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Biomedical subjects

S Svensson

Publications and source records attributed to S Svensson.

At least 55 records · Page 3Linked to original sources

Renal effects of alpha-ketoglutarate early after coronary operations.

BACKGROUND: Alpha-ketoglutarate (alpha-KG) is a Krebs cycle intermediate and the carbon skeleton of glutamate. Alpha-ketoglutarate has provoked interest in heart surgery because of its proposed critical role in myocardial metabolism. This study investigates the role of alpha-KG in renal function after cardiac surgical procedures. METHODS: Twenty-two patients with normal preoperative renal function were included in a prospective, randomized, and controlled study. Eleven patients received intravenous infusion of 30 g alpha-KG/hour after the operation. Measurements were performed before operation, immediately after operation, and after 30 minutes of alpha-KG infusion. RESULTS: Renal blood flow was higher during alpha-KG infusion, 297% +/- 97% (of preoperative value), than in controls, 125% +/- 20% (p < 0.05). Filtration fraction was lower (12.3% +/- 0.05% versus 17.2% +/- 1.1%, p < 0.01), which prevented a significant difference in glomerular filtration rate. The renal arteriovenous differences of lactate, glutamate, glutamine, and glycine changed toward a net release during alpha-KG infusion. CONCLUSIONS: Infusion of alpha-KG enhances renal blood flow early after coronary surgical procedures in patients with normal renal function. The mechanism is unclear, but could be associated with primarily metabolic effects, and may potentially convey a beneficial effect for renal function.

Adult↗

Insulin and amino acid infusion after cardiac operations: effects on systemic and renal perfusion.

OBJECTIVE: The purpose of this study was to answer two questions: (1) Does a mixed amino acid infusion enhance systemic and renal perfusion in the early postoperative period after heart operations? (2) Does the addition of insulin (glucose-insulin-potassium solution) provide additional effects to those of an amino acid infusion? METHODS: Thirty-three male patients undergoing coronary artery bypass grafting (mean age 65.9 +/- 1.2 years) were included in a prospective, controlled, randomized study. Eleven patients (AA group) received infusion of mixed amino acids (11.4 gm), 11 patients (AA + GIK group) received infusion of mixed amino acids (11.4 gm) and insulin solution (225 IU insulin, glucose with glucose clamp technique, and potassium), and 11 patients served as control subjects. RESULTS: Amino acid infusion alone had no effect on systemic vascular resistance or cardiac index but increased renal blood flow 51% +/- 11% (from 114 +/- 13 to 172 +/- 24 ml.min-1.m-2 in one kidney, p < 0.05 vs the control group). Insulin solution in addition to amino acid infusion reduced systemic vascular resistance 24% +/- 3% (from 1280 +/- 85 to 960 +/- 57 dyn.sec.cm-5, p < 0.05 vs the control and AA groups) and increased cardiac index 13% +/- 3% (from 2.3 +/- 0.2 to 2.6 +/- 0.2 L.min-1.m-2, p < 0.05 vs the control and AA groups). Insulin had no significant additive effect on renal blood flow. CONCLUSIONS: Our data imply that (1) infusion of mixed amino acids enhances renal blood flow after cardiac operations but has no effect on systemic perfusion and (2) the addition of insulin solution improves systemic perfusion. The combined treatment may potentially reduce the risk of renal hypoperfusion injury in the postoperative period after coronary artery bypass grafting.

Adult↗

Hypertensive patients' knowledge of high blood pressure.

OBJECTIVE: To investigate hypertensive patients' understanding of the circulatory system, in particular high blood pressure. DESIGN: Semi-structured audio-taped interviews of patients immediately after a regular follow-up appointment with their physician. SETTING: A primary health care centre and a specialist clinic (hypertension unit) in southern Sweden. PATIENTS: 33 hypertensive patients, consecutively selected. MAIN OUTCOME MEASURE: Focus was set on the exploration of patients' understanding/knowledge. RESULTS: In spite of a long history of hypertensive care, on average ten years, patients had a less than satisfactory understanding of their condition. Most patients knew their blood pressure values, but very few were able to give an account of what high blood pressure implies in functional terms. Knowledge of high blood pressure seems mainly to be derived from sources other than the health care system, in particular from the mass media. Knowledge of the risks associated with hypertension was quite good, as was the insight into how these risks could be managed. CONCLUSION: An assessment of patient knowledge of high blood pressure ought to be a starting point for educational strategies that aim to deepen patients' understanding of their state of health.

Adult↗

Alcohol dehydrogenase in human tissues: localisation of transcripts coding for five classes of the enzyme.

Tissue distribution of the five identified classes of human alcohol dehydrogenase was studied by assessment of mRNA levels in 23 adult and four fetal tissues. Alcohol dehydrogenase of class I was found in most tissues, brain and placenta excluded, but expression levels among tissues differed widely. The distribution pattern of class III transcripts was consistent with those of housekeeping enzymes while, in contrast, class IV transcripts were found only in stomach. Transcripts of multiple length were detected for most classes and were due to different gene products arising through the use of different poly-A signals or transcription from different gene loci. Both class II and class V showed a pattern of liver-enriched expression. However, low mRNA levels were detected also in stomach, pancreas and small intestine for class II, and in fetal kidney and small intestine for class V. Significantly higher levels of class V transcripts were present in fetal liver when compared with levels in adult liver, which suggests that human class V is a predominantly fetal alcohol dehydrogenase.

Alcohol Dehydrogenase↗

Aldehyde dismutase activity of human liver alcohol dehydrogenase.

Human alcohol dehydrogenases of class I and class II but not class III catalyse NAD+-dependent aldehyde oxidation in addition to the NADH-dependent aldehyde reduction. The two reactions are coupled, i.e. the enzymes display dismutase activity. Dismutase activity of recombinantly expressed human class I isozymes beta1beta1 and gamma2gamma2, class II and class III alcohol dehydrogenases was assayed with butanal as substrate by gas chromatographic-mass spectrometric quantitations of butanol and butyric acid. The class I gamma2gamma2 isozyme showed a pronounced dismutase activity with a high kcat, 1300 min(-1), and a moderate Km, 1.2 mM. The class I beta1beta1 isozyme and the class II alcohol dehydrogenase showed moderate catalytic efficiencies for dismutase activity with lower kcat values, 60-75 min(-1). 4-Methylpyrazole, a potent class I ADH inhibitor, inhibited the class I dismutation completely, but cyanamide, an inhibitor of mitochondrial aldehyde dehydrogenase, did not affect the dismutation. The dismutase reaction might be important for metabolism of aldehydes during inhibition or lack of mitochondrial aldehyde dehydrogenase activity.

Alcohol Dehydrogenase↗

Progression of canine mammary tumours as reflected by DNA ploidy in primary tumours and their metastases.

Thirty dogs with metastasizing mammary tumours (carcinomas, n = 22; sarcomas, n = 8) were necropsied. Flow cytometric DNA analysis was carried out on frozen primary tumours and on selected metastases from the dogs. Ductular carcinomas (n = 13) had a varying growth pattern, in terms of histology, in both the primary tumours and metastases and between different metastases. The different types of DNA ploidy, including hypodiploidy, in the primary ductular carcinomas were also seen in the tumour metastases. Dogs with primary anaplastic carcinomas (n = 7) had multiple metastases, which were in most cases near-diploid or hyperdiploid. Two dogs had spindle-cell carcinomas, which were hypodiploid in both the primary tumour and the metastases. The DNA ploidy in the metastases was retained in 16 of the 22 dogs with primary carcinomas. Fibrosarcomas (n = 5) showed different types of DNA ploidy. In two of the three dogs with diploid or near-diploid osteosarcomas, the DNA ploidy was retained in the metastases. There was a statistically significant association between mammary tumours and metastases (P = 0.0001) in terms of both histological diagnosis and DNA ploidy. The association was retained when the carcinomas were tested separately (P = 0.0001); in the sarcomas it was retained weakly in terms of histology (P = 0.0183) but not DNA ploidy (P = 0.6659). The retention of the DNA ploidy in most carcinoma metastases indicated that selection of DNA ploidy had taken place prior to metastasis. The differences in patterns of DNA ploidy between ductular and anaplastic carcinomas may reflect different pathogenesis in these types of canine mammary tumour.

Animals↗