People living with HIV have low trabecular bone mineral density, high bone marrow adiposity, and poor trabecular bone microarchitecture at the proximal femur

People living with HIV (PLWH) have increased risk of osteoporosis and fractures. We assessed the proximal femur of PLWH and age-matched seronegative controls using quantitative computed tomography and magnetic resonance imaging. Results suggest that the trabecular compartment is compromised at fracture-prone regions in the proximal femur of PLWH.

INTRODUCTION

People living with HIV (PLWH) have increased risk of osteoporosis and fractures. However, studies assessing the main determinants of bone strength in the proximal femur exclude this vulnerable population. We assessed the proximal femur of 40 PLWH and 26 age-matched seronegative controls using quantitative computed tomography and magnetic resonance imaging.

METHODS

We examined cortical volumetric bone mineral density (Ct.vBMD), trabecular vBMD (Tb.vBMD), cortical thickness (Ct.Th), bone marrow adiposity (BMA), and trabecular number, separation, and bone volume fraction. Parametric comparisons between the two groups were made for the femoral head, femoral neck, trochanter, and total hip using linear regression adjusting for several covariates, including metrics of body composition. In addition, we investigated the associations of BMA with Tb.vBMD and trabecular microarchitecture with Spearman's rank partial correlations.

RESULTS

PLWH had lower Tb.vBMD and deteriorated trabecular microarchitecture in the femoral neck, trochanter and total hip, and elevated BMA in the femoral head, femoral neck, and total hip. Ct.vBMD and Ct.Th were not significantly different between the two groups. BMA was significantly associated with lower Tb.vBMD and deteriorated trabecular microarchitecture in both groups albeit at different femoral regions.

CONCLUSIONS

Our findings suggest that the trabecular, and not the cortical, compartment is compromised in the proximal femur of PLWH. The observed impairments in fracture-prone regions in PLWH indicate lower femoral strength and suggest higher fracture risk. The inverse associations of BMA with trabecular bone density and microarchitecture quality agree with findings at other anatomic sites and in other populations, suggesting that excess BMA possibly due to a switch from the osteoblast to the adipocyte lineage may be implicated in the pathogenesis of bone fragility at the femur in PLWH.

Control strategies of avian influenza pandemic model with time delay

A mathematical model for avian influenza with optimal control strategies is presented as a system of discrete time delay differential equations (DDEs) and its important mathematical features are analyzed. In alignment to manage this, we develop an optimally controlled pandemic model of avian influenza and insert a time delay with exponential factor. Then we apply two controlled functions in the form of biosecurity of poultry and the education campaign against avian influenza to control the disperse of the disease. Our optimal control strategies will minimize the number of contaminated humans and contaminated birds. We also derive the basic reproduction number to examine the dynamical behavior of the model and demonstrate the existence of the controlled system. For the justification of our work, we present numerical simulations.

Effect of concomitant vitamin D deficiency or insufficiency on lumbar spine volumetric bone mineral density and trabecular bone score in primary hyperparathyroidism

Lower vitamin D and higher parathyroid hormone (PTH) levels are associated with higher volumetric BMD and bone strength at the lumbar spine as measured by central quantitative computed tomography in primary hyperparathyroidism (PHPT), but there are no differences in bone microarchitecture as measured by trabecular bone score (TBS).

INTRODUCTION

The purpose of this study was to evaluate the association between 25-hydroxyvitamin D (25OHD) and volumetric bone mineral density (vBMD) and the TBS at the lumbar spine (LS) in PHPT.

METHODS

This is a cross-sectional analysis of PHPT patients with and without low 25OHD. We measured vBMD with quantitative computed tomography (cQCT) and TBS by dual-energy X-ray absorptiometry (DXA) at the LS in 52 and 88 participants, respectively.

RESULTS

In the cQCT cohort, those with lower vitamin D (<20 vs. 20-29 vs. ≥30 ng/ml) tended to be younger (p = 0.05), were less likely to use vitamin D supplementation (p < 0.01), and had better renal function (p = 0.03). Those with 25OHD <20 ng/ml had 80 and 126 % higher serum PTH levels respectively vs. those with 25OHD 20-29 ng/ml (p = 0.002) and 25OHD ≥30 ng/ml (p < 0.0001). Covariate-adjusted integral and trabecular vBMD were higher in those with 25OHD 20-29 vs. those with 25OHD ≥30 ng/ml, but those with 25OHD <20 did not differ. Because there were few participants with 25OHD deficiency, we also compared those with vitamin D <30 vs. ≥30 ng/ml. Covariate-adjusted integral and trabecular vBMD were 23 and 30 % higher respectively (both p < 0.05) in those with vitamin D <30 vs. ≥30 ng/ml. TBS was in the partially degraded range but did not differ by vitamin D status.

CONCLUSION

In mild PHPT, lower 25OHD is associated with higher PTH, but vitamin D deficiency and insufficiency using current clinical thresholds did not adversely affect lumbar spine skeletal health in PHPT. Further work is needed to determine if higher vBMD in those with lower vitamin D is due to an anabolic effect of PTH.

Thomas Eshelby (1769-1811), Nelson's Surgeon

Horatio Nelson is an icon of British naval history. His above-elbow amputation by Thomas Eshelby remains one of the most famous surgical procedures ever performed. Yet the surgeon himself remains relatively obscure and uncelebrated. We present a vignette of this young Yorkshireman and reflect on his life and times. Eshelby was a competent and conscientious surgeon and was certainly held in high regard by Nelson. Quite a few documents pertaining to his tour of duty in the Mediterranean and to his later appointment at Plymouth have been archived. These shed valuable light on his professional life, betraying his clinical acumen, his conscientious and pragmatic nature and his demeanour toward both his peers and his superiors. Eshelby was also the patriarch of an enterprising family including three generations of surgeons and others with eponymous discoveries in the fields of geography and science.

Novel anthropomorphic hip phantom corrects systemic interscanner differences in proximal femoral vBMD

Quantitative computed tomography (QCT) is increasingly used in osteoporosis studies to assess volumetric bone mineral density (vBMD), bone quality and strength. However, QCT is confronted by technical issues in the clinical research setting, such as potentially confounding effects of body size on vBMD measurements and lack of standard approaches to scanner cross-calibration, which affects measurements of vBMD in multicenter settings. In this study, we addressed systematic inter-scanner differences and subject-dependent body size errors using a novel anthropomorphic hip phantom, containing a calibration hip to estimate correction equations, and a contralateral test hip to assess the quality of the correction. We scanned this phantom on four different scanners and we applied phantom-derived corrections to in vivo images of 16 postmenopausal women scanned on two scanners. From the phantom study, we found that vBMD decreased with increasing phantom size in three of four scanners and that inter-scanner variations increased with increasing phantom size. In the in vivo study, we observed that inter-scanner corrections reduced systematic inter-scanner mean vBMD differences but that the inter-scanner precision error was still larger than expected from known intra-scanner precision measurements. In conclusion, inter-scanner corrections and body size influence should be considered when measuring vBMD from QCT images.

Accurate reconstruction of viral quasispecies spectra through improved estimation of strain richness

BACKGROUND

Estimating the number of different species (richness) in a mixed microbial population has been a main focus in metagenomic research. Existing methods of species richness estimation ride on the assumption that the reads in each assembled contig correspond to only one of the microbial genomes in the population. This assumption and the underlying probabilistic formulations of existing methods are not useful for quasispecies populations where the strains are highly genetically related.

RESULTS

On benchmark data sets, our estimation method provided accurate richness estimates (< 0.2 median estimation error) and improved the precision of ViQuaS by 2%-13% and F-score by 1%-9% without compromising the recall rates. We also demonstrate that our estimation method can be used to improve the precision and F-score of ShoRAH by 0%-7% and 0%-5% respectively.

CONCLUSIONS

The proposed probabilistic estimation method can be used to estimate the richness of viral populations with a quasispecies behavior and to improve the accuracy of the quasispecies spectra reconstructed by the existing methods ViQuaS and ShoRAH in the presence of a moderate level of technical sequencing errors.

AVAILABILITY

http://sourceforge.net/projects/viquas/.

Brucellosis and Coxiella burnetii Infection in Householders and Their Animals in Secure Villages in Herat Province, Afghanistan: A Cross-Sectional Study

Background

Brucellosis and coxiellosis are known to be endemic in ruminant populations throughout Afghanistan, but information about their prevalence and factors that affect prevalence in householders and livestock under diverse husbandry systems and pastoral settings is sparse.

Methods/Principal Findings

We conducted a cross-sectional survey to investigate the seroprevalence of brucellosis and Coxiella burnetii in humans and livestock in six secure districts in Herat from 26^th December 2012–17^th January 2013. A total of 204 households with livestock were surveyed in six Kuchi and five sedentary type villages. Blood samples from 1,017 humans, 1,143 sheep, 876 goats and 344 cattle were tested for brucellosis and Q fever. About one in six households (15.7%) had at least one Brucella seropositive person, about one in eight households (12.3%) had at least one Brucella seropositive animal and about one in four (24.5%) had either seropositive animals or humans. Ninety-seven percent of households had at least one C. burnetii seropositive person and 98.5% of households had one or more C. burnetii seropositive animals. Forty- seven householders had serological evidence of exposure to both C. burnetii and Brucella and eight animals were serologically positive for both diseases. Drinking unpasteurised milk (OR 1.6), treating animals for ticks (OR 1.4), milking sheep (OR 1.4), male gender (OR 1.4) and seropositivity to Brucella (OR 4.3) were identified as risk factors for seropositivity to C. burnetii in householders. Household factors associated with households having either Brucella seropositive animals or humans were Kuchi households (OR 2.5), having ≤4 rooms in the house (OR 2.9) and not owning land (OR 2.9).

Conclusions

The results from this study provide baseline information for the planning and monitoring of future interventions against these diseases. The implementation of this study greatly improved collaboration, coordination and capability of veterinary and public health professionals from government, NGOs and donor funded projects.

Our study alerted authorities to a hitherto unrecognised high prevalence of C. burnetii infections, acted as a catalyst for the introduction of a national vaccination programme for protection of sheep and goats from brucellosis using Rev1 vaccine, demonstrated the benefits of a coordinated approach and fostered a better understanding of the nature of infection in different hosts and of the constraints for control faced by government services. A notable feature of the study was the enthusiasm and interest displayed by all of the participants throughout, from heads of government services to field personnel and villagers. Livestock owners regard zoonoses as adversities that affect their livestock and members of their households and do not partition them separately as medical or veterinary problems. Control programs need to take that perception into account and wherever possible avoid vesting ownership separately into veterinary or public health agencies.

Volumetric bone mineral density at the spine and hip in Chinese American and White women

This study evaluated racial differences in bone size and volumetric density at the spine and hip in pre- and postmenopausal Chinese American and White women. Compared with White women, Chinese American women have greater cortical volumetric bone density (vBMD) at the hip, congruent with the results at the peripheral skeleton.

INTRODUCTION

Chinese American women have lower rates of fracture than White women despite lower areal bone density. At the forearm and tibia, however, Chinese American women have higher cortical vBMD as well as greater trabecular and cortical thickness, but smaller bone area as measured by high-resolution peripheral quantitative computed tomography (HR-pQCT) compared with White women. Since HR-pQCT data are obtained at peripheral sites, it is unclear whether these differences are relevant to the clinically important lumbar spine and hip. This study assesses racial differences in bone size and vBMD at the spine and hip in Chinese American and White women.

METHODS

QCT of the spine and hip was measured to assess racial differences in bone size, structure, and vBMD in pre- (n = 83) and postmenopausal (n = 50) Chinese American and White women. Data were adjusted for weight, height, physical activity, total calcium intake, parathyroid hormone, and 25-hydroxyvitamin D levels.

RESULTS

Among premenopausal women, lumbar spine trabecular vBMD was 5.8% greater in Chinese American versus White women (p = 0.01). At the hip, cortical vBMD was 3% greater at the femoral neck (p = 0.05) and 3.6% greater at the total hip (p = 0.01) in premenopausal Chinese American compared with White women. Among postmenopausal women, there was no difference in lumbar spine trabecular vBMD. Cortical vBMD was 4% greater at the total hip (p = 0.02) and tended to be greater at the femoral neck (p = 0.058) in Chinese American versus White women.

CONCLUSIONS

Consistent with earlier findings in the peripheral skeleton, cortical vBMD is greater at the hip in Chinese American versus White women.

Pelvic body composition measurements by quantitative computed tomography: association with recent hip fracture

INTRODUCTION

Loss of subcutaneous fat, decreased muscle cross-sectional area (CSA) and increased muscle adiposity are related to declining physical function and disability in the elderly, but there is little information about the relationship of these tissue changes to hip fracture. Thus we have compared body composition measures in women with hip fractures to age-matched controls, using quantitative computed tomography (QCT) imaging of the hip to characterize total adiposity, muscle CSA and muscle attenuation coefficient, a measure of adiposity.

MATERIALS AND METHODS

45 Chinese women (mean age 74.71+/-5.94) with hip fractures were compared to 66 healthy control subjects (mean age 70.70+/-4.66). Hip QCT scans were analyzed to compute total adipose CSA as well as CSA and attenuation values of muscle groups in the CT scan field of view, including hip extensors, abductors, adductors and flexors. The total femur areal BMD (aBMD) was estimated from the QCT images. Logistic regression was employed to compare body composition measures between fracture subjects and controls after adjustment for age, height, BMI and aBMD. Receiver-operator curve (ROC) analyses determined whether combinations of aBMD and body composition had higher area under curve (AUC) than aBMD alone.

RESULTS AND CONCLUSIONS

Fracture subjects had lower fat CSA (p<0.0001) than controls but had higher muscle adiposity as indicated by lower attenuation in the adductor, abductor and flexor groups (0.00001<p<0.02). Fracture subjects also had lower extensor and adductor CSA values (p<0.0001). After age and BMI adjustment, the total fat CSA, the extensor and adductor CSA values, and the adductor attenuation values remained significantly lower in the fracture subjects (0.001<p<0.05). In ROC analyses, models combining aBMD with soft tissue measures had higher AUC than models containing only BMD (0.001<p<0.05). Combining body composition with skeletal measures may improve fracture prediction compared to bone measures alone.

Helminths of red foxes (Vulpes vulpes) in Denmark

An epidemiological study of helminths in 1040 red foxes collected from various localities in Denmark during 1997-2002, revealed 21 helminth species at autopsy, including nine nematode species: Capillaria plica (prevalence 80.5%), Capillaria aerophila (74.1%), Crenosoma vulpis (17.4%), Angiostrongylus vasorum (48.6% from Northern Zealand (endemic area)), Toxocara canis (59.4%), Toxascaris leonina (0.6%), Uncinaria stenocephala (68.6%), Ancylostoma caninum (0.6%), and Trichuris vulpis (0.5%); seven cestodes: Mesocestoides sp. (35.6%), a number of Taeniid species (Taenia pisiformis, T. hydatigena, T. taeniaeformis, T. crassiceps, and unidentified Taenia spp.) (22.8%), and Echinococcus multilocularis (0.3%); four trematodes: Alaria alata (15.4%), Cryptocotyle lingua (23.8%), Pseudamphystomum truncatum (3.6% from Northern Zealand), and Echinochasmus perfoliatus (2.4% from Northern Zealand); one acanthocephalan: Polymorphus sp. (1.2%). Significant difference in prevalence was found for T. canis and A. vasorum according to host sex, and for T. canis, U. stenocephala, Mesocestoides sp., Taenia spp., A. alata, A. vasorum, and Capillaria spp. according to age groups (adult, young or cub). Prevalence and average worm intensity for each helminth species varied considerably according to geographical locality, season, and year. Aggregated distribution was found for several helminth species. The two species E. multilocularis and E. perfoliatus are first records for Denmark.

Zoonotic risk of Toxocara canis infection through consumption of pig or poultry viscera

The potential zoonotic risk of Toxocara canis infections from consumption of swine or poultry viscera containing larvae was assessed using a pig model. Two groups of six pigs were fed either fresh swine viscera (group FS) or poultry viscera (FP) containing around 3500 Toxocara larvae. Another two groups of six pigs were fed swine viscera (PS) or poultry viscera (PP) preserved at 4 degrees C for 1 week. All pigs were necropsied 14 days after the exposure. Liver white spots were counted and T. canis specific IgG antibodies were measured by ELISA. Larval burdens were assessed in the mesenteric lymph nodes, liver, lungs, brain, tongue, and eyes. All recipient pigs exhibited several white spots on the liver surface and detectable antibody levels. Larvae were recovered predominantly from the lungs, but also from the mesenteric lymph nodes and the liver, a few larvae were found in the brain and tongue of the pigs. Two larvae were found in the eyes of two pigs in group FS. Mean percentages of total larval recoveries in groups FS, FP, PS, and PP were 75.3, 63.6, 42.6, and 18.8%, respectively. Significantly higher numbers of larvae were recovered from pigs given swine viscera than pigs given poultry viscera. The preservation at 4 degrees C for 1 week caused a significant reduction in the larval infectivity overall, nevertheless, the recoveries remained substantial. The fact that larvae migrating in swine or poultry organs and tissues have high infectivity in pigs even after preservation at 4 degrees C for 1 week, suggests that human infection with T. canis might easily occur following consumption of raw or undercooked dishes, either fresh or refrigerated, prepared from swine or poultry organs and tissues harbouring T. canis larvae.

Population dynamics of Toxocara canis in pigs receiving a single or multiple infection

The population dynamics of Toxocara canis in pigs, and their immune response to a primary and a challenge infection, were studied by parasitological, haematological and serological parameters. Seventy pigs were divided into 4 groups; 35 pigs received a primary infection (group A), 15 pigs received both a primary and a challenge infection (group B), 15 pigs received the challenge infection only (group C), and 5 pigs served as helminth-free controls (group NC). A dose of 50,000 eggs was administered for the primary infection (day 0) and a dose of 10,000 eggs was given for the challenge infection (day 28). On days 7, 14, 21 and 28 p.i., 5 pigs of group A, and on days 35, 42 and 49 p.i., 5 pigs from each of groups A, B and C were necropsied. Numbers of recovered larvae varied widely among the 5 pigs of each group on all days of necropsy. Toxocara canis larvae were recovered predominantly from the lungs; migration of larvae to other organs or tissues from the lungs was restricted. In group A, the larval burden in the lungs peaked on day 14 p.i., and the larval densities decreased significantly over time. Thereafter, the majority of larvae were recovered from the lungs until the end of the experiment (day 49 p.i.). A few larvae were found in the muscles and brain until day 42 p.i., and 2 larvae were found in the eyes of 2 pigs on day 35 p.i. There was little evidence of protective immunity to a challenge infection in this experiment. The eosinophil levels tended not to increase in pigs receiving a challenge infection, in contrast to the challenge control pigs. The fact that T. canis larvae migrate and persist in the tissues of pigs for more than 1 month suggests a zoonotic risk in infected pigs. The relevance of these data to the population biology and immunology of porcine and human toxocarosis is discussed.

Impact of protein energy malnutrition on Trichuris suis infection in pigs concomitantly infected with Ascaris suum

The objective of this experiment was to investigate a possible interaction between protein and energy malnutrition (PEM) and intestinal nematode infections. We report on a 3 x 2 factorial study in which pigs were fed either a low protein energy (LPE), low protein (LP) or a normal protein energy (NPE) diet, and 6 weeks later inoculated with Trichuris suis (4000 infective eggs). Secondarily, in order to obtain a polyparasitic status, pigs were concomitantly inoculated with Ascaris suum (600 infective eggs). The number of T. suis-infected pigs was higher in LP pigs compared with NPE pigs (100 versus 58%; P = 0.037), although the differences in median T. suis worm burdens between groups at necropsy 10 weeks post-infection (p.i.) (LPE: 795; LP: 835; NPE: 48 worms; P = 0.33) were not significant. Interestingly, only T. suis in NPE were highly aggregated (k = 0.44), in contrast to a more uniform distribution among pigs in LPE (k = 1.43) and LP (k = 1.55) i.e. the majority of pigs harboured moderate worm burdens in LPE and LP, while most pigs had few or no worms in NPE. Further, T. suis worms in the LPE and LP groups were decreased in length (mean: LPE: 23.5 mm; LP: 24.3 mm; NPE: 29.4 mm; P = 0.004). The pre-patency period of T. suis was also extended in the LPE and LP groups, as reflected by lower faecal egg output at week 6 (P = 0.048) and/or 7 p.i. (P = 0.007). More A. suum worms were recovered from LP compared with the NPE group (mean: 5.4 versus 0.6; P = 0.040); this was accompanied by a higher faecal egg output in the former (P = 0.004). The low protein diets resulted in lower pig body weight gains, serum albumin, haemoglobin and packed cell volume (PCV) levels as well as diminished peripheral eosinophil counts. Infection significantly altered these parameters in the low protein groups, i.e. the pathophysiological consequences of infection were more severe in the PEM pigs. These results demonstrate that reduced protein in the diet leads to malnourishment of both the host pigs and T. suis, and compromises the pig's ability to resist infection by T. suis and A. suum.

Linking research and practice: participation of nurses in research to influence policy

In this article, the authors describe research conducted by the Pakistan Nursing Council (PNC) in Islamabad, Pakistan. The research was carried out through collaboration of two components of a large multicomponent Canadian International Development Agency (CIDA)-funded project--the Development of Women Health Professionals Program (DWHP)--with the Colleges of Nursing and the Pakistan Nursing Council. The research was guided by staff of the DWHP and performed by eight nurses undergoing a research course as part of a Diploma in Teaching Administration (DTA) at a postgraduate College of Nursing in the Northwest Frontier Province (NWFP), Pakistan. Research questions related to the collection and analysis of nursing workforce statistics were asked and partially answered, while students gained experience in conducting research. A description of the context in which the research was conducted is provided. Finally, results of the research and the potential benefits for influencing health workforce policy are discussed.

Host age influence on the intensity of experimental Trichuris suis infection in pigs

The impact of age-related resistance on the regulation of population dynamics of adult Trichuris suis was investigated in an experimental pig model. Helminth-naïve pigs varying in age from five weeks to four years were infected with T. suis to determine susceptibility to infection. Sows had a significantly lower establishment of adult T. suis worms compared with weaner pigs. Adult worm populations were highly overdispersed in both sows and grower pigs contrasted by a more even distribution among weaner pigs. Sows had significantly lower worm fecundities compared to weaner and grower pigs; T. suis from grower pigs, in turn, had reduced fecundity compared to worms in weaner pigs. In conclusion, we provide the first controlled experimental evidence that age-related resistance to T. suis occurs in pigs.

Subjective patient outcomes following coronary artery bypass using the radial artery: results of a cross-sectional survey of harvest site complications and quality of life

OBJECTIVES

To assess patient-based outcomes following radial artery harvesting for coronary artery bypass surgery (CABG).

METHODS

A cross-sectional telephone survey of 127 patients who underwent radial artery grafting was undertaken. The parameters assessed included symptoms related to the radial artery harvest site (functional impairment, sensory symptoms, and wound infection) and health related quality of life.

RESULTS

A high percentage of patients (67.7%) reported altered sensation, in the hand, in particular around the thenar eminence, in the forearm, or in relation to the incision; this was self-limiting and clinically insignificant in the vast majority of patients. Twelve patients reported residual insignificant symptoms after a median follow-up of 17.5 months. Four patients reported a subjective decrease in grip strength. Patients reported a good quality of life, and there was no association between this and the presence or absence of symptoms related to radial artery harvest. Some patients volunteered a 'preference' for the radial artery harvest site when compared with concomitantly harvested long saphenous vein (LSV), and there was a lower wound infection rate at radial artery harvest sites compared with vein harvest sites (6 vs. 15%).

CONCLUSIONS

Sensory symptoms following radial artery procurement occur more frequently than previously reported, but are largely self-limiting and are usually clinically insignificant. Patients appear to have a good quality of life following CABG using the radial artery. Radial artery harvest may be associated with lower wound infection rates and greater patient satisfaction than LSV harvest, however, the presence of residual sensory symptoms may be of relevance when obtaining informed consent.

Evaluation of a gel-coupled quantitative ultrasound device for bone status assessment

OBJECTIVE

To evaluate a new gel-coupled calcaneal quantitative ultrasound system, Osteospace (Medilink, Montpellier, France), which was designed to assess the status of bone in the calcaneus.

METHODS

The study group consisted of 215 healthy white women aged 20 to 85 years and 51 white women aged 60 to 86 years with osteoporotic fractures. Fifty-two healthy women aged 50 to 85 years were randomly selected from the healthy cohort as the control group. All the women had calcaneal quantitative ultrasonic measurements. The women with osteoporotic fractures and the control group also had proximal femur and lumbar anteroposterior spine bone mineral density measurements using dual X-ray absorptiometry. Bone mineral density was also measured in a subgroup of 54 women at the calcaneus.

RESULTS

There was a significant inverse correlation of broadband ultrasound attenuation and speed of sound with age (P < .001). Short-term measurement precision values expressed as coefficients of variation were 1.72% for broadband ultrasound attenuation and 0.64% for speed of sound, and standardized short-term precision values were 6.09% for broadband ultrasound attenuation and 3.87% for speed of sound. The correlations between the quantitative ultrasonic parameters and calcaneal bone mineral density were 0.69 (P = .0001) for broadband ultrasound attenuation and 0.45 (P = .0008) for speed of sound. Both quantitative ultrasonic parameters and all bone mineral density measurements of the hip and spine differed significantly between the control and osteoporotic fracture groups (P < .01). Age-, weight-, and height-adjusted odds ratios per SD decrease were as follows: broadband ultrasound attenuation, 1.79; speed of sound, 1.83; spine bone mineral density, 2.34; femoral neck bone mineral density, 1.69; and total hip bone mineral density, 1.85. The areas under the receiver operating characteristic curve for quantitative ultrasound parameters and bone mineral density measurements were close, ranging from 0.75 to 0.80.

CONCLUSIONS

This new quantitative ultrasound system can detect age- and menopause-related influences on skeletal status and can discriminate healthy women from those with osteoporotic fractures in a manner comparable with that of bone mineral density measurement by dual X-ray absorptiometry.

Assessment of bone status using speed of sound at multiple anatomical sites

Studies in vitro and in vivo have shown that quantitative ultrasound (QUS) is a valid tool for the assessment of bone status. Current QUS methods using the transmission technique are limited to one peripheral bone site. A new system, Sunlight Omnisense (Omnisense, Sunlight Medical Ltd., Rehovot, Israel), measures speed of sound (SOS, in m/s) along the surface of the bone based on an axial transmission technique. The Omnisense can measure SOS at several anatomical sites. This study evaluated the SOS at different anatomical sites in a healthy population. A total of 334 adult women from three research centers in the USA and Canada with a mean (+/- SD) age of 48.8 (+/- 17.4) years were enrolled in this study. SOS was measured at the proximal third phalanx, distal one third radius, midshaft tibia, and fifth metatarsal. The mean SOS (+/- SD) values for the phalanx, radius, tibia and metatarsal were 3984 (+/- 221), 4087 (+/- 147), 3893 (+/- 150) and 3690 (+/- 246) m/s, respectively. Each anatomical site SOS was significantly different (p < 0.001) from that of the other sites. SOS at the different anatomical sites was modestly, but significantly, correlated (r = 0.31 to 0.56, p < 0.001). Similar correlation coefficients were obtained for the T scores. The mean T scores for subjects over the age of 60 years were -1.94, -2.01, -0.97 and -1.42 for the phalanx, radius, tibia and metatarsal, respectively. The age of peak SOS and the rate of change thereafter varied with anatomical site, implying that the prevalence of osteopenia and osteoporosis was site-dependent if only one T score cut-off point was used. Comparing individuals, 10% to 17% of patients had T scores that differed by more than a factor of 2 between sites. Weight and age were some of the contributing factors to this heterogeneity. The Omnisense provides an opportunity to assess bone status at different anatomical sites. Whether or not combining measurements from all these anatomical sites will improve osteoporosis management still needs to be determined.

Marginal vitamin A deficiency in pigs experimentally infected with Trichuris suis: a model for vitamin A inadequacy in children

The development of an experimental model for marginal vitamin A deficiency in humans is of major interest, enabling the elucidation of possible interactions with helminth infections. We established a useful experimental model for human vitamin A deficiency in young pigs; deficiency was induced through a depletion method encompassing both sow and offspring. We report on a 2 x 2 study in which 18-week-old vitamin A deficient pigs and vitamin A sufficient littermates were infected with both of the intestinal nematodes Trichuris suis and Ascaris suum and followed for 14 weeks through 32 weeks of age. Forty-nine pigs were followed with respect to bodyweight, liver biopsies and blood samples for retinol concentration and faecal samples for parasite eggs and worms. Liver and serum concentrations of vitamin A were significantly diminished in the vitamin A deficient (VAD) group as compared to the vitamin A sufficient (VAS) group both before (P < 0.001) and after inoculation with T. suis and A. suum (P < 0.02). A significant correlation between retinol content in micro-biopsy needle samples and gross liver content was found (r = 0.457, n = 48, P = 0.001). The adult T. suis worms in the VAD group were marginally smaller (36.7 vs 40.2 mm; P = 0.08), more orally located (section 2.9 vs 3.9; P = 0.08) and had a higher proportion of males (0.58 vs 0.50; P = 0.08) whereas there were no effects of diet treatment on fecundity. The proportion of pigs with faecal T. suis egg excretion 12 weeks post inoculation (p.i.) was significantly lower in the VAD group compared with the VAS infected group (21 vs 78%; P = 0.036). In addition, faecal T. suis egg excretion was significantly lower in the VAD group at both week 11 (P = 0.040) and week 12 p.i. (P = 0.021). Vitamin A deficiency may have altered the functional integrity of the mucosal intestinal epithelium, disrupting the normally delicate attachment of T. suis and leading to the premature termination of infection. However, a possible antagonistic interaction, if verified, should not preclude interventions to improve vitamin A status, i.e., treatment should accompany anthelmintic treatment.

Acquired immunity to Trichuris suis infection in pigs

Strong resistance to reinfection developed in pigs as a result of trickle inoculations with Trichuris suis (250 infective eggs twice weekly for 4 weeks). At challenge (4000 eggs) 8 weeks after the last trickle inoculation, we observed a 96% reduction in the mean number of established challenge worms in immunized (TRI/CHA) compared with non-immunized controls (CON/CHA) (74 v. 1753; P = 0.004). Moreover, the total faecal egg excretion was significantly lower in immunized pigs compared with controls (P = 0.0003). The trickle inoculations depressed pig weight gains over the 8-week course of immunization (P = 0.042). It was observed that a small number of pigs developed a weaker level of resistance, reflecting the importance of genetic determinants. The relevance of these data to the population biology of porcine and human whipworm infections is discussed.

Effect of iron deficiency on Trichuris suis and Ascaris suum infections in pigs

The objective of this experiment was to detect a possible interaction between iron deficiency and intestinal nematode infections. We report on a 2 x 2 study where thirty-one 10-week-old pigs fed a low or a normal iron diet were infected with both Trichuris suis (4500 eggs) and Ascaris suum (1200 eggs). No significant difference was detected between diet groups with respect to parasitological parameters for A. suum or the total number of adult T. suis recovered at necropsy 10 weeks p.i. However, in the low iron group T. suis were located more proximally and the worms were increased in length. A higher proportion of pigs with initial faecal egg excretion at 6 weeks p.i. was observed in the low iron group, indicating a shortened pre-patency period. Worm fecundity and total faecal egg excretion were also highest in the low iron group. A significant correlation was found between female worm length and fecundity. The peripheral eosinophil counts were diminished in the low iron host groups. The infected low iron group experienced more severe pathophysiological changes in terms of hypoalbuminaemia and decreases in erythrocyte volumes. A significant inverse correlation existed between iron content in the bone-marrow and liver (body) store. In conclusion, iron deficiency increased the severity of T. suis infection in pigs.

Does routine use of the radial artery increase complexity or morbidity of coronary bypass surgery?

BACKGROUND

Despite increasing data supporting its use, the uptake of radial artery coronary bypass grafting by most surgeons remains low. This may partly be from perceptions that it increases risk or complexity of coronary surgery.

METHODS

Data on 151 patients who had radial grafts are compared with 179 concurrent nonrandomized controls that underwent conventional surgery using saphenous vein. Additionally, telephone interviews were conducted on 127 radial recipients to assess subjective outcome.

RESULTS

Cardiopulmonary bypass and cross-clamp times were similar in both groups (72 versus 74 minutes and 20 versus 22 minutes). Morbidity was comparable (mortality 1% versus 2%; cerebral vascular accident 1% versus 2%; sternal infection 1% versus 2%; resternotomy 4% versus 6%). Of 127 patients contacted, 41 (32%) reported that they had experienced parasthesia, and 65 (51%) reported numbness related to radial harvest; of these, 75% reported their symptoms as resolved or resolving. Early angiography performed in 36 patients revealed a radial patency rate of 92%.

CONCLUSIONS

Concerns about increased morbidity and mortality should not hinder adoption of radial artery grafting.

Optimization of the agar-gel method for isolation of migrating Ascaris suum larvae from the liver and lungs of pigs

Experiments on use of an agar-gel method for recovery of migrating Ascaris suum larvae from the liver and lungs of pigs were conducted to obtain fast standardized methods. Subsamples of blended tissues of pig liver and lungs were mixed with agar to a final concentration of 1% agar and the larvae allowed to migrate out of the agar-gel into 0.9% NaCl at 38 degrees C. The results showed that within 3 h more than 88% of the recoverable larvae migrated out of the liver agar-gel and more than 83% of the obtained larvae migrated out of the lung agar-gel. The larvae were subsequently available in a very clean suspension which reduced the sample counting time. Blending the liver for 60 sec in a commercial blender showed significantly higher larvae recovery than blending for 30 sec. Addition of gentamycin to reduce bacterial growth during incubation, glucose to increase larval motility during migration or ice to increase sedimentation of migrated larvae did not influence larvae recovery significantly.

Experimental infection of pigs with three dose levels of Trichuris suis

The objective of the study was to follow the course of Trichuris suis infection in pigs given infective eggs at low (400 eggs), medium (4,000 eggs) and high inoculation dose (40,000 eggs), respectively. Interestingly, despite a 100-fold difference in dose level no significant difference was found in either blood parameters, total faecal egg excretion, fecundity or worm burdens at necropsy 12 weeks post inoculation. The highest and lowest median faecal egg output was found in the medium and high dose group, respectively. With increasing dose level, worm size, establishment and prevalence of T. suis positive pigs decreased while worms were dislocated aborally. In addition there was a highly significant correlation between female worm burden and faecal egg excretion.

Epidemiology of Echinococcus granulosus in Arbil province, northern Iraq, 1990-1998

During the period 1990-1998, 99 cases of human cystic hydatidosis (12.4 cases per year) were surgically treated at the two main hospitals in Arbil province, northern Iraq, and from this the human occurence for the province was estimated to be 2 per 100,000 inhabitants. In the same area, 1270 sheep, 550 goats and 320 cattle were examined at slaughter for hydatid cysts and prevalence rates were found to be 15.0%, 6.2% and 10.9%, respectively. A decreasing tendency in livestock prevalences was found towards the end of the study period. As in humans, most of the hydatid cysts in livestock were located in the liver. Fertility of sheep cysts, i.e. those containing protoscoleces, was found to be significantly higher (64%) than that of goats (35.7%) and cattle (29.8%). The percentage of fertile cysts containing viable protoscoleces varied between 63 and 82% in the livers and between 72 and 79% in the lungs of the different animal species. A total of 97 stray dogs were examined post-mortem in the years 1991, 1992 and 1998, and Echinococcus granulosus worms were found in the intestines of 48 dogs (49.5%). High worm burdens (> 1000) were observed in 37% of the dogs, medium worm burdens (200-1000) in 41%, and low worm burdens (< 200) in 22%. In 1998, the prevalence of canine echinococcosis (24.3%) was found to be significantly lower than in 1991 (70.4%) and 1992 (60.6%). The prevalence of human hydatidosis did not differ significantly over the years, but the study confirmed that hydatidosis is endemic in northern Iraq, and that housewives, labourers and farmers appear to be at the greatest risk of infection.

Disease profile, complications and outcome in patients on maintenance haemodialysis at King Faisal University Hospital, Saudi Arabia

OBJECTIVE

To determine the primary renal disease, acute complications and long term outcome of patients with end stage renal disease(ESRD) undergoing maintenance haemodialysis (MHD).

DESIGN

A prospective descriptive study.

SETTING

King Faisal Hospital of the University, Al-Khobar, Saudi Arabia.

PATIENTS

Patients who had chronic renal failure with end stage renal disease (ESRD) and had been on regular dialysis for more than three months between September 1983 and September 1996 were included in the study. They were classified into three age groups, namely, group I comprising those aged below 29 years (48 patients); group II 30-59 years (147 patients), and group III, those aged 60 years and above (38 patients). Data were collected on disease characteristics, laboratory and radiological investigations, intra-dialytic complications and long-term outcome. The nature of renal disease was ascertained by review of medical data, clinical examination and laboratory investigations.

RESULTS

Two hundred and thirty-three patients with ESRD on MHD were studied. The major causes of ESRD were chronic glomerulonephritis (42.9%) and diabetic nephropathy (27.9%). Hypotension, the most frequent acute complication was seen in 27% of dialytic treatments. Long-term complications resulted mainly from the vascular access and included thrombosis (60 cases), infection (50 cases), haemorrhage from access sites (20 cases) and aneurysmal dilatation (13 cases). These were more frequent in diabetics. Survival in groups I, II and III were 95%, 84% and 27% respectively at the end of the study. The 53 (22.7%) deaths that occurred in the whole study population were mostly due to cerebrovascular accidents (24.5%), cardiovascular events (15.1%), pulmonary oedema and sepsis, each contributed 13.2% of the deaths.

CONCLUSION

In our patients with chronic renal failure on MHD, younger patients had better survival than the elderly. The main causes of death were cardiovascular and cerebrovascular diseases. Hypotension was the most frequent acute complication. Long-term complications were frequent, especially in diabetics.

Differential expression of adhesion molecules during rat small bowel allograft rejection

The adhesion molecules intercellular adhesion molecule 1 (ICAM-1), lymphocyte function-associated antigen-1 (LFA-1) (alpha and beta chains), and very late activation antigen-4 (VLA-4) have an essential role in cell-cell interactions and the initiation of immune responses. This study used an indirect immunoperoxidase technique to investigate the expression of these molecules in the lamina propria of allografts and isografts after heterotopic rat small bowel transplantation. Normal untransplanted small bowel served as additional controls. Overall, ICAM-1 and LFA-1 alpha expression was significantly higher in allografts, although there was variable expression of these molecules in isografted animals. There were temporal differences in the expression of ICAM-1 and LFA-1 alpha in that increased ICAM-1 expression was more pronounced in the the early posttransplant period, whereas there was a progressive increase in LFA-1 alpha as rejection developed. In contrast, there was no difference between allograft and isograft expression of LFA-1 beta and VLA-4. This study has demonstrated a preferential increase in adhesion molecule expression with developing rat small bowel allograft rejection and suggests that adhesion molecules are involved in the development and progression of allograft rejection. Although the observed differences in antigen expression are not as marked as those previously reported in other organ transplants, appropriate adhesion molecules may present suitable targets for immunotherapeutic protocols after small bowel transplantation.

Autosomal dominant polycystic kidney disease: observations from a university hospital in saudi arabia

Thirty cases of autosomal dominant polycystic kidney disease (ADPKD) seen at King Fahd Hospital of the University, Al-Khobar over a period of eight years, were analysed with respect to clinical features, laboratory investigations, radiological findings, complications and outcome. There were 13 males and 17 females with a mean age of 45 yrs + 10.1 (range 16-65 years). There was positive family history of renal disease in 17 cases. At the time of presentation, 27 cases had abdominal pain. The other features noted were hematuria (20 cases), polyuria (10 cases), urinary tract infection (22 cases), headache (9 cases), uremia (7 cases) and nephrolithiasis (5 cases). Bilaterally palpable kidneys were present in all cases. Hypertension (17 cases) was the next common clinical finding. Other clinical features noted were hepatomegaly (5 cases) and mitral valve prolapse (5 cases). Twenty-one patients had cysts in liver and five had cysts in spleen. Varying degrees of renal failure were seen in 15 cases. Six (20%) patients progressed to end stage renal disease during the period of observation.

Faecal enzymes: in vivo human skin irritation

Digestive enzymes in faeces have been reported to possess skin irritation potential. The present study was designed to investigate the in vivo irritant potentials of faecal concentrations of proteolytic and lipolytic digestive enzymes in bile salt mixtures. In a 21-day cumulative irritation assay, clinical evaluation and noninvasive bioengineering techniques were used. 5 days occlusive exposure to phosphate buffer (pH = 8) caused no visual skin damage but reflectance spectroscopy demonstrated significant vasodilation (p < 0.01) and increases in transepidermal water loss (TEWL) and skin pH were also observed (p < 0.01). These increases were still present at days 12 and 19. Occlusive exposure to physiologic concentrations of faecal enzymes resulted in significant visual and objective scores at day 5, 12, and 19, with increased readings as a function of exposure time (p < 0.01). The enzyme mixture containing lipase caused delayed onset of skin erythema and epidermal barrier disruption compared to elastase and chymotrypsin containing solutions. Prolonged occlusive exposure to digestive enzymes in faecal concentrations caused severe skin erythema and epidermal barrier disruption in a human model, suggesting a possible etiologic role of digestive enzymes in perianal, circumstomal or diaper dermatitis.

Multiple electrocardiographic anomalies during anaesthesia in an athlete

A 22-year-old athlete was scheduled for a minor surgical procedure under general anaesthesia. During anaesthesia, his electrocardiogram demonstrated multiple episodes of dysrhythmias including complete bundle branch block, atrioventricular (AV) block, isorhythmic atrioventricular dissociation with junctional rhythm. Administration of atropine 1.0 mg IV terminated the last episode of dysrhythmias. Postoperatively, a resting 12-lead electrocardiogram showed first degree AV block, ST-segment elevation and prominent U waves. A 24 hour Holter recording demonstrated first degree atrioventricular block, episodes of marked sinus arrhythmias and one episode of sinus tachycardia at a rate of 152 beats X min-1. Treadmill stress testing revealed peak achieved heart rate of 200 beats X min-1 without ischaemia. These findings collectively indicated athletic heart syndrome. Implications of athletic heart syndrome for the anaesthetist are reviewed and discussed.