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This study investigated plasma brain natriuretic peptide (BNP) levels in normotensive and hypertensive patients with suspected coronary artery disease during radionuclide pharmacological stress testing. Twenty-seven normotensive patients (15 males, aged 63.0+/-4.5 years and 12 females, aged 63.0+/-4.1 years) and 38 essential hypertensive patients (25 males, aged 63.3+/-3.3 years and 13 females, aged 64.6+/-2.6 years) with chest pain and exercise stress testing inconclusive for coronary artery disease underwent myocardial perfusion single-photon emission computed tomography (SPECT) using adenosine infusion. SPECT identified patients without (16 normotensive and 22 hypertensive) and patients with (11 normotensive and 16 hypertensive) transient perfusion defects. Basal BNP levels in normotensive patients without transient myocardial ischemia (3.1+/-1.2 fmol/ml) were significantly (P<0.01) lower than those observed in normotensive patients with transient ischemia (8.2+/-1.2 fmol/ml), whereas BNP levels in hypertensive patients without transient ischemia (8.2+/-1.0 fmol/ml) did not significantly differ from those in hypertensive patients with transient ischemia (8.1+/-2.0 fmol/ml). No significant difference was found in BNP levels between males or females either in normotensive or hypertensive patients without or with ischemia. Adenosine infusion did not significantly change BNP levels in any subject group without or with myocardial perfusion defects. Our findings show that increases in BNP allow early detection of myocardial ischemia in normotensive patients, but not in hypertensive patients with suspected coronary artery disease. Adenosine-induced myocardial ischemia does not affect BNP production already activated by coronary artery disease in normotensive patients and by hemodynamic changes in hypertensive patients.

The synthesis, characterization, and functional in vitro assays in cardiac tissues and smooth muscle (vascular and nonvascular) of a number of 4-imidazo[2,1- b]thiazole-1,4-dihydropyridines are reported. The binding properties for the novel compounds have been investigated and the interaction with the binding site common to other aryl-dihydropyridines has been demonstrated. Interestingly, the novel 4-aryl-dihydropyridines are L-type calcium channel blockers with a peculiar pharmacological behavior. Indeed, the imidazo[2,1- b]thiazole system is found to confer to the dihydropyridine scaffold an inotropic and/or chronotropic cardiovascular activity with a high selectivity toward the nonvascular tissue. Finally, molecular modeling studies were undertaken for the most representative compounds with the aim of describing the binding properties of the new ligands at molecular level and to rationalize the found structure-activity relationship data. Due to the observed pharmacological behavior of our compounds, they might be promising agents for the treatment of specific cardiovascular pathologies such as cardiac hypertrophy and ischemia.

We studied circulating levels of endothelin-1, catecholamines and nitric oxide after a mental arithmetic test in 14 patients with early ischemic lesions of the extremities due to systemic sclerosis and slightly impaired peripheral vascular flow. The test induced an increase (P<0.01) in blood pressure, heart rate, endothelin-1 and catecholamine levels, whereas it did not change the low basal levels of nitric oxide. In healthy subjects (n=20) the test significantly (P<0.01) decreased endothelin-1 without affecting nitric oxide. The low basal levels of nitric oxide and the high plasma concentration of endothelin-1 after psychological stress cannot be explained by an impaired release from the limited ischemic lesions alone. This suggests a diffuse microvascular derangement that aggravates the course of peripheral microvascular ischemic lesions.

The repressor element-1 (RE-1) silencing transcription factor (REST) interacts with an RE-1 cis element and represses the transcription of neuron-specific genes in neuronal progenitors but is down-regulated in post-mitotic neurons. We report that REST expression is modified, in a time-dependent manner, in SH-SY5Y neuroblastoma cells exposed to insulin-like growth factor I (IGF-I), a polypeptide hormone affecting various aspects of neuronal induction and maturation. REST is increased in cells treated with IGF-I for 2 days and then declines in 5-day-treated cells concomitant with a progressive neurite extension. To investigate any role played by REST in neurodifferentiation by IGF-I, we employed an antisense oligonucleotide (AS-ODN) complementary to REST mRNA. In AS-ODN-treated cells, the effects elicited by IGF-I on cell proliferation are not influenced whereas a marked decrease of REST significantly increases neurite elongation without any gross perturbation of neurogenesis. Synapsin I and betaIII-tubulin gene promoters contain an RE-1 motif and their transcription is repressed by REST; both of them are increased in cells exposed to IGF-I for 5 days and further elevated by AS-ODN treatment. A parallel increase of growth cone-associated protein 43, a protein chosen as a neuronal marker not directly regulated by REST, is also observed. Therefore, REST is elevated during early steps of neural induction by IGF-I and could contribute to down-regulate genes not yet required by the differentiation program while it declines later for the acquisition of neural phenotypes. These results suggest a model in which differentiating neuroblastoma cells determine their extent of neurite outgrowth on the basis of REST disappearance.

Twelve patients with chronic critical limb ischemia in whom a spinal cord stimulation (SCS) system had been implanted for at least one year had increased microvascular flow and achieved healing of trophic acral lesions. After switching off the system, the clinical improvement persisted for 10 days and the neurohormonal pattern showed high plasma values of beta-endorphin and Met-enkephalin, normal dynorphin B, endothelin-1 and catecholamines, and low nitric oxide. Met-enkephalin levels were further increased (P < 0.01) immediately after switching on the electrical stimulation again. The persistence of high plasma opioid levels after switching off the spinal cord stimulation explains the absence of subjective complaints and suggests an involvement of opioids in the regulation and improvement of the microcirculation., (Copyright 2004 Elsevier Inc.)

The biocompatibility of polylactic acid (PLA) and polyglycolic acid (PGA) copolymers, employed in manufacturing bone-graft substitutes, is affected by their chemical composition, molecular weight and cell environment, and by the methods of polymerization and processing. Their in vitro bioactivity on human osteoblasts has been investigated very little. We first evaluated the behavior of primary human osteoblasts cultured in close contact with 75:25 and 50:50 PLA-PGA copolymers for 14 days adopting a cell culture system that allowed us to evaluate the influence of direct contact, and of factors released from polymers. The copolymers had no negative influence on cell morphology, cell viability and proliferation. Alkaline phosphatase (ALP) activity and osteocalcin production were also not affected. The initial adhesion of osteoblasts on implant surfaces requires the contribution of integrins, acting as a primary mechanism regulating cell-extracellular matrix (ECM) interactions. We observed that adhesion of osteoblasts to PLA-PGA copolymers, 2h after plating, was reduced by approximately 70% by antibodies capable to block integrin beta(1) and alpha(5)beta(1) complex and only by approximately 30% by an anti-integrin alpha(v) antibody. Therefore, beta(1) integrins may represent a predominant adhesion receptor subfamily utilized by osteoblasts to adhere to PLA-PGA copolymers. These materials do not show any negative influence on cell proliferation and differentiation.

In this study, we examined agonist-induced internalization, recycling and signalling (measure of cAMP levels) of the cloned human nociceptin receptor (hNOP) expressed in CHO-K1 cells. Internalization was proven by a receptor-binding assay on viable cells. The agonist nociceptin/orphanin FQ (NC) promoted rapid internalization of the hNOP receptor (approximately 78% of cell surface receptors were lost after 2 min exposure to 1 microM NC) in a clathrin- and ATP-dependent manner. Internalization was more rapid and marked in CHO-K1 cells than, as we previously reported, in SK-N-BE cells. This difference may be related to higher levels of beta-arrestin isoforms detected in CHO-K1 than in SK-N-BE cells. hNOP receptor internalization was partially reversible and recycling occurred in the presence of the agonist; receptor recycling was dependent on okadaic acid-sensitive phosphatases and was blocked by monensin. Confocal microscopy analysis confirmed the internalization and the recycling back to the plasma membrane of an epitope-tagged hNOP receptor expressed in CHO-K1 cells. These receptors underwent rapid desensitization upon agonist challenge: NC efficacy in inhibiting forskolin-stimulated cAMP production was significantly reduced 10 min after exposure and correlated with the rate of receptor internalization. Moreover, we observed that blockade of hNOP receptor recycling by monensin would cause a more prolonged and relevant desensitization of this receptor. Thus, the dynamic cycle between hNOP receptor activation, internalization and recycling determines the activity of this receptor on the cell surface.

Background: An increased spot urine Na/K ratio (UNa/K) has been found to be related to urinary stone disease in adults with a history of nephrolithiasis and in children with idiopathic hypercalciuria (HC). However, the respective role played by Na and K excretion in the rise of the UNa/K in growing individuals is not well clarified., Methods: The urinary excretion of Na and K was evaluated in fasting morning and 24-hour urine samples of 37 consecutive children with HC and of 21 previously HC children who were normocalciuric at the time of the study (ExHC). None of them had received any dietary or specific drug prescription., Results: In the HC and in the ExHC group, respectively, the Na excretion was 4 +/- (SD) 2.4 and 2.9 +/- 1.3 mmol/kg/day (p = 0.009); the K excretion was 1.1 +/- 0.4 and 1.2 +/- 0.7 mmol/kg/day (p = 0.86); the fasting UNa/K was 3 +/- 1.6 and 2.1 +/- 1 mmol/mmol (p = 0.044), and the 24-hour UNa/K was 4.2 +/- 3.9 and 2.8 +/- 1.5 mmol/ mmol (p = 0.045). The 24-hour UNa/K was significantly higher than the fasting UNa/K in both HC (p = 0.002) and ExHC (p = 0.002) subjects. The 24-hour UNa/K significantly increased with age in both HC (p = 0.02) and ExHC (p = 0.015) children. The K excretion significantly decreased with age in HC (p = 0.0001) and ExHC (p = 0.005) subjects, as well as with body weight gain in HC (p = 0.005) and ExHC (p = 0.0001) children and with increasing body height in HC (p = 0.006) and ExHC (p = 0.001) subjects. In neither group was the K excretion significantly related to body mass index Z score nor to height Z score. No significant relation resulted between Na excretion and age, body weight and height, and body mass index Z score and height Z score., Conclusions: HC children have a higher Na excretion as well as a higher fasting and 24-hour UNa/K than ExHC children, but no different K excretion. Meals are accompanied by a significant rise in UNa/K. The rise in UNa/K with age is mostly due to a decrease in K excretion which possibly depends on childhood body growth., (Copyright 2002 S. Karger AG, Basel)

Unlabelled: Obesity is a typical example of a complex multifactorial disease arising from behavioural, environmental and genetic factors that may affect individual responses to dietary intake and physical activity. Observational, longitudinal dietary interventional studies in obese patients present contrasting reports on the predictive value of baseline leptin levels. We report on the effect of a weight reduction programme in three different groups of obese children (82 patients in all) assembled on the basis of their baseline leptin levels adjusted for body mass index (BMI), gender and pubertal development. The effectiveness of this programme was decreased in patients with relative hyperleptinaemia or hypoleptinaemia compared to children with baseline leptin levels appropriate to BMI gender and pubertal development., Conclusion: Information gained from leptin assays could provide predictive insight into an individual's ability to lose body fat and may therefore have important implications for our approach to the treatment and prevention of childhood obesity.

Nociceptin/orphanin FQ (NC) has been proposed as endogenous ligand of the opioid receptor-like 1 (ORL1) receptor. We investigated NC-induced internalization and recycling of the ORL1 receptor in SK-N-BE human neuroblastoma cells. Internalization was proven by receptor binding assay on viable cells. NC promotes a time- and concentration-dependent internalization of the ORL1 receptor (57% of cell surface receptors are lost after 30 min exposure to 1 microM NC) in a clathrin- and ATP- dependent manner. After 30 min exposure to NC, ORL1 receptor internalization is partially reversible and recycling is dependent on acid phosphatases. Over-expression of beta-arrestin 2 increases NC-promoted internalization of the ORL1 receptor. These events contribute to NC signaling in neuronal cells through sequestration and recycling of the ORL1 receptor.

Cocaine- and amphetamine-regulated transcript (CART) inhibits feeding and induces the expression of c-Fos in hypothalamic areas implicated in appetite regulation. Furthermore, the CART peptide is found in neurons regulating sympathetic outflow, which in turn play an integral role in regulating body temperature and energy expenditure. The CART gene was screened by single-strand conformation polymorphism and automatic sequencing in 130 (72 girls) unrelated obese Italian children and adolescents. Their Z-scores (mean +/- SD) of relative to BMI percentiles was 3.9 +/- 1.8, and the average age at obesity onset was 4.7 +/- 2.6 years. Two previously described silent polymorphisms were found in the 3' untranslated region: an adenine deletion at position 1457 in 9 patients (allele frequency 0.035) and an A/G substitution at position 1475 in 11 patients (allele frequency 0.042). We found no difference between the obese patients heterozygous for one of these polymorphisms and those patients homozygous for the wild allele with respect to their age of obesity onset, BMI Z-scores, and leptin levels. A missense mutation of G729C resulting in the substitution of Leu with Phe at codon 34, within the NH2-terminal CART region, has been detected in the heterozygous state in a 10-year-old obese boy who has been obese since the age of 2 years. The patient belongs to a large family of obese subjects. The mutation cosegregated with the severe obesity phenotype over three generations and was not found in the control population. Resting metabolic rates were lower than expected in the propositus (-14%) and his mother (-16%), who carried the mutation. Leucine at codon 34, conserved in this position in the human and in the rat sequences, immediately precedes a couple of lysine residues that may well represent a dibasic processing site. The Leu34Phe mutation might alter the susceptibility to proteolysis of this potential processing site, likely altering the CART effect on thermogenesis and energy expenditure.

Objective: We assessed the risk for the occurrence of renal damage in children with vesicoureteric reflux (VUR)., Study Design: We reviewed the records of 187 consecutive children, aged 3.8 +/- (SD) 2.8 years, with unilateral primary VUR diagnosed after urinary tract infection (UTI). Dimercaptosuccinic acid renal scintigraphy was performed 4 to 6 months after the last UTI. Three patterns of renal damage were identified: global reduction (GR) of renal radionuclide uptake (20% to 40% of relative uptake), focal defects (FD) in uptake, and shrunken (relative uptake <20%) kidney (SK). We assumed that in these subjects FD indicated postpyelonephritic damage and that GR indicated congenital renal damage., Results: Scintigraphic renal damage of any type was present in 36.9% of the refluxing and in 3.2% of the nonrefluxing kidneys (odds ratio [OR], 17.6; 95% CI, 7.4 to 41.9). FD were present in 15.5% and 2.7% (OR, 6.7; CI, 2.5-17.6), GR in 19% and 0.5% (OR, 44.3; CI, 6.1 to 327.2), and SK in 6.9% and 0%, respectively. Patients with severe VUR showed a higher probability of renal damage than those with nonsevere VUR., Conclusions: In children with UTI and VUR, the refluxing kidney is most at risk of both congenital and acquired renal damage, and this risk increases with severity of reflux.

Plasma opioid peptides, norepinephrine, atrial natriuretic factor (ANF) and blood pressure (BP) were assessed in 24 chronic obstructive pulmonary disease patients with acute respiratory failure. Hypoxemic-hypercapnic patients had high BP, beta-endorphin, Met-enkephalin and dynorphin B, whereas hypoxemic-normocapnic and hypoxemic-hypocapnic patients showed normal BP, high beta-endorphin, and normal Met-enkephalin and dynorphin B. Norepinephrine and ANF were high in all patients, particularly in hypoxemic-hypercapnic patients. Infusion with the opioid antagonist naloxone hydrochloride significantly increased systolic blood pressure (SBP) in hypoxemic-hypercapnic (182.0 +/- 3.2 versus 205.1 +/- 3.0 mmHg; P < 0.01), hypoxemic-normocapnic (149.3 +/- 1.8 versus 169.1 +/- 2.2 mmHg; P < 0.01) and hypoxemic-hypocapnic (147.3 +/- 1.3 versus 166.8 +/- 2.2 mmHg; P < 0.01) patients, norepinephrine in hypoxemic-hypercapnic patients (3583.2 +/- 371.8 versus 5371.3 +/- 260.0 fmol/ml; P < 0.01), and reduced ANF in hypoxemic-normocapnic (18.3 +/- 0.8 versus 11.9 +/- 1.0 fmol/ml; P < 0.05) and hypoxemic-hypocapnic (18.1 +/- 1.2 versus 12.1 +/- 2.1 fmol/ml; P < 0.05) patients. These results indicate that the endogenous opioid system attenuates SBP responses in acute respiratory failure by affecting norepinephrine or ANF release.

Objective: Idiopathic hyperuricosuria (HU) was previously reported in only a limited number of children with hematuria. We aimed to outline the clinical presentation and natural history of HU not only in children with hematuria, but also in those with dysuria and/or recurrent abdominal/flank pain and a family history of urolithiasis., Study Design: Retrospective analysis of data at diagnosis from 102 consecutive children with HU and outcome analysis of 26 of them who were followed >/=1 years (mean: 3.1) with no specific therapy., Results: Sixty-one participants had HU and 41 had HU + hypercalciuria. Fifty-two patients had no hematuria among the presenting symptoms, more than one third had normal urinalysis at our first examination, one half had microcalculi (<3 mm in diameter) at renal sonography, and 12% had stones (4-18 mm). Thirty participants of the 39 with no hematuria at our first examination (77%) showed microcalculi or calculi at renal sonography. The patients with microcalculi were significantly older than were those without microcalculi. During the follow-up, 4 of 26 children never had hematuria and 8 had no hematuria during most of the follow-up period. Two patients who had a calculus at first visit and 3 who formed calculi 4 to 12 mm in diameter, after 1 to 3.5 years subsequently passed them in the urine., Conclusions: The lack of hematuria is not predictive of absence of urolithiasis. Therefore, it may be misleading to judge on the efficacy of a given therapy only based on disappearance of hematuria. HU and hypercalciuria have to be suspected in children with dysuria and those with recurrent abdominal/flank pain and familial history of urolithiasis, although they have no hematuria.

Background: Although linkage studies strongly suggest that proopiomelanocortin (POMC) alterations could play a role in the genetic predisposition to obesity, systematic POMC mutational analysis did not completely confirm this hypothesis., Objectives: To verify the presence of mutations of the POMC coding region in Italian children with very early onset obesity., Subjects and Methods: Eighty seven unrelated Italian obese children and adolescents were studied. Mean age at obesity onset was 4.7+/-2.5 y. The POMC gene coding region was screened using single-strand conformation polymorphism (SSCP) analysis. Bi-directional automatic sequencing of PCR products was performed for all individuals who showed an aberrant SSCP pattern., Results: Three new mutations have been identified in the heterozygous state in three patients: (a) G3834C, resulting in the substitution of Ser with Thr at codon 7 within the POMC signal peptide; (b) C3840T, resulting in the substitution of Ser with Leu at codon 9 of the pre-proopiomelanocortin signal peptide; and (c) C7406G, producing the substitution of Arg with Gly at codon 236 within the beta-endorphin peptide. A polymorphism consisting of a 9 bp insertion, AGC AGC CGC, between position 6997 and 6998 has been found at the heterozygous state in nine patients. They showed leptin levels adjusted for BMI, gender and pubertal stage significantly higher than obese subjects homozyous for the POMC wild-type allele., Conclusions: Mutations in codons 7 and 9 of the signal peptide may alter the translocation of the pre-proopiomelanocortin into the endoplasmic reticulum and, therefore, can be implicated in obesity. Although further studies are required, the polymorphism between position 6997 and 6998 may represent one of the genetic variations that explain the linkage between obesity and POMC. International Journal of Obesity (2001) 25, 61-67

The synthesis of cis-(+)- and cis-(-)-N-ethyleneamino-N-nordeoxymetazocine and cis-(-)-N-normetazocine analogues is described and their affinities to sigma1, sigma2 and kappa opioid receptors are evaluated. The cis-(+)-deoxy compounds displayed high sigma/kappa selectivity with nanomolar K(i) values for sigma1 receptors, whereas in the cis-(-)-N-normetazocine series the compound (-)-7b was found to bind with nanomolar affinity to the kappa opioid receptor (K(i)=21.5 nM). Compound (-)-7b showed good selectivity for the kappa opioid receptor in comparison to the sigma1 and sigma2 sites and to the mu and delta opioid receptors. A correlation of the binding affinities between cis-(-)- and cis-(+)-N-deoxynormetazocine derivatives show that both isomers of the deoxy analogs have similar sigma1 and sigma2 binding profiles as the cis-(+)-N-normetazocine derivatives.

Idiopathic hypercalciuria (IHC) has been reported mainly in children with hematuria in the 1980s and early 1990s, when renal sonography was just becoming routine. The presence of microcalculi, i.e., of hyperechogenic spots < 3 mm in diameter in renal calyces, was not taken into account in those studies. We attempted to outline clinical presentation and natural course of IHC not only in children with hematuria, but also in those with dysuria and/or recurrent abdominal/flank pain and a family history of nephrolithiasis, taking into account the finding of microcalculi. We analyzed retrospectively the data at diagnosis from 74 consecutive children aged 2.4-18 years (mean 8.6) with IHC (calciuria 4.1-15.1 mg kg-1 24 h-1, mean 6.1) and the outcome of 30 of them who were followed > or = 1 years (mean 3.2) with no specific therapy. At diagnosis, 38 patients (51%) had no hematuria, 42 (57%) had microcalculi and four (5%) had calculi. Of the patients with normal urinalysis, 71% had microcalculi or stones. The subjects with microcalculi and those with stones were significantly older than those without microcalculi and stones (P = 0.004 and 0.007). A normal urinalysis at our evaluation and a history of abdominal/flank pain were significantly more frequent in patients with microcalculi than in those without (P = 0.02 and 0.0001, respectively). During the follow-up, four of 30 patients formed stones 1-3 years after first diagnosis of IHC. More than half of children with IHC have microcalculi. The risk of formation of microcalculi or stones increases with age. The lack of hematuria does not exclude the presence of microcalculi or calculi. Hypercalciuria has to be suspected in children with dysuria and/or recurrent abdominal flank pain and a family history of nephrolithiasis, even when they have no hematuria.

We studied the prevalence of a history of nephrolithiasis in first- and second-degree relatives of 74 children with hypercalciuria (HC), 61 with hyperuricosuria (HU), and 41 with HC plus HU, and in a control population of 261 children with different diseases. Family history of nephrolithiasis was found in 69% of HC, 75% of HU, 78% of HC plus HU, and 22% of control patients. The prevalence was not different among HC, HU, and HC plus HU groups, but was significantly higher in each study group than the control group (P=0.0001). Body mass index >95th percentile was found in only 4.7% of the patients with HC or HC plus HU. Calculi (>3 mm in diameter) were present in 8.9% of the patients with a family history of nephrolithiasis and in 9.4% of those with no family history (P=0.85). Microcalculi (<3 mm in diameter) were found by sonography in 56.6% of the patients with and in 53.3% of those without a family history of nephrolithiasis (P=0.83). Children with HC and/or HU have a strong familial prevalence of nephrolithiasis. Obesity does not seem to affect the association of familial nephrolithiasis and hypercalciuria in children. The presence of nephrolithiasis in families of children with HC and/or HU is not associated with a higher rate of formation of calculi or microcalculi.

Bile acids may play a role in the pathogenesis of intestinal inflammation by activating the signalling pathways that control cell proliferation, among other cell systems. We investigated the action of different bile acids, particularly chenodeoxycholic acid (CDCA) and ursodeoxycholic acid (UDCA), on steady-state and transcriptional regulation of the protooncogene c-fos, involved in the regulation of cell proliferation and differentiation, in colon carcinoma Caco-2 cells. Specific bile acids had a stimulatory effect of on the expression of c-fos mRNA. This proved to be concentration- and time-dependent and may be partly due to an increase in the rate of transcription of the corresponding gene rather than to any change in the stability of mRNA. In Caco-2 cells exposed to 250 microM CDCA for 1 h a maximal increase of c-fos mRNA ( approximately 2.5-fold induction over the control) was observed; deoxycholic acid (DCA; 250 microM) and lithocholic acid (LCA; 250 microM) were less effective (approximately 2-fold induction over the control). UDCA and cholic acid (CA) did not modify c-fos gene expression in this cell line. Finally, we investigated the role of protein kinase C (PKC) in transcriptional regulation of the c-fos gene by bile acids. Although induction of c-fos by 12-O-tetradecanoyl 13-acetate (10 nM), a potent PKC activator, was completely antagonised by bis-indolyl-maleimide I (1 microM); only about 40% of the bile acid-mediated rise in c-fos mRNA was blocked. Thus it appears that PKC, as well as other signalling pathways, is involved in CDCA-, DCA- and LCA-induced c-fos gene expression.

Two novel series of kappa opioid receptor agonist analogues of MPCB-GRRI and MPCB-RRI, hybrid ligands of MPCB ((-)-cis-N-(2-phenyl-2-carbomethoxy)cyclopropylmethyl-N-normetazocine ) and of the C-terminal fragments of dynorphin A(1-8), have been synthesized. The critical functional groups of the peptide fragments of hybrid compounds were maintained, and the binding affinities and selectivities for compounds 1-40 to mu, delta, and kappa opioid receptors were analyzed. Compounds 15 and 16, MPCB-Gly-Leu-NH-(CH(2))(n)()-NH-C(=NH)-C(4)H(9) (n = 5, 6), displayed high affinity and selectivity for kappa opioid receptors (K(i)(kappa) = 6.7 and 5.3 nM, K(i)(mu)/K(i)(kappa) = 375 and 408, and K(i)(delta)/K(i)(kappa) = 408 and 424, respectively). Since kappa agonists may also cause psychotomimetic effects by interaction with sigma sites, binding assays to sigma(1) sites were performed where compounds 15 and 16 showed negligible affinity (K(i) > 10 000). Compounds 15 and 16 were further characterized in vivo and showed potent antinociceptive activity in mouse abdominal constriction tests (ED(50) = 0.88 and 1.1 mg/kg, respectively), fully prevented by nor-BNI. Thus, these novel analogues open an exciting avenue for the design of peptidomimetics of dynorphin A(1-8).

Purpose: We distinguished the scintigraphy pattern of congenital reflux nephropathy from that of acquired scarring in children with primary vesicoureteral reflux., Materials and Methods: We retrospectively evaluated the frequency and pattern of renal scintigraphy abnormalities in 41 patients with prenatally detected primary vesicoureteral reflux and in 322 with a mean age plus or minus standard deviation of 3.6 + or - 1 years in whom primary reflux was detected after urinary tract infection. Dimercapto-succinic acid scintigraphy was performed 4 to 6 and 1 to 4 months after reflux was diagnosed and/or the infection was cured in patients with urinary tract infection and prenatal detection, respectively., Results: We identified 3 patterns of renal damage, including overall decreased uptake of renal radionuclide that was 20% to 40% of relative uptake, focal defects in uptake and shrunken kidney with relative uptake less than 20%. Scintigraphy revealed renal damage in 12 prenatally detected cases of vesicoureteral reflux, including overall decreased uptake in 58% and shrunken kidney in 42%, and in 111 cases of reflux detected at urinary tract infection, including overall decreased uptake in 50%, uptake focal defects in 37% and shrunken kidney in 13%. In the urinary tract infection group overall decreased uptake was present in 25 of 90 boys and in 40 of 232 girls (p = 0.05). Of these children 15% of the girls had uptake focal defects and 17% had overall decreased uptake. Overall decreased uptake and uptake focal defects were significantly more common in kidney-ureter units with reflux grade 4 or greater than in those with grade 3 or less (p = 0. 00001 and 0.027, respectively)., Conclusions: When assuming that overall decreased radionuclide uptake indicates congenital reflux nephropathy and uptake focal defects indicate postnatal acquired scarring, congenital reflux nephropathy appears to be an important cause of renal damage in children with primary vesicoureteral reflux even beyond the neonatal age and even in girls. This finding is of interest because postnatally acquired scarring may but congenital reflux nephropathy may not be prevented.

We compared the accuracy of isotope cystography (IC) and fluoroscopic cystourethrography (FC) in detecting vesicoureteric reflux (VUR) in children. FC and IC were performed in 124 children, 56 boys and 68 girls, aged 1 month to 9.2 years (mean 2.1 years), admitted consecutively for suspected VUR over a 10-month period. VUR was diagnosed by one or both studies in 51 of 124 (41%) patients. The two methods were concordant for the detection of VUR in 84% of kidney-ureter units and in 93% for the detection or exclusion of severe VUR. IC detected VUR more accurately than FC, both when all grades of VUR were considered together (P=0.00001) and when only severe reflux was considered (P=0.004). VUR was missed by FC in 23 of 51 (45%) subjects. Of those 23, 12 had severe VUR detected on one side at least by IC. VUR was missed by IC in 3 subjects. IC is significantly more accurate than FC in the initial diagnosis of VUR, even of severe grade. IC is the method of choice for the first diagnosis of VUR. Boys with VUR diagnosed by IC also need FC to investigate for posterior urethral valves.

A series of 1-phenyl-2-cyclopropylmethylamines structurally related to (+)- and (-)-MPCB were synthesized and their binding affinities for sigma1, sigma2, opioid and dopamine (D2) receptors were evaluated. Substitution of the cis-N-normetazocine with different aminic moieties provided compounds with high affinity and selectivity for sigma binding sites with respect to opioid and dopamine (D2) receptors. The observed increase in sigma2 affinity as compared to the parent (+)-MPCB, supports the idea that the particular stereochemistry of (+)-cis-N-normetazocine affects sigma1 selectivity but does not affect sigma1 affinity. The (+/-)-cis isomers of methyl 2-[(1-adamantylamino)methyl]-1-phenylcyclopropane-1-carboxyl ate (18) displayed a higher affinity and selectivity for the sigma1 and sigma2 receptor subtypes compared to the (+/-)-trans 19. Interestingly, the enantiomer (-)-cis 18 displayed a preference for sigma1 receptor subtype whereas the (+)-cis 18 did for sigma2. These results prompt us to synthesize compounds with modification of nitrogen and carboxyl groups. The compounds obtained showed high affinities and selectivity for sigma sites. Moreover, modifications of carboxyl groups provided compounds with the highest affinities in the series. In particular, compound 25 with reverse-type ester showed a Ki of 0.6 and 4.05 nM for sigma1 and sigma2 binding sites, respectively.

Nandrolone, an anabolic androgenic steroid, reduced delta opioid receptor (DOR) mRNA and the number of DOR binding sites in two neuronal hybrid cell lines: NG 108-15 and the GT1-1 cells. Both cell lines express DOR but only GT1-1 cells express androgen receptors (AR). DOR mRNA levels were maximally decreased by approximately 45% in NG 108-15 cells and by approximately 38% in GT1-1 cells exposed for 24 h to 10(-6) M nandrolone. This action was partly due to a decrease in the rate of transcription of DOR mRNA and was not blocked by the androgen antagonist flutamide. Flutamide antagonized the repression of AR mRNA induced by nandrolone. The synthetic glucocorticoid dexamethasone (10(-6) M) did not modify DOR steady-state transcripts in either cell line. These results suggest that nandrolone presumably regulate DOR mRNA levels through mechanisms independent of the androgen and glucocorticoid receptors.

Cyclic voiding cystourethrography (CVC) enhances the detection of vesicoureteric reflux (VUR). We investigated whether more-severe VUR may be overlooked, and whether older children are at risk of having their VUR missed with the conventional single-cycle study. Three hundred and seventy patients, 168 boys and 202 girls aged 1 month to 16 years, consecutively admitted over 1 year for suspicion of VUR, underwent two complete cycles of filling and voiding CVC. One hundred and four subjects, 33 boys and 71 girls, were older than 3 years (mean age 5.7 years, range 3.2-16 years). Sixty-six refluxing ureters from 51 patients were identified in the first cycle and 61 refluxing ureters from 45 patients were identified only with the second cycle. Four instances of grade IV VUR in 4 patients and three of grade V VUR in 3 patients were overlooked completely in the first cycle. Seven episodes of VUR < or = grade III from 5 patients diagnosed in the first cycle were upgraded to > or = grade IV at the second cycle. The presence of VUR was identified only in the second cycle in 35 of 74 subjects aged < or = 3 years and in 10 of 22 aged > 3 years (not significant). Of the 10 children aged > 3 years, 2, who had diagnosis only at the second cycle, had > or = grade IV VUR. More-severe VUR may be overlooked or down-graded in a single-cycle study. Two-cycle CVC is also useful in children older than 3 years.

The aim of the present study is to evaluate blood levels (PbB) in a group of 500 (245 M, 255 F) children and adolescents of Campania (Italy) aged from 0.197 to 16.915 years, 269 (136 M, 133 F) of whom lived in urban zones and 231 (109 M, 122 F) in rural zones. PbB was assayed by electrothermal atomic absorption spectroscopy. The parents of the examined subjects children were interviewed about common risk factors for lead exposure using a standardized questionnaire. The PbB of children living in urban zones were significantly higher than the PbB of those living in rural zones (60.0 +/- 3.0 mg/L vs. 40.0 +/- 2.0 mg/L, p < 0.001). A PbB higher than 100 mg/L was found in 27 children (5.4%). We observed a significant correlation between age and PbB (p < 0.001, r = 0.529). Our data regarding children and adolescents demonstrate that the prevalence of PbB higher than 100 mg/L is greater in children living in urban areas (6.89%) than in subjects living in rural areas (3.89%). The findings can be explained by the higher presence of risk factors of Pb exposure in urban areas. Our data, if compared with those of previous studies concerning children of Campania, show a clear decrease of PbB. The correlation that we found between age and PbB indicates that long-term exposure at low doses more than a more intensive but short-term exposure seems to be important for the increase of blood lead levels.

Body growth was studied in 32 subjects with vesicoureteric reflux (VUR), diagnosed following the prenatal finding of urinary tract dilatation, who had normal renal filtration function and who received antibacterial prophylaxis by the first few days of life. They were followed for 1-5 years (mean 2.3 years). Most had persistent VUR during the 1st year of life. Body growth performance was compared with that of 94 subjects with VUR diagnosed and treated by us after the neonatal period. During the follow-up period, none of the patients with prenatally detected VUR had a height Z score below -2, nor a weight-for-height index below 90%, and 1 had variations in height Z score >/=1. The difference in the percentage of patients with prenatally detected VUR (1/32) and those with VUR diagnosed and treated after the neonatal period (20/94) who had variations in height Z score >/=1 was significant (P=0.035). Patients with prenatally detected VUR and normal renal filtration function, given antibacterial prophylaxis by the first few days of life, have normal body growth, although VUR still persists.

Calyceal microlithiasis (CM) is characterized by the sonographic finding of hyperechogenic spots less than 3 mm in diameter in renal calyces, and it may be the first step in calculus formation. From January 1992 to January 1998, we have observed 216 children with CM. The present report deals with 34 of them in whom renal sonography was negative at first observation and the diagnosis of CM was made only on repeated sonographic examinations. The presenting symptoms were recurrent abdominal pain, dysuria, and hematuria occurring alone or in combination. Half of the patients had hypercalciuria. A history of urolithiasis in at least one first- or second-degree relative was present in 85% of patients. Renal sonography was repeated after 6-22 months (mean 11) and showed unilateral CM in 16 subjects and bilateral in 18. The finding of CM may be preceded by a period of time when symptoms and/or signs are present while microcalculi are not yet detectable. Repeated ultrasound examinations may be needed not only in patients with hypercalciuria but also in those with recurrent abdominal pain, dysuria, and/or hematuria not associated with hypercalciuria.

We evaluated the effect of one year of supplementation with iron plus zinc (12 mg/day of Fe+++ and 12.5 mg/day of Zn++), zinc alone (12.5 mg/day of Zn++) and placebo on growth and on the iron, zinc, copper and selenium tissue contents in 30 well-selected children of short stature (16 M and 14 F; 4-11 years old). Before and after supplementation, we measured the concentrations of iron, transferrin, ferritin, zinc and copper in serum, of zinc in erythrocytes and leukocytes, and of zinc, copper and selenium in hair, as well as glutathione peroxidase activity in erythrocytes. Before supplementation, ferritin and serum, erythrocyte and hair zinc contents were significantly lower than in age-matched controls, while the other measured indices were in the normal range. Iron plus zinc supplementation caused an improvement in growth rate in all subjects, i.e., the median Z-score increased from -2.22 +/- 0.45 to -0.64 +/- 0.55; (p < 0.01). In the zinc-supplemented group, only the subjects whose ferritin levels were higher than 20 ng/L before supplementation showed a similar improvement of growth rate. Iron plus zinc supplementation could be a reasonable treatment in short, prepubertal children affected by marginal zinc and iron deficiency.

In this study, we examined the presence of sigma1 and sigma2 sites in the rabbit iris-ciliary body by receptor binding and investigated their effects on intraocular pressure (IOP) in albino rabbits. The iris-ciliary body has binding sites for the sigma1-site agonist [3H](+)-pentazocine (Kd = 4.6 nM; Bmax = 212 fmol/mg protein) and sigma2 sites labeled with [3H]1,3-di-o-tolylguanidine (DTG) (Kd = 8. 2 nM; Bmax = 1120 fmol/mg protein). In competition binding studies, (+)-pentazocine and the sigma antagonist NE-100 displayed high affinity for sigma1 sites (Ki = 2.1 and 2.4 nM, respectively), whereas (+)-N-allylnormetazocine (NANM) was less potent (Ki = 178 nM). Unilateral topical (+)-pentazocine (0.01-0.1%) caused a significant dose-related reduction of IOP in ocular normotensive rabbits and in the alpha-chymotrypsin model of ocular hypertension. (+)-NANM was less potent than (+)-pentazocine. Neither compound altered the IOP of the contralateral eye, and their hypotensive activity was blocked by NE-100 that, by itself, had no effect on IOP. (-)-Pentazocine, (-)-NANM, and DTG had no effect on IOP. DTG prevented the hypotensive effect of (+)-pentazocine, suggesting that it acts as a sigma1-site antagonist. sigma-Site ligands did not affect pupil diameter or cause ocular inflammation. Topical [3H](+)-pentazocine reaches the intraocular tissues within 30 min, and its uptake in the iris-ciliary body and retina was significantly reduced by topical pretreatment with NE-100, as expected for a receptor-specific agent. Reverse-phase HPLC confirmed the presence of intact (+)-pentazocine in iris-ciliary body homogenates. sigma1-Site agonists may offer a novel class of agents potentially effective in the control of ocular hypertension.

Objective: The aim of the study was to compare the efficacy and safety of different doses of DDAVP spray treatment (20 to 40 mcg/day) in patients with primary monosymptomatic nocturnal enuresis (defined as three or more wet nights per week)., Material and Methods: 237 patients (152 males, 75 females; age range 5-17 years), with no infections or organic abnormalities of the urinary apparatus and no neurological disorders, were admitted into the trial. The experimental design was planned as an "open study" with five different treatments schedules (5 groups). The daily doses of DDAVP at bedtime in groups 1 and 2 were 20 and 30 mcg, respectively, for 6 weeks. In groups 3 and 4 the daily doses for the first 2 weeks were 20 and 30 mcg, respectively, and then, after a washout period of 2 weeks, the daily doses for the two groups were 30 and 20 mcg, respectively. A dose-response study (20 to 40 mcg/day) was carried out in group 5., Results: DDAVP spray therapy in primary monosymptomatic nocturnal enuresis was found to be resolutive in 70-75% of treated patients. No difference in response was found between the patients treated with the daily dose of 20 and those on 30 mcg. No important reactions were observed in patients treated with DDAVP spray at the different daily dose (20 to 40 mcg) or for different periods of time (up to 6 weeks)., Conclusions: DDAVP spray therapy at a dose of 20 mcg/day was effective in 70-75% of primary monosymptomatic nocturnal enuretics. In non-responders the daily dose of DDAVP should be increased to 30 to 40 mcg.

Blood lead levels were assayed in 261 children (133 males and 128 females) living in Campania, 137 (63 females and 74 males) in urban areas and 124 (65 females and 59 males) in rural zones, aged between 0.197 and 16.863 years. Blood lead determination was carried out by electrothermal atomic absorption spectroscopy. All children were interviewed about common risk factors for lead exposure. PbB (median +/- SD) were significantly higher in the urban than in the rural population (6.0 +/- 0.31 vs 3.75 +/- 0.25 micrograms/100 ml; p < 0.001). The frequency of blood lead level above 10 micrograms/100 ml was 4.21% in our tested group, i.e., significantly lower than in previous studies. A significant direct correlation between blood lead levels and age was found (r = 0.47; p < 0.001). In agreement with the literature on this subject, our findings show a significant reduction with time, of blood lead levels of children and adolescents in our region. Time of exposure more than total dose seems to be important for the increase of blood lead level.

In this study we employed the neuroblastoma x glioma NG 108-15 cell line as a model for investigating the effects of long-term activation of cannabinoid receptors on delta opioid receptor desensitization, down-regulation and gene expression. Exposure of NG 108-15 cells to (-)-delta9-tetrahydrocannabinol (delta9-THC) reduced opioid receptor binding, evaluated in intact cells, by approximately 40-45% in cells exposed for 24 h to 50 and 100 nM delta9-THC and by approximately 25% in cells exposed to 10 nM delta9-THC. Lower doses of delta9-THC (0.1 and 1 nM) or a shorter exposure time to the cannabinoid (6 h) were not effective. Down-regulation of 6 opioid receptors was not observed in cells exposed for 24 h to pertussis toxin (PTX) and then treated for 24 h with 100 nM delta9-THC. In cells that were exposed for 24 h to the cannabinoid, the ability of delta9-THC and of the delta opioid receptor agonist [D-Ser2, Leu5, Thr6]enkephalin to inhibit forskolin-stimulated cAMP accumulation was significantly attenuated. Prolonged exposure of NG 108-15 cells to 100 nM delta9-THC produced a significant elevation of steady-state levels of delta opioid receptor mRNA. This effect was not observed in cells pretreated with PTX. The selective cannabinoid receptor antagonist SR 141716A blocked the effects elicited by delta9-THC on delta opioid receptor desensitization, down-regulation and gene expression; thus indicating that these are mediated via activation of cannabinoid receptors. These data demonstrate the existence, in NG 108-15 cells, of a complex cross-talk between the cannabinoid and opioid receptors on prolonged exposure to delta9-THC triggered by changes in signaling through Gi and/or G0-coupled receptors.

The action of FeCl(3) on 3-(alkylsulfanyl)thiophenes (3-(alkylthio)thiophenes) leads to the one-step formation of regioregular alpha-conjugated oligothiophenes, from trimer to octamer, depending on the solvent used and on the length of the alkyl chain. The regiochemistry of these oligomers is characterized by one inner head-to-head linkage between adjacent rings and by a variable number of lateral head-to-tail junctions. The reaction of ferric chloride with the head-to-head and head-to-tail bis(methylsulfanyl)-2,2'-bithiophenes gives the corresponding tetramers, while the reaction with the tail-to-tail counterpart affords a high molecular weight insoluble material. With the aid of theoretical calculations, these results are interpreted on the basis of the joint effects of the orienting power of the substituents and of the stability of the radical cations formed during the oxidative process.

Hair trace element (TE) (Cr, Mn, Fe, Zn, Cu, Br, Rb, Sr, Pb) levels from 336 healthy subjects were measured by the Proton-Induced X-ray Emission (PIXE) method. The subjects were divided in three groups: 157 full-term neonates (75 male and 82 female), 86 children (41 male and 45 female) ages 6 to 11 yr, and 93 adolescents (51 male and 42 female) 11 to 16 yr old. Cu, Zn, Cr, and Br show an increase from birth to 8 yr and then decrease. Fe, Mn, and Sr strongly decrease up to 8 yr and then remain almost stable. Sex differences are present in Fe, Zn, and Br of children and in Cu, Cr, and Br of adolescents.

Follow-on formulae are recommended as part of the liquid intake of the weaning diet for infants from 6 months on and children aged 12-36 months. The amount of energy and nutrients absorbed by infants from Beikost and milk differs enormously depending on a number of factors and therefore the recommended composition of follow-on formulae varies accordingly. In the future a greater understanding of the nutritional needs of infants and the possibility of choosing between high- or low-protein content formulae may provide infants with a better balanced diet.

Concentrations of 8 trace elements (Fe, Cu, Zn, Se, Br, Pb, Rb, and Sr) at different lactation time were measured by the PIXE multi-elemental technique. Time dependence and interelement correlations were studied. A total of 200 milk samples from 32 lactating mothers were supplied from 2 to 120 d after delivery of 26 full-term and 6 preterm infants. All elements showed a lognormal frequency-distribution. The Fe, Cu, Zn, and Se contents in preterm milk were found to be somewhat different with respect to full-term milk. Cu, Zn, Se, Br, Pb, and Rb concentrations declined with lactation time, both in pre- and full-term samples. Sr and Fe contents did not show any change with time. Detailed analysis of data by partial correlation and multiple regression methods was performed. No substantial differences between preterm and full-term samples were found in the results of partial correlation analysis. Cu and Zn were found to be correlated with lactation time, whereas the measured time dependence for the other elements has to be attributed to the effect of the existing interelement correlation. All the measured elements appeared to be correlated with at least one other element. In particular, Se was inversely correlated with Zn and directly with Cu. The zinc and copper contents in milk can therefore depend on the variation in the mother selenium intake.

Human milk is believed to provide all the nutrients necessary for normal infant growth. The present study is concerned with the evaluation of longitudinal changes in Fe, Cu, Zn, Se, Br, Pb, Rb, and Sr milk contents over a long period of lactation. A total of 140 milk samples from 26 lactating mothers were supplied from the 2nd to the 180th day after delivery of a full-term healthy infant. Cu, Zn, and Se showed a time-dependent decrease, with similar 10-day half-times. Br and Pb showed correlations with time, but the data fitting produced very short (2-3 days) half-times. The Fe, Rb, and Sr contents were constant over the lactation time. After about one month of lactation, trace element contents tend to stabilise, as do other milk components.

Proton Induced X-ray Emission (PIXE) was employed to measure simultaneously the concentration of 12 trace elements in the hair of 141 AGA newborn infants at term. Log-normal distributions were measured for all elements. There were no significant differences in trace elements in relation to sex, gestational age and body weight. The geometric means (mg/kg) were: Cr, 1.5 +/- 0.2; Mn, 1.5 +/- 0.1; Fe, 51 +/- 4; Ni, 1.0 +/- 0.2; Cu, 6.1 +/- 0.3; Zn, 133 +/- 3; As, 0.055 +/- 0.005; Se 0.81 +/- 0.05; Br, 1.3 +/- 0.1; Pb, 1.4 +/- 0.2; Rb, 0.22 +/- 0.03; and Sr, 1.5 +/- 0.2. Some direct and inverse partial correlations among elements were found at different levels of significance. Each element was significantly correlated with at least one other. Zinc and copper concentrations were lower compared to data in the literature. The high values of chromium and selenium concentrations were in agreement with previous findings. The manganese level was in accordance with previous data. The Zn/Cu ratio agreed very well with the data in the literature. This indicates that while concentration values may be subjected to large variations due to living conditions, correlations could be more stable and therefore offer insight on the regulatory mechanisms governing trace element metabolism in man.

Statural growth was studied in 16 glomerulopathic children, 12 boys and 4 girls, treated with alternate-day prednisone for more than 2 years. Five patients were older than 12 years when started on therapy. Growth velocity was significantly slower in boys who received therapy during peripubertal age than in younger boys taking similar amounts of prednisone. In boys, pubertal growth spurt was delayed and shorter than normal, but growth continued with a velocity greater than normal for some years and kept on after 19 years of age. The ultimate height of the patients followed up after 19 years of age ranged within the normal limits of genetic height potential.

Anti-HBV vaccination was performed in 17 children with chronic renal insufficiency on conservative treatment and in 29 control children. The response to vaccination was satisfactory in patients as well as in the control group and no significant difference was found between the two groups as to percentage of responders and to the titre of HBsAb produced. It appears reasonable to vaccinate all patients with chronic renal insufficiency before they reach end-stage renal disease in areas with high prevalence of HBV infection.

Zinc content of serum, hair and erythrocytes, urinary zinc excretion, zinc clearance (CZn) and the ratio of CZn to creatinine clearance (CCr) (CZn/CCr) were measured in 32 children aged between 2.1 and 14.4 years suffering from idiopathic nephrotic syndrome (INS) without renal failure (CCr greater than 70 ml/min 1.73 m2 body surface area). Nineteen subjects had proteinuria and the remaining 13 were in remission. All children received calcium and vitamin D supplementation while on steroid therapy. There was high dietary zinc and protein intake. The results were compared with those obtained from 19 healthy subjects (aged 2-14 years). Zinc concentration in serum, erythrocytes and urine were measured by a colourimetric method. Proton induced X-ray emission was used to determine zinc content in hair. In patients both with and without proteinuria, the mean contents of serum, hair and erythrocytes were significantly lower than in the control group. The urinary zinc excretion, CZn and CZn/CCr in INS children were significantly higher than in the control group. A positive correlation was found between urinary zinc and protein excretion. In spite of high dietary zinc intake and normal intestinal absorption, children with INS had a zinc deficiency. This was probably caused by an increased urinary zinc loss.

Histological examination of renal biopsies in 64 Neapolitan children aged 13 months to 14 years who presented with nephrotic syndrome or persistent hematuria and/or proteinuria revealed membranous glomerulopathy (M.G.) in 14. Hepatitis B surface antigen (HBsAg) was found in the serum of 9/14 children with M.G. and in 1/14 children in an age and sex matched control group. The prevalence of HBsAg positivity in the M.G. children suggests a relationship between HBV infection and the disease. The high prevalence of males in HBsAg positive M.G. children suggests that males have an increased risk of contracting M.G. The absence of chronic liver disease in 8/9 HBsAg positive M.G. patients, and the lack of correlation between the clinical manifestations of kidney disease and the rate of HBV replication indicate that different mechanisms underlie the hepatic and renal pathologies.