[Reconstruction of the anterior wall of frontal sinus with biopolymers]

The two biopolymers Ethisorb and its modification Ethisorb Rapid were implanted in 80 defects of the anterior wall of frontal sinus in 20 Goettingen minipigs to analyze density of trabecula (Mann-Whtiney-Rank-Sum-Test), degradation of biopolymers and histomorphology. To optimate bone regeneration, particular resorbable membranes and autogenic spongiosa chips were used. The animals were killed after six, 12, 26 and 52 weeks and then postoperative undecalcified bone cuts were obtained. All in all, with Ethisorb contrary to Ethisorb Rapid a faster biopolymer resorption in the 12th and 26th week with a statistically significant greater density of trabecula could be observed. The use of resorbable membranes and autogenic spongiosa chips led, in comparison to simple implantation of biopolymers, to significantly greater densities of trabecula. The use of Ethisorb contrary to Ethisorb Rapid with membranes led to a Guided Bone Regeneration (GBR) with persistence of membrane particles to week 12 and 26. By mixing biopolymers with autogenic spongiosa chips a multiloculated bone regeneration could be generated. For Ethisorb with resorbable membranes and autogenic spongiosa chips the best bone regeneration with highest densities of trabecula could be recognized.

Spontaneous adrenal hemorrhage: a little-known complication of intracranial tumor surgery. Case report

Nontraumatic adrenal hemorrhage in adults is uncommon and unexpected in the context of intracranial surgery. The authors report on a patient in whom hemodynamically relevant retroperitoneal bleeding developed within hours after an otherwise uneventful operation for a falcine meningioma. In this brief report they seek to draw attention to this rare but life-threatening complication, because rapid diagnosis can be life-saving.

[Histological comparison of different biopolymers in osseous defects]

The goal of this animal study in Goettingen minipigs was to compare Ethisorb with its modification Ethisorb Rapid where the hydrolytic degradation process has started, with respect to degradation and bony substitution qualitites. For comparison, both biopolymers were implanted with and without addition of autogenic spongiosa chips in comparison with blank defects in metaphysis of the tibia. The animals were killed after six, 12, 26 and 52 weeks. Undecalcified bone cuts were obtained and subjected to a histomorphometric and histomorphological analysis. All in all, with increasing time after implantation a continuous decrease of the density of trabecula could be observed. In comparison to Ethisorb Rapid and blank defects, the implantation of the slowly degrading but quickly resorbing Ethisorb led to statistically significantly higher densities of trabecula (Tuckey Test, p < or = 0.05) and to best bone regeneration. In contrast to this, Ethisorb Rapid could be degraded more quickly but resorbed more slowly. In the polarizing microscope, Ethisorb could still be detected after 12 weeks of implantation. Ethisorb Rapid could still be detected after 26 weeks of implantation. To conclude, Ethisorb proved to be a suitable scaffold for autogenic spongiosa-chips in critical-size defects of the tibia so that a multiloculated bone regeneration could be obtained.

5-Hydroxytryptamine-induced contraction of human temporal arteries coexpressing 5-HT2A receptors and wild-type or variant (Phe124Cys) 5-HT1B receptors: increased contribution of 5-HT1B receptors to the total contractile amplitude in arteries from Phe124Cys heterozygous individuals

OBJECTIVES

Expression studies of the rare Phe124Cys sequence variant of the human 5-HT1B receptor in HEK293 cells demonstrated that 5-hydroxytryptamine (5-HT) and sumatriptan had both three times higher binding affinity and agonist potency at the variant receptor than wild-type receptor. We examined whether in-vivo expression of the variant compared to the wild-type Phe/Phe genotype at codon 124 of the 5-HT1B receptor in human temporal arteries modifies their agonist-induced contraction.

METHODS

Rings of arteries, coexpressing 5-HT1B and 5-HT2A receptors, from 98 patients undergoing neurosurgery were set up to measure contraction. Blood sample genotyping was performed by PCR using a mutagenic primer which induces a NheI restriction site in the Cys but not in the Phe allele.

RESULTS

Three patients exhibited the Cys/Phe genotype, probably yielding coexpression of both the 124Phe and the 124Cys 5-HT1B receptors. In 95 Phe/Phe patients, exclusively the 124Phe receptor was expressed. The contractile potencies of 5-HT and sumatriptan were not significantly different in arteries from Cys/Phe or Phe/Phe individuals. The 5-HT1B receptor-selective antagonist SB224289 was five-fold more potent in blocking the effects of 5-HT in arteries from three Cys/Phe than from 30 Phe/Phe individuals (P < 0.03). The fraction of 5-HT effects via 5-HT1B receptors, related to the total contractile amplitude via 5-HT1B and 5-HT2A receptors, was enhanced from 0.42 +/- 0.03 in 88 Phe/Phe individuals to 0.75 +/- 0.10 in three Cys/Phe individuals (P < 0.05).

CONCLUSIONS

Although the potency of 5-HT1B receptor agonists does not differ between arteries from Phe/Phe and Cys/Phe individuals, the contribution of 5-HT1B receptors to the mediation of the effects of 5-HT is increased in Cys/Phe individuals.

Time sparing and effective procedure for dural closure in the posterior fossa using a vicryl mesh (Ethisorb®)

INTRODUCTION

Dural defects and cerebrospinal fluid (CSF) leaks are a common problem following posterior fossa surgery. The management includes either nonoperative management (e.g. external lumbar drainage) or surgical re-exploration.

OBJECTIVES

We present our surgical, clinical and histopathological experience of dural closure in the posterior fossa. In order to avoid CSF leaks we developed a simple but effective and time-sparing method using a well-cut sheet of a vicryl-poly-pdioxanone mesh (Ethisorb) covering the whole defect of the craniectomy. Additional fibrin glue or sealant is not necessary. Special attention was focused upon the frequency of postoperative complications, in particular infection rate and CSF leaks.

PATIENTS

85 patients were treated with vicryl mesh as dural substitute after posterior fossa surgery due to distinct pathologies. An illustrative case is presented. RESULTS. In none of the patients a postoperative infection was observed. Four patients presented postoperative CSF leakage and were treated by percutaneous lumbar drainage. Three of the patients improved completely, requiring no additional treatment. Only in one case defect covered by a vicryl mesh, a surgical reexploration became necessary.

CONCLUSION

We consider the vicryl mesh (Ethisorb) as an ideal dural substitute especially for the dural closure of the posterior fossa.

BIBN4096BS and CGRP(8-37) antagonize the relaxant effects of alpha-CGRP more than those of beta-CGRP in human extracranial arteries

We hypothesize that dilatation of extracranial arteries during migraine could be caused by CGRP. We compared the relaxant effects of alpha-calcitonin gene-related peptide (alpha-CGRP) and beta-calcitonin gene-related peptide (beta-CGRP) and the antagonism by BIBN4096BS and CGRP(8-37) on rings of human temporal and occipital arteries precontracted with KCl. beta-CGRP relaxed temporal (-logEC50M = 8.1) and occipital arteries (-logEC50M = 7.6) with 19-fold and 29-fold lower potencies respectively than alpha-CGRP. Nearly maximal effective concentrations of alpha-CGRP (4 nM) and beta-CGRP (50 nM) caused stable relaxations of the temporal artery for 4 h without fading. BIBN4094BS antagonized the effects of alpha-CGRP (pK(B) = 10.1 and 9.9, respectively) more than beta-CGRP (pK(B) = 9.3 and 9.2 respectively) on both temporal and occipital arteries. CGRP(8-37) antagonized the effects of alpha-CGRP (pK(B) = 6.6 and 6.4 respectively) more than beta-CGRP (pK(B) = 5.7 and 5.5 respectively) on both temporal and occipital arteries. Antagonism of the relaxant effects of alpha-CGRP (4 nM) and beta-CGRP (50 nM) by BIBN4096BS (10 and 100 nM) was reversible for beta-CGRP, but irreversible for alpha-CGRP, 1 h after BIBN4096BS washout. We conclude that alpha-CGRP and beta-CGRP interact either at different binding sites of the same CGRP receptor system or all together with different receptor systems in human extracranial arteries. BIBN4096BS binds more firmly to the receptor activated by alpha-CGRP than to the receptor activated by beta-CGRP.

Contouring of Cranial Vault Irregularities With Hydroxyapatite Cement: A Clinical and Experimental Investigation

The biocompatible hydroxyapatite cement (HAC) is a welcome alternative to the traditional use of autogenous bone for postoperative corrections of cranial vault irregularities. The authors performed experimental studies to show the safety and osseointegration capacity of HAC on animal models and confirm the osseous replacement without toxic reactions. The purpose of the current study was to analyze the clinical outcome after correction of secondary cranial vault irregularities with HAC. Twenty-one patients were treated for residual cranial frontal bone defects after craniotomy with HAC (Bone Source, Stryker Leibinger GmbH, D-79111 Freiburg, Germany). The average age was 38.5 years (range, 23-57 years). All of the patients were male. The average volume per patient was 53.83 g. The volume implanted ranged from 25 to 125 g; in all cases the dura was covered with bone. Irregularities resulted from sunken bone. The authors' clinical series demonstrates that a satisfactory and aesthetically pleasing result can be achieved in one surgical intervention in patients for surgical correction of postoperative cranial vault irregularities using HAC. It permits osseointegration, which makes it relatively resistant to infection. HAC is easy to apply and shape to suit individual needs. HAC is a welcome alternative to the traditional use of autogenous bone for postoperative corrections of cranial vault irregularities.

Cellular, histomorphologic, and clinical characteristics of a new octyl-2-cyanoacrylate skin adhesive

Short-chained cyanoacrylates have been used for many years for topical skin closure. Toxic effects in cell culture of a new long-chained octyl-2-cyanoacrylate tissue adhesive are compared with those of short-chained ethyl-2- and butyl-2-cyanoacrylates. Two cellular tests were used: the agar overlay test and the MTT test. An in vitro test using copper plates coated with the three types of cyanoacrylates serves for evaluating the stability of polymerized skin adhesives. Bilateral neck skin incisions in Goettingen miniature pigs were glued on one side with Dermabond. On the other side, conventional sutures were applied. After the pigs were killed, the resulting skin samples were tested for the tensile strength of their wound stability. Samples of pig dermis were exemplarily and histomorphologically characterized. A clinical examination after submandibular lymph node dissection should examine the application in humans. Cell culture tests were used to show the toxic effects of the three cyanoacrylates. In a copper test, octyl-2-cyanoacrylate was more stabile than ethyl- and butyl-cyanoacrylates. Breaking strength was 30% lower 28 days after operation with the new product than with sutures. In electron microscopy, octyl-2-cyanoacrylate showed no disadvantages with regard to tissue regeneration and no histotoxicity. For plastic surgery, this new topical skin adhesive is a real alternative with attractive results, as compared with conventional suture.

Functional 5-HT receptors in human occipital artery

5-HT receptors were studied in human occipital arteries, obtained from patients during neurosurgery. We detected mRNA for the following receptors (incidence): 5-HT(1B) (14/18), 5-HT(1D) (15/18), 5-HT(2A) (16/18), 5-HT(2B) (8/8), 5-HT(4(a)) (13/18), 5-HT(4(b)) (5/18), 5-HT(4(g)) (7/18), 5-HT(4(i)) (1/18), 5-HT(7(a/b)) (10/18) and 5-HT(7(d)) (12/18). 5-HT contracted and relaxed arterial rings at low (-logEC(50) M=7.0) and high (-logEC(50) M=4.2) concentrations, respectively. 5-HT-evoked contractions were antagonized partially by both 5-HT(1B)-selective SB224289 (200 nM) and 5-HT(2A)-selective ketanserin (1 microM) but not by 5-HT(1D)-selective BRL15572 (500 nM) or prazosin (1 microM). Sumatriptan caused contractions (-logEC(50) M=6.8, intrinsic activity with respect to 5-HT=0.3). Sumatriptan-evoked contractions were antagonized by SB224289 with high potency (pK(B)=9.4) but not by BRL15572. 5-HT-induced relaxations were resistant to blockade by 5-HT(1B)-selective SB224289 (1 microM), 5-HT(1D)-selective BRL15572, 5-HT(2B)-selective SB204741 (1 microM), 5-HT(4)-selective GR113808 (100 nM) and 5-HT(7)-selective SB269970 (1 microM), and a combination of SB204741 and SB269970, inconsistent with an involvement of 5-HT(1B), 5-HT(1D), 5-HT(2B), 5-HT(4) and 5-HT(7) receptors. Triton X-100 treatment of the arteries abolished acetylcholine-induced relaxations of rings precontracted by prostaglandin F(2alpha), but a reduction of the relaxant effects of 5-HT did not reach significance. Nitro-L-arginine (1 mM) reduced 5-HT-induced relaxations, suggesting a contribution of nitric oxide released from endothelial cells. Ketanserin (1 microM) prevented the relaxant effects of 5-HT. We conclude that 5-HT contracts human occipital artery through 5-HT(1B) receptors at low concentrations and through 5-HT(2A) receptors at high concentrations. Sumatriptan contracts mostly through 5-HT(1B) receptors. These results are consistent with the 5-HT(1B) and 5-HT(2A) mRNA data. 5-HT-induced relaxation is mediated, in part, through ketanserin-sensitive receptors, but 5-HT(1B), 5-HT(1D), 5-HT(2B), 5-HT(4) and 5-HT(7) receptors appear not to be involved.

Altered expression and new mutations in DNA mismatch repair genes MLH1 and MSH2 in melanoma brain metastases

Brain metastases, including those of malignant melanoma (known for its high genomic instability), are the most common intracranial tumors. The main objective of this study was to investigate expression and mutation in the DNA mismatch repair system in melanoma brain metastases. Expression of MLH1, MSH2, PMS1 and PMS2 was investigated immunohistochemically in 31 melanoma metastatic tumors. Mutational analysis of MLH1 and MSH2 was performed in 17 melanoma brain metastases. Loss of MLH1 and MSH2 expression was found in 10/31 and 12/31 tumors. PMS1 (27/31) and PMS2 (28/31) expression was preserved in the majority of lesions. Potential missense mutation was found in MSH2 (exon 13) in 2/17 melanomas. Mutation in the intron sequence between exon 14 and 15 of MLH1 (exon 15) was observed in 4/17 cases. Our results indicate that the two major DNA mismatch repair genes, MLH1 and MSH2, are more frequently affected by alterations in the DNA mismatch repair system than the helper genes PMS1 and PMS2. The presence of mutations of MSH2 and MLH1 in melanoma brain metastases, which has not been found in primary melanomas, indicates the high genomic instability of melanoma brain metastases.

The potential value of ultrasonography in the evaluation of carpal tunnel syndrome

The authors compared ultrasonography with electrophysiology for the diagnosis of carpal tunnel syndrome (CTS) on 110 clinically affected wrists. An increased cross sectional area in the proximal carpal tunnel larger than 0.11 cm(2) in combination with compression signs on longitudinal scans proved to be highly predictive for CTS (sensitivity, 89.1%; specificity, 98.0%). Ultrasound was comparable to electrophysiology in the diagnosis of CTS, and in 35% of cases changes in morphology suggested a specific therapeutic strategy.

Carpal tunnel syndrome caused by thrombosis of the median artery: the importance of high-resolution ultrasonography for diagnosis. Case report

The rare case of a patient with carpal tunnel syndrome caused by thrombosis of a persistent median artery is presented. Progressive pain in the wrist and dysesthesias in the third and fourth fingers were the atypical complaints. High-resolution ultrasonography revealed a bifid median nerve that was compressed by an occluded median artery. The intraoperative findings are described, and emphasis is placed on the importance of using high-resolution ultrasonography for presurgical diagnosis.

BIBN4096BS is a potent competitive antagonist of the relaxant effects of alpha-CGRP on human temporal artery: comparison with CGRP(8-37)

Release of CGRP during migraine may produce harmful dilatation of cranial arteries, thereby possibly causing pain. We have compared the antagonism by BIBN4096BS and CGRP(8-37) of the relaxant effects of alpha-CGRP on rings of human temporal artery. alpha-CGRP relaxed the arteries precontracted with 9 - 24 mM KCl (-logEC50=9.4) nearly as efficaciously as sodium nitroprusside (10 microM). BIBN4096BS (0.1 - 100 nM) antagonized the effects of alpha-CGRP in surmountable manner with slopes of Schild-plots not different from unity. -LogKB values of 10.1 and 10.4 were estimated for BIBN4096BS when administered before or during the KCl-contracture respectively. BIBN4096BS (1 microM) did not modify the relaxant effects of papaverine and sodium nitroprusside. CGRP(8-37) (1 - 10 microM) antagonized the effects of alpha-CGRP in a surmountable manner with slopes of Schild-plots not different from unity. -LogKB values of 6.6 and 6.7 were estimated for CGRP(8-37) administered before or during the KCl-contracture respectively. The high affinity of BIBN4096BS for CGRP receptors of human temporal artery makes it an excellent tool to explore the hypothesis of CGRP-evoked cerebral vasodilation in migraine.

Correction of skull defects using hydroxyapatite cement (HAC)--evidence derived from animal experiments and clinical experience

BACKGROUND

The development of satisfactory cranioplasty material and technique has been a continuing bio-engineering challenge. Cranial defects resulting from trauma, tumour or infection are most frequently reconstructed with nonviable alloplastic materials. At present, all synthetic or biological materials in the use for human cranioplasty are more or less ideal.

METHODS

The in vivo properties of a fully resorbable bony substitute--hydroxyapatite cement (HAC, BoneSource) are described in clinical investigations and animal experiments. HAC is prepared from calcium phosphate precursors which are hydrated and harden endothermically at 37 degrees C to form hydroxyapatite. Bone formation and resorption characteristics of HAC are examined in an adult minipig cranial defect model.

FINDINGS

Cranial bone integrity has been restored in ten of eleven patients. Radiographic examination 6 months after surgery reveal a successful reconstruction of the skull defects. Sections of the cranial defect site from animals sacrificed at 12, 18 and 40 weeks demonstrate that new bone formation proceeds in HAC filled osseous defects. Histomorphological evaluation of HAC resorption and new bone formation indicates that HAC is nearly completely resorbed within 40 weeks and replaced by new bone with no loss in size or volume.

INTERPRETATION

Hydroxyapatite cement (HAC) has an excellent biocompatibility (non-immunogenic and non-toxic), seems to be an optimal implant for cranial reconstruction and provides a biological scaffold for bone formation. However, further studies need to be conducted to determine the long-term stability of HAC.

A case of neurocysticercosis-differential diagnostic aspects

Neurocysticercosis is no medical rarity but in non-endemic countries especially, a high degree of physician awareness is necessary for diagnosis. The case of a German female patient who had focal seizures for the first time at the age of 23 caused by a cerebral cyst of cysticercus cellulosae is presented. Only surgical removal and subsequent histological examination allowed diagnosis while diagnostic investigation yielded no pathological findings.

5-HT1B receptor-mediated contractions in human temporal artery: evidence from selective antagonists and 5-HT receptor mRNA expression

1. In the human temporal artery both 5-HT1-like and 5-HT2A receptors mediate the contractile effects of 5-hydroxytryptamine (5-HT) and we have suggested that the 5-HT1-like receptors resemble more closely recombinant 5-HT1B than 5-HT1D receptors. To investigate further which subtype is involved, we investigated the blockade of 5-HT-induced contractions by the 5-HT1B-selective antagonist SB-224289 (2,3,6,7-tetrahydro-1'-methyl-5-[2-methyl-4'[(5-methyl-1,2,4-oxadiazole- 3-yl) biphenyl-4-yl] carbonyl] furo[2,3-f]indole-3-spiro-4'-piperidine oxalate) and the 5-HT1D-selective antagonist BRL-15572 (1-phenyl-3[4-3-chlorophenyl piperazin-1-yl] phenylpropan-2-ol). We also used RT-PCR to search for the mRNA of 5-HT1B, 5-HT1D and other 5-HT receptors. 2. The contractile effects of 5-HT in temporal artery rings were partially antagonized by SB-224289 (20, 200 nM) (apparent KB = 1 nM) and ketanserin (1 microM) but not by BRL-15572 (500 nM). 3. Sumatriptan evoked contractions (EC50, 170 nM) that were resistant to blockade by BRL-15572 (500 nM) but antagonized by SB-224289 (20, 200 nM). 4. The potency of 5-HT (EC50) was estimated to be 94 nM for the ketanserin-sensitive receptor and 34 nM for the SB-224289-sensitive receptor. The fraction of maximal 5-HT response mediated through SB-224289-sensitive receptors was 0.20-0.67, the remainder being mediated through ketanserin-sensitive receptors. 5. We detected arterial receptor mRNA for the following receptors (incidence): 5-HT1B (8/8), 5-HT1D (2/8), 5-HT1F (0/4), 5-HT2A (0/8) 5-HT2B (0/8), 5-HT2C (0/8), 5-HT4 (4/8) and 5-HT7 (4/8). 6. We conclude that the ketanserin-resistant fraction of the 5-HT effects and the effects of sumatriptan are mediated by 5-HT1B receptors. The lack of antagonism by BRL-15572 rules out 5-HT1D receptors as mediators of the contractile effects of 5-HT and sumatriptan.

Hangman's fracture: arguments in favor of surgical therapy for type II and III according to Edwards and Levine

BACKGROUND

The optimal therapy for traumatic fractures of the neural arch of the axis, the so-called hangman's fractures, is still controversial. Indications for surgery depend on the type of hangman's fracture and/or additional injuries of the intervertebral disc or ligaments.

METHODS

Sixteen patients sustaining fractures of the neural arch of the axis were treated by the screw fixation technique evolved by Judet. The passive mobility of the cervical spine was analyzed postoperatively by the radiographic evaluation method of Dvorak and coworkers and Penning. The angulation and anterior translation of C2 on C3 was measured before and after surgery.

RESULTS

Follow-up investigations 3, 12, and in some cases 45 months later confirmed sufficient functional results especially regarding the mobility of the upper cervical spine. Comparison of pre- and postoperative angulation and anterior translation of C2 on C3 revealed a significant improvement especially in cases with type IIa fractures.

CONCLUSION

The stabilization technique of Judet facilitates an exact reconstruction of anatomical conditions thereby preserving the atlantoaxial rotational mobility. A negligible hypomobility of the C2-C3 segment was observed on average 18 months after surgery.

A new technique of dural closure--experience with a vicryl mesh

Treatment of postoperative dural CSF leaks following posterior fossa surgery remains a difficult and often perplexing problem. Their management includes either non-operative management or surgical re-exploration. In order to avoid CSF leaks we developed a simple but effective method using a well-cut sheet of a vicryl-poly-p-dioxanone mesh (Ethisorb) covering the whole defect of the craniectomy. This paper presents our technique of dural closure, experiences with and advantages of the vicryl mesh in comparison with conventional procedures using muscle patches in combination with fibrin sealant or fibrin glue alone. Attention is focused upon the frequency of postoperative complications, in particular infection rate and CSF leaks. Furthermore, histomorphological observations after implantation of a vicryl mesh are demonstrated. In conclusion, due to its specific qualities we consider the vicryl mesh as a suitable dural substitute with potential advantages over currently used material.

Focal neurologic deficits in infective endocarditis and other septic diseases

INTRODUCTION

Focal neurologic deficits in sepsis frequently result from parenchymal lesions due to cerebral embolism. The aim of this study was to characterize clinical, laboratory and radiologic patterns of those patients.

PATIENTS AND METHODS

Medical records of 30 patients with focal neurologic symptoms during sepsis were analyzed retrospectively.

RESULTS

24 patients (22 with infective endocarditis) had ischemic stroke. Cerebrospinal fluid (CSF) analyses revealed inflammation in 11 of 12 patients. Patients who died (11/24) suffered more frequently from secondary intracerebral hemorrhage (p = 0.0031), which was significantly associated with intravenous high-dose anticoagulation (p = 0.0059). Six patients had slowly progressive focal neurologic deficits without evidence for stroke. All showed CSF inflammation and three developed multiple cerebral abscesses.

CONCLUSIONS

There are two distinctive groups of patients with focal neurologic deficits during sepsis. One presents with stroke and CNS inflammation (septic embolic focal encephalitis). The other group develops slowly progressive focal neurologic deficits and sometimes multiple cerebral abscesses (septic metastatic focal encephalitis).

Immunoscintigraphy for the detection of brain abscesses

The aim of this prospective study was to assess the diagnostic usefulness of a 99Tcm-anti-granulocyte antibody in the early differentiation of the aetiology of a ring-enhancing structure on computed tomography (CT) scans following neurosurgical intervention. In 26 patients (15 males, 11 females) aged 20-82 years with suspected intracranial infection, 29 SPET scans of the head were obtained 4-6 h following the intravenous injection of 555 MBq 99Tcm-anti-granulocyte antibody. The patients had antibiotic, antimycotic or corticosteroid therapy. The diagnosis was confirmed by surgery (19 cases) or subsequent CT/MRI (magnetic resonance imaging) scans and clinical follow-up (10 cases). The immunoscan was true-positive (abscess) in 6 (sensitivity = 100%), true-negative in 19 and false-positive in 4 (specificity 83%) cases. There was no obvious detrimental effect on the results due to the antibiotic, antimycotic or corticosteroid therapy. In conclusion, despite false-positive results, the 99Tcm-anti-granulocyte antibody is a useful tool in the early detection and exclusion of intracranial abscess after neurosurgical interventions.

Atypical and malignant meningiomas: evaluation of different radiological criteria based on CT and MRI

The following are our results of a retrospective analysis of 214 patients, operated on meningiomas, in order to investigate radiological criteria of malignancy. Among these cases there were 31 patients with a histologically confirmed diagnosis of malignant subtypes. As uncertain signs of malignancy of ensuing radiological features are an irregular enhancement of contrast-media and the size of cerebral edema. Based upon CT and MR images we have developed a standardised, computerised evaluation method which enables us to study in detail the internal architecture of meningiomas.

Symptomatology, surgical therapy and postoperative results of sphenoorbital, intraorbital-intracanalicular and optic sheath meningiomas

A series of 7 patients with optic sheath meningiomas, 3 intracanalicular and intraorbital, 2 intraosseus meningiomas of the sphenoid wing involving the optic canal, and 4 sphenoorbital meningiomas were reported. The choice of a surgical approach to the orbit was appropriate to the location and size of the tumour relative to the optic nerve. The most common complaints were proptosis, reduction of visual acuity and paresis of eye muscles. Patients with optic sheath meningiomas are threatened postoperatively by visual loss whereas the high recurrence rate has to be taken into consideration in cases of sphenoorbital meningiomas.

Participation of 5-HT1-like and 5-HT2A receptors in the contraction of human temporal artery by 5-hydroxytryptamine and related drugs

1. We investigated the hypothesis that, as in some other large human arteries, 5-HT-induced contraction of the temporal artery is mediated through two co-existing receptor populations, 5-HT1-like- and 5-HT2A. Temporal arterial segments were obtained from patients undergoing brain surgery and rings prepared set up to contract with 5-HT and related agents. Fractions of maximal 5-HT responses mediated through 5-HT1-like and 5-HT2A receptors, f1 and f2 = 1-f1, were estimated by use of the 5-HT2A-selective antagonist ketanserin. 2. In rings with intact endothelium 5-HT evoked contractions with a -log EC50, M of 7.0. Ketanserin (10-1000 nM) antagonized part of the 5-HT-induced contractions. Ketanserin-resistant components of 5-HT-induced contractions were found with -log EC50, M of 6.9 and f1 of 0.17 (100 nM ketanserin) and -log EC50, M of 6.4 and f1 of 0.20 (1000 nM ketanserin). 3. In rings with endothelial function attenuated by enzymatic treatment, 5-HT caused contractions with a -log EC50, M of 7.2 that were partially blocked by ketanserin. Ketanserin-resistant components of 5-HT-induced contractions were found with -log EC50, M 7.4 and f1 of 0.16 (100 nM ketanserin) and -log EC50, M of 7.5 and f1 of 0.14 (1000 nM ketanserin). 4. The ketanserin-resistant component of 5-HT-evoked contraction was blocked by methiothepin (100-1000 nM) consistent with mediation through 5-HT1-like receptors. 5. In rings with intact endothelium the 5-HT1-like-selective agonist, sumatriptan, caused small contractions with a -log EC50, M of 6.5 and intrinsic activity of 0.21 with respect to 5-HT that were resistant to blockade by 1000 nM ketanserin but antagonized by 100 nM methiothepin. 6. In rings with intact endothelium the 5-HT2A receptor partial agonist SK&F 103829 (2,3,4,5-tetrahydro-8[methyl sulphonyl]-1H3-benzazepin-7-ol methensulphonate) contracted rings with a -log EC50, M of 5.0 and an intrinsic activity of 0.49 with respect to 5-HT; the effects were antagonized by ketanserin 1000 nM. 7. We conclude that 80-86% of the maximum 5-HT-evoked contraction of human temporal artery is mediated through 5-HT2A receptors, the remainder through 5-HT1-like-receptors, regardless of whether or not endothelium is functional. The 5-HT1-like-receptors are more likely to be 5-HT1D beta receptors than 5-HT1D alpha receptors and sumatriptan is a full agonist for these receptors. As found in arteries of other species, SK&F 103829 is a partial agonist for 5-HT2A receptors of human temporal artery.

Intra- and paraventricular arteriovenous malformations: symptomatology, neuroradiological diagnosis, surgical approach and postoperative results

A series of 8 patients with para- and intraventricular arteriovenous malformations (AVM) is presented. Confirmed by histopathological examination or based upon their history all of them sustained recurrent intraventricular or intracerebral haemorrhages. Our results strongly recommend a surgical removal of these AVMs as a feasible and mandatory form of treatment. Conservative methods, e.g., embolisation or gamma beam irradiation leave the patient susceptible to rebleeding which often results in devastating neurological deficits. Total removal of the AVM with minimal surgical trauma was achieved in 7 patients under controlled hypotension and was facilitated by stereotactic guidance in two patients. Post surgical re-bleeding was not observed in any of our patients even though in one case only a subtotal resection of the angiomatous malformation was achieved. Based on our experience, we advocate an inspection of the lateral ventricle in order to avoid leaving any intraventricular portion of the vascular malformation behind. MRI investigation is recommended because the multiplanar images clarify the topographic-anatomic location and its relation to important surgical landmarks.

Fractures of the odontoid process: analysis of the functional results after surgery

Eighteen patients who sustained type II/III fractures of the odontoid process, as classified by Anderson and D'Alonzo [2], underwent anterior screw fixation, as described in detail by Böhler [4] as well as Grob and Magerl [16]. Follow-up investigations 3, 12 and in some cases up to 60 months later confirmed sufficient functional results regarding the mobility of the upper cervical spine. The passive mobility of the cervical spine was analyzed by the radiographic evaluation technique of Dvorak and co-workers [12] and Penning [26], which revealed a hypomobility of the C2-3 segment 1 year after surgery in 11 patients and a fusion of the C2-3 vertebral bodies in 2 cases. The postoperative results including the rate of complications were compared with other authors's findings and different therapy concepts (e.g., posterior C1-2 arthrodesis, halo-vest treatment).

Effect of naftidrofuryl on platelet-induced vasospasm in vitro. Role of antiserotonergic actions

This study was designed to analyse the spasmolytic actions of naftidrofuryl (Dusodril, CAS 31329-57-4) more in detail, using isolated vessel segments of bovine coronary arteries (BCA). In this preparation, naftidrofuryl caused a dose-dependent inhibition of 5-HT, U 46.619 ((5Z, 9a, 11a, 13E, 15S)-11,9-(epoxymethano) prosta-5,13-dienoic acid), PGF2 alpha and KCl-induced contractions. Additionally, the actions of naftidrofuryl on platelet-induced vasospasm were investigated using arachidonic acid (AA)-stimulated platelets and BCA. Naftidrofuryl antagonized the vasocontractile effects of secreted 5-HT, but was only slightly active in reducing the TXA2-dependent vessel contraction. The suppression of ADP-induced platelet aggregation and secretion required more than 300 mumol/l naftidrofuryl. These data support the concept of a spasmolytic activity of naftidrofuryl which also involves the antagonism of platelet-derived vasocontractile mediators.

Results of various methods to investigate the function of postmortem human and bovine basilar arteries

Cerebral vasospasm is a serious complication for patients suffering from acute nontraumatic subarachnoid hemorrhage (SAH). Despite numerous efforts to analyze the multifactorial pathomechanisms, it is still unclear whether vasospasm is a primary result caused by the release of vasoactive mediators or a secondary event due to severe destructions of the vessel architecture. This study was designed in order to investigate the reactivity of postmortem human basilar arteries upon exogenous vasoconstrictors, to study time-dependent changes in vessel morphology and to control responsiveness to agonists and selective antagonists. Therefore, isolated rings and spirally cut strips of bovine- and human basilar arteries were incubated with exogenous vasoconstrictors and specific antagonists (Daltroban, Ketanserin). Light and electron microscopic studies were performed in order to analyze the morphological changes in vessel tissues. Our results suggest that postmortem human basilar arteries are a suitable pharmacological tool studying the effects of contractile mediators.

The modification of platelet-induced coronary vasoconstriction by a thromboxane receptor antagonist

The role of platelet-derived vasoconstrictors in coronary vasospasm was studied using arachidonic acid-stimulated washed human platelets (WPS). Transfer of this system into an organ bath, containing bovine coronary arteries (BCA) and a mixture of blocking agents resulted in a biphasic contraction, consisting of a first phase, mediated by release of thromboxane (TX) A2 and a second phase, mediated by release of 5-hydroxytryptamine (5-HT) from the WPS (1,2). Treatment of the WPS with 4-[2-(benzenesulfonamido)-ethyl]-phenoxyacetic acid (BM 13.177) (0.03-3 mumol/L) prior to stimulation revealed a concentration-dependent inhibition of the 5-HT component of the contractile response with a minor reduction of the TXA2 component of contraction and enhanced amounts of immunoreactive TXB2 in the bath fluid. Treatment of the BCA with BM 13.177 prior to addition of stimulated WPS resulted in a significant reduction of the TXA2 component of contraction, by 56% at 30 mumol/L whereas 3 mumol/L were ineffective. The 5-HT component of contraction was enhanced. For comparison, the IC50 for BM 13.177 to inhibit PGF2 alpha-induced contractions was 6 mumol/L and that to inhibit U-46,619 was 0.5 mumol/L. BM 13.177 was at least 1 order of magnitude more potent as an inhibitor of U-46,619 than of PGF2 alpha- or TXA2-induced contractions. It is concluded that BM 13.177 is a weak inhibitor of TXA2-mediated contractions of coronary vessels, suggesting different thromboxane receptors in coronary vessels and platelets.

Prostacyclins are only weak antagonists of coronary vasospasm induced by authentic thromboxane A2 and serotonin

The actions of prostacyclin and its synthetic analog iloprost on the release and action of platelet-derived serotonin (5-HT) and thromboxane (TX) A2 were studied in vitro. Washed human platelet suspensions (WPS) (4 X 10(8) platelets/ml) were stimulated with arachidonic acid (AA) (30 mumol/L) and the incubate transferred into an organ bath containing bovine coronary arteries (BCA) in Krebs-Henseleit buffer supplemented with a mixture of blocking agents, including indomethacin. This resulted in a biphasic contraction of the coronary arteries, consisting of first, a TXA2-mediated response and second, a 5-HT-mediated response. The 5-HT-mediated reaction was dose-dependently inhibited by methysergide (IC50: 80 nmol/L). Treatment of the WPS with prostacyclin (PGI2) or iloprost prior to stimulation by AA resulted in a dose-dependent inhibition of the 5-HT-mediated contraction, due to inhibition of 5-HT release. The TXA2-mediated component, as well as the concentration of immunoreactive TXB2 in the bath medium, remained unchanged. Addition of PGI2 or iloprost to the BCA prior to transfer of stimulated WPS to the bath medium was followed by a dose-dependent inhibition of both phases. This, however, required concentrations of 100 nmol/L 5-HT and greater than 300 nmol/L TXA2 (IC50), which already produced a nearly complete direct relaxation of the vessel preparations (EC50: 30 nmol/L). It is concluded that a significant spasmolytic action of prostacyclins against platelet-derived vasoconstrictors in vivo might only be obtained at concentrations that already produce considerable direct effects on vessel tone.