Synthesis and analysis of silica nanocarriers for pectinase immobilization: Enhancing enzymatic stability for continuous industrial applications

Pectinolytic enzymes are among the important group of industrial enzymes that have wide applications in different food industries. In this study, pectinase-based silica nanocarriers were synthesized using co-precipitation and cross-linking techniques. The resulting silica nanoparticles were investigated using scanning electron microscopy (SEM), energy-dispersive electron microscopy (EDEX), and X-ray diffraction (XRD) for determination of its morphology, elemental composition, and crystalline pattern. Under the optimal immobilization conditions like 1.5 % glutaraldehyde, 3000 IU/mg pectinase concentration, 90 min immobilization time and 40 °C immobilization temperature, pectinase showed maximum immobilization yield. The immobilization of pectinase onto the silica nanocarriers led to enhanced catalytic characteristics, displaying higher enzymatic activity across various temperature and pH levels compared to soluble pectinase. Moreover, the immobilization substantially improved the temperature stability of pectinase, exhibiting 100 % of its initial activity even after 120 h of pre-incubation at 50 °C. Additionally, the silica nanocarrier pectinase retained 100 % of its original activity even after being reused 10 times in a single batch of reactions. These findings indicate that the immobilization of silica nanocarriers effectively enhances pectinase's industrial capabilities, making it economically feasible for industrial use and an efficient system for various biotechnological applications.

Comparative analysis of dural substitute autologous vs. semisynthetic collagen-based dura graft

OBJECTIVE

The aim of the present study is to evaluate the success rate and safety of both auto-grafts and collagen-based semi-synthetic grafts in patients with dura defects.

PATIENTS AND METHODS

A prospective comparative study was conducted at the neurosurgery departments of different hospitals in Peshawar and Faisalabad. Patients were divided into two groups: A (autologous graft) and B (semi-synthetic graft). Dura graft autologous was applied in one group of patients with supratentorial brain surgery. Fascia lata was used, harvested from the lateral thigh, 3 to 5 cm long incision at the junction of the upper and middle one-third of the upper leg. A bone flap was implanted in the subcutaneous region in the abdominal part. Perioperative antibiotics were given to all the patients, and surgical drains placed intraoperatively were removed after 24 hours of surgery. In the second group, semi-synthetic dura grafts of 2.5x2.5 cm and 5x5 cm 7.5x7.5 cm sizes were used. Statistical analysis was performed using SPSS version v.20. Student's t-test was performed for the two groups to compare categorical variables, and the data were considered statistically significant at p > 0.05.

RESULTS

In this study, 72 patients of both genders were recruited. We observed that the Semi-synthetic collagen matrix had less surgical time. The mean difference in surgical duration was observed as 40 minutes. However, both groups reported statistically significant differences in terms of surgical duration (< 0.001). No case of infection was reported in both groups. The overall mortality ratio was 12%. Two male deaths were recorded due to cardiovascular disorders, while one death of a 42-year male was also recorded.

CONCLUSIONS

Based on the above findings, it may be concluded that using a semi-synthetic collagen substitute for dura repair is a simple, safe, and effective alternative to the autologous graft for dura repair in dura defects.

Development of Pectinase Based Nanocatalyst by Immobilization of Pectinase on Magnetic Iron Oxide Nanoparticles Using Glutaraldehyde as Crosslinking Agent

To increase its operational stability and ongoing reusability, B. subtilis pectinase was immobilized on iron oxide nanocarrier. Through co-precipitation, magnetic iron oxide nanoparticles were synthesized. Scanning electron microscopy (SEM) and energy dispersive electron microscopy (EDEX) were used to analyze the nanoparticles. Pectinase was immobilized using glutaraldehyde as a crosslinking agent on iron oxide nanocarrier. In comparison to free pectinase, immobilized pectinase demonstrated higher enzymatic activity at a variety of temperatures and pH levels. Immobilization also boosted pectinase's catalytic stability. After 120 h of pre-incubation at 50 °C, immobilized pectinase maintained more than 90% of its initial activity due to the iron oxide nanocarrier, which improved the thermal stability of pectinase at various temperatures. Following 15 repetitions of enzymatic reactions, immobilized pectinase still exhibited 90% of its initial activity. According to the results, pectinase's catalytic capabilities were enhanced by its immobilization on iron oxide nanocarrier, making it economically suitable for industrial use.

Range of factors in the reduction of hyperhydricity associated with in vitro shoots of Salvia santolinifolia Bioss

Hyperhydricity is a serious physiological disorder and affects In vitro propagation of many plants and as well of Salvia santolinifolia. The donor material to initiate the in vitro culture was the callus taken from the in vitro shoots produced on Murashig and Skoogs (MS) medium at 4.0 mg/l BA. This callus formed numerous hyperhydric shoots on culturing upon the medium of the same composition. The aim was to systematically evaluate the effect of cytokinins (Benzyladnine (BA) and N6-(-2-isopentenyl) adenine (2iP), culture vessels magnitude, medium solidification, source of nitrogen and calcium chloride for the alleviation of hyperhydricity. In the tissue cultures of S. santolinifolia BA and 2iP induced severe hyperhydricity, when other factors i.e. culture vessels magnitude and a suitable concentration of agar, ammonium nitrate (NH4NO3), potassium nitrate (KNO3) & calcium chloride (CaCl2.2H2O) were not optimized. After 30 days' culture, we observed 83.82% hyperhydric shoots at increased level (1.5 mg/l 2iP) and 81.59% at decreased levels (1.0 mg/l 2iP). On the other hand, hyperhydricity percentage at decreased (0.4%) and at increased (0.8%) levels of agar were 72.37% and 39.08%, respectively. MS medium modification with NH4NO3 (412 mg/l), KNO3 (475 mg/l) and CaCl2.2H2O (880 mg/l) was found the best medium to reduced hyperhydricity (23.6%).

Occurrence of Hymenolepis diminuta: a potential helminth of zoonotic importance in murid rodents

The study reveals the prevalence of a potential rodent-borne zoonotic helminth species, Hymenolepis diminuta in commensal rodents caught from irrigated and rain-fed areas of Swat, Pakistan. Three hundred and fifty rodents (269 rats and 81 mice) trapped during vegetative, flowering/fruiting and mature/harvesting stages of crops were studied from 2011-2013. Hymenolepisdiminuta eggs were identified on the basis of their shape, size, colour and markings on the surface of the egg shell and three pairs of embryonic hook-lets. Overall prevalence of H. diminuta was 3.14% (n=11/350). The highest prevalence 3.49% (n=5/143) of H. diminuta was noted at harvesting stages of the crops whereas the lowest 2.59% (n=2/77) during vegetative stage. Infection was higher in males 3.25% (n=7/215) than females 2.96% (n=4/135). Adult rodents were highly infected while no sub-adult was found infected. Infection was higher in mice 3.70% (3/81) than rats 2.69% (8/269) while no significance (p=1.0000:0.1250 to 32.00 CI). Rats and mice appears to show the most suitable reservoirs by hosting H. diminuta a zoonotic helminth. The presence of these rodents in all possible habitats can act as a main channel of transferring parasites through various habitats and can pose a hazard to humans in the area.

Preparation, characterization and stability studies of cross-linked α-amylase aggregates (CLAAs) for continuous liquefaction of starch

In current study, α-amylase of fungal origin was immobilized using cross-linking strategy. The influence of precipitant (ammonium sulphate) and cross-linker (glutaraldehyde) concentration revealed that 60% (w/v) precipitant and 1.5% (v/v) cross-linker saturation was required to attain optimum activity. Cross-linked amylase aggregates (CLAAs) were characterized and 10-degree shift in optimum temperature (soluble enzyme: 50 °C; cross-linked: 60 °C) and 1-unit shift in pH (soluble enzyme: pH -6; cross-linked: pH -7) was observed after immobilization. The V_max for soluble α-amylase and its cross-linked form was 1225 U ml^-1 and 3629 U ml^-1, respectively. The CLAAs was more thermostable than its soluble form and retained its 30% activity even after 60 min of incubation at 70 °C. Moreover, cross-linked amylase retained its activity after two months while its soluble counterpart lost its complete activity after 10 and 20 days at 30 °C and 4 °C storage, respectively. Reusability test showed that cross-linked amylase could retain 13% of its residual activity after 10 repeated cycles. Therefore, 10 times more glucose was produced after cross-linking than soluble amylase when it was utilized multiple times. This study indicates that amylase aggregates are highly effective for continuous liquefaction of starch, hence have strong potential to be used for different industrial processes.

Utilization of different polymers for the improvement of catalytic properties and recycling efficiency of bacterial maltase

Current study deals with the comparative study related to immobilization of maltase using synthetic (polyacrylamide) and non-synthetic (calcium alginate, agar-agar and agarose) polymers via entrapment technique. Polyacrylamide beads were formed by cross-linking of monomers, agar-agar and agarose through solidification while alginate beads were prepared by simple gelation. Results showed that the efficiency of enzyme significantly improved after immobilization and among all tested supports agar-agar was found to be the most promising and biocompatible for maltase in terms of immobilization yield (82.77%). The catalytic behavior of maltase was slightly shifted in terms of reaction time (free enzyme, agarose and polyacrylamide: 5.0 min; agar-agar and alginate: 10.0 min), pH (free enzyme, alginate and polyacrylamide: 6.5; agar-agar, agarose: 7.0) and temperature (free enzyme: 45 °C; alginate: 50 °C; polyacrylamide: 55 °C; agarose: 60 °C; agar-agar: 65 °C). Stability profile of immobilized maltase also revealed that all the supports utilized have significantly enhanced the activity of maltase at higher temperatures then its free counterpart. However, recycling data showed that agar-agar entrapped maltase retained 20.0% of its initial activity even after 10 cycles followed by agarose (10.0%) while polyacrylamide and alginate showed no activity after 8 and 6 cycles respectively.

Inhibitory mechanism of BAC-IB17 against β-lactamase mediated resistance in methicillin-resistant Staphylococcus aureus and application as an oncolytic agent

Cancer remains a foremost cause of deaths worldwide, despite several advances in the medical science. The conventional chemotherapeutic methods are not only harmful for normal body cells but also become inactive due to the development of resistance by cancer cells. Therefore, the demand of safe anticancer agents is increasing and enforced the bottomless research on the bacteriocins. Several studies have reported the selective anticancer property of bacteriocins. Current research is the contribution to explore the exact mechanism of action and in vitro application of bacteriocin (BAC-IB17) as an oncolytic agent. In this study, β-lactamase mediated resistance of methicillin resistant Staphylococcus aureus (MRSA) was studied and inhibitory mechanism of MRSA by BAC-IB17 was investigated. Cytotoxic studies were conducted to analyze the anticancerous potential of BAC-IB17. Results revealed that BAC-IB17 inhibited the β-lactamase and produced profound effect on the membrane integrity of MRSA confirmed by scanning electron microscope (SEM). FTIR spectroscopic analysis revealed the changes in the functional groups of bacterial cells before and after treatment with BAC-IB17. BAC-IB17 also found anticancer in nature as it kills HeLa cell lines with the IC₅₀ value of 12.5 μg mL^-1 with no cytotoxic effect on normal cells at this concentration. This specific anticancer property of BAC-IB17 will make it a promising candidate for the treatment of cancer after further clinical trials. Moreover, BAC-IB17 may control MDR bacteria responsible for the secondary complications in cancer patients.

Encapsulation of pectinase within polyacrylamide gel: characterization of its catalytic properties for continuous industrial uses

Pectinase as a biocatalyst play a significant role in food and textile industries. In this study, the pectinase was immobilized by encapsulation within polyacrylamide gel to enhance its catalytic properties and ensure the reusability for continuous industrial processes. 9.5% acrylamide and 0.5% N, N′- methylenebisacrylamide concentration gave high percentage of pectinase immobilization yield within gel. The catalytic properties of immobilized pectinase was determined with comparison of soluble pectinase. The immobilization of pectinase within polyacrylamide gel didn't effect catalytic properties of pectinase and both the free and immobilized pectinase showed maximum pectinolytic activity at 45 °C and pH 10. The Michaelis-Menten kinetic behavior of pectinase was slightly changed after immobilization and immobilized pectinase showed somewhat higher K_m and lower V_max value as compared to soluble pectinase. Polyacrylamide gel encapsulation enhanced the thermal stability of pectinase and encapsulated pectinase showed higher thermal stability against various temperature ranging from ranging from 30 °C to 50 °C as compared free pectinase. Furthermore, the surface topography of polyacrylamide gel was analyzed using scanning electron microscopy and it was observed that the surface topography of polyacrylamide gel was changed after encapsulation. The encapsulation of pectinase within polyacrylamide gel enhanced the possibility of reutilization of pectinase in various industries and pectinase retained more than 50% of its initial activity even after seven batch of reactions.

Maltose deterioration approach: Catalytic behavior optimization and stability profile of maltase from Bacillus licheniformis KIBGE-IB4

Maltase is an economically valuable enzyme that is used to catalyze the hydrolytic process of maltose and yields d-glucose as a product. In this study, the catalytic behavior of maltase was optimized under various physicochemical condition. Results indicated that bacterial maltase exhibited maximum catalytic activity at 45 °C and pH-6.5 after 5.0 min. It presented greater stability within 0.1 M K2HPO4 buffer having pH-6.5 and showed 100 % activity even after 1.0 h. It retained 83.6 % and 45.0 % activity at 40 °C after 1.0 and 3.0 h, respectively. The enzyme retained 90.0 % activity at -20 °C even after 60 days. The molecular weight of enzyme was deduced to be 157.2 kDa as calculated using polyacrylamide gel electrophoresis (PAGE) and zymography. It was concluded that the characterized maltase has notable stability profile with reference to temperature, pH and other reaction conditions which anticipates its utilization in various starch and maltose hydrolyzing processes for the synthesis of glucose.

Isolation and characterization of bacteriophage to control multidrug-resistant Pseudomonas aeruginosa planktonic cells and biofilm

Pseudomonas aeruginosa is Gram-negative bacterium, one of the leading cause of drug-resistant nosocomial infections in developing countries. This bacterium possesses chromosomally encoded efflux pumps, poor permeability of outer-membrane and high tendency for biofilm formation which are tools to confer resistance. Bacteriophages are regarded as feasible treatment option for control of resistant P. aeruginosa. The aim of the current study was isolate and characterized a bacteriophage against P. aeruginosa with MDR and biofilm ability. A bacteriophage MA-1 with moderate host range was isolated from waste water. The phage was considerable heat and pH stable. Electron microscopy revealed that phage MA-1 belongs to Myoviridae family. Its genome was dsDNA (≈50 kb), coding for eighteen different proteins (ranging from 12 to 250 KDa). P. aeruginosa-2949 log growth phase was significantly reduced by phage MA-1 (2.5 × 10³ CFU/ml) as compared to control (without phage). Phage MA-1 also showed significant reductions of 2.0, 2.5 and 3.2 folds in 24, 48, and 74 h old biofilms after 6 h treatment with phage respectively as compared to control. It was concluded from this study that phage MA-1 has capability of killing P. aeruginosa planktonic cells and biofilm, but for complete eradication cocktail will more effective to avoid resistance.

Improvement of catalytic properties of starch hydrolyzing fungal amyloglucosidase: Utilization of agar-agar as an organic matrix for immobilization

In this study, amyloglucosidase was immobilized within agar-agar through entrapment technique for the hydrolysis of soluble starch. Enzymatic activities of soluble and entrapped amyloglucosidase were compared using soluble starch as a substrate. Partially purified enzyme was immobilized and maximum immobilization yield (80%) was attained at 40 gL^-1 of agar-agar. Enzyme catalysis reaction time shifted from 5.0 min to 10 min after immobilization. Similarly, a five-degree shift in temperature (60 °C-65 °C) and a 0.5 unit increase in pH (pH-5.0 to pH-5.5) were also observed. Substrate saturation kinetics revealed that K_m of entrapped amyloglucosidase increased from 1.41 mg ml^-1 (soluble enzyme) to 3.39 mg ml^-1 (immobilized enzyme) whereas, V_max decreased from 947 kU mg^-1 (soluble enzyme) to 698 kU mg^-1 (immobilized enzyme). Entrapped amyloglucosidase also exhibited significant catalytic performance during thermal and storage stability when compared with soluble enzyme. Reusability of entrapped amyloglucosidase for hydrolysis of soluble starch demonstrated its recycling efficiency up to six cycles which is an exceptional characteristic for continuous bioprocessing of soluble starch into glucose.

Characterization and interplay of bacteriocin and exopolysaccharide-mediated silver nanoparticles as an antibacterial agent

Metallic nanoparticles have a substantial scientific interest because of their distinctive physicochemical and antimicrobial properties and the emergence of multidrug resistant pathogens could unlock the potential of nanoparticles to combat infectious diseases. The aim of the current study is to enhance the antibacterial potential of purified bacteriocin by combining bacteriocin and antibacterial silver nanoparticles (AgNPs). Hence, the interaction of natural antimicrobial compounds and antibacterial nanoparticles can be used as a potential tool for combating infectious diseases. In this study, a green, simple and effective approach is used to synthesize antibacterial AgNPs using fungal exopolysaccharide as both a reducing and stabilizing agent. The AgNPs were characterized by spectroscopic analysis, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDX) and Dynamic Light Scattering (DLS). Furthermore, the synergistic effect of bacteriocin-AgNPs was determined against pathogenic strains. The histogram of AgNPs indicated well-dispersed, stabilized and negatively charged particles with variable size distribution. The combination of bacteriocin with nanoparticles found to be more effective due to broad antibacterial potential with possibly lower doses. The current study is imperative to provide an alternative for the chemical synthesis of silver nanoparticles. It showed environmental friendly and cost effective green synthesis of antibacterial nanoparticles.

Small lymphocytic lymphoma with Reed Sternberg cells: a diagnostic dilemma

Reed Sternberg (RS) cells in the setting of small lymphocytic lymphoma (SLL) can complicate the histopathological diagnosis. We report a case of a man aged 54 years who presented with cervical lymphadenopathy. Resection of the lymph node was performed and sent for histopathological evaluation to a local laboratory. A diagnosis of SLL with Classic Hodgkin's lymphoma (CHL) was made. The medical oncologist who encountered this diagnosis for the first time sent the biopsy blocks to our laboratory for a second opinion. On review of the biopsy and immunohistochemical stains, it showed typical SLL morphology and immunophenotype. Focally, it showed large mononuclear RS type cells; however, no typical background of CHL was seen. The diagnosis was revised to 'SLL with RS like cells with no convincing evidence of CHL'. The patient was subsequently treated as a case of SLL and no progression was observed on a follow-up of 5 years.

Influence of different metals on the activation and inhibition of α-amylase from thermophilic Bacillus firmus KIBGE-IB28

Thermophilic Bacillus firmus KIBGE-IB28 produced extracellular α-amylase at temperature 70°C. Enzyme was partially purified by ammonium sulfate precipitation with 42.80 fold purification and specific activity of 1889.6 U/mg. Effects of various metals on enzyme activity were determined and it was found that enzyme activity boosted significantly in presence of Ca(2+), K(2+), Ba(2+), Co(2+) and Ni(2+) whereas Zn(2+), Mg(2+), Na(2+) and Cu(2+) were found inhibitory at concentration 10mM.

Study of the carbonaceous aerosol and morphological analysis of fine particles along with their mixing state in Delhi, India: a case study

Because of high emissions of anthropogenic as well as natural particles over the Indo-Gangetic Plains (IGP), it is important to study the characteristics of fine (PM2.5) and inhalable particles (PM10), including their morphology, physical and chemical characteristics, etc., in Delhi during winter 2013. The mean mass concentrations of fine (PM2.5) and inhalable (PM10) (continuous) was 117.6 ± 79.1 and 191.0 ± 127.6 μg m(-3), respectively, whereas the coarse mode (PM10-2.5) particle PM mass was 73.38 ± 28.5 μg m(-3). During the same period, offline gravimetric monitoring of PM2.5 was conducted for morphological analysis, and its concentration was ~37 % higher compared to the continuous measurement. Carbonaceous PM such as organic carbon (OC) and elemental carbon (EC) were analyzed on the collected filters, and their mean concentration was respectively 33.8 and 4.0 μg m(-3) during the daytime, while at night it was 41.2 and 10.1 μg m(-3), respectively. The average OC/EC ratio was 8.97 and 3.96 during the day and night, respectively, indicating the formation of secondary organic aerosols during daytime. Effective carbon ratio was studied to see the effect of aerosols on climate, and its mean value was 0.52 and 1.79 during night and day, indicating the dominance of absorbing and scattering types of aerosols respectively into the atmosphere over the study region. Elemental analysis of individual particles indicates that Si is the most abundant element (~37-90 %), followed by O (oxide) and Al. Circularity and aspect ratio was studied, which indicates that particles are not perfectly spherical and not elongated in any direction. Trajectory analysis indicated that in the months of February and March, air masses appear to be transported from the Middle Eastern part along with neighboring countries and over Thar Desert region, while in January it was from the northeast direction which resulted in high concentrations of fine particles.

Reversal of haloperidol induced motor deficits in rats exposed to repeated immobilization stress

Stress is defined as a non specific response of body to any physiological and psychological demand. Preclinical studies have shown that an uncontrollable stress condition produces neurochemical and behavioral deficits. The present study was conducted to test the hypothesis that a decrease in the responsiveness of somatodendritic 5-hydroxytryptamine (5-HT)-1A receptors following adaptation to stress could attenuate haloperidol induced acute parkinsonian like effect. Results showed that single exposure (2h) to immobilization stress markedly decreased food intake, growth rate and locomotor activity but these stress-induced behavioral deficits were not observed following repeated (2h/day for 5 days) exposure of immobilization stress suggesting behavioral tolerance occurs to similar stress. An important finding of present study is a reversal of haloperidol-induced motor deficits in animals exposed to repeated immobilization stress than respective control animals. It is suggested that stress induced possible desensitization of somatodendritic 5-HT-1A as well as 5-HT-2C receptors could release dopamine system from the inhibitory influence of serotonin. On the other hand, an increase in the effectiveness of postsynaptic 5-HT-1A receptors elicits a direct stimulatory influence on the activity of dopaminergic neuron and is possibly involved in the reversal of haloperidol-induced parkinsonian like symptoms in repeatedly immobilized rats.

Saccharification and liquefaction of cassava starch: an alternative source for the production of bioethanol using amylolytic enzymes by double fermentation process

Background

Cassava starch is considered as a potential source for the commercial production of bioethanol because of its availability and low market price. It can be used as a basic source to support large-scale biological production of bioethanol using microbial amylases. With the progression and advancement in enzymology, starch liquefying and saccharifying enzymes are preferred for the conversion of complex starch polymer into various valuable metabolites. These hydrolytic enzymes can selectively cleave the internal linkages of starch molecule to produce free glucose which can be utilized to produce bioethanol by microbial fermentation.

Results

In the present study, several filamentous fungi were screened for production of amylases and among them Aspergillus fumigatus KIBGE-IB33 was selected based on maximum enzyme yield. Maximum α-amylase, amyloglucosidase and glucose formation was achieved after 03 days of fermentation using cassava starch. After salt precipitation, fold purification of α-amylase and amyloglucosidase increased up to 4.1 and 4.2 times with specific activity of 9.2 kUmg^-1 and 393 kUmg^-1, respectively. Concentrated amylolytic enzyme mixture was incorporated in cassava starch slurry to give maximum glucose formation (40.0 gL^-1), which was further fermented using Saccharomyces cerevisiae into bioethanol with 84.0% yield. The distillate originated after recovery of bioethanol gave 53.0% yield.

Conclusion

An improved and effective dual enzymatic starch degradation method is designed for the production of bioethanol using cassava starch. The technique developed is more profitable due to its fast liquefaction and saccharification approach that was employed for the formation of glucose and ultimately resulted in higher yields of alcohol production.

Evaluation of Pakgen 99mTc generators loaded with indigenous fission 99Mo

Fission produced 99Mo/99mTc generators, called Pakgen, have been manufactured at the PINSTECH generator production facility since 2000 for nuclear medicine applications in Pakistan. These generators were loaded with fission 99Mo imported from NTP South Africa. Recently production of fission 99Mo has begun in the Molybdenum-99 Production Facility at PINSTECH. Prior to use in the clinic, eight sets of generators were produced, 23 GBq and 74 GBq at time of calibration, and they were subjected to various quality control procedures recommended in the pharmacopoeia to assess their performance. The elution profile, volume, activity, pH, radionuclidic, chemical, radiochemical and biological purity, and expiry time of the eluates were examined. Labeling efficiency tests were also carried out with a number of the more widely used in vivo radiopharmaceutical kits like DTPA, MDP and MIBI. Performance of 99mTc generators loaded with locally produced and imported fission 99Mo was comparable, and the users of Pakgen generators were fully satisfied. The effect of a wet vs. a dry column on 99mTc yields of generators loaded with low and high activity was also studied for the first time.

Molecular analysis of human leukocyte antigen class I and class II allele frequencies and haplotype distribution in Pakistani population

AIM:

Distribution of HLA class I and II alleles and haplotype was studied in Pakistani population and compared with the data reported for Caucasoid, Africans, Orientals and Arab populations.

MATERIALS AND METHODS:

HLA class I and II polymorphisms in 1000 unrelated Pakistani individuals was studied using sequence-specific primers and polymerase chain reaction and assay.

RESULTS:

The most frequent class I alleles observed were A*02, B*35 and CW*07, with frequencies of 19.2, 13.7 and 20%, respectively. Fifteen distinct HLA-DRB1 alleles and eight HLA-DQB1 alleles were recognized. The most frequently observed DRB1 alleles which represented more than 60% of the subjects were DRB1 *03, *07, *11 and *15. The rare DRB1 alleles detected in this study were HLADRB1 *08 and *09, having frequencies of 0.9 and 1.7%, respectively. In addition, at DRB1-DQB1 loci there were 179 different haplotypes and 285 unique genotypes and the most common haplotype was DRB1*15-DQB1*06 which represented 17% of the total DRB1-DQB1 haplotypes. In our population, haplotype A*33-B*58-Cw*03 comprised 2.8% of the total class I haplotypes observed. This haplotype was seen only in the oriental populations and has not been reported in the African or European Caucasoid.

CONCLUSION:

Our study showed a close similarity of HLA class I and II alleles with that of European Caucasoid and Orientals. In Pakistani population, two rare loci and three haplotypes were identified, whereas haplotypes characteristic of Caucasians, Africans and Orientals were also found, suggesting an admixture of different races due to migration to and from this region.

Preparation of188Re-lanreotide peptide and its quality control

A simple method is described for the preparation of188Re-Lanreotide, a radiolabeled synthetic peptide derived from an analogue of somatostatin, using Lanreotide (50 μg) and stannous tartrate to which is added carrier-free188Re. The radiolabeling has been carried out with ~555 MBq (15 mCi) with a >95% labeling efficiency and no need for subsequent purification. ITLC and HPLC techniques were employed for monitoring the stability and labeling yield. Radiolabeling results in one major peak when analyzed by reverse-phase (RP) HPLC.

Gastrointestinal stromal tumors: a demographic, morphologic and immunohistochemical study

BACKGROUND AND AIM

There is limited published information on gastrointestinal stromal tumors (GIST) in the South Asian region. This study was conducted to describe the demographic characteristics, organ distribution and frequency of risk categories in cases of GIST referred to a tertiary hospital.

METHODS

Data pertaining to 37 cases of gastrointestinal stromal tumors received at the histopathology section of the Aga Khan University Hospital between December 2004 and July 2005 were analyzed. Immunohistochemical stains including vimentin, CD34, CD117 (c-kit), ASMA, desmin and S-100 were performed.

RESULTS

Of 37 tumors, 24 (64.9%) were from males. The mean age of the patients was 50.0 years (95% CI 45.3-54.6). Tumors were categorized as high risk (27 cases; 69.2%), intermediate risk (4 cases; 10.3%) and low risk (3 cases; 7.7%). The most common site of involvement was the stomach (29.7%), followed by small bowel (24.3%), mesentery (10.8%), pancreas (8.1%), rectum (2.7%) and retroperitoneum (2.7%). In 21.6% of cases, the site of origin was not specified. The mean age at diagnosis was 50.9 years (95% CI 45.5 - 56.3) in the high risk and 44.8 years (95% CI 28.6 - 60.9) in the intermediate risk category.

CONCLUSIONS

Cases of GIST referred to us were more frequently from men, most commonly from stomach or small bowel, mostly in the high risk category, and presented a decade earlier than in other reported series.

Flow cytometric and demographic analysis of t cell acute lymphoblastic leukemia in Pakistani population

BACKGROUND

This study was carried out to analyze the proportion of T cell acute lymphoblastic leukemia (TALL) among all acute lymphoblastic leukemia (ALL) in Pakistani population and its correlation with the demographic features. Accuracy of cell surface markers used in flow cytometric analysis of the leukemic cells was also determined.

METHODS

Data of 209 consecutive cases of acute lymphoblastic leukemia (ALL) presenting between July 1995 and July 2003 was analyzed. Flow cytometry was performed on all ALL cases using the standard protocols. TALL markers included CD3, CD5 and CD7.

RESULTS

Proportion of TALL among known ALL Pakistani patients was 17.22%. Mean age of the TALL patients was 17.2 years. Proportion of TALL was higher in adults than in children (21.95% vs. 14.17%). Overall in this study there were more male patients affected by TALL (25/36 or 69.40%) than females (11/36 or 30.60%). The female to male ratio among TALL patients was 1:2.27. However, the proportion (%) of TALL in females was higher than males (18.96% vs. 15.82 %) i, e, 1.2:1. CD7 was found to be the most sensitive among both adults & children. It was positive in 94.4% of the TALL cases.

CONCLUSION

Proportion of TALL among ALL in Pakistan is similar to that reported in this region, indicating a candidate association with geographical location and socioeconomic status. The reactivity of markers with TALL. cells was similar to what we expected based upon literature. However, due to some aberrant and cross reactivity displayed by each marker, we strongly recommend a panel approach including B and myeloid markers to ensure a correct diagnosis of TALL.

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.

Time-integrated thyroid dose for accidental releases from Pakistan Research Reactor-1

The two-hourly time-integrated thyroid dose due to radio-iodines released to the atmosphere through the exhaust stack of Pakistan Research Reactor-1 (PARR-1), under accident conditions, has been calculated. A computer program, PAKRAD (which was developed under an IAEA research grant, PAK/RCA/8990), was used for the dose calculations. The sensitivity of the dose results to different exhaust flow rates and atmospheric stability classes was studied. The effect of assuming a constant activity concentration (as a function of time) within the containment air volume and an exponentially decreasing air concentration on the time-integrated dose was also studied for various flow rates (1000-50000 m3 h(-1)). The comparison indicated that the results were insensitive to the containment air exhaust rates up to or below 2000 m3 h(-1), when the prediction with the constant activity concentration assumption was compared to an exponentially decreasing activity concentration model. The results also indicated that the plume touchdown distance increases with increasing atmospheric stability.

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.

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.

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.

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.

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.