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Biomedical subjects

P Colonna

Publications and source records attributed to P Colonna.

At least 73 records · Page 4Linked to original sources
PubMed1993

[Value and limits of fine needle aspiration biopsy in Hodgkin disease. Usefulness in developing countries].

The efficiency of a diagnostic procedure is evaluated by the percentage of subjects accurately identified, as either suffering from the disease looked for (true positive, TP) or not (true negative, TN). Sensitivity and specificity are the percentage of TP or TN, respectively, accurately identified. Cytological diagnosis of Hodgkin's disease (HD) was evaluated; smears were made from fine-needle aspiration. One hundred and nine smears were examined independently by two cytologists; adenopathies were benign in 43 cases (tuberculosis 25, non-specific reactive hyperplasia 16, sarcoidosis 2) and malignant in 66 cases (HD 36, Non-Hodgkin's lymphoma 22, malignant histiocytosis 2, metastasis 5, blast crisis of chronic myeloid leukemia 1). Benign and malignant diseases were diagnosed by lymph node biopsy; diagnosis of HD was made in 36 TP patients; the 73 others are TN. Sensitivity, specificity and efficiency are: 75, 90.4, 85.3, respectively for one observer; 77.7, 91.8, 87.1 respectively for the other: 63.8, 90.4, 81.6 respectively when diagnosis was the same for the two cytologists. Fine-needle aspiration permits the diagnosis of HD in eight out of 10 cases; it is useful when biopsy is difficult or too expensive, as is often the case in developing countries.

Adolescent↗
PubMed1993

Co-existence of the A and B types of Epstein-Barr virus DNA in lymph node biopsies from Algerian patients with Hodgkin's disease and non-Hodgkin's lymphoma.

The association of Epstein-Barr virus (EBV) with Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL) was examined in Algerian patients. The DNA extracted from fresh lymph node biopsies of 17 HD and five NHL was analysed by polymerase chain reaction (PCR). Fifteen out of 17 biopsies (88%) from HD contained EBV genome. Viral type analysis showed the coexistence of A and B types of EBV in 14 biopsies (93%), and the sole presence of A type virus in one biopsy. Among five NHL biopsies examined, four biopsies contained both A and B types of EBV, while one revealed A type-virus only. This co-infection of Algerian HD and NHL patients does not seem to be related with any histologic form of these diseases. The analysis of viral types in the saliva from 12 Algerian healthy individuals revealed six EBV positives with only one A type. Two types of lymphoma in Algeria therefore are closely associated with EBV, and are characterized by coinfection with A and B types of EBV.

Algeria↗
PubMed1993

Structural features of resistant starch at the end of the human small intestine.

Structural features of in vivo resistant starch were assessed using the ileal contents of four humans. Two of the latter were collected by ileostomy after ingestion of bean flakes or potato flakes and the other two were collected by an intubation technique after ingestion of retrograded high-amylose maize starch or complexed high-amylose maize starch. The degree of polymerizations (DP), solubility and crystallinity were assessed. For all samples, starch fractions which escaped digestion in the small intestine were composed of three populations of alpha-glucans with proportions differing according to the substrate. Small quantities of oligosaccharides made up the first population, illustrating a limitation of absorption in the small intestine. The second population, the main resistant fraction, was comprised of retrograded amylose of mean DPn of about 35 glucose units with a melting temperature at 150 degrees C and exhibiting a B-type pattern. Finally high molecular weight semi-crystalline alpha-glucans were attributed to fragments of starch. This study showed that some potentially digestible starch could reach the colon and crystalline fractions constituted only part of the starch that escaped digestion in the human small intestine.

Crystallization↗
PubMed1993

[Congenital isolated complete atrioventricular block: long-term experience with 38 patients].

BACKGROUND: The management of patients with isolated congenital complete heart block is controversial, and indications for cardiac pacing are not clearly defined. In the present study we report our long-term experience in the management of patients with this disease. METHODS: Thirty-eight consecutive patients aged 2 days to 28 years (mean age 10 years) were studied and followed up for 130 +/- 57 months (range 18 to 274). They underwent an extensive evaluation including history, physical examination, electrocardiography and echocardiography; thirty-seven patients had Holter monitoring and exercise test. Electrophysiologic study was performed in 24 patients. RESULTS: Twenty-two patients were asymptomatic, sixteen had symptoms as syncope or presyncope (7 patients), marked exercise intolerance (1 patient), presyncope and marked exercise intolerance (1 patient), heart failure (1 patient), mild dyspnea on exertion (6 patients). Electrocardiograms showed a narrow QRS in all patients. Holter monitoring showed a marked bradycardia (awake heart rate < or = 55 beats/min in infants, < or = 40 beats/min in children and adults) in 15 patients and junctional pauses of > 3 seconds in 9 of them. The exercise test showed a markedly reduced exercise tolerance in 2 patients and exercise-induced complex ventricular arrhythmias in 3 patients. Echocardiography showed a structurally normal heart and a normal left ventricular function in all patients. The electrophysiologic study always showed a suprahisian site of block. Twenty patients (53%) underwent cardiac pacing at a median age of 14 +/- 10 years and were followed up for 110 +/- 59 months (range 18 to 253) after pacing; prophylactic pacing was performed in 10 patients. Indications for cardiac pacing were: syncope or presyncope (7 patients), presyncope and marked exercise intolerance (1 patient), neonatal heart failure (1 patient), marked exercise intolerance (1 patient), neonatal marked bradycardia (2 patients), marked bradycardia with junctional pauses of > 3 seconds and/or complex ventricular arrhythmias (7 patients), complex ventricular arrhythmias (1 patient). No death occurred during the follow-up. In 9 of 20 patients who had cardiac pacing, indication for this procedure appeared during the follow-up (development of symptoms, marked bradycardia and/or complex ventricular arrhythmias). Complications of pacing were infrequent (9 complications in 7 patients) and mainly occurred in the first years of our experience. At present 12 patients have an atrioventricular sequential pacing and 8 have a rate-responsive ventricular one. All patients who had pacing showed an improvement of exercise tolerance; 11 of them underwent exercise test after pacing which showed a significant increase in exercise duration (from 11.1 +/- 1.9 to 15.3 +/- 1.1 min, p < 0.01). In the 3 patients with complex ventricular arrhythmias we observed their suppression after atrioventricular sequential pacing. At present 35 patients are asymptomatic and 3 have mild dyspnea on exertion. CONCLUSIONS: Our results confirm that patients with isolated congenital complete heart block often have symptoms and/or signs of electric instability without symptoms. Cardiac pacing relieves symptoms and improves working capacity. Although in this study we are not able to draw conclusions on the therapeutic value of prophylactic pacing, our favourable follow-up results suggest that this therapeutic approach may prevent complications.

Adolescent↗
PubMed1992

Assessment of QT dispersion in symptomatic patients with congenital long QT syndromes.

It has been suggested that QT dispersion recorded on the surface electrocardiogram may be a predictor of arrhythmic events in patients with congenital QT prolongation. To evaluate this, 9 patients (6 female, mean age 17.6 years) with congenital long QT syndromes, all of whom had syncope and documented torsades de pointes, were studied. Patients were studied off treatment and during therapy with beta-blocking agents. Three patients were also studied after left stellate ganglionectomy. An age-matched control group was also studied. Good quality 12-lead electrocardiograms were recorded from all patients. For each lead, QT and RR intervals were measured, and QTc value was calculated. QT and QTc dispersions were calculated for each patient. Patients had a significantly longer mean QT interval compared with that of the control group (450 +/- 100 vs 359 +/- 63 ms; p = 0.015) at similar mean RR intervals (736 +/- 231 vs 783 +/- 289 ms), with a longer mean QTc value (0.53 +/- 0.08 vs 0.41 +/- 0.02 s1/2; p = 0.004). Patients also had longer QT and QTc dispersions compared with those of the control group (110 +/- 45 vs 43 +/- 12 ms [p = 0.004], and 0.108 +/- 0.03 vs 0.05 +/- 0.02 s1/2 [p = 0.002], respectively). QT and QTc dispersions on and off beta-blocking agents were not significantly different. Comparing patients with frequent and those with infrequent symptoms, there was no difference in QT or QTc dispersion either off treatment or during therapy with beta-blocking agents.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

High-dose salvage chemotherapy without bone marrow transplantation for adult patients with refractory Hodgkin's disease.

PURPOSE: For patients with Hodgkin's disease (HD) who do not achieve complete response (CR), who experience a relapse within the first year of CR, and for those who have two or more relapses, the outcome is poor. Salvage chemotherapy regimens at conventional doses produce a CR rate that ranges from 10% to 50% and a 5-year disease-free survival (DFS) between 10% and 25%. On the other hand, high-dose chemotherapy regimens given in combination with bone marrow transplantation (BMT) produce a CR rate that ranges from 40% to 80% and a 3-year DFS of approximately 40%. We report the 5-year results of a prospective study in patients with refractory HD who were treated with three courses of intensive chemotherapy without BMT. PATIENTS AND METHODS: Thirty-nine adult patients with refractory HD were treated with three courses of intensive chemotherapy. Each cycle of chemotherapy comprised vindesine 1 mg/m2/d in continuous intravenous (IV) infusion from day 1 to day 5; Adriamycin (doxorubicin; Roger Bellon Laboratories, Neuilly, France) 40 mg/m2/d in continuous IV infusion from day 1 to day 3; carmustine 140 mg/m2/d at day 3; etoposide 200 mg/m2/d from day 3 to day 5; and methylprednisolone 120 mg/m2/d from day 1 to day 5. After the third cycle of chemotherapy, irradiation (20 Gy) was performed whenever possible and depended on previous irradiation. RESULTS: At the end of the treatment, 31 patients (79%) were in CR. Among these patients, 10 relapsed after a median time of 3 months. The overall 5-year survival rate was 46%. The freedom from progression (FFP) and the freedom from treatment failure (FFTF) rates were 48% and 43%, respectively. The main toxicities were hematologic (neutropenia and thrombocytopenia) and digestive. Four patients died due to treatment-related complications (two from septic shocks, one from respiratory insufficiency, and one from posttransfusional AIDS). CONCLUSION: The results of this study seem to be comparable to those results obtained with high-dose chemotherapies with autologous BMT.

Adolescent↗
PubMed1992

Quantification of red blood cell fragmentation: usefulness of heating cells and of automatic counting devices.

Spontaneous red blood cell (RBC) fragmentation occurs in some membrane erythropathies like hereditary elliptocytosis (HE); this phenomenon is produced in normal RBC by heating at 49 degrees C, but not at temperatures below this limit; fragmentation is usually quantified by counting the number of fragments/1000 RBC under light microscopic examination. The present work demonstrates: i) that enumeration of fragments is performed more precisely with an automatic blood cells counter on the 'platelet' channel; and ii) that heating at 48 degrees C enhances the fragmentation of RBC when they have a severe disruption of skeletal lattice, like in HE.

Electronics, Medical↗
PubMed1992

Limiting factors of starch hydrolysis.

Foods appear as complex structures, in which starch may be present in different forms. These, including the molecular characteristics and the crystalline organization, depend on processing conditions and compositions of ingredients. The main changes in starch macro- and microstructures are the increase of surface area to volume ratio in the solid phase, the modification of the crystallinity as affected by gelatinization and gelation, and the depolymerization of amylose and amylopectin. Starch modification may be estimated by different methodologies, which should be selected according to the level of structure considered. When amylose and amylopectin are in solution, rapid and total hydrolysis leads to the formation of a mixture of linear oligosaccharides and branched alpha-limit dextrins. However, starch usually occurs in foods as solid structures. Structural factors of starchy materials influence their enzymic hydrolysis. A better understanding of the enzymatic process enables the identification of the structural factors limiting hydrolysis: diffusion of enzyme molecules, porosity of solid substrates, adsorption of enzymes onto solid substrates, and the catalytic event. A mechanistic modelling should be possible in the future.

Animals↗
PubMed1991

Occurrence and characteristics of hereditary spherocytosis in Algeria.

In a survey of more than 12,000 persons referred to a hematological outpatient clinic in Algiers, we estimated that the incidence of hereditary spherocytosis (HS) is 1/1000. Another 9 cases were found in nine of the corresponding families. Anemia was present in a total of 44 subjects (81%). The transmission was dominant in five of eight informative families (63%). No firm conclusion could be reached concerning the amount of spectrin and ankyrin in nine families; however two-dimensional peptide maps ruled out any alphaII domain abnormality in these families. We estimate that HS has roughly the same incidence and features among Algerians as in Europeans or people of European descent.

Adolescent↗
PubMed1991

[Competitive sports activity in subjects undergoing the surgical correction of an ostium-secundum type of interatrial defect: the experience of 9 cases].

Patients who have undergone surgical repair of congenital heart diseases are usually not allowed to participate in competitive sports. In the present study we report our long-term experience with 9 male athletes aged 17 to 23 years who participate in competitive sports after undergoing surgical repair of ostium secundum atrial septal defect at a median age of 9 years; six of them play football and three of them volleyball. Competitive sport activities began 1 to 5 years after surgical repair. The mean duration of follow-up is 88 +/- 26 months. Sport fitness was granted on the basis of the following criteria: 1) a normal physical examination; 2) a normal working capacity on exercise test; 3) no arrhythmias on exercise test and Holter monitoring, recorded also during sport activities; 4) a normal M-mode and two-dimensional echocardiography, including the normalization of right ventricular size; the persistence of an abnormal ventricular septal motion did not exclude sport fitness. Recently we also performed Doppler and color Doppler echocardiography and gated equilibrium radionuclide angiography at rest and during exercise. We studied left ventricular diastolic filling through the pulsed wave Doppler evaluation of transmitral flow and measured cardiac output by continuous wave Doppler echocardiography during exercise test in the supine position. We also performed exercise test and M-mode, two-dimensional, Doppler and color Doppler echocardiography in a control group made up of 15 athletes (10 football players and 5 volleyball players). The exercise duration at graded treadmill exercise test (according to the Carù protocol), the maximal heart rate and the maximal systolic blood pressure were, respectively, 12.9 +/- 0.8 min, 192 +/- 10 beats/min and 198 +/- 12 mmHg. Left ventricular end-diastolic dimension, mass and ejection fraction (single-plane area-length method) were 50.3 +/- 2.8 mm, 210 +/- 38 g and 65 +/- 6%. M-mode right ventricular diastolic dimension was 23.4 +/- 1.6 mm; the right ventricular maximal diastolic diameter and area obtained on two-dimensional echocardiography from the apical four chamber view were 44.1 +/- 3.6 mm and 25 +/- 3.8 cm2 respectively. The evaluation of transmitral flow showed the following data: E velocity 77 +/- 12 cm/sec, A velocity 45 +/- 6 cm/sec, E/A ratio 1.7 +/- 0.3, the isovolumic-relaxation period 72 +/- 8 m/sec and the deceleration half-time of the early rapid filling 71 +/- 10 m/sec. A trivial tricuspid regurgitation was detected in 6 subjects; the peak velocity of the regurgitant jet was less than 2.1 m/sec.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1990

Evidence that expression of Sp alpha I/65 hereditary elliptocytosis is compounded by a genetic factor that is linked to the homologous alpha-spectrin allele.

Many cases of hereditary elliptocytosis (HE) result from mutated spectrin alpha-chains. It has repeatedly been observed that the amount of a mutant alpha-chain is different in various affected individuals, resulting in clinical pictures of variable severity. The different levels are thought to result from different percentages of the alpha-spectrin allele in trans. Such percentages, in turn, could be under genetic control. We tested this hypothesis in a large Algerian family with Sp alpha I/65 HE. In an informative sibship, we found three persons with a distinctly high level of expression of the Sp alpha I/65 variant, suggesting the existence, in trans, of a low percentage alpha-allele. The alpha-spectrin gene haplotype associated with the latter was constantly - + -, based on the XbaI, PvuII, and MspI polymorphic sites. In contrast, a basal level of expression of the Sp alpha I/65 variant in the same sibship indicated, in trans, the existence of a normal percentage alpha-allele. The haplotype corresponding to this other alpha-allele was + - +. Study of another generation of the family showed, however, that the - + - haplotype could also be linked to a normal percentage alpha-allele. These results are consistent with the view that the expression level of alpha I/65 spectrin (and of other types of alpha-variants) is compounded by a genetic factor that is linked to the normal alpha-allele in trans. The low percentage allele itself remains silent in the simple heterozygous state.

Elliptocytosis, Hereditary↗
PubMed1990

Pasta cooking time: influence on starch digestion and plasma glucose and insulin responses in healthy subjects.

The influence of pasta cooking time on starch digestion and plasma glucose and insulin responses was studied in 12 healthy subjects. During 3 consecutive days, one of three pasta test meals (50 g starch) cooked for 11, 16.5, and 22 min was served to each volunteer in a random order. Hydrogen and methane breath excretion was measured after pasta ingestion; plasma responses were compared with those of an equivalent oral glucose-tolerance test. No significant differences were found between cooking times and plasma indices, orocecal transit time, or incremental hydrogen excretion (delta peak hydrogen). With one exception, pasta meals that were completely absorbed were ingested by methane producers. Postprandial delta peak hydrogen was significantly lower in methane than in nonmethane producers (p less than 0.02). These results point to a lack of influence of cooking time on nutritional characteristics of pasta and suggest that starch malabsorption determined by breath-hydrogen-test criteria may be underestimated in methane producers.

Adult↗