PubMed Health⌕ Search

Biomedical subjects

A A Siddiqui

Publications and source records attributed to A A Siddiqui.

At least 19 recordsLinked to original sources
PubMed2006

Endoscopic sphincterotomy with or without cholecystectomy for choledocholithiasis in high-risk surgical patients: a decision analysis.

BACKGROUND: Laparoscopic cholecystectomy (LC) is recommended for patients with choledocholithiasis after ERCP with sphincterotomy (ES) and stone extraction. AIM: We designed a decision model to address whether ES alone versus ES followed by LC (ES + LC) is the optimal treatment in high-risk patients with choledocholithiasis. METHODS: Our cohort were patients with obstructive jaundice who have undergone an ES with biliary clearance. Recurrent biliary complications over a 2-year period stratified by gallbladder status (in/out) and age-stratified surgical complication rates were obtained from the literature. Failure of therapy was defined as either recurrent symptoms or death attributed to biliary complications. RESULTS: For age 70-79 years, ES failed in 15% whereas ES + LC failed in 17% of cases. Mortality in the EC + LC group was 3.4 times that of the ES alone cohort. For age 80+ years, ES was dominant with an incremental success rate of 8%. Mortality in the ES + LC was 7.6 times that of ES. For age <70, ES + LC was the dominant strategy with an incremental success rate 5%. Sensitivity analysis in the groups confirmed our conclusions. CONCLUSIONS: Management of choledocholithiasis by ES and stone clearance, but without cholecystectomy, should be considered for patients aged 70+. For low-risk patients, ES + LC should be performed to prevent recurrent biliary complications.

Aged↗
PubMed2006

Enhanced detection rate of typhoid fever in children in a periurban slum in Karachi, Pakistan using polymerase chain reaction technology.

OBJECTIVE: Yield of blood culture in clinically suspected cases of typhoid fever is low, whereas indirect serological diagnostic tests are unreliable. Hence, polymerase chain reaction (PCR)-based detection of Salmonella enterica Serovar typhi was used as an aid for diagnosis of typhoid fever in addition to other diagnostic tests. Two periurban communities in Karachi were selected for an epidemiological study of typhoid fever. The aim of the study was to assess whether PCR increased the detection rate of typhoid fever in children in the community. MATERIAL AND METHODS: Children aged 2 to 14 years presenting with fever lasting for three or more days were selected. PCR using Hashimoto's protocol based on ViaB gene sequence was used in addition to blood culture and other serological tests. RESULTS: Of the 214 children included in the study, blood culture was found positive for S. enterica S. typhi in 26 (12.4%) cases, whereas 24 children (11.7%) were diagnosed as suffering from typhoid fever when the PCR-based method was used. Both tests were positive in only 10 (4.9%) children. The number of children found positive for either test was 40. PCR increased the rate of detection of typhoid fever by 51%. CONCLUSION: The sensitivity, specificity, +ve and -ve predictive values of PCR in this study were 40%, 93%, 45% and 92%, respectively.

Adolescent↗
PubMed2006

Determinants of compliance with colonoscopy in patients with adenomatous colon polyps in a veteran population.

AIM: To determine factors affecting compliance of a follow-up colonoscopy in patients with previously diagnosed adenomatous colon polyps. METHODS: A retrospective review was performed on patients with adenomatous polyps excised between January and December 1998. Twenty-nine clinical factors were assessed in patients grouped into whether they were compliant (n = 81) or noncompliant (n = 38) with follow-up colonoscopy. Significant variables by univariate analysis were included in multivariate regression. RESULTS: One hundred and nineteen patients with adenomatous colon polyps were identified. Of 119 patients, 114 had a documented recommendation for follow-up of 5 years or less, with 69% having been compliant. In a univariate analysis, greater number of polyps (P = 0.04), NSAID use (P = 0.02), statin use (P = 0.005), first-degree relatives with colon cancer (P = 0.05) and compliance with out-patient clinic follow-up (P < 0.001) were significantly associated with patient compliance. Multivariate analysis revealed statin use (P = 0.05), first-degree relatives with colon cancer (P = 0.06) and compliance with out-patient clinic follow-up (P < 0.001) were independent predictors of compliance. CONCLUSIONS: History of statin use and family history of colon cancer are good predictors of compliance. The strongest predictor can be anticipated with compliance assessed with encounters for other visits. Strong efforts should be directed at improving patient education about colon cancer by the physician and facilitating patient compliance.

Adenomatous Polyps↗
PubMed2006

Correlation between translation efficiency and outcome of combination therapy in chronic hepatitis C genotype 3.

Combination therapy with interferon-alpha (IFN-alpha) and ribavirin (RBV) in chronic hepatitis C demonstrates the best responses against hepatitis C virus (HCV) of genotype 3. Still, it has proven to be ineffective in 20-30% of patients infected with this genotype. In the present study, we analysed the translation efficiency mediated by the internal ribosome entry site (IRES) region in HCV genotype 3 genomes isolated from sustained responders (SR) and non-responders (NR), assuming that this may influence the outcome of treatment. Pretreatment isolates of genotype 3 from 22 individuals (15 SR, seven NR) were selected for such analyses. The IRES region [nucleotide (nt) 1-407] was cloned into a dual luciferase vector and IRES activity assessed following transfection into various cell lines. Low relative translation efficiency was observed for IRES elements derived from SR patients, whereas those of NR patients showed significantly greater translation efficiency (29.7 +/- 13 vs 69.4 +/- 22; P < 0.01). Subsequently, the effect of IFN-alpha plus RBV on IRES-driven translation in vitro was determined. A greater suppressive effect was observed on IRES activity isolated from seven SR patients, when compared with seven NR patients. In conclusion, IRES efficiency in vitro correlated with treatment response for HCV genotype 3. Further studies are warranted to investigate whether IRES efficiency in vitro, or sequence motifs associated with IRES efficiency, will be worthwhile to explore as prognostic tools for other HCV genotypes in the treatment of chronic HCV infection.

Adult↗
PubMed2006

Measurement and significance of 3-nitrotyrosine in systemic lupus erythematosus.

Nitration of free and protein associated tyrosine represents, in vivo, a mechanism that can severely compromise the cell function. The detection of 3-nitrotyrosine (3-NT) in pathological tissues is suggestive of the occurrence of nitrating pathways and has been identified as a marker of inflammation and a stable end product of increased reactive nitrogen intermediate production. Protein nitration occurs in many disease conditions including systemic lupus erythematosus (SLE). In this study we show that the level of both free and protein bound 3-NT, which is produced by reactive nitrogen species (RNS)-dependent oxidative damage, is elevated in patients with SLE and that there is a possible role of RNS-modified epitopes in the aetiology of the disease. Commercially available poly L-tyrosine was exposed to nitrating species, inducing nitration in tyrosine residues. Immunoglobulin-G (IgG) purified on Protein-A-Sepharose matrix from 24 SLE patients was studied for their recognition of native and nitrated poly L-tyrosine by direct binding and competition enzyme-linked immunosorbent assay (ELISA). The formation of immune complex between SLE IgG and nitrated poly L-tyrosine was visualized by gel retardation assay. Free 3-NT in patients' sera was detected and quantitated by high performance liquid chromatography whereas protein-bound 3-NT was analysed by Western blotting and the concentration was calculated by sandwich ELISA. The concentration of free 3-NT was found to be 1.4 +/- 0.09 microm whereas the concentration of protein bound 3-NT was 96.52 +/- 21.12 microm nitrated bovine serum albumin equivalents/mg protein, which was significantly higher when compared with healthy controls. Elevated level of 3-NT was observed in SLE patients using two different techniques, when compared with healthy subjects confirms the overproduction of RNS in the pathogenesis of human SLE.

Adolescent↗
PubMed2005

Diagnostic MR imaging features of craniocerebral Aspergillosis of sino-nasal origin in immunocompetent patients.

BACKGROUND: Craniocerebral invasive Aspergillosis of sino-nasal origin has been reported with a very high mortality due to a peculiarly fulminant clinical course. Early diagnosis based on clinical radiological imaging may have an impact on final clinical outcome. This retrospective study focuses on characteristic MR imaging features of Aspergillosis (of sinonasal origin) in immunocompetent patients. METHODS: Medical records of patients were reviewed retrospectively during the period from 1991 to 2003 in the two tertiary care hospitals. All the patients had radiological evidence of disease in the paranasal sinuses with or without intracranial extension. Immunocompetence of patients was assessed on clinical and radiological data. MRI scans (n=20) were reviewed by both clinical neurosurgeons and neuroradiologists separately. MRI was done on 1.5 tesla scanners and both T2-weighted and T1 weighted sequences were obtained followed gadolinium enhanced images. Patients were categorized into three types based on their anatomical location on MRI scans; type-1 being intracerebral, type-2 as intracranial extradural and type-3 invading orbit and/or skull base only. All these patient had the epicenter of disease in the nose and/or paranasal sinuses as evident on MR imaging. All patients underwent standard surgical intervention followed by antifungal therapy. Clinical outcome was assessed on Glasgow outcome scale with mean duration of clinical follow up of 13.9 months. FINDINGS: Mean age of patents (n=20) was 31.1 years with male preponderance (3:1). MRI scans showed evidence of disease in paranasal sinuses including mucosal thickening (n=11) and complete filling of sinuses (n=9). T2-weighted images showed extremely hypo-intense fungal mass (n=19) while T1-weighted images had iso-intense signals (n=18). Gadolinium-enhanced images showed bright homogenous contrast enhancement (n=18) and peripheral ring enhancement pattern (n=2). All patients underwent appropriated surgical procedures depending upon anatomical location followed by standard antifungal therapy. Tissue diagnoses were established by histopathology (n=20) and culture growth (n=5). Overall mortality remained 15 percent. INTERPRETATION: Craniocerebral Aspergillosis of sinonasal origin has typical MR imaging features. These features include a mass lesion producing hypo-to-iso-intense signals on T1-weighted, extremely low signals (hypo-intense) on T2-weighted images, with bright homogenous enhancement on post-gadolinium T1-weighted imaging. These features in the clinical background may be helpful in early diagnosis and management of Aspergillosis of sino-nasal origin in immunocompetent hosts. Prospective clinical study is required to make firm clinical therapeutic recommendations.

Adolescent↗
PubMed2005

Experimental analysis of screw hold as judged by operators v pullout strength.

An analysis of the accuracy of the operators' assessments of the hold of bone screws is reported. These assessments of screw hold were compared with measurements from pullout testing. Four operators, encompassing a range of experiences in terms of screw insertion, prepared the pilot holes, and inserted a number of screws, assigning each with a score from 0 to 10 on the basis of how good the hold was felt to be. The pullout strength for each screw was then measured using a tensometer. The results were analysed and correlation coefficients calculated. Significant correlation was observed in all four subjects, with P < 0.001 in two out of the four subjects, and 0.01 > P > 0.001 in the other two. The conclusions were that there is a strong correlation between the subjective assessment of screw hold and actual pullout strength within the four subjects analysed.

Bone Screws↗
PubMed2005

Characterization of protective immunity induced against Schistosoma mansoni via DNA priming with the large subunit of calpain (Sm-p80) in the presence of genetic adjuvants.

Despite advances in control via snail eradication and large-scale chemotherapy using praziquental, schistosomiasis continues to spread to new geographic areas particularly in sub-Saharan Africa. Presently, there is no vaccine for controlling this disease. We have concentrated on a functionally important schistosome antigen Sm-p80 as a possible vaccine candidate for schistosomiasis. Here we report the proliferation of spleen cells in response to the recombinant Sm-p80 protein and cytokine (IFN-gamma and IL-4) production by the splenocytes. These spleen cells were obtained from groups of mice that were vaccinated with a DNA vaccine formulation containing Sm-p80 and one of the Th-1 (IL-2 or IL-12) or Th-2 (GM-CSF, IL-4) enhancer cytokines. The splenocytes from the groups of mice vaccinated with Sm-p80 DNA in the presence of Th-2 enhancer cytokines showed moderate but detectable proliferation. The splenocytes obtained from mice vaccinated with Sm-p80 DNA with Th-1 enhancer cytokines IL-2 and IL-12 provided the highest proliferation. The IFN-gamma production by splenocytes was found to follow the similar pattern [(Sm-p80) < (Sm-p80 + IL-4) < (Sm-p80 + GMCSF) < (Sm-p80 + IL-12) < (Sm-p80 + IL-2)], as has been observed for the proliferation and protection data. However, the elevated IL-4 production was inversely correlated to Sm-p80-induced splenocyte proliferation or the protection. These results show again that protective immune response induced by Sm-p80 is of Th-1 type.

Adjuvants, Immunologic↗
PubMed2004

Complete surgical excision of intramedullary schwannoma at the craniovertebral junction in neurofibromatosis type-2.

Intramedullary spinal schwannomas are extremely rare. We describe a case of a 13-year-old female who was found to have an intramedullary schwannoma at craniovertebral junction along with incidental bilateral acoustic neuromas, which was excised completely. To our knowledge, this is the first report of a case of intramedullary schwannoma in association with NF-2 located at the craniovertebral junction. The literature has been reviewed with emphasis on radiological imaging, histopathological diagnosis and technique to achieve complete microsurgical excision.

Adolescent↗
PubMed2003

Posterior sternoclavicular joint dislocation: the value of intra-operative ultrasound.

The sternoclavicular joint dislocates posteriorly if the costoclavicular ligaments, posterior capsule, and anterior capsule have all been disrupted. Diagnosis of a posteriorly dislocated sternoclavicular joint is difficult on clinical examination and with plain X-rays. The treatment objective is to obtain a closed reduction, and failing this an open reduction is indicated. In the intra-operative setting the evaluation of the reduction when performed through closed means can be somewhat difficult, and intra-operative plain films do not give clear answers. Ultrasound as an imaging modality for these injuries was shown to demonstrate the state of the joint in terms of reduction, more clearly than X-rays (P<0.001). It was accurately interpreted by the vast majority of orthopaedic surgeons in an investigation, and is of great value in the intra-operative setting to confirm whether a closed reduction has been successful or not. A case is reported illustrating its use.

Adult↗
PubMed2003

Cage versus tricortical graft for cervical interbody fusion. A prospective randomised study.

We conducted a prospective, randomised study of 42 cervical interbody fusions undertaken with either an autologous tricortical graft or a cage. The factors assessed in the two groups were: (1) time taken to achieve fusion; (2) neck disability index; (3) pain score; (4) interbody height ratio; (5) interbody angle and (6) the influence of smoking on fusion. No statistical difference was seen in the time taken to achieve fusion, neck disability index, interbody height ratio, or interbody angles. Smoking did not have any effect on the fusion process. The pain score was significantly lower in the tricortical graft group at six months. We conclude that both methods of fusion give similar results, although tricortical graft fusion is cheaper than cage fusion, and is more effective in reducing the pain score.

Adult↗
PubMed2002

Predictors of mortality in brain abscess.

OBJECTIVE: Brain abscess carries significant morbidity and mortality. Our objective was to elucidate the clinical presentation of brain abscess and to assess predictors of mortality in these patients. METHODS: All patients with a brain abscess presenting to the Aga Khan University Hospital, a tertiary care referral center in Karachi, Pakistan, were studied retrospectively. Statistical analysis involved univariate analysis and a logistic regression model. RESULTS: Among the 66 patients analyzed, a distant metastatic focus of infection was the most commonly identified predisposing factor (29%). Otogenic infection was the commonest contiguous source and sinusitis was noticeably absent. Multiple abscesses were frequent (35%). Streptococci were the most common isolates (39%). Lumbar puncture was performed in 44% and steroids administered in 33%. Treatment was surgical in 58%. Most comatose patients were treated conservatively. Overall mortality was 29%. Univariate analysis identified comatose presentation and identification of a distant focus of infection as predictors of mortality. The logistic regression model, however, identified a distant focus of infection as the only independent predictor. CONCLUSION: Age greater than 30 years, corticosteroid use, multiple abscesses, performance of lumbar puncture and conservative management had no affect on outcome.

Adolescent↗
PubMed2002

Determination of alpha-1 antitrypsin genetic deficiency in duodenal ulcer by polymerase chain reaction.

OBJECTIVE: To confirm alpha-1-AT deficiency status in duodenal ulcer using a combination of PCR and restricted enzyme digestion. METHODS: Fifty patients with endoscopically proven duodenal ulcer and hundred controls with no signs of the disease were included. Alpha-1-AT phenotypes were confirmed by polymerase chain reaction followed by restriction enzyme digestion. RESULTS: Alpha-1-AT concentration in duodenal ulcer patients showed a mean value of 2.12 +/- 0.11 g/l (range: 0.52-3.95 g/l, p < 0.05). In controls this was 2.47 +/- 0.08 g/l (range: 0.52-5.0 g/l). Among the controls 70% had the MM phenotype, 28% M1 M2 and 2% FM. In duodenal ulcer, MM predominates (70%), followed by M1 M2 (18%), SS (4%), SZ (4%), ZZ (2%) and MZ (2%). CONCLUSION: Alpha-1 AT deficiency was found in 10% of duodenal ulcer patients. DNA analysis more accurately resolved the phenotypes as S and Z mutations.

Adult↗
PubMed2001

Diagnosis of Strongyloides stercoralis infection.

Strongyloides stercoralis infects 30 million people in 70 countries. Infection usually results in asymptomatic chronic disease of the gut, which can remain undetected for decades. However, in patients receiving long-term corticosteroid therapy, hyperinfection can occur, resulting in high mortality rates (up to 87%). Strongyloidiasis is difficult to diagnose because the parasite load is low and the larval output is irregular. Results of a single stool examination by use of conventional techniques fail to detect larvae in up to 70% of cases. Several immunodiagnostic assays have been found ineffective in detecting disseminated infections and show extensive cross-reactivity with hookworms, filariae, and schistosomes. Although it is important to detect latent S. stercoralis infections before administering chemotherapy or before the onset of immunosuppression in patients at risk, a specific and sensitive diagnostic test is lacking. This review describes the clinical manifestations of strongyloidiasis, as well as various diagnostic tests and treatment strategies.

Animals↗
PubMed2001

Neoplastic growth of cerebral cavernous malformation presenting with impending cerebral herniation: a case report and review of the literature on de novo growth of cavernomas.

BACKGROUND: Cerebral cavernomas are rare vascular anomalies and their expansile growth has been considered to be mainly due to recurrent hemorrhages. They are not generally reported to show aggressive behavior. CASE DESCRIPTION: A 27-year-old male presented with headache, visual disturbances, and a 17-year history of seizures. He was known to have a temporal lobe lesion on CT scan, consistent with a diagnosis of cavernous malformation but with no relevant family history. Serial clinical and radiological follow-up revealed a progressive increase in the size of the lesion with formation of a growing cyst of 7 cm in diameter, which produced mass effect, resulting in the clinical picture of cerebral herniation. The patient underwent emergency surgical resection with symptomatic relief. There was no evidence of significant hemorrhage at surgery. CONCLUSION: Cavernous malformations can show expansile growth without any evidence of a presaging hemorrhagic event and, in the manner of a neoplastic lesion, present with raised intracranial pressure and cerebral herniation.

Adolescent↗
PubMed2001

Isolation of a cDNA encoding an IgG immunoreactive antigen (zinc finger protein) of Strongyloides stercoralis.

A full length cDNA encoding an IgG immunoreactive antigen of Strongyloides stercoralis is described. A clone containing 1,328 bp insert was selected following screening of S. stercoralis cDNA library with an IgG fraction obtained from a pool of 78 S. stercoralis positive human sera samples. The nucleotide sequence of the 1,328 bp insert was found to be 70.5% A/T, reflecting a characteristic A/T codon bias of S. stercoralis. The nucleotide sequence of this insert identified a cDNA coding for a zinc finger protein. The conceptually translated amino acid sequence of the open reading frame for the IgG immunoreactive antigen of S. stercoralis encodes a 211 amino acid residue protein with an apparent molecular weight of 22.8 kDa and a predicted isoelectric point of 8.71. The diagnostic potential of this IgG immunoreactive antigen of S. stercoralis is also discussed.

Amino Acid Sequence↗
PubMed2001

Immediate loading of dental implants in the edentulous mandible: a preliminary case report from an international prospective multicenter study.

The ability to predictably achieve long-term osseointegration in patients with compromised anatomical resources has been demonstrated numerous times in modern oral implantology. Recently, clinical attention has focused on new methods of reducing treatment time. One-stage surgical procedures and immediate loading of implants at the time of placement are two techniques that have demonstrated promising clinical results. A prospective clinical study of immediately splinting and loading a new, one-stage implant is currently in progress in the United States and France. An overview of the implant design and presentation of one case study from the University of Pittsburgh demonstrates how this promising technique is performed.

Aged↗