Calorimetric study of blends of low density polyethylene (LDPE) and linear low density polyethylene (LLDPE) temperature rising elution fractionation (TREF) fractions

Preparative temperature rising elution fractionation (TREF) on commercial linear low density polyethylene (LLDPE) and low density polyethylene (LDPE) samples has been performed. The resulting fractions exhibited a bimodal and a unimodal distribution, respectively. Two LLDPE fractions of low (5 CH₃/1000 C) and high (21 CH₃/1000 C) short-chain branching content were solution-mixed with the LDPE central fraction (16 CH₃/1000 C). Indirect evidence based on differential scanning calorimetry results suggest that the fractions with similar branch contents are more miscible than those with dissimilar ones.     

Assessing postoperative discomfort after third molar surgery: a prospective study.

PURPOSE: The purpose of this study was to identify the risk factors for severe discomfort after mandibular third molar surgery and to assess the validity of the Postoperative Symptom Severity (PoSSe) scale. PATIENTS AND METHODS: In a 2-year prospective study, a total of 255 unilateral impacted mandibular third molar teeth were surgically removed under local anesthesia by 3 surgeons. Standardized surgical and analgesic protocols were followed. At the review appointment, 1 week after surgery, all patients returned a completed follow-up questionnaire (PoSSe scale) and were evaluated clinically for postoperative pain (number of painkillers taken) and trismus (differences in mouth opening). Sixteen predictive variables were evaluated using stepwise logistic regression analysis to identify the risk factors associated with severe discomfort. RESULTS: Severe postoperative discomfort was predicted by these independent variables: gender, tobacco use, ramus relationship/space available, and antibiotic prophylaxis. Oral contraceptive use and operation time were not identified as risk factors. The patients' perceptions of the severity of symptoms (PoSSe scale score) was strongly correlated with clinical assessment of trismus (r = 0.54) and pain (r = 0.42). CONCLUSION: The PoSSe scale resulted in a valid and responsive measure of the severity of symptoms after surgical extraction of lower third molars and reflected the clinical severity of the postoperative discomfort. From a patient's perspective, operative factors had little bearing on the quality of life after removal of mandibular third molars.     

Cervical Cancer with Paraaortic Metastases: Significance of Residual Paraaortic Disease after Surgical Staging

Cervical carcinoma frequently metastasizes to the paraaortic region, necessitating extended field radiotherapy to effect a cure. As imaging modalities are unreliable in identifying all cases of paraaortic nodal metastases (PAN), surgical staging is often utilized prior to radiotherapy. This study was aimed at identifying factors predictive of survival in women with cervical carcinoma and paraaortic metastases. In particular, survival based on extent of paraaortic disease was examined. The study group consisted of 43 women (stages IB–IVB) identified between 1982 and 1993 who were treated with extended field radiation for cervical carcinoma with histologically confirmed paraaortic metastases. The estimated 5-year survival for the study population was 24% with a median survival of 18 months. Pelvic tumor size had a significant impact on survival with the median survival being 34 months if the primary lesion was <6 cm compared to 14 months if ≥6 cm (P= 0.01). Eight of the 26 (31%) women without residual PAN disease after surgical staging remain alive and disease free (mean follow-up, 74 months). In contrast, only 1 of the 17 (6%) women with gross residual PAN is alive 71 months after treatment (P= 0.05). However, a comparison of Kaplan–Meier survival curves did not show a statistically significant advantage to the surgical excision of grossly involved PAN (P= 0.98). Although long-term survival among women with grossly involved, unresected paraaortic metastases is uncommon, further study is necessary to elucidate the role of surgical excision of bulky aortic disease in women with cervical cancer.     

Association of HLA-DQA1*03011-DQB1*0301 haplotype with the development of respiratory scleroma.

OBJECTIVE: Respiratory scleroma (RS) is a progressive, chronic, granulomatous disease caused by Klebsiella rhinoscleromatis. There is only one report of RS association with HLA-DQ3. In this study, molecular association of HLA class II and RS was determined. STUDY DESIGN AND SETTING: Nine RS patients and 163 healthy controls were compared. DQA1, DQB1, and DRB1 loci were typed. RESULTS: Statistical analysis demonstrated association between DQB1*0301 and susceptibility to RS (P(c) = 0.004). Haplotype analysis showed an association of DQA1*03011-DQB1*0301 (P = 1.21E-19) and DRB1*0407-DQA1*03011-DQB1*0301 (P = 0.0002). CONCLUSIONS: Results established that DQA1*03011-DQB1*0301 haplotype is a strong risk factor for development of RS.     

Transient hypoparathyroidism following thyroidectomy: a prospective study and multivariate analysis of 604 consecutive patients.

OBJECTIVE: The purpose of this study was to identify the risk factors for postoperative transient hypoparathyroidism in a group of patients undergoing thyroid surgery. STUDY DESIGN: A prospective study was conducted on 604 patients undergoing thyroid surgery. SUBJECTS AND METHODS: Gender, final diagnosis, extent of resection, biology of pathology, intrathoracic involvement, surgery for recurrent multinodular goiter, and presence and number of parathyroid glands in a surgical specimen were analyzed as risk factors for postoperative transient hypoparathyroidism. The chi-square test and a logistic regression analysis were applied. RESULTS: On logistic regression analysis, only the extent of surgery constituted an independent variable for transient hypoparathyroidism (P = 0.001). CONCLUSION: The extent of surgery to central and/or lateral neck lymph nodes is responsible for a high rate of transient hypoparathyroidism owing to a high probability of unplanned parathyroidectomy or parathyroid gland devascularization.     

Rest-injected thallium-201 redistribution and resting technetium-99m methoxyisobutylisonitrile uptake in coronary artery disease: relation to the severity of coronary artery stenosis

To compare rest-injected thallium-201 (Tl) redistribution and resting technetium-99m methoxyisobutylisonitrile (^99mTc-MIBI) myocardial uptake in chronic coronary artery disease (CAD), 15 patients with angiographically proven CAD and left ventricular (LV) dysfunction (ejection fraction 34%±9%) were studied. All patients underwent rest-redistribution Tl and resting ^99mTc-MIBI cardiac imaging. Gated ^99mTc-MIBI images were also acquired to assess regional LV wall motion (WM). Myocardial segments (n=225) were divided into three groups on the basis of the degree of coronary artery stenosis: group 1 (total occlusion, n=82), group 2 (50%–99% of stenosis, n=84) and group 3 (<50% of stenosis, n=59). WM was significantly worse in groups 1 and 2 compared to group 3 (P<0.001), but no difference was observed between groups 1 and 2. TI and ^99mTc-MIBI uptake were significantly lower in groups 1 and 2 compared to group 3 (P < 0.001), and in group 1 compared to group 2 (P<0.001). When TI and ^99mTc-MIBI uptake were directly compared, TI uptake was higher than ^99mTc-MIBI uptake in group 1 (P<0.001), while no significant difference was observed in groups 2 and 3. Thus, both rest-injected TI redistribution and resting ^99mTc-MIBI uptake reflected the severity of coronary artery stenosis in CAD. However, in myocardial segments with total coronary occlusion T1 uptake was significantly higher than ^99mTc-MIBI uptake. Our data suggest that rest-injected Tl redistribution cardiac imaging may identify, more accurately than resting ^99mTc-MIBI imaging, the presence of viable myocardium in chronic CAD, particularly when the coronary blood flow is severely impaired.