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Biomedical subjects

L Rossi

Publications and source records attributed to L Rossi.

At least 415 records · Page 23Linked to original sources

[Purification and properties of cytoplasmic and mitochondrial hexokinase from the rabbit brain].

The soluble Hexokinase from rabbit brain was purified 4,700-fold to near homogeneity by a combination of ion-exchange chromatography, dye-ligand chromatography and affinity chromatography. The purified enzyme showed a specific activity of 110 units/mg of protein and was obtained in 70% yield. The properties of the purified cytoplasmic hexokinase were compared with those of the solubilized mitochondrial enzyme. No significant differences were found in M.W., pI and electrophoretic mobility. However, the temperature dependence of activity and specificity for several hexose substrates were markedly different.

Animals↗

[Hexokinase in bone marrow cells in the rabbit].

The hexokinase isozymic pattern of circulating reticulocytes fractionated by density gradient ultracentrifugation was studied. All the cellular fractions obtained show similar ratio of hexokinase Ia/hexokinase Ib while a four fold decay in specific activity was evidenced. Bone-marrow cells of anemic rabbits also contain low amounts of HK Ib while this isozymic form is not present in basophilic erythroblasts.

Anemia↗

Favism: a hemolytic disease associated with increased superoxide dismutase and decreased glutathione peroxidase activities in red blood cells.

Red blood cells of favism patients with acute hemolytic crisis have markedly more superoxide dismutase (superoxide:superoxide oxidoreductase, EC 1.15.1.1) and less glutathione peroxidase (glutathione:hydrogenperoxide oxidoreductase, EC 1.11.1.9) than either normal controls, glucose-6-phosphate dehydrogenase-deficient subjects or favism patients outside hemolytic crisis. This altered value of the two enzyme activities is not due to increased reticulocyte content of blood. The electrophoretic triplet pattern of superoxide dismutase is also changed, with significant increase of the most positively charged band. Similar modifications of the two enzyme activities are observed after treatment of normal red blood cells with high concentrations of divicine and ascorbate, which are redox compounds that are contained in fava seeds. This treatment produces no hemolysis, but leads to hemolysis if the treated cells are resuspended in the homologous plasma. These results suggest a possible role of active oxygen species in the development of favism.

Ascorbic Acid↗

Pseudoperiodic paroxysmal discharge in a case of hemorrhagic shock.

We report a case of hemorrhagic shock associated with an EEG pattern resembling pseudoperiodic lateralized paroxysmal discharges, repeated focal motor seizures on the opposite side of the prevalent EEG abnormalities and consciousness disturbances in the absence of a demonstrable cerebral lesion occurring in a 45 year-old woman without a personal or familial history of epilepsy. This unusual electroclinical picture appeared inexplicably several days after the hemorrhagic shock when the laboratory data had already normalized. The only cause of this picture seemed to be brain hypoxia and the metabolic disorders consequent upon hemorrhagic shock.

Anticonvulsants↗

Auditory evoked potentials (early, middle, late components) and audiological tests in Friedreich's ataxia.

A functional assessment of the acoustic pathways in a group of 9 patients with Friedreich's ataxia was performed. In none of them was symptomatic auditory impairment noticeable. All patients were submitted to audiological tests and AEP recording. AEPs included early (BAEPs), middle (MLCs) and long (LLCs) latency components. The absence of one or more BAEP waves was observed in 5 out of 9 patients. N85 latency was significantly increased in all but one patient. MLCs, particularly P12, N15, P25 were often normal in amplitude and latency, scarcely showing a positive relationship with abnormalities of preceding and following waves. Pure tone audiometry revealed cochlear or neural impairment only in 2 patients. Speech audiometry showed deficits in all patients. These investigations, taken as a whole, showed a prevalent involvement of the brain-stem acoustic pathways, presumably at different levels, seldom associated with eighth nerve impairment. In some cases LLC (N85) abnormalities could not be interpreted as a consequence of impaired function in peripheral and brain-stem acoustic sites and might suggest a cortical dysfunction. Major BAEP abnormalities were observed in patients with longer disease duration, while N85 changes were unrelated to the duration and the severity of the illness. The former may prove to be a reliable means of monitoring the progression of the disease, the latter could be employed as a complementary procedure in its early diagnosis.

Adolescent↗

Transfer of additives from plastics materials into foodstuffs and into food simulants--a comparison.

The transfer of stearyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate from high- and low-density polyethylenes and polypropylene as well as that of n-butyl stearate from high-impact polystyrene into several foodstuffs and into different food simulants under normal storage conditions was determined radioanalytically. Additionally, the transfer of these additives into the food simulants under the standard conditions usually requested by the authorities was determined. From these figures 'correction factors' were calculated, relating the amounts of additives transferred from the plastics materials into the foodstuffs under normal conditions of storage to the transfer of these additives from the test specimens into food simulants (e.g. olive oil and HB 307) under the standard test condition of exposure at 40 degrees C for 10 days.

Butylated Hydroxytoluene↗

Anatomic and electrophysiologic substrate of the permanent form of junctional reciprocating tachycardia.

Data are reported on three patients with the permanent form of junctional reciprocating tachycardia, in whom conduction over a slow accessory pathway was observed after His bundle ablation. Tachycardia was almost incessant and showed a retrograde P wave (P') and RP' interval longer than P'R interval in all patients; during sinus rhythm, the PR interval was normal and there was no evidence of a delta wave. An accessory pathway with a long conduction time located in the posterior pyramidal space provided the retrograde limb of the reentry circuit. After His bundle ablation, the accessory pathway was capable of conducting in both anterograde and retrograde directions with decremental properties in all patients. Postmortem documentation of the accessory pathway was achieved in one patient. Serial sections revealed an accessory atrioventricular connection composed of ordinary myocardium joining the lower rim of the coronary sinus outlet to the uppermost ventricular muscle. This anomalous atrioventricular connection pursued a sinuous, tortuous path. As a result of changing cross-sectional area, such an accessory pathway might exhibit slow conduction, thus explaining its decremental characteristics.

Adolescent↗

Anatomopathology of the normal and abnormal AV conduction system.

The specialized conduction system of the heart is responsible for both congenital and acquired disorders of cardiac rhythm. Sinoatrial disorders may result from disruption of nodal cells and takeover by subsidiary pacemaker cells. AV block may occur congenitally or result from the ravages of ischemic heart disease. Clinically overt or concealed accessory pathway conduction via various types of bypass tracts are responsible for the genesis of many supraventricular arrhythmias. Anatomohistologic correlations provide the analytic basis for many disturbances of rhythm.

Adult↗

Congenital atrioventricular block in right atrial isomerism (asplenia). A case due to atrionodal discontinuity.

The association of complex congenital heart disease with asplenia syndrome and congenital AV block is described in a newborn. Cardiovascular lesions were right atrial isomerism, d-loop, discordant ventriculoarterial connection, pulmonary stenosis, total anomalous pulmonary venous drainage, absent right pulmonary artery, and bilateral superior vena cava. The ECG recording disclosed complete AV block with narrow QRS (suprahisian block). The histology of the conduction system revealed two AV nodes, one anterior and one posterior, none of which connected with the atrial myocardium; only the posterior node was continuous with a penetrating and bifurcating bundle. The histologic findings were consistent with the suprahisian AV block due to lack of connection between the atria and the regular posterior AV specialized junction.

Aorta, Thoracic↗

A method for simultaneous study of the karyotype, morphology, and immunologic phenotype of mitotic cells in hematologic malignancies.

A major problem in the cytogenetic analysis of hematologic neoplasms has been an inability to identify the cell from which the chromosomes were obtained. We describe a procedure that allows simultaneous analysis of karyotype and cell cytology in mitotic cells. The method differs from conventional cytogenetic analysis in that after mild hypotonic treatment, the cells are cytocentrifuged onto glass slides. In mitotic cells, this procedure often results in adequate spread of the chromosomes within the intact cell membrane. The cytoplasmic structure also remains intact, so that cytologic preparations are of good quality. Morphologic and immunologic identification of mitotic cells can be done using routine hematologic stains, such as Giemsa or Sudan black B, and various antisera using immunofluorescence techniques. The chromosomes can be simultaneously analyzed either without banding on slides stained with Giemsa or with Q-banding on slides stained with immunofluorescence techniques. Identification of numerical and structural karyotype aberrations thus is possible in morphologically identified cells.

Aged↗

Nursing care for survivors of sudden cardiac death.

The development of four new antiarrhythmic drugs offers promise for the treatment of patients who survive an episode of sudden cardiac death. Medical treatment, however, remains somewhat empirical, reflecting continued lack of total understanding of arrhythmogenesis and the pharmacokinetic properties of drugs required for suppression and control of arrhythmias. Further, although the value of such treatment cannot be underestimated, a healthy respect for the potential risk of arrhythmia aggravation by all of these drugs is warranted. The management of these patients presents a tremendous challenge for both physicians and nurses: physicians are responsible primarily for the definition of type, location, and severity of the arrhythmia; nurses focus primarily on the patient's response to illness and treatment in terms of its potential impact on their lifestyle. The clear focus for each discipline is necessary for development of a more purposeful and comprehensive treatment plan for the patient. As survival of sudden cardiac death increases, a number of patient responses, emotional and physical, have been noted clinically. The concept of nursing diagnosis can serve as a frame of reference from which nurses can begin to more scientifically evaluate their impact on patient care. Most importantly, it will contribute to an improvement in the care of patients whose lives have been so disrupted by the unpredictable nature of the arrhythmia and the investigational nature of treatment.

Adaptation, Psychological↗

The effects of hypolipidemic agents derived from procetofenic acid on the activity of superoxide dismutase and glutathione peroxidase and on malonyl dialdehyde production of rat liver.

Male and female rats were treated with hypolipidemic agents derived from procetofenic acid, namely fenofibrate ( procetofene ), cholestyrammonium alpha-(4-p-chlorobenzoyl-phenoxy)-isobutyrate (Alfa-1081) and alpha-(4-p-chlorobenzoyl-phenoxy)-isobutyryl-taurine (35/ipo). A marked decrease of liver superoxide dismutase and glutathione peroxidase was observed in the male rats treated with fenofibrate. In this sample a significant increase of malonyl dialdehyde was also detected when the liver homogenates were subjected to a test of lipid peroxidation induced by active oxygen species. Alfa-1081 and 35/ipo produced no substantial changes of superoxide dismutase and glutathione peroxidase and no significant increase of peroxidation products. These results, while providing an in vivo evidence for the role of superoxide dismutase and glutathione peroxidase as antioxidant enzymes, indicate that hypolipidemic agents can affect also enzymes not bound to membranes as they do with peroxisomal enzymes. The side effect presented here may be harmful, since it can lead to an augmented risk of lipid peroxidation in tissues. It is, however, clear that also within the same class of hypolipidemic drugs the effect is not always present. Peroxidative damage should therefore be considered as a key parameter in the characterization of hypolipidemic agents.

Animals↗

[Immunochemical determination of immunoglobulins and lysozyme in normal human saliva - principal assay technics].

We have studied a method to determine the concentrations of low level of immunoglobulins and lysozyme in saliva. The concentration of IgG, IgA and IgM in human whole saliva were measured by fluorimetric method and the concentration of lysozyme by turbidimetric method. The results of our study in 18 normal subjects (15 females and 3 males), have showed the geometric mean concentration (microgram/ml) IgG 5,1; IgA 177; IgM 2,6 and lysozyme 117.

Adolescent↗