Traces, CSLBS Newsletter Winter 2023

With contributions from Matthew J. Smith, Lila O’Leary Chambers, and Celia E. Naylor

Ecology of the Invasive Red Alga Gracilaria salicornia (Rhodophyta) on O'ahu, Hawai'i

The red alga Gracilaria salicornia (C. Agardh) E. Y. Dawson was introduced intentionally to two reefs on O'ahu, Hawai'i, in the 1970s for experimental aquaculture for the agar industry. Some 30 yr later, this species has spread from the initial sites of introduction and is now competing with native marine flora and fauna. The goals of this study were to quantify various aspects of G. salicornia ecology in Hawai'i in an effort to develop control or eradication tools. Experimental plots were established to determine cover and biomass of G. salicornia per square meter and to determine the amount of time and person hours needed to remove G. salicornia from these plots. Substantial amounts of G. salicornia become dislodged from the reef during large wave events and periodically become deposited onto the beach in front of the Waikiki Aquarium. Algal beach wash biomass was quantified and positive relationships were established between swell height and the amount of algae that washed up onto the beach in this location. We then quantified the ability of G. salicornia vegetative fragments to regrow after desiccation to determine if algal biomass stranded on shore survives the tidal cycle until being washed back out on the reef at high tide. Gracilaria salicornia was remarkably resistant to temperature, salinity, and chemical treatments examined as possible in situ control options. Herbivore preference tests showed that a native Gracilaria species is consumed far more frequently than the alien congener. Finally, large-scale community volunteer efforts were organized to remove drifting G. salicornia fragments from the reef area in front of the Waikiki Aquarium. Over 20,000 kg of alien algal fragments were removed from this location in five 4-hr cleanup events. However, based on G. salicornia growth rates, ability to fragment, physical tolerance, and low herbivory, it is clear that a large-scale dedicated effort will be needed to control this invasive species on Waikiki's reefs

The management of hepatobiliary cystadenomas: lessons learned

AbstractBackgroundMucinous cystic neoplasms of the liver (hepatobiliary cystadenomas) are rare neoplastic lesions. Such cysts are often incorrectly diagnosed and managed, and carry a risk of malignancy. The objective of this study was to review the surgical experience with these lesions over 15 years.MethodsA retrospective chart review identified consecutive patients undergoing surgery for liver cystadenomas from 1997–2011. Clinical data were collected and summarized.ResultsThirteen patients (mean age 51 years, 12/13 females) with cysts 4.6–18.1cm were identified. Most cysts were located in the left lobe/centrally (11/12) and had septations (8/13). Mural nodularity was infrequent (3/13). Nine patients had liver resection/enucleation, whereas four had unroofing. Frozen section analysis had a high false‐negative rate (4/6). All patients had cystadenomas, of which two had foci of invasive carcinoma (cystadenocarcinoma) within mural nodules. There was no 90‐day mortality. All but one patient (myocardial infarction) were alive at a median follow‐up of 23.1 months. No patient with unroofing has developed malignancy to date.ConclusionsNon‐invasive hepatobiliary cystadenomas present as large central/left‐sided cysts in young or middle‐aged women. Associated malignancy was relatively uncommon and found within mural nodules. Intra‐operative frozen section analysis was ineffective at ruling out cystadenomas. Complete excision is recommended, but close follow‐up might be considered in patients with a prohibitive technical or medical risk, in the absence of nodularity on high‐quality imaging

A gene signature for post-infectious chronic fatigue syndrome

Background: At present, there are no clinically reliable disease markers for chronic fatigue syndrome. DNA chip microarray technology provides a method for examining the differential expression of mRNA from a large number of genes. Our hypothesis was that a gene expression signature, generated by microarray assays, could help identify genes which are dysregulated in patients with post-infectious CFS and so help identify biomarkers for the condition. Methods: Human genome-wide Affymetrix GeneChip arrays (39,000 transcripts derived from 33,000 gene sequences) were used to compare the levels of gene expression in the peripheral blood mononuclear cells of male patients with post-infectious chronic fatigue (n = 8) and male healthy control subjects (n = 7). Results: Patients and healthy subjects differed significantly in the level of expression of 366 genes. Analysis of the differentially expressed genes indicated functional implications in immune modulation, oxidative stress and apoptosis. Prototype biomarkers were identified on the basis of differential levels of gene expression and possible biological significance Conclusion: Differential expression of key genes identified in this study offer an insight into the possible mechanism of chronic fatigue following infection. The representative biomarkers identified in this research appear promising as potential biomarkers for diagnosis and treatment

Biomarker discovery and redundancy reduction towards classification using a multi-factorial MALDI-TOF MS T2DM mouse model dataset

Diabetes like many diseases and biological processes is not mono-causal. On the one hand multifactorial studies with complex experimental design are required for its comprehensive analysis. On the other hand, the data from these studies often include a substantial amount of redundancy such as proteins that are typically represented by a multitude of peptides. Coping simultaneously with both complexities (experimental and technological) makes data analysis a challenge for Bioinformatics

Clinical and biomechanical factors associated with falls and rheumatoid arthritis: Baseline cohort with longitudinal nested case-control study

OBJECTIVE: To identify the clinical and biomechanical characteristics associated with falls in people with RA. METHODS: A total of 436 people ≥60 years of age with RA completed a 1 year prospective survey of falls in the UK. At baseline, questionnaires recorded data including personal and medical history, pain and fatigue scores, health-related quality of life (HRQoL), physical activity and medication history. The occurrence of falls wasmonitored prospectively over 12 months by monthly self-reporting. A nested sample of 30 fallers (defined as the report of one or more falls in 12 months) and 30 non-fallers was evaluated to assess joint range of motion (ROM), muscle strength and gait parameters. Multivariate regression analyses were undertaken to determine variables associated with falling. RESULTS: Compared with non-fallers (n = 236), fallers (n = 200) were older (P = 0.05), less likely to be married (P = 0.03), had higher pain scores (P < 0.01), experienced more frequent dizziness (P < 0.01), were frequently taking psychotropic medications (P = 0.02) and reported lower HRQoL (P = 0.02). Among those who underwent gait laboratory assessments, compared with non-fallers, fallers showed a greater anteroposterior (AP; P = 0.03) and medial-lateral (ML) sway range (P = 0.02) and reduced isokinetic peak torque and isometric strength at 60° knee flexion (P = 0.03). Fallers also showed shorter stride length (P = 0.04), shorter double support time (P = 0.04) and reduced percentage time in swing phase (P = 0.02) and in knee range of motion through the gait cycle (P < 0.01). CONCLUSION: People with RA have distinct clinical and biomechanical characteristics that place them at increased risk of falling. Assessment for these factors may be important to offer more targeted rehabilitation interventions