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Biomedical subjects

L Wiklund

Publications and source records attributed to L Wiklund.

At least 163 records · Page 9Linked to original sources
PubMed1985

Thermal balance during transurethral resection of the prostate. A comparison of general anaesthesia and epidural analgesia.

Heat loss during anaesthesia and surgery is a common problem. In patients with restricted cardio-pulmonary reserves this may endanger the postoperative outcome. In order to compare thermal balance we studied 25 men undergoing transurethral resection of the prostate (TURP), using either general anaesthesia (G.A.) or epidural analgesia (E.A.). Oxygen uptake, catecholamines, peripheral and central temperatures were followed in the per- and postoperative period. Heat production and total body heat were calculated from oxygen uptake and temperature measurements, respectively. Transurethral resection of the prostate resulted in a peroperative heat loss which was not influenced by the anaesthetic technique used and averaged 370 kJ during the first hour of surgery. G.A. reduced heat production while this was uninfluenced by E.A. After termination of general anaesthesia, oxygen uptake and plasma catecholamines increased, while no such changes could be detected using epidural analgesia. The ability to increase mean body temperature by increasing heat production was negatively correlated to age.

Age Factors↗
PubMed1984

Differential labelling of afferents to thalamic centromedian-parafascicular nuclei with [3H]choline and D-[3H]aspartate: further evidence for transmitter specific retrograde labelling.

Microinjections of [3H]choline into the rat centromedian-parafascicular nuclei resulted in retrograde labelling of medium sized neurons in brainstem areas considered to comprise the origin of cholinergic innervation; the ipsilateral pedunculopontine tegmental, laterodorsal tegmental and parabrachial nuclei, and, bilaterally, in bulbar reticular formation. In contrast, D-[3H]aspartate labelled the origin of the corticothalamic input, which is believed to use glutamate and/or aspartate as transmitter. In addition, D-[3H]aspartate labelled smaller cells in mesencephalic and pontine periventricular gray, and parabrachial nuclei. It was concluded that retrograde labelling with [3H]choline and D-[3H]aspartate are selective phenomena with specificity for cholinergic and acidic amino acid connections, although occasional labelling of substantia nigra neurons with [3H]choline indicated that unspecific labelling may occur.

Afferent Pathways↗
PubMed1984

Selective retrograde labelling of the rat olivocerebellar climbing fiber system with D-[3H]aspartate.

Selective retrograde labelling of the olivocerebellar climbing fiber system with D-[3H]aspartate has been observed in the rat, and the results have implications for the identification of a transmitter candidate as well as the neuroanatomical understanding of these cerebellar afferents. Microinjections of D-[3H]aspartate (50 nl, ca 10-2 M) were made into various parts of cerebellar cortex. Survival times were 6, 12 or 24 h. Pronounced diffusion of the tracer resulted in large injection sites. Within the zone of injection, glial elements were labelled over background. Most granule cells exposed to the tracer were unlabelled; the small numbers demonstrating labelling were believed to have been injured by the micropipette penetration. Beneath injection sites, large numbers of well-labelled nerve fibers appeared in the white matter and could be followed through the brainstem to the contralateral inferior olive, where labelled perikarya were found. After the inferior olivary neurons had been effectively destroyed with 3-acetylpyridine, evidence of cerebellar afferent labelling with D-[3H]aspartate was missing. Retrograde labelling of the olivocerebellar system was also observed after superfusion of the vermis with D-[3H]aspartate at concentrations in the range of Km for high affinity uptake (10(-5) or 10(-4) M, for 2 h). Mossy fiber or monoaminergic afferents to the cerebellum were never labelled with D-[3H]aspartate. The distribution of labelled cells in the olivary subnuclei after injections in different cerebellar areas was in line with the olivocerebellar organization previously described in the cat. Moreover, it was demonstrated that fibers from the different subnuclei follow different routes through the brainstem towards the cerebellum. Labelling of climbing fiber collaterals in uninjected parts of cerebellum indicated that some of the retrogradely migrating D-[3H]aspartate was directed in anterograde direction at axonal branching points. Collaterals were demonstrated in all deep cerebellar and Deiters' nuclei, and the results of intranuclear injections suggested that virtually every olivary neuron sends collaterals to these nuclei. Intracortical collaterals were organized in sagittal zones. Midline injections into the anterior lobe and VI lobule labelled collaterals in several zones of the posterior lobe spinal area and uninjected parts of the anterior lobe vermis. Hemispheral injection into copula pyramidis labelled collaterals in two prominent bundles in the anterior lobe.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1984

Endocrine and metabolic responses after standardized moderate surgical trauma: influence of age and sex.

The endocrine and metabolic responses to elective cholecystectomy and the influence of age and sex on this stress response were investigated in 21 patients, eight men and 13 women. The patients were divided into two groups, older (n=10) and younger (n=11) than 55 years respectively. Arterial plasma concentrations of catecholamines, cortisol and free fatty acids as well as serum insulin and arterial blood concentrations of glucose, lactate, glycerol, alanine and 3-hydroxybutyrate were measured preoperatively and 2, 24, 48, 72 and 96 h after the start of surgery. Oxygen uptake and CO2 production were measured and respiratory quotient (RQ) was calculated. All hormones and metabolites except insulin and alanine were significantly elevated immediately after surgery. At 24 h plasma noradrenaline and blood glucose were still significantly increased. Serum insulin was increased at 24 and 48 h. Oxygen uptake and plasma cortisol were significantly elevated throughout the period studied and blood alanine was decreased from 2 to 72 h after surgery. The older group showed a significantly higher increase in noradrenaline and lactate, whereas women preoperatively as well as postoperatively had higher glycerol levels. At the end of the period studied women had higher FFA-levels. We conclude that cholecystectomy evokes a significant endocrine and metabolic response and that some of the variables studied are still significantly altered up to 4 days postoperatively. The influence of age and sex on this stress response is of minor importance.

Adult↗
PubMed1983

Failure to demonstrate retrograde labelling of cerebellar Purkinje cells after injection of [3H]GABA in Deiters' nucleus.

After microinjections of [3H]GABA into the dorsal part of the Deiters' nucleus no retrograde labelling could be observed in the cerebellar Purkinje cells projecting to this nucleus. Tentatively, this failure to demonstrate transmitter specific retrograde labelling is attributed to lack of high affinity uptake mechanisms in the GABAergic Purkinje axon terminals. These observations indicate a very important role of terminal uptake mechanisms in initiation of transmitter specific retrograde labelling. Anterograde axonal labelling was observed along several tracts originating in the injected area, but was not limited to connections with GABA as likely transmitter candidate.

Animals↗
PubMed1983

Red cell suspensions in SAGM medium. Further experience of in vivo survival of red cells, clinical usefulness and plasma-saving effects.

Red cells depleted of buffy coat and more than 90% of the plasma were suspended and stored in a medium composed of sodium chloride, adenine, glucose and mannitol (SAGM). The 24-hour posttransfusion survival of 51Cr-labeled red cells was 83.5 +/- 5.3% (n = 4) after storage for 35 days and 77.4 +/- 4.7% (n = 6) after 42 days. No abnormal in vivo hemolysis occurred as judged from posttransfusion haptoglobin consumption studies. No abnormal body temperature elevation was found at continuous pertransfusion recordings. The frequency of febrile or urticarial transfusion reactions was 0.19% as compared to 0.68% during a whole-blood transfusion period. Since a mean of 280 ml of plasma can be collected from each blood unit the plasma-saving effects of the system are considerable. Favorable large-scale clinical experience is reported.

Adenine↗
PubMed1983

Release of endogenous and accumulated exogenous amino acids from slices of normal and climbing fibre-deprived rat cerebellar slices.

Efflux of various amino acids from slices of rat cerebellar hemispheres was determined under resting or depolarizing conditions. It was increased under high K+(50 mM) as compared to low K+ (5 mM) conditions by 1258 pmol/mg protein for aspartate, 478 for gamma-aminobutyric acid (GABA), 44,693 for glutamate, and 615 for glycine. These were significantly higher than the corresponding values obtained under low-Ca2+ (0.1 mM), high-Mg2+ (12 mM) conditions, whereas for 11 other amino acids the K+-induced efflux was similar under normal and low-Ca2+ concentrations. The K+-induced efflux of exogenously accumulated L-[3H]aspartate, D-[3H]aspartate, and L-[3H]glutamate was higher by factors of 2, 5.8, and 6.3, respectively, under normal Ca2+ conditions, as compared with low-Ca2+, high-Mg2+ conditions. After climbing fibre degeneration induced by destruction of the inferior olive with 3-acetylpyridine, release of endogenous aspartate and exogenous L-[3H]glutamate and D-[3H]aspartate was significantly reduced, by 26%, 38%, and 27%, respectively. These results support the hypothesis that climbing fibres may use aspartate or a related compound as a neurotransmitter. In rat cerebellar tissue, L-[3H]glutamate and L-[3H]aspartate differ in several aspects: (1) L-[3H]glutamate uptake was 4 times higher than that of L-[3H]aspartate; (2) fractional rate constant of K+- evoked release of L-[3H]aspartate was 7% X 2.5 min-1, and of L-[3H]glutamate 36% X 2.5 min-1; and (3) specific activity of L-[3H]glutamate in the eluate collected during K+ stimulation was 3.5 times the value in the tissue, whereas for L-[3H]aspartate, specific activities in the eluate and tissue were similar.

Amino Acids↗
PubMed1982

Identification and distribution of neurons presumed to give rise to cerebellar climbing fibers in turtle. A retrograde axonal flow study using radioactive D-aspartate as a marker.

Radioactive D-aspartate and horseradish peroxidase were injected into the cerebellar cortex in turtle, Pseudemys scripta elegans. While neurons retrogradely labeled with horseradish peroxidase were found in various regions of the spinal cord and brainstem, labeled cells following aspartate injections were only observed in circumscribed regions of the caudal medulla. In rat it was recently reported that climbing fibers, but no other cerebellar afferents, were retrogradely labeled with D-aspartate (Wiklund et al.12). It is suggested that the aspartate-positive neurons in turtle also give rise to climbing fibers.

Afferent Pathways↗
PubMed1982

Aspartate: possible neurotransmitter in cerebellar climbing fibers.

Autoradiography demonstrated prominent retrograde labeling of olivocerebellar climbing fiber neurons after injection of tritiated D-aspartate into the rat cerebellar cortex or deep nuclei. Mossy fiber systems originating in the brainstem and spinal cord remained unlabeled. Potassium ion-induced depolarization of cerebellar slices resulted in calcium ion-dependent release of endogenous L-aspartate, L-glutamate, gamma-aminobutyric acid, and glycine. A 26 percent decrease in aspartate release was observed after 3-acetylpyridine-induced destruction of the inferior olive, supporting the hypothesis that aspartate is a neurotransmitter in climbing fibers.

Amino Acids↗
PubMed1982

Regional blockade versus analgesic therapy.

Like other investigators, we have found that the postoperative period is characterized by high energy expenditure, pain, high plasma catecholamines and decreased arterial oxygen tension, and also glycogenolysis, lipolysis, proteolysis and a low turn-over rate of glucose. Regional anaesthesia has often been supposed to counteract some of these phenomena without causing ventilatory depression. During the past few years a number of studies have been carried out in our department with the aim of elucidating possible differences between the effects of systemic analgesics and different regional anaesthetic blockades. Thus, we have found that both systemic analgesics and regional anaesthesia decrease the total postoperative energy expenditure. Adequately administered regional anaesthesia and systemic analgesic therapy both relieve postoperative pain, the former without interfering with normal ventilatory function. In addition, regional anaesthetic techniques cause less mental confusion, fewer bowel problems and possibly less postoperative lung complications. Moreover, high spinal blockades seem to be the only means of reducing the post-traumatic metabolic stress reaction.

Analgesics↗
PubMed1981

Monoamine cell distribution in the cat brain stem. A fluorescence histochemical study with quantification of indolaminergic and locus coeruleus cell groups.

The distribution of monoaminergic cell bodies in the brainstem of the cat has been examined with Falck-Hillarp fluorescence histochemical technique. Quantitative determinations indicate that the cat brainstem contains about 60,300 indolaminergic (IA) cells. The majority of these (about 46,700, or 77.5%) are located within raphe nuclei. The largest number is contained within nucleus raphe dorsalis (RD), accounting for around 24,300 IA cells, while raphe pallidus (RP) holds about 8,000 raphe centralis superior (RCS) 7,400, raphe magnus (RM) 2,400, raphe obscurus (RO) 2,300, linearis intermedius (LI) 2,100, and the raphe pontis (RPo) only some 280 IA cells. The IA cells represent, however, only part of the neuronal population of raphe nuclei, which, in addition, hold varying numbers of other medium-sized and small-sized neurons. Thus, quantification in Nissl-stained material indicate that the IA cells make up about 70% of the medium-sized cells in RD, 50% in RP, 35% in RCS and RO, 25% in LI, 15% in RM, and only 10% in RPo. The substantial numbers of small-sized perikarya observed in all raphe nuclei may represent interneurons. Significant numbers of IA cells were consistently located outside the raphe nuclei at all brainstem levels. In all, these amounted to approximately 13,600, or 22.5% of the total number of IA cells. Thus, IA cells occurred in the myelinated bundles, and sometimes in reticular formation, bordering the raphe nuclei; in the ventral brainstem forming a lateral extension from the ventral raphe (RP, RM, RPo, RCS, and LI) to the position of the rubrospinal bundle; in the periventricular gray and subjacent tegmentum of dorsal pons and caudal mesencephalon; in the locus coeruleus (LC) complex; around the motor trigeminal nucleus; caudal to the red nucleus; and in the interpeduncular and interfascicular nuclei. The wide distribution of IA cells leads to a considerable mixing with catecholaminergic (CA) cell groups. Our observations on CA cell distribution are essentially in accordance with previous reports. Quantifications indicate that the LC complex contains about 9,150 CA cells, unilaterally. A previously unnoticed group of scattered CA cells was found in relation to the vestibular nuclei and extending dorsally toward the deep cerebellar nuclei.

Animals↗
PubMed1981

Scattered catecholaminergic cells in the dorsolateral tegmentum caudal to locus coeruleus in cat.

In the cat brain stem, extending from the caudal locus coeruleus, scattered catecholaminergic (CA) cells are distributed over a large area. This includes a periventricular region dorsolateral to the fourth ventricle corresponding to the A4 group, the white matter separating vestibular and intracerebellar nuclei, and lateral to the vestibular complex in relation to the restiform body. In all, these CA cells were found to number 122 +/- 54 (mean +/- S.D.), unilaterally.

Animals↗
PubMed1981

Splanchnic turn-over of some energy metabolites and acid-base balance during intravenous infusion of lidocaine, bupivacaine or etidocaine.

The splanchnic turn-over of energy metabolites in circulating blood has been studied in four groups of young, healthy volunteers, receiving intravenous infusions of physiological saline (n = 5), lidocaine 4 mg/min (n = 7), bupivacaine 2 mg/min (n = 7) and etidocaine 2 mg/min (n = 8). The results showed that the local anaesthetic agents increased the splanchnic blood flow and oxygen consumption, the uptake of glycerol and lactate, and the release of 3-hydroxybutyrate. These effects are adrenaline-like but cannot be explained by one single mechanism involving increased activity of the sympathetic nervous system. Only a minor part of the increased oxygen uptake could be attributed to the energy cost of drug metabolism.

3-Hydroxybutyric Acid↗