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Biomedical subjects

G Longo

Publications and source records attributed to G Longo.

At least 127 records · Page 7Linked to original sources
PubMed1990

Hepatitis B virus (HBV) markers and HBV-DNA in serum and liver tissue of patients with acute exacerbation of chronic type B hepatitis.

We analysed the serum samples and the liver biopsies of six consecutive chronic HBsAg/anti-HBe carriers admitted to hospital because of an episode of acute hepatitis. The six patients became positive for IgM anti-HBc and negative for HBeAg, hepatitis Delta virus (HDV) markers, IgM anti-hepatitis A virus (HAV), anti-cytomegalovirus (CMV) and anti-Epstein-Barr virus (EBV). Two patients showed positivity for hepatitis B virus (HBV)-DNA in serum obtained on admission, with no positivity in the subsequent weeks; the results of the other four patients were always negative for seric HBV-DNA. The Southern-blot analysis of the DNA extracted from the liver tissue of four subjects showed the presence of HBV-DNA in the form of replicative intermediates; focal positivity of HBcAg was detected in the liver of only one. The liver biopsies of the last two patients were negative for HBV-DNA and for HBcAg. The analysis of HBV-DNA in the liver extracts and the demonstration of an increase of the IgM anti-HBc titre at the time of the abrupt elevation of the aminotransferase levels seem to be the most useful tools in revealing HBV activation as a cause of acute hepatitis in chronic HBsAg carriers, overall when the phase of viremia is transient.

Antigens, Viral↗
PubMed1990

Determination of dependence of spin-lattice relaxation rate in serum upon concentration of added iron by magnetic resonance imaging.

Dependence of spin-lattice relaxation rate (1/T1) in serum upon concentration of added iron was studied in the concentration range 0.0179-0.179 mmol l-1 for each of ferrous and ferric iron. In conjunction with the serum study, 1/T1 in solutions of transferrin and a mixture of albumin and gamma globulin was also studied as a function of added iron concentration. At low concentrations 1/T1 in serum increases linearly with increasing amounts of iron for each ion, and then reaches saturation for ferrous iron, whereas it shows an inflection for ferric iron. To explain the partition of added iron between various serum components, the effect of iron on 1/T1 in serum was compared with those of transferrin and the mixture. This effect can be defined as relaxivity or the incremental increase in relaxation rate per millimolar of added iron. At low concentrations the relaxivities of iron in serum, about 0.91 mmol-1 l s-1 for ferric and 0.95 mmol-1 l s-1 for ferrous ion, approximate well to the relaxivity of iron in transferrin solutions, which was measured to be about 0.92 mmol-1 l s-1. Furthermore, at high concentrations the relaxivity of ferric iron in serum, 0.44 mmol-1 l s-1, becomes similar to that of the mixture which is about 0.39 mmol-1 l s-1. These findings imply that iron added to serum first satisfies the binding requirements of transferrin, and the binding of iron to the other serum proteins occurs at high concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood↗
PubMed1990

Subclinical changes of auditory function in the aged.

Elderly normal hearing subjects were studied using tests for cochlear functions (remote masking, brief tone audiometry, critical ratio, evoked otoacoustic emission), for neural auditory function (tone decay) and for central auditory functions (ipsilateral vs. contralateral acoustic reflex, tonal masking level difference). The findings demonstrated that ageing can cause subclinical abnormalities, almost consistently localized to the inner ear vibrating structures and only occasionally to the sensory and/or neural elements.

Acoustic Impedance Tests↗
PubMed1990

[Loratadine and dexchlorpheniramine in the treatment of perennial allergic rhinitis in pediatric patients].

The use of loratadine was compared to dexchlorpheniramine in the treatment of children affected by perennial allergic rhinitis in order to assess its clinical efficacy and tolerability. Children were randomly assigned to two groups: 15 were treated with loratadine and 16 with dexchlorpheniramine. Loratadine was administered in a single daily dose of 5 mg (2.5 mg for children under 20 kg) and dexchlorpheniramine at a dose of 1 mg every 8 hours (0.5 mg for the youngest children). Clinical symptoms were recorded before and during the study using a score of 0.3 (from absent to severe). Symptoms were markedly reduced by both drugs. Eye burning was reduced more by loratadine (p less than 0.05) than the control drug. Rhinoscopic investigations revealed that both groups reacted favourably to the drugs used. Overall clinical assessment showed similar and revealed the good efficacy of both drugs. Tolerability was satisfactory and there were no signs of drowsiness. Hematological and hematochemical parameters showed no clinically significant changes and body weight remained constant. On the basis of these results, loratadine is preferable to dexchlorpheniramine thanks to its once-a-day dosing.

Age Factors↗
PubMed1990

Lectin binding to the egg envelopes in Eyprepocnemis plorans (Charp.) (Orthoptera, Acrididae).

The distribution of glycoconjugates in the egg envelopes of Eyprepocnemis plorans was investigated using various FITC-conjugated lectins. In the epichorion, the lectins ConA, SBA and WGA each have particular binding patterns, while TPA binding is confined to its deepest regions only. The glycoconjugates of the micropylar wall present different characteristics from those of the surrounding chorion. The vitelline coat shows a marked binding for WGA and TPA only; below the inner micropylar openings, this binding pattern is uniform over the whole extent of the coat and therefore it is not possible to identify specific binding sites for these two lectins. Contrary to what has been observed in some other insect species, the vitelline coat does not seem to be involved in the structural organization of the mycropyles.

Animals↗
PubMed1990

[Evoked acoustic oto-emissions: effects of atropine].

The Evoked Otoacoustic Emissions (EOE) are a sinusoidal wave complex coming from the contractile properties of the cochlea and particularly of the outer hair cells. This activity is influenced by the centrifugal pathways whose transmitter is acetylcholine. In order to study the effects of the functional block of the cochlea, ten young normal subjects were examined recording the EOE before and ten mins after the i.v. infusion of 1 mg of atropine. The statistical analysis of the results has shown a significant decrease only in EOE appearance threshold in absence of modifications of the saturation level. These data have led us to believe that atropine blocking of the centrifugal pathways causes a disfunction of the outer hair cells that accept less energy to be transduced into a neural stimulus and on the other hand more energy as EOEs.

Adolescent↗
PubMed1990

[Effects of body posture on cochlear performance].

Experimental research has demonstrated that changes in body position influence auditory function and, specifically, supine position produces a sensorineural hearing loss at low frequencies. The hypotheses to interpret these phenomena are principally referred to an increase of hydrostatic pressure of labyrinthine fluids. In order to evaluate the effects of head position on the cochlear performance a modern test battery has been performed to study cochlear function in 11 normal subjects ranged in age from 22 to 34 years. The tests (Remote Masking:RM; Brief Tone Audiometry:BTA; Critical Ratio:RC) have been evaluated in two positions: sitting upright and supine with the head at a 20 backward angle. The results of our research have shown that in all the cases, the supine position produces a significant shift of the auditory threshold at 250 and 500 Hz, and a decrease of RM values in about all of the cases. We have estimated non statistically significant differences for the RC and BTA values, in more than half of the ears tested. On the basis of the significance given to RM, BTA, RC: we can deduce that the modifications of the auditory performance related to an increase in perilymphatic hydrostatic pressure, induced by the head position are produced by an increase in rigidity of the mechanical vibratory structures of the cochlea rather than the expression of sensorineural damage.

Adult↗
PubMed1989

Protein content and factor VIII complex in untreated, treated and monoclonal factor VIII concentrates.

Replacement therapy with clotting factor concentrates may expose the recipients not only to virus contamination but also to continuous stimulation of the immune system by repeated infusions of allogenic proteins. Concentrate purity is now a very important prerequisite to be taken into account in choosing what product can better meet the patient's needs. We compared protein content (albumin, fibrinogen, fibronectin, immunoglobulins) and factor VIII:C/vWF:Ag complex in untreated, treated and monoclonal factor VIII concentrates. Protein content is dramatically decreased in new treated ultrapure concentrates. Improved traditional fractionation methods allowed to obtain very high Factor VIII specific activity. New fractionation methods with immunoaffinity chromatography by means of monoclonal antibodies can give highly pure concentrates even if deliberately added albumin decreases factor VIII specific activity in final formulation. Otherwise monoclonal concentrates show a very high specific activity in terms of fibrinogen and immunoglobulin content, which, unlike albumin, are affecting the immune system in hemophiliacs.

Antibodies, Monoclonal↗
PubMed1989

Evaluation of factor VIII pharmacokinetics in hemophilia-A subjects undergoing surgery and description of a nomogram for dosing calculations.

The pharmacokinetics of factor VIII were studied in a series of 20 hemophilia-A patients undergoing surgery. Regardless of the type of operation, elimination of factor VIII was shown to be increased only in ten cases (50%) during the post-operative period. In this subgroup of patients, factor VIII half-life, measured immediately after surgery, was considerably shorter (mean = 9.6 hr, n = 10) than that determined in the same individual during the late operative period (mean = 17.8 hr, n = 10). These findings indicate that identification of patients with increased postoperative consumption of factor VIII can be of value in reducing the risk of hemorrhage in these subjects and in exposing other subjects with no postoperative increase in factor VIII clearance to less of the deficient factor. Data from 20 subjects were analyzed to construct a nomogram allowing individualized prediction of factor VIII dosing requirements. The nomogram, which is based on the "single point after a single dose" method, uses a value of factor VIII concentration measured at 10 hr after preoperative loading dose to predict the regimen producing the desired average steady-state concentration of factor VIII (30, 60, or 90 units/dl).

Adolescent↗
PubMed1989

Follow-up of subjects who developed chloracne following TCDD exposure at Seveso.

Three follow-up surveys from 1976 to 1985 were carried out on 193 subjects who developed chloracne following the Seveso accident (1976). A comparison group, age and sex matched, was selected randomly from the list of residents of the town of Varedo (in the same health district but out of the dioxin-contaminated zone). At each follow-up a questionnaire was administered and biochemical tests, skin examination, and electrophysiologic measurements were performed. Biochemical indicators of hepatic function and nerve conduction studies did not show significant differences either between groups or for temporal trends. Chloracne was shown to be clinically reversible: all the chloracne cases (except for one subject) clinically recovered by 1983. The discrepancy between our results and those from other previous experiences can be related to a different type of exposure, the young age of the target population, and the interval since exposure.

Accidents↗
PubMed1989

Two rare developmental defects of the lower limbs with confirmation of the Lewin and Opitz hypothesis on the fibular and tibial developmental fields.

We report on two unrelated patients with malformations of the lower limbs. One had a unilateral apparent doubling of the volume of the femur with distal bifurcation, shortness of the tibiae, absence of fibulae, and lateral ray deficiencies of both feet. The other had a partial duplication of the distal left femur, hypoplasia and proximal dislocation of the ipsilateral tibia, syndactyly of the right 1st and 2nd toes, and preaxial polydactyly of the left foot. This report supports the hypothesis of Lewin and Opitz on the presence of two distinct fields of development: the fibular and the tibial.

Abnormalities, Multiple↗
PubMed1989

Does ergometric stress test induce a procoagulative condition in patients with previous myocardial infarction?

A regularly scheduled physical training program seems to have antithrombotic effects. Moreover, the hemostatic changes occurring in patients with coronary artery disease during acute exercise have not been clearly elucidated. Since stress testing is routinely performed in clinical cardiology, it would be helpful to assess whether patients with coronary artery disease are exposed to acute coronary thrombosis during or soon after sustained physical exercise. This study was designed to evaluate the effect of acute physical exercise (stress test by bicycle ergometer) on blood coagulation in a group of patients with previous myocardial infarction, and to determine whether the antithrombotic therapy commonly administered favorably influences hemostatic equilibrium. Our results suggest that exercise testing is not harmful to patients with previous myocardial infarction in regard to hemostasis and fibrinolysis and that antithrombotic therapy reduces postexercise increase in platelets.

Aged↗
PubMed1989

Studies on thiamine metabolism in thiamine-responsive megaloblastic anaemia.

We have investigated thiamine metabolism and transport in the erythrocytes of two patients from unrelated families with thiamine responsive megaloblastic anaemia associated with diabetes mellitus and sensorineural deafness. Both patients had low concentrations of thiamine compounds in plasma and red blood cells. When erythrocytes were incubated with thiazole-[2-14C]-thiamine or [35S]-thiamine in vitro, the concentration of label within the cells was markedly reduced compared with controls. In addition, thiamine pyrophosphokinase activity was deficient in haemolysates prepared from the patients. Some relatives of the patients showed abnormal parameters of thiamine status and transport. In both patients treatment with a lipophilic compound corrected the haematological abnormalities and diabetes and in one patient has so far prevented the progression of deafness. We propose that the disorder is caused by an inherited defect of thiamine transport, possibly related to deficient pyrophosphokinase activity, leading to intracellular depletion of active thiamine metabolite derivatives.

Anemia, Macrocytic↗
PubMed1989

Spin-lattice relaxation rates in Fe(III)-doped human serum measured by magnetic resonance imaging.

The proton spin-lattice relaxation time T1 in iron-doped serum was measured with a magnetic resonance imager operating at 0.5 T. The T1 in aqueous solutions of iron and iron-doped solutions of albumin and gamma globulin was also measured in order to analyse the paramagnetic contribution in iron-doped serum. The enhancement in serum is not linearly dependent on concentration of iron added. It is known that Fe(III) added to serum is mainly complexed with transferrin, albumin, gamma globulin and water. With serum pH (7.9) Fe(III) in the protein solution results in enhancement. Fe(III) in water does not cause any enhancement. As a result, the 1/T1 enhancement in serum should be caused solely by iron-binding serum proteins.

Blood↗
PubMed1989

Hepatitis B-DNA replication and histological patterns in liver biopsy specimens of chronic HBsAg positive patients with and without hepatitis delta virus superinfection.

The role of active hepatitis B virus (HBV) infection in chronic HBsAg positive hepatitis with and without hepatitis delta virus (HDV) superinfection was analysed in percutaneous liver biopsy specimens from 50 patients. Each specimen was divided into two--one part for histological evaluation and for the detection of HBcAg and delta antigen; the other part was tested for HBV-DNA using Southern blotting. Ten cases were of chronic lobular hepatitis, 10 of chronic persistent hepatitis, and 30 of chronic active hepatitis. Ten cases were delta antigen positive and showed high grade lobular activity but no evidence of HBV-DNA episomal forms or HBcAg reactivity. Twenty one cases showed HBV-DNA replicative intermediate forms; 19 had high grade lobular activity, which occurred in five cases without evidence of free viral DNA. Of the 21 biopsy specimens with HBV-DNA episomal forms, 14 were positive for HBcAg; only one of the 19 cases without detectable viral DNA was positive for such antigen. These data indicate that the presence of HBV or HDV active infection correlates with the histological finding of prominent lobular necrosis. Moreover, intrahepatic HBV-DNA seems to be a more sensitive marker than the presence of viral antigens for indicating HBV replication.

Carrier State↗
PubMed1989

Paroxysmal electroencephalographic abnormalities genetically transmitted: one family description.

A 10-year-old girl came to our observation since a general rule-out electroencephalogram (EEG) had showed, in absence of any clinical manifestation, generalized and symmetrical 3 c/s spike-and-wave bursts, whose duration was longer than 3 s. The subject, only daughter born from her mother's first marriage, had no family history of neurological diseases; her physical and neuropsychological examinations were normal. A polysomnographic recording showed, during sleep, the same abnormalities observed during wakefulness. Also on this occasion, there were no related clinical manifestations. Subsequent recordings were performed on her 33-year-old mother and on two siblings, 3 and 2 years old, respectively, born from their mother's second marriage, all normal by physical and neuropsychological examinations, with no referral about clinical seizures. Among them, the 3-year-old sister showed asymptomatic left rolandic spikes, while the 2-year-old boy, whose EEG was firstly normal, displayed, 1 year later, a burst of generalized 3 c/s spike-and-wave paroxysmal activity on a 4-7 c/s background activity. The possible unitary genetic transmission of paroxysmal EEG abnormalities is discussed.

Adult↗