Biomedical subjects

J Kjellberg

Publications and source records attributed to J Kjellberg.

17 recordsLinked to original sources

PubMed2002

The effects of platelet apheresis in total hip replacement surgery on platelet activation.

BACKGROUND: Autologous platelet rich plasma (PRP) harvest with autotransfusion devices has been used for 10 years in cardiac surgery and recently in orthopedics as a blood saving method. The quality of the harvested platelets has not been adequately examined, in part because of methodological difficulties in studying platelet function during surgery. METHODS: Twenty patients undergoing primary total hip replacement (THR) were studied. Ten patients underwent an immediate preoperative platelet apheresis to obtain concentrated platelet rich plasma (c-PRP). The other 10 patients not undergoing apheresis were allocated to a control group. Platelet activation was evaluated as the population expressing P-selectin on the surface of platelets in the c-PRP and in blood samples collected pre-, per- and postoperatively. The method used was flow cytometry. RESULTS AND CONCLUSIONS: A minor population of activated platelets was found to be circulating in the patients' blood, with a highly significant difference between patients (P = 0.005), and with a range of 1-23% in peroperative activation. PRP harvest did not significantly alter platelet activity. The platelet apheresis procedure did not inhibit platelet function in the c-PRP, as judged by a high proportion of platelets that could be activated in ADP stimulation experiments (mean value +/- SD 86% +/- 7.5%).

Adenosine Diphosphate↗

PubMed2001

Quality of life in patients with prostate cancer.

OBJECTIVES: Quality of life (QOL) issues are important for patients with prostate cancer because side effects from treatment are substantial, while the disease itself may be indolent. This article reviews prostate cancer QOL studies. DATA SOURCES: Selected studies published on QOL in prostate cancer using validated patient-assessed tools from the last 5 years. CONCLUSIONS: Prostate cancer treatments are associated with side effects: prostatectomy has more urinary and sexual side effects, while external radiation therapy has more bowel symptoms. Side effects are not highly correlated with overall QOL. IMPLICATIONS FOR NURSING PRACTICE: Patients must be made aware of potential gains in life expectancy as well as side effects of treatments to make informed decisions about treatment.

Clinical Trials as Topic↗

PubMed2000

Preoperative platelet-rich plasmapheresis and hemodilution with an autotransfusion device in total hip replacement surgery.

The effectiveness of both preoperative autologous donation (PAD) and intraoperative autotransfusion (IAT) with an autotransfusion device has recently been questioned. Preoperative apheresis, with separation of concentrated platelet rich-plasma (c-PRP) and erythrocyte concentrate (ERC), represents an aggressive use of the autotransfusion device. Can such a procedure replace PAD in total hip replacement surgery (THR)? Eighty patients undergoing THR were investigated in a prospective and randomized study. Forty patients underwent PAD, and 2 units of ERC + plasma were retrieved within 4 weeks preoperatively. Another 40 patients underwent an immediately preoperative apheresis with a concomitant hemodilution with 4% albumin, retrieving c-PRP (30% of the platelet pool) and 2 units of ERC. Both groups used IAT up to 2 hours postoperatively, with 3% dextran-60 as a plasma substitute according to our standard of care. There were no differences in blood loss, B-hemoglobin or allogeneic transfusions between the groups: 85% of the patients did not receive allogeneic blood. Both apheresis and reinfusion of c-PRP had minor impact on the coagulation parameters. Platelet count increased slightly but significantly (P<0.05) from 154 to 179 x 10(9)/L after the c-PRP at wound closure. Preoperative apheresis with an autotransfusion device, separating platelet-rich plasma and erythrocyte concentrate, is a useful alternative for patients who are unable to utilize the PAD technique for either religious or practical reasons.

Aged↗

PubMed2000

Tranexamic acid reduces blood loss in total hip replacement surgery.

UNLABELLED: Intraoperatively administered, tranexamic acid (TA) does not reduce bleeding in total hip replacement (THR). Therefore, its prophylactic use was attempted in the present study because this has been shown to be more effective in cardiac surgery. We investigated 40 patients undergoing THR in a prospective, randomized, double-blinded study. Twenty patients received TA given in two bolus doses of 10 mg/kg each, the first just before surgical incision and the second 3 h later. In addition, a continuous infusion of TA, 1.0 mg. kg(-1). h(-1) for 10 h, was given after the first bolus dose. The remaining 20 patients formed a control group. Both groups used preoperative autologous blood donation and intraoperative autotransfusion. Intraoperative bleeding was significantly less (P: = 0.001) in the TA group compared with the control group (630 +/- 220 mL vs 850 +/- 260 mL). Postoperative drainage bleeding was correspondingly less (P: = 0.001) (520 +/- 280 vs 920 +/- 410 mL). Up to 10 h postoperatively, plasma D-dimer concentration was halved in the TA group compared with the control group. One patient in each group had an ultrasound-verified late deep vein thrombosis. In conclusion, we found TA, administrated before surgical incision, to be efficient in reducing bleeding during THR. IMPLICATIONS: In a prospective, double-blinded study of 40 patients undergoing total hip replacement, the preoperative administration of tranexamic acid reduced bleeding by 35%, probably by decreasing induced fibrinolysis. Whether tranexamic acid therapy can replace predonation of autologous blood or intraoperative autotransfusion requires further study.

Aged↗

PubMed1989

Laser-induced desorption of proteins.

Laser-induced desorption mass spectrometry has been applied to a number of proteins in the mass range 5000-150,000 u. The beam from an excimer-laser-pumped dye-laser at 266 nm has been focused to a spot of about 50 microns in diameter with irradiances in the 10(7) W/cm2 region. A linear time-of-flight mass spectrometer has been used for mass spectrometric measurements, where positive and negative secondary ions of large proteins have been studied. The effect of different experimental parameters on the protein ion-signal intensities are discussed.

Lasers↗

PubMed1984

Californium-252 plasma desorption time of flight mass spectroscopy of proteins.

Fast heavy ions, i.e. fission fragments from a 252Cf-source, have been used to desorb and ionize peptides and proteins from a sample surface. Masses of the desorbed ions have been determined by the time-of-flight technique. The mass interval of the molecules studied is 1000-14 000 u. Quasi-molecular ions of higher masses than earlier reported have been observed. The results include the detection of quasi-molecular ions of proinsulins, cytochrome-C, ribonuclease and two phospholipases. The general features of mass spectra of proteins using this ionization method are described. Emphasis is put on the discussion of metastable ion decay, neutral components, multiply charged ions, isotopic broadening, and cluster ion formation. Also the precision which can be obtained with a straight time-of-flight mass spectrometer will be discussed. Future applications of the technique are outlined.

Animals↗

PubMed1983

The observation of quasi-molecular ions from a protein neurotoxin (MW 7821) using 127I-plasma desorption mass spectroscopy.

Fast heavy ions, i.e. 90 MeV 127I from the Uppsala tandem accelerator have been used to desorb and ionize molecules from a cobra venom neurotoxin. The protein is built up by 71 amino acid residues in a single polypeptide chain, tightly cross-linked by 5 disulfide bridges. The molecular weight as confirmed by protein sequence analysis is 7821. The ions were mass analyzed by the time-of-flight technique. This is to our knowledge the largest protein for which it has been possible to detect quasi-molecular ions by a mass spectrometric technique.

Amino Acid Sequence↗

PubMed1983

Evaluation of once daily hydralazine in inadequately controlled hypertension.

Despite the short plasma half-life of hydralazine, once daily Slow Apresoline has been shown to maintain blood pressure control in well controlled hypertension. In the present investigation of 118 inadequately controlled hypertensives, we have shown that 50-150 mg Slow Apresoline once daily induces a significant blood pressure reduction and is well tolerated. Normotension, i.e. supine diastolic blood pressure less than 95 mmHg, was reached in 53% of the patients. Normotension or a supine diastolic blood pressure reduction of greater than or equal to 10 mmHg was achieved in 72% of the patients, the hydralazine responders. Sixteen patients discontinued treatment due to symptoms probably related to hydralazine. Acetylator phenotyping showed that slow acetylators predominated in the group of patients discontinuing hydralazine due to side-effects. In contrast, 90% of the phenotyped non-responders were rapid acetylators, which suggests a suboptimal use of hydralazine in some rapid acetylators.

Adult↗

PubMed1983

Influence of time and physical activity on blood pressure and heart rate during treatment with beta-blocking agents once daily.

In a cross-over study of 52 middle-aged patients with mild to moderate essential hypertension, we have compared the effect and tolerability of 100 mg atenolol and 100 mg metoprolol given once daily. After 1 1/2 and 3 months of treatment, both systolic and diastolic blood pressure 24 hours after drug intake were significantly lower on atenolol. There were no significant differences after 3 months when blood pressure was read 3-4 hours after dose intake. During exercise, systolic blood pressure and heart rate were--at all work-loads--significantly lower on atenolol. Four patients on metoprolol and one patient on atenolol discontinued treatment owing to side-effects. The results support the need for thorough analysis of the duration of action and influence of physical activity and sympathetic tone in comparisons between presumedly equivalent antihypertensive drugs.

Adult↗

PubMed1978

Electrocardiographic changes during total energy deprivation (fasting).

The effect of 10 days of total energy deprivation (fasting) on ECG reactions was evaluated in 14 healthy normal-weight males. The heart rate and the ratios between QRS and T wave amplitudes in leads I and II decreased significantly, as did body weight and blood glucose levels. The urinary excretion of adrenaline increased. It is concluded that other hormonal (e.g. thyroidal), neural and metabolic mechanisms are of greater significance for the heart than the sympatho-adreno-medullary activity during fasting. T wave abnormality without an abnormal Q wave and without other clinical symptoms was noted in one subject on the 8th day of starvation and remained abnormal for more than a year.

Adult↗

PubMed1977

Energy deprivation in man--methodological problems and possibilities.

Various approaches to the study of physiological and behavioural effects of energy deprivation are presented and discussed. An experimental, total energy deprivation in 20 healthy human volunteers during an 11-day period, preceded and followed by 4-day control periods, is described. Potentially pathogenic reactions which occurred in spite of precautions are analysed. It is concluded that the present controlled real-life model with acute total energy deprivation serves the purpose of studying hypotheses concerning potentially pathogenic mechanisms occurring in deprivational situations under conditions of natural and man-made catastrophes.

Adult↗

PubMed1971