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Biomedical subjects

K Jung

Publications and source records attributed to K Jung.

At least 55 records · Page 3Linked to original sources
PubMed2002

Tissue inhibitors of metalloproteinases 1 and 2 in human seminal plasma and their association with spermatozoa.

A 24-kDa heparin binding protein recently identified as tissue inhibitor of matrix metalloproteinases 2 (TIMP-2) in bovine seminal fluid was suggested to play an important role in bull fertility. As no data are present for men, the concentrations of tissue inhibitors of metalloproteinases 1 (TIMP-1) and TIMP-2 were quantified in human seminal plasma of normozoospermic and azoospermic men using enzyme-linked immunosorbent assay methods. TIMP-1 and 2 were not significantly different in both groups and there were no relationships between the concentrations of both TIMPs and other sperm characteristics. It is assumed that TIMPs are released from accessory sex glands.

Enzyme-Linked Immunosorbent Assay↗
PubMed2002

Anti-microbial susceptibility for east1 + Escherichia coli isolated from diarrheic pigs in Korea.

The in vitro susceptibilities of 128 isolates of east1 + Escherichia coli from pre-weaned and post-weaned pigs with diarrhoea were tested with nine commonly used anti-microbial agents by an agar dilution minimal inhibitory concentration (MIC) procedure according to National Committee for Clinical Laboratory Standards guidelines. For the isolates from preweaned and post-weaned pigs, most of them were susceptible to low concentrations (MIC90) of tetracycline (4 and 2 microg/ml), ceftiofur (2 and 2 microg/ml), and colistin (4 and 2 microg/ml). Marked resistance was found in others.

Animals↗
PubMed2002

Effects of SKI 306X, a new herbal agent, on proteoglycan degradation in cartilage explant culture and collagenase-induced rabbit osteoarthritis model.

OBJECTIVE: Protective effects of SKI 306X, a natural herbal product extracted from three herbs Clematis mandshurica, Trichosanthes kirilowii, and Prunella vulgaris, on articular cartilage was examined and compared with other osteoarthritis (OA) drugs using in vitro and in vivo models. METHODS: In vitro culture of rabbit articular cartilage explants was used as a model to measure the effects of drugs on the matrix degradation. The recombinant human interleukin-1alpha (rhIL-1alpha, 5 ng/ml) was added to induce proteoglycan (PG) degradation and the degree of PG degradation was assessed by measuring the amount of glycosaminoglycan (GAG) released into the culture medium. In in vivo experiment, collagenase was intraarticularly injected twice into the right knee joint of rabbits to induce OA-like change, and test agents were orally administered once a day for 28 days. The degrees of OA-like changes were evaluated through a histological examination. RESULTS: In vitro study revealed SKI 306X inhibited the degradation of PG in a concentration-dependent manner. Trichosanthes kirilowii, which is one of the major components of SKI 306X, also significantly inhibited the GAG release in cartilage explant culture at 0.3 and 0.1 mg/ml. Dexamethasone and NSAIDs, such as diclofenac and rofecoxib, had no significant effects on the suppression of PG degradation. In in vivo studies, OA-like degeneration of the articular cartilage and synovial tissue was induced by injecting collagenase into the right knee joint of mature rabbits. At a dose of 200 mg/kg, SKI 306X reduced the OA-like histological changes, whereas diclofenac had no effect at 10 mg/kg. CONCLUSION: These results indicate that SKI 306X inhibited PG degradation in cartilage explant culture, and its prophylactic administration significantly protected the knee joint of rabbit from OA-like change in collagenase-induced experimental OA model. This strongly suggests that SKI 306X can be a good OA agent with some cartilage protection activity.

Analysis of Variance↗
PubMed2002

Quantitative differences in matrix metalloproteinase (MMP)-2, but not in MMP-9, tissue inhibitor of metalloproteinase (TIMP)-1 or TIMP-2, in seminal plasma of normozoospermic and azoospermic patients.

BACKGROUND: Matrix metalloproteinases (MMPs) and their inhibitors, tissue inhibitors of metalloproteinases (TIMPs), have been detected in reproductive tissues and seminal plasma. The purpose of this study was to quantify MMP-2, MMP-9, TIMP-1 and TIMP-2 in human seminal plasma and to evaluate their association with sperm. METHODS: Seminal plasma was analysed using ELISA assays for all four analytes in 12 normozoospermic and 12 azoospermic patients and then for MMP-2 only in another 114 men with azoospermia (n = 16), after vasectomy (n = 20) and with sperm counts within the following ranges: 0.3-19 x 10(6)/ml (n = 20), 20-23 x 10(6)/ml (n = 11), 49-57 x 10(6)/ml (n = 12), 96-110 x 10(6)/ml (n = 12), 139-161 x 10(6)/ml (n = 12) and 215-346 x 10(6)/ml (n = 11). Additional zymographic analyses using SDS-PAGE were performed. RESULTS: All investigated MMPs and TIMPs were detected. MMP-9, TIMP-1 and TIMP-2 were not significantly different in normozoospermia and azoospermia. Only the MMP-2 concentration was significantly decreased in azoospermic compared with normozoospermic patients (mean +/- SD: 650.6 +/- 288.9 versus 1677 +/- 910.4 ng/ml respectively; P = 0.0002) and significantly correlated with the number of sperm (r = 0.54; P < 0.0001). CONCLUSION: MMP-2 in seminal plasma was strongly correlated to the sperm count in a linear fashion. Its origin and potential function remain to be elucidated.

Adult↗
PubMed2001

Enantioselective binding of ofloxacin to B form DNA.

The binding affinity and binding mode of S- and R-ofloxacin, one of the quinolone antibiotics, to B form calf thymus DNA were studied in this work. The binding affinity of S-ofloxacin measured by both Stern-Volmer and Benesi-Hilderbrand methods was greater by a factor of 5 compared to R-enantiomer and the CD spectrum of the former is largely altered while that of the latter remained the same in the presence of DNA, indicating the enantiospecific binding of this drug to DNA. The binding geometry of both S- and R-ofloxacin calculated from the reduced linear dichroism was similar to norfloxacin, which is partially intercalated from the minor groove.

Animals↗
PubMed2001

Molecular forms of prostate-specific antigen in serum with concentrations of total prostate-specific antigen <4 microg/L: are they useful tools for early detection and screening of prostate cancer?

Molecular forms of prostate-specific antigen (PSA) improve the differentiation between benign prostatic hyperplasia (BPH) and prostate cancer (PCa) in men with total PSA concentrations between 4 and 10 microg/l. To evaluate the diagnostic utility of free PSA (fPSA) and complexed PSA forms for identification of men with PCa in the low PSA range of <4 microg/l, total PSA (tPSA), alpha(1)-antichymotrypsin complexed PSA (PSA-ACT) and fPSA (Roche Elecsys [ES] system) as well as tPSA and complexed PSA (cPSA) (Bayer Immuno 1 system) were measured in archival serum samples from 31 untreated patients with PCa, 66 patients with BPH, and 90 men without prostatic disease. The median ratios of fPSA/tPSA, PSA-ACT/tPSA and cPSA/tPSA were significantly different between patients with BPH and PCa (27.2 vs. 19.4%, 64 vs. 88%, 77.2 vs. 88.2%, p < 0.05). No associations between PSA forms and tumor stage and grade were found. Analysis of the receiver operating characteristic curves showed that these ratios could discriminate better between BPH and PCa patients than determination of the analytes tPSA, fPSA, cPSA and PSA-ACT alone. The use of one of the ratios would have eliminated roughly half of the unnecessary biopsies in this study. The ratios should be considered as potential tools to increase the selectivity of PCa detection at low PSA concentration. The ratios fPSA/tPSA and cPSA/tPSA can be determined using commercially available assays so that one of these ratios could be preferred instead of PSA-ACT determination. The ratios could be useful in assessing the risk of PCa in the individual and therefore in deciding on prostate biopsy for final diagnosis.

Aged↗
PubMed2001

K+ stimulates specifically the autokinase activity of purified and reconstituted EnvZ of Escherichia coli.

The histidine kinase/response regulator system EnvZ/OmpR of Escherichia coli regulates transcription of the genes ompF and ompC, encoding two porins of the outer membrane. Although the total amount of OmpF and OmpC remains constant, the relative levels of the two proteins fluctuate in a reciprocal manner depending on medium osmolality. The membrane-anchored sensor EnvZ somehow monitors changes in environmental osmolality. To characterize the nature of the stimulus perceived by EnvZ, this protein was overproduced, purified, and reconstituted into proteoliposomes. Autokinase activity of purified and reconstituted EnvZ was stimulated by an increase of the K(+) concentration. Rb(+), Na(+), and NH4(+) also stimulated the activity but to a smaller extent, whereas an osmotic upshift imposed by various sugars or increasing concentrations of glycine betaine, proline, or Tris/MES were without influence. Neither the transfer of the phosphoryl group from EnvZ approximately P to OmpR nor the EnvZ-mediated OmpR approximately P dephosphorylation were affected by one of the tested solutes. Experiments with the reconstructed signal transduction cascade including DNA fragments demonstrated a substantial increase of the amount of phosphorylated OmpR in the presence of K(+) and to a lower extent in the presence of Na(+), Rb(+), and NH4(+). Various K(+) salts were tested indicating that the determined effects were K(+)-specific and not dependent on the anion. In a further in vitro test system, which utilizes right-side-out membrane vesicles, the K(+)-specific activation of EnvZ autokinase from the luminal side was confirmed. These results clearly indicate a regulation of EnvZ autokinase activity by monovalent ions, specifically K(+). Whether K(+) accumulation, which is one of the first responses of E. coli after an osmotic upshift, is related to the stimulation of the EnvZ autokinase activity in vivo is discussed.

Bacterial Outer Membrane Proteins↗
PubMed2001

Expression and regulation of prostate androgen regulated transcript-1 (PART-1) and identification of differential expression in prostatic cancer.

Prostate androgen regulated transcript 1 (PART-1), is a gene predominantly expressed in the prostate gland and is regulated by androgens in human prostate cancer cell lines. Here, we report additional characteristics of PART-1 tissue expression and hormonal regulation and study its expression profile in human normal and matched prostate cancer tissues. Since PART-1 shows similarity to prostate-specific antigen (PSA) in prostate specificity and regulation, we hypothesized that it may be implicated in prostate carcinogenesis or may be a potential new biomarker. We used reverse transcriptase polymerase chain reaction (RT-PCR) to further characterize PART-1 tissue expression and hormonal regulation in the LNCaP prostate cancer cell line. RT-PCR analysis revealed that PART-1 is expressed not only in the prostate and salivary gland, but also in other tissues, including the thymus and placenta. In addition to androgen stimulation, PART-1 is also up-regulated by progestins, oestrogens and glucocorticoids. We further studied the expression of PART-1 in 27 paired (from the same patient) cancerous and non-cancerous prostatic tissues, with qualitative and quantitative RT-PCR (LightCycler technology), in order to examine whether PART-1 is overexpressed or underexpressed in cancer. Our results indicated that PART-1 is more frequently overexpressed in the cancerous prostatic tissue. We conclude that this gene is overexpressed in prostate cancer and may represent a novel prostate cancer tumour marker.

Aged↗
PubMed2001

Expression of the normal epithelial cell-specific 1 (NES1; KLK10) candidate tumour suppressor gene in normal and malignant testicular tissue.

The normal epithelial cell-specific 1 (NES1) gene (official name kallikrein gene 10; KLK10) is a new member of the expanding human kallikrein gene family and encodes for a secreted serine protease. Experimental evidence suggests that NES1 controls normal cell growth and may function as a tumour suppressor. NES1 is down-regulated during breast cancer progression. The NES1 gene is highly expressed in testicular as well as in other tissues. In this study, we investigated the expression level of the NES1 gene in cancerous and normal testicular tissues with reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry. In all 14 primary testicular germ-cell tumours examined, the NES1 gene expression was markedly reduced compared to adjacent (paired) normal tissues. We further examined 6 randomly selected primary germ-cell tumours and 8 normal tissues (obtained from different individuals). We confirmed the differential expression of the NES1 gene in germ-cell tumours (GCT) and pre-malignant carcinoma in situ (CIS). Our findings suggest that NES1 may act as a tumour suppressor and may play a role in the pathogenesis and progression of this malignancy.

Base Sequence↗
PubMed2001

Identification and characterization of a novel human testis-specific kinase substrate gene which is downregulated in testicular tumors.

By using the positional candidate gene approach, we identified a novel putative serine/threonine kinase substrate gene that maps to chromosome 19q13.3. Screening of expressed sequence tags and reverse transcription-polymerase chain reaction of total RNA from human tissues allowed us to establish the expression of the gene and delineate its genomic organization (GenBank Accession No. AF200923). This gene (TSKS, for testis-specific kinase substrate) is composed of 11 exons and 10 intervening introns and is likely the human homolog of the mouse testis-specific serine kinase substrate gene. The predicted protein-coding region of the gene is 1779 bp, encoding for a 592-amino-acid polypeptide with a calculated molecular mass of 65.1 kDa. Genomic analysis of the region 19q13.3 placed the TSKS gene close to the known genes IRF3, RRAS, and alpha-Adaptin A. TSKS exhibits high levels of expression exclusively in human testicular tissue. The expression of TSKS is downregulated in cancerous testicular tissue, in comparison to adjacent normal tissue. TSKS expression was very low or undetectable in seminoma, teratocarcinoma, embryonal, and Leydig cell tumors, while high expression was observed in testicular tissue adjacent to tumors which contain premalignant carcinoma in situ. The expression of the TSKS gene was very low in two human embryonal carcinoma cell lines, 2102Ep and NTERA-2. These observations suggest a role of TSKS in testicular physiology, most probably in the process of spermatogenesis or spermiogenesis.

Amino Acid Sequence↗
PubMed2001

Mitochondria as subcellular targets for clinically useful anthracyclines.

Due to the widespread use of anthracyclines as antitumor agents, a large number of investigations have been reported analyzing clinical and molecular aspects of these quinone antibiotics. While the high affinity of anthracyclines towards chromosomal DNA has been held responsible for their antitumor activity, an increasing amount of data is being accumulated showing that these drugs also target mitochondria thus interfering with major mitochondrial functions. Since this toxicity of anthracyclines towards mitochondria is associated with side effects significantly limiting their chemotherapeutic dose, the corresponding underlying mechanisms need to be understood. Bioenergetic failure, enzyme inhibitions, lipid peroxidations, induction of membrane disorders as well as the initiation of oxidative stress are being attributed to the accumulation of anthracyclines at or inside mitochondria. In this review the wide spectrum of possible mode of actions of these antibiotics leading to mitochondrial dysfunctions will be presented and discussed.

Antibiotics, Antineoplastic↗
PubMed2001

Molecular cloning of a novel human acid phosphatase gene (ACPT) that is highly expressed in the testis.

Acid phosphatases are enzymes capable of hydrolyzing orthophosphoric acid esters in an acid medium. Prostatic acid phosphatase has served as a tumor marker for metastatic prostate cancer for many years. We have cloned a new human acid phosphatase gene (named testicular acid phosphatase, ACPT), which is expressed mainly in testis and to a lower extent in the prostate, trachea, and other tissues. This gene maps to chromosome 19q13.4, in an area that harbors many cancer-related genes. The testicular acid phosphatase gene is composed of 11 exons, and the protein is predicted to have a luminal domain, a transmembrane domain, and a cytoplasmic domain. The N-terminal end of the protein encodes a signal peptide. The protein has approximately 50% homology with both the prostatic and the lysosomal acid phosphatases, and the position of the cysteine residues, the N-glycosylation sites, and the histidine catalytic site are conserved among the three proteins. The testicular acid phosphatase gene is up-regulated by androgens and is down-regulated by estrogens in the prostate cancer cell line LNCaP. Our preliminary results indicate that this gene exhibits a lower level of expression in testicular cancer tissues than in their normal counterparts.

Acid Phosphatase↗
PubMed2001

A multicenter clinical trial on the use of alpha1-antichymotrypsin-prostate-specific antigen in prostate cancer diagnosis.

BACKGROUND: The aim was to evaluate the clinical performance of alpha(1)-antichymotrypsin prostate-specific antigen (PSA-ACT) for early diagnosis of prostate cancer (PCa) in a multicenter trial. METHODS: Three hundred sixty-seven white men with PCa and 290 with benign prostatic hyperplasia (BPH) with tPSA concentrations between 2 and 20 microg/L were analyzed. The Elecsys system 2010 (Roche Diagnostics, Germany) was used for determination of total PSA (tPSA) and free PSA (fPSA). The PSA-ACT test was a prototype assay used on the ES system (Roche Diagnostics). RESULTS: The median concentrations of tPSA (PCa: 8.43 microg/L vs. BPH: 6.60 microg/L) and PSA-ACT (8.30 microg/L vs. 6.46 microg/L) were significantly different, respectively. The median ratios of fPSA/tPSA (PCa: 12% vs. BPH: 16%) and PSA-ACT/tPSA (98% vs. 95%) were significantly different. Receiver operating characteristics (ROC) analysis for discrimination between PCa and BPH (tPSA between 2 and 20 microg/L) was performed with 252 matched pairs and showed that the area under the curve (AUC) of the ratio fPSA/tPSA (0.66) was significantly different from tPSA (0.50) and PSA-ACT (0.52). PSA-ACT alone or the ratio PSA-ACT/tPSA (0.56) were not significantly different from tPSA. For tPSA between 4 and 10 microg/L (n = 145 pairs), the AUC of the ratio fPSA/tPSA (0.65) was significantly higher than tPSA (0.50) and PSA-ACT (0.54). Significant differences between tPSA and PSA-ACT or PSA-ACT/tPSA (0.56) were not found. CONCLUSIONS: The determination of PSA-ACT as well as the PSA-ACT/tPSA ratio did not improve the diagnostic impact in patients undergoing evaluation for PCa compared to fPSA/tPSA ratio.

Adult↗
PubMed2001

Cloning of a new member of the human kallikrein gene family, KLK14, which is down-regulated in different malignancies.

Kallikreins (KLKs) belong to the serine protease family of proteolytic enzymes. Human pancreatic/renal KLK (KLK1) encodes for an enzyme that is involved in posttranslational processing of polypeptide precursors. The function of the other members of this gene family is currently unknown, but growing evidence suggests that many KLKs are implicated in carcinogenesis. By using the positional candidate approach, we were able to identify a new human KLK-like gene, KLK14 (also known as KLK-L6). This new gene maps to chromosome 19q13.3-q13.4 and is formed of seven exons (two untranslated and five coding exons) and six intervening introns. KLK14 was defined as a KLK gene based on structural and mapping criteria, in relation to other known KLK genes. KLK14 is expressed in a variety of tissues, but the highest levels of KLK14 are found in the central nervous system, including brain, cerebellum, and spinal cord. Our preliminary results show that KLK14 is down-regulated, at the mRNA level, in breast, testicular, prostatic, and ovarian cancer.

Amino Acid Sequence↗
PubMed2001

Receiver-operating characteristic as a tool for evaluating the diagnostic performance of prostate-specific antigen and its molecular forms--What has to be considered?

BACKGROUND: Receiver-operating characteristic (ROC) analysis is often applied as evaluation tool to compare the diagnostic validity of laboratory tests. The aim of this study was to draw attention to preconditions which should be taken into account when ROC analysis is used to assess the diagnostic performance of total prostate-specific antigen (tPSA) and its molecular forms in differential diagnosis between prostate cancer and benign prostatic hyperplasia (BPH). METHODS: Using a standard software (GraphROC for Windows), ROC analyses were performed and the areas under the curves were calculated for four hypothetical pairs of groups. Every group included 40 patients with prostate cancer and with BPH showing different tPSA concentrations (range of 2-10 microg, but similar free-to-total PSA ratios (fPSA%). RESULTS: The area under the fPSA% ROC curve showed the highest value, whereas the areas under the tPSA ROC curves were dependent on the distributions of tPSA concentrations in the patients. The ability of fPSA% to improve the differential diagnosis between prostate cancer and BPH in comparison to tPSA was not furthermore evident, if the prostate cancer group included more patients with higher tPSA concentrations than the BPH group. CONCLUSIONS: When the diagnostic performance of tPSA and its derivatives like molecular forms in patients with prostate cancer and BPH should be compared by ROC analysis, a matching procedure is recommended prior to ROC analysis to compensate the effect of possible unequal tPSA distributions in both groups. Each BPH (or PCa) patient should be matched with a PCa (or BPH) patient with nearest tPSA concentration so that an optimum of overlapping tPSA concentrations in both groups can be achieved.

Diagnosis, Differential↗