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D Figueroa

Publications and source records attributed to D Figueroa.

At least 19 recordsLinked to original sources
PubMed2003

Application of composted urban residue enhanced the performance of afforested shrub species in a degraded semiarid land.

Improvement of physical-chemical soil quality is a key step for carrying out revegetation programs of degraded lands in Mediterranean semiarid areas. Organic residue addition may restore the quality of these areas. A field experiment was conducted in a silt-loam soil (Typic Petrocalcid) from a degraded semiarid Mediterranean area to evaluate the effect of the addition of a composted urban residue on soil aggregate stability, bulk density and chemical properties and on the establishment of Pistacia lentiscus and Retama sphaerocarpa seedlings. The composted residue was applied at a rate of 6.7 kg m(-2) before planting. The nutrient content (NPK), total organic C and water soluble C were increased and bulk density was decreased, in the rhizosphere soil of both shrub species, by the composted residue. The addition of composted residue significantly increased the soil aggregate stability by about 22% for both shrub species. The beneficial effect of the composted residue on soil quality still persisted 18 months after addition. Eighteen months after planting, the addition of composted residue to soil had increased significantly the production of shoot biomass by P. lentiscus and R. sphaerocarpa, by about 160% and 320% respectively, compared to control values. Composted residue addition to soil can be considered an effective preparation method of a degraded area for carrying out successful revegetation programs with Mediterranean shrubs under semiarid conditions.

Conservation of Natural Resources↗
PubMed2001

Identification and characterization of novel mammalian neuropeptide FF-like peptides that attenuate morphine-induced antinociception.

The two mammalian neuropeptides NPFF and NPAF have been shown to have important roles in nociception, anxiety, learning and memory, and cardiovascular reflex. Two receptors (FF1 and FF2) have been molecularly identified for NPFF and NPAF. We have now characterized a novel gene designated NPVF that encodes two neuropeptides highly similar to NPFF. NPVF mRNA was detected specifically in a region between the dorsomedial and ventromedial hypothalamic nuclei. NPVF-derived peptides displayed higher affinity for FF1 than NPFF-derived peptides, but showed poor agonist activity for FF2. Following intracerebral ventricular administration, a NPVF-derived peptide blocked morphine-induced analgesia more potently than NPFF in both acute and inflammatory models of pain. In situ hybridization analysis revealed distinct expression patterns of FF1 and FF2 in the rat central nervous system. FF1 was broadly distributed, with the highest levels found in specific regions of the limbic system and the brainstem where NPVF-producing neurons were shown to project. FF2, in contrast, was mostly expressed in the spinal cord and some regions of the thalamus. These results indicate that the endogenous ligands for FF1 and FF2 are NPVF- and NPFF-derived peptides, respectively, and suggest that the NPVF/FF1 system may be an important part of endogenous anti-opioid mechanism.

Amino Acid Sequence↗
PubMed2000

Effect of El Niño and ambient temperature on hospital admissions for diarrhoeal diseases in Peruvian children.

INTRODUCTION: To investigate whether the El Niño phenomenon and ambient temperature had an effect on the epidemiology of childhood diarrhoea, we analysed data on daily number of admissions of children with diarrhoea to the Oral Rehydration Unit of the Instituto de Salud del Niño in Lima, Peru, between January, 1993, and November, 1998. METHODS: We obtained daily data on hospital admissions from the Oral Rehydration Unit, and meteorological data from the Peruvian Weather Service, and used time-series linear regression models to assess the effects of the 1997-98 El Niño event on admissions for diarrhoea. FINDINGS: 57,331 children under 10 years old were admitted to the unit during the study. During the 1997-98 El Niño episode, mean ambient temperature in Lima increased up to 5 degrees C above normal, and the number of daily admissions for diarrhoea increased to 200% of the previous rate. 6225 excess admissions were attributable to El Niño, and these cost US$277,000. During the period before the El Niño episode, admissions for diarrhoea increased by 8% per 1 degree C increase in mean ambient temperature. The effects of El Niño and ambient temperature on the number of admissions for diarrhoea were greatest during the winter months. INTERPRETATION: El Niño had an effect on hospital admissions greater than that explained by the regular seasonal variability in ambient temperature. The excess increase in ambient temperature was the main environmental variable affecting admissions. If our findings are reproducible in other regions, diarrhoeal diseases may increase by millions of cases worldwide with each degree of increase in ambient temperature above normal.

Child↗
PubMed2000

Lactulose-mannitol intestinal permeability test in children with diarrhea caused by rotavirus and cryptosporidium. Diarrhea Working Group, Peru.

BACKGROUND: The relationship between intestinal permeability and acute secretory diarrheal syndromes caused by rotavirus and Cryptosporidium parvum in infants less than 36 months of age was studied using the lactulose-mannitol excretion assay. METHODS: An oral solution containing 0.4 g/kg lactulose and 0.1 g/kg mannitol was administered to 15 infants with rotavirus, 7 with Cryptosporidium infection and a control group of 7 with secretory diarrhea admitted to the Oral Rehydration Unit of the National Children's Hospital in Lima, Peru. Urinary sugar excretion was measured using an enzymatic spectrophotometric method. The ratio of urinary excretion of lactulose to mannitol was used to measure intestinal mucosal permeability, with higher ratios indicative of increased intestinal permeability. Infants in all three groups were retested 20 days after the initial test. RESULTS: The (mean +/- SE) lactulose:mannitol (L:M) excretion ratios during the acute phase (day 1) of diarrhea in infants with rotavirus or Cryptosporidium and control infants were 0.67 +/- 0.1, 0.76 +/- 0.16, and 0.26 +/- 0.04, respectively. In the convalescent phase (day 20) the ratios were 0.19 +/- 0.02, 0.28 +/- 0.05, and 0.29 +/- 0.07, respectively. Significant reductions in L:M ratios were noted in rotavirus patients between days 1 and 20 (paired t-test; P < 0.01), Cryptosporidium patients between days 1 and 20 (paired t-test; P < 0.05), and between control subjects on day 1 and rotavirus patients on day 1 and Cryptosporidium patients on day 1 (unpaired t-tests; P < 0.05 for both). There were no significant differences in control subjects between days 1 and 20, control subjects and rotavirus patients on day 20, or control subjects and Cryptosporidium patients on day 20. CONCLUSIONS: The results indicate that increased intestinal permeability caused by rotavirus or cryptosporidium infections in Peruvian infants less than 36 months of age is a significant but reversible phenomenon. The temporal relationship observed in the current study and the contribution of such alterations in intestinal mucosal integrity to the burden of diarrheal disease and the development of malnutrition in developing countries is discussed.

Animals↗
PubMed2000

The MNS blood group antigens, Vr (MNS12) and Mt(a) (MNS14), each arise from an amino acid substitution on glycophorin A.

BACKGROUND AND OBJECTIVES: The antigens, Vr (MNS12) and Mt(a) (MNS14), are low-incidence antigens of the MNS blood group system. The Vr antigen has been found only on the red blood cells (RBCs) of persons of Dutch ancestry whereas the Mt(a) antigen has been found on the RBCs of persons from a wide geographic distribution. The objective of this study was to determine the molecular basis of Vr and Mt(a). MATERIALS AND METHODS: Following RT-PCR amplification of total RNA isolated from one Vr+ person (G488) and one Mt(a+) person (GH), the genes encoding glycophorin A (GYPA) and glycophorin B (GYPB) were cloned and sequenced. To confirm the point mutation observed in the cDNA from G488 (Vr+), GYPA exon 3 was cloned and sequenced from the genomic DNA of G488 and a second unrelated Vr+ person (MU). A restriction fragment length polymorphism (RFLP) assay was used to analyze genomic DNA from 11 Mt(a+) persons (10 unrelated) following PCR amplification of GYPA exon 3. RESULTS: The coding sequence of GYPB was normal in both G488 (Vr+) and GH (Mt(a+)). Sequencing data from GYPA clones derived from G488 showed to full length GYPA sequences: A normal GYPA M allele and a GYPA M allele with a point mutation 197C-->A. Sequencing of GYPA exon 3 from G488 and MU confirmed the point mutation. Sequencing data drom GYPA clones derived from GH showed two full length GYPA sequences: a normal GYPA M allele and a GYPA N allele with a point mutation 230C-->T. RFLP analysis based on the point mutation showed that DNA from 11 Mt(a+) samples were heterozygous for the point mutation. CONCLUSION: The Vr antigen arises from a point mutation 197C-->A on GYPA which is predicted to change serine at position 47 to tyrosine. This change introduces a new alpha-chymotrypsin cleavage site. The Mt(a) antigen arises from a point mutation 230C-->T which is predicted to change threonine at position 58 to isoleucine.

Amino Acid Substitution↗
PubMed1999

Receptor for motilin identified in the human gastrointestinal system.

Motilin is a 22-amino acid peptide hormone expressed throughout the gastrointestinal (GI) tract of humans and other species. It affects gastric motility by stimulating interdigestive antrum and duodenal contractions. A heterotrimeric guanosine triphosphate-binding protein (G protein)-coupled receptor for motilin was isolated from human stomach, and its amino acid sequence was found to be 52 percent identical to the human receptor for growth hormone secretagogues. The macrolide antibiotic erythromycin also interacted with the cloned motilin receptor, providing a molecular basis for its effects on the human GI tract. The motilin receptor is expressed in enteric neurons of the human duodenum and colon. Development of motilin receptor agonists and antagonists may be useful in the treatment of multiple disorders of GI motility.

Alternative Splicing↗
PubMed1999

Enteropathogens and other factors associated with severe disease in children with acute watery diarrhea in Lima, Peru.

To evaluate enteropathogens and other factors associated with severe disease in children with diarrhea, 381 children <5 years of age with diarrhea and moderate to severe dehydration (in-patients) and 381 age-, sex-, and date-of-visit-matched children with mild diarrhea (out-patients) presenting to a hospital in Peru, were studied. Rotavirus was detected in 52% of the in-patients and 35% of the out-patients (odds ratio [OR]=2.3, 95% confidence interval [95% CI]= 1.6-3.2); 95% of the rotaviruses among in-patients were of serotypes G1-G4. The risk of severe diarrhea was particularly great in children who were not exclusively breast-fed in early infancy and who also lacked piped water in their homes (for children with both characteristics OR=6.8, 95% CI=3.6-12.8). The high prevalence of rotavirus and its association with severe diarrhea underscores the need for rotavirus vaccines. Interventions to educate mothers and improve access to safe water should augment the impact of rotavirus vaccines in preventing severe diarrhea.

Animals↗
PubMed1998

Identification of the gene responsible for Best macular dystrophy.

Best macular dystrophy (BMD), also known as vitelliform macular dystrophy (VMD2; OMIM 153700), is an autosomal dominant form of macular degeneration characterized by an abnormal accumulation of lipofuscin within and beneath the retinal pigment epithelium cells. In pursuit of the disease gene, we limited the minimum genetic region by recombination breakpoint analysis and mapped to this region a novel retina-specific gene (VMD2). Genetic mapping data, identification of five independent disease-specific mutations and expression studies provide evidence that mutations within the candidate gene are a cause of BMD. The 3' UTR of the candidate gene contains a region of antisense complementarity to the 3' UTR of the ferritin heavy-chain gene (FTH1), indicating the possibility of antisense interaction between VMD2 and FTH1 transcripts.

Amino Acid Sequence↗
PubMed1997

Lymphotactin is produced by NK cells and attracts both NK cells and T cells in vivo.

Injection of lymphotactin (Lptn) into the peritoneum caused an influx of lymphocytes at 24 h. Phenotypic analysis of the cellular influx showed that a large proportion of these cells were T lymphocytes; however, a large number of NK cells was also present. This effect of murine Lptn (mLptn) was specific since the cellular influx was blocked with a mLptn-specific mAb. Similar results were observed when Lptn was injected s.c. and the tissue was analyzed by immunohistochemistry using an anti-CD3epsilon mAb. Microchemotaxis assays confirmed that murine NK cells respond to mLptn, and also showed human NK clones to be similarly responsive to recombinant human Lptn (rhLptn). Immunohistochemical analysis of IL-2-activated murine NK cells and Northern analysis of human NK clones revealed that these cells also produce Lptn, suggesting that a self-regulatory migration mechanism exists in NK cells. Together these data confirm, in vivo, the lymphocyte specificity of Lptn previously observed in vitro and extend its chemotactic effects to the NK cell lineage. We also investigated the functional consequences of truncating the carboxyl terminus of hLptn. This truncated molecule (which is missing the carboxyl-terminal 22 amino acids of hLptn) had no detectable activity on human PBLs. In addition, while hLptn was found to attract murine splenocytes in vitro, the carboxyl-terminal truncated hLptn was again inactive on murine splenocytes. This observation indicates the presence of structural features in the carboxyl terminus of Lptn that are necessary for its biologic activity.

Amino Acid Sequence↗
PubMed1996

Detection of tube agglutination 37 degrees C-only antibodies by solid-phase red cell adherence.

There are no published data on the detection of tube agglutination (TA) 37 degrees C-only antibodies by solid-phase (SP) red cell adherence assays using anti-IgG-coated indicator red cells. Thirteen examples of TA 37 degrees C-only antibodies were tested by conventional SP methods. Four TA 37 degrees C-only antibodies failed to react by SP. Three were anti- Lea, considered clinically insignificant, and one was anti-E, an antibody of potential clinical significance. The remaining nine TA 37 degrees C-only antibodies reacted by SP, including three anti-c, two anti- D, two anti-E, one anti-N, and one anti-M. The anti-M reacted with indicator red cells that lacked the red cell antigen and failed to react with IgG-coated indicator red cells whose anti-IgG component had been neutralized, indicating the antibody contained an IgG component. Two anti-D and one anti-c continued to react in an SP test using neutralized anti-IgG antigen-positive indicator red cells, i.e., indicator binding independent of antiglobulin, suggesting an IgM nature to these antibodies. Therefore, many TA 37 degrees C-only antibodies can be detected by SP either through detection of an IgG component by the anti-IgG of the indicator red cells, or through IgM crosslinking of antigen-positive indicator red cells to antigen-positive SP reagent red cell membranes.

Journal Article↗
PubMed1994

Effectiveness of two methods of advising mothers on infant feeding and dietetic management of diarrhoea at an outpatient clinic in Peru.

The effectiveness of two educational intervention programmes in promoting infant feeding practices was assessed among mothers of small children attending a hospital's Oral Rehydration Unit in Peru. One group of mothers received 5 min of counselling and a recipe pamphlet. The other group received the same counselling plus a 20-min cooking demonstration. Both interventions had a statistically significant (p < 0.05) impact on maternal knowledge and practices; differences between the impact of the two practices were negligible. After merging both groups into a single sample, it was observed that changes over time were significantly large (p < 0.05). Knowledge rates were 27.6% before the intervention, 73.7% 2 days later and 75% 30 days later. The corresponding figures for practices were 2.6%, 58.3% and 37.5% respectively. We conclude that when place, time and message are adequately chosen, a simple method may be an effective way of good communication. We suggest that a larger implementation trial would be useful before starting larger infant feeding programmes.

Counseling↗
PubMed1989

Intrahepatic cholestasis of pregnancy in twin pregnancies.

To clarify whether the increase in estrogen levels occurring during twin pregnancies (TP) is associated with a greater risk of developing intrahepatic cholestasis of pregnancy (ICP), we followed up 62 consecutive patients with TP and compared them with single pregnancies delivered in our hospital during 1 year. The prevalence of ICP was significantly higher in twin than in single pregnancies (20.9% versus 4.7%, respectively; P less than 0.001). Urinary estriol excretion was also significantly higher in twin compared to single pregnancies, although no quantitative differences were detected in TP with or without ICP. In multiparous patients with a proband TP affected by ICP, the disease recurred only in further TP, emphasizing the important role that estrogens seem to play in the pathogenesis of ICP. In contrast, in multiparous patients with a proband single pregnancy affected by ICP, the disease occurred in 70.5% of their other single pregnancies, suggesting the presence of a metabolic predisposition in these cases. However, in both groups of multiparous women a notable number of single pregnancies were not affected by the disease, supporting the postulate that the pathogenesis of ICP is multifactorial and that some as yet unidentified environmental factor needs to be present in order to develop the disease and also to modulate its expressivity.

Alanine Transaminase↗
PubMed1987

Steatorrhea in patients with intrahepatic cholestasis of pregnancy.

A prospective study was undertaken to evaluate fat malabsorption during intrahepatic cholestasis of pregnancy (ICP), a disease characterized by a mild cholestasis of short duration appearing in otherwise healthy young women. An abnormal fecal fat excretion (mean 15.8 g/24 h, range 6-31 g/24 h) was demonstrated in 10 of 12 patients with the icteric form of ICP and in 2 of 11 patients with pruritus gravidarum. The increased fecal fat excretion was generally asymptomatic, could be detected as early as 3 wk after the clinical onset of ICP, remained stable during the affected pregnancies, and returned to normal from 3 to 9 wk after delivery. Steatorrhea correlated with the severity of ICP, estimated by serum levels of bilirubin, total bile salts, and glutamic pyruvic transaminase. A significant fall in the maternal weight/height index was detected after the onset of ICP, being more intense in patients with steatorrhea than in those without it (to 92.6% +/- 3.0% of initial values versus 96.7% +/- 2.8%, respectively; p less than 0.05). A high risk of premature deliveries and fetal distress was demonstrated in these patients, also correlating with the severity of ICP. No direct relationship could be established between steatorrhea or maternal nutritional impairment and fetal prognosis.

Adolescent↗
PubMed1984

[Scanography in purulent meningitis in newborn infants].

Brain CT scans of 40 neonates with bacterial meningitis showed that the main lesions consisted of obstacles to CSF flow resulting in hydrocephalus during the second month; single or multiple foci of ischaemia of very early onset appearing as hypodense areas sometimes contrast-enhanced, and abscesses consecutive to haematogenous septic necrosis. The organisms responsible for these abscesses usually were Proteus spp., more rarely other enterobacteria. Attention is drawn to the usefulness of CT in detecting the nature and size of lesions which are often clinically silent, except for convulsions.

Brain↗
PubMed1983

[Monotherapy with clobazam in epilepsies in children].

Twenty-five epileptic children were treated with clobazam alone for periods of 10 days to 36 months (mean = 9 months and 16 months for children who responded well). Satisfactory results were obtained in 11 patients and marked improvement with a 75% decrease in the initial frequency of seizures in 6 patients. The seizures recurred after a few weeks in 3 other patients. This preliminary study shows that clobazam is well tolerated and remarkably effective, especially in benign partial epilepsy, even in carbamazepine-resistant cases.

Adolescent↗
PubMedDate not supplied

[Knowledge, opinions, and practices regarding Aedes aegypti].

The active participation of the community is indispensable for reducing Aedes aegypti mosquito populations so causes leading to their growth, actions taken, effects on the health and the people in charge of controlling such mosquitoes are all dealt with in this paper. 210 persons were interviewed from June 25 to 27, 1997. The causes of the growth of the mosquito population were: excessive garbage (59%), dirty waters (58%), open water reservoirs (50%) and lack of fumigation (21%). 40% of interviewed people did not know that these vectors can breed even in clean waters. They mentioned some effects on the health due to the mosquito bites. 51% said that mosquitoes should be jointly controlled by the State and the community but 35% believed that the State should be the sole responsible for this task. These opinions may determine that steps are not properly taken to avoid proliferation of vector and that the activities of the anti-vector program are not really understood since they do not meet the expectations.

Adult↗