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Biomedical subjects

S Ahmed

Publications and source records attributed to S Ahmed.

At least 37 records · Page 2Linked to original sources
PubMed2005

Reaming during anterograde femoral nailing: is it worth it?

A systematic review was performed to assess the relative merits of reamed and unreamed antegrade femoral nailing. To be included, a study had to be prospective, randomised or pseudorandomised, comparing reamed and unreamed antegrade femoral nailing in adults. Where more than one study from the same institution was available, only the study with longest follow-up was included. A literature search found 2044 possible articles. Of these, eight studies compared reamed and unreamed femoral nailing. The methodology of these articles was independently assessed by all the three authors. Five studies met the inclusion criteria. Each outcome measure tested was assessed for heterogeneity. If significant heterogeneity was present, the data were not combined. If there was no significant heterogeneity, a combined odds ratio or weighted mean difference was calculated using a fixed effects model, and a Z-test was performed to test the overall effect. Six hundred and forty-seven femoral fractures (315 reamed; 332 unreamed) were entered into the included studies. Unreamed nailing was quicker and associated with significantly less blood loss (P < 0.00001). Reaming significantly reduced the time to union (P = 0.00001), non-union (P = 0.002), delayed union (P = 0.005), technical problems (P = 0.01) and reoperation rate (P = 0.001). The use of reamed femoral nails gives significant advantages over unreamed femoral nails.

Adult↗
PubMed2005

Patient notification exercise following a dentist's admission of the periodic use of unsterilized equipment.

During 2001, Greater Glasgow National Health Service (NHS) Board undertook a patient notification exercise in a Glasgow dental practice following the admission, by the dentist, of the use of unsterilized dental equipment on patients. Four thousand and eighty-nine exposed patients were identified; of these, 1696 contacted the NHS helpline and 1005 were counselled and screened for hepatitis C virus (HCV), hepatitis B virus (HBV) and human immunodeficiency virus. One patient showed evidence of previous HBV infection and 13 had antibodies to HCV. Molecular investigation of the HCV isolates indicated no significant associations. The investigation found no evidence of patient-to-patient transmission of HCV among patients attending the practice of a dentist who admitted periodically using unsterilized equipment.

Contact Tracing↗
PubMed2005

Natural killer cells in breast cancer cell growth and metastasis in SCID mice.

Natural killer (NK) cell is an important component of the innate immune system and plays a central role in host defense against tumor and virus-infected cells. This review briefly summarizes the role of murine NK cells in tumor growth and metastasis of breast cancer cells in severe combined immunodeficiency (SCID) mice. Conventional SCID and NOD-SCID strains have been used to study for xenotransplantion of human tumors. SCID mice models of cancer mimic human diseases and have provided valuable information. However, these mice strains have some residual immunity such as NK cells that somewhat limit post-transplantation growth and metastasis of human xenografts. In contrast, NOD/SCID/gammac(null) (NOG) mice without common gamma-chain inoculated with breast cancer cells were most efficient in the formation of a large tumor and metastasis. NOG mouse strain without NK activity appears to be more promising as tool for xenotransplantion of human cancer. This new xenotransplant model is relevant and can be recommended for use in clarifying the mechanism of growth of cancer cells as well as for developing new therapeutic strategies against cancer.

Animals↗
PubMed2005

A comparison of lidocaine 2% with levobupivacaine 0.75% for sub-Tenon's block.

BACKGROUND AND OBJECTIVE: To compare the onset of action, and quality of block, of lidocaine 2% with levobupivacaine 0.75% for sub-Tenon's block in patients undergoing cataract surgery. METHODS: We performed a two-centre trial in 91 patients who were randomized to receive 4 mL of lidocaine 2% (n = 44) or levobupivacaine 0.75% (n = 47) for sub-Tenon's block, both with hyaluronidase 15 IUmL(-1). Onset of akinesia was assessed every 2 min for 10 min. Numbers of patients requiring supplementary injections to achieve clinically satisfactory akinesia or rescue analgesia were recorded. Data were analyzed with Fisher's exact test, U-test and t-test where appropriate. Results were considered significant when P < 0.05. RESULTS: The speed of onset was statistically significantly faster for lidocaine compared to levobupivacaine (3.02 vs. 5.06 min, P < 0.001). There was no statistical difference in number of patients requiring a supplementary injection of local anaesthetic (levobupivacaine 3 vs. lidocaine 0, P = 0.24), rescue analgesia with topical tetracaine (levobupivacaine 0 vs. lidocaine 2, P = 0.5), or ocular akinesia scores at the completion of surgery (lidocaine 1.4 vs. levobupivacaine 1.6, P = 0.12). Pain scores measured by a verbal analogue scale were not significantly different for injection, perioperatively or postoperatively. CONCLUSIONS: Both agents produce a rapid onset of anaesthesia when used for sub-Tenon's block. The difference between the two agents, although statistically significant, is not clinically important.

Aged↗
PubMed2005

Severe illness and death among injecting drug users in Scotland: a case-control study.

Between April and September 2000, 60 injecting drug users in Scotland died or were hospitalized with severe illness. Laboratory investigations suggested that Clostridium novyi and other bacteria were important aetiological agents. To determine associated environmental/behavioural factors a case-control study was undertaken with 19 'definite' and 32 'probable' cases in Glasgow, Scotland. For every deceased case (n=19), up to three proxy individuals were interviewed. Three controls were identified for each case. Multivariate logistic regression analyses compared (i) all cases and controls; (ii) definite cases and matched controls; (iii) probable cases and matched controls. In all three analyses injecting into muscle or skin and injecting most of the time with a filter used by someone else were the variables most strongly associated with illness. Comparing only muscle-injecting cases and controls, cases were significantly more likely to have injected larger amounts of heroin per average injection than were controls. The findings make an important epidemiological contribution to the understanding of the public health and clinical implications of the contamination of illicit drugs by histotoxic clostridia.

Adult↗
PubMed2005

Salvage cryosurgery for locally recurrent prostate cancer following radiotherapy.

The popularity of radiotherapy as a minimally invasive treatment for prostate cancer is increasing. Despite advancements in radiation delivery, a number of patients will fail treatment. Salvage radical prostatectomy has been the main therapeutic option for locally recurrent radiation failure prostate cancer with curative intent. The operation is technically difficult to perform and associated with significant comorbidities. Salvage cryotherapy has emerged as a minimally invasive alternative option. In this article, we review the role of cryotherapy in recurrent prostate cancer and compare its outcome with salvage radical prostatectomy.

Cryosurgery↗
PubMed2005

A longitudinal study of the incidence of major endemic and epidemic diseases affecting semi-scavenging chickens reared under the Participatory Livestock Development Project areas in Bangladesh.

A 17-month (from January 2002 to May 2003) longitudinal study was undertaken to elucidate the epidemiology of important endemic and epidemic diseases affecting semi-scavenging chickens reared in the Participatory Livestock Development Project area in Bangladesh. This project was implemented in 17 northern and north-central districts of Bangladesh, under which 361 839 rural poor people were assisted to undertake poultry-rearing activity as a tool of poverty reduction. Of the total beneficiaries 93% were "key rearers". A key rearer is defined as a beneficiary who generally rears 10 to 13 hens in a semi-scavenging system with little additional feed supply. Households of 650 key rearers and some chick rearers were observed. During the study period 1227 birds, which belonged to different age, breed and sex categories, were found dead as a result of disease occurrence. From every dead bird organ samples such as the liver, heart, spleen, brain lung, trachea and bursa of Fabricius were collected. The incidence rate of mortality was 0.01976 per bird-months at risk. Of the total deaths 58.44% had single or mixed type of infections. Newcastle disease had the highest proportional mortality rate (15.81%). The proportional mortality caused by fowlpox, fowl cholera, salmonellosis, colibacillosis, aspergillosis, infectious bursal disease, mixed infections and undiagnosed cases were 8.96%, 6.76%, 7.09%, 6.93%, 0.33%, 2.04%, 10.51% and 41.56%, respectively. Newcastle disease affected a significant higher proportion (18.81%) of birds older than 60 days of age (P=0.00). Younger birds (age < or = 60 days) had a higher proportional mortality due to fowlpox and infectious bursal disease than older birds (P=0.00). Sonali (male Rhode Island Red x female Fayoumi) birds reared under the semi-scavenging system had a higher infection rate with Newcastle disease virus compared with indigenous and Fayoumi birds (P=0.00). Fowlpox was more prevalent in Fayoumi birds compared with Sonali. Surprisingly, Newcastle disease was more common in the vaccinated birds rather than the unvaccinated birds.

Age Factors↗
PubMed2005

Prevalence of, and risk factors for, hepatitis C virus infection among recent initiates to injecting in London and Glasgow: cross sectional analysis.

Our aim was to compare the prevalence of antibody to hepatitis C virus (anti-HCV) among recently initiated injecting drug users (IDUs) in London and Glasgow, and to identify risk factors which could explain differences in prevalence between the cities. Complementary studies of community recruited IDUs who had initiated injection drug use since 1996 were conducted during 2001-2002. Data on HCV risk behaviours were gathered using structured questionnaires with identical core questions and respondents were asked to provide an oral fluid specimen which was tested anonymously for anti-HCV but was linked to the questionnaire. Sensitivities of the anti-HCV assays for oral fluid were 92-96%. Prevalence of anti-HCV was 35% (122/354) in London and 57% (207/366) in Glasgow (P < 0.001). Multifactorially, factors significantly associated with raised odds of anti-HCV positivity were increasing length of injecting career, daily injection, polydrug use, having had a needlestick injury, and having served a prison sentence. In addition lower odds of anti-HCV positivity were associated with non-injection use of crack cocaine and recruitment from drug agencies. After adjustment for these factors, the increased odds of anti-HCV associated with being a Glasgow IDU were diminished but remained significant. HCV continues to be transmitted among the IDU population of both cities at high rates despite the availability of syringe exchange and methadone maintenance. Effectiveness of harm reduction interventions may be compromised by inadequate coverage and failure to reduce sufficiently the frequency of sharing different types of injecting equipment, as well as the high background prevalence of HCV, and its high infectivity. Comprehensive action is urgently required to reduce the incidence of HCV among injectors.

Adult↗
PubMed2005

Microarray profiling of colorectal cancer in Bangladeshi patients.

OBJECTIVE: We have carried out a retrospective analysis of all cases of colorectal cancer at the Royal London Hospital between April 1998 and March 2002 and determined the differences in presentation and outcome between Bangladeshi and Non-Bangladeshi patients. DNA microarrays were used to explain any potential genetic differences between these two groups that may explain the different phenotypes. MATERIALS AND METHODS: We examined the colorectal database at our institution. Microarray profiles, using Affymetrix HU133A Genechips (Santa Clara, CA USA) were obtained from 10 Bangladeshi patients and an age-, sex- and stage-matched group of 10 Non-Bangladeshi patients. RESULTS: Three hundred and sixty-three patients have been treated for colorectal cancer at the Royal London Hospital. Eighteen (5%) patients were of Bangladeshi origin. The prevalence was 27/100,000 compared to 342/100,000 of the Non-Bangladeshi population. Eleven (61%) of 18 Bangladeshi patients were under the age of 40 and 4 (22%) patients presented with locally advanced or metastatic disease. In comparison 39/345 (11%) of non-Bangladeshi patients presented with advanced disease. None of the Bangladeshi patients gave a positive family history. Microarray profiling between these two groups demonstrated 1203 differentially expressed genes (P < 0.05). CONCLUSION: Colorectal cancer is uncommon in the Bangladeshi patients compared to the non-Bangladeshi population. This cancer presents in younger patients and at a more advanced stage. There is no positive family history within this ethnic community and therefore the cancers are sporadic. However, microarray profiling is able to delineate different gene expression between these two groups. Therefore, there should be a low threshold for investigating young Bangladeshi patients with symptoms of colorectal neoplasia and any future national screening programme should allow for ethnic variation.

Adult↗
PubMed2005

Plasma nitrotyrosine in reversible myocardial ischaemia.

BACKGROUND: Nitric oxide (NO) plays a vital role in vascular homeostasis and in the pathophysiology of coronary heart disease. Its metabolites, nitrite and nitrate, have vasculoprotective properties, whereas peroxynitrite, an oxidant metabolite of NO, is cytotoxic and can aggravate myocardial damage during ischaemic reperfusion injury. Peroxynitrite nitrates free and protein bound tyrosine residues to produce nitrotyrosine. The measurement of nitrotyrosine provides an indirect estimation of plasma peroxynitrite concentrations. AIMS: To measure plasma nitrotyrosine concentrations to see whether peroxynitrite could contribute to myocardial dysfunction during myocardial ischaemia induced by an exercise tolerance test (ETT). MATERIALS/METHODS: Plasma free nitrotyrosine concentrations were compared before and after exercise in 29 subjects with a positive ETT and 34 subjects with a negative ETT. RESULTS: Plasma nitrotyrosine concentrations were similar in patients with exercise induced myocardial ischaemia and controls. CONCLUSION: Peroxynitrite does not contribute to the myocardial dysfunction in reversible myocardial ischaemia.

Adult↗
PubMed2005

From strange bedfellows to natural allies: the shifting allegiance of fire service organisations in the push for federal fire-safe cigarette legislation.

BACKGROUND: Cigarettes are the leading cause of fatal fires in the USA and are associated with one in four fire deaths. Although the technology needed to make fire-safe cigarettes has been available for many years, progress has been slow on legislative and regulatory fronts to require the tobacco industry to manufacture fire-safe cigarettes. METHOD AND RESULTS: We conducted a case study, drawing on data from tobacco industry documents, archives, and key informant interviews to investigate tobacco industry strategies for thwarting fire-safe cigarette legislation in the US Congress. We apply a theoretical framework that posits that policymaking is the product of three sets of forces: interests, institutions, and ideas, to examine tobacco industry behaviour, with a special focus on their and others' attempts to court fire service organisations, including firefighters' unions as allies. We discuss the implications of our findings for future policy efforts related to fire-safe cigarettes and other tobacco control issues. CONCLUSIONS: Tobacco control advocates ought to: continue efforts to align key interest groups, including the firefighters unions; contest tobacco industry "diversionary" science tactics; and pursue a state based legislative strategy for fire-safe cigarettes, building towards national legislation.

Consumer Product Safety↗
PubMed2004

Female preponderance in congenital adrenal hyperplasia due to CYP21 deficiency in England: implications for neonatal screening.

Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase (CYP21) deficiency causes symptoms ranging from life-threatening neonatal adrenal crises to minimal virilization in adulthood. The relationship between CYP21 genotype and phenotypic markers in a non-screened population of 73 CAH children (44 female, 29 male; 54 white, 19 Asian) treated at the Royal Manchester Children's Hospital was investigated and ethnic and sex differences assessed. The patients were categorized according to the mutation on the mildest allele. The age at the time of diagnosis differed significantly between the groups (p = 0.02): all 25 Null and 25 of 26 of the I2 splice patients were diagnosed during the neonatal period, whereas 7 of 11 I172N patients were diagnosed late. Degree of female genital virilization, 17-hydroxyprogesterone level at diagnosis, and fludrocortisone requirement during the 1st year of treatment correlated with the genotype, although Asian Null patients required more fludrocortisone than their white counterparts (p = 0.055). There was an equal sex ratio in both the I2 splice (12 female/14 male) and I172N (5 female/6 male) groups. However, in the Null group, the ratio was 4.0 (20 female/5 male; p = 0.003), suggesting that some Null male infants perish before being clinically detected to have CYP21 deficiency. Our findings strongly support the need for implementation of a neonatal screening programme for CAH in the UK which may reduce the male infant mortality.

Adrenal Hyperplasia, Congenital↗
PubMed2004

Detailed analysis of the behavior of Lister and Wistar rats in anxiety, object recognition and object location tasks.

The present study, examines some issues in the measure and analysis of behavior in animals. Two strains of rats of both genders were used to illustrate and discuss these issues. We examined to what extent various behavioral measures reflect different or identical emotional or cognitive factors and, how sensitive are the various parameters of a task to differences between strains and genders. Wistar and Lister males and females rats were tested in an anxiety test then in the object recognition task followed by the object location task. Taking advantage of a simple computer program it is possible to: (1) record several parameters of theses tasks and examine the pattern of animal responses toward novelty and/or familiarity; (2) examine whether different measurements of the same response would reflect anxiety response to novelty and, can they discriminate between novelty and familiarity responses to objects; and (3) examine if changes in the pattern of animal responses are reflected by these measurements and, whether anxiety or discrimination is evident mainly during the first minute of the test. The results on the anxiety test show that different measures of the same response proved concordant and revealed significant differences between Lister males and Wistar males. Lister males approached more frequently an object and spent more time on an object in each approach compared to Wistar males in the first 5 min of test and in the total 10 min. They have also shorter latencies between approaches compared to Wistar males. The examination of performance over different time bins was significant with the measure of frequency. Lister male rats approached less frequently the object in the last 5 min of the test compared to the first 5 min. Their performance, however, did not differ from that of the other groups in this last 5 min. In the memory tasks, the measure of the frequency of approaches suggests that Lister male rats were able to discriminate between novel and familiar objects and, between novel and familiar location of objects. The measure of latency of first approach shows that Wistar female rats were able to discriminate between objects only in the spatial memory test. Discrimination in the object recognition task was observed in the first and second minute, and in the total 3 min sessions. Discrimination in the object location task was observed with the measure of frequency of approaches, in the first minute, and in the total 3 min sessions. Results from the total 3 min sessions were more concordant between the different measures of discrimination than results from separate 1 min bins. The results from the two memory tasks show that novelty prevented habituation to re-exposure to the testing environment. In many cases, novelty increased exploration of the objects in the choice phase compared to the sample phase. However, this lack of habituation or increased exploration in the choice phase is not concordant with most results of discrimination between novelty and familiarity from the same type of measurements.

Analysis of Variance↗