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Biomedical subjects

R Johnsson

Publications and source records attributed to R Johnsson.

At least 73 records · Page 4Linked to original sources
PubMed1984

Comparison between hemiarthroplasty and total hip replacement following failure of nailed femoral neck fractures focused on dislocations.

The frequency of and the factors causing dislocations of 71 total hip replacements and 59 hemiarthroplasties following failure of nailed femoral neck fractures were investigated. Dislocations were frequent and occurred in four (6%) and seven (l2%) hips respectively. Malposition of the components increased the risk for dislocation. A well-positioned total hip replacement was more stable than a hemiarthroplasty.

Aged↗
PubMed1984

Effects of flunarizine and pentoxifylline on walking distance and blood rheology in claudication.

Thirty-one patients, mean age 60 years (range 45-80 years), with a typical history and objective symptoms of intermittent claudication with a reported maximal walking distance less than 500 m, were included in a cross-over study. After a one month's run-in period on placebo, the patients were randomized into two groups: one group started with flunarizine (5 mg t.i.d.) and the other with pentoxifylline (400 mg t.i.d.). The treatment lasted 3 months, whereafter the medications were changed. The trial followed a double-blind design. The median of the maximal walking distance was 255 m after the placebo period, increasing significantly (p less than 0.01) during both medication periods: by 43% and 18% during flunarizine and pentoxifylline, respectively. No changes were recorded in the ankle systolic blood pressure ratio ( ASBP -ratio) after placebo or either medication period. Red cell rigidity (Pmax), which was initially elevated, decreased significantly (p less than 0.05) during both medication periods, but there were no significant differences between the two drugs. No changes were found in whole blood or plasma viscosity. We conclude that the decrease in red cell rigidity may have contributed to the increased walking distance.

Aged↗
PubMed1984

Total hip replacement with spongious bone graft for acetabular protrusion in patients with rheumatoid arthritis.

Total hip replacement (THR) with the use of autogenous spongious bone graft reinforcement to the medial acetabular wall proved a successful surgical procedure in patients with rheumatoid arthritis and acetabular protrusion. In 25/26 THR followed for an average of 2 (1-4) years, the bone grafts healed in place radiographically and no further protrusion occurred. A non-progressive radiolucent zone of 3 mm at the bone-cement interface occurred around one acetabular cup. Recurrent dislocations occurred in one hip, which eventually turned out to have a loose acetabular cup. One hip with a firmly seated cup was converted to a resection arthroplasty 4 months after the primary operation because of deep infection.

Acetabulum↗
PubMed1983

Erythrocyte flexibility, ATPase activities and Ca efflux in patients with Duchenne muscular dystrophy, myotonic muscular dystrophy and congenital myotonia.

Erythrocyte flexibility measured by a polycarbonate membrane filtration method showed increased fragility (265 +/- 163 Hb mg/l vs. controls 86 +/- 72 Hb mg/l; mean +/- SD; P less than 0.0025) and increased rigidity (123 +/- 96 mm Hg vs. 79 +/- 19 mm Hg; P less than 0.05) in patients with congenital myotonia, while both parameters were normal in patients with Duchenne muscular dystrophy or with myotonic dystrophy. Erythrocyte ghosts obtained from patients with MyD displayed highly significant increases in both (Na+ + K+)-ATPase and (Ca2+ + Mg2+)-ATPase activities (P less than 0.005) and to a lesser extent in Mg2+-ATPase activity (P less than 0.05), while no difference was seen between patients with DMD and age-matched controls. The efflux of Ca2+ was increased from erythrocytes of patients with DMD as compared to age-matched controls (82 +/- 2% vs. 70 +/- 4%; P less than 0.005), while no difference was detected between patients with MyD and age-matched controls.

Adenosine Triphosphatases↗
PubMed1983

Effect of ethanol on blood viscosity and erythrocyte flexibility in healthy men.

The effects of ethanol on blood rheology were studied in twelve healthy male volunteers each serving as his own control. They drank 1.5 g (33 mmol) of ethanol per kg body weight in fruit juice over 2.5 h under controlled laboratory conditions. Blood and plasma viscosity, packed cell volume and erythrocyte flexibility were measured before and 3, 12 and 16 h after ethanol ingestion began, and again during a second session equal volumes of fruit juice were consumed. Packed cell volume varied similarly after ingestion of juice with or without ethanol. Blood viscosity remained almost unchanged after ethanol, while drinking of juice caused an initial decrease followed by a significant (P less than 0.05) increase from 4.04 (SEM 0.06) to 4.32 (SEM 0.18) mPa.s. The juice also caused more significant fluctuations in erythrocyte rigidity (whole blood) than ethanol, which had parallel but insignificant effects. We conclude that a blood ethanol concentration of 28 mmol l-1 failed to induce any marked changes in blood rheology.

Adult↗
PubMed1982

Thrombocyte aggregation in hereditary spherocytosis.

Thrombocyte function was studied in seven splenectomized patients and one unsplenectomized patient with hereditary or congenital spherocytosis (HS). Adenosine diphosphate (ADP) concentrations, which trigger the aggregation of control thrombocytes, induced only a release reaction in thrombocytes from six of the HS patients. Collagen-induced thrombocyte aggregation was also diminished in two patients, and epinephrine-induced thrombocyte aggregation in one patient. Two patients whose thrombocytes responded normally to ADP, collagen and epinephrine, were identical twins with spherocytosis of equivocal hereditary. Ristocetin-induced aggregation was normal in all the patients studied. Xanthines (pentoxifylline, theophylline) had no effect on the aggregation of thrombocytes from HS patients or controls. Half-life of thrombocytes was normal in the two splenectomized patients studied. The results demonstrate that not only red cells but also thrombocytes are defective in HS.

Adenosine Diphosphate↗
PubMed1981

Plasma and erythrocyte lipids in hereditary spherocytosis.

Determinations were made of the concentrations of cholesterol, triglycerides and phospholipids in plasma from 18 patients with hereditary or congenital spherocytosis (HS). The plasma cholesterol and phospholipid levels of these patients were significantly depressed, whereas the triglyceride levels were normal. Phospholipids from plasma and red cell ghosts were analysed by thin-layer chromatography. The relative amount of phosphatidylethanolamine was decreased in both plasma and red cell membranes from HS patients, whereas significant alterations were not observed in the relative amounts of the other major phospholipid classes. These data show that in HS the abnormal lipid metabolism is not confined only to the red cell; it also affects the plasma lipids and therefore probably other cells as well.

Cholesterol↗
PubMed1981

Modified technique in the dorsal approach in total hip arthroplasty.

A modified dorsal approach with osteotomy of a bone shell with the attached short external rotator muscles which are resutured, is described. The advantages have been less dislocations, less sciatic nerve injuries, and an increased operative access. There have been no disadvantages, as increased bleeding or periarticular calcification. The dorsal approach can be used for all conventional total hip arthroplasties and the reported modification seems to be an advantage.

Bone Diseases↗
PubMed1981

Effect of pentoxifylline on red cell flexibility in arterio-sclerotic patients and in patients with heart valve prosthesis.

Red cell flexibility (RCF) was studied in 40 patients with severe occlusive arterio-sclerotic disease of the lower extremities (Group I) and in 17 patients with aortic or mitral valve prosthesis (Group II). RCF was studied in terms of rigidity and fragility using a filtration method. Pentoxifylline, which according to our previous observations increases the flexibility of red cells in healthy subjects, also markedly improved RCF in Group I, particularly in terms of fragility. The pentoxifylline-induced increase in RCF was less marked in Group II; only the rigidity parameter was significantly decreased. Reid et al [11] reported decreased deformability of red cells in patients with intermittent claudication. Since then a few other studies have been published, in which decreased red cell flexibility (RCF) was observed in patients with diabetic vascular disease [1, 4, 9, 12] and cerebral arteriosclerosis [10]. The objective of this study was to compare RCF in patients with widespread arteriosclerosis and heart valve prosthesis, the latter condition inducing a 'pure' mechanical red cell injury. Both patient groups were also studied after the administration of pentoxifylline, a drug known to improve the flexibility of normal red cells--see [6].

Adult↗
PubMed1981

Red cell flexibility and oxygen affinity in patients with angina pectoris and normal coronary arteries.

Plasma viscosity, haemoglobin-oxygen affinity and red cell flexibility were determined in 16 patients who had angina pectoris but no objective evidence for spasms or obstructions in the coronary arteries. Reference data were obtained from healthy controls and from a group of patients with angina pectoris and multivessel coronary artery disease. In the non-coronary angina group mean plasma viscosity (+/- SD) was in the normal range (1.3 leads to 0.06 centipoise). The same was true for haemoglobin-oxygen affinity (P50: 25.9 +/- 1.7 mmHg). Both red cell rigidity (71 +/- 20 mmHg) and red cell fragility (142 +/- 95 mg/l) were significantly higher (p les than 0.0025) than in the control group (54 +/- 10 mmHg and 63 +/- 29 mg/l, respectively). The group with coronary artery obstructions did not differ from the controls. Thus rigid red cells appear to be related to the syndrome of angina pectoris despite normal coronary arteries. In the light of previous findings of local perfusion abnormalities in these patients, inflexible erythrocytes could be an additional factor compromising myocardial capillary flow.

Adolescent↗
PubMed1980

The fluidity gradient in erythrocyte membranes in hereditary spherocytosis: a spin label study.

The fluidity gradient and sulphydryl groups in erythrocyte ghost membranes from healthy subjects and from seven patients with hereditary spherocytosis (HS) were studied by spin label techniques. The mobility of the stearic acid spin labels was lower in the spherocyte membranes, indicating greater stability of the phospholipid layer in these membranes than in those of matched controls. This stabilization was most distinct in the intermediate and deep membrane layers. No clear differences were observed in the protein sulphydryl groups. It is suggested that the decreased cellular deformability characterizing spherocytes reflects altered lipid organization or lipid-protein interaction in the interior of the cell membrane.

Electron Spin Resonance Spectroscopy↗
PubMed1980

Effect of ouabain on osmotic resistance and monovalent cation transport of red cells in hereditary spherocytosis.

The effect of ouabain on the osmotic resistance of red cells from 17 splenectomized patients with congenital or hereditary spherocytosis (HS), from 5 of their relatives suspected of having a subclinical form of the disease and from unsplenectomized and splenectomized normal controls was studied. In red cells from the HS patients and the splenectomized controls a small ouabain-induced decrease in osmotic resistance was seen, whereas in the unsplenectomized controls no such change was observed. The osmotic resistance of red cells from the 5 relatives, on the other hand, was significantly decreased by ouabain. The usefulness of ouabain in unmasking HS in its subclinical form was further tested by studying monovalent cation influx into red cells. The active influx of 86Rb+ into red cells from HS suffers was significantly increased. A similar degree of ouabain-induced inhibition of 86Rb+ transport was seen in all groups studied. The passive influx of 22Na+, which was also increased in HS red cells, was not affected by ouabain in any of the four groups.

Adolescent↗
PubMed1979

Effect of pentoxifylline on red cell flexibility and cation transport in healthy subjects and patients with hereditary spherocytosis.

The effect of pentoxifylline (3,7-dimethyl-1-(5-oxo-hexyl)-xanthine) on the flexibility of red cells was studied using a filtration method in which the red cells are forced, at a constant flow-rate, through a porous polycarbonate membrane. The filtration pressure reflects red cell rigidity and the amount of Hb released from the disrupted cells ('free Hb') red cell fragility. The advantage of this method is that it allows the two important determinants of red cell flexibility, rigidity and fragility, to be studied simultaneously. Pentoxifylline significantly improved normal red cell flexibility both in vivo and in vitro as judged by this method. The impaired flexibility of red cells from patients with congenital or hereditary spherocytosis (HS) was aggravated by pentoxifylline in vitro. A similar effect of pentoxifylline was also observed on red cells from relatives of HS patients. The effect of pentoxifylline on Ca2+ transport and Ca2+-Mg2+-ATPase activity in red cells from normal and HS patients was investigated. Under in vitro conditions pentoxifylline did not affect the Ca2+-Mg2+-ATPase activity of or Ca2+ efflux from normal and HS red cells. Neither the influx of monovalent cations (Na+, Rb+) or the osmotic resistance of normal or HS red cells was affected by pentoxifylline.

Adenosine Triphosphatases↗
PubMed1978

Calcium transport and adenosine triphosphatase activities of erythrocyte membranes in congenital spherocytosis.

Calcium transport from red cells was measured in seventeen patients with congenital or hereditary spherocytosis (HS). The efflux remained at a lower level in resealed ghost cells of patients than in normal cells both in the presence and absence of adenosine triphosphate (ATP). We studied the activities of Ca2+,Mg2+-ATPase, ouabain-sensitive Na+,K+-ATPase, Mg2+-ATPase and Ca2+-(spectrin-)ATPase in cell membranes prepared by washing the cells with hypotonic medium. The mean +/-SD Ca2+,Mg2+-ATPase/Mg2+-ATPase of HS patients was 3.34 +/- 1.06, and 2.81 +/- 0.42 in control subjects. Na+,K+-ATPase/Mg2+-ATPase was 2.38 +/- 0.38 in HS cells compared to 2.01 +/- 0.41 in normal cells. Ca2+-ATPase/Mg2+-ATPase of HS membranes was 0.57 +/- 0.18 and the control value 0.43 +/- 0.08. These data indicate calcium retention in the erythrocytes of HS patients in spite of increases in Ca2+,Mg2+-ATPase activity in the majority of patients.

Adenosine Triphosphatases↗
PubMed1978

Studies on red cell flexibility in spherocytosis using a polycarbonate membrane filtration method.

A method for studying red cell flexibility as reflected by red cell rigidity and fragility is described. Using an infusion pump, suspended red cells are filtered through a polycarbonate membrane with 3 micron pores. The filtration pressure, which is continuously monitored, is considered to reflect red cell rigidity. The hemoglobin released by the disruption of red cells passing through the membrane is regarded as an indirect measure of red cell fragility. In all of the patients with hereditary spherocytosis studied and in some of their symptomless relatives, the decreased flexibility observed was associable with increased rigidity of the red cell. In vitro effects of chlorpromazine and vinca alkaloid on red cell flexibility were also studied. High concentrations of chlorpromazine and vinblastine induced formation of spherocytes displaying altered cell flexibility.

Adult↗