Effect of Aspirin on the Intestinal Response to a Necrotic Enteritis Challenge.

The effect of aspirin on intestinal lesions was evaluated in birds undergoing an experimental challenge with Clostridium perfringens as part of a model for inducing subclinical necrotic enteritis (SNE). Broilers were raised on clean wood shavings and randomly assigned to three treatments: Uninfected (U), Infected (I), and Infected + Aspirin (I+A; 0.025% acetylsalicylic acid in drinking water during days 21-25). Birds in the I and I+A groups were gavaged with Eimeria maxima on day 18 and their feed was inoculated with C. perfringens (1 × 109 CFU/bird) during days 23-25. On day 26, birds were euthanatized, intestinal lesions were evaluated, and intestinal tissue was collected for qPCR assessment of genes thought to be involved in the immune response to SNE: IL-1ß, IL-10, MMP-2, and MMP-7. Birds in the I+A group had more-severe and numerous lesions compared to the I group. For all genes except MMP-2, expression was upregulated in the I group compared to the U group, but did not differ between the I and I+A groups. These results indicate that aspirin exacerbated the intestinal lesions associated with this disease. Aspirin could play a role in the development of a reliable and consistent model for the induction of necrotic enteritis under experimental settings.

Efecto de la aspirina en la respuesta intestinal a un desafío por enteritis necrótica. El efecto de la aspirina en las lesiones intestinales se evaluó en aves sometidas a un desafío experimental con Clostridium perfringens como parte de un modelo para inducir enteritis necrótica subclínica (SNE). Los pollos de engorde se criaron sobre viruta de madera limpia y se asignaron aleatoriamente a tres tratamientos: no infectado (U), infectado (I) e infectado + aspirina (I+A; ácido acetilsalicílico al 0.025% en el agua potable durante los días 21-25). A las aves de los grupos I e I+A se les administró por sonda gástrica Eimeria maxima en el día 18 y el alimento fue inoculado con C. perfringens (1×109 unidades formadoras de colonias/ ave) durante los días 23-25. En el día 26, las aves fueron sacrificadas, se evaluaron las lesiones intestinales y se recolectó tejido intestinal para la evaluación cuantitativa por PCR en tiempo real de los genes que se cree están involucrados en la respuesta inmune a la enteritis necrótica subclínica: IL-1ß, IL-10, MMP-2, y MMP-7. Las aves del grupo I+A tuvieron lesiones más graves y numerosas en comparación con el grupo I. Para todos los genes, excepto MMP-2, la expresión se regulaba positivamente en el grupo I en comparación con el grupo U pero no difería entre los grupos I e I+A. Estos resultados indican que la aspirina exacerbó las lesiones intestinales asociadas con esta enfermedad. La aspirina podría desempeñar un papel en el desarrollo de un modelo confiable y consistente para la inducción de enteritis necrótica bajo condiciones experimentales.

Periodontal pathogens and gestational diabetes mellitus.

In previous cross-sectional or case-control studies, clinical periodontal disease has been associated with gestational diabetes mellitus. To test the hypothesis that, in comparison with women who do not develop gestational diabetes mellitus, those who do develop it will have had a greater exposure to clinical and other periodontal parameters, we measured clinical, bacteriological (in plaque and cervico-vaginal samples), immunological, and inflammatory mediator parameters 7 weeks before the diagnosis of gestational diabetes mellitus in 265 predominantly Hispanic (83%) women in New York. Twenty-two cases of gestational diabetes mellitus emerged from the cohort (8.3%). When the cases were compared with healthy control individuals, higher pre-pregnancy body mass index (p=0.004), vaginal levels of Tannerella forsythia (p=0.01), serum C-reactive protein (p=0.01), and prior gestational diabetes mellitus (p=0.006) emerged as risk factors, even though the clinical periodontal disease failed to reach statistical significance (50% in those with gestational diabetes mellitus vs. 37.3% in the healthy group; p=0.38).

Intra-abdominal hypertension and the abdominal compartment syndrome.

BACKGROUND: Abdominal compartment syndrome (ACS) occurs when intra-abdominal pressure is abnormally high in association with organ dysfunction. It tends to have a poor outcome, even when treated promptly by abdominal decompression. METHODS: A search of the Medline database was performed to identify articles related to intra-abdominal hypertension and ACS. RESULTS: Currently there is no agreed definition or management of ACS. However, it is suggested that intra-abdominal pressure should be measured in patients at risk, with values above 20 mmHg being considered abnormal in most. Abdominal decompression should be considered in patients with rising pressure and organ dysfunction, indicated by increased airway pressure, reduced cardiac output and oliguria. Organ dysfunction often occurs at an intra-abdominal pressure greater than 35 mmHg and may start to develop between 26 and 35 mmHg. The mean survival rate of patients affected by compartment syndrome is 53 per cent. CONCLUSION: The optimal time for intervention is not known, but outcome is often poor, even after decompression. Most of the available information relates to victims of trauma rather than general surgical patients.

Selective inhibition of the renal angiotensin type 2 receptor increases blood pressure in conscious rats.

The angiotensin II type 2 (AT(2)) receptor is present in rat kidney; however, its function is not well understood. The purpose of this study was to evaluate the role of the AT(2) receptor in blood pressure (BP) regulation. The effects of selective inhibition of the renal AT(2) receptor with phosphorothioated antisense oligodeoxynucleotide (AS-ODN) were examined in conscious uninephrectomized rats. Oligodeoxynucleotides (AS-ODN or scrambled [S-ODN]) were infused directly into the renal interstitial space by using an osmotic pump at 1 microL/h for 7 days. Texas red-labeled AS-ODN was distributed in renal tubules in the infused but not the contralateral kidney of normal rats. Continuous renal interstitial infusion of the AS-ODN, but not S-ODN, caused a significant (P<0.01) increase in BP 1 to 5 days after the initiation of the infusion. AS-ODN-treated rats experienced an increase in systolic BP from 109+/-4 to 130+/-4 mm Hg (n=8, P<0.01), whereas S-ODN-treated (n=8) and vehicle-treated (n=8) rats did not show any significant change in BP. On day 5 of the oligodeoxynucleotide infusion, AS-ODN-treated rats exhibited a greater pressor response to systemic angiotensin II infusion (30 ng/kg per hour) than did S-ODN-treated rats (P<0.01). Renal interstitial fluid cGMP decreased from 11.9+/-0.8 to 3.6+/-0.5 pmol/mL (P<0.001), and bradykinin decreased from 0.05+/-0.05 to 0.18+/-0.03 ng/mL (P<0.001) in response to AS-ODN, but they were not significantly changed in response to S-ODN. To evaluate the effects of AS-ODN and S-ODN on AT(2) receptor expression, Western Blot analysis was performed on treated kidneys. Kidneys treated with AS-ODN had approximately 40% less expression of AT(2) receptor than did kidneys treated with S-ODN or vehicle (P<0.05). These results suggest that AS-ODN directed selectively against the renal AT(2) receptor decreased receptor expression and caused an increase in BP. We conclude that the renal AT(2) receptor plays an important role in the regulation of BP via a bradykinin/cGMP vasodilator signaling cascade.

Expression and localization of angiotensin subtype receptor proteins in the hypertensive rat heart.

The cellular localization of the AT(2) receptor and the regulation of its expression in hypertrophied left ventricle are not well known. We compared the expression of the cardiac AT(1) and AT(2) receptor in spontaneously hypertensive rats/Izumo strain (SHR/Izm) and Wistar Kyoto rats/Izumo strain (WKY/Izm), ages 4, 12, and 20 wk, by means of immunohistochemistry and Western blot analysis. In SHR/Izm, compared with WKY/Izm, blood pressure (161 +/- 2 vs. 120 +/- 2 mmHg at 12 wk, P

Immunolocalization of subtype 2 angiotensin II (AT2) receptor protein in rat heart.

Angiotensin II exerts its effects on cardiovascular function and water and sodium homeostasis by interacting with plasma membrane receptors on target organs. The existence of subtype 2 angiotensin II (AT2) receptors in the rat heart has been demonstrated by ligand binding and reverse transcription-polymerase chain reaction. In the present study, the expression and localization of AT2 receptor protein in the rat heart was investigated using an antipeptide polyclonal antibody against the native rat AT2 receptor by light microscopic immunocytochemistry and Western blot analysis. In frozen tissue sections, positive immunostaining was observed in the myocardium and coronary vessels throughout the ventricle and atrium of neonatal and young rat hearts. Coronary vessels of the neonatal heart were more intensely stained compared with the surrounding myocardium. Positive immunoreactivity in the coronary vessels of young rats was localized to vascular endothelium but not in the smooth muscle cells. Preadsorption controls were all negative. Western blot analysis showed that the AT2 receptor protein (approximately 44 kDa) was detectable from the AT2 receptor-transfected COS-7 cells and neonatal rat cardiac myocytes but not from fibroblasts or young rat aortic smooth muscle cells. The neonatal rat heart expressed significantly more AT2 receptors than young rat heart. These data provide the first direct evidence for the expression and localization of AT2 receptor protein in the rat heart.

Expression of the subtype 2 angiotensin (AT2) receptor protein in rat kidney.

In situ hybridization studies have suggested that the subtype 2 angiotensin (AT2) receptor gene is expressed in fetal and newborn rat kidney but is undetectable in the adult animals. In the present study, we investigated the expression of AT2 receptor protein in the fetal (days 14 and 19 of fetal life), newborn (day 1 postpartum), and adult (4-week-old and 3-month-old) rat kidney. Polyclonal anti-peptide antiserum was raised against the amino terminus of the native AT2 receptor. The selectivity of the antiserum was validated by recognition of the AT2 receptor in a stably transfected COS-7 cell line by Western blot and immunocytochemical analysis. As a positive control, the AT2 receptor signal was detected strongly in the adrenal gland. Positive immunohistochemical staining was observed in the mesenchymal cells and ureteric buds of the 14-day fetal kidney and in the glomeruli, tubules, and vessels in the 19-day fetal and newborn kidney. Glomeruli expressing the AT2 receptor were localized mainly in the outer layer of the renal cortex. In the young (4-week-old) and mature (3-month-old) adult rat on normal sodium intake, renal AT2 receptor immunoreactivity was present in glomeruli but substantially diminished compared with that of newborn rats. In both young and mature adult rats, dietary sodium depletion increased the renal AT2 receptor signal, mainly in the glomeruli and interstitial cells. Preimmune and preadsorption controls were negative. Western blot analysis detected a single 44-kD band in the fetal and newborn rat kidney and in the young and mature adult rat kidney. Dietary sodium depletion increased the density of the AT2 receptor band in mature adult rat kidneys. These data provide evidence that the AT2 receptor protein is expressed in the fetal and newborn rat kidney, diminishes in adult life, and is reexpressed in the adult in response to sodium depletion.

Localization of the dopamine D1 receptor protein in the human heart and kidney.

The dopamine D1 receptor has recently been identified in the rat heart and kidney. In the present study, using Western blot analysis and light microscopic immunohistochemistry, we examined D1 receptor protein expression in the human kidney and heart. Antipeptide polyclonal rabbit antiserum was raised against the third extracellular domain of the native receptor and affinity-purified using a protein-A column. Selectivity of the antiserum was validated by recognition of the D1 receptor expressed in stably transfected LTK- cells and Sf-9 cells. The immunohistochemical staining for D1 receptor protein was distributed throughout the atrium and ventricular myocardium and in the coronary vessels. In the kidney, positive immunoreactive signal was detected in the proximal and distal tubules, the collecting ducts, and the large intrarenal vasculature, whereas staining was absent in the juxtaglomerular (JG) cells and the glomeruli. D1 receptor antiserum preadsorbed against the immunizing peptide did not produce significant staining. In Western blot analysis, a single 55-kD band was detected for the D1 receptor in membranes from the D1 receptor transfected Sf-9 cells but not in nontransfected cells. In the heart and kidney, we detected a 55-kD band as well as an additional 40-kD band, which may reflect partial degradation of the receptor protein. These results provide the first evidence for the localization of the dopamine D1 receptor protein in the human heart and kidney. The similar distribution of this subtype receptor in the human heart and kidney to that in the rat supports the possible (patho)physiological significance of the peripheral dopamine system in humans.

Donor leukocyte infusions in the treatment of chronic myeloid leukemia in relapse post bone marrow transplantation.

A 25-yr-old Caucasian man presented in 1988 with Philadelphia chromosome (Ph) negative, bcr-abl rearranged, chronic phase chronic myeloid leukemia (CML). He was treated with human leukocyte antigen matched sibling allogeneic bone marrow transplantation but relapsed 5 yrs later. At this time he was given donor leukocyte infusions from the original bone marrow donor, seeking an immune anti-leukemic effect. This treatment induced graft versus host disease and severe bone marrow aplasia, requiring immunosuppression and repeat donor marrow infusion (without prior conditioning). Graft versus host disease was controlled and full donor hematopoiesis was restored, resulting in complete eradication of the leukemic clone at a molecular level. The patient remains in complete clinical and molecular remission and off all immunosuppression 24 mths later. This emphasizes a potentially powerful graft versus leukemia effect in CML.

Eastern European public health: opportunity and challenge.

Allied health professionals in the United States have a unique opportunity to help people living in countries of the former Eastern Bloc. The United States government has shown its willingness to help by including Czechoslovakia in the 1990 SEED (Support for East European Democracies) Act which gives financial support and favored treatment. The National Institutes of Health have allocated three million dollars a year for the past three years for projects in Eastern Europe. However, money and laws alone will not solve the ongoing problems in Eastern Europe. It will require people who appreciate what they have and care enough to make a difference in the world community. By educating, facilitating, and temporarily executing change, a health care tragedy can be turned around. It is an inherent violation of our oaths and ethical contracts if we turn our backs when so very little time and effort can make so great a difference.

Correlation between anti-hypertensive activity in rats and plasma angiotensin I-converting enzyme (ACE) inhibition in mice following oral administration of ACE inhibitors.

Thirty-four ACE inhibitors were evaluated to determine the concentration giving 50% inhibition of purified rabbit lung ACE (IC50 microM) using benzyloxycarboxyl-p-NO2-Phe-His-Leu as substrate, to determine the oral dose causing a lowering in blood pressure of 30 mm Hg (ED30 mumol/kg) in acute aortic coarctate (AAC) rats, and to determine inhibition of plasma ACE (PACE) activity in mice after oral dosing. Mouse PACE activity was determined with 14C-Hip-His-Leu as substrate one hour after oral dosing of 3 animals/group with 5 or 50 mumol ACE inhibitor per kg. Data from mice were expressed as percent of control group PACE activity. Least squares regression analysis showed the IC50 data to be poorly correlated with either rat data or mouse PACE data at 50 mumol/kg p.o. However, correlation was significant between log rat ED30 and mouse PACE at 5 (p less than 0.001, r = 0.570) and 50 (p less than 0.025, r = 0.387) mumol/kg p.o. Thus, the simple mouse plasma ACE determination after a dose of 5 mumol/kg is a convenient supplement to the AAC rat model for showing oral activity of ACE inhibitors.

Acute postural change--a novel approach to blood pressure tracking in children.

Among 1443 children, aged 5 to 18, followed for five consecutive years, we identified 68 who tracked consistently in the lowest blood pressure (BP) quartile and 114 in the highest. BP and corresponding heart rate were taken with subjects in the supine, sitting and erect postures. BP quartiles were established for each height category. Children consistently in the highest BP quartile had greater relative weight and higher heart rates in all three positions. On assuming the erect posture, children in the lowest BP quartile showed an increase in systolic BP, while those in the highest BP quartile showed a decrease. Both groups showed an increase in diastolic BP. On assuming the erect posture, subjects in the two groups showed no difference in heart rate change; subjects in the highest BP quartile did not show the additional reflex increase in heart rate to be expected in response to the decrease in systolic blood pressure. This combination of BP and heart rate findings suggests a subtle change in the baroreceptor reflex.

Effect of nolinium bromide on vascular smooth muscle.

Nolinium bromide inhibits gastric acid secretion and gastrointestinal smooth muscle contraction. While the compound's gastric antisecretory action has been attributed in part to inhibition of gastric adenylate cyclase and the gastric proton-transport ATPase, the mechanism of nolinium bromide's relaxant effect on smooth muscle has not been elucidated. We have determined that nolinium bromide inhibits contraction of vascular smooth muscle, using isolated rabbit aortic strips. This report characterizes the specificity of this inhibition (by using several agonists) and its Ca2+ dependence (by using contractile conditions of known dependence on various Ca2+ pools). Nolinium bromide (50-200 microM) was a reversible, insurmountable inhibitor of contractions induced by Ca2+ (in 40 mM KC1 depolarizing medium) and norepinephrine, with IC50 values of 96 and 118 microM, respectively, for suppression of maximum contractile force. Contractions in response to Asn1Val5-angiotensin II in both 2.5 mM Ca2+ and 0 mM Ca2+ medium were also inhibited (IC50 value = 110 microM under both conditions). Initial contraction rates for all these conditions were depressed by nolinium bromide. Nolinium bromide inhibited equally the phasic (internal Ca2+-dependent) and tonic (external Ca2+-dependent) components of norepinephrine-induced contractions. These results extend the muscle relaxant profile of nolinium bromide to include, albeit with low potency, vascular smooth muscle, and show that its potency is similar in inhibiting the contractile response to three different stimuli: angiotensin II, Ca2+, and norepinephrine.

Nocturnal food-related hyperdipsia in the adult spontaneously hypertensive rat.

Male adult spontaneously hypertensive rats (SHR) ate the same but drank more and had a higher water to food ratio (W:F) than did Wistar-Kyoto (WKY) rats in 24-hr when they had continuous access to standard laboratory pellets and tap water. When rats ate in the day phase of a 12:12 light/dark cycle after 24-hr food deprivation, SHR rats ate and drank the same ad did WKY rats in a 60-min test. When the same rats ate at night after 24-hr food deprivation, however, SHR rats were hyperdipsic: They ate the same as did WKY rats, but SHR rats drank more and had a higher W:F. This relative hyperdipsia reflected the increased ability of ingestion of food to stimulate drinking in SHR, because when food was absent for a 60-min test at night SHR drank the same as did WKY rats. Three dipsogens which are candidate components for eating-elicited drinking in the rat, cellular dehydration, histamine and angiotensin II, elicited drinking differentially in SHR and WKY rats: SHR drank more than did WKY rats in response to (1) cellular dehydration produced by IP hypertonic saline, (2) large doses of SC histamine, and (3) SC angiotensin II. These results demonstrate that SHR exhibit a nocturnal food-related hyperdipsia which may reflect differential sensitivity to stimuli important for eating-elicited drinking such as increased osmolality and endogenous histamine or angiotensin.

Cardiovascular actions of angiotensin in the fowl (Gallus domesticus). II. Angiotensin analog agonists and antagonists.

Like angiotensin II (AII) itself, [SAR1] AII induced a biphasic blood pressure response in the conscious chicken--an initial depressor response followed by a pressor response. Angiotensin III, however, induced only a depressor response in the dose range tested. The response to angiotensin I was similar to that to AII, and appeared to be due to its conversion to AII as it was inhibited by prior infusion of the angiotensin converting enzyme inhibitor SQ 20,881. Two angiotensin analog antagonists [SAR1ALA8] AII and [SAR1ILE8] AII inhibited both components of the response to AII, but the pressor response was inhibited at lower concentrations of antagonist than was the depressor response. These findings give further support to the suggestion that the pressor and depressor component of the response to AII in the conscious chicken are mediated via different AII receptors, and indicate the possibility of selective blockade of these two components.

Cardiovascular actions of angiotensin in the fowl (Gallus domesticus). I. Analysis.

Chicken aorta, unlike the aortae of any other species tested, did not respond to angiotensin II (AII) at concentrations up to 10(-4) M. The anesthetized chicken did, however, show a blood pressure increase in response to AII, but this was apparently dependent on the sympathetic nervous system. In the conscious chicken a biphasic response to AII was seen--an initial depressor response followed by a pressor response. The depressor response was not inhibited by standard blocking agents, but was blocked by prior induction of tachyphylaxis to vasopressin. It is concluded that the depressor response to AII in the conscious chicken is due to release of vasotocin, the avian equivalent to vasopressin, and the subsequent pressor response to AII is due to activation of the sympathetic nervous system.

Specific membrane-binding of angiotensin II--the role of degradative enzymes.

The possible role of degradative enzymes was examined in the specific binding of angiotensin II (AII) to cell membranes. Red blood cell membranes did not bind AII specifically under any of the ambient conditions studied, indicating a lack of AII receptors and no role for the degradative enzymes in specific binding. Rabbit aorta smooth muscle cell membranes bound AII specifically, and this binding had similar characteristics to those previously described for this preparation. It is concluded that specific binding of AII to cell membranes does not involve degradative enzymes, and probably represents binding to the biologically active receptor.

A review of the renin-angiotensin system: historical and methodological perspectives.

It is apparent that early studies of the renin-AII system utilized measurement of blood pressure and organ bath techniques. More recent methods of electrophoresis, RIA and binding studies are continuing to add to our knowledge. Future studies will involve receptor isolation and understanding of the post-receptor mechanism of transduction of the AII response. With the recent advances in our knowledge of peptide hormone-receptor interaction, particularly new findings that peptide hormones can enter the cell, it is apparent that intracellular actions of AII will provide a new field of discovery.

The interaction of enkephalins with substance P on vascular smooth muscle.

Interactions between SP and the enkephalins have bben reported in the CNS, and the possibility of a more peripheral site of interaction has now been investigated. SP (10(-6) - 10(-4) g/ml) induced dose-related contractions of the rabbit isolated aorta, which were resistant to alpha-adrenoceptor blockade (phentolamine, 5 x 10(-6) g/ml). Neither met- nor leu-enkephalin had any intrinsic action on the aorta, but met-enkephalin at 5 x 10(-6) g/ml significantly inhibited responses to SP but not to NE. Morphine (5 x 10(-6) g/ml) potentiated responses to NE, but had no significant effect on responses to SP. It is apparent that SP and met-enkephalin act on a common receptor on vascular smooth muscle, that met-enkephalin has no intrinsic action on this receptor, and that the receptor is morphine-insensitive.