment in order to evaluate medium-term effects. A total of 132 patients underwent a follow-up examination 2 years after completion of treatment and were evaluated with an intention-to-treat approach. In the second follow-up year, all treatment groups had lower but not significantly different relapse rates compared to the control group. The most intensive treatment (PMT+CP+KC) produces a clinically relevant reduction in rehospitalization rate (a 26% reduction compared to the control group). In comparison with the non-specifically treated control group, whose original effect decreased, at least a medium-term therapeutic effect was recorded in the treatment groups.

Adult↗
PubMed1997

Guided tissue regeneration with non-resorbable and biodegradable barriers: 6 months results.

The aim of the present study was to compare the effects of guided tissue regeneration (GTR) with non-resorbable (ePTFE [G]) and biodegradable barriers (Polyglactin 910 (V)). In 20 patients, providing 25 pairs of symmetrical periodontal defects (7 pairs of interproximal intrabony lesions, 12 pairs of degree II and 6 pairs of degree III furcation involvement), each defect was randomly assigned to treatment with either non-resorbable (control) or biodegradable (test) devices. At baseline and 6 months after surgery, clinical measurements (GI, PPD, PAL-V, PAL-H, P1I) and standardized radiographs were obtained. On the radiographs, the linear distances from the cemento-enamel junction (CEJ) to the alveolar crest (AC), and from the CEJ to bottom of the bony defect (BD) were measured using a computer-assisted analysing method (LMSRT). Both treatments revealed a significant (p < 0.05) PPD reduction (-2.90 +/- 1.33 mm (V), -2.71 +/- 1.41 mm (G)), PAL-V gain (1.78 +/- 1.27 mm (V), 1.46 +/- 1.35 mm (G)), PAL-H gain (2.00 +/- 0.82 mm (V), 1.60 +/- 0.59 mm (G)), and radiographic changes (CEJ-AC: 0.48 +/- 0.75 mm (V), 0.73 +/- 0.92 mm (G); CEJ-BD: -0.76 +/- 0.79 mm (V), -0.41 +/- 0.72 mm (G)) after 6 months. The mean differences between the changes for test and control were not significant for most clinical and radiographic parameters. Similar clinical and radiographic results were found 6 months after surgical treatment using either non-resorbable or biodegradable barriers. More favorable results concerning PAL-H gain could be observed with biodegradable barriers after 6 months. Therefore, based on these results, the use of biodegradable barriers in GTR may be recommended and, thereby, a surgical re-entry to remove non-resorbable barriers can be avoided.

Adult↗
PubMed1997

Acute stroke: usefulness of early CT findings before thrombolytic therapy.

PURPOSE: To determine whether the extent of subtle parenchymal hypoattenuation detected on computed tomographic (CT) scans obtained within 6 hours of ischemic stroke is a factor in predicting patients' response to thrombolytic treatment. MATERIALS AND METHODS: The baseline CT scans of 620 patients, who received either recombinant tissue plasminogen activator (rt-PA) or a placebo, in a double-blind, randomized multicenter trial were prospectively evaluated and assigned to one of three categories according to the extent of parenchymal hypoattenuation: none, 33% or less (small), or more than 33% (large) of the middle cerebral artery territory. The association between the extent of hypoattenuation on the baseline CT scans and the clinical outcome in the placebo-treated and the rt-PA-treated groups after 3 months was analyzed. RESULTS: In 215 patients with a small hypoattenuating area, treatment increased the chance of good outcome. In 336 patients with a normal CT scan and in 52 patients with a large hypoattenuating area, rt-PA had no beneficial effect but increased the risk for fatal brain hemorrhage. CONCLUSION: The response to rt-PA in patients with ischemic stroke can be predicted on the basis of initial CT findings of the extent of parenchymal hypoattenuation in the territory of the middle cerebral artery.

Acute Disease↗
PubMed1997

Prognosis of stroke patients requiring mechanical ventilation in a neurological critical care unit.

BACKGROUND AND PURPOSE: Intubation and mechanical ventilation are sometimes necessary during treatment of acute stroke. Indications include neurological deterioration, pulmonary complications, and elective intubation for procedures and surgery. Prognosis in severe stroke patients requiring mechanical ventilation has often been reported to be poor. This study was performed to prospectively assess the prognosis of stroke patients who require ventilation in a neurological intensive care unit and to determine factors that may influence outcome. METHODS: Analysis was made of 124 consecutive stroke patients who required mechanical ventilation over a 2-year period. We determined the survival rate at 1 year after admission. Initial clinical data, history of previous diseases, and indication for intubation were analyzed for prognostic significance by univariate and multiple logistic regression analysis. RESULTS: The 1-year survival rate was 33.1% (n = 41). Sixty-five patients (52%) died in the neurological intensive care unit. Among 17 variables analyzed, seven were found to significantly influence 2-month fatality in the univariate analysis: age greater than 65 years, atrial fibrillation, bilateral absence of pupillary light reflex, bilateral absence of corneal reflex, bilateral Babinski's sign, infratentorial stroke, and Glasgow Coma Scale (GCS) score less than 10. Independent predictors of death at 2 months were age greater than 65 years (P = .03), GCS score less than 10 (P = .01), and intubation performed because of coma or acute respiratory failure (P = .04). CONCLUSIONS: Overall prognosis of ventilated patients with severe stroke is better than previously reported. Older patients comatose on admission who need to be intubated because of neurological or respiratory deterioration have the poorest prognosis. We conclude that intubation and mechanical ventilation of severe stroke patients should be performed in a timely manner, before irreversible damage occurs.

Activities of Daily Living↗
PubMed1996

Micrometastatic breast cancer cells in bone marrow at primary surgery: prognostic value in comparison with nodal status.

BACKGROUND: Approximately 30% of the patients with primary breast cancer who have no axillary lymph node involvement (i.e., lymph node negative) at the time of surgery will relapse within 10 years; 10%-20% of the patients with distant metastases will be lymph node negative at surgery. Axillary lymph node dissection, as a surgical procedure, is associated with frequent complications. A possible alternative to nodal dissection in terms of prognosis may be the immunocytochemical detection of tumor cells in bone marrow. PURPOSE: In a prospective study, the value of tumor cell detection (TCD) in bone marrow was compared with axillary lymph node dissection in the prognosis of primary breast cancer after surgery. METHODS: Data from 727 patients with primary, operable breast cancer were included in the analysis. All patients had surgery, including axillary lymph node dissection, from May 1985 through July 1994 at the Women's Hospital of the University of Heidelberg (Federal Republic of Germany). Bone marrow aspiration at two sites on each anterior iliac crest was performed immediately after surgery while the patients were under general anesthesia. Most patients received some type of systemic adjuvant therapy. The monoclonal antibody 2E11, directed against the polymorphic epithelial mucin TAG12, was used to detect tumor cells in bone marrow samples. The association of TCD with recognized prognostic indicators was evaluated by means of chi-squared tests. Survival without the development of distant metastases (i.e., distant disease-free survival) and overall survival were estimated by use of the Kaplan-Meier method; the logrank test was used to compare survival curves. A multivariate Cox regression analysis with stratification according to adjuvant treatment type was used to assess the independent prognostic value of TCD in bone marrow in relation to other variables. Reported P values are two-sided. RESULTS: Tumor cells were detected in the bone marrow of 203 (55%) of 367 lymph node-positive patients and in 112 (31%) of 360 lymph node-negative patients. TCD was associated with larger tumors (P < .001), lymph node involvement (P = .001), and higher tumor grade (i.e., more undifferentiated) (P = .002). After a median follow-up of 36 months, patients with tumor cells in their bone marrow experienced reduced distant disease-free survival and overall survival (both P values < .001). TCD was an independent prognostic indicator for both distant disease-free survival and overall survival that was superior to axillary lymph node status, tumor stage, and tumor grade. Among patients with tumors less than 2 cm in diameter, TCD was the most powerful predictor of outcome. CONCLUSIONS AND IMPLICATIONS: TCD in the bone marrow of patients with breast cancer is a valuable prognostic tool associated with negligible morbidity. Prospective randomized studies should be performed to determine whether TCD might replace axillary lymph node dissection in a defined subgroup of patients with small tumors.

Adult↗
PubMed1996

Predictors of 10-year macrovascular and overall mortality in patients with NIDDM: the Munich General Practitioner Project.

The 10-year follow-up of the Munich General Practitioner Project was designed as a long-term prospective study to evaluate factors predicting macrovascular and overall mortality in a random cohort of non-insulin-dependent diabetic (NIDDM) patients. Of the original 290 patients (103 males, 187 females, median age 65 years) 92.5% could be assessed, 103 subjects had died, 58 from macrovascular causes. In an univariate analysis of baseline data, deceased patients, and especially those who died from macrovascular causes had significantly higher fasting blood glucose, HbA1c, von Willebrand-factor protein, urine albumin excretion, and serum beta 2-microglobulin, were significantly older, exhibited significantly more ischaemic heart disease (abnormal ECG Minnesota codes), carotid artery and peripheral vascular disease (both determined by ultrasound-Doppler), and had significantly inferior knowledge about diabetes and its treatment. No significant differences were seen for gender, blood pressure, smoking, total cholesterol, triglycerides, HDL-cholesterol, or the use of antidiabetic, antihypertensive or coronary drugs. In a multiple logistic regression analysis, the risk factors for macrovascular death were age, HbA1c and von Willebrand-factor protein. When baseline macrovascular disease was taken into account, carotid artery disease was also a determinant. The main variables from the metabolic syndrome (blood pressure, dyslipidaemia, body mass index) did not enter a multiple logistic regression analysis. The data suggest that age and haemoglobin A1c are major determinants, and that in addition von Willebrand-factor associated endothelial damage is a risk factor for macrovascular mortality in NIDDM patients.

Age Factors↗