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Biomedical subjects

C van der Horst

Publications and source records attributed to C van der Horst.

At least 19 recordsLinked to original sources
PubMed2006

[The influence of the T stage on the risk of metastasis of penis cancer: T1 vs. T2].

BACKGROUND: Controversies persist over the therapeutic approach to T1 penile carcinoma, particularly in patients with negative inguinal lymph nodes. Available data on lymph nodes metastases (LNM) in T1 carcinoma are contradictory. The aim of this study was to evaluate the metastatic risk of T1 carcinoma and to compare it with that of T2 carcinoma. MATERIAL AND METHODS: A total of 37 patients (pts) with T1 or T2 tumors were reviewed. Assessment of the inguinal lymph node condition was based on node dissection in 29 pts and surveillance in eight pts (mean 62 months, range 22-162). RESULTS: Grading was classified as good (G1), moderate (G2) and poor (G3) in seven, 26 and four pts, respectively. Tumor stage was T1 in 21 and T2 in 16 pts. LNM were observed in eight of 21 T1 (38%) and six of 16 T2 tumors (38%). No G1 and all G3 tumors developed LNM independently of tumor stage. Ten of the 26 G2 carcinomas (38%) harboured LNM and seven of these pts (70%) had a T1 tumor. CONCLUSIONS: According to our data, the metastatic potential of T1 penile carcinoma has been underestimated in the recent literature. Tumor grading has a substantially stronger impact on the metastatic risk in T1 and T2 penile carcinoma than tumor stage, indicating a surgical lymph node staging starting at the pT1G2 stage.

Adult↗
PubMed2006

[Urinary incontinence and urodynamics].

Incontinence can be the result of impaired functioning of the detrusor muscle and/or the sphincter mechanism. For this reason, the pathomorphology and the pathophysiology should be documented before surgery, so that if it is not successful it is possible to deduce what alterations have been caused by an operation and the reason why the treatment has not been successful. Vaginal reconstruction of the pelvic floor following vaginal prolapse is a safe, effective surgical procedure, particularly for older women. Abdominal fixation of the vaginal stump through open or laparoscopic sacrocolpopexy gives long-lasting and anatomically favourable results especially for younger women who are sexually active, but is associated with a higher mortality rate. Incontinence treatment in men is itself gradually becoming accepted as a subspecialty. Pharmacological treatment that is used for urge incontinence takes the form of substances that relax or desensitize the detrusor (antimuscarinics, oestrogens, alpha-blockers, beta-mimetics, botulinum toxin A, resiniferatoxin, vinpocetin), while stress incontinence requires stimulation of the sphincter and pelvic floor (alpha-mimetics, oestrogens, duloxetin). Bladder function disturbances in children can be classified by noninvasive methods, but the therapy remains a difficult endurance test for the children, their parents and the doctor, often extending over years.

Adult↗
PubMed2006

Impact of electrostimulation of neurovascular bundles and pudendal nerves on the membranous urethra in male rabbits.

PURPOSE: The pathophysiology of post-prostatectomy incontinence is supposed to be multifactorial. The impact of the neurovascular bundles on sphincter function is still under debate. We clarified the impact of cavernous nerves function on the MU. We compared MU pressure responses in male rabbits following electrophysiological stimulation trials on the neurovascular bundles vs pudendal nerve stimulation. MATERIALS AND METHODS: Six male Chinchilla Bastard rabbits were included in this study. Pudendal and cavernous nerve branches were exposed bilaterally in all animals. Randomized electrostimulation of pudendal nerve fibers and the cavernous nerves, as confirmed by erection,) were done using a biphasic signal form of 0.3 mA for 200 microseconds. Stimulation frequency was changed in a randomized pattern from 10 to 40 Hz. Changes in MU pressure were measured urodynamically via a transurethral microtip catheter placed in the MU. Stimulation responses of the 2 nerve structures were compared. RESULTS: Mean baseline pressure in the MU without stimulation was 23 cm H(2)O (range 20 to 25) in all animals. During unilateral pudendal stimulation the mean pressure response increased highly significantly to 33, 43, 59 and 60 cm H(2)O at 10, 20, 30 and 40 Hz, respectively (p <0.005). In contrast, compared to baseline pressure cavernous nerve stimulation did not result in any significant changes in proximal urethral pressure (mean 23 cm H(2)O, range 20 to 25, p >0.05). CONCLUSIONS: Our results confirm the primacy of the pudendal nerve in the external urethral sphincter innervation. In contrast, stimulation of the cavernous nerves did not produce any pressure changes in the MU. These results confirm that the neurovascular bundles have no functional impact on the MU.

Animals↗
PubMed2006

[Induction of spermatogenesis in patients with non-obstructive azoospermia after antegrade sclerotherapy].

PURPOSE: The aim of this study was to prove the efficacy of antegrade sclerotherapy for varicocele testis in patients with azoospermia and in patients with cryptozoospermia (less than 0.1 million spermatozoons/mL ejaculate). We have investigated the induction of spermatogenesis in patients with non-obstructive azoospermia after antegrade sclerotherapy. MATERIALS AND METHODS: 20 consecutive patients who had been trying to beget a child over a period of one year or longer were chosen for this study. All patients suffered from non-obstructive azoospermia or from cryptozoospermia. We produced a control spermiogram for each patient before, 3 and 6 months after antegrade sclerotherapy. The postoperative spermiogram was done according to WHO criteria and was then compared to the preoperative data. RESULTS: 15 patients (75 %) were found to suffer from azoospermia preoperatively and 5 patients (25 %) from cryptozoospermia. Out of the 15 patients with initial azoospermia 8 (53 %) showed cryptozoospermia (OAT/OT syndrome) after antegrade sclerotherapy. Out of the 5 patients with the initial cryptozoospermia 3 (60 %) showed an improvement in the sperm count and motility criteria. CONCLUSIONS: Antegrade sclerotherapy for varicocele testis is a valid treatment option to isolate the spermatozoons from the ejaculate for extracorporeal fertilisation in patients with non-obstructive azoospermia. Complete normalisation of the spermiogram parameters, i.e., sufficient for natural child conception, cannot safely be achieved by this method.

Adult↗
PubMed2006

[Use of permanent electrodes in the peripheral nerve evaluation test (PNE-Test) in comparison to conventional wire electrodes].

PURPOSE: Prior to implantation of a chronic sacral neurostimulator, it is important to establish which patients might profit from this kind of therapy in order to ensure, by means of a PNE (peripheral nerve evaluation) test, that the implantation of a permanent stimulating device is effective. In this study we compared the two different techniques used in our department (implantation of the permanent neurostimulation electrodes, the so-called "two-stage-implantation" vs. conventional PNE). MATERIALS AND METHODS: We performed a sacral nerve stimulation in 53 patients (mean age: 49.7 years, range: 14 - 75 years) over a minimum of 5 days. In 42 patients we performed a conventional PNE, 11 patients underwent "two-stage implantation" with implantation of the permanent electrodes. RESULTS: 52 of 53 patients received bilateral test stimulation (9 % at S2, 91 % at S3). One patient underwent unilateral PNE (S3) because of an anatomic deformity of the os sacrum. In 20 cases the conventional PNE-test (cPNE) was successful according to standard criteria (47.6 % of all cPNE). The response rate of "two-stage implantation" with implantation of the permanent electrodes was 81.8 % (9 of 11 patients). CONCLUSIONS: The success rate of implantation of permanent neurostimulation electrodes in selecting patients for the permanent implant is significantly higher than the conventional PNE. In this group patients with neurogenic and overactive bladder dysfunctions showed the highest response rates to sacral nerve stimulation and are the most likely to benefit from sacral neuromodulation.

Adolescent↗
PubMed2005

[Erectile function after nerve-sparing radical prostatectomy. Nocturnal early erection as a parameter of postoperative organic erectile integrity].

The time lapse before recovery of erectile function after nerve-sparing radical prostatectomy is still under debate. Several pathophysiologies are postulated for postoperative erectile function rehabilitation. In prospective studies we measured nocturnal penile tumescence (NPTR) in the acute phase during the first night after catheter removal subsequent to nerve-sparing radical prostatectomy to assess the neuronal organic erectile integrity. Eighteen sexually active patients suffering from local prostate cancer underwent bilateral and unilateral nerve-sparing retropubic radical prostatectomy. All patients completed an IIEF-5 questionnaire concerning erectile function preoperatively. The transurethral catheter was removed 14 days after surgery, and nocturnal penile tumescence was measured with an erectometer (Rigi-Scan) in each patient during the following night. None of these patients received any comedication interacting with erectile function. The preoperative IIEF score was >18 in all patients. After catheter removal, 17 of 18 patients (95%) had nocturnal penile radial rigidity >70% that persisted for >10 min during one night. In a control of four patients without a nerve-sparing procedure, no nocturnal erections were recorded. The measurement of NPTR in the acute phase after nerve-sparing radical prostatectomy showed retained erectile function even during the "first" night after catheter removal. Our findings are important for an appropriate choice of pharmacotherapy for optimal recovery of erectile function. In cases of early penile erections, the cavernous nerve had been well preserved during surgery providing good neuronal integrity, and PDE-5 inhibitors can support organic rehabilitation of the corpus cavernosum. In the absence of early penile erections, the neuronal integrity of the cavernous nerve is presumed to be impaired. In this case, additional injection therapy should be chosen to support recovery of spontaneous erectile function.

Aged↗
PubMed2005

[Pathophysiology and rehabilitation of erectile dysfunction after nerve-sparing radical prostatectomy].

Radical prostatectomy is the current standard procedure for locally confined prostate cancer and accounts for the largest portion of invasive therapies. However, a major drawback of this approach remains the frequently ensuing postoperative erectile dysfunction. This aspect represents a frequent cause of fear and concern both for the patients and their partners and has a significant impact on the choice of therapy.After bilateral sparing of the neurovascular bundles, an average of 50% of the patients is likely to complain of erectile dysfunction. It is only in the course of the first 2 years after prostatectomy that rehabilitation of erectile dysfunction can be expected. It is all the more crucial to begin with rehabilitation therapy of the erectile tissue at an early postoperative stage to the prevent an irretrievable loss of erectile function. Application of PDE-5 inhibitors as well as prostaglandins, phentolamine, or papaverine can help to induce and to support penile blood perfusion and oxygenation, thus preserving structure and function of the corpora cavernosa. All efforts must be directed towards keeping the erectile function at the level ascertained prior to the intervention.

Clinical Trials as Topic↗
PubMed2005

[External genital injuries. Diagnostics and treatment].

This article reviews the current status of information on external male genital injuries, focusing on the causes as well as diagnostic and therapeutic management of this uncommon entity. Because of the high risk of infection and the major importance of preserving fertility, male genital injuries represent a serious urological disorder that demands immediate urological treatment. The diagnostic procedure classically consists of taking a history and inspecting the wound, which provides enough diagnostic information for the correct choice of conservative or surgical treatment. In most cases open injuries of the genitalia require surgical exploration to determine the extent of possible scrotal, testicular, epididymal, cavernous, or urethral damage, to débride nonviable superficial or deep tissue, to drain existing hematomas, or to control active bleeding. Furthermore, the correct therapeutic approach is crucial for preserving fertility and penile erection. In cases where bilateral ablation is necessary, measures to preserve sperm, e.g., testicular or microsurgical sperm extraction, or squeezing the ductus during orchidectomy must be considered.

Diagnostic Imaging↗
PubMed2005

[Pudendal nerve stimulation therapy of the overactive bladder -- an alternative to sacral neuromodulation?].

PURPOSE: Sacral neuromodulation is known to be an alternative therapeutic option for patients with anticholinergic resistant overactive bladder (OAB). For the same indication, a microstimulation system called BION is available since last year. The BION-stimulator, which only measures 2.8 x 0.3 cm, is designed for pudendal nerve stimulation. Its implantation technique as well as the first clinical results are presented and discussed. MATERIALS AND METHODS: During an outpatient percutaneous screening test (PST), a pudendal nerve stimulation is performed with a needle electrode in local anesthesia. A 50 % increase in the urodynamic parameters (bladder capacity, first desire to void, compliance, etc.) is an indication for a chronic implantation of the BION stimulator, which also can be placed in local anesthesia. RESULTS: Two patients have been treated with a BION-stimulator in our clinic so far. Patient I suffered from an OAB with frequent urinary incontinence and patient II had a sensory OAB with high voiding frequency. After the BION(R)-implantation, patient I showed a reduction in incontinence episodes by 31.5 % a day and patient II had lowered voiding frequencies from 12.6 to 7 a day. The postoperative urodynamic investigations confirmed these clinical results. CONCLUSIONS: The BION-system and chronic pudendal nerve stimulation seem to be alternatives to sacral neuromodulation, however, patient selection is difficult as subchronic stimulation for a longer period of time is not possible so far.

Aged↗
PubMed2004

[The aging bladder. anatomy and physiology].

Micturition disorders in elderly people result from the interaction between several different factors such as medication, mobility, metabolism and physical as well as psychological health. Senile incontinence may occur as a single form but is often a mixture of various forms. With increasing knowledge on the pathophysiology of incontinence, prevention and therapy may become more efficient. Age-dependent structural alterations to the urinary bladder are predominantly due to functional disturbances. Neurophysiological studies have led to modified recommendations for micturition behaviour other than double micturition in cases of residual urine or bladder over-expansion in the elderly. The brain, the main point of control of continence and micturition and a postmitotic organ, is very vulnerable to age-dependent disturbances. Research on cerebral organisation and control of continence, in addition to that on receptor-mediated and molecular-biological regulation processes, will have consequences for the health system and the action taken by the medical practitioner.

Aged↗
PubMed2004

[Micturition dysfunction triggered by spinal intramedullary neurocysticercosis].

INTRODUCTION: Neurocysticercosis is the most common parasitic disease of the human nervous system. This case report describes the rare intramedullary form of spinal neurocysticercosis. CASE REPORT: A 26-year-old male patient demonstrated sinistral brachialgia, arm paralysis and progressive disturbance of micturition with a weak urine stream and persisting residual urine. The cervical MRI revealed a large intramedullary space-occupying lesion in the spinal cord, which was excised. Histologically, parasitic structures were detected and the lesion classified as neurocysticercosis. Retrospectively, more detailed evaluation of the patient's medical history disclosed a number of subtle early neurological symptoms of the disease. The infection was probably acquired during a stay in South America 20 years earlier. The MRI revealed additional multiple small intramedullary lesions and a large lesion in the area of the conus medullaris, which could not be excised. The clinical course was partially dramatic and eventually resulted--apart from small neurological deficits--in complete failure of micturition due to a hyposensible, hypercontractile and instable detrusor muscle. In order for the patient to empty his bladder, sterile single catheterization under anticholinergic medication became necessary. CONCLUSIONS: Diagnosis of neurocysticercosis on clinical grounds is difficult, especially in regions like Europe, where the disease is very rare. In patients with non-specific neurological symptoms, and radiological indication of an intraspinal tumor, a history of stays in endemic regions even a long time ago, neurocysticercosis should be considered in the differential diagnosis as a possible cause.

Adult↗
PubMed2004

Male genital injury: diagnostics and treatment.

This article reviews the current status of information on external male genital injuries, focusing on cause, diagnostic and therapeutic management of this uncommon entity. Because of the high risk of infection and the major importance of preserving fertility, male genital injuries represent a serious urological disorder that demands immediate urological treatment. The diagnostic procedure classically consists of taking a history and inspecting the wound; this provides enough diagnostic information for the correct choice of conservative or surgical treatment. In most cases open injuries of the genitalia require surgical exploration to determine the extent of possible scrotal, testicular, epididymal, cavernosal or urethral damage, to debride nonviable superficial or deep tissue, to drain existing haematomas or to control active bleeding. Furthermore, the correct therapeutic approach is crucial for preserving fertility and penile erection. In cases where bilateral ablation is necessary, measures to preserve sperm, e.g. testicular or microsurgical sperm extraction, or squeezing the ductus during orchidectomy, must be considered.

Animals↗
PubMed2003

[Sacral neuromodulation in treatment of functional disorders of the lower urinary tract. An overview of basic principles, indications, outcomes].

Over the last few years, sacral neuromodulation has become an established treatment option for dysfunctions of the lower urinary tract. It fills the gap that used to exist between conservative therapy and costly invasive methods such as urinary drainage via a deactivated bowel segment. Initially, the clinical value of sacral neuromodulation was controversial even among neurourologists. This was mainly due to a lack of understanding of the physiological processes, uncertain diagnostics, the design of the hardware, and a surgical topography relatively unknown to the urologist. In the meantime, however, sacral neuromodulation has become a standard part of clinical routine with respect to the treatment of dysfunctions of the lower urinary tract, and it is regularly employed in various urological institutions across Europe and the USA. This form of treatment, which is the final straw for patients who believed themselves-after many frustrated therapy attempts-to be "hopeless cases," can now also successfully be employed as an ambulatory measure. The latest data from our hospital, as well as contributions presented at the last DGU Congress in Wiesbaden, indicate that patients with neurogenic urinary retention are the most likely to profit from this treatment option.

Electric Stimulation Therapy↗
PubMed2003

[Quality of life after surgical correction of penile deviation with the Schroeder-Essed plication].

PURPOSE: For the correction of congenital and acquired penile deviations, there are two established operative methods: the Nesbit procedure and the Schroeder-Essed technique. However, which operative method is optimal with respect to the specific underlying pathology, is still controversial. The aim of the study was to evaluate patient satisfaction retrospectively after modified Essed-Schroeder plication using quality of life questionnaires. MATERIAL AND METHODS: Between June 1997 and June 2000, 59 patients underwent Essed-Schroeder at our institution for correction of a penile deviation. Mean patient age was 40 years (18 - 71) and mean follow-up 30 months (19 - 36). A standardised questionnaire was sent to all patients. Of these, the questionnaires completed by 50 patients could be assessed as valid. RESULTS: Of these 50 patients, 22 suffered from a congenital penis deviation, 28 from Peyronie's disease. The percentage of patients who were able to perform sexual intercourse pre- and postoperatively was 62 % and 90 %, respectively. The proportion of patients who felt hampered during intercourse was reduced from 68 % to 48 %. Frequency of pain occurring during intercourse was diminished by half. Sixty percent of the patients would choose to have the same operation again, while 22 % were dissatisfied with the results. None of the patients showed complete erectile dysfunction after the operation. Seventy-four percent of the patients observed a decrease in penile length. CONCLUSIONS: In patients with Peyronie's disease, the Schroeder-Essed technique with tunica plicature leds to significant improvement in relatively few cases. Alternative methods, such as the Nesbit corporoplasty, appear to be superior in these patients. In cases of congenital penile deviation, however, where the aim is cosmetic correction under maximum protection of erectile function, the Schroeder-Essed tunica plicature has shown good results with regard to penile function and quality of life.

Adolescent↗
PubMed2003

[Tunica plication with horizontal incisions of the tunica albuginea in the treatment of congenital penile deviations].

PURPOSE: The Schroeder-Essed plication procedure is a standard technique for the correction of penile curvature. In a retrospective analysis we compared functional results and quality of life of the original technique with inverted sutures as described by Schroeder-Essed and our slight modification consisting of horizontal incisions into the tunica albuginea. MATERIALS AND METHODS: A total of 26 patients with congenital penile deviation were treated, 11 by the original Schroeder-Essed plication with inverted sutures and 15 using the described modification. In the modified technique, horizontal and parallel incisions 4 mm - 6 mm apart and about 8 mm - 10 mm long were made through the tunica albuginea. The outer edges of the incisions were then approximated with permanent inverted sutures (Gore-Tex(R) 3-0). Mean age was 21.6 years in the first group and 23.2 years in the second group. The preoperative penile deviation angle was > 25 degrees in all patients without differention between the two groups. RESULTS: All patients in both groups reported improvement in their quality of life and full ability to engage in sexual intercourse. A total of 9 patients (88 %) in the first group and 14 patients (93 %) in the second group were satisfied with the cosmetic result, although 10 patients (91 %) in the first and 13 patients (87 %) in the second group complained of penile shortening. Recurrence of deviation was only observed in 2-males in the first group (18 %). CONCLUSIONS: Our results indicate that this simple modification of the Schroeder-Essed plication offers good functional and cosmetic results. Most patients were satisfied with the penile angle correction results.

Adult↗
PubMed2002

Protease inhibitors are associated with a slowed progression of HIV-related renal diseases.

AIMS: While angiotensin-con-verting enzyme inhibitors and zidovudine may improve the course of the most common HIV-related renal disease, HIV-associated nephropathy (HIVAN), the effect of anti-retroviral combination therapy on this and other HIV-related renal diseases has not been assessed. This study describes the clinical course of HIV-related renal diseases and the effect of protease inhibitors on their progression. METHODS: This retrospective cohort study reviews the clinical course of 19 patients with a clinical or biopsy-proven diagnosis of HIVAN or other HIV-related renal diseases. Groups progressing and not progressing to ESRD were compared using longitudinal analyses to assess the association between creatinine clearance and clinical and therapeutic factors. RESULTS: The cohort consisted of 16 African-Americans, 2 Caucasians and 1 Native American. Their modes of HIV infection were intravenous drug use (7), a history of men having sex with men (3) and heterosexual behavior (5). Patients were followed for a median of 16.6 months. Seven patients reached ESRD. Loss of creatinine clearance over time did not differ among genders, races, or patients with different modes of HIV infection. Longitudinal analyses demonstrated an association between protease inhibitors and prednisone and a slower decline in creatinine clearance in multivariable models (p = 0.04 and 0.003, respectively). CONCLUSIONS: The epidemiology and clinical course of HIV-related renal diseases is more heterogeneous than previously described. This study suggests a benefit to the use of protease inhibitors and prednisone on the progression of these nephropathies.

AIDS-Associated Nephropathy↗
PubMed2001

Inconsistent reconstitution of cytomegalovirus-specific cell-mediated immunity in human immunodeficiency virus-infected patients receiving highly active antiretroviral therapy.

Cytomegalovirus (CMV)-immune recovery was characterized in human immunodeficiency virus (HIV)-infected patients receiving highly active antiretroviral therapy. CMV lymphocyte proliferation (LP), responder-cell frequency (RCF), and interferon (IFN)-gamma and interleukin (IL)-2 secretion were studied in CMV-seropositive HIV-infected patients and in CMV-seropositive HIV-uninfected control subjects. HIV-infected patients and control subjects had similar proportions of IL-2 and IFN-gamma, but levels were lower in HIV-infected patients. LP and RCF were significantly less frequent and of lower magnitude in HIV-infected patients. The measures of CMV cell-mediated immunity were correlated in HIV-uninfected but not in HIV-infected subjects. To investigate this, IL-2, IL-12, anti-CD28 plus anti-CD49d, or anti-IL-10 was added in vitro, with no effect on LP. However, CD8 cell depletion of mononuclear cells from HIV-infected patients increased LP responses to levels similar to those of uninfected control subjects; before depletion, only RCF correlated with CD4 cell counts, but after depletion, LP also correlated with CD4 cell counts.

AIDS-Related Opportunistic Infections↗