Impact of a hormone-releasing intrauterine system on the vaginal microbiome: a prospective baboon model

BACKGROUND

Use of a levonorgestrel-releasing intrauterine system (LNG-IUS) in humans may alter vaginal microbial populations and susceptibility to pathogens. This study evaluated the time-dependent effects of an LNG-IUS on the vaginal microbiome of the baboon, a useful animal model for reproductive studies.

METHODS

Levonorgestrel-releasing intrauterine systems were inserted into three reproductively mature, female baboons. The animals were evaluated for 6 months by physical examination and Gram-stained cytology. The vaginal microbiota was characterized at each timepoint by culture-independent analysis of the 16S rRNA-encoding gene.

RESULTS

Each baboon harbored a diverse vaginal microbiome. Interindividual variation exceeded intra-individual variation. Diversity declined over time in one baboon and showed mild fluctuations in the other two. There were no significant community differences from early to late post-LNG-IUS placement.

CONCLUSIONS

The baboon vaginal microbiome is unique to each individual and is polymicrobial. In this pilot study, the vaginal microbiome remained stable from early to late post-LNG-IUS placement.

A history of previous gestational diabetes mellitus is associated with adverse changes in insulin secretion and VLDL metabolism independently of increased intrahepatocellular lipid

AIMS/HYPOTHESIS

We have previously reported a high prevalence of non-alcoholic fatty liver disease (NAFLD) among women with previous gestational diabetes mellitus (pGDM). We wanted to confirm that intrahepatocellular lipid (IHCL) is associated with pGDM independently of adiposity and determine: (1) if VLDL metabolism is dysregulated; and (2) the extent to which NAFLD and IHCL account for the dysmetabolic phenotype in pGDM.

METHODS

We analysed data from a cohort of 234 women (114 with pGDM) and identified effects of pGDM on lipid and glucoregulation that were independent of ultrasound-diagnosed NAFLD. We then measured IHCL by MR spectroscopy in a representative subgroup (n = 36) and conducted detailed metabolic studies (IVGTT, VLDL apolipoprotein B [apoB] kinetics and palmitate turnover) and measurement of regional body fat by MRI to demonstrate effects of IHCL that were independent of a history of pGDM.

RESULTS

pGDM was associated with increased IHCL (p = 0.04) after adjustment for adiposity. Independently of IHCL, pGDM was associated with a lower IVGTT disposition index (p = 0.02) and acute insulin response to glucose (pGDM+/NAFLD-, 50% lower; pGDM+/NAFLD+, 36% lower; effect of pGDM, p = 0.03), increased VLDL apoB pool size (pGDM+/NAFLD-, 3.1-fold higher; pGDM+/NAFLD+, 1.2-fold higher; effect of pGDM, p = 0.02) and, at borderline significance (p = 0.05), increased rate of VLDL apoB synthesis.

CONCLUSIONS/INTERPRETATION

pGDM is associated with increased IHCL independently of adiposity. The increased liver fat contributes to the phenotype, but pGDM status is independently associated with diminished insulin secretion and (shown for the first time) augmented VLDL metabolism. IHCL with pGDM may compound a dysmetabolic phenotype.

Whole body fat: content and distribution

Obesity and its co-morbidities, including type II diabetes, insulin resistance and cardiovascular diseases, have become one of the biggest health issues of present times. The impact of obesity goes well beyond the individual and is so far-reaching that, if it continues unabated, it will cause havoc with the economies of most countries. In order to be able to fully understand the relationship between increased adiposity (obesity) and its co-morbidity, it has been necessary to develop proper methodology to accurately and reproducibly determine both body fat content and distribution, including ectopic fat depots. Magnetic Resonance Imaging (MRI) and Spectroscopy (MRS) have recently emerged as the gold-standard for accomplishing this task. Here, we will review the use of different MRI techniques currently being used to determine body fat content and distribution. We also discuss the pros and cons of MRS to determine ectopic fat depots in liver, muscle, pancreas and heart and compare these to emerging MRI techniques currently being put forward to create ectopic fat maps. Finally, we will discuss how MRI/MRS techniques are helping in changing the perception of what is healthy and what is normal and desirable body-fat content and distribution.

Adiposity in children and adolescents: correlates and clinical consequences of fat stored in specific body depots

The 2011 Pennington Biomedical Research Center's Scientific Symposium focused on adiposity in children and adolescents. The symposium was attended by 15 speakers and other invited experts. The specific objectives of the symposium were to (i) integrate the latest published and unpublished findings on the laboratory and clinical assessment of depot-specific adiposity in children and adolescents, (ii) understand the variation in depot-specific adiposity and related health outcomes associated with age, sex, maturation, ethnicity and other factors and (iii) identify opportunities for incorporating new markers of abdominal obesity into clinical practice guidelines for obesity in children and adolescents. This symposium provided an overview of important new advances in the field and identified directions for future research. The long-term goal of the symposium is to aid in the early identification of children and adolescents who are at increased health risk because of obesity and obesity-related conditions.

Novel genital alphapapillomaviruses in baboons (Papio hamadryas anubis) with cervical dysplasia

Genital Alphapapillomavirus (αPV) infections are one of the most common sexually transmitted human infections worldwide. Women infected with the highly oncogenic genital human papillomavirus (HPV) types 16 and 18 are at high risk for development of cervical cancer. Related oncogenic αPVs exist in rhesus and cynomolgus macaques. Here the authors identified 3 novel genital αPV types (PhPV1, PhPV2, PhPV3) by PCR in cervical samples from 6 of 15 (40%) wild-caught female Kenyan olive baboons (Papio hamadryas anubis). Eleven baboons had koilocytes in the cervix and vagina. Three baboons had dysplastic proliferative changes consistent with cervical squamous intraepithelial neoplasia (CIN). In 2 baboons with PCR-confirmed PhPV1, 1 had moderate (CIN2, n = 1) and 1 had low-grade (CIN1, n = 1) dysplasia. In 2 baboons with PCR-confirmed PhPV2, 1 had low-grade (CIN1, n = 1) dysplasia and the other had only koilocytes. Two baboons with PCR-confirmed PhPV3 had koilocytes only. PhPV1 and PhPV2 were closely related to oncogenic macaque and human αPVs. These findings suggest that αPV-infected baboons may be useful animal models for the pathogenesis, treatment, and prophylaxis of genital αPV neoplasia. Additionally, this discovery suggests that genital αPVs with oncogenic potential may infect a wider spectrum of non-human primate species than previously thought.

Relation between trunk fat volume and reduction of total lung capacity in obese men

Reduction in total lung capacity (TLC) in obese men is associated with restricted expansion of the thoracic cavity at full inflation. We hypothesized that thoracic expansion was reduced by the load imposed by increased total trunk fat volume or its distribution. Using MRI, we measured internal and subcutaneous trunk fat and total abdominal and thoracic volumes at full inflation in 14 obese men [mean age: 52.4 yr, body mass index (BMI): 38.8 (range: 36-44) kg/m(2)] and 7 control men [mean age: 50.1 yr, BMI: 25.0 (range: 22-27.5) kg/m(2)]. TLC was measured by multibreath helium dilution and was restricted (<80% of the predicted value) in six obese men (the OR subgroup). All measurements were made with subjects in the supine position. Mean total trunk fat volume was 16.65 (range: 12.6-21.8) liters in obese men and 6.98 (range: 3.0-10.8) liters in control men. Anthropometry and mean total trunk fat volumes were similar in OR men and obese men without restriction (the ON subgroup). Mean total intraabdominal volume was 9.41 liters in OR men and 11.15 liters in ON men. In obese men, reduced thoracic expansion at full inflation and restriction of TLC were not inversely related to a large volume of 1) intra-abdominal or total abdominal fat, 2) subcutaneous fat volume around the thorax, or 3) total trunk fat volume. In addition, trunk fat volumes in obese men were not inversely related to gas volume or estimated intrathoracic volume at supine functional residual capacity. In conclusion, this study failed to support the hypotheses that restriction of TLC or impaired expansion of the thorax at full inflation in middle-aged obese men was simply a consequence of a large abdominal volume or total trunk fat volume or its distribution.

The effects of a single cervical inoculation of Chlamydia trachomatis on the female reproductive tract of the baboon (Papio anubis)

BACKGROUND

The baboon (Papio hamadryas anubis) can be transcervically instrumented, facilitating studies of intrauterine contraception and reproductive tract infection. We sought to determine if the baboon could become infected with a single cervical inoculation of Chlamydia trachomatis.

METHODS

Ten female baboons were randomized and inoculated cervically with C. trachomatis serovar E (or buffer alone). Animals underwent weekly clinical and laparoscopic evaluations for four weeks and at post-inoculation week 8, to monitor upper tract infection. Cervical culture and nucleic acid amplification testing (NAAT) were completed weekly throughout the study. Animals were euthanized at week 16 and the reproductive tracts were examined histologically.

RESULTS

All inoculated animals developed cervical infection. The average duration of positive NAAT results was 6.8 weeks (range 2-16). Two of eight (25%) animals tested positive from fallopian tube samples. Infected animals showed histological findings consistent with chlamydial infection, such as germinal centers. Five of ten animals seroconverted to C. trachomatis.

CONCLUSIONS

Baboons cervically inoculated once with C. trachomatis develop infection similar to humans, with a low incidence of upper tract infection. This novel model of Chlamydia infection closely resembles human disease and opens new avenues for studying the pathogenesis of sexually transmitted infections and contraceptive safety.

Nonhuman primate models used to study pelvic inflammatory disease caused by Chlamydia trachomatis

Pelvic inflammatory disease (PID) is a global health concern that is associated with significant morbidity and is a major cause of infertility. Throughout history animals have been used for anatomical studies and later as models of human disease. In particular, nonhuman primates (NHPs) have permitted investigations of human disease in a biologically, physiologically, and anatomically similar system. The use of NHPs as human PID models has led to a greater understanding of the primary microorganisms that cause disease (e.g., Chlamydia trachomatis and Neisseria gonorroheae), the pathogenesis of infection and its complications, and the treatment of people with PID. This paper explores historical and contemporary aspects of NHP modeling of chlamydial PID, with an emphasis on advantages and limitations of this approach and future directions for this research.

Pragmatic study of orlistat 60 mg on abdominal obesity

BACKGROUND/OBJECTIVES

It is well established that combining a reduced calorie, low-fat diet with the lipase inhibitor orlistat results in significantly greater weight loss than placebo plus diet. This weight loss is accompanied by changes in adipose tissue (AT) distribution. As 60 mg orlistat is now available as an over-the-counter medication, the primary objective of this study was to determine whether 60 mg orlistat is effective as a weight loss option in a free-living community population with minimal professional input.

METHODS

AT and ectopic lipid content were measured using magnetic resonance imaging and (1)H MR spectroscopy, respectively, in 27 subjects following 3 months treatment with orlistat 60 mg and a reduced calorie, low-fat diet.

RESULTS

Significant reductions in intra-abdominal AT (-10.6%, P=0.023), subcutaneous (-11.7% P<0.0001) and pericardial fat (-9.8%, P=0.034) volumes and intrahepatocellular lipids (-43.3%, P=0.0003) were observed. These changes in body fat content and distribution were accompanied by improvements in plasma lipids and decreases in blood pressure and heart rate.

CONCLUSION

These findings suggest that over-the-counter 60 mg orlistat, in combination with the type of advice a subject could expect to be given when obtaining 60 mg orlistat in a community setting, does indeed result in potentially clinically beneficial changes in body composition and risk factors for metabolic diseases.

Treatment of early pregnancy failure: does induced abortion training affect later practices?

OBJECTIVE

The objective of the study was to examine the relationship between induced abortion training and views toward, and use of, office uterine evacuation and misoprostol in early pregnancy failure (EPF) care.

STUDY DESIGN

We surveyed 308 obstetrician-gynecologists on their knowledge and attitudes toward treatment options for EPF and previous training in office-based uterine evacuation.

RESULTS

Sixty-seven percent of respondents reported training in office uterine evacuation, and 20.3% reported induced abortion training. Induced abortion training was associated with strongly positive views toward both office-based uterine evacuation and misoprostol as treatment for EPF compared with those with office uterine evacuation training in other settings (odds ratio [OR], 2.64; P < .004 and OR, 3.22; P < .003, respectively). Furthermore, induced abortion training was associated with the use of office uterine evacuation for EPF treatment compared with those with office evacuation training in other settings (OR, 2.90; P = .004).

CONCLUSION

Training experiences, especially induced abortion training, are associated with the use of office uterine evacuation for EPF.

Peptide YY 3-36 and pancreatic polypeptide differentially regulate hypothalamic neuronal activity in mice in vivo as measured by manganese-enhanced magnetic resonance imaging

Peptide YY (PYY) and pancreatic polypeptide (PP) are two appetite suppressing hormones, released post-prandially from the ileum and pancreas, respectively. PYY(3-36) , the major circulating form of the peptide, is considered to reduce food intake in humans and rodents via high affinity binding to the auto-inhibitory neuropeptide Y receptor Y2R, whereas PP is considered to act through the Y4R. Current evidence indicates the anorexigenic effects of both peptides occur via signalling in the brainstem and arcuate nucleus (ARC) of the hypothalamus. Manganese-enhanced magnetic resonance imaging (MEMRI) has previously been used to track hypothalamic neuronal activity in vivo in response to both nutritional interventions and gut hormone treatment. In the present study, we used MEMRI to demonstrate that s.c. administration of PP results in a significant reduction in signal intensity (SI) in the ARC, ventromedial hypothalamus and paraventricular nucleus of fasted mice. Subcutaneous delivery of PYY(3-36) resulted in a nonsignificant trend towards decreased SI in the hypothalamus of fasted mice. We found no SI change in the area postrema of the brainstem after s.c. injection of either peptide. These differences in hypothalamic SI profile between PP and PYY(3-36) occurred despite both peptides producing a comparable reduction in food intake. These results suggest that separate central pathways control the anorexigenic response for PP and PYY(3-36) , possibly via a differential effect of Y4 receptor versus Y2 receptor signalling. In addition, we performed a series of MEMRI scans at 0-2, 2-4 and 4-6 h post-injection of PYY(3-36) and a potent analogue of the peptide; PYY(3-36) (LT). We recorded a significant reduction in the ARC SI 2-4 h after PYY(3-36) (LT) injection compared to both saline and PYY(3-36) in fasted mice. The physiological differences between PYY(3-36) and its analogue were also observed in the long-term effects on food intake, with PYY(3-36) (LT) producing a more sustained anorexigenic effect. These data suggest that MEMRI can be used to investigate the long-term effects of gut peptide delivery on activity within the hypothalamus and brainstem.

Resistant starch improves insulin sensitivity in metabolic syndrome

AIMS

Diets rich in non-viscous fibre are linked to a reduced risk of both diabetes and cardiovascular disease; however, the mechanism of action remains unclear. This study was undertaken to assess whether chronic consumption of this type of fibre in individuals with the metabolic syndrome would improve insulin sensitivity via changes in ectopic fat storage.

METHODS

The study was a single-blind, randomized, parallel nutritional intervention where 20 insulin resistant subjects consumed either the fibre supplement (resistant starch) (40 g/day) or placebo supplement (0 g/day) for 12 weeks. Insulin sensitivity was measured by euglycaemic-hyperinsulinaemic clamp and ectopic fat storage measured by whole-body magnetic resonance spectroscopy.

RESULTS

Resistant starch consumption did not significantly affect body weight, fat storage in muscle, liver or visceral depots. There was also no change with resistant starch feeding on vascular function or markers of inflammation. However, in subjects randomized to consume the resistant starch, insulin sensitivity improved compared with the placebo group (P = 0.023). Insulin sensitivity correlated significantly with changes in waist circumference and fat storage in tibialis muscle and to a lesser extent to visceral-to-subcutaneous abdominal adipose tissue ratio.

CONCLUSION

Consumption of resistant starch improves insulin sensitivity in subjects with the metabolic syndrome. Unlike in animal models, diabetes prevention does not appear to be directly related to changes in body adiposity, blood lipids or inflammatory markers. Further research to elucidate the mechanisms behind this change in insulin sensitivity in human subjects is required.

Peripherally injected cholecystokinin-induced neuronal activation is modified by dietary composition in mice

The aim of this study was to investigate the effect of long-term nutrient intake on the central response to the anorexigenic gut hormone CCK. C57BL/6 mice were fed one of three diets for 6 weeks: standard high carbohydrate (HC), high fat (HF), or high protein (HP). Assessment of brain response to cholecystokinin (CCK) by manganese-enhanced MRI (MEMRI) showed a reduction in neuronal activity both in an appetite-related area (ventromedial nucleus of the hypothalamus) and areas associated with reward (nucleus accumbens and striatum) regardless of diet. When comparing diet effects, while the HF diet did not induce any change in activity, reductions in MEMRI-associated signal were found in the paraventricular nucleus (PVN) and lateral hypothalamic area (LHA) when comparing the HP to the HC diet. In addition, a significant interaction was found between CCK administration and the HF diet, shown by an increased activation in the PVN, which suggests a decrease the inhibiting action of CCK. Our results put forward that the long-term intake of an HP diet leads to a reduction in basal hypothalamic activation while a high-fat diet leads to desensitization to CCK-induced effects in the hypothalamus.

Neonatal intrahepatocellular lipid

There is increasing evidence that preterm birth is a risk factor for the development of adiposity associated disease, although the pathophysiological basis is unclear. We have previously shown that preterm infants have increased internal abdominal (visceral) adiposity by term. In adults increased internal adiposity is associated with elevated intrahepatocellular lipid (IHCL). We measured IHCL using (1)H NMR spectroscopy in 26 infants (eight healthy preterm-at-term and 18 term-born) and compared values with a reference group of 32 adults. There was no significant difference between adult and term-born IHCL content. In preterm-at-term infants IHCL was significantly elevated when compared with term-born infants and with adults (IHCL CH2/water median (interquartile range): preterm 1.69 (1.04-3.53), term 0.21 (0-0.54) and adult 0.55 (0.08-1.57).

Exercise training reduces fatty acid availability and improves the insulin sensitivity of glucose metabolism

AIMS/HYPOTHESIS

It is not known whether the beneficial effects of exercise training on insulin sensitivity are due to changes in hepatic and peripheral insulin sensitivity or whether the changes in insulin sensitivity can be explained by adaptive changes in fatty acid metabolism, changes in visceral fat or changes in liver and muscle triacylglycerol content. We investigated the effects of 6 weeks of supervised exercise in sedentary men on these variables.

SUBJECTS AND METHODS

We randomised 17 sedentary overweight male subjects (age 50 +/- 2.6 years, BMI 27.6 +/- 0.5 kg/m(2)) to a 6-week exercise programme (n = 10) or control group (n = 7). The insulin sensitivity of palmitic acid production rate (Ra), glycerol Ra, endogenous glucose Ra (EGP), glucose uptake and glucose metabolic clearance rate were measured at 0 and 6 weeks with a two-step hyperinsulinaemic-euglycaemic clamp [step 1, 0.3 (low dose); step 2, 1.5 (high dose) mU kg(-1) min(-1)]. In the exercise group subjects were studied >72 h after the last training session. Liver and skeletal muscle triacylglycerol content was measured by magnetic resonance spectroscopy and visceral adipose tissue by cross-sectional computer tomography scanning.

RESULTS

After 6 weeks, fasting glycerol, palmitic acid Ra (p = 0.003, p = 0.042) and NEFA concentration (p = 0.005) were decreased in the exercise group with no change in the control group. The effects of low-dose insulin on EGP and of high-dose insulin on glucose uptake and metabolic clearance rate were enhanced in the exercise group but not in the control group (p = 0.026; p = 0.007 and p = 0.04). There was no change in muscle triacylglycerol and liver fat in either group.

CONCLUSIONS/INTERPRETATION

Decreased availability of circulating NEFA may contribute to the observed improvement in the insulin sensitivity of EGP and glucose uptake following 6 weeks of moderate exercise.

The first reported cases of disseminated histoplasmosis in Cambodia, complicated by multiple opportunistic infections

Although disseminated histoplasmosis is recognized as a common opportunistic infection in HIV-infected persons living in endemic areas, it is not widely reported in Southeast Asia, and has not been reported in Cambodia. It remains unanswered whether this is secondary to a low disease prevalence, or whether the disease, which is associated with a nonspecific clinical presentation, is under diagnosed. In addition to a review of the literature regarding histoplasmosis in Southeast Asia, we provide a description of two HIV-1 infected patients with documented disseminated histoplasmosis complicating other opportunistic infections in Phnom Penh, Cambodia. These two cases highlight the need for both a high clinical suspicion, and reliable laboratory testing, in a setting where there is likely to be more than one infection complicating the patient's clinical course.

Veterinary practice, competition and advertising: 1985-1994

In 1985, members of the veterinary profession and four other professional groups in New Zealand were surveyed to establish their attitudes towards the developing commercialisation of their professions, and particularly towards advertising. This survey was repeated in 1988, and again in 1994. The results of the three surveys are presented in this paper. There was a sharp movement towards acceptance of advertising, and toward a competitive orientation in general, between 1985 and 1988, with a consolidation of these changes during the following 6 years. The acceptance of the idea of an openly competitive profession now has widespread support among veterinarians. Similarly, there is general support for the use of most kinds of informative advertising, with many practitioners viewing advertising as a business building tool, but with the advertising of fees remaining an area over which there is still considerable caution. Although clients are seen as more demanding than in the past, the client-practitioner relationship is still expected to be an enduring one. We suggest that, in view of the relaxed attitudes towards advertising that now exists among members of the veterinary profession, control of advertising should cease to be a concern to the profession.

Formation of transient non-protein calcium pores by lysophospholipids in S49 Lymphoma cells

Palmitoyl-lysophosphatidylcholine promotes a transient calcium influx in lymphoma cells. Previously, it was observed that this influx was accompanied by a temporary increase in propidium iodide permeability that appeared linked to calcium entry. Those studies demonstrated that cobalt or nickel could block the response to lysophosphatidylcholine and raised the question of whether the calcium conductance involved specific channels. This communication describes a series of experiments to address that issue. The time dependence and structural specificity of the responses to lysophosphatidylcholine reinforced the hypothesis of a specific channel or transporter. Nevertheless, observations using patch clamp or calcium channel blockers suggested that this "channel" does not involve proteins. Alternative protein-mediated mechanisms such as indirect involvement of the sodium-calcium exchanger and the sodium-potassium ATPase were also excluded. Experiments with extracellular and intracellular calcium chelators suggested a common route of entry for calcium and propidium iodide. More directly, the ability of lysophosphatidylcholine to produce cobalt-sensitive permeability to propidium iodide was reproduced in protein-free artificial membranes. Finally, the transient nature of the calcium time course was rationalized quantitatively by the kinetics of lysophosphatidylcholine metabolism. These results suggest that physiological concentrations of lysophosphatidylcholine can directly produce membrane pores that mimic some of the properties of specific protein channels.

Adiposity induced by adenovirus 5 inoculation

OBJECTIVE

To investigate the effect of viral inoculation by adenovirus 5 (Ad5) on body composition in a mouse model.

DESIGN

Longitudinal monitoring before and after a single injection of virus or saline.

SUBJECTS

Two groups of CD1 mice, one group given a single intraperitoneal dose of Ad5 and the control group, saline.

MEASUREMENTS

Bodyweights and food intake were recorded before and up to 21 weeks after inoculation. At the end of the study, whole-body 1H magnetic resonance spectroscopy (MRS) and localised in vivo 1H MRS spectroscopy of the liver was performed to assess whole-body adiposity and intrahepatic lipid content, respectively.

RESULTS

Ad5-treated animals gained significantly more weight over a period of 21 weeks after inoculation than the controls, 21.8 g (18.8-25.0) and 18.8 g (17.3-19.8) respectively, (P<0.05). The gain in bodyweight in the former animals arises from increased deposition of adipose tissue as measured by whole-body 1H MRS. Adiposity was 6.7% (3.10-11.20%), and 2.40% (0.85-5.65%) for the Ad5-treated and control animals, respectively (P<0.05). No significant difference in intrahepatic lipid content or food intake was observed between the two groups.

CONCLUSION

The significantly higher percentage of adipose tissue in the Ad5-treated mice suggest viral infection may play a contributory role to a predisposition to obesity, although its contribution relative to other factors remains to be determined.

Muscle metabolites, detected in urine by proton spectroscopy, correlate with disease damage in juvenile idiopathic inflammatory myopathies

OBJECTIVE

To assess for novel markers of muscle damage using urinary muscle metabolites by 1H magnetic resonance spectroscopy in patients with juvenile idiopathic inflammatory myopathy (IIM).

METHODS

Creatine (Cr), choline (Cho), betaine (Bet), glycine (Gly), trimethylamine oxide (TMAO), and several other metabolites were measured in first morning void urine samples from 45 patients with juvenile IIM and from 35 healthy age-matched controls, and correlated with measures of myositis disease activity and damage. Urinary metabolite to age-adjusted creatinine (Cn) ratios were examined.

RESULTS

Age-adjusted initial Cr:Cn, Cho:Cn, Bet:Cn, Gly:Cn, and TMAO:Cn ratios were higher in patients with juvenile IIM than controls (P < 0.01). Cr:Cn ratios showed significant correlations with physician-assessed global disease damage (Spearman rs = 0.37; P = 0.01), Steinbrocker functional class (rs = 0.35; P = 0.02), serum Cr (rs = 0.72; P = 0.001), and lactate dehydrogenase (rs = 0.34; P = 0.03) levels. Cho:Cn (rs = 0.3; P = 0.05), Gly:Cn (rs = 0.33; P = 0.03), and TMAO:Cn (rs = 0.36; P = 0.02) ratios showed a significant correlation with serum aldolase levels. Cho:Cn ratios also showed a significant correlation with aspartate aminotransferase levels (rs = 0.35; P = 0.02). A linear regression model was used to evaluate the factors influencing urinary Cr:Cn ratios in the 43 patients with data sets available at the initial visit. The regression model explained 73% of the variation in Cr:Cn ratios. The most significant factor was the physician-assessed global disease damage (R2 = 0.50, P = 0.015).

CONCLUSION

Urinary Cr:Cn, Cho:Cn, Bet:Cn, Gly:Cn, and TMAO:Cn ratios are elevated in juvenile IIM and Cr:Cn correlates strongly with global disease damage. The Cr:Cn ratio may have potential utility as a marker of myositis disease damage.

Hepatic triglyceride content and its relation to body adiposity: a magnetic resonance imaging and proton magnetic resonance spectroscopy study

BACKGROUND

Hepatic steatosis is associated with obesity and type II diabetes. Proton magnetic resonance spectroscopy (1H MRS) is a non-invasive method for measurement of tissue fat content, including intrahepatocellular lipids (IHCL) and intramyocellular lipids (IMCL).

PATIENTS AND METHODS

We used 1H MRS and whole body magnetic resonance imaging (MRI) to assess the relationship between IHCL accumulation, total body adipose tissue (AT) content/distribution, and IMCL content in 11 subjects with biopsy proven hepatic steatosis and 23 normal volunteers.

RESULTS

IHCL signals were detectable in all subjects but were significantly greater in hepatic steatosis (geometric mean (GM) 11.5 (interquartile range (IQR) 7.0-39.0)) than in normal volunteers (GM 2.7 (IQR 0.7-9.3); p=0.02). In the study group as a whole, IHCL levels were significantly greater in overweight compared with lean subjects (body mass index (BMI) >25 kg/m2 (n=23): GM 7.7 (IQR 4.0-28.6) v BMI <25 kg/m2 (n=11): GM 1.3 (IQR 0.3-3.6; p=0.004)). There was a significant association between IHCL content and indices of overall obesity (expressed as a percentage of body weight) for total body fat (p=0.001), total subcutaneous AT (p=0.007), and central obesity (subcutaneous abdominal AT (p=0.001) and intra-abdominal AT (p=0.001)), after allowing for sex and age. No correlation between IHCL content and IMCL was observed. A significant correlation was observed between serum alanine aminotransferase and liver fat content (r=0.57, p=0.006).

CONCLUSIONS

Our results suggest that hepatic steatosis appears to be closely related to body adiposity, especially central obesity. MRS may be a useful method for monitoring IHCL in future interventional studies.

Veganism and its relationship with insulin resistance and intramyocellular lipid

OBJECTIVE

To test the hypothesis that dietary factors in the vegan diet lead to improved insulin sensitivity and lower intramyocellular lipid (IMCL) storage.

DESIGN

Case-control study.

SETTING

Imperial College School of Medicine, Hammersmith Hospital Campus, London, UK.

SUBJECTS

A total of 24 vegans and 25 omnivores participated in this study; three vegan subjects could not be matched therefore the matched results are shown for 21 vegans and 25 omnivores. The subjects were matched for gender, age and body mass index (BMI).

INTERVENTIONS

Full anthropometry, 7-day dietary assessment and physical activity levels were obtained. Insulin sensitivity (%S) and beta-cell function (%B) were determined using the homeostatic model assessment (HOMA). IMCL levels were determined using in vivo proton magnetic resonance spectroscopy; total body fat content was assessed by bioelectrical impedance.

RESULTS

There was no difference between the groups in sex, age, BMI, waist measurement, percentage body fat, activity levels and energy intake. Vegans had a significantly lower systolic blood pressure (-11.0 mmHg, CI -20.6 to -1.3, P=0.027) and higher dietary intake of carbohydrate (10.7%, CI 6.8-14.5, P<0.001), nonstarch polysaccharides (20.7 g, CI 15.8-25.6, P<0.001) and polyunsaturated fat (2.8%, CI 1.0-4.6, P=0.003), with a significantly lower glycaemic index (-3.7, CI -6.7 to -0.7, P=0.01). Also, vegans had lower fasting plasma triacylglycerol (-0.7 mmol/l, CI -0.9 to -0.4, P<0.001) and glucose (-0.4 mmol/l, CI -0.7 to -0.09, P=0.05) concentrations. There was no significant difference in HOMA %S but there was with HOMA %B (32.1%, CI 10.3-53.9, P=0.005), while IMCL levels were significantly lower in the soleus muscle (-9.7, CI -16.2 to -3.3, P=0.01).

CONCLUSION

Vegans have a food intake and a biochemical profile that will be expected to be cardioprotective, with lower IMCL accumulation and beta-cell protective.

Contrast enhancement of short T2 tissues using ultrashort TE (UTE) pulse sequences

AIM

To review the effects of contrast administration on tissues with short T2s using a pulse ultrashort echo time (UTE) sequence.

MATERIALS AND METHODS

Pulse sequences were implemented with echo times of 0.08 ms and three later gradient echoes. A fat-suppression option was used and later echo images were subtracted from the first echo image. Contrast enhancement with gadodiamide (0.3 mmol/kg) was used for serial studies in a volunteer. The images of 10 patients were reviewed for evidence of contrast enhancement in short T2 tissues.

RESULTS

Contrast enhancement was seen in normal meninges, falx, tendons, ligaments, menisci, periosteum and cortical bone. In addition more extensive enhancement than with conventional pulse sequences was seen in meningeal disease, intervertebral disc disease, periligamentous scar tissue and periosteum after fracture. Subtraction of an image taken with a longer TE from the first image was of value in differentiating enhancement in short T2 tissues from that in long T2 tissues or blood.

CONCLUSION

Contrast enhancement can be identified in tissues with short T2s using UTE pulse sequences in health and disease.