Antigenic differences between Anabaena azollae fresh from the Azolla fern leaf cavity and free-living cyanobacteria

Fluorescent antibody staining indicated differences in surface antigenicity in Anabaena azollae cells fresh from the leaf cavities of the fern, Azolla caroliniana, and algae which were isolated and subcultured from this fern. Such results suggest that either changes in antigenicity occur in this phycobiont during culturing or that isolation selects for an antigenically different mutant strain capable of in vitro growth.Non-Standard Abbreviations FA fluorescent antibody staining - PBS phosphate buffered saline - W microwatt - Anti-F antiserum prepared against fresh cells - Anti-N antiserum prepared against Newton's culture - FTTC fluorescein isothiocyanate To whom offprint requests should be sent     

The Effects of Root-knot Nematode Infection and Mi-mediated Nematode Resistance in Tomato on Plant Fitness

The Mi-1.2 resistance gene in tomato (Solanum lycopersicum) confers resistance against several species of root-knot nematodes (Meloidogyne spp.). This study examined the impact of M. javanica on the reproductive fitness of near-isogenic tomato cultivars with and without Mi-1.2 under field and greenhouse conditions. Surprisingly, neither nematode inoculation or host plant resistance impacted the yield of mature fruits in field microplots (inoculum=8,000 eggs/plant), or fruit or seed production in a follow-up greenhouse bioassay conducted with a higher inoculum level (20,000 eggs/plant). However, under heavy nematode pressure (200,000 eggs/plant), greenhouse-grown plants carrying Mi-1.2 had more than ten-fold greater fruit production than susceptible plants and nearly forty-fold greater estimated lifetime seed production, confirming prior reports of the benefits of Mi-1.2. In all cases Mi-mediated resistance significantly reduced nematode reproduction. These results indicated that tomato can utilize tolerance mechanisms to compensate for moderate levels of nematode infection, but that the Mi-1.2 resistance gene confers a dramatic fitness benefit under heavy nematode pressure. No significant cost of resistance was detected in the absence of nematode infection.     

Dark-mediated dormancy release in stratified Lolium rigidum seeds is associated with higher activities of cell wall-modifying enzymes and an apparent increase in gibberellin sensitivity

Dormancy release in freshly matured, imbibed annual ryegrass (Lolium rigidum) seeds is inhibited by light and involves a decrease in seed sensitivity to abscisic acid. Other processes involved in dormancy release in the dark were investigated by measuring seed storage compound mobilisation and the activity of cell wall-degrading enzymes. Activities of endo-β-mannanase and total peroxidase were higher in dark-stratified compared to light-stratified seeds, indicating that weakening of the structures constraining the embryo was accelerated in the dark. A dramatic degradation of storage proteins in light-stratified seeds, accompanied by induction of a high molecular mass protease, suggests that maintenance of storage(-like) proteins is also important in dark-mediated dormancy release. α-Amylase activity was induced in dark-stratified seeds at least 48 h prior to radicle emergence upon transfer to conditions permitting germination, or in light-stratified seeds supplied with exogenous gibberellin A₄. This suggests that (a) α-amylase is involved in stimulation of germination of non-dormant L. rigidum seeds, and (b) dark-stratified seeds have an increased sensitivity to gibberellins which permits the rapid induction of α-amylase activity upon exposure to germination conditions. Overall, it appears that a number of processes, although possibly minor in themselves, occur in concert during dark-stratification to contribute to dormancy release.     

Microsomal and cytosolic cytochrome P450 mediated benzo(a)pyrene hydroxylation in Pleurotus pulmonarius

Summary Microsomal and soluble fractions of Pleurotus pulmonarius exhibited a reduced carbon monoxide difference spectrum with P450 maxima at 448nm and 450–452nm respectively. Substrate induced Type I spectra were observed on addition of benzo(a)pyrene to both fractions. Benzo(a)pyrene hydroxylation was measured using the aryl hydrocarbon hydroxylase assay and was observed to be P450 dependent as indicated by carbon monoxide inhibition together with the substrate binding characteristics. The activity of the fractions were observed to give K_m of 200mM and 660mM and V_max of 1.25 nmol/min/nmol P450 and 0.57 nmol/min/nmol P450 for the microsomal and cytosolic fractions respectively.     

Human β-glucuronidase: Assignment of the structural gene to chromosome 7 using somatic cell hybrids

-Glucuronidase (GUS) has become an important enzyme model for the genetic study of molecular disease, enzyme realization, and therapy, and for the biogenesis and function of the lysosome and lysosomal enzymes. The genetics of human -glucuronidase was investigated utilizing 188 primary man-mouse and man-Chinese hamster somatic cell hybrids segregating human chromosomes. Cell hybrids were derived from 16 different fusion experiments involving cells from ten different and unrelated individuals and six different rodent cell lines. The genetic relationship of GUS to 28 enzyme markers representing 19 linkage groups was determined, and chromosome studies on selected cell hybrids were performed. The evidence indicates that the -glucuronidase gene is assigned to chromosome 7 in man. Comparative linkage data in man and mouse indicate that the structural gene GUS is located in a region on chromosome 7 that has remained conserved during evolution. Involvement of other chromosomes whose genes may be important in the final expression of GUS was not observed. A tetrameric structure of human -glucuronidase was demonstrated by the formation of three heteropolymers migrating between the human and mouse molecular forms in chromosome 7 positive cell hybrids. Linkage of GUS to other lysosomal enzyme genes was investigated. -Hexosaminidase HEX _B) was assigned to chromosome 5; acid phosphatase₂ (ACP ₂) and esterase A₄ (ES-A ₄) were assigned to chromosome 11; HEX _A was not linked to GUS; and -galactosidase (-GAL) was localized on the X chromosome. These assignments are consistent with previous reports. Evidence was not obtained for a cluster of lysosomal enzyme structural genes. In demonstrating that GUS was not assigned to chromosome 9 utilizing an X/9 translocation segregating in cell hybrids, the gene coding for human adenylate kinase₁ was confirmed to be located on chromosome 9.Supported by NIH Grants HD 05196, GM 20454, and GM 06321, by NSF Grant BMS 73-07072, and by HEW Maternal and Child Health Service, Project 417.     

Conservation of sequence in the internal transcribed spacers and 5.8S ribosomal RNA among geographically separated isolates of parasitic scuticociliates (Ciliophora, Orchitophryidae)

Nucleotide sequence from the internal transcribed spacers (ITS1 and ITS2) and the 5.8S gene from the ribosomal RNA gene cluster of isolates of the scuticociliate Orchitophrya stellarum from 4 asteroid hosts were compared. Surprisingly, these data (495 bp) were identical for O. stellarum isolated from the testes of Asterias amurensis from Japan; Pisaster ochraceus from British Columbia, Canada; Asterias rubens from The Netherlands; and Asterias vulgaris from Prince Edward Island, Canada. These sequence data were compared to those from 3 scuticociliates which parasitise crustaceans: Mesanophrys pugettensis, M. chesapeakensis and Anophryoides haemophila. No difference was found in this region between the nucleotide sequence of M. pugettensis and M. chesapeakensis. The sequence of Mesanophrys spp. differed by 9.2% in the ITS1 and 4.7% in the ITS2 from that of O. stellarum. The sequence from the ITS1 (135 bp) and ITS2 (233 bp) of A. haemophila differed by 42.6 and 20.5% respectively from those of O. stellarum. Therefore, nucleotide sequence of the ITS regions in these scuticociliates is highly conserved.     

Evaluation of an adapted version of the Diabetes Prevention Program for low- and middle-income countries: A cluster randomized trial to evaluate “Lifestyle Africa” in South Africa

BackgroundLow- and middle-income countries (LMICs) are experiencing major increases in diabetes and cardiovascular conditions linked to overweight and obesity. Lifestyle interventions such as the United States National Diabetes Prevention Program (DPP) developed in high-income countries require adaptation and cultural tailoring for LMICs. The objective of this study was to evaluate the efficacy of “Lifestyle Africa,” an adapted version of the DPP tailored for an underresourced community in South Africa compared to usual care.Methods and findingsParticipants were residents of a predominantly Xhosa-speaking urban township of Cape Town, South Africa characterized by high rates of poverty. Participants with body mass index (BMI) ≥ 25 kg/m² who were members of existing social support groups or “clubs” receiving health services from local nongovernmental organizations (NGOs) were enrolled in a cluster randomized controlled trial that compared Lifestyle Africa (the intervention condition) to usual care (the control condition). The Lifestyle Africa intervention consisted of 17 video-based group sessions delivered by trained community health workers (CHWs). Clusters were randomized using a numbered list of the CHWs and their assigned clubs based on a computer-based random allocation scheme. CHWs, participants, and research team members could not be blinded to condition. Percentage weight loss (primary outcome), hemoglobin A1c (HbA1c), blood pressure, triglycerides, and low-density lipoprotein (LDL) cholesterol were assessed 7 to 9 months after enrollment. An individual-level intention-to-treat analysis was conducted adjusting for clustering within clubs and baseline values. Trial registration is at ClinicalTrials.gov ({"type":"clinical-trial","attrs":{"text":"NCT03342274","term_id":"NCT03342274"}}NCT03342274). Between February 2018 and May 2019, 782 individuals were screened, and 494 were enrolled. Participants were predominantly retired (57% were receiving a pension) and female (89%) with a mean age of 68 years. Participants from 28 clusters were allocated to Lifestyle Africa (15, n = 240) or usual care (13, n = 254). Fidelity assessments indicated that the intervention was generally delivered as intended. The modal number of sessions held across all clubs was 17, and the mean attendance of participants across all sessions was 61%. Outcome assessment was completed by 215 (90%) intervention and 223 (88%) control participants. Intent-to-treat analyses utilizing multilevel modeling included all randomized participants. Mean weight change (primary outcome) was −0.61% (95% confidence interval (CI) = −1.22, −0.01) in Lifestyle Africa and −0.44% (95% CI = −1.06, 0.18) in control with no significant difference (group difference = −0.17%; 95% CI = −1.04, 0.71; p = 0.71). However, HbA1c was significantly lower at follow-up in Lifestyle Africa compared to the usual care group (mean difference = −0.24, 95% CI = −0.39, −0.09, p = 0.001). None of the other secondary outcomes differed at follow-up: systolic blood pressure (group difference = −1.36; 95% CI = −6.92, 4.21; p = 0.63), diastolic blood pressure (group difference = −0.39; 95% CI = −3.25, 2.30; p = 0.78), LDL (group difference = −0.07; 95% CI = −0.19, 0.05; p = 0.26), triglycerides (group difference = −0.02; 95% CI = −0.20, 0.16; p = 0.80). There were no unanticipated problems and serious adverse events were rare, unrelated to the intervention, and similar across groups (11 in Lifestyle Africa versus 13 in usual care). Limitations of the study include the lack of a rigorous dietary intake measure and the high representation of older women.ConclusionsIn this study, we found that Lifestyle Africa was feasible for CHWs to deliver and, although it had no effect on the primary outcome of weight loss or secondary outcomes of blood pressure or triglycerides, it had an apparent small significant effect on HbA1c. The study demonstrates the potential feasibility of CHWs to deliver a program without expert involvement by utilizing video-based sessions. The intervention may hold promise for addressing cardiovascular disease (CVD) and diabetes at scale in LMICs.Trial registrationClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT03342274","term_id":"NCT03342274"}}NCT03342274.

In a cluster randomized trial, Delwyn Catley and colleagues evaluate an adapted version of the Diabetes Prevention Program in South Africa.     

Prenatal Alcohol Exposure Modifies Glucocorticoid Receptor Subcellular Distribution in the Medial Prefrontal Cortex and Impairs Frontal Cortex-Dependent Learning

Prenatal alcohol exposure (PAE) has been shown to impair learning, memory and executive functioning in children. Perseveration, or the failure to respond adaptively to changing contingencies, is a hallmark on neurobehavioral assessment tasks for human fetal alcohol spectrum disorder (FASD). Adaptive responding is predominantly a product of the medial prefrontal cortex (mPFC) and is regulated by corticosteroids. In our mouse model of PAE we recently reported deficits in hippocampal formation-dependent learning and memory and a dysregulation of hippocampal formation glucocorticoid receptor (GR) subcellular distribution. Here, we examined the effect of PAE on frontal cortical-dependent behavior, as well as mPFC GR subcellular distribution and the levels of regulators of intracellular GR transport. PAE mice displayed significantly reduced response flexibility in a Y-maze reversal learning task. While the levels of total nuclear GR were reduced in PAE mPFC, levels of GR phosphorylated at serines 203, 211 and 226 were not significantly changed. Cytosolic, but not nuclear, MR levels were elevated in the PAE mPFC. The levels of critical GR trafficking proteins, FKBP51, Hsp90, cyclophilin 40, dynamitin and dynein intermediate chain, were altered in PAE mice, in favor of the exclusion of GR from the nucleus, indicating dysregulation of GR trafficking. Our findings suggest that there may be a link between a deficit in GR nuclear localization and frontal cortical learning deficits in prenatal alcohol-exposed mice.