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Biomedical subjects

S H Hasan

Publications and source records attributed to S H Hasan.

At least 19 recordsLinked to original sources
PubMed2006

Sorption of cadmium and zinc from aqueous solutions by water hyacinth (Eichchornia crassipes).

The water hyacinth (Eichchornia crassipes) has been successfully utilized for the removal of Zn(II) and Cd(II) as well as their admixture from samples of aqueous solutions. The growth of the plant after 16 days of exposure to the metal ions showed an increasing trend up to 2.5 ppm of Cd(II) and 6.0 ppm of Zn(II) concentrations, however, the growth became nondetectable or inhibited above these concentrations. The overall metal uptake by the plant was dependent upon the concentration of the metal and the duration of the exposure time. The metal uptake from a mixture of Cd(II) and Zn(II) was reflected by a rate constant quite different from those solutions containing only one metal ion. An analysis of metal in roots and tops of the plants showed that more Zn(II) was accumulated in the root when compared to Cd(II). However, the accumulation factor for the tops and the roots for Cd(II) and Zn(II) was higher than those obtained admixture of Zn(II) and Cd(II). The rate of metal mobility in the root was slower than that in the top of the plant for Zn(II) and Cd(II). A water hyacinth based system can be used to remove Cd(II) and Zn(II) from water/wastewater.

Adsorption↗
PubMed2005

Removal of lead from aqueous solutions by agricultural waste maize bran.

Maize bran is a low cost biosorbent that has been used for the removal of lead(II) from an aqueous solution. The effects of various parameters such as contact time, adsorbate concentration, pH of the medium and temperature were examined. Optimum removal at 20 degrees C was found to be 98.4% at pH 6.5, with an initial Pb(II) concentration of 100 mg l(-1). Dynamics of the sorption process and mass transfer of Pb(II) to maize bran were investigated and the values of rate constant of adsorption, rate constant of intraparticle diffusion and the mass transfer coefficients were calculated. Different thermodynamic parameters viz., changes in standard free energy, enthalpy and entropy were evaluated and it was found that the reaction was spontaneous and exothermic in nature. The adsorption data fitted the Langmuir isotherm. A generalized empirical model was proposed for the kinetics at different initial concentrations. The data were subjected to multiple regression analysis and a model was developed to predict the removal of Pb(II) from an aqueous solution.

Adsorption↗
PubMed2005

Removal of Cr(VI) from wastewater using rice bran.

The novel biosorbent rice bran has been successfully utilized for the removal of Cr(VI) from wastewater. The maximum removal of Cr(VI) was found to be 99.4% at pH 2.0, initial Cr(VI) concentration of 200 mg l(-1), and temperature 20 degrees C. The effect of different parameters such as contact time, adsorbate concentration, pH of the medium, and temperature was investigated. The adsorption kinetics was tested for first-order reversible, pseudo-first-order, and pseudo-second-order; reaction and the rate constants of kinetic models were calculated. Mass transfer of Cr(VI) from the bulk to the solid phase (rice bran) was studied at different temperatures. Different thermodynamic parameters, viz., changes in standard free energy, enthalpy, and entropy, have also been evaluated and it has been found that the reaction was spontaneous and endothermic in nature. The Langmuir and Freundlich equations for describing adsorption equilibrium were applied to data. The constants and correlation coefficients of these isotherm models were calculated and compared. Desorption studies was also carried out and found that complete desorption of Cr(VI) took place at pH of 9.5. The data were also subjected to multiple regression analysis and a model was developed to predict the removal of Cr(VI) from wastewater.

Adsorption↗
PubMed2005

Low cost bio-sorbent 'wheat bran' for the removal of cadmium from wastewater: kinetic and equilibrium studies.

Novel bio-sorbent wheat bran has been successfully utilized for the removal of cadmium(II) from wastewater. The maximum removal of cadmium(II) was found to be 87.15% at pH 8.6, initial Cd(II) concentration of 12.5 mg l-1 and temperature of 20 degrees C. The effect of different parameters such as contact time, adsorbate concentration, pH of the medium and temperature were investigated. Dynamics of the sorption process were studied and the values of rate constant of adsorption, rate constant of intraparticle diffusion and mass transfer coefficient were calculated. Different thermodynamic parameters viz., changes in standard free energy, enthalpy and entropy have also been evaluated and it has been found that the reaction was spontaneous and exothermic in nature. The applicability of Langmuir isotherm showed of monolayer coverage of the adsorbate on the surface of adsorbent. A generalized empirical model was proposed for the kinetics at different initial concentrations.

Adsorption↗
PubMed2005

Removal of cadmium from wastewater using agricultural waste 'rice polish'.

A novel biosorbent rice polish has been successfully utilized for the removal of cadmium(II) from wastewater. The maximum removal of cadmium(II) was found to be 9.72 mg g(-1) at pH 8.6, initial Cd(II) concentration of 125 mg l(-1) and temperature of 20 degrees C. The effect of different parameters such as contact time, adsorbate concentration, pH of the medium and temperature were investigated. Dynamics of the sorption process were studied and the values of rate constant of adsorption, rate constant of intraparticle diffusion and mass transfer coefficient were calculated. Different thermodynamic parameters, viz., changes in standard free energy, enthalpy and entropy have also been evaluated and it has been found that the reaction was spontaneous and exothermic in nature. The applicability of Langmuir isotherm showed monolayer coverage of the adsorbate on the surface of adsorbents. A generalised empirical model was proposed for the kinetics at different initial concentrations. The data were subjected to multiple regression analysis and a model was developed to predict the removal of Cd(II) from wastewater.

Adsorption↗
PubMed2004

Diagnostic surgical pathology: the importance of second opinion in a developing country.

OBJECTIVE: To review the cases sent to the section of histopathology, Aga Khan Universty (AKU) for second opinion and see whether there are significant differences in the original outside diagnosis and the subsequent diagnosis submitted by us. METHODS: A retrospective study of all consecutive cases for second opinion in the form of paraffin blocks from 1st Novemver 2001 to 31st July 2002. The primary submitted diagnosis in each case was compared with the subsequent AKU diagnosis. RESULTS: The study included a total of 381 cases. However, in 45 cases (11.81%), initial histopathological diagnosis was not provided. Out of the remaining 336 cases, there were differences between the original diagnosis and the subsequent AKU diagnosis in 120 cases (35.71%). Out of these 120 cases, immunohistochemistry was performed in 65 cases (54.16%) only. CONCLUSION: In a developing country like Pakistan, where few laboratories are equipped to function as modern histopathology units, second opinion on difficult cases is very important. Worldwide, the concept of second opinion in surgical pathology is well established.

Bone and Bones↗
PubMed2004

Cancer esophagus Karachi 1995-2002: epidemiology, risk factors and trends.

OBJECTIVE: To study the trends of cancer esophagus in Karachi South during 1995-2002 and identify risk factors. METHODS: Incident esophageal cancer cases recorded at the Karachi Cancer Registry for Karachi South, during 1st January 1995 to 31st December 2003 were reviewed. For maximum completion of data, incident cases registered from 1st January 1995 to 31st December 2002 were included for final analyses. RESULTS: The Age Standardized Incidence Rates (ASIRs) of cancer esophagus in Karachi South for males were 6.5/100,000 (1995-1997) and 6.4/100,000 (1998-2002). In females the observed rates were 7.0/100,000 (1995-1997) and 8.6/100,000 (1998-2002). CONCLUSION: In the moderately high incidence, cancer esophagus zone of Karachi, the ASIRs in males remained stable during the last decade, but in females, an upward trend was observed suggesting a progressively higher exposure to risk factors in the latter. The potential risk factors in Karachi are use of all forms of tobacco, areca nut, infrequent consumption of raw fruits and vegetables and diet deficiencies. There is a necessity to actively control the proven risk factors and address the existence of other risk factors. The primary recommended strategy for the control of cancer esophagus would therefore be legislation against tobacco and areca nut in Pakistan and public health education. The risk factors of cancer esophagus identified in this article need to be further confirmed.

Adult↗
PubMed2004

Orbital embryonal rhabdomyosarcoma in Karachi (1998-2002).

OBJECTIVE: To study the epidemiology of ocular Rhabdomyosarcoma (ORMS) in Karachi. METHODS: Incident ORMS cases resident of Karachi, registered at Karachi Cancer Registry (KCR) during 1st January 1998 to 31st December 2002 were included in the study. The data were classified using ICD-O2; computerized with Canreg-3, and analyzed using SPSS 10.0. RESULTS: Ten cases of ORMS were reported to KCR during 1998-2002. RMS originated in the orbit in eight cases, conjunctiva in one and eyelid in one. Nine cases presented with proptosis, associated with conjunctivitis in four cases. One case presented with eyelid swelling. The crude annual incidence rate was 0.13/100,000, the age standardized rate was 0.3/100,000. The mean age of childhood cases was 10.4 years (95% CI 4.0; 16.7); and adult cases was 24.8 years (95% CI 12.8; 36.7). At presentation, eight patients were older than 10 years and three were older than 20 years. Five cases were categorized as childhood malignancies. Tumors were a TNM stage III disease at presentation in eight cases; survival at the end of one year was 70%, and at the end of two years 20%. There were no survivors at the end of three years. CONCLUSION: ORMS in Karachi is a disease with a dismal survival. It may reflect a late presentation, or shorter adult ORMS survival or a manifestation of a different genetic pattern, associated with rapid evolution and poor prognosis. Health education for the population, especially parents and health providers is essential for early ORMS diagnosis. Pediatricians, ophthalmologists and health professionals, can play a vital role. Healthcare planning should focus on capacity building for ophthalmologic screening. Cytogenetic studies are advised to determine the genetic pattern.

Adult↗
PubMed2003

Breast diseases: a histopathological analysis of 3279 cases at a tertiary care center in Pakistan.

OBJECTIVE: To know the frequency of breast diseases in Pakistani females. METHODS: A retrospective analysis of 3279 breast specimens received over a period of 4 years (1993-1996) at the department of pathology, the Aga Khan University Hospital. RESULTS: Out of a total of 3279 breast specimens, common breast lesions included infiltrating duct carcinoma 37%, followed by fibro adenoma 16.95%, fibrocystic change 13.96%, mastitis 6.83% and duct ectasia 5.33%. Majority of the cases of infiltrating duct carcinoma were encountered in the 5th and 6th decades of life. Tumour size was 2 or >2 cms. in 93% of cases and 40% of them showed 3 or >3 positive lymph nodes. Grade I tumours were 11.38%, grade II 59.17% and grade III tumours 29.47%. Correlation of grade with lymph node metastases (3 or >3+ve nodes) showed 15 cases (1.53%) of grade I, 178 cases (18.25%) of grade II and 68 (6.97%) cases of grade III tumours. CONCLUSION: This study shows that in Pakistani females, the most commonly encountered lesion in carcinoma of the breast followed by the benign lesions such as fibro adenoma, fibrocystic disease & others. Breast carcinoma occurs at a younger age group with predominance of high-grade lesions and with frequent lymph node metastasis.

Adult↗
PubMed2003

Spectrum of cutaneous appendage tumors at Aga Khan University Hospital.

OBJECTIVE: To determine the frequency of various types of cutaneous appendage tumors in our practice. METHOD: This is a partly retrospective and partly prospective study conducted at the Department of Pathology, Histopathology Section, The Aga Khan University Hospital, Karachi between 1st January 1997 and 31st December 2001. RESULTS: One hundred sixty six skin appendage tumors were diagnosed during the study period. 87.3% were benign, while 12.6% were malignant. Male female ratio was almost equal. Mean age was 41.72 years. 37.34% showed eccrine differentiation, 14.45% showed apocrine differentiation and 41.56% showed pilosebaceous differentiation, 6.62% exhibited mixed differentiation. The 5 commonest tumors were pilomatricoma, nodular hidradenoma (eccrine acrospiroma), syringocystadenoma papilleferum, eccrine poroma and eccrine spiradenoma. The commonest malignant tumors were porocarcinoma and sebaceous carcinoma. Pilomatricoma were common in children. CONCLUSION: Most of our findings roughly correlate with the western published data. However, commonest site for eccrine poromas in our study was head and neck. Also, not a single case of eccrine spiradenoma was seen in the first two decades of life. These findings differ significantly from western data.

Adolescent↗
PubMed2002

Early surgical results with intent to treat by radical retropubic prostatectomy for clinically localized prostate cancer.

AIMS: To evaluate the early cancer control rates, morbidity and mortality in men undergoing radical retropubic prostatectomy (RRP) for clinically localized adenocarcinoma prostate. METHODS: Patient's characteristics, operative data, progressive-free survival rates, morbidity and mortality were analyzed for 23 men with clinical T1-2 prostate cancer who underwent surgery with an intent to treat by RRP between December 1997 to July 2001. RESULTS: Patient's mean age was 63 +/- 6.2 years (range 51 to 76 years) with American Society of Anesthesiology (ASA) status I in 4%, II in 65% and III in 31%. Two third of the patients had lower urinary tract obstructive symptoms, followed by hematuria (9%) and back pain (4%). Clinical stages were T1b in 4%, T1c in 9%, T2a in 17%, T2b in 22% and T2c in 48% of the patients. Mean pre-operative serum prostate specific antigen (PSA) was 25 +/- 29 ng/ml (1.1 to 99.3). Bilateral pelvic lymphnode disection(PLND) and RRP was performed in 20 cases (nerve-sparing RRP 5 cases). In 3 cases with gross lymph node metastasis at frozen section, only bilateral orchidectomy was done. The mean operative time was 270 +/- 65 minutes and mean blood loss was 1097 +/- 654 mls. Packed cell transfusions were nil in 26%, 1-2 units in 44%, 3-4 units in 26% and 5 units in 4% of the patients who underwent RRP. The mean length of hospital stay was 10.2 +/- 1 days. Out of 20 patients who underwent RRP, 65% of tumors were confined to the specimen, 20% had seminal vesicle invasion and 15% had nodal metastasis. There was no peri-operative mortality while 2 patients developed epididymo-orchitis and 1 had myocardial ischemia (without infarction). Overall 87% of the patients were fully continent and 13% had mild to moderate stress urinary incontinence. The mean time of return of continence was 11.5 +/- 11.6 weeks. Two of the 3 patients (66%) with follow up information and having undergone nerve-sparing RRP are potent. At a mean follow up of 19.4 +/- 13 months (range 3-45 months), 20 of 23 total patients (87%) and 17 of 20 RRP patients (85%) remained free of disease recurrence with PSA < or = 0.4 ng/ml. CONCLUSION: Our early results confirm the excellent potential for cancer control and low morbidity of radical prostatectomy for men with localized prostate cancer. These results are in conformity with the vast Western experience. Long-term results will be provided.

Adenocarcinoma↗
PubMed2002

Cancer patterns in Karachi division (1998-1999).

OBJECTIVE: A minimal cancer incidence data for Karachi, the largest city of Pakistan, is being presented here, for the years 1998-1999. The city has a population of 9,802,134; males 5,261,712 (52.6%) and females 4,540,422 (47.4%); census 1998. METHODOLOGY: A predominantly mixed (passive and active) registration system has evolved in Karachi, the data sources being the hospitals within the Karachi Division. The reported/retrieved cancer data sets at the Karachi Cancer Registry are checked, coded, computerised in an analytical format and analysed. RESULTS: The incident cancer cases registered in Karachi, during the 2-year period, 1st January 1998 to 31st December 1999 were analysed. The age-standardised incidence rate (ASR) of cancer, all sites was 132.4/100,000 for the males. Cancer of the lung 10.8%; ASR 17.3 was the most frequently recorded malignancy, followed by oral cavity 10.5%; ASR 13.2 and larynx 5.0%; ASR 7.4. The age-standardised incidence rate (ASR) of cancer, all sites was 133.0/100,000 in the females. Cancer of the breast, 32.0%; ASR 40.7 was the most frequently recorded malignancy, followed by oral cavity 8.1%; ASR 11.7 and gall bladder 3.6%; ASR 5.5. CONCLUSION: The present data has been calculated with an estimated 15-20% probable under ascertainment. Tobacco-associated cancers in Karachi were responsible for 38.3% of the tumours diagnosed amongst the males. Two principal cancers, breast and oral cavity were responsible for 40.1% of the cancers in females. A rare finding was the high incidence of gall bladder cancer in the females. At present it is difficult to determine whether this indicates a genuine high risk or a selection bias. A continuous process of cancer registration to study the trends in the incidence and an adequate cancer control program are possible and essential for Pakistan and can be based on the pattern being practiced in Karachi.

Breast Neoplasms↗
PubMed2002

Comparability and Quality Control in Cancer Registration; Karachi (data monitoring 1995-2001).

INTRODUCTION: Comparability and Quality Control in Cancer Registration remains an essential component of standardisation of cancer incidence data. The information provided by registries is used as a base-line data for cancer control and cancer research. As such misleading information will encourage fictious cancer patterns with over or under registration of some cancer sites. METHODOLOGY: The registration in Karachi started in 1995 and was confined to a single district of Karachi, the South District. Since 1998 the registration has extended to Karachi Division. For both the data sets, recommendations of the International Agency for Research on Cancer (IARC) and the International Association of Cancer Registries (IACR) have been followed to assure comparability and Quality Control of the results. RESULTS: The 2 data sets from Karachi show well-recorded demographic details of cases. Age was not a true indicator of validity in our case, as we have approximate ages of patients aggregated around quintiles and decades. All the cancer cases were reported from a minimum of 3 sources. Microscopic verifications (MV) were high. Cancers with the highest histological verification (HV) were those located in easily accessible sites e.g. breast, oral cavity and cervix. The age specific incidence rates (ASR) for Karachi South, all sites (1995-1999) was 148.1 males and 175.5 females. The same for Karachi Division (1998-99) was 132.4 males and 133.0 females. CONCLUSION: The cancer data in 1995 during the initial phase of registration was incomplete and suffered from inaccuracies associated with a lack of awareness in early years of registration. By the year 2001, the data (1995-1999) showed improved completion and accuracy. The incidence rates have shown no dramatic changes during the past 2 years. The malignancies also show a stable pattern, despite the possibility of under-registration of clinically diagnosed cases. The microscopic verification is high compared with the world region and similar to those observed in developed countries. This may be due to the widely available diagnostic facilities in Karachi and should therefore be considered an indicator of validity of registered data.

Adolescent↗
PubMed2002

Transitional cell carcinomas of the urinary bladder. A histopathological study.

OBJECTIVE: To determine the histological grading and muscle invasion in Transitional Cell Carcinomas of the Urinary Bladder; and to evaluate whether any correlation exists between tumour grade and muscle invasion. METHOD: A Retrospective study of all consecutive cases of Transitional Cell Carcinomas of the Urinary Bladder diagnosed at Aga Khan University Hospital between 1st Jan 1997 and 31st Dec 2000. RESULTS: This study included 495 cases of Transitional Cell Carcinoma of the Urinary Bladder. M: F ratio was 4:1. Ages of patients ranged from 30 years to 87 years. Mean age in males was 59.1 years and in females 58.8 years. Forty four percent cases were Grade II, and 29.5% Grade III. None of the Grade I lesions were invasive, 10% Grade II tumours, 61.41% of Grade III and all Grade IV tumours were invasive. CONCLUSION: There is a definite correlation between advancing tumour grade and muscle invasion.

Adult↗
PubMed2002

Cancer patterns in Quetta (1998-1999).

INTRODUCTION: Quetta, the capital of Baluchistan, is located at latitude 30.25; longitude 67.00. It has a population of 759,245; 425,474 males (56%) and 333,771 females (44%); Census 1998. The majority of residents are Persian or Baluchi speaking Baluchs. METHODOLOGY: The cancer cases from Quetta reported to the Karachi Cancer Registry were reviewed. The data included cases from the Aga Khan University Hospital (AKUH), Pathology Department (Quetta collection point) and health care facilities in Karachi. The residents of Baluchistan were ascertained and cancer cases residents of Quetta identified with the help of recorded addresses and retraceable telephone numbers. RESULTS: During a 2-year period, 1st January 1998 to 31st December 1999 the Karachi Cancer Registry received 1077 cancer notifications from Quetta. Approximately half the cases were registered from the AKUH Quetta collection point. Others were the referral patterns in Karachi. The age-standardized incidence rate (ASR) of cancer, all sites (1998-99) was 137.0 for males and 92.8/100,000 for females. The commonest cancer in the males and females was cancer of the esophagus (ICD-10 categories C15; males- ASR 25.5, 17.2%; females-ASR 23.4,23.1%). One ofthe highest in the world, for both genders. Incidence of cancer breast in the females (ICD-10 categories C50; ASR 11.8, 13.3%) was low. CONCLUSION: The cancer data from Quetta is quite distinct from the cancer pattern of Karachi. It represents only a part of the cancer burden of Quetta; nonetheless it gives a glimpse into the cancer profile of Baluchistan. The high incidence of esophageal cancer indicates an extension of the geographical limits of the esophageal cancer belt.

Female↗