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PubMed2003

Temperature and ligand dependence of conformation and helical order in myosin filaments.

Mammalian myosin filaments are helically ordered only at higher temperatures (>20 degrees C) and become progressively more disordered as the temperature is decreased. It had previously been suggested that this was a consequence of the dependence of the hydrolytic step of myosin ATPase on temperature and the requirement that hydrolysis products (e.g., ADP.P(i)) be bound at the active site. An alternative hypothesis is that temperature directly affects the conformation of the myosin heads and that they need to be in a particular conformation for helical order in the filament. To discriminate between these two hypotheses, we have studied the effect of temperature on the helical order of myosin heads in rabbit psoas muscle in the presence of nonhydrolyzable ligands. The muscle fibers were overstretched to nonoverlap such that myosin affinity for nucleotides was not influenced by the interaction of myosin with the thin filament. We show that with bound ADP.vanadate, which mimics the transition state between ATP and hydrolysis products, or with the ATP analogues AMP-PNP or ADP.BeF(x)() the myosin filaments are substantially ordered at higher temperatures but are reversibly disordered by cooling. These results reinforce recent studies in solution showing that temperature as well as ligand influence the equilibrium between multiple myosin conformations [Málnási-Csizmadia, A., Pearson, D. S., Kovács, M., Woolley, R. J., Geeves, M. A., and Bagshaw, C. R. (2001) Biochemistry 40, 12727-12737; Málnási-Csizmadia, A., Woolley, R. J., and Bagshaw, C. R. (2000) Biochemistry 39, 16135-16146; Urbanke, C., and Wray, J. (2001) Biochem. J. 358, 165-173] and indicate that helical order requires the myosin heads to be in the closed conformation. Our results suggest that most of the heads in the closed conformation are ordered, and that order is not produced in a separate step. Hence, helical order can be used as a signature of the closed conformation in relaxed muscle. Analysis of the dependence on temperature of helical order and myosin conformation shows that in the presence of these analogues one ordered (closed) conformation and two disordered conformations with distinct thermodynamic properties coexist. Low temperatures favor one disordered conformation, while high temperatures favor the ordered (closed) conformation together with a second disordered conformation.

Adenosine Diphosphate↗
PubMed1997

Inhibition of mitochondrial calcium uptake slows down relaxation in mitochondria-rich skeletal muscles.

Isolated fibres from various muscles were skinned mechanically in oil. From a Ca2+-loaded micropipette, local applications of Ca2+ were made. These produced a limited contraction which relaxed spontaneously. The time-course of sarcomere shortening and re-lengthening was recorded by microcinephotography. Application of Ruthenium Red, a potent and specific inhibitor of Ca2+ uptake by mitochondria, did not affect the contraction-relaxation cycles of typical glycolytic white fibres (frog sartorius, pigeon breast). By contrast, Ruthenium Red greatly slowed down the relaxation rate in mitochondria-rich fibres (rat soleus and rabbit masseter). In these fibres, Ca2+ uptake by mitochondria seems to play an active role in promoting relaxation.

Animals↗
PubMed2002

A rare co-existence of focal xanthogranulomatous pyelonepheritis, angiomyolipoma and renal cysts simulating renal cell carcinoma.

A 70-year-old male presented with left flank pain and history of gross, total painless haematuria of 6 months duration. Investigations revealed a large solid and cystic mass suggestive of renal cell carcinoma in left kidney with possible infiltration of left psoas muscle. Histology of radical nephrectomy showed angiomyolipoma with multiple cysts lined by columnar epithelium suggestive of tuberous sclerosis and focal area of xanthogranulomatous pyelonepheritis. The rare combination of such lesions leading to diagnostic dilemma has not been reported in medical literature to the best of our knowledge.

Aged↗
PubMed2006

[Sonography of acute appencitis and the main differential diagnoses].

Today sonography is the first line imaging method for diagnosing acute appendicitis. Experienced investigators will have an accuracy of more than 90%. Sonography can diagnose many conservatively managed diseases. The most important differential diagnoses are infectious ileocoecitis, right sided diverticulitis, appendagitis, adnexitis, ruptured or torque ovarian cysts, ectopic pregnancies. Ureterolithiasis, cholecystitis, haematomas in the psoas muscle or in the rectus muscle are rarer causes of right lower quadrant pain. Sonography can reduce the high rate of false positive clinical examinations concerning acute appendicitis. It has to be stated that an exclusion of appendicitis can only be made sonographically if the normal appendix can be seen in its full length and/or an other differential diagnosis can be depicted that explains the clinical symptoms. Mucoceles are rare cystoid lesions of the appendix. They exhibit a typical onion skin sign structure caused by different mucus viscosities. In large mucoceles a tumor causes this lesion.

Acute Disease↗
PubMed1990

Peptide mimetics of an actin-binding site on myosin span two functional domains on actin.

The sites on the myosin heavy chain that interact with actin and are responsible for force generation are ill-defined: crosslinking and experiments with isolated domains of the myosin head implicate regions in both the 50K and 20K (molecular weights in thousands) domains of the myosin head (subfragment 1, S1) in this process. We have synthesized peptides from the sequence around the fast-reacting SH1 thiol residue in the 20K domain of S1 in order to delineate precisely an actin-binding site. We used a combination of 1H-NMR and enzyme inhibition assay and also assessed the effects of peptides on skinned rabbit psoas muscle fibres to show that the region of amino acids 690-725 contains an actin-binding site. Peptides from this region bind to actin, act as mixed inhibitors of the actin-stimulated S1 Mg2(+)-ATPase, and influence the contractile force developed in skinned fibres, whereas peptides flanking this sequence are without effect in our test systems. Remarkably, peptides from the N-terminal half of this segment 690-725 increase force development in skinned fibres at submaximal activating concentrations of Ca2+, that is, they behave as calcium-sensitizers; C-terminal peptides, however, inhibit force development without effecting sensitivity to calcium. These different responses indicate that this region is probably binding at two functionally distinct sites on actin.

Actins↗
PubMed1984

Pathophysiological changes in rat kidneys with partial ureteral obstruction since infancy.

A partial ureteral obstruction (PUO) was created in 5-day-old rats by implanting the left ureter in the psoas muscle. The surgical technique was modified to produce mild or severe hydronephrosis [Hn (m) and Hn (s)]. The rats were studied at ages between 45 and 65 days with regard to kidney weight, number of functioning glomeruli, mean arterial blood pressure (MAP), total glomerular filtration rate (GFR), nephron filtration rate (SNGFR), tubular free-flow pressure (PT, and stop-flow pressure (SFP). Total GFR was determined after the release of obstruction. The other studies were performed in the obstructed state. Reference values were obtained from sham-operated and untouched control rats. The number of functioning nephrons was depressed 38% in Hn (m) and 73% in Hn (s). Total GFR was preserved in Hn (m) and depressed 54% in Hn (s). SNGFR in the remaining nephrons was significantly elevated in Hn (m) and normal in Hn (s). SFP was significantly elevated in Hn (s). The Hn (s) rats were hypertensive. The glomerular density was lower in the hydronephrotic than in the contralateral kidneys. This suggests a compensatory growth of the remaining nephrons in the Hn kidneys. We conclude that PUO present since infancy will either destroy the nephrons or elicit an adaptive response that will tend to preserve GFR.

Aging↗
PubMed1993

Collagen studies in newborn rat kidneys with incomplete ureteric obstruction.

Collagen studies in newborn rats with incomplete ureteric obstruction were performed to describe and quantify changes in collagen deposition resulting from urinary tract obstruction at an early developmental age. Incomplete ureteric obstruction was created in three-day-old rats by placing the left ureter in a tunnel formed by the psoas muscle, and sham-operated controls underwent a laparotomy. The rats were sacrificed at 10, 17, 24 or 31 days. Collagen types I, III, IV, and V were localized by indirect immunofluorescence microscopy, the total collagen content of the kidney was quantitated using hydroxyproline analysis, and collagen types I and III were quantitated using cyanogen bromide (CNBr) peptide analysis. Increased immunofluorescent staining for all of the collagens was found in the diffusely widened medullary interstitium of the obstructed kidney, and more focally in the cortical interstitium. Collagen types I, III and V, but not collagen type IV, were also found in bands in the interstitium at the junction of the cortex with the medulla. Increased staining for collagen type IV was found in thickened and tortuous tubular basement membranes (TBM) of the obstructed kidneys. The total collagen content of the obstructed kidney was significantly increased compared to the amounts in both the contralateral kidneys and in the kidneys from sham-operated controls at 24 and 31 days of age (P < 0.01 in each case, Wilcoxon matched pairs rank sum test and Mann Whitney U-test, respectively). The amount of collagen in the kidneys correlated with the degree of hydronephrosis (Spearman correlation test, r = 0.78, P < 0.02). CNBr peptide analysis demonstrated that over 50% of the collagen in the normal neonatal rat kidney was collagen type I and approximately 25% was collagen type III. In the obstructed kidneys most of the collagen was also collagen type I and collagen type III, although the proportion of total collagen comprised by these collagen types was decreased compared with the controls. The amount of collagen type III in the contralateral kidneys was reduced compared to that in the controls. Thus, the neonatal renal response to obstruction resulted in increased amounts of a range of collagens in the interstitium and TBM, and the extent of this response was partially related to the degree of hydronephrosis.

Animals↗
PubMed2006

Spinal cord compression of primary extragonadal giant yolk sac tumor.

STUDY DESIGN: Case report. OBJECTIVE: To report an adult male patient with a primary extragonadal giant yolk sac tumor presenting with acute spinal cord compression. SETTING: Faculty of Medicine, University of Dicle, Diyarbakir, Turkey. METHOD: A 31-year-old man was referred to our department with a diagnosis of Pott's disease, a complaint of back pain and gait difficulty for 2 weeks. Neurological examination showed spastic paraparesis and hypoesthesia below the L2 dermatome level. He also had urinary incontinence. Abdominal computed tomography and lumbar magnetic resonance imaging study revealed a giant cystic mass lesion located in the psoas muscle. Posteriorly, the third lumbar vertebral body was destructed and the tumor was compressing the dural sac. A combined anterior and posterior approach was performed. Pathological diagnosis was a yolk sac tumor. RESULT: His neurological status improved during the postoperative course. A chemotherapy protocol was given including bleomycin, etoposide and cisplatin. Five months after the last chemotherapy, he was brought to the emergency unit in sepsis and died despite antibiotherapy. CONCLUSION: Yolk sac tumor should be considered in young adult male patients presenting with acute paraparesis even without any signs or medical history of a testis tumor. These tumors may be unresectable; however, decompression of neural structures and stabilization of the spine with instrumentation may cause substantial improvement in neurological deficit and pain relief.

Adult↗
PubMed1974

Mechanism of activation of pyruvate dehydrogenase by dichloroacetate and other halogenated carboxylic acids.

1. Monochloroacetate, dichloroacetate, trichloroacetate, difluoroacetate, 2-chloropropionate, 2,2'-dichloropropionate and 3-chloropropionate were inhibitors of pig heart pyruvate dehydrogenase kinase. Dichloroacetate was also shown to inhibit rat heart pyruvate dehydrogenase kinase. The inhibition was mainly non-competitive with respect to ATP. The concentration required for 50% inhibition was approx. 100mum for the three chloroacetates, difluoroacetate and 2-chloropropionate and 2,2'-dichloropropionate. Dichloroacetamide was not inhibitory. 2. Dichloroacetate had no significant effect on the activity of pyruvate dehydrogenase phosphate phosphatase when this was maximally activated by Ca(2+) and Mg(2+). 3. Dichloroacetate did not increase the catalytic activity of purified pig heart pyruvate dehydrogenase. 4. Dichloroacetate, difluoroacetate, 2-chloropropionate and 2,2'-dichloropropionate increased the proportion of the active (dephosphorylated) form of pyruvate dehydrogenase in rat heart mitochondria with 2-oxoglutarate and malate as respiratory substrates. Similar effects of dichloroacetate were shown with kidney and fat-cell mitochondria. Glyoxylate, monochloroacetate and dichloroacetamide were inactive. 5. Dichloroacetate increased the proportion of active pyruvate dehydrogenase in the perfused rat heart, isolated rat diaphragm and rat epididymal fat-pads. Difluoroacetate and dichloroacetamide were also active in the perfused heart, but glyoxylate, monochloroacetate and trichloroacetate were inactive. 6. Injection of dichloroacetate into rats starved overnight led within 60 min to activation of pyruvate dehydrogenase in extracts from heart, psoas muscle, adipose tissue, kidney and liver. The blood concentration of lactate fell within 15 min to reach a minimum after 60 min. The blood concentration of glucose fell after 90 min and reached a minimum after 120 min. There was no significant change in plasma glycerol concentration. 7. In epididymal fatpads dichloroacetate inhibited incorporation of (14)C from [U-(14)C]glucose, [U-(14)C]fructose and from [U-(14)C]lactate into CO(2) and glyceride fatty acid. 8. It is concluded that the inhibition of pyruvate dehydrogenase kinase by dichloroacetate may account for the activation of pyruvate dehydrogenase and pyruvate oxidation which it induces in isolated rat heart and diaphragm muscles, subject to certain assumptions as to the distribution of dichloroacetate across the plasma membrane and the mitochondrial membrane. 9. It is suggested that activation of pyruvate dehydrogenase by dichloroacetate could contribute to its hypoglycaemic effect by interruption of the Cori and alanine cycles. 10. It is suggested that the inhibitory effect of dichloroacetate on fatty acid synthesis in adipose tissue may involve an additional effect or effects of the compound.

Acetamides↗
PubMed2004

Magnetic resonance screening of iron status in transfusion-dependent beta-thalassaemia patients.

The clinical utility of dual sequence (T1- and T2-weighted) magnetic resonance (MR) imaging in estimating liver iron concentration (LIC) in 32 transfusion-dependent beta-thalassaemia major (24 females; age 18.5+/-5.9 years) patients on desferrioxamine was evaluated. Signal intensity ratios (SIR) between liver, spleen and pancreas to psoas muscle were determined on both sequences. Relationships between clinical and MR parameters, and accuracy of SIR thresholds in determining adequacy of chelation from LIC were analysed. Liver T1- and T2-SIR were related to LIC (P < 0.001). T1-SIR < 0.60 predicted severe iron overload (LIC > 15 mg/g) with sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 100%, 87%, 33% and 100% respectively. T2-SIR < 0.1 yielded 100% sensitivity, 93% specificity, 50% PPV and 100% NPV. T1-SIR > or = 1.1 predicted LIC < 7 mg/g with 69% sensitivity, 88% specificity, 85% PPV and 74% NPV. T2-SIR > or = 0.20 yielded 56.5% sensitivity, 94% specificity, 90% PPV and 71% NPV. LIC correlated with liver T1-SIR, liver T2-SIR and serum ferritin (r = -0.76, -0.65, 0.47, respectively; P < 0.01). Serum ferritin was inversely related to liver T1-SIR, liver T2-SIR and spleen T2-SIR (r = -0.35, -0.43, -0.40, respectively; P < 0.05). Mean total transfusion burden was not related to any MR parameter. Although neither MR sequence was a highly accurate predictor of LIC, SIR thresholds are useful to determine presence of iron overload and adequacy of chelation treatment.

Adolescent↗
PubMed2003

An acquired factor VIII inhibitor in association with a myeloproliferative/myelodysplastic disorder presenting with severe subcutaneous haemorrhage.

We report a 71-year-old man who presented with severe subcutaneous and later psoas muscle haemorrhage in the presence of a raised white cell count and hepatosplenomegaly. A circulating factor VIII (FVIII) inhibitor was detected and bone marrow morphology confirmed the presence of a myeloproliferative/myelodysplastic disorder. Initial treatment with high dose FVIII followed by recombinant factor VIIa was unsuccessful. Haemorrhage was controlled by the administration of activated prothrombin complex concentrate (FEIBA; Baxter healthcare, CA, USA) in combination with prednisolone, cyclophosphamide and i.v. immunoglobulin. The inhibitor became undetectable 14 weeks after presentation. The white cell count responded initially to hydroxyurea and later to cyclophosphamide. There have been only two previous reports of acquired haemophilia A in association with myelodysplastic disorders and no previous report of an association with a myeloproliferative disorder.

Aged↗
PubMed2001

Retroperitoneoscopic ureterolithotomy for impacted ureteral stone.

Retroperitoneoscopic ureterolithotomy was successfully performed in two patients with impacted upper ureteral stone. The retroperitoneal space was extended using a balloon dissector and four ports were established into the retroperitoneal space according to Gaur's procedure (1993). The impacted ureteral stone was removed after the ureter was incised using a hook electrode. An indwelling splint or stent was placed in the ureter. The incised ureter was not sutured and an indwelling drain was placed in the retroperitoneal space. Urine leakage ceased within 3 days postoperatively. With regard to complications, the first patient developed wound infection caused by methicillin-resistant Staphylococcus aureus and the second patient had abscess formation in the psoas muscle. Retroperitoneoscopic ureterolithotomy should be useful as an alternative treatment for impacted ureteral stones because it involves minimal postoperative pain.

Aged↗
PubMed2002

Severe partial ureteric obstruction in newborn rats can produce renal dysplasia.

OBJECTIVE: To investigate whether partial unilateral ureteric obstruction (PUUO) produces renal dysplasia in newborn rats. MATERIALS AND METHODS: Left mild (in 31) or severe (in 34) PUUO was induced in 2-day-old rats by embedding a quarter or two-thirds of the ureter into the psoas muscles, respectively. Sham-operated control rats (36) were assessed in parallel. Kidney morphology, renal parenchymal weight and histology were examined 24 weeks and 30 months afterward. RESULTS: There was significant pelvic dilatation in all obstructed kidneys; four kidneys were dysplastic in those severely obstructed, with a significant decrease in renal volume. There were three dysplastic kidneys after 6 months and one at 30 months. The in vitro dysplastic kidney weight was 36% of the control kidneys. Microscopy showed primitive glomerular and tubular structures, with renal parenchymal developmental disorganization and marked fibrosis. The glomeruli, tubules and collecting ducts were deficient in number and had often undergone cystic changes. Columnar tubular epithelium and peritubular mesenchymal collars were present. There was no renal dysplasia in the mildly obstructed and sham-operated rats. The parenchymal weight of the kidneys contralateral to the dysplastic kidneys was significantly higher than in the controls (P < 0.001). CONCLUSIONS: Severe PUUO can produce renal dysplasia in newborn rats. However, only 12% with severe obstruction had renal dysplasia, indicating that the cause of renal dysplasia might also be related to other factors.

Animals↗
PubMed2001

Fatal emphysematous pyelonephritis with gas in the spinal extradural space in a patient with diabetes.

BACKGROUND: Emphysematous pyelonephritis (EP) is a rare but life-threatening condition of the upper urinary tract, characterized by the presence of gas in the renal parenchyma and perirenal space. The vast majority of patients with EP (90%) are known to have diabetes, with Escherichia coli being the most common causative pathogen. CASE REPORT: We present a case of fatal bilateral EP in a patient with diabetes, with an unusual radiological finding of gas around the spinal cord and in the psoas muscle, with renal parenchymal sparing. Our case serves as an important reminder of this life threatening entity in diabetic patients, which is not well recognized by clinicians because of its rarity.

Diabetes Mellitus, Type 2↗
PubMedDate not supplied

Effect of simple omentoplasty and omentopexy in the prevention of complications after pelvic lymphadenectomy.

This multicenter collaborative study prospectively evaluated the effect of omentoplasty and omentopexy on the prevention of complications after pelvic lymphadenectomy. Sixty-four consecutive patients (42 cervical and 22 endometrial cancer) were enrolled and examined periodically for 12 months. All patients underwent simple, semiradical, or Okabayashi's radical hysterectomy and complete pelvic lymphadenectomy. The infracolic omentum was longitudinally divided in half and omentoplasty was performed so that bilateral omental flaps would reach the pelvic floor. The omental flaps were inserted into the retroperitoneal space and the edges of the flaps were sutured to the psoas muscle. The omental flap was then covered by the peritoneum. Incidence of lymphocele, lymphedema, and severe complications associated with lymphocele, such as infection or urinary stenosis, was evaluated at intervals for at least one year after surgery. Among the 64 patients, 12 patients received pelvic radiation because of occult lymph node metastasis. Planned omentoplasty was not possible in one patient because her omentum was too small; therefore, only unilateral omentopexy was performed. Asymptomatic lymphoceles only were detected by ultrasonogram in 12 patients (18.8%). Three patients (4.7%) had a symptomatic but pressure-only lymphocele. Hydronephrosis and bladder compression probably due to lymphocele were observed in one patient, respectively (3.1%), but resolved within 6 months. Lymphedema was observed in seven patients (10.9%) and persisted for more than 6 months in two patients (3.1%). We conclude that this simple technique of omentoplasty and omentopexy appeared to be effective in reducing the incidence of complications after pelvic lymphadenectomy.

Adult↗
PubMed2001

Xanthogranulomatous pyelonephritis in childhood.

PURPOSE: Demographic data, clinical presentation, associated abnormalities, and radiologic findings were evaluated to outline diagnostic criteria that may lead to the diagnosis of xanthogranulomatous pyelonephritis in children. METHODS: Eleven boys and 8 girls with a mean age of 3.4 +/- 1.7 years were classified into obstructive xanthogranulomatous pyelonephritis (n = 13), which was associated with nephrolithiasis and nonobstructive (n = 6), which mimicked Wilms' tumor. RESULTS: Twelve children with obstructive diffuse involvement of the renal parenchyma, 1 with left-sided obstructive focal involvement in a horseshoe kidney (group 1), and 6 with nonobstructive diffuse xanthogranulomatous pyelonephritis (group 2) showed a male to female ratio of 1.2:1 and 2:1, respectively. Mean age was 4.1 +/- 1.2 years in group 1 versus 1.8 +/- 1.5 years in group 2; P =.001. The common features were renal mass, hematuria, and anemia (100%; P =.07) and leucocytosis (77% v 83%; P =.097). Main differences between the 2 groups were acute inflammatory syndrome (0 v 33%; P =.01), recurrent urinary infection (54% v 17%; P =.05), isolation of Proteus mirabilis as a pathogen (69% v 0; P =.001), and renal stones (100% v 0; P =.001). Preoperative diagnosis was accurate in all 13 (100%) children with obstructive xanthogranulomatous pyelonephritis. Radiologic features that were not consistent with Wilms' tumor in group 2 were absence of sharp definition and encapsulation of the mass, ill-defined margins with inflammatory infiltration of the perinephric fat and focal inflammatory tissue destruction. Nephrectomy was technically difficult because of extensive adhesions to the retroperitoneum, psoas muscle, and surrounding structures in both groups. CONCLUSIONS: Xanthogranulomatous pyelonephritis must be considered in the differential diagnosis of a child presenting with a renal mass, anemia, and elevated inflammatory markers. Treatment by nephrectomy is curative. J Pediatr Surg 36:598-601.

Age Distribution↗
PubMed2002

[Comparison of flat-panel radiography and computed radiography in urography].

PURPOSE: To evaluate the diagnostic value of digital flat-panel radiography in uroradiology the i. v. urograms of patients who had been examined with computed radiography and digital flat-panel radiography were compared regarding image quality. METHODS: 50 patients who underwent clinically indicated i. v. urography were examined with digital flat-panel radiography and computed radiography. In order to avoid unnecessary double exposure to X-rays, patients were examined either by flat-panel or computed radiography before injection of contrast media. Each further clinically indicated exposure after administration of contrast media was done by alternating the other examination technique. The digital images were compared by 4 radiologists regarding image quality for the detection of defined anatomic structures. RESULTS: Digital flat-panel radiography showed an image quality of the liver, spleen and both kidneys that was similar to computed radiography. The urinary tract, lumbar spine, pelvis and psoas muscle were significantly better visible on flat-panel radiography images. CONCLUSIONS: Compared to computed radiography there is no loss of image information by using digital flat-panel radiography in uroradiology. On the contrary, some anatomic structures on abdominal survey images show better image quality. In conclusion, digital flat-panel radiography has the potential to replace computed radiography in uroradiologic examinations.

Contrast Media↗
PubMed2004

Effects of artificial obstruction on the function of the upper urinary tract of Guinea pigs, rats and pigs.

PURPOSE: Four different experiments in animals were performed to evaluate the influence of pyelo-ureteral surgery on the function of the upper urinary tract. METHODS: Experiment I: In 17 female guinea pigs pyelo-ureteral anastomosis was performed microsurgically. Three months later, the ureteral peristalsis was investigated by measuring the intraureteral pressure and the in vitro activity of the renal pelvic and ureteric wall was analysed. Experiment II: 10 rats were used for microsurgical uretero-ureteral anastomosis. One month after surgery the pyelo-ureteral peristalsis was examined by videomicroscopy while simultaneously measuring the renal pelvic and intravesical pressure. Subsequently the kidneys were removed for histological examination. Experiment III: In 2 pigs unilateral pyeloplasty was performed. Using an implanted transmitter the intravesical and the renal pelvic pressures were recorded continuously over a time interval of 3 months. Five months after surgery the pyelo-ureteral peristalsis was investigated by pyelography. The kidneys were then removed for histological and biomechanical examinations. Experiment IV: A partial artificial obstruction was performed in 16 guinea pigs by implanting the ureter into the psoas muscle. Two to six months following surgery their upper urinary tracts were removed for analysis of in vitro activity as well as histological and immunohistochemical investigations of the ureter and renal pelvis. RESULTS: Experiment I: Ultrasound investigation showed in all cases a significant dilation of the renal pelvis. The ureteral contraction frequency distally was decreased in vivo as well as in vitro (p <0.05) compared with the controls. Experiment II: Videomicroscopic imaging showed in eight out of nine cases an interruption of the peristaltic wave below the anastomosis; the ureteral peristalsis was restored distally by ureteral contractions with a decreased frequency. Retroperistalsis was seen in the lower part of the ureter. The frequency of renal pelvic and ureteral contractions were decreased (p <0.05). Renal pelvic baseline pressure as well as contraction amplitude were irregularly changed. Histological examinations showed increased connective tissue within the renal pelvic wall in all cases. Experiment III: In both pigs an intermittent change in contraction frequency of the renal pelvis was found, associated with a changing contraction amplitude. Five months after surgery an interruption of the peristaltic wave was detected in both pigs. Histological examinations showed increased connective tissue within the renal pelvic wall. The stiffness of caliceal and pelvic tissue was lower following the pyeloplasty compared to the controls. Experiment IV: Following artificial partial ureteral obstruction in all guinea pigs the in vitro investigations showed an increased spontaneous activity of the upper urinary tract except in the proximal part of the ureter. Ureteral obstruction produced a change in contraction pattern of the proximal ureter and a decrease in contraction frequency of the distal ureter. Immunohistochemical investigations revealed rarefication and disorientation of nerve fibres within the proximal ureteric wall. CONCLUSIONS: Surgical interruption of the ureteral continuity and re-anastomosis cause a temporary disruption of the peristaltic wave at the anastomosis site. Ureteral peristalsis is restored by ureteral contractions associated with retroperistalsis as well as a decreased contraction frequency. Uretero-ureteral anastomosis in rats, pyelo-ureteral anastomosis in guinea pigs and pyeloplasty in pigs seem to influence the upper urinary tract similarly to a chronical functional obstruction, causing changes in pyelo-ureteral motility and spontaneous muscular activity of the renal pelvic and ureteral wall as well as biomechanical and histological characteristics.

Anastomosis, Surgical↗