tert-Butyl peresters as initiators in vinyl polymerizations. I.

Peresters dissociate thermally to alkoxy and acyloxy radicals. The acyloxy radical may dissociate further into an aryl radical and carbon dioxide. Alternatively they may break into these products in a single stage reaction. The decomposition of tert-butyl perbenzoate has been studied and it has been shown that the primary products of the dissociation of this ester are alkoxy and acyloxy radicals. The polymerization of styrene, using tert-butyl perbenzoate, tert-butyl percinnamate and tert-butyl percrotonate has been studied at 120 ± 1°C. It has been shown that the rate of polymerization is proportional to the square root of the initiator concentration and the 3/2 power of the monomer concentration.     

Suppressor T cells for delayed-type hypersensitivity to Japanese encephalitis virus.

The delayed-type hypersensitivity (DTH) to Japanese encephalitis virus (JEV) and the suppressor cells controlling it and the antibody-forming cells in inbred Swiss mice have been studied. JEV induces DTH, with a peak response at day 7 following infection which persists at low levels at least up to 119 days. Suppressor activity appeared on day 18. It was transferable by immune spleen cells. Treatment of spleen cells with anti-Thy-1.2 antisera and complement abrogated the suppressor activity. The homogenate of the spleen was equally effective in mediating suppression of DTH and the humoral response as measured by direct antibody plaque-forming cell (IgM-PFC) assay. The suppressor activity was antigen-specific both on DTH and T helper for antibody response as the immune responses against SRBC or Coxsackie B4 virus were not suppressed. The suppressor cells were sensitive to cyclophosphamide treatment when the drug was given 48 hr before their appearance. It is, therefore, concluded that in JEV infection of mice, antigen-specific suppressor T cells are generated, both for DTH and IgM antibody, which are cyclophosphamide-sensitive and mediate suppression through soluble product(s).     

Is patient age associated with risk of malignancy in a ≥4 cm cytologically benign thyroid nodule?

BackgroundCurrent data regarding the risk of malignancy in a large thyroid nodule with benign fine-needle aspiration biopsy(FNAB) is conflicting. We investigated the impact of patient age on the risk of malignancy in nodules≥4 cm with benign cytology.MethodsWe performed a single-institution retrospective review of patients who underwent surgery from 07/2008–08/2019 for a cytologically benign thyroid nodule ≥4 cm. The relationship between malignant histopathology and patient and ultrasound features was assessed with multivariable logistic regression.ResultsOf 474 nodules identified, 25(5.3%) were malignant on final pathology. In patients <55 years old, 21/273(7.7%) nodules were malignant, compared to 4/201(2.0%) in patients ≥55. Patient age ≥55 was independently associated with significantly lower risk of malignancy(OR:0.2,95%CI:0.1–0.7,p = 0.011). Increasing nodule size >4 cm and high-risk ultrasound features were not associated with risk of malignancy(OR:1.0,95%CI:0.7–1.4,p = 0.980, and OR:9.6,95%CI:0.9–107.8,p = 0.066, respectively).ConclusionsPatients <55 years old are 3.7-fold more likely to have a falsely benign FNA biopsy in a nodule≥4 cm.     

Association between age and disease specific mortality in medullary thyroid cancer

BackgroundThe aim of this study was to evaluate the association between age and disease specific mortality (DSM) among adults diagnosed with medullary thyroid cancer (MTC).MethodSurveillance, Epidemiology, and End Results (SEER-18) was used to analyze adult MTC patients stratified by age (18–64, 65–79, ≥80 years). Associations between patient demographics, tumor size, nodal status, metastatic disease, and extent of surgery on DSM was assessed with multivariable Cox regression.ResultsAmong 1457 patients with MTC, 1008 (69.2%) were younger adults, 371 (25.5%) older adults, and 78 (5.4%) were super-elderly. A significantly higher proportion of older adults and super-elderly had less than the recommended operation for MTC. On multivariable analysis, older adults and super-elderly were 2.9 and 6.7 times more likely to have an increased DSM (HR:2.91, 95% CI: 1.83–4.63; p < 0.001 and HR: 6.70, 95%CI: 3.69–12.20; p < 0.001). Extent of surgery or lymphadenectomy did not affect DSM.ConclusionsIncreased age is an independent predictor of DSM in patients with MTC.     

Characteristics and Motivation of Solid Organ Transplant Recipients Attending the Canadian Transplant Games

BackgroundThe Canadian Transplant games (“Games”) were created to increase awareness of organ donation and highlight the importance of staying active and healthy post-transplant. It is unclear what motivates solid organ transplant (SOT) recipients to participate and whether the games serve as an incentive for SOT recipients to increase their physical activity (PA) levels.Objectives1. To describe the characteristics of participants from past games and their motivation for attending and 2. to determine whether there was an interest in participating in goal-based, pre-games exercise training programs.MethodsA web-based questionnaire was sent to adult SOT recipients who were members of the Canadian Transplant Association. The survey included questions about why participants attended, their PA levels, and their interest in a pre-games training program.ResultsOf the 157 participants, more were male than female; the 35-54-year-old age group was the most common; and 62% of respondents received a liver or kidney transplant. The most common reasons for participating in the games were to showcase health post-transplant, promote awareness of organ donation, sports competition, and social reasons. Sixty-five percent of respondents reported that they would be interested in an exercise program to be more physically prepared for the competition.ConclusionPre-games training programs could be developed to motivate participation and help participants achieve higher training intensities and foster social interaction. Directing resources to individuals who do not attend the games and to those who are not physically active should be considered.     

The clinical radiological and histological correlation of orbital assessment in malignant lesions of the maxillo-ethmoid complex

Twelve patients undergoing surgery between May 1995 and March 1999 for malignant tumours of the paranasal sinuses abutting or invading the orbital walls were studied for the need to remove orbital contents. Alt patients were evaluated clinically, radiologically (CT Scan) and per-operatively to delineate the extent of orbital invasion. Combined regimen (Surgery + Radiotherapy) were used in all patients. A biopsy from periorbita was taken when eye was spared. It was found that per-operative evaluation of the orbit is equally specific in comparision to clinical and CT Scan combined and eye may be preserved in selected patients with involvement of orbital periosteum provided there is no frank soft tissue mass in the orbit.     

Role of lateral neck dissection in cancers of the larynx and hypopharynx with No neck

Radical neck dissection is a standard procedure carried out for the teatment of palpable nodes in the neck but if carried out electively in cases where there are no palpable nodes in the neck it is considered to be an overtreatment with its associated morbity. Lateral neck dissection was carried out on twenty patients who had T31 T4 lesion of the larynx and hypophar-vnx with NO neck. The dissection entails removal of Level II. III and IV nodes. Occult metastasis 80% and 85% respectively. The mean follow up was 13 monts. It appears from our study that elective lateral neck dissection is a promising and safe procedure and may be useful as an important prognostic tool in sampling the lymph nodes and predicting recurrences in the neck.     

Epidemiology of early neonatal mortality

During 1981-1991 at a rural teaching hospital (Kasturba Hospital) of Mahatma Gandhi Institute of Medical Sciences in Sevagram, Wardha, India, 454 of 13,939 newborns died during the early neonatal period for an early neonatal mortality rate (ENMR) of 33.7/1000 live births. The ENMR for boys was not significantly different from that for girls (36.1 vs. 28.6). Community medicine specialists analyzed data on these early neonatal deaths to examine distribution of early neonatal mortality, especially its relationship with prematurity, low birth weight, birth order, and by sex. They calculated average percent deaths (APD) per hour to examine the dynamics in early neonatal mortality. The mean age at death was lower among newborns of birth order greater than 2 than those of birth order less than 2 (23.47 vs. 26.85 hours; p 0.001). ENMR was higher for newborns of birth order greater than 2 than those of birth order less than 2 (41.74% vs. 27.35%; P 0.001). The mean age at death increased as gestation increased (10.34 for 28 weeks; 24.27 for 28-33 weeks, 31.53 for 33-37 weeks, and 34.43 for 37 weeks; p 0.001). ENMR decreased as gestation increased (850 for 28 weeks; 375 for 28-33 weeks, 147.02 for 33-37 weeks, and 8.77 for 37 weeks; p 0.001). The mean age at death increased as birth weight increased for newborns weighing less than 1500 gms through 2000-2500 gms (23.36-37.13 hours; p 0.001). It was lowest among those weighing more 3000 gms (11.55 gms). ENMR fell as birth weight increased (614.33 for 1500 gms, 116.19 for 1500-2000 gms, 19.38 for 2000-2500 gms, 10.99 for 2500-3000 gms, and 5.41 for 3000 gms; p 0.001). The APD/hour for the first hour of life was 3.74% for a relative risk of 12.9. It decreased steadily as the hours of life increased (3.08% for 1-6 hours, 1.19% for 6-24 hours, 0.67% for 24-72 hours, and 0.29% for 72-168 hours). Knowledge of time of likely death can help providers know where they need to focus their attention to prevent early neonatal deaths.