GREGOR KOSEC^*¶, VANINA ALVAREZ^**¶, JUAN J. CAZZULO**

BIOCELL, Vol.30, No.3, pp. 479-490, 2006, DOI:10.32604/biocell.2006.30.479

Abstract Trypanosoma cruzi, the parasite causing Chagas disease, contains a number of proteolytic enzymes. The recent completion of the genome sequence of the T. cruzi CL Brener clone suggests the presence of 70 cysteine peptidases, 40 serine peptidases (none of them from the chymotrypsin family), about 250 metallopeptidases (most leishmanolysin homologues), 25 threonine peptidases, and only two aspartyl peptidases, none of them from the pepsin family. The cysteine peptidases belong to 7 families of Clan CA, 3 families of Clan CD, and one each of Clans CE and CF. In Clan CA, the C1 family is represented by More >

ANDREA BOZZO*, CARLOS ALBERTO SOÑEZ*, MARÍA TERESA MUGNAINI*, ISABEL CECILIA PASTORINO*, ALICIA NÉLIDA ROLANDO*, MARÍA CRISTINA ROMANINI*, HÉCTOR FERNANDO GAUNA**

BIOCELL, Vol.30, No.3, pp. 439-445, 2006, DOI:10.32604/biocell.2006.30.439

Abstract Chronic stress by immobilization during gestation can alter several mechanisms that maintain homeostasis in adrenal gland. The aim of this work was to quantify the apoptotic index of adrenal cortex during mid-pregnancy and to prove cytological characteristics by electron microscopy. The apoptotic index did not present significant differences between the adrenal cortex areas of control and experimental rats in any of the three ages studied. The day of gestation influenced significantly on the apoptotic index in both groups. This index increased as gestation progressed. It may be concluded that chronic stress by immobilization might induce More >

M.E. RÜTTLER, C.S. YANZÓN, M.J. CUITIÑO, N.F. RENNA, M.A. PIZARRO, A.M. ORTIZ.

BIOCELL, Vol.30, No.2, pp. 301-308, 2006, DOI:10.32604/biocell.2006.30.301

Abstract Enteroaggregative Escherichia coli (EAEC) has been implicated in sporadic diarrhea in children and adults and has been identified as the cause of several outbreaks worldwide. The HEp-2 test remains the gold standard for identification of this pathotype. A 60-65 MDa plasmid encodes the aggregative adherence fimbriae (AAF/I and AAF/II), a transcriptional activator (aggR gene), the enteroaggregative heat-stable enterotoxin EAST1 (astA gene) and a cytotoxin (Pet). The standard assay for EAEC is performed only in research laboratories, because it is expensive, labor intensive and time-consuming. The Polymerase Chain Reaction (PCR) offers the possibility of rapid diagnosis. In the… More >

R. B. SCIURANO, M.S. MERANI, JIMENA BUSTOS, A.J. SOLARI

BIOCELL, Vol.30, No.1, pp. 57-66, 2006, DOI:10.32604/biocell.2006.30.057

Abstract Spermatocytes from the two armadillo species, C. villosus and D. hybridus were studied in microspreads for synaptonemal complexes (SCs) and in thin sections for electron microscopy (EM). The complete SC karyotype generally agrees with previous reports on mitotic chromosomes, except for the sex chromosomes. The X chromosome is submetacentric in both species and the Y is the shortest one in C. villosus and the second shortest in D. hybridus, and an extremely acrocentric one. A SC is formed along the total length of the Y chromosome, and this SC persists along all the pachytene substages. A single recombination nodule… More >

LEONOR M.E. ITUARTE*, TERESA B. VIERA*, TEOBALDO A. SALDEÑA*, JUAN C. DE ROSAS**, MABEL FÓSCOLO**, JORGE E. IBÁÑEZ*, FERNANDO D. SARAVÍ*

BIOCELL, Vol.30, No.1, pp. 43-49, 2006, DOI:10.32604/biocell.2006.30.043

Abstract Electrophysiological events occur early after fertilization, along with changes in intracellular Ca²⁺ concentration . Passive electrical parameters were determined in golden hamster oocytes by whole cell patch-clamp method. In separate experiments the effect of 4-aminopyridine on resting oocytes was tested. The single-channel patch clamp configuration was employed to assess the electrical response to fertilization with homologous sperm. Structure of oocytes submitted to patch clamp was evaluated with scanning electron microscopy and found to be preserved.
Oocyte diameter was 70.2 ± 2.2 µm; their resting parameters were: membrane potential 23.8 ± 0.8 mV; total membrane specific… More >

MARÍA DE LOS A. ALVAREZ, NORA B. DEBATTISTA, NORA B. PAPPANO

BIOCELL, Vol.30, No.1, pp. 39-42, 2006, DOI:10.32604/biocell.2006.30.039

Abstract In our previous studies, bacteriostatic action of flavonoids against Staphylococcus aureus ATCC 25 923 and Escherichia coli ATCC 25 922 was demostrated. In the present work synergism of their combinations in order to improve the bacteriostatic action against the same microorganisms was determined. The experiences were made in nutritive broth, maintaining constant one drug concentration (20 µg/ml) and increasing the other one. A turbidimetric kinetic method was used and by means of a mechanism previously proposed, the minimal inhibitory concentrations (MIC´s) of each flavonoid combination were determined. The MIC´s for assayed combinations against S. aureus were: variable morin More >

MARIA CAROLINA AQUINO LUQUE, SÔNIA NAIR BÁO

BIOCELL, Vol.30, No.1, pp. 33-38, 2006, DOI:10.32604/biocell.2006.30.033

Abstract The ultrastructure of normal, ejaculated spermatozoa of Bos indicus was studied by means of electron microscopy, being evaluated in two principal parts, the head and the tail. The head is flat, oval or paddle-shaped with a square base, which provides a concave recess for the insertion of the tail. The acrosome tightly covers the anterior two thirds of the nucleus. A distinct unilateral acrosomal bulge was observed along the apical edge of the head. The equatorial region demarcates the acrosome from the post-equatorial region that covers the caudal one third of the nucleus. The classical 9+9+2 More >

ZONG-YUN LI^1,2*, MEI-LI FU¹, FANG-FANG HU¹, SHU-FENG HUANG¹, YUN-CHUN SONG²

BIOCELL, Vol.30, No.1, pp. 27-32, 2006, DOI:10.32604/biocell.2006.30.027

Abstract The ribosomal DNA (45S rDNA) behaviors during the cell cycle were analyzed on interphase nuclei, prophases, metaphases, pachytene chromosomes and extended DNA fibers in rice (Oryza,sativa ssp.indica cv.Guangluai No.4) by using high-resolution fluorescent in situ hybridization (FISH). The results show that 45S rDNA is located at the ends of short arms of chromosomes 9 and 10. But the signals are much more intense on chromosome 9 than on chromosome 10 in metaphase. Pachytene chromosome has rDNA signal arrays on chromosome 9. Different phases are described and discussed. These results indicate that the activity of rDNA at individual More >

JUAN LIN¹, XUANWEI ZHOU², JIONG FEI², ZHIHUA LIAO¹, WANG JIN¹, XIAOFEN SUN^1,*, KEXUAN TANG^1,2,*

BIOCELL, Vol.30, No.1, pp. 15-25, 2006, DOI:10.32604/biocell.2006.30.015

Abstract A gene encoding a mannose-binding lectin, Pinellia pedatisecta agglutinin (PPA), was isolated from leaves of Pinellia pedatisecta using genomic walker technology. The ppa contained an 1140-bp 5’-upstream region, a 771-bp open reading frame (ORF) and an 829-bp 3’-downstream region. The ORF encoded a precursor polypeptide of 256 amino acid residues with a 24-amino acid signal peptide. There were one putative TATA box and six possible CAAT boxes lying in the 5’-upstream region of ppa. The ppa showed significant similarity at the nucleic acid level with genes encoding mannose-binding lectins from other Araceae species such as Pinellia ternata, Arisaema heterophyllum, Colocasia esculenta More >

Hernández-Castillo¹ FD, Adalberto Aguirre-Aguirre¹, RH Lira-Saldivar², E Guerrero-Rodríguez¹, G Gallegos-Morales¹

Phyton-International Journal of Experimental Botany, Vol.75, pp. 91-101, 2006, DOI:10.32604/phyton.2006.75.091

Abstract The biological efficiency of five stocks of Bacillus subtilis, of the mixture of the bioproducts quitosan and Larrea tridentata extract, and five synthetic fungicides were evaluated against the fungus Alternaria dauci Kühn in laboratory and greenhouse experiments. The effect of these compounds on growth and yield of carrot was also determined. Stocks of the bacteria Bacillus (B3, B9, B15 and a combination of these) and the mixture quitosan- Larrea stimulated carrot development because it reached greater width, length and weight in comparison to the control and the other treatments. Stock B3 was the best in promoting carrot growth More >