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Biomedical subjects

D Kim

Publications and source records attributed to D Kim.

At least 361 records · Page 20Linked to original sources
PubMed1994

[The role of magnetic resonance angiography prior to the transjugular placement of a portosystemic stent shunt (TIPS)].

The authors employed magnetic resonance angiography (MRA) to guide catheter placement for transjugular intrahepatic portosystemic stent shunt (TIPS) procedures in 14 of 24 patients, and compared the results to the 10 patients who did not have prior planning based on MRA. Two-dimensional time-of-flight venography was performed during breath holding, and projection venograms were formatted in sagittal, coronal and axial planes. MRA defined venous anatomy sufficiently well to shorten the procedure and helped to minimize invasiveness. With MRA guidance, intrahepatic needle punctures were significantly fewer (without MRA guidance: mean 12.1; with MRA guidance: mean 3.5, p < 0.001) and associated complications were absent (without MRA guidance: failed placement, N = 1; bleeding requiring blood transfusions, N = 2; death complicating intraperitoneal haemorrhage with haemobilia, N = 1, and hepatic capsular perforation, N = 1). The average time for the procedure was 2.8 hours without MRA guidance and 1.8 hours with MRA guidance (p < 0.0005). The authors conclude that MR angiography is a useful technique to define portal and hepatic venous anatomy prior to TIPS, and planning based on MRA may decrease the difficulty and length of the procedure.

Adult↗
PubMed1994

Cognitive-perceptual, interpersonal, and disorganized features of schizotypal personality.

While two factors are currently thought to underlie individual differences in schizotypal personality, three factors may best explain schizotypal traits. This study used confirmatory factor analysis to assess five competing models of schizotypal personality in the general population: null model, one-factor model, simple two-factor model, Kendler two-factor model, and three-factor model. The computer program LISREL was used to analyze Schizotypal Personality Questionnaire subscale scores that reflect the nine traits of schizotypal personality. The scores were obtained from (1) a sample of 822 undergraduates and (2) a replication sample of 102 subjects drawn from the community. Results indicate replicable support for a three-factor model reflecting cognitive-perceptual, interpersonal, and disorganized latent factors. Low intercorrelations between the first two factors and the lack of fit by a one-factor model are partially inconsistent with recent notions that a single vulnerability dimension underlies schizotypal personality. It is argued that future investigations should assess the correlates of all three schizotypal factors in clinical and nonclinical samples in addition to the two more traditional factors. It is hypothesized that three factors of schizophrenic symptomatology observed in recent studies may reflect an exaggeration of three analogous factors found in the general population.

Adolescent↗
PubMed1994

Extent of disability following traumatic extremity amputation.

Extremity amputation is a devastating injury. Forty-two patients who sustained traumatic limb amputation were contacted 3-57 months (mean, 25 months; median, 24 months) after injury to evaluate residual disability and to determine what factors were associated with a good recovery. There were 35 men and 7 women with ages ranging from 5 to 73 years (mean, 34 years). Amputation was the result of a motor vehicle crash in 18, work-related injury in 11, motorcycle crash in 9, and other causes in 4. There were 46 amputations done: 8 above-knee (AK), 25 below-knee (BK), 5 above-elbow (AE), and 9 below-elbow (BE). Twenty patients reported no problems with their prosthesis, 8 had major (e.g., infections) and 6 had minor (e.g., skin breakdown) problems. Eight patients did not receive or did not use a prosthesis. Fourteen patients were discharged to an inpatient rehabilitation facility, 25 to home with outpatient rehabilitation, and 3 had no rehabilitation. Of those who worked before their injury, only 50% returned to work. The mean and median time to return to work were 14 and 12 months, respectively. Three of five full-time students returned to school. The amputation level in patients returning to work or school was BK in 12, BE in 3, and AE in 1. No patient with a AK amputation and only 1 (9%) patient with a work-related injury returned to work. Associated injuries or inpatient rehabilitation did not correlate with returning to work. Eighty-eight percent of patients were satisfied with their adjustment and could perform all activities of daily living.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Platelet-activating factor modulates microvascular transport by stimulation of protein kinase C.

To investigate the possible involvement of protein kinase C (PKC) in platelet-activating factor (PAF)-stimulated microvascular responses, PKC inhibitors, sphingosine (SPH), 1-(5-isoquino-linylsulfonyl)-3-methylpiperazine (iso H-7), and calphostin C, were applied topically to the hamster cheek pouch, and PAF-elicited changes in microvascular permselectivity and arteriolar constriction were evaluated. Pretreatment with 10(-6) M SPH, 10(-5) M SPH, or 10(-10) M iso H-7 significantly reduced 10(-7) M PAF-induced increase in fluorescein isothiocyanate-Dextran 150 clearance (2,677.3 +/- 397.3, 2,985.3 +/- 350.7, and 2,689.3 +/- 256.0 vs. 4,784.0 +/- 474.7 nl.60 min-1.g-1, respectively). Calphostin C at 10(-7) M attenuated 10(-8) M PAF-induced increase in clearance (2,156.9 +/- 353.3 vs. 3,841.6 +/- 260.9 nl.60 min-1.g-1). Permeability changes were also measured by integrated optical intensity (IOI). Pretreatment with 10(-6) M SPH, 10(-5) M SPH, or 10(-10) M iso H-7 attenuated the maximal increment in IOI induced by 10(-7) M PAF (2,024.0 +/- 364.4, 1,690.0 +/- 525.2, and 2,432.8 +/- 655.3 vs. 4,255.9 +/- 695.6 U, respectively). Direct stimulation of PKC by phorbol dibutyrate increased clearance in dose-dependent fashion. Similarly, activation of PKC with phorbol myristate acetate increased IOI values. The PAF-induced arteriolar constriction was not blocked by the PKC inhibitors. Our results suggest that PKC represents a biochemical pathway involved in the PAF modulation of microvascular permeability but not of arteriolar constriction.

Animals↗
PubMed1994

Bronchopulmonary sequestration with MR angiographic evaluation. A case report.

Definitive diagnosis of pulmonary sequestration requires angiographic visualization of the anomalous feeding and draining vessels. The authors report a young woman who presented with persistent cough of two months' duration. Diagnosis of pulmonary sequestration was established with magnetic resonance (MR) angiography, which demonstrated abnormal feeding arteries to the sequestrum from the thoracic aorta with draining pulmonary veins.

Adult↗
PubMed1994

MR angiography of the carotid bifurcation: artifacts and limitations.

Although conventional angiography has traditionally been the preoperative study of choice before carotid endarterectomy, alternative noninvasive methods, particularly MR angiography, are being used increasingly for evaluation of the carotid bifurcation [1, 2]. In this essay, we illustrate the limitations of and artifacts associated with two-dimensional (2D) and three-dimensional (3D) time-of-flight (TOF) MR angiography vs conventional angiography when assessing disease of the carotid bifurcation.

Artifacts↗
PubMed1994

Organelle sedimentation in gravitropic roots of Limnobium is restricted to the elongation zone.

Roots of the aquatic angiosperm Limnobium spongia (Bosc) Steud. were evaluated by light and electron microscopy to determine the distribution of organelle sedimentation towards gravity. Roots of Limnobium are strongly gravitropic. The rootcap consists of only two layers of cells. Although small amyloplasts are present in the central cap cells, no sedimentation of any organelle, including amyloplasts, was found. In contrast, both amyloplasts and nuclei sediment consistently and completely in cells of the elongation zone. Sedimentation occurs in one cell layer of the cortex just outside the endodermis. Sedimentation of both amyloplasts and nuclei begins in cells that are in their initial stages of elongation and persists at least to the level of the root where root hairs emerge. This is the first modern report of the presence of sedimentation away from, but not in, the rootcap. It shows that sedimentation in the rootcap is not necessary for gravitropic sensing in at least one angiosperm. If amyloplast sedimentation is responsible for gravitropic sensing, then the site of sensing in Limnobium roots is the elongation zone and not the rootcap. These data do not necessarily conflict with the hypothesis that sensing occurs in the cap in other roots, since Limnobium roots are exceptional in rootcap origin and structure, as well as in the distribution of organelle sedimentation. Similarly, if nuclear sedimentation is involved in gravitropic sensing, then nuclear mass would function in addition to, not instead of, that of amyloplasts.

Cell Nucleus↗
PubMed1994

Semiautomated nuclear shape analysis of prostatic carcinoma and benign prostatic hyperplasia.

Nuclear shape analysis has predicted outcome better than histologic grading in patients with clinically localized prostatic carcinoma. However, the requirement for manual nuclear contour tracing makes the method tedious and slow. Currently available image analysis systems for nuclear shape analysis using light-absorption microscopy provide nuclear boundaries of insufficient clarity for automatic segmentation. We improved image resolution using confocal laser scanning microscopy, automatically detected nuclear boundaries by a multiscale segmentation algorithm and discriminated artifacts in a semiautomated way. A manual quantitative morphometry system and our semiautomated system distinguished eight cases of prostatic carcinoma from seven cases of benign prostatic hyperplasia by nuclear roundness factor, ellipticity, nuclear area and perimeter. The ease of semiautomated nuclear shape analysis should allow evaluation of large numbers of patients with known outcomes after treatment for clinically localized prostatic carcinoma to determine whether nuclear shape analysis can be extended from research to clinical usage.

Carcinoma↗
PubMed1994

Laparoscopic surgery in a mobile army surgical hospital deployed to the former Yugoslavia.

The 212th Mobile Army Surgical Hospital was deployed from a United States military base in Germany to the former Yugoslavia to provide medical support for more than 25,000 United Nations soldiers. This medical unit was the first mobile hospital ever to deploy with a capability for laparoscopic surgery. During a 2-month trial period, seven laparoscopic procedures were performed for various abdominal emergencies. There were no complications, and all patients returned to full duty within 1 week. No equipment problems or other logistical obstacles were identified. This preliminary report suggests that laparoscopic surgery is quite feasible in a forward-deployed field hospital, allowing combat soldiers to return to full duty in a much shorter time than after conventional surgery.

Abdomen↗
PubMed1993

Venodilation in Raynaud's disease.

The pathogenesis of Raynaud's disease is unclear; an enhanced response to catecholamines has been hypothesised to contribute to this vasospastic disorder. Impaired endothelium-dependent dilation occurs in other diseases associated with vasospasm, such as coronary atherosclerosis. We investigated both endothelium-dependent and endothelium-independent venodilatory function in Raynaud's disease using the hand-vein compliance technique. Full dose-response curves to noradrenaline were constructed in 10 subjects with primary Raynaud's disease and 10 age and sex matched control subjects. The two groups did not have a different response to noradrenaline. Mean (SD) log values of ED50s (the dose producing half maximum response) were 1.00 (0.59) (geometric mean 10 ng/min) in Raynaud's disease compared with 1.29 (0.66) (20 ng/min) in control subjects (p = 0.16). The efficacy of noradrenaline as a venoconstrictor was similar in the two groups: mean maximum dilation (Emax) to noradrenaline was 81 (14)% in the Raynaud's group and 89 (8)% in the control group (p = 0.08). Full dose-response curves to the endothelium-dependent dilator bradykinin were constructed. Emax to bradykinin was significantly lower in the Raynaud's group than in the control group (65 [21] vs 91 [29%], p = 0.02). ED50 values (doses producing half maximum response) for bradykinin were similar in the two groups. Maximum dilation with nitroprusside, a direct releaser of the vasodilator nitric oxide, was not diminished in the Raynaud's group (94 [23] vs 102 [15]% in controls, p = 0.26). These results suggest that endothelium-dependent venodilation is impaired in peripheral vessels in Raynaud's disease, possibly due to diminished release of nitric oxide, and may contribute to the pathogenesis of the disorder.

Angiotensin II↗
PubMed1993

Selection for amino acid sequence and J beta element usage in the beta chain of DBA/2V beta b- and DBA/2V beta a-derived myoglobin-specific T cell clones.

Previous experiments in our laboratory have demonstrated that there is a marked restriction on the TCR beta-chain usage in DBA/2 mice in response to the sperm whale myoglobin (SpWMb) determinant 110-121, predominated by the use of the V beta 8.2 gene element. We analyzed the response of mice that had been genetically depleted of V beta 8+ T cells by generating a DBA/2 line that carries the V beta a TCR haplotype. Despite the very limited TCR repertoire expressed by DBA/2V beta a mice, they made an excellent response after immunization with the SpWMb 110-121 peptide. Data presented in this manuscript demonstrate that there is an equally restricted TCR V beta-chain utilization in the T-cell response to the determinant SpWMb 110-121 in DBA/2V beta a mice. Unexpectedly, there was a shift of MHC restriction of this determinant to T cells in the V beta a strain when compared with the V beta b strain of DBA/2 mice. We had previously demonstrated that DBA/2 mice utilized both the hybrid E alpha dA beta d MHC molecule as well as the conventional A alpha dA beta d molecule as presenting elements in response to SpWMb 110-121. Data presented in this manuscript demonstrate that the T-cell response in DBA/2V beta a mice is entirely restricted by the A alpha dA beta d MHC class II molecule. By analyzing a panel of SpWMb 110-121-specific T-cell clones from DBA/2V beta a mice, we were able to study the TCR repertoire expressed on T cells from mice that lack the V beta 8.2 gene. The V beta usage by the panel of clones analyzed was remarkably homogeneous. Thirteen of the 17 clones analyzed used the V beta 1 gene segment. Perhaps more striking was the junctional region nucleotide and amino acid sequences that were shared among these clones and that were similar to the V beta 8.2 clones analyzed previously. All clones assayed used the J beta 2.6 element, as did the great majority of the V beta 8.2 clones analyzed from DBA/2 (and B10.D2) V beta b mice. Importantly, in each strain of mice, irrespective of the V beta utilized, each TCR appeared to have selected an acidic amino acid in the beta-chain at position 100.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1993

Fluorescence properties of the three tyrosine residues in the ribose-binding protein.

Three tyrosine residues but no tryptophan exist in the ribose-binding protein (RBP) of Escherichia coli. In order to assess the contribution of each tyrosine to the fluorescence properties, mutants were constructed by site-directed mutagenesis to replace tyrosines at 32, 115, and 261 by phenylalanines. The mutant proteins were functional as confirmed by in vivo tactic response and by their ability to bind to ribose. The fluorescence emission spectra of the native proteins purified from the various tyrosine mutants were measured from emission scans with a peak at 303 nm. The tyrosines, at positions 32, 115, and 261, contribute 10.0, 69.6, and 23.4%, respectively, to the total intensity of fluorescence. In completely unfolded polypeptide, these tyrosines have almost the same intensities of fluorescence, indicating that the fluorescence from tyrosines at 32 and 261 are considerably quenched in the folded, native protein.

Carrier Proteins↗