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Biomedical subjects

K Olsson

Publications and source records attributed to K Olsson.

At least 109 records · Page 6Linked to original sources
PubMed1984

Oral or nasal intubation after cardiac surgery? A comparison of effects on heart rate, blood pressure and sedation requirements.

The aim of this study was to observe the effects of the position of the tracheal tube on cardiac performance or sedation requirements after cardiac surgery. There were no significant differences in heart rate, systolic blood pressure, or rate-pressure product during the first 16 hours postoperatively when 41 orally intubated patients were compared with 32 patients who were reintubated nasally. The two groups received similar amounts of sedative drugs postoperatively. During attempted nasal intubation, bleeding developed in four patients, and in three of these and four others the tube could not be passed. Failed nasal intubation gave rise to nasal discomfort in three of seven patients. Orally intubated patients complained more often of sore throat after extubation, whereas those who had been nasally intubated complained of discomfort in the nose and throat. We conclude that nasal re-intubation carries no advantage over oral intubation for ventilation after cardiac surgery.

Blood Pressure↗
PubMed1984

Effects of captopril on arterial blood pressure, plasma renin activity and vasopressin concentration in sodium-repleted and sodium-deficient goats. A serial study during pregnancy, lactation and anestrus.

The effects of captopril (intravenous loading dose of 20 mg, 1 h later followed by 10 mg infused during the next h) on arterial blood pressure and plasma renin activity were followed in 4 goats during the last months of pregnancy, during lactation and during anestrus. Experiments were made both when the animals were sodium-repleted and sodium-deficient. Furosemide and dietary restriction were used to deprive the animals of sodium. In sodium-replete animals, captopril caused a more pronounced fall in mean arterial blood pressure and a larger increase in plasma renin activity (PRA) when the animals were pregnant than when they were lactating or in anestrus. During sodium-deficient conditions the response was similar as during sodium repletion in pregnant goats. In anestral goats, PRA rose in response to captopril, but the blood pressure fall was similar as when the goats were sodium-replete. In lactating sodium-deficient goats, captopril caused a marked fall in mean arterial blood pressure concomitant with a 2-3 times higher rise in PRA than during corresponding sodium-repletion experiments. The respiratory rate was elevated in pregnant animals and increased further during captopril. The plasma vasopressin concentration did not change during captopril-induced hypotension. If the blood pressure fell greater than or equal to 10 mmHg the animals became very quiet and occasionally they fell asleep. All goats delivered healthy kids. The fact that the blood pressure fall was marked and consistent in all animals during pregnancy, but less and more variable during anestrus indicates that the activity of the renin-angiotensin system is of greater importance for blood pressure maintenance during pregnancy than during anestrus.(ABSTRACT TRUNCATED AT 250 WORDS)

Anestrus↗
PubMed1984

Letter legibility and the construction of a new visual acuity chart.

The ability to identify letters of different size remains, in relation to the allowed effort, the most informative measure of visual capacity. Numerous letter charts have been produced with varying design, size, and size progression of the letters. Attempts to 'standardize' letter testing have been fruitless. In Sweden, the most commonly used letter charts show deficiencies in letter selection, size, and progression. In the present study, letter legibility was studied. 10 letters of average legibility were selected and a new chart constructed using these letters in sizes corresponding to acuities from 0.1 to 2.0. A geometric size progression was found optimal (factor 1.26).

Humans↗
PubMed1983

Ripening of the human uterine cervix related to changes in collagen, glycosaminoglycans, and collagenolytic activity.

Connective tissue in biopsy specimens taken from the lower part of the uterine cervix in 40 pregnant women at various gestational ages was compared to that in similar biopsy specimens from 15 nonpregnant women. The concentrations of collagen, sulfated glycosaminoglycans, and hyaluronic acid decreased during pregnancy. At the gestational age of 10 weeks, the collagen concentration was 70%, and at term 30%, of that in the nonpregnant cervix. After delivery, no further decrease was observed. The extractability of collagen increased during pregnancy, as well as during labor. Also, the water concentration increased. An increase in the collagenolytic activity was observed with advancing gestational age. The 2,4-dinitrophenyl-Pro-Gln-Gly-Ile-Ala-Gly-Gin-D-Arg hydrolytic activity (collagenase) and the concentration of leukocyte elastase increased gradually by a factor of 10. The physiologic importance of the collagen was also demonstrated, since the cervical dilatation time during spontaneous labor was long in women with high concentrations of collagen and short in women with low concentrations of collagen.

Adult↗
PubMed1983

Central control of vasopressin release and thirst.

The effects of changes in the composition and/or the volume of the extracellular fluid on central receptors involved in the regulation of water balance are discussed. A review of results obtained in adults is given, followed by a discussion of possible roles for vasopressin during the neonatal period.

Angiotensin II↗
PubMed1982

A serial study of fluid balance during pregnancy, lactation and anestrus in goats.

Water and salt balance was studied in the same goats during pregnancy, lactation and anestrus. All goats increased their water intake during the course of pregnancy, but individual differences were large. In general, twin pregnant (TP) goats drank more water than single pregnant (SP) animals (3.4 +/- 0.4; N = 11 as compared to 2.5 +/- 0.3 litres/day; N = 5) during the last weeks of pregnancy. During lactation the high water intake TP goats persisted and the SP animals increased their intake to the same level as the TP goats. The water intake was reduced to about 2 1/day in both categories of animals during anestrus. Urine volume largely followed the changes in water intake in the individual animal. A continuous decrease in urine osmolality during the course of pregnancy occurred, but during lactation urine osmolality increased towards anestrus levels. TP goats generally retained more sodium than SP animals during pregnancy and during anestrus, whereas the figures were similar during lactation. Plasma Na, K and osmolality remained unchanged during pregnancy, lactation and anestrus, but a large fall in total plasma proteins and a moderate fall in hematocrit were observed during the course of pregnancy. Glomerular filtration rate of TP goats was elevated by about 35% during the 4th month of pregnancy, but did not differ from anestrus levels during the 3rd and 5th month or during lactation. Effective renal plasma flow was highest during the 3rd pregnancy month and then fell to reach lactation and anestrus levels during the 4th month of pregnancy. A few hours before parturition the animals became markedly dehydrated as shown by sudden increases in plasma Na, K, osmolality, total proteins and hematocrit. This water deficit was replenished within 26 h post-partum.

Anestrus↗
PubMed1982

Effects of water deprivation and hyperhydration in pregnant and lactating goats.

The response to 30 h water deprivation was studied in 7 goats during the last month of pregnancy and during lactation with anestrus as the control period. Plasma osmolality and plasma Na concentration increased by about 4% in pregnant and lactating goats and by about 2% in anestral goats. Plasma AVP concentration rose by about 7 pg/ml in pregnant and lactating goats, but only by about 3 pg/ml during anestrus. PRA was elevated in pregnant animals, but dehydration caused only a minor further rise. Total plasma protein concentration was low in pregnant goats and did not increase during water deprivation, but it did so in lactating animals. Neither the hematocrit nor the plasma K concentration changed in response to dehydration. GFR fell by about 24% in pregnant goats and by 22% in lactating animals, but remained unchanged during anestrus. ERPF fell by 20% in lactating animals, but no consistent effect of the dehydration was seen during pregnancy and anestrus. Urine flow decreased by about 75% during pregnancy, 55% during lactation and 65% during anestrus with the highest urine osmolality observed during anestrus. Milk production was only slightly reduced, but the milk osmolality increased in parallel with that of the blood plasma. When allowed to drink at the end of the water deprivation period, pregnant goats immediately drank 2.5 +/- 0.5 litres, lactating goats 3.3 +/- 0.9 litres and anestral goats 1.1 +/- 0.3 litres. When hyperhydrated, pregnant goats excreted the excessive water more readily and showed less response to exogenous AVP than lactating and anestral animals. In conclusion, pregnant and lactating goats are obviously more susceptible to a shortage of water supply than anestral animals but can easily excrete an excess of water.

Animals↗
PubMed1982

Effects of hemorrhage on vasopressin secretion and arterial blood pressure during experimental diabetes insipidus in goats.

The effect of hypotensive hemorrhage on plasma vasopressin (AVP) concentration and carotid blood pressure before and after induction of experimental diabetes insipidus (DI) was studied in the conscious goat. Bleeding to the point of blood pressure fall (blood loss 15-25% of the estimated blood volume) caused an immediate, approximately hundred fold, increase in the plasma AVP concentration in the normal animal. Hemorrhage to the same extent during DI did not affect the plasma AVP levels. A rather transient hypotensive response to bleeding was seen before disruption of the pituitary stalk, but during DI the recovery of the hemorrhage-induced hypotension was less effective. However, the normalization of the blood pressure after bleeding was slightly more efficient during the permanent than during the temporary phase of DI. It is concluded that an intact hypothalamo-neurohypophysial connection is necessary for the massive release of AVP normally seen in response to hypotensive hemorrhage. It is also confirmed that the lack of this hormonal response to bleeding is accompanied by an increased susceptibility to the hypotensive effect of hemorrhage.

Animals↗
PubMed1982

Effect of stress on myocardial cells and blood levels of catecholamines in normal and amygdalectomized pigs.

The effects of restraint stress on heart activity, blood catecholamines and the development of myocardial necrosis were studied in five unoperated and five unsuccessfully amygdalectomized (sham-operated) pigs and compared with six bilaterally amygdalectomized pigs. In the sham-operated and the nonoperated animals, restraint stress often provoked intense tachycardia, as well as considerable elevations of blood catecholamines, particularly noradrenaline, associated with more or less widespread foci of myocardial necrosis. In contrast, the same restraint produced only minor heart rate increase in the six completely amygdalectomized animals; their blood noradrenaline levels were significantly lower and no myocardial necrosis could be detected, either macro- or microscopically. The results indicate that the amygdaloid part of the limbic system and the sympathoadrenal system are of importance in the induction of myocardial necrosis often noted in pigs when exposed to situations of severe mental stress.

Amygdala↗
PubMed1980

Ring chromosome 14 in a mentally retarded girl.

A case of ring chromosome 14 in a 12-year-old girl, showing mental retardation, epilepsy and minor somatic abnormalities, is described and compared with five previously reported cases with the same chromosome aberration.

Abnormalities, Multiple↗