Pregnancy outcome post renal transplantation

BACKGROUND: The success in performing organ transplantations and prevention of rejection has resulted not only in a substantial increase in life expectancy, but also improvement in the patients' quality of life. Thus, women who underwent organ transplantation are now reaching puberty and the age of reproduction. This has presented new challenges regarding the teratogenicity and the long-term effect of immunosuppressive medications used by these patients. Previous studies have shown that pregnancies after renal transplantation are associated with an increased risk for both the mother and the fetus. There is, however, very little information available on neonatal and long-term pediatric follow-up of babies born to mothers who have undergone renal transplantation and have been exposed to immunosuppressive medications, compared to controls. We report the experience of our center, the largest in Canada, regarding the prenatal and long-term postnatal outcome of pregnancies after renal transplantation. METHODS: This is a retrospective case series reporting the outcome of 44 consecutive pregnancies followed by the Toronto Renal Transplant Program. Follow-up data were gathered on the 32 live born children by either a return visit to the clinic or by telephone interview. Medical, as well as developmental information, was gathered on all children and the study group was compared to controls, matched for maternal age (+/-2 years) and smoking status, obtained through the Motherisk Program. RESULTS: Of the 44 pregnancies followed by us, there were 32 live-born children delivered by 26 mothers and 12 stillborn/abortuses. Twenty-six pregnancies were treated with cyclosporine, azathioprine and prednisone, 13 with azathioprine and prednisone and five with cyclosporine and prednisone. The mean gestational age at delivery in the study group was 36.5 +/- 2.7 weeks compared to 40.2 +/- 1.6 weeks in the control group (P < 0.001). The mean birthweight in the study group was 2.54 +/- 0.67 kg, compared to 3.59 +/- 0.53 kg in the control group (P < 0.0001). In the study group there was one child with multiple anomalies and four stillbirths compared to zero in the control group. There were also six spontaneous abortions and two therapeutic abortions in the study group. On follow-up (from 3 months to 11 years of age) there was one child with insulin-dependent diabetes mellitus, two children with asthma and one child with recurrent otitis media. Developmental follow-up revealed one child with moderate to severe sensorineural hearing loss, one child with a learning disability and one child with pervasive developmental disorder. In none of these cases were there signs of perinatal asphyxia. CONCLUSION: There are significantly more stillbirths, preterm deliveries and increased incidence of low birth weight in the transplant group. Most pregnancies in the study group went well, however, and their offspring had normal postnatal growth and development. Further studies with long-term pediatric follow-up are needed to delineate their outcome and rule out possible long term effects of the immunosuppressive medication on their growth, development, reproduction and general health.     

Chondrogenic potential of adipose tissue-derived stromal cells in vitro and in vivo.

Articular cartilage exhibits little intrinsic repair capacity, and new tissue engineering approaches are being developed to promote cartilage regeneration using cellular therapies. The goal of this study was to examine the chondrogenic potential of adipose tissue-derived stromal cells. Stromal cells were isolated from human subcutaneous adipose tissue obtained by liposuction and were expanded and grown in vitro with or without chondrogenic media in alginate culture. Adipose-derived stromal cells abundantly synthesized cartilage matrix molecules including collagen type II, VI, and chondroitin 4-sulfate. Alginate cell constructs grown in chondrogenic media for 2 weeks in vitro were then implanted subcutaneously in nude mice for 4 and 12 weeks. Immunohistochemical analysis of these samples showed significant production of cartilage matrix molecules. These findings document the ability of adipose tissue-derived stromal cells to produce characteristic cartilage matrix molecules in both in vitro and in vivo models, and suggest the potential of these cells in cartilage tissue engineering.     

The Hansenula polymorpha (strain CBS4732) genome sequencing and analysis

The methylotrophic yeast Hansenula polymorpha is a recognised model system for investigation of peroxisomal function, special metabolic pathways like methanol metabolism, of nitrate assimilation or thermostability. Strain RB11, an odc1 derivative of the particular H. polymorpha isolate CBS4732 (synonymous to ATCC34438, NRRL-Y-5445, CCY38-22-2) has been developed as a platform for heterologous gene expression. The scientific and industrial significance of this organism is now being met by the characterisation of its entire genome. The H. polymorpha RB11 genome consists of approximately 9.5 Mb and is organised as six chromosomes ranging in size from 0.9 to 2.2 Mb. Over 90% of the genome was sequenced with concomitant high accuracy and assembled into 48 contigs organised on eight scaffolds (supercontigs). After manual annotation 4767 out of 5933 open reading frames (ORFs) with significant homologies to a non-redundant protein database were predicted. The remaining 1166 ORFs showed no significant similarity to known proteins. The number of ORFs is comparable to that of other sequenced budding yeasts of similar genome size.     

Advanced glycation end-product (AGE)-damaged IgG and IgM autoantibodies to IgG-AGE in patients with early synovitis

Advanced glycation end-product (AGE)-damaged IgG occurs as a result of hyperglycemia and/or oxidative stress. Autoantibodies to IgG-AGE were previously demonstrated in patients with severe, longstanding rheumatoid arthritis (RA). We investigated whether IgG-AGE and anti-IgG-AGE antibodies were present early in the course of RA and other inflammatory arthropathies. We prospectively followed a cohort of 238 patients with inflammatory arthritis of duration less than 1 year. Patients were evaluated clinically and serologically, and radiographs were obtained at initial and 1-year visits. Sera were assayed for IgG-AGE and anti-IgG-AGE antibodies by enzyme-linked immunosorbent assay (ELISA). Rheumatoid factor (RF) was determined by nephelometry and ELISA. Of all patients, 29% had RF-positive RA, 15% had RF-negative RA, 18% had spondyloarthropathy, and 38% had undifferentiated arthritis. IgG-AGE was present in 19% of patients, and was similar in amount and frequency in all groups. Patients with elevated IgG-AGE levels had significantly higher levels of the inflammatory markers C-reactive protein and erythrocyte sedimentation rate, but there was no correlation with blood glucose levels. Overall, 27% of the patients had IgM anti-IgG-AGE antibodies. These antibodies were highly significantly associated with RFs (P < 0.0001) and with swollen joint count (P < 0.01). In early onset arthritis, IgG damaged by AGE was detected in all patient groups. The ability to make IgM anti-IgG-AGE antibodies, however, was restricted to a subset of RF-positive RA patients with more active disease. The persistence of the anti-IgG-AGE response was more specific to RA, and was transient in the patients with spondyloarthropathy and with undifferentiated arthritis who were initially found to be positive for anti-IgG-AGE antibodies.     

Ultrastructural changes in the muscles,midgut, hemopoietic organ,imaginal discs and Malpighian tubules of the mosquito Aedes aegypti larvae infected by the fungus Coelomomyces stegomyiae

Fungi belonging to the genus Coelomomyces can infect mosquito larvae and develop within the larval hemocoel. To examine fungal development, Aedesaegypti larvae infected with Coelomomyces stegomyiae Keilin were fixed, embedded and sectioned for both light and electron microscopy. While fungal hyphae of C. stegomyiae did not invade cells other than the cuticular epithelial cells, they did penetrate a number of tissues including muscles, midgut, hemopoietic organ, imaginal discs, and Malpighian tubules. This revised version was published online in July 2006 with corrections to the Cover Date.     

The RNA binding protein Larp1 regulates cell division,apoptosis and cell migration

The RNA binding protein Larp1 was originally shown to be involved in spermatogenesis, embryogenesis and cell-cycle progression in Drosophila. Our data show that mammalian Larp1 is found in a complex with poly A binding protein and eukaryote initiation factor 4E and is associated with 60S and 80S ribosomal subunits. A reduction in Larp1 expression by siRNA inhibits global protein synthesis rates and results in mitotic arrest and delayed cell migration. Consistent with these data we show that Larp1 protein is present at the leading edge of migrating cells and interacts directly with cytoskeletal components. Taken together, these data suggest a role for Larp1 in facilitating the synthesis of proteins required for cellular remodelling and migration.     

Neuronal Types in the Human Anterior Ventral Thalamic Nucleus: A Golgi Study

Neurons in the anterior ventral (AV) thalamic nucleus of human adults were impregnated by Golgi-Kopsch impregnation method. Results showed that at least three morphological types of neurons could be recognized in the human AV thalamic nucleus. Type I neurons were medium to large with rich dendritic arborization. Both tufted and radiating dendritic branching patterns were seen in almost every neuron of this type. Only the initial axonal segments of these cells were impregnated suggesting that these axons were heavily myelinated. Type II neurons were medium in size with poor to moderate dendritic arborization. Many of these cells possess a few dendritic grape-like appendages. Long segments (up to 300 μm) of their axons were impregnated suggesting that these axons were either unmyelinated or thinly myelinated. These axons change their direction and form loops very often. No local branches were seen for these axons suggesting that they could be projection axons. Type III neurons were small with only one or two dendrites with poor arborization. No axons for these cells were seen in this study. The three neuronal types in the human AV thalamic nucleus were compared with neuronal types already described in other thalamic nuclei of human and non-human species. The results of this study might provide a morphological basis for further electrophysiological and / or pathological studies.     

Selection of an improved RNA polymerase ribozyme with superior extension and fidelity

Our current understanding of biology suggests that early life relied predominantly on RNA for catalysis and replication. Here, we report the isolation of an RNA polymerase ribozyme called B6.61 that exhibits superior extension and fidelity relative to its progenitor, the Round-18 polymerase. The B6.61 polymerase was selected from a mutagenized pool containing approximately 9 x 10(14) sequence variants through the use of a novel large-scale in vitro compartmentalization system. B6.61 polymerized all tested primer-template (PT) complexes faster than the Round-18 variant. For one PT, B6.61 exhibited dramatically faster elongation past one full helical turn and incorporated at least 20 nucleotides of sequence, setting a new extension record for an RNA polymerase ribozyme. The increased efficiency of the B6.61 construct was related to improvements in fidelity, with the new variant incorporating less incorrect wobble base pairs than its parent. This new polymerase demonstrates the feasibility of evolving an artificial RNA replicase ribozyme in the foreseeable future.     

Geographical distribution of principal cereal weeds in setif high plains

The invasion of the wheat and barley cultures by weeds remains among the major problems of agriculture in Algeria considering the importance of yield tosses caused by these species. The cereal yields average is less than 700 kg ha(-1). The main purpose of this work was to obtain informations on geographical distribution of principal cereal weeds in the setif high plains. Two bioclimatic areas may be distinguished in this region, the semi-arid in the south and the sub-humid in the north. One hundred ten fields of cereals were surveyed by stratified sampling. In each field the level of infestation was scored on a homogeneous surface. The weediness of the species was estimated on the basis of the frequency and average of abundance. The results indicate thirty four important species. This harmful flora was characterized by the prevalence of annual and brod leaved weeds. The study of the geographical distribution cards of these species shows three groups: species related to the northern zone, species related to the southern zone and species common to both zone. The knowledge of the geographical distribution of principal weeds is an essential element for any plan of integrated weed management.     

The response regulator PmrA is a major regulator of the icm/dot type IV secretion system in Legionella pneumophila and Coxiella burnetii

Legionella pneumophila and Coxiella burnetii have been shown to utilize the icm/dot type IV secretion system for pathogenesis and recently a large number of icm/dot-translocated substrates were identified in L. pneumophila. Bioinformatic analysis has revealed that 13 of the genes encoding for L. pneumophila-translocated substrates and five of the C. burnetii icm/dot genes, contain a conserved regulatory element that resembles the target sequence of the PmrA response regulator. Experimental analysis which included the construction of a L. pneumophila pmrA deletion mutant, intracellular growth analysis, comparison of gene expression between L. pneumophila wild type and the pmrA mutant, construction of mutations in the PmrA conserved regulatory element, controlled expression studies as well as mobility shift assays, demonstrated the direct relation between the PmrA regulator and the expression of L. pneumophila icm/dot-translocated substrates and several C. burnetii icm/dot genes. Furthermore, genomic analysis identified 35 L. pneumophila and 68 C. burnetii unique genes that contain the PmrA regulatory element and few of these genes from L. pneumophila were found to be new icm/dot-translocated substrates. Our results establish the PmrA regulator as a fundamental regulator of the icm/dot type IV secretion system in these two bacteria.