Imaging of perivascular adipose tissue in cardiometabolic diseases by Raman spectroscopy: Towards single-cell analysis

Perivascular adipose tissue (PVAT) has emerged as a dynamic organ influencing vascular function and cardiovascular health. In this brief review, an overview of the recent research in the investigation of PVAT is presented, ranging from in vivo studies to single-cell methodologies, in particular those based on Raman spectroscopy. The strengths and limitations of each, emphasizing their contributions to the current understanding of PVAT biology were discussed. Ultimately, the integration of these diverse methodologies promises to uncover new therapeutic targets and diagnostic biomarkers, including those emerging from simple Raman spectroscopy-based measurements of alterations in lipid unsaturation degree, invariably associated with PVAT dysfunction.

Direct oral and fiber-derived butyrate supplementation as an anti-obesity treatment via different targets

BACKGROUND & AIMS

Butyric (one of the short-chain fatty acids), a major byproduct of the fermentation of non-digestible carbohydrates (e.g. fiber), is supposed to have anti-obesity and anti-inflammatory properties. However, butyrate's potential and mechanism in preventing obesity and the efficient form of administration remain to be clarified.

METHODS

Hence, we studied the effect of oral supplementation with 5% (w/w) sodium butyrate and 4% (w/w) β-glucan (fiber) on young male mice (C57BL/6J) with high-fat diet-induced obesity (HFD: 60 kcal% of fat + 1% of cholesterol). Six weeks old mice were fed diets based on HFD or control (AIN-93G) diet with/without supplements for 4 weeks. The unique, interdisciplinary approach combining several Raman-based techniques (including Raman microscopy and fiber optic Raman spectroscopy) and next-generation sequencing was used to ex vivo analyze various depots of the adipose tissue (white, brown, perivascular) and gut microbiome, respectively.

RESULTS

The findings demonstrate that sodium butyrate more effectively prevent the pathological increase in body weight caused by elevated saturated fatty acids influx linked to a HFD in comparison to β-glucan, thereby entirely inhibiting diet-induced obesity. Moreover, butyrate significantly affects the white adipose tissue (WAT) reducing the epididymal WAT mass in comparison to HFD without supplements, and decreasing lipid saturation in the epididymal WAT and perivascular adipose tissue of the thoracic aorta. Contrarily, β-glucan significantly changes the composition and diversity of the gut microbiome, reversing the HFD effect, but shows no effect on the epididymal WAT mass and therefore the weight gain inhibition is not as effective as with sodium butyrate.

CONCLUSIONS

Here, oral supplementation with sodium butyrate and β-glucan (fiber) has been proven to have an anti-obesity effect through two different targets. Administration-dependent effects that butyrate imposes on the adipose tissue (oral administration) and microbiome (fiber-derived) make it a promising candidate for the personalized treatment of obesity.

Efficient delivery of carotenoids to adipocytes with albumin

Carotenoids are very effectively delivered by albumin to adipocytes. The uptake of carotenoids to the cells occurs in the form of self-aggregates that localize in the vicinity of the adipocyte membrane, as shown by high spatial resolution Raman spectroscopy. The binding of carotenoids to albumin and the mechanism of their transport were elucidated with the help of chiroptical spectroscopies, in tandem with molecular docking and molecular dynamics simulations. In particular, apart from the recognized high affinity pocket of albumin that binds a carotenoid monomer in domain I, we have identified a hydrophobic periphery area in domain IIIB that loosely bounds the self-aggregated carotenoid in aqueous media and enables its easy detachment in hydrophobic environments. This explains the effectiveness of albumins as nanocarriers of carotenoids to adipocytes in vitro.

Formation of carotenoid supramolecular aggregates in nanocarriers monitored via aggregation-sensitive chiroptical output of enantiopure (3S,3'S)-astaxanthin

The aggregation-sensitive chiroptical (ECD and RROA) output, provided by enantiopure (3S,3'S)-astaxanthin, was used to investigate and control the assembling processes of the carotenoid in Pluronic F-127 nanoparticles. The process of carotenoid J-aggregation inside nanocarriers is interfered with by the formation of kinetically stabilized H1 self-assemblies outside the micelles. Nanocarriers with encapsulated stable J-aggregates provide controlled release of carotenoid molecules to primary murine adipocytes.

Raman studies of the adipose tissue: Current state-of-art and future perspectives in diagnostics

The last decades revealed that the adipose tissue shows an unexplored therapeutic potential. In particular, targeting the perivascular adipose tissue (PVAT), that surrounds blood vessels, can prevent cardiovascular pathologies and browning of the adipose tissue can become an effective strategy against obesity. Therefore, new analytical tools are necessary to analyze this tissue. This review reports on the recent developments of various Raman-based techniques for the identification and quantification of the adipose tissue compared to conventional analytical methods. In particular, the emphasis is on analysis of PVAT, investigation of pathological changes of the adipose tissue in model systems and possibilities for its characterization in the clinical context. Overall, the review critically discusses the potential and limitations of Raman techniques in adipose tissue-targeted diagnostics and possible future anti-obesity therapies.

The distinct phenotype of primary adipocytes and adipocytes derived from stem cells of white adipose tissue as assessed by Raman and fluorescence imaging

Spectroscopy-based analysis of chemical composition of cells is a tool still scarcely used in biological sciences, although it provides unique information about the cell identity accessible in vivo and in situ. Through time-lapse spectroscopic monitoring of adipogenesis in brown and white adipose tissue-derived stem cells we have demonstrated that considerable chemical and functional changes occur along with cells differentiation and maturation, yet yielding mature adipocytes with a similar chemical composition, independent of the cellular origin (white or brown adipose tissue). However, in essence, these stem cell-derived adipocytes have a markedly different chemical composition compared to mature primary adipocytes. The consequences of this different chemical (and, hence, functional) identity have great importance in the context of selecting a suitable methodology for adipogenesis studies, particularly in obesity-related research.

Inadequate BCR-ABL monitoring in imatinib-treated patients with chronic myelogenous leukemia

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Background: Recommendations for baseline and quarterly measurement of the BCR-ABL fusion transcript to monitor imatinib response in patients with chronic myelogenous leukemia (CML) were formally introduced in October 2006, and have been incorporated into nationally recognized treatment guidelines. Methods: To assess BCR-ABL testing rates, we conducted a retrospective cohort analysis using a >10 million-member health plan database comprised of integrated pharmacy and medical claims. The study cohort was defined as patients with an index imatinib pharmacy claim from July 1, 2006, to December 31, 2006, who had a CML diagnosis (ICD-9 205.1X; N = 504), and a minimum of 3 months continuous follow-up by claims history (N = 465). Over a period of up to four quarters from the index imatinib prescription date, BCR-ABL testing in each quarter was assessed by the presence of any of a set of 19 CPT-4 codes. BCR-ABL testing rates in each individual quarter and in consecutive quarters were measured. Results: The overall study cohort was 57% male; mean (±SD) age was 52±14 y/o, with 26% 19–44 y/o, 57% 45–64 y/o, and 15% ≥65 y/o. Median duration of f/u was 559 days (interquartile range 302–628 days), and a cohort of 359 patients had 4 quarters of f/u. At least one BCR-ABL test was recorded in 60% of patients. The rate of first quarter BCR-ABL testing was 40%, and remained at 42%-43% in quarters 2 thru 4. Consecutive quarterly testing rates were 24% through the second quarter, 18% through the third quarter, and 14% through the fourth quarter. Conclusions: In this retrospective claims database analysis, only 14% of a large cohort of CML patients treated with imatinib had BCR-ABL testing recorded in each of 4 consecutive quarters. Inadequate compliance with recommended BCR-ABL testing can delay treatment decisions, and may be associated with poor clinical outcome.

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Variability and classification accuracy of serial high-sensitivity C-reactive protein measurements in healthy adults

BACKGROUND

Increased concentrations of high-sensitivity C-reactive protein (hs-CRP), a marker of systemic inflammation, are associated with increased risk for coronary heart disease. Because of its relationship to inflammation, hs-CRP has considerable biologic variation. This study was carried out to characterize CRP variation and to compare it to another risk factor, total serum cholesterol.

METHODS

One hundred thirteen individuals were scheduled to have five measurements each of hs-CRP and total cholesterol carried out at quarterly intervals over a 1-year period. Variations of hs-CRP and total cholesterol were characterized, and classification accuracy was described and compared for both.

RESULTS

The relative variation was comparable for hs-CRP and total cholesterol. When classified by quartile, 63% of first and second hs-CRP measurements were in agreement; for total cholesterol it was 60%. Ninety percent of hs-CRP measurements were within one quartile of each other. This relationship was not altered by the use of log-transformed hs-CRP data.

CONCLUSION

hs-CRP has a degree of measurement stability that is similar to that of total cholesterol.

Effect of physician-delivered nutrition counseling training and an office-support program on saturated fat intake, weight, and serum lipid measurements in a hyperlipidemic population: Worcester Area Trial for Counseling in Hyperlipidemia (WATCH)

OBJECTIVE

To evaluate the effectiveness of a training program for physician-delivered nutrition counseling, alone and in combination with an office-support program, on dietary fat intake, weight, and blood low-density lipoprotein cholesterol levels in patients with hyperlipidemia.

PARTICIPANTS AND METHODS

Forty-five primary care internists at the Fallon Community Health Plan, a central Massachusetts health maintenance organization, were randomized by site into 3 groups: (1) usual care; (2) physician nutrition counseling training; and (3) physician nutrition counseling training plus an office-support program. Eleven hundred sixty-two of their patients with blood total cholesterol levels in the highest 25th percentile, having previously scheduled physician visits, were recruited. Physicians in groups 2 and 3 attended a 3-hour training program on the use of brief patient-centered interactive counseling and the use of an office-support program that included in-office prompts, algorithms, and simple dietary assessment tools. Primary outcome measures included change at 1-year of follow-up in percentage of energy intake from saturated fat; weight; and blood low-density lipoprotein cholesterol levels.

RESULTS

Improvement was seen in all 3 primary outcome measures, but was limited to patients in group 3. Compared with group 1, patients in group 3 had average reductions of 1.1 percentage points in percent of energy from saturated fat (a 10.3% decrease) (P = .01); a reduction in weight of 2.3 kg (P<.001); and a decrease of 0.10 mmol/L (3.8 mg/dL) in low-density lipoprotein cholesterol level (P = .10). Average time for the initial counseling intervention in group 3 was 8.2 minutes, 5.5 minutes more than in the control group.

CONCLUSION

Brief supported physician nutrition counseling can produce beneficial changes in diet, weight, and blood lipids.

Comparison of visual estimate with digital caliper measurement of coronary artery stenosis

We compared visual estimate and digital caliper measurement of coronary stenoses, utilizing both a 50% and 70% diameter reduction as a definition of significance and both experienced angiographers and cardiology fellows as readers. Ten angiograms were interpreted twice, using the different methods, by four readers, two months apart. The angiograms were divided into 12 vessel segments. Stenoses were judged more severe by visual estimate in 11 segments. Seven of twelve segments had significant differences between readers using the visual estimate, but no significant differences were obtained using caliper measurements. Variability was highest for fellows using the visual method. Interobserver agreement was highest using the digital caliper and the 70% criteria. Intraobserver agreement was most dependent on the amount of time taken in film interpretation. The digital caliper appears to be preferable in interpreting angiograms, particularly for cardiology fellows.

Facial pattern differences in long-faced children and adults

Vertical facial morphology has traditionally been studied by examining subjects chosen because of open bite/overbite or mandibular plane angle. The underlying skeletal and dental morphology associated with clinical facial appearance of normal and vertically dysplastic children and adults has not been well documented. The purposes of this study were to (1) describe vertical facial morphology in long-, normal-, and short-faced children and long-faced and normal adults, and (2) identify morphologic factors associated with the clinical evaluation of long-faced and normal subjects. Forty-two children, 6 to 12 years old, and forty-two young adults with varied vertical facial types were examined clinically and separated into three vertical classifications: long, normal, or short face. Lateral cephalometric radiographs were obtained in natural head position and seven angular, eighteen linear, and six ratio measurements were made. Descriptive statistics were used to characterize all groups, and intergroup differences were compared using analysis of variance for the three child groups and the t test for the two adult groups. For both long-faced children and adults, anterior total face height, mandibular plane angle, gonial angle, and mandibulopalatal plane angle were significantly greater than normal. Ramus height was not significantly different from normal in the children, but there was a tendency for long-faced adults to have short rami. Excessive dentoalveolar development was evident in long-faced children but not in adults. Factors associated with the clinical identification of vertical dysplastic subjects were identified by a principal component analysis. For each component, a variable highly correlated with that component was selected.(ABSTRACT TRUNCATED AT 250 WORDS)

Accuracy of cancer death certificates and its effect on cancer mortality statistics

A study to determine the accuracy of cancer mortality data was done using cancer deaths occurring during 1970 and 1971 in eight of the nine areas included in the Third National Cancer Survey (TNCS). Death certificates with an underlying cause of death of cancer were compared to the hospital diagnosis for 48,826 resident cases of single primary cancers. The underlying cause of death as coded on the death certificate was found to be accurate for about 65 per cent of the cancer deaths in this study. Misclassification problems occurred for colorectal cancer, the second leading cause of death from cancer. Colon cancer was overreported and rectal cancer was under-reported on death certificates. Other misclassification problems were found for cancers of the uterus, brain, and buccal cavity including most of its sub-sites. Physicians tended to report a non-specific site of cancer on the death certificate rather than the specific site identified by the hospital diagnosis.