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2.
Ophthalmologe ; 109(2): 149-54, 2012 Feb.
Article in German | MEDLINE | ID: mdl-22130726

ABSTRACT

Punctate inner choroidopathy (PIC) is a rare disease which seems to have an inflammatory origin. Treatment is symptom-oriented and the development of choroidal neovascularization (CNV). If CNV is present the trend is towards the use of anti-VEGF (vascular endothelial growth factor) therapy. Oral therapy with steroids should be initially attempted.


Subject(s)
Angiogenesis Inhibitors/administration & dosage , Photochemotherapy/methods , Photosensitizing Agents/administration & dosage , Vascular Endothelial Growth Factor A/antagonists & inhibitors , Adolescent , Choroid Diseases , Drug Therapy, Combination/methods , Female , Humans , Treatment Outcome
3.
Klin Monbl Augenheilkd ; 225(2): 169-72, 2008 Feb.
Article in German | MEDLINE | ID: mdl-18293271

ABSTRACT

In both cases optic disc neuropathy with perimetry defects and loss of vision is caused by a cerebral tumour. The progression of optic damage was stopped by resection of the tumor in both patients. We recommend the performance of a radiological examination in patients with visual field defects if the intraocular pressure is normal and thus glaucoma may not be the cause of the defects.


Subject(s)
Adenoma, Chromophobe/diagnosis , Glaucoma/diagnosis , Meningeal Neoplasms/diagnosis , Meningioma/diagnosis , Optic Nerve Diseases/diagnosis , Pituitary Neoplasms/diagnosis , Vision Disorders/diagnosis , Visual Fields , Adenoma, Chromophobe/surgery , Aged , Diagnosis, Differential , Female , Humans , Magnetic Resonance Imaging , Male , Meningeal Neoplasms/surgery , Meningioma/surgery , Middle Aged , Nerve Compression Syndromes/diagnosis , Nerve Compression Syndromes/surgery , Optic Nerve Diseases/etiology , Pituitary Neoplasms/surgery , Vision Disorders/etiology , Visual Acuity
4.
Klin Monbl Augenheilkd ; 223(11): 899-903, 2006 Nov.
Article in German | MEDLINE | ID: mdl-17131250

ABSTRACT

BACKGROUND: The aim of this study was to compare the results of intraocular pressure (IOP) measurements obtained using the pressure phosphene tonometer Proview with those from Goldmann applanation tonometer (GAT) in normal and glaucomatous eyes. PATIENTS AND METHODS: The IOP in 150 eyes of 62 healthy volunteers and 88 patients with glaucoma or ocular hypertension was measured prospectively in a sitting position. After being trained to use the Proview device, Goldmann applanation tonometry was performed first. Then the patient took a reading with the Proview self-tonometer. RESULTS: For all investigated eyes the measurements with the Proview were on average 5.5 mmHg higher than those by GAT. Only 34 % of the readings from the two devices were within a difference range of +/- 3 mmHg. On comparing the group of glaucomatous patients with slight visual field defects with the group of healthy subjects and patients with ocular hypertension without visual field defects we determined almost the same mean difference between the Proview and GAT (mean difference in the group with visual field defects = 4.7 +/- 4.1 mmHg; without defects = 4.8 +/- 2.9 mmHg). CONCLUSIONS: The tonometer Proview did not show a close agreement to GAT. Therefore, the PPT does not offer an alternative method for measuring IOP. We do not recommend the Proview for self-tonometry at home or for clinical management of patients with glaucoma. Slight visual field defects seem to have no influence on intraocular pressure measurement with the self-tonometer.


Subject(s)
Glaucoma/diagnosis , Glaucoma/physiopathology , Intraocular Pressure , Self Care/instrumentation , Tonometry, Ocular/instrumentation , Tonometry, Ocular/methods , Adolescent , Adult , Aged , Equipment Design , Equipment Failure Analysis , Female , Humans , Male , Middle Aged , Reproducibility of Results , Self Care/methods , Sensitivity and Specificity
5.
Ophthalmologe ; 103(3): 221-3, 2006 Mar.
Article in German | MEDLINE | ID: mdl-15995843

ABSTRACT

We report the case of a patient who experienced recurrent elevations of intraocular pressure during haemodialysis. We measured a rise in intraocular pressure of 10-12 mmHg after dialysis. The lens showed intumescence, and a ciliary block was detected by means of Orbscan II. Within 6 h findings had normalized. Changes in serum osmolarity due to haemodialysis may result in fluid shifts between different compartments. Decrease of serum osmolarity during dialysis may lead to lens swelling and thus cause a ciliary block. This may end with regression of the lens swelling.


Subject(s)
Ciliary Body/pathology , Glaucoma/diagnosis , Glaucoma/etiology , Ocular Hypertension/diagnosis , Ocular Hypertension/etiology , Renal Dialysis/adverse effects , Aged , Humans , Male , Recurrence
6.
Microbiol Immunol ; 45(10): 699-707, 2001.
Article in English | MEDLINE | ID: mdl-11762752

ABSTRACT

In Streptococcus sanguinis (sanguis) induced experimental endocarditis, we sought evidence that the development of aortic valvular vegetation depends on the availability of fibrin. Endocarditis was induced in New Zealand white rabbits by catheter placement into the left ventricle and inoculation of the bacteria. Fibrin was localized in the developing vegetation with 99mTechnetium (Tc)-labeled anti-fibrin antibody one or three days later. When rabbit anti-fibrin antibody was given intravenously on day 1, the mass of aortic valvular vegetation was significantly reduced at day 3; infusion of non-specific rabbit IgG showed no effect. The 99mTc-labeled anti-fibrin antibody also labeled kidneys that showed macroscopic subcapsular hemorrhage. To learn if the deposition of fibrin in the kidneys was a consequence of endocarditis required a comparison of farm-bred and specific pathogen-free rabbits before and after the induction of endocarditis. Before induction, the kidneys of farm-bred rabbits were labeled, but specific pathogen-free rabbits were free of labeling and signs of macroscopic hemorrhage. After 3 days of endocarditis, kidneys of 10 of 14 specific pathogen-free rabbits labeled with 99mTc-labeled anti-fibrin antibody and showed hemorrhage. Kidney lesions were suggested to be a frequent sequellae of S. sanguinis infective endocarditis. For the first time, fibrin was shown to be required for the continued development of aortic valvular vegetations.


Subject(s)
Antibodies/immunology , Aortic Valve/immunology , Endocarditis, Bacterial/immunology , Fibrin/immunology , Kidney/immunology , Streptococcal Infections/immunology , Streptococcus sanguis/pathogenicity , Animals , Aortic Valve/microbiology , Disease Models, Animal , Endocarditis, Bacterial/microbiology , Endocarditis, Bacterial/physiopathology , Kidney/microbiology , Rabbits , Streptococcal Infections/microbiology , Streptococcal Infections/physiopathology , Technetium/metabolism
7.
Plasmid ; 42(1): 67-72, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10413668

ABSTRACT

To study streptococcal genes that are specifically induced in the host during endocarditis, we have developed a novel plasmid for use in in vivo expression technology (IVET). This IVET uses an integration plasmid, pAK36, that carries dual (amy-cat) reporter genes. A gene-fusion strain library was constructed with the plasmid randomly inserted into the chromosome of Streptococcus gordonii V288 by insertion-duplication. The library was inoculated intravenously into a rabbit that had been prepared for experimental endocarditis. Beginning 6 h after the inoculation, the rabbit was given chloramphenicol (Cm) intravenously twice a day to a final serum level of 5 microg/ml and was euthanized 3 days later. The aortic valve vegetations containing Cm(R) S. gordonii clones were cultured. Colonies were screened in vitro for negative amylase activity and sensitivity to Cm. Forty-eight such colonies showed 13 different insertion patterns when Southern hybridization blots were probed with labeled pAK36. For each of the 13 isolates, the gene fragment proximal to the insertion of the reporter amy-cat was cloned, and its nucleotide sequence was determined. Functions of these genes were inferred by their homology to known genes. Therefore, this novel IVET vector can be useful for identification of in vivo induced genes in S. gordonii and other streptococcal species.


Subject(s)
Genes, Bacterial , Genetic Vectors , Plasmids/genetics , Streptococcus/genetics , Animals , Artificial Gene Fusion , Chloramphenicol Resistance/genetics , Disease Models, Animal , Endocarditis, Bacterial/microbiology , Gene Expression , Genes, Reporter , Rabbits , Streptococcal Infections/microbiology , Streptococcus/drug effects , Streptococcus/pathogenicity , Virulence/genetics
8.
Infect Immun ; 66(12): 5906-14, 1998 Dec.
Article in English | MEDLINE | ID: mdl-9826372

ABSTRACT

By mimicking hemostatic structural domains of collagen, Streptococcus sanguis (aggregation-positive phenotype; Agg+) induces platelets to aggregate in vitro. To test the hypothesis that aggregation occurs in vivo, S. sanguis (Agg+ or Agg- suspension) was infused intravenously into rabbits. The extent of hemodynamic and cardiopulmonary changes and the fate of circulating platelets were Agg+ strain dose dependent. Within 45 to 50 s of the start of infusion, 40 x 10(8) CFU of the Agg+ strain caused increased blood pressure. Thirty seconds after infusion, other changes occurred. Intermittent electrocardiographic abnormalities (13 of 15 rabbits), ST-segment depression (10 of 15 rabbits), and preventricular contractions (7 of 15 rabbits) manifested at 3 to 7 min, with frequencies dose dependent. Respiratory rate and cardiac contractility increased during this phase. Blood catecholamine concentration, thrombocytopenia, accumulation of 111Indium-labeled platelets in the lungs, and ventricular axis deviation also showed dose dependency. Rabbits were unaffected by inoculation of an Agg- strain. Therefore, Agg+ S. sanguis induced platelet aggregation in vitro. Platelet clots caused hemodynamic changes, acute pulmonary hypertension, and cardiac abnormalities, including ischemia.


Subject(s)
Bacteremia/physiopathology , Cardiovascular Physiological Phenomena , Platelet Aggregation , Respiration , Streptococcal Infections/physiopathology , Streptococcus sanguis/pathogenicity , Animals , Electrocardiography , Female , Hemodynamics , Infusions, Intravenous , Male , Myocardial Contraction , Rabbits
9.
J Psychol ; 131(4): 407-10, 1997 Jul.
Article in English | MEDLINE | ID: mdl-9190057

ABSTRACT

In a class on the psychology of male roles, 38 undergraduates (18 men, 20 women) participated in an activity designed to assess gender stereotypes. A chi-square analysis revealed that participants produced significantly more negative stereotypes for men than for women. These results, consistent with crosscultural findings, are discussed in terms of methodological issues and the differential socialization of men and women.


Subject(s)
Men , Prejudice , Stereotyping , California , Chi-Square Distribution , Female , Humans , Male
10.
Adv Dent Res ; 11(1): 69-74, 1997 Apr.
Article in English | MEDLINE | ID: mdl-9524444

ABSTRACT

To identify streptococcal genes that are expressed during experimental endocarditis, we developed a promoter-less dual reporter gene-fusion (amy, cat) plasmid, pAK36. Chromosomal DNA from S. gordonii V288 was digested with Sau3A1. The resulting fragments were ligated into pAK36. Following transformation into S. gordonii, the library of random gene fusion clones was inoculated into a rabbit to induce experimental endocarditis. Chloramphenicol treatment effected positive selection. Upon euthanization of the rabbits, the valvular vegetations were excised in a sterile field. Surviving clones were isolated and screened in vitro for chloramphenicol sensitivity and negative amylase activity. From the 48 randomly picked, double-negative clones, DNA was isolated and analyzed by Southern hybridization with labeled pAK36 probe. Different insertion patterns were identified, suggesting that no fewer than 13 S. gordonii genes were induced. Therefore, S. gordonii genes are induced during experimental endocarditis, which may contribute to virulence.


Subject(s)
Endocarditis, Bacterial/microbiology , Streptococcus/genetics , Streptococcus/pathogenicity , Animals , DNA, Bacterial/analysis , Ecosystem , Gene Expression Regulation, Bacterial , Genes, Bacterial/genetics , Heart Valves/microbiology , Klebsiella pneumoniae/genetics , Platelet Aggregation/physiology , Rabbits , Sequence Homology , Streptococcus sanguis/genetics , Streptococcus sanguis/pathogenicity , Virulence/genetics
11.
Physiol Zool ; 70(1): 19-26, 1997.
Article in English | MEDLINE | ID: mdl-9231372

ABSTRACT

We validated the doubly labeled water (DLW) technique for measurement of energy expenditure in bald eagles (Haliaeetus leucocephalus) in captivity by simultaneously measuring metabolizable energy intake in a feeding trial. We calculated CO2 production using two equations, one typically used by animal ecologists (the "one-pool" equation) and the other typically used by human nutritionists (the "two-pool" equation). Metabolizable energy intake, as determined by feeding trials, for two adult eagles eating rats averaged 1,160 +/- 89 kJ d-1 and for four nestlings eating fish averaged 2,124 +/- 40 kJ d-1. Energy expenditure measured from DLW turnover using the one-pool equation averaged 2.2% +/- 7.1% higher than metabolizable energy intake measured by feeding trials (not significantly different, P > 0.50), but when the two-pool equation was used, energy expenditure measured with DLW averaged 17.7% +/- 6.7% lower than metabolizable energy intake measured by feeding trials (significantly different, 0.025 < P < 0.05). Thus, the use of the DLW technique with CO2 production calculated by the one-pool equation was validated for bald eagles.


Subject(s)
Birds/metabolism , Carbon Dioxide/metabolism , Energy Metabolism/physiology , Animals , Birds/physiology , Body Mass Index , Carbon Isotopes , Deuterium , Eating/physiology , Female , Male , Methods , Oxygen Isotopes , Reproducibility of Results
12.
J Periodontol ; 67(10 Suppl): 1138-42, 1996 Oct.
Article in English | MEDLINE | ID: mdl-8910832

ABSTRACT

During episodes of dental bacteremia, viridans group streptococci encounter platelets. Among these microorganisms, certain Streptococcus sanguis induce human and rabbit platelets to aggregate in vitro. In experimental rabbits, circulating streptococci induced platelets to aggregate, triggering the accumulation of platelets and fibrin into the heart valve vegetations of endocarditis. At necropsy, affected rabbit hearts showed ischemic areas. We therefore hypothesized that circulating S. sanguis might cause coronary thrombosis and signs of myocardial infarction (MI). Signs of MI were monitored in rabbits after infusion with platelet-aggregating doses of 4 to 40 x 10(9) cells of S. sanguis 133-79. Infusion resulted in dose-dependent changes in electrocardiograms, blood pressure, heart rate, and cardiac contractility. These changes were consistent with the occurrence of MI. Platelets isolated from hyperlipidemic rabbits showed an accelerated in vitro aggregation response to strain 133-79. Cultured from immunosuppressed children with septic shock and signs of disseminated intravascular coagulation, more than 60% of isolates of viridans streptococci induced platelet aggregation when tested in vitro. The data are consistent with a thrombogenic role for S. sanguis in human disease, contributing to the development of the vegetative lesion in infective endocarditis and a thrombotic mechanism to explain the additional contributed risk of periodontitis to MI.


Subject(s)
Bacterial Physiological Phenomena , Blood Platelets/physiology , Heart Diseases/etiology , Mouth/microbiology , Animals , Bacteremia/microbiology , Blood Pressure , Cells, Cultured , Child , Coronary Thrombosis/etiology , Coronary Thrombosis/microbiology , Disseminated Intravascular Coagulation/blood , Disseminated Intravascular Coagulation/physiopathology , Electrocardiography , Endocarditis, Bacterial/etiology , Endocarditis, Bacterial/microbiology , Fibrin/physiology , Heart Diseases/microbiology , Heart Rate , Humans , Hyperlipidemias/blood , Hyperlipidemias/physiopathology , Immunocompromised Host , Myocardial Contraction , Myocardial Infarction/etiology , Myocardial Infarction/microbiology , Myocardial Ischemia/etiology , Myocardial Ischemia/microbiology , Periodontitis/microbiology , Platelet Aggregation , Rabbits , Shock, Septic/blood , Shock, Septic/physiopathology , Streptococcus sanguis/physiology , Thrombosis/blood , Thrombosis/physiopathology
13.
Arch Environ Contam Toxicol ; 31(2): 225-31, 1996 Aug.
Article in English | MEDLINE | ID: mdl-8781073

ABSTRACT

We compared the seasonal concentrations of 12 organochlorine (OC) compounds in samples of breast muscle, associated skin, and subcutaneous fat of blue-winged teal (Anas discors) collected in Ciénaga Grande de Santa Marta, Colombia (1987-1988), and of mallards (Anas platyrhynchos) and blue-winged teal collected in Wisconsin (1984-1989). Although these species have similar feeding habits and overlapping breeding distributions, their winter ranges differ markedly. Most blue-winged teal winter in the Neotropics, whereas most mallards remain in the temperate regions of North America. A seasonal comparison of OC exposure in these species may help determine the geographic origins of contamination. All examined OCs were found to be below concentrations known to affect reproduction in waterfowl. DDE was most often detected in blue-winged teal and PCBs, in mallards. DDE exposure may have predominantly occurred outside of Wisconsin. The DDE concentration in blue-winged teal samples collected in Wisconsin in the spring (GM=0.406 microg/g) were greater (P<0.001) than in the fall (GM=0. 033 microg/g) and greater than the concentrations in mallard samples from the spring (GM=0.058 microg/g; P<0.001). Ciénaga Grande, however, was not a source of DDE contamination. The DDE concentrations in blue-winged teal samples from Ciénaga Grande did not differ between the spring (GM=0.037 microg/g) and the fall (GM=0. 039 microg/g) and were lower (P<0.001) than the concentration in blue-winged teal samples from Wisconsin in the spring. In contrast, PCB contamination seemed to have occurred in Wisconsin and affected mostly mallards. PCBs were not detected in the samples from Colombia and were detected in only five (8.3%) of the blue-winged teal samples from Wisconsin (GM=0.025 microg/g), however, those compounds were detected in 47% of the mallard samples collected in Wisconsin (GM=0.272 microg/g). DDE and PCB concentrations were greater (P=0.0) in mallard samples collected from wetlands adjacent to Lake Michigan than in samples from inland wetlands.


Subject(s)
Ducks/metabolism , Hydrocarbons, Chlorinated , Insecticides/pharmacokinetics , Pesticide Residues/pharmacokinetics , Adipose Tissue/metabolism , Animals , Colombia , Longitudinal Studies , Muscles/metabolism , Pesticide Residues/analysis , Skin/metabolism , Species Specificity , Tissue Distribution , Wisconsin
14.
Thromb Haemost ; 73(4): 680-2, 1995 Apr.
Article in English | MEDLINE | ID: mdl-7495078

ABSTRACT

In infective endocarditis vegetations are stabilized by fibrin. To learn if fibrin digestion would be therapeutic, experimental endocarditis was induced in rabbits by inoculation with a platelet-aggregating strain (Agg+) of Streptococcus sanguis and treated with recombinant tissue plasminogen activator (rt-PA), rt-PA with penicillin, or penicillin alone. Control rabbits were inoculated with saline. All treatments of Agg+ endocarditis reduced the mass of valvular vegetations and clinical signs of endocarditis, including the frequency of left axis deviation and heart ischemia. rt-PA with penicillin was more effective than penicillin or rt-PA alone, reducing the mass of vegetations and clinical signs to that of saline controls. Within 50 min, rt-PA cleared 5-fold more 111Indium-labelled platelets from the heart than untreated rabbits and 1.4-fold more after 3 days. Combined with penicillin, thrombolytic therapy for human endocarditis should be reconsidered.


Subject(s)
Endocarditis/drug therapy , Plasminogen Activators/therapeutic use , Animals , Disease Models, Animal , Drug Combinations , Endocarditis/microbiology , Humans , Penicillins/administration & dosage , Plasminogen Activators/administration & dosage , Rabbits , Recombinant Proteins/therapeutic use , Streptococcal Infections/drug therapy , Streptococcus sanguis
15.
S D J Med ; 46(12): 423-4, 1993 Dec.
Article in English | MEDLINE | ID: mdl-8303253

ABSTRACT

Orf virus infection is endemic among sheep and goats, and can occur in humans who handle these animals. Orf virus infection in humans causes a characteristic skin lesion, and systemic symptoms can occur. Very little is known about Orf virus infection in human pregnancy. A case of Orf virus infection, with onset at 33 weeks gestation, is presented. There were no pathological findings in the infant born at term, or in the placenta.


Subject(s)
Ecthyma, Contagious/epidemiology , Orf virus , Pregnancy Complications, Infectious/microbiology , Adult , Animals , Ecthyma, Contagious/transmission , Female , Humans , Pregnancy , Sheep , South Dakota/epidemiology
17.
J Chem Ecol ; 19(7): 1577-85, 1993 Jul.
Article in English | MEDLINE | ID: mdl-24249184

ABSTRACT

The hypothesis was tested that the reproductive performance of voles would be reduced when fed diets containing tannins either because of increased metabolic rates, decreased intake, or decreased digestive efficiency. We fed a ration containing 4% tannic acid (TA) (dry mass basis) to 24 pair of prairie voles (Microtus ochrogaster) and compared reproductive performance (litter size, birth weights, body mass of the young until weaning, and mass changes in the dams) to that of 24 pair of prairie vole fed a control ration. We also compared the intake rates, digestive efficiency, and metabolic rates [as measured by Vo2 consumption (cm(3)/hr)] of dams and young fed both rations. Voles consuming 4% TA diets produced litters of similar size and mass as did voles fed the control ration. Furthermore, the mass of the young of dams fed the tannic acid ration were similar to the young of dams consuming the control ration through day 19 postpartum. However, dams consuming the tannic acid ration lost mass throughout lactation while the control dams maintained mass. Because the Vo2 rates of both treated and control dams and litters were similar, we conclude increased metabolic costs were not the reason for the observed mass loss but, rather, reduced digestive efficiency, reduced intake of digestible dry mass, and apparent digestible nitrogen.

18.
Infect Immun ; 60(11): 4809-18, 1992 Nov.
Article in English | MEDLINE | ID: mdl-1398992

ABSTRACT

A strain of Streptococcus sanguis that induced rabbit platelets to aggregate in vitro (Agg+ phenotype) was hypothesized to be a more virulent pathogen than an Agg- strain in experimental endocarditis in rabbits. A left ventricular catheter was implanted, and then an Agg+ or Agg- strain was inoculated intravenously. Vegetations formed on the aortic semilunar valves but were unaffected by the duration of implantation of the catheter. Vegetations enlarged by accumulating platelets and their mass increased directly with the duration of endocarditis. Inoculation of the Agg+ strain consistently caused endocarditis with significantly larger vegetations, a more severe clinical course (including febrile episodes, hematological changes, and signs of myocardial ischemia), more gross lesions in major organs, and greater mortality than inoculation with the Agg- strain, saline, or the Agg+ strain pretreated with monospecific rabbit immunoglobulin G or Fab fragments against its platelet aggregation-associated protein (PAAP; class II). In experimental endocarditis, PAAP expressed by Agg+ S. sanguis appeared to be an important virulence factor.


Subject(s)
Blood Platelets/immunology , Endocarditis, Bacterial/microbiology , Streptococcus sanguis/pathogenicity , Animals , Endocarditis, Bacterial/diagnostic imaging , Endocarditis, Bacterial/pathology , Heart Valves/microbiology , In Vitro Techniques , Platelet Aggregation , Rabbits , Radionuclide Imaging , Time Factors
19.
Zentralbl Pathol ; 138(1): 61-5, 1992.
Article in German | MEDLINE | ID: mdl-1596487

ABSTRACT

Marked lipid deposits selectively localized in the grooves of so-called aortic functional structures were found in a 5-month-old infant who died of rapidly progressing crescentic glomerulonephritis. A prominent nephrotic syndrome comprising hypercholesterolemia and triglyceridemia was present and led to extensive lipid infiltration of the aortic intima. Development of the intimal lesions was probably enhanced by hypertension found in final phase of the illness. Spontaneously enhanced permeability of the intima in the "grooves" and a special constellation of haemodynamic forces along the functional structures were probably responsible for the peculiarly selective localization of lipid deposits that has so far not been described in the literature.


Subject(s)
Aorta, Abdominal/pathology , Arteriosclerosis/pathology , Arteriosclerosis/etiology , Glomerulonephritis/pathology , Humans , Hypercholesterolemia/complications , Hypercholesterolemia/pathology , Hypertriglyceridemia/complications , Hypertriglyceridemia/pathology , Infant , Kidney/pathology , Male , Nephrotic Syndrome/complications , Nephrotic Syndrome/pathology
20.
J Chem Ecol ; 18(5): 719-36, 1992 May.
Article in English | MEDLINE | ID: mdl-24253966

ABSTRACT

The acute effects of tannin (tannic acid; TA) on nutrient absorption were studied by measuring sugar and amino acid uptake across the brash border (luminal membrane) of intact intestine in the presence and absence of TA. Incubation of tissue for 4-9 min in TA solution (1 mg/ml) caused a reduction in passive influx ofL-glucose in voles and mice and a reduction in carrier-mediated influx ofD-glucose and total influx ofL-proline in mice, but not voles. In subchronic experiments, mice and voles were fed for 7-14 days a diet with 4% TA, but there was no significant effect on intestinal brush border uptake ofL-glucose,D-glucose, orL-proline (or three other amino acids tested in voles). In a synthesis of our study with others in the literature, three inferences are made from the patterns of effects across solutes, time scales of exposure, and species. First, the transport inhibitory effects following acute exposure are probably mediated by two processes: increased resistance to passive flux across an effective unstirred layer juxtaposed to the brush border membrane, perhaps due to tannin-mucin binding, and reduced Na(+)-coupled nutrient uptake across the intestinal brush border. Second, there is a species sensitivity difference in TA's effect on the second process. Third, the negative effects observed at the acute time scale in vitro do not necessarily occur in animals eating TA subchronically because little TA reaches the luminal membrane, or if it does its effects are quickly reversed when the tissue is removed and washed with solution free of TA.

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