Cystatin C and renal function in pediatric kidney transplant recipients

In clinical practice, the glomerular filtration rate (GFR) is often determined with serum creatinine. However, studies have shown cystatin C to be a better parameter for the diagnosis of impaired renal function. We compared GFR estimated by plasma cystatin C with GFR estimated by serum creatinine in a sample of 50 pediatric renal transplant recipients and 24 healthy children. The correlation between GFR estimated by serum creatinine and by cystatin C was significant (r = 0.75; P < 0.001, Person’s correlation); however, in pediatric kidney transplant recipients, the GFR was 6.7 mL/min lower when determined using cystatin C rather than serum creatinine. Moreover, using GFR estimated by cystatin C we found that 42% of the pediatric kidney transplant recipients had an estimated GFR <60 mL·min-1·1.73 (m²)-1, whereas when GFR was estimated by the serum creatinine formula only 16% of the children had values below this cutoff point indicative of chronic kidney disease (P < 0.001). We conclude that, in pediatric kidney transplant recipients, estimation of GFR yields lower values when cystatin C is used rather than serum creatinine.

Sequence analysis of the 5′ third of glycoprotein C gene of South American bovine herpesviruses 1 and 5

Bovine herpesviruses 1 (BoHV-1) and 5 (BoHV-5) share high genetic and antigenic similarities, but exhibit marked differences in tissue tropism and neurovirulence. The amino-terminal region of glycoprotein C (gC), which is markedly different in each of the viruses, is involved in virus binding to cellular receptors and in interactions with the immune system. This study investigated the genetic and antigenic differences of the 5′ region of the gC (5′ gC) gene (amino-terminal) of South American BoHV-1 (n=19) and BoHV-5 (n=25) isolates. Sequence alignments of 374 nucleotides (104 amino acids) revealed mean similarity levels of 97.3 and 94.2% among BoHV-1 gC (gC1), respectively, 96.8 and 95.6% among BoHV-5 gC (gC5), and 62 and 53.3% between gC1 and gC5. Differences included the absence of 40 amino acid residues (27 encompassing predicted linear epitopes) scattered throughout 5′ gC1 compared to 5′ gC5. Virus neutralizing assays testing BoHV-1 and BoHV-5 antisera against each isolate revealed a high degree of cross-neutralization between the viruses, yet some isolates were neutralized at very low titers by heterologous sera, and a few BoHV-5 isolates reacted weakly with either sera. The virus neutralization differences observed within the same viral species, and more pronounced between BoHV-1 and BoHV-5, likely reflect sequence differences in neutralizing epitopes. These results demonstrate that the 5′ gC region is well conserved within each viral species but is divergent between BoHV-1 and BoHV-5, likely contributing to their biological and antigenic differences.

Febre amarela. I - Aspectos cíclicos e epidemiológicos

Relata-se um resumo epidemiológico do surto epizoótico de febre amarela ocorrido no ano de 1973. São postas em evidência a sua incidência, a distribuição por idades, a distribuição por sexo e a distribuição geográfica. Em seguida, são apresentados os resultados obtidos pela revisão dos casos de febre amarela, que vêm sendo estudados, recolhidos e arquivados na Coleção do Serviço de Viscerotomia da Seção de Histopatologia da Febre Amarela do Instituto Oswaldo Cruz, desde 1931. O trabalho está documentado com tabelas e gráficos que registram os dados acima indicados. Os autores ressaltam os seguintes pontos: 1) A Febre amarela, urbana e silvestre, apresenta quadros epidemiológicos inteiramente diferentes; 2) A incidência da febre amarela silvestre ocorre principalmente no sexo masculino, de acordo com os dados estatisticamente significativos; 3) A idade mais atingida pela forma silvestre é a entre 20 e 30 anos; 4) A febre amarela silvestre continua em áreas enzoóticas, ao longo dos cursos d'água; 5) Parece existir uma relação entre as condições climáticas e a incidência da febre amarela; 6) Os surtos de febre amarela ocorrem aproximadamente de 7 em 7 anos; 7) É do máximo valor o programa de vacinação e o serviço de viscerotomia da SUCAM.

Febre amarela ll - Estudo histopatológico do fígado

Ao curso de um surto epizoótico de febre amarela acontecido no ano de 1973 nas regiões norte e centro-oeste do Brasil, foram feitos exames histopatológicos de material de fígado de casos suspeitos, retirados por viscerotomia e necropsias. Foram diagnosticados 57 casos positivos. Os exames histopatológicos demonstraram que não existe diferença da doença entre os casos da África e da América do Sul. O diagnóstico histopatológico continua baseado no fígado, na lesão de Councilman, na hiperplasia e hipertrofia das células de Kupfer, nas inclusões nucleares de Magarino Torres, no sinal de Eudoro Villela nos casos de longa duração. Não houve diferença histológica entre os casos descritos nas epidemias de F.A. urbana e os surtos epidêmicos e enzoóticos de F.A. silvestre nos últimos 43 anos.

Vancomycin monitoring in term newborns: comparison of peak and trough serum concentrations determined by high performance liquid chromatography and fluorescence polarization immunoassay

INTRODUCTION: Peak and trough serum concentrations of vancomycin were determined in term newborn infants with confirmed or suspected Staphylococcus sp sepsis by high performance liquid chromatography and flourescence polarization immunoassay. OBJECTIVE: To statistically compare the results of the high performance liquid chromatography and flourescence polarization immunoassay techniques for measuring serum vancomycin concentrations. METHODS: Eighteen peak and 20 trough serum samples were assayed for vancomycin concentrations using high performance liquid chromatography and flourescence polarization immunoassay from October 1995 to October 1997. RESULTS: The linear correlation coefficients for high performance liquid chromatography and flourescence polarization immunoassay were 0.27 (peak, P = 0.110) and 0.26 (trough, P = 0.1045) respectively, which were not statistically significant. CONCLUSION: There was wide variation in serum vancomycin concentrations determined by high performance liquid chromatography as compared with those determined by flourescence polarization immunoassay. There was no recognizable pattern in the variability; in an apparently random fashion, the high performance liquid chromatography measurement was sometimes substantially higher than the flourescence polarization immunoassay measurement, and at other times it was substantially lower.

Exigências térmicas de Aedes (Stegomyia) albopictus Skuse, 1894 (Diptera, Culicidae) em condições de laboratório

Thermal requirements of Aedes (Stegomyia) albopictus Skuse, 1894 (Diptera, Culicidae) under laboratory conditions. Allochtonous species of Ae. albopictus in the American continent can be found in fourteen Brazilian states - about fifteen years had been elapsed since the first report of the presence of this species in Brazilian territory. Considering its potential epidemiological importance and its adaptation to several habitats, it was determined, for this species, the threshold temperature and the thermal constant for egg, larval and pupal stages under laboratory conditions under four constant temperatures and 12:12 hours light-dark photoperiod. The threshold temperature for the egg phase and for the first instar were quite similar: 9.07 ºC (K=214.46 degree days) and 9.23 ºC (K= 36.64 degree days), respectively. For 2nd, 3rd and 4th instar, the basal-temperature was higher, oscilating between 12.26 ºC and 13.95 ºC. The threshold temperature for the complete larval stage and for the pupal stage were 12.03 ºC (K= 99.48 degree days) and 11.87 ºC (K=32.40 degree days) for males and 11.95 ºC (K=110.11 degree days) and 11.60 ºC (K=35.30 degree days) for females, respectively.

Influência do relevo e erosão na variabilidade espacial de um Latossolo em Jaboticabal (SP)

Com o objetivo de avaliar as relações entre formas de paisagem e erosão em um Latossolo Vermelho eutroférrico (LVef) por meio de técnicas geoestatísticas na Fazenda Santa Isabel, município de Jaboticabal (SP), identificaram-se modelos de paisagem côncavo e linear. Coletaram-se amostras de solo em ambas as formas de paisagem em uma malha regular espaçada de 50 x 50 m em sete transeções na profundidade de 0,00-0,20 m, totalizando 412 pontos em 93 ha. Determinou-se a erodibilidade dos solos pelo método indireto, granulometria, bem como o carbono orgânico para cada ponto da malha, sendo esses valores usados na estimativa do potencial natural de erosão (pne). Os dados obtidos das propriedades de solo, erodibilidade e potencial natural de erosão foram analisados por meio de estatística descritiva e geoestatística com a modelagem de semivariogramas, sendo este utilizado para a confecção de mapas de krigagem. Segundo os resultados, as propriedades do solo e do pne apresentaram maior variabilidade espacial na pedoforma côncava, apesar de esta forma de paisagem apresentar menores perdas de solo por erosão e menor variabilidade espacial da erodibilidade. Deste modo, conclui-se que a erosão não adicionou variabilidade espacial para as propriedades do solo na mesma magnitude do relevo.

BIOMATERIAIS: TIPOS, APLICAÇÕES E MERCADO

AbstractThe types of compounds used in the production of biomaterials, namely metals, ceramics, synthetic and natural polymers, as well as composite materials, are discussed in the present work, together with details of their application and evolution from biocompatible to bioactive, biodegradable, and biomimetic clinical products. The chemical structure, the three-dimensional structure, and the molecular organization of compounds frequently used in the manufacture of relevant classes of biomaterials are discussed, along with their advantages and some of their major limitations in specific clinical applications. The main chemical, physical, mechanical, and biological requirements of biomaterials categories are presented, as well as typical tissular responses to implanted biomaterials. Reasons for the recent economic growth of the biomaterials market segment are addressed, and the most successful biomaterial categories are discussed, emphasizing areas such as orthopedic and cardiovascular implants, regenerative medicine, tissue engineering, and controlled drug release devices. Finally, the need for the development of innovative and more accessible biomaterials, due to the expected increase in the number of elderly people and the growing trend of personalized medical procedures, is pointed out.

Effect of lead acetate on neurobehavioral development of rats

We investigated the effects of lead exposure during the pre- and postnatal period on the neurobehavioral development of female Wistar rats (70-75 days of age, 120-150 g) using a protocol of lead intoxication that does not affect weight gain. Wistar rats were submitted to lead acetate intoxication by giving their dams 1.0 mM lead acetate. Control dams received deionized water. Growth and neuromotor development were assessed by monitoring daily the following parameters in 20 litters: body weight, ear unfolding, incisor eruption, eye opening, righting, palmar grasp, negative geotaxis, cliff avoidance and startle reflex. Spontaneous alternation was assessed on postnatal day 17 using a T maze. The animals' ability to equilibrate on a beaker rim was measured on postnatal day 19. Lead intoxication was confirmed by measuring renal, hepatic and cerebral lead concentration in dams and litters. Lead treatment hastened the day of appearance of the following parameters: eye opening (control: 13.5 ± 0.6, N = 88; lead: 12.9 ± 0.6, N = 72; P<0.05), startle reflex (control: 13.0 ± 0.8, N = 88; lead: 12.0 ± 0.7, N = 72; P<0.05) and negative geotaxis. On the other hand, spontaneous alternation performance was hindered in lead-exposed animals (control: 37.6 ± 19.7; lead: 57.5 ± 28.3% of alternating animals; P<0.05). These results suggest that lead exposure without concomitant undernutrition alters rat development, affecting specific subsets of motor skills.

Effect of fatty acids on leukocyte function

Fatty acids have various effects on immune and inflammatory responses, acting as intracellular and intercellular mediators. Polyunsaturated fatty acids (PUFAs) of the omega-3 family have overall suppressive effects, inhibiting lymphocyte proliferation, antibody and cytokine production, adhesion molecule expression, natural killer cell activity and triggering cell death. The omega-6 PUFAs have both inhibitory and stimulatory effects. The most studied of these is arachidonic acid that can be oxidized to eicosanoids, such as prostaglandins, leukotrienes and thromboxanes, all of which are potent mediators of inflammation. Nevertheless, it has been found that many of the effects of PUFA on immune and inflammatory responses are not dependent on eicosanoid generation. Fatty acids have also been found to modulate phagocytosis, reactive oxygen species production, cytokine production and leukocyte migration, also interfering with antigen presentation by macrophages. The importance of fatty acids in immune function has been corroborated by many clinical trials in which patients show improvement when submitted to fatty acid supplementation. Several mechanisms have been proposed to explain fatty acid modulation of immune response, such as changes in membrane fluidity and signal transduction pathways, regulation of gene transcription, protein acylation, and calcium release. In this review, evidence is presented to support the proposition that changes in cell metabolism also play an important role in the effect of fatty acids on leukocyte functioning, as fatty acids regulate glucose and glutamine metabolism and mitochondrial depolarization.

Regulation of antioxidant enzyme activities in male and female rat macrophages by sex steroids

Human and animal immune functions present sex dimorphism that seems to be mainly regulated by sex hormones. In the present study, the activities of the antioxidant enzymes total superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were measured in intraperitoneal resident macrophages from adult male and female rats. In addition to comparing males and females, we also examined the regulation of these enzyme activities in macrophages by sex steroids. GSH-Px activity did not differ between male and female macrophages. However, both total SOD and CAT activities were markedly higher in females than in males (83 and 180%). Removal of the gonads in both males and females (comparison between castrated groups) increased the difference in SOD activity from 83 to 138% and reduced the difference in CAT activity from 180 to 86%. Castration and testosterone administration did not significantly modify the activities of the antioxidant enzymes in male macrophages. Ovariectomy did not affect SOD or GSH-Px activity but markedly reduced (48%) CAT activity. This latter change was fully reversed by estrogen administration, whereas progesterone had a smaller effect. These results led us to conclude that differences in the SOD and CAT activities may partially explain some of the differences in immune function reported for males and females. Also, estrogen is a potent regulator of CAT in macrophages and therefore this enzyme activity in macrophages may vary considerably during the menstrual cycle.

Effect of L-arginine, dimercaptosuccinic acid (DMSA) and the association of L-arginine and DMSA on tissue lead mobilization and blood pressure level in plumbism

Lead (Pb)-induced hypertension is characterized by an increase in reactive oxygen species (ROS) and a decrease in nitric oxide (NO). In the present study we evaluated the effect of L-arginine (NO precursor), dimercaptosuccinic acid (DMSA, a chelating agent and ROS scavenger), and the association of L-arginine/DMSA on tissue Pb mobilization and blood pressure levels in plumbism. Tissue Pb levels and blood pressure evolution were evaluated in rats exposed to: 1) Pb (750 ppm, in drinking water, for 70 days), 2) Pb plus water for 30 more days, 3) Pb plus DMSA (50 mg kg-1 day-1, po), L-arginine (0.6%, in drinking water), and the combination of L-arginine/DMSA for 30 more days, and 4) their respective matching controls. Pb exposure increased Pb levels in the blood, liver, femur, kidney and aorta. Pb levels in tissues decreased after cessation of Pb administration, except in the aorta. These levels did not reach those observed in nonintoxicated rats. All treatments mobilized Pb from the kidney, femur and liver. Pb mobilization from the aorta was only effective with the L-arginine/DMSA treatment. Blood Pb concentrations in Pb-treated groups were not different from those of the Pb/water group. Pb increased blood pressure starting from the 5th week. L-arginine and DMSA treatments (4th week) and the combination of L-arginine/DMSA (3rd and 4th weeks) decreased blood pressure levels of intoxicated rats. These levels did not reach those of nonintoxicated rats. Treatment with L-arginine/DMSA was more effective than the isolated treatments in mobilizing Pb from tissues and in reducing the blood pressure of intoxicated rats.

Cholesterol changes the fatty acid composition of rat enterocytes

The effect of free cholesterol on the fatty acid composition and growth of rat fetal enterocytes was investigated in the absence and presence of 10% (v/v) fetal calf serum. Cholesterol caused a significant reduction of cell number after 6 and 12 h in culture. The fatty acid composition of enterocytes cultured in the presence of serum was also changed by the presence of 20 µM cholesterol. The fatty acid profile was determined by HPLC using fluorescence detection (325 nm excitation and 395 nm emission). Cholesterol (20 µM) increased the proportion (given in percentage of the total fatty acids) of the following fatty acids in cultured cells: lauric (by 42%), oleic (by 34%), linoleic (by 44%) and gamma-linolenic (by 20%) acids and reduced the proportion of palmitic (by 12%), stearic (by 20%), arachidonic (by 21%) and docosahexaenoic (by 44%) acids. In addition to modifying the content of individual fatty acids, cholesterol increased the polyunsaturated/saturated fatty acid ratio from 0.48 to 0.67 and the unsaturation index from 67.12 to 75.30. This is the first evidence that cholesterol modifies fatty acid composition possibly via de novo fatty acid synthesis and desaturation.

Effect of bullfrog (Rana catesbeiana) oil administered by gavage on the fatty acid composition and oxidative stress of mouse liver

The aim of the present study was to investigate the effects of daily intragastric administration of bullfrog oil (oleic, linoleic and palmitoleic acid-rich oil), corresponding to 0.4% of body weight for four weeks, on fatty acid composition and oxidative stress (lipid peroxidation and catalase activity) in mouse liver. The activities of aspartate aminotransferase (AST), alkaline phosphatase (ALP), alanine aminotransferase (ALT), and gamma-glutamyltransferase (GGT), biomarkers of tissue injury, were determined in liver homogenates and serum. The proportions of 18:2n-6, 20:4n-6, 20:5n-3, and 22:6n-3 (polyunsaturated fatty acids, from 37 to 60%) in the total fatty acid content were increased in the liver of the bullfrog oil-treated group (P < 0.05) compared to control. At the same time, a significant decrease in the relative abundance of 14:0, 16:0, and 18:0 (saturated fatty acids, from 49 to 25%) was observed. The hepatic content of thiobarbituric acid reactive substances (TBARS) was increased from 2.3 ± 0.2 to 12.3 ± 0.3 nmol TBA-MDA/mg protein and catalase activity was increased from 840 ± 32 to 1110 ± 45 µmol reduced H2O2 min-1 mg protein-1 in the treated group. Bullfrog oil administration increased AST and ALP activities in the liver (from 234.10 ± 0.12 to 342.84 ± 0.13 and 9.38 ± 0.60 to 20.06 ± 0.27 U/g, respectively) and in serum (from 95.41 ± 6.13 to 120.32 ± 3.15 and 234.75 ± 11.5 to 254.41 ± 2.73 U/l, respectively), suggesting that this treatment induced tissue damage. ALT activity was increased from 287.28 ± 0.29 to 315.98 ± 0.34 U/g in the liver but remained unchanged in serum, whereas the GGT activity was not affected by bullfrog oil treatment. Therefore, despite the interesting modulation of fatty acids by bullfrog oil, a possible therapeutic use requires care since some adverse effects were observed in liver.

An extract of Polygonum multiflorum protects against free radical damage induced by ultraviolet B irradiation of the skin

Over the last decades, the incidence of ultraviolet B (UVB)-related skin problems has been increasing. Damages induced by UVB radiation are related to mutations that occur as a result of direct DNA damage and/or the production of reactive oxygen species. We investigated the anti-oxidant effects of a Polygonum multiflorum thumb extract against skin damage induced by UVB irradiation. Female SKH-1 hairless mice were divided into three groups: control (N = 7), distilled water- (N = 10), and P. multiflorum extract-treated (PM, N = 10) groups. The PM (10 g) was extracted with 100 mL distilled water, cryo-dried and 9.8 g was obtained. The animals received a topical application of 500 µL distilled water or PM extract (1, 2, 4, 8, and 16%, w/v, dissolved in distilled water) for 30 min after UVB irradiation (wavelength 280-320 nm, 300 mJ/cm²; 3 min) of the dorsal kin for 14 days, and skin immunohistochemistry and Cu,Zn-superoxide dismutase (SOD1) activity were determined. SOD1 immunoreactivity, its protein levels and activities in the skin were significantly reduced by 70% in the distilled water-treated group after UVB irradiation compared to control. However, in the PM extract-treated groups, SOD1 immunoreactivity and its protein and activity levels increased in a dose-dependent manner (1-16%, w/v, PM extract) compared to the distilled water-treated group. SOD1 protein levels and activities in the groups treated with 8 and 16%, w/v, PM extract recovered to 80-90% of the control group levels after UVB. These results suggest that PM extract strongly inhibits the destruction of SOD1 by UV radiation and probably contains anti-skin photoaging agents.