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Biomedical subjects

J S Henderson

Publications and source records attributed to J S Henderson.

17 recordsLinked to original sources
PubMed1995

The effects of smokeless tobacco extract on bone nodule formation and mineralization by chick osteoblasts in vitro.

Short-term exposure to smokeless tobacco extracts (STE) reportedly inhibits osteoblast metabolism. The objective of this study was to determine the effects of serial dilutions of a water-soluble extract of smokeless tobacco on osteoblast proliferation and their potential to form and mineralize bone nodules. STE significantly stimulated cell proliferation when diluted 10(2)-10(4) times; 10(3) and 10(4) dilutions produced the greatest effect. 10(2)-10(4) STE dilutions significantly increased alkaline phosphatase activity at day 7 but 10(6) STE dilutions significantly decreased it. 10(3) and 10(4) dilutions significantly increased bone nodule formation, but inhibited their mineralization. In contrast, 10(5) and 10(6) dilutions significantly decreased bone nodule formation, but increased their mineralization. Stimulation of in vitro bone nodule formation by STE was similar to that produced by 10(-7) M insulin-like growth factor 1 (IGF-1) in vivo. Heat and acid treatment of STE significantly reduced its beneficial effect on cell proliferation, suggesting that a peptide within STE may be responsible for enhancement of osteogenic cell proliferation. Thus, STE may contain a peptide capable of significantly stimulating osteoblast proliferation, differentiation and metabolism, similar to the effects of IGF-1. This peptide could have potential therapeutic benefits.

Analysis of Variance↗
PubMed1989

Intermittent clean self-catheterization in clients with neurogenic bladder resulting from multiple sclerosis.

For the client with multiple sclerosis (MS), urinary retention is a symptom that must be dealt with effectively because of the risk of life-threatening complications. Estimates of bladder involvement in these clients range as high as 73-90%. Intermittent clean self-catheterization (ICSC) is now being used by some clients with neurogenic bladder resulting from MS. This article addresses the success of, and problems presented by this technique to the person with MS as recorded in the literature and as related in three actual case studies.

Adult↗
PubMed1988

A pubococcygeal exercise program for simple urinary stress incontinence: applicability to the female client with multiple sclerosis.

Five women with multiple sclerosis (MS) and simple urinary stress incontinence were informally evaluated and taught a program of pubococcygeal exercises to determine if inadvertent loss of urine during activities which increase intraabdominal pressure could be improved or eliminated. A correlation seemed to exist between the client's ability to experience vaginal contraction during sexual climax and elimination or improvement of simple urinary stress incontinence using a pubococcygeal exercise program. The purpose of this article is to encourage nurses to consider a pubococcygeal teaching program for treatment of simple urinary stress incontinence in female clients with MS who do experience vaginal contraction during sexual climax.

Exercise Therapy↗
PubMed1987

Rapid calcium release from cardiac sarcoplasmic reticulum vesicles is dependent on Ca2+ and is modulated by Mg2+, adenine nucleotide, and calmodulin.

A subpopulation of canine cardiac sarcoplasmic reticulum vesicles has been found to contain a "Ca2+ release channel" which mediates the release of intravesicular Ca2+ stores with rates sufficiently rapid to contribute to excitation-contraction coupling in cardiac muscle. 45Ca2+ release behavior of passively and actively loaded vesicles was determined by Millipore filtration and with the use of a rapid quench apparatus using the two Ca2+ channel inhibitors, Mg2+ and ruthenium red. At pH 7.0 and 5-20 microM external Ca2+, cardiac vesicles released half of their 45Ca2+ stores within 20 ms. Ca2+-induced Ca2+ release was inhibited by raising and lowering external Ca2+ concentration, by the addition of Mg2+, and by decreasing the pH. Calmodulin reduced the Ca2+-induced Ca2+ release rate 3-6-fold in a reaction that did not appear to involve a calmodulin-dependent protein kinase. Under various experimental conditions, ATP or the nonhydrolyzable ATP analog, adenosine 5'-(beta, gamma-methylene)triphosphate (AMP-PCP), and caffeine stimulated 45Ca2+ release 2-500-fold. Maximal release rates (t1/2 = 10 ms) were observed in media containing 10 microM Ca2+ and 5 mM AMP-PCP or 10 mM caffeine. An increased external Ca2+ concentration (greater than or equal to 1 mM) was required to optimize the 45Ca2+ efflux rate in the presence of 8 mM Mg2+ and 5 mM AMP-PCP. These results suggest that cardiac sarcoplasmic reticulum contains a ligand-gated Ca2+ channel which is activated by Ca2+, adenine nucleotide, and caffeine, and inhibited by Mg2+, H+, and calmodulin.

Adenine Nucleotides↗
PubMed1986

Single channel and 45Ca2+ flux measurements of the cardiac sarcoplasmic reticulum calcium channel.

Purified canine cardiac sarcoplasmic reticulum vesicles were passively loaded with 45CaCl2 and assayed for Ca2+ releasing activity according to a rapid quench protocol. Ca2+ release from a subpopulation of vesicles was found to be activated by micromolar Ca2+ and millimolar adenine nucleotides, and inhibited by millimolar Mg2+ and micromolar ruthenium red. 45Ca2+ release in the presence of 10 microM free Ca2+ gave a half-time for efflux of 20 ms. Addition of 5 mM ATP to 10 microM free Ca2+ increased efflux twofold (t1/2 = 10 ms). A high-conductance calcium-conducting channel was incorporated into planar lipid bilayers from the purified cardiac sarcoplasmic reticulum fractions. The channel displayed a unitary conductance of 75 +/- 3 pS in 53 mM trans Ca2+ and was selective for Ca2+ vs. Tris+ by a ratio of 8.74. The channel was dependent on cis Ca2+ for activity and was also stimulated by millimolar ATP. Micromolar ruthenium red and millimolar Mg2+ were inhibitory, and reduced open probability in single-channel recordings. These studies suggest that cardiac sarcoplasmic reticulum contains a high-conductance Ca2+ channel that releases Ca2+ with rates significant to excitation-contraction coupling.

Animals↗
PubMed1976

Interference by cortisone with endotoxin's adjuvator action on transplantation of a mouse tumour.

Observations on the in vivo plating of mouse mammary tumour are extended by making counts of tumours at a significantly earlier phase of development than in previously reported work. In the experiments now described, most of the growth of the tumours has been without benefit of stroma. The noteworthy economy of the experimental method is discussed. The persistence of endotoxin's adjuvator effect on such tumour counts is tested in the face of gamma irradiation and cortisone. Cortisone, it is found, offsets endotoxin's adjuvator action; irradiation does not. Antagonism between endotoxin and cortisone, in this system with tumour cells plated in vivo, seems to indicate that endotoxin's enhancing effect depends more on inflammatory than on immunological factors.

Animals↗
PubMed1970

Peyton Rous.

Explore the source record for details and available documents.

History of Medicine↗
PubMed1968

Endotoxin as adjuvator to the transplantation of a mouse mammary tumor.

The mouse mammary tumor MT 296 was used in a further series of experiments on the implantation of tumor, plated out in vivo, from suspensions of individual cells. Lipopolysaccharide from S. typhosa was shown to exert an adjuvator influence. But this adjuvator, an endotoxin, had no direct effect on the suspended tumor cells, unlike the liver preparations previously reported. Lipopolysaccharide from S. typhosa was shown to act on the host. It made the host's connective tissue expanses more susceptible to successful implantation by the tumor cells. It did this only if present at the time these connective tissue expanses were split. The increased susceptibility, caused by splitting the connective tissue expanses in the presence of lipopolysaccharide, declined quickly after 24 hr. The structural changes wrought upon the connective tissues by splitting them in the presence of lipopolysaccharide are described. They show kinship to a Schwartzman reaction of the local type. Their possible role in the adjuvator effect on the plating of single cell suspensions of this tumor is discussed.

Adjuvants, Immunologic↗
PubMed1967

Adjuvators to the propagation of mouse mammary tumor cells on expanses of subcutaneous tissue.

The cells of a mouse mammary cancer were obtained with enzymes in suspensions which could be filtered to exclude all which were not single and most which were already dead. Heavy suspensions of these individual cells were plated over the dorsal subcutaneous expanses of female weanling mice where they implanted and grew to form coalescent tumors covering the back more or less entirely. Sparser suspensions, similarly plated (a) gave rise to fewer tumors, and (b) gave rise to tumors reaching measurable size later. These two consequences of sparser plating left room for the testing of adjuvators to transplantation. Adjuvator effects were obtained by splitting the subcutaneous expanses beforehand and by injecting liver along with the plated cells. Through 28 plated generations over 4 yr the tumor maintained completely stable, morphological heterogeneity. These findings with a complex tumor indicate strongly that its heterogeneity comes not from repeated cellular mutation late in its development, but from diverse potentiality to give rise to cells of specific and differing character, inherent in its individual cells at the time of its multicellular origin.

Animals↗
PubMedDate not supplied

Effects of a prenatal teaching program on postpartum regeneration of the pubococcygeal muscle.

A quasi-experimental design was used to compare postpartum perineometer readings of an experimental group of 32 women receiving a prenatal teaching program for the use of Kegel exercises with a control group of 30 women for whom the instructional program was omitted. All subjects received postpartum instruction from a pre-existing program presented by hospital staff. Significantly higher mean postpartum perineometer readings (t = 4.07; P less than .01) were found for the experimental group than for the control group, which supported the hypothesis that women who are offered the prenatal program for the use of Kegel exercises during the third trimester of pregnancy and are instructed on Kegel exercises by the staff during the hospitalized postpartum period will have significantly higher readings on the perineometer at the postpartum visit than those women for whom the prenatal program is omitted.

Female↗
PubMedDate not supplied

Age as a variable in an exercise program for the treatment of simple urinary stress incontinence.

This study compared the effectiveness of biofeedback on pubococcygeal muscle strengthening and simple urinary stress incontinence in older and younger women. Women aged 55 years and older and women younger than 55 years of age were taught Kegel exercises, using biofeedback, for the treatment of simple urinary stress incontinence. Eighty percent of the younger group and 67% of the older group eliminated stress incontinence. Also, the younger women required less pubococcygeal strength than the older women to control incontinence.

Adult↗