Development of a loop-mediated isothermal amplification assay for rapid detection of Burkholderia mallei.

The present study was conducted to establish a Loop-mediated isothermal amplification (LAMP) technique for the rapid detection of B. mallei the etiologic agent of glanders, a highly contagious disease of equines. A set of six specific primers targeting integrase gene cluster were designed for the LAMP test. The reaction was optimized using different temperatures and time intervals. The specificity of the assay was evaluated using DNA from B.pseudomallei and Pseudomonas aeruginosa. The LAMP products were analyzed both visually and under UV light after electrophoresis. The optimized conditions were found to be at 63ºC for 60 min. The assay showed high specificity and sensitivity. It was concluded that the established LAMP assay is a rapid, sensitive and practical tool for detection of B. mallei and early diagnosis of glanders.

[Carotid dissection with cerebri media thrombosis due to a tonsillar lesion]. / Karotisdissektion mit Cerebri-media-Thrombose nach Tonsillenverletzung.

A 7-year-old boy suffered a tonsillar lesion due to trauma and presented to hospital with a GCS of 15. Some hours later he developed hemiparesis with loss of consciousness. Angiography displayed a left-sided carotid dissection associated with thrombosis of the arteria cerebri media. After initial treatment by heparinization, the increase of intracranial pressure was treated by craniectomy. The neurological deficits diminished partially after days and reimplantation of the skull cap was possible. The initial hemiparesis decreased slightly during rehabilitation after 5 weeks.

[Carotid artery dissection with cerebral infarction after soft tissue trauma in the pharyngeal region]. / Karotisdissektion mit Mediainfarkt nach Weichteiltrauma im Bereich des Pharynx.

We report the case of an 8-year-old boy who suffered an internal carotid artery dissection as a result of an enoral soft tissue trauma. After an initial interval with minor symptoms he developed a cerebral infarction in the vascular region of the left middle cerebral artery. The patient was treated with decompression hemicraniectomy while therapy was monitored with intracranial pressure (ICP) measurements.

Current status and future challenges in cerebral blood flow mapping in intracranial tumors.

CBF studies have been applied in patients with cranial tumors using XenonCT in order to evaluate the blood flow of both the tumor and the peritumoral brain tissue. The histology included mostly meningiomas or gliomas, less frequently neurinomas or metastases. Blood flow was determined in tumor tissue (TBF), peritumoral areas (PTBF) and cerebral hemispheres (hCBF). The CBF was compared to normative CBF values. In supratentorial tumors characteristical blood flow patterns were found according to the histology. PTBF was usually lower in edematous tissue than in normal brain tissue. TBF in malignant gliomas revealed a heterogeneous pattern with a central core of low flow and a peripheral zone with high flow. Global CBF values in patients with malignant gliomas were lower than in controls. Meningiomas showed significantly higher blood flow compared to gliomas or neurinomas. In some cases with large cerebellopontine angle tumors a reduction in brain stem blood flow was detected. In cavernous sinus tumors with carotid artery compression CBF and cerebrovascular reserve capacity was not impaired. These findings indicate that tumor induced alterations in cerebral circulation can be detected by CBF mapping. This diagnostic tool offers a further insight into perfusion related tumor pathophysiology and may thereby optimize individual neurooncological treatment strategies.

CBF determination in brain stem and cerebellar hemispheres.

CBF of brain stem and cerebellar hemispheres is of particular significance in different cranial diseases and can be determined by PET, SPECT and XenonCT. We have used XenonCT CBF method to study 78 patients with posterior fossa tumors or cerebrovascular disorders. A retrospective analysis of the first 56 CBF studies showed that bone artifacts were the most common cause of study failure. Based on these experiences we have developed a protocol to study brain stem and cerebellar blood flow. Because bone artifacts significantly degrade flow information, we obtained images over the petrous bone with a CT gantry angle of approximately 25 degrees to the orbitomeatal line. The failure rate could be reduced from 41% to 13% with this study protocol. Brain stem blood flow determination may help to clarify the prognosis in head trauma patients and show more physiological details in tumors of the posterior fossa. The phenomenon of crossed cerebellar diaschisis in cerebral insults or neoplasms can be investigated by XenonCT easily.

Xenon/CT CBF measurements as valuable diagnostic tool in a case of bilateral occlusive cerebrovascular disease associated with intracranial aneurysm.

A patient with the coincidental occurrence of a right internal carotid artery (ICA) stenosis and asymptomatic ipsilateral infraclinoidal ICA aneurysm is presented. CBF measurements including testing of the cerebrovascular reserve capacity (CRC) demonstrated a compromise of cerebral blood flow (CBF) within the anterior circulation of the affected side. We treated the patient in one operation by aneurysm clipping and subsequent carotid endarterectomy (CEA). 10 months later she presented with an occlusion of the contralateral ICA. CBF measurements showed sufficient resting flow and CRC on both sides. One year later repeat measurements disclosed a lowered resting CBF and diminished CRC on the affected side. Extracranial/Intracranial (EC/IC) artery bypass improved both symptoms and CBF/CRC values. The authors propose to treat symptomatic ICA stenosis and concurrent silent ipsilateral intracranial aneurysms at once if the patient is eligible for aneurysm surgery. CBF measurements should be performed before surgery. In a medically compromised patient carotid endarterectomy alone appears to be justifiable. In cases of symptomatic aneurysm and concurrent ICA stenosis a CEA can be added to aneurysm clipping to improve the hemodynamic situation for a better postoperative management. Xenon/CT investigations are suitable to provide important cerebral blood flow information. Together with angiography and clinical judgment it allows to identify patients with hemodynamic insufficiency. These are suitable candidates for an operative procedure to augment cerebral blood flow and to improve symptoms.

Alteration of rCBF in skull base lesions.

Cerebral functional imaging methods provide complementary information on brain function and large vessels regulatory controls which are compromised in cranial base lesions. The presence of a skull base tumor can alter regional cerebral blood flow (rCBF) in adjacent and remote brain tissue. This report presents the results of 104 CBF studies in 66 patients with skull base lesions (aged 17-75 years). The lesions included 36 meningiomas, 21 neurinomas and 9 other tumors. Regional CBF in tumor and brain tissue was measured prior to treatment using stable xenon enhanced computed tomography (Xenon(/T). For the quantitative analysis, regions of interest were delineated on tumor regions, cerebral and cerebellar hemispheres including peritumoral regions. In order to assess the remote effect of cerebellopontine angle (CPA) tumors, the brainstem, cerebellar, and cerebral blood flow were measured in 26 cases. The average brainstem CBF for patients with good outcome was higher than the average brainstem CBF for patients with poor outcome. This indicates that CBF studies in posterior fossa can be useful in predicting the prognosis of CPA tumor patients. We report a series of 16 patients with cavernous sinus tumors in whom the internal carotid artery was affected by the tumor. In nearly all cases Xenon/CT CBF studies with acetazolamide test showed no significant difference in hemispheric perfusion and a sufficient cerebrovascular reserve capacity. Interhemispheric asymmetry was present only in one patient. These results possibly indicate that i.v. administration of acetazolamide might contribute in selecting patients with higher risk for ischemic deficits after cavernous sinus surgery. Skull base meningiomas showed very high blood flow with a wide range. Local CBF in the peripheral region of meningiomas was higher than in the central region. Blood flow values in the peritumoral areas are about 30% lower than those of the ipsilateral hemisphere. In individual cases, blood flow values in the peritumoral low-density area on CT were extremely low. It is concluded that CBF studies in skull base tumors are valuable in treatment planning. Xenon/CT can be useful additional diagnostic procedure in the evaluation of skull base surgery candidates.

Immunohistochemical detection of female sex hormone receptors in meningiomas: correlation with clinical and histological features.

Sixty-one meningiomas from 60 patients were screened for estrogen receptors and progesterone receptors (PgR) with monoclonal antibodies in an immunohistochemical assay. In addition, 43 of the cases were evaluated for tumor size and peritumoral edema, as seen on computed tomographic scans and magnetic resonance images. Sixty-one percent of the tumors contained significant amounts of PgR, whereas no estrogen receptor-positive tumor was observed. Thirteen percent of all tumors were classified as nonbenign variants (atypical and anaplastic meningiomas) and were more frequently found in male patients (P < 0.05). Nonbenign tumors more frequently showed an absence of PgR (P < 0.05), and there was a tendency for PgR-negative tumors to be larger than PgR-positive ones. No correlation was found between PgR status and edema. It is concluded that PgR status in meningiomas is related to tumor differentiation and may be of prognostic value with regard to biological behavior and clinical outcome.

Peritumoral blood flow in intracranial meningiomas.

Blood flow was measured in intratumoral tissue, the cerebral hemispheres and particularly in the peritumoral area of 12 patients with intracranial meningiomas using the stable xenon-enhanced computed tomographic scan. Tumor blood flow frequently showed a heterogeneous pattern of enhancement with high flow at the tumor periphery and a central area of hypoperfusion. Blood flow values were on average 28% lower in the peritumoral area than in the ipsilateral cerebral hemisphere. In individual cases, blood flow values in the peritumoral edematous area were very low. These findings suggest that the hypodense area surrounding meningiomas does not solely represent vasogenic edema, but may actually represent tumor pressure ischemia.

Primary intraosseous meningiomas of the skull base.

Four cases of primary intraosseous meningiomas were seen among 373 cases of intracranial meningiomas operated upon in the Neurosurgical Clinic of the Krankenhaus Nordstadt, Hannover, FRG between January 1978 and December 1988. These 4 cases represent 1% of all intracranial meningiomas. Patients' age ranged between 21 and 66 years; 2 were females and 2 males. Presenting symptoms were localized orbital pain in 1 case, protrusion of the eye in 1 patient, pain in the orbit and forehead and protrusion of the eye in 1 patient, and peripheral facial palsy in 1 case. Symptoms lasted between 3 and 10 years. Two tumours were in the bony orbit, 1 in the bony orbit and in the frontal bone and 1 in the temporal bone. All tumours were surgically completely removed. All patients are clinically and computer tomography free of tumour 1 to 8 years after the operation.

Transient mutism following removal of a cerebellar tumor. A case report and review of the literature.

A 14-year-old boy developed mutism 24 h after the removal of a vermian low-grade astrocytoma. The mutism was not accompanied by long tract signs or cranial nerve palsies. He started to regain his speech 3 weeks postoperatively, and 4 months after the operation he was minimally dysarthric. Seven similar cases of transient muteness following cerebellar operations and not accompanied by long tract signs or cranial nerve palsies have been reported in the literature. In most of them there was delayed postoperative onset of the mutism. In all patients the recovery of speech started to appear 2 weeks to 3 months postoperatively and passed through a dysarthric phase. The absence of long tract or other brain stem signs, together with the presence of dysarthria during the recovery of speech, suggests a cerebellar cause for the transient muteness.

Vertebral arteriovenous fistulae. Report of two cases and review of the literature.

Two patients with vertebral arteriovenous fistulae were treated at the Neurosurgical Clinic of the City Hospital of Hannover between 1981 and 1988. Both patients were males, 19 and 29 year old. The fistulae were secondary to cervical gunshot wounds. Both patients complained of a loud cephalic noise; 1 patient had a non pulsating neck mass. A systolic cervical bruit was heard in both cases. One patient had an incomplete mid-cervical Brown-Sequard syndrome. The fistulae involved the second portion of the vertebral artery: 1 fistula was fed, in addition to the vertebral artery, by the deep cervical artery. Venous drainage was through intraspinal plexus, vertebral vein, deep cervical veins and internal jugular vein. One patient was treated with a direct surgical trapping of the vertebral artery proximal and distal to the fistula: the other patient, in addition to direct surgical vertebral artery trapping, received an endovascular balloon occlusion of the deep cervical artery. After treatment the fistulae disappeared, both clinically and angiographically.