International Nosocomial Infection Control Consortium report, data summary of 50 countries for 2010-2015: Device-associated module

BACKGROUND

We report the results of International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2010-December 2015 in 703 intensive care units (ICUs) in Latin America, Europe, Eastern Mediterranean, Southeast Asia, and Western Pacific.

METHODS

During the 6-year study period, using Centers for Disease Control and Prevention National Healthcare Safety Network (CDC-NHSN) definitions for device-associated health care-associated infection (DA-HAI), we collected prospective data from 861,284 patients hospitalized in INICC hospital ICUs for an aggregate of 3,506,562 days.

RESULTS

Although device use in INICC ICUs was similar to that reported from CDC-NHSN ICUs, DA-HAI rates were higher in the INICC ICUs: in the INICC medical-surgical ICUs, the pooled rate of central line-associated bloodstream infection, 4.1 per 1,000 central line-days, was nearly 5-fold higher than the 0.8 per 1,000 central line-days reported from comparable US ICUs, the overall rate of ventilator-associated pneumonia was also higher, 13.1 versus 0.9 per 1,000 ventilator-days, as was the rate of catheter-associated urinary tract infection, 5.07 versus 1.7 per 1,000 catheter-days. From blood cultures samples, frequencies of resistance of Pseudomonas isolates to amikacin (29.87% vs 10%) and to imipenem (44.3% vs 26.1%), and of Klebsiella pneumoniae isolates to ceftazidime (73.2% vs 28.8%) and to imipenem (43.27% vs 12.8%) were also higher in the INICC ICUs compared with CDC-NHSN ICUs.

CONCLUSIONS

Although DA-HAIs in INICC ICU patients continue to be higher than the rates reported in CDC-NSHN ICUs representing the developed world, we have observed a significant trend toward the reduction of DA-HAI rates in INICC ICUs as shown in each international report. It is INICC's main goal to continue facilitating education, training, and basic and cost-effective tools and resources, such as standardized forms and an online platform, to tackle this problem effectively and systematically.

Endoscopic ultrasonography, fine-needle aspiration biopsy guided by endoscopic ultrasonography, and computed tomography in the preoperative staging of non-small-cell lung cancer: a comparison study

BACKGROUND

Current methods for detecting mediastinal lymph node involvement with non-small-cell lung cancer can be inaccurate and are often invasive and expensive.

OBJECTIVE

To assess the utility of endoscopic ultrasonography, fine-needle aspiration biopsy guided by endoscopic ultrasonography, and computed tomography for the detection of metastases to the posterior mediastinal lymph nodes in non-small-cell lung cancer.

DESIGN

Prospective preoperative evaluation of the diagnostic operating characteristics of these procedures.

SETTING

Referral-based academic medical center.

PATIENTS

130 consecutive patients with non-small-cell lung cancer who were otherwise good surgical candidates.

INTERVENTIONS

All patients had initial computed tomography of the chest; those with enlarged nodes were referred for endoscopic ultrasonography. Endoscopic ultrasonography-guided fine-needle aspiration biopsy was done on suspicious contralateral posterior mediastinal or subcarinal lymph nodes identified by ultrasonography. At surgery, lymph nodes were dissected and categorized by location and underwent histopathologic evaluation.

RESULTS

52 patients were ultimately enrolled in the study: Thirty-one had thoracotomy with mediastinal dissection, and 21 had tumors considered unresectable on the basis of preoperative evaluation. Ultrasonography without aspiration biopsy had an overall accuracy of 84% for predicting metastasis to lymph nodes; computed tomography had an accuracy of 49% (P < 0.025). Twenty-four patients had ultrasonography-guided aspiration biopsy; 14 of 24 were ineligible for surgery because cytology showed malignancy. Results of surgical pathology correlated with negative aspiration cytology results in 9 of 10 patients, the one node with false-negative results contained a 2-mm focus of cancer. The accuracy of ultrasonography-guided aspiration biopsy in diagnosing metastasis to lymph nodes was 96%; the results of this test prompted a change in management in 95% of the patients who had the procedure.

CONCLUSIONS

Endoscopic ultrasonography alone or with fine-needle aspiration biopsy adds useful diagnostic information in determining metastasis to posterior mediastinal or subcarinal lymph nodes in patients with non-small-cell lung-cancer. These procedures are especially helpful in the preoperative evaluation of patients with suspicious contralateral mediastinal or "bulky" subcarinal nodes.

Reporting guideline for the early-stage clinical evaluation of decision support systems driven by artificial intelligence: DECIDE-AI

A growing number of artificial intelligence (AI)-based clinical decision support systems are showing promising performance in preclinical, in silico evaluation, but few have yet demonstrated real benefit to patient care. Early-stage clinical evaluation is important to assess an AI system's actual clinical performance at small scale, ensure its safety, evaluate the human factors surrounding its use and pave the way to further large-scale trials. However, the reporting of these early studies remains inadequate. The present statement provides a multi-stakeholder, consensus-based reporting guideline for the Developmental and Exploratory Clinical Investigations of DEcision support systems driven by Artificial Intelligence (DECIDE-AI). We conducted a two-round, modified Delphi process to collect and analyze expert opinion on the reporting of early clinical evaluation of AI systems. Experts were recruited from 20 pre-defined stakeholder categories. The final composition and wording of the guideline was determined at a virtual consensus meeting. The checklist and the Explanation & Elaboration (E&E) sections were refined based on feedback from a qualitative evaluation process. In total, 123 experts participated in the first round of Delphi, 138 in the second round, 16 in the consensus meeting and 16 in the qualitative evaluation. The DECIDE-AI reporting guideline comprises 17 AI-specific reporting items (made of 28 subitems) and ten generic reporting items, with an E&E paragraph provided for each. Through consultation and consensus with a range of stakeholders, we developed a guideline comprising key items that should be reported in early-stage clinical studies of AI-based decision support systems in healthcare. By providing an actionable checklist of minimal reporting items, the DECIDE-AI guideline will facilitate the appraisal of these studies and replicability of their findings.

Bias in artificial intelligence algorithms and recommendations for mitigation

The adoption of artificial intelligence (AI) algorithms is rapidly increasing in healthcare. Such algorithms may be shaped by various factors such as social determinants of health that can influence health outcomes. While AI algorithms have been proposed as a tool to expand the reach of quality healthcare to underserved communities and improve health equity, recent literature has raised concerns about the propagation of biases and healthcare disparities through implementation of these algorithms. Thus, it is critical to understand the sources of bias inherent in AI-based algorithms. This review aims to highlight the potential sources of bias within each step of developing AI algorithms in healthcare, starting from framing the problem, data collection, preprocessing, development, and validation, as well as their full implementation. For each of these steps, we also discuss strategies to mitigate the bias and disparities. A checklist was developed with recommendations for reducing bias during the development and implementation stages. It is important for developers and users of AI-based algorithms to keep these important considerations in mind to advance health equity for all populations.

Is obesity becoming a public health problem in India? Examine the shift from under- to overnutrition problems over time

This study aimed to examine the prevalence and trends of overweight, obesity and undernutrition in recent decades in India. Based on a systematic literature search on PubMed and other data sources, most published studies were regional or local surveys in urban areas, while good representative data from the India National Family Health Surveys (NFHS, 1992-1993, 1998-1999 and 2005-2006) allowed for examining the trends at the national level. Overall, the available data showed that in India, prevalence of overweight was low while that of undernutrition remained high. Overweight was more prevalent among female, urban and high-socioeconomic-status (SES) groups. NFHS data showed that the prevalence of overweight in women and pre-school children did not increase much in the last decade: 10.6% and 1.6% in 1998-1999 to 12.6% and 1.5% in 2005-2006 respectively. As for underweight, NFHS 2005-2006 showed high prevalence among ever-married women (about 35%) and pre-school children (about 42%). The prevalence of overweight and obesity had increased slightly over the past decade in India, but in some urban and high-SES groups it reached a relatively high level. Factors associated with undernutrition need closer examination, and prevention of obesity should be targeted at the high-risk groups simultaneously.

Synthesis, crystal structure, spectral studies, and catechol oxidase activity of trigonal bipyramidal Cu(II) complexes derived from a tetradentate diamide bisbenzimidazole ligand

A new benzimidazole-based diamide ligand-N,N'-bis(glycine-2- benzimidazolyl)hexanediamide (GBHA)-has been synthesized and utilized to prepare Cu(II) complexes of general composition [Cu(GBHA)X]X, where X is an exogenous anionic ligand (X = Cl(-), NO(3)(-), SCN(-)). The X-ray structure of one of the complexes, [Cu(GBHA)Cl]Cl.H(2)O.CH(3)OH, has been obtained. The compound crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 26.464(3) A, b = 10.2210(8) A, c = 20.444(2) A, alpha = 90 degrees, beta = 106.554(7) degrees, gamma = 90 degrees, V= 5300.7(9) A(3), and Z = 8. To the best of our knowledge, the [Cu(GBHA)Cl]Cl.H(2)O.CH(3)OH complex is the first structurally characterized mononuclear trigonal bipyramidal copper(II) bisbenzimidazole diamide complex having coordinated amide carbonyl oxygen. The coordination geometry around the Cu(II) ion is distorted trigonal bipyramidal (tau = 0.59). Two carbonyl oxygen atoms and a chlorine atom form the equatorial plane, while the two benzimidazole imine nitrogen atoms occupy the axial positions. The geometry of the Cu(II) center in the solid state is not preserved in DMSO solution, changing to square pyramidal, as suggested by the low-temperature EPR data g( parallel) > g( perpendicular) > 2.0023. All the complexes display a quasi-reversible redox wave due to the Cu(II)/Cu(I) reduction process. E(1/2) values shift anodically from Cl(-) < NO(3)(-) < SCN(-), indicating that the bound Cl(-) ion stabilizes the Cu(II) ion while the N-bonded SCN(-) ion destabilizes the Cu(II) state in the complex. When calculated against NHE, the redox potentials turn out to be quite positive as compared to other copper(II) benzimidazole bound complexes (Nakao, Y.; Onoda, M.; Sakurai, T.; Nakahara, A.; Kinoshita, L.; Ooi, S. Inorg. Chim. Acta 1988, 151, 55. Addison, A. W.; Hendricks, H. M. J.; Reedijk, J.; Thompson, L. K. Inorg. Chem. 1981, 20 (1), 103. Sivagnanam, U.; Palaniandavar, M. J. Chem. Soc., Dalton Trans. 1994, 2277. Palaniandavar, M.; Pandiyan, T.; Laxminarayan, M.; Manohar, H. J. Chem. Soc., Dalton Trans. 1995, 457. Sakurai, T.; Oi, H.; Nakahara, A. Inorg. Chim. Acta 1984, 92, 131). It is therefore concluded that binding of amide carbonyl oxygen destabilizes the Cu(II) state. The complex [Cu(II)(GBHA)(NO(3))](NO(3)) could be successfully reduced by the addition of dihydroxybenzenes to the corresponding [Cu(I)(GBHA)](NO(3)). (1)H NMR of the reduced complex shows slightly broadened and shifted (1)H signals. The reduction of the Cu(II) complex presumably occurs with the corresponding 2e(-) oxidation of the quinol to quinone. Such a conversion is reminiscent of the functioning of a copper-containing catechol oxidase from sweet potatoes and the met form of the enzyme tyrosinase.

International Nosocomial Infection Control Consortium (INICC) report, data summary of 45 countries for 2012-2017: Device-associated module

BACKGROUND

We report the results of International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2012 to December 2017 in 523 intensive care units (ICUs) in 45 countries from Latin America, Europe, Eastern Mediterranean, Southeast Asia, and Western Pacific.

METHODS

During the 6-year study period, prospective data from 532,483 ICU patients hospitalized in 242 hospitals, for an aggregate of 2,197,304 patient days, were collected through the INICC Surveillance Online System (ISOS). The Centers for Disease Control and Prevention-National Healthcare Safety Network (CDC-NHSN) definitions for device-associated health care-associated infection (DA-HAI) were applied.

RESULTS

Although device use in INICC ICUs was similar to that reported from CDC-NHSN ICUs, DA-HAI rates were higher in the INICC ICUs: in the medical-surgical ICUs, the pooled central line-associated bloodstream infection rate was higher (5.05 vs 0.8 per 1,000 central line-days); the ventilator-associated pneumonia rate was also higher (14.1 vs 0.9 per 1,000 ventilator-days,), as well as the rate of catheter-associated urinary tract infection (5.1 vs 1.7 per 1,000 catheter-days). From blood cultures samples, frequencies of resistance, such as of Pseudomonas aeruginosa to piperacillin-tazobactam (33.0% vs 18.3%), were also higher.

CONCLUSIONS

Despite a significant trend toward the reduction in INICC ICUs, DA-HAI rates are still much higher compared with CDC-NHSN's ICUs representing the developed world. It is INICC's main goal to provide basic and cost-effective resources, through the INICC Surveillance Online System to tackle the burden of DA-HAIs effectively.

Correlates of hallucinations in schizophrenia: A cross-cultural evaluation

INTRODUCTION

Demographic, clinical and familial factors may plausibly influence the manifestation of hallucinations. It is unclear if the pattern of the effects is similar in different environmental/cultural settings.

AIMS

To evaluate factors associated with hallucination from a demographic, clinical and familial perspective in two distinct cultural settings.

METHODS

Patients with a clinical diagnosis of schizophrenia (SZ) or schizoaffective disorder (SZA) were diagnosed systematically using DSM IV criteria. Two independent samples were recruited in India and USA using identical inclusion/exclusion criteria and assessment procedures (n=1287 patients total; 807 Indian and 480 US participants). The association of key demographic and clinical factors with hallucinations of different modalities was examined. To evaluate the impact of familial factors, we separately analyzed correlations among affected sibling pairs (ASPs, n=136, Indian; n=77, US).

RESULTS

The prevalence of different modalities of hallucinations differed in the Indian and US samples, though the rank order of frequency was similar. The pattern of associations between selected variables and the risk of hallucinations was different across cultures, except for some correlations with indices of severity. No significant concordance was observed among the ASPs after correcting for multiple comparisons.

CONCLUSIONS

The factors associated with hallucinations vary across environments. Our results are consistent with a multi-factorial etiology of psychopathology, but re-direct attention to endophenotypic features in the causal chain that precede the symptoms themselves.

Bronchoscopy training: current fellows' experiences and some concerns for the future

OBJECTIVES

To determine current pulmonary fellows' perspectives about their bronchoscopy training.

DESIGN

Survey of 59 pulmonary fellows selected by training program directors to represent their institutions.

SETTING

"Hands-on" symposium at the CHEST 1998 annual meeting, Toronto, Canada.

RESULTS

Fellows reported a mean (+/- SD) of 2.4+/- 0.7 years of training, estimated they had performed 77.7+/-34 bronchoscopies per year, and had generally high estimates of their bronchoscopy proficiency and training. Proficiency estimates correlated with number of procedures cited (r = 0.43, p = 0.001) or level of fellowship training (r = 0.40, p = 0.002). Proficiency ratings (r = 0.63, p = 0.0001) and procedure numbers (r = 0.45, p-0. 0004) correlated with program quality ratings. Approaches to bronchoscopy instruction varied, and most often consisted of one-to-one instruction by faculty (92.5%), lecture-based instruction (74.6%), and case discussions (72.9%). Use of bronchoscopy lectures (p = 0.008) or videos (p = 0.057) were associated with higher self-estimates of proficiency, whereas use of lectures (p = 0.002), a bronchoscopy text (p = 0.009), and one-on-one instruction (p = 0.05) were associated with more highly ranked programs. Major components of training varied among programs. Although most fellows had received instruction encompassed in basic bronchoscopy, fewer had experience with bronchoscopic intubation (71.2%), transbronchial needle aspiration (72.9%), quantitative bacterial culture (64.4%), stent placement (27.1%), laser photocoagulation (25.4%), or cryotherapy (6.8%). Components of bronchoscopy experiences correlated with fellows' estimates of bronchoscopy proficiency and program quality.

CONCLUSIONS

Approaches to bronchoscopy instruction and the components of bronchoscopy experiences vary considerably among institutions and are associated with pulmonary fellows' perceptions of bronchoscopy proficiency and training program quality. Definition of an optimum bronchoscopy curriculum remains necessary.

Comparison of CT and MRI in the pre-operative staging of rectal adenocarcinoma and prediction of circumferential resection margin involvement by MRI

OBJECTIVE

It has been suggested that MRI may be used as the sole modality of choice in pre-operative staging in rectal cancers. Knowledge of tumour stage and a threatened Circumferential Resection Margin (CRM) pre-operatively are essential for planning neo-adjuvant therapy and as predictors of local recurrence. At present most units utilize CT scanning to assess these parameters. The aim of our study was two fold: firstly to examine the accuracy of preop CT and MRI staging of rectal cancers compared with final histology and secondly to assess the accuracy of MRI in predicting penetration of the mesorectal envelope (ME).

PATIENTS AND METHODS

All patients with biopsy proven rectal adenocarcinoma underwent thin slice MRI and CT scan pre-operatively. Forty-seven patients have been prospectively entered into the study: 24 male (median age 68 years; range 38-91 years). Eleven patients were unsuitable for surgery leaving 36 patients available for study.

RESULTS

CT correctly staged patients with T1/T2 rectal cancers more often than MRI (77% vs. 43%, P = 0.226). Patients with T1/T2 tumours were overstaged more often by MRI compared with CT (54% vs. 23%, P = 0.226). A greater proportion of patients with T3 tumours were correctly staged by MRI than CT (76% vs. 41%, P = 0.08); and more T3 disease was understaged by CT than MRI (54 vs. 18%, P = 0.032). CT and MRI staged T4 disease equally. In the assessment of mesorectal envelope integrity, MRI had a sensitivity of 80% and a specificity of 84%. The positive predictive value was 44% and the negative predictive value 96%.

CONCLUSIONS

These results suggest significant differences between accurate pre-operative "T" staging by CT and MRI for rectal cancer. MRI has the potential however, to accurately assess mesorectal envelope invasion. Further analysis is required to assess whether MRI can be used as the sole modality in pre-operative staging of rectal cancers.

Impact of vitamin D fortified milk supplementation on vitamin D status of healthy school children aged 10-14 years

Vitamin D deficiency is a major public health problem, needing immediate attention. We studied the effect of vitamin D fortification of milk in school children. Our results show that fortification of milk is safe and effective strategy to deal with widespread vitamin D deficiency.

INTRODUCTION

Vitamin D deficiency among school children and adolescents is a well-documented major public health problem, needing immediate attention. To assess the effect of vitamin D fortified milk on serum 25 hydroxy vitamin D [S.25(OH)D] levels, we carried out a prospective double-blind randomized control trial in apparently healthy school children, aged 10-14 years.

METHODS

Of 776 subjects recruited out of 796 who consented, 713 (boys-300; girls-413) completed the study. Subjects were randomized into three groups. Group A (n = 237) received 200 ml of unfortified milk per day while group B (n = 243) and group C (n = 233) received 200 ml of milk fortified with 600 IU (15 μg) and 1,000 IU (25 μg) of vitamin D per day for 12 weeks. Serum calcium, phosphate, alkaline phosphatase, S.25(OH)D, and urinary calcium/creatinine ratio were estimated at baseline and after supplementation.

RESULTS

Hypovitaminosis D [25(OH)D < 20 ng/ml] was observed in 92.3 % subjects with mean S.25(OH)D level of 11.69 ± 5.36 ng/ml. There was no significant difference in S.25(OH)D levels among the three groups at baseline. The mean percentage change in S.25(OH)D level in groups B (137.97 %) and C (177.29 %.) were significantly greater than group A (-5.25 %). The percentage of subjects having S.25(OH)D levels >20 ng/ml following supplementation were 5.9 % in group A, 69.95 % in group B, and 81.11 % in group C in comparison to 6.32 %, 4.9 % and 12 %, respectively, at baseline.

CONCLUSION

Fortification of milk with vitamin D is an effective and safe strategy in improving S.25(OH)D levels in children aged 10-14 years.

Evaluation framework to guide implementation of AI systems into healthcare settings

Objectives

To date, many artificial intelligence (AI) systems have been developed in healthcare, but adoption has been limited. This may be due to inappropriate or incomplete evaluation and a lack of internationally recognised AI standards on evaluation. To have confidence in the generalisability of AI systems in healthcare and to enable their integration into workflows, there is a need for a practical yet comprehensive instrument to assess the translational aspects of the available AI systems. Currently available evaluation frameworks for AI in healthcare focus on the reporting and regulatory aspects but have little guidance regarding assessment of the translational aspects of the AI systems like the functional, utility and ethical components.

Methods

To address this gap and create a framework that assesses real-world systems, an international team has developed a translationally focused evaluation framework termed ‘Translational Evaluation of Healthcare AI (TEHAI)’. A critical review of literature assessed existing evaluation and reporting frameworks and gaps. Next, using health technology evaluation and translational principles, reporting components were identified for consideration. These were independently reviewed for consensus inclusion in a final framework by an international panel of eight expert.

Results

TEHAI includes three main components: capability, utility and adoption. The emphasis on translational and ethical features of the model development and deployment distinguishes TEHAI from other evaluation instruments. In specific, the evaluation components can be applied at any stage of the development and deployment of the AI system.

Discussion

One major limitation of existing reporting or evaluation frameworks is their narrow focus. TEHAI, because of its strong foundation in translation research models and an emphasis on safety, translational value and generalisability, not only has a theoretical basis but also practical application to assessing real-world systems.

Conclusion

The translational research theoretic approach used to develop TEHAI should see it having application not just for evaluation of clinical AI in research settings, but more broadly to guide evaluation of working clinical systems.

An evaluation of four different phenotypic techniques for detection of metallo-beta-lactamase producing Pseudomonas aeruginosa

PURPOSE

The present study was undertaken to detect metallo-beta-lactamase (MBL) in nosocomial isolates of Pseudomonas aeruginosa by four different phenotypic methods.

METHODS

Ninety-one consecutive P. aeruginosa isolates were subjected to susceptibility testing by disc-diffusion assay and Vitek 2. Imipenem resistance was determined by three different methods (disc-diffusion, Vitek 2 and E test). Screening for MBL production was done by imipenem-EDTA combined disc test, imipenem-EDTA double-disc synergy test, imipenem-EDTA MBL E test and EDTA disc potentiation using four cephalosporins.

RESULTS

Of 63 imipenem resistant isolates, MBL screening could be done in 56 isolates, of which 48 were MBL positive by combined disc test and 36 by the double disc synergy test. For confirmation of MBL production, MBL E test was done in 30 isolates. All the 30 isolates were confirmed to be MBL positive by the MBL E test method. EDTA disc potentiation using four cephalosporins was not very useful for MBL detection.

CONCLUSIONS

Imipenem-EDTA combined disc test and imipenem-EDTA MBL E test are equally effective for MBL detection, but given the cost-constraints, combined disc test can be used as a convenient screening method in the clinical microbiology laboratory.

Nanosilica facilitates silica uptake, growth and stress tolerance in plants

Nanobiotechnology has gained considerable momentum in the field of plant sciences in the last few years. Nanomaterials of various metal oxides has been utilized for enhancing growth, productivity and in crop protection strategies. Among them, nanosilica has emerged as a key player in orchestrating plant growth and conferring tolerance to various abiotic and biotic stresses. Nanosilica has increased absorptivity that accounts for an increased uptake of silica, although the exact mechanism is not fully understood. Nanosilica uptake in the roots and leaves reduces the accumulation of reactive oxygen species (ROS) and membrane lipid peroxidation. It is known to restrict the entry of sodium ions and other heavy metals in plants. Concurrently, nanosilica deposition in the leaf tissue enhances the plant defense against pathogens. The present review attempts to provide a novel insight into its uptake mechanism and nanosilica mediated abiotic and biotic stress tolerance in plants. This review will also shed light on the prospects and challenges related to application of nanosilica based fertilizers.

Insights into the plant responses to drought and decoding the potential of root associated microbiome for inducing drought tolerance

Global increase in water scarcity is a serious problem for sustaining crop productivity. The lack of water causes the degeneration of the photosynthetic apparatus, an imbalance in key metabolic pathways, an increase in free radical generation as well as weakens the root architecture of plants. Drought is one of the major stresses that directly interferes with the osmotic status of plant cells. Abscisic acid (ABA) is known to be a key player in the modulation of drought responses in plants and involvement of both ABA-dependent and ABA-independent pathways have been observed during drought. Concomitantly, other phytohormones such as auxins, ethylene, gibberellins, cytokinins, jasmonic acid also confer drought tolerance and a crosstalk between different phytohormones and transcription factors at the molecular level exists. A number of drought-responsive genes and transcription factors have been utilized for producing transgenic plants for improved drought tolerance. Despite relentless efforts, biotechnological advances have failed to design completely stress tolerant plants until now. The root microbiome is the hidden treasure that possesses immense potential to revolutionize the strategies for inducing drought resistance in plants. Root microbiota consist of plant growth-promoting rhizobacteria, endophytes and mycorrhizas that form a consortium with the roots. Rhizospheric microbes are proliferous producers of phytohormones, mainly auxins, cytokinin, and ethylene as well as enzymes like the 1-aminocyclopropane-1-carboxylate deaminase (ACC deaminase) and metabolites like exopolysaccharides that help to induce systemic tolerance against drought. This review, therefore focuses on the major mechanisms of plant-microbe interactions under drought-stressed conditions and emphasizes the importance of drought-tolerant microbes for sustaining and improving the productivity of crop plants under stress.

Portal hypertension in north Indian children

Etiological factors associated with portal hypertension in children influence the decision about therapy and the prognosis. This cross-sectional observational study was performed at a tertiary care centre in northern India from January, 1990 to December, 1994. Children below the age of 14 years with suspected portal hypertension were prospectively assembled into a cohort to determine the etiology and clinical profile of portal hypertension. Of the 115 patients with portal hypertension, 76.5% had extrahepatic portal hypertension (EHPH). Remaining 23.5% of the cases had intrahepatic and post-hepatic causes of portal hypertension. Children with EHPH had a significantly earlier onset of symptoms as compared to those with intrahepatic portal hypertension (p = 0.002) and bled significantly more frequently (p = 0.00). Forty per cent of patients with chronic liver disease (CLD) never had jaundice. History suggestive of potential etiological factors could be elicited in only 7% of EHPH patients. The commonest site of block in splenoportal axis was at the formation of the portal vein. An inverse relation of bleeding rates with duration of illness was seen in EHPH. Of the 10 CLD patients in whom liver biopsy could be done, cirrhosis was present in 6 patients. Understanding the natural history of EHPH and portal hypertension due to other etiologies may have significant implications in choosing the appropriate intervention and predicting the outcome.

Phase I study of percutaneous cryotherapy for colorectal liver metastasis

BACKGROUND

The aim was to determine the safety and feasibility of percutaneous cryotherapy for treating irresectable colorectal liver metastases.

METHODS

Liquid nitrogen cryoprobes were inserted percutaneously into metastases using the Seldinger technique under computed tomographic guidance. Single-probe treatments were performed with either 3.6- or 6.3-mm cryoprobes (ice-ball volumes 18 and 59 cm3 respectively), or dual-probe treatments with two adjacent 6.3-mm probes (ice-ball volume 205 cm3). Treatment involved a single freeze--thaw cycle.

RESULTS

Fifteen patients received 25 single-probe treatments and seven patients received 14 dual-probe treatments. The treatment-related mortality rate was zero and complications occurred after six of 39 treatments. Liver metastasis growth was significantly delayed for 2 months after dual-probe but not single-probe treatment. Metastasis cryotherapy stimulated an immediate rise, followed by a fall, in serum carcinoembryonic antigen (CEA) level, associated with immune upregulation that was significantly greater after dual-probe treatments.

CONCLUSION

Ablation zones that were approximately four times larger than those produced by previously described percutaneous techniques delayed the growth of metastases, reduced serum CEA concentration, and induced detectable inflammatory and T-lymphocyte responses. Percutaneous cryotherapy for treatment of colorectal liver metastases is feasible and may have a place in conjunction with chemotherapy.

Induction of oxidative stress in rat epididymal sperm after exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin

The ability of 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD) to induce oxidative stress in various tissues of animals has been reported. The nature and mechanism of action of TCDD on the antioxidant system of sperm has not been studied. In the present study we have sought to investigate whether TCDD induces oxidative stress in the epididymal sperm of rats. Subchronic doses of TCDD (1, 10, and 100 ng/kg body weight per day) were administered orally to male Wistar strain rats for 45 days. After 24 h of the last treatment the rats were killed using diethyl ether. The epididymides were removed and cleared from the adhering tissues. Epididymal sperm were collected by cutting the epididymides into small pieces in Ham's F12 medium, and counted using a hemocytometer. The epididymal sperm counts in the TCDD-treated groups decreased in a dose-dependent manner from the control value of 8.2+/-0.14 x 10(8) to 5.31+/-0.15 x 10(8). Since a positive correlation (r=0.95; n=24) was observed between sperm count and DNA content of the epididymal sperm, DNA content was routinely used as an indicator of sperm count, and the results were expressed in terms of both protein and DNA. There was a significant decline in the activities of superoxide dismutase (40+/-2.17 to 27.1+/-0.76/mg protein and 32.41 to 18.07+/-0.76/mg DNA), catalase (2.49+/-0.13 to 2.03+/-0.05/mg protein and 2.01+/-0.05 to 1.35+/-0.05/mg DNA), glutathione reductase (71.2+/-3.87 to 48+/-1.79/mg protein and 57.58+/-1.52 to 31.94/mg DNA) and glutathione peroxidase (22.4+/-1.43 to 16.9+/-1.57/mg protein and 18.08+/-0.61 to 11.38+/-1.22/mg DNA) while there were increases in the levels of hydrogen peroxide (20.8+/-1.96 to 55.3+/-0.88/ mg protein and 16.18+/-1.88 to 36.87+/-0.88/ mg DNA) and lipid peroxidation (2.17+/-0.2 to 6.08/mg protein and 1.75+/-0.12 to 4.05+/-0.12/mg DNA) in the epididymal sperm. The results suggest that graded doses of TCDD elicit depletion of antioxidant defense system in sperm, indicating TCDD-induced oxidative stress in the epididymal sperm. In conclusion, the adverse effect on male reproduction in TCDD-treated rats may be due to the induction of oxidative stress in sperm.

Randomized trial of regional plus systemic fluorinated pyrimidine compared with systemic fluorinated pyrimidine in treatment of colorectal liver metastases

AIM

We report a prospective randomized study comparing survival, response and toxicity in colorectal liver metastasis (CLM) patients treated by either hepatic arterial floxuridine (HAI) plus continuous systemic fluorouracil/folinic acid or systemic fluorouracil/folinic acid.

METHODS

Eighty-four CLM patients received either HAI plus systemic fluorouracil/folinic acid or systemic fluorouracil/ folinic acid.

RESULTS

Significantly more HAI plus systemic, compared with systemic only, patients developed WHO grade 3 or 4 diarrhoea (P=0.004), but significant quality of life differences were not detected. Liver metastasis partial response at 4 months after randomization was significantly greater (P=0.003) in HAI plus systemic (13/29, 45%) compared with systemic only (7/30, 23%) patients. There was no significant difference between groups in the proportion of patients who died from extrahepatic disease progression, or in survival.

CONCLUSION

Combining regional with systemic fluorinated pyrimidines did not improve survival compared with systemic fluorinated pyrimidine.