Association of obesity and muscle mass with risk of albuminuria in renal transplant recipients

BACKGROUND

Increased albuminuria is a predictor of graft loss in kidney graft recipients. It is unknown whether obesity is an independent risk factor for the development of increased albuminuria in this population. The aim of this study was to elucidate the association between obesity and albuminuria in renal transplant recipients.

METHODS

We enrolled 330 renal transplant recipients and prospectively collected demographic, anthropomorphic, clinical and laboratory variables susceptible to influence albumin excretion. The outcome was albuminuria, measured using accurately timed urine collections. Data from 201 patients were analyzed after exclusion of participants with missing data and patients enrolled less than 6 months since renal transplantation. Analysis was carried out for an early and a late period, defined according to the 2.4-year median follow-up time.

RESULTS

Body mass index (BMI), waist circumference and urinary creatinine excretion rate were independent predictors of albuminuria in the late post-transplant period, indicating that the predictive value of body mass index for albuminuria is related to both increased abdominal fat mass and increased muscle mass. BMI was an independent predictor of microalbuminuria. Waist circumference and urinary creatinine were independent predictors of microalbuminuria for values above certain cutoffs: 110% of the accepted thresholds defining abdominal obesity and 1500 mg/day, respectively.

CONCLUSIONS

These associations, which have not previously been reported, suggest, but do not prove, that an imbalance between metabolic demand and nephron mass may be responsible for increased albuminuria in the renal transplant population.

25-Hydroxyvitamin D Inhibits Hepatitis C Virus Production in Hepatocellular Carcinoma Cell Line by a Vitamin D Receptor-Independent Mechanism

Previously, we have reported that the active vitamin D metabolite, calcitriol and vitamin D3 (cholecalciferol), both remarkably inhibit hepatitis C virus production. The mechanism by which vitamin D3 exerts its effect is puzzling due to the low levels of calcitriol produced in vitamin D3-treated Huh7.5 cells. In this study, we aimed to explore the mechanism of vitamin D3 anti-hepatitis C virus effect. We show that vitamin D3 activity is not mediated by its metabolic conversion to calcitriol, but may be due to its primary metabolic product 25(OH)D3. This is inferred from the findings that 25(OH)D3 could inhibit hepatitis C virus production in our system, and that adequate concentrations needed to exert this effect are produced in Huh7.5 cells treated with vitamin D3. Using the CRISPR-Cas9 editing technology to knockout the vitamin D receptor, we found that the antiviral activity of vitamin D3 and 25(OH)D3 was not impaired in the vitamin D receptor knockout cells. This result indicates that 25(OH)D3 anti-hepatitis C virus effect is exerted by a vitamin D receptor-independent mode of action. The possibility that vitamin D3 and 25(OH)D3, being 3β-hydroxysteroids, affect hepatitis C virus production by direct inhibition of the Hedgehog pathway in a vitamin D receptor-independent manner was ruled out. Taken together, this study proposes a novel mode of action for the anti-hepatitis C virus activity of vitamin D3 that is mediated by 25(OH)D3 in a vitamin D receptor-independent mechanism.

Estimating chronic hepatitis C prognosis using transient elastography-based liver stiffness: A systematic review and meta-analysis

Chronic hepatitis C (CHC) is a leading cause of hepatic fibrosis and cirrhosis. The level of fibrosis is traditionally established by histology, and prognosis is estimated using fibrosis progression rates (FPRs; annual probability of progressing across histological stages). However, newer noninvasive alternatives are quickly replacing biopsy. One alternative, transient elastography (TE), quantifies fibrosis by measuring liver stiffness (LSM). Given these developments, the purpose of this study was (i) to estimate prognosis in treatment-naïve CHC patients using TE-based liver stiffness progression rates (LSPR) as an alternative to FPRs and (ii) to compare consistency between LSPRs and FPRs. A systematic literature search was performed using multiple databases (January 1990 to February 2016). LSPRs were calculated using either a direct method (given the difference in serial LSMs and time elapsed) or an indirect method given a single LSM and the estimated duration of infection and pooled using random-effects meta-analyses. For validation purposes, FPRs were also estimated. Heterogeneity was explored by random-effects meta-regression. Twenty-seven studies reporting on 39 groups of patients (N = 5874) were identified with 35 groups allowing for indirect and 8 for direct estimation of LSPR. The majority (~58%) of patients were HIV/HCV-coinfected. The estimated time-to-cirrhosis based on TE vs biopsy was 39 and 38 years, respectively. In univariate meta-regressions, male sex and HIV were positively and age at assessment, negatively associated with LSPRs. Noninvasive prognosis of HCV is consistent with FPRs in predicting time-to-cirrhosis, but more longitudinal studies of liver stiffness are needed to obtain refined estimates.

A New Cutoff for Abnormal Proteinuria in Diabetes Mellitus Patients: Relationship to Albuminuria

BACKGROUND

Proteinuria and albuminuria are markers of kidney injury and function, serving as a screening test as well as a means of assessing the degree of kidney injury and risk for cardiovascular disease and death in both the diabetic and the non-diabetic general population.

OBJECTIVES

To evaluate the association between proteinuria below 300 mg/24 hours and albuminuria, as well as a possible association with kidney function in patients with diabetes mellitus (DM).

METHODS

The medical files of patients with type 1 and type 2 DM with proteinuria below 300 mg/24 hours at three different visits to the Diabetic Nephropathy Clinic were screened. This involved 245 patient files and 723 visits. The data collected included demographics; protein, albumin and creatinine levels in urine collections; blood biochemistry; and clinical and treatment data.

RESULTS

The association between proteinuria and albuminuria is non-linear. However, proteinuria in the range of 162-300 mg/24 hours was found to be linearly and significantly correlated to albuminuria (P < 0.001, r = 0.58). Proteinuria cutoff, based on albuminuria cutoff of 30 mg/24 hours, was found to be 160.5 mg/24 hr. Body mass index (BMI) was the sole independent predictor of proteinuria above 160.5 mg/24 hr. Changes in albuminuria, but not proteinuria, were associated with changes in creatinine clearance.

CONCLUSIONS

A new cutoff value of 160.5 mg/hr was set empirically, for the first time, for abnormal proteinuria in diabetic patients. It appears that proteinuria below 300 mg/24 hr is not sufficient as a sole prognostic factor for kidney failure.

Effect of Acetazolamide on Obesity-Induced Glomerular Hyperfiltration: A Randomized Controlled Trial

AIMS

Obesity is an important risk factor for the development of chronic kidney disease. One of the major factors involved in the pathogenesis of obesity-associated kidney disease is glomerular hyperfiltration. Increasing salt-delivery to the macula densa is expected to decrease glomerular filtration rate (GFR) by activating tubuloglomerular feedback. Acetazolamide, a carbonic anhydrase inhibitor which inhibits salt reabsorption in the proximal tubule, increases distal salt delivery. Its effects on obesity-related glomerular hyperfiltration have not previously been studied. The aim of this investigation was to evaluate whether administration of acetazolamide to obese non diabetic subjects reduces glomerular hyperfiltration.

MATERIALS AND METHODS

The study was performed using a randomized double-blind crossover design. Obese non-diabetic men with glomerular hyperfiltration were randomized to receive intravenously either acetazolamide or furosemide at equipotent doses. Twelve subjects received the allocated medications. Two weeks later, the same subjects received the drug which they had not received during the first study. Inulin clearance, p-aminohippuric acid clearance and fractional lithium excretion were measured before and after medications administration. The primary end point was a decrease in GFR, measured as inulin clearance.

RESULTS

GFR decreased by 21% following acetazolamide and did not decrease following furosemide. Renal vascular resistance increased by 12% following acetazolamide, while it remained unchanged following furosemide administration. Natriuresis increased similarly following acetazolamide and furosemide administration. Sodium balance was similar in both groups.

CONCLUSIONS

Intravenous acetazolamide decreased GFR in obese non-diabetic men with glomerular hyperfiltration. Furosemide, administered at equipotent dose, did not affect GFR, suggesting that acetazolamide reduced glomerular hyperfiltration by activating tubuloglomerular feedback.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01146288.

GFR in Patients with β-Thalassemia Major

BACKGROUND AND OBJECTIVES

Patients with β-thalassemia major (TM) may have tubular dysfunction and glomerular dysfunction, primarily hyperfiltration, based on eGFR. Assessment of GFR based on serum creatinine concentration may overestimate GFR in these patients. This study sought to determine GFR by using inulin clearance and compare it with measured creatinine clearance (Ccr) and eGFR.

DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS

Patients followed up in an Israeli thalassemia clinic who had been regularly transfused for years and treated with deferasirox were included in the study. They were studied by inulin clearance, Ccr, the CKD Epidemiology Collaboration and the Modification of Diet in Renal Disease equations for eGFR, and the Cockcroft-Gault estimation for Ccr. Expected creatinine excretion rate and tubular creatinine secretion rate were calculated.

RESULTS

Nine white patients were studied. Results, given as medians, were as follows: serum creatinine was 0.59 mg/dl (below normal limits); GFR was low (76.6 ml/min per 1.73 m(2)) and reached the level of CKD; Ccr was 134.9 ml/min per 1.73 m(2), higher than the GFR because of a tubular creatinine secretion rate of 30.3 ml/min per 1.73 m(2) (this accounted for 40% of the Ccr); and eGFR calculated by the CKD Epidemiology Collaboration and Modification of Diet in Renal Disease equations and Cockcroft-Gault-estimated Ccr were 133, 141, and 168 ml/min per 1.73 m(2), respectively. These latter values were significantly higher than the GFR, reaching the hyperfiltration range, and indicated that the estimation techniques were clinically unacceptable as a method for measuring kidney function compared with the GFR according to Bland and Altman analyses.

CONCLUSIONS

Contrary to previous reports, patients in this study with TM had normal or reduced GFR. The estimating methods showed erroneous overestimation of GFR and were clinically unacceptable for GFR measurements in patients with TM by Bland and Altman analysis. Therefore, more accurate methods should be used for early detection of reduced GFR and prevention of its further decline toward CKD in these patients.

Vitamin D: an innate antiviral agent suppressing hepatitis C virus in human hepatocytes

Vitamin D supplementation was reported to improve the probability of achieving a sustained virological response when combined with antiviral treatment against hepatitis C virus (HCV). Our aim was to determine the in vitro potential of vitamin D to inhibit HCV infectious virus production and explore the mechanism(s) of inhibition. Here we show that vitamin D(3) remarkably inhibits HCV production in Huh7.5 hepatoma cells. These cells express CYP27B1, the gene encoding for the enzyme responsible for the synthesis of the vitamin D hormonally active metabolite, calcitriol. Treatment with vitamin D(3) resulted in calcitriol production and induction of calcitriol target gene CYP24A1, indicating that these cells contain the full machinery for vitamin D metabolism and activity. Notably, treatment with calcitriol resulted in HCV inhibition. Collectively, these findings suggest that vitamin D(3) has an antiviral activity which is mediated by its active metabolite. This antiviral activity involves the induction of the interferon signaling pathway, resulting in expression of interferon-β and the interferon-stimulated gene, MxA. Intriguingly, HCV infection increased calcitriol production by inhibiting CYP24A1 induction, the enzyme responsible for the first step in calcitriol catabolism. Importantly, the combination of vitamin D(3) or calcitriol and interferon-α synergistically inhibited viral production.

CONCLUSION

This study demonstrates for the first time a direct antiviral effect of vitamin D in an in vitro infectious virus production system. It proposes an interplay between the hepatic vitamin D endocrine system and HCV, suggesting that vitamin D has a role as a natural antiviral mediator. Importantly, our study implies that vitamin D might have an interferon-sparing effect, thus improving antiviral treatment of HCV-infected patients.

The urine albumin-to-creatinine ratio: assessment of its performance in the renal transplant recipient population

BACKGROUND AND OBJECTIVES

Microalbuminuria predicts graft loss and death in the renal transplant population. Measurement of the urinary albumin-to-creatinine ratio (UACR) is recommended for its detection. There is uncertainty regarding the optimal UACR cutoff values. Few studies have examined the accuracy of UACR in the general population and none have been conducted in renal transplant recipients. The aim of this study is to determine the performance of UACR in the renal transplant population.

DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS

Renal transplant recipients with a daily urinary albumin excretion rate of up to 300 mg accurately carried out a 24-hour urine collection and provided a morning urine sample for the measurement of albuminuria and UACR. The performance measures of UACR for the detection of microalbuminuria (30 to 300 mg/d) were calculated using different cutoffs.

RESULTS

Median albuminuria was 23 mg/d, and median UACR was 17 mg/g. The area under the receiver-operating characteristic curve was 0.94 in men and 0.98 in women. The optimal cutoff was 21 mg/g in men and 24 mg/g in women. In men, the 30-, 17-, and 21-mg/g cutoffs provided a sensitivity of 0.79, 0.89, and 0.87. In women, the 30-, 25-, and 24-mg/g cutoffs provided a sensitivity of 0.90, 0.97, and 1.0.

CONCLUSIONS

These data show that in the renal transplant population, lower gender-specific cutoffs should be used for the detection of microalbuminuria than the recommended 30-mg/g cutoff. These data support the need for a reappraisal of the 30-mg/g cutoff for the detection of microalbuminuria.

Obesity-induced glomerular hyperfiltration: its involvement in the pathogenesis of tubular sodium reabsorption

BACKGROUND

Obesity is associated with hypertension and glomerular hyperfiltration. A major mechanism responsible for the obesity-associated hypertension is renal salt retention. An increased glomerular filtration fraction (FF) is expected to raise postglomerular oncotic pressure and to increase proximal tubular sodium reabsorption. The aim of the present study was to verify whether obesity-associated hyperfiltration leads to increased postglomerular oncotic pressure and increased proximal sodium reabsorption.

METHODS

Twelve obese subjects (BMI >36) and 19 lean subjects participated in the study. They underwent measurement of glomerular filtration rate (GFR), renal plasma flow (RPF) and fractional excretion of lithium (FE Li).

RESULTS

GFR, RPF and FF were 61%, 28% and 29% higher, respectively, in the obese than in the control group (P < 0.00001 for GFR, P < 0.005 for RPF and P < 0.00005 for FF). Half of the obese group had increased FF with increased GFR, while the other half had normal FF with high-normal or increased GFR. Postglomerular oncotic pressure was 13% higher (P < 0.03) and FE Li was 33% lower (P < 0.005) in the obese group with high FF than in the lean group. Postglomerular oncotic pressure and FE Li were normal in the obese group with normal FF.

CONCLUSIONS

These results suggest that glomerular hyperfiltration may lead to increased proximal tubular sodium reabsorption in the obese.

Superficial cell differentiation during embryonic and postnatal development of mouse urothelium

After drastic urothelial destruction around birth and around postnatal day 6, mouse urothelial renewal starts each time de novo. The differentiation of superficial cells during urothelial restoration was followed for the first time from embryonic day 15 to postnatal day 6 by the detection of differentiation markers: cytokeratins, uroplakins and apical membrane specialization. The differentiation markers of short-lived superficial cells were studied before and after urothelial destruction. Three distinctive types of superficial cells, typical for certain developmental period, were characterised: cells at low differentiation stage with microvilli and cilia, expressing CK7 and CK18, detected on embryonic day 15; cells at advanced differentiation stage with star-like arrangement of prominent membrane ridges, expressing CK7 and CK20, present between the two urothelial destruction events; highly differentiated cells with typically jagged apical surface, expressing CK7 and CK20, found twice during development. This cell type appears for the first time on embryonic day 18 as the terminal stage of embryonic differentiation. It was found again on postnatal day 6 as an initial stage of differentiation, leading toward terminally differentiated cells of the adult urothelium. Our work proves that apical membrane specialization is the most valuable differentiation marker of superficial cells.

Renin-angiotensin system blockade prevents the increase in plasma transforming growth factor beta 1, and reduces proteinuria and kidney hypertrophy in the streptozotocin-diabetic rat

INTRODUCTION

Combination therapy with angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) is used to improve renal outcome achieved by monotherapy in diabetic patients. In addition, interference with the renin-angiotensin system (RAS) reduced expression and excretion of transforming growth factor beta 1 (TGF-beta 1) in diabetic nephropathy. The aim of this study was to investigate the effects of interrupting the RAS by ACE inhibitor (ACE-I) or ARB monotherapy or by combination therapy on proteinuria, kidney hypertrophy and plasma TGF-beta 1 in diabetic rats.

MATERIALS AND METHODS

Forty-one male Wistar rats were allocated to five groups: 1 = control rats, 2 = diabetic rats (streptozotocin [STZ] 55 mg/kg), 3 = diabetic rats as above receiving enalapril (20 mg/kg/day), 4 = diabetic rats receiving losartan (80 mg/kg/day), 5 = diabetic rats receiving both losartan and enalapril. The study lasted 60 days.

RESULTS

Urinary protein excretion, kidney weight, serum ACE activity and plasma TGF-beta1 increased significantly in untreated diabetic rats compared with controls. Administration of losartan, enalapril, or both for 60 days prevented these changes. Furthermore, combined therapy for 30 days normalised urinary protein excretion, while monotherapy did not. Losartan inhibited serum ACE activity both in vivo and in vitro. Plasma TGF-beta 1 levels were positively correlated with blood glucose levels (r=0.4059) and with urinary protein excretion (r=0.3558).

CONCLUSIONS

Combination therapy with losartan and enalapril was more effective than monotherapy with either drug in achieving an early antiproteinuric response. Long-term treatment with losartan was as effective as the combined treatment, possibly due to a dual inhibitory effect on the RAS. The antiproteinuric effect may be related, in part, to reduced TGF-beta 1.

Coenzyme Q10 in patients with end-stage heart failure awaiting cardiac transplantation: a randomized, placebo-controlled study

BACKGROUND

The number of patients awaiting heart transplantation is increasing in proportion to the waiting period for a donor. Studies have shown that coenzyme Q10 (CoQ10) has a beneficial effect on patients with heart failure.

HYPOTHESIS

The purpose of the present double-blind, placebo-controlled, randomized study was to assess the effect of CoQ10 on patients with end-stage heart failure and to determine if CoQ10 can improve the pharmacological bridge to heart transplantation.

METHODS

A prospective double-blind design was used. Thirty-two patients with end-stage heart failure awaiting heart transplantation were randomly allocated to receive either 60 mg U/day of Ultrasome--CoQ10 (special preparation to increase intestinal absorption) or placebo for 3 months. All patients continued their regular medication regimen. Assessments included anamnesis with an extended questionnaire based partially on the Minnesota Living with Heart Failure Questionnaire, 6-min walk test, blood tests for atrial natriuretic factor (ANF) and tumor necrosis factor (TNF), and echocardiography.

RESULTS

Twenty-seven patients completed the study. The study group showed significant improvement in the 6-min walk test and a decrease in dyspnea, New York Heart Association (NYHA) classification, nocturia, and fatigue. No significant changes were noted after 3 months of treatment in echocardiography parameters (dimensions and contractility of cardiac chambers) or ANF and TNF blood levels.

CONCLUSIONS

The administration of CoQ10 to heart transplant candidates led to a significant improvement in functional status, clinical symptoms, and quality of life. However, there were no objective changes in echo measurements or ANF and TNF blood levels. Coenzyme Q10 may serve as an optional addition to the pharmacologic armamentarium of patients with end-stage heart failure. The apparent discrepancy between significant clinical improvement and unchanged cardiac status requires further investigation.

[Recurrent meningiomas with progressive aggressiveness and posterior extracranial extension]

Meningiomas are in most cases benign tumors. They represent about 15% of primitive intracranial tumors. Complete surgical resection achieves healing in the majority of patients. Recurrences occur in 9 to 12% in spite of that kind of surgical resection in the initial approach. This percentage rises to 40% when removing was not complete. Recurrences sometimes show histological changes into aggressiveness, and even malignization. Two cases of originally benign meningiomas with several recurrences and progressive aggressive behaviour are presented. Both cases led to extracranial extension of the lesions, even passing through synthetic dural grafts (De Bakey's Dacron Fabric-Elastic) and the Titanium mesh covering the craniectomy.

Insulin and losartan reduce proteinuria and renal hypertrophy in the pregnant diabetic rat

This study was designed to investigate the effect of hyperglycemia and angiotensin II (AngII) on renal hypertrophy and proteinuria in the pregnant diabetic rat. Secondary objectives were to evaluate changes in components of the renin-angiotensin axis and the effects of administration of losartan on pregnancy outcome. Fifty-three pregnant rats were allocated to 6 groups (1) nondiabetic controls (n = 12), (2) nondiabetic controls administered losartan (70-80 mg/kg/day; n = 10), (3) rats in which intravenous streptozotocin (STZ) was used to induce diabetes (55 mg/kg on day 10 of pregnancy; n = 10), (4) diabetic rats treated with losartan (n = 7), (5) diabetic rats treated with insulin (4 U/day; n = 7), and (6) diabetic rats treated with insulin and losartan (n = 7). Urinary protein excretion measured 4 days after STZ was 4 times greater in the rats with STZ-induced diabetes and significantly less in diabetic rats given losartan, insulin, or both. Postpartum kidney weight was greater in the rats with STZ-induced diabetes (2.04 +/- 0.21 g) than in the controls (1.37 +/- 0.14 g; P <.05) and reduced in the diabetic rats given losartan, insulin, or both (1.57 +/- 0.22, 1.73 +/- 0.13, and 1.51 +/- 0.14 g, respectively; P <.05). Plasma levels of angiotensin II in rats given losartan were more than 3.5 times greater than those in controls (749 +/- 436, 596 +/- 323, 567 +/- 349, and 159 +/- 28 pg/mL; P <.001). Postpartum activity of angiotensin-converting enzyme was increased in the untreated diabetic rats compared with that in control rats (162 +/- 12 vs 117 +/- 16 nmol/mL/min; P <.05). This increase was abolished by treatment with losartan or insulin. The number of newborns and mean weight of each newborn was similar in all groups. In summary, administration of losartan or insulin prevented, in part, kidney hypertrophy and protein excretion in the diabetic pregnant rat. Losartan did not affect the number or weight of newborns. Because angiotensin II receptor-blockers are contraindicated in pregnancy, good control of diabetes through the use of insulin should be advantageous.

Beta2-microglobulin and hypertensive complications in pregnant women at risk

BACKGROUND AND AIM

Beta2-microglobulin (beta2-m) is a polypeptide, which is freely filtered through the glomerular basement membrane and absorbed almost entirely by the proximal tubular cells. Preeclampsia, a common complication of pregnancy, is characterized by pathological renal changes, mainly glomerular lesions. The aim of the present study was to investigate whether serum beta2-m measured in the early stages of pregnancy could be used as a marker to predict hypertensive complications in women at increased risk.

PATIENTS AND METHODS

Serum beta2-m concentrations were prospectively measured in 75 pregnant women with history of chronic hypertension, chronic renal disease, chronic vascular disease or preeclampsia and compared with those in 16 healthy pregnant women.

RESULTS

Of the 75 women in the study group, 10 (13%) developed preeclampsia and 20 (26%) had other complications, such as intrauterine growth restriction (n = 8), fetal or neonatal loss (n = 9) and delivery before 30 weeks of gestation (n = 8). Gestational age at delivery, birth weight and cesarean section rate were significantly worse in the patients with complications than in those without and in the healthy controls. No significant difference was detected in early serum beta2-m concentrations between the women who later developed preeclampsia or other complications and those who did not. There was a significant positive correlation of beta2-m concentrations with serum creatinine level (R2 = 0.394, p < 0.001), but not with gestational week at blood collection.

CONCLUSION

Serum beta2-m concentrations are not predictive of the development of preeclampsia or other complications in woman at risk.

Involvement of human heparanase in the pathogenesis of diabetic nephropathy

BACKGROUND

Decreased heparan sulfate proteoglycan content of the glomerular basement membrane has been described in proteinuric patients with diabetic nephropathy. Heparanase is an endo-beta-D-glucuronidase that cleaves negatively charged heparan sulfate side chains in the basement membrane and extracellular matrix.

OBJECTIVES

To investigate whether urine from type I diabetic patients differs in heparanase activity from control subjects and whether resident glomerular cells could be the source of urinary heparanase.

METHODS

Using soluble 35S-HSPG and sulfate-labeled extracellular matrix we assessed heparanase activity in human glomerular epithelial cells, rat mesangial cells, and urine from 73 type I diabetic patients. Heparanase activity resulted in the conversion of a high molecular weight sulfate-labeled HSPG into heparan sulfate degradation fragments as determined by gel filtration analysis.

RESULTS

High heparanase activity was found in lysates of both epithelial and mesangial cells. Immunohistochemical staining localized the heparanase protein to both glomeruli capillaries and tubular epithelium. Heparanase activity was detected in the urine of 16% and 25% of the normoalbuminuric and microalbuminuric diabetic patients, respectively. Urine from 40 healthy individuals did not possess detectable heparanase. Urinary heparanase activity was associated with worse glycemic control.

CONCLUSION

We suggest that heparanase enzyme participates in the tunover of glomerular HSPG. Hyperglycemia enhances heparanase activity and/or secretion in some diabetic patients, resulting in the loss of albumin permselective properties of the GBM.

The contribution of an arteriovenous access for hemodialysis to left ventricular hypertrophy

BACKGROUND

The long-term isolated contribution of hemodialysis arteriovenous access (AVA) to cardiac hemodynamics has not been previously investigated in a prospective manner.

METHODS

Twelve predialysis patients were studied before and 1 and 3 months after creation of a primary AVA. Evaluation included relevant clinical parameters, echocardiographic studies, and hemodynamic hormones.

RESULTS

After creation of an AVA, there was no change in patient weight, blood pressure or hemoglobin level. Cardiac index increased and systemic vascular resistance decreased. Left ventricular mass (LVM) corrected to height increased from 63.8 +/- 5.5 to 68.9 +/- 4.9 g/m(2.7) at 1 month (P = 0.05) and 72.5 +/- 8.9 g/m(2.7) at 3 months (P < 0.05). This increase in LVM was accounted for mostly by an increase in interventricular septal thickness, whereas left ventricular end-diastolic diameter and posterior wall thickness did not change. The incidence of left ventricular hypertrophy (LVH) increased from 67% at baseline to 83% and 90% at 1 and 3 months, respectively. Left atrial area increased from 17.6 +/- 1.0 cm(2) at baseline to 19.7 +/- 1.3 cm(2) at 1 month (P < 0.01) and 20.2 +/- 1.2 cm(2) at 3 months (P < 0.05). Early diastolic transmitral flow increased from 68.0 +/- 4.2 cm/s at baseline to 85.6 +/- 7.3 and 89.2 +/- 6.5 cm/s at 1 and 3 months, respectively (P < 0.01). Inferior vena cava diameter increased at 1 month and did not change at 3 months. Plasma atrial natriuretic polypeptide levels increased from 268 +/- 35 pg/mL (87 +/- 11 pmol/L) at baseline to 461 +/- 63 pg/mL (150 +/- 20 pmol/L) at 1 month (P < 0.01) and 610 +/- 96 pg/mL (198 +/- 31 pmol/L) at 3 months (P < 0.01). Plasma renin activity and serum aldosterone levels decreased. Plasma angiotensin II, angiotensin-converting enzyme, and endothelin levels did not change.

CONCLUSION

Creation of a hemodialysis AVA is independently associated with further progression of already existing LVH.

[Names-Lab : a model for the standardization of biology message exchanges]

The growing requirements of communication between health partners urges to standardize the language used in laboratories data management systems. Names-Lab is the only semantic reference system allowing to describe synchronously the body of prescription and result messages. Its hierarchical structure allows a simple coding, easily accessible to all biologists without imposing or even requiring a language. Other internationally proposed systems as Loinc and Euclides are similar to Names-Lab in their purposes but are completely different by their content and structure. This prompts the medical and biologic community for a comparison of these tools before setting the choice of an international referencing system.

Increased serum angiotensin-converting enzyme activity and plasma angiotensin II levels during pregnancy and postpartum in the diabetic rat

OBJECTIVE

The renin-angiotensin system (RAS) plays an important role in the regulation of blood pressure, electrolyte balance and renal function in normal human pregnancy. The present study was designed to assess various components of the RAS and renal function during pregnancy and immediately after pregnancy in the streptozotocin (STZ)-diabetic rat.

METHODS

Pregnant Wistar rats were allocated to three groups: I-control, non-diabetic rats (n=24), II-STZ-diabetic rats (STZ 55 mg/kg body weight, i.v. on day 10 of pregnancy, n=24), III-diabetic rats, as above, treated with insulin (4 units/day, s.c. n=21). On days 17-18 of pregnancy, or within 24 hours after delivery, the rats were sacrificed and the various components of the RAS were determined.

RESULTS

Urinary protein excretion (UP) and creatinine clearance(CCr) were greater in group II, four days after STZ, than in group I (UP: I-7.6+/-2.8, II-18.6+/-6.3 mg/24-hour, p<0.001, CCr: I-1.04+/-0.33, II-2.38+/-0.7 ml/minute, p<0.001). Mean (+/-SD) serum angiotensin-converting enzyme (ACE) activity and plasma angiotensin II(Ang II) levels at days 17-18 of pregnancy were greater in the untreated diabetic rats than in control pregnant rats (ACE: 163+/-18 vs. 111+/-21 nmol/ml/minute, p<0.001, Ang II: 115+/-45 vs. 43+/-10 pg/ml, p<0.005). Postpartum serum ACE activity and plasma Ang II levels were greater in group II (ACE: I-123+/-14, II-142+/-24, III-108+/-21 nmol/ml/minute, p<0.01, Ang II: I-56+/-38, II-148+/-62, III-38+/-17 pg/mI, p<0.001). ACE activity in the lung was greater, whereas the activity in the renal cortex was less, in group II than in group I. Kidney weight in untreated diabetic rats was greater than in the other two groups.

CONCLUSION

Increased serum ACE activity during pregnancy and postpartum in the untreated diabetic rat is associated with enhanced serum Ang II levels, which may contribute to increased protein excretion and renal hypertrophy.

Postnatal restoration of the mouse urinary bladder urothelium

Mouse urothelium is disrupted just before birth, followed by a postnatal restoration process which includes cell proliferation, death and differentiation. We assessed urothelial proliferation by the expression of proliferating cell nuclear antigen (PCNA), desquamation by electron microscopy, and apoptosis by TUNEL staining and urothelial differentiation by the expression of uroplakins and cytokeratin 20 (CK20) as well as the apical plasma membrane maturation. Our results indicated that urothelial proliferation was high from birth until about the 14th postnatal day. A majority of basal cells and even occasional superficial cells were PCNA positive during the first 5 postnatal days. Cell death occurred during the first 9 postnatal days. Between birth and day 5, single cells underwent apoptosis, whereas between days 6 and 9 cells mainly desquamated. CK20 and uroplakins were expressed in all superficial cells in postnatal urothelium. Their subcellular distribution characteristically changed in accordance with the progressive differentiation of superficial cells. During the urothelial postnatal development, proliferation activity slowly decreases to the proliferatively quiescent urothelium of the adult animal. Apoptosis is present in the first 9 postnatal days and within a few days of this period it appears simultaneously with desquamation. Superficial urothelial cells gradually differentiate, which is reflected in the changeable morphology of the apical plasma membrane.

Mouse urothelial cells in early postnatal development--proliferation and apical plasma membrane specialization

The purpose of this work was to investigate proliferation and differentiation of the mouse urothelial cells from the day of birth until the 5th postnatal day. The expression of proliferating cell nuclear antigen (PCNA) was studied immunocytochemically and the differentiation of apical plasma membrane of superficial cells was analysed by scanning microscopy. It was established that proliferation activity is very high during all five days since PCNA positive cells are seen in the superficial and in basal cell layer of the urothelium. Results of scanning microscopy show that the differentiation of superficial urothelial cells is a nonsynchronous process, which gradually progresses from the day of birth and leads into homogeneous population of terminally differentiated superficial cells on the 5th postnatal day.

Effects of vasoactive substances released from ischemic reperfused liver on the isolated rat heart

BACKGROUND

Cardiovascular dysfunction frequently occurs after major vascular surgery or liver transplantation.

OBJECTIVE

To evaluate the effects on myocardial activity of vasoactive agents released from ischemic-reperfused liver.

ANIMALS AND METHODS

Isolated rat livers were perfused with Krebs-Henseleit solution (KH), propranolol 10(-5) M, losartan 2x10(-5) M and indomethacin 10(-5) M, then made globally ischemic for 120 min (37 degrees C) and reperfused. Isolated hearts from other rats were stabilized with KH and reperfused for 15 min with the perfusate exiting the livers. Livers were disconnected, and the hearts continued to be recirculated with the accumulated liver and heart effluent for an additional 50 min. Enzyme leakage, different vasoactive substances, left ventricular developed pressure (LVP) and coronary flow were measured during the experimental protocol.

RESULTS

Hepatic release of adrenaline, noradrenaline, angiotensin II, prostaglandin E(2) and thromboxane B(2) was significantly increased in the liver effluent following ischemia. When this effluent was directed to the heart, LVP was significantly raised in the first 10 min of reperfusion (137+/-5%) followed by marked decreased (46+/-6%) during the following 65 min of myocardial reperfusion. In the ischemic-reperfused drug-treated groups, the initial positive effect on LVP was milder than in controls (propranolol 112+/-12%, losartan 111+/-11%, indomethacin 113+/-9%) and the final LVP was lower (propranolol 29+/-6%, losartan 27+/-7% [P<0.05 versus ischemic control], indomethacin 46 +/-12%).

CONCLUSION

During the initial phase of reperfusion, vasoactive substances released in the hepatic effluent potentiated LVP of the hearts exposed to this effluent. When the three inhibitory drugs were added to KH, this initial augmentation was not sustained. Propranolol and losartan, but not indomethacin, further depressed LVP. Vasoactive substances released from ischemic reperfused livers directly influenced heart function.

Should the use of short acting angiotensin-converting enzyme inhibitors be abandoned?

BACKGROUND

Angiotensin-converting enzyme inhibitors (ACE-I) have different modes of action and different durations of inhibition. The effects of ACE-I on the various components of the renin-angiotensin system (RAS) at trough hours were studied in patients with diabetes mellitus receiving long-term ACE-I treatment.

METHODS

Out of 86 Type 1 and 2 diabetic patients, 49 were untreated, 25 received captopril and 12 received enalapril as chronic treatment. Blood for the determination of plasma renin activity (PRA), serum ACE activity and plasma angiotensin II (Ang II) was drawn in the morning (0700-0900 hours) after an overnight fast, about 12 hours after the last dose. PRA and Ang II were measured by RIA and serum ACE activity was assayed by a radiometric assay using (3)H-hippuryl-glycyl-glycine as a substrate.

RESULTS

Mean age was significantly greater in the enalapril-treated patients. Systolic and diastolic blood pressures were not different between the captopril-treated and untreated groups. Serum ACE activity in the captopril-treated diabetic patients was 101.5+/-42.5 nmol/mL/min, values obtained in untreated diabetic patients (101.4+/-25.2 nmol/mL/min). In contrast, ACE activity in the enalapril-treated patients was significantly reduced (5.5+/-7.5 nmol/mL/min) compared with untreated and captopril-treated patients (p<0.00001). PRA values in the ACE-I treated patients were significantly increased. Plasma Ang II levels were significantly increased in the captopril-treated vs. untreated patients (65.1+/-50.2 vs. 36.2+/-31.7 pg/mL, p=0.006), whereas the values in the enalapril-treated patient were slightly, but not significantly, reduced (23.8+/-21.4 pg/mL). CONCLUSIONS Trough serum ACE activity is not suppressed in diabetic patients receiving captopril, compared with those receiving enalapril and we thus question the use of short acting ACE-I in these patients.

[Exploration of the uterine cavity in the gynecologic preoperative diagnosis]

BACKGROUND

The diagnostic accuracy of dilatation and curettage (D & C) was studied comparing retrospectively the results of histologic findings of D & C with the correspondent specimen from hysterectomy.

METHODS

During five years, at the Institute of Gynecology and Obstetrics, II University of Studies in Naples, 260 women underwent hysterectomy, 160 of which underwent D & C prior to hysterectomy. The histologic findings were classified in: a) physiological endometrium; b) hyperplasia; c) polyps; d) atrophia; e) adenomatous hyperplasia; f) adenocarcinoma. During the period January 1989-October 1993, 260 patients underwent hysterectomy. The age was between 32 and 65 years. The indications to the intervention were: menometrorrhagia, hypogastric pains, dysmenorrhea, metrorrhagia, genital prolapse, urinary incontinence, anemia. Two hundred-sixty patients underwent hysterectomy, 160 of which underwent D & C prior to hysterectomy. Curettage was performed using a right size curette after dilatation of the uterine cervix using Hegar's metallic dilatator. Patients were submitted to general anesthesia. Histologic tissues were fixed with formalin and were sent to the Institute of Anatomopathology for examinations.

RESULTS

The histologic results obtained by cavitary exploration have been compared with those reached by the analysis of the surgical samples. The results obtained confirm the reliability of D & C for the identification of endometrial lesions.

CONCLUSIONS

Therefore, the diagnostic utility of cavitary exploration before hysterectomy is confirmed, particularly in selected cases.

Microalbuminuria after pregnancy complicated by pre-eclampsia

BACKGROUND

Microalbuminuria is an important risk factor for underlying vascular disease. Its detection after pregnancy complicated by pre-eclampsia may have predictive value for the later development of chronic hypertension or renal disease.

METHOD

The study group consisted of 48 women in whom pregnancy had been complicated by pre-eclampsia. Urinary albumin excretion rate, blood pressure, and renal function parameters were assessed 2-4 months and 3-5 years after the pregnancy. Results were compared with those in 44 women after normal pregnancy.

RESULTS

Mean urinary albumin excretion rate was significantly higher in the study group than in the controls both at 2-4 months after delivery (27.0 +/- 33 vs 6.1 +/- 3.3 mg/24 h) and at 3-5 years after delivery (23.5 +/- 26.8 vs 6.7 +/- 2.8 mg/24 h) (P = 0.001). The rate of occurrence of microalbuminuria was not significantly different between the early (58%) and late (42%) time-points within the study group or between the nulliparous and the multiparous women.

CONCLUSIONS

A history of pregnancy complicated by pre-eclampsia is associated with a high occurrence of microalbuminuria. Whether the presence of microalbuminuria reflects a possible underlying vascular disease in affected patients needs to be further investigated in large-scale studies.

Acute and chronic effects of spirapril, alone or in combination with isradipine on kidney function and blood pressure in patients with reduced kidney function and hypertension

In the present study we investigated the effect of a single dose, and 3 months of treatment with spirapril on kidney function, renin-angiotensin system, renal handling of sodium and blood pressure, in patients with reduced kidney function (serum creatinine 1.5-3 mg%) and hypertension. A single dose of 6 mg spirapril given at the beginning of the study did not affect glomerular filtration rate (GFR), renal plasma flow (RPF), angiotensin converting enzyme (ACE) activity, plasma renin activity (PRA) or renal handling of sodium. When the single dose of spirapril was given after 3 months of treatment with this agent, renal hemodynamics and PRA did not change. ACE activity, which was depressed by the previous spirapril treatment, decreased further (from 9.5 +/- 3.1 to 1.4 +/- 1.0 nmol/ml/min), (p < 0.05). Administration of 6 mg spirapril o.d. for 3 months did not have any effect on GFR or RPF. Serum ACE activity decreased from 92.1 +/- 8.0 to 5.1 +/- 2.6 nmol/ml/min (p < 0.05) and PRA increased from 1.4 +/- 1.2 to 4.1 +/- 3.6 ng/ml/min (p < 0.05). Plasma aldosterone did not change. Similar results were obtained when spirapril was combined with 5 mg isradipine in the initial and final single dose, or in the 3 months' treatment (5 mg o.d.). Blood pressure was normalized in 38% of the patients who received spirapril and in 71% of the patients who received spirapril and isradipine. Thus, (a) treatment with spirapril in patients with mild to moderate chronic renal insufficiency was not associated with deleterious effects on kidney function; (b) spirapril in a dose of 6 mg alone or in combination with 5 mg isradipine is effective in reducing blood pressure in hypertensive patients with reduced kidney function.

DNA polymorphisms in the ACE gene, serum ACE activity and the risk of nephropathy in insulin-dependent diabetes mellitus

BACKGROUND

To determine the relationship between DNA polymorphisms in the angiotensin I converting enzyme (ACE) gene, serum ACE activity and the risk of diabetic nephropathy.

METHODS

A case-control study was carried out in a population of Jewish insulin-dependent diabetes mellitus (IDDM) patients. Cases (77 IDDM patients with diabetic nephropathy) and controls (89 IDDM patients with normoalbuminuria) were genotyped with PCR protocols for detecting two DNA polymorphisms in the ACE gene: one in intron 7 detected with the restriction enzyme PstI and the other in intron 16 identified as an insertion/deletion (I/D).

RESULTS

The risk of nephropathy was increased only in patients homozygous for the allele with the PstI site. These homozygotes had a nephropathy risk that was 2.3 times (95% C.I.: 1.2-4.5) that of the other genotypes. Furthermore, these individuals did not have elevated serum ACE activity.

CONCLUSIONS

The results of this study are evidence that the risk of diabetic nephropathy in IDDM is influenced by genetic variability at the ACE locus, but the responsible variant is not the I/D polymorphism in intron 16. Our findings require further studies in other populations.

Increased production of beta2-microglobulin after heart transplantation

Serum beta2-microglobulin (beta2m) levels were measured to evaluate the state of immunoactivation in stable heart transplant recipients. Serum beta2m and renal function of 29 heart transplant recipients were compared with 16 control subjects, who were age and sex matched, and 11 patients with chronic kidney failure. Serum creatinine and 24-hour urine collection for albuminuria were used as markers of renal impairment. Heart transplant recipients with normal renal function (n = 7) had significantly elevated beta2m levels compared with control subjects: 2.6 +/- 0.9 vs 1.66 +/- 0.32 microg/ml, p < or = 0.05. Heart transplant recipients with impaired renal function (n = 22) had significantly elevated beta2m compared with the chronic kidney failure group: 4.42 +/- 1.3 vs 3.49 +/- 0.66 microg/ml (p < or = 0.05); although there was no significant difference in serum creatinine levels. Albuminuria excretion was significantly elevated in the chronic kidney failure group compared with the heart transplant recipients with impaired renal function (p < or = 0.05). Elevated serum beta2m in heart transplant recipients suggests increased beta2m production, reflecting increased immunoactivation. This observation could be useful in monitoring long-term immunosuppressive therapy.

Insulin treatment reduces the increased serum and lung angiotensin converting enzyme activity in streptozotocin-induced diabetic rats

Serum and lung angiotensin-converting enzyme (ACE) activity is increased in the streptozotocin (STZ)-diabetic rat. In the present study, the effect of insulin treatment on this increased ACE activity in the STZ-diabetic rat was investigated. Serum and tissue ACE activity was determined by radiometric assay using [3H]-Hippuryl-glycyl-glycine as substrate. Fifteen days after onset of diabetes (n = 16), 8 rats received insulin daily (6-12 units/kg, s.c.) for 33 days, 8 diabetes rats remained untreated. Control, non-diabetic, rats (n = 8) received saline. The baseline serum ACE activity in the control group was 595 +/- 13 nmol/ml/min and did not change significantly throughout the study. However, serum ACE activity in the untreated diabetic rats increased significantly as of day 14 post-STZ (650 +/- 24 nmol/ml/min, p < 0.001) compared to the corresponding values of the control group and compared to baseline values. Insulin administration to diabetic rats starting on day 15 post-STZ caused a gradual reduction in serum ACE activity to basal values, being (527 +/- 22 nmol/ml/min) at day 47. ACE activity in lungs of untreated diabetic rats was increased by 46%, 47 days post-STZ. Insulin treatment reduced lung ACE activity to values similar to those observed in non-diabetic rats. These changes were associated with reduced kidney weight and urine volume. In summary, insulin administration to hyperglycaemic rats resulted in a reduction in the enhanced serum and lung ACE activity to values seen in non-diabetic rats. Normalizing the activity of the renin-angiotensin system may slow or prevent the glomerular hypertension, a major factor in the development of diabetic nephropathy.

Thromboxane production in human lung during cardiopulmonary bypass: beneficial effect of aspirin?

BACKGROUND

Increased systemic levels of thromboxane (Tx) during cardiopulmonary bypass (CPB) in humans have been reported. It is not known whether this reflects a general systemic response to the surgical procedure or an increased pulmonary production of Tx in response to ischemia and reperfusion.

METHODS

Thromboxane B2 levels were measured in the right atrium and left atrium of 14 patients undergoing coronary artery bypass grafting for angina. Eight patients (group 1) were without aspirin for at least 15 days before operation, and 6 patients (group 2) were treated with aspirin (100 mg/day) for at least 1 month before operation. Levels of TxB2 were determined by enzyme immunoassay after lipid extraction and separation.

RESULTS

Thromboxane B2 levels were elevated throughout CPB. In group 1, left atrial TxB2 levels were significantly higher (p < 0.05) than right atrial levels at all study points during CPB. After pulmonary reperfusion, TxB2 levels in both atria increased significantly (p < 0.02) compared with the levels before cross-clamping of the aorta, and there was an increasing gradient between the two atria (p < 0.05). Mean plasma TxB2 levels during CPB in group 2 were significantly reduced (p < 0.0001) in the right atrium (by 73%) and in the left atrium (by 69%) compared with levels in group 1.

CONCLUSIONS

The rise in TxB2 levels in the left atrium after CPB in humans reflects production of Tx mainly in the lungs, most probably by ischemic pulmonary tissue and intravascular hematologic components. Aspirin markedly reduces Tx production during CPB, and it might play a major role in preventing pulmonary injury after operations with CPB in humans.

Serum and renal IGF-I levels after uninephrectomy in the rat

The hypertrophy of the remaining kidney following uninephrectomy (UNx) has been related to an increase in renal insulin growth factor-I (IGF-I) content. However, while the increase in renal IGF-I lasts for only days after UNx, renal hypertrophy continues for months. In the present study we investigated whether IGF-I also plays a role in the late post uninephrectomy growth of the remaining kidney. Renal IGF-I in the remnant kidney was greater than that of control kidneys (78.3 +/- 17.3 vs 56.0 +/- 14.0 pmol g-1; p < 0.05) 3 days after UNx, tended to remain higher 30 days after UNx (83.8 +/- 23.6 vs 57.3 +/- 14.5 pmol g-1; p = 0.07), but was similar to that of the control kidney when examined 60 days after UNx (66.6 +/- 15.6 vs. 70.4 +/- 6.7 pmol g-1). Serum IGF-I in uninephrectomized rats was similar to that of controls 3 days after UNx, started to increase above the control level at day 10 after UNx and remained higher 30 and 60 days after UNx (75.9 +/- 6.9 vs. 48.7 +/- 7.3 nmol l-1 at 30 days, and 81.2 +/- 13.7 vs 52.9 +/- 11.0 nmol l-1 at day 60, p < 0.05 for both). The kidney weight of uninephrectomized rats was higher by 21% than that of controls 3 days after UNx, by 45% 30 days after UNx and by 63% 60 days after UNx (p < 0.05 for all three observations). At the end of the study, the glomerular volume of uninephrectomized rats was higher by 36% than that of the controls (p < 0.05) We suggest that in the rat, while the initial post uninephrectomy hypertrophy of the remnant kidney is associated with and most probably mediated by an increase in renal IGF-I, the hypertrophy that persists in later post UNx periods is associated with and may be mediated by an increase in serum IGF-I.

The effect of an angiotensin converting enzyme inhibitor on skin microvascular hyperaemia in microalbuminuric insulin-dependent diabetes mellitus

Patients with longstanding insulin-dependent (Type 1) diabetes mellitus (IDDM) are reported to have microvascular complications in most capillary beds. The microvascular hyperaemia of the skin in normoalbuminuric and microalbuminuric IDDM patients and healthy volunteers was measured with laser Doppler flowmetry. The effect of 3 and 9 months of treatment with captopril, an angiotensin converting enzyme inhibitor, on hyperaemia in the microalbuminuric patients was studied. Mean (+/- SD) pretreatment duration of skin postocclusive reactive hyperaemia was longer in microalbuminuric than in both normoalbuminuric patients and healthy volunteers (118.2 +/- 34.4 vs 57.8 +/- 16.0 vs 63.3 +/- 18.3 sec, respectively, p < 0.00001). After 3 and 9 months of captopril treatment the prolonged hyperaemia was shortened to 78.6 +/- 45.6 s (p < 0.01) and 62.3 +/- 55.6 s (p < 0.03), respectively. Urinary albumin excretion decreased from 63.9 +/- 43.5 to 33.4 +/- 28.1 mg 24 h-1 at 3 months treatment (p < 0.002) and 43.1 +/- 38.5 mg 24 h-1 at the end of the study period (p < 0.02). A positive correlation between changes in urinary albumin excretion and the shortening of the skin postocculsive reactive hyperaemia was found. Blood pressure remained in the same range throughout. These results show that captopril affects skin blood flow, independent of its hypotensive effect. This action may reflect the influence of angiotensin converting enzyme inhibitor on vascular beds other than those of the kidneys.

Microalbuminuria in early pregnancy in normal and high-risk patients

The albumin excretion rate (AER) is elevated in normal pregnant women in the third trimester of pregnancy, compared to the second and first trimesters, and to the non-pregnant state. The effect of early pregnancy on AER values was tested in normal and high-risk pregnant patients using radioimmunoassay. All pregnant patients demonstrated significantly higher AER values as compared to non-pregnant women, and the results were in correlation with higher urinary creatinine clearance values. The appearance of microalbuminuria in the first trimester can indicate underlying renal damage in patients at high risk of hypertensive complications.

Microalbuminuria as an early marker of severity in hypertensive pregnant women

The value of microalbuminuria in predicting hypertensive complications in pregnant patients at high risk was tested in a prospective trial. A total of 276 patients were studied (142 in the study group vs 134 controls). Albumin was measured in 8-h overnight urine collection throughout pregnancy using radioimmunoassay technique. The pregnant women, in both the study and control groups demonstrated a statistically significant increase in albumin excretion rate in the second and third trimester compared with the first. Using logistic and linear regression models, the presence of microalbuminuria in the early third trimester was proven to be predictive of severe disease (odds ratio 2.1, confidence interval (CI) 1.26-3.53) and birth weight (R2 = 0.7, P < 0.05) in the study group. Intrauterine growth retardation and neonatal outcome were less predictable. With the introduction of radioimmunoassays, we believe severe disease can be predicted by detecting microalbuminuria in the early third trimester of pregnancy in high risk patients.

Microalbuminuria as an early predictor of hypertensive complications in pregnant women at high risk

The value of microalbuminuria in predicting hypertensive complications in pregnant patients at high risk was tested in a prospective trial. A secondary aim was to compare the urinary albumin excretion rate between high risk hypertensive pregnant patients (study group) and pregnant patients at high risk of other complications, normal pregnant subjects, and nonpregnant subjects. Over the last 5 years, 276 patients were studied (142 in the study group v 134 controls). Albumin was measured in an 8-hour overnight urine collection throughout pregnancy using a radioimmunoassay technique. The pregnant women in both the study and control groups demonstrated a statistically significant increase in albumin excretion rate in the second and third trimesters compared with the first. Mean albumin excretion rate values were significantly higher in the study group (P = 0.0001). Using logistic and linear regression models, the presence of microalbuminuria in the early third trimester was proven to be predictive of hypertensive complications (odds ratio, 2.1; confidence intervals, 1.26 to 3.53) and birth weight (R2 = 0.7, P < 0.05) in the study group. Intrauterine growth retardation and neonatal outcome were less predictable. With the introduction of radioimmunoassays and in light of these significant clinical results, we believe that high-risk patients in whom abnormal proteinuria develops usually have a microalbuminuric phase weeks earlier, and this test has some predictive value for severe disease. In addition, the accepted definition of gestational proteinuria should be reconsidered.

Renal effects of moderate hypercholesterolaemia in uninephrectomized rats

Animal studies have shown that a 4-6-fold increase in serum cholesterol aggravates pre-existing renal injury. We studied the renal effects of moderate hypercholesterolaemia over a period of 18 weeks in uninephrectomized rats. Animals were allocated to two groups; the group 1 rats were fed a normal diet, as controls, and the group 2 rats were fed a high cholesterol diet containing 3% cholesterol and 1% sodium cholate by weight. The serum total cholesterol was higher in group 2 than in controls being 2.5 +/- 0.4 vs. 1.0 +/- 0.1 mmol l-1 at 9 weeks and 2.1 +/- 0.3 vs. 1.1 +/- 0.2 mmol l-1 at 18 weeks (p < 0.05 for both). Serum high density lipoprotein cholesterol levels were similar in both groups. The mean systolic blood pressure was higher in group 2 than in controls, at 145 +/- 9 vs. 137 +/- 8 mmHg (p < 0.05) by 13 weeks and 146 +/- 6 vs. 136 +/- 4 mmHg (p < 0.05) at 18 weeks. Serum creatinine and glomerular filtration rates were similar in both groups. Urine protein excretion remained within the normal range in both groups. Histological examination at 18 weeks showed diffuse fatty changes in the liver cells and prominent vacuolization of renal tubule cells in the group 2 rats. Nevertheless, the glomeruli were normal. There was no significant difference in mean glomerular volume between group 2 rats (1.20(-3) +/- 0.09(-3) mm3) and controls (1.36(-3) +/- 0.10(-3) mm3). Thus moderate hypercholesterolaemia for 18 weeks in uninephrectomized rats resulted in a mild elevation in blood pressure, but did not affect glomerular volume or glomerular histology, in spite of the deleterious effects on liver and renal tubule cells. We assume that extremely high levels of serum cholesterol are required to induce glomerulosclerosis in the rat.

Prostaglandin metabolism in the yolk sacs of normal and diabetic pregnancies

The malformations commonly found in fetuses of diabetic mothers occur before the 7th week of pregnancy, when fetal nutritional needs are met largely by the yolk sac. The diabetic milieu has been hypothesized to cause a disruption in the metabolism of arachidonic acid and phosphatidylinositol turnover, leading to a reduction in prostaglandin levels. In this study we evaluated how the diabetic milieu affects yolk-sac prostaglandin levels. We used ultrasound to characterize and guide aspiration of the yolk sacs of eight diabetic and 12 healthy women prior to elective abortion. In addition, we studied the yolk sacs of two healthy women in whom pregnancy termination was carried out by hysterectomy. All fetuses were between 8 and 10 weeks gestational age at the time of pregnancy termination. The yolk-sac prostaglandin E2 levels were measured using radioimmunoassay. We found that the yolk-sac diameters of diabetic women were 1.2 mm larger than those of normal women. Furthermore, the mean prostaglandin E2 level in healthy women was 3605 pg/ml, whereas prostaglandin was undetected in all the yolk sacs of diabetic women (p < 0.001). While this study suggests that defective yolk-sac metabolism of prostaglandins is one of the mechanisms responsible for diabetic embryopathy, further research is necessary to place yolk-sac enlargement and the role of prostaglandins in perspective.

Ovarian angiotensin-converting enzyme activity in humans: relationship to estradiol, age, and uterine pathology

The present study was designed to measure angiotensin-converting enzyme (ACE) activity in the human ovary and in serum and to relate this activity to age, serum estradiol levels, and uterine and endometrial pathology. ACE activity was determined in 56 females by a radiometric assay using [3H]hippuryl-glycyl-glycine as substrate. Ovarian ACE activity, but not serum ACE, was found to increase with age (P < 0.01) and was significantly greater in postmenopausal subjects (n = 31; 1.35 +/- 0.05 nmol/mg.min) than in subjects with active ovaries (n = 21; 0.65 +/- 0.2 nmol/mg.min; P = 0.0033). Ovarian ACE activities in fertile women in the preovulatory phase (n = 14) and the postovulatory phase (n = 7) were not statistically different (0.66 +/- 0.23 and 0.63 +/- 0.17 nmol/mg.min, respectively). Serum ACE activities were similar in females with active and nonactive ovaries (87.6 +/- 5.0 vs. 81.7 +/- 5.3 nmol/mL-min, respectively). Serum estradiol levels in fertile women were significantly higher than those in postmenopausal women (P = 0.0023). Serum estradiol levels were negatively correlated with age (r = -0.46; P = 0.0041) and were not correlated with either serum ACE activity (r = 0.080; P = NS) or ovarian ACE activity. In summary, human ovarian ACE activity, but not serum ACE, is positively correlated with age. Serum estradiol levels decrease with age, but are not correlated with either ovarian or serum ACE activity. Endogenous serum estradiol levels had no apparent effect on ovarian or serum ACE activity. The presence of uterine pathology affects ovarian ACE activity. The cause of the increased ovarian ACE activity is not clear, but may be related to the aging process.

Sodium-lithium countertransport: a predictor of diabetic nephropathy in Jewish insulin-dependent diabetes mellitus patients of different ethnic origin?

Diabetic nephropathy in Jewish insulin-dependent diabetes mellitus (IDDM) patients has been found to correlate to their ethnic origin. It has also been found that increased sodium-lithium countertransport (SLC) in erythrocytes, as a genetic marker for essential hypertension, may identify those patients at risk for diabetic nephropathy. The purpose of this study was to investigate a possible correlation between this genetic marker and the ethnic origin of Jewish IDDM patients and their parents and the risk for developing diabetic nephropathy. Although SLC was slightly increased in IDDM patients with microalbuminuria, SLC was not correlated with the existence of diabetic nephropathy nor with the ethnic origin and blood pressure of these Jewish IDDM patients. Thus, other genetic factors may play a role in the different prevalence of diabetic nephropathy in Jewish IDDM patients of different ethnic origin.

Diabetic nephropathy and pregnancy: the effect of ACE inhibitors prior to pregnancy on fetomaternal outcome

BACKGROUND

Diabetic nephropathy is associated with an increase in perinatal mortality and morbidity in uncontrolled pregnant patients. Recently angiotensin-converting enzyme inhibitor (ACE-I) was shown to improve the disease status in non-pregnant subjects. The purpose of this study was to examine the effect of prepregnancy treatment of insulin-dependent diabetes mellitus (IDDM) nephrotic women with captopril angiotensin converting enzyme inhibitor (ACE-1), on maternal renal function throughout pregnancy and on the fetomaternal outcome.

METHODS

Eight IDDM nephrotic patients planning pregnancy were treated with captopril for a minimum of 6 months prior to conception together with intensive insulin management. Conception was allowed when proteinuria was < 500 mg/day and euglycaemia was achieved. At conception captopril was discontinued.

RESULTS

At the beginning of captopril treatment, proteinuria was 1633 +/- 666 mg/day. At conception, proteinuria dropped to 273 +/- 146 mg/day (P = 0.0000) and increased gradually over the three trimesters to 593 +/- 515, 783 +/- 813, and 1000 +/- 1185 mg/day respectively (P = 0.2 between the trimesters); declining to 619 +/- 411 mg/day (P = 0.0002 vs conception) 3 months after delivery. Only in two patients (25%) did proteinuria exceed 1000 mg/day during pregnancy. There was no significant change in any of the other renal function tests: CCT, serum creatinine, uric acid, K+ and blood pressure. However, there were three cases of PET just prior to delivery. Maternal glycaemic control improved significantly prior to conception (P = 0.002) and remained euglycaemic (reflected by daily glucose profile, HbA1C and fructosamine) throughout gestation. Perinatal outcome was excellent.

CONCLUSION

Captopril treatment before pregnancy has a prolonged protective effect on maternal renal functions during pregnancy and results in a favourable maternal-fetal outcome.

Yolk sac concentration of prostaglandin E2 in diabetic pregnancy: further clues to the etiology of diabetic embryopathy

Fetal malformation associated with maternal diabetes occurs before the seventh week of pregnancy. Current hypotheses suggest that the diabetic milieu causes a reduction in phosphatidylinositol turnover, leading to a disruption in the arachidonic acid cascade and resulting in a deficiency of prostaglandins, particularly prostaglandin E2. This in turn results in a wide variety of congenital anomalies. This hypothesis has not been tested experimentally in humans. The yolk sac is thought to be the most important source of nutrition in early pregnancy. We sought to compare yolk sac prostaglandin levels in normal and diabetic women. Under ultrasonographic guidance, yolk sacs were aspirated form 8 normal and 12 diabetic women ranging from 8 to 10 weeks gestational age prior to elective abortion. Prostaglandin E2 levels were determined using RIA. The mean prostaglandin E2 level in normal controls was 3605 pg/mL, and was undetected in all of the yolk sacs aspirated from diabetic women (P < 0.001). Yolk sac diameter in diabetic pregnancies was 1.2 mm larger than that of normal pregnancies. The functional and morphological changes demonstrated in this study may increase our understanding of the pathophysiology of diabetic embryopathy.

Microalbuminuria: prognostic and therapeutic implications in diabetic and hypertensive pregnancy

Microalbuminuria is defined as urinary excretion of albumin that is persistently above normal, although below the sensitivity of conventional semiquantative test strips. Several studies have reported that Type 1 diabetic patients with microalbuminuria are apparently more likely to develop diabetic nephropathy eventually progressing to renal failure. Microalbuminuria is also a strong predictor of mortality in Type 2 diabetes, and is correlated with increased blood pressure in patients with benign essential hypertension. Radioimmunoassay revealed a significantly higher urinary albumin excretion rate in normal pregnant women in the third trimester of pregnancy, compared to the second and first, and compared to non-pregnant women. Microalbuminuria was found in 30% of women who had a record of gestational diabetes mellitus. Published results are controversial regarding the assumption that microalbuminuria is an early predictor of pregnancy-induced hypertensive complications.