Reliability of resting metabolic rate between and within day measurements using the Vyntus CPX system and comparison against predictive formulas

Background: To detect longitudinal changes of resting metabolic rate (RMR) resulting from the effects of energetic stress, reliable RMR measurements are crucial. The Vyntus CPX is a new automated indirect calorimetry system for which RMR reliability has not been determined. Additionally, its agreement with common predictive RMR formulas is unknown. Aim: To determine the within and between-day reliability of RMR measurements using the Vyntus CPX system and its agreement with predictive RMR formulas. Methods: Young (31  ±  7 years) healthy participants (n = 26, 12 females, 14 males) completed three measurements of RMR, two consecutive measures on the same day, one the day before/after, all under standardised conditions. Reliability was assessed with pairwise comparisons of between-day at the same time (BDST), within day consecutive measurements (WDCM) and between-day different time (BDDT), for parameters of reliability (mean change (MC), intraclass correlation (ICC) and typical error of measurement (TEM)). Measured RMR values (kcal/day) were compared against predictive values of 4 common formulas. Results: Parameters of reliability (mean, (95% confidence interval)) were: -BDST: MC, 0.2(-2.3-2.7)% (p = 0.67); ICC, 0.92(0.84-0.97); TEM, 4.5(3.5-6.2)%. -WDCM: MC, -2.5(-6.2-1.3)% (p = 0.21); ICC, 0.88(0.74-0.88); TEM, 7.0(5.4-9.8)%. -BDDT: MC, -1.5(-4.8-1.9)% (p = 0.57); ICC, 0.90(0.76-0.95); TEM, 6.1(4.8-8.5)%. RMR_ratios (measured/predicted) were: 1.04  ±  0.14 (Nelson, p = 0.13), 1.03  ±  0.10 (Mifflin, p = 0.21), 0.98  ±  0.09 (Harris-benedict, p = 0.30), 0.95  ±  0.11 (Cunningham₁₉₈₀, p = 0.01), 1.00  ±  0.12 (Cunningham₁₉₉₁, p = 0.90) and 0.96  ±  0.13 (DXA, p = 0.03). Conclusions: The Vyntus CPX is reliable and measured RMR values agreed with four predictive formulas but are lower than Cunningham₁₉₈₀ and DXA RMR estimates for this population.

Precision of the GE Lunar Total Body-Less Head Scan for the Measurement of Three-Compartment Body Composition in Athletes

INTRODUCTION

Dual energy X-ray absorptiometry (DXA) is widely used for the assessment of lean mass (LM), fat mass (FM) and bone mineral content (BMC). When observing standardised protocols, DXA has a high level of precision for the assessment of total body composition, including the head region. However, including the head region may have limited relevance in athletes and can be problematic when positioning taller athletes who exceed scan boundaries. This study investigated the precision of a new total-body-less-head (TBLH) DXA scan for three-compartment body composition measurement in athletes, with outcomes compared to the standard total-body DXA scan.

METHODS

Precision errors were calculated from two consecutive scans with re-positioning (Lunar iDXA, GE Healthcare, Madison, WI), in male and female athletes from a range of sports. TBLH precision was determined from repeat scans in 95 athletes (male n = 55; female n = 40; age: 26.0 ± 8.5 y; body mass: 81.2 ± 20.5 kg; stature: 1.77 ± 0.11 m), and standard total-body scan precision was derived from a sub-sample of 58 athletes (male n = 19; female n = 39; age: 27.6 ± 9.9 y; body mass: 69.6 ± 14.8 kg; stature: 1.72 ± 0.94 m). Data from the sub-sample were also used to compare precision error and 3-compartment body composition outcomes between the standard total-body scan and the TBLH scan.

RESULTS

TBLH precision errors [root mean squared-standard deviation, RMS-SD (coefficient of variation, %CV)] were bone mineral content (BMC): 15.6 g (0.5%), lean mass (LM): 254.3 g (0.4%) and fat mass (FM): 199.4 g (1.3%). These outcomes compared favourably to the precision errors derived from the standard total-body scan [BMC: 12.4 g (0.4%), LM: 202.2 g (0.4%), and FM: 160.8 g (1.1%)]. The TBLH scan resulted in lower BMC (-19.5%), LM (-6.6%), and FM (-4.5%) compared to the total-body scan (BMC: 2,308 vs. 2,865 g; LM: 46,954 vs. 50,276 g; FM: 15,183 vs. 15,888 g, all p<0.005). ConclusionThe TBLH scan demonstrates high in-vivo precision comparable to that of the standard total-body scan in a heterogeneous cohort of athletes. Given the impact of head exclusion on total body composition outcomes, TBLH scans should not be used interchangeably with the standard total-body scan.

Origin of Groundwater Arsenic in a Rural Pleistocene Aquifer in Bangladesh Depressurized by Distal Municipal Pumping

Across South Asia, millions of villagers have reduced their exposure to high-arsenic (As) groundwater by switching to low-As wells. Isotopic tracers and flow modeling are used in this study to understand the groundwater flow system of a semi-confined aquifer of Pleistocene (>10 kyr) age in Bangladesh that is generally low in As but has been perturbed by massive pumping at a distance of about 25 km for the municipal water supply of Dhaka. A 10- to 15-m-thick clay aquitard caps much of the intermediate aquifer (>40- to 90-m depth) in the 3-km² study area, with some interruptions by younger channel sand deposits indicative of river scouring. Hydraulic heads in the intermediate aquifer below the clay-capped areas are 1-2 m lower than in the high-As shallow aquifer above the clay layer. In contrast, similar heads in the shallow and intermediate aquifer are observed where the clay layer is missing. The head distribution suggests a pattern of downward flow through interruptions in the aquitard and lateral advection from the sandy areas to the confined portion of the aquifer. The interpreted flow system is consistent with ³H-³He ages, stable isotope data, and groundwater flow modeling. Lateral flow could explain an association of elevated As with high methane concentrations within layers of gray sand below certain clay-capped portions of the Pleistocene aquifer. An influx of dissolved organic carbon from the clay layer itself leading to a reduction of initially orange sands has also likely contributed to the rise of As.

Reconstruction of limnology and microbialite formation conditions from carbonate clumped isotope thermometry

Quantitative tools for deciphering the environment of microbialite formation are relatively limited. For example, the oxygen isotope carbonate-water geothermometer requires assumptions about the isotopic composition of the water of formation. We explored the utility of using 'clumped' isotope thermometry as a tool to study the temperatures of microbialite formation. We studied microbialites recovered from water depths of 10-55 m in Pavilion Lake, and 10-25 m in Kelly Lake, spanning the thermocline in both lakes. We determined the temperature of carbonate growth and the (18)O/(16)O ratio of the waters that microbialites grew in. Results were then compared to current limnological data from the lakes to reconstruct the history of microbialite formation. Modern microbialites collected at shallow depths (11.7 m) in both lakes yield clumped isotope-based temperatures of formation that are within error of summer water temperatures, suggesting that clumped isotope analyses may be used to reconstruct past climates and to probe the environments in which microbialites formed. The deepest microbialites (21.7-55 m) were recovered from below the present-day thermoclines in both lakes and yield radioisotope ages indicating they primarily formed earlier in the Holocene. During this time, pollen data and our reconstructed water (18)O/(16)O ratios indicate a period of aridity, with lower lake levels. At present, there is a close association between both photosynthetic and heterotrophic communities, and carbonate precipitation/microbialite formation, with biosignatures of photosynthetic influences on carbonate detected in microbialites from the photic zone and above the thermocline (i.e., depths of generally <20 m). Given the deeper microbialites are receiving <1% of photosynthetically active radiation (PAR), it is likely these microbialites primarily formed when lower lake levels resulted in microbialites being located higher in the photic zone, in warm surface waters.

Getting a grip on the evolution of grasping in musteloid carnivorans: a three-dimensional analysis of forelimb shape

The ability to grasp and manipulate is often considered a hallmark of hominins and associated with the evolution of their bipedal locomotion and tool use. Yet, many other mammals use their forelimbs to grasp and manipulate objects. Previous investigations have suggested that grasping may be derived from digging behaviour, arboreal locomotion or hunting behaviour. Here, we test the arboreal origin of grasping and investigate whether an arboreal lifestyle could confer a greater grasping ability in musteloid carnivorans. Moreover, we investigate the morphological adaptations related to grasping and the differences between arboreal species with different grasping abilities. We predict that if grasping is derived from an arboreal lifestyle, then the anatomical specializations of the forelimb for arboreality must be similar to those involved in grasping. We further predict that arboreal species with a well-developed manipulation ability will have articulations that facilitate radio-ulnar rotation. We use ancestral character state reconstructions of lifestyle and grasping ability to understand the evolution of both traits. Finally, we use a surface sliding semi-landmark approach capable of quantifying the articulations in their full complexity. Our results largely confirm our predictions, demonstrating that musteloids with greater grasping skills differ markedly from others in the shape of their forelimb bones. These analyses further suggest that the evolution of an arboreal lifestyle likely preceded the development of enhanced grasping ability.

Constraining carbon sources and growth rates of freshwater microbialites in Pavilion Lake using (14)C analysis

This study determined the natural abundance isotopic compositions ((13)C, (14)C) of the primary carbon pools and microbial communities associated with modern freshwater microbialites located in Pavilion Lake, British Columbia, Canada. The Delta(14)C of dissolved inorganic carbon (DIC) was constant throughout the water column and consistent with a primarily atmospheric source. Observed depletions in DIC (14)C values compared with atmospheric CO(2) indicated effects due either to DIC residence time and/or inputs of (14)C-depleted groundwater. Mass balance comparisons of local and regional groundwater indicate that groundwater DIC could contribute a maximum of 9-13% of the DIC. (14)C analysis of microbial phospholipid fatty acids from microbialite communities had Delta(14)C values comparable with lake water DIC, demonstrating that lake water DIC was their primary carbon source. Microbialite carbonate was also primarily derived from DIC. However, some depletion in microbialite carbonate (14)C relative to lake water DIC occurred, due either to residence time or mixing with a (14)C-depleted carbon source. A detrital branch covered with microbialite growth was used to estimate a microbialite growth rate of 0.05 mm year(-1) for the past 1000 years, faster than previous estimates for this system. These results demonstrate that the microbialites are actively growing and that the primary carbon source for both microbial communities and recent carbonate is DIC originating from the atmosphere. While these data cannot conclusively differentiate between abiotic and biotic formation mechanisms, the evidence for minor inputs of groundwater-derived DIC is consistent with the previously hypothesized biological origin of the Pavilion Lake microbialites.

Ensembl 2009

The Ensembl project (http://www.ensembl.org) is a comprehensive genome information system featuring an integrated set of genome annotation, databases, and other information for chordate, selected model organism and disease vector genomes. As of release 51 (November 2008), Ensembl fully supports 45 species, and three additional species have preliminary support. New species in the past year include orangutan and six additional low coverage mammalian genomes. Major additions and improvements to Ensembl since our previous report include a major redesign of our website; generation of multiple genome alignments and ancestral sequences using the new Enredo-Pecan-Ortheus pipeline and development of our software infrastructure, particularly to support the Ensembl Genomes project (http://www.ensemblgenomes.org/).

Ensembl 2008

The Ensembl project (http://www.ensembl.org) is a comprehensive genome information system featuring an integrated set of genome annotation, databases and other information for chordate and selected model organism and disease vector genomes. As of release 47 (October 2007), Ensembl fully supports 35 species, with preliminary support for six additional species. New species in the past year include platypus and horse. Major additions and improvements to Ensembl since our previous report include extensive support for functional genomics data in the form of a specialized functional genomics database, genome-wide maps of protein–DNA interactions and the Ensembl regulatory build; support for customization of the Ensembl web interface through the addition of user accounts and user groups; and increased support for genome resequencing. We have also introduced new comparative genomics-based data mining options and report on the continued development of our software infrastructure.

Ensembl 2007

The Ensembl (http://www.ensembl.org/) project provides a comprehensive and integrated source of annotation of chordate genome sequences. Over the past year the number of genomes available from Ensembl has increased from 15 to 33, with the addition of sites for the mammalian genomes of elephant, rabbit, armadillo, tenrec, platypus, pig, cat, bush baby, common shrew, microbat and european hedgehog; the fish genomes of stickleback and medaka and the second example of the genomes of the sea squirt (Ciona savignyi) and the mosquito (Aedes aegypti). Some of the major features added during the year include the first complete gene sets for genomes with low-sequence coverage, the introduction of new strain variation data and the introduction of new orthology/paralog annotations based on gene trees.

Ensembl 2006

The Ensembl () project provides a comprehensive and integrated source of annotation of large genome sequences. Over the last year the number of genomes available from the Ensembl site has increased from 4 to 19, with the addition of the mammalian genomes of Rhesus macaque and Opossum, the chordate genome of Ciona intestinalis and the import and integration of the yeast genome. The year has also seen extensive improvements to both data analysis and presentation, with the introduction of a redesigned website, the addition of RNA gene and regulatory annotation and substantial improvements to the integration of human genome variation data.

Acute weight loss followed by an aggressive nutritional recovery strategy has little impact on on-water rowing performance

OBJECTIVES

To assess the influence of moderate, acute weight loss on on-water rowing performance when aggressive nutritional recovery strategies were used in the two hours between weigh in and racing.

METHODS

Competitive rowers (n = 17) undertook three on-water 1800 m time trials under cool conditions (mean (SD) temperature 8.4 (2.0) degrees C), each separated by 48 hours. No weight limit was imposed for the first time trial--that is, unrestricted body mass (UNR1). However, one of the remaining two trials followed a 4% loss in body mass in the previous 24 hours (WT(-4%)). No weight limit was imposed for the other trial (UNR2). Aggressive nutritional recovery strategies (WT(-4%), 2.3 g/kg carbohydrate, 34 mg/kg Na+, and 28.4 ml/kg fluid; UNR, ad libitum) were used in the first 90 minutes of the two hours between weigh in and performance trials.

RESULTS

WT(-4%) had only a small and statistically non-significant effect on the on-water time trial performance (mean 1.0 second, 95% confidence interval (CI) -0.9 to 2.8; p = 0.29) compared with UNR. This was despite a significant decrease in plasma volume at the time of weigh in for WT(-4%) compared with UNR (-9.2%, 95% CI -12.8% to -5.6%; p<0.001).

CONCLUSIONS

Acute weight loss of up to 4% over 24 hours, when combined with aggressive nutritional recovery strategies, can be undertaken with minimal impact on on-water rowing performance, at least in cool conditions.

Ensembl 2005

The Ensembl (http://www.ensembl.org/) project provides a comprehensive and integrated source of annotation of large genome sequences. Over the last year the number of genomes available from the Ensembl site has increased by 7 to 16, with the addition of the six vertebrate genomes of chimpanzee, dog, cow, chicken, tetraodon and frog and the insect genome of honeybee. The majority have been annotated automatically using the Ensembl gene build system, showing its flexibility to reliably annotate a wide variety of genomes. With the increased number of vertebrate genomes, the comparative analysis provided to users has been greatly improved, with new website interfaces allowing annotation of different genomes to be directly compared. The Ensembl software system is being increasingly widely reused in different projects showing the benefits of a completely open approach to software development and distribution.

Ensembl 2004

The Ensembl (http://www.ensembl.org/) database project provides a bioinformatics framework to organize biology around the sequences of large genomes. It is a comprehensive and integrated source of annotation of large genome sequences, available via interactive website, web services or flat files. As well as being one of the leading sources of genome annotation, Ensembl is an open source software engineering project to develop a portable system able to handle very large genomes and associated requirements. The facilities of the system range from sequence analysis to data storage and visualization and installations exist around the world both in companies and at academic sites. With a total of nine genome sequences available from Ensembl and more genomes to follow, recent developments have focused mainly on closer integration between genomes and external data.

Ensembl 2002: accommodating comparative genomics

The Ensembl (http://www.ensembl.org/) database project provides a bioinformatics framework to organise biology around the sequences of large genomes. It is a comprehensive source of stable automatic annotation of human, mouse and other genome sequences, available as either an interactive web site or as flat files. Ensembl also integrates manually annotated gene structures from external sources where available. As well as being one of the leading sources of genome annotation, Ensembl is an open source software engineering project to develop a portable system able to handle very large genomes and associated requirements. These range from sequence analysis to data storage and visualisation and installations exist around the world in both companies and at academic sites. With both human and mouse genome sequences available and more vertebrate sequences to follow, many of the recent developments in Ensembl have focusing on developing automatic comparative genome analysis and visualisation.

The Ensembl genome database project

The Ensembl (http://www.ensembl.org/) database project provides a bioinformatics framework to organise biology around the sequences of large genomes. It is a comprehensive source of stable automatic annotation of the human genome sequence, with confirmed gene predictions that have been integrated with external data sources, and is available as either an interactive web site or as flat files. It is also an open source software engineering project to develop a portable system able to handle very large genomes and associated requirements from sequence analysis to data storage and visualisation. The Ensembl site is one of the leading sources of human genome sequence annotation and provided much of the analysis for publication by the international human genome project of the draft genome. The Ensembl system is being installed around the world in both companies and academic sites on machines ranging from supercomputers to laptops.

Beta-hydroxy-beta-methylbutyrate (HMB) supplementation does not affect changes in strength or body composition during resistance training in trained men

This investigation evaluated the effects of oral beta-hydroxy-beta-methylbutyrate (HMB) supplementation on training responses in resistance-trained male athletes who were randomly administered HMB in standard encapsulation (SH), HMB in time release capsule (TRH), or placebo (P) in a double-blind fashion. Subjects ingested 3 g x day(-1) of HMB or placebo for 6 weeks. Tests were conducted pre-supplementation and following 3 and 6 weeks of supplementation. The testing battery assessed body mass, body composition (using dual energy x-ray absorptiometry), and 3-repetition maximum isoinertial strength, plus biochemical parameters, including markers of muscle damage and muscle protein turnover. While the training and dietary intervention of the investigation resulted in significant strength gains (p < .001) and an increase in total lean mass (p = .01), HMB administration had no influence on these variables. Likewise, biochemical markers of muscle protein turnover and muscle damage were also unaffected by HMB supplementation. The data indicate that 6 weeks of HMB supplementation in either SH or TRH form does not influence changes in strength and body composition in response to resistance training in strength-trained athletes.

Initial sequencing and analysis of the human genome

The human genome holds an extraordinary trove of information about human development, physiology, medicine and evolution. Here we report the results of an international collaboration to produce and make freely available a draft sequence of the human genome. We also present an initial analysis of the data, describing some of the insights that can be gleaned from the sequence.

Prevalence and significance of gallbladder abnormalities seen on sonography in intensive care unit patients

OBJECTIVE

We evaluated sonographic abnormalities of the gallbladder other than acalculous cholecystitis across a broad range of intensive care unit (ICU) patients.

SUBJECTS AND METHODS

Fifty-five consecutive patients (age range, 18-94 years old; mean age, 56 years; 33 men, 22 women), who were admitted to the ICU with a variety of diagnoses, underwent sonography of the gallbladder twice a week. Patients with gallbladder calculi were excluded from the study. The gallbladder was examined for the recognized sonographic features of acalculous cholecystitis: gallbladder wall thickening, gallbladder distention, intramural gallbladder lucencies (striated gallbladder wall), pericholecystic fluid, gallbladder sludge, and Murphy's sign. These findings were correlated with clinical and laboratory parameters that are associated with acalculous cholecystitis: fever, WBC, liver function tests, levels of serum bilirubin, mechanical ventilation status, and administration of parenteral nutrition, narcotic analgesics, antibiotics, and pressor agents.

RESULTS

Eleven of the 55 patients were found to have gallbladder calculi and were excluded from the study. Thirty-seven (84%) of the remaining 44 patients had at least one sonographic abnormality while in the ICU. Twenty-five (57%) of the 44 patients had as many as three abnormalities found on sonography, and six (14%) of 44 patients had four or five sonographic findings of gallbladder abnormalities while in the ICU. No statistically significant correlation was found among any of these sonographic abnormalities and the clinical and laboratory parameters.

CONCLUSION

Gallbladder abnormalities are frequently seen on sonography in ICU patients, even if these patients are not suspected of having acalculous cholecystitis; therefore, sonography appears to be of limited value in diagnosing acalculous cholecystitis in ICU patients.

Models of local behavior of DNA electrophoresis peak parameters

Many base calling algorithms implicitly or explicitly rely on predictions of local sequence parameters such as amplitude, peak time and peak width. For example, an algorithm may search for the next peak about a predicted peak time formed by adding the mean peak separation to the last position measurement. In this paper, covariance models are presented which characterize the dependence of peak parameters on those of other peaks. Based on experimental measurements, the model features an exponential decay in peak time jitter covariance with respect to base separation. Both peak amplitude and peak width are modelled as being uncorrelated with those of adjacent bases. In the model, linear expressions are given to describe the growth in peak time jitter and peak width as a function of base position while other parameters, such as amplitude variance, are modeled by constants. Together, these results form a simple model which may be used in the derivation of new sequencing algorithms or in simulations for the testing of such algorithms. We suggest that the correlation of the peak times is related to the Kuhn length of the single-stranded DNA fragments.

GLUT1 glucose transporter expression in colorectal carcinoma: a marker for poor prognosis

BACKGROUND

Malignant cells exhibit increased glycolytic metabolism, and in many cases increased glucose transporter gene expression. The authors hypothesized that GLUT1 glucose transporter expression is increased in colorectal carcinoma, and that the degree of expression might have prognostic significance.

METHODS

GLUT1 glucose transporter immunostaining was studied in normal colon and benign colon adenomas and in 112 colorectal carcinomas from patients for whom long term clinical outcome was known.

RESULTS

GLUT1 immunostaining was absent in normal colorectal epithelium and tubular adenomas, and absent or only weakly apparent in tubulovillous adenomas. The majority of carcinomas (101 of 112; 90%) had GLUT1 immunostaining. Tumors from 92 patients had low GLUT1 expression (< 50% of cells were GLUT1 positive) and 19 of these patients (21%) died of disease during follow-up. In contrast, tumors from 20 patients had high GLUT1 expression (> 50% of cells were GLUT1 positive) and 9 of these patients (45%) died of disease during follow-up. Disease specific mortality was greater in patients with high GLUT1 tumors (relative risk of 2.4; P=0.02). In a multivariate analysis to assess whether high GLUT1 staining correlated with increased mortality independently of Dukes stage, the risk of death from colon carcinoma in the group with high GLUT1 staining was 2.3 times that in the group with low GLUT1 staining, a difference that approached statistical significance (P=0.07).

CONCLUSIONS

GLUT1 glucose transporter expression is associated strongly with neoplastic progression in the colon, and assessment of the extent of GLUT1 immunostaining in colorectal carcinoma identifies patients with a poorer prognosis.

GLUT1 glucose transporter expression in colorectal carcinoma: a marker for poor prognosis

BACKGROUND

Malignant cells exhibit increased glycolytic metabolism, and in many cases increased glucose transporter gene expression. The authors hypothesized that GLUT1 glucose transporter expression is increased in colorectal carcinoma, and that the degree of expression might have prognostic significance.

METHODS

GLUT1 glucose transporter immunostaining was studied in normal colon and benign colon adenomas and in 112 colorectal carcinomas from patients for whom long term clinical outcome was known.

RESULTS

GLUT1 immunostaining was absent in normal colorectal epithelium and tubular adenomas, and absent or only weakly apparent in tubulovillous adenomas. The majority of carcinomas (101 of 112; 90%) had GLUT1 immunostaining. Tumors from 92 patients had low GLUT1 expression (< 50% of cells were GLUT1 positive) and 19 of these patients (21%) died of disease during follow-up. In contrast, tumors from 20 patients had high GLUT1 expression (> 50% of cells were GLUT1 positive) and 9 of these patients (45%) died of disease during follow-up. Disease specific mortality was greater in patients with high GLUT1 tumors (relative risk of 2.4; P=0.02). In a multivariate analysis to assess whether high GLUT1 staining correlated with increased mortality independently of Dukes stage, the risk of death from colon carcinoma in the group with high GLUT1 staining was 2.3 times that in the group with low GLUT1 staining, a difference that approached statistical significance (P=0.07).

CONCLUSIONS

GLUT1 glucose transporter expression is associated strongly with neoplastic progression in the colon, and assessment of the extent of GLUT1 immunostaining in colorectal carcinoma identifies patients with a poorer prognosis.

Mesenteric fibromatosis in Crohn's disease

We have seen two patients with Crohn's disease and mesenteric fibromatosis, the least common form of desmoid tumor. Although both gastrointestinal and nongastrointestinal tumors are relatively common in Crohn's disease, this type of tumor has not been seen in > 1,650 patients operated on for this condition. As the only common factor in the two male patients discussed in this article was previous intestinal resections, surgical trauma may be a predisposing factor in the occurrence of these desmoid tumors. We will continue to search for other examples in patients with Crohn's disease.

MR contrast material for vascular enhancement: value of superparamagnetic iron oxide

OBJECTIVE

The purpose of this study were to quantify abdominal vascular enhancement and to prove the feasibility of iron oxide-enhanced MR angiography in humans using three doses of superparamagnetic iron oxide agent AMI 227.

SUBJECTS AND METHODS

Sixteen patients randomly received either 0.8, 1.1, or 1.7 mg Fe/kg of ultrasmall superparamagnetic iron oxide agent AMI 227. T1-weighted breath-hold gradient-echo images were obtained before and 45 min after i.v. administration of AMI 227. Signal intensity was measured in the aorta, the inferior vena cava, the portal vein, and muscle on unenhanced and contrast-enhanced images. Signal-to-noise ratios and enhancement [(SNR after contrast-SNR before contrast) / SNR before contrast] were calculated. Vessels were visually graded before and after administration of AMI 227.

RESULTS

All vessels showed statistically significant enhancement 45 min. after administration of AMI 227 by both qualitative and quantitative measures (p < .001). There was no significant increase in noise or signal intensity of muscle after contrast material was administered. The amount of enhancement was not statistically significantly different among the three doses.

CONCLUSIONS

AMI 227, which is currently in phase III clinical trials, demonstrates significant vascular enhancement and may prove useful as an MR angiographic contrast agent.

Capital planning: investing in excellence

Graham Slater and Kate Del Bravo describe the priorities considered and work undertaken by SETRHA to develop its capital investment strategy. Although the underlying concepts are straightforward, it represents a significant development beyond traditional NHS approaches to planning, embraces the NHS market reforms, and has reduced capital aspirations for the same service objectives by some 300m pounds.

Management of chondrosarcoma including modular ceramic and alumina prosthetic replacement

Forty-one cases of chondrosarcoma from varying sites throughout the body, and treated exclusively by one of the authors (R.L.H.) from 1972 to 1990 were reviewed. The symptoms, signs, location of tumours, treatment and progress are presented. Particular attention was paid to modular bone replacement techniques. Excision and reconstruction of the bone or joint were carried out in 17 femora, five tibia and six humeri. Comparison between this method of management and other techniques is discussed. Titanium and alumina prostheses for the hip, femur, tibia, shoulder and humerus have been designed by the senior author. These are both inert and modular, and have been found to be superior to other methods of treatment in both function and cosmesis. They do not possess the same potential donor infection risks and other disadvantages of allograft replacement. Immediate postoperative weight bearing and mobilization are possible with these systems. The Huckstep prostheses allow for bony ingrowth into their porous coated alumina sleeves, spacers and stems. In addition, the titanium alloy locking component for the femoral stems has an elasticity half that of other metal alloys and this was found to minimize stress shielding.

Clinicopathologic correlations of ABO and Rhesus blood type in colorectal cancer

There is no specific association established between colorectal cancer and blood group type. In this study, the distribution of ABO and Rh blood groups was studied in 838 patients with colorectal cancer. There was no difference in distribution of ABO blood groups between patients who were Rh+ and Rh-. There was no difference in ABO blood group or Rh factor and tumor location. The highest A/O ratio was found in rectal cancer. Although there was no difference in stage distribution for each ABO blood group, there was a significant difference between the Rh+ and Rh- groups (P < 0.037). It is not clear, however, whether the prognosis is different between the two groups since there were more early tumors as well as incurable tumors in the Rh- group. All patients with synchronous cancer were Rh+. Further studies on blood group antigens are needed to elucidate the relationship between these antigens and colorectal cancer.

Small bowel length in Crohn's disease

The length of the small intestine in patients with Crohn's disease who are referred for surgery has not been well studied. In this report, 25 patients with Crohn's disease who were being operated on for the first time had their small intestine measured at the time of surgery. The mean length of small intestine in this group was 501 cm, which was not different from a group of patients without Crohn's disease who were being operated on for other problems. In the group of patients with Crohn's disease, as well as the entire group, there was a correlation between increasing height and longer small bowel length. No other parameters investigated, including weight, surface area, age, sex, and duration of disease, correlated with bowel length. The results of this study are somewhat encouraging to patients with Crohn's disease, since these patients do not start off with a shortened bowel prior to surgery.

Synchronous carcinoma of the colon and rectum

Reports on the incidence of synchronous carcinoma of the colon and rectum have varied from 2 to 11 per cent. The variability is a result of a lack of uniformity in criteria of diagnosis, differences in the population studied and differences in time period used. In this study, we evaluated the incidence and distribution of synchronous lesions during a recent time period before the use of colonoscopy became widespread. We reviewed the records of all patients with newly diagnosed adenocarcinoma of the colon and rectum who were operated upon at our institution between 1976 and 1981. In a total group of 1,000 patients of which 52 per cent were men, there were 54 patients or 5.4 per cent who had synchronous carcinomas. The group of patients with synchronous carcinomas were older than the group with nonsynchronous carcinomas (72.4 versus 68.8 years). There was also a higher incidence of associated benign polyps in the group with synchronous carcinomas (70 versus 30 per cent for a nonsynchronous carcinomas). The anatomic distribution of carcinomas of the colon and rectum in the group with synchronous lesions (111 in total) revealed a higher percentage of carcinomas located on the right side (29.7 versus 22.5 per cent), although the difference did not reach statistical significance. Synchronous carcinomas were located in nonadjacent segments of the colon in 37 per cent. There was no difference in stage between the groups with and without synchronous carcinomas. The preoperative identification of synchronous lesions by either colonoscopy or barium enema is important for the proper treatment of patients with carcinoma of the colon and rectum. Failure to locate these tumors may lead to the demise of the patient.

Ultrasonic mucosal proctectomy in patients with ulcerative colitis

A technique for performing mucosal proctectomy in patients with ulcerative colitis using ultrasonic fragmentation is described. Twenty-eight patients undergoing colectomy and ileoanal anastomosis were studied. Removal of the mucosal layer of the distal rectum was performed using a titanium probe vibrating at 23 kHZ with an amplitude of 300 microns. This method produces complete mucosal destruction and the resulting debris and irrigating fluid is removed through the hollow central portion of the probe. Healing of the ileoanal anastomosis does not appear to be adversely affected by the use of this technique. Because ultrasonic fragmentation is not dependent on the integrity of the submucosal plane, it may be advantageous in those cases in which severe inflammation and submucosal scarring make manual dissection of the rectal mucosa difficult to perform.

Gastric fistulas in Crohn's disease. Report of cases

Nine cases of gastric fistula occurring in patients with Crohn's disease were treated at The Mount Sinai Hospital over the past three decades. Six cases were found in a review of 1480 patients with Crohn's disease admitted between 1960 and 1983. Three others seen at this institution outside the time frame of the author's study have also been included. Among six new cases, five with cologastric fistula occurred among 907 patients with Crohn's disease involving the colon (0.6 percent), while only one with ileogastric fistula was encountered among 1211 patients with ileal disease (0.08 percent). Fistulas between the stomach and colon always originated in an area of colitis, usually passing from distal transverse colon to greater curvature, but occasionally from midtransverse colon to antrum. The only pathognomonic clinical features were feculent vomiting, eructations, or odor. Diagnosis usually was made by barium enema or, less frequently, by upper gastrointestinal series; rarely, the gastric fistula was found unexpectedly at surgery. The conventional and recommended therapy is colectomy with wedge excision of the stomach. Medical treatment with 6-mercaptopurine has been completely successful in one patient and intermittently successful in a second patient.

Age and sex distribution of patients with colorectal cancer

A retrospective review of 922 colorectal cancer patients was undertaken to determine whether the nonuniform anatomic distribution of colorectal cancer was influenced by age and/or sex. The mean age of patients with right colon lesions (71.2 years) was significantly higher than for either patients with left colon lesions (68.2 years) or rectal lesions (65.6 years). Further analysis disclosed that patients with proximal tumors were older than patients with distal tumors primarily because of the later presentation of females with cecal or ascending colon cancers. Comparison of the anatomic distribution of tumors in patient groups above and below the age of 70 revealed that right colon cancers accounted for a greater percentage of colorectal tumors in the older patient group than in the younger patient group. These findings support the roles played by both age and sex in influencing colorectal cancer location. Furthermore, these data provide a plausible explanation for the increasing incidence of proximal colonic lesions.

In vivo formation of hydroxyl radicals following intragastric administration of ferrous salt in rats

Accidental poisoning by oral iron preparations is a serious problem in young children. We investigated the formation of hydroxyl radicals (.OH) in rats after intragastric instillation of ferrous sulfate. .OH was detected via its reaction with intragastrically administered 2-keto-4-methylthiobutyrate to generate ethylene gas. Ascorbic acid is typically present in oral iron preparations in order to facilitate absorption by maintaining iron in the reduced state. However, ascorbate possesses two properties that can affect .OH, recycling of oxidized iron to the ferrous state augments .OH production, while ascorbate in high concentration scavenges .OH. In experiments conducted in vitro, both actions were evident, depending upon the concentration of ascorbate. In parallel experiments conducted in vivo, the scavenging action of ascorbate was more prominent. Experiments in vitro with .OH-scavengers (dimethylsulfoxide, ethanol) and with the enzyme, catalase, confirmed both the presence of .OH and its dependence upon generated hydrogen peroxide during the oxidation of ferrous salt by molecular oxygen. Hydroxyl radicals (and/or reactive higher oxidation states of iron) may play a role in tissue damage after accidental overdose of oral iron.

Colorectal cancer location and synchronous adenomas

In this study, the relationship between the location of colorectal cancer and synchronous benign adenomas was assessed in 591 patients. Adenomas were found in 29.7% of all patients. Patients with cancer of the cecum, ascending colon, and hepatic flexure had the highest percentage of benign adenomas. Patients with right-sided cancer had adenomas in 47% of resected specimens, which percentage was significantly higher than that in the group of patients with left-sided cancer, who had adenomas in 22% of their specimens (p less than 0.001). Patients with cancer and synchronous adenomas were also older (70.2 vs 67.8, p less than 0.02) and more likely to be male (p less than 0.002) than patients with cancer and no adenomas. It is suggested that efforts be made to identify adenomas preoperatively in patients with colorectal cancer. In addition, since patients with cancer and associated adenomas are at increased risk of developing metachronous cancer, the group with right-sided cancer should be part of a particularly active surveillance program.

Production of ethane by rats treated with the colon carcinogen, 1,2-dimethylhydrazine

Ethane was exhaled by rats treated with the colon carcinogen, 1,2-dimethylhydrazine (DMH). At 1 hr, ethane production (mean +/- SD) was 0.2 +/- 0.2 nmol/kg (controls) and 5.2 +/- 1.3, 13.7 +/- 3.4, and 27.7 +/- 9.6, respectively, for DMH injections of 0.15 mmol/kg (20 mg/kg of the dihydrochloride salt), 0.45 mmol/kg, and 1.35 mmol/kg. Rates of ethane evolution tapered off after 2 hr, but persisted for up to 3 hr at the lower dose, and up to 5-6 hr at the higher dose. Although ethane is produced in vivo during lipid peroxidation, experiments with vitamin E, a potent lipid antioxidant, indicated that lipid peroxidation was unlikely to be the source of ethane in DMH-treated rats: pretreatment with vitamin E had no effect on ethane formation from DMH but did suppress ethane production from rats treated with carbon tetrachloride, an inducer of hepatic lipid peroxidation. When rats were injected with 1,2-diethylhydrazine in place of DMH, large amounts of ethane and ethylene were produced (9800 and 5600 nmol/kg/hr). The hydrocarbon gases exhaled by rats may arise from dimerization of methyl radicals (.CH3) generated during the metabolism of DMH, and from ethyl radicals (.CH2CH3) generated during the metabolism of 1,2-diethylhydrazine. Previously, it was shown that methane and ethane are formed from methyl radicals in vitro. Other investigators have observed formation of hydrocarbon gases during the in vitro metabolism of monoalkylhydrazines by microsomes, and ethyl radicals, derived from monoethylhydrazine, have been detected by electron spin-resonance spectroscopy. The results presented here suggest that in vivo metabolism of DMH may produce methyl radicals. Methyl radicals are capable of interacting with biomolecules. Their indiscriminate reaction with tissue constituents may be a contributory factor in DMH-induced carcinogenesis.

In vivo ethane production in vitamin E-deficient rats with DMH-induced colon cancer

The effect of both a vitamin E-deficient and a high polyunsaturated fat (PUFA) diet was tested on rats injected with the colon carcinogen 1,2-dimethylhydrazine (DMH). In vivo lipid peroxidation was monitored by measuring exhaled ethane from the animals. Higher mean weights were found in animals fed high PUFA and vitamin E-sufficient diets. There was no difference in ethane exhalation between DMH-treated and control animals regardless of diet. Mean ethane exhalation was highest in animals fed either vitamin E-deficient or high PUFA diets. There was no difference in tumor formation between the vitamin E-deficient and the vitamin E-sufficient groups. The high PUFA groups had more tumors than the low PUFA groups. Diet was shown to be the major factor affecting ethane exhalation. There was no evidence that vitamin E-deficiency promoted DMH-induced tumors or that DMH caused increased lipid peroxidation.

A comparison of multiple synchronous colorectal cancer in ulcerative colitis, familial polyposis coli, and de novo cancer

Multiple synchronous colorectal cancer (MSCC) among 1537 patients (69 with familial polyposis coli (FPC), 780 with ulcerative colitis (UC), and 685 with de novo colorectal (DNC) cancers) admitted to The Mount Sinai Hospital between 1945 and 1981 was tabulated. MSCC occurred in five of 24 cancer patients with FPC (21%), in 12 of 65 cancer patients with UC (18%), but in only 17 of 685 DNC patients (2.5%). The proportions of MSCC cases with more than two synchronous tumors were also much greater in the former two groups (UC 6/12 = 50%, FPC 3/5 = 60%) than in DNC (0/17 = 0%). Multiplicity of cancers is thus a distinguishing feature of UC and FPC. MSCC differed from solitary cancers by association with older age and more advanced stage at diagnosis in patients with FPC and by a rightward shift in anatomic distribution in all patients, especially those with FPC and UC.

Left ear suppression on verbal dichotic tests in patients with multiple sclerosis

Verbal dichotic listening tests employing nonsense consonant-vowel stimulus pairs were administered to 11 right-handed patients with chronic multiple sclerosis and to 10 right-handed normal controls. A highly significant reduction of left-ear scores was found in the multiple sclerosis group. We propose that the basis for this finding is a disconnection of the auditory callosal pathway and that dichotic listening tests may be of value in detecting the presence of lesions of the deep white matter of the cerebral hemispheres in multiple sclerosis.

Distribution of colorectal cancer in patients with and without ulcerative colitis

A comparison of the anatomic distribution of colorectal cancer in patients with and without CUC is difficult because of the unequal number of patients in each group and the changing epidemiologic parameters of colorectal cancer in general. In the present study, the distribution of colorectal tumors in patients with and without CUC was compared over two different time periods at a single hospital. In the early time period (1960 to 1975), there was a significantly higher percentage of proximal tumors in the group with cancer and CUC compared to the group with cancer alone. In the most recent time period (1975 to 1981), there was no difference in distribution of colorectal cancer regardless of whether the patient had CUC or not. We believe that the increased percentage of proximal tumors in patients with colorectal cancers and no CUC that has occurred in recent years has led to the present findings of a similar distribution of tumors in patients with and without CUC.

Laboratory evaluation of enoxacin: comparison with norfloxacin and nalidixic acid

Enoxacin displayed activity similar to that of norfloxacin against enterobacteria, Pseudomonas aeruginosa, staphylococci, streptococci and Bacteroides spp. The activity of enoxacin against many strains was reduced in acid conditions, but the pH effect was not so marked as that seen with norfloxacin. Nalidixic acid was found to be more active in acid conditions, particularly against staphylococci, Streptococcus faecalis and Ps. aeruginosa. In conditions simulating the treatment of bacterial cystitis, a single dose of enoxacin, achieving a peak concentration of 50 mg/l, suppressed growth of nalidixic acid-sensitive and -resistant Gram-negative bacilli for periods of between 18 and 25 X 5 h. Reduced susceptibility of bacteria surviving exposure to enoxacin was observed in one nalidixic acid-resistant strain of Escherichia coli and in nalidixic acid-sensitive strains exposed to low doses (peak concentration = 5 mg/l) of enoxacin. These results are similar to those obtained with norfloxacin and substantially better than those obtained with nalidixic acid.

Cholesterol, weight, height, Quetelet's index, and colon cancer recurrence

The association of low serum cholesterol with colon cancer mortality suggests that low serum cholesterol promotes colon cancer recurrence. We compared cumulative 5-year recurrence-free rates of 279 colon cancer patients in relation to serum cholesterol, weight, height, and Quetelet's index. The median value for each variable was used to divide patients into those above the median, or at the median and below. Patients with median and lower serum cholesterol exhibited an 11% lower disease-free rate at 5 years. Patients above median weight were at significantly increased risk of recurrence in both sexes (76 vs 54%, z = 3.0026, p = 0.003). Progressively decreasing weight was noted with advancing stage in males but not in females. Women above median Quetelet's index were also at significantly greater risk of recurrence (74 vs 52%, z = 2.6109, p = 0.009). Patients above median height were at insignificantly increased risk of recurrence. This study indicates that body weight is a significant prognostic factor for patients with colon cancer.