Biomedical subjects

V Jiménez

Publications and source records attributed to V Jiménez.

At least 19 recordsLinked to original sources

PubMed2007

Apoptosis as a possible mechanism of infertility in Echinococcus granulosus hydatid cysts.

Echinococcus granulosus is a parasitic cestode causing hydatidosis in intermediate hosts (human and herbivorous). Most symptoms of the disease occur by the pressure exerted on viscera by cysts that are formed upon ingestion of the parasite eggs excreted by definitive hosts (canines). Protoscoleces, the developmental form of the parasite infective to definitive hosts, are formed in the germinal nucleated layer of fertile hydatid cysts. For unknown reasons, some cysts are unable to produce protoscoleces (infertile hydatid cysts). In this study, analysis of DNA fragmentation using TUNEL and agarose gel electrophoresis showed higher levels of apoptosis in infertile cysts as compared to fertile cysts. Additionally, caspase 3 was detected both in fertile and infertile cysts; the activity of this enzyme was found to be higher in infertile cysts. We conclude that apoptosis may be involved in hydatid cyst infertility. This is the first report on the presence of programmed cell death in E. granulosus.

Animals↗

PubMed2006

Circadian rhythms of prolactin secretion in neonatal female rabbits after acute separation from their mothers.

Newborn rabbits (Oryctolagus cuniculus) are only nursed for 3-5 min every 24 h and show a circadian increase in activity in anticipation of nursing. The objective of this study was to determine, in neonatal female rabbits after acute separation from the doe for 48 h, the changes in 24-h rhythms of plasma prolactin and median eminence and anterior pituitary concentration of dopamine (DA) and serotonin (5HT). In addition, median eminence concentration of the excitatory amino acid transmitters glutamate (GLU) and aspartate (ASP) and of the inhibitory amino acid transmitters gamma-aminobutyric acid (GABA) and taurine (TAU) was measured. A significant 21% increase of circulating prolactin occurred in isolated pups. In controls pups, plasma prolactin levels showed two peaks, during the first half of the light phase and at the beginning of the scotophase, respectively. In the isolated pups, a phase advance of about 4 h occurred for the two prolactin peaks. Hemicircadian changes of median eminence DA were found in controls, whereas a single daily peak (at 17:00 h) was found in the separated pups. Plasma prolactin and median eminence DA correlated significantly and inversely in the control group only. Pituitary DA content exhibited a single peak in controls and a hemicircadian pattern in isolated pups. Plasma prolactin and pituitary DA correlated significantly in isolated pups only 00000. Pup isolation decreased median eminence 5HT levels, augmented pituitary 5HT levels and disrupted their 24 h rhythmicity. Circulating prolactin correlated inversely with median eminence 5HT and directly with adenohypophysial 5HT only in controls. Isolation of pups generally modified the 24 h pattern of median eminence excitatory and inhibitory amino acid content by causing a prominent decrease at the beginning of the light phase. The results indicate that circadian rhythmicity of prolactin secretory mechanisms in female rabbit pups is significantly affected by pup's isolation from the doe.

Animals↗

PubMed2006

Twenty-four hour rhythm of plasma prolactin in female rabbit pups. Correlation with hypothalamic and adenohypophysial dopamine, serotonin, gamma-aminobutyric acid and taurine content.

Lactation in the rabbit is a nocturnal activity, extremely short and regular, that can be a strong synchronizer for the development of circadian rhythmicity in the pups. In the present study, 24-h rhythmicity of plasma prolactin and median eminence and anterior pituitary content of dopamine (DA), serotonin (5HT), gamma-aminobutyric acid (GABA) and taurine were examined in 11 days old female pups kept under 16 h light:8 h dark photoperiods (lights on at 08:00 h). Groups of six to seven female rabbit pups were killed by decapitation at six different time points throughout a 24-h cycle, starting at 09:00 h. Plasma prolactin levels changed significantly throughout the day, showing two peaks, one at first half of rest span (at 13:00 h) and another one at the beginning of the scotophase (at 01:00 h), just preceding doe visit. Median eminence DA content changed in a bimodal way as a function of time of day, displaying two maxima, at the beginning of the rest span and of the activity phase. Median eminence DA and plasma prolactin correlated significantly in an inverse way. Two maxima in median eminence 5HT levels were found, about 4 h in advance to the prolactin peaks. Circulating prolactin correlated inversely with median eminence 5HT content and directly with adenohypophysial 5HT content. Median eminence GABA content reached its maximum at the beginning of the scotophase and correlated significantly with plasma prolactin concentration. A positive correlation between plasma prolactin and adenohypophysial taurine content was observed. These results show that the circadian rhythmicity in prolactin secretory mechanisms in female rabbit pups develops during the early neonatal life.

Aging↗

PubMed2004

Superior cervical ganglionectomy differentially modifies median eminence and anterior and mediobasal hypothalamic GABA content in male rats: effects of hyperprolactinemia.

This work was undertaken to analyze the changes in GABA concentrations in the anterior and mediobasal hypothalamus and in the median eminence after acute or chronic superior cervical ganglionectomy (SCGx), and whether high prolactin levels interfere with the effects of SCGx on GABA content. Acute but not chronic SCGx increased GABA content in all the areas studied, as compared to controls. The presence of a pituitary graft abolished the effects of acute SCGx in the median eminence and anterior hypothalamus, as compared to controls, but potentiated its effects in the mediobasal hypothalamus. Chronic SCGx increased GABA content in the mediobasal and anterior hypothalami, as compared to pituitary grafted controls. Acute SCGx decreased plasma prolactin and GH levels, but chronic surgery did not modify these hormone plasma levels. Acute SCGx increased plasma ACTH levels, whereas chronic SCGx did not modify them. Pituitary grafting increased circulating values of prolactin, ACTH and GH, as compared to controls. Acute SCGx did not modify plasma prolactin levels in grafted animals, although it increased plasma GH levels and decreased those of ACTH in this experimental group. Chronic SCGx further increased both plasma prolactin and GH levels, without modifying plasma ACTH levels. These results suggest that SCGx differentially modifies GABA content within the hypothalamus and median eminence. Induction of hyperprolactinemia in the neonatal age interferes with SCGx effects on both GABA content within the hypothalamus and median eminence and the secretory patterns of the pituitary hormones studied.

Animals↗

PubMed2004

Experimental allergic encephalomyelitis in male Lewis rats subjected to calorie restriction.

This work analyzes the effect of calorie restriction on the development of experimental allergic encephalomyelitis (EAE) in Lewis rats. Plasma levels of ACTH, corticosterone, prolactin and growth hormone (GH) and mitogenic responses in submaxillary lymph nodes were measured. Male Lewis rats (6 weeks-old) were submitted to a calorie restriction equivalent to 66% of food restriction or to a normal diet. Fifteen days later, rats were injected with complete Freund's adjuvant plus spinal chord homogenate (SCH) or with complete Freund's adjuvant alone. Rats were monitored daily for clinical signs of EAE and were killed on day 15 after immunization. Only rats subjected to normal diet exhibited clinical signs of the disease. The increase in plasma ACTH and corticosterone found after SCH immunization in controls was not detectable in calorie restricted rats. Likewise, the correlation between circulating ACTH and corticosterone was no longer found after calorie restriction. Generally, calorie restriction by itself augmented plasma ACTH or corticosterone and this increase was not further amplified by SCH immunization. Only calorie restricted rats exhibited augmented plasma prolactin levels after SCH immunization, and decreased plasma GH levels regardless of immunization. Calorie restriction depressed the mitogenic response of lymphoid cells to concanavalin A but not to lipopolysaccharide. Calorie restricted rats did not exhibit augmented mitogenic response to concanavalin A following SCH immunization as those found in controls. The results are compatible with the view that the course of EAE can be significantly modified by caloric restriction.

Adrenocorticotropic Hormone↗

PubMed2003

Progression of HIV infection and mortality by hepatitis C infection in patients with haemophilia over 20 years.

Hepatitis C virus (HCV) infection is an important cause of mortality in human immune deficiency virus (HIV)-positive haemophiliacs. This study describes progression to AIDS, death from HCV end-stage liver disease (ESLD) and all-cause mortality over 20 years. All HIV-positive haemophiliacs in La Paz University Hospital were included in this cohort. HIV seroconversion was estimated using mathematical techniques for interval-censored data from 1979 to 1985. Poisson regression was used to estimate rates of AIDS, death from ESLD and all causes in different periods: before 1988, 1988-89, 1990-91, 1992-93, 1994-95, 1996-97 and 1998-2001 using competing risk models. Among 383 cohort members, global AIDS incidence was 9.7 per 100 person-years, peaking in 1992-93 and dropping by 87% in 1998-2001 compared with before 1988 [incidence rate ratio (IRR) 0.13; 95% CI: 0.03-0.53]. Overall mortality was 7.5 per 100 person-years, was highest from 1992 to 1997, and fell by 66% in 1998-2001 compared with before 1988 (IRR 0.34; 95% CI: 0.14-0.81). Eighteen (5%) persons died of ESLD which represented 19% of deaths before 1988, 4% during 1988-89, 1990-91 and 1992-93, 2% in 1994-95, 10% in 1996-97 and 33% in 1998-2001. Overall death rate from ESLD was 0.5 cases per 100 person-years with no statistically significant trend observed over time. Important reductions in HIV disease progression to AIDS and death have been observed from 1998 to 2001, and can be attributed to highly active antiretroviral therapy. Although no increase in the rate of HCV-related deaths can be demonstrated, HCV accounts for an increasing proportion of deaths in the recent years.

Acquired Immunodeficiency Syndrome↗

PubMed2002

Chronobiological features of the immune system. Effect of calorie restriction.

The circadian organization of living organisms is fully established being a key component the activity of the neuro-endocrin-immune system that maintains the homeostasis. Secondary lymph organs, such as submaxillary lymph nodes and spleen, have been shown to exhibit a 24 h variation in blastogenic proliferative capacity and distribution of B and T subsets, with specific achrophases depending on the parameter studied or the lymphoid organ considered. However, less is known about the thymus. The immune system has been shown to change by calorie restriction, although no information is available about possible effects in 24 h variations. Similar questions can be posed for the neuro-endocrine system. As an example, some data are shown in this article about the effects of calorie restriction on the neuro-endocrin-immune system in growing male Wistar rats. Calorie restriction blunted the circadian secretory pattern of TSH observed in the control group that was characterized by the existence of two peaks at 17:00 or 01:00 h and that explained the low basal metabolic rate of these animals under this experimental condition. Concerning the immune system, the thymus gland exhibited 24 h variations in T, B and immature cells in both control and calorie-restricted male rats, thus confirming the circadian organization of the immune system. Moreover this circadian organization was changed by calorie restriction.

Animals↗

PubMed2000

[Small-cell carcinoma of the larynx].

Primary small-cell (also known as oat-cell) neuroendocrine carcinoma of the larynx is an infrequent tumor. We report a case of epiglottic oat-cell carcinoma in a 57-year-old man. Its association with other malignant neoplasms and aggressive behavior in spite of treatment are discussed.

Biopsy↗

PubMed2000

[The elderly with AIDS. Case report].

When we speak about AIDS, even today, we rarely associate it with the elderly. Nonetheless, nursing care reality demonstrates that AIDS cases are more numerous all the time inside this population group known as the third generation. We should not forget that sex is a personal experience that can be practiced at all ages, and is not limited only to the young, and that preventive measures are necessary in all situations. Therefore, it is interesting to share what these authors reflect about this topic; they refer to a real case. It will probably be necessary to change the established schemes and consider this age group to be one in need of information on the possibilities of contagion. It will also be essential to carry out faster diagnoses and to develop educational measures as well as continuing professional development procedures in order that the elderly be considered susceptible to suffer this disease and to improve the treatment provided to the elderly. AIDS does not discriminate. Therefore, we cannot discriminate either.

Acquired Immunodeficiency Syndrome↗

PubMed2000

Peritoneal dialysis is the therapy of choice for end-stage renal disease patients with hereditary clotting disorders.

Chronic renal failure is an unusual complication of hereditary clotting disorders (HCDs), but this situation could change in the near future. The modality of dialysis for end-stage renal disease (ESRD) in patients with an HCD is a difficult choice. Hemodialysis (HD) may be considered, but intensive treatment with coagulation factors is required for vascular access execution and for each HD procedure. Peritoneal dialysis (PD) has been infrequently proposed. However, PD requires coagulation replacement therapy only during peritoneal catheter placement. The aim of this paper is to describe our experience of three patients with ESRD and HCD, successfully treated with chronic PD in the medium term. Case 1 was a 58-year-old man with moderate hemophilia A, type 2 diabetes mellitus, and hepatitis C virus (HCV) infection. His ESRD was secondary to glomerulonephritis. A double-cuff peritoneal catheter was surgically placed with pre-emptive factor VIII administration. He began treatment with continuous ambulatory peritoneal dialysis (CAPD). An inguinal hernia was repaired without complications. After eleven months of follow-up, no hemorrhage episodes have been observed and clinical outcome is optimal. Case 2 was a 46-year-old man with severe hemophilia A, type 2 diabetes mellitus, and HCV and human immunodeficiency virus (HIV) infections. He developed a diabetic nephropathy that required renal replacement therapy. A permanent silicone catheter was inserted in the left internal jugular vein, and the patient started HD treatment. Later on, PD therapy was proposed. A peritoneal catheter was implanted with simultaneous factor VIII infusion. Minimal bleeding was observed at the subcutaneous tunnel over the following 48 hours. The patient started PD treatment without complications, and two months later, remaining asymptomatic, transferred to another center. Case 3 was a 41-year-old woman diagnosed with von Willebrand disease type 2A, HCV infection, and polycystic kidney disease, who presented with ESRD. An internal arteriovenous fistula was performed under coagulation factor cover. During a fistulography, and despite coagulation factor substitutive treatment, the patient showed an important hematoma. Afterwards, PD was considered. A peritoneal catheter was implanted under coagulation factor cover. The postoperative course was uncomplicated, and the patient started CAPD treatment. During follow up, she suffered two hemoperitoneum episodes that were resolved with cold dialysate. After nine months, she uneventfully continued on PD. In conclusion, PD is the therapy of choice for patients with hereditary clotting disorders and ESRD requiring dialysis. Peritoneal dialysis therapy avoids many of the complications related to HD therapy.

Adult↗

PubMed1997

Broadly reactive antibodies against a gp120 V3 loop multi-epitope polypeptide neutralize different isolates of human immunodeficiency virus type 1 (HIV-1).

A gene encoding for a novel multi-epitope polypeptide (TAB4) was synthesized and expressed in Escherichia coli. The protein was composed of 15 amino acid fragments derived from the V3 loop of HIV-1 isolates MN, IIIB, RF, JY1, BRVA and LR150, joined by five-amino-acid linkers. Immunogenicity of TAB4 in rabbits was studied, and the antibody response against individual peptides investigated. TAB4 was shown to be immunogenic in Complete Freund's Adjuvant in a dose-dependent manner, and was able to elicit a humoral response against all V3 epitopes included on the protein. Sera from some of the animals were able to neutralize the replication of viral strain MN, and in one case IIIB, with moderate titers. Some sera also neutralized several Cuban clinical strains, isolated in peripheral blood mononuclear cells, after one round of amplification in MT4 cells.

Amino Acid Sequence↗

PubMed1997

Triclabendazole treatment in experimental goat fasciolosis: anthelmintic efficacy and influence in antibody response and pathophysiology of the disease.

A controlled test of the efficacy of triclabendazole against all stages (early immature, late immature and mature) of Fasciola hepatica has been performed in experimentally infected goats. The influence of triclabendazole treatment on the pathophysiology of the disease, in terms of haematological parameters and serum enzyme levels, and in the dynamics of production of specific antibodies to excretory/secretory products (ESP) of F. hepatica were also examined. Goats were orally infected with 200 viable metacercarie and treated at 4, 8 and 16 weeks postinfection (PI) with triclabendazole at the dose rate of 10 mg kg-1 body weight. The drug can be regarded as highly effective against mature (100%) and late immature (99.2%) flukes and effective against early immature flukes (94.9%). A moderate anaemia was found associated with the presence of late immature and mature flukes in bile ducts. Treatment with triclabendazole, by eliminating most of these flukes, largely reduced haematological alterations. Serum levels of the enzymes aspartate aminotransferase, lactate dehydrogenase and gamma-glutathione transferase reflected hepatic damage during goat fasciolosis. Early treatment (at 4 weeks PI) prevents the development of both parenchyma and bile ducts lesions; treatment at 8 weeks PI only prevents bile ducts lesions and treatment at 16 weeks PI has no appreciable effect on the development of the main hepatic lesions. The antibody response to F. hepatica ESP, as measured by enzyme-linked immunosorbent assay, was also affected by treatment with triclabendazole. In all treated animals a peak in antibody levels was observed between weeks 9 and 13, followed by a drop whose magnitude depended on the efficacy of treatment. In those animals in which triclabendazole was highly effective, antibody levels fell back to negative values similar to those recorded preinoculation at 18-21 weeks PI.

Analysis of Variance↗

PubMed1995

Plasma neurotransmitters, blood pressure, and heart rate during supine-resting, orthostasis, and moderate exercise conditions in major depressed patients.

Major depressed patients showed greater heart rate, noradrenaline, and free-serotonin values than normal. Conversely, platelet-serotonin values in major depressed patients were significantly lower than normal. Patients registered the normal differential blood pressure reduction during orthostasis. They also revealed progressive and significantly higher heart rate rises during orthostasis and exercise periods, when compared to normals. Whereas noradrenaline showed maximal rises during the two last periods, adrenaline only showed small but significant increase during exercise. The analysis of correlations, together with the above data, suggests that major depressed patients register maximal neural sympathetic activity as well as adrenal glands sympathetic hypoactivity. In addition, these patients show hyperparasympathetic activity, as reflected by the free-serotonin profile. Finally, the fact that both the Hamilton Depression Rating Scale and the self-rating Beck Depression Inventory correlated positively with noradrenaline/adrenaline ratio and free-serotonin values strongly suggests that both neural sympathetic and cholinergic mechanisms are involved in major depression.

Adrenal Glands↗

PubMed1995

Plasma neurotransmitters, blood pressure, and heart rate during supine resting, orthostasis, and moderate exercise in dysthymic depressed patients.

Dysthymic depressed patients showed platelet-serotonin (pS) + plasma-free serotonin values greater than normal as well as plasma noradrenaline values lower than normal during supine resting period (0'). Conversely, no significant differences were observed in the 0' values of any other of the measured parameters: systolic, diastolic and differential blood pressure (SBP, DBP, DP), heart rate (HR), adrenaline (Ad), dopamine (DA), cortisol, and platelet aggregability between patients and controls. Although patients showed then normal DP reduction at orthostasis (1'), this was not prevented by atropine as it does in controls. Patients but not normals showed significant rises of DBP at orthostasis and exercise (5') periods, which were positively correlated with NA rises. On the contrary, the abnormally raised resting fS values registered in patients showed progressive and significant reductions throughout the test that were negatively correlated with DBP-NA values. Adrenaline did not show the normal 5'-fS peak. The above findings suggest that dysthymics show hypoactivity of the two branches of the sympathetic system (neural + adrenal) along with hyperparasympathetic activity. Furthermore, their low NA + high pS values contrast with the high NA + low pS registered in major depressed subjects.

Adolescent↗

PubMed1994

Multiepitope polypeptide of the HIV-1 envelope induces neutralizing monoclonal antibodies against V3 loop.

A gene encoding a multiepitope polypeptide (MEP) has been synthesized. It contains the information for (1) an 11-amino acid (aa) epitope from the C1 region of gp120 of HIV-1 and (2) 3 epitopes of 15 amino acids each, from the central part of the V3 loop of isolates MN, SC, and WMJII. These four segments are linked by the short spacer peptide AGGGA. This gene was cloned in a plasmid vector and expressed in Escherichia coli as a fusion product with a 62-aa fragment of human IL-2. The recombinant protein TAB1 was purified by washed pellet procedures and reversed-phase HPLC. TAB1 was recognized in ELISAs by 25 of 27 sera from seropositive individuals. Mice were immunized and several hybridomas were obtained. Two of them secrete monoclonal antibodies that react with synthetic peptides from isolates MN, WMJI, WMJIII, and SC with an affinity constant in the range of 10(8) M-1. They also recognized peptides from isolates SF2 and WMJII, but at much lower affinity. The results obtained from peptide ELISAs indicate that the putative epitope recognized by these MAbs lies within the sequence IHIGPGRAFYT. Classic neutralization assays demonstrated that MAb 2C4 neutralizes 50% of the MN isolate at 0.6 micrograms/ml but fails to neutralize IIIB and SF2 strains. The presence of antibodies directed against every one of the component peptides in the sera of rabbits immunized with TAB1 was also documented.

Amino Acid Sequence↗

PubMed1994

Peripheral blood immunological parameters in long-term benzodiazepine users.

Immunodeficiency is frequently invoked as an ethiopathogenetic factor for many somatic diseases. On the other hand, stress, depression, and psychotic disturbances are associated with severe immunological disorders. Taking into account that the benzodiazepines (BZ) are the psychoactive drugs more widely used than any other to treat psychological disturbances, it seems important to elucidate the immuno-enhancing or immunosuppressant potential of such drugs. Our goal was easily reached, since 69% of the outpatients visiting our Institute are chronic BZ consumers and because neurochemical, hormonal, immunological, and psychiatric investigations are routinely performed on all of our patients. In the present study, immune function was investigated on two occasions: while the patient was on active medication and 15 days after discontinuation. We concluded that chronic consumption of BZ provokes significant immunological disorders that should be further investigated. Said disorders could not be linked to a pre-existing affective disease or psychosis, since we only selected those BZ users in whom psychiatric investigations ruled out a past or present history of major psychiatric disease.

Adult↗

PubMed1993

[The nutritional evaluation of cooking fats and oils].

Fatty acids content of locally obtained margarines, shortenings and cooking oils from businesses in Panama were determined by gas chromatographic method. The results found show that all of these oils have a high nutritional value, because of their high unsaturated fatty acid content. The soya oil group is characterized by its high content of linolenic acid (w3), for this reason they are preferably recommended as edible oils. Margarines were classified as "saturated" (high in palmitic acid) and "unsaturated" (high in linoleic acid). Saturated margarines are not very recommendable as edible fats since the high palmitic acid content is a hypercholesterolemic agent. The majority of the shortenings are also rich in palmitic acid.

Chromatography, Gas↗

PubMed1992

Effects of an oral glucose load on plasma neurotransmitters in humans: involvement of REM sleep?

Plasma noradrenaline (NA), adrenaline (Ad), dopamine (DA), platelet serotonin (p5HT), free serotonin (f5HT), glucose, heart rate (HR) and blood pressure (BP) were measured before and after an oral load of glucose (OGTT) in 100 normal humans. One sham-feeding test was performed in every subject 2-3 weeks before OGTT. Aside from glucose rise, significant increases in NA, p5HT and the NA/Ad ratio were registered. No significant changes were observed in Ad, DA, f5HT, HR and BP mean +/- SE values. Significant reductions in the NA/p5HT, Ad/p5HT and DA/p5HT ratios' mean values were registered at 90 and 180 min. Several significant correlations were found amongst plasma neurotransmitters. Very high positive correlations were obtained when NA, Ad and DA were plotted against the ratio of each one of them over p5HT; however, they (r = 0.99) decreased significantly at 90 and 180 min. Upon evaluation of these results we infer that quiescence of adrenal glands occurs during OGTT. Under such circumstances, plasma neurotransmitters are left under the control of a central bipolar system: noradrenergic-parasympathetic. All numerical data strongly suggest that the noradrenergic system predominates at 60, 120 and 210 min, whereas parasympathetic predominance occurs at 90 and 180 min. The fact that the latter is interfered by atropine reinforces this hypothesis. Analyses of correlations also suggest that DA and p5HT probably act as a buffer and modulate the excessive increase in NA plasma levels registered during OGTT.

Adult↗