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Biomedical subjects

J D Anderson

Publications and source records attributed to J D Anderson.

At least 199 records · Page 11Linked to original sources
PubMed1971

Glucose metabolism of embryos and endosperms from deteriorating barley and wheat seeds.

Changes in glucose utilization into CO(2) and ethanol-insoluble material were followed in whole seeds, embryos, and endosperms of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) which had reached different levels of deterioration through accelerated aging treatments. Excised embryos from deteriorated wheat seeds had reduced respiration and glucose utilization into ethanol-insoluble material but not into CO(2). These treatments had no effect on respiration of excised endosperms, although they reduced utilization of glucose into ethanol-insoluble material and CO(2). Changes in metabolic activity of whole seeds in response to deterioration treatments are difficult to interpret because they represent the sum of the changes that take place in the embryos and endosperms. Changes in respiration and glucose utilization in these two tissues neither proceed at the same rate nor go in the same direction during deterioration.Incubation of excised embryos and endosperms in glucose-(14)C under N(2), as compared to air, affects the utilization but not the uptake of glucose. Embryos produce more (14)CO(2) and less labeled ethanol-insoluble material under N(2) as compared to air. The responses of endosperms to N(2) are of a much lower magnitude than those of embryos.

Journal Article↗
PubMed1970

Metabolic Changes in Partially Dormant Wheat Seeds during Storage.

Changes in germination, seedling growth, respiration, response to applied gibberellic acid, and glucose-U-(14)C utilization were investigated in partially dormant wheat (Triticum aestivum L., Pa 151 x 107) seeds which were stored under various conditions for periods up to 1 year. Only seeds stored at -20 C and 12.4% moisture maintained partial dormancy, which was overcome by germinating in 10(-3)m gibberellic acid. Germination and seedling growth of seeds stored at 25 C and 15.1% moisture declined within 12 weeks and the percentage of seeds infected with storage fungi increased. Gibberellic acid produced faster growing seedlings, particularly from those seeds with partial dormancy, but did not overcome growth reduction which was caused by deterioration. Seeds kept under laboratory conditions (B), 25 C and 12.1% moisture (C), and 25 C and 15.1% moisture (D) for 12 weeks utilized 35, 55, and 80% less glucose, respectively, than those stored at -20 C and 12.4% moisture (A). Seeds stored under B and C consistently had higher germination, growth, and respiratory rates than seeds from A and D. The respiratory rate declined as deterioration advanced under D. Respiratory quotients ranged from 1.0 for seeds stored under A to 1.6 for seeds stored under D.

Journal Article↗
PubMed1967

Biosynthesis of (-)-Kaurene in Cell-free Extracts of Immature Pea Seeds.

Mevalonate-(14)C was incorporated into (-)-kaurene-(14)C in cell-free extracts of immature pea (Pisum sativum L.) seeds. The identification of (14)C-product as (-)-kaurene was based on: A) comparison with authentic (-)-kaurene on thin-layer and gas-liquid chromatography; and B) oxidation of (14)C-product and (-)-kaurene with osmium tetroxide to form the common derivative kaurane-16,17-diol. The enzyme system is heat labile and is dependent upon ATP and Mg(2+) or Mn(2-), with Mn(2+) being a more effective activator than Mg(2+). The reaction rate was proportional to enzyme concentration in reaction mixtures containing 0.45 to 1.8 mg protein n/ml, and was linear with time through 120 minutes in standard reaction mixtures. Enzyme preparations from immature seeds of tall and dwarf peas appeared to synthesize (-)-kaurene at the same rate. Synthesis of (-)-kaurene was readily inhibited by Amo-1618. (2-Chloroethyl)-trimethylammonium chloride (CCC) also inhibited (-)-kaurene synthesis; however, approximately 1000-fold higher concentrations of CCC were required to evoke the same percentages of inhibition as Amo-1618.

Journal Article↗
PubMed1966

Inhibition of the growth of peas by tris-(2-diethylaminoethyl)-phosphate trihydrochloride.

The effects of Tris-(2-diethylaminoethyl)-phosphate trihydrochloride (SK&F 7997-A(3)) on the development of 4 varieties of Pisum sativum were investigated. The compound inhibited shoot elongation of all 4 varieties by as much as 50% or more when seeds were soaked in solutions of the inhibitor for 12 hours before planting. Seed treatment also affected flowering by causing an increase in the number of nodes to the first flower in the early varieties Little Marvel and Alaska. The number of nodes preceding the first flower in the late varieties Dwarf and Tall Telephone was not affected by high concentrations of SK&F 7997-A(3), but low concentrations appeared to cause a slight reduction in the number of nodes to flower.The inhibitor had little effect on growth when applied to established seedlings; some slight inhibition was noted when high doses were applied to the shoot tip.SK&F 7997-A(3) suppressed the growth response of dwarf and tall peas to exogenous GA(3). The compound did not inhibit biosynthesis of gibberellin by Fusarium moniliformc when present in shaken liquid cultures at concentrations as high as 10 mg/ml. The inhibitor suppressed the action of applied GA(3) on shoot elongation when the 2 chemicals were applied in 3 ways: 1) inhibitor on lowermost compound leaf and GA(3) on shoot tip; 2) GA(3) on lowermost leaf and inhibitor on shoot tip; and 3) soaking of seeds in the 2 compounds combined for 12 hours prior to planting. The third method of dual treatment yielded evidence that SK&F 7997-A(3) interacts noncompetitively with GA(3) in the regulation of shoot elongation.

Journal Article↗
PubMedDate not supplied

H2-receptor antagonists and hepatic drug disposition.

The effect of four H2-receptor antagonists (cimetidine, burimamide, oxmetidine, and ranitidine) on antipyrine elimination was studied in the isolated perfused rat liver. The first three drugs are substituted imidazoles, whereas ranitidine contains a furanyl nucleus. Isolated livers were perfused using a 100-ml, recycling, constant flow circuit for 4 hr. Antipyrine elimination was studied with or without an H2-receptor antagonist present. In all experiments, antipyrine concentrations declined monoexponentially. In control experiments (no other drug present), antipyrine clearance was 32.5 +/- 0.9 ml per hr. This was greatly reduced in the presence of cimetidine (clearance = 10.1 +/- 0.8 and 5.8 +/- 1.5 ml per hr after 1 and 5 mg doses, p less than 0.01) and burimamide (4.5 +/- 0.6 and 3.0 +/- 1.7 ml per hr, p less than 0.001). By contrast, neither oxmetidine nor ranitidine significantly altered antipyrine pharmacokinetics. These results indicate that the inhibitory effect on hepatic mixed-function oxidases is rapid in onset, independent of H2-receptor antagonist activity, and is not an inevitable consequence of the presence of an imidazole nucleus.

Animals↗
PubMedDate not supplied

Patients with reconstruction of craniofacial or intraoral defects: development of instruments to measure quality of life.

Patients with reconstruction of craniofacial or intraoral defects experience a profound impact on their quality of life (QOL). This impact on QOL is influenced by the patients' medical conditions and the treatment interventions. Instruments to measure general QOL have been available for many years. A major criticism of QOL instruments is that too often the questions are not specific to the particular problems of a disease or condition. A search of the literature regarding QOL measurement for patients with maxillofacial implant-supported prostheses produced a short list of instruments, none of which were sufficiently developed or suited to the patients involved in reconstructive treatment. This study was designed to develop pretreatment and posttreatment questionnaires for measuring QOL for patients with reconstruction of a craniofacial defect and patients with reconstruction of loss of specific intraoral structures utilizing an implant-supported prosthesis (e.g., severe resorption of the maxilla or mandible or both). The goal was to develop brief, targeted instruments for this specific patient population. The produced instruments were sensitive and easy to administer and score, and no disruption of clinical care occurred with the administration of the questionnaires. The instruments were used with equal success both in face-to-face interviews and via mail.

Dental Implantation, Endosseous↗
PubMedDate not supplied

Implants in the treatment of the maxillofacial patient.

Despite the apparent advantages provided by implants to the maxillofacial patient, complete documentation of these benefits is lacking in the literature. This review uses existing published material as a basis to discuss the efficacy of implant use in maxillofacial prosthetics and the biologic rationale of the procedures. The use of implants with bone-anchored hearing aids; in maxillofacial surgery; and in maxillary, mandibular, and facial defects is presented. Reliable and valid patient-based evidence of treatment success, as suggested by the NIH Consensus Conference of 1988, is needed.

Dental Implantation↗
PubMedDate not supplied

A new porcine bioprosthesis: in vitro and in vivo evaluation.

The Wessex porcine bioprosthesis exhibits satisfactory hydrodynamic performance and durability comparable to other clinical porcine valves. In vivo performance and pathological studies of explanted valves confirm adequate biodurability and haemodynamic performance. Early clinical results are satisfactory and encourage further study.

Angiography↗
PubMedDate not supplied

Patient satisfaction with implant-supported prostheses.

Forty-six female patients participated in a survey study to assess the relative health status impact of implant-retained oral prostheses and conventional complete dentures. They completed a structured questionnaire based on three valid and reliable treatment outcome measures: the Dental Functional Status Index (DFSI), the Rand Mental Health Index (MHI), and elements of the Sickness Impact Profile (SIP). The implant patients were associated with significantly better characteristics in areas of oral mechanical ability, signs and symptoms, and eating. A favorable tendency emerged with respect to communication, self-care, psychosocial functioning, and role performance. The data demonstrated that for some patients there are clinically important, pervasive advantages of implant therapy, in terms of improved physical, psychologic, and social functioning. The results supported the usefulness of self-report, dentopsychosocial indicators to assist in defining treatment needs, evaluating quality and consequence of care, and addressing cost-benefit issues.

Adult↗
PubMedDate not supplied

Diverse applications of the osseointegration technique: the maxillofacial patient.

The maxillofacial patient faces many challenges that go beyond those of edentulism. These obstacles leave the patient handicapped and socially vulnerable. One of the greatest of these difficulties is retention of the craniofacial prosthesis. Ingenious strategies based on experience have provided limited success. For selected patients, however, the osseointegrated implant has largely eliminated this vexing technical predicament, thus freeing the patient to enjoy a more normal lifestyle. The treatment indications for this service, the remaining unresolved patient problems, the new planning criteria, and the requirement to document success all point to the need for well-validated instruments to measure the effectiveness of this newly augmented service.

Humans↗