Direction-selective Resistance to Cerebrospinal Fluid Flow as the Cause of Syringomyelia

The pathophysiology of syringomyelia remains poorly understood. Two prevailing challenges stand out: the need for a comprehensive understanding of its diverse types and the yet-to-be-explained mechanism of cerebrospinal fluid (CSF) retention in the syrinx despite its higher pressure than that in the adjacent subarachnoid space. Expanding on our previous proposal that direction-selective resistance to subarachnoid CSF flow drives syringomyelia genesis, this study uses a computer model to explore this mechanism further. We developed a computer simulation model to study spinal CSF dynamics, employing a lumped parameter approach with multiple compartments. This model replicated the to-and-fro movement of CSF in the spinal subarachnoid space and within an intraspinal channel. Subsequently, a direction-selective resistance-opposing only the caudal subarachnoid CSF flow-was introduced at a specific location within the subarachnoid space. Following the introduction of the direction-selective resistance, a consistent pressure increase was observed in the intraspinal channel downstream of the resistance. Importantly, this increase in pressure accumulated with every cycle of to-and-fro CSF flow. The accumulation results from the pressure drop across the resistance, and its effect on the spinal cord matrix creates a pumping action in the intraspinal channel. Our findings elucidate the mechanisms underlying our hypothesis that a direction-selective resistance to subarachnoid CSF flow causes syringomyelia. This comprehensively explains the various types of syringomyelia and resolves the puzzle of CSF retention in the syrinx despite a pressure gradient.

Modified Unilateral Approach for Ventrally Located Spinal Tumors

Surgery on spinal tumors becomes challenging when the tumor is ventral to the spinal cord. Conventionally, we approach it posteriorly through bilateral laminectomy and rotate the cord after sectioning the dentate ligament and nerve roots. However, manipulating the cord can be hazardous, and a long bilateral laminectomy can be invasive. Meanwhile, a narrow operative field and a limited lateral viewing angle in a unilateral approach constrained the surgeon. To overcome these problems, we previously reported a technique of modified unilateral approach where we incised the skin and the fascia horizontally and placed a pair of retractors longitudinally.The current article reports our experience applying this approach in 15 patients with ventrally located spinal tumors. The approach was performed on 10 schwannomas, 2 meningiomas, and 3 others. We evaluated paraspinal muscle atrophy on postoperative magnetic resonance imaging.The modified unilateral approach provided an excellent surgical field for removing ventrally located tumors. Gross total removal was achieved in 11 patients (92% of benign tumors). No neurological complications occurred except for one case of transient weakness. We encountered no wound-related late complications such as pain or deformity. The reduction of the cross-sectional area of the paraspinal muscles on the approach side (compared to the nonapproach side) was 0.93 (95% confidence interval: 0.72-1.06), indicating 7% atrophy (statistically nonsignificant, p = 0.48).We believe this simple technique can be useful for removing spinal tumors located ventral to the spinal cord.

Hypothesis on the pathophysiology of syringomyelia based on analysis of phase-contrast magnetic resonance imaging of Chiari-I malformation patients

Background: Despite several hypotheses, our understanding of syringomyelia's pathophysiology remains limited. The hypothesis proposed by Oldfield et al. suggests that piston-like movement of the cerebellar tonsils propels the cerebrospinal fluid (CSF) into the syrinx via the spinal perivascular space. However, a significant question remains unanswered: how does the CSF enter and stay in the syrinx, which has a higher pressure than the subarachnoid space. In the current study, we attempted to verify Oldfield's hypothesis using phase-contrast magnetic resonance imaging (MRI) data from patients with syringomyelia. Methods: We analyzed phase-contrast MRI scans of 18 patients with Chiari-I malformation associated with syringomyelia, all of whom underwent foramen magnum decompression, and 21 healthy volunteers. We obtained velocity waveforms for CSF and brain tissue from regions of interest (ROI) set at the various locations. These waveforms were synchronized at the peak timing of downward CSF flow. We compared the preoperative patient data with the control data and also compared the preoperative patient data with the postoperative patient data. Results: The syrinx shrank in 17 (94%) of the patients, and they experienced significant clinical improvement. When comparing pre- and postoperative MRI results, the only significant difference noted was the preoperative elevated velocity of the cerebellar tonsil, which disappeared post-surgery. The CSF velocities in the subarachnoid space were higher in the preoperative patients than in the controls, but they did not significantly differ in the postoperative MRI. The tonsillar velocity in the preoperative MRI was significantly lower than that of the CSF, suggesting that the elevated tonsillar velocity was more of an effect, rather than the cause, of the elevated CSF velocity. Conclusions: Given these findings, a completely new paradigm seems necessary. We, therefore, propose a novel hypothesis: the generative force of syringomyelia may be the direction-selective resistance to CSF flow in the subarachnoid space.

Long-term Outcomes after Microsurgical Decompression of Lumbar Foraminal Stenosis and Adverse Effects of Preoperative Scoliosis: A Prospective Cohort Study

Lumbar foraminal stenosis is a common disorder, with surgical treatment varying from simple decompression to interbody fusion. It is often associated with degenerative lumbar scoliosis, but the effects of scoliosis on outcomes are unclear. The objectives of this study were to clarify long-term outcomes after microsurgical decompression of lumbar foraminal stenosis through Wiltse’s approach and to determine the effects of scoliosis on these outcomes. A total of 86 consecutive patients with lumbar foraminal stenosis were prospectively followed after microsurgical decompression. They were categorized in multiple subcohorts with follow-up durations ranging from 6 months to 5 years. Outcomes were assessed using the Short Form 36 questionnaire (average physical scores and bodily pain scores). Local Cobb angle of the operative segment was measured preoperatively, and its effects on outcomes were analyzed. Average physical scores improved significantly from 33.8 (95% confidence interval [CI]: 29.1–38.5) preoperatively to 59.5 (95% CI: 54.6–64.3) at 6 months postoperatively and remained improved for 5 years. Bodily pain scores improved significantly from 23.7 (95% CI: 18.7–28.6) preoperatively to 56.3 (95% CI: 51.2–61.6) at 6 months postoperatively and remained improved for 5 years. Patients with preoperative scoliosis (local Cobb angle >10 degrees) had poorer outcomes: average physical scores were worse by 9.6 points (p = 0.07) and bodily pain scores were worse by 12.1 points (p = 0.02), compared with patients without scoliosis (local Cobb angle ≤10 degrees). Microsurgical foraminal decompression produced overall excellent outcomes in patients with lumbar foraminal stenosis. Preoperative scoliosis attenuated these beneficial effects.

NI-08 TRIAL AND PROBLEM OF USING ASL IN INTRAOPERATIVE MRI

INTRODUCTION

Magnetic resonance perfusion imaging is considered to be available as grading of brain tumor and follow-up of brain treatment. One of the methods, arterial spin labeling (ASL), is a test that is useful for patients with renal impairment and contrast agent allergy and has low invasiveness because it does not use a contrast agent. However, there have been no reports of ASL in intraoperative MRI (iMRI).

PURPOSE

In this hospital iMRI (1.5T), it was examined whether ASL could be used to evaluate residual tumor in patients under general anesthesia.

CASE STUDY

A 75-year-old woman with right temporal lobe Glioblastoma. 43-year-old man, left temporal lobe Diffuse astrocytoma. All performed ASL at the time of MRI imaging for navigation before induction of anesthesia just before surgery and iMRI. In all cases, the blood pressure at iMRI was maintained, and Post Label Delay (PLD) calculated the optimal PLD from the carotid artery velocity measured by iMRI, and defined it as 1800–2200 ms, and performed ASL.

RESULTS

Actually, imaging by iMRI was almost difficult to visualize, and reflux was not recognized not only in the tumor but also in the gray matter.

DISCUSSION

The blood flow velocity measurement in the internal carotid artery is performed by the phase contrast method by intraoperative MRI, and the CBF decreases because propofol used during the operation decreases the CBF and also the brain metabolism. However, it has been suggested that it is one of the factors that make evaluation with ASL difficult. Although the iMRI of our hospital is 1.5 T, which is also a subject of investigation, it is thought that there is a limit to ASL imaging in the case of general anesthesia with propofol even from the calculated PLD.

CONCLUSION

ASL in iMRI at our hospital was not useful.

Radical Intracapsular Dissection Technique for Dumbbell-Shaped Spinal Schwannoma with Intradural and Extradural Components

BACKGROUND

Dumbbell-shaped spinal schwannomas with intradural and extradural components are associated with higher complication rates. This may be in part due to epineurial dissection of the extradural component, which inevitably damages the functioning nerve fibers beneath the epineurium and may lead to dural defects that are often difficult to repair.

OBJECTIVE

The objective was to describe a radical intracapsular dissection technique that provides a simpler operative field with no need for dural repair and a better chance of preserving functioning nerve fibers.

METHODS

The technique comprised the following: 1) exposure of the tumor while preserving spinal stability; 2) a single incision encompassing the dura and epineurium; 3) microsurgical dissection of the tumor just beneath the epineurium, preserving the viable nerve fibers; and 4) primary closure of the duroepineurial incision. We describe a case series of 7 patients in whom this type of tumor was excised using this technique.

RESULTS

Gross total excision was achieved in 5 patients. In 1 patient with a large paravertebral component, the remaining tumor was removed with an additional anterior approach. No cerebrospinal fluid leak was noted, and no recurrence was observed in the median follow-up period of 36 months.

CONCLUSIONS

The radical intracapsular dissection technique described herein represents an alternative technique for the removal of dumbbell-shaped spinal schwannomas with intradural and extradural components.

Effect of Sagittal Spinal Balance on the Outcome of Decompression Surgery for Lumbar Canal Stenosis

OBJECTIVE

Although sagittal spinal balance is known to affect the outcome of spinal deformity surgery, its effect on simple decompression surgery is not well understood.

MATERIALS AND METHODS

Patients who underwent unilateral laminotomy for bilateral decompression for lumbar canal stenosis were prospectively enrolled in the study. Before surgery and 6 months after surgery, the following sagittal-alignment parameters were measured: lumbar lordosis (LL), pelvic tilt (PT), pelvic incidence minus lumbar lordosis (PI-LL), and sagittal vertical axis (SVA). At the same time, short-form 36 (SF-36) and Visual Analogue Scale (VAS) were estimated. The patients were divided into the poor postoperative physical score group (P_poor), good postoperative physical score group (P_good), poor postoperative VAS group (V_poor), or good postoperative VAS group (V_good). The postoperative spinopelvic parameters were compared between the physical score and VAS groups, respectively. Finally, we examined the correlation between the spinopelvic parameters and the outcome scores using scatter plots and linear regression analysis.

RESULTS

Fifty-two patients were enrolled into the study. Although the spinopelvic parameters (LL, PT, PI-LL) significantly improved after surgery, the absolute values of improvement were relatively small. The postoperative spinopelvic parameters were significantly worse in the P_poor and the V_poor groups compared with the P_good and the V_good groups, respectively. The correlation analyses also showed that worse postoperative spinopelvic parameters correlated to worse outcome in SF-36 and VAS.

CONCLUSIONS

Sagittal spinal balance significantly affected the outcome of patients undergoing decompression surgery for lumbar canal stenosis, the knowledge of which may serve better patient management.

Influence of Lumbar Lordosis on the Outcome of Decompression Surgery for Lumbar Canal Stenosis

OBJECTIVE

Although sagittal spinal balance plays an important role in spinal deformity surgery, its role in decompression surgery for lumbar canal stenosis is not well understood. To investigate the hypothesis that sagittal spinal balance also plays a role in decompression surgery for lumbar canal stenosis, a prospective cohort study analyzing the correlation between preoperative lumbar lordosis and outcome was performed.

METHODS

A cohort of 85 consecutive patients who underwent decompression for lumbar canal stenosis during the period 2007-2011 was analyzed. Standing lumbar x-rays and 36-item short form health survey questionnaires were obtained before and up to 2 years after surgery. Correlations between lumbar lordosis and 2 parameters of the 36-item short form health survey (average physical score and bodily pain score) were statistically analyzed using linear mixed effects models.

RESULTS

There was a significant correlation between preoperative lumbar lordosis and the 2 outcome parameters at postoperative, 6-month, 1-year, and 2-year time points. A 10° increase of lumbar lordosis was associated with a 5-point improvement in average physical scores. This correlation was not present in preoperative scores.

CONCLUSIONS

This study showed that preoperative lumbar lordosis significantly influences the outcome of decompression surgery on lumbar canal stenosis.

Posterior Paramedian Approach to Ventrally Located Spinal Meningioma

BACKGROUND

To approach a ventral spinal pathology, a lateral viewing angle is often required. However, lateral approaches to the spine are usually more technically demanding and require a certain amount of surgical expertise. In this report, we describe a simple and easy technique to obtain the lateral viewing angle to the ventral spinal pathology.

CASE DESCRIPTION

The technique is demonstrated in a ventrally located meningioma at the C2 level. Axial magnetic resonance imaging showed a square posterior shift of the spinal cord with little lateral space, which necessitated a more lateral viewing angle than the conventional posterior approach. With the patient in a prone position, we made a horizontal skin incision at the level of C2 and unilaterally exposed the right side of the C1 and C2 laminae. We then made a small perpendicular incision on the medial portion of the paravertebral muscles, which we retracted longitudinally. This approach provided an unobstructed lateral view toward the spinal cord. Following a gross total removal of the tumor with minimal cord retraction, the patient made an uneventful recovery. Her preoperative neurologic symptoms completely resolved in 2 months. No significant muscle atrophy was observed on postoperative magnetic resonance imaging at 3 months. There was no long-term complication related to the muscle incision at 1-year follow-up.

CONCLUSION

The posterior paramedian approach is a simple and versatile technique to obtain lateral viewing angle to the spine and useful for approaching lesions residing ventral to the spinal cord.

Microsurgical Posterolateral Foraminotomy on Patients with Adult Isthmic Spondylolisthesis

BACKGROUND

The standard surgical treatment for adult isthmic spondylolisthesis consists of various techniques of arthrodesis supplemented with instrumentation. However, the superiority of this strategy has not been irrefutably proved. Considering the risk associated with the instrumentation surgery, examining a less invasive approach is justified.

METHODS

We describe a series of 9 patients with adult isthmic spondylolisthesis, in whom we microsurgically decompressed the responsible nerve root in the intervertebral foramen through the posterolateral intermuscular approach. Technical details specific to isthmic spondylolisthesis were reviewed. The 2-year outcome was assessed with Short Form 36 and visual analog scale scores.

RESULTS

The mean age of the patients was 68 ± 7 years (standard deviation [SD]). The mean slip rate of spondylolisthesis measured on the preoperative lumbar radiography was 20% ± 12% (SD). All patients successfully underwent the procedure without complications. All the examined scores remained significantly better than the preoperative values 2 years after surgery; the mean visual analog scale score decreased from 7.8 ± 2.8 (SD) preoperatively to 2.8 ± 1.4 (SD) at 2 years (P = 0.008), average physical score of Short Form 36 improved from 33.1 ± 9.7 to 52.5 ± 9.4 (P = 0.001), and the bodily pain score improved from 28.0 ± 13.5 to 55.1 ± 9.7 (P = 0.001).

CONCLUSIONS

Microsurgical decompression through the posterolateral intermuscular approach was effective in producing good 2-year outcome in patients with adult isthmic spondylolisthesis. This procedure may be considered as a less invasive alternative in the surgical treatment of adult isthmic spondylolisthesis.

Development of a genetic marker set to diagnose aspirin-exacerbated respiratory disease in a genome-wide association study

We developed a genetic marker set of single nucleotide polymorphisms (SNPs) by summing risk scores of 14 SNPs showing a significant association with aspirin-exacerbated respiratory disease (AERD) from our previous 660 W genome-wide association data. The summed scores were higher in the AERD than in the aspirin-tolerant asthma (ATA) group (P=8.58 × 10(-37)), and were correlated with the percent decrease in forced expiratory volume in 1 s after aspirin challenge (r(2)=0.150, P=5.84 × 10(-30)). The area under the curve of the scores for AERD in the receiver operating characteristic curve was 0.821. The best cutoff value of the summed risk scores was 1.01328 (P=1.38 × 10(-32)). The sensitivity and specificity of the best scores were 64.7% and 85.0%, respectively, with 42.1% positive and 93.4% negative predictive values. The summed risk score may be used as a genetic marker with good discriminative power for distinguishing AERD from ATA.

A health risk assessment of reclaimed municipal wastewater for industrial and miscellaneous use

The study evaluated the safety of reclaimed water using health risk assessment and biotoxicity tests. The reclaimed water was produced from reverse osmosis and used in industrial and miscellaneous purposes. The health risk assessment was conducted based on the concentrations of detectable pollutants in reclaimed water in a hypothetical scenario. The estimated carcinogenic and non-carcinogenic risks are lower than the generally accepted level. Biotoxicity evaluation included three genotoxicity tests, a chronic toxicity test using medaka fishes, and a subchronic toxicity test using mice. The reclaimed water is not genetically toxic, and does not cause significant chronic effects on these model organisms. These results confirm the safety of using reclaimed water from municipal wastewater treatment plants.

Dorsal spinal arachnoid web diagnosed with the quantitative measurement of cerebrospinal fluid flow on magnetic resonance imaging

An arachnoid web is an abnormal formation of the arachnoid membrane in the spinal subarachnoid space that blocks CSF flow and causes syringomyelia. Although the precise mechanism of syrinx formation is unknown, dissection of the arachnoid web shrinks the syrinx and improves symptoms. Precisely determining the location of the arachnoid web is difficult preoperatively, however, because the fine structure generally cannot be visualized in usual MRI sequences. In this report the authors describe 2 cases of arachnoid web in which the web was preoperatively identified using quantitative CSF flow analysis of MRI. By analyzing cardiac-gated phase-contrast cine-mode MRI in multiple axial planes, the authors precisely localized the obstruction of CSF flow on the dorsal side of the spinal cord in both patients. This technique also revealed a 1-way valve-like function of the arachnoid webs. Imaging led to the early diagnosis of myelopathy related to the derangement of CSF flow and allowed the authors to successfully excise the webs through limited surgical exposure.

Analysis of risk factors for chronic subdural haematoma recurrence after burr hole surgery: optimal management of patients on antiplatelet therapy

OBJECTIVE. Not much is known about surgical management of patients with chronic subdural haematoma (CSDH) treated with antiplatelet or anticoagulant therapy. The aims of this study were to review the surgical outcomes of patients with CSDH and assess the risks of antiplatelet in their surgical management. METHODS. We retrospectively analysed 448 consecutive patients with CSDH treated by one burr hole surgery at our institution. Among them, 58 patients had been on antiplatelet therapy. We discontinued the antiplatelet agents before surgery for all 58 patients. For 51 of these 58 patients (87.9%), early surgery was performed within 0-2 days from admission. We analysed the association between recurrence and patient characteristics, including history of antiplatelet or anticoagulant therapy; age (< 70 years or ≥ 70 years); side; history of angiotensin receptor II blocker, angiotensin converting enzyme blocker, or statin therapy; and previous medical history of head trauma, infarction, hypertension, diabetes mellitus, haemodialysis, seizure, cancer, or liver cirrhosis. RESULTS. Recurrence occurred in 40 patients (8.9%), which was one of the lowest rates in the literature. Univariate analysis showed that only the presence of bilateral haematomas was associated with increased recurrence rate while antiplatelet or anticoagulant therapy did not significantly increase recurrence risk. Also, the recurrence rate from early surgery (0-2 days from drug cessation) for patients on antiplatelet therapy was not significantly higher than that from elective surgery (5 days or more after drug cessation). However, multivariate analysis revealed that previous history of cerebral infarction was an independent risk factor for CSDH recurrence. CONCLUSIOns. Our overall data support the safety of early surgery for patients on the preoperative antiplatelet therapy without drug cessation or platelet infusion. Patients with a previous history of infarction may need to be closely followed regardless of antiplatelet or anticoagulant therapy.

Syringomyelia associated with arachnoid septum at the craniovertebral junction, contradicting the currently prevailing theory of syringomyelia formation

Despite a number of various hypotheses in the literature, the pathophysiology of syringomyelia is still not well understood. In this article, we report two cases of cervical syringomyelia not associated with Chiari I malformation. Both cases had a septum-like structure in the subarachnoid space on the dorsal side of the cord at the craniovertebral junction. Cardiac-gated phase-contrast cine-mode magnetic resonance imaging (MRI) demonstrated decreased cerebrospinal fluid (CSF) flow on the dorsal side of the spinal cord. Surgical excision of this septum, restoring the CSF flow, resulted in a prompt reduction of the syrinx size in both cases. Findings in these cases contradict the currently prevailing hypothesis of syrinx formation that postulate that the piston-like movement of the cerebellar tonsils enhance the pulsatile CSF flow in the spinal subarachnoid space, driving the CSF into the syrinx through the perivascular space of Virchow and Robin. The authors propose that a mechanism based on the decreased pulsatile CSF flow in the spinal subarachnoid space will be more suitable as a hypothesis in studying the pathophyisiology of syringomyelia. These cases also provide an important lesson in managing the patients with syringomyelia not associated with Chiari I malformation.

Osteoradionecrosis of the anterior cranium

Osteoradionecrosis occurs in approximately 10% to 15% of patients following radiation therapy for head and neck cancer. In these patients, it is most commonly reported in sites involving the mandible, but it has also been reported in the maxilla, sphenoid, and temporal bones. The majority of these cases are related to some type of trauma such as dental extraction or intraoral biopsies. However, approximately 40% of these entities occur spontaneously and are felt to be secondary to cell kill in intermediate tissues such as bone and periosteum. Our literature review yielded no previously reported cases of osteoradionecrosis involving the anterior cranium. The following two cases present patients who experienced osteoradionecrosis of their frontal bone flaps following subcranial approaches for tumor resection. Both patients suffered from carcinomas involving the ethmoid sinuses; one tumor was a moderately well-differentiated squamous cell carcinoma, the other a mucinous adenocarcinoma. One patient's radiation therapy consisted of external beam photons; the other patient received external beam neutrons. Treatment for these patients, as well as possible causative factors regarding their osteoradionecrosis, are discussed.

Acute disseminated encephalomyelitis that meets modified McDonald criteria for dissemination in space is associated with a high probability of conversion to multiple sclerosis in Taiwanese patients

BACKGROUND

Patients with acute disseminated encephalomyelitis (ADEM) may relapse and some may ultimately convert to multiple sclerosis (MS); however, no criteria that can predict MS conversion are available to date. Our aim was to describe the clinical and magnetic resonance imaging (MRI) features of patients with an initial ADEM attack and evaluate which MRI criteria can predict conversion to MS.

METHODS

We retrospectively reviewed the records of 36 patients diagnosed with ADEM. We determined clinical signs/symptoms, examined the cerebrospinal fluid (CSF), and performed brain MRI scans and compared the findings between patients who did and did not convert to MS.

RESULTS

Clinical signs/symptoms, and CSF analysis show no significant difference between the two groups. The rate of conversion to MS from ADEM in Taiwanese patients is low (11%) after a mean follow-up period of 28.36 months. Modified McDonald criteria were fulfilled in 19/36 patients: 21% (4/19) of those patients developed MS according to Poser criteria subsequently. Of the other patients (17/36) who did not fulfill these criteria, none converted to MS. (log rank test; P=0.027).

CONCLUSIONS

It is difficult to predict from initial clinical presentations to address which patients with ADEM will convert to MS. Patients with ADEM whose brain MRI findings met the modified McDonald criteria may have clinically isolated syndrome because they have a significantly higher probability of conversion to MS. In contrast, patients whose brain MRI findings did not meeting these criteria may be considered as having classic ADEM because they have a lower probability of conversion to MS.

Brain-derived neurotrophic factor gene polymorphisms and mirtazapine responses in Koreans with major depression

Brain-derived neurotrophic factor (BDNF) is a candidate molecule for influencing the clinical response to antidepressant treatment. The aims of this study were to determine the relationship between the Val66Met polymorphism in the BDNF gene and the response to mirtazapine in 243 Korean subjects with major depressive disorder (MDD). The reduction in the Hamilton Depression score over the 8-week treatment period was not influenced by BDNF V66M genotypes. A marginal effect of genotype on somatic anxiety score was observed at baseline (P = 0.047 in the dominant model). However, genotype-time interaction had no effect on somatic anxiety score after the 8-week a treatment period. Plasma BDNF levels tended to increase during mirtazapine treatment, although without statistical significance (P = 0.055). After 8 weeks of mirtazapine treatment, plasma BDNF levels were higher in Met allele homozygotes (1499.7 ± 370.6 ng/mL) than in Val allele carriers (649.7 ± 158.5 ng/mL, P = 0.049). Our results do not support the hypothesis that the Val66Met promoter polymorphism in the BDNF gene influences the therapeutic response to mirtazapine in Korean MDD patients. However, our data indicate that this polymorphism results in increased plasma BDNF after mirtazapine treatment.

GM2 gangliosidosis variant 0 (Sandhoff-like disease) in a family of toy poodles

BACKGROUND

GM2 gangliosidosis variant 0 (human Sandhoff disease) is a lysosomal storage disorder caused by deficiencies of acid β-hexosaminidase (Hex) A and Hex B because of an abnormality of the β-subunit, a common component in these enzyme molecules, which is coded by the HEXB gene.

OBJECTIVE

To describe the clinical, pathological, biochemical, and magnetic resonance imaging (MRI) findings of Sandhoff-like disease identified in a family of Toy Poodles.

ANIMALS

Three red-haired Toy Poodles demonstrated clinical signs including motor disorders and tremor starting between 9 and 12 months of age. The animals finally died of neurological deterioration between 18 and 23 months of age. There were some lymphocytes with abnormal cytoplasmic vacuoles detected.

METHODS

Observational case study.

RESULTS

The common MRI finding was diffuse T2-hyperintensity of the subcortical white matter in the cerebrum. Bilateral T2-hyperintensity and T1-hypointensity in the nucleus caudatus, and atrophic findings of the cerebrum and cerebellum, were observed in a dog in the late stage. Histopathologically, swollen neurons with pale to eosinophilic granular materials in the cytoplasm were observed throughout the central nervous system. Biochemically, GM2 ganglioside had accumulated in the brain, and Hex A and Hex B were deficient in the brain and liver. Pedigree analysis demonstrated that the 3 affected dogs were from the same family line.

CONCLUSIONS AND CLINICAL IMPORTANCE

The Sandhoff-like disease observed in this family of Toy Poodles is the 2nd occurrence of the canine form of this disease and the 1st report of its identification in a family of dogs.

A multicenter trial of the efficacy and safety of 0.03% tacrolimus ointment for atopic dermatitis in Korea

BACKGROUND

Atopic dermatitis is a chronically relapsing, common inflammatory skin disease, which significantly affects quality of life negatively in many respects. Topical steroids are the mainstay of atopic dermatitis treatment but they carry the risk of local side effects. A topical formulation of tacrolimus, a macrolide calcineurin inhibitor, has recently been developed.

OBJECTIVE

To evaluate the efficacy and safety of 0.03% tacrolimus ointment for the treatment of moderate to severe atopic dermatitis in Korea.

METHODS

An open, non-comparative, multi-center study with 4 weeks' follow-up was performed. A total of 180 patients (aged 2-57 years old) were enrolled. Tacrolimus ointment (0.03%) was applied to all involved areas twice daily. Efficacy was evaluated by an investigator's global assessment, the eczema area and severity index score, and by the patient's assessment of pruritus and clinical response at baseline, and after weeks 1, 2 and 4. Dermatology life quality index (DLQI), children's DLQI (CDLQI) and toddler's DLQI were assessed at baseline and at week 4. The safety assessment included monitoring all adverse events and clinical laboratory values.

RESULTS

All efficacy parameters were improved. The mean EASI (eczema area and severity index) score was 19.7 at baseline and reduced to 8.0 at the end of the study. Moderate improvement was observed by the investigator's global assessment after 4 weeks' treatment. A marked decrease of pruritus was observed, and mild or moderate improvement was observed by patients' global assessments after the treatment period. Significant benefits in terms of quality of life in adults and children with atopic dermatitis were obtained. The most common adverse events associated with tacrolimus treatment were transient skin burning sensation (45.3%) and pruritus (41.6%) at the site of application.

CONCLUSION

0.03% tacrolimus ointment should be considered effective and safe in both Korean children and adults with moderate to severe atopic dermatitis.

Incidence and clinical behavior of papillary thyroid carcinoma in renal allograft recipients: a single center experience

The chronic use of immunosuppressive therapy in transplant recipients increases the long-term risk for carcinoma. However, there is insufficient knowledge regarding the incidence and biological behavior of papillary thyroid carcinomas (PTC) in renal allograft recipients. In the present study we examined the incidence and biological behavior of PTCs among 1739 patients transplanted between January 1986 and December 1999 who had been followed for a mean period of 137 months (range, 84-238 months). During the follow-up, 129 (7.4%) recipients were identified to display posttransplantation malignancies, including 12 (0.7%) with PTCs. The 6 male and 6 female patients had a mean age of 41 years (range, 23-57 years). Nine cases (incidentalomas) were diagnosed based on ultrasonographic (US) screening. Eight of those 9 were TNM stage I, 2 of the 3 clinical carcinomas were TNM stage IVa. During a mean follow-up of 94 months (range, 18-159 months), 2 (16.7%) PTC patients developed locoregional recurrence, but no patients showed distant metastases. These data showed that recipients had a higher incidence of PTC compared with the general Korean population (0.7% vs 0.02%). Posttransplantation PTC tended to show no difference in gender distribution, and was often associated with aggressive lymphatic metastasis. However, most incidentalomas showed favorable treatment outcomes. In conclusion, routine surveillance of the thyroid gland using US screening is recommended to ensure early detection, treatment, and favorable prognosis of PTC.

The negative hydrogen Penning ion gauge ion source for KIRAMS-13 cyclotron

The cold-cathode-type Penning ion gauge (PIG) ion source for the internal ion source of KIRAMS-13 cyclotron has been used for generation of negative hydrogen ions. The dc H-beam current of 650 microA from the PIG ion source with the Dee voltage of 40 kV and arc current of 1.0 A is extrapolated from the measured dc extraction beam currents at the low extraction dc voltages. The output optimization of PIG ion source in the cyclotron has been carried out by using various chimneys with different sizes of the expansion gap between the plasma boundary and the chimney wall. This paper presents the results of the dc H-extraction measurement and the expansion gap experiment.

Ultrasonic bone curettage for optic canal unroofing and anterior clinoidectomy. Technical note

Extradural unroofing of the optic canal and subsequent mobilization of the optic nerve is a useful technique in the surgical treatment of parasellar tumors; however, the drilling procedure itself is associated with the risk of optic nerve damage. A safer technique would certainly be beneficial. The ultrasonic bone curette is a device developed in Japan for safer bone removal. Its use in intradural anterior clinoidectomy and opening of the internal auditory meatus has been reported before. In this article the authors describe their experience in using this device for extradural unroofing of the optic canal in patients with parasellar tumors. Between March 2002 and November 2004, the aforementioned technique was used in the treatment of eight patients with parasellar tumors. After undertaking a frontotemporal craniotomy and orbital osteotomy, an ultrasonic bone curette was used to unroof the optic canal via an epidural approach; in five cases anterior clinoidectomy was added subsequently. Using an ultrasonic bone curette, unroofing of the optic canal was completed safely and required much less expertise than that required for standard drilling. The mortality and major morbidity rates were 0%. The visual function outcome was satisfactory, with the overall visual status improving in all seven patients in whom this symptom was present preoperatively. The ultrasonic bone curette makes the unroofing of the optic canal safer and easier, possibly improving the visual outcome of patients undergoing surgery for parasellar tumors.

Comparison of the antibody in lymphocyte supernatant (ALS) and ELISPOT assays for detection of mucosal immune responses to antigens of enterotoxigenic Escherichia coli in challenged and vaccinated volunteers

In the present study we compared the ELISPOT and antibody in lymphocyte supernatants (ALS) assays as surrogate measures of mucosal immunity. In separate studies, 20 inpatient volunteers received oral doses of 6 x 10(8) or 4 x 10(9)cfu of ETEC strain E24377A (LT+, ST+, CS1+, CS3+) and 20 subjects received 1 (n = 9) or 2 (n = 11) oral doses of the attenuated ETEC vaccine, PTL-003 expressing CFA/II (CS1+ and CS3+) (2 x 10(9)cfu/dose). Peripheral blood mononuclear cells (PBMCs) from all subjects were assayed for anti-colonization factor or toxin-specific IgA antibody responses using the ALS and ELISPOT procedures. ALS responses were measured using a standard ELISA, as well as by time-resolved fluorescence (TRF). Following challenge with E24377A, significant anti-CS3, CS1 and LT ALS responses were detected in the lymphocyte supernatants of 75-95% of the subjects. A similar proportion (75%) of subjects mounted an ALS response to CFA/II antigen after vaccination with the PTL-003 vaccine. Inter-assay comparisons between ALS and ELISPOT methods also revealed a high degree of correlation in both immunization groups. ALS sensitivity versus the ELISPOT assay for LT, CS3 and CS1-specific responses following challenge were 95%, 94% and 78%, respectively and 83% for the ALS response to CFA/II antigen after vaccination with PTL-003. Correlation coefficients for the LT and CS3 antigens were 0.94 (p<0.001) and 0.82 (p<0.001), respectively after challenge and 0.78 (p<0.001) after vaccination. The association between ALS and ELISPOT for the CS1 antigen was however, significant only when ALS supernatants were tested by TRF (r = 0.91, p<0.001). These results demonstrate the value and flexibility of the ALS assay as an alternative to ELISPOT for the measurement of mucosal immune responses to ETEC antigens, particularly when the complexities of ELISPOT may make it impractical to perform.

Simulation of the natural history of cerebral aneurysms based on data from the International Study of Unruptured Intracranial Aneurysms

Object

Despite recent publications of large-scale study data, controversy over the management of unruptured cerebral aneurysms continues. The low rupture rates in the International Study of Unruptured Intracranial Aneurysms (ISUIA) apparently contradicted surgeons’ experiences with ruptured aneurysms. In the present study, based on data from the ISUIA, a mathematical model describing the natural history of cerebral aneurysms was developed. With this model, the author aimed to examine the validity of data from the ISUIA and to provide a better treatment guideline for unruptured aneurysms.

Methods

The author made a computer simulation of the natural history of cerebral aneurysms that was used to calculate such figures as the prevalence of unruptured aneurysms, incidence of subarachnoid hemorrhage (SAH), and age and size distribution of both unruptured and ruptured aneurysms. The lifetime lesion rupture probability for individual patients with various ages and aneurysm sizes was also computed, thereby providing a useful index to help patients in the medical decision-making process.

The computer model produced a sample of unruptured aneurysms in the general population with a prevalence of 4.2% and a median diameter of 5.8 mm. These unruptured aneurysms—affected by the rupture rate reported in the ISUIA—had a yearly SAH incidence of 19.6 per 100,000 persons. The median diameter of these aneurysms was 9.4 mm.

Conclusions

Findings in the present study validated the results of the ISUIA by showing that the seemingly low rupture rates could explain the statistical data for ruptured aneurysms. With the featured model, the author calculated the lifetime probability of lesion rupture—a useful measure for deciding on the optimal treatment for unruptured aneurysms.

Modulatory influence of sodium 2-propenyl thiosulfate from garlic on cyclooxygenase activity in canine platelets: possible mechanism for the anti-aggregatory effect

We previously found that sodium 2-propenyl thiosulfate (2PTS) has an anti-aggregatory effect in vitro on both canine and human platelets at relatively low concentrations, but the extent of aggregation tends to return to the control level at high concentrations. To clarify the mechanism of this modulatory influence of 2PTS on the aggregation of platelets, we investigated the effects of 2PTS on cyclooxygenase (COX) activity and the reduced glutathione (GSH) concentration in canine platelets. Platelet COX activity was inhibited by 2PTS in a dose-dependent manner up to 0.1 mM, but tended to return to the control level at 1 mM. In contrast, the platelet GSH concentration decreased in a dose-dependent manner after treatment with 2PTS and a significant decrease was observed at 0.1 mM (P<0.05) and 1 mM (P<0.001). Furthermore, the activity of purified COX-1 was directly inhibited by addition of GSH in a dose-dependent manner. From these results, we conclude that the 2PTS-induced inhibition of platelet aggregation occurs as a result of inhibition of COX activity. Additionally, 2PTS may have a modulatory effect on platelet aggregation by affecting the platelet GSH concentration.

Subarachnoid pressure—dependent change in syrinx size in a patient with syringomyelia associated with adhesive arachnoiditis

✓ The pathophysiology of syringomyelia is still not well understood. Current prevailing theories involve the assumption that cerebrospinal fluid (CSF) flows into the syrinx from the subarachnoid space through the perivascular space of Virchow—Robin. Reported here is the case of a patient with syringomyelia in which this course is clearly contradicted.

This patient with a holocord syrinx associated with adhesive arachnoiditis was treated 3 years previously with insertion of a subarachnoid—peritoneal shunt and had recently experienced worsening myelopathy. On surgical exploration, the shunt system was functioning normally. The medium-pressure shunt valve was replaced with an adjustable valve with a higher closing pressure setting, thus increasing the CSF pressure in the subarachnoid space. Contrary to prevailing theories, this procedure markedly reduced the size of the syrinx.

This case provides direct evidence that the syrinx size is inversely related to subarachnoid CSF pressure and supports the hypothesis that the pressure gradient across the spinal cord parenchyma is the force that generates syringes in syringomyelia.

Altered function of lumbar nerve roots in patients with transitional lumbosacral vertebrae

STUDY DESIGN

A retrospective study was conducted on the preoperative neurologic symptoms of patients with lumbar herniated discs.

OBJECTIVE

To evaluate the possibility that the muscle innervation pattern and the sensory dermatomes of lumbar nerve roots are altered when a lumbosacral transitional vertebra is present.

SUMMARY OF BACKGROUND DATA

In 1962, McCulloch et al suggested with intraoperative recordings that the innervation pattern of the lumbar nerve roots may be altered when a lumbosacral transitional vertebra is present. However, this result was not repeated in the study by Young et al in 1983.

METHODS

We retrospectively reviewed the charts of 62 consecutive patients who underwent microdiscectomy for lumbar herniated discs. Lumbarized S1 vertebra was present in 10 of 62 patients (16%). Among these 10 patients, 8 had herniated discs at L5-S1 compressing the S1 nerve root. In the 52 normally configured patients, 22 had herniated discs at L5-S1 compressing the S1 nerve root, and 15 had herniated discs at L4-L5 compressing the L5 nerve root. The preoperative neurologic symptoms caused by the S1 nerve root compression in the patients with lumbarized S1 vertebrae were compared with the symptoms caused by either L5 or S1 nerve root compression in the patients with normal configuration.

RESULTS

The distribution of motor weakness caused by the S1 nerve root compression was significantly different between the patients with lumbarized S1 and those with the normal configuration. The motor weakness caused by the S1 root compression in the patients with lumbarized S1 was similar to that of the L5 nerve root compression in the normal configuration. Analysis of sensory symptoms showed similar results.

CONCLUSIONS

Our findings suggest that the function of lumbosacral nerve roots is altered in patients with lumbarized S1 so that the S1 nerve root serves the usual function of the L5 nerve root.

Theoretical analysis of the pathophysiology of syringomyelia associated with adhesive arachnoiditis

OBJECTIVE

To apply a theoretical model to analyse the derangement of cerebrospinal fluid (CSF) dynamics in syringomyelia associated with adhesive arachnoiditis.

METHODS

An electrical circuit model of CSF dynamics in the spine was used. With this model, the derangement of CSF dynamics in adhesive arachnoiditis was simulated. The effects of various surgical procedures were then analysed, such as syringo-subarachnoid shunting, subarachnoid bypass, and foramen magnum decompression.

RESULTS

When CSF flow in the subarachnoid space was obstructed at a certain point, the pressure inside the spinal cord increased in the segment immediately distal to the blockage. This location of increased pressure corresponded to the preferred site of syrinx formation in adhesive arachnoiditis. Syringo-subarachnoid shunting, subarachnoid bypass, and foramen magnum decompression were all effective at reducing this pressure gradient.

CONCLUSIONS

Blockage of the spinal subarachnoid CSF pathway produces a relative increase in the pressure inside the spinal cord distal to the blockage point. Repetitive formation of this pressure gradient then induces CSF leakage into the spinal parenchyma, leading to the formation of syringomyelia. Using this model, alternative surgical procedures could be suggested that might be effective in treating this disease.

The use of evoked potentials for clinical correlation and surgical outcome in cervical spondylotic myelopathy with intramedullary high signal intensity on MRI

OBJECTIVE

To investigate the use of motor evoked potentials (MEPs) and somatosensory evoked potentials (SEPs) for clinical significance and surgical outcome in patients with cervical spondylotic myelopathy (CSM) with intramedullary high signal intensity on T2 weighted MRI.

METHODS

Forty nine patients were scored according to the modified Japanese Orthopaedic Association (JOA) score for cervical myelopathy. MEP and SEP studies were performed and the results were categorised as normal or abnormal. Thirty nine patients who had received surgical decompression were re-evaluated after 6 months. Surgical outcome was represented by the recovery ratio of the JOA score.

RESULTS

Abnormal MEPs were observed in 44 patients (arm: 43; leg: 30). Abnormal SEPs were found in 32 patients: (median: 24; tibial: 23). Patients with abnormal SEPs had a worse JOA score than those with normal SEPs. Thirty nine patients received surgical treatment. Patients younger than 55 had better recovery ratios than those who were 55 or older (p = 0.005, two sample Student's t test). Patients with normal median SEPs also had better recovery ratios than those with abnormal median SEPs (p = 0.007, two sample Student's t test). Among median SEP variables, only N9-20 was significantly associated with recovery ratio (p = 0.016, stepwise linear regression), with age factor controlled (p = 0.025, stepwise linear regression).

CONCLUSION

Arm MEP was the most sensitive EP test for detecting myelopathy in patients with chronic CSM. Median and tibial SEPs correlated well with the severity of myelopathy while normal median SEPs correlated with good surgical outcome. Among median SEP variables, only N9-20 correlated with surgical outcome.

Acceleration of superoxide generation in polymorphonuclear leukocytes and inhibition of platelet aggregation by alk(en)yl thiosulfates derived from onion and garlic in dogs and humans

We recently identified sodium n-propyl thiosulfate (NPTS) and sodium 2-propenyl thiosulfate (2PTS) from boiled onion and garlic, respectively, as causative agents of hemolytic anemia in dogs. We present here data concerning the effects of these alk(en)yl thiosulfates on superoxide (O(2)(-)) generation in peripheral polymorphonuclear leukocytes (PMNs) and on adenosine 5'-diphosphate (ADP)-induced platelet aggregation in dogs and humans in vitro. Both NPTS and 2PTS increased O(2)(-) generation significantly (P<0.05 at 1mM NPTS, P<0.005 at 0.1 and 1mM 2PTS) and reduced its reaction time significantly (P<0.05 between 0.01 and 1mM NPTS and at 1mM 2PTS) in canine PMNs stimulated by phorbol 12-myristate 13-acetate, compared with the control without alk(en)yl thiosulfates. However, a tendency to return to the control level was observed at 10mM of the alk(en)yl thiosulfates in both O(2)(-) generation and its reaction time. Although NPTS and 2PTS did not exert any significant effect on the O(2)(-) generation in human PMNs, 2PTS reduced its reaction time significantly (P<0.05) at 1 and 10mM compared with the control, showing that 2PTS accelerated O(2)(-) generation in human PMNs. The difference in effects on O(2)(-) generation may be due to that in susceptibility to alk(en)yl thiosulfates between canine and human PMNs. On the other hand, NPTS and 2PTS were shown to significantly inhibit ADP-induced platelet aggregation at 0.01mM (P<0.01) in canine platelets and at 0.001-0.1mM (P<0.05) in human platelets. In contrast, the maximal aggregation percentage returned to the control level at 1mM of alk(en)yl thiosulfates in both canine and human platelets. From these results, we conclude that NPTS and 2PTS have the potential to promote immune functions and prevent cardiovascular diseases.

Hypothesis on the pathophysiology of syringomyelia based on simulation of cerebrospinal fluid dynamics

OBJECTIVES

Despite many hypotheses, the pathophysiology of syringomyelia is still not well understood. In this report, the authors propose a hypothesis based on analysis of cerebrospinal fluid dynamics in the spine.

METHODS

An electric circuit model of the CSF dynamics of the spine was constructed based on a technique of computational fluid mechanics. With this model, the authors calculated how a pulsatile CSF wave coming from the cranial side is propagated along the spinal cord.

RESULTS

Reducing the temporary fluid storage capacity of the cisterna magna dramatically increased the pressure wave propagated along the central canal. The peak of this pressure wave resided in the mid-portion of the spinal cord.

CONCLUSIONS

The following hypotheses are proposed. The cisterna magna functions as a shock absorber against the pulsatile CSF waves coming from the cranial side. The loss of shock absorbing capacity of the cisterna magna and subsequent increase of central canal wall pressure leads to syrinx formation in patients with Chiari I malformation.

Minimally invasive open thyroidectomy

We recently developed a new surgical technique for carrying out thyroidectomy, to minimize tissue trauma by obviating unnecessary neck exploration. This report describes our technique of performing minimally invasive open thyroidectomy and compares the results with those of conventional thyroidectomy. Minimally invasive open thyroidectomy was performed by making a small skin incision, 3.0-4.5cm long, and approaching the thyroid directly via a transverse division of the strap muscles without raising skin flaps. The outcomes of 466 patients who underwent a minimally invasive open thyroidectomy were retrospectively compared with those of 437 patients who underwent conventional thyroidectomy for various types of thyroid nodules. There was no significant difference in the extent of surgery between the group of patients who underwent minimally invasive thyroidectomy and the group of patients who underwent conventional thyroidectomy. However, the length of the skin incision, at 3.7 +/- 0.7 vs 9.6 +/- 3.3 cm, respectively, operative time, at 57.6 +/- 11.7 vs 85.2 +/- 32.3 min, respectively, blood loss, at 18.4 +/- 15.3 vs 43.1 +/- 21.8 ml, respectively, and hospital stay, at 1.6 +/- 0.5 vs 4.3 +/- 1.6 days, respectively, were significantly reduced in the minimally invasive open thyroidectomy group (P < 0.05). Moreover, the number of patients who required postoperative analgesia was significantly less in the minimally invasive open thyroidectomy group. These results show that minimally invasive open thyroidectomy provides surgeons with a clear operative field, and that it has proven to be simple, safe, and practical for selected patients.

Ultrasonographic mass screening for thyroid carcinoma: a study in women scheduled to undergo a breast examination

This study was carried out to clarify the sensitivity of ultrasonographic mass screening for thyroid carcinoma. Between December 1997 and July 1998, a total of 1401 subjects who were scheduled to undergo either a breast examination or a follow-up examination for breast cancer were enrolled in this study. Patients with thyroid nodules were classified into two groups according to their potential risk for malignancy based on the ultrasonographic findings. Ultrasonographic high-risk patients for thyroid cancer underwent an ultrasound guided fine-needle aspiration biopsy (FNAB) and were advised to undergo a thyroidectomy based on the FNAB results. The characteristics of the thyroid cancer patients detected by mass screening were then compared with those of 106 consecutive female patients with clinical thyroid cancer during the same period. Thyroid nodules were detected in 353 (25.2%) of the subjects, 94 (26.6%) of whom were placed in the high-risk group for thyroid cancer. Among the 94 high-risk patients, 43 underwent a thyroidectomy and 37 turned out to have thyroid carcinomas. The detection rate for thyroid cancer was 2.6% for all subjects. The tumor size was significantly smaller than that of the clinically detected cancer group (P < 0.05). Ultrasonographic mass screening for thyroid carcinoma in women who require breast examinations is thus considered to be effective for the detection of subclinical thyroid carcinoma.

Detection of anti-lipopolysaccharide antibodies to Vibrio cholerae O1 and O139 using a novel microtiter limulus amebocyte lysate (LAL) assay

This paper describes a new assay for measuring antibodies to lipopolysaccharide (LPS) of Vibrio cholerae using blocking of the limulus amebocyte lysate (LAL) reaction in a microtiter plate. When V. cholerae LPS was coated onto a microtiter plate, and then LAL reagent was added, a typical gel reaction occurred. However, when the LPS-coated plates were first incubated with serum containing anti-cholera antibodies, the gel reaction did not occur. Blocking of the gel reaction was serotype specific, in that anti-O1 serum blocked the O1 LAL reaction but not the O139 LAL reaction, and anti-O139 serum neutralized the O139 reaction but not the O1 reaction. Preliminary data suggested that the LAL titers were comparable to the vibriocidal titers but that titers using the LAL assay may have been slightly higher. This study showed that antibodies to V. cholerae blocked the LAL reaction and suggested that the LAL blocking assay could be applicable for determining antibodies to other endotoxin-containing bacteria and microorganisms.

Surgical decision-making on cerebral cavernous malformations

This study is an attempt to clarify surgical decision-making on cerebral cavernous malformations based on the data available in the literature. Using a mathematical model, we calculated the morbidity-free survival curves of the patients harboring cerebral cavernous malformations. Using these survival curves, we calculated the morbidity-free life expectancies of the patients at certain age undergoing either natural course or surgery. For superficially located lesions, permissible surgical risks were very small ranging from 0.4 to 2.8 percent of combined morbidity and mortality. The surgical gain of morbidity free life expectancy was also very small (0.0-1.1 years) irrespective of patient's age or eloquence of the location. For deep lesions, the permissible risk of surgery was very large, ranging from 64.1% for a 20-year-old and 31.4% for a 60-year-old patient. The gain of morbidity-free life expectancy was also large for younger patients (17-25 years for 20-year-old patients), but this gain rapidly decreased as the patient's age grew older, becoming 1.1 to 3.1 years for 60-year-old patients. Surgery seems to be justified for younger patients with deep lesions. There seems to be little indication for surgery of superficial lesions as far as the risk of bleeding is concerned.

Multiple transcription-factor genes are early targets of phytochrome A signaling

The phytochrome family of sensory photoreceptors directs adaptational changes in gene expression in response to environmental light signals. Using oligonucleotide microarrays to measure expression profiles in wild-type and phytochrome A (phyA) null-mutant Arabidopsis seedlings, we have shown that 10% of the genes represented on the array are regulated by phyA in response to a continuous far-red light signal. Strikingly, 44% of the genes responding to the signal within 1 h are predicted to encode multiple classes of transcriptional regulators. Together with previous data, this observation suggests that phyA may regulate seedling photomorphogenesis by direct targeting of light signals to the promoters of genes encoding a master set of diverse transcriptional regulators, responsible in turn for orchestrating the expression of multiple downstream target genes in various branches of a phyA-regulated transcriptional network.

In silico mining of EST databases for novel pre-implantation embryo-specific zinc finger protein genes

Progress in the understanding of early mammalian embryo development has been severely hampered by scarcity of study materials. To circumvent such a constraint, we have developed a strategy that involves a combination of in silico mining of new genes from expressed sequence tags (EST) databases and rapid determination of expression profiles of the dbEST-derived genes using a PCR-based assay and a panel of cDNA libraries derived from different developmental stages and somatic tissues. We demonstrate that in a random sample of 49 independent dbEST-derived zinc finger protein genes mined from a mouse embryonic 2-cell cDNA library, more than three-quarters of these genes are novel. Examination of characteristics of the human orthologues derived from these mouse genes reveals that many of them are associated with human malignancies. Expression studies have further led to the identification of three novel genes that are exclusively expressed in mouse embryos before or up to the 8-cell stage. Two of the genes, designated 2czf45 and 2czf48 (2czf for 2-cell zinc finger), are zinc finger protein genes coding for a RBCC protein with a RFP domain and a protein with three C2H2 fingers, respectively. The third gene, designated 2cpoz56, codes for a protein with a POZ domain that is often associated with zinc finger proteins. These three genes are candidate genes for regulatory or other functions in early embryogenesis. The strategy described in this report should generally be applicable to rapid and large-scale mining of other classes of rare genes involved in other biological and pathological processes. Mol. Reprod. Dev. 59:249-255, 2001.

Allergenicity test of genetically modified soybean in Sprague Dawley rats

Allergenicity of genetically-modified (GM) soybean was evaluated in male Sprague Dawley rats. To confirm the GM soybean used in this study, the polymerase chain reaction (PCR) was performed using the chromosomal DNA of soybeans. The PCR result provided the clear discrimination of genetically-modified (GM) soybeans. To evaluate the allergenicity of GM soybean and non-GM control one, the soybean homogenate was sensitized subcutaneously 3 times a week for 3 weeks. The doses of soybean were 0, 2 and 20 mg/kg in the protein basis. A week after the last sensitization, antisera were recovered from individual animals. When the sera were injected intradermally on the clipped back of unsensitized rats with various dilutions, followed by a challenge with 20 mg/kg of soybean homogenate containing 1% Evans blue, no sign of passive cutaneous anaphylaxis reaction was detected. In addition, when the sera were treated in the cultures of peritoneal mast cells, the increase of histamine release by anti-(GM soybean) sera was not observed when compared to that by anti-(non-GM soybean) sera. The present results indicate that the GM soybean might not act as a strong allergen in male Sprague Dawley rats.