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Biomedical subjects

R Manfredini

Publications and source records attributed to R Manfredini.

At least 127 records · Page 7Linked to original sources
PubMed1992

[Ventricular stimulation triggered by esophageal atriogram: a new technique of temporary physiologic stimulation in the course of acute myocardial infarct complicated by atrioventricular block and low cardiac output].

Advanced atrio-ventricular (AV) block during acute myocardial infarction (AMI) is considered a complicating dysrhythmia as the well as mechanism responsible for occurrence of life-threatening hemodynamic changes. Often, simple VVI pacing can result insufficient in improving the decreased cardiac output. VDD pacing, which preserves atrial contribution, should represent the most effective electrical approach; therefore, it requires intracavitary placement of 2 catheters. In 10 pts (6M, 4F, mean age of 63.8 +/- 6.6 years) with advanced AV block due to AMI (4 inferior, 6 anterior) and without sinus node dysfunction, we performed stable VDD stimulation (mean 16.6 +/- 20.6 hours) using only one catheter positioned in the right ventricle while the atrial impulse, filtered (50-70 Hz) and amplified through a special device, was derived from the esophagus. Such technique is rapid and reliable, avoiding problems associated with atrial sensing and catheterization.

Aged↗
PubMed1992

[Chronobiological approach to renal colic].

The concentration of lithogenic and antilithogenic substances in urine shows circadian fluctuations. With this investigation we intended to verify the presence of a chronobiologic rhythm of colic pain in urinary tract calculosis. Four hundred and forty seven consecutive patients with a clinical symptomatology related to urinary tract colic pain were studied. They were subdivided according to sex and age (297 M, 150 F; > or = 65 ys 29, < 65 ys 428). Urinary and blood chemical analysis and instrumental examinations permitted to confirm the clinical diagnosis. To evaluate the circadian and circannual variability, acute events were grouped into one calendar year by the month and into a ideal day by the hour of occurrence respectively. Chronobiologic analysis was performed utilising Halberg single cosinor test. The results pointed out that the symptomatology related to urinary tract colic pain presents a circadian rhythmicity either in patients as a whole or in single subgroups (males, females, younger or older than 65 ys). Besides no seasonal variability was demonstrated, perhaps because of the mild climate present in the geographic area in which the study was carried on.

Adolescent↗
PubMed1991

Thalassaemia trait and myocardial infarction: low infarction incidence in male subjects confirmed.

A total of 4401 subjects admitted to the Medical Division of St Camillo Hospital in Comacchio (Ferrara, Italy) over a period of 7 years were prospectively evaluated in order to determine whether the heterozygous beta-thalassaemic (HBT) could be considered as a protective factor against the occurrence of acute myocardial infarction (AMI). Of the total patient sample, 3954 subjects were non beta-thalasaemics (NBTs), and 447 subjects were heterozygous beta-thalassaemics (HBTs). AMI was diagnosed in 384 patients, of whom 17 individuals were HBTs and 367 subjects were NBTs. The prevalence of HBTs in this group was significantly lower than expected (4.43%, P less than 0.0001). Furthermore, an analysis by sex showed that this lower prevalence could be attributed to male patients. Moreover, only in male subjects was a significant negative correlation observed between AMI and HBT. The mean age at which AMI occurred in male HBTs was significantly higher than in male NBTs (72 +/- 2.69 vs. 63 +/- 0.7 years, P less than 0.05), while no differences were found in the mean age at which AMI occurred between HBT and NBT female subjects. This study demonstrates that the thalassaemic trait may afford some protection against the occurrence of AMI in men.

Aged↗
PubMed1991

Circadian rhythm of blood pressure and calcium entry blockade: a chronobiologic study with nitrendipine in essential hypertension.

In order to evaluate the chronobiologic effect of nitrendipine, 27 patients with mild-to-moderate arterial essential hypertension were studied. After randomized administration of 20 mg of nitrendipine and placebo, systolic and diastolic blood pressure (SBP and DBP, respectively) and heart rate (HR) were measured for 24 h using an automatic noninvasive device. The data of the time series were statistically analyzed by single and mean cosinor methods (obtaining mesor, amplitude, and acrophase) and by ANOVA and Student's paired t test. Nitrendipine significantly reduced the SBP and DBP mesors without affecting the HR mesor, and reduced the SBP and DBP amplitudes while increasing the HR amplitude. After placebo, group circadian rhythms were observed for SBP, DBP, and HR and maintained after nitrendipine. In conclusion, a single-dose administration of nitrendipine is effective in lowering blood pressure. The increased HR amplitude is probably due to a tachycardic reaction. The preservation of the SBP, DBP, and HR group circadian rhythms agrees with the lack of interference of the drug with the neurohormonal mechanisms.

Adult↗
PubMed1991

[Survival in post-infarction heart rupture. A case report. Role of echocardiography in immediate diagnostic approach].

A case of acute myocardial infarction of the inferior-posterior and lateral wall of the left ventricle, complicated at the onset with cardiogenic shock and myocardial rupture of the free wall, is presented. The precise and immediate echocardiographic diagnosis made it possible, by means of appropriate pharmacologic support, to reach a satisfactory haemodynamic balance in order to send the patient to decisive surgical operation.

Echocardiography↗
PubMed1991

[Therapy and prevention of atrial fibrillation].

In the last decade, broader insights into the mechanisms and clinico-prognostic significance of atrial fibrillation have prompted a dramatic shift in the clinician's decision making process in terms of treatment and prevention of this common rhythm disturbance. In fact, evidence of short- or long-term untoward effects on cardiac function and the risk of cerebrovascular accidents, together with a much wider therapeutic armamentarium, form the rationale for the present far more aggressive attitude, aiming at restoring sinus rhythm in all patients in whom an even weak chance exists. The newer class IC (flecainide, propafenone) and class III (amiodarone, sotalol) antiarrhythmic agents are widely and successfully utilized to restore and to maintain sinus rhythm, with significant advantages in comparison with classic quinidine derivatives in terms of efficacy and patient compliance, as demonstrated in clinical controlled trials. Moreover, calcium channels blocking agents as verapamil and diltiazem have been demonstrated more effective than digitalis in the limitation of ventricular rate in patients with chronic atrial fibrillation. Although the advantages of long-term anticoagulation and/or antiaggregation in patients with atrial fibrillation are still being widely investigated at the present time, data obtained in the last years favoured a wider use of this treatment. Many non-pharmacologic interventions have been shown as dramatically effective in particular aspects of atrial fibrillation. Permanent atrial or atrioventricular pacing, alone or in association with antiarrhythmic drugs, has come out as first choice option in patients with bradycardia-tachycardia syndrome. Transcatheter ablation and antiarrhythmic surgical techniques are more and more widely utilized with increasing success in cases refractory to conventional approaches.

Anti-Arrhythmia Agents↗
PubMed1990

Noncoordinated expression of S6, S11, and S14 ribosomal protein genes in leukemic blast cells.

The steady state levels of mRNAs codying for the ribosomal proteins S6, S11, and S14 have been evaluated in quiescent and proliferating human fibroblasts and in resting and proliferating human peripheral blood mononuclear cells. It was found that the amounts of ribosomal protein mRNA are very similar and are not increased by serum or mitogen stimulation. The constitutive expression of these genes appears to be coordinately regulated and it is not modified after protein synthesis inhibition by cycloheximide. The ribosomal protein mRNA was also assayed in 15 different populations of human leukemic blast cells. In these populations the abundance of each ribosomal protein mRNA is remarkably different from the other. The results of our present experiments indicate that the expression of the three ribosomal protein genes undergoes independent noncoordinated changes in the large majority of the leukemic populations studied.

Blast Crisis↗
PubMed1990

Ratios between the abundance of messenger RNA and the corresponding protein of two growth-related genes, c-myc and vimentin, in leukemia blast cells.

The abundance of the mRNAs of two growth-related genes, vimentin and c-myc, and that of the corresponding proteins have been studied in unstimulated and phytohemagglutinin-stimulated lymphocytes as well as in 18 populations of leukemic blast cells. The quantitative assay was carried out by densitometric scanning of Northern and Western blots. In normal lymphocytes the mRNA and the protein of both genes were almost undetectable. The phytohemagglutinin stimulation led to a sharp increase of the mRNA and the proteins of vimentin and c-myc. The increase was followed by a progressive fall of the gene products. The rate of decrease of the two mRNAs was similar to that of the corresponding proteins. In some leukemic populations very similar amounts of the vimentin protein were accompanied by amounts of the mRNA differing at least 25 times. Not unlikely, very similar amounts of p62c-myc corresponded to mRNA abundances differing at least 16 times. The coordinated biogenesis of both messenger RNAs and proteins, which occurs in mitogen-stimulated lymphocytes, is substituted, in approximately 30% of the leukemic blast cell populations, by molecular events leading to the accumulation of an excess of mRNA.

Blast Crisis↗
PubMed1990

Overexpression of the MPO gene occurring in a case of APL without unusual genotypic characteristics.

Northern blot analysis of four typical cases of acute promyelocytic leukemia showed that one of the cell population examined was characterized by a very high level of expression of the myeloperoxidase (MPO) gene. Western blot analysis confirms that the protein content of the cells corresponded to the levels of the MPO mRNA. Southern blot studies of the DNA of this cell population ruled out the presence of any genome amplification or rearrangement. Chromosome hybridization studies in situ confirmed that the MPO gene was translocated on the long arm of chromosome 15. The observation that a typical genomic pattern may or may not be associated with the MPO overexpression leads us to believe that so far it is impossible to reach any conclusion about the significance of the translocation in the genesis of MPO overexpression.

Blotting, Southern↗
PubMed1990

Differential effects of c-myb and c-fes antisense oligodeoxynucleotides on granulocytic differentiation of human myeloid leukemia HL60 cells.

To gain some insight into the role of c-myb and c-fes in myeloid differentiation, the authors have analyzed the ability of HL60 cells to differentiate in response to several different inducers after inhibition of c-myb and c-fes function. This function has been inhibited almost completely by using deoxynucleotides complementary to two 18-nucleotide sequences of c-myb and c-fes encoding mRNA. After 5 days in culture, in several separate experiments with different oligomer preparations, more than 90% growth inhibition was observed in c-myb antisense-treated HL60 cells. At this time, independent of the differentiation inducer used, c-myb antisense-treated HL60 cells differentiate only along the monocytic pathway, whereas in sense oligomer-treated cultures, retinoic acid and dimethyl sulfoxide induced granulocytic differentiation. No perturbation of the HL60 cell growth was observed after 5 days of treatment with antisense c-fes oligomer. However, induction to granulocytic differentiation by retinoic acid and dimethyl sulfoxide resulted in progressive cell death, whereas monocytic differentiation by other differentiation inducers was only marginally affected. These results suggest that granulocytic, unlike monocytic, differentiation requires c-myb-conditioned proliferation and the activity of the protein encoded by c-fes.

Cell Cycle↗
PubMed1990

Detection of low abundance mRNA of myeloid specific genes in cells of acute and chronic lymphoid leukemias by cRNA hybridization.

The hybridization to a complementary RNA (cRNA) probe both in situ and in solution was used to assay tiny amounts of mRNA of the lactoferrin (LF) and myeloperoxidase (MPO) genes in normal bone marrow cells and in acute and chronic lymphoid leukemias. Evidence is reported that this technique is much more sensitive than the standard Northern blot technique. The LF mRNA was detectable in three of seven cases of acute lymphoblastic leukemia (ALL) and in three of seven cases of chronic lymphocytic leukemia (CLL). Four cases of ALL were also positive when tested with the MPO cRNA. It is apparent from these results that myeloid specific mRNA, different from MPO, may be detected in leukemic cells with lymphoid phenotype using a method more sensitive than the Northern blot technique. Whether or not the molecular events observed in these cell populations reflect events physiologically occurring rather than a deregulation of gene expression associated to leukemogenesis remains to be established.

Bone Marrow↗
PubMed1987

Chronobiologic aspects of recurrent transient ischemic attack.

An epidemiologic study was conducted from 1979 through 1984 on subjects presenting transitory ischemic attacks (TIA) and admitted into our Institute. We investigated year, season, month, day, and hour of every attack on 80 patients aged between 51 and 88 years. Time-series analysis showed a seasonal pattern of disease onset in early spring. Peaks occurred in March-April, and isolated peaks were also detected in January and October. Concerning TIA-onset day, we observed a peak distribution in the last 10 days of the month. Data on the hour of onset, according to single cosinor (mesor +/- SE = 2.67 + 1.13; amplitude +/- SE = 2.57 + 1.13), yielded a significant (P less than 0.05) acrophase. The acrophase is at -135 degrees (-93 degrees, -245 degrees) for tau = 48 hr.

Aged↗
PubMedDate not supplied

Circadian variation in the time of onset of acute gastrointestinal bleeding.

The increased attention to biologic rhythms and clinical manifestations of several diseases has recently led to the identification of "chronorisks" for certain pathologic events. To evaluate whether a temporal pattern exists for acute gastrointestinal bleeding, 369 consecutive patients with acute gastrointestinal bleeding observed at the emergency department (ED) of S. Anna Hospital of Ferrara, Italy, during a 3-year period (1988-1990) were studied. On presentation to the ED, 287 patients had upper gastrointestinal tract bleeding (UGB), and 82 patients had lower gastrointestinal tract bleeding (LGB). In 270 cases of UGB and in 75 cases of LGB, the hour of symptom onset was known and the data were analyzed for the number of observed versus expected events during the four 6-hour intervals of a day. The majority of events occurred in the morning (32.2% of UGB and 42.7% of LGB). Cosinor analysis yielded a circadian rhythmicity with a peak in the late morning to early afternoon for both UGB and LGB independent of sex and site of bleeding.

Acute Disease↗
PubMedDate not supplied

Circadian variation in the onset of acute myocardial infarction: lack of an effect due to age and sex.

The circadian patterns in the onset of symptoms of acute myocardial infarction were assessed in a prospective study involving 450 patients. Analysis of the data in the 424 patients in whom the time of onset was known did not show any statistically significant circadian rhythms, either for the group as a whole or for subgroups divided according to sex, age group (< 60, 60-69, 70-79 and > or = 80 years old), or the presence or absence of diabetes mellitus. The frequency of onset of symptoms was highest in the morning (06.01-12.00 h) for the group as a whole (29.2%). Patients aged < 70 and > or = 80 years old showed a peak in the morning, whereas patients aged 70-79 years old showed a peak in the afternoon (12.01-18.00 h).

Age Factors↗
PubMedDate not supplied

Fatal pulmonary embolism in hospitalized patients: evidence for a winter peak.

This study was intended to determine whether there are circa-annual variations in the incidence of fatal pulmonary embolism for hospitalized patients. Patients (152), admitted into both the medical and surgical departments of St. Anna Hospital of Ferrara, Italy, during an 8-year period (1983-1990) and who died in hospital as a result of pulmonary embolism, were considered. The day and month of death were registered, and analysed by inferential statistics (single cosinor). A circa-annual variation, with a statistically significant peak in late January (P = 0.002), was found for the total sample. After stratification by sex, this winter peak was confirmed only for women (P = 0.006).

Aged↗