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Biomedical subjects

B Turowski

Publications and source records attributed to B Turowski.

At least 19 recordsLinked to original sources
PubMed2006

New angiographic measurement tool for analysis of small cerebral vessels: application to a subarachnoid haemorrhage model in the rat.

INTRODUCTION: Exact quantification of vasospasm by angiography is known to be difficult especially in small vessels. The purpose of the study was to develop a new method for computerized analysis of small arteries and to demonstrate feasibility on cerebral angiographies of rats acquired on a clinical angiography unit. METHODS: A new software tool analysing grey values and subtracting background noise was validated on a vessel model. It was tested in practice in animals with subarachnoid haemorrhage (SAH). A total of 28 rats were divided into four groups: SAH untreated, SAH treated with local calcium antagonist, SAH treated with placebo, and sham-operated. The diameters of segments of the internal carotid, caudal cerebral, middle cerebral, rostral cerebral and the stapedial arteries were measured and compared to direct measurements of the diameters on magnified images. RESULTS: There was a direct correlation between the cross-sectional area of vessels measured in a phantom and the measurements acquired using the new image analysis method. The spread of repeated measurements with the new software was small compared to the spread of direct measurements of vessel diameters on magnified images. Application of the measurement tool to experimental SAH in rats showed a statistically significant reduction of vasospasm in the SAH groups treated with nimodipine-releasing pellets in comparison to all the other groups combined. CONCLUSION: The presented computerized method for analysis of small intracranial vessels is a new method allowing precise relative measurements. Nimodipine-releasing subarachnoidal pellets reduce vasospasm, but further testing with larger numbers is necessary. The tool can be applied to human angiography without modification and offers the promise of substantial progress in the diagnosis of vasospasm after SAH.

Animals↗
PubMed2006

[Pre- and postnatal MRI of the fetus with complex intracranial vascular malformation].

Intracranial vascular malformations (IVM) on the whole occur in neonates very rarely. In such cases of IVM two different kinds can and must be discerned: (1) dural arteriovenous shunts (DAVS) and (2) vein of Galen aneurysmal malformations (VGAM). The latter seem to represent the majority of IVM of newborns. Several classifications are known for both types. Mortality of neonates and babies due to DAVS exceeds the average mortality from DAVS in adults. VGAM and DAVS can be diagnosed by prenatal ultrasonography only when the vessels behind the shunt are vasodilated because of the increasing flow stress. For that reason VGAM and DAVS are generally not recognized before the last trimenon or even postnatally. The prognosis of an IVM is influenced by the shunt capacity and its resulting cardiac stress as well as by the child's age. To plan the mostly interventional therapy, postnatal angiography (DSA) and MRI are employed and to an increasing extent also prenatal MRI examinations. We describe the case of a very complex IVM, the full dimensions of which could only be discerned by using pre- and postnatal MRI supplementary to the ultrasonography. Besides DAVS, flows from the pericallosal arteries as well as from the thalamic branches had to be considered. As a consequence DAVS and in addition VGAM existed in parallel.

Central Nervous System Vascular Malformations↗
PubMed2006

[Clinical and histopathological results after local chemoembolization of oral and oropharyngeal carcinoma--comparison with intraarterial chemoperfusion].

PURPOSE: Retrospective analysis of clinical and histopathological results after neoadjuvant intraarterial chemoembolization (iaCE) as compared to intraarterial chemoperfusion (iaCP) in patients with oral and oropharyngeal squamous cell cancer (SCC). MATERIALS AND METHODS: 289 patients (mean age 60 years, 68 % male) with SCC of the oral cavity or the oropharynx (WHO stage I-IV) received (1) neoadjuvant iaCE (n = 103) with a crystalline suspension of cisplatin (150 mg/m(2), solution ratio 5 mg cisplatin ad 1 ml NaCl 0.9 %, total volume 40 - 60 ml) or (2) iaCP (n = 186) using high-dose cisplatin infusions (150 mg/m(2), 1 mg cisplatin ad 1 ml NaCl 0.9 %, 400 - 500 ml). The decision for iaCE or iaCP was made individually for each patient based on tumor localization and expected vascular supply. Four weeks after local chemotherapy, the treatment response was evaluated according (1) to WHO criteria and (2) to histopathological TNM-grading after tumor resection. RESULTS: The overall treatment response was 72.5 % after iaCE and 47 % after iaCP (p < 0.001). A stable disease was found in 24 % and 48 %, respectively, and tumor progression was found in 3 % for both modalities. Histopathological examination of resected tumors revealed complete remission in 20 % after iaCE and 13 % after iaCP. The percentage of complete remissions was highest in local T1 and T2 tumors after iaCE (42.9 versus 22.4 % after iaCP, p = 0.031). Local side effects were significantly more frequent after iaCE than after iaCP (p < 0.001), especially in obese patients with extended carcinoma of the oral floor or the tongue base. CONCLUSION: Compared to iaCP, clinical and histopathological remission rates are significantly higher after iaCE, especially in early stages of local tumor growth. However, in view of the higher risk of regional complications, indication for iaCE should be considered cautiously and its application should be limited to small tumors of the oral floor and the oral tongue.

Antineoplastic Agents↗
PubMed2005

Assessment of changes in cerebral circulation time due to vasospasm in a specific arterial territory: effect of angioplasty.

This study demonstrates that in experienced hands, intracranial angioplasty is a feasible and safe option in a selected group of patients with severe (>50% stenosis) symptomatic vasospasm following subarachnoid hemorrhage. Cerebral circulation time is a surrogate parameter closely linked to cerebral perfusion. The study presented shows that not only stenosis but also changes in circulation time are obtained by angioplasty. Twenty angioplasties of one or two vessel segments were performed over 2 years in 18 consecutive patients with posthemorrhagic vasospasm fulfilling criteria for invasive treatment. In all patients, degree of stenosis and circulation time could be reduced by angioplasty. Clinical results were ranked according to Glasgow Outcome Scale. Imaging after 15/20 angioplasties showed no additional infarction. In 4/20 cases, CT showed demarcation of infarction after angioplasty. In 1/20 cases of posterior circulation angioplasty, CT is not sensitive enough to exclude smaller infarctions. Imaging and clinical outcome reveal a definite benefit.

Adolescent↗
PubMed2005

[Local chemotherapy for squamous cell cancer of the oral cavity and oropharynx].

BACKGROUND: Modern treatment concepts for patients suffering from oral and oropharyngeal cancer include more and more adjuvant therapeutic options. Local chemotherapy offers the possibility to apply an extremely high drug concentration at the tumor site while minimizing possible side effects by systemic neutralization at the same time. PATIENTS AND METHODS: A total of 289 patients with histologically proven carcinoma of the oral cavity and the oropharynx underwent neoadjuvant intra-arterial chemotherapy with high-dosage cisplatin within a multimodal therapeutic setting. Concerning the TNM classification, more than 70% of the patients were classified as stages III and IV. The mean age at the time of intervention was 60 years, and 71% of the patients were male. RESULTS: After the first cycle 19.3% of the patients presented with complete remission (grade I); 35.4% and 41.5% showed partial remissions (grade II) or stable disease (grade III), respectively. The mean observation time after treatment was 28 months (median: 24.2 months). Of the 137 patients who completed the full multimodal therapeutic scheme, 11% developed local recurrence, and 12.4% developed lymph node or distant metastasis. At the time of evaluation, 72.5% of these patients were still alive. CONCLUSION: Intra-arterial chemotherapy is a safe and highly effective procedure that should be considered as an important option in multimodal therapeutic concepts for oral and oropharyngeal cancer.

Adult↗
PubMed2005

Asymptomatic aneurysm of the subclavian vein.

Venous aneurysms are rare entities whose etiology remains unknown. We report an incidental observation of an asymptomatic, saccular aneurysm of the subclavian vein and discuss the possible origin and clinical impact, with special remarks on venous interventions.

Adult↗
PubMed2005

Intra-arterial high-dose chemotherapy with cisplatin as part of a palliative treatment concept in oral cancer.

BACKGROUND AND PURPOSE: Patients with cancer of the oral cavity often present with advanced tumor stages, distant metastasis, or severe comorbidities, which render radical surgery unfeasible. The purpose of this study was to investigate the response rate, technical feasibility, and safety of intra-arterial (IA) chemotherapy as palliative treatment in this situation. METHODS: From November 1997 to December 2003, 64 patients with histologically proven oral squamous cell carcinoma, classified as inoperable, received IA high-dose chemotherapy with cisplatin as a palliative treatment at our institution. To minimize toxic side effects, sodium thiosulfate was given intravenously. Twenty-eight percent of the patients were female; average age was 61.5 years. Clinical staging of primary tumors was TNM (tumor, nodules, metastases) stage IV in 89%, stage III in 6.3% and stage II in 4.7%. After local chemotherapy, additional radiation of the tumor area or radiochemotherapy was performed in 33 patients. RESULTS: There were no major catheter-related complications or severe side effects of IA chemotherapy. After the first cycle, 10% percent of the patients had complete remission (CR), 35% had partial response (PR), and 43.3% presented with stable disease. Mean follow-up interval was 11 +/- 12.9 months. Forty-five patients died after a mean period of 7.6 +/- 7.0 months (median, 5.1 months). The overall 1- and 2-year survival rates were 29.5% and 18%, respectively. There was a trend toward longer survival in patients who received subsequent radiation or radiochemotherapy after IA chemotherapy. CONCLUSION: IA chemotherapy in patients with inoperable carcinoma of the oral cavity as palliative treatment was technically feasible and safe. The overall response rate after IA chemotherapy was 45% (CR 10%; PR 35%). Side effects could be minimized by neutralizing the cytotoxic agent by sodium thiosulfate.

Adult↗
PubMed2003

Pre- and posttreatment MR imaging in AIDS-related Kaposi sarcoma of the conjunctiva and lacrimal gland.

AIDS-related Kaposi sarcoma can affect the eye: the (bulbar) conjunctiva and lacrimal gland being rare sites of occurrence. We present a case of AIDS-related Kaposi sarcoma of the conjunctiva in which MR imaging was effective in suggesting the diagnosis and aiding therapeutic strategy. We also discuss advances in imaging of ocular and orbital malignancies presented in the recent literature.

AIDS-Related Opportunistic Infections↗
PubMed2002

Spinal subdural haematoma mimicking tethered cord after posterior fossa open surgery.

We report the MRI findings in a girl aged 3 years and 10 months who developed a spinal subdural haematoma after posterior fossa open surgery for cerebellar malignant rhabdoid tumour. Emergency surgery was performed immediately because of increased intracranial pressure. Control MRI 48 h after surgery showed a spinal subdural haematoma without clinical signs of paresis or bladder dysfunction. Spinal subdural haematoma is rare, and only few cases have been reported, especially in children. This report suggests that "silent" (without clinical symptoms) postoperative spinal acute subdural haemorrhage can occur after posterior fossa surgery.

Cerebellar Neoplasms↗
PubMed2002

Toxicological studies of doxorubicin bound to polysorbate 80-coated poly(butyl cyanoacrylate) nanoparticles in healthy rats and rats with intracranial glioblastoma.

Polysorbate 80-coated poly(butyl cyanoacrylate) nanoparticles (NP) were shown to enable the transport of a number of drugs including the anti-tumour antibiotic doxorubicin (DOX) across the blood-brain barrier (BBB) to the brain after intravenous administration and to considerably reduce the growth of brain tumours in rats. The objective of the present study was to evaluate the acute toxicity of DOX associated with polysorbate 80-coated NP in healthy rats and to establish a therapeutic dose range for this formulation in rats with intracranially implanted 101/8 glioblastoma. Single intravenous administration of empty poly(butyl cyanoacrylate) NP in the dose range 100-400 mg/kg did not cause mortality within the period of observation. NP also did not affect body weight or weight of internal organs. Association of DOX with poly(butyl cyanoacrylate) NP did not produce significant changes of quantitative parameters of acute toxicity of the anti-tumour agent. Likewise, the presence of polysorbate 80 in the formulations was not associated with changes in toxicity compared with free or nanoparticulate drug. Dose regimen of 3x1.5 mg/kg on days 2, 5, 8 after tumour implantation did not cause drug-induced mortality. The results in tumour-bearing rats were similar to those in healthy rats. These results demonstrate that the toxicity of DOX bound to NP was similar or even lower than that of free DOX.

Animals↗
PubMed2002

Proton MR spectroscopy of neurometabolites in hepatic encephalopathy during L-ornithine-L-aspartate treatment--results of a pilot study.

Hepatic encephalopathy (HE) is associated with typical changes in neurometabolites most likely being caused by an elevated systemic ammonia level. Blood ammonia is a valid over-all biomarker of HE and thus is regularly determined in clinical trials. The neurometabolites affected in HE can be assessed in vivo by proton magnetic spectroscopy. The aim of this study was to show the effect of the ammonia lowering drug L-ornithine-L-aspartate (OA) on the cerebral glutamate+glutamine/creatine (Glu+GLN/Cr) ratio. In an open clinical trial (pilot study), 15 patients with stable HE were treated with an infusion of 40 g OA over 8 h (5 g/h). Immediately before and 6-8 (mean 6.8) h after start of the infusion, spectroscopy of the parietal white matter was performed and arterial blood ammonia quantified. Glu+GLN/Cr-ratios correlated significantly with ammonia data (Spearman's correlation coefficient rs = 0.72, p < 0.001). Likewise, the OA induced changes (versus baseline before infusion) in blood ammonia level and in Glu+GLN/Cr-ratios correlated significantly rs = 0.54, p = 0.0375). Magnetic resonance (MR) spectroscopy assesses the neurometabolite variation present in HE. OA induced changes in cerebral Glu+GLN/ Cr-ratio were significantly correlated with the drug effects on arterial blood ammonia. These pilot data indicate that MR spectroscopy detects a specific biomarker of HE that may reflect the extent of the cerebral alterations associated with the disease.

Aged↗
PubMed2001

Endovascular treatment of symptomatic carotid stenosis using stent placement: long-term follow-up of patients with a balanced surgical risk/benefit ratio.

BACKGROUND AND PURPOSE: Carotid endarterectomy (CEA) is not necessarily beneficial in all patients with symptomatic high-grade (>/=70%) internal carotid artery (ICA) stenosis. Independent risk factors modulate both the individual stroke risk under medical treatment and the combined stroke and death risk after CEA. Endovascular stenting of symptomatic ICA stenosis may be an alternative to CEA in patients with a balanced surgical risk/benefit ratio. METHODS: We included 43 patients (71% men; median age, 67 years) with a recently symptomatic ICA stenosis with >/=70% luminal narrowing in whom the individual sum of medical and surgical risk factors suggested a balanced surgical risk/benefit ratio (risk-modeling appraisal derived from the European Carotid Surgery Trial). After stenting of the stenosed ICA with distal balloon protection, the mean+/-SD follow-up, including clinical and ultrasonographic examinations, was 20+/-11.8 months, with a median number of examinations of 5 per patient. RESULTS: Recanalization of ICA stenoses was technically successful in 40 of 43 procedures (93%). Within the 30-day postinterventional period 1 death occurred (2.5%), and the combined stroke and death rate within follow-up was 5%. Except for 1 asymptomatic ICA occlusion, no restenosis >/=70% occurred during follow-up. CONCLUSIONS: ICA stenting in symptomatic patients with a balanced surgical risk/benefit ratio is technically feasible, with a low periprocedural risk of stroke or death. Furthermore, the risk of future stroke and rate of significant restenosis during long-term follow-up appears to be low, suggesting that ICA stenting may be useful in carotid revascularization and stroke prevention.

Aged↗
PubMed2001

Cutaneous emphysema and craniocervical bone pneumatization.

We report a case of pneumatization of the upper cervical spine and the craniocervical junction, including the occipital bone, accompanied by extensive soft tissue emphysema. There was no history of trauma or surgery. Follow-up X-ray and CT demonstrated the development of those changes. A combination of a developmental abnormality and the unusual habit of frequent Valsalva's maneuvers may have led to those findings. Clinical consequences will be discussed.

Adult↗
PubMed1999

Opportunistic CNS infection after bone marrow transplantation.

We retrospectively identified opportunistic CNS infections in 655 patients who had undergone allogeneic, syngeneic or autologous BMT or PBSCT between 1990 and 1997. Twenty-seven patients (4%) developed CNS infections. All CNS infections occurred in allogeneic BMT or PBSCT patients. The most common CNS infections were toxoplasma encephalitis (74%) and cerebral aspergillosis (18%). Furthermore, we identified one patient with candida encephalitis and one patient with viral encephalitis. Overall mortality of patients with opportunistic CNS infection was 67%. There were two different groups of toxoplasma encephalitis with a different appearance on MR imaging. The first group showed edema, but no gadolinium enhancement, whereas the second group exhibited typical MRI appearances with the exception of frequent hemorrhagic transformation. The first group had a significant shorter latency between BMT and onset of CNS infection (mean 45 days vs 180 days, P = 0.02), a significant higher daily dose of corticosteroids as treatment for graft-versus-host disease (GVHD) (P = 0.01), more severe GVHD and a higher mortality (71% vs 36%). This study shows that the most common CNS infections in our patient population are toxoplasma encephalitis and cerebral aspergillosis, that there are two distinct subgroups of toxoplasma encephalitis and that CNS infections occur after allogeneic BMT only.

Adolescent↗
PubMed1999

Intraarterial chemotherapy as neoadjuvant treatment of oral cancer.

Neoadjuvant chemotherapy in patients with primary squamous cell carcinomas of the oral cavity should lead to high remission rates whilst having low morbidity. Efficacy can also be enhanced by treating small tumour stages. As part of a multi-modality therapy of all stages of primary oral cavity carcinoma, 103 patients were treated with neoadjuvant intraarterial (i.a.) chemotherapy. After regimen A with 100 mg/m2 i.a. cisplatin followed by 5 day continuous intravenous infusion of 5-fluorouracil (1 g/m2 per day) in 36 patients, an i.a. high pressure chemo-perfusion with a dose of 150 mg/m2 cisplatin was used with simultaneous intravenous infusion of 9 g/m2 sodium thiosulfate (regimen B, 67 patients). Subsequent treatment comprised radical surgery and simultaneous radiochemotherapy with docetaxel. Partial and complete remissions were found in 80.6% (regimen A) and 67.2% (regimen B) of cases, tumour growth was inhibited in 11.1% and 31.3%. Very low toxicity could be shown especially in regimen B. 66.7% and 74.6% of patients could be operated on radically. Survival rate was 61.1% (regimen A, 22.7 months of mean observation time) and 79.1% (regimen B, 8.4 months). Patients with high-grade remissions seemed to have a survival advantage. Neoadjuvant i.a. chemotherapy with cisplatin, especially in its high dose variant, is a practical therapeutic tool for the treatment of all stages of primary oral cavity carcinoma.

Antineoplastic Combined Chemotherapy Protocols↗