Protean neuroimaging presentations in an adult with Klebsiella pneumoniae infection

PURPOSE

To report on the findings of a series of cranial computed tomography (CT) and magnetic resonance (MR) imaging studies of a 57-years-old woman with Klebsiella (K.) pneumoniae infection.

CASE REPORT

The patient had fever, consciousness disturbance and left hemiplegia as the initial presentations of K. pneumoniae infection. Initial blood culture grew K. pneumoniae, and a delayed purulent cerebrospinal fluid profile was found later. The serial neuroimaging studies showed cerebral hemorrhage, cerebritis and subsequent multiple abscess formations. In the meanwhile hepatic and pulmonary abscess were also discovered by imaging studies. With a 77- days intravenous ceftriaxone treatment (4 gm/day), the abscess formations of brain, lung and liver were all resolved.

CONCLUSION

This study showed the protean neuroimage features of a woman with K. pneumoniae infection and the confirmation of multiple brain abscesses was made by follow-up neuroimaging studies. These sequential neuroimage findings in one patient are uncommon but deserved special clinical note by the first-line, primary-care physicians including neurologists.

Cerebrotendinous xanthomatosis patients with and without parkinsonism: clinical characteristics and neuroimaging findings

Parkinsonism in cerebrotendinous xanthomatosis (CTX) is rare. There are no published studies with imaging findings of dopamine transporter using (99m)Tc-[2-[[2-[[[3-(4-chlorophenyl)-8-methyl-8-azabicyclo [3,2,1] oct-2-yl] methyl] (2-mercaptoethyl) amino] ethyl] amino]-ethanethiolato(3-)-N2,N2,S2,S2]oxo-[1R-(exo-exo)] ((99m)Tc-TRODAT-1) SPECT in CTX patients. This report is on the clinical details of five genetically-proven CTX patients (two with and three without parkinsonism). Imaging findings using cranial magnetic resonance (MR) imaging and (99m)Tc-TRODAT-1 SPECT are also shown. Clinical correlation of neuroimaging findings and clinical presentations was made. A literature review of the clinical and neuroimaging features of eight CTX patients with parkinsonism reported in the English literature is also presented. The parkinsonian features of our two cases and the other eight reported cases occurred before the age of 50 years. The MR imaging study showed variable findings, in which, besides the common diffuse cerebral and cerebellar white matter lesions shown in CTX, several focal brain lesions were also noted. Of the focal lesions, substantia nigra abnormalities were seen only in the two cases with parkinsonism. The (99m)Tc-TRODAT-1 SPECT study showed different degrees of unilateral or bilateral abnormalities in the striatal binding in both visual and semiquantitative assessments. parkinsonism can be one of the neurologic presentations of CTX. Even though abnormal findings of the substantia nigra were detected in both of our CTX patients with parkinsonism, basal ganglion lesions have not been uniformly described in MR imaging findings of reported CTX patients with parkinsonism. (99m)Tc-TRODAT-1 SPECT study can be of value in the detection of striatal involvement, and the study results also suggest pre-synaptic dopamine neuron involvement in CTX patients with parkinsonism.

Transient attenuation of visual evoked potentials during focal status epilepticus in a patient with occipital lobe epilepsy

PURPOSE

Seizures originating in the occipital areas are relatively uncommon. They are usually characterized by visual hallucinations and illusions or other symptoms related to the eyes and vision.

CASE REPORT

In a 54-year-old woman with occipital lobe epilepsy, complex visual hallucinations, illusions, and migraine-like headache constitute the major clinical manifestations. During focal status epilepticus, ictal electroencephalography revealed rhythmic focal spikes in the right occipital region, rapidly propagating to the right parietal and contralateral occipital areas. Ictal brain single-photon emission computed topography revealed hyperperfusion of the right occipital region. Using a full-field pattern-shift visual evoked potential (VEP) study, we found that the P100 responses on both sides were markedly attenuated in amplitude during occipital focal status epilepticus, whereas the latencies of the VEPs were normal. The amplitude and morphology of P100 responses on both sides, however, returned to the normal range 7 days after cessation of the seizures.

CONCLUSION

In addition to clinical seizure semiology, scalp EEG, SPECT and neuroimaging studies, VEP studies may be used as a supplementary examination tool to provide further information in the patients with occipital lobe seizures or epilepsies.

Serial change in platelet activation markers with aspirin and clopidogrel after acute ischemic stroke

OBJECTIVES

Antiplatelet drugs are widely used for secondary prevention after cerebral ischemia of noncardioembolic origin and different antiplatelet drugs exert different pharmacologic effects. This study investigated differences in platelet activation markers in patients taking either aspirin or clopidogrel after acute ischemic stroke.

METHODS

A prospective randomized case-control study evaluated 70 patients with noncardioembolic stroke treated with either aspirin (100 mg/d) or clopidogrel (75 mg/d) after acute ischemic stroke. Platelet activation markers (CD62P, CD63, and CD40L) were measured by flow cytometry at different time points (<48 hours and days 7, 30, and 90 after stroke). The markers were also evaluated in 30 at-risk control subjects.

RESULTS

Ischemic stroke patients had significantly increased circulating CD62P, CD63, and CD40L in the acute stage compared with the control group. Levels of CD62P, CD63, and CD40L were more significantly reduced in the clopidogrel group than in the aspirin group in the first week after stroke. Furthermore, differences in CD62P and CD63 levels were significant even at 1 month after stroke.

CONCLUSIONS

Patients treated with clopidogrel have lower platelet activity than those taking aspirin after acute ischemic stroke. The stronger effect of clopidogrel is notable 1 week after stroke and persists for at least 1 month. Further large-scale trials are warranted to clarify optimal treatment.

Gly482Ser polymorphism in the peroxisome proliferator-activated receptor gamma coactivator-1alpha gene is associated with oxidative stress and abdominal obesity

The objective of the study was to o investigate the relationship of the Gly482Ser (G482S) polymorphism in the peroxisome proliferator-activated receptor gamma coactivator-1alpha (PPARGC1A) gene and type 2 diabetes mellitus (T2DM), obesity, and oxidative status in Chinese adults. We enrolled 276 T2DM patients and 1049 nondiabetic subjects aged at least 35 years. The G482S variant was detected using polymerase chain reaction and restriction enzyme digestion. The levels of thiobarbituric acid reactive substance, an indicator of lipid peroxidation, were measured in plasma samples. The homeostasis model assessment-estimated insulin resistance (HOMA-IR) index was determined for nondiabetic subjects. P values were adjusted for age, sex, and body mass index by using a generalized linear model. In this series, there was no association between G482S polymorphism and T2DM and obesity (body mass index >25 kg/m(2)). However, the plasma fasting insulin levels and HOMA-IR indices were significantly higher in nondiabetic subjects harboring the variant (S/S) genotype than in those with the heterozygous (G/S) genotype. With regard to the effect of the different genotypes on body fat distribution, overweight nondiabetic subjects harboring the S/S or G/S genotype had a significantly higher waist-to-hip ratio than those with the wild-type (G/G) genotype. Furthermore, subjects with the S/S genotype had significantly higher serum thiobarbituric acid reactive substance levels than those with the G/G genotype; the diabetic group mainly contributed to this significant association (P < .001). In overweight, nondiabetic Chinese adults, G482S polymorphism in the PPARGC1A gene is associated with hyperinsulinemia, HOMA-IR indices, and abdominal obesity. Furthermore, in hyperglycemia, the S482 allele is related to increased oxidative stress.

Protective effects of peroxisome proliferator-activated receptors gamma coactivator-1alpha against neuronal cell death in the hippocampal CA1 subfield after transient global ischemia

Peroxisome proliferator-activated receptors gamma coactivator-1alpha (PGC-1alpha) may regulate the mitochondrial antioxidant defense system under many neuropathological settings. However, the exact role of PGC-1alpha in ischemic brain damage is still under debate. Based on an experimental model of transient global ischemia (TGI), this study evaluated the hypothesis that the activation of PGC-1alpha signaling pathway protects hippocampal CA1 neurons against delayed neuronal death after TGI. In Sprague-Dawley rats, significantly increased content of oxidized proteins in the hippocampal CA1 tissue was observed as early as 30 min after TGI, followed by augmentation of PGC-1alpha expression at 1 hr. Expression of uncoupling protein 2 (UCP2) and superoxide dismutases 2 (SOD2) in the hippocampal CA1 neurons was upregulated 4-48 hr after TGI. In addition, knock-down of PGC-1alpha expression by pretreatment with a specific antisense oligodeoxynucleotide in the hippocampal CA1 subfield downregulated the expression of UCP2 and SOD2 with resultant exacerbation of oxidative stress and augmentation of delayed neuronal cell death in the hippocampus after TGI. Overall, our results indicate that PGC-1alpha is induced by cerebral ischemia leading to upregulation of UCP2 and SOD2, thereby providing a neuroprotective effect against ischemic brain injury in the hippocampus by ameliorating oxidative stress.

Mitochondrial dysfunction and oxidative stress in seizure-induced neuronal cell death

Epilepsy is considered one of the most common neurological disorders worldwide. The burst firing associated with prolonged epileptic discharges could lead to a large number of changes and cascades of events at the cellular level. From its role as the cellular powerhouse, the mitochondrion is emerging as a key participant in cell death because of its association with an ever-growing list of apoptosis-related proteins. Prolonged seizures may result in the mitochondrial dysfunction and increased production of reactive oxygen species and nitric oxide (NO) precede neuronal cell death and cause subsequent epileptogenesis. Emerging evidences also showed that intrinsic mitochondrial apoptotic pathway may contribute to the neuropathology of human epilepsy, particularly in the hippocampus. Subsequent laboratory studies in the animal model of status epilepticus provide credence to the notion that activation of nuclear factor-κB upregulates NO synthase (NOS) II gene expression with temporal correlation of NOS II derived NO-, superoxide anion- and peroxynitrite-dependent reduction in mitochondrial Complex I activity, leading to apoptotic neuronal cell death in the hippocampus. These results will broaden our understanding on the intimate link between mitochondrial function, oxidative stress and mitochondria-dependent apoptotic signaling triggered by epileptic seizures. It will open a new vista in the development of more effective neuroprotective strategies against seizure-induced brain damage by modification of bioenergetic failure in the mitochondria and in the design of novel treatment perspectives for therapy-resistant forms of epilepsy.

Risk factors for seizures after first-time ischemic stroke by magnetic resonance imaging

BACKGROUND

Seizures are important neurological complications of ischemic stroke. There is a need to further clarify the risk factors of seizures following ischemic stroke and predict those who will require treatment.

METHODS

One hundred and forty-three (143) first-time ischemic stroke patients were enrolled in this one-year (2002) retrospective study. Prognostic variables were analyzed based on the Cox's proportional hazards model after a minimum follow-up period of six years.

RESULTS

Seizures occurred in 13 first-time ischemic stroke patients, including acute symptomatic seizures in two (1.4%) and unprovoked seizures in 11 (7.7%). Only one progressed to status epilepticus during hospitalization. After six years of follow-up, the median (inter-quartile range) Glasgow Outcome Scale (GOS) was 3 (3,4) for patients with seizures and 4 (3,4) for those without seizures. Regarding seizure control after discharge in the 13 cases, 12 were seizure-free with or without anti-epileptic drugs and one had 1-3 seizures per year. Only the presence of cortical distribution of ischemic infarction (p=0.009, OR=5.549, 95% CI=1.53-20.19) was independently associated with seizures by the Cox's proportional hazards model.

DISCUSSION

The incidence of seizures following first-time ischemic stroke is low and may have delayed manifestation. Cortical distribution of the ischemic infarction is a risk factors for seizures.

Clinical characteristics of spinal involvement in hepatocellular carcinoma

PURPOSE

To analyze the clinical characteristics of hepatocellular carcinoma (HCC) with spinal metastasis.

METHODS

During a period of 14 years, 42 HCC patients with cranial and/or spinal metastasis were identified. Among them, 12 had spinal involvement and thus were included for study. The clinical, laboratory and neuroimaging data of these 12 cases were analyzed.

RESULTS

The 12 cases were all male, aged 36-65 years. The time interval from the diagnosis of HCC to the finding of spinal involvement was 0-38 months. Among these 12 cases, four had the features of spinal involvement in the initial presentation of their HCC. Low back pain was the most common symptom followed by weakness and numbness in the lower limbs. A serum biochemical study did not show unique findings. All 12 cases died within nine months after the diagnosis of the HCC spinal involvement.

CONCLUSIONS

28.6% (12/42) of the HCC patients with nervous system metastasis had spinal involvement and the exact incidence rate can be increased by more extensive neuroimaging studies. Viral hepatitis and liver cirrhosis are common preceding events in patients with HCC with spinal involvement. T- and L-spine are the most commonly involved segments and back pain is the most common complaint in patients with HCC with spinal metastasis. The prognosis in this group of patients is grave and most of the patients died soon after the development the HCC's spinal involvement. No specific biomarker can predict the development of spinal involvement in HCC patients and diagnostic consideration can only be emphasized, especially in HCC hyperendemic areas such as Taiwan.

Brain stem death as the vital determinant for resumption of spontaneous circulation after cardiac arrest in rats

BACKGROUND

Spontaneous circulation returns to less than half of adult cardiac arrest victims who received in-hospital resuscitation. One clue for this disheartening outcome arises from the prognosis that asystole invariably takes place, after a time lag, on diagnosis of brain stem death. The designation of brain stem death as the point of no return further suggests that permanent impairment of the brain stem cardiovascular regulatory machinery precedes death. It follows that a crucial determinant for successful revival of an arrested heart is that spontaneous circulation must resume before brain stem death commences. Here, we evaluated the hypothesis that maintained functional integrity of the rostral ventrolateral medulla (RVLM), a neural substrate that is intimately related to brain stem death and central circulatory regulation, holds the key to the vital time-window between cardiac arrest and resumption of spontaneous circulation.

METHODOLOGY/PRINCIPAL FINDINGS

An animal model of brain stem death employing the pesticide mevinphos as the experimental insult in Sprague-Dawley rats was used. Intravenous administration of lethal doses of mevinphos elicited an abrupt cardiac arrest, accompanied by elevated systemic arterial pressure and anoxia, augmented neuronal excitability and enhanced microvascular perfusion in RVLM. This period represents the vital time-window between cardiac arrest and resumption of spontaneous circulation in our experimental model. Animals with restored spontaneous circulation exhibited maintained neuronal functionality in RVLM beyond this critical time-window, alongside resumption of baseline tissue oxygen and enhancement of local blood flow. Intriguingly, animals that subsequently died manifested sustained anoxia, diminished local blood flow, depressed mitochondrial electron transport activities and reduced ATP production, leading to necrotic cell death in RVLM. That amelioration of mitochondrial dysfunction and bioenergetic failure in RVLM by coenzyme Q10, the mobile electron carrier in mitochondrial respiratory chain, or oxygenation restored spontaneous circulation further established a causal relationship between functionality of RVLM and resumed spontaneous circulation after cardiac arrest.

CONCLUSIONS/SIGNIFICANCE

We conclude that whereas necrotic cell death because of bioenergetic failure triggered by anoxia in RVLM, which precipitates brain stem death, negates resuscitation of an arrested heart, maintained functional integrity of this neural substrate holds the key to resumption of spontaneous circulation after cardiac arrest in rats.

Mitochondrial dysfunction and biogenesis in the pathogenesis of Parkinson's disease

Parkinson's disease (PD) is a progressive neurological disorder marked by nigrostriatal dopaminergic degeneration and development of cytoplasmic aggregates known as Lewy bodies. The impact of this disease is indicated by the fact that mortality is two to five times as high among affected persons as among age-matched controls. However, the cause of PD is still unknown and no cure is available at present. Several biochemical abnormalities have been described in the brains of patients with PD, including oxidative stress and mitochondrial dysfunction. Recent identification of specific gene mutations that cause PD has further reinforced the relevance of oxidative stress and mitochondrial dysfunction in the familial and sporadic forms of the disease. The proteins that are reported to be related to familial PD-PTEN-induced putative kinase 1 (PINK1), DJ-1, alpha- synuclein, leucine-rich repeat kinase 2 (LRRK2), and, possibly, parkin-are either mitochondrial proteins or are associated with mitochondria, and all are involved in pathways that elicit oxidative stress or free radical damage. Mitochondria are continually exposed to reactive oxygen species and accumulate oxidative damage more rapidly than the rest of the cell. Therefore, Parkinson's disease has been suggested to be associated with mitochondrial dysfunction. Since mitochondria are the major intracellular organelles that regulate both cell survival and death, clarifying the involvement of mitochondrial dysfunction and biogenesis during the process of PD could provide treatment strategies that might successfully intervene in the pathogenesis and slow the progression of the disease.

Preservation of mitochondrial integrity and energy metabolism during experimental status epilepticus leads to neuronal apoptotic cell death in the hippocampus of the rat

Status epilepticus results in mitochondrial damage or dysfunction and preferential neuronal cell loss in the hippocampus. Since a critical determinant of the eventual cell death fate resides in intracellular ATP concentration, we investigated whether mitochondrial integrity and level of energy metabolism are related with apoptotic cell death in specific hippocampal neuronal populations. A kainic acid (KA)-induced experimental temporal lobe status epilepticus model was used. Qualitative and quantitative analysis of DNA fragmentation, TUNEL immunohistochemistry, double immunofluorescence staining for activated caspase-3, electron microscopy or measurement of ATP level in the bilateral hippocampus was carried out 1, 3 or 7 days after microinjection unilaterally of a low dose of KA (0.5 nmol) into the CA3 hippocampal subfield. Characteristic biochemical (DNA fragmentation), histochemical (TUNEL or activated caspase-3 staining) or ultrastructural (electron microscopy) features of apoptotic cell death were presented bilaterally in the hippocampus 7 days after the elicitation of sustained hippocampal seizure activity by microinjection of KA into the unilateral CA3 subfield. At the same time, CA3 or CA1 subfield on either side manifested a maintained ATP level; alongside relatively intact mitochondria, rough endoplasmic reticulum, Golgi apparatus or cytoplasmic membrane in hippocampal neurons that exhibited ultrastructural features of apoptotic cell death. Our results demonstrated that preserved mitochondrial ultrastructural integrity and maintained energy metabolism during experimental temporal lobe status epilepticus is associated specifically with apoptotic, not necrotic, cell death in hippocampal CA3 or CA1 neurons.

Long-term antiepileptic drug therapy contributes to the acceleration of atherosclerosis

PURPOSE

Long-term antiepileptic drug (AED) therapy has been associated with an increase in risk of atherosclerosis. At issue is whether this risk is related to the duration of AED therapy. We evaluated the hypothesis that the cumulative effect of long-term exposure to AEDs plays a pivotal role in the pathogenesis of atherosclerosis in patients with epilepsy.

METHODS

One hundred ninety-five patients under long-term AED therapy and 195 healthy age- and sex-matched control subjects received measurement of intima media thickness (IMT) at the far wall of the common carotid artery (CCA) by B-mode ultrasonography to assess the extent of atherosclerosis. Other measurements included body mass index (BMI) and blood lipid profile or homocysteine, folic acid, uric acid, fasting blood sugar, high sensitivity C-reactive protein (hs-CRP), thiobarbituric acid reactive substances (TBARS), and total reduced thiols.

RESULTS

CCA IMT was significantly increased in patients with epilepsy, with male subjects exhibiting thicker IMT than their female counterparts. Whereas BMI, homocysteine, hs-CRP, and TBARS were significantly elevated, folic acid and thiols were significantly reduced in patients with epilepsy. Multiple linear regression analysis further revealed that duration of AED therapy, age, gender, and TBARS level (index for oxidative stress) were independently associated with CCA IMT. In addition, the log-transformed CCA IMT increased linearly with duration of AED therapy after adjustments for age, gender, and TBARS level.

DISCUSSION

The duration of AED therapy is significantly associated with the acceleration of atherosclerosis in patients with epilepsy, alongside independent contributions of age, gender, and oxidative stress to the atherosclerotic process.

Levels and value of platelet activation markers in different subtypes of acute non-cardio-embolic ischemic stroke

INTRODUCTION

Platelet activation and its interaction with leukocytes are important in the pathophysiology of ischemic stroke. This study aimed to evaluate the value of platelet activation and platelet-leukocyte interaction in different subtypes of acute, non-cardio-embolic ischemic stroke.

METHODS

Fifty-four patients with acute, non-cardio-embolic ischemic stroke, including 32 small-vessel and 22 large-vessel diseases, were evaluated. Platelet activation markers (CD62P, CD63, and CD40L) and platelet-leukocyte interaction were measured by flow cytometry at different time points (<48 hours and Days 7, 30, and 90 post-ischemic stroke). Markers were also evaluated in 28 other stroke patients in the convalescent stage (3 to 9 months after acute stroke) and in 28 control subjects.

RESULTS

Patients with ischemic stroke had significantly increased circulating CD62P, CD63, platelet-monocyte interaction, and platelet-lymphocyte interaction in the acute stage compared with the convalescent stage and control groups. Levels of CD62P and CD63 were significantly higher in the large-vessel disease group than in the small-vessel disease group, and differences in CD62P were significant even at one month. The CD40L level in the poor outcome group was significantly higher than that in the good outcome group. Stroke patients with diabetes mellitus and large-vessel disease were associated with poor outcome.

CONCLUSIONS

Patients with large-vessel cerebral infarction elicit higher platelet activation and platelet-leukocyte interaction compared to small-vessel infarction. Further large scale trials are warranted to evaluate the relationship between platelet activation markers and outcome in stroke patients under different anti-platelet therapies, and to clarify optimal treatment.

Prediction, clinical characteristics and prognosis of intracerebral hemorrhage in hepatocellular carcinoma patients with intracerebral metastasis

The clinical characteristics of intracerebral hemorrhage (ICH) in hepatocellular carcinoma (HCC) patients with intracerebral metastasis (IcM) have not been reported on extensively. We compared the clinical characteristics between patients with ICH (w-ICH, 18 patients) and without ICH (wo-ICH, 24 patients) in HCC patients with IcM. Using multivariate logistic regression, only habitual alcohol consumption is a significant predictor of ICH in HCC patients with IcM (adjusted odds ratio [OR]=4.7, 95% CI=1.26-17.71, p=0.022). Patients with ICH also had lower Glasgow Coma Scale scores at the time of admission (p=0.032) and lower incidence of infratentorial metastasis (p=0.014). Using correlation analysis, only blood platelet count on admission was positively correlated with survival duration after the diagnosis of IcM in the wo-ICH group (p=0.000) but not in the w-ICH group.

Abnormal foraging behavior induced by sublethal dosage of imidacloprid in the honey bee (Hymenoptera: Apidae)

Although sublethal dosages of insecticide to nontarget insects have never been an important issue, they are attracting more and more attention lately. It has been demonstrated that low dosages of the neonicotinoid insecticide imidacloprid may affect honey bee, Apis mellifera L., behavior. In this article, the foraging behavior of the honey bee workers was investigated to show the effects of imidacloprid. By measuring the time interval between two visits at the same feeding site, we found that the normal foraging interval of honey bee workers was within 300 s. However, these honey bee workers delayed their return visit for > 300 s when they were treated orally with sugar water containing imidacloprid. This time delay in their return visit is concentration-dependent, and the lowest effective concentration was found to be 50 microg/liter. When bees were treated with an imidacloprid concentration higher than 1,200 microg/liter, they showed abnormalities in revisiting the feeding site. Some of them went missing, and some were present again at the feeding site the next day. Returning bees also showed delay in their return trips. Our results demonstrated that sublethal dosages of imidacloprid were able to affect foraging behavior of honey bees.

Dysregulation of Ca2+ movement in platelets from patients with acute ischaemic stroke

1. Platelets play a pivotal role during acute ischaemic stroke. An increase in cytosolic Ca(2+) concentrations ([Ca(2+)](i)) triggers intracellular signal transduction, leading to platelet aggregation and thrombosis. In the present study, we examined the differences between platelets from acute ischaemic stroke patients and at-risk controls in terms of the increase in platelet [Ca(2+)](i). 2. Thirty-one patients with acute ischaemic stroke and 27 at-risk controls were enrolled in the present study. Platelet [Ca(2+)](i) was measured using the fluorescent dye fura-2 after stimulation with 100 micromol/L arachidonic acid (AA), 10 micromol/L ADP, 1 micromol/L platelet-activation factor (PAF) and 0.1 U/mL thrombin. 3. Basal [Ca(2+)](i) was higher in the stroke group compared with at-risk controls, irrespective of the presence or absence of extracellular Ca(2+). In Ca(2+)-containing medium, both PAF and ADP, but not AA and thrombin, significantly increased platelet [Ca(2+)](i) in the stroke group compared with the at-risk controls. However, in Ca(2+)-free medium, only PAF significantly increased platelet [Ca(2+)](i) in the stroke group compared with the at-risk controls. Basal [Ca(2+)](i) and PAF-induced platelet [Ca(2+)](i) increases were still higher in the stroke group at the subacute stage than in the at-risk controls. 4. The results of the present study provide direct evidence that Ca(2+) signalling in platelets from acute ischaemic stroke patients was altered in response to particular stimuli. The dysregulation of Ca(2+) movement in platelets may persist up to the subacute stage of ischaemic stroke.

Contribution of nitric oxide, superoxide anion, and peroxynitrite to activation of mitochondrial apoptotic signaling in hippocampal CA3 subfield following experimental temporal lobe status epilepticus

PURPOSE

One cellular consequence of status epilepticus is apoptosis in the hippocampal CA3 subfield. We evaluated the hypothesis that the repertoire of cellular events that underlie such elicited cell death entails mitochondrial dysfunction induced by an excessive production of nitric oxide synthase II (NOS II)-derived NO, increased superoxide anion (O(2)(-)) production, and peroxynitrite formation.

METHODS

In Sprague-Dawley rats, kainic acid was microinjected unilaterally into the hippocampal CA3 subfield to induce bilateral seizure-like electroencephalography (EEG) activity. The effects of pretreatments with various test agents on the induced O(2)(-) production, peroxynitrite formation, mitochondrial respiratory chain enzyme activities, cytochrome c/caspase-3 signaling, and DNA fragmentation in bilateral CA3 subfields were examined.

RESULTS

Significantly and temporally correlated increase in O(2)(-) and peroxynitrite levels (3 to 24 h), depressed mitochondrial Complex I activity (3 h), enhanced translocation of cytochrome c to cytosol (day 1), and augmented activated caspase-3 (day 7) and DNA fragmentation (day 7) were detected bilaterally in hippocampal CA3 subfields after the elicitation of sustained seizure. Pretreatment with microinjection into the bilateral hippocampal CA3 subfield of a water-soluble formulation of coenzyme Q(10); a selective NOS II inhibitor, S-methylisothiourea; a superoxide dismutase mimetic, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl; an active peroxynitrite decomposition catalyst, 5,10, 15,20-tetrakis-(N-methyl-4-pyridyl)- porphyrinato iron (III); or a peroxynitrite scavenger, L-cysteine significantly blunted these cellular events.

DISCUSSION

Prolonged seizures prompted NO-, O(2)(-)-, and peroxynitrite-dependent reduction in mitochondrial respiratory enzyme Complex I activity, leading to cytochrome c/caspase-3-dependent apoptotic cell death in the hippocampal CA3 subfield after induction of experimental temporal lobe status epilepticus.

Acute intermittent porphyria presenting as acute pancreatitis and posterior reversible encephalopathy syndrome

Acute intermittent porphyria (AIP) is an inherited metabolic disease that can affect the autonomic, peripheral and central nervous systems. Pancreatic diseases assocated with AIP is rarely reported. We report here a 60-year-old non-alcoholic male who had typical manifestations of AIP, including abdominal pain, constipation, tachycardia, hypertension, mental disturbances, psychiatric manifestations, seizures, peripheral neuropathy, and excessive excretion of porphyrin precursors in urine. Increases of serum amylase and lipase, as well as mild pancreatic edema on ultrasonography, were noted during the acute attack of AIP, suggesting concomitant acute pancreatitis. In this patient, brain magnetic resonance imaging revealed reversible multifocal cerebral lesions resembling a posterior reversible encephalopathy syndrome (PRES) during the acute attack of AIP. Because the clinical manifestations of acute pancreatitis could be present with an acute attack of AIP, early confirmation of diagnosis is mandatory to effectively manage the attack and avoid inappropriate treatment.

Complex partial status epilepticus as a manifestation of Hashimoto's encephalopathy

Epileptic seizures are a frequent manifestation of Hashimoto's encephalopathy. However, status epilepticus associated with Hashimoto's encephalopathy are not well characterized in medical literature. We described here a 16-year-old girl who presented with complex partial status epilepticus associated with elevated anti-thyroid antibodies. Ictal EEG showed lateralized high amplitude rhythmic delta waves over the right hemisphere and ictal single-photon emission computed tomography revealed regional hyperperfusion of the right parietal and temporal lobes. The patient was unresponsive to antiepileptic drug therapy but responded to intravenous steroid treatment. Screening of serum anti-thyroid antibodies for unexplained encephalopathy with epileptic seizures is suggested, as early recognition and prompt steroid treatment may lead to a favorable prognosis.

Adult Pseudomonas aeruginosa meningitis: high incidence of underlying medical and/or postneurosurgical conditions and high mortality rate

We analyzed the clinical and laboratory characteristics, therapeutic outcome and prognostic factors of 25 cases of cerebrospinal fluid (CSF) culture-proven Pseudomonas aeruginosa adult bacterial meningitis (ABM). Twelve P. aeruginosa strains, isolated from clinical CSF specimens, were tested for antibiotic susceptibility. The 25 cases included 17 men and 8 women, aged 17 to 86 years (median=51). Of the 25 cases of P. aeruginosa ABM, 18 were the result of postneurosurgical infection and the other 7 were spontaneous infections. The latter 7 cases had serious underlying medical conditions. The antibiotic susceptibility rates of the 12 strains were as follows: ceftriaxone 16.7% (2/12), ceftazidime 91.7% (11/12), cefepime 83.3% (10/12), imipenem 83.3% (10/12), meropenem 83.3% (10/12) and ciprofloxacin 66.7% (8/12). The therapeutic results showed an overall mortality rate of 40% (10/25). The emergence of third-generation cephalosporin-resistant P. aeruginosa strains cultured from clinical CSF specimens in recent years has resulted in a therapeutic challenge in the treatment of ABM.

Epidemiology of adult staphylococcal meningitis in southern Taiwan: a clinical comparison of Staphylococcus aureus infection and coagulase-negative staphylococcal infection

The clinical and laboratory characteristics of 38 staphylococcal adult bacterial meningitis (ABM) cases (19 Staphylococcus aureus infections and 19 coagulase-negative staphylococcal [CoNS] infections), collected over a period of 6.5 years (July 1999-December 2005; total ABM cases=181) were analyzed. The results were compared with those of our previous study (January 1986-June 1999; total ABM cases=202: monomicrobial infection=180, mixed infection=22, staphylococcal infection=27). The 38 staphylococcal meningitis cases were 21 men and 17 women. Fever and altered consciousness were the leading clinical manifestations. A preceding postneurosurgical state was noted in 12 of the 19 S. aureus infections and all 19 CoNS infections. The ages of onset and mortality rates of S. aureus infection and CoNS infection were 58.21+/-13.05 years and 36.8% (7/19), and 44.16+/-17.57 and 5.3% (1/19), respectively. Eleven of the 19 implicated S. aureus strains and 18 of the 19 implicated CoNS strains were mecA gene-positive and methicillin-resistant; all the strains retained their susceptibility to linezolid. The therapeutic results showed a mortality rate of 21% (8/38). This study revealed an increase of methicillin-resistant, postneurosurgical staphylococcal infection in ABM. Patients with CoNS infection had a younger age at onset and a lower mortality rate.