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Biomedical subjects

V Lopez-Majano

Publications and source records attributed to V Lopez-Majano.

At least 19 recordsLinked to original sources
PubMed1991

Bone scan as a stratification variable in advanced prostate cancer.

The serial technetium 99 (99Tc) bone scans of 76 patients with Stage D-2 prostate cancers were reviewed. Sites of metastases in skeletal areas in decreasing order were vertebrae, ribs, pelvis, long bones, and skull. Patients with one or two involved skeletal areas had a significantly longer progression-free interval and survival time than patients with three or more bony areas of uptake. Bone scans might be used as a stratification variable in future prospective clinical trials of Stage D-2 prostate cancer.

Aged↗
PubMed1990

Pulmonary blood flow distribution in erect man in air and during breathhold diving.

We used intravenously administered 99mTc-labelled macroaggregates and a gamma camera attached to a computer for measuring distribution of pulmonary blood flow per unit lung volume in eight healthy subjects sitting erect in air and also during breathhold diving to 1 or 10 m of depth. We measured distribution of perfusion in the supine position and substituted regional lung volume with regional perfusion in the supine for calculating regional perfusion per lung volume erect in air and during diving. The perfusion per unit lung increased rectilinearly down the lung in subjects below 30 years of age but decreased in the lowermost regions in older subjects. This decrease showed a strong correlation to closing capacity. An age-related decrease in transpulmonary pressure may influence both basal perfusion and closing capacity. During submersion, perfusion became equal in all regions with the exception of the lung apex which became hyperperfused. Close to the diaphragm, small inconsistent changes were noted. Redistribution was the same at surface (1 m of depth) with the lung volume being close to total lung capacity and at 10 m of depth when lung volume was compressed to functional residual capacity. During breathhold diving, high intrapulmonary blood volume and pressure became more important for blood flow distribution than gravity or lung volume, while differences in regional hypoxic vasoconstriction and in transpulmonary pressure seem to explain interindividual variation.

Adult↗
PubMed1988

Gallium 67 scintigraphy in glomerular disease.

To evaluate the diagnostic usefulness of gallium 67 scintigraphy in glomerular disease, 45 patients with various glomerulopathies, excluding lupus nephritis and renal vasculitis, were studied. Persistent renal visualization 48 hours after the gallium injection, a positive scintigram, was graded as + (less than), ++ (equal to), and +++ (greater than) the hepatic uptake. Positive scintigrams were seen in ten of 16 cases of focal segmental glomerulosclerosis, six of 11 cases of proliferative glomerulonephritis, and one case of minimal change, and one of two cases of membranous nephropathy; also in three of six cases of sickle glomerulopathy, two cases of diabetic neuropathy, one of two cases of amyloidosis, and one case of mild chronic allograft rejection. The 25 patients with positive scans were younger than the 20 with negative scans (31 +/- 12 v 42 +/- 17 years; P less than 0.01), and exhibited greater proteinuria (8.19 +/- 7.96 v 2.9 +/- 2.3 S/d; P less than 0.01) and lower serum creatinine values (2 +/- 2 v 4.1 +/- 2.8 mg/dL; P less than 0.01). The amount of proteinuria correlated directly with the intensity grade of the gallium image (P less than 0.02), but there was no correlation between the biopsy diagnosis and the outcome of the gallium scan. It was concluded that gallium scintigraphy is not useful in the differential diagnosis of the glomerular diseases under discussion. Younger patients with good renal function and heavy proteinuria are likely to have a positive renal scintigram regardless of the underlying glomerulopathy.

Adult↗
PubMed1987

Use of gallium, colloids and pertechnetate as carriers of drugs for selective action.

A pharmacodynamic hypothesis is formulated which considers using substances such as gallium, with predilection to locate in neoplasm and inflammation, to increase the therapeutic effect in the disease-affected area. Drugs carried by a colloid can be directed to the liver, IDA derivatives which are metabolized by hepatocytes can also be used as transporters of drugs to the liver and to the hepatobiliary tree because they are eliminated through that route. In diseases which affect the blood-brain barrier substance such as pertechnetate can be used as drug carriers. Pertechnetate and other substances which are eliminated through the kidneys may be used as carriers for drugs in certain renal diseases. This therapeutic approach can be used if the amount of carrier is not toxic to the target organ, if the time of action is sufficient and if the bond between drug and carrier is strong.

Brain↗
PubMed1987

Serum angiotensin-converting enzyme (SACE) activity as an indicator of total body granuloma load and prognosis in sarcoidosis.

The relationship between the level of serum angiotensin converting enzyme (SACE) and the total body granuloma load in patients with sarcoidosis was studied in two groups using SACE levels and total body gallium67 scans. The study group consisted of 22 patients with SACE levels greater than or equal to 100 U/ml (EH-SACE group) and the control group consisted of 24 patients consecutively diagnosed to have sarcoidosis in a one year period with SACE level of less than 80 U/ml. The average number of organs involved in the EH-SACE group was 3.9 +/- 1 compared to 2.3 +/- 1 in the control group (p less than 0.0001). The incidence of extra pulmonary organ involvement in the EH-SACE group was 2.2 +/- 1 organs compared to 1.0 + 0.8 in the control group (p less than 0.0002). The SACE level was correlated with the number of organs involved for all patients with sarcoidosis (r = .55; p less than .0001). Following corticosteroid therapy for 39 +/- 41 weeks the SACE dropped to 64 +/- 45 units in the EH-SACE group. But it took only 13 +/- 10 weeks to normalize the SACE level to 27 +/- 9 units in the control group. The EH-SACE group patients were followed for 114 +/- 64 weeks and 73% of them still have active sarcoidosis requiring repeated cycles of corticosteroid therapy, while after 42 +/- 23 weeks of follow up only 10% of patients from the control group were still on therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex Hormones↗
PubMed1985

Hemoptysis and pulmonary artery agenesis: case report.

The combination of a pulmonary scintigram using radioactive labeled albumin macroaggregates (MAA) and a study of the circulation in the bronchial artery was performed in one patient. This noninvasive methodology showed that there was increased circulation to the vascular territory of the lung in which the pulmonary artery was missing. This could have resulted from abnormal communications between the bronchial artery and the pulmonary vessels or an increased blood supply to the right lung from bronchial arteries arising from the aorta. The absence of pulmonary circulation in the right lung was proved by the absence of radioactivity in the right lung after an intravenous injection of labeled albumin MAA.

Adult↗
PubMed1985

Nuclear medicine in the diagnosis of cardiac contusion.

In 16 patients with blunt trauma to the chest, the role of cardiovascular nuclear medicine was evaluated using anterior chest flow assessment, with first-pass ejection fraction of left and right ventricles and 99mTc-pyrophosphate scintigraphy. The radiopharmaceutical used was pyrophosphate, labelled with approximately 20 mCi 99mTc. The anterior chest flow and first-pass ejection fractions were initially obtained during the injection of 99mTc-pyrophosphate and were followed up 3 h later by anterior, LAO 45 degrees, and left lateral views of the chest, using an LFOV gamma camera with a data processor. The results were compared with serial cardiac enzymes studies, electrocardiograms and echocardiograms. Of the patients, 77% showed scintigraphic evidence of cardiac contusion. The intensity of activity varied from grades I to II; five patients had abnormal echocardiographic findings. Only two had abnormal ejection fractions, and one patient had evidence of left ventricular aneurysm along with poor ventricular performance. Cardiac enzymes were found to be the least helpful. Electrocardiograms, though non-specific for myocardial damage, were abnormal in 62% of the patients. Eleven of our patients had both abnormal ECG and increased PYP uptake. Even though there is no agreement as to which noninvasive parameter is more sensitive in the diagnosis of myocardial contusion, 99mTc-pyrophosphate scintigraphy, in conjunction with ECG, seems promising in this respect.

Contusions↗
PubMed1979

Neoplasm localization with radionuclides.

Tumor scintigraphic localization of neoplasms can be done in two ways: indirectly and directly. The first method shows alternations of the normal structure of the organ, such as "cold lesions" in liver and thyroid. Abnormalities in function as increased permeability of the blood barrier results from abnormal deposition of the radionuclide in the brain scintigram of a patient with neoplasm. Increased focal areas of uptake of bone-seeking radionuclides are very characteristic of metastases. The direct methods depend on preferential uptake of the radionuclide by the neoplastic tissue resulting from altered metabolism (e.g. Se-75). Other agents such as Gallium-67 have affinity for neoplasms. Another approach is to use antineoplastic agents and radioactive antibodies which will localize in the tumor. At this stage the most useful neoplasm seeking agents are Gallium-67 citrate and 111In-Bleomycin, even though infections can give false positives. The possibility should be considered of enhancing the uptake of radionuclides by neoplastic cells using increased O2 concentration.

Animals↗
PubMed1979

Size of arteriovenous anastomoses in the dog femoral circulation.

Radioactive plastic microspheres 50 and 200 micra in diameter labeled with Ytterbium169 were used to study distribution in the femoral circulation of living dogs under general anaesthesia. Shunting was demonstrated because radioactivity was detected in the lungs after intraarterial injection of 50 micra microspheres. When the size of the microspheres injected was 200 micra no radioactivity was detected over the lungs. This indicates that the arteriovenous anastomoses are smaller than 200 micra, they are probably located in the skin because there was less radioactivity in the skin after intrafemoral injection of the 50 micra microspheres than when the injected microspheres were 200 micra in diameter.

Animals↗
PubMed1978

Indications for pulmonary function testing.

Pulmonary function testing is needed to determine the pathophysiology present in the patient with cardiopulmonary disease. Blood gases and pH should be obtained during emergency situations and during cranial, thoracic, and extensive cervical or abdominal surgery. Lung function tests can be divided in global such as spirometry and diffusing capacity which study the ventilation and transfer of gases and regional determinations of ventilation and perfusion. Both types of tests complement each other and should be used together. The spirometry should consist at least of determination of the vital capacity and is determined in the first second to ascertain if there is obstructive lung disease. Some tests such as flow-volume curves, alveolar-arterial gradients and closing volume are very useful to detect early pulmonary disease before any symptoms or findings are present. This is probably one of the most important medical indications for pulmonary function testing. Before certain types of surgery pulmonary function testing is indicated; if the spirometry and diffusing capacity tests are normal, there is no pulmonary contraindication for the planned surgery. In chest surgery if there is significant compromise of the spirometry and diffusing capacity regional lung function tests are indicated to study the pathophysiology at regional level, thus trying to circumscribe the lung resection to the diseased areas.

Blood Gas Analysis↗
PubMed1978

Incidence of pulmonary embolism.

During the last 5 years in a community hospital of 219 beds, the most common cause of death (primary and secondary or contributory) was pulmonary embolus. In the US fatal pulmonary emboli occur in 5 patients for 1,000 inpatients, nonfatal pulmonary embolism in 20 patients per 1,000 inpatients, about 142,000 patients suffer fatal pulmonary emboli and 568,000 suffer nonfatal pulmonary emboli each year. In 422 autopsies 93 patients (21%) have pulmonary emboli undiagnosed during the patient's life time. In comparing with other statistical studies, about 21% represent the death rate of patients treated for pulmonary emboli if the diagnosis is previously made. On the basis of this observation the incidence of pulmonary emboli and thrombosis of the lower limbs appears to be about the same in community and the university hospitals, disregarding if the patients are having the highly skill care or are treated by the general practitioner without the sophistication of expensive technology.

Adult↗
PubMed1978

Incidence of pulmonary embolism in deep venous thrombosis.

Abnormal radionuclide phlebograms were found in 65 patients in whom simultaneous-perfusion lung scintigrams and phlebograms were performed. All these patients were on adequate treatment with heparin for deep venous thrombosis. In 28% of the cases, the diagnosis of pulmonary embolism was made because they had abnormal perfusion lung scans with normal chest radiograph and clinical symptoms of pulmonary embolism.

Adolescent↗
PubMed1976

Quantification of lung scintigrams.

A simple method of obtaining objective information consists in recording numerical information of the counts in each lung. Albumin macroaggregates labeled with 99Tc(m) and a gamma camera with a data processor were used.

Humans↗
PubMed1976

Early diagnosis of interstitial fibrosis.

2 cases of interstitial fibrosis of the Hamman-Rich type are presented. The patients were symptomatic, but had normal X-rays. They were suspected of having interstitial infiltration by pulmonary function tests. Diagnosis was confirmed by lung biopsy. Pulmonary function tests, especially the study of elastic properties of the lung, can be of primary help in the diagnosis of pulmonary interstitial infiltration and fibrosis when the patient's X-ray is normal.

Adult↗
PubMed1976

Thromboembolic disease.

In 52 patients with pulmonary embolism, the deep venous circulation of the lower extremities and the pulmonary arterial blood flow were studied with albumin macroaggregates labeled with technetium-99m. A gamma camera with a data processor was used for this study. At the beginning, the perfusion lung scintigrams were abnormal in all the patients, 42 of them also had abnormal phlebograms and in half of them the perfusion by lung scintigram became normal when the phlebograms were obtained. These findings establish the high incidence of deep thrombophebitis in the legs of the patients with pulmonary embolism and indicate that the leg is of the most important 'thrombi factory' and that the deep venous circulation of the extremities should be studied to determine the primary cause of the pulmonary embolism.

Humans↗