Sulfur Cycling as a Viable Metabolism under Simulated Noachian/Hesperian Chemistries

Water present on the surface of early Mars (>3.0 Ga) may have been habitable. Characterising analogue environments and investigating the aspects of their microbiome best suited for growth under simulated martian chemical conditions is key to understanding potential habitability. Experiments were conducted to investigate the viability of microbes from a Mars analogue environment, Colour Peak Springs (Axel Heiberg Island, Canadian High Arctic), under simulated martian chemistries. The fluid was designed to emulate waters thought to be typical of the late Noachian, in combination with regolith simulant material based on two distinct martian geologies. These experiments were performed with a microbial community from Colour Peak Springs sediment. The impact on the microbes was assessed by cell counting and 16S rRNA gene amplicon sequencing. Changes in fluid chemistries were tested using ICP-OES. Both chemistries were shown to be habitable, with growth in both chemistries. Microbial communities exhibited distinct growth dynamics and taxonomic composition, comprised of sulfur-cycling bacteria, represented by either sulfate-reducing or sulfur-oxidising bacteria, and additional heterotrophic halophiles. Our data support the identification of Colour Peak Springs as an analogue for former martian environments, with a specific subsection of the biota able to survive under more accurate proxies for martian chemistries.

Microbes from Brine Systems with Fluctuating Salinity Can Thrive under Simulated Martian Chemical Conditions

The waters that were present on early Mars may have been habitable. Characterising environments analogous to these waters and investigating the viability of their microbes under simulated martian chemical conditions is key to developing hypotheses on this habitability and potential biosignature formation. In this study, we examined the viability of microbes from the Anderton Brine Springs (United Kingdom) under simulated martian chemistries designed to simulate the chemical conditions of water that may have existed during the Hesperian. Associated changes in the fluid chemistries were also tested using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The tested Hesperian fluid chemistries were shown to be habitable, supporting the growth of all of the Anderton Brine Spring isolates. However, inter and intra-generic variation was observed both in the ability of the isolates to tolerate more concentrated fluids and in their impact on the fluid chemistry. Therefore, whilst this study shows microbes from fluctuating brines can survive and grow in simulated martian water chemistry, further investigations are required to further define the potential habitability under past martian conditions.

Is the T-ligament a ligament? A histological study in equine cadaver forelimbs

Foot pain is a frequent cause of lameness in horses and can involve multiple structures within the hoof. The T-ligament (an anatomical structure connecting the synovium of the distal interphalangeal joint, the digital flexor tendon sheath and the navicular bursa) is poorly described. Five pairs of equine cadaver distal forelimbs were collected from a slaughterhouse. Sagittal sections (medial, middle and lateral) were obtained and processed with Haematoxylin Eosin Safran, Unna's Orcein, and Picrosirius red stains. Histological assessment revealed that the T-ligament was covered by the surrounding synovia of the distal interphalangeal joint, the digital flexor tendon sheath and the navicular bursa. Its collagen content was lower (30.01%±10.15) than that of the collateral sesamoidean ligament (89.48%±5.8; P = .0008) and the middle phalanx (85.72%±3.67; P = .0008). Under polarized light microscopy, it showed a slight heterogeneous pattern of birefringence, with angle-related changes. Elastic fibres were more numerous (21.76%±8.72) than in the collateral sesamoidean ligament (0.28%±0.45), or deep digital flexor tendon (0.04%±0.02); and were more densely packed. Mean cell count was higher for the T-ligament than for other tissues (P = .0007). Blood vessels were identified in the T-ligament and were penetrating the deep digital flexor tendon (8/10 limbs, 5/5 horses). In conclusion, the T-ligament looked like a vinculum for the deep digital flexor tendon, with a central elastic core, surrounding loose connective tissue and blood vessels. It is not a ligament. Its clinical relevance still needs to be determined.

BEVA primary care clinical guidelines: Analgesia

Primary care guidelines provide a reference point to guide clinicians based on a systematic review of the literature, contextualised by expert clinical opinion. These guidelines develop a modification of the GRADE framework for assessment of research evidence (vetGRADE) and applied this to a range of clinical scenarios regarding use of analgesic agents. Key guidelines produced by the panel included recommendations that horses undergoing routine castration should receive intratesticular local anaesthesia irrespective of methods adopted and that horses should receive NSAIDs prior to surgery (overall certainty levels high). Butorphanol and buprenorphine should not be considered appropriate as sole analgesic for such procedures (high certainty). The panel recommend the continuation of analgesia for 3 days following castration (moderate certainty) and conclude that phenylbutazone provided superior analgesia to meloxicam and firocoxib for hoof pain/laminitis (moderate certainty), but that enhanced efficacy has not been demonstrated for joint pain. In horses with colic, flunixin and firocoxib are considered to provide more effective analgesia than meloxicam or phenylbutazone (moderate certainty). Given the risk of adverse events of all classes of analgesic, these agents should be used only under the control of a veterinary surgeon who has fully evaluated a horse and developed a therapeutic, analgesic plan that includes ongoing monitoring for such adverse events such as the development of right dorsal colitis with all classes of NSAID and spontaneous locomotor activity and potentially ileus with opiates. Finally, the panel call for the development of a single properly validated composite pain score for horses to allow accurate comparisons between medications in a robust manner.

Ex Vivo Assessment of an Ultrasound-Guided Injection Technique of the Navicular Bursa in the Horse

Synovitis of the navicular bursa is common in performance horses. The objective of this study was to describe an ultrasound-guided technique to inject a distended navicular bursa and to evaluate its feasibility for use by a clinician not trained in the technique. Twenty distal limbs of horses of various breeds and sizes were used. To produce synovial distension, the navicular bursa of each limb was injected with contrast medium using a lateral approach and radiography was performed to confirm that the contrast medium was distending the bursa. The digit was positioned with the distal interphalangeal joint in hyperextension. A microconvex ultrasound probe was placed in the hollow of the pastern, palmar to the middle phalanx and the region was assessed in a transverse plane slightly oblique to the horizontal plane. The ultrasound probe was rotated to visualize both the lateral and medial recesses and to select which side was more distended to inject. A 21G 0.8 × 50 mm needle was inserted abaxially to the probe in the plane of the ultrasound beam into the proximal recess of this navicular bursa and a methylene blue solution was injected. Following injection, dissection was performed to assess whether the navicular bursa had been successfully injected. This ultrasound-guided technique was reliably performed with a success rate of 68%. The success of injection is influenced by hyperextension of the foot, quality of ultrasound images and degree of distension of the bursa.

Portable mass spectrometry for measurement of anaesthetic agents and methane in respiratory gases

Monitoring the composition of gases breathed by anaesthetised patients requires measurement methods with fast responses, high accuracy and good reliability. There is also an increasing demand for systems to be able to monitor more than one target analyte simultaneously, but some gas analysers can be sensitive to the presence of methane gas in exhaled breath, consequently leading to inaccurate measurements of the anaesthetic agent. This study investigated the feasibility of employing portable quadrupole mass spectrometry to monitor volatile anaesthetic agents (halothane, isoflurane and sevoflurane), methane accumulation in anaesthetic rebreathing systems, and inspired and exhaled carbon dioxide and oxygen concentrations during equine anaesthesia in a clinical setting. The volatile anaesthetic agents were easily measurable and methane was detectable. The instrument had an advantage over short wavelength infrared absorption spectrometry analysers because it could monitor anaesthetic agents and other respiratory gases simultaneously and at extremely low concentrations, although further optimisation is required.

Prospective evaluation of postoperative pain in cats undergoing ovariohysterectomy by a midline or flank approach

Twenty entire female cats were randomly assigned to two groups of 10; the cats in one group underwent ovariohysterectomy by a midline approach and the cats in the other group by a flank approach. Cats were assessed for signs of pain and scores were assigned pre- and postoperatively. There was a tendency for the cats neutered by a flank approach to be in more pain postoperatively (P=0.05). The final pain score for cats in either group was equal to or lower than their baseline score.

Aboriginal health: a sick minority skews statistics

Overall morbidity and mortality rates are higher among Aboriginal people than in the general Australian population. It is unclear, however, whether this is because of general poor health or a minority with very high levels of disease within a reasonably healthy Aboriginal community. At Cherbourg Community, almost all health care is given by the hospital. All visits to the casualty/outpatient departments at the hospital have been recorded since 1993. These data have been analysed to find the patterns of visiting by person, by diagnosis and by year. Over the 5 years with complete data, most people made less than five visits per year (low visit group) to the hospital ambulatory clinic, but at the other extreme, approximately 14% of people made 50% of the visits (high visit group). People who made many visits in 1 year made approximately three times as many visits as the low visit group in other years. When the high and low visit groups were compared, the high visit group was more likely to be female and to come for problems related to infection, but were less likely to come with injuries or accidents. The age distribution was similar in both groups. If the number of visits to a health service is an indicator of health, then most Aboriginal people at Cherbourg have reasonable health, but a sizeable minority have health problems that extend over several years. This group skews the overall statistics of Aboriginal health and should be targeted for extra attention.

Ambulatory services in an aboriginal community and a west Queensland rural area

The aim of this study was to compare the incidence/prevalence of diseases in persons attending for ambulatory care at a Queensland Aboriginal community and a farming area in western Queensland. Data were analysed for attendances for disease management from 1 May 1994 to 31 April 1995 at Cherbourg Hospital and from 1 March 1995 to 28 February 1996 at Alpha Hospital. Over these periods the hospitals and associated clinics were the only local ambulatory services available to each community. The numbers of visits for management of disease were 6.0 per person per year at Cherbourg and 4.3 per person per year at Alpha. At each location 78% of the population visited the service for disease management. At Cherbourg, the commonest diagnoses were skin diseases, mainly associated with scabies, accidents and injuries, and respiratory diseases. At Alpha the commonest problems were accidents and injuries, and respiratory disorders, followed by musculoskeletal, skin and CNS disorders. The rate of diabetes was higher in the Cherbourg group, but involved only 5% of the population and was thus not a major cause for the use of health services. The rate of visits for cardiovascular disease at Alpha and Cherbourg were similar, but the percentage of persons involved was smaller at Cherbourg. Accidents and injuries, and respiratory diseases were common in both locations. Skin disease, mainly due to scabies, was a major problem in the Aboriginal community and led to many admissions. Many visits involved potentially preventable diseases.

Primary health care for Indo-Chinese children in Australia

This study reports the detailed analysis of 61 consecutive presentations by recent immigrants from Indo-China to the Casualty Department of a modern Australian Children's Hospital. The parents/guardians were interviewed either in the Casualty Department or in their homes. Indo-Chinese children coming to a Casualty Department manifested the same age distribution and spectrum of illnesses that is seen in the general Australian paediatric population. However, significantly fewer presentations to hospital occurred due to accidents/trauma when the group was compared with the general population attending the Casualty Department. Only 21% of the Vietnamese and Cambodian families can communicate satisfactorily with hospital staff without interpreter help. Fifty-one per cent of parents reported that they did not have enough English for a medical interview without an interpreter. Twenty-eight per cent did not have enough English to communicate at all. Parents of Vietnamese children reported that on occasions they had not sought medical care for their children because of language difficulties. Many families do not know that an Interpreter Service is available, and many believe that access to such a service is available only through a doctor. Many of these children also use traditional Chinese remedies in the context of their contemporary Australian lives. We have found no evidence that this practice causes late presentation with deleterious effects, or any evidence that it compromises modern 'Western' treatment.

Refeeding after acute gastroenteritis: a controlled study

Children admitted with acute gastroenteritis were managed with clear fluids and then given either the standard graduated feeding regimen or an abrupt reintroduction of normal feeds. The rapid refeeding group lost less weight, went home sooner, and had no increase in complication rate. Rapid refeeding is a reasonable option in the management of acute gastroenteritis.

Open-ended tympanometric screening: A new concept

We introduce the concept of open-ended, successive-day, tympanometric screening. In impedance screening of children for middle ear disorders, there is a serious risk of over-referral if decisions are made on the basis of a single tympanogram. Serial tympanometric studies of Australian aboriginal children show that, whereas the type B tympanogram is usually stable, type A and type C patterns are prone to vary from day to day, inviting inappropriate referral decisions unless the classifications are confirmed by tests on successive days.