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O Castro

Publications and source records attributed to O Castro.

At least 55 records · Page 3Linked to original sources
PubMed1993

[10 years of nosocomial infections at the Santo Tomás Hospital].

The incidence of nosocomial urinary tract infections (UTI) in the medical services of Santo Tomás Hospital from 1980 to 1985 was 56% in Neurology Section, 73% in cardiology and 74% in nephrology. These percentages declined, with epidemiological surveillance, to 21%, 31% and 53% respectively, for the period between 1986 and 1990. In the surgical services the incidence of nosocomial UTI was 85% in urology and 15% in general surgery, from 1980 to 1985. The incidence remained unchanged in urology (81%) and general surgery (17%) despite epidemiological surveillance, but decreased in neurosurgery (from 55% to 37%) for the period between 1986 and 1990. Between 1985 and 1990, Staphyloccocus aureus was the most frequently isolated bacterium from surgical wounds (34%) and from patients with intravenous catheters (23%). Pseudomonas aeruginosa was the most frequently isolated bacterium in nosocomial UTI (26%) and respiratory tract infections (45%) and in patients with nosocomial septicemia, it was a species of Klebsiella.

Cross Infection↗
PubMed1991

Left ventricular diastolic filling abnormalities identified by Doppler echocardiography in asymptomatic patients with sickle cell anemia.

To determine whether left ventricular diastolic abnormalities are an early feature of sickle cell anemia, indexes of diastolic filling were obtained with pulsed Doppler echocardiography in 30 consecutive patients with this disease (mean age 29 years; range 19 to 39) who had not experienced symptoms of heart failure and had normal left ventricular systolic function. Data were compared with those in 30 normal control subjects of similar ages. Seventeen (57%) of the 30 patients with sickle cell anemia had evidence of abnormal left ventricular diastolic filling. Six of these 17 patients had a Doppler pattern consistent with "restrictive" filling, characterized by reduced early diastolic deceleration time (less than 110 ms) or an increased rate of decline of early flow velocity (EF slope greater than 7.4 m/s2), or both, as well as decreased late diastolic velocity-time integral (2.6 +/- 0.7 vs. 3.4 +/- 0.8 cm in normal subjects; p less than 0.05). Another 11 patients showed a Doppler waveform consistent with impaired relaxation, characterized by prolonged deceleration time (greater than 166 ms) or reduced EF slope (less than 3.8 m/s2), as well as increased late diastolic velocity-time integral (4.0 +/- 0.5 vs. 3.4 +/- 0.8 cm in normal subjects; p = 0.03). This Doppler echocardiographic analysis demonstrates that left ventricular diastolic filling patterns are altered in patients with sickle cell anemia and that these diastolic abnormalities may be present in the absence of symptoms of heart failure. These abnormal patterns suggest an intrinsic myocardial abnormality in patients with sickle anemia and may prove to be early markers of cardiac disease.

Adult↗
PubMed1991

Effect of the aromatase inhibitor 4-hydroxyandrostene-3,17-dione progesterone synthesis by human luteal cells.

The authors studied the effects of 4-hydroxyandrostene-3,17-dione (4-OHA) on progesterone (P), 17 beta-estradiol (E2), and 20 alpha-hydroxy-4-pregnen-3-one synthesis and pregnenolone accumulation in cultured human midluteal cells. A dose-dependent inhibition with and without human chorionic gonadotropin (hCG) of E2 and P production was observed. The accumulation of pregnenolone was significantly enhanced three to fourfold by 4-OHA in this culture system, as compared with control value. In addition, a sevenfold increase on pregnenolone accumulation was observed in the presence of 4-OHA plus 10 IU of hCG as compared with control values and 2.2-fold as compared with the 4-OHA treatments. These in vitro findings indicate a direct effect of 4-OHA on luteal steroidogenesis. Nevertheless, the suppressive effect of 4-OHA on P and E2 production is located at different sites of the steroidogenic pathway. In addition, the results demonstrate that hCG in the presence of 4-OHA stimulated pregnenolone accumulation, suggesting that the inhibition of P synthesis is in some steps after the formation of pregnenolone. These data indicate that the actions of 4-OHA on P or E2 formation have different inhibitory mechanisms.

20-alpha-Dihydroprogesterone↗
PubMed1991

Osteomyelitis in patients who have sickle-cell disease. Diagnosis and management.

Fifteen patients who had sickle-cell disease and osteomyelitis (affecting thirty bones) were treated with operative decompression and parenteral administration of antibiotics between 1973 and 1988. Organisms were isolated on culture of specimens of bone from all fifteen patients. Parenteral antibiotic therapy was continued for a minimum of six weeks after operative decompression. The osteomyelitis resolved in twenty-nine (97 per cent) of the thirty affected bones after follow-up ranging from two to fifteen years. With their compromised immune status and poor circulation of blood in bone, patients who have sickle-cell disease and osteomyelitis are prone to have complications. In our series, the complications included an adhesive pericapsulitis of the shoulder in two patients, avascular necrosis of the humeral head in one, and a pathological fracture of the femur in one. In four of the fifteen patients, chronic osteomyelitis persisted, but in three of the four, the infections of bone healed six to fourteen months after the initial operative decompression. Staphylococcus aureus was isolated on culture of specimens of bone from eight to the fifteen patients; Salmonella, from six; and Proteus mirabilis, from one. Although Salmonella has been cited as the principal causative organism of osteomyelitis in patients who have sickle-cell disease, in our experience Staphylococcus aureus was the most common infecting organism. Therefore, Salmonella may not be the most common cause of osteomyelitis associated with sickle-cell disease in all countries or in all areas of a particular country.

Adult↗
PubMed1990

Transfusion and alloimmunization in sickle cell disease. The Cooperative Study of Sickle Cell Disease.

In 1,814 patients with sickle cell disease who had been transfused, the overall rate of alloimmunization to erythrocyte antigens was 18.6%. The rate of alloimmunization in this group appears to be an explicit function of the number of transfusions received because it increases exponentially with increasing numbers of transfusions. Alloimmunization usually occurred with less than 15 transfusions, although the rate of alloimmunization continued to increase when more transfusions were given. The rate of alloimmunization was less in patients with hemoglobin SC disease and sickle-beta+ thalassemia because these patients had received fewer transfusions. Children less than 10 years old had a slightly lower rate of alloimmunization than patients in other age groups even after correction for the number of transfusions given. Women were more frequently alloimmunized than men; this was largely due to the fact that women received more transfusions than men, but in the age group 16 to 20 years the increase may have been due in part to alloimmunization owing to pregnancy. Forty-five percent of those alloimmunized made antibodies of only one specificity; 17% made four or more antibodies reacting with different antigens. Antibodies to the C and E antigens of the Rh group, the Kell antigen, and the Lewis antigens were most commonly made. These findings may be important in formulating a rational transfusion policy in sickle cell disease.

Adolescent↗
PubMed1990

Prevalence of antibodies to human immunodeficiency virus and to human T cell leukemia virus type I in transfused sickle cell disease patients.

The prevalence of the human immunodeficiency virus (HIV) antibody and the human T cell leukemia virus type I (HTLV-I) antibody was examined in 116 adults with sickle cell disease. Eighty-eight of them had received a mean of 18.6 transfusions of red blood cells between 1978 and 1985, and none was positive for the HIV antibody. Of 116 patients, 9 (7.8%) tested positive for HTLV-I antibodies. HTLV-I-positive patients were similar to those without HTLV-I antibody with respect to age, number of transfusions, and proportion of patients with greater than 40 transfusions. However, 3 of the 9 HTLV-I-positive patients came from West Africa or from the Caribbean, whereas this proportion was much lower (7/107) in the HTLV-I-negative group (x2, 7.564; P less than .01). Our analysis suggests that the risk of HIV infection in transfused sickle cell disease patients is low. Although HTLV-I antibodies in these patients may not be related to blood transfusions, it seems prudent to screen blood donors for HTLV-I infection.

Adult↗
PubMed1990

Patient-controlled analgesia in patients with sickle cell vaso-occlusive crisis.

Pain control using intramuscular analgesia is often unsatisfactory in sickle cell patients. In a pilot study, 15 patients with sickle cell anemia (SS) and one patient with SB thalassemia in vaso-occlusive crisis were treated with the Patient-Controlled Analgesia (PCA) technique using a Pharmacia Deltec Programmable pump (CADD PCA). Age range was 19-50 years (median = 27); there were nine females and seven males. The protocol consisted of 3 days of therapy using a background of continuous infusion meperidine. The starting dose was 20 mg/hr and was escalated to 30 mg/hr. The average amount given was 25.8 mg/hr. One to two boluses of 2.5-5.0 mg/dose (mode = 5.0) were also allowed each hour. In addition, patients number 8 through 16 were given hydroxyzine (Vistaril) 50 mg PO q6h. The number of days in pain prior to study entry (mean +/- SD) was 3.3 +/- 1.6. The number of pain sites per patient was 3.6 +/- 1.2. Using categorical and analog pain scales, patients' pain scores decreased only about 30%. However, most patients were fairly satisfied with the treatment and rated it overall as follows: 1 poor, 1 fair, 3 good, 6 very good, 4 excellent, 1 no comment. Patients number 8 through 16 gave higher ratings probably because a more idealized dosage regimen was being used by that time in the study. There were no adverse effects or major problems noted. It is our impression that PCA, when optimized, will be a safe and effective alternative method for providing patients with sickle cell vaso-occlusive crisis pain relief.

Adult↗
PubMed1990

Pneumococcal sepsis and meningitis in adults with sickle cell disease.

Patients with sickle cell disease are predisposed to infection caused by Streptococcus pneumoniae. However, there has been only one published case of bacteremic pneumococcal meningitis in an adult with sickle cell anemia. We report here the cases of six adults with sickle cell disease, pneumococcal sepsis, and meningitis. Five patients were male and one was female. Their ages ranged from 18 to 34 years (mean, 25.7 years). Five patients had the SS and one had the SC hemoglobin phenotype. Only one patient had received pneumococcal vaccine (14 valent). This vaccine did not protect against the pneumococcal serotype causing his infection. All patients had high fever (mean, 39.8 degrees C [103.7 degrees F]) on admission; five had generalized weakness and four had neck stiffness. Leukocyte counts were greater than 30,000/mm3 in all patients. Streptococcus pneumoniae was isolated from the blood and the cerebrospinal fluid in all patients. The cerebrospinal fluid showed pleocytosis in six patients, an elevated protein level in five, and hypoglycorrhachia in two. Complications included renal failure in four patients, disseminated intravascular coagulation in one, and seizures in another. Two patients died. Pneumococcal sepsis and meningitis are uncommon in adults with sickle cell disease, but they carry a high morbidity and mortality. Wider use of the new 23-valent polysaccharide vaccine in these patients is recommended.

Adult↗
PubMed1989

Regulation of steroid hormone synthesis by human corpora lutea: failure of follicle-stimulating hormone to support steroidogenesis in vivo and in vitro.

The authors studied the role of follicle-stimulating hormone (FSH) in luteal steroidogenesis by replacing gonadotropin-releasing hormone (GnRH) infusion with pure FSH 48 hours after ovulation in two hypogonadotropic patients. Plasma progesterone (P) and estradiol (E2) decreased after FSH administration. Human luteal cells were cultured for 48 hours in the presence and absence of FSH, human chorionic gonadotropin (hCG), testosterone (T), or dibutyryl cyclic adenosine monophosphate (Bu2cAMP). In the presence of T, E2 synthesis increased significantly, indicating an active aromatase system in these cells. Human chorionic gonadotropin as well as Bu2cAMP significantly increased E2, T, and P synthesis. Follicle-stimulating hormone did not stimulate luteal E2, T, or P synthesis. The authors conclude that FSH does not sustain luteal steroidogenesis. Moreover, the in vitro findings reveal that hCG modulation of luteal E2 synthesis is mediated principally by an increase in androgen precursors. These in vivo and in vitro results confirm a crucial role for luteinizing hormone (LH) in the maintenance of luteal steroidogenesis.

Adult↗
PubMed1987

Excess HLA antigens after transfusion of sickle cell patient with AIDS.

A woman with sickle cell-hemoglobin C disease developed the acquired immunodeficiency syndrome (AIDS), possibly as the result of blood transfusions administered 4 years earlier. Three months after subsequent transfusions, she had excess HLA-A and DR antigens (triplets) on her circulating lymphocytes. Three of her first-degree relatives were HLA-typed, and none had excess antigens. Family studies also indicated that the patient had at least one HLA-A antigen that was probably not inherited. These findings suggest the possibility that transient hemopoietic engraftment can occur in transfused sickle cell patients with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Age and prevalence of sickle-cell trait in a large ambulatory population.

We performed hemoglobin electrophoresis in 30,400 apparently healthy black individuals in the Washington D.C. Metropolitan area, who were participating in a community based sickle-cell screening program during the period 1978-1985. The overall prevalence of sickle-cell trait was 6.7%. The frequency of sickle-cell trait in various age groups, which included young children, adults, and individuals over 65 years of age, ranged from 6.4 to 7.4%. There were no statistically significant differences in the prevalence of sickle-cell trait among the various age groups, nor did we detect a significant trend for increasing or decreasing sickle cell frequency with advancing age (P = 0.418). Thus, in this population sickle-cell trait appears to have no effect on longevity. If the various complications of sickle-cell trait reported in the literature are not fortuitous, their frequency and/or severity must be too low to affect prevalence figures.

Adolescent↗
PubMed1987

In vitro net progesterone production by human corpora lutea: effects of human chorionic gonadotropin, dibutyryl adenosine 3',5'-monophosphate, cholera toxin, and forskolin.

Slices of human corpora lutea (CL) obtained at varying stages of the luteal phase from 21 women were used to study the effect of hCG on progesterone (P4) production. Slices obtained from mid- and late CL incubated with 10 IU/mL hCG exhibited a significant increase in net P4 production (P less than 0.001), whereas slices from early CL did not. Mid-CL slices were the most sensitive to hCG (4.2-fold increase in P4 production compared to 1.2-fold for early CL and 2.7-fold for late CL). To investigate the unresponsiveness of early CL to hCG, [125I]hCG binding was studied. All early CL had LH/hCG-specific receptors, and the apparent Kd for this binding was 1.95 X 10(-10) M. Dibutyryl cAMP (1 mM), cholera toxin (0.84 mM), and forskolin (50 microM) stimulated net P4 production (P less than 0.05) in slices of early CL tissue incubated in the presence of methylisobutylxanthine (0.1 mM). Cholera toxin and forskolin stimulated cAMP formation by the early CL, but hCG failed to do so. These results confirm that hCG has an age-dependent stimulatory effect on CL P4 synthesis. Our findings suggest that there is inadequate coupling of the LH/hCG receptor and adenylate cyclase in the early human CL, which explains in part the relative insensitivity of this tissue to the steroidogenic action of hCG.

Adult↗
PubMed1987

Thoracic extramedullary hematopoiesis in sickle-cell disease.

The radiographic manifestations of thoracic extramedullary hematopoiesis are unilateral or bilateral, smooth, sharply delineated, often lobulated paraspinal masses without erosion of the vertebral bodies or ribs, sometimes associated with subpleural, paracostal masses. These radiographic findings were encountered in eight adult patients with homozygous sickle-cell disease. In one patient, the masses encompassed essentially the entire thoracic paravertebral area bilaterally. In the other seven patients, the masses were unilateral and limited to the region of the eighth to the 12th thoracic vertebrae. Two of the eight patients had lateral subpleural masses that were not contiguous with the paraspinal masses and that were located medial to the lateral portions of the ribs. Follow-up in seven of the cases ranged from 2 to 15 years and demonstrated, after relatively rapid growth initially, either no change in size or slow growth. Each patient was asymptomatic with regard to the thoracic masses. Histologic verification was not available in any case because of the lack of clinical indication for invasive diagnostic or therapeutic procedures. The presence of well-defined unilateral or bilateral paraspinal masses and/or paracostal masses in patients with homozygous sickle-cell disease and without related symptoms should alert one to the possibility of the presence of extramedullary hematopoiesis. These masses tend to be slow-growing and should not be subjected to aggressive diagnostic and therapeutic measures.

Adolescent↗
PubMed1987

Sickle cell leg ulcers are associated with HLA-B35 and Cw4.

We determined the HLA-A, B, C, and DR types in nine patients with sickle cell anemia (SS) who had leg ulcers or a history of leg ulcers, and in 29 control patients with SS without leg ulcers. Six (67%) of the nine patients with leg ulcers had HLA-B35 and each of these six patients also had HLA-Cw4. In contrast, only eight (28%) of the 29 control patients with SS had HLA-B35 and only three (10%) of these patients had both HLA-B35 and Cw4. The relative risk for development of leg ulcers in patients with SS who had both HLA-B35 and Cw4 was 17 times greater than that of patients without these antigens or who had only one antigen. The frequency of HLA-B35 was also significantly higher in patients with SS and leg ulcers than in a reference population (31%) consisting of 68 healthy black persons. These results suggest that genetic factors or an HLA-related altered immune response may contribute to the development of leg ulcers in sickle cell anemia.

Adolescent↗
PubMed1986

Autologous survival of cyanate-treated cryopreserved sickle erythrocytes.

The effects of carbamylation and frozen storage on the autologous 51Cr survival and metabolic features of sickle erythrocytes (S-RBCs) were determined. Red cells from four patients with sickle hemoglobinopathies were treated with 50 mM sodium cyanate for 2 hr (37 degrees C), glycerolized and frozen (-80 degrees C) for 62-153 days. The mean in vitro loss of S-RBCs from the combination of cyanate treatment and cryopreservation was 23.6% ( +/- 3.5 SD). The 2,3-diphosphoglycerate content of the thawed cells did not change significantly. However, ATP levels decreased to about 50% of the corresponding values in fresh, untreated S-RBCs. Despite this decrease in ATP, the mean intravascular survival of the frozen cyanated cells nearly doubled. At the high concentration of cyanate used, the oxygen affinity of S-RBCs increased markedly: Their mean P50 was 13.1 mm Hg ( +/- 1.9SD). The gelation of HbS at zero pO2 was also markedly inhibited in the one sample of cyanate-treated S-RBCs examined. Clinical studies to determine the efficacy of autologous transfusions with extensively carbamylated, cryopreserved S-RBCs should be considered.

2,3-Diphosphoglycerate↗
PubMed1986

Association of HLA and autoantibody in transfused sickle cell disease patients.

This study evaluates autoantibody production in sickle cell disease patients and determines whether genes in the major histocompatibility complex are associated with autoantibody responses. Rheumatoid factor was significantly increased for both male and female patients and was less prevalent in highly transfused patients. Significant increases were also detected in the incidences of antinuclear antibody for females and antismooth muscle antibody for males. Low incidence of antinuclear antibody was significantly associated with HLA-DR3. Significant associations were also found between the incidence of antinuclear antibody and both HLA-A28 and B15.

Adolescent↗