Laser-irradiating infrared attenuated total reflection spectroscopy of articular cartilage: Potential and challenges for diagnosing osteoarthritis

Objective

A prototype infrared attenuated total reflection (IR-ATR) laser spectroscopic system designed for in vivo classification of human cartilage tissue according to its histological health status during arthroscopic surgery is presented. Prior to real-world in vivo applications, this so-called osteoarthritis (OA) scanner has been tested at in vitro conditions revealing the challenges associated with complex sample matrices and the accordingly obtained sparse spectral datasets.

Methods

In vitro studies on human knee cartilage samples at different contact pressures (i.e., 0.2-0.5 ​MPa) allowed recording cartilage degeneration characteristic IR signatures comparable to in vivo conditions with high temporal resolution. Afterwards, the cartilage samples were assessed based on the clinically acknowledged osteoarthritis cartilage histopathology assessment (OARSI) system and correlated with the obtained sparse IR data.

Results

Amide and carbohydrate signal behavior was observed to be almost identical between the obtained sparse IR data and previously measured FTIR data used for sparse partial least squares discriminant analysis (SPLSDA) to identify the spectral regions relevant to cartilage condition. Contact pressures between 0.3 and 0.4 ​MPa seem to provide the best sparse IR spectra for cylindrical (d ​= ​3 ​mm) probe tips.

Conclusion

Laser-irradiating IR-ATR spectroscopy is a promising analytical technique for future arthroscopic applications to differentiate healthy and osteoarthritic cartilage tissue. However, this study also revealed that the flexible connection between the laser-based analyzer and the arthroscopic ATR-probe via IR-transparent fiberoptic cables may affect the robustness of the obtained IR data and requires further improvements.

Long-term exposure to traffic-related air pollution and selected health outcomes: A systematic review and meta-analysis

The health effects of traffic-related air pollution (TRAP) continue to be of important public health interest. Following its well-cited 2010 critical review, the Health Effects Institute (HEI) appointed a new expert Panel to systematically evaluate the epidemiological evidence regarding the associations between long-term exposure to TRAP and selected adverse health outcomes. Health outcomes were selected based on evidence of causality for general air pollution (broader than TRAP) cited in authoritative reviews, relevance for public health and policy, and resources available. The Panel used a systematic approach to search the literature, select studies for inclusion in the review, assess study quality, summarize results, and reach conclusions about the confidence in the evidence. An extensive search was conducted of literature published between January 1980 and July 2019 on selected health outcomes. A new exposure framework was developed to determine whether a study was sufficiently specific to TRAP. In total, 353 studies were included in the review. Respiratory effects in children (118 studies) and birth outcomes (86 studies) were the most commonly studied outcomes. Fewer studies investigated cardiometabolic effects (57 studies), respiratory effects in adults (50 studies), and mortality (48 studies). The findings from the systematic review, meta-analyses, and evaluation of the quality of the studies and potential biases provided an overall high or moderate-to-high level of confidence in an association between long-term exposure to TRAP and the adverse health outcomes all-cause, circulatory, ischemic heart disease and lung cancer mortality, asthma onsetin chilldren and adults, and acute lower respiratory infections in children. The evidence was considered moderate, low or very low for the other selected outcomes. In light of the large number of people exposed to TRAP - both in and beyond the near-road environment - the Panel concluded that the overall high or moderate-to-high confidence in the evidence for an association between long-term exposure to TRAP and several adverse health outcomes indicates that exposures to TRAP remain an important public health concern and deserve greater attention from the public and from policymakers.

Machine learning augmented near-infrared spectroscopy: In vivo follow-up of cartilage defects

OBJECTIVE

To assess the potential of near-infrared spectroscopy (NIRS) for in vivo arthroscopic monitoring of cartilage defects.

METHOD

Sharp and blunt cartilage grooves were induced in the radiocarpal and intercarpal joints of Shetland ponies and monitored at baseline (0 weeks) and at three follow-up timepoints (11, 23, and 39 weeks) by measuring near-infrared spectra in vivo at and around the grooves. The animals were sacrificed after 39 weeks and the joints were harvested. Spectra were reacquired ex vivo to ensure reliability of in vivo measurements and for reference analyses. Additionally, cartilage thickness and instantaneous modulus were determined via computed tomography and mechanical testing, respectively. The relationship between the ex vivo spectra and cartilage reference properties was determined using convolutional neural network.

RESULTS

In an independent test set, the trained networks yielded significant correlations for cartilage thickness (ρ = 0.473) and instantaneous modulus (ρ = 0.498). These networks were used to predict the reference properties at baseline and at follow-up time points. In the radiocarpal joint, cartilage thickness increased significantly with both groove types after baseline and remained swollen. Additionally, at 39 weeks, a significant difference was observed in cartilage thickness between controls and sharp grooves. For the instantaneous modulus, a significant decrease was observed with both groove types in the radiocarpal joint from baseline to 23 and 39 weeks.

CONCLUSION

NIRS combined with machine learning enabled determination of cartilage properties in vivo, thereby providing longitudinal evaluation of post-intervention injury development. Additionally, radiocarpal joints were found more vulnerable to cartilage degeneration after damage than intercarpal joints.

Circulating tumour DNA is a potential biomarker for disease progression and response to targeted therapy in advanced thyroid cancer

BACKGROUND

Conventional biomarkers in thyroid cancer are not disease specific and fluctuate in advanced disease, making interpretation difficult. Circulating tumour DNA (ctDNA) has been shown to be a useful biomarker in other solid tumours. This is a multimutational study of ctDNA over multiple timepoints, designed to test the hypothesis that ctDNA is a potential biomarker in patients with advanced thyroid cancer.

METHODS

Mutational analysis of archival tumour tissue was performed using NGS with a targeted gene panel. Custom TaqMan assays were designed for plasma ctDNA testing using digital droplet polymerase chain reaction. Concentrations of detected ctDNA were correlated with the conventional biomarker concentration and axial imaging status defined by the Response Evaluation Criteria in Solid Tumours criteria.

RESULTS

Tumour tissue from 51 patients was obtained, with the following histologies: 32 differentiated (differentiated thyroid cancer [DTC]), 15 medullary (medullary thyroid cancer [MTC]), three poorly differentiated and one anaplastic. NGS analysis detected variants in 42 (82%) of cases. Plasma was assayed for these patients in 190 samples, and ctDNA was detected in 67% of patients. Earlier detection of disease progression was noted in three patients with MTC. In two cases (PTC and ATC), where conventional biomarkers were not detectable, ctDNA was detected before disease progression. Changes in ctDNA concentration occurred earlier than conventional markers in response to disease progression in multiple patients with DTC receiving targeted therapies.

CONCLUSION

The majority of patients with advanced thyroid cancer had detectable ctDNA. ctDNA measurement may offer superiority over conventional markers in several scenarios: earlier detection of progression in MTC; as an alternative biomarker when conventional markers are not available; more rapid assessment of the disease status in response to targeted therapies, thereby potentially allowing prompter discontinuation of futile therapies. These early results support the hypothesis that ctDNA may be a clinically useful biomarker in thyroid cancer.

Cerebral Venous Sinus Thrombosis: Unusual Imaging Appearance

Cerebral venous sinus thrombosis (CVST) has widely varied clinical and radiological manifestations ranging from asymptomatic minimal brain oedema to severe haemorrhagic infarcts associated with focal deficits, coma and even death. Cerebral venous sinus thrombosis presenting with lobar or subdural hematomas are rare and the cause may easily be overlooked. We present a case of CVST with an atypical radiological picture of intra-arenchymal, subdural and subarachnoid haemorrhage.

Callosal Holes: An Unusual Imaging Appearance in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) has diverse imaging features. However, focal lesions in the corpus callosum are extremely rare in SLE with only few cases mentioned in the literature, with no mention of callosal holes in SLE. Callosal holes have been described as a characteristic finding in Susac syndrome and have been mentioned in Nipah virus encephalitis, Marchiafava Bignami disease and periventricular leukomalacia. We describe a case of SLE with callosal holes. The demonstration of callosal holes in this case brings the imaging appearance of SLE a step closer to that of Susac syndrome which is considered a clinically and radiologically close condition. It also adds to the list of imaging appearances of central nervous system SLE.

Sample sizes for batch acceptance from single- and multistage designs using two-sided normal tolerance intervals with specified content

One quality control test in the pharmaceutical industry is a test for uniformity of content of a batch prior to release of the batch to market. For batch acceptance by this or other quantitative tests of batch quality, one approach uses two-sided tolerance intervals of specified content. If the tolerance interval falls entirely within an acceptance interval, the batch is accepted. This has the form of a statistical hypothesis test. Once we recognize this approach as a statistical test, we can ask what sample size is required to be able to accept the batch with a desired power. The power for a single-stage design is a bivariate noncentral t probability and can be determined using previously published algorithms. Using standard methods for interim analyses, the approach is extended to multistage designs. Power and sample size for multistage designs are validated with simulations. We demonstrate it is possible to design one- and two-stage designs for batch acceptance with desired power and specified type I level.

Delayed dental maturation in cleidocranial dysplasia

Cleidocranial dysplasia (CCD), a rare, inherited, generalized, skeletal and dental dysplasia, exhibiting an autosomal dominant mode of transmission, may be associated with delays during tooth maturation. To test whether permanent tooth formation is delayed in patients with CCD and if the presence of supernumerary teeth adversely influences maturation of the dentition, a group of CCD patients (eight females, three males) was compared to an equal number of control subjects matched for age and gender. Dental maturity was assessed using panoramic radiographs and the Dental Maturity Ratio, (DMR = mean dental age divided by the chronological age) was calculated. The mean DMR in CCD patients (0.87 +/- 0.14) was lower than in the control group (1.06 +/- 0.14), p < 0.01. Among patients with CCD, patients with supernumerary teeth, had a lower DMR (0.82 +/- 0.13 vs. 0.91 +/- 0.16), but the difference did not reach statistical significance. After adjusting for the presence of supernumerary teeth the diagnosis of CCD was still found to be associated with lower DMR than controls, p = 0.0569. We conclude that CCD patients have delayed tooth development of approximately 2.1 years and that among these patients, those with supernumerary teeth were further delayed by 1.5 years.

Proinflammatory cytokine release during pediatric cardiopulmonary bypass: influence of centrifugal and roller pumps

OBJECTIVE

It has been proposed that nonocclusive centrifugal pumps may elicit less blood cell trauma and hence a reduced inflammatory response than standard roller pumps. However, there have been no reports describing the impact of such pumps on proinflammatory cytokine release in pediatric cohorts.

DESIGN

A prospective randomized study was undertaken.

SETTING

A regional cardiothoracic center of a university hospital.

PARTICIPANTS

Thirty-four pediatric patients undergoing cardiopulmonary bypass (CPB) for the correction of complex congenital heart defects were recruited.

INTERVENTIONS

Either standard twin roller (n = 17), or centrifugal vortex (Biopump, Medtronic Biomedicus Inc, MN) (n = 17) blood pumping.

MEASUREMENTS AND MAIN RESULTS

Venous blood was drawn (1) on induction of anesthesia, (2) 5 minutes on bypass, (3) end of CPB, (4) 30 minutes post-protamine, (5) 2 hours and (6) 24 hours postoperation. Neutrophil count, level of plasma leukocyte elastase, terminal complement complex (C5b-9); interleukin-6 (IL-6) and interleukin-8 (IL-8) were increased during and after CPB compared with the postinduction baseline. C5b-9 levels in both groups peaked at the end of CPB before returning to baseline at 24 hours: (median [range]), 564 (16 to 1,136) ng/mL in centrifugal group versus 508 (0 to 1,128) ng/mL in the roller group. IL-6 in both groups reached its peak level at 2 hours postprotamine (208 [98 to 411] pg/mL in centrifugal versus 205 [60-327] pg/mL in the roller group), before coming back to baseline at 24 hours. Plasma leukocyte elastase and IL-8 reached their maximum level 15 minutes after protamine administration: 215 (64 to 375) pg/mL in centrifugal versus 235 (87 to 410) pg/mL in roller group; and 700 (90 to 5,925) ng/mL versus 362 (120 to 3,400) ng/mL, respectively.

CONCLUSIONS

The current study confirms the proinflammatory nature of pediatric CPB surgery, but failed to show a significant advantage of centrifugal pumping over roller perfusion in terms of the inflammatory response.

Acute renal failure of obstetrical origin during 1994 at one center

Although preventable, acute renal failure (ARF) of obstetrical origin continues to be common in developing countries. During the year 1994, we treated a total of 238 cases of ARE. Of these cases, 43 (18%) were of obstetrical origin. All of the patients were known to be previously healthy. Acute renal failure occurred in association with antepartum hemorrhage in 15, postpartum hemorrhage in 10, intrauterine death of fetus in 11, preeclampsia or eclampsia in 9, and septic abortions or puerperal sepsis in 7. Thirty-six patients required dialysis therapy because of moderate to severe azotemia. Renal histology was studied in 12 cases. Acute cortical necrosis was present in 9, extensive tubular necrosis in 2, and 1 patient had membranoproliferative glomerulonephritis. Twenty-two (51%) patients recovered normal renal function, while 11 (26%) developed irreversible renal dysfunction and 10 (23%) expired. Mortality and morbidity in this region is still quite high in obstetrical situations. Poor health infrastructure and lack of antenatal health clinics leads to development of major complications at the time of childbirth, which is mostly conducted at home by untrained personnel in quite a few cities of the country.

Microbial contamination of pharmaceutical preparations

Contamination of Pharmaceuticals with micro-organisms irrespective of being harmful or objectionable or nonpathogenic, can bring about changes in their physical characteristics, including the breaking of emulsions, the thinning of creams, Fermentation of syrups, and appearance of turbidity or deposit, besides producing possible off ordors and color changes.

An analysis of transformed clones obtained by coinfections with hr-t and ts-a mutants of polyoma virus

Clones of stably transformed rat cells from the F-111 (Fisher rat embryo) and NRK (normal rat kidney) cell lines have been obtained by complementation using pairs of nontransforming polyoma mutants of the hr-t and ts-a classes. A total of 78 clones were isolated and studied, 21 from the NRK line, and 57 from the F-111 line. These "complementation transformed clones" were then examined for the presence and expression of each of the parental mutant viruses. The expression of viral T (tumor) antigens was analyzed by immunoprecipitation. Every one of 54 clones examined express the 22K (small) and 56K (middle) T antigens which are the products of the hr-t viral gene. This indicates a requirement for the presence of a wild-type hr-t allele contributed by the ts-a mutant parent. Ten clones lack detectable large T antigen, while four show thermolabile large T antigen. These results support the conclusion that middle and small but not large T antigen(s) are essential for the maintenance of the transformed phenotype. Most of the 57 F-111 clones are virogenic when fused to mouse cells under permissive conditions and yield both mutant types. Surprisingly, wild-type recombinants have been recovered from 40 of the F-111 clones. Three clones show evidence of retention of only the ts-a mutant genome. Virus cannot be rescued from the majority of the 21 NRK clones. The few clones which are virogenic, however, yield both hr-t and ts-a mutants. Integration patterns of several clones analyzed by Southern blotting confirm the expectations based on viral T antigen(s) and virus rescue analyses. Hr-t mutant genomes, though not required for the maintenance of the transformed state, are frequently retained in complementation transformed clones. Tandem integration of the two parental mutants is clearly demonstrated in one clone and implicated in the other eight out of nine virogenic F-111 complementation transformed clones examined. This observation provides the basis of a model for the generation of wild-type recombinants following fusion of F-111 clones.

Induction of 7-ethoxycoumarin o-deethylase activity in cultured human epithelial cells by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD): evidence for TCDD receptor

The responsiveness of 5 human squamous cell carcinoma (SCC) lines derived from tumors of the epidermis and tongue to 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD) was assessed by measuring the induction of the cytochrome P1-450-mediated monooxygenase activity, 7-ethoxycoumarin O-deethylase (ECOD). In 4 of the SCC lines the EC50 for this response was approximately 10(-9)M, whereas in one line the EC50 was 10(-10)M. In each of the less sensitive lines a concentration of 10(-10)M TCDD elicited less than 5% of the maximal enzyme activity. Specific binding of radiolabeled TCDD was detected in the cytosol fraction from all the SCC lines. The relative amount of receptor measured in each line correlated with maximally-induced ECOD activity. The data indicate that human cell lines derived from a target tissue for TCDD toxicity contain the TCDD receptor and show differential sensitivity to TCDD analogous to the murine strain differences in sensitivity regulated by the Ah locus.