Postinfection Activity of Synthetic Antimicrobial Peptides Against Stemphylium vesicarium in Pear.

Brown spot of pear is a fungal disease of economic importance caused by Stemphylium vesicarium that affects the pear crops in Europe. Due to the characteristics of this disease and the moderate efficacy of available fungicides, the effectiveness of control measures is very limited; however, synthetic antimicrobial peptides (AMPs) may be a complement to these fungicides. In the present study, 12 AMPs of the CECMEL11 library were screened for fungicidal activity against S. vesicarium. In vitro experiments showed that eight AMPs significantly reduced the germination of conidia. The most effective peptides, BP15, BP22, and BP25, reduced fungal growth and sporulation at concentrations below 50 µM. Leaf assays showed that preventive application of BP15 and BP22 did not reduce infection; however, when the peptides were applied curatively, infection was significantly reduced. The use of a BP15 fluorescein 5-isothiocyanate conjugate revealed that the peptide binds to hyphae and germ tubes and produces malformations that irreversibly stop their development.

Adherence of Pasteurella multocida to rabbit respiratory epithelial cells in vitro.

Adult clinically healthy New Zealand rabbits were sampled bacteriologically to detect carriers and non-carriers of Pasteurella multocida. Both groups of rabbits were killed separately to obtain samples of nasal, buccal, pharyngeal and tracheal epithelial cells. The cells were tested for adherence in vitro to 18 isolates of P. multocida from healthy and sick rabbits, from ovine, bovine, cat and swine. The number of bacteria adhered per cell up to 25 cells per preparation were registered. Analysis of variance was used to interpret the significance of results. Adherence of P. multocida was significantly higher to carrier rabbit cells than to non-carrier rabbit cells. Bacterial isolates from rabbits were more adherent to rabbit cells than to isolates from other species. The frequency was higher to buccal and pharyngeal cells than to nasal and tracheal cells. Isolates from healthy animals adhered better to rabbit cells than isolates from sick animals, except the isolates from sick animals which adhered better to nasal cells of non carriers than did isolates from healthy rabbits.

Molecular differentiation of two different translocations producing two apparent Ph chromosomes in a patient with CML.

A case of chronic myelogenous leukemia (CML) is described whose leukemic cells appeared to contain two Philadelphia (Ph) chromosomes originating from different translocations involving the two chromosomes 22. The karyotype of the affected cells, established on two different occasions, was: 46,XY,t(9;22)(q34;q11),t(15;22)(p11;q11) with no normal chromosomes 22 and only one 9q+ in each of 115 marrow cells examined. The same findings were present in 50 peripheral blood cells cultured without phytohemagglutinin (PHA) stimulation. When stimulated with PHA, a normal male karyotype was present in the 11 cells examined. There were no additional chromosomal abnormalities and no indication of a blastic crisis after nearly 1 year following the original study. Analysis of the breakpoint cluster region (bcr) on chromosome 22 in the DNA of the affected cells (marrow) revealed evidence for one rearranged chromosome 22 and one normal chromosome 22, indicating that the t(15;22) was not due to the usual Ph translocation seen in CML. The results point to the crucial usefulness of molecular analysis in confirming cytogenetic results related to Ph translocations in CML.

Duplication 11q and deletion 5p syndromes due to a reciprocal translocation segregating in four generations.

We report on 2 relatives with duplication 11q and deletion 5p, resulting from an adjacent-1 segregation of a balanced reciprocal translocation 5p15;11q23, segregating in 4 generations of this family. Twelve out of 16 at-risk relatives of inheriting the translocation were shown to be carriers, giving a significant (p less than .05) 3:1 ratio of carriers/noncarriers. The breakpoint on chromosome 11 at q23 is a folate sensitive fragile site into where the proto-oncogene c-ets has been mapped.

Sister-chromatid exchanges and cell kinetics in human and rabbit lymphocytes exposed in vivo and in vitro to 2-bromo-alpha-ergocryptine.

The possible mutagenic and DNA-synthesis inhibitory effects of 2-bromo-alpha-ergocryptine, a new semi-synthetic ergot alkaloid, was studied in human and rabbit lymphocytes exposed to it in vivo and in vitro. The analysis of SCE was mainly used to evaluate potential mutagenicity, and the mitotic and DNA-synthesis inhibition was explored by examining the proportions of first-, second- and third-division metaphases in the corresponding lymphocyte cultures. The results obtained show that 2-bromo-alpha-ergocryptine does not induce SCE in the cell systems tested, or structural chromosome aberrations in human lymphocytes in vivo. On the other hand, a marked mitotic inhibitory effect and associated cell kinetic changes could be clearly attributed to the drug, probably related to its cytotoxicity.

Comparative cytogenetic studies in Macaca arctoides with other species of Macaca and man.

Chromosome studies of 5 males and 5 females of the species Macaca arctoides from Thailand were performed and the G, C and NOR banding patterns obtained for comparison with other species of the genus Macaca and with the human karyotype. The cytogenetic analysis showed a complement of 42 chromosomes. Of the 20 autosomal pairs, 15 are submetacentric and 5 almost metacentric. Pair number 9 presents a large secondary constriction, which corresponds to the only nucleolar organizer region of the whole genome, and has giant satellites in the short arms. In regard to the sex chromosomes, females have a pair of submetacentric chromosomes with a G banding pattern identical to that of the human X, while the males have one X and a very small Y chromosome.

Constitutive heterochromatin polymorphisms in patients with malignant diseases.

The frequency of constitutive heterochromatin heteromorphisms was assessed in peripheral blood cultures of 23 patients with various malignant diseases and in their respective controls, formed by cancer-free same sex siblings of the propositi. The results showed no significant differences between the cancer and the control groups, except for chromosome 1 in breast cancer, where polymorphisms were more frequent in the controls than in the patients. Our results do not support previous data reported by others, and although there are differences in the type of malignancies studied by us and them, we believe that our control group is a more appropriate one for this particular type of study.

Clinical and endocrine spectrum in patients with the 45,X/46,XY karyotype.

Cytogenetic and endocrine studies were performed in five unrelated 45,X/46,XY individuals in an attempt to correlate them with their clinical expression and gonadal morphology. A lack of a consistent pattern between cytogenetic findings and phenotype was observed. Endocrine studies revealed a wide spectrum of hypothalamic, pituitary, and gonadal hormone production as assessed by the base line levels of LH, FSH, T, and delta 4-A and their responses to appropriate exogenous stimulation (LH-RH and HCG). An adequate correlation between endocrine findings with gonadal morphology and phenotype could be established; thus demonstrating that patients with this particular chromosome complement have a functional integrity of the gonadotropin hypothalamic pituitary activity modulated accordingly with the gonadal function of each particular case.

Symmetrical replication patterns and sex chromatin bodies formation of an idic(X)(p22.3::p22.3) chromosome.

The morphologic and staining characteristics of the sex chromatin bodies and the DNA replication patterns were studied in a patient with a 45,X/46,X,idic(X)(p22.3::p22.3) karyotype and in a normal woman. The analysis showed a relatively high frequency of bipartite Barr bodies as well as some variation of the distance, staining intensity, and size relationship between their halves. Regarding the DNA replication studies, in 71% of the cells the abnormal X chromosome showed a synchronous pattern, and in the remaining 29%, in which a slight asynchrony was present, an almost equal proportion of early and late functional and nonfunctional centric halves was observed. Furthermore, the atypical chromosome had a quite similar replication pattern to the late replicating X chromosome of the normal woman, suggesting that its sequence of DNA sythesis was not altered.

Frequency and types of induced and spontaneous chromosome aberrations in relation to cell kinetics.

Induced and spontaneous structural chromosome aberrations (SCA) were studied in a child accidentally radiated with a high dose of 192Ir, and in three sibs with Fanconi's anemia, analyzing by separate first division metaphases (FDM) and second division metaphases (SDM). The results showed that the number of SCA, number of cells with aberrations, and SCA per cell were markedly higher in FDM in all patients. Furthermore, for some type of structural changes like dicentric chromosomes and chromatid interchanges, the differences were particularly striking. The importance of ascertaining FDM identified with proper techniques, for the study of the clastogenic effect of environmental agents and some aspects related to the differences in cytogenetic features found in diverse tissues in Fanconi's anemia are discussed.

Cytogenetic and endocrine studies in a 45,X female subject with spontaneous sexual development.

Cytogenetic and endocrine evaluation of a postpubertal 45,X female subject with Turner's stigmas and spontaneous sexual development was performed. A 45,X chromosomal complement was found in the peripheral blood lymphocytes, bone marrow, and fibroblasts derived from skin and ovaries. Menarche, pubarche, and thelarche occurred at age 12; at age 16 she developed menstrual irregularities, with endometrial bleeding occurring every 60 to 90 days. The ovaries were normal in size, and histologic examination revealed a marked paucity of primordial follicles, increased collagenization, and absence of corpora albicans. Anovulatory cycles with moderately elevated levels of luteinizing hormone (LH) and low follicle-stimulating hormone (FSH) levels were observed. LH-releasing hormone pituitary stimulation induced a normal LH release with a very slight FSH increase. Administration of clomiphene citrate successfully induced a normal-length ovulatory cycle. Similarities in the hormonal situation of this patient and that seen in the Stein-Leventhal syndrome are pointed out.

Frequency of sister chromatid exchanges in severe protein calorie malnutrition.

Nine children with severe protein calorie malnutrition were studied regarding the frequency of sister chromatid exchanges (SCE's) in peripheral blood lymphocytes. The results showed that there was no significant difference between the number of SCE's in the malnourished children as compared to an adequate control group. An interesting finding was that the proportion of 3rd or subsequent division metaphases found in the malnourished children, was higher and significantly different from that seen in the control group.