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Biomedical subjects

K Schnabel

Publications and source records attributed to K Schnabel.

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

Progressive development of diffuse liver hemangiomatosis.

Diffuse liver hemangiomatosis is extremely rare. The etiology and natural history of the disease are unknown. It is also unclear whether tumor growth is induced or modulated by drug therapy. Tumor recurrence after ablative therapy has not been described in patients with diffuse liver hemangiomatosis. Diffuse hemangiomatosis of the left hepatic lobe was suspected in a 35-year-old woman by ultrasonography, CT and hepatic arteriography, and confirmed by laparotomy and biopsies. The patient denied any drug or estrogen use. The tumor was removed by left hepatectomy. Two and six years later, the patient was again hospitalized with progressive tumor growth into the right hepatic lobe. Although diffuse liver hemangiomatosis is a rare disease, its diagnosis should be considered in patients with progressive tumor growth in one or both hepatic lobes. The absence of drug intake or estrogen use does not exclude the diagnosis.

Adult↗
PubMed1999

Patients' vs nurses' assessments of postoperative pain and anxiety during patient- or nurse-controlled analgesia.

We have compared patients' and nurses' assessments of postoperative pain and anxiety after different analgesic treatments. Sixty orthopaedic patients were allocated randomly to receive i.v. piritramide (either nurse-controlled or patient-controlled) or subarachnoid bupivacaine (nurse-controlled or patient-controlled). Patients and nurses assessed pain and anxiety using a visual analogue scale (VAS; 1-100 mm). Pain and anxiety ratings of patients and nurses were significantly correlated (Spearman's r > or = 0.69; P < 0.001). In general, patients' pain scores were higher than nurses' scores (patients' median VAS = 34 (range 1-76) mm; nurses VAS 21 (1-59) mm) and for all groups except the patient-controlled subarachnoid bupivacaine group, where they were significantly higher (P < 0.01). Discrepancy in pain estimates between patients and nurses increased with the level of pain. The relationship between patients' and nurses' anxiety scores was less clearly defined and did not depend on the level of anxiety.

Adolescent↗
PubMed1999

Late radiation toxicity after whole brain radiotherapy: the influence of antiepileptic drugs.

This retrospective study had the following aims: (a) calculation of actuarial rate of late radiation toxicity after whole-brain radiotherapy (WBRT), (b) correlation of clinical symptoms with changes of computed tomography (CT) scans, and (c) analysis of potentially predictive factors with special regard to concomitant treatment with antiepileptic drugs. We analyzed 49 adult patients, selected from a preexisting data base. Inclusion criteria were as follows: no previous brain irradiation; WBRT without boost; CT, clinical, and neurologic examination before and more than 3 months after completion of WBRT. Uni- and multivariate tests of various patient- and treatment-related parameters as possible predictive factors for clinical symptoms of late radiation toxicity (scored according to the RTOG/EORTC system) as well as cerebral atrophy and white matter abnormalities were performed. Median age was 54 years. Patients were treated for brain metastases (n = 37), primary cerebral lymphoma (n = 2), primary brain tumors (n = 7), or with prophylactic intention (n = 3). Carbamazepine was given to 15 patients, phenytoin to 12, and barbiturate to 7, respectively; 42 patients also received corticosteroids. The median dose of WBRT was 30 Gy (range 27-66 Gy). Median fraction size was 3 Gy (1-3 Gy). Nine patients received two fractions per day. The biologically effective dose (BED) according to the linear-quadratic model ranged between 90 and 141 Gy (median, 120 Gy; alpha/beta value, 1 Gy). Median follow-up was 10 months (range, 4-130 months). In 16 cases, symptoms of late radiation toxicity grade I-III appeared. Actuarial rates were 32% after 1 year, 49% after 2 years, and 83% after 5 years. Actuarial rates of cerebral atrophy were 50% after 1 year and 84% after 2 years (white matter abnormalities: 25% and 85%, respectively). There was a significant correlation between atrophy and white matter abnormalities, but not between CT changes and clinical symptoms. CT changes were dependent on BED, absence of barbiturate use, and preexisting cerebral atrophy. Clinical symptoms usually were dependent on BED too, but treatment with carbamazepine was more important in the multivariate model. Neither other drugs nor other factors influenced late radiation toxicity. A detailed analysis showed that most carbamazepine-treated symptomatic patients took the drug during WBRT as well as during follow-up. Actuarial rates of grade I-III symptoms were 18% versus 50% after 1 year with or without carbamazepine. Even after exclusion of carbamazepine-treated patients, CT changes and clinical symptoms did not correlate. In conclusion, a BED <120 Gy was associated with a lower rate of late radiation toxicity after WBRT. The anticonvulsant drug carbamazepine showed a surprisingly clear influence on clinical symptoms of late radiation toxicity; that might be explained by the fact that the side effects of long-term drug treatment are indistinguishable from mild or moderate true radiation sequelae, rather than that it has a role in the pathogenesis of radiation-induced changes.

Actuarial Analysis↗
PubMed1999

Effect of combined mouth closure and chin lift on upper airway dimensions during routine magnetic resonance imaging in pediatric patients sedated with propofol.

BACKGROUND: In pediatric patients, obstruction of the upper airway is a common problem during general anesthesia. Chin lift is a commonly used technique to improve upper airway patency. However, little is known about the mechanism underlying this technique. METHODS: The authors studied the effect of the chin lift maneuver on airway dimensions in 10 spontaneously breathing children (aged 2-11 yr) sedated with propofol during routine magnetic resonance imaging. The minimal anteroposterior and corresponding transverse diameters of the pharynx were determined at the levels of the soft palate, dorsum of the tongue, and tip of the epiglottis before and during the chin lift maneuver. Additionally, cross-sectional areas were calculated at these sites, including tracheal areas 2 cm below the glottic level. RESULTS: Minimal anteroposterior diameter of the pharynx increased significantly during chin lift at all three levels in all patients. The diameters of the soft palate, tongue, and epiglottis increased from 6.7+/-2.8 mm (SD) to 9.9+/-3.6 mm, from 9.6+/-3.6 mm to 16.5+/-3.1 mm, and from 4.6+/-2.5 mm to 13.1+/-2.8 mm, respectively. The corresponding transverse diameter of the pharynx also increased significantly at all three levels in all patients but without significant predominance. The diameters at the levels of the soft palate, tongue, and epiglottis increased from 15.8+/-5.1 mm to 22.8+/-4.5 mm, from 13.5+/-4.9 mm to 18.7+/-5.3 mm, and from 17.2+/-3.9 mm to 21.2+/-3.7 mm, respectively. Cross-sectional pharyngeal areas increased significantly at all levels (soft palate, from 0.88+/-0.58 cm2 to 1.79+/-0.82 cm2; tongue, from 1.15+/-0.45 cm2 to 2.99+/-1.30 cm2; epiglottis, from 1.17+/-0.70 cm2 to 3.04+/-0.99 cm2), including the subglottic level (from 0.44+/-0.15 cm2 to 0.50+/-0.14 cm2). CONCLUSIONS: This study shows that all children had a preserved upper airway at all measured sites during propofol sedation. Chin lift caused a widening of the entire pharyngeal airway that was most pronounced between the tip of the epiglottis and the posterior pharyngeal wall. In pediatric patients, chin lift may be used as a standard procedure during propofol sedation.

Child↗
PubMed1999

Detection of human herpesvirus 6 by reverse transcription-PCR.

The role of human herpesvirus 6 (HHV-6) in disease beyond primary infection remains unclear. We have developed and validated a new reverse transcription-PCR (RT-PCR) assay for HHV-6 that can determine the presence of HHV-6 in clinical specimens and differentiate between latent and replicating virus. Peripheral blood mononuclear cells from 109 children were evaluated for HHV-6 by RT-PCR, DNA PCR, and viral culture. Of these samples, 106 were suitable for analysis. A total of 20 samples were positive for HHV-6 by culture and DNA PCR, of which 19 were positive by RT-PCR (sensitivity, 95%). All 28 samples from children that were negative by viral culture, but positive by DNA PCR, were negative for viral transcripts by our RT-PCR assay. One positive RT-PCR result was observed in 56 samples that were negative by tissue culture and DNA PCR. This indicates a low rate of false-positive results (1.2%) and a specificity of 98.8%. This RT-PCR assay can reliably differentiate between latent and actively replicating HHV-6 and should allow insight into the pathogenesis of this ubiquitous virus.

Base Sequence↗
PubMed1999

[Palliative accelerated irradiation for advanced non-small-cell lung bronchial carcinoma: results of a pilot study].

In order to reduce the aggressivity of radiotherapy of very advanced non-small-cell lung cancer (NSCLC), and to shorten treatment time, a palliative accelerated irradiation regimen (PAIR) was developed. Before the onset of a randomised study, we performed a one-year pilot study, of which the paper presented here gives the results after complete follow-up. 34 patients (S) with locally inoperable advanced NSCLC stage III (74%) and IV (26%) were irradiated with accelerated fractionation schedule, focussing on tumour and mediastinum, with a total dose of 32 Gy (PAIR, 2 x 2 Gy/d). Treatment results were compared to those of a group of 178 controls (K) treated conventionally, who were selected from a preexisting database according to study inclusion criteria (tab. 2-5 stage III 65%, IV 35%). 105 of them had been treated with a total dose of 60 Gy (K60). After complete follow-up a final evaluation was made. Local control did not differ significantly between both groups, and not between groups S and K60 (tab. 6, fig. 2). Median survival for all patients (S + K) was 6 months. With 8.7 months, that of the study patients (S) was significantly longer than that of the controls (K, fig. 1). This was also true of stage III. Comparison with the 60-Gy-controls (K60) did not reveal significant survival differences. In Cox regression analysis independent prognostic factors were: Karnofsky index, UICC stage, and N stage. Concerning the palliation of tumour-related symptoms, both therapies were comparable (tab. 7). The side-effects were moderate and also comparable. These results induced us start a randomized study comparing both regimens in respect of prognosis and palliation.

Carcinoma, Non-Small-Cell Lung↗
PubMed1999

[Implantation metastasis at the exit site after percutaneous endoscopic gastrostomy in esophageal carcinoma].

In patients with esophageal cancer causing obstruction percutaneous endoscopic gastrostomy (PEG) is a well-established procedure with a low complication rate to provide sufficient enteral nutrition. We report on a 68-year-old patient suffering from inoperable squamous cell cancer of the proximal esophagus, who underwent PEG insertion prior to a combined radiochemotherapy. Initially bougienage was performed because of subtotal esophageal stenosis. Four months later a metastasis was found at the PEG exit site with involvement of the gastric wall, most likely caused by spread of tumor cells during insertion of the PEG.

Aged↗
PubMed1998

Multivariate logistic analysis of dose-effect relationship and latency of radiomyelopathy after hyperfractionated and conventionally fractionated radiotherapy in animal experiments.

PURPOSE: We examined in rats whether the radiation tolerance of spinal cord is enhanced by using hyperfractionated radiotherapy compared to a conventional schedule. Higher tolerable doses to the spinal cord would allow dose escalation to the tumor and thus possibly lead to higher cure rates, especially in tumors with high cell proliferation. METHODS AND MATERIALS: Cervical spinal cord of 276 healthy rats was irradiated over 6 weeks hyperfractionally with single doses ranging from 0.75-2.5 Gy up to total doses ranging from 45-150 Gy (60 fractions) and conventionally with single doses of 1.5-4.0 Gy up to total doses of 45-120 Gy (30 fractions). The rats were examined neurologically and sacrificed when paralysis of the hind legs occurred. After fixation, spinal cord was removed and examined histologically. Dose-effect relationship and latency from the beginning of radiotherapy to the onset of paralysis were computed and analyzed using a multivariate logistic regression model. RESULTS: The model fitted the observed data excellently. There were highly significant effects both for the dose level and for the treatment regimen. Latency analysis showed earlier and more intense acute side effects after hyperfractionation but radiomyelopathy occurred markedly later. CONCLUSIONS: The sparing effect of hyperfractionation on spinal cord as predicted by radiobiologists could be confirmed in our experiments. Thus, it seems possible to escalate tumor doses using hyperfractionation without enhanced risk to spinal cord but with higher probability of tumor cure.

Animals↗
PubMed1998

Patterns of relapse and late toxicity after resection and whole-brain radiotherapy for solitary brain metastases.

BACKGROUND: This retrospective analysis was performed in order to evaluate the pattern of relapse and the risk of late toxicity for solitary brain metastases treated with surgery and whole-brain radiotherapy and to correlate the results with those from radiosurgical trials. PATIENTS AND METHODS: From a total of 66 patients, 52 received 10 x 3 Gy and 10 were treated with 20 x 2 Gy whole-brain radiotherapy after resection of their brain metastases. RESULTS: The actuarial probability of relapse was 27% and 55% after 1 and 2 year(s), respectively. The local relapse rate (at the original site of resected brain metastases) was rather high for melanoma, non-breast adenocarcinoma, and squamous-cell carcinoma. No local relapse occurred in breast cancer and small-cell carcinoma. Failure elsewhere in the brain seemed to be influenced by extracranial disease activity. Size of brain metastases and total dose showed no correlation with relapse rate. Occurrence of brain relapse was not associated with a reduced survival time, because 10/15 patients who developed a relapse received salvage therapy. Of the patients, 11 had symptoms of late radiation toxicity (the actuarial probability was 42% after 2 years). CONCLUSIONS: Most results of surgical and radiosurgical studies are comparable to ours. Several randomized trials investigate surgical resection versus radiosurgery, as well as the effects of additional whole-brain radiotherapy in order to define the treatment of choice. Some data support the adjuvant application of 10 x 3 Gy over 2 weeks as a reasonable compromise when local control, toxicity, and treatment time have to be considered.

Actuarial Analysis↗
PubMed1998

Dose/effect relationships for brain metastases.

PURPOSE: Only in selected patients with brain metastases, e.g. those with controlled or absent extracranial tumour, may application of higher total doses of radiotherapy improve survival. However, local control is the prerequisite for long-term survival. This study aimed to answer the question whether or not local control can be improved by dose escalation. METHODS: Computed tomography scans of 322 patients were analysed in order to evaluate the best local result after radiotherapy and the time to local progression. Total doses of 25-60 Gy were administered (single doses 1.8-5 Gy). The biologically effective dose (BED10) was calculated for statistical evaluation according to the linear-quadratic model assuming an alpha/beta-value of Gy. It ranged between 37.5 Gy and 72 Gy. RESULTS: The best local result was dependent on the number of brain metastases, BED and the histology of the primary tumour (small-cell and breast carcinoma had higher remission rates than squamous-cell carcinoma, non-breast adenocarcinoma and others). Partial remission rates significantly increased with BED, whereas complete remission rates did not improve. Histology was the only significant factor in multivariate tests. The 1-year-failure rate improved with increased BED from 44% to 31% (P > 0.05). Overall survival (median 3 months) was not dependent on total dose. CONCLUSIONS: Previous studies suggested that a prolongation of survival can be achieved through better local management (e.g. surgery plus radiotherapy, radiosurgery). However, it is still uncertain whether conventional external-beam radiotherapy with higher total doses leads to comparable results. The optimum dose level still has to be established. For squamous-cell carcinoma and adenocarcinoma a BED of at least 72 Gy seems to be necessary, for small-cell and breast carcinoma, doses between 48 Gy and 60 Gy might be sufficient. The important influence of tumour histology on local remission and progression-free survival should be considered when planning future clinical trials.

Adult↗
PubMed1998

Primary human herpesvirus 7 infection: a comparison of human herpesvirus 7 and human herpesvirus 6 infections in children.

OBJECTIVE: To define the clinical and virologic characteristics of primary human herpesvirus 7 (HHV-7) infection and to compare these characteristics with those of primary human herpesvirus 6 (HHV-6) infection. STUDY DESIGN: A prospective convenience sample study of 496 children < or =3 years old. HHV-7 and HHV-6 infections were identified by viral isolation. Polymerase chain reaction and serology for HHV-7 and HHV-6 were performed. Clinical and laboratory characteristics of patients were obtained from medical records and follow-up interviews. RESULTS: Children with primary HHV-7 infection (n = 8) were identified and compared with children with primary HHV-6 infection (n = 29) detected during the same time period. All children were febrile (mean temperature 39.8 degrees C) with no difference in the degree of fever, frequency of rash, or gastrointestinal complications between the groups. The median age of children with primary HHV-7 infection was 26 months, significantly older than that of children with primary HHV-6 infection (median, 9 months). Children with primary HHV-7 infection were also more likely than those with primary HHV-6 infection to have seizures associated with the illness (P = .004). CONCLUSION: Primary infection with HHV-7 can cause a highly febrile illness in childhood, complicated by seizures. The serologic diagnosis of primary HHV-6 and HHV-7 infections may be confounded by cross-reacting antibodies.

Age Factors↗
PubMed1998

Subarachnoid and intravenous PCA versus bolus administration for postoperative pain relief in orthopaedic patients.

BACKGROUND: Patient-controlled analgesia (PCA) with intravenous piritramide and subarachnoid bupivacaine was studied during postoperative pain management in comparison with nurse-administered bolus injections. METHODS: Following general anaesthesia (n = 60) patients randomly received either 3.75-7.5 mg i.v. piritramide on demand (group P-Bolus) or via PCA (group P-PCA; initial bolus: 3.75 mg i.v. piritramide, baseline rate: 1 mg/h, demand-dose 1.5 mg, lockout time: 20 min). Following continuous spinal anaesthesia (n = 60; CSA; 28-G spinal catheter) patients randomly received a subarachnoid injection of 1.5 ml bupivacaine 0.25% every 2-4 h (group B-Bolus) or a baseline infusion of 0.5 ml/h bupivacaine 0.125% plus 0.5 ml bupivacaine 0.125% on demand via PCA (group B-PCA; lockout time: 30 min). Pain ratings were assessed hourly by patients using a visual analogue scale (0 = no pain, 100 mm = unbearable pain). STATISTICS: multivariate analysis of variance. RESULTS: While pain scores did not differ between group P-Bolus and P-PCA, group B-PCA showed the lowest pain ratings (18 +/- 22 mm) differing significantly from group B-Bolus (41 +/- 32 mm; P < 0.001). Group P-PCA required more piritramide than group P-Bolus (46 +/- 15 mg vs. 31 +/- 13 mg, P = 0.001). In contrast group B-PCA required less bupivacaine than group B-Bolus (18 +/- 4 vs. 23 +/- 7 mg, P = 0.002). CONCLUSION: PCA with CSA was more effective than nurse-administered bolus-administration of bupivacaine, while the present study failed to show superiority of i.v. PCA over i.v. bolus-administration of piritramide. PCA using the subarachnoid route is a promising concept for treatment of postoperative pain in orthopaedic patients, while the PCA piritramide regime of this study warrants improvement.

Aged↗
PubMed1997

Tumor-related prognostic factors for remission of brain metastases after radiotherapy.

PURPOSE: To study CT determined response to external beam radiotherapy as well as influence of tumor-related factors, especially of tumor volume, on remission and to evaluate whether particular subgroups of metastases are controlled by low-dose radiotherapy. METHODS AND MATERIALS: Contrast-enhanced CT scans before and after radiotherapy were analyzed. INCLUSION CRITERIA: brain metastases treated with whole-brain radiotherapy (10 fractions of 3 Gy over 2 weeks) since 1983; no additional treatment, for example, surgery or chemotherapy; at least one follow-up CT. Three hundred thirty-six metastases from 108 patients were evaluated with regard to their volume, extent of necrosis, histology of primary tumor, and interval between radiotherapy and follow-up CT. All parameters were correlated with best local result and progression-free survival by uni- and multivariate tests. Volume-response curves were calculated. RESULTS: In univariate analysis local result was significantly influenced by each of the four parameters mentioned above. Complete remission was observed in 37% of metastases from small-cell carcinoma, 35% of those from breast cancer, 25% of those from squamous-cell carcinoma, and 14% of those from nonbreast adenocarcinoma. The rate was 52% for metastases <0.5 cm3 and 0% for those >10 cm3. In multivariate analysis, small volume and no necrosis were the most important prognostic factors for complete remission. Progression-free survival was influenced by best local result. CONCLUSION: With radiotherapy to a total dose of 30 Gy even small metastases had a complete remission rate of 52% only. Therefore, patients should be treated with locally more effective dose and fractionation schedules when local control is the aim. However, partial remission rate was remarkable even for large and necrotic metastases. This should be considered when palliation is the aim of treatment.

Adenocarcinoma↗
PubMed1997

[The "pinch off" syndrome: a complication of implantable catheter systems in the subclavian vein].

We report the case of a 63-year-old male patient who received a subcutaneous Port-a-cath system in the right subclavian vein for administration of chemotherapy. Five weeks after successful use, flushing with NaCl 0.9% caused a painless subcutaneous swelling. Fluoroscopy confirmed a leakage below the right clavicle. The catheter was explanted and replaced by a new catheter via Seldinger technique. Two weeks later another leakage occurred and the catheter was removed definitively. Defective equipment was ruled out by the catheter producing company. The "pinch off" syndrome, a rare phenomenon of catheter compression and consecutive catheter fracture, is described, together with the diagnostic signs, the incidence and preventive measures suggested in the literature.

Antineoplastic Agents↗