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Biomedical subjects

J Duclos

Publications and source records attributed to J Duclos.

At least 19 recordsLinked to original sources
PubMed2004

Experimental study and signal analysis in the Lamb wave conversion at a bevelled edge.

This paper deals with a quantitative study of the conversion of a Lamb wave at the bevelled edge of a plate. A harmonic wave (successively the A1 and S0 Lamb modes) is generated using a wedge. The normal displacements at the surface of the plate are measured with a laser vibrometer and used to compute an energy evaluation. In order to determine a good mean value of incident and reflected wave amplitudes, the signals are isolated by a Fourier treatment. Then, the energy flow repartition among the converted modes is computed in both cases and for different values of the bevel angle.

Journal Article↗
PubMed2001

["To Milena" (A essay of narrative medicine)].

Narrative medicine is becoming an increasingly popular way of communicating medical problems. This a letter that the author sends to a recently deceased patient. He describes his apprehensions on the use of invasive forms of diagnosis or treatments and the use of repeated hospital admissions in the context of a chronic and progressive disease. He also discusses the use of methods to "accelerate" death in suffering patients. He finally describes the dignity of his patient to face a chronic and debilitating condition.

Aged↗
PubMed2001

[Hierba del clavo (Geum chiloense) modifying cyclosporine levels: potential risk for transplanted people].

We report a 54 years old male that received a renal allograft without complications. One year after the transplantation, she was receiving cyclosporine doses of 2 to 3 mg/kg and maintained serum levels of 60 to 90 mg/dl. An abrupt increase in cyclosporine serum levels to 469 and 600 mg/dl was noted after 15 months of transplantation. After a careful interrogation the patient admitted the use of Geum chiloense ("hierba del clavo"). Discontinuing this herbal remedy, cyclosporine levels decreased to 55 mg/dl, despite the maintenance of the same cyclosporine dose. The potential side effects of herbal remedies must be borne in mind.

Cyclosporine↗
PubMed2000

[Erythrocytosis post kidney transplantation and its pharmacological treatment: angiotensin converting enzyme inhibitors or angiotensin receptor blockers in a case].

A 35 years old male is presented. Eight months after receiving a renal allograft his hypertension worsened and his packed red cell volume raised to 53.7% Enalapril was started and a 500 ml phlebotomy was performed. In three occasions packed red cell volumes decreased excessively and enalapril was discontinued. Finally, the drug was replaced with losartan, normalizing blood pressure values and stabilizing packed red cell volumes. This case illustrates the different reductions in packed red cell volumes induced by enalapril and losartan. These differences could have a therapeutic relevance.

Adult↗
PubMed1999

[Profession? Physician. Specialty? Internist. Is that all? Yes, that is all].

Different causes have hampered the image and appraisal of internists in Chile and abroad. This article emphasizes and underscores the unique features and conditions that render internists as essential conductors of health care in our society. The disappearance of general internists would be a serious and unmendable loss for the future development of high standard medical care.

Education, Medical↗
PubMed1999

[Evidence based medicine: a strategy that moves closer to or away from internal medicine?].

In the last years, evidence based medicine has been considered a main factor for the diagnostic and therapeutic decisions in medical practice. However, one must consider the complexity of human beings and the difficulties in the interpretation of some results obtained in randomized prospective trials that support this theory. Therefore the importance of clinical experience, rational and logical medical thinking and facing patients as individuals must prevail at the moment of complex medical decisions.

Evidence-Based Medicine↗
PubMed1998

Identification of an elicitin gene cluster in Phytophthora cinnamomi.

Elicitins are a group of highly conserved proteins secreted by species of Phytophthora and a species of the related genus Pythium, Pythium vexans. Some of these proteins act as inducers of the necrotic hypersensitive-like response and the associated systemic acquired resistance phenomenon, in some species. We cloned and characterised the cinnamomin-beta and -alpha genes and two related elicitin genes from Phytophthora cinnamomi. These four open reading frames (ORFs) are clustered in tandem pairs. Two out of these four genes present homologies with the basic and acidic elicitin groups; but the two others encode, if expressed, elicitin isoforms exhibiting homologies with the class II of highly acidic elicitins.

Algal Proteins↗
PubMed1997

[Massive inferior vena cava thrombosis associated with protein C deficiency. Clinical case].

Inferior vena cava thrombosis is infrequent and in 30% of cases, the potential cause is an alteration of the natural anticoagulant protein system. We report a 18 years old male with an inferior vena cava thrombosis that was associated to a protein C deficiency. He was successfully treated with an infusion of intravenous streptokinase during 30 hours and intravenous heparin during 10 days, followed by oral anticoagulation therapy.

Adolescent↗
PubMed1997

[Renovascular hypertension and abdominal bruit in a case: has its interpretation modified technology?].

A lateral abdominal bruit is considered an important finding for the detection of renovascular hypertension. However, the precision and accuracy of new techniques such as angiography, Doppler ultrasound and studies with radioisotopes have changed its value and clinical interpretation. We report a 75 years old woman with a bilateral renal artery stenosis in whom a bruit was heard over the artery that did not contribute to the genesis of hypertension and the significant arterial stenosis causing hypertension was silent. This particular situation could lead to erroneous clinical decisions.

Abdomen↗
PubMed1995

[Hepatitis C virus viremia and Herpes zoster virus infection in a patient in hemodialysis treated with erythropoietin].

Hepatitis C virus infection in chronic hemodialysis patients is associated with several unresolved problems. We report a 85 years old female patient in chronic hemodialysis and treated with erythropoietin, that during the course of an Herpes zoster, presented severe malaise, weight loss and muscle weakness. Two weeks later, a slight rise in serum transaminases was detected. The patient had negative antibodies for HIV and hepatitis C virus and negative hepatitis B surface antigen. A PCR test was positive for serum hepatitis C virus RNA. The patient's condition deteriorated and she died 7 days after admission. Erythropoietin administration, whose immunosuppressive effect has been reported previously, could have influenced the dismal outcome of this patient.

Aged↗
PubMed1995

[Erythropoietin and transfusions in patients with anemia of chronic renal failure origin : an update view].

Aiming to know the factors that influenced the use of erythropoietin (EPO) in chronic hemodialysis patients, we retrospectively studied 82 patients (41 male), of whom 15 received EPO. No differences, between patients receiving or not receiving EPO, were found in age (46.9 +/- 25 and 57 +/- 13 years respectively), male/female ratio (9/6 and 32/35 respectively), time on dialysis (36.4 +/- 25.6 and 36.8 +/- 31.8 months respectively), dialysis hours (3.19 +/- 0.6 and 3.33 +/- 0.39 h respectively) and proportion of diabetics (6.6 and 20.8% respectively). Prior to EPO use and compared to untreated patients, treated patients were transfused with a higher frequency (60 vs 22%) and with more units/patients/years (0.12 vs 0.08). Hemoglobin levels at the start of the treatment was similar in treated and untreated patients (8.4 +/- 1.46 vs 8.78 +/- 1.97 g/dl). EPO was indicated in 11 patients due to general symptomatology associated to anemia and in 4 due to cardiac failure or angina. We conclude that EPO treatment is indicated in approximately 18% of patients in dialysis. An adequate dialytic treatment may achieve optimal hemoglobin levels with minimal transfusion requirements and without need of EPO, thus reducing costs.

Adult↗
PubMed1995

[Hospitalization in the elderly patient: a risk or benefit?].

The aim of this work was to study the impact of hospital admission on functional status of elders. Eighty six patients (63 male) aged 73 +/- 4 years old admitted to the Internal Medicine Service of a public hospital were studied. Functional status was measured on admission, discharge and 15 days after discharge using the Northwestern Functional Status Review Instrument. Fifteen patients died during hospital stay. Functional status improved in patients admitted with disordered consciousness, in those admitted due to neurologic disorders, in those with less than two chronic diseases, in those whose disease cured during hospitalization and those that did not acquire new disease during admission. Prolonged hospitalizations of more than 13 days were associated with functional status worsening. It is concluded that functional status or elders does not always deteriorate during hospital admissions.

Aged↗