[A comparative study of the treatment of vesicoureteral reflux in childhood: a review of a series of 636 refluxing units]

A number of 411 pediatric patients (636 refluxing renal units) diagnosed as having vesicoureteral reflux (VUR) were evaluated in our Hospital between 1985 and 1997. All the patients were divided in two historic groups based on the therapeutical modalities employed. The children included in group A (between 1985 and 1995) were medically or surgically treated according to the grade of reflux. In the group B (between 1995 and 1997), the endoscopic treatment was added to previous. All cases underwent urine cultures, renal ultrasonography, voiding cystourethrography and isotopic gammagraphy with DMSA scan. In some patients were performed radionuclide renography with DTPA or MAG-3 to assess renal function. We consider that medical management is required in low grade reflux (I and II) but patients with high grade reflux (IV and V) clearly benefit from early ureteral surgical reimplantation (Cohen technique). In our series, patients with reflux grade III are treated endoscopically with Teflon or PDMS (polydimethylsiloxane) with resolution of reflux in 82-92% after first injection.

Secretory phospholipase A2 induces phospholipase Cgamma-1 activation and Ca2+ mobilization in the human astrocytoma cell line 1321N1 by a mechanism independent of its catalytic activity

The effect of secretory phospholipase A2 (sPLA2) on intracellular Ca2+ signaling in human astrocytoma cells was studied. sPLA2 increased cytosolic [Ca2+] ([Ca2+]c) in both Ca2+-containing and Ca2+-free medium, thus suggesting Ca2+ release from intracellular stores. The activation by sPLA2 of arachidonate release via cytosolic PLA2 (cPLA2) was also independent of extracellular Ca2+. As sPLA2 requires Ca2+ for activity, these results indicate that both Ca2+ mobilization and cPLA2 activation induced by sPLA2 are unrelated to phospholipase activity but dependent on signaling mechanisms. The sPLA2-induced [Ca2+]c peak was sensitive to Bordetella pertussis toxin and inhibited by caffeine, suggesting its mediation by inositol 1,4,5-trisphosphate (IP3). sPLA2 induced tyrosine phosphorylation and membrane targeting of phospholipase Cgamma-1 (PLCgamma-1). Moreover, the Ca2+ peak was sensitive to protein tyrosine kinase inhibitors. sPLA2 activates two signaling pathways: one leading to the activation of the MAP kinase/cPLA2 cascade and another leading to PLCgamma activation and Ca2+ release.

Ganglioneuromatous polyposis of the colon associated with adenocarcinoma and primary hyperparathyroidism

A rare case of ganglioneuromatous polyposis of the colon found in association with mucinous adenocarcinoma and primary hyperparathyroidism caused by a parathyroid adenoma in a 77-year-old woman is described. We discuss the clinical implications of this finding and review the literature.

Yarrowia lipolytica cell wall architecture: interaction of Ywp1, a mycelial protein, with other wall components and the effect of its depletion

Linkages of Ywp1 to other components of the Yarrowia lipolytica mycelial cell wall were studied by extraction with beta-mercaptoethanol and zymolyase (a beta-glucanase complex) and by the use of rabbit polyclonal antibody preparation raised against Ywp1. Ywp1 complexed with an N-glycosylated cell wall protein(s) to form supramolecular complexes through disulphide bridges (extractable with beta-mercaptoethanol) or bonded to beta-1,3-glucan (extractable with zymolyase). The lack of a specific morphological phenotype when YWP1 was knocked out by gene disruption might indicate that other proteins present in the cell wall of Y. lipolytica compensated for its loss. In this mutant, the electrophoretic pattern of proteins, detected with polyclonal antibodies against the entire cell wall, was different from that obtained with the parental strain, but sensitivity to calcofluor white, zymolyase and chitinase did not change. Quantitative analysis of fluorescence emitted by cells in the presence of fluorescent wheat germ agglutinin (FITC-WGA) indicated that chitin was organized in the cell wall of the mutant cells in a form different from that in the parental strain.

Ca2+-induced Ca2+ release in chromaffin cells seen from inside the ER with targeted aequorin

The presence and physiological role of Ca2+-induced Ca2+ release (CICR) in nonmuscle excitable cells has been investigated only indirectly through measurements of cytosolic [Ca2+] ([Ca2+]c). Using targeted aequorin, we have directly monitored [Ca2+] changes inside the ER ([Ca2+]ER) in bovine adrenal chromaffin cells. Ca2+ entry induced by cell depolarization triggered a transient Ca2+ release from the ER that was highly dependent on [Ca2+]ER and sensitized by low concentrations of caffeine. Caffeine-induced Ca2+ release was quantal in nature due to modulation by [Ca2+]ER. Whereas caffeine released essentially all the Ca2+ from the ER, inositol 1,4, 5-trisphosphate (InsP3)- producing agonists released only 60-80%. Both InsP3 and caffeine emptied completely the ER in digitonin-permeabilized cells whereas cyclic ADP-ribose had no effect. Ryanodine induced permanent emptying of the Ca2+ stores in a use-dependent manner after activation by caffeine. Fast confocal [Ca2+]c measurements showed that the wave of [Ca2+]c induced by 100-ms depolarizing pulses in voltage-clamped cells was delayed and reduced in intensity in ryanodine-treated cells. Our results indicate that the ER of chromaffin cells behaves mostly as a single homogeneous thapsigargin-sensitive Ca2+ pool that can release Ca2+ both via InsP3 receptors or CICR.

Distribution, characterization, and growth hormone-releasing activity of pituitary adenylate cyclase-activating polypeptide in the European eel, Anguilla anguilla

The complementary DNA encoding pituitary adenylate cyclase-activating polypeptide (PACAP) has been cloned from two species of teleost fishes, the Sockeye salmon and the Thai catfish, and the amino acid sequence of PACAP has been determined in another teleost, the stargazer. However, to date, the detailed distribution of PACAP immunoreactivity has never been investigated in the fish brain. In the present study, we have determined the localization of PACAP-immunoreactive neurons in the central nervous system of a primitive teleost fish, the European eel Anguilla anguilla, using an antiserum raised against PACAP27. PACAP-positive perikarya were exclusively observed in the diencephalon, i.e. in the preoptic nucleus of the hypothalamus and in the dorsal and ventral nuclei of the thalamus. PACAP-immunoreactive fibers were detected in various areas of the brain, notably in the ventral telencephalon, the diencephalon, the mesencephalon, the cerebellar valvula, and the medulla oblongata. In addition, a dense accumulation of PACAP-containing nerve terminals was found in the pars distalis of the pituitary. The PACAP-like immunoreactivity contained in the eel brain was characterized by HPLC analysis combined with RIA quantification. The major form of PACAP-immunoreactive material coeluted with mammalian PACAP38. Molecular cloning of the PACAP precursor has previously shown that in fish, PACAP and GH-releasing hormone (GHRH) originate from the same precursor. We have thus investigated the effects of PACAP and GHRH on GH secretion from eel pituitary cells in primary culture. Dose-response experiments revealed that PACAP27 and PACAP38 possessed the same efficacy, but PACAP38 was 12 times more potent than PACAP27 in stimulating GH release (ED50 = 4.3 x 10(-10) and 3.5 x 10(-9) M, respectively). In contrast, GHRH, even at a high concentration (10(-6) M), had no effect on GH release. Taken together, these data indicate that in the eel, PACAP may play a significant role in the regulation of somatotrope cells: 1) PACAP-immunoreactive neurons are exclusively located in the diencephalon and send numerous projections in the pars distalis; and 2) PACAP, but not GHRH, dose dependently stimulates GH secretion from cultured eel pituitary cells.

Acute scrotum: an exceptional presentation of acute nonperforated appendicitis in childhood

Acute scrotum is an exceptional form of presentation of acute appendicitis in the pediatric age group. Only 14 cases have been described in literature. The authors report a case of an 8-year-old boy with a 12-hour history of right hemiscrotal pain secondary to acute retrocecal nonperforated appendicitis. Surgical exploration showed a patent "processus vaginalis."

Functional measurements of [Ca2+] in the endoplasmic reticulum using a herpes virus to deliver targeted aequorin

Changes in the free calcium concentration of the endoplasmic reticulum ([Ca2+]er) play a central role controlling cellular functions like contraction, secretion or neuronal signaling. We recently reported that recombinant aequorin targeted to the endoplasmic reticulum (ER) [Montero M., Brini M., Marsault R. et al. Monitoring dynamic changes in free Ca2+ concentration in the endoplasmic reticulum of intact cells. EMBO J 1995; 14: 5467-5475, Montero M., Barrero M.J., Alvarez J. [Ca2+] microdomains control agonist-induced Ca2+ release in intact cells. FASEB J 1997; 11: 881-886] can be used to monitor selectively [Ca2+]er in intact HeLa cells. Here we have used a herpes simplex virus type 1 (HSV-1) based system to deliver targeted aequorin into a number of different cell types including both postmitotic primary cells (anterior pituitary cells, chromaffin cells and cerebellar neurons) and cell lines (HeLa, NIH3T3, GH3 and PC12 cells). Functional studies showed that the steady state lumenal [Ca2+]er ranged from around 300 microM in granule cells to 800 microM in GH3 cells. InsP3-coupled receptor stimulation with agonists like histamine (in HeLa, NIH3T3 and chromaffin cells), UTP and bradykinin (in PC12 cells) or thyrotropin-releasing hormone (TRH, in GH3 cells) produced a very rapid decrease in lumenal [Ca2+]er. Caffeine caused a rapid Ca2+ depletion of the ER in chromaffin cells, but not in the other cell types. Depolarization by high K+ produced an immediate and reversible increase of [Ca2+]er in all the excitable cells (anterior pituitary, GH3, chromaffin cells and granule neurons). We conclude that delivery of recombinant aequorin to the ER using HSV amplicon provides the first direct quantitative and dynamic measurements of [Ca2+]er in several primary non-dividing cells.

Characterization and localization of two forms of gonadotropin-releasing hormone (GnRH) in the spinal cord of the frog Rana ridibunda

Two molecular variants of gonadotropin-releasing hormone (GnRH) have been previously characterized in the brain of amphibians, i.e., mammalian GnRH (mGnRH) and chicken GnRH-II (cGnRH-II). The aim of the present study was to identify the molecular forms of gonadotropin-releasing hormone and to localize gonadotropin-releasing hormone-containing elements in the spinal cord of the frog Rana ridibunda using highly specific antisera against mGnRH and cGnRH-II. High-performance liquid chromatography (HPLC) analysis combined with radioimmunoassay (RIA) detection revealed that frog spinal cord extracts contained both mGnRH and cGnRH-II. Immunohistochemical labeling revealed that the frog spinal cord was devoid of GnRH-containing cell bodies. In contrast, numerous GnRH-immunoreactive fibers were observed throughout the entire length of the cord. mGnRH immunoreactivity was only detected in the rostral region of the cord and consisted of varicose processes located in the vicinity of the central canal. cGnRH-II-positive fibers were found throughout the spinal cord, the density of immunoreactive processes decreasing gradually toward the caudal region. Two main cGnRH-II-positive fiber tracts with a rostrocaudal orientation were observed: a relatively dense fiber bundle surrounding the central canal, and a more diffuse plexus in the white matter. In addition, short, varicose cGnRH-II-positive processes with a radial orientation were present throughout the gray matter. These fibers were particularly abundant ventromedially and formed a diffuse network that ramified laterally to end in the vicinity of motoneurons. Taken together, these data indicate that the frog spinal cord, like the frog brain, contains two forms of GnRH. The presence of numerous cGnRH-II-immunoreactive fibers in the ventral horn suggests that cGnRH-II may influence the activity of a subpopulation of motoneurons.

Ca2+ homeostasis in the endoplasmic reticulum: coexistence of high and low [Ca2+] subcompartments in intact HeLa cells

Two recombinant aequorin isoforms with different Ca2+ affinities, specifically targeted to the endoplasmic reticulum (ER), were used in parallel to investigate free Ca2+ homeostasis in the lumen of this organelle. Here we show that, although identically and homogeneously distributed in the ER system, as revealed by both immunocytochemical and functional evidence, the two aequorins measured apparently very different concentrations of divalent cations ([Ca2+]er or [Sr2+]er). Our data demonstrate that this contradiction is due to the heterogeneity of the [Ca2+] of the aequorin-enclosing endomembrane system. Because of the characteristics of the calibration procedure used to convert aequorin luminescence into Ca2+ concentration, the [Ca2+]er values obtained at steady state tend, in fact, to reflect not the average ER values, but those of one or more subcompartments with lower [Ca2+]. These subcompartments are not generated artefactually during the experiments, as revealed by the dynamic analysis of the ER structure in living cells carried out by means of an ER-targeted green fluorescent protein. When the problem of ER heterogeneity was taken into account (and when Sr2+ was used as a Ca2+ surrogate), the bulk of the organelle was shown to accumulate free [cation2+]er up to a steady state in the millimolar range. A theoretical model, based on the existence of multiple ER subcompartments of high and low [Ca2+], that closely mimics the experimental data obtained in HeLa cells during accumulation of either Ca2+ or Sr2+, is presented. Moreover, a few other key problems concerning the ER Ca2+ homeostasis have been addressed with the following conclusions: (a) the changes induced in the ER subcompartments by receptor generation of InsP3 vary depending on their initial [Ca2+]. In the bulk of the system there is a rapid release whereas in the small subcompartments with low [Ca2+] the cation is simultaneously accumulated; (b) stimulation of Ca2+ release by receptor-generated InsP3 is inhibited when the lumenal level is below a threshold, suggesting a regulation by [cation2+]er of the InsP3 receptor activity (such a phenomenon had already been reported, however, but only in subcellular fractions analyzed in vitro); and (c) the maintenance of a relatively constant level of cytosolic [Ca2+], observed when the cells are incubated in Ca2+-free medium, depends on the continuous release of the cation from the ER, with ensuing activation in the plasma membrane of the channels thereby regulated (capacitative influx).

[Inflammatory pseudotumor of the spleen]

A case of inflammatory pseudotumor of the spleen in a 69-year-old woman who was studied for elevated globular sedimentation rate is presented. The lesion was observed on echography as a mixed solid-cystic mass. Magnetic resonance showed a slight decrease in signal intensity in potentiated T1 sequences and a heterogenic mass with high signal areas in T2 images and protonic density. Splenectomy was performed and histopathologic study demonstrated an inflammatory pseudotumor of 10 cm in its greatest size. Two year follow up was satisfactory. On review of the literature only 34 cases of inflammatory pseudotumors have been previously published. Half of the cases presented during the 6th and 7th decades of life, with women being the most frequently affected. Inflammatory pseudotumors of the spleen are benign lesions which should be considered in the differential diagnosis of splenic masses. Since diagnosis cannot be made preoperatively, and a malignant tumor is almost always suspected, splenectomy should be performed.

Dynamics of [Ca2+] in the endoplasmic reticulum and cytoplasm of intact HeLa cells. A comparative study

We have measured the [Ca2+] in the endoplasmic reticulum ([Ca2+]er) of intact HeLa cells at both 22 degrees C and 37 degrees C using endoplamsic reticulum-targeted, low Ca2+ affinity aequorin reconstituted with coelenterazine n. Aequorin consumption was much slower at 22 degrees C, and this allowed performing a much longer study of the dynamics of [Ca2+]er. The steady-state [Ca2+]er (500-600 microM) was not modified by the temperature, although both the rates of pumping and leak were decreased at 22 degrees C. The behavior of both [Ca2+]er and cytoplasmic [Ca2+] ([Ca2+]c) after the addition of increasing concentrations of agonists and/or Ca2+-ATPase inhibitors, or following incubation in Ca2+-free medium were compared. We show that agonists induce a fast but relatively small decrease in [Ca2+]er, which is enough to produce a sharp increase in [Ca2+]c. Termination of Ca2+ release is controlled by feedback inhibition of the inositol 1,4,5-trisphosphate receptors by [Ca2+]c, a mechanism that appears to be designed to release the minimum amount of Ca2+ necessary to produced the required [Ca2+]c signal. We also show that Ca2+ release is inhibited progressively when [Ca2+]er decreases below a threshold of about 150 microM, even in the absence of Ca2+ pumping or -Ca2+-c increase. This effect is consistent with a regulation of the inositol 1,4,5-trisphosphate-gated channels by [Ca2+]er.

[Use of Tc 99m DTPA in the follow-up of 2 pediatric patients diagnosed with megacalycosis or Puigvert's disease]

OBJECTIVE

Megacalycosis or Puigvert's disease is a congenital anomaly of renal development characterized by caliceal dilatation, an increased number of calyces, associated with hypoplasia of the pyramids of Malpighi, and a normal renal pelvis. Renal function is always normal and there is no evidence of obstruction to urinary flow. The foregoing are important in distinguishing megacalycosis from congenital hydronephrosis. We have studied two pediatric patients with this renal anomaly by means of non invasive techniques, in order to demonstrate they had no urinary flow obstruction despite the caliceal dilatation.

METHODS

Two cases of megacalycosis that had been diagnosed at our hospital from 1991 to 1995 are described and the literature is reviewed. Diagnosis was basically by intravenous urography. A diuretic renogram with technetium 99m diethylenetriaminepentaacetic acid (Tc 99m DTPA) showed no urinary flow obstruction in the anomalous kidney. This test was repeated several times, together with renal function studies like the technetium 99m dimercaptosuccinic acid scan (DMSA Scan).

RESULTS

Both patients are asymptomatic and have a normally functioning kidney with no scars demonstrable on the DMSA scan. Renal urinary flow studies have remained within the normal ranges (elimination of more than 40% of the radionuclide 20 min after the administration of furosemide). US control evaluations have shown adequate renal growth and persistent caliceal dilatation in both cases.

CONCLUSIONS

This congenital malformation must be considered when investigating renal dilatation, since megacalycosis does not require surgical treatment. Intravenous urography is useful in the diagnosis of this condition and Tc 99m DPTA is the best test for subsequent control evaluations.

[Ca2+] microdomains control agonist-induced Ca2+ release in intact HeLa cells

We have monitored specifically the [Ca2+] in the lumen of the endoplasmic reticulum (ER) of intact HeLa cells using an ER-targeted low-Ca2+-affinity aequorin. The steady-state [Ca2+] in the ER was around 600 microM. Histamine induced a concentration-dependent decrease in lumenal [Ca2+], whose rate increased near one order of magnitude and became "quantal" when cytosolic [Ca2+] ([Ca2+]c) was clamped with the Ca2+ chelator BAPTA. This effect was not due to decreased Ca2+ pumping because simultaneous addition of a SERCA inhibitor produced only additive effects. Given that inhibition by [Ca2+]c of the inositol 1,4,5-trisphosphate-gated channels requires a [Ca2+]c much higher than that observed in the bulk cytosol after histamine addition, we conclude that local [Ca2+]c microdomains at the site of release strongly inhibit agonist-induced Ca2+ mobilization in intact cells. This effect should play a key role in the mechanism controlling cytosolic [Ca2+] oscillations and waves, and therefore in the generation of spatio-temporal Ca2+ patterns.

Intravitreal ganciclovir treatment in progressive outer retinal necrosis

PURPOSE

To report two patients with progressive outer retinal necrosis, which is presumed to be caused by the varicella-zoster virus in patients with acquired immunodeficiency syndrome (AIDS).

METHOD

Case report.

RESULTS

The patients were treated with intravenous foscarnet, 60 mg per kg of body weight three times per week, without response. Remission of retinal necrosis occurred with the commencement of intravitreal ganciclovir treatment, 400 mg two times per week. Laser photocoagulation was performed in both cases. Neither patient developed retinal detachment.

CONCLUSIONS

Intravitreal ganciclovir treatment combined with systemic antiviral agent therapy in patients with progressive outer retinal necrosis may delay progress of the disease. Early photocoagulation may prevent the development of retinal detachment if retinal necrosis is controlled.

Broadly reactive antibodies against a gp120 V3 loop multi-epitope polypeptide neutralize different isolates of human immunodeficiency virus type 1 (HIV-1)

A gene encoding for a novel multi-epitope polypeptide (TAB4) was synthesized and expressed in Escherichia coli. The protein was composed of 15 amino acid fragments derived from the V3 loop of HIV-1 isolates MN, IIIB, RF, JY1, BRVA and LR150, joined by five-amino-acid linkers. Immunogenicity of TAB4 in rabbits was studied, and the antibody response against individual peptides investigated. TAB4 was shown to be immunogenic in Complete Freund's Adjuvant in a dose-dependent manner, and was able to elicit a humoral response against all V3 epitopes included on the protein. Sera from some of the animals were able to neutralize the replication of viral strain MN, and in one case IIIB, with moderate titers. Some sera also neutralized several Cuban clinical strains, isolated in peripheral blood mononuclear cells, after one round of amplification in MT4 cells.

A monolayer coagglutination microplate technique for typing red blood cells

BACKGROUND AND OBJECTIVES

Serologic agglutination tests have the disadvantage of lack of an objective endpoint that can be easily read and quantitated. We have developed a new method for ABO and Rh typing based on producing a red blood cell (RBC) monolayer on microplates and the mixed hemagglutination reaction.

MATERIALS AND METHODS

We have employed a new red cell fixation buffer to prepare the RBC monolayer. As the technique for grouping, we used a mixed agglutination reaction between the RBC monolayer and the RBCs to be typed.

RESULTS

Compared with an automated hemagglutination system in 34,519 samples, the method is shown to be more sensitive, free of false positive reactions, and cost-effective.

CONCLUSIONS

The microplate coagglutination method is accurate and lower in cost than conventional methods.

[Benign gingival granular cell tumor in the newborn: congenital epulis]

Gingival granular cell tumor, or congenital epulis, was first described by Neumman in 1871 and subsequently 201 cases have been published in 173 patients. It is an uncommon benign tumor that is present like a pedunculated, smooth surfaced, isolated lesion on the alveolar mucosa of the maxillar of the newborn child. Its firm consistency and variable size can occasionally cause problems in the child's breathing or feeding. This tumor is easily diagnosed clinically and, although spontaneous regression of the tumor mass has occasionally been reported, the current treatment is surgical removal. Two new cases of congenital epulis are reported and a literature review is included.

Primary cultures of dispersed pituitary cells from estradiol-pretreated female silver eels (Anguilla anguilla L.): immunocytochemical characterization of gonadotropic cells and stimulation of gonadotropin release

To analyze the multihormonal control mechanisms of GTH secretion in the eel, primary culture of pituitary cells from control or estradiol-treated female silver eels, a treatment known to stimulate in vivo GTH synthesis, was developed. Dispersed eel pituitary cells obtained by enzymatic (trypsin/DNAse) and mechanical dispersion were cultured in Earles M199, at 18 degrees. Immunoreactive GTH (ir-GTH) cells were characterized by the immunoperoxidase method, using antiserum to carp GTH beta subunit. Ir-GTH cells from control silver eels were small and represented 14% of the dispersed pituitary cells. In contrast, ir-GTH cells from estradiol-treated eels were larger (cell area x 2.5) and represented a higher proportion (21%) of the pituitary cells. Intracellular and medium contents of GTH were measured by radioimmunoassay for the GTH beta subunit. In vivo estradiol-treatment increased more than 100-fold the GTH content of cell cultures. GTH release, studied over 1 to 4 hr, was undetectable in cultures from normal eels. In contrast, GTH release was low (less than 2% of cell content) but measurable in cultures from estradiol-treated eels. Subsequent experiments examined effects of various secretagogues on GTH release from primary cultures of pituitary cells from estradiol-pretreated eels. GTH release was significantly increased (x1.5 to x3 basal release) by 10(-6) M GnRH-A as well as by both native GnRHs in the eel (mammalian GnRH, mGnRH, and chicken GnRH-II, cGnRH-II), at the same concentration. Lower GnRH concentrations had no significant effect, indicating a low sensitivity of gonadotrophs to GnRH, likely to be related to their immature state at the silver stage. The similar efficacy of mGnRH and cGnRH-II suggested that the pituitary GnRH receptor had a low specificity toward various molecular forms, in the eel as in the other nonmammalian species. The protein kinase C (PKC) activator (phorbol ester: PMA) also stimulated GTH secretion, with a maximal effect at 10(-8) M, indicating that the PKC pathway was functional. In contrast, a depolarizing agent (50 mM KCl) had no significant effect on GTH release, suggesting lack of a functional voltagesensitive calcium channel (VSCC) secretory pathway. Perifusion experiments on whole pituitary confirmed the lack of effect of KCl on gonadotrophs from E2-pretreated eels and indicated that an additional in vivo treatment with GnRH agonist and dopamine antagonist could induce the differentiation of a functional VSCC pathway. These characteristics of the transduction mechanisms may be related to the immature state of the eel gonadotrophs at the silver stage.