Do astigmatid teeth matter: a tribological review of cheliceral chelae in co-occuring mites from UK beehives.

The dentition of the chelal moveable digit in cohabiting astigmatids from UK beehives (i.e., Carpoglyphus lactis (Linnaeus), Glycyphagus domesticus (DeGeer), and Tyrophagus putrescentiae (Schrank)) is characterised for the first time using quantitative tribological measures within a 2D mechanical model.

Transitional chelal digit patterns in saprophagous astigmatan mites.

Changes in the functional shape of astigmatan mite moveable digit profiles are examined to test if Tyrophagus putrescentiae (Acaridae) is a trophic intermediate between a typical micro-saprophagous carpoglyphid (Carpoglyphus lactis) and a common macro-saprophagous glycyphagid (Glycyphagus domesticus). Digit tip elongation in these mites is decoupled from the basic physics of optimising moveable digit inertia. Investment in the basal ramus/coronoid process compared to that for the moveable digit mastication length varies with feeding style.

Looking for future biological control agents: the comparative function of the deutosternal groove in mesostigmatid mites.

The physics of fluid laminar flow through an idealised deutosternum assembly is used for the first time to review predatory feeding designs over 72 different-sized example species from 16 mesostigmatid families in order to inform the finding of new biological control agents. Gnathosomal data are digitised from published sources. Relevant gnathosomal macro- and micro-features are compared and contrasted in detail which may subtly impact the control of channel- or 'pipe'-based transport of prey liquids around various gnathosomal locations.

Cheliceral chelal design in free-living astigmatid mites.

Cheliceral chelal design in free-living astigmatid mites (Arthropoda: Acari) is reviewed within a mechanical model. Trophic access (body size and cheliceral reach) and food morsel handling (chelal gape and estimated static adductive crushing force) are morphologically investigated. Forty-seven commonly occurring astigmatid mite species from 20 genera (covering the Acaridae, Aeroglyphidae, Carpoglyphidae, Chortoglyphidae, Glycyphagidae, Lardoglyphidae, Pyroglyphidae, Suidasiidae, and Winterschmidtiidae) are categorised into functional groups using heuristics.

Feeding design in free-living mesostigmatid chelicerae (Acari: Anactinotrichida).

A model based upon mechanics is used in a re-analysis of historical acarine morphological work augmented by an extra seven zoophagous mesostigmatid species. This review shows that predatory mesostigmatids do have cheliceral designs with clear rational purposes. Almost invariably within an overall body size class, the switch in predatory style from a worm-like prey feeding ('crushing/mashing' kill) functional group to a micro-arthropod feeding ('active prey cutting/slicing/slashing' kill) functional group is matched by: an increased cheliceral reach, a bigger chelal gape, a larger morphologically estimated chelal crunch force, and a drop in the adductive lever arm velocity ratio of the chela.

The gut epithelium from feeding to fasting in the predatory soil mite Pergamasus longicornis (Mesostigmata: Parasitidae): one tissue, two roles.

A review of acarine gut physiology based on published narratives dispersed over the historical international literature is given. Then, in an experimental study of the free-living predatory soil mite Pergamasus longicornis (Berlese), quantitative micro-anatomical changes in the gut epithelium are critically assessed from a temporal series of histological sections during and after feeding on larval dipteran prey. An argued functional synthesis based upon comparative kinetics is offered for verification in other mesostigmatids.

Gut contents, digestive half-lives and feeding state prediction in the soil predatory mite Pergamasus longicornis (Mesostigmata: Parasitidae).

Mid- and hind-gut lumenal changes are described in the free-living predatory soil mite Pergamasus longicornis (Berlese) from a time series of histological sections scored during and after feeding on fly larval prey. Three distinct types of tangible material are found in the lumen. Bayesian estimation of the change points in the states of the gut lumenal contents over time is made using a time-homogenous first order Markov model.

Modelling Malpighian tubule crystals within the predatory soil mite Pergamasus longicornis (Mesostigmata: Parasitidae).

The occurrence of refractive crystals (aka guanine) is characterised in the Malpighian tubules of the free-living predatory parasitiform soil mite Pergamasus longicornis (Berlese) from a temporal series of histological sections during and after feeding on larval dipteran prey. The tubular system behaves as a single uniform entity during digestion. Malpighian mechanisms are not the 'concentrative' mechanism sought for the early stasis in gut size during the second later phase of prey feeding.

Gut expansion and contraction in the predatory soil mite Pergamasus longicornis (Mesostigmata: Parasitidae): a stiff system.

Mite digestive processes are inferred from gut expansion and contraction time in the free-living predatory soil mite Pergamasus longicornis (Berlese), estimated using a temporal series of histological sections. Gut regions (bar the rectal vesicle) behave broadly in unison for rapid initial filling (ingestion half-life about 2-3 min; max 8 min), but behave heterogeneously when slowly emptying (digestion/egestion half-life from about 2-3 h; max 8.5 h).

TNF, LTA, HSPA1L and HLA-DR gene polymorphisms in HIV-positive patients with hypersensitivity to cotrimoxazole.

Aims: Sulfamethoxazole in combination with trimethoprim (cotrimoxazole) is used for prophylaxis and treatment of several opportunistic infections in HIV-infected patients. It is associated with a high incidence of hypersensitivity reactions, which is thought to have an immune basis. Genetic polymorphisms in MHC are known to predispose to hypersensitivity reactions to a structurally diverse group of drugs in HIV-positive patients.

Investigation into the multidimensional genetic basis of drug-induced Stevens-Johnson syndrome and toxic epidermal necrolysis.

Objective: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare severe blistering skin diseases, which are mainly caused by drugs. The two idiosyncratic conditions are distinguished on the basis of the degree of blistering, possibly representing diseases at different ends of the same spectrum. A genetic predisposition has been postulated.