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Biomedical subjects

U Jonas

Publications and source records attributed to U Jonas.

At least 199 records · Page 11Linked to original sources
PubMed1994

[Metastatic adult teratoma of the testis. Possibilities of chemotherapy and surgical treatment].

We report on a patient with the diagnosis of an adult teratoma metastasizing as choriocarcinoma. The 49-year-old man died of dysfunction of the liver caused by massive metastatic involvement. This case demonstrates the malignant potential of adult teratoma and emphasizes the need for chemotherapy of the same kind as for other malignant germ cell tumours if undifferentiated metastases of the teratoma are present. The chemotherapeutic modalities and the options for surgical treatment of metastatic adult teratomas of the testis are discussed.

Carcinoma, Squamous Cell↗
PubMed1994

[Modulith SL 20. One-year urologic experience with a lithotripter of the third generation].

The MODULITH SL20 combines on-line ultrasound and optional X-ray in series. In addition to highly simplified patient positioning and the possibility of handling the machine as a multipurpose lithotripter for disintegration of urinary-, gallbladder and bile duct stones and for treatment of pancreatic concrements this appliance can be used in cases of sialolithiasis and as a workplace for all urological purposes, so that the design is very modern. As the energy level in f2 can be extremely high, a disintegration rate of about was achieved for 70% ureteral stones in the middle and distal sections of the ureter. However, this good disintegration rate was not achieved for ureteral stones lying in the upper ureter or in cases of nephrolithiasis treated with a prototype of the machine. In our opinion, this reflects a problem with nonexistent on-line X-ray stone localization, but an overall disintegration rate of about 77% in preselected patients (1.8 stones/patient) confirms that this is a highly sophisticated and powerful machine.

Cholelithiasis↗
PubMed1993

Identification of a fourth angiotensin AT1 receptor subtype in rat.

Angiotensin II is a major regulator of cardiovascular function, fluid homeostasis and also plays a role in long-term cardiovascular disease processes. At present it is unclear if and how the diverse functions of angiotensin II may relate to different cellular receptors for this vasoactive peptide. In order to identify subtypes of angiotensin receptors we used a PCR-mediated cloning approach. Oligonucleotide sequences for PCR amplification of angiotensin receptors were selected on the basis of nucleotide sequences conserved between species. Since the coding regions of AT1-type receptors appear to be located on a single exon, we used genomic DNA as a template in the PCR reactions. Resulting amplification products represented a mixture of four different sequences as assessed by T-tracking and sequencing of the partial clones. Three of the clones encode for sequences already known, whereas the fourth clone encoded a novel receptor subtype which we have termed AT1C. Deduced amino acid sequences of the four different receptor subtypes are highly homologous. The AT1C receptor nucleotide sequence homology was greatest to the described AT3 receptor (95%) and less so to the published AT1A (90%) and AT1B (82%) receptor subtypes. The variety and tissue- specific expression of AT1 receptor subtypes and coexpression of different receptor subtypes may account for the diverse tissue- specific actions of angiotensin.

Amino Acid Sequence↗
PubMed1993

Efficient pathway for early detection of prostate cancer concluded from a 5-year prospective study.

In a prospective study the statistical characteristics of digital rectal examination (DRE), transrectal ultrasound (TRUS), and serologic determination of prostate-specific antigen (PSA) were assessed in 1230 patients aged over 40 years. The sensitivity, specificity, and positive and negative predictive values were determined to be 80.3%, 69.7%, 58.9%, and 86.7%, respectively, for DRE; 76.5%, 62.3%, 52.3%, and 83.1%, respectively, for TRUS; and 87.9%, 49.6%, 48.5%, and 88.3%, respectively, for PSA (normal level, 4 ng/ml). The data clearly demonstrate the nonsuitability of each single measure for reliable early detection of prostatic carcinoma. Connection of the parameters in all possible combinations under various conditions demonstrated the superiority of the test "DRE and PSA > 4 ng/ml" over DRE as the "gold standard" and all other options. The use of this approach as the first-line raster of an algorithm (outlined herein) would allow the detection of prostatic malignancy with a specificity of 86.5% and a positive predictive value of 74.0%. Supplementing this screen with short-term controls in cases in which only one parameter is positive ("DRE or PSA > 4 ng/ml") might enable the detection of almost all patients with prostate cancer. TRUS did not provide any additional information.

Adult↗
PubMed1993

Effects of interleukin-1 and interleukin-6 on metallothionein and amyloid precursor protein expression in human neuroblastoma cells. Evidence that interleukin-6 possibly acts via a receptor different from the 80-kDa interleukin-6 receptor.

Since immunohistochemical studies indicated the presence of interleukin-6 in the cortices of patients with Alzheimer's disease, we were interested in the eventual biological effects of this cytokine on neuronal cells. We found that interleukin-6 and interleukin-1 induced metallothionein expression in a human neuronal (SH-SY5Y neuroblastoma) cell line. In contrast to metallothionein, amyloid precursor protein expression was unaffected by both cytokines. When searching in the same cell line for the expression of the classical 80-kDa interleukin-6 binding protein, which is part of the dimeric interleukin-6 receptor, we were unable to detect the respective mRNA. Our findings either indicate that the interleukin-6 receptor in these cells is expressed in extremely low levels or that interleukin-6 may act upon neuronal cells via a different, yet unknown neuronal receptor.

Amyloid beta-Protein Precursor↗
PubMed1993

Predictive value of real-time RigiScan monitoring for the etiology of organogenic impotence.

We performed routine diagnostic evaluations in 160 consecutive patients from our impotence clinic. After the diagnostic studies were completed, the results of RigiScan* monitoring during visual sexual stimulation before and after intracavernous injection of vasoactive drugs were compared to the results of standardized pharmacological testing, single potential analysis of cavernous electrical activity and pharmacocavernosometry. The results suggest RigiScan monitoring to be a highly accurate method to evaluate and document objectively the erectile response after intracavernous injection of vasoactive drugs. Although pathological monitoring after intracavernous injection is significantly associated with pathological findings in the specific evaluation, the predictive value of RigiScan monitoring for specific organogenic etiologies is not satisfactory, since normal monitoring showed no convincing correlation to single potential analysis of cavernous electrical activity or cavernosometry.

Erectile Dysfunction↗
PubMed1993

Followup results of a combination of calcitonin gene-related peptide and prostaglandin E1 in the treatment of erectile dysfunction.

Recent human and animal studies have shown a possible role for calcitonin gene-related peptide in penile erection and a therapeutic benefit in combination with prostaglandin E1 for autoinjection therapy. The ethical committee approved calcitonin gene-related peptide-prostaglandin E1 combination for cases of nonresponse or cavernous fibrosis to papaverine-phentolamine. Since June 1990, 65 patients (59 nonresponders and 6 with fibrosis) were injected with 5 micrograms. calcitonin gene-related peptide plus 10 micrograms. prostaglandin E1. Of the 59 nonresponders to papaverine-phentolamine 31 and of the 6 patients with fibrosis 5 had full erectile response. Of these 36 patients 2 experienced pain during the pharmacologically induced erection. A total of 39 patients who had had at least 20 autoinjections of calcitonin gene-related peptide plus prostaglandin E1 was available for minimum followup. There were no side effects, such as pain (the 2 patients with pain mentioned previously were not included in the autoinjection therapy group), systemic side effects or (increased) fibrosis. Our results show that a combination of calcitonin gene-related peptide and prostaglandin E1 may be beneficial to the treatment of impotence in carefully selected patients.

Alprostadil↗
PubMed1993

Single potential analysis of cavernous electrical activity. Four years' experience in more than 500 patients with erectile dysfunction.

Since the recent introduction of cavernous electromyography by Gerstenberg and Wagner, a new too for the study of erectile dysfunction in man is available. The refinement of this method, single potential analysis of cavernous electrical activity (SPACE), offers a straightforward approach to the diagnosis of cavernous autonomic neuropathy and smooth muscle myopathy by minimal invasive means. SPACE was done in more than 500 consecutive patients with erectile dysfunction and in 85 normal control subjects. With increasing experience the methodology was refined with respect to the used hardware as well as cut-off frequencies. In normal control subjects, SPACE showed a reproducible regular activity with potentials of low frequency and electrical silence inbetween. The potentials were synchronous throughout the cavernous bodies. In patients with peripheral autonomic denervation, asynchronous potentials with higher frequencies and irregular shape were found. Normal and abnormal potentials were found in patients with upper spinal cord lesions. Recordings obtained with surface electrodes showed similar characteristics when compared with recordings obtained with needle electrodes. Recent studies show that SPACE provides independent information about the autonomic and myogenic intactness of the cavernous tissue. Currently, a computerized expert system and a graded classification for easier interpretation is being developed with first results. We conclude that cavernous electrical activity can be recorded. SPACE is a reproducible diagnostic tool for erectile dysfunction.

Action Potentials↗
PubMed1993

Single potential analysis of cavernous electrical activity (SPACE). Experiences, limitations and perspectives.

Cavernous electromyography was first introduced by Wagner and Gerstenberg in 1989. The authors developed a refined method of cavernous electromyography by means of single potential analysis in introduced this method into clinical Urology as a diagnostic procedure for the evaluation of patients presenting with erectile dysfunction. To date, our experience with single potential analysis of cavernous electrical activity (SPACE) includes more than 500 patients with erectile dysfunction of various etiologies and 92 normal control subjects. Several technical modifications and refinements have been adopted during the last 4 years. In normal control subjects, SPACE shows a regular pattern of activity with long phases of electrical silence at the usual amplification interrupted by synchronous low frequency, high amplitude potentials. In patients with disruption of the peripheral autonomic supply, typical asynchronous potentials with higher frequencies and irregular shape are observed. In complete spinal cord lesions, abnormal as well as normal electrical activity is found. In patients with a long history of insulin-dependent diabetes and presumably cavernous smooth muscle degeneration, SPACE recordings show irregular potentials with low amplitudes and slow depolarization speed. Synchronization of electrical activity is usually absent. Recent studies on patients with venous leakage show that SPACE provides independent clinical information about the cavernous smooth musculature. The recording of cavernous electrical activity is possible and reproductible. In the future, a new software for one-line date processing, storage and interpretation of SPACE signals will be available.

Action Potentials↗
PubMed1993

Intracavernous application of SIN-I in rabbit and man: functional and toxicological results.

The mode of action of the active metabolite SIN-I of the vasodilator prodrug molsidomine was studied in vitro and in vivo in corpus cavernosum of rabbit and man. SIN-I produces a dose-dependent relaxation of isolated human cavernous smooth muscle strips. In the rabbit, the intracavernous application of SIN-I increased the intracavernous pressure to a full erection (approximately 100 cm H2O). This response was highly reproductible. SIN-I was also injected intracavernously 6 times in five rabbits over 2 weeks; no inflammatory or fibrotic reactions were found on histology. SIN-I may be a reliable drug for the treatment of impotence without side-effects.

Animals↗
PubMed1992

The influence of anterior root stimulation (S2) in deafferented spinal cord injury men on cavernous electrical activity.

Registration of cavernous electrical activity (single potential analysis of cavernous electrical activity) was recently suggested for the diagnosis of autonomic cavernous dysfunction. For validation of this method the effect of sacral neurostimulation on cavernous electrical activity was examined. In 3 male patients with a complete spinal cord lesion (T3, T4 and T12, respectively), deafferentation was done at the S2 to S5 levels. Around the anterior roots of S2 to S5 electrodes for neurostimulation were placed. Cavernous electrical activity was recorded with an intracavernous needle electrode and with surface electrodes in the flaccid as well as in the erect states induced by neurostimulation (at 7, 8, 12, 18, 20, 30 and 45 Hz., 30 v. and 0.4 msec). In all patients similar potentials compared to the normal values, as well as additional pathological potentials were recorded during flaccidity. During neurostimulation all patients achieved full erection with no or markedly decreased cavernous electrical activity to frequencies of 12, 18, 20 and 30 Hz., while to 7, 8 and, more pronounced, 45 Hz. only partial erection with ongoing cavernous electrical activity was found. Our study strongly suggests that cavernous electrical activity and, subsequently, the cavernous smooth muscle tone are dependent on autonomic input. This finding supports the hypothesis that single potential analysis of cavernous electrical activity may be valid in the diagnosis of cavernous autonomic dysfunction. Furthermore, our results suggest a possible role for single potential analysis of cavernous electrical activity in the fine tuning of erection inducing neurostimulators.

Adult↗
PubMed1992

A new therapeutic concept for long-lasting iatrogenic priapism: a case report.

In a therapeutic attempt on an 18-year-old patient with iatrogenic priapism lasting for more than 2 weeks after internal urethrotomy, intracavernous lysis was commenced with 80,000 IU streptokinase per hour. Following a dosage of 300,000 IU streptokinase the lysis was stopped because of severe bleeding from the urethrotomy scar. At 4 weeks after the patient was discharged from the hospital he reported normal erections and intercourse, while single potential analysis of cavernous electrical activity and ultrasound returned to normal. Provided there are no contraindications, intracavernous lysis seems to be an effective treatment for long-lasting priapism induced by intracavernous thrombosis.

Adolescent↗
PubMed1992

Preliminary results with the nitric oxide donor linsidomine chlorhydrate in the treatment of human erectile dysfunction.

Recent experimental studies showed an important role of endothelium derived relaxing factor for cavernous smooth muscle relaxation. Since nitric oxide seems to account for the biological actions of endothelium derived relaxing factor, a study was done to examine a possible role of the nitric oxide donor linsidomine chlorhydrate (SIN-1) in the treatment of erectile dysfunction. To determine a therapeutically useful dose 0.1, 0.2, 0.5 and 1 mg. SIN-1 were injected intracavernously in patients with erectile dysfunction. Each dose was given to 2 patients. Then, 63 patients received 1 mg. SIN-1, including 7 who had prolonged erections to minimal doses of papaverine plus phentolamine and 4 who did not respond with a full erection to other pharmacological agents. Intracavernous injection of SIN-1 induced a dose-dependent erectile response by increasing the arterial inflow and relaxing cavernous smooth muscles. Of the patients 29 had a full, 21 an almost full and 13 a moderate erection to 1 mg. SIN-1. There were no systemic or local side effects. In the patients with prolonged erections to papaverine plus phentolamine the mean duration of a full erectile response to SIN-1 was 57 minutes. Compared to the responses to a papaverine (15 mg./ml.) and phentolamine (0.5 mg./ml.) mixture, the erection induced by SIN-1 was superior in 10, comparable in 47 and inferior in 6 patients. Our data suggest a possible role for SIN-1 in the treatment of erectile dysfunction. Possible advantages may be that erection is induced by a mechanism similar to that occurring physiologically, a decreased risk of inducing prolonged erections and low therapy costs.

Blood Flow Velocity↗
PubMed1992

Significant obliteration of the urethral lumen after Wallstent implantation.

The permanently implanted self-expandable urethral stent (Wallstent) has found increased use in patients with recurrent urethral strictures because of its simple implantation technique. To date there have been no reports of serious complications. At 6 weeks after stent implantation our patient had complete luminal obstruction. This complication demonstrates the need for short-term controls after implantation of a urethral stent.

Aged↗
PubMed1992

Transcutaneous registration of cavernous smooth muscle electrical activity: noninvasive diagnosis of neurogenic autonomic impotence.

Registration of cavernous electrical activity was shown to be a possible method for the evaluation of cavernous autonomic innervation. Recent studies in patients with normal erectile function showed that cavernous electrical activity is synchronous throughout the entire cavernous bodies. Therefore, we examined the feasibility of transcutaneous registration of cavernous electrical activity in 8 normal and 62 impotent patients. In the sitting patient cavernous electrical activity was recorded with a 2-channel electrophysiological unit. Recording was done with a coaxial needle electrode in the proximal left cavernous body and with surface electrodes bilaterally on the penile shaft. In 7 of 8 normal patients swelling of the penile shaft after circumcision resulted in a dramatically decreased amplitude of the potentials. In 41 of 62 impotent patients recordings were similar. In 10 of 62 patients no recording or markedly decreased amplitudes were noted with the surface electrodes and in these patients a small penis or penile retraction with consecutive electrode displacement was found. Careful repositioning of the surface electrodes with the patient in the supine position resulted in similar recordings in 9 (inconsistently in 4). In 11 of the 62 patients more information was obtained with the surface than with the needle electrode. Our results show that recording of cavernous electrical activity can be done in a completely noninvasive manner using surface electrodes with similar or even better information obtained than with needle electrodes.

Action Potentials↗
PubMed1992

Detection of interleukin-6 and alpha 2-macroglobulin immunoreactivity in cortex and hippocampus of Alzheimer's disease patients.

We examined brains from Alzheimer's disease (AD) patients by immunohistochemistry for the presence of protease inhibitors. Immunoreactivity for alpha 2-macroglobulin (alpha 2-M), the most potent of the known human protease inhibitors, was found in a subgroup of cortical and hippocampal AD senile plaques. In addition, large hippocampal neurons in AD brains displayed intracellular alpha 2-M immunoreactivity which was consistently stronger than in normal aged brains. In cultured human cells of neurogenic origin (SH-SY5Y neuroblastoma cells), alpha 2-M synthesis could be strongly induced by the inflammatory cytokine interleukin-6 (IL-6) indicating that human alpha 2-M behaves as an acute-phase protein in the nervous system. Therefore, we also examined AD brains for the presence of IL-6 and found strong immunostaining in and around a subgroup of senile plaques as well as around large cortical neurons. Only very few senile plaques also stained for C-reactive protein, an acute phase protein known to be inducible by IL-6. We propose that the presence of IL-6 and alpha 2-M immunoreactivity in AD brains is functionally linked and that a sequence of immunological events is part of the pathology of AD.

Aged↗
PubMed1992

Treatment of anejaculation with electroejaculation.

Male infertility caused by anejaculation is common after spinal cord injury (SCI) and following retroperitoneal lymph node dissection (RPLND) for testicular cancer. Other conditions sometimes associated with neurogenic ejaculation loss are diabetes mellitus, multiple sclerosis, extensive pelvic surgery and adult myelodysplasia. Primary absence of ejaculation also has been described. Few treatment options exist for these patients, if they wish to father a child. With electroejaculation (EEJ), or the low-current stimulation of the ejaculatory organs via a rectal probe, emission of semen can be initiated in these men. In non-SCI-patients EEJ requires general anaesthesia. The collected semen is washed and the motile sperm fraction isolated before artificial insemination (AI) of the partner. At the University of Michigan 198 men have been treated between 1986 and December 1991. An ejaculate could be obtained from nearly all patients. A major obstacle to success is the severe asthenozoospermia and the poor functional quality of the obtained sperm samples. This can be caused by the EEJ-technique itself, as well as by the long anejaculatory status. A semen sample with at least 10 million progressively motile sperm cells, useful for AI, was obtained in 75% of the SCI men and in 87% of the men following RPLND. In the couples wishing insemination, 49 pregnancies were induced, accounting for an overall pregnancy rate of 35% per couple. Thirty five healthy babies have been born. Only three complications were encountered. At Hannover Medical School only few patients have been stimulated to date. We could obtain an adequate sperm sample for AI from all of them. No complications were seen. As the first couple has just entered the phase of AI with husband sperm, an analysis of these results would be premature. Electroejaculation combined with artificial insemination is an efficient and safe treatment of male infertility due to neurogenic anejaculation.

Adult↗