Phasmarhabditis hermaphrodita is a parasitic nematode of terrestrial gastropods that has been formulated into a biological control agent for farmers and gardeners to kill slugs and snails. In order to locate slugs it is attracted to mucus, faeces and volatile cues; however, there is no information about whether these nematodes are attracted to snail cues. It is also unknown how wild isolates of P. hermaphrodita or different Phasmarhabditis species behave when exposed to gastropod cues. Therefore, we investigated whether P. hermaphrodita (commercial and wild isolated strains), P. neopapillosa and P. californica were attracted to mucus from several common snail species (Cepaea nemoralis, Cepaea hortensis, Arianta arbustorum and Cornu aspersum). We also examined whether snails (C. aspersum) collected from different locations around the UK differed in their attractiveness to wild isolates of P. hermaphrodita. Furthermore, we also investigated what properties of snail mucus the nematodes were attracted to, including hyaluronic acid and metal salts (FeSO4, ZnSO4, CuSO4 and MgSO4). We found that the commercial strain of P. hermaphrodita responded poorly to snail mucus compared to wild isolated strains, and C. aspersum collected from different parts of the UK differed in their attractiveness to the nematodes. We found that Phasmarhabditis nematodes were weakly attracted to all metals tested but were strongly attracted to hyaluronic acid. In a final experiment we also showed that pharmacological manipulation of cyclic guanosine monophosphate (cGMP) increased chemoattraction to snail mucus, suggesting that the protein kinase EGL-4 may be responsible for Phasmarhabditis sp. chemoattraction.

In France, the Public Health Code was amended in 2004, and now allows dentists to treat facial tissues adjacent to the mouth: and hence, they can now bridge the gap between maxillary sinuses and the mouth area by performing hyaluronic acid injection procedures in the perio-buccal soft tissues.

Accordingly, the National Council of the Order of Dental Surgeons authorizes the practice of hyaluronic acid injection for therapeutic use.

In this article, we will define the legal framework for which we will be held liable as it pertains to hyaluronic acid injection procedures.

After explaining the physico-chemical properties of hyaluronic acid, we will study the mechanisms of ageing, the architecture of the face and various methods of injection.

We will look at the indications and counter indications for the use of hyaluronic acid injection, particularly in terms of its therapeutic usefulness for rehabilitating soft tissue when transitioning from a maxillary full-arch prosthesis to an implant born bridge.

Hyaluronic acid makes it possible to offset the lack of buccal margin of the resin-based removable prosthesis.

The ultrastructural study of rare cells within their niche in situ is very difficult. We have developed a method for locating individual transplanted cells and simultaneously identifying and analyzing the molecules and cellular phenotypes surrounding them in situ using transmission electron microscopy. This innovative method involves triple immunogold labeling combined with serial ultrathin sectioning. We demonstrate the validity of this approach by examining the niche of individual transplanted cells from a population highly enriched for hemopoietic stem cells and the ultrastructural expression of two key stem cell regulatory molecules, hyaluronic acid and osteopontin. In addition, we describe the phenotypes of the surrounding cells.

Many neurons and their synapses are enwrapped in a brain-specific form of the extracellular matrix (ECM), the so-called perineuronal net (PNN). It forms late in the postnatal development around the time when synaptic contacts are stabilized. It is made of glycoproteins and proteoglycans of glial as well as neuronal origin. The major organizing polysaccharide of brain extracellular space is the polymeric carbohydrate hyaluronic acid (HA). It forms the backbone of a meshwork consisting of CNS proteoglycans such as the lectican family of chondroitin sulphate proteoglycans (CSPG). This family comprises four abundant components of brain ECM: aggrecan and versican as broadly expressed CSPGs and neurocan and brevican as nervous-system-specific family members. In this review, we intend to focus on the specific role of the HA-based ECM in synapse development and function.

Objectives: We studied the experimental use of Seprafilm, a sheet-like filmform of hyaluronic acid, in the repair of subtotal perforations of the tympanic membrane (TM), and the durability of such repairs.

Method: The research was conducted on 42 Sprague–Dawley rats. Right TMs of all rats were subtotally and thermally perforated in the same fashion. Seprafilm was applied to the perforated TMs of the 21 rats comprising the experiment group. The perforated TMs of the remaining 21rats, the control group, were left to heal spontaneously.

Results: The mean healing times were recorded as 7.8 ± 0.6 days for the Seprafilm group and 14.9 ± 1.1 days for the control group (p < 0.001).

Conclusions: These results suggest that Seprafilm may be a possible first choice (before thedecision to operate) in subtotal perforations, considering its easy application and patient follow-up.

We studied the extent to which intra-articular hyaluronic acid (HA) administered to horses with experimentally induced synovitis in the third middle carpal joint altered cartilage proteoglycans (PGs) and the biomechanical properties of the third carpal bone. Intra-articular HA (Hylartin-V®) was administered to the middle carpal joints of healthy horses before and after the induction of synovitis by Escherichia coli lipopolysaccharide (LPS). Two groups of horses received intra-articular HA only, with evaluation 2 and 6 weeks later (group 2 and group 4). Two other groups (group 1 and group 3) received LPS followed by intra-articular HA and evaluation 2 and 6 weeks later. Ex vivo third carpal bone cartilage PG synthesis was measured by 35SO4 incorporation and third carpal bone cartilage PG content was determined by an assay for glucuronic acid. Biomechanical properties were measured by indentation testing. At the 2-week evaluation, HA did not ablate the quantitative reduction in PG synthesis and PG content in animals with experimental synovitis. However, by 6 weeks, there was a significant rebound effect in that PG synthesis and PG content were elevated in horses with experimental synovitis that had received intra-articular HA, compared with horses that had received HA only for that period of time. There were also alterations in the gel filtration profiles of newly synthesized PGs on Sepharose CL-2B among the groups. However, there were no de novo PG species associated with any of the treatments. Furthermore, we found that the biomechanical properties of third carpal bone cartilage were not altered in any of the groups. These studies showed that intra-articular HA administered to horses with experimentally induced synovitis did not provide short-term (i.e. 2-week) benefit to third carpal bone cartilage PG synthesis. However, a long-term benefit of intra-articular HA may occur after the acute effects of synovitis on PG synthesis and PG content subside.

Conjunctivitis lignosa, a rare affliction of the conjunctiva, is sometimes associated with other disturbances. We present two children with concurrent conjunctivitis lignosa and ear involvement. In these two cases, there were histopathologically verified ligneous changes of the middle ears.

Routine haematoxylin and eosin, van Gieson, periodic acid-Schiff (PAS) and alcian blue staining of specimens from the eyes and middle ears revealed findings typical for ligneous conjunctivitis. In addition, new histochemical and immunohistochemical studies for glycosaminoglycans on specimens from the eyes and middle ears showed that the accumulations of the amorphous, cell-deficient material stained strongly but heterogeneously for hyaluronic acid and weakly but uniformly for keratin sulphate. The staining for other glycosaminoglycans, e.g. chondroitin-4-sulphate and dermatan sulphate was confined to vessels and areas rich in collagen fibres and fibroblasts.

In patients with conjunctivitis lignosa, the ear involvement may remain undiagnosed due to its resemblance to secretory otitis media with effusion. Since isolated ear involvement may occur, we advocate biopsies for routine haematoxylin and eosin, and specific staining for hyaluronic acid and keratin sulphate, also in children with protracted, refractory otitis media with atypical effusion.

Hyaluronic acid has been proposed as a lubricant for improving the outcome of cochlear implant surgery. We describe a method which includes coating the electrodes with a thin layer of hyaluronic acid as well as using a droplet of the lubricant on the cochleostomy to provide additional magnification, like a lens, that facilitates the insertion of the electrode array. The use of hyaluronic acid reduces trauma to the cochlea and avoids contaminating perilymph by blood or by saline used during the operation. It is an efficacious and reliable method for cochlear implant surgery.

The proteinase inhibitor inter-α trypsin inhibitor (ITI) is a blood-derived protein necessary for normal female fertility. Absence of ITI leads to ovulation of naked oocytes that cannot fertilise. ITI consists of two heavy chains (ITI-HC) and bikunin linked by a chrondroitin sulphate. By binding to hyaluronate, ITI-HC stabilises the extracellular matrix, but ITI-HC also binds to proteoglycans in follicular fluid. In vivo concentrations of ITI components in preovulatory follicular fluid, free as well as bound to hyaluronate or proteoglycan, are unknown. In order to quantify these components, 58 follicular fluids and 13 blood samples were collected in connection with in vitro fertilisation and embryo transfer treatment of 13 women. Quantitation of glycosaminoglycan-bound ITI-HC was performed after separation from free ITI in agarose gel. ITI components were determined by immunoelectrophoresis and hyaluronate by an ELISA method. The follicular fluid concentration of ITI was on average 70% of that in plasma and the concentration of hyaluronate remained low despite follicular production, suggesting that the production of hyaluronate is the rate-limiting step in the formation of the extracellular matrix of the oocyte-cumulus complex. In follicular fluid, the concentration of free ITI-HC was higher than that of glycosaminoglycan-bound ITI-HC. Addition of exogeneous hyaluronate doubled the amount of hyaluronate-bound ITI-HC, further supporting the notion that ITI in follicular fluid is not rate-limiting for cumulus expansion in vivo.

When capacitated human sperm were treated with hyaluronic acid (HA) for 30 min prior to the addition of progesterone or solubilised human zonae pellucidae, there was a significant increase in the percentage of acrosome reactions. Progesterone treatment alone increased acrosome reactions from 10.5% to 21.8% and pretreatment with 100 µg/ml HA resulted in 33.0% acrosome reactions. With zonae pellucidae treatment alone the increase was from 9.0% to 23.5% and with HA pretreatment it was 48.8%. HA treatment alone had no direct effect on acrosome reactions, and the enhancing effect of HA was not removed when sperm were washed prior to the addition of either acrosome reaction agonist. Experiments with sperm 5 min after HA treatment demonstrated that enhancement of acrosome reactions was apparent as early as 1 min after addition of zonae and within 5 min after addition of progesterone. When sperm were pretreated with Fab fragments of anti-PH-20 IgG, then with HA and then with progesterone or zonae pellucidae, there was no enhancement of the acrosome reaction. Fab treatment did not induce acrosome reactions and did not interfere with the action of either agonist in the absence of HA. Sperm that were treated with HA had significantly higher intracellular calcium levels, and pretreatment with Fab reduced this increase to 42.7%. Addition of progesterone to HA-treated sperm was followed by another large increase in intracellular calcium, which was lower when sperm were pretreated with Fab. These results suggest that HA interacts with the PH-20 protein to increase basal levels of intracellular calcium and thereby potentiates the acrosome reaction. The data support the hypothesis that HA in the cumulus matrix may act to prime the fertilising sperm for induction of the acrosome reaction by constituents of the cumulus and/or zona pellucida.

The hyaluronic acid (HA)-rich extracellular matrix (ECM) of the cumulus oophorus is known to facilitate fertilisation. It has been suggested that HA may enhance fertilisation in a number of species, and in macaque sperm, HA has been shown to increase the number of acrosome reactions that follow sperm binding to the zona pellucida. In this study, we investigated the effects of HA on intracellular Ca2+ in capacitated cynomolgus macaque sperm. Fluorometry studies using the intracellular Ca2+ indicator Fluo-3 showed that addition of 100 μg/ml of HA induced a rapid increase in intracellular Ca2+. This Ca2+ increase (approximately 2–3 times above basal levels) was inhibited by preincubation of sperm with Fab fragments of anti-recombinant PH-20 IgG. The frequency of acrosome reactions in sperm exposed to HA was not above control levels. A synthetic gel was prepared with similar viscosity to the cumulus and with HA trapped in its matrix. Video imaging of individual sperm was used to demonstrate that capacitated sperm swimming into the HA gel had increased intracellular Ca2+ levels. Preincubation of sperm with Fab fragments of anti-PH-20 IgG inhibited the increased intracellular Ca2+ levels induced by the HA gel. Sperm in control gel (no HA) did not show increased intracellular Ca2+, while sperm in gel containing anti-PH-20 IgG showed increased Ca2+ (positive control). Sperm loaded with Fluo-3 were allowed to interact with cynomologus macaque cumulus masses, and sperm within the cumulus ECM clearly showed increased intracellular Ca2+ that was inhibited when sperm were preincubated in anti-PH-20 Fab. Fluorescein isothiocyanate (FITC)-HA was found to bind to sperm over the acrosomal region, corresponding to PH-20 localisation, and this binding could be inhibited by preincubation of sperm with anti-PH-20 fragments. The results of this study show that HA increases intracellular Ca2+ in macaque sperm through interaction with plasma membrane PH-20. We propose that HA binding to plasma membrane PH-20 induces an aggregation of receptors that in turn results in intracellular signalling. As a result, sperm have higher basal CA2+ levels and are more responsive to induction of the acrosome reaction after binding to the zona pellucida.

Hyaluronic acid (HA) is a polysaccharide preferably extracted from cockerel combs and used for medical purposes, mainly eye surgery. One way of increasing the production of HA from cockerels is to increase the size of the combs. The aim of this work was to study comb development and quantify direct and correlated responses for comb size at different ages and comb weight in two lines of White Leghorn selected for comb size at two different ages. Two lines were created, one selected for comb size at 16 weeks of age (CS16) (line E = early comb development) and the other for comb size at 29 weeks of age (CS29) (line A = adult comb size). There were between 500 and 800 birds of each line and generation and the lines had been selected for five generations. Cockerels in line E developed the combs at an earlier age and had smaller 29-week combs compared with the cockerels in line A. Genetic gain for the selection trait in generation five, measured in relation to line means in generation 1, was 58% in line E and 36% in line A. The corresponding correlated response for CS29 and comb weight (CW) in line E was 28% and 25% respectively, while for CS16 and CW in line A it was 46% and 35%. The results indicated that it is possible to increase cockerel comb size at both 16 and 29 weeks of age through selection.