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Biomedical subjects

A Wahlström

Publications and source records attributed to A Wahlström.

At least 19 recordsLinked to original sources
PubMed2003

A field survey of chemicals and biological products used in shrimp farming.

This study documented the use of chemicals and biological products in marine and brackish water shrimp farming in Thailand, the world's top producer of farmed shrimp. Interviews were conducted with 76 shrimp farmers in three major shrimp producing regions, the eastern Gulf coast, the southern Gulf coast and the Andaman coast area. Farmers in the study used on average 13 different chemicals and biological products. The most commonly used products were soil and water treatment products, pesticides and disinfectants. Farmers in the southern Gulf coast area used a larger number of products than farmers in the other two areas. In the study, the use of more than 290 different chemicals and biological products was documented. Many of the pesticides, disinfectants and antibiotics used by the farmers could have negative effects on the cultured shrimps, cause a risk for food safety, occupational health, and/or have negative effects on adjacent ecosystems. Manufacturers and retailers of the products often neglected to provide farmers with necessary information regarding active ingredient and relevant instructions for safe and efficient use.

Animals↗
PubMed2001

Plumage condition and health of aviary-kept hens fed mash or crumbled pellets.

In the present experiment, we evaluated the effects on plumage condition and health of feeding a mash or a crumbled diet to two hybrids of laying hens in an aviary system. The two diets had the same composition and calculated nutrient content. A total of 3,204 birds was studied from 20 to 80 wk of age. Two hybrids, Lohmann Selected Leghorn and SLU-1329 (two line crosses of Leghorn and Rhode Island Red), were housed in six pens each of an aviary system with groups of 269 and 265 birds, respectively. There were three replicates per treatment (diet x hybrid). Diet generally had little effect on plumage condition, health, and tonic immobility. However, birds fed the crumbled diet had significantly fewer problems with bumble foot than those fed the mash diet. Hybrids reacted differently in most traits studied; SLU-1329 had better health scores but more problems with cannibalism and salpingitis than Lohmann Selected Leghorns, whereas the reverse was found in the proportion of cases with coccidiosis. The hybrid differences found underline the importance of genotype.

Animal Feed↗
PubMed1999

Production and egg quality as influenced by mash or crumbled diets fed to laying hens in an aviary system.

Effects of feeding a crumbled diet compared with a mash diet on laying performance and egg quality of two hybrids of laying hens, a total of 3,204 birds, kept in an aviary system from 20 to 80 wk of age, were investigated. The two diets had the same composition and calculated nutrient content. Two hybrids, Lohmann Selected Leghorn (LSL) and SLU-1329 (a two-line cross of Leghorn x Rhode Island Red), were housed in six pens each of an aviary system with groups of 269 and 265 birds, respectively. There was a total of three replicates per treatment (diet x hybrid). Birds fed the mash diet compared with those fed the crumbled diet had a significantly higher proportion of misplaced eggs, inferior feed conversion ratio (FCR), and higher energy consumption per kilogram egg mass produced (collectable misplaced eggs included). The latter birds had higher body and egg weight, suggesting a higher nutritive value for the crumbled diet. Higher egg mass production and a more intensive yolk color were also found for the birds fed the crumbled diet compared with the mash diet. Hybrid affected production and egg quality traits the most. The LSL also showed significantly higher excreta DM compared with SLU-1329. Interactions between diets and hybrids were found regarding the proportion of misplaced eggs, dirty eggs, egg weight, and FCR. Some of the interactions may indicate other genetic and nutritional factors affecting bird performance in aviary systems more than is normally seen in cages.

Animal Feed↗
PubMed1994

Tricyclic antidepressants inhibit opioid receptor binding in human brain and hepatic morphine glucuronidation.

The opioid receptor binding in the human thalamic area was studied with U-69593 and naloxone as ligands for the kappa and mu receptors, respectively. The binding was inhibited by various tricyclic antidepressants including amitriptyline, nortriptyline, clomipramine and fluoxetine. The antidepressants tested had a slight selectivity for the kappa receptor type. The IC50-values for all tricyclic antidepressants tested were in the 10(-6) M concentration range. Morphine and tricyclic antidepressants are substrates of a liver microsomal uridine diphosphate glucuronyl transferase (UDPGT). The interaction of the tricyclic antidepressants with morphine glucuronidation was investigated in human liver microsomal preparations. All drugs inhibited the morphine UDPGT. In Dixon plots inhibition of the formation of morphine-3-glucuronide and morphine-6-glucuronide was non-competitive for nortriptyline, and competitive or mixed for amitriptyline and clomipramine. Lubrol PX activated the morphine-UDPGT four to five times. The degree of activation of the enzyme(s) was unaltered in presence of the inhibiting drugs. The inhibition was also observed at a tricyclic antidepressant/morphine concentration ratio close to that achieved in plasma from patients treated with these drugs.

Antidepressive Agents, Tricyclic↗
PubMed1988

Detection of N-terminally extended substance P but not of substance P in human cerebrospinal fluid: quantitation with HPLC-radioimmunoassay.

A reversed-phase HPLC system was used to concentrate and separate components of substance P-like immunoreactivity (SP-LI) from human CSF. When CSF was injected and fractions collected, no SP-LI could be detected by radioimmunoassay (RIA) at the retention time of SP or SP-sulfoxide. Instead, SP-LI was detected in later eluting fractions. This SP-LI reacted with two different antisera raised against the C-terminal part of SP, but not with an antiserum against the N-terminal part. A compound with similar properties was also found to be present in neutral extracts of rat dorsal spinal cord. When the late-eluting compound from human CSF was treated with trypsin and rechromatographed on HPLC, an immunoreactive component eluting at the position of SP could be detected with both the C- and N-terminally directed SP antisera. These results suggest that an N-terminally extended form of SP is present in human CSF. Trypsinization also gave two other compounds with affinity for the N- but not the C-terminally directed antisera. This may indicate that N-terminal fragments of SP extended at the N-terminus or SP molecules extended at both the N- and the C-terminus (i.e., preprotachykinins) also are present in human CSF. In 32 CSF samples from depressed patients, SP-LI was determined with a C-terminally directed antiserum with and without prior HPLC separation. SP itself could not be detected, but the late-eluting form of SP-LI could be quantitated in all samples by combined HPLC-RIA. In most samples, there was a relatively good agreement between the SP-LI levels measured with and without HPLC.

Antibody Specificity↗
PubMed1988

Human liver morphine UDP-glucuronyl transferase enantioselectivity and inhibition by opioid congeners and oxazepam.

1. Morphine uridine diphosphate glucuronyl transferase (UDP-GT) was studied in human liver microsomes. The (-)- and (+)-morphine enantiomers were used as substrates and inhibitors, such as oxazepam and various opioid congeners were employed to characterize the different glucuronidation pathways. The kinetics of the oxazepam inhibition were studied in the rat liver. 2. The overall glucuronidation of (+)-morphine was higher than that of (-)-morphine. The morphine congeners tested, potently inhibited the formation of (-)-morphine-3-glucuronide ((-)-M3G), except for normorphine and codeine. The formation of (+)-morphine-6-glucuronide [+)-M6G) was potently inhibited by only dextromethorphan and (+)-naloxone. All drugs except normorphine inhibited the formation of (+)-M3G by 18-50%. 3. The metabolism of (-)-morphine to (-)-M3G was more sensitive to oxazepam inhibition than the formation of (+)-M3G from (+)-morphine in the rat liver. 4. The glucuronidation of natural morphine is subject to in vitro interaction with oxazepam and several opiate drugs. Our study supports the theory of more than one type of UDP-GT being involved in morphine glucuronidation.

Animals↗
PubMed1986

Morphine metabolism in mouse brain.

Morphine UDP-glucuronyltransferase activity was demonstrated in the brain of mice from recombinant inbred strains of the BXD series. The formation rate of morphine-3-glucuronide was about 4 fold higher in the progenitor DBA as compared to the C57BL strain.

Animals↗
PubMed1983

Characterization of electrophoretically separable endorphins in human CSF.

Opioid peptides have been purified from large pooled samples of human cerebrospinal fluid. The purification steps involved chromatography on Sephadex G-10 and electrophoresis in agarose suspension. The purified material was further characterized by HPLC and radioimmunoassay. All procedures were guided by a specific radioreceptor assay. The Sephadex G10 fractionation yielded receptor activity in two discrete fractions, Fraction I (FI) and Fraction II (FII). A second Sephadex run of FII gave a partial resolution of two components, one of which was larger (FIIA). Electrophoresis resolved these fractions into several components, most of which showed a more basic behaviour than the enkephalins. Thus, FI separated into at least 4 components and FIIB into two components while FIIA remained a single peak. These components appeared to migrate as distinct peaks and some of them also chromatographed on a HPLC-column as single components. Considering their behaviour in electrophoresis and on HPLC, two components are suggested to represent known endorphin structures. The predominant FII component (FIIA) was thus indistinguishable from Met-enkephalin-Lys6 in all chromatographic systems and one of the most basic FI components showed close similarity with dynorphin. Each of these components occurs at a higher concentration than Met- or Leu-enkephalin, dynorphin or beta-endorphin.

Chromatography, High Pressure Liquid↗
PubMed1982

Endorphin levels in human cerebrospinal fluid during alcohol intoxication and withdrawal.

Levels of endorphins were determined in CSF from alcoholics while intoxicated or after 1 day, 1 week, and 3 weeks of abstinence, respectively, and from healthy volunteers. The level of endorphins was determined by a radioreceptor assay and two fractions were analyzed. With fraction 1, there were no significant differences between the groups, but the level was negatively correlated with the blood-alcohol level. The mean level of endorphin fraction 2 during the early withdrawal phase was significantly lower than those of the other groups. With respect to clinical conditions and monoamine metabolites, fraction 2 in early withdrawal correlated significantly to duration of abuse and age. During late withdrawal, fraction 1 level correlated to depressive symptoms and, after 3 weeks of abstinence, fraction 2 correlated to MOPEG levels. This study suggests that endorphin systems are affected during alcohol intoxication and withdrawal in alcoholics.

Adult↗
PubMed1982

Circannual variation in concentrations of endorphins in cerebrospinal fluid.

In a series of 90 patients with chronic pain syndromes of psychogenic and organic etiology, the concentrations of fraction I endorphins in cerebrospinal fluid were investigated. A significant circannual variation in the concentrations of endorphins was found, with the highest concentrations in January-February and the lowest concentrations in July-August. There was no corresponding seasonal variation with regard to age, sex, bodylength, possible etiology of the pain syndrome self-rated pain levels, or experimental pain measures. Circannual difference in the intensity of symptoms in chronic pain syndromes and in affective disorders have been described in the literature. The present results suggest an association between these observations, giving further support for functional importance of endorphins in chronic pain.

Adult↗
PubMed1982

Endorphin levels in opioid-dependent human subjects: a longitudinal study.

Endorphin levels were measured in 51 cerebrospinal fluid samples from 27 opioid-dependent or postdependent subjects. Radioreceptor assay showed the endorphin levels to be higher than those found in normal subjects. These high levels were found even while subjects were on methadone maintenance. The duration of opioid dependence was positively correlated with fraction I values. Both fractions tended to be lower during early withdrawal than late withdrawal. In naltrexone-maintained patients, radioreceptor assay showed FII to be greatly elevated, but electrophoresis and HPLC indicated that the elevations were not due to a peptide. Thus, the possibility of unextracted naltrexone metabolites remains at least a partial explanation for this apparent FII elevation.

Adult↗
PubMed1981

CSF-endorphins in heroin addicts during methadone maintenance and during withdrawal.

Seventeen opiate-dependent subjects accepted for methadone maintenance treatment were housed in a closed metabolic ward. They stayed drug-free for 3 weeks before methadone treatment was started. One sample of cerebrospinal fluid was taken immediately before the first methadone dose and another sample was taken after the patient had received methadone daily for 3 weeks. Fraction I and II endorphin levels were frequently pathological on both occasions, either elevated or reduced when compared with 19 healthy volunteers. Subjects with pathological pre-treatment levels of both fractions seemed to respond better to the methadone treatment that those with at least one pre-treatment value within the normal range.

Adult↗
PubMed1981

Hemodialysis in schizophrenia: psychiatric aspects of treatment failure in a pilot study.

In order to examine the reported curative effects of hemodialysis in patients with chronic schizophrenia a pilot study approved by the Committee of Ethics at the University of Lund was initiated in September 1977. 13 patients, 10 men and 3 women, 21--44 years old, were treated. All but one were diagnosed as chronic schizophrenia. The duration of illness was 4--20 years. All the patients functioned defectively psychosocially, and conventional therapy had failed. Our goal was to give at least one dialysis treatment a week during 13 weeks. 10 patients completed the treatment series. The patients were scored according to the Brief Psychiatric Rating Scale and the Rockland and Pollin scale before, during and after the treatment. Conventional therapy was given throughout. Analysis of hemofiltrates for endorphins did not reveal any abnormal levels. 1 patient reported a distinct and hitherto lasting improvement. Marginal and temporary improvements were noted in 3 patients. Therefore placebo effects or spontaneous remission seemed probable. The ratings showed no significant changes in any patient during the treatment period. All patients including those who showed improvement remained seriously incapacitated by their psychiatric illness. Different psychiatric aspects of our failure to reproduce the American findings including cultural discrepancies in diagnostic criteria are discussed.

Adult↗