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Biomedical subjects

A Danielsson

Publications and source records attributed to A Danielsson.

At least 109 records · Page 6Linked to original sources

Adhesion of bacteria to the human small-intestinal mucosa. A scanning electron microscopic study.

During the period 1 January 1980 to 30 June 1986, a total of 543 small-intestinal biopsy specimens from adults with gastrointestinal symptoms were available for routine analysis with correlated scanning electron microscopy and light microscopy. Adhesion of microorganisms was found in 77 biopsy specimens. Microorganisms in 64 specimens were classified as bacteria, in 10 as microfungi and in 4 as protozoa, including 1 specimen with both bacteria and microfungi. The structural types of bacteria found were morphologically cocciform, 8; short rod-shaped, 14; and long rod-shaped, 43. One specimen demonstrated adhesion of two structural types of bacteria. Bacteria were found in specimens from all age groups in roughly equal frequency. There was no difference in villus structure when comparing specimens from the groups with and without adhering bacteria, whereas ultrastructural alteration--that is, thinning of glycocalyx layer--was significantly more frequent in the group with bacteria. Moreover, within the group of specimens with bacteria the presence of long rod-shaped bacteria was associated with both damage of villus structure and deviation of cell surface ultrastructure. An increased amount of neutrophil granulocytes as an indicator of acute inflammation was found in 6 of 51 specimens with bacterial adhesion but in none of a matched reference material. In contrast, the amount of plasma cells and lymphocytes in the lamina propria and the amount of intraepithelial lymphocytes did not differ.

Adolescent↗

One-step purification of monoclonal IgG antibodies from mouse ascites. An evaluation of different adsorption techniques using high performance liquid chromatography.

Monoclonal antibodies were purified in one step from mouse ascites by four different high performance liquid chromatography (HPLC) adsorption techniques. The antibodies were of the IgG1, IgG2a, IgG2b and IgG3 subtypes, with isoelectric points between 6.4 and 7.6. Similarly pretreated samples were applied to columns for anion exchange (Mono Q), cation exchange (Mono S), chromatofocusing (Mono P) and hydrophobic interaction chromatography (Alkyl Superose), respectively. Highly purified IgG fractions, as judged by electrophoresis, were obtained in all these techniques. The yields of immunoreactive material were above 80%. A strategy for single step HPLC purification of monoclonal IgG antibodies from mouse ascites by adsorption techniques is proposed, as a complement to the well-established technique of affinity chromatography on immobilized protein A. The strategy involves (i) cation exchange chromatography as a first choice for antibodies with high isoelectric points (greater than 7.2), and (ii) hydrophobic interaction chromatography as a first choice when the isoelectric point is below 7.2.

Animals↗

Non-specific secretory supersensitivity in rat parotid gland following neonatal sympathetic denervation.

Newborn rats were surgically sympathectomized by extirpation of the left superior cervical ganglion. After 9 weeks the parotid glands of both sides were used for secretory studies. Isoprenaline, dopamine, and the dibutyryl analogue of cAMP (DBcAMP) caused an increase in amylase release, which was significantly higher in the denervated glands. Also carbamylcholine was more effective in the denervated gland; the concentration-response curve was shifted to the left, and the maximal output of amylase was increased. Neonatal sympathetic denervation induces supersensitivity for both adrenergic and cholinergic agonists as well as for DBcAMP. This may be due to compensatory mechanisms involving both up-regulation of receptors as well as amplification of the intracellular mediation.

Adrenergic Fibers↗

Characterization of dopamine-induced potassium efflux in rat parotid acinar cells.

The effects of dopamine and noradrenaline on potassium efflux from rat parotid gland were studied in a perifusion system. Tissue specimens were preincubated with 86RbCl and the efflux of 86Rb+ was used as a marker for potassium efflux. Noradrenaline induced 86Rb+ efflux more effectively than dopamine. The noradrenaline-induced efflux was inhibited by alpha-adrenoceptor blockers, especially the alpha 1-antagonist prazosin. The dopamine-induced 86Rb+ efflux was blocked by alpha-adrenoceptor antagonists, non-selective dopamine antagonists and a D-1 selective dopamine antagonist. The D-2 selective drug, sulpiride, did not affect the dopamine-induced 86Rb+ efflux. The dopamine effect was abolished when reserpinized animals were used, whereas the effect of noradrenaline was unaffected. The results suggest that dopamine has a presynaptic stimulatory effect in rat parotid gland, and that the presynaptic effect on potassium efflux seems to be mediated via the D-1 receptor subtype. Whether activation of the presynaptic D-1 receptors leads to noradrenaline release, or whether the D-1 receptor is coupled to the catecholamine transporter system remains to be studied further.

Adrenergic alpha-Antagonists↗

Lung function abnormalities in patients with primary biliary cirrhosis.

Twenty-five patients with primary biliary cirrhosis (PBC) in different stages were investigated with respect to pulmonary function abnormalities. The results were compared with a reference sample of 17 sex- and age-matched healthy subjects. A high prevalence of lung function impairment was found in the PBC patients (14/25 [56%]). Bronchial asthma was present in three patients, and severe lung emphysema in one. These four patients had an abnormal lung function, mainly of obstructive type. There was a statistically significant difference between the remaining 21 PBC patients without chronic obstructive lung disease and the reference subjects with respect to diffusion capacity. Almost all abnormal lung function data were found in the symptomatic PBC patients (i.e. symptoms of pruritus, xanthoma, xanthelasmata, jaundice, hyperpigmentation, hepatosplenomegaly), 13 out of 18 (72%), whereas only one out of seven asymptomatic patients was affected. Nine patients (36%) had reduced diffusion capacity compared with none of the reference subjects. The lung function abnormalities in PBC patients are similar to those found in sarcoidosis, another granulomatous disease.

Adult↗

Dopamine actions in vitro on enzyme and electrolyte secretion from normal and sympathectomized rat parotid glands.

1. Adult rats were denervated unilaterally by removal of the left superior cervical ganglion or chemically denervated with 6-hydroxydopamine or reserpine. Two weeks later the parotid glands were used for in vitro secretory studies and their catecholamines and major metabolites were measured. 2. Noradrenaline concentrations were reduced 2 weeks after surgical sympathectomy and reserpine pre-treatment 18 h previously, whereas 6-hydroxydopamine pre-treatment for 3 days reduced both noradrenaline and dopamine concentrations. 3. Dopamine caused a prominent amylase release from incubated control glands. However, a subsensitivity for dopamine-induced amylase release was recorded on the denervated side. 4. Dopamine caused a prominent potassium efflux measured as 86Rb+ efflux from control glands, but was without effect in denervated glands. This is in contrast to noradrenaline-induced 86Rb+ efflux which was equally effective in both denervated and control glands. 5. Dopamine caused [3H]noradrenaline efflux in control glands, but was without effect in surgically denervated glands and in glands pre-treated with reserpine or 6-hydroxydopamine. 6. It is concluded that dopamine-induced potassium release is caused by a presynaptic action on noradrenergic nerves, whereas dopamine-induced amylase release has a presynaptic and a postsynaptic component. The results suggest a specific action of dopamine in salivary glands, with different effects on enzyme release and ionic fluxes.

Amylases↗

Mucin in gall bladder bile of gall stone patients: influence of treatment with chenodeoxycholic acid and ursodeoxycholic acid.

The concentration of hexosamine, a marker for mucin, was determined and related to the degree of cholesterol saturation and to the occurrence of cholesterol crystals in gall bladder bile of gall stone patients (n = 40) and gall stone free subjects (n = 25). Ten of the gall stone patients had been treated with chenodeoxycholic acid (CDCA) and eight with ursodeoxycholic acid (UDCA) three to four weeks before cholecystectomy. The hexosamine content was significantly higher in gall stone patients (137 (19) ng/ml, mean (SE) than in gall stone free subjects (83 (9) ng/ml, p less than 0.02). Treatment with CDCA or UDCA decreased cholesterol saturation, but did not significantly affect the hexosamine concentration. There was no difference in hexosamine concentration between gall stone patients with and without cholesterol crystals. The results do not support the hypothesis that the degree of cholesterol saturation is important for the mucin content of gall bladder bile in man. Neither do the data indicate that the formation and occurrence of cholesterol crystals in gall bladder bile from gall stone patients is caused by an increased concentration of mucin. As the studies were conducted on patients who had already had gall stones for several years, however, an effect of mucin in the very early stage of gall stone formation cannot be completely excluded.

Adult↗

Cardiovascular function and arterial blood gases during sham dialysis in healthy man.

Cardiovascular function and alveolar gas exchange were studied in healthy subjects undergoing sham dialysis (SHD)--i.e. the circulation of blood through a cuprophane dialyzer with the dialysate compartment closed to avoid diffusion and convective transport of fluid and solutes. The blood-membrane contact induced complement activation (rise in C3d) and transient leukopenia, as described during clinical hemodialysis. PaO2, PaCO2 and calculated oxygen uptake remained unchanged. Heart rate, cardiac index (thermodilution), systemic vascular resistance index and brachial and pulmonary arterial blood pressures did not change significantly during 150 min of SHD (n = 8). In 12 subjects, in whom more frequent measurements were made during the first 30 min of SHD, pulmonary arterial systolic and diastolic blood pressures decreased significantly while the dialyzer and the tubing set filled with blood, and pulmonary arterial mean blood pressure did not change significantly. Pulmonary capillary wedge pressure fell during the filling phase, but did not change significantly during SHD; pulmonary vascular resistance index remained unchanged. We conclude that in nonuremic subjects sham dialysis with a cuprophane dialyzer does not result in hypoxemia, pulmonary vascular constriction and pulmonary hypertension, in spite of complement activation and marked leukopenia.

Acid-Base Equilibrium↗

Cardiovascular function and arterial blood gases during isolated ultrafiltration in healthy man.

In order to recognize possible cardiovascular signs of underhydration during isolated ultrafiltration (IUF), we have studied the physiological hemodynamic adaptation to IUF in healthy man both above and below normohydration. In 7 subjects IUF was performed with the subjects in a normohydrated state at the start of IUF. In 8 subjects the IUF was preceded by a 1-hour infusion of Ringer solution equal to 3% of body weight. By invasive techniques, cardiac index (thermodilution), stroke index, heart rate, brachial and pulmonary arterial blood pressures, systemic vascular resistance index, central blood temperature, PaO2 and PaCO2 were measured. Calf vascular resistance was assessed by venous occlusion plethysmography. A recirculation period of 30 min was followed by IUF in both study groups. During IUF with overhydration and normohydration at the start of IUF, cardiac output fell because of a decline in stroke volume and an unchanged heart rate. Blood pressure remained constant because of systemic vascular constriction. PaO2 and PaCO2 remained unchanged. IUF in healthy man is mainly characterized by vascular constriction and an unchanged heart rate. Thus, the cardiovascular adaptation to ultrafiltration was the same whether or not ultrafiltration was performed at overhydration or normohydration at the start of ultrafiltration. Therefore, it is unlikely that monitoring of heart rate or noninvasive recording of blood pressure can predict whether a subject is becoming underhydrated during isolated ultrafiltration. The adaptation to IUF is similar to that observed during the treatment of uremic patients without complications.

Blood Gas Analysis↗

Bile acid malabsorption demonstrated by SeHCAT in chronic diarrhoea, with special reference to the impact of cholecystectomy.

SeHCAT is a gamma-labelled synthetic bile acid, suitable for external measurements and detection of bile acid malabsorption. In this study 138 subjects were investigated with 75SeHCAT. The technique was modified by calculating the biologic half-life of the isotope (WBR-50) within 48 h. All patients with ileocaecal resection had reduced WBR-50 values, as did most (8 of 12) with Crohn's disease affecting the small bowel. Among patients with chronic diarrhoea 24 out of 62 patients had reduced WBR-50 values. Four of the patients with low WBR-50 and one in the group with normal WBR-50 had previously been cholecystectomized. In a consecutive study, 15 patients were investigated before and after cholecystectomy. In 12, WBR-50 decreased after the operation (p less than 0.05). The results demonstrate the impact of cholecystectomy on the interpretation of the SeHCAT retention results. The results may also add to the understanding of diarrhoea secondary to cholecystectomy.

Adult↗

Alkaline phosphatase isozymes in non-malignant intestinal and hepatic diseases.

Human alkaline phosphatase isozymes--the tissue-unspecific, the intestinal, and the placental alkaline phosphatases--were determined in sera by use of isozyme-specific monoclonal antibodies. The clinical utility of serum determinations of alkaline phosphatase isozymes was evaluated in patients with diseases of the gastrointestinal tract and the liver. No elevations of the different serum isozymes were observed in the intestinal diseases investigated (active Crohn's disease and ulcerative colitis). For non-malignant diseases of the liver the alkaline phosphatase isozymes presented characteristic patterns. Patients with cirrhosis due to hepatocellular diseases had markedly elevated levels of intestinal alkaline phosphatase and moderate serum activities of tissue-unspecific and placental alkaline phosphatases. In patients with liver disease with cholestatic features tissue-unspecific and placental isozyme levels were high, but the intestinal isozyme remained normal, whereas primary biliary cirrhosis was associated with high levels of the tissue-unspecific enzyme and moderate elevations of intestinal and placental alkaline phosphatases. It can be concluded that, in addition to tissue-unspecific alkaline phosphatase, intestinal and placental isozymes contribute to the total alkaline phosphatase activity for patients with liver disease. The results suggest that specific methods for the identification of alkaline phosphatase isozymes could be of value.

Alkaline Phosphatase↗

Structure and antithrombin-binding properties of heparin isolated from the clams Anomalocardia brasiliana and Tivela mactroides.

Heparin with high anticoagulant activity was isolated from the two marine clam species Anomalocardia brasiliana and Tivela mactroides. A large portion of the polysaccharide chains of both preparations bound with high affinity to immobilized antithrombin. Titrations monitored by tryptophan fluorescence showed that clam polysaccharide chains with Mr approximately 22,500 contained up to three binding sites for antithrombin and that the binding constants for the interaction of these chains with antithrombin were higher than those reported for mammalian heparin of comparable size. Structural analysis of clam heparin fractions and subfractions of clam heparin with differing affinity for immobilized antithrombin revealed the presence of large amounts (up to 25-30% of the total disaccharide units) of the 3-O-sulfated saccharide sequences (-GlcNSO3)-GlcA-GlcNSO3(3-OSO3)- and (-GlcNSO3)-GlcA-GlcNSO3(3,6-di-OSO3)-, previously identified as unique markers for the antithrombin-binding region of heparin. The content of these saccharide sequences was found to increase with increasing affinity of the parent polysaccharide for antithrombin. Structural analysis of the clam heparins also demonstrated the occurrence of a novel saccharide sequence, tentatively identified as (-GlcNSO3)-IdA-GlcNSO3(3,6-di-OSO3)-, that has not previously been found in heparin or related polysaccharides. The contents of this latter sequence, at most 3-4% of the total disaccharide units, showed no correlation with the affinity for antithrombin.

Animals↗

Nicardipine in the treatment of essential hypertension controlled 6-month-study comparing nicardipine with propranolol at rest and during exercise.

Thirty patients with mild to moderate essential hypertension entered a randomised double-blind parallel group study for 6 months to compare the effects of the new calcium channel blocker nicardipine 90 mg/day and propranolol 240 mg/day. Both drugs reduced systolic and diastolic blood pressures significantly in the supine and in standing positions. After 6 months of treatment, nicardipine had reduced the supine systolic and diastolic blood pressures by 16 and 17 mm Hg, respectively, and propranolol by 15 and 12 mm Hg. While propranolol treatment led to a marked decline in heart rate, nicardipine caused a small but statistically significant increase in heart rate throughout the study. Both drugs reduced blood pressure during maximal exercise, but propranolol had a greater effect. During exercise nicardipine did not affect the heart rate, whereas propranolol dramatically reduced it. Nicardipine did not produce any ECG changes at rest or during exercise. The side-effects for nicardipine were mild and were related to the vasodilatation induced by the drug. No abnormalities in routine blood chemical tests were found for either of the drugs. Nicardipine appears to be an effective single drug treatment for mild to moderate hypertension.

Adult↗

Cardiovascular function and alveolar gas exchange during isovolemic hemodialysis with acetate in healthy man.

In order to elucidate the hemodynamic responses and alveolar gas exchange during isovolemic hemodialysis (IHD), without the influence of the uremic state and its complications, 7 healthy men underwent IHD. The dialysate contained acetate (40 mmol/l) and the sodium concentration was adjusted to the individual's predetermined plasma sodium concentration. By invasive techniques cardiac index (thermodilution), stroke index, heart rate, brachial and pulmonary arterial blood pressures, systemic vascular resistance index, central blood temperature, PaO2 and PaCO2 were measured. Calf vascular resistance was assessed by venous occlusion plethysmography. Plasma acetate was determined. A recirculation period of 30 min was followed by 120 min of IHD. During IHD plasma acetate increased to 2.51 +/- 0.30 mmol/l. Acetate provoked vascular dilatation, which was compensated for by a heart rate-dependent increase in cardiac index. Brachial arterial blood pressure and stroke index remained unchanged. PaCO2 and plasma bicarbonate decreased significantly, PaO2 tended to decrease and blood pH were unchanged. Thus, IHD with acetate in healthy man is mainly characterized by vasodilatation, but no cardiodepressive effects or marked hypoxemia. The adaptation to IHD is similar to that observed during treatment of uremic patients without complications.

Acetates↗

A controlled randomized trial of budesonide versus prednisolone retention enemas in active distal ulcerative colitis.

Sixty-four patients with active distal ulcerative colitis participated in a multicentre, randomized, investigator-blind trial to compare the effect of budesonide enema, 2 mg/100 ml, with prednisolone disodium phosphate enema, 31.25 mg/100 ml. Budesonide is a new potent corticosteroid with a rapid first-pass elimination. The patients were treated for 4 weeks, and the efficacy of the drugs were evaluated by sigmoidoscopy, histology, and subjective symptoms after 2 and 4 weeks. After 4 weeks of treatment 16 of 31 patients (52%) receiving budesonide enema had healed endoscopically, compared with 8 of 33 (24%) (p = 0.045) receiving prednisolone enema. Budesonide was superior to prednisolone in terms of both significantly improved sigmoidoscopic and histologic scores and subjective symptoms evaluated by visual analogue scales. The patients receiving prednisolone had a significant depression of endogenous cortisol levels during the treatment period, but not the patients receiving budesonide. Budesonide enema seems to be a promising therapy for active distal ulcerative colitis and causes no adverse reactions.

Adolescent↗

Patient-related factors influencing the plasma acetate concentration during haemodialysis.

In 44 adult patients, 16 men and 28 women, with chronic renal failure who were dialysed under uniform conditions (Dialyser area 1.2 m2, blood flow 200 ml/min, dialysate flow 500 ml/min, dialysis fluid acetate concentration 35 mmol/l) we determined the plasma acetate concentration after 1 h of haemodialysis (1H-Ac) and 3 h of dialysis (3H-Ac). 1H-Ac was significantly lower than 3H-Ac in both male and female patients, and both mean values were significantly greater in males than in females. 3H-Ac showed a negative correlation with body surface area, serum creatinine before dialysis, and serum albumin, respectively. Using multivariate analysis, body surface area and serum creatinine showed the strongest significant combination of independent variables (R = 0.66), and accounted for 43% of the total variance in 3H-Ac. Sex, age, serum albumin and haematocrit did not further contribute to explaining the variance in 3H-Ac independently of body surface area and serum creatinine. Assuming that serum creatinine to some extent reflects the generation rate of creatinine and thus the muscle mass of the patients, our findings suggest that the rate of metabolism of acetate is proportional to the body size and that acetate is metabolised to a large extent in skeletal muscle. Accordingly, malnutrition with muscle-wasting may lead to slow metabolism of acetate and possibly to exaggerated acetate-related side-effects.

Acetates↗