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Biomedical subjects

M Daniels

Publications and source records attributed to M Daniels.

137 records · Page 8Linked to original sources
PubMed1966

Oxygen as a primary species in radiolysis of water.

Recent results are summarized of gamma-radiolysis of dilute nitrate solutions at neutral (p)H in the presence of oxygen and hydrogen as radical scavengers. Complete analysis of the system leads to values of the primary yields showing a net deficit of oxidized products of approximately 0.4. Analysis of results already available for the oxygen yield shows that oxygen originated from the radiolysis of water with a g value of approximately 0.1 (g values are derived values for yields of primary species for 100 electron volts). This finding gives material balance and provides evidence of oxygen being a product of water radiolysis.

Nitrates↗
PubMedDate not supplied

Preparative electrofocusing for industrial applications.

This paper presents a case study of using a multicompartment isoelectric focusing apparatus to determine the isoelectric points and focus preparative quantities of brain derived neurotrophic factor (BDNF) and neurotrophic factor 3 (NT3). A separation of PEGylated from unPEGylated forms of granulocyte colony stimulating factor (G-CSF) is described as well. Both BDNF and NT3 have substantially higher pI values in this system than is predicted from sequenced based modeling. Although PEGylated forms of G-CSF can be separated from the unPEGylated forms, separation of protein with differing degrees of PEGylation was not achieved. The paper additionally demonstrates that this technique can be used simultaneously as an analytical and preparative tool, eliminating the need for analytical IEF gels.

Brain-Derived Neurotrophic Factor↗
PubMedDate not supplied

Fungal pathogens of oat roots and tomato leaves employ closely related enzymes to detoxify different host plant saponins.

Antifungal saponins are produced by many plants and have been implicated as preformed determinants of resistance to fungal attack. The importance of saponin detoxification in fungal pathogenesis has recently been demonstrated for the fungus Gaeumannomyces graminis var. avenae, which produces the enzyme avenacinase. Avenacinase detoxifies the triterpenoid oat root saponin avenacin A-1, and is essential for pathogenicity of G. graminis var.avenae to oats. Here we demonstrate an unexpected relatedness between avenacinase and the tomatinase enzyme produced by Septoria lycopersici (a tomato leaf-infecting fungus), which acts on the steroidal glycoalkaloid alpha-tomatine. The two enzymes share common physicochemical properties and are immunologically cross-reactive; however, there are critical differences in their substrate specificities which reflect the host preferences of the fungi from which the enzymes were purified. The DNA encoding tomatinase was isolated from a S. lycopersici cDNA library using avenacinase DNA as a probe. Comparison of the predicted amino acid sequences of avenacinase and tomatinase revealed that the enzymes are clearly similar.

Amino Acid Sequence↗
PubMedDate not supplied

MCA in patients with breast cancer: correlation with CEA and CA15-3.

MCA serum levels were determined in 27 healthy subjects, 136 with benign pathology (42 breast) and in 289 patients with cancer (247 active). The last group includes 223 patients with breast cancer (96 without metastases, 89 with metastases and 38 no-evidence of disease). CEA and CA15-3 serum levels were determined in all the patients with breast diseases. The mean levels of MCA were 4.7 + 2.4 U/ml in the control group, considering less than 11 U/ml as normal. MCA values were abnormal in 15.4% of patients with benign pathology, mainly in those with liver cirrhosis (8/20) and lung diseases (4/20). In the majority of these cases, the rise was only moderate, lower than 15 U/ml in 97.5% of patients. In malignant diseases, important increments were found in breast cancer (19.8% Mo, 77.5% M1) and ovarian cancer stages III-IV (44.4%). When we compared MCA serum levels with CA15-3 and CEA in breast pathology, a similar specificity was observed: 92.3%, 92.3% and 100% in cases with benign pathology and 92.1%, 94.7%, and 97.4% in NED patients, respectively. MCA and CA15-3 sensitivity was similar in breast cancer without metastases (19.8%) and lower for CEA (16.7%). In patients with breast cancer without metastases, we found a relation between positivity of these tumor markers and prognostic factors (tumor size, nodal involvement). The disease free interval in patients with locoregional breast cancer was shorter in cases with abnormal presurgical levels of some of the tumor markers, but only the difference from MCA was significant (p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, Neoplasm↗
PubMedDate not supplied

Physician's assistants in primary care practices: delegation of tasks and physician supervision.

Little information is available on factors influencing physicians (MDs) to delegate health care tasks to physician's assistants (PAs). Information about assignment of tasks to PAs was sought from 19 MDs engaged in practice in primary care settings in Iowa. These MDs employed 28 PAs. Tasks assigned to PAs appeared to be those that MDs judged to require little or no supervision. Tasks that could be performed efficiently by other non-MD personnel were not asigned to PAs. However, PAs were observed at the practice sites to perform tasks which the MDs had indicated could be appropriately assigned to PAs, as well as some tasks that could be performed by other non-MD personnel. The MDs provided health care to 126 (13.6 percent) of the 925 patients seen by PAs for whom the sequences of patient-provider contact were recorded. In these settings, the PAs functioned with a high degree of autonomy in providing health care. These findings have implications for educators and potential employers of PAs.

Attitude of Health Personnel↗
PubMedDate not supplied

Students' expectations of clinical teachers.

Clinical instructors play an essential role in the education of all health care students, including radiation therapy students. However, a review of the literature shows that no studies have examined radiation therapy students' expectations of their clinical instructors. To assess those expectations, a national survey was conducted of 282 radiation therapy students enrolled in 61 programs in 28 states. Survey results then were analyzed to generate a list of the students' expectations of clinical instructors and to look at possible significant relationships between the various groups surveyed. Survey results showed that the most common expectation among first-, second- and third-year radiation therapy students was that their clinical instructors "take time, both in explaining procedures and answering questions." Among fourth-year students, the most commonly cited expectation for clinical instructors was that they "model professionalism."

Adult↗