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Biomedical subjects

B Lindberg

Publications and source records attributed to B Lindberg.

At least 91 records · Page 5Linked to original sources
PubMed1988

Effects of macromolecular adjuvants on the duration of prilocaine. Experimental studies on the effect of variations of viscosity and sodium content and of inclusion of adrenaline.

Sodium hyaluronate (HA) and dextran (Dx) of different molecular weights and concentrations were used as adjuvants to prilocaine for studies of the duration of infraorbital nerve block in the rat (IONB) and spinal anaesthesia in the mouse (SA). A positive relation was found between duration of block on the one hand and the concentration as well as the molecular weight of the adjuvant on the other. A direct relation was found between the duration of block and the viscosity of the anaesthetic solution. Low-sodium-content solutions of plain prilocaine caused a markedly prolonged duration of the most profound degrees of IONB as compared to medium- or high-sodium-content solutions, while no differences between the solutions were found for the weakest intensity of IONB studied or for SA. Solutions of low-sodium-content containing prilocaine and HA were associated with significant prolongations of IONB and SA as compared to corresponding solutions of medium- or high-sodium content. Inclusion of adrenaline, 5 micrograms/ml, in solutions containing prilocaine and Dx significantly prolonged the duration of the most profound degrees of IONB and of SA. By contrast, the inclusion of adrenaline in solutions containing prilocaine and HA did not prolong the duration of IONB or SA. It is concluded that modulations of the viscosity of local anaesthetic solutions by the addition of macromolecular compounds strongly affect the duration of peripheral and central nerve blocks in experimental animals. A further prolongation is accomplished by reducing the sodium content of the solutions and, in the case of Dx-containing solutions, by inclusion of adrenaline in the anaesthetic solution. The possible mechanisms of these actions are discussed.

Adjuvants, Anesthesia↗
PubMed1988

Cerebrospinal fluid activity of dynorphin-converting enzyme at term pregnancy.

Cerebrospinal fluid activity of a dynorphin-converting enzyme transforming prodynorphin-derived peptides to [Leu]enkephalin-Arg6 was measured in 12 women at term pregnancy before cesarean section and in eight nonpregnant, nonpuerperal controls. In pregnant women, the dynorphin-converting enzyme activity was significantly lower (mean +/- SD 6.8 +/- 3.8 U/L) than in nonpregnant controls (11.7 +/- 2.6 U/L; P less than .01). Furthermore, prodynorphin-derived [Leu]enkephalin-Arg6-containing polypeptides were significantly increased in samples from pregnant women (P less than .05). This indicates that a reduced activity of opioid peptide-degrading enzymes might contribute to an increased resistance to pain at term pregnancy.

Cesarean Section↗
PubMed1987

Structural studies of the Escherichia coli O78 O-antigen polysaccharide.

The structure of the O-antigen polysaccharide from Escherichia coli O78 has been investigated; methylation analysis, partial solvolysis with liquid hydrogen fluoride, and 2D-n.m.r. spectroscopy were the principal methods used. It is concluded that the polysaccharide is composed of tetrasaccharide repeating-units having the following structure.----3)-beta-D-GlcpNAc-(1----4)-beta-D-GlcpNAc- (1----4)-beta-D-Manp-(1----4)-alpha-D-Manp-(1----

Antigens, Bacterial↗
PubMed1987

Structural studies of the capsular polysaccharide from Streptococcus pneumoniae types 15B and 15C.

The structures of the capsular polysaccharides (S-15B and S-15C) from Streptococcus pneumoniae types 15B and 15C have been investigated by using n.m.r. spectroscopy, methylation analysis, and various specific degradations. It is concluded that the polysaccharides are composed of pentasaccharide repeating-units having the following structure: (Formula: see text). In this structure, R is H (80%) or CH2CH2N+Me3 (20%). S-15B further contains O-acetyl groups, approximately 0.7 per repeating unit, which have not been located. The capsular polysaccharides S-15F and S-15A, which have been studied previously, are also composed of pentasaccharide repeating-units, containing the same sequence of sugars, but in a linear arrangement.

Carbohydrate Conformation↗
PubMed1987

Structural studies of the O-specific side-chains of the Escherichia coli O2 lipopolysaccharide.

The structure of the O-specific side-chains of the Escherichia coli O2 lipopolysaccharide has been investigated, different 1H- and 13C-n.m.r. techniques being the main methods used. It is concluded that they are composed of pentasaccharide repeating-units having the following structure, in which D-Fuc3NAc is 3-acetamido-3,6-dideoxy-D-galactose. ----4)-beta-D-GlcpNAc-(1----3)-alpha-L-Rhap-(1----2)-alpha-L-Rh ap-(1----3)-beta-L-Rhap-(1----2 increases 1 alpha-D-Fucp3NAc.

Carbohydrate Conformation↗
PubMed1987

Acupuncture before delivery: effect on labor.

Acupuncture treatment in the final weeks of pregnancy has been claimed to shorten the duration of labor in primiparous women. In the present study, the length of the various phases of labor was calculated for 56 primiparous women who were repeatedly treated with manual acupuncture during the month prior to parturition. In vaginally delivering women, the average lengths of the latent and active phase and the second stage of labor were 4.1, 3.4 and 1.4 h, respectively. In a nontreated control group of 112 primiparous women, the corresponding durations were 4.4, 3.5 and 1.1 h. Acupuncture treatment before delivery did not shorten the delivery time. Instead, acupuncture seemed to lengthen pregnancy and to prolong labor, for there was a positive correlation between the number of acupuncture treatments given and the length of gestation, second-stage labor and total delivery time. Based on the results of the present study, it appears possible that the effect of acupuncture is the opposite to that suggested by others, i.e. it lengthens the pregnancy as well as delivery time and does not reduce the duration of labor.

Acupuncture Therapy↗
PubMed1987

Endorphin activity in cerebrospinal fluid prior to elective cesarean section and in early puerperium.

Opioid activity in cerebrospinal fluid (CSF) was estimated by radioreceptor-assay (RRA) in samples obtained from ten women at term pregnancy and in the early puerperal period. The samples were fractioned on Sephadex G-10 columns and two opioid receptor active fractions, FI and FII, were recovered. Two pools of FII materials from pregnant and puerperal women, respectively, were further analyzed by electrophoresis and the concentrations of opioid activity were measured by radioreceptor assay. There was a significant rise in receptor-assayed FII opioid activity in late pregnancy as well as in the early puerperal period compared to that of healthy, nonpregnant, nonpuerperal females. Pooled FII material obtained before delivery could be separated into two major components tentatively assigned the hexapeptide [Met]enkephalin-Lys6 and the heptapeptide [Met]enkephalin-Arg6-Phe7. These two opioid peptides both have their origin in the [Met]enkephalin precursor, proenkephalin A. In the puerperal period there was predominance of only one of these components.

Adult↗
PubMed1987

Positron emission tomography: an animal model of spinal distribution of drugs after intrathecal administration.

An animal model has been developed in the Rhesus monkey for noninvasive monitoring of CSF transport of drugs by external detectors i.e. positron emission tomography. The model compromises the cannulation of the subarachnoid space (with a spinal needle), and has been used without any damage to the monkey. With the method it was shown that injection rate had a major influence on the transport rate of 68GaCl3 in the CSF. Injection of 0.5 ml over 60 sec gave the highest radioactivity near the injection site, whereas an injection rate of this volume over 10 sec resulted in high radioactivity more rostrally shortly after injection. This method have been of value for the determination of drug kinetics after spinal administration.

Animals↗
PubMed1987

Cerebrospinal fluid dynorphin1-17 and beta-endorphin in late pregnancy and six months after delivery. No influence of acupuncture treatment.

Cerebrospinal fluid (CSF) levels of dynorphin A and beta-endorphin were measured by radioimmunoassay in 62 primiparae in term pregnancy before onset of labour. In 50 of these women acupuncture (AP) treatment was given in an antenatal preparation procedure. In 15 of the AP-treated women, CSF samples were further obtained six months after delivery. Median values for dynorphin A were 7.5 pmol/l in AP-treated women and 6.4 pmol/l in non-treated controls. The puerperal median value for dynorphin A was 7.6 pmol/l. Median values for beta-endorphin were 7.1 pmol/l in AP-treated women and 5.7 pmol/l in non-treated controls. The median beta-endorphin value after delivery was 7.3 pmol/l. There was no significant difference in CSF dynorphin A or beta-endorphin levels between the AP-treated women and non-treated controls in late pregnancy. Consequently, the present study does not support the theory of a positive influence on either the dynorphin or the beta-endorphin system by manual AP. Within subject comparisons of dynorphin-A and beta-endorphin failed to indicate any significant trend in samples obtained in late pregnancy and 6 months after delivery, and there was no increased activity in either the dynorphin or the beta-endorphin system in late pregnancy, as reflected by CSF levels.

Acupuncture Therapy↗
PubMed1986

Structural studies of a teichoic acid from Streptococcus agalactiae type III.

An unusual type of teichoic acid has been isolated from Streptococcus agalactiae type III. It has the same backbone as the lipoteichoic acid from Streptococcus faecalis, but is devoid of fatty acid residues, a phosphatidyl group, and substituents in the poly(glycerol phosphate) side-chain. The following structure, with n approximately 20, was determined mainly with the aid of n.m.r. spectroscopy. (Formula: see text)

Carbohydrate Conformation↗
PubMed1986

Structural studies of a polysaccharide (S-88) elaborated by Pseudomonas ATCC 31554.

The structure of the extracellular polysaccharide elaborated by Pseudomonas ATCC 31554 has been investigated, methylation analyses, specific degradations, and 1H-n.m.r. spectroscopy being the main methods used. It is concluded that the polysaccharide is composed of pentasaccharide repeating-units with the structure: ----3)-beta-D-Glcp-(1----4)-beta-D-GlcpA-(1----4)-beta-D-Glcp- (1----4)-alpha-L-[Rha or Man]-(1---- 3 increases 1 alpha-L-Rha. An unusual feature is that a sugar residue in the chain may be either L-rhamnose or L-mannose. The polysaccharide also contains O-acetyl groups (approximately 5%) which have not been located.

Carbohydrate Conformation↗
PubMed1986

Structural studies of the O-specific side-chains of the Escherichia coli O 10 lipopolysaccharide.

The structure of the O-specific side-chains of the Escherichia coli O 10 lipopolysaccharide has been investigated. Methylation analysis, n.m.r. spectroscopy, and various specific degradations were the principal methods used. It is concluded that the polysaccharide is composed of pentasaccharide repeating-units having the following structure, in which D-Fuc4NAcyl is 4-amino-4,6-dideoxy-D-galactose, acylated with acetic acid (60%) or D-3-hydroxybutyric acid (40%). (Formula: see text).

Carbohydrate Conformation↗
PubMed1986

Structural studies of the O-antigen from Vibrio cholerae O:21.

The O-antigen from Vibrio cholerae O:21 has been investigated, using n.m.r. spectroscopy, methylation analysis, and Smith degradation as the main methods. It is concluded that the O-antigen is composed of tetrasaccharide repeating-units having the following structure (in which Hep = D-glycero-D-manno-heptose). (Formula: see text).

Antigens, Bacterial↗
PubMed1986

Distribution of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine in experimental animals studied by postiron emission tomography and whole body autoradiography.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a selective potent neurotoxin which has induced a syndrome similar to parkinsonism both in man and in monkeys. At autopsy degeneration of pigmented nerve cells in the pars compacta of the substantia nigra has been confirmed. The regional distribution of intravenously administered 1-(11C-methyl)-4-phenyl-1,2,3,6-tetrahydropyridine (11C-MPTP) in the brain of Rhesus monkeys was studied by positron emission tomography and the whole body distribution in mice was documented by autoradiography and by impulse counting of selected tissues. A very rapid and high uptake of 11C-MPTP derived radioactivity was seen in areas corresponding to striatum and midbrain, including the substantia nigra area. No elimination from these regions was seen during the study period of 2 h. The uptake was in the order of 7-8 times the homogenous distribution of the radioactivity in the monkey. The uptake was generally high also in other regions of the brain, but there some elimination could be distinguished. Pretreatment of the monkey with spiperone, a selective dopamine receptor antagonist, did not alter uptake nor the kinetics of the 11C-MPTP derived radioactivity. Thus 11C-MPTP does not have a high affinity for postsynaptic dopamine receptors. A remarkably high uptake of 11C-MPTP derived radioactivity was seen in the eye of the monkey. The selective uptake of radioactivity in the eye was also confirmed in pigmented but not in albino mice. The melanin affinity of MPTP may cause high intracellular concentrations of the compound or its metabolites in the melanin containing nerve cells in substantia nigra, which may explain the serious vulnerability of these neurons to MPTP.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗