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Biomedical subjects

J Schubert

Publications and source records attributed to J Schubert.

At least 91 records · Page 5Linked to original sources
PubMed2000

Characterisation of the enzymatic complex for the first step in glycosylphosphatidylinositol biosynthesis.

The mammalian N-acetylglucosaminyl transferase for the first step in glycosylphosphatidylinositol biosynthesis has been shown to consist of at least four components: PIG-A, PIG-C, PIG-H and GPI1. Here, the enzymatic complex is further characterised. PIG-A protein, which is thought to represent the catalytic subunit of the complex, was expressed in an epitope-tagged form in the PIG-A deficient JY5 lymphoblastoid cell line. Subcellular localisation of this protein was studied using immunofluorescence and immunoelectron microscopy. The protein was localised to both perinuclear and mitochondria-associated lamellae of the endoplasmic reticulum. Using affinity chromatography, epitope-tagged PIG-A protein was partially purified. To identify regions that might be involved in the catalytic process, computer-aided comparison was performed between PIG-A and 26 distantly related glycosyl transferases. A number of residues in the membrane-proximal region of the cytoplasmic domain (230-340) were found highly conserved. Finally, a topological model of the four partners participating in the enzymatic complex is introduced to provide a working model for further structural and functional analysis.

Amino Acid Sequence↗
PubMed2000

Glycosylphosphatidylinositol (GPI)-deficient Jurkat T cells as a model to study functions of GPI-anchored proteins.

Many cell surface proteins attached to the membrane by GPI are involved in cell signalling. However, the role of the GPI membrane anchor itself remains poorly understood. GPI-defective cells from patients with paroxysmal nocturnal haemoglobinuria (PNH) are relatively resistant to apoptosis induction. We developed a Jurkat T cell model for GPI deficiency by isolating a GPI-negative mutant, which is defective in the GPI biosynthetic gene PIG-A. Using retroviral PIG-A gene transfer along with the transfer of a vector control, we obtained two genetically identical cell lines, distinguished only by expression of the PIG-A gene and, thus, their ability to produce GPI. Cell proliferation and survival were not affected by this difference. Apoptotic stimuli such as serum starvation and camptothecin exposure elicited similar responses. In contrast, GPI-defective Jurkat cells were more susceptible to Fas-mediated apoptosis than GPI-positive cells. These results indicate that a deficiency in GPI-anchored proteins, as is found in PNH, does not confer resistance to apoptosis.

Apoptosis↗
PubMed2000

Preoperative simulation of partial nephrectomy with three-dimensional computed tomography.

OBJECTIVE: To evaluate prospectively the accuracy of computer-aided three-dimensional (3D) volume-rendered computed tomography (CT) in determining the appropriate anatomical limits (tumour size, tumour location, multifocality and vascular supply) and as a potential tool in the preoperative simulation of nephron-sparing surgery (NSS) in patients with small-volume renal cell carcinoma (RCC). PATIENTS AND METHODS: The study included 36 patients who underwent transperitoneal radical nephrectomy for RCC of < 4 cm diameter. Helical CT was undertaken before surgery and the extent of the tumour, the course of major renal arteries and veins, and the relationship of the tumour to the collecting system were shown by 3D volume-rendered CT. The CT findings were compared with the pathological results of all kidney specimens, obtained using 3-mm step-sections. RESULTS: Before nephrectomy, 39 renal tumours were identified in the 36 patients; three renal lesions of < 4 mm were not detected. All main venous branches and 42 of 43 arteries were identified by 3D volume-rendered CT. Knowing these features, a partial nephrectomy was simulated; a surgical lesion to the pelvicalyceal or vascular system which would have been produced by the simulated surgery was displayed in colour on the simulated surface of the section. CONCLUSION: Computer simulation provided an excellent 3D reconstruction of all kidneys, including the tumour, vasculature and renal hilum, allowing a significantly better preoperative evaluation of the renal mass. Visualizing possible resection margins and predicting the operative risks seem to be major advantages of this new method, especially when preparing for complex surgery. Reconstructed 3D CT appears to be a useful tool for defining the indications for and limitations of NSS.

Adult↗
PubMed2000

A study of pelvic floor function pre- and postradical prostatectomy using clinical neurourological investigations, urodynamics and electromyography.

OBJECTIVES: Incontinence after radical prostatectomy is addressed to sphincter damage and/or bladder dysfunction. Taking into account a high cure rate of incontinence by pelvic floor biofeedback treatment, the search for further mechanisms of a complex physiological concept seems feasible. METHODS: To characterize pelvic floor function, 18 patients were prospectively evaluated before and after radical prostatectomy by clinical neurourological tests, urodynamics and needle/surface electromyography (EMG). RESULTS: In all patients (mean age 62 years) investigations were completed successfully. The outcomes of neurourological investigations (sacral reflexes, voluntary pelvic floor contraction and relaxation) and needle EMG showed no significant changes in the pre-/postoperative comparison. Only by using surface EMG polygraphy change of activation patterns during pelvic floor contraction (decreased mean and medium frequency) could be found. CONCLUSION: In patients without preexisting bladder dysfunction and with a basically normal operative and postoperative course, fine motoric changes of pelvic floor function are the main finding. This cannot be explained by a pure anatomical approach. Neurophysiological events, like a barrage of nociceptive information, caused by surgical dissection and an inflammatory reaction due to the healing process, contribute to altered processing within the central nervous system. The appreciation of these mechanisms, well studied in neuroscience and pain research, offers a better understanding of surgery-related short- and longterm morbidity after pelvic surgery, i.e., urinary incontinence and erectile dysfunction.

Aged↗
PubMed2000

Audit of early bladder management complications after spinal cord injury in first-treating hospitals.

OBJECTIVE: The incidence of spinal cord injury is on the increase. It has been observed since World War II that proper initial management of the paralyzed bladder is a key factor in the prevention of complications of the urinary tract and renal function. METHODS: All traumatic spinal cord-injured patients admitted to the Thuringian Spinal Cord Rehabilitation Center, Sülzhayn, Germany, between January 1994 and December 1995 were reviewed for the method of initial bladder management, and all complications and events related to the urinary tract during the period from the date of injury/initial treatment in community-based hospitals to the date of transfer to our center were analyzed. RESULTS: The cohort included 170 spinal cord-injured patients (40 females, 130 males; mean age 35. 6 years). At the time of transfer to the rehabilitation center 48.8% of the patients still had an indwelling urethral catheter, 29.4% had a suprapubic catheter, and only 16.5% of the patients were on intermittent catheterization. The urine cultures were positive in 100, 44 and 28.6%, respectively. Severe complications due to an indwelling urethral catheter were seen in 15 patients. CONCLUSION: In contrast to early intermittent catheterization, indwelling urethral catheters are associated with a high complication rate. At the end of this century, the results of this study are most disappointing. There seems to be a lack of knowledge regarding sufficient bladder management in many hospitals and departments initially treating acute spinal cord-injured patients.

Adolescent↗
PubMed2000

Where are the limits of elective nephron- sparing surgery in renal cell carcinoma?

OBJECTIVES: The indication for elective nephron-sparing surgery (NSS) in renal cell carcinoma (RCC) is still controversial. The presented study was performed to determine limitations for NSS regarding to multifocality and to characterize the biological importance of these small tumor lesions. METHODS: In 372 patients who underwent radical nephrectomy for RCC consecutively, nephrectomy specimens were investigated by using 3-mm parenchyma sections regarding to local tumor spread and multifocality. To characterize multifocal tumors, we performed cytogenetic and molecular genetic investigations. RESULTS: Serial sections of 372 nephrectomy specimens revealed a total of 92 multifocal tumors in 61 specimens (16.4%). The correlation between tumor size and multifocality is shown as follows: tumor diameter 1-20 mm: 12.5%; 21-30 mm: 23.4%; 31-40 mm: 10.2%; >40 mm: 16.7%. The mean diameter of the multifocal tumors was 8.8x9.1x6.1 mm and the mean distance to the primary tumor was 26.4 mm (5-84 mm). Using cytogenetic and molecular genetic analysis, in nearly one third of all cases a concordance of chromosomal aberrations in primary and secondary tumors was found. CONCLUSIONS: Multifocality of renal cell carcinoma occurs independently from primary tumor size. The evidence of structural and/or numeric aberrations, found in additional tumor foci, obviously is an argument for their malignant potential. This findings have to be considered in preparation of nephron-sparing surgery for patients with renal cell carcinoma.

Carcinoma, Renal Cell↗
PubMed2000

Perisphincteric injection of botulinum toxin type A. A treatment option for patients with chronic prostatic pain?

BACKGROUND: Chronic prostatic pain is still a diagnostic and therapeutic problem. The clinical observation that prostatic and pelvic pain is accompanied by motoric and sensoric disorders of the pelvic floor muscles led to the hypothesis that prostatic pain roots in a changed processing of afferent and efferent information with the central nervous system (CNS). METHODS: Neuro-urological work-up of 11 male patients with chronic prostatic pain was completed. This included a clinical evaluation of pelvic floor function, urodynamic investigation of bladder and urethra function and a cystoscopy to exclude morphological aberrations. A transurethral perisphincteric injection of 200 units botulinum toxin type A (BTX) was followed by a 2- to 4-week visit to evaluate their influence on the neuro-urological symptomatology. RESULTS: All chronic prostatic pain patients suffered from a pathological pelvic floor tenderness, an inability of sufficient conscious pelvic floor control, a urethral hypersensitivity/hyperalgesia and a urethral muscle hyperactivity. Basic parameters of bladder function (capacity, sensitivity, compliance) were normal. The BTX injection was followed by a pelvic floor muscle weakening and a relief of prostatic pain and urethral hypersensitivity/hyperalgesia. A botulinum-related decrease of the functional urethral length, the urethral sphincter closure pressure, the postvoid residual volume and an increase of the peak and average uroflow were objectivated. CONCLUSION: A weakening of the urethral sphincter muscle via blocking acetylcholine release by BTX injection is followed by pain relief and symptom improvement. It can therefore be concluded that a barrage of nociceptive information from the dysfunctional pelvic floor overflood the CNS and induce a changed CNS processing. Interrupting the efferent branch of the disturbed central circle is one opportunity to treat chronic prostatic pain.

Adult↗
PubMed2000

The correlation of p53 protein overexpression and p53 antibodies in serum of patients with transitional cell carcinoma of the urinary bladder.

BACKGROUND: Mutations of p53 gene were demonstrated in many solid tumors with varying frequency. We analyzed the relationship between p53 protein expression in bladder cancer tissue, p53 autoantibodies in serum and the clinical course of 32 patients with and 10 patients without transitional cell carcinoma of the urinary bladder. MATERIALS AND METHODS: In the 32 patients studied, bladder cancer was diagnosed as pTaG1-2 in 8 cases, pT1G2 in 6, pT1G3 in 7, pT2G2-3 in 7, pT3G2-3 in 3 and pT4 in 1 patient. Anti-p53 antibodies were detected by an enzyme-linked immunosorbent assay. Immunohistochemical staining was performed using a standardized alkaline phosphatase monoclonal anti-alkaline phosphatase method. To prove the statistical significance of tumor grading and staging, the Kruskal-Wallis test was applied (p < 0.01). The mean follow-up was 26 months. RESULTS: We found 12.5% p53 autoantibody-positive sera without a statistically significant correlation with tumor grade (p = 0.0569) and category (p = 0.612). Three of 4 patients who had p53 autoantibody-positive sera died within 9 months. All of these sera-positive patients had p53 protein-positive tumor tissue. Control sera were all negative for p53 autoantibodies. CONCLUSION: This study shows a strong relationship between p53 protein overexpression and the occurrence of p53 autoantibody in bladder cancer. The expression of p53 autoantibodies seems to be an event in cases of bladder cancer with an unfavorable tumor-specific outcome. Because of the small number of cases and the short follow-up time, further quantitative studies will hopefully demonstrate whether this might be of prognostic importance.

Autoantibodies↗
PubMed2000

'Silent' surgical disease presenting with severe dysuria.

We report a case of long-standing dysuria due to silent surgical abscess disease. The cause of our patient's complaint was not expected because we focused on dysfunctional voiding and not dysfunction as result of pathology close to the bladder neck since the history given by the patient was unremarkable.

Abscess↗
PubMed2000

How accurate is diagnostic imaging in determination of size and multifocality of renal cell carcinoma as a prerequisite for nephron-sparing surgery?

BACKGROUND: The indication for elective nephron-sparing surgery (NSS) in renal cell carcinoma (RCC) is under discussion in the urological literature. The main problem of NSS is the multifocality of RCC. The presented study was performed to asses the accuracy of pre- and intraoperative ultrasound (US), and computerized tomography (CT) in determination of tumor size and detection of multifocal lesions. MATERIALS AND METHODS: Tumor size was measured by preoperative US and CT and compared with the tumor diameters in gross sections of the neoplastic kidneys. Multifocality was determined by 3-mm step sectioning of the nephrectomy specimen, and the results were correlated with preoperative US and CT on the one hand, and the ex situ sonography of the nephrectomized kidney on the other hand. RESULTS: US and CT show similar results in the determination of the tumor size. In only 22.9%, preoperative US and CT were able to detect multifocal tumors. Ex situ sonography had a sensitivity of 40.0% and a specificity of 87.2% in this regard. CONCLUSIONS: In preparation for nephron-sparing surgery of renal cell carcinoma, neither preoperative routine imaging, nor intraoperative ultrasound can safely predict multifocal lesions of renal cell carcinoma.

Carcinoma, Renal Cell↗
PubMed2000

Bronchogenic cyst. A rare differential diagnosis of retroperitoneal tumors.

Subdiaphragmatic bronchogenic cysts are rare, and those located retroperitoneally are exceptional. A review of the English-language literature revealed only 16 reported cases. We describe an additional case of a retroperitoneal cyst presenting as an asymptomatic adrenal mass and discuss clinical, radiographic, surgical and pathological findings as well as its embryological background.

Bronchogenic Cyst↗
PubMed2000

Sacral nerve stimulation for pain relief in interstitial cystitis.

A 60-year-old woman was treated for severe interstitial cystitis pain using sacral nerve stimulation. Pain and accompanying bladder dysfunction were improved by temporary and permanent sacral nerve stimulation. Six months after implantation of a sacral neuromodulator the patient is pain free and significantly improved on bladder dysfunction. Interstitial cystitis may be an indication for functional electrostimulation.

Cystitis, Interstitial↗
PubMed2000

Varieties of long-term outcome among patients in psychoanalysis and long-term psychotherapy. A review of findings in the Stockholm Outcome of Psychoanalysis and Psychotherapy Project (STOPP).

This paper reports the main findings of a large-scale study of subsidized psychoanalysis and long-term psychotherapy. More than 400 people in various phases, before, during and after subsidized psychoanalysis or long-term psychodynamic psychotherapy, were followed up for a period of three years with personal interviews, questionnaires and official statistics. Our analyses revealed progressive improvement the longer patients were in treatment--impressively strong among patients in psychoanalysis--on self-rating measures of symptom distress and morale. Improvement, however, was equally weak in both groups on a self-rating measure of social relations. Dosage factors (treatment duration and session frequency in combination) partly accounted for the outcome differences between those referred to psychoanalysis and those referred to long-term psychotherapy. Attitudes and ideals among therapists and analysts concerning the goals and means of psychotherapy were also associated with patient outcome, although in rather complex ways. A significant part of the outcome differences between patients in psychoanalysis and in psychotherapy could be explained by the adoption, in a large group of therapists, of orthodox psychoanalytic attitudes that seemed to be counterproductive in the practice of psychotherapy but not in psychoanalysis. It is suggested that this effect may be a negative transfer of the psychoanalytic stance into psychotherapeutic practice and that this may be especially pronounced when the attitudes are not backed up by psychoanalytic training.

Adult↗
PubMed2000

Genetic alterations in metastatic renal cell carcinoma detected by comparative genomic hybridization: correlation with clinical and histological data.

In order to optimize the management of patients with renal cell carcinoma (RCC) it is important to define the genetic risk for metastatic disease. In this study we performed comparative genomic hybridization (CGH) on metastatic tumors aiming at the identification of genetic alterations associated with metastatic disease. We analyzed 46 renal tumors along with their metastases, and 15 non-metastatic renal tumors. Tumors were classified pathologically according to the Heidelberg classification of RCC, and staged according to the TNM-system. Standard CGH was performed using microdissected archival tissues and DOP-PCR. The average numbers of chromosomal aberrations per tumor were 3.0, 2.1 and 3.9 in patients without metastasis, in patients who developed metastases after a two-year latency period (late onset of metastatic disease) and in patients who developed metastases within two years after therapy of the primary tumor (early onset of metastatic disease). CGH revealed chromosomal aberrations in 91% of primary metastatic tumors. Deletions or losses of chromosomes 9 (26% vs 6%), 10 (21% vs 6%) and 18 (23% vs 0) and 17 (28% vs 7%) occurred more often in metastatic tumors than in non-metastatic tumors. Furthermore, these aberrations were more common in patients with early metastases. CGH analysis of 40 pairs of primary RCCs and their corresponding metastasis revealed similar aberrations in 70% of cases. In 30%, however, metastases showed additional chromosomal aberrations not detected in the corresponding primary tumors. In conclusion, we identified genetic alterations associated with metastatic disease in RCC which could be useful for predicting prognosis. Genetic changes leading to metastases occurred early in tumorigenesis of metastatic tumors.

Carcinoma, Renal Cell↗
PubMed2000

Analysis of point mutation in exon 2 of CYP2E1 gene in renal cell/urothelial cancer patients in comparison with control population.

OBJECTIVE: Genetic polymorphisms of human cytochrome P450s have been implicated to be of importance for susceptibility to different cancers. Recently, a point mutation was found in the exon 2 of the CYP2E1 gene (CYP2E1*2) [Hu et al. 1997]. In order to evaluate a possible link between the point mutation in exon 2 of the CYP2E1 gene and the susceptibility to renal cell/urothelial cancer, we developed a screening method based on the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). MATERIAL: DNA of peripheral white blood cells was isolated from 158 renal cell/urothelial cancer patients as well as from 150 controls. METHOD: Primers for PCR were designed by the Primer 3 release 0.1 program. The PCR yield a product of 215 base pairs (bp), which was digested with the restriction enzyme Hha I. The DNA fragments were separated on a 3% agarose gel stained with ethidium bromide. Restriction enzyme digestion of the PCR product obtained from the wild-type DNA resulted in the appearance of a 66 bp, a 43 bp, a 40 bp, a 39 bp and a 28 bp DNA fragment. In contrast to the wild-type, the digestion of the PCR product from DNA carrying the point mutation resulted in the loss of the 39 bp and 40 bp fragments and the appearance of an additional 79 bp fragment. Therefore, the loss of one Hha I restriction site caused by a single nucleotide exchange is suitable for the identification of the point mutation in exon 2 of CYP2E1 gene. RESULTS: However, we could not detect any point mutation in any of the 158 renal cell/urothelial cancer patients or the 150 controls. The distribution of the point mutation in exon 2 of CYP2E1 gene did not show any difference in renal cell/urothelial cancer patients and controls. CONCLUSION: This might indicate a lack of association between this CYP2E polymorphism (CYP2E1*2) and renal cell/urothelial cancer.

Base Sequence↗
PubMed2000

Analysis of variability of P1 gene region of N strain of potato virus Y using temperature-gradient gel electrophoresis and DNA heteroduplex analysis.

Reaction conditions specific for reverse taranscription-polymerase chain reaction (RT-PCR) of potato virus Y strain NTN (PVYNTN) were used to amplify a 394 bp fragment of the P1 gene from selected PVY isolates with the aim to study the PVY variability within this genomic region. The P1 gene fragment from the Nicola isolate (Nicola P1/1 clone) was sequenced and characterized by temperature-gradient gel electrophoresis (TGGE). The Nicola P1/1 clone differed from that from the Hungarian isolate by double point mutation resulting in two changes at the deduced amino acid level. The clone showed simple transition from double-stranded to single-stranded form with two characteristic melting end points of about 41 degrees C and 48 degrees C. A more complicated TGGE pattern was, however, found for the whole P1 cDNA library of the Nicola isolate, suggesting accumulation of some minor sequence variants of PVY in this isolate. Based on the TGGE pattern, 46 degrees C was selected as the standard temperature for electrophoretic analysis of heteroduplex DNAs formed with the Nicola P1/1 DNA as reference. More than 40 other PVY isolates from PVYN group were analysed using this method. In most cases only minor fractions of electrophoretically distinguishable DNA heteroduplexes were found, however, in most isolates of PVYN-Wilga type, mixtures of the major sequence variants were observed. Two of these variants from the hybrid 220-5 (Czech Republic) were sequenced. Both of them differed from the Nicola P1/1 clone by 6 point mutations, which led to several changes at the amino acid level.

Amino Acid Sequence↗