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Biomedical subjects

G Johansson

Publications and source records attributed to G Johansson.

At least 307 records · Page 17Linked to original sources
PubMed1984

Pre-operative alcohol infusion. The need for analgesic supplementation in chronic alcoholics.

The influence of pre-operative alcohol infusion on the requirement for analgesic supplementation with fentanyl in chronic alcoholic patients was studied. The chronic alcoholic was defined as a person having a regular daily alcohol consumption of over 70 g pure alcohol for at least 3 years. The mean annual consumption in the patients studied was 52 litres pure alcohol. A positive correlation between requirement for fentanyl and alcohol consumption was found. The amount of fentanyl required to achieve satisfactory analgesia (the 'saturation dose') was significantly higher (61%) in alcoholic than in non-alcoholic patients. Once stable anaesthesia was achieved the maintenance dose was the same in alcoholic and non-alcoholic patients. Pre-operative infusion of alcohol significantly reduced the amount of fentanyl required to achieve anaesthesia in both alcoholic and non-alcoholic patients (by 25% and 29% respectively). Furthermore it prevented some of the catecholamine mediated effects, such as increase in blood pressure, heart rate and blood glucose.

Alcoholism↗
PubMed1984

Effect of phenoxybenzamine on myocardial cell necroses and blood levels of catecholamines in pigs subjected to stress.

The degree of myocardial cell necroses after stress was investigated in 6 pigs, weighing 70 to 90 kg. The stress was induced by a myorelaxant, succinylcholine, for about 12 min. The alpha-adrenoceptor blocking agent phenoxybenzamine (PBZ) was given orally 3 times a day in a total dose of 50 to 60 mg per day for 6 to 7 days before the stress. The plasma levels of noradrenaline and adrenaline were assayed in blood samples drawn before, during, and immediately after the period of stress. Heart cell necroses were found in all the cases. The activity of the sympathetic-adrenomedullary system, indicated by the plasma levels of catecholamines, was intense during the stress. When the present results were compared with those of earlier studies the degree of heart cell necroses was significantly smaller after PBZ in control pigs but significantly higher than after the beta-adrenoceptor blocking agent propranolol given for about a week. PBZ exerts a number of different actions, as briefly discussed, some of them appearing to be harmful for the heart during stress while others appear to be protective for the heart.

Animals↗
PubMed1984

The effect of lighting conditions on plasma levels of gonadotropins in castrated male rats.

Plasma levels of LH and FSH were measured in castrated male rats kept in a 12/12 h light/dark cycle (control lighting), continuous light or continuous darkness. In Experiment I, the animals were kept in the three illumination conditions for 5 weeks. They were then decapitated for blood collection. In Experiment II, the blood samples were collected daily via permanently implanted aortic cannulae after 7 days of adaptation to the experimental lighting condition. In both experiments, the plasma levels of LH and FSH were higher in the rats kept in continuous light than in those kept in control conditions. After exposure to darkness for 5 weeks, the gonadotropin levels did not differ from the control values. In Experiment II, the levels of FSH were lower in darkness than in the control lighting, but the levels of LH did not change.

Animals↗
PubMed1984

The effect of blood sampling on plasma levels of LH and FSH in male rats.

Plasma levels of LH and FSH in male rats were compared in blood samples collected by decapitation or through permanently implanted aortic cannulae. The hormone levels were higher in the samples taken by decapitation. After cannulation, the gonadotropin levels remained unchanged when sampling occurred only once a day and each rat was bled 1-3 times over a period of 7 days (sample volume 2.3 ml). The hematocrits of these rats decreased from 42% to 34% after two samplings. In another experiment the LH and FSH levels increased when seven samples had been taken during 24 h. In this experiment the blood cells were reinfused into the circulation, and as a result after 5 samples the hematocrit decreased only from 45% to 40%. A drop in food consumption was observed after cannulation. It is suggested that the increase in gonadotropin levels may be due to the acute stress caused by handling during and before decapitation or decrease in gonadotropin levels may be due to the chronic stress caused by the implanted cannula. The frequent bleedings and cell infusions into the cannulated rats may stimulate the secretion of gonadotropins, opposing the effect of chronic stress.

Animals↗
PubMed1984

Diazepam, alpha and beta neurotransmission modifying drugs and contrast media mortality in mice.

Drugs influencing neurotransmission (alpha 1,2, beta 1,2 agonists, antagonists and diazepam) were given intraperitoneally to test their effects on the mortality of intravenous meglumine diatrizoate. Pretreatment with diazepam in two doses (0.14 and 0.56 mg/kg), alpha 1,2 agonist, beta 1 agonist and beta 1 antagonist affected LD50 so that 5 to 9 per cent more contrast medium could be administered to cause the same mortality as the contrast medium alone. Still higher (19-24%) doses could be used after an alpha 1,2 or alpha 1 antagonist. The beta 1,2 antagonist employed in the test decreased the contrast dosage by 13 per cent, causing the LD50.

Animals↗
PubMed1984

The urethral pressure profile during flow. An experimental study.

As part of a project aimed at developing a method for accurate evaluation of the position and significance of infravesical outflow obstructions, a technique for recording urethral pressure profiles during flow in male patients was tested in a rigid bladder-urethral model. The catheter which proved to give the most accurate recording of the static pressure in the urethral model had a measuring eye about 250 mm from the tip. With this arrangement, the tip of the catheter did not leave the bladder until the measuring eye had passed the whole length of the urethra and the effective diameter of the urethra and the flow did not change during the recording. The pressure profiles for the different urethral models closely resembled the theoretically calculated curves. Furthermore, the constant recording conditions made it possible to compensate for the influence of the measuring catheter and to calculate the "true" diameter as well as the "true" resistance in different segments of the models.

Catheters, Indwelling↗
PubMed1984

The micturitional urethral pressure profile.

The micturitional urethral pressure profile (MUPP) was recorded using a measuring catheter with two eyes, 250 mm apart, one for recording the bladder pressure, the other for the urethral pressure during continuous withdrawal during micturition. Fifteen normal male subjects and 48 male patients with infravesical obstruction were studied. By means of the MUPP, it was possible to determine whether the patient had an obstruction or not, to differentiate between various kinds of obstructions and to localise the obstruction in the urethra. Provided infravesical obstructions can be considered "near rigid" segments, the degree of obstruction can be calculated and expressed in terms of a diameter and an approximate resistance. The diameter and resistance values should, however, not be considered alone but be regarded as complementary to the pressure profile.

Adult↗
PubMed1984

A prospective study of the clinical significance of the treatment of gallstones with chenodeoxycholic acid.

Three hundred and forty-two consecutive patients admitted for cholecystectomy were taken into consideration for medical treatment with CDC. Twenty-two patients were eligible for such treatment. The remainder were excluded for the following reasons: 1, emergency operation in 20; 2, nonfunctioning gallbladder in 136; 3, large gallstones in 100; 4, radiopaque calculus in 30, and 5, hepatic disease in seven. Other reasons for surgical treatment were fertile women without adequate contraception, severe biliary tract symptoms, indication for exploratory laparotomy and insufficiency in handling the medication. Twelve patients were treated with CDC. One patient had complete dissolution of the gallstone. It is concluded that the introduction of medical treatment with CDC did not reduce the number of cholecystectomies at a surgical clinic.

Adult↗
PubMed1983

Recovery of proteins on a milligram scale from polyacrylamide electrophoresis gels, exemplified by purification of a retinol-binding protein.

An apparatus suitable for the recovery of proteins from polyacrylamide gels on a milligram scale by displacement electrophoresis (isotachophoresis) is described along with a buffer system that is suitable for this purpose with most proteins. The technique is illustrated by the recovery of a protein from a 15% polyacrylamide gel. The recovery was almost quantitative and the eluted protein showed little contamination upon quantitative amino acid analysis and automatic Edman degradation.

Amino Acid Sequence↗
PubMed1983

Affinity partitioning of phosphofructokinase from baker's yeast using polymer-bound Cibacron blue F3G-A.

1. Phosphofructokinase from baker's yeast is partitioned between the phases of an aqueous two-phase system, containing dextran (Mr = 500000) and poly(ethyleneglycol) (Mr = 6000), in favour of the dextran-rich phase. By covalent binding of the dye Cibacron blue F3G-A to poly(ethyleneglycol) the enzyme can be extracted to the phase rich in this polymer, i.e. affinity partitioning. 2. The affinity partitioning effect, measured as the logarithmic increase of the partition coefficient by introducing polymer-bound Cibacron blue, depends on several factors. The influence of dye-polymer concentration, polymer concentration, polymer molecular weight, kind of salt and salt concentration, pH and temperature has been studied. 3. The effect of ATP, ADP, AMP, ITP, fructose 1,6-bis-phosphate and fructose 6-phosphate show large differences in the binding strength of these substances to the Cibacron blue binding sites. AMP cannot compete with Cibacron blue while ATP is strongly competing. 4. The use of affinity partitioning for enzyme isolation and determination of ligand binding is discussed, as well as possible mechanisms concerning this type of liquid/liquid extraction.

Adenosine Triphosphate↗
PubMed1983

Ambulatory diagnostic evaluation of 389 recurrent renal stone formers. A proposal for clinical classification and investigation.

389 consecutive renal stone formers (275 males, 114 females) were investigated in an out-patient stone clinic. Renal tubular acidosis (RTA) was found in 83 patients (22%). Proximal RTA was twice as common as the distal tubular type. The acidification defects were exclusively of the incomplete form with normal basal blood acidbase status. Main diagnoses besides RTA were primary hyperparathyroidism (3.5%), medullary sponge kidney (3.5%), infection induced stones (3%), urate stones (2%), intestinal disorder (1.5%) and cystinuria (0.5%). The metabolic evaluation was mainly based on 24 h urine sampling on a free diet. In 248 patients (64%) no distinct abnormality was considered to be primarily responsible for stone formation. Clinical and biochemical analysis of these so-called idiopathic stone formers disclosed a male preponderance (80%) and, compared to a non-stone-forming control group, a higher urinary calcium excretion, yet with a considerable overlap between the two groups. Hyperuricosuria and hyperoxaluria were rare findings. The conclusion of the study is given as a proposal for clinical classification and ambulatory investigation of renal stone formers.

Adolescent↗
PubMed1983

Uricemia and urinary acidification in renal calcium stone disease.

Serum urate concentrations were determined in 487 consecutive patients with stone disease and in 89 controls. Male controls had higher concentrations than female controls but men and women with stones had lower concentrations than controls. Renal acidification defects, incomplete and complete forms, were found in 25 per cent of the patients with stones, with the highest frequency in patients with hyperuricemia. Patients with proximal renal acidification defects had a higher serum urate concentration than patients with normal acidification of the urine. The urinary excretion of urate was higher in hyperuricemic than in normouricemic patients but lower in patients with hyperuricemia and renal acidification defects than in those with hyperuricemia and normal acidification of the urine. This finding indicates that underexcretion rather than overproduction contributes to the higher serum urate concentration in patients with renal acidification defects. Stone patients with high serum urate levels, especially in combination with renal acidification defects, had more severe stone disease and underwent more operations than other patients with stones. Thus, hyperuricemia does not appear to be a common feature in patients with calcium stone disease, although it is associated with formation of large stones for unknown reasons.

Adult↗
PubMed1983

Lipoteichoic acid is the major cell wall component responsible for surface hydrophobicity of group A streptococci.

The contribution of lipoteichoic acid (LTA) to the hydrophobic surface properties of group A streptococci was investigated in aqueous dextran-polyethylene glycol two-phase systems. Enzymatic digestions were performed to characterize the hydrophobic surface structure. The results obtained indicated that LTA is a major factor responsible for the hydrophobic character of the cell surface of group A streptococci. This was further supported by the similarity of partition in polymer two-phase systems between whole group A streptococci and tritiated LTA extracted from a group A streptococcal strain. Surface LTA was also determined on intact organisms by a new method measuring the adsorption of antibodies to LTA to the bacterial surface. A correlation was found between the content of surface LTA and the hydrophobicity of the group A streptococci. We conclude that surface-associated LTA is the major factor determining surface hydrophobicity of group A streptococci.

Antigens, Bacterial↗
PubMed1983

Hormonal effects of beta-receptor blockade during exercise.

The effects of two different beta-receptor blocking agents, beta 1-selective metoprolol (150 mg/day) and non-selective propranolol (120 mg/day), on hormonal responses to physical exercise (30 min bicycle ergometer test) were compared with placebo within a double-blind, cross-over design in 7 healthy male volunteers. Plasma prolactin levels decreased from the initial values during and after exercise during treatments with placebo and beta-receptor blocking agents, but they were constantly higher with the two beta-blocking agents than with placebo. Exercise did not affect plasma testosterone levels, but during propranolol they remained higher than during placebo and metoprolol. The plasma LH and FSH levels were not affected by exercise, nor were they significantly modified by beta-blockade. The results of this study as well as those of previous studies indicate that beta-receptor blocking agents interfere with physiological endocrine functions and that the non-selective agents may have more distinct effects in this respect.

Adrenergic beta-Antagonists↗
PubMed1983

Changes in plasma zinc and urinary excretion of zinc after operation with extracorporeal circulation.

Sixteen adults undergoing cardiac surgery were studied with respect to postoperative levels of zinc in plasma and urinary excretion of zinc. The preoperative plasma concentrations of zinc were normal. On the first postoperative day the mean for the series had fallen from 15 to 7.2 mumol/l. A gradual rise followed, and on the fifth day all patients had plasma zinc above the lower limit of normal range. The urinary excretion of zinc was significantly increased on the first, second and fifth days after surgery. The mean total of zinc in the urine during five days was 67 mumol. The short-term fall in plasma zinc level had no discernible effect on wound healing. It was therefore apparently harmless and did not indicate a need for zinc supplementation.

Aged↗
PubMed1982

Ischemic pain nonsegmentally produces a predominant reduction of pain and thermal sensitivity in man: a selective role for endogenous opioids.

Ischemic pain was produced by a blood pressure cuff placed to the arm of healthy human subjects for 15 min which produced a mean pain score of 59% (visual analogue scale). Ischemia induced a significant dental pain threshold elevation (mean 67%) and 2 mg of naloxone did not reduce it. Thermal sensitivity of the upper lip had a tendency to reduction during ischemia and 2 mg of naloxone reduced this effect. Tactile thresholds in the forehead or in the contralateral arm were not markedly elevated. Neither ACTH nor prolactin level in the plasma was related to the dental pain threshold elevation during ischemia. The findings of the present study suggest that ischemic pain nonsegmentally produces a predominant inhibition of responses to thin afferents. Endogenous opioids may markedly contribute to the reduction of thermal sensitivity induced by ischemia, but their contribution to dental pain threshold elevations seems to be less important. Stress or other adenohypophyseal mechanisms involving the release of ACTH or prolactin do not explain the effects of ischemia found in the present study.

Adrenocorticotropic Hormone↗
PubMed1982

Hydrophobic surface properties of myosin in solution as studied by partition in aqueous two-phase systems: effects of ionic strength, pH and temperature.

Affinity partitioning in dextran-polyethylene glycol-water biphasic systems has demonstrated that myosin has hydrophobic surface properties. In 0.5 M KCl at pH 7.5 myosin is transferred at increasing amounts to the polyethylene glycol-rich upper phase when an increasing proportion of that polymer in the system is replaced by its ester with lauric, myristic or palmitic acid. This shows that on its surface myosin has binding sites with affinity for long chain fatty acyl groups. Partition studies on the ionic strength range of 0.2-0.6 M KCl at pH 7.5 at 4 degrees C and 20 degrees C, respectively, in systems containing polyethylene glycol-palmitate showed that the affinity of myosin for the palmitate group becomes greater with (1) an increase in ionic strength, and (2) an increase in temperature at constant ionic strength. The affinity of myosin for the palmitate group also increases with a decrease in the pH in the range of 5.6-8.5. The increase in the affinity of myosin for the palmitate group parallels the increase in the tendency of myosin to self-interact and yield filaments.

Animals↗