Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 20
Filter
Add more filters










Publication year range
1.
Obes Sci Pract ; 4(4): 299-307, 2018 Aug.
Article in English | MEDLINE | ID: mdl-30151225

ABSTRACT

OBJECTIVE: Multicomponent lifestyle modification interventions designed for gestational and early postnatal periods may be key to preventing obesity in children. The primary objective of the study was to determine if infant growth outcomes differed between treatment arms of an 18-month, maternal, infant and early childhood home visiting project. METHODS: Pregnant women at least 18 years of age, less than 19 weeks pregnant and residing in a lower Mississippi Delta county were recruited between March 2013 and December 2014. Postnatal data were collected from 24 experimental and 30 control participants between September 2013 and May 2016. Infant growth outcomes were modelled as time-to-event data using Kaplan-Meier survival curves with log-rank tests to determine if survival curves differed between treatment arms. RESULTS: Retention rates for the experimental and control arms were 88% (21/24) and 83% (25/30), respectively. Approximately three-fourths of infants in both treatment arms were classified as overweight and experienced rapid weight gain during the first 12 months of life. No differences between median times neither to classification as overweight (3-4 months) nor to experiencing rapid weight gain (6-7 months) were observed between treatment arms. CONCLUSIONS: As compared with a standard educational (control) curriculum, an educational curriculum enhanced with diet and physical activity components was not effective at improving infant growth outcomes.

3.
Transpl Int ; 5 Suppl 1: S487-9, 1992.
Article in English | MEDLINE | ID: mdl-14621855

ABSTRACT

We evaluated the efficacy of interleukin 2 (DAB486)-toxin (IL-2-diphtheria toxin fusion protein; IL-2-toxin) in combination with RS-61443 to prolong murine thyroid allograft survival. B10.BR thyroid allografts were transplanted beneath the renal subcapsule in recipient (C57BL/10 mice and graft survival determined 21 days later. Treatment with IL-2-toxin (25 microg/day for 14 days) was unable to prolong graft survival significantly. RS-61443 treatment (21 days) achieved significant graft prolongation only at doses of 300 mg/kg daily or greater. When both drugs were used in combination (IL-2-toxin, 25 microg/day for 14 days RS-61443 200 mg/kg daily for 21 days), statistically significant (P < 0.0001) graft prolongation was obtained. Our results suggest that IL-2-toxin in combination with subtherapeutic RS-61443 levels significantly prolongs murine thyroid allograft survival. IL-2-toxin and RS-61443, because of their unique and complementary mechanisms, hold promise for more selective immunosuppression.


Subject(s)
Diphtheria Toxin/therapeutic use , Interleukin-2/therapeutic use , Mycophenolic Acid/analogs & derivatives , Mycophenolic Acid/therapeutic use , Recombinant Fusion Proteins/therapeutic use , Thyroid Gland/transplantation , Animals , Immunosuppressive Agents/therapeutic use , Immunotoxins/therapeutic use , Mice , Mice, Inbred C57BL , Mice, Inbred Strains , Models, Animal , Thyroid Gland/immunology , Thyroid Gland/pathology , Transplantation, Homologous/immunology , Transplantation, Homologous/pathology
5.
Transplantation ; 49(5): 971-5, 1990 May.
Article in English | MEDLINE | ID: mdl-2336713

ABSTRACT

Organ culture of murine thyroid allografts in hyperbaric oxygen (95% O2 at 25 psi, 37 degrees C) for 48 hr, results in prolonged allograft survival. Endocrine tissues can be cultured at 37 degrees C--however, this method may not be applicable to vascularized organs at normothermia. The aim of this study was to apply hyperbaric oxygen culture (HOC) under organ preservation conditions (hypothermia, UW solution) that have been shown to be successful in clinical organ transplantation. B10BR/SGSNJ murine thyroid lobes were transplanted beneath the kidney capsule of C57BL/10J recipients. Thyroids were cultured in Eagle's MEM at 37 degrees C (controls) and at 5 degrees C, under hyperbaric conditions (95% O2:5% CO2, 25 psi). Alternatively, thyroids were cultured in UW solution (+/- allopurinol/GSH) at 5 degrees C, for up to 7 days. Graft survival was determined 21 days posttransplant by 125I uptake and by histology. In Eagle's MEM, HOC at 37 degrees C/48 hr and 5 degrees C/7 days, resulted in 93% and 20% allograft survivals, respectively. In UW solution (- allopurinol/glutathione [GSH]), HOC at 5 degrees C/7 days resulted in 83% allograft survival: immunoperoxidase staining showed a decrease of MHC class I alloantigen expression. Oxygen free radical scavenger (allopurinol/GSH) addition to the UW solution diminished this effect and suggested an oxygen free radical-mediated mechanism in immunoalteration. These results demonstrate that HOC for 7 days reduced the antigenicity and immunogenicity of murine thyroid grafts under conditions that simulate organ preservation. Hypothermic hyperbaric oxygen culture conditions require testing in a higher animal species and in vascularized grafts to determine if this method can be applied to whole-organ transplantation.


Subject(s)
Organ Preservation Solutions , Organ Preservation/methods , Thyroid Gland/transplantation , Adenosine , Allopurinol , Animals , Cold Temperature , Free Radicals , Glutathione , Graft Survival , Histocompatibility Antigens Class I/analysis , Hyperbaric Oxygenation , Insulin , Mice , Mice, Inbred Strains , Raffinose , Solutions , Thyroid Gland/immunology , Thyroid Gland/pathology , Time Factors
7.
J Surg Res ; 46(6): 625-32, 1989 Jun.
Article in English | MEDLINE | ID: mdl-2525209

ABSTRACT

The limited clinical success of human fetal pancreas (HFP) transplantation may be related to graft toxicity caused by immunosuppressant agents. This study describes the effects of prednisone (PRED), azathioprine (AZA), and cyclosporine A (CSA) on HFP tissue in vitro and in vivo. To assess in vitro function, fresh HFP explants (1-2 mm3; 16-21 weeks gestational age) were prepared and cultured 72 hr in supplemented Ham's medium containing varying concentrations of each drug. Insulin release in response to high glucose (17 mM) and theophylline (10 mM) challenge was determined and compared to basal release in low glucose (3 mM) buffer. No significant difference in insulin release was observed between culture control tissue and drug-cultured tissue throughout the concentration range (10(-8) -10(-4) M; P greater than 0.05). To assess in vivo function, cyropreserved HFP explants were transplanted under the kidney capsule of streptozotocin-induced diabetic nude mice. Mice were immunosuppressed with PRED (1 mg/kg), AZA (1 mg/kg), CSA (30 mg/kg), or combined triple drug therapy (COMBO), and glucose levels followed weekly. Hyperglycemia reversal and insulin withdrawal were observed in all drug groups [PRED (4/6), AZA (4/6), CSA (2/4), COMBO, (2/4)] and were not statistically different from control (5/8; P greater than 0.8). Time to insulin withdrawal was significantly different from control (12.2 +/- 2.2 weeks; P less than 0.05) only for AZA (10 +/- 0 weeks; PRED, 12.3 +/- 2.6 weeks; CSA, 11 +/- 0 weeks; COMBO, 15 +/- 0 weeks). Additionally, oral glucose tolerance tests in all groups were equivalent to nondiabetic controls. We were unable to demonstrate PRED, AZA, or CSA toxicity on HFP.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Azathioprine/adverse effects , Cyclosporins/adverse effects , Prednisone/adverse effects , Animals , Culture Techniques , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Experimental/therapy , Fetus/drug effects , Humans , Insulin/metabolism , Mice , Mice, Nude , Pancreas/drug effects , Pancreas Transplantation , Streptozocin
8.
Diabetes ; 38(4): 448-53, 1989 Apr.
Article in English | MEDLINE | ID: mdl-2494092

ABSTRACT

To obtain sufficient quantities of human fetal pancreatic tissue (HFP) for transplantation, long-term storage of the tissue must be achieved. The functional viability of HFP after cryopreservation by stepwise addition of dimethyl sulfoxide was determined. Human fetal pancreas explants (1-2 mm3; gestational age 16-21 wk) were prepared and slowly cooled (0.25 degrees C/min) to -40 degrees C before placement in liquid nitrogen. After rapid thaw (37 degrees C) and overnight culture, insulin release in response to high glucose and theophylline challenge determined in vitro functional viability. No difference was found between the responses of fresh and cryopreserved tissue (fresh 29.2 +/- 3.0 ng/mg tissue, cryopreserved 29.9 +/- 3.3 ng/mg tissue; P greater than .1). Diabetic BALB/c nu/nu mice transplanted with cryopreserved HFP returned to normoglycemia in 11 +/- 2 wk (range 8-15 wk). Oral glucose tolerance tests indicated in vivo serum glucose control equivalent to or better than that of nondiabetic control mice (peak serum glucose of nondiabetic mice 164 +/- 66 mg/dl, of cryopreserved grafted mice 180 +/- 67 mg/dl; P greater than .8). In vitro insulin release of cryopreserved grafted tissue demonstrated that the tissue had differentiated and matured and was now capable of responding to high-glucose challenge (39.3 +/- 11.5 ng insulin released/mg tissue). The results described herein are the first demonstration that cryopreserved HFP maintains the in vivo capacity to differentiate and mature and the capacity to reverse diabetes in an animal system.


Subject(s)
Diabetes Mellitus, Experimental/surgery , Islets of Langerhans Transplantation , Pancreas Transplantation , Transplantation, Heterologous , Animals , Blood Glucose/metabolism , Diabetes Mellitus, Experimental/blood , Fetus , Freezing , Gestational Age , Glucose/pharmacology , Humans , Insulin/metabolism , Insulin Secretion , Islets of Langerhans/drug effects , Islets of Langerhans/metabolism , Kinetics , Mice , Mice, Nude , Nephrectomy , Organ Culture Techniques , Pancreas/cytology , Pancreas/embryology , Tissue Preservation/methods
11.
Diabetes ; 38 Suppl 1: 172-5, 1989 Jan.
Article in English | MEDLINE | ID: mdl-2463195

ABSTRACT

The toxic effects of FK-506 (FK), a newly discovered immunosuppressive agent isolated from Streptomyces tsukubaensis, were studied in the human fetal pancreas (HFP) system. Human fetal pancreas explants (14-21 wk gestation) were cultured up to 72 h with either 10(-10) to 10(-7) M FK or 10(-8) to 10(-5) M cyclosporin A (CsA), then examined histologically and functionally with a stimulated insulin-release assay. Additionally, FK and CsA were tested for the ability to suppress cell-mediated immunity with a human mixed-lymphocyte reaction (MLR). Previous studies have demonstrated that near-complete immunosuppression is obtained with FK at 10(-8) M and CsA at 10(-6) M. When cultured up to 72 h throughout the concentration range, neither FK nor CsA altered HFP cellular architecture, and indirect immunoperoxidase staining for insulin demonstrated no change in quantity or distribution of insulin-producing beta-cells compared with control tissue. Drug-cultured HFP also retained the ability to release insulin in response to a glucose/theophylline challenge. Finally, 50% inhibition of a human MLR was achieved with FK at 2 x 10(-9) M and CsA at 2 x 10(-7) M, demonstrating the 100-fold greater potency of FK. Our results suggest that further work with FK will show that this immunosuppressive agent can be used with HFP transplantation into diabetic patients without toxicity to HFP.


Subject(s)
Pancreas/embryology , Pyridines/toxicity , Culture Techniques , Cyclosporins/pharmacology , Female , Humans , Lymphocyte Culture Test, Mixed , Pancreas/drug effects , Pregnancy , Pregnancy Trimester, Second , Tacrolimus
12.
Transplantation ; 47(1): 24-7, 1989 Jan.
Article in English | MEDLINE | ID: mdl-2911873

ABSTRACT

Hyperbaric oxygen (95%, O2, 25 psi, 48-hr culture) resulted in prolonged thyroid allograft (B10.A) survival in both primary and sensitized recipients (B10.AQR). Recipients receiving noncultured thyroid allografts uniformly rejected the graft by 35 days, while 100% of cultured grafts survived. Noncultured thyroid grafts transplanted to skin-graft-primed recipients were rejected by 21 days. In contrast, 86% of cultured grafts transplanted to primed recipients were still functioning at 35 days. Donor spleen cells or peritoneal exudate cells transferred at the time of thyroid transplant were unable to stimulate cultured allograft rejection. Allografts histologically examined 35 days after transplant revealed, in some grafts, focal cellular infiltrates adjacent to normal, uninfiltrated tissue. To determine if tissue modification was the mechanism of prolonged allograft survival, hyperbaric-oxygen-cultured thyroids were examined for MHC class I expression. Immunoperoxidase staining with monoclonal antibody to MHC class I molecules showed that cultured thyroids were unstained in contrast to fresh thyroids that were uniformly stained. Cytotoxic T lymphocytes specific for H-2Kk administered 10 days following thyroid transplant were unable to eliminate cultured grafts (80% survival) but completely destroyed noncultured grafts. These results indicate that hyperbaric oxygen culture altered MHC class I expression such that it was no longer detectable by monoclonal antibody or cytotoxic T lymphocytes. Thus, the mechanism, explaining graft prolongation after hyperbaric culture in addition to passenger cell depletion, may be alteration of graft antigenicity such that the graft is no longer perceived as foreign.


Subject(s)
Histocompatibility Antigens Class I/immunology , Thyroid Gland/transplantation , Animals , Graft Survival , Hyperbaric Oxygenation , Mice , Mice, Inbred Strains , Organ Culture Techniques , Organ Preservation , Thyroid Gland/immunology
14.
J Lab Clin Med ; 108(1): 23-9, 1986 Jul.
Article in English | MEDLINE | ID: mdl-3011931

ABSTRACT

Ambient hydrogen ion concentration modulates the effects of angiotensin II (AII) on adrenal aldosterone secretion, but the mechanism of this modulation is unknown. We examined the influence of pH on AII receptors and responses in bovine adrenal glomerulosa cells. Lowering pH from 7.4 to 6.8 increased AII binding 20.5% and increased maximal All-stimulated aldosterone secretion 43%. By contrast, at pH 8.0, All binding and stimulation of aldosteronogenesis fell by 56.6% and 39%, respectively. Effects on All binding intermediate to these changes were observed at pH 7.1 and 7.7. Similar effects of altered pH were observed on All binding to a crude membrane fraction of bovine glomerulosa cells. Analysis indicated that pH primarily affected receptor number rather than affinity. In studies of proposed postreceptor mediators of All actions, pH had no effect on All stimulation of phosphatidylinositol turnover or All inhibition of calcium influx. The results show that pH affects All interaction with its receptors. The larger magnitude of the change in aldosterone compared with receptor binding suggests that a postreceptor step is also altered by pH; however, this postreceptor step is not reflected in calcium influx or phospholipid turnover.


Subject(s)
Adrenal Glands/metabolism , Aldosterone/metabolism , Angiotensin II/pharmacology , Hydrogen-Ion Concentration , Receptors, Angiotensin/metabolism , Receptors, Cell Surface/metabolism , Animals , Calcium/metabolism , Cattle , Dose-Response Relationship, Drug , In Vitro Techniques , Phosphatidylinositols/metabolism
15.
Life Sci ; 32(14): 1573-81, 1983 Apr 04.
Article in English | MEDLINE | ID: mdl-6300585

ABSTRACT

We examined the effects of cholesteryl hemisuccinate on membrane fluidity and angiotensin II (AII) actions in bovine adrenal glomerulosa cells. Incubating cells with cholesteryl hemisuccinate decreased membrane fluidity and markedly inhibited AII binding. The effect on binding was characterized by a decrease in AII receptor number. The effects of AII on phosphatidyl inositol turnover and calcium fluxes, proposed intermediaries of AII actions on aldosterone secretion, were less impaired than AII binding by cholesteryl hemisccinate. AII stimulation of aldosterone secretion was preserved despite the decrease in AII binding after cholesteryl hemisuccinate treatment. These results indicate that AII binding can be dissociated from its effects on aldosteronogenesis by a reagent that alters membrane fluidity.


Subject(s)
Adrenal Cortex/drug effects , Cholesterol Esters/pharmacology , Membrane Fluidity/drug effects , Receptors, Angiotensin/drug effects , Receptors, Cell Surface/drug effects , Aldosterone/metabolism , Angiotensin II/metabolism , Animals , Calcium/metabolism , Cattle , Dose-Response Relationship, Drug , Fluorescence Polarization , Phosphatidylinositols/metabolism
16.
Eur J Pharmacol ; 74(2-3): 157-65, 1981 Sep 11.
Article in English | MEDLINE | ID: mdl-6799303

ABSTRACT

The calcium ionophore, A23187, produced a concentration-dependent increase in the release of norepinephrine from nerves in the rat vas deferens. Maximum response to A23187 (10(-6) - 10(-5) M) was delayed in onset, occurring 60-80 min after initiation of continuous superfusion with A23187. In fact. after tissue exposure to A23187 (10(-5) M) for only 5 min with subsequent superfusion in A23187-free buffer, a significant but delayed increase in norepinephrine efflux occurred. The A23187-induced increase in efflux of norepinephrine was not altered when neuronal sodium conductance was blocked with tetrodotoxin (3.1 X 10(-7) M) or when Na+, K+ -stimulated ATPase was blocked with ouabain (10(-4) M). Release of norepinephrine by A23187 was calcium-dependent since A23187-induced efflux of norepinephrine was diminished (approximately 50%), although not abolished, in calcium-free buffer. Thus, one component of A23187 action was calcium independent. A23187 caused an increased efflux of both norepinephrine formed endogenously and [3H]norepinephrine taken up into neuronal stores. However, the effects of A23187, both on rate and maximum amount of release were greater for [3H]norepinephrine than for endogenous norepinephrine. The present studies demonstrate that neurotransmitter efflux can be induced by carboxylic ionophores in a calcium-dependent process, and this approach may prove useful in studies evaluating factors that modulate neurotransmitter release processes.


Subject(s)
Anti-Bacterial Agents/pharmacology , Calcimycin/pharmacology , Norepinephrine/metabolism , Animals , Calcium/pharmacology , Dose-Response Relationship, Drug , Male , Ouabain/pharmacology , Rats , Rats, Inbred Strains , Tritium , Vas Deferens/metabolism
18.
Clin Exp Hypertens (1978) ; 2(6): 1067-82, 1980.
Article in English | MEDLINE | ID: mdl-6108842

ABSTRACT

Tiodazosin (BL5111) is a structural analogue of prazosin that is currently being evaluated for clinical efficacy in the treatment of hypertension. Like prazosin, tiodazosin was a potent competitive postsynaptic alpha adrenergic receptor antagonist. Although tiodazosin exhibited an affinity for the postsynaptic alpha receptor that was 17 times lower than prazosin, tiodazosin was still 4 times more potent than phentolamine in this regard. Under in vitro conditions, tiodazosin, like prazosin, also produced a noncompetitive antagonism of alpha adrenergic receptors in the portal vein, did not show marked affinity for presynaptic alpha adrenergic receptors, and lacked any measurable direct vasodilator effects (nonreceptor mediated) independent of alpha adrenergic receptor blockade.


Subject(s)
Adrenergic alpha-Antagonists/pharmacology , Prazosin/pharmacology , Quinazolines/pharmacology , Animals , In Vitro Techniques , Male , Mesenteric Arteries/drug effects , Norepinephrine/metabolism , Phentolamine/pharmacology , Portal Vein/drug effects , Prazosin/analogs & derivatives , Rats , Vas Deferens/drug effects , Vasodilation/drug effects
19.
Can J Physiol Pharmacol ; 57(11): 1246-50, 1979 Nov.
Article in English | MEDLINE | ID: mdl-519528

ABSTRACT

The observation that the rat jugular vein relaxed in response to norepinephrine but not to field stimulation prompted us to evaluate the extent of innervation in this tissue. The norepinephrine concentration in the jugular vein was about 10% of that in the mesenteric artery and vein. The low levels of norepinephrine were not due to higher monoamine oxidase activity relative to the enzyme activity in other blood vessels. In the jugular vein, as in heart and brain, serotonin was preferred substrate for monoamine oxidase whereas in the femoral vein, mesenteric vein, and mesenteric artery, phenylethylamine oxidation was greater. Based on kinetic and inhibitory studies with LY51641, a selective type A inhibitor, monoamine oxidase activity was not found to be uniform throughout the cardiovascular system. In addition to low levels of norepinephrine, acetylcholinesterase activity in the jugular vein was only 5 and 13% of the activity in the portal vein and mesenteric artery, respectively. Thus, we provide strong evidence that our inability to generate a response to field stimulation in the rat jugular vein results from the lack of functional innervation in this tissue. This information adds to the usefulness of this preparation for comparative studies of agents acting on the smooth muscle without the added complication of neuronal uptake mechanisms.


Subject(s)
Acetylcholinesterase/analysis , Jugular Veins/analysis , Monoamine Oxidase/analysis , Norepinephrine/analysis , Animals , Blood Vessels/analysis , Brain/enzymology , Jugular Veins/innervation , Male , Myocardium/enzymology , Rats
SELECTION OF CITATIONS
SEARCH DETAIL
...