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Biomedical subjects

J H Ahn

Publications and source records attributed to J H Ahn.

12 recordsLinked to original sources
PubMed1992

Motor recovery of the upper extremities in traumatic quadriplegia: a multicenter study.

Clinicians need to know recovery of neurologic function in the upper extremities after traumatic quadriplegia to prognosticate function in self-care, to determine the effectiveness of various interventions, and to develop a comprehensive rehabilitation plan. This study was undertaken to determine the extent of recovery of key muscles of the arms in motor complete quadriplegic subjects. The hypothesis stated that patients with some motor power (grades 1.0 to 2.5/5) in muscles in the zone of partial preservation would recover at an earlier time and to a greater extent than those with no motor power (grade 0/5). One hundred fifty subjects, C4, C5, and C6 motor complete, were entered in the study within one week of injury from four centers. Serial muscle examinations of the biceps, wrist extensors, and triceps on the right and left sides were performed up to 24 months after spinal cord injury. The pattern of recovery in the key muscles of the 67 subjects with some motor power in the zone of partial preservation to grade 3/5 was significantly greater than the 83 subjects with no motor power (68% to 82% vs 14% to 36%, p less than .001) at three to six months postinjury. The plateau of the median manual muscle test score determined the extent of recovery and reached grade 4/5 in subjects with some motor power at three to six months. The pattern of recovery revealed more subjects with some motor power improved to grade 3/5 at all intervals earlier than those with no motor power (p less than .005).(ABSTRACT TRUNCATED AT 250 WORDS)

Arm↗
PubMed1991

Intracellular localization of newly synthesized transferrin receptors in the peripheral sheep reticulocyte.

In this paper, we provide evidence for an incompletely glycosylated transferrin receptor (TfR) which is not transported to the plasma membrane in the sheep reticulocyte. Cleveland peptide maps of the native (preexisting) TfR and [35S]methionine-labeled TfR were different. If the receptors were deglycosylated before mapping, the peptides were identical. There was preferential binding of the [35S]TfR to Con A-Sepharose, indicating the existence of a higher density of high mannose chains on the 35S-labeled TfR. Moreover, when total [3H]mannose-labeled glycopeptides from reticulocytes were separated on a column of Bio-Gel P6, the [3H]mannose was associated with endoglycosidase H-sensitive high mannose or hybrid oligosaccharides, but not with complex sugars. After Percoll density gradient centrifugation, the [35S]TfR peaked in a fraction which separated from the bulk of the native TfR. The transmembrane glycoproteins, Band 3 and mature glycophorins, are not synthesized in the sheep reticulocyte. It appears that the reticulocyte, at this stage of red cell development, has lost the vesicles and/or proteins which are required to transport proteins from the site of translation to the cell surface.

Animals↗
PubMed1991

Inhibition of mutagenesis and transformation by root extracts of Panax ginseng in vitro.

The root extract of Panax ginseng was investigated for its inhibitory effects on DNA synthesis, mutagenicity, and cellular transformation using V79 and NIH 3T3 cells. DNA synthesis measured by the [3H]thymidine incorporation into V79 Chinese hamster lung cells was significantly decreased by the addition of ginseng extract (0-1 microgram/ml) to the medium. However, ginseng extract was found to increase the rate of DNA excision repair synthesis in V79 cells in response to treatment with UV radiation or methyl methanesulfonate. The extract also showed decreased mutation frequency when mutagenicity was examined using V79 cells at the hypoxanthine-guanine phosphoribosyl transferase locus as resistance to 6-thioguanine after exposure to methyl methanesulfonate. We also found that the components of ginseng extract continue to exert an inhibitory effect on the transformation of NIH 3T3 cells initiated by 3-methylchloanthrene, methyl methanesulfonate, and 1-methyl-3-nitro-1-nitrosoguanidine.

Animals↗
PubMed1991

A case of herpes zoster myelitis: positive magnetic resonance imaging finding.

A 33-year-old man developed a progressive myelopathy after a characteristic skin lesion of herpes zoster involving the right C3 and C4 dermatomes. The lesions were recognizable in the T2-weighted image of the magnetic resonance imaging (MRI) as increased signal intensities throughout the long segments of the spinal cord with maximal in the cervical portion, which was compatible with the pathological findings reported in autopsy studies.

Adult↗
PubMed1987

Venous plethysmography values in patients with spinal cord injury.

To determine whether venous hemodynamics differ fundamentally between patients with spinal cord injury (SCI) and the abled-bodied population, quantitation of lower extremity venous plethysmography values was performed in 14 SCI patients and ten able-bodied subjects. The control group had an average maximum venous outflow (MVO) of 59.3 +/- 2.75 mL/min/100mL of tissue, mean +/- SE, and an average venous capacitance (VC) of 3.2 +/- 0.13mL/100mL. In contrast, the SCI patients had an average MVO of 32.5 +/- 2.57mL/min/100mL and an average VC of 2.3 +/- 0.17mL/100mL. The differences between the two groups were statistically significant, suggesting that the standard venous function index of plethysmography values used in the general population may not be applicable to the SCI population and that, therefore, a new standard for SCI patients derived from a larger data base should be sought.

Adolescent↗
PubMed1985

Sudden quadriplegia after a minor trauma. The role of preexisting spinal stenosis.

Three patients are described who became quadriplegic after a minor trauma to the spine without suffering a spinal fracture dislocation. Radiologic investigation revealed marked stenosis of the spinal canal, due to developmental stenosis with superimposed degenerative changes in two patients, and calcification of posterior longitudinal ligament of the spine in one. Two patients recovered almost completely with conservative measures. The spinal cord may be able to tolerate slowly increasing mechanical pressure for many years and conform to the shape of the spinal canal without causing any neurological symptoms. However, when stenosis is severe, any additional pressure, for example, swelling and edema from trauma, may cause a neurologic catastrophe.

Aged↗
PubMed1985

Deep venous thrombosis: diagnosis in spinal cord injured patients.

Because the acute spinal cord injured patient is at high risk for the development of deep venous thrombosis (DVT), accurate diagnosis is critical. Clinical evaluation is unreliable 50% of the time, however, and the two highly accurate diagnostic procedures--venography and 125I-labelled fibrinogen scanning--are invasive and present serious drawbacks. The literature concerning the effectiveness of the two most widely used noninvasive diagnostic alternatives (Doppler ultrasound and venous occlusion plethysmography [VOP]) is equivocal. In our systematic evaluation of a series of 21 patients, using clinical examination, Doppler ultrasound and VOP, all patients who developed DVT were identified by all three methods. Overall accuracy, sensitivity and specificity were 100%.

Adolescent↗
PubMed1985

Serum albumin as a predictor of course and outcome on a rehabilitation service.

To determine the effect of nutritional status on the medical course and rehabilitation outcome of patients on an adult rehabilitation service, serum albumin (SA) and total lymphocyte count (TLC) were prospectively studied on 36 patients. Readings were taken on admission (T-1), at which time a Barthel Index Mobility Goal (BIMG) was assigned, and again 4 to 8 weeks after admission (T-2). A Barthel Index Mobility Score (BIMS) was assigned at discharge. Rehabilitation program restrictions due to medical complications correlated negatively with both the SA level at T1 (r = -.328, p less than 0.05) and at T2 (r = -.523, p less than 0.01). The SA level at T2 correlated positively with the BIMS:BIMG ratio (r = .416, p less than 0.05) at discharge, suggesting that SA levels may predict patient mobility outcome.

Adolescent↗
PubMedDate not supplied

Low ionic antiglobulin tests.

Seven serologic procedures were studied to determine their respective value in compatibility and screening tests. All seven were significantly improved by the use of 4 volumes of serum, rather than 1, with 1 volume of red cell suspension, and a low-ionic antiglobin test (LIAGT) was distinctly superior to the other six procedures evaluated. In this test, during the incubation of serum and cells at 37 degrees for 20 minutes, ionic concentration was reduced 62 percent. However, after removal of all supernatant, the red cells were washed three times with an isotonic solution that provided 80 percent reduction in ionic concentration, and the washed cells were tested for their agglutinability with low-ionic (80% ionic reduction) anti-IgG antiglobin reagent. This modified LIAGT was usually more, and apparently never less, sensitive than a test described earlier and is expected to be associated with much less nonspecificity. The extreme sensitivity of LIAGT for many long-term frozen stored alloantiserums is a retained property of the modified test and has been associated with IgG aggregation during storage.

Coombs Test↗