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Biomedical subjects

K Hood

Publications and source records attributed to K Hood.

50 records · Page 3Linked to original sources
PubMed1988

Prevention of gallstone recurrence by non-steroidal anti-inflammatory drugs.

In laboratory animals, non-steroidal anti-inflammatory drugs (NSAIDs) are reported to inhibit diet-induced gallstone formation. To see if these drugs had a similar effect in man, 82 patients who had taken part in a comparison of ursodeoxycholic acid, placebo, and diet for prevention of gallstone recurrence were sent questionnaires about their use of NSAIDs during the period of the trial. 75 replied. After a mean follow-up of 33 (SEM 4) months none of the 12 regular users of NSAIDs had had gallstone recurrences, compared with 20 of the 63 who never or rarely used these drugs (p less than 0.02).

Adult↗
PubMed1979

Circular-dichroism studies of ligand binding to dihydrofolate reductase from Lactobacillus casei MTX/R.

Circular-dichroism spectra (200--450 nm) were recorded for Lactobacillus casei MTX/R dihydrofolate reductase and its complexes with substrates, inhibitors and coenzymes. These spectra are compared with those reported by others for dihydrofolate reductase from other sources. The binding of NADP+ or NADPH is associated with the perturbation of one or more aromatic amino acid residues, and there is marked enhancement of the negative c.d. band at 340 nm arising from the dihydronicotinamide chromophore of NADPH. The substrates folate and dihydrofolate give rise to substantial extrinsic c.d. bands on binding, which show a number of specific differences between enzymes from different sources. The binary complexes between the enzyme and the inhibitors methotrexate or trimethoprim also show strong c.d. bands, and these are qualitatively very similar for all dihydrofolate reductases studied so far. The ternary complexes between enzyme, NADPH and trimethoprim or methotrexate are very different from the sum of the spectra of the binary complexes. Trimethoprim leads to the disappearance of the 340 nm c.d. band of bound NADPH, whereas in the methotrexate--NADPH--enzyme ternary complex a "couplet" c.d. spectrum is observed at long wavelengths. Analysis of this latter feature suggests that it arises from a direct interaction between the dihydronicotinamide and pteridine rings in the ternary complex.

Circular Dichroism↗
PubMed1978

Ultraviolet difference-spectroscopic studies of substrate and inhibitor binding to Lactobacillus casei dihydrofolate reductase.

The u.v. difference spectra generated when methotrexate, trimethoprim or folate bind to Lactobacillus casei dihydrofolate reductase were analysed. The difference spectrum producted by methotrexate binding is shown to consist of three components: (a) one closely resembling that observed on protonation of methotrexate, reflecting an increased degree of protonation on binding; (b) a pH-independent contribution corresponding to a 40 nm shift to longer wavelengths of a single absorption band of methotrexate: (c) a component arising from perturbation of tryptophan residue(s) of the enzyme. Quantitative analysis of the pH-dependence of component (a) shows that pK of methotrexate is increased from 5.35 to 8.55 (+/-0.10) on binding. In contrast, folate is not protonated when bound to the enzyme at neutral pH. At pH7.5, where methotrexate is bound 2000 times more tightly than folate, one-third of the difference in binding energy between the two compounds arises from the difference in chaarge stage. A similar analysis of the difference spectra generated on trimethoprim binding demonstrates that this compound, too, shows an increase in pK on binding but only from 7.22 to 7.90 (+/-0.10), suggesting that its 2,4-diaminopyrimidine ring does not bind to the enzyme in precisely the same way as the corresponding moiety of methotrexate.

Folic Acid↗
PubMedDate not supplied

Interferon-gamma or granulocyte-macrophage colony-stimulating factor administered as adjuvants with a vaccine of irradiated autologous tumor cells from short-term cell line cultures: a randomized phase 2 trial of the cancer biotherapy research group.

The objective was to study the effects of patient-specific vaccine immunotherapy administered with either interferon-gamma (IFNgamma) or granulocyte-macrophage colony stimulating factor (GM-CSF) in patients with metastatic cancer. Short-term cell lines were established from cancer tissue resected from patients with metastatic cancer for use as autologous tumor cell vaccines. Successful cultures were expanded to 1 to 2 x 108 cells, irradiated, and cryopreserved in aliquots of 106 cells for intradermal testing of delayed tumor hypersensitivity and 107 cells for subcutaneous vaccinations. The study design was that of a randomized phase 2 trial. Patients were stratified by tumor type and by whether they had measurable disease at the time vaccination was to commence, and then randomized to receive either 100 MIU IFNgamma subcutaneously or 500 microg GM-CSF subcutaneously at the time of each tumor cell vaccination. Following a baseline test of delayed-type hypersensitivity (DTH) to an intradermal injection of 106 irradiated autologous tumor cells, patients received 3 weekly subcutaneous injections of 107 cells, had a repeat DTH test at week 4, then received monthly vaccinations for 5 months. A positive DTH test was defined as at least 10 mm of induration; survival was determined from the first DTH test. There were 98 patients enrolled with a median follow-up of over 4 years. The most prevalent diagnoses were melanoma (51), renal cell carcinoma (18), and soft-tissue sarcoma (14). There were 49 patients (26 men, 23 women, average age 50.4 years) randomized to IFNgamma and 49 (28 men, 21 women, average age 54.1 years) to GM-CSF. The average numbers of vaccine and adjuvant injections were 6.3 and 5.9, respectively. For the patients who received IFNgamma, the objective response rate was 0 of 21; for patients who received GM-CSF the response rate was 1 of 26. Only eight patients (four from each arm) had a positive baseline DTH reaction to autologous tumor. The tumor DTH test converted from negative to positive in 13 of 45 of the IFNgamma group and 11 of 43 of the GM-CSF group. With 29 patients deceased in the IFNgamma arm and 31 in the GM-CSF arm, the 2-year and 5-year survival rates were 45% and 29% for the IFNgamma arm and 41% and 23% for the GM-CSF arm (NSD). Both adjuvants were well tolerated and results were similar in both arms of the study. Both adjuvants were associated with a 25% to 30% rate of DTH conversion and a 25% 5-year survival rate. Immune recognition of autologous tumor can be induced with this approach.

Adjuvants, Immunologic↗
PubMedDate not supplied

The effectiveness of one-to-one risk communication interventions in health care: a systematic review.

OBJECTIVES: To assess whether risk-communication interventions are associated with changes in patient knowledge, attitudes, and behaviors, and to identify aspects of these interventions that modify these effects. DESIGN: Systematic review. DATA SOURCES: 96 studies from the period 1985-1996 retrieved by electronic searching of eight databases, hand searching of four journals, contacting key authors, and reference list searching. MAIN OUTCOME MEASURES: The effect size of the principal outcome was identified from each study. Outcomes measuring behavioral change were preferred; if these were not available, knowledge, anxiety, or risk perceptions were used, according to the focus of the study. Data were available to calculate the principal effect sizes for 82 of the studies. ANALYSIS: Meta-regression. RESULTS: The methodologic qualities of the studies varied. Nevertheless, risk-communication interventions generally had positive (beneficial) effects. Interventions addressing treatment choices were associated with larger effects than were those in other contexts, such as prevention or screening. Interventions using individual risk estimates were associated with larger effects than were those using more general risk information. Two design variables were identified as effect modifiers: randomized controlled trials were associated with smaller effects than other designs, and dichotomous outcomes were associated with larger effects than continuous outcomes. CONCLUSIONS: Risk communication interventions may be most productive if they include individual risk estimates in the discussion between professional and patient. Patient decisions about treatment appear more amenable to change by these interventions than attendance for screening or modification of risky behavior.

Communication↗
PubMedDate not supplied

A falls risk-assessment tool in an elderly care environment.

Falls are a major cause of morbidity and mortality among older people. In an inpatient setting it has been suggested that the introduction of risk-assessment tools may be an important way of managing the issue. The study reported in this article was carried out in two stages. First, fall incidents were identified retrospectively using 'falls incident forms' and nursing notes, and the characteristics and management of patients who had fallen were compared with those who had not fallen. A risk-assessment tool and care plan were developed and evaluated prospectively. By analysing the data in stage one it was found that falls incidence reporting was poor and patients who had fallen had more evidence of previous falls than those who had not fallen. In stage two staff found the risk-assessment tool and care plan easy to complete; however, there was little documentation about whether any appropriate interventions, specific to the individuals' risk score, were carried out. Appropriate interventions identified on the risk-assessment tool were put into place inconsistently. As a result of this work the hospital has set up a multidisciplinary group to look at falls management.

Accidental Falls↗