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Biomedical subjects

G W Lee

Publications and source records attributed to G W Lee.

At least 37 records · Page 2Linked to original sources

The role of bone scintigraphy in diagnosing reflex sympathetic dystrophy.

Three-phase bone scintigraphy is used often to diagnose reflex sympathetic dystrophy of the hand. This study presents an analysis of the literature relating three-phase bone scanning to reflex sympathetic dystrophy in the upper extremity. The data show a wide variability in scintigraphic accuracy in patients with clinically obvious reflex sympathetic dystrophy. The results of bone scintigraphy correlate best with the clinical diagnosis of reflex sympathetic dystrophy within the first 20-26 weeks of onset. Even then, the sensitivity in the most recent series approximates 50%. After 26 weeks, there is a poor correlation between three-phase bone scanning and reflex sympathetic dystrophy. Consequently, three-phase bone scintigraphy should not be used as a major criterion in diagnosing reflex sympathetic dystrophy. The diagnosis of reflex sympathetic dystrophy remains a clinical diagnosis made by an experienced hand surgeon.

Bone and Bones↗

Restoration of shoulder abduction by nerve transfer in avulsed brachial plexus injury: evaluation of 99 patients with various nerve transfers.

During the 5-year period between 1987 and 1991, 99 patients with total root or upper root (C5, C6, or C7) injuries were treated by nerve transfer to obtain shoulder abduction. More than eight different combinations of coaptation between donor nerves (intercostal nerves, phrenic nerve, spinal accessory nerve, ipsilateral C7, or cervical motor nerves) and recipient nerves (suprascapular nerve, axillary nerve, and upper trunk or C5) were applied. All patients had at least 2 years of follow-up. Different results were obtained in each category. Simultaneous neurotization of the suprascapular and axillary nerves with the phrenic and spinal accessory nerves obtained much better and more reliable shoulder abduction. Neurotization of the C5 spinal nerve by multiple nerve transfers was another good option that yielded good shoulder abduction in a single patient. If the phrenic nerve was traumatized, neurotization of the suprascapular nerve solely with the spinal accessory nerve was still capable of achieving an acceptable range of shoulder abduction.

Adolescent↗

Relationship of TSG-14 protein to the pentraxin family of major acute phase proteins.

TNF-stimulated gene-14 (TSG-14) encodes a secreted glycoprotein with significant sequence homology to C-reactive protein (CRP) and serum amyloid P component (SAP), members of the pentraxin family of acute phase proteins. TSG-14 mRNA was elevated in human FS-4 fibroblasts by treatment with TNF, IL-1, or bacterial LPS, and weakly by dexamethasone. Abs to recombinant TSG-14 immunoprecipitated a 42-kDa protein from the culture supernatants of TNF- or IL-1-stimulated FS-4 cells. TSG-14 protein was also inducible in the Hep3B human hepatoma cell line by TNF, IL-1, IL-6, or dexamethasone. CRP protein, identified by immunoprecipitation of a 25-kDa band with Abs to CRP, was induced in Hep3B cells by IL-1, IL-6, or dexamethasone. Immunoprecipitations with polyclonal Abs to TSG-14 and CRP suggested that the two proteins are immunologically cross-reactive. Appearance of TSG-14 protein was demonstrated in the serum of mice after injection with LPS. No TSG-14 mRNA was detected in the liver of LPS-injected mice, suggesting that hepatocytes are not the major site of TSG-14 synthesis. Thus, in the intact organism the main cellular sources of TSG-14 and classical acute phase proteins appear to be different.

Acute-Phase Proteins↗

Provocative testing for cubital tunnel syndrome.

This prospective study evaluated the clinical usefulness of provocative testing in 32 subjects with electrodiagnostically proven cubital tunnel syndrome and 33 control subjects. Four provocative tests were included: Tinel's sign, elbow flexion, pressure provocation, and combined elbow flexion and pressure provocation. The mean age of the control group was 41 years and 46 years for the group with cubital tunnel syndrome. In the control group, provocative tests were rarely positive. In 44 extremities with cubital tunnel syndrome, 31 had a Tinel's sign, 33 had a positive elbow flexion test, 39 had symptoms with pressure only, and 41 had symptoms with a combination of pressure provocation and elbow flexion testing. The sensitivity of the Tinel sign was 0.70, and at 30 seconds, the sensitivities of the other provocative tests were: elbow flexion (0.32), pressure provocation (0.55), and pressure-flexion test (0.91). The most sensitive provocative test in the diagnosis of cubital tunnel syndrome was elbow flexion when combined with pressure on the ulnar nerve.

Adult↗

TSG-14, a tumor necrosis factor- and IL-1-inducible protein, is a novel member of the pentaxin family of acute phase proteins.

TNF-stimulated gene (TSG)-14 was originally identified as a TNF-inducible gene in a differentially screened cDNA library derived from TNF-treated normal human FS-4 fibroblasts. Analysis of the TSG-14 cDNA sequence revealed a major open reading frame encoding a protein of 381 amino acids, including a hydrophobic signal peptide sequence. The predicted protein shows 23 to 27% sequence homology to C-reactive protein and serum amyloid P-component, members of the pentaxin family of acute phase proteins. In addition, TSG-14 protein contains a sequence motif common among the pentaxin proteins. The ability of the TSG-14 cDNA to encode a protein of the correct molecular size was confirmed in a cell-free transcription/translation system. In vitro translation in the presence of microsomes confirmed that the protein has a cleavable signal peptide sequence, and that it is glycosylated. TSG-14 mRNA is rapidly elevated from almost undetectable levels in untreated FS-4 cells to high levels in cells treated with TNF or IL-1. A moderate increase in TSG-14 mRNA was observed in FS-4 cells treated with the glucocorticoid dexamethasone. Nuclear run-on analysis indicated that TNF induces the expression of the TSG-14 gene at the transcriptional level, and that de novo protein synthesis is not required for induction of TSG-14 mRNA. Expression of TSG-14 mRNA was also detected after exposure to TNF in vascular endothelial cells; however, little or not expression of TSG-14 message was observed in cell lines derived from malignant tumors. Our data strongly suggest that TSG-14 is a novel member of the pentaxin family of acute phase proteins.

Acute-Phase Proteins↗

Reconstruction of a near total male urethral defect with a microvascular free flap.

We describe a new technique for reconstruction of a traumatic near total male urethral defect. With this procedure a microvascular free flap transfer of the radial forearm skin is used to create a 23 cm. neourethra extending from the urogenital diaphragm to the glans of the penis. This single-stage transfer allows large traumatic wounds to heal, enables the patient to urinate while standing without strictures, and maintains urinary continence.

Humans↗

A technique for nerve reconstruction following resection of soft-tissue sarcoma.

Primary nerve grafting should be considered whenever tumor extirpation necessitates resection of an adjacent critical nerve. A technique of nerve grafting is presented which distinguishes motor from sensory fascicles, using intraoperative electrical stimulation. Stimulation of individual motor fascicles is performed proximal and distal to the lesion, and fascicles which produce the same muscle contraction are identified. Motor and silent sensory fascicles are tagged prior to tumor resection. This facilitates subsequent specific motor/sensory reconstruction of the defect, using intrafascicular grafting techniques.

Adolescent↗

Evaluation of fox-chasing enclosures as sites of potential introduction and establishment of Echinococcus multilocularis.

Following detection of Echinococcus multilocularis in red foxes (Vulpes vulpes) illegally imported into South Carolina (USA) for release in fox-chasing enclosures, a survey for E. multilocularis was conducted in four enclosures in Georgia (USA) and six enclosures in South Carolina. Survey methods included examination of potential small mammal intermediate hosts (n = 390) for E. multilocularis larvae, examination of fox and coyote (Canis latrans) scats (n = 59) for taeniid eggs, and examination of one possible canine definitive hosts for adult E. multilocularis. All intermediate and definitive hosts examined were negative for E. multilocularis and taeniid eggs were not recovered from fox and coyote fecal samples. Thus, E. multilocularis may not yet be established in fox-chasing enclosures in Georgia and South Carolina. Despite the failure to demonstrate E. multilocularis in the fox-chasing enclosures surveyed, translocation of wild canids from known enzootic regions should be discouraged because E. multilocularis is known to be ecologically adaptable and because contact with potentially infected definitive hosts during translocation is a public health risk.

Animals↗

Advances in total phalloplasty and urethroplasty with microvascular free flaps.

This article focuses on the lateral arm free flap as the option that comes closest to meeting the diverse aesthetic and functional goals of phalloplasty. The authors introduce a new technique for incorporating a prefabricated neourethra within the lateral arm to permit the coexistence of an erectile prosthesis alongside a fully vascularized urethra that extends to the distal tip. The unrecognized value of the radial forearm free flap for urethroplasty is also discussed and a case of reconstruction following urethral loss is presented. Also described is how the prefabricated urethra technique may be useful for repairing severe hypospadias defects.

Humans↗

Isolation and characterization of eight tumor necrosis factor-induced gene sequences from human fibroblasts.

A lambda cDNA library was prepared from polyadenylated RNA isolated from quiescent human diploid FS-4 fibroblasts stimulated with tumor necrosis factor for 3 h. Differential screening was used to isolate cDNA sequences that are stimulated by tumor necrosis factor. Eight distinct tumor necrosis factor-stimulated gene sequences (designated TSG-1, -6, -8, -12, -14, -21, -27, and -37) were partially sequenced and compared with known sequences from GenBank. TSG-1 was identical to the gene for interleukin-8. TSG-8 corresponded to the gene for monocyte chemotactic and activating factor. TSG-21 and -27 were identical to the genes for collagenase and stromelysin, respectively. The other four sequences showed no homologies with known genes. Patterns of induction of mRNAs corresponding to the eight cloned cDNAs by various cytokines, growth factors, and activators of second messenger pathways were analyzed in FS-4 cells.

Base Sequence↗

Usefulness of echocardiography in the prediction of early results of catheter balloon mitral valvuloplasty.

Catheter balloon mitral valvuloplasty (BMV) was performed in 50 patients and 32 of them undergoing BMV with double balloon technique were studied to evaluate the usefulness of echocardiography in the prediction of early results of BMV. Five echocardiographic variables including mitral valve motion, mitral valve thickness, subvalvular change, commissural calcification and left atrial dimension were evaluated. Each variable was divided into mild, moderate and severe subgroups. Before valvuloplasty there were no differences in mitral valve area among any subgroup for any variable. After valvuloplasty, variables associated with a greater increase in mitral valve area from mild and moderate subgroups than from severe subgroup included mitral valve motion, mitral valve thickness, and subvalvular change, but not commissural calcification or left atrial dimension. We scored the former 3 variables as 0, 1 and 2 points in the mild, moderate and severe subgroups, respectively. The sums of individual scores in these 3 variables were further divided into 3 groups: 12 patients had a lower score (less than 2), 10 patients had a score of 3-4 and 10 patients had a higher score (greater than 5). Patients with lower scores tended to have greater increases in mitral valve areas after valvuloplasty than those with higher scores. Thus, mitral valve motion, mitral valve thickness and subvalvular change may be useful to predict a greater increase in mitral valve area after valvuloplasty. A lower score of echocardiographic variables anticipates successful balloon mitral valvuloplasty, which may be helpful in patient selection.

Adult↗

Reanimation of the long-standing partial facial paralysis.

Those unfortunate people who suffer from permanent partial facial paralysis have great difficulty finding surgeons who can offer corrective operations. Improving their function is a most delicate procedure. Great care must be exercised to avoid injuring nerves and muscles which are still operating, although in a greatly diminished state. The pathogenesis must be understood before attempting any corrective procedure. Adequate time must elapse from the moment of injury to surgical intervention, thus allowing for maximal nerve and muscle regeneration. This paper describes techniques that could improve facial movements. The most frequently used procedure is shortening of the levator and/or the zygomatic muscles that are partially atrophied. It must be understood that total reanimation is impossible as of this time.

Adolescent↗

Cell death in the adult rat dorsal root ganglion after hind limb amputation, spinal cord transection, or both operations.

Cell death of embryonic neurons which are unable to attain a proper target is well established. A delayed cell death of adult neurons permanently separated from their target tissue has been demonstrated for several cell groups. Cells of the dorsal root ganglia (DRG) are unique in that a single T-shape neurite has a peripheral branch which extends (for root L5) to the hind limb and a central branch extending into the spinal cord. We found a significant loss of L5 DRG neurons 25 weeks after hind limb amputation. This finding is consistent with the hypothesis that neuron survival is dependent on connection with a suitable target. We were unable to detect cell death in the DRG of L5 after complete spinal cord transection at T9. Separation of DRG cells from their central target is unimportant to neuronal survival.

Amputation, Surgical↗

Cell death in Clarke's column after spinal cord transection.

The death of embryonic central nervous system (CNS) neurons deprived of a target is well established. In adult rats, similar cell death of corticospinal and rubrospinal motor neurons occurs as a delayed response to spinal cord transection. We document the loss of neurons in Clarke's column, secondary ascending spinocerebellar neurons in adult rats, after complete spinal cord transection at T-9. Twenty-five weeks after spinal cord transection, horseradish peroxidase (HRP) studies showed a dramatic loss of labeled cells in rats with transected spinal cords as compared to matched control rats. Cresyl echt violet-stained sections failed to support the hypothesis that unlabeled cells persist in a shrunken, inactive state; instead we found far fewer identifiable neurons in Clarke's column. Although we saw little gliosis in the area of cell loss, gliosis was evident in the adjacent corticospinal tract which was severed in the original surgical injury. Amputation of the right hind limb resulted in a paradoxical increase in labeled Clarke's column cells on the right. Total cells stained with cresyl echt violet in amputated animals were not different from right to left. The increase in labeled cells on the amputated side may have been caused by an increase in metabolic activity of these deafferentated neurons which resulted in more effective axoplasmic transport of the HRP label.

Animals↗