Search PubMed⌕ Search

Biomedical subjects

S Sood

Publications and source records attributed to S Sood.

At least 19 recordsLinked to original sources
PubMed2001

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.

Animals↗
PubMed2001

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.

Cells, Cultured↗
PubMed2001

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.

Adult↗
PubMed2001

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.

Aged↗
PubMed2001

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.

Aged↗
PubMed2001

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.

Adult↗
PubMed2001

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.

Administration, Oral↗
PubMed2001

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.

Animals↗
PubMed2001

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.

Adolescent↗
PubMed2000

Hypoglossal-facial nerve anastomosis: assessment of clinical results and patient benefit for facial nerve palsy following acoustic neuroma excision.

Despite advances in neuro-otological techniques permanent complete facial palsy may still occur in up to 10% of patients undergoing removal of cerebellopontine angle tumours. Hypoglossal-facial nerve anastomosis is the procedure of choice in our unit for facial reanimation in such patients and below we report the results of hypoglossal-facial nerve anastomosis performed on 29 patients. Assessment of patient benefit from hypoglossal-facial nerve anastomosis was obtained using a questionnaire based on the Glasgow Benefit Inventory. The results showed all patients to have an improvement in their House Brackmann grade following hypoglossal-facial anastomosis with 65% achieving grade III or better. Of the 20 patients who completed the questionnaire, 18 showed a positive benefit (median score 59.5, range 40-77). There was a significant correlation (P < 0.045) between the Glasgow benefit inventory score and House Brackmann grade. Outcome was not affected by the time interval between the acoustic neuroma surgery and performing the hypoglossal-facial nerve anastomosis, sex or length of follow-up. However the Glasgow benefit score was significantly influenced by age (P = 0.023) with younger patients showing more benefit independent of improvement in facial nerve function.

Adolescent↗
PubMed2000

Head and neck basal cell carcinoma: treatment using a 2-mm clinical excision margin.

Treatment of basal cell carcinoma (BCC) should completely remove the tumour whilst preserving the maximum amount of normal surrounding skin. Therefore, treatment is a compromise between safe excision margins and obtaining a satisfactory cosmetic result. We report the results of a prospective study of 63 patients who underwent excision of well-demarcated BCCs in the head and neck region. The surgical excision margin used was 2 mm. Histological assessment confirmed complete excision in 95% and there was no evidence of recurrence of the BCC over a 24-month follow-up period in all patients. We propose that a clinical excision margin of 2 mm is adequate for treatment of simple, well demarcated BCCs arising in the head and neck.

Adult↗
PubMed2000

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.

Adult↗
PubMed2000

Evaluation of shunt malfunction using shunt site reservoir.

OBJECTIVE: To determine the usefulness of a separate reservoir placed at the site of the shunt in evaluation of shunt malfunction. METHODS AND MATERIALS: A ventricular catheter was placed alongside the proximal catheter of the shunt and connected to a subgaleal reservoir in 17 patients, in 9 a double-lumen catheter with integrated reservoir and in 13 patients a dual catheter with a double-port reservoir was used. At presentation of suspected shunt malfunction, a standard shunt function evaluation using shunt tap, CT scan or shunt injection was performed, and subsequently, the pressure from the tap of the reservoir was obtained. RESULTS: Thirty-three patients presented with symptoms of malfunction at an interval of 2.3 +/- 3 months (range 2-429 days). The pretest probability of shunt malfunction in this population was 73%. Posttest probability of shunt malfunction was 82.5% with standard evaluation and improved to 100% by the separate reservoir tap pressure measurement. In 4 patients in whom the shunt tap was dry, shunt infection was diagnosed prior to revision using CSF obtained at the reservoir tap. In 5 patients with proximal malfunction and bradycardia, the reservoir tap allowed early ventricular decompression. CONCLUSION: This study shows that a reservoir placed at the site of the shunt remains patient even when the shunt malfunctions, suggesting that flow rather than catheter position is important in proximal malfunction. It is superior to shunt tap for detection of shunt malfunction and infection, and it allows early ventricular decompression in a sick patient awaiting surgery for shunt revision.

Adolescent↗
PubMed2000

Postural changes in intracranial pressure in chronically shunted patients.

A subset of hydrocephalic patients with indwelling shunts become symptomatic when they are upright and active. Intracranial pressure (ICP) measurements in these patients have shown a significant drop in pressure when the patient is upright with return to normal levels when the patient is supine. In 20 chronically shunted hydrocephalic patients who previously had no siphon protection devices, ICP changes in supine and upright position were studied at the time when the patient had external ventriculostomy for treatment of shunt infection. Our hypothesis was that these patients might display rapid changes in ICP from fluid shifts occurring in non-CSF compartments. To minimize the effects of hysteresis, drift and zero-point error, measurements were made using a fluid manometer rather than a strain gauge pressure transducer. The pressure-volume index was estimated using the standard technique of bolus injection. Intracranial CSF volume was estimated on CT scans. The fluid shift was calculated using a mathematical model of the CSF compartment that incorporates negative pressure and volume components that permits simulation of siphoning. Sixteen patients had small, slit ventricles; 3 patients had moderate-sized ventricles and in 1 patient the ventricular size was normal. The average intracranial CSF volume estimated on CT scan was 12 cm(3). There was a mean drop in ICP in the upright position of 159 mm H(2)O. The mean PVI of 42 ml suggested a volume displacement out of proportion to the available intracranial CSF volume. Based on these findings, we conclude that even in the absence of drainage through the shunt, chronically shunted patients still display a fall in ICP when assuming the upright position. This raises the possibility of fluid shifts other than of CSF through nonshunt pathways. Possible mechanisms involving altered CSF-venous system interaction are discussed.

Adolescent↗
PubMed2000

Lavage administration of dilute recombinant surfactant in acute lung injury in piglets.

In an acute lung injury model, we previously observed reversal of pulmonary dysfunction with natural surfactant administered by lavage (dose = 18 mg/kg phospholipid). The present study questioned whether a lower dose of phospholipid would be effective if a recombinant preparation rather than natural surfactant were used. Acute lung injury was induced by repeated saline lung lavage in ventilated, sedated, and paralyzed piglets. Three concentrations of recombinant surfactant were studied (low phospholipid, 1 mg/mL; medium phospholipid, 4 mg/mL; high phospholipid, 13.5 mg/mL). Control piglets received no surfactant. Thirty-five milliliters per kilogram of surfactant was administered by gravity, followed by passive drainage of excess fluid. All treatment groups retained similar volumes (4.7+/-0.3 mL/ kg), corresponding to phospholipid doses of 4+/-0.4, 22+/-3, and 67+/-4 mg/kg in low, medium, and high-dose groups, respectively. Treatment groups showed significant improvement in Pao2 compared with controls. Other parameters different from controls were found in only the medium and high-dose groups. All surfactant-treated groups showed improvement over time in Pao2, Paco2, lung resistance mean airway pressure, functional residual capacity, and dynamic compliance. These data support the statement that whereas there is a dose response to exogenous surfactant, the effective dose of recombinant surfactant in acute lung injury may be as low as 4 mg/kg phospholipid when administered by lavage.

Animals↗
PubMed2000

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.

Aged↗
PubMed2000

Reply

Explore the source record for details and available documents.

Journal Article↗