PubMed HealthSearch

Biomedical subjects

H S Kang

Publications and source records attributed to H S Kang.

At least 19 recordsLinked to original sources

Effects of site-directed mutations on processing and activities of penicillin G acylase from Escherichia coli ATCC 11105.

Penicillin G acylase from Escherichia coli ATCC 11105 is synthesized from its precursor polypeptide into a catalytically active heterodimer via a complex posttranslational processing pathway. Substitutions in the pair of aminoacyl residues at the cleavage site for processing the small and large subunits were made. Their processing phenotypes and penicillin G acylase activities were analyzed. By the introduction of a prolyl residue at either position, the processing of the small subunit was blocked without a change in enzymatic activity. Four other substitutions had no effect. At the site for processing the large subunit, four substitutions out of the seven examined blocked processing. In general, penicillin G acylase activity seemed to be proportional to the efficiency of the large-subunit-processing step. Ser-290 is an amino acid critical for processing and also for the enzymatic activity of penicillin G acylase. In the mutant pAATC, in which Ser-290 is mutated to Cys, the precursor is processed, but there is no detectable enzymatic activity. This suggests that there is a difference in the structural requirements for the processing pathway and for enzymatic activity. Recombination analysis of several mutants demonstrated that the small subunit can be processed only when the large subunit is processed first. Some site-directed mutants from which signal peptides were removed showed partial processing phenotypes and reduced enzymatic activities. Their expression showed that the prerequisite for penicillin G acylase activity is the efficient processing of the large subunit and that the maturation of the small subunit does not affect the enzymatic activity.

DNA Mutational Analysis

Variations of the ventral rami of the brachial plexus.

We studied the variations in the ventral rami of 152 brachial plexuses in 77 Korean adults. Brachial plexus were composed mostly of the fifth, sixth, seventh and eighth cervical nerves and the first thoracic nerve (77.0%). In 21.7% of the cases examined, the fourth, fifth, sixth, seventh and eighth cervical and the first thoracic nerves contributed to the plexus. A plexus composed of the fourth, fifth, sixth, seventh and eighth cervical and the first and second thoracic nerves, and a plexus composed of the fifth, sixth, seventh eighth cervical nerves were also observed. The plexuses were classified into three groups according to cephalic limitation, and the plexus of group 2 in which the whole fifth cervical nerve enters the plexus, were observed the most frequent. The average diameter of the sixth and the seventh cervical ventral rami of the plexus was greatest and that of the fifth cervical was smallest. The largest nerve entering the plexus was the sixth or the seventh cervical nerve in about 79% of cases. The dorsal scapular nerve originated from the fifth cervical ventral ramus in 110 cases (75.8%). The long thoracic nerve was formed by joining of roots from the fifth, sixth, and seventh cervical nerves in 76.0% of cases. Also, a branch to the phrenic nerve, the suprascapular nerve, a nerve to the pectoralis major muscle and a nerve to the subscapular muscle arising from the ventral rami of the plexus were observed.

Brachial Plexus

Anatomical observation on draining patterns of saphenous tributaries in Korean adults.

This study was done to identify the normal and variants of saphenous tributaries in Korean adults. The pattern of confluence of saphenous tributaries, medial accessory saphenous, lateral accessory saphenous, superficial epigastric, superficial circumflex iliac and superficial external pudendal veins, was carefully examined in 249 lower limbs (right, 129; left, 120) of embalmed Korean cadavers (73 males & 56 females). The medial accessory saphenous vein drained into the great saphenous vein directly (in 82.3%) or by a common trunk (in 17.7%) with the superficial epigastric or superficial external pudendal vein. The lateral accessory saphenous vein entered the great saphenous (in 67.1%) or the femoral vein (in 32.9%) directly or, forming a common trunk with other saphenous tributaries. The superficial epigastric vein joined the great saphenous (in 77.1%) or the femoral vein (in 22.9%) directly or, by a common trunk with other saphenous tributaries. The superficial circumflex iliac vein reached the great saphenous (in 83.1%) or the femoral vein (in 16.9%) directly or, by a common trunk with other saphenous tributaries. The superficial external pudendal vein opened into the great saphenous (in 95.2%) or the femoral vein (in 4.8%) directly or by a common trunk with other saphenous tributaries. In Koreans, the incidence of the normal pattern of saphenous tributaries was 23.7% and in 76.3% any one of variant saphenous tributaries entered the femoral or the great saphenous vein by a common trunk with other saphenous tributaries.

Adult

Characterization and purification of the 94-kDa glucose-regulated protein.

Increased synthesis of so-called glucose-regulated proteins (grp) of 78 and 94 kDa occurs in mammalian cells exposed to a variety of agents, including 2-mercaptoethanol, tunicamycin, agents which perturb calcium homeostasis, and amino acid analogs. Herein we describe a number of properties of 94-kDa grp (grp 94) and present a method for its purification to homogeneity. The protein, within the endoplasmic reticulum (ER), is modified by the addition of high mannose-containing oligosaccharides. The predicted amino acid sequence of grp 94, as determined by others, has revealed the protein to contain a putative transmembrane domain near its amino terminus, but in addition, a potential endoplasmic reticulum retention sequence (KDEL) at its COOH terminus. Consequently, the question of whether grp 94 exists as a transmembrane or luminal protein of the ER remains controversial. Results using isolated microsomes subjected to either limited proteolysis or lactoperoxidase-mediated iodination were consistent with the idea that the grp is a transmembrane protein. On the other hand, using the method of sodium carbonate extraction, grp 94 exhibited properties of both a luminal and integral membrane protein. These results raise the question of whether there exist two different forms of grp 94 within the ER.

Animals

Response of mammalian cells to metabolic stress; changes in cell physiology and structure/function of stress proteins.

In response to adverse changes in their local environment, cells or tissues from all organisms increase the expression of a group of proteins referred to as heat shock or stress proteins. Collectively, the stress proteins are thought to provide the cell with some degree of protection during the environmental insult as well as facilitate the repair and recovery of metabolic pathways perturbed as a consequence of the stress event. Within the past few years it has become apparent that most all of the stress proteins are present in appreciable levels in the unstressed cell and are involved in a number of very basic and essential biochemical pathways. The present review has discussed pertinent changes in cell physiology in mammalian cells experiencing metabolic stress. In addition, considerable attention has been given to discussing the properties and possible functions of the individual stress proteins.

Animals

Triangular fibrocartilage and intercarpal ligaments of the wrist: MR imaging. Cadaveric study with gross pathologic and histologic correlation.

To provide further understanding of the magnetic resonance (MR) signal intensities in the triangular fibrocartilage (TFC) and interosseous ligaments of the wrist, the authors performed MR imaging with gross pathologic and histologic analysis in 10 cadaveric wrists. Spin-echo T1- and T2-weighted coronal images were obtained, and 3-mm coronal sections of the specimens were then made that correlated precisely with the MR images. Normal portions of the TFC showed asymmetrical bow tie-like low signal intensity, except near the radial and ulnar attachments. Degeneration of the TFC, present in all cases, was more severe on the proximal surface and was characterized by high signal intensity on T1-weighted images and less high signal intensity on T2-weighted images. These findings differed from those in TFC perforation, which showed high signal intensity on T2-weighted images. Similar signal intensity characteristics could allow differentiation of degeneration and perforation of the scapholunate and lunotriquetral ligaments. These findings suggest that in vivo MR imaging may accurately delineate degeneration and perforation of the TFC and intercarpal ligaments.

Cadaver

[A study on perceived family support and anxiety in hemiplegic patients].

The purposes of this study were to identify causal factors of Anxiety and to analyze correlation between perceived family support and anxiety in hemiplegic patients. The subjects of this study were 88 hospitalized hemiplegic patients at Kyung-Hee Oriental medicine Hospital. Data were collected by using interview with questionnaire from Jan. 15 to Mar. 31, 1990. The measurement tools used by this researcher were Kang's family support scale, Spielberger's trait anxiety scale and the other anxiety scale which was developed by this researcher, approved it's reliability and validity. For the purposes of the study, the collected data were analyzed by frequency, t-test, ANOVA and the hypothesis was tested by pearson correlation, partial correlation. The results of the study were as follow. 1) The analysis of causal factor of anxiety higher anxiety these three cases; (1) 1st causal factor was the delayed recovery of paralyzed upper limbs (2.42 +/- 1.27). (2) 2nd causal factor was the dysfunction of physical ability (2.30 +/- 1.29). (3) 3rd causal factor was difficulty for walking (2.30 +/- 0.83) and the anxiety level (2.02 +/- 0.83) of physical factor was the highest level than any other factors. 2) The hypothesis that the more perceived family support level is the less anxiety level of patient was supported (r = -.29, p = .003). 3) The analysis of the general characteristics exerting influences on anxiety level patients; (sex, age, marital status, religious, education level, occupation, economic status, experience of hospitalization, care giver, the period of hospitalization, side of paralysis). In this analysis, any factor has not a statistical significance. (p greater than .05). 4) The analysis of the relationship about effective factors of family support level by the general characteristics of patient (sex, age, marital status, religious, education level, occupation, economic status, experience of hospitalization, care giver, the period of hospitalization, side of paralysis). In this analysis, there was significant difference on perceived family support between married and bereaved patients (t = -2.68, p = .009). As a result of this study, anxiety level of physical factor was higher than any other factors (psychological factor, social factor) and the delayed recovery of paralyzed upper limbs is the largest causal factor of anxiety of physical factor. Meanwhile, the relationship between the degree of family support and the level of anxiety was negatively correlated but the degree of relationship was low. Therefore, one can infer from this study that sufficient information about recovery of physical problems and family support were effective in preventing and reducing anxiety in hemiplegic patient.

Anxiety

Osteophytosis of the knee: anatomic, radiologic, and pathologic investigation.

Although the radiologic manifestations of degenerative disease of the knee have been investigated, the distribution of marginal and central osteophytes has not been defined. This study included (a) 50 consecutive patients with osteoarthritis of the knee in whom routine and specialized projections were obtained prospectively, (b) 25 patients with calcium pyrophosphate dihydrate (CPPD) crystal deposition disease whose knee radiographs were retrospectively reviewed, and (c) four cadaveric knees that were dissected to assess pertinent anatomy. In this study the importance of the tunnel view in the evaluation of osteoarthritis and CPPD crystal deposition disease is demonstrated, the distribution of and the relationship between marginal and central osteophytes are discussed, and two new radiologic signs are described. As both marginal and central osteophytes may simulate intraarticular bodies, the recognition of these outgrowths is of clinical importance.

Calcium Pyrophosphate

Demonstration of the scapholunate space with radiography.

The importance of radiographic evaluation of the scapholunate space, which should not be wider than 2 mm, has been well established in cases of wrist injury. Unfortunately, the assessment of this space is not accurately determined with routine posteroanterior (PA) radiographs, because the scaphoid and lunate bones often overlap. Moreover, the exact portion of the scapholunate space that should be measured has never been clearly defined. Nine wrists with a scapholunate space no wider than 2 mm and without chondrocalcinosis were studied by means of plain routine views and special projections, transaxial and coronal computed tomographic scans, and dissection to determine the precise orientation and anatomy of this space. A PA radiograph with 10 degrees of tube angulation from the ulna toward the radius best demonstrated the scapholunate space. This space should be measured at the level of the midportion of the flat lateral facet of the scaphoid.

Carpal Bones

Scapholunate advanced collapse: a common wrist abnormality in calcium pyrophosphate dihydrate crystal deposition disease.

Scapholunate advanced collapse (SLAC) is a pattern of wrist malalignment that has been attributed to posttraumatic or spontaneous osteoarthritis of the wrist. Its features, however, also have been observed in patients with idiopathic calcium pyrophosphate dihydrate (CPPD) crystal deposition disease. To determine the frequency and characteristics of SLAC in this disease, the authors reviewed wrist radiographs in 168 well-documented cases of this disorder. Forty-four of the cases (26%) revealed wrist abnormalities typical of SLAC. Associated findings included bilateral involvement (63%); calcification in or near the triangular fibrocartilage (70%); scapholunate widening or dissociation (70%); and arthropathies of the trapezioscaphoid (57%), metacarpophalangeal (second through fifth) (52%), first carpometacarpal (40%), and radiolunate (14%) joints. Results strongly suggest that CPPD crystal deposition disease is one of the major causes of SLAC. Furthermore, radiolunate arthropathy was found in 14% of the patients with SLAC and CPPD crystal deposition disease, which is different from other observations.

Aged

Is MR better than arthrography for evaluating the ligaments of the wrist? In vitro study.

The purpose of this study was to determine the relative merits of MR imaging and three-compartment digital arthrography in the assessment of carpal ligaments in vitro. We performed MR imaging and arthrography in 10 normal wrists of fresh cadavers ranging in age from 48 to 71 years, and compared the appearance of the interosseous ligaments and triangular fibrocartilage complex with findings on anatomic sections of the joints. In six of the specimens, relatively T1-weighted MR images, 800/20 (TR/TE), preceded three-compartment digital arthrography performed with standard contrast material. In the other four specimens, arthrography, using an MR solution of iodinated contrast material mixed with cupric sulfate and gelatin, was performed before MR imaging. This was done to mimic the intraarticular fluid that might be seen in an injured wrist. MR allowed accurate assessment of the triangular fibrocartilage complex and scapholunate ligament in eight of 10 cases. Consistent MR visualization of the lunotriquetral ligament was difficult. Three-compartment digital arthrography allowed accurate assessment of the triangular fibrocartilage complex and scapholunate and lunotriquetral ligaments in all 10 cases. We concluded that MR is useful but inferior to arthrography in the evaluation of interosseous ligaments and the triangular fibrocartilage complex.

Aged

Insufficiency fracture of the sternum caused by osteopenia: plain film findings in seven patients.

Sternal insufficiency fractures, whether nonbuckling (displaced or nondisplaced) or buckling, are rare and have been described in elderly osteopenic patients with accentuated kyphosis of the thoracic spine. We retrospectively analyzed the radiographs and clinical records in seven osteopenic patients with sternal insufficiency fractures and correlated the type of insufficiency fracture with the presence and degree of dorsal kyphosis, as well as the presence of chest pain, soft-tissue mass, and osteolysis. We found that displaced or nondisplaced nonbuckling fractures (five patients) may be associated with chest pain localized to the sternum (three patients), and may be present with (three patients) or without (two patients) associated thoracic kyphosis. This type of insufficiency fracture also may be accompanied by a soft-tissue mass and osteolysis (three patients), findings simulating pathologic fractures. All buckling insufficiency fractures (two patients) were associated with thoracic kyphosis and were asymptomatic. Our findings suggest that sternal insufficiency fractures may occur with or without exaggerated dorsal kyphosis. The fractures are an uncommon complication of osteopenia and may resemble pathologic fractures when osteolysis and soft-tissue swelling are present.

Adult

Sequence-specific functions of the early palindrome domain within the SV40 core origin of replication.

The early palindrome domain within the SV40 core origin of replication is essential for the initiation of replication. Studies with single point mutants in this region suggested that the early palindrome domain does not function as a cruciform structure, but may be involved in the initiation of SV40 DNA replication in a sequence-specific manner. Two mutants, base-substituted at a primase initiation site nucleotide 5214, showed dramatic decreases in DNA replication in monkey cells. Despite earlier reports to the contrary, disruption of the cruciform configuration or polypyrimidine tract does not invariably lead to lack of replication function, as some mutants unable to form this structure replicate normally. Gel retention assays and DNase I footprinting with the nuclear proteins of monkey cells showed that the 5'GAGGC3' pentanucleotide repeats on either side of early palindrome domain interact with monkey nuclear protein. The early palindrome domain may affect the interaction of SV40 DNA with nuclear protein, and participate in SV40 DNA replication.

Animals

Intraosseous fat necrosis associated with acute pancreatitis: MR imaging.

Necrosis of fatty bone marrow, caused by lipolytic enzymes, is a rare complication of several pancreatic disorders. A 44-year-old man with polyarthritis, subcutaneous nodules, and osteolysis associated with alcoholic pancreatitis underwent magnetic resonance (MR) imaging of the knees. In the marrow of the distal femur and proximal tibia, the images showed multiple foci of abnormal signal intensity compatible with the diagnosis of fat necrosis secondary to acute pancreatitis. Because MR imaging can depict abnormalities in fatty marrow that seem to precede necrosis, this modality may add early diagnostic information.

Acute Disease

[The use of nursing diagnosis in practice].

This study was conducted to investigate the present situation and problems related to the use of nursing diagnosis in practice. The data were obtained from 332 subjects (27 director of nursing service, 302 staff nurses) who worked in university hospitals in Korea from July through August 1988 using a mailed questionnaire. Data were analyzed by frequency, X2 test and t-test. The findings were as follows: 1. Clinical use of nursing diagnosis by directors of nursing service and staff nurses. 1) The majority of the nursing departments (88.9%) conducted group education on nursing diagnosis during the last 5 years and 81.5% of them kept a record format for nursing diagnosis; 88.9% of them had had prior experience with the nursing diagnosis. 2) Most of nurses (97.0%) had received education on nursing diagnosis. 2. Factors related to the clinical use of nursing diagnosis in nursing service departments and by staff nurses. 1) The one factor related to the use of nursing diagnosis in the nursing service department was the existence of a record. 2) Factors related to the use of nursing diagnosis by the staff nurses were the organization style of the nursing service department, group education during the last 5 years, existence of a record, the attitude of the director of nursing service, and prior experience of the use of the nursing diagnosis as characteristics of nursing service department and educational experience of nursing diagnosis as a character of nurse. 3. Problems with the use of nursing diagnosis. 1) The primary problem was the lack of time and personnel (mean:3.757); the second problem was the lack of knowledge and will to use nursing diagnosis in practice by the staff nurses (mean:3.546). 2) There was no significant difference in problems expressed by the director of nursing services and the nurses. The majority of nurses who worked in the university hospitals expressed interest in and concern about the use of nursing diagnosis. Most of the nurses had had education about on nursing diagnosis but use in practice was limited. The primary problem was lack of time and manpower.(ABSTRACT TRUNCATED AT 400 WORDS)

Attitude of Health Personnel

[The effects of clinical application of a nursing diagnosis protocol].

This study was conducted to measure the effects of clinical application of a Nursing Diagnosis Protocol. The dependent variables were the degree of patient's satisfaction and the degree of nurse's satisfaction with the nursing activity. Analysis of the effect of the use of the nursing diagnosis protocol was based on the nursing record. The subjects for this study were 61 nurses (experimental group 31, control group 30) and 155 patients (experimental group 55, control group 100) on four internal medicine wards in K University Hospital in Seoul.

Clinical Protocols