Single-dose intravenous iron infusion or oral iron for treatment of fatigue after postpartum haemorrhage: a randomized controlled trial

BACKGROUND AND OBJECTIVES

To evaluate the clinical efficacy of a single-dose intravenous infusion of iron isomaltoside compared with current treatment practice with oral iron measured by physical fatigue in women after postpartum haemorrhage.

MATERIALS AND METHODS

Single-centre, open-label, randomized controlled trial. Participants received intravenous iron (n = 97) or oral iron (n = 99), and completed the Multidimensional Fatigue Inventory and Edinburgh Postnatal Depression Scale, and haematological and iron parameters were measured. Primary outcome was the aggregated change in physical fatigue score from baseline to 12 weeks postpartum.

RESULTS

The difference in physical fatigue score was -0·97 (95% CI: -1·65; -0·28, P = 0·006) in favour of intravenous iron, but did not meet the predefined difference of 1·8. Across visits, we found statistically significant differences in fatigue and depression scores, as well as in haematological and iron parameters, all in favour of intravenous iron. There were no serious adverse reactions.

CONCLUSION

A single dose of intravenous iron was associated with a statistically significant reduction in aggregated physical fatigue within 12 weeks after postpartum haemorrhage compared to standard medical care with oral iron below the prespecified criteria of clinical superiority. As patient-reported outcomes improved significantly and intravenous iron resulted in a fast hematopoietic response without serious adverse reactions, intravenous iron may be a useful alternative after postpartum haemorrhage if oral iron is not absorbed or tolerated.

Single-dose intravenous iron infusion versus red blood cell transfusion for the treatment of severe postpartum anaemia: a randomized controlled pilot study

BACKGROUND AND OBJECTIVES

There are no randomized trials comparing intravenous iron to RBC transfusion for the treatment of severe postpartum anaemia. The objectives of this study were to evaluate the feasibility of randomizing women with severe postpartum anaemia secondary to postpartum haemorrhage to RBC transfusion or intravenous iron, and to describe patient-reported outcomes, and haematological and iron parameters.

MATERIALS AND METHODS

Women with a postpartum haemorrhage exceeding 1000 ml and an Hb between 5·6 and 8·1 g/dl were randomized to 1500 mg of intravenous iron (n = 7) isomaltoside or RBC transfusion (n = 6). Participants completed the Multidimensional Fatigue Inventory and Edinburgh Postnatal Depression Scale, and blood samples were drawn at inclusion, daily during the first week and at weeks 3, 8 and 12.

RESULTS

We screened 162 women and included 13 (8%). There was no significant difference between groups in fatigue or depression scores. RBC transfusion was associated with a higher Hb on day 1, inhibition of reticulocytosis during the first week and low iron levels. Intravenous iron was associated with increased reticulocytosis during the first week, repleted iron stores and a higher Hb in weeks 3-12.

CONCLUSION

This pilot study shows that intravenous iron could be an attractive alternative to RBC transfusion in severe postpartum anaemia, and that a larger trial is needed and feasible.

Sporadic Hemiplegic Migraine is an Aetiologically Heterogeneous Disorder

In order to better understand sporadic hemiplegic migraine (SHM) and particularly its relation to familial hemiplegic migraine (FHM), migraine without aura (MO) and typical migraine with aura (typical MA), we investigated the occurrence of MO and typical MA among probands with SHM and their first-degree relatives. The pattern of familial aggregation of MO and typical MA was assessed by population relative risk calculations. A total of 105 SHM probands and 483 first-degree relatives were identified in the Danish population. Compared with the general population, SHM probands had no increased risk of MO, but a highly increased risk of typical MA. First-degree relatives of all SHM probands had an increased risk of both MO and typical MA, whereas first-degree relatives of probands with exclusively SHM had no increased risk of MO but an increased risk of typical MA. Our data suggest that SHM is a genetically heterogeneous disorder.

Sporadic Hemiplegic Migraine

Sporadic hemiplegic migraine (SHM) is defined as migraine attacks associated with some degree of motor weakness/hemiparesis during the aura phase and where no first degree relative (parent, sibling or child) has identical attacks. The present review deals with recent scientific studies according to which: The SHM prevalence is estimated to be 0.005%; SHM patients have clinical symptoms identical to patients with familial hemiplegic migraine (FHM) and significantly different from patients with migraine with typical aura (typical MA); SHM affected had no increased risk of migraine without aura (MO), but a highly increased risk of typical MA compared to the general population; SHM patients only rarely have mutations in the FHM gene CACNA1A; SHM attacks in some cases can be treated with Verapamil. The reviewed data underlie the change in the International Classification of Headache Disorders 2nd edition where SHM became separated from migraine with typical aura or migraine with prolonged aura. All cases with motor weakness should be classified as either FHM or SHM.

The Effect of Propranolol on Glyceryltrinitrate-Induced Headache and Arterial Response

Prophylactic drug trials in migraine are long-lasting and expensive and require long-term toxicology information. A human migraine model would therefore be helpful in testing new drugs. Immediate headache and delayed migraine after glyceryltrinitrate (GTN) has been well characterized. We have recently shown that sodium valproate has prophylactic effect in the GTN model. Here we report our experience with propranolol in this model. Nineteen subjects with migraine without aura and 16 sex- and aged-matched healthy subjects were included in a two-centre randomized double-blind cross-over study. Fourteen migraine subjects and 14 healthy subjects completed the study and results from comparison of the 28 subjects are reported. Randomly propranolol 160 mg or placebo were each given daily for 14 days to both migraine and healthy subjects. A 20-min intravenous infusion of GTN 0.25 mg/kg per min was administered on a study day at the end of both pretreatment periods. Headache was registered for 12 h after GTN infusions. Its intensity was scored on a numerical verbal rating scale from 0 to 10. Fulfilment of International Headache Society (HIS) criteria was recorded for 24 h. Radial and superficial temporal artery diameters and blood velocity of both middle cerebral arteries were measured. All migraine subjects developed headache after GTN. No reduction of overall peak headache was found after propranolol (median 5, range 0-7) compared with placebo (median 5, range 0-10) ( P = 0.441). Eight of the 14 completing migraine subject developed IHS 1.1 migraine after GTN, two subjects on both days, three subjects only after placebo, and three subjects only after propranolol. No reduction of GTN-induced migraine was found after propranolol compared with placebo (5 vs. 5, P = 1.000). All healthy subjects developed headache after GTN. No reduction of overall peak headache was found after propranolol (median 2, range 1-5) compared with placebo (median 1, range 1-7) ( P = 0.315). Two subjects fulfilled IHS criteria 1.1 for migraine without aura after propranolol but not after placebo. The fulfilment was short lasting and did not require rescue medication. Headache after GTN was more pronounced in migraine subjects than in healthy subjects both with ( P = 0.003) and without pretreatment with propranolol ( P = 0.017). We found that 2 weeks of propranolol constricted the radial artery in healthy subjects but not in migraine subjects. GTN-induced vasodilatation abolished this difference. Mean maximum blood flow velocity in the middle cerebral artery was higher in healthy subjects than in migraine patients ( P = 0.003-0.033) and unaffected by propranolol. We observed no effect of propranolol on GTN-induced headache and migraine. This could indicate that GTN induces migraine at a deeper level of the pathophysiological cascade of migraine than the prophylactic effect of propranolol. Propranolol does not constrict cerebral arteries, which therefore cannot be part of its mechanism of action in migraine.

Prognosis of Migraine with Aura

The present study is a 16-year follow-up study assessing the long-term outcome of migraine with aura (MA). Additionally possible predictive factors in the prognosis of MA were evaluated. Patients were recruited from the files of Danish headache clinics. A total of 53 patients (11M:42F) with MA (IHS criteria) participated in a follow-up interview. At follow-up attacks had ceased (no MA for 2 years) in 36% of patients. Attacks had ceased in 55% of males and 31% of females ( P = 0.17). Attacks had ceased in 41% of patients with visual aura without other aura symptoms and in 25% of those with sensory or aphasic aura besides their visual aura ( P = 0.36). Among those with attacks of MA at follow-up frequency of attacks and headache intensity was improved in 44% and 41% of the patients, respectively. The results point to a favourable evolution of MA and suggest possible predictive factors.

Clinical Characteristics of 362 Patients with Familial Migraine with Aura

The objectives of the present study were to describe the clinical characteristics of patients with severe familial non-hemiplegic migraine with aura (NHMA) and to compare these data to those from cases in previous population-based Danish studies using the same methodology. NHMA families were recruited from the Danish patient registry and from Danish neurology practices. A total of 362 NHMA patients were diagnosed according to the 1988 International Headache Society criteria using a validated semistructured physician-conducted interview. Visual aura occurred in almost every NHMA attack. In aura without headache visual aura occurred primarily in isolation. Aura without headache was most common in older, male patients. Several clinical characteristics of familial NHMA differed from migraine with aura in the general population: firstly, the age at onset was lower, secondly, the age at cessation was higher, thirdly, aura symptoms were more severe and finally, the co-occurrence of migraine without aura was higher in familial NHMA. There seems to be a correlation between more severe symptoms and familial aggregation. These results have both clinical and scientific implications.

Intravenous iron isomaltoside 1000 (Monofer®) reduces postoperative anaemia in preoperatively non-anaemic patients undergoing elective or subacute coronary artery bypass graft, valve replacement or a combination thereof: a randomized double-blind placebo-controlled clinical trial (the PROTECT trial)

Background and Objectives

This trial explores whether intravenous iron isomaltoside 1000 (Monofer®) results in a better regeneration of haemoglobin levels and prevents anaemia compared to placebo in preoperative non-anaemic patients undergoing cardiac surgery.

Study Design and Methods

The trial is a prospective, double-blind, comparative, placebo-controlled trial of 60 non-anaemic patients undergoing cardiac surgery. The patients were randomized 1:1 to either 1000 mg intravenous iron isomaltoside 1000 administered perioperatively by infusion or placebo.

Results

Mean preoperative haemoglobin in the active treatment group was 14·3 g/dl vs. 14·0 g/dl in the placebo group. At discharge 5 days after surgery, haemoglobin levels were reduced to 10·7 and 10·5 g/dl, respectively. One month after surgery, haemoglobin concentration had increased to an average of 12·6 g/dl vs. 11·8 g/dl (p = 0·012) and significantly more patients were non-anaemic in the intravenous iron isomaltoside 1000-treated group compared to the placebo group (38·5% vs. 8·0%; p = 0·019). There were no differences in side-effects between the groups.

Conclusion

A single perioperative 1000 mg dose of intravenous iron isomaltoside 1000 significantly increased the haemoglobin level and prevented anaemia 4 weeks after surgery, with a short-term safety profile similar to placebo. Future trials on potential clinical benefits of preoperative treatment with intravenous iron in non-anaemic patients are needed.

A nitric oxide donor (nitroglycerin) triggers genuine migraine attacks

Supersensitivity to induction of headache and arterial dilatation by a donor of nitric oxide (nitroglycerin) has recently been demonstrated in migraine sufferers. The aims of the present study were to examine whether the nitric oxide donor nitroglycerin may induce a typical migraine attack, to exclude placebo-related effects and to describe the relation between middle cerebral artery dilatation and provoked migraine. Nitroglycerin (0.5 μg/kg/min for 20 min) or placebo was infused into 12 migraine patients in a double-blind cross-over trial. Blood velocity in the middle cerebral artery was measured with transcranial Doppler and characteristics of headache and accompanying symptoms were recorded frequently. Headache occurred during the nitroglycerin infusion as previously described but peak headache intensity did first occur 5.5 h after infusion. At this time the induced headaches in 8 of 10 completing patients fulfilled the diagnostic criteria for migraine without aura of the International Headache Society. Furthermore, all patients who normally had unilateral spontaneous migraine attacks also had unilateral headaches after nitroglycerin. Only one subject developed migraine after placebo (p < 0.03). The time pattern of headache and estimated middle cerebral artery dilatation corresponded well. The study therefore demonstrates that activation of the nitric oxide cGMP pathway may cause typical migraine attacks.

Effects of IV iron isomaltoside-1000 treatment on regional brain iron status in an iron-deficient animal

BACKGROUND

Iron deficiency has been documented to affect human cognitive function and conditions with brain iron compromise such as the restless legs syndrome (RLS). Intravenous (IV) iron treatment is used to reduce iron deficiency but its effects on brain iron are not known. It is not known if IV iron is effective in correcting regional brain iron deficiencies nor if it poses a risk of producing iron overload in some brain regions. Preclinical study of IV iron in the iron-deficient (ID) murine model is needed to evaluate and develop IV iron treatments for brain iron deficiency.

METHODS

Response to tail vein injections of iron (iron isomaltoside-1000, dose equivalent to 1000 mg for 75 kg adult) or vehicle were evaluated for ID mice by microdialysis assessing non-transferrin bound (NTB) iron in the ventral midbrain (VMB) and autopsy at 3 and 10 days post-injection assessing iron content in critical brain regions.

RESULTS

The ID mice showed marked circadian variation in NTB extracellular iron. After iron injection, NTB iron was rapidly increased in the VMB and then decreased over 12h to the levels observed for vehicle. Regional brain iron content at 3 and 10 days post-injection in the iron- compared to vehicle-treated group showed significantly more iron for the VMB and nucleus accumbens but not for the other regions (i.e. prefrontal cortex, caudate-putamen, cerebellum, and pons), which also did not show decreased iron content with the ID diet.

CONCLUSION

Iron isomaltoside-1000 given IV corrects the regional brain iron deficiency in these ID mice without producing iron overload in any of the brain regions studied. This is the first demonstration of effects of IV iron in the brain and it provides a useful preclinical model for this assessment, particularly relevant for developing iron treatments for conditions with problematic iron deficiency, e.g. RLS.

Brain malformation in single median maxillary central incisor

Clinical and radiographic examinations and MR scan of a 12-year-old girl with SMMCI (single median maxillary central incisor) showed impaired growth and a midline defect involving the central incisor, cranium and the midline structures in the brain, falx cerebri and pituitary gland. She had a severe growth hormone deficiency but no other pituitary hormone deficiencies. She was treated with growth hormone and followed during a four-year period with successful gain in body height and sexual maturation. This study focuses on the developmental association between the involved structures and provides guidelines for early diagnostics.

Delayed Migraine-Like Headache in Healthy Volunteers After a Combination of Acetazolamide and Glyceryl Trinitrate

Glyceryl trinitrate (GTN) is a pro-drug dissociating nitric oxide throughout the body. It dilates cephalic arteries without increasing cerebral blood flow (CBF). GTN induces headache in healthy volunteers and migraine attacks in migraineurs. Acetazolamide (Az) increases CBF but does not dilate cerebral arteries. The hypothesis tested here was that Az, by dilating cerebral arterioles but not arteries and thereby decreasing pulsatile stretching of the wall of the large arteries and their perivascular sensory nerves, would reduce or prevent the GTN-induced headache We tested this hypothesis in 14 healthy volunteers. In a randomized, double-blind, cross-over study, they were pretreated with Az or placebo followed on both study days by a GTN infusion of 0.5 μg kg-1 min-1 for 20 min. Headache was scored on a verbal rating scale and a headache diary was kept for 12 h. Mean blood velocity of the middle cerebral artery was measured (transcranial Doppler). Our hypothesis was disproved, as Az did not decrease GTN-induced headache. Unexpectedly but interestingly, GTN combined with Az induced more delayed headache than GTN alone. Furthermore, a migraine-like headache was observed in three volunteers, who did not develop migraine after GTN alone. The fact that a suitable pharmacological intervention may trigger migraine in individuals with no prior migraine may suggest that the ability to develop migraine without aura is a quantitative genetic trait.

Screen for CACNA1A and ATP1A2 mutations in sporadic hemiplegic migraine patients

The aim of this study was to investigate the involvement of the CACNA1A and ATP1A2 gene in a population-based sample of sporadic hemiplegic migraine (SHM). Patients with SHM (n = 105) were identified in a nationwide search in the Danish population. We sequenced all exons and promoter regions of the CACNA1A and ATP1A2 genes in 100 patients with SHM to search for possible SHM mutations. Novel DNA variants were discovered in eight SHM patients, four in exons of the CACNA1A gene and four in exons of the ATP1A2 gene. Six of the variants were considered non-pathogenic. The causal role of the two remaining DNA variants is unknown until functional studies have been made or independent genetic evidence is discovered. Only very few DNA variants were identified in 100 SHM patients, and regardless of whether the identified variants are causal the CACNA1A and ATP1A2 genes are not major genes in SHM.

Familial hemiplegic migraine type 1 shows no hypersensitivity to nitric oxide

Familial hemiplegic migraine type 1 (FHM-1) is a dominantly inherited subtype of migraine with aura and transient hemiplegia associated with mutations in the CACNA1A gene. FHM-1 shares many phenotypical similarities with common types of migraine, indicating common neurobiological pathways. Experimental studies have established that activation of the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway plays a crucial role in migraine pathophysiology. Therefore, we tested the hypothesis that CACNA1A mutations in patients with FHM-1 are associated with hypersensitivity to NO-cGMP pathway. We included eight FHM-1 patients with R583Q and C1369Y mutations and nine healthy controls, who received intravenous infusions of 0.5 microg kg(-1) min(-1) glyceryl trinitrate (GTN) over 20 min. We recorded: headache intensity on a verbal rating scale; mean flow velocity in the middle cerebral artery (V(meanMCA)) by transcranial Doppler; diameter of the superficial temporal artery (STA) by Dermascan. One patient reported migraine without aura 5 h after start of the GTN infusion. No aura was reported. The AUC(headache) in the immediate phase was more pronounced in patients than in controls (P = 0.01). In the 14 h following GTN infusion, there was no difference in the AUC(headache) between patients and controls (P = 0.17). We found no difference in the AUC(VmeanMCA) (P = 0.12) or AUC(STA) (P = 0.71) between FHM-1 patients and controls. None of the control persons reported migraine-like headache. FHM-1 patients do not show hypersensitivity of the NO-cGMP pathway, as characteristically seen in migraine patients with and without aura. This indicates that the pathophysiological pathways underlying migraine headache in FHM-1 may be different from the common types of migraine.

Familial hemiplegic migraine type 2 does not share hypersensitivity to nitric oxide with common types of migraine

Familial hemiplegic migraine type 2 (FHM-2) and common types of migraine show phenotypic similarities which may indicate a common neurobiological background. The nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway plays a crucial role in migraine pathophysiology. Therefore, we tested the hypothesis that ATP1A2 mutations in patients with FHM-2 are associated with hypersensitivity to NO-cGMP pathway. Eight FHM-2 patients with R202Q, R763C, V138A and L764P mutations and nine healthy controls received intravenous infusions of 0.5 mug kg(-1) min(-1) glyceryl trinitrate (GTN) over 20 min. We recorded the following variables: headache intensity on a verbal rating scale; mean flow velocity in the middle cerebral artery (V(meanMCA)) by transcranial Doppler; diameter of the superficial temporal artery (STA) by ultrasound. The primary end-points were differences in incidence of migraine headache and area under the curve (AUC) for headache score during an immediate phase (0-120 min) and a delayed phase (2-14 h) after start of infusion. We found no difference in the incidence of reported migraine between FHM-2 patients, 25% (two out of eight), and controls, 0% (0 out of nine) (95% confidence interval -0.06, 0.56) (P = 0.21). The AUC(headache) in the immediate (P = 0.37) and delayed (P = 0.09) phase was not different between patients and controls. The GTN infusion resulted in a biphasic response in patients. During the immediate phase, the median peak headache occurred at 30 min and tended to be higher in patients, 1 (0, 3.8), than in controls, 0 (0, 1) (P = 0.056). During the delayed phase, the median peak headache occurred 4 h after the start of the infusion and was significantly higher in patients, 2.5 (0, 3), than in controls, 0 (0, 0) (P = 0.046). We found no difference in the AUC(VmeanMCA) (P = 0.77) or AUC(STA) (P = 0.53) between FHM-2 patients and controls. GTN infusion failed to induce more migraine in FHM-2 patients than in controls. The pathophysiological pathways underlying migraine headache in FHM-2 may be different from the common types of migraine.

The genetic spectrum of a population-based sample of familial hemiplegic migraine

Familial hemiplegic migraine (FHM) is a rare subtype of migraine with aura and transient hemiplegia. FHM mutations are known in three genes, the CACNA1A (FHM1) gene, the ATP1A2 (FHM2) and the SCN1A (FHM3) gene and seem to have an autosomal-dominant mode of inheritance. The aim of this study was to search for FHM mutations in FHM families identified through a screen of the Danish population of 5.2 million people. FHM patients were diagnosed according to the International Classification of Headache Disorders and all FHM patients had a physical and neurological examination by a physician. A total of 147 FHM patients from 44 different families were identified; 43 FHM families participated in this study. Linkage analysis of these families shows clear linkage to the FHM locus (FHM1) on chromosome 19, supportive linkage to the FHM2 locus whereas no linkage was found to the FHM3 locus. Furthermore, we sequenced all exons and promoter regions of the CACNA1A and ATP1A2 genes and screened for the Q1489K mutation in the SCN1A gene. CACNA1A gene mutations were identified in three of the FHM families, two known FHM mutations, R583Q and T666M and one novel C1369Y mutation. Three FHM families were identified with novel mutations in the ATP1A2 gene; a family with a V138A mutation, a family with a R202Q mutation and a family with a R763C mutation. None of the Danish FHM families have the Q1489K mutation in the SCN1A gene. Our study shows that only 14% (6/42) of FHM families in the general Danish population have exonic FHM mutations in the CACNA1A or ATP1A2 gene. The families we identified with FHM mutations in the CACNA1A and ATP1A2 genes were extended, multiple affected families whereas the remaining FHM families were smaller. The existence of many small families in the Danish FHM cohort may reflect less bias in FHM family ascertainment and/or more locus heterogeneity than described previously.

The Visual Aura Rating Scale (VARS) for migraine aura diagnosis

To supplement the traditional ICHD-2 diagnosis for migraine with aura (MA) we developed a diagnostic scale for migraine aura that quantifies the importance of the cardinal characteristics of MA. Since more than 99% of MA patients have visual aura, we developed for simplicity a Visual Aura Rating Scale (VARS). In total 427 patients with MA (ICHD-2) or nonaura visual disturbances were diagnosed in a validated semistructured interview by a trained physician. The patients were separated into a derivation sample and a validation sample. By regression analysis we identified the visual aura characteristics associated with MA in the derivation sample. Based on the identified characteristics we developed VARS and derived a predictive VARS score which was tested in the validation sample. The VARS score is the weighted sum of the presence of five visual symptom characteristics: duration 5-60 min (3 points), develops gradually > or = 5 min (2 points), scotoma (2 points), zig-zag lines (2 points), and unilateral (1 point). The maximum score is 10 points. A VARS score of 5 or more diagnosed MA with a sensitivity of 96% (95% CI 92-99%) and a specificity of 98%(95% CI 95-100%) in the derivation sample, and a sensitivity of 91% (95% CI 86-95%) and a specificity of 96% (95% CI 91-100%) in the validation sample. VARS adds evidence based weights to a number of clearly specified characteristics; it is easy to learn, apply and teach and may therefore be a valuable addition to traditional ICHD-2 diagnosis.

Peroperative depth of anaesthesia may influence postoperative opioid requirements

BACKGROUND

Studies on monitoring the depth of anaesthesia have shown that with the use of these monitors the peroperative consumption of anaesthetics can be reduced. Studies have also indicated that the peroperative depth of anaesthesia may affect the postoperative course. The purpose of this study was to evaluate a possible relation between the depths of anaesthesia and the postoperative pain score and consumption of morphine.

METHODS

We used middle latency auditory evoked potentials (MLAEPs) for monitoring the depth of anaesthesia. The study was prospective, observer blinded and included 50 women scheduled for elective abdominal hysterectomy. Anaesthesia was induced using propofol and remifentanil. Before leaving the recovery room the patients were provided with a programmed patient-controlled pump (PCA), which was only activated on demand. Auditory evoked potentials were registered from just before induction of anaesthesia and during the whole procedure, but the anaesthetist did not have access to the monitor.

RESULTS

Fifty patients were included and seven were excluded. The remaining 43 patients were divided into two groups: Group High (n=12) with an AAI>28 for >5% of the registration time and Group Low (n=31) with an AAI>28 for <5% of the registration time. Group High had significantly higher morphine requirements in the recovery and activated the PCA-pump more frequently during the first 24 postoperative hours.

CONCLUSION

The results indicate that the peroperative depth of anaesthesia may have effects on the postoperative analgesic requirements.

Sensitivity and specificity of the new international diagnostic criteria for migraine with aura

OBJECTIVES

Since 1998, migraine with aura (MA) has been diagnosed according to the operational diagnostic criteria of the International Headache Society (ICHD-1). Here we present the data underlying the new criteria for MA in the ICHD-2 classification.

METHODS

Sensitivity of the new criteria was tested in patients with MA and specificity in patients with reversible non-aura visual disturbances. The diagnoses in both groups of patients were made in a validated semistructured physician-conducted interview. We tested five sets of criteria for sensitivity and specificity comparing with the diagnosis according to the ICHD-1 in 200 patients and the selected set of criteria in 274 additional patients.

RESULTS

Four sets of criteria had sensitivity/specificity of 46%/100%, 71%/100%, 62%/95%, and 99%/76%. Sensitivity of the selected set of criteria was 84% (95% CI 79% to 90%) and specificity 97% (95% CI 95% to 99%). According to these criteria at least two of the following should be fulfilled: homonymous visual or unilateral sensory symptoms; at least one aura symptom develops gradually over > or =5 minutes and/or different symptoms occur in succession over > or =5 minutes; each symptom lasts > or =5 and < or =60 minutes. In the additional sample sensitivity of the selected criteria was 90% (95% CI 86% to 94%) and specificity 96% (95% CI 91% to 100%).

CONCLUSIONS

The diagnostic criteria for MA selected for ICHD-2 had high sensitivity and specificity. The ICHD-2 criteria are more operational and probably delineate a more homogeneous sample of patients than the ICHD-1. The ICHD-2 for MA is intended equally for research and clinical practice and can be used at different levels of specialisation.

The prophylactic effect of valproate on glyceryltrinitrate induced migraine

In this study the human glyceryltrinitrate (GTN) model of migraine was for the first time used to test the effect of a prophylactic drug. We chose to test valproate due to its well documented effect as a migraine prophylactic drug. Efficacy of this compound would support the usefulness of the model in prophylactic antimigraine drug development. Twelve patients with migraine without aura were included in a randomized double blind crossover study. Valproate 1000 mg or placebo was given daily, each for a minimum of 13 days. On the last treatment day of each arm a 20 min intravenous infusion of GTN (0.25 microg/kg/min) was given. Headache was registered for 12 h after the infusion and headache intensity was scored on a scale from 0 to 10. Fulfillment of IHS criteria was recorded for 24 h. The middle cerebral arteries were evaluated by transcranial Doppler and the diameter of the superficial temporal and radial arteries were measured with high frequency ultrasound. GTN evoked migraine fulfilling IHS criteria 1.1 in 6 patients after placebo and in 2 patients after valproate (P = 0.125). Including additionally 3 patients on placebo and 1 patient on valproate who felt they had suffered a migraine attack, but who had as associated symptoms only photophobia or phonophobia, a significant reduction in the number of patients with induced migraine after valproate was seen (P = 0.031). Median peak headache intensity was 1 (range 0-9) after valproate compared to 4.5 (range 0-8) after placebo (P = 0.120). Pretreatment with valproate as compared to placebo reduced the velocity in both middle cerebral arteries after GTN (left P = 0.021, right P = 0.031). No effect of valproate was seen in the diameter of the superficial temporal artery (P = 0.781) or the radial artery (P = 0.367) before or after GTN. The study indicates that a prophylactic effect of valproate may be demonstrated using the GTN human migraine model. Although, all headache parameters were reduced after valproate compared to placebo, only one parameter was statistically significantly reduced probably because of the small number of patients. The size of the effect was similar to that of valproate in clinical trials. The GTN model may therefore be a valid tool for testing new prophylactic antimigraine drugs.

Plasma levels of cAMP, cGMP and CGRP in sildenafil-induced headache

Sildenafil, a selective inhibitor of the cyclic guanosine monophosphate (cGMP) degrading phosphodiestrase 5 (PDE5), induced migraine without aura in 10 of 12 migraine patients and in healthy subjects it induced significantly more headache than placebo. The aim of the present study was to determine whether the pain-inducing effects of sildenafil would be reflected in plasma levels of important signalling molecules in migraine: cGMP, cyclic adenosine monophosphate (cAMP) and calcitonin gene-related peptide (CGRP). Ten healthy subjects (four women, six men) and 12 patients (12 women) suffering from migraine without aura were included in two separate double-blind, placebo-controlled, cross-over studies in which placebo or sildenafil 100 mg was administered orally. Plasma levels of CGRP, cAMP and cGMP were determined in blood from the antecubital vein. Despite the ability of sildenafil to induce headache and migraine, no significant differences in plasma levels of CGRP, cGMP and cAMP were detected after sildenafil compared with placebo. In conclusion, plasma levels of CGRP, cGMP and cAMP remain normal during sildenafil-induced headache or migraine. However, since previous studies indicate an important role of these signalling molecules, the present study questions whether cAMP and cGMP in peripheral blood can be used for monitoring pathophysiological events in headache and migraine mechanisms.

New international classification of migraine with aura (ICHD-2) applied to 362 migraine patients

The International Classification of Headache Disorders 2nd edition (ICHD-2) subdivides migraine with aura (MA) differently from the ICHD-1 and includes new diagnostic criteria. The aim of the present study was to evaluate how the new classification works in practice and in comparison with the ICHD-1. The patients were recruited from a screen of the Danish National Patient Registry and from Danish neurologists. We included 362 patients diagnosed with MA according to the ICHD-1 in a validated semistructured physician-conducted interview. According to the ICHD-2, 89% (322 of 362) had MA and 11% (40 of 362) had probable MA. The MA patients had one or more ICHD-2 subtype of MA: 54% (173 of 322) had typical aura with migraine headache (MA-MH), 40% (129 of 322) had typical aura with non-migraine headache (MA-NMH), 37% (120 of 322) had aura without headache (MA-WOH), and 7% (26 of 322) had basilar-type migraine (MA-B). Of patients with MA-MH 34% (59 of 173) had co-occurrence of MA-WOH, 9% (16 of 173) had co-occurrence of MA-B and 5% (8 of 173) had co-occurrence of both MA-WOH and MA-B. Of patients with MA-NMH 27% (35 of 129) had co-occurrence of MA-WOH. Only 6% (18 of 322) of the MA patients had exclusively MA-WOH and <1% (2 of 322) had exclusively MA-B. Patients with MA-MH had an earlier age at onset (P = 0.044), an increased lifetime number of MA attacks (P = 0.054) and a higher co-occurrence of migraine without aura (P = 0.002) than patients with MA-NMH. Patients with MA-B tended to have an earlier age at onset and more severe attacks and patients with MA-WOH had a higher age at onset and less severe attacks than patients with MA-MH. The variations between ICHD-2 subtypes of MA indicate that patients with similar subtype of MA share phenotype and very likely have similar underlying aetiology.

Increased risk of migraine with typical aura in probands with familial hemiplegic migraine and their relatives

We investigated the occurrence of migraine without aura (MO) and migraine with typical aura (MA) amongst probands with familial hemiplegic migraine (FHM) and their first degree relatives in order to evaluate the relations between these syndromes. A total of 44 FHM probands and 240 first degree relatives were identified in the Danish population. The pattern of familial aggregation was assessed by population relative risk (PRR) calculations. Amongst FHM probands the PRR of MO was 1.5 (95% CI: 0.8-2.2), whereas the PRR of MA was 7.1 (95% CI: 5.0-9.2). Thus, compared with the general population, FHM probands had no increased risk of MO but a significantly increased risk of MA. A similar pattern was seen amongst their first degree relatives, who had no increased risk of MO, whereas the risk of MA was significantly increased; 7.6 times in FHM-affected first degree relatives and 2.4-times in non-FHM-affected first degree relatives. These results are contrary to a sharing of genetic mechanisms between FHM and MO. Furthermore, they suggest that the genetic abnormality causing FHM may also cause attacks with the symptomatology of MA.

Early detection of tumour immune-rejection using magnetic resonance imaging

Dynamic contrast agent-enhanced magnetic resonance imaging measurements of the perfusion of an immunogenic murine tumour showed that immune rejection was preceded by an increase in the apparent vascular volume of the tumour. This increase in vascularity, which has been observed previously in other tumours undergoing immune rejection, was confirmed by histological analysis of tumour sections obtained postmortem. Magnetic resonance imaging measurements similar to this could be used in the clinic to monitor the early responses of tumours to immunotherapy, before there is any change in tumour growth rate or volume.

A population-based study of familial hemiplegic migraine suggests revised diagnostic criteria

Familial hemiplegic migraine (FHM) is a rare autosomal dominantly inherited subtype of migraine with aura. The clinical characteristics of FHM have been described previously in selected materials or case studies, but population-based studies are important in order to analyse the full spectrum of the disorder. The aim of the present study was to perform a systematic search for familial cases of migraine with an aura that included motor weakness in order to generate non-selected material of as many FHM cases as possible in the Danish population of 5.2 million inhabitants, and to compare this material with already available population-based clinical descriptions of migraine with typical aura (MA). Due to the rarity of FHM, traditional population-based methods were not feasible. Therefore, the search strategy employed a computer search of the National Patient Register, screening >27 000 case records from headache clinics and private neurologists, and advertisements. A total of 147 affected FHM patients from 44 families were identified. FHM patients most often had all four 'typical' aura symptoms (visual, sensory, aphasic and motor symptoms) and all had at least two of these aura symptoms during FHM attacks. The motor, sensory and visual aura symptoms were all similar in type to the motor, sensory and visual aura symptoms in MA, but FHM had a statistically significantly longer duration of the visual and sensory aura symptoms, and these and other aura symptoms often fulfilled the criteria of the International Headache Society for prolonged aura. In addition, 69% had basilar migraine (BM) symptoms during FHM attacks. The order of the aura symptoms was usually visual, followed by sensory, aphasic, motor and, lastly, basilar-type migraine symptoms. Headache was present in 99% of FHM patients during FHM attacks, whereas the aura symptoms more often occurred without headache in MA. Headache duration was significantly longer in FHM compared with MA. Based on these data, we suggest more precise diagnostic criteria for FHM and a more clear clinical distinction between FHM and BM. Our results have significant implications for case finding in genetic studies and for clinical migraine differential diagnosis.

[Molecular genetic findings in migraine]

This review focuses on the different molecular genetic findings in migraine. Familial hemiplegic migraine (FHM) is a rare subtype of migraine with aura, which is inherited as an autosomal dominant. Half the cases of FHM are caused by point mutations in the CACNA1A gene on the short arm of chromosome 19 (19p). The gene encodes a calcium ion channel. Other mutation types cause episodic ataxia 2 (EA-2). Expansions of the CAG repeat in the 3' end bring about spinocerebellar ataxia 6 (SCA 6). Some families with FHM link to loci on the long arm of chromosome 1 (1q). The genes have not yet been identified. Some families neither link to 1q nor to 19p. Population-based family and twin studies have shown that migraine both with and without aura have a multifactorial inheritance. The CACNA1A gene may be of importance for ordinary forms of migraine in a few families. Mutations in genes on the X chromosome, dopamine receptor genes, and the ACE gene appear to be involved in migraine in a few families, whereas genes for nitric oxide synthase, serotonin receptors, and mitochondrial DNA do not seem to be involved. The positive associations have not been reproduced in other studies and therefore they should be interpreted with care. It is to be hoped that in the next few years much more will be known about the molecular genetic mechanisms of migraine with and without aura. FHM is an ion channel disorder, and many factors suggest that migraine is also an ion channel disorder, which is consistent with the paroxysmal nature of the illness.

Nitric oxide in primary headaches

The molecular mechanisms that underlie the primary headaches-migraine, cluster headache and tension-type headache-have not yet been clarified. On the basis of studies in headache induced by intravenous infusions of glyceryl trinitrate (an exogenous nitric oxide donor) and histamine (which liberates nitric oxide from vascular endothelium), it has been suggested that nitric oxide is a likely candidate responsible molecule. The present review deals with the biology of this small messenger molecule, and the updated scientific evidence that suggests a key role for this molecule in primary headaches. This evidence suggests that the release of nitric oxide from blood vessels, perivascular nerve endings or from brain tissue is an important molecular trigger mechanism in spontaneous headache pain. Pilot trials have shown efficacy of a nitric oxide synthase inhibitor in both migraine attacks and chronic tension-type headache. These observations suggest new approaches to the pharmacological treatment of headache.

Early commitment of adoptively transferred CD4+ T cells following particle-mediated DNA vaccination: implications for the study of immunomodulation

The early responses of CD4+ T cells to particle-mediated DNA immunisation were investigated using OVA-specific TCR-transgenic CD4+ T cells. Following adoptive transfer of these cells, mice were immunised by delivery into the skin of a plasmid encoding ovalbumin. Transgenic T cells underwent a rapid and transient antigen-specific activation, followed by clonal expansion (up to approximately 6% of total lymphocytes). Immunisation with ovalbumin in CFA evoked similar responses with slightly faster kinetics. Numerous antigen-specific T cells synthesising IFN-gamma (Th1) and IL-4 (Th2) were detectable using both intracellular staining and ELISPOT assays. This study provides a quantitative analysis of both T cell proliferation and Th1/Th2 balance following particle-mediated DNA immunisation and establishes a robust and sensitive model in which to assess modulation of helper T cell responses in DNA vaccination.

[Prednisolone treatment of respiratory syncytial virus infection. A randomized, controlled trial of 147 children]

OBJECTS

Our objective was to evaluate the effect of systemic prednisolone as an adjunct to conventional treatment with beta 2-agonist, fluid replacement and respiratory support in hospitalized infants younger than 24 months with respiratory syncytial virus (RSV) infection.

METHODS

The study was randomized, double-blind and placebo-controlled. During the winter of 1995-96, 147 infants less than two years of age hospitalized with RSV infection were allocated to treatment with either systemic prednisolone mixture 2 mg/kg daily or placebo for 5 days.

RESULTS

Our main outcome measures were: 1. Acute effect variables: duration of stay in hospital, use of medicine and supportive measures while in hospital. 2. At follow-up one month after discharge: duration of illness, start in day care center, morbidity and use of medicine. 3. At follow-up one year after discharge: morbidity, use of medicine and skin prick tests with allergens.

CONCLUSION

Prednisolone treatment had no effect on any of the outcome measures. We find our results in agreement with the largest studies reported earlier; therefore, corticosteroid, whether by systemic route or by inhalation, should not be prescribed to infants with RSV infection.

Effects of the non-selective phosphodiesterase inhibitor pentoxifylline on regional cerebral blood flow and large arteries in healthy subjects

The vasodilating properties of the non-selective phosphodiesterase (PDE) inhibitor pentoxifylline were evaluated. Pentoxifylline has been reported to increase cerebral blood flow (CBF) and improve recovery rate of stroke patients. Whether these results are due to a dilating effect on arteries or to other mechanisms is not clear. In the present double-blind crossover study, 10 healthy subjects received pentoxifylline 300 mg or placebo intravenously on separate days. Blood flow velocity in the middle cerebral artery (V(mca)) was recorded by transcranial Doppler and rCBF was measured using (133)Xenon-inhalation SPECT. High-frequency ultrasound was used for measurements of temporal and radial artery diameter. Cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP) concentrations were assessed in plasma. Except for increased heart rate (P < 0.05), systolic blood pressure (P < 0.05) and plasma cAMP (P < 0.001), no significant differences in CBF, rCBF(mca) or plasma cGMP were seen between placebo and pentoxifylline infusion. During pentoxifylline infusion, V(mca) decreased 7.2% (SD 12.0; P < 0.05) and temporal artery diameter increased 9.0% (SD 7.0; P < 0.001), suggesting minor dilatation of the large arteries. However, this change was not significantly different from placebo. In conclusion, pentoxifylline 300 mg had no effect on rCBF. A possible minor dilatation of the middle cerebral artery and the temporal artery cannot be excluded. Any potential clinical effect of pentoxifylline is most likely mediated through non-vascular mechanisms.

Dipyridamole dilates large cerebral arteries concomitant to headache induction in healthy subjects

Dipyridamole is used for secondary prophylaxis in ischemic stroke and as a vasodilator agent in myocardial scintigraphy. An important side effect to administering dipyridamole is headache. The aim of the current study was to investigate the effects of dipyridamole on cerebral blood flow, large artery diameter, and headache induction. Twelve healthy subjects were included in this single-blind placebo-controlled study in which placebo (0.9% NaCl) and dipyridamole 0.142 mg/kg x min were administered intravenously over 4 minutes 1 hour apart. Blood flow velocity in the middle cerebral artery (Vmax) was recorded by transcranial Doppler and regional cerebral blood flow in the middle cerebral artery (rCBFmca) was measured using single photon emission computed tomography and 133Xenon-inhalation. Blood pressure, heart rate, and pCO2 were measured repeatedly. Headache response was scored every 10 minutes on a verbal scale from 0 to 10 (10 = worst). Dipyridamole caused a decrease in pCO2 (P < 0.001). pCO2 corrected rCBFmca was 41.7 +/- 6.9 mL/100 g x min after placebo versus 41.2 +/- 6.9 after dipyridamole (P > or = 0.05). pCO2 corrected Vmca decreased 8.4% +/- 11.7 (P < 0.001) after dipyridamole, indicating a mean 5.6% +/- 6.7 (P = 0.005) relative increase of the arterial diameter. After dipyridamole the median peak headache score was 2 (range 0 to 7) compared with 0 (range 0 to 3) after placebo (P = 0.02). Dilatation of the middle cerebral artery outlasted the headache response. In conclusion, dipyridamole causes a modest pCO2 independent dilatation of the MCA, which is time-linked to the onset, but not to the cessation, of headache.

Prednisolone treatment of respiratory syncytial virus infection: a randomized controlled trial of 147 infants

OBJECTIVE

To evaluate the effect of systemic prednisolone as an adjunct to conventional treatment with beta2-agonist, respiratory support, and fluid replacement in hospitalized infants <24 months of age with respiratory syncytial virus (RSV) infection.

METHODS

The study was randomized, double-blind, and placebo-controlled. During the winter of 1995-1996, 147 infants <2 years of age, hospitalized with RSV infection, were allocated to treatment with either systemic prednisolone mixture 2 mg/kg daily or placebo for 5 days.

MAIN OUTCOME MEASURES

The acute effect variables were duration of stay in hospital, use of medicine, and supportive measures while in hospital. At follow-up 1 month after discharge, the acute effect variables were duration of illness, start in day care center, morbidity, and use of medicine. At follow-up 1 year after discharge, the acute effect variables were morbidity, use of medicine, and skin prick tests with allergens.

RESULTS

Prednisolone treatment had no effect on any of the outcome measures.

CONCLUSIONS

Our randomized prospective study in infants hospitalized with acute RSV infection showed no effect of systemic prednisolone treatment either in the acute state of RSV infection, nor in the follow-up 1 month and 1 year after admission to hospital. We find our results in agreement with the largest studies reported earlier; therefore, corticosteroid, whether by the systemic route or by inhalation, should not be prescribed to infants with RSV infection.

Glyceryl trinitrate induces attacks of migraine without aura in sufferers of migraine with aura

Migraine with aura and migraine without aura have the same pain phase, thus indicating that migraine with aura and migraine without aura share a common pathway of nociception. In recent years, increasing evidence has suggested that the messenger molecule nitric oxide (NO) is involved in pain mechanisms of migraine without aura. In order to clarify whether the same is true for migraine with aura, in the present study we examined the headache response to intravenous infusion of glyceryl trinitrate (GTN) (0.5 microg/kg/min for 20 min) in 12 sufferers of migraine with aura. The specific aim was to elucidate whether an aura and/or an attack of migraine without aura could be induced. Fourteen healthy subjects served as controls. Aura symptoms were not elicited in any subject. Headache was more severe in migraineurs than in the controls during and immediately after GTN infusion (p=0.037) as well as during the following 11 h (p = 0.008). In the controls, the GTN-induced headache gradually disappeared, whereas in migraineurs peak headache intensity occurred at a mean time of 240 min post-infusion. At this time the induced headache in 6 of 12 migraineurs fulfilled the diagnostic criteria for migraine without aura of the International Headache Society. The results therefore suggest that NO is involved in the pain mechanisms of migraine with aura. Since cortical spreading depression has been shown to liberate NO in animals, this finding may help our understanding of the coupling between cortical spreading depression and headache in migraine with aura.

Treatment with ciprofloxacin in children with typhoid fever

We investigated the use, treatment results and safety of ciprofloxacin in the treatment of childhood typhoid and paratyphoid infections in an industrialized country. The study was retrospective, and the material consisted of children admitted to Hvidovre or Glostrup University Hospitals from 1991 to 1995, and treated with ciprofloxacin for a culture proven diagnosis of typhoid fever. 21 children were included, 18 had positive cultures for Salmonella typhi and 3 had positive cultures for S. paratyphi A. All isolates were fully susceptible to ciprofloxacin. The median duration of treatment was 10 d, median oral dose was 24 mg/kg/d and the median intravenous dose was 15 mg/kg/d. Within 4 d after start of treatment all subjects had a normal body temperature. No subjects had clinical or microbiological relapse and all stool cultures after end of treatment were negative. Adverse events were rare, but in 2 children a transient limb/ataxia or a period of confusion were recorded. Both children recovered within a few days without sequelae. We conclude that ciprofloxacin was effective and well tolerated for treatment of typhoid fever in children. The few adverse events that were recorded left no permanent sequelae, and were likely to be caused by the disease itself.

Nitric oxide synthase activity in fresh cells from ovarian tumour tissue: relationship of enzyme activity with clinical parameters of patients with ovarian cancer

Recent studies suggest a dual role for nitric oxide (NO) in tumour biology. High concentrations of NO can mediate tumouricidal activity, whereas lower concentrations have been shown to promote tumour growth. In this study, NO synthase (NOS) activity was investigated in cells that were prepared from tissue from primary and metastatic sites and from malignant effusions in 41 cases of suspected ovarian cancer. NO biosynthesis, determined by nitrite + nitrate (NOx) accumulation in medium from cultured cells prepared from disaggregated tumours or effusions and indicative of the inducible NO synthase isoform, was detected in 37% of the cases investigated (range 10.2-114 microM). There was a significant relationship between NOx and tumour differentiation (P = 0.014), with NOx being significantly higher for the more differentiated tumours. NOS activity, determined by the conversion of radiolabelled L-arginine to citrulline by tissue or cell extracts, was detected in 29% of cases (range 0.9-6.9 pmol/min per mg of protein), with all samples tested being moderately or poorly differentiated. Seventy percent of this activity was calcium dependent, indicative of constitutive NOS isoforms. Morphological and immunohistochemical assessment of tumour samples indicated a significant relationship between high macrophage content and NOS activity (as NOx biosynthesis) (rs = 0.726, N = 16, P < 0.01). The relationship between NOS expression, immune response, and disease progression is complex and not simply dependent on the differentiation status of ovarian cancer.

[Familial hemiplegic migraine]

Familial hemiplegic migraine (FHM) is a rare subtype of migraine with aura. It is inherited as an autosomal dominant trait. A gene for FHM has been assigned to chromosome 19. This gene codes for a brain-specific calcium channel, and is responsible for FHM in 55% of the FHM families. Other FHM families have been linked to two different locations on chromosome 1. These locations contain possible candidate genes coding for calcium-and potassium channels. Thus FHM is a genetically heterogenous ion channel disorder, which is caused by at least three different genes. About 29% of the FHM families also have cerebellar ataxia, these families have all been linked to chromosome 19. The identification of the genes for FHM may be a key to the identification of the gene/genes for migraine with and without aura.

No relation between cephalic venous dilatation and pain in migraine

Evidence for the involvement of the cranial arterial system in migraine is plentiful, but it is unclear whether the cranial venous system may be involved in the mechanism of migraine pain. Venules are the preferentially involved vessels in the neurogenic inflammation animal model of migraine. The cranial and cerebral veins and sinuses are pain sensitive and receive sensory innervation from the trigeminal nerve. If the veins are involved in migraine pathogenesis, a venous dilatation would presumably be painful. The effect of a short lasting cranial venous dilatation, induced by applying pressure on the internal jugular veins (Queckenstedt's manoeuvre), was therefore compared with a placebo procedure, consisting of an equal pressure applied on to the lateral aspect of the neck. In each procedure pressure was applied for 10 seconds. The study used a single blind, randomised, cross over design, and 20 patients with an acute attack of migraine without aura participated. After each procedure, headache intensity was rated on a standardised five point scale. After Queckenstedt's manoeuvre 40% of the patients reported no change in headache intensity, 25% a worsening, and 35% an improvement of their headache. No significant difference between the headache intensity ratings during Queckenstedt's manoeuvre and the placebo manoeuvre was found (p=0.22). The findings make it unlikely that the cephalic venous system is of major importance in migraine pain mechanisms and, therefore, also less likely that neurogenic inflammation plays a significant part in humans during attacks of migraine without aura.

Nitric oxide theory of migraine

The molecular mechanisms of migraine pain have not yet been clarified. Neurogenic inflammation and a subsequent plasma extravasation in the dura mater have been suggested. However, monoamine and peptide neurotransmitters involved in neurogenic inflammation do not cause significant head pain. Based on our previous studies of headache induced by i.v.infusions of glyceryl trinitrate (exogenous nitric oxide donor) and histamine (which liberates nitric oxide from vascular endothelium), we suggest that nitric oxide (NO) is a more likely candidate molecule. The present review deals with the biology of this small messenger molecule and the scientific evidence suggesting a key role for this molecule in migraine headache. We hypothesise that the release of NO from either blood vessels, perivascular nerve endings, or brain tissue is a molecule trigger mechanism of spontaneous migraine pain. These novel observations dictate new approaches to the pharmacological treatment of migraine.

Role of nitric oxide in tumour progression: lessons from human tumours

Varied cellular expression and localisation of nitric oxide synthase (NOS) isoforms has been shown in human cancers, including tumours of the breast, ovary, stomach, cervix and central nervous system. Mapping of NOS expression within tumour tissue from breast and gastric cancers shows inducible NOS (iNOS) is expressed predominantly in stromal (macrophage and endothelial) cells, although the level of NOS activity is at least 1-2 orders of magnitude lower than the enzyme activity associated with cytotoxicity and apoptosis. There is evidence that the intratumoural environment may provide chemoattractant signals for monocyte-macrophage recruitment and their subsequent activation via expression of interleukin-4, IgE, and CD23. Such signals lead to induction of iNOS in human macrophages in vitro. The correlation between NOS activity and grade for breast cancer suggests that NO may provide a positive growth signal within the tumour microenvironment. In vivo studies showing increased growth rate, vascular density and invasiveness of a human tumour cell line transfected to constitutively express iNOS support this. Furthermore, in vivo administration of a highly selective inhibitor of iNOS limited invasion and growth rate of iNOS transfected tumours and other murine tumours expressing this isoform. Inhibition of NO generation in the intratumoural microenvironment may prove a useful cancer therapy by preventing angiogenesis, invasion and metastasis.

Persistent induction of nitric oxide synthase in tumours from mice treated with the anti-tumour agent 5,6-dimethylxanthenone-4-acetic acid

An anti-tumour agent 5,6-dimethylxanthenone-4-acetic acid (5,6-MeXAA) induced nitric oxide synthase (NOS) in the tumour, spleen, thymus and small intestine, but not in the lung, liver, kidney, heart or skeletal muscle in B6D2F1 mice bearing subcutaneous colon 38 tumours. This pattern of induction is distinct from that caused by agents such as endotoxin, muramyl dipeptide or Corynebacterium parvum. The induction of NOS (iNOS) in the tumour was more persistent (maximal at 3 days) than in other tissues (maximal at 12 h). Immunohistochemical staining suggested that iNOS was located in macrophages and endothelial cells within and around the tumour. Treatment with 5,6-MeXAA also caused substantial increases in plasma nitrite and nitrate (NOx) concentrations that peaked at 8-12 h after 5,6-MeXAA. The increase in plasma NOx was prevented by a NOS inhibitor N-iminoethyl-L-ornithine (L-NIO), indicating that it was due to enhanced production of NO. Tumour-bearing mice were more responsive than controls to 5,6-MeXAA both in their plasma NOx increase and in their lower maximally tolerated dose. L-NIO was unable to prevent the complete tumour necrosis and regression caused by 5,6-MeXAA at a dose that substantially inhibited the increase of plasma NOx. In conclusion, the experimental anti-tumour agent 5,6-MeXAA induced NO synthesis in tumour-associated macrophages and in immunologically active tissues in parallel with its effects on tumour growth. The experiments with a non-selective NOS inhibitor L-NIO, however, suggest that NO is not a significant component in the mechanism of the anti-tumour action of 5,6-MeXAA in this particular model.

Investigations into the role of nitric oxide and the large intracranial arteries in migraine headache

Previous studies suggest that nitric oxide (NO) is involved in headaches induced by i.v. infusion of the vasodilator and NO donor glyceryl trinitrate (GTN) in healthy subjects. Extending these studies to sufferers of migraine without aura, it was found that migraineurs experienced a stronger headache than non-migraineurs. In addition, most migraineurs experienced a delayed migraine attack at variable times (mean 5.5 h) after GTN provocation. This biphasic headache response in migraineurs may be linked to hypersensitivity in the NO-cGMP pathway. Thus, compared to controls, migraineurs were found to be more sensitive to GTN-induced intracranial arterial dilatation, which is known to be mediated via liberation of NO and subsequent synthesis of cGMP Furthermore, histamine infusions in migraineurs induced headache responses and intracranial arterial responses resembling those induced by GTN in migraineurs. Histamine is known to liberate NO from the endothelium via stimulation of the H1 receptor, which is present in the large intracranial arteries in man. Because both immediate histamine-induced headache and intracranial arterial dilatation and delayed histamine-induced migraine are blocked by H1-receptor blockade, a likely common pathway for GTN and histamine-induced headaches/migraines and intracranial arterial responses may be via activation of the NO-cGMP pathway. The delay in the development of these experimental migraines may reflect activation of multiple physiological processes. The intracranial arteries of migraineurs were found supersensitive to the vasodilating effect of GTN (exogenous NO). This relates to clinical findings suggesting dilatation of the large intracranial arteries on the headache side during spontaneous migraine attacks. The function of arterial regulatory mechanisms involving NO in migraine was therefore studied. In peripheral arteries, no endothelial dysfunction of NO was found and cardiovascular and intracranial arterial sympathetic function was normal. A mild parasympathetic dysfunction may be involved and may, via denervation supersensitivity, be responsible for the observed supersensitivity to NO. Another possibility is that NO initiates a perivascular neurogenic inflammation with liberation of vasoactive peptides. NO also mediates a variety of other physiological phenomena. One of these, the pain-modulating effect observed in animals, was evaluated in a human study using GTN infusion and measurements of pain thresholds. No definite effects of GTN were demonstrated. The precise mechanisms involved in NO-triggered migraines and which part of the NO-activated cascade that is involved remain to be determined. The possibilities for pharmacological stimulation and/or inhibition of several steps of the NO-activated cascade increase rapidly and soon may be available for human studies.

The localization of the insulin-like growth factor receptor 1 (IGFR-1) in benign and malignant breast tissue

Insulin-like growth factors (IGFs) play an important role in normal cellular growth and development and have been implicated in the regulation of tumour growth. Two receptors are recognized, IGFR-1 and IGFR-2, of which one, IGFR-1, is a transmembrane heterodimer structurally similar to the insulin receptor. Studies using ligand-binding assays have suggested that the proportion of human breast carcinomas expressing IGFR-1 varies between 39 and 93 per cent and all suggest a lower level of IGFR-1 expression in benign mammary epithelia. As there is this variation between studies and since no study appears to have examined the immunohistochemical localization of IGFR-1 within breast tissue, a series of 79 infiltrating ductal carcinomas, 11 infiltrating lobular carcinomas, three cases of pure ductal carcinoma in situ (DCIS), seven fibroadenomas, and eight normal breast specimens have been studied utilizing the monoclonal antibody alpha IR3. IGFR-1 localized to the epithelial component of 90 per cent of the carcinomas, with only cytoplasmic (21 per cent), only membrane (5 per cent), or a mixture of both cytoplasmic and membrane (64 per cent) staining patterns. In some tumours, distinct basolateral distribution of the receptor was observed. Invasive lobular carcinoma showed significantly less labelling than ductal (P = 0.0009). There was a significant correlation between the level of IGFR-1 immunostaining with both oestrogen receptor (P < 0.001) and progesterone receptor (P = 0.0018) positivity within the malignant group. All normal mammary epithelium showed strong labelling, which was often at an intensity matching that of the most strongly labelled carcinoma and occasionally visualized as basolateral staining of the luminal cells. Weak to moderate staining of endothelial cells was also observed. It is concluded that IGFR-1 immunoreactivity is found in the majority of breast carcinomas, where it correlates most closely with oestrogen receptor status. The high intensity labelling of normal cells seen in this study contrasts with the low levels inferred from ligand-binding-based techniques and emphasizes the importance of the morphological approach in the investigation of novel molecules.