Review of New Zealand Coastal Talitroids with description of three new genera (Crustacea, Amphipoda, Senticaudata).

A generic revision is provided for the New Zealand coastal talitroids, which reports two families, seven genera and thirteen species. Three new genera are described: Aotearorchestia gen. nov.; Subantarctorchestia gen. nov.; and Tatahipeke gen. nov. to accommodate seven known species, A. chathamensis (Hurley, 1956) comb. nov.; A. telluris (Spence Bate, 1862) comb. nov.; S. aucklandiae (Spence Bate, 1862) comb. nov.; S. bollonsi (Chilton, 1909) comb. nov.; Tatahipeke cookii (Filhol, 1885) comb. nov.; T. kirki (Hurley, 1956) comb. nov.; and T. tumida (G.M. Thomson, 1885) comb. nov. The three genera, Bellorchestia Serejo & Lowry, 2008, Protorchestia Bousfield 1982 and Transorchestia Bousfield, 1982 are revised to include additional information on morphology, growth stages and distributions for three New Zealand species: Bellorchestia quoyana (Milne Edwards, 1840); Transorchestia miranda (Chilton, 1916); and Trans. serrulata (Dana, 1852a). Lastly, a small commentary is given on four species of coastal talitroids where additional museum collections could not be located for study, B. spadix (Hurley, 1956), Pictonorchestia dentata (Filhol, 1885), Protorchestia campbelliana (Bousfield, 1964), and T. kirki (Hurley, 1956) gen. et comb. nov. A dichotomous key and pictorial field guide are provided to all New Zealand coastal talitroids.

Partial ceratohyoidectomy as surgical treatment for horses with temporohyoid osteoarthropathy: 10 cases (2010-2021).

OBJECTIVE: To describe outcomes of horses with temporohyoid osteoarthropathy (THO) treated with partial ceratohyoidectomy. ANIMALS: 10 client-owned horses. PROCEDURES: Medical records from 2 institutions were examined for records of horses with THO treated with partial ceratohyoidectomy between 2010 and 2021. History, signalment, clinical signs, diagnostics, medications, and surgery-related details were recorded. Horses with a minimum of 6 months follow-up were recruited for neurologic and imaging examinations in the hospital or field where radiography of the basihyoid-ceratohyoid articulation were performed along with CT, when available. RESULTS: 10 horses with THO were included (9 unilateral; 1 bilateral). Nine planned partial ceratohyoidectomies were performed in 8 horses, whereas 2 horses had preoperatively planned complete ceratohyoidectomies transitioned to partial ceratohyoidectomies during surgery due to intraoperative complications. Postoperative complications occurred mostly in transitioned surgeries (obstructed airway, tongue mobility issues, and incisional hemorrhage), whereas only 1 horse with a planned ceratohyoidectomy had postoperative complication of rhabdomyolysis. All complications resolved before hospital discharge. Neurologic signs improved in all 10 horses, with 2 showing complete resolution. Nine horses were available for radiographic follow-up, 6 of which also had head CT scans. A space between the ceratohyoid and basihyoid bones was measurable on radiography in all 9 horses, and was confirmed on CT. Three horses demonstrated proliferation of either ceratohyoid or basihyoid bones. The 9 horses with unilateral disease returned to previous work, and the horse with bilateral disease was retired. CLINICAL RELEVANCE: Partial ceratohyoidectomy is a surgical option for treatment of THO that provides similar clinical outcomes to published reports on ceratohyoidectomy.

A single faecal bile acid stool test demonstrates potential efficacy in replacing SeHCAT testing for bile acid diarrhoea in selected patients.

This study examines the validity of measuring faecal bile acids (FBA) in a single stool sample as a diagnostic tool for bile acid diarrhoea (BAD) by direct comparison to the 75selenium-homotaurocholic acid (SeHCAT) scan. A prospective observational study was undertaken. Patients with chronic diarrhoea (> 6 weeks) being investigated for potential BAD with SeHCAT scan provided stool samples for measurement of FBA, using an enzyme-linked immunosorbent assay. Patients were characterised into four groups: SeHCAT negative control group, post-cholecystectomy, idiopathic BAD and post-operative terminal ileal resected Crohn's disease. Stool samples were collected at baseline and 8-weeks post treatment to determine whether FBA measurement could be used to monitor therapeutic response. 113 patients had a stool sample to directly compare with their SeHCAT result. FBA concentrations (µmol/g) and interquartile ranges in patients in the control group (2.8; 1.6-4.2), BAD (3.6; 1.9-7.2) and post-cholecystectomy cohort 3.8 (2.3-6.8) were similar, but all were significantly lower (p < 0.001) compared to the Crohn's disease cohort (11.8; 10.1-16.2). FBA concentrations in patients with SeHCAT retention of < 15% (4.95; 2.6-10.5) and < 5% (9.9; 4.8-15.4) were significantly higher than those with a SeHCAT retention > 15% (2.6; 1.6-4.2); (p < 0.001 and p < 0.0001, respectively). The sensitivity and specificity using FBA cut-off of 1.6 µmol/g (using ≤ 15% SeHCAT retention as diagnostic of BAD) were 90% and 25% respectively. A single random stool sample may have potential use in diagnosing severe BAD or BAD in Crohn's patients. Larger studies are now needed to confirm the potential efficacy of this test to accurately diagnose BAD in the absence of SeHCAT testing.

Membrane transporter dimerization driven by differential lipid solvation energetics of dissociated and associated states.

Over two-thirds of integral membrane proteins of known structure assemble into oligomers. Yet, the forces that drive the association of these proteins remain to be delineated, as the lipid bilayer is a solvent environment that is both structurally and chemically complex. In this study, we reveal how the lipid solvent defines the dimerization equilibrium of the CLC-ec1 Cl-/H+ antiporter. Integrating experimental and computational approaches, we show that monomers associate to avoid a thinned-membrane defect formed by hydrophobic mismatch at their exposed dimerization interfaces. In this defect, lipids are strongly tilted and less densely packed than in the bulk, with a larger degree of entanglement between opposing leaflets and greater water penetration into the bilayer interior. Dimerization restores the membrane to a near-native state and therefore, appears to be driven by the larger free-energy cost of lipid solvation of the dissociated protomers. Supporting this theory, we demonstrate that addition of short-chain lipids strongly shifts the dimerization equilibrium toward the monomeric state, and show that the cause of this effect is that these lipids preferentially solvate the defect. Importantly, we show that this shift requires only minimal quantities of short-chain lipids, with no measurable impact on either the macroscopic physical state of the membrane or the protein's biological function. Based on these observations, we posit that free-energy differentials for local lipid solvation define membrane-protein association equilibria. With this, we argue that preferential lipid solvation is a plausible cellular mechanism for lipid regulation of oligomerization processes, as it can occur at low concentrations and does not require global changes in membrane properties.

A cell's outer membrane is made of molecules called lipids, which band together to form a flexible thin film, just two molecules thick. This membrane is dotted with proteins that transport materials in to and out of cells. Most of these membrane proteins join with other proteins to form structures known as oligomers. Except, how membrane-bound proteins assemble into oligomers ­ the physical forces driving these molecules to take shape ­ remains unclear. This is partly because the structural, physical and chemical properties of fat-like lipid membranes are radically different to the cell's watery interior. Consequently, the conditions under which membrane oligomers form are distinct from those surrounding proteins inside cells. Membrane proteins are also more difficult to study and characterize than water-soluble proteins inside the cell, and yet many therapeutic drugs such as antibiotics specifically target membrane proteins. Overall, our understanding of how the unique properties of lipid membranes affect the formation of protein structures embedded within, is lacking and warrants further investigation. Now, Chadda, Bernhardt et al. focused on one membrane protein, known as CLC, which tends to exist in pairs ­ or dimers. To understand why these proteins form dimers (a process called dimerization) Chadda, Bernhardt et al. first used computer simulations, and then validated the findings in experimental tests. These complementary approaches demonstrated that the main reason CLC proteins 'dimerize' lies in their interaction with the lipid membrane, and not the attraction of one protein to its partner. When CLC proteins are on their own, they deform the surrounding membrane and create structural defects that put the membrane under strain. But when two CLC proteins join as a dimer, this membrane strain disappears ­ making dimerization the more stable and energetically favorable option. Chadda, Bernhardt et al. also showed that with the addition of a few certain lipids, specifically smaller lipids, cell membranes become more tolerant of protein-induced structural changes. This might explain how cells could use various lipids to fine-tune the activity of membrane proteins by controlling how oligomers form. However, the theory needs to be examined further. Altogether, this work has provided fundamental insights into the physical forces shaping membrane-bound proteins, relevant to researchers studying cell biology and pharmacology alike.

Bile acid diarrhoea: Current and potential methods of diagnosis.

Chronic diarrhoea is common and mostly due to diarrhoea predominant irritable bowel syndrome. Diarrhoea predominant irritable bowel syndrome affects about 11% of the population; however, up to a third of these patients actually have bile acid diarrhoea. There are, therefore, more than one million sufferers of bile acid diarrhoea in the UK. Bile acid diarrhoea is caused by small bowel malabsorption of bile acids and the increased bile acids in the large intestine cause diarrhoea. Once diagnosed, the treatment of bile acid diarrhoea is simple and effective. Bile acid diarrhoea , however, is often not diagnosed because of a lack of easily available and reliable diagnostic methods. In the United Kingdom, the radiolabelled 23-seleno-25-homotaurocholic acid test is the gold-standard method of diagnosis. 23-seleno-25-homotaurocholic acid test, however, is expensive, inconvenient to the patient, involves radiation exposure and has limited availability. As such, a laboratory biomarker is desirable. This review briefly discusses the pathophysiology and management of bile acid diarrhoea and critically evaluates methods for its diagnosis, including serum 7α-hydroxy-4-cholesten-3-one, faecal bile acid measurement, serum fibroblast growth factor 19, urine-2-propanol, and the 14C-glycocholate breath and stool test.

Aegiochus gracilipes (Hansen, 1895) a senior synonym of Aegiochus tara Bruce, 2009 (Crustacea: Isopoda: Aegidae).

Aegiochus gracilipes Hansen, 1895 was described from a single immature specimen accompanied by three figures (Hansen 1895). Hansen (1916) subsequently reported the species without figures. Over the next 100 years A. gracilipes only appeared in the literature as a citation in larger review and cataloguing studies. Most significantly, Bruce (2009) transferred A. gracilipes from Aega Leach, 1815 to Aegiochus Bovallius, 1885, as part of a broader study redefining the morphological characters used to distinguish Aegiochus. To the present day A. gracilipes, described from the north-eastern Atlantic off the Outer Hebrides, Scotland, is known only from the original figures and its limited primary description.

New genera, species and records of Maeridae from Australian Waters: Austromaera, Ceradocus, Glossomaera, Hamimaera, Huonella gen. nov., Linguimaera and Maeraceterus gen. nov. (Crustacea: Amphipoda).

Thirty species of Maeridae are reported for Australian waters including the description of two new genera and nine new species. The new genus Huonella from southern Tasmanian seamounts is distinguished among the maerids by characters on the uropod 3, including elongation of both rami, inner ramus half the length of the outer ramus and outer ramus two articulate. The new genus Maeraceterus is establish for two new species, M. bramblensis from Western Australia and M. taaroa from Norfolk Island, which have a near transverse gnathopod 1 propodus palm and symmetrical male gnathopod 2. The new species Ceradocus baudini, Hamimaera thijsseni, Linguimaera boeckoides, L. daveyi, L. everardensis and L. mere are described here in. Additional distribution records are provided for eleven known Ceradocus and seven known Linguimaera, as well as three known maerids Austromaera mastersii (Haswell, 1879a), Glossomaera octodens (Sivaprakasam, 1969) and Hamimaera hamigera (Haswell, 1879b). Collections reported on here include material from Australia; Cocos (Keeling) and Christmas Islands, Indian Ocean; the Torres Strait; Papua New Guinea, Bismarck Sea and Norfolk Island, South Pacific. Keys to Ceradocus and Linguimaera sensu lato species in Australian waters are provided.

Mallacoota misool, a new species of Maeridae from West Papua (Crustacea: Peracarida: Amphipoda).

The new species Mallacoota misool is described from the West Macleur Gulf, West Papua. Mallacoota misool sp. nov. is exceptionally similar to the geographically close M. chandaniae Lowry & Springthorpe, 2005 known from the Gulf of Carpentaria in northern Australia and also reported from the South China Sea. Both species have a massive gnathopod 2 propodus defined by two large teeth. Mallacoota misool sp. nov. has the palm medial surface without a dense bunch of seta, which is present in M. chandaniae.

A review of the world Cyphocarididae with description of three new species (Crustacea, Amphipoda, Lysianassoidea).

The world Cyphocarididae are reviewed with new distribution records provided for eight taxa including three new species of Cyphocaris, C. ananke, C. nesoi and C. tartaros. Based on collections from Greenland a neotype is established for the type species Cyphocaris anonyx Boeck, 1871. An updated key to the 17 known world species of cyphocarids is provided.

Maeridae from the Indo-Pacific: Elasmopus, Leeuwinella gen. nov., Maeropsis, Pseudelasmopus and Quadrimaera (Amphipoda: Crustacea).

Twenty-two species of Maeridae including the new genus, Leeuwinella, and eight new species are described from Indo-Pacific waters. Leeuwinella mistakensis gen. et sp. nov. from southern Western Australia has dorsal carinae and serrate epimeral margins on pleonites 1-3 and mandibular palp article 3 concave; this significant combination of characters justifies erection of a new genus. Elasmopus coxacallus sp. nov., with a castelloserrate posterior margin of pereopod 7 presents a novel character for the genus, which contains over 100 described species. Elasmopus incomptus sp. nov. and E. norfolkensis sp. nov. are also described from Norfolk Island, South Pacific, while new distribution records are provided for E. gracilis Schellenberg, 1938, E. integer Myers, 1989, and E. molokai J.L. Barnard, 1970 from northwestern Australia, and E. souillacensis Appadoo & Myers, 2003, from the Kermadec Islands. New distribution records for Maeropsis griffini (Berents, 1983) from Bedout Island in Western Australia are the first of the species outside the Queensland type locality and new records of M. thetis (Lowry & Springthorpe, 2005) from mainland Australia to Tasmania and across the Tasman Sea extending its range. Pseudelasmopus walkerae sp. nov. is described from Norfolk Island, and is the second species recorded in the genus, previously known only from Mauritius. Lastly, three new Quadrimaera species, Q. gregoryi, Q. brownorum and Q. vallaris, along with eight known Quadrimaera species, are reported from various locations extending their distributions in the Indo-Pacific.

Endevouridae, a review with description of four new species (Crustacea, Amphipoda, Lysianassoidea).

The family Endevouridae is reviewed and four new species from the two genera, Endevoura and Ensayara, are described from Australian and Japanese waters. All species are diagnosed and the type species of Endevoura (End. mirabilis Chilton, 1921) and Ensayara (Ens. ramonella J.L. Barnard, 1964), respectively, are redescribed and illustrated. A key to the 19 known world species of Endevouridae is provided.

Three new species of Exampithoe from Australia and New Zealand (Ampithoidae: Amphipoda: Crustacea).

Three new species of Exampithoe are described from Australia and New Zealand. Material described here corroborates the peculiar mandibular palp variability, with either a two- or three- articulate palp reported for species within the genus Exampithoe compared to the absence of the mandibular palp in Melanesius. The Exampthoinae remain a Southern Hemisphere subfamily with nine described species.

New species and new records of Ampithoidae (Peracarida: Amphipoda) from Australian Waters.

Forty-eight species from the algal dwelling family Ampithoidae are recorded from five genera Ampithoe, Cymadusa, Paragrubia, Peramphithoe, and Plumithoe. New distribution records are provided for 18 species including five new records from Australian waters and an additional 18 new species are described. Twenty-two Ampithoe, 23 Cymadusa, six Paragrubia, two Peramphithoe, and one Plumithoe species are now known from Australian waters. The generic concepts of both Cymadusa and Paragrubia are revised to accommodate the new species diversity within the Ampithoidae. The new species are: Ampithoe mantissa; A. prolata; Cymadusa botulus; C. drummondae; C. euclidius; C. hadros; C. hallex; C. hentyana; C. jubata; C. lumanus; C. platys; C. priscileo; Paragrubia apoorei; P. cassini; P. dongara; P. dwyeri; P. springthorpei and Peramphithoe bungareei.