Thrombin stimulates activation of the cerebral 5-lipoxygenase pathway during blood-brain cell contact.

The purpose of this study was to identity the trigger mechanism activating the 5-lipoxygenase pathway during blood-brain cell contact and to estimate the contribution of blood and brain cells to the cysteinyl-leukotriene (LT) biosynthesis observed under these conditions. Incubation of dissociated rat brain cells in Krebs-Henseleit solution for up to 60 min did not stimulate any detectable cysteinyl-LT biosynthesis. Incubation of recalcified rat whole blood in vitro for up to 60 min led to release of only small amounts of cysteinyl-LT into the serum samples. However, coincubation of dissociated rat brain cells with physiologically recalcified autologous whole blood triggered a time-dependent release of large amounts of immunoreactive cysteinyl-LT into the serum samples. By reverse-phase HPLC, immunoreactive cysteinyl-LT was identified as a mixture of LTC4, LTD4, and LTE4. The extent of the 5-lipoxygenase stimulation depended on the amount of autologous blood coincubated with the dissociated brain cells. Activation of the 5-lipoxygenase pathway also occurred with coincubation of dissociated rat brain cells with recalcified autologous plasma. Stimulation of cysteinyl-LT biosynthesis during blood-brain cell contact remained unaffected by aprotinin, but concentration-dependent inhibition by the structurally and functionally unrelated thrombin inhibitors D-Phe-Pro-Arg-CH2Cl and recombinant hirudin was seen. Finally, when dissociated rat brain cells were incubated in Krebs-Henseleit solution in the presence of human alpha-thrombin, a concentration-dependent release of cysteinyl-LT into the buffer samples was observed. These data demonstrate that, in rats, during blood-brain cell contact, stimulation of the 5-lipoxygenase pathway in brain cells proceeds via alpha-thrombin as effector molecule.

Intravascular cysteinyl-leukotriene formation by clotting whole human blood. Evidence from clamped umbilical vein segments and thrombus specimens.

We have recently demonstrated that contact activation of the intrinsic coagulation cascade in vitro is accompanied not only by thromboxane (TX) B2 generation but also by the formation of 5-lipoxygenase-derived cysteinyl-leukotrienes (LT). In our present study we have investigated the effects of the vascular wall on the eicosanoid formation by whole human blood. Incubation of whole human blood in clamped segments of autologous umbilical veins incubated in oxygenated Tyrode solution led to a time-dependent generation of cysteinyl-LT and TXB2 in the blood samples. A clear dissociation in the time-dependent production profiles was observed with cysteinyl-LT practically reaching a plateau phase at 60 min while TXB2 levels increased up to 90 min. In blood samples incubated in glass tubes for 60 min TXB2 production was about 13 times higher and cysteinyl-LT formation only about half as much as in the umbilical vein segments indicating a differential stimulation of both the cyclooxygenase and 5-lipoxygenase pathway of arachidonic acid metabolism in these experiments. By reverse phase HPLC the immunoreactive cysteinyl-LT were identified as a mixture of LTC4, LTD4 and LTE4. Since the data were suggestive of intravascular cysteinyl-LT formation in thrombotic vessels, thrombus specimens from patients with acute deep vein thrombosis of the lower limb were analysed for these compounds by combined reverse phase HPLC and specific radioimmunoassay.(ABSTRACT TRUNCATED AT 250 WORDS)

Transcranial Doppler monitoring during induction of anesthesia: effects of propofol, thiopental, and hyperventilation in patients with large malignant brain tumors.

Disturbed autoregulation and CO2 reactivity have been reported in patients with brain tumors. Therefore, we decided to monitor the cerebrovascular effects of anesthetic drugs and hyperventilation. Transcranial Doppler sonography (TCD) can measure noninvasively alterations of flow velocities (v) and cross-sectional vessel area (VA) in large brain arteries. Twenty-eight patients with large malignant brain tumors in the territory of the middle cerebral artery (MCA) randomly received propofol or thiopental for induction and maintenance of anesthesia. Mean arterial pressure (MAP), heart rate (HR), and TCD parameters (vMCA and VA of the tumor or nontumor side) were determined at six data points (DP). The first measurements (MAP, HR, and TCD of the nontumor side) were performed before (DP I) and 60 s after (DP II) induction of anesthesia with either 2 mg/kg propofol or 4 mg/kg thiopental. After intubation and normoventilation (50% O2 in air), 0.05-0.1 mg/kg midazolam and an alfentanil infusion (100 micrograms/kg x h) were initiated. Then MAP, HR, vMCA, and VA of the tumor side were analyzed before (DP III) and 60 s after (DP IV) either propofol (1 mg/kg) or thiopental (2 mg/kg) were given. Finally, the effects of hyperventilation on HR, MAP, vMCA, and VA (tumor side) were determined (DP V and VI). Mean +/- SD, thiopental or propofol reactivity (non-tumor and tumor side) and CO2 reactivity (tumor side) were calculated; statistical comparison between DP I and II, III and IV, and V and VI was performed by paired t tests (p < 0.05). Unpaired t tests were used to evaluate differences between groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral manifestation of an actinomycosis infection. A case report.

Affection of the CNS by actinomycosis is a rare but treatable manifestation of an infection with actinomyces israeli. Neurological involvement includes a meningeal, granulomatous and also pseudotumoral form. We report the case of a patient suffering from an intracerebral actinomycosis abscess. The source of infection was the upper jaw. After a right frontal craniotomy the intracerebral abscess was removed. Postoperatively the patient received initially a combined antiedemateous and antibiotic therapy with 12 mg dexamethasone and 6 g cefotaxime and 3 g amoxicilline. After 4 weeks of treatment with improving neurological deficits dexamthasone therapy was reduced followed by an exclusive antibiotic therapy for another 4 weeks. During this time the patient recovered completely.

Endolymphatic sac tumour. A case report.

We present the case of a patient with an endolymphatic sac tumour (ELST). This rare tumour entity has only recently been defined and despite a well characterized clinical appearance misdiagnosis as jugular paraganglioma is frequent. A 68-year-old woman was admitted to our Neurosurgical Department with a mass lesion extending from the left temporal bone to the cerebello-pontine angle (CPA). Radiological features were high vascularization, contrast enhancement and destruction of the os petrosum. After preoperative angiographic embolization the tumour was removed in two surgical interventions, first via a lateral suboccipital approach and second by petrosectomy. The lesion proved to be a typical endolymphatic sac tumour by a synopsis of histological, radiological and clinical features. ELST should be taken into consideration in patients with mass lesions in the cerebellopontine angle destroying the petrous bone and resembling paraganglioma. Since slow growth rate and lack of metastases are particular features of ELST, complete resection of the tumour results in long survival times without adjuvant chemo- or radiotherapy.

What the neurosurgeon needs to know about the coagulation system.

Intracranial surgery is often complicated by thromboembolic events including the life-threatening pulmonary embolism. After head trauma and in patients with brain tumors disseminated intravascular coagulation (DIC) can occur, characterized by the triggering of the coagulation cascade and the depletion of coagulation factors which ultimately leads to bleeding. The identification of patients at high risk as well as the early diagnosis of hemostatic problems uses routine laboratory parameters such as partial thromboplastin time and prothrombin time reflecting the intrinsic and the extrinsic pathway of the coagulation respectively. Thrombin antithrombin III complexes (TAT) and prothrombin fragment 1 + 2 (F1 + 2) are further indicators of an activation of the coagulation whereas fibrinogen degradation products (FDP) refer to the fibrinolytic system. The basic principles of coagulation and fibrinolysis are summarized as well as the changes of laboratory parameters accompanying DIC, hypercoagulability and hyperfibrinolysis.

Chiari malformation type I with concomitant persistent trigeminal artery -- report of an unusual case and a review of the current literature.

BACKGROUND: Chiari malformation type I is a stenosis of the subarachnoid space at the level of the foramen magnum due to a small posterior fossa and herniation of the cerebellar tonsils. We present here the unusual case of a Chiari malformation in conjunction with a persistent trigeminal artery and hypoplasia of the basilar artery, also known as a Saltzman anomaly. CASE REPORT: A 34-year-old female physician presented with recurrent headaches, bilateral weakness of deltoid muscles and numbness of the fingertips 3 to 5. A cranial MRI revealed a descent of the cerebellar tonsils to the level of C2 and a supracerebellar cyst. During surgery, a decompressive suboccipital craniectomy was performed. The supracerebellar cyst was fenestrated and the cerebellar tonsils were resected bilaterally. Two days after surgery the patient developed cranial nerve dysfunction and a right-sided hemiparesis. Cerebral angiography revealed a Saltzman type 1 anomaly with persistent primitive trigeminal artery and hypoplasia of the basilar artery. DISCUSSION: This is the first report in the literature about the coincidence of both unusual anomalies. The latest literature of both rare anatomy and the unusual clinical course will be discussed.

Computer tomographic assessment of the pre- and postoperative ventricle width in patients with traumatic intracranial haematomas.

The cellular integrity of the brain tissue is not only disturbed by space occupying traumatic intracranial haematomas but also by traumatic brain tissue damage and the accompanying oedema. Due to the insufficiency of visual inspection, methods for an objective quantification of the ventride width are required. A number of techniques have been used for evaluation of the CSF-space after cerebral trauma. In the present study changes of the ventricle size have been evaluated by using planimetric measurements of CT scans. In 222 patients with traumatic intracranial haematomas significant changes in the ventricle width could be demonstrated when the data were analysed by Wilcoxon signed rank test for pair differences. Comparison of the initial cranial computed tomography (CT) with a CT 14 days later revealed a significant dilatation of the ventricle width in all age groups in the second measurement. When patients were divided into groups with or without signs and symptoms of brainstem alteration after trauma, patients with symptoms of brainstem alteration exhibited a significantly greater ventricle width as compared to patients without such symptoms and signs.

[Plasmacytoma involving the atlas and axis]. / Plasmozytombefall von Atlas und Axis.

Report on a rare localisation of a plasmocytoma in the upper part of the cervical spinal cord.

Computer tomographic assessment of perifocal edema surrounding tumors of the cerebral cortex.

It is well known, that intracranial tumors can induce peritumoral edema of variable extension. Some authors describe a dependency between malignancy of tumor and size of perifocal edema. It is generally accepted that metastases induce the largest perifocal edema. This study investigates the relationship between the volume of the perifocal edema and its distance from the surface of the cortex.

[Patient expectations from lumbar intervertebral disk operations-- an analysis of a questionnaire survey of 200 patients]. / Patientenerwartungen vor lumbalen Bandscheibenoperationen--Eine Analyse aus einer Fragebogenaktion an 200 Patienten.

Using a questionnaire 200 patients with lumbar disc herniation syndrome were asked preoperatively about important aspects of care during their hospitalisation. They had to answer 17 questions using a classification system of 7 points. The most important point for patients was the qualification of the head of the clinic, followed by a distinct explanation about risks during operation. Aspects of discharge from clinic, recovery in fitness for work or the extent of the scar were of minor interest.

Retrieval of a disconnected ventriculoperitoneal shunt catheter by laparoscopy in a newborn child: case report.

In rare cases the peritoneal catheter of a ventriculoperitoneal shunt dislodges from the valve and the peritoneal tube migrates into the peritoneal cavity. For retrieval of the free intraperitoneal shunt, tube laparoscopy is the initial method of choice.

[Percutaneous ultrasound-assisted tumor cyst puncture of a recurrent intracerebral brain tumor]. / Perkutane ultraschallgesteuerte Tumorzystenpunktion eines intrazerebralen Hirntumorrezidivs.

The beneficial effects obtained by using transcutaneous ultrasound-guidance for brain puncture will be shown by a case report of a patient with a tumor-cyst after operation for a recurrent of an astrocytoma. In total this method was performed in 18 patients with high effectiveness and without any complications.