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Biomedical subjects

G Bartsch

Publications and source records attributed to G Bartsch.

At least 253 records · Page 14Linked to original sources
PubMed1993

The National Marrow Donor Program.

As the number of successful marrow transplants has increased, the lack of HLA-identical sibling donors for 60 to 70 percent of transplant candidates has become a serious problem. Pilot studies established that marrow transplantation between phenotypically HLA-identical, unrelated individuals can be accomplished successfully. Therefore, the National Marrow Donor Program was established to develop a large file of volunteer marrow donors and to serve as a center for the coordination of the donor search and donor-recipient matching processes. By November 1991, 63 months after the program was established, 457,205 potential marrow donors typed for HLA-A and -B antigens had agreed to be listed in the marrow donor registry. A donor search had been initiated for 8481 patients. At least one potential donor matched for at least three of the four HLA-A and -B antigens was located for 99.8 percent of patients. Among the 3156 searches that were completed, 940 (29.8%) resulted in a transplant. The median time in which to locate a matched donor, complete all predonation evaluations, and obtain donor consent was 208 days. The most common diagnosis in patients who underwent transplantation was chronic myelogenous leukemia (42.0%). When this analysis was completed in November 1991, the National Marrow Donor Program was operating a national network of 99 donor centers and 53 transplant centers. The donor file was increasing rapidly, and a follow-up system was in place to determine the effects of donation on the donors and the outcome in the patients who underwent transplantation. This national network of donor and transplant centers exists and is now facilitating unrelated-donor marrow transplants. The National Marrow Donor Program made it possible to locate donors for many patients in need of a transplant and helped to determine the role of unrelated-donor marrow transplants in the treatment of many diseases.

Blood Component Removal↗
PubMed1993

Laparoscopic retroperitoneal lymphadenectomy in the pig: initial report.

The value of retroperitoneal lymphadenectomy in the management of nonseminomatous testicular tumors is still a matter of controversy. Lymphadenectomy doubtlessly has great advantages but is somewhat down-graded by the considerable associated morbidity. Our experimental study in six pigs has shown that retroperitoneal lymphadenectomy by means of laparoscopic techniques is feasible. Clinical trials will follow. Should they prove successful, the role of retroperitoneal lymphadenectomy in the management of testicular tumors has to be reassessed.

Animals↗
PubMed1993

Modified retroperitoneal lymphadenectomy for testicular tumor: anatomical approach, operative technique and results.

Between January 1988 and June 1992, 56 patients underwent nerve-preserving retroperitoneal lymphadenectomy at the Department of Urology, University of Innsbruck. In 23 patients stage I, and in 33 patients stage II testicular tumors were found (staging according to the criteria recommended in Lugano 1979). Orchiectomy and subsequent lymphadenectomy within the boundaries described by Weissbach's group were performed for stage I tumors. In patients presenting with stage IIa or IIb tumors modified retroperitoneal lymphadenectomy within the boundaries suggested by Colleselli's group was performed. In stage IIc patients the residual tumor was resected after three cycles of polychemotherapy. If possible, nerve-sparing lymphadenectomy was performed. By adapting the operative technique to the respective tumor stage antegrade ejaculation could be preserved in 47 of these 56 patients. Semen analysis was carried out in 22 patients. The results in patients with stages I and IIa tumors were excellent, while in stages IIb and IIc patients' exocrine testicular function was considerably worse due to inductive polychemotherapy. None of the patients had a retroperitoneal recurrence. Of all 56 patients only one had a relapse in the lung (1.7%). The average follow-up period was 29 months.

Adolescent↗
PubMed1993

Mutant androgen receptor detected in an advanced-stage prostatic carcinoma is activated by adrenal androgens and progesterone.

Structural changes of the androgen receptor (AR) may contribute to the development of resistance to endocrine therapy in prostatic carcinoma. We have isolated AR cDNA fragments from seven tumor specimens derived from patients with advanced metastatic prostatic tumors. In one specimen obtained from a patient who failed to respond to endocrine and cytotoxic therapy we have detected a point mutation in the hormone-binding domain of the receptor. This AR mutation is a guanine-to-adenine transition at nucleotide 2671 that leads to substitution of methionine for the wild type valine at position 715. It is a somatic mutation because it was not present in the AR genomic DNA fragments isolated from prostatic and testicular tissues of the same patient. The mutant AR was recreated in an expression vector and transiently expressed in COS-7 and CV-1 cells. Hormone-binding assays revealed that the mutant receptor does not differ from the wild type receptor in its ability to bind androgen. The dissociation constant for the synthetic androgen mibolerone was 3 nM for both receptors. There was also no significant difference in binding of other steroids and nonsteroidal antiandrogens as revealed by competition binding assays. However, transfection experiments to determine the trans-activation potential of the mutant receptor produced differences in the action of this receptor compared to the wild type receptor. Dihydrotestosterone and the synthetic androgens methyltrienolone (R1881) and mibolerone were equally proficient in conferring trans-activation activity to both the mutant and wild type receptors. Adrenal androgens such as dehydroepiandrosterone and androstenedione, as well as progesterone mediated a higher trans-activation through the mutant than through the wild type receptor. These data demonstrate that the exchange of a single valine into methionine at position 715 in the AR promoters trans-activation not only by testicular but also by adrenal androgens and progesterone. This pattern of ligand-dependent trans-activation may have significance in the process controlling the progression of prostatic carcinoma.

Adrenal Glands↗
PubMed1993

Left-sided laparoscopic adrenalectomy.

Laparoscopic transperitoneal adrenalectomy was performed in a 42-year-old female with a left adrenocortical adenoma causing Conn's syndrome. No technical problems occurred during surgery and the patient recovered quickly.

Adrenal Cortex Neoplasms↗
PubMed1993

[Modified retroperitoneal lymph node excision in testicular tumors. Anatomy, surgical technique and results].

Between January 1988 and June 1992, 56 patients suffering from malignant testicular tumors underwent nerve-preserving retroperitoneal lymphadenectomy at the University Hospital in Innsbruck. The tumors were staged according to the nomenclature recommended by the Workshop for Staging and Treatment of Testicular Cancer (Lugano 1979). According to this nomenclature 23 patients had stage I and 33 patients stage II. Thirty-nine patients presented with malignant teratoma, 3 with seminoma and 14 with teratoma and seminoma. The patients with stage I tumors were treated after orchiectomy with nerve-preserving retroperitoneal lymphadenectomy according to the dissection fields of Weissbach et al. In cases of nodal involvement in the retroperitoneum (stage IIa and IIb) a retroperitoneal modified lymphadenectomy according to the margins of Colleselli et al was performed. Patients with stage IIc tumors were treated with three cycles of polychemotherapy. Subsequently, the residual tumor was removed and, if possible, a nerve-sparing lymphadenectomy was performed. Since the nerve-preserving technique was modified in accordance with the tumor stage, antegrade ejaculation could be preserved in 47 of the 56 patients. In 22 patients exocrine testicular function was assessed by sperm analysis. The findings for the patients with stage I and IIa were considerable. The patients who had undergone induction chemotherapy for stage IIb and IIc had poor exocrine testicular function. The follow-up time was 29 months. At follow-up none of the patients presented with recurrent retroperitoneal tumor. Only one patient was found to have tumor progression (solitary pulmonary metastasis 1.7%). These results show that nerve-preserving retroperitoneal lymphadenectomy is the treatment of choice in stage I non-seminomatous testicular tumors.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

[Anatomy of the posterior urethra].

The short section of the urethra that passes through the urogenital diaphragm is termed the membranous urethra. It is accompanied by several vessels and nerve fibers. In surgery on the membranous urethra the perineal body is of crucial importance, and precise knowledge of the course of the urethra through the pelvic floor is essential. Furthermore, the relationship between the membranous urethra and its accompanying structures is of great importance. These include the branches of the internal pudendal artery, the prostatic venous plexus and the cavernous nerves coursing ventrally from the pelvic plexus. The nerves supplying the membranous urethra were studied in fetuses with the help of a magnifying lens. The results of the dissections are documented by histological sections, photographs and paintings.

Aged↗
PubMed1992

[Urethral rupture--primary repair and reconstruction].

Whether the posterior urethra can successfully be reconstructed depends mainly on the primary care, especially in the case of strictures secondary to trauma. Prior to surgery, primary care of the lesion is mandatory, including open suprapubic fistula, drainage of the cavum retii and of the perineal space, repositioning of the urethra and immediate stabilization of the pelvic ring by means of elastic procedures. In a second step, between 1978 and 1990 we performed bulbo-prostatic surgery in 27 patients with traumatic rupture of the posterior urethra. Based on extensive anatomic be studies on the relationship of the membranous urethra to the pelvic floor and to the arteries, veins and nerves, an operative approach via the perineal body was developed. Of 18 patients followed up, only 4 had flow rates of less than 15 ml/s. Retrograde urethrograms and micturition cystograms showed good results.

Adolescent↗
PubMed1992

Point mutation in the DNA binding domain of the androgen receptor in two families with Reifenstein syndrome.

Inadequate androgen action in genetic and gonadal males causes an intersex phenotype. We have analyzed the androgen receptor (AR) gene in male pseudohermaphrodites with normal specific binding of dihydrotestosterone in their genital skin fibroblasts. In five patients with Reifenstein syndrome we have detected a point mutation in the DNA binding domain. They are from two unrelated families and presented with perineoscrotal hypospadias and undescended testes. After puberty they showed small testes, no palpable prostate, micropenis, azoospermia, and gynecomastia. The mutation was discovered when cDNA fragments from three brothers were sequenced. For rapid detection of the mutation in heterozygous and hemizygous carriers, allele-specific PCRs and restriction-analysis techniques have been developed. Relatives of the patients, a group of normal blood donors, and other patients were screened with these methods. Among 41 intersex patients with incomplete virilization, another two brothers presenting with this mutation were identified. The mutation is a guanine-to-adenine transition at nucleotide 2314, which changes the alanine codon (GCC) immediately after the first cysteine of the second zinc finger motif of the AR into a threonine codon (ACC). The mutation was recreated in an AR expression vector, and wild-type as well as mutant ARs were expressed in COS-7 cells. Cotransfection experiments were made using a mouse mammary tumor virus-chloramphenicol acetyltransferase reporter gene. The ability of the mutant receptor to stimulate transcription of the reporter gene was reduced by about two-thirds, as compared with the wild-type receptor.

Alleles↗
PubMed1992

[Correlation of vesico-ureteral reflux and recurrent urinary tract infections with increased bacterial adherence].

Unimpeded urinary flow and voiding of the bladder without residual urine are essential for the prevention of urinary tract infections. Therefore, recurrent urinary tract infections are most commonly found in patients with functional and anatomic disorders of the urinary tract. Children suffering from vesico-ureteral reflux are especially susceptible to recurrent urinary tract infections. The interaction between germ and target cell, i.e. between antigen and receptor, is another important factor in the development of urinary tract infections. This so-called bacterial adherence is variable and depends upon receptor density as well as the affinity of the germ to the receptor. However, our study showed that this bacterial adherence plays a minor role in the development of recurrent urinary tract infections secondary to vesico-ureteral reflux.

Adolescent↗
PubMed1991

Growth-stimulating effect of adrenal androgens on the R3327 Dunning prostatic carcinoma.

Adrenal androgens are discussed as a reason for tumor progression after androgen ablation therapy. Because of the difference in the secretion of androgens by the adrenals of humans and rats, there is no reliable tumor model to study the role of adrenal androgens in tumor progression. Therefore, the main adrenal androgens were administered to rats in order to mimic human endocrine conditions. Application of dehydroepiandrosteron-sulfate (DHEA-S) alone or a mixture of androstendione (A), 11 beta-hydroxyandrostendione (OHA), dehydroepiandrosterone (DHEA), and its sulfate (DHEA-S) to castrated rats caused only a slight increase of prostate and seminal vesicle weight. Contrary to these findings, growth of the R3327 prostatic carcinoma in castrated rats was greatly stimulated by these adrenal androgens up to the level of the intact control. Thus, in spite of androgen ablation, tumor progression could be induced by exogenous adrenal androgens.

Adenocarcinoma↗
PubMed1991

Megalourethra.

Explore the source record for details and available documents.

Humans↗
PubMed1991

[The potential hormonal therapy of prostatic carcinoma].

Hormonal manipulation is still the most effective systemic treatment for prostate cancer. The alternatives to orchiectomy are discussed: estrogens, with their known cardiovascular side-effects, and the expensive LH-RH analogues and/or antiandrogens, the success of which depends heavily on the patient's compliance. With more intensive health care and more sensitive methods of diagnosis, not only is the overall number of prostate carcinomas diagnosed increasing, but also the percentage that need not be fatal. The timing of hormonal treatment and selection of patients are increasing in importance.

Aged↗
PubMed1991

[Approach to radical cystoprostatectomy].

A new possibility of using a standardized surgical approach is demonstrated by specific topographic-anatomical paintings. The operation, in this case radical cystoprostatectomy and lymphadenectomy in the man is demonstrated in the cadaver, from the incision of the skin to the excision of prostate and bladder. The significant surgical steps are documented in paintings, which allow exact documentation of the anatomical approach.

Cystectomy↗
PubMed1990

Isotachophoretic separation of organic acids in biological fluids.

The operating conditions for the isotachophoretic separation of organic acids were evaluated. At pH values ranging from 2.90 to 4.25 both relative step heights and molar flow-rates were determined experimentally for 26 anions. Comparing the observed values with simulated data, highly significant (p = 0.0001) correlation coefficients of 0.993 and 0.920, respectively, were found at pH 3.50. Whereas the concentration of the leading electrolyte did not affect the relative step heights, it increased the molar flow-rates significantly. The same applied to the detection current. The time of analysis was observed to be a function of the concentration of the leading electrolyte. However, the time elapsed between injection of the analyte and its detection depended solely on the volume and not on the amount of analyte injected. In isotachophoresis, incomplete separation of two compounds is indicated by the occurrence of a mixed zone which can hardly be distinguished from a pure zone. Thus, knowledge of the separation capacity is a prime prerequisite in optimizing the system for the analysis of biological fluids. The separability of nine equimolar pairs of anions was determined at pH values ranging from 2.90 to 4.25. Although two ionogenic constituents would separate only when their migration rates in the mixed state were different, no clear correlation was observed between separation capacity and difference in relative mobility. Separability, however, was found to increase with increasing concentration of the leading electrolyte. While the separation capacity was not influenced by the electric current, it was significantly affected by the volume injected. In subsequent analyses of serum, cerebrospinal fluid, seminal plasma and prostatic fluid, a variety of organic acids could be detected. Calibration graphs for the detected anions revealed a detection limit of 1 nmol and linearity over their biological concentration ranges. Further, the isotachophoretic results correlated well with high-performance liquid chromatographic and enzymatic analyses of citric acid and lactic acid in human seminal plasma and cerebrospinal fluid, respectively.

Acids↗
PubMed1990

Nerve-preserving bilateral retroperitoneal lymphadenectomy: anatomical study and operative approach.

In a study of the sympathetic trunk in 18 cadavers a new anatomical approach for modified bilateral retroperitoneal lymphadenectomy was developed, which is characterized by unilateral preservation of the L3 ganglion and the fibers arising from this ganglion. Furthermore, the sympathetic trunk and its lumbar branches were dissected, including the connections between the right and left sympathetic trunks arising from the L3 and L4 ganglia. On the right side the fibers were found dorsal to the inferior vena cava from where they pass into the aortocaval zone. Caudal to the inferior mesenteric artery these fibers communicate with the left para-aortic fibers. The precise topographic inter-relationship between the L2 and L3 ganglia was studied; the lower margin of the L3 ganglion was located 1 cm. cranial to the origin of the inferior mesenteric artery. Based on these findings a modified operative technique was developed for stages B1 and B2 testicular tumors. With the help of this modification it should be possible to preserve ejaculatory function in 50% of the patients who undergo an operation for small retroperitoneal tumors. However, this modification can be justified only if the recurrence rate is not higher than that with radical bilateral lymphadenectomy.

Adrenergic Fibers↗