Voice Outcome After Cold Knife Surgery According to the Characteristics of Vocal Fold Polyp

PURPOSE

Voice change is one of the major symptoms in patients with vocal fold polyp. As a result, phonomicrosurgery is commonly required in these patients. Since voice outcomes after polyp treatment can be variable according to polyp characteristics, we aimed to investigate the predicting factors of postoperative voice improvements in terms of polyp characteristics in patients with vocal fold polyp who underwent cold knife surgery.

MATERIALS AND METHODS

A total of 77 patients who were diagnosed with vocal fold polyp and underwent phonomicrosurgery with cold knife instruments. The polyp characteristics of color, size, shape, and location were evaluated at baseline. Acoustic and aerodynamic analyses, voice handicap index questionnaire and grade, roughness, breathiness, asthenia, strain scale were evaluated at baseline and 6 weeks after surgery.

RESULTS

All values of postoperative voice parameters improved after cold knife surgery. (P < 0.05) In patient with an organized vocal fold polyp, less improvement in postoperative values of maximum phonation time were observed. (P < 0.05) Likewise, less improvement of voice handicap index questionnaire score and grade, roughness, breathiness, asthenia, strain scale after surgery was shown in organized vocal fold polyp. (P < 0.05) CONCLUSIONS: Among the various polyp characteristics, the organized polyp was significantly related to relatively less improvement of objective and subjective voice parameters after surgery. These polyp characteristics would help to predict postoperative voice improvement and plan for personalized treatment in patients with vocal fold polyp.

Bacteriology and trends of antimicrobial resistance of Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus in otitis media: A retrospective data analysis

OBJECTIVES

Otitis media (OM) has a high prevalence worldwide and the treatment is crucial because hearing loss in children can lead to growth disorders such as language development disorders. The aim of this study is to analyse the changes in bacterial strains and the trends of antibiotic susceptibility in otitis media with effusion (OME), chronic otitis media (COM) and cholesteatomatous otitis media (Chole OM).

DESIGN

This retrospective study involved 2926 patients diagnosed with OME, COM, or Chole OM between January 2000 and December 2020. The clinical data were collected and analysed through chart review from May 2021 to July 2021.

SETTING

Two tertiary medical centres.

PARTICIPANTS

The 2926 OM patients.

MAIN OUTCOMES AND MEASURES

An otorrhea sample was collected on the first day of their hospital visit. Middle ear fluid samples for bacterial culture and antibiotics susceptibility test were collected from patients during middle ear surgery, including ventilation tube insertion. In each type of OM, the distribution of bacterial strains in the 2000s and the 2010s was compared. In addition, changes in the detection rate of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (PA) and trends in their antibiotic susceptibility over the last 10 years were analysed.

RESULTS

The most frequently detected bacterial strains in OME, COM and Chole OM over the study period were coagulase-negative Staphylococcus (CNS) (29.6%), MRSA (24.1%), and PA (20.1%). Compared to the 2000s, the proportion of non-typable Haemophilus influenzae in OME and MRSA in COM increased in the 2010s (27.4%-31.6% and 1.5%-29.5%, respectively). In total three types of OM, although there was no significant trend of change in detection rates of MRSA, PA, and multidrug resistant-P. aeruginosa (MDR-PA) during the last 10 years, resistance to the Quinolone class of MRSA and PA tended to increase (P < .05).

CONCLUSIONS

The composition of bacterial strains in each types of OM has changed over the past 20 years. Additionally, the antibiotic resistance of MRSA and PA has increased in the last decade. Therefore, when using empirical antibiotics in necessary situations, it is necessary to change to an appropriate antibiotic through a bacterial culture test and antimicrobial susceptibility test.

Comparison of Endoplasmic Reticulum Stress Messenger Ribonucleic Acid Expression Between Chronic Otitis Media With and Without Cholesteatoma

BACKGROUND

We evaluated and compared the role of endoplasmic reticulum stress in chronic otitis media with cholesteatoma and chronic otitis media without cholesteatoma.

METHODS

The messenger ribonucleic acid expression of endoplasmic reticulum stress was measured and compared between chronic otitis media with cholesteatoma and chronic otitis media without cholesteatoma according to the presence or absence of bacteria, type of hearing loss, ossicle destruction, and facial canal dehiscence.

RESULTS

The expression of immunoglobulin heavy chain-binding protein messenger ribonucleic acid was higher in the chronic otitis media without cholesteatoma group than in the chronic otitis media with cholesteatoma group, and Protein kinase RNA (PKR)-like endoplasmic reticulum kinase and activating transcription factor 6 messenger ribonucleic acid expression were higher in the chronic otitis media with cholesteatoma group than in the chronic otitis media without cholesteatoma group.

CONCLUSION

Endoplasmic reticulum stress messenger ribonucleic acids were expressed in both chronic otitis media with cholesteatoma and chronic otitis media without cholesteatoma. The levels of expression of endoplasmic reticulum stress messenger ribonucleic acids differed according to clinical features, suggesting that different endoplasmic reticulum stress pathways are involved in the pathophysiology of different types of chronic otitis media.

Molecular Genetic Etiology and Revisiting the Middle Ear Surgery Outcomes of Branchio-Oto-Renal Syndrome: Experience in a Tertiary Referral Center

OBJECTIVES

To explore the phenotypes and genotypes of patients with branchio-oto-renal (BOR) and branchio-otic (BO) syndrome, and to analyze the middle ear surgery outcomes qualitatively and quantitatively, proposing a factor usefully prognostic of surgical outcomes.

STUDY DESIGN

Retrospective cohort study.

SETTING

Tertiary referral center.

PATIENTS

Eighteen patients with BOR/BO syndrome in 12 unrelated Korean families.

INTERVENTION

Middle ear surgery, including either stapes surgery or ossicular reconstruction.

MAIN OUTCOME MEASURE

Clinical phenotypes, genotypes, and middle ear surgery outcomes.

RESULTS

Eight probands (66.7%) were confirmed genetically; the condition segregated as a dominant or de novo trait. Six EYA1 heterozygous variants were identified by exome sequencing and multiplex ligation-dependent probe amplification. All variants were pathogenic or likely pathogenic based on the ACMG/AMP guidelines. Two novel EYA1 frameshift variants (p.His373Phefs*4 and p.Gln543Asnfs*90) truncating a highly conserved C-terminal Eya domain were identified, expanding the genotypic spectrum of EYA1 in BOR/BO syndrome. Remarkably, middle ear surgery was individualized to ensure optimal audiological outcomes and afforded significant audiological improvements, especially in BOR/BO patients without enlarged vestibular aqueducts (EVAs). A significant difference in air-bone gap closure after middle ear surgery was noted between the two groups even after adjusting for confounders: -20.5 dB in ears without EVAs (improvement) but 0.8 dB in ears with EVAs (no change or deterioration). Furthermore, the success rate was significantly associated with the absence of EVA.

CONCLUSIONS

The results of this study were against the notion that middle ear surgery is always contraindicated in patients with BOR/BO syndrome, and an EVA could be a negative prognostic indicator of middle ear surgery in BOR/BO patients. This may aid to determine the strategy of audiological rehabilitation in patients with BOR/BO syndrome.

Effect of closing material on hearing rehabilitation in stapedectomy and stapedotomy: A finite element analysis

Stapedotomy or stapedectomy operations are often performed to treat otosclerosis. During the operation, the space created by bone removal is usually filled with a closing material such as fat or fascia. In this study, the effect of the Young's modulus of the closing material on the hearing level was investigated through the 3D finite element model of a human head including auditory periphery. The Young's moduli of the closing material used to implement stapedotomy and stapedectomy conditions in the model were varied from 1 kPa to 24 MPa. The results showed that the hearing level improved when the closing material was more compliant after stapedotomy. Therefore, when the stapedotomy was performed using fat whose Young's modulus is lowest among the potential closing materials, the hearing level recovered the best among all simulated cases. On the other hand, in stapedectomy, the Young's modulus did not have the linear relationship between the hearing level and the compliance of the closing material. Hence, the Young's modulus causing the best hearing rehabilitation in stapedectomy was found not at the end of the investigated range of Young's modulus but somewhere in the middle of the given range.

Prognostic Factors Associated with Recovery from Recurrent Idiopathic Sudden Sensorineural Hearing Loss: Retrospective Analysis and Systematic Review

Although idiopathic sudden sensorineural hearing loss (ISSNHL) is uncommon, recurrent ISSNHL is even rarer. The knowledge about factors associated with patient recovery from recurrent episodes is needed to counsel and treat the patients. Medical records of patients admitted for high dose oral steroid therapy for recurrent ISSNHL between January 2009 and December 2021 were reviewed. Their demographic and clinical characteristics, co-morbid symptoms, and audiologic results were analyzed. The 38 patients admitted for treatment of recurrent ISSNHL included 14 men and 24 women. Recovery rates after the first and recurrent episodes of ISSNHL were 78.9% and 63.2%, respectively. Patients who recovered after recurrent episodes showed significantly higher rates of ear fullness symptoms and early treatment onset than those who did not recover (p < 0.05 each). Of the 30 patients who recovered after the first episode, those who had ear fullness symptoms (p < 0.05, odds ratio (OR) 0.1, 95% confidence interval (CI) 0.01−0.76) and who showed a lower initial hearing threshold (p < 0.05, OR 1.06, 95% CI 1.01−1.12) during the recurrent episode showed significantly better or similar recovery than after the first episode. Ear fullness symptoms and less initial hearing loss were associated with a more favorable prognosis after intial than after recurrent ISSNHL.

Relationship between toll-like receptor expression in the distal facial nerve and facial nerve recovery after injury

Objectives: This study aimed to determine whether toll-like receptor expression patterns differ in the distal facial nerve during recovery after crushing and cutting injuries. Methods: Adult male Sprague-Dawley rats underwent crushing or cutting injury of the unilateral facial nerve. Their whisker movement and blink reflex were examined. Western blotting was performed with the normal nerve on the left side and the damaged nerve on the right side, four days, 14 days, and 3 months after injury. Results: The scores of whisker movements and blink reflex in the crushing group showed improvements, while the score of the cutting group was significantly lower at 14 days and 3 months (p < 0.05). Western blotting showed that TLRs 11 and 13 increased in the crushing group, and TLRs 1, 2, 3, 4, 5, 8, 10, 11, 12, and 13 increased in the cutting group after 14 days (p < 0.05). After 3 months, TLRs 10 and 11 increased in the crushing group, and TLRs 1, 4, 5, 8, 11, and 12 increased in the cutting group (p < 0.05). Conclusion: TLRs 1, 4, 5, 8, and 12 are related to nerve degeneration after facial nerve injury, and TLRs 10, 11, and 13 are related to recovery from facial palsy.

Expression of endoplasmic reticulum stress mRNAs in otitis media

BACKGROUND

Endoplasmic reticulum (ER) stress is a cellular defense mechanism that occurs when ER function is impaired.

OBJECTIVE

This study was designed to evaluate the expression of major mRNAs of ER stress in patients with otitis media with effusion (OME), chronic otitis media (COM), and COM with cholesteatoma (CholeOM).

MATERIAL AND METHODS

Specimens were collected during surgery from patients with OME, COM, and CholeOM, and the levels of ER stress mRNAs measured by real-time polymerase chain reaction. Levels of ER stress mRNAs were compared in the three groups and correlated with clinical findings and pus culture results.

RESULTS

The level of CHOP mRNA was higher, and the levels of sXBP1 and ATF6 mRNAs lower, in the OME than in the other two groups (p < .05 each). Evaluation of bacterial pus culture negative patients showed that the level of ATF6 mRNA was higher in the CholeOM than in the other two groups (p < .05), whereas evaluation of bacterial pus culture positive patients showed that the level of CHOP mRNA was higher in the OME than in the other groups (p < .05).

CONCLUSIONS AND SIGNIFICANCE

ER stress may be involved in the pathophysiology of OM and the levels of ER stress mRNAs were expressed differently in each type of otitis media according to bacterial culture test results.

Analysis of Chronic Tinnitus in Noise-Induced Hearing Loss and Presbycusis

Introduction: The most frequent causes of tinnitus associated with hearing loss are noise-induced hearing loss and presbycusis. The mechanism of tinnitus is not yet clear, although several hypotheses have been suggested. Therefore, we aimed to analyze characteristics of chronic tinnitus between noise-induced hearing loss and presbycusis. Materials and Methods: This paper is a retrospective chart review and outpatient clinic-based study of 248 patients with chronic tinnitus from 2015 to 2020 with noise-induced or presbycusis. Pure tone audiometry (PTA), auditory brainstem response (ABR), distortion product otoacoustic emissions (DPOAE), transient evoked otoacoustic emissions (TEOAE), and tinnitograms were conducted. Results: PTA showed that hearing thresholds at all frequencies were higher in patients with noise-induced hearing loss than the presbycusis group. ABR tests showed that patients with presbycusis had longer wave I and III latencies (p < 0.05 each) than patients with noise-induced hearing loss. TEOAE tests showed lower values in patients with noise-induced hearing loss than presbycusis at 1.5, 2, 3, and 4 kHz (p < 0.05 each). DPOAE tests showed that response rates in both ears at 1.5, 2, and 3 kHz were significantly higher in patients with presbycusis than noise-induced hearing loss (p < 0.05 each). Discussion: This study showed that hearing thresholds were higher, the loudness of tinnitus was smaller, and the degree of damage to outer hair cells was lower in patients with presbycusis than with noise-induced hearing loss. Moreover, wave I and III latencies were more prolonged in patients with presbycusis despite their having lower hearing thresholds. These phenomena may reflect the effects of aging or degeneration of the central nervous system with age. Further studies are needed to evaluate the etiologies of tinnitus.

Expression of endoplasmic reticulum stress-related mRNA in otitis media with effusion

OBJECTIVES

The endoplasmic reticulum (ER) is an intracellular organelle involved in the synthesis and secretion of proteins. The ER stress response, which protects cells from cytotoxic proteins such as unfolded proteins, is related to several diseases including inflammation. In this study, we investigated the effect of ER stress on the pathophysiology of otitis media with effusion (OME).

METHODS

Thirty-nine pediatric patients who were diagnosed with OME and underwent ventilation tube insertion were enrolled in this study. Exudate from the middle ear cavity was collected through ventilation insertion, and ER stress gene expression was analyzed via real-time polymerase chain reactions(PCR).

RESULTS

There were no significant differences in ER stress-related mRNA expression between effusion culture-positive and culture-negative groups (p > 0.05). Expression of the C/EBP-homologous protein (CHOP) was higher in the otitis-prone group than in the non-otitis-prone group (p < 0.05). The most common type of fluid was mucoid, and inositol-requiring enzyme 1α expression was higher in serous fluid than in mucoid, mucopurulent, or purulent fluid (p < 0.05).

CONCLUSIONS

Endoplasmic reticulum stress-related responses are activated in pediatric OME patients, and specific ER-stress related pathways are related to both the characteristics of fluid and the frequency of OME. Thus, ER stress-related responses affect the pathophysiology of OME in pediatric OME patients.

Cutoff value of serum procalcitonin as a diagnostic biomarker of infection in end-stage renal disease patients

BACKGROUND/AIMS

Serum procalcitonin (PCT) levels are low in healthy individuals but are elevated in patients with a serious bacterial infection or sepsis. In this study, we examined the ability of serum PCT concentration to diagnose infections in end-stage renal disease (ESRD) patients, and sought to determine an appropriate threshold level.

METHODS

Serum PCT levels were measured in ESRD patients on antibiotic therapy for a suspected bacterial infection (ESRD infection [iESRD] group, n = 21), and compared with those of ESRD patients on hemodialysis with no sign of infection (ESRD control [cESRD] group, n = 20).

RESULTS

The mean serum PCT concentration of the iESRD group was significantly higher than in the cESRD group (2.95 ± 3.67 ng/mL vs. 0.50 ± 0.49 ng/mL, p = 0.006), but serum PCT concentrations did not correlate with severity of infection. The optimized threshold level derived for serum PCT was 0.75 ng/mL, rather than the currently used 0.5 ng/mL; this threshold demonstrated a sensitivity and specificity of 76.2% and 80.0% for infection and 100% and 60.6% for systemic inflammatory response syndrome, respectively, compared with the cutoff of 0.5 ng/mL.

CONCLUSIONS

This study suggests that serum PCT at a cutoff value of 0.75 ng/mL is an appropriate indicator of infection in ESRD patients.

High resolution MRI difference between moyamoya disease and intracranial atherosclerosis

BACKGROUND AND PURPOSE

Along with intracranial atherosclerotic disease (ICAD), moyamoya disease (MMD) is the most common cause of middle cerebral artery (MCA) occlusion in Asians. Although they have differing vascular wall pathologies, conventional angiographic evaluation methods cannot easily differentiate MMD from ICAD in certain situations, such as in young patients with atherosclerotic risk factors. High resolution magnetic resonance imaging (HR-MRI) findings for the diseased segments of MCAs in MMD and symptomatic ICAD were compared to further elucidate differences in arterial wall changes.

METHODS

Angiographically confirmed patients, 12 MMD and 20 ICAD, who suffered a stroke due to MCA occlusion were recruited and underwent HR-MRI. The size of the outer diameter and other stenotic vessel wall characteristics revealed by HR-MRI, including enhancement, eccentricity and other lesion patterns, were analyzed by two independent reviewers in a blind fashion.

RESULTS

MMD patients were younger than ICAD patients (32.92 ± 11.08 years vs. 51.85 ± 11.97 years; mean ± SD) and displayed a smaller outer diameter in the stenotic portion (1.61 ± 0.43 mm for MMD vs. 3.03 ± 0.53 mm for ICAD, P < 0.0001). Eccentric lesions (three of 12 in MMD vs. 19 of 20 in ICAD, P < 0.0001) and focal enhancements in diseased areas (two of seven in MMD vs. 13 of 17 in ICAD, P = 0.061) were less common in MMD cases.

CONCLUSIONS

Our HR-MRI findings show that MMD is associated with smaller, concentric occlusive lesions which are rarely enhanced compared with symptomatic ICAD, consistent with the results of previous pathological reports. HR-MRI may therefore have utility in differentiating MMD from ICAD.

Stroke recurrence patterns are predicted by the subtypes and mechanisms of the past, non-cardiogenic stroke

BACKGROUND AND PURPOSE

The association between past stroke subtypes and recurrent stroke subtypes in non-cardiogenic stroke remains unknown.

METHODS

Patients with ischaemic stroke who had a past history of large-artery disease (LAD) or small-artery disease (SAD) subtypes were assessed. LAD was subdivided into intracranial atherosclerosis (ICAS) and extracranial atherosclerosis (ECAS). LAD stroke mechanisms were categorized as artery-to-artery embolism, in situ thrombotic occlusion and local branch occlusion, while SAD was subdivided into lacunar infarction (LI) and branch atheromatous disease (BAD) on the basis of magnetic resonance imaging findings. The relationship between past and current strokes was analyzed.

RESULTS

Among the 202 patients enrolled, the LAD group (n = 111) had 64 and 47 patients with ICAS and ECAS, and the SAD group (n = 91) had 63 and 28 patients with LI and BAD, respectively, at the time of past stroke. Patients with LAD developed LAD-associated strokes most often (n = 99, 89.2%), and patients with SAD developed SAD most often (n = 69, 75.8%; P < 0.001). Patients with ICAS were more likely to develop ICAS later (n = 46, 79.3%), whereas those with ECAS developed ECAS more often (n = 31, 75.6%; P < 0.001). Patients with ICAS presenting with artery-to-artery embolism more often developed artery-to-artery embolism later (n = 26, 72.2%), whereas those with local branch occlusion developed recurrent local branch occlusion most often (n = 10, 66.7%, P = 0.005). In the SAD group, patients with BAD developed LAD more frequently than the LI group (n = 11, 39.3% vs. n = 9, 14.3%, P = 0.022).

CONCLUSIONS

The subtypes and mechanisms of recurrent stroke are significantly influenced by those of the past stroke.

Porcine model to evaluate local tissue tolerability associated with subcutaneous delivery of protein

INTRODUCTION

The conversion from intravenous (IV) to subcutaneous (SC) delivery of biotherapeutics has increased in recent years. Some of the reasons for this shift in route of delivery are due to patient convenience, reduced adverse systemic effects, lack of a need for vascular access, and reduced cost of patient care, which ultimately lead to improved patient quality of life. One caveat to SC delivery is the limited volumes that can be administered at a single site and the associated local tolerability. To characterize factors that affect subcutaneous delivery of large volumes of therapeutic proteins, a porcine model was developed. Model endpoints included measurement of interstitial pressure, assessment of local skin visco-elasticity, and the qualitative assessment of local infusion sites.

METHODS

Immunoglobulin G (IgG) was subcutaneously infused into the abdominal region of Yucatan miniature swine. Changes in interstitial pressure were measured, using an in-line pressure transducer, during and after infusions. Additionally, pre- and post-infusion changes in local skin visco-elasticity were measured using a Cutometer®. Lastly, infusion sites were assessed for post-infusion local skin reactions such as erythema and swelling. Similar assessments were made following SC IgG delivery with the permeation enhancer recombinant human hyaluronidase PH20 (rHuPH20).

RESULTS

Subcutaneous infusions of IgG, in the presence of rHuPH20, significantly reduced average interstitial pressures by 55% during the infusion period and by 67% during the post-infusion period, compared to the control. Infusions in the presence of rHuPH20 also maintained better local skin elasticity as seen by a 42% increase in local skin pliability compared to the control. Finally, infusions with rHuPH20 resulted in an 80% reduction in swelling area compared to the control.

DISCUSSION

A large animal model was developed that incorporates both quantitative and qualitative assessment methods to aid in understanding SC delivery of proteins.

Blood-brain barrier disruption after cardiac surgery

BACKGROUND AND PURPOSE

CNS complications are often seen after heart surgery, and postsurgical disruption of the BBB may play an etiologic role. The objective of this study was to determine the prevalence of MR imaging-detected BBB disruption (HARM) and DWI lesions after cardiac surgery.

MATERIALS AND METHODS

All patients had an MRI after cardiac surgery. For half the patients (group 1), we administered gadolinium 24 hours after surgery and obtained high-resolution DWI and FLAIR images 24-48 hours later. We administered gadolinium to the other half (group 2) at the time of the postoperative scan, 2-4 days after surgery. Two stroke neurologists evaluated the images.

RESULTS

Of the 19 patients we studied, none had clinical evidence of a stroke or delirium at the time of the gadolinium administration or the scan, but 9 patients (47%) had HARM (67% in group 1; 30% in group 2; P = .18) and 14 patients (74%) had DWI lesions (70% in group 1; 78% in group 2; P = 1.0). Not all patients with DWI lesions had HARM, and not all patients with HARM had DWI lesions (P = .56).

CONCLUSIONS

Almost half the patients undergoing cardiac surgery have evidence of HARM, and three-quarters have acute lesions on DWI after surgery. BBB disruption is more prevalent in the first 24 hours after surgery. These findings suggest that MR imaging can be used as an imaging biomarker to assess therapies that may protect the BBB in patients undergoing heart surgery.

Rebamipide abolishes Helicobacter pylori CagA-induced phospholipase D1 expression via inhibition of NFκB and suppresses invasion of gastric cancer cells

Infection with cagA-positive Helicobacter pylori is a risk factor for the development of severe gastritis and gastric cancer (GC). CagA protein is injected into gastric epithelial cells and deregulates a variety of cellular signaling molecules. Phospholipase D (PLD) is elevated in many different types of human cancers and has been implicated as a critical factor in inflammation and carcinogenesis. In this study, we show that infection with cagA-positive H. pylori in GC cells significantly induces PLD1 expression via CagA-dependent activation of nuclear factor κB (NFκB). Interestingly, the level of PLD1 protein and IκBα phosphorylation is aberrantly upregulated in H. pylori-infected human GC tissues. Infection with cagA-positive H. pylori and expression of CagA enhanced the binding of NFκB to the PLD1 promoter, and two functional NFκB-binding sites were identified within the PLD1 promoter. Rebamipide, a mucosal-protective antiulcer agent, abolished H. pylori cagA-induced PLD1 expression via inhibition of binding of NFκB to the PLD1 promoter, and also inhibited PLD activity. Moreover, rebamipide suppressed H. pylori-induced matrix metalloproteinase-9, interleukin-8 and activation-induced cytidine deaminase expression as well as invasion of GC cells through downregulation of PLD1. Our data suggest that H. pylori cagA targets PLD1 for invasion of GC cells, and rebamipide might contribute to the antitumorigenic effect of GC cells via inhibition of the H. pylori cagA-NFκB-PLD1 signaling pathway.

The effect of intravenous ascorbic acid in hemodialysis patients with normoferritinemic anemia

Background

Hemodialysis (HD) patients with functional iron deficiency often develop resistance to recombinant human erythropoietin (rhEPO). Recent studies have shown that intravenous ascorbic acid (IVAA) administration could override rhEPO resistance in HD patients. This study was undertaken to test the effects of IVAA in HD patients with normoferritinemic functional iron deficiency accompanied by EPO-hyporesponsive anemia.

Methods

Fifty-eight HD patients with normoferritinemic anemia (between 100 and 500 μg/L) were included and divided into the control (N=25) and IVAA (N=33) groups. IVAA patients received 500 mg of IVAA with each dialysis session for 3 months and an additional 4-month follow-up after the end of the therapy.

Results

Twenty patients had a response to IVAA with a significant increase in hemoglobin level (Hgb>1.0 g/dL) and reduction of weekly rhEPO dosage compared with the control group after 3 months of treatment (P<0.05). Compared with non-responders, transferrin saturation (TSAT) was significantly decreased in the responders group (26±11 vs. 35±14%, P<0.05) on baseline data. There was a significant increase in serum iron and TSAT (baseline vs. 3 months, serum iron 57±22 vs. 108±22 μg/dL, TSAT 26±11 vs. 52±7%, P<0.05) and a decrease in serum ferritin (377±146 vs. 233±145 ng/mL, P<0.05) in the responders group (N=20), but no significant changes in the control and non-responders groups (N=13) at 3-month treatment.

Conclusion

IVAA can be a potent and effective adjuvant therapy for HD patients with rhEPO-resistant normoferritinemic anemia. In addition, IVAA can reduce the dosage of rhEPO for anemia correction.

Anaerobic digestion and co-digestion processes of vegetable and fruit residues: process and microbial ecology

This study evaluated the feasibility of methane production from fruit and vegetable waste (FVW) obtained from the central food distribution market in Mexico City using an anaerobic digestion (AD) process. Batch systems showed that pH control and nitrogen addition had significant effects on biogas production, methane yield, and volatile solids (VS) removal from the FVW (0.42 m(biogas)(3)/kg VS, 50%, and 80%, respectively). Co-digestion of the FVW with meat residues (MR) enhanced the process performance and was also evaluated in a 30 L AD system. When the system reached stable operation, its methane yield was 0.25 (m(3)/kg TS), and the removal of the organic matter measured as the total chemical demand (tCOD) was 65%. The microbial population (general Bacteria and Archaea) in the 30 L system was also determined and characterized and was closely correlated with its potential function in the AD system.

Gamma knife radiosurgery for medically refractory idiopathic trigeminal neuralgia

Gamma knife radiosurgery (GKS) has been generally considered as a viable therapeutic option for the management of medically refractory idiopathic trigeminal neuralgia (TN). We reviewed our experience with GKS in patients with TN. Between Feb 1996 and May 2006, 77 patients with medical refractory idiopathic TN were treated using GKS. Thirty-six patients who had undergone other previous procedures, previous GKS, or had brain stem lesion, atypical symptoms, were excluded from this study. Pain improvement was achieved in 38 of the patients with TN (pain response rate 92.7%). Twenty-three patients were pain free and 15 had reduced pain. There were no serious complications. We think that GKS is an effective treatment option for patients with medical refractory idiopathic TN.

Fluoxetine improves the quality of life in patients with poststroke emotional disturbances

BACKGROUND

Fluoxetine may improve the poststroke emotional disturbances. The purpose of the present study was to evaluate the efficacy of fluoxetine on quality of life (QOL) over time in stroke patients with emotional disturbances.

METHODS

We studied 152 consecutive stroke patients (mean age, 58 years) who had either poststroke depression (PSD), emotional incontinence (PSEI) or anger proneness (PSAP) at an average of 14 months (range = 3-28) after the onset of stroke. The Korean version of SF-36 was used to assess the QOL. The presence of PSD, PSEI and PSAP was also determined with a standardized questionnaire. The subjects were given either 20 mg/day of fluoxetine (n = 76) or placebo (n = 76) for 3 months. Follow-up evaluations were done at 3, 6 and 12 months after the beginning of the treatment.

RESULTS

The score in the mental health domain was significantly higher in the fluoxetine group than in the placebo group at the 3-, 6- and 12-month follow-ups. The scores in the general health (p < 0.05) and social functioning (p < 0.05) domains were also significantly higher in the fluoxetine than in the placebo group at 12 months of follow up even if there was no definitive improvement in PSD, PSEI and PSAP at this time.

CONCLUSIONS

Fluoxetine is effective in improving QOL, particularly so in the mental health subdomain. Our results suggest that fluoxetine may be used to improve the QOL of stroke patients with emotional disturbances.

Acute renal failure due to acute tubular necrosis caused by direct invasion of Orientia tsutsugamushi

We describe a scrub typhus patient with acute renal failure for whom a diagnosis was made based on serology as well as immunohistochemical (IHC) staining and an electron microscopic examination (EM) of a renal biopsy specimen. For our case, we demonstrated by IHC staining and EM that renal failure was caused by acute tubular necrosis due to a direct invasion of Orientia tsutsugamushi.

Detection of intracranial atherosclerotic steno-occlusive disease with 3D time-of-flight magnetic resonance angiography with sensitivity encoding at 3T

BACKGROUND AND PURPOSE

The spatial resolution of 3D time-of-flight MR angiography (TOF-MRA) can be improved within a reasonable examination time by combining 3T and sensitivity encoding technique. We evaluated the diagnostic performance of high-resolution 3D TOF-MRA at 3T in patients with suspected atherosclerotic steno-occlusive disease of the intracranial arteries.

MATERIALS AND METHODS

We assessed 160 arteries in 39 patients: 68 distal internal carotid arteries, 68 middle cerebral arteries, and 24 vertebrobasilar arteries. The measured voxel size of 3D TOF-MRA was 0.28 x 0.56 x 1.2 mm(3). Steno-occlusive disease was assessed independently by 2 observers using conventional angiography as the reference standard.

RESULTS

According to observers 1 and 2, respectively, 3D TOF-MRA at 3T had a sensitivity of 78%/85% (21/27, 23/27), a specificity of 95%/95% (126/133, 127/133), a positive predictive value of 75%/79% (21/28, 23/29), and a negative predictive value of 95%/97% (126/132, 127/131), using a 50%-99% threshold of diameter stenosis. For detection of complete occlusion, according to observers 1 and 2, respectively, 3D TOF-MRA at 3T had a sensitivity of 100% (13/13), a specificity of 99% (145/147), a positive predictive value of 87% (13/15), and a negative predictive value of 100% (145/145). Interobserver agreement of 3D TOF-MRA was excellent (kappa = 0.81).

CONCLUSION

High-resolution 3D TOF-MRA with sensitivity encoding at 3T can be used as a reliable diagnostic tool for the detection of clinically significant steno-occlusive disease of major intracranial arteries.

Transcriptional control of the HERV-H LTR element of the GSDML gene in human tissues and cancer cells

Long terminal repeats (LTRs) of human endogenous retroviruses (HERVs) have been reported to serve as alternative promoters in functional genes. The GSDML (gasdermin-like protein) gene located on human chromosome 17q21 has been found to be an oncogenomic recombination hotspot. Here, we identified the LTR element of HERV-H with reverse orientation as an alternative promoter of the GSDML gene and analyzed its expression pattern in human tissues and cancer cells. A reporter gene assay of the promoter activity of the LTR on the GSDML gene in human cancer cell lines (HCT-116 and HeLa) and a kidney cell line (Cos7) of African green monkey indicated that the LTR promoter with reverse orientation had stronger promoter activity than forward one. The transcripts of this LTR-derived promoter were widely distributed in various human tissues and cancer cells, whereas the transcripts of the cellular promoter were found only in stomach tissues and some cancer cells (HCT116, MCF7, U937, C-33A, and PC3). These findings suggest that the LTR element on the GSDML gene was integrated into the hominoid lineage and acquired the role of transcriptional regulation of human tissues and cancer cells.

Early and late recurrence of ischemic lesion on MRI: Evidence for a prolonged stroke-prone state?

BACKGROUND

Based on previous observations of a high rate of ischemic lesion recurrence on diffusion-weighted imaging (DWI) within 1 week after an acute ischemic stroke, the authors hypothesized that silent new ischemic lesions are common between 1 week and 90 days after index stroke and that early lesion recurrence may be associated with late lesion recurrence.

METHODS

The authors studied 80 acute ischemic stroke patients who had initial MRI performed within 48 hours, and follow-up scans at 5 days and at 30 or 90 days after onset. Early lesion recurrences were defined as new ischemic lesions on 5-day DWI, and late lesion recurrences were defined as those on 30- or 90-day DWI or fluid attenuation inversion recovery image. Early lesion recurrence occurring outside the initial perfusion deficit was termed distant lesion recurrence.

RESULTS

Late lesion recurrence occurred in 26%, more frequently observed on 30-day MRI than 90-day MRI (p = 0.016). Early lesion recurrence (OR 4.0; 95% CI 1.3 to 11.7) and distant early lesion recurrence (OR 6.9; 95% CI 1.5 to 32.2) were independently associated with late lesion recurrence by multiple logistic regression analyses.

CONCLUSIONS

There may be a continued risk for recurrent ischemic lesions in the weeks following the clinically symptomatic stroke. Future studies are needed to investigate whether MRI-defined ischemic lesion recurrences predict subsequent clinical recurrence and thus may be a potential surrogate endpoint in stroke secondary prevention trials.

Diffusion-weighted magnetic resonance imaging in Wernicke's encephalopathy

OBJECTIVE

To report diffusion-weighted imaging (DWI) findings and postulate the pathogenic mechanism of Wernicke's encephalopathy (WE).

PATIENT

A 47-year-old-woman presented with altered consciousness, ophthalmoplegia, and ataxia. DWI revealed the abnormal signal changes in periaqueductal gray matter, mamillary bodies and bilateral medial thalami. Apparent diffusion coefficient (ADC) map revealed the high signal intensity lesions in bilateral medial thalami, suggestive of vasogenic edema. The abnormal signal intensity lesions disappeared on follow-up imaging with clinical improvement.

CONCLUSIONS

Vasogenic edema plays an important role in the pathogenesis of WE and can be reversed by proper management. DWI findings in the early stage of WE may provide useful information about the prognosis.

Diffusion-weighted MR findings of central pontine and extrapontine myelinolysis

Diffusion-weighted MR (DWI) can detect changes in water diffusion associated with cellular dysfunction, which enables the differentiation of cytotoxic edema from vasogenic edema. In this study on DWI findings in central pontine (CPM) and extrapontine myelinolysis (EPM), DWI showed high signal intensities in the bilateral pons, midbrain, and genu of the corpus callosum. The corresponding apparent diffusion coefficient values were rather low. This suggests that cytotoxic edema does in fact exist in CPM and EPM and that DWI can be useful in the rapid diagnosis and prediction of the various types of edema occurring in active demyelinating diseases.

Inhibition of IgE-mediated mast cell activation by the paired Ig-like receptor PIR-B

The potential of the paired Ig-like receptors of activating (PIR-A) and inhibitory (PIR-B) types for modifying an IgE antibody-mediated allergic response was evaluated in mouse bone marrow-derived mast cells. Although mast cells produced both PIR-A and PIR-B, PIR-B was found to be preferentially expressed on the cell surface, where it was constitutively tyrosine phosphorylated and associated with intracellular SHP-1 protein tyrosine phosphatase. PIR-B coligation with the IgE receptor (FcepsilonRI) inhibited IgE-mediated mast cell activation and release of serotonin. Surprisingly, the inhibitory activity of PIR-B was unimpaired in SHP-1-deficient mast cells. A third functional tyrosine-based inhibitory motif, one that fails to bind the SHP-1, SHP-2, and SHIP phosphatases, was identified in parallel studies of FcepsilonRI-bearing rat basophilic leukemia (RBL) cells transfected with constructs having mutations in the PIR-B cytoplasmic region. These results define the preferential expression of the PIR-B molecules on mast cells and an inhibitory potential that can be mediated via a SHP-1-independent pathway.

Diffusion-weighted magnetic resonance in cerebral venous thrombosis

BACKGROUND

Cerebral venous thrombosis (CVT) is a cause of stroke with obscure pathophysiologic properties that differ from arterial stroke. Its main mechanisms of pathophysiology are the breakdown of the blood-brain barrier and the coexistence of cytotoxic and vasogenic edema. However, conventional magnetic resonance imaging (MRI) cannot differentiate between vasogenic and cytotoxic edema.

OBJECTIVES

To describe the diffusion-weighted imaging (DWI) findings and characterize the clinical applications of DWI in CVT.

SETTING

A tertiary referral center, neurology department.

DESIGN AND METHODS

From November 1998 to March 2001, 14 patients (5 men, 9 women; mean age, 43 +/- 10 years) with CVT underwent DWI, conventional MRI, MR venography, or conventional cerebral angiography. Abnormal findings on DWI and conventional MRI indicated the necessity of MR venography and conventional angiography to confirm the diagnosis of CVT. Apparent diffusion coefficient (ADC) values were measured in all of the abnormal lesions with visual inspection of DWI and T2-weighted echo planar imaging.

RESULTS

Findings on DWI were grouped according to 3 patterns: (1) Heterogeneous signal intensity (SI) (10 patients) showed mixed bright high SI and low SI and the corresponding ADC values were inversely correlated to the DWI SI. The areas of prominent low SI on DWI were reversed with adequate treatment on follow-up MRI in 1 patient. (2) Multifocal high SI (3 patients) was similar to that observed in acute arterial stroke. The corresponding ADC values were decreased and DWI was performed in the acute stages. (3) Intravascular clot with high SI was found with (1 patient, also in heterogeneous SI group) or without (1 patient) parenchymal lesions. In 1 patient, DWI demonstrated T2-negative and fluid attenuated inversion recovery-negative lesions without correlative symptoms.

CONCLUSIONS

These data suggest that DWI with ADC maps can be used to discriminate between types of edema for tissue viability and to provide information about stages and diagnostic clues in CVT.

Diffusion-weighted magnetic resonance imaging in nonconvulsive status epilepticus

BACKGROUND

In human and experimental models, diffusion-weighted magnetic resonance imaging (DWI) findings in status epilepticus (SE) have been reported to show that apparent diffusion coefficients are reduced during the initial phase and normalized or increased in the later phase of prolonged SE. This effect is caused by cytotoxic edema induced by excitotoxicity. In humans, only focal DWI abnormalities have been reported in partial SE.

OBJECTIVES

To report and discuss the DWI findings suggesting diffuse neuronal injury in a patient with nonconvulsive SE.

DESIGN AND METHODS

A 56-year-old man was admitted because of changing levels of consciousness over 3 days. On admission he was comatose. He had nystagmoid eye movement, forced eye blinking, and oroalimentary automatism. The results of a search for possible infectious and metabolic etiologies were negative, and electroencephalographic findings showed continuous, semirhythmic, bifrontal sharp waves of 2 Hz. Phenytoin and midazolam hydrochloride were infused to alleviate the seizure activities. He underwent DWI initially (3 days after the onset of seizure) and at the 5-month follow-up.

SETTING

The neurology department of a tertiary referral center.

RESULTS

During SE, DWI findings showed marked, diffuse gyriform cortical hyperintensity throughout the brain. The apparent diffusion coefficient decreased in the corresponding areas, especially in the occipital lobes. Findings from T2-weighted magnetic resonance imaging showed the intense cortical hyperintensity with gyral swelling and no involvement of brainstem, basal ganglia, thalamus, and white matter. The follow-up DWI findings showed marked atrophy and hypointensity in the corresponding regions. The apparent diffusion coefficient increased in the corresponding regions.

CONCLUSIONS

Diffusion-weighted imaging in our patient indicated that the magnetic resonance imaging abnormalities of the affected cortex were due to cytotoxic edema caused by neuronal excitotoxicity during prolonged SE. Diffusion-weighted imaging can be used in the localization of seizure focus for predicting the prognosis of the affected tissue and for researching the basic pathophysiology of SE.

The difference in perceptions of educational need between epilepsy patients and medical personnel

PURPOSE

This study was undertaken to determine what patients with epilepsy need to know about their condition, and to discern what differences exist between patients' perceptions of this need and the medical profession's perception of what patients should know.

METHODS

Seventy-five consecutive patients with epilepsy and 56 medical personnel (residents and nurses) who were working in either Neurology or Neurosurgery Units were studied using a structured questionnaire consisting of 3 subsets with a total of 27 questions.

RESULTS

Using a Likert scale, epilepsy patients gave high priority to their need for more information about "how epilepsy is diagnosed," "the structure of the brain" (p < 0.05, p < 0.01, respectively), and "the diet that might prevent the attack" (p < 0.05) than did medical personnel. Our study also revealed that men were more concerned with questions regarding smoking and drinking than were women (p < 0.05, respectively), whereas married patients gave higher scores in the category of employment (p < 0.01) and contraception/pregnancy (p < 0.05) than did unmarried patients. The patients with one or more seizures per month rated higher scores on questions concerning the first aid at the time of attack and dosage of antiepileptic drugs (AEDs; p < 0.05, respectively) than did the patients with fewer than one seizure per month. The patients taking poly-AED treatment gave higher scores on six items related to AED therapy than did those receiving monotherapy. No significant differences were found with regard to the length of time patients had the condition, nor to educational level or current employment status.

CONCLUSIONS

An educational program for epilepsy patients should be developed on the basis of understanding that there are differences in perspectives among patients with different sociocultural contexts as well as between patients and medical personnel.

Cerebral venous thrombosis associated with tentorial subdural hematoma during oxymetholone therapy

Androgen was reported to cause cerebral venous thrombosis (CVT) during replacement therapy for aplastic anemia. Oxymetholone, a synthetic androgen analogue, has been widely used in the treatment of aplastic anemia. A 40-year-old woman with aplastic anemia visited our hospital because of severe headache, nausea, vomiting, blurred vision and diplopia for a period of 1 month. She had taken oxymetholone for 2 years. Neurological examination revealed bilateral papilledema and bilateral sixth nerve palsies. Brain magnetic resonance imaging (MRI), performed at the time of admission, demonstrated left-sided tentorial SDH, and focal cerebral thrombosis of the left superficial sylvian vein and sigmoid sinus. MR venography revealed multiple irregularities in the superior sagittal sinus and left transverse sinus. CVT with tentorial subdural hematoma (SDH) caused by oxymetholone was strongly suggested. Oxymetholone was immediately discontinued, and her symptoms and signs disappeared. Because of the thrombocytopenia, anticoagulation was not started. She was discharged and visited the outpatient clinic without neurological symptoms for 6 months. This report supports the cautions given about the risk of CVT with oxymetholone supplementation in aplastic anemia. To the best of our knowledge, this is the first report of CVT associated with tentorial SDH that was probably caused by oxymetholone.

Intracranial cerebral artery disease as a risk factor for central nervous system complications of coronary artery bypass graft surgery

BACKGROUND AND PURPOSE

Although extracranial carotid artery disease (ECAD) is accepted as a risk factor for central nervous system (CNS) complications after coronary artery bypass graft (CABG) surgery, it remains to be clarified whether intracranial cerebral artery disease (ICAD) may also increase the risk. We conducted a prospective study to elucidate the relation between ICAD and CNS complications after CABG surgery.

METHODS

We prospectively studied 201 patients undergoing nonemergency isolated CABG surgery during a 39-month period (from March 1995 to June 1998). Each patient was evaluated before surgery with neurological examination, transcranial Doppler, and carotid duplex ultrasonography. Magnetic resonance angiography was used to determine the presence and severity of ECAD and ICAD in patients with abnormal findings on clinical examination, carotid duplex ultrasonography, or transcranial Doppler. Patients were followed after surgery and evaluated for the development of CNS complications. Association between CNS complications and their potential predictors was analyzed.

RESULTS

One hundred nine patients (54.2%) were found to have ECAD and/or ICAD. ECAD alone was found in 48 patients (23.9%), ICAD alone in 33 (16.4%), and both ECAD and ICAD in 28 (13.9%). Fifty-one patients (25.4%) had single or multiple CNS complications: 23 (11.4%) had delirium; 18 (9.0%) had hypoxic-metabolic encephalopathy; 7 (3.5%) had stroke; and 7 (3. 5%) had seizure. In multivariate analysis, ICAD was found to have an independent association with the development of CNS complications (prevalence OR, 2.28; 95% CI, 1.04 to 5.01) after controlling for covariates including age, occurrence of intraoperative events, and reoperation. The joint effect of ECAD and ICAD was also statistically significant and stronger than ICAD alone (prevalence OR, 3.87; 95% CI, 1.80 to 6.52).

CONCLUSIONS

Our results suggest that ICAD may be an independent risk factor for CNS complications after CABG surgery. These results support pre-CABG evaluation of the intracranial arteries for the risk assessment of CABG surgery, at least in black and Asian patients, in whom there may be a higher prevalence of intracranial arterial stenosis.

Neuroprotective effect of low dose riluzole in gerbil model of transient global ischemia

Riluzole is a neuroprotective agent the efficacy of which was proven in amyotrophic lateral sclerosis in human and in animal models of cerebral ischemia. However, the dosage used in animal experiments was much higher than that in human. We investigated the efficacy of low dose riluzole, which was similar to the dose used in human trials, in animal model of global ischemia. Global ischemia was induced in male Mongolian gerbils for 5min under monitoring of rectal temperature. Riluzole (0.8 mg/kg) were injected intraperitoneally 30min before ischemia. Seven days after ischemia, animals were decapitated and surviving nerve cells in hippocampal CA1 area were quantified. The number of surviving cells was compared between in riluzole-treated and control groups and the former showed statistically significant better survivals than the latter (P<0.001).

Diffusion-weighted imaging in Wallerian degeneration

We report two patients displaying hyperintensities on diffusion-weighted imaging (DWI) in the area of Wallerian degeneration (WD) at 12 days after stroke. High signal intensities were more conspicuous on DWI than on T2-weighted images. Both patients showed decreased diffusion anisotropy resulting in elevated apparent diffusion coefficient in the area of WD. These patients illustrate that DWI may be useful in the detection of the early stage of WD.

Acute bilateral cerebellar infarcts in the territory of posterior inferior cerebellar artery

The authors report 12 patients with acute bilateral cerebellar infarcts in posterior inferior cerebellar artery (PICA) territory. They found three topographic patterns: A) bilateral medial PICA in six patients; B) unilateral whole + contralateral medial PICA in four; and C) bilateral small multiple in two. Nine patients in Groups A and B had unilateral PICA or vertebral artery disease, and both patients in Group C had bilateral vertebral artery disease. These findings support that unilateral supply to both medial PICA territories may be the most relevant pathogenesis of this syndrome.

Trochlear nerve palsy in Sjögren's syndrome

Sjögren's syndrome (SS) is a systemic lymphoproliferative, autoimmune disease, which is characterized by dryness of the eyes, mouth, and other mucous membranes. The nervous system may be affected in up to 20% of the cases of primary or secondary SS. We present a case of a 54-year-old woman with trochlear nerve palsy complicating Sjögren's syndrome secondary to rheumatoid arthritis. We suggest that all patients with multiple cranial neuropathies, especially when associated with rheumatoid arthritis, should be carefully examined for the possible presence of secondary SS.

Neuronal metabolic changes in the cortical region after subcortical infarction: a proton MR spectroscopy study

OBJECTIVES

To investigate whether proton magnetic resonance spectroscopy ((1)H MRS) can detect neuronal metabolic changes in the cortical region in patients with cortical dysfunction after subcortical infarction.

METHODS

Fifteen patients with subcortical large (diameter>/=20 mm) infarcts were studied; nine patients with cortical dysfunction (group A), and six without (group B). Seven patients with lacunar infarction served as controls. Infarct volume was measured on T2 weighted images with an image analyser. (1)H MRS data were obtained in three regions; high signal intensity area on T2 weighted image, overlying cortex with a normal T2 MRI appearance, and contralateral homologous cortical region.

RESULTS

Infarct volume was not different between groups A and B. N-acetylaspartate (NAA)/creatine+phosphocreatine (Cr) ratios in the cortical region overlying subcortical infarcts in group A were significantly lower than those in group B and the control group (p=0.002). The NAA/Cr ratios in the overlying cortex were significantly lower than those in the contralateral normal cortex in group A on the initial (p=0. 015) and follow up (p=0.028) (1)H MRS, but these differences were not found in group B and the control group.

CONCLUSIONS

The results support the idea that the cerebral cortex is a responsible location for cortical dysfunction after subcortical infarctions. (1)H MRS can be used as a sensitive method for the detection of a neuronal metabolic damage, which is not demonstrated by conventional MRI.

Significance of acute multiple brain infarction on diffusion-weighted imaging

BACKGROUND AND PURPOSE

Diffusion-weighted imaging (DWI) is superior to conventional MRI in identification of small new ischemic lesions and discrimination of recent infarcts from old ones. Thus, this technique is useful in the detection of acute multiple brain infarcts (AMBI). We sought to determine the frequency and the topographical and etiologic patterns of AMBI detected on DWI.

METHODS

We studied 329 consecutive ischemic stroke patients who underwent DWI and MRI/MR angiography within 4 days of stroke onset. AMBI was defined as noncontiguous high signal intensities on DWI in >1 vascular territory. Stroke mechanism was determined according to the criteria of the Trial of Org 10172 in Acute Stroke Treatment (TOAST).

RESULTS

We detected AMBI in 95 patients (28.9%). AMBI in anterior circulation was found in 62 cases: in 1 hemisphere in 42 (group A) and in bilateral hemispheres in 20 (group B). Twenty-two patients had AMBI in the posterior circulation (group C) and 11 in both anterior and posterior circulations (group D). The most frequent cause of stroke was large-artery atherosclerosis in groups A (33/42), B (9/20), and C (15/22) (P=0.02) and cardioembolism in group D (6/11) (P=0.02). Elevated fibrinogen or hematocrit was significantly associated with group B (P=0.01). In 9 patients in groups B and D, anatomic variations of anterior or posterior cerebral arteries or patent posterior communicating artery contributed to AMBI.

CONCLUSIONS

Different topographical patterns of AMBI are associated with different vascular pathologies and stroke mechanisms. Hemorheologic abnormality or vascular anatomic variations may be contributing factors in the pathogenesis of AMBI in bilateral cerebral hemispheres or in both anterior and posterior circulations.

Interpretation of Wada memory test for lateralization of seizure focus by use of (99m)technetium-HMPAO SPECT

PURPOSE

Although the intracarotid amobarbital procedure (IAP) or Wada test is useful in lateralizing seizure focus in patients with temporal lobe epilepsy (TLE), the results of the IAP memory test are frequently nonlateralizing. An insufficient suppression of the medial temporal region contralateral to the seizure focus may contribute to the failure of lateralization. We tried to correlate IAP memory results with the functional changes in the contralateral medial temporal region as measured by single photon emission computed tomography (SPECT) during IAP.

METHODS

We performed a (99m)technetium-(Tc) hexamethylene-propylene-amine-oxime (HMPAO) brain SPECT in 19 medial TLE patients during a contralateral IAP (sodium amobarbital injected contralateral to the seizure focus). Regional cerebral blood flow (rCBF) was measured in the contralateral medial temporal region. The amount of decrease in the rCBF was calculated by subtracting the previous measurement from the one obtained with the interictal SPECT.

RESULTS

Ten (53%) patients passed and nine (47%) failed the contralateral IAP. The mean percentage decrease in rCBF was 5.3+/-5.3%. There was a significant negative correlation between a decrease in the rCBF and the IAP memory-retention score by Spearman correlation (p = -0.53: p<0.021). Patients with smaller decreases in rCBF (<5%) more frequently passed the contralateral IAP memory test than did those with larger decreases (80 vs. 22%; p<0.023).

CONCLUSIONS

We suggest that an insufficient suppression of the contralateral medial temporal function is partly responsible for nonlateralizing IAP memory tests. An IAP-SPECT may be useful in interpreting IAP memory tests for the lateralization of seizure focus in TLE patients.

Changes of 5-hydroxytryptamine release by different glucose concentration from hippocampal slices exposed to hypoxia

We have previously reported that the spontaneous release of [3H]5-hydroxytryptamine(5-HT) was markedly decreased by hypoxic insult in rat hippocampal slices. In the present study, the effect of glucose on 5-HT release was examined. Fractional release of [3H]5-HT was measured from an incubation medium exchanged every 10 min for 140 min and after stabilization of [3H]5-HT release, 10 or 20 min period of hypoxia was induced by exchanging the media which have been previously saturated by 95% N2/5% CO2 gas. In the media containing 1, 2, 5, 10 or 20 mM glucose, [3H]5-HT release was stabilized after 40 min of incubation. Exposure to hypoxia decreased [3H]5-HT release up to 60% of the control level in a glucose concentration-dependent manner and recovered gradually after hypoxic periods. However, in the media containing no glucose, the spontaneous release of [3H] 5-HT increased continuously during incubation. Moreover, when hippocampal slices were exposed to hypoxia, the [3H]5-HT release increased up to 150% of the control level and recovered gradually to the control level after hypoxic periods. These results demonstrate that hypoxia inhibits or enhances 5-HT release in the presence or absence of extracellular glucose respectively and suggest that the availability of extracellular glucose is a key factor to determine the direction of 5-HT release under hypoxic condition.

Characterization of T and B cells isolated from mucosa-associated tissues of the rhesus macaque

This study has assessed T cell subsets according to the expression of CD4 and CD8 and the isotype of surface Ig+ (sIg+) B cells and plasma cells in mononuclear cells (MC) isolated from mucosa-associated tissues of rhesus macaques in comparison to lymphoid cells from systemic tissues, i.e., spleen and peripheral lymph nodes (PLN). Using enzymatic and/or mechanical dissociation methods, mononuclear cells were isolated from lamina propria (LP) of the small (jejunum and ileum) and large (cecum) intestines, parotid glands (PG), and mesenteric lymph nodes (MLN). Approximately equal numbers of CD4+ and CD8+ T cells occurred in mucosa-associated tissues (CD4:CD8 ratios of 0.9-1.2), while slightly higher numbers of CD8+ T cells were seen in spleen and PLN (CD4:CD8 ratios of 0.6-0.9). When the isotypes of sIg+ B cells were assessed in MC isolated from mucosa-associated tissues, the highest frequency of sIgA+ B cells was seen in MLN, which may represent B cells which had recently migrated from IgA inductive sites. However, IgA effector tissues, such as intestinal LP and PG, contained frequencies of sIgA+ B cells lower than those of the MLN. When Ig-producing cells were examined, 50-90% of Ig-secreting cells were of the IgA class. This suggests that sIgA+ B cells differentiate into IgA plasma cells at higher rates in the mucosal effector tissues. Plasma cells of IgM isotype were also found in significant numbers in the LP of the intestine and PG, while IgG plasma cells were most prevalent in spleen and PLN. Taken together, mucosa-associated tissues of rhesus macaques are characterized by higher numbers of CD4+ T cells and Ig-secreting plasma cells of IgA and IgM isotypes than those of systemic lymphoid tissues.

In vivo performance evaluation of a transcutaneous energy and information transmission system for the total artificial heart

As part of an electromechanical total artificial heart (TAH) program, an integrated transcutaneous energy and information transmission (TEIT) system has been developed. In vivo performance of the developed system was evaluated through a simplified animal model without implant of a TAH. The design features include the small size of the implanted part, and dual coil structure of the external part. In the transcutaneous energy transmission (TET) system based on magnetic induction, the external primary and implanted secondary coils have the shape of a truncated cone, 7.0 and 3.8 cm in diameter, and 23 and 12 turns of Litz wire, respectively. The external coil is driven by a 350 to 410 kHz tuned class E amplifier that has a minimum switching loss of power transistor. In vitro test results using 1 cm thick dog's skin showed a flat total efficiency (DC to DC) of 75% for 20 to 30 W of delivered mean power. In order to achieve bidirectional communication between implanted and external components, a small circuit board containing four light emitting diodes and a photodiode was incorporated in each TET coil facing each other across the skin. Unmodulated optical pulse transmitted digital data (9600 baud, RS-232 protocol) in error free condition through an up to 15 mm thick dog's skin patch accommodated 18 degrees of misalignment. Three subacute in vivo studies were conducted in dogs to evaluate performance of the developed system. The secondary set was implanted in the mild flank region of the dog, and the output was percutaneously connected to the control system to drive the external TAH on the mock circulatory system.(ABSTRACT TRUNCATED AT 250 WORDS)

A system for the study of jaw movements

This paper describes a system to record incisal and condylar movements. It consists of two Charge Coupled Device (CCD) cameras that detect the position of markers fixed to the face, real-time hardware to recognize the markers and software for three-dimensional reconstruction of condylar and mandibular movements. The subject sat upright in front of the cameras and was asked to perform jaw movements. The position of the markers was recorded and the coordinates were fed into the computer and converted to three-dimensional kinematic data by a mathematical algorithm implemented on an AT IBM personal computer. Dedicated software calculated the head movements and the mandibular movements separately and performed a three-dimensional mathematical reconstruction of the movements of the condylar points and the interincisive point, using the geometrical rules of a rigid body. This pilot study describes the pattern from opening, closing, protrusive, and lateral movements as obtained from healthy subjects with good dentition.