A simple method for assessing muscle function in common marmosets

A novel method of assessing muscle function in the common marmoset was developed as part of a multidisciplinary long-term study. The method involved home cage presentation of a weight-pulling task. Over a 4–5 month period, 38 of 42 animals were successfully trained to displace weights of up to 920 g (mean 612±20 g). Performance, following initial training, was stable and independent of gender or body weight.

Avian and human receptor binding by hemagglutinins of influenza A viruses

An understanding of the structural determinants and molecular mechanisms involved in influenza A virus binding to human cell receptors is central to the identification of viruses that pose a pandemic threat. To date, only a limited number of viruses are known to have infected humans even sporadically, and this has recently included the virulent H5 and H7 avian viruses. We compare here the 3-dimensional structures of H5 and H7 hemagglutinins (HA) complexed with avian and human receptor analogues, to highlight regions within the receptor binding domains of these HAs that might prevent strong binding to the human receptor.

Studies into Using Manure in a Biorefinery Concept

Animal manure is an underutilized biomass resource containing a large amount of organic carbon that is often wasted with the existing manure disposal practices. A research project funded by the US Department of Energy explored the feasibility of using manure via the sugar platform in a biorefinery, converting the carbon from fiber to biochemicals. The results showed that (1) fiber was the major component of manure dry material making up approx 50%, 40%, and 36% of the dry dairy, swine, and poultry manure material, respectively; within dairy manure, more than 56% of the dry matter was in particles larger than 1.680 mm; (2) in addition to being a carbon source, manure could provide a variety of nutrient for fungi T. reesei and A. phoenicis to produce cellulase; (3) the hemicellulose component in the manure fiber could be readily converted to sugar through acid hydrolysis; while concentrated acid decrystallization treatment was most effective in manure cellulose hydrolysis; (4) purification and separation was necessary for further chemical conversion of the manure hydrolysate to polyols through hydrogenation; and (5) the manure utilization strategy studied in this work is currently not profitable.

H1 and H7 influenza haemagglutinin structures extend a structural classification of haemagglutinin subtypes

Comparing the structures of H3, H5 and H9 subtype haemagglutinins, we deduced a structural basis for including all 15 influenza subtypes in four clades. H3, H5 and H9 represent three of these clades; we now report the structure of an H7 HA as a representative of the fourth clade. We confirm the structure of the turn at the N-terminus of the conserved central alpha-helix of HA2, and the combination of ionisable residues near the "fusion peptide" as clade-specific features. We compare the structures of three H1 HAs with H5 HA in the same clade, to refine our previous classification and we confirm the division of the clades into two groups of two. We also show the roles of carbohydrate side chains in the esterase-fusion domain boundaries in the formation of clade-specific structural markers.

The Structure and Receptor Binding Properties of the 1918 Influenza Hemagglutinin

The 1918 influenza pandemic resulted in about 20 million deaths. This enormous impact, coupled with renewed interest in emerging infections, makes characterization of the virus involved a priority. Receptor binding, the initial event in virus infection, is a major determinant of virus transmissibility that, for influenza viruses, is mediated by the hemagglutinin (HA) membrane glycoprotein. We have determined the crystal structures of the HA from the 1918 virus and two closely related HAs in complex with receptor analogs. They explain how the 1918 HA, while retaining receptor binding site amino acids characteristic of an avian precursor HA, is able to bind human receptors and how, as a consequence, the virus was able to spread in the human population.

X-ray structures of H5 avian and H9 swine influenza virus hemagglutinins bound to avian and human receptor analogs

The three-dimensional structures of avian H5 and swine H9 influenza hemagglutinins (HAs) from viruses closely related to those that caused outbreaks of human disease in Hong Kong in 1997 and 1999 were determined bound to avian and human cell receptor analogs. Emerging influenza pandemics have been accompanied by the evolution of receptor-binding specificity from the preference of avian viruses for sialic acid receptors in alpha2,3 linkage to the preference of human viruses for alpha2,6 linkages. The four new structures show that HA binding sites specific for human receptors appear to be wider than those preferring avian receptors and how avian and human receptors are distinguished by atomic contacts at the glycosidic linkage. alpha2,3-Linked sialosides bind the avian HA in a trans conformation to form an alpha2,3 linkage-specific motif, made by the glycosidic oxygen and 4-OH of the penultimate galactose, that is complementary to the hydrogen-bonding capacity of Gln-226, an avian-specific residue. alpha2,6-Linked sialosides bind in a cis conformation, exposing the glycosidic oxygen to solution and nonpolar atoms of the receptor to Leu-226, a human-specific residue. The new structures are compared with previously reported crystal structures of HA/sialoside complexes of the H3 subtype that caused the 1968 Hong Kong Influenza virus pandemic and analyzed in relation to HA sequences of all 15 subtypes and to receptor affinity data to make clearer how receptor-binding sites of HAs from avian viruses evolve as the virus adapts to humans.

Biological consequences of multiple vaccine and pyridostigmine pretreatment in the guinea pig

An investigation of the possible interactions between combinations of vaccines and pyridostigmine bromide (PB) has been undertaken in the guinea pig. This study is part of a research programme funded by the UK Government to determine any effects of the pretreatment regimes given to UK Forces during the Persian Gulf conflict of 1990-1991. The study was designed to simulate PB administration and to model multiple vaccination protocols that were experienced by UK Forces, modelling a "worst case" situation in which all ten vaccines and PB were administered within a short period of time. Seven of the vaccines were health and hygiene (H+H) vaccines given to protect against endemic diseases and two vaccines to protect against the biological warfare agents anthrax and plague. In addition, pertussis vaccine was administered as an adjuvant to reduce the time to achieve immunity against anthrax. Four groups of eight animals were treated with 1/20th, 1/10th or 1/5th human doses of vaccines or vehicles, respectively. The PB or saline was delivered by implanted 28 day mini-osmotic pumps to achieve a mean red blood cell acetylcholinesterase (AChE) inhibition of around 30%. Body weight, temperature, immunological response, biochemical indices and spontaneous activity were monitored for 72 days. Although immunological responses to bacterial vaccines were observed, there were no remarkable findings in the parameters measured other than minor changes in body weight (4.9% decrease at the 1/5th human dose of vaccines) and temperature increases in response to vaccination. Animals in all groups remained generally healthy and active without visible adverse signs throughout the study. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.

Developmental trade-offs and life histories: strategic allocation of resources in caddis flies

Resource allocation trade-offs during development are potentially very important in the evolution of organism morphology and life-history strategy However, they have rarely been demonstrated empirically. To what extent the division of limited resources between growing organs is a consequence of particular developmental pathways or varies strategically in line with life-history predictions is unknown. It has been demonstrated in a number of holometabolous insects that altering the resources available at pupation changes the pattern of allocation to adult tissues, but this has not been examined in a life-history context. Using caddis flies (Trichoptera), we show here that the effect of depleted larval resources on the pattern of somatic and reproductive investment is not fixed but varies between species with different life-history patterns. In particular, we demonstrate that, in a long-lived species, thorax size is preserved, which contrasts with the pattern previously observed in a short-lived species. That the adult body can be differentially altered by the same resource depletion in the larvae demonstrates that the allocation of resources amongst body parts is not a consequence of fixed pathways during development. Rather, the allocation of resources during development can occur in a manner consistent with the minimization of the effects on adult fitness.

Structure of the hemagglutinin precursor cleavage site, a determinant of influenza pathogenicity and the origin of the labile conformation

The membrane fusion potential of influenza HA, like many viral membrane-fusion glycoproteins, is generated by proteolytic cleavage of a biosynthetic precursor. The three-dimensional structure of ectodomain of the precursor HA0 has been determined and compared with that of cleaved HA. The cleavage site is a prominent surface loop adjacent to a novel cavity; cleavage results in structural rearrangements in which the nonpolar amino acids near the new amino terminus bury ionizable residues in the cavity that are implicated in the low-pH-induced conformational change. Amino acid insertions at the cleavage site in HAs of virulent avian viruses and those of viruses isolated from the recent severe outbreak of influenza in humans in Hong Kong would extend this surface loop, facilitating intracellular cleavage.

Genomic structure and sequence of the Fugu rubripes glucose-6-phosphate dehydrogenase gene (G6PD)

To investigate the organization of the compact genome of the puffer fish Fugu rubripes at the level of an individual housekeeping gene, we have cloned and sequenced the glucose-6-phosphate dehydrogenase (G6PD) gene from this fish and compared it to the corresponding human gene. The intron/exon structure of the two genes is identical throughout the protein coding regions. The puffer fish gene is four times smaller than the human gene--the difference is accounted for by the fact that the puffer fish gene has smaller introns. Intron 2 is the largest intron in both species. We have constructed a molecular phylogeny for 10 G6PD protein sequences. The sequences fall in the expected arrangement based on established phylogenetic relationships, with the Plasmodium falciparum sequence the most widely diverged.

New glucose-6-phosphate dehydrogenase mutations associated with chronic anemia

We have identified the glucose-6-phosphate dehydrogenase mutations responsible for enzyme deficiency in nine individuals with chronic nonspherocytic hemolytic anemia. We found the variants Tokyo, Iowa, Shinshu, and Guadalajara in British subjects and Kobe in an Italian. In addition we have determined the variant Corum has the mutation 820 G-->A and have found in British subjects the mis-sense mutations 224 T-->C, 488 G-->A and 833 C-->T which have not been described before. Some, but not all, of the mutations involve amino acids located near putative substrate binding sites.

Carcinoma of the pharyngeal pouch

The condition of carcinoma arising in a pharyngeal pouch is rare. It has been described in relation to long standing pouches and in pouches previously treated by the Dohlman's operation. Three additional cases of carcinoma of the pharyngeal pouch are described.

Acinous cell carcinoma of the larynx

Acinous cell tumours of the larynx and trachea are extremely rare. A recent review of the literature has only found four reported cases. This short report describes such a patient and discusses her management in the light of previous articles. In view of its rarity in the laryngotracheal area and the uncertainty in the way in which the tumour should be managed, we thought the following case report and review of the literature would be of interest.

Papillary endothelial hyperplasia in the nose

Benign papillary endothelial hyperplasia is a very rare lesion of the nasal cavity; histologically, it may be mistaken for an angiosarcoma. An awareness of this and the ways in which it differs from angiosarcoma will prevent incorrect diagnosis and inappropriate treatment by surgery or radiotherapy. A case report of each condition involving the nasal cavity is presented.

Tracheostomy service for ITU patients

An account of experience of tracheostomy performed on patients in the intensive care unit situation is presented. Forty-seven operations were undertaken over a 5-year period and the advantages and disadvantages are discussed. The authors recommend tracheostomy under these circumstances as an acceptable alternative to the procedure performed in an operating theatre.

Neurofibromas of the paranasal sinuses

Two cases of neurofibroma of the paranasal sinuses are presented. The tumours presented as space-occupying lesions and were treated by local excision. Histologically one was a typical neurofibroma, whilst the other showed some features of a schwannoma. The patients show no evidence of tumour recurrence at 18 and 6 months respectively.

Cushing's syndrome due to the abuse of betamethasone nasal drops

Cushing's syndrome due to the abuse of Betamethasone nasal drops has not been described before. This report presents such a case and emphasises the care which one must take in prescribing topical steroids.

Antigenic and amino acid sequence analysis of the variants of H1N1 influenza virus in 1986

Since their reintroduction to human populations in 1977, influenza A viruses of the H1N1 subtype have undergone antigenic drift. Recently a distinct antigenic variant, A/Singapore/6/86, has been almost exclusively isolated internationally, and the antigenic properties and amino acid sequence of its haemagglutinin have been determined and compared with those of the haemagglutinins of other H1N1 viruses, in particular A/Chile/1/83. Fourteen amino acid sequence differences are detected between the HA1 components of these two viruses, ten of which are different from equivalent residues in the haemagglutinins of all H1N1 viruses isolated between 1982 and 1983, and seven of which are novel in the haemagglutinins of all H1N1 viruses sequenced to date. The results are discussed in relation to the three-dimensional structure of the haemagglutinin and the location of the previously defined antigenically important regions.

The relevance of physical signs in recurrent tonsillitis in children (a prospective study)

Tonsillar physical signs plus cervical lymphadenopathy are irrelevant factors in the assessment of children with recurrent tonsillitis. Tonsillar protrusion, but not size, is related to snoring.

A carbohydrate side chain on hemagglutinins of Hong Kong influenza viruses inhibits recognition by a monoclonal antibody

A single amino acid substitution, Asp-63 to Asn-63, was detected in the hemagglutinin of an antigenic variant of the 1968 Hong Kong (H3) influenza virus that was selected by growth of the wild-type virus in the presence of a monoclonal antibody. The mutation generates an oligosaccharide attachment site, Asn-Cys-Thr at residues 63-65, that is glycosylated. Immunoprecipitation experiments with extracts from variant virus-infected cells prepared in the presence or absence of tunicamycin, which inhibits glycosylation, demonstrate that addition of the new oligosaccharide side chain is required to prevent reaction with the monoclonal antibody. Similar experiments with the virus of the 1969 Hong Kong influenza epidemic, A/England/878/69, which also contains a hemagglutinin glycosylated at residue 63, support this conclusion and provide evidence for the epidemiological significance of carbohydrate-mediated modifications of hemagglutinin antigenicity.

Platelet lesion of collection

In the early stages of blood collection for transfusion, whole blood is subjected to trauma from the anticoagulant. The blood--anticoagulant mixture does not attain a pH at which platelets can remain functional (approximately pH 6.0) until about 25% of the unit has been collected. We have examined platelet ultrastructure and in vitro aggregation responses to adenosine diphosphate (ADP) and epinephrine (EPN), to assess the platelet trauma of collection into citrate-phosphate-dextrose. For comparison blood was collected by 2 methods: one was conventional (CC), the other metered anticoagulant into the blood as it was collected (MC). Platelets from CC blood showed disruption of organelles and depletion of the dense bodies, whereas platelets from MC blood showed no ultrastructural damage. In addition, biphasic aggregation in response to ADP or EPN was seen in MC platelets but not in CC platelets.

Studies on the quaternary structure of Escherichia coli pyruvate oxidase

Pyruvate oxidase is a peripheral membrane enzyme isolated from Escherichia coli. The enzyme catalyzes the oxidative decarboxylation of pyruvate to yield acetate plus CO2. The specific activity of the purified oxidase is stimulated 25-fold by lipids, and this lipid requirement has been the subject of previous studies. Since the enzyme is a tetramer at high protein concentrations (1 mg/ml) and is known to self-aggregate under certain conditions, the question arose as to whether the lipid stimulation observed in the steady state assay might be due to a change in the quaternary structure of the protein, either a dissociation or further association. This report is directed at determining the state of association of pyruvate oxidase under assay conditions by using fluorescence polarization. A photoreactive, nonspecific probe, 1-azidonaphthalene 5-sulfonate, was used to label the protein surface with an extrinsic fluorophore. It is concluded that under steady state assay conditions the oxidase remains tetrameric.