Risk of Microangiopathy in Patients with Epilepsy under Long-term Antiepileptic Drug Therapy

Background

Long-term antiepileptic drug (AED) therapy is considered a risk factor of atherosclerosis. Furthermore, the duration of therapy contributes to acceleration of large-vessel atherosclerosis. Therefore, in this study, we tested the hypothesis that long-term AED therapy plays a crucial role in the pathogenesis of microangiopathy in patients with epilepsy.

Methods

We recruited 120 patients with epilepsy (age, 18–60 years) and 40 healthy controls. Optical coherence tomography (OCT) was used to measure the central macular thickness and diameters of the retinal artery and vein to evaluate atherosclerotic retinopathy; microalbumin and creatinine levels in urine were assessed to evaluate atherosclerotic nephropathy. In addition, high-sensitivity C-reactive protein (hs-CRP), lipid profiles, homocysteine, folate, uric acid, and body mass index were determined.

Results

The ratio of urine albumin to creatine and OCT findings showed that patients with epilepsy had higher abnormal microalbuminuria and narrowing retinal vein diameters, respectively. Multiple linear regression analysis showed that increased triglyceride and hs-CRP levels might contribute to microalbuminuria. In addition, serum creatinine, duration of AED therapy, enzyme-inducing AED therapy, and duration of enzyme-inducing AED therapy were candidate risk factors for retinal vein narrowing.

Conclusion

Patients with epilepsy are at a higher risk for microangiopathy presented as retinopathy and nephropathy. Long-term AED therapy, particularly with enzyme-inducing AEDs; high triglyceride levels, and inflammatory processes play an important role in the development of microangiopathy in patients with epilepsy.

Dynamin-Related Protein 1 Promotes Mitochondrial Fission and Contributes to The Hippocampal Neuronal Cell Death Following Experimental Status Epilepticus

AIMS

Prolonged seizure activity may result in mitochondrial dysfunction and lead to cell death in the hippocampus. Mitochondrial fission may occur in an early stage of neuronal cell death. This study examined the role of the mitochondrial fission protein dynamin-related protein 1 (Drp1) in the hippocampus following status epilepticus.

METHODS

Kainic acid (KA) was microinjected unilaterally into the hippocampal CA3 area in Sprague Dawley rats to induce prolonged seizure activity. Biochemical analysis, electron microscopy, and immunofluorescence staining were performed to evaluate the subsequent molecular and cellular events. The effects of pretreatment with a mitochondrial fission protein inhibitor, Mdivi-1 (2 nmol), were also evaluated.

RESULTS

Phosphorylation of Drp1 at serine 616 (p-Drp1(Ser616)) was elevated from 1 to 24 h after the elicited seizure activity. Pretreatment with Mdivi-1 decreased the Drp1 phosphorylation at Ser616 and limited the mitochondrial fission. Mdivi-1 rescued the Complex I dysfunction, decreased the levels of oxidized proteins, decreased the activation of cytochrome c/caspase-3 signaling, and blunted cell death in CA3 neurons.

CONCLUSION

Our findings suggest that activation of p-Drp1(Ser616) is related to seizure-induced neuronal damage. Modulation of p-Drp1(Ser616) expression is accompanied by decreases in mitochondrial fission, mitochondrial dysfunction, and oxidation, providing a neuroprotective effect against seizure-induced hippocampal neuronal damage.

Interictal serum brain-derived neurotrophic factor level reflects white matter integrity, epilepsy severity, and cognitive dysfunction in chronic temporal lobe epilepsy

OBJECTIVE

Most patients with temporal lobe epilepsy (TLE) have epileptic foci originating from the medial temporal lobe, particularly the hippocampus. Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin growth factor mainly expressed in the hippocampus, though it is not known whether the circulating level of BDNF reflects cognitive performance or white matter structural changes in chronic TLE.

METHODS

Thirty-four patients with TLE and 22 healthy controls were enrolled for standardized cognitive tests, diffusion tensor imaging, and serum BDNF measurement. The patients were further divided into a subgroup with unilateral TLE (n=23) and a subgroup with bilateral TLE (n=11) for clinical and neuroimaging comparisons.

RESULTS

There were significantly lower BDNF levels in the patients with TLE compared with the controls, with significance contributed mainly from the subgroup with bilateral TLE, which also had more frequent seizures. The BDNF levels correlated with epilepsy duration (σ=-0.355; p=0.040) and fractional anisotropy (FA) in the left temporal lobe, left thalamus, and right hippocampus. Using a regression model, BDNF level predicted verbal memory score. Further, design fluency scores were predicted by serum BDNF level via the interactions with left temporal FA.

CONCLUSIONS

Serum BDNF levels reflected longer epilepsy duration, impaired white matter integrity, and poor cognitive function in patients with chronic TLE.

Status epilepticus associated with pregnancy: A cohort study

BACKGROUND

Status epilepticus (SE) is a neurological emergency associated with a high mortality rate and long-term cognitive sequelae. Status epilepticus in pregnancy poses a tremendous threat to both mother and fetus, making a correct diagnosis and treatment a challenging task for clinicians. The prevalence, underlying etiology, and outcomes of pregnancy-related SE remain largely unknown.

METHODS

We retrospectively studied all SE episodes (n=366) in patients admitted to our neurological ICU over a period of 8.5years. The patients who developed SE during pregnancy and within 6months after delivery were considered to have pregnancy-related SE. Patients with eclampsia were not included as they were usually cared for in our obstetric unit.

RESULTS

Seven patients with pregnancy-related SE were identified (2.1% of all cases of SE), with the majority (85%) occurring de novo except for one patient who had a previous history of epilepsy-related SE due to withdrawal of antiepileptic medication. In terms of etiology, limbic encephalitis and cerebral venous sinus thrombosis were the two main etiologies of de novo SE associated with pregnancy. The overall mortality rate was 28.5% at discharge, and poor outcomes were especially noted in the patients with limbic encephalitis compared to other etiologies.

CONCLUSIONS

Pregnancy-associated SE is rare and predominantly occurs in patients without a history of epilepsy. An autoimmune etiology should be considered in pregnant patients with de novo SE, which was associated with poor outcomes. Thorough investigations and prompt treatment according to the etiology may be required to improve the final outcomes of both mother and fetus.

Peroxisome proliferator-activated receptor-gamma dependent pathway reduces the phosphorylation of dynamin-related protein 1 and ameliorates hippocampal injury induced by global ischemia in rats

BACKGROUND

Dynamin-related protein 1 (Drp1) is a mitochondrial fission protein that, upon phosphorylation at serine 616 (p-Drp1(Ser616)), plays a pivotal role in neuronal death after ischemia. In the present study, we hypothesized that peroxisome proliferator-activated receptor-gamma (PPARγ)-dependent pathway can reduce the expression of p-Drp1(Ser616) and ameliorate hippocampal injury induced by global ischemia in rats.

RESULTS

We found that pretreatment of the rats with Mdivi-1, a selective Drp1 inhibitor, decreased the level of transient global ischemia (TGI)-induced p-Drp1(Ser616) and reduced cellular contents of oxidized proteins, activated caspase-3 expression as well as the extent of DNA fragmentation. Delivery of siRNA against Drp1 attenuated the expression of p-Drp1(Ser616) that was accompanied by alleviation of the TGI-induced protein oxidation, activated caspase-3 expression and DNA fragmentation in hippocampal proteins. Exogenous application of pioglitazone, a PPARγ agonist, reduced the p-Drp1(Ser616) expression, decreased TGI-induced oxidative stress and activated caspase-3 expression, lessened the extents of DNA fragmentation, and diminished the numbers of TUNEL-positive neuronal cells; all of these effects were reversed by GW9662, a PPARγ antagonist.

CONCLUSIONS

Our findings thus indicated that inhibition of TGI-induced p-Drp1(Ser616) expression by Drp1 inhibitor and Drp1-siRNA can decrease protein oxidation, activated caspase-3 expression and neuronal damage in the hippocampal CA1 subfield. PPARγ agonist, through PPARγ-dependent mechanism and via decreasing p-Drp1(Ser616) expression, can exert anti-oxidative and anti-apoptotic effects against ischemic neuronal injury.

Roles of Sestrin2 and Ribosomal Protein S6 in Transient Global Ischemia-Induced Hippocampal Neuronal Injury

Recent studies suggested that sestrin2 is a crucial modulator for the production of reactive oxygen species (ROS). In addition, sestrin2 may also regulate ribosomal protein S6 (RpS6), a molecule important for protein synthesis, through the effect of mammalian target of rapamycin (mTOR) complex that is pivotal for longevity. However, the roles of sestrin2 in cerebral ischemia, in which oxidative stress is one of the major pathogenic mechanisms, are still less understood. In this study, we hypothesized that sestrin2 may protect hippocampal CA1 neurons against transient global ischemia (TGI)-induced apoptosis by regulating RpS6 phosphorylation in rats. We found that sestrin2 expression was progressively increased in the hippocampal CA1 subfield 1–48 h after TGI, reaching the maximal level at 24 h, and declined thereafter. Further, an increased extent of RpS6 phosphorylation, but not total RpS6 protein level, was observed in the hippocampal CA1 subfield after TGI. The sestrin2 siRNA, which substantially blocked the expression of TGI-induced sestrin2, also abolished RpS6 phosphorylation. TGI with reperfusion may induce oxidative stress with the resultant formation of 8-hydroxy-deoxyguanosine (8-OHdG). We found that sestrin2 siRNA further augmented the formation of 8-OHdG induced by TGI with reperfusion for 4 h. Consistently, sestrin2 siRNA also enhanced apoptosis induced by TGI with reperfusion for 48 h based on the analysis of DNA fragmentation by agarose gel electrophoresis, DNA fragmentation sandwich ELISA, and the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay. Together these findings indicated that TGI-induced sestrin2 expression contributed to RpS6 phosphorylation and neuroprotection against ischemic injury in the hippocampal CA1 subfield.

Levetiracetam in the Treatment of Epileptic Seizures After Liver Transplantation

After liver transplantation, patients may develop seizures or epilepsy due to a variety of etiologies. The ideal antiepileptic drugs for these patients are those with fewer drug interactions and less hepatic toxicity. In this study, we present patients using levetiracetam to control seizures after liver transplantation. We retrospectively enrolled patients who received levetiracetam for seizure control after liver transplantation. We analyzed the etiology of liver failure that required liver transplantation, etiology of the seizures, outcomes of seizure control, and the condition of the patient after follow-up at the outpatient department. Hematological and biochemical data before and after the use of levetiracetam were also collected. Fifteen patients who received intravenous or oral levetiracetam monotherapy for seizure control after liver transplantation were enrolled into this study. All of the patients remained seizure-free during levetiracetam treatment. Two patients died during the follow-up, and the other 13 patients were alive at the end of the study period and all were seizure-free without neurological sequelae that interfered with their daily activities. No patients experienced liver failure or rejection of the donor liver due to ineffective immunosuppressant medications. The dosage of immunosuppressants did not change before and after levetiracetam treatment, and there were no changes in hematological and biochemical data before and after treatment. Levetiracetam may be a suitable antiepileptic drug for patients who undergo liver transplantation due to fewer drug interactions and a favorable safety profile.

Zonisamide: Review of Recent Clinical Evidence for Treatment of Epilepsy

Zonisamide is an orally administered antiepileptic drug that was first approved for clinical use in Japan in 1989. Since then, it has been licensed in Korea for a broad spectrum of epilepsies in adults and children, and in the USA for adjunctive therapy of adults with partial seizures, and in Europe for monotherapy of adults with newly diagnosed partial seizures and adjunctive therapy of adults and adolescents and children aged ≥6 years with partial seizures with or without secondary generalization. Zonisamide is a benzisoxazole derivative with a unique chemical structure, predictable dose-dependent pharmacokinetics, and multiple complementary mechanisms of action. Treatment with zonisamide is well tolerated and is not known to be associated with clinically significant drug-drug interactions, including with oral contraceptives or other antiepileptic drugs. There have been >2 million patient-years of experience with zonisamide for treatment of epilepsy, and this drug has International League Against Epilepsy level A evidence for efficacy/effectiveness as initial monotherapy for adults with partial-onset seizures. This review presents the evidence for zonisamide across the spectrum of epilepsy, with emphasis on real-world clinical practice and special populations of patients (children, elderly patients, and women of childbearing age) who are likely to be treated in daily clinical practice.

Antithyroid Antibodies Are Implicated in Epileptogenesis of Adult Patients With Epilepsy

Antithyroid antibodies (Abs) are associated with epilepsy in steroid-responsive encephalopathy, but have been rarely studied in unselected epilepsy patients. This study aimed to characterize the prevalence and associated factors of antithyroid Abs and other auto-Abs in adult patients with epilepsy.Epilepsy patients without autoimmune disorders were surveyed for antinuclear antibody (ANA), anti-β2 glycoprotein 1 antibody (aβ2GP1), anticardiolipin IgG Ab, antimicrosomal antibody (AMA), antithyroglobulin antibody (ATA), and thyroid function test.Of 319 patients, 75 (23.5%) were positive for at least 1 Ab. The most common Ab was anticardiolipin antibody (aCL) (30/319, 9.4%), followed by AMA (24/319, 7.5%), ANA (18/319, 5.6%), aβ2GP1 (18/319, 6.5%), and ATA (6/319, 3.25%). Antimicrosomal Abs were significantly more frequent in patients who were female, older at disease onset, older at the time of study, and had unknown seizure etiology. The presence of aCL was significantly associated with more frequent seizures. Most patients with antithyroid Ab were female and had focal seizures with unknown etiology.The association of different auto-Abs with different factors suggests that they may have different roles in adult patients with epilepsy. Recurrent seizures and certain antiepileptic medications may cause the production of aCL. The role of antithyroid Abs in adult focal epilepsy with unknown cause, especially in females, warrants further evaluation because of the potential implications on treatment.

Roles of PTEN-induced putative kinase 1 and dynamin-related protein 1 in transient global ischemia-induced hippocampal neuronal injury

Recent studies showed that increased mitochondrial fission is an early event of cell death during cerebral ischemia and dynamin-related protein 1 (Drp1) plays an important role in mitochondrial fission, which may be regulated by PTEN-induced putative kinase 1 (PINK1), a mitochondrial serine/threonine-protein kinase thought to protect cells from stress-induced mitochondrial dysfunction and regulate mitochondrial fission. However, the roles of PINK1 and Drp1 in hippocampal injury caused by transient global ischemia (TGI) remain unknown. We therefore tested the hypothesis that TGI may induce PINK1 causing downregulation of Drp1 phosphorylation to enhance hippocampal neuronal survival, thus functioning as an endogenous neuroprotective mechanism. We found progressively increased PINK1 expression in the hippocampal CA1 subfield1-48 h following TGI, reaching the maximal level at 4 h. Despite lack of changes in the expression level of total Drp1 and phosphor-Drp1 at Ser637, TGI induced a time-dependent increase of Drp1 phosphorlation at Ser616 that peaked after 24 h. Notably, PINK1-siRNA increased p-Drp1(Ser616) protein level in hippocampal CA1 subfield 24 h after TGI. The PINK1 siRNA also aggravated the TGI-induced oxidative DNA damage with an increased 8-hydroxy-deoxyguanosine (8-OHdG) content in hippocampal CA1 subfield. Furthermore, PINK1 siRNA also augmented TGI-induced apoptosis as evidenced by the increased numbers of TUNEL-positive staining and enhanced DNA fragmentation. These findings indicated that PINK1 is an endogenous protective mediator vital for neuronal survival under ischemic insult through regulating Drp1 phosphorylation at Ser616.

Mitochondrial transfer from Wharton's jelly-derived mesenchymal stem cells to mitochondria-defective cells recaptures impaired mitochondrial function

Adult mesenchymal stem cell (MSC)-conducted mitochondrial transfer has been recently shown to rescue cellular bioenergetics and prevent cell death caused by mitochondrial dysfunction. Wharton's jelly-derived MSCs (WJMSCs) harvested from postpartum umbilical cords are an accessible and abundant source of stem cells. This study aimed to determine the capability of WJMSCs to transfer their own mitochondria and rescue impaired oxidative phosphorylation (OXPHOS) and bioenergetics caused by mitochondrial DNA defects. To do this, WJMSCs were co-cultured with mitochondrial DNA (mtDNA)-depleted ρ(0) cells and the recapture of mitochondrial function was evaluated. WJMSCs were shown to be capable of transferring their own mitochondria into ρ(0) cells and underwent interorganellar mixture within these cells. Permissive culture media (BrdU-containing and pyruvate- and uridine-free) sieved out a survival cell population from the co-cultured WJMSCs (BrdU-sensitive) and ρ(0) cells (pyruvate/uridine-free). The survival cells had mtDNA identical to that of WJMSCs, whereas they expressed cellular markers identical to that of ρ(0) cells. Importantly, these ρ(0)-plus -WJMSC-mtDNA (ρ(+W)) cells recovered the expression of mtDNA-encoded proteins and exhibited functional oxygen consumption and respiratory control, as well as the activity of electron transport chain (ETC) complexes I, II, III and IV. In addition, ETC complex V-inhibitor-sensitive ATP production and metabolic shifting were also recovered. Furthermore, cellular behaviors including attachment-free proliferation, aerobic viability and OXPHOS-reliant cellular motility were also regained after mitochondrial transfer by WJMSCs. The therapeutic effect of WJMSCs-derived mitochondrial transfer was able to stably sustain for at least 45 passages. In conclusion, this study suggests that WJMSCs may serve as a potential therapeutic strategy for diseases linked to mitochondrial dysfunction through the donation of healthy mitochondria to cells with genetic mitochondrial defects.

Risk factors of hyperammonemia in patients with epilepsy under valproic acid therapy

Hyperammonemia has been reported to be associated with patients who receive valproic acid (VPA) therapy. This study aimed to determine the risk factors for hyperammonemia in patients with epilepsy treated with VPA. One hundred and fifty-eight adult patients with epilepsy aged older than 17 years who received VPA therapy were enrolled into this study. Blood samples were taken during the interictal state and analyzed for the blood level of ammonia. Statistical analysis was conducted between different groups of patients. The results showed that the frequency of hyperammonemia associated with VPA therapy was 27.8% (ammonia level >93 µg/dL), and 5.1% of the patients had severe hyperammonemia (ammonia level >150 µg/dL). The blood ammonia level was significantly correlated with the dosage of VPA and the plasma concentration of VPA. An increase of 1 mg in the dosage of VPA increased the risk of hyperammonemia by 0.1%. In addition, combination treatment with liver enzyme inducing antiepileptic drugs (AEDs) and antipsychotic drugs increased the risk of hyperammonemia. In conclusion, the use of VPA in adult patients with epilepsy was associated with a dose-dependent increase in blood concentrations of ammonia. Combination treatment with liver enzyme-inducing AEDs and antipsychotic drugs increased the risk of VPA-induced hyperammonemia. Most of the patients with VPA-induced hyperammonemia were asymptomatic; however, if patients taking VPA present with symptoms such as nausea, fatigue, somnolence, ataxia, and consciousness disturbance, the blood ammonia level should be measured.

Cardiac transplantation and concomitant coronary artery bypass grafting: our experiences in 11 cases

INTRODUCTION

The shortage of donor hearts for transplantation could be alleviated by including the hearts of older donors. Previous literature revealed similar early and medium-term survival outcomes compared with those of younger donors. This study presents our experience with patients who underwent orthotopic heart transplantation and concomitant coronary artery bypass grafting at our institution.

METHODS

We present our experience with 11 patients with end-stage cardiomyopathy (8 men and 3 women) undergoing orthotopic heart transplantation and concomitant coronary artery bypass grafting from September 2002 to November 2011 at our institute.

RESULTS

All 11 donor organs would otherwise have been rejected, depriving potential recipients of organ transplantation. Two patients received concurrent 2-coronary-artery bypass, and the other 9 patients received concurrent single-coronary-artery bypass during orthotopic heart transplantation. All patients had an uneventful postoperative course, with follow-up completed 3 to 128 months after cardiac transplantation and concomitant coronary artery bypass grafting surgery.

CONCLUSIONS

Our experiences suggest that donor hearts requiring coronary artery bypass grafting, which form a small but significant donor subgroup, can be used effectively and safely when matched to the recipients' age and medical condition.

Non-cephalosporin-susceptible, glucose non-fermentative Gram-negative bacilli meningitis in post-neurosurgical adults: clinical characteristics and therapeutic outcome

OBJECTIVE

The clinical and laboratory characteristics of non-cephalosporin-susceptible (non-CS) glucose non-fermentative Gram-negative (G(-)) infections in adults with postneurosurgical meningitis are rarely examined solely in the literature.

METHODS

The data of 28 post-neurosurgical adults meningitis with glucose non-fermentative G(-) infections, collected during a study period of 5 years (2006-2010), were reviewed. The clinical and laboratory data between the non-cephalosporin-susceptible groups and the cephalosporin-susceptible groups were compared.

RESULTS

A total of 30 G(-) strains were collected from the 28 enrolled cases. Among the implicated glucose non-fermentative G(-) strains, 18 strains, belonging to 17 cases, were non-CS. Among the 18 non-cephalosporin-susceptible strains, Acinetobacter spp. (39%, 7/18) was the most common, followed by Pseudomonas spp. (22%, 4/18), Stenotrophomonas maltophilia (22%, 4/18) and Elizabethkingia meningoseptica (11%, 2/18). With a comparative analysis, there were no significant difference between the non-cephalosporin-susceptible and cephalosporin-susceptible glucose non-fermentative G(-) groups. The clinical and laboratory data were also of no statistical significance between the fatal (n=4) and non-fatal (n=13) non-cephalosporin-susceptible groups.

CONCLUSION

Sixty percent (18/30) of implicated glucose non-fermentative G(-) strains of post-NS meningitis in adults are non-cephalosporin-susceptible. Among the non-cephalosporin-susceptible glucose non-fermentative G(-) strains, Acinetobacter spp., Pseudomonas spp., S. maltophilia and E. meningoseptica are the commonly implicated pathogens, and their emergence in this specific group of meningitis has caused a therapeutic dilemma. The clinical manifestations of non-cephalosporin-susceptible glucose non-fermentative G(-) meningitis were not unique; therefore, only bacterial culture and antimicrobial susceptibility test are the methods for identification confirmation.

Heat shock protein 70 protects against seizure-induced neuronal cell death in the hippocampus following experimental status epilepticus via inhibition of nuclear factor-κB activation-induced nitric oxide synthase II expression

Status epilepticus induces subcellular changes that may eventually lead to neuronal cell death in the hippocampus. Based on an animal model of status epilepticus, our laboratory showed previously that sustained hippocampal seizure activity activates nuclear factor-κB (NF-κB) and upregulates nitric oxide synthase (NOS) II gene expression, leading to apoptotic neuronal cell death in the hippocampus. The present study examined the potential modulatory role of heat shock protein 70 (HSP70) on NF-κB signaling in the hippocampus following experimental status epilepticus. In Sprague-Dawley rats, kainic acid (KA) was microinjected unilaterally into the hippocampal CA3 subfield to induce prolonged bilateral seizure activity. Expression of HSP70 was elevated as early as 1h after the elicitation of sustained seizure activity, followed by a progressive elevation that peaked at 24h. Pretreatment with an antisense oligonucleotide against hsp70 decreased the HSP70 expression, and significantly augmented IκB kinase (IKK) activity and phosphorylation of IκBα, alongside enhanced nuclear translocation and DNA binding activity of NF-κB in the hippocampal CA3 neurons and glial cells. These cellular events were followed by enhanced upregulation of NOS II and peroxynitrite expression 3h after sustained seizure activity that led to an increase of caspase-3 and DNA fragmentation in the hippocampal CA3 neurons 7days after experimental status epilepticus. We concluded that HSP70 protects against apoptotic cell death induced by NF-κB activation and NOS II-peroxynitrite signaling cascade in the hippocampal CA3 and glial cells following experimental status epilepticus via suppression of IKK activity and deactivation of IκBα.

Limits on spin-independent couplings of WIMP dark matter with a p-type point-contact germanium detector

We report new limits on a spin-independent weakly interacting massive particle (WIMP)-nucleon interaction cross section using 39.5 kg days of data taken with a p-type point-contact germanium detector of 840 g fiducial mass at the Kuo-Sheng Reactor Neutrino Laboratory. Crucial to this study is the understanding of the selection procedures and, in particular, the bulk-surface events differentiation at the sub-keV range. The signal-retaining and background-rejecting efficiencies were measured with calibration gamma sources and a novel n-type point-contact germanium detector. Part of the parameter space in the cross section versus WIMP-mass implied by various experiments is probed and excluded.

Clinical characteristics of Stenotrophomonas maltophilia meningitis in adults: a high incidence in patients with a postneurosurgical state, long hospital staying and antibiotic use

OBJECTIVE

Stenotrophomonas (S.) maltophilia is an uncommon pathogen of adult bacterial meningitis (ABM).

METHODS

The clinical characteristics of six S. maltophilia ABM cases, collected during a study period of nine years (2001-2009) were included. In the related literature, 13 S. maltophilia ABM cases were reported, and their clinical data were also collected.

RESULTS

The 19 S. maltophilia ABM cases included 11 men and 8 women, aged 28-70 years. Of these 19 cases, 89.5% (17/19) had underlying neurosurgical (NS) conditions as the preceding event. Before the development of S. maltophilia ABM, 52.6% (10/19) of them had long stays in hospital and 63.2% (12/19) had undergone antibiotic treatment. Among the implicated S. maltophilia cases, three strains were found to have a resistance to sulfamethoxazole-trimethoprim (SMZ-TMP). Two of our five cases had resistant strains to levofloxacin. Among the antibiotics chosen for treatment, SMZ-TMP was the most common followed by quinolone (ciprofloxacin, levofloxacin, moxifloxacin). The therapeutic results showed 2 cases expired while the other 17 cases survived.

CONCLUSIONS

S. maltophilia ABM usually develops in patients with a preceding neurosurgical condition, a long hospital stay and antibiotic use. SMZ-TMP and quinolones, especially the ciprofloxacin, are the major antibiotic used. This study also shows the emergence of clinical S. maltophilia strains which are not susceptible to SMZ-TMP and quinolones and this development may pose a more serious threat in the near future because treatment options may become depleted and limited despite the mortality rate of this specific group of ABM not being high at this time.

Mitochondrial DNA coding and control region variants as genetic risk factors for type 2 diabetes

Both the coding and control regions of mitochondrial DNA (mtDNA) play roles in the generation of diabetes; however, no studies have thoroughly reported on the combined diabetogenic effects of variants in the two regions. We determined the mitochondrial haplogroup and the mtDNA sequence of the control region in 859 subjects with diabetes and 1,151 normoglycemic control subjects. Full-length mtDNA sequences were conducted in 40 subjects harboring specific diabetes-related haplogroups. Multivariate logistic regression analysis with adjustment for age, sex, and BMI revealed that subjects harboring the mitochondrial haplogroup B4 have significant association with diabetes (DM) (odds ratio [OR], 1.54 [95% CI 1.18-2.02]; P < 0.001), whereas subjects harboring D4 have borderline resistance against DM generation (0.68 [0.49-0.94]; P = 0.02). Upon further study, we identified an mtDNA composite group susceptible to DM generation consisting of a 10398A allele at the coding region and a polycytosine variant at nucleotide pair 16184-16193 of the control region, as well as a resistant group consisting of C5178A, A10398G, and T152C variants. The OR for susceptible group is 1.31 (95% CI 1.04-1.67; P = 0.024) and for the resistant group is 0.48 (0.31-0.75; P = 0.001). Our study found that mtDNA variants in the coding and control regions can have combined effects influencing diabetes generation.