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Biomedical subjects

J F Collins

Publications and source records attributed to J F Collins.

At least 199 records · Page 11Linked to original sources
PubMed1978

A case report in a Rural Health Center.

An experiment utilizing nurse practitioners in the delivery of health care in a rural Nebraska community is described. In spite of several reorganizations, over a 2 1/2-year period of study, the project failed in terms of patient utilization. Visit rates began at 300 per month and increased to a high of 825 until the community perceived that the nurse practitioner was interposed between themselves and the primary physician. Rates then dropped to 375 and the community withdrew from the project. Implications for rural health projects using ancillary personnel are discussed.

Delivery of Health Care↗
PubMed1978

The use of retirees to evaluate occupational hazards. II. Comparison of cause specific mortality by work area.

This article compared the results of mortality studies in three work areas of the steel industry for the total cohort of workers and for the retirees. This was done to determine further the usefulness and the limitations of retiree studies for occupational mortality studies. The major findings are: 1. Retiree studies detect occupational hazards such as respiratory cancers and nonmalignant respiratory diseases, although the estimated average relative risk will tend, for obvious reasons, to be greater than for the total cohort. 2. Some problems associated with the use of retirees for occupational mortality studies were also discussed. These problems included small sample sizes, the retiree study not indicating significant excess deaths from certain diseases because the excess mortality took place in the younger ages, and differences between the estimates of risk for the retiree study and the total cohort study. 3. The estimates of risk for the studies using all men over age 65 did not vary from the estimates of risk for the total cohort as much as the risks from the retirees did. However, other than the variation seen in the estimates of risk, the exclusion of nonretirees from the retiree study did not seem to affect the overall conclusions. Based on the findings of this study, it was concluded that retiree studies may sometimes be useful tools in detecting occupational hazards when cost and time definitely preclude more comprehensive studies, but that one should be aware of the greater possibility of spurious negative findings due to the limited age group being studied and the smaller sample sizes.

Aged↗
PubMed1976

A randomized controlled trial of home care: clinical outcome for five surgical procedures.

The clinical function of patients receiving home care after five surgical procedures was assessed. Hospital patients who normally would have received minimal nursing care at the end of their hospital stay were randomly assigned to an experimental home-care group or a control group who were discharged from hospital after the normal length of stay. Comprisons of "untoward events" (discomfort, infection, delayed healing, or complications) are reported for the two groups in five surgical categories (varicose vein stripping, herniorrhaphy, cholecystectomy, anal and rectal operations and abdominal hysterectomy) where the home-care program operated efficientyl. No apparent differences in the rates of untoward events were noted between hospital and home-care groups. It is concluded that home care should be considered for reasons other than clinical function, such as socio-economic functioning, the wishes of the patient, or more efficient use of hospital space.

Anal Canal↗
PubMed1975

Characterization of cell-free synthesis of collagen by lung polysomes in a heterologous system.

In normal lung growth, post-pneumonectomy lung growth, and in possibly several lung disorders, there are marked alterations in the density of collagen and changes in the rate of synthesis of collagen relative to the synthesis of other lung proteins. To provide a technology to begin to understand these changes at the molecular level, polysomes were prepared from rabbit lung and translated in a heterologous cell-free system including rabbit reticulocyte 0.5 M KCl ribosomal wash fraction and liver tRNA. Collagen was shown in the cell-free product by collagenase sensitivity, hydroxylation of incorporated proline by peptidyl prolyl hydroxylase, agarose gel chromatography, and sodium dodecyl sulfate acrylamide gel electrophoresis. The cell-free system was optimized with respect to K+, Mg2+, amino acids, and ribosomal wash fraction and used under conditions where total protein synthesis and collagen synthesis are linear with respect to time and amount of polysomes. Under these conditions, collagen synthesis was directed almost entirely by polysomes derived from the endoplasmic reticulum. Polysomes isolated from late fetal lung directed collagen synthesis at twice the rate (per polysome) as those polysomes isolated from adult lung. Similar changes were seen if lung tRNA replaced liver tRNA and if lung ribosomal wash fraction replaced reticulocyte wash fraction. Although these changes in cell-free lung collagen synthesis with tissue explants, further studies will have to be carried out to determine whether, in fact, age-related alterations in control of lung collagen synthesis are truly explained by these findings.

Aging↗
PubMed1975

Tetramethylenedisulphotetramine: an inhibitor of gamma-aminobutyric acid induced depolarization of the isolated superior cervical ganglion of the rat.

Tetramethylenedisulphotetramine (TETS), a potent convulsant, antagonized the depolarizing action gamma-aminobutyric acid (GABA) in the isolated superior cervical ganglion of the rat. No antagonism of responses to the cholinomimetic agent carbachol was observed. TETS appeared to act in a non-competitive manner and was reversible. Its activity profile was comparable to that of bicuculline in the same tissue except that the latter appears to act in a competitive manner.

Aminobutyrates↗
PubMed1975

Collagen in the lung: development of a technology applicable to human lung disease.

Techniques have been developed to quantitate in vitro the types, rates and fates of collagen synthesized by animal and human lung. Studies are continuing in our laboratory to apply these techniques to investigate important lung disorders, including: (1) classification of the fibrotic lung disorders by the types of collagen synthesized; (2) development of an in vitro drug evaluation system to determine, in a lung biopsy, which drugs are useful in reducing the fibrotic process for a patient with interstitial disease; and (3) investigations of the influence of serum proteins on lung connective tissue synthesis and proteolysis.

Animals↗
PubMed1974

Gross map distances and Hfr transfer times in Escherichia coli K-12.

Hfr strains B4 and B8 transfer the Escherichia coli chromosome in opposite directions, each transferring lac(+) as the last known marker. They were mated in concurrent crosses with the proA leu metE lys trp purE lac strain chi462. Analysis of the time of entry values for these markers showed that Hfr strain B8 transfers the whole chromosome more rapidly than does Hfr strain B4. In both crosses, the rate of transfer observed decelerates. If deceleration occurs as a function of the amount of chromosome transferred, the data are consistent with the markers examined being very accurately placed on the Taylor-Trotter map of the E. coli K-12 genome.

Chromosome Mapping↗
PubMed1974

Quantal behavior of a diffusible factor which initiates septum formation at potential division sites in Escherichia coli.

Analysis of nucleated cell size in a minicell-producing strain of Escherichia coli and in its parental strain shows that the two distributions are considerably different. A model is proposed to account for this difference. The model states that: (i) in the mutant population, the cell poles are available as potential division sites in addition to the normally located division sites; (ii) the probability of a division occurring at any of the potential division sites is equal; and (iii) only enough "division factor" arises at each unit cell doubling to permit a single division. This factor is utilized entirely in the formation of a single septum. Thus, the occurrence of a polar division with the production of an anucleate minicell (which occurs only in the mutant strain) prevents the occurrence of a non-polar division, with the result that the average nucleated cell length is increased in minicell-producing strains. The model has been used to construct a theoretical population, and a number of parameters of the real and theoretical populations have been compared. The two populations are very similar in all of the parameters measured.

Cell Division↗