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Biomedical subjects

A Jones

Publications and source records attributed to A Jones.

At least 361 records · Page 20Linked to original sources
PubMed1996

The Q-switched ND:YAG laser effectively treats tattoos in darkly pigmented skin.

BACKGROUND: Laser therapy for removal of cosmetic tattoos has been proven efficacious in lighter skin. Few studies have been reported using the Q-switched neodymium-yttrium-aluminum-garnet (Nd:YAG) laser to treat tattoos in darkly pigmented or type VU skin, however. OBJECTIVE: To report results using the Q-switched Nd:YAG laser to remove tattoos from type VI skin. METHODS: Eight darkly pigmented patients had 15 amateur tattoos treated with the Q-switched Nd:YAG laser. Treatments numbered three or four on average and were given at 8-week intervals. Results were rated by the patients and by a panel of four physicians. RESULTS: Eight of 15 tattoos were rated as 75-95% cleared after therapy. Another five tattoos were 50% cleared. Two tattoos were only 25% cleared, but underwent only two treatments. None of the patients reported any changes in texture of their skin post therapy. Thirteen of 15 tattoos were removed without any change in the color of the involved skin. The other two tattoos were removed with only slight lightening of the skin. CONCLUSION: When treating patients in whom there is a significant risk for keloid scarring or destruction of natural pigment as a consequence of tattoo removal, the Q-switched Nd:YAG laser appears to be an excellent choice of therapy.

Humans↗
PubMed1996

The Symptom Questionnaire: British standardization data.

The Symptom Questionnaire is a simple and quick measure of emotional state; previous work has indicated that the Questionnaire has good reliability and validity. However the original sample on which it was based was small, and exclusively North American. Data from a large sample (N = 707) of British psychiatric in-patients, out-patients, day hospital attenders, and a non-patient population sample are presented. Consistent differences between the patient and non-patient samples were obtained on the scales, with a few exceptions; there were no significant differences due to sex.

Affect↗
PubMed1996

Enzymatic pathway for the bacterial degradation of the cyanobacterial cyclic peptide toxin microcystin LR.

An isolated bacterium, identified as a new Sphingomonas species, was demonstrated to contain a novel enzymatic pathway which acted on microcystin LR, the most common cyanobacterial cyclic peptide toxin. Degradation of microcystin LR was mediated by at least three intracellular hydrolytic enzymes. The use of classic protease inhibitors allowed (i) the classification of these enzymes into general protease families and (ii) the in vitro accumulation of otherwise transient microcystin LR degradation products. The initial site of hydrolytic cleavage of the parent cyclic peptide by an enzyme that we designate microcystinase is at the 3-amino-9-methoxy-2,6,8-trimethyl-10-phenyl-deca-4,6-dienoic acid (Adda)-Arg peptide bond. Two intermediates of microcystin LR enzymatic degradation have been identified; one is linearized (acyclo-) microcystin LR, NH2-Adda-Glu(iso)-methyldehydroalanine-Ala-Leu-beta-methylas partate-Arg-OH, and the other is the tetrapeptide NH2-Adda-Glu(iso)-methyldehydroalanine-Ala-OH. The intermediate degradation products were less active than the parent cyclic peptide; the observed 50% inhibitory concentrations for crude chicken brain protein phosphatase were 0.6 nM for microcystin LR, 95 nM for linear LR, and 12 nM for the tetrapeptide. These linear peptides were nontoxic to mice at doses up to 250 micrograms/kg. Ring opening of the potent hepatotoxin microcystin LR by bacterial microcystinase effectively renders the compound nontoxic by dramatically reducing the interaction with the target protein phosphatase.

Amino Acid Sequence↗
PubMed1996

A Combined Model for Growth and Subsequent Thermal Inactivation of Brochothrix thermosphacta.

A mathematical technique for integrating growth and thermal inactivation models of microorganisms into a smooth combined model that can be applied to circumstances under which the temperature gradually rises from growth to inactivation regions is described. For the death part of the model, a correction term is introduced to allow for additional resistance of the cells gained during slow heating. The model was validated with Brochothrix thermosphacta heated in broth at rising temperatures.

Journal Article↗
PubMed1996

CD40 ligand deficiency presenting as unresponsive neutropenia.

A male child presented with recurrent respiratory infections, otitis media, and oral ulceration and was found to be neutropenic. Investigations showed hypogammaglobulinaemia with normal serum IgM and a novel deletion in the gene for CD40 ligand on his X chromosome. Intravenous gammaglobulin did not lead to resolution of his neutropenia; G-CSF was also necessary.

Agammaglobulinemia↗
PubMed1996

X linked agammaglobulinaemia with a 'leaky' phenotype.

Typical X linked agammaglobulinaemia (XLA) is characterised by absence of immunoglobulin production and lack of mature B cells. The gene responsible for XLA has recently been identified, and codes for a B cell tyrosine kinase, BTK. A family affected by a B cell immunodeficiency, which is less severe than classical XLA, is described but they had a pedigree suggestive of X linked inheritance. Demonstration of a mutation in the BTK gene confirms that this is a mild form of XLA.

Agammaglobulinemia↗
PubMed1996

Intravenous immunoglobulin, splenectomy, and antibiotic prophylaxis in Wiskott-Aldrich syndrome.

AIM: To assess the results of supportive treatment with intravenous immunoglobulin (IVIG) and antibiotic prophylaxis in combination with splenectomy in patients with Wiskott-Aldrich syndrome. STUDY DESIGN: Retrospective review of case records of 21 patients from March 1984 to February 1996. RESULTS: Thrombocytopenia was cured in 14 of 15 patients who had splenectomy, but it recurred intermittently in three. Mean platelet volume (MPV) was normal transiently in some patients, but all MPV values were subnormal 8-23 months after splenectomy. Antibiotic and IVIG prophylaxis may have contributed to the lack of a detectable increase in the number of severe acute bacterial infections in the 451 months after splenectomy. Four patients died in 2205 months of observation before and after splenectomy (median 82, range 16-248): two of cerebral B cell lymphoma, one of progressive multifocal leucoencephalopathy, and one with severe chronic chest disease of pneumonia. CONCLUSION: Adequate supportive treatment with IVIG and antibiotic prophylaxis together with splenectomy enables good survival and quality of life in the short and medium term in patients with Wiskott-Aldrich syndrome. Persistence of infection, bleeding, and vasculitic and allergic symptoms in a significant minority and the risk of development of lymphoma, however, suggest that bone marrow transplantation may be indicated if an HLA identical donor is available.

Anti-Bacterial Agents↗
PubMed1996

Intra-articular corticosteroids are effective in osteoarthritis but there are no clinical predictors of response.

OBJECTIVES: To show whether intra-articular steroid injections are effective in osteoarthritis; to determine factors that predict response; and to determine whether injection has a beneficial effect on muscle strength. METHODS: Double blind, placebo controlled, crossover study in 59 patients with symptomatic osteoarthritis of the knee. Outcome measure-Primary outcome measure: change in visual analogue score for pain at three weeks. Predictors of response analysed using logistic regression with a 15% decrease in pain score at three weeks defining response. RESULTS: Intra-articular methyl prednisolone acetate produced a significant reduction in visual analogue pain score at three weeks compared to both baseline (median change -2.0 mm, interquartile range -16.25 to 4.0) and placebo (median 0.0 mm, interquartile range -9.0 to 6.25). No clinical predictors of response could be identified. Muscle strength was not significantly improved in the short term by intra-articular injection. CONCLUSIONS: Intra-articular corticosteroids are effective for short term relief of pain in osteoarthritis but predicting responders is not possible. There may be a place for their more widespread use.

Aged↗
PubMed1996

Assessing progression of patellofemoral osteoarthritis: a comparison between two radiographic methods.

OBJECTIVE: To compare two plain radiographic methods for sensitivity to detect progression of patellofemoral osteoarthritis. METHODS: Two sets of paired skyline and lateral knee radiographs from 54 hospital referred patients (108 knees) with knee osteoarthritis were taken an average of 31 months apart (range 12-40). Films were examined separately in random order by a single observer blind to patient identity and time order. Minimum joint space was measured by metered caliper; individual features of osteoarthritis were graded 0-3 using an atlas. RESULTS: Intraobserver reproducibility assessed on 40 knees was to within +/- 0.5 mm for skyline lateral facet and +/- 0.7 mm for medial facet and lateral views. On the lateral view measured joint space decreased in 51% of knees but increased in 43%, with overall no significant mean group change with time (-0.2 mm, 95% confidence interval, 0.1 to -0.5). By contrast on the skyline view joint space decreased in at least one facet in 71% of knees, with significant decrease in mean joint space for both lateral facets (-0.4 mm, 95% CI, -0.2 to -0.6) and medial facets (-0.5 mm, 95% CI, -0.1 to -0.8). CONCLUSIONS: It is possible to detect significant joint space loss with time on the skyline view that is not apparent on the lateral view. The skyline view should be the method of choice to detect progression of patellofemoral osteoarthritis.

Adult↗
PubMed1996

Association between synovial fluid levels of inorganic pyrophosphate and short term radiographic outcome of knee osteoarthritis.

OBJECTIVE: To test the hypothesis that high concentrations of extracellular inorganic pyrophosphate (PPi), which associate with increased cell synthesis and turnover in cartilage, may act as a marker for structural outcome in knee osteoarthritis (OA). METHOD: One hundred and thirty five consecutive patients referred to hospital with knee OA (59 men, 76 women; mean age 71 years, range 41-88) were followed prospectively for a median of 2.5 years (interquartile range 1.75-3.0). Synovial fluid (SF) aspirated at presentation (202 OA knees: 68 bilateral, 66 unilateral) was assessed for PPi content by radiometric assay. Knee radiographs at presentation and at final review were assessed for change in global (Kellgren) and individual features (narrowing, osteophyte, sclerosis, cyst, attrition) of OA. RESULTS: The median SF PPi level was 10.5 mumol (range 0.07-72.4). At baseline, high PPi was significantly associated with presence of calcium pyrophosphate crystals, chondrocalcinosis, and bone attrition. Radiographic change was observed in 164 knees. High PPi levels were negatively associated with change in Kellgren and Lawrence grade, further narrowing, and increase in osteophyte, but positively associated with development of attrition. In the 68 patients from whom bilateral data were obtained, there was correlation between right and left knees for PPi levels, all baseline radiographic scores, and changes in radiographic features. Multiple logistic regression analysis for PPi as a continuous variable (age, gender, and patient number included in model) showed a negative correlation with change in global Kellgren and Lawrence grade (odds ratio (OR) 0.97, 95% confidence interval (CI) 0.95 to 0.99) and a positive correlation with attrition (OR 1.04, 95% CI 1.02 to 1.07). CONCLUSION: High SF levels of PPi are associated with favourable radiographic outcome in terms of progressive change in Kellgren grade. Such elevated PPi levels, however, may inhibit new bone formation and remodelling in knee OA.

Adult↗
PubMed1996

Estimation of bladder volume using portable ultrasound in clam enterocystoplasty patients.

PURPOSE: We evaluated portable ultrasound for the measurement of residual volume following clam enterocystoplasty. MATERIALS AND METHODS: Bladder volumes were measured in 25 clam enterocystoplasty patients using a portable ultrasound machine and compared with urethral catheter volumes. A similar study was performed on a control group of 50 patients with normal bladder architecture. RESULTS: There was a close correlation (r = 0.978) between ultrasound and catheter volumes in the control group with a regression line slope of 0.88. There was an equally close correlation (r = 0.960) in the clam enterocystoplasty group but the regression line slope was lower at 0.65, which suggests an underestimation of the true bladder volume. There was a significant difference (p < 0.0001) between the ultrasound-to-catheter volume ratio in the 2 groups. CONCLUSIONS: Portable ultrasound is inaccurate for the measurement of residual bladder volume in clam enterocystoplasty patients.

Case-Control Studies↗
PubMed1996

Sensitive, specific quantitative analysis of tacrolimus (FK506) in blood by liquid chromatography-electrospray tandem mass spectrometry.

The capacity of liquid chromatography-tandem mass spectrometry (LC-MS2) to detect and define individual components in a complex mixture has been utilized to develop a quantitative assay of the potent immunosuppressant drug, tacrolimus. Trough blood concentrations were measured in 175 samples obtained over several weeks after liver transplantation from seven patients. The assay was linear over the range of 0.2 to 100 micrograms/L. Imprecision was <8%, and accuracy was 99-101%. The turnaround time for a batch of 20 samples was 2.5 h. No interference from any of the other drugs being administered to the patients was evident. An ELISA also performed on the same samples overestimated the concentrations substantially, as indicated by a plot of the difference between the results for the two methods vs their mean. The favorable characteristics of the LC-MS2 assay, especially its sensitivity and specificity, will facilitate detailed pharmacokinetic studies of tacrolimus, particularly under circumstances in which metabolism is perturbed by either hepatic dysfunction or drug interactions.

Animals↗
PubMed1996

Pilot study of low dose oral methotrexate treatment for primary biliary cirrhosis.

OBJECTIVE: To assess the efficacy of low doses of oral methotrexate as therapy for primary biliary cirrhosis. METHODS: Ten symptomatic patients with this disease were treated with methotrexate at a dose of 15 mg/wk in an open label trial. RESULTS: Eight patients completed 1 yr of treatment and six completed 2. Pruritus and fatigue decreased in all patients treated for at least 1 yr. Mean levels of serum alkaline phosphatase, ALT, and IgM were less at 1 and 2 yr than corresponding baseline means. Total serum bilirubin increased in three patients during treatment. Serum aminotransferases and alkaline phosphatase became normal in one patient with stage I disease. Although liver biopsies at 1 and 2 yr revealed a decrease in the intensity of the inflammatory infiltrate, they also showed an increase in fibrosis suggestive of disease progression. Methotrexate was discontinued in five patients: for disease progression in four (one at 4 months, one at 1 yr, and two at 2 yr) and for intractable pruritus in one (at 4 months). All patients experienced transient mucositis and intermittent dyspepsia. CONCLUSIONS: These findings suggest that methotrexate treatment in patients with primary biliary cirrhosis is not beneficial in patients with advanced disease; in patients with early disease, methotrexate may be associated with amelioration of symptoms, reduction in serum biochemical indices of liver disease, and reduction in hepatic inflammation. However, prospective, randomized controlled trials will be necessary for definitive evaluation of the effects of methotrexate on the quality of life and survival of patients with primary biliary cirrhosis.

Adult↗
PubMed1996

The National Home and Hospice Care Survey: 1993 summary.

Data collected in the 1993 National Home and Hospice Care Survey are presented in 61 tables according to standard sets of descriptive variables. The tables on patients are grouped into four categories: home health care current patients, home health care discharges, current hospice care patients, and hospice care discharges. Data are presented on agency characteristics, demographic characteristics, utilization measures, and health and functional status of current patients and discharges.

Adolescent↗
PubMed1996

Assessing reading level of drug users for HIV and AIDS prevention purposes.

Using the short form of the Woodcock Reading Mastery Test-Revised and the reading subtest of the Wide Range Achievement Test-Revised, the reading abilities of 284 male and 128 female drug users from five sites across the United States were evaluated. All subjects were participants in a National Institute on Drug Abuse HIV/AIDS prevention project aimed at intravenous drug users and cocaine smokers. Results revealed differences in reading abilities among ethnic groups with Native and white subjects having significantly higher reading levels than Hispanic and black subjects. Significant site differences were revealed, with mean grade equivalent scores ranging from 2.7 to 10.1 grades. Across all subjects, the average grade equivalent reading level was 5.8 to 7.7, indicating that the subjects read below the level of 81.5% to 93% of the general population. We provide implications for development of educational materials that are accessible for this population.

Adult↗
PubMed1995

Self directed learning in the undergraduate dental curriculum.

An evaluation of self-directed learning (SDL) in the clinical curriculum was undertaken at the Dental School of the London Hospital Medical College in 1995. Surveys of staff and students produced evidence of variation in viewpoint within and between groups concerning what the term means and how valuable a tool for learning it is. Lack of clarity of definition and purpose of SDL in General Dental Council guidance is highlighted and linked to the desirability of giving further consideration to SDL.

Analysis of Variance↗