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Biomedical subjects

K Reilly

Publications and source records attributed to K Reilly.

At least 19 recordsLinked to original sources

Quantitative computer-assisted osteodensitometry in total hip arthroplasty.

Several factors can cause bone loss and fixation failure following total hip arthroplasty (THA), including polyethylene wear debris, implant micromotion and stress shielding. Various techniques have been used in an effort to detect bone density loss in vivo, all with varying success. Quantitative computed tomography (qCT)-assisted osteodensitometry has been shown to be useful in assessing the in vivo structural bone changes after THA. It has a high resolution, accuracy and reproducibility, thereby making it a useful tool for research purposes, and it is able to differentiate between cortical and cancellous bone structures and assess the bone/implant interface. This technique also provides valuable information about the pattern of stress shielding which occurs around the prosthesis and can show early bony changes, which may prove informative about the quality of implant fixation and surrounding bone adaptation. In conjunction with finite-element analysis, qCT is able to generate accurate patient-specific meshes on which to model implants and their effect on bone remodelling. This technology can be useful to predict bone remodelling and the quality of implant fixation using prostheses with different design and/or biomaterials. In the future, this tool could be used for pre-clinical validation of new implants before their introduction in the market-place.

Absorptiometry, Photon↗

Head and neck mucosal squamous cell carcinoma: results of palliative management.

OBJECTIVE: To document the outcome of patients deemed at initial diagnosis to be appropriate for palliative care. MATERIALS AND METHODS: Over a five-year period, all patients with head and neck mucosal squamous cell carcinoma (HNMSCC) were referred to one consultant surgeon, and data were collated retrospectively. RESULTS: Of 286 patients with HNMSCC, 60 (21 per cent) were deemed appropriate for palliative care at initial diagnosis. Their median survival was 154 days, with hypopharyngeal and oropharyngeal tumours forming a disproportional percentage of the initial diagnoses (p < 0.001). After initial assessment, 66 per cent of patients were discharged to their home, 17 per cent to hospice care and 17 per cent were transferred to other institutions. Including deaths during the initial admission, 29 per cent of patients did not return home after diagnosis. Palliative treatment included operative interventions in 35 per cent and radiotherapy in 43 per cent. Time spent in further hospital care averaged 47 days, and 47 per cent of patients eventually died in hospital. CONCLUSION: One in five patients presenting with HNMSCC were deemed appropriate for palliative care at initial presentation and survived less than six months after diagnosis. More than one-third required surgical intervention, and 29 per cent never returned home.

Aged↗

Autoradiographic localization of (125)i[Tyr(14)] nociceptin/orphanin FQ binding sites in macaque primate CNS.

Nociceptin/orphanin FQ (N/OFQ) is a recently identified neuropeptide that has been implicated in a multitude of CNS functions. These include nociception, feeding, cognition, locomotion, stress and neuroendocrine control. The endogenous receptor for this ligand is the nociceptin/orphanin FQ peptide (NOP) receptor. The distribution of NOP in rodent has been widely reported by the use of in situ hybridization, immunohistochemistry and autoradiographic radioligand binding but less is known of its localization in higher species. We have therefore sought to optimize and determine the distribution of (125)I[Tyr(14)]N/OFQ binding sites in macaque primate brain and spinal cord. Highest levels of binding were observed in neocortical areas, hippocampus, amygdala, caudate nucleus and putamen, medial thalamic nuclei and superficial laminae of the superior colliculus. These novel data present for the first time, the distribution of N/OFQ receptors in non-human primate CNS and, by comparison with localization in the rat, reveal that species differences may exist in the distribution of this neuropeptide receptor. These data have important implications regarding the roles of N/OFQ across species and may have ramifications in the interpretation of preclinical pharmacological studies.

Animals↗

Design and use of 16S ribosomal DNA-directed primers in competitive PCRs to enumerate proteolytic bacteria in the rumen.

Competitive Polymerase Chain Reaction primers were designed for Streptococcus, B. fibrisolvens, P. bryantii, Eubacterium sp., Prevotella, and a universal primer for the eubacteria. DNA was extracted from rumen contents collected from eight dairy cows fed four diets: adequate nitrogen, adequate nitrogen plus carbohydrate, low nitrogen, and low nitrogen plus carbohydrate. B. fibrisolvens was significantly higher on the adequate nitrogen plus carbohydrate and the low nitrogen plus carbohydrate diets compared with the other diets, while P. bryantii was significantly higher on the low nitrogen plus carbohydrate diet compared with the adequate nitrogen diet. The population of Eubacterium sp. was significantly lower on both the adequate nitrogen plus carbohydrate and low nitrogen plus carbohydrate diets. Streptococcus populations were significantly lower on the low nitrogen plus carbohydrate diet compared with all three other diets, whereas there were no significant differences in populations of Prevotella or total eubacteria on any of the diets.

Animal Feed↗

Lotus corniculatus condensed tannins decrease in vivo populations of proteolytic bacteria and affect nitrogen metabolism in the rumen of sheep.

Condensed tannins in forage legumes improve the nutrition of sheep by reducing ruminal degradation of plant protein and increasing crude protein flow to the intestine. However, the effects of condensed tannins in forage legumes on rumen bacterial populations in vivo are poorly understood. The aim of this study was to investigate the specific effects of condensed tannins from Lotus corniculatus on four proteolytic rumen bacteria in sheep during and after transition from a ryegrass (Lolium perenne)-white clover (Trifolium repens) diet (i.e., low condensed tannins) to a Lotus corniculatus diet (i.e., higher condensed tannins). The bacterial populations were quantified using a competitive polymerase chain reaction. Lotus corniculatus was fed with or without ruminal infusions of polyethylene glycol (PEG), which binds to and inactivates condensed tannins, enabling the effect of condensed tannins on bacterial populations to be examined. When sheep fed on ryegrass-white clover, populations of Clostridium proteoclasticum B316T, Butyrivibrio fibrisolvens C211a, Eubacterium sp. C12b, and Streptococcus bovis B315 were 1.5 x 10(8), 1.1 x 10(6), 4.6 x 10(8), and 7.1 x 10(6) mL(-1), respectively. When the diet was changed to Lotus corniculatus, the average populations (after 8-120 h) of C. proteoclasticum, B. fibrisolvens, Eubacterium sp., and S. bovis decreased (P < 0.001) to 2.4 x 10(7), 1.1 x 10(5), 1.1 x 10(8), and 2.5 x 10(5) mL(-1), respectively. When PEG was infused into the rumen of sheep fed Lotus corniculatus, the populations of C. proteoclasticum, B. fibrisolvens, Eubacterium sp., and S. bovis were higher (P < 0.01-0.001) than in sheep fed Lotus corniculatus without the PEG infusion, with average populations (after 8-120 h) of 4.9 x 10(7), 3.8 x 10(5), 1.9 x 10(8), and 1.0 x 10(6), respectively. Sheep fed the Lotus corniculatus diet had lower rumen proteinase activity, ammonia, and soluble nitrogen (P < 0.05-0.001) than sheep that were fed Lotus corniculatus plus PEG. The Lotus corniculatus diet reduced rumen nitrogen digestibility (P < 0.05) and ammonia pool size and increased the flow of undegraded feed nitrogen to the abomasum. The nitrogen intake, rumen non-ammonia nitrogen pool size, rumen microbial non-ammonia nitrogen pool size, and abomasal microbial non-ammonia nitrogen fluxes were similar both in sheep fed only Lotus corniculatus and in sheep fed Lotus corniculatus plus PEG, but nonmicrobial non-ammonia nitrogen flux to the abomasum was higher (P < 0.01) for the sheep fed only Lotus corniculatus. Although condensed tannins in Lotus corniculatus reduced the populations of some proteolytic bacteria, total ruminal microbial protein and microbial protein outflow to the abomasum were unchanged, suggesting a species-specific effect of condensed tannins on bacteria in the rumen.

Animals↗

Isolation and characterisation of a cassava catalase expressed during post-harvest physiological deterioration.

Storage roots of cassava undergo a rapid, endogenous, post-harvest deterioration response that is thought to involve oxidative processes. A cassava catalase (MecCAT1) was isolated from a root cDNA library. The transcript is expressed predominantly in roots with little expression in leaves. Catalase enzyme activity and MecCAT1 transcript expression during the post-harvest period were compared in highly susceptible and less susceptible cultivars and suggest that high levels of catalase activity may play a role in delaying the deterioration response.

Amino Acid Sequence↗

Modification of the human blink reflex by transient and sustained features of acoustic prestimulation.

The effects of acoustic stimuli whose onsets and durations were controlled to vary their transient and sustained features on the size of a subsequently elicited blink reflex were examined in humans. Prestimuli both with and without transient features inhibited the reflex when they preceded the eliciting stimulus by brief lead intervals, showing that acoustic transients are sufficient, but not necessary, for reflex inhibition. Inhibition evoked by transient and sustained stimulus features showed partial summation, and inhibition evoked by stimuli with only transient and with transient and sustained features showed similar decay functions with increasing lead intervals. Blink augmentation was found at longer lead intervals early but not late in a session, and was more evident in women than men. Prestimuli with only transient features were more effective than those with both transient and sustained features, showing that sustained stimulus energy at the time of reflex elicitation is not only not necessary for blink augmentation, but also diminishes it.

Acoustic Stimulation↗

Nutrition, exercise, work, and sex in pregnancy.

This article focuses on the effect of daily living on pregnancy outcome. Although most patients can continue their everyday activities without any concern about effect on pregnancy outcome, all pregnant patients want and need their physician's advice about all of these areas.

Coitus↗

Automated sample preparation of Roxifiban tablets: transfer of a manual method to an automated workstation.

Automation offers obvious advantages for the preparation of tablets prior to analysis by HPLC including unattended operation, minimization of human intervention and an electronic audit trail. However, significant effort has to be put in up front to develop and validate an automated method, particularly if it is required to closely follow an existing manual method. Here, method transfer for Roxifiban, a fibrinogen receptor antagonist, will be discussed. A Zymark tablet processing workstation II (TPWII) was used for all automated sample preparations. Manual methods for composite assay, content uniformity, weight variation and degradation products testing of a tablet formulation were transferred to the TPWII. The method involved weighing of the sample, disintegration of the dosage form by homogenization, extraction of the analyte in the homogenate solution, filtration of the homogenate, dilution of the filtrate and transfer to autosampler vials. Obstacles to a quick transfer included limitations in the volume capabilities of the TPWII, poor analyte solubility and achieving proper conditioning of the transfer lines and filter. After resolving these issues, a validated method was achieved. Spiked recoveries were from 99.4 to 101.1% (RSD's <0.5%). A cross-validation between automated and manual assay methods was compared by Westlake analysis giving a 0.7% calculated interval at the 95% confidence level. Carryover was 0.07% after 20 sample preparations at the highest tablet strength.

Amidines↗

Hydrogen peroxide and flavan-3-ols in storage roots of cassava (Manihot esculenta crantz) during postharvest deterioration.

Cassava storage roots are an important staple food throughout the lowland humid tropics. However, cassava suffers from a poorly understood storage disorder, known as postharvest physiological deterioration (PPD), which constrains its exploitation. In an attempt to broaden the understanding of PPD, nine different cassava cultivars were analyzed for specific compounds accumulating during the process. The production of hydrogen peroxide (H(2)O(2)) is involved in the early stages of PPD in cassava roots. H(2)O(2) was quantified and localized histochemically at the tissue and cell level in deteriorating roots. This reactive oxygen species accumulated during the first 24 h after harvest, especially in the inner parenchymatic tissue. Three flavan-3-ols, (+)-catechin, (+)-catechin gallate, and (+)-gallocatechin, accumulated during the storage of cassava roots. However, these potential antioxidants cannot be related to early storage disorders or wound responses because they start to accumulate only after 4-6 days.

Catechin↗

A novel alpha-amylase gene is transiently upregulated during low temperature exposure in apple fruit.

An alpha-amylase gene product was isolated from apple fruit by reverse-transcriptase PCR using redundant primers, followed by 5' and 3' RACE. The gene is a member of a small gene family. It encodes a putative 46.9 kDa protein that is most similar to an alpha-amylase gene from potato (GenBank accession M79328). In apple fruit this new gene was expressed at low levels, as detected by reverse-transcriptase PCR, in a number of plant tissues and during fruit development. Highest levels of mRNA for this transcript were observed 3 to 9 days after placing apple fruit at 0.5 degrees C. Phylogenetic analysis of amino acid sequence places the potato and apple proteins as a distinct and separate new subgroup within the plant alpha-amylases, which appears to have diverged prior to the split between monocotyledonous and dicotyledonous plants. These two divergent alpha-amylases lack the standard signal peptide structures found in all other plant alpha-amylases, and have sequence differences within the B-domain and C-domain. However, comparisons with structures of known starch hydrolases suggest that these differences are unlikely to affect the enzymatic alpha-1,4-amylase function of the protein. This is the first report of upregulation of a dicotyledonous alpha-amylase in response to low temperature, and confirms the presence of a new family of alpha-amylases in plants.

Amino Acid Sequence↗

Mouse models of tumor development in neurofibromatosis type 1.

Neurofibromatosis type 1 (NF1) is a prevalent familial cancer syndrome resulting from germ line mutations in the NF1 tumor suppressor gene. Hallmark features of the disease are the development of benign peripheral nerve sheath tumors (neurofibromas), which can progress to malignancy. Unlike humans, mice that are heterozygous for a mutation in Nf1 do not develop neurofibromas. However, as described here, chimeric mice composed in part of Nf1-/- cells do, which demonstrates that loss of the wild-type Nf1 allele is rate-limiting in tumor formation. In addition, mice that carry linked germ line mutations in Nf1 and p53 develop malignant peripheral nerve sheath tumors (MPNSTs), which supports a cooperative and causal role for p53 mutations in MPNST development. These two mouse models provide the means to address fundamental aspects of disease development and to test therapeutic strategies.

Animals↗

Preliminary characterization of crystals of an in vitro evolved cyanocobalamin (vitamin B12) binding RNA.

A 35-nucleotide pseudoknot that binds vitamin B12 been isolated using systematic evolution of ligands by exponential enrichment (SELEX). Affinity chromatography was used to purify functional, properly folded molecules and the hanging-drop vapor-diffusion method was used to crystallize this aptamer. Two crystal forms have been obtained and the preliminary crystallographic characterization is reported here. Both crystal forms (space groups I222 or I212121 and C2221) diffract to 2.9 A and should prove sufficient for structure determination.

Base Sequence↗

Analysis of changes in acute-phase plasma proteins in an acute inflammatory response and in rheumatoid arthritis using two-dimensional gel electrophoresis.

Two-dimensional (2-D) gel analysis was used to examine differences in the levels of 19 plasma proteins: before and after an acute inflammatory reaction (parenteral typhoid vaccination) in normal subjects, between rheumatoid arthritis (RA) patients and normals and in RA patients treated with tenidap (120 mg) and piroxicam (20 mg). Typhoid vaccination increased levels of SAA, haptoglobin alpha1, haptoglobin alpha2, haptoglobin beta and alpha1-anti-chymotrypsin but decreased transthyretin and apolipoprotein E. In RA patients, serum amyloid A (SAA), haptoglobin alpha2, haptoglobin beta, alpha1-antichymotrypsin and C3 proactivator levels were elevated while apolipoprotein A-I, apolipoprotein A-IV, transthyretin, Gc-globulin, alpha2-HS glycoprotein, alpha2-macroglobulin and alpha1-B glycoprotein levels were decreased, compared to normals. Compared to piroxicam, tenidap lowered levels of alpha1-antiprotease and SAA but raised the levels of transthyretin, Gc-globulin, alpha2-HS-glycoprotein and alpha2-macroglobulin in RA patients. C-reactive protein (CRP) could not be quantified on 2-D gels but, when measured by rate nephelometry, levels were reduced after treatment with tenidap compared to piroxicam. The general pattern of the acute phase protein response to an acute inflammatory response to typhoid vaccination is similar to that in the chronic inflammatory condition, RA. The impact of tenidap on both positive and negative acute-phase proteins in RA patients could clearly be distinguished from that of piroxicam.

Acute-Phase Proteins↗

Detection of Clostridium proteoclasticum and closely related strains in the rumen by competitive PCR.

A competitive PCR technique was used to enumerate the proteolytic bacterium Clostridium proteoclasticum from the rumen. A PCR primer, which circumscribes this organism and several closely related strains, was designed for a variable region within their 16S rRNA genes and was used in conjunction with a universal forward primer. This primer pair was tested for specificity against 85 ruminal bacterial strains. An internal control DNA was constructed for use in competitive PCRs and was shown to amplify under the same reaction conditions and with the same amplification efficiency as the target DNA. DNA from a known number of C. proteoclasticum cells was coamplified with the internal control to construct a standard curve. Rumen samples were collected from eight dairy cows fed four diets in rotation: high nitrogen, high nitrogen supplemented with carbohydrate, low nitrogen, and low nitrogen supplemented with carbohydrate. DNA extracted from these and spiked with internal control DNA was amplified with the C. proteoclasticum primer pair. The relative intensities of the PCR products were used to quantitate the numbers of C. proteoclasticum cell equivalents from the rumen samples. The numbers ranged from 2.01 x 10(6) ml-1 to 3.12 x 10(7) ml-1. There was no significant effect on the numbers of C. proteoclasticum detected in rumen samples among cows fed the four diets. The utility of the competitive PCR approach for quantifying ruminal bacterial populations in vivo and the occurrence of C. proteoclasticum in forage-fed dairy cows are discussed.

Animals↗

A biophysical study of integral membrane protein folding.

In order to characterize the thermodynamic constraints on the process of integral membrane protein folding and assembly, we have conducted a biophysical dissection of the structure of bacteriorhodopsin (BR), a prototypical alpha-helical integral membrane protein. Seven polypeptides were synthesized, corresponding to each of the seven transmembrane alpha-helices in BR, and the structure of each individual polypeptide was characterized in reconstituted phospholipid vesicles. Five of the seven polypeptides form stable transmembrane alpha-helices in isolation from the remainder of the tertiary structure of BR. However, using our reconstitution protocols, the polypeptide corresponding to the F helix in BR does not form any stable secondary structure in reconstituted vesicles, and the polypeptide corresponding to the G helix forms a hyperstable beta-sheet structure with its strands oriented perpendicular to the plane of the membrane. [The polypeptide corresponding to the C helix spontaneously equilibrates in a pH-dependent manner between a transmembrane alpha-helical conformation, a peripherally bound nonhelical conformation, and a fully water soluble conformation; the conformational properties of this polypeptide are the subject of the accompanying paper: Hunt et al. (1997) Biochemistry 36, 15177-15192.] Our observations suggest that the folding of alpha-helical integral membrane proteins may proceed spontaneously. However, the preference for a non-native conformation exhibited by two of the polypeptides suggests that the formation of some transmembrane substructures could require external constraints such as the links between the helices, interactions with the rest of the protein, or the involvement of cellular chaperones or translocases. Our results also suggest a strategy for improving the thermodynamic stability of alpha-helical integral membrane proteins, a goal that could facilitate attempts to overexpress and/or refold them.

Amides↗

A controlled clinical trial for stuttering in persons aged 9 to 14 years.

This paper presents the results of a controlled trial of child stuttering treatment. The aim of the study was, first, to compare the effectiveness of three viable treatments, and, second, to compare these three treatments to a no-treatment control composed of children who stuttered of a similar age and sex ratio who were on treatment waiting lists. The three treatments investigated included intensive smooth speech, intensive electromyography feedback, and home-based smooth speech. The children/adolescents were assessed across three speaking contexts on measures of percentage syllables stuttered (% SS) and syllables spoken per minute (SPM) and outcomes were assessed 12 months later. Repeated measures analyses of variance demonstrated significant differences between the control group and all three treatment groups across time on conversations in the clinic, on the telephone, and at home (although home measures were not taken for the intensive smooth speech group). Although the controls' stuttering did not change across time, the treatment groups' stuttering was decreased to very low levels posttreatment (less than 1% syllables stuttered on average), with mean improvement in stuttering frequency of at least 85% to 90% across all assessment contexts. Stuttering did not increase significantly up to 3 months and one year posttreatment in the experimental groups, although levels did rise across time (less than 3% syllables stuttered on average). Speech naturalness results showed increasing naturalness across time as rated by the clinician and parent. This was not the case for the controls. The children were also less anxious across time following treatment. The results suggest that all three treatments for children aged 9-14 who stutter were very successful in the long term for over 70% of the group, though the EMG feedback and home-based treatments were superior when percentages falling below a cutoff point (2%SS) were used to discriminate between groups. Implications for child/adolescent treatment in the community are discussed. Long-term outcomes will be assessed up to 5 years after the treatment.

Adolescent↗

Occupational exposure leading to hantavirus pulmonary syndrome in a utility company employee.

Hantavirus pulmonary syndrome is a newly recognized rodent-borne zoonosis. We report a case of hantavirus pulmonary syndrome in an employee of a California utility company who was probably occupationally exposed to Sin Nombre virus. Environmental assessment and genetic comparison of the patient's hantavirus isolates to hantavirus isolates from rodents trapped at possible sites of exposure suggested that the patient contracted his infection at the work site. The study revealed a close correspondence between the patient's viral genotype and that from a rodent trapped at the work site. This report alerts the public health and medical community to the fact that employees of utility companies and similar industries may be an important risk group in areas where hantavirus is endemic and emphasizes the need to incorporate strategies for preventing exposure to hantavirus and other emerging infections into occupational safety protocols.

Animals↗