A new formulae study for the (n,2p) reaction cross-section systematics at 14-15 MeV.

The cross-section calculation systematics for nuclear reactions have great importance in describing the particle-induced excitation of nuclei. In this study, for 14-15 MeV of incident neutron energy, it has been suggested new empirical formulae to describe the (n, 2p) reactions cross sections. The new empirical formulae have been obtained for 29≤A≤159, 29≤A≤103 and 133≤A≤159 mass ranges which are dependent on s=(N-Z)/A asymmetry parameter. The asymmetry parameters have been obtained by modifying the original Levkovski formula. Then, EXFOR data has been studied by applying the least square fitting method and (n, 2p) reactions systematics has been revealed. The statistical dependence (R2) of these data was examined in the 29≤A≤159 total mass range. The calculated results from the obtained formulae have been compared with the literature data. The predictions of our formulae are in good agreement with the EXFOR data for 29≤A≤159 and 29≤A≤103 mass range.

New calculation of excitation functions of proton-induced reactions in some medical isotopes of Cu, Zn and Ga.

The new calculations on the excitation functions of 61Ni(p,n)61Cu, 62Ni(p,n)62Cu, 64Ni(p,n)64Cu, 63Cu(p,2n)62Zn, 63Cu(p,n)63Zn, 65Cu(p,n)65Zn, 66Zn(p,n)66Ga, 67Zn(p,2n)66Ga, 67Zn(p,n)67Ga and 68Zn(p,n)68Ga reactions have been carried out in the 5-30 MeV proton energy range. The calculations involve the cascade exciton model, preequilibrium nuclear reaction model and exciton model. The calculated results are compared with the experimental data taken from the literature.

Effect of surgery on BCNU chemotherapy in a rat brain tumor model.

In Fischer 344 rats, 9L tumors were implanted in the left cerebral hemisphere. Compared with control animals not operated on, rats treated with an LD10 dose of BCNU 1 hour before or 1 or 12 hours after surgery on Day 16 postimplant had an increased life span of over 200% (greater than a 6 log cell kill). Minimal effect on survival was found when BCNU was administered during surgery. On the other hand, BCNU administered 12 hours before or 24 or 72 hours after surgery did not show any additive effect of surgery on BCNU treatment. These results suggest that in a clinical setting, a bolus of BCNU administered to tumor patients within 12 hours of surgery might increase substantially the total tumor cell kill compared with surgical resection alone.

Cerebral blood flow alterations in progressive communicating hydrocephalus: transcranial Doppler ultrasonography assessment in an experimental model.

OBJECT: In many cases communicating hydrocephalus is the result of impairments in cerebrospinal fluid absorption in the arachnoid villi at the cranial convexity. Reported methods of creating experimental hydrocephalus have not sought to produce an arachnoidal adhesion in the cranial convexity. In this study the authors investigate alterations in cerebral blood flow (CBF) in experimental communicating hydrocephalus induced by the injection of kaolin into the subarachnoid space at the convexity in neonatal rats. METHODS: In neonatal rats, kaolin was injected into the subarachnoid space at the cranial convexity. Assessment of CBF alterations was performed using transcranial Doppler ultrasonography preinjection and at 10 days, 4 weeks, and 8 weeks postinjection. Light microscopy examination was also performed at 4 weeks and 8 weeks postinjection. Conspicuous lateral ventricle enlargements of different dimensions were observed in kaolin-injected rats at 4 to 8 weeks postinjection. The third and fourth ventricles were dilated to a lesser extent. Resistance to CBF and increased mean CBF velocity were apparent 8 weeks after kaolin injection. Further, destruction and even loss of ependymal layers were more prominent at the chronic stage. CONCLUSIONS: The present model may be considered a progressive communicating hydrocephalus because of marked changes in blood flow dynamics and destruction of the ependymal layer at the chronic stage.

Antiproliferative properties of the lazaroids U-83836E and U-74389G on glioma cells in vitro.

The 21-aminosteroids (lazaroids) are a new family of steroid compounds that inhibit lipid peroxidation reactions. They are novel antioxidant agents, which have been shown to have antiproliferative properties on cancer cells and also are thought to prevent free radical-mediated blood-brain barrier damage. In order to understand the effect of lazaroids on glioma, we tested U-83836E and U-74389G at doses ranging between 0.1 100 m mM on primary cultures of glioblastoma multiforme from three patients, rat C6 glioma cell line, and 5 th subculture established from one of the patients. The effects of both compounds on cell proliferation were determined using 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay. U-83836E in the primary cultures was found to have 50% inhibitory concentrations (IC50 ) of 6.30, 6.75 and 6.50 m mM, respectively. The IC50 value of U-74389G was calculated as 91 m mM in only one of the patients. On C6 glioma cells, while the IC50 of U-83836E was 45 m mM, U-74389G showed no cytotoxic effect. On the 5 th subculture, U-83836E had an IC50 of 37.5 m mM, but the cytotoxic effects of U-74389G was less than in that of the primary culture. In conclusion, these compounds were found to be more cytotoxic in primary culture than the cell lines and there were also differences between their members in the inhibition of cell survival.

Spinal toxoplasmic arachnoiditis associated with osteoid formation: a rare presentation of toxoplasmosis.

STUDY DESIGN: An extremely rare presentation of an isolated spinal toxoplasmic arachnoiditis is described. OBJECTIVE: To draw attention to the fact that spinal arachnoid membranes may be a potential reservoir for Toxoplasma gondii. SUMMARY OF BACKGROUND DATA: Central nervous system toxoplasmosis is a common manifestation in patients who are immunodeficient. Reports on the spinal toxoplasmosis are rare and focused on spinal cord involvement. METHODS: An adult patient presented with symptoms of spastic paraparesis that had begun 13 years before admission. Thoracic spinal magnetic resonance imaging showed small lesions in posterior subarachnoid space at Th7-Th8. A Th7-Th8 laminectomy was performed. Intradural-extramedullary lesions were excised. RESULTS: Clinical, immunologic, and pathologic examinations showed adhesive spinal arachnoiditis associated with osteoid formation caused by past toxoplasmic infection. There was no impairment of the immunologic defense system. CONCLUSION: Where no causative factor is found in serious spinal adhesive arachnoiditis, the possibility of spinal toxoplasmosis should also be investigated.

Cerebellar metastasis from clear cell sarcoma of the kidney. A case report with immunohistochemistry.

The aim of this study was to describe a child with a right cerebellar hemisphere metastasis from primary clear cell sarcoma of the kidney without evidence of bone metastases, and to investigate the immunohistochemical features of primary and metastatic tumors. A 12-month old boy was admitted our hospital due to an abdominal mass. Abdominal computed tomography revealed a large right renal tumor. Tumor was removed with nephrectomy. Histopathologic examination of tumor revealed clear cell sarcoma of the kidney. The patient received radiotherapy and chemotherapy in postoperative period. He suffered from gait disturbance and confusion 8 months later. A computed tomography scan revealed a tumor that was enhanced with contrast medium at right cerebellar hemisphere concomitant with ventricular enlargement. After ventriculo-peritoneal shunting procedure, tumor was excised totally and histopathologic diagnosis showed metastasis of clear cell sarcoma of the kidney. Immunohistochemically vimentin, actin, desmin, neuron specific enolase, cytokeratin, P 53, Ki-67 and P-170 were performed using formalin fixed, paraffin embedded sections. Both of the tumors were positive for vimentin and negative for desmin, actin, neuron specific enolase, cytokeratin and P 53. Scattered nuclei were stained by Ki-67 in primary and metastatic cerebellar tumor. Both primary and metastatic tumors were negative for p53 and P-170. The treatment consisted of surgery, radiotherapy and chemotherapy. The patient is alive and well without evidence of recurrence 16 months after second surgery. Clear cell sarcoma of the kidney is most commonly associated with bone metastasis. Cerebellar metastasis of clear cell sarcoma of the kidney is very unusual. To the best of our knowledge, this patient is second case in the English literature. With review of the literature, our immunohistochemical findings support the theory that relapse and metastasis of primary clear cell sarcoma of the kidney are not related with increase of aggressiveness.

Non-hindbrain-related syringomyelia. Obstruction of the subarachnoid space and the central canal in rats. An experimental study.

BACKGROUND: The aim is to determine the mechanism of non-hindbrain-related syringomyelia in experimental models. The effects of obstruction of central canal and subarachnoid space on occurrence of cavities were discussed. METHODS: 31 Sprague-Dawley rats were used with eight (Group D) as a control. In 10 rats (Group A) 1.5 microl kaolin was microinjected into the dorsal columns and central gray matter of the spinal cord at the level of Th6-10. In 10 rats (Group B) 0.1 cc kaolin was injected into the subarachnoid space at the same level. In 3 rats (Group C), 1.5 microl kaolin was administered into both dorsal midline of the spinal cord and the subarachnoid space. RESULTS: In Group A, histological examination revealed cystic cavity and dilatation of the central canal in five rats; denuded ependymal line and multicystic formations in ependymal and periependymal areas in seven rats. In Group B, denuded ependymal line in three rats and microcystic formations in ependymal and periependymal areas in four rats were revealed. In Group C, there were microcystic formations in two rats and syrinx cavity in one rat. CONCLUSIONS: Developments leading to occurrence of cavities are focused on the central canal in all groups. These models indicate that the CSF-flow is from the subarachnoid space to the central canal leading to changes of cavities. In cases of obstruction of the subarachnoid space or the central canal, the occurrence of syrinx cavity initially is due to increased CSF (cerebrospinal fluid) pressure in the central canal. Flow changes in spinal cord is indicated by this study.

Instrumentation for posterior stabilisation of cervical traumatic and degenerative disorders: bullet-shaped implant and titanium cable.

BACKGROUND: Numerous implants for posterior stabilisation of cervical spine have been described so far. The aims of all these implants and techniques are rigid spinal stabilisation without neurologic damage, restoration of neuroanatomy and excellent radiological studies in postoperative period. The objective of this study was to determine the effectively and clinical safety of this system. METHODS: We conducted a retrospective analysis of patients treated with posterior stabilisation system for the stabilisation of traumatic and osteodegerative disorders of lower cervical spine in our department. This posterior cervical stabilisation system consist of titanium bullet-shaped implant (Ti-Frame) and titanium cables (sof' wire). RESULTS: All patients underwent only posterior fixation except 2 (anterior decompression and posterior stabilisation in 2 stages) and postoperative early immobilisation was allowed with Philadelphia collar in all patients. At the follow-up period 15.2 months (9-25 months), none of the patients had superficial or deep infection, implant resection or failure. CONCLUSIONS: In conclusion, this system (Ti-frame and titanium cables) is a simple, safe and effective system for posterior cervical stabilisation in patients with traumatic and osteodegenerative disorders due to provide rigid fixation and allow CT and MR imaging without the significant artifact.

Management of glioblastoma multiforme: with special reference to recurrence.

Between 1985 and 1995, 46 patients underwent craniotomy for glioblastoma multiforme. The mean age was 47, varying from 9 to 71 years. The influence of such prognostic factors as age, preoperative Karnofsky score, extent of resection, tumour site, tumour size, radiotherapy, reoperation as well as initial symptoms upon survival were studied. Of these, gross complete removal, radiotherapy, preoperative Karnofsky score, and reoperation were shown to be statistically significant to the survival time according to logrank and univariate tests. However, age, preoperative Karnofsky score, tumour size and temporal localisation remained as significant factors in multivariate analysis. The overall median survival was 53 weeks, with no patients surviving more than 3 years. Of the patients, 41% survived over a year and 8.6% lived over two years. Twenty-six patients developed a recurrent mass after an interval of 32 weeks. The median interval time from operation to recurrence was longer in those patients who underwent gross removal than in those who had a subtotal resection, 28.2 against 20 weeks (P < 0.05). Of patients who had a recurrent mass, 16 were reoperated on, with a subsequent median survival time of 26.5 weeks. Our experience suggests that the survival of patients with glioblastoma depends on many factors, including radical surgery as an initial step. In addition, the gross total removal of the tumour also delays the development of recurrence.

The deletion of 22q13 region in both intracranial and spinal meningiomas in a patient (case report).

We present a 69 year old man with two simultaneous meningiomas in different compartment of neural axis, in both of which 22q13 locus is lost. Histologically the two tumours appeared to be different; meningotheliomatous and transitional with psammoma bodies, respectively. No numerical or structural chromosome abnormalities were seen in karyotype analysis of the cultured spinal and cranial meningioma samples. Since long arm structural aberrations and/or whole loss of chromosome 22 are frequently reported abnormalities of meningiomas, the tumours were also analysed by fluorescence in situ hybridisation (FISH) with different colour-labelled probes in respect to relevant chromosome. The metaphases and interphase nuclei of the samples were evaluated by the combined biotinylated 22q11 and digoxigenin-labelled 22q13 locus specific FISH probes, and 22q13 deletion was revealed in both of spinal and cranial tumour cells. In conclusion, since both tumours from the presented case show the same genetic alterations, multiplicity may be derived from the same clone of cells, and support the theory of development of multiple meningiomas from the spreading of tumour cells via cerebrospinal fluid as a possible mechanism.

Multiple nocardial abscesses of cerebrum, cerebellum and spinal cord, causing quadriplegia.

In this paper we present a case of a diabetic patient with nocardial abscesses of cerebrum, cerebellum and the spinal cord. The present case is the first case in the literature of solitary intramedullary abscess in cervical spinal cord, causing tetraplegia. Nocardia asteroides grew in a culture of the abscess pus. After either surgical excision or drainage of lesions, a triple combination regimen of chemotherapy (amikacin, ceftriaxone and trimethoprim-sulfamethoxazole) was given, but the patient was lost in the postoperative period. This case gives suggestive evidence of an association between cervical spinal cord involvement and poor prognosis in CNS nocardiosis.

The effects of anticancer drugs in combination with nimodipine and verapamil on cultured cells of glioblastoma multiforme.

The presence of the cellular multidrug resistance (MDR1) gene and its product, P-glycoprotein (Pgp), is thought to be a mechanism for the failure of chemotherapy in cancer patients. Calcium channel blockers have been shown to sensitise cancer cells to anticancer drugs by reversing Pgp expression in cell lines. The interactions between anticancer drugs such as carmustine (BCNU), vincristine (VCR) and procarbazine (PCB) and calcium channel blockers such as nimodipine and verapamil on cultured cells of glioblastoma from eight patients were therefore tested. Pgp expression was examined immunohistochemically using C219 monoclonal antibody in cytospin preparation. The cytotoxicity of the drugs was screened using microculture tetrazolium assay. The cells from five patients showed positive immunoreaction for Pgp. Nimodipine showed growth-inhibitory activity against glioblastoma cells at a rate of 16.55-26.88% (P < 0.05), but a similar effect was not observed with verapamil. While antiproliferative effects of BCNU were around 20.91-45.09% (P < 0.05) on the cells from seven patients, VCR was the most effective agent in inhibition of cell growth at a rate of 26.43-48.47% (P < 0.05). The response of the cells from five patients to PCB was from 11.98 to 16.32% (P < 0.05). When used together, nimodipine further enriched cytotoxicity of the anticancer drugs up to 11.14-40.85% (P < 0.05) without relation to Pgp expression. In conclusion, the enhancement of cytotoxicity of anticancer drugs by nimodipine suggests that there might be a synergy between anticancer drugs and nimodipine in the inhibition of glioma cell growth.

The effects of MK-801 and U-83836E on post-ischemic reperfusion injury in rat brain.

Rats were subjected to incomplete cerebral ischemia induced by occlusion of common carotid arteries for 30 min, and subsequent reperfusion for 15 min. The concentrations of reduced glutathione (GSH), malondialdehyde (MDA) and superoxide dismutase (SOD) activity were determined in the dorsal hippocampus in order to evaluate their changes during ischemia and reperfusion following ischemia. The depletion of GSH was observed during ischemia with a further depletion during post-ischemic reperfusion (P < 0.001), while a significant increase in SOD activity and MDA levels was found only after reperfusion following ischemia (P < 0.001). Animals in which ischemia was followed by reperfusion were treated with a non-competitive NMDA receptor antagonist, MK-801 (1 mg/kg, i.v.), and a radical scavenger, U-83836E (5 mg/kg, i.v.), prior to ischemia. Although a full recovery of GSH levels was not observed following MK-801 and U-83836E pretreatment as compared to control (P < 0.05), MK-801 was more potent than U-83836E in the partial protection of the GSH pool (P < 0.05 and P < 0.01, respectively). The rise in SOD activity and MDA level were brought close to those of control due to the effects of both MK-801 and U-83836E (P > 0.05). In conclusion, the tissue changes in GSH concentrations evoked by ischemia and reperfusion were partially prevented by the effects of both drugs, MK-801 having the greater effect. This suggests that the NMDA receptor activation may play a role in the generation of reactive oxygen species. On the other hand, the inhibition of lipid peroxidation brought about by both MK-801 or U-83836E suggests the therapeutic efficiency of these agents in ischemia/reperfusion injury.

Indications of Philadelphia collar in the treatment of upper cervical injuries.

The principles of the management of upper cervical injuries remain controversial. The specific anatomical conditions render upper cervical injuries more problematic than lower cervical injuries. Here we present and discuss our experiences with upper cervical injury, comparing them with other treatment modalities. The 24 patients admitted to our department with upper cervical injury were treated surgically or conservatively according to their neurological and radiological status. Five patients were treated surgically due to neurological abnormality associated with compression to neural structures observed in computerized tomography/magnetic resonance imaging (CT/MRI). Patients with no neural compression were managed conservatively, with the Philadelphia collar. All patients showed stable fracture healing and experienced no additional clinical disability on follow-up after a minimum of 3 months, except one who died due to cardiac and respiratory failure. Regardless of the type of injury, indication for surgery in many cases of upper cervical injury is neurological abnormality associated with radiologically observed neural compression. It is our belief that, in the absence of both neurological abnormality and compression to neural structures observed in CT/MRI, treatment with the Philadelphia collar alone is safe, cost-effective and easily applicable for many cases of upper cervical injury.

Injury caused by deeply penetrating knife blade lodged in infratemporal fossa.

Knife-inflicted, deeply penetrating head and neck trauma is an uncommon life-threatening injury and a challenging problem. An examination of the neurovascular and systemic physical status is a first requirement and the decision as to which approach to adopt for the removal of the blade is of critical importance. Here we report a rare case of a pre-auricular stab wound with the knife blade deeply lodged in the extracranial infratemporal fossa. Radiological investigations showed that the knife blade had entered from the temporomandibular joint and become lodged through the anterior margin of foremen magnum below the petrosal bone. Minimal left vocal cord paresis, left palatal weakness and a slight deviation of the tongue towards the left side were observed. The other neurological and systemic physical evaluations were normal. Simple withdrawal of the blade in the operating room did not cause serious neurovascular injury. Here we discuss and compare the expanded exposure of anatomical structures for blade removal and simple withdrawal in similar injuries.

Luteinizing hormone releasing hormone increases proliferation of meningioma cells in vitro.

The fact that meningioma shows at least a 2:1 predilection for women over men is considered to be due to endocrinological and paracrine regulation of the development of this tumour. The presence of receptors for the luteinizing hormone releasing hormone (LHRH) in gynaecological cancer permits the use of LHRH agonistic or antagonistic analogues with a direct effect or by the gonado-pituitary axis suppression in the treatment of these tumours. Therefore, the effect of LHRH on meningioma cells is tested in this study. Meningioma cells from three female patients were cultured and LHRH (50 ng/ml) was added to the growth medium daily, for fourteen days. At the end of this period the cells were counted by means of a Coulter Counter. The stimulating effects of LHRH on the increase of the amount of cells in the meningioma monolayer culture were 146% (p < 0.01), 134% (p < 0.05) and 141% (p < 0.05) of the control, respectively, for the three patients.

Double meningocele. Case report.

The coexistence of two distinct meningoceles of the spine is a very unusual event. We report a three-day-old boy with double meningoceles at the thoracic and lumbar levels. The connection between the stalk of the thoracic meningocele and the spinal cord, as seen on magnetic resonance imaging, showed a neurological involvement in this lesion. Our case is only the third without association of congenital anomalies or neurofibromatosis to be reported to date.

Dynamic characteristics of central auditory neurons and their relation to selective-combination mechanisms of organization of brain functions.

Unit responses of the torus and caudal neostriatum of hens to stimuli of differing ecological significance (pure tones, white noise, species-specific stimuli) were investigated. The range of frequencies receivable by central auditory neurons was shown to correspond to the frequency composition of the stimuli emitted by the animals. Neurons selectively responding to species-specific stimuli (song, alarm signals) were found in the forebrain. The specific character of the functional organization at different levels of the auditory system is examined in the light of the selective-combination principle of stimulus integration, which may lie at the basis of the mechanism of both inborn and acquired memory.

Assessment of cerebral blood flow velocities in pre and post angiographic states with transcranial doppler.

The frequency of complications resulting from angiograms reported in the literature vary between 0.2-5 percent. This study was planned to determine the changes in cerebral blood flow velocity before and after angiography, using transcranial doppler in patients of subarachnoid hemorrhage (SAH) undergoing angiographies. Thirty patients with subarachnoid hemorrhage underwent transcranial doppler ultrasonography immediately before and after angiography. Nonionic water-soluble agents were used during the angiograms. The mean flow velocity (MFV) and pulsatility index (PI) at the M1 segment of both middle cerebral arteries was simultaneously measured. When the patients (11 male, 19 female, mean age+SD; 52.45+12.06) were compared according to changes in MFV and PI, pre and post-angiography, there was no statistical difference in MFV (p=0.51 and p=0.99, left and right side respectively), and in PI (p=0.48 and p=0.66) pre and post angiography. Although angiogram can be used to detect vasospasm in SAH, it can also be cause of vasospasm, partially due to the effect of the contrast agent on the cerebral arteries. This study proposes that the angiographic method is still safe and TCD can be used to follow up any possible changes in diameter of cerebral arteries before and after angiography.