CF-LIBS based elemental analysis of Saussurea simpsoniana medicinal plant: a study on roots, seeds, and leaves

The plant Saussurea Simpsoniana, which has been used in traditional medicine for its biocompatibility and abundant nutrients, offers a wide range of remedies. Local communities effectively utilize medicines derived from the plant's roots to treat various ailments such as bronchitis, rheumatic pain, and abdominal and nervous disorders. In this study, we present an elemental analysis of the chemical composition (wt%) of this medicinal plant using the laser-induced breakdown spectroscopy (LIBS) technique. In the air atmosphere, an Nd:YAG (Q-switched) laser operating at a wavelength of 532 nm is utilized to create plasma on the sample's surface. This laser has a maximum pulse energy of approximately 400 mJ and a pulse duration of 5 ns. A set of six miniature spectrometers, covering the wavelength range of 220-970 nm, was utilized to capture and record the optical emissions emitted by the plasma. The qualitative analysis of LIBS revealed the presence of 13 major and minor elements, including Al, Ba, C, Ca, Fe, H, K, Li, Mg, Na, Si, Sr, and Ti. Quantitative analysis was performed using calibration-free laser-induced breakdown spectroscopy (CF-LIBS), ensuring local thermodynamical equilibrium (LTE) and optically thin plasma condition by considering plasma excitation temperature and electron number density. In addition, a comparison was made between the results obtained from CF-LIBS and those acquired through energy-dispersive X-ray spectroscopy (EDX) analysis.

An Epidemic of Pediatric HIV From Reuse of Infusion Equipment in Pakistan

BACKGROUND

From April to June 2019, a total of 909 new HIV infections were identified in Larkana, Pakistan; 86% was children younger than 15 years. To identify the possible transmission links in this outbreak, a case-control study was conducted in June 2019.

METHODS

For cases, we selected a systematic random sample of 100 HIV-positive children from the screening list. We chose 2 age-matched and sex-matched controls from the neighborhood of each HIV-positive case. All selected children were tested using the World Health Organization-approved rapid diagnosis test algorithm. We interviewed the parents of each selected child about previous exposures to parenteral treatment and compared exposures of case and control children using conditional logistic regression.

RESULTS

The ages of the selected children ranged from 1 month to 10 years. More than 90% of both HIV+ and HIV- children had received outpatient health care from MBBS-qualified private physicians. Eighty-three percent of HIV+ children versus 46% of HIV- children had received health care from one private physician [adjusted odds ratio (aOR) = 29, 95% confidence interval (95% CI): 10 to 79]. Intravenous infusions during the last outpatient visit were reported by 29% of case versus 7% of controls (aOR 57, 95% CI: 2.9 to >1000), whereas no case children and 17% of control children had received only intramuscular injections (aOR 0, 95% CI: 0 to 41). Among cases, 94% had been given infusions through a drip set compared with 85% of control children (aOR = 7.7, 95% CI: 2.3 to 26). Infusions had been administered with reused IV drip sets in 70% of cases compared with 8% of controls (aOR = 197, 95% CI: 16 to 2400).

DISCUSSION

Private physicians reusing intravenous drip sets to treat outpatients seen in private practice were responsible for this HIV epidemic. Mapping and regulation of private practitioners were suggested.

Risk Factors of Dengue Fever in Urban Areas of Rawalpindi District in Pakistan During 2017: A Case Control Study

Background

During August 2017, increased numbers of suspected dengue fever cases were reported in the hospitals of Rawalpindi district. A case control study was conducted to determine the risk factors among urban areas, dengue serotype, and recommend preventive measures.

Objective

The objective of the investigation was to determine the risk factors among urban areas, dengue serotype, and recommend preventive measures.

Methods

A case was defined as having acute febrile illness with one or more of the following symptoms: retro-orbital pain, headache, rash, myalgia, arthralgia, and hemorrhage. The cases were residents of Rawalpindi and were confirmed for dengue fever from August 30, 2017, to October 30, 2017. All NS1 confirmed cases from urban areas of Rawalpindi were recruited from tertiary care hospitals. Age- and sex-matched controls were selected from the same community with a 1:1 ratio. Frequency, univariate, and multivariate analyses were performed at 95% CI with P<.05 considered statistically significant.

Results

Totally 373 cases were recruited. The mean age was 36 (SD 2.9) years (range 10-69 years), and 280 cases (75%) were male. The most affected age group was 21-30 years (n=151, attack rate [AR] 40%), followed by 31-40 years (n=66, AR 23%). Further, 2 deaths were reported (case fatality rate of 0.53%). The most frequent signs or symptoms were fever (n=373, 100%), myalgia and headache (n=320, 86%), and retro-orbital pain (n=272, 73%). Serotype identification was carried out in 322 cases, and DEN-2 was the dominant serotype (n=126, 34%). Contact with a confirmed dengue case (odds ratio [OR] 4.27; 95% CI 3.14-5.81; P<.001), stored water in open containers at home (OR 2.04; 95% CI 1.53-2.73; P<.001), and travel to a dengue outbreak area (OR 2.88; 95% CI 2.12-3.92; P<.001) were the main reasons for the outbreak, whereas use of mosquito repellents (OR 0.12; 95% CI 0.09-0.18; P<.001) and regular water supply at home (OR 0.03; 95% CI 0.02-0.04; P<.001) showed protective effects. The geographical distribution of cases was limited to densely populated areas and all the 5 randomly collected water samples tested positive for dengue larvae.

Conclusions

Stored water in containers inside houses and subsequent mosquito breeding were the most probable causes of this outbreak. Based on the study findings, undertaking activities to improve the use of mosquito repellents and removing sources of breeding (uncovered water stored indoors) are some recommendations for preventing dengue outbreaks.

Risk Factors Associated with a Dengue Fever Outbreak in Islamabad, Pakistan: Case-Control Study

Background

On October 23, 2016, 79 dengue fever cases were reported from the Union Council Tarlai to Federal Disease Surveillance and Response Unit Islamabad. A team was established to investigate the suspected dengue outbreak.

Objective

The aim of this study was to determine the extent of the outbreak and identify the possible risk factors.

Methods

Active case finding was performed through a house-to-house survey. A case was defined as an acute onset of fever ≥38℃ in a resident of Tarlai from October 2 to November 11, 2016, with a positive dengue virus (nonstructural protein, NS-1) test and any of the two of following signs and symptoms: retroorbital/ocular pain, headache, rash, myalgia, arthralgia, and hemorrhagic manifestations. A structured questionnaire was used to collect data. Age- and sex-matched controls (1:1) were identified from residents in the same area as cases. Blood samples were taken and sent to the National Institute of Health for genotype identification.

Results

During the active case search, 145 cases of dengue fever were identified by surveying 928 houses from October 23 to November 11, 2016. The attack rate (AR) was 17.0/10,000. The mean age was 34.4 (SD 14.4) years. More than half of the cases were male (80/145, 55.2%). Among all cases, 29% belonged to the 25-34 years age group and the highest AR was found in the 35-44 years age group (35.6/10,000), followed by the 55-64 years age group (35.5/10,000). All five blood samples tested positive for NS-1 (genotype DENV-2). The most frequent presenting signs/symptoms were fever and headache (both 100%). Stagnant water around houses (odds ratio [OR] 4.86, 95% CI 2.94-8.01; P<.001), presence of flower pots in the home (OR 2.73, 95% CI 1.67-4.45; P<.001), and open water containers (OR 2.24, 95% CI 1.36-3.60; P<.001) showed higher odds among cases. Conversely, use of bed nets (OR 0.44, 95% CI 0.25-0.77; P=.003), insecticidal spray (OR 0.33, 95% CI 0.22-0.55; P<.001), door screens (OR 0.27, 95% CI 0.15-0.46; P<.001), mosquito coil/mat (OR 0.26, 95% CI 0.16-0.44; P<.001), and cleanliness of the house (OR 0.12, 95% CI 0.05-0.26; P<.001) showed significant protective effects.

Conclusions

Stagnant water acting as breeding grounds for vectors was identified as the probable cause of spread of the dengue outbreak. Establishment of surveillance and an early reporting system along with use of protective measures against the vector are strongly recommended.

Morbidity and Mortality Associated with Typhoid Fever Among Hospitalized Patients in Hyderabad District, Pakistan, 2017-2018: Retrospective Record Review

BACKGROUND

Hyderabad, Pakistan, was the first city to witness an outbreak of extensively drug resistant (XDR) typhoid fever. The outbreak strain is resistant to ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole, fluoroquinolones, and third-generation cephalosporin, thus greatly limiting treatment options. However, despite over 5000 documented cases, information on mortality and morbidity has been limited.

OBJECTIVE

To address the existing knowledge gap, this study aimed to assess the morbidity and mortality associated with XDR and non-XDR Salmonella serovar Typhi infections in Pakistan.

METHODS

We reviewed the medical records of culture-confirmed typhoid cases in 5 hospitals in Hyderabad from October 1, 2016, to September 30, 2018. We recorded data on age, gender, onset of fever, physical examination, serological and microbiological test results, treatment before and during hospitalization, duration of hospitalization, complications, and deaths.

RESULTS

A total of 1452 culture-confirmed typhoid cases, including 947 (66%) XDR typhoid cases and 505 (34%) non-XDR typhoid cases, were identified. Overall, ≥1 complications were reported in 360 (38%) patients with XDR typhoid and 89 (18%) patients with non-XDR typhoid (P<.001). Ileal perforation was the most commonly reported complication in both patients with XDR typhoid (n=210, 23%) and patients with non-XDR typhoid (n=71, 14%) (P<.001). Overall, mortality was documented among 17 (1.8%) patients with XDR S Typhi infections and 3 (0.6%) patients with non-XDR S Typhi infections (P=.06).

CONCLUSIONS

As this first XDR typhoid outbreak continues to spread, the increased duration of illness before hospitalization and increased rate of complications have important implications for clinical care and medical costs and heighten the importance of prevention and control measures.

Risk Factors of Extensively Drug Resistant Typhoid Fever Among Children in Karachi: Case-Control Study

Background

Extensively drug resistant typhoid fever (XDR-TF) has been responsible for an ongoing outbreak in Pakistan, which began in November 2016.

Objective

This study aimed to determine the risk factors associated with XDR-TF.

Methods

This age- and sex-matched case-control study was conducted during May-October 2018 in Karachi. All patients with XDR-TF were identified from the laboratory-based surveillance system data. Cases included patients aged <15 years living in Karachi with culture-positive Salmonella enterica serovar Typhi with resistance to chloramphenicol, ampicillin, trimethoprim/sulfamethoxazole, fluoroquinolones, and third-generation cephalosporins. Age- and sex-matched controls included children free from the symptoms of TF, aged under 15 years, and residing in Karachi. All controls were recruited from among those who attended outpatient clinics.

Results

A total of 75 cases and 75 controls were included in this study. On univariate analysis, the odds of having XDR-TF were 13-fold higher among participants who used piped municipal water than among those who did not (odds ratio [OR] 12.6, 95% CI 4.1-38.6). The use of bore water was significantly associated with XDR-TF (OR 5.1, 95% CI 1.4-19.0). Cases were more likely to report eating French fries with sauce (OR 13.5, 95% CI 3.9-47.0) and poppadum (OR 3.4, 95% CI 1.7-6.7) from street vendors than controls. Boiling water at home was negatively associated with XDR-TF (OR 0.3, 95% CI 0.2-0.7). On multivariate analysis, 2 factors were independently associated with XDR-TF. Using piped municipal water (OR 10.3, 95% CI 3.4-30.4) and eating French fries with sauce from street vendors (OR 8.8, 95% CI 2.1-36.2) were significantly associated with an increased odds of XDR-TF.

Conclusions

Community water supply and street food eating habits were implicated in the spread of the superbug S typhi outbreak, which continues to grow in Karachi. Therefore, it is recommended to improve the community water supply to meet recommended standards and to develop a policy to improve the safety of street food. In addition, health authorities are required to conduct mass vaccination for TF among high-risk groups.

Systematic Review of Reported HIV Outbreaks, Pakistan, 2000-2019

In the absence of robust testing programs, timely and detailed outbreak reporting is essential for HIV control.

Unsafe injection practices and injection drug use have been linked to multiple HIV outbreaks in Pakistan since 2003; however, few studies have systematically analyzed the causes of these outbreaks. We conducted a systematic review of published English-language literature indexed in bibliographic databases and search engines and a focused gray literature review to collate and analyze all reported HIV outbreaks in Pakistan during 2000–2019. Of 774 unique publications reviewed, we identified 25 eligible publications describing 7 outbreaks. More than half occurred during 2016–2019. The primary sources of transmission were iatrogenic transmission, affecting children, persons with chronic medical conditions, and the general population (4 outbreaks); injection drug use (2 outbreaks); and a combination of both (1 outbreak). In the absence of robust HIV testing and surveillance in Pakistan, timely and detailed outbreak reporting is important to understand the epidemiology of HIV in the country.

Rising HIV seroconversion rates & associated risks among employees of organization 'X': A case control study, Pakistan, 2017

Background and Objectives:

In 2004 Pakistan escalated from ‘low-prevalence’ to ‘concentrated’ phase of HIV epidemic. Despite global decline in HIV incidence since 1997, rate of HIV infections in Pakistan is persistently rising since 1990. Available literature focusses on key populations or localized outbreaks limited by short study duration and regional applicability of results. We studied HIV seroconversion trends over a period of 8 years in a geographically diverse population and evaluated associated risk factors.

Methods:

A desk review of HIV surveillance data from 2010 to 2017 was carried out at Armed Forces Institute of Pathology. A case was defined as any adult employed in organization ‘X’, initially screened for HIV but later seroconverted on ELISA and western blot. Case-control study was conducted on cases diagnosed in 2017. Age and sex matched controls were identified from same population sub-group. Structured telephonic interviews were conducted and statistical analysis done at 5% margin of error.

Results:

The annual HIV diagnosis rate remained relatively stable till 2015 (< 40 /100,000/yr) after which it rose sharply to 60/100,000/yr in 2016 .Upward trend continued in 2017 to reach 125/100,000/yr (>200% increase from baseline). Acquisition of HIV was significantly associated with commercial sex activities (OR=9; 95% CI: 1.25-395).

Conclusion:

HIV seroconversion rates among employees of organization X have increased significantly in the past two years. Unlike HIV outbreaks previously reported from Pakistan, sexual route seems to be the predominant mode of transmission. Focus is mandated on prevention of sexual transmission of HIV at national level as well for all vulnerable populations.

Knowledge, Awareness, and Health-Seeking Behaviour regarding Tuberculosis in a Rural District of Khyber Pakhtunkhwa, Pakistan

BACKGROUND

Pakistan is a country with one of the highest burden of tuberculosis (TB) in the world, and therefore, it is imperative to revisit the design of behaviour change interventions in the program. This study was designed to understand and assess the knowledge, awareness, perceptions, and health-seeking behaviour of general and specifically TB-affected population and to determine the presence and level of stigma and discrimination toward TB patients.

METHODS

A mixed-method study was conducted in district Haripur of the Khyber Pakhtunkhwa province, comprising a household survey, whereby 526 individuals were interviewed, and five focus group discussions with various subgroups including TB patients and health workers and authorities. Study sought an ethical approval, and data of all respondents was kept confidential.

RESULTS

Quantitative results show that women were more knowledgeable on symptomatology and spread of TB, and with rising education, awareness on TB improves. The majority of our respondents had the understanding that it is a curable disease, yet some would avoid TB patients. Most of the respondents (both men and women) knew that one must go to a government facility for treatment. Only one-third would speak to doctor first, if they suspect TB-like symptoms. Television was a popular source of information on TB. Qualitative results captured people's perceptions that TB was related with poverty and was still considered a stigma in the community; hence, patients afflicted feared disclosing the disease.

CONCLUSION

With contextual understanding of communities' knowledge, attitudes, health-seeking behaviour, and care-seeking patterns, it can be concluded that there is a need to increase the awareness about TB symptoms, mode of transmission, prevention, diagnosis and treatment, and destigmatization of the disease through health education.

The Role of the Global Health Development/Eastern Mediterranean Public Health Network and the Eastern Mediterranean Field Epidemiology Training Programs in Preparedness for COVID-19

The World Health Organization (WHO) declared the current COVID-19 a public health emergency of international concern on January 30, 2020. Countries in the Eastern Mediterranean Region (EMR) have a high vulnerability and variable capacity to respond to outbreaks. Many of these countries addressed the need for increasing capacity in the areas of surveillance and rapid response to public health threats. Moreover, countries addressed the need for communication strategies that direct the public to actions for self- and community protection. This viewpoint article aims to highlight the contribution of the Global Health Development (GHD)/Eastern Mediterranean Public Health Network (EMPHNET) and the EMR’s Field Epidemiology Training Program (FETPs) to prepare for and respond to the current COVID-19 threat. GHD/EMPHNET has the scientific expertise to contribute to elevating the level of country alert and preparedness in the EMR and to provide technical support through health promotion, training and training materials, guidelines, coordination, and communication. The FETPs are currently actively participating in surveillance and screening at the ports of entry, development of communication materials and guidelines, and sharing information to health professionals and the public. However, some countries remain ill-equipped, have poor diagnostic capacity, and are in need of further capacity development in response to public health threats. It is essential that GHD/EMPHNET and FETPs continue building the capacity to respond to COVID-19 and intensify support for preparedness and response to public health emergencies.

Multiplex real-time RT-PCR assay for transfusion transmitted viruses in sero-negative allogeneic blood donors: an experience from Southern Pakistan

BACKGROUND

Blood transfusion safety commences with healthy donor recruitment. The threat of transfusion transmitted infections is greatly minimized by serological tools but not entirely eliminated. Recently, nucleic-acid testing for blood donor screening has virtually eliminated this jeopardy.

METHODS

This prospective study was conducted from February 2015 to February 2016. Samples from seronegative donors were run on multiplex assay (Cobas, S-201 system platform, Roche) in a batch of six [MP-NAT]. In case of reactive pool, tests were run on every individual sample [IDNAT].

RESULTS

Of 16957 donors, 16836 (99.2%) were replacement donors and the remaining 121 (0.7%) were voluntary donors, with a mean age of 29.09 ± 7.04 years. After serologic screening of all 16957 donors, 955 (5.6%) were found to be reactive; 291(1.71%) were reactive for hepatitis-B surface antigen, 361 (2.12%) for antibody to hepatitis C virus (anti-HCV), 14 (0.08%) for antibody to human immunodeficiency virus, 287 (1.69%) for syphilis and 2 (0.01%) for malaria. 14 (0.08%) NAT reactive donors were identified after testing the 16002 seronegative donors, with an overall NAT yield of one reactivity out of 1143 blood donations; 10 donors for HBV-DNA (HBV NAT yield-1:1600) and remaining 4 for HCV-RNA (HCV-NAT yield-1:4000). None were HIV positive.

CONCLUSION

NAT has improved the safety attributes in blood products. Although the positivity rate for NAT testing is low but in view of the high prevalence of transfusion transmitted infections in our country, we recommend the parallel use of both serology and NAT screening of all donated blood.

Grain Size and Interface Dependence of Bias Stress Stability of n-Type Organic Field Effect Transistors

The effect of grain size and interface dependence of bias stress stability of C60-based n-type organic field effect transistors (OFETs) has been studied. It has been realized that, with increasing grain size of C60, the bias stress induced threshold voltage shift can be controlled and this effect is mainly attributed to the mechanism of charge trapping at grain boundaries. It is further studied that the growth of C60 on the surface of parylene at elevated substrate temperature leads to the creation of radicals at the interface between the active layer and the gate dielectric. These radicals help to improve the bias stress stability of C60-based n-type OFETs. For achieving the bias stress stability, we have presented a procedure of creation of radicals at the interface between C60 and parylene in single gate OFETs instead of dual gate OFETs.

Public health surveillance at a mass gathering: urs of Baba Farid, Pakpattan district, Punjab, Pakistan, December 2010

The objective of this study was to identify health related problems encountered during an annual mass gathering in Pakpattan, Pakistan, the anniversary of the death (urs) of Baba Farid, and to make recommendations for planning and prevention activities. A surveillance system was established to capture health related data for the event. A list of reportable diseases was developed. Data were collected pre-, during, and post-event by health care workers trained for the purpose. A total of 5918 people reported to the 15 health care facilities providing services during the event; 58% of consultations were because of communicable diseases, 21% of which were respiratory tract infections and 26% gastrointestinal illness. Injuries accounted for 31% of cases and noncommunicable diseases for 11%. Prevalence of reportable disease during the event showed sizeable increases. No major disease outbreak was observed.

Disease surveillance system: a mandatory conduit for effective control of infectious diseases in Pakistan

In Pakistan, absence of a nationwide surveillance mechanism and strategy is the main reason for the failure in effectively controlling communicable diseases. The seasonal outbreaks of various infectious diseases every year call for an integrated surveillance system on a national level for planning effective preventive strategies. Opportunity to adopt a tested and tried model exists at this time in terms of the "Disease Early Warning System" set up by World Health Organization in conflict-affected districts. Replicating this system in other districts is both practical and feasible as technical support is readily available through the World Health Organization. Such a system once put in place has potential to not only decrease morbidity and mortality through early detection and prompt control of outbreaks but also to facilitate effective financial, human resource, and materials management at the district level. This would be a step toward a more responsive health system at the local level.

Nanostructured materials for water desalination

Desalination of seawater and brackish water is becoming an increasingly important means to address the scarcity of fresh water resources in the world. Decreasing the energy requirements and infrastructure costs of existing desalination technologies remains a challenge. By enabling the manipulation of matter and control of transport at nanometer length scales, the emergence of nanotechnology offers new opportunities to advance water desalination technologies. This review focuses on nanostructured materials that are directly involved in the separation of water from salt as opposed to mitigating issues such as fouling. We discuss separation mechanisms and novel transport phenomena in materials including zeolites, carbon nanotubes, and graphene with potential applications to reverse osmosis, capacitive deionization, and multi-stage flash, among others. Such nanostructured materials can potentially enable the development of next-generation desalination systems with increased efficiency and capacity.

On-line monitoring of remediation process of chromium polluted soil using LIBS

Due to large growth in leather and textile industries to cater for the needs of a growing world population, contamination of soil and water resources by chromium has become a great threat for humans and animals. In this work, Laser Induced Breakdown Spectroscopy (LIBS) was applied to monitor the remediation process of soil contaminated with Chromium metal. This study was conducted at a laboratory scale by setting up an experiment in a container holding soil contaminated with chromium. This setup represents actual field conditions where remediation process could be applied and monitored for the removal of toxic metals like Cr. For generation of LIBS spectrum, the plasma was produced by focusing a pulsed Nd: YAG laser at 1064 nm on the soil contaminated with chromium under remediation process. The evaluation of the potential and capabilities of LIBS as a rapid tool for remediation process of contaminated sites is discussed in detail. Optimal experimental conditions were evaluated for improving the sensitivity of our LIBS system for monitoring of remediation process through parametric dependence study. The minimum detection limit of our spectrometer for chromium in soil matrix was 2 mg Kg(-1).

Measurement of nutrients in green house soil with laser induced breakdown spectroscopy

Laser-induced breakdown spectroscopy (LIBS) has been applied for the determination of nutrients in the green house soil samples. We determined appropriate spectral signatures of vital nutrients and calibrated the method to measure the nutrients in a naturally fertilized plot, cultivated with tomato and cucumber plants. From the calibration curves we predicted the concentrations of important nutrients such as Ca, K, P, Mg, Fe, S, Ni and Ba in the soil. Our measurements proved that the LIBS method rapidly and efficiently measures soil nutrients with excellent detection limits of 12, 9, 7, 9, 7, 10, 8 and 12 mg/kg for Ca, K, P, Mg, Fe, S, Ni and Ba respectively with a precision of approximately 2%, The unique features of LIBS for rapid sample analysis demonstrated by this study suggests that this method offers promise for precision measurements of soil nutrients as compared to conventional methods in short span of time.

Intravitreal steroids may facilitate treatment of Eales' disease (idiopathic retinal vasculitis): an interventional case series

PURPOSE

Eales' disease is an idiopathic peripheral perivasculitis leading to proliferative vascular retinopathy, recurrent vitreous haemorrhages, and tractional retinal detachment. It is an elusive cause of blindness in young, otherwise healthy individuals. We studied the effects of intravitreal triamcinolone acetonide (IVTA) in patients of Eales' disease, which may eventually reduce the side effects and cost of management, with results equivalent to or better than oral steroids.

METHODS

Ethics approval and prior patient consent were obtained. Fluorescein fundus angiograms (FFAs) of 12 eyes of 12 Eales' disease patients were taken before enrolment. These patients received 0.1 ml of 40 mg/ml (4 mg) intravitreal triamcinolone through pars plana under topical anaesthesia. Regular weekly follow-ups were initiated to ascertain Snellen visual acuity, intraocular pressure (IOP) with Goldman tonometer, and triple mirror examination. Fluorescein fundus angiography was again performed in the 8th week to monitor response to treatment. Decrease in areas of late perivascular dye extravasation on fluorescein angiography was used as marker for improvement.

RESULTS

Ten out of a total of 12 (83.33%) eyes treated with IVTA showed significant reduction of late leakage from retinal vessels on fluorescein fundus angiography. Two out of 12 eyes (16.67%) did not show considerable decrease in late perivascular fluorescein dye leakage after 8 weeks of intravitreal triamcinolone injection. Two patients (16.67%) had a significant rise in IOP after IVTA.

CONCLUSION

Intravitreal steroids may be advocated for management of idiopathic retinal vasculitis without complications of systemic steroids, and minimize need for more invasive procedures.

Effect of polyols and salts on the acid-induced state of human placental cystatin

Polyols (glycerol and sorbitol) and salts (magnesium sulfate, sodium sulfate, and magnesium chloride) have been used to study the refolding of the acid-induced state of human placental cystatin (HPC), which is a low molecular weight (12,500 daltons) thiol proteinase inhibitor, in terms of CD spectroscopy, binding of hydrophobic dye 1-anilinonaphthalene-8-sulfonic acid (ANS), and intrinsic fluorescence measurements. The helical content of acid-denatured HPC increased with increase in glycerol concentration (0-80%). At 80% glycerol concentration, the secondary structural features observed in the far UV-CD region are similar to those of the native state (pH 6.0). The intrinsic fluorescence and near UV-CD studies showed that this 80% glycerol-induced state has a significant amount of tertiary structure with decreased ANS binding compared to the acid-denatured state. It was found that glycerol is more effective in stabilizing the acid-denatured state of HPC as compared to sorbitol. Among salts the stability effect was more for MgCl(2) (used up to concentration of 3 M) compared to MgSO(4) and Na(2)SO(4) (used up to the concentration of 1.5 M due to restricted solubility of HPC at higher sulfate salt concentrations) as determined by CD studies and fluorescence measurements, which showed secondary and tertiary structural resemblance of this MgCl(2)-induced state close to native state and showed overall spectral features in between the native state and the acid-denatured state. This MgCl(2) (3 M)-induced state showed decreased ANS fluorescence as compared to the acid-denatured state but more than that of the native state. The results taken together suggest that the acid-denatured state of HPC in the presence of 80% glycerol or 3 M MgCl(2) has a conformation in between that of the native state (pH 6.0) and the acid-induced state at pH 2.0.

Inducing systemic and mucosal immune responses to B-T construct of F1 antigen of Yersinia pestis in microsphere delivery

Plague is a zoonotic disease caused by Yersinia pestis, an etiological agent of pneumonic and bubonic plague. There is a need for an improved plague vaccine that may overcome the limitation of presently available whole cell vaccine. An alternative approach described here, is the use of protective epitopes from immunodominant antigen of Y. pestis. One such antigen is the F1 antigen, a major envelope and virulent protein that possess antiphagocytic and anti-microbial properties. The present study was aimed to develop a peptide-based vaccine, based upon the constructs made between B and T cell epitopes of F1 antigen of Y. pestis. The immunogenicity, IgG subclass pattern, affinity, avidity and in vivo protective efficacy of the antibodies generated for different B-T constructs were studied in murine model using microsphere as the delivery vehicle. The mode of immunization was both intranasal and intramuscular, with single and multiple doses of immunization, respectively. Intranasal immunization generated consistent high titre and long lasting immune response both for IgG and IgA in sera and sIgA in washes while intramuscular route generated peak IgG levels in sera only. The IgG isotypic levels pattern showed higher IgG2a/IgG2b levels in intranasal route while mixed isotypic levels of IgG1, IgG2a/IgG2b were observed in intramuscular route. The affinity and relative avidity of antibodies showed best results with intranasal route as compared to the intramuscular route. The specific activity measurement (IgG/IgA content) in sera and washes were well correlated with the antibody levels. Finally, in vivo protective studies showed that B1T1 and B2T1 conjugates protected the mice till day 15 while rest of the conjugates showed poor protection.

Molten globule state of human placental cystatin (HPC) at low pH conditions and the effects of trifluoroethanol (TFE) and methanol

Acid-induced conformational changes were studied in human placental cystatin (HPC) in terms of circular dichroism (CD) spectroscopy, the binding of hydrophobic dye 1-anilinonapthalene-8-sulphonic acid (ANS), and intrinsic fluorescence measurements. Our results show the formation of an acid-induced molten globule state at pH 2.0, with significant secondary and tertiary interactions that resemble the native state, exposed hydrophobic regions and the effects of trifluoroethanol (TFE) and methanol in conversion of the acid-denatured state of HPC to the alcohol-induced state, which is characterized by increased helical content, disrupted tertiary structure, and the absence of hydrophobic clusters. Alcohol-induced formation of α-helical structures at pH 2.0 is evident from the increase in the ellipticity values at 222 nm, with native-like secondary structural features at 40% TFE. The increase in helical content was observed up to 80% TFE concentration. The ability of TFE (40%) to refold acid-denatured HPC to native-state conformation is also supported by intrinsic and ANS fluorescence measurements.Key words: human placental cystatin, molten globule, acid-induced state, trifluoroethanol, methanol, CD spectroscopy, ANS fluorescence, pH, protein folding.

Simultaneous selection of the wild-type genotypes of the G894T and 4B/ 4A polymorphisms of NOS3 associate with high-altitude adaptation

The routine performance of high-altitude (HA) natives in the hypoxic environment of HA exemplifies the process of adaptation mainly through natural selection. The recent therapeutic application of nitric oxide (NO) in HA disorders, for the improvement of oxygenation and vasodilation, ushered us to investigate the endothelial nitric oxide synthase gene (NOS3) with respect to HA adaptation. The study subjects, 131 HA monks (HAM), 136 HA controls (HAC), and 170 lowlanders (LLs) were screened for NOS3 G894T (Glu298Asp) and 4B/4A polymorphisms. The NO levels were estimated, for a correlation with the polymorphisms. The three groups were in Hardy-Weinberg equilibrium for the polymorphisms. The overall genotype distributions for the G894T and 4B/4A polymorphisms were significant (P = 0.01 and 0.02, respectively) in the three groups. Wild-type alleles G and 4B were significantly over-represented in the HA groups as compared to the LLs (P = 0.006 and P = 0.02, respectively). The NO levels were in the order of HAM>HAC>LLs (P < 0.0001). Furthermore, combinations of the GG and BB genotypes were distributed significantly more frequently in the HAM (P < 0.0001) and HAC (P = 0.0005) than in LLs. The NO levels contributed by the wild-type genotype combination GG, BB were significantly elevated when compared with the remaining eight genotype combinations together in the HAM, HAC and LLs (P = 0.003, P = 0.0006 and P < 0.0001, respectively). To conclude, the genotype combination of NOS3 wild-type homozygotes (GG, BB) was found significantly more frequently in HA groups than in LLs, by contributing to higher NO levels associated with HA adaptation.

Laboratory scale studies on removal of chromium from industrial wastes

Chromium being one of the major toxic pollutants is discharged from electroplating and chrome tanning processes and is also found in the effluents of dyes, paint pigments, manufacturing units etc. Chromium exists in aqueous systems in both trivalent (Cr(3+)) and hexavalent (Cr(6+)) forms. The hexavalent form is carcinogenic and toxic to aquatic life, whereas Cr(3+) is however comparatively less toxic. This study was undertaken to investigate the total chromium removal from industrial effluents by chemical means in order to achieve the Pakistan NEQS level of 1 mg/L by the methods of reduction and precipitation. The study was conducted in four phases. In phase I, the optimum pH and cost effective reducing agent among the four popular commercial chemicals was selected. As a result, pH of 2 was found to be most suitable and sodium meta bisulfate was found to be the most cost effective reducing agent respectively. Phase II showed that lower dose of sodium meta bisulfate was sufficient to obtain 100% efficiency in reducing Cr(6+) to Cr(3+), and it was noted that reaction time had no significance in the whole process. A design curve for reduction process was established which can act as a tool for treatment of industrial effluents. Phase III studies indicated the best pH was 8.5 for precipitation of Cr(3+) to chromium hydroxide by using lime. An efficiency of 100% was achievable and a settling time of 30 minutes produced clear effluent. Finally in Phase IV actual waste samples from chrome tanning and electroplating industries, when precipitated at pH of 12 gave 100% efficiency at a settling time of 30 minutes and confined that chemical means of reduction and precipitation is a feasible and viable solution for treating chromium wastes from industries.

Differential changes in the steady state levels of thylakoid membrane proteins during senescence in Cucumis sativus cotyledons

Chloroplast structure and function is known to alter during foliar senescence. Besides, the alterations in the structural organisation of thylakoid membranes changes in the steady state levels of thylakoid membrane proteins occur due to leaf ageing. We monitored temporal changes in some of the specific proteins of thylakoid membrane protein complexes by western blotting in the Cucumis sativus cotyledons as a function of the cotyledon age. We observed that the levels of D1 and D2 proteins of photosystem II started declining at the early stages of senescence of Cucumis cotyledons and continued to decline with the progress of cotyledon age. Similarly the level of Cyt f of Cyt b6/f complex declined rapidly with progress of senescence in these cotyledons. The reaction centre proteins of photosystem I were relatively found to be more stable than that of photosystem II reaction centre proteins reflecting possibly the disorganisation of photosystem II prior to photosystem I. The 33 kDa extrinsic protein (MSP) of oxygen evolving complex, the LHCII apoprotein and the beta-subunit of ATPsynthase showed the declined levels with the progress of cotyledon age. However, the extents of loss of these proteins were not as high as the reaction centre proteins of photosystem II and the Cyt f. These results provide that during senescence, proteins of thylakoid membranes degrade in a specific temporal sequence and thereby affect the temporal photochemical functions in Cucumis sativus cotyledons.

Senescence induced structural reorganization of thylakoid membranes in Cucumis sativus cotyledons; LHC II involvement in reorganization of thylakoid membranes

We report the formation and appearance of loosely stacked extended grana like structures along with plastoglobuli in the chloroplasts isolated from 27-day old senescing cucumber cotyledons. The origin and the nature of these extended grana structures have not been elucidated earlier. We isolated Photosystem I complexes from 6-day-old control and 27-day-old senescing cotyledons. The chlorophyll a/b ratio of the isolated Photosystem I complex obtained from 6-day cotyledons was 5-5.5 as against a ratio of 2.9 was found in Photosystem I complexes obtained from 27-day-old senescing cotyledons. We also found that the presence of LHC II in the Photosystem I complexes isolated from 27-day cotyledonary chloroplasts. The presence of LHC II in Photosystem I complexes in senescing and not in control samples, clearly suggest the detachment and diffusion of LHC II complexes from stacked grana region to Photosystem I enriched stroma lamellar region thereby, forming loose disorganized extended grana structures seen in the transmission electron microscope. Furthermore, we show that under in vitro condition the senescing cotyledon chloroplasts exhibited lower extent of light induced phosphorylation of LHC II than the control samples suggesting a possible irreversible phosphorylation and diffusion of LHC II in vivo during the progress of senescence in Cucumis cotyledons. From these findings, we suggest that the senescence induced phosphorylation of LHC II and its migration towards Photosystem I may be a programmed one some how causing the destruction of the thylakoid membrane. The released membrane components may be stored in the plastoglobuli prior to their mobilization to the younger plant parts.

Seroprevalence of HIV, HBV, and syphilis and associated risk behaviours in male transvestites (Hijras) in Karachi, Pakistan

In Pakistan, male sex workers are predominantly transvestites and transsexuals known as Hijras. In 1998 in Karachi, Pakistan, we studied the seroprevalence of HIV, HBsAg and syphilis and associated risk factors in Hijras. Study subjects were verbally administered a structured questionnaire that determined risk behaviours for sexually transmitted and blood-borne diseases and knowledge of AIDS/STDs. After pre-test counselling, verbal consent was taken for serological testing. The results were provided on a one-on-one post-test counselling session. Three hundred male transvestites were approached; all agreed to answer the questionnaire, 208 consented to blood testing. Of 300, 81% acknowledged commercial sex with men. Of 208, prevalence of syphilis was 37%; HBsAg 3.4%; HIV 0%. The prevalence of HIV and hepatitis B virus (HBV) is low in transvestite sex workers but that of syphilis is high. Intervention programmes implemented at this stage can have an impact on HIV and STD prevention.

Age dependent alterations in photosystem II acceptor side in Cucumis sativus cotyledonary leaf thylakoids: analysis of binding characteristics of herbicide [14C]-atrazine

Senescence induced temporal changes in photosystems can be conveniently studied in cotyledonary leaves. We monitored the protein, chlorophyll and electron transport activities in Cucumis sativus cv Poinsette cotyledonary leaves and observed that by 20th day, there was a 50%, 41% and 30-33% decline in the chlorophyll, protein and photosystem II activity respectively when compared to 6th day cotyledonary leaves taken as control. We investigated the changes in photosystem II activity (O2 evolution) as a function of light intensity. The photosystem II functional antenna decreased by 27% and the functional photosystem II units decreased by 30% in 20-day old cotyledonary leaf thylakoids. The herbicide [14C]-atrazine binding assay to monitor specific binding of the herbicide to the acceptor side of photosystem II reaction centre protein, D1, showed an increase in the affinity for atrazine towards D1 protein and decrease in the QB binding sites in 20th day leaf thylakoids when compared to 6th day leaf thylakoids. The western blot analysis also suggested a decrease in steady state levels of D1 protein in 20th day cotyledonary leaf thylakoids as compared to 6th day sample which is in agreement with [14C]-atrazine binding assay and light saturation kinetics.