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Biomedical subjects

C Goetz

Publications and source records attributed to C Goetz.

At least 19 recordsLinked to original sources
PubMed2003

Locoregional radioimmunotherapy in selected patients with malignant glioma: experiences, side effects and survival times.

UNLABELLED: Prognosis of malignant glioma is very unfavourable mainly due to minimal tumour remnants in the peritumoural tissue. Intralesionally applied radioimmunotherapy is a possible therapeutical option with the potential to improve survival of patients with malignant glioma. We investigated side effects and survival after surgery, conventional radiotherapy and additional radioimmunotherapy with labelled tenascin-antibodies in patients with malignant glioma. METHODS: Since 1995, 37 patients were treated with radioimmunotherapy after resection and radiotherapy of a malignant glioma. Patients received antibodies labelled with yttrium-90 and iodine-131 in different doses into the tumour cavity via a previously implanted ommaya-reservoir. Treatment was applied in up to 8 cycles (mean 2.96 cycles) in time intervals of 6-8 weeks. Mean age was 46 years, histology was anaplastic astrocytoma in 13 patients and glioblastoma in 24 patients. RESULTS: For the whole group median survival time has not yet been reached. For glioblastoma the median survival time is 17 months, 5-year survival probability for anaplastic astrocytoma is 85% approximately. Quality of life was acceptable. Acute side effects following treatment were headache, seizures and worsening of pre-existing neurological symptoms. Late side effects were skin necrosis and, in 1 case, a delayed aphasia probably due to a vascular lesion. CONCLUSION: Radioimmunotherapy prolonged survival time in a selected group of patients with malignant gliomas as compared to a historical control group. Patients with anaplastic astrocytomas seem to have more benefit from this therapy than patients with glioblastomas.

Adult↗
PubMed2002

Experimental research photodynamic effects in perifocal, oedematous brain tissue.

BACKGROUND: Photodynamic therapy (PDT) has been under discussion as additional treatment option for malignant gliomas. However, damage not only to tumour tissue but also to normal brain has been demonstrated. The mechanisms of this unwanted side effect have not yet been clearly identified. Spreading of photosensitiser with oedema after disruption of the blood-brain-barrier and potential sensitisation of normal tissue has been found previously. The present study investigates the time- and dose-dependency of normal tissue damage to photodynamic therapy using Photofrin II after disruption of the blood-brain-barrier. METHODS: Male wistar rats anaesthetised with chloral hydrate were subjected to focal, cerebral cold lesions. Simultaneously, Photofrin II (PFII) was injected (2,5 or 5 mg/kg b.w.). Laser irradiation (630 nm) was performed after 4 h, 12 h and 24 h with varying light doses. Control groups were subjected to focal cold lesion alone, cold lesion with laser irradiation, PFII followed by laser irradiation, or laser irradiation alone (n=6 all groups). 24 h later, brains were removed for assessment of necrosis in coronal sections. FINDINGS: Light dose had a significant impact on the extent of necrosis. Compared to control animals (lesion only: 0.84 +/- 0.2 mm2; lesion and irradiation alone: 0.7 +/- 0.3 mm2), the area of necrosis was increased to 2.8 +/- 0.5 (50 J/cm2), 3.5 +/- 1,1 (100 J/cm2) and 4.3 +/- 0.7 mm2 (200 J/cm2, 5 mg/kg b.w.; p<0.01). This effect was time-dependent. Maximal necrosis (6.3 +/- 1,6 mm2) was observed when brains were irradiated 12 h after PFII injection, with less necrosis occurring at 24 h (2.8 +/- 0.4 mm2, p<0.01). Reducing sensitiser dose to 2.5 mg/kg b.w. resulted in a reduction of necrosis (2.09 +/- 0.2 mm2, p<0.05). INTERPRETATIONS: Damage to oedematous tissue after photodynamic therapy using i.v. PFII and laser light at 630 nm depends on laser dose, sensitiser dose and the time point of laser irradiation. The time point of PDT should be considered to prevent unwanted tissue reactions. In the clinical setting however, defined damage to peritumoural tissue may be advantageous. This should be achievable by optimised timing and dosage of photodynamic therapy.

Animals↗
PubMed2000

Subsidence resulting from simulated postoperative neck movements: an in vitro investigation with a new cervical fusion cage.

STUDY DESIGN: A biomechanical in vitro subsidence test of different cervical interbody fusion devices was performed using a new testing protocol that simulates physiologic conditions. OBJECTIVES: To investigate the effect of simulated postoperative neck movements on the subsidence of the new WING cervical interbody fusion cage in comparison with two other cages and bone cement. SUMMARY OF BACKGROUND DATA: Cervical interbody fusion cages sometimes cause complications because of subsidence into the adjacent vertebrae with collapse of the intervertebral space. Complications such as cage dislocation or nonunion with instability also have been reported. To prevent such complications, the new WING cervical interbody fusion cage (Medinorm AG, Quierschied, Germany) has been developed. Its area of contact with the adjacent vertebrae is supposed to be large enough to resist excessive subsidence and small enough to prevent stress protection of the tissue growing in the cage. METHODS: In this study, 24 human cervical spine specimens were tested after stabilization with either a WING, BAK/C, AcroMed I/F cage or bone cement. Then, in a new testing protocol, 700 pure-moment loading cycles (+/-2 Nm) were applied in randomized directions (lateral bending, flexion-extension, and axial rotation alone or in combination with each other) to simulate the patient's neck movements during the first few postoperative days. Measurements of the subsidence depth (total height loss) in combination with flexibility tests (+/-2.5 Nm) were performed before cyclic loading and after 50, 100, 200, 300, 500, and 700 loading cycles. RESULTS: Cyclic loading caused subsidence in all four device groups, most distinct with BAK/C-cages (1.63 mm after 700 loading cycles) followed by the new WING (0.90 mm) and the AcroMed (0.82 mm) cages. No statistically significant difference could be found among the three cage designs. However, all three cage types showed a significantly higher subsidence depth than bone cement (0.48 mm;P = 0.023 between each of the three cage-types and bone cement). A moderate correlation between bone mineral density and subsidence depth could be found only in the BAK/C group (r2 = 0.495). A large subsidence depth after 700 loading cycles was associated with a large flexibility increase in the WING (r2 = 0.786) and AcroMed groups (r2 = 0.21), but with a small flexibility increase in the BAK/C group (r2 = 0.58). CONCLUSIONS: Postoperative neck movements caused subsidence in all cervical interbody implant types. The new WING cage and the AcroMed cage seemed to have a better resistance against subsidence than the BAK/C cage. However, all three cage types had a significantly higher subsidence tendency than bone cement.

Bone Cements↗
PubMed2000

Fluorescence-guided resection of glioblastoma multiforme by using 5-aminolevulinic acid-induced porphyrins: a prospective study in 52 consecutive patients.

OBJECT: It has been established that 5-aminolevulinic acid (5-ALA) induces the accumulation of fluorescent porphyrins in glioblastoma multiforme (GBM), a phenomenon potentially exploitable to guide tumor resection. In this study the authors analyze the influence of fluorescence-guided resection on postoperative magnetic resonance (MR) imaging and survival in a series of patients who underwent surgery in the authors' department. METHODS: Fifty-two consecutive patients with GBM received oral doses of 5-ALA (20 mg/kg body weight) 3 hours before induction of anesthesia. Intraoperatively, tumor fluorescence was visualized using a modified operating microscope. Fluorescing tissue was removed whenever it was considered safely possible. Residual enhancement on early postoperative MR imaging was quantified and related to each patient's characteristics to determine which factors influenced resection. Survival was analyzed using the Kaplan-Meier method and multivariate analysis was performed in which the Karnofsky Performance Scale (KPS) score, residual fluorescence, patient age, and residual enhancement on MR images were considered. Intraoperatively, two fluorescence qualities were perceived: solid fluorescence generally reflected coalescent tumor, whereas vague fluorescence mostly corresponded to infiltrative tumor. Complete resection of contrast-enhancing tumor was accomplished in 33 patients (63%). Residual intraoperative tissue fluorescence left unresected for safety reasons predicted residual enhancement on MR images in 18 of the 19 remaining patients. Age, residual solid fluorescence, and absence of contrast enhancement in MR imaging were independent explanatory factors for survival, whereas the KPS score was significant only in univariate analysis. No perioperative deaths and one case of permanent morbidity were encountered. CONCLUSIONS: The observations in this study indicate the usefulness of 5-ALA-induced tumor fluorescence for guiding tumor resection. The completeness of resection, as determined intraoperatively from residual tissue fluorescence, was related to postoperative MR imaging findings and to survival in patients suffering from GBM.

Adult↗
PubMed1998

Intraoperative detection of malignant gliomas by 5-aminolevulinic acid-induced porphyrin fluorescence.

OBJECTIVE: Survival after surgery and radiotherapy for the treatment of malignant gliomas is linked to the completeness of tumor removal. Therefore, methods that permit intraoperative identification of residual tumor tissue may be of benefit. In a preliminary investigation, we have studied the value of fluorescent porphyrins that accumulate in malignant tissue after administration of a precursor (5-aminolevulinic acid) for labeling of malignant gliomas in nine patients. METHODS: Three hours before the induction of anesthesia, 10 mg 5-aminolevulinic acid/kg body weight was administered orally. Intraoperatively, red porphyrin fluorescence was observed with a 455-nm long-pass filter after excitation with violet-blue (375-440 nm) xenon light and was verified by analysis of fluorescence spectra. Fluorescing and nonfluorescing samples taken from the tumor perimeters were examined histologically or used to study the photobleaching of porphyrins by excitation light and white light from the operating microscope. Plasma and erythrocyte porphyrin levels were determined by fluorescence photometry. RESULTS: Normal brain tissue revealed no porphyrin fluorescence, whereas tumor tissue was distinguished by bright red fluorescence. For a total of 89 tissue biopsies, sensitivity was 85% and specificity was 100% for the detection of malignant tissue. For seven of nine patients, visible porphyrin fluorescence led to further resection of the tumor. Under operating light conditions, fluorescence decayed to 36% in 25 minutes for violet-blue light and in 87 minutes for white light. Plasma and erythrocyte porphyrin contents increased slightly, without exceeding normal levels. CONCLUSION: Our observations suggest that 5-aminolevulinic acid-induced porphyrin fluorescence may label malignant gliomas safely and accurately enough to enhance the completeness of tumor removal.

Aged↗
PubMed1997

Accuracy of the clinical diagnosis of corticobasal degeneration: a clinicopathologic study.

The accuracy of the clinical diagnosis of corticobasal degeneration (CBD) is unknown. To determine its diagnostic accuracy, we presented 105 cases with known neuropathologic diagnoses, including CBD (n = 10), progressive supranuclear palsy (PSP, n = 24), Parkinson's disease (n = 15), diffuse Lewy body disease (n = 14), multiple system atrophy (n = 16), postencephalitic parkinsonism (n = 7), Pick's disease (n = 7), Creutzfeldt-Jakob disease (n = 4), Alzheimer's disease (n = 4), vascular parkinsonism (n = 3), and Whipple's disease (n = 1), as clinical vignettes to six neurologists unaware of the autopsy findings. Reliability was measured with the kappa statistics. The neurologists' clinical diagnoses were compared with clinicopathologic diagnoses for sensitivity, specificity, and positive predictive values at first and last clinic visits. The group reliability for the diagnosis of CBD significantly improved from moderate for the first visit (mean = 34 months after onset) to substantial for the last (68 months after onset). For the first visit, mean sensitivity for CBD was low (35%), but specificity was near-perfect (99.6%). For the last visit, mean sensitivity minimally increased (48.3%), and specificity remained stable. False-negative misdiagnoses mainly occurred with PSP. False-positive diagnoses were rare. The extremely low sensitivity of the clinical diagnosis of CBD suggests that this disorder is markedly underdiagnosed. Although the validity of the clinical diagnosis might have been improved if neurologists could have examined these patients, more important is that this disorder was misdiagnosed by the primary neurologists. In our data set, the best predictors for the diagnosis of CBD included limb dystonia, ideomotor apraxia, myoclonus, and asymmetric akinetic-rigid syndrome with late onset of gait or balance disturbances.

Basal Ganglia↗
PubMed1996

Neuropsychological deficits in patients with Sneddon's syndrome.

The results of a neurological, neuropsychological and MRI study of the brain in 21 patients (aged 18-59 years) with Sneddon's syndrome are reported. The predominant findings were marked neuropsychological deficits in two-thirds of the patients. While sensorimotor deficits after stroke in these patients had a good prognosis, neuropsychological deficits persisted. Of the 21 patients, 14 were incapable of gainful employment, 10 because of severe cognitive dysfunction.

Adult↗
PubMed1996

Pediatric clozapine intoxication.

Clozapine is a tricyclic dibenzodiazepine derivative used as an antipsychotic in adults. Clozapine's safety in children has not been established. This report describes three unintentional clozapine ingestions in pediatric patients. These are the first reported cases of clozapine intoxication in children. All three patients demonstrated dramatic alterations in mental status and tone, and two demonstrated extrapyramidal effects. Serum clozapine levels obtained in two patients were within the average range of steady state plasma concentrations for adults. These cases show the dramatic presentations of pediatric ingestion of clozapine and the differences between adult and pediatric intoxications.

Antidepressive Agents, Tricyclic↗
PubMed1996

Photodynamic therapy within edematous brain tissue: considerations on sensitizer dose and time point of laser irradiation.

Photosensitizer is known to spread with vasogenic edema fluid arising from a cerebral lesion (Neurosurg 33:1075-1082, 1993), which may be essential for sensitizing malignant cells outside the main tumor mass. The present experiments seek to elucidate whether resultant necrosis of perifocal brain tissue after laser irradiation follows a corresponding time pattern and whether damage depends on the photosensitizer dose. Male Wistar rats were anaesthetized with chloralhydrate for venous cannulation, craniotomy and focal cold lesion in order to induce vasogenic edema. Simultaneously, Photofrin II (PF II) was administered at a dose of 5 mg kg-1. The animals were re-anaesthetized after either 4, 12 or 24 h for the irradiation of lesion and perifocal tissue with 200 J cm-2 of laser light (630 nm). The brains of other animals were irradiated 4 h after cold lesion with 200 J cm-2 after receiving either 0, 2.5 or 5 mg kg-1 PF II (all groups: n = 6). Resultant necrosis was assessed planimetrically in serial coronal cryosections of brains perfusion fixed 24 h after irradiation. Necrosis was significantly enhanced with irradiation 4 h after cold lesion and photosensitizer (avg. area +/- SD: 4.3 +/- 0.7 mm2) compared with lesion only (0.84 +/- 0.2 mm2). Maximal necrosis (6.3 +/- 1.6 mm2) occurred with irradiation 12 h after lesion, whereas necrosis was only slightly increased with irradiation at 24 h (2.8 +/- 0.4 mm2). Furthermore, the area of necrosis was dependent on the sensitizer dose (0 mg kg-1: 0.7 +/- 0.3 mm2, 2.5 mg kg-1: 2.09 +/- 0.2 mm2, 5 mg kg-1: 4.3 +/- 0.7 mm2; all differences p < 0.05). Therefore, to prevent unwanted side-effects such as necrosis of edematous but otherwise healthy, peritumoral tissue in the treatment of malignant cerebral tumors by PDT, tribute should be paid to the possibility of time and dose dependent sensitization of the perifocal tissue after i.v. administration of photosensitizer.

Animals↗
PubMed1996

Accuracy of clinical criteria for the diagnosis of progressive supranuclear palsy (Steele-Richardson-Olszewski syndrome).

We assessed the validity and interrater reliability of neurologists who, using four different sets of previously published criteria for the clinical diagnosis of progressive supranuclear palsy (PSP), also called Steele-Richardson-Olszewski syndrome, rated 105 autopsy-proven cases of PSP (n = 24), Lewy body disease (n = 29), corticobasal ganglionic degeneration (n = 10), postencephalitic parkinsonism (n = 7), multiple system atrophy (n = 16), Pick's disease (n = 7), and other parkinsonian or dementia disorders (n = 12). Cases were presented in random order to six neurologists. Information from each patient's first and last visits to the medical center supplying the case was presented sequentially to the rater, and the rater's diagnosis was compared with the neuropathologic diagnosis of each case. Interrater agreement for the diagnosis of PSP varied from substantial to near perfect, but none of the criteria had both high sensitivity and high predictive value. Because of these limitations, we used a logistic regression analysis to identify the variables from the data set that would best predict the diagnosis. This analysis identified vertical supranuclear palsy with downward gaze abnormalities and postural instability with unexplained falls as the best features for predicting the diagnosis. From the results of the regression analysis and the addition of exclusionary features, we propose optimal criteria for the clinical diagnosis of PSP.

Aged↗
PubMed1995

Pramipexole in patients with early Parkinson's disease.

We evaluated the efficacy, safety, tolerability, and pharmacokinetics of pramipexole, a novel dopamine D2 receptor agonist, in early Parkinson's disease (PD). The study design was a parallel, placebo-controlled trial using an ascending dose of 4.5 mg/day pramipexole maximum. All subjects received selegiline (10 mg/day) but were not treated with levodopa. Of the 55 subjects who received at least one dose of the study medication, all but one, in the placebo group, completed the trial, which was 9 weeks in duration. The primary efficacy endpoints were changes in scores from baseline to final measurement on the Unified Parkinson's Disease Rating Scale (UPDRS) Parts II and III. The pramipexole group had a significantly greater improvement (p = 0.002) than the placebo group on UPDRS Part II (Activities of Daily Living). The change in score from baseline to final measurement on UPDRS Part III (Motor Examination) was not significantly different (p = 0.10) between the pramipexole and placebo groups, although the trend favoured the pramipexole group. All subjects in both the pramipexole and the placebo groups experienced one or more episodes of asymptomatic orthostatic hypotension; there was no significant difference between the pramipexole and the placebo groups in the number of subjects experiencing symptomatic orthostatic hypotension. The adverse events profile of pramipexole was similar, in general, to that of other dopamine receptor agonists. Plasma pramipexole levels increased linearly with dose. Pramipexole appears to be promising agent in the treatment of early PD.

Adult↗
PubMed1995

The effect of hypertonic fluid resuscitation on brain edema in rabbits subjected to brain injury and hemorrhagic shock.

Small-volume resuscitation with 7.2% NaCl/10% dextran 60 (HHS) restores cardiovascular stability faster than all other therapeutic modalities currently known. This study was undertaken to elucidate the effects of HHS on the brain, specifically on the formation of posttraumatic brain edema. HHS was administered to anesthetized albino rabbits with or without a focal cryogenic brain lesion and hemorrhagic shock. Specific gravity of small tissue samples was determined 4 h after injury and values were topographically assembled to form a color-coded map of both hemispheres, allowing for a high resolution mapping of brain edema. Cerebral blood flow on the side of the lesion, as assessed by the H2 clearance method, increased transiently after injury but remained unchanged from baseline during shock and after infusion of HHS, indicating intact cerebrovascular autoregulation. The cryogenic lesion without subsequent HHS infusion resulted in significant brain edema formation in grey and white matter of the exposed hemisphere. In injured animals, resuscitation with HHS led to a global reduction of brain water content in both hemispheres. We conclude that small-volume resuscitation with HHS does not worsen posttraumatic brain edema. To the contrary, our results show that it decreases cerebral water content even in regions close to the injury. This makes it worthwhile to investigate the benefits of HHS for the treatment of intracranial hypertension.

Animals↗
PubMed1993

Renal complications of infected ventriculoatrial shunts.

Contamination of a ventriculoatrial shunt (VAS) with skin organisms that are usually nonpathogenic may be followed by an immunologically mediated renal injury. The bacteria characteristically involved are coagulase-negative Staphylococci (e.g., Staphylococcus epidermidis), which strongly adhere to the plastic surface of the VAS. These bacteria are protected from the body's natural defense mechanisms and respond only poorly to antibiotics. As a result, their growth persists and produces a continuous antigenic stimulation. Circulating immune complexes (CIC) are an appropriate tool to screen for chronically infected VASs. We followed CIC in 138 VAS patients. An infected VAS was seen in 20 of the 24 patients with highly elevated CIC and in 1 of the 19 patients with moderately elevated CIC, but none of the 95 patients with normal CIC had evidence of shunt infection. Of the 21 patients with shunt infections, 8 had renal involvement (4 requiring dialysis, and 4 with proteinuria, hematuria, and/or elevated creatinine). Results from kidney biopsy specimens available from 4 patients confirmed glomerulonephritis. Of the 4 patients requiring dialysis at diagnosis, renal function recovered sufficiently to stop dialysis after successful VAS exchange in all but 1. In the other 4 patients, renal symptoms (proteinuria, creatinine) also improved after VAS revision. Chronic infection with S. epidermidis or other bacteria is a continuing problem in patients with VASs and can lead to an immune-mediated renal injury. However, the prognosis for reversal of the renal injury is relatively good if the VAS infection is treated promptly.

Adolescent↗
PubMed1991

[Hardware for graphics systems].

In all personal computer applications, be it for private or professional use, the decision of which "brand" of computer to buy is of central importance. In the USA Apple computers are mainly used in universities, while in Europe computers of the so-called "industry standard" by IBM (or clones thereof) have been increasingly used for many years. Independently of any brand name considerations, the computer components purchased must meet the current (and projected) needs of the user. Graphic capabilities and standards, processor speed, the use of co-processors, as well as input and output devices such as "mouse", printers and scanners are discussed. This overview is meant to serve as a decision aid. Potential users are given a short but detailed summary of current technical features.

Computer Graphics↗
PubMed1990

A comparative analysis of THAM (Tris-buffer) in traumatic brain oedema.

The effect of THAM on brain oedema parameters was initially investigated in animals with cold brain lesions; THAM was then used in head injury patients, ICP, SAP and CPP were analyzed. In the experiments with rats after freezing lesion, THAM was compared to equivalent doses of Na-bicarbonate. The animals were artificially respirated and sacrificed 6 h after trauma. THAM did significantly reduce water (wet-dry weight technique) and sodium contents in both hemispheres, whereas bicarbonate was ineffective. The potassium contents were even preserved at almost normal levels. In 80 patients receiving alternatively THAM (18-36 g/100-200 ml/1-2h), mannitol (20%, 125-250 ml/20-40 min) or sorbitol (40%, 70-140 ml/20-40 min), the ICP rapidly decreased following THAM infusion. The maximal fall in ICP (33%) was equal to that with mannitol and sorbitol. The slope of ICP decrease was equal with THAM and Mannitol but steeper with sorbitol. With THAM, however, the effect on ICP lasts longer than with osmotherapy. The EEG improved more rapidly after THAM. As shown by blood plasma values, the action of THAM is not based on osmotic effects. The increases in pH and especially in base excess suggest an intracerebral buffering. The encouraging results with THAM require a randomized clinical trial after severe head injury which is presently prepared.

Adolescent↗
PubMed1990

[The foramen of Monro--blockage caused by a giant aneurysm of the basilar artery. A case report and review of the literature].

A case of a giant aneurysma of the basilar artery bifurcation with occlusive hydrocephalus due to bilateral foramen of Monro occlusion is reported. The patient presented with progressive neurological deterioration which led to computerized tomography examination and implantation of a ventricular shunt as an emergency procedure. After the patient had recovered to a certain extent, four-vessel angiography was performed that demonstrated a giant basilar tip aneurysm. As the posterior communicating, the posterior cerebral as well as the superior cerebellar arteries originated from the aneurysm sac direct surgical attack as well as endovascular treatment was considered to be impossible. A permanent biventricular-abdominal shunt system was implanted and the patient was discharged. Three weeks later the patient was readmitted comatose after he had suffered a massive subarachnoid hemorrhage from which he finally died. The clinical and radiological signs, the differential-diagnostic considerations as well as the few cases of foramen of Monro occlusion by a giant basilar artery tip aneurysm, presented in the literature so far, are discussed.

Basilar Artery↗