NT-pro BNP level at dialysis initiation is a useful biomarker for predicting hospitalization for ischemic heart disease

BACKGROUND

Patients with end-stage kidney disease (ESKD) are at high risk of cardiovascular disease including stroke, heart failure, and ischemic heart disease (IHD). To prevent the occurrence and progression of CVD, a reliable prognostic cardiac biomarker is essential. We investigated the prognostic value of NT-proBNP for each incident type of CVD.

METHODS

Male patients from the Ibaraki Dialysis Initiation Cohort (iDIC) study with preserved serum samples from dialysis initiation day (n = 212) were analyzed. Patients were classified into four groups according to quartiles of baseline NT-pro BNP levels. The relationship between NT-proBNP levels at the initiation of dialysis and the subsequent incidence of hospitalization events due to IHD, heart failure, and stroke was analyzed.

RESULTS

The incidence rate for hospitalization due to IHD was significantly higher in the highest NT-proBNP category (Log rank p = 0.008); those of stroke and heart failure showed no significant differences among quartiles. Cox proportional hazards regression analysis revealed that serum NT-proBNT was the only prognostic factor for hospitalization for IHD after adjustment by major known IHD risk factors. (HR, 1.008; 95% confidence interval, 1.002-1.014; p = 0.01) The ROC curve analysis for the incidence of hospitalization due to IHD showed that NT-proBNP had an area under the curve (AUC) of 0.759 (95% CI 0.622-0.897; p = 0.004) at a cut-off value of 956.6 pg/mL.

CONCLUSION

NT-proBNP measurement at the initiation of dialysis therapy is useful to predict later hospitalization for IHD.

TRIAL REGISTRATION

UMIN000010806.

The Immunobiological Agents for Treatment of Antiglomerular Basement Membrane Disease

Combination therapy with glucocorticoids, cyclophosphamide, and plasmapheresis is recommended as the standard treatment for anti-glomerular basement membrane (anti-GBM) disease, but the prognosis of this disease remains poor. Several immunobiological agents have been administered or are expected to be useful for anti-GBM disease in light of refractory disease or the standard treatments' tolerability. Many data regarding the use of biologic agents for anti-GBM disease have accumulated, verifying the effectiveness and potential of biologic agents as a new treatment option for anti-GBM disease. Tumor necrosis factor (TNF) inhibitors were shown to be useful in animal studies, but these agents have no clinical use and were even shown to induce anti-GBM disease in several cases. Although the efficacy of the TNF-receptor antagonist has been observed in animal models, there are no published case reports of its clinical use. There are also no published reports of animal or clinical studies of anti-B-cell-activating factor, which is a member of the TNF family of agents. Anti-interleukin (IL)-6 antibodies have been demonstrated to have no effect on or to exacerbate nephritis in animal models. Anti-C5 inhibitor was observed to be useful in a few anti-GBM disease cases. Among the several immunobiological agents, only rituximab has been demonstrated to be useful in refractory or poor-tolerance patients or small uncontrolled studies. Rituximab is usually used in combination with steroids and plasma exchange and is used primarily as an alternative to cyclophosphamide, but there is insufficient evidence regarding the efficacy of rituximab for anti-GBM disease, and thus, randomized controlled studies are required.

Staphylococcus aureus Infection-Related Glomerulonephritis with Dominant IgA Deposition

Since 1995, when we reported the case of a patient with glomerulonephritis with IgA deposition that occurred after a methicillin-resistant Staphylococcus aureus (MRSA) infection, many reports of MRSA infection-associated glomerulonephritis have accumulated. This disease is being systematized as Staphylococcus infection-associated glomerulonephritis (SAGN) in light of the apparent cause of infection, and as immunoglobulin A-dominant deposition infection-related glomerulonephritis (IgA-IRGN) in light of its histopathology. This glomerulonephritis usually presents as rapidly progressive glomerulonephritis or acute kidney injury with various degrees of proteinuria and microscopic hematuria along with an ongoing infection. Its renal pathology has shown several types of mesangial and/or endocapillary proliferative glomerulonephritis with various degrees of crescent formation and tubulointerstitial nephritis. IgA, IgG, and C₃ staining in the mesangium and along the glomerular capillary walls have been observed on immunofluorescence examinations. A marked activation of T cells, an increase in specific variable regions of the T-cell receptor β-chain-positive cells, hypercytokinemia, and increased polyclonal immune complexes have also been observed in this glomerulonephritis. In the development of this disease, staphylococcal enterotoxin may be involved as a superantigen, but further investigations are needed to clarify the mechanisms underlying this disease. Here, we review 336 cases of IgA-IRGN and 218 cases of SAGN.

An Adult Patient with Alagille Syndrome Showing Mainly Renal Failure and Vascular Abnormality without Liver Manifestation

Alagille syndrome is an inherited multisystemic disorder. We herein report an atypical case of a Japanese adult patient with Alagille syndrome. He had been diagnosed with Alagille syndrome as an infant based on a liver biopsy. At 27 years of age, he needed to start hemodialysis therapy, but an arteriovenous fistula was not created because his peripheral blood vessels were too narrow. He also had a recurrent brain infarction due to cerebral vascular stenosis. Alagille syndrome is generally recognized as a pediatric hepatic disease, but general physicians should be aware of its potential existence with renal involvement and vascular abnormalities.

Serum 20S proteasome levels are associated with disease activity in MPO-ANCA-associated microscopic polyangiitis

Background

Proteasomes are found in both the cell nucleus and cytoplasm and play a major role in the ubiquitin-dependent and -independent non-lysosomal pathways of intracellular protein degradation. Proteasomes are also involved in the turnover of various regulatory proteins, antigen processing, cell differentiation, and apoptosis. To determine the diagnostic value of serum proteasome in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), we investigated patients with AAV at various stages of the disease.

Methods

Serum 20S-proteasome was measured by ELISA in 44 patients with MPO-ANCA-associated microscopic polyangiitis (MPA) and renal involvement. Thirty of the patients provided serum samples before the initial treatment, and 30 provided samples during remission; 16 provided samples at both time points.

Results

The mean serum 20S-proteasome level was significantly higher in the active-vasculitis patients (3414.6 ± 2738.9 ng/mL; n = 30) compared to the inactive-vasculitis patients (366.4 ± 128.4 ng/mL; n = 30; p <  0.0001) and 40 controls (234.9 ± 90.1 ng/mL; p <  0.0001). There were significant positive correlations between the serum 20S-proteasome level and the Birmingham Vasculitis Activity Score (BVAS) (r = 0.581, p <  0.0001), the ANCA titer (r = 0.384, p <  0.0001), the white blood cell (WBC) count (r = 0.284, p = 0.0042), the platelet count (r = 0.369, p = 0.0002), and the serum C-reactive protein (CRP) level (r = 0.550, p < 0.0001). There were significant negative correlations between the serum 20S-proteasome level and both the hemoglobin concentration (r = - 0.351, p = 0.0003) and the serum albumin level (r = - 0.460, p < 0.0001). In a multiple regression analysis, there was a significant positive correlation between the serum 20S-proteasome level and only the BVAS results (β = 0.851, p = 0.0009). In a receiver operating curve analysis, the area under the curve for the serum 20S-proteasome level was 0.996, which is higher than those of the WBC count (0.738) and the serum CRP level (0.963).

Conclusion

The serum level of 20S-proteasome may be a useful marker for disease activity in AAV.

Clinical course and pathological findings of two late-onset Fabry hemizygous patients including mulberry cell counts after enzyme replacement therapy

Fabry disease is an X-linked inherited lysosomal storage disorder caused by a deficiency of α-galactosidase A activity, resulting in the intracellular accumulation of globotriaosylceramide and related glycosphingolipids. The phenotypes of Fabry disease in both males and females are grouped into two categories: the classical type and the late-onset type. The classical type shows general symptoms including angiokeratoma(s), acroparesthesia, hypohidrosis, corneal opacity, and gastrointestinal symptoms from an early age. The late-onset type shows cardiac or renal (or both) symptoms from a late age. We present herein the clinical course and pathological findings of two late-onset hemizygous Fabry patients after the initiation of enzyme replacement therapy (ERT), along with their mulberry cell counts during treatment. One patient's case was a renal-variant type without general symptoms; he showed stable renal function and mild proteinuria but little histological improvement with no change in the mulberry cell count during ERT. The other patient had a cardiac-variant type with renal pathological abnormality. He achieved a mild improvement of renal pathological findings, and his mulberry cell count gradually decreased during the treatment. These findings indicate that monitoring the mulberry cell count might help assess the efficacy of ERT, as a renal pathology tool.

The relationship between serum magnesium levels and mortality in non-diabetic hemodialysis patients: A 10-year follow-up study

Introduction Recently, although there are many reports showing that serum magnesium concentration is a predictor of mortality in dialysis patients, the observation periods of those reports were of short duration, typically around 12 months. Thus, we investigated this relationship over a longer follow-up period. Methods This retrospective, observational study included a total of 83 non-diabetic hemodialysis patients. The follow-up period was 120 months. Patients were divided into two groups, those with serum magnesium ≥2.5 mg/dL (Mg ≥2.5 mg/dL group) and serum magnesium <2.5 mg/dL (Mg <2.5 mg/dL group), and Kaplan-Meier analysis and Cox proportional hazards analysis were conducted. In addition to the above analysis, single and multiple regression analysis were performed at baseline to reveal the relationship between serum magnesium and clinical parameters. Findings During the follow-up period, 31 out of 83 patients died. Kaplan-Meier analysis showed a significantly higher incidence of death in the Mg <2.5 mg/dL group (log-rank test 4.951, P = 0.026). Multivariate Cox proportional hazards analysis showed a 62% decreased risk of mortality in the Mg ≥2.5 mg/dL group compared to the Mg <2.5 mg/dL group after adjustment for several confounding factors. Simple correlation coefficient analysis showed positive correlations of serum magnesium levels with serum creatinine, phosphorus, high-density lipoprotein, ankle-brachial index and KT/V, and a negative correlation with age. Multiple linear regression analysis showed that the ankle-brachial index was the only parameter that had a positive and significant correlation with the serum magnesium level. Conclusion Our study demonstrated that higher serum magnesium levels were associated with improved survival in non-diabetic hemodialysis patients.

Microscopic polyangiitis associated with thymic tumor: a case report and review of the literature

Background

Thymic hyperplasia and thymic epithelial tumor (thymoma) have been associated with a variety of autoimmune diseases. Renal involvement has been reported in patients with thymoma. Minimal change disease and membranous nephropathy are frequently observed in glomerular lesions of thymoma patients, but ANCA-associated renal vasculitis is rare. We present a case of thymoma-associated microscopic polyangiitis with positivity for three ANCAs: MPO-ANCA, PR3-ANCA and azurocidin-ANCA.

Case presentation

An 89-year-old Japanese woman was admitted to our hospital following an episode of general fatigue, nausea, muscle weakness of the lower limbs, and ophthalmoplegia. On urinalysis, proteinuria, hematuria, and cellular casts were observed. Elevated levels of serum creatinine and C-reactive protein were also demonstrated, and MPO-, PR3- and azurocidin-ANCA were detected on serological examination. Renal biopsy showed pauci-immune crescentic glomerulonephritis. We therefore diagnosed rapidly progressive glomerulonephritis due to microscopic polyangiitis. Acetylcholine-receptor antibody was also detected. Chest computed tomography and MRI revealed a lobulated tumor in the anterior mediastinum. We thus also diagnosed myasthenia gravis with thymoma.

Conclusion

Considering the patient’s triple-ANCA positivity, thymic diseases may be associated with the pathogenesis of ANCA-associated vasculitis due to central T-cell tolerance. A further accumulation of cases is needed, because thymectomy does not always induce the remission of thymoma-associated autoimmune diseases.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1319-9) contains supplementary material, which is available to authorized users.

Can the Artificial Heart Make the Circulation Become Fractal?

In order to analyze the hemodynamic parameters in prosthetic circulation as an entity and not as decomposed parts, non linear mathematical analyzing techniques, including the fractal dimension analyzing theory, were utilized. Two pneumatically actuated ventricular assist devices were implanted, as biventricular bypasses (BVB), in chronic animal experiments, using four healthy adult goats. For the comparison between the natural and prosthetic circulation in the same animals, the BVB type complete prosthetic circulation model with ventricular fibrillation, was adopted. All hemodynamic parameters with natural and prosthetic circulation were recorded under awake conditions, and calculated with a personal computer system. Using the non-linear mathematical technique, the arterial blood pressure waveform was embedded into the return map as the beat-to-beat time series data and fractal dimension analysis were performed to analyze the reconstructed attractor. By the use of the Box counting method, fractal dimension analysis of the hemodynamics was performed. Return map of the hemodynamics during natural and artificial circulation showed fractal characteristics, and fractal dimension analysis of the arterial blood pressure revealed the fact that lower dimensional fractal dynamics were evident during prosthetic circulation. Fractal time series data is suggested to have robustness and error resistance, thus our results suggest that the circulatory regulatory system with an artificial heart may have these desired characteristics.

Urinary mulberry cells and mulberry bodies are useful tool to detect late-onset Fabry disease

Fabry disease is an X-linked lysosomal storage disorder caused by a lack of α-galactosidase A activity, which leads to the accumulation of globotriaosylceramide in various organs. A complete lack of α-galactosidase A activity in a hemizygous male is the classical phenotype, and some hemizygous males show primarily cardiac and/or renal symptoms that appear in adulthood; this is called the variant type or the late-onset type. The kidney and heart are the major target organs, with damage to these organs related to mortality. Thus, in Fabry patients, early detection and early treatment are critical to longevity. Here, we present a 55-year-old Japanese male patient who was diagnosed with late-onset Fabry nephropathy with cardiomyopathy but with no abnormal urinary findings except for urinary mulberry cells and mulberry bodies. In spite of the absence of abnormal urinary findings, the light microscopic and electron microscopic pathological findings showed extensive deposition of globotriaosylceramide to podocytes. In this paper, we propose that the presence of mulberry cells and mulberry bodies can be used for the earlier detection of Fabry nephropathy, especially the late-onset type.

Influence of acute kidney injury on the time to complete remission in adult minimal change nephrotic syndrome: a single-centre study

AIM

Acute kidney injury (AKI) is a common complication of minimal change nephrotic syndrome (MCNS), particularly in adults. We evaluated the prevalence of AKI at the onset of adult MCNS and analyzed the influence of AKI on the duration of achieving complete remission (CR).

METHODS

A retrospective, single-centre, dynamic cohort study was conducted with biopsy-proven, first-onset, adult MCNS patients treated with corticosteroids. Fifty-three consecutive patients diagnosed with MCNS from January 2000 to April 2014 were enrolled. Age, gender, daily urinary protein excretion, and serum creatinine levels were measured. To evaluate AKI during induction, we used the Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guidelines for AKI and judged AKI stage according to the fluctuations in serum creatinine levels during the first 4 weeks of starting corticosteroid therapy.

RESULTS

Twenty patients (37.7%) met the AKI criteria and all 53 patients achieved CR within 1 year. Kaplan-Meier analysis showed that the median time to CR was significantly longer in patients with AKI than in patients without AKI. Cox proportional hazard analysis showed that the hazard ratio (HR) associated with the presence of AKI for achieving CR within 4 weeks was 0.36 after adjustment for age, gender, serum albumin, daily urinary protein excretion, hypertension, administration of 25% albumin, and methylprednisolone pulse therapy. A graded association was also observed between AKI stage and HR for achieving CR.

CONCLUSIONS

The prevalence of AKI is high in adult patients with MCNS during induction therapy. AKI is an independent factor that delays the time to CR.

New onset of immunoglobulin G4-related disease in a patient with relapsing polychondritis

Relapsing polychondritis (RP) is a rare systemic autoimmune disorder characterized by the episodic and progressive deterioration of cartilage inflammation. Approximately 30% patients with RP have concurrent disease. However, there have been no previous reports of RP complicated by immunoglobulin G4-related disease (IgG4-RD). Here we report the case of a 67-year-old male who developed IgG4-RD approximately 20 years after RP diagnosis. The association between IgG4-RD and RP remains unclear.

Absence of mesangial C1q deposition is associated with resolution of proteinuria and hematuria after tonsillectomy plus steroid pulse therapy for immunoglobulin a nephropathy

INTRODUCTION AND AIMS

Deposition of C1q occurs in 0 to 45% of patients with IgAN. In order to identify whether mesangial C1q deposition in IgAN is a novel marker for the response to tonsillectomy plus steroid pulse therapy (TSP), we studied the association between mesangial C1q deposition in IgAN and the remission rate after TSP therapy for IgAN.

METHODS

We conducted a retrospective cohort study at a single Japanese center. We analyzed data on 110 patients diagnosed with IgA nephropathy who received TSP between January 2003 and December 2012. Positive C1q findings were defined as diffuse mesangial C1q deposition. The study outcome was the resolution of abnormal urinary findings and was defined as negative proteinuria and negative occult blood 1 year after steroid pulse therapy.

RESULTS

In all enrolled cases, 69 patients (62.7%) went into remission. Ten out of 24 (41.7%) C1q-positive patients experienced remission, and 59 out of 86 (68.6%) C1q-negative patients experienced remission. Multiple logistic regression model analysis showed that the absence of C1q deposition increased the odds ratio for remission (odds ratio 4.41; 95% confidence interval 1.33-15.75, p = 0.017).

CONCLUSIONS

These results suggest that the absence of diffuse C1q deposition in the mesangial area of the glomerulus in patients with IgA nephropathy is a positive predictive sign for a response to TSP and is associated with the resolution of urinary abnormalities 1 year after TSP.

Effects of intrathecal administration of nicardipine and nifedipine on chronic cerebral vasospasm in dogs

Chronic cerebral vasospasm after subarachnoid haemorrhage (SAH) responds poorly to systemic administration of dihydropyridine calcium antagonists. However, the spastic arteries can be dilated by the topical (intrathecal) administration of the drugs. We examined by angiography the spasmolytic effects of intrathecal (cisternal) administration of nicardipine (0.1 mg 1 ml ) or nifedipine (0.1 mg 1 ml ) on day 7 of SAH made by the two-haemorrhage model in dogs. Both drugs dilated the spastic basilar artery from 15 min till 4 hours after the drug administration. The increase in the diameter of the basilar artery between 1 and 3 hours was statistically significant in both groups. Intrathecal administration of nicardipine which is water soluble, may be useful in the treatment of chronic cerebral vasospasm in patients.

Phosphorylation of neuronal nitric oxide synthase at Ser847 in the nucleus intermediolateralis after spinal cord injury in mice

We previously demonstrated that Ca2+/calmodulin (CaM)-dependent protein kinase IIalpha (CaM-KIIalpha) can phosphorylate neuronal nitric oxide synthase (nNOS) at Ser847 and attenuate NOS activity in neuronal cells. In the present study we focused on chronological alteration in levels and cellular location of nNOS, phosphorylated (p)-Ser847-nNOS (NP847), CaM-KII and p-Thr286-CaM-KIIalpha following spinal cord injury (SCI) in mice. Western blot analysis showed nNOS to be significantly phosphorylated at Ser847 from 3 h after SCI, peaking at 24 h and gradually decreasing thereafter, and CaM-KII to be colocalized with nNOS after SCI. Immunohistochemical analysis revealed that SCI causes an increase in both NP847 and p-Thr286-CaM-KIIalpha in the nucleus intermediolateralis. These findings suggest that SCI induces p-Thr286-CaM-KIIalpha, which phosphorylates the nNOS at Ser847 in the nucleus intermediolateralis where NO is thought to play a role as a neurotransmitter in autonomic preganglionic neurons. Thus, the NP847 signaling pathway might be involved in the autonomic failure which occurs immediately after SCI.

A Case of Posterior Fossa Dural Arteriovenous Fistulas Successfully Treated with Transarterial Embolization

A 40-year-old man was transferred to our hospital due to sudden headache while swimming in the pool. CT revealed cerebellar haematoma within vermis associated with subarachnoid haemorrhage (SAH). Digital subtraction angiography (DSA) showed dural arteriovenous fistulas (DAVFs) with venous pouch on the surface of cerebellar vermis. Fistulas were on the meningeal surface near the sinus confluence. Draining veins formed venous pouch invaginating into cerebellar vermis.

Transarterial embolization (TAE) was performed under the concept that main feeder should be embolized last to occlude the DAVFs completely. Post-embolization 3D-CT showed the cast of N-butyl –cyanoacrylate (NBCA) in the fistulas as well as in the drainer. The good order of occlusion made the embolization complete.

Balance of risk of therapeutic hypothermia

The complications of therapeutic hypothermia sometimes undermine its clinical effects. In this study we investigated the efficacy and safety of therapeutic hypothermia based on analysis of 20 severe head injury cases from 6 institutions treated with therapeutic hypothermia in 1999. The twenty patients with severe head injury were enrolled prospectively based on the following indications; Glasgow Coma Scale of 7 or less on admission, age 60 or younger, and systric BP over 100 mmHg. A control group consisting of 21 patients with severe head injury met the same criteria but were treated without therapeutic hypothermia in other institutions. Clinical benefit were evaluated by a comparison of clinical result in the two groups defined according to the Glasgow Outcome Scale six months after injury. The hypothermia group was divided into two groups based on a target temperature [mild hypothermia group: 32-34 degrees C (n = 10); very mild hypothermia group: 35-36 degrees C (n = 10)]. The complication rate, clinical results and the duration of therapeutic hypothermia were analyzed between two groups. In the hypothermia group, 12 patients obtained a favorable outcome (Good Recovery or Moderate Disabled in GOS) and the mortality rate was 35%. In the control group, however only 5 patients had a favorable outcome and the mortality rate was 57%. Comparison between mild hypothermia and very mild hypothermia groups revealed no difference in clinical outcome. In the hypothermia group, severe pneumonia was seen in three patients, all in the mild hypothermia group with a hypothermic duration of over 120 hours. Mild hypothermia should be ended within 120 hours to avoid severe complication. When long-lasting therapeutic hypothermia of more than 120 hours is planned, very mild hypothermia is the treatment of choice.

Effect of early induction of hypothermia on severe head injury

Although therapeutic hypothermia for patients with head injury has improved the outcome, the results in the most severe cases (GCS 3-6) have not been satisfactory so far. We induced hypothermia in head injury patients within 3 hours after the trauma, and compared the outcome of the treatment without hypothermia. Fourteen patients with GCS less than 6 were entered into this study (age range 13 to 58, mean 27.0 years). Seven of them were treated by hypothermia and 6 by the conventional method. The patients undergoing hypothermia were cooled to 34 degrees C within 3 hours after injury, kept at 32-34 degrees C for 48 hours, and then rewarmed. The outcome was evaluated at 6 months post-trauma, and the results were compared in the two groups. Therapeutic hypothermia dramatically suppressed brain swelling on CT in 3 of 7 patients. Four patients including these 3 showed a favorable outcome (good or moderate disability) and 3 died in the hypothermia group. In the conventional treatment group, only 1 patient was moderately disabled and 6 exhibited an unfavorable outcome (severely disabled, vegetative, or death). Early induction of hypothermia can improve the outcome in patients with severe head injury by reducing the severe brain swelling.

Adrenomedullin reduces ischemic brain injury after transient middle cerebral artery occlusion in rats

BACKGROUND

The effect of adrenomedullin, a vasodilatory peptide on transient middle cerebral artery (MCA) occlusion was investigated in rats.

METHODS

Transient MCA occlusion for 2 hours was made by using the intra-arterial suture method, followed by reperfusion.

FINDINGS

An intravenous infusion of adrenomedullin (1 microg/kg/min) from one hour before ischemia to one hour after ischemia significantly reduced the infarct size and improved neurological deficits (p<0.05), without affecting systemic blood pressure or other physiological parameters. The infarct size was reduced with adrenomedullin by 25.4+/-12.7%, 31.3+/-5.8%, 31.6+/-6.1% respectively at the coronal level 6, 8 and 10 mm posterior from the frontal pole. Adrenomedullin also significantly inhibited the increase in myeloperoxidase (MPO) activity in the MCA area of the ischemic hemisphere after 22-hour reperfusion (control: 0.205+/-0.054 unit/g wet tissue, adrenomedullin group: 0.047+/-0.009 unit/g wet tissue, p<0.0001).

INTERPRETATION

These data suggest that adrenomedullin reduces acute ischemic brain injury and one of is neuroprotective mechanisms may be derived from inhibition of the infiltration of neutrophils into the ischemic tissue.

Role of nitric oxide in the control of cerebral microcirculation under physiological and pathological conditions

Effect of nitric oxide (NO) on vasomotor tone of cerebral parenchymal arterioles was studied in rats. Then, the role of NO was clinically investigated in the pathogenesis of progressive cerebral vascular occlusive disease, moyamoya disease. In rat, the cerebral arterioles, about 30-60 microm in diameter, were dilated by L-arginine, a precursor of NO, at concentrations as low as 0.1 micromol with maximal dilation of 14% at 100 micromol. The arterioles were constricted by N(G)-monomethyl-L-arginine (L-NMMA), a NO synthesis inhibitor. Superoxide dismutase, which seems to protect NO from inactivation, increased sensitivity of L-arginine. Compared with control specimens of cerebral spinal fluid (CSF) obtained from 16 patients, concentrations NO metabolites in the CSF of 23 patients with moyamoya disease were significantly higher. NO metabolites concentrations obtained during initial surgery decreased during a second, contralateral procedure. NO plays an important role in the regulation of basal tone of cerebral parenchymal arterioles and contributes to the increase in collateral circulation in cerebral occlusive disease like moyamoya disease. Vascular bypass surgery can reduce NO metabolites together with abnormal collateral circulation.

Recurrence of a neurenteric cyst with malignant transformation in the foramen magnum after total resection. Case report

A 53-year-old man presented with recurrence of a neurenteric cyst with malignant transformation in the foramen magnum 3.5 years after total resection of the original tumor had been reported. For 2 years following the initial surgery, the patient had been in good condition, but then underwent ventriculoperitoneal shunt placement for intracranial hypertension. At the time there was no evidence of recurrence of the tumor on magnetic resonance (MR) images. One and one-half years later, he presented with headache and anorexia. A massive recurrent tumor was identified on MR images. The tumor was severely adhesive to the brainstem, cranial nerves, and vessels, allowing only partial resection. Histological examination of tumor specimens obtained during the first and second craniotomies indicated a malignant change from a typical neurenteric cyst with a one-layer epithelium in the first specimen to an adenocarcinoma with papillary proliferation in the second. The results of various immunohistochemical studies of the first specimen were typical of those of a neurenteric cyst. The second specimen displayed stronger staining of carbohydrate 19-9 and carcinoembryonic antigens than the initial specimen. The percentage of Ki-67 antigen (MIB-1)-positive cells increased from 0% in the first specimen to 6.7% in the second. To the authors' knowledge this is the first case in which malignant transformation has been demonstrated after total resection of a neurenteric cyst in the foramen magnum.

Elevation of nitric oxide metabolites in the cerebrospinal fluid of patients with moyamoya disease

BACKGROUND

To investigate whether nitric oxide (NO) contributes to formation of abnormal collateral circulation in patients with moyamoya disease.

METHODS

Cerebrospinal fluid (CSF) samples were obtained from the subarachnoid space of the Sylvian fissure during combined bypass surgery for moyamoya disease and kept frozen until NO metabolites, nitrate and nitrite, were measured using a Griess method.

RESULTS

Compared with control CSF obtained from 18 patients with hemifacial spasm, unruptured aneurysm, etc., concentrations of NO metabolites in 26 CSF samples of 18 patients with moyamoya disease were significantly higher (mean +/- SE; 17.6 +/- 1.2 vs. 10.5 +/- 1.0 microM, p < 0.01). In eight patients, the CSF samples from both the first and second operation could be obtained. NO metabolite concentrations (20.5 +/- 2.3 microM) in CSF obtained from the first surgery decreased to 15.7 +/- 1.8 microM (p < 0.01) in CSF obtained from the second, contralateral procedure. The cases of moyamoya disease with greater development of moyamoya vessels at angiographic stage 3 and 4 tended to show higher concentrations of NO metabolites than cases at earlier or later stages with a few moyamoya vessels.

INTERPRETATION

Nitric oxide concentrations in CSF are chronically elevated in moyamoya disease, probably reflecting development of abnormal collateral circulation. i.e. moyamoya vessels. Vascular bypass surgery can reduce abnormal collateral circulation with reduced production of nitric oxide.

Vasodilatory effect of basic fibroblast growth factor in isolated rat cerebral arterioles: mechanisms involving nitric oxide and membrane hyperpolarization

Basic fibroblast growth factor (bFGF), a potent mitogen, acutely dilates cerebral blood vessels and may be effective in reducing cerebral infarction. However, the vasodilatory mechanism, which may involve nitric oxide (NO), is not completely understood. This study investigated whether membrane hyperpolarization is also involved in this mechanism. Membrane potential (MP) of smooth muscle cells and vessel diameter of isolated intracerebral arterioles were simultaneously measured following extraluminal application of bFGF in rats. The involvement of NO and adenosine triphosphate-sensitive potassium (KATP) channels in bFGF-induced vasodilation and membrane hyperpolarization was evaluated using specific inhibitors, NG-monomethyl-L-arginine (L-NMMA, 10(-4) M) and glibenclamide (GB, 10(-5) M), respectively. The resting MP was recorded at a mean value of -31.9 +/- 4.5 mV. bFGF (1 to 1000 ng/ml) produced significant vasodilation and hyperpolarization. Treatment with L-NMMA caused vasoconstriction and significantly attenuated bFGF-induced vasodilation without affecting membrane hyperpolarization. In the presence of GB, the membrane potential was significantly depolarized but the vessel diameter was only marginally reduced, so bFGF-induced membrane hyperpolarization was inhibited while arteriolar dilation was attenuated. These results suggest that bFGF-induced vasodilation is mediated by a mechanism involving both NO and membrane hyperpolarization, and that membrane hyperpolarization is caused by the activation of KATP channels.

Time course of expression of three nitric oxide synthase isoforms after transient middle cerebral artery occlusion in rats

The involvement of nitric oxide synthase (NOS) in ischemia was evaluated by detecting the expression of neuronal NOS (nNOS), endothelial NOS (eNOS), and inducible NOS (iNOS) by the immunohistochemical method in the rat model of middle cerebral artery (MCA) occlusion. Transient MCA occlusion (2 hours) was induced in 32 male Wistar rats by extracranial insertion of a 3-0 nylon thread through the internal carotid artery into the MCA. Animals were killed at 0, 6, 24, 72, and 168 hours after MCA occlusion (n = 6, 6, 8, 6, and 6, respectively). The brains were fixed with periodate-lysine-paraformaldehyde, frozen, and sectioned. Sections were stained with polyclonal antibody against nNOS, eNOS, and iNOS. Each section was evaluated by microscopic observation (x100). The number of nNOS-positive neurons was 41.6 +/- 5.8 (mean +/- SD) in the control hemisphere. nNOS was upregulated in the ischemic hemisphere (88.3 +/- 18.9), especially in the border zone at 6 hours after MCA occlusion. However, the number decreased to 36.4 +/- 3.6 and 26.3 +/- 7.3 in the ischemic hemisphere after 72 and 168 hours, respectively. eNOS immunoreactivity was present in the endothelium of major vessels at each time point. eNOS was not detected in the microvessels before ischemia, but faint staining was found in the endothelium at 6 hours after MCA occlusion. Immunostaining became more intense thereafter. Faint iNOS immunoreactivity was seen in the microvessels at 6 hours after MCA occlusion. Macrophages in the ischemic core and astrocytes in the border zone showed immunoreactivity to iNOS at 72 and 168 hours after MCA occlusion. Three types of NOS must be related to different stages of ischemic brain damage. nNOS may be neurotoxic in ischemia in the early phase, like iNOS in the late phase. On the other hand, eNOS seemed to be neuroprotective in all stages. These observations suggest the necessity for tailored therapeutic intervention against NOS isoforms at each stage in patients with ischemic stroke.

En bloc laminoplasty performed with threadwire saw

OBJECTIVE

To introduce a method for a simple, nonexpansive laminoplasty that can be performed with a threadwire saw (T-saw) after en bloc laminotomy has been performed. The method can be applied along the entire spinal region, including the thoracic and lumbar spine.

METHODS

An en bloc laminotomy of trapezoid shape at the cross section is performed bilaterally at the junctional area of the lamina and facet joint with a thin, flexible T-saw, while preserving the supraspinous, interspinous, and interlaminar ligaments. After the intradural procedure has been performed, the laminar flap is replaced in its original site and fixed with 1-0 nylon sutures, resulting in the complete reconstruction of the posterior supporting elements of the spinal column.

RESULTS

En bloc laminoplasty was performed on 16 patients via a T-saw; most of the patients had intradural spinal tumors. The patients did not need their spinal canals to be enlarged after the intradural procedure had been performed. The follow-up period ranged from 2 to 40 months (mean +/- standard error, 22.6 +/- 3.4 mo). The laminoplasty was performed from the upper cervical to the sacral regions, although the most frequently operated level was the lower thoracic level. Two-level laminoplasty was performed in 12 patients, and three-level laminoplasty was performed in four. The laminoplasty was done safely and without any complications, except in one patient, who experienced thoracic root injury from a T-saw that was accidentally inserted anterior to the roots. No spinal column deformity or sinking of the replaced laminar flap was noted during the follow-up period; patients were assessed at follow-up via radiographs or computed tomographic scans. Computed tomographic scans obtained later indicated that bony fusion occurred at the cutting edges 1.0 to 4.0 months after surgery (mean, 1.90 +/- 0.34 mo).

CONCLUSION

Simple en bloc laminoplasty performed with a T-saw is a useful, safe procedure that can be used to reconstruct the posterior spinal elements throughout the whole spinal region after the intradural procedure has been performed.

Clinical safety and performance of Sugita titanium aneurysm clips

BACKGROUND

In spite of advantages for neuro-imaging, titanium aneurysm clips are not yet chosen for routine use for clipping of intracranial aneurysms, probably because their reliability has not been demonstrated in large numbers of cases. We assess reliability and safety of Sugita titanium aneurysm clips for routine clinical use in a large number of operated cases.

METHOD

Intra-operative performance and safety of Sugita titanium aneurysm clips were evaluated in 347 patients in our institutions. Aneurysms in 261 patients had ruptured: 86 patients had unruptured aneurysms.

RESULTS

A total of 441 clips of 52 different types were used. No early or delayed complications occurred in relation to the titianium clips, such as deformity or slippage of a clip. Patient outcome according to the Glasgow Outcome Scale was similar to that when conventional cobalt-based aneurysm clips were used.

INTERPRETATION

Reliability and safety of Sugita aneurysm clips were demonstrated in a large number of patients. The clips are suitable for routine use in aneurysm surgery.

Percutaneous microcompression of the trigeminal ganglion for elderly patients with trigeminal neuralgia and patients with atypical trigeminal neuralgia

Percutaneous microcompression of the trigeminal ganglion (PMTG) was performed in nine elderly patients (> 70 years) with trigeminal neuralgia and six patients with atypical neuralgia under short-acting anesthesia using propofol. Two patients had postherpetic neuralgia and two had postoperative neuralgia following removal of a posterior fossa neurinoma. Four patients had recurrent neuralgia following microvascular decompression (MVD). PMTG provided complete relief in 10 patients and the other five patients reported at least 50% improvement. No major complications occurred. PMTG is effective for typical trigeminal neuralgia in elderly patients, patients with atypical trigeminal neuralgia, and patients with recurrence after MVD.

Protein kinase inhibition by fasudil hydrochloride promotes neurological recovery after spinal cord injury in rats

OBJECT

In Japan fasudil hydrochloride (HA1077), a protein kinase inhibitor, is widely administered to prevent vasospasm in patients after subarachnoid hemorrhage. The effects of fasudil on experimental spinal cord injury (SCI) were investigated and compared with those obtained using methylprednisolone.

METHODS

Spinal cord contusion was induced in rats by applying an aneurysm clip extradurally to the spinal cord at T-3 for 1 minute. After injury three groups of rats were treated with intravenously administered saline (control), intraperitoneally administered fasudil (10 mg/kg), or intravenously administered methylprednisolone (four 30 mg/kg injections). Neurological recovery was evaluated periodically over 1 month by using a modified combined behavioral scale and histopathological examination. Leukocyte infiltration near the injury site was evaluated by measuring myeloperoxidase (MPO) activity at 24 hours. Spinal cord blood flow was measured at intervals up to 3 hours after injury by using laser Doppler flowmetry. In rats in the fasudil-treated group significant improvement in modified combined behavioral score was demonstrated at each time point, whereas in the methylprednisolone-treated rats no beneficial effects were shown. In the fasudil-treated group, reduction of traumatic spinal cord damage was evident histologically in the caudal portion of the injured areas, and tissue MPO activity in tissue samples was reduced. Spinal cord blood flow was not significantly different between fasudil-treated and control group rats.

CONCLUSIONS

Fasudil hydrochloride showed promise of effectiveness in promoting neurological recovery after traumatic SCI. Possible mechanisms of this effect include protein kinase inhibition and decreased infiltration by neutrophils.

[Intramedullary spinal cord metastasis associated with hemorrhage: a case report]

A rare case of intramedullary spinal cord metastasis associated with hemorrhage was reported. A 74-year-old man had a subacute onset of paraparesis. He became almost paraplegic within a few days. MRI revealed an intramedullary spinal lesion in the epiconus at the Th 11 and Th 12 level, but spinal angiography did not show any abnormality. Since repeated MRI showed enlargement of the lesion, surgery was performed under the diagnosis of an intramedullary spinal cord tumor. Under general anesthesia, a midline myelotomy of about 3 cm was performed and a grayish, elastic and circumscribed tumor as well as a liquefied hematoma in the caudal part was observed. Both the tumor and the hematoma were removed almost totally. The patient's paraparesis improved slightly after surgery. The histological diagnosis was adenocarcinoma. The primary source was unknown, but multiple small metastatic tumors were found in the lung, liver and brain, etc. Hemorrhage from intramedullary spinal cord metastasis is extremely rare with only 6 reported cases in the recent literature. Rapid deterioration of symptoms caused by the hematoma may make the diagnosis more difficult. Indication of surgical treatment should be carefully determined because prognosis of intramedullary spinal cord metastasis is generally very poor.

Treatment of traumatic atlanto-occipital dislocation in chronic phase

We report the case of 27-year-old woman who presented with mild neurological deficits with significant anterior dislocation of the atlanto-occipital junction in a chronic phase after initial conservative treatment in another hospital. The importance of early diagnosis and treatment for atlanto-occipital dislocation is emphasized. The dislocation could not be reduced sufficiently either by halo ring cervical traction or surgical procedure 5 months after the accident. Therefore, transoral odontoidectomy for decompression of the medulla, together with the posterior occipitocervical fusion with a titanium loop brace was performed. The patient's symptoms disappeared completely within a few months after the operation. Magnetic resonance imaging findings suggesting soft tissue damage is the key to an early diagnosis and subsequent stabilization of traumatic atlanto-occipital dislocation in the early phase. Transoral decompressive odontoidectomy combined with posterior fusion may be considered for the treatment of irreducible atlanto-occipital dislocation in a chronic phase.

Osteoplastic anterolateral vertebrotomy without fusion for multilevel cervical ossification of the posterior longitudinal ligament

OBJECTIVE

To introduce a new method for osteoplastic anterolateral vertebrotomy without fusion to resect multilevel cervical ossification of the posterior longitudinal ligament.

METHODS

A multilevel vertebral column graft containing portions of the intervertebral discs is cut with a microsurgical saw from the anterolateral part of the vertebra via a thin lateral gutter placed in advance. A sufficiently wide oblique operative field is provided for resection of the ossified ligament with this method, and only a narrow bony defect remains after simple replacement of the vertebral graft. Postoperatively, patients are allowed to walk, usually within 2 to 3 days, wearing simple cervical collars.

RESULTS

Twelve patients underwent resection of the ossified ligaments in two to five vertebral bodies. Clinical results were satisfactory except in one patient, who died as a result of a pulmonary embolism that occurred 10 days after surgery. In all of the other patients, the vertebral column grafts were fused within a few months, and there were no graft-related problems. Postoperative lateral radiographs revealed that cervical alignment was preserved, with intervertebral mobility at the operated segment in flexion-extension views.

CONCLUSION

The osteoplastic anterolateral vertebrotomy method provided a sufficiently wide operative field for satisfactory resection of multilevel cervical ossification of the posterior longitudinal ligament, simplifying graft replacement and postoperative patient care. The cervical alignment was preserved.

Titanium aneurysm clips: mechanical characteristics and clinical trial

Titanium clip is well documented to reduce the artifact observed in computed tomography (CT) or magnetic resonance (MR) imaging and improve the quality of these images. There are, however, some demerits based on metallic characteristics including large spring portions, lack of long and fenestration clips, and difficulties to produce. We examined the mechanical characteristics of Sugita titanium aneurysm clips (product of 6 aluminium-4 vanadium-titanium) and investigate the safety in clinical use and the imaging quality compared with those of cobalt (Co) alloy clips. On mechanical test, Sugita titanium clips showed no significant difference in closing force compared with the conventional Co alloy clips. The closing force reduced about 10% after 100 times repeated opening in titanium clips in contrast with no remarkable changes in Co alloy clips. Sixty-four patients with ruptured or unruptured cerebral aneurysms (total number of 71 aneurysms) were treated with Sugita titanium clips through the microsurgical technique. None of the unfavorable outcome occurred in related to the titanium clips. Neither clip dislocation nor deformation was experienced in this series during the follow-up period. The clip artifacts seen in CT and MR image were markedly reduced, however, MR angiography had less quality to resolve anatomical structures due to an existence of vessel gap. These results indicate that in spite of some disadvantages, Sugita titanium clips allow safe and beneficial use routinely in aneurysm surgery insofar as the complete clipping is obtained.

Intra-arterial infusion of fasudil hydrochloride for treating vasospasm following subarachnoid haemorrhage

In this pilot study we treated cerebral vasospasm in patients with subarachnoid haemorrhage to assess intra-arterial fasudil hydrochloride. We analysed effects of intra-arterial infusion on angiographically evident cerebral vasospasm in 10 patients including 3 with symptoms of vasospasm. Over 10 to 30 min 15 to 60 mg was administered via the proximal internal carotid artery or vertebral artery following standard angiography, without superselective techniques. A total of 24 arterial territories (21 internal carotid, 3 vertebral) were treated. Angiographic improvement of vasospasm was demonstrated in 16 arterial territories (local dilation in 2, diffuse dilation in 14) in 9 patients. In 2 symptomatic patients, intra-arterial fasudil hydrochloride was associated with resolution of symptoms without sequelae. In the third symptomatic patient the benefit of fasudil hydrochloride was only temporary, and a large cerebral infarction occurred. All asymptomatic patients showed no progression of angiographic to symptomatic vasospasm after treatment with intra-arterial fasudil hydrochloride. No adverse effect was encountered.

Anterior cervical decompression and fusion for cervical spondylosis using vertebral grafts obtained from the fusion site. Technical advantages and follow-up results

A retrospective analysis was done in 60 consecutive patients who underwent anterior cervical fusion using vertebral grafts obtained from the fusion site at the Nagoya University and its affiliated hospitals by a single surgeon (MT). Follow-up results and technical advantages are reported. The average follow-up period was 33 months (range 6 to 55 months). Sufficient decompression of the anterior cervical pathology was performed successfully via a wider operative field. The symptoms and neurological score improved significantly without any new deficits in all patients except in one with a three-level fusion who needed re-operation for further decompression. No major graft complications such as graft extrusion or pseudoarthrosis occurred. Graft fracture was noted in five cases. However, good bony fusion was observed in all these cases without any further treatment. Normal cervical lordosis was preserved in most cases except in four, who lost lordotic alignment but did not show kyphosis. Major advantages of this method are a wider operative field, excellent graft fusion rate, and no need for an additional incision to obtain autogenous bone graft. These benefits seem have to contributed to satisfactory surgical results in this series.

Interleukin-6 and development of vasospasm after subarachnoid haemorrhage

The authors characterized the role of interleukins in the cerebrospinal fluid (CSF) in the development of vasospasm after subarachnoid haemorrhage (SAH), particularly interleukin-6 (IL-6). Concentrations of interleukin-1 beta (IL-1 beta), IL-6, and interleukin-8 (IL-8) were measured serially in CSF of 24 patients and in serum of 9 patients with SAH and correlated clinically. Additionally, the effects of the same cytokines on the cerebral arteries of dogs were analyzed on angiograms after intracisternal injection. Changes in levels of eicosanoids, angiogenic factors, and soluble cell adhesion molecules were investigated in the CSF of injected dogs. CSF concentrations of IL-6 and IL-8 were elevated significantly above control levels from the acute stage of SAH until the chronic stage. Patients with symptomatic vasospasm had significantly higher levels of IL-6 as well as IL-8 in CSF on days 5 and 7. Intracisternal injection of IL-6 induced long-lasting vasoconstriction in five out of eight dogs, while IL-8 did not. The diameter of canine basilar artery after IL-6 was reduced 29 +/- 5% from pretreatment diameter at 8 hours. Prostaglandins E2 and I2 were elevated in CSF for the first 4.5 hour of this IL-6-induced vasospasm. Neither angiogenic factors such as platelet-derived growth factor-AB and vascular endothelial growth factor nor soluble cell adhesion molecules were significantly elevated in CSF. IL-6, which increases to very high concentrations in CSF after SAH, may be important in inducing vasospasm, as IL-6 produced long-lasting vasoconstriction in the canine cerebral artery, which may be partly related to activation of the prostaglandin cascade.

Inducible cyclooxygenase expression in canine basilar artery after experimental subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Inducible cyclooxygenase (COX-2) has been found to play a pathological role in cerebral insult. We investigated the expression of COX-2 in the basilar artery after experimental subarachnoid hemorrhage (SAH).

METHODS

In a canine "two-hemorrhage" model of SAH, the basilar arteries were obtained on day 2 after a cisternal injection of autologous blood or on days 4, 6, 7, or 9 after the second injection. Basilar arteries also were obtained 12 hours after intracisternal injection a cytokine: interleukin (IL)-1 beta (0.03 microgram), IL-6 (3 micrograms), or IL-8 (10 micrograms). Western blotting with a polyclonal anti-COX-2 antibody was performed in these arteries.

RESULTS

COX-2 protein was not demonstrated in the basilar artery in control animals without SAH. However, it was expressed in the basilar artery on days 2, 4, 6, and 7 after blood injection but not on day 9. Intracisternal injection of IL-1 beta, IL-6, or IL-8 also induced COX-2 in the basilar artery.

CONCLUSIONS

COX-2 expression was detected in basilar arterial tissue in both acute and chronic stages after SAH. Elevation of inflammatory cytokines after SAH may be involved in the induction of COX-2, which may produce sufficient quantities of eicosanoids to affect hemodynamics after SAH.

Possible role of nitric oxide in autoregulatory response in rat intracerebral arterioles

OBJECTIVE

Cerebral autoregulation is an important regulatory mechanism that maintains a constant cerebral blood flow over a wide range of perfusion pressures. The goal of this study was to determine whether nitric oxide contributes to the autoregulatory response of cerebral arterioles to altered transmural pressure (TMP).

METHODS

Seventy-nine intraparenchymal arterioles (53.6 +/- 3.5 microm mean diameter) isolated from rats were cannulated with micropipettes and pressurized at a TMP of 60 mm Hg (control pressure). Vessel diameters were monitored continuously using a video dimensional analyzer. The autoregulatory diameter responses to varying intraluminal pressures were observed in the presence and absence of a nitric oxide synthase inhibitor, NG-monomethyl-L-arginine (L-NMMA). The effect of L-NMMA-induced constriction on autoregulatory response also was compared with responses after prostaglandin F2alpha and alkalosis-induced constrictions.

RESULTS

Autoregulatory responses were observed over a range from 10 to 90 mm Hg of TMP. Treatment with 10(-4) mol/L L-NMMA constricted arterioles and inhibited the autoregulatory vasodilation to TMP reductions from 60 mm Hg to 10 or 30 mm Hg. In L-NMMA-treated arterioles, elevation in TMP from 60 to 90 mm Hg caused an autoregulatory vasoconstriction. Treatment with alkaline pH 7.65 constricted arterioles to a similar degree as that induced by L-NMMA at 60 mm Hg, and under these conditions, the autoregulatory response remained intact. Arterioles severely constricted with prostaglandin F2alpha showed no significant autoregulatory response.

CONCLUSION

These results suggest that 1) vascular nitric oxide release increases in response to a decrease in TMP from 60 mm Hg, thereby contributing to the autoregulatory vasodilation intrinsic to the vessel during hypotension, 2) arteriolar nitric oxide appears not to be involved in the autoregulatory vasoconstriction induced by elevating TMP from 60 to 90 mm Hg, and 3) a marked increase in vascular tone may affect autoregulatory response.

Benign osteoblastoma of the odontoid process of the axis: a case report

BACKGROUND

The majority of benign spinal osteoblastomas arise from the posterior elements of the spine; there have been no published reports of the tumor in the odontoid process of the axis. Accurate preoperative localization of the tumor is important for planning minimally invasive surgery on such benign tumors. However, the magnetic resonance imaging (MRI) findings may be misleading, because peritumoral changes may be confusing.

CASE DESCRIPTION

We report the case of a 20-year-old man, who presented with a 4-year history of protracted left posterior neck pain. Preoperative computed tomography (CT) revealed a discrete mixed-density mass within the odontoid process. MRI showed diffusely abnormal signal intensity and enhancement both in the odontoid process and the body of the axis, including regions from which biopsy specimens were normal or had minimal inflammatory changes. Precise preoperative localization of the tumor margins using CT and biopsy allowed for successful resection of the tumor via a transoral approach with preservation of a part of the axis and the odontoid process. Consequently, stabilization of the spine was unnecessary, and the patient remained symptom-free for 3.5 years.

CONCLUSION

We reported a rare case of benign osteoblastoma of the odontoid process of the axis. The tumor was successfully resected via a transoral approach, preserving a part of the axis and the odontoid process. We have emphasized an advantage of CT over MRI for accurate localization of the tumor.

Vasodilator effects on canine basilar artery induced by intracisternal interleukin-1 beta

The effect of interleukin-1 beta (IL-1 beta) on a cerebral artery was investigated in anesthetized dogs. Intracisternal administration of IL-1 beta (0.03 and 0.3 micrograms) dilated the canine basilar artery in a dose-dependent manner, without affecting systemic blood pressure or heart rate. The increase in diameter induced by 0.3 micrograms of IL-1 beta was 28.4% +/- 13.4% of control at 2 hours and was inhibited by 30 micrograms of the IL-1 beta receptor antagonist, zinc protoporphyrin (4.5% +/- 13.5%, P < 0.05). Interleukin-1 beta did not affect the concentration of nitric oxide metabolites in CSF. However, there was an increase in the concentration of eicosanoids in CSF, and the elevation of 6-keto-PGF1 alpha paralleled the vasodilation. Pretreatment with 30 micrograms of the selective inducible cyclooxygenase (COX-2) inhibitor NS-398 also inhibited the IL-1 beta-induced vasodilation significantly (5.9% +/- 9.4% at 2 hours, P < 0.01). Western blot analysis revealed the expression of a 68-kD COX-2-like protein in basilar artery extracts. These findings suggest that the IL-1 beta-induced vasodilator effect is linked to the prostaglandin cascade, predominantly to prostaglandin I2, by induction of COX-2, but not to the stimulation of nitric oxide metabolism.

Results of 55 AVM Cases Treated by Embolization and/or Surgery

SUMMARY

In order to build a data base for future comparison, we summarized the treatment results of cerebral arteriovenous malformation (AVM) patients in our hospital. Fifty five AVM patients who had been treated at Nagoya University Hospital from 1988 to 1995 were enrolled in the study. The patient characteristics were nearly the same as other reported series. Trend of treatment modality was changing in this period and embolization was increasing in its role. Karnofsky score was used to follow the patients' clinical status. It was useful to assess pretreatment clinical status and post treatment status. The results showed the improvement of the embolization procedure.

Nitric oxide metabolites in the cisternal cerebral spinal fluid of patients with subarachnoid hemorrhage

OBJECTIVE

To investigate nitric oxide (NO) metabolism after subarachnoid hemorrhage (SAH).

METHODS

We measured the concentrations of the NO metabolites, nitrite and nitrate, in cerebrospinal fluid (CSF) obtained from the cisternal drainage of patients with SAH. Studies were performed for 31 patients who had undergone surgical obliteration of bleeding aneurysms within 3 days of their hemorrhage. The concentrations of nitrite and nitrate in the CSF were measured for 14 days using a nitrate/nitrite kit and samples that were obtained on a daily basis from the cisternal drainage.

RESULTS

Compared with the control values in the CSF (2.6 +/- 0.4 mumol/L, n = 14) obtained from patients with hemifacial spasm, trigeminal neuralgia, or nonruptured aneurysms, the concentrations of nitrite and nitrate in the CSF were significantly elevated in the acute stage of SAH and remained elevated. The concentration of NO metabolites may correlate with the amount of bleeding, inasmuch as the values in patients in Fisher Group 3 (n = 25) were higher than those in patients in Fisher Group 2 (n = 6). The concentration of nitrate was higher than that of nitrite, suggesting that NO in the subarachnoid space is mainly absorbed by hemoglobin and degraded to nitrate. No differences were demonstrated in patients treated with high doses of methylprednisolone (n = 17) compared with those treated with usual-dose steroids (n = 14). Steroids are known to prevent the formation of inducible NO synthase mediated by inflammatory cytokines.

CONCLUSION

NO metabolism in the brain is stimulated after SAH. Nitrate is the dominant NO metabolite in CSF after SAH. The involvement of inducible NO synthase in the pathophysiology of NO metabolism after SAH was not clearly suggested based on the present data.

Effects of adrenomedullin on rat cerebral arterioles

The effects of adrenomedullin on isolated rat intracerebral arterioles were investigated and compared with those of calcitonin gene-related peptide (CGRP) and amylin. Adrenomedullin produced dose-dependent vasodilation (maximum dilation 27.1 +/- 2.1% at 3 x 10(-7) M, median effective dose (EC50)) 1.6 x 10(-9) M). CGRP produced similar vasodilation (19.8 +/- 4.1%) at 10(-7) M with a lower EC50 of 2.8 x 10(-11) M. Amylin did not cause vasodilation at concentrations up to 10(-6) M. Adrenomedullin-induced vasodilation was significantly suppressed by CGRP-(8-37). These data suggest that adrenomedullin is a potent vasodilator for arterioles in the cerebral microcirculation that acts through CGRP receptors.