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Biomedical subjects

J H Song

Publications and source records attributed to J H Song.

124 records · Page 7Linked to original sources
PubMed1994

Detection of the H1-j strain of Salmonella typhi among Korean isolates by the polymerase chain reaction.

Salmonella typhi, the etiologic agent of typhoid fever, typically has only a phase-1 flagellar antigen, H1-d (fliC). While most strains of S. typhi have H1-d antigen, 10-20% of Indonesian isolates have been reported to possess H1-j antigen instead. To investigate the presence H1-j strains of S. typhi isolates in Korea, where typhoid fever is still a common infectious problem, we used the polymerase chain reaction (PCR) with a pair of oligonucleotides primers that specifically amplified the flagellin gene of S. typhi. Of 375 isolates of S. typhi tested, only one was shown to possess the H1-j antigen, which was shown by the presence of a 1,269-basepair fragment on agarose gel electrophoresis after the PCR. The isolate with the H1-j antigen was cultured from a Korean-Indonesian man who was already symptomatic in Indonesia and was thought to be an Indonesian strain. Because 375 strains tested in this study were collected from cases with typhoid fever in different regions of Korea during the period from 1986 to 1991, it could be concluded that the mutation rate to j antigen is negligible among S. typhi endemic in Korea.

Antigens, Bacterial↗
PubMed1993

Detection of Salmonella typhi in the blood of patients with typhoid fever by polymerase chain reaction.

A polymerase chain reaction (PCR)-based test was developed for the detection of Salmonella typhi in the blood specimens from patients with typhoid fever. Two pairs of oligonucleotide primers were designed to amplify a 343-bp fragment of the flagellin gene of S. typhi. Amplified products were analyzed by agarose gel electrophoresis and Southern blot hybridization by using a 32P-labeled 40-base probe internal to the amplified DNA. The nested PCR with two pairs of primers could detect 10 organisms of S. typhi as determined by serial dilutions of DNA from S. typhi. The peripheral mononuclear cells from 11 of 12 patients with typhoid fever confirmed by blood culture were positive for DNA fragment of the flagellin gene of S. typhi, whereas 10 blood specimens of patients with other febrile diseases were negative. With the nested PCR, S. typhi DNAs were detected from blood specimens of four patients with suspected typhoid fever on the basis of clinical features but with negative cultures. We suggest that the PCR technique could be used as a novel diagnostic method of typhoid fever, particularly in culture-negative cases.

Bacteremia↗
PubMed1992

Nosocomial pneumonia in medico-surgical intensive care unit.

Cases of hospital acquired pneumonia occurring during the 1st 12 months of Medico-Surgical ICU (Intensive care unit, MSICU) in operation were evaluated retrospectively to determine its incidence, common causative pathogens, outcome and radiological patterns with the new hospital setting providing a unique relatively aseptic environment. Among the 920 admitted patients, 73 episodes of nosocomial pneumonia on 63 patients were identified and the incidence rate was 7%. The most common pathogens were Pseudomonas. Staphylococcus, Serratia, and Enterobacter in the order of frequency of occurrence, and the gram-negative pathogens comprised 70%. Nosocomial pneumonia was more common after use of antibiotics due to such pathogens as Enterobacter, Acinetobacter, and Candida which caused poor outcome. Enterobacter had the greatest tendency to be related with poor outcome and Serratia the least. Overall mortality was 25%. Bronchopneumonia was the most common type of pneumonia caused by any pathogen except Acinetobacter which caused a mixed type of nosocomial pneumonia.

Cross Infection↗
PubMed1990

Electric fields induced by low frequency magnetic fields in inhomogeneous biological structures that are surrounded by an electric insulator.

Electric fields induced by low-frequency magnetic fields into inhomogeneous structures, which have electric conductivities and dielectric permittivities of typical biological substances, are evaluated. Closed-form approximate and numerical solutions are obtained for nonconcentric cylinders with different electric properties (such as bone embedded in muscle), which are surrounded by a good electrical insulator (such as air). It is shown that even a single inhomogeneity in an otherwise homogenous cylinder, which is exposed to a uniform, axially directed magnetic field, can lead to substantial deviations from the direction and distribution of the induced electric field that would exist in the homogenous cylinder. Thus the induced field is not everywhere circumferential, nor does it magnitude at all angular positions increase linearly with the radial distance. Radially and circumferentially directed field components depend on size, electrical properties, and eccentricity of the inhomogeneities. Equations as well as graphical presentations are given that describe the induced fields when the enclosed inhomogeneities consist either of eccentrically located single cylinders or pairs of coaxial cylinders with different electrical conductivities or dielectric permittivities.

Electric Conductivity↗
PubMed1989

[An electric T test topographic map study of the brain in uremia].

This paper reports the results of statistical mapping on cerebral electric power abnormal distributions in 35 cases of uremia, using cerebral electrical T test topographical map method. The results indicated that the abnormal wide distribution of cerebro-electric activity of uremia was significant (P less than 0.01). The power density of slow wave markedly increased in the right parietal region. The power density of alpha wave obviously decreased in the right parietal side. This study clearly showed that the brain lesions have both the generality of diffuse damage and the particularity of focal damage. A region was seriously invaded by the lesion. The brain lesions have metabolic and toxic encephalopathic features.

Adult↗
PubMedDate not supplied

Cholecysto-urachal fistula.

The urachus is an embryonic remnant that connects the primitive bladder to the allantois. Multiple urachal anomalies have been described, including the urachal sinus, urachal cyst, patent urachus, and urachal diverticulum. We describe an unusual case in which a patient with urinary tract infection and dysuria was ultimately found to have urinary gallstones from a urachal connection with the gallbladder.

Aged↗
PubMedDate not supplied

Percutaneous biopsy in diffuse renal disease: comparison of 18- and 14-gauge automated biopsy devices.

PURPOSE: To compare 18-gauge-needle automated biopsy guns to 14-gauge systems for diagnostic efficacy and safety in percutaneous renal biopsy. MATERIALS AND METHODS: One hundred sixty-one computed tomographic (CT) guided biopsies for diffuse renal disease were retrospectively reviewed. An automated biopsy gun with an 18-gauge needle was used in 74 procedures, and a 14-gauge needle was used in 87 cases. RESULTS: Adequate tissue for histologic diagnosis was obtained in 96% (71 of 74) of cases with use of the 18-gauge needle, compared with 99% (86 of 87) in the 14-gauge group. The mean glomeruli per specimen were 10.7 and 13.7, respectively. Major hemorrhagic complications occurred in two cases (2.7%) of the 18-gauge group and in three cases (3.4%) of the 14-gauge group. CONCLUSION: The use of a biopsy gun with an 18-gauge needle provides high tissue recovery rate, comparable to that with the 14-gauge system. The complication rate was acceptably low, with no statistically significant difference from the 14-gauge needles (P = .80).

Adolescent↗
PubMedDate not supplied

Cytomegalovirus pneumonia: high-resolution CT findings in ten non-AIDS immunocompromised patients.

OBJECTIVE: To describe the HRCT findings of cytomegalovirus (CMV) pneumonia in non-AIDS immunocompromised patients MATERIALS AND METHODS: This retrospective study involved the ten all non-AIDS immunocompromised patients with biopsy-proven CMV pneumonia and without other pulmonary infection encountered at our Medical Center between January 1997 and May 1999. HRCT scans were retrospectively analysed by two chest radiologists and decisions regarding the findings were reached by consensus. RESULTS: The most frequent CT pattern was ground-glass opacity, seen in all patients, with bilateral patchy (n = 8) and diffuse (n = 2) distribution. Other findings included poorly-defined small nodules (n = 9) and consolidation (n = 7). There was no zonal predominance. The small nodules, bilateral in eight cases and unilateral in one, were all located in the centrilobular region. Consolidation (n = 7), with patchy distribution, was bilateral in five of seven patients (71%). Pleural effusion and bilateral areas of thickened interlobular septa were seen in six patients (60%). CONCLUSION: CMV pneumonia in non-AIDS immunocompromised patients appears on HRCT scans as bilateral mixed areas of ground-glass opacity, poorly defined centrilobular small nodules, and consolidation. Interlobular septal thickening and pleural effusion are frequently associated.

Cytomegalovirus Infections↗
PubMedDate not supplied

Measurement of fluid shift in CAPD patients using segmental bioelectrical impedance analysis.

OBJECTIVE: To determine, using segmental bioelectrical impedance analysis (BIA), the characteristics of fluid shift of each body segment in continuous ambulatory peritoneal dialysis (CAPD) patients during and after peritoneal dialysis (PD) solution exchange. DESIGN: Observational study with repeated measurements of bioelectrical impedance, which is inversely related to tissue fluid content. PATIENTS: Thirteen clinically stable CAPD patients. METHODS: Bioelectrical impedance was measured at frequencies of 5, 50, 250, and 500 kHz in each body segment four times: (1) before and (2) after drainage of dialysate, and (3) at 1 hour and (4) at 2 hours after exchange of new 1.5% dextrose PD solution. RESULTS: Impedance of both arms was significantly increased at 1 hour post exchange at all frequencies. In the trunk, impedance at all frequencies increased significantly after drainage, decreased significantly at 1 hour post exchange, and then increased again for the next hour without significance. Impedance of both legs showed a decreasing tendency at all frequencies during and after exchange. Net calculated water volume changes between the time before drainage and 2 hours post exchange were -0.5 L in the trunk, -0.25 L in both arms, +0.47 L in both legs, -0.28 L in total. The change in body weight between the time before drainage and 2 hours post exchange was -0.21 kg, on average, and significantly correlated with total net calculated water volume change (p = 0.009). CONCLUSIONS: Each body segment of the CAPD patient has its own characteristic pattern of fluid shift in response to PD solution exchange or dwell. Segmental BIA may be a useful tool for understanding the physiological changes in fluid shift in CAPD patients.

Adult↗
PubMedDate not supplied

Clinical outcomes of immediate full-volume exchange one year after peritoneal catheter implantation for CAPD.

OBJECTIVE: To evaluate actual risk of complications and 1-year catheter survival of immediate full-volume 2000-mL dialysate exchange after peritoneal catheter implantation. DESIGN AND SETTING: A prospective randomized comparative study in a university hospital kidney center. PATIENTS: The study included 59 end-stage renal disease patients entering into a continuous ambulatory peritoneal dialysis program between January 1996 and December 1997. INTERVENTIONS: In group 1 (n = 21), exchange volume was gradually increased from 500 mL per 3 hours to full-volume exchange over 13 days. In group 2 (n = 38), full-volume exchange per 6 hours was performed from the day of catheter implantation. Bed rest with minimal activity was recommended for the first 3 days in both groups. MAIN OUTCOME MEASURES: Occurrence of catheter-related complications such as dialysate leakage, drainage failure, malposition, infectious complications, and, ultimately, catheter loss were observed for 1 year. RESULTS: After straight Tenckhoff catheter implantation, pericatheter dialysate leaks occurred in 9.5% of group 1 and in 10.5% of group 2 patients (no significance, NS). Within 1 month of implantation, the incidences of tunnel or exit-site infection, catheter malposition, and outflow failure were not significantly different between the two groups. Abdominal discomfort was noted in 2 patients from group 2. Peritonitis occurred in 9.5% and 5.3% (NS) within 2 weeks of catheter implantation, and in 14.3% and 10.5% (NS) after more than 2 weeks in group 1 and group 2, respectively. Early catheter loss within 1 month occurred in 4.8% of patients in group 1 and 5.3% in group 2 (NS). The causes of loss were persistent leakage in group 1, and persistent leakage combined with tunnel infection and outflow failure in group 2. The duration of hospitalization from the day of catheter insertion to discharge was definitely shorter in group 2 compared to group 1 (9.9 +/-0.6 days vs 15.0 +/- 0.8 days, p < 0.001). For 1-year follow-up, the frequencies of peritonitis were 0.062 +/- 0.015/patient-month in group 1 and 0.076 +/- 0.018/patient-month in group 2 (NS). The actual 1-year catheter survival was 85.7% in group 1 and 84.2% in group 2 (NS). CONCLUSIONS: One-year catheter survival after immediate full-volume peritoneal dialysis exchange was 84.2%. This study did not show any evidence that immediate full-volume exchange causes more short- or long-term complications compared to the stepwise volume increment method.

Catheterization↗
PubMedDate not supplied

Ion channels as targets for insecticides.

Most insecticides are neurotoxicants causing various forms of hyperexcitation and paralysis in animals. A variety of neuroreceptors and ion channels have been identified as the major target sites of these neurotoxic insecticides. This paper gives the highlights of some of the recent development in this area. Pyrethroids keep the sodium channel open for unusually long times causing a prolonged flow of sodium current. The prolonged sodium current elevates and prolongs the depolarizing after-potential which reaches the threshold membrane potential to initiate repetitive after-discharges. We have developed the method with which the percentage of sodium channel population that needs to be modified to cause repetitive after-discharges can be measured accurately. In rat cerebellar Purkinje neurons, only 0.6% of sodium channels needs to be modified for hyperexcitation resulting in a large toxicity amplification. This concept is applicable to other neuroactive drugs that act through the threshold phenomenon. The mechanisms of selective toxicity of pyrethroids in mammals and insects have been quantitatively determined to be due mainly to the different sensitivity of the sodium channels to pyrethroids and the negative temperature dependence of pyrethroid action on the sodium channels. The degradation of pyrethroids play only a minor role. The negative temperature dependence of pyrethroid action is due to the increased sodium current flow at low temperature. The major site of action of dieldrin and hexachlorocyclohexane is the GABA(A) receptor chloride channel complex. Dieldrin exerts a dual action, initial stimulation and subsequent suppression, and the latter is responsible for hyperexcitation of animals. Dieldrin stimulation requires the gamma2s subunit in the GABA receptor, whereas dieldrin suppression occurs in the presence or absence of the gamma2s subunit.

Animals↗