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G Morales

Publications and source records attributed to G Morales.

At least 37 records · Page 2Linked to original sources
PubMed2000

Diterpenoids from Haplopappus rigidus.

Fractionation of the aerial parts of Haplopappus rigidus Phil., directed by the brine shrimp lethality test (BST), has led to the isolation of two new diterpenoids, rigidusol and deacetylrigidusol. Their structures were established as 13-hydroxy-18-acetoxy-cis-cleroda-3,14-diene (8betaH, 10betaH, 19beta, 20alpha form) and 13,18-dihydroxy-cis-cleroda-3,14-diene (8betaH, 10betaH, 19beta, 20alpha form), respectively. Rigidusol exhibit moderate cytotoxic activity against human breast adenocarcinoma cell line MCF-7. Their structures were established by spectral data, in particular using 2D NMR spectroscopy (DEPT, DQF-COSY, HMQC and HMBC).

Asteraceae↗
PubMed2000

Mulinane-type diterpenoids from Laretia acaulis.

In addition to the known mulinolic acid and mulin-11, 13-dien-20-oic acid, 13-epimulinolic acid has been isolated from the aerial parts of Laretia acaulis (Cav.) Gill et Hook (Umbelliferae). Its structure was based on spectroscopic comparison with mulinolic acid and by chemical characterization.

Apiaceae↗
PubMed1999

Feeding frequency and nutritional status of peridomestic populations of Triatoma infestans from Argentina.

We studied the nutritional characteristics of peridomestic populations of Triatoma infestans from 25 habitats in an endemic area of Chagas disease in Argentina. The aim was to determine the feeding frequency, fresh weight of adults and older nymphs, and the gonotrophic status of females, in order to compare them with previous studies of domestic populations in the same region. The average infection rate of the bugs and blood meal origins were also determined in order to calculate the maximum risk for Trypanosoma cruzi transmission in these habitats. The number of bugs in each habitat correlated positively with the number of hosts. The estimated number of bites per night was strongly correlated with the total number of bugs collected from that habitat. The shortest biting interval (1.9 and 1.7 days) occurred in November and February, where 52-60% of insects suck blood each night. Adults and nymphs recently fed showed significantly higher fresh weight in November. There was no apparent correlation between the mean weights of adults or nymphs and the number of insects found within each habitat. Bloodmeal analysis showed that most of the bugs (87%) had fed from chicken, with human and dog scarcely represented and no bloodmeals identified from cat. However, human bloodmeals were only identified from chicken coops near the house (< 12 m). Almost all females (92-100%) captured during the spring months had been mated, whereas the proportion of mated females decreased significantly during summer (60-71%). The maximum risk (MR) average from these peridomestic habitats was 0.35 bites from infective bugs/night, tenfold lower than MR from domestic habitats. The good nutritional status of recently fed bugs, found in these chicken coops during all the hot season, suggest that active dispersal is unlikely to occur from peridomestic habitats.

Animals↗
PubMed1999

Development of myasthenia gravis after interferon alpha therapy.

Interferon (IFN) alpha is now used in the treatment of some malignant diseases and chronic viral hepatitis. There have been several reports of development of autoantibodies and autoimmune diseases or the deterioration of preexisting disorders in patients under treatment. We enclose a case of myasthenia gravis (MG) which developed after six weeks of treatment as fluctuating bilateral ptosis, intermittent diplopia, and mild weakness of limb and neck muscles. A test dose of edrophonium chloride was administered, resulting in improved muscle strength. Elevated anti acetylcholine receptor (AChR) antibody titer was found. Single fiber electromyography showed an increased jitter from extensor digitorum communis, frequently accompanied by transmission blocking. Repetitive electric 3 Hz stimulation of the abductor pollicis brevis muscle, revealed an abnormal decrement of 28% in compound motor action potential. Myasthenia gravis was diagnosed and the patient was given pyridostigmine, immunoglobulines and prednisone with benefit. Six months latter he developed an acute myasthenic crisis with severe respiratory failure and high anti AChR antibody titer. IFN-alpha can induce MG or simply manifests a preexisting subclinical disease, but otherwise its therapeutic efficacy in MG has been shown in experimental and clinical studies. Autoimmune mechanisms, as the release of different cytokines as IFN, by immunocompetent cells, may be involved in the pathogenesis of both MG and chronic active hepatitis. Autoantibody production against postsynaptic membrane structures by IFN-alpha could be the underlying pathophysiology.

Aged↗
PubMed1999

[Osteoporosis in Mexican postmenopausal women. Magnitude of the problem. Multicenter study].

Incidencia of osteoporosis induced fractures increases with age; risk increases exponentially as bone mass decreases. Women are prone to osteoporosis 2 to 3 times more than men, due to lower "peak" bone mass and the accelerated loss that occurs after the menopause. The prevalence of osteoporosis in with Caucasian postmenopausal women varies from 16 to 30% depending upon the number of sites measured (lumbar spine/hip and/or forearm). The aim of this study was to estimate the prevalence of osteopenia and osteoporosis in pre and postmenopausal Mexican women in relation to men, and to that reported in Caucasia women. The study involved 4,821 apparently healthy subjects (without known risk factors for osteoporosis), 4,467 females and 354 males from 11 different centers of Mexican Republic, 20 to 90 years old, using DXA bone densitometry of lumbar spine and hip. Prevalence of osteoporosis in women is twice that in men (P < 0.001), and it increases with age, particularly after the menopause (P < 0.0001). Our study found a prevalence of osteoporosis of the lumbar spine and/or hip in apparently healthy postmenopausal Mexican women over 50 years of age of 16%, increasing to 20% in those women with or without risk factors who attended voluntarily or by suggestion of their physician to be studied. The prevalence values obtained seem to be lower than those reported for Caucasian women, 30%. We found a prevalence of osteoporosis of 16% and of osteopenia of 57% in women 50 years of age and older. We also found a higher prevalence of osteoporosis in women of the south east part of the county.

Female↗
PubMed1998

The expression of the Leishmania infantum KMP-11 protein is developmentally regulated and stage specific.

Transcription of the gene coding for the KMP-11 protein of Leishmania infantum results in the production of a mature RNA transcript of 1.3 kb in length. The expression of KMP-11 mRNA is strongly down-regulated not only during the parasite growth from the logarithmic to the stationary phase but also during the differentiation transit from promastigotes to amastigotes. The estimated concentration of KMP-11 is one order of magnitude higher in promastigotes than in amastigotes. The analysis of the Triton X-114 phase partition of the protein shows that, in agreement with its predicted secondary structure, KMP-11 has an amphipathic nature since it is found in the aqueous as well as in the detergent phase. By fluorescence microscopy a defined pattern of distribution of the protein was observed only in promastigotes where KMP-11 is mainly located in the flagellum and the flagellar pocket.

Animals↗
PubMed1998

Outbreaks of trypanosomosis due to Trypanosoma vivax in cattle in Bolivia.

This paper reports the first occurrence of bovine trypanosomosis due to Trypanosoma vivax in Bolivia. T. vivax was identified in thin blood smears of 159 cattle from the Provinces of Velaco (57), Nuflo de Chavez (20), Guayaros (30) and Chiquitos (52), and in 86.20% of 29 cattle from Laguna Concepción examined by microhematocrit test. The clinical signs observed were fever, anemia, abortion, progressive weakness, loss of appetite, lethargy, substantial weight loss in a relatively short time, and progressive emaciation.

Abortion, Veterinary↗
PubMed1998

Induction of a selective and persistent extravasation of neutrophils into the peritoneal cavity by tryptase mouse mast cell protease 6.

Recombinant mouse mast cell protease 6 (mMCP-6) was generated to study the role of this tryptase in inflammatory reactions. Seven to forty-eight hours after the i.p. injection of recombinant mMCP-6 into BALB/c, mast cell-deficient WCB6F1-Sl/Sl(d), C5-deficient, or mMCP-5-null mice, the number of neutrophils in the peritoneal cavity of each animal increased significantly by >50-fold. The failure of the closely related recombinant tryptase mMCP-7 to induce a comparable peritonitis indicates that the substrate specificities of the two tryptases are very different. Unlike most forms of acute inflammation, the mMCP-6-mediated peritonitis was relatively long lasting and neutrophil specific. Mouse MCP-6 did not induce neutrophil chemotaxis directly in an in vitro assay, but did promote chemotaxis of the leukocyte in the presence of endothelial cells. Mouse MCP-6 did not induce cultured human endothelial cells to express TNF-alpha, RANTES, IL-1alpha, or IL-6. However, the tryptase induced endothelial cells to express large amounts of IL-8 continually over a 40-h period. Neither enzymatically active mMCP-7 nor enzymatically inactive pro-mMCP-6 was able to induce endothelial cells to increase their expression of IL-8. Although the mechanism by which mMCP-6 induces neutrophil accumulation in tissues remains to be determined, the finding that mMCP-6 induces cultured human endothelial cells to selectively release large amounts of IL-8 raises the possibility that this tryptase regulates the steady state levels of neutrophil-specific chemokines in vivo during mast cell-mediated inflammatory events.

Animals↗
PubMed1998

[Neuromuscular disorders in critically ill patients].

INTRODUCTION AND OBJECTIVE: Critically ill patients admitted to the Intensive Care Unit (ICU) often develop neuromuscular disorders. The objective of this study was to diagnose these and determine the causes. MATERIAL AND METHODS: We present a series of 13 critically ill patients who developed weakness or paresia, reduced or absent ROT and normal brain stem reflexes, in whom ENG and EMG studies were done in EESS and II which were considered together with data from general laboratory analysis, radiological and microbiological examinations, medication given and posterior clinical course of the patient. Muscle biopsy was not done in any patient. RESULTS: All the patients were intubated, with signs of sepsis, multiple-organ failure and malnutrition. All had received cortico-steroids and amino-glucosides and 8/13 neuromuscular blockers. Neurophysiological study showed that in all cases there was axon type neuropathy, mainly motor and in the lower limbs. Fifty four percent of the patients died. The neuropathy improved in the others. CONCLUSIONS: Critically ill patients often have axon type neuropathy. In our series, the causes of this were sepsis and multiple organ failure. It is important that this pathology be ruled out in the critically ill patient whom it is difficult to disintubate and/or has generalized muscle weakness.

Adult↗
PubMed1998

[Familial benign partial epilepsy of early infancy].

INTRODUCTION AND CLINICAL CASES: We present two patients who at the ages of 5 and 17 months respectively presented with convulsive crises with motor signs, of partial onset and secondary generalization, which eventually became normal. Both patients had a family history of first degree relatives with similar illnesses and are at present-five years later-well and with normal development, school achievement and neurological examination findings. The clinical characteristics, normal biochemical and neuroimaging investigations and EEG characteristics suggest the diagnosis of benign partial epilepsy of early infancy. This syndrome is characterized by its appearance during the first year of life, having no known etiological factors, with partial crises occurring several times a day and with a course leading to remission. Its frequency may be greater than is thought. There is a pattern of dominant autosomal inheritance, with a gene recently found on chromosome 19. CONCLUSION: We consider that this syndrome should be included in the International Classification of Epilepsy and Epileptic Syndromes as benign familial idiopathic partial epilepsy.

Epilepsies, Partial↗
PubMed1997

Mapping of the antigenic determinants of the Leishmania infantum gp63 protein recognized by antibodies elicited during canine visceral leishmaniasis.

The gp63 gene encoding the major surface antigen of Leishmania infantum has been cloned and sequenced. In spite of the overall sequence homology with the gp63 genes from other Leishmania species, particularly with the constitutively expressed Leishmania chagasi Gp63 gene, the carboxy-terminal ends of these genes are clearly divergent (62% homology). To study the prevalence of anti-gp63 antibodies in the sera from dogs with visceral leishmaniasis, a recombinant L. infantum gp63 protein was expressed in Escherichia coli. It was found that 100% of the sera from these dogs recognized the recombinant gp63 protein, suggesting that it must function as a potent B cell immunogen during natural canine visceral leishmaniasis. However, heterogeneity in the level of response was observed. Fine mapping of the antigenic determinants was performed by means of 6 overlapping subfragments of the gp63 protein and by the use of a library of synthetic peptides. The data showed that there is some degree of immunological restriction in the recognition of the protein since reactivity was observed preferentially against the most divergent region. The epitope mapping of this region showed 2 immunodominant peptides the response to which seems to be preferentially of the IgG2 type.

Amino Acid Sequence↗
PubMed1997

[Andermann syndrome: presentation of a case].

INTRODUCTION: Peripheral neuropathy with agenesis of the corpus callosum (or Andermann's syndrome) is a hereditary autosomal recessive disorder rarely found outside certain regions of Quebec Province (Canada). It is associated with mental retardation and various dysmorphic changes. Deterioration is usually progressive with loss of motor skills, development of scoliosis during adolescence, tendency to behaviour disorders and death during the third decade (approximately). CLINICAL CASE: We present a 13 year old girl diagnosed as having the spastic tetraparesic type of PCI, who was sent to us so that we could reconsider the diagnosis in view of the atypical course of the illness. The patient had an unusual phenotype with dysmorphic changes (mainly facial), axial hypotonia with flexion-retraction of the hands, generalized arreflexia, neurogenic bladder, skin changes with ulcers on the legs and mental retardation. Neurophysiological studies showed a predominantly motor polyneuropathy. There were signs of axonal neuropathy on both sural nerve and skeletal muscle biopsies. The clinical features, phenotype, microcephaly with agenesis of the corpus callosum and a posterior fossa cyst, associated with spinal atrophy indicated the diagnosis of Andermann's syndrome. CONCLUSIONS: This case is of interest in view of the exceptional rarity of Andermann's syndrome in our population.

Adolescent↗
PubMed1996

Synergistic neurite-outgrowth promoting activity of two related axonal proteins, Bravo/Nr-CAM and G4/Ng-CAM in chicken retinal explants.

In the developing chicken retina, optic fibres migrating to the tectum express on their surfaces several cell adhesion molecules, including Bravo/Nr-CAM and G4/Nr-CAM and G4/Ng-CAM. We have previously described differential distribution along the retinotectal projection and differential modulation by environmental cues for Bravo and G4 and here we further compare the characteristics of these immunoglobulin superfamily molecules. From day 6 of embryonic development (E6) to 20 (E20), Bravo and G4 were found to coexist in the retinal optic fibre layer. However, while G4 staining was confined to that layer, as development proceeded Bravo staining spread to plexiform layers and some radial structures of the retina. G4 displayed a dose-dependent neurite-outgrowth promoting activity for E6 retinal explants, while Bravo did not support neurite growth. Surprisingly, when the retinal explants were grown on mixtures of the two molecules, a much more vigorous growth of neurites was seen, revealing a synergistic effect. We propose that Bravo and G4, as well as other axonal surface molecules, affect axonal growth in different ways when they are present in combination than when they are alone.

Animals↗
PubMed1996

[Anal incontinence in patients with rectal neoplasms previous to surgical intervention].

HYPOTHESIS: Patients with rectal carcinoma may have anal continence disorders before the operation, in relation to age. AIM: To evaluate the anorectal function in a consecutive sample of patients with rectal carcinoma before the operation. MATERIAL AND METHODS: 56 consecutive patients with rectal carcinoma were studied and classified into two groups according to anal continence: continent and incontinent. Anorectal function were evaluated in all patients: Perineometry (perineal measurements at rest and during a straining effort), Anal manometry (anal pressures and rectal capacity), Pudendal nerve terminal motor latency. STATISTICAL ANALYSIS: quantitative data: -test (confidence interval), qualitative data: Fischer exact test. RESULTS: Anal continence: continent 41, incontinent 15. All patients with anal incontinence were more than 60 years old (p<0.01). Mean age: continent 61.3 +/- 12.4, incontinent 74.3 +/- 6 (p<0.01, CI 8.02-17.98). Perineal measurement: at rest: continent 2.97 +/- 0.69. incontinent 2.54 +/- 0.56 (p<0.05, CI 0.03-0.83), with straining effort: continent 1.37 +/- 0.86, incontinent 0.81 +/- 0.92 (p < 0.05, CI 0.03 - 1.86). Pudendal latency: continent 1.9 +/- 0.3, incontinent 2.3 +/- 0.5 (p<0.01, CI 0.11-0.69). There was no significant difference in the manometric data. CONCLUSION: Patients with rectal carcinoma have preoperative anal continence alterations, in relation to pelvic disorders and age.

Adult↗
PubMed1996

Conservative treatment versus antireflux surgery in Barrett's oesophagus: long-term results of a prospective study.

The results obtained for the treatment of 59 patients diagnosed with Barrett's oesophagus, randomized to receive medical treatment (n = 27) or antireflux surgery (n = 32) were assessed prospectively. Median follow-up for the patients undergoing medical treatment was 4 (range 1-11) years and for patients undergoing surgical treatment 5 (range 1-11) years. Satisfactory symptomatic control (excellent to good results) was achieved in 24 patients after medical therapy and in 29 after antireflux surgery. The proportion of patients with persistent inflammatory lesions (54 per cent) and persistent or recurrent stenosis (47 per cent) was significantly higher after conservative treatment than after surgery (5 and 15 per cent, respectively). A decrease in the length of the segment of columnar mucosa was observed in eight of the patients who underwent antireflux surgery, and in only two of those given medical therapy. Conversely, an upward progression of the columnar lining was more frequent in the latter group (11 versus three). Mild dysplasia was observed in five patients, all from the group undergoing medical treatment. Severe dysplasia was detected in two patients, one undergoing medical treatment and the other following surgical therapy, in whom an antireflux procedure had failed previously. Both patients underwent oesophageal resection, with confirmation of a carcinoma in situ. The patients in whom antireflux surgery proved effective showed no dysplastic change or progression to adenocarcinoma. These results, despite the small number of patients and methodological limitations, question the systematic conservative approach in the initial management of patients with Barrett's oesophagus.

Adolescent↗
PubMed1995

Factors involved in the return of peristalsis in patients with achalasia of the cardia after Heller's myotomy.

OBJECTIVE: To assess the reappearance of peristalsis in a group of 45 patients with achalasia of the cardia undergoing surgery and to analyze the factors involved in this phenomenon. METHODS: According to the postoperative manometric data, the 45 patients were divided into two groups, depending on whether or not they presented a return of peristalsis. A statistical comparison of age, sex, duration of the disease, pre- and postoperative radiological diameter of the esophagus, classic or vigorous nature of the achalasia, and manometric data of the lower esophageal sphincter and esophageal body was made. RESULTS: In 46.6% of the patients, peristalsis returned to the upper esophagus, and 100% of the waves were progressive; in 24.4%, peristalsis returned to the middle third also, but only 50% of the waves were progressive; and in 8.8% (four patients), peristalic activity returned to the whole esophagus, but only 40% of the waves were progressive. The group of patients with a return of peristalsis had a shorter duration of dysphagia, less preoperative dilation of the esophagus, and a greater contractile activity of the esophageal body. CONCLUSIONS: Return of peristalsis is a frequent phenomenon after myotomy in patients with achalasia of the cardia, especially in cases of short clinical evolution, little esophageal dilation, and a conserved contractile capacity, although its accurate production mechanism is unknown.

Adolescent↗
PubMed1994

The Leishmania infantum histone H3 possesses an extremely divergent N-terminal domain.

The isolation of a Leishmania cDNA clone coding for an antigen identified as the histone H3 is described. The nucleotide sequence of the cDNA predicts that the Leishmania histone H3 contains 129 residues and that it has a molecular mass of 14,620 Da. Comparison of the amino acid sequence with the consensus sequence of the eukaryotic histone H3 shows that the Leishmania protein has a highly conserved globular region and an extremely divergent amino-terminal portion.

Amino Acid Sequence↗