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Biomedical subjects

P O Tollesson

Publications and source records attributed to P O Tollesson.

13 recordsLinked to original sources

Asymptomatic visual loss in multiple sclerosis.

Visual disturbances are common in multiple sclerosis (MS) and often a result of acute demyelinating optic neuropathy. Careful examination of MS patients, who have never suffered optic neuritis, may also reveal asymptomatic visual loss. This type of silent disease activity was investigated by computerised resolution perimetry, which has the potential to reflect the percentage of functional retino-cortical neural channels. The time of onset and the evolution of asymptomatic visual loss was investigated. One approach was to retrospectively select patients who never had suffered acute optic neuritis from a closely monitored MS population and re-examine them again. Sixteen patients were identified and vision was evaluated during a period of 5.5-9 years of follow-up and compared with that in 14 healthy controls. The mean channel percentage of the MS group was 89 +/- 19 % (SD) on entry into the study, compared with 110 +/- 15% (SD) of controls (p < 0.003). At termination of the study the mean percentage was essentially unchanged both in MS patients (87 +/- 21%, SD) and controls (110 +/- 19%, SD). The second approach was to test a group of 7 patients with MS or strongly suspected MS, with the same method, in close connection with their first clinical exacerbation. All cases lacked visual symptoms and none had previously had acute visual loss. Again, virtually all performed subnormally in the vision tests, and to the same degree as in the first group of patients. Results were compared with those obtained from 25 MS patients who had experienced one or more attacks of optic neuritis. Compared with controls the loss of functional retino-cortical neural channels was 20% in patients without a previous history of optic neuritis and 30 % in patients who previously had experienced optic neuritis. We conclude that asymptomatic visual loss seems to be a universal feature of MS and has a substantial impact on the visual pathways, that it is present already at the time of clinical onset of the disease, and that any progression thereafter is slow enough to elude detection during several years of follow-up.

Adult↗

MRI staging using gadodiamide for soft-tissue tumors of the head and neck region. Results from a phase II trial and a 5-year clinical follow-up.

In order to document the safety, tolerability and efficacy of gadodiamide outside CNS, an open, non-drug comparative study was performed in patients with tumors of the head and neck region. Fifty adult patients were included and 48 patients received the contrast medium. The examinations were performed on a 1.5 T imager using transverse, non-enhanced T1- and PD-/T2-weighted conventional spin-echo sequences, followed by a contrast-enhanced transverse T1-weighted sequence. Post-contrast images provided more diagnostic information compared to unenhanced images in 33 of 48 patients (69%). This information was of significant help in four and of moderate help in 14 cases. Post-contrast images compared to non-enhanced T1-weighted showed improvement in lesion delineation for 29 of the 43 patients where a lesion was observed. Only in two patients was the diagnostic information lower post-contrast. A comparison between all pre-contrast images versus contrast medium enhanced showed post-contrast images to give more diagnostic information in 14 and less in nine patients. No patient experienced discomfort in relation to gadodiamide injection. Only one adverse event occurred which was described as thirst, being of moderate intensity. The 5-year clinical outcome was analyzed and compared with the pre-operative staging. The case-books of all patients were reviewed and in 44 patients all information could be found. Of those, 18 were still alive, one with active disease (AAD) and 17 with no evidence of disease (NED). Two of those four patients, where information was incomplete, showed NED and two had died. This trial showed that contrast-enhancement using gadodiamide for evaluation of soft tissue tumors in the head and neck region was safe and provided statistically significant more diagnostic information compared with unenhanced images. MRI, when compared with palpation/inspection, changed tumor staging in approximately 30% of all cases.

Contrast Media↗

Tolerance and efficacy of Omniscan (gadodiamide injection) in MR imaging of the central nervous system.

PURPOSE: This Swedish multicenter trial was performed on patients with known or suspected lesions of the CNS for which an MR examination using a contrast medium was indicated. A total of 8 MR centers participated in the study to establish the safety and efficacy of Omniscan (gadodiamide injection) in clinical routine using a standard dose of 0.1 mmol Gd/kg b.w. MATERIAL AND METHODS: Seven hundred adult patients who had been referred for MR investigation of suspected CNS lesions were included in the study. Since most patients were examined on an outpatient basis, it was decided to use an explicit questionnaire regarding adverse events that developed within 24 h after examination. The efficacy evaluation involved comparisons of detectability, delineation, and number of lesions before and after injection of Omniscan. RESULTS: No serious or unexpected adverse event was found. There were a total of 70 (10.2%) patients with adverse events, excluding those judged not to be contrast media-related. However, only 15 patients (2.2%) had adverse events that possibly or probably were related to the contrast medium. Usually, the symptoms were headache, dizziness, abnormal taste, and nausea. Two patients complained of itching, but only one developed urticaria. The efficacy was similar to that of other currently used Gd-based MR agents. Lesions were more often seen on T2-weighted images, but the contrast medium improved lesion delineation, contributing to higher certainty in diagnosis, and provided more confidence in excluding suspected abnormality. CONCLUSION: Omniscan was found to be a safe and clinically valuable contrast medium for MR imaging of the CNS.

Adolescent↗

Linomide reduces the rate of active lesions in relapsing-remitting multiple sclerosis.

The synthetic immunomodulator Linomide, a quinoline-3-carboxamide, has a profound inhibitory influence in several experimental autoimmune diseases, including acute and chronic experimental allergic encephalomyelitis. In a double-blind trial, 31 patients with relapsing-remitting multiple sclerosis were randomized to oral doses of 2.5 mg Linomide or placebo once a day for six months. Fourteen patients receiving Linomide and 14 receiving placebo completed the trial, and the results were based on this population. The mean number of active (new and enlarged T2 weighted) lesions per monthly MRI scan was 1.37 in the patients receiving Linomide and 4.22 in the patients receiving placebo (p = 0.043). The percentage of scans with active MRI lesions was lower in the Linomide-treated group (p = 0.0064). When neurologic deficit was assessed by the Regional Functional Scoring System (RFSS), the Linomide group showed an improvement of 1% of the maximal RFSS range and the placebo group a deterioration of 0.2% (p = 0.14). There were three patients with relapses in the Linomide-treated group and six in the placebo group (p = 0.22). A slightly decreased proportion of natural killer cells in cerebrospinal fluid and peripheral blood was noted in the Linomide group. A severe adverse event of pleuropericarditis occurred in one of the Linomide-treated patients. The most frequent adverse event was musculoskeletal pain, of mild to severe degree, which tended to diminish after three months on Linomide therapy.

Adjuvants, Immunologic↗

The microvascular changes in cases of hereditary multi-infarct disease of the brain.

A report on a cerebro-vascular disease with autosomal dominant inheritance, characterised by stroke-like episodes beginning in early adulthood and progressive dementia, afflicting one family living in Sweden was presented in 1977. Another afflicted member showing gait and coordination disturbances and impaired cognitive functions is now introduced. Magnetic resonance imaging revealed multiple brain lesions indicating ischaemic injuries. Previous autopsy studies of other cases revealed white matter atrophy, multiple infarcts and lacunes. In one patient who had died from a cerebral haemorrhage, obliteration of intracerebral arteries, occasionally with organised thrombi was present. Autopsy material has now been reinvestigated with special attention to changes of intracerebral arterioles. Cases with long duration of the disease presented pronounced fibrous thickening of the wall of numerous intracerebral arterioles, degeneration of smooth muscle cells of the media and obliteration of the lumen. Immunohistochemistry showed marked expression of fibrillary collagen types I, III and V and of the basal lamina components collagen type IV and laminin. These depositions are probably induced by some primary dysfunction of smooth muscle cells or endothelial cells. Perivascular reactive astrocytes with endothelin-1-like immunoreactivity were present in some brain regions. Endothelin-1 is the most powerful vasoconstrictor peptide known to date. Structural remodelling of intracerebral arterial vessels, actions of different vasoactive factors and rheological disturbances may all interfere with local blood flow in this disease and cause the parenchymal changes of the brain.

Adult↗

Patterns of propulsive motility in the human colon after abdominal operations.

Twenty patients about to undergo elective cholecystectomy who were not using laxatives or drugs known to affect gastrointestinal motility and who did not give a history of gastrointestinal disease were investigated in a prospective open study. Patients swallowed two capsules each containing four radio-opaque markers every 12 hours starting 48 hours before operation. The pattern of resolution of postoperative colonic paralysis was monitored by serial abdominal radiographs taken every 12 hours until motility had returned to the rectum/sigmoid colon. In all 17 patients who completed the study propulsive motility started significantly earlier in the right colon (mean 61 hours) than in any other part (p less than 0.01). The gradient of resolution of postoperative colonic paralysis was always from proximal to distal, adding to the accumulating body of experimental evidence that implicates the right colon to return to normal first.

Abdomen↗

Treatment of postoperative paralytic ileus with cisapride.

The effect of cisapride on postoperative colonic motility was studied in 40 patients undergoing cholecystectomy under randomized, double-blind conditions. The patients received 10 mg of cisapride or placebo by intravenous injection starting on the day of surgery and repeated every 12 h until the 3rd postoperative day. The return of propagative motility in the colon was visualized by means of radiopaque markers and serial abdominal radiographs. Cisapride induced a significantly earlier return of propulsive motility in the right colon, as indicated by the propagation of markers from the ascending colon to the transverse colon (p less than 0.05). Radiopaque markers reached the descending colon (p less than 0.05) and the rectosigmoid colon (p less than 0.05) significantly earlier in the cisapride group than in controls. The first passage of feces occurred significantly earlier in cisapride-treated patients than in controls (p less than 0.05). The first passage of gas after surgery did not differ significantly between the groups. Our results suggest that cisapride can be used to induce earlier return of propagative motility in the colon after major abdominal surgery.

Cholecystectomy↗

A radiologic method for the study of postoperative colonic motility in humans.

Propulsive colonic motility in the postoperative period was studied, in 49 patients undergoing cholecystectomy, by means of radiopaque markers, water-soluble contrast, and serial abdominal radiographs. The colon was divided into four segments, and the propagation of the markers and contrast to the segments was registered. Marker propagation correlated significantly with the propagation of the contrast to all segments of the colon (p less than 0.001). The first postoperative passage of gas did not correlate significantly with the propagation of the markers or the contrast to the various colonic segments. The first passage of faeces postoperatively did not correlate significantly with the return of propulsive motility in the right colon; however, there was a significant correlation with the propulsion of markers to the descending colon (p less than 0.05) and the rectosigmoid colon (p less than 0.05). The duration of postoperative paralytic ileus, as measured by the start of propagation of the markers from the caecum, correlated directly with the consumption of opiate analgesics in the postoperative period (p less than 0.01) but inversely with age (p less than 0.05). The duration of surgery did not correlate significantly with the duration of paralytic ileus in the colon. In conclusion, a limited number of radiopaque markers can be used to study the return of postoperative propulsive motility in the colon. The first postoperative passage of gas is not an indicator of the duration of postoperative paralytic ileus, whereas the first passage of faeces is primarily representative of the return of propagative motility in the left colon.

Adult↗

Lack of effect of metoclopramide on colonic motility after cholecystectomy.

The effect of metoclopramide on postoperative colonic ileus was evaluated in a randomised, double-blind study in 20 patients after cholecystectomy. The start of propulsive colonic motility and colonic transit time after operation were measured by radio-opaque markers and serial abdominal radiographs. Metoclopramide 20 mg given intravenously three times a day until the fourth postoperative day (n = 10) did not significantly reduce the duration of postoperative colonic paralysis compared with control patients (n = 10), nor were there any differences between the groups when the time of first postoperative passage of gas and faeces were compared. In conclusion, the use of metoclopramide in the postoperative period did not result in a quicker return of propulsive motility in the right or left colon as judged by the radio-opaque markers and serial abdominal radiographs.

Cholecystectomy↗

Treatment of postoperative paralytic ileus by intravenous lidocaine infusion.

The effects of continuous intravenous infusion of lidocaine on postoperative paralytic ileus in cholecystectomized patients was investigated in this double-blind study. An infusion of lidocaine (3 mg/min, n = 15) or an infusion of an equal volume of saline (n = 15) was started 30 min before induction of anesthesia and continued for 24 h after surgery. Postoperative colonic motility was evaluated by radiopaque markers and serial abdominal radiographs. A record was kept of the first passage of gas and feces. Results showed significantly earlier return of propulsive motility in the colon of lidocaine-treated patients. Radiopaque markers in the lidocaine group were propelled significantly earlier from the cecum/ascending colon to the transverse colon (P less than 0.05) and appeared significantly earlier in the descending colon (P less than 0.05) and the rectosigmoid colon (P less than 0.05) than in saline-treated patients. Despite the fact that the mean time for postoperative defecation occurred 17 h earlier in lidocaine-treated patients, differences between the groups were not statistically significant--a fact due, perhaps, to great individual variations in defecation habits. The time to first passage of gas, a variable representative of changes in anorectal or colonic tone rather than propagative motility, also did not differ significantly between the groups. No adverse reactions to lidocaine were reported. The results suggest that continuous intravenous infusion of lidocaine during the first postoperative day shortens the duration of paralytic ileus in the colon after abdominal surgery. Suppression of inhibitory gastrointestinal reflexes by reduction of postoperative peritoneal irritation is suggested as the mechanism of action.

Cholecystectomy↗

Effect of intra-abdominal bupivacaine instillation on postoperative colonic motility.

Effect of intra-abdominal instillation of a local anaesthetic, bupivacaine, on postoperative colonic adynamic ileus was studied in a double blind manner in a randomised series of patients undergoing upper laparotomy. Propulsive colonic activity was studied postoperatively with radio-opaque markers and serial abdominal radiographs. Intra-abdominal instillation of bupivacaine 2 mg/kg bw significantly shortened the period of postoperative colonic inhibition (p less than 0.01), but did not hasten colonic transit. Furthermore, bupivacaine significantly decreased the hyperglycaemic response to surgery. It is suggested that bupivacaine inhibits the inflammatory response within the bowel wall, a response which may maintain the inhibitory spinal reflexes in the postoperative period. Blood concentrations of bupivacaine were shown to be well below toxic levels and no adverse reactions were observed.

Abdomen↗

Failure of epidural anesthesia to prevent postoperative paralytic ileus.

This study used radiopaque markers and serial abdominal radiographs to assess the effect of epidural anesthesia on postoperative colonic ileus. Epidural anesthesia did not result in significantly faster return of propulsive motility in the colon after surgery as compared with control (P greater than 0.05). In addition, no significant difference was seen between the groups in colonic transit time and time for the first passage of gas and feces. The level of inhibition of sympathetic efferent nerves to the abdominal cavity was assessed by repeated measurements of blood glucose levels during the first postoperative day. Blood glucose levels were found to be significantly lower in the epidural group, demonstrating an inhibition of efferent sympathetic nerves below the level of T-5. Results show lack of effect of continuous epidural anesthesia in the prevention of postoperative paralytic ileus and suggest that mechanisms other than spinal reflexes play a major part in the development and maintenance of intestinal paralysis.

Anesthesia, Epidural↗