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Biomedical subjects

A Jung

Publications and source records attributed to A Jung.

At least 91 records · Page 5Linked to original sources
PubMed1997

Therapeutic effects of leuprorelin microspheres in prostate cancer.

Leuprorelin has demonstrated effectiveness comparable to orchiectomy and oral diethylstilboestrol for the palliation of advanced prostate cancer. Unlike orchiectomy, leuprorelin's effects are reversible; also leuprorelin is not associated with the cardiovascular or thromboembolic adverse effects of oestrogens. For these reasons, leuprorelin has been widely used as an alternative to surgical castration or to oestrogens in the treatment of metastatic prostate cancer. Sustained-release leuprorelin microsphere formulations have been developed which exhibit zero order release of active drug from the injection site, such that in the United States the 7.5 mg dosage strength is recommended to be administered once a month and the 22.5 mg dosage strength once every three months. Although most patients will have suppressed release of pituitary luteinizing hormone by the third or fourth week after the first dose of depot leuprorelin, 4-5% of treated patients have been reported to have delayed responses, taking many more weeks or months to respond. A transient biochemical hormone escape has also been reported, although worsening of clinical symptoms has not accompanied the elevation of serum testosterone levels during treatment. Usually, leuprorelin is initiated as monotherapy when patients with advanced prostate cancer become symptomatic. However, newer studies of combination therapy of luteinizing hormone releasing hormone analogs with antiandrogens suggest that early initiation of therapy, at the time of diagnosis of advanced disease, may be beneficial, particularly in a subgroup of patients with small volume disease and good performance status. Leuprorelin is also undergoing evaluation as neoadjuvant therapy prior to radical prostatectomy for localized prostate cancer. Preliminary studies suggest that neoadjuvant leuprorelin in combination with an antiandrogen may be effective in downstaging prostate tumours. Leuprorelin commonly produces several adverse effects: hot flashes, decreased libido and impotence, and tumour flare.

Journal Article↗
PubMed1997

An electrophysiological analysis of altered cognitive functions in Huntington disease.

BACKGROUND: Neuropsychological deficits are a main feature of Huntington disease (HD) with previous data suggesting involvement of memory functions and visual processing. OBJECTIVE: To increase the knowledge about cognitive malfunction in HD in the domains of visual processing and memory by the use of modern electrophysiological techniques (event-related potentials [ERPs]). DESIGN: A case-control design was used. Three ERP paradigms were used; a parallel visual search paradigm allowed for the simultaneous processing of a multi-element visual array in search of a target stimulus, while a serial search paradigm with varied numbers of distractor items necessitated a serial one by one scanning of the arrays. The third experiment was a word-recognition memory task. SETTING: The measurements were obtained in a neurophysiological laboratory of a university hospital. PATIENTS AND CONTROLS: Nine patients with HD and 9 control subjects matched for age, sex, and education were studied. MAIN OUTCOME MEASURES: Components of averaged ERPs were quantified by latency and amplitude measures and subjected to statistical analysis. Behavioral measures (search time, hit rate, and recognition accuracy) were assessed as well. RESULTS: The early visual components showed a significant latency shift (delay of about 50 milliseconds) in HD. In the search paradigms the P3 components differentiating target and standard stimuli were virtually absent in HD as was the ERP effect indexing word recognition. This was accompanied by a marked delay in search times and lower hit rates in the search tasks and a grossly reduced recognition accuracy in the memory task. CONCLUSIONS: The results suggest marked impairments of patients with HD in early visual sensory processing (early components). Deficits in visual search might be attributed to an impairment to deploy attentional resources across the visual field and/or an inability to control eye movements. The ERPs in the memory task differed grossly from similar data obtained by others in patients with Alzheimer disease, suggesting a different neural basis for the amnesia in HD.

Adult↗
PubMed1997

The incidence of port-site metastases might be reduced.

BACKGROUND: Laparoscopic resection for cancer is controversial and port-site metastases are not infrequent. The mechanisms of occurrence of port-site metastases remain unclear. Animal experiments have suggested a role for carbon dioxide (CO2), but port-site metastases also occur after thoracoscopy, where no CO2 is used. The aim of this study was to define the role of CO2 in the seeding of tumor cells in the human patient. METHODS: CO2, instruments, trocars, suction device, and peritoneal washing were examined during 12 staging laparoscopies for pancreatic cancer. The presence, viability, and biological significance of cells were investigated using conventional cytology, polymerase chain reaction (PCR), and restriction fragment length polymorphisms (RFLPs) to detect the presence of a mutant k-ras gene as a genetic marker of cancer cells. RESULTS: Cytology exam of peritoneal washing, instruments, the suction device, and trocars revealed many cells. Tumor cells were detected in 6/12 peritoneal, in 4/12 trocars and 4/11 instruments washings, but not in 12 CO2 samples. The DNA content of CO2 was very low-as assessed by PCR. Mutant DNA was detected by RFLP in four out of 12 aerosols. Six aerosols did not contain any DNA. Two aerosols were borderline. CONCLUSIONS: During staging laparoscopy for pancreatic cancer in humans, CO2 contains only very low levels of free-floating tumor cells, even in the presence of massive peritoneal contamination. These results suggest that the incidence of port-site metastases might be reduced if mechanical contamination of the port sites with instruments or with the specimen can be avoided.

Adenocarcinoma↗
PubMed1997

[Regional cooperation in molecular biology topics].

Research on rare events, such as the occurrence of port-site metastases, can be speeded up by pooling patients from different hospitals. Multidisciplinary approaches, involving surgeons, pathologists and molecular biologists, allow more detailed experimental results to be obtained. Research costs are kept low by using existing infrastructures over a short period of time.

Cost-Benefit Analysis↗
PubMed1996

Human Y chromosome azoospermia factors (AZF) mapped to different subregions in Yq11.

In a large collaborative screening project, 370 men with idiopathic azoospermia or severe oligozoospermia were analysed for deletions of 76 DNA loci in Yq11. In 12 individuals, we observed de novo microdeletions involving several DNA loci, while an additional patient had an inherited deletion. They were mapped to three different subregions in Yq11. One subregion coincides to the AZF region defined recently in distal Yq11. The second and third subregion were mapped proximal to it, in proximal and middle Yq11, respectively. The different deletions observed were not overlapping but the extension of the deleted Y DNA in each subregion was similar in each patient analysed. In testis tissue sections, disruption of spermatogenesis was shown to be at the same phase when the microdeletion occurred in the same Yq11 subregion but at a different phase when the microdeletion occurred in a different Yq11 subregion. Therefore, we propose the presence of not one but three spermatogenesis loci in Yq11 and that each locus is active during a different phase of male germ cell development. As the most severe phenotype after deletion of each locus is azoospermia, we designated them as: AZFa, AZFb and AZFc. Their probable phase of function in human spermatogenesis and candidate genes involved will be discussed.

Chromosome Mapping↗
PubMed1996

Ageing and sperm function.

To evaluate the fertilizing capacity of spermatozoa from elderly men, ejaculates from 29 older fathers (mean age 50.3 years) were compared with those from 35 younger fathers (mean age 32.2 years). In addition to conventional semen parameters, sperm functions were studied that have been reported to be positively correlated with the fertilization rate: progressive motility, acrosin activity, inducible acrosome reaction, and chromosome condensation. Sperm concentration and follicle stimulating hormone concentration differed significantly in both groups. With regard to sperm functions there were no differences between older men and younger men, except for decreased sperm motility in the older group which, however, reached nearly normal values according to World Health Organization criteria. Decreased fertility of older couples is obviously more dependent on the age of the female partner. The significance of genetic risks remains to be clarified, especially when methods of assisted reproduction are applied.

Acrosin↗
PubMed1996

Adjunctive controlled topical application of tetracycline HCl in the treatment of localized persistent or recurrent periodontitis. Effects on clinical parameters and elastase-alpha1-proteinase inhibitor in gingival crevicular fluid.

35 patients receiving regular supportive periodontal therapy (SPT) and showing signs of localized persistent or recurrent periodontitis were enrolled in the study. Within 1 week after SPT, each patient had a tetracycline HCl loaded ethylene vinyl acetate co-polymer fiber placed into the periodontal pocket of 1 randomly selected tooth with persistent or recurrent periodontitis (test); the fiber was removed after 9.5+/-2.0 days. A non-adjacent tooth with persistent or recurrent periodontitis in a separate quadrant, which received no further treatment, served as a control. A total of 28 patients completed the 6-month study. Compared to control teeth, in test teeth at 6 months significantly (p<0.01) lower scores were found for gingival index, pocket probing depths, and PMN elastase-alpha1-proteinase inhibitor concentrations in gingival crevicular fluid. With the exception of plaque index scores, test teeth demonstrated significant reductions from baseline to 6 months in all parameters (p<0.05). Conversely, all parameter measurements in control teeth, except bleeding on probing, showed no significant difference between baseline and 6-month values. The results suggest that the use of controlled topical application of tetracycline HCl may improve periodontal health and reduce the risk of disease progression in localized persistent or recurrent periodontitis. Moreover, the effects of this application appear to be sustained for at least 6 months.

Administration, Topical↗
PubMed1996

[Use of thermographic methods for estimation of skin prick test results. II. Evaluation of skin prick test results with histamine solutions of different concentration using liquid crystal mixtures].

The aim of the study was to evaluate the usefulness of liquid crystal thermography in interpretation of skin prick tests with selected allergens and different solutions of histamine. The study group consisted of 35 young adults with indications for skin prick tests, and in whom skin tests with different solutions of histamine were also carried out (10 mg of histamine per 1 ml diluted to a concentration of 1:1, 1:10, 1:100). The skin reaction was assessed visually after 15 minutes, measuring flare and wheal diameter and utilizing the liquid crystal thermographic method--assessing the diameter of each colour green, blue, violet. For statistical purposes the area was also calculated. A correlation of each area was performed with the wheal and flare diameter. The area of the skin reaction was largest for both methods using the undiluted solution of histamine, the smallest using the 1:100 dilution. The liquid crystal thermographic method showed larger areas of skin lesions than those using only the visual method by analyzing the size of the wheal and flare. Due to this fact skin tests should be carried out at lest 9 cm apart from each other. The largest correlation was found between diameter of the flare and area of blue colour of the liquid crystal thermographic method (registering the temperature of 34.3 degrees C-36.3 degrees C). Using the thermographic method a joint temperature analysis of the wheal and flare lesions are performed. The results of this study correspond with the earlier, preliminary studies showing the usefulness of the liquid crystal thermographic method in assessing skin reactions to different allergens and histamine solutions.

Adolescent↗
PubMed1996

Andrological work-up of patients undergoing microsurgical epididymal sperm aspiration or testicular sperm extraction.

Microsurgical epididymal sperm aspiration (MESA) and testicular sperm extraction (TESE) require close cooperation between andrologists, urologists and gynaecologists. Intracytoplasmic sperm injections were established in Giessen in March 1994 and embryo transfer (ET) was performed in 342 of 375 patients (91.2%). The percentage of pregnancies and ongoing pregnancies are 35.4% per ET (32.3% per cycle) and 25.1% per ET (22.9% per cycle), respectively. Microsurgical procedures such as epididymovasostomy or vasovasostomy and cryopreservation of human semen are also established methods. The purpose of the present study was to describe the andrological work-up for patients before MESA and TESE. Experiments demonstrate that incubation of testicular tissue samples in IVF medium and treatment with 1 mg ml-1 pentoxifylline increase the number of extracted motile spermatozoa. Centrifugation of the medium results in a further concentration of sperm cells. If no motile spermatozoa can be found in the supernatant medium, they may be extracted directly from the testicular tissue samples by means of a micromanipulator.

Cell Separation↗
PubMed1995

Central nervous system lesions and cervical disc herniations in amateur divers.

Permanent neuropsychological changes such as memory disturbances and depression have been found in professional divers, even in those who have never had decompression sickness. The changes are probably the result of intravascular gas bubbles insufficient to cause acute symptoms. We examined amateur divers with long histories of self-contained underwater breathing apparatus diving by magnetic resonance imaging and compared them with normal controls. Hyperintense lesions of the subcortical cerebral white matter and degenerative changes of the cervical disks were significantly more common in the divers. 27 of 52 divers had a total of 86 focal hyperintensities versus 10 of 50 controls with 14 focal hyperintensities (p < 0.01). 32 divers had at least one degenerated intravertebral disc versus 9 controls (p < 0.0001). These results suggest that amateur divers are at risk of accumulating lesions in the central nervous system and in cartilage.

Adult↗
PubMed1995

Further evidence that the mouse defense test battery is useful for screening anxiolytic and panicolytic drugs: effects of acute and chronic treatment with alprazolam.

The Mouse Defense Test Battery (MDTB) has been designed to investigate defensive responses of Swiss-Webster mice confronted with a natural predator, a rat. These behaviors include flight, avoidance, defensive threat/attack responses, and risk assessment activities. Previous studies with the MDTB have suggested that this model may have some utility for the investigation of panicogenic and antipanic compounds. In the present study the MDTB was used to investigate the effects of acute (0.05-1 mg/kg, i.p., 30 min) or chronic (0.5-2 mg/kg, one daily i.p. injection during 10 days) treatment with the benzodiazepine receptor (BZPR) full agonist and panicolytic agent alprazolam. At non motor-impairing doses (0.05-0.5 mg/kg), acute alprazolam failed to alter the avoidance distance between the subject and the predator, the number of avoidances when the rat is approaching, predator assessment activities, defensive threat/attack responses when contact is forced between the subject and the predator or contextual escape attempts after the predator was removed. This was in contrast to chronic treatment which decreased both avoidance variables at 0.5 and 1 mg/kg, defensive threat/attack responses at all doses, and predator assessment responses at 0.5 mg/kg. In addition, the latter treatment reduced post-predator potentiation of escape attempts at 2 mg/kg. These results (1) confirm previous findings with the BZPR full agonist chlordiazepoxide, indicating that these compounds generally attenuate antipredator defensive responses in Swiss-Webster mice; (2) support recent data indicating that panic-altering drugs modulate flight/escape reactions, and suggest that the primary mechanism of action of drugs with efficacy against panic disorder may involve neural systems controlling flight; (3) confirm that the MDTB may be useful for the investigation of panicolytic as well as anxiolytic agents.

Alprazolam↗
PubMed1994

Sodium/calcium exchanger in olfactory receptor neurones of Xenopus laevis.

Ca2+ ions enter neurones through various types of calcium and cation channels. The mechanisms by which Ca2+ ions are spatially buffered and expelled from neurones have been studied considerable less. Using calcium imaging in conjunction with the patch clamp technique, we investigated the Na/Ca exchanger in olfactory neurones and found evidence for its localization on the dendrite. It is suggested that this tends to decouple increases in [Ca2+]i occurring in the transduction compartments of the cell from processes in the soma.

Animals↗
PubMed1994

[Pregnancy after drug therapy of severe andrological disorder].

Initial examination of an andrological patient revealed high-grade oligoasthenoteratozoospermia and ureaplasma infection. An elevated FSH level and significantly reduced testicular size were indicative of severely damaged testicular parenchyma. The presence of macrophages in the sperm smear was interpreted as a sign of chronic epididymitis. Antibiotic couple therapy with doxycycline, followed by a 3-month recovery period with combined treatment with vitamin C and E and zinc, resulted in a significantly improved spermiogram. After another 2 months intrauterine insemination resulted in pregnancy, and the birth of a healthy daughter followed. Preparation of the ejaculate was done by glasswool filtration. At that time, the patient had only mild teratozoospermia.

Adult↗