Thyroid cysts: a new extra-adrenal site of aldosterone synthase expression and increased aldosterone content

BACKGROUND: The rapid re-accumulation of fluid following aspiration of thyroid cystic lesions suggests that active transport of sodium and water may be involved in volume regulation of these lesions. In this study we address the possibility that aldosterone may take part in this process. SUBJECTS AND METHODS: Thirty-one patients (29 women and two men), with a mean age of 52.7 +/- 13.2 years (range: 27-77 years) underwent evaluation for thyroid nodules that had a sonographic cystic component. Cystic fluid obtained by FNA biopsy was sent for cytological examination and biochemical measurements. In 10 patients, material was collected for RNA extraction and determination of aldosterone synthase expression by RT-PCR amplification. RESULTS: All lesions were benign, cystic, colloid nodules. Cyst fluid aldosterone levels as measured by routine radioimmunoassay (RIA) were elevated above the normal plasma levels in all but five patients. Mean aldosterone levels were 27.1 +/- 22.9 ng/dl (SD) (range: 5.9-117.5 ng/dl). In contrast, cyst cortisol values were in the low, low normal serum range (6.2 +/- 2.9 microg/dl, range: 0.2-10.2 microg/dl). Sodium, chloride and potassium levels were 137 +/- 4.7 mEq/l, 98 +/- 5 mEq/l and 4.9 +/- 1.4 mEq/l, respectively. Plasma aldosterone levels were normal in all patients tested. To confirm these results, 12 samples were assayed after extraction and chromatography using a highly specific antibody. Cyst aldosterone levels in this group were elevated above the normal serum range in all but one patient (mean concentration: 24.5 +/- 14.6 ng/dl, range: 8.72-40.1 ng/dl). In this group, 18(OH)B levels were within the normal plasma range (12-55 ng/dl) in all but one patient (34.9 +/- 17 ng/dl). Furthermore, aldosterone synthase mRNA expression was found in aspirates of four of 10 patients. CONCLUSIONS: The increased aldosterone concentration and the presence of aldosterone synthase expression suggest that aldosterone may be locally produced and secreted in thyroid tissue. The pathophysiological implications of this finding remain to be established.     

A microfluidic traps system supporting prolonged culture of human embryonic stem cells aggregates

The unlimited proliferative and differentiative capacities of embryonic stem cells (ESCs) are tightly regulated by their microenvironment. Local concentrations of soluble factors, cell-cell interactions and extracellular matrix signaling are just a few variables that influence ESC fate. A common method employed to induce ESC differentiation involves the formation of cell aggregates called embryoid bodies (EBs), which recapitulate early stages of embryonic development. EBs are normally formed in suspension cultures, producing heterogeneously shaped and sized aggregates. The present study demonstrates the usage of a microfluidic traps system which supports prolonged EB culturing. The traps are uniquely designed to facilitate cell capture and aggregation while offering efficient gas/nutrients exchange. A finite element simulation is presented with emphasis on several aspects critical to appropriate design of such bioreactors for ESC culture. Finally, human ESC, mouse Nestin-GFP ESC and OCT4-EGFP ESCs were cultured using this technique and demonstrated extended viability for more than 5 days. In addition, EBs developed and maintained a polarized differentiation pattern, possibly as a result of the nutrient gradients imposed by the traps bioreactor. The novel microbioreactor presented here can enhance future embryogenesis research by offering tight control of culturing conditions.     

Low-dose ACTH (1 microg) salivary test: a potential alternative to the classical blood test

OBJECTIVES: Salivary cortisol is unaffected by cortisol binding globulin (CBG) and hence allows CBG-related variations in serum total cortisol to be bypassed. We assessed whether or not salivary cortisol can be used for the low-dose (1 microg) ACTH test in subjects with presumed normal and elevated levels of CBG. PATIENTS/METHODS: We measured serum and salivary cortisol responses to intravenous administration of 1 microg ACTH in 14 healthy volunteers, 14 'hyperoestrogenic' women [in their first or early second trimester of pregnancy, using oral contraceptives (OC) or on hormone replacement therapy (HRT)] and 10 patients with secondary hypoadrenalism. Cortisol levels were recorded before as well as 30 and 60 min (+30; +60 min) after ACTH administration. RESULTS: Baseline salivary cortisol did not differ significantly between the hypoadrenal and healthy patients (7.11+/-1.4 and 12.13+/-1.59 nmol/l; P=0.48) but there was a significant difference between hypoadrenal and hyperoestrogenic patients (18.94+/- 3.44 nmol/l; P=0.01). The largest difference between hypoadrenal patients and healthy individuals was observed at+30 min (9.16+/-2.8, 52.65+/-8.78 and 48.81+/- 6.9 nmol/l, in the hypoadrenal, healthy and hyperoestrogenic patients, respectively; P< 0.05). At this time-point values< 24.28 nmol/l were found in all hypoadrenal patients and cortisol levels >or= 27.6 nmol/l were found in 26 out of 28 healthy volunteers. ACTH-stimulated serum cortisol but not salivary cortisol was significantly higher in hyperoestrogenic women than in the healthy volunteers at either+30 or+60 min. CONCLUSIONS: The salivary low-dose ACTH test yields results that parallel the response of circulating cortisol to ACTH and may provide an alternative to the blood test, particularly in situations where increased CBG levels complicate the changes in serum cortisol levels.     

A flexible bioluminescent-quantitative polymerase chain reaction assay for analysis of competitive PCR amplicons

Aequorin-based flash-type bioluminescent methods can detect nucleic acid molecules in the attomolar range (10(-18)) enabling improved monitoring of the polymerase chain reaction (PCR) at cycles previously considered too low for product detection. The high sensitivity of bioluminescence (BL) was used to examine the efficiency of the PCR and to assess the effect of substrate variation during the linear phase of amplification. Primer efficiency was dependent on initial template concentration, in a manner indicative of a two-component reaction. However, the rate of amplicon formation was significantly impaired at low template levels and could not be overcome by excess primer. The PCR was directly dependent upon nucleotide concentration, which was independent of template concentration. Conditions were identified for optimal linear amplification and detection using BL. Accurate quantitative analysis was performed using competitive coamplification of a specific target standard sequence containing identical target primer recognition sites and novel internal sequences. Quantitation was most accurate when target molecule was similar in concentration to the internal standard. The Bioluminescent Quantitative-PCR (BLQ-PCR) assay has the potential to eliminate processing variability. We demonstrated high quantitative potential with a broad dynamic range. Overall, the BLQ-PCR assay is flexible and a viable alternative to contemporary Q-PCR techniques.     

Targeted anti-vascular endothelial growth factor receptor-2 therapy leads to short-term and long-term impairment of vascular function and increase in tumor hypoxia

Because antiangiogenic therapies inhibit the growth of new tumor-associated blood vessels, as well as prune newly formed vasculature, they would be expected to reduce the supply of oxygen and thus increase tumor hypoxia. However, it is not clear if antiangiogenic treatments lead only to consistent and sustained increases in hypoxia, or transient decreases in tumor hypoxia along with periods of increased hypoxia. We undertook a detailed analysis of an orthotopically transplanted human breast carcinoma (MDA-MB-231) over a 3-week treatment period using DC101, an anti-vascular endothelial growth factor receptor 2 antibody. We observed consistent reductions in microvascular density, blood flow (measured by high-frequency micro-ultrasound), and perfusion. These effects resulted in an increase in the hypoxic tumor fraction, measured with an exogenous marker, pimonidazole, concurrent with an elevation in hypoxia-inducible factor-1alpha expression, an endogenous marker. The increase in tumor hypoxia was evident within 5 days and remained so throughout the entire course of treatment. Vascular perfusion and flow were impaired at days 2, 5, 7, 8, 14, and 21 after the first injection, but not at 4 hours. A modest increase in the vessel maturation index was detected after the 3-week treatment period, but this was not accompanied by an improvement in vascular function. These results suggest that sustained hypoxia and impairment of vascular function can be two consistent consequences of antiangiogenic drug treatment. The implications of the results are discussed, particularly with respect to how they relate to different theories for the counterintuitive chemosensitizing effects of antiangiogenic drugs, even when hypoxia is increased.     

The Tat protein of the caprine arthritis encephalitis virus interacts with the Notch2 EGF-like repeats and the epithelin/granulin precursor

Using the yeast two-hybrid system, we screened a human placenta cDNA library and identified two proteins that interacted with the Tat protein of the caprine arthritis encephalitis virus (CAEV): the EGF-like repeats 1-6 of the extracellular domain of the human Notch2 receptor and the epithelin/granulin growth factor precursor. This interaction was also confirmed in mammalian cells. Using in vitro mutagenesis assays, we showed that each one of the three cysteine residues located within the cysteine-rich domain of the CAEV Tat protein is essential for the binding of Tat to both the Notch2 and the epithelin/granulin protein. It is thus suggested that the cysteine-rich domain of Tat plays a role in the interaction between the Tat and either Notch2 or the epithelin/granulin domains, both of which exhibit EGF-like-repeat-imposed spatial conformation. It is assumed that such interactions might modulate the physiological functions of Notch2 and epithelin/granulin, thereby affecting various pathologies associated with CAEV.     

MRI and fluorescence microscopy of the acute vascular response to VEGF165: vasodilation, hyper-permeability and lymphatic uptake, followed by rapid inactivation of the growth factor

Vascular endothelial growth factor (VEGF) is one of the key growth factors regulating tumor angiogenesis and thus it is one of the primary targets for antiangiogenic therapy. The long-term effects of VEGF include induction of proliferation and migration of endothelial cells, tube formation and maintenance of the immature capillaries. The early effects of VEGF include vasodilation and increased permeability. We hypothesize that the early responses to VEGF can serve to develop a quantitative measure of the activity of VEGF, and therefore may be applicable for monitoring the efficacy of systemic suppression of VEGF signaling during antiangiogenic therapy. For that end we tested the ability of MRI and fluorescence microscopy to detect the early response to intradermal VEGF165 in nude mice. VEGF-induced local vasodilation and increased permeability was detected by intravenous administration of macromolecular biotin-BSA-GdDTPA(23) 30 min after intradermal administration of VEGF. Contrast leak showed saturation kinetics. Delayed contrast administration (90 min after intradermal administration of VEGF) resulted in low contrast leak and demonstrated that the saturation kinetics is not due to contrast equilibration between plasma and the interstitial space, but rather is due to suppression of vascular permeability. Permeability was restored by a second bolus of VEGF, showing that the saturation kinetics is primarily due to inactivation of the growth factor. Confocal microscopy of fluorescent BSA-FITC confirmed the permeability changes monitored by MRI. Moreover, confocal microscopy showed efficient lymphatic uptake of the extravasated contrast material specifically in regions of VEGF induced hyper-permeability.     

The SARS-CoV-2 Lambda variant and its neutralisation efficiency following vaccination with Comirnaty,Israel, April to June 2021

The SARS-CoV-2 Lambda (Pango lineage designation C.37) variant of interest, initially identified in Peru, has spread to additional countries. First detected in Israel in April 2021 following importations from Argentina and several European countries, the Lambda variant infected 18 individuals belonging to two main transmission chains without further spread. Micro-neutralisation assays following Comirnaty (BNT162b2 mRNA, BioNTech-Pfizer) vaccination demonstrated a significant 1.6-fold reduction in neutralising titres compared with the wild type virus, suggesting increased susceptibility of vaccinated individuals to infection.     

Gaps in injury statistics: multiple injury profiles reveal them and provide a comprehensive account.

OBJECTIVE: To demonstrate the benefit of using multiple injury profiles (MIP) as an alternative to "primary diagnosis," for the presentation and analysis of multiple injuries in populations. METHODS: Retrospective analysis of national trauma registry data in Israel between 1 January 1998 and 31 December 2002. Multiple diagnoses per patient were recorded. A primary diagnosis was selected for each patient and data were presented twice: first by selecting a primary diagnosis and then using multiple injury profiles. RESULTS: 23 909 transport casualties were included. Findings show that MIP enable the identification of all patients with a specific injury, even where secondary. The proportion of additional injuries recorded when using MIP ranged from 12% in head injuries to 270% for facial injuries.Based on the primary diagnosis patients with head, chest, and abdominal injuries had a 5-6% inpatient death rate each. Multiple injury profiles of the same population reveal that an isolated head injury has a 3% inpatient death rate, isolated chest and isolated abdomen have a 1% inpatient death rate, while combined head and chest casualties have a 21% inpatient death rate. CONCLUSIONS: Multiple injury profiles are a new approach that enables presenting an improved picture of injury in a population.