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Biomedical subjects

G Wurm

Publications and source records attributed to G Wurm.

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

[2-(3-Halogen-4-hydroxyphenyl)-1,4-napthoquinone derivatives from 2-(3,5-di-tert-butyl-4-hydroxyphenyl)-analogs, potent 5-lipoxygenase inhibitors. 27. 1,4-Naphthoquinones].

A new simple and fast method for the synthesis of halogenated hydroxyphenyl naphthoquinones as potential 5-lipoxygenase (LOX) inhibitors is presented. While the aryl naphthoquinone 1, a potent 5-LOX inhibitor, with AlCl3 is debutylated to 2a and 2b, the oxidized cyclohexadienylidene derivative 3 reacts comparably by concomitant halogenation to 4a and with AlBr3 to 4b, respectively. As products of a side reaction of 6 with TiCl4 and BBr3 the tetracyclic benzo[b]naphthol[2,1-d]furan derivatives 8a and 8b are isolated. Selected compounds are investigated for 5-lipoxygenase inhibiting and antioxidative properties. There is a clear-cut correlation of both qualities in those compounds with a 3-OH function and with two, one or without any tert-butyl group at the phenyl moiety. In contrast the quinone 6 (3-Cl) and the dibenzofuran 8a are powerful 5-LOX inhibitors with only low antioxidative activity.

Antioxidants↗
PubMed1998

Microsurgical management of a complicated aneurysmal endovascular embolisation with GDC coil: a case report.

We present a case involving a microsurgical approach to solving the problem of a medial cerebral artery (MCA) occlusion occurring after GDC coiling of an internal cerebral artery (ICA) bifurcation aneurysm in a 40 year old woman. We describe the clinical course of the case and discuss technical possibilities and risks of clipping a coiled aneurysm. One key to success is awareness of changes in the aneurysm's properties after coiling. With loss of elasticity the aneurysm had the effect of a tumor fixed on the vessel. The apposition of the aneurysm to the wall of the vessel, as well as the aneurysm's rigidity and increase of intracranial pressure after subarachnoideal hemorrhage (SAH), may lead to occlusion of the vessel. In cases of an mandatory operation due to the occlusion of a main arterial stem after coiling, it is primarily crucial to perforate the aneurysm's fundus, remove the coils, and, finally, to clip the slack neck of the aneurysm. An attempt to precisely prepare and clip the aneurysmal neck without removing the coils could result in the rupture of the aneurysm's neck.

Adult↗
PubMed1996

Subdural hemorrhage of the cauda equina. A rare complication of cerebrospinal fluid shunt. Case report.

We describe the case of a 16-year-old boy with idiopathic hydrocephalus, who developed cranial subdural hygromas and subsequent cranial subdural hemorrhage after a shunting procedure. Sciatica and radicular lumbar pain initially seemed to be unrelated to the proceeding implantation of a ventriculoatrial shunt. CT scan revealed a sharply demarcated hyperdensity in the lumbar subdural space with compression of the cauda equina. Differential diagnosis considerations included vascular malformations, vascular tumors, benign tumors of meninges or nerve sheets, ependymoma, lymphoma, and metastases. MR investigation did, in fact, clearly recognize this hyperintense space-occupying lesion as blood in the subdural space which outlined the cauda equina. We believe that the spinal subdural hematoma in our case represented an extension of intracranial subdural haemorrhage fluid into the spinal subdural space.

Adolescent↗
PubMed1996

Three cases of hindbrain herniation in adults with comments on some diagnostic difficulties.

In discussing the clinical features and surgical treatment of adult patients with Arnold Chiari deformity type I the authors focus on the differential diagnosis from demyelinating disease and present three illustrative cases. Out of 118 patients initially diagnosed as having demyelinating disease and admitted to our hospital between December 1991 and April 1993, three were subsequently found to have the Arnold Chiari deformity on MRI. The delay until correct diagnosis amounted to 10, 16 and 32 years, respectively. Our study stresses the diagnostic importance of MRI of the craniocervical area in cases of unexplained neurological symptoms and external signs of dysplasia. Accurate examination, early diagnosis and selection of proper surgical management can alleviate severe symptoms in many instances and prevent neurological complications.

Adolescent↗
PubMed1996

[Stereotaxically guided versus ultrasound guided surgery--a comparative report of experiences].

Localisation and approach are the keys of surgery on brain tumours. Apart from the up and coming neuronavigational devices, stereotactical and ultrasound guidance are well established methods in locating intracranial tumours and in selecting the optimal approach for resection. Nevertheless it is not clear, which guidance tool is more practicable in the daily routine. Both methods have been used in our department since 1989. During the last six and half years we have operated on 1314 patients suffering from intracranial tumours. In 148 cases we have used either stereotactical (n = 37) or ultrasonic (n = 111) intraoperative guidance. The performing surgeon had documented ease of use, accuracy and users acceptance of the chosen guidance tool. The data were summarised together with the patients history and images in to a descriptive report. Since 1992 we noted a steady increase in guiding operations from 4% to 24%, mainly due to the more frequent use of ultrasound guidance. Saving time, easy handling, accuracy and plausible guidance with real time pictures have been the major advantages in favouring ultrasound guidance. Additionally, the freedom in choosing the appropriate approach seems to be essential. To achieve full advantage of all these benefits, experience and individual expertise are necessary. Conversely, the high accuracy of stereotactic guidance is not within the reach of the ultrasound, which is sufficient to guide the operation. According to our experiences, we recommend intraoperative ultrasound as an easy guiding tool. Except a few cases, this guiding tool seems to be superior to the stereotactic localisation of intracranial lesions.

Brain Mapping↗
PubMed1995

[Traumatic injury of the internal carotid artery in the extracranial segment. Description of a severe late complication].

Blunt traumatic injury to the extracranial internal carotid artery may lead to a dissection with resultant stenosis, occlusion, or a dissecting aneurysm. Delayed clinical presentation weeks, months, and even years after the injury is rare, but has important diagnostic, therapeutic and forensic implications. In the current era, where computed tomography is replacing angiography as the main diagnostic procedure, it is extremely important to keep this diagnosis in mind. We report the case of a 31-years-old male patient, who did well after a motorcycle accident with head and neck injury for six years. Since then he only showed left-side Horner's syndrome, which unfortunately was ignored. In 1993 the patient developed occlusion of central retinal artery, and after a therapy with streptokinase he presented with right-side palsy and complete aphasia. CT-scan revealed a large edematous infarction in the middle cerebral artery territory. Transfemoral digital subtraction angiography however demonstrated a dissecting aneurysm of the left extracranial internal carotid artery as the source of intracranial embolization. Severe sequelae of this kind can only be warded of by early diagnosis and proper surgical therapy of vascular injury. Therefore even minimal symptoms suggesting the possibility of a traumatic injury to the carotid artery are recommending timely angiographic investigation.

Adult↗
PubMed1994

[Studies on 1,4-naphthoquinones. 23. 2-3-Halogen-2-3-nitrophenyljuglone derivatives, synthesis and cytotoxic properties].

Radical arylation of 1,4-naphthoquinones is possible by oxidative decarboxylation of 2- and 4-nitrobenzoic acid. With 2- and 3-halogenojuglone derivatives the 4-nitrophenyl compounds 10-13 are prepared in good, the 2-nitrophenyl analogues 14-17 only in poor yields. All compounds are inactive against the virus types HSV and HIV and their marked cytotoxicity in part depends on the substitution pattern. The 3-aryl and o-nitro derivatives are more active than their 2-aryl and p-nitro analogues and the influence of the chloro or bromo substitution is only remarkable in the case of 12/13.

Animals↗
PubMed1994

Composite cerebral metastasis and oligodendroglioma: an exceptional form of mixed neoplasia.

Our report describes the uncommon case of a 61 year old female patient who underwent a left parietooccipital craniotomy and extirpation of a malignant tumor. Histological examination revealed a metastatic carcinoma of mammary origin intimately intermingled with a calcified oligodendroglioma WHO II. The preexisting oligodendroglial part had been detected four years before, but since then had been misinterpreted as a glious scar resulting from a previous brain trauma. Three years before neurosurgical intervention, the patient had undergone a left side mastectomy. The histological finding at that time was a solid breast tumor WHO T1N0. The occurrence of cerebral mixed neoplasias and possible causal factors are discussed.

Brain Neoplasms↗
PubMed1994

Use of a modified cluster sampling method to perform rapid needs assessment after Hurricane Andrew.

STUDY OBJECTIVE: To rapidly obtain population-based estimates of needs in the early aftermath of Hurricane Andrew in South Florida. METHODS: We used a modified cluster-sampling method (the Expanded Programme on Immunization [EPI] method) for three surveys. We selected a systematic sample of 30 quarter-mile square clusters for each survey and, beginning from a random start, interviewed members of seven consecutive occupied households in each cluster. Two surveys were of the most affected area (1990 population, 32,672) at three and ten days after the hurricane struck; one survey was of a less affected area (1990 population, 15,576) seven days after the hurricane struck. MEASUREMENTS AND MAIN RESULTS: Results were available within 24 hours of beginning each survey. Initial findings emphasized the need for restoring utilities and sanitation and helped to focus medical relief on primary care and preventive services. The second survey of the most affected area showed improvement in the availability of food, water, electricity, and sanitation (P < or = .05). There was no evidence of disease outbreaks. CONCLUSION: For the first time, the EPI method provided population-based information to guide and evaluate relief operations after a sudden-impact natural disaster. An improvement over previous approaches, the EPI method warrants further evaluation as a needs assessment tool in acute disasters.

Adult↗
PubMed1993

[Neuralgia of the glossopharyngeal nerve with syncope attacks].

The anatomical viewpoints of nervus IX and its surrounding structures are explained. The authors report on one case of symptomatology of glossopharyngeal neuralgia combined with cardiac arrests. Finally, pathogenesis and surgical treatment of glossopharyngeal neuralgia are discussed.

Craniotomy↗
PubMed1993

[Stereotaxic biopsy of brain tumors].

The work re-evaluates the meaning of stereotactic bioptic examination in 50 neurosurgical patients. Bioptic material gained for histologic purposes does not secure always the achievement of the correct histologic diagnosis. The authors critically reevaluate the possibilities of this diagnostic method. They do not consider as adequate to claim multiple expansive processes to be inoperable, respectively as being refractory towards therapy, when the histologic conclusion is lacking. In cases of inconsistency in histologic conclusions from two neuropathologists the further fate of the patient is conditioned by the neuropathologist's stand-point, but also by the clinical experience of the neurosurgeon who overtakes the final responsibility for the patient's further fate. Recently available methods (CT,MR, spectrography) are diagnostically not so precise as to be able to manage without stereotactic biopsy. (Tab. 3, Fig. 5, Ref. 10.).

Biopsy, Needle↗
PubMed1993

[The role of the neurosurgeon in histopathologic diagnosis].

Neurosurgical practice has proved that the establishment of a correct neurohistopathologic diagnosis is sometimes difficult. Inconsistency of diagnoses resulting from unbiased examinations of several neuropathologists is not uncommon. The authors-neurosurgeons-have performed 300 fast neurohistopathologic examinations by means of smear technique. Correct diagnosis was stated in more than 90% of cases. Bioptic examination may represent a contribution in cases where postoperative irradiation is indicated, namely under diagnostically controversial circumstances. The authors re-evaluate the possibilities of utilization of smear technique for the purpose of histopathologic diagnostics performed directly by neurosurgeons. (Tab. 7, Ref. 5.).

Biopsy↗
PubMed1992

[Percutaneous lumbar thermal sympathectomy: method, indications and results].

Thermal lumbar sympathectomy has been the method of choice since the 'eighties in the treatment of reflex dystrophy. We are using this method since January 1990. First results are presented and critically analysed. 15 patients who underwent thermal lumbar sympathectomy were examined and interviewed 1 year after treatment. 7 patients reported persisting pain relief, while the remaining 8 did not.

Adult↗
PubMed1992

In vitro inhibition and stimulation of purified prostaglandin endoperoxide synthase by flavonoids: structure-activity relationship.

We studied the effects of 37 flavonoids on prostaglandin endoperoxide synthase (EC 1.14.99.1) purified from sheep vesicular glands. Nonplanar flavans were more potent inhibitors than planar flavones and flavonols (IC50 values were, e.g., 40 mumol/l for catechin and epicatechin, 110 mumol/l for galangin, 490 mumol/l for quercetin and 450 mumol/l for kaempherol). Different inhibition mechanisms were observed, i.e. uncompetitive inhibition for nonplanar flavonoids and competitive or noncompetitive inhibition for planar flavonoids. Potent inhibitors in the group of flavones were substances with an o-dihydroxy structure in the B ring and in the group of flavonol substances with two hydroxyl groups in position 5 and 7 of the A ring. None of the flavanones studied caused significant inhibition, except for the flavanone-3-ol, silibinin (silybin), which caused potent inhibition with an IC50 of 120 mumol/l. Several flavonoids, which were able to inhibit the prostaglandin endoperoxide synthase at higher concentrations, were also able to stimulate the enzyme at lower concentrations. These results indicate that the flavonoids should be divided into two groups according to their capacity to inhibit the prostaglandin endoperoxide synthase, represented by planar and nonplanar substances as in each group a close correlation between structure and inhibitory activity was observed.

Animals↗
PubMed1989

Substrates for arachidonic acid co-oxidation with peroxidase/hydrogen peroxide. Further evidence for radical intermediates.

We tested the ability of a wide variety of organic compounds, including benzene and phenol derivatives, aromatic amines, pyrazoline derivatives and other non-steroidal anti-inflammatory drugs, to act as cosubstrates during the horseradish peroxidase/hydrogen peroxide-mediated oxygenation of arachidonic acid. Structural requirements for drug activation in our system proved to be an aromatic system and ring substitution by an easily oxidizable group. Complementary substituents modified drug activation. Among the phenol derivatives and aromatic amines we found the meta-substituted compounds to be significantly more effective than their ortho- and para-substituted analogues, indicating the involvement of radical intermediates in this type of reaction. The radical from 1-phenyl 3-methyl 2-pyrazolone(5) was detected by electron paramagnetic resonance spectroscopy. Kinetic studies on this radical were in good accordance with time-dependent measurement of arachidonic acid oxygenation.

Arachidonic Acid↗