The renal nerves in the newborn rat

Immunocytochemical methods were used to investigate the distribution of afferent [calcitonin gene-related peptide-(CGRP) immunoreactive and substance P-immunoreactive] nerves and efferent (neuropeptide Y-immunoreactive and dopamine -hydroxylase-immunoreactive) nerves in the kidneys of rats within the 1st day of life. The newborn rat kidney possesses an afferent and efferent innervation. Both afferent and efferent nerves reach the kidney in the same bundles. The afferent sensory fibers predominate overwhelmingly in the renal pelvis and ureter while the efferent fibers clearly predominate in the vasculature. The corticomedullary connective tissue contains both types of innervation with a more prominent afferent innervation (CGRP immunoreactive). Only afferent arterioles of perihilar nephrons were innervated by efferent sympathetic fibers. The distribution and extent of afferent and efferent innervation is consistent with the renal nerves playing a significant role in the transition from fetal to newborn life. The close proximity between afferent and efferent fibers suggests a possible interaction between the two systems.     

Non-traumatic brain abscess

Between 1953 and 1989 eighty cases of non-traumatic brain abscess were treated in our department. We have re-examined the clinical and neuroradiological features of this pathological process and present our therapeutic approach and results. We believe that the optimal treatment for brain abscess consists of surgical removal.The prognosis for these lesions has undergone a marked improvement over the last two decades in response to neuroradiological, microbiological and surgical advances. The most influential prognostic factor seems to be preoperative clinical status.     

Negative modulation of nitric oxide production by neurotensin as a putative mechanism of the diuretic action of SR 48692 in rats

1. We investigated the effect of the non-peptide neurotensin (NT) antagonist SR 48692 on renal function in rats and the involvement of nitric oxide (NO) in the diuretic action of this compound.
2. In fed animals, SR 48692 dose-dependently (0.5 to 12.5 mg kg⁻¹, p.o., 0.03 to 1 mg kg⁻¹, i.p. and 0.1 to 1 μg/rat, i.c.v.) increased urine output and urinary excretion of Na⁺, K⁺ and Cl⁻ and reduced urine osmolality. The diuretic activity was also evident in water-deprived, fasted animals and in fasted, water-loaded rats.
3. NT (0.1 μg/rat, i.c.v.) had no effect on urine output in fed rats, but reduced the diuretic action of SR 48692 (1 μg/rat, i.c.v.). The opposite result was obtained in fasted, water-loaded animals: NT dose-dependently (0.01 and 0.1 μg/rat, i.c.v.) inhibited diuresis and this effect was significantly inhibited by i.c.v. SR 48692. In this experimental condition, SR 48692 did not further increase the on-going diuresis.
4. The NO synthesis inhibitor N^ω-nitro-L-arginine methyl ester (L-NAME; 30 mg kg⁻¹, i.p.) alone had no effect on urine output in fed rats but prevented the diuretic action of i.c.v. or i.p. SR 48692; L-arginine (1 g kg⁻¹, i.p.) but not D-arginine (1 g kg⁻¹, i.p.) restored the SR 48692-dependent increase in diuresis. L-NAME had no effect on furosemide-stimulated diuresis.
5. Systemically administered L-NAME or i.c.v. NT in fasted, water-loaded rats significantly reduced water diuresis but this effect was no longer seen in animals given i.p. L-arginine. Rats receiving i.c.v. NT, whose diuresis was significantly reduced, also excreted less nitrates and nitrites in urine.
6. Increased diuresis after central or systemic administration of SR 48692 to fed rats was paralleled by increased urinary excretion of nitrates and nitrites, this being consistent with peripheral enhancement of NO production after NT-receptor blockade by SR 48692. The increase in diuresis after furosemide also involved an increase of nitrates and nitrites in urine, but this effect was about half that attained with an equipotent diuretic dose of SR 48692.
7. In fed rats, the NO donor isosorbide-dinitrate, reduced systolic blood pressure (unlike SR 48692 which did not affect blood pressure) but also dose-dependently (1 and 5 mg kg⁻¹, i.p.) stimulated urine output.
8. The overall effects of SR 48692 strongly support a link between the actions of endogenous NT, AVP and peripheral NO production in the modulation of renal excretion of water, Na⁺, K⁺ and Cl⁻.

     

Percutaneous transluminal renal angioplasty in patients with solitary kidney

We report our experience with percutaneous transluminal angioplasty of renal arteries (PTRA) in solitary kidney patients. Our series includes 31 patients (mean age: 52 years). 7 with solitary kidney following surgical nephrectomy and 24 with functioning solitary kidney. PTR indicated in presence of stenoses ranging from 60–95 % of vessel lumen. Procedure, with 29 patients were technically successful and mean values for stenosis dropped from 77 % to 33 %. In order to assess the results technically, changes in arterial blood pressure (according to Martin's classification) and creatinine levels were considered. Of 25 followed-up patients, 13 were cured (52%), 8 improved (32%),and 4 were unchanged (16%%). Complications were observed during procedures in five patients (16. 1 % ), superimposing that of nonsolitary kidney patients. Good revasculariiation, reduction of blood pressure, preservation or even improvement of renal function and low complications, make PTRA the best procedure with solitary kidney patients.     

Crossed aphasia. An update

The aim of this article is to present an update of a rare but interesting problem: crossed aphasia. This term indicates the presence of aphasia after unilateral cerebral lesion of the hemisphere ipsilateral to the patient's dominant hand. We report two cases, review the most relevant literature, and analyze clinical, neuroanatomical, and neurophysiological aspects, taking in consideration the various interpretations proposed to explain this unusual language disorder.     

Postnatal development of vascular β-adrenoceptor-mediated responses and the increase in the adrenaline content of the adrenal gland have a parallel time course

The present study was undertaken to analyse the relationship between postnatal development of vascular ₂-adrenoceptor-mediated responses and the content of adrenaline in the adrenal gland and its concentration in plasma. Dog saphenous vein tissue from newborn, two-weeks old and adult animals were either preloaded with ³H-noradrenaline (or ³H-adrenaline) to study prejunctional -adrenoceptor-mediated effects or mounted in organ baths to determine isoprenaline-induced relaxation of preparations contracted by phenylephrine to about 65010 of the maximum. The adrenal glands and samples of blood from the same animals were taken for estimation of adrenaline and noradrenaline.At birth, there were no -adrenoceptor-mediated effects pre- or postjunctionally. At two weeks, while the results at the prejunctional level were not significantly different from those obtained in newborns, at the postjunctional level there was a relaxant response to isoprenaline, which antagonised about 35010 of the previous contraction to 1.75 mol·l^–1 phenylephrine. In adults, isoprenaline (50 nmol·l^–1) increased by 24% tritium overflow evoked by electrical stimulation of tissues preloaded with ³H-noradrenaline but not that of tissues preloaded with ³H-adrenaline. On the other hand, propranolol (1 mol·l^–1) reduced by 21% the overflow of tritium evoked by electrical stimulation of tissues preloaded with ³H-adrenaline but not that of tissues preloaded with ³H-noradrenaline; postjunctionally, the maximal response to isoprenaline antagonised 70% of the previous contraction to 1.75 mol·l^–1 phenylephrine.At birth the catecholamine content of the adrenals was relatively low (2.9 ol·g^–1) and the adrenaline/noradrenaline ratio was 0.26; two weeks later, the catecholamine content was 14.5 mol·g-1and the adrenaline/noradrenaline ratio was 0.74; in adults, the catecholamine content was 24.5 mol·g^–1 and the adrenaline/noradrenaline ratio was 2.3. In plasma, the highest concentration of adrenaline was observed at birth (11.8 nmol·l^–1); two weeks later it was 5.5 nmol·l^–1 and in adulthood it fell to 3.1 nmol·l^–1.On the basis of these results, it is concluded that some link between the postnatal increase in adrenaline adrenal content and the development of ₂-adrenoceptor-mediated pre- and postjunctional effects may exist. Additionally it is suggested that circulating adrenaline may trigger the development of ₂-adrenoceptor-mediated responses as well as some hypertensive states occurring as a consequence of an overreactivity of the sympathoadrenal system. Correspondence to: S. Guimarães at the above address     

Management of a case of maple syrup urine disease--the use of gluco-insulinotherapy

We report here the treatment and poor outcome of a case of Maple Syrup Urine Disease with late diagnosis and retrieval (2 and 5 months, respectively). As the proband had quite high levels of plasmatic leucine (1956 micromol/L for a normal upper limit of 77), we started immediately with a gluco-insulin therapy to produce anabolism in the infant. When leucine has fallen to 275.3 micromol/L, we instituted feeding with branched chain amino acid-free protein and high energy from carbohydrates. After reviewing briefly the clinical, biochemical and therapeutic aspects of this disorder, we comment on the great difficulties of making early diagnosis and of obtaining the specific dietetic formulas to Maple Syrup Urine Disease, in Brazil.     

Psychosocial and sexual aspects of pregnant adolescents at Belém-Pará

Pregnancy is a major factor that modifies psychosocial aspects of the adolescents. A study with 120 pregnant adolescents aged 12 to 18 years, without regarding gestational age, was carried out at Prenatal Risk Program in the Secretaria Estadual de Saúde, Belém-Pará, from 10/1991 to 04/1992. At the first encounter, it was made an approach of psychosocial and sexual subjects, with the following results: onset of menarche primarily between 12-13 years old (median 12.2 years old); beginning of sexual practice at 14 years old in 50.9% of the adolescents. 56.6% were pregnant at 16 years old. Most of the adolescents (98.4%) first had sexual intercourse with their boy friends and by their own wish (72.5%). In one year of loving affair, 67.5% of the adolescents have already begun sexual activities, this attitude more prevalent among the younger(79.4%). Adolescents had learned about sexuality mainly from mates (65.1%). Although 55.9% of the adolescents were aware of some contraceptive method, just 13.3% of them used one. The majority of the pregnant adolescents (96.7%) were financially supported by their families. Respectively, 30.3% and 32.1% of these girls left school before or during pregnancy. The risk factors that may contribute to an early and unintended pregnancy among adolescents, specially the younger ones, were pointed out: little information about sex and contraceptive methods, limited practice on their use and a high rate of precocious sexual activities.     

Haemophilus influenzae type b infections and its prevention by vaccines

Haemophilus influenzae type b (Hib) infections and its prevention by vaccines are reviewed. Its prevalence is underestimated, due to technical pitfalls in the laboratory and to the difficulties of diagnosing respiratory infections, chiefly pneumonia. Taking into account all infections (respiratory, meningitis and others), Hib is probably the most important pathogen, compared to S. pneumoniae and N. meningitidis. The incidence of Hib meningitis in Brazil is presented and risk factors are discussed, as well as the preventive alternatives. The different Hib vaccines are analyzed and schedules of immunization with two of them (PRP-T and HbOC) are presented. Possible eradication of Hib diseases is discussed.