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Biomedical subjects

A Jung

Publications and source records attributed to A Jung.

At least 55 records · Page 3Linked to original sources
PubMed2001

Epstein-Barr virus infection in paediatric liver transplant recipients: detection of the virus in post-transplant tonsillectomy specimens.

AIMS: Post-transplant lymphoproliferative disease (PTLD) is an important and serious complication in transplant patients. Recent studies have suggested that quantitative assessment of Epstein-Barr virus (EBV) infection in transplant patients might help to identify those at risk of developing PTLD. Therefore, tonsils from paediatric liver transplant recipients were studied for evidence of EBV infection. METHODS: Tonsils were studied by in situ hybridisation for the detection of the small EBV encoded nuclear RNAs (EBERs). The phenotype of EBV infected cells was determined by double labelling in situ hybridisation and immunohistochemistry. The expression of viral latent and lytic antigens was determined by immunohistochemistry. Tonsils from patients without known immune defects were studied as controls. RESULTS: Tonsils from transplant patients showed pronounced follicular hyperplasia and minor paracortical hyperplasia. In situ hybridisation revealed variable numbers of EBV infected B cells in the tonsils from transplant patients (range, 2-1000/0.5 cm(2); mean, 434/0.5 cm(2); median, 105/0.5 cm(2)). Lower numbers were detected in the control tonsils (range, 1-200/0.5 cm(2); mean, 47/0.5 cm(2); median, 9/0.5 cm(2)). The latent membrane protein 1 (LMP1) of EBV was not detected and there were only rare cells in two cases showing expression of the EBV encoded nuclear antigen 2 (EBNA2). There was no evidence of lytic infection. None of the patients developed PTLD within a follow up period of up to five years. CONCLUSIONS: These data indicate that tonsillar enlargement in paediatric liver transplant patients does not necessarily imply a diagnosis of PTLD. Furthermore, the presence of increased numbers of EBV infected cells in tonsils from liver transplant recipients by itself does not indicate an increased risk of developing PTLD.

Antigens, Viral↗
PubMed2001

Improvement of semen quality by nocturnal scrotal cooling and moderate behavioural change to reduce genital heat stress in men with oligoasthenoteratozoospermia.

A questionnaire assessing factors that might cause an increase in scrotal temperature was completed by patients with reproducible oligoasthenoteratozoospermia of idiopathic nature or caused by varicocele. Evaluation by means of a grading scale revealed increased scrotal heat stress in oligoasthenoteratozoospermic patients compared with normozoospermic men (P < 0.01). In addition, long-term determination of 24 h scrotal temperature profiles showed that compared with semen donors, oligoasthenoteratozoospermic patients frequently had scrotal temperatures above 35.5 degrees C despite the same environmental temperatures (P < 0.05). In 88% of cases, maximum scrotal temperatures were measured during rest or sleep phases, whereas minimum values were recorded during physical activity or frequent change of position. Nocturnal scrotal cooling by means of an air stream resulted in a decrease in scrotal temperature of approximately 1 degrees C. Furthermore, a highly significant increase in sperm concentration (P < 0.0001) and total sperm output (P < 0.0001) was achieved after nocturnal scrotal cooling for 12 weeks together with a moderate decrease in factors leading to genital heat stress. A significant improvement in sperm motility (P < 0.05) and sperm morphology (P < 0.05) was also observed, but this improvement was markedly less pronounced than the changes in sperm concentration. This study shows the importance of genital heat stress as a cofactor in fertility impairment in men and indicates nocturnal scrotal cooling as a therapeutic option.

Behavior Therapy↗
PubMed2001

[Ultrasonographic examination in urinary tract infections].

The authors discuss the results ultrasonographic examination in children with urinary tract infections. The study included 435 children in aged 1 months-18 years treated in our Department since 1995 until 2000 y. In 260 (59.8%) children in USG examination changes in kidney were not observed. In 175 (40.2%) children changes in kidney were found.

Adolescent↗
PubMed2001

[Reasons for urinary tract infections in children based on personal observations].

The aim of this study was to analyse, basing on clinical observation, the reasons of urinary tract infection in children. The study included 1016 children with urinary tract infection /832 girls and 184 boys/ in the age between 2 weeks and 18 years old hospitalised in our Department in the period 1994-2000. The most common reasons of urinary tract infections were urinary tract abnormalities and the first among them was vesicoureteral reflux. In bacterial etiology Escherichia coli was the most common bacterial strain.

Adolescent↗
PubMed2000

[Ischemic cerebral apoplexy in children].

During two years we identified eight children aged 1.5-10 years with cerebral ischaemic stroke. Prior to the stroke seven of eight children were in full health. Predisposing factors were endocarditis and trauma. Four children had prodomal symptoms prior to the infarction. All had acute hemiparesis on admission. Three of the children had fever, and five had varicellazoster infection three to 18 months prior to the stroke. Three children had convulsions. Seven of eight children had stenoses or occlusions of the middle cerebral or the basilar artery. Five children have persistent deficits and none have died. The children did not have coagulopathies, hypertension or arteriosclerosis. Echocardiography did not show patent foramen ovale. Early clinical and neuroradiological investigations are of importance in reaching the appropriate diagnosis.

Cerebral Hemorrhage↗
PubMed2000

[Male infertility. Current life style could be responsible for infertility].

Optimal spermatogenesis requires the testicles to be at a lower temperature than the body core. This is achieved by the following factors:--Blood in the testicular artery is precooled by the surrounding veins of the plexus pampiniformis; nevertheless, high fever results in substantial warming of the testicles;--Heat loss via the scrotal skin, with tight-fitting, thermally insulating clothing or obesity having an unfavorable effect;--increased circulation of air around the genitals on physical activity;--High temperature gradient to the environment when ambient temperatures are low. If the combination of these factors is unfavorable, disturbed spermatogenesis and fertility may result, which, however, is usually reversible. Likewise, electromagnetic waves may impair spermatogenesis by heat induction in the testicles, but only when exposure is excessive.

Body Temperature↗
PubMed2000

Enhanced replication contributes to enrichment of hepatitis B virus with a deletion in the core gene.

Accumulation in immunosuppressed patients of hepatitis B virus (HBV) with a deletion in the C gene is associated with severe liver disease. The aim of this study was to determine the phenotype of such genomes in vitro. Four C gene fragments with different types of deletions were inserted in the context of a wild-type genome and tested by transfection into HuH7 cells. The deletions did not influence mRNA and surface protein levels. Truncated C gene translation products were expressed only from variants with in-frame deletions, whereas full-length polymerase was expressed from all variants at a similar or higher level than in wild-type virus. None of the variants was competent for autonomous replication; however, they produced 2- to 4.5-fold more progeny DNA than wild-type HBV when sufficiently complemented with wild-type core protein. Similarly, when variant and wild-type DNA were cotransfected in different ratios, the variants produced 2- to 5-fold more progeny DNA relative to the wild-type; this enrichment required the expression of the viral polymerase in cis. The mechanism of enrichment depended on the percentage of variant in the transfected DNA mixture. When the transfected DNA contained a small percentage of variant, enhanced replication of the variant accompanied by no or little suppression of wild-type replication was seen. Accordingly, overall production of progeny virus was slightly increased. At a high percentage of variant DNA, replication of both variant and wild-type decreased, probably due to a shortage of wild-type core protein. In conclusion, emergence of C gene deletion variants in vivo may be due to enhanced replication mediated at the level of encapsidation or reverse transcription. If the variants constitute a small part of the ccc DNA, they can be fully trans-complemented by wild-type virus which may increase the overall virus production.

Cells, Cultured↗
PubMed2000

Mitochondrial oxidative phosphorylation is a downstream regulator of nitric oxide effects on chondrocyte matrix synthesis and mineralization.

OBJECTIVE: Increased chondrocyte nitric oxide (NO) and peroxynitrite production appears to modulate decreased matrix synthesis and increased mineralization in osteoarthritis (OA). Because NO inhibits mitochondrial respiration, this study was undertaken to directly assess the potential role of chondrocyte mitochondrial oxidative phosphorylation (OXPHOS) in matrix synthesis and mineralization. METHODS: We studied cultured human articular chondrocytes and immortalized costal chondrocytes (TC28 cells). We also assessed the effects of antimycin A and oligomycin (inhibitors of mitochondrial complexes III and V, respectively) on chondrocyte mitochondrial respiration, ATP synthesis, and inorganic pyrophosphate (PPi) generation, and the mineralizing potential of released matrix vesicles (MV). RESULTS: Articular chondrocytes and TC28 cells respired at comparable rates. Peroxynitrite and NO donors markedly suppressed respiration and ATP generation in chondrocytes. Because NO exerts multiple effects on chondrocytes, we investigated the primary functions of mitochondrial respiration and OXPHOS. To do so, we identified minimally cytotoxic doses of antimycin and oligomycin, which both induced intracellular ATP depletion (by 50-80%), attenuated collagen and proteoglycan synthesis, and blocked transforming growth factor beta from increasing intracellular ATP and elaboration of PPi, a critical inhibitor of hydroxyapatite deposition. Antimycin and oligomycin also abrogated the ability of the ATP-hydrolyzing enzyme plasma cell membrane glycoprotein 1 (PC-1) to increase chondrocyte PPi generation. Finally, MV from cells treated with antimycin or oligomycin contained less PPi and precipitated >50% more 45Ca. CONCLUSION: Chondrocyte mitochondrial reserve, as NO-sensitive mitochondrial respiration-mediated ATP production, appears to support matrix synthesis and PPi elaboration and to regulate MV composition and mineralizing activity. NO-induced depression of chondrocyte respiration could modulate matrix loss and secondary cartilage mineralization in OA.

Adenosine Triphosphate↗
PubMed2000

p27(kip1) expression in rectal cancer correlates with disease-free survival.

BACKGROUND: The cell-cycle inhibitor p27(kip1) is a potential tumor suppressor and might serve as a prognostic marker in rectal cancer, in particular with regard to patient selection for adjuvant therapy. MATERIALS AND METHODS: Immunohistochemical analysis was performed, using an anti-p27(kip1) monoclonal antibody, on paraffin sections of two matched [age, gender, UICC stage, year of operation (1982-1991)] groups of patients (n = 2 x 82) with rectal carcinoma curatively treated by surgery alone. The groups differed only in subsequent metachronous distant metastatic spread. All patients had to meet the selection criterion "free of local disease," in order to exclude surgical influence. Follow-up was prospective (median of 74 months). The intensity of staining (-, +, ++, ) and rate of positive cells (as a percentage of total tumor volume) were judged separately for cytoplasms and nuclei. RESULTS: On multivariate analysis, cytoplasmic staining intensity proved to be the best prognostic factor of disease-free survival and approached statistical significance (P = 0.0552, Cox regression). On univariate analysis, considering cytoplasmic staining alone, intensely stained ( ) tumors showed significantly poorer disease-free survival (vs ++, +, -; Kaplan-Meier, logrank, P = 0.0185). CONCLUSIONS: The demonstrated correlation between cytoplasmic compartmentalization of p27(kip1) and increased metastatic spread as well as disease-free survival underscores the role of p27(kip1) in rectal cancer. However, since other reports emphasize the importance of nuclear p27(kip1) expression, the mechanisms of steady-state and subcellular distribution of p27(kip1) remain unclear, and further investigation is needed.

Adenocarcinoma↗
PubMed2000

Microsatellite instability in colorectal adenomas: relevance and clinical importance.

A number of investigations have recently been published on the role of microsatellite instability (MSI) in the process of colorectal carcinogenesis. The data concerning colorectal adenomas are difficult to compare (due to differences in the tumor collection, selection and number of analyzed loci, definition of high and low instability and histological types), and this review therefore examines the significance of the results of these publications. We then discuss the extent to which MSI and its effects on the integrity of the genome are early or late events in the malignant transformation, and which clinicopathological features are presented by MSI-positive adenomas. Finally, we consider the clinical importance of microsatellite status for the diagnosis of hereditary nonpolyposis colorectal cancer and the possibility of preventing adenomas and carcinomas by nonsteroidal anti-inflammatory drugs.

Adenoma↗
PubMed2000

Expression of nuclear beta-catenin and c-myc is correlated with tumor size but not with proliferative activity of colorectal adenomas.

Most colorectal cancers have loss-of-function mutations in the adenomatosis polyposis coli (APC) tumor suppressor gene. This leads to the accumulation of nuclear beta-catenin, which, together with the DNA-binding protein TCF-4, functions as a transcriptional activator. The recently defined target genes c-myc, cyclin D1, and matrilysin are responsible for tumor proliferation or malignant progression and explain the oncogenic potential of nuclear beta-catenin. To investigate its role in early colon carcinogenesis, we analyzed the expression of beta-catenin, its target gene c-myc, and the proliferative activity in 88 colorectal adenomas of varying size and grade of dysplasia. The results revealed i) the most significant correlation of nuclear beta-catenin and c-myc expression was not with the grade of dysplasia but with the size of the colon adenoma; ii) perfect correlation of nuclear beta-catenin and c-myc expression; iii) no significant correlation of adenoma size with the proliferative activity; and iv) no significant correlation of proliferative activity and the nuclear expression of beta-catenin and c-myc. These results imply that APC mutations have additional beta-catenin-independent functions; APC mutations alone are not sufficient for nuclear overexpression of beta-catenin; and nuclear beta-catenin has additional important functions for exceeding a threshold tumor size.

Adenoma↗
PubMed2000

Description of an intraperitoneal tumour xenograft survival model in the pig.

AIMS: Experimental animal studies are necessary if the results of minimally invasive oncological surgery are to be improved. In particular the influence of surgical technique on tumour implantation needs further assessment. Small animals such as rodents are inappropriate for such laparoscopic surgical studies. There is a requirement for another animal tumour model with animals greater in size. METHODS: Accordingly we developed an intraperitoneal tumour xenograft survival model using the domesticated pig. After creating a 12 mmHg pneumoperitoneum, 10(7)human HeLa cells were injected into the peritoneal cavity of nine non-syngeneic animals to induce tumour xenograft. Resection of the sigmoid colon using four trocars and a transanal double-stapling technique was performed. The mean operating time was 69 min. No signs of post-operative pain symptoms were observed, and all the animals survived the procedure and gained weight. After 4 weeks, the animals were sacrified and all incision sites and anastomoses were excised. RESULTS: Immunohistochemical staining with antihuman pancytokeratin antibodies confirmed tumour implants in 25 out of 36 port-sites (63.8%). No peritoneal carcinosis nor tumour implants at anastomosis sites were observed. CONCLUSION: This intraperitoneal xenograft tumour model in the pig can be applied in survival studies to check the quality of surgical techniques and its influence on tumour implantation following laparoscopy for cancer.

Animals↗
PubMed2000

[The role of environmental factors in the formation of kidney calculi].

Various endo- and exogenous factors play a role in the urinary stones formation tract. The aim of the study was to define the type and frequency of hyperexcretion of lithogenic substances in school children population and to determine an influence of risk factors on hyperexcretion of crystallizing substances. The study included 220 school children. Preurolithiasis state (PS) was found in 30% children. The most frequently hyperoxaluria, hyperuricosuria and hypercalciuria were diagnosed and it may be connected with abnormal nutritional habits, excessive application of multivitamins, vitamin D and calcium, disturbances in drinking water chemical composition (higher amount of calcium, smaller amount of magnesium, abnormal pH). Urinary tract infections, particularly in children with obstructive uropathy are an important risk factor in the examined population. Positive familial history of urolithiasis in 43.3% children may indicate for the important role of the genetic factor in the pathogenesis of the disease.

Adolescent↗
PubMed2000

[Etiology of nephrolithiasis in children: own observation].

Recurrent formation of renal calculi may be prevented by selective medical therapy designed to correct underlying metabolic disturbances in urine biochemistry. The aim of the study was to estimate potential risk factors of urolithiasis in 102 children before ESWL treatment. Metabolic disturbances followed by anatomical malformations of urinary tract, recurrent urinary tract infections caused by urease-induced microorganisms are the most frequent risk factors. In single cases possible risk factors were: immobilization and chronic corticosteroid therapy.

Child↗
PubMed2000

[Hypocitraturia in children with urolithiasis].

Inhibitors of crystallization process play an important role in renal-stone forming patients. One of well-known inhibitor is citrate. The aim of the study was to define the type of metabolic abnormality in children with nephrolithiasis and the role of urinary citrate excretion. 52 children with nephrolithiasis were examined. Hypocitraturia was observed in 42.3% of patients, most frequently in children with hypercalciuria, hyperoxaluria, and hyperoxaluria with hyperuricosuria. Low urinary citrate excretion found in patients with nephrolithiasis may play an important role in the pathogenesis of the disease. Urinary citrate excretion should be examined in patients with nephrolithiasis.

Adolescent↗
PubMed2000

[A form of premorbid condition of urolithiasis and urinary stone composition in children with urolithiasis].

In diagnosis, monitoring and prophylaxis of urolithiasis it is important to use simple, non-invasive tests. The aim of the study was to define the value of crystallizing ratios in urine in correlation with chemical stone composition in presumptive diagnosis and monitoring patients with urolithiasis. The study involved 102 children. An analysis of chemical stone composition was carried out in 62 cases. A correlation between values of crystallizing ratios in the urine, indicating the kind of preurolithiasis state and chemical stone composition has been found.

Adolescent↗
PubMed2000

[Results of ESWL treatment in children with urolithiasis: own experience].

Actually extracorporeal shock wave lithotripsy (ESWL) is the most frequent method in the treatment of urolithiasis in children. The aim of the study was to estimate the results of ESWL in children with urolithiasis. Between 1991 and 1999 y, in our Department 260 "reno-ureteral units" in 203 children were treated by lithotripsy. Totally of 518 ESWL procedures were performed. In general efficacy of ESWL was 88.08%, in children with single stone in kidney--97.80%., with multiple stones in kidneys--78.65%, in ureterolithiasis--71.88%. For complete recovery in patients mean 1.99 ESWL procedures were performed on 1 "reno-ureteral unit" on the average diameter of the stone/stones 13.3 mm.

Adolescent↗