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Biomedical subjects

E Ramos

Publications and source records attributed to E Ramos.

At least 109 records · Page 6Linked to original sources

Large-scale production in Pichia pastoris of the recombinant vaccine Gavac against cattle tick.

A gene coding for the Bm86 tick protein was recently cloned, expressed in Pichia pastoris and shown to induce an inmunological response in cattle against ticks. Moreover, the Gavac vaccine (Heber Biotec S.A., Havana, Cuba), which contains this recombinant protein, has proved to control the Boophilus microplus populations under field conditions. This paper reviews the development and large-scale production of this vaccine, the efficacy of the resulting product and the strategy followed in designing its production plant. The production plant fulfills biosafety requirements and GMP.

Animals↗

Normal pancreastatin-like and increased post-glucose insulin levels in young offspring of insulin-resistant non-obese essential hypertensive patients.

Pancreastatin is a regulatory peptide known to inhibit insulin secretion and insulin action with a glycogenolytic effect in the liver. This peptide is present in and secreted by many endocrine and chromaffin cells. Abnormalities of glucose, insulin and lipoprotein metabolism are common in patients with hypertension, as well as their first-degree relatives. We have recently studied a group of non-obese hypertensive subjects in which pancreastatin-like levels were increased compared with controls, and correlated with norepinephrine levels. We hypothesized that pancreastatin alongside the sympathoadrenal system might have a part in the insulin resistance of these patients, and this metabolic syndrome could play a role in the pathogenesis and complications of hypertension. In this article, we studied the normotensive offspring of these nonobese hypertensive patients and looked for metabolic abnormalities as well as plasma pancreastatin, glucagon and catecholamine levels. The subjects were separated into two groups: (1) offspring from non-insulin-resistant patients and (2) offspring from insulin-resistant patients. We found that after an intravenous glucose load, offspring from insulin-resistant patients were already hyperinsulinemic, although glucose clearance was normal, suggesting an early alteration in insulin sensitivity, whereas pancreastatin and catecholamine levels were normal compared with matched controls. However, offspring from non-insulin-resistant patients had no differences with controls. These results suggest that pancreastatin and catecholamines may not play an important role in triggering insulin resistance, although they may be important once the syndrome is established.

Adult↗

Intraoperative colonic lavage and primary anastomosis in peritonitis and obstruction.

BACKGROUND: The surgical management of left colonic emergencies has evolved in the past few decades. Recently, there has been increasing interest in resection with primary anastomosis in selected cases. The aim of this study was to evaluate the differences in outcome in patients with peritonitis or obstruction treated by resection, on-table lavage and primary anastomosis of the left colon. METHODS: Between January 1992 and August 1995, 212 patients underwent emergency operation for a distal colonic lesion: 97 presented with peritonitis, 113 with obstruction and two with other indications. Intraoperative colonic lavage was performed in 37 patients with obstruction and in 24 with an acute intra-abdominal inflammatory process. RESULTS: The postoperative mortality rate was 5 per cent. The incidence of clinical anastomotic leakage was 5 per cent. Wound infection was observed in ten patients (16 per cent), more often in those with peritonitis (P = 0.03). The overall mean(s.d.) hospital stay was 15(9) days. CONCLUSION: Resection, on-table lavage and primary anastomosis constitute the operation of choice for selected patients with left colonic emergency.

Adult↗

Myosin phosphorylation by human cdc42-dependent S6/H4 kinase/gammaPAK from placenta and lymphoid cells.

The p21-activated kinase (PAK) family includes protein phosphotransferases regulated by the GTPases rho, rac, and cdc42. Sequence homology, activation mechanism, and substrate specificity suggest that the well-characterized human placenta S6/H4 kinase is a member of this family. In these studies, S6/H4 kinase purified to homogeneity from human placenta was activated in vitro by cdc42-GTP, or protease incubation and MgATP-dependent autophosphorylation. The cdc42-activated enzyme demonstrated an Mr 60,000, and shares sequence homology with the gammaPAK family. Antipeptide antibodies against one of the autophosphorylation site sequences recognized a single p60 protein in the purified placenta preparation or Jurkat cell extracts. An autophosphorylated Mr 40,000 protein, previously identified as the catalytic domain of the enzyme, was also detected by the antibody after protease activation. Crude PAK60 obtained from Mono Q chromatography of Jurkat cell extracts and purified placenta enzyme catalyzed phosphorylation of histone H4 and myelin basic protein as well as a variety of synthetic peptides previously identified as S6/H4 kinase substrates. In addition, Jurkat myosin II and the regulatory myosin light chain were phosphorylated by the Jurkat and placenta gammaPAK. Synthetic peptides were used to demonstrate that the site of light chain phosphorylation occurs at the serine which results in ATPase activation. The data suggest that human gammaPAK may regulate cell motility by a GTP-dependent and calcium-independent mechanism.

Cell Cycle Proteins↗

[Risk factors for myocardial infarct: a case-control study in Oporto, Portugal].

A case-control study of coronary heart disease (CHD) was conducted in Oporto, Portugal. The cases series consisted of 100 consecutive patients with first time acute myocardial infarction who were admitted to the Coronary and Intermediate Care Units of a major teaching hospital. The community controls were 198 individuals without evidence of CHD by the Rose questionnaire and electrocardiography, selected by random digit dialing, with a participation rate of 70%. Data was collected by trained interviewers using a structured questionnaire and blood samples were obtained for selected laboratory data. The main analysis was made through unconditional logistic regression with calculations of odds ratios (OR). Age, OR: 1.5 (95% CI: 0.8-2.9), male gender, OR: 6.7 (3.6-12.3), family history of premature CHD, OR: 2.4 (1.4-4.3), diabetes, OR: 3.4 (1.6-7.4), antecedents of hypertension, OR:1.9 (1.1-3.1), history of high cholesterol levels, OR: 2.3 (1.4-3.9), high levels of physical activity, OR: 2.0 (0.9-4.1) and tobacco smoking, OR: 8.3 (3.8-18.5) were significant risk factors of acute myocardial infarction. After controlling for demographic variables and for the mutual confounding effects of the risk factors, the investigated factors that remained significantly associated with the risk of developing acute myocardial infarction were male gender, OR: 17.3 (4.8-62.3), family history of CHD, OR: 3.6 (1.4-9.6), diabetes, OR: 4.2 (1.0-18.1), high cholesterol levels OR: 2.7 (1.2-6.1) and smoking habits, OR: 7.7 (1.8-32.4). A negative association with high education levels was significant after controlling for all the variables, OR: 0.01 (0.01-0.5).

Adult↗

[Stereotactic surgery in Parkinson's disease].

Stereotactic surgery for Parkinson's disease (PD) has regained interest due to the recently described hyperactivity of the subthalamic-pallidal pathway. Many patients suffering from complications associated with the chronic use of levodopa may benefit from surgical treatments. There are different surgical targets and techniques (ablative and deep brain stimulation). The choice of one particular target and technique relies on the clinical symptoms of the patient. The risk/benefit ratio of surgery is related to the careful selection of patients and the technical accuracy. Intraoperative microrecording is considered the best method to avoid side effects and partial results. A series of patient's selection and follow-up assessment criteria are proposed.

Follow-Up Studies↗

delta-Aminolevulinic acid uptake is mediated by the gamma-aminobutyric acid-specific permease UGA4.

There is evidence that delta-aminolevulinic acid (ALA), a precursor of porphyrin biosynthesis, and gamma-aminobutyric acid (GABA) would be incorporated into yeast cells by a common permease. The purpose of this work was to confirm this hypothesis and to identify the shared permease. The transport of GABA in Saccharomyces cerevisiae is mediated by three permeases: the general amino acid permease (GAP1), the specific proline permease (PUT4) and a fairly specific GABA permease (UGA4). To determine which of these permeases is also involved in ALA uptake, ALA and GABA incorporations were measured in strains lacking GAP1, UGA4 or GAP1 and UGA4 permeases. Results indicated that ALA is mainly incorporated by UGA4. This was also confirmed by regulatory studies, since ALA uptake was induced by GABA, and it is well known that UGA4 permease is induced by GABA. On the other hand, ALA did not induce the synthesis of this permease. Therefore, we demonstrate here that ALA, which cannot be used as a nitrogen source, is uptaken by S. cerevisiae cells mainly using a permease encoded by a gene subjected to a regulation typical of several nitrogen genes.

Aminolevulinic Acid↗

[Options in the surgical treatment of diffuse cavernous hemangioma of the rectum].

Cavernous haemangioma of the rectum is an unusual hamartomatous malformation. Patients usually present with painless massive rectal bleeding that generally begins at an early age and frequently surgery is necessary. To avoid abdominoperineal resection of the rectum in these patients, a procedure of colo-anal sleeve anastomosis, that includes a large rectal mucosectomy, has been described. However, in our opinion, if affectation of other pelvic organs can been excluded by MRI, it is easier to do a conservative proctectomy with colo-anal anastomosis. We present a case in a seventeen years old patient.

Adolescent↗

[Effect of the treatment with amlodipine on left ventricular hypertrophy in hypertensive patients].

BACKGROUND: Left ventricular hypertrophy (LVH) is one of the physiopathological effects of hypertension and one of the main risk factors for sudden death, myocardial infarction and congestive heart failure. Drugs to treat hypertension must not only reduce blood pressure, but also modify the facts which lead to ventricular hypertrophy. This study has been designed to assess the effect of amlodipine, a calcium-antagonist, on LVH in hypertensive patients. METHODS: 20 hypertensive patients (mild to moderate, both sexes, mean age 45.0 yr) were included in a single-blind study. After an initial, four weeks placebo period, active treatment was given (amlodipine 5 mg a day). Dose titration was made after 4-8 weeks to 10 mg a day if necessary and continued until the end of the study. Systolic (SBP) and diastolic blood pressure (DBP), as well as pulse rate (PR) and adverse events were recorded at every visit. Blood and urine analysis, catecholamine, plasmatic renin activity and Mode M echocardiography were made at the beginning and the end of the study. RESULTS: Only one patient was excluded. SBP and DBP showed a significantly fall (p < 0.001). In 80% of patients DBP fell under 90 mm Hg. Every echocardiographic parameter, but left ventricular diastolic dimension, showed significantly reductions at the end of the study: septum thickness (p = 0.001), posterior wall thickness (p = 0.001), left ventricular systolic dimension (p = 0.014), wall relative thickness (p = 0.015), shortening fraction (p = 0.009), left ventricular mass (p = 0.001) and corrected left ventricular mass (p = 0.001). Blood parameters did not modify. CONCLUSIONS: Amlodipine has a beneficial effect on LVH and also is an effective and safe drug to treat mild to moderate hypertension.

Amlodipine↗

Acute pancreatitis after liver transplantation: incidence and contributing factors.

In order to assess the incidence and possible predisposing and contributing factors in the development of acute pancreatitis after liver transplantation, we reviewed the medical records of all 1832 adult patients who underwent 2161 orthotopic liver transplantation (OLTx) procedures in our center between January 1987 and September 1992. Of these patients, 55 (3% incidence) developed clinical pancreatitis and 247 (13.4% incidence) developed hyperamylasemia (biochemical pancratitis). Overall mortality in cases of clinical pancreatitis was 63.6%. The mortality in cases of hyperamylasemia was similar to that found in the general liver transplant population (i.e., 23%). A strong correlation was found between pancreatitis after liver transplantation and end-stage liver disease due to hepatitis B (30% of the cases, P = 0.00001). Extensive surgical dissection around the pancreas (P < 0.05), the type of biliary reconstruction following liver transplantation (P < 0.05), and the number of liver grafts received by the same patient (P = 0.00001) appeared to be possible contributing factors as did the duration of venovenous bypass and the quantity of IV calcium chloride administered intraoperatively.

Acute Disease↗

Control of Boophilus microplus populations in grazing cattle vaccinated with a recombinant Bm86 antigen preparation.

Current methods for the control of cattle tick Boophilus microplus infestations are not effective and the parasite remains a serious problem for the cattle industry in tropical and subtropical areas. Recently, we developed a vaccine against B. microplus employing a recombinant Bm86 (rBm86) antigen preparation (Gavac, Heber Biotec) and it was shown to induce a protective response in vaccinated animals under controlled conditions. Here we show that, under field conditions in grazing cattle, the vaccine is able to control B. microplus populations. Two parasite-free farms were employed for the study. In the first farm, animals were vaccinated with the recombinant vaccine, while, in the second, animals received a saline injection in adjuvant. After immunization, animals were artificially infected and the infestation rate was recorded. Over the 33 weeks of the experiment, the infestation rate was lower in the vaccinated group compared with the control group. At the end of the experiment it was necessary to use chemicals in the control farm after serious losses in production and animals.

Animals↗

Caroli's disease complicating pregnancy.

We describe two pregnancies in the same patient with Caroli's disease (congenital dilatation of the intrahepatic bile ducts). The first pregnancy was uneventful concerning the maternal Caroli's disease. The second pregnancy highlights the serious and potentially lethal complications of an acute episode to both the fetus and mother. The patient had acute ascending cholangitis, disseminated intravascular coagulopathy, and septic shock. Fetal distress necessitated delivery by cesarean section. The mother's postoperative course required prolonged critical care and interdisciplinary consultation. Both mother and neonate survived. We present the first report of Caroli's disease in pregnancy and review implications to the pregnant patient.

Adult↗