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C Diaz

Publications and source records attributed to C Diaz.

At least 19 recordsLinked to original sources
PubMed2003

Bone mass and bone modelling markers in hypertensive postmenopausal women.

Numerous phosphocalcium alterations associated with bone mineral density in hypertension have been described, but very few studies assess them. This study assesses bone mass in hypertensive postmenopausal women and the hypertension influence determining both calcium homeostasis and bone turnover markers. Blood and urine samples were analysed for calcium metabolism-related parameters. Densitometry studies were conducted in the lumbar spine (L2-L4). Hypertensive osteoporotic women--selected from 82 women, with 22% osteoporosis prevalence, similar to the rate for the same age in the Spanish population--had significantly higher levels of body mass index (29+/-4 vs 26+/-4, P=0.019), calciuria (293+/-146 vs 210+/-116 mg/24 h, P=0.023) and calcium/creatinine ratio (0.33+/-0.2 vs 0.22+/-0.1 P=0.003) vs hypertensive nonosteoporotic women. No relation was found between systolic and diastolic blood pressure with bone mass. However, there was a negative osteocalcin correlation (r=-0.386, P=0.0001, and r=-0.242, P=0.033). Calciuria is associated with bone mass decrease in hypertensive women, and there is no relation between bone mass and blood pressure.

Adult↗
PubMed2002

Spontaneous resolution of recurrent tonsillitis in pediatric patients on the surgical waiting list.

OBJECTIVE: To assess the impact of the waiting list on the spontaneous resolution of recurrent acute tonsillitis in children. METHODS: We have evaluated 623 cases placed on the waiting list for elective tonsillectomy (with or without adenoidectomy) between February 1994 and May 1999 at our institution. In each child, age, time on the waiting list, type of procedure and outcome were registered. There were two possible outcomes after the preoperative evaluation: tonsillectomy was still indicated or tonsillectomy was not necessary. RESULTS: Mean length of time on the waiting list was 10.8 months (range: 3.0-35.6 months; median: 8.2 months). In 507 of the 623 children (81.4%), the operation was still indicated. However, 116 patients (18.6%) did not need surgery because of spontaneous resolution of the clinical picture. No relation was found between outcome and age, time on the waiting list or type of procedure (P>0.05). CONCLUSION: There was no clinical evidence for claiming that resolution of recurrent acute tonsillitis in children is spontaneous with time.

Child↗
PubMed2002

[Basic principles of skin biopsy].

Skin biopsies are easy to perform, can be done under direct visual control, allow precise clinico-pathological correlation, and, accordingly, the significance of skin biopsies is very high. This review discusses the basic principles of the interpretation of skin biopsies and alerts to problems that may result from the absence of representative changes of a pathological process in the tissue sections, poor processing of tissue, incorrect assessment of histopathology findings, and shortcomings in the clinico-histopathological correlation.

Biopsy↗
PubMed2002

Operative fetoscopy via telesurgery.

We describe a case in which telesurgical consultation from Tampa, Florida, USA was used to accomplish operative fetoscopy in Santiago, Chile for the treatment of a twin pregnancy involving an acardiac twin. The procedure was successful and a healthy infant was delivered at 37.5 weeks. Operative fetoscopy, a surgical approach to correct birth defects in utero via combined ultrasound and endoscopy, is only available in a handful of centers worldwide. Telesurgery makes use of telecommunication to allow a surgeon at a primary operating site to consult with another experienced surgeon for complex surgical cases. This case illustrates the potential for ultrasound and telesurgery to expand the horizons of operative fetoscopy.

Adult↗
PubMed2001

Synthesis, characterization, and magnetic properties of self-assembled compounds based on discrete homotrinuclear complexes of Cu(II).

Three new supramolecular entities of Cu(II) were synthesized and characterized: [(Cu(H(2)O)(tmen))(2)(mu-Cu(H(2)O)(opba))](2)[(ClO(4))(2)](2).2H(2)O (1), [(Cu(H(2)O)(tmen))(2) (mu-Cu(H(2)O) (Me(2)pba))](2)[(ClO(4))(2)](2) (2), and [(Cu(H(2)O)(tmen))(Cu(tmen))(mu-Cu(OHpba))](n)() ((ClO(4))(2))(n)().nH(2)O (3), where opba = o-phenylenbis(oxamato), Me(2)pba = 2,2-dimethyl-1,3-propylenbis(oxamato), OHpba = 2-hydroxy-1,3-propylenbis(oxamato), and tmen = N,N,N'N'-tetramethylethylenediamine. The crystal structures of 1, 2, and 3 were solved. Complex 1 crystallizes in the monoclinic system, space group C2/c with a = 20.572(4) A, b = 17.279(6) A, c = 22.023(19) A, beta = 103.13(4) degrees, and Z = 8. Complex 2 crystallizes in the monoclinic system, space group P2(1)/c, with a = 16.7555(7) A, b = 13.5173(5) A, c = 17.1240(7) A, beta = 104.9840(10) degrees, and Z = 4. Complex 3 crystallizes in the orthorhombic system, space group Pca2(1) with a = 21.2859(4) A, b = 12.8286(10) A, c = 12.6456(2) A, and Z = 4. The three complexes are very similar in structure: a trinuclear Cu(II) complex with the two terminal Cu(II) ions blocked by N,N,N',N'-tetramethylethylenediamine, but with a different environment in the Cu(II) central ion. In the case of complex 1, two of these trinuclear entities are packed with a short distance between the central Cu(II) ions of two separate entities forming a hexanuclear-type compound. In the case of 2, two of these trinuclear entities are linked by a hydrogen bond between a water molecule of one terminal Cu(II) and one oxygen atom of the oxamato ligand of the neighboring entity, also forming a hexanuclear complex. In the case of complex 3, the intermolecular linkages give a one-dimensional system where the OH groups of the OHpba entities are linked to the terminal Cu(II) of the neighboring entities. The magnetic properties of the three complexes were studied by susceptibility measurements vs temperature. For complex 1, an intramolecular J value of -312.1 cm(-)(1) and a contact dipolar interaction of -0.44K were found. For complex 2 and 3 the fit was made by the irreducible tensor operator formalism (ITO). The values obtained were as follows: J(1) = -333.9 cm(-)(1) and J(2) = 0.67 cm(-)(1) for 2 and J(1) = -335.9 cm(-)(1) and J(2) = 3.5 cm(-)(1) for 3.

Journal Article↗
PubMed2001

Juvenile xanthogranuloma as a sequel to Langerhans cell histiocytosis: a report of three cases.

We report three children who had multisystem Langerhans cell histiocytosis (LCH) with cutaneous involvement and subsequently developed juvenile xanthogranuloma (JXG). JXG appeared 3--6 years after the initial manifestation of LCH. JXG lesions, which presented as yellowish papules, revealed typical Touton giant cells and were factor XIIIa positive but S100 and CD1a negative. Non-LCH histiocyte disorders, such as JXG, are known to occur as a reaction to a variety of external stimuli such as infection and trauma. It is therefore conceivable that the inflammatory reaction associated with LCH may have precipitated the development of JXG in our patients. Alternatively, one could speculate that this association might be due to a common histogenetic precursor of the cell types involved.

Child↗
PubMed2000

Effects of lipolysis or heat treatment on HIV-1 provirus in breast milk.

BACKGROUND: Transmission of HIV-1 infection through breastfeeding is associated with integrated DNA (provirus) in milk cells. Reduction of HIV-1 DNA in milk may lessen infectivity. PURPOSE: To investigate efficacy of two methods available in developing countries to reduce HIV-1 proviral DNA in breast milk. METHODS: Methods simulated field conditions; milk was heated by bringing it to a boil, for instance, over a cooking fire, and lipolysis was done at room temperature. Four HIV-positive pregnant women were recruited for this pilot study, instructed to feed formula exclusively, and to stimulate milk production using pumping. Milk was collected twice weekly for 3 weeks and analyzed qualitatively for HIV-1 proviral DNA by polymerase chain reaction at three stages: 1) fresh, 2) after standing for 6 hours, and 3) after having been brought to the boiling point. RESULTS: Seventeen samples from 4 mothers were analyzed. Fifteen of 17 fresh samples (88%) had measurable HIV-1 proviral DNA despite all mothers' having had low or undetectable plasma viral loads. Lipolysis (standing at room temperature) for 6 hours did not destroy proviral DNA: 6 of 7 samples (86%) tested positive for DNA after lipolysis. No samples of milk (n = 8) brought to a boil were positive for HIV-1 proviral DNA (p <.0001). CONCLUSIONS: This preliminary evidence suggests that inherent lipolytic activity of fresh breast milk is inadequate for destruction of HIV-1; bringing breast milk to a boil may result in decreased HIV-1 infectivity; and breast milk cell-associated HIV-1 may not reflect plasma viral load. Nutritional value or possible bacterial contamination of milk treated in this manner was not assessed.

Adult↗
PubMed2000

Effect of atorvastatin on endothelium-dependent constrictor factors in dyslipidemic rabbits.

Relaxations to acetylcholine and contractions to acetylcholine in the presence of the nitric oxide (NO) synthesis inhibitor (L-N(G)-nitroarginine methyl ester, L-NAME) were studied in aortic rings from rabbits fed either a control or a diet containing 0.5% cholesterol+14% coconut oil for 14 weeks and treated or not with atorvastatin (2.5 mg kg(-1) day(-1)). Rings were incubated with the endothelin (ET(A)) receptor antagonist BQ123, and/or the thromboxane A(2) (TXA(2))/prostaglandin H(2) (PGH(2)) receptor antagonist ifetroban. In rabbits, high cholesterol and triglyceride plasma levels were associated with intimal thickening and blunted acetylcholine-relaxation as compared with controls. By contrast, acetylcholine+L-NAME response was higher. Incubation with either ifetroban or BQ123 increased acetylcholine-relaxation in both diet groups and it reduced the constrictor response only in dyslipidemic rabbits. Removal of endothelium reduced acetylcholine+L-NAME contraction in dyslipidemic rabbits, although increased it in control animals. Atorvastatin treatment reduced plasma lipid levels and lesion size in dyslipidemic animals. Likewise, it prevented acetylcholine-relaxation reduction. In addition, atorvastatin reduced constrictor response in dyslipidemic rabbits but only in rings with endothelium. Incubation with either ifetroban or BQ123 did not further modify these responses in atorvastatin-treated animals in any group. These data suggest that ET and TXA(2) availabilities seem to participate in the endothelial dysfunction associated with dyslipidemia. Atorvastatin treatment reduces intimal thickening and improves endothelial dysfunction in rabbits. This effect seems to be a consequence of its ability to act on ET and TXA(2) systems.

Animals↗
PubMed2000

Allelic variants of the thiopurine S-methyltransferase deficiency in patients with ulcerative colitis and in healthy controls.

OBJECTIVE: Thiopurine S-methyltransferase (TPMT) is a cytosolic enzyme that catalyzes the inactivation of mercaptopurine, azathioprine, and thioguanine. The genetic polymorphisms in the TPMT gene that regulate TPMT activity are inherited as an autosomal recessive trait and patients with genetically determined low levels of TPMT activity develop severe myelosuppression when treated with standard doses of the above-mentioned drugs. We have analyzed the frequencies of the allelic variants of the TPMT gene in a white European population of healthy blood donors from Spain and The Netherlands, and in a group of patients suffering from ulcerative colitis (UC) with a similar genetic background. METHODS: Two hundred and thirteen unrelated healthy individuals (HC) and 146 UC patients were typed for the polymorphic sites at positions 460 (G-->A) and 719 (A-->G) of the TPMT gene using specific polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) methods. RESULTS: There were no significant differences between the allele frequencies observed in the group of UC patients and those of the control group (10% of cases were heterozygous carriers of a TPMT mutant allele). The most frequent mutant allele in both UC and HC groups was TPMT3A (A460-->G719) (60% of carriers). TPMT3B (A460-->A719) and TPMT3C (G460-->G719) alleles were more often found in our study than in previously reported studies, reflecting the different genetic backgrounds of the European populations analyzed. CONCLUSIONS: Genotyping methods provide a simple and reliable screening to identify patients with a high risk of developing severe bone marrow toxicity if treated with thiopurine drugs. In UC patients, TPMT genotype should be determined before the initiation of azathioprine therapy.

Alleles↗
PubMed2000

Maternal and infant factors predicting disease progression in human immunodeficiency virus type 1-infected infants. Women and Infants Transmission Study Group.

BACKGROUND: Infants with perinatally acquired human immunodeficiency virus type 1 (HIV-1) infection have widely variable courses. Previous studies showed that a number of maternal and infant factors, when analyzed separately, are associated with infant HIV-1 disease progression. In this study, clincal, virologic, and immunologic characteristics in the mothers and infants were examined together to determine the predictors of disease progression by 18 months of age and the associations with rapid progression during the first 6 months of life. METHODS: One hundred twenty-two HIV-1-infected women whose infants were HIV-1 infected were identified from the Women and Infants Transmission Study (WITS) cohort. WITS is a longitudinal natural history study of perinatal HIV-1 infection carried out in 6 sites in the continental United States and in Puerto Rico. The women were enrolled during pregnancy and their infants were enrolled at the time of delivery and followed prospectively by a standardized protocol. Virologic and immunologic studies were performed in laboratories certified by National Institutes of Health-sponsored quality assurance programs. Maternal factors in pregnancy were used as potential predictors of infant disease progression (progression to Centers for Disease Control and Prevention [CDC] Clinical Class C disease or death by 18 months of age) or as correlates of progression at <6 months of age. Infant factors defined during the first 6 months of life were used as potential predictors of progression during 6 to 18 months of age and as correlates of progression at <6 months of age. RESULTS: Progression by 18 months of age occurred in 32% of infants and by 6 months of age in 15%. Maternal characteristics that, by univariate analysis, were significant predictors of infant disease progression by 18 months of age were elevated viral load, depressed CD4(+)%, and depressed vitamin A. CD8(+)%, CD8(+) activation markers, zidovudine (ZDV) use, hard drug use, and gestational age at delivery were not. When examined in a combined multivariate analysis of maternal characteristics, only vitamin A concentration independently predicted infant progression. Infant characteristics during the first 6 months of life that, by univariate analysis, were associated with disease progression included elevated mean viral load at 1 to 6 months of age, depressed CD4(+)%, CDC Clinical Disease Category B, and growth delay. Early HIV-1 culture positivity (<48 hours), CD8(+)%, CD8(+) activation markers, and ZDV use during the first month of life did not predict progression. Multivariate analysis of infant characteristics showed that the only independent predictors were progression to CDC Category B by 6 months of age (odds ratio [OR], 5.80) and mean viral load from 1 to 6 months of age (OR, 1.99). The final combined maternal and infant analysis included the significant maternal and infant characteristics in a multivariate analysis. It showed that factors independently predicting infant progression by 18 months of age were progression to CDC Category B by 6 months of age (OR, 5.80) and elevated mean HIV-1 RNA copy number at 1 to 6 months of age (OR, 1.99). The characteristics associated with rapid progression to CDC Category C disease or death by 6 months of age were also examined. The only maternal characteristic associated with progression by 6 months in multivariate analysis was low maternal CD4(+)%. The infant characteristics associated with progression by 6 months of age in multivariate analysis were depressed mean CD4(+)% from birth through 2 months and the presence of lymphadenopathy, hepatomegaly, or splenomegaly by 3 months. Infant ZDV use was not assocciated with rapid progression. CONCLUSION: The strongest predictors of progression by 18 months are the presence of moderate clinical symptoms and elevated RNA copy number in the infants in the first 6 months of life. In contrast, progression by 6 months is associated with maternal and infant immun

Analysis of Variance↗
PubMed2000

Early cognitive and motor development among infants born to women infected with human immunodeficiency virus. Women and Infants Transmission Study Group.

OBJECTIVE: To examine the frequency, timing, and factors associated with abnormal cognitive and motor development during the first 30 months of life in infants born to women infected with human immunodeficiency virus type 1 (HIV-1). METHODS: Serial neurodevelopmental assessment was performed with 595 infants born to women infected with HIV-1 in a multicenter, prospective, natural history cohort study. Survival analysis methods were used to evaluate 6 outcome events related to abnormal cognitive and motor growth (time to confirmed drop of 1 SD, time to first score <69, and time to confirmed drop of 2 SD) in Bayley Scales of Infant Development Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI) scores among infected (n = 114) and uninfected (n = 481) infants. Proportional hazards modeling was used to evaluate the effects of HIV infection status, prematurity, prenatal exposure to illicit drugs, maternal educational attainment, and primary language. RESULTS: HIV-1 infection was significantly associated with increased risk for all outcome events related to abnormal mental and motor growth. Differences between infected and uninfected infants were apparent by 4 months of age. Prematurity was associated with increased risk for MDI <69 and PDI <69. Maternal education of <9 completed years was associated with increased risk for MDI <69. Neither prenatal exposure to illicit drugs nor primary language other than English was associated with abnormal development. CONCLUSION: A significant proportion of infants with HIV-1 infection show early and marked cognitive and motor delays or declines that may be important early indicators of HIV disease progression. These abnormalities are independent of other risk factors for developmental delay.

Adolescent↗
PubMed2000

Intracellular studies of the nucleoside reverse transcriptase inhibitor active metabolites: a review.

Nucleoside reverse transcriptase inhibitors (NRTIs) plasma concentrations do not correlate with clinical efficacy or toxicity. These agents need to be phosphorylated to become active against HIV-infection. Thus, the characterization of the NRTIs intracellular metabolite pharmacological parameters will provide a better understanding that could lead to the development of more rational dose regimens in the HIV-infected population. Furthermore, intracellular measurements of NRTIs may provide a better marker with respect to clinical efficacy and toxicity than plasma concentrations. Thus, in this article we review the latest information regarding the intracellular pharmacological parameters of zidovudine (ZDV) and lamivudine (3TC) active metabolites in HIV-infected patients including the results from our recent clinical studies. We will start the discussion with ZDV and 3TC clinical efficacy, followed by systemic pharmacokinetics studies. We will then discuss the in vitro and in vivo intracellular studies with particular emphasis in the method development to measure these metabolites and we will conclude with the most current data from our clinical trials.

Adult↗
PubMed2000

Impaired eosinophil recruitment to the cornea in P-selectin-deficient mice in Onchocerca volvulus keratitis (River blindness).

PURPOSE: A murine model of helminth-induced keratitis (river blindness) that is characterized by a biphasic recruitment of neutrophils (days 1-3) and eosinophils (days 3+) to the cornea has been developed. The purpose of this study was to determine the relative contribution of P- and E-selectin in recruitment of these inflammatory cells from limbal vessels to the corneal stroma. METHODS: P- and E-selectin gene knockout (-/-) mice were immunized with antigens extracted from the parasitic helminth Onchocerca volvulus. One week after the last immunization, parasite antigens were injected directly into the corneal stroma. Mice were killed on days 1 and 3 postchallenge, and eyes were immunostained with either anti-eosinophil major basic protein (MBP) or with anti-neutrophil Ab. The number of cells in the cornea was determined by direct counting. RESULTS: Recruitment of eosinophils to the cornea was significantly impaired in P-selectin(-/-) mice (63.9% fewer eosinophils on day 1 [P: = 0.0015], and 61% fewer on day 3 [P: < 0.0001]) compared with control C57BL/6 mice. In contrast, P-selectin deficiency had no effect on neutrophil recruitment to the cornea. There was no inhibition of eosinophil and neutrophil migration to the corneas of E-selectin(-/-) mice, indicating that there is no direct role for this adhesion molecule in helminth-induced keratitis. CONCLUSIONS: The present study demonstrates that P-selectin is an important mediator of eosinophil recruitment to the cornea. P-selectin interactions may therefore be potential targets for immunotherapy in eosinophil-mediated ocular inflammation.

Animals↗
PubMed1999

Obstetric and newborn outcomes in a cohort of HIV-infected pregnant women: a report of the women and infants transmission study.

OBJECTIVE: To determine obstetric and neonatal outcomes in a cohort of HIV-infected pregnant women and to assess whether HIV-related immunosuppression increases the risk of adverse outcomes of pregnancy. METHODS: Between 1989 and 1994, interview, physical examination, laboratory, and medical record data were prospectively collected from HIV-infected pregnant women and on their newborns. Factors associated with adverse pregnancy outcome and HIV disease status were correlated with pregnancy outcome using logistic regression analysis. RESULTS: 634 women delivered after 24 weeks of gestation. Preterm birth, low birth weight, and small-for-gestational-age neonates occurred in 20.5%, 18.9%, and 24.0% of pregnancies, respectively. Factors associated with low birth weight were CD4 percentage <14%, history of adverse pregnancy outcome, pediatric HIV infection, bleeding during pregnancy, and Trichomonas infection. Preterm birth was associated with CD4 percentage <14%, a history of adverse pregnancy outcome, and bleeding during pregnancy. Being small for gestational age was associated with maternal hard drug use during pregnancy, Trichomonas infection, history of adverse pregnancy outcome, and hypertension. CONCLUSIONS: Adverse pregnancy outcomes are common for HIV-infected women and are associated with low maternal CD4 percentage and pediatric HIV infection. Preterm birth, low birth weight, and small-for-gestational-age ranking, however, are also associated with previously recognized sociodemographic and obstetric factors that are not unique to HIV infection.

Adult↗
PubMed1999

Lack of long-term effects of in utero exposure to zidovudine among uninfected children born to HIV-infected women. Pediatric AIDS Clinical Trials Group Protocol 219/076 Teams.

CONTEXT: With the success of zidovudine chemoprophylaxis for prevention of perinatal transmission of the human immunodeficiency virus (HIV), an increasing number of HIV-exposed but uninfected children will have in utero exposure to zidovudine and other antiretroviral drugs. OBJECTIVE: To evaluate the long-term effects of in utero exposure to zidovudine vs placebo among a randomized cohort of uninfected children. DESIGN: Prospective cohort study based on data collected during Pediatric AIDS Clinical Trials Group Protocol 076, a perinatal zidovudine HIV prevention trial, and Protocol 219, a long-term observational protocol. SETTING: Pediatric research clinics in the United States. PATIENTS: Two hundred thirty-four uninfected children born to 230 HIV-infected women enrolled in Protocol 076 and followed up through February 28, 1997, in Protocol 219 (122 in the zidovudine group and 112 in the placebo group). MAIN OUTCOME MEASURES: Physical growth measurements, immunologic parameters, cognitive/developmental function, occurrence of neoplasms, and mortality data assessed every 6 months for children younger than 24 months and yearly thereafter or as clinically indicated. Baseline echocardiogram and funduscopic evaluations were collected before 36 months of age. RESULTS: Median age of children at time of last follow-up visit was 4.2 years (range, 3.2-5.6 years). There were no significant differences between children exposed to zidovudine and those who received placebo in terms of sequential data on lymphocyte subsets; weight, height, and head circumference z scores; and cognitive/developmental function. No deaths or malignancies occurred. Two children (both exposed to zidovudine) are being followed up for abnormal, unexplained ophthalmic findings. One child exposed to zidovudine had a mild cardiomyopathy on echocardiogram at the age of 48 months; the child is clinically asymptomatic. CONCLUSIONS: No adverse effects were observed in HIV-uninfected children with in utero and neonatal exposure to zidovudine followed up for as long as 5.6 years. Continued prospective evaluations of children born to HIV-infected women who are exposed to antiretroviral or immunotherapeutic agents are critical to assess the long-term safety of interventions that prevent perinatal HIV transmission.

Anti-HIV Agents↗