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Biomedical subjects

S B Park

Publications and source records attributed to S B Park.

At least 37 records · Page 2Linked to original sources
PubMed2001

A photoregulated ligand for the nuclear import receptor karyopherin alpha.

The ability to orchestrate the transport of proteins between nucleus and cytoplasm provides cells with a powerful regulatory mechanism. Selective translocation between these compartments is often used to propagate cellular signals, and it is an intimate part of the processes that control cell division, viral replication, and other cellular events. Therefore, precise experimental control over protein localization, through the agency of light, would provide a powerful tool for the study and manipulation of these events. To this end, a prototype photoregulated nuclear localization signal (NLS) was derived from a native NLS. A library of 30 mutants of the bipartite NLS from Xenopus laevis nucleoplasmin containing a novel, photoisomerizable amino acid was prepared by parallel, solid-phase synthesis and screened in vitro for binding to the nuclear import receptor karyopherin alpha, which mediates the nuclear import of cellular proteins. A single peptide was identified in which the cis and trans photoisomers bind the receptor differentially. The strategy used to obtain this peptide is systematic and empirical; therefore, it is potentially applicable to any peptide-receptor system.

Amino Acid Sequence↗
PubMed2001

Changes of skin blood flow and color on lesional and control sites during PUVA therapy for psoriasis.

BACKGROUND: Although the colors of psoriatic lesions, largely determined by erythema and scales, are important clinical indicators, expressing them in an objective manner is difficult. Cutaneous blood flow (CBF) also affects erythema. Serial measurement of these parameters during phototherapy was almost nonexistent. OBJECTIVE: The objectives of our study were to observe the changes of color parameters and the CBF of psoriatic lesions during PUVA therapy and to determine their clinical significance. METHODS: CBF, measured by laser Doppler flowmetry, and color parameters, measured by tristimulus colorimetry and reflectance spectrophotometry, were assessed in 13 patients with psoriasis who received PUVA therapy. RESULTS: The values of CBF, erythema index (EI), and a(*) (color parameter representing red-green axis) in psoriatic lesions were significantly different from those observed in the control sites before therapy. The parameters of psoriatic lesions normalized according to the clinical improvement and approached those of the control sites as PUVA therapy progressed. The values of melanin index (MI), L(*) (color parameter representing white-black axis), and b(*) (color parameter representing yellow-blue axis) showed no significant difference between the psoriatic plaques and the control sites. They all displayed changes toward darkening and indicated tanning induced by PUVA therapy. Serial changes presented a generally unidirectional pattern in the control sites. However, this was not always the case in psoriatic lesions because scale, infiltration, and erythema also affected the measurement of blood flow and the color of the skin. CONCLUSION: Color parameters and CBF were closely related with clinical improvement according to consecutive phototherapy. They may serve as objective indices for the visible morphology and underlying lesional pathophysiology of psoriasis.

Adult↗
PubMed2001

Neuroticism, life events and mental health: evidence for person-environment correlation.

BACKGROUND: There is some evidence that genetic effects on the likelihood of experiencing stressful life events (SLEs) are mediated by heritable traits such as cognitive ability (CA) and neuroticism (N). AIMS: To examine whether the association between CA, N and mental ill-health is driven in part by a predisposition to experience depressogenic SLEs. METHOD: Childhood measures of N and CA were available in a birth cohort of 5362 individuals. At ages 36 and 43 years, mental state and occurrence of SLEs in the previous year were assessed. Using a path-analytic approach, models with and without a hypothesised influence of N and CA on the occurrence of SLEs were compared. RESULTS: The fit of the model with childhood N having a direct influence on SLEs was good with chi 2 = 5.72, d.f. = 4, P = 0.22 at age 36 years and chi 2 = 3.50, d.f. = 5, P = 0.62 at age 43. The fit of the model was significantly worse without this path at both ages (36 years: chi 2 = 42.5, d.f. = 1, P < 0.001; 43 years chi 2 = 15.3, d.f. = 1, P < 0.001). No consistent differences were seen in comparisons of models with CA. CONCLUSIONS: The results are congruent with the suggestion that genetic effects on SLEs are mediated by personal characteristics. Part of the well-established association between N and minor psychiatric disorder may be mediated by an indirect effect of N on the likelihood of experiencing SLEs.

Adolescent↗
PubMed2001

A case of glomerulonephritis in association with pyogenic liver abscess.

Glomerulonephritis associated with visceral abscess is being increasingly recognized. The association of glomerulonephritis with visceral suppuration in the absence of endocarditis was first described by Whitworth and associates. Abscesses were most frequently located in the respiratory tract but have been reported at numerous other sites, including appendix, uterus, aorto-femoral bypass graft and cutaneous wound. This report documents the apparently rare occurrence of glomerulonephritis with acute renal failure in association with pyogenic liver abscess. The need for awareness of glomerulonephritis as a cause of acute renal failure in pyogenic liver abscess is highlighted.

Aged↗
PubMed2000

The functional anatomy of auditory hallucinations in schizophrenia.

We used continuous whole brain functional magnetic resonance imaging (fMRI) with a 3-T magnet to map the cerebral activation associated with auditory hallucinations in four subjects with schizophrenia. The subjects experienced episodes of hallucination whilst in the scanner so that periods of hallucination could be compared with periods of rest in the same individuals. Group analysis demonstrated shared areas of activation in right and left superior temporal gyri, left inferior parietal cortex and left middle frontal gyrus. When the data were examined on an individual basis, the temporal cortex and prefrontal cortex areas were activated during episodes of hallucination in all four subjects. These findings support the theory that auditory hallucination reflects abnormal activation of normal auditory pathways.

Adult↗
PubMed2000

A simple, solid-phase binding assay for the nuclear import receptor karyopherin alpha. Part 1: direct binding.

The nuclear import receptor karyopherin alpha recognizes nuclear localization signals (NLSs), peptides that direct the transport of proteins into the nucleus. A simple, colorimetric assay has been developed to facilitate the identification and comparison of karyopherin ligands by direct and competitive binding using NLSs immobilized on the solid phase (TentaGel resin).

Alkaline Phosphatase↗
PubMed2000

Measurement of femoral neck anteversion in 3D. Part 1: 3D imaging method.

Femoral neck anteversion is the torsion of the femoral head with reference to the distal femur. Conventional methods that use cross-sectional computed tomography (CT), magnetic resonance or ultrasound images to estimate femoral anteversion have met with several problems owing to the complex, three-dimensional (3D) structure of the femur. These problems include not only the difficulty of defining the direction of the femoral neck axis and condylar line but also the dependency upon patient positioning. In particular, the femoral neck axis, the direction of the femoral head, known as the major source of error, is difficult to determine from either a single or several two-dimensional (2D) cross-sectional images. A new method has been devised for the measurement of femoral anteversion using the 3D imaging technique. 3D reconstructed CT images from the femoral head and trochanter to the distal femur are used to measure the anteversion. It is necessary to remove the soft tissue from the CT images and extract just the bone part. Then, the femoral anteversion is measured from a computer-rendered femur image. The 3D imaging method is compared with both the conventional 2D method and the physical method using 20 dried femurs. For the physical method, which is used as a reference value, a special apparatus is devised. The average difference between the results of the physical method and those of the 2D CT method is 5.33 degrees. The average difference between the results of the physical method and those of the 3D imaging method is 0.45 degrees. Seventy-four patients, who suffer from toe-in-gait disease, are tested to compare the 3D imaging method with the conventional 2D CT method. The average difference between the 2D and 3D methods is 8.6 degrees, and the standard is 7.43 degrees. This method provides a very accurate and reliable measurement of femoral anteversion, as it is virtually equivalent to the direct measurement of bisected dried femur in vitro.

Adolescent↗
PubMed2000

Measurement of femoral neck anteversion in 3D. Part 2: 3D modelling method.

Femoral neck anteversion is the torsion of the femoral head with reference to the distal femur. Conventional methods that use cross-sectional computed tomography (CT), magnetic resonance or ultrasound images to estimate femoral anteversion have met with several problems owing to the complex three-dimensional (3D) structure of the femur. A 3D imaging method has been developed that virtually measures femoral anteversion on the 3D computer space with continuous CT slices; this 3D method provides more accurate and reliable results than conventional 2D CT measurements. A 3D modelling method is devised for the measurement of femoral neck anteversion. This method has advantages over the 3D imaging method, such as shorter processing time, reduced number of slices and an objective result compared with the 3D imaging method. The results of the 3D modelling method are compared with the conventional CT methods (2D CT method and 3D imaging method) using 20 dried femurs.

Femur Neck↗
PubMed2000

Comparative quantitative analysis of ultraviolet B-induced skin blood flow change using laser Doppler perfusion imaging technique.

Laser Doppler perfusion imaging (LDI), recently developed, can generate a color-coded image of tissue perfusion, making it possible to assess the spatial distribution of skin perfusion without touching the surface. Using this apparatus, we investigated ultraviolet B (UVB)-induced perfusion profile of the skin and compared the results with those obtained from laser Doppler flowmetry (LDF). Fifteen adult male Korean volunteers were irradiated with several doses of UVB ranging from 25 mJ/cm2 to 186 mJ/cm2. Twenty-four hours later, the erythema reaction was evaluated with LDF and LDI systems. There was a significant correlation between the logarithmic dose of UVB and erythema values. The curves consisted of two parts, an initial, flat phase and then a linear, steep one. Also, there was a good correlation between LDF and LDI. The LDI is as sensitive as conventional LDF, but has the many advantages of measuring blood flow over large areas without contact with the skin surface. This instrument will be useful in the measurement of skin blood flow in many areas of dermatological application.

Adult↗
PubMed2000

Posterior tibial neuropathy by a Baker's cyst: case report.

Baker's cysts are rare cause of peripheral nerve entrapment and only a few cases of tibial nerve entrapment resulting from the popliteal cyst in the calf muscle have been reported in the literature. We present a case of rheumatoid arthritis complicated by a Baker's cyst with a tibial nerve entrapment. It is important to diagnose a Baker's cyst early and to differentiate it from thrombophlebitis, a popliteal aneurysm, tumor or muscle tear to effect optimal therapy and to obviate a potential neuropathy. Prompt recognition of these cases may save the patients unnecessary procedures and delay in treatment.

Arthritis, Rheumatoid↗