MRI and MRS of intact perfused cancer cell metabolism,invasion, and stromal cell interactions

Because of the spatial and temporal heterogeneities of cancers, technologies to investigate cancer cells and the consequences of their interactions with abnormal physiological environments, such as hypoxia and acidic extracellular pH, with stromal cells, and with the extracellular matrix, under controlled conditions, are valuable to gain insights into the functioning of cancers. These insights can lead to an understanding of why cancers invade and metastasize, and identify effective treatment strategies. Here we have provided an overview of the applications of MRI/MRS/MRSI to investigate intact perfused cancer cells, their metabolism and invasion, and their interactions with stromal cells and the extracellular matrix.     

Ocular prodrugs: Attributes and challenges

Ocular drug delivery is one of the most attention-grabbing and challenging endeavors among the numerous existing drug delivery systems. From a drug delivery point of view, eye is an intricate organ to investigate and explore. In spite of many limitations, advancements have been made with the intention of improving the residence time or permeation of the drug in the ocular region. Poor bioavailability of topically administered drugs is the major issue pertaining to ocular drug delivery. Several efforts have been made towards improving precorneal residence time and corneal penetration, e.g. iontophoresis, prodrugs and ion-pairing, etc. Prodrug approach (chemical approach) has been explored by the formulation scientists to optimize the physicochemical and biochemical properties of drug molecules for improving ocular bioavailability. Formulation of ocular prodrugs is a challenging task as they should exhibit optimum chemical stability as well as enzymatic liability so that they are converted into parent drug after administration at the desired pace. This review will encompass the concept of derivatization and recent academic and industrial advancements in the field of ocular prodrugs. The progression in prodrug designing holds a potential future for ophthalmic drug delivery.     

Computed tomography for occult fractures of the proximal femur,pelvis, and sacrum in clinical practice: single institution,dual-site experience

Purpose

The purpose of this study was to evaluate the diagnostic performance of CT for assessment of occult fractures of the proximal femur, pelvis, and sacrum.

Materials and methods

A retrospective review was performed on patients who received a CT of the hip or pelvis for suspected occult fracture after negative or equivocal radiographs performed within 24 h. The official radiology report was utilized for the determination of CT findings and calculation of sensitivity and specificity. Surgical reports, MRI reports, and clinical follow-up were used as the standard of reference. Sensitivity and specificity were calculated with 95% confidence intervals.

Results

Seventy-four patients received CT of the hip or pelvis for clinical concern for occult fracture after negative or equivocal radiographs. By the reference standard, a total of 40 fractures were present in 25/74 (33.8%) patients, including 35 conservatively treated fractures of the greater trochanter, pelvis, and sacrum, and 5 operatively treated proximal femoral fractures. A total of 14/74 (18.9%) of patients had an MRI within 1 day of CT. MRI identified an operatively treated femoral neck fracture not seen on CT and an operatively treated intertrochanteric fracture, which CT described as a greater trochanteric fracture. There were two false negative conservatively treated pelvic fractures not seen on CT but diagnosed on MRI. On a per-patient basis, CT had an overall sensitivity of 88% (22/25; 95% confidence intervals 69–97%), specificity of 98% (48/49; 95% confidence intervals 89–100%), and negative predictive value of 94%. For the five operative proximal femoral fractures, the sensitivity of CT was 60% (3/5; 95% confidence intervals 15–95%), specificity was 99% (68/69; 95% confidence intervals 92–100%), and negative predictive value was 97%.

Conclusions

In the clinical setting of suspected occult fracture, the sensitivity of clinical CT reports for detection of any type of fracture of the proximal femur, pelvis, or sacrum was 88%. For the small number of operatively treated proximal femoral fractures seen in the study, sensitivity of CT was 60% (3/5) and negative predictive value was 97%, although the relatively few patients needing fixation precludes statistical analysis.

     

Osteomyelitis of the lower extremity: pathophysiology,imaging, and classification,with an emphasis on diabetic foot infection

Osteomyelitis is inflammation of the bone caused by an infectious organism, and is a difficult clinical problem. The pathophysiology, imaging, and classification of osteomyelitis are challenging, varying with the age of the patient (child versus adult), the chronicity of the infection (acute versus chronic), and the route of spread (hematogenous versus contiguous focus), as well as the immune and vascular status of the patient and affected region. The two most common classification schemes are those of Lew and Waldvogel, and Cierny and Mader. Brodie’s abscess is seen in subacute osteomyelitis, while sequestrum, involucrum, and cloaca are inter-related entities of chronic osteomyelitis. Imaging workup of suspected osteomyelitis should begin with radiographs, although MRI is the most accurate imaging test. Three patterns of T1 signal change have been described in the setting of suspected osteomyelitis including confluent intramedullary, hazy reticular, and subcortical. The confluent intramedullary pattern is most associated with osteomyelitis, while hazy reticular is rarely associated with hematogenous osteomyelitis, and subcortical is not associated with osteomyelitis. It can be challenging to differentiate neuropathic arthropathy from osteomyelitis. Osteomyelitis tends to involve a single bone subjacent to an ulcer or sinus tract. In contrast, neuropathic arthropathy tends to involve multiple bones of the midfoot. Subchondral cystic change, thin rim enhancement of a joint effusion, and the presence of intra-articular bodies are more indicative of a neuropathic joint without infection. Biopsy can play an important role in diagnosis and treatment of osteomyelitis.     

Feeding Problems and Nutrient Intake in Children with and without Autism: A Comparative Study

Objective

To compare parent reported feeding difficulties and nutritional adequacy of children with Autism Spectrum Disorders (ASD) to an age and socio-economically matched group of typically developing children.

Methods

The scores on Children’s Eating Behavior Inventory (CEBI), three-day food records, anthropometric measures and adequacy of micro- and macro- nutrients were compared for 63 children diagnosed with ASD and 50 typically developing children enrolled from the department of pediatrics of a tertiary care teaching hospital from North India.

Results

The majority (79%) of the parents of ASD children reported some concern regarding their feeding behavior as compared to 64% of the parents of typically developing children. As compared to controls, ASD children had significantly higher CEBI scores (97.28 vs. 89.48, t = 3.15, P = 0.002) and more feeding problems (6.42 vs. 2.70, t = 3.74, P = 0.001). Relative to controls, ASD children consumed fewer number of food items (P = 0.022), particularly fruits (P = 0.004), vegetables (P = 0.011), and proteins (P = 0.015); had significantly lower daily intake of potassium (P = 0.001), copper (P = 0.007), and folate (P = 0.001). Although children with autism did not differ significantly from controls on intake of calories, height, weight, or body mass index, significantly greater proportion of ASD children failed to meet the estimated average requirement of thiamine (P = 0.039), vitamin C (P = 0.013), and copper (P = 0.005).

Conclusions

The findings underscore the need for comprehensive assessment and empirically-supported interventions for eating problems and dietary deficiencies found in ASD children.

     

Comparison of 300,000 and 600,000 IU Oral Vitamin-D Bolus for Vitamin-D Deficiency in Young Children

Objective

To compare the efficacy and safety of 300,000 and 600,000 IU vitamin-D single-oral dose for the treatment of vitamin-D deficiency (VDD) in young children (3 mo – 3 y).

Methods

This double-blind randomized control trial (Clinical Trail Registration-CTRI/2012/05/002621) was conducted in the Pediatric out-patient department (OPD) at a tertiary-care referral hospital. Children (3 mo – 3 y) with clinical/radiological features suggestive of VDD were screened; those found to be having 25(OH)D below 15 ng/ml and meeting inclusion and exclusion criteria’s were enrolled after taking informed consent. They were randomized into two groups, one receiving 600,000 and other 300,000 IU vitamin-D orally stat (Stoss-therapy). Primary outcome measure was proportion of children developing hypercalcemia/and hypercalciuria at day 7–10 post-therapy. Secondary outcome measures were proportion of children with hypercalciuria at day 3–5, hypercalcemia/and hypercalciuria at day 25–30 and 25(OH)D sufficiency at day 25–30 post-therapy.

Results

Sixty children, 30 in each group were randomized to two study groups. Baseline variables were comparable in two groups. Primary outcome measure (proportion of children with hypercalcemia/and hypercalciuria at 7 – 10th d) were 18.5 % (5/27) in 600,000 and 10.7 % (3/28) in 300,000 IU group (P = 0.47). Secondary outcome measures were - i) Proportion of children with hypercalciuria (3–5th d) were 18.5 % (5/27) in 600,000 and 7 % (2/28) in 300,000 group (P = 0.25). ii) Proportion of children with hypercalcemia/and hypercalciuria (25–30th d) were 18.5 % (5/27) in 600,000 and 11 % (3/28) in 300,000 group (P = 0.47). iii) All children in both groups had 25(OH)D levels in sufficiency range (25–30th d). With this sample size no significant difference in any of the group could be established.

Conclusions

The superiority of 300,000 over 600,000 IU vitamin-D single-dose oral therapy for VDD in children (3 mo – 3 y) in terms of safety could not be established with this sample size, although the prevalence of hypercalcemia/and hypercalciuria was observed more with 600,000 IU group. Both the regimens were effective for treating VDD at 25–30th d post-therapy.

     

Nanocarriers as treatment modalities for hypertension

Hypertension, a worldwide epidemic at present, is not a disease in itself rather it is an important risk factor for serious cardiovascular disorders including myocardial infarction, stroke, heart failure, and peripheral artery disease. Though numerous drugs acting via different mechanism of action are available in the market as conventional formulations for the treatment of hypertension but they face substantial challenges regarding their bioavailability, dosing and associated adverse effects which greatly limit their therapeutic efficacies. Various studies have demonstrated that nanocarriers can significantly increase the drug bioavailability thereby reducing the frequency of dosing in addition to minimizing toxicity associated with high dose of the drug. The present review provides an insight into the challenges associated with the conventional antihypertensive formulations and need for oral nanoparticulate systems in order to overcome problems associated with conventional formulations. Hypertension has circadian pattern of blood pressure, therefore chronotherapeutics can play a decisive role for the treatment, and however, nanoparticulate system can play major role in hypertension management. Future prospective for particulate nanocarriers in drug delivery for hypertension includes chronotherapeutics and emerging technique like gene therapy which is also covered in the review.     

Percutaneous Permeation Enhancement by Terpenes: Mechanistic View

A popular approach for improving transdermal drug delivery involves the use of penetration enhancers (sorption promoters or accelerants) which penetrate into skin to reversibly reduce the barrier resistance. The potential mechanisms of action of penetration enhancers include disruption of intercellular lipid and/or keratin domains and tight junctions. This results in enhanced drug partitioning into tissue, altered thermodynamic activity/solubility of drug etc. Synthetic chemicals (solvents, azones, pyrrolidones, surfactants etc.) generally used for this purpose are rapidly losing their value in transdermal patches due to reports of their absorption into the systemic circulation and subsequent possible toxic effect upon long term application. Terpenes are included in the list of Generally Recognized As Safe (GRAS) substances and have low irritancy potential. Their mechanism of percutaneous permeation enhancement involves increasing the solubility of drugs in skin lipids, disruption of lipid/protein organization and/or extraction of skin micro constituents that are responsible for maintenance of barrier status. Hence, they appear to offer great promise for use in transdermal formulations. This article is aimed at reviewing the mechanisms responsible for percutaneous permeation enhancement activity of terpenes, which shall foster their rational use in transdermal formulations.     

Sequence variations in TENM3 gene causing eye anomalies with intellectual disability: Expanding the phenotypic spectrum

Microphthalmia, anophthalmia are the malformations of the eye, referring to a congenital absence, and a reduced size of the eyeball. Coloboma of iris is associated with many of the cases. Here, we report a propositus with eye anomalies and intellectual disability associated with TENM3 pathogenic variations identified by exome sequencing and confirms intellectual disability as a phenotype associated with TENM3 variations. This child was compound heterozygote [NM_001080477.3(TENM3):c.4046C?>?G; p.(Ala1349Gly) and NM_001080477.3(TENM3): c.7687C?>?T; p.(Arg2563Trp)] for the missense likely pathogenic sequence variations in TENM3 gene. To our knowledge only three patients till now have been reported to have TENM3 pathogenic variations in association with microphthalmia, two siblings without developmental delay and third with developmental delay. This report supports the association of TENM3 variations with colobomatous microphthalmia and expands the phenotypic spectrum associated with pathogenic variations in this gene.     

APOE4 Affects Basal and NMDAR-Mediated Protein Synthesis in Neurons by Perturbing Calcium Homeostasis

Apolipoprotein E (APOE), one of the primary lipoproteins in the brain has three isoforms in humans, APOE2, APOE3, and APOE4. APOE4 is the most well-established risk factor increasing the predisposition for Alzheimer''s disease (AD). The presence of the APOE4 allele alone is shown to cause synaptic defects in neurons and recent studies have identified multiple pathways directly influenced by APOE4. However, the mechanisms underlying APOE4-induced synaptic dysfunction remain elusive. Here, we report that the acute exposure of primary cortical neurons or synaptoneurosomes to APOE4 leads to a significant decrease in global protein synthesis. Primary cortical neurons were derived from male and female embryos of Sprague Dawley (SD) rats or C57BL/6J mice. Synaptoneurosomes were prepared from P30 male SD rats. APOE4 treatment also abrogates the NMDA-mediated translation response indicating an alteration of synaptic signaling. Importantly, we demonstrate that both APOE3 and APOE4 generate a distinct translation response which is closely linked to their respective calcium signature. Acute exposure of neurons to APOE3 causes a short burst of calcium through NMDA receptors (NMDARs) leading to an initial decrease in protein synthesis which quickly recovers. Contrarily, APOE4 leads to a sustained increase in calcium levels by activating both NMDARs and L-type voltage-gated calcium channels (L-VGCCs), thereby causing sustained translation inhibition through eukaryotic translation elongation factor 2 (eEF2) phosphorylation, which in turn disrupts the NMDAR response. Thus, we show that APOE4 affects basal and activity-mediated protein synthesis responses in neurons by affecting calcium homeostasis.SIGNIFICANCE STATEMENT Defective protein synthesis has been shown as an early defect in familial Alzheimer''s disease (AD). However, this has not been studied in the context of sporadic AD, which constitutes the majority of cases. In our study, we show that Apolipoprotein E4 (APOE4), the predominant risk factor for AD, inhibits global protein synthesis in neurons. APOE4 also affects NMDA activity-mediated protein synthesis response, thus inhibiting synaptic translation. We also show that the defective protein synthesis mediated by APOE4 is closely linked to the perturbation of calcium homeostasis caused by APOE4 in neurons. Thus, we propose the dysregulation of protein synthesis as one of the possible molecular mechanisms to explain APOE4-mediated synaptic and cognitive defects. Hence, the study not only suggests an explanation for the APOE4-mediated predisposition to AD, it also bridges the gap in understanding APOE4-mediated pathology.