The influence of noninherited maternal HLA antigens in pediatric renal transplants.
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Adolescent↗
Biomedical subjects
J A Ramirez
Publications and source records attributed to J A Ramirez.
Biochemical markers of renal osteodystrophy in pediatric patients undergoing CAPD/CCPD.
Serum intact PTH [1-84] levels were evaluated as a potential non-invasive method for the diagnosis of renal osteodystrophy in children treated with CAPD/CCPD. Sixty-eight bone biopsy samples were obtained from 55 patients, aged 13 +/- 5 (X +/- SD) years, undergoing CAPD/CCPD for 29 +/- 13 months; osteitis fibrosa was present in 34 cases, mild lesions of secondary hyperparathyroidism in six, 15 had adynamic lesions, and 13 were classified as normal histology. Serum calcium levels were higher in patients with adynamic bone or normal bone histology than in those with secondary hyperparathyroidism, whereas serum phosphorus, alkaline phosphatase and PTH levels were greater in patients with osteitis fibrosa. The combination of a serum PTH level > 200 pg/ml and a serum calcium value < 10 mg/dl was 85% sensitive and 100% specific for identifying patients with high-turnover lesions of bone. Serum PTH values < 200 pg/ml were 100% sensitive but only 79% specific for patients with adynamic bone; specificity increased to 92%, however, using the combined criteria of a PTH level < 150 pg/ml and a serum calcium level > 10 mg/dl. Higher serum calcium levels and serum PTH values within or below the normal range characterize patients with the adynamic lesion of renal osteodystrophy. Serum PTH levels of approximately 200 pg/ml are useful for distinguishing patients with low-turnover lesions of renal osteodystrophy from those with secondary hyperparathyroidism.
Adolescent↗
Development of adynamic bone in patients with secondary hyperparathyroidism after intermittent calcitriol therapy.
Intermittent calcitriol therapy is commonly used to treat secondary hyperparathyroidism in patients undergoing regular dialysis, but there is little available information about the histologic response of bone to this form of therapy. Accordingly, 14 children and adolescents with biopsy-proven secondary hyperparathyroidism were treated with intermittent oral or intraperitoneal doses of calcitriol for 12 months. Biochemical indices of mineral metabolism including serum intact PTH levels were measured monthly throughout the study, and bone biopsies were repeated at the end of treatment. Before treatment, 11 patients had osteitis fibrosa and three had mild lesions of secondary hyperparathyroidism. Histologic improvement was seen in 12 of 14 patients, and osteitis fibrosa resolved in 10 of 11 cases. Bone formation decreased in all patients during intermittent calcitriol therapy, falling from 861 +/- 380 to 150 +/- 170 microns2/mm2/day, P < 0.001. Bone formation decreased to normal in six patients, but six patients developed adynamic lesions of bone with subnormal bone formation rates. Serum PTH and alkaline phosphatase levels declined in those who developed adynamic bone, but values remained elevated in patients with normal rates of bone formation at follow-up evaluation. Neither the mean dose of calcitriol nor the average dose per kilogram body weight differed in patients with adynamic lesions. Thus, adynamic renal osteodystrophy develops in a substantial number of patients during intermittent calcitriol therapy. Although declining serum PTH and alkaline phosphatase levels suggest the development of the adynamic lesion, bone formation decreases in some patients despite persistently high serum PTH levels. Calcitriol may directly suppress osteoblastic activity in patients with secondary hyperparathyroidism when given in large doses to patients undergoing peritoneal dialysis.
Adolescent↗
HIV-negative "AIDS" in Kentucky: a case of idiopathic CD4+ lymphopenia and cryptococcal meningitis.
Here we describe a case of unexplained CD4+ T-lymphocyte depletion and cryptococcal meningitis in a patient without evidence of human immunodeficiency virus (HIV) infection. This newly recognized syndrome has been named idiopathic CD4+ lymphopenia (ICL). When HIV infection is suspected in a patient with an opportunistic infection, a CD4+ lymphocyte count should be obtained, even if the patient's HIV test is negative. Patients with persistently low CD4 counts (< 300 cells/microL, or < 20%) who show no evidence of HIV infection, who have no defined immunodeficiency, and who are not receiving therapy associated with CD4 depletion have disease that meets the definition of ICL, and the case should be reported to the Centers for Disease Control.
Acquired Immunodeficiency Syndrome↗
Calcitriol therapy and calcium-regulated PTH secretion in patients with secondary hyperparathyroidism.
Calcitriol lowers serum parathyroid hormone (PTH) levels in patients with secondary hyperparathyroidism, but its effect on calcium-regulated PTH release remains controversial. Thus 11 patients with secondary hyperparathyroidism underwent dynamic tests of parathyroid function before and after 4 mo of intermittent calcitriol therapy. Serum calcitriol levels rose from 8 +/- 1 to 55 +/- 9 (SE) pg/ml, P < 0.01, serum total and ionized calcium levels increased, and serum PTH levels decreased from 584 +/- 154 to 154 +/- 31 pg/ml, P < 0.05. The maximum increase in serum PTH during hypocalcemia did not differ before (248 +/- 78 pg/ml) or after (280 +/- 100 pg/ml) treatment, but the increase in PTH, expressed as a percentage of preinfusion values, was greater after treatment (329 +/- 73 vs. 132 +/- 10%, P < 0.05). The decreases in serum PTH during calcium infusions did not differ before (70 +/- 5%) or after (73 +/- 5%) therapy, and the set point for PTH release did not change (1.20 +/- 0.03 vs. 1.23 +/- 0.01 mmol/l, not significant). Calcitriol modifies PTH secretion during hypocalcemia in secondary hyperparathyroidism without affecting the set point for PTH release; although calcitriol lowers serum PTH levels, it may also restore the secretory reserve of hyperplastic parathyroid tissues during hypocalcemia.
Adolescent↗
Lemierre's syndrome: postanginal sepsis due to anaerobic oropharyngeal infection.
Lemierre's syndrome is an uncommon clinical entity. It consists of oropharyngeal infection and anaerobic bacteremia, followed by jugular vein septic thrombophlebitis with embolization to lungs and other areas. Although it occurs less frequently than in the pre-antibiotic era, it is important that the typical presentation be recognized because of its lethal potential. A case of Lemierre's syndrome in Louisville, Kentucky, is described.
Adolescent↗
Antibody response to Plasmodium vivax antigens in human malaria.
The present study investigated the serum antibody response to parasite antigens involved in human Plasmodium vivax malaria. Analysis was performed by protein immunoblotting of a pool of P. vivax preparations obtained from blood of patients from Tapachula, Chiapas (southeastern Mexico), and sera from local malarious patients. Patient sera recognized 19 P. vivax antigens with molecular sizes between 17 and 170 kD. The most frequently recognized antigens were proteins of 19, 31, 43, 72, 93, and 97 kD. These proteins could be useful in diagnostic methods and possibly relevant in vaccine design.
Adolescent↗
Antigenic characterization of Plasmodium vivax with monoclonal antibodies.
Monoclonal antibodies were produced against Plasmodium vivax obtained from patients living in southeastern Mexico, where P. vivax malaria is endemic. Nine hybridomas specific for this parasite were obtained. By an indirect immunofluorescence assay, seven antibodies were found to react with epitopes present in the cytoplasm of the infected erythrocyte and two with the parasite itself. By immunoblotting, five monoclonal antibodies reacted with a 17-kD protein band, three with an 85-kD band, and two with one of 45 kD. By immunogold electron microscopy, two antibodies that reacted with the cytoplasm of infected erythrocytes by immunofluorescence also labeled cytoplasmic clefts, and one, in addition, recognized caveola-vesicle complexes and the parasite matrix. These results demonstrate the value of monoclonal antibodies in identifying P. vivax antigens and disclosing their subcellular distribution.
Animals↗
The choice of empirical antibiotic therapy for nosocomial pneumonia.
Nosocomial pneumonia has the highest crude mortality rate of all hospital-acquired infections. The choice of empirical antibiotic therapy can be based on in vitro sensitivities of sputum bacterial isolates. Organisms recovered from purulent sputum of 500 intensive care unit (ICU) patients from five hospitals in Louisville, Kentucky, had antibiotic sensitivities measured by microbroth dilution. The most common isolates were Staphylococcus aureus (26.6%), Pseudomonas species (24.8%), Enterobacter species (11.8%), Escherichia coli (7.2%), Klebsiella species (7.0%), Streptococcus species (4.4%) and Serratia species (4.0%). These organisms were tested for susceptibility to amikacin, ciprofloxacin, imipenem/cilastatin, ticarcillin/clavulanate, piperacillin, ceftriaxone and ceftazidime. The antibiotics effective against more than 80% of the seven most common isolates included amikacin (97%), imipenem (94%), ciprofloxacin (92%) and ticarcillin/clavulanate (84%). These sensitivity patterns may serve as a guide to choosing empirical antibiotics for ICU-acquired pneumonia in Louisville. When the use of a beta-lactam antibiotic alone or in combination with an aminoglycoside is preferred, imipenem or ticarcillin-clavulanate may be considered the antibiotics of choice. Studies are in progress to delineate the clinical use of ciprofloxacin alone or in combination with beta-lactam antibiotics for treating nosocomial pneumonia.
Anti-Bacterial Agents↗
Acute miliary blastomycosis in an AIDS patient.
The incidence of blastomycosis in immunocompromised patients with HIV infection is very low when compared to other mycoses. Of the 19 cases of blastomycosis described in HIV-infected patients, only four had a miliary pattern on chest x-ray. A case of acute miliary blastomycosis in an HIV infected patient from Louisville is described.
Acquired Immunodeficiency Syndrome↗
Rapid tests for the diagnosis of Legionella infections.
Three rapid tests are now available for the diagnosis of Legionella infections: direct fluorescent antibody (DFA) assay, culture on selective media, and urinary antigen detection. A combination of the three tests constitutes a "Legionella Panel." The objective of this article is to present our experience with these assays and to discuss experimental tests that may further improve our capability to diagnose Legionnaires' disease. Diagnoses of Legionella infections were done in 11 of 549 Legionella panels submitted to our reference laboratory. Six were positive for urinary antigen with corresponding negative DFA and culture; three had a positive DFA with negative culture and urinary antigen; and two had positive reactions for all three tests. The use of the Legionella panel offers a rapid, sensitive, and specific diagnosis of infection. The amplification of Legionella DNA in respiratory samples by the polymerase chain reaction method is a new diagnostic test that will further improve our ability to recognize and treat patients with Legionella infections.
Antigens, Bacterial↗
Disodium ethylenediaminetetraacetate: adverse effects in dialyzed children.
The present report describes untoward effects of disodium ethylenediaminetetraacetate (EDTA) in three of six pediatric patients treated with continuous cycling peritoneal dialysis, in whom this agent was infused intravenously to lower serum ionized calcium levels during dynamic testing of parathyroid gland function. Patients developed an influenza-like syndrome characterized by fever rhinorrhea, cough, sneezing, and lacrimation. All symptoms disappeared within 24 h. A similar degree of hypocalcemia was induced with sodium citrate, an alternative hypocalcemic agent, in the same patients without side effects. Sodium citrate, rather than EDTA, should be used to induce hypocalcemia when assessing parathyroid gland dynamics in children with end-stage renal disease.
Adolescent↗
Comparative study of the bactericidal activity of ampicillin/sulbactam and erythromycin against intracellular Legionella pneumophila.
Intracellular bactericidal activity of ampicillin/sulbactam and erythromycin was determined with a human macrophage-like (U-937) cell line infected with Legionella pneumophila. Cell monolayers inoculated with L. pneumophila were treated with erythromycin, ampicillin, sulbactam, or ampicillin/sulbactam during the logarithmic phase of bacterial growth. Intracellular bacterial counts were determined at 2-h intervals for 8 h from the time that antibiotics were added. The number of viable intracellular bacteria increased during this time by 0.9 x log10 cfu/mL (P < 0.05) in the control culture, did not change significantly in the cultures treated with ampicillin or sulbactam, decreased by 0.8 x log10 cfu/mL (P < 0.05) with erythromycin, and decreased by 1.8 x log10 cfu/mL with ampicillin/sulbactam (P < 0.05). The number of cfu/mL was significantly less after incubation with ampicillin/sulbactam than with erythromycin (P < 0.05). Ampicillin/sulbactam appeared to have greater bactericidal activity against intracellular L. pneumophila than erythromycin in this in-vitro model. The bactericidal action of ampicillin/sulbactam was significantly greater than would be expected from the additive effects of ampicillin plus sulbactam, suggesting synergic bactericidal activity.
Ampicillin↗
Recent advances in the management of renal osteodystrophy in children.
Secondary hyperparathyroidism remains the predominant histologic lesion in pediatric patients undergoing regular dialysis, but recent evidence indicates that the regulation of parathyroid hormone secretion by calcium does not differ substantially between patients with osteitis fibrosa and subjects with normal renal function. Growth retardation and skeletal deformities are major findings in pediatric patients with renal osteodystrophy, and alterations in vitamin D metabolism and insulin-like growth factor almost certainly contribute to these findings. Avoidance of aluminum-containing medications and the introduction of intermittent calcitriol therapy provide newer approaches to the effective management of secondary hyperparathyroidism in pediatric patients with end-stage renal disease.
Child↗
Direct in vivo comparison of calcium-regulated parathyroid hormone secretion in normal volunteers and patients with secondary hyperparathyroidism.
The regulation of PTH secretion by calcium is altered in patients with primary hyperparathyroidism. A similar disturbance may occur in secondary hyperparathyroidism, but direct in vivo comparisons of PTH secretion in normal subjects and those with secondary hyperparathyroidism have not been made. Thus, 13 patients with end-stage renal failure and secondary hyperparathyroidism and 20 healthy volunteers underwent dynamic tests of PTH secretion. Changes in ionized calcium were induced by 2-h iv infusions of calcium gluconate or sodium citrate on consecutive days, and the sigmoidal relationship between serum ionized calcium and PTH levels was examined. During sodium citrate infusions, serum ionized calcium levels decreased by 0.21 +/- 0.04 and 0.20 +/- 0.05 mmol/L, respectively (mean +/- SD), in normal volunteers and dialyzed patients (P = NS). Serum PTH levels rose from 27 +/- 7 to 107 +/- 33 pg/mL in controls and from 480 +/- 238 to 859 +/- 412 pg/mL in dialyzed subjects; thus, maximum PTH levels were 396% of preinfusion values in normal subjects, but only 79% greater than baseline values in dialyzed patients (P < 0.001). During the first 30 min of calcium infusions, the increase in serum ionized calcium did not differ between groups, but PTH levels fell more rapidly in normal volunteers; values were 24% of preinfusion levels in controls, but only 56% of the baseline in dialyzed patients (P < 0.01) after 30 min. Minimum PTH levels were attained after 50 min of calcium infusion in normal volunteers and after 70 min in dialyzed patients. The derived values for set-point were 1.21 +/- 0.04 and 1.24 +/- 0.06 mmol/L, respectively, in control and dialyzed subjects (P = NS). These results do not support the contention that the set-point for calcium-regulated PTH secretion is greater than normal in patients with secondary hyperparathyroidism due to end-stage renal disease.
Adolescent↗
[Toxic cardiomyopathy due to cocaine use].
The clinical record of 5 patients are studied. They were hospitalized in Santo Tomás Hospital with history of chronic and massive intoxication with inhaled and ingested cocaine. They all had cardiomegaly: in one, of grade I; in three, of grade III. The echocardiography mode B showed global cardiomegaly with dilatation of cavities and ejection fraction of 20% or below.
Adult↗
Killing of Legionella pneumophila by nitric oxide in gamma-interferon-activated macrophages.
The role of nitric oxide (NO) radicals in killing the intracellular bacterial pathogen Legionella pneumophila (Lp) was examined in infected macrophages. Murine (RAW 264.7) and human (HL-60) cell monolayers were treated with 100 U/ml gamma-interferon (IFN) and cocultured with Lp in the presence and absence of NGMMA, a specific inhibitor of NO production. Viable Lp in IFN-treated RAW 264.7 cells decreased from 3.8 to 0.7 +/- 0.12 log CFU/ml after 24 h incubation, whereas in IFN+NGMMA-treated RAW 264.7 cells, viable Lp persisted at 2.2 +/- 0.2 log CFU/ml after 24 h. This increased survival corresponded with an inhibition of NO production (5.65 +/- 2.99 microM with NGMMA vs. 58.6 +/- 5.36 microM without NGMMA). Viable Lp were susceptible to killing, in a dose-dependent fashion, by 0, 2.5, and 5.0 mM sodium nitroprusside, a source of NO radicals. IFN-treated RAW 264.7 cells also had significantly decreased levels of intracellular iron (below assay limit) when compared to IFN+NGMMA-treated cells (72.0 +/- 0.78% of control). Normally permissive HL-60 cells treated with IFN were bacteriostatic rather than bactericidal, and NO production was not detected above background. Thus, NO radicals play a critical role in the bactericidal activity against Lp by IFN-treated RAW 264.7 cells, but the absence of NO production limits IFN-treated HL-60 cells to bacteriostasis.
Animals↗
Amplitude analysis of stress technetium-99m methoxy isobutylisonitrile images in coronary artery disease.
To determine the role of rest and stress gated technetium-99m methoxyisobutylisonitrile (sestamibi), in the detection of coronary artery disease, routine Fourier analysis of these images was performed with the best septal left anterior oblique (LAO) position of 20 patients (17 men, 3 women; aged 40-75 years) who also underwent rest or redistribution/stress single photon emission tomography (SPET) (99mTc-sestamibi and Thallium-201), gated blood pool imaging and coronary angiogram. There were 6 patients with single-vessel disease, 6 with two-vessel disease, 4 with three-vessel disease, 2 with coronary spasms, 1 with a patent graft and 1 with anginal episodes but a normal angiogram result. Three normal volunteers (2 women, 1 man; aged 24-26 years) also had rest and stress gated blood pool as well as rest and stress gated 99mTc-sestamibi imaging. Rest and stress 99mTc-sestamibi amplitude and phase images depicted regional myocardial wall shortening from the outer layer of the myocardium to the center of the left ventricle as follows: a high amplitude halo of maximal negative count rate variation; a circular thinner halo of negligible amplitude; a central region of maximal positive count rate variation, as the images evolved from end-diastole to end-systole. Similar patterns with regional differences represented abnormal myocardial wall shortening. 99mTc-sestamibi and 201Tl SPET images were in agreement in 90% of the patients and 92% of myocardial regions. 201Tl SPET detected 83% of angiographically proven lesions, as compared with 80% for 99mTc-setamibi SPET and 80% for the amplitude images. The amplitude images demonstrated a larger number of other abnormalities not predicted on the angiogram, probably because they were able to detect regions with a potential for flow improvement and transient regional wall shortening abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗