Dynamics of the upper urinary tract: II. The effect of variations of peristaltic frequency and bladder pressure on pyeloureteral pressure/flow relations

The dynamics of pyeloureteral flow is described when there is no peristalsis and for peristalsis of high and intermediate frequencies, on the assumption that the ureter is uniform except in the mid-ureter and at the outlet. The possibility of upstream transmission of bladder pressure variations to the renal pelvis is considered. The overall behaviour depends on three principal variables, the maximum tube pressure in the contraction waves, the intrinsic peristaltic carrying capacity and the peristaltic frequency f, expressed in the form fT where T is the time for a peristaltic contraction wave to sweep through the ureter. At intermediate peristaltic frequencies (fT less than but comparable with one) oscillatory flow patterns can occur, in which periods of peristaltically driven flow alternate with extraperistaltic periods of flow through the open ureter. The kidney is better isolated from bladder pressure variations when the peristaltic frequency is high, but high peristaltic frequency can by itself lead to elevated renal pelvic pressure if the flow rate is high. Experimental observations in pigs are presented to support these conclusions.     

人行走时骨盆上下运动参数的模型分析

为了研究正常人行走过程中骨盆在垂直方向的运动特征,提出了一种以测量数据为基础建立骨盆运动参数数学模型的新思想。介绍了基于跑步机的骨盆运动轨迹测量系统,并对30名健康男性青年进行了获取骨盆运动参数的实验研究。实验结果得到了不同受试者分别以不同速度行走时的骨盆在垂直方向的多组运动轨迹,以及运动幅值、周期、初始相位等与行走速度和受试者身高的关系曲线。通过对曲线拟合,建立了各参数及骨盆运动轨迹的数学模型。通过对该模型进一步完善,可使其对康复评定、类人机器人等领域具有一定的应用价值。     

Ring formation of the internal iliac artery

We observed an arterial ring communicating the superior and inferior gluteal arteries in the left half of the pelvis of an 88-year-old male. Although many previous studies have shown variations in the internal iliac artery, there has been no literature describing the fenestration. Therapeutic embolization is commonly performed for intractable bleeding in pelvic region. Surgeons should be aware of the arterial ring formation because of possible danger in the intravascular treatments. In patients with similar arterial rings, embolization of the anterior trunk of the internal iliac artery could be insufficient when blood runs through the circle of the arterial ring.     

腕关节软骨盘的生物力学和组织学实验研究

目的　对人体腕关节软骨盘进行生物力学和组织学实验研究,为该结构的劳损与运动性损伤及其防治提供相关依据。方法　对正常成年人腕关节软骨盘做组织学实验并对腕关节软骨盘试件进行压缩－扭转实验后进行组织学观察。结果　正常腕关节软骨盘属于纤维软骨;腕关节软骨盘各部位的纤维排列有一定差异,具有结构的功能性适应;软骨盘中血管丰富,未见神经分布;持续的压力、扭转力造成软骨盘组织细胞变形、软骨陷窝几乎消失;软骨盘内血管受损。结论　正常人的腕关节软骨盘组织学结构已有功能性适应,并有丰富血管供给营养。但过度的负荷,也会使组织结构发生变化,失去营养供应,出现疲劳性损伤。     

Variations in the pathway of the inferior gluteal nerve (author's transl)]

In 17 out of 112 subjects examined, the inferior gluteal nerve leaves the pelvis through the piriformis and passes to the gluteus maximus. In 3 of the subjects the variation occurs bilaterally, and in 7 cases each it is found on either the right or the left side of the body alone. This variation occurs more often in women than in men. In all cases observed the common peroneal nerve also leaves the pelvis through the piriformis. Aside from the common peroneal nerve, the entire posterior femoral cutaneous nerve, or only its dorsal ramus, often runs alongside the inferior gluteal nerve through the "foramen intrapiriforme". The origin of this variations has to be discussed in connection with the specific embryological development of the piriformis.     

Intra-abdominal pressure changes during natural movements in man

The weight of the upper part of the trunk is partially transmitted to the pelvis via the vertebral column. If the muscle walls around the abdominal cavity are contracted, a high pressure can be generated within the cavity (>200 mmHg). The abdominal space can then transmit part of the weight to, e.g., the upper part of the body. Intra-abdominal pressure recordings have been performed during locomotion and other natural movements with intragastric pressure recordings. With each step, there is a phasic variation in pressure, with its peak coinciding with that of the peak vertical force exerted by the leg against the ground. The peak values increase progressively with the speed of walking/running up to a mean of 38 mmHg and with trough values of 16 mmHg. The phasic variations with each step is due to a phasic activation of the abdominal muscles, with an EMG activity starting 50 ms or more before foot contact. If an extra load is put on the back, the posture changes and at the highest speed of running the pressure values are significantly higher than without this additional load. After a jump down from a moderate height of 0.4 m, the average increase is 89 mmHg and can often exceed 100 mmHg. These pressure changes are large and will presumably act to unload the spine under the prevailing biomechanical conditions and, in addition, there will no doubt be an effect on the circulatory system.     

Intra-abdominal pressure changes during natural movements in man.

The weight of the upper part of the trunk is partially transmitted to the pelvis via the vertebral column. If the muscle walls around the abdominal cavity are contracted, a high pressure can be generated within the cavity (greater than 200 mmHg). The abdominal space can them transmit part of weight to, e.g., the upper part of the body, Intra-abdominal pressure recordings have been performed during locomotion and other natural movements with intragastric pressure recordings. With each step, there is a phasic variation in pressure, with its peak coinciding with that of the peak vertical force exerted by the leg against the ground. The peak values increase progressively with the speed of walking/running up to a mean of 38 mmHg and with trough values of 16 mmHg. The phasic variations with each step is due to a phasic activation of the abdominal muscles, with an EMG activity starting 50 ms or more before foot contact. If an extra load is put on the back, the posture changes and at the highest speed of running the pressure values are significantly higher than without this additional load. After a jump down from a moderate height of 0.4 m, the average increase is 89 mmHg and can often exceed 100 mmHg. These pressure changes are large and will presumably act to unload the spine under the prevailing biomechanical conditions and, in addition, there will no doubt be an effect on the circulatory system.     

Leiomyosarcoma arising from the blind end of a bifid renal pelvis

Sarcoma of the kidney is a rare condition. Leiomyosarcoma is the most common of the kidney sarcomas. Renal leiomyosarcoma usually originates from the smooth muscle layers of the kidney, for example, the renal capsule and renal vessels. Renal pelvis neoplasms, however, are primarily transitional cell carcinomas, and renal pelvis leiomyosarcomas are extremely uncommon. Renal pelvis leiomyosarcoma has never been reported in Korea. Moreover, no more than 10 cases have been reported internationally. However, none of these were associated with kidney abnormalities. Here we describe a case of leiomyosarcoma that originated from the blind end of a bifid renal pelvis.     

Variations of pelvic anteversion in the lying and standing positions analysis of 24 control subjects and implications for CT measurement of position of a prosthetic cup

The position of the acetabular implant plays a dominant role in the displacement of a total hip prosthesis. CT allows precise measurement of the position of the cup, but the influence of pelvic rotation on this measurement is unknown. The aim of this study was to determine, in a group of healthy subjects, whether a pelvic equilibrium exists specific to each individual, and whether this is constant over time on the one hand and between the standing and lying positions on the other. The study concerned 15 men and 9 women with a mean age of 31 years. Each subject had strictly lateral radiographs of the pelvis, lying and standing, repeated at two different times. Pelvic version was measured in these radiographs. Each individual had a pelvic position constant over time, both in the lying and standing positions, However, there were important variations of the position of the pelvis during passage from the lying to the standing position 22 patients had retroversion of the pelvis by a mean of 7° (2-18°) and 2 others had an anteversion of 3°. These major variations of the pelvic position between the standing and lying positions explain why CT studies made in the lying position do not allow for the anteversion of the cup in the standing position, which is close to the dynamic situation during which displacement may occur. Thus, an excessive anteversion of the cup may be masked when the scan is made in the lying position, since in this position the anteversion of the pelvis leads to retroversion of the cup. The error may reach 20°, so that we recommend that CT measurements made without allowing for the position of the pelvis should be interpreted with caution.     

A case of paraneoplastic nephrotic syndrome in a patient with ovarian carcinoma

Nephrotic syndrome is a rare manifestation of malignancy associated with paraneoplastic syndrome. Paraneoplastic nephrotic syndrome has been reported in various malignancies: malignant lymphoma, colon cancer, lung cancer and prostate cancer. However, an ovarian carcinoma associated with nephrotic syndrome has rarely been reported. Only six cases of ovarian carcinoma associated paraneoplastic nephrotic syndrome has been reported worldwide, but no cases have been reported in Korea. Here, we report a case of paraneoplastic nephrotic syndrome in a patient with an ovarian carcinoma. The patient presented with ascites, proteinuria and hypoalbuminemia. An initial computed tomography (CT) scan and ultrasonography evaluations showed no specific findings suggestive of an ovarian tumor. Despite treatment for nephrotic syndrome, the symptoms became more aggravated. There after, follow up evaluation at Yonsei University Medical Center, including serum CA 125, pelvis MRI and peritoneal fluid examination were performed. On the pelvis MRI, a left ovarian mass was detected with an ascitic fluid collection. The serum CA 125 level was elevated to 2211 U/ml. The peritoneal fluid cytological examination showed malignant cells suggestive of an ovarian carcinoma. Combination chemotherapies including paclitaxel plus carboplatin, topotecan plus gemcitabine and oxaliplatin plus capecitabine were administered to the patient, and complete remission was achieved on image and tumor marker studies. There was complete recovery from the nephrotic syndrome with no evidence of ascites and proteinuria. These findings suggest that nephrotic syndrome caused by paraneoplastic syndrome can be resolved only after the complete control of the underlying malignancy.     

坐位骨盆的三维有限元分析

背景：由于骨盆具有复杂的结构,目前对于坐位骨盆的生物力学研究较少,有限元法日益成为骨盆生物力学研究的重要手段。 目的：以有限元法研究成人正常静态坐位骨盆应力分布。 方法：获取正常成年女性全骨盆CT扫描图像,利用CT数据通过Mimics 10.0对图像数据进行重建,利用Geomagic,Proe5.0进行实体建模,输入ANSYS。再根据解剖部位建立骨盆主要韧带。对S1椎体上终板施加600 N静载荷模拟坐位时骨盆受力环境,计算该加载方式下骨盆的应力、应变及位移的分布情况。 结果与结论：垂直加载600 N载荷于骶骨上表面时重力由骶骨经骶髂关节向下传递,到达坐骨结节。此时的坐骨结节处承受较大压应力。有限元模型在静载荷下的特征部位应力、应变值基本能够反应骨盆特有的力学结构特性,模型的准确性较高。计算结果与文献中报道的结果相近,建立的人体全骨盆三维有限元模型较客观地反映人体骨盆的解剖结构和力学特性,可作为骨盆生物力学研究的工具及满足临床研究的需要。     

Absence of a relationship between endometriosis and the N314D polymorphism of galactose-1-phosphate uridyl transferase in a UK population.

An association between the N314D polymorphism of galactose-1-phosphate uridyl transferase and endometriosis has recently been reported in a North American population. To determine whether such an association exists in the UK population, we genotyped 148 women with sporadic (n = 91) or familial (n = 57) endometriosis, a control population of 95 male blood donors and a control group of 53 women with a normal pelvis at hysterectomy. Heterozygosity for the polymorphism was found in 14.9% (22/148) of affected women, 13.7% (13/95) of male blood donors and 11.3% (6/53) of women with a normal pelvis. There was no statistically significant difference in the frequency of the polymorphism between cases and controls in the UK population, even when the cases were divided into groups of moderate-severe disease, sporadic cases or familial cases. We conclude that the galactose-1-phosphate uridyl transferase N314D polymorphism is unlikely to be associated with endometriosis in the UK population.     

Power spectral analysis of heart rate and blood pressure variability in anaesthetized dogs.

Short-term oscillation of heart rate and blood pressure are mainly regulated by the automatic nervous system. It has been proposed that non-neural factors, such as changes in intrathoracic pressure, can strongly modulate this rhythmicity. Our aim was to evaluate the effect of changing intrathoracic pressure and central autonomic nervous activity on heart rate and blood pressure variability. Evaluation was performed by using spectral analysis techniques with autoregressive modelling. The variability in heart rate and blood pressure remained in animals with open chest or paralysed respiratory muscles. After vagotomy, the variability in heart rate decreased, but not that of blood pressure. Total spinal anaesthesia elicited a decrease in the variability in blood pressure. The pharmacological blockade of alpha- and beta-receptors further decreased both variabilities. It was concluded that in anaesthetized dogs heart rate and blood pressure variability are mainly of central origin and non-neural factors have only minor effect on these central rhythms. High (> 0.15 Hz), medium (0.07-0.15 Hz) and, obviously low (0.00-0.07 Hz) frequency variations in heart rate are mostly mediated vagally. In blood pressure, medium and obviously low frequency variations are modulated by sympathetic nervous system, whereas high frequency variations are secondary to the heart rate variation.     

Urinary tract anomalies and dysfunctional voiding: a spectrum dictated by the influence of amniotic pressure upon fetal urodynamics

The etiologic basis of urinary tract anomalies and dysfunctional voiding largely remain unknown. However, the travel of urine from renal pelvis into the amniotic cavity under the pressures exerted by amniotic fluid satisfactorily explains the etiologic basis. Amniotic pressure is affected by the changes in maternal intraabdominal pressure. The intraabdominal pressure of the fetus is also dictated by the amniotic pressure. Amniotic pressure compresses the urethra throughout the length, and may increase both bladder leak point pressure and urethral resistance. Furthermore, the urine is propelled against amniotic pressure. These factors closely simulate outflow obstruction. Since the pressure within the bladder with minimal urine content reflects the intraabdominal pressure, intravesical pressure is also elevated during fetal life. Additionally, elevated intravesical pressures impair ureteral drainage. The compressive effect exerted by fetal intraabdominal pressure upon ureters, further elevate the pressure within the renal pelvis. While forwarding the urine against these pressures may result in anomalies of the urinary tract, the increased work load of the detrusor may act as a state of injury that forms the basis of dysfunctional voiding.     

Differential regulation of avian pelvic girdle development by the limb field ectoderm

Although limb development has been a subject of intense research over the last decades, development of the girdles has been poorly investigated. Particularly, a detailed analysis of pelvic girdle development including functional data is not available to date. Here, we describe the early steps of the formation of mesenchymal and cartilaginous anlagen of the pelvic elements using alcian blue staining in whole mount embryos and serial histological sections, and the expression pattern of several marker genes to provide an operative basis for further research in pelvis development. Moreover, we describe pelvis development after unilateral hindlimb bud amputation and somatopleural ectoderm extirpation. We show for the first time, that ectodermal signals at pre-limb bud stages are required for pelvis formation. We present evidence suggesting that the regulation of ilium development is different from the development of ischium and pubis.     

Detailed anatomy of the abdomen and pelvis of the visible human female

We report on a virtual anatomical preparation of the abdomen and pelvis of the Visible Human Female (VHF) for laparoscopic surgery training. The detailed cross-sectional image data set from the U.S. National Library of Medicine was used as the basis to build an exemplary model of the female abdomen and pelvis. Segmentation software was developed to delineate organ outlines and more than 300 structures of interest, including organs, blood vessels, bones, muscles, and ligaments, have been segmented and three-dimensionally reconstructed. Analyzing the normal anatomy we found several variations and pathologies of the VHF, such as missing muscles (gemellus superior, psoas minor), additional veins as well as spondylophytes (vertebral column, pubic bone), and colon diverticula. The complete data set may be viewed on the home page of the project (http://www.vision.ee.ethz.ch/projects/Lasso/start.html).     

Time and Spatial Invariance of Impedance Signals in Limbs of Healthy Subjects by Time–Frequency Analysis

The bioelectric impedance technique is a non-invasive method that provides the analysis of blood volume changes in the arteries. This is made possible by an interpretation of the impedance signal variations. In this paper, time and spatial variations of such impedance signals are studied on recordings made on limbs of 15 healthy subjects at rest. For that purpose, the scalogram of each signal has been computed and quantitative measures based on energies were determined. The results show that the signals are statistically time invariant on three anatomical segments of the limbs: pelvis, thigh and calf. p Value varies between 0.20 and 0.52 for the absolute energies computed on scalograms of signals recorded at 5 min intervals. Moreover, the analysis made on the two legs of each subject shows that the signals are spatial invariant on the three anatomical segments. p Value varies between 0.0785 and 1.000 for the absolute energies computed on the scalograms of signals recorded simultaneously on the two legs. These conclusions will therefore help the clinicians in studying the temporal variations of physiological parameters on limbs with the impedance technique. Moreover, the results on the spatial invariance make possible the comparisons of these parameters with those given by other acquisition techniques.     

A CT image based deterministic approach to dosimetry and radiography simulations

An integral transport equation based deterministic approach has been developed to compute individual specific absorbed dose distributions and photon flux distributions on a detector for image formation studies. An algorithm has been designed to take advantage of parallel processing platforms capable of processing large amounts of data imposed by the small pixel sizes of CT images. CT images have been used to form voxels that would represent both tissue variations and body geometry. Absorbed dose distributions calculated using the Visible Human dataset are provided.     

Human epidermal growth factor receptor 2 expression in urothelial carcinoma of the renal pelvis: correlation with clinicopathologic parameters

The significance of human epidermal growth factor receptor 2 (HER2) overexpression in breast cancer is well established, and these patients are subsequently treated with Trastuzumab. Although HER2 expression in urothelial carcinoma of the urinary bladder has also been recently characterized, it has not been well studied in urothelial carcinoma of the renal pelvis. We investigated the relationship between HER2 overexpression in urothelial carcinoma of the renal pelvis and clinicopathologic parameters. Forty six cases were identified. HER2 overexpression was present in 34/46 (74%) cases. Mean patient age with HER2 overexpression was 68 years (range: 42-87 years). There was a male predominance with 28/34 (82%) patients. High grade urothelial carcinoma was present in 32/34 (94%) cases and 2/34 (6%) cases had low grade urothelial carcinoma. Pathologic staging was as follows; 9/34 (26%) cases were pTa, 10/34 (29%) cases were pT1, 2/34 (6%) cases were pT2, 12/34 (35%) cases were pT3, and 1/34 (3%) cases was pT4. An inverted growth pattern was present in 23/46 (50%) cases. HER2 overexpression was present in 15/23 (65%) cases of urothelial carcinoma with an inverted growth pattern. Our study showed that HER2 overexpression is more common in male patients with high grade urothelial carcinoma, especially those with an inverted growth pattern. It is highly conceivable that patients with urothelial carcinoma of the renal pelvis may be further stratified based on HER2 overexpression, and may also be potential candidates for Trastuzumab therapy in the neoadjuvant or adjuvant setting.     

Bilateral malrotation and lobulation of kidney with altered hilar anatomy: a rare congenital variation

Variations of the structure and position of the kidney along with the variations of renal vessels are the most frequently reported. Rotational variations form a rare entity that is not cited in most of the embryology textbooks. During educational cadaveric dissection of a 57-year-old female, a complex picture of bilateral anatomical variants was encountered. Bilateral malrotation of kidney, bilateral lobulated kidneys along with open hilum of kidney was observed, so that the contents of the sinus were exposed. The renal pelvis was present anterior to the renal vessels instead of posterior position.