Applications, and efficient large-scale production, of recombinant human epidermal growth factor.
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Bacterial Infections↗
Biomedical subjects
C Morris
Publications and source records attributed to C Morris.
Identification of bacteria in pasteurized zucchini purées stored at different temperatures and comparison with those found in other pasteurized vegetable purées.
One hundred nineteen isolates from a commercial zucchini purée stored at 4, 10, and 20 to 25 degrees C were fingerprinted using repetitive sequence-based PCR (REP-PCR) and classified into 35 REP types. One representative isolate of each REP type was subsequently identified by API50CHB/20E profile and partial rrs gene sequence analysis. Nine REP types were misidentified by the API system. Strains were misidentified as being in the Bacillus circulans (group 2) API taxon or in taxa with a low number of positive API characters such as Brevibacillus brevis. A phylogenetic analysis pointed to one new species of Bacillus and three new species of Paenibacillus among the misidentified REP types. Bacterial components in zucchini purée were compared phenotypically with those obtained in previous work on broccoli, carrot, leek, potato, and split pea purées, based on simple matching coefficient and unweighted pair group method with averages cluster analysis. Out of 254 strains, 69 strains previously identified as B. circulans (group 2) or B. circulans/B. macerans/B. polymyxa were assigned to a new Paenibacillus taxon phylogenetically related to P. azotofixans. Storage conditions at 4 degrees C favored the development of "B. macroides/B. maroccanus" and Paenibacillus spp. in zucchini purées and Paenibacillus spp. in other purées. Storage conditions at 20 to 25 degrees C favored the development of B. subtilis group (B. licheniformis and B. subtilis) and B. cereus group strains. At 10 degrees C, Paenibacillus spp. were always present at high frequencies, whereas the occurrence of B. macroides/B. maroccanus (in zucchini purées), B. cereus, and B. pumilus varied with the experiment.
Bacillus↗
Pharmacokinetics and tolerability of the orally active selective epidermal growth factor receptor tyrosine kinase inhibitor ZD1839 in healthy volunteers.
OBJECTIVE: To investigate the pharmacokinetics and tolerability of ZD1839 (Iressa), an orally active selective epidermal growth factor receptor-tyrosine kinase inhibitor, in healthy volunteers. DESIGN: Two randomised, double-blind, placebo-controlled, parallel-group studies of pharmacokinetics and tolerability, followed by a nonblind, randomised, 2-period crossover study to assess the effect of food on bioavailability. SETTING: Two centres in the UK. STUDY PARTICIPANTS: Healthy male volunteers aged between 18 and 62 years. INTERVENTIONS: The first study investigated the pharmacokinetics and tolerability of ascending single oral doses of ZD1839 (1 to 75mg). The second study investigated the pharmacokinetics and tolerability of multiple doses of ZD1839 (100mg once daily for 3 days). The third study investigated the effect of food on the bioavailability of a single 50mg dose of ZD1839. OUTCOME MEASURES AND RESULTS: Peak plasma drug concentrations (Cmax) of ZD 1839 occurred between 3 and 7 hours after administration. Cmax and area under the concentration-time curve (AUC) were dose-proportional from 10 to 100mg. The terminal elimination half-life (t1/2beta) was 28 hours (range 12 to 51 hours). Cmax was reduced by 34% and AUC by 14% by ingestion of food; t1/2beta was not affected. Urinary recovery of ZD1839 was <0.5%, indicating that this was not a major route of elimination. The pharmacokinetics of ZD1839 during administration of multiple doses could be predicted from day 1 values. There were no serious adverse events or withdrawals, and the frequency of adverse events was similar that with placebo. CONCLUSIONS: These data support the further clinical investigation of ZD 1839. The elimination half-life suggests that once daily oral administration is appropriate.
Adolescent↗
Student supervision: risky business?
Radical and rapid reform of the national health service (NHS) has impacted significantly on skill-mix and the work organisation of speech and language therapists (SLTs) in recent years. These changes impact on student training at macro and micro levels. In the context of a society-in-transition, student supervision is argued to be a risky business. Six clinicians were selected for in-depth interviewing, using theoretical sampling procedures. A small-scale qualitative enquiry was undertaken to explore the clinicians' perceptions of and attitudes towards the risks involved in delegating clinical work to students. Thematic analysis of transcribed and coded data was carried out. Risks to clients, students and the service are explored from psychological, behavioural, medical and structural perspectives. Risk tolerance and risk management approaches are described.
Education, Professional↗
Parkinson's disease is not associated with the combined alpha-synuclein/apolipoprotein E susceptibility genotype.
A recent study showed significant association of sporadic Parkinson's disease with a polymorphism within the alpha-synuclein gene and closely linked DNA markers on chromosome 4q and the APOE epsilon4 allele. A combined alpha-synuclein/APOE-epsilon4 genotype increased the relative risk of developing Parkinson's disease 12-fold. We failed to confirm this association in a much larger sample of histopathologically proven cases of Parkinson's disease and controls.
Alleles↗
A handmade device for difficult intubation.
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Contraindications↗
Young children's use of functional information to categorize artifacts: three factors that matter.
Three experiments addressed factors that might influence whether or not young children take into account function, as opposed to overall appearance or shape, when they extend the names of novel artifacts. Experiment 1 showed that 4-year-olds more often extend a name on the basis of a demonstrated function when that function provides a plausible causal account of perceptible object structure. Experiment 2 showed that they more often extend a name by function when they respond slowly, and hence thoughtfully. Experiment 3 demonstrated that they are more likely to take function into account when they extend names than when they judge similarities. Comparisons of lexical and non-lexical conditions in younger children failed to show any differences. Overall, the findings suggest that by 4 years of age, children may learn names as labels for novel artifact kinds rather than perceptual classes, and that the processes by which they categorize may be mindful and reflective, as in adults.
Adult↗
Complex patterns of inheritance of an imprinted murine transgene suggest incomplete germline erasure.
Here we report a transgenic mouse line that exhibits significant deviations from a classic pattern of parental imprinting. When the transgene is passed through the female germline, it is completely silenced in some offspring while in others expression is reduced. This variable expressivity does not appear to be the result of differences in the presence of unlinked modifiers. Female transmission of the transgene is associated with hypermethylation. The transgene is generally reactivated on passage through the male germline. Extended pedigrees reveal complex patterns of inheritance of the phenotype. The most likely explanation for this result is that the imprint is not completely erased and reset when passed through the germline of either sex. FISH analysis reveals that the transgene has integrated into chromosome 3 band E3, a region not known to carry imprinted genes, and the integration site shows no sign of allele-specific differential methylation. These findings, in conjunction with other recent work, raise the possibility that the introduction of foreign DNA into the mammalian genome, either through retrotransposition or transgenesis, may be associated with parental imprinting that is not always erased and reset during meiosis.
Animals↗
ICI 182,780 (Faslodex): development of a novel, "pure" antiestrogen.
BACKGROUND: The nonsteroidal antiestrogen tamoxifen is well established as an effective treatment for patients with breast carcinoma, both for the treatment of metastatic disease and as an adjuvant to surgery for patients with primary breast carcinoma. In addition to exerting antagonistic effects on the estrogen receptor, tamoxifen and its derivatives act as partial agonists on certain tissues. These agonistic effects, for example, endometrial stimulation and stimulation of tumor growth after previous response to tamoxifen, may limit their clinical efficacy. ICI 182,780 (Faslodex) from AstraZeneca (Cheshire, United Kingdom) is a novel, steroidal estrogen antagonist that was designed to be devoid of estrogen agonist activity in preclinical models. METHODS: ICI 182,780 was tested in a large number of in vitro and in vivo preclinical models, and its value was assessed clinically when administered before surgery for breast carcinoma and hysterectomy for benign conditions and after failure of tamoxifen in patients with advanced breast carcinoma. RESULTS: All data indicated that ICI 182,780 is devoid of agonist activity in preclinical models and in clinical trials. It inhibits growth of the breast and endometrium. In animal models, it does not cross the blood-brain barrier and appears to be neutral with respect to lipids and bone. ICI 182,780 down-regulates the estrogen receptor and is active in tamoxifen-resistant breast carcinoma. In a small, Phase II study, durable responses were seen: Phase III clinical trials are in progress comparing ICI 182,780 with anastrozole and tamoxifen in the treatment of patients with advanced breast carcinoma. CONCLUSIONS: ICI 182,780 specifically down-regulates the estrogen receptor and, thus, represents the first of a new class of therapeutic agents. In this report, the authors present the current evidence that distinguishes ICI 182,780 from tamoxifen and related nonsteroidal compounds and establishes ICI 182,780 as the first in a new class of therapeutic agents.
Animals↗
High incidence of chromosome 13 deletion in multiple myeloma detected by multiprobe interphase FISH.
Multiple myeloma (MM) is a hypoproliferative malignancy yielding informative karyotypes in no more than 30% of newly diagnosed cases. Although cytogenetic and molecular deletion of chromosome 13 is associated with poor prognosis, a MM tumor suppressor gene (TSG) has not been identified. To localize a minimal deleted region of chromosome 13, clonotypic plasma cells from 50 consecutive patients with MM were subjected to interphase fluorescence in situ hybridization (FISH) analysis using a panel of 11 probes spanning the entire long arm of chromosome 13. Whereas chromosome 13 abnormalities were absent in plasma cells from 25 normal donors, 86% of patients with MM demonstrated such aberrations. Heterogeneity, both in deletion frequency and extent, was confirmed by simultaneous FISH with 2 chromosome 13 probes. Deletion hot spots were noted at D13S272 (70%) and D13S31 (64%), 2 unlinked loci at 13q14. Homozygous deletions at these loci occurred in 12% (simultaneously in 8%) of the cases. Molecular deletions were found in all 14 patients with morphologic deletions, in 21 of 24 with uninformative karyotypes, and 8 of 12 patients with karyotype abnormalities lacking chromosome 13 deletion. Homozygous deletion of any marker was noted in 4% with low and in 36% with higher plasma cell labeling index greater than 0. 4% (P =.01). The absence of increasing deletion incidence and extent with therapy duration suggests that the observed lesions are not induced by treatment. The high incidence and extent of chromosome 13 deletions require the correlation of specific deletion(s) with poor prognosis. These analyses will provide valuable guidance toward cloning of an MM-TSG. (Blood. 2000;96:1505-1511)
Adult↗
How the media do drugs: quality control and the reporting of drug issues in the UK print media.
Exaggeration, distortion, inaccuracy, sensationalism; each of these labels has been consistently applied to the reporting of drug related issues in the print and other media over the last 40 years and beyond. This research sought to understand what quality control mechanisms are employed by the UK print media in relation to issues related to illicit drugs to ensure accurate, informed and appropriate reporting. It was found that the print media in the UK employ almost no quality control mechanisms to ensure that such reporting takes place and that they predominately rely on the demonstrably insufficient qualities of the 'good reporting' skills that journalists bring to their research and writing. What concerns did exist regarding accuracy related predominately to protecting the publication from being sued for libel and no specific journalistic expertise of drug issues was considered necessary. A discussion of these issues is undertaken followed by the recommendation for the production of a negotiated media guide.
Journal Article↗
Regulation of force and unloaded sliding speed in single thin filaments: effects of regulatory proteins and calcium.
1. Measurements of the unloaded sliding speed of and isometric force exerted on single thin filaments in in vitro motility assays were made to evaluate the role of regulatory proteins in the control of unloaded thin filament sliding speed and isometric force production. 2. Regulated actin filaments were reconstituted from rabbit F-actin, native bovine cardiac tropomyosin (nTm), and either native bovine cardiac troponin (nTn), troponin containing a TnC mutant, CBMII, in which the sole regulatory site in cardiac TnC (site II) is inactivated (CBMII-Tn), or troponin containing a point mutation in TnT (I79N, where isoleucine at position 79 is replaced with asparagine) associated with familial hypertrophic cardiomyopathy (FHC). 3. Addition of regulatory proteins to the thin filament increases both the unloaded sliding speed and the isometric force exerted by myosin heads on the thin filaments. 4. Variation of thin filament activation by varying [Ca2+] or the fraction of CBMII/TnC bound to the thin filament at pCa 5, had little effect on the unloaded filament sliding speed until the fraction of the thin filament containing calcium bound to TnC was less than 0.15. These results suggest that [Ca2+] primarily affects the number of attached and cycling crossbridges. 5. The presence of the FHC TnT mutant increased the thin filament sliding speed but reduced the isometric force that heavy meromyosin exerted on regulated thin filaments. These latter results, together with the increased sliding speed and isometric force seen in the presence of regulatory proteins, suggest that thin filament regulatory proteins exert significant allosteric effects on the interaction of crossbridges with the thin filament.
Actins↗
18-year experience with transseptal procedures through baffles, conduits, and other intra-atrial patches.
The presence of an intra-atrial patch (IAP) has been considered a relative contraindication to transseptal puncture (TSP). The purpose of this study is to determine the efficacy and safety of the TSP through baffles, conduits, pericardial patches and other prosthetic materials in the intra-atrial septum. We reviewed the records of all pediatric patients with IAP who underwent TSP at Texas Children's Hospital from November 1979 through February 1998. The review included the cardiac diagnoses, indications for TSP, technical difficulties and follow up echocardiograms specifically addressing residual atrial shunts A total of 1958 TSP were performed. Thirty-nine patients had IAP. Cardiac diagnoses in those 39 patients included D-transposition of the great arteries after Mustard (10) or Senning procedure (6), single ventricle variant post-Fontan operation (4), total anomalous venous return repair (4), atrioventricular canal repair (9) and atrial septal defect with patch repair (6). Patients' age ranged from 1-31 years (median 7 years). The duration from the time of surgical repair to TSP ranged from 0.1-21 years (median 5 years). Indications for TSP included diagnostic and therapeutic intervention for pulmonary venous obstruction (12), creation of a baffle fenestration (2), prosthetic mitral valve evaluation (1), left ventricular outflow tract evaluation (1), access the left heart for hemodynamic evaluation (23). The IAP was traversed in 38/39 patients (97.5%), followed by diagnostic or therapeutic prograde left-heart catheterization. No complications were encountered. Follow up echocardiography in 30/38 PTS demonstrated no residual shunting across the atrial septum except for two cases in which the atrial baffle had been intentionally fenestrated. Transseptal puncture through an intra-atrial patch is a safe procedure. This technique is effective in permitting diagnostic and therapeutic left heart catheterization and does not result in residual shunting through the patch.
Adolescent↗
Delayed benefits of paternal care in the burying beetle Nicrophorus vespilloides.
Burying beetles, Nicrophorus spp., inter the carcasses of small vertebrates as a food source for their offspring. Females can bury a carcass and rear a brood on it alone, but are frequently assisted by a male whose presence reduces the risk of the carcass being taken over by other beetles. However, the male often stays for longer than the carcass is vulnerable to take-over, and he cares for the brood without conferring any further benefits on it. In a laboratory experiment using N. vespilloides, we found that, in the absence of competitors, male assistance conferred no advantages on the brood for which he was caring, but significantly increased the subsequent reproductive success of his mate, in terms of the mass and rate of development of a second brood, reared alone. We suggest that this is due to a reduced parental effort of assisted females, who spent less time feeding offspring and more time resting than unassisted females whilst rearing their first broods. In the field, a female is unlikely to pair with the same male for consecutive broods, so we discuss the possible benefits a male may accrue from increasing his mate's reproductive success. We also discuss the relevance of these results to our understanding of the evolution of biparental care in birds. Copyright 2000 The Association for the Study of Animal Behaviour.
Journal Article↗
Reactivation of heritably silenced gene expression in mice.
Epigenetic modifications that suppress gene activity in mammals are generally considered to be cleared in the germline, restoring totipotency of the genome. Here we report the germline inheritance of transcriptional silencing in mice, and reversion to activity after as many as three generations in the silent state. In a series of lines made with a LacZ transgene, one line exhibits variable expressivity: genotypically identical littermates have proportions of beta-Gal-positive erythrocytes that vary over at least four orders of magnitude, and in some offspring expression is completely silenced. The silent state of the transgene is inherited for multiple generations in the founder strain irrespective of the sex of the parent, implying maintenance of the epigenetic state through meiosis. Crosses of silenced mice with C57BL/6 mice result in reactivation of the transgene in approximately a third of F(1) littermates. The silencing involves a stochastic, all-or-none mechanism. Furthermore, silencing is transcriptional and correlates with methylation of the transgene as well as an inaccessible chromatin structure; these changes are reversed when expression is reactivated. This work supports the notion that silent genetic information in mammals can be inherited and later reactivated, and implies a mode of phenotypic inheritance that is less stable than Mendelian inheritance.
Animals↗
Long-term outcome in congenitally corrected transposition of the great arteries: a multi-institutional study.
OBJECTIVES: The purpose of this study was to determine long-term outcome in adults with congenitally corrected transposition of the great arteries (CCTGA), with particular emphasis on systemic ventricular dysfunction and congestive heart failure (CHF). BACKGROUND: Patients with CCTGA have the anatomical right ventricle as their systemic pumping chamber, with ventricular dysfunction and CHF being relatively common in older adults. METHODS: Retrospective analysis of records of 182 patients from 19 institutions were reviewed to determine current status and possible risk factors for systemic ventricular dysfunction and CHF. Factors considered included age, gender, associated cardiac defects, operative history, heart block, arrhythmias and tricuspid (i.e., systemic atrioventricular) regurgitation (TR). RESULTS: Both CHF and systemic ventricular dysfunction were common in groups with or without associated cardiac lesions. By age 45, 67% of patients with associated lesions had CHF, and 25% of patients without associated lesions had this complication. The rates of systemic ventricular dysfunction and CHF were higher with increasing age, the presence of significant associated cardiac lesions, history of arrhythmia, pacemaker implantation, prior surgery of any type, and particularly with tricuspid valvuloplasty or replacement. Aortic regurgitation (a previously unreported problem) was also relatively common in this patient population. CONCLUSIONS: Patients with CCTGA are increasingly subject to CHF with advancing age; this complication is extremely common by the fourth and fifth decades. Tricuspid (systemic atrioventricular) valvular regurgitation is strongly associated with RV (anatomical right ventricle connected to aorta in CCTGA patients; systemic ventricle in CCTGA) dysfunction and CHF; whether it is causative or a secondary complication remains speculative.
Adult↗
Hydroxychloroquine for the treatment of chronic graft-versus-host disease.
Chronic graft-versus-host disease (GVHD) is a major complication of allogeneic bone marrow transplantation. Both the disease and the medications used to treat it are associated with significant morbidity and mortality. The manifestations of chronic GVHD often resemble those of autoimmune disorders. Hydroxychloroquine (HCQ) is a 4-aminoquinoline antimalarial drug used for the treatment of autoimmune diseases. HCQ interferes with antigen processing and presentation, cytokine production, and cytotoxicity and is synergistic with cyclosporine and tacrolimus in vitro. Forty patients with steroid-resistant or steroid-dependent chronic GVHD were enrolled in a phase 2 trial of HCQ 800 mg (12 mg/kg) per day. Three complete responses and 14 partial responses were seen in 32 evaluable patients (53% response rate). All responders tolerated a >50% reduction in their steroid dose while receiving HCQ. Clinical response occurred at a median of 8 weeks (range, 4 to 24 weeks). No hematologic, hepatic, renal, or retinal toxicity was associated with HCQ. In light of its mechanisms of action, clinical activity for GVHD, and low toxicity profile, HCQ may be useful in a multiagent approach for the treatment of extensive chronic GVHD.
Adolescent↗
Towards a closed eye model of the pre-ocular tear layer.
Although the tear film has been extensively studied as it exists in the open eye state, until recently very little was known as to what happens to the tear film on eye closure. Recent studies have shown that eye closure results in a profound change in the composition, origins, turnover and physiological functions of the tear film. These changes include a shift from an inducible, neurologically controlled, lacrimal secretion containing among other proteins primarily lysozyme, lactoferrin and tear specific lipocalin, to a much slower, constitutive-type of secretion, composed almost exclusively of sIgA. This change is accompanied by the build-up of sialoglycoproteins of epithelial and goblet cell origin, the build-up and activation of complement and the build-up of serum proteins. In addition, various cytokines and proinflammatory mediators accumulate, including some which are potent inducers of angiogenesis and leukochemotaxis. The closed eye also exhibits the recruitment and activation of massive numbers of PMN cells. This results in a stagnant, closed eye layer, which is extremely rich in reactive complement products, PMN cell proteases including protease-3, elastase, capthepsin G, MMP-9 and urokinase. We have postulated that this shift represents a fundamental change in host-defense strategies from a passive-barrier defense to an active immune, inflammatory, phagocyte-mediated process and that this shift is necessitated in order to protect the cornea from entrapped microorganisms. Studies have shown that autologous cell damage is avoided in closed eye tear fluid, by the accumulation of several modulators of complement activation, which shift activation towards opsonization of entrapped microorganisms and the build-up of a wide array of antiproteases. Some of the latter are likely to arise from the ocular surface tissues. Corneal neovascularization may be avoided in part by the build-up of alpha2-macroglobulin and the conversion of plasminogen to angiostatin. It is highly probable that other bioactive protein fragments are produced in the closed eye, which contribute to homeostasis. Areas of future study are indicated.
Circadian Rhythm↗