HDL3-mediated cholesterol efflux from cultured enterocytes: the role of apoproteins A-I and A-II

High density lipoproteins (HDL) were recently demonstrated in an enterocyte model (CaCo-2 cells) to mediate reverse cholesterol transport by retroendocytosis. The present study was carried out to define the role of the major HDL apoproteins (apo) A-I and apo A-II in this pathway. HDL3 was fractionated by heparin affinity chromatography into the two main fractions containing either apo A-I only (fraction A) or both apo A-I and apo A-II (fraction B). In addition, liposomes were reconstituted from purified apo A-I or apo A-II and dimyristoyl phosphatidylcholine. The cell binding properties and cholesterol efflux potential were studied in the lipoprotein fractions and the liposomes. Both fractions exhibited similar maximal binding capacities of 4427 (A) and 5041 (B) ng/mg cell protein, but their dissociation constants differed (40.5 and 167.7 micrograms/mL, respectively). Fraction A induced cholesterol efflux and stimulated cholesterol synthesis more than did fraction B. Fraction A mobilized both cellular free and esterified cholesterol, whereas fraction B preferentially mobilized cholesteryl esters. Liposomes, containing either apo A-I or apo A-II, showed specific binding, endocytosis and endosomal transport, and were released as intact particles. Apo A-I liposomes also mediated cholesterol efflux. In conclusion, there is evidence that the HDL3 subfractions A and B, as well as reconstituted liposomes containing either apo A-I or apo A-II, were specifically bound and entered a retroendocytosis pathway which was directly linked to cholesterol efflux. Quantitatively, the apo A-I subfraction appeared to play the dominant role in normal enterocytes. The apo A-II content of fraction B was related to the mobilization of cholesteryl esters.

Pelvic floor activity patterns: comparison of nulliparous continent and parous urinary stress incontinent women. A kinesiological EMG study

OBJECTIVE

To introduce neurophysiological methods to search for damage to neuromuscular structures involved in sustaining continence in women who experienced stress urinary incontinence during pregnancy and/or after delivery.

PATIENTS AND METHODS

Eight stress urinary incontinent parous women (mean of 2.75 vaginal deliveries [range 2-4] median age 45.3 years [range 31-60]) were examined using simultaneous electromyogram recordings of the left and right pubococcygeus muscle via wire electrodes. Comparisons were made with 10 nulliparous continent women (median age 27.2 years [range 22-32]).

RESULTS

Individual muscle activation patterns in stress urinary incontinent parous women were in principle similar to those observed in the continent nulliparous women, with two significant exceptions: (i) voluntary 'squeeze' showed significant differences in the holding time between the parous stress urinary incontinent patients and the nulliparous continent controls, with an empty bladder (49.0 s versus 193.9 s median value) and a full bladder (39.2 s versus 198.4 s); (ii) asymmetrical and uncoordinated levator activation patterns were demonstrated in four of eight parous stress incontinent women, i.e. inhibition of motor unit firing on coughing (n = 3) and dissociated recruitment of motor units during voluntary and reflex activation (n = 1).

CONCLUSION

Childbirth appeared to induce both quantitative and qualitative changes in the pelvic floor which jeopardized the continence mechanism. Sphincter weakness appeared to result not only from the loss of motor units but also from altered activation patterns in the remaining units: shorter activation periods, lack of response or paradoxical inhibition. Kinesiological EMG recordings revealed behavioural abnormalities which appeared relevant for planning treatment.

Activity patterns of pubococcygeal muscles in nulliparous continent women

Simultaneous electromyographic (EMG) recordings from the left and right pubococcygeal muscles were obtained in 10 continent nulliparous women (aged 22-32 years) via wire electrodes inserted percutaneously. During relaxation, sustained motor unit firing was obtained in 14 and no EMG activity in 4 of the 20 recorded muscle sites. During voluntary squeeze, stopping urine in midstream and coughing there was always bilateral recruitment of motor units that was gradual in the recording sites with ongoing EMG activity and brisk in the sites without EMG activity; the 2 different patterns of activity were called "tonic" and "phasic" respectively. Voluntary squeeze led to activation of motor units sustained for 26 to 647 s (median 193.9) with the bladder empty and 25 to 600 s (median 198.4) with a full bladder. A marked decrease in ongoing tonic motor unit activity was seen during the attempt to urinate. Bladder filling caused an increase in tonic activity in 7 females bilaterally and in 1 unilaterally, whereas there was no change in 3 women. During the Valsalva manoeuvre, simultaneous motor unit recruitment was seen in all subjects bilaterally with the bladder empty and in all but one with the bladder full: in the latter case the motor unit recruitment with an empty bladder changed into simultaneous bilateral inhibition of firing of motor units with a full bladder (both in the supine and erect position); this pattern changed to bilateral recruitment of motor units again after bladder emptying. It is important to be familiar with the normal patterns of activity of the pubococcygeal muscles in continent nulliparous women since the denervation injury caused by childbirth might not only weaken these muscles but also influence their behaviour.

[Complications in the kidney pelvis and the ureter following kidney transplantation]

Development of complications of the pelvis and the ureter, especially obstruction and necrosis with an urinary fistula was seen in 35 of 751 patients after kidney transplantation (4.6%). In this study they occurred significantly often in patients with multiple renal arteries of the donor kidney, for example pole arteries. An arterial angiography of the aorta abdominalis in living donors before transplantation is not be neglected. The diagnosis of urological complications includes sonography, in cases of ureteral obstruction percutaneous antegrade urography, and in a given case computed tomography.

Incidence and cause of postpartum urinary stress incontinence

Urinary leakage was reported in 53.5% of our patients at least once during pregnancy. Multigravidae and women older than 30 were affected more often than primigravidae or women younger than 30. 6.2% of all women, who were continent before pregnancy, developed permanent stress incontinence after vaginal delivery. As a conclusion, it can be said, that vaginal delivery itself predisposes for permanent stress urinary incontinence (SUI). Factors, which increase the trauma to the pelvic floor (tear, no episiotomy, forceps or vacuum extraction), show a higher incidence of postpartum persisting SUI without statistic significance. Labour management with epidural anaesthesia showed a statistically proven lower incidence of postpartum persisting SUI in comparison to the pudendal block.

[Malignant tumors of the normotopic kidneys and ureters following kidney transplantation]

There is an 4.2-23% incidence of cancer in renal transplant recipients. A closely meshed radiological follow-up is important as shown in 3 patients who developed a carcinoma of the kidney or ureter within 1-5 years after renal transplantation. This includes routine sonography of the whole abdomen, in case of pathological findings CT respectively MRI, i.v. urography, retrograde urography and angiography if needed.

[DSA in the postoperative diagnosis of patients with kidney transplants]

Image quality and diagnostic significance of intravenous and intraarterial DSA following renal transplantation were assessed in 40 angiographic studies. In 27 of 40 DSA (67.5%) there were pathologic findings such as a renal artery stenosis, aneurysms or rejection within this selected group of patients. There were significant differences in image quality between intravenous and intraarterial DSA. The value of intravenous DSA is limited, particularly in patients with complex anastomosis, implanted polar arteries and kinking stenosis.

[Duplex sonographic findings following kidney transplantation-- possible value in the diagnosis of graft rejection]

59 prospective duplex ultrasound studies have been performed on 30 patients after renal transplant to assess the feasibility of detection of acute rejection. The results were compared with clinical, biochemical and histopathologic findings. Real time ultrasound was not a reliable method in predicting acute rejection. Doppler sonography, however, characteristically showed a diminished diastolic blood flow in all cases of acute rejection. Acute tubular necrosis and cyclosporine toxicity were not provable, neither by real time ultrasound nor by doppler sonography. Duplex ultrasound combines the advantages of both methods in detecting perirenal fluid collections, hydronephrosis and acute transplant rejection.

Graft survival and long-term renal function after sequential conventional cyclosporin A therapy in cadaver kidney transplantation--a prospective randomized trial

In a prospective randomized trial 50 renal transplant patients (group A) received a sequential course of 14 days conventional immunosuppression (Lymphocytoglobulin (ALG), azathioprine, steroids) and cyclosporin and steroids thereafter, while 50 patients (group B) received the conventional immunosuppression for 7 days followed by cyclosporin and steroids. In the latter group ALG was tolerated for the whole period while in the first group conversion from conventional to cyclosporin A therapy had to be performed after a mean of 11 days, due to ALG intolerance. Actual patient survival rates 1 year posttransplant were 100% in both groups and graft survival rates 96% in group A and 86% in group B (P less than 0.05). There was a mean dialysis frequency per patient of 0.7 +/- 2.0 in group A and 1.8 +/- 3.4 in group B (P = 0.064). Serum creatinine 1 year posttransplant was 1.8 +/- 0.8 mg/dl in group A and 2.2 +/- 1.4 in group B. A total of 58 patients had a serum creatinine of less than 2 mg/dl at the time of conversion to cyclosporin. These patients had a significantly better graft survival rate (98.3%) and serum creatinine 1 year posttransplant (1.6 +/- 0.5 mg/dl) than the 40 patients with a serum creatinine of more than 2 mg/dl at the time of conversion (85%; 2.4 +/- 1.4 mg/dl), indicating that a delayed onset of cyclosporin therapy might benefit the kidney in the immediate posttransplant period when it is susceptible to nephrotoxicity due to the damage from hypothermic storage.

[Dilatation of the upper urinary tract in pregnancy--incidence, severity and follow-up. A sonographic study]

Incidence, onset and degree of the dilatation of upper urinary tract as well as the course throughout pregnancy was sonographically assessed in 310 pregnant women without symptoms from the urinary tract. 30 patients were regularly observed from the 16th week of gestation until delivery and within one week post partum. A grading system based on maximum calyceal diameter was used. 25% showed dilated calyces, primiparae more often than multiparae. The right kidney was dilated in 56, the left in 3 and both kidneys in 20 women. No decrease in parenchymal diameter was found during longer lasting dilatation of the pelvicalyceal system. Within one week after delivery the dilatation disappeared in nearly all cases. A gradual linear increase in incidence and severity of dilatation throughout pregnancy was found.

[Artefacts in the recording of stress profiles and their clinical significance]

Using a special technique 35 women presented an artefact in the SUPP caused by urethral movement during coughing. A second artefact was found in patients presenting with extensive vaginal prolapse. The clinical evaluation of the SUPP depends on the exclusion of those artefacts.

[Unstable stress profile--artefact or physiologic phenomenon?]

In 31 women with stable urethral closure pressure at rest the stress urinary profile (SUP) was found to be unstable. The reason was dislocation of the urethra during stress by between 1 mm and 8 mm. Of 14 women with stable SUPs, ten showed no dislocation whereas four had dislocation not exceeding 2 mm. A retrospective analysis revealed that dislocation had occurred in 40 of 114 patients (35.1%). SUPs with signs of dislocation should therefore be interpreted with care.