Influence of enzyme activity on domestic wastewater amelioration in a hybrid subsurface flow constructed wetland

Wastewater treatment in a constructed wetland is achieved by the presence of plant species, the metabolism of microorganisms, and the enzyme activities. Three small-scale hybrid subsurface flow constructed wetlands (HSFCWs) planted with Arundo donax and one unplanted HSFCW were constructed near a water resource recovery facility at Guru Gobind Singh Indraprastha University. The purpose of the study was to determine the correlation between soil enzymatic activities and the removal of contaminants from domestic wastewater. Enzyme activity of phosphatase, protease, urease, and cellulase increased with an increase in temperature. A strong correlation between enzyme activities and TKN and surfactant removal was observed, whereas moderate correlation was observed with phosphate in planted HSFCW during the study. The correlation between COD removal and enzyme activities was low to moderate. In unplanted HSFCW, the correlation between enzyme activities and COD removal was negative, negligible to moderate to strong in the case of TKN, low to moderate in the case of phosphate, and negligible to low in the case of surfactants. The increased removal efficiency of the planted system compared with that of the unplanted system indicated a positive impact on enzyme activities with the growth of plants and their roots. PRACTITIONER POINTS: Protease, urease, and cellulase activities: Planted HSFCW exhibited higher protease, urease, and cellulase activities than unplanted, signifying enhanced breakdown. July displayed maximum enzyme activities, correlating with heightened biological breakdown in both systems. Fluctuations in enzyme activities reflected seasonal changes, influencing nutrient degradation rates. Planted HSFCW consistently showed higher enzymatic activities across protease, urease, and cellulase than unplanted.

Network interactions with functional roles and evolutionary relationships for BURP domain-containing proteins in chickpea and model species

The functional significance and evolutionary relationships of BURP domain-containing genes unique to plants is of interest. Network analysis reveals different associations of BURP proteins with other proteins and functional terms, throwing light on their involvement in various biological processes and pathways. The gene expression data reveals that BURP genes are affected by salinity stress, reflecting diverse expression patterns in roots and shoots.

Designed and validated novel allele-specific primer to differentiate Kernel Row Number (KRN) in tropical field corn

BACKGROUND

Kernel row number (KRN) is an important yield component trait with a direct impact on the productivity of maize. The variability in KRN is influenced by the inflorescence meristem size, which is determined by the CLAVATA-WUSCHEL pathway. A CLAVATA receptor-like protein, encoded by the FASCIATED EAR2 (fea2gene), enhances the growth of inflorescence meristem and is thus involved in the determination of KRN. The amplicon sequencing-based method was employed to dissect the allelic variation of the fea2 gene in tropical field corn.

METHODOLOGY/PRINCIPAL FINDING

Amplicon-based sequencing of AI 535 (Low KRN) and AI 536 (High KRN) was undertaken for the gene fea 2 gene that codes for KRN in maize. Upon multiple sequence alignment of both sequences, A to T transversion at the 1311 position was noticed between Low KRN and High KRN genotypes resulting in different allelic forms of a fea2 gene in tropical maize. An allele-specific primer 1311 fea2.1 was designed and validated that can differentiate High and Low KRN genotypes.

CONCLUSION/SIGNIFICANCE

Maize has high variability for KRN and is exemplified by the wide values ranging from 8-26 KRN in the maize germpalsm. The sequence-based approach of SNP detection through the use of a specific primer facilitated the detection of variation present in the target trait. This makes it possible to capture these variations in the early generation. In the study, the PCR-based differentiation method described for the identification of desirable high KRN genotypes would augment the breeding programs for improving the productivity of field corn.

Draft genome sequencing and secretome profiling of Sclerotinia sclerotiorum revealed effector repertoire diversity and allied broad-host range necrotrophy

White mold commonly known as Sclerotinia sclerotiorum causes stem rot disease and has emerged as one of the major fungal pathogens of oilseed Brassica across the world. In the present study, consistently virulent S. sclerotiorum isolate "ESR-01" was sequenced and an assembly size of ~ 41 Mb with 328 scaffolds having N50 of 447,128 was obtained. Additionally, 27,450 single nucleotide polymorphisms (SNPs) were identified from 155 scaffolds against S. sclerotiorum 1980 isolate, with an average SNP density of ~ 1.5 per kb genome. 667 repetitive elements were identified and approximately comprised 7% of the total annotated genes. The DDE_1 with 454 in numbers was found to be the most abundant and accounts for 68% of the total predicted repetitive elements. In total, 3844 simple sequence repeats are identified in the 328 scaffolds. A total of 9469 protein-coding genes were predicted from the whole genome assembly with an average gene length of 1587 bp and their distribution as 230.95 genes per Mb in the genome. Out of 9469 predicted protein-coding genes, 529 genes were observed encoding the CAZymes (Carbohydrate-Active enzymes) capable of degradation of the complex polysaccharides. Glycosyltransferase (GT) families were most abundant (49.71%) among the predicted CAZymes and GT2 (23%), GT4 (20%), and glycoside hydrolase (GH) 23% with GH18 (11%) were the prominent cell wall degrading enzyme families in the ESR-01 secretome. Besides this, 156 genes essential for the pathogen-host interactions were also identified. The effector analysis in the whole genome proteomics dataset revealed a total of 57 effector candidates (ECs) and 27 of them were having their analogs whereas the remaining 30 were novel ones. Eleven selected ECs were validated experimentally by analyzing the expression profile of the ESR-01 isolate of S. sclerotiorum. Together, the present investigation offers a better understanding of the S. sclerotiorum genome, secretome, and its effector repertoire which will help in refining the present knowledge on S. sclerotiorum-Brassica interactions and necrotrophic lifestyle of the phytopathogen in general.

Strategies for utilization of crop wild relatives in plant breeding programs

Crop wild relatives (CWRs) are weedy and wild relatives of the domesticated and cultivated crops, which usually occur and are maintained in natural forms in their centres of origin. These include the ancestors or progenitors of all cultivated species and comprise rich sources of diversity for many important traits useful in plant breeding. CWRs can play an important role in broadening genetic bases and introgression of economical traits into crops, but their direct use by breeders for varietal improvement program is usually not advantageous due to the presence of crossing or chromosome introgression barriers with cultivated species as well as their high frequencies of agronomically undesirable alleles. Linkage drag may subsequently result in unfavourable traits in the subsequent progeny when segments of the genome linked with quantitative trait loci (QTL), or a phenotype, are introgressed from wild germplasm. Here, we first present an overview in regards to the contribution that wild species have made to improve biotic, abiotic stress tolerances and yield-related traits in crop varieties, and secondly summarise the various challenges which are experienced in interspecific hybridization along with their probable solutions. We subsequently suggest techniques for readily harnessing these wild relatives for fast and effective introgression of exotic alleles in pre-breeding research programs.

Comprehensive study on impact assessment of lockdown on overall ambient air quality amid COVID-19 in Delhi and its NCR, India

Indian government announced the complete lockdown from 25 March, 2020 for all outdoor activities across the country due to containment of COVID-19. This study is an attempt to assess the impacts of lockdown on ambient air quality in five cities of Indian National Capital Region including Delhi, Gurugram, Noida, Ghaziabad and Faridabad. In this context, the data of air pollutants (PM₁₀, PM_2.5, NOx, NO, NO₂, SO₂, NH₃, SO₂, CO, and C₆H₆) from 36 locations of the study area were analyzed from 1^st March to 1^st May, 2020. The results showed that PM₁₀ and PM_2.5 level decreased upto 55-65 %. NOx and NO have shown maximum reduction (∼ 50-78 %). Similarly, consistent and significant reduction in other air pollutants such as SO₂ (∼33 %), CO (∼45 %), NH₃ (∼27 %) and C₆H₆ (∼53 %) has been observed. During lockdown Air Quality Index (AQI) shows improvement as its value significantly decreased (∼ 45 %-68 %). An interesting feature observed that during first week of lockdown O₃ decreased but later it increased by ∼19-27%. The study suggests that this pandemic gives lessons for interventions for urban air pollution mitigation in controlling the health impact due to urban air pollution.

The Great Smog Month and Spatial and Monthly Variation in Air Quality in Ambient Air in Delhi, India

BACKGROUND

In recent years, poor urban air quality in Delhi, India has gained significant attention. Episodic events including crop stubble burning and Diwali celebrations are considered major factors in the worsening quality of ambient air.

OBJECTIVE

This study aimed to investigate spatial and monthly variation as well as the role of episodic events in ambient air quality in Delhi, including the 'Great Smog' month of November 2017.

METHODS

Monitoring of air pollutants (particulate matter (PM₁₀, PM_2.5, PM₁) and nitrogen dioxide (NO₂)) was carried out at three distinct locations of Delhi from April 2017-February 2018. The concentration of NO₂ was measured using a modified Jacob and Hochheiser method and PM was measured using a GRIMM aerosol spectrometer. Air quality index was also determined to identify the effects of air pollution on human health.

RESULTS

Overall, the levels of air pollution were found to be approximately 2.1-3.2 times higher along a traffic intersection and about 1.4-2.0 times higher in a commercial area compared with an institutional area. The highest average monthly concentrations of PM₁₀, PM_2.5, PM₁ and NO₂ were 768, 374, 298 and 149 μg/m₃, respectively, during the Great Smog month of November 2017. November and August were recorded as the most polluted and cleanest months, respectively, in the city. Generally, poor to severe categories of the air quality index (AQI) were obtained from October to February. Higher concentrations during November were attributed to stubble burning in the nearby states of Delhi with the additive effect of fireworks during Diwali celebrations.

CONCLUSIONS

Severe ambient air quality as observed in the present study is a serious matter of concern for the health of Delhi's population. To control spikes in poor air quality during episodic events, it is imperative to raise awareness among farmers regarding the severe health hazards of stubble burning.

COMPETING INTERESTS

The authors declare no competing financial interests.

A comprehensive study on spatio-temporal distribution, health risk assessment and ozone formation potential of BTEX emissions in ambient air of Delhi, India

The hazardous air pollutants like benzene, toluene, ethylbenzene and xylene (BTEX) are considered as toxic because of their role in ozone formation and adverse effects on human health. Owing to this, the present study was carried out at six spatially distributed sites in Delhi from November 2017- June 2018. Activated charcoal tubes were used to collect samples of BTEX and were further analyzed using GC-FID. The minimum BTEX concentration was found at institutional site (9.94 μg/m³) and maximum at roadside site (103.12 μg/m³) with the average of 46.66 μg/m³. Also, the levels of BTEX were 1.18-1.74 times higher during rush hours as compared to non-rush hours. The high T/B ratio (2.26-3.41) observed is the indication of the traffic-originated sources of emission. The cancer risks calculated for benzene at probability 0.50 ranged as 1.29E-06 - 1.80E-05, whereas 4.09E-06 - 3.40E-05 at probability 0.95, which were higher than the acceptable value of 1.0E-06. The non-cancer health risks in terms of hazard index were observed less than unity i.e. within acceptable limit. The total ozone formation potential (OFP) was obtained as 207.51 ± 123.40 μg/m³ with maximum potential by toluene. Such high levels of BTEX, cancer risks and OFP obtained in the study especially at roadside and connectivity hub are harmful for people residing near these areas, and also to large commuters, who are exposed to such emissions during travelling.

Impact of biomass fuel exposure from traditional stoves on lung functions in adult women of a rural Indian village

Introduction

Exposure to biomass fuel (BMF) from traditional cookstoves inflicts an enormous burden of morbidities in women across the developing world. This study aims to assess the lung function and its association with the indoor air pollutants generated using BMF.

Materials and Methods

This cross-sectional study including 310 women was conducted in a rural village of India. Households were divided into two groups based on the cooking fuel, the BMF group and the liquefied petroleum gas (LPG) group. Information on respiratory symptoms and socioeconomic status was obtained using a standard questionnaire. Indoor air concentration for PM₁₀and PM_2.5was measured during cooking hours. Pulmonary function tests (PFTs) were conducted for the women inhabitants.

Results

On comparing the two groups, the concentration of PM₁₀(890.26 ± 59.59 vs. 148.66 ± 31.97) μg/m³ and PM_2.5(728.90 ± 50.20 vs. 99.76 ± 41.80) μg/m³ (P < 0.01) were higher in the group using BMF. The respiratory symptoms such as wheezing, dyspnea, chronic cough, and nocturnal cough, were significantly more common in the group using BMF. A significant difference was seen in the lung function indices between the two groups. A significant negative correlation of respiratory indices with duration of exposure and the particulate matter (PM) values suggested a greater decline on lung function among women exposed to increased concentrations of PM. On comparing participants with normal and abnormal PFT, it was seen that the use of BMF (odds ratio [OR] 8.01; 95% confidence interval [CI] 4.80, 13.36, P < 0.001) and the duration of exposure to BMF (OR 1.16; 95% CI 1.13, 1.20., P < 0.001) increased the odds of having an abnormal PFT.

Conclusions

This study shows a high prevalence of respiratory symptoms and an abnormal pulmonary function in women exposed to BMF.

Genetic Diversity Studies Based on Morphological Variability, Pathogenicity and Molecular Phylogeny of the Sclerotinia sclerotiorum Population From Indian Mustard (Brassica juncea)

White mold or stem rot disease are ubiquitously distributed throughout the world and the causal organism of this disease Sclerotinia sclerotiorum (Lib.) de Bary, is known to infect over 400 plant species. Sclerotinia stem rot is one of the most devastating fungal diseases and poses a serious threat to the worldwide cultivation of oilseed Brassica including India. S. sclerotiorum pathogen usually infects the stem but in severe cases leaves and pods also affected at different developmental stages that deteriorate not only the oil quality but also causing the seed and oil yield losses up to 90% depending on the severity of the disease infestation. This study investigated the morphological and molecular characterization of pathogenic S. sclerotiorum (Lib) de Bary geographical isolates from oilseed Brassica including Brassica juncea (Indian mustard). The aim of this study was to compare isolates of S. sclerotiorum originated from different agro-climatic conditions and to analyse similarity or differences between them as well as to examine the virulence of this pathogen specifically in Brassica for the first time. The collection of S. sclerotiorum isolates from symptomatic Brassica plants was done and analyzed for morphological features, and molecular characterization. The virulence evaluation test of 65 isolates on four Brassica cultivars has shown 5 of them were highly virulent, 46 were virulent and 14 were moderately virulent. Phylogenetic analysis encompassing all the morphological features, SSR polymorphism, and ITS sequencing has shown the existence of high genetic diversity among the isolates that categorized all the isolates in three evolutionary lineages in the derived dendrogram. Further, genetic variability analysis based on sequences variation in ITS region of all the isolates has shown the existence of either insertions or deletions of the nucleotides in the ITS region has led to the interspecies variability and observed the variation were in a clade-specific manner. Together this analysis observed the existence of higher heterogeneity and genetic variability in S. sclerotiorum isolates collection and indicates the presence of clonal and sexual progenies of the pathogen in the mustard growing regions of India surveyed in this study. With a higher level of genetic variability and diversity among the S. sclerotiorum population needs robust screening approaches to identify the donor parent and utilize them in resistance breeding program for effectively counter the menace of stem rot disease in Brassica.

Commuter exposure to inhalable, thoracic and alveolic particles in various transportation modes in Delhi

A public health concern is to understand the linkages between specific pollution sources and adverse health impacts. Commuting can be viewed as one of the significant-exposure activity in high-vehicle density areas. This paper investigates the commuter exposure to inhalable, thoracic and alveolic particles in various transportation modes in Delhi, India. Air pollution levels are significantly contributed by automobile exhaust and also in-vehicle exposure can be higher sometime than ambient levels. Motorcycle, auto rickshaw, car and bus were selected to study particles concentration along two routes in Delhi between Kashmere Gate and Dwarka. The bus and auto rickshaw were running on compressed natural gas (CNG) while the car and motorcycle were operated on gasoline fuel. Aerosol spectrometer was employed to measure inhalable, thoracic and alveolic particles during morning and evening rush hours for five weekdays. From the study, we observed that the concentration levels of these particles were greatly influenced by transportation modes. Concentrations of inhalable particles were found higher during morning in auto rickshaw (332.81 ± 90.97 μg/m(3)) while the commuter of bus exhibited higher exposure of thoracic particles (292.23 ± 110.45 μg/m(3)) and car commuters were exposed to maximum concentrations of alveolic particles (222.37 ± 26.56 μg/m(3)). We observed that in evening car commuters experienced maximum concentrations of all sizes of particles among the four commuting modes. Interestingly, motorcycle commuters were exposed to lower levels of inhalable and thoracic particles during morning and evening hours as compared to other modes of transport. The mean values were found greater than the median values for all the modes of transport suggesting that positive skewed distributions are characteristics of naturally occurring phenomenon.

Anti-malarial property of steroidal alkaloid conessine isolated from the bark of Holarrhena antidysenterica

Background

In the face of chronic and emerging resistance of parasites to currently available drugs and constant need for new anti-malarials, natural plant products have been the bastion of anti-malarials for thousands of years. Moreover natural plant products and their derivatives have traditionally been a common source of drugs, and represent more than 30% of the current pharmaceutical market. The present study shows evaluation of anti-malarial effects of compound conessine isolated from plant Holarrhena antidysenterica frequently used against malaria in the Garhwal region of north-west Himalaya.

Methods

In vitro anti-plasmodial activity of compound was assessed using schizont maturation and parasite lactate dehydrogenase (pLDH) assay. Cytotoxic activities of the examined compound were determined on L-6 cells of rat skeletal muscle myoblast. The four-day test for anti-malarial activity against a chloroquine-sensitive Plasmodium berghei NK65 strain in BALB/c mice was used for monitoring in vivo activity of compound. In liver and kidney function test, the activity of alkaline phosphatase (ALP) was examined by p-NPP method, bilirubin by Jendrassik and Grof method. The urea percentage was determined by modified Berthelot method and creatinine by alkaline picrate method in serum of mice using ENZOPAK/CHEMPAK reagent kits.

Results

Compound conessine showed in vitro anti-plasmodial activity with its IC₅₀ value 1.9 μg/ml and 1.3 μg/ml using schizont maturation and pLDH assay respectively. The compound showed cytotoxity IC₅₀= 14 μg/ml against L6 cells of rat skeletal muscle myoblast. The isolated compound from plant H. antidysenterica significantly reduced parasitaemia (at 10 mg/kg exhibited 88.95% parasite inhibition) in P. berghei-infected mice. Due to slightly toxic nature (cytotoxicity = 14), biochemical analysis (liver and kidney function test) of the serum from mice after administration of conessine were also observed.

Conclusion

The present investigation demonstrates that the compound conessine exhibited substantial anti-malarial property. The isolated compound could be chemically modified to obtain a more potent chemical entity with improved characteristics against malaria.

Primary non-Hodgkin lymphoma of liver

Primary non-Hodgkin lymphoma (nhl) of liver is a very rare malignancy. Here, we report the case of a 65-year-old man who presented with constipation and right groin pain of 2 months’ duration. A computed tomography (ct) scan of the abdomen incidentally detected multiple hypodense nodules in both lobes of the liver. Diagnosis of primary nhl of liver was made using ultrasound-guided biopsy. Extensive investigations—which included bone marrow biopsy; fluorescence in situ hybridization; flow cytometry; ct scan of chest, abdomen, and pelvis; and whole-body positron-emission tomography—showed no involvement of bone marrow, lymph nodes, spleen, or any other organ. The patient is currently being treated with a chop-r (cyclophosphamide–doxorubicin–vincristine–prednisolone/rituximab) regimen. The case has many unique features, including normal liver function tests, especially that for lactate dehydrogenase; no type B symptoms; and negative serology for viruses. The case demonstrates that primary hepatic lymphoma should be considered in the differential diagnosis of space-occupying liver lesions in presence of normal levels of alpha-fetoprotein and carcinoembryonic antigen. The literature is extensively reviewed.

Plasmodium falciparum gametocytaemia with chloroquine chemotherapy in persistent malaria in an endemic area of India

BACKGROUND & OBJECTIVE

Gametocyte sex-ratio in Plasmodium falciparum malaria is an important determinant of transmission success and basis of disease epidemiology. Information on ratio of male to female gametocytes after an exposure of antimalarial regimens under field conditions is very limited. In this retrospective study we observed high densities of gametocytes along with high sex-ratio in P. falciparum cases, which may be responsible for persistent malaria transmission in this area.

METHODS

Laksar PHC of Hardwar district, Uttarakhand State, India was selected because it contributed 90 per cent of the total malaria cases. A total of 568 uncomplicated P. falciparum malaria patients were assessed to investigate prevalence of gametocytes while 339 P. falciparum thick smears containing 5620 gametocytes were screened for measuring the gametocyte density for microgametocyte (male) and macrogametocyte (female). Homology of variance ('F' test) was checked on days 7 and 14 including the variables and risk factors namely fever, parasitaemia, gametocyte carriage in sensitive and resistant chloroquine treated P. falciparum cases.

RESULTS

Slide positivity rate (SPR) increased drastically from 0.23 to 11.4 per cent with the predominance in P. falciparum infection after 1998. All 568 cases showed gametocytes in their peripheral blood, of which 109 (19%) were infected with rings and gametocytes and 459 (81%) had gametocytes stages in their peripheral blood while 422 (74.3%) cases were infected with ring stages only. Of the 339 P. falciparum positive blood smears, 5620 gametocytes were screened for their sex-ratio. The mean sex-ratio was 0.31 (3.22 female per male). Prevalence of gametocytaemia was significantly higher (P<0.05) in chloroquine (CQ)- resistant than in CQ-sensitive patients with days 7 and 14 follow up. The homology of variance with risk factors for gametocytes on days 7 and 14 were highly significant (P<0.001) in the study period but during the post-exposure period of days 3 and 5, these were insignificantly correlated.

INTERPRETATION & CONCLUSION

A high density of P. falciparum gametocytes was observed at the time of preparation of blood slide on day 0. Improper chloroquine treatment along with poor patient compliance for radical treatment and the presence of chloroquine resistant P. falciparum malaria may have enhanced the prevalence and density of P. falciparum gametocytes which was instrumental in signaling the persistent malaria in this area.

Isolation and characterization of microsomal omega-6-desaturase gene (fad2-1) from soybean

A genomic DNA sequence (fad2-1) encoding seed specific microsomal 0-6 desaturase was isolated from soybean (Glycine max. L cv. Pusa-9702). A positive genomic clone of 1852 nucleotides containing a single uninterrupted 3' end exonic region with an ORF of 1140 bp encoding a peptide of 379 amino acids, a complete 3' UTR of 206 bp and 86 bp of 5' UTR interrupted by a single intron of 420 bp was obtained on screening the sub-genomic library of soybean. Southern blots revealed at least two copies of the gene per haploid genome. Analysis of the translated product showed the presence of three histidine boxes, with the general sequence HXXXH and five probable transmembrane segments reported to be involved in substrate specificity.

Liquid chromatographic determination of amodiaquine in human plasma

A normal-phase high-performance liquid chromatographic method using dichloromethane- methanol-1M perchloric acid (100:10:0.9, v/v/v) at a flow rate of 1.0 ml min(-1) on a LiChrospher Si column with UV (254 nm) detection has been developed for the determination of amodiaquine and its metabolites desethyl amodiaquine and bisdesethyl amodiaquine in plasma. The limit of quantification was 5 ng ml(-1). Mean within-day and day-to-day coefficients of variation (CV) were 4.10 and 6.27% for amodiaquine, 3.43 and 4.80% for desethyl amodiaquine and 3.53 and 5.23% for bisdesethyl amodiaquine, respectively. Mean extraction recovery of amodiaquine, desethyl amodiaquine and bisdesethyl amodiaquine from plasma were 82.48, 74.50 and 69.65%, respectively. Chloroquine and its metabolite desethyl chloroquine, quinine, sulfadoxine and primaquine do not interfere in the detection of amodiaquine, desethyl amodiaquine and bisdesethyl amodiaquine in plasma.

Multi-drug resistant Plasmodium falciparum malaria in Assam, India: timing of recurrence and anti-malarial drug concentrations in whole blood

The susceptibility of 23 cases of Plasmodium falciparum malaria from the Sonapur primary health center in the Kamrup district of Assam, India to different antimalarials was investigated using the 28-day World Health Organization in vivo test. Whole blood concentrations of chloroquine, sulfadoxine, and quinine were determined at different intervals and at the time of parasites recrudescence after completion of treatment with the respective drugs to confirm the status of drug sensitivity. A case of multi-drug resistant P. falciparum malaria was found where recrudescence occurred, despite standard oral treatment with chloroquine, sulfadoxine/pyrimethamine, and quinine sequentially. Whole blood concentrations of chloroquine, sulfadoxine, and quinine at the time of recrudescence were 0.35 microg/ml (day 7), 18 microg/ml (day 14), and 0.009 microg/ml (day 14), respectively. Therefore, monitoring of drug-resistant P. falciparum malaria and its proper treatment should be intensified to check the spread of multi-drug resistant strains in other parts of the country.

Mediastinal lymph node sampling following positron emission tomography with fluorodeoxyglucose imaging in lung cancer staging

OBJECTIVES

To evaluate the predictive accuracy as well as the rates of false-positive and false-negative results of CT and positron emission tomography (PET)-fluorodeoxyglucose (FDG) imaging in detecting the metastatic intrathoracic lymph nodes in patients with suspected or proven non-small cell lung cancer (NSCLC). Our other objective was to determine the need for routine invasive sampling procedure in confirming PET/CT staging results.

METHODS

The results of CT and PET-FDG scanning in 77 patients with suspected or proven NSCLC were correlated with the histologic findings of hilar/mediastinal lymph node sampling using mediastinoscopy, open biopsy, thoracotomy, or thoracotomy with resection. Patients were then classified into resectable and unresectable groups based initially on PET results and compared to histologic findings.

RESULTS

The sensitivity, specificity, and accuracy of CT and PET for detecting metastatic lymphadenopathy were 68%, 61%, 63%, and 87%, 91%, and 82%, respectively. A change of management with routine sampling following PET was seen in five of six patients (83%) with false-positive findings (13%) but in none of four patients (9%) with false-negative findings.

CONCLUSION

The false-positive findings of PET-FDG imaging affected selection of treatment in 83% of patients. However, false-negative results did not change management in any patient. This could potentially prevent unnecessary invasive thoracotomy, mediastinoscopy, or other sampling procedures in patients with negative PET results.

Clinical Utility of PET-FDG Imaging in Differentiation of Benign from Malignant Adrenal Masses in Lung Cancer

This study was designed to evaluate the sensitivity, specificity, and predictive accuracy of PET-FDG imaging in detecting metastatic disease involvement of adrenal glands in patients with lung cancer. We wanted to compare efficacy of positron emission tomography (PET)-fluorodeoxyglucose (FDG) imaging to computed tomography (CT) scanning in differentiating benign from malignant involvement of adrenal glands in patients with lung cancer. Thirty patients with biopsy-proven lung cancer and abnormal findings on PET and/or CT scanning were studied for presence of adrenal abnormality suggestive of metastatic disease involvement (n = 26) or benign adrenal enlargement (n = 4). The results of PET and CT scanning were compared to histological findings and/or clinical follow-up for at least 1 year for presence or absence of adrenal metastases. PET-FDG imaging correctly detected the presence of metastatic involvement in 17 of 18 patients and excluded metastatic involvement in 11 of 12 patients for sensitivity, specificity, and accuracy of 94.4%, 91.6%, and 93.3%, respectively. CT scanning showed enlarged adrenals without metastases in 8 of 30 patients and normal-sized adrenals in the presence of metastases in 5 of 30 patients. There was a false-positive PET finding in 1 patient and a false-negative PET finding in another patient. PET-FDG imaging is a highly sensitive, specific, and accurate test to differentiate benign from malignant involvement of adrenal glands in patients with lung cancer and often ambiguous findings on CT scanning.

Investigation of malaria prevalence at National Thermal Power Corporation, Shaktinagar, Sonbhadra District (Uttar Pradesh), India

Malaria in industrial complexes is promoted by extensive mosquitogenic potential generated by excavations and importation of parasite through migratory labor. The National Thermal Power Corporation (NTPC), Shaktinagar, Sonbhadra district was surveyed for malariogenic conditions from 1994 to 1996. The major mosquito breeding sites were drains, storm-water drains, lakes, outside tanks, overhead tanks, sluice-valve chambers, ornamental tanks, wells, pit wells and water reservoirs, etc. Anopheles culicifacies was the major vector of malaria in this area. Sibling species identification of An. culicifacies revealed that species C predominated during the transmission season and responsible to transmit malaria. Insecticide susceptibility tests against An. culicifacies sl showed that An.culicifacies population was 100% susceptible to malathion, fenitrothorn and deltamethrin while it was found 44% resistant to DDT. The malaria cases recorded in 1994, 1995 and 1996 were 847, 590 and 409 respectively. In vitro study on P. falciparum cases showed that 41, 70, 50% of the isolates tested were resistant to chloroquine in 1994, 1995 and 1996 respectively while an in vivo follow-up study showed 20-30% P. falciparum cases resistant to chloroquine. An integrated approach involving alternate vector control measures along with judicious use of insecticides has been suggested to bring down malaria in industrial complexes.

Treatment Outcome of Lung Cancer Patients as Optimized by Preoperative Whole-Body Positron Emission Tomography Fluorodeoxyglucose Imaging

Positron emission tomography (PET) fluorodeoxyglucose (FDG) imaging may be more accurate than computed tomography (CT) scanning for staging of lung cancer disease. In the present study, we evaluate whether whole-body PET-FDG imaging can accurately stratify lung cancer patients by stage and thus predict patient outcome. Forty-one consecutive patients underwent whole-body PET and CT scanning for preoperative staging, which was then confirmed by mediastinoscopy, thoracotomy, and/or other tests revealing distant metastases. The effect of PET on patient management was determined. PET was significantly more accurate than CT for staging of lung cancer (97.6% vs. 70.7%). One-year follow-up for survival rate and treatment response was also compared in different patient groups. PET accurately identified patients with resectable disease (Group A). Group B patients, with medically inoperable disease, and Group C patients, with unresectable advanced disease, had 100% and 53% incidence of adverse events (defined as recurrence, evidence of new disease, or death), respectively. Group A patients with resectable disease who underwent surgery showed the best patient outcome, with only 7% incidence of adverse events. In conclusion, whole-body PET can be useful in identifying a group of lung cancer patients with resectable disease most likely to benefit from surgical resection. Further studies are needed to explore whether PET can predict patient outcome of various lung cancer patients receiving different treatment regimens.

Chloroquine and desethylchloroquine concentrations in blood cells and plasma from Indian patients infected with sensitive or resistant Plasmodium falciparum

The sensitivities of 61 Indian cases of Plasmodium falciparum malaria to chloroquine (CQ) were investigated using in-vitro and in-vivo methods. Concentrations of CQ and desethylchloroquine (DCQ) in blood cells and plasma from CQ-sensitive and -resistant cases were determined 2 and 7 days after initiation of treatment, by HPLC. On day 2, the mean CQ concentrations in the samples collected from the sensitive cases were higher than those in the samples from the resistant patients, in plasma (0.47 v. 0.32 microgram/ml; P < 0.02) and particularly in the blood cells (1.51 v. 0.46 micrograms/ml; P < 0.001). By day 7, however, the CQ concentrations in the two groups were similar. Although, on day 2, the mean ratio of the CQ to DCQ concentrations was significantly higher in the blood cells from the sensitive group than in those from the resistant cases (P < 0.01), the CQ/DCQ ratios for the plasma were similar for the two groups. Similarly, the mean ratio between the blood-cell concentration of CQ on day 2 and the concurrent plasma concentration (BPr) was also relatively high in the sensitive group (P < 0.001).

Comparative efficacy of positron emission tomography with fluorodeoxyglucose in evaluation of small (<1 cm), intermediate (1 to 3 cm), and large (>3 cm) lymph node lesions

PURPOSE

Our objective was to determine if positron emission tomography (PET) with fluorodeoxyglucose (FDG; PET-FDG) imaging is equally efficacious in detection of metastases in small and large mediastinal lymph nodes as compared to CT scanning.

MATERIALS AND METHODS

PET-FDG imaging, CT scanning, and histology results of sampled mediastinal lymph nodes were compared in 54 patients of total 118 patients studied. Efficacy of PET and CT was determined and compared in small (< 1 cm), intermediate (1 to 3 cm), and large (> 3 cm) mediastinal lesions.

RESULTS

PET was accurate in 94% of patients in characterizing "N" disease as compared to 61% with CT. Overall, sensitivity, specificity, and accuracy of PET for staging mediastinal lymph nodes (n = 168 in 54 patients) was 96, 93, and 94%, as compared to 68, 65, and 66% with CT. Positive and negative predictive value of PET in detecting mediastinal adenopathy was 86% and 98%, as compared to 47% and 82% with CT, respectively. PET was also highly reliable and accurate for detecting lymph nodes < 1 cm, 1 to 3 cm, and > 3 cm in size with superior efficacy than CT. Sensitivity, specificity, and accuracy of PET for detecting malignancy in lymph node lesions < 1 cm in size was 97, 82, and 95%, respectively.

CONCLUSION

PET-FDG imaging is equally reliable and accurate for detecting disease in small and large lymph node lesions in patients with suspected or proven lung cancer with better efficacy than CT.

FDG-PET in the staging work-up of patients with suspected intracranial metastatic tumors

OBJECTIVE

To evaluate the role of positron emission tomography with 2-[18F] fluoro-2-deoxy-D-glucose (FDG-PET) in 31 patients with evidence of intracranial metastatic disease.

MATERIALS AND METHODS

PET was used to evaluate the intracranial lesions for glucose hypermetabolism to suggest malignancy, mutiplicity of intracranial lesions, and extracranial foci or sources of disease. Patients with proven malignant intracranial lesions subsequently underwent further corroborative radiologic tests and histologic examination to confirm staging and primary location.

RESULTS

PET identified focal hypermetabolic abnormalities in 19 of 22 intracranial metastases, 2 hypometabolic lesions, and 1 renal cell tumor embolism that hemorrhaged (hypometabolic lesion). It also identified 82% of extracranial primary tumor sites, of which 55% were found only on PET and not on conventional diagnostic tests.

CONCLUSION

FDG-PET may prove valuable in the initial work-up of patients with suspected intracranial metastases.

Chloroquine concentration profile in the community of Mewat region, district Gurgaon (Haryana), India

A survey was conducted to find chloroquine concentration profile in the community of Mewat region district Gurgaon (Haryana) of India. 88 P. falciparum and 3 P. vivax cases were detected out of 148 blood slides examined with a SPR of 61.48. Plasma chloroquine and desethylchloroquine concentrations were determined in 55 P. falciparum and 2 P. vivax patients and 29 persons whose blood slides were negative for malaria parasite before giving any treatment. Mean chloroquine concentrations in cases with P. falciparum parasites and without malaria parasites were 0.018 and 0.016 microg ml(-1) respectively. Chloroquine to desethyl chloroquine ratio was between 2 and 3 in both groups. Only 10 malaria parasite negative cases out of 29 had plasma chloroquine concentrations above 0.016 microg ml(-1) required for malaria chemoprophylaxis. Chloroquine was undetectable in plasma samples of 8 out of 55 P. falciparum cases. Chloroquine plasma concentrations in 21 P. falciparum cases were below therapeutically effective concentration of 0.016 microg ml(-1) suggesting improper treatment while in 29 P. falciparum cases, parasitemia recurred despite required chloroquine concentration confirming chloroquine resistant status. Irregular prophylaxis and lack of proper treatment was one of the major causes of malaria outbreak in this area.

Positron emission tomographic imaging with fluorodeoxyglucose isefficacious in evaluating malignant pulmonary disease

OBJECTIVE

Positron emission tomography (PET), when used with the intravenously administered radiopharmaceutical F-18 fluorodeoxyglucose (FDG), has the potential to help in the evaluation of patients with lung cancer because the radiopharmaceutical is concentrated by metabolically active cells. We conducted a retrospective study of PET-FDG in 96 patients evaluated at our institution over the past 2 years for suspected primary pulmonary neoplasms. PET-FDG results were compared with the findings of computed tomographic scans on the same patients. All patients underwent surgical exploration with or without resection of the malignant tumors. Sites of potential malignancy were subjected to biopsy and/or excision, with subsequent pathologic evaluation.

RESULTS

A total of 96 patients with suspected or proven primary pulmonary malignant disease were evaluated. Sixty-six patients had histologically confirmed malignant tumors, and 30 had benign masses histologically. PET-FDG had an accuracy of detecting malignancy in pulmonary lesions of 92% (sensitivity 97%; specificity 89%). A total of 111 surgically sampled sites were from lymph nodes. PET-FDG was accurate in predicting the malignancy of nodes in 91% of instances, whereas computed tomography was correct in 64%. The sensitivity, specificity, and predictive accuracy of PET in detecting metastatic lymphadenopathy in mediastinal lymph nodes were 98%, 94%, and 95%, respectively. PET-FDG also changed the M stage in 8 (12%) patients (6 with and 2 without metastases). The 6 malignant (positive) lesions were correctly identified by PET-FDG, and the 2 without tumor were accurately predicted as benign (negative).

CONCLUSION

These initial results suggest that PET-FDG is highly accurate in identifying and staging lung cancer. PET-FDG also appears to be more accurate in detecting metastatic mediastinal lymphadenopathy than computed tomographic scan.

Comparative efficacy of positron emission tomography with FDG and computed tomographic scanning in preoperative staging of non-small cell lung cancer

OBJECTIVE

To determine the sensitivity, specificity, and accuracy of positron emission tomography with 2-fluorine-18-fluorodeoxyglucose (PET-FDG) in the preoperative staging (N and M staging) of patients with lung cancer. The authors wanted to compare the efficacy of PET scanning with currently used computed tomography (CT) scanning.

MATERIALS AND METHODS

Results of whole-body PET-FDG imaging and CT scans were compared with histologic findings for the presence or absence of lymph node disease or metastatic sites. Sampling of mediastinal lymph nodes was performed using mediastinoscopy or thoracotomy.

RESULTS

PET-FDG imaging was significantly more sensitive, specific, and accurate for detecting N disease than CT. PET changed N staging in 35% and M staging in 11% of patients. CT scans helped in accurate anatomic localization of 6/57 PET lymph node abnormalities.

CONCLUSION

PET-FDG is a reliable method for preoperative staging of patients with lung cancer and would help to optimize management of these patients. Accurate lymph node staging of lung cancer may be ideally performed by simultaneous review of PET and CT scans.

Sulfalene concentrations in plasma and blood cells of Plasmodium falciparum malaria cases after treatment with metakelfin using high-performance liquid chromatography

A reversed-phase high-performance liquid chromatographic method using acetonitrile-methanol-1 M perchloric acid-water (25:9:0.8:95, v/v/v) at a flow-rate of 1.0 ml min(-1) on LiChrospher 100 RP 18 column (250 x 4 mm; 5 microm) with UV (254 nm) detection has been developed for the determination of sulfalene in plasma and blood cells after oral administration of the antimalarial drug metakelfin. Calibration curves were linear in the range 0.5-100 microg ml(-1). The limit of quantification was 50 ng ml(-1). Within-day and day-to-day coefficients of variation averaged 3.84 and 5.31%, respectively. Mean extraction recoveries of sulfalene from plasma and blood cells were 87.21 and 84.65%, respectively. Mean concentrations of sulfalene in plasma of P. falciparum cases on days 2, 7 and 15 were 44.58, 14.90 and 1.70 microg ml(-1), respectively; in blood cells concentrations of sulfalene were 7.77, 3.25 and 0.75 microg ml(-1), respectively, after oral treatment with two tablets (1000 mg) of metakelfin. Significant difference was recorded on day 2 for sulfalene concentration in blood cells of healthy and P. falciparum cases (t=9.49; P<0.001).

In-vivo and in-vitro sensitivity of Plasmodium falciparum to chloroquine in Chennai (Tamil Nadu), India

In-vitro and in-vivo susceptibility of Plasmodium falciparum to chloroquine were conducted at Chennai city, India. Eighteen (60%) out of 30 cases showed resistance in in-vitro study. EC50 of resistant and sensitive cases were 0.40 and 0.24 mumol chloroquine/l blood respectively, while EC90 were 2.64 and 0.84 mumol chloroquine/l blood respectively. In-vivo tests identified 24 cases (40%) as resistant (23 RI and 1 RII) and 36 (60%) as sensitive out of 60 cases. Eight isolates which were found resistant with in-vitro tests showed sensitive behaviour to chloroquine treatment assessed by in-vivo studies.

Assessing coronary artery disease with dipyridamole technetium-99m-tetrofosmin SPECT: a multicenter trial

Exercise 99mTc-tetrofosmin myocardial scintigraphy is as accurate as exercise 201TI imaging. Thus far, no data are available on tetrofosmin imaging during pharmacologic stress. We evaluated the feasibility of using. 99mTc-tetrofosmin myocardial SPECT during vasodilation with dipyridamole for detecting coronary artery disease.

METHODS

Sixty-four patients, enrolled in three centers in the U.S., underwent one-day dipyridamole/rest tetrofosmin SPECT. Coronary angiography, performed in 59 patients within 2 mo of the SPECT study, revealed normal coronary arteries or insignificant coronary stenosis in 11 patients and significant (> or = 50% luminal diameter stenosis) coronary stenoses in 48 patients.

RESULTS

Sensitivity and specificity of tetrofosmin SPECT for detecting coronary artery disease were 85% and 55%, respectively, in the overall population and 81% and 55% in patients without prior coronary artery bypass surgery. The overall sensitivity and specificity of tetrofosmin tomographic imaging for detection of individual coronary stenoses were 53% and 72%, respectively, in the overall population and 54% and 80% in the patients without prior coronary artery bypass surgery.

CONCLUSION

One-day dipyridamole/rest 99mTc-tetrofosmin myocardial perfusion imaging is feasible and has a high sensitivity for detection of coronary artery disease.

Dependency of standardized uptake values of fluorine-18 fluorodeoxyglucose on body size: comparison of body surface area correction and lean body mass correction

In an attempt to minimize dependency of conventional standardized uptake values (SUVs) of F-18-fluorodeoxyglucose (FDG) normalized for the total body weight (TBW) on patient's body weight, the uses of SUV corrected for the lean body mass (LBM) and that corrected for the body surface area (BSA) have been proposed as alternatives. We compared the dependency of SUVLBM and SUVBSA on the overall body size. FDG-PET images were acquired on 44 patients. SUVLBM and SUVBSA for the liver were determined as previously described. Following normalization of the scales of the values obtained from these two approaches, the mean +/- S.D. was 2.86 +/- 0.52 (SUVLBM) and 2.86 +/- 0.50 (SUVBSA). A linear regression analysis was performed for correlating the liver SUVLBM and SUVBSA, with each of TBW, LBM, BSA and height. The dependency of the two values on TBW was similar. SUVLBM showed a moderate dependency on height (r = 0.56, P = 0.00007), LBM (r = 0.55, P = 0.0001) and BSA (r = 0.51, P = 0.0004), whereas SUVBSA showed no dependency on LBM (r = 0.18, P = 0.24) or height (r = 0.20, P = 0.19), and a minimal dependency on BSA (r = 0.38, P = 0.01). In conclusion, SUVBSA appears to be less dependent on overall body size, particularly height and lean body mass, than SUVLBM.

Repellency of Lantana camara (Verbenaceae) flowers against Aedes mosquitoes

The repellent effect of Lantana camara flowers was evaluated against Aedes mosquitoes. Lantana flower extract in coconut oil provided 94.5% protection from Aedes albopictus and Ae. aegypti. The mean protection time was 1.9 h. One application of Lantana flower can provide more than 50% protection up to 4 h against the possible bites of Aedes mosquitoes. No adverse effects of the human volunteers were observed through 3 months after the application.

Probability of malignancy in solitary pulmonary nodules using fluorine-18-FDG and PET

Nearly one-third of solitary pulmonary nodules are radiographically indeterminate for the presence of malignancy.

METHODS

FDG-PET imaging was used to differentiate benign and malignant solitary pulmonary nodules in 61 patients with radiographically indeterminate nodules. After confirmation of the histological diagnosis, the probability for cancer was established for positive and negative PET scans and compared to the risk estimates calculated using other patient variables.

RESULTS

FDG-PET had a sensitivity, specificity and positive predictive value of 93%, 88% and 92%, respectively, for detecting malignancy in indeterminate solitary pulmonary nodules. The probability of malignancy with a positive PET scan is 83%, which increases with the patient's age (90% in >60 yr) and the size of the nodule. A negative PET scan is associated with only a 4.7% risk of malignancy. FDG-PET also accurately characterized hilar/mediastinal lymphadenopathy in 12 patients with associated lymph node lesions.

CONCLUSION

FDG-PET imaging can be a useful noninvasive test to determine the risk estimate or probability of cancer as well as preoperative staging in patients with radiographically indeterminate solitary pulmonary nodules.

PET-FDG imaging and transthoracic needle lung aspiration biopsy in evaluation of pulmonary lesions. A comparative risk-benefit analysis

BACKGROUND AND OBJECTIVE

Positron emission tomography (PET) utilizing 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) has been demonstrated to be highly accurate in differentiating benign from malignant pulmonary nodules. Transthoracic fine-needle aspiration biopsy (TTNA) is generally the initial procedure of choice in the evaluation of peripheral lesions suspected to be malignant. Our objective was to determine whether PET-FDG imaging, a noninvasive test, was equally efficacious as TTNA in the evaluation of lung lesions suspected to be malignant.

PATIENT SELECTION

Thirty-three patients with 35 lung lesions who had undergone both PET-FDG imaging and TTNA were retrospectively selected from an ongoing prospective study of PET-FDG imaging in the evaluation of solitary pulmonary nodules.

MEASUREMENTS

Diagnostic efficacy was determined by calculating sensitivity, specificity, positive and negative predictive value, and overall predictive accuracy for both PET-FDG imaging and TTNA in differentiating benign from malignant lesions. Complication rate also was documented for the two tests.

RESULTS

The PET imaging correctly identified all 26 malignant lesions, including 21 lesions diagnosed by TTNA and 7 of the 9 benign lung lesions. The TTNA was positive for malignancy in 21 lung lesions and missed the diagnosis of malignancy in 5 lesions. Diagnostic sensitivity, specificity, positive and negative predictive value, and overall predictive accuracy was 100, 78, 93, 100, and 94% for PET imaging and 81, 100, 100, 64, and 86 for TTNA, respectively. Pneumothorax was documented in 16 patients (46%), and 9 patients (26%) required a chest tube. There were no complications with PET imaging.

CONCLUSION

We conclude that PET imaging of the lung is as efficacious as TTNA, with less risk, and offers an alternate noninvasive option in the evaluation and management of lung lesions suspected to be malignant.

Positron emission tomography of lung tumors and mediastinal lymph nodes using [18F]fluorodeoxyglucose. The Members of the PET-Lung Tumor Study Group

Positron emission tomography detects increased glucose uptake in malignant tissue using the glucose analogue [2-18F]fluoro-2-deoxy-D-glucose. We reviewed the scans obtained in 62 patients with lung tumors. All had undergone computed tomography and had tissue-based diagnoses: 22 had adenocarcinomas, 12 had squamous cell carcinomas, 13 had other malignancies, 1 had organizing pneumonia, 1 had a hamartoma, and 13 had granulomas. Positron emission tomography with [2-18F]fluoro-2-deoxy-D-glucose identified 44 of 47 malignancies. Two of three false-negative findings were tumors that were 1 cm2 or less and the other was a bronchioloalveolar carcinoma. All three false-positive findings were granulomas. The sensitivity and specificity of the technique were 93.6% and 80%, respectively, and the positive and negative predictive values were 93.6% and 80%, respectively. The differential uptake ratio was determined in all 62 patients. The mean differential uptake ratio (+/- the standard error of the mean) for malignant tumors was 6.4 +/- 0.56 and that for benign tumors was 1.14 +/- 0.26 (p < 0.0001, t test). Twenty-five of the patients had N2 lymph nodes evaluated pathologically. Positron emission tomography with [2-18F]fluoro-2-deoxy-D-glucose identified negative N2 nodes in 19 of 22 patients (86%) with negative nodes and positive N2 nodes in 2 of 3 patients (66%) with positive nodes, including one instance missed by computed tomography.(ABSTRACT TRUNCATED AT 250 WORDS)

Experience with positron emission tomography (PET) scans in patients with ovarian cancer

Our first year of experience in the use of PET scanning in the management of nine patients with ovarian cancer leads us to conclude that this promising new technique may be more sensitive than either serum CA-125 determinations or computed tomography for the detection and demonstration of residual or recurrent abdominal and pelvic tumor. Seven of these patients underwent second-look laparotomy which confirmed our impressions from preoperative PET scans in six patients, and the one other scan showed a focus of metabolic uptake coinciding with residual tumor in our retrospective review. The clinical courses of two other patients who did not undergo laparotomy confirmed the impressions gained from PET scans.

Positron emission tomography for preoperative staging of colorectal carcinoma

PURPOSE

Positron emission tomography (PET) is an imaging technique based on in vivo cellular metabolism. Increased glucose metabolism in neoplastic cells is detected by using fluorine-18 deoxyglucose. In an ongoing pilot study to determine the usefulness of this technique, PET is compared with computerized tomography (CT) for the preoperative staging of colorectal carcinoma.

METHODS

Sixteen patients were evaluated with both PET and CT of the abdomen and pelvis. Results were compared with operative and histopathologic findings. Fifteen malignant lesions were found in 16 patients by histology. PET had a positive predictive value of 93 percent and a negative predictive value of 50 percent. By comparison CT had a positive predictive value of 100 percent and a negative predictive value of 27 percent.

CONCLUSIONS

These preliminary results indicate that PET has increased sensitivity for staging colorectal carcinoma, whereas CT has higher specificity. The predictive value of a positive PET compares favorably with CT. Furthermore, the predictive accuracy for detection of colorectal carcinoma is 83 percent for PET and 56 percent for CT.

Standardized uptake values of FDG: body surface area correction is preferable to body weight correction

Standardized uptake values (SUVs) are widely used to measure 18F-fluorodeoxyglucose (FDG) uptake in various tumors. It has been reported that normalization of FDG uptake for patient body weight (SUVbw) overestimates FDG uptake in heavy patients, as their fraction of body fat (with low FDG uptake) is often increased. The objective of this study was to determine if "normalization of FDG uptake for the body surface area" (SUVbsa) is independent of the patient's body size and is more reliable than SUVbw.

METHODS

FDG-PET images were acquired on 44 patients (body weight range: 45-115 kg) with cancer. SUVbw [(mCi/g of tissue)/(mCi injected/patient body weight in g)] and SUVbsa [(mCi/g of tissue)/(mCi injected/patient BSA in m2)] were determined for the liver. Since most observers are accustomed to using the SUVbw, the two values were compared by setting the mean SUVbsa equal to that of SUVbw.

RESULTS

SUVbw and SUVbsa were 3.42 +/- 0.85 (mean +/- s.d.) and 3.42 +/- 0.60, respectively. The standard deviation of the SUVbsa was smaller than that of SUVbw. More importantly, there was a strong positive correlation between SUVbw and, not only body weight (r = 0.75) but also BSA (r = 0.68), whereas only a weak correlation between SUVbsa and body weight (r = 0.41) or BSA (r = 0.38) was found with a near flat regression line.

CONCLUSION

SUVbw overestimates FDG uptake in large patients. SUVbsa appears preferable to SUVbw, since it is minimally affected by the body size.

Diagnostic efficacy of PET-FDG imaging in solitary pulmonary nodules. Potential role in evaluation and management

BACKGROUND

Positron emission tomography (PET), a new noninvasive imaging modality, utilizing 2-[F-18]-fluoro-2-deoxy-D-glucose (FDG), has demonstrated increased FDG uptake in lung tumors.

OBJECTIVE

To determine the diagnostic efficacy of PET-FDG imaging in differentiating benign from malignant solitary pulmonary nodules.

PATIENT SELECTION

A prospective study of 30 patients who presented with indeterminate solitary pulmonary nodules less than 3 cm in size based on chest radiograph and computed tomographic (CT) scan.

SETTING

Two tertiary care medical centers in Omaha, Neb: Creighton University Medical Center and the Omaha Veterans Administration Medical Center.

MEASUREMENTS

Positron emission tomographic imaging of the lung was performed 1 h after intravenous injection of 10 mCi of F-18-FDG. Qualitative analysis of the images was performed independently by two observers by visual identification of the areas of increased FDG uptake in the lung nodules. Semiquantitative analysis was performed using computation of differential uptake ratio (DUR). Histologic specimens were obtained in 29 patients (thoracotomy 20, transthoracic needle aspiration biopsy 8, bronchoscopy 1).

RESULTS

Positron emission tomographic imaging correctly identified 27 of 30 pulmonary nodules. Diagnostic accuracy was high with sensitivity of 95 percent and specificity of 80 percent. The positive and negative predictive value of PET imaging for solitary pulmonary nodules was 90 percent and 89 percent, respectively. The DUR values were significantly higher for malignant nodules (mean +/- SD, 5.55 +/- 2.79) than benign nodules (mean +/- SD, 0.95 +/- 0.99) (p < 0.001). There was one false-negative result in a patient with a 1-cm nodule identified as a scar adenocarcinoma. There were two false-positive cases and both had caseating granulomas with active inflammation and Histoplasma organisms.

CONCLUSION

PET-FDG imaging of the lung, a new noninvasive diagnostic test, has a high degree of accuracy in differentiating benign from malignant pulmonary nodules. PET-FDG imaging could complement CT scanning in the evaluation and treatment of patients with solitary pulmonary nodules.

Safety of different dosages of intravenous adenosine used in conjunction with diagnostic myocardial imaging techniques

STUDY OBJECTIVE

To determine the safety of three different dosage regimens of intravenous adenosine.

DESIGN

Open-label, observational safety evaluation.

SETTING

University hospital-based department of nuclear medicine.

PATIENTS

Cohort of 854 patients referred for myocardial perfusion imaging to evaluate their coronary artery disease and who were judged unable to perform physical exercise.

INTERVENTIONS

Subjects underwent myocardial perfusion imaging in conjunction with one of three intravenous dosage regimens: 1 = fixed dosage 140 micrograms/kg/minute for 6 minutes; 2 = dosage titration to a maximum of 140 micrograms/kg/minute; and 3 = dosage titration to a maximum of 200 micrograms/kg/minute. In regimens 2 and 3, maximum tolerated dosages were continued for a minimum of 3 minutes prior to radioisotope injection.

MEASUREMENTS AND MAIN RESULTS

Adenosine-induced hemodynamic, electrocardiographic, and biochemical changes were measured. Adverse effects of the different adenosine dosages were compared. Noncardiac side effects such as flushing, dyspnea, neck tightness, and lightheadedness occurred at a significantly higher rate during regimens 2 and 3 than regimen 1. Chest pain and first- and second-degree atrioventricular block were also more frequent during regimens 2 and 3. However, the frequency of other side effects such as complete heart block, hypotension, and ST segment depression did not differ among the regimens. High-dose adenosine was associated with a significant increase in serum uric acid, a significant decrease in blood glucose, and a significant increase in serum triglyceride levels. Mean changes in hemodynamics and electrocardiographic intervals were also not different among the groups except for a greater increase in PR interval in regimens 2 and 3 than regimen 1. Discontinuation of adenosine was infrequent (< 1%) and did not differ among the regimens.

CONCLUSIONS

Adenosine-assisted myocardial perfusion imaging procedures are relatively safe for evaluating coronary artery disease. Despite 82% of patients reporting at least one side effect, only 10 (< 1%) had to discontinue adenosine. No patient suffered any residual sequelae from the adverse effects. The fixed-dose regimen is associated with fewer subjective side effects and is better tolerated than titration regimens. Appropriate safety precautions should nonetheless be taken during adenosine infusions.

PET of infant in persistent vegetative state

This is the first report of cranial positron emission tomography findings of an infant in a persistent vegetative state. Serial positron emission tomography/2-deoxy-2[18F]fluoro-D-glucose studies demonstrated persistent global reduction of cerebral glucose metabolism, results similar to those found in adults in persistent vegetative states. Positron emission tomography may be useful in confirming this clinical diagnosis in infants.

Clinical applications of positron-emission tomography in cancer

Positron-emission tomography is a unique imaging technique that has shown promise for improving staging, treatment planning, and monitoring of cancer. When used in conjunction with a radioactive glucose analog, positron-emission tomography has proven useful for detecting malignant tissue and quantitating changes in tumor glycolysis during and after treatment. This article reviews the principles of positron-emission tomography and its clinical role in cancer treatment.

Pre-operative staging of colorectal carcinoma using positron emission tomography

Positron emission tomography (PET) is a unique technique for imaging functional metabolism of normal and diseased tissue. Accelerated rate of glucose metabolism typical of malignant tumor cells can be detected by using fluorine-18 deoxyglucose. In this pilot study, PET FDG imaging was compared to computerized tomography for the pre-operative staging of colorectal carcinoma. We prospectively evaluated 16 patients by simultaneously performing PET FDG and CT imaging for lesions in the liver, colon and rectum. The results were compared to the operative findings in all patients. Twenty tumor sites (lymph nodes 5, colon and rectum 13, liver 2) were found on histology in 16 patients. On comparison with histology, sensitivity, specificity and predictive accuracy for detection of tumor sites were 90%, 66% and 87% with PET as compared to 60%, 100%, and 65% with CT. These findings represent increased sensitivity and predictive accuracy for staging of colorectal carcinoma with PET FDG imaging as compared to CT scanning.

Thallium-201 myocardial imaging in patients with coronary artery disease: comparison of intravenous adenosine and oral dipyridamole

OBJECTIVE

To compare thallium-201 (201Tl) myocardial perfusion imaging following intravenous adenosine and oral dipyridamole.

DESIGN

Open-label, randomized, comparison.

SETTING

Outpatient, university-affiliated clinic.

PATIENTS

Fifteen patients with angiographically documented coronary artery disease.

INTERVENTIONS

Planar 201Tl myocardial perfusion imaging following both intravenous adenosine 140 micrograms/kg/min for six minutes and oral dipyridamole suspension 300 mg.

MAIN OUTCOME MEASURES

A comparison between adenosine and dipyridamole was made in the following areas: concordance in interpretation of 201Tl scintigrams, cardiac and noncardiac 201Tl uptake and clearance, hemodynamic and electrocardiographic changes, and adverse effects.

RESULTS

The scintigraphic studies showed perfusion defects in 13 patients (87 percent) after dipyridamole and in 15 patients (100 percent) after adenosine. 201Tl uptake and clearance were quantitated in nine myocardial segments and in four extracardiac segments in each patient. 201Tl uptake was not significantly different between adenosine and dipyridamole studies in most cardiac regions. Extracardiac 201Tl uptake was significantly less in the liver and splanchnic regions following adenosine compared with dipyridamole. 201Tl clearance was not significantly different following adenosine and dipyridamole except in the anterolateral region in the anterior view. Hemodynamic changes following administration of intravenous adenosine and oral dipyridamole were not significantly different. Adverse effects were more common with adenosine than with dipyridamole. Adverse effects with adenosine were transient; however, adverse effects with dipyridamole were prolonged and required reversal with aminophylline in 2 patients. No patients required termination of the adenosine infusion or administration of aminophylline.

CONCLUSIONS

These preliminary data suggest that adenosine 201Tl imaging may be a useful alternative to dipyridamole 201Tl imaging. Although adenosine produces more frequent adverse effects, they are generally better tolerated than those associated with dipyridamole.

Solitary pulmonary nodules: detection of malignancy with PET with 2-[F-18]-fluoro-2-deoxy-D-glucose

It is estimated that nearly one-third of solitary pulmonary nodules (SPNs) may represent bronchogenic carcinoma. The noninvasive imaging methods used currently (ie, plain radiography, computed tomography) are not reliable for accurate detection of malignancy in most SPNs. The authors prospectively evaluated use of positron emission tomography (PET) with 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) for identification of malignancy in 20 patients with noncalcific, radiographically indeterminate SPNs. PET-FDG imaging demonstrated focal hypermetabolism in 13 biopsy-proved malignant nodules, whereas no increased FDG uptake was seen in the seven benign SPNs. Semiquantitative analysis with computation of differential uptake ratios also helped clearly differentiate benign nodules (mean +/- standard deviation, 0.56 +/- 0.27) from malignant nodules (mean +/- standard deviation, 5.63 +/- 2.38) (P less than .001). Thus, PET-FDG imaging may be a potentially useful noninvasive technique for accurate differentiation of benign and malignant SPNs that are radiographically indeterminate.

Considerations in setting up a positron emission tomography center

Clinically oriented imaging with position emission tomography (PET) has come of age. Given an adequate referral base and physician interest, a compelling argument can be made at all levels of the review process for setting up a PET program in a clinical setting. PET is expensive. It is obvious that the cost of running a PET service depends heavily on an institution's ability to obtain reasonable financing. Educational institutions have the opportunity to acquire special funding through a variety of sources. On the other hand, money can be expensive for private entrepreneurs. It appears that in the near future PET centers will probably remain at educational institutions or large well-financed community hospitals able to raise money at reasonable rates until reimbursement issues are better resolved. Finally, the future of clinical PET may hinge significantly on the ability of commercial radiopharmaceutical suppliers to provide regional fluorodeoxyglucose distribution. As an institutional program development, PET offers opportunities by providing unique clinical data aiding the referral pattern. PET may serve as a magnet for recruitment in many areas and may promote interdisciplinary cooperation. A clinical PET center serves both as a model for future and more widespread use of PET and as a training ground for medical personnel. Finally, the unique capabilities of PET may facilitate grant opportunities.

Comparison of adenosine and exercise thallium-201 single-photon emission computed tomography (SPECT) myocardial perfusion imaging. The GE SPECT Multicenter Adenosine Study Group

Pharmacologic stress with dipyridamole has provided useful diagnostic, as well as prognostic, information in patients undergoing thallium-201 myocardial perfusion imaging. With its ultrashort half-life and a potent and consistent vasodilator effect, adenosine may be the coronary vasodilator of choice with myocardial perfusion imaging. Fifty-one healthy subjects and 93 patients with suspected coronary artery disease constituted the study group. In this multicenter study the comparative safety and diagnostic efficacy of single-photon emission computed tomography (SPECT) thallium imaging during adenosine-induced coronary hyperemia was compared with exercise treadmill stress. There was a mean increase in heart rate of 37% and a mean decrease in diastolic blood pressure of 5% during the adenosine infusion of 140 micrograms/kg per min for 6 min. Adenosine infusion was well tolerated in 95% of the subjects. Side effects requiring intervention occurred in seven subjects (5%). None of the subjects experienced a life-threatening complication. The sensitivity, specificity and predictive accuracy for detection of coronary artery disease with use of quantitative analysis was 83%, 87% and 84% for adenosine SPECT and 82%, 80% and 81% for exercise SPECT studies, respectively. Most false negative results with adenosine, as well as exercise SPECT studies, occurred in patients with single-vessel disease. The first-order concordance (no defect vs. defect) and second-order concordance (no defect vs. irreversible vs. reversible defect) was 89% and 78% between the two studies, respectively. Thus, the results of adenosine SPECT imaging are highly concordant with exercise SPECT thallium imaging. Adenosine SPECT thallium imaging provides a safe and highly accurate imaging mode for the detection of coronary artery disease.

Adenosine in myocardial perfusion imaging using positron emission tomography

Because of its unique ability to demonstrate the metabolic consequences of myocardial ischemia, positron emission tomography (PET) is extremely valuable in assessing myocardial viability. PET imaging can identify the myocardial segments that are likely to improve after revascularization and may be more sensitive and specific for the detection of coronary artery disease compared with thallium perfusion imaging. Adenosine has several advantages over dipyridamole as a pharmacologic stress agent for use with PET. It produces maximal vasodilation in a significantly greater percentage of patients, is a more potent coronary vasodilator, and its very short half-life may be ideal for use with the very short half-life radioactive tracers used in PET. When combined with metabolic studies, adenosine may be useful for the assessment of patients who received thrombolytic therapy for an acute myocardial infarction.