Biomedical subjects

L Jia

Publications and source records attributed to L Jia.

At least 91 records · Page 5Linked to original sources

PubMed1998

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.

Adult↗

PubMed1998

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.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed1998

Fast assay and mini-purification of protein by high performance membrane affinity chromatography.

Several affinity ligands of protein A, human immunoglobulin G, iminodiacetate (IDA)-Cu2+, and cibacron blue F3GA were coupled to GMA-modified cellulose membrane matrices. We prepared the columns based on the membrane supports in high performance membrane affinity chromatography (HPMAC). Next we evaluated nonspecific adsorption of proteins on the membrane media. The rapid assay of proteins on the affinity columns based on membrane supports was achieved. It was observed that the affinity columns based on membrane supports provided good reproducibility, high separation efficiency, and low pressure drop of the column. The columns with the membrane media could also be used for purification of proteins.

Adsorption↗

PubMed1998

[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.

Chromatography, Affinity↗

PubMed1998

[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.

Aged↗

PubMed1998

[Application of capillary electrophoresis in speciation analysis].

Each species has different chemical and biological behaviors. Toxicity is often dependent on it. So element speciation is important in a variety of environmental, biological, geological, and medical applications. Recently, capillary electrophoresis(CE) has been applied to speciation analysis owing to its high efficiency and short analysis time. This paper reviews the applications of CE-UV and CE-ICP-MS in speciation analysis and discusses some related problems.

Arsenic↗

PubMed1998

[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.

Infrared Rays↗

PubMed1998

[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.

Adult↗

PubMed1998

[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.

Animals↗

PubMed1998

[Diagnosis and treatment of tethered cord syndrome in adults].

OBJECTIVE: To study the clinical characteristics of tethered cord syndrome (TCS) in adults. METHOD: 18 patients with TCS were confirmed by preoperative MRI and were operated on for releasing of tethered conus. Pathological mechanism and main points of operation were analysed according to the operative findings and radiological data. RESULT: The cord or conus were tethered by intradural tumors (6 patients), myelomeningocele (6), thickened filum terminale (3), diastematomyelia (2) and adhesion after operation (1). 14 of the 18 patients showed good results after follow-up for 8 months to 5 years. CONCLUSION: Clinical manifestation and prognosis of TCS in adults are different from those of TCS in children. Attention should be paid to avoid additional injury to the conus and cauda equina during operation. The long course of disease and retethering of the conus lead to poor outcome.

Adolescent↗

PubMed1998

[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.

Adult↗

PubMed1998

[The property of protein A affinity membrane cartridge and purification of IgG from human plasma].

A new protein A affinity membrane based on composite matrix formed by covalent cross-linking of the glycidyl methylacrylate to softwood cellulose fiber was developed. The study focused on the physical properties and adsorption capacity of the affinity membrane cartridge. The results showed that the relationship between flow-rate and backpressure was linear. When flow-rate was 3 mL/min, backpressure attained 160 kPa. The effects of IgG mass concentration and sampling flow-rate on the binding capacity by protein A cartridge were studied for the optimum purification of IgG. A 21.7 mg/g dry matrix of maximum dynamic binding capacity for IgG was obtained by dynamic adsorption. The cartridge was loaded with human plasma to test its ability to fractionate IgG. The IgG purified from human plasma was analysed by capillary zone electrophoresis (CZE). The results showed that the protein A affinity membrane cartridge had high selectivity for IgG from human plasma. The purity of IgG from human plasma purified by the immobilized protein A membrane cartridge was over 98%. The fast-flow property of the membrane cartridge made from such a matrix and its simplicity in operation provide effective means for purifying immunoglobulins on a relatively large scale.

Chromatography, Affinity↗

PubMed1997

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.

Animals↗

PubMed1997

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.

Accidental Falls↗

PubMed1997

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.

Adenine↗

PubMed1997

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.

Apoptosis↗

PubMed1997

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.

Adenosine Triphosphatases↗

PubMed1997

[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.

Adult↗