Aqueous ZrO2 and YSZ Colloidal Systems through Microwave Assisted Hydrothermal Synthesis

In this paper, the formation of ZrO₂ and yttria-stabilised-zirconia (YSZ) aqueous colloidal systems via microwave assisted hydrothermal synthesis is studied. Microwave synthesis allows a fast screening of the influence of different parameters such as time and temperature. The temperature varied from 140 °C up to 180 °C and the used reaction time varied from 5 min up to 1 h. The synthesised zirconia nanoparticles have a particle size of 50 nm confirmed by TEM. A ¹H NMR (nuclear magnetic resonance) study helped to understand the stabilization mechanism of the synthesised particles. By the addition of ytrrium ions into the zirconia colloidal solution, YSZ could be formed via an additional thermal treatment. Hereby, the samples are heated up to 400 °C for 1 h. YSZ colloidal solutions are synthesised by making use of complexing agents such as nitrilotriacetic acid, ethylenediaminetetraacetic acid and citric acid to control the hydrolysis and condensation of both ions to avoid non-stoichiometric phases. The ratio of Zr/Y in the particles is quantified by XRF. The amorphous structure of those particles necessitates an additional thermal treatment up to 600 °C during 1 h in order to obtain crystalline YSZ.     

Current comprehensive assessment and management of women at increased risk for breast cancer

The potential for reducing the risk of breast cancer through selective estrogen receptor modulators, aromatase inhibitors, and surgery has generated interest in the use of quantitative models of risk assessment. With the addition of ductal lavage cytology to traditional epidemiologic risk factors, a discovery of cellular atypia can result in refinement of assigned risk values, while simultaneously optimizing patient selection for selective estrogen receptor modulators utilization. In view of increasing complexity in this arena, a Risk Assessment Working Group was formed to outline management strategies for the patient at an elevated risk for the development of breast cancer. No longer a statistical exercise, quantitative risk assessment is part of basic breast care and comprehensive management includes a discussion of the following: ductal lavage for improved risk stratification, multiple options for risk reduction, and high risk surveillance strategies that might incorporate investigational imaging protocols.     

The development of interval breast malignancies in patients with BRCA mutations

BACKGROUND: At present, there is no consensus regarding how frequently BRCA mutation carriers should be screened for malignancies using breast imaging techniques. An interval malignancy is defined as a malignancy that becomes evident during the period between annual screening mammography scans; the finding of such a malignancy indicates that the malignancy either went undetected by the last breast imaging scan or developed during the interval since that last scan. METHODS: The authors retrospectively reviewed the medical charts of all BRCA mutation carriers who were followed by the genetic counselor at the Columbia-Presbyterian Comprehensive Breast Center (New York, NY) between September 1995 and September 2002. RESULTS: Thirteen BRCA mutation carriers elected to undergo close surveillance and thus were followed at our institution. Three of these 13 patients (23%) did not develop breast carcinoma, 4 (31%) developed breast carcinoma that was detected at the time of annual screening, and 6 (46%) developed palpable interval malignancies in less than 12 months. Among the six patients who developed interval malignancies, the mean time between the last screening mammogram and disease presentation was 5.1 months (range, 2-9 months); the average tumor size in this patient subgroup was 1.7 cm (range, 0.8-3 cm). Two of these six patients had ductal carcinoma in situ, whereas the remaining four had invasive breast carcinoma; three patients had positive lymph nodes at presentation. All six patients who developed interval disease exhibited dense breast tissue on the previous mammogram. Focused breast ultrasonography was able to identify the tumor mass in 3 of 4 patients (75%). CONCLUSIONS: Nearly half of all BRCA-positive women who chose to undergo close surveillance in the current study developed malignant disease less than a year after exhibiting normal findings on screening mammography. Half of these interval malignancies were positive for lymph node involvement. These results suggest that strong consideration should be given to screening BRCA-positive women at more frequent intervals and to using additional imaging techniques, such as breast ultrasonography and/or breast magnetic resonance imaging, as a part of this screening.     

Association of pesticide exposure with neurologic dysfunction and disease

Poisoning by acute high-level exposure to certain pesticides has well-known neurotoxic effects, but whether chronic exposure to moderate levels of pesticides is also neurotoxic is more controversial. Most studies of moderate pesticide exposure have found increased prevalence of neurologic symptoms and changes in neurobehavioral performance, reflecting cognitive and psychomotor dysfunction. There is less evidence that moderate exposure is related to deficits in sensory or motor function or peripheral nerve conduction, but fewer studies have considered these outcomes. It is possible that the most sensitive manifestation of pesticide neurotoxicity is a general malaise lacking in specificity and related to mild cognitive dysfunction, similar to that described for Gulf War syndrome. Most studies have focused on organophosphate insecticides, but some found neurotoxic effects from other pesticides, including fungicides, fumigants, and organochlorine and carbamate insecticides. Pesticide exposure may also be associated with increased risk of Parkinson disease; several classes of pesticides, including insecticides, herbicides, and fungicides, have been implicated. Studies of other neurodegenerative diseases are limited and inconclusive. Future studies will need to improve assessment of pesticide exposure in individuals and consider the role of genetic susceptibility. More studies of pesticides other than organophosphates are needed. Major unresolved issues include the relative importance of acute and chronic exposure, the effect of moderate exposure in the absence of poisoning, and the relationship of pesticide-related neurotoxicity to neurodegenerative disease.     

Sulfotransferase 1A1 (SULT1A1) polymorphism,PAH-DNA adduct levels in breast tissue and breast cancer risk in a case-control study

Gene–environment interactions are hypothesized to be major contributors to susceptibility to environmental carcinogens and interindividual variability in cancer risk. We present findings on associations between genetic susceptibility due to inherited polymorphisms of the Phase II detoxification enzyme sulfotransferase 1A1 (SULT1A1), breast cancer risk, and polycyclic aromatic hydrocarbon (PAH)-DNA adducts. A hospital based case-control study was conducted at the New York-Presbyterian Medical Center (NYPMC). The study utilized two control groups: one comprised of women with benign breast disease (BBD) and the other comprised of women visiting NYPMC for routine gynecologic checkups (healthy controls). Blood samples were collected from cases and controls; and breast tissue from pathology blocks was collected from cases (tumor and non-tumor tissue) and BBD controls (benign tissue). PAH-DNA adduct levels were measured by immunohistochemistry in breast tissue samples, and the SULT1A1 (Arg/His) polymorphism at codon 213 was determined by PCR RFLP analyses using DNA from white blood cells. Increasing number of His alleles was modestly associated with breast cancer case-control status, when cases were compared to healthy controls (p for trend = 0.08), when cases were compared to BBD controls (p for trend = 0.08) and when cases were compared to both control groups combined (p for trend = 0.07). Contrary to our hypothesis PAH-DNA adduct levels in breast tissue were not associated with SULT1A1 genotype. Our findings are consistent with a prior report that the Arg/His polymorphism in SULT1A1 is associated with breast cancer risk.     

The moment arms of the muscles spanning the glenohumeral joint: a systematic review

The moment arm of a muscle represents its leverage or torque‐producing capacity, and is indicative of the role of the muscle in joint actuation. The objective of this study was to undertake a systematic review of the moment arms of the major muscles spanning the glenohumeral joint during abduction, flexion and axial rotation. Moment arm data for the deltoid, pectoralis major, latissimus dorsi, teres major, supraspinatus, infraspinatus, subscapularis and teres minor were reported when measured using the geometric and tendon excursion methods. The anterior and middle sub‐regions of the deltoid had the largest humeral elevator moment arm values of all muscles during coronal‐ and scapular‐plane abduction, as well as during flexion. The pectoralis major, latissimus dorsi and teres major had the largest depressor moment arms, with each of these muscles exhibiting prominent leverage in shoulder adduction, and the latissimus dorsi and teres major also in extension. The rotator cuff muscles had the largest axial rotation moment arms regardless of the axial position of the humerus. The supraspinatus had the most prominent elevator moment arms during early abduction in both the coronal and scapular planes as well as in flexion. This systematic review shows that the rotator cuff muscles function as humeral rotators and weak humeral depressors or elevators, while the three sub‐regions of the deltoid behave as substantial humeral elevators throughout the range of humeral motion. The pectoralis major, latissimus dorsi and teres major are significant shoulder depressors, particularly during abduction. This study provides muscle moment arm data on functionally relevant shoulder movements that are involved in tasks of daily living, including lifting and pushing. The results may be useful in quantifying shoulder muscle function during specific planes of movement, in designing and validating computational models of the shoulder, and in planning surgical procedures such as tendon transfer surgery.