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Ahmed J, Abed T, Gatland DJ. Re: Superficial temporal vein graft in stapedotomy: a functional and aesthetic alternative. Clin Otolaryngol 2009; 34:79-80. [PMID: 19260898 DOI: 10.1111/j.1749-4486.2008.01842.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Suganthi P, Chadha VK, Ahmed J, Umadevi G, Kumar P, Srivastava R, Magesh V, Gupta J, Sharda MA. Health seeking and knowledge about tuberculosis among persons with pulmonary symptoms and tuberculosis cases in Bangalore slums. Int J Tuberc Lung Dis 2008; 12:1268-1273. [PMID: 18926036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
Abstract
SETTING Bangalore city slums, India. OBJECTIVES To ascertain 1) health-seeking behaviour patterns in persons with pulmonary symptoms; 2) pathways followed by pulmonary tuberculosis (PTB) cases until diagnosis and treatment; and 3) their knowledge about TB-symptoms, cause, mode of transmission, diagnosis and treatment. METHODS In selected slums, persons with pulmonary symptoms identified during house visits and residents with PTB were interviewed using pre-tested, semi-structured questionnaires. Visits to relevant health centres were made to obtain information regarding their treatment. RESULTS About 50% of the 124 persons with pulmonary symptoms interviewed had taken action for relief; of these, three quarters had first approached private health facilities. About 19% had undergone sputum microscopy and 27% chest X-ray. Of 47 PTB cases interviewed, 72% first approached private health facilities; about 50% visited two health facilities before diagnosis and 87% visited two or more facilities before initiating treatment; 42 initiated treatment at government health facilities and five who initiated treatment at private health facilities were later referred to government health facilities. The majority of persons with pulmonary symptoms and PTB cases had poor knowledge about TB, and most of those with pulmonary symptoms were not aware of the availability of free anti-tuberculosis services at government health facilities. CONCLUSION Educational interventions targeted at slum dwellers and their health providers are needed.
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Ahmed J, Ramesh B, Mahendrakar N. Changes in microbial population during fermentation of tropical freshwater fish viscera. ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1365-2672.1996.tb03203.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Gaur S, Shivhare U, Sarkar B, Ahmed J. Thermal Chlorophyll Degradation Kinetics of Mint Leaves Puree. INTERNATIONAL JOURNAL OF FOOD PROPERTIES 2007. [DOI: 10.1080/10942910601136450] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Chadha VK, Kumar P, Satyanarayana AVV, Chauhan LS, Gupta J, Singh S, Magesh V, Ahmed J, Srivastava R, Suganthi P, Devi GU. Annual risk of tuberculous infection in Andhra Pradesh, India. Indian J Tuberc 2007; 54:177-183. [PMID: 18072530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
BACKGROUND There is paucity of information on epidemiological situation of Tuberculosis (TB) in Andhra Pradesh. The DOTS strategy under the Revised National Tuberculosis Control Programme (RNTCP) was introduced in the year 2000 to cover the entire State by 2005. OBJECTIVES To estimate the prevalence of tuberculous infection among children 5-9 years of age and to compute the average Annual Risk of Tuberculosis Infection (ARTI) from the estimated prevalence. METHODS A cluster-sample house-based tuberculin survey was carried out in a representative sample of children between 5-9 years of age. The clusters were selected by a two-stage sampling procedure. At first stage, five districts were selected by probability proportional to population size (PPS) method. Depending upon child population ratio, 32 clusters allocated to each district were further sub-divided into rural and urban clusters selected by simple random sampling. A total of 3636 children, irrespective of their BCG scar status, were tuberculin tested using one TU PPD RT23 with Tween 80 and the maximum transverse diameter of induration was measured about 72 hours later. RESULTS The prevalence of infection estimated by mirror-image technique using observed mode of reactions attributable to infection with tubercle bacilli at 20mm was 9.6% (95% CI: 8.0-11.2). The ARTI was computed at 1.4% (95% CI: 1.1-1.6). CONCLUSION Survey findings indicate a fairly high rate of transmission of tubercle bacilli.
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Ahmed J, Chuckwulobelu R, Sebire N, Hartley B, Dunaway D. Hemimandibulectomy and autologous costochondral rib graft reconstruction for a case of melanotic neuroectodermal tumour of infancy arising within the mandible. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/j.pedex.2007.05.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Ahmed J, De S, Hore IDB, Bailey CM, Hartley BEJ. Treatment of piriform fossa sinuses with monopolar diathermy. The Journal of Laryngology & Otology 2007; 122:840-4. [PMID: 17666142 DOI: 10.1017/s0022215107000291] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractIntroduction:Embryological remnants of third or fourth branchial pouches are a rare but important cause of recurrent neck abscesses in children. They are characterised by an internal opening in the piriform fossa. Traditional management involves surgical excision of the entire tract. We present our experience with the use of monopolar diathermy applied to the internal sinus opening as a treatment modality for this condition.Materials and methods:A retrospective, case report review was performed.Results:Four cases of piriform fossa sinus were treated with monopolar diathermy to the sinus opening via an endoscopic approach. The first three cases were treated in this way for recurrence, following external tract excision, while the fourth case had simultaneous excision of the tract and diathermy to the piriform fossa opening. There were no serious complications and no recurrence within a follow-up period ranging from nine to 27 months.Discussion:Obliteration of the internal opening of these sinuses by endoscopic diathermy is a safe and effective management option for this condition, either as an alternative to or as an adjunct to external surgical excision of the tract.
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Harper PL, Theakston E, Ahmed J, Ockelford P. D-dimer concentration increases with age reducing the clinical value of the D-dimer assay in the elderly. Intern Med J 2007; 37:607-13. [PMID: 17543005 DOI: 10.1111/j.1445-5994.2007.01388.x] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND The D-dimer assay is used as an exclusion test in the assessment of suspected venous thromboembolic disease; patients with a negative result have a low probability of thrombosis. We reviewed the D-dimer results from a hospital and community laboratory using the vidas D-dimer test to assess the influence of age on the D-dimer assay. METHODS D-dimer results from 6631 unselected patients aged more than 16 years were analysed in four age groups and it was shown that the median D-dimer concentration increased with age (16-40 years, 294 ng/mL; 40-60 years, 387 ng/mL; 60-80 years; 854 ng/mL; >80 years, 1397 ng/mL). To test the effect of age on the assay specificity, a cohort of 1897 patients with suspected venous thromboembolic disease was analysed separately. Patients with a negative D-dimer were discharged without further investigation. Patients with a positive result and a clinical suspicion of thrombosis underwent further investigation. One hundred and sixty-five deep vein thrombosis or pulmonary embolus cases were identified. RESULTS The assay specificity decreased with age from 70% in patients less than 40 years to below 5% in patients more than 80 years. Receiver operator curves were prepared for each age group and the effect of altering the threshold value was analysed. In patients 60-80 years old a threshold value of 1000 ng/mL increased assay specificity to 55% without loss of assay sensitivity. CONCLUSION The vidas D-dimer assay with a threshold value of 500 ng/mL has little clinical value as an exclusion test in patients more than 80 years old. The assay specificity is poor (26%) in patients aged 60-80 years but could be improved by increasing the threshold value to 1000 ng/mL. We believe that this should be tested in a prospective trial.
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Mohsin N, Budruddin M, Khalil M, Pakkyarra A, Jha A, Mohammed E, Kamble P, Ahmed H, Militsala E, Prabhakar NA, Al-Marhuby H, Ahmed J, Daar A. Donor Gender Balance in a Living-Related Kidney Transplantation Program in Oman. Transplant Proc 2007; 39:803-6. [PMID: 17524816 DOI: 10.1016/j.transproceed.2007.04.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
It has been observed in several Eastern and Western countries that there is a gender imbalance among kidney donors. In the international experience, approximately 65% of live kidney donors have been women. We retrospectively studied the distribution of female and male donors or recipients among living kidney transplantations performed from 1980 to 2005, namely 198 Omani recipients of living-related kidney transplantations. To examine cultural influences, transplantations performed or expatriates were excluded from the study. For the whole period, 98 out of 198 donors (49.5%) were women. The number of female recipients 75 of 198 (38%) versus males were 123 (62%) recipients. We then subdivided the period into three intervals: 1980 to 1990, 1991 to 2000, and 2001 to 2005. The numbers of female donors for these three periods were 29 of 64 (45%), 42 of 89 (47%), and 27 of 45 (60%), respectively. There was a persistent preponderance of male recipients ranging from 58% to 66% during these periods. We concluded that there was no gender imbalance for kidney donors. Nevertheless, there was a male preponderance in the recipient group.
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Mohsin N, Budruddin M, Kamble P, Khalil M, Pakkyarra A, Jha A, Mohammed E, Ahmed H, Ahmed J, Thomas S, Campistol JM, Daar A. Complete Regression of Cutaneous B-Cell Lymphoma in a Renal Transplant Patient After Conversion From Cyclosporin to Sirolimus. Transplant Proc 2007; 39:1267-71. [PMID: 17524950 DOI: 10.1016/j.transproceed.2007.03.092] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Posttransplant lymphoproliferative disease remains a serious morbidity. Herein we have reported a case of complete regression of a biopsy-proven B-cell lymphoma that occurred in the posttransplant period. A 48-year-old man received a living donor renal transplant for end-stage renal disease due to undetermined etiology. His initial immunosuppression consisted of corticosteroid, mycophenolate mofetil, and cyclosporin. The patient developed severe pneumonia within the first 2 months after transplantation due to Acineotobacter, fungus, and cytomegalovirus infections. He experienced a complete recovery and was discharged for regional follow-up. Four months after discharge, he was referred again because of presence of two nodules on his trunk. A biopsy of the nodules revealed B-cell lymphoma. Cyclosporin was stopped and he was converted to sirolimus. The lesions regressed progressively and completely within 7 weeks. The patient remains well without clinical relapses at 19 months after conversion. Renal functions remained stable. We postulated that the antincoplastic properties of sirolimus may have played an active part in the positive outcome.
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Nouraei SAR, Al-Yaghchi C, Ahmed J, Kirkpatrick N, Mansuri S, Singh A, Grant WE. An anatomical comparison of Blair and facelift incisions for parotid surgery. Clin Otolaryngol 2007; 31:531-4. [PMID: 17184460 DOI: 10.1111/j.1365-2273.2006.01334.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND The rhytidectomy approach for parotidectomy allows the incision to be hidden, and post-operative scarring minimised. Furthermore, separate elevation of the Superficial Musculo-Aponeurotic System (SMAS) reduces the incidence of Frey's syndrome, and provides vascularized soft tissue for contour reconstruction. The technique has gained popularity particularly with plastic surgeons, but concerns persist that with this approach, particularly with lesions located anteriorly, access to the gland may be inadequate, and facial nerve identification may be compromised. MATERIALS AND METHODS We undertook an anatomical study to quantitatively compare the surgical access achieved using the facelift approach with the conventional Blair incision, by comparing the distances between the parotid edge and the retracted flaps. RESULTS Despite reduced tissue elasticity due to formaldehyde fixation, it proved possible to demonstrate all regions of the parotid gland to the operating surgeon with either approach. There were no significant differences in the distance between the parotid edge and the retracted skin flaps (P > 0.1; paired t-test). CONCLUSIONS The facelift approach provides at least equal access to all regions of the parotid gland when compared to a Blair's incision. It is a superior approach aesthetically and its more widespread use in parotid surgery is advocated.
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Obholzer RJ, Nouraei SAR, Ahmed J, Kadhim MR, Sandhu GS. An approach to the management of paroxysmal laryngospasm. The Journal of Laryngology & Otology 2007; 122:57-60. [PMID: 17319986 DOI: 10.1017/s0022215107005907] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVE To review the presentation, risk factors and management of paroxysmal laryngospasm. STUDY DESIGN Retrospective review of cases. SETTING A teaching hospital otolaryngology department with a subspecialty interest in airway disorders. PATIENTS All patients diagnosed with laryngospasm over a two-year period were reviewed. Information was obtained about disease presentation, risk factors, management and symptom resolution. RESULTS Laryngospasm was diagnosed in nine women and six men. The average age at presentation was 56+/-6.5 years, and there was an 80 per cent association with gastroesophageal reflux disease. Proton pump inhibitors led to complete symptom resolution in six patients and to partial symptomatic relief, requiring no further treatment, in a further four patients. Of the remaining five patients unresponsive to proton pump inhibitor therapy, two continued to experience syncopal episodes due to laryngospasm. Both these patients achieved complete remission after laryngeal botulinum toxin injection. Symptoms recurred after three to four months and were successfully treated with a repeat injection. CONCLUSIONS The primary risk factor for spontaneous laryngospasm is laryngopharyngeal reflux. Symptoms are distressing and may be relieved in most cases by treatment aimed at suppressing gastric acid secretion. Laryngeal botulinum toxin injection appears to be a viable treatment modality in selected patients with refractory symptoms.
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Ahmed J, Ruygrok P, Wilson N, Webster M, Greaves S, Gerber I. Percutaneous Closure of Post Myocardial Infarction Ventricular Septal Defects. Heart Lung Circ 2007. [DOI: 10.1016/j.hlc.2007.06.340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Humphreys GS, Merinopoulos I, Ahmed J, Whitty CJM, Mutabingwa TK, Sutherland CJ, Hallett RL. Amodiaquine and artemether-lumefantrine select distinct alleles of the Plasmodium falciparum mdr1 gene in Tanzanian children treated for uncomplicated malaria. Antimicrob Agents Chemother 2006; 51:991-7. [PMID: 17194834 PMCID: PMC1803116 DOI: 10.1128/aac.00875-06] [Citation(s) in RCA: 187] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The artemisinin-based combination therapies artemether-lumefantrine (AL) and amodiaquine (AQ) plus artesunate have been adopted for treatment of Plasmodium falciparum malaria in many African countries. Molecular markers of parasite resistance suitable for surveillance have not been established for any of the component drugs in either of these combinations. We assessed P. falciparum mdr1 (Pfmdr1) alleles present in 300 Tanzanian children presenting with uncomplicated falciparum malaria, who were enrolled in a clinical trial of antimalarial therapy. Pfmdr1 genotype analysis was also performed with isolates from 182 children who failed AQ monotherapy and 54 children who failed AL treatment. Pfmdr1 alleles 86Y, 184Y, and 1246Y were more common among treatment failures in the AQ group than among pretreatment infections. The converse was found in the AL-treated group. Children presenting with the 86Y/184Y/1246Y Pfmdr1 haplotype and treated with AQ were significantly more likely to retain this haplotype if they were parasite positive during posttreatment follow-up than were children treated with AL (odds ratio, 33.25; 95% confidence interval, 4.17 to 1441; P, <0.001). We conclude that AL and AQ exert opposite within-host selective effects on the Pfmdr1 gene of P. falciparum.
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Akoad M, Wagener M, Francis F, Ahmed J, Ulizio D, Cacciarelli TV. Outcome of Imported Liver Allografts and Impact on Patient Access to Liver Transplantation. Transplant Proc 2006; 38:3564-6. [PMID: 17175332 DOI: 10.1016/j.transproceed.2006.10.037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2006] [Indexed: 01/07/2023]
Abstract
Liver allografts declined by local transplant centers are then offered regionally or nationally as imported grafts. Most of these grafts are declined because of poor donor quality. We retrospectively reviewed the medical records of patients who underwent liver transplantation between January 2004 and December 2005. There were 102 liver transplants in 98 recipients. They were divided into two groups: imported graft recipients (n = 37) and locally procured grafts recipients (n = 61). Eighty-six percent (32 of 37) of imported grafts were obtained from extended criteria donors defined as subjects treated with high doses of ionotropes with elevated liver enzymes, donor age over 70 years, macrosteatosis above 25%, positive hepatitis C or hepatitis B core antibody serology, systemic disease, history of cancer, hypernatremia, or with infection. The remaining grafts were declined due to unavailability of suitable recipients or social history. Recipient age and etiology of liver disease were similar for both groups. The mean MELD score was 22.1 +/- .9 among the imported graft recipients and 26.1 +/- 1 for the locally procured graft recipients (P < .01). There was no difference in blood loss or postoperative complications. Postoperative mean peak total bilirubin was similar in both groups. However, imported graft recipients had significantly higher mean peak AST (2436 +/- 282 vs 1380 +/- 165 U/L, P < .001) and ALT (1098 +/- 114 vs 803 +/- 87 U/L, P < .05). Primary graft nonfunction as well as 30 day and 1-year patient and graft survivals were similar for both groups. In conclusion, imported grafts can be transplanted in selected patients with outcomes comparable to locally procured grafts.
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Al-Hussaini M, Abu-Abeeleh M, Saleh S, Ahmed J. MICE: a potential histopathological pitfall. Pathology 2006; 38:471-3. [PMID: 17008296 DOI: 10.1080/00313020600922421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Ahmed J, Chatrath P, Harcourt J. A bifid intra-tympanic facial nerve in association with a normal stapes. The Journal of Laryngology & Otology 2006; 120:414-5. [PMID: 16696883 DOI: 10.1017/s0022215106000570] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/25/2005] [Indexed: 11/07/2022]
Abstract
A rare facial nerve anomaly was incidentally discovered whilst performing a tympanoplasty and ossicular reconstruction on a patient with an acquired unilateral conductive hearing loss. The nerve was seen to bifurcate and straddle a normal stapes superstructure as it ran posteriorly through the middle ear, a unique and as yet unreported combination. This case highlights the importance of vigilance regarding facial nerve anatomical variations encountered during middle-ear surgery thus avoiding inadvertent damage. The purported embryological mechanism responsible for such anomalies of the intra-tympanic facial nerve is discussed.
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Lynn CN, Ahmed J. A technique for tracking intravascular fluorescent microspheres for the determination of arteriolar blood flow in rats. BIOMEDICAL SCIENCES INSTRUMENTATION 2006; 42:90-5. [PMID: 16817591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Fluorescent microspheres have been used in multiple particle tracking studies. Our laboratory is working towards the use of fluorescent microsphere particle tracking in the study of the retinal circulation. The first stage of this project was to develop a technique for measurement and analysis of the particle tracking data. We intravenously injected 2.0 microm diameter, polystyrene microspheres, labeled with fluorescent dye, in anesthetized rats. Using a microscope with a fluorescence attachment, we viewed the fluorescent particles flowing through the surface vessels of the intestine. Data was recorded then analyzed frame by frame. The path of each microsphere was plotted on a transparency sheet and measured. Using a magnification ratio, the velocity and blood flow rate were calculated for 235 particles in five different blood vessels. We found this technique to be an effective method for studying blood flow in an arteriole. The results were comparable to other blood flow studies and showed characteristic trends of typical laminar blood flow.
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Ahmed J, Philpott J, Lew-Gor S, Blunt D. Airway obstruction: a rare complication of thrombolytic therapy. The Journal of Laryngology & Otology 2005; 119:819-21. [PMID: 16259662 DOI: 10.1258/002221505774481264] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Bleeding into head and neck structures as a complication of thrombolysis is extremely rare but potentially lethal. It is usually associated with local trauma. We describe a case of a 67-year-old woman who developed spontaneous, massive pan aerodigestive tract haemorrhage precipitating airway obstruction following administration of streptokinase for myocardial infarction; a previously unreported complication. This case highlights the importance of being vigilant of airway symptoms following such treatment, prompting early involvement of anaesthetic and otolaryngology personnel.
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Ahmed J, Ramaswamy H. Effect of Temperature on Dynamic Rheology and Colour Degradation Kinetics of Date Paste. FOOD AND BIOPRODUCTS PROCESSING 2005. [DOI: 10.1205/fbp.04312] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Lukas SJ, Ahmed J. Selective protein adsorption on micro-textured P-type and N-type silicon wafers. BIOMEDICAL SCIENCES INSTRUMENTATION 2005; 41:181-6. [PMID: 15850102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
There has recently been a great deal of effort put towards the development of bioMEMS-based electrochemical biosensors for use in implantable devices. Currently, the primary issue limiting the lifespan of implantable sensors is protein and cell adhesion (biofouling) to the sensor surface, which impedes the sensor's access to analyte. To better understand this problem, it would be useful to have an understanding of how silicon-based microdevices interact with proteins in a physiological environment. To help answer this question, we investigated the interactions of proteins with microtextured silicon wafers. Bulk micromachining techniques were used to create micro-textures that varied between 5 and 80 microns in size nd spacing. We used n-type and p-type silicon wafers with a <100> crystal orientation. Shapes such as rectangles, circles, and triangles were fabricated that were recessed into the silicon substrate. The features were estimated to be between 3 and 8 microns in depth. After the features were created, the wafers were coated with a layer of silicon dioxide. Once fabrication was complete, the wafers were incubated in vitro ith fluorescently tagged Albumin (500 microg/ml in Phosphate-Buffered Saline, PBS) for 5 minutes. The wafers were then rinsed with PBS solution and viewed using an epifluorescence microscope. Albumin adsorbed selectively onto the micropatterned wafers. Depending on the type of wafer we found that albumin adsorbed selectively onto either the bulk surface, the sidewalls, or the bottom of the etched feature.
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Kahlert H, Weber B, Suck R, Cromwell O, Fiebig H, Kleinhans D, Blume C, Lindner B, Becker WM, Petersen A, Sander I, van Kampen V, Fleischer C, Meurer U, Brüning T, Merget R, Raulf-Heimsoth M, Boldt A, Ballmer-Weber B, Darcan Y, Galle J, Ahmed J, Seitzer U, Fölster-Holst R, Jensen JM, Frinken AL, Ho H, Stick C, von Wahl PG, Ott H, Wurpts G, Krieg R, Al Masaoudi T, Joussen S, Kiehl K, Neis M, Merk HF, Baron JM, Rihs HP, Kowal A, Degens PO, Landt O, Mariani V, Jakob T, Ring J, Behrendt H, Traidl-Hoffmann C, Wicklein D, Stöcker M, Klockenbring T, Huhn M, Barth S, Schürer NY, Sudowe S, Zindler E, Ludwig-Portugall I, Montermann E, Ross R, Reske-Kunz AB, Fang J, Ambach A, König W, Bonnekoh B, Gollnick H, König B, Bellinghausen I, Böttcher I, Knop J, Saloga J, Kurek M, Maleszka R, Staszyńska-Kurek M, Załuga E, Biedermann T, Günther C, Tangemann K, Schwärzler C, Lametschwandtner G, Rot A, Carballido JM, Pommer AJ, Böckelmann R, Malykh Y, Philipsen L, Schubert W, Schupp P, Gutgesell C, Fuchs T. Freie Vorträge. ALLERGO JOURNAL 2004. [DOI: 10.1007/bf03371917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Chen HC, Ahmed J. Design and testing of a fluorescence glucose sensor which incorporates a bioinductive material. BIOMEDICAL SCIENCES INSTRUMENTATION 2004; 40:149-54. [PMID: 15133950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
One main hurdle in the development of implantable biosensors is that their lifetime is limited by scar tissue formation around the implant. One way to ameliorate this issue would be to use a bioinductive coating to allow normal tissue ingrowth around the sensor. Here, we report design, development and in vitro testing of a prototype fluorescence-based glucose sensor that incorporates a bioinductive material at its tip. Glucose is sensed via a fluorescence-based assay system (Amplex reagent) which is confined to a small chamber separated from the bulk glucose solution by a semipermeable membrane. Excitation is provided by a 530 nm laser, while the emitted light is detected by a photomultiplier tube. In vitro testing of this prototype was done in the presence and absence of a bioinductive material covering the membrane at the sensor/solution interface. In response to a step change in glucose concentration, the output of the sensor increased linearly over time due to accumulation of fluorescent marker molecules as glucose diffused into the recording chamber. The slope of this response increased linearly with increasing glucose concentration, with a sensitivity if 2.1 x 10(-4) V/min per ml glucose/dl solution. The presence of the bioinductive layer did not alter the function of the sensor at the lowest glucose concentrations tested, although responses to higher concentrations saturated, presumably because of depletion of the Amplex reagent within the chamber. In summary, we report that the use of a bioinductive material in an implantable biosensor does not appreciably alter sensor function.
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Ahmed J, Zaman MM, Keramat Ali SM. Identification of serogroups of beta hemolytic streptococci in children with tonsillo-pharyngitis. BANGLADESH MEDICAL RESEARCH COUNCIL BULLETIN 2003; 29:113-7. [PMID: 15053273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Rheumatic fever and post streptococcal glomerulonephritis are common sequelae of beta hemolytic streptococci among Bangladeshi children. The occurrence of these serious complications of beta hemolytic streptococcal throat infections are related to the epidemiology of group A beta hemolytic streptococci. Little is known about the epidemiology of beta hemolytic streptococci in Bangladesh. We have studied 6890 school boys and girls of Narayangonj to find out the prevalence of beta hemolytic streptococcal infections of throat. From them we selected 2175 children, who were suffering from tonsillo-pharyngitis. This cross sectional study was conducted during March-December 1999. All statistical analysis was done by using statistical package SPSS windows version 8. The mean (SD) age of the children was 11.1 (3.3) years. Four hundred and twenty eight isolates of beta hemolytic streptococci were recovered from tonsillo-pharyngeal swab cultures obtained from 428 children. Among the isolated beta hemolytic streptococci, 92 (21.5%) belonged to group A, 5 (1.2%) to group B, 14 (3.3%) to group C and 317 (74.0%) to group G. These findings demonstrated the predominance of group G followed by A infection among school children. Therefore special attention should be paid not only to group A but also to group G. Further studies to determine prevalence of M serotypes are necessary.
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Ahmed J, Zaman MM, Ali K. Antioxidant vitamins improves hemoglobin level in children with group a beta hemolytic streptococcal infection. Mymensingh Med J 2003; 12:120-3. [PMID: 12894046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
A study was done on school children infected with group A beta hemolytic streptococci to examine whether antioxidant vitamins play a role in improving the hemoglobin level. A total of 606 primary school children aged 5 to 15 years were randomly divided into two intervention groups. Group 1 (n=299) was treated with pehnoxymethyl penicillin V and group 2 (n=307) was treated with phenoxymethyl penicillin V plus antioxidant vitamins for eight weeks. From each group two blood samples were drawn in acute and convalescent (after eight weeks) states. Before treatment, mean hemoglobin values were 11.0 and 10.8 mg/dL in groups 1 and 2 respectively. After treatment hemoglobin values were 10.5 and 11.6 mg/dL respectively. Values were significantly decreased in group 1 (P=0.0001), whereas increased in group 2 (P=0.001). Adjustment for age and sex by ANCOVA confirmed the difference in hemoglobin levels between group (LS means-0.5 vs 0.8 in groups 1 and 2 respectively (P=0.0001). Hemoglobin level increases after antioxidant vitamin supplementation in children suffering from group A beta hemolytic streptococcal infection.
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