A liquid-scintillation-based primary standardization of Pb

A new radioactivity solution standard of ²¹⁰Pb has been developed and will be disseminated by the National Institute of Standards and Technology (NIST) as standard reference material (SRM) 4337. This new ²¹⁰Pb solution standard is contained in a 5 mL flame-sealed borosilicate glass ampoule, consists of (5.133±0.002) g of a nominal 1 mol L⁻¹ nitric acid solution, has a density of (1.028±0.002) g mL⁻¹ at 20 °C, has carrier ion concentrations of about 11 μg Pb²⁺ and 21 μg Bi³⁺ per gram of solution, and is certified to contain a massic activity (9.037±0.22) kBq g⁻¹ as of the reference time 1200 EST, 15 June 2006. All of the uncertainties cited above correspond to standard uncertainties multiplied by a coverage factor k=2. The standardization for the ²¹⁰Pb content of the solution was based on 4πβ liquid scintillation (LS) measurements using CIEMAT/NIST ³H-standard efficiency tracing (CNET). Confirmatory determinations were also performed by high-resolution HPGe γ-ray spectrometry, by 2π spectrometry with a Si surface barrier detector of separated ²¹⁰Po, and by 4πβ(LS)–γ(NaI) anticoincidence counting.     

A note on the half-life of 209Po.

The widely adopted value of (102+/-5)a for the (209)Po half-life, which is based on a single determination reported in 1956, appears to be in error by a large factor. Decay data from two separate primary standardizations of a (209)Po solution standard, conducted approximately 12 years apart, are inconsistent with the adopted value and its assigned uncertainty. An estimated half-life, larger than the adopted value by about 25%, is more consistent with the standardization data. A longer half-life is also supported by measurements on a recently standardized (210)Pb solution standard.     

Tirapazamine, Cisplatin, and Radiation versus Fluorouracil, Cisplatin, and Radiation in patients with locally advanced head and neck cancer: a randomized phase II trial of the Trans-Tasman Radiation Oncology Group (TROG 98.02).

PURPOSE: To select one of two chemoradiotherapy regimens for locally advanced squamous cell carcinoma (SCC) of the head and neck as the experimental arm for the next Trans-Tasman Radiation Oncology Group phase III trial. PATIENTS AND METHODS: One hundred twenty-two previously untreated patients with stage III/IV SCC of the head and neck were randomized to receive definitive radiotherapy (70 Gy in 7 weeks) concurrently with either cisplatin (75 mg/m(2)) plus tirapazamine (290 mg/m(2)/d) on day 2 of weeks 1, 4, and 7, and tirapazamine alone (160 mg/m(2)/d) on days 1, 3, and 5 of weeks 2 and 3 (TPZ/CIS), or cisplatin (50 mg/m(2)) on day 1 and infusional fluorouracil (360 mg/m(2)/d) on days 1 through 5 of weeks 6 and 7 (chemoboost). RESULTS: Three-year failure-free survival rates were 55% with TPZ/CIS (95% CI, 39% to 70%) and 44% with chemoboost (95% CI, 30% to 60%; log-rank P = .16). Three-year locoregional failure-free rates were 84% in the TPZ/CIS arm (95% CI, 71% to 92%) and 66% in the chemoboost arm (95% CI, 51% to 79%; P = .069). More febrile neutropenia and grade 3 or 4 late mucous membrane toxicity were observed with TPZ/CIS, while acute skin radiation reaction was more severe and prolonged with chemoboost. Compliance with protocol treatment was satisfactory on both arms. CONCLUSION: Both regimens are feasible and are associated with significant but acceptable toxicity profiles in the cooperative group setting. Based on the promising efficacy seen in this trial, TPZ/CIS is being evaluated in a large phase III trial.     

Peritoneal and intestinal tuberculosis: an ancestral disease that poses new challenges in the technological era. Case report and review of the literature

Tuberculosis is a public health problem. The most common presentation is pulmonary disease. The diagnosis of any extrapulmonary forms are quite difficult. Clinical manifestations of gastrointestinal tuberculosis are non-specific and compatible with pathologies such as inflammatory bowel disease, advanced ovarian cancer, deep mycosis, yersinia infection and amebomas. Abdominal form is located at 6th place of the extrapulmonary forms, after lymphatic, genitourinary, osteoarticular, miliary and meningeal infections. Eventually, 25 to 75% of patients with abdominal tuberculosis will require surgery. These procedures should be limitated with the purpose to preserve small bowel. Resection should be limitated for complicated cases. The surgical indications include: Intestinal occlusion (15-60%), perforation (1-15%), abscesses and fistulas (2-30%) and hemorrhage (2%). CONCLUSIONS: In most of the cases, the diagnosis of peritoneal or intestinal tuberculosis is made during a laparoscopy or laparotomy even during surgery performed by different purposes. Excessive manipulation of the intraabdominal organs may produced unexpected bowel lesions, increasing morbidity and mortality. Medical treatment is highly effective in the resolution of moderate complications such as bowel obstruction. Resectional procedures should be reserved for complications like perforation, bleeding or stenosis non-suitable for stricturoplasty.     

Elevation in serum thyroglobulin during prolonged Antarctic residence: effect of thyroxine supplement in the polar 3,5,3'-triiodothyronine syndrome

Extended Antarctic residence (AR) is associated with an increase in serum TSH, a decrease in free T(4), and an increase in T(3) production and clearance. It is not clear whether these adaptations reflect changes in clearance alone or whether intrinsic thyroidal synthetic activity also changes. Thyroglobulin (Tg) secretion is an independent marker of intrinsic thyroid activity whose kinetics are independent of those of T(3) and T(4). In this study we examined changes in Tg levels in healthy subjects before and during AR and their responses to thyroid supplementation to help determine whether alterations in thyroid activity, and not just kinetics of clearance, underlie the changes seen with the polar T(3) syndrome. In cohort 1, we compared measurements of TSH and Tg in 12 subjects before deployment and monthly for 11 months during AR. In cohort 2, we compared the same measurements in 12 subjects monthly for 11 months of AR. Subjects were randomized to receive either placebo or levothyroxine in cohort 1 for 7 months and in cohort 2 for 11 months. Tg increased over baseline during the first 4 months of AR by 17.0 +/- 4.6% and after 7 more months by 31.7 +/- 4.3% over baseline in the placebo group of both cohorts (P < 0.0002). When L-T(4) was taken, Tg returned to a value not different from baseline (4.5 +/- 3.9%). The percent changes from baseline in serum TSH and Tg during AR were highly correlated (P < 0.00003) in the placebo group for both cohorts. The rise in Tg with TSH and the reduction in Tg with L-T(4) provide evidence of target tissue response to TSH and further confirm the TSH rise as physiologically significant. The results also suggest that the adaptive changes in thyroid hormone economy with AR reflect TSH-dependent changes in thyroid synthetic activity, which may help explain a portion of the increases in T(3) production found with AR.     

Coordinated hospital-home care for kidney patients on hemodialysis from the perspective of nursing personnel

OBJECTIVE:

To examine, from the nursing perspective, the needs and challenges of coordinated hospital-home care for renal patients on hemodialysis.

METHODS:

A qualitative analysis was conducted with an ethnographic approach in a hemodialysis unit in San Luis Potosi, Mexico. Semistructured interviews were conducted with nine nurses, selected by purposeful sampling. Structured content analysis was used.

RESULTS:

Nurses recounted the needs and challenges involved in caring for renal patients. They also identified barriers that limit coordinated patient care in the hospital and the home, mainly the work overload at the hemodialysis unit and the lack of a systematic strategy for education and lifelong guidance to patients, their families and caregivers.

CONCLUSIONS:

This study shows the importance and necessity of establishing a strategy that goes beyond conventional guidance provided to caregivers of renal patients, integrating them into the multidisciplinary group of health professionals that provide care for these patients in the hospital to establish coordinated hospital-home care that increases therapeutic adherence, treatment substitution effectiveness and patient quality of life.     

Utilization of Prophylactic Antibiotics After Nasal Packing for Epistaxis

BackgroundThere have been few investigations examining the benefits, consequences, and patterns of use for prophylactic antibiotics for nasal packing in the emergency department setting. Given the frequency of epistaxis in the emergency department, it is an ideal setting to study the efficacy and utilization patterns of prophylactic antibiotics in nasal packing.ObjectiveOur aim was to assess both rates of utilization and evidence of benefit for prophylactic antibiotics in patients with nasal packing for epistaxis.MethodsA single-institution retrospective review of 275 cases of anterior nasal packing in an urban emergency department between September 2013 and April 2017 was performed. Chi-square statistical analysis was used to evaluate results.ResultsAmong 275 cases studied, there were no instances of toxic shock syndrome. Roughly 73% of patients with nonabsorbable packing received prophylactic antibiotics. Only one (1.1%) case of sinusitis was noted among the nonabsorbable packing with prophylaxis group, with no such complication in the nonprophylaxis group. In contrast, 95% of patients with absorbable nasal packing were not given prophylactic antibiotics. Analysis of all cases given prophylactic antibiotics vs. no prophylaxis, regardless of packing type, revealed no statistically significant difference in the development of acute sinusitis (1% vs. 0.56%; p = 0.6793).ConclusionsThere was no observed advantage or disadvantage to using prophylactic antibiotics in anterior nasal packing in the emergency department, regardless of whether patients received absorbable or nonabsorbable packing. However, patients who receive nonabsorbable nasal packing were more likely to receive antibiotic prophylaxis.     

COVID-19 in the Context of Inborn Errors of Immunity: a Case Series of 31 Patients from Mexico

Journal of Clinical Immunology - Patients with inborn errors of immunity (IEI) have a compromised or inappropriate immune response. Although they might be considered a high-risk group for severe...