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.

[Research and application of far-infrared rays to drying Chinese medicinal herbs in small pieces]

OBJECTIVE

To introduce a far-infrared ray dryings device.

METHOD

The research background, work tenets, structure, function, technical parameters and tentative application of the device were reported. Chinese medicinal herbs in small pieces which contain volatile oils were dried by far-infrared rays and airing. The two drying methods were compared.

RESULT AND CONCLUSION

Not degrading the quality of medicinal herbs in small pieces, the device can be used to dry various kinds of medicinal herb pieces and thus deserves popularization.

Inhibitory effects of S-nitrosocaptopril on vasomotor tone

AIM

To study effects of captopril (Cap) and S-nitrosocaptopril (CapNO) on vascular tension.

METHODS

Tension of rabbit aortic rings and perfusion pressure of rat renal artery (PPr) were examined to evaluate the effects of CapNO.

RESULTS

CapNO (3 nmol.L-1-10 mumol.L-1) produced concentration-dependent vasorelaxation response in the rings of rabbit thoracic aortas. Endothelium denudation did not alter the relaxations to CapNO. In contrast, Cap had no vasorelaxing effect on the rings precontracted with phenylephrine. CapNO (10 nmol.L-1) decreased rat PPr in vivo (P < 0.01), and the effect was concentration-dependent and reversible. Cap showed a reduction in rat PPr only at the concentration 1000 nmol.L-1 (P < 0.05). The relaxing potency of CapNO was 100 times higher than that of Cap in this respect. Pre-perfusion of rat renal arteries with NG-monomethyl-L-arginine monoacetate (L-NMMA, 0.03 nmol.L-1) or L-arginine (3 nmol.L-1) did not significantly blocked the relaxing effect induced by CapNO.

CONCLUSION

CapNO had a direct vasodilatory effect.

The effects of S-nitrosocaptopril on renal filtration and blood pressure in rats

The present investigation was performed to evaluate the effects of S-nitrosocaptopril, a novel vasodilator possessing the capacities of both an angiotensin converting enzyme inhibitor and an NO donor, on blood pressure and renal function in rats. S-nitrosocaptopril produced acute reductions in mean arterial pressure after both oral dosing (5, 10, 50 mg/kg) to chronically-catheterized awake rats and intravenous administrations (0.125, 1.25, 12.5 mg/kg) to anesthetized rats. The hypotensive magnitude and duration of S-nitrosocaptopril were dose-dependent. Acute pressure-associated reductions in the glomerular filtration rate and urine flow were observed only at high concentration of S-nitrosocaptopril (12.5 mg/kg, i.v.) in both awake and anesthetized rats. These decreases were transient, followed by an overshoot of glomerular filtration rate and urine flow above basal values. In contrast, captopril (i.v.) did not produce any significant acute effects on mean blood pressure and glomerular filtration rate in either awake or anesthetized rats. In rats with acute hypertension induced by NG-monomethyl-L-arginine (L-NMMA, 30 mg/kg, i.v.), S-nitrosocaptopril (0.125 mg/kg, i.v.) significantly abolished the hypertensive effects. In contrast, the hypertension was not affected by captopril. In two-kidney one-clipped Goldblatt hypertensive rats, oral administration of S-nitrosocaptopril (25 mg/kg, b.i.d.) for 10 days significantly reduced systolic blood pressure and preserved glomerular filtration rate. The oral antihypertensive effect of S-nitrosocaptopril was more potent than captopril (P < 0.05). In conclusion, these findings indicate that: (1) S-nitrosocaptopril provides both acute and chronic anti-hypertensive effects orally and intravenously, whereas captopril has only moderate chronic oral effects; and (2) S-nitrosocaptopril preferentially decreases blood pressure without markedly affecting glomerular filtration rate.

Color correction of the video image obtained by angioscope

In this article, a simple color correction method for the color reproduction of image obtained by angioscope is reported. We present the method to obtain the matrices theoretically and experimentally, respectively. For the angioscope system, we suggest two matrices: an average color correction matrix A and a blood vessel color correction matrix A'. Using the two matrices, the images of several color samples captured by an angioscope are processed, and their reproduced colors are evaluated. With this method, the discrimination ability of the angioscope will be improved dramatically. © 1998 Society of Photo-Optical Instrumentation Engineers.

[The effects of graded spinal cord injuries on transcranial electric stimulation motor evoked potentials in the rat]

OBJECTIVE

To study the effects of graded spinal cord injury (SCI) on the motor evoked potentials (MEP) characteristics and the prognostic value of MEP for the motor function.

METHOD

Modified Allen's method was used by weight drop force of 30 gcf, 50 gcf, 80 gcf and 100 gcf on the T(8 - 9) spinal cord of 40 SD rats in order to make SCI models. MEP was recorded continuously at L(1 - 2) epidurally and bilateral gastrocnemius muscles before and after the spinal cord lesion was produced (followed up for 1 month). The inclined plane and Tarlov technique were used to assess clinical neurological function.

RESULT

The amplitude of rat's MEP changed significantly with graded SCI, the more sever the lesion, the lower the potentials. mMEP was more sensitive than scMEP, though the abolishment of mMEP soon after SCI didn't indicate that the animals could not regain ambulation. Changes in amplitude of scMEP recorded early after SCI were collaborate significantly with inclined plane (gamma = 0.9665, P < 0.01) and Tarlov scale (gamma = 0.8893, P < 0.01) assessed 1 month later, and can be used as a chronic measure parameter of motor function prognosis. scMEP still existed 1 month after SCI in 3 of 11 rats (27.3%) without any voluntary movement in bilateral hindlimbs, suggesting that some parts of conductive function still existed in the spinal cord. So it should be called "discomplete SCI".

CONCLUSIONS

scMEP can be used as a reliable parameter for motor function prognosis, because it reflects objectively and sensitively the severity of central motor neurol fiber injury.

[Determination of HIgG in Human plasma by high performance membrane affinity chromatography(HPMAC)]

An assay technique for determination of Human IgG in human plasma has been developed by utilizing Protein A bound to the modified cellulose matrices based on the strong affinity between protein A and Fc region of IgG. The pH values of loading buffer and elution buffer were 7.0 and 2.3 respectively. The cartridge used was 20 mm x 4 mm i.d. and detection was carried out with a UV monitor at 280 nm. The non-specific adsorption of two kinds of media has been studied. The media without hexyldiamine arm gives very low non-specific adsorption BSA. The calibration curve showed a good linearity (correlation coefficient > 0.9992) in the injected amount range of 9-70 micrograms for HIgG. The total time for separation and determination was within 5 min and the total time of rapid assay was within 30 s. Relative standard deviations of peak areas were 1.5% (n = 5) and 3.6% (n = 3) for HIgG in standard solution and human plasma respectively.

[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.

Promoter recognition by a cyanobacterial RNA polymerase: in vitro studies with the Calothrix sp. PCC 7601 transcriptional factors RcaA and RcaD

To study the transcriptional apparatus and the mechanisms that control gene expression in cyanobacteria, the RNA polymerase was purified from the filamentous Calothrix sp. PCC 7601 and used in in vitro transcription assays. Conditions required for specific transcription initiation to occur were analyzed with the eleven Calothrix PCC 7601 genes for which the 5' ends have been mapped. Most of the transcripts directly obtained did not have the expected size, providing a test for looking at specific transcription factors. Addition of RcaA, a protein that binds to the promoter region of the phycobiliprotein cpeBA operon, restored accurate initiation of transcription in the in vitro system for three phycobiliprotein promoters. RcaA thus is a transcription factor that allows to mimick in vivo transcription. In parallel, the functional properties of the Escherichia coli and cyanobacterial RNA polymerases were compared. The enteric enzyme could not precisely initiate transcription at the promoter of a phycobiliprotein gene and, reciprocally, the cyanobacterial RNA polymerase could initiate transcription at PlacUV5, but not from wild-type Plac promoters. The different behaviours of the enzymes are discussed in the light of the structural differences that exist between subunits of the RNA polymerases.

[Observation of Qingyu Jiuxin pills in treatment of silent myocardial ischemia in senile patients with coronary heart disease]

OBJECTIVE

To assess the effect of Qingyu Jiuxi Pills (QYJXP) in the treatment of silent myocardial ischemia (SMI) in elder patients with coronary heart disease.

METHODS

Randomized crossing self-controlled observation method was adopted. Fifty-eight patients were treated with QYJXP in treated period and isosorbide dinitrate (ISD) in control period.

RESULTS

Frequency and sustained time of SMI could be significantly reduced (P < 0.01) after the treatment of both QYJXP and ISD. The efficacy of QYJXP was better (P < 0.05) than that of ISD. No side effects were found in treating with QYJXP.

CONCLUSION

QYJXP is an effective and safe drug in treating SMI.

Solitary bone cyst in the odontoid process and body of the axis. A case report and review of literature

A four-year-old boy presented with a solitary bone cyst in the odontoid process and body of the axis. Plain radiographs showed a radiolucent lesion with extreme thinning of the cortex and MRI demonstrated a high signal intensity in the interlesional matrix. The cystic component extended into the body of the axis through a defect in the epiphyseal plate. At operation, the cavity of the cyst was found to contain serosanguineous fluid, and histological examination showed that it was lined by a thin layer of connective tissue. The cyst may have originated from a defect in the epiphyseal plate.

Solitary bone cyst in the odontoid process and body of the axis

A four-year-old boy presented with a solitary bone cyst in the odontoid process and body of the axis. Plain radiographs showed a radiolucent lesion with extreme thinning of the cortex and MRI demonstrated a high signal intensity in the interlesional matrix. The cystic component extended into the body of the axis through a defect in the epiphyseal plate.

At operation, the cavity of the cyst was found to contain serosanguineous fluid, and histological examination showed that it was lined by a thin layer of connective tissue. The cyst may have originated from a defect in the epiphyseal plate.

Acute central cervical cord injury presenting with only upper extremity involvement

Twenty-four patients with acute central cervical cord injury with motor and sensory impairment involving only the upper extremities are described; none had any abnormality in the lower extremities. They were all treated conservatively with one exception in whom an anterior decompression was performed. Seventeen had complete recovery of motor function; the remaining 7 had some weakness of the palmar interosseous muscles. The time to recovery was from 2 weeks to 4 months. Sensory recovery took from 4 to 6 months after injury. This type of injury is caused by damage to the anterior and posterior horn cells in the cervical cord.

[Localization of central rhythm generator for tongue movements in sucking--analysis of isolated brainstem-spinal cord preparation from newborn rats]

Localization of the central rhythm generator (CRG) for tongue movements in sucking was studied in in vitro brainstem-spinal cord preparations from newborn rats, using the rhythmical sucking-like activity (RSA) of the hypoglossal nerve (XII) induced by perfusion of N-methyl-D-aspartate (NMDA) as the index of sucking. Sulforhodamine 101 (S 101), a fluorescent dye taken up by neurons in an activity dependent manner, was applied to the preparations which showed only spontaneous inspiratory activity in XII without NMDA application and to those which showed NMDA-induced RSA in XII. In both preparations, the neurons labelled with S 101 were found in the hypoglossal nucleus, facial nucleus, ambiguous nucleus, solitary tract nucleus, trigeminal spinal nucleus, inferior olivary nucleus, gigantocellular, lateral and ventral reticular nuclei. More neurons were labelled more intensely in the latter preparations. The difference was particularly conspicuous in the gigantocellular reticular nucleus, suggesting that it plays an especially important role in central rhythm generation of sucking. The NMDA-induced RSA in XII persisted after removal of the dorsal medulla oblongata, the caudal pons constituting a part of the CRG for mastication, and the trigeminal spinal nucleus relaying afferents in sucking reflex. It was concluded that the CRG for tongue movements in sucking is localized in the ventromedial medulla oblongata.

Mitochondrial ultracondensation, but not swelling, is involved in TNF alpha-induced apoptosis in human T-lymphoblastic leukaemic cells

Mitochondrial permeability transition (PT) pore opening and mitochondrial swelling have been reported in association with apoptosis. Conformational alterations of mitochondria induced by tumour necrosis factor-alpha (TNF alpha), and the association with TNF alpha-induced apoptosis, were, therefore, studied in the human acute T-lymphoblastic leukaemia (T-ALL) cell line, CCRF-CEM and its vinblastine-resistant CEM/VLB100 cell line by transmission electron microscopy (TEM). The CEM/VLB100 cell line possessed more condensed (C phase) mitochondria in the resting state compared with its parental cell line, consistent with increased activity of the mitochondrial electron transport chain (ETC). Following exposure to TNF alpha, conformational alterations of mitochondria occurred in both apoptotic and non-apoptotic cells. Orthodox (O phase) mitochondria in non-apoptotic cells underwent C-phase, transitional O-phase and slightly swollen (S-phase) conformational changes. TNF alpha-induced mitochondrial swelling was a late event and was found to a far lesser extent than mitochondrial condensation. No swollen mitochondria were observed in apoptotic cells. Ultracondensed (UC phase) mitochondria were observed in cells undergoing both TNF alpha-induced and spontaneous apoptosis and were seen when TNF alpha-induced apoptosis was inhibited by 3-methyladenine (3MA). The structural integrity of UC phase mitochondria persisted through the apoptotic process. We conclude that TNF alpha-induced mitochondrial swelling and apoptosis are separate events. Mitochondrial ultracondensation is associated with the processes signalling apoptosis and is not a result of TNF alpha-induced apoptotic shrinkage.

Inhibition of autophagy abrogates tumour necrosis factor alpha induced apoptosis in human T-lymphoblastic leukaemic cells

The pattern and the sequence of tumour necrosis factor-alpha (TNF alpha) induced cell death in the acute T-lymphoblastic leukaemic cell line CCRF-CEM and its vinblastine-resistant subline CEM/VLB100 have been studied. Previously, we found that the CEM/VLB100 cell line was more sensitive to TNF alpha-induced killing than its parental CCRF-CEM cell line. TNF alpha-induced cell death showed an apoptotic pattern, as detected by agarose electrophoresis, flow cytometry and transmission electron microscopy (TEM). TEM images revealed that autophagy and codensed mitochondria occurred earlier than nuclear fragmentation. The specific inhibitor of autophagy, 3-methyladenine (3MA), inhibited the formation of autophagosomes. TNF alpha-induced DNA fragmentation and cytolysis were completely inhibited by 10 mM 3MA. Inhibition of the fusion of lysosomes with autophagosomes by asparagine did not block TNF alpha-induced apoptosis. In addition, amino acid and protein deprivation enhanced TNF alpha-induced autophagy but not apoptosis. We propose that the early stages of autophagy are required for, but do not necessarily result in, TNF alpha-induced apoptosis.

Mitochondrial electron transport chain activity, but not ATP synthesis, is required for drug-induced apoptosis in human leukaemic cells: a possible novel mechanism of regulating drug resistance

There is increasing evidence for an association between mitochondrial function and susceptibility to apoptosis. It has been shown that the vinblastine-resistant leukaemic cell line CEM/VLB100 has a more active mitochondrial electron transport chain (ETC) than the parental CCRF-CEM cell line. Inhibition of mitochondrial DNA replication by ethidium bromide (EB) depleted the activity of the ETC and reduced cellular respiratory rate. Depletion of mitochondrial DNA was associated with increased resistance to vinblastine-induced apoptosis in both cell lines. In contrast, the highly specific inhibitor of the energy producing mitochondrial enzyme F1Fzero-ATPase, oligomycin, rendered CEM/VLB100 cells more sensitive to vinblastine by inhibiting the energy-dependent P-glycoprotein (Pgp) pump, suggesting that the effect of EB is independent of energy generation and ATPase activity. Both mitochondrial ETC depletion and ATPase inhibition decreased vinblastine-induced cell cycle changes in the CCRF-CEM cell line, suggesting that cell cycle changes are dependent on ATP generation. However, EB-induced ETC depletion in CEM/VLB100 cells inhibited apoptosis in response to high concentration of vinblastine, but not G2M arrest. We suggest that: (1) over-expression of Pgp by drug-resistant cells may up-regulate mitochondrial energy production; (2) mitochondrial ETC activity is required for DNA fragmentation in response to vinblastine, but the mechanism is independent of Pgp activity and ATP generation; (3) down-regulation of mitochondrial ETC activity may confer resistance to vinblastine-induced apoptosis; (4) the mitochondrial ETC is involved in vinblastine-induced apoptosis downstream of microtubule disruption and cell cycle changes.

Immobilized IDA-type Cu2+-chelating membrane affinity chromatography for purification of bovine liver catalase

Cu2+-chelating membrane medium based on iminodiacetate-substituted modified short cotton cellulose was examined to purify bovine liver catalase (BLC) by affinity chromatography. The buffer pH notably affect BLC binding to the Cu2+-chelating membrane adsorbent. The results showed that under the chromatographic conditions chosen, 67.7% recovery of BLC attained with an overall 4.7-fold increase in specific activity in a single step. After purification of BLC, the chelating membrane adsorbent can easily be regenerated by imidazole or EDTA buffer. Different results were obtained by the two regeneration methods: the later is more effective than the former in reviving the purification characters of the chelating membrane adsorbent.

Blood flow regulation by S-nitrosohemoglobin in the physiological oxygen gradient

The binding of oxygen to heme irons in hemoglobin promotes the binding of nitric oxide (NO) to cysteinebeta93, forming S-nitrosohemoglobin. Deoxygenation is accompanied by an allosteric transition in S-nitrosohemoglobin [from the R (oxygenated) to the T (deoxygenated) structure] that releases the NO group. S-nitrosohemoglobin contracts blood vessels and decreases cerebral perfusion in the R structure and relaxes vessels to improve blood flow in the T structure. By thus sensing the physiological oxygen gradient in tissues, hemoglobin exploits conformation-associated changes in the position of cysteinebeta93 SNO to bring local blood flow into line with oxygen requirements.

[Clinical study of the relationship between the lateral recesses and the nerve roots]

To explicate the relationship and the clinical signification between the normal or narrow lateral recesses and the nerve roots, we measured the diameter of the entrans zone of the lateral recess, the interval between the upper articular processes and the interval between the nerve root and ab line on 50 normal cases, 43 narrow cases and 32 stenosis cases with VIDS image analysis system. The results showed that the nerve root was in the center side of the ab line in the normal station, with the degrees of the degeneration and cohesion ncreasing, the nerve root was in the lateral recess side of the ab line, and was compressed by the lateral recess. The authors considered that the real clinical signification of the entrance zone of the lateral recess was danger to the nerve root, but the deciding factors were the degrees of the degeneration and cohesion of the upper articular processes. The pathological conditions that resulted in the stenosis of the lateral recess and dangered the nerve root such as disc, flavum ligament and posterior port of the fibra ring were discussed in the article.

[Determination of calcium in brains of rat by ICP-AES]

This paper reports the determination of calcium in brains of rat by ICP-AES. The recovery rate is 97%, the RSD is 1.16%, and the results are satisfactory. The interference effects of phosphor on the calcium under various operating conditions in ICP-AES were studied.

[Os odontoideum]

Seventeen patients who had os odontoideum were reviewed. Among them occipito-cervical fusion was performed upon 12 patients with atlanto-axial instability. All of them achieved fusion. The patients were followed up for 2 to 16 years and satisfactory results were demonstrated. We consider that surgical treatment is indicated when os odontoideum is combined with atlanto-axial instability.

Role of facet asymmetry in lumbar spine disorders

The correlation between facet joint asymmetry and disorders of the lumbar spine was analyzed in a study of plain radiographs, computed tomograms and magnetic resonance images from 76 normal subjects and 173 patients who underwent lumbar surgery. Of 76 normal controls who were studied by means of plain radiographs, only 21 (27.6%) had facet asymmetry at the level of L4-5 or L5-S1, while 84 (48.6%) of 173 patients who were studied with plain radiographs, and partially with CT or MRI, were noted to have facet asymmetry. The difference was highly significant (P < 0.01). This study supports the etiologic significance of facet asymmetry in lumbar disorders.

Polynitrosylated proteins: characterization, bioactivity, and functional consequences

Chemical modification of proteins is a common theme in their regulation. Nitrosylation of protein sulfhydryl groups has been shown to confer nitric oxide (NO)-like biological activities and to regulate protein functions. Several other nucleophilic side chains -- including those with hydroxyls, amines, and aromatic carbons -- are also potentially susceptible to nitrosative attack. Therefore, we examined the reactivity and functional consequences of nitros(yl)ation at a variety of nucleophilic centers in biological molecules. Chemical analysis and spectroscopic studies show that nitrosation reactions are sustained at sulfur, oxygen, nitrogen, and aromatic carbon centers, with thiols being the most reactive functionality. The exemplary protein, BSA, in the presence of a 1-, 20-, 100-, or 200-fold excess of nitrosating equivalents removes 0.6 +/- 0.2, 3.2 +/- 0.4, 18 +/- 4, and 38 +/- 10, respectively, moles of NO equivalents per mole of BSA from the reaction medium; spectroscopic evidence shows the proportionate formation of a polynitrosylated protein. Analogous reaction of tissue-type plasminogen activator yields comparable NO protein stoichiometries. Disruption of protein tertiary structure by reduction results in the preferential nitrosylation of up to 20 thus-exposed thiol groups. The polynitrosylated proteins exhibit antiplatelet and vasodilator activity that increases with the degree of nitrosation, but S-nitroso derivatives show the greatest NO-related bioactivity. Studies on enzymatic activity of tissue-type plasminogen activator show that polynitrosylation may lead to attenuated function. Moreover, the reactivity of tyrosine residues in proteins raises the possibility that NO could disrupt processes regulated by phosphorylation. Polynitrosylated proteins were found in reaction mixtures containing interferon-gamma/lipopolysaccharide-stimulated macrophages and in tracheal secretions of subjects treated with NO gas, thus suggesting their physiological relevance. In conclusion, multiple sites on proteins are susceptible to attack by nitrogen oxides. Thiol groups are preferentially modified, supporting the notion that S-nitrosylation can serve to regulate protein function. Nitrosation reactions sustained at additional nucleophilic centers may have (patho)physiological significance and suggest a facile route by which abundant NO bioactivity can be delivered to a biological system, with specificity dictated by protein substrate.

S-nitrosohaemoglobin: a dynamic activity of blood involved in vascular control

A dynamic cycle exists in which haemoglobin is S-nitrosylated in the lung when red blood cells are oxygenated, and the NO group is released during arterial-venous transit. The vasoactivity of S-nitrosohaemoglobin is promoted by the erythrocytic export of S-nitrosothiols. These findings highlight newly discovered allosteric and electronic properties of haemoglobin that appear to be involved in the control of blood pressure and which may facilitate efficient delivery of oxygen to tissues. The role of S-nitrosohaemoglobin in the transduction of NO-related activities may have therapeutic applications.

Increased activity and sensitivity of mitochondrial respiratory enzymes to tumor necrosis factor alpha-mediated inhibition is associated with increased cytotoxicity in drug-resistant leukemic cell lines

The drug-resistant leukemic cell lines, CEM/VLB100 and K/DAU600, are more sensitive to tumor necrosis factor alpha (TNFalpha)-mediated cytotoxicity compared with their parental cell lines, CCRF-CEM and K562 cl.6. Drug-resistant leukemic cell lines have more active mitochondrial function, which is associated with a greater susceptibility to TNFalpha-induced respiratory inhibition. TNFalpha blocked electron transfer at three sites, NADH dehydrogenase (complex I), succinate dehydrogenase (complex II), and cytochrome c oxidase (complex IV). Respiratory rate and electron transport chain enzyme activities were significantly inhibited in the drug-resistant, TNF-sensitive cell lines. Respiratory inhibition preceded cell death by at least 5 to 8 hours. The respiratory failure was not compensated for by appropriate up-regulation of the glycolytic pathway. Increasing mitochondrial respiratory rate and enzyme activities by long-term culture with 2 mmol/L adenosine 5'-diphosphate (ADP) and Pi sensitized both drug-sensitive and drug-resistant cells to TNFalpha-induced cytolysis. Intramitochondrial free radicals generated by paraquat only had a limited and delayed effect on respiratory inhibition and cytolysis in comparison with the effect of TNFalpha. We conclude that TNFalpha-induced cytotoxicity in leukemic cells is, at least in part, mediated by inhibition of mitochondrial respiration. Free radical generation by TNFalpha may not directly lead to the observed inhibition of the mitochondrial electron transport and other mechanisms must be involved.

[Effect of platelet activating factor receptor at spinal cord neurocyte membrane on secondary damage after spinal cord injury]

OBJECTIVE

To investigate the effects of platelet activating factor (PAF) receptor and its antagonist on secondary damage after spinal cord injury.

METHODS

We extracted spinal cord neurocyte membrane protein in cats by improved Domigo method. The specific binding sites of PAF were measured by 3H-PAF radioligand binding test.

RESULTS

There were both high affinity binding sites and low affinity binding sites of PAF on spinal cord neurocyte membrane. The Kd1, Bmax1, Kd2 and Bmax2 of PAF receptor on spinal cord neurocyte membrane at 2, 6 hours and 1 week after trauma significantly decreased as compared to sham-operated control group (P < 0.01). PAF receptor antagonist BN52021 could reduced water content and Even's blue content of injured spinal cord tissue, also improve pathological change of spinal cord tissue after trauma.

CONCLUSIONS

PAF receptor plays an important role in inducing pathophysiological process of secondary damage after trauma. PAF receptor antagonist can effectively prevent and treat secondary damage after trauma.

Modulation of surface TNF expression by human leukaemic cells alters their sensitivity to exogenous TNF

In this study, U937 leukaemic cells underwent apoptotic cell death following exposure to TNF. Pre-incubation of cells for 48 h with VitD(3) (10(-8)M) induced resistance to TNF, whereas incubation with tau-IFN or GM-CSF increased susceptibility to TNF. Resistance to exogenous TNF (exTNF) following culture with VitD(3) was associated with increased expression of endogenous TNF (enTNF). The TNF inhibitors pentoxifylline(PTF) and dichloroisocoumarin (DCI) inhibited TNF synthesis by U937 cells and abrogated the increase in resistance to TNF seen with VitD(3). The tau-IFN increased TNF expression, whereas GM-CSF had little effect. The data show that the sensitivity of leukaemic cells to exTNF can be modulated by cytokines. The protective effect of VitD(3) is mediated in part by directly upregulating enTNF synthesis.

[Image and clinical correlative studies on cervical spinal canal stenosis]

Clinical finding, X-ray and MR imagings in 47 patients who underwent operation for degenerative cervical stenosis were correalatively studied. JOA score was used for evaluation and it varied from 6 to 14 points, with an average of 10.13 points. All Torg ratios were smaller than normal value and that of C4 was the smallest. The reserve space, sagittal diameter of spinal cord decreased, especially in the diseased segments. Sagittal diameter of spinal cord showed on T2 weighted imaging and Torg ratio were in good correlation with JOA score (P < 0.01, r = 0.4815, r = 0.0993), MRI being superior to X-ray (P < 0.01). The MRI characteristic changes of degenerative cervical stenosis were subarachnoid space decrease or vanish, compression deformation of spinal cord and abnormal signal in spinal cord. MRI classification was established according to the segments involved, compression direction. compression degree and abnormal changes in spinal cord, can indicate clinical changes and guide diagnosis and operation.

Cruciate paralysis caused by injury of the upper cervical spine

Cruciate paralysis is an uncommon injury to the cervicomedullary junction. Five patients with injuries of the upper cervical spine and the clinical manifestation of cruciate paralysis are presented. This injury pattern is characterized by bilateral upper extremity paralysis, with minimal or no lower extremity involvement. The neuroanatomic basis and the diagnosis of this clinical entity are discussed, and the related reports in the literature are reviewed.

NMDA-induced rhythmical activity in XII nerve of isolated CNS from newborn rats

We tried to induce rhythmical oro-facial motor activities in an isolated brain stem-spinal cord preparation from newborn rats. Neural activities were monitored from the hypoglossal nerve (XII N) and the ventral roots of the cervical cord. Bath application of N-methyl-D-aspartate (NMDA) as well as glutamate induced rhythmical burst activity in XII N distinct from and much faster than respiratory rhythm. This NMDA-induced rhythmical activity was blocked by simultaneous application of 2-amino-5-phosphonovalerate (AP5). The results demonstrate that NMDA receptor activation can induce rhythmical XII N activity different from respiration in an isolated mammalian CNS. This preparation will be useful for the investigation of neural mechanisms underlying the central generation of food ingestive movements.

[The effect of qing guang kang on the metabolism of retinal ganglionic cells in rats after artificial acute high intraocular pressure]

A modified cytochrome oxidase (CO) histochemical and computer image techniques were used to examine the effect of Qing Guang Kang (QGK) injection on the metabolism of rat retinas after artificial acute high intraocular pressure. The results show that 75% of the average arterial blood pressure as the perfusing pressure of the anterior chamber of rats can lead to the decrease of numbers of CO active retinal ganglionic cells and their grey values. QGK possess the protective and/or improving effects on the CO active retinal ganglionic cells of rat under artificial acute high intraocular pressure. In the study, the data of density and the grey value of CO active ganglionic cells in the experimental models with QGK injection are significantly different from those of the control group (P < 0.05).

TNF-mediated killing of human leukaemic cells: effects of endogenous antioxidant levels and TNF alpha expression in leukaemic cell lines

Using the human erythroleukaemic cell line K562 cl.6 and its daunorubicin-resistant subline K/DAU600, and the human T-lymphoblastic leukaemic cell line CCRF-CEM and its vinblastine-resistant subline CEM/VLB100, we have shown that the drug-resistant cell lines were more sensitive to cytotoxicity induced by tumour necrosis factor-alpha (TNF alpha). Drug-resistant cell lines showed increased activities of copper/zinc superoxide dismutase (Cu/ZnSOD) and catalase compared with their parental drug-sensitive cell lines. However, the greater susceptibility of drug-resistant cells to TNF alpha cytotoxicity was, in part, related to their decreased activities of manganese superoxide dismutase (MnSOD). Persistence of this differential sensitivity when MnSOD is inhibited by sodium nitroprusside (SNP) suggests that the greater susceptibility of drug-resistant cells to TNF alpha was not entirely due to their decreased level of MnSOD activity. K562 cl.6 and K/DAU600, which were more resistant to TNF alpha, both expressed greater levels of endogenous plasma membrane-bound TNF alpha than the CCRF-CEM cell line. All cell lines examined were (more or less) equal in susceptibility to the cytolytic effect of exogenous O2-. generated by xanthine/xanthine oxidase. These results demonstrate that both MnSOD and endogenous TNF alpha play a role in protecting leukaemic cells against TNF alpha cytotoxicity, but there is an unknown mechanism that causes drug-resistant cells to be more susceptible to TNF alpha cytotoxicity.

Tumor metastasis to brain: role of endothelial cells, neurotrophins, and paracrine growth factors

An important clinical endpoint in patients with cancer is formation of metastases in the brain. Understanding this phenomenon is important in several types of malignancies, including melanoma, lung and breast cancers. Metastatic tumor cells use specific adhesion molecules to home to brain, and there they must attach to microvessel endothelial cells and respond to brain endothelial cell-derived motility factors and brain invasion factors to invade the CNS. Neurotrophins are important invasion factors in this process, and the ability to invade into the brain may well depend on metastatic cell responses to neurotrophins and production of basement membrane-degradative enzymes capable of locally destroying the blood-brain barrier. Brain-metastatic human melanoma cells express low-affinity p75 receptor for neurotrophins such as nerve growth factor, but they do not express the high-affinity-type receptors for nerve growth factor encoded by the protooncogene trkA. Tumor cells can proliferate in the CNS in response to local paracrine growth factors and inhibitors, but their growth also depends on their producing and responding to autocrine growth factors. A major organ-derived (paracrine) growth factor has been isolated that differentially stimulates the growth of cells metastatic to the brain. Characterization of this mitogen demonstrated that it is a transferrin-like glycoprotein; cells that are metastatic to brain express greater numbers of transferrin receptors on their surfaces than cells that are poorly metastatic or metastatic to other sites. Transferrin-like factors are expressed in fetal brain and could represent the transferrin-like factors that stimulate growth of brain-metastatic melanoma and breast cancer cells. These and other factors are probably important in determining whether metastatic cells can successfully invade, colonize, and grow in the CNS.