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Biomedical subjects

M Bo

Publications and source records attributed to M Bo.

At least 37 records · Page 2Linked to original sources
PubMed1994

Carotid plaque, aging, and risk factors. A study of 457 subjects.

BACKGROUND AND PURPOSE: The aim of this study was to assess the prevalence of extracranial carotid artery atherosclerosis and its relation to principal cardiovascular risk factors at different ages in a sample of the general population. METHODS: B-mode ultrasonography was used to investigate the carotid district in 457 subjects (231 men and 226 women; mean age, 55.4 +/- 18.7 years; range, 18 to 97 years) in the metropolitan area. The ultrasonographic findings were then related to risk factors. RESULTS: Carotid plaques were found in 178 subjects (38.9%). The prevalence of atherosclerosis, number of plaques, and severity of stenosis were observed to increase with age. Age (P < .0001), cigarette smoking (P < .0001), male sex (P < .001), total cholesterol (P < .05), and, inversely, the ratio of high-density lipoprotein cholesterol to total cholesterol (P < .05) were found to be independently associated with carotid atherosclerosis. Stratified analysis by sex and age showed effect modifications by age on cigarette smoking, total cholesterol, and the ratio of high-density lipoprotein cholesterol to total cholesterol. After multivariate analysis including interaction terms, cigarette smoking and cholesterol levels were not longer found to be associated with carotid atherosclerosis in elderly subjects. Age (P < .01), total cholesterol (P < .05), and diabetes (P < .05) were positively related to the severity of vascular narrowing. CONCLUSIONS: There is a high prevalence of asymptomatic carotid atherosclerosis in the general population, particularly among the very old. The association between risk factors and carotid atherosclerosis is less pronounced in the elderly than in younger subjects.

Adolescent↗
PubMed1994

Stage-specific expression of c-myc messenger ribonucleic acid in porcine granulosa cells early in follicular growth.

In the present study, the expression of c-myc mRNA in porcine granulosa cells harvested from varying follicle stages was analyzed using northern blot hybridization with a c-myc probe, and compared during follicular growth. Northern blot analysis revealed that porcine granulosa cell RNA obtained from small (1-2 mm) follicles contained an abundance of c-myc transcript of 2.4 kb, the size of which was identical to the c-myc transcript obtained with human early placental RNA used as the control. In contrast to small-follicle granulosa cell RNA, total RNA preparations from either medium (3-5 mm)-follicle granulosa cells or large (6-11 mm)-follicle granulosa cells exhibited no detectable transcripts with the c-myc probe. These results suggest that expression of c-myc mRNA in porcine granulosa cells is limited only at the early stage of follicular growth. The stage-specific expression of c-myc mRNA in granulosa cells early in follicular growth may play a physiological role in the autonomous growth of immature granulosa cells in early folliculogenesis, seemingly independent of pituitary gonadotropic stimulation.

Animals↗
PubMed1994

Risk factors for atherosclerosis and aging.

In order to investigate the association between atherosclerosis and risk factors in aged subjects, Doppler ultrasound scans were used to identify the presence and severity of carotid and femoral atherosclerosis in a sample of 457 community living subjects (mean age 55.4 +/- 18.7 years) of the metropolitan area; the ultrasonographic findings were then related to primary cardiovascular risk factors. Carotid and femoral plaques were found respectively in 178 (38.5%) and in 180 (39.4%) subjects. Prevalence of atherosclerosis, number of plaques and percentage of stenosis have been observed to increase with age. All the main cardiovascular risk factors (age, male sex, hypertension, cigarette smoking, diabetes and hypercholesterolemia) resulted significantly associated with both carotid and femoral atherosclerosis in the total series and, more strongly, in subjects aged under 65. On the contrary, most of these associations disappeared in subjects aged 65 or more. Multiple logistic regression analysis confirmed that in this age group only age and male sex were independently associated with carotid and femoral atherosclerosis; of the other risk factors cigarette smoking alone was an independent risk factor for femoral atherosclerosis. We conclude that in the elderly, in spite of the age-related increase in carotid and femoral atherosclerosis, the association between risk factors and atherosclerotic disease is less relevant than at younger ages.

Age Factors↗
PubMed1993

Autopsy and multiple pathology in the elderly.

We examined autopsy reports and the clinical diagnoses of 600 patients (200 in 1967 and 400 in 1987). For each patient we considered age, diagnostic error, main diseases and presence of multiple pathology. The number of diagnostic errors increased from 1967 to 1987. The diagnostic error was particularly high for pulmonary embolism and septic shock and significantly higher in patients > 65 than < or = 65 years old. Multiple pathology was higher in old patients: we found 4 or more diseases in 195/270 (72.2%) patients > 65 years and in only 135/330 (40.9%) patients < or = 65 years. The average period of hospitalization was directly proportional to the number of diseases present in the same patient.

Age Factors↗
PubMed1993

Risk factors for atherosclerosis: ultrasound evaluation of carotid and femoral arteries in patients examined by coronary angiography.

The carotid and femoral arteries of 209 subjects (161 men and 48 women), consecutively tested by coronary angiography during the first four months of 1990, were examined using a B-Mode Echo-doppler. The angiographic examination was performed for suspected ischemic disease or to complement hemodynamic tests for valvular cardiopathy. The relationship between the main risk factors and the degree of atherosclerotic vascular involvement in the coronary, carotid and femoral districts was examined using standardised partial correlation coefficients. Cigarette smoke (expressed as number of cigarettes per day or as duration of exposure to smoke), total blood cholesterol concentration and age were positively correlated with the degree of atherosclerotic involvement in all three vascular regions; triglyceridemia values were correlated only in the coronary region. These relations were observed both in patients below and above 65 years of age; in the elderly group no correlation was found between blood cholesterol concentration and coronary involvement and between triglycerides levels and atherosclerotic disease in the three districts. Our results suggest that some risk factors (high blood cholesterol concentration and history of smoking) correlate with severity of atherosclerotic involvement even in advanced age.

Age Factors↗
PubMed1993

Emergency surgical treatment for total left main coronary artery occlusion. A report of 2 cases.

Treatment of total left main coronary artery occlusion is rarely reported (84 chronic and acute cases in the world literature), due to the high mortality rate from massive myocardial infarction. Acute occlusions have been treated with intracoronary streptokinase, with percutaneous transluminal coronary angioplasty, or with both. To date, there has been no report of successful surgical revascularization in an acute case. We present 2 cases of surgically treated patients who survived total left main coronary artery occlusion that appears to have been acute, or acutely evolving. Both patients had an 80% or greater stenosis of the right coronary artery, yet have remained in New York Heart Association functional class I or II postoperatively. We attribute this not only to the aggressive surgical approach, which enabled reperfusion to be achieved within 2 hours of total occlusion, but to the protective effect in these patients of right coronary-to-left anterior descending collaterals.

Aged↗
PubMed1993

[Ischemic stroke and transient ischemic attacks: a case-control study of the risk factors in elderly hospitalized patients].

We have evaluated in a case-control study the association of the main risk factors with cerebrovascular ischemic accidents in elderly patients. Two hundred and twenty patients aged 65 year or more (average age 77.3 +/- 7.3 yr, 93 males and 127 females) admitted to our Division for stroke (122) or transient ischemic attacks (TIA) (98) were enrolled: 220 hospitalized patients, age and sex-matched, without actual or previous cardiovascular clinical manifestations were the control group. Advanced senile decay, hepatic or renale failure and malignancies were considered exclusion criteria for both groups. The following risk factors have been considered: family history, obesity, cigarette smoking, diabetes, hypercholesterolemia, hypertriglyceridemia, atrial fibrillation, left ventricular hypertrophy, and related continuous variables. After logistic multiple regression analysis, atrial fibrillation, hypertension and blood cholesterol concentration above 240 mg/dl were significantly and independently associated with stroke, while only hypertension and hypercholesterolemia were associated with TIA. The unexpected finding of a significant association between hypercholesterolemia and cerebrovascular ischemia seems attributable to the choice of hospitalized patients as control group. These results indicate that hypertension and atrial fibrillation are independently associated with ischemic stroke even in advanced age.

Aged↗
PubMed1992

Identification of the transcriptionally active genes of the chorionic gonadotropin beta gene cluster in vivo.

The chorionic gonadotropin beta (CG beta) subunit is encoded by a multigene cluster composed of six homologous sequences (genes or pseudogenes). They are primarily distinguished by sequences in the 5' nontranslated region of the first exon. To determine which CG beta genes are active in vivo, we employed the reverse transcription-polymerase chain reaction technique. DNA complementary to RNA from placenta tissue and a choriocarcinoma cell line was subjected to polymerase chain reaction with CG beta-specific primers. The amplified DNA was cloned into M13 and sequenced. Most of steady-state CG beta mRNAs are transcribed from CG beta genes, 5, 3, and 8. The level of expression is beta 5 greater than beta 3 = beta 8 greater than beta 7, beta 1/2. Transcripts from the CG beta 1 and CG beta 2 genes, which were previously considered pseudogenes because of their noncanonical splice site, were detected. These CG beta transcripts arising from alternative splicing sites in the CG beta 1/2 genes were also detected in polysomes which suggests they are translation-competent. Northern blotting with a CG beta 1/2 probe revealed low amounts of CG beta 1/2 transcripts which were smaller than the transcripts of the other genes. The results indicate that at least five, and possibly all six, CG beta genes are transcribed in vivo, and at least one of them (CG beta 1 and/or CG beta 2) undergoes alternative splicing.

Base Sequence↗
PubMed1992

A four year clinical and echographic follow-up of asymptomatic carotid plaque.

Eighty-five patients with asymptomatic carotid plaque--a diagnosis revealed by B-mode high-resolution echotomography--were followed up for four years; the echoplaque changes were compared with the clinical history. Eight patients died (2 from stroke, 4 from myocardial infarction, and 2 from lung tumor) and were excluded from the follow-up. Three patients underwent carotid thromboendarterectomy (TEA) (1 bilateral), and these 4 carotids were not considered in the total series. At the first echo Doppler evaluation of 150 carotids, plaques were observed in 112; 38 vessels were free of lesions. Of the 150 carotids, 8 revealed a new plaques. In regard to the echogenic pattern, 95 of the 112 plaques (84.8%) remained unchanged, 16 (14.3%) progressed, and regression of a small homogeneous plaque was observed in 1 patient (0.9%). An increase of the degree of vascular stenosis, was observed in 23 of the 150 carotids (15.3%). Cerebral ischemic symptoms occurred in 5 patients. In 1 patient who suffered from stroke, a new, soft, dyshomogeneous plaque in the carotid of the side of the lesion was observed. In 3 patients (2 with strokes, 1 with transient ischemic attack) the occlusion of a previous severe stenosis was observed. The fifth patient had a stroke on the side of an unchanged, ulcerated hemodynamic lesion. A valid criterion for identifying a risky plaque should be the joint evaluation of the echostructural characteristics and the degree of stenosis.

Arteriosclerosis↗
PubMed1992

[Lipid parameters and cardiovascular risks in elderly patients hospitalized for ischemic cardiopathy. A case-control study].

In order to evaluate whether and to what extent elevated blood lipid concentrations and clinical expressions of coronary heart disease (CHD) are associated in the elderly, we studied the risk of CHD (myocardial infarction and angina pectoris) in a population of elderly hospitalized patients (210 subjects, 126 men and 84 women, average age 76 +/- 6 years) exposed to risk factors. 210 patients, free from current and previous cardiovascular diseases, age and sex matched, were recruited as the control group. Advanced senile decline, severe hepatic or renal failure and malignancies were considered exclusion criteria for both groups. The following dichotomic variables (familial history of CHD, cigarette smoking, clinical history of arterial hypertension or diabetes mellitus, hypercholesterolemia, hypertriglyceridemia) and continuous variables (total, LDL and HDL cholesterol, triglycerides, total/HDL cholesterol ratio, body mass index (BMI), years of exposure to risk factors) were considered. Using a stepwise multiple logistic regression forward method, the following variables resulted significantly associated with the risk of CHD: total/HDL cholesterol ratio (OR 1,89), BMI (OR 1,04), period of hypertension (OR 1,04) and cigarette smoke exposure (OR 1,007). We conclude that in the elderly the total/HDL cholesterol ratio can be a more predictive and reliable index of coronary risk than blood total cholesterol concentration.

Aged↗
PubMed1992

[Prevalence and risk factors of carotid and femoral atherosclerosis in a sample of the city of Turin].

Presence and severity of carotid and femoral atherosclerosis, in relation to the principal cardiovascular risk factors, have been non invasively evaluated using echodoppler in a sample of 457 subjects (average age 55.4 +/- 18.7 years) of the metropolitan area of Turin. Data of prevalence have been standardized for age and gender in order to obtain an estimate of prevalence representative of the city. In both districts, prevalence of lesions, echo structural characteristics of the plaques and related degree of stenosis have been considered. Results indicate a high prevalence of carotid and femoral atherosclerosis (38.5% and 39.4% respectively), and, particularly, of concomitant involvement of both districts (30%). Prevalence of the lesions and degree of stenosis rise with advancing age; nevertheless stenosis > 75% were not found among the oldest patients. Bifurcations were the most frequent site of lesion and the "hard" echo structure was the most commonly represented, especially in subjects over 45 years. After multiple logistic regression model both carotid and femoral atherosclerosis were strongly and independently associated with age, male sex, smoke of cigarette and plasma cholesterol concentration.

Adolescent↗
PubMed1992

[The relationships between the lipoprotein profile and rheological-coagulation parameters in patients with hyperlipoproteinemia type II].

The aim of the study was to evaluate the direct influence of lipid parameters (total and HDL-cholesterol, triglycerides and total lipids) on the rheologic-coagulative pattern. We studied blood rheological properties--blood (BV), plasmatic (PV), and seric (SV) viscosity, whole blood (WBF) and red cell (RCF) filterability--and some coagulative factors--fibrinogen (Fib), levels of clotting factor VII (fVIIc) and VIII (fVIIIc) activity--in 156 men aged 40-54 years; 87 patients had type II hyperlipoproteinemia (46 type IIa and 41 type IIb) and 69 were normolipemic controls. Smokers, patients with arterial hypertension, diabetes mellitus or cardiovascular clinical manifestations were excluded. Type IIb hyperlipoproteinemic patients had increased blood viscosity (shear rate 225 sec-1, p. less than 0.01), which was positively correlated with triglycerides and fibrinogen concentration. Levels of fibrinogen, fVIIc and fVIIIc activity did not differ significantly in hyperlipemic patients and controls, although fVIIc activity and fibrinogen were both positively related with lipid parameters. These data suggest that, in absence of other major risk factors, the alterations of the rheologic-coagulative pattern are mainly dependent on the severity of the lipid disorder.

Adult↗
PubMed1991

Post-translational processing and secretory pathway of human atriopeptin in rat pheochromocytoma cells.

Atriopeptin (AP) is expressed in several tissues with each tissue capable of specific differences in processing of the prohormone (pro-AP) to mature low molecular forms of the peptide. Since pro-AP has low biological activity, processing into mature AP is a critical activation event. This observation prompted us to study whether granule storage or regulated secretion of AP is essential for cleavage of mature peptide. We examined the processing of AP in adrenal medulla derived cells, using the rat pheochromocytoma cell line (PC12 cell) stably transfected with a genomic human AP DNA in the presence and absence of nerve growth factor (NGF), and also examined the mechanism of AP secretion and compared the results with those obtained using transfected chinese hamster ovary cells (CHO cells). The amount of prohormone was 5-10 fold higher than that of low molecular form of AP in the transfected PC12 cells. This ratio was essentially unchanged in differentiated PC12 cells after NGF treatment of the cells. Potassium depolarization of the transfected PC12 cells caused a 5-fold increase in AP release into the medium primarily as the intact prohormone. On the other hand, transfected CHO cells only exhibited constitutive AP release which is non-response to depolarization. These results suggest that the AP prohormone is sorted into secretory granules as the prohormone in PC12 cells and undergoes regulated release in response to depolarization indicating granule storage or release is not the critical determinant of AP prohormone cleavage.

Adrenal Gland Neoplasms↗
PubMed1991

Hemorheologic and coagulative pattern in hypercholesterolemic subjects treated with lipid-lowering drugs.

The effects on the coagulative and rheologic pattern of two lipid-lowering drugs, bezafibrate and simvastatin, were studied in 36 hypercholesterolemic subjects. Patients were randomly divided into two groups (18 subjects each) and received bezafibrate R 400 mg/day or simvatatin 10-40 mg/day over a twelve week period. Besides a decrease in plasma fibrinogen and fibrinopeptide A (p less than 0.001 both), bezafibrate induced a reduction of factor VIIc and VIIIc activity (p less than 0.001 both), while antithrombin 3 activity was increased (p less than 0.001) and the hemorheologic pattern was greatly improved (p less than 0.001). Simvastatin caused a slight decrease in factor VIIIc activity and a moderate reduction of beta-thromboglobulin. The efficacy of bezafibrate in reducing the activation of the coagulative cascade and improving the hemorheologic pattern has been confirmed; the peculiar triglycerides- and fibrinogen-lowering effect of the drug, not observed with simvastatin, could be responsible for these modifications.

Adult↗
PubMed1991

Expression of human luteinizing hormone (LH) receptor: interaction with LH and chorionic gonadotropin from human but not equine, rat, and ovine species.

Studies on human LH receptors are difficult due to the limited availability of clinical samples. Recent cloning of rat and porcine LH receptor cDNAs indicated that these binding sites are single polypeptides of the G-protein-coupled receptor family with seven transmembrane domains. Based on the conserved sequences of rat and porcine receptors, we performed reverse transcription polymerase chain reaction, using human ovarian mRNA as template and obtained partial human LH receptor cDNA clones. Further screening of a human ovary cDNA library and subsequent ligation of individual cDNA clones generated a human LH receptor cDNA containing the entire amino acid-coding region. Sequence analysis indicated that the human receptor cDNA displays 89% and 82% homology at the nucleotide level with its porcine and rat counterparts, respectively. A region spanning the second extracellular and third transmembrane domains is highly conserved among the human LH, FSH, and TSH receptors. The ovarian LH receptor clone is, however, significantly different from an incompletely spliced LH receptor cDNA recently obtained from a human thyroid library. Unlike the thyroid clone, the ovarian LH receptor cDNA could be expressed in the human fetal kidney cell line (293), and radioligand receptor assay identified high affinity (Kd, 1.2 x 10(-10) M) LH/hCG-binding sites on the plasma membrane. Binding specificity of the human LH receptor was studied using recombinant human CG, LH, and FSH secreted by CHO cells transfected with the respective genes. Human CG and LH displaced [125I]hCG binding with an ED50 of 4.3 and 4.8 ng/ml, respectively. In contrast, recombinant FSH was not effective. Treatment of transfected cells with recombinant gonadotropins also induced dose-dependent increases in extracellular cAMP production (hCG = LH much greater than FSH; ED50 25, 10, and greater than 3000 ng/ml). Although equine, rat, and ovine LH as well as equine CG competed effectively for rat testicular LH receptor binding, these hormones were unable to displace [125I]hCG binding to the human receptor, suggesting evolutionary changes in receptor binding specificity and the importance of using human receptors for clinical studies. Thus, the cloning and expression of the human LH receptor cDNA allowed analysis of interactions between human LH receptor and gonadotropins from diverse species. The present work should provide the basis for future design of therapeutic agents capable of interacting with the human receptor and for understanding the structural basis for LH receptor binding to different gonadotropins.

Amino Acid Sequence↗
PubMed1991

[Treatment of hypercholesterolemic patients of different age with simvastatin: 1-year study].

Nowadays there is no direct evidence that lowering cholesterol may reduce the CHD in the elderly; however, several evidences suggest the potential benefit of a dietetic and/or pharmacologic intervention in healthy young-old hypercholesterolemics. In this study we evaluated the efficacy and tolerability of simvastatin, alone or in combination with cholestyramine, in two groups of patients (group A: age 30-55 years and group B: age 60-75 years) with primary hypercholesterolemia, over a 48-week period. In both groups Simvastatin induced a significant reduction in total and LDL cholesterol (p less than 0.001 both), with a decrease of the total/HDL cholesterol ratio (p less than 0.001). A reduction of the apo-B100 levels was also observed (respectively p less than 0.01 and p less than 0.001) with a significant improvement of the apo-B100/apo-A1 ratio (p less than 0.01). Simvastatin was well tolerated and free of remarkable side effects in both groups.

Adult↗
PubMed1988

Newer data on the configuration and variability ranges of body surface maps in a sample of normal subjects.

Quantitative data on the normal variability of body surface maps (BSM) are scarce in the literature. This is one of the reasons why BSM are not yet widely used in clinical practice despite their superior information contents. In this study we determined the average value and variability of a number of parameters derived from BSM in a group of 36 normal adult males, ages 22 to 60. Forty to 60 homogeneous beats were averaged for each subject. This enabled us to extend our study to the low voltage intervals (P,PQ,ST,U) which encompass more than 60% of the entire P-U duration and to contribute new data to controversial issues, such as the presence of two simultaneous maxima during atrial excitation. The following parameters were measured: a) the coordinates of the absolute potential maximum and minimum on the chest surface during the entire cardiac cycle; b) the time course of four voltage-related functions, namely: highest instantaneous potential value on the chest surface, lowest (most negative) potential, highest potential difference, and surface integral of the absolute value of the potential function. In recent studies these parameters were shown to be of considerable value in discriminating normal subjects from different categories of cardiac patients.

Adult↗