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Biomedical subjects

J Kim

Publications and source records attributed to J Kim.

At least 1,261 records · Page 70Linked to original sources
PubMedDate not supplied

Crescent sign in invasive pulmonary aspergillosis: frequency and related CT and clinical factors.

PURPOSE: The aim of our study was to evaluate the frequency of the crescent sign on follow-up radiographs in patients with invasive pulmonary aspergillosis, correlated with initial CT and clinical findings. METHOD: Retrospective analysis of serial chest radiographs was performed to see the frequency of the crescent sign in 21 consecutive patients with pathologically proved invasive pulmonary aspergillosis. The appearance of the crescent sign was correlated with the pattern of parenchymal lesions on initial CT scans, the presence and duration of neutropenia, and underlying diseases. RESULTS: The crescent sign was seen in 10 of 21 patients (48%) on follow-up radiographic examinations. It was seen in patients with initially large [consolidation or mass; 9/11 (82%) patients] rather than small [nodule(s); 1/10 (10%) patients] parenchymal lesions (p = 0.002) on CT. The sign appeared in 7 of 17 (41%) patients with neutropenia 1-10 days after recovery from neutropenia. It appeared in three of four patients (75%) without neutropenia 4--8 days after treatment with amphotericin B. The appearance was not related to the duration (32 days in patients with crescent sign and 17 days without sign) of the neutropenic period (p > 0.05). The sign was seen in 8 of 15 (53%) patients with acute myelogenous leukemia and 2 of 6 (33%) patients with other diseases (p > 0.05). CONCLUSION: The crescent sign appears in about half of patients with invasive pulmonary aspergillosis with recovery from neutropenia, especially when the initial lesion is a consolidation or mass on CT scans.

Adolescent↗
PubMedDate not supplied

Morphological patterns of seizures recorded intracranially.

We analyzed the frequency and morphological characteristics of the initial EEG manifestations of spontaneous seizures recorded from depth and subdural electrodes in 26 patients for whom pathological analysis of the area of seizure onset was available after resective surgery. Pathological features considered to be positive findings included well-defined structural lesions (hamartoma, neoplasm) or strictly defined mesial temporal sclerosis. Seizure onset was characterized by the frequency of the rhythmic discharge greater than 2 Hz in the first second and by the presence or absence of periodic low-frequency spikes (less than 2 Hz) preceding this stable change in background frequency. These features were correlated with the presence or absence of pathologic abnormalities in temporal and extratemporal locations. Although all patterns and frequencies of seizure onset were recorded in both medial temporal and extratemporal locations, medial temporal seizure onset was significantly more likely to have high frequency (greater than 13 Hz, p less than 0.00001) and tended to show periodic spikes prior to the seizure when it was associated with medial temporal sclerosis compared to when it was not. Extratemporal seizure onset associated with abnormal pathological substrate was significantly more likely to have a lower frequency (less than 13 Hz, p less than 0.05) and no periodic spikes before seizure onset (p less than 0.00001) than extratemporal seizure onset recorded from areas without pathological findings. Variability of seizure onset frequency was a characteristic of temporal, but not extratemporal, seizures (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Brain Diseases↗
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Anatomic correlates of interhippocampal seizure propagation time.

The relation between interhippocampal seizure propagation time (IHSPT) and anatomic alterations in the human epileptic hippocampus may provide insight into the pathophysiology of temporal lobe epilepsy (TLE). Using depth electrode recordings, we measured the time required for spontaneous seizures with onset in one hippocampus to become manifest in the contralateral hippocampus in 50 patients who underwent resection of the temporal lobe of seizure origin. Cell densities in individual hippocampal subfields were determined and correlated with mean IHSPT for each patient. Mean IHSPT was significantly and inversely correlated with cell counts in CA4 only (r = -0.38, p less than 0.01, Pearson's product correlation; r = -0.52, p less than 0.001, Spearman's rank order correlation). In 5 patients with bilateral independent hippocampal seizure onset who had temporal lobectomy and a diagnosis of mesial temporal sclerosis, mean IHSPT was consistently longer from the sclerotic temporal lobe than to it. These observations suggest that anatomic changes associated with chronic epilepsy alter propagation patterns. Because CA4 is believed to modulate the output of dentate granule cells and also has commissural connections to the contralateral homotopic area, the association of decreased CA4 cells with prolongation of IHSPT suggests that the observed anatomic alterations may actively (through increased inhibition) or passively (through decreased recruitment) interfere with various routes of seizure propagation.

Cell Count↗
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Oral supplementation of L-arginine prevents chronic cyclosporine nephrotoxicity in rats.

This study was performed to evaluate the effect of L-arginine (L-Arg) on the prevention of chronic cyclosporine (CsA) nephrotoxicity in rats. Rats pair-fed a low-salt diet (0.05%) were given CsA (15 mg/kg/day s.c.), CsA and L-Arg (L-Arg group, 1.25 g/l water), CsA and N-nitro-L-arginine methyl ester (L-NAME group, 70 mg/l water) or vehicle. After 28 days, the L-Arg group had a higher glomerular filtration rate compared to the CsA (0.42 +/- 0.05 vs. 0.31 +/- 0.06 ml/min/100 g, p < 0.05) and the L-NAME groups (vs. 0.19 +/- 0.04 ml/min/100 g, p < 0.05) and a significantly lower serum creatinine level compared to the CsA (0.70 +/- 0.06 vs. 0.92 +/- 0.12 mg/dl, p < 0.05) and the L-NAME groups (vs. 1.21 +/- 0.17 mg/dl, p < 0.05). The L-Arg group had less fibrosis, tubular injury (TI), and arteriolopathy than the CsA (fibrosis 0.39 +/- 0.14 vs. 0.74 +/- 0.15; TI 1.3 +/- 0.3 vs. 2.0 +/- 0.1; arteriolopathy 33 +/- 7 vs. 48 +/- 17, p < 0.05, respectively) and the L-NAME groups (fibrosis vs. 1.67 +/- 0.32, TI vs. 2.6 +/- 0.3, arteriolopathy vs. 63 +/- 10, p < 0.05, respectively). Plasma renin activity in the L-Arg group was less than in the CsA (18 +/- 2 vs. 23 +/- 3 ng Ang I/ml/h, p < 0.05) and the L-NAME groups (vs. 30 +/- 3 ng Ang I/ml/h, p < 0.05). Nitric oxide production in L-Arg group was higher than in the CsA (24.2 +/- 1.7 vs. 11.1 +/- 1.5 mumol/24 h, p < 0.05) and the L-NAME groups (vs. 8.4 +/- 1.0 mumol/24 h, p < 0.05). In conclusion, the nitric oxide pathway is associated with the pathogenesis of chronic CsA nephrotoxicity, and exogenous L-Arg supplementation is effective in reducing chronic CsA nephrotoxicity in rats.

Animals↗
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TPH gene may be associated with suicidal behavior, but not with schizophrenia in the Korean population.

Tryptophan hydroxylase (TPH) is a rate-limiting enzyme in the biosynthesis of serotonin. This study was designed to examine whether A218C polymorphism, which has been identified in intron 7 of the TPH gene, may be associated with schizophrenia or the suicidal behavior of schizophrenics in the Korean population. TPH genotypes were determined in DNA samples from 217 schizophrenics and 236 healthy volunteers. Among the schizophrenic group, 27 patients had a history of suicidal behavior. Genomic DNA was amplified by a polymerase-chain-reaction-based method and restricted by Nhel. A218C polymorphism was associated with a history of suicidal behavior in schizophrenics. This finding suggests that the TPH gene or a gene in its vicinity may influence suicidal behavior in schizophrenics. However, genotypic and allelic distrubutions of this polymorphism did not significantly differ between schizophrenics and controls.

Adult↗
PubMedDate not supplied

Behavior of murine renal carcinoma cells grown in ectopic or orthotopic sites in syngeneic mice.

We examined whether the organ microenvironment modulates the metastatic behavior and the response to doxorubicin (DXR) in murine renal carcinoma (RENCA) cells. Tumor cells were injected into kidney (orthotopic) and subcutis (ectopic) of syngeneic mice. Lung metastases developed in up to 57% (17/30) of animals having kidney tumors but not in those with skin tumors. Tumors growing in the kidney were more resistant to DXR than tumors growing in the subcutis when mice were given intravenous injections of DXR (8 mg/kg) on days 8 and 15 after implantation. In addition, tumor cells cultured from kidney tumors were initially more resistant to DXR than tumor cells cultured from subcutis tumors. After tumor cells were passaged in vitro, all cells exhibited a similar sensitivity to DXR. Additionally, we examined the expression levels of mdr1, EGFR and type IV collagenase by an in situ mRNA hybridization technique. A higher mRNA expression for type IV collagenase and EGFR was found in kidney tumors than in subcutis tumors. These results demonstrate that the organ environment influences the drug responsiveness and the expression of metastasis-related genes in murine renal carcinoma cells.

Animals↗
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Protective effects of (-)-epigallocatechin-3-gallate on UVA- and UVB-induced skin damage.

It has been known that green tea and its components possess significant chemopreventive effects against chemical carcinogens and photo-caused skin tumor formation. In this study, the protective effects of (-)-epigallocatechin-3-gallate (EGCG), a major green tea catechin, on the ultraviolet (UV)-induced skin damage (photoaging) were studied in guinea pigs, hairless mice and human dermal fibroblast cultures. The lipid peroxidation was significantly reduced in the EGCG-treated group. The amount of lipid peroxides produced in the control and EGCG treated group were 838 +/- 144 and 286 +/- 57 nmol/mg at 18 h after UV irradiation, respectively. UVB-induced erythema was also significantly reduced in the EGCG treated group. The erythema relative index of the control and the EGCG treated group were 311 +/- 45 and 191 +/- 49 at 16 h after UV irradiation, respectively. EGCG treatment reduced UVA-induced skin damage (roughness and sagginess) and protected from the decrease of dermal collagen in hairless mouse skin. EGCG treatment blocked the UV-induced increase of collagen secretion and collagenase mRNA level in fibroblast culture. The nuclear transcription factors NF-kappaB and AP-1 binding activities were also inhibited by EGCG treatment.

Animals↗
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Prognostic evaluation of curatively resected locally advanced gastric cancer patients with preoperative downstaging chemotherapy assessed by histochemical and pharmacologic means.

The aim of the present study was to investigate whether the rate of thymidylate synthetase inhibition (TSIR) and the rate of proliferating cell nuclear antigen expression (PCNA-R) in gastric cancer tissues, which can be obtained within a short period after surgery, were predictive and quantitative prognostic factors for locally advanced gastric cancer patients with preoperative down-staging chemotherapy. Curatively resected 30 locally advanced gastric cancer patients with preoperative chemotherapies were studied. Three-year survival analysis showed that the higher TSIR and the lower PCNA-R significantly predicted better prognosis (p < 0.01 and p < 0.05, respectively). Multiple regression test showed that the TSIR was a significantly predictive variable for 1-year survival (p < 0.05). The TSIR and PCNA-R could be predictive and quantitative prognostic factors in advanced gastric cancer patients who received preoperative downstaging chemotherapy.

Antineoplastic Agents↗
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Mobility of carbon nanotubes in high electric fields.

The influence of electric fields on carbon nanotubes is experimentally demonstrated. Alignment of nanotubes along field lines, directed motion of nanotubes between electrodes separated by several thousand micrometers, and impressive solid-state actuation behavior of nanotube-embedded structures are demonstrated, taking into account the polarization and charging of the nanotubes. These effects are reported for long strands of nanotubes, nanotubes dispersed on substrates, and nanotube-embedded polymer strips. The relative magnitude of the field responsible for polarization and directed motion was found to be dependent on the morphology of the nanotubes used. These observations may foreshadow novel electromechanical applications for nanotube elements.

Electrochemistry↗
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Extracellular water: sodium bromide dilution estimates compared with other markers in patients with acquired immunodeficiency syndrome.

Extracellular fluid and closely related extracellular water (ECW) provide information on nutritional status in health and disease. Although various methods exist for ECW determination, little is known about their comparability in patients with wasting diseases such as acquired immunodeficiency syndrome (AIDS). One practical method, the dilution of sodium bromide (NaBr), is used widely in clinical research, although its relationship to other ECW markers has not been well characterized. The present study sought to compare ECW estimates as determined by NaBr and three other methods in 11 male patients with AIDS (mean +/- SD; age, 44+/-12 years; body weight, 64.5+/-8.8 kg; and height, 172+/-4 cm). ECW volumes were determined from NaBr dilution, total body chlorine (TBCl) by delayed gamma-neutron activation analysis, total body water (TBW) by tritium dilution combined with total body potassium (TBK) by whole body 40K counting, and radioactive sulfate dilution (35SO4). All correlations between the NaBr method and other methods were statistically significant (NaBr vs TBCl [r = .91; p < .001]; vs TBW/TBK [r = .76; p < .01]; and vs 35SO4 [r = .89; p < .001]). As expected from previous studies, ECW (L) derived by NaBr provided a group mean (15.1+/-2.2 L) similar to the TBCl method (15.4+/-1.7 L; p = .32), a significantly smaller ECW than by the TBW/TBK method (18.6+/-3.4 L; p = .0004), and a significantly larger ECW than by 35SO4 method (13.3+/-3.0 L; p = .002). Estimating ECW by NaBr dilution was comparable with other research-based ECW methods and, thus, offers a practical alternative for evaluating ECW in patients with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Cardiac arrest due to a vagal reflex potentiated by thoracic epidural analgesia.

Reflex bradycardia and cardiac arrest may be the result of a vagal reflex, which can occur during a variety of surgical procedures. We report a patient who developed cardiac arrest as a result of a vagal reflex that was potentiated by thoracic epidural analgesia during general anaesthesia. A 53-year-old man was scheduled for subtotal gastrectomy because of an early gastric adenocarcinoma. After an epidural catheter had been inserted, general anaesthesia was induced. During surgery, an abdominal self-retaining retractor was set up but bradycardia and cardiac arrest developed. The patient returned to a normal sinus rhythm after successful resuscitation. We conclude that bradycardia as a result of a vagal reflex is mediated by potent abdominal wall traction and is potentiated by epidural analgesia. Early diagnosis and proper treatment can allow a full recovery, even in high-risk patients.

Abdomen↗
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The maximum permissible ambient noise and frequency-specific averaging time on the measurement of distortion product otoacoustic emissions.

The effects of ambient noise and averaging time on distortion product otoacoustic emission (DPOAE) measurements were systematically examined in 20 normally hearing adults. For each frequency from 0.7 to 6 kHz, 2f1-f2 DPOAEs were measured at nine intensity levels of ambient noise for each of four different averaging times. The dependent variable of interest was the DPOAE:noise ratio (D:N)--the relationship between DPOAE amplitude and noise level at 2f1-f2. Findings indicated that, relative to the baseline condition (25 dBA), ambient noise levels of 40 dBA or greater affected the D:N considerably in the lower frequencies. However, noise levels of 55-65 dBA did not affect the D:N in the higher frequencies. Results also indicated that, to achieve detectable DPOAEs, longer averaging times were required as ambient noise increased and as frequency decreased. Based on the results, the maximum permissible ambient noise levels (MPANLs) were estimated in relation to averaging time.

Acoustic Stimulation↗
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Does the binding of clusters of basic residues to acidic lipids induce domain formation in membranes?

Several proteins that are important components of the calcium/phospholipid second messenger system (e.g. phospholipase C, protein kinase C, myristoylated alanine-rich C kinase substrate (MARCKS) and pp60src) contain clusters of basic residues that can interact with acidic lipids on the cytoplasmic surface of plasma membranes. We have studied the membrane binding of MARCKS and pp60src, peptides that mimic the basic regions of these proteins, and simple model peptides. Specifically, we determined how the binding of these model peptides depends on (1) the number of basic residues in the peptide (2) the fraction of acidic lipids in the membrane (3) the ionic strength of the solution (4) the chemical nature of the basic residues (Arg versus Lys) and the acidic phospholipids [phosphatidylglycerol (PG) versus phosphatidylserine (PS)] (5) the pressure and (6) the temperature. The results are consistent with a simple theoretical model: each basic residue in a peptide binds independently to an acidic lipid with an intrinsic microscopic association constant of 1-10 M-1 (binding energy congruent to 1 kcal/mol). The binding is described with a mass action formalism and the non-specific electrostatic accumulation of the peptides in the aqueous diffuse double layer is described with the Gouy-Chapman theory. This Gouy-Chapman/mass action model accounts surprisingly well for the sigmoidal dependence of binding on the percentage of acidic lipids in the membrane (apparent co-operativity or Hill coefficient > 1); the model assumes that the multivalent basic peptides bind > 1 acidic lipids and thus induce or stabilize domain formation.

Amino Acid Sequence↗
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Enhancement of gene transfer efficiency into human cancer cells by modification of retroviral vectors and addition of chemicals.

Retroviral vectors have recently experienced limited use in cancer gene therapy mainly due to poor transduction efficiency. To overcome this drawback, we attempted to enhance the transduction efficiency by employing different retroviral packaging cell lines and chemical additives. The retrovirus from the PG13 packaging cell line gave mostly higher or similar transduction efficiencies in a variety of human cancer cell lines compared to the retrovirus from the PA317, Bing, or FLYRD18 packaging cell line. A cationic liposome, especially Lipofectamine, significantly enhanced the transduction efficiency of a retrovirus. However, the retrovirus derived from the PG13 cell line could not infect the murine cell line efficiently even after Lipofectamine treatment. Furthermore, chloroquine did not improve the transduction efficiency regardless of the presence of chemical additives. These results, therefore, suggested that the transduction efficiency of a retrovirus in human cancer cells can certainly be improved when a proper packaging cell line is chosen. In addition, this study implied that Lipofectamine is a superb additive to enhance the transduction efficiency of a retrovirus via a specific virus envelope protein-receptor interaction for virus entry, and that receptor-mediated endocytosis does not seem to be the leading route of virus delivery to liberate a virus genome.

3T3 Cells↗
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Tolerance of patients and postoperative results: topical anesthesia for strabismus surgery.

PURPOSE: To assess patient tolerance and the postoperative results of intraoperative adjustment of strabismus surgery under topical anesthesia. METHODS: Twenty-four patients with strabismus underwent rectus muscle recession under topical anesthesia without the use of additional systemic analgesics and sedatives. Patient tolerance was estimated according to the sites of procedure. In addition, the angle of strabismus was measured 1 day, 6 weeks, and 1 year postoperatively. RESULTS: Of the 24 patients identified (11 men and 13 women; mean age: 24 years), 16 had exotropia, 7 were esotropic, and 1 was hypertropic. During the operation, 17 patients never expressed any pain, and 7 patients complained of discomfort on muscle manipulation. Postoperatively, the success rate was 95.8% (23 patients) the first day after surgery, 79.2% (19 patients) after 6 weeks, and 70.8% (17 patients) after 1 year. CONCLUSION: Intraoperative adjustment performed with the patient under topical anesthesia is recommended in all cooperative cases of strabismus surgery and is comfortable for patients.

Adolescent↗
PubMedDate not supplied

Hyperinsulinemic hypoglycemia associated with possible hypopituitarism in a patient with acquired immunodeficiency syndrome.

OBJECTIVE: To describe endocrine dysfunctions associated with human immunodeficiency virus (HIV) infection. METHODS: We present a case report, discuss the laboratory findings, and suggest potential contributing factors in this complex milieu. RESULTS: A 44-year-old man infected with HIV was admitted with loss of consciousness after a grand mal seizure and was found to have a prolonged course of hypoglycemia in conjunction with increased serum levels of insulin and C peptide. Iatrogenic hypoglycemia was excluded by laboratory evaluations. Hypothalamic-pituitary dysfunction was suspected because the serum growth hormone and cortisol concentrations during hypoglycemia were low. Radiologic evaluation of the brain revealed no structural abnormalities involving the hypothalamic-pituitary area. A normal cortisol response to adrenocorticotropic hormone stimulation (cosyntropin, 250 mg) was documented on two occasions. The cause of the severe hypoglycemic episode and the possible hypothalamic-pituitary-adrenal axis dysfunction in this patient is unknown. CONCLUSION: Despite the complexity of endocrine disorders in HIV-infected patients, the course of the disease in this patient underscores the possibility that some of the endocrinologic changes may be reversible.

Acquired Immunodeficiency Syndrome↗