Biomedical subjects

Jochen Neuhaus

Publications and source records attributed to Jochen Neuhaus.

12 recordsLinked to original sources

PubMed2006

Anatomical landmarks of radical prostatecomy.

INTRODUCTION: In the present study, we review current literature and based on our experience, we present the anatomical landmarks of open and laparoscopic/endoscopic radical prostatectomy. METHODS: A thorough literature search was performed with the Medline database on the anatomy and the nomenclature of the structures surrounding the prostate gland. The correct handling of puboprostatic ligaments, external urethral sphincter, prostatic fascias and neurovascular bundle is necessary for avoiding malfunction of the urogenital system after radical prostatectomy. RESULTS: When evaluating new prostatectomy techniques, we should always take into account both clinical and final oncological outcomes. The present review adds further knowledge to the existing "postprostatectomy anatomical hazard" debate. It emphasizes upon the role of the puboprostatic ligaments and the course of the external urethral sphincter for urinary continence. When performing an intrafascial nerve sparing prostatectomy most urologists tend to approach as close to the prostatic capsula as possible, even though there is no concurrence regarding the nomenclature of the surrounding fascias and the course of the actual neurovascular bundles. After completion of an intrafascial technique the specimen does not contain any periprostatic tissue and thus the detection of pT3a disease is not feasible. This especially becomes problematic if the tumour reaches the resection margin. DISCUSSION: Nerve sparing open and laparoscopic radical prostatectomy should aim in maintaining sexual function, recuperating early continence after surgery, without hindering the final oncological outcome to the procedure. Despite the different approaches for radical prostatectomy the key for better results is the understanding of the anatomy of the bladder neck and the urethra.

Endoscopy↗

PubMed2006

Cultured smooth muscle cells of the human vesical sphincter are more sensitive to histamine than are detrusor smooth muscle cells.

OBJECTIVES: To compare histamine receptor expression in cultured smooth muscle cells from the human detrusor and internal sphincter using receptor-specific agonists. METHODS: Smooth muscle cells from the bladder dome and internal sphincter were cultured from 5 male patients undergoing cystectomy for bladder cancer therapy. Calcium transients in cells stimulated with carbachol, histamine, histamine receptor 1 (H1R)-specific heptanecarboxamide (HTMT), dimaprit (H2R), and R-(alpha)-methylhistamine (H3R) were measured by calcium imaging. Histamine receptor proteins were detected by Western blot analysis and immunocytochemistry. RESULTS: H1R, H2R, and H3R expression was found in tissue and cultured cells. Carbachol stimulated equal numbers of detrusor and sphincter cells (60% and 51%, respectively). Histamine stimulated significantly more cells than carbachol in detrusor (100%) and sphincter (99.34%) cells. Calcium responses to carbachol in detrusor and sphincter cells were comparable and did not differ from those to histamine in detrusor cells. However, histamine and specific agonists stimulated more sphincter cells than did carbachol (P <0.001), and the calcium increase was greater in sphincter cells than in detrusor cells. Single cell analysis revealed comparable H2R responses in detrusor and sphincter cells, but H1R and H3R-mediated calcium reactions were significantly greater in sphincter cells. CONCLUSIONS: Histamine very effectively induces calcium release in smooth muscle cells. In sphincter cells, histamine is even more effective than carbachol regarding the number of reacting cells and the intracellular calcium increase. Some of the variability in the outcome of antihistaminic interstitial cystitis therapies might be caused by the ineffectiveness of the chosen antihistaminic or unintentional weakening of sphincteric function.

Calcium↗

PubMed2006

Histamine receptors in human detrusor smooth muscle cells: physiological properties and immunohistochemical representation of subtypes.

The potent inflammatory mediator histamine is released from activated mast cells in interstitial cystitis (IC). Here, we report on the histamine receptor subtypes involved in the intracellular calcium response of cultured smooth muscle cells (cSMC). Fura-2 was used to monitor the calcium response in cSMC, cultured from human detrusor biopsies. The distribution of histamine receptor subtypes was addressed by immunocytochemistry in situ and in vitro. Histamine stimulated a maximum of 92% of the cells (n=335), being more effective than carbachol (70%, n=920). HTMT (H1R-agonist), dimaprit (H2R) and MTH (H3R) lead to significant lower numbers of reacting cells (60, 48 and 54%). Histamine receptor immunoreactivity (H1R, H2R, H3R, H4R) was found in situ and in vitro. Histamine-induced calcium increase is mediated by distinct histamine receptors. Thus, pre-therapeutic evaluation of histamine receptor expression in IC patients may help to optimize therapy by using a patient-specific cocktail of subtype-specific histamine receptor antagonists.

Calcium↗

PubMed2006

Histomorphology of canine urethral sphincter systems, including three-dimensional reconstruction and magnetic resonance imaging.

OBJECTIVES: To present a detailed anatomic description and comparison of the smooth and striated urethral sphincter in male and female dogs. We performed a thorough histologic evaluation, three-dimensional reconstruction, and magnetic resonance imaging of the lower urinary tract of male and female dogs. METHODS: The lower urinary tract anatomy was investigated in 16 male and 18 female dogs by serial sectioning, including immunohistochemical staining and three-dimensional reconstruction. Magnetic resonance imaging performed in 5 male and 5 female dogs before histologic investigation helped to demonstrate the anatomy in vivo. RESULTS: A urethral sphincter muscle in both sexes existed without muscular connection to the pelvic floor. It ran circularly and consisted of an inner smooth and outer striated muscular part. In the female dog, the striated muscle encircled the urethra and vagina in the caudal third of the membranous urethra (musculus urethrovaginalis). A urinary diaphragm (diaphragma urogenitale) could not be found histologically or by magnetic resonance imaging. CONCLUSIONS: The dog is a suitable animal model for investigations of the urethral sphincter. In the female dog, attention should be given to the special topography of the musculus urethrovaginalis.

Animals↗

PubMed2006

Quantitative immunohistochemical study of the innervation of the guinea-pig lower urinary tract.

OBJECTIVE: To study the innervation of the different muscle systems of the guinea-pig lower urinary tract, using immunohistochemical and enzyme histochemical methods. MATERIALS AND METHODS: Serial cryostat sections of both genders (four guinea-pigs each) were quantitatively analysed for cholinergic, adrenergic and peptidergic nerve fibre density using specific antibodies or enzyme histochemical labelling. Smooth muscle cell nuclei and varicosities or sectioned nerves were counted in detrusor, internal vesical sphincter (VS), ventral longitudinal musculature (VLM), and dorsal longitudinal musculature (DLM), and the ratios of nerves/nucleus (for detrusor, VLM and DLM) were evaluated statistically. The striated and the smooth external sphincter were examined qualitatively. RESULTS: Detrusor, VS, VLM and DLM had significantly different innervation patterns. In detrusor muscle parasympathetic nerve fibres dominated, while the VS and the urethral muscles had a major sympathetic nerve supply. Neuropeptide Y-positive nerve fibres were abundant in all of the muscles. CONCLUSIONS: Smooth muscles of the lower urinary tract of the guinea-pig are distinct muscular units with distinct innervation patterns. Although there are no corresponding studies in humans the general innervation seems to be equivalent in human and guinea-pig, qualifying the guinea-pig for comparative urological studies.

Animals↗

PubMed2005

Alterations in connexin expression in the bladder of patients with urge symptoms.

OBJECTIVE: To compare the formation of gap junctions between detrusor smooth muscle cells in situ and the distribution of connexin (Cx)40, Cx43 and Cx45 expressions in bladder biopsies from a control group (with bladder tumour) and from patients with urge symptoms, as smooth muscle cells of the human detrusor muscle communicate via gap junctions and express several connexin subtypes, alterations of which may be involved in the causes of lower urinary tract symptoms. MATERIALS AND METHODS: Connexin expression is prominent in myofibroblast-like cells, supposedly involved in afferent signalling pathways of the bladder. Their strategic position directly beneath the urothelium suggests they are a link between urothelial ATP signalling during bladder filling and afferent Adelta-fibre stimulation for co-ordination of bladder tonus and initialization of the micturition reflex. Modification of their coupling characteristics may have profound impact on bladder sensation. Bladder tissue probes of patients undergoing cystectomy or transurethral tumour resection for bladder cancer were used as controls. Tissue samples from patients with severe idiopathic urge symptoms were taken for exclusion diagnostics of interstitial cystitis (IC) and carcinoma in situ. The formation of functional syncytia between detrusor smooth muscle cells were examined in dye-coupling experiments by injecting with Lucifer Yellow. The morphology and structure of gap junctions were assessed by transmission electron microscopy and immunogold labelling of Cx43 and Cx45. The expression of connexin subtypes Cx40, Cx43 and Cx45 was compared by indirect immunofluorescence, and confocal laser scanning microscopy used for semiquantitative analysis. RESULTS: There was dye coupling between smooth muscle cells of the detrusor in situ. Electron microscopy and immunogold labelling showed very small gap junctional plaques. These findings were confirmed by confocal immunofluorescence. Semiquantitative analyses showed significantly higher Cx43 expression in the detrusor muscle, and a tendency to higher Cx45 expression in the suburothelial layer associated with urge symptoms, whereas Cx40 expression was unaffected. CONCLUSIONS: Smooth muscle cells of the human detrusor muscle are coupled by classical gap junctions, forming limited local functional syncytia. Both Cx43 and Cx45 are expressed at low levels in normal detrusor. Up-regulation of Cx43 in patients with urge incontinence supports the possibility of functional changes in the syncytial properties of detrusor smooth muscle cells in this condition. In addition, the observed increase of Cx45 in the myofibroblast cell layer supports the idea that alterations in sensory signalling are also involved. Comparison with previous reports implies that the pathophysiology of urgency is distinct from that of the unstable bladder and other forms of incontinence.

Aged↗

PubMed2004

Does the extraperitoneal laparoscopic approach improve the outcome of radical prostatectomy?

Laparoscopic radical prostatectomy (LRPE) became the operative procedure of choice for patients with clinically localized prostate cancer in selected urologic centers around the world. Principal advantages are the minimal invasive nature of the procedure, a superior visualization of the operative field because of the magnification of the optical system, an exact and watertight anastomosis, the possibility of early catheter removal, and a potentially reduced amount of blood loss. Recent data show that oncologic outcome is not compromised by the minimal invasive nature of the procedure. However, a major drawback of LRPE is the transperitoneal route of access to the extraperitoneal organ of the prostate. Therefore, principal disadvantages of LRPE are potential intraperitoneal complications. Endoscopic extraperitoneal radical prostatectomy is a further advancement of minimal invasive surgery because it overcomes the limitations of LRPE by the strictly extraperitoneal route of access, combining the advantages of minimal invasive surgery with the advantages of an extraperitoneal procedure. This article reviews the literature on minimally invasive (laparoscopic and endoscopic-extraperitoneal) radical prostatectomy.

Humans↗

PubMed2002

Smooth muscle cells from human urinary bladder express connexin 43 in vivo and in vitro.

Smooth muscle cells (SMC) of the human urinary bladder are believed to be electrically coupled. However, it has not been successfully demonstrated the nature of the underlying cell-cell communication. Here, we used Western blot technique to demonstrate the gap junction protein connexin 43 (Cx 43) in human bladder musculature and in smooth muscle cell cultures. We found expression of Cx 43 in all samples of the detrusor (Mdv, n=6) and in five of six samples of the internal sphincter (Mv). Cx 43 expression was less in cell cultures, 60% showing Cx 43 expression. Iontophoretic application of the gap junction permeable fluorescent dye lucifer yellow revealed a mean of 2.6+/-2.2 (mean+/-SD, n=8) coupled cells in cultured smooth muscle cells. Our findings support the notion that Cx 43 is constitutively expressed in human bladder SMC in vivo. Thus, the function of the bladder is likely to be influenced by the organisation of smooth muscle cells into functional syncytia.

Aged↗

PubMed2002

Detrusor smooth muscle cells of the guinea-pig are functionally coupled via gap junctions in situ and in cell culture.

Intercellular communication between smooth muscle cells is crucial for contractile behaviour in normal and pathologically altered urinary bladder. Since the study of coupling is difficult in situ, we established cell cultures of bladder smooth muscle cells to analyse coupling mechanisms. Microinjection of Lucifer yellow demonstrated syncytia composed of only a few to several dozen cells. Electron-microscopic examination of freeze-fracture specimens and ultrathin sections revealed that the dye-coupling was based on typical gap junction formation between the cultured smooth muscle cells. Furthermore, we were able to demonstrate gap junctions within the tissue fragments from which the primary cultures were grown. By Western blotting, we found connexin-43-positive protein bands both in native tissue probes from the guinea-pig urinary bladder and in smooth muscle cell cultures. Extracellular electrical stimulation of single cells evoked calcium transients, as visualized by fura-2 ratiofluorimetry. Calcium waves propagated throughout the syncytia with a declining amplitude, showing that the calcium signal was not regenerative. Therefore, the calcium signal was probably transmitted by a diffusible factor. These findings correlated well with the dye-coupling that we found between detrusor smooth muscle cells in situ. The use of smooth muscle cell cultures therefore seems to be a feasible approach for studying coupling behaviour in vitro.

Animals↗

PubMed2002

Muscle systems of the lower urinary tract of the male rhesus monkey (Macaca mulatta): histomorphology and 3-dimensional reconstruction.

PURPOSE: The structure and function of the lower urinary tract are still a subject of controversial discussion. Experiments in various animals, including rhesus monkeys, are often performed to improve the understanding of human physiology without adequate knowledge of anatomical differences. Therefore, a detailed study of the lower urinary tract of the male rhesus monkey (Macaca mulatta) was performed to elucidate anatomical correspondences in rhesus monkeys and humans. MATERIALS AND METHODS: Lower urinary tract anatomy and histomorphology were investigated in male rhesus monkeys on serial sections. To differentiate striated and smooth muscle immunohistochemical staining was done. Three-dimensional reconstructions were developed to demonstrate the topography of the muscle systems. RESULTS: We identified certain systems, including detrusor musculature extending on the bladder neck, a ventral longitudinal muscle system of the bladder neck, continuation of the musculature of the ureters to the verumontanum, a urethral sphincter consisting of a striated and a smooth muscle part, musculature between the urethra and rectum, and a striated longitudinal muscle system ventral to the urethral sphincter. The prostate gland of the rhesus monkey does not encircle the urethra but is attached dorsolateral. The internal sphincter (musculus sphincter vesicae) of humans does not exist in the rhesus monkey. The longitudinal systems of the urethra differ significantly from those in humans. CONCLUSIONS: Due to significant differences in lower urinary tract anatomy the suitability of the male rhesus monkey seems limited as an animal model for humans. It is not suitable for studying the longitudinal muscle systems of the human bladder neck.

Animals↗

PubMed2002

Is the male dog comparable to human? A histological study of the muscle systems of the lower urinary tract.

Because of their superficial anatomical resemblance, the male dog seems to be suitable for studying the physiologic and pathological alterations of the bladder neck of human males. The present study was carried out to compare and contrast the muscular anatomy of the male dog lower urinary tract with that of humans. The complete lower urinary tract, including the surrounding organs (bulb of penis, prostate, rectum and musculature of the pelvic floor) were removed from adult and newborn male dogs and histologically processed using serial section technique. Based on our own histological investigations, three-dimensional (3D)-models of the anatomy of the lower urinary tract were constructed to depict the corresponding structures and the differences between the species. The results of this study confirm that the lower urinary tract of the male dog bears some anatomical resemblance (musculus detrusor vesicae, prostate, prostatic and membranous urethra) to man. As with human males, the two parts of the musculus sphincter urethrae (glaber and transversostriatus) are evident in the canine bladder neck. Nevertheless, considerable differences in formation of individual muscles should be noted. In male dogs, no separate anatomic entity can be identified as vesical or internal sphincter. The individual course of the ventral and lateral longitudinal musculature and of the circularly arranged smooth musculature of the urethra is different to that of humans. Differences in the anatomy of individual muscles of the bladder neck in the male dog and man suggest that physiological interpretations of urethral functions obtained in one species cannot be attributed without qualification to the other.

Animals↗

PubMed2002

Sphincteric musculature of female canine urethra in comparison to woman including 3D reconstruction.

The circular arranged sphincteric musculature of bladder neck of female dogs and women were studied histomorphologically. 3D reconstructions of the anatomy of the bladder neck improve the understanding of construction principles of the musculature of the lower urinary tract and help to compare both species. Our own investigations based on 12 adult female canine and 15 female human autopsy preparations. The special feature of our study was the extensive en bloc preparation of all the organs of the lower urinary tract and surrounding organs. The organ blocks were reprocessed in complete serial sections from the bladder outlet down to the bulb of vestibuli. Despite different detailed construction, in both species the striated sphincter musculature of the urethra is an independent morphological unit. There is no continuation of pelvic floor muscles to the urethra. In humans, the urethral sphincter consists of a smooth muscular part (m. sphincter urethrae glaber) and a striated part (m. sphincter urethrae transversostriatus). In the female dog, striated muscle fibres encircle the urethra in the middle third exclusively. In the distal third of the urethra, it encircles the urethra and the vagina. In the female dog, the lamellae of detrusor continue directly to the urethra. Throughout the cranial and middle third of the urethra, smooth muscle cell bundles form a homogenous compact sphincteric muscle originating from the middle circular layer of detrusor. In that way, no true bladder neck sphincter according to the m. sphincter vesicae in women exists in dogs. According to the smooth muscular part of the m. sphincter urethrae in women, for this musculature the term m. sphincter urethrae glaber is suggested. Despite a superficial resemblance, this study revealed a considerable difference of circular sphincteric muscle components between female dog and woman suggesting that functional studies in respect to urinary continence obtained in dogs cannot be attributed without qualification to humans.

Animals↗