Search PubMed⌕ Search

Biomedical subjects

B Karlsson

Publications and source records attributed to B Karlsson.

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

Toxicokinetics of soman in cerebrospinal fluid and blood of anaesthetized pigs.

The toxicokinetics of the four stereoisomers of the nerve agent C(+/-)P(+/-)-soman was analysed in cerebrospinal fluid (CSF) and blood in anaesthetized, spontaneously breathing pigs during a 90-min period after injection of soman. The pigs were challenged with different intravenous (i.v.) doses of C(+/-)P(+/-)-soman corresponding to 0.75-3.0 LD50 (4.5, 9.0 and 18 microg/kg in a bolus injection and 0.45 microg/kg per min as a slow infusion). Artificial ventilatory assistance was given if, after soman intoxication, the respiratory rate decreased below 19 breaths/min. Blood samples were taken from a femoral artery and CSF samples from an intrathecal catheter. The concentrations of the soman isomers were determined by gas chromatography coupled with high resolution mass spectrometry. All four isomers of soman were detected in both blood and CSF samples. The relatively non-toxic C(+/-)P(+) isomers disappeared from the blood stream and CSF within the first minute, whereas the levels of the highly toxic C(+/-)P(-) isomers could be followed for longer, depending on the dose. Concurrently with the soman analyses in blood and CSF, cholinesterase (ChE) activity and cardiopulmonary parameters were measured. C(+/-)P(-) isomers showed approx. 100% bioavailability in CSF when C(+/-)P(+/-)-soman was given i.v. as a bolus injection. In contrast, C(+/-)P(-) isomers displayed only 30% bioavailability in CSF after slow i.v. infusion of soman. The ChE activity in blood decreased below 20% of baseline in all groups of pigs irrespective of the soman dose. The effect of soman intoxication on the respiratory rate, however, seems to be dose-dependent and the reason for ventilatory failure and death. Artificial ventilation resulted in survival of the pigs for the time-period studied.

Anesthesia↗
PubMedDate not supplied

Recurrent tumor vs radiation effects after gamma knife radiosurgery of intracerebral metastases: diagnosis with PET-FDG.

OBJECTIVE: Our objective was to differentiate radiation effects from tumor progression in metastases stereotaxically irradiated with the multi-cobalt unit (Gamma Knife). MATERIALS AND METHODS: Eleven patients with stereotaxically irradiated cerebral metastases were examined with PET using [18F]fluorodeoxyglucose (FDG) to differentiate recurrent tumor from radiation effects. RESULTS: Six patients had increased uptake of FDG, and clinical, radiological, and pathological findings confirmed the diagnosis of recurrent metastases. These patients had an unfavorable prognosis and were all dead within 54 weeks after radiosurgery. Five patients had lesions without an increased accumulation of FDG. Four of these patients were alive after a total follow-up of 1.7 years, while one patient died of a peptic ulcer 56 weeks after radiosurgery. CONCLUSION: Positron emission tomography with FDG was of obvious prognostic value in this small series of patients and was clearly superior to CT and MR in the distinction between tumor recurrence and radiation effects (verified necrosis in one case).

Adult↗
PubMedDate not supplied

Brain and plasma proteins in spinal fluid as markers for brain damage and severity of stroke.

Forty well-defined acute stroke patients were investigated for some cerebro-spinal fluid (CSF) markers of cerebral damage. Myelin-basic protein (MBP), tau-fraction, albumin, IgG and transferrin were analyzed on two early occasions after onset of clinical symptoms. Patients with transitory ischaemic attack (TIA) had normal values for MBP both at first and second lumbar puncture. Patients with cerebral infarction and haemorrhage had mean MBP concentrations higher than normal at both lumbar punctures. In cerebral infarction there was a significant increase in MBP from the first to the second lumbar puncture. Patients with intracerebral haemorrhage showed the highest mean MBP values and MBP was markedly elevated already at the first lumbar puncture, suggesting different mechanisms of destruction of nervous tissue in cerebral infarction and bleeding. The amount of MBP was also significantly correlated to the visibility of the cerebral lesion at CT-scan and to the short-term outcome of the patients. The tau-fraction, indicating damage to grey matter, was higher than normal in the majority of patients with cerebral infarction and TIA. The concentration of MBP increases with the extent of brain lesion and a high value indicates a poor short-term prognosis for the patient. This study shows that the brain specific MBP in CSF is a useful marker of cerebral damage in acute cerebrovascular disease.

Acute Disease↗
PubMedDate not supplied

Stereotaxic angiography in gamma knife radiosurgery of intracranial arteriovenous malformations.

Gamma knife radiosurgery is an effective alternative to embolization or microsurgical removal of small arteriovenous malformations, particularly in eloquent areas of brain tissue. Stereotaxic angiography is a useful diagnostic and targeting adjunct to gamma knife radiosurgery, and the authors present their experience (1,100 patients) with methods and technique, and show how the nidus of the arteriovenous malformation can be defined angiographically. Dose planning employing digitization of the subtraction image enables determination of the spatial coordinates of the lesion by means of an interactive computer program.

Cerebral Angiography↗
PubMedDate not supplied

Elevated levels of myelin basic protein in CSF in relation to auditory brainstem responses in Bell's palsy.

Myelin basic protein (MBP) in the cerebrospinal fluid (CSF) was quantified from 28 patients with acute facial palsy. The mean value of MBP in CSF in the study group was 3.4 +/- 0.22 micrograms/l (mean +/- SEM), which was significantly higher than the found in 37 healthy subjects (2.4 +/- 0.13 micrograms/l). Using a 95% confidence interval, 10 patients demonstrated significantly increased CSF concentrations of MBP (greater than 3.95 micrograms/l). Auditory brainstem response (ABR) test showed that 5 patients had abnormal brainstem responses. No significant correlation was observed between elevated MBP in CSF and either pathologic auditory brainstem responses or the clinical degree of the palsy. These results suggest that a brainstem involvement may occur in patients with Bell's palsy. Furthermore, our data accord with previous reports suggesting Bell's palsy to be part of a polyneuropathy.

Adolescent↗
PubMedDate not supplied

Transfer of orally or intravenously administered proteins to the milk of the lactating rat.

Lactating rats were given a test solution containing various marker proteins via oral or intravenous routes. Using immunoprecipitation methods for the detection of ovalbumin (OvA), bovine serum albumin (BSA), and bovine gammaglobulins (BIgG) and radioimmunoassay for the analysis of beta-lactoglobulin (beta-LG), these proteins could be found in the blood serum and the milk of the rat 6 h after administration. A specific distribution pattern between the serum and the milk was observed for each protein. The results show that orally fed dietary proteins are able to cross the gut of the lactating rat and can be found in the serum and the milk. It was also observed that oral feeding of the proteins resulted in relatively greater concentrations in the milk than did intravenous administration. This very early presentation to the young of antigenic macromolecules derived from the mother's diet might be of importance for the development of a proper immunological response to common food antigens.

Administration, Oral↗