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Biomedical subjects

A Flores

Publications and source records attributed to A Flores.

At least 73 records · Page 4Linked to original sources

High Cryptosporidium prevalences in healthy Aymara children from the northern Bolivian Altiplano.

The prevalence of Cryptosporidium infection was determined in four Aymara communities in the Bolivian Altiplano, between the city of La Paz and Lake Titicaca, at an altitude of 3,800-4,200 meters. Single stool specimens were randomly collected from 377 5-19-year-old students, all apparently asymptomatic. The total prevalence (31.6%) is possibly the highest reported among healthy humans (a maximum of 9.8% and 2.0% in coprologic surveys in underdeveloped and developed countries, respectively) and one of the highest even in symptomatic subjects. No significant age and sex differences were observed. Such an infection prevalence is probably related to the poor sanitation conditions, contaminated water supplies, overcrowding, and close contact with domestic animals. Continuous exposure to the parasite could be associated with protection against parasite-related symptoms in the children examined.

Adolescent↗

Development of immunity to Mecistocirrus digitatus (Nematoda: Trichostrongylidae) in calves.

The importance of the third (L3), fourth (L4) and adult stages of Mecistocirrus digitatus in inducing resistance to reinfection was examined. Three groups of 5 calves (A, B, C) were immunized for 2 consecutive days with a daily dose of 20,000 M. digitatus infectious larvae. Group A was treated with ivermectin 7 days post-infection (exposed to L3), group B was treated after 26 days (exposed to L3 and L4) and group C after 60 days (exposed to L3, L4 and adults). Thirty days posttreatment, animals were challenged with 30,000 M. digitatus L3. Five previously uninfected control animals (group D) also received 30,000 L3. All animals were necropsied 75 days post-challenge. Increases in exposure to the immunizing infection resulted in significant increases in the pre-patent period post-challenge; 54 days in the controls, compared with 63, 70 and 72 days for groups A, B and C, respectively. Only adult worms were recovered at necropsy, and the mean number of worms significantly increased with increasing exposure to the immunizing infection: 355 in the controls, compared to 481, 937 and 1174 in groups A, B and C, respectively. No significant changes in worm length were observed. Infection with M. digitatus significantly affects a subsequent challenge infection--stimulation of the immune system by exposure to L3 extends the pre-patent period, and suppression by later stages (L4, adult) leads to higher worm burdens.

Abomasum↗

[Spinal cord compression in non-Hodgkin's lymphoma. A study of 10 patients].

Spinal cord compression is an infrequent event in patients with non-Hodgkin's lymphomas (NHL) and early diagnosis and therapy are required. The main clinical and histologic characteristics as well as the response to therapy in 10 NHL patients with spinal cord compression diagnosed at a single center in a 7-year period are referred. The main initial clinical manifestations were pain in dorsal or lumbar regions (5 cases) and paraparesia or paraplegia (5 patients). Infection by human immunodeficiency virus (HIV) was present in four cases. In 8 patients spinal cord compression was the initial manifestation of NHL. Pathologic diagnosis showed intermediate or high-grade lymphoma in 8 out of 10 cases and immunologic phenotype was B-cell in all cases. Laminectomy followed by radiation therapy and chemotherapy was performed in 4 cases, radiotherapy and chemotherapy in two, isolated chemotherapy in 3 and radiation therapy was administered to the remaining case. Complete response was observed in 4 cases and 6 cases were resistant to treatment. No patient with HIV infection responded to treatment. Six patients had died, median survival time for the whole series being 4 months, and the actuarial probability of survival was 40% at the first year.

Adult↗

Presence of very high prevalence and intensity of infection with Fasciola hepatica among Aymara children from the Northern Bolivian Altiplano.

Coprological studies of school children from four communities in the Northern Bolivian Altiplano were carried out in order to estimate the prevalences and intensities of Fasciola hepatica infection. Single stool specimens were collected at random from 558 school children (308 boys and 250 girls) aged 5-19 years old. Nineteen different parasite species (13 protozoan and six helminths) were detected. Of the children examined, 98.7% (96.5-100%) presented infection with at least one parasite species. The mean prevalence of 27.6% by Fasciola hepatica (range, 5.9-38.2%) was the highest not only with respect to the helminth species found in the Northern Bolivian Altiplano but also among the fasciolosis prevalences reported in children in other parts of the world to date. Prevalences were significantly different among the communities surveyed and was significantly higher in the 9-12 years age group. There were, however, no significant differences between sexes. Among the 154 children presenting F. hepatica eggs in stools, intensities ranged from 24-5064 eggs per gram of faeces (epg), with arithmetic and geometric means of 474 and 201 epg, respectively. Significant differences in mean egg output were detected between communities, sexes and age groups. Individual fasciolosis infections coexisting with other pathogenic parasite species (Entamoeba histolytica and/or E. dispar, Giardia intestinalis, Balantidium coli, Dientamoeba fragilis, Cryptosporidium sp., Hymenolepis nana, Taenia spp., Trichuris trichiura, Ascaris lumbricoides and Enterobius vermicularis) were detected. A significant positive association with F. hepatica was only found in the case of G. intestinalis. This coprological study not only verifies the existence of high prevalences of F. hepatica among humans in the Northern Bolivian Altiplano, but also demonstrates the need to expand the Southern boundaries of this high endemic zone to include the Southeastern region of Lake Titicaca.

Adolescent↗

[Acute myelomonocytic leukemia with eosinophilia and inversion of chromosome 16. Study of 6 cases].

The purpose of this study has been to refer the main clinico-biologic characteristics, the evolution and the response to therapy in 6 patients with acute myelomonocytic leukemia with eosinophilia and inversion of chromosome 16 (AML4Eo inv[16]) belonging to a series of 92 patients with acute myeloblastic leukemia diagnosed in a single hospital between 1987 and 1995. The main clinical manifestations were anemic syndrome and hemorrhage. Anemia and thrombocytopenia were present in all cases, high white blood cell count in 4, monocytosis in 5 and eosinophilia in one. Bone marrow aspirate showed myeloid and monocytic blast infiltration (43-62%), eosinophilia (5-19%) and atypical monocytic precursors (6-18%). Induction therapy consisted in one or two cycles of daunorubicin (or idarubicin), cytosine arabinoside and etoposide, followed by two cycles of consolidation treatment, the first with mitoxanthrone and cytosine arabinoside and the second with amsacrine and cytosine arabinoside. One patient died in the induction phase, while complete remission was obtained in the remaining 5. One patient died during the consolidation therapy. Allogeneic bone marrow transplant (BMT) was performed to one patient and autologous BMT to another. The first patient remains in complete remission (CR) at 68 months from diagnosis, and the second relapsed 12 months after BMT. Another patient relapsed at 13 months from diagnosis and the remaining persists in CR 13 months from diagnosis. Actuarial probabilities of CR duration and survival were 50% at 5 years. The clinico-biologic characteristics and the response to therapy of patients with AML4Eo inv(16) are similar to those referred in other series. There is a high probability of CR attainment and, probably, the relapse rate is lower than that of other subtypes of AML.

Adolescent↗

Improved biocontrol activity of Trichoderma harzianum by over-expression of the proteinase-encoding gene prb1.

Transformation systems developed for Trichoderma spp. were utilized to improve the biocontrol efficiency of the mycoparasitic fungus Trichoderma harzianum by increasing the copy number of the basic proteinase gene prb1. The transformants were stable and carried from two to ten copies of prb1. High levels of expression of prb1 during fungus-fungus interaction were detected when T. harzianum and Rhizoctonia solani were confronted in vitro. In liquid cultures the proteinase was induced by cell walls of R. solani. Under greenhouse conditions, incorporation of T. harzianum transformants into pathogen-infested soil significantly reduced the disease caused by R. solani in cotton plants.

Antibiosis↗

Postviral gastroparesis: presentation, treatment, and outcome.

We describe the clinical features and long-term outcome of 11 children who had persistent gastroparesis after an acute viral illness, eight of whom tested positive for rotavirus. Gastric emptying was delayed in the 10 children evaluated with scintigraphy. Antroduodenal manometry confirmed postprandial antral hypomotility in 10 subjects. All children recovered within 6 to 24 months.

Acute Disease↗

Treatment of childhood Hodgkin's disease with COPP or COPP-ABV (hybrid) without radiotherapy in Nicaragua.

BACKGROUND: Childhood Hodgkin's disease (HD) in low-income countries has been reported to have distinct presenting features, including a high prevalence of the mixed cellularity subtype, which also seems to be associated with poorer prognosis. Further investigations are needed to evaluate these issues. Another controversial aspect of childhood HD is the use of radiotherapy (RT) in its treatment and the growing concern about its serious adverse side effects. In this paper, data on the diagnosis and outcome of children treated without RT in a low-income country (Nicaragua) are reported. PATIENTS AND METHODS: Forty-eight consecutive children aged 0-15 years, diagnosed at 'La Mascota' Hospital of Managua (Nicaragua) from January 1990 to October 1995. entered this study. Follow-up was updated in May 1996. Clinical and histopathological staging was performed according to Ann Arbor and Rye criteria, respectively. Treatment consisted of COPP (six cycles) for stages I or IIA, or COPP-ABV hybrid): eight cycles for stages IIB or III, and ID cycles for stage IV. Total cumulative doses of adriamycin and bleomycin in this protocol are, respectively, 200 and 80 mg:sqm for stages II B or III and 250 and 100 mg/sqm for stage IV. RESULTS: The median age of the 48 patients at diagnosis was seven years, and the mean age was 7.9 years (range 3-15 years). Clinical stages were IA in 5, IIA in 9, IIB in 6, IIIA in 5, IIIB in 14, and IVB in 9. Histopathologically, 25 cases presented with mixed cellularity, 15 with nodular sclerosis, 5 with lymphocytic predominance and 3 with lymphocytic depletion. Four patients did not proceed with treatment and were lost to follow-up. Two patients (stages IIIB and IVB), who never achieved complete remission (CR) during treatment, presented progressive disease at the end of the scheduled chemotherapy. The remaining 42 patients were in complete remission at the end of chemotherapy. Following discontinuation of therapy, one patient (stage IA) was lost to follow-up and two patients with stage IIIB, who were in CR after the second chemotherapy cycle, relapsed 20 and 9 months following the diagnosis. EFS at three years is 100% for the 25 patients with stages I, II, IIIA and 74.9% for the 23 patients with stages IIIB or IV. CONCLUSION: The presenting features found in these patients are similar to those reported from other low-income countries. In our experience, however, the high prevalence of the mixed cellularity subtype was not associated with poorer prognosis. Satisfactory results have been achieved in patients with stages I, II or IIIA HD using COPP or COPP-ABV (hybrid) regimens without RT. The treatment was also well tolerated and can thus be recommended for these patients in low-income countries, where RT facilities may be scarce or unavailable. The use of more aggressive treatment schedules and/or RT on involved fields in front-line treatment may, however, be needed for the more advanced stages IIIB or IV. Large studies with adequate follow-up are needed to evaluate whether, if RT is omitted, higher cumulative doses of more toxic drugs are required and thus compare the long-term toxic effects of different treatment modalities.

Adolescent↗

A population-based coprological study of human fascioliasis in a hyperendemic area of the Bolivian Altiplano.

The community of Chijipata Alta, at an altitude of 3850 m, near the southern coast of Lake Titicaca in the northern Altiplano of Bolivia, was surveyed for human fascioliasis. The global prevalence (66.7%) and intensity (eggs per gram of faeces--epg: range: 24-4440; arithmetic mean: 1001; geometric mean: 390) proved to be the highest known in the world by means of coprological techniques. These results suggest the existence of highly hyperendemic subzones among the large human fascioliasis-endemic zone of the Bolivian northern Altiplano. Despite the decrease in prevalence and intensity from children (75.0%, 24-4440 epg) to adults (41.7%, 144-864 epg), our findings show that in an hyperendemic zone adult subjects either maintain the parasites acquired when young or are newly infected as the consequence of inhabiting a zone of high infection risk.

Adolescent↗

Energy evaluation of eight barley cultivars for poultry: effect of dietary enzyme addition.

Three experiments were conducted to study eight barley cultivars and the effect of enzyme addition on their energy value for poultry. In Experiment 1, the AMEn of a reference barley (Beka cultivar) was calculated by increasing barley concentrations (30, 40, 50, and 60%) that replaced a high protein basal diet. In Experiment 2, eight barley cultivars (four spring and four winter cultivars) replaced the reference barley in the diet with 50% barley inclusion. Two of the winter cultivars were two-rowed and two were six-rowed cultivars. A commercial enzyme was added to these diets to study the effect of enzyme addition. Diets were consumed ad libitum by 27 and 145 21-d-old Arbor Acres broiler chicks, in Experiments 1 and 2, respectively. In Experiment 3, 66 adult roosters were used to determine the TMEn of the eight cultivars used in Experiment 2. Dietary AMEn decreased linearly (P < 0.05) with increasing barley (Beka cultivar) inclusion. Beka barley AMEn was calculated by extrapolation of the linear regression equation be equal to 2,980 kcal/kg DM. Barley energy value was influenced by cultivar (P < 0.001); the spring cultivars showed greater energy value than the winter cultivars (2,963 vs 2,852 kcal AMEn/kg DM; 3,192 vs 2,929 kcal TMEn/kg DM). Two-rowed cultivars showed higher TMEn than six-rowed winter cultivars, although no differences were found for AMEn. The correlation between AMEn and TMEn values of barley was relatively low (r = 0.69); therefore, barley TMEn cannot be extrapolated to AMEn for young chicks. Enzyme addition produced an average increase of 220 kcal/kg DM in barley AMEn (P < 0.001); there was a significant (P < 0.10) interaction between barley cultivar and enzyme supplementation. The increment of barley AMEn caused by enzyme addition was partly explained (47%) by an increase in barley viscosity. This relationship implies that enzyme supplementation significantly improves the feeding value of high as compared to low viscosity barley samples, which involved a decrease in AMEn variation among cultivars for enzyme-supplemented barley. No relationship was found between AMEn of unsupplemented barley cultivars and their chemical composition. Instead, a relationship was detected for enzyme-supplemented barley; therefore two equations were proposed for predicting the AMEn of enzyme-supplemented barley to be used directly in diet formulation.

Animals↗

Patient dose in radiologically guided interventional vascular procedures: conventional versus digital systems.

PURPOSE: To calculate the difference in the patient radiation dose in radiologically guided interventional vascular procedures between conventional and digital systems and to estimate the effective dose and the energy imparted with the digital system. MATERIALS AND METHODS: A total of 318 procedures (in 318 patients) in 15 different examination groups were analyzed. The dose-area product was determined by using a transmission chamber fitted to an x-ray-tube light-beam diaphragm; the effective dose was determined by using software. RESULTS: Urinary and biliary tract procedures showed small differences in the average dose-area product between conventional and digital systems. The dose-area products in the vascular procedures were higher with the digital than with the conventional system. The average effective dose and energy imparted were 0.88 mSv and 129 mJ, respectively, in the subcutaneous placement of a reservoir for analgesic administration and as much as 25.7 mSv and 829 mJ, respectively, in spermatic vein embolization. CONCLUSION: The dose-area product was higher with the digital system than with the conventional system in 13 of the 15 groups. To reduce the patient dose in vascular interventional radiology procedures, the training of personnel and the frequent use of conventional fluoroscopy and low-dose imaging are required.

Adult↗

Acute promyelocytic leukemia in a HIV seropositive patient.

Acute myeloid leukemia (AML) is infrequent in patients with human immunodeficiency virus (HIV) infection. Among AML, acute promyelocytic leukemia (APL) has been rarely described in such patients, with only one case being published. We report a 30 years-old intravenous drug abuser HIV-infected male with APL who attained complete clinical, morphological, and molecular remission after differentiation therapy with all-trans-retinoic acid (ATRA) followed by intensive chemotherapy. The results of treatment in this patient and in other AML published cases suggest that therapy for AML should not be modified because of HIV infection if patients have an adequate performance status.

Adult↗

Effects of fosinopril on the blood pressure and lipid profile of patients undergoing heart transplantation.

PURPOSE: The purpose of this study was to determine whether the angiotensin-converting enzyme inhibitor, fosinopril, has an antihypertensive effect in patients undergoing heart transplantation (HT), as well as any action on lipid levels (total cholesterol and its fractions, triglycerides and lipoprotein[a] [Lp(a)]). METHODS: The study included 15 male patients aged 54 +/- 10 years; nine had undergone transplantation as a result of ischemic heart disease and six as a result of idiopathic dilated cardiomyopathy. The average time from the heart transplantation was 12 +/- 4 months. Six transplantations were performed after antidiabetic treatment, and six were performed with patients receiving a hypolipidemic agent. The subjects of the study were patients with mild to moderate hypertension who were receiving antihypertensive treatment; the antihypertensive medications were withdrawn during 7 days. Periodic blood pressure and basal analytic determinations were then carried out after 4 and 12 weeks of treatment and 7 days after withdrawal of the antihypertensive medications. RESULTS: Significant differences (p < 0.05) were found in the systolic blood pressure (SBP) and diastolic blood pressure (DBP) compared with the basal values (SBP 160 +/- 11 mm Hg; DBP 98 +/- 8 mm Hg), after 4 weeks of treatment (SBP 138 +/- 10 mm Hg; DBP 83 +/- 7 mm Hg), and after 12 weeks of treatment (SBP 137 +/- 12 mm Hg; DBP 84 +/- 9 mm Hg); these differences persisted 7 days after the drug was withdrawn (SBP 150 +/- 12 mm Hg; DBP 95 +/- 10 mm Hg). The total cholesterol, low-density lipoprotein (LDL) cholesterol, and Lp(a) dropped compared with the basal levels (total cholesterol 184 +/- 19, LDL cholesterol 123 +/- 13, Lp(a) 29 +/- 12), after 4 weeks (total cholesterol 172 +/- 21, LDL cholesterol 116 +/- 8, Lp(a) 26 +/- 8) and after 12 weeks (total cholesterol 169 +/- 20, LDL cholesterol 115 +/- 6, Lp(a) 25 +/- 8) of treatment, returning to basal values on withdrawal of the drug. CONCLUSIONS: Fosinopril is a useful drug for the treatment of the mild to moderate arterial hypertension of heart transplant recipients, in addition to being capable of reducing the serum levels of total cholesterol, LDL cholesterol, and Lp(a). It should therefore be considered a first-line antihypertensive agent with beneficial effects on the lipid profile.

Adult↗

[Acute lymphoblastic leukemia in adults. Comparative study of clinicobiologic characteristics and of response to treatment in terms of age in a group of 41 patients].

BACKGROUND: The aim of this study was to analyze the influence of age on the clinical and biological features as well as the results of treatment in 41 adult patients with acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS: The patients diagnosed with ALL from January 1989 to October 1995 in a single center were studied. Two groups of patients were analyzed based on age. The main clinical, hematologic and biochemical parameters, morphologic subtype and immunologic phenotype and the results of the cytogenetic study were analyzed. Likewise, the attainment of complete remission (CR), its duration and overall survival (OS) were also studied. Comparison of the cited variables and the results of treatment among the two groups of patients was performed. RESULTS: Group I was made of 19 (11 males, 8 females) patients > or = 50 years of age (mean age 65 +/- 9 years). Group II included 22 patients (11 males and 11 females) with a mean age of 28 +/- 11 years. Significant differences were only observed between the two groups in regard to the proportion of peripheral blood blasts (p < 0.02), serum LDH values (p = 0.05) and the performance status at the time of diagnosis ( p < 0.00007). In the patients in group 1 cytogenetic alterations were more frequent (10/16 vs 4/20, p < 0.02), being mainly pseudodiploid. Complete remission was achieved in 7/16 patients in group I and in 17/22 in group II (p < 0.02). The median duration of CR was 34 and 18 months, respectively. The median OS was 7 months in group 1 and 15 months in group II with an estimated survival at 5 years of 0% in group I and 38% in group II (p < 0.05). CONCLUSIONS: Patients with acute lymphoblastic leukemia over the age of 50 years have a worse general status and more cytogenetic alterations (particularly structural) than younger adult patients, presenting a lower probability of achieving complete remission and a shorter survival.

Adolescent↗

Histochemistry and role of nitric oxide synthase in the amphibian (Ambystoma tigrinum) inner ear.

Nicotinamide adenine dinucleotide phosphate reduced-diaphorase (NADPH-d) histochemistry was investigated in the axolotl (Ambystoma tigrinum) inner ear. Hair cells showed an intense NADPH-d reaction; afferent neurones also stained but less intensely than hair cells. Effects of NG-nitro-L-arginine (L-NOARG) on the basal discharge and mechanical responses of semicircular canal afferent neurones recorded extracellularly were also studied. L-NOARG (1 mu M) diminished the basal discharge and the response of afferent neurones to sinusoidal mechanical stimuli to 45 +/- 6.4% and 65 +/- 5.3% (mean +/- SEM) of control value, respectively. These findings suggest that production of nitric oxide (NO) by hair cells and probably also by afferent neurones contributes to the basal discharge and the response of afferent neurones to mechanical stimuli.

Ambystoma↗

Use of all-trans retinoic acid to treat acute promyelocytic leukemia: a case with very severe features at the onset in Nicaragua.

We observed a child with acute promyelocytic leukemia (APL) who, at the onset, had extremely severe hemorrhagic and septic complications. According to our experience in Nicaragua, there was a very high risk of early death. The patient was successfully treated with a program that included all-trans retinoic acid (ATRA) followed by cytotoxic chemotherapy. ATRA has two important features: it is effective in initial treatment of APL and it is inexpensive. Because of the high cost and the need for extensive supportive care, optimal myeloablative therapy used in patients with various types of acute myeloid leukemia generally cannot be given in developing countries. ATRA treatment for APL is affordable everywhere.

Antineoplastic Agents↗

Antagonism of glutamate receptors by a chromatographic fraction from the exudate of the sea anemone Phyllactis flosculifera.

In the search for new glutamate antagonists it seems promising to characterize the effects of venom from invertebrates that prey mainly on crustaceans. In this work, the exudate of the sea anemone Phyllactis flosculifera was used as a source of this type of compound. The action of chromatographic fraction D from P. flosculifera was tested upon microion-tophoretically evoked glutamate responses in intracellular recordings from central neurons of the land snail Zachrysia guanensis. Bath application of fraction D (2-8 mg/ml, n = 13) diminished both the excitatory and the inhibitory components of glutamate agonists in Z. guanensis neurons; this action was dose-dependent and partially reversible. Fraction D actions were also tested in the multiunit spontaneous and mechanically evoked responses of the glutamatergic junction between hair cells and afferent neurons of the axolotl Ambystoma tigrinum. Pressure ejection of fraction D in concentrations ranging from 0.5 to 2 mg/ml (n = 9) decreased the spontaneous and mechanically evoked activity of semicircular canal afferent neurons and the responses evoked by kainic acid and alpha-amino-3-hydroxy-5-methylisoxasole-4-propionic acid. This action was also dose-dependent and partially reversible. These results indicate that fraction D acts as a glutamate receptor antagonist in snail and amphibian neurons. Further studies are required to characterize the active compounds responsible for this action and its specificity upon the subtypes of glutamate receptors.

Ambystoma↗

Programmed cell death in the anuran tadpole tail requires expression of a cell surface glycoprotein.

Programmed cell death is generally perceived as a suicide process involving activation of an internal death program thought to be common to all cells. We have previously presented evidence supporting the view that, at least in the tadpole tail, programmed cell death may involve assassination by cytotoxic cells such as resident macrophages. In this report, we show that regression of tadpole tail slices in culture is blocked by tunicamycin and brefeldin A, demonstrating that the intracellular protein trafficking machinery must be intact. Regression is also blocked by concanavalin A and fucose, suggesting a requirement for a cell surface glycoprotein. These observations are consistent with our hypothesis that programmed cell death requires expression of specific markers on the surfaces of cells destined to die, identifying the cells bearing those markers as targets for destruction.

Animals↗