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Biomedical subjects

S Morris

Publications and source records attributed to S Morris.

At least 73 records · Page 4Linked to original sources
PubMed2000

Reversal of caffeine withdrawal by ingestion of a soft beverage.

Followlng regular use, acute cessation of caffeine is associated with a characteristic withdrawal syndrome. Despite this, caffeine remains popular with its consumers. The aim of this study was to examine the physiologic and psychologic effects of small caffeine doses, administered in the form of a market-leading soft drink, on healthy women who were acutely withdrawn from caffeine. After 48-h abstinence and overnight fast, 11 healthy (22 to 40 years) female volunteers, all regular caffeine users (daily consumption 143 to 773 mg) consumed using a double-blind. randomized, controlled cross-over design either 2 tins of regular or caffeine-free Diet Coke. On both visits a Mars bar was eaten to prevent hypoglycaemia. Thus, the caffeine load was 76 or 10 mg respectively. Following ingestion of regular Diet Coke, there was a l0% fall in middle cerebral artery velocity (95% CI [6%-l4%], p < 0.005 versus caffeine free) and improvement in feelings of pleasure (p < 0.046) and energy (p < 0.037). Intellectual function (4-choice reaction time) was unaffected by caffeine status. On both visits, ingestion of Diet Coke induced a pressor response (maximum rise in systolic pressure +15+/- 2 mm Hg with caffeine and +l2 +/- 2 mm Hg with caffeine-free beverage, both p < 0.001 compared with baseline). In conclusion, in women acutely withdrawn from caffeine, ingestion of a popular soft beverage containing modest amounts of caffeine is associated with demonstrable physiologic and psychologic effects.

Adult↗
PubMed2000

Use of complementary and alternative medicine among Dominican emergency department patients.

This small, pilot study examined presenting complaint, brief health history, use of complementary and alternative medicine (CAM), and sociodemographic characteristics, among patients attending the emergency department (ED) of a large urban hospital. The sample (n = 50) was primarily Dominican and of low socioeconomic status. Almost half had used CAM for their presenting complaint or another health problem during the past year, most commonly in the form of medicinal plants made into herbal teas. CAM users were more likely to be female, longer-term residents of the United States, and to have also used religious practices for health problems. Subjects who had used CAM for any problem other than the presenting complaint during the past year rated its effectiveness higher than subjects who had used CAM for their presenting complaint. In conclusion, it is likely that a significant proportion of Dominican ED patients use CAM, suggesting that they should be asked about their CAM use during triage.

Adult↗
PubMed2000

Where are the economic guidelines coming from?

Economic guidelines recommend methods that should be employed in conducting economic evaluations of healthcare programs. The nature of the efficiency or equity goal underpinning economic guidelines is unclear. What is also unclear is how the methods recommended in the guidelines are linked to the underlying efficiency or equity goal being targeted. If it is unclear what efficiency/equity objectives are being pursued, then it is unlikely that even full implementation of economic guidelines will improve resource allocation.

Cost Control↗
PubMed2000

Accelerated age-related decline in processing resources in schizophrenia: evidence from pupillary responses recorded during the span of apprehension task.

Cognitive impairment in schizophrenia may be related to reduced availability of information-processing resources (resource limitations hypothesis). An abnormally accelerated age-related decline in processing resource availability may also occur in older patients with schizophrenia (neurodegeneration hypothesis). To test these hypotheses, pupillary responses were recorded as an index of processing resource availability during performance of the span of apprehension (SOA) task in 33 middle-aged and older patients with schizophrenia and 37 age-comparable nonpsychiatric participants. Consistent with the resource-limitations hypothesis, the patients with schizophrenia showed impaired detection accuracy and abnormally small pupillary responses (reduced resource allocation) only in the higher processing load SOA conditions. This pattern of results suggests that the patients depleted their available processing resources at lower processing loads than the nonpsychiatric participants. Consistent with the neurodegeneration hypothesis, cross-sectional analyses showed abnormally accelerated rates of age-related decline in SOA performance and pupillary responses in the patients with schizophrenia relative to age-comparable normal participants.

Age Factors↗
PubMed2000

Chromosome analysis of workers occupationally exposed to radiation at the Sellafield nuclear facility.

PURPOSE: To investigate the relationship between stable chromosome aberration frequency in peripheral blood lymphocytes and occupational cumulative radiation exposure. MATERIALS AND METHODS: Cytogenetic analysis using G-banding was performed on peripheral blood lymphocyte cultures from 104 workers from the British Nuclear Fuels PLC facility at Sellafield, UK. The study group comprised 61 men with lifetime cumulative doses > 500 mSv, 39 men with minimal exposure (i.e. < 50 mSv) who formed a control group and 4 men with intermediate doses. RESULTS: The slope of the dose-response, adjusted for smoking status, for translocations and insertions was 0.55+/-0.31 x 10(-2)/cell/Sv. Consideration of chromosome breakpoints for all aberrations combined in the radiation workers revealed an excess in the C group chromosomes and a deficit in the F group chromosomes with breakpoints being concentrated in the terminal regions whereas the distribution in the control group did not deviate from expectation. CONCLUSIONS: The dose-response was not significantly different from the parallel FISH analysis (Tucker et al. 1997) and confirms that chronic radiation exposure appears to be substantially less effective at inducing stable chromosome aberrations in comparison with acute exposure.

Adult↗
PubMed2000

Outcome after musculoskeletal trauma treated in a regional hospital.

BACKGROUND: Trauma remains the leading cause of death and morbidity in the under-35-year-old population. The majority of reports assessing outcome after trauma emanate from North American Level I trauma centers. We sought to examine outcome after trauma treated in an Irish regional unit. METHODS: All patients admitted over a 1-year period with an Injury Severity Score > or =9 were evaluated and 61 patients recruited to the study. Demographic data, medical history, and details of the mechanism and pattern of injury and treatment were collected. Patients' functional outcome was assessed using the Sickness Impact Profile (SIP), duration of hospital stay, and return to work. RESULTS: Significant residual disability was noted (mean SIP 13.63+/-14.60). Thirty-seven percent of patients had not returned to work despite a mean follow-up of 18.36 months. Factors associated with a poor outcome include increasing age, a blue-collar occupation, lower limb fractures, comorbid conditions, and the presence of complications. CONCLUSION: Optimizing primary care of the trauma victim may help to minimize consequent morbidity. A small group of patients suffer permanent disability, and vocational retraining opportunities should be made available to them.

Accidental Falls↗
PubMed2000

Levonorgestrel-releasing (20 microgram/day) intrauterine systems (Mirena) compared with other methods of reversible contraceptives.

OBJECTIVE: To assess the relative contraceptive effectiveness, tolerability and acceptability of the levonorgestrel-releasing (20 microg per day) intrauterine system (LNG-20) compared with reversible contraceptive methods in women of reproductive age. DESIGN: A systematic review and meta-analysis of randomised controlled trials. IDENTIFICATION: Studies were identified through seven databases, and by contacting investigators and organisations working in the contraceptive field. MAIN OUTCOME MEASURES: Unplanned pregnancy and continuation of contraceptive method. RESULTS: Five of the seven randomised controlled trials which met the inclusion criteria were included in the meta-analyses; four were comparisons of the LNG-20 intrauterine system with nonhormonal intrauterine devices. LNG-20 intrauterine systems were compared with intrauterine devices divided into two categories, those > 250 mm3 (Copper T 380 Ag and Copper T 380A intrauterine devices) and those < or = 250 mm3 (Nova-T, Copper T 220C and Copper 200 intrauterine devices). Pregnancy rates for the LNG-20 intrauterine system users were significantly less likely to become pregnant compared with users of intrauterine devices < or = 250 mm3, and significantly less likely to have an ectopic pregnancy. LNG-20 intrauterine system users were more likely to experience amenorrhoea and device expulsion than women using intrauterine devices > 250 mm3. LNG-20 intrauterine system users were significantly more likely than all the intrauterine device users to discontinue because of hormonal side effects and amenorrhoea. When the LNG-20 intrauterine system was compared with Norplant-2, the LNG-20 users were significantly more likely to experience oligo-amenorrhoea, but significantly less likely to experience prolonged bleeding and spotting. CONCLUSIONS: The effectiveness of the LNG-20 intrauterine system was similar to or better than other contraceptive methods with which it was compared. Amenorrhoea was the main reason for the discontinuation of the LNG-20 intrauterine system, usually unnecessarily, since this end-organ suppression of bleeding is benign, associated with normal oestrogen levels. Women choosing this method should be informed of potential amenorrhoea when having pre-contraceptive counselling and that absent bleeding may be viewed as a positive outcome.

Contraception↗
PubMed2000

Discovery of novel antifungal (1,3)-beta-D-glucan synthase inhibitors.

The increasing incidence of life-threatening fungal infections has driven the search for new, broad-spectrum fungicidal agents that can be used for treatment and prophylaxis in immunocompromised patients. Natural-product inhibitors of cell wall (1,3)-beta-D-glucan synthase such as lipopeptide pneumocandins and echinocandins as well as the glycolipid papulacandins have been evaluated as potential therapeutics for the last two decades. As a result, MK-0991 (caspofungin acetate; Cancidas), a semisynthetic analogue of pneumocandin B(o), is being developed as a broad-spectrum parenteral agent for the treatment of aspergillosis and candidiasis. This and other lipopeptide antifungal agents have limited oral bioavailability. Thus, we have sought new chemical structures with the mode of action of lipopeptide antifungal agents but with the potential for oral absorption. Results of natural-product screening by a series of newly developed methods has led to the identification of four acidic terpenoid (1,3)-beta-D-glucan synthase inhibitors. Of the four compounds, the in vitro antifungal activity of one, enfumafungin, is comparable to that of L-733560, a close analogue of MK-0991. Like the lipopeptides, enfumafungin specifically inhibits glucan synthesis in whole cells and in (1,3)-beta-D-glucan synthase assays, alters the morphologies of yeasts and molds, and produces a unique response in Saccharomyces cerevisiae strains with point mutations in FKS1, the gene which encodes the large subunit of glucan synthase.

Antifungal Agents↗
PubMed2000

Adaptations to a terrestrial existence in the robber crab Birgus latro L. IX. Hormonal control of post-renal urine reprocessing and salt balance in the branchial chamber.

The terrestrial robber crab Birgus latro L. regulates the composition of its final excretory product (termed P) depending on the availability of dietary salt by reabsorbing ions from urine passed over the gills. Laboratory and field-based studies investigated the nature of the mechanisms of control of this branchial ion uptake. B. latro were prepared such that their branchial chambers could be perfused with artificial urine, and the rate of ion transport from the artificial urine was determined. For B. latro acclimated to drinking fresh water, the rates of Na(+) and Cl(-) uptake were more than four times those of crabs drinking 70 % sea water. Crabs were injected with either saline carrier or the same solution containing either dopamine or dibutyryl cyclic AMP (db-cAMP) (final concentration 8.7x10(-)(7 )mol l(-)(1 )haemolymph). Dopamine and db-cAMP inhibited Na(+) and Cl(-) uptake in animals acclimated to fresh water and markedly reduced their gill Na(+)/K(+)-ATPase activity. Dopamine stimulated the production of cyclic AMP within the branchial epithelial cells. Dopamine, released from the pericardial organs, acts as a primary messenger, and cyclic AMP acts as a second messenger most likely promoting phosphorylation of membrane proteins. In contrast to aquatic brachyuran crabs, ion transport in B. latro, an anomuran, is controlled via an inhibitory effect. Terrestrial crabs normally have access to fresh water and must salvage salt from their urine, and a mechanism to down-regulate a normally active uptake system seems more appropriate to their ecology. Whether the control is stimulatory or inhibitory in the various air-breathing crabs may depend on the osmoregulatory abilities of their aquatic ancestors, but in either case has significant implications for the evolution of crustaceans to life on land. Further work must establish whether terrestrial brachyuran crabs are similar to B. latro and whether this crab is unique amongst the anomuran crabs.

Adaptation, Physiological↗
PubMed2000

Emotion recognition in schizophrenia: further investigation of generalized versus specific deficit models.

In this study, the authors examined the nature of emotion perception in schizophrenia. Two samples of people with schizophrenia, one receiving acute care for a recent exacerbation of symptoms and the other receiving extended care, were compared with a nonclinical control group on emotion perception and general perception measures. The nonclinical control group obtained the highest scores on all of the study measures, and the acutely ill group obtained the lowest scores. Furthermore, the acutely ill sample had a specific deficit in emotion perception that remained present after controlling for performance on the general perception tasks. Conversely, the deficits in emotion discrimination in the extended-care sample reflected generalized poor performance. Differences in performance on the emotion identification task between the 2 clinical groups were reduced when controlling for active symptoms.

Adult↗
PubMed2000

Determination of enantiomeric purity of hyoscyamine from scopolia extract using HPLC-CD system without chiral separation.

Enantiomeric ratio of hyoscyamine from Scopolia extract was determined by chiral HPLC-CD analysis. It was found that circular dichroism (CD) detection allowed the analysis of the sample without any special pretreatment whereas UV detection required an ammonia-ether extraction. To obtain a shorter analysis time for the determination, reversed-phase HPLC-CD analysis was applied by using a g-factor calibration curve (EE% vs. CD/UV). The analysis time was shortened from 35 to 18 min. EE% values obtained were consistent with those by chiral HPLC analysis.

Atropine↗
PubMed1999

Expression and characterization of elastase inhibitors from the ascarid nematodes Anisakis simplex and Ascaris suum.

Two elastase inhibitors, ASPI-1 and ASPI-2, from the parasitic nematode Anisakis simplex, have been isolated and characterized. Because these inhibitors are similar in size (60 amino acids in length) and primary sequence (52 and 47% identical) to the Ascaris suum chymotrypsin/elastase inhibitor-1 (AsC/E-1), we suggest that these Anisakis elastase inhibitors belong to the same unique class of canonical inhibitors formed by the family of Ascaris inhibitors (Huang K, Strynadka NCJ, Bernard VD, Peanasky RJ, James MG. Structure 1994;2:679-689). To compare ASPI-1 with AsC/E-1, we expressed both inhibitors in Pichia pastoris and found that: (1) the association constant of rASPI-1 with porcine pancreatic elastase (PPE) is similar to native inhibitor (Ka = 4.5 x 10(9) and 6.4 x 10(9) M(-1), respectively); (2) rASPI-1 is a potent inhibitor of PPE and human leukocyte elastase (Ka = 1.6 x 10(9) M(-1)); and (3) it is only a very weak inhibitor of chymotrypsin (CHYM) (Ka = 1.2 x 10(6) M(-1)). In contrast to the Anisakis inhibitor, however, rAsC/E inhibitor-1 is a very strong inhibitor of both PPE (Ka = 3.5 x 10(10) M(-1)) and CHYM (Ka = 3.6 x 10(12) M(-1)). We also found that the determined reactive sites (P1-P'1) of rASPI-1 and rAsC/E-1, as recognized by PPE, are Ala 28-Met 29 and Leu 31-Met 32, respectively. These P1-P'1 residues of AsC/E-1 constitute the same reactive site as that also recognized by CHYM (Peanasky RJ, Bentz Y, Homandberg GA, Minor ST, Babin DR. Arch Biochem Biophys 1994;232:135-142). The difference in specificities of ASPI-1 and AsC/E-1 toward their cognate serine proteases may be attributed to the P1 and P'3 residues in the inhibitors. Elastase, which recognizes both alanine and leucine, canaccommodate both ascarid inhibitors, whereas chymotrypsin, which prefers bulky, hydrophobic residues, only recognizes the Ascaris C/E inhibitor-1.

Amino Acid Sequence↗
PubMed1999

Case-control isotonic regression for investigation of elevation in risk around a point source.

Stone's isotonic regression method for analysing count data to estimate disease risk in relation to a point source of environmental pollution is now routinely used. This paper develops the corresponding procedure for case-control data consisting of the locations of individual cases with controls with associated covariate information. In this setting, the generalized likelihood ratio statistic to test the null hypothesis of constant risk against the alternative that risk is a monotone non-increasing function of distance from the point source is intractable. An approximate Monte Carlo test is described, extending an exact test proposed by Bithell for the situation in which there are no covariates. Interval estimates of risk as a function of distance from the point source are constructed by simulation of the sampling distribution of the isotonic regression estimator. The methodology is illustrated by two applications: one to the relative risk of larynx cancers and lung cancers near a now-disused industrial incinerator; the other to the risk of asthma in children in relation to distance of residence from the nearest main road.

Adolescent↗
PubMed1999

The association between tender points, psychological distress, and adverse childhood experiences: a community-based study.

OBJECTIVE: To examine the hypothesis that characteristics of somatization and illness behavior, and their childhood antecedents, are associated with the presence of multiple tender points. METHODS: Two hundred eighty-nine subjects who had demonstrated psychological distress (General Health Questionnaire score > or =2) had a tender point examination and in-depth psychological evaluation. In addition, subjects were interviewed about a number of adverse childhood experiences. The 99 subjects with 5 or more tender points were compared with the remaining 190 subjects. RESULTS: A high tender point count (> or =5) was associated with low levels of self-care (odds ratio [OR] 2.4, 95% confidence interval [95% CI] 1.1-5.0), reports of a greater number of somatic symptoms (OR 2.2, 95% CI 1.0-4.9), high levels of fatigue (OR 3.3, 95% CI 1.7-6.3), and a pattern of illness behavior characterized by increased medical care usage (OR 4.2, 95% CI 2.1-8.4). Those with high tender point counts were substantially more likely to report adverse childhood experiences, including loss of parents (OR 2.1, 95% CI 1.1-3.9) and abuse (OR 6.9, 95% CI 2.0-24.6). These results were not explained by the presence of chronic pain. CONCLUSION: These data add further weight to the hypothesis that tender points, as part of the fibromyalgia syndrome, are strongly associated with specific components of psychological distress as well as characteristics of somatization and its antecedents. It is possible that these features contribute to the development of the syndrome of fibromyalgia.

Adolescent↗