Biomedical subjects

M J Kim

Publications and source records attributed to M J Kim.

At least 37 records · Page 2Linked to original sources

PubMed2005

The hormonal fountains of youth: myth or reality?

There has been a long search for the best approach of ensuring successful aging. The remarkable demographic transformations in this century have not only led to increased medical needs of older people, who often have multiple chronic conditions, decrements in functional ability and age-related disease, but also to the increase of social expenditures, such as pension funds and health insurance to support them. Therefore, it is no wonder that there is now a great endeavor to find a fountain of youth in both society and individuals. In this review each of the hormones that have been suggested to play a role in rejuvenating older persons, ie, the so-called "hormonal fountain of youth" is briefly discussed. Any hope of a fountain of youth to stop people from getting older, however, is a long way off, with science just beginning to understand the complex genetic, physical and hormonal causes of aging. An essential, but still unanswered question, is whether the age-related decline in hormone systems is physiological, perhaps conveying a benefit, or if the changes are pathological, causing harm. Modern research has, however, demonstrated that the concept of a "hormonal fountain of youth" is predominantly mythological.

Aging↗

PubMed2004

Food technology: challenge for health promotion.

The food technology has brought countless benefits to today's food supply. Despite its many positive contributions, it has also brought unintended negative consequences. It is the time to mobilize the food technology to help the food supply more secure, safer and healthier, and here three possible approaches are foreseeable: First, we should continue to improve the conventional technologies. Many wholesome foods have been prepared and preserved using natural materials simply by fermentation. Second, we have to enhance the minimal processing as much as applicable. Third, new ingredients, intelligent packaging and functional foods should be explored to improve food supply and health. Today, consumer interest in the functional foods has been increased tremendously, and the future of food lies in the functional foods. However, the situations in the developing world are different from this. As food resource is limited in this region, food technology has to be emphasized to increase food supply. To help solve such complex problems, not only new technologies, but also conventional technologies have to be mobilized. Simultaneously, even higher technical capabilities have to be built up by applying new findings from the related disciplines to allow the food technology to play its vital role.

Food Handling↗

PubMed2004

Acquired syngnathia.

We report two cases of acquired syngnathia, in case 1 probably as a result of a fibrotic tubed pedicle and in case 2 from myositis ossificans. The treatment plan for syngnathia must include not only operation but also a rehabilitation programme (particularly muscle training)

Child, Preschool↗

PubMed2004

Concomitant reconstruction of mandibular basal and alveolar bone with a free fibular flap.

Repair of long-span mandibular defects with a free fibular flap is now a routine procedure. However, the bone height of the neo-mandible after reconstruction with a fibular flap is about half that of the dentulous mandible. When a fibular graft is placed only at the inferior border of the mandible, the resulting vertical discrepancy between the graft segment and the occlusal plane can adversely affect implant mechanics or denture stability and retention. To overcome these problems, we developed a technique for two-strut type mandibular reconstruction. A vascularized fibular segment is used to reconstruct the inferior basal portion of the neo-mandible, while a non-vascularized residual fibular segment is used to simulate the superior alveolar portion. We used this technique in 22 patients. Graft survival, graft resorption, and the ability to place implants were assessed as compared with those after the conventional one-strut type technique. The fibular segment grafted to the alveolar region was removed in one patient with intraoral wound dehiscence and in two with postoperative infection. All vascularized fibular flaps were successful. The resorption rate was 13.6+/-7.2% for non-vascularized segments and 3.0+/-3.7% for vascularized segments. Dental implants were placed in five of our 22 patients. The crown:fixture length ratio was improved to 1:1.7, as compared with a ratio of 1:1.21 with use of a conventional fibular flap. We conclude that our technique is very easy and safe and provides substantially improved lower-lip and cheek support and implant-prosthetic mechanics than conventional procedures for the repair of long-span mandibular defects.

Adult↗

PubMed2004

Potential of pranlukast and zafirlukast in the inhibition of human liver cytochrome P450 enzymes.

1. The potential of zafirlukast to inhibit several human cytochrome P450 enzymes is well known. However, pranlukast, a structural analogue of zafirlukast, has not been studied. Accordingly, the inhibitory potential of pranlukast was evaluated and compared with that of zafirlukast, a known CYP2C9 inhibitor, in in vitro microsomal incubation studies. 2. Both pranlukast and zafirlukast showed moderate inhibition of CYP2C9-catalysed tolbutamide 4-methylhydroxylation, competitively inhibiting tolbutamide 4-methylhydroxylation with estimated mean K(i) values of 3.82 +/- 0.50 and 5.86 +/- 0.08 microM, respectively. 3. Pranlukast had no effect on CYP2C19-catalysed S-mephenytoin 4'-hydroxylation or CYP3A4-catalysed midazolam 1-hydroxylation. However, zafirlukast showed minor inhibition of these reactions. Neither pranlukast nor zafirlukast inhibited CYP1A2-catalysed phenacetin O-deethylation, CYP2D6-catalysed dextromethorphan O-demethylation or CYP2E1-catalysed chlorzoxazone 6-hydroxylation. 4. The results suggest that like zafirlukast, pranlukast also has the potential moderately to inhibit CYP2C9-catalysed tolbutamide 4-methylhydroxylation. Therefore, the inhibitory potential of pranlukast should be considered when it is co-administered with CYP2C9 substrates with narrow therapeutic ranges (e.g. S-warfarin, phenytoin).

Aryl Hydrocarbon Hydroxylases↗

PubMed2004

Entropy and bispectral index during anaesthesia in children.

Entropy is a new EEG based technology developed as a measure of depth of anaesthesia. The Entropy algorithm quantifies the degree of disorder in the EEG. During anaesthesia the disorder of the EEG, or entropy, falls. Entropy is independent of absolute frequency or amplitude of the EEG. This may make it suitable for paediatric anaesthesia. In this prospective observational blinded study we recorded the Entropy and Bispectral Index in 23 children undergoing general anaesthesia with isoflurane and nitrous oxide, supplemented with peripheral nerve blockade. We recorded Entropy at several times during anaesthesia, pre-awakening and 1-minute post-awakening. Entropy pre-awakening and 1 minute after awakening was compared to a value during anaesthesia in three age groups; less than one-year-old (infants), one to five years (toddlers) and five to twelve years (children). The correlation between BIS and Entropy was also calculated. Entropy post-awakening was higher than during anaesthesia for all age groups. Entropy pre-awakening was higher than during anaesthesia for the children and toddlers. This was not as apparent in infants. There was a strong correlation between BIS and Entropy for children and toddlers. The correlation was less for infants. This study demonstrates that, in children, Entropy is lower during anaesthesia when compared to awake values. Further evaluation in the paediatric population is worthwhile.

Algorithms↗

PubMed2004

Dysplastic nodules in liver cirrhosis: detection with triple phase helical dynamic CT.

The purpose of this study was to determine the sensitivity of triple phase helical dynamic CT for detecting dysplastic nodules in patients with liver cirrhosis. 76 dysplastic nodules were confirmed by histopathological examination of the liver specimens after surgical resection in 21 patients or after explantation of the whole liver in 20 patients. Triple phase helical dynamic CT including arterial, portal venous and delayed phases was performed as a pre-operative evaluation for hepatocellular carcinoma. Two readers retrospectively evaluated the images. The presence of dysplastic nodules was determined by one-to-one correlation of the CT images and the pathological results in terms of the anatomical location and size of each nodule. Helical dynamic triple phase CT depicted eight of 76 dysplastic nodules (10%): five of 35 high grade dysplastic nodules (14%) and three of 41 low grade dysplastic nodules (7%). Triple phase helical dynamic CT is insensitive for detection of dysplastic nodules in cirrhotic livers.

Adult↗

PubMed2003

Primary clear cell sarcoma of bone.

Clear cell sarcoma is a rare soft tissue sarcoma of young adults with melanocytic differentiation. It occurs predominantly in the soft tissue of extremities, typically involving tendons and aponeuroses. Primary clear cell sarcoma of bone is extremely rare. We report a case of primary clear cell sarcoma of the right first metatarsal in a 48-year-old woman and provide a literature review of the entity.

Bone Neoplasms↗

PubMed2003

Idiopathic thrombocytopenic purpura: better therapeutic responses of patients with B- or T-cell clonality than patients without clonality.

Results of recent studies of the pathogenesis of idiopathic thrombocytopenic purpura (ITP) have suggested activated helper T-cells drive B-lymphocytes to produce antibodies. Twenty-eight children and 85 adults with ITP entered this study. We performed polymerase chain reaction (PCR) using framework III variable region (V(H) FRIII)- and joining region (J(H))-specific primers to analyze immunoglobulin heavy-chain gene rearrangement (IgH GR) for B-cell clonality. We used multiplex PCR to analyze T-cell receptor (TCR) gamma-chain gene rearrangement (TCRgamma GR) for T-cell clonality. We diagnosed 10 cases as acute ITP and 97 cases as chronic ITP. The IgH GR result was positive in 77.8% of the acute-form cases and in 58.8% of the chronic-form cases. The TCRgamma GR result was positive in 11.1% of the acute cases and in 10.6% of the chronic cases. There was no difference in frequency of clonality between the acute and chronic forms. After treatment the platelet count normalized in 81.8% (36/44) of the chronic ITP cases with B-cell clonality and in 88.9% (8/9) of the chronic ITP cases with T-cell clonality, compared with a normalized platelet count in 46.2% (12/26) of the chronic ITP cases without clonality. The patients with T- or B-cell clonality appeared to have better therapeutic responses than patients without clonality. In conclusion, T- and B-cell clonality may play a positive role in determining therapeutic response.

Adolescent↗

PubMed2003

Neuronal interactions are higher in the cortex than thalamus in the somatosensory pathway.

Previous studies have shown significant correlated discharges (noise correlation) and synergistic information coding among adjacent cortical neurons. In order to investigate whether such interactions are present at an earlier stage of sensory processing, we compared noise correlation and synergistic information transmission in the ventral posterolateral nucleus (VPLn) of thalamus and primary somatosensory cortex (SI) of anesthetized rats. A hind paw was stimulated electrically and responses of several neighboring neurons were recorded simultaneously with a tetrode. Analyses indicated that noise correlation in the SI was about four times higher than in the VPLn, and, interestingly, it was significantly reduced following sensory stimulation in both regions. Spike count distributions of individual VPLn units contained higher amounts of information about the delivery of external stimulation compared with those of SI units. When simultaneously recorded units were considered together, transmission of information was more interactive (synergistic or redundant) among SI than VPLn units. On average, information transmission was independent in the VPLn, but synergistic in the SI. The difference in synergistic information coding was largely attributable to different levels of noise correlation and their modulation by external sensory stimulation. These results indicate that neuronal interactions are relatively low at the thalamic level, but much enhanced at the cortical level along the somatosensory pathway. The enhanced neuronal interactions in the cortex may reflect the role of cortex in extracting higher features of sensory stimuli.

Action Potentials↗

PubMed2003

Long-term potentiation in visual cortical projections to the medial prefrontal cortex of the rat.

In order to investigate neural mechanisms by which the prefrontal cortex adaptively modifies its activities based on past experience, we examined whether or not sensory cortical projections to the medial prefrontal cortex support long-term potentiation (LTP) in rats. Monosynaptic projections from the secondary visual cortex, mediomedial area (V2MM) to the infralimbic cortex were confirmed by orthodromic as well as antidromic activation of single units. High-frequency stimulation (50 Hz, 2 s) induced LTP (approximately 45% increase over the baseline) in the V2MM projection to the infralimbic cortex. LTP induction in this pathway was completely blocked by an injection (i.p.) of CPP, an N-methyl-D-aspartate receptor antagonist. LTP was also induced in the ventral hippocampal projection to the infralimbic cortex by the same high-frequency stimulation. The present results suggest that modification of synaptic weights of afferent sensory cortical projections is one mechanism underlying learning-induced changes in prefrontal cortical neural activities.

Animals↗

PubMed2003

Intraspecific relationship analysis by DNA markers and in vitro cytotoxic and antioxidant activity in Eleutherococcus senticosus.

To analyse genetic relationships and intraspecific variation within Eleutherococcus senticosus, the polymerase chain reaction (PCR) was performed on total genomic DNAs of 10 Eleutherococcus collections. Ten primers were used for amplification, yielding 106 bands, of which 87 were polymorphic. The genetic diversity and genetic distance among 10 collections of Eleutherococcus species were used to describe the dendrogram showing the phylogenic relationship. The 10 collections were classified into two groups (groups I and II) at a similarity coefficient of 0.50. Group I included E. senticosus from Bukhaedo (Japan), E. sessliliflorus from Youngwal (Korea), E. seoulense and E. chiisanesis, while group II included several internal and Russian collections. The range of polymorphism was from 66.7 to 90.9% in the 87 amplified polymorphic DNA fragments. The similarity value of all collections ranged from 0.41 to 0.92, and the average genetic distance was 0.61. Thus, RAPD analysis was useful in determining genetic relatedness among collections and in identifying different genotypes of E. senticosus and other Eleutherococcus species. Also, the biological activity on DPPH radical scavenging, antilipid peroxidation in rat liver microsomes and cytotoxic sulforhodamine B (SRB) assay was evaluated using root extracts of E. senticosus, Odaesan, Korea. Ethyl acetate and n-butanol fractionation revealed strong antioxidant against scavenging on DPPH free radical and also ethyl acetate fractionation exhibited high antilipid peroxidative activities. In the cytotoxic effects were evaluated on seven human cancer cell lines, the values of 50% growth inhibition (GI(50)) were mostly below 30 microg/ml for crude extracts to be considered as significantly active.

Animals↗

PubMed2003

The effects of dual blockade of the renin-angiotensin system on urinary protein and transforming growth factor-beta excretion in 2 groups of patients with IgA and diabetic nephropathy.

AIMS: The therapeutic benefits of dual blockade of the renin-angiotensin system (RAS) have been inconsistent on renal function and proteinuria. To know the contribution of the heterogeneity of study subjects to such inconsistency, we evaluated the effects of dual blockade of RAS in 2 groups of selected renal diseases, IgA and diabetic nephropathy. To avoid confounding by the blood pressure-reducing effects, angiotensin II receptor antagonists (ATRAs) were added on the patients with long-term, optimally controlled blood pressure taking ACE inhibitors. Twenty-four-hour urinary protein excretion rate and urinary TGF-beta1 level were measured as surrogate markers of renal injury. METHODS: We conducted a prospective crossover trial with 14 IgA and 18 type-2-diabetic nephropathy patients showing moderate degree of proteinuria (> or = 1.0 g/day) and renal dysfunction (creatinine clearance 25 - 75/ml/min). Four to 8 mg once-daily dose of candesartan and placebo were alternatively added on ramipril dose of 5 - 7.5 mg/day for 16 weeks. RESULTS: All baseline data except for the age factor were statistically the same between the 2 disease groups. Twenty-four-hour mean arterial blood pressures were 91.2 +/- 1.6 and 92.3 +/- 1.8 mmHg in IgA and diabetic nephropathy patients respectively at baseline (p = NS). Mean arterial pressure did not change by the addition of candesartan or placebo in both groups. The addition of candesartan (combination) reduced 24-hour urinary protein excretion rate in IgA nephropathy patients with a mean change of -12.3 +/- 4.5%, which is significantly greater compared to a mean change of -0.1 +/- 3.3% after the addition of placebo (placebo) (mean difference 12.4 +/- 5.0, 95% CI 1.2 - 23.5; p < 0.05). Urinary TGF-beta1 level was reduced considerably by the combination therapy, with a -28.9 +/- 6.0% decrease, which was significantly different to that by the placebo, with +4.3 +/- 12.4% (33.3 +/- 13.5, 3.2 - 63.3; p < 0.05). In diabetic nephropathy patients, the addition of candesartan did not reduce 24-hour urinary protein excretion rate. Mean changes of 24-hour urinary protein excretion rate were -0.8 +/- 4.7% by the combination therapy and +0.5 +/- 6.1% by placebo (mean difference 1.3 +/- 4.7, 95% CI -6.8 - 13.5; p < NS). The level of urinary TGF-beta1 was reduced by the combination therapy, with -14.3 +/- 9.5% decrease, but it did not reach statistical significance compared to placebo of +0.7 +/- 15.5% (15.0 +/- 13.5, -14.4 - 44.5; p < NS). The changes in 24-hour urinary protein excretion rate and urinary TGF-beta1 level were neither correlated with each other, nor with the change in mean arterial pressure. Significant changes in the renal function were not detected during the study period. CONCLUSION: Definite beneficial effects of dual blockade of RAS on proteinuria and TGF-beta1 excretion were found in IgA nephropathy patients, which was independent of blood pressure-reducing effect. With our 16-week trial, such benefits were not observed in type 2 diabetic nephropathy. The reduction in urinary TGF-beta1 level suggests that the combination therapy may provide additional renoprotection through the antisclerosing effects. Based on our results, for a proper interpretation the therapeutic effects of the combination therapy should be evaluated separately according to the underlying renal disease.

Adult↗

PubMed2003

Age-related change in serum concentrations of testosterone in middle-aged Korean men.

The objective of this study was to determine whether testosterone and sex hormone binding globulin (SHBG) levels are different between healthy men and men with chronic illness, and to evaluate the age-related changes of testosterone and SHBG in healthy men in Korea. enrollment took place between January 2000 and December 2001 at Pundang CHA General Hospital in Korea. All men who came for male climacteric and geriatric health screening examinations were eligible. Of the 762 men recruited, 136 men had at least one present or previous medical illness and 626 men were healthy. Higher serum concentrations of total testosterone (5.31 +/- 1.88 ng/ml vs. 4.96 +/- 1.43 ng/ml; p < 0.05), free androgen index (16.60 +/- 7.36 vs. 14.57 +/- 5.55; p < 0.01) and calculated bioavailable testosterone (8.88 +/- 3.52 nmol/l vs. 7.91 +/- 2.52 nmol/l; p < 0.01) were demonstrated in the healthy compared with the disease group. Total testosterone declined at a rate of 0.2% per year, SHBG increased by 1.74% per year, calculated bioavailable testosterone declined by 0.8% per year, and free androgen index declined by 1.15% per year in healthy subjects aged between 40 and 70. The above results seem to be consistent with previous Western studies, showing higher concentrations of testosterone in healthy men, that decline with increasing age.

Adult↗

PubMed2002

Trimethyl[3-methyl-1-(o-tolenesulfonyl)indol-2-ylmethyl]ammonium iodide and benzyl[3-bromo-1-(phenylsulfonyl)indol-2-ylmethyl]tolylamine.

The title compounds, C(20)H(25)N(2)O(2)S(+).I(-), (I), and C(29)H(25)BrN(2)O(2)S, (II), respectively, both crystallize in space group P-1. The pyrrole ring subtends an angle with the sulfonyl group of 33.6 degrees in (I) and 21.5 degrees in (II). The phenyl ring of the sulfonyl substituent makes a dihedral angle with the best plane of the indole moiety of 81.6 degrees in (I) and 67.2 degrees in (II). The lengthening or shortening of the C-N bond distances in both compounds is due to the electron-withdrawing character of the phenylsulfonyl group. The S atoms are in distorted tetrahedral configurations. The molecular structures are stabilized by C-H.O and C-H.I interactions in (I), and by C-H.O and C-H.N interactions in (II).

Journal Article↗

PubMed2002

The skin barrier state of aged hairless mice in a dry environment.

BACKGROUND: Many elderly people have chronic xerosis, and frequently experience an exacerbation during winter. OBJECTIVES: To investigate the barrier state of aged murine skin with or without barrier disruption in a dry environment. METHODS: Aged and young hairless mice were kept separately in dry and normal conditions for 9 days. Acetone treatment was used to perturb the skin barrier. Skin barrier function was measured as transepidermal water loss (TEWL), and morphological changes in the epidermis were studied by electron microscopy. RESULTS: The baseline TEWL was not higher in the dry environment. The number of stratum corneum (SC) layers and the epidermal thickness of aged mice increased in the dry environment. The recovery rate of the aged skin barrier was neither accelerated nor delayed in the dry environment. In the normal environment, aged mice recovered more slowly than young mice. After barrier perturbation in the aged mice, changes in SC layers and in epidermal thickness were similar in the two environments. The secretion and number of lamellar bodies did not differ between the two environments. CONCLUSIONS: We confirmed that a dry environment induces epidermal proliferation and scaling in both aged and young mice. However, no remarkable difference was found in the skin barrier recovery of aged hairless mice in a dry environment.

Acetone↗

PubMed2002

A case of giant congenital nevocytic nevus with neurotization and onset of vitiligo.

The authors report the case of a 21-year-old woman with a giant congenital nevocytic nevus (GCNN) who developed vitiligo at the age of 16 years on skin areas remote from the GCNN. This is the first reported case of GCNN developing neurotization combined with vitiliginous changes within the GCNN lesion. Treatment with PUVA achieved repigmentation of the vitiligo lesions, except for the hypochromic areas within the area of the nevus that were shielded from UVA radiation.

Adult↗

PubMed2002

Analysis of errors in medical rapid prototyping models.

Rapid prototyping (RP) is a relatively new technology that produces physical models by selectively solidifying UV-sensitive liquid resin using a laser beam. The technology has gained a great amount of attention, particularly in oral and maxillofacial surgery. An important issue in RP applications in this field is how to obtain RP models of the required accuracy. We investigated errors generated during the production of medical RP models, and identified the factors that caused dimensional errors in each production phase. The errors were mainly due to the volume-averaging effect, threshold value, and difficulty in the exact replication of landmark locations. We made 16 linear measurements on a dry skull, a replicated three-dimensional (3-D) visual (STL) model, and an RP model. The results showed that the absolute mean deviation between the original dry skull and the RP model over the 16 linear measurements was 0.62 +/- 0.35 mm (0.56 +/- 0.39%), which is smaller than values reported in previous studies. A major emphasis is placed on the dumb-bell effect. Classifying measurements as internal and external measurements, we observed that the effect of an inadequate threshold value differs with the type of measurement.

Algorithms↗