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B J Parson

Publications and source records attributed to B J Parson.

6 recordsLinked to original sources
PubMed2003

Antioxidative properties of Martynoside: pulse radiolysis and laser photolysis study.

Free radical reactions of Martynoside (MAR), a phenylpropanoid glycoside, with a variety of oxidants were studied in the aqueous solution by laser photolysis and pulse radiolysis techniques. The pKa value of MAR in aqueous solution was measured from the pH dependent changes of the UV absorption at 384 nm with value of pKa = 9.2. The phenoxyl radical of MAR which exhibits maximum absorption at 360 nm was generated by one-electron transfer to N3* or Br2*-. Other important properties of phenoxyl radical such as extinction coefficient, formation and decay rate constants were also determined. The reaction rate constant of O2*- with MAR, k = 8.5 x 10(4) dm3 x mol(-1) x s(-1), was measured by the method of competition kinetics. By measuring time-resolved luminescence emission at 1270 nm, the quenching rate constant of singlet oxygen by MAR was obtained to be 3.3 x 10(6) dm3 x mol(-1) x s(-1). Reduction potential of the MAR couple (MAR*/MAR), determined using rutin as reference compound, gave a value E = 0.66 V vs. NHE. The antioxidative properties of MAR were compared with those of some well-known antioxidants.

Animals↗
PubMed1980

Coagulation problems in patients with cancer.

The cases of 43 cancer patients and nine patients without cancer were reviewed to assess the coagulation mechanism in patients with cancer. Of the 43 patients with cancer, at least one factor known to be associated with coagulation disturbances was present in 26. Hematologic or coagulation studies disclosed one or more abnormalities in 34 of the patients. A subgroup of 17 patients had no clinical or laboratory evidence of ongoing variables that should interfere with coagulation or hemostasis. Of these, 11, or 65%, had one or more abnormal results from coagulation studies. Of the nine members of the control group (patients without cancer), no patient had a positive history for a clinical coagulation disorder except for one incidence of thrombophlebitis in the year preceding the study. During the study, at least one coagulation abnormality was disclosed by hematologic testing. The results support the concept that coagulation problems in cancer patients are attributable to debilitation, multiple organ involvement, and coagulation-interfering variables rather than to a primary effect of the malignant tumor.

Adolescent↗
PubMed1976

Pseudomonas ulceration of the cornea following major total body burn: a clinical study.

If periorbital or facial areas are involved in burn injury, the eyes must be given prophylactic care. The importance of these cases is not to point out the danger of corneal injury as a direct result of thermal trauma; rather, it is to emphasize the seriousness of corneal abrasions and the danger of subsequent Pseudomonas infection during convalescence of the postburn patient. Once the corneal epithelium is damaged, ulceration rapidly occurs and when infected with Pseudomonas aeruginosa presents one of the most difficult ophthalmologic situations. The convalescent burn patient is in jeopardy of corneal abrasion during general anesthesia for grafting or debridement. Neither of the patients who underwent anesthesia was noted to have corneal abrasion. Nor did either ectropion or lid contracture develop in the three patients described herein. Lid contracture may lead to corneal exposure and should be corrected by expeditious lid tarsorrhaphy. Once ulceration has occurred, as with these patients, corneal transplantation may be indicated.

Adult↗