The Organically Handicapped Child—How Can the Family Physician Help?

The better his understanding of some of the ways in which an organic deficit might affect normal development of the handicapped child, the more able the family physician will be to offer guidance to the family aimed at preventing the development of secondary problems. He can thus be instrumental in helping a child achieve his maximal potential.First, it is important to take into account how the parents'' emotional and intellectual responses to having a defective child may interfere markedly in normal parent-child relationship. Second, ways in which each deficit will limit a child''s exposure to stimuli must not be over-looked. Third, one must consider how a deficit may indirectly distort the normal learning patterns when parents do not make age appropriate demands. Fourth, it is important to understand how specific interference in the area of language skills may cause further developmental retardation. Fifth, one must be aware of special problems that an organically handicapped child must face in the society outside of the family. Last of all, in an older child, one must consider the need for a full scale evaluation to sort out primary and secondary factors in the picture.     

Revisiting the use of Iprodione and Trichoderma in the integrated management of onion white rot

The biocontrol properties of Trichoderma species are well documented, but their effectiveness in antagonism of the problematic Sclerotium cepivorum, the causal agent of white rot in Allium species, appears limited with reports of significant control only relating to deliberately-mutated strains of Trichoderma. Our previous studies have indicated the possibility of using selected naturally-occurring strains of the antagonist in the suppression of other diseases; now in vitro and controlled environment in vivo studies have indicated that a degree of control of Onion White Rot is possible, and that the selected antagonist strains can be used in integrated treatments with Iprodione to good effect. The possible value of such treatments is considered in light of other approaches to the suppression of this continuing problem.     

Phylodynamic Inference of Bacterial Outbreak Parameters Using Nanopore Sequencing

Nanopore sequencing and phylodynamic modeling have been used to reconstruct the transmission dynamics of viral epidemics, but their application to bacterial pathogens has remained challenging. Cost-effective bacterial genome sequencing and variant calling on nanopore platforms would greatly enhance surveillance and outbreak response in communities without access to sequencing infrastructure. Here, we adapt random forest models for single nucleotide polymorphism (SNP) polishing developed by Sanderson and colleagues (2020. High precision Neisseria gonorrhoeae variant and antimicrobial resistance calling from metagenomic nanopore sequencing. Genome Res. 30(9):1354–1363) to estimate divergence and effective reproduction numbers (R_e) of two methicillin-resistant Staphylococcus aureus (MRSA) outbreaks from remote communities in Far North Queensland and Papua New Guinea (PNG; n = 159). Successive barcoded panels of S. aureus isolates (2 × 12 per MinION) sequenced at low coverage (>5× to 10×) provided sufficient data to accurately infer genotypes with high recall when compared with Illumina references. Random forest models achieved high resolution on ST93 outbreak sequence types (>90% accuracy and precision) and enabled phylodynamic inference of epidemiological parameters using birth–death skyline models. Our method reproduced phylogenetic topology, origin of the outbreaks, and indications of epidemic growth (R_e > 1). Nextflow pipelines implement SNP polisher training, evaluation, and outbreak alignments, enabling reconstruction of within-lineage transmission dynamics for infection control of bacterial disease outbreaks on portable nanopore platforms. Our study shows that nanopore technology can be used for bacterial outbreak reconstruction at competitive costs, providing opportunities for infection control in hospitals and communities without access to sequencing infrastructure, such as in remote northern Australia and PNG.     

Evidence for non-ribosomal peptide synthetase production of cereulide (the emetic toxin) in Bacillus cereus

Little is known about the process whereby the emetic toxin (or cereulide) of Bacillus cereus is produced. Two cereulide-producing strains of B. cereus were cloned and sequenced following polymerase chain reaction (PCR) amplification with primers that were specific for conserved regions of non-ribosomal peptide synthetase (NRPS) genes. The cloned regions of the B. cereus strains were highly homologous to conserved regions of other peptide synthetase nucleotide sequences. Primers were designed for two variable regions of the NRPS gene sequence to ensure specificity for the emetic strains. A total of 86 B. cereus strains of known emetic or non-emetic activity were screened using these primers. All of the emetic strains (n=30) displayed a 188 bp band following amplification and gel electrophoresis. We have developed an improved method of identifying emetic strains of B. cereus and provided evidence that cereulide is produced by peptide synthetases.     

A web server to locate periodicities in a sequence

Summary : FT is a tool written in C++, which implements the Fourier analysis method to locate periodicities in aminoacid or DNA sequences. It is provided for free public use on a WWW server with a Java interface. Availability : The server address is http://o2.db. uoa.gr/FT Contact : shamodr@atlas.uoa.gr      

Peptides of Presenilin-1 Bind the Amyloid Precursor Protein Ectodomain and Offer a Novel and Specific Therapeutic Approach to Reduce ?-Amyloid in Alzheimer’s Disease

β-Amyloid (Aβ) accumulation in the brain is widely accepted to be critical to the development of Alzheimer’s disease (AD). Current efforts at reducing toxic Aβ40 or 42 have largely focused on modulating γ-secretase activity to produce shorter, less toxic Aβ, while attempting to spare other secretase functions. In this paper we provide data that offer the potential for a new approach for the treatment of AD. The method is based on our previous findings that the production of Aβ from the interaction between the β-amyloid precursor protein (APP) and Presenilin (PS), as part of the γ-secretase complex, in cell culture is largely inhibited if the entire water-soluble NH₂-terminal domain of PS is first added to the culture. Here we demonstrate that two small, non-overlapping water-soluble peptides from the PS-1 NH₂-terminal domain can substantially and specifically inhibit the production of total Aβ as well as Aβ40 and 42 in vitro and in vivo in the brains of APP transgenic mice. These results suggest that the inhibitory activity of the entire amino terminal domain of PS-1 on Aβ production is largely focused in a few smaller sequences within that domain. Using biolayer interferometry and confocal microscopy we provide evidence that peptides effective in reducing Aβ give a strong, specific and biologically relevant binding with the purified ectodomain of APP 695. Finally, we demonstrate that the reduction of Aβ by the peptides does not affect the catalytic activities of β- or γ-secretase, or the level of APP. P4 and P8 are the first reported protein site-specific small peptides to reduce Aβ production in model systems of AD. These peptides and their derivatives offer new potential drug candidates for the treatment of AD.     

Control of subterranean termites (Isoptera: Rhinotermitidae) infesting power poles

A trial was conducted to determine the efficacy of termiticidal dusts (arsenic trioxide, triflumuron, and Metarhizium anisopliae), a timber fumigant (dazomet) and liquid termiticides (bifenthrin, chlorfenapyr, chlorpyrifos, fipronil, and imidacloprid) for controlling subterranean termites (Isoptera: Rhinotermitidae) infesting in-service power poles in New South Wales, Australia. Dusts were applied to parts of the pole where termites were present. Fumigant was inserted into holes drilled into the base of the pole. Liquid termiticides were mixed with soil around the base of the pole and injected into internal voids if present. Poles were inspected for up to 5 yr, and the time taken for reinfestation to occur was recorded. Before the start of the trial, the major Australian pole owners were surveyed to obtain an estimate of the annual national cost of termite infestation to the power supply industry. The annual costs of termite treatment and replacing damaged poles were estimated at AU$2 million and AU$13 million, respectively. Infestation rates were lower for all treatments compared with controls within the first 12 mo of the study. Dazomet, arsenic trioxide, fipronil, and chlorpyrifos were the most efficacious treatments. Efficacy was positively related to the amount of termiticide applied and negatively related to the infestation severity but was unaffected by geographical location. Survival curves were calculated of the time elapsed before the recurrence of termite infestations (survival absence of reinfestation). Survival was highest for poles treated with liquid termiticides.     

Experiments on nutrient limitation in bottles

A simple model is used to illustrate the character of production,within an incubation bottle subject to addition of a potentiallylimiting nutrient, over time periods long relative to the algaldynamics (1–10 days). Grazing by microheterotrophs significantlyaffects algal and nutrient dynamics, and production reflectsthe integration over time of grazing and nutrient-regulatedgrowth. Greater production is found with increased nutrient,but this increase continues into the region of luxuriant nutrient.Increased production per se cannot be used to determine whethera nutrient is limiting.