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Biomedical subjects

J Rees

Publications and source records attributed to J Rees.

At least 145 records · Page 8Linked to original sources
PubMed1976

Quantitative determination of salbutamol in plasma, as either its trimethylsilyl or t-butyldimethylsilyl ether, using a stable isotope multiple ion recording technique.

Two methods are described for the determination of salbutamol in human plasma. The drug is extracted from the plasma as a salbutamol tetraphenylboron ion pair and determined by gas chromatography mass spectrometry. Trideuterio-salbutamol is used as an internal standard. In the first method an extensive purification procedure is used to separate salbutamol from plasma cholesterol which interferes in the assay. Salbutamol is then determined as its TMS-ether using a multiple ion recording technique to measure the intensity of the fragment ion m/e 369 and the ion m/e 372 from the TMS ether of trideuterio-salbutamol. The second method is based on the ion pair extraction of salbutamol into heptan-3-one and its determination by gas chromatography mass spectrometry as the t-butyldimethylsilyl ether. The base peak in the mass spectrum of the t-butyldimethylsilyl-salbutamol is an ion of m/e 495, which is of sufficiently high mass to distinguish it from any of the ions which arise from t butyldimethylsilyl-cholesterol. Six replicate analyses of plasma samples containing 1 ng salbutamol ml-1 were carried out using both methods. When the first method was used the mean value obtained was 1.3 ng ml-1 and the coefficient of variation was 17.7%. When the second method was used the mean value obtained was 0.95 ng ml-1 and the coefficient of variation was 10%. The second method is more rapid and therefore preferable for use in clinical pharmacological studies. This method has been used to determine the plasma salbutamol concentrations at varying times after either a 4 mg oral or a 200 mug intravenous dose of salbutamol to man.

Albuterol↗
PubMedDate not supplied

Lead in umbilical blood, indoor air, tap water, and gasoline in Boston.

A strong statistical correlation was found among the monthly averages of lead concentrations in umbilical cord blood (about 500 births/month), indoor air (12 sites/month), and gasoline lead sales between March, 1980 and April, 1981 in Boston. Tap water lead (24/month) variations did not correlate with blood lead in this population.

Air Pollutants↗
PubMedDate not supplied

Gadolinium chloride toxicity in the rat.

Groups of 10 male and 10 female Sprague-Dawley rats were given a single intravenous injection of gadolinium chloride solution at dosages of 0 (saline vehicle), 0.07, 0.14, and 0.35 mmol/kg. Apart from 1 top-dose female, which died during dosing, 5 rats/sex/ group were necropsied 48 hr postdose, and the remaining 5 rats/sex/group were necropsied 14 days postdose. Macroscopic, hematological, and clinical chemistry analyses were undertaken on all animals that were necropsied. Histopathological examination was undertaken on all organs from high-dose and control animals necropsied 48 hr postdose and on tissues that showed treatment-related changes from all other rats necropsied either 48 hr or 14 days postdose. Major lesions related to gadolinium chloride administration consisted of mineral deposition in capillary beds (particularly lung and kidney), phagocytosis of mineral by the mononuclear phagocytic system, hepatocellular and splenic necrosis followed by dystrophic mineralization, mineralization of the fundic glandular mucosa in the absence of necrosis followed by mucous cell hyperplasia, decreased platelet numbers and increased prothrombin time, and activated partial thromboplastin time. Electron microscopy and x-ray microanalysis of the spleen and liver revealed electron-dense deposits in splenic macrophages, Kupffer cells, and hepatocytes composed of gadolinium, calcium, and phosphate.

Adrenal Glands↗
PubMedDate not supplied

Time course of stomach mineralization, plasma, and urinary changes after a single intravenous administration of gadolinium(III) chloride in the male rat.

In a previous experiment it was reported that the intravenous administration of gadolinium chloride (GdCl3) to rats results in a discrete band of interstitial mineralization in the fundic glandular mucosa of the stomach. To investigate the time course for the development of this lesion and its relationship to plasma calcium and phosphate concentrations, 2 experiments were carried out in male Sprague-Dawley rats given a single intravenous dose of 0.07 mmol/kg GdCl3. Plasma calcium and phosphate concentrations approximately doubled between 30 min and 12 hr postdose but had regressed back to near normal values by 24 hr. However, there were no observable clinical signs in treated animals. Histologically, there was progressive mineralization of the lamina propria of the neck region of the fundic glands from 6 hr postdose, forming a distinctive mineral band by 12 hr postdose. At 7 and 14 days postdose the mineral deposits were accompanied by mucous cell hyperplasia, interstitial fibrosis, and a very sparse infiltration of inflammatory cells. By 56 days postdose only occasional mineral deposits remained. Transmission electron microscopy showed mineral first nucleated on collagen in the interstitium, but there was no evidence of cell necrosis. X-ray microanalysis showed that the interstitial mineral was composed of calcium and phosphate in the form of hydroxyapatite; gadolinium (Gd) was only very rarely identified. These findings are consistent with metastatic mineralization. The source, cause, and the exact nature of the excess plasma calcium and phosphate are unknown, and the possible significance of this effect for clinical use of Gd-containing chelates in nuclear magnetic resonance imaging requires further investigation.

Animals↗
PubMedDate not supplied

Psychological effects of isolation nursing (1): Mood disturbance.

AIM: This study is part one of a research project aiming to investigate the relationship between mood disturbance and a range of quality of care factors among patients nursed in source isolation in acute and rehabilitation care settings, and to assess the accuracy of clinical staff's recognition of such disturbance. METHOD: A small audit-style evaluation of aspects of the overall clinical care of patients nursed in isolation. The findings reported here are the preliminary results of a larger study (Rees et al 2000). RESULTS: More than half of the sample was suffering from mood disturbance, and depression appeared to be under recognised by staff. There was a trend for higher anxiety scores to be more strongly associated with antidepressant prescription. CONCLUSION: Mood disturbance is a significant consequence of source isolation in patients, however healthcare staff have poorer recognition and treatment of depression than anxiety. Nurse education should include identification of disturbed mood, discrimination between depressed and anxious mood, and development of treatment protocols.

Adult↗
PubMedDate not supplied

Psychological effects of source isolation nursing (2): Patient satisfaction.

AIM: This study is part two of a research project (Davies and Rees 2000) aiming to investigate the relationship between mood, patient satisfaction and a range of quality of care factors among patients nursed in source isolation in acute and rehabilitation settings. METHOD: A small audit-style evaluation of aspects of the overall clinical care of patients nursed in isolation. Twenty one patients being nursed in source isolation were interviewed to assess factors relating to delivery of care. RESULTS: The authors noted frequent mood disturbances among isolated patients, although most were generally satisfied with their care and surroundings. Factors associated with patient satisfaction included being kept up to date with progress and procedures, having a comfortable environment and good communication between staff and patients. CONCLUSION: The authors suggest that staff training should include consistent use of verbal and written information. The patients should be allowed access to telephone and television, and their surroundings should be kept clean.

Adult↗
PubMedDate not supplied

Post-genome integrative biology: so that's what they call clinical science.

Medical science is increasingly dominated by slogans, a characteristic reflecting its growing bureaucratic and corporate structure. Chief amongst these slogans is the idea that genomics will transform the public health. I believe this view is mistaken. Using studies of the genetics of skin cancer and the genetics of skin pigmentation, I describe how recent discoveries have contributed to our understanding of these topics and of human evolution. I contrast these discoveries with insights gained from other approaches, particularly those based on clinical studies. The 'IKEA model of medical advance'--you just do the basic science in the laboratory and self-assemble in the clinic--is not only damaging to clinical advance, but reflects a widespread ignorance about the nature of disease and how clinical discovery arises. We need to think more about disease and less about genes; more in the clinic and less in the laboratory.

Animals↗