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Biomedical subjects

B Jacobsson

Publications and source records attributed to B Jacobsson.

At least 109 records · Page 6Linked to original sources
PubMed1986

Cardiac arrhythmias in familial amyloid polyneuropathy during anaesthesia.

There is an increased risk of anaesthetic complications in patients with myocardial disorders. The present paper concerns seven patients with familial amyloid polyneuropathy, who developed severe bradycardia or heart block during anaesthesia. Amyloid infiltration of the cardiac conducting tissues probably increases their susceptibility to anaesthetic agents. Dysfunction of autonomic nerves may also diminish cardiac impulse formation and conduction. In addition, the possibility of contributing succinylcholine-induced hyperkalaemia cannot be excluded. There was a prompt response to infusion of isoproterenol in all patients so treated, but the insertion of a temporary pacemaker prior to anaesthesia should, nevertheless, be seriously considered in this group of patients.

Adult↗
PubMed1986

Unmasking antigen determinants in amyloid.

Rehydrated paraffin sections of formalin-fixed, amyloid-containing tissues were treated with denaturing agents (guanidine and urea) and reducing agents (DDT and mercaptoethanol) before immunostaining, in an attempt to expose antigenic determinants hidden in the rigid structure of amyloid fibrils. Pre-treatment overnight with 6 M guanidine or urea was found beneficial, especially in specimens from familial amyloid polyneuropathy of the Portuguese type. Addition of reducing agents had no major effect. Modifications of this method may be useful in unmasking other antigens that are polymerized or considered destroyed by fixation and paraffin embedding.

Amyloid↗
PubMed1986

Monoclonal antibodies to transthyretin.

Monoclonal antibodies (mabs) have been raised against human transthyretin (hTTR). The protein was isolated by an affinity chromatography procedure using Sepharose-hRBP and BALB/c mice were immunized. Following fusion with SP 2/0 myeloma cells, 26 single cell clones producing antibodies against hTTR were isolated. These mabs have been characterized and efforts have been made to establish the epitopes that they recognize. So far at least two different epitopes have been identified both residing in a mid-region fragment corresponding to the amino acid sequence 35-103 of the hTTR subunit. All mabs have been found suitable for immunohistochemical localization of hTTR even in formaldehyde fixed and paraffin embedded tissues.

Animals↗
PubMed1986

One year's incidence of school accidents and their severity in a Swedish municipality.

The aim of this one-year investigation of school accidents was to determine the incidence and severity and to calculate the proportion of school accident cases in relation to all accident cases and to estimate their medical care consumption. All patients were interviewed. The degree of severity was evaluated according to the Abbreviated Injury Scale (AIS). Case-histories and X-ray reports were examined. School accidents constituted five per cent of all accidents in the whole population (including grown ups). In the age group 7-19 years 30% of all accidents were school accidents. One fourth was relatively severe. Our estimations assume that school accidents constitute 5-10% of the total consumption of medical care in the age group. In conclusion, school accidents constitute an important group with regard to incidence and severity. Preventive measures should be targeted towards activities during sports hours and breaks.

Accidents↗
PubMed1986

Rarefied femoral neck trabecular patterns, fracture displacement, and femoral head vitality in femoral neck fractures.

Before operation, 99mTc-MDP scintimetry was performed in 103 patients with femoral neck fractures. There was a significant correlation (r = 0.63, p less than .01) between osteoporosis and fracture displacement, but no correlation (r = 0.07, p greater than .01) between femoral neck trabecular bone patterns and femoral head viability and no correlation (r = 0.11, p less than .01) between fracture displacement and femoral head viability.

Female↗
PubMed1985

Factors influencing the incidence of reoperation after femoral neck fractures.

This investigation compares two groups of patients with fractures of the femoral neck: 22 required a further operation and 72 did not. Special attention was paid to osteoporosis, the displacement of the fracture, viability of the femoral head, operative impaction and osteosynthesis with a Thornton nail or three Scand hip pins. There was a significant (p less than 0.01) difference between the two groups with regard to osteoporosis, fracture displacement and viability of the femoral head. Scand hip pins, as compared to Thornton nails, showed a tendency (p less than 0.1) to need a smaller number of reoperations. Operative impaction compared with no impaction showed no difference.

Aged↗
PubMed1985

Cushing's syndrome due to an ACTH-producing neuroendocrine tumour in the nasal roof.

A patient with ectopic adrenocorticotrophic hormone (ACTH) production from a neuroendocrine tumour of the nasal roof is presented. By indirect immunoperoxidase techniques the tumour cells were shown to be distinctly positive for ACTH and beta-endorphin but negative for other peptides derived from pro-opiomelanocortin. Neither corticotropin releasing hormone (CRF) found in some tumours associated with ectopic Cushing's syndrome, nor gastrin immunoreactivity, which coexists with ACTH in normal rat pituitary and in rat and human gastrointestinal cells, were demonstrable in the tumour. A review of other, previously recognized locations of CRF/ACTH producing tumours is given to increase the awareness of the ectopic Cushing's syndrome, which may lack the classical features and is characterized by fulminant clinical course, extreme fatigue, weakness, pale facial swelling, oedema and hypokalaemic alkalosis.

ACTH Syndrome, Ectopic↗
PubMed1985

Abnormality of adenylate cyclase regulation in human platelet membranes in renal insufficiency.

Adenylate cyclase in human platelets is under dual control of prostaglandins (PGI2 and PGE1) and catecholamines. The adenylate cyclase complex in membranes of platelets from ten patients with uraemia was investigated. The activation of the platelet cyclase by PGE1 is increased in the uraemic state, Vmax 4436 +/- 607 pmol cAMP mg-1 15 min-1. In the normal state Vmax is 2098 +/- 309 pmol cAMP mg-1 15 min-1. The alpha 2-adrenergic receptor was assayed with 3H-yohimbine binding. The density of receptors was equal in the uraemic (175 fmol mg-1 membrane protein) and the normal (170 fmol mg-1 membrane protein) states. Norepinephrine/3H-yohimbine competition binding revealed that catecholamines were bound with normal affinity in platelets in uraemia. Yet the inhibition of adenylate cyclase through the alpha 2-adrenergic receptor was diminished since Vmax values of adenylate cyclase with PGE1 and PGE2 + norepinephrine did not significantly differ. In the normal state, norepinephrine significantly (P less than 0.05) inhibited the PGE1 stimulated cyclase. It is concluded that platelet adenylate cyclase in the uraemia has an increased capacity for activation which is the result of both a sensitized stimulatory mechanism (prostaglandin mediated) and a deficient inhibitory mechanism (catecholamine mediated). It is suggested that a defect exists in the inhibitory nucleotide binding protein (NI) which is the coupling unit between the adenylate cyclase catalytic subunit (C).

Adenylyl Cyclases↗
PubMed1985

Adenylate cyclase modulation by ammonium ion: GTP-like effect on muscarinic and alpha 2-adrenergic receptors.

The stimulatory influence of ammonium sulphate on adenylate cyclase activity has been investigated. By competition binding experiments on the beta-adrenergic stimulatory receptor in rat myocardial membranes, no influence could be detected of ammonium sulphate neither in receptor coupling to the stimulatory guanine nucleotide binding protein nor in the GTP-induced uncoupling. In order to detect an impaired inhibition instead of an increased stimulation of adenylate cyclase activity by ammonium sulphate the investigation was extended to inhibitory receptors. The same type of effect by ammonium sulphate was detected on both the muscarinic cholinergic receptor in rat myocardial membranes as well as on the alpha 2-adrenergic receptor in human platelets. The influence of ammonium sulphate noted in competition binding studies and off-kinetics experiments was GTP-like, i.e. causing a decrease in agonist-receptor affinity leaving all the inhibitory receptors in the low affinity state. In conclusion, this paper indicates that the observed stimulatory effect of ammonium sulphate is exerted by the ammonium ion on the inhibitory guanine nucleotide binding protein, impairing the negative control of adenylate cyclase activity.

Adenylyl Cyclases↗
PubMed1985

Femoral head vitality after peroperative impaction of hip fractures.

In 94 patients with femoral neck fracture the vitality of the femoral head was determined pre- and postoperatively with 99mTc-MDP-scintimetry. In half of the fractures a Thornton nail was used, in the other half three Scand hip pins. Irrespective of the displacement, no difference was noted in the two groups. In half of the operations in each group the fracture was impacted by hammer at the end of the operation. In displaced fractures, impaction caused a decrease in femoral head vitality.

Aged↗
PubMed1984

Renal growth after antireflux surgery in infants.

Thirteen children (eleven boys and two girls) with fifteen refluxing ureters have been operated upon during infancy and been followed between five and seven years postoperatively. Kidney growth has been studied by determining renal parenchymal area by planimetry. 14/15 were free from reflux at follow-up. Postoperative vesicoureteric obstruction was found in one infant. In the cases where the kidney had a pronounced parenchymal reduction at presentation poor kidney growth was demonstrated. However, the nine kidneys which had a smaller parenchymal reduction at presentation normal showed growth postoperatively.

Age Factors↗
PubMed1984

Effects of acute ketotic and non-ketotic diabetes on the myocardial muscarinic receptors.

Myocardial membranes from rats rendered diabetic with streptozotocin were used to determine muscarinic receptors with 3H-quinuclidinyl benzilate. In the acute state of diabetes, four days after induction, the density of receptors were equal in controls, insulin (glucosuria) and non insulin-treated (glucosuria and ketonuria) diabetic animals. In myocardial membranes from diabetic rats agonist binding to the muscarinic receptor was shifted to higher affinity than in controls. Computer modeling revealed that guanine nucleotides transformed agonist binding from two sites to a site of low affinity in controls. In membranes from insulin-treated diabetic animals the shift to lower affinity occurred but two receptor sites remained. In non insulin-treated membranes the nucleotides failed to exert any effect. Inhibition of adenylate cyclase by the muscarinic agonist oxotremorine was amplified in diabetic membranes. This indicates that the function of the inhibitory nucleotide binding protein (NI), as reflected by agonist binding to the receptor and adenylate cyclase inhibition, is sensitive to the hormonal status.

Adenylyl Cyclase Inhibitors↗
PubMed1983

Correlation of P blood group, vesicoureteral reflux, and bacterial attachment in patients with recurrent pyelonephritis.

Bacterial attachment to urinary-tract epithelium is important in the pathogenesis of urinary-tract infection. Most pyelonephritogenic Escherichia coli bind specifically to epithelial-cell receptors, which are glycolipids of the globoseries and also antigens in the P blood-group system. Among 36 girls with recurrent pyelonephritis who did not have vesicoureteral reflux, we found that attaching bacteria were common and the P1 blood-group phenotype was present in 97 per cent, as compared with 75 per cent of 84 age-matched children without urinary-tract infection (P less than 0.01). In 32 girls with recurrent pyelonephritis who had reflux, attaching bacteria were rare, and the frequency of the P1 phenotype was not significantly higher than in controls (82 per cent, P greater than 0.05). In the group of patients with the P1 phenotype, 68 per cent of the urinary bacterial isolates from those without reflux, but only 25 per cent of isolates from those with reflux, bound to globotetraosylceramide, as determined by a receptor-coating technique (P less than 0.001). Our data suggest that, in the absence of reflux, the P1 blood group contributes to susceptibility to recurrent pyelonephritis due to bacteria that bind to the glycolipid receptors of the globoseries. In the presence of reflux, uroepithelial attachment does not seem to confer an advantage to bacteria that infect the kidney.

Adhesiveness↗
PubMed1983

Non-ionic contrast media in cardioangiography in infants. A comparison of iohexol and metrizamide.

Iohexol (300 mg I/ml) was compared with metrizamide (300 mg I/ml) in pediatric cardioangiography. Forty consecutive patients below one year of age were included in an open, randomized, comparative two-group investigation. Immediate extrasystoles occurred frequently at injections of contrast medium, but the frequency did not differ significantly between metrizamide and iohexol. Both contrast media caused only minor changes in heart rate. Iohexol caused a significantly larger increase in end diastolic pressure following injections in the left ventricle than did metrizamide. The pressure changes registered were, however, moderate in both contrast media groups and the difference between the two contrast media is probably of no clinical importance. A moderate plasma volume expansion was noted after injection of both contrast media. Metrizamide caused a slight increase of ASAT in the 10 min blood sample which differed significantly from that of iohexol, but no increase of enzyme activity was noted after 24 h and the change was considered to be of no clinical importance. Image quality was similar with both contrast media. Iohexol and metrizamide were well tolerated in pediatric cardioangiography.

Angiocardiography↗
PubMed1982

The importance of neonatal asphyxia and caesarean section as risk factors for neonatal respiratory disorders in an unselected population.

The risk of neonatal respiratory disorders was calculated in an unselected, total population together with the relative contributions of some factors found associated with an increased risk. Postnatal asphyxia, expressed as a low one minute Apgar score, and low gestational age were substantially, independent risk factors. Caesarean section added, though less markedly, to the risk of the above disorders.

Apgar Score↗