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Biomedical subjects

G Lindstedt

Publications and source records attributed to G Lindstedt.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Bone marrow depression after azathioprine. New discoveries on an old drug].

Azathioprine, a cytostatic and immunosuppressive drug in use for some 30 years, can give rise to life-threatening neutropenia and thrombocytopenia. This may be caused by unexpectedly high concentrations of cytotoxic metabolites due to abnormally slow inactivation of 6-mercaptopurine (6-MP) by thiopurine S-methyltransferase (TPMT) and/or xanthine oxidase. Low TPMT activity may be due to genetic polymorphism or interaction with drugs such as salicylic acid derivatives, while xanthine oxidase may be inhibited by allopurinol. High TPMT activity, on the other hand, may hamper cytostatic treatment. Safer and more effective treatment with azathioprine and its metabolite 6-MP becomes possible with new laboratory methods for pharmacotherapy monitoring.

Aged↗
PubMed2000

[Don't miss prolactinoma! On the importance of measuring prolactin and how it is done].

Prolactinoma is the most common functional pituitary tumor. Since appropriate treatment is often pharmacological rather than surgical, all patients with a tumor within or close to the sella turcica should be evaluated for prolactinoma before being sent for neurosurgery. Preanalytical factors affecting serum prolactin concentration should be taken into account when planning blood sampling. Diagnostic laboratories should aim for the use of common international calibrators and a common unitage for expressing concentrations. Assays should be carried out in such a way that the risk of falsely high or low values is minimized. Any patient with high values due to an immunometric method should be evaluated for the possible presence of endogenous antibodies against prolactin ("macroprolactinemia").

Adult↗
PubMed2000

Relations between Helicobacter pylori, thyroid disease and cardiovascular risk factors in a 56-65-year-old population.

OBJECTIVE: To estimate the prevalence of and relation between Helicobacter pylori (HP) and thyroid disease in a 56-65-year-old population with cardiovascular risk factors. DESIGN: Cross-sectional study including every second individual in the age group. SETTING: The primary health care district of Mölnlycke, with about 14,000 inhabitants. PATIENTS: 170 men and 217 women aged between 56 and 65 years. MAIN OUTCOME MEASURES: Anthropometric (body mass index (BMI), waist/hip ratio (WHR)) and blood pressure measurements, biochemical analyses, including s-TSH, s-FT4 and HP serology. RESULTS: There was a high prevalence of metabolic risk factors in this pre-retirement group of individuals. The prevalence of HP was 42% in both men and women. Only a significant correlation between HP and WHR was seen in men. CONCLUSIONS: No reason could be found for including analysis of HP and thyroid tests in screening programmes for cardiovascular risk factors in men and women.

Age Distribution↗
PubMed2000

Plasma erythropoietin concentrations in polycythaemia vera with special reference to myelosuppressive therapy.

In 80 patients with polycythaemia vera (PV) a total of 108 venous blood samples were obtained and analysed for EDTA-plasma erythropoietin (EPO) concentration. At the time of study 21 of the PV patients were newly diagnosed and had prior to blood sampling neither received phlebotomy treatment nor therapy with myelosuppressive agents; these subjects had a mean plasma EPO concentration of 0.5+/-0.9 IU/L. Thirty-seven patients treated with phlebotomy only had a mean plasma EPO concentration of 2.5+/-2.9 IU/L. The mean plasma EPO concentrations for 26 patients treated with hydroxyurea, 13 patients treated with radiophosphorous and 11 patients given a combination of myelosuppressive agents were 8.9+/-8.0, 10.9+/-12.6 and 7.2+/-7.4 IU/L, respectively. Untreated patients and patients on phlebotomy only had significantly lower values for plasma EPO than patients on therapy with myelosuppressive drugs. This finding persisted also after a correction for differences in haemoglobin levels had been introduced. Thereby, the present results would suggest a difference in the EPO feedback system in untreated and phlebotomised PV patients compared to PV patients treated with myelosuppressive agents.

Adult↗
PubMed2000

Plasma erythropoietin in essential thrombocythaemia: at diagnosis and in response to myelosuppressive treatment.

Sixty-five patients with essential thrombocythaemia (ET) on different treatment regimens were studied with regard to EDTA-plasma erythropoietin (EPO) concentrations. In accordance with other studies we found that close to 50% of the untreated ET patients had subnormal (<3.7 IU/L) plasma EPO. The mean plasma EPO concentration for untreated ET patients was significantly lower compared to patients treated with hydroxyurea (HU), radiophosphorous, alpha-interferon or combinations of myelosuppressive agents. This was also true after correction for differences in haemoglobin concentrations had been introduced. An increase in plasma EPO was recorded in all 20 ET patients in whom plasma EPO was registered before and after initiation of myelosuppressive therapy. At the time of diagnosis plasma EPO concentration was available in 31 of the ET patients. In 13 of them the plasma EPO was subnormal whereas the EPO concentrations were > or =3.7 IU/L in the remaining 18 subjects. It was demonstrated that the time to initiation of myelosuppressive treatment was significantly shorter for the former group of patients; they also had more vascular events (11 out of 13) than the group of patients with plasma EPO concentrations > or =3.7 IU/L (9 out of 18). It therefore appears that a subnormal plasma EPO in newly diagnosed ET might be a risk factor for the development of vascular complications.

Adult↗
PubMed2000

Effects of electro-acupuncture on anovulation in women with polycystic ovary syndrome.

BACKGROUND: The present study was designed to evaluate if electro-acupuncture (EA) could affect oligo-/anovulation and related endocrine and neuroendocrine parameters in women with polycystic ovary syndrome (PCOS). METHODS: Twenty-four women (between the ages of 24 and 40 years) with PCOS and oligo-/amenorrhea were included in this non-randomized, longitudinal, prospective study. The study period was defined as the period extending from 3 months before the first EA treatment, to 3 months after the last EA treatment (10-14 treatments), in total 8-9 months. The menstrual and ovulation patterns were confirmed by recording of vaginal bleedings and by daily registrations of the basal body temperature (BBT). Blood samples were collected within a week before the first EA, within a week after the last EA and 3 months after EA. RESULTS: Nine women (38%) experienced a good effect. They displayed a mean of 0.66 ovulations/woman and month in the period during and after the EA period compared to a mean of 0.15 before the EA period (p=0.004). Before EA, women with a good effect had a significantly lower body-mass index (BMI) (p<0.001), waist-to-hip circumference ratio (WHR) (p=0.0058), serum testosterone concentration (p=0.0098), serum testosterone/sex hormone binding globulin (SHBG) ratio (p=0.011) and serum basal insulin concentration (p=0.0054), and a significantly higher concentration of serum SHBG (p=0.040) than did those women with no effect. CONCLUSION: Repeated EA treatments induce regular ovulations in more than one third of the women with PCOS. The group of women with good effect had a less androgenic hormonal profile before treatment and a less pronounced metabolic disturbance compared with the group with no effect. For this selected group EA offers an alternative to pharmacological ovulation induction.

Adult↗
PubMed1999

[Nitrous oxide can cause cobalamin deficiency. Vitamin B12 is a simple and cheap remedy].

Nitrous oxide may cause neurological and haematological signs and symptoms, as a result of its tendency to form complex with cobalt(I) in methylcobalamin, the cofactor for methionine synthase (EC 2.1.1.13), resulting in irreversible oxidation of the cofactor and inactivation of the enzyme protein. Formation of active enzyme requires new protein synthesis, as well as cobalamin supply (vitamin B12). Patients with low or marginal cobalamin depots (commonly found in the elderly) are at risk. The risk may be avoided by giving vitamin B12 to patients with confirmed or suspected cobalamin deficiency in good time before surgery involving nitrous oxide anaesthesia.

Anesthetics, Inhalation↗
PubMed1999

[How reliable is the laboratory? Increased needs of patient-related quality assurance].

Recent developments in medical care and research involve the increased use of immunochemical assays for hormones, tumour markers, vitamins and drugs. External quality assurance programmes using pooled human sera usually fail to detect analytical interference due to substances (e.g. anti-immunoglobulin or anti-ligand antibodies) present in individual serum specimens. The article reports on experience gained during a three-year period when specimens from individual patients attending a thyroid unit were distributed to hospital laboratories in Sweden for analysis. Specimen selection criteria were based on contradictory findings at the initial clinical or laboratory evaluation. The programme has given rise to the formation of a network of the laboratories involved, under the co-ordination of EQUALIS (External quality assurance in laboratory medicine in Sweden).

Antibodies↗