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Biomedical subjects

A Mesa

Publications and source records attributed to A Mesa.

At least 19 recordsLinked to original sources
PubMed2000

Endoluminal treatment of acute aortoiliac thrombosis.

A 55-year-old woman presented with an ulcerative stenosis of the distal abdominal aorta. She was scheduled to undergo percutaneous aortic balloon angioplasty the next day. Upon readmission, however, she complained of lower abdominal pain. A second abdominal angiogram revealed thrombosis of the infrarenal abdominal aorta and left common iliac artery. This was treated by means of simple transcatheter thrombus aspiration and thrombolysis, followed by stenting of the aorta.

Angiography↗
PubMed1999

First radiotherapy of human metastatic brain tumors delivered by a computerized tomography scanner (CTRx).

PURPOSE: This Phase I study was designed to evaluate the computed tomography (CT) scanner as a device for radiation therapy of human brain tumors (CTRx). This first use in humans of a modified CT for treatment was founded on extensive research experience with canine tumors. An additional objective was to increase the therapeutic radiation dose to tumors compared to normal tissue by concentration of infused contrast material in tumors, an effect available at diagnostic x-ray energies but not at megavoltage energies. METHODS AND MATERIALS: A small metastatic brain tumor in each of eight patients received 3-5-weekly fractions of 5 Gy equivalent per fraction from a CT scanner modified to deliver radiation therapy. In each patient, one additional tumor, lying completely outside the volume treated by CTRx, served as a control. The tumor receiving CTRx was treated after infusion of iodinated x-ray contrast media (CM) for dose enhancement. Many of these patients also received conventional 40 Gy whole brain radiation, before, during, or after CTRx treatment. RESULTS: None of the patients showed adverse reactions to the CM or necrosis of the normal brain from the CTRx boost radiation. Monte Carlo calculations of the radiation dose distributions in a model tumor showed that the CTRx irradiation of tumors carrying 10 mg or more of iodine per gram of tumor was as good or better than the dose distribution from conventional 10-MV X-rays. The treated tumor in two of the patients vanished after four treatments, whereas a control tumor in one patient remained constant and grew 4-fold in another patient. CONCLUSION: The CTRx concept effectively combines a modified CT scanner as a diagnostic device, as a simulator dedicated to radiotherapy, and as a treatment machine. Thus, CTRx could be very useful for radiation oncologists in controlling CM-enhanced and other small brain tumors.

Brain Neoplasms↗
PubMed1999

Long-term prognosis in women with normal dobutamine stress echocardiography.

Although the long-term prognosis for patients with a normal dobutamine stress echocardiographic result is good, most studies have focused on men. We assessed the long-term cardiac prognosis for women by reviewing the cases of 100 women who underwent dobutamine stress echocardiography for suspected coronary artery disease and found that women with a normal result have an excellent long-term cardiac prognosis.

Coronary Disease↗
PubMed1999

Left ventricular diastolic function in normal human pregnancy.

BACKGROUND: Little information is available about changes in left ventricular diastolic function during pregnancy. We used mitral inflow and pulmonary venous flow profiles to evaluate left ventricular diastolic function in 37 healthy pregnant women 26 to 41 years old (mean, 32 years). METHODS AND RESULTS: Echocardiographic studies were performed at the end of each trimester. Eight subjects (control group) underwent similar testing 1 to 3.5 months (mean, 1.7 months) postpartum. During pregnancy, the cardiac output increased significantly as a result of an increased heart rate and, to a lesser degree, stroke volume. Significantly decreased systemic vascular resistance and increased left ventricular mass were also noted. Peak mitral flow velocity in early diastole (E) increased 13. 3% during the first trimester and remained at the high end of normal throughout pregnancy. Peak A-wave velocity (A) increased maximally in the third trimester. Compared with control subjects, first-trimester subjects had a significantly increased E/A ratio. The ratio subsequently decreased, reflecting the augmented A-wave velocity. Pulmonary venous peak systolic forward flow velocity increased, peaking in the second trimester (nonsignificant), but returned to baseline levels postpartum. The pulmonary venous diastolic time-velocity integral decreased significantly from the first to the third trimester. Peak pulmonary venous reverse flow velocity at atrial contraction increased significantly, without being markedly changed in duration. CONCLUSIONS: Pregnancy, a chronic, natural volume-overload state, has important effects on hemodynamic and echocardiographic variables. Based on pulmonary venous flow and left ventricular inflow velocities, our results provide a standard reference concerning diastolic filling dynamics by trimester.

Adult↗
PubMed1999

Phaeohyphomycosis in kidney transplant patients.

Dematiaceous fungi are being increasingly recognized as pathogens in organ transplant recipients. This investigation reports five cases of subcutaneous phaeohyphomycosis that occurred in five kidney transplant recipients in the Renal Unit at the San Vicente de Paul Hospital, Medellin, Colombia. Fungi of the genus Exophiala were isolated in three cases, but the agent was not identified in two cases. Physicians are likely to develop increased awareness of the clinical manifestation of infection with the dematiaceous fungi as the population of immunocompromised hosts continues to grow.

Antifungal Agents↗
PubMed1997

[Myelographic diagnosis of an epidural arterio-venous fistula].

INTRODUCTION: Epidural arterio-venous fistulae are a little known clinical condition. They are probably commoner than is thought, since diagnosis and angiographic demonstration are difficult. CLINICAL CASE: We present the case of a 49 year old man with the clinical features of chronic myelo-radiculopathy with episodes of intermittent medullary claudication. This shows the use of myelography, which in certain cases allows clear detection of vascular structures which might otherwise pass unnoticed. CONCLUSIONS: One should think of this condition when compatible features are found and there is no other diagnosis, since if confirmed by myelography and/or magnetic resonance prior to angiographic study, it may benefit from embolization, which is an effective treatment for this.

Arteriovenous Fistula↗
PubMed1996

Utility of transesophageal echocardiography in infective endocarditis. A review.

Despite recent diagnostic and therapeutic advances, infective endocarditis continues to be a very serious illness, with high patient morbidity and mortality rates. The diagnosis of infective endocarditis has been based primarily on clinical signs and positive blood cultures. Echocardiography is currently recognized as the technique of choice for the detection of valvular vegetations, which are the hallmark of endocarditis. We briefly review the use of echocardiography in the diagnosis of suspected infective endocarditis, with emphasis on transesophageal echocardiography. High-resolution imaging of the cardiac valves with transesophageal echocardiography has proved to be invaluable in the management of infective endocarditis.

Abscess↗
PubMed1993

Synaptonemal polycomplexes in spermatids: a characteristic trait of Orthoptera?

Spermatogenesis was analysed in a cricket, Eneoptera surinamensis (Gryllidae, Orthoptera), using ultrathin serial sections and transmission electron microscopy. Special attention was placed on documentation of the development and structure of synaptonemal polycomplexes (PCs) within spermatid nuclei. Pachytene spermatocytes showed the usual tripartite synaptonemal complexes in the nuclear lumen. PCs were situated close to chromosomes at the periphery of spindles in prometaphase I spermatocytes, where microtubule density was low. The PCs are probably incorporated into the daughter nuclei of both meiotic divisions by adhesion to chromosomes. Finally, PCs end up within spermatid nuclei. Analysis of serial sections through three nuclei of young spermatids revealed at least one PC within each. The PCs were intimately attached to an electron-dense spherical nuclear body. This topographical correlation was confirmed through inspection of random sections. The PCs may have an affinity to the spherical bodies. In more developed spermatids, PCs and nuclear bodies were missing. Disassembly products of the PCs may play a role in spermatid maturation. In a series of other Orthoptera species, PCs have been reported to occur in the cytoplasm or the nuclei of spermatids. In most other systematic groups, PCs do not form at all or disassemble earlier. The presence of PCs in young spermatids, therefore, seems to be typical of Orthoptera.

Animals↗
PubMed1977

Effect of caerulein on gamma-glutamyl transpeptidase and alkaline phosphatase in the duodenal juice in chronic pancreatitis.

During infusion of caerulein, the output of gamma-glutamyl transpeptidase and biliary alkaline phosphatase is significantly more increased in chronic pancreatitis patients than in normal subjects. The presence of the gall-bladder is necessary to observe this effect of caerulein. It is not related to the discharge of large amounts of both enzymes by the diseases pancreas.

Alkaline Phosphatase↗