Lessons from the diagnosis and treatment of spontaneous vertebral arterial dissection. Case report

SUMMARY

A 36-year-old man presented a sudden left occipital headache and right limb weakness after tooth-brushing. Conventional catheter digital subtraction angiography (DSA) showed a left VA occlusion at the crotch of the posterior inferior cerebellar artery. Four days later, the patient got worse. The angiogram showed the left vertebral artery had reopened and the basilar trunk occluded above the AICA. He died two days later and autopsy demonstrated a dissection of the basilar arteries. Based on the autopsy data from the patient in this study, we suggest that the BA dissection might be due to left VA dissection, and placing a stent on the juncture between the uninjured VA and the basilar trunk might be an effective method to prevent fatal BA occlusion.

Curing of four different plasmids in Yersinia pestis using plasmid incompatibility

AIMS

Plasmids are critical for the pathogenicity of Yersinia pestis. In order to carry out a systematic investigation of their role in pathogenesis, we cured plasmids from Y. pestis.

METHODS AND RESULTS

Each plasmid's replicon of Y. pestis was cloned into plasmid pEX18Gm containing a counter-selectable sacB gene, and was then introduced into Y. pestis strain 201 by electroporation. Strains containing recombinant plasmids were cultivated under antibiotic selection. The resultant plasmid-curing colonies, identified by specific polymerase chain reactions, were then cured off pEX18Gm under sucrose pressure. This method was used to successfully cure all four plasmids of Y. pestis, singly or in different combinations.

CONCLUSIONS

Naturally evolving plasmids in Y. pestis are difficult to remove by conventional curing methods. We employed a method based on plasmid incompatibility to cure the plasmids from Y. pestis, which confirmed the efficacy of this method for curing plasmids with different types of replicons from one bacterium.

SIGNIFICANCE AND IMPACT OF THE STUDY

There have been no reports on the curing of multiple plasmids by using replication mechanisms from one bacterium with this technique. In the present study, we were able to successfully apply this methodology to cure four plasmids from Y. pestis, confirming its feasibility.

Transition from Mott insulator to superconductor in GaNb4Se8 and GaTa4Se8 under high pressure

Electronic conduction in GaM4Se8 (M=Nb,Ta) compounds with the fcc GaMo4S8-type structure originates from hopping of localized unpaired electrons (S=1 / 2) among widely separated tetrahedral M4 metal clusters. We show that under pressure these systems transform from Mott insulators to a metallic and superconducting state with T(C)=2.9 and 5.8 K at 13 and 11.5 GPa for GaNb4Se8 and GaTa4Se8, respectively. The occurrence of superconductivity is shown to be connected with a pressure-induced decrease of the MSe6 octahedral distortion and simultaneous softening of the phonon associated with M-Se bonds.

Direct repair of defect in lumbar spondylolysis and mild isthmic spondylolisthesis by bone grafting, with or without facet joint fusion

Forty-six patients with lumbar spondylolysis and mild isthmic spondylolisthesis were managed with direct repair of the defect with or without facet joint fusion in the affected segment. There were 24 males and 22 females, ranging in age from 15 to 56 years (average, 38.2 years). These patients had experienced clinical symptoms due to spondylolysis for between 4 months and 20 years (average, 5.3 years). Of 46 patients, 28 had no spondylolisthesis, 11 had Meyerding grade I vertebral slippage and 7 had grade II. Direct repair of 98 defects was performed on these patients. Twenty-six patients, in whom the disc adjacent to the defect was determined as degenerative by magnetic resonance imaging (MRI), simultaneously underwent facet joint fusion; 17 in one segment and 9 in two segments. The average period of follow-up was 50 months (24-92 months). Ninety-four defects achieved bony healing. As a result, 28 patients were graded as having an excellent outcome, 15 good, and 3 fair. Bone grafting in the defects achieves union between the loose lamina and the anterior element of lumbar vertebrae, and reconstructs the anatomic structure and physiologic functions of the lumbar vertebrae. There was no significant difference in outcome between the spondylolytic/spondylolisthetic patients with non-degenerative disc, who were treated with direct repair of defect only, and those with degenerative disc, who additionally underwent a fusion procedure (P > 0.05). The present series demonstrates a satisfactory result and a high rate of bony healing of the pars defect by this operative procedure in patients with lumbar spondylolysis and mild isthmic spondylolisthesis. Preoperative assessment of the disc degeneration with MRI is of great assistance in making the protocol choice of whether to opt for fusion.

Studies on the oxidative addition reaction of 1,1-dibromo-1-alkenes, alpha-dehalopalladation, and the intramolecular bis(carbopalladation) reaction of alkenes. An efficient entry to fused bicycles

Twenty-three examples of 1,1-dihalo-1-alkenes were synthesized by the conventional alkylation methods. The oxidative addition reactions of 1,1-dibromo-2,2-diphenylethene or 1, 1-dibromo-2-phenylpropene with a stoichiometric amount of Pd(PPh(3))(4) afforded 1,2-diphenylacetylene and 1-phenylpropyne, respectively, indicating that alpha-dehalopalladation reaction occurred to afford vinylic carbene intermediates. However, alpha-dehalopalladation reaction was not observed in all 1, 1-dihalo-1-alkenes containing an extra C=C bond suitable for cyclic carbopalladation under the current reaction conditions probably due to the fast cyclic carbopalladation reaction of 40A-type of palladium intermediates; A series of bicycles, i.e., fused 5,6-, 6, 6-, 6,7-, and 7,7-bicyclic compounds, were prepared efficiently via this bicyclic carbopalladation protocol. Under condition A, within 0. 5 h, 10 afforded the monocyclic product 37 in 79%. With prolonged reaction time, 37 was converted to bicycle 36. Even with isolated 37, the corresponding reaction under condition A afforded 36 in 92% NMR yield, indicating a stepwise oxidative addition-cyclic carbopalladation-beta-elimination mechanism for this bicyclization reaction.

Effects of direct current on dog liver: possible mechanisms for tumor electrochemical treatment

Mechanisms of tumor electrochemical treatment (ECT) were studied using normal dog liver. Five physical and chemical methods were used. Two platinum electrodes were inserted into an anesthetized dog's liver at 3 cm separation. A voltage of 8.5 V direct current (DC) at an average current of 30 mA was applied for 69 min; total charge was 124 coulombs. Concentrations of selected ions near the anode and cathode were measured. The concentrations of Na+ and K+ ions were higher around the cathode, whereas the concentration of Cl- ions was higher around the anode. Water contents and pH were determined near the anode and the cathode at the midpoint between the two electrodes and in an untreated area away from the electrodes. Hydration occurred around the cathode, and dehydration occurred around the anode. The pH values were 2.1 near the anode and 12.9 near the cathode. Spectrophotometric scans of the liver sample extract were obtained, and the released gases were identified by gas chromatography as chlorine at the anode and hydrogen at the cathode. These results indicate that a series of electrochemical reactions take place during ECT. The cell metabolism and its environment are severely disturbed. Both normal and tumor cells are rapidly and completely destroyed in this altered environment. We believe that the above reactions are the ECT mechanisms for treating tumors.

Surgical treatment of nonunited fractures of the odontoid process, with special reference to occipitocervical fusion for unreducible atlantoaxial subluxation or instability

Fifty-seven consecutive patients treated surgically for nonunited fractures of the odontoid process were reviewed. All patients presented late, exhibiting neurological deficits subsequent to nonunion. Delay in presentation was between 6 and 120 months (mean 32 months) after the original injury, due to missed diagnosis or inappropriate management. Seven patients who were reduced in traction underwent a Gallie atlantoaxial fusion. In the remaining 50 patients who were unreducible, an occipitocervical arthrodesis was performed. They were followed up for a minimum of 2 years, except one who died from postoperative respiratory failure. All patients obtained a solid bony union, including two in whom nonunion occurred following atlantoaxial fusion, and occipitocervical fusion was added as a rescue. Thirty-eight patients achieved excellent neurological recovery, nine still had some disability, five retained their neurological deficits and two reported a deterioration. In two patients, a recurrence in a traumatic episode was experienced long after a resolution. Our findings demonstrate that occipitocervical arthrodesis is preferable for unreducible subluxation or instability of atlantoaxial articulation in nonunion of odontoid fractures.

Applications of simulator computed tomography number for photon dose calculations during radiotherapy treatment planning

PURPOSE

To study the variation of computed tomography (CT) number from a simulator-based scanner and the effect of this variation on photon-dose calculations.

METHOD AND MATERIALS

CT images of a cylindrical phantom with multiple inserts were obtained using a commercially-available simulator-CT (Ximatron: Varian, Palo Alto, CA). The linear correlation coefficient and Chi-square methods were used to determine the X-ray effective energy in a phantom. CT numbers in Hounsfield units (HU) were measured as a function of phantom size, orientation, field of view (FOV), distance from the center, and time for various inserts. The change of dose calculations due to the CT number variations was then determined using the equivalent path-length (EPL) and collapsed cone convolution methods.

RESULTS AND DISCUSSION

A significant beam-hardening effect was observed for the simulator-CT. Consequently, the CT number from the sim-CT was more sensitive to the size of the phantom than those from a conventional CT. The sim-CT number is not sensitive to the locations within the phantom and is stable over a 6-week period. It is important to use the proper FOV for sim-CT studies; scanning a small polystyrene phantom using a large FOV may result in an increase of l20 HU in CT number at the center of the field. However, the dose-calculation variations, due to the CT number uncertainty, do not exceed 2-3% for 6-18 MV photon beams.

CONCLUSION

The simulator CT images were acquired with patients in the treatment position, and these CT numbers are useful for CT-based dose calculations.

[Anterior corpectomy combined with cervical spine locking plate for treatment of multilevel cervical spondylotic myelopathy]

OBJECTIVE

To study the value of cervical spine locking plate (CSLP) combined with anterior corpectomy in treating multilevel cervical spondylotic myelopathy (CSM).

METHODS

In 55 CSM patients, 36 were male and 19 female, aged on average 51.5 years. The duration of illness was 13 months on average. Pathological segments in 47 patients included two functional segments and in 8 three functional segments. All patients were treated with anterior corpectomy and self-iliac bone graft and CSLP fixation.

RESULTS

51 patients were followed up for 26 months on average. All grafting bones got solid fusion in 12 to 16 weeks postoperatively. Intervertebral spaces were restored after operation. The physiological curve of the cervical spine was good. The effective rate of operation was 94.1% (48/51) and the excellent rate 78.4% (40/51). The JOA score rose from 8.3 points before operation to 14.1 points after operation.

CONCLUSIONS

Anterior corpectomy and osteosynthesis of multilevel cervical spondylotic myelopathy are indicated for CSLP fixation. CSLP in the treatment of cervical spine instability is prospective.

Os odontoideum: etiology, diagnosis, and management

BACKGROUND

There have been few reports of os odontoideum since the initial description.

METHODS

Forty-four patients with os odontoideum treated during the period 1980 through 1996 were reviewed. There were 33 males and 11 females. Their ages ranged from 7 to 56 years, with an average of 24.6 years. Five patients with no symptoms were treated conservatively. Thirty-nine patients underwent operative treatment including nine posterior atlantoaxial fusions and 33 occipitocervical fusions.

RESULTS

The patients were followed up for one to 16 years, with an average of 6.5 years. Five patients treated conservatively have remained stable. All 39 treated patients achieved solid arthrodesis. The results were satisfactory.

CONCLUSIONS

We conclude that fusion is indicated if atlantoaxial instability or clinical symptoms are significant, and that occipitocervical fusion should be considered in the operative management of os odontoideum if atlantoaxial arthrodesis is impossible.

Effects of unique ion chemistry on thin-film growth by plasma-surface interactions

Plasma processing is a standard industrial method for the modification of material surfaces and the deposition of thin films. Polyatomic ions and neutrals larger than a triatomic play a critical role in plasma-induced surface chemistry, especially in the deposition of polymeric films from fluorocarbon plasmas. In this paper, low energy CF3+ and C3F5+ ions are used to modify a polystyrene surface. Experimental and computational studies are combined to quantify the effect of the unique chemistry and structure of the incident ions on the result of ion-polymer collisions. C3F5+ ions are more effective at growing films than CF3+, both at similar energy/atom of approximately 6 eV/atom and similar total kinetic energies of 25 and 50 eV. The composition of the films grown experimentally also varies with both the structure and kinetic energy of the incident ion. Both C3F5+ and CF3+ should be thought of as covalently bound polyatomic precursors or fragments that can react and become incorporated within the polystyrene surface, rather than merely donating F atoms. The size and structure of the ions affect polymer film formation via differing chemical structure, reactivity, sticking probabilities, and energy transfer to the surface. The different reactivity of these two ions with the polymer surface supports the argument that larger species contribute to the deposition of polymeric films from fluorocarbon plasmas. These results indicate that complete understanding and accurate computer modeling of plasma-surface modification requires accurate measurement of the identities, number densities, and kinetic energies of higher mass ions and energetic neutrals.

Raloxifene and estradiol benzoate both fully restore hippocampal choline acetyltransferase activity in ovariectomized rats

Selective estrogen receptor modulators (SERMs) demonstrate tissue-specific estrogen receptor (ER) agonist or antagonist properties. Raloxifene, a prototypical SERM, has ER agonist properties in bone and on cholesterol metabolism but full antagonist properties in the uterus and breast. To characterize the ER agonist/antagonist profile of raloxifene in the brain, we have examined its effect on the activity of a known estrogen-responsive gene product, choline acetyltransferase (ChAT), in the hippocampus and other brain regions of 6-month-old ovariectomized (OVX) Sprague-Dawley rats. Three weeks post-ovariectomy, animals received estradiol benzoate (EB, 0.03 mg or 0.3 mg kg(-1) day(-1) for 3 or 10 days); raloxifene HCl (3.0 mg kg(-1) day(-1) for 3 or 10 days), tamoxifen (3.0 mg kg(-1) day(-1) for 10 days) or vehicle (20% CDX). As previously reported, ChAT activity decreased by approximately 20%-50% in the hippocampus of OVX compared with SHAM-operated control rats with no change in ChAT activity observed in the hypothalamus. Raloxifene or EB reversed the OVX-induced decrease in ChAT activity in the hippocampus but did not change ChAT activity in the hypothalamus. Animals that received combined EB (0.03 mg/kg) plus raloxifene (1 mg/kg) or tamoxifen alone (3.0 or 10 mg/kg) also showed increased hippocampal ChAT activity. Raloxifene failed to increase uterine weight and blocked the estrogen-induced increase in uterine weight, while another SERM, tamoxifen, increased uterine weight. These data demonstrate that raloxifene has estrogen-like properties on hippocampal ChAT activity in vivo, and suggest that benzothiophene SERMs may exert estrogen-like beneficial effects on cholinergic neurotransmission in brain without producing peripheral stimulation of breast or uterine tissue.

[Radiculopathy after cervical laminectomy]

OBJECTIVE

To investigate radiculopathy after multilevel laminectomy in patients with cervical compression myelopathy and underlying mechanism.

METHODS

We retrospectively reviewed 287 consecutive patients with cervical compression myelopathy treated by multilevel cervical laminectomy and identified 37 patients (12.9%) with postoperative radiculopathy. There were 27 men and 10 women, with an average age of 56 years at time of surgery. The diagnosis was either cervical spondylosis (25 patients) or ossification of the posterior longitudinal ligament (12 patients).

RESULTS

Radiculopathy was observed from 4 hours to 6 days after surgery. The most frequent patterns of paralysis were C(5) and C(6) root involvements of the motor-dominant type. All patients showed complete recovery in 2 weeks to 3 years (average, 5.4 months). Follow up results showed that the recovery rate was negatively related to the duration of complete recovery of postoperative radiculopathy (r = -0.832, P < 0.01) and the patients with spondylotic myelopathy had a significantly better clinical recovery rate than those with ossification of the posterior longitudinal ligament (t = 2.960, P < 0.01).

CONCLUSIONS

Postoperative radiculopathy is complicated with posterior cervical decompression and associated with tethering effect upon the nerve root. More logical procedures for prevention of postoperative radiculopathy are decompression through an anterior decompressive procedure in conjunction with a spinal fusion, which may achieve stabilization and directly remove all of the anterior spinal cord compression at multiple levels.

Regional distribution, ontogeny, purification, and characterization of the Ca2+-independent phospholipase A2 from rat brain

We purified an 80-kDa Ca2+-independent phospholipase A2 (iPLA2) from rat brain using octyl-Sepharose, ATP-agarose, and calmodulin-agarose column chromatography steps. This procedure gave a 30,000-fold purification and yielded 4 microg of a near-homogeneous iPLA2 with a specific activity of 4.3 micromol/min/mg. Peptide sequences of the rat brain iPLA2 display considerable homology to sequences of the iPLA2 from P388D1 macrophages, Chinese hamster ovary cells, and human B lymphocytes. Under optimal conditions, the iPLA2 revealed the following substrate preference toward the fatty acid chain in the sn-2 position of phosphatidylcholine: linoleoyl > palmitoyl > oleoyl > arachidonoyl. The rat brain iPLA2 also showed a head group preference for choline > or = ethanolamine >> inositol. The iPLA2 is inactivated when exposed to pure phospholipid vesicles. The only exception is vesicles composed of phosphatidylcholine and phosphatidylinositol 4,5-bisphosphate. Studies on the regional distribution and ontogeny of various phospholipase A2 (PLA2) types in rat brain indicate that the iPLA2 is the dominant PLA2 activity in the cytosolic fraction, whereas the group IIA secreted PLA2 is the dominant activity in the particulate fraction. The activities of these two enzymes change during postnatal development.

Study on air pollution in Beijing's major industrial areas using multielements in biomonitors and NAA techniques

Three kinds of plant leaves, Chinese white aspen, arborvitae, and pine needles, have been sampled from the Yanshan Oil refinery complex, the Capital Iron and Steel Factory, and Badachu, a control area in Beijing, as biomonitors for air-pollution studies. Each sample was divided into two parts, washed, and unwashed. Thirty-one trace elements (As, Au, Br, Ca, Cd, K, La, Lu, Mo, Na, Sb, Sm, U, W, Yb, Ba, Ce, Co, Cr, Cs, Eu, Fe, Hf, Hg, Rb, Sc, Se, Sr, Ta, Tb, Th, and Zn) have been determined by using the relative and the K0 methods of instrumental neutron activation analysis (NAA) techniques. The results indicated the following: (1) The concentration of trace elements in unwashed samples are much higher than these in washed samples; (2) the area around Capital Iron and Steel Factory is heavily polluted, and the Yanshan Oil refinery complex area is moderately polluted; (3) Chinese white aspen is a good biomonitor in particular seasons and pine needles are better than arborvitae for yearly monitoring; (4) elements As, Cd, Hg, Co, Rb, Sb, W, and Zn are highly absorbed by Chinese white aspen. Pine needles are sensitive for the absorption the elements Br, Cr, Cd, Fe, Sc, Cs and rare earth elements, but arborvitae is very sensitive for the absorption of Sr.

Preliminary study on the relationship between osteoporosis and trace elements with rat models

Thirty rats were divided randomly into five groups and fed with different feeds. They were killed after 2 mo. Right thighs of these rats were taken as samples. Bone mineral densities of these samples were measured by the double-energy x-ray bone mineral densitometer, and trace elements contents of the samples were analyzed by neutron activation analysis. Results of the experiments showed that some elements were well correlated with others, and there were obvious variances between some elements of the normal group and those of other four groups.

[Use of the primed in situ labeling technique for a rapid detection of chromosomes X, 18]

OBJECTIVE

To develop a rapid method for detection of chromosomes.

METHODS

Chromosomes X, 18 were detected by the primed in situ labeling(PRINS) in eight samples of female peripheral blood cultures.

RESULTS

Specific chromosomes were obtained on both metaphase and interphase nuclei. The efficiency of labeling was 84%-92%(mean=89%) in chromosome 18, and 73%-87%(mean=84%) in chromosome X. The pretreatment of slides by proteinase K markedly raised the efficiency of labeling and increased the intensity of signals. PRINS reaction could be performed automatically with a programmable thermocycler in less than one hour.

CONCLUSION

The results suggest that PRINS is a fast and specific method for identifying chromosomes. It may be a reliable technique for detecting aneuploid in prenatal diagnosis.

[Clinical significance of early diagnosis of cervical spondylotic myelopathy]

OBJECTIVE

To probe into the possibility of early diagnosis of cervical spondylotic myelopathy (CSM) prospectively and to screen the premorbid signs of CSM clinically, radiologically and electro-physiologically.

METHOD

Twenty-nine items related to the occurring of CSM were chosen as common characteristics of CSM and considered as the criteria of prospective study. 81 patients who met the criteria were studied. All patients were followed up and observed for 2 - 6.5 years (mean 3.7 years).

RESULT

Twenty-nine patients showed CSM during investigation. Thirteen items of the criteria were related to the occurring of CSM. The significant items include upper limb pain and abnormal sensation limb numbness, positive dynamic Hoffmann's sign, cervical canal stenosis, lower cervical instability, cervical intervertebral disc herniation, and delay of central motor conduct time.

CONCLUSION

CSM can be early diagnosed. The patients who meet the established criteria should be followed up and observed closely. Early operation results in good effect.

Investigation of senile dementia in Qingdao

According to the popular spot check method we investigated 14,684 partial community persons. The screen instrument used was the MMSE. Positive cases were through ADL, HDS and detailed psychical examination by two doctors according to the CCMD-2 to establish a definite diagnosis. Differential diagnosis between AD and MID was carried out according to HIS result. A total of 1448 persons were over 60 years, which amounted to 9.98% of the entire population. Of a total of 672 men and 776 females, 13 suffered senile dementia, which made up 0.995% of the aged. There were seven MID (5 males, 2 females) and six AD (2 males, 4 females). Family histories showed that one AD had the same symptoms as her twin sister. Two AD and four MD drank Chinese spirit 2-4 liang per day for 20 years, 80% of patients were nursed by the son or daughter-in-law, but they believed wrongly that 'It is necessary to cure the old'. Six of 13 had a long period of drinking history, four of six for MID. This has shown that dementia partly relates to drink especially for MID. Early case can be detected through daily life activities such as buying food, playing cards etc. Activities of daily living may avoid the pseudo-positive which is caused by educational level.

Radiculopathy after laminectomy for cervical compression myelopathy

Postoperative radiculopathy is a complication of posterior cervical decompression associated with tethering of the nerve root. We reviewed retrospectively 287 consecutive patients with cervical compression myelopathy who had been treated by multilevel cervical laminectomy and identified 37 (12.9%) with postoperative radiculopathy. There were 27 men and ten women with a mean age of 56 years at the time of operation. The diagnosis was either cervical spondylosis (25 patients) or ossification of the posterior longitudinal ligament (12 patients).

Radiculopathy was observed from four hours to six days after surgery. The most frequent pattern of paralysis was involvement of the C5 and C6 roots of the motor-dominant type. The mean time for recovery was 5.4 months (two weeks to three years). The results at follow-up showed that the rate of motor recovery was negatively related to the duration of complete recovery of postoperative radiculopathy (γ = −0.832, p < 0.01) and that patients with spondylotic myelopathy had a significantly better rate of clinical recovery than those with ossification of the posterior longitudinal ligament (t = 2.960, p < 0.01).

Postoperative radiculopathy may be prevented by carrying out an anterior decompression in conjunction with spinal fusion, which will achieve stabilisation and directly remove compression of the cord at multiple levels.

Radiculopathy after laminectomy for cervical compression myelopathy

Postoperative radiculopathy is a complication of posterior cervical decompression associated with tethering of the nerve root. We reviewed retrospectively 287 consecutive patients with cervical compression myelopathy who had been treated by multilevel cervical laminectomy and identified 37 (12.9%) with postoperative radiculopathy. There were 27 men and ten women with a mean age of 56 years at the time of operation. The diagnosis was either cervical spondylosis (25 patients) or ossification of the posterior longitudinal ligament (12 patients). Radiculopathy was observed from four hours to six days after surgery. The most frequent pattern of paralysis was involvement of the C5 and C6 roots of the motor-dominant type. The mean time for recovery was 5.4 months (two weeks to three years). The results at follow-up showed that the rate of motor recovery was negatively related to the duration of complete recovery of postoperative radiculopathy (gamma=-0.832, p < 0.01) and that patients with spondylotic myelopathy had a significantly better rate of clinical recovery than those with ossification of the posterior longitudinal ligament (t=2.960, p < 0.01). Postoperative radiculopathy may be prevented by carrying out an anterior decompression in conjunction with spinal fusion, which will achieve stabilisation and directly remove compression of the cord at multiple levels.

Selective deposition of amyloid-beta protein in the entorhinal-dentate projection of a transgenic mouse model of Alzheimer's disease

Early and selective deposition of amyloid beta protein(Abeta) is thought to be a pathological feature central to Alzheimer's disease (AD). It has been a great challenge to identify the mechanism(s) responsible for the selectivity of Abeta deposition and the deposition into a temporal sequence of the pathogenesis in this disorder. We now report that the transgenic mouse (PDAPP), which overexpresses the human amyloid precursor protein containing the familial AD mutation (APP717V-F), develops brain region-specific Abeta deposits along with some pathologies associated with AD. By using monoclonal antibodies that recognize multiple sites on the human Abeta peptide, we show that Abeta deposits are localized primarily to the entorhinal cortex and hippocampal/dentate gyrus regions. Abeta deposition exhibited consistent laminar distribution throughout the hippocampal formation that was confined mostly to a dense terminal field in the outer portion of the stratum moleculare of the dentate gyrus and the stratum lacunosum of the hippocampus proper of 13-month-old heterozygous PDAPP mice. Abeta deposits were also observed in the supragranular zone of the dentate gyrus. Similarly, laminar distribution of Abeta deposits were evident in the entorhinal cortex, most notably in the molecular layer and in laminar layer II-III. The defined laminar pattern of the Abeta deposition, which resembles that of AD, suggests that intrinsic factors in the perforant path, the major projection from the entorhinal cortex to the hippocampal formation, and their respective local paths contribute, at least in part, to the extracellular Abeta deposition in the transgenic mouse model of AD.

Inorganic Pi increases neuronal survival in the acute early phase following excitotoxic/oxidative insults

Inorganic phosphate (Pi) plays a vital role in intracellular energy metabolism. Its many effects include stimulation of glucose use, enhancement of high-energy phosphate concentrations, and modulation of cytosolic free [Ca2+]. Cultured fetal rat cortical neurons constitutively import Pi, and cytosolic levels positively correlate with [ATP], [NADPH], and energy charge. In the present study, we demonstrate that the concentration of intracellular Pi is an important determinant of acute neuronal survival after an excitotoxic or oxidative insult to cultured fetal rat cortical neurons. Extracellular Pi dose-dependently enhanced survival of cortical neurons after exposure to NMDA at early (< or = 6 h) time points after termination of the insult. Pi similarly increased neuronal survival after exposure to kainic acid or H2O2. Pi-exposed neurons had higher basal intracellular [Pi], [ATP], and [GSH], and slightly lower cytosolic free [Ca2+], compared with Pi-deprived neurons. Pi-exposed neurons maintained increased [ATP] after exposure to NMDA and displayed reduced formation of reactive oxygen species after exposure to kainic acid or H2O2, compared with Pi-deprived neurons. These findings demonstrate that changes in extracellular and intracellular Pi can affect neuronal survival after excitotoxic or oxidative insults.

[Cervical spondylotic myelopathy: early diagnosis and timing of operation]

OBJECTIVES

To study early clinical characteristics and diagnosis of cervical spondylotic myelopathy and to search the timing of surgery.

METHOD

Seventy-four cases of early diagnosed cervical spondylotic myelopathy (CSM) were treated with anterior cervical decompression and autologous ilium graft fusion.

RESULT

The early stage of CSM was indistinct, and symptoms were mild. Neck pain, abnormality of motion and sensation of limbs, and hand and arm symptoms were shown frequently. Changes in neurological function could found during physical examination. Characteristic changes in imaging were helpful in early diagnosis of the disease.

CONCLUSION

Early diagnosis and surgery of CSM are important in improving the therapeutic results.

Diagnosis and treatment of acute central cervical cord injury

OBJECTIVE

To clarify the diagnosis and management of acute central cervical cord injury.

METHODS

Eighty-nine patients with acute cervical central cord injury were retrospectively reviewed. Sixty-three patients were treated conservatively and 26 were treated surgically. There were two acute deaths. Eighty-seven patients were followed up for 3 months to 15 years.

RESULTS

Their average neurological score (ASIA) was increased from 41.7 at admission to 83.1 at follow-up.

CONCLUSIONS

Acute central cervical cord injury should be differentiated from complete spinal cord injury, cervical myelopathy, cruciate paralysis and C8 nerve root injury. When compression of nerve tissue or cervical instability is identified, operative intervention should be indicated. The prognosis is less optimistic in the patients with severe primary injury and at old age.