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Biomedical subjects

A Avila

Publications and source records attributed to A Avila.

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

Near final height in pubertal growth hormone (GH)-deficient patients treated with GH alone or in combination with luteinizing hormone-releasing hormone analog: results of a prospective, randomized trial.

To study the effects of delaying puberty in GH-deficient (GHD) children, we studied 21 GHD (9 boys, 14 girls), treatment-naive, pubertal patients in a prospective, randomized trial. Their chronological age was 14.3 +/- 1.6 yr, and their bone age was 11.3 +/- 1.1 yr (mean +/- SD) at the beginning of the study. Four patients who developed hypogonadotropic hypogonadism were subsequently excluded from the study. Patients were randomly assigned to receive GH + LH-releasing hormone analog (LHRH-A) (n = 7), or GH alone (n = 10). GH and LHRH-A treatment started simultaneously in each patient. GH (Nutropin) was administered at a dose of 0.1 U/kg x day sc, until patients reached a bone age (BA) of 14 yr in girls and 16 yr in boys, and LHRH-A (Lupron depot) was administered at a dose of 300 microg/ kg every 28 days in during 3 yr. We defined GH deficiency as patients with a growth velocity less than 4 cm/yr, BA delay more than 1 yr in relationship to chronological age, GH response to two stimulation tests less than 7 microg/L, associated with low serum insulin-like growth factor I and insulin-like growth factor binding protein 3 levels. Statistical analysis was performed by ANOVA or Kruskall Wallis when variances were not homogeneous. We observed a significant decrease in the rate of BA maturation in the group treated with GH+LHRH-A (1.5 +/- 0.2 yr) compared with the group treated with GH alone (4.2 +/-0.5 yr) during the 3 years of LHRH-A therapy (P < 0.05). This delay in BA maturation produced a significant gain in final height in the group treated with GH+LHRH-A, which reached - 1.3 +/- 0.5 SD score compared with -2.7 +/- 0.3 SD score (P < 0.05) in the group treated with GH alone. These results indicate that delaying puberty with LHRH-A in GHD children during treatment with GH increases final height.

Adolescent↗
PubMed1999

Estimation of the growth patterns of Oestrus ovis L. larvae hosted by goats in Baja California Sur, Mexico.

To estimate parameters for the variation in larval weight and dimension in Oestrus ovis L. and to describe the approximate pattern of growth, 2041 larvae were collected from 431 slaughtered goats and classified on a scale of 12 identified physiological ages, according to spiracular and integumental pigmentation. Larval live weight and measures of length, width, and thickness at the seventh segment were obtained. Weight increased from 0.23 mg in L1 larvae to 49 mg in late L2 larvae; however, the highest increases in weight were found to occur after the L2-L3 molt, especially during the early L3 period, when larvae acquired about 45% of the average mature weight (518 mg). Average larval length increased almost linearly from about 2 mm in L1 larvae to reach full length (21.3 mm) just before initiating integumental pigmentation, then it tended to stabilize until full maturation. Except for higher increases during the early L3 period, larval width and thickness increased linearly to reach mean maximum values (6.0 and 5.0 mm, respectively) at full maturity. Weight and measurement data were fitted by monophasic, s-shaped growth functions. The y = 0.25 [1 + tanh[0.504 (12-6.65)]] function (R2 = 0.99) indicated that L3 larvae began to have a decrease in weight gain rates before the beginning of integumental pigmentation. The patterns of growth of O. ovis described from individual measurements in larvae may be suitable for descriptive purposes.

Animals↗
PubMed1999

[Biodistribution of 99mTC-HMPAO in healthy rats and B16 melanoma carriers].

Scintigraphic studies carried out in melanoma patients have demonstrated that the 99mTc-HMPAO complex makes it possible to locate the lesion. A biodistribution and pharmacokinetic study of the 99mTc-HMPAO complex was carried out in B16-melanoma tumor healthy and carrier mice after an intravenous injection. Radioactivity was measured in the liver, kidneys, spleen, stomach, brain, blood and tumor. It was seen that at 15 minutes of the injections, 40% of the total activity distributed in the animal body was recorded in the tumor. An interesting effect observed is an increase in the tissue distribution curves in both experimental groups at 1-2 hours post-injection. According to the seriated imaging study results with 99mTc-HMPAO in B16 melanoma bearing mice, the best image is obtained 10-30 minutes after the injection.

Animals↗
PubMed1999

[Usefulness of the measurement of insulin-like growth factor (IGF-I) and IGF-1 binding protein-3 (IGFBP-3) for the diagnosis of growth hormone (GH) deficiency in children].

BACKGROUND: The diagnosis of GH deficiency (GHD) is based upon the results of GH stimulation tests, which have several drawbacks. AIM: To evaluate the usefulness of IGF-1 and IGFBP-3 for the diagnosis of GHD in prepuberal children. MATERIAL AND METHODS: We measured IGF-I and IGFBP-3 in three group of subjects: I. GHD (n: 24), height < -2SD for age (Z score, average +/- SD: -4.2 +/- 1.2), growth velocity < p10 (3.4 +/- 1.0 cm/year) and peak GH level on two GH stimulation tests < 7 ng/ml (1.2 +/- 0.6 ng/ml); II. Short non-GHD (NGHD, n: 32), height of -2.7 +/- 0.9 SD for age, growth velocity < p 25 (3.9 +/- 1.2 cm/year), and peak GH level on two GH stimulation tests > 7 ng/ml (15.3 +/- 6.9 ng/ml), y III. Normal school children (n: 35) with normal heights (-0.17 +/- 0.12 SD) were studied as controls. RESULTS: IGF-1 and IGFBP-3 were significantly lower in GHD than in NGHD and controls (p < 0.001), and in NGHD than in C (p < 0.001). We defined the normal range of both proteins as +/- 2 SD of the mean of the control group. Using this criteria, IGF-I was low in 21/24 GHD, and in 12/32 NGHD. IGFBP-3 was low in 22/24 GHD, and in 6/32 NGHD. Only 1 GHD patient had both exams in the normal range, suggesting that he is probably NGHD. 4/32 of the NGHD and both exams below normal range, suggesting that they are probably GHD. CONCLUSIONS: IGF-1 and IGFBP-3 are important tools for the diagnosis of GHD.

Child↗
PubMed1998

Unrecognized Tourette syndrome in adult patients referred for psychogenic tremor.

BACKGROUND: The diagnosis of Tourette syndrome may be overlooked in patients with severe psychopathologic disorder but mild motor manifestations of Tourette syndrome. OBJECTIVE: To describe 4 patients with long-lasting general psychopathologic disorder and previously unrecognized mild motor and phonic tics exacerbated during adulthood by the onset of tremor; all of the patients had been referred for the evaluation of psychogenic tremor. SUBJECTS: Four adult patients, with previous psychiatric diagnoses of depression (2 cases), generalized anxiety disorder (3 cases), malingering (1 case), and conversion disorder (3 cases). METHODS: Single case studies. RESULTS: Clinical interviews disclosed that the 4 patients had positive family histories of Tourette syndrome, and all had mild motor and phonic tics that had started before the age of 18 years. On neurologic examination, 2 patients had bilateral postural tremor of the hands that varied in frequency, rhythmicity, and amplitude, and the other 2 had resting tremor mimicking parkinsonism. All 4 patients described involuntary somatic sensations of the affected limbs, which they attempted to alleviate by executing movements. No consistent positive placebo response was observed, but in all patients tremoric movements improved with haloperidol. CONCLUSIONS: These cases illustrate an unusual movement disorder (tremor as a "tic equivalent") in adults with Tourette syndrome and emphasize that cases of the syndrome with mild tics often go unrecognized, precluding adequate treatment.

Adult↗
PubMed1998

Effects of eight months treatment with graded doses of a growth hormone (GH)-releasing peptide in GH-deficient children.

Stimulation of pituitary GH secretion with administered GHRH can be effective therapy for those GH deficient (GHD) patients whose disorder results from insufficient endogenous GHRH secretion. We have previously shown that most such patients also respond acutely to the GH-releasing peptides (GHRP's), which have a different mechanism of action from GHRH, with release of GH. In this study we tested whether the GH response to a newer GHRP, GHRP-2, would be sustained over time. Six prepubertal children with GHD and growth failure received stepwise increasing s.c. doses of GHRP-2, at 0.3, 1.0, and 3.0 micrograms/kg/day, in successive 2-month treatment periods, with monitoring of overnight 12 h episodic GH secretion and toxicity measures at the end of each period. During a fourth 2-month period, they received 3 micrograms/kg GHRP-2 together with 3 micrograms/kg s.c. GHRH. Serum levels of IGF-I and IGFBP-3 were also measured, and stadiometer height measurements were recorded. GHRP-2 administration produced a dosewise increase in overnight GH secretion. GH profiles showed that the effect of GHRP-2 injections was relatively brief, with little effect upon GH secretion later in the night. Serum levels of IGF-I and of IGFBP-3 did not increase. Growth velocity was higher during GHRP-2 treatment than during pretreatment and post-treatment evaluations. There were no side effects or toxicities observed. Thus GHRP-2 is well tolerated and is able to stimulate GH secretion. Formulations or routes of administration that allow for a longer duration of action will likely be needed to use GHRP-2 in therapy.

Adolescent↗
PubMed1998

Vinculin but not alpha-actinin is a target of PKC phosphorylation during junctional assembly induced by calcium.

The establishment of the junctional complex in epithelial cells requires the presence of extracellular calcium, and is controlled by a network of reactions involving G-proteins, phospholipase C and protein kinase C. Since potential candidates for phosphorylation are the tight junction associated proteins ZO1, ZO2 and ZO3, in a previous work we specifically explored these molecules but found no alteration in their phosphorylation pattern. To continue the search for the target of protein kinase C, in the present work we have studied the subcellular distribution and phosphorylation of vinculin and alpha-actinin, two actin binding proteins of the adherent junctions. We found that during the junctional sealing induced by Ca2+, both proteins move towards the cell periphery and, while there is a significant increase in the phosphorylation of vinculin, alpha-actinin remains unchanged. The increased phosphorylation of vinculin is due to changes in phosphoserine and phosphothreonine content and seems to be regulated by protein kinase C, since: (1) DiC8 (a kinase C stimulator) added to monolayers cultured without calcium significantly increases the vinculin phosphorylation level; (2) H7 and calphostin C (both protein kinase C inhibitors) completely abolish this increase during a calcium switch; (3) inhibition of phosphorylation during a calcium switch blocks the subcellular redistribution of vinculin and alpha-actinin. These results therefore suggest that vinculin phosphorylation by protein kinase C is a crucial step in the correct assembly of the epithelial junctional complex.

Actinin↗
PubMed1998

Increase in asialoganglioside- and monosialoganglioside-reactive antibodies in chronic Chagas' disease patients.

Antibodies reactive with the core glycan of asialoganglioside (GA1), monosialoganglioside (GM1), and disialoganglioside (GD1a) were studied in human sera. In healthy individuals, GA1-, GM1-, and GD1a-reactive antibodies were mainly of the IgM class, but also of the IgA and IgG classes, and were present at low titers in the serum of 68%, 79%, and 91% of the individuals studied, respectively. Levels of anti-GA1 and anti-GM1 antibodies, mainly of the IgA and IgG classes, were significantly elevated (P < 0.001) in 62% and 72% of subjects, respectively, chronically infected with Trypanosoma cruzi, with no association found with the degree of myocardial damage. No significant increase in anti-GA1 and anti-GM1 antibodies was found in dilated cardiomyopathy patients. The level of anti-GD1a antibody was not significantly different between healthy controls and chronic chagasic or dilatatory cardiomyopathy patients. Since the peripheral nervous system is very rich in gangliosides, it is possible that the increases in GA1- and GM1-specific antibodies that develop during chronic T. cruzi infection are involved in the pathology of peripheral neuropathy in Chagas' disease.

Animals↗
PubMed1998

[Risk factors and correlations with some tumor markers in the incidence of breast cancer in pre- and post-menopausal patients].

Between January and November 1992, forty eight women with benign disorders of the breast were studied and compared with one hundred fifty two patients with malignant disease of the breast. The content of alkaline phosphatase (ALP) levels was measured in the serum of premenopausal and postmenopausal patients. In all of them clinical history was taken, weight size and corporal mass index (CMI) (weight/size2). When the patients were grouped according to type of breast lesions, it appeared that plasmatic ALP levels, were higher in the groups with infiltrating carcinoma than in the women with benign disorders of the breast. The physiological status of the enzyme in this study, relate probably the activity of the tissue in either benign or malignant tissue, through fibroadenoma had less activity than adenocarcinoma. Status ALP (> or = 90 UI/L), CMI, menstrual state and histological type were compared. We found a significant correlation between these parameters.

Adenocarcinoma↗
PubMed1997

Oral autopsy of unidentified burned human remains. A new procedure.

Forensic dentistry plays an increasingly important role in medicolegal investigation and identification procedures. The oral examination may be difficult because of postmortem changes, especially those of carbonized corpses. We present a new technique of oral autopsy that includes a new means of access to the oral cavity designed for application on unidentified burned human remains. This technique preserves the facial configuration of the cadaver, allowing visual recognition by family members or other persons that is fundamental if the antemortem dental records do not exist or are not available. Also, this technique permits adequate work productivity by the forensic team members and can be used in difficult working conditions, such as mass-disaster scenarios.

Autopsy↗
PubMed1997

Effects of luteinizing hormone-releasing hormone analog-induced pubertal delay in growth hormone (GH)-deficient children treated with GH: preliminary results.

To study the effect of delaying epiphyseal fusion on the growth of GH-deficient children, we studied 14 pubertal, treatment naive, GH-deficient patients (6 girls and 8 boys) in a prospective, randomized, placebo-controlled trial. Chronological age was 14.5 +/- 0.5 yr, and bone age was 11.6 +/- 0.3 yr (mean +/- SEM) at the beginning of the study. Patients were assigned randomly to receive GH and LH-releasing hormone (LHRH) analog (n = 8) or GH and placebo (n = 6) during 3 yr, with planned continuation of GH treatment until epiphyseal fusion. Patients were measured with a stadiometer and had serum LHRH tests, serum testosterone (boys), serum estradiol (girls), and bone age performed every 6 months. Patients treated with GH and LHRH analog showed a clear suppression of their pituitary-gonadal axis and a marked delay in bone age progression. We observed a greater gain in height prediction in these patients than in the patients treated with GH and placebo after 3 yr of treatment (mean +/- SEM, 14.0 +/- 1.6 vs. 8.0 +/- 2.4 cm; P < 0.05). These preliminary findings suggest that delaying epiphyseal fusion with LHRH analog in pubertal GH-deficient children treated with GH increases height prediction and may increase final height compared to treatment with GH alone.

Adolescent↗
PubMed1997

Specific inhibitory effect of 3-deazaneplanocin A against several Leishmania mexicana and L. braziliensis strains.

The growth inhibitory effect of 3-deazaneplanocin A (c3NpcA) was tested against some pathogenic members of the family of American Trypanosomatidae. Under our culture conditions, c3NpcA displayed a strongly and uniformly leishmanistatic effect on all 23 American Leishmania (L. mexicana and L. brasiliensis) strains in the study (mean dose producing 50% inhibition compared with control parasite growth [ID50] = 96 ng/ml, 0.32 microM), but showed no inhibition against the several T. cruzi and T. rangeli strains tested with concentrations up to 10,000 ng/ml. This compound also induced a substantial expansion of the intracellular pools of both S-adenosylhomocysteine (AdoHcy) and S-adenosylmethionine (AdoMet), as well as a significant diminution of the AdoMet:AdoHcy ratio. Strong AdoHcy hydrolase activity was detected in American Leishmania promastigotes. At at a dose of 200 ng/ml, c3NpcA inhibited S-adenosyl-L-3H-methylmethionine and 3-thymidine incorporation by promastigotes after four days incubation in the presence of the drug. At a dose of 100 ng/ml, c3NpcA eliminated approximately 56% of the L. mexicana and L. brasiliensis from infected human macrophages, compared with simultaneously cultivated controls. Two schedules of 10 consecutive intraperitoneal injections of c3NpcA, with doses ranging from 0.5 to 1.5 mg/kg/day, significantly reduced development of cutaneous leishmanial infection produced in inbred BALB/c mice by L. b. guyanensis inoculation, although a few parasites remained at the inoculation site.

Adenosine↗