Biomedical subjects

James D Kang

Publications and source records attributed to James D Kang.

30 records · Page 2Linked to original sources

PubMed2003

Anterior cervical approaches for cervical radiculopathy and myelopathy.

Compression of the spinal cord and nerve roots caused by spondylotic changes or disk herniations is the most common etiology for cervical myelopathy, radiculopathy, or myeloradiculopathy. Surgical intervention in treating these conditions has been very successful. Anterior approaches to the cervical spine are being used for the treatment of cervical radiculopathy and myelopathy. The technical aspects of anterior diskectomy and corpectomy, methods of fusion, and the use of instrumentation are important treatment considerations.

Bone Transplantation↗

PubMed2002

Influence of smoking on the health status of spinal patients: the National Spine Network database.

STUDY DESIGN: Multicenter, cross-sectional analysis of data from the National Spine Network. OBJECTIVES: Investigate the association between the smoking status of spinal patients, duration and severity of symptoms, and their self-reported health status. BACKGROUND: Although cigarette smoking was identified as a potential risk factor for lower back pain many years ago, more recent research is challenging this finding. METHODS: The National Spine Network database contains information on the initial visit of spinal patients visiting physicians at 23 health care institutions in the United States. All patients for whom data were available regarding smoking status are included in this study (n = 25,455). RESULTS: Data from a total of 25,455 patients (11,494 men and 13,961 women) were included in the study; 16.7% (n = 4249) were smokers. Smokers were younger than nonsmokers (44.2 vs. 48.7 years) and were more likely to report severe back symptoms (37 vs. 50%) and to report symptoms of depression (54 vs. 37%). Smokers of each gender scored 10-15 points lower than nonsmokers on each of the SF-36 subscales. These differences persisted when the absolute scores were compared with age- and sex-specific population norms and after adjustment for comorbid conditions, educational level, and depression. Similar results were obtained when the cohort was stratified by primary diagnosis or by surgical status. When postsurgical patients were grouped by time since surgery, those who were nonsmokers reported improved health status by time period; those who smoked did not. CONCLUSIONS: Smokers and nonsmokers had had spinal symptoms for similar duration, but the smokers reported more severe symptoms, which were present for a greater proportion of time each day. Also, the smokers had lower physical and mental health status scores (based on the SF-36) than did nonsmokers.

Adult↗

PubMed2002

Allogeneic transfusion requirements after autologous donations in posterior lumbar surgeries.

STUDY DESIGN: A retrospective study of blood transfusion practices after posterior lumbar spine surgery was performed. OBJECTIVES: To determine the overall use rate of autologous blood donations for different spine surgeries, and to identify the risk of requiring additional allogeneic blood transfusions. SUMMARY OF BACKGROUND DATA: In an attempt to avoid allogeneic blood transfusions and its associated risks, patients frequently are asked to donate autologous blood before many elective spine surgeries. There is a lack of published data on the use rate for these autologous blood donations, and on their ability to prevent allogeneic blood exposure. METHODS: A retrospective review of hospital charts and blood bank records was conducted on 191 consecutive patients who had undergone three categories of lumbar spine surgery: laminectomy alone, laminectomy with a noninstrumented posterolateral fusion, and laminectomy with an instrumented posterolateral fusion. RESULTS: Nearly 80% of the autologous blood donated by patients who underwent simple laminectomies was wasted. However, the vast majority (70-90%) of patients who underwent fusion used their autologous blood. In the patients who underwent fusion, autologous blood donations decreased the risk of allogenic blood transfusions by 75% in noninstrumented fusions and 50% in instrumented fusions, as compared with the patients who elected not to donate blood before the fusion (P < 0.05). A substantial number of patients who underwent instrumented fusions (nearly 40%) required additional allogeneic blood transfusions despite predonation of blood. CONCLUSIONS: Autologous blood donations are indeed advantageous in decreasing allogeneic blood usage of patients undergoing fusion, but additional methods of blood conservation (intraoperative salvage and preoperative erythropoietin) seem necessary to diminish the allogeneic blood requirements further, especially in those patients undergoing instrumented lumbar fusion.

Aged↗

PubMed2002

Transient quadriparesis in the athlete.

A considerable amount of controversy persists regarding return-to-play criteria and the risk for more severe injury after an athlete experiences an episode of transient quadriparesis. Similarly, the implication of the presence of congenital stenosis in an athlete participating in contact sports elicits great debate in the literature in terms of the athlete's risk for neurologic injury. The relatively infrequent occurrence rate of both transient quadriparesis and permanent cervical cord injury make it difficult to predict with certainty whether or not an episode of transient quadriparesis is a risk factor for permanent neurologic injury. The decision-making process in determining player eligibility in the face of congenital stenosis or after a documented spinal injury is difficult and at times confusing. Every injury and athlete should be evaluated on an individual basis in terms of cause, symptoms, radiographic findings, and previous history. It is hoped that the guidelines for return-to-play delineated in this article will help the physician and the athlete make an informed and rational decision regarding the criteria for and relative risks of returning to participation in a contact sport.

Athletic Injuries↗

PubMedDate not supplied

Quantitative analysis of gene expression in a rabbit model of intervertebral disc degeneration by real-time polymerase chain reaction.

BACKGROUND CONTEXT: Serial analysis of gene expression during the course of intervertebral disc degeneration (IDD) could elucidate valuable insight into pathophysiology and provide a basis for identification of potential targets for the development of novel cellular- and gene-based therapies. However, very few previous studies described the changes in gene expression through the process of IDD using a suitable animal model. PURPOSE: To use a recently developed rabbit annular stab model and the technique of real-time reverse transcriptase-polymerase chain reaction (RT-PCR) to quantify the change in expression of key rabbit-specific mRNA sequences encoding for selected extracellular matrix (ECM) products, catabolic, anabolic, and anti-catabolic factors in normal and stabbed discs. STUDY DESIGN: Gene expression analyses were performed to characterize a slowly progressive and reproducible animal model of IDD using real-time RT-PCR. METHODS: Twelve rabbits underwent an annular stab with a 16-gauge needle to the L2-L3, L3-L4, and L4-L5 discs, and three rabbits served as sham controls. Nucleus pulposus tissues were harvested from the stabbed discs at 3, 6, 12 and 24 weeks after confirmation of degenerative changes by magnetic resonance imaging (MRI) scan. Real-time RT-PCR was performed with the use of rabbit-specific primers for 1) extracellular matrix (ECM) component genes: collagen type Ia and IIa, and aggrecan; 2) catabolic genes: matrix metalloprotease-3 (MMP-3), inducible nitric oxide synthase (iNOS), and interleukin-1beta (IL-1beta); 3) anabolic growth genes: bone morphogenic protein-2, and -7 (BMP-2, -7), transforming growth factor-beta1 (TGF-beta1), and insulin-like growth factor-1 (IGF-1); and 4) anti-catabolic gene: tissue inhibitor of metalloprotease-1 (TIMP-1). These data were normalized to mRNA levels of glyceraldehyde phosphate dehydrogenase (GAPDH), a constitutively expressed gene. RESULTS: The MRI images confirmed progressive decline in the nucleus pulposus area of high T2 signal and in the signal intensity of the stabbed discs over the 24-week study period consistent with IDD. The ECM components, aggrecan and collagen type IIa mRNA levels had decreased markedly by week 3 and never recovered, whereas type Ia collagen mRNA gradually increased throughout course of degeneration. BMP-2, BMP-7 and IGF-1 mRNA were relatively decreased from weeks 3 to 6 but then increased at weeks 12 and 24 to end at a level near the preoperative level. The TIMP-1 expression fell dramatically to approximately one tenth of the preoperative level by week 3 and remained low throughout the degenerative process. The remaining results, including those from TGF-beta1 and the catabolic genes (MMP-3, IL-1beta, iNOS) demonstrated a double peak characteristic. The gene expression increased by week 3, decreased to a low level at weeks 6 and 12 and then had a second, late peak at 24 weeks. CONCLUSIONS: The gene expression profiles of ECM components and anabolic, catabolic, and anti-catabolic factors demonstrate many characteristics similar to the findings in human disc degeneration and suggest an inability of the intervertebral disc (IVD) to mount an early anabolic response to injury, thereby offering a possible explanation for the disc's lack of reparative capabilities. Catabolic genes are strongly up-regulated both early and late in degeneration, lending strong support to the hypothesis that an anabolic or catabolic imbalance plays a primary role in IDD. According to the resultant patterns, augmenting early production of BMP-2, BMP-7, IGF-1 or TIMP-1 by gene transfer techniques might possibly alter the progressive course of degeneration as seen in the stab model. The next step will be to transfer these therapeutic genes to regulate the biologic processes and ideally alter the progressive course of disc degeneration.

Animals↗

PubMedDate not supplied

Advances in gene therapy for intervertebral disc degeneration.

BACKGROUND CONTEXT: Gene therapy is a growing concept in many fields of medicine, and its potential applications are numerous. With a growing understanding of the molecular and cellular biology of intervertebral disc degeneration, alternatives to current treatment options are under investigation. Gene therapy offers an exciting new direction in the treatment of intervertebral disc degeneration, and potential targets of genetic alteration are being explored. PURPOSE: To describe and update the recent advances in research on gene therapy for the treatment of intervertebral disc degeneration. STUDY DESIGN/SETTING: Review of current research for the application of gene therapy as potential treatment for intervertebral disc degeneration. METHODS: Literature review. RESULTS: There is a growing body of research pertaining to the use of gene therapy as an adjunct or alternative to the current treatment options for intervertebral disc degeneration. In vitro studies have demonstrated that transfer of cDNA encoding growth factors to intervertebral disc cells can favorably modify their metabolic and biological functions. Additionally, initial in vivo studies have demonstrated successful transduction of growth factors to the intervertebral disc with confirmed upregulation of extracellular matrix synthesis. Investigators continue to explore the potential of gene therapy with several factors for the treatment of intervertebral disc degeneration. CONCLUSIONS: The potential of gene therapy to alter the course of intervertebral disc degeneration holds much clinical promise and continues to stimulate further investigations.

Animals↗

PubMedDate not supplied

Gene therapy for disc repair.

BACKGROUND CONTEXT: Recent advances in our understanding of the biologic makeup and environment of the intervertebral disc (IVD) have led to increased interest in the development of novel treatments for disc degeneration. Certain genes found to alter rates of matrix synthesis and catabolism within the disc have provided targets for scientists seeking to alter the balance between the two. To this end, gene therapy has emerged as a potential therapeutic option, and recent research efforts have yielded very promising results. PURPOSE: To update and consolidate information regarding the recent advances in gene therapy and its application to IVD degeneration. STUDY DESIGN/SETTING: Review of recent and ongoing research in the field of gene therapy, particularly regarding its application to the treatment of IVD degeneration. METHODS: Literature review. RESULTS: With its unique ability to provide sustained delivery of potentially therapeutic agents, gene therapy has shown much promise with regard to the treatment of IVD degeneration. There have been many exciting developments such as safer and more reliable vector constructs, favorable results using therapeutic transgenes in disc cells both in vitro and in vivo, and improvement in transgene regulation, and investigators continue to explore ways in which gene therapy can become a powerful tool in the future treatment of disc degeneration. CONCLUSIONS: With continued perseverance and dedication, many advances have been made in the application of gene therapy to the IVD, and it continues to demonstrate great potential to become a powerful tool in the future treatment of disc degeneration.

Biopsy, Needle↗

PubMedDate not supplied

Safety assessment of intradiscal gene transfer: a pilot study.

BACKGROUND: Several recent in vitro and in vivo studies have reported the beneficial properties of gene delivery of therapeutic factors to the intervertebral disc, as a potential treatment strategy for degenerative disc disease; however, to date, no studies have assessed the safety and toxicity of the practical application of this treatment modality. PURPOSE: To assess the safety of inappropriately dosed or misdirected gene delivery to the spinal column in an in vivo model. STUDY DESIGN: The potential toxicity of gene therapy to the spinal column was assessed in this pilot study by monitoring clinical and histological changes in the spinal cord after intradural injections of an adenoviral vector containing the complementary deoxyribonucleic acid (cDNA) for potentially therapeutic factors in the treatment of degenerative disc disease. METHODS: Fourteen New Zealand White rabbits were divided into experimental groups to receive an intradural injection (<10 microL) of saline alone or saline in combination with recombinant transforming growth factor beta1 (TGF-beta1) or an adenoviral vector containing the cDNA for either TGF-beta1 (at previously established therapeutic or elevated concentrations) or bone morphogenic protein-2 (BMP-2). Animals were monitored clinically and spinal cords were harvested for histological analysis. RESULTS: No neurological deficits developed in any of the animals receiving injections of saline alone or saline in combination with the therapeutic dose of Ad-TGF-beta1, Ad-BMP-2, or with recombinant TGF-beta1. However, animals receiving a higher concentration of Ad-TGF-beta1 developed bilateral lower extremity paralysis with significant histological changes. CONCLUSIONS: Inappropriately dosed or directed gene delivery to the spinal column may result in significant complications. However, with appropriate dosing, a therapeutic window may exist where the potential benefits of gene therapy in the treatment of degenerative disc disease outweigh its risks.

Adenoviridae↗

PubMedDate not supplied

Prospective clinical outcomes of revision fusion surgery in patients with pseudarthrosis after posterior lumbar interbody fusions using stand-alone metallic cages.

BACKGROUND CONTEXT: Posterior lumbar interbody fusion (PLIF) is a popular method of arthrodesis for surgical treatment of instabilities and degenerative conditions of the spine. With the introduction of threaded titanium cage devices, surgeons began performing PLIF procedures using these cages as stand-alone devices. Complications have been reported, however, including pseudarthrosis with persistent pain. Outcomes after revision surgical treatment for these patients with failed PLIF are not known. PURPOSE: To prospectively evaluate clinical outcomes of revision fusion surgery in patients who previously underwent posterior lumbar interbody fusion with stand-alone metallic cages resulting in pseudarthrosis. STUDY DESIGN/SETTING: Prospective case series. METHODS: Nineteen patients referred to the senior author were evaluated and diagnosed with pseudoarthrosis having previously undergone a PLIF procedure with stand-alone metallic cages. History, physical exam, and imaging studies were performed preoperatively and postoperatively. All underwent revision posterolateral fusion with iliac crest graft and pedicle screw instrumentation. Patient demographics, SF-36, and Oswestry Disability Index (ODI) data were collected prior to surgery and two years postoperatively. RESULTS: Patients undergoing revision fusion surgery were found to have had extensive facetectomies and pseudarthrosis intraoperatively. Outcomes data was collected on eighteen of nineteen patients (95%). Mean clinical follow up was 3.2 years (range 2.5-3.5 years). Seventeen patients (94%) achieved a solid fusion. Improvement was noted in seven of eight SF-36 sub-categories, but was significant only in two (Physical Function and Role Emotional). There was no significant difference in ODI scores. CONCLUSIONS: Pseudarthrosis should be considered in the differential diagnosis if severe symptoms persist in patients who undergo PLIF with stand-alone metallic cages. Successful revision fusion did not always correlate with improved clinical outcomes in these challenging patients undergoing further surgery. Performing PLIF using stand-alone metallic cages, especially after total resection of the facet joints, is not advocated unless supplemental instrumentation is utilized.

Adult↗

PubMedDate not supplied

Lumbar spine listhesis in older African American women.

BACKGROUND CONTEXT: Degenerative changes in the lumbar spine may result in a loss of spinal stability and subluxation of one vertebra relative to another. Cadaveric studies and clinical case series have suggested that listhesis may be much more common in African Americans than in whites. PURPOSE: To determine the prevalence of lumbar spine listhesis (anterolisthesis and retrolisthesis) among African American women aged 65 years and older and the relationship of listhesis to low back pain, physical function and quality of life. STUDY DESIGN/SETTING: Cross-sectional study. PATIENT SAMPLE: A total of 481 African American women aged 65 years and older who were enrolled in the Study of Osteoporotic Fractures. These women were recruited from population-based listings in Baltimore, MD, Minneapolis, MN, Pittsburgh, PA, and Portland, OR. OUTCOME MEASURES: Not applicable. METHODS: Lateral radiographs of the lumbar spine were digitized, and listhesis (anterolisthesis and retrolisthesis) was assessed at spinal levels L3-L4, L4-L5 and L5-S1. Usable data were obtained for 470 women. Listhesis was defined as present when the subluxation (antero or retro) was 3 mm or more. RESULTS: The overall prevalence of anterolisthesis was 58.3% and varied by spinal level (13.2% at L3-L4, 36.5% at L4-L5 and 29.6% at L5-S1). The prevalence increased with age but was lower among oophorectomized women and those currently on estrogen replacement therapy. Anterolisthesis was not associated (p>.05) with disc height nor was it related to back function. Retrolisthesis occurred in 4% of women and was associated with decreased disc height and an increased prevalence of spinal problems and walking problems. CONCLUSIONS: The prevalence of anterolisthesis among older African American women living in the community was two to three times greater than that found in white women of a similar age. This condition was not related to an increased frequency of back problems nor did it adversely affect general physical function. Retrolisthesis was relatively rare but was associated with decreased back function.

Black or African American↗

PubMedDate not supplied

Neck and shoulder pain in 70- to 79-year-old men and women: findings from the Health, Aging and Body Composition Study.

BACKGROUND CONTEXT: Musculoskeletal pain in the cervicobrachial region is considered a major health problem among adults of working age, but little is known about the impact of this pain in the elderly. PURPOSE: Determine the prevalence of neck and shoulder pain in a well-functioning cohort, identify factors associated with this pain, assess the pattern of coexisting joint pain and evaluate the impact of this pain on physical functioning. STUDY DESIGN: Cross-sectional study. PATIENT SAMPLE: Black and white men and women, aged 70 to 79 years, participating in the Health, Aging and Body Composition (Health ABC) study. OUTCOME MEASURES: Not applicable. METHODS: Between April 1997 and June 1998, 3,075 men and women participating in Health ABC study completed the initial home interview and clinical examination. Information was collected on musculoskeletal pain, medical history, depressive symptomatology and physical function. Physical performance measures were obtained. RESULTS: A total of 11.9% of participants reported neck pain of one month or more in duration and 18.9% reported shoulder pain. White women had the highest prevalence of neck pain (15.4%) and black women the highest prevalence of shoulder pain (24.3%). The correlates of both neck and shoulder pain were female gender, no education beyond high school, poorer self-rated health, depressive symptomatology and a medical history of arthritis, heart attack, angina. Increasing severity of both neck and shoulder pain was associated with an increased prevalence of joint pain at other body sites and with poor functional capacity. Measures of physical performance involving the upper extremity were also decreased. CONCLUSIONS: Neck and shoulder pain, either alone or in conjunction with pain in other joints, has a substantial impact on the function and well-being of the older adults in this cohort.

Age Distribution↗

PubMedDate not supplied

The effect of sunlight on postoperative analgesic medication use: a prospective study of patients undergoing spinal surgery.

OBJECTIVE: Exposure to natural sunlight has been associated with improvement in mood, reduced mortality among patients with cancer, and reduced length of hospitalization for patients who have experienced myocardial infarction. Our aim was to evaluate whether the amount of sunlight in a hospital room modifies a patient's psychosocial health, the quantity of analgesic medication used, and the pain medication cost. METHODS: A prospective study of pain medication use was conducted in 89 patients undergoing elective cervical and lumbar spinal surgery where they were housed on either the "bright" or "dim" side of the same hospital unit. Analgesic medication was converted to standard morphine equivalents for interpatient comparison. The intensity of sunlight in each hospital room was measured daily and psychologic questionnaires were administered on the day after surgery and at discharge. RESULTS: Patients staying on the bright side of the hospital unit were exposed to 46% higher-intensity sunlight on average (p = .005). Patients exposed to an increased intensity of sunlight experienced less perceived stress (p = .035), marginally less pain (p = .058), took 22% less analgesic medication per hour (p = .047), and had 21% less pain medication costs (p = .047). Age quartile was the only other variable found to be a predictor of analgesic use, with a significant negative correlation (p <.001). However, patients housed on the bright side of the hospital consistently used less analgesic medications in all age quartiles. CONCLUSION: The exposure postoperatively of patients who have undergone spinal surgery to increased amounts of natural sunlight during their hospital recovery period may result in decreased stress, pain, analgesic medication use, and pain medication costs.

Age Factors↗