PubMed Health⌕ Search

Biomedical subjects

S Mirza

Publications and source records attributed to S Mirza.

At least 19 recordsLinked to original sources

Ice cold carbonated water: a therapy for persistent hyperawareness of pharyngeal mucus and throat clearing.

Chronic throat clearing or a feeling of 'something' at the back of the oropharynx or nasopharynx is a common cause for referral to otorhinolaryngology services. While treatment of an underlying causative condition might be expected to improve these symptoms, in many cases a clear underlying cause is not found. Currently, there is no recognized treatment which is effective against these troublesome symptoms. This observational study investigated the effectiveness of a regime of sipping ice cold carbonated water to try to break the vicious cycle of throat clearing. Seventy-two patients with these symptoms who had previously been advised to use the regime were contacted with a postal questionnaire. Sixty-three per cent of patients documented an improvement in their symptom severity score. The most severely and most frequently affected patients had the greatest benefit. We conclude that the suggested regime can be effective in breaking the vicious cycle of persistent throat-clearing.

Adult↗

Analysis of purified gp96 preparations from rat and mouse livers using 2-D gel electrophoresis and tandem mass spectrometry.

The stress protein gp96 exhibits a number of immunological activities, the majority of studies into which have used gp96 purified from a variety of tissues. On the basis of 1-D gel electrophoresis, the purity of these preparations has been reported to range between 70% and 99%. This study analyzed gp96 preparations from rat and mouse livers using 2-D gel electrophoresis and liquid chromatography electrospray ionization tandem mass spectrometry (MS-MS). The procedure for purifying gp96 was reproducible, as similar protein profiles were observed in replicate gels of gp96 preparations. The purity of the preparations was typically around 70%, with minor co-purified proteins of varying molecular weights and mobilities being present. Dominant bands at 95-100 kDa in preparations from Wistar rats and C57BL/6 mice were identified as gp96 by ECL Western blotting. Multiple bands having similar, yet distinct molecular weights and differing pI mobility on ECL Western blots were confirmed as being gp96 in preparations from Wistar rats using MS-MS. The most striking feature of the 2-D gel analysis was the presence of additional dominant bands at 55 kDa in preparations from Wistar rats, and at 75-90 kDa in preparations from C57BL/6 mice. These were identified as gp96 by ECL Western blotting and, in the case of preparations from Wistar rats, by MS-MS. Although the lower molecular weight, gp96-related molecules might be partially degraded gp96, their reproducible presence, definition and characteristics suggest that they are alternative, species-specific isoforms of the molecule. A 55 kDa protein which exhibited a lower pI value than gp96 was present in all preparations and this was identified as calreticulin, another putative immunoregulatory molecule. This study confirms the reproducibility of the gp96 purification protocol and reveals the presence of multiple gp96 isoforms, some of which likely result from post-translational modifications such as differential glycosylation and phosphorylation.

Animals↗

Is Ki67 a marker for the transformation of laryngeal dysplasia to carcinoma?

CONCLUSION: Ki67 is not a reliable marker of malignant transformation in laryngeal dysplasia. OBJECTIVES: No reliable means of predicting which cases of laryngeal dysplasia will undergo malignant transformation currently exists. Our aim was to evaluate Ki67, a marker of cell proliferation, as a potential marker for the transformation of laryngeal dysplasia to squamous cell carcinoma. PATIENTS AND METHODS: Eighty consecutive cases of previously untreated patients with a histological diagnosis of laryngeal dysplasia from 1987 to 1993 were identified from the pathological archives. Standard immunohistochemical techniques were used to identify Ki67-positive cells and activity was scored on a scale of 0-4 using defined criteria. RESULTS: Of the 80 cases there were 24 females and 56 males with a mean age of 56 years (range 29-80 years). Twenty cases subsequently transformed to a squamous cell carcinoma. For each Ki67 score (0-4), the rate of malignant transformation was: 0, 1 of 6 patients (17%); 1, 7 of 33 patients (21%); 2, 5 of 22 patients (23%); 3, 4 of 13 patients (31%); and 4, 3 of 6 patients (50%). A higher Ki67 score seemed to correlate with a higher likelihood of malignant transformation but this did not reach statistical significance (p=0.17, Pearson chi(2) test). Considering a score of 3 or 4 as positive for predicting malignant transformation produced a test of relatively high specificity (80%) but poor sensitivity (35%).

Adult↗

Sinonasal cerebrospinal fluid leaks: management of 97 patients over 10 years.

INTRODUCTION: Although endoscopic closure is now the treatment of choice in the majority of patients with sinonasal cerebrospinal fluid (CSF) leaks, there is a recurrence rate of up to 10% in most series. OBJECTIVES: Our aim was to review our experience in the management of CSF leaks and in particular the cause of recurrent leaks. METHODS: We prospectively collected data on all cases referred as a suspected CSF leak to us, a tertiary referral center, over a 10 year period between 1994 and 2004. RESULTS: The 121 patients referred with an apparent CSF leak had a mean age of 51 (range 2-87) years. Fifty-three percent were male, and 47% were female. In 24 cases, investigations revealed that there was in fact no CSF leak, and in 17 posttraumatic cases, the leak ceased spontaneously. Twenty-nine patients had a spontaneous CSF leak. Of the 80 cases surgically repaired, 72 had an endoscopic approach, with a success rate of 90%, increasing to 97% after a second procedure and 99% by a third procedure. Eight patients with a posterior wall frontal sinus leak underwent an external frontal sinus procedure. There were 8 failures, and 6 occurred in the 13 patients with a spontaneous leak and evidence of raised intracranial pressure (ICP). CONCLUSIONS: In conclusion, our endoscopic repair rate for sinonasal CSF leaks are good and compare well with the standards in the literature. Raised ICP is the most common reason for recurrent CSF leak after repair. Patients with a spontaneous CSF leak and evidence of raised ICP had a 46% failure rate. When consenting such patients for surgery, they must be informed of the lower success rate and that they may need additional procedures, including shunting.

Adolescent↗

Otic barotrauma from air travel.

Otic barotrauma occurring during air travel involves traumatic inflammation of the middle ear, caused by a pressure difference between the air in the middle ear and the external atmosphere, developing after ascent or more usually descent. The pressure difference occurs because of failure of the eustachian tube to equilibrate middle ear and atmospheric pressures. It is a common problem, presenting with ear fullness, otalgia and deafness. Severe cases may result in tympanic membrane perforation and even round window membrane rupture. Of three randomized controlled trials, one showed that oral pseudoephedrine decongestants reduced otalgia in adults with recurrent ear pain during air travel, whilst another found that oral pseudoephedrine did not decrease in-flight ear pain in children. The third trial showed that oxymetazoline decongestant nasal spray, taken 30 minutes before descent, did not produce a statistically significant reduction in symptoms of barotrauma in adults with recurrent ear pain during air travel. We review the causes, prevention and treatment of this condition.

Adult↗

Penetrating keratoplasty in adults with congenital glaucomas.

PURPOSE: To report the problems and outcomes of penetrating keratoplasty (PKP) in patients with corneal oedema due to congenital glaucoma. METHOD: Case note review of nine such consecutive patients treated with PKP. A Kaplan - Meir survival curve was plotted for the series. RESULTS: Nine patients, ranging in age from 27 to 71 years at the time of their surgery were followed up for a mean of 28 months. All had undergone previous surgery for glaucoma. Preoperatively all patients had controlled intraocular pressures, and four were on ocular hypotensives. Two patients developed corneal graft failure at 15 and 41 months postoperative. Raised pressure was the cause in both. Final visual acuity improved in five patients, was the same in three, and deteriorated in only one. Complications included raised intraocular pressure, cataract, retinal detachment, and endophthalmitis secondary to an infected Molteno implant. CONCLUSION: Despite multiple impediments to good postoperative vision including previous surgery and pre-existing glaucomatous damage, a successful outcome was achieved by careful patient selection, and an awareness of, and meticulous attention to postoperative complications.

Adult↗

Regional audit: perioperative management of MRSA orthopaedic patients in the Oxford region.

AIM: Methicillin resistant staphylococcus aureus (MRSA) colonisation or infection is of particular importance in patients undergoing operations involving implantable materials, such as in orthopaedic surgery. An audit of the perioperative management of orthopaedic patients in the Oxford region was carried out to assess the level of clinician awareness and the uniformity of current guidelines between hospitals. METHODS: A postal questionnaire was designed for asking information on various aspects of perioperative management of MRSA patients and was sent to each hospital. RESULTS: Responses were obtained from nine of 10 hospitals in the region. The average response rate for each hospital was 75%, and the overall individual response rate was 67.5% (27/40). Seventy-eight per cent of respondents knew that there was a pre-admission screening policy. Fifteen per cent were unaware of any MRSA policy. Forty-four per cent indicated that teicoplanin was used for prophylaxis in implant surgery whilst 44% used vancomycin. Eighteen per cent believed that cefuroxime was used for prophylaxis. Forty-eight per cent of hospitals had an MRSA-free zone for orthopaedic patients. CONCLUSION: This study indicates a lack of uniformity in the perioperative management of MRSA-positive patients in the region and a lack of awareness of both MRSA guidelines and their implementation. Uniformity of MRSA guidelines is necessary to allow better clinician awareness and compliance, especially in surgical trainees who are travelling between different training hospitals in the region. Implementation of such a policy with re-audit of subsequent awareness and compliance is proposed.

Antibiotic Prophylaxis↗

Iatrogenic perforation in endoscopic stapling diverticulotomy for pharyngeal pouches.

In pharyngeal pouch surgery, the relatively new technique of endoscopic stapling diverticulotomy has a number of advantages over more traditional surgical treatments, such as Dohlman's procedure and open pouch excision, and now seems to be the procedure of choice. However, a number of iatrogenic perforations and deaths have been reported with this procedure. We present three cases of iatrogenic perforations occurring during endoscopic stapling of a pharyngeal pouch by different surgeons in our unit, and review the management, causes and prevention of this potentially life-threatening complication.

Aged↗

A retrospective comparison of endonasal KTP laser dacryocystorhinostomy versus external dacryocystorhinostomy.

We retrospectively reviewed all primary external dacryocystorhinostomies (DCRs) and endonasal KTP laser DCRs performed for epiphora as a result of nasolacrimal duct obstruction in our unit between 1993 and 2000. Forty-nine patients underwent an external approach and 76 endonasal laser procedures were performed. The success rate of the external group was 94% with a mean follow-up of 9 months. In contrast, the endonasal group's success rate was 64% with a mean follow-up of 12 months. This difference reached statistical significance (P = 0.0002). However, when including revision procedures, the success rate in the endonasal group increased from 64% to 82%. The success rate in the endonasal group improved from 50% in the first 38 cases to 79% in the last 38 cases (P = 0.0084), thereby demonstrating a learning curve. Our study confirms external DCR as the 'gold standard' for a successful outcome. However, the endonasal technique has significant advantages, including being a quicker procedure with less morbidity, no cutaneous scar, and being more amenable to a bilateral procedure, daycase surgery and local anaesthetic. We are persisting with the endonasal technique because of its advantages but have moved towards more 'cold steel' techniques in an effort to improve results and emulate other series. In conclusion, for nasolacrimal duct obstruction, the endonasal technique is our approach of choice, with revision surgery if necessary, and the external technique is held in reserve.

Adolescent↗

A retrospective review of pharyngeal pouch surgery in 56 patients.

We retrospectively reviewed 56 consecutive patients treated surgically for a pharyngeal pouch at our institution between 1989-1999 (10 years). Various surgical procedures were performed including endoscopic stapling (20), external excision (23), Dohlman's procedure (9), pouch inversion (3), cricopharyngeal myotomy only (3), and pouch suspension (1). There were 12 patients (18%) with complications and one mortality (2%). Four patients (7%) had a recurrence with 2 requiring further surgery. Over the latter 3 years, endoscopic stapling has emerged as the primary procedure for pharyngeal pouch surgery in our unit; with the advantages of an earlier commencement of diet and earlier hospital discharge. However, results were not as good as for external excisions. Furthermore, there were difficulties with 3 cases that commenced as endoscopic stapling procedures but had to he converted to external excisions due to inaccessibility in one case and iatrogenic perforations in two cases. As with any new technique, problems may occur and a learning curve has been appreciated in our unit. Surgeons must he prepared, with informed consent, to convert to an external approach should difficulties arise during endoscopic stapling. Elderly and frail patients who are at risk from a general anaesthetic may benefit from endoscopic stapling. External excision of pharyngeal pouches may be more appropriate in the young, the medically fit, and when malignancy is a concern.

Adult↗

Perioperative complications with costotransversectomy and anterior approaches to thoracic and thoracolumbar tumors.

OBJECT: Anterior decompression and stabilization for thoracic spinal tumors often involves a thoracotomy and can be associated with surgical approach-related complications. An alternative to thoracotomy is surgery via a costotransversectomy exposure. To delineate the risks of surgery, the authors reviewed their prospective database for patients who had undergone surgery via either of these approaches for thoracic or thoracolumbar tumors. The complications were recorded and graded based on severity and risk of impact on patient outcome. METHODS: Between September 1995 and April 2001, the authors performed 29 costotransversectomies (Group 1) and 18 thoracolumbar or combined (Group 2) approaches as initial operations for thoracic neoplasms. The age, sex, preoperative motor score, and preoperative Frankel grade did not significantly differ between the groups. In the costotransversectomy group there were greater numbers of metastases, upper thoracic procedures, and affected vertebral levels; additionally, the comorbidity rate based on Charlson score, was higher. The mean Frankel grades at discharge were not significantly different whereas the discharge motor and last follow-up motor scores were better in Group 2. There were 11 Group 1 and seven Group 2 patients who suffered at least one complication. The number or patients with complications, the mean number of complications, and severity of complications did not differ between the groups. CONCLUSIONS: Compared with anterior or combined approaches, the incidence and severity of perioperative complications in the surgical treatment of thoracic and thoracolumbar spinal tumors is similar in patients who undergo costotransversectomy. Costotransversectomy may be the preferred operation in patients with significant medical comorbidity or tumors involving more than one thoracic vertebra.

Adolescent↗

The response of human volunteers to rear-end impacts: the effect of head restraint properties.

STUDY DESIGN: Human volunteers were subjected to a rear-end impact while sitting on a standard automobile seat, and sagittal plane kinematic responses were quantified. The effect of changing head restraint properties was determined by use of a repeated measures design. OBJECTIVE: To determine the forces acting, and relative motions resulting, on volunteers in a rear-end impact and the effect of head restraint properties. SUMMARY OF BACKGROUND DATA: In several recent studies of the kinematics of the cervical spine during rear-end impact, a forward thrust to the lower cervical spine was produced, and a transient S shape of the spine resulted while the head remained upright during the initial phase of the impact. This may result in nonphysiologic intervertebral motions and tissue strains. METHODS: Nineteen automobile seats were first tested, and a modified head restraint was designed. Each volunteer sitting on a standard vehicle seat was subjected to an impact pulse of 3g with a 4-kph speed change. Testing was performed first with the modified head restraint, then again after replacement by the head restraint that came with the seat. Kinematic responses were compared for both head restraints by use of a repeated measures analysis of variance. RESULTS: There was a measurable time difference between peak chest and peak head accelerations, which resulted in the chest being thrust forward by the seat back before the head was thrust forward by the head restraint. The modified head restraint significantly reduced the contact time difference and therefore decreased the relative chest-to-head forward motion. CONCLUSIONS: Volunteers seated on a standard automobile seat demonstrated differential sagittal plane motion between the chest and head. It is possible to significantly decrease the relative chest-to-head motion by altering the characteristics of the head restraint.

Acceleration↗

Predictors of conversion of atrial fibrillation after cardiac operation in the absence of class I or III antiarrhythmic medications.

BACKGROUND: Although risk factors for the development of atrial fibrillation (AF) after cardiac operations have been studied extensively, predictors of conversion to sinus rhythm within 24 hours of onset have not been examined. METHODS: Eleven hundred consecutive adults undergoing cardiovascular operations from July 1997 to June 1998 were screened for new onset AF after operation. Patients with chronic persistent preoperative AF or those who died within 48 hours of the operation were excluded. RESULTS: Three hundred fifty-three patients develop

Adrenergic beta-Antagonists↗

Middle cranial fossa approach for the repair of spontaneous cerebrospinal fluid otorrhoea using autologous bone pate.

Tegmen plate defects causing cerebrospinal fluid (CSF) leaks and brain hernias have conventionally been repaired using soft tissue grafts by a transmastoid approach. A review of the literature reveals that the results of transmastoid repairs have been less than satisfactory. We present here four patients with spontaneous CSF otorrhoea who had tegmen defects repaired using the middle cranial fossa approach. An autologous bone pate slab mixed with fibrin glue with additional temporalis fascia reinforcement was used for the repairs. All four patients had uneventful postoperative periods and have had no subsequent CSF leak (follow-up range: 1-3 years). We believe that the middle cranial fossa approach is more effective than the transmastoid approach for the repair of CSF leaks and brain hernias through tegmen plate defects. An important additional benefit is hearing preservation. We also recommend the use of bone pate along with soft tissue for the repair in order to achieve a secure seal. Bone pate can effectively seal multiple defects in the tegmen plate without any risk of migration.

Adult↗

Characterization of binding of human lactoferrin to pneumococcal surface protein A.

Human lactoferrin is an iron-binding glycoprotein that is particularly prominent in exocrine secretions and leukocytes and is also found in serum, especially during inflammation. It is able to sequester iron from microbes and has immunomodulatory functions, including inhibition of both complement activation and cytokine production. This study used mutants lacking pneumococcal surface protein A (PspA) and PspC to demonstrate that the binding of human lactoferrin to the surface of Streptococcus pneumoniae was entirely dependent on PspA. Lactoferrin bound both family 1 and family 2 PspAs. Binding of lactoferrin to PspA was shown by surface colocalization with PspA and was verified by the lack of binding to PspA-negative mutants. Lactoferrin was expressed on the body of the cells but was largely absent from the poles. PspC showed exactly the same distribution on the pneumococcal surface as PspA but did not bind lactoferrin. PspA's binding site for lactoferrin was mapped using recombinant fragments of PspA of families 1 and 2. Binding of human lactoferrin was detected primarily in the C-terminal half of the alpha-helical domain of PspA (amino acids 167 to 288 of PspA/Rx1), with no binding to the N-terminal 115 amino acids in either strain. The interaction was highly specific. As observed previously, bovine lactoferrin bound poorly to PspA. Human transferrin did not bind PspA at all. The binding of lactoferrin to S. pneumoniae might provide a way for the bacteria to interfere with host immune functions or to aid in the acquisition of iron at the site of infection.

Animals↗

Mediastinal tuberculosis in a 10-month-old child.

We report a rare case of mediastinal tuberculosis in a child who presented as a possible inhaled foreign body. A 10-month-old girl was admitted with a five-month history of cough, wheeze and problematic feeding, thought initially to be due to asthma. A clinical deterioration and subsequent X-rays suggested an inhaled foreign body. However, at direct laryngotracheobronchoscopy no foreign body was found and subsequent investigations revealed a subcarinal mediastinal mass. She underwent a thoracotomy and excision of the mass, the histological analysis of which revealed it to be of tuberculous origin. When a patient presents with symptoms of upper airway obstruction which are highly suggestive of a foreign body, other causes such as mediastinal tuberculosis must be borne in mind when no foreign body can be found. Although rare, cases of tuberculosis are apparently increasing and the otolaryngologist must be aware of its various manifestations and submit specimens for appropriate analysis. We also briefly review mediastinal lymphadenopathy due to tuberculosis.

Bronchi↗