Comparative analysis of diagnostic methods and risk factors for Aelurostrongylus abstrusus infection in brazilian cats.

This study aimed to prospectively evaluate the risk factors of infection by Aelurostrongylus abstrusus in Brazilian cats with cough and/or radiographic changes, using as diagnostic tools the Baermann method (BM), polymerase chain reaction (PCR) of feces, bronchoalveolar lavage fluid (BALF), and cytology. Forty-three cats that were presented with cough or lung radiographic abnormalities compatible with bronchoalveolar disease were included in the study. After clinical evaluation, feces samples were collected to investigate lungworm parasitism through BM and PCR. BALF was performed to provide samples for cytology, bacteriology, and fungal culture. Stool PCR was considered the gold standard for diagnosis tests, and the other methods were evaluated by their agreement. PCR presented 74% (32/43) of positivity for A. abstrusus, while in the BM, 41% (18/43) were positive. BM showed sensitivity of 56.25% and specificity of 100% when compared with PCR. No larva was found in the cytological evaluation of 21 BALF samples. Lungworm is an important cause of bronchopulmonary disease in domestic cats in Brazil and should be included as a differential diagnosis when a cat is presented with cough or radiographic abnormalities. BM is a sensitive, non-invasive, and cheap technique to diagnose the disease, but it is not as sensitive as PCR.

Serum uric acid and its relationship with metabolic syndrome and cardiovascular risk profile in patients with hypertension: insights from the I-DEMAND study.

BACKGROUND AND AIMS: The independent role of serum uric acid (SUA) as a marker of cardio-renal risk is debated. The aim of this study was to assess the relationship between SUA, metabolic syndrome (MS), and other cardiovascular (CV) risk factors in an Italian population of hypertensive patients with a high prevalence of diabetes. METHODS AND RESULTS: A total of 2429 patients (mean age 62 ± 11 years) among those enrolled in the I-DEMAND study were stratified on the basis of SUA gender specific quartiles. MS was defined according to the NCEP-ATP III criteria, chronic kidney disease (CKD) as an estimated GFR (CKD-Epi) <60 ml/min/1.73 m(2) or as the presence of microalbuminuria (albumin-to-creatinine ratio ≥2.5 mg/mmol in men and ≥3.5 mg/mmol in women). The prevalence of MS, CKD, and positive history for CV events was 72%, 43%, and 20%, respectively. SUA levels correlated with the presence of MS, its components, signs of renal damage and worse CV risk profile. Multivariate logistic regression analysis revealed that SUA was associated with a positive history of CV events and high Framingham risk score even after adjusting for MS and its components (OR 1.10, 95% CI 1.03-1.18; P = 0.0060; OR 1.28, 95% CI 1.15-1.42; P < 0.0001). These associations were stronger in patients without diabetes and with normal renal function. CONCLUSIONS: Mild hyperuricemia is a strong, independent marker of MS and high cardio-renal risk profile in hypertensive patients under specialist care. Intervention trials are needed to investigate whether the reduction of SUA levels favorably impacts outcome in patients at high CV risk.

High fidelity defines the temporal consistency of host-parasite interactions in a tropical coastal ecosystem.

Host-parasite interactions represent a selective force that may reduce hosts' lifespan, their reproductive success and survival. Environmental conditions can affect host-parasite communities, leading to distinct patterns of interactions with divergent ecological and evolutionary consequences for their persistence. Here, we tested whether climatic oscillation shapes the temporal dynamics of bird-haemosporidian associations, assessing the main mechanisms involved in the temporal dissimilarity of their interactions' networks. For two years, we monthly sampled birds in a tropical coastal ecosystem to avian malaria molecular diagnosis. The studied networks exhibited high specialization, medium modularity, with low niche overlap among parasites lineages. Moreover, alpha and ß-diversity of hosts, parasites and their interactions, as well as the structure of their networks were temporally consistent, i.e., stable under fluctuations in temperature or precipitation over seasons. The structure and temporal consistency of the studied antagonistic networks suggest a high fidelity between partners, which is likely relevant for their evolutionary persistence.

The Importance of Forest Simplification and Litter Disturbance in Defining the Assembly of Ground-Foraging Ants.

Currently, we are facing many ecosystem changes derived from years of anthropogenic disturbances. Habitat simplification stands out among human-derived impacts, due to its detrimental effects on vegetation structure and associated biota. Here, we assessed the effects of litter disturbance and forest simplification on a tropical ground-foraging ant community. To do that, we tested whether ant richness will be negatively affected by litter disturbance and habitat simplification. Additionally, we tested whether litter disturbance affects the time of resource discovery and dominance, and if so, whether its effects are intensified by forest simplification. This study occurred at Rio Doce State Park, a preserved area of Atlantic Forest in Southeastern Brazil. We experimentally simulated litter disturbance by removing the leaf litter and superficial soil layer in a mahogany monoculture forest and preserved Atlantic Forest. We sampled ants using paired-mixed baits of protein and carbohydrate in 12 points, half of them in each forest type. As expected, we found higher richness in the preserved and non-disturbed forest. Moreover, resource discovery was faster in disturbed monoculture, but bait dominance was higher in the undisturbed preserved forest. Litter heterogeneity seems to play an important role in determining ant dispersion and intra-specific communication, as we observed that litter disturbance impacts were strengthened by forest simplification. Our results highlight the efficiency of ground-foraging ants as bioindicators of disturbance and habitat quality. Moreover, our study indicates how distinct types of disturbances can act synergistically, changing the assembly of associated biota.

Epidemiological and Pathological Characterization of Feline Injection Site Sarcomas in Southern Brazil.

Feline injection site sarcoma (FISS) is a mesenchymal neoplasm with highly malignant characteristics. These tumours originate in anatomical sites where there has been previous parenteral administration of medicinal substances or implantation of medical devices. The aim of this study was to investigate the epidemiological and pathological features associated with FISS in the southern region of Brazil. The database of the Department of Veterinary Pathology of the Federal University of Rio Grande do Sul was searched for excisional and incisional biopsy samples compatible with FISS submitted between 2007 and 2017. Biopsy reports were reviewed and epidemiological information, including breed, age and sex of affected cats, as well as gross findings including anatomical location and size of the tumour and the presence of tissue invasion, were extracted. Eighty-nine samples were selected based on the established criteria. Most animals were of undefined breed and were female cats with a median age of 10 years. Grossly, 84.8% of the tumours were >2 cm in diameter. Regarding anatomical location, 34.9% of the tumours were located in the subcutaneous tissue of the thoracic wall, 29.2% in the flank, 21.3% in the interscapular region and 14.6% in the limbs. Histologically, the tumours originated in the subcutaneous tissue and were diagnosed as malignant mesenchymal neoplasms. Most were compatible with fibrosarcomas, but variants with features of pleomorphic sarcoma or chondrosarcoma were recognized. All tumours exhibited areas of necrosis and peripheral inflammatory infiltrate, composed predominantly of lymphocytes, plasma cells and macrophages. The results of this study suggest the need for dissemination of information on FISS epidemiology and guidelines for management of this tumour to veterinarians in the region.

Effects of moderate salt restriction on intralymphocytic sodium and pressor response to stress in borderline hypertension.

The effects of a moderate dietary salt restriction on intralymphocytic sodium content and pressor response to stress (mental arithmetic, handgrip, and bicycle exercise) were tested in 25 young subjects with borderline hypertension. The study was performed by a randomized, cross-over, within-patient, experimental design. Diet did not significantly reduce blood pressure at rest but did so significantly in both systolic and diastolic blood pressure during stress and exercise. Variations in diastolic blood pressure induced by stimulation correlated significantly with intralymphocytic sodium content both before and during low-salt diet whereas no correlation was found in the case of systolic blood pressure and heart rate variations. These findings suggest that in young subjects with borderline hypertension, sodium homeostasis and blood pressure regulation are somehow interrelated, and that a moderate dietary salt restriction reduces both intralymphocytic sodium content and pressor response to adrenergic stimulation. This could be useful in preventing the development of sustained hypertension.

Hypolipidemic effects of long-term antihypertensive treatment with captopril. A prospective study.

In 27 hypertensive patients already receiving antihypertensive treatment and with serum total cholesterol levels between 260 and 350 mg/dl, captopril in a dosage of 50 mg twice a day was substituted for one of the drugs they were taking. Patients taking a diuretic continued the same diuretic at the same dosage. After six months of therapy that included captopril, patients resumed their former therapy. Diet and physical activity remained unchanged during the study. Biochemical and blood pressure determinations were performed before captopril was begun, after three and six months of captopril therapy, and three months after the former therapy was resumed. During the regimens that included captopril, the triglyceride value was reduced from 249 to 184 mg/dl (p less than 0.05), the total cholesterol level decreased from 287 to 237 mg/dl (p less than 0.005), and the high-density lipoprotein cholesterol value rose from 40 to 51 mg/dl (p less than 0.005). The reduction in cholesterol was unrelated to blood pressure changes or to changes in serum triglyceride, glucose, or potassium levels. Treatment regimens that included captopril also induced a greater diastolic blood pressure reduction than regimens that did not include captopril. The antihypertensive efficacy of a therapeutic regimen that includes captopril, along with its favorable effect on lipid profile, could be useful in preventing cardiovascular complications in hypertensive patients.

Factors associated with the development of stable hypertension in young borderline hypertensives.

OBJECTIVES: To identify factors predisposing subjects to the development of stable hypertension and to estimate their relative importance in 70 young patients with borderline hypertension monitored for 10 years. DESIGN: Longitudinal evaluation of the incidence of stable hypertension [diastolic blood pressure (DBP) > 95 mmHg]. METHODS: Patients were examined at baseline by determination of resting blood pressure, intracellular sodium level and individual pressor response to mental arithmetic and to intravenous saline loading. They were re-examined after 10 years to assess the prevalence of established hypertension and the importance of some prognostic variables identified prospectively (age, sex, intracellular sodium level, baseline blood pressure, pressor response to stress and acute salt-sensitivity). RESULTS: The prevalence of sustained hypertension (DBP > 95 mmHg) was 35.8% after 10 years of follow-up study. Subjects developing hypertension were older (26.9 +/- 1.3 versus 21.0 +/- 1.8 years) and showed a higher percentage of family history of hypertension (92 versus 64%) and of acute salt-sensitivity (72 versus 53%). The pressor response to mental arithmetic was greater in patients who developed hypertension (systolic blood pressure 26.9 +/- 1 versus 22.7 +/- 0.9 mmHg, P = 0.005 DBP = 16.6 +/- 0.8 versus 13.1 +/- 0.7 mmHg, P = 0.005), who also showed higher levels of intracellular sodium (30.7 +/- 0.6 versus 27.3 +/- 0.5 mmol/kg, P = 0.001). The same variables were found to be related to the development of hypertension in a multivariate analysis and the concomitant presence of 4-5 risk factors was associated with a reasonable predictive power for the identification of patients at high risk (sensitivity 72%, specificity 67%, predictive accuracy 76%). CONCLUSIONS: The present study demonstrates that borderline hypertensives at high risk of stable hypertension can be identified by the concomitant evaluation of some clinical and cellular characteristics directly related to long-term development of high blood pressure.

Pattern of peripheral venous response to volume expansion in borderline systemic hypertension.

An increased venous tone responsible for changes in systemic hemodynamics has been described in borderline hypertensive patients along with the release, in response to intravenous sodium chloride, of an endogenous sodium ion/potassium ion adenosine triphosphatase (Na+/K+ ATPase) inhibitor with vasoconstrictive properties. The hemodynamic and humoral effects of a 2-hour intravenous saline infusion were studied in 25 borderline hypertensives characterized on the basis of their forearm venous distensibility (VV30) in normal (n = 15) and low (n = 10) VV30. VV30 was slightly reduced by saline in the entire hypertensive group (1.47 vs 1.36 ml/100 ml; p less than 0.05), whereas blood pressure and plasma Na+/K+ ATPase inhibitor were unchanged. Normal VV30 showed a sudden increase in plasma Na+/K+ ATPase inhibitor in response to saline associated with an increase in blood pressure, a forearm arterial and venous constriction, and a sluggish suppression in plasma renin activity, whereas low VV30 exhibited a completely opposite pattern. The changes in plasma Na+/K+ ATPase inhibitor inversely correlated to VV30 decreases in borderline hypertensives with normal VV30 (r = -0.49; p less than 0.05), whereas they did not in all hypertensive patients. Atrial natriuretic peptide response to saline infusion was delayed in normal VV30 and inversely related to the changes in Na/K+ ATPase inhibitory activity (r = -42; p less than 0.05) attained after 2 hours of infusion in the entire hypertensive population. Results of this study suggest the ability of acute volume expansion to reduce peripheral venous distensibility in borderline hypertensive patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of captopril to reduce serum lipids in hypertensive patients with hyperlipidemia.

The effects on serum lipids of substituting captopril for other antihypertensive drugs were evaluated in 24 essential hypertensives with stable hypercholesterolemia (total cholesterol 250 to 350 mg/dL). Captopril, 50 mg bid, was substituted for one of the nondiuretic drugs the patients were already taking. Patients on a diuretic continued the same diuretic at the same dosage. After 6 months of treatment including captopril, patients returned for 3 months to their previous therapeutic scheme (rechallenge). Treatment with captopril caused a reduction in total cholesterol (-18%) and triglycerides (-26%) and an increase in high-density lipoprotein (HDL) cholesterol (+27%). When patients returned to their precaptopril therapy, total and HDL cholesterol returned to precaptopril values. These effects of captopril on lipid profile of hypertensive patients with hypercholesterolemia could be important for the reduction of cardiovascular complications in treated hypertensives.

Impaired vasodilator capacity and exaggerated pressor response to isometric exercise in subjects with family history of hypertension.

The nature of the cardiovascular response to isometric exercise is still debated. An adequate blood supply to exercising muscles at the onset of contraction seems to be an important factor controlling the extent of pressor response to isometric contraction. In comparison to normotensive subjects without familiar hypertensive history (F-), normotensive subjects with family history of hypertension (F+) have a reduced peripheral vasodilator capacity which impairs the possibility to adjust the muscular blood flow during exercise. An enhanced pressor response to handgrip test was observed in F+ and this hyperresponsivity was inversely related to the extent of forearm vasodilation capacity and largely prevented by the pretest increase of blood flow in exercising muscles. Our results suggest the importance of local vasodilating capacity as a determinant of reflex pressor response to isometric exercise.

Alarm reaction and serum K+ in hypertensive patients.

The effect of serum K+ of the alarm reaction induced by the participation to an experimental noninvasive study was evaluated in 35 subjects with borderline hypertension and in 18 essential hypertensives. A group of 44 inpatients undergoing routine blood sampling served as a control. Serum K+, blood pressure and heart rate were measured before (casual) and after (baseline) 20 min of rest in the recumbent position. Baseline serum K+ values were significantly higher than casual values in patients participating to the experimental protocol while no change was observed in inpatients undergoing routine blood sampling. The increase in serum K+ induced by relaxation was significantly related to heart rate decrease (r = 0.73). After relaxation 75% of patients had an increase in serum K+ with a change greater than 10% in about 35% of patients. In a subgroup of patients who repeated the same test three times, the alarm reaction was still evident and not reproducible within each patient. These data suggest that when potassium levels are measured in outpatients undergoing diagnostic or experimental procedures falsely reduced levels can be found in a large proportion of subjects.

Atrial natriuretic factor modulates the plasma levels of a Na+/K+ATPase inhibitor in volume expanded borderline hypertensives.

To evaluate the existence of a relationship between atrial natriuretic factor (ANF) and plasma Na+/K+ATPase inhibitory activity in humans, we examined the hemodynamic and humoral response to volume expansion in 41 borderline hypertensive patients (BHT) with either normal (n = 33) or low plasma renin activity (n = 8). The study was carried out by measuring blood pressure, forearm circulation, plasma renin activity (PRA), ANF, and plasma levels of an endogenous Na+/K+ATPase inhibitor before and after 2 h of acute intravenous NaCl infusion (0.22 mL/min/kg bodyweight). The early (45 min) changes of ANF and those of Na+/K+ATPase inhibitory activity attained at the end of saline infusion were inversely related in BHT with normal PRA and directly related in the low-PRA population (r = 0.64). The time-course of ANF response to sodium loading was significantly delayed in BHT characterized by normal venous distensibility. They also showed a greater increase in plasma Na+/K+ATPase inhibitory activity occurring with an hypertensive, vasoconstrictive, and sodium retaining response as well. We conclude that in normal PRA borderline hypertensives, ANF may modulate the release of a plasma Na+/K+ATPase inhibitor in a setting where extracellular volume is acutely expanded. Our findings also suggest that dissimilarities in peripheral venous distensibility are able to influence the time-course of ANF response. The blunted ANF increase observed in response to NaCl loading in a subset of BHT could represent an early marker of the attitude of such patients to develop high blood pressure leading to the release of a Na(+)-pump inhibitor and influencing individual salt-sensitivity.

Characterization of a Na+/K+-ATPase inhibitor from human plasma: preliminary data.

The role of an endogenous sodium pump inhibitor in the pathogenesis of hypertension has been reported in several papers. Unfortunately, because of the unknown structure and lack of biochemical characterization, some discrepancies have arisen. In this study we report a method to obtain extracts from human plasma that are able to inhibit Na+/K+-ATPase in vitro. Preliminary characterization was carried out, which showed that the extracts are able to inhibit Na+/K+-ATPase, pNPPase, and [3H]ouabain binding to red blood cells. The enzyme inhibition is not due to vanadate, FFA, or bivalent cations, and it seems to be reversible, dose-dependent, and largely prevented in E1 conformation of the enzyme. These results seem to support the hypothesis that human plasma contains a sodium pump inhibitor with many characteristics of a "ouabainlike" compound.

Importance of plasma renin activity suppression and venous distensibility on pressor and natriuretic responses to intravenous salt load in borderline hypertension.

Cardiopulmonary receptors influence renin release in a variety of physiological situations and in a fashion related to the degree of peripheral venous distensibility. We studied two groups of borderline hypertensives (BHTs) with different capacities to suppress plasma renin activity in response to saline infusion (0.20 mL/kg/per minute for 2 hours). Those BHTs with low suppressive capacity (L-supp) showed an increased venous distensibility in comparison with those with high suppressive capacity (H-supp). Saline infusion led to a significant increase in blood pressure only in L-supp BHTs, which was associated with enhanced 24-hour postloading natriuresis and raised plasma levels of an Na/K ATPase inhibitor (+12.2%). This result underlines the importance of venous distensibility as a determinant of pressor and humoral response to acute volume expansion.

Short-term plasma renin activity suppression by saline and release of a plasma endogenous Na/K ATPase inhibitor in essential hypertension.

The present study was conducted in 15 essential hypertensives to evaluate the modifications of plasma levels of an endogenous Na/K ATPase inhibitor, blood pressure, forearm hemodynamics and plasma renin activity (PRA) elicited by an intravenous saline infusion (0.9% NaCl at the mean rate of 0.22 mL/min/kg body weight for 2 h). The response to saline was determined in the whole hypertensive population as well as in two subgroups of patients classified according to their rate of PRA suppression in response to volume expansion by comparison with normotensive controls (Normal- and Low-suppressors: N-S, L-S). Over the whole group of hypertensive patients, NaCl load provoked an increase in Na/K ATPase inhibitory activity, measured by enzyme-coupled assay, which was linearly related to PRA decline (r = 0.73) and to the increase in mean blood pressure (r = 0.57). These effects were clearly enhanced by considering L-S patients alone. Urinary Na/K ratio after saline infusion was significantly higher in L-S as result of a lesser potassium excretion in this subgroup. Our results support the hypothesis that acute volume expansion with saline causes an increase in plasma levels of an endogenous sodium pump inhibitor with hemodynamic effects and whose release is related to the individual handling of infused fluids and to the degree of renin-angiotensin-aldosterone suppression.

Hemodynamic and humoral effects of chronic antihypertensive treatment with fenquizone: importance of aldosterone response.

The effects of 1-year antihypertensive treatment with the diuretic fenquizone were evaluated in 16 patients with mild essential hypertension. During treatment with placebo, after 2, 4, 24, and 52 weeks of treatment we measured blood pressure, heart rate, forearm blood flow (FBF) and vascular resistance (FVR) at rest and after 10 minutes ischemia, and forearm venous distensibility. Subjects whose diastolic blood pressure after fenquizone was reduced at least 10% were classified as responders. On this basis, 56% of patients after 1 month and 68% after 1 year responded to fenquizone. Responders, in comparison to nonresponders, were characterized by a greater increase in FBF and a greater decrease in FVR. The reduction in diastolic blood pressure was significantly related to the fall in FVR whereas no correlation was found between blood pressure and venous compliance changes. Nonresponders had a PRA increase similar to that observed in responders but they showed a much greater increase in aldosterone, whose changes were inversely related to modifications of both FVR and blood pressure. Our results demonstrate that chronic therapy with fenquizone causes a reduction of FVR, and that nonresponders have an exaggerated rise in aldosterone. This observation further reinforces the hypothesis that factors influencing the secretion of aldosterone are important determinants of the antihypertensive mechanism of diuretics.

Peripheral hemodynamic and humoral effects of oral zofenopril calcium (SQ. 26,991) in patients with congestive heart failure.

In 14 patients with congestive heart failure (CHF) of various grade (NYHA class 2-4) the effects of zofenopril calcium (SQ 26,991) on blood pressure and forearm circulation were studied by venous occlusion plethysmography. Changes in plasma renin activity (PRA), aldosterone, Atrial natriuretic factor (ANF) and arginine-vasopressin (AVP) were also measured. Two hours after oral administration of 7.5 mg of zofenopril we observed a decrease in blood pressure, heart rate, and forearm vascular resistance along with an increase in venous distensibility. Zofenopril also decreased ANP levels in a manner directly related to peripheral venodilatation (r = .64; P less than .05) and modified arginine-vasopressin (AVP) proportionally to the fall in blood pressure observed in response to drug administration (%SBP/%AVP: r = .64, P less than .05; %DBP/%AVP: r = .67, P less than .05). Hemodynamic and humoral responses to zofenopril occurred without any significant unwanted adverse reaction, even in patients with greater pressor reduction. We conclude that oral acute zofenopril administration, in patients with congestive heart failure, causes an arterial and venous forearm vasodilatation which is probably involved in the acute changes in plasma levels of ANF and AVP observed after drug administration.

Captopril and oxprenolol in a fixed combination with thiazide diuretics: comparison of their antihypertensive efficacy and metabolic effects.

After receiving placebo for two weeks, 20 patients with essential hypertension were randomly divided into two groups. Those in group 1 received a combination of 25 mg of captopril (CPT) and 25 mg of hydrochlorothiazide (HCT) BID. Those in group 2 received a combination of 80 mg of oxprenolol (OXP) and 10 mg of chlorthalidone (CHLT) BID. Patients whose recumbent diastolic blood pressure was less than 95 mmHg after four weeks of treatment continued with the same regimen for six more weeks, while the dosages were doubled for nonresponders. All the patients in group 1 had satisfactory blood pressure readings after the first four weeks of therapy; six patients in group 2 required double dosages to control their blood pressure. Both drug combinations reduced patients' recumbent systolic blood pressure, but CPT + HCT reduced their diastolic and standing systolic blood pressure more effectively. Doubling the dosages of OXP + CHLT was only slightly more effective in controlling patients' blood pressure. In addition, patients who received CPT + HCT showed a significant decrease in serum sodium level, whereas patients who received the double dosages of OXP + CHLT showed a significant increase in serum cholesterol and creatinine levels. The data suggest that low dosages of CPT + HCT control blood pressure more effectively than high dosages of OXP + CHLT and, in addition, do not have any negative metabolic effects.

Antihypertensive efficacy of two low dosages of hydrochlorothiazide in patients treated with captopril.

Twelve patients with essential hypertension (diastolic blood pressure, greater than 90 mmHg) after four weeks of treatment with captopril (50 mg BID) were randomly divided into two groups and treated with 12.5 mg and 25 mg of hydrochlorothiazide OD, in addition to captopril, in a crossover experimental design. Each dosage of hydrochlorothiazide was given for four weeks, with a two-week placebo washout period intervening. Both dosages of hydrochlorothiazide caused significant reductions in blood pressure. Eighty percent of patients achieved a diastolic blood pressure less than 90 mmHg during combination therapy, independent of the dose of diuretic. None of the patients reported significant side effects, and no changes were observed in routine biochemical analysis during treatment. In patients not completely controlled by captopril alone, a once-daily dosage of 12.5 mg of hydrochlorothiazide proved as effective as a 25-mg once-daily dosage. The smaller dosage could result in fewer unwanted metabolic effects induced by diuretic administration.