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Biomedical subjects

S Johnson

Publications and source records attributed to S Johnson.

At least 109 records · Page 6Linked to original sources
PubMed2000

Service use and costs of people with dual diagnosis in South London.

OBJECTIVE: To compare the service use and costs of individuals who have a dual diagnosis of psychosis and substance abuse with those who have a diagnosis of psychosis but no substance abuse. METHOD: Patients with psychosis were identified and a representative sample were interviewed. Six-month service use was measured and costs calculated. Regression models were developed to predict costs from background characteristics and dual diagnosis status. RESULTS: A greater proportion of the patients with dual diagnosis used community psychiatric nurses, in-patient care and the emergency clinic. The regression analysis revealed that dual diagnosis patients had significantly higher 'core' psychiatric service costs (a difference of pound sterling 1362) and non-accommodation service costs (pound sterling 1360) than non-dual-diagnosis patients. The difference when all services were analysed was pound sterling 1046, but this was not statistically significant. CONCLUSION: Specific interventions for dual diagnosis patients should be introduced and assessed in terms of individual outcomes, service use and costs.

Adult↗
PubMed2000

Modification of general practitioner prescribing of antibiotics by use of a therapeutics adviser (academic detailer).

AIMS: This was a pilot study of the use of a clinical pharmacist as a therapeutics adviser (academic detailer) to modify antibiotic prescribing by general practitioners. METHODS: Following a visit by the adviser (March-May), 112 general practitioners were recruited and randomised to control or active groups. A panel of experts prepared a best practice chart of recommended drugs for upper and lower respiratory tract infections, otitis media and urinary tract infections. The adviser made a 10-15 min visit to each prescriber in the active group (June-July), gave them the chart and discussed its recommendations briefly. Doctors in the control group were not visited nor given the chart. Prescription numbers for all prescribers were obtained from the Commonwealth Health Insurance Commission for the pre(March-May) and postdetailing (August-September) periods using a three month lag time for data collection. Data for total numbers of prescriptions and for selected individual antibiotics used in these two periods were analysed using nonparametric statistics. RESULTS: Prescribing patterns were similar for the control and active groups in the predetailing period. For both groups, there were significant (P<0.03) increases (45% for control and 40% for active) in total number of antibiotic prescriptions in the post compared with the predetailing period. This trend was anticipated on the basis of the winter seasonal increase in respiratory infections. In line with the chart recommendations for first-line treatment, doctors in the active group prescribed significantly more amoxycillin (P<0.02) and doxycycline (P<0.001) in the post vs predetailing periods. By contrast, doctors in the control group prescribed significantly more cefaclor (P<0.03) and roxithromycin (P<0.03), drugs that were not recommended. The total cost of antibiotics prescribed by doctors in the control group increased by 48% ($37 150) from the preto postdetailing periods. In the same time period, the costs for the active group increased by only 35% ($21 020). CONCLUSIONS: We conclude that the academic detailing process was successful in modifying prescribing patterns and that it also decreased prescription numbers and costs. Application of the scheme on a nationwide basis could not only improve prescriber choice of the most appropriate antibiotic but also result in a significant saving of health care dollars.

Anti-Bacterial Agents↗
PubMed2000

Haemostatic screening and identification of zebrafish mutants with coagulation pathway defects: an approach to identifying novel haemostatic genes in man.

Zebrafish were used as a model to study haemostasis, a vertebrate function of paramount importance. A limitation of the zebrafish model is the difficulty in assaying small amounts of blood to detect coagulation mutants. We report the use of a rapid total coagulation activity (TCA) assay to screen for coagulation defects in individual adult zebrafish. We screened the TCA in 1000 gynogenetic half-tetrad diploids derived from 86 clutches. Each clutch was from a single F1 female offspring of males mutagenized with ethylnitrosourea (ENU). We found 30-50% defective zebrafish among six clutches, consistent with a heritable defect. The assay developed here provided a rapid screen to detect overall coagulation defects. However, because of the limited amounts of plasma, we could not detect defects in specific pathways. Therefore, a novel, ultra-sensitive kinetic method was developed to identify specific pathway defects. To test whether the kinetic assay could be used as a screening tool, 1500 Florida wild-type zebrafish pairs were analysed for naturally occurring coagulation defects. We detected 30 fish with extrinsic pathway defects, but with intact common and intrinsic pathways. We conclude that it is now possible to identify specific coagulation pathway defects in zebrafish.

Actins↗
PubMed2000

p53 intronic point mutation, aberrant splicing and telomeric associations in a case of B-chronic lymphocytic leukaemia.

We report a case of chronic lymphocytic leukaemia (CLL) with telomeric associations and a p53 intronic point mutation. Karyotypic analysis revealed clonal and non-clonal telomeric associations, accompanied by clonal cytogenetic abnormalities and also in isolation. The p53 mutation, which occurred at the invariant base pair -2 of the splice acceptor site in intron 7 resulted in the abolition of correct splicing of exon 7 to exon 8. Multiple aberrant splice products were characterized, all of which differed from wildtype in the DNA binding domain. Fluorescence in situ hybridization demonstrated that the clone retained two copies of the p53 gene and wild-type p53 transcript was detected on cloning of reverse transcriptase polymerase chain reaction (RT-PCR) product, indicating that one wild-type allele remained. However, a plasmid clone with correct splicing at the exon 7/8 boundary, but with a 21 bp deletion in exon 8, was also found at low frequency. This finding indicates clonal evolution, resulting in complete loss of wild-type p53. The intronic point mutation was not present in DNA extracted from cervical tissue indicating that it was a leukaemic phenomenon. This is the first case of an intronic point mutation to be reported in CLL. This mutation led to chaotic p53 expression and, interestingly, occurred in a case showing telomeric associations, a rare phenomenon in B-CLL.

Amino Acid Sequence↗
PubMed2000

Fine specificity of autoantibodies to calreticulin: epitope mapping and characterization.

Extracellular calreticulin (CRT) as well as anti-CRT antibodies have been reported in patients with various autoimmune disorders and CRT has been implicated in 'epitope spreading' to other autoantigens such as the Ro/SS-A complex. In addition, antibodies against parasite forms of the endoplasmic reticulum chaperone, CRT, have been found in patients suffering from onchocerciasis and schistosomiasis. In this study, we screened sera for anti-CRT antibodies from patients with active and inactive systemic lupus ertythematosus (SLE) and primary or secondary Sjögren's syndrome. Approximately 40% of all SLE patients were positive for anti-CRT antibodies. The antigenic regions of CRT were determined using full length CRT and fragments of CRT prepared in yeast and Escherichia coli, respectively. Synthetic 15mer peptides corresponding to the major autoantigenic region of CRT (amino acids 1-289), each one overlapping by 12 amino acids, were used to map the B cell epitopes on the CRT protein recognized by autoimmune sera. Major antigenic epitopes were found to be associated with the N-terminal half of the protein in 69% of the SLE sera from active disease patients, while the C-domain was not antigenic. Major epitopes were found to be reactive with antibodies in sera from SLE patients with both active and inactive disease, spanning different regions of the N and P-domains. Sera from both healthy and disease controls and primary Sjögren's syndrome patients were non-reactive to these sequences. Limited proteolysis of CRT with two major leucocyte serine proteases, elastase and cathepsin G, demonstrated that an N-terminal region of CRT is resistant to digestion. Interestingly, some of the epitopes with the highest reactivity belong to the fragments of the protein which bind to C1q and inhibit complement activation. Whether C1q association with CRT is a pathological or protective interaction between these two proteins is currently under investigation.

Adult↗
PubMed2000

The possible role of gradual accumulation of copper, cadmium, lead and iron and gradual depletion of zinc, magnesium, selenium, vitamins B2, B6, D, and E and essential fatty acids in multiple sclerosis.

Multiple sclerosis (MS) has a much higher incidence among caucasians that in any other race. Furthermore: females are much more susceptible than males and white females living in colder, wetter areas are much more susceptible than those living in warmer areas. On the other hand, menstruating women have increased copper (Cu) absorption and half-life, so they tend to accumulate more Cu than males. Moreover, rapidly growing girls have an increased demand for zinc (Zn), but their rapidly decreasing production of melatonin results in impaired Zn absorption, which is exacerbated by the high Cu levels. The low Zn levels result in deficient CuZnSuperoxide dismutase (CuZnSOD), which in turn leads to increased levels of superoxide. Menstruating females also often present with low magnesium (Mg) and vitamin B6 levels. Vitamin B6 moderates intracellular nitric oxide (NO) production and extracellular Mg is required for NO release from the cell, so that a deficiency of these nutrients results in increased NO production in the cell and reduced release from the cell. The trapped NO combines with superoxide to form peroxinitrite, an extremely powerful free radical that leads to the myelin damage of MS. Iron (Fe), molybdenum (Mo) and cadmium (Cd) accumulation also increase superoxide production. Which explains MS in males, who tend to accumulate Fe much faster and Cu much less rapidly than females. Since vitamin D is paramount for Mg absorption, the much reduced exposure to sunlight in the higher latitudes may account for the higher incidence in these areas. Moreover, vitamin B2 is a cofactor for xanthine oxidase, and its deficiency exacerbates the low levels of uric acid caused by high Cu levels, resulting in myelin degeneration. Finally Selenium (Se) and vitamin E prevent lipid peroxidation and EPA and DHA upregulate CuZnSOD. Therefore, supplementation with 100 mg MG, 25 mg vit B6, 10 mg vit B2, 15 mg Zn and 400 IU vit D and E, 100 microg Se, 180 mg EPA and 120 mg DHA per day between 14 and 16 years of age may prevent MS.

Adolescent↗
PubMed2000

Iron catalyzed oxidative damage, in spite of normal ferritin and transferrin saturation levels and its possible role in Werner's syndrome, Parkinson's disease, cancer, gout, rheumatoid arthritis, etc.

Iron loading in hemochromatosis attains extremely high levels and is accompanied by many signs (ferritin >300 microg/l, hematocrit >50%, transferrin saturation >70%, etc.). Nevertheless, the disease is often overlooked by physicians, until several organs have been damaged permanently (heart, liver, brain, pancreas, kidneys, spleen, etc.). Therefore, severe oxidative damage catalyzed by Fe could occur, without the extremely high ferritin, hematocrit and transferrin saturation levels of hemochromatosis, and it is unlikely that it would ever be detected or even suspected. I postulate a mechanism, by which a cell can continue to express transferrin receptors, without producing ferritin, even when it is saturated with iron. Furthermore, I suggest that this silent iron loading, induced by cadmium and other metals, plays an important role in many degenerative diseases involving free radicals, DNA damage and peroxynitrite, all of which are intimately linked to iron.Moreover, since ferritin, transferrin saturation and hematocrit levels are not directly related to cellular iron levels, and since excess iron can wreak havoc in the cell, we can conclude that there is a need for a better way to evaluate intracellular iron levels and especially the intracellular free iron levels by a non-invasive technique.Finally, phlebotomy is suggested as the best way to reduce Fe and Mo stores, and chelation with succimer is recommended in order to eliminate Cd.

Chelating Agents↗
PubMed2000

Effect of fatty acids and oils on photodegradation of azadirachtin-A.

Azadirachtin-A on exposure to UV-light (254 nm) as a thin film on glass surface gave a isomerised (Z)-2-methylbut-2-enoate product. Half-life of azadirachtin-A as thin film under UV light was found to be 48 min. Azadirachtin-A was irradiated along with saturated and unsaturated fatty acids, and fatty oils under ultra-violet light as thin film. Saturated fatty acid increased the rate of photodegradation of azadirachtin-A, whereas unsaturated fatty acids such as oleic, linoleic and elaidic acid reduced the rate of degradation. Castor, linseed and olive oil accelerated the rate of degradation, whereas neem oil showed no or little change in the rate of degradation of azadirachtin-A. None of these fatty acids and fatty oils were effective in controlling the rate of degradation of azadirachtin-A under UV-light as thin film.

Fatty Acids↗
PubMed2000

Effect of human immunodeficiency virus infection on episodes of diarrhea among children in South Africa.

BACKGROUND: Infection with HIV is increasing among children in South Africa. Diarrhea is a common cause of morbidity and mortality in Africa, and some studies have shown that HIV-infected children have episodes of severe diarrhea with higher mortality than HIV-uninfected children. OBJECTIVES: To compare the severity, pathogens and outcome of diarrhea in HIV-infected and uninfected children. METHODS: We studied 181 children ages 3 months to 4 years admitted for gastroenteritis to the Chris Hani Baragwanath Hospital in Soweto, South Africa. Demographic details of the children were recorded, as were the details of the episode of diarrhea. Stools specimens were collected and sent for microbiologic evaluation. The clinical course of the child's admission was recorded. Children were diagnosed as being infected with HIV if they tested positive by HIV enzyme-linked immunosorbent assay (ELISA) and were >15 months of age, or if they were ELISA-positive, were < 15 months of age and had clinical signs of HIV infection. RESULTS: Of the 176 children with an HIV ELISA result, 31 (17.6%) were classified as HIV-infected. More HIV-infected children were malnourished (80.6% vs. 39.5%, P < 0.001) and more likely to have had prolonged diarrhea (16.1% vs. 5.9%, P = 0.07) compared with HIV-uninfected children. HIV-infected children had a higher rate of a codiagnosis of pneumonia (43.3% vs. 9.2%, P < 0.0001) and were more likely to require a hospital stay of >4 days (prevalence odds ratio, 5.11; 95% confidence interval, CI 1.49 to 17.52). There were no significant differences in stool pathogens or in the level of dehydration on admission between the HIV-infected and uninfected children. CONCLUSION: HIV-infected children have the same spectrum of enteric pathogens as uninfected children but require more attention because of malnutrition and comorbidity.

Breast Feeding↗
PubMed2000

The "coming of age" of couple therapy: a decade review.

This article overviews significant developments in couple therapy over the last decade. Key trends include: (1) couple therapy becoming firmly established as the accepted treatment of choice for couple problems, (2) the blossoming of the science of relationships, (3) strong evidence supporting the effectiveness of couple therapy both for relationship problems and DSM disorders, (4) greater understanding of the ramifications of gender, (5) new respect for the diversity of family forms, (6) increased accent on the role of emotion, (7) the influence of postmodernism, (8) greater recognition of couple violence, and (9) the move toward integration across models of treatment.

Couples Therapy↗
PubMed2000

Toxin gene analysis of a variant strain of Clostridium difficile that causes human clinical disease.

A toxin variant strain of Clostridium difficile was isolated from two patients with C. difficile-associated disease (CDAD), one of whom died from extensive pseudomembranous colitis. This strain, identified by restriction endonuclease analysis (REA) as type CF2, was not detected by an immunoassay for C. difficile toxin A. Culture supernatants of CF2 failed to elicit significant enterotoxic activity in the rabbit ileal loop assay but did produce atypical cytopathic effects in cell culture assay. Southern hybridization, PCR amplification, and DNA sequence analyses were performed on the toxin A (tcdA) and toxin B (tcdB) genes of type CF2 isolate 5340. Type CF2 5340 tcdA exhibited a 1,821-bp truncation, due to three deletions in the 3' end of the gene, and a point mutation in the 5' end of the gene, resulting in a premature stop codon at tcdA position 139. Type CF2 5340 tcdB exhibited multiple nucleotide base substitutions in the 5' end of the gene compared to tcdB of the standard toxigenic strain VPI 10463. Type CF2 5340 toxin gene nucleotide sequences and deduced amino acid sequences showed a strong resemblance to those of the previously described variant C. difficile strain 1470, a strain reported to have reduced pathogenicity and no association with clinical illness in humans. REA of strain 1470 identified this strain as a distinct type (CF1) within the same REA group as the closely related type CF2. A review of our clinical-isolate collection identified five additional patients infected with type CF2, three of whom had documented CDAD. PCR amplification of the 3' end of tcdA demonstrated identical 1. 8-kb deletions in all seven type CF2 isolates. REA type CF2 is a toxin variant strain of C. difficile that retains the ability to cause disease in humans but is not detected in clinical immunoassays for toxin A.

Aged↗