Influence of COX-inhibiting analgesics on the platelet function of patients with subarachnoid hemorrhage.

BACKGROUND: Platelet function of patients with subarachnoid hemorrhage (SAH) may play an important part in both rebleeding and delayed cerebral ischemia, but little is known about aggregation pathways during the acute phase of stroke. Analgesics are used regularly in the first days after bleeding, and some can potentially inhibit the cyclooxygenase (COX) enzyme. We examined the platelet function of patients with SAH in order to describe their basal situation and determine whether the administration of intravenous nonsteroidal antiinflammatory drugs (NSAIDs) affected platelet aggregation. METHODS: Arachidonic acid (AA)-induced aggregation and the platelet function analyzer (PFA)-100 test with collagen/epinephrine cartridges were used to study a group of SAH patients that was treated with dexketoprofen and dipyrone and to compare them to patients that had received no analgesia. RESULTS: Ninety-six consecutive SAH patients prospectively enrolled in platelet studies. Twenty-seven patients were taking NSAIDs (10 on dexketoprofen and 17 on dipyrone), and there were 15 cases in the control group. AA-induced aggregation was 10% ± 3.2% for NSAIDs (mean ± standard error), specifically 17.2% ± 7% for dexketoprofen and 5.7% ± 1% for dipyrone. Aggregation in the control group was 72.4% ± 6% (P = .001). Both analgesics slowed the platelet plug formation during the PFA-100 test, with closure times of 237.2 ± 25 seconds for dexketoprofen and 198.4 ± 22 seconds for dipyrone and 138.1 ± 21 seconds in controls (P = .02). CONCLUSIONS: The administration of COX-inhibiting analgesics leads to an hypoaggregability state in the first days of SAH. Further insight into their impact on complications such as rebleeding and delayed cerebral ischemia is needed in order to optimize the headache treatment of SAH.

Headache and neuropsychic disorders in the puerperium: a case report with suspected deficiency of urea cycle enzymes.

An enzymatic abnormality of the urea cycle is a metabolic disorder occasionally seen in adults, but particularly in the puerperium. The main risk is acute hyperammoniemic encephalopathy, leading to psychosis, coma and even death if not diagnosed promptly and treated appropriately. Headache is frequent in the puerperium normally manifesting between 3 and 6 days after delivery. We describe here a 39-year-old woman, who 3 days after delivery presented diffuse tension-type headache and depression, followed by behavioral disorders, psychomotor agitation, epileptic seizures, and finally coma 2 days later. Pregnancy and normal delivery: routine blood chemistry findings, CT scan, MR imaging, angio-MR of the brain, and lumbar puncture were normal. EEG when seizures started, it showed diffuse slowing, as in the case of metabolic encephalopathy. This led us to assay blood ammonia, which was high at >400 mmol. Liver function and abdominal US were normal; hence, we suspected a urea cycle enzymatic abnormality, and requested for genetic tests. These confirmed a congenital primary metabolic deficiency of arginine succinate synthetase, with high citrullinemia (type II, adult form). Dialysis was started promptly, with initially iv arginine, then orally, plus medical therapy for the hyperammoniemia and a low protein diet; plasma ammonia dropped swiftly to normal, and her state of consciousness gradually improved until all the clinical symptoms had resolved. Ammonia assay should always be considered in the first few days of the puerperium in women with headache and behavioral disorders, to exclude an inborn deficiency of the urea cycle, which may have gone unnoticed until then.

Saxagliptin: a new dipeptidyl peptidase 4 inhibitor for type 2 diabetes.

OBJECTIVE: To review the pharmacology, pharmacokinetics, efficacy, and safety of saxagliptin, a new dipeptidyl peptidase-4 (DPP-4) inhibitor for the treatment of type 2 diabetes. DATA SOURCES: Searches of PubMed (1966-March 2010) and International Pharmacy Abstracts (1970-March 2010) were conducted using the key words saxagliptin, Onglyza, and BMS-477118. A review of bibliographies of retrieved articles was also performed to identify additional references. STUDY SELECTION AND DATA EXTRACTION: All identified studies published in English and involving efficacy and safety of saxagliptin in the treatment of type 2 diabetes were reviewed. DATA SYNTHESIS: Saxagliptin is a competitive inhibitor of DPP-4 that slows the degradation of incretin hormones, thereby stimulating insulin secretion, reducing postprandial glucagon, and decreasing glucose levels. Saxagliptin is well absorbed after oral administration and demonstrates a pharmacokinetic profile that is compatible with once-daily dosing. Clinical trials with saxagliptin monotherapy for the treatment of type 2 diabetes showed a reduction in hemoglobin A(1c) (A1C) of 0.43-0.9%. Saxagliptin has demonstrated similar reductions in A1C when used as add-on therapy with metformin, sulfonylureas, and thiazolidinediones. The combination of saxagliptin and metformin for initial therapy in treatment-naïve patients was associated with greater improvements in A1C than either agent alone. In general, saxagliptin therapy is well tolerated. The most common adverse effects occurring in clinical trials were headache, nasopharyngitis, upper respiratory tract infections, and urinary tract infections. CONCLUSIONS: Saxagliptin is effective as monotherapy or add-on therapy for the management of type 2 diabetes. Because saxagliptin has a higher cost and reduces A1C and other surrogate markers of glucose control to a lesser extent than other well-validated therapies, such as metformin, saxagliptin should be reserved for patients who fail or are intolerant of conventional treatments for type 2 diabetes.

Nitric oxide-induced changes in endothelial expression of phosphodiesterases 2, 3, and 5.

OBJECTIVE: To investigate nitric oxide (NO)-mediated changes in expression of cyclic nucleotide degrading phosphodiesterases 2A (PDE2A), PDE3B, and PDE5A in human endothelial cells. BACKGROUND: Nitric oxide induces production of cyclic guanosine monophosphate (cGMP), which along with cyclic adenosine monophosphate (cAMP) is degraded by PDEs. NO donors and selective inhibitors of PDE3 and PDE5 induce migraine-like headache and play a role in endothelial dysfunction during stroke. The current study investigates possible NO modulation of cGMP-related PDEs relevant to headache induction in a cell line containing such PDEs. METHODS: Real time polymerase chain reaction and Western blots were used to show expression of PDE2A, PDE3B, and PDE5A in a stable cell line of human brain microvascular endothelial cells. Effects of NO on PDE expression were analyzed at specific time intervals after continued DETA NONOate administration. RESULTS: This study shows the expression of PDE2A, PDE3B, and PDE5A mRNA and PDE3B and PDE5A protein in human cerebral endothelial cells. Long-term DETA NONOate administration induced an immediate mRNA up-regulation of PDE5A (1.9-fold, 0.5 hour), an early peak of PDE2A (1.4-fold, 1 and 2 hours) and later up-regulation of both PDE3B (1.6-fold, 4 hours) and PDE2A (1.7-fold, 8 hours and 1.2-fold after 24 hours). Such changes were, however, not translated into significant changes in protein expression indicating few, if any, functional effects. CONCLUSIONS: Long-term NO stimulation modulated PDE3 and PDE5 mRNA expression in endothelial cells. However, PDE3 and PDE5 protein levels were unaffected by NO. The presence of PDE3 or PDE5 in endothelial cells indicates that selective inhibitors may have functional effects in such cells. A complex interaction of cGMP and cAMP in response to NO administration may take place if the mRNA translates into active protein. Whether or not this plays a role in the headache mechanisms remains to be investigated.

Migraine in the Andes and headache at sea level.

In Cerro de Pasco (CP), Peru (altitude 4338 m) 24% of men have migraine with aura. We studied 30 men. Twenty CP natives, examined in CP, were rated using a chronic mountain sickness (CMS) score to separate controls (10) from those with CMS (10), a maladaptation syndrome in natives to altitude which includes severe, recurring headache. We collected white cells in CP and, from the same men, within 1 h of arrival in Lima (150 m above sea level). Ten normal US men volunteered white cells for comparison. After RNA extraction we assessed gene expression by reverse transcription-polymerase chain reaction. Low ATP1A1 subunit of the ATPase gene mRNA expression in CP was correlated with headache (P=0.002), acral paraesthesias (P=0.004) and CMS score (P<0.001). ATP1A1 subunit expression was increased in all Andeans in Lima (P<0.001). There were no differences between Andean controls in Lima and US controls. Manipulation of Na+/K+ATPase could offer relief for migraineurs at sea level.

COX-2 inhibitor for the treatment of idiopathic stabbing headache secondary to cerebrovascular diseases.

The idiopathic stabbing headache (ISH) is characterized by a stabbing pain of short duration, variable localization and an errant evolution pattern. As its biological mechanisms are unknown and the treatment options are little effective, this disorder shows a strong impact on the patient's life. Two females and one male, aged 76, 66 and 72 years, respectively, started presenting ISH within 20 days after the onset of a stroke. All the patients were treated for the ISH with celecoxib, a COX-2 specific inhibitor, with full recovery from ISH up to 6 days after it was first administered. The interruption of the drug 60 days after the treatment with celecoxib induced again the appearance of algic symptoms in two patients. We concluded that cerebrovascular diseases (CD) can lead to ISH and that the COX-2 inhibitor can be an effective prophylactic drug for ISH after CD.

Platelet superoxide dismutase in migraine and tension-type headache.

Superoxide dismutase (SOD) is a radical-scavenging enzyme. We determined Cu, Zn-SOD concentrations and activities in platelets from subjects with migraine and tension-type headaches. Thirty migraine without aura (MWoA) patients, 9 migraine with aura (MWA) patients, and 53 tension-type headache patients were selected for study. Thirty healthy volunteers composed the control group. Concentrations of platelet SOD were determined using enzyme-linked immunosorbent assay techniques. The activity of platelet SOD was determined by measuring reductivity of nitroblue tetrazolium. Low concentrations of platelet SOD were found in patients with MWA and MWoA. Platelet SOD activity decreased in MWA patients but not in patients with MWoA or tension-type headaches. These findings suggest vulnerability to oxidative stress in patients with migraine. It is suggested that low platelet SOD levels may play an important role in the etiology of migraine.

Platelet 3H-imipramine binding and sulphotransferase activity in primary headache.

We investigated platelet 3H-imipramine (3H-IMI) binding, a putative peripheral serotonergic marker, and the activity of sulphotransferase (ST), an enzyme involved in the catabolism of catecholamines and phenolic compounds, in 14 patients suffering from migraine without aura (MWoA) and in 10 with tension-type headache (TH), as compared with a group of controls. The possible relationships between the biological parameters and clinical features were also examined. The results showed that the two groups of patients had a lower number of 3H-IMI binding sites and a lower activity of the thermolabile form of ST, which acts preferentially on monoamine substrates, than the healthy controls, with no intergroup differences. Significant correlations between psychopathological rating scales and characteristics of the illness were observed in the patients with TH. The decreased number of platelet 3H-IMI binding sites is suggestive of a presynaptic serotonergic dysfunction and confirms the involvement of 5HT in primary headaches. The reduced ST activity might produce changes in the level of sulphated biogenic amines, including dopamine and tyramine, which might have an additional role in the pathophysiology of some aspects of primary headache.

[The histamine-free diet]. / Die histaminfreie Diät.

Food intolerance is not IgE-mediated but caused by histamine. A diminished histamine degradation based on a deficiency of diaminoxidase is suspected to be the reason. The therapeutic efficacy of a histamine-free diet was evaluated in 100 patients with food intolerance and allergic diseases, who were required to avoid fish, cheese, hardcured sausage, pickled cabbage, wine and beer for 4 weeks. Considerable improvement was observed in 57 patients, 15 of whom had total remission. The most striking treatment results were obtained in food or wine intolerance (80% P < 0.05; treatment of choice), bronchial asthma (80%), headache (64%) and urticaria (58%). After ingestion of food rich in histamine clearcut recurrence of atopic eczema was seen in 50% of the patients affected. Histamine plays a major part in food and wine intolerance. Histamine in food causes worsening of symptoms in atopics and patients suffering from headache. The results obtained indicate a deficiency of diaminoxidase in patients with intolerance to food or wine. Histamine levels in alcoholic beverages should be displayed on the labels.

Psychiatric morbidity, platelet monoamine oxidase and tribulin output in headache.

A significantly higher proportion of patients with headache showed scores in the psychopathological range of the General Health Questionnaire (GHQ) compared with controls, with ratings particularly high on the anxiety and depression subscales. Across the whole group, there was a significant negative correlation between platelet monoamine oxidase (MAO) activity and GHQ score overall, and with the anxiety and depression subscales. There was a significant positive correlation between platelet MAO activity and urinary output of the endogenous MAO inhibitor, tribulin. Within the migraine group, there was a significant negative correlation between tribulin output and GHQ score. These findings suggest that the biochemical nature of the anxiety associated with migraine may differ from that in other conditions such as generalized anxiety disorder where high platelet MAO activity and high tribulin output have been reported.

Enkephalinase activity in both physiological and pathological conditions in man.

Among all the enzymes involve din enkephalin degradation "enkephalinase", cleaving the Gly3-Phe4 amide bond, is considered for its specificity with endogenous enkephalins and their receptors. This enzyme, first identified in membrane bound form, has been recently characterized in a soluble one by a new sensitive fluorimetric method substituting the radiometric technique. The possibility to evaluate "enkephalinase" activity in human plasma, amniotic fluid and cerebro spinal fluid (CSF) allows us to investigate its behavior in various physiological and pathological conditions in which alterations of the endogenous opioid system are hypothesized. Our studies were focused on pregnancy, the first period of life, idiopathic headache and opioid addiction. In these conditions "enkephalinase" activity (EKA) generally results increased. In some cases the activity is proportional to the increased amount of substrate, in other cases no correlation seems apparent.

Low platelet monoamine oxidase activity in headache: no correlation with phenolsulphotransferase, succinate dehydrogenase, platelet preparation method or smoking.

Platelet monoamine oxidase activity in male migrainous and cluster headache patients was significantly lower than in male controls, confirming our previous study. The activity range showed a normal distribution and low mean values could not be attributed to a subgroup with particularly low activity. When Corash 's platelet preparation method was used, with its high platelet yield, specific enzyme activities of a similar order were obtained. Thus, the low values encountered were not due to abnormal recovery within the platelet population. Two other enzyme activities, phenolsulphotransferase M and succinate dehydrogenase, were also measured in the same platelet samples. Although low succinate dehydrogenase activity was identified in the headache groups, it appeared to represent a separate phenomenon and there was no significant correlation between activity of either enzyme and that of monoamine oxidase. This shows that the low activity of platelet monoamine oxidase in headache is not related to a generalised platelet enzyme deficit. It was also shown that the low monoamine oxidase activity in the headache patients could not be attributed to smoking.

Platelet monoamine oxidase: specific activity and turnover number in headache.

Monoamine oxidase turnover numbers (molecules of substrate converted to product per minute per active site) have been calculated for the human platelet enzyme using [3H]pargyline. Headache patients with high and low monoamine oxidase specific activities relative to controls were found to have turnover numbers very close to those for controls. This finding suggests that their specific activities vary because of differences in the concentration of active monoamine oxidase molecules, rather than differences in the ability of those enzyme molecules to catalyse the deamination reaction.

Platelet monoamine oxidase activity and headache.

Mean platelet monoamine oxidase activity was reduced compared with control values in groups of headache-free male (but not female) patients suffering from classical migraine and from tension headache. Mean activity in male cluster patients, headache free, both during acute and quiescent phases of their illness, was also notably reduced. Retesting some migraine subjects after up to four years, showed that low activity may be a persistent feature: the correlation coefficient for repeated assays was 0.91 (p less than 0.01). There was no relationship between platelet monoamine oxidase activity and history of dietary migraine. A subgroup of headache patients with permanently low monoamine oxidase activity values may have been defined.

[Platelet monoamine oxidase activity in some neurological diseases of childhood]. / Attività monoaminossidasica piastrinica in alcune malattie neurologiche dell'infanzia.

In this work, we examined platelet MAO activity in 25 children with various neurological disorders and compared them with 30 control subjects. We found that platelet MAO activity changed in children with headache and very little in children with epilepsy and mental retardation. It is very difficult to interpret these results; therefore further works are needed to clarify platelet enzymatic activities.

A study of the activity of platelet monoamine oxidase in patients with migraine headaches or with 'cluster headaches'.

The results of the study of the activity of platelet monoamine oxidase (MAO) in patients with migraine headaches or with 'cluster headaches' are presented. In both types of headaches, MAO activity is lower than in normal subjects. We suggest that the low MAO activity is due to a primary constitutional defect.

Serum dopamine-beta-hydroxylase activity in migraine.

Serum dopamine-beta-hydroxylase (DBH) activity was measured during headache-free intervals in 17 patients with migraine and during the headache interval in 16 patients with muscle contraction headache, as well as in 40 normal subjects. The DBH activity was significantly higher in the migraine patients (46.5+/4.5 units) than in the controls (24.9+/2.4 units), whereas no significant difference was observed between the patients with muscle contraction headache (29.4+/4.5 units) and the controls.