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Biomedical subjects

J C James

Publications and source records attributed to J C James.

16 recordsLinked to original sources
PubMed1990

A sample computer system for physiological data acquisition and analysis.

This report outlines a sample configuration of a system which records, stores and analyses, graphically and statistically, neurophysiological and cardiovascular recordings during an experiment. The system is composed of sensitive physiological amplifiers, an analog to digital signal conversion board, scientific software, a 80286-based computer with 640 Kb of RAM, and a laser printer. Each component of the system is described along with the specific task(s) it performs.

Analog-Digital Conversion↗
PubMed1989

Wrongful life and wrongful birth. Implications for diagnostic sonography.

We trust that this communication will further the understanding of the concepts involved in wrongful life and wrongful birth and will assist the conduct of medical practice in such a way to minimize risks to patients and ultrasound physicians with regard to their liability. When these physicians are involved in wrongful life cases, we believe that the concepts presented will assist them in understanding the legal and societal environment in which they find themselves. We hope also that this communication may assist the defense attorney to more effectively prepare a response to the plaintiff's legal theory. Knowledge should provide understanding, if not relief.

Expert Testimony↗
PubMed1989

The concepts of wrongful birth and wrongful life and their relation to medical imaging.

Although often used interchangeably, "wrongful birth" and "wrongful life" are distinct legal concepts. Wrongful birth involves the physician's duty to impart to expectant parents information about potential fetal defects. Wrongful life suits reflect the child's right to recovery for life-long suffering as a result of the physician's inadequate pre- or peri-natal care. Modern medical imaging techniques can play a major role in the diagnosis of interuterine malformations; this article explores the legal duties which may be imposed upon physicians who interpret such tests.

Child Advocacy↗
PubMed1988

LL-F28249 antibiotic complex: a new family of antiparasitic macrocyclic lactones. Isolation, characterization and structures of LL-F28249 alpha, beta, gamma, lambda.

A new family of antiparasitic macrolides has been isolated from Streptomyces cyaneogriseus sp. noncyanogenus. The compounds, designated LL-F28249 alpha, beta, gamma and lambda, possess potent antiparasitic activity. The isolation, purification and structure determination by spectroscopic methods are presented.

Anti-Bacterial Agents↗
PubMed1986

Chemistry of maduramicin. II. Decarboxylation, abnormal ketalization and dehydration.

The behavior of the free acid and ammonium salt of maduramicin towards heat and alcohols is examined. In refluxing lower alcohols the free acid material is decarboxylated. In addition a bisketal decarboxylated compound as well as an A-ring monoketal decarboxylated derivative are formed. Heating the ammonium salt of the ionophores in suspension in water, or dissolved in inert solvents such as heptane or xylene can cause decarboxylation as well as concomitant dehydration of the F-ring. Reaction of dansyl chloride with the free acid of maduramicin can cause dehydration of the B-ring under very mild conditions.

Chemical Phenomena↗
PubMed1986

Chemistry of maduramicin. I. Salt formation and normal ketalization.

The formation of monovalent and divalent salt complexes of maduramicin is described and the 13C NMR chemical shift assignments of these materials are tabulated and discussed. In the spectrum of the thallium salt, 20 of the 47 signals are split due to the thallium-carbon coupling. Similarly the preparation of both the free acid and the sodium salt complexes of the normal methyl and ethyl ketal derivatives of maduramicin are outlined. Their 13C NMR spectra are fully assigned together with discussion of displacements observed due to this derivatization.

Carbon Isotopes↗
PubMed1985

Biosynthesis of chrysomycins A and B. Origin of the chromophore.

The biosynthetic origin of the carbon atoms in the chromophores of chrysomycins A and B was investigated in feeding experiments using 13C labeled acetates and propionate. A biosynthetic scheme is proposed involving the condensation and rearrangement of a decaketide intermediate which contains either propionate (chrysomycin A) or acetate (chrysomycin B) as the chain initiator.

Acetates↗
PubMed1984

New antitumor antibiotic, LL-C10037 alpha. Fermentation, isolation and structure determination.

A new antitumor antibiotic, LL-C10037 alpha was isolated from the fermentation filtrate of a Streptomyces by adsorption, partition and reverse phase column chromatography. Its chemical structure was determined by 1H NMR, 13C NMR, UV, IR and mass spectral data. LL-C10037 alpha is a gamma-aminoepoxysemiquinone and is related to the epoxyguinone class of antibiotics.

Antibiotics, Antineoplastic↗
PubMed1984

Biosynthesis of the antibiotic maduramicin. Origin of the carbon and oxygen atoms as well as the 13C NMR assignments.

The biosynthesis of maduramicin alpha and beta in a culture of Actinomadura yumaensis has been studied using 13C, 14C and 18O labeled precursors. The alpha component of this recently discovered polyether antibiotic, containing forty-seven carbon atoms in a seven-ring system, is derived from eight acetate, seven propionate and four methionine molecules. The beta component which is missing one methoxy group incorporates three methionine methyl groups. The carbohydrate moiety was enriched by methionine, but not significantly by acetate or propionate. Studies of the incorporation of 13C labeled precursors permit the 13C NMR assignment of maduramicin. The origin of oxygen atoms of maduramicin has been examined by feeding [1-13C, 18O2]acetate and [1-13C, 18O2]propionate separately in the fermentation culture and the resulting doubly labeled maduramicin samples were analyzed by the isotopic shifts in the 13C NMR spectra. These results are consistent with the initial formation of a triene, which is converted to maduramicin by cyclization of the triepoxide.

Actinomycetales↗
PubMed1973

Support of new principal investigators by NIH: 1966 to 1972.

In summary, Our findings indicate that the research project grant programs of NIH have consistently provided opportunities for newly trained scienitists to receive support for biomedical research projects that they have initiated themselves. The system encourages progress in the biomedical sciences through the continuous influx of creative individuals who can explore their own research ideas, ideas that also correspond to the health research needs of the nation as reflected by the categorical missions of the institutes. Despite the decline (approximately 20 percent) in the total number of active research projects over the past 7 years. the proportion of new PI's among all recipients of new awards remained fairly constant from year to year. From 1966 to 1972, an average of 57 percent of all new research project awards were received by PI's entering the system for the first time, while an average of approximately 10 percent of all the PI's on research projects each year were new PI's being supported by NIH for the first time.

Educational Status↗