Alpha-methyl-L-tryptophan PET detects epileptogenic cortex in children with intractable epilepsy

BACKGROUND

In children with tuberous sclerosis, the PET tracer alpha[11C]methyl-L-tryptophan (AMT) has been shown to be selectively taken up by epileptogenic tubers, thus allowing differentiation from nonepileptogenic tubers in the interictal state.

OBJECTIVE

To determine whether cortical areas showing increased AMT uptake in children without tuberous sclerosis complex with intractable neocortical epilepsy indicate the epileptogenic zone, and to assess the relative contributions of AMT and 2-deoxy-2[18F]fluoro-D-glucose (FDG) PET abnormalities to the localization of epileptogenic cortical regions.

METHODS

Areas of increased AMT and decreased FDG uptake were marked objectively as regions with abnormal asymmetry using an in-house written software in 27 children who underwent comprehensive evaluation for resective epilepsy surgery. The marked PET abnormalities were compared to the locations of scalp and subdural EEG epileptiform abnormalities, as well as histology and surgical outcome.

RESULTS

Focal cortical increases of AMT uptake were found in 15 patients. The lobar sensitivity (39.0%) of AMT PET for seizure onset was lower, but its specificity (100%) was higher (p < 0.0001) than that of hypometabolism on FDG PET (sensitivity 73.2%, specificity 62.7%). AMT PET abnormalities were smaller than corresponding FDG PET hypometabolic regions (p = 0.002), and increased AMT uptake occurred in two patients with nonlocalizing FDG PET. Histologically verified cortical developmental malformations were associated with increased AMT uptake (p = 0.044). Subdural electrodes adjacent to the area of increased AMT uptake were most often involved in seizure onset.

CONCLUSIONS

Focal increase of cortical AMT uptake in children is less sensitive but more specific for the lobe of seizure onset than corresponding FDG PET hypometabolism, and it is often associated with epileptogenic cortical developmental malformations. AMT PET can assist placement of subdural electrodes even when MRI and FDG PET fail to provide adequate localizing information. Cortical areas adjacent to increased AMT uptake should be carefully addressed by intracranial EEG because these regions often show a high degree of epileptogenicity.

Mechanism of antinociceptive effect of nimodipine in experimental diabetic neuropathic pain

This study used streptozotocin-(STZ; 50 mg/kg, i.v.) diabetic rats and monitored the weekly thermal nociceptive thresholds for 8-week diabetes. Nimodipine (10 mg/kg i.p.) treatment initiated after 8 weeks of diabetes antagonized the hyperalgesic response in diabetic rats. However, insulin treatment showed a partial response in these animals. Thermal hyperalgesia showed reduced sensitivity to the antinociceptive effect of morphine (5 mg/kg, i.p.). Furthermore, a reduced sensitivity to the antinociceptive effect of baclofen (GABAB agonist; 4 mg/kg i.p.) was observed. Five days of treatment with MK-801 (N-methyl-D-aspartate [NMDA] receptor antagonist 0.5 mg/kg i.p.) completely reversed 8-week diabetes-induced thermal hyperalgesia. These data suggest that diabetes-induced hyperalgesia may be the consequence of increased excitatory tone within the spinal cord. An increased release of glutamate and activation of the NMDA receptor would maintain the hyperalgesic state. Reduced activity of both opioidergic and GABAB ergic inhibitory systems might accelerate the increased excitation, thus contributing to the ongoing pain in diabetic rats.

Effect of body posture on dynamic lung functions in young non-obese Indian subjects

Flow volume loop and its various indices can be used to diagnose UAO. Change in posture from sitting to horizontal position per se causes a decrease in effort dependent inspiratory and expiratory flow rates but no significant change in upper airway obstruction indices. Thus, measurement of FVL in supine posture may be used to detect UAO as it may be missed if spirometry is performed in sitting posture.

Modulatory effects of Salmonella LAP-LPS on murine macrophages

PURPOSE

To study the modulatory effects of Salmonella lipid associated protein - lipopolysaccharides (LAP-LPS) on murine macrophages as the intracellular survival within the host macrophages is an important feature for a number of gram-negative pathogens like S. typhi.

METHODS

Macrophage functions were studied in two groups of mice immunized with either LPS or LAP-LPS.

RESULTS

Comparison of protective efficacy of mice preimmunized with LPS based preparations, against challenge infectious doses, showed higher protection in LAP-LPS complex immunized mice group as compared to the mice group immunized with LPS alone. Aggregation of S. typhi cells was lesser with intestinal mucus extracted from LAP-LPS immunized mice as compared to LPS immunized challenged group. A significant increase in the number of macrophages in LAP-LPS immunized mice was also observed in comparison to control and LPS immunized mice groups. Nitric oxide (NO) and superoxide dismutase (SOD) production were also more in macrophages derived from LAP-LPS immunized mice group. Phagocytic uptake studies showed that there was enhanced uptake of bacteria in the LAP-LPS immunized animals in comparison to LPS immunized and controls. Similar trend was observed in intracellular killing of bacteria by the macrophages.

CONCLUSIONS

The results indicated the involvement of protein moiety in LAP on modulation of effects of LPS on macrophages.

Allergic otitis externa

Chronic otitis externa is a common condition, which is usually successfully treated by topical medications and aural toilet. In cases that persist despite conventional treatment, a diagnosis of allergic otitis externa should be considered. Sensitization to otic medications (secondary contact otitis) is not uncommon. Topical aminoglycosides are the most common sensitizers although many components of topical preparations can cause sensitization. Patients who may have developed allergic otitis externa should undergo patch testing. Otolaryngologists should consider using topical antibiotics with a low allergenic potential and avoiding neomycin when treating patients with otitis externa. Primary contact otitis may occur to metals used in earrings and also to hearing aid moulds. Treatment of both primary and secondary contact otitis consists of identifying the allergen, avoiding further contact and use of simple preparations avoiding common sensitizers.

Correlation between CT scan and automated perimetry in supratentorial tumors

An attempt was made to correlate various types of visual field defects on automated perimetry with the findings of computed tomography in 44 patients of supratentorial tumors. All the patients above the age of 10 years were subjected to complete neurological examination including investigations like plain X-rays and CT scan, however, MRI and angiography were performed wherever indicated. Ocular examination particularly pertaining to neuro-ophthalmological profile was carried out with special emphasis on automated perimetry on Humphrey field analyser. The results indicated that automated perimetry was capable of reliably detecting and quantitating the visual field defects and thus established the location of the tumor in 72% patients when compared to CT scan. Hence, any patient with neuro-ophthalmic features should be subjected to automated perimetry for early diagnosis and probable location of intracranial space occupying lesion affecting visual pathways.

Combination of pulsed-field gel electrophoresis (PFGE) and single-enzyme amplified fragment length polymorphism (SAFLP) for differentiation of multiresistant Salmonella enterica serotype typhimurium

OBJECTIVE

To assess the combined application of plasmid profile typing, pulsed-field gel electrophoresis (PFGE) and PCR-based single-enzyme amplified fragment length polymorphism (SAFLP) for the differentiation of 18 multiresistant (MR) and one drug-sensitive strain of Salmonella enterica serotype typhimurium from humans and food animals.

METHODS

Strains were phage typed and tested for resistance to a panel of antimicrobial agents. Strains were also tested for the ability to transfer resistance either directly or by mobilization to standard strains of Escherichia coli K12. Plasmid DNA was extracted from both drug-resistant donor strains and from drug-resistant exconjugants. Total genomic DNA was characterized by PFGE following digestion with the restriction endonuclease XbaI. The resultant patterns were categorized and analyzed by dendrogram analysis using the Dice coefficient and by data clustering using unweighted pair-group arithmetic averaging (UPGMA). Isolates were also characterized and categorized by SAFLP. The levels of discrimination achieved by each method were assessed individually and in combination.

RESULTS

Plasmid DNA was detected in all of the 18 MR isolates but, not in the drug-sensitive isolate. Using PFGE, 19 different profiles were identified, falling into eight major categories. However, by SAFLP, only eight profiles were observed. Subsequent investigations have demonstrated epidemiologic relationships within at least one of these SAFLP profile groupings.

CONCLUSIONS

These studies have demonstrated that PFGE and SAFLP can be used independently for the differentiation of MR S. Typhimurium from humans and food animals. However, when used in combination, SAFLP can provide a format for broad epidemiologic groupings. These groupings can be further subdivided by PFGE to provide detailed information on putative strain relationships at the genotypic level.

Left ventricular function in varicose veins

Left ventricular function (LVF) was evaluated noninvasively by recording systolic time intervals (STIs) in 25 patients suffering from varicose veins (VV) of lower limbs and compared with 25 age--sex matched controls. STI was measured from simultaneous recordings of electrocardiogram (ECG), carotid arterial pulse (CAP) and phonocardiogram (PCG). The left ventricular ejection time (LVET) was significantly shortened with marked increase in pre-ejection period (PEP) and increase in PEP/LVET ratio (P < 0.001) without any variation in electromechanical systoles (QS2) in VV patients compared to controls. These changes in STI suggest contractility of heart is adversely affected in VV patients.

Syphilitic panuveitis and asymptomatic neurosyphilis: a marker of HIV infection

Co-existing human immunodeficiency virus (HIV) infection can alter the course and presentation of syphilis. Severe ocular manifestations and accelerated natural course of syphilis along with neurosyphilis may be associated with HIV infection. A 30-year-old man is described in whom syphilitic panuveitis and asymptomatic neurosyphilis served as a marker for HIV infection.

Autonomic functions in Buerger's disease

One of the pathophysiological features in Buerger's disease, i.e. thromboangitis obliterans (TAO), is vasospastic phenomena. So autonomic reactivity was evaluated in 12 patients of Buerger's disease (1-6 years duration) and compared to age and sex matched controls (nonsmokers). Basal heart rate was significantly (P < 0.001) higher without any variation in blood pressure in TAO group compared to controls. Valsalva ratio (P < 0.01) and 30:15 ratio (P < 0.001) were increased without any effect on E:I ratio in TAO group versus controls. On head up tilt (HUT), there was significant (P < 0.001) fall in blood pressure in TAO group compared to controls. On cold pressure test (CPT), systolic blood pressure was reduced significantly (P < 0.01) in TAO group than that of controls, however, diastolic blood pressure showed no change in two groups. Responses indicate towards lower sympathetic reactivity in Buerger's patients.

Human vagus nerve electrophysiology: a guide to vagus nerve stimulation parameters

The authors studied human vagus nerve electrophysiology intraoperatively on 21 patients (age range: 4 to 31 years) during implantation of a vagus nerve stimulator for seizure control. The study was performed with direct electrical stimulation of the vagus nerve with various stimulation parameters resembling those employed by the Cyberonics NeuroCybernetic Prosthesis System (Houston, TX), which is used clinically for vagus nerve stimulation for treatment of seizures. Recordings were made directly from the rostral end of the vagus nerve. The response of the vagus nerve to various stimulus parameters in patients of different ages was studied. Based on the vagus nerve characteristics, age-related adjustments for stimulus parameters were recommended.

Ocular fireworks injuries. Clinical features and visual outcome

In a prospective analysis of ocular fireworks injuries over three consecutive years (1997 to 1999) during the Indian festival of Diwali, 42 patients presented with various types of fireworks-related ocular injuries. Twenty two (52%) patients had to be admitted for the management of their ocular injuries.

Pharyngeal pouch (Zenker's diverticulum)

Pharyngeal pouches occur most commonly in elderly patients (over 70 years) and typical symptoms include dysphagia, regurgitation, chronic cough, aspiration, and weight loss. The aetiology remains unknown but theories centre upon a structural or physiological abnormality of the cricopharyngeus. A diagnosis is easily established on barium studies. Treatment is surgical via an endoscopic or external cervical approach and should include a cricopharyngeal myotomy. Unfortunately pharyngeal pouch surgery has long been associated with significant morbidity, partly due to the surgery itself and also to the fact that the majority of patients are elderly and often have general medical problems. External approaches are associated with higher complication rates than endoscopic procedures. Recently, treatment by endoscopic stapling diverticulotomy has becoming increasingly popular as it has distinct advantages, although long term results are not yet available. The small risk of developing carcinoma within a pouch that is not excised remains a contentious issue and is an argument for long term follow up or treating the condition by external excision, particularly in younger patients.

Effectiveness of the ultrasonic harmonic scalpel for tonsillectomy

The Ultracision harmonic scalpel (UHS) cuts and coagulates tissue with high-frequency ultrasound. We describe the results of our use of the UHS to perform tonsillectomies in 59 patients. The mean operative blood loss was 7 ml (range: 0 to 75); 56% of patients experienced no measurable blood loss. The mean length of operating time was 8 minutes and 10 seconds (range: 3:45 to 20:25). Patients were assessed for 2 weeks for postoperative pain on the basis of a 10-point linear analog scale. The mean pain score on postoperative day 1 was 4.7; the score peaked at 6.0 on day 4 and fell to less than 3.0 by day 11. Patients returned to full function in an average of 10.9 days (range: 3 to 15). Three patients experienced secondary hemorrhage, one of whom required surgical intervention. We found the UHS to be a well-designed and easy-to-use instrument. Operating time was short, blood loss was minimal, and the degree of early postoperative pain was low. We believe that our findings are encouraging and that the UHS might well have a place in the surgical armamentarium for tonsillectomy.

Microdialysis perfusion of 5-HT into hypoglossal motor nucleus differentially modulates genioglossus activity across natural sleep-wake states in rats

1. Serotonin (5-hydroxytryptamine, 5-HT) excites hypoglossal (XII) motoneurons in reduced preparations, and it has been suggested that withdrawal of 5-HT may underlie reduced genioglossus (GG) muscle activity in sleep. However, systemic administration of 5-HT agents in humans has limited effects on GG activity. Whether 5-HT applied directly to the XII motor nucleus increases GG activity in an intact preparation either awake or asleep has not been tested. 2. The aim of this study was to develop a novel freely behaving animal model for in vivo microdialysis of the XII motor nucleus across sleep-wake states, and test the hypothesis that 5-HT application will increase GG activity. 3. Eighteen rats were implanted with electroencephalogram and neck muscle electrodes to record sleep-wake states, and GG and diaphragm electrodes for respiratory muscle recording. Microdialysis probes were implanted into the XII motor nucleus and perfused with artificial cerebrospinal fluid (ACSF) or 10 mM 5-HT. 4. Normal decreases in GG activity occurred from wakefulness to non-rapid eye movement (non-REM) and REM sleep with ACSF (P < 0.01). Compared to ACSF, 5-HT caused marked GG activation across all sleep-wake states (increases of 91-251 %, P < 0.015). Importantly, 5-HT increased sleeping GG activity to normal waking levels for as long as 5-HT was applied (3-5 h). Despite tonic stimulation by 5-HT, periods of phasic GG suppression and excitation occurred in REM sleep compared with non-REM. 5. The results show that sleep-wake states differentially modulate GG responses to 5-HT at the XII motor nucleus. This animal model using in vivo microdialysis of the caudal medulla will enable the determination of neural mechanisms underlying pharyngeal motor control in natural sleep.

Presence of Chlamydia pneumoniae in human symptomatic and asymptomatic carotid atherosclerotic plaque

BACKGROUND

Chlamydia pneumoniae has been identified in atherosclerotic plaques of patients with cerebrovascular and cardiovascular disease. However, the direct causative effect of C pneumoniae infection in the activation of atherosclerotic plaque to a prothrombotic state remains to be established. The aim of the present study is to examine the correlation between intraplaque presence of chlamydiae and symptomatic carotid disease in humans.

METHODS

Plaques from 37 symptomatic and 57 asymptomatic consenting patients undergoing carotid endarterectomy were snap-frozen, and the tissue was prepared for polymerase chain reaction analysis for Chlamydia pneumoniae per Institutional Review Board-approved protocol. Blood was drawn from each patient at the time of surgery for serological analysis.

RESULTS

The overall rate of plaques positive for C pneumoniae was 14.82%, with 5 of 37 (13.5%) plaques from symptomatic patients and 9 of 57 (15.8%) from asymptomatic patients, which revealed a definitive presence of the organism. No association existed between C pneumoniae presence and symptomatic disease (P:=1.0). Also, no association existed between presence of C pneumoniae and severity of stenosis. Finally, seropositivity for anti-chlamydial IgG, IgA, and IgM anti-chlamydial antibodies did not correlate with identification of C pneumoniae in the plaques. However, high-serum anti-chlamydial IgA levels (>/=1:128) were associated with occurrence of symptomatic disease (P=0.03; odds ratio, 2.86; 95% CI, 1.12 to 7.28).

CONCLUSIONS

Presence of C pneumoniae as a single factor does not appear to be sufficient to explain the occurrence of cerebrovascular symptoms. Low sensitivity of seropositivity for IgG, IgA, or IgM associated with PCR-identified C pneumoniae presence in the plaque makes it unlikely to be valuable as the single determining factor for actively infected plaque. Association of high-level anti-chlamydial IgA with symptomatic disease suggests that chronic or acute chlamydial infection anywhere in the body could play a role in atherosclerotic plaque activation and be used as a marker to target populations in future stroke prevention trials.

Effects of lisinopril on streptozotocin-induced diabetic neuropathy in rats

Streptozotocin (STZ)-induced diabetic neuropathy in rats was monitored by measuring the motor nerve conduction velocity (MNCV) and histopathology of the tibial nerve. Pretreatment with lisinopril (2 mg/kg p.o., 5 days prior to STZ and continued for 10 weeks) significantly (p < 0.01) prevented deterioration of MNCV as compared to STZ-diabetic animals. Nerve sections from the lisinopril pretreated group revealed less structural damage as compared to STZ-diabetic rats. However lisinopril had no effect on blood sugar, i.e., it did not alter the diabetic state. It is concluded that lisinopril prevents the development of experimental diabetic neuropathy in STZ-induced diabetic rats.

Increased interleukin 5 production in eosinophilic Sézary syndrome: regulation by interferon alfa and interleukin 12

BACKGROUND

Peripheral eosinophilia occurs in a small subpopulation of patients with cutaneous T-cell lymphoma (CTCL) and denotes a poor prognosis. Clinical studies have suggested that the Sézary cell is a T(H)2 type helper T cell that produces cytokines that enhance the differentiation and activation of eosinophils. Interferon alfa (IFN-alpha) and interleukin 12 are effective therapeutic agents for CTCL and other hematologic disorders.

OBJECTIVE

Our purpose was to determine the inhibitory activity of IFN-alpha and IL-12 on IL-5 production in vitro by peripheral blood mononuclear cells (PBMCs) obtained from patients with CTCL and eosinophilia.

METHODS

Suppression of IL-5 production by IFN-alpha and IL-12 was assessed by comparing IL-5 production by PBMCs from patients with Sézary syndrome and eosinophilia when cultured alone or in the presence of either IFN-alpha or IL-12.

RESULTS

A marked increase in IL-5 production by PBMCs from patients with Sézary syndrome and eosinophilia was observed. IL-5 production was markedly reduced when PBMCs were exposed to IFN-alpha or IL-12.

CONCLUSION

These results suggest that IFN-alpha and perhaps IL-12 may produce a therapeutic response in patients with CTCL and eosinophilia through direct suppression of IL-5 production by malignant Sézary cells.

In vivo and in vitro influence of selenium on DNA/RNA synthesis in spleen and lymphocytes in culture--possible mediation of changes in GSH/GSSG ratio

Effect of superanutritional levels of selenium (Se) as sodium selenite (0.5 and 1.5 ppm) given orally to Balb/c mice for one and two weeks was observed on the rate of DNA/RNA synthesis, levels of reduced as well as oxidized glutathione (GSH and GSSG) and glutathione peroxidase (GSH-Px)/glutathione-S-transferase (GSH-S-transferase) activities in spleen. Similar effect of three different concentrations of Se (10(-7), 10(-5) and 10(-3) M) in culture media was also observed on the rate of DNA/RNA synthesis in proliferating lymphocytes taken from mice spleen. The results of the present study indicated that with increasing concentration and duration of Se treatment in vivo and in vitro, a marked inhibition of the rate of DNA/RNA synthesis was observed. Levels of total glutathione and GSSG in spleen were elevated significantly only after two weeks in 1.5 ppm treatments. Glutathione peroxidase activities in spleen decreased (p < 0.05) in 1.5 ppm group at one week and in 0.5 ppm group at two week treatment. At higher Se treatment, the activity recovered towards control. However, GSH-S-transferase in spleen remained unchanged at all treatment intervals. The results indicated that changes in glutathione system by increasing Se concentration might account for inhibition of rate of DNA/RNA synthesis.

The effect of hypertonicity on nasal mucociliary clearance

The effect of the tonicity of saline nasal douching solutions on mucociliary clearance was studied in order to ascertain whether hypertonicity conferred any advantage. Thirty-eight normal subjects were included in a randomised double-blind crossover trial. Saline douching solutions of 0.9%, 3% and 5% tonicity were used and mucociliary clearance was measured by the saccharin clearance time (SCT). The resultant SCT after administration of 5% saline was significantly reduced compared to both 0.9% (P = 0.005) and 3% saline (P = 0.04). There was no difference between 0.9% and 3% saline administration. Thus hypertonic saline solutions improve mucociliary clearance, although this was only observed with solutions of 5% tonicity. The effect is probably brought about by changes in mucus rheology.

Endoscopic stapling of pharyngeal pouches in patients from the Yorkshire region

The treatment of pharyngeal pouches by endoscopic stapling diverticulotomy has gained popularity over the last few years. We assessed the results of this technique in 44 patients by means of a clinical questionnaire and by reviewing case records. Thirty-six (82 per cent) patients commenced oral intake within 18 hours of the procedure and 37 (84 per cent) patients were discharged within 48 hours. Five patients had complications that included throat discomfort, a loose incisor tooth, shoulder pain, pharyngeal perforation and one mortality due to mediastinitis. Of the 37 patients that completed the questionnaire, nine (24 per cent) had some residual symptoms although only two (five per cent) felt that there had been no improvement at all following the stapling procedure. Thirty-five (95 per cent) of the patients stated that they would undergo the procedure again. It appears that pharyngeal pouches can be successfully treated by endoscopic stapling, with patients commencing oral intake within a few hours of surgery and having a short hospital stay. However, as there can be serious complications, we recommend that the procedure be performed by an experienced surgeon.