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Biomedical subjects

C Nilsson

Publications and source records attributed to C Nilsson.

136 records · Page 8Linked to original sources
PubMedDate not supplied

Use of k-space segmentation in MR velocity mapping for rapid quantification of CSF flow.

In this work, a k-space segmentation technique for quantitative studies of pulsatile cerebrospinal fluid (CSF) flow is suggested. Three k-space lines are sampled for each of two interleaved gradient-echo sequences (velocity-compensated and velocity-encoded) within each repetition interval. Nine cardiac phases are obtained at a heart rate of 60 bpm with maintained nominal resolution and a factor of 3 in reduction of acquisition time relative to our conventional nonsegmented flow quantification protocol. Segmented and conventional sequences were compared in phantoms, in healthy volunteers, and in two patients with clinically suspected normal pressure hydrocephalus. Good agreement between flow curves obtained with the two sequences was demonstrated in vitro as well as in vivo. A slight underestimation of flow values in volunteers was attributed to data filtering when using the segmented sequence. Because the CSF circulation is complex and tightly connected to the vascular circulation, specific clinical applications may require flow studies at multiple positions and with different velocity encoding. In such cases, the proposed sequence can be used to gain time, but alternatively, the segmentation technique can be used to further increase spatial resolution within reasonable examination times.

Cerebrospinal Fluid↗
PubMedDate not supplied

Neuroendocrine regulatory mechanisms in the choroid plexus-cerebrospinal fluid system.

The CSF is often regarded as merely a mechanical support for the brain, as well as an unspecific sink for waste products from the CNS. New methodology in receptor autoradiography, immunohistochemistry and molecular biology has revealed the presence of many different neuroendocrine substances or their corresponding receptors in the main CSF-forming structure, the choroid plexus. Both older research on the sympathetic nerves and recent studies of peptide neurotransmitters in the choroid plexus support a neurogenic regulation of choroid plexus CSF production and other transport functions. Among the endocrine substances present in blood and CSF, 5-HT, ANP, vasopressin and the IGFs have high receptor concentrations in the choroid plexus and have been shown to influence choroid plexus function. Finally, the choroid plexus produces the growth factor IGF-II and a number of transport proteins, most importantly transthyretin, that might regulate hormone transport from blood to brain. These studies suggest that the choroid plexus-CSF system could constitute an important pathway for neuroendocrine signalling in the brain, although clearcut evidence for such a role is still largely lacking.

Animals↗
PubMedDate not supplied

Efficacy of inactivated whole HIV-2 vaccines with various adjuvants in cynomolgus monkeys.

Twenty-one cynomolgus monkeys were immunized with whole inactivated HIV-2 preparations administered with various adjuvants (incomplete Freund's adjuvant, Alum, Ribi, MDP, or Iscoms) and challenged with 10 or 100 MID50 of a homologous monkey-cell grown, cell-free HIV-2. Seven animals were completely protected against infection, three showed reduced virus replication. The vaccines elicited neutralizing and ADCC antibodies; the titers did not correlate with protection. Immunization with a whole inactivated vaccine can protect primates from intravenous challenge with a monkey-cell grown cell-free human immunodeficiency virus type 2.

AIDS Vaccines↗
PubMedDate not supplied

Proprioception in classical ballet dancers. A prospective study of the influence of an ankle sprain on proprioception in the ankle joint.

We studied prospectively the influence of ankle sprains on proprioception as measured by recording the postural sway of classical ballet dancers. Excellent balance and coordination are important for classical ballet dancers, and postural stability requires adequate proprioception from the ankle joint. Fifty-three professional dancers from the Royal Swedish Ballet, Stockholm, and 23 nonathletes, the control group, participated in the investigation. Postural sway was recorded and analyzed with a stabilimeter using a specially designed, portable, computer-assisted force plate. Six dancers sustained ankle sprains during followup. The recordings were obtained of these dancers before and after the injuries. The stabilometry results differed among the male and female dancers and the control group as follows: 1) the male dancers demonstrated a smaller total area of sway, and 2) both the male and female dancers had a smaller mean sway on the left foot than on the right (no mean difference in sway was found between the left and right foot in the control group). In comparison with the condition before injury and with the uninjured foot, the postural stability of the dancer was impaired for several weeks after the ankle sprain. Postural stability gradually improved during rehabilitation and improvement still occurred several weeks after professional dancing had resumed.

Adult↗
PubMedDate not supplied

A formalin inactivated whole SIVmac vaccine in Ribi adjuvant protects against homologous and heterologous SIV challenge.

Eight monkeys were immunized at 0, 4, 9, and 18 weeks with a total of 2 mg of formalin inactivated SIVmac vaccine with Ribi adjuvant. Two weeks after the last booster four immunized monkeys and two controls were challenged with 10 MID50 of live homologous virus SIVmac, and the remaining four vaccinated animals along with two controls were challenged with the heterologous SIVsm strain. All eight vaccinated monkeys resisted the virus challenge, whereas all controls became infected. Three months after the first challenge the monkeys were rechallenged with the same virus strain, without further boosting. Two of four vaccinated monkeys were still resistant to the homologous SIV strain, and three of four monkeys were resistant to the heterologous SIVsm strain. This study demonstrates vaccine induced cross-protection between SIV strains.

Adjuvants, Immunologic↗
PubMedDate not supplied

Histaminergic cells in the choroid plexus of rat.

The choroid plexus of the rat was examined immunocytochemically using both an antibody directed towards a histamine thyroglobulin conjugate as well as to histidine decarboxylase. Histamine- as well as histidine decarboxylase-immunoreactive cells were found within or in the vicinity of the plexus epithelium, with processes extending to the neighbouring epithelial cells or surrounding tissue, suggesting a specific function for histamine on the choroid plexus.

Animals↗
PubMedDate not supplied

Whole inactivated SIV vaccine grown on human cells fails to protect against homologous SIV grown on simian cells.

Several groups have reported protection against experimental SIV infection in macaques immunized with a whole inactivated virus vaccine. The aim of the current study was to investigate whether five macaques vaccinated with whole inactivated SIV and previously shown to be protected against challenge with two divergent strains of SIV grown on human cells could resist challenge with a subsequent homologous SIV grown on macaque cells. We show here that this same vaccine did not protect when the challenge virus was grown on primary cells of monkey origin.

AIDS Vaccines↗