Tendencies Affecting the Growth and Cultivation of Genus Spirulina: An Investigative Review on Current Trends

Spirulina, a kind of blue-green algae, is one of the Earth's oldest known forms of life. Spirulina grows best in very alkaline environments, although it may flourish across a wide variety of pH values. There are several techniques for growing Spirulina spp., ranging from open systems such as ponds and lakes, which are vulnerable to contamination by animals and extraterrestrial species, to closed systems such as photovoltaic reactors, which are not. Most contaminated toxins come from other toxic algae species that become mixed up during harvest, necessitating the study of spirulina production processes at home. Lighting, temperature, inoculation volume, stirring speed, dissolved particles, pH, water quality, and overall micronutrient richness are only a few of the environmental parameters influencing spirulina production. This review article covers the conditions required for spirulina cultivation, as well as a number of crucial factors that influence its growth and development while it is being grown. In addition, the article discusses harvesting processes, biomass measurement methods, the identification of dangerous algae, and the risk of contaminating algae as it grows on cultures. Spirulina's rising prospects as food for human consumption are a direct outcome of its prospective health and therapeutic advantages.

Trends and Technological Advancements in the Possible Food Applications of Spirulina and Their Health Benefits: A Review

Spirulina is a kind of blue-green algae (BGA) that is multicellular, filamentous, and prokaryotic. It is also known as a cyanobacterium. It is classified within the phylum known as blue-green algae. Despite the fact that it includes a high concentration of nutrients, such as proteins, vitamins, minerals, and fatty acids—in particular, the necessary omega-3 fatty acids and omega-6 fatty acids—the percentage of total fat and cholesterol that can be found in these algae is substantially lower when compared to other food sources. This is the case even if the percentage of total fat that can be found in these algae is also significantly lower. In addition to this, spirulina has a high concentration of bioactive compounds, such as phenols, phycocyanin pigment, and polysaccharides, which all take part in a number of biological activities, such as antioxidant and anti-inflammatory activity. As a result of this, spirulina has found its way into the formulation of a great number of medicinal foods, functional foods, and nutritional supplements. Therefore, this article makes an effort to shed light on spirulina, its nutritional value as a result of its chemical composition, and its applications to some food product formulations, such as dairy products, snacks, cookies, and pasta, that are necessary at an industrial level in the food industry all over the world. In addition, this article supports the idea of incorporating it into the food sector, both from a nutritional and health perspective, as it offers numerous advantages.

ANN-GA based biosorption of As(III) from water through chemo-tailored and iron impregnated fungal biofilter system

The iron impregnated fungal bio-filter (IIFB) discs of luffa sponge containing Phanerochaete chrysosporium mycelia have been used for the removal of As(III) from water. Two different forms of same biomass viz. free fungal biomass (FFB) and modified free fungal biomass (chemically modified and iron impregnated; CFB and IIFB) have been simultaneously investigated to compare the performance of immobilization, chemo-tailoring and iron impregnation for remediation of As(III). IIFB showed highest uptake capacity and percentage removal of As(III), 1.32 mg/g and 92.4% respectively among FFB, CFB and IIFB. Further, the application of RSM and ANN-GA based mathematical model showed a substantial increase in removal i.e. 99.2% of As(III) was filtered out from water at optimised conditions i.e. biomass dose 0.72 g/L, pH 7.31, temperature 42 °C, and initial As(III) concentration 1.1 mg/L. Isotherm, kinetic and thermodynamic studies proved that the process followed monolayer sorption pattern in spontaneous and endothermic way through pseudo-second order kinetic pathway. Continuous mode of As(III) removal in IIFB packed bed bioreactor, revealed increased removal of As(III) from 76.40 to 88.23% with increased column height from 5 to 25 cm whereas the removal decreased from 88.23 to 69.45% while increasing flow rate from 1.66 to 8.30 mL/min. Moreover, the IIFB discs was regenerated by using 10% NaOH as eluting agent and evaluated for As(III) removal for four sorption–desorption cycles, showing slight decrease of their efficiency by 1–2%. SEM–EDX, pHzpc, and FTIR analysis, revealed the involvement of hydroxyl and amino surface groups following a non-electrostatic legend exchange sorption mechanism during removal of As(III).

Recent trends and technological development in plasma as an emerging and promising technology for food biosystems

The rising need for wholesome, fresh, safe and “minimally-processed” foods has led to pioneering research activities in the emerging non-thermal technology of food processing. Cold plasma is such an innovative and promising technology that offers several potential applications in the food industry. It uses the highly reactive, energetic and charged gas molecules and species to decontaminate the food and package surfaces and preserve the foods without causing thermal damage to the nutritional and quality attributes of food. Cold plasma technology showed promising results about the inactivation of pathogens in the food industry without affecting the food quality. It is highly effective for surface decontamination of fruits and vegetables, but extensive research is required before its commercial utilization. Recent patents are focused on the applications of cold plasma in food processing and preservation. However, further studies are strongly needed to scale up this technology for future commercialization and understand plasma physics for getting better results and expand the applications and benefits. This review summarizes the emerging trends of cold plasma along with its recent applications in the food industry to extend shelf life and improve the quality of food. It also gives an overview of plasma generation and principles including mechanism of action. Further, the patents based on cold plasma technology have also been highlighted comprehensively for the first time.

Correlation between HRCT Findings of Symptomatic COVID-19 Patient with RT-PCR Test in a Tertiary Hospital of Bangladesh

The COVID-19 pandemic has turned into a global calamity and affected millions of lives around the world. Even though the vaccination efforts have started, they are yet to have an effective impact on the lower to middle-income countries. Early detection and isolation are still the best way to control the spread of the virus. The standard practice for detecting COVID-19 is the RT-PCR (Reverse Transcription Polymerase Chain Reaction) test but this test has a high probability of producing false-negative results plus lack of availability at all the time due to shortage of kit. Since COVID-19 is a respiratory disease affecting the lungs and the imaging patterns caused by COVID-19 can be observed in chest HRCT (High Resolution Computed Tomography) scans. As a result, HRCT can be used as an alternative diagnostic modality for any suspected cases of COVID-19. In this cross-sectional study was carried out in the Department of Radiology and Imaging, BSMMU, Dhaka, Bangladesh from May 12, 2020 to August 10, 2020. Chest HRCT scans of 284 suspected patients irrespective of age and sex who had done RT-PCR test either positive or negative test result having symptoms suggesting COVID pneumonia were enrolled in this study. Patients who had not done RT-PCR and who were not willing to do HRCT chest were excluded. According to the study, ground glass opacity is the most common feature and found in 89.44% of patients. The other predominant features were including consolidation, crazy paving, fibrotic density and vascular enlargement. The diagnostic performance of the CT scan was also evaluated using the RT-PCR test result as the gold standard and the sensitivity, specificity, and accuracy of the CT scan diagnosis were found to be 83.2%, 50% and 79.9% respectively. The severity of the five lung lobes has also been studied. The right middle lobe and the left upper lobe seemed to be in more severe condition for most of the patients compared to the other lung lobes.

Evaluating comparative β-glucan production aptitude of Saccharomyces cerevisiae, Aspergillus oryzae, Xanthomonas campestris, and Bacillus natto

β-glucan is a natural polysaccharide derivative composed of a group of glucose monomers with β-glycoside bonds that can be synthesized intra- or extra-cellular by various microorganisms such as yeasts, bacteria, and moulds. The study aimed to discover the potential of various microorganisms such as Saccharomyces cerevisiae, Aspergillus oryzae, Xanthomonas campestris, and Bacillus natto in producing β-glucan. The experimental method used and the data were analyzed descriptively. The four microorganisms above were cultured under a submerged state in Yeast glucose (YG) broth for 120 h at 30 °C with 200 rpm agitation. During the growth, several parameters were examined including total population by optical density, the pH, and glucose contents of growth media. β-glucan was extracted using acid-alkaline methods from the growth media then the weight was measured. The results showed that S. cerevisiae, A. oryzae X. campestris, and B. natto were prospective for β-glucans production in submerged fermentation up to 120 h. The highest β-glucans yield was shown by B. natto (20.38%) with the β-glucans mass of 1.345 ± 0.08 mg and globular diameter of 600 μm. The highest β-glucan mass was achieved by A. oryzae of 82.5 ± 0.03 mg with the total population in optical density of 0.1246, a final glucose level of 769 ppm, the pH of 6.67, and yield of 13.97% with a globular diameter of 1400 μm.

Supercritical fluid extraction (SCFE) as green extraction technology for high-value metabolites of algae, its potential trends in food and human health

Application of high-value algal metabolites (HVAMs) in cosmetics, additives, pigments, foods and medicines are very important. These HVAMs can be obtained from the cultivation of micro- and macro-algae. These metabolites can benefit human and animal health in a physiological and nutritional manner. However, because of conventional extraction methods and their energy and the use of pollutant solvents, the availability of HVAMs from algae remains insufficient. Receiving their sustainability and environmental benefits have recently made green extraction technologies for HVAM extractions more desirable. But very little information is available about the technology of green extraction of algae from these HVAM. This review, therefore, highlights the supercritical fluid extraction (SCFE) as principal green extraction technologyand theirideal parameters for extracting HVAMs. In first, general information is provided concerning the HVAMs and their components of macro and micro origin. The review also includes a description of SCFE technology's properties, instrumentation operation, solvents used, and the merits and demerits. Moreover, there are several HVAMs associated with their numerous high-level biological activities which include high-level antioxidant, anti-inflammatory, anticancer and antimicrobial activity and have potential health-beneficial effects in humans since they are all HVAMs, such as foods and nutraceuticals. Finally, it provides future insights, obstacles, and suggestions for selecting the right technologies for extraction.

Curcumin Extraction, Isolation, Quantification and Its Application in Functional Foods: A Review With a Focus on Immune Enhancement Activities and COVID-19

An entirely unknown species of coronavirus (COVID-19) outbreak occurred in December 2019. COVID-19 has already affected more than 180 million people causing ~3.91 million deaths globally till the end of June 2021. During this emergency, the food nutraceuticals can be a potential therapeutic candidate. Curcumin is the natural and safe bioactive compound of the turmeric (Curcuma longa L.) plant and is known to possess potent anti-microbial and immuno-modulatory properties. This review paper covers the various extraction and quantification techniques of curcumin and its usage to produce functional food. The potential of curcumin in boosting the immune system has also been explored. The review will help develop insight and new knowledge about curcumin's role as an immune-booster and therapeutic agent against COVID-19. The manuscript will also encourage and assist the scientists and researchers who have an association with drug development, pharmacology, functional foods, and nutraceuticals to develop curcumin-based formulations.

Unmasking the Many Faces of Giloy (Tinospora cordifolia L.): A Fresh Look on its Phytochemical and Medicinal Properties

BACKGROUND

Plants have been used to treat health disorders and prevent diseases since antiquity in all civilizations including the Indian and Chinse. Giloy (Tinospora cordifolia L.) is one of the most important medicinal plants in Indian folk medicine and is commonly known as the "Heart-leaved Moonseed" or "Guduchi". Giloy is a perennial shrubby creeper of the Menispermaceae family. It is native to the tropical areas of India, Sri Lanka, Myanmar, Sothern Eastern Asia, Africa, and Australia. It attracted attention in the last few decades because its roots, stems, and leaves are used in folk medicine treating several disorders.

METHODS

To reveal its potential, we reviewed the literature on this plant over the last five decades using several search engines.

RESULTS

Giloy is recommended in diabetes, stomachache, jaundice, urinary problems, skin ailments, and prolonged diarrhea and dysentery. The medicinal properties of T. cordifolia extracts were attributed to its phytochemical content including steroids, alkaloids, diterpenoid lactones, and glycosides.

CONCLUSION

In this review, we summarized the phytochemical content of T. cordifolia and its medicinal properties with special emphasis on its antioxidant, anti-inflammatory, and cytotoxic activities. We aimed to provide natural product researchers with a full picture of the potential applications of this plant in the development of food additives and nutraceuticals.

Mexican Oregano (Lippia graveolens Kunth) as Source of Bioactive Compounds: A Review

Lippia graveolens is a traditional crop and a rich source of bioactive compounds with various properties (e.g., antioxidant, anti-inflammatory, antifungal, UV defense, anti-glycemic, and cytotoxicity) that is primarily cultivated for essential oil recovery. The isolated bioactive compounds could be useful as additives in the functional food, nutraceuticals, cosmetics, and pharmaceutical industries. Carvacrol, thymol, β-caryophyllene, and p-cymene are terpene compounds contained in oregano essential oil (OEO); flavonoids such as quercetin O-hexoside, pinocembrin, and galangin are flavonoids found in oregano extracts. Furthermore, thermoresistant compounds that remain in the plant matrix following a thermal process can be priced in terms of the circular economy. By using better and more selective extraction conditions, the bioactive compounds present in Mexican oregano can be studied as potential inhibitors of COVID-19. Also, research on extraction technologies should continue to ensure a higher quality of bioactive compounds while preventing an undesired chemical shift (e.g., hydrolysis). The oregano fractions can be used in the food, health, and agricultural industries.

Bilateral Renal Angiomyolipoma with Hidden Tuberous Sclerosis Complex: A Case Report

Angiomyolipomas (AML) are benign tumor of kidney also referred as renal hamartoma composed of varying amounts of mature adipose tissue, smooth muscle, and blood vessels. It is seen in two distinct clinical forms, a sporadic (isolated) form and 55-80% seen in association with Tuberous sclerosis complex (TSC). If the lesion grows to a large size, a series of clinical manifestations and serious complications may occur. Here we present a case of 26 years lady who presented in the Department Radiology & Imaging of Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh with chief complaints of bilateral loin pain and occasional hematuria for 2 months. Ultrasound abdomen and contrast enhanced computed tomography shows bilateral renal angiomyolipoma (left>right). In order to look for tuberous sclerosis features, we followed her with plain computed tomography of head which shows subependymal calcifications.

Encapsulated Food Products as a Strategy to Strengthen Immunity Against COVID-19

In December 2019, the severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2)-a novel coronavirus was identified which was quickly distributed to more than 100 countries around the world. There are currently no approved treatments available but only a few preventive measures are available. Among them, maintaining strong immunity through the intake of functional foods is a sustainable solution to resist the virus attack. For this, bioactive compounds (BACs) are delivered safely inside the body through encapsulated food items. Encapsulated food products have benefits such as high stability and bioavailability, sustained release of functional compounds; inhibit the undesired interaction, and high antimicrobial and antioxidant activity. Several BACs such as ω-3 fatty acid, curcumin, vitamins, essential oils, antimicrobials, and probiotic bacteria can be encapsulated which exhibit immunological activity through different mechanisms. These encapsulated compounds can be recommended for use by various researchers, scientists, and industrial peoples to develop functional foods that can improve immunity to withstand the coronavirus disease 2019 (COVID-19) outbreak in the future. Encapsulated BACs, upon incorporation into food, offer increased functionality and facilitate their potential use as an immunity booster. This review paper aims to target various encapsulated food products and their role in improving the immunity system. The bioactive components like antioxidants, minerals, vitamins, polyphenols, omega (ω)-3 fatty acids, lycopene, probiotics, etc. which boost the immunity and may be a potential measure to prevent COVID-19 outbreak were comprehensively discussed. This article also highlights the potential mechanisms; a BAC undergoes, to improve the immune system.

Isolation, modification, and characterization of rice starch with emphasis on functional properties and industrial application: a review

Starch is one of the organic compounds after cellulose found most abundantly in nature. Starch significantly varies in their different properties like physical, chemical, thermal, morphological and functional. Therefore, starch is modified to increase the beneficial characteristics and remove the shortcomings issues of native starches. The modification methods can change the extremely flexible polymer of starch with their modified physical and chemical properties. These altered structural attributes are of great technological values which have a wide industrial potential in food and non-food. Among them, the production of novel starches is mainly one that evolves with new value-added and functional properties is on high industrial demands. This paper provides an overview of the rice starch components and their effect on the technological and physicochemical properties of obtained starch. Besides, the tuned techno-functional properties of the modified starches through chemical modification means are highlighted.HighlightsNative and modified starches varies largely in physicochemical and functional traits.Modified physical and chemical properties of starch can change the extremely flexible polymer of starch.Techno-functional properties of the modified starches through chemical modification means are highlighted.Dual modification improves the starch functionality and increases the industrial applications.Production of novel starches is on high industrial demands because it mainly evolves with new value added and functional properties.

Identifying Intruders in MANET

Mobile ad hoc networks are characterized by wireless medium used for communication, frequent change of topology, and non-availability of centralized control for authentication. Out of all the attributes, communication through open air poses the biggest threat to security. Absence of security implementations by the routing protocols gives opening for intrusion to malicious nodes which then operate various attacks to hinder the normal communication. Solution suggested modifies vastly used AODV protocol to exploit the unused reserved bits of RREP message for identifying the malicious nodes in the MANET. Proposed algorithm finds the neighbors of the destination through RREQ messages, identifies vindictive neighbors providing contrived DSNs of the destination.

Exploring the physicochemical and cooking properties of some Indian aromatic and non-aromatic rice (Oryza sativa L.) cultivars

The objective of the present investigation was to assess the physicochemical and cooking properties of Indian rice cultivars grown locally by farmers. Results reported the highest hulling (80.82%) and milling (75.47%) in cultivar Badshah Bhog (BSB) while the head rice out-turns were maximum in Govind Bhog (GVB) (58.22%) and broken rice was minimum in Khushboo (KSB) (5.15%). The kernel length (6.16-7.88 mm) of KSB, Kalanamak (KLN), Sarbati (SRB) and Todal (TDL) cultivars were nearly alike to the preferred minimum acceptable standard of Basmati rice (6.6mm). The kernel and volume elongation ratio was highest in Swetganga (STG) (2.07) and TDL (4.07), respectively whereas the amylose content was highest (>20%) in all aromatic cultivars and categorized the intermediate type than evolved aromatic rice KLN and nonaromatic cultivars (SRB and TDL). Further, the studied rice cultivars had grain quality characteristics similar to the minimum acceptable standards for the breeding of basmati type cultivars which may be employed for breeding purposes and can be graded as export quality rice possessing distinct nutritional values at the global level.

Candidatus Actinochlamydia pangasiae sp. nov. (Chlamydiales, Actinochlamydiaceae), a bacterium associated with epitheliocystis in Pangasianodon hypophthalmus

Chlamydial infections are recognised as causative agent of epitheliocystis, reported from over 90 fish species. In the present study, the farmed striped catfish Pangasianodon hypophthalmus (14-15 cm, 70-90 g) with a history of cumulative mortality of about 23% during June and July 2015, were brought to the laboratory. The histopathological examination of gills from the affected fish revealed presence of granular basophilic intracellular inclusions, mostly at the base of the interlamellar region and in gill filaments. A concurrent infection with Trichodina spp., Ichthyobodo spp. and Dactylogyrus spp. was observed in the gills. The presence of chlamydial DNA in the gills of affected fish was confirmed by amplification and sequencing of 16S rRNA gene. BLAST-n analysis of these amplicons revealed maximum similarity (96%) with Candidatus Actinochlamydia clariae. On the basis of phylogenetic analysis, it was inferred that the epitheliocystis agents from striped catfish were novel and belonged to the taxon Ca. Actinochlamydia. It is proposed that epitheliocystis agents from striped catfish will be named as Ca. Actinochlamydia pangasiae. The 16S rRNA gene amplicons from novel chlamydiae were labelled and linked to inclusions by in situ hybridisation. This is the first report of epitheliocystis from India in a new fish host P. hypophthalmus.

Metastatic calcification of floor of the mouth secondary to chronic renal failure-report of a rare case with atypical presentation

Soft-tissue calcification is always pathological. Metastatic calcification is calcification of soft tissues owing to hyperphosphataemia with or without hypercalcaemia. Metastatic calcification of oral cavity is extremely rare. A case report of metastatic calcification of the floor of the mouth with atypical radiologic and clinical picture is presented here along with a review of earlier reports. A chance finding of the granular oral mucosa on palpation led to a radiographic examination revealing granular calcifications of the floor of the mouth. Blood chemistry and hormone analysis revealed chronic renal failure and hyperparathyroidism. A diagnosis of metastatic calcification secondary to renal failure was made and the treatment was aimed at correcting the renal failure without any intervention for the asymptomatic calcifications. Key differences between the present case and other cases reported in the literature are outlined.

[Identification of hypervariable regions within the 16S-23S rRNA intergenic spacer region of Flavobacterium columnare and its application in assigning genomovar group to an individual strain]

Flavobacterium columnare is an important bacterial pathogen of fish with wide ge- netic variability within species. This intraspecies diversity has been termed as genomovars and genomovar groups on the basis of Restriction Fragment Length Polymorphisms of 16S rDNA and 16S-23S rDNA Intergenic Spacer Region (ISR), respectively. In this study, we demonstrate the source of genetic heterogeneity in the F. columnare by sequence analysis of ISR. Length of ISR sequences of different genomovars varied from 553 to 592 nucleotides, while the similarity among sequences ranged from 76.1 to 92.6%. A common ISR structure with tRNAAa and tRNAne embedded within the sequence was identified in all the genomovars ofF. columnare. The results show that strains of F. columnare can be categorized into five genomovar groups based on the heterogeneity in the ISR sequences. Of these, strains belonging to Genomovar I and II can be sub-divided into two groups each; while strains of Genomovar III belonged to one group. Sequence similarity between genomovar groups was lower for ISR (76.1-92.6%) as compared to 16S rDNA (96.1-99.4%) indicating its ability to resolve closely related groups within the genomovars of F. columnare. The main source of variation between genomovar groups is the presence of three hyper variable regions (V1, V2 & V3) in the ISR Of the three, V3 was found to be the most heterogeneous region and was found to be useful in assigning genomovar group to an individual strain of F. columnare.

Kocuria flava induced growth and chromium accumulation in Cicer arietinum L

In the present investigation a chromate tolerant rhizobacterium Kocuria flava was isolated and inoculated to the Cicer arietinum L to evaluate its effects on growth and chromium accumulation upon exposure of different concentration of chromium (1-10 microg ml(-1)) as Cr (VI) for 24 d. K. flava inoculated plant of C. arietinum demonstrated luxuriant growth as compared to non inoculated plant at respective concentration of Cr (VI). K. flava found to ameliorate chromium induced phytotoxicity in terms of chlorophylls, carotenoid and protein contents and thus helps the plant in acquiring higher biomass with high chromium concentration. After 24 d, maximum concentration of chromium recorded in root of C. arietinum (4892.39 microg g(-1) dw) inoculated with K. flava as compared to non inoculated plant (1762.22 microg g(-1) dw) upon exposure of 5 microg ml(-1) Cr (VI). Therefore, application of C. arietinum in association with K. flava could be more efficient in decontamination of chromium polluted site. Moreover, K. flava may be used as a bioresource for developing microbes assisted phytoremediation system due to its compatibility.

Comparison of short-course multidrug treatment with standard therapy for visceral leishmaniasis in India: an open-label, non-inferiority, randomised controlled trial

BACKGROUND

Improved treatment approaches are needed for visceral leishmaniasis. We assessed the efficacy and safety of three potential short-course combination treatments compared with the standard monotherapy in India.

METHODS

Standard treatment (1 mg/kg amphotericin B infusion on alternate days for 30 days, total dose 15 mg/kg) was compared with three drug combinations (single injection of 5 mg/kg liposomal amphotericin B and 7-day 50 mg oral miltefosine or single 10-day 11 mg/kg intramuscular paromomycin; or 10 days each of miltefosine and paromomycin) in an open-label, parallel-group, non-inferiority, randomised controlled trial in two hospital sites in Bihar, India. Patients aged 5-60 years with parasitologically confirmed visceral leishmaniasis were randomly assigned one of the four treatments by the trial statistician by use of a computer-generated list. Clinical assessments were done at the end of treatment (15 days on combination treatment; 31 days for standard treatment) and after 45 days and 6 months. The primary endpoint was definitive cure (defined as no sign or symptom of visceral leishmaniasis and parasitologically cured to the last follow-up). Analyses were done both by intention to treat and per protocol. This trial is registered with ClinicalTrials.gov, number NCT00696969.

FINDINGS

Between June, 2008, and July, 2009, 634 patients were assigned amphotericin B (n=157), liposomal amphotericin B with miltefosine (n=160) or paromomycin (n=158), or miltefosine and paromomycin (n=159). 618 patients were in the per-protocol population. There were two relapses in each group. The numbers with definitive cure at 6 months for the intention-to-treat population were 146 (cure rate 93·0%; CI 87·5-96·3) for amphotericin B, 156 (97·5%; 93·3-99·2) for liposomal amphotericin B and miltefosine, 154 (97·5%; 93·24-99·2) for liposomal amphotericin B and paromomycin, and 157 (98·7%; 95·1-99·8) for miltefosine and paromomycin. All combinations were non-inferior to the standard treatment, in both the intention-to-treat and per-protocol populations. Patients in the combination groups had fewer adverse events than did those assigned standard treatment.

INTERPRETATION

Combination treatments for visceral leishmaniasis are efficacious and safe, and decrease the duration of therapy, thereby encouraging adherence and reducing emergence of drug-resistant parasites.

FUNDING

Drugs for Neglected Diseases initiative and the Indian Council of Medical Research.

Derivation and characterization of embryonic stem-like cells of Indian major carp Catla catla

Embryonic stem (ES)-like cells were derived from mid-blastula stage embryos of a freshwater fish, catla Catla catla, under feeder-free condition and designated as CCES cells. The conditioned media was optimized with 10% foetal bovine serum (FBS), fish embryo extract (FEE) having 100 µg ml(-1) protein concentration, 15 ng ml(-1) basic fibroblast growth factor (bFGF) and basic media containing Leibovitz-15, DMEM with 4·5 g l(-1) glucose and Ham's F12 (LDF) in 2:1:1 ratio using a primary culture of CCES cells. Cells attached to gelatin-coated plates after 24 h of seeding and ES-like colonies were obtained at day 5 onwards. A stable cell culture was obtained after passage 10 and further maintained up to passage 44. These cells were characterized by their typical morphology, high alkaline phosphatase activity, positive expression of cell-surface antigen SSEA-1, transcription factor Oct4, germ cell marker vasa and consistent karyotype up to extended periods. The undifferentiated state was confirmed by their ability to form embryoid bodies and their differentiation potential.

Ensuring comparability of benzene exposure estimates across three nested case-control studies in the petroleum industry in support of a pooled epidemiological analysis

BACKGROUND

Three case-control studies each nested within a cohort of petroleum workers assessed exposure to benzene in relation to risk of haematopoietic cancers. These studies have each been updated and the cases will be pooled to derive a more powerful study. The benzene exposure of new leukemia cases and controls was estimated in accordance with each respective study's original methods. An essential component of the process of pooling the data was comparison and rationalisation of the exposure estimates to ensure accuracy and consistency of approach. This paper describes this process and presents comparative estimates before and after appropriate revision took place. The original petroleum industry studies, in Canada, the UK and Australia, were conducted at different points in time by different study teams, but the industry used similar technology in similar eras in each of these countries.

METHODS

A job history for each subject giving job title, dates of starting and leaving the job and location of work, was assembled. For each job or task, the average benzene exposure (Base Estimate (BE) in ppm) was derived from measurements collected at applicable worksites. Estimates of exposure intensity (workplace exposure estimates (WE)) were then calculated for each line of work history by adjusting the BEs for site- and era-specific exposure-related variables such as loading technology and percentage benzene in the product. To ensure that the exposure estimates were comparable among the studies, the WEs were allocated to generic Job Categories, e.g. Tanker Driver (by technology used e.g. bottom loading), Motor Mechanic. The WEs were stratified into eras, reflecting technological changes in the industry. The arithmetic mean (AM), geometric mean (GM) and range of the stratified WEs were calculated, by study, for each generic Job Category. These were then compared. The AMs of the WEs were regarded as substantially similar if they were within 20% in all three studies in one era or for at least two studies in two eras. If the AM of the WE group differed by more than 20%, the data were examined to see whether the difference was justified by differences in local exposure conditions, such as an enclosure versus open work area. Estimates were adjusted in the absence of justification for the difference.

RESULTS

Reconciliation of differences resulted in changes to a small number of underlying BEs, particularly the background values, also the BEs attributed to some individuals and changes to the allocation of jobs between Job Categories. Although the studies covered some differing sectors of the industry and different time periods, for 22 Job Categories there was sufficient overlap, particularly in the downstream distribution sector, to make comparisons possible. After adjustment 12 Job Categories were judged to be similar and 10 were judged to be justifiably different. Job-based peak and skin exposure estimates were applied in a uniform way across the studies and a single approach to scoring the certainty of the exposure estimates was identified.

CONCLUSIONS

The revised exposure estimates will be used in the pooled analysis to examine the risk of haematopoietic cancers and benzene exposure. This exercise provided an important quality control check on the exposure estimates and identified similarly exposed Job Categories that could be grouped for risk assessment analyses.

Ultrasound guided percutaneous nephrostomy for obstructive uropathy in benign and malignant diseases

OBJECTIVE

Analyze the success rate, complications and overall benefit of ultrasound guided percutaneous nephrostomy (PCN) for the relief of obstructive uropathy in benign and malignant diseases.

MATERIALS AND METHODS

PCN was performed in 50 kidneys of 32 patients. It was performed in emergency rooms totally under ultrasound guidance by general surgeons. Seldinger technique was used in all cases. Changes in renal function after the procedure were analyzed using paired t-test.

RESULTS

The procedure was successfully completed in 42 out of 50 kidneys (84%). There has been no major complication and 28% minor complications. The renal function improved significantly when PCN was performed for benign conditions (mean creatinine 3.52 mg/dL before and 2.18 mg/dL after PCN), however in malignancy there has been no significant improvement in renal function (before PCN mean creatinine 6.39 mg/dL and after PCN 5.41 mg/dL).

CONCLUSION

We conclude that PCN can be effectively performed under ultrasound guidance and should be the initial procedure in acutely obstructed kidneys with pyonephrosis and poor renal function. In malignant cases, however, improvement in renal function is possible only if the procedure is carried out at an early stage.

Quantitative histological features and ultrastructure of opercula of human teeth showing normal and delayed eruption

BACKGROUND

Failure of eruption of human permanent molars has been attributed to opercular lesions, although comparisons with specimens from normally erupting teeth are scarce. The aim of this study was to quantitatively analyse opercula associated with normal and delayed tooth eruption.

METHOD

Twenty opercula covering permanent molars delayed in eruption were obtained from 13 patients aged 7.3-18.1 years. Six opercula from normally erupting molars of five 7.3-17.5-year-old subjects served as controls. Specimens were analysed light and electron microscopically and morphometrically.

RESULTS

In addition to features recognized previously, prominent numbers of nerves, high endothelial-like venules and mast cells were observed. Ultrastructurally, large multinucleated cells did not reveal cell boundaries running between the nuclei, and mast cells seemed belonging to the MC(TC)-type. None of the features differed significantly between opercula from cases of delayed and normal tooth eruption.

CONCLUSIONS

Disturbances of tooth eruption that are attributed to opercular lesions may represent retentions resulting from the failure of the eruption mechanism, rather than impactions because of a physical barrier.

A cohort study of mortality among Ontario pipe trades workers

AIMS

To study mortality in a cohort of members of the United Association of Journeymen and Apprentices of the Plumbing and Pipe Fitting Industry of the United States and Canada and to compare results with two previous proportional mortality studies.

METHODS

A cohort of 25,285 workers who entered the trade after 1949 was assembled from records of the international head office. Mortality was ascertained by linkage to the Canadian Mortality Registry at Statistics Canada. Standardised mortality ratios were computed using Ontario general population mortality rates as the reference.

RESULTS

There were significant increases in lung cancer mortality rates (SMR 1.27; 95% CI 1.13 to 1.42). Increased lung cancer risk was observed among plumbers, pipefitters, and sprinkler fitters. Increased risk was observed among workers joining the Union as late as the 1970s. A random effects meta-analysis of this study and the two PMR studies found significant increases in oesophageal (RR 1.24; 95% CI 1.00 to 1.53), lung (RR 1.31; 95% CI 1.19 to 1.44), and haematological/lymphatic (RR 1.21; 95% CI 1.08 to 1.35) malignancies.

CONCLUSIONS

The mortality pattern is consistent with the effects of occupational exposure to asbestos. Increased risk due to other respiratory carcinogens such as welding fume cannot be excluded. There are substantial amounts of asbestos in place in industrial and commercial environments. The education and training of workers to protect themselves against inhalation hazards will be necessary well into the future.

Measurement of beryllium in lung tissue of a chronic beryllium disease case and cases with sarcoidosis

BACKGROUND

The clinical features of chronic beryllium disease (CBD) are similar to many other chronic lung diseases. In particular, it may be difficult to distinguish it from pulmonary sarcoidosis since the two conditions may be very alike in clinical, pathological and radiological features. Aim To determine if the amount of beryllium found in the lungs could be used to differentiate CBD from sarcoidosis and controls.

METHODS

Analyses for beryllium in the autopsied lung tissues of 29 cases and controls were carried out. The cases included one CBD, three confirmed sarcoidosis and 25 controls. Blocks of formalin-fixed tissues were analysed by an atomic absorption spectrophotometer equipped with a graphite furnace. A method for analysis of beryllium in air was modified to permit tissue analysis.

RESULTS

The CBD case had a much higher average beryllium level, but some individual results were similar to controls and patients with sarcoidosis.

CONCLUSION

The CBD case had beryllium levels within the range of values reported in the literature. The differentiation between CBD and sarcoidosis could not be made with reasonable assurance based only on the analytic result. Occupational history is very important in making a diagnosis of CBD, along with the analysis of tissues. Tissue analysis helped confirm the diagnosis of compensatable CBD in this particular case.

Primary cutaneous amoebiasis: case report with review of the literature

BACKGROUND

Primary cutaneous amoebiasis is a rare clinical entity. The lesions can be successfully treated if suspected and correctly diagnosed. We report an interesting case with review of the literature.

METHODS

A 25-year-old man presenting with primary cutaneous amoebiasis with extensive involvement of the anterior abdominal wall is described. Correct diagnosis eluded us for 2 years. Clinical suspicion and a simple bedside test (wet drop preparation examination) were sufficient to diagnose the lesion. Successful treatment was achieved with oral Metronidazole followed by split skin grafting. Only six cases of primary cutaneous amoebiasis could be traced in the literature.

CONCLUSIONS

Primary cutaneous amoebiasis is extremely rare. Diagnosis is usually not suspected because of its rarity. Cutaneous amoebiasis responds readily to proper treatment, yet, if unrecognized and neglected, produces significant morbidity and may be fatal.

A comparison of international silica (alpha-quartz) calibration standards by Fourier transform-infrared spectrophotometry

Seven international silica (alpha-quartz) standards were examined for relative purity to the US National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) 1878 Respirable alpha-quartz by Fourier Transform-Infrared Spectrophotometry (FT-IR). The standards examined have been used in North America, the UK, Australia and Germany. The 189 samples analyzed included NIST-SRM 1878, Min-U-Sil 5, Ottawa Silica Sand, Sikron F-600, A9950 (AUST 1), DQ12-Robock, DQ12-Bergbau. Size distributions of the standards were determined by Coulter Counter to be broadly similar with equivalent spherical volume median diameter ranging between 1.2 and 3 microm. The results showed the standards to differ by as much as 30% in relative purity. Consequently, an internationally agreed upon calibration standard is urgently needed. Min-U-Sil 5 based NIST-SRM 1878 or Sikron F-600 are the two most likely candidates. Any agreed standard must have a well characterized size distribution and closely match the respirable dust criteria. It should also be studied by both infrared spectrophotometry and X-ray diffraction techniques.

A laboratory evaluation of the accuracy and precision of the photovac snapshot portable gas chromatograph and the Dräger Chip Measurement System monitor for benzene in air measurements

A laboratory evaluation of the accuracy and precision of two field instruments, the Photovac Snapshot Gas Chromatograph and the Dräger Chip Measurement System (CMS) Monitor, both capable of specific determination of benzene, was carried out. The evaluation was based on the generation of a test atmosphere of known concentration of benzene in a stainless steel calibration chamber and simultaneous sampling of the test atmosphere by each instrument. At the same time, the chamber atmosphere was continuously monitored by one or two data logging photoionization detector (PID) hydrocarbon analysers. A series of six, 10-minute charcoal tube air samples of the test atmosphere was also collected over the 1-hour run and analyzed by gas chromatography. Nine different concentrations ranging from 0.25 ppm to 8 ppm were used. Accuracy was evaluated using National Institute for Occupational Safety and Health (NIOSH) criteria. The Photovac GC consistently met the NIOSH recommended accuracy criteria of +/- 25 percent at or below 1 ppm of benzene, whereas the Drager CMS results generally fell slightly outside this criteria. Compared against less stringent accuracy criteria of +/- 35 percent, all Photovac GC results were acceptable but about 40 percent of Drager CMS results were not. The precision of Photovac GC (CV +/- 10%) is better than Drager CMS (CV = +/- 20% to 40%). Both instruments are, however, good field instruments provided their limitations are taken into account in their use.

Exposure estimation in the presence of nondetectable values: another look

A common problem faced by industrial hygienists is the selection of a valid way of dealing with those samples reported to contain nondetectable values of the contaminant. In 1990, Hornung and Reed compared a maximum likelihood estimation (MLE) statistical method and two methods involving the limit of detection, L. The MLE method was shown to produce unbiased estimates of both the mean and standard deviation under a variety of conditions. That method, however, was complicated, requiring difficult mathematical calculations. Two simpler alternatives involved the substitution of L/2 or L/square root of 2 for each nondetectable value. The L/square root of 2 method was recommended when the data were not highly skewed. Although the MLE method produces the best estimates of the mean and standard deviation of an industrial hygiene data set containing values below the detection limit, it was not practical to recommend this method in 1990. However, with advances in desktop computing in the past decade the MLE method is now easily implemented in commonly available spreadsheet software. This article demonstrates how this method may be implemented using spreadsheet software.

Benzene and total hydrocarbons exposures in the downstream petroleum industries

A review of studies, including both articles published in peer-reviewed journals and reports that were not peer reviewed, regarding occupational exposure to benzene and total hydrocarbons in the downstream petroleum industry operations was performed. The objective was to provide a broad estimate of exposures by compiling exposure data according to the following categories: refinery, pipeline, marine, rail, bulk terminals and trucks, service stations, underground storage tanks, tank cleaning, and site remediations. The data in each category was divided into personal occupational long-term and short-term samples. The summarized data offers valuable assistance to hygienists by providing them with an estimate and range of exposures. The traditional 8-hour time-weighted average (TWA) exposure and the 40-hour workweek do not generally coincide with exposure periods applicable to workers in marine, pipeline, railcar, and trucking operations. They are more comparable with short-term exposure or task-based exposure assessments. The marine sector has a large number of high exposures. Although relatively few workers are exposed, their exposures to benzene and total hydrocarbons are sometimes an order of magnitude higher than the respective exposure limits. It is recommended that in the future, it would be preferable to do more task-based exposure assessments and fewer traditional TWA long-term exposure assessments within the various sectors of the downstream petroleum industry.