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Biomedical subjects

G Green

Publications and source records attributed to G Green.

At least 37 records · Page 2Linked to original sources
PubMed2000

Detection of hepatitis C core antigen in the antibody negative 'window' phase of hepatitis C infection.

BACKGROUND AND OBJECTIVES: Despite improvements in assays for anti-HCV, there remains a significant delay before the appearance of antibodies following infection, during which, circulating viral RNA is present. We have evaluated a prototype assay for the serological detection of hepatitis C virus (HCV) core antigen with specimens derived from the early phase of HCV infection. MATERIALS AND METHODS: Serial specimens from 24 individuals undergoing HCV seroconversion were tested for the presence of anti-HCV, HCV RNA and HCV core antigen. RESULTS: HCV antigen was detected at the same time as HCV RNA in 83% (20/24) cases. The mean time to the first detection of HCV antigen was approximately 1 day later than HCV RNA. Overall, 87% of HCV-RNA-positive specimens contained detectable HCV core antigen. CONCLUSION: These results indicate that HCV core antigen can be identified by routine serological ELISA in specimens from the early antibody-negative phase of HCV infection. A test for HCV core antigen may be a useful test for identifying window phase blood donations from antibody negative donors infected with HCV.

Enzyme-Linked Immunosorbent Assay↗
PubMed2000

An acceptability study of female-controlled methods of protection against HIV and STDs in south-western Uganda.

We aimed to assess the acceptability of a variety of formulations of female-controlled methods of protection against HIV and STDs among men and women in south-western Uganda. Pilot interviews were carried out with 50 men and 55 women and 25 focus group discussions (FGDs) were held with 138 women and 42 men. The female condom, foaming tablets, sponge, foam, gel and film were demonstrated to 146 women and 35 of their male partners, who then tried out 2 of the products. They were interviewed 7 times during the course of 5 months. At the end experiences were evaluated during a second series of FGDs. Sixty-five (45%) women completed the trial. The main reasons for non-completion were related to geographical mobility. Product preference after the initial demonstration was similar to that at the end of the trial. The most popular formulations were the sponge (25% of the women), foaming tablets (23%), and the female condom (19%). The foam was of medium popularity (16%). The gel (9%) and film (7%) were least popular. Ten per cent of the women and 14% of the men reported products interfering with sexual enjoyment; 24% of the women and 67% of the men said products increased enjoyment. 'Dry sex' is not popular in this area and increased lubrication was an important determinant of acceptability. Age, level of education and location did have some effect on preference. Although secrecy was a dominant theme in the FGDs, 87% of the women had informed their partners by the end of the trial. The products were generally well received. Female control was an important issue for both sexes. Male attitudes were ambivalent because female ownership of products increased women's control. Although they have clear preferences, women appear to accept the products generally and might use a single available product just as readily if choice was limited, as long as it conforms to general cultural preferences, such as those relating to wet/dry sex.

Adolescent↗
PubMed2000

Clinical service lines bring patients into focus.

In 1996, SSM St. Joseph Hospital of Kirkwood, Mo., was in crisis mode. A radical structure change from centralized nursing to clinical service lines helped to keep the organization in the black.

Disease Management↗
PubMed1999

An immunological assay for determination of baculovirus titers in 48 hours.

Th baculovirus expression system is a system of choice for expressing eukaryotic proteins. Large amounts of biologically active material can be generated using this system by infecting insect cells with a baculovirus expressing the target protein. At several stages during the production of a baculovirus stock, it is necessary to titer the virus. Current methods have long time lines and are either technically difficult or are limited to viruses expressing a reporter gene. The new assay described here yields titers in 48 h, is easy to perform using 96-well plates, and is applicable to any Autographa californica nucleopolyhedrovirus-based recombinant baculovirus. This assay uses an antibody to a viral envelope glycoprotein to detect infected cells via immunostaining. The titer is determined by counting foci of infection under a light microscope. The required incubation period is shortened considerably because infected cells express viral antigens long before the macroscopic signs of infection scored in other assays become apparent. Titers determined using this immunological assay are comparable, both in value and variability, to those obtained using a traditional method, provided that the stocks have titers above 10(4) pfu/ml.

Animals↗
PubMed1999

Family-oriented care during pediatric inter-hospital transport.

We evaluated the family-oriented care and counseling provided by the BC Children's Hospital Transport Team paramedies. One hundred families were asked to rate: (1) how they would like paramedies to communicate with them under ideal conditions; and (2) what they actually experienced during their child's transport. There were no significant differences in parents' preferences under ideal circumstances and what they actually experienced in five of nine behavioural areas studied. Nineteen paramedies also rated their use of elements of family-oriented communication and the strategies they would recommend other teams use when interacting with families. The elements that paramedies reported using most frequently were rated highly by parents and produced positive feelings in the majority of families. The study indicates that effective counseling can be achieved in 'critical', time-limited situations but improvements can be made; and it supports the value of appropriate selection and training of transport team personnel in family-oriented critical care.

Adult↗
PubMed1999

An update on radiation therapy in breast cancer.

Radiation therapy plays an important role in the management of both invasive and noninvasive breast cancer. During the last 20 years, the availability of radiation therapy has made it possible to test the feasibility and safety of breast preservation after the diagnosis of early-stage breast cancer. This article summarizes some of the ongoing controversies concerning the use of radiation therapy in the multidisciplinary management of breast cancer.

Breast Neoplasms↗
PubMed1999

Women's attitudes to condoms and female-controlled means of protection against HIV and STDs in south-western Uganda.

The consistent and correct use of the male condom makes it highly effective in both disease prevention and as a contraceptive method. However, it is also well recognized that its use is under men's control. Because of this vital limitation, there have been frequent calls for female-controlled methods of HIV prevention, particularly from women from sub-Saharan Africa. Here we report on data collected in focus-group discussions (FGDs) with women aged 17-54 in South-Western Uganda. A total of 138 women, from rural villages, urban family planning clinics and a truck-stop town, were recruited to participate in 18 FGDs on the male condom, the female condom and existing formulations of vaginal microbicidal products. Three themes emerged: (i) problems with men's control over the male condom, (ii) the importance of control over and secrecy about protective measures and (iii) sexual pleasure associated with different methods. We found that the female condom, while being perceived as an improvement over the male condom, was recognized as having limited value because of the need to agree its use prior to sex taking place. Other products were considered to be significantly better than the female condom; the sponge, in particular, was perceived as having advantages over every other product. Women like the fact that it could be inserted some time before, and left in place some time after, sexual intercourse, that it was effective for multiple instances of intercourse, and that men would be unaware that it was being employed. Female-controlled methods to prevent sexually transmitted infections, including HIV, and to increase reproductive choice, hold the promise of ceding some control over sexual and reproductive health to women.

Adolescent↗
PubMed1999

Emergency psychiatric assessments: do outcomes match priorities?

The targeting of scarce mental health resources is currently organised around three broad areas: treating severe mental illness; reducing suicide; and obviating risk to the wider community. High priority clients are those who present with either psychotic symptoms, or who are perceived to be high risk to self or others. This study examined records of emergency assessments at a mental health trust in the south-east of England over a three-month period (n = 336) to see whether clients with these characteristics are more likely than others to be offered hospital admission or treatment. It was found that clients presenting with psychosis are much more likely to be offered admission than those assessed as non-psychotic, that those assessed as a suicide risk are also significantly more likely to be offered admission, and that those assessed as presenting a risk to the public at large are no more likely to be admitted than those presenting no risk. This investigation indicates that the emergency service of the trust studied is addressing the first two target areas, but may be underperforming in the third.

Adult↗
PubMed1999

Proposed fellowship training program in international emergency medicine.

Interest in international emergency medicine (EM) has grown steadily over the last ten years. This growth has been fueled by increased demand for emergency services abroad and the proliferation of emergency physicians (EPs) working in international relief and development. As a response, several academic EM programs have developed international EM fellowships for the purpose of providing formal training to EPs interested in international health. Although there have been preliminary articles describing fellowship curricula, to the authors' knowledge no recommendations have been proposed by national consensus that suggest emphasis or required components of a fellowship program. Therefore, a group of EPs interested in fellowship training convened for the purpose of developing goals and objectives for a postgraduate training program in international EM. To that end, this article proposes guidelines for a fellowship training program for international EM.

Curriculum↗
PubMed1999

Shared responsibility for ongoing rehabilitation: a new approach to home-based therapy after stroke.

OBJECTIVE: To assess the efficacy of a programme of continuing self-directed exercises for people discharged home after a stroke, supervised once a week by therapists. DESIGN: A randomized controlled trial of 100 patients discharged from hospital after a stroke, requiring ongoing therapy. The control group received outpatient or day hospital therapy; the experimental group were visited once a week by an occupational and/or physiotherapist who prescribed a programme of exercises and activities for the following week. Subjects were studied for the first three months after discharge from hospital. SETTING: A district general hospital, or the homes of subjects randomized to the experimental group, in New Zealand. MAIN OUTCOME MEASURES: (1) Characteristics of the groups, (2) gait speed, limb function, activities of daily living, (3) time with therapists, (4) mood of both subjects and caregivers, (5) anticipation of outcome at entry, compared with perceived outcome at exit. RESULTS: No statistical differences between the control and experimental groups in characteristics, or in any outcomes measured, except that the contact time period, but not the number of visits, was longer in the experimental group (p = 0.003). CONCLUSIONS: A supervised home-based programme is as effective as outpatient or day hospital therapy.

Aged↗
PubMed1999

A discrimination analysis of training-structure effects on stimulus equivalence outcomes.

Experiments designed to establish stimulus equivalence classes frequently produce differential outcomes that may be attributable to training structure, defined as the order and arrangement of baseline conditional discrimination training trials. Several possible explanations for these differences have been suggested. Here we develop a hypothesis based on an analysis of the simple simultaneous and successive discriminations embedded in conditional discrimination training and testing within each of the training structures that are typically used in stimulus equivalence experiments. Our analysis shows that only the comparison-as-node (many-to-one) structure presents all the simple discriminations in training that are subsequently required for consistently positive outcomes on all tests for the properties of equivalence. The sample-as-node (one-to-many) training structure does not present all the simple discriminations required for positive outcomes on either the symmetry or combined transitivity and symmetry (equivalence) tests. The linear-series training structure presents all the simple discriminations required for consistently positive outcomes on tests for symmetry, but not for symmetry and transitivity combined (equivalence) or transitivity alone. Further, the difference in the number of simple discriminations presented in comparison-as-node training versus the other training structures is larger when the intended class size is greater than three or the number of classes is larger than two. We discuss the relevance of this analysis to interpretations of stimulus equivalence research, as well as some methodological and theoretical implications.

Discrimination Learning↗
PubMed1998

Improved fluorescence and dual color detection with enhanced blue and green variants of the green fluorescent protein.

The green fluorescent protein (GFP) from the jellyfish Aequorea victoria is a versatile reporter protein for monitoring gene expression and protein localization in a variety of systems. Applications using GFP reporters have expanded greatly due to the availability of mutants with altered spectral properties, including several blue emission variants, all of which contain the single point mutation Tyr-66 to His in the chromophore region of the protein. However, previously described "BFP" reporters have limited utility, primarily due to relatively dim fluorescence and low expression levels attained in higher eukaryotes with such variants. To improve upon these qualities, we have combined a blue emission mutant of GFP containing four point mutations (Phe-64 to Leu, Ser-65 to Thr, Tyr-66 to His, and Tyr-145 to Phe) with a synthetic gene sequence containing codons preferentially found in highly expressed human proteins. These mutations were chosen to optimize expression of properly folded fluorescent protein in mammalian cells cultured at 37 degreesC and to maximize signal intensity. The combination of improved fluorescence and higher expression levels yield an enhanced blue fluorescent protein that provides greater sensitivity and is suitable for dual color detection with green-emitting fluorophores.

Fluorescence↗
PubMed1998

PCR analysis of tissue samples from the 1979 Sverdlovsk anthrax victims: the presence of multiple Bacillus anthracis strains in different victims.

An outbreak of human anthrax occurred in Sverdlovsk, Union of Soviet Socialists Republic (now Ekaterinburg, Russia) in April 1979. Officials attributed this to consumption of contaminated meat, but Western governments believed it resulted from inhalation of spores accidentally released from a nearby military research facility. Tissue samples from 11 victims were obtained and methods of efficiently extracting high-quality total DNA from these samples were developed. Extracted DNA was analyzed by using PCR to determine whether it contained Bacillus anthracis-specific sequences. Double PCR using "nested primers" increased sensitivity of the assay significantly. Tissue samples from 11 persons who died during the epidemic were examined. Results demonstrated that the entire complement of B. anthracis toxin and capsular antigen genes required for pathogenicity were present in tissues from each of these victims. Tissue from a vaccination site contained primarily nucleic acids from a live vaccine, although traces of genes from the infecting organisms were also present. PCR analysis using primers that detect the vrrA gene variable region on the B. anthracis chromosome demonstrated that at least four of the five known strain categories defined by this region were present in the tissue samples. Only one category is found in a single B. anthracis strain.

Animals↗
PubMed1998

Antimicrobial activity of antiseptic-coated orthopaedic devices.

Antimicrobial coating of medical devices, including fracture fixation devices, has evolved as a potentially effective method for preventing device-related infections. We examined the in vitro antimicrobial activity of titanium cylinders coated with the antiseptic combination of chlorhexidine and chloroxylenol. The coated devices provided zones of inhibition against Staphylococcus epidermidis, S. aureus, Pseudomonas aeruginosa, Escherichia coli and Candida albicans, at baseline and up to 8 weeks after incubation of the coated cylinders in human serum at 37 degrees C. This durable antimicrobial activity was attributed to the relatively slow leaching of chlorhexidine and chloroxylenol from the coated cylinders as measured by high-performance liquid chromatography. These results suggest that antiseptic-coated orthopaedic devices may provide broad-spectrum and durable antimicrobial protection against device-related infection.

Anti-Infective Agents, Local↗
PubMed1998

Structure and expression of several bean (Phaseolus vulgaris) nuclear transfer RNA genes: relevance to the process of tRNA import into plant mitochondria.

Bean nuclear genes for tRNA(Pro), tRNA(Thr) and tRNA(Leu) were isolated. Expression of the tRNA(Pro) genes was demonstrated in vivo and sequence analysis suggested amplification of the tRNA(Pro) gene copy number through duplication of a gene cluster at the same locus of the bean genome. The two tRNA(Thr) genes isolated were actively transcribed and their transcripts processed in a HeLa cell system. In vivo expression tests of these genes and aminoacylation assays of the corresponding in vitro transcripts showed the presence of identity determinants in the anticodon of plant tRNA(Thr). The tRNA(Leu) gene was not expressed due to deviation from the consensus in the internal B-box promoter. The same sequence deviation also prevented aminoacylation of the corresponding in vitro transcript. This tRNA(Leu) however exists in plants and is synthesized from another gene with a consensus B-box promoter. Plant mitochondria import from the cytosol a number of nucleus-encoded tRNAs, including tRNA(Leu) and tRNA(Thr). From the available sequence data, we could not identify any conserved structural motif characteristic for the nucleus-encoded tRNAs imported into plant mitochondria, either in the tRNAs, or in the gene flanking sequences. These results suggest that recognition of tRNAs for import is idiosyncratic and likely to depend on protein/RNA interactions that are specific to each tRNA or each isoacceptor group.

Base Sequence↗
PubMed1998

Characteristics of new referrals to twenty-seven lymphoedema treatment units.

Lymphoedema affects 25-28% of patients who have undergone axillary surgery or radiotherapy in the treatment of cancer. The prevalence of primary lymphoedema or of lymphoedema secondary to non-cancer causes is unknown. In addition, basic demographic and disease characteristics of the lymphoedema population remain undocumented. We conducted a prospective survey to determine these characteristics. Lymphoedema treatment clinics in the UK were invited to participate at the British Lymphology Society 1996 Annual Conference. Twenty-seven clinics collected a standard data set for all new referrals in a 3-month period in 1997. The sample size was 603. The mean number of new referrals was 7.4 patients per unit per month. Eighty per cent of patients had cancer-related lymphoedema, and 86% of patients were female. Patients' mean age was 61.0 years. Thirty-seven per cent of the sample had suffered lymphoedema for less than 3 months, and 15% for 5 years or more. Patients with non-cancer related oedema had suffered the condition disproportionately longer than the cancer-related group (chi 2 = 102.2, P < 0.001). Sixty-six per cent of patients were reported as having lymphoedema at more than one site. Seventy-four per cent of all patients suffered unilateral limb oedema, and 23% bilateral limb oedema. Bilateral swelling was recorded for 67% of the non-cancer related group and 13% of the cancer related group (chi 2 = 153.4, P < 0.001). Median percentage excess volume (PCEV) for all patients with unilateral limb oedema was 16.4%. There was a positive relationship between PCEV and duration of the condition (H = 24.0, P < 0.001), and PCEV and non-cancer related lymphoedema (H = 10.5, P < 0.05). These results suggest that patients with non-cancer related lymphoedema and those with cancer-related lymphoedema form two distinct groups. The former present substantial management problems which are made more complex by late referral.

Adolescent↗
PubMed1998

Visual identity matching and auditory-visual matching: a procedural note.

After preliminary computerized training on visual-visual identity matching, a 5-year-old boy with autism (Sam) was given visual-visual and auditory-visual matching-to-sample tests with new stimuli. He did well in matching dictated name samples to 20 pictures, 26 printed upper case letters, and 9 single-digit numbers. In matching the visual stimuli (pictures, letters, or numbers) to themselves, however, he did not perform well. We then increased the number of picture comparisons per trial from two to three. In tests after this three-comparison training, Sam correctly matched on 95% of the original 20-stimulus, four-comparison, identity-matching test trials. He went on to demonstrate accurate identity matching of the numbers, letters, and new pictures. In identity-matching tests on the table top, he performed poorly until the stimulus array was made to resemble the stimulus arrangement on the computer. These findings showed that seemingly small procedural changes can influence performance and demonstrated that successful auditory-visual matching does not guarantee proficiency in visual-visual identity matching.

Auditory Perception↗