Impaired cerebrovascular reactivity as a risk marker for first-ever lacunar infarction: A case-control study

BACKGROUND AND PURPOSE

Functional assessment of small arteries and arterioles could provide valuable information regarding the extent of diffuse arteriolosclerosis in patients with small-vessel disease. Therefore we attempted to clarify the role of cerebrovascular reactivity (CVR) as a risk marker for first-ever symptomatic lacunar infarction.

METHODS

Forty-six patients with lacunar infarction and 46 sex- and age-matched control subjects were prospectively evaluated. Cerebral hemodynamics were studied with transcranial Doppler ultrasonography. CVR was examined by calculating the percent increase in mean flow velocity occurring after 15 mg/kg acetazolamide administration (Diamox test).

RESULTS

CVR was significantly (P<0.0001, Student's t test) lower in cases (50.0+/-12. 7%) as compared with control subjects (65.2+/-12.4%). A multiple logistic regression analysis identified male sex (odds ratio [OR] 2. 3, P=0.02), age (OR 3.6, P<0.005), and the presence of lacunar infarction on magnetic resonance imaging (OR 5.3, P<0.001) as significant and independent factors associated with a reduction of CVR. Moreover, a cut-point of 55.6% (sensitivity 67%, specificity 82%) was established as the threshold value for distinguishing between pathological and normal CVR. CVR was significantly (P=0.02) lower in patients with multiple (46.38+/-12.6%) than with single (54. 83+/-11.58%) lacunar infarction. In addition, a trend of negative correlation was found between CVR and the number of lacunar infarctions (r=-0.26, P=0.08). In the multiple logistic model, history of hypertension (OR 7.24; 95% confidence interval 2.95 to 17. 79) and CVR (OR 0.8; 95% confidence interval 0.81 to 0.93) emerge as significant and independent predictors of first-ever lacunar infarction.

CONCLUSIONS

These data suggest that impaired CVR is a risk marker for first-ever lacunar infarction.

["Stroke code". Shortening the delay in reperfusion treatment of acute ischemic stroke]

BACKGROUND

"Stroke Code" is a system for the rapid identification, pre-notification and transport of acute ischemic stroke patients. The objective of this study was to evaluate the impact of delay reduction for thrombolytic therapy in these patients.

SUBJECTS AND METHODS

We evaluated acute ischemic stroke patients admitted in the emergency unit within the first 6 hours after onset of symptoms and included into reperfusion clinical trials. We compared the delay for initiating reperfusion treatment related to the activation or not of the stroke code.

RESULTS

From 454 patients evaluated, 25% were admitted to the hospital in less than 6 hours from stroke onset. 59% of these patients were candidates for reperfusion treatment. "Stroke Code" was activated in 13 (55%). We observed a significant reduction in the delay since the onset of symptoms in relation to "Stroke Code" activation or not (mean X [SD]): emergency room arrival: 49.6 (48) vs 80 (48) min; Stroke Team evaluation: 65.3 (57) vs 133.6 (58) min; CT scan performing: 86.2 (60) vs 171.8 (62) min; Start of treatment; 212.9 (51) vs 287.3 (59) min.

CONCLUSIONS

"Stroke Code" activation reduced in 50% pre- and in-hospital delay to start reperfusion treatment in acute ischemic stroke patients.

[Vertebrobasilar abnormalities in patients with hemifacial spasm: MR-angiography findings]

INTRODUCTION

Hemifacial spasm (HFS) is a disorder characterized by a complex of symptoms with hyperactive motor dysfunction of the facial nerve. It is indicated that HFS in the majority of cases can be caused by a blood vessel compressing the nerve adjacent to the brainstem.

PATIENTS AND METHODS

We studied and treated 44 patients with HFS. Magnetic resonance imaging (MR) and MR-angiography of the brain were performed in patients with HFS to asses the presence of an artery of the vertebrobasilar system compressing the root of the facial nerve. We evaluate the response to treatment with Botulinum toxin in these cases. 14 patients were excluded (6 patients presented HFS due to other lesions and in 8 patients the MR was not performed). The remaining 30 patients with idiopathic HFS underwent MR/MRA (3D-FISP) and it was also performed in 14 patients with synkineses after facial palsy to be used as controls.

RESULTS

The MRA documented an abnormal position of the arteries surrounding the facial nerve (ipsilaterally to HFS) in 22 patients. The compressing artery was the PICA in 3 patients (10%), the AICA in 3 patients, the vertebral artery in 7 patients and the basilar artery in 8 patients, one patient showed a combined compression by AICA and PICA. The remaining 8 patients had a normal MRI. At the control group only one patient presented an abnormal AICA and the other had a normal MRI-MRA. Patients were followed-up for 22.4 months and after Botulinum toxin treatment patients kept 4.81 months free of symptoms.

CONCLUSIONS

We recommend to perform MR studies in all HFS patients to rule out a secondary cause of the disease and MRA to evaluate the underlying vertebrobasilar abnormalities if surgery is planned. Botulinum toxin is a useful treatment in these patients and only after its failure, microvascular decompression will be considered.

[Stroke: a stranger among the people]

INTRODUCTION

Lack of awareness of warning signs of stroke is a factor that contribute to late patient arrival to the emergency department.

OBJECTIVE

The goal of this pilot study was to determine the baseline knowledge of stroke among the population (terminology, signs-symptoms, risk factors and attitude) prior to educational campaigns.

PATIENTS AND METHODS

A population-based interview using closed-ended questions was conducted by neurologists among 100 users of the Vall d'Hebron's Primary Health Center, randomly sampled.

RESULTS

In our population a 9% unknowns totally the disease, of the remainder, 42% has a good knowledge of signs-symptoms and 46% of risk factors. Only 22% of the sample has good global knowledge of the disease. If suffering a stroke this population should seek medical attention through 911 (46.2%) or come directly to the emergency department (50.5%). If symptoms were gone away, transient ischemic attack (TIA), appears a trend to contact primary physicians (59.3%). Respondents aged > 65 years were less likely to recognize symptoms (p = 0.001) and to consider stroke as an emergency. Respondents with an affected relative (50.5%) tend to locate more exactly the disease at the brain (p = 0.05) and to arrive earlier to the emergency department (p = 0.045), than those with non-affected relatives.

CONCLUSIONS

Less than a quarter of our population have a good knowledge of the disease. Stroke is considered an emergency unlike TIA. The information about stroke is theoretically associated with early presentation to the emergency department. These results permit a redesign of the questionnaire to conduct a second phase of the study and generalize them for the Spanish population.

[Presentation of the Environmental-Health Prize 1997: Lyme borreliosis]

Lyme borreliosis is an infectious disease, with multisystem involvement, due to a spirochete known as Borrelia burgdorferi, transmitted to humans by ticks; its recent emergence is, in part, the consequence of reforestation and the rise in deer and rodents populations. The prevention and the treatment of this disease are well standardized, the main risk being its misdiagnosis.

[Isolated axial lateral pulse as a sign of latero-bulbar ischemia: clinical topographic correlation]

INTRODUCTION

Isolated body lateropulsion in absence of vertigo, cerebellar syndrome, sensory loss or motor weakness is an extremely rare. This condition has only been reported four times.

CLINICAL CASES AND CONCLUSION

We present four patients in whom isolated body lateropulsion was a single manifestation of lateral medullary ischemia.

Ectopic ICER expression in pituitary corticotroph AtT20 cells: effects on morphology, cell cycle, and hormonal production

The products of the cAMP response element modulator (CREM) gene play an important role in the transcriptional response to cAMP in endocrine cells. By virtue of an alternative, intronic promoter within the gene, the inducible cAMP early repressor (ICER) isoform is generated. ICER was shown to act as a dominant negative regulator and to be cAMP-inducible in various neuroendocrine cells and tissues. ICER negatively autoregulates its own expression and has been postulated to participate in the molecular events governing oscillatory hormonal regulations. To elucidate ICER function in pituitary physiology, we have generated AtT20 corticotroph cell lines expressing the sense or antisense ICER transcript under the control of the cadmium-inducible human methallothionein IIA promoter. Here we demonstrate that changes in the regulated levels of ICER have drastic consequences on the physiology of the corticotrophs. Ectopic ICER expression induces remarkable modifications in AtT20 morphology. Cells with persistent, nonregulated high levels of ICER are blocked in the G2/M phase of the cell cycle, while the opposite effect is obtained in cells expressing an antisense ICER transcript. We show that the effect of ICER on the AtT20 cell cycle is correlated to a direct down-regulation of the cyclin A gene promoter by ICER. Finally, we show that ACTH hormonal secretion from the corticotrophs is completely blocked by ICER ectopic expression. Interestingly, this effect is not due to a direct regulation of the POMC gene, but is mediated by a transcriptional control of the prohormone convertase 1 gene. These results point to a key regulatory function of CREM in pituitary physiology.

[Jugular megabulb as a cause of pulsatile tinnitus]

INTRODUCTION

Pulsatile tinnitus (AP), possibly of vascular origin, may be a sign of various vascular and non-vascular pathological processes. Arteriovenous fistulas and malformations are, perhaps, the commonest cause of AP.

CLINICAL CASE

A 64 year-old woman presented with AP of the right ear for the past 14 years. It was continuous all day and could be observed externally by the examiner. The intensity of the tinnitus diminished on right later-cervical compression and on turning her head to the left. There was bilateral transmission deafness. Neurological examination was normal. Complementary explorations (MR, CT of the base of the skull and cerebral arteriography) showed the presence of a jugular megabulb of the right side.

CONCLUSIONS

The presence of AP may be for many years the only sign of subjacent vascular pathology, such as a megabulb of the jugular vein.

Slow cluster formation of purified human or rhesus T cells requires protein kinase C and LFA-1

Homotropic T cell adhesion, as generally studied, consists of a rapid, transient binding process that is measured over a 15-120 min. period. Here we report a slow type of adhesion process occurring with human or rhesus T cells, purified from peripheral blood, that manifests itself by the formation of rounded, multi-layer clusters which may contain hundreds of cells. The maximal number and size of the clusters peak 1-2 days after the addition of phorbol ester, an absolute requirement. The number of clusters formed is proportional to phorbol ester concentration up to 1.25 ng/mL. Phorbol esters such as phorbol myristate acetate (PMA), phorbol dibutyrate (PDB), and 7-octylindolactam (OIL) induced optimal cluster formation at 1-13 ng/mL, levels slightly higher than that required to induce mitogenesis of purified T cells. Phorbol itself and the alpha-form of the ester were inactive. Both cluster formation and mitogenesis (stimulated by Con A or anti-CD3) are completely inhibited by staurosporin at 12.5 ng/mL. Even at 2.5 ng/mL, 74% of cluster formation was inhibited, which strongly implies a crucial role for protein kinase C. In the presence of accessory cells, T cell clusters were suppressed. Monoclonal Ab such as anti-CD3, mouse anti-CD3 followed by anti-mouse IgG, anti-CD4, anti-CD4A, anti-CD2, anti-CD8, and anti-CD45 did not induce cluster formation. None were inhibitory or stimulatory in the presence of PMA, except for anti-CD3 which enhanced cluster formation by 26%. However, anti-LFA-1 beta-chain (mouse monoclonal) completely blocked cluster formation over the range studied (63-1000 ng/mL) for both human and rhesus cells; rat anti-LFA-1 only blocked human cell adhesion. Anti LFA-1 only partially inhibited T cell mitogenesis. These results show that slow cluster formation shares the LFA-1 and phorbol ester requirements of the rapid adhesion of T cells requiring LFA-1 and ICAM-1. However, cluster occurs at a very low phorbol ester concentration, appears more sensitive to staurosporin inhibition, and is not stimulated via the TCR receptor like the rapid adhesion process. We hypothesize that certain neuronal processes, induced by phorbol ester, and which also show a similar protein kinase C activation time course, may share mechanisms in common with cluster formation.

[Diarrhea and AIDS: more complex diagnostic techniques; better therapeutic results]

During 17 months, 73 HIV-positive patients with diarrhea lasting at least for 14 days, were studied prospectively. The patients had stool specimen examinations negative for enteric pathogens, or positive for one of them, but with no response to specific treatment. All patients were subcomitted to digestive endoscopy and biopsies were taken for microbiological and histological studies. The etiology of the diarrhea could be established in 48 patients (66%). In 45, the cause was an enteric infection. There was association of 2 pathogens in 11 patients, and of 3 in 1 patient. The agents found were: Cryptosporidium (24%), MAI (16%), Giardia lambila (12%), isospora belli (5%), Shigella (5%), Salmonella (5%); Entamoeba histolytica (3%), HSV (3%), tuberculosis (2%), adherent bacteria (2%) and spirochetes (2%). In 3 patients the etiology was not infection, their diagnoses were coeliac disease, lymphoma and idiophatic colonic ulcers, respectively. In 51% of the cases only the examination of endoscopic biopsy specimens could identify the cause of the diarrhea. These results justify the use of these methods to improve diagnosis and therapeutic attempts in these patients.

[Somatosensory focal seizures as an onset form in adult Moyamoya syndrome]

Moya-Moya disease is a chronic infrequent vasculopathy. Occasionally such abnormalities are found in association with one of many conditions, in these cases the angiographic abnormality should be termed Moya-Moya syndrome rather than Moya-Moya disease. Although in children the usual manifestations are ischemic events and seizures. This clinical presentation is infrequent in adults. We present a 42-years-old man with a 1-month history of recurrent right sided partial somatosensorial seizures, later he presented a left parietal infarction, the angiographic findings were compatible with moyamoya syndrome.

Trace determination of herbicides in estuarine waters by liquid chromatography-high-flow pneumatically assisted electrospray mass spectrometry

High-flow pneumatically assisted electrospray (ESP) was applied to the characterization of triazine (atrazine, simazine, ametryne, cyanazine, deethylatrazine and deisopropylatrazine), phenylurea (chlortoluron++, isoproturon, diuron, linuron and diflubenzuron) and other priority herbicides (alachlor, metolachlor). In LC-ESP-MS the [M+Na]+ ion was used as the base peak in most cases, with the exception of chlorotriazines, which showed [M+H]+ as the base peak. When LC-TSP-MS was used, [M+H]+ was the base peak for many of the pesticides, with the exception of linuron and diflubenzuron, which showed [M+NH4]+ as the base peak. The ESP results were compared with those obtained with thermospray (TSP). LC-TSP-MS offered greater sensitivity for triazines than phenylurea herbicides, whereas the use of LC-ESP-MS offered an enhancement in sensitivity for phenylurea herbicides. As regards the fragmentation obtained using both techniques, ESP offered a considerable amount of structural information for the different chlorotriazines studied when the extraction voltage was increased from 20 to 40 V. Liquid-liquid extraction with dichloromethane was used for the trace enrichment of the different herbicides in estaurine water samples from the Elorn river (France). The presence of the different triazine metabolites, atrazine, simazine, metolachlor, isoproturon and diuron was confirmed by both LC-MS techniques.

Prognostic implications of clinical, electrocardiographic and hemodynamic findings in chronic Chagas' disease

To evaluate the prognostic importance of 19 clinical, electrocardiographic and hemodynamic variables, 556 chronic chagasic patients were submitted to an extensive protocol, including left cineventriculogram and Holter monitoring, and followed for up to 15 years. The protagonist role of the magnitude of the myocardial compromise in the evolution of chagasic patients is underscored by our results, which indicated the independent prognostic value of an ejection fraction below 0.30 (P < 0.001), a heart rate higher than 89 beats/min (P < 0.01), grade IV functional capacity (P < 0.05), end systolic stress > 120 g/cm2 (P < 0.05), and end diastolic volume index > 200 ml/m2 (P < 0.05). When only patients with an ejection fraction over 0.29 were considered, variables with independent prognostic value were: the cardio-thoracic ratio (P < 0.01), functional capacity (P < 0.05) and heart rate (P < 0.05). Survival analysis demonstrated that the presence of complex (Lown III, IV) ventricular arrhythmias increased mortality significantly (P < 0.01) only in patients with an ejection fraction over 0.29. Therefore, preservation of myocardial function is the capital measure in the treatment of chronic chagasic patients.