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| 3. |
- Eklund, Anders, et al.
(författare)
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Infusion technique can be used to distinguish between dysfunction of a hydrocephalus shunt system and a progressive dementia
- 2004
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Ingår i: Medical and Biological Engineering and Computing. - : Springer. - 0140-0118 .- 1741-0444. ; 42:5, s. 644-649
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Tidskriftsartikel (refereegranskat)abstract
- In a deteriorating shunted patient with hydrocephalus, an investigation of shunt function is often performed to distinguish a dysfunctioning shunt from an aggravated condition of the disease. The paper illustrates how a lumbar cerebrospinal fluid (CSF) infusion method can be used to evaluate post-operative deterioration in a shunted patient in order to give the physician valuable support in the shunt revision decision. A 77-year-old man with hydrocephalus was treated operatively by the insertion of a CSF shunt. Owing to shunt failure, the shunt was revised twice during a 5 year period. Using a computerised infusion technique method, with two needles placed in the lumbar subarachnoid space, the CSF dynamic system was determined pre- and post-operatively with the functioning as well as the dysfunctioning shunts. The data were verified with a bench-test of the extirpated CSF shunt. There was a significant difference in conductance G between CSF systems with an open shunt and CSF systems with no shunt or an occluded shunt (ΔG=38mm3 s−1 kPa−1, p=0.014, n=7, ANOVA). CSF dynamics investigations, with and without a shunt, can give valuable clinical support in the management of a deteriorating hydrocephalus patient. With further development of the lumbar infusion method moving towards easy-to-use equipment, there is potential for widespread clinical use.
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| 4. |
- Grenander, A., et al.
(författare)
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Antithrombin treatment in patients with traumatic brain injury : a pilot study
- 2001
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Ingår i: J Neurosurg Anesthesiol. ; 13:1, s. 49-56
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Tidskriftsartikel (refereegranskat)abstract
- This study will determine if early administration of antithrombin concentrate to patients with traumatic brain injury (TBI) can inhibit or significantly shorten the time of coagulopathy. The progress of brain injury monitored by computed tomographic scan (CT) was also assessed, as was the time needed for intensive care and outcome related to Glasgow outcome scale (GOS). Twenty-eight patients with isolated brain trauma verified with CT were included in either of two parallel groups. The Glasgow coma score (GCS) was mean 7.5, and median 7.0; signifying a moderate to severe traumatic brain injury but with a mortality of only 3.5%. The patients randomized to antithrombin treatment received a total of 100 U/kg BW during 24 hours. To measure hypercoagulability, soluble fibrin (SF), D-dimer (D-d), and thrombin-antithrombin complex (TAT) were assessed together with antithrombin (AT) and routine coagulation tests. Before treatment, SF, D-d, and TAT were markedly increased in both groups. Soluble fibrin and D-dimer (measured after treatment began) appeared to decrease faster in the AT group, and there was a statistically significant difference between the groups at 36 hours for SF and at 36 hours, 48 hours, and at Day 3 for D-d. Thrombin-antithrombin complex levels were very high in both groups but, surprisingly, showed no significant difference between the groups. The authors conclude that antithrombin concentrate administered to patients with severe TBI resulted in a marginal reduction of hypercoagulation. We could not detect any obvious influence by antithrombin on brain injury progress, on CT, or on outcome or time needed for intensive care.
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| 5. |
- Johansson, M., et al.
(författare)
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Interleukin-2 and histamine in combination inhibit tumour growth and angiogenesis in malignant glioma
- 2000
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Ingår i: British Journal of Cancer. - : Cancer Research Campaign. - 0007-0920 .- 1532-1827. ; 83:6, s. 826-832
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Tidskriftsartikel (refereegranskat)abstract
- Biotherapy including interleukin-2 (IL-2) treatment seems to be more effective outside the central nervous system when compared to the effects obtained when the same tumour is located intracerebrally. Recently published studies suggest that reduced activity of NK cells in tumour tissue can be increased by histamine. The present study was designed to determine whether IL-2 and histamine, alone or in combination, can induce anti-tumour effects in an orthotopic rat glioma model. One group of rats was treated with histamine alone (4 mg kg(-1)s.c. as daily injections from day 6 after intracranial tumour implantation), another group with IL-2 alone as a continuous subcutaneous infusion and a third group with both histamine and IL-2. The animals were sacrificed at day 24 after tumour implantation. IL-2 and histamine in combination significantly reduced tumour growth. The microvessel density was significantly reduced, an effect mainly affecting the small vessels. No obvious alteration in the pattern of VEGF mRNA expression was evident and no significant changes in apoptosis were observed. Neither IL-2 nor histamine alone caused any detectable effects on tumour growth. Histamine caused an early and pronounced decline in tumour blood flow compared to normal brain. The results indicate that the novel combination of IL-2 and histamine can be of value in reducing intracerebral tumour growth and, thus, it might be of interest to re-evaluate the therapeutic potential of biotherapy in malignant glioma.
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- Karlsson, Britt M., et al.
(författare)
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Nimodipine affects the microcirculation and modulates the vascular effects of acetylcholinesterase inhibition
- 2003
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Ingår i: Upsala Journal of Medical Sciences. - : Taylor & Francis. - 0300-9734 .- 2000-1967. ; 108:2, s. 141-149
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Tidskriftsartikel (refereegranskat)abstract
- The present investigation was undertaken in order to study whether microvascular effects of the calcium antagonist nimodipine induces changes that can explain an increased detoxification of the highly toxic cholinesterase inhibitor soman. Anaesthetised, tracheotomised and artificially ventilated rats were treated intra-peritoneally (ip) with nimodipine, 10 mg kg(-1) or vehicle followed one hour later by the exposure to 45 microg kg(-1) soman (iv). Nimodipine per se induced a vasodilation in the intestine, myocardium and other muscles. In the abdominal skin soman elicited a significant vasoconstriction that was turned into an increased blood flow after nimodipine pre-treatment. A slight vasoconstriction in diaphragm of soman intoxicated rats was turned into a significant vasodilation by nimodipine pre-treatment. In the intestinal parts no effect of soman was detected. However, in nimodipine pretreated animals soman induced a significant vasoconstriction. The capacity of soman detoxifying processes, i.e. enzymatic hydrolysis and covalent binding to different esterases, is unequally distributed throughout the body. Together with the knowledge of the detoxifying processes of cholinesterase inhibition the results support our theory, that nimodipine alters the peripheral blood flow in a beneficial way resulting in improved detoxification ability.
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| 7. |
- Koskinen, Lars-Owe D., Professor, 1955-, et al.
(författare)
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Cerebrovascular effects of the TRH analogues pGlu-3-methyl-His-Pro amide and pGlu-Glu-Pro amide : a comparison with TRH.
- 2000
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Ingår i: Upsala Journal of Medical Sciences. - : Upsala Medical Society. - 0300-9734 .- 2000-1967. ; 105:1, s. 73-83
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Tidskriftsartikel (refereegranskat)abstract
- The goal of the study was to assess whether TRH analogues possess cerebrovascular effects similar to the native peptide. The neuropeptide thyrotropin releasing hormone (TRH) elicits cerebrovasodilation in several species under various conditions. The laser-Doppler method was employed to study the effects of TRH and the analogues pGlu-3-methyl-His-Pro amid (M-TRH) and pGlu-Glu-Pro amide. Intravenous (i.v.) injection of 300 microg kg(-1) of TRH elicited cerebrovasodilation and a 62% increase in blood flow within 1 minute. M-TRH, in a dose of 300 microg kg(-1) i.v., elicited a 80% increase in cerebral blood flow. Even a minute dose of M-TRH (625 ng kg(-1)) caused an increase in cerebral blood flow. No clear difference in effects on the cerebral blood flow was observed between spontaneously and mechanically ventilated animals, pGlu-Glu-Pro amide had no cerebrovascular effect.
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| 8. |
- Koskinen, Lars-Owe D., Professor, 1955-, et al.
(författare)
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Cigarette smoke and hypoxia induce acute changes in the testicular and cerebral microcirculation
- 2000
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Ingår i: Upsala Journal of Medical Sciences. - : Taylor & Francis. - 0300-9734 .- 2000-1967. ; 105:3, s. 215-226
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Tidskriftsartikel (refereegranskat)abstract
- The acute effects of cigarette smoking and hypoxia on the cerebral and testicular microcirculation were studied in anestethised adult rats. Smoking for 2 min did not influence arterial pO2, pCO2 or pH but it induced an increase in cerebral blood flow by 34% and inhibited vasomotion in the testis for about 1 h. One hour after smoke exposure apnea induced a slight increase in arterial pCO2, a significant decrease in pO2, and an increase in cerebral blood flow (CBF) by 54%. In animals not previously exposed to cigarette smoke apnea increased CBF by 121%, demonstrating that a short-term exposure to tobacco smoke influences the cerebrovascular reactivity for more than one hour. In the testis, apnea resulted in a decreased blood flow by 39% and a complete depression of vasomotion. Breathing 10% O2/90% N2 resulted in moderate hypoxia, a total disappearance of the vasomotion in the testis, a 24% decrease in testicular blood flow, but a 23% increase in CBF.Our results indicate that short-term exposure to tobacco smoke induces marked acute vascular effects in both the brain and the testis. Apnea and moderate hypoxia elicited totyally different effects in the brain and testis, inicating different vascular control mechanisms.
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| 9. |
- Koskinen, Lars-Owe D., Professor, 1955-, et al.
(författare)
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Nitric oxide inhibition by L-NAME but not 7-NI induces a transient increase in cortical cerebral blood flow and affects the cerebrovasodilation induced by TRH
- 2003
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Ingår i: Peptides. - : Elsevier. - 0196-9781 .- 1873-5169. ; 24:4, s. 579-583
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Tidskriftsartikel (refereegranskat)abstract
- The tripeptide thyrotropin releasing hormone (TRH) has multiple interesting and complex physiological effects. One of these is the cerebrovasodilating effect, which has been described under several different conditions. The final mechanism for this effect is unknown. In the present study, we found an initial atropine-resistant cerebral vasodilation (24%) elicited by the NOS inhibitor L-NAME in the rat. D-NAME and 7-NI did not produce this effect. TRH (300 microg kg(-1), i.v.) induced an increase in cerebral blood flow by 62%. L-NAME reduced this effect significantly. The cerebrovasodilating mechanism of TRH, at least in part, is endothelial NO dependent as the neuronal 7-NI NOS inhibitor does not affect the TRH response.
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| 10. |
- Lehtipalo, Stefan, et al.
(författare)
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Cutaneous sympathetic vasoconstrictor reflexes for the evaluation of interscalene brachial plexus block
- 2000
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Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172 .- 1399-6576. ; 44:8, s. 946-952
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Tidskriftsartikel (refereegranskat)abstract
- Background: Although signs of sympathetic blockade following interscalene brachial plexus block include Horner’s syndrome, increased skin temperature and vasodilatation, the degree of sympathetic blockade is not easily determined. The aim of this study was, therefore, to use activation of cutaneous finger pad vasoconstrictor reflexes for description and quantification of the degree of sympathetic blockade following unilateral interscalene brachial plexus block.Methods: Eight patients scheduled for acromioplasty under general anesthesia were studied. An interscalene plexus catheter was inserted preoperatively on the side to be operated upon and used postoperatively for administration of bupivacaine, given as a bolus (1.25 mg kg−1) followed by a continuous infusion (0.25 mg kg−1 h−1). Skin blood flow (SBF) in the pad of the index finger was assessed by the laser Doppler technique, and regional skin vascular resistance (RVR) was calculated. The inspiratory gasp test (apnea at end‐inspiration) or a local heat provocation were used as provocations of the cutaneous microcirculation.Results: Interscalene brachial plexus block increased SBF and decreased RVR at rest, and produced satisfactory sensory and motor block. The inspiratory gasp test decreased SBF and increased RVR in the unblocked arm, while the opposite, increased SBF and decreased RVR, were observed during local heat provocation. In the blocked arm, these gasp‐induced cutaneous vasoconstrictor and heat‐induced vasodilator responses were attenuated.Conclusions: Interscalene brachial plexus block reduces regional sympathetic nervous activity, illustrated by increases in skin blood flow, skin temperature and attenuated vasoconstrictor responses to an inspiratory gasp. The inspiratory gasp vasoconstrictive response is a powerful and sensitive indicator for monitoring the sympathetic blockade following interscalene brachial plexus block.
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