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Biomedical subjects

K Olsson

Publications and source records attributed to K Olsson.

At least 55 records · Page 3Linked to original sources
PubMed1996

Responses to systemic angiotensin II in lactating and non-lactating goats.

This study aimed at investigating whether lactation affects the dipsogenic, hypertensive and volumetric effects of angiotensin II (Ang II) in a low-yielding goat adapted to arid conditions. Six black Moroccan goats were given intravenous infusions of Ang II at 8 ng kg-1 min-1 for 90 min during lactation and a non-lactation period. To further test the dipsogenic response, 5 of them were given Ang II at the consecutively increasing doses 10, 20, 50 and 100 ng kg-1 min-1 (10 min at each dose). The body weight was 32 +/- 1 kg in both periods and the daily milk production was 22 +/- 2 ml kg-1. No drinking was observed during infusions of Ang II in any of the goats. The rise of the mean arterial pressure to Ang II was attenuated in lactating animals and this was not steroid-dependent since the plasma progesterone level was low (< 0.2 nmol 1(-1)). Total plasma protein concentration decreased during Ang II infusions, and the ratio albumin/total proteins was unchanged, indicating that haemodilution had occurred. It is concluded that Ang II does not elicit drinking in the arid adapted Moroccan goats and we suggest that these goats have an elevated thirst threshold. However, haemodilution and an attenuated blood pressure response to Ang II occur in the lactating Moroccan goat, as has previously been observed in high-yielding Swedish domestic goats.

Angiotensin II↗
PubMed1996

Reproductive period affects water intake in heat-stressed dehydrated goats.

Water intake following dehydration was studied in pregnant (N = 5), lactating (N = 4) and nonpregnant, nonlactating (N = 5) Swedish domestic goats (Capra hircus) to investigate if reproductive period affected drinking. Plasma cortisol concentration and the hematocrit value were measured to evaluate stress. The goats were water deprived from 9.00 h until 15.05 h the next day. They were fed at 7.00 and 15.20 h. On the second day, ambient temperature was increased from 20 degrees C to 38-39.5 degrees C for 5.15 h to accelerate water losses. Water temperature during rehydration was 35 +/- 1 degree C. Plasma Na concentration and osmolality increased most in dehydrated and heat-stressed pregnant and lactating goats. Pregnant goats lost 2.2 kg of their body weight. They drank 3.5 l immediately, followed by 2.5 l during afternoon eating. Lactating goats lost 4.9 kg and drank 6.3 l at once, and 3.9 l during feeding. Nonpregnant, nonlactating goats lost 1.7 kg and drank 2.6 l followed by 0.6 l. The large water consumption in pregnant and lactating goats caused hyponatremia and hemodilution, but they continued to drink during the night (0.5 +/- 0.2 l and 0.8 +/- 0.5 l, respectively). Renal free water clearance increased in all periods, with a long-lasting water diuresis during pregnancy. Plasma cortisol concentrations and the hematocrit values rose in connection with water intake. These results imply that the thirst center became less sensitive to inhibitory signals from the oropharyngeal tract and the diluted blood plasma during pregnancy and lactation. Catching sight of water was the most exciting procedure during these experiments.

Animals↗
PubMed1996

The preference for warm drinking water induces hyperhydration in heat-stressed lactating goats.

The aim of this study was to determine whether lactating goats regulate their water intake when given a choice between warm (35 degrees C) and cold (15 degrees C) water. Six lactating goats were kept individually in pens. At 07.00 h one bucket was filled with warm water and another with cold water. Water consumption was measured at intervals until 18.00 h. Water temperature was not controlled at night. Two experiments were made, one at normal room temperature (18-19 degrees C) and the other at 39-40 degrees C from 10.45 to 17.00 h. At normal room temperature the goats drank 6.0 +/- 1.4 L of the warm water but only 1.7 +/- 1.3 L of the cold water (P < 0.001). The total water consumption, including the following night, was 9.2 +/- 1.6 L. This differed from control days, when only cold water was available (5.9 +/- 0.4 L; P < 0.05). Neither the plasma Na concentration nor the osmolality changed, which indicate that the goats regulated their fluid balance. In the experiments involving heat stress the goats drank 11.5 +/- 1.7 L of the warm water but only 2.0 +/- 1.0 L of the cold water (P < 0.001). In total, including the following night, they drank 16.2 +/- 2.6 L (P < 0.001 vs. control days). Goats drank repeatedly despite falling plasma Na and osmolality, proving that their thirst was not induced by water losses. Their abdomens became distended, indicating that water was stored in the reticulo-rumen and explaining why their body weights increased. The goats appeared distressed. It is concluded that goats prefer to drink warm water. Nevertheless, our results suggest that, if possible, warm drinking water should not be given to lactating goats under hot ambient conditions.

Animals↗
PubMed1996

Evaluation of platelet function using the in vitro bleeding time and corrected count increment of transfused platelets. Comparison between platelet concentrates derived from pooled buffy coates and apheresis.

The functional capacity of transfused platelets was evaluated with in vitro bleeding time (IVBT) and corrected count increment (CCI) in order to compare platelet concentrates (PCs) derived from pooled buffy coats (BC-PCs) with PCs collected by apheresis (A-PCs). The suspension medium in the BC-PCs was 30% CPD plasma and 70% of an additive solution (containing sodium and potassium chloride, sodium citrate and phosphate, mannitol), and in the A-PCs the medium was 100% CPD plasma. IVBT was evaluated using a Thrombostat 4000/2. BC-PC and A-PC were transfused 57 and 41 times, respectively to 36 patients with chemotherapy-induced thrombocytopenia. PCs transfused within 2 days of donation were considered fresh, and those transfused within 3-5 days were considered stored. IVBT was determined before, as well as 10-30 min and 24 h after transfusion; CCI was determined 10-30 min and 24 h after transfusion. The median pretransfusion IVBT value was 486 s. It was measurable in 21 of 98 (21%) of the transfusions, i.e. below the cutoff limit of 486 s. Ten to 30 min after transfusion, the IVBT showed a measurable reduction in 90% of the transfusions with fresh BC-PCs, 92% of those with fresh a-PCs, 63% of those with stored BC-PCs and 79% of those with stored A-PCs. After 24 h, the corresponding values were 63% for fresh BC-PCs, 50% for fresh A-PCs, 26% for stored BC-PCs and 38% for stored A-PCs. The median value of CCI 10-30 min after transfusion was 20 for fresh BC-PCs, 17 for fresh A-PCs, 16 for stored BC-PCs and 14 for stored A-PCs. The difference in IVBT between fresh and stored BC-PCs was significant (p = 0.032), unlike that between fresh and stored A-PC. After 24 h the corresponding values were 7 for fresh BC-PCs, 4 for fresh A-PCs, 4 for stored BC-PCs and 3 for stored A-PCs. When all transfusions with fresh PCs (BC-PCs + A-PCs) were compared with all transfusions with stored PCs, a statistical difference was demonstrated in both CCI (p = 0.027) and IVBT (p = 0.043). Spearman's rank correlation coefficient (rs) was -0.41 between CCI and IVBT < 486 s 10-30 min after transfusion, and -0.55 between the posttransfusion platelet count and IVBT, indicating a relatively poor correlation between CCI and IVBT, and a slightly better correlation between platelet count and IVBT. In conclusion, BC-PCs showed a slightly higher CCI and a better response in IVBT than A-PCs. No statistical difference was demonstrated between BC-PCs and A-PCs transfused within 2 days after donation, with respect to function and recovery in vivo. BC-PCs stored for 3 days or more showed about the same CCI and IVBT as stored A-PC but significantly lower CCI and higher IVBT than fresh BC-PCs. This may indicate that the preparation and/or storage conditions were not optimal. IVBT seems to be a useful possibility to test the in vivo behavior of transfused platelets.

Adolescent↗
PubMed1996

Keratouveitis--two families with a dominantly inherited disorder.

Herein we describe a relapsing acute keratouveitis without known aetiology. The disorder has been found in two families and shows an autosomal dominant inheritance. Acute anterior uveitis can be traced for five generations in one of these families. In the same family there is also an association to an autosomal dominantly inherited vascular disorder (Osler-Rendu-Weber disease). The anterior uveitis has an acute onset, a recurrent pattern and a mild activity. The associated keratitis is seen as a midstromal thin flat disc in the central cornea, sometimes with folds in Descemet's membrane as a sign of oedema. This causes a change in refraction and a mild reduction of the corrected visual acuity. There is a prompt response to topical steroid treatment, but the corneal changes have in one case become permanent. Clinical documentation and the mode of inheritance is presented.

Acute Disease↗
PubMed1996

A long term study of goats naturally infected with caprine arthritis-encephalitis virus.

The caprine arthritis-encephalitis virus (CAEV) is a big problem in dairy goat industry. Little is known about its characteristics in naturally infected goat herds. The aims of this study were: 1) to study how antibody expression, measured by agar gel immunodiffusion test (AGIDT), varied over time in naturally infected, seropositive goats, 2) to observe clinical signs in seropositive adult goats and 3) to follow seroconversion and gamma globulin concentration in goat kids artificially reared on cow milk replacement product only, compared to kids reared on untreated goat milk. The antibody expression pattern to the viral proteins gp135 and p28 varied in the individual goat and intermittent negative reactions were seen in 19 adult animals followed for 30-91 weeks. Four seropositive goats developed clinical symptoms with difficulties to move. However, no correlation between clinical signs and antibody expression pattern was seen. During the first 27 weeks of age no kid in the milk replacement reared group (N = 4) seroconverted, but 5 of the 7 kids fed goat milk occasionally showed a positive antibody reaction. The gamma globulin concentration was significantly higher in the goat milk fed group until the kids had become more than 19 weeks old. The results show that a great variation of the antibody pattern in individual goats occurs, and therefore the AGIDT is only reliable as a herd screening test. Frequent sampling is necessary to get reliable information about spreading of the CAEV in a naturally infected goat herd. Removing kids from their dams immediately after birth combined with segregation and artificial rearing protected them from CAEV infection. However their gamma globulin concentration was initially low.

Animals↗
PubMed1996

Effects of long-term treatment with enalapril or hydralazine on the renin-angiotensin-aldosterone system and fluid balance in dogs with naturally acquired mitral valve regurgitation.

OBJECTIVE: To study long-term effects of enalapril, an angiotensin-converting enzyme inhibitor, and hydralazine, an arteriodilator, on renin-angiotensin-aldosterone system and fluid balance before and after administration of furosemide. ANIMALS: 22 dogs with clinical signs of congestive heart failure (CHF) attributable to mitral regurgitation. PROCEDURE: After initial examination, 12 dogs received enalapril and 10 received hydralazine. Dogs were re-examined 3 weeks and 6 months after initial examination. Furosemide was added after the 3-week examination, and at 6 months, dogs had received furosemide for at least 4 months. RESULTS: Angiotensin II and aldosterone plasma concentrations were low before treatment, and only aldosterone became significantly decreased after enalapril monotherapy. Concentrations of both hormones and heart rate increased in dogs receiving hydralazine monotherapy, and fluid retention was evident. After long-term treatment with either of the 2 drugs together with furosemide, angiotensin II and aldosterone values increased in both groups. Natriuresis and kaliuresis developed in all dogs, with greatest effect in those receiving enalapril and furosemide. These dogs had decreased plasma sodium concentration, whereas potassium concentration was equally decreased in both groups. After 6 months, the enalapril group, but not the hydralazine group, had increased cardiac size. All dogs had moderate reduction of weight and were azotemic, although changes were more pronounced in those of the hydralazine group. CONCLUSION: The 2 drugs have different effects on the renin-angiotensin-aldosterone system and fluid balance in dogs with CHF.

Aldosterone↗
PubMed1995

Heat stress causes excessive drinking in fed and food deprived pregnant goats.

Water intake was studied in six goats during late pregnancy to investigate if heat stress induces primary polydipsia. The goats were fed twice daily or deprived of food for 24 hr to avoid postprandial drinking and induce hyponatremia. Signs of stress was evaluated by determination of plasma cortisol concentration. Ambient temperature was increased from 20 degrees C to 38.0-39.5 degrees C for 5.15 hr. Water temperature was 35 +/- 1 degree C during heat stress. Fed goats started to drink 13 +/- 3 min after the heaters were turned on and water diuresis developed in five of them. The body weight increased simultaneously with decreased plasma Na concentration and osmolality showing that the goats also stored water. During food deprivation, plasma Na concentration and osmolality fell, and plasma aldosterone concentration increased. Despite hyponatremia, food deprived goats started to drink 44 +/- 15 min after the heaters were turned on and then they drank repeatedly. Three of them underwent water diuresis. Hemodilution was observed both in fed and food-deprived goats during heat stress. These results show that heat stress induced primary polydipsia in pregnant goats. It is suggested that stimulating signals from warmth receptors overrode inhibiting influences from receptors signalling hyponatremia and hypoosmolality at the "thirst center" in the hypothalamus. Heat stress did not increase plasma cortisol concentration, but catching sight of food caused an abrupt, short-lasting elevation.

Aldosterone↗
PubMed1995

Preoperative evaluation of primary hemostasis in patients with thrombocytopenia using the Thrombostat 4000.

It is difficult to estimate the risk of hemorrhage that may follow an invasive or surgical procedure in patients with thrombocytopenia or platelet dysfunction. Conventional functional tests for the evaluation of primary hemostasis have been questioned. We have evaluated the in vitro bleeding time (IVBT) using the Thrombostat 4000 in 25 patients with thrombocytopenia in order to estimate the risk of bleeding following an invasive or surgical procedure. Using the IVBT, it was possible to suggest and evaluate preoperative treatment in order to restore primary hemostasis. All patients studied had their operations without bleeding complications. From these observations we conclude that the IVBT is a convenient and useful tool in the evaluation of primary hemostasis in these patients.

Adult↗
PubMed1995

Influence of amino acids on the formation of mutagenic/carcinogenic heterocyclic amines in a model system.

Mixtures of creatinine, glucose and various single amino acids were heated at 180 degrees C for 10 min in an aqueous model system. The heated mixtures all showed mutagenic activity, ranging from 80 to 2400 TA98 revertant colonies/mumol creatinine with metabolic activation. Testing of HPLC fractions for mutagenic activity showed each mixture to contain several mutagenic components, some of which corresponded to known heterocyclic amines and others to unknown compounds. The presence of 2-amino-3-methyl-imidazo[4,5-f]quinoxaline, 2-amino-3,8-dimethylmidazo[4,5-f]quinoxaline and 2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline in most of the samples was established using HPLC with photodiode array detection and liquid chromatography/mass spectrometry with electrospray interface and single ion monitoring. In addition, 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline, 2-amino-1-methyl-6-phenylimidazo[4,5-f]quinoxaline, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole and 3-amino-1-methyl-5H-pyrido[4,3-b]indole and the co-mutagenic compounds 9H-pyrido[3,4-b]indole and 1-methyl-9H-pyrido[3,4-b]indole were detected in some samples.

Amines↗
PubMed1994

Discrepant effects of angiotensin II and phenylephrine on plasma volume in conscious goats.

Pressor doses of angiotensin II induced haemodilution in goats despite renal fluid losses. This study was undertaken to determine if this response is dose-dependent and correlated to the vasoconstrictor action of angiotensin II. Angiotensin II at the doses 0.025, 0.05 and 0.1 micrograms min-1 was given intravenously to five goats. Mean arterial blood pressure increased by 3, 10 and 20 mmHg, respectively, and the renal Na excretion rose. The haematocrit decreased by 7, 10, and 9% (percentage of control values) and the plasma protein concentration by 1% (n.s.), 4.5, and 3.5%, respectively. Infusions of phenylephrine (40 micrograms min-1; n = 6) caused an equivalent increase of blood pressure and renal Na excretion as angiotensin II (0.1 micrograms min-1), but the haematocrit increased by 16% and the plasma protein concentration by 6.5%. Infusions of atrial natriuretic peptide (1 microgram min-1) alone or together with angiotensin II (0.1 microgram min-1), or phenylephrine were also given (n = 6). Infusions of atrial natriuretic peptide alone did not change blood pressure, but renal Na excretion increased. The haematocrit rose by 10.5% and the plasma protein concentration by 7.6%. Adding atrial natriuretic peptide to the angiotensin II solution attenuated the rise of MAP and counteracted the haemodilution, but did not decrease the natriuresis. Infusions of phenylephrine plus atrial natriuretic peptide caused similar elevations of blood pressure and renal Na excretion as phenylephrine alone. The haematocrit rose by 24% and the plasma protein concentration by 13%. These results show that in the intact conscious goat rapid and marked changes in haematocrit and plasma protein concentration can be provoked by intravenous infusions of vasoactive agents and that these effects are not correlated to changes in arterial blood pressure or renal Na excretion.

Angiotensin II↗
PubMed1994

Tendon arthroplasty for treatment of trapeziometacarpal arthrosis.

Trapeziometacarpal arthrosis is common among middle-aged women, and the surgical treatment options include arthrodesis, excision of the trapezium, prosthetic replacement of the trapezium, reconstruction of the ligaments, and various tendoplasties. We have prospectively studied a simple tendoplasty in which a strip of abductor pollicis longus tendon was anchored to the flexor carpi radialis tendon, the intact part of the abductor pollicis tendon, and the joint capsule, after excision of the trapezium, and carried out 27 operations in 25 patients. The thumb was immobilised for only eight days. Systematic exercises were started on the day of operation. Complete pain relief was obtained in 17 patients and partial relief in eight. Grip strength improved. The mobility was unaltered and functionally satisfactory. Three patients were reoperated on for cutaneous nerve entrapment and one for carpal tunnel syndrome. The procedure is simple, and the patients' symptoms improved without failures. The intensive supervised postoperative physiotherapy was essential to achieve the final results.

Adult↗
PubMed1994

Intraruminal fluid administration to goats: effects of handling and fluid temperature.

Physiological stress response to intraruminal fluid administration was studied in 5 female goats. The fluid was given through a stomach tube. The water was cold (10 degrees C) or warm (38 degrees C) and in an amount of 7.5-10% of body weight. Plasma concentrations of adrenaline, noradrenaline and cortisol increased significantly after both treatments. Adrenaline and noradrenaline responses were greater and more longlasting after cold water administration, but there was no difference in cortisol response between cold and warm water. Haematocrit and plasma protein concentrations increased also and the effects of cold water lasted longer. Blood pressure showed a sharp rise of short duration and was independent of water temperature. The immediate tachycardiac response was similar with both treatments, but cold water caused an additional peak 15 min later. The cooling did not increase plasma histamine level. The results suggest that stomach intubation and administration of water into the rumen leads to strong activation of hormonal and cardiovascular stress parameters even in goats well adapted to handling. Low temperature of the fluid further heightens the effect. Warming of fluids to near body temperature before their administration is thus recommended.

Animals↗
PubMed1994

Plasma concentration of atrial natriuretic peptide in relation to severity of mitral regurgitation in Cavalier King Charles Spaniels.

Plasma concentration of immunoreactive atrial natriuretic peptide (ir-ANP) was investigated in 83 Cavalier King Charles Spaniels with variable severity of mitral regurgitation caused by chronic valvular disease (CVD). Severity of mitral incompetence was assessed by echocardiography. Significant differences in plasma concentrations of ir-ANP were not found between clinically normal dogs (New York Heart Association functional class O), dogs with only cardiac murmur (class I), and dogs with echocardiographic evidence of slight to moderate left atrial and ventricular dilatation (class II). Dogs with severe left atrial and ventricular dilatation and clinical signs of congestion (classes III and IV) were found to have significantly (P < 0.001) increased plasma concentration of ir-ANP. Overall, moderate degree of association was found between plasma concentration of ir-ANP and left atrial and left ventricular diameters (Pearson's r = 0.65, 0.60, respectively, P < 0.001), as well as heart rate (r = 0.47, P < 0.01). However, left atrial enlargement was found to have the predominant effect on plasma ir-ANP concentration. It is concluded that the plasma concentration of ir-ANP did not become markedly increased before decompensation of chronic mitral regurgitation associated with severe enlargement of the left atrium and ventricle in Cavalier King Charles Spaniels.

Analysis of Variance↗
PubMed1993

[The prognostic value of different patterns of change in the CD4 lymphocyte counts in 420 symptom-free HIV-1-infected persons].

The pattern of change over time of CD4-lymphocyte counts was investigated prospectively in 420 patients infected with HIV-1 (106 women, 314 men; mean age 34.9 [21-70] years) to assess its value in prognosticating progression to AIDS. Only those CD4-lymphocyte values were taken into account which had been measured in the asymptomatic stage of the HIV infection and before introduction of antiviral treatment. An average of 4.5 (range 3-10) measurements per person were available. Mean observation time was 2.4 years, the mean annual CD4-lymphocyte decrease was 48 cells/microliters. 121 patients (28.8%) had a fall in CD4-lymphocyte count which in the regression analysis significantly differed from zero. In this group there occurred 19 progressions to AIDS (15.7%), in contrast to only 20 (6.6%) in the 299 patients with a nonsignificant CD4 fall (P < 0.01). Multivariate analysis with the Cox regression indicated that the annual reduction in the CD4 count and the initial CD4 count were the only values of prognostic significance regarding progression to AIDS. There was no evidence that percentage and absolute CD4-lymphocyte counts had a different predictive value. When the initial CD4 count was high (> 900 cells/microliters), there was on average a steeper reduction in CD4-lymphocyte counts than when it was lower. This findings argues against a linear CD4 fall during the total period of observation. The annual CD4 fall, described with linear regression, is a prognostic criterion on its own for early recognition of those patients at a high risk of progression to AIDS while still in the asymptomatic stage of HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Functional capacity of transfused platelets estimated by the Thrombostat 4000/2.

Post-transfusion platelet increment is a useful test for the evaluation of transfusion efficacy. It does not, however, give information about the in vivo platelet function. We have evaluated the in vitro bleeding time (IVBT) using the Thrombostat 4000/2 with ADP as activating agent in 60 platelet transfusions given to 17 chemotherapy-induced severely thrombocytopenic patients. Determinations were performed before and after transfusion of platelet concentrates (PC) prepared from buffy coat. Both fresh and stored platelets resulted in significant reductions of the IVBT already 10 minutes after completed platelet transfusion. In the majority of patients there was a correspondence between IVBT and platelet increment. However, in 30% of the cases there was no improvement of the IVBT despite an increase of the platelet count. Fresh PCs were more effective than stored. The IVBT seems to represent a clear-cut improvement in the possibilities for evaluating and monitoring the effect of platelet transfusion.

Adolescent↗