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Biomedical subjects

D B Smith

Publications and source records attributed to D B Smith.

At least 271 records · Page 15Linked to original sources
PubMed1978

Frozen autogenous mandible as an immediate replacement graft.

A study in animals was designed to examine the feasibility of grafting autogenous frozen mandible. Two groups of animals were used. In the first group, periosteum was elevated from the bone before resection. In the second group, the periosteum was removed with the resected specimen. Osteogenesis was shown by clinical, radiographic, fluorescence, and histologic studies in both groups of animals. The same technique was performed in nine humans with carcinomas that involved the mandible. The results were encouraging. We believe that immediate or delayed reconstruction with autogenous frozen mandible in a patient undergoing ablative surgery of the head and neck with involvement of the bone may offer the patient, as well as the surgeon, another acceptable treatment modality.

Animals↗
PubMed1977

Nucleotide sequence organisation in the rye genome.

Nucleotide sequence organisation in the genome of rye, Secale cereale, has been studied using renaturation kinetics and S1 nuclease digestion of the renatured products. Approximately 25 to 30% of the genome consists of very slowly renaturing, possibly single copy sequences. Most, if not all, of these sequences are interspersed between repeated sequences and are between 400 and 3500 nucleotide pairs long. Approximately 70 to 75% of the genome consists of repeated sequences. The more highly diverged repeated sequences (30% of the genome) which fail to renature under highly stringent renaturation conditions range from 500 to more than 5000 base pairs long and are interspersed in the chromosomes with less diverged repeated sequences (40% of the genome) which are usually less than 800 nucleotide pairs long. Four percent of the genome consists of very rapidly reannealing sequences which may be inverted duplications. These sequences may be in clusters distributed through at least 30% of the genome.

Base Sequence↗
PubMed1977

A cooperative pharmacy project: an autopsy on a community health intervention.

An attempt to implement a cooperative pharmacy project within a public housing project for the elderly is described. It was designed to provide low-cost prescriptions and pharmaceutical counseling as well as a coordinated record system for the elderly residents and other members of the senior citizens association. The resistance of local pharmacists and others caused substantial alterations to be made, eliminating the more consumer-oriented elements and emphasizing the more professional and technical aspects. Because of insufficient participation by the pharmacists and the consumers, the project died. The reasons for this failure are explored.

Aged↗
PubMed1977

Hyperpolymer formation during renaturation of DNA from genomes with different sequence organisation.

Hyperpolymer formation during the renaturation of DNAs from wheat, calf and E. coli was studied using hydroxyapatite chromatography, electron microscopy and S1 nuclease. Large hyperpolymers could not be eluted from hydroxyapatite with 0.5 M phosphate buffer at 60 degrees C. Large proportions of wheat and E. coli DNAs were incorporated into hyperpolymers when fragments 650 nucleotides long were renatured. A much smaller proportion of calf DNA was incorporated under equivalent conditions. Greater proportions of calf DNA accumulated in hyperpolymers only when longer fragments were incubated. Electron microscopy indicated no obvious differences in the basic structures of hyperpolymers formed by the three DNAs and confirmed the quantitative differences in hyperpolymer formation found by hydroxyapatite chromatography. It is concluded that the proportions and arrangement of the repeated sequences in the chromosomes of higher organisms determine the extent of rapid hyperpolymer formation during DNA renaturation in vitro.

Animals↗
PubMed1977

The distribution of physician extenders.

As part of the Medicare Physician Extender Reimbursement Study, a mail survey was conducted of 5,572 physician extenders (PEs) to identify potential study participants. Analysis of survey results indicates that PEs are distributed disproportionately more often than physicians to primary care practices and to rural low income areas. However, there are substantial differences among types of PEs with regard to practice location and practice arrangement. The relationship between these findings and the distribution of other medical manpower and innovations is then discussed.

Nurse Practitioners↗
PubMed1977

Lip and laryngeal flaps for reconstruction of the floor of the mouth following glossectomy.

Following glossectomy, the reconstruction of the floor of the mouth is a major problem facing the head and neck surgeon. We have devised split-lip and laryngeal mucosal flaps for this. In selected patients, they have a significant advantage over distant skin flaps. The initial postoperative deformity, from the lip being drawn into the mouth, is corrected by a secondary operation with split-skin graft reconstruction of the vestibule. These lip and laryngeal flaps do not require a delay procedure prior to the cancer surgery, and the operating time is considerably reduced. The cosmetic and functional results have been satisfactory.

Glossectomy↗
PubMed1977

The hospital support game revisited.

This paper updates a well-known case study in which Ray Elling examined the failure of community health planning in a medium-sized American city. During the period described by Elling, the city's hospitals had managed to resist efforts to rationalize the system by marshalling the support of their respective constituents. This political gamesmanship gave way in the late sixties and early seventies to greater cooperation and a significant consolidation of the hospitals. The authors hypothesize that an important factor influencing this development was the change in medical technology. The effects on the community's health care delivery are also discussed.

Delivery of Health Care↗
PubMed1976

Interspersion of different repeated sequences in the wheat genome revealed by interspecies DNA/DNA hybridisation.

The repeated sequences in oats DNA have been used to study chromosomal repeated sequence organisation in wheat. Approximately 75% of the wheat genome consists of repeated sequences but only approximately 20% will form heteroduplexes with repeated sequences from oats DNA at 60 degrees C in 0.18 M Na+. The proportion of wheat DNA that forms heteroduplexes with oats DNA is shown to be independent of the wheat DNA fragment length. However, the proportion of wheat DNA that is retained with the heteroduplexes when fractionated on hydroxyapatite is very dependent upon the wheat fragment length up to 3500 nucleotides. This is because more non-renatured wheat DNA is attached to the heteroduplexes with longer fragments. The results indicate that the repeated sequences in the wheat genome homologous to repeated sequences in oats are not clustered in the chromosomes but distributed amongst other repeated and possible non-repeated sequences.

Base Sequence↗
PubMed1976

Characterization of tryptic peptides from porcine haptoglobin light chain and an amino acid sequence.

The tryptic peptides derived from porcine haptoglobin light chains have been separated and characterized by composition, chromatography, electrophoretic mobility, and partial sequencing. Depending on homology with the corresponding human polypeptide, the amino acid sequence of the chain is proposed. Twenty differences from the human chain are indicated in the total of 84 residues.

Amino Acid Sequence↗
PubMed1976

The purification of porcine haptoglobin by affinity chromatography with concanavalin A-Sepharose.

Methods designed for the isolation of human haptoglobin (Hp) were found insufficient when applied to pig plasma due to the formation of a material tentatively identified as albumin dimer. Small scale separation is possible by preparative polyacrylamide gel electrophoresis. Larger scale purification from nonglycoprotein contaminants such as albumin dimer is achieved by affinity chromatography using immobilized concanavalin A. Porcine haptoglobin is microheterogeneous. More than 14 components, partially resolveable by gel filtration, were detected.

Animals↗
PubMed1976

The preparation of human hemoglobin alpha-subunit and a study of its monomer-dimer association.

An improved procedure for the isolation of the alpha-subunit of human hemoglobin is described. The monomer-dimer equilibrium in alpha-subunit solutions has been studied by boundary analysis in gel filtration, sedimentation velocity, sedimentation equilibrium, and cross-linking with dimethyl adipimidate. A dissociation constant has been determined from the sedimentation equilibrium data. The reaction with haptoglobin of cross-linked alpha-subunit showed that the dimer fraction wound form a stable complex.

Amino Acids↗
PubMed1976

The reaction between hemoglobin alpha-subunit and haptoglobin.

The interaction between human hemoglobin alpha-subunit and porcine haptoglobin was investigated by polyacrylamide gel electrophoresis, gel filtration chromatography, sedimentation through excess alpha-subunit and gel filtration in an alpha-subunit-containing medium. No interaction was detected by the first two methods indicating dissociation of the complex during the application of these separation techniques. The latter two methods, in which the complex is studied in a medium of excess subunits, showed that haptoglobin became saturated with the binding of two alpha-subunits.

Animals↗