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Biomedical subjects

M Ruiz

Publications and source records attributed to M Ruiz.

At least 145 records · Page 8Linked to original sources

[Characteristics and course of patients over 65 years of age with severe heart failure].

INTRODUCTION AND OBJECTIVES: Although there have been many studies on the prognosis of congestive heart failure, most of them have not provided specific data about older patients. The aim of our study is to evaluate general characteristics and short and medium-term evolution of patients older than 65 years with severe heart failure. PATIENTS AND METHODS: We have carried out a prospective study of all patients older than 65 years admitted to our Department during 1993 due to severe heart failure (functional class III or IV of the NYHA classification), regardless of the etiology. In that year, 84 patients who fulfilled those criteria were admitted. RESULTS: The mean age was 72 +/- 6 years, 56% were male and 44% female. Age distribution was as follows: 36 patients were between 65 and 70 years, 27 between 70 and 75, 8 between 75 and 80, and 13 older than 80. The etiology of heart failure was: ischemic heart disease 44%, valvular heart disease 36%, idiopathic dilated cardiomyopathy 8%, systemic arterial hypertension 7% and other etiologies 5%. Significant systolic dysfunction (left ventricular ejection fraction < 0.45) was present in 36% of the patients. Ten percent of the patients suffered from severe ventricular arrhythmias (ventricular tachycardia or fibrillation). Regarding treatment, 24% underwent valvular surgery, 74% received only medical treatment and coronary angioplasty was performed in one patient. In hospital mortality was 9% (8 patients). After a mean follow-up of 8 +/- 4 months, the probability of survival was 78% at 1 month, 71% at 6 months and 63% at 1 year. The survival rate was better in patients with higher ejection fraction (53% for patients with ejection fractions of less than 0.45, 64% for those with ejection fractions between 0.45 and 0.60 and 79% for those with ejection fractions greater than 0.60). Considering etiology, the survival rate was worse for patients with acute myocardial infarction (30%) and aortic valve stenosis (58%). CONCLUSIONS: Patients older than 65 years admitted to the hospital for severe congestive heart failure represent a heterogeneous population in respect to etiology, systolic function and prognosis. Nevertheless, from this study it appears that a worse prognosis was associated with the lower left ventricular ejection fractions and with certain etiologies; such as acute myocardial infarction or aortic stenosis.

Age Factors↗

Comparison between thallium-201 and technetium-99m-tetrofosmin uptake with sustained low flow and profound systolic dysfunction.

UNLABELLED: Technetium-99m-tetrofosmin uptake was compared to that of 201Tl in the setting of low flow and systolic dysfunction. METHODS: In nine open-chested dogs, a severe left anterior descending (LAD) coronary artery stenosis resulted in a 54.3% mean flow reduction and decreased left ventricular thickening from 21% +/- 1% to -3 +/- 2%. After 30 min, 37 MBq (1 mCi) of 201Tl and microspheres were injected and initial and 2-hr redistribution images acquired. Two hours later, 370 MBq (10 mCi) of 99mTc-tetrofosmin and microspheres were injected and an image was obtained. LAD: left circumflex (LCX) count ratios for both tracers and flows were calculated by well counting postmortem, and 201Tl and 99mTc-tetrofosmin defect magnitudes were determined by quantitative image analysis. RESULTS: LAD:LCx flow ratios were similar during 201Tl and 99mTc-tetrofosmin injections (0.48 +/- 0.04 versus 0.49 +/- 0.05, p = n.s.). Final 201Tl activity (0.66 +/- 0.04) was significantly higher than 99mTc-tetrofosmin (0.55 +/- 0.05; p < 0.05). LAD/LCx 99mTc-tetrofosmin image defect count ratio was similar to 201Tl defect count ratio on the initial rest 201Tl scan (0.57 +/- 0.03 versus 0.56 +/- 0.02, p = ns), but significantly less than 201Tl defect count ratio at 2 hr (0.57 +/- 0.03 versus 0.65 +/- 0.02, p < 0.05). CONCLUSION: In a low-flow model with profound systolic dysfunction, myocardial 99mTc-tetrofosmin uptake ( > 50%) reflective of viability was observed in the asynergic zone perfused by the stenotic LAD.

Animals↗

Providing location-independent access to patient clinical narratives using Web browsers and a tiered server approach.

Health care today depends upon timely access to patient medical data and the latest medical knowledge. As we make the transition from a hospital-based organization to an integrated health care delivery system, patient care information must move throughout the organization quickly and efficiently over increasing distances. The emergence of widely-dispersed referral networks demands novel solutions to the problems of delivering patient care information to providers. We have developed a mechanism to provide location-independent access to clinical narrative reports using a multi-tiered server model and World Wide Web technologies for delivery. To successfully deploy such a system to sites separated by large distances, it is important to reduce complexity at the client site. Using a "thin client", such as a web browser, in our design facilitates deployment and support while reducing cost per user. This architecture allows the application to be updated without modification to the end-user software and eases maintenance over long distances.

Computer Communication Networks↗

[Autoimmune hypoglycemia syndrome with specific anti-human insulin antibodies].

A 33 year old woman with episodes of severe hypoglycemia is presented. The studies showed anti-insulin antibodies and variable C-peptide levels. Circulating insulin measured after acid-ethanol extraction, was of 1,600 uU/ml and shown to be human insulin after characterization by HLPC. Specific anti-human insulin antibodies were of high affinity (Ka1: 6.20 x 10(10) M-1; Ka2: 2.42 x 10(9) M-1). A small cross-reactive porcine and bovine antibody subpopulation was also detected (IgG, light k type chain). Plasmapheresis was undertaken when symptoms were spontaneously declining and turned antibody title negative. Prolonged follow-up showed no relapse of this syndrome.

Adult↗

[Colonic tuberculosis as a cause of rectal bleeding in 2 patients with HIV infection].

BACKGROUND: Extrapulmonary tuberculosis is a relatively frequent disease in patients with HIV infection. This may be observed coinciding with pulmonary involvement or without diagnostic data of the same. Within extrapulmonary involvement, gastrointestinal involvement is one of the least frequently observed and its diagnosis is very difficult due to the scarce clinical suspicion because of the unspecific symptomatology. METHODS: Segmentary colonic tuberculosis was diagnosed in two patients presenting rectal bleeding. The diagnosis was neither clinically nor endoscopically suspected and only histologic and microbiologic study of the biopsies led to establishment of the diagnosis. Pulmonary involvement was also seen in one of the 2 patients. RESULTS: Medical treatment was initiated following the diagnosis. The evolution was good in one patient, while the other developed a picture of massive rectal bleeding requiring surgical resection following which the patient died due to complications. CONCLUSIONS: Colonic tuberculosis is an infrequent disease in patients with HIV infection. Only a high index of clinical suspicion along with adequate histopathologic and microbiologic study of all the colonic lesion biopsies can establish the real frequency of this disease in this group of patients.

Adult↗

Alterations in dense LDL subfractions in normolipidemic IDDM patients.

Low density lipoproteins (LDL) of human plasma, consist of a continuum of particles subclasses with distinct physicochemical, immunological and hydrodynamic characteristics. Such structural differences are intimately linked to atherogenesis. The current study was designated to investigated the LDL subclasses profile in 12 normolipidemic IDDM patients, and compare it with 11 healthy controls. Four plasma LDL subfractions were isolated by sequential ultracentrifugation in the density range (1.025-1.063 g/ml) and were characterized by their content of free and esterified cholesterol, triglycerides, phospholipids, and proteins. The net electrical charge was evaluated. Plasma concentration of the two denser LDL subfractions were higher in IDDM patients vs control subjects, due to an increase in cholesterol (free and esterified) and phospholipids, while more buoyant subfractions in the two groups were not different. In IDDM patients the LDL profile was skewed towards the dense subclasses LDL-III and LDL-IV, being significant this increase for LDL-IV: 22.3 +/- 5.2 vs 18.3 +/- 4.0%, p < 0.05, X +/- DS. In the healthy controls the LDL profile was skewed toward the lighter subclasses (LDL-I and LDL-II), being significant for LDL-II: 30.0 +/- 4.3 vs 23.3 +/- 4.2%, p < 0.005. Diabetic patients, even those who are normolipidemic, present increased risk of premature atherosclerosis. This suggest that normal values in lipid and lipoprotein profile can mask deeper alterations, such as changes in the composition and distribution of the denser subclasses, whose characteristics make them potentially more atherogenic. Despite the apparently normolipidemic status, dense LDL particles considered to be atherogenic, are increased in IDDM patients.

Adult↗

Characterization of an Na(+)-dependent glutamate/aspartate transporter from cultured Bergmann glia.

The properties of a transport system specific for L-glutamate and L-aspartate activity expressed in Bergmann glia cells from chick cerebellum were examined. The uptake of D-[3H]aspartate was inhibited by the endogenous substrates L-aspartate (Ki = 62 microM) and L-glutamate (Ki = 60 microM). Of the identified uptake inhibitors, L-aspartate-beta-hydroxamate (Ki = 900 microM), L-alpha-aminoadipate (Ki = 2000 microM), 4,4'diisothiocyanatos-tilbene-2,2'-disulphonic acid (DIDS) (Ki = 1000 microM) and 4-acetamido-4'-isothiocyanatostilbene-2,2'-disulphonic acid (SITS) (Ki = 100 microM) inhibited D-[3H]aspartate uptake. Northern blot analysis, revealed the expression of a chick homologue of a the rat brain L-glutamate/L-aspartate transporter (GLAST). These data suggest that GLAST may be involved in the regulation of the parallel fibre-Purkinje cell synapse ensheathed by Bergmann glia.

ATP-Binding Cassette Transporters↗

Comparison of thallium-201 resting redistribution with technetium-99m-sestamibi uptake and functional response to dobutamine for assessment of myocardial viability.

BACKGROUND: 201Tl scintigraphy is useful for determination of viability in patients with coronary artery disease and depressed left ventricular function. Whether 99mTc sestamibi is adequate for viability detection remains controversial. The primary goal of this study was to compare 99mTc-sestamibi uptake with 201Tl uptake in canine models of sustained low flow and regional asynergy for determination of viability. A secondary objective was to compare myocardial uptake of these tracers with the functional response to low-dose dobutamine. METHODS AND RESULTS: In protocol 1, 14 open-chested, anesthetized dogs with a 50% reduction in resting left anterior descending coronary artery (LAD) flow underwent 1 hour of transient LAD occlusion followed by reperfusion through the severe stenosis. Then 1.0 mCi of 201Tl was injected, and serial imaging was performed 5 minutes and 2 hours later. After acquisition of the delayed 201Tl image, 10 mCi of 99mTc sestamibi was injected, and imaging was repeated 45 minutes later. No significant difference was seen between the 201Tl defect ratio (LAD/left circumflex coronary artery [LCx]) on redistribution images (0.62 +/- 0.02) and 99mTc-sestamibi defect ratio (0.60 +/- 0.02). Similarly, LAD/LCx activity ratios by gamma-well counting were comparable (0.62 +/- 0.02 versus 0.59 +/- 0.04) and reflected the flow decrement. Systolic thickening was -11 +/- 3% at the time of tracer injection. In protocol 2, 16 dogs underwent serial 201Tl and 99mTc-sestamibi imaging during a 50% reduction in LAD flow with no superimposed transient LAD occlusion. In this model, the 99mTc-sestamibi LAD/LCx image defect ratio (0.61 +/- 0.03) was significantly less than the 201Tl redistribution image defect ratio (0.66 +/- 0.03, P < .01). In 10 dogs, the stenosis was released, resulting in a significant increase in systolic thickening (P = .003), which increased further in response to 5 micrograms.kg-1.min-1 of dobutamine (P = .02). In contrast, thickening increased only from -7 +/- 3% to 2 +/- 4% (P = .004) in response to dobutamine infusion in the remaining 6 dogs with persistent severe LAD stenoses. In protocol 3, 5 dogs received both 201Tl and 99mTc sestamibi to compare the degree of delayed redistribution between tracers at 2 hours. The LAD/LCx microsphere flow ratios when 201Tl and 99mTc sestamibi were injected were 0.44 +/- 0.06 and 0.43 +/- 0.05 (P = NS), respectively. The LAD/LCx activity ratio by gamma-well counting was greater for 201Tl (0.56 +/- 0.08) than 99mTc sestamibi (0.50 +/- 0.07) at 2 hours of redistribution (P < .05), indicating greater redistribution for 201Tl. The LAD/LCx 99mTc-sestamibi defect ratios on serial imaging improved from 0.49 +/- 0.07 to 0.52 +/- 0.07 (P = .0005), consistent with a slight amount of 99mTc-sestamibi redistribution. In protocol 4, no difference between 201Tl and 99mTc-sestamibi defect magnitudes was seen in 4 dogs undergoing 3 hours of total LAD occlusion and ligation of visible coronary collaterals. Infarct size was 68 +/- 19% of the risk area. CONCLUSIONS: Although 99mTc-sestamibi and 201Tl defect magnitudes and regional activities were comparable in dogs with sustained low coronary flows and superimposed subendocardial infarctions and in dogs with large infarctions, approximately 5% more 201Tl than 99mTc-sestamibi uptake was observed in dogs with chronic low flow and severe systolic dysfunction. Substantial 99mTc-sestamibi uptake in asynergic zones was observed in this low-flow model, with some slight resting 99mTc-sestamibi redistribution observed on serial images. Systolic thickening was negligibly enhanced during dobutamine infusion in dogs with sustained low flow, whereas 201Tl uptake was only mildly reduced.

Animals↗

Incidence of specific etiology and role of methods for specific etiologic diagnosis of primary acute pericarditis.

To assess the incidence of a specific etiology and the role of methods for specific etiologic diagnosis in patients with primary acute pericarditis, we studied 100 patients with primary acute pericarditis consecutively admitted to our hospital between 1991 and 1993. A general diagnostic protocol was performed in all patients, whereas only pericardiocentesis was performed in patients with clinical cardiac tamponade or an unfavorable course with anti-inflammatory drugs. Surgical drainage and pericardial biopsy was performed in patients with tamponade relapse. A specific etiology was discovered in 22 patients (22%) (neoplasms in 7, tuberculosis in 4, other infections in 3, collagen diseases in 3, thyroid disorders in 4, and dissecting aortic aneurysm in 1). The general diagnostic protocol led to a specific diagnosis in 15 patients (68% of all patients with specific acute pericarditis) and pericardiocentesis in the other 7 patients (32%). The role of a diagnostic protocol, therapeutic pericardiocentesis, and diagnostic pericardiocentesis was similar and complementary. Pericardial biopsy results were negative in the 5 patients in whom it was performed. Cardiac tamponade and an unfavorable clinical outcome were significantly (p < 0.001) associated with the finding of a specific etiology; when both features were combined, sensitivity was 86% and specificity 85%, positive predictive value 63% and negative predictive value 96%. We conclude that the specific etiology in patients with primary acute pericarditis is about 20% to 25%, and that about 90% of these specific cases can be discovered by using the described systematic diagnostic protocol only in patients with an unfavorable outcome (cardiac tamponade or poor clinical course).

Acute Disease↗

Comparison between 201Tl and 99mTc sestamibi uptake during adenosine-induced vasodilation as a function of coronary stenosis severity.

BACKGROUND: Myocardial uptake of either 201Tl or 99mTc-sestamibi (sestamibi) is known to plateau at high coronary flow rates. However, few direct comparisons have been made between these tracers to determine what effect differences in the uptake plateau for the two tracers may have on the detection of coronary stenoses of various severities. METHODS AND RESULTS: Twenty-two dogs were instrumented with flow transducers on the left anterior descending (LAD) and circumflex (LCx) arteries. In 6 nonstenotic dogs, adenosine was infused directly into the LAD, whereas 16 dogs with either critical (n = 7) or mild (n = 9) LAD stenoses received an intravenous infusion. At peak flow, 201Tl (0.5 mCi), sestamibi (5 to 8 mCi), and radiolabeled microspheres were injected simultaneously. Five minutes later, dogs were killed, and ex vivo imaging of heart slices and gamma-well counting of multiple myocardial samples was performed. Neither 201Tl nor sestamibi uptake increased in direct proportion to flow. In the 6 nonstenotic dogs, a fivefold increase in LAD flow increased 201Tl and sestamibi uptake by only 202 +/- 6% and 138 +/- 4%, respectively (P < .0001). In the dogs with critical stenosis, the ratios of stenotic to normal activity by well counting for 201Tl (0.37 +/- 0.05) and sestamibi (0.53 +/- 0.06) underestimated the microsphere-determined flow disparity (0.17 +/- 0.03) (P < .005), but the degree of underestimation was greater for sestamibi (P = .001). Similarly, in the dogs with mild stenosis, the stenotic-to-normal ratio for 201Tl (0.62 +/- 0.04) approximated the flow ratio (0.43 +/- 0.04) better than sestamibi (0.79 +/- 0.03) (P < .0001). Sestamibi defects, however, were visually identifiable on the images of the myocardial slices. By image quantification, sestamibi defect magnitude (LAD-to-LCx count ratio) in the critical stenosis group (0.62 +/- 0.05) was significantly less than in the mild stenosis group (0.80 +/- 0.02) (P < .01). CONCLUSIONS: Thus, with adenosine-induced hyperemic flow, both 201Tl and sestamibi significantly underestimated the magnitude of the flow disparity between stenotic and normal perfusion beds. The degree of underestimation was greater for sestamibi. The clinical implication of these experimental findings for vasodilator perfusion imaging remains to be determined, since factors such as greater redistribution and scatter with 201Tl could offset its advantages.

Adenosine↗

Prevalence of infection by human T-cell leukemia virus types I and II in southern Spain.

To assess the spread of human T-cell leukemia virus (HTLV) type I and II in different population groups at potential risk of infection in Spain, a total of 756 subjects were studied: 453 belonging to groups at risk for retrovirus infection, 255 with diseases potentially linked to HTLV-I/II infection and 48 immigrants from endemic areas. An HTLV-I viral-lysate enzyme immunoassay (EIA) with a recombinant transmembrane envelope protein incorporated was used to screen serum samples. Reactive specimens were confirmed by Western blot strips spiked with recombinant proteins that differentiated HTLV-I from HTLV-II. Infection was then verified by the polymerase chain reaction (PCR). Serum samples from 19 of the 756 subjects analyzed (2.5%) were reactive for HTLV by EIA. One of these was from an intravenous drug user (IVDU) in whom HTLV-II infection was confirmed by Western blot and PCR; a specimen from another IVDU showed Western blot reactivity for both retroviruses, but PCR results were negative. Lastly, Western blot confirmed the presence of HTLV in one of the immigrant subjects. Western blot did not verify HTLV infection in the remaining 16 cases, indicating a high rate of nonspecific anti-HTLV reactivity when a second-generation EIA screening test was applied. These results suggest that HTLV is present in Spain among populations at high risk for HTLV, although at a very low rate and restricted to intravenous drug users and individuals immigrating from endemic areas.

Blotting, Western↗

Synthesis, characterization, and crystal structure of [Cu(cinoxacinate)2].2H2O complex: a square-planar CuO4 chromophore. Antibacterial studies.

The structural and spectroscopic properties of a new copper (II) complex of cinoxacin (HCx) have been investigated. The complex [Cu(Cx)2].2H2O crystallizes in the monoclinic system, space group P2(1)/c. The cell dimensions are: a = 7.998(2), b = 7.622(1), c = 18.955(6) A, beta = 94.38(2) degree, V = 1154.6(6) A3, Z = 2. The structure was refined to R = 0.051. The crystal is composed of [Cu(Cx)2] units and uncoordinated water molecules. The Cu(II) ion, at a center of symmetry, is coordinated to two cinoxacinate (Cx) ligands related by the inversion center. Each cinoxacinate acts as bidentate ligand bonded to the cation through its carboxylate oxygen atom and through its exocyclic carbonyl oxygen atom, resulting in a CuO4 chromophore in a crystallographically planar configuration. The complex was screened for its activity against several bacteria, showing the same antimicrobial activity as the corresponding ligand.

Cinoxacin↗

CD8+ T cell subsets in aging.

Infections are major cause of illness and death amongst elderly people. Peripheral blood CD8+ T lymphocytes -which play a crucial role in host defence against viral infections-. are divided in subsets based upon the expression of several cell and activation markers. Since in senescence changes in peripheral blood CD8+ T lymphocyte compartment have been described, studies were performed to determine whether in aging there are variations in the peripheral blood CD8+CD38+, CD8+CD57+, CD8+HLA-DR+, CD8+CD45RA+ and CD8+CD45RO+ cell subset. A decrease in the CD8+CD45RA+ lymphocytes was observed, indicating that variations in the CD8+ compartment can take place with ageing.

ADP-ribosyl Cyclase↗

[Acute myocarditis with severe cardiac dysfunction in the pediatric population. The evolution and differential characteristics with respect to adult myocarditis].

AIMS: The aim of our study was to assess the spontaneous outcome of acute myocarditis associated with severe cardiac dysfunction in children, as well as to compare these features with those occurring in adult patients. METHODS: Fifty patients consecutively diagnosed of acute myocarditis during the last 7 years in our hospital were studied; 15 patients were children younger than 14 years, and 35 were adults. Immunosuppressive therapy was not used in any patient. RESULTS: Mean age was 2 +/- 3 years in children, ranging from 2 months to 12 years. One patient required temporary pacing for a third-degree atrioventricular block, while the remaining 14 children had severe congestive heart failure, with a left ventricular ejection fraction of 30 +/- 12% (16 to 44%). After a mean follow-up of 21 +/- 26 months, only 3 children died, at 1, 4 and 10 months after the initial diagnosis. Death was sudden in all 3 patients. Left ventricular ejection fraction rose to 45 +/- 14% at 1 month after diagnosis, and to 58 +/- 15% at the end of follow-up. Unfavorable evolution (death or evolution to chronic dilated cardiomyopathy, with a left ventricular ejection fraction < 45%) occurred in 6 children (40%) at 1 month after diagnosis and in only 4 (25%) at the end of follow-up. The 9 children with 1-month favorable outcome were alive and had an ejection fraction > 45% at long-term, while only 2 of the 6 children with 1-month unfavorable outcome were alive and had an ejection fraction > 45% at long-term. Only the 3 children who died had an ejection fraction < 30% at 1-month. Favorable outcome was more frequent in children that in adult patients with acute myocarditis (75% versus 46%). CONCLUSIONS: The outcome of acute myocarditis with severe cardiac dysfunction was favorable in a majority of pediatric patients; this favorable evolution was less frequent in adults. Patients in whom left ventricular ejection fraction did not increase at short-term had a higher risk of death, and they should probably be considered for heart transplantation.

Acute Disease↗

[Blood fractionation based on the extraction of the buffy-coat layer. Analysis of our results].

PURPOSE: To compare a procedure of blood processing via a quadruple bag for the preparation of white-cell-poor blood components with the results obtained with triple-bag-system, in order to adopt it as routine in our blood centre. MATERIAL AND METHODS: Blood was collected in 289 quadruple-bag-system containing 63 mL of CPD as anticoagulant and 100 mL of SAG M solution as additive for the red cells. We used 237 standard quadruple-bags supplied by Fenwal (195) and NPBI (42), and 52 of the top-and-bottom system supplied by Fenwal. Blood separation was made automatically by CompomatR (NPBI) and platelet concentrates were prepared from the buffy-coat fraction. Standard bags were processing as follows: After the first centrifugation of the whole blood (28,800 g), the plasma was transferred into the 300-mL bag until the interface of red cells and plasma was detected; then approximately 80 mL of plasma and buffy-coat (BC) were collected into the 100-mL satellite bag. Top-and-bottom bags were centrifuged at 43,500 g., the red-cells were transferred into the bottom-bag containing SAGM, and plasma was transferred into the top-bag. The buffy-coat fraction remains in the original bag. In both procedures, platelet concentrates were prepared from buffy-coat fraction. After the centrifugation of this fraction (1,400 g and 1,600 g), the supernatant (concentrated platelets in plasma) was transferred into a 300-mL bag and the bag with the residual buffy-coat was then discarded. 287 triple-bags were separated in the traditional way, using platelet-rich plasma (PRP) as a source for the preparation of platelet concentrate (PC). Volumes were measured by weigh and specificity gravity. Platelet, leukocytes and red-cells were counted in the Coulter-Counter (STKR.Izasa). T-Student test and Chi2 test were used for statistical analysis and p < 0.05 was taken as a significant difference between samples. RESULTS: The three kinds of quadruple-bags showed results very homogeneous with little differences. For all brand of bags packed-red-cells showed a volume of 300 +/- 2.9 mL, EVF of 51.9 +/- 0.7%. The recovery of red cells into the packed red cells and of platelets into the platelet concentrate was 90 +/- 0.4 percent and 69 +/- 2 percent respectively, of the original value. White cells in the packed red cells were 9.7 +/- 03 x 10(9) with recovery of 30.1 +/- 1.4 percent of the original value; statistical difference was found in comparison with triple bags PRC (p < 0.001). The PC volumes averaged 71 +/- 1 mL and the overall mean platelet concentration was 77 +/- 2 x 10(9). Eighty three percent of PC contained more than 55 x 10(9). White cells contamination of platelet concentrates was 0.283 +/- 0.039 x 10(9), with a recovery of 9.5 +/- 1.5 percent of the leukocytes present in the whole blood. This value is below the threshold that prevents febrile reactions and microaggregate formation. The plasma yield in the quadruple-bag system was much greater than that in the triple-bag system (p < 0.001). With this process we removed about 77 +/- 0.5 percent of the plasma present in the original unit in comparison with 56 +/- 1 percent removed in that of the triple-bag system. CONCLUSION: With this procedure leukocyte-poor blood components are obtained in which more of 90 percent original white cells have been removed, with a red-cell recovery of 90 percent. Moreover, the plasma yield is also excellent.

Blood Platelets↗

[Efficacy and tolerance of doxazosin in the treatment of isolated systolic hypertension in hypertensive patients over 60 years of age].

Isolated Systolic Arterial Hypertension (ISAH) is the most frequent form of AHT in the aged population, resulting in an increase of the cardiovascular risk, mainly at the cerebrovascular level. In this open non-comparative study, we analyze the effect of doxazosin, an alpha-adrenergic blocker in 40 patients older than 60 years, diagnosed of isolated systolic hypertension. After 2 weeks of lavage, the patients received treatment with doxazosin according to a monotherapy scheme, with progressive increase of the dose, from 1 to 16 mg/day during a period of 14 weeks. Doxazosin significantly reduces the systolic and diastolic arterial pressure (p < 0.001) with a therapeutical response in 86.5% of the cases, using an average dose of 3.4 mg/day and without observing modifications in the heart rate. This drug improves the lipidic profile, with a reduction of the plasmatic levels of total cholesterol and cholesterol linked to low density proteins (LDL) with p < 0.05 and a reduction of triglycerides. Among the 40 patients included in the study, 10 (25%) referred side effects; there were 2 drop-outs (5%) and the dose had to be reduced in 2 patients (5%). In conclusion, doxazosin shows its antihypertensive effectiveness in the treatment of isolated systolic hypertension in patients older than 60 years and it is well tolerated by most of the patients, improving at the same time the lipidic profile. Hence, it contributes to the reduction of the cardiovascular morbidity-mortality in this group of patients.

Age Factors↗

Effect of N-0861, a selective adenosine A1 receptor antagonist, on pharmacologic stress imaging with adenosine.

UNLABELLED: N6-endonorboman-2-yl-9-methyladenine (N-0861) is a drug which inhibits the A1 adenosine receptor subtype. One proposed use for N-0861 is to eliminate A1 receptor-mediated side effects such as A-V heart block and possibly angina in patients undergoing pharmacologic stress with adenosine. The goal of this study was to determine whether N-0861 has any crossover effect on the A2 vasodilatory action of adenosine or on 201TI uptake which would adversely affect imaging of coronary stenoses. METHODS: In eight dogs with critical left anterior descending (LAD) stenoses, we compared the hemodynamic response to intravenous adenosine (250 micrograms/kg/min) before and after N-0861 administration. LAD and left circumflex (LCx) coronary flows were measured ultrasonically and regional blood flow was assessed using microspheres. Thallium-201 (18.5-37.0 MBq) was injected during adenosine hyperemia while N-0861 was present. Imaging of heart slices was performed and defect magnitude was calculated as LAD:LCx count ratios from regions of interest (ROIs) on images. Regional 201Tl activity and microsphere flow were determined by gamma well counting. RESULTS: There was no change in mean heart rate, arterial and left atrial pressures, +dP/dt, and ultrasonically measured LAD and LCx coronary flows upon N-0861 administration. In addition, adenosine evoked a similar hemodynamic response after N-0861. There was also no change in coronary flow in the critically stenotic LAD but LCx flow tripled to 106 +/- 14 ml/min (p < 0.01). CONCLUSION: These data indicate that N-0861 pretreatment does not adversely affect adenosine A2 receptor-mediated vasodilation and has no effect on the detection of a critical coronary stenosis by 201Tl imaging. Thus, the pretreatment strategy may prove useful for the elimination of A1 receptor-mediated side effects during pharmacologic stress imaging with adenosine.

Adenine↗