SRP workshop on 'communication of radiation risk in the modern world'.

Communicating radiation risk is an important part of radiation protection. However, achieving effective risk communication is challenging given the negative public perception of radiation and conflicting views presented by both the media and social media. Noting the importance of building capacity amongst radiation protection professionals to communicate radiation risk effectively, the Society for Radiological Protection (SRP) ran a half-day workshop at its Annual Conference on the 22nd May 2019 in Scarborough Spa, UK. A number of key factors were identified that should be considered when communicating with the public, post a nuclear or radiological incident, communicating with government and local authorities, and communicating with the public as part of public outreach. The following memorandum provides a summary of the points presented and discussed. It also outlines proposed future activities of the SRP, focused on further developing the communications aspect of radiation professionals' practice.

Tabletop soft-x-ray Fourier transform holography with 50 nm resolution.

We present what we believe to be the first implementation of Fourier transform (FT) holography using a tabletop coherent x-ray source. By applying curvature correction to compensate for the large angles inherent in high-NA coherent imaging, we achieve image resolution of 89 nm using high-harmonic beams at a wavelength of 29 nm. Moreover, by combining holography with iterative phase retrieval, we improve the image resolution to <53 nm. We also demonstrate that FT holography can be used effectively with short exposure times of 30 s. This technique will enable biological and materials microscopy with simultaneously high spatial and temporal resolution on a tabletop soft-x-ray source.

Alterations in serotonin transporter expression in brain regions of rats exposed neonatally to chlorpyrifos.

Chlorpyrifos (CPF), one of the most widely-used organophosphate pesticides, is a suspected neuroteratogen. We administered CPF to neonatal rats on postnatal days (PN) 1-4 (1 mg/kg) or PN11-14 (5 mg/kg), treatments devoid of overt toxicity. At the end of the treatment period (PN5 and 15, respectively) and 5-7 days later, we then examined the effects on paroxetine (PXT) binding to the presynaptic 5HT high-affinity transporter, a marker for serotonin (5HT) projections. In males, we found a persistent decrease in PXT binding across the two different treatment regimens, with deficits apparent in a brain region containing 5HT terminal fields (forebrain) as well as in a region containing 5HT cell bodies (brainstem). In contrast, females given the early treatment regimen (PN1-4) showed deficits in the brainstem but transient elevations in the forebrain; the later treatment regimen (PN11-14) had no significant effect on PXT binding in females. These data are consistent with earlier work showing brainstem cell injury resulting from neonatal CPF exposure, and indicate specific damage to 5HT neurons, with a consequent loss of transporter expression in both terminal fields and perikarya. In females, the damage may be temporarily offset by initial trophic effects in the terminal region, consequent to the cholinergic stimulation evoked by cholinesterase inhibition via the active metabolite, CPF oxon. The gender-selective effects on 5HT systems are likely to contribute to similar gender dimorphism in behavioral performance. Because the CPF effects involve 5HT, a neurotransmitter intimately involved in the control of mood, we suggest the need to evaluate behaviors that typify animal models of depression.

Late follow-up after thoracoscopic ductal ligation.

Interventional catheterization and minimally invasive surgical techniques offer the real possibility of a reduction in cost and morbidity when compared with the traditional surgical approach to patent ductus arteriosus. Video-assisted thoracoscopic surgery may prove to be a superior technique because of its application to a wider range of patients needing ductal closure, a lower incidence of residual shunting, no evidence for recurrent shunting, and the absence of intravascular foreign bodies.

Enzymatic incorporation of 2'-thio-CTP into the HDV ribozyme.

We have synthesized the analogue 2'-deoxy-2'-thio-CTP (CTP-SH) and tested its ability to support RNA transcription in place of CTP. The modified nucleotide in a transcription reaction and in the absence of CTP generated the appropriately sized fragment when a mutant T7 polymerase (Y639F) was used. Wild-type polymerase was unable to generate RNA under the same conditions. Transcription was optimal around pH 7.5 and was dependent upon CTP-SH concentration. Transcripts containing the analogue were efficiently isolated using a thiol-activated sepharose column. Insertion of CTP-SH into the HDV ribozyme, replacing all cytidine residues with 2'-thiocytidine, appears to inhibit self-cleaving activity, even in the presence of manganese. The ability to introduce the CTP-SH analogue enzymatically into RNA opens the way for new structure-function studies where the 2'-hydroxyl can be efficiently replaced by a thiol group.

Sodium ipodate (oragrafin) in the preoperative preparation of Graves' hyperthyroidism.

Fourteen Graves' hyperthyroid patients who had been prepared for surgery with sodium ipodate (SI) 500 mg orally twice daily for 3 days were retrospectively studied. SI was administered in combination with propylthiouracil (10 cases) and beta blockers (all cases), which had been previously initiated. Free serum thyroxine (T4) and total triiodothyronine (T3) concentrations were measured before and after SI therapy on the morning of surgery. SI treatment significantly reduced total T3 concentration from 445.9 to 193.4 ng/dL (P < 0.0001) and free T4 concentration from 3.874 to 2.800 ng/dL (P = 0.0003). Preoperatively, only one patient had persistent tachycardia, and intraoperatively this same patient required beta blockers. Blood loss was unremarkable or reduced (average blood loss, 121 mL). On clinical examination glands were firm with normal or somewhat decreased vascularity. On histologic study all glands demonstrated changes consistent with treated Graves' disease. Preoperative treatment with SI appears to be a safe and efficacious method of preparing hyperthyroid patients for surgery.

Growth of the right heart after balloon valvuloplasty for critical pulmonary stenosis in the newborn.

Eight newborns with critical pulmonary stenosis and intact ventricular septum underwent successful percutaneous balloon dilation. Follow-up using echocardiography showed sustained relief of the obstruction across the pulmonary valve and excellent growth of the right heart structures.

Nursing and self-care theory applied to utilization review: concepts and cases.

The following article demonstrates how Dorothea Orem's Self-Care Theory of Nursing serves as a theoretical framework for the hospital-based utilization review process. Orem's theory is a popular and practical one which dovetails beautifully with the goals of any department of utilization management.

Cellular Vmax reflects both membrane properties and the load presented by adjoining cells.

This study was designed to test the hypothesis that the electrical load seen at a microelectrode impalement site is sensitive to the direction of propagation of the approaching wavefront as a reflection of an altered spatial relationship between the impalement site and the surrounding microscopic electrical boundaries located up- and downstream. These boundaries correspond to the different sizes and shapes of the impaled and surrounding cells as well as to the distribution of the associated electrical connections between the cells. The effects of changes in these geometric relationships on maximum rate of rise of transmembrane potential (Vmax) were investigated in canine ventricular muscle by measuring Vmax in different cells while the direction of propagation was changed from along the longitudinal axis to the transverse axis of the fibers or the direction of conduction was reversed along either of these axes. Comparison of the Vmax values for longitudinal propagation (LP) and transverse propagation (TP), each in one direction, showed that TP Vmax was significantly greater than LP Vmax (P < 0.001). However, the values of Vmax were different from cell to cell during LP (93-139 V/s) and TP (110-181 V/s). The absolute values of LP Vmax and TP Vmax at the same site varied independently of each other, e.g., some of the lowest LP Vmax values occurred at the same site as the highest TP Vmax values. Furthermore, at the same site, Vmax changed considerably when propagation was maintained along the longitudinal axis but the direction of conduction was reversed. Similar prominent changes in Vmax occurred when the direction was reversed along the transverse axis.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of temperature and infection with Eimeria ochrogasteri on digestive organs of the prairie vole, Microtus ochrogaster.

Prairie voles, Microtus ochrogaster, were infected with Eimeria ochrogasteri and exposed to 2 environmental temperatures, 5 and 22 C. Dry weights of the small and large intestines increased by 33% and 19%, respectively, in infected animals. Infected animals also exhibited a 14% decrease in cecal length compared to uninfected animals. The interaction between temperature and infection affected the length of the small intestine. Infected animals maintained at 5 C had longer small intestines than both infected animals housed at 22 C, and uninfected animals at 22 or 5 C. Furthermore, the dry weight of the small intestine was affected by a 3-way interaction (infection, temperature, and sex). Temperature affected stomach and liver dry weights, as well as lengths of the small intestine and cecum. Stomach and liver dry weights, as well as small intestine lengths, were greater in those animals held at 5 C, whereas cecum lengths decreased. Prepatency, patency, and total oocyst production were not affected by temperature; however, infected animals held at 5 C exhibited diarrhea during the patent period.

Aortic atresia with visceral situs inversus with mirror-image dextrocardia.

A newborn infant with situs inversus totalis (visceral situs inversus with mirror-image dextrocardia) with aortic atresia is presented. No reports of this anatomical variant have previously been reported in the literature. A brief discussion of the various types of congenital heart defects and their incidence in association with situs inversus totalis is presented.

Fine-needle aspiration biopsy of cold thyroid nodules.

This study analyzes the results of fine-needle aspiration biopsy (FNAB) of hypofunctioning thyroid nodules performed by one physician. There were 68 patients (age range, 20 to 73 years) with 83 aspirations; 30 were interpreted as positive for neoplasm (adenoma or carcinoma), 43 were negative, and ten (12%) were technically unsatisfactory. Thyroidectomy was performed on 25 patients who had positive aspirates. Subsequent morphologic study showed that 13 patients had carcinomas, ten had adenomas, and two had adenomatoid nodules (false-positive rate of FNAB for neoplasms was 8%). One of three thyroidectomy patients with negative preoperative aspirates had a carcinoma and two had adenomas (estimated minimal false-negative rate of FNAB was 9%). Nineteen patients who underwent thyroidectomies had dynamic radioisotopic thyroid angiography. There was no correlation between the pattern of vascularity and the type of neoplasm. Ultrasound (US) study was performed on 17 patients. Both adenoma and carcinoma can be solid or partially cystic. Although approximately 33% of the nodules initially diagnosed by FNAB as follicular or papillary neoplasms had different interpretations on subsequent examination of thyroidectomy specimens, 93% of the patients selected to be operated on had either adenoma or carcinoma. Thus, in this series, FNAB of cold thyroid nodules gave more useful diagnostic information than nodule size, dynamic radioisotopic scan, or US studies.

Carbohydrate reserves and infectivity in Trichinella spiralis isolated from carrion.

Trichinous mice were killed and their carcasses maintained at room temperature or subzero temperatures for varying lengths of time. Some worm parameters were measured after direct isolation from carcasses while others were measured following passage through a second round of hosts. Glycogen and trehalose levels in infective 1st-stage larvae (L1) isolated directly from carcasses maintained at room temperature were significantly less than controls (day 0) after day 4 post-kill (p.k.). By day 21 p.k. among L1 isolated directly from mouse carcasses those observed coiled or moving had decreased by around 20% compared to day 0 p.k. The percentage of L1 isolated from carcasses on several days p.k., used to infect mice and recovered as pre-adult worms declined significantly after they had remained in carcasses for 14 days. Only 2.6% of muscle larvae isolated from carcasses on day 21 p.k. and used to infect mice were recoverable as pre-adults. Pre-adult worms raised in mice infected with larvae from day 7 carcasses had about 50% less glycogen than worms raised in mice infected with larvae isolated from fresh carcasses (day 0 p.k.). The fecundity in vitro of adult worms isolated from mice on day 7 following infection with infective L1 larvae maintained in carcasses held at room temperature for 0-16 days declined only when adult worms developed from larvae recovered from carcasses at 3 days following host death. Following 24 h at temperatures below freezing, infectivity of L1 larvae isolated from frozen carcasses was reduced by 97%. Carbohydrate levels remained high in larvae from carcasses frozen for up to 4 days.

Trichinella spiralis: behavior, structure, and biochemistry of larvae following exposure to components of the host enteric environment.

Four layers are present on the surface of infective larvae of Trichinella spiralis isolated from host muscle in pepsin-HCl. Trypsin treatment of pepsin-HCl isolated worms caused partial degradation and removal of large patches of the two outer surface layers. Following exposure to bile, only traces of the outer layers remained on the worms surface. These changes in the worm surface were accompanied by a shift from Type I behavior, typical of pepsin-HCl isolated larvae, to Type II behavior, (snakelike) following exposure to either trypsin or bile. Worm behavior was also temperature dependent. Type I behavior was typical of worms maintained at room temperature regardless of treatment, while Type II behavior displayed by worms held at 37 C was treatment dependent. The absorption of in vitro glucose or beta-methyl-D-glucoside was lowest in pepsin-HCl isolated first stage infective larvae, significantly higher in trypsin treated worms and greatest in worms following exposure to bile. Sugar uptake by worms isolated from the host small intestine after 1 hr of enteral infection was similar to that seen in worms isolated from host muscle in pepsin-HCl. Sugar uptake in vitro in worms 2 hr following enteral infection was similar to worms following exposure to bile. The highest levels of sugar absorption in vitro occurred in worms which had resided in the small intestine for 3 hr. The lowest rates of incorporation of label into worm tissues was seen in 1 hr enteral and pepsin-HCl isolated worms. Infective larvae treated with trypsin or bile incorporated significantly greater amounts of label than the two former groups. The highest levels of incorporation of label into worm tissues was seen in 3 hr enteral worms. These findings support the view that trypsin, bile, and temperature serve as environmental cues which lead to alteration of the parasite's behavioral and nutritional status.