PubMed Health⌕ Search

Biomedical subjects

M S Anwar

Publications and source records attributed to M S Anwar.

10 recordsLinked to original sources
PubMed2007

Hypoxia-regulated carbonic anhydrase IX expression is associated with poor survival in patients with invasive breast cancer.

Tumour hypoxia is a microenvironmental factor related to poor response to radiation, chemotherapy, genetic instability, selection for resistance to apoptosis, and increased risk of invasion and metastasis. Hypoxia-regulated carbonic anhydrase IX (CA IX) has been studied in various tumour sites and its expression has been correlated with the clinical outcome. The purpose of this study was to investigate the correlation of CA IX expression with outcome in patients with invasive breast cancer. We conducted a retrospective study examining the effects of carbonic anhydrase IX (CA IX) on survival in patients with breast cancer. To facilitate the screening of multiple tissue blocks from each patient, tissue microarrays were prepared containing between two and five representative samples of tumour per patient. Immunohistochemistry was used to examine expression of CA IX in patients with breast cancer. The study includes a cohort of 144 unselected patients with early invasive breast cancer who underwent surgery, and had CA IX expression and follow-up data available for analysis. At the time of analysis, there were 28 deaths and median follow-up of 48 months with 96% of patients having at least 2 years of follow-up. CA IX was negative for 107 patients (17 deaths) and positive for 37 patients (11 deaths). Kaplan-Meier survival curves show that survival was superior in the CA IX-negative group with a 2-year survival of 97% for negatives and 83% for positives (log-rank test P=0.01). Allowing for potential prognostic variables in a Cox regression analysis, CA IX remained a significant independent predictor of survival (P=0.035). This study showed in both univariate and multivariate analysis that survival is significantly inferior in patients with tumour expressing CA IX. Prospective studies are underway to investigate this correlation in clinical trial setting.

Adult↗
PubMed2005

Generation and interrogation of a pure nuclear spin state by parahydrogen-enhanced NMR spectroscopy: a defined initial state for quantum computation.

We describe a number of studies used to establish that parahydrogen can be used to prepare a two-spin system in a pure state, which is suitable for implementing NMR quantum computation. States are generated by pulsed and continuous-wave (CW) UV laser initiation of a chemical reaction between Ru(CO)(3)(L(2)) [where L(2) = dppe = 1,2-bis(diphenylphosphino)ethane or L(2) = dpae = 1,2-bis(diphenylarsino)ethane] with pure parahydrogen (generated at 18 K). This process forms Ru(CO)(2)(dppe)(H)(2) and Ru(CO)(2)(dpae)(H)(2) on a sub-microsecond time-scale. With the pulsed laser, the spin state of the hydride nuclei in Ru(CO)(2)(dppe)(H)(2) has a purity of 89.8 +/- 2.6% (from 12 measurements). To achieve comparable results by cooling would require a temperature of 6.6 mK, which is unmanageable in the liquid state, or an impractical magnetic field of 0.44 MT at room temperature. In the case of CW initiation, reduced state purities are observed due to natural signal relaxation even when a spin-lock is used to prevent dephasing. When Ru(CO)(3)(dpae) and pulsed laser excitation are utilized, the corresponding dihydride product spin state purity was determined as 106 +/- 4% of the theoretical maximum. In other words, the state prepared using Ru(CO)(3)(dpae) as the precursor is indistinguishable from a pure state.

Bicarbonates↗
PubMed2005

Multicentre prospective audit of surgical outcomes and acute complications following short course pre-operative radiotherapy for resectable rectal cancer.

BACKGROUND: The addition of short course pre-operative radiotherapy to total mesorectal excision reduces local recurrence in resectable adenocarcinoma of the rectum. In a previous retrospective study potential factors associated with early complications following this combination were identified. The aim of this study was to examine these relationships in a prospective multicentre audit. METHODS: One hundred and seven patients who received short course pre-operative radiotherapy in four cancer centres between 1 October 2001 and 30 September 2002 were included. Data including patient age, radiotherapy field length, overall treatment time, operation type, surgical outcomes and complications occurring within 3 months of the 1st day of radiotherapy were collected. These were compared and combined with the previously studied cohort of 176 patients treated at one centre between 1st January 1998 and 31st December 1999. RESULTS: In the prospective cohort only patient age (P=0.001) was significantly associated with acute complications. However, both the overall treatment time (median 9.0 vs 11.0 days P <0.0001) and field length (median 16.6 vs 17.0 cm P=0.03) were significantly shorter in this cohort when compared to the previous retrospective study. In patients from both studies (n=283), increasing age (P=0.002) and field length (independent of operation type) (P=0.02) were independently associated with an increased risk of acute complications. CONCLUSIONS: This study suggests that meticulous selection of patients for short course pre-operative radiotherapy and smaller planning target volumes may be associated with a lower risk of acute complications. The use of MRI scanning to stage pelvic disease may reduce the number of patients with R1 resections receiving short course pre-operative radiotherapy.

Acute Disease↗
PubMed2004

Preparing high purity initial states for nuclear magnetic resonance quantum computing.

Here we demonstrate how parahydrogen can be used to prepare a two-spin system in an almost pure state which is suitable for implementing nuclear magnetic resonance quantum computation. A 12 ns laser pulse is used to initiate a chemical reaction involving pure parahydrogen (the nuclear spin singlet of H2). The product, formed on the micros time scale, contains a hydrogen-derived two-spin system with an effective spin-state purity of 0.916. To achieve a comparable result by direct cooling would require an unmanageable (in the liquid state) temperature of 6.4 mK or an impractical magnetic field of 0.45 MT at room temperature. The resulting spin state has an entanglement of formation of 0.822 and cannot be described by local hidden variable models.

Journal Article↗
PubMed2000

Diagnosis of Clostridium difficile antibiotic associated diarrhoea culture versus toxin assay.

OBJECTIVE: To compare the results of Clostridium Difficile (CD) on culture with detection of C. difficile toxin by Enzyme Immunoassay (EIA) in the stool specimens of hospitalized patients with antibiotic associated diarrhoea (AAD). PATIENTS AND METHODS: The study included 80 adult patients with AAD and 20 adult patients with non-AAD. Stool specimens of all these subjects were inoculated on cycloserine cefoxitin fructose agar and incubated anaerobically to isolate C. difficile. At the same time, all the stool specimens were tested for C. difficile toxin by EIA technique using cytoclone A and B kit manufactured by Cambridge Biotech Corporation, Worcester, Massachusette. RESULTS: Out of 80 adult patients with AAD, thirty were females and fifty males. C. difficile was isolated on culture from stool specimen of 16 patients, while twenty-three stool specimens were positive for C. difficile toxin. From 20 control subjects, C. difficile was isolated from stool specimen of only one subject. No stool specimen from the controls was positive for toxin. CONCLUSION: Diagnosis of CDAAD by culture is difficult and time consuming because of strict anaerobic nature of organism. Moreover, mere isolation of C. difficile on culture is not sufficient to establish the pathogenic role of these isolates. C. difficile toxin detection by EIA technique is a highly sensitive and specific method for diagnosis of CDAAD. Using this method, results are available in three hours time. Therefore, EIA is recommended for rapid diagnosis of CDAAD.

Adolescent↗
PubMed1999

Bacteriological quality of drinking water in Punjab: evaluation of H2S strip test.

OBJECTIVE: To assess bacteriological quality of drinking water in Punjab and to evaluate usefulness of H2S strip test in comparison with multiple tube test. METHOD: Samples of water were tested using H2S strips and multiple tube test. RESULTS: Maximum bacterial contamination was observed in water from domestic pumps (95.83%). Followed by tap water in rural areas of Punjab (91.30%) and tap water in Lahore (42.85%). Bacterial contamination was significantly higher (p < 0.001) in rural areas as compared to urban areas. Comparison of results of testing water samples by H2S strip test and multiple tube test revealed that H2S strip is 87.24% sensitive and 100% specific for detection of bacterial contamination with a positive predictive value of 100%. It was also observed that 100% water samples negative for total coliforms were also negative by H2S strip method. Moreover, with increase in number of total coliforms in the water samples, positivity by H2S strip method also increased (samples with more than 10 total coliforms/100 ml were 100% positive by H2S strip method). Therefore, H2S strip test can be used as alternative to multiple tube test for detection of bacterial contamination of water supplies. CONCLUSION: It is concluded that bacterial contamination of water is a significant problem in Punjab. It can be improved by regular monitoring of water supplies. For this purpose use of H2S strip test is advocated at house hold level.

Enterobacteriaceae↗
PubMed1996

Evaluation of dipstrips, direct gram stain and pyuria as screening tests for the detection of bacteriuria.

Two hundred and fifty cases of clinically suspected urinary tract infection were analysed for the detection of bacteriuria. Parameters studied included direct Gram staining, pyuria on microscopic examination of uncentrifuged urine and dip strip method for the detection of blood, protein, nitrite and leucocyte esterase. Significant bacteriuria (colony count 10(5) per ml) was found in 112 cases with a positivity ranging from 65 to 83% for the presence of blood, protein, nitrite and leucocyte esterase. Highest positive predictive values were obtained with the presence of nitrite and leucocyte esterase (98%), blood, protein and nitrite (94%) as well as with blood, protein, nitrite and leucocyte esterase (98%). Both pyuria and direct Gram staining were positive in 85% cases. The combined presence of both these parameters gave 100% positive predictive value. Gram staining combined with pyuria was more effective and economical as compared to the dipstrips for the detection of bacteriuria.

Bacteriological Techniques↗
PubMed1995

Clinical features of infantile diarrhea associated with single or multiple enteric pathogens.

Clinical features of infantile diarrhea were studied among 603 infants from birth to 12 months of age to determine the predominant clinical feature(s) seen in infantile diarrhea associated with a specific enteric pathogen. Among the major clinical features, fever was most often seen in diarrhea due to Yersinia spp. (61.5%) followed by that in rotavirus (26.1%). Vomiting was mostly associated with Vibrio cholerae infection (90.9%) and shigellosis (64.6%). Dehydration was predominant in Vibrio cholerae (90.9%) and Salmonella (84.9%) infections. Bloody diarrhea was mostly due to Shigella infection (74.3%). As regards diarrhea with multiple pathogens, vomiting and dehydration were most frequent with Campylobacter+Enteropathogenic Escherichia coli (EPEC) (88.9% and 77.8%, respectively), while fever was more common with rotavirus+Shigella+Escherichia coli and rotavirus+Giardia. Infection with invasive organisms lead to vomiting, 4-10 stools per day and dehydration significantly more often as compared to infections with non-invasive organisms. Similarly more stools of patients infected with invasive organisms showed presence of blood and more than 5 leukocytes/HPF as compared to those infected with non-invasive organisms.

Campylobacter Infections↗