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Biomedical subjects

M Pavia

Publications and source records attributed to M Pavia.

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

Transient increase in the risk of breast cancer after giving birth.

BACKGROUND: The effect of pregnancy on the risk of breast cancer is not clear. We tested the hypothesis that the risk of breast cancer increases transiently after pregnancy but then falls to a level below that of age-matched nulliparous women. METHODS: We conducted a case-control study of a nationwide cohort in Sweden, using a computerized record linkage between the Cancer Registry and the Fertility Registry. The study subjects were women born from 1925 through 1960 who were resident citizens of Sweden at the time of the 1960 census. A total of 12,666 patients with breast cancer were compared with 62,121 age-matched control subjects. We used conditional logistic regression to estimate odds ratios for the development of breast cancer at different ages, according to maternal age at first delivery (in uniparous as compared with nulliparous women) and age at second delivery (in biparous as compared with uniparous women). RESULTS: Uniparous women were at higher risk of breast cancer than nulliparous women for up to 15 years after childbirth and at lower risk thereafter. The excess risk was most pronounced among women who were older at the time of their first delivery (odds ratio 5 years after delivery among women 35 years old at first delivery, 1.26; 95 percent confidence interval, 1.10 to 1.44). Women who had two pregnancies had a less striking increase in risk. CONCLUSIONS: Pregnancy has a dual effect on the risk of breast cancer: it transiently increases the risk after childbirth but reduces the risk in later years. In women with two pregnancies, the short-term adverse effect is masked by the long-term protection imparted by the first pregnancy. A plausible biologic interpretation is that pregnancy increases the short-term risk of breast cancer by stimulating the growth of cells that have undergone the early stages of malignant transformation but that it confers long-term protection by inducing the differentiation of normal mammary stem cells that have the potential for neoplastic change.

Adult↗
PubMed1994

Dual effect of parity on breast cancer risk.

This study examined whether breast cancer risk increased for a short period after childbirth, but decreased after a longer period of time. Data from an international case-control study on breast cancer conducted in the 1960s were used to study the modifying effect of age at enrolment on the relationship between parity and breast cancer risk, comparing first uniparous with nulliparous women, and then biparous versus uniparous women. The statistical analysis was performed by modelling through multiple logistic regression, adjusting for study site, age at menarche, menopausal status and obesity index. Comparing uniparous with nulliparous women, an early age at birth seems to be protective for all periods after birth, whereas a late age at birth imparts a higher risk than nulliparity in the period immediately after birth, which declines with the passage of time. The modification effect by age was not apparent when biparous women with different age at second birth were compared with uniparous women. The results support the hypothesis that pregnancy oestrogens impart a transient increase of maternal breast cancer risk when the full-term pregnancy occurs late in a woman's life.

Adult↗
PubMed1994

Handedness, age at menarche, and age at menopause.

OBJECTIVE: To investigate the relation between handedness and age at menarche or age at menopause, as both handedness and reproductive variables have been suggested to be influenced by the intrauterine endocrine environment. METHODS: Self-reported information on handedness, age at menarche, age at menopause, and other demographic and reproductive variables was recorded for 10,328 women still menstruating or in natural menopause. These women had been selected as controls in a multicenter case-control study of breast cancer conducted in the 1960s. Left-handedness (including ambidexterity) was modeled as the outcome variable through multiple logistic regression. RESULTS: After adjusting for center, age, menopausal status, age at menopause, years of schooling, and parity, there was no significant relation of handedness to age at menarche (odds ratio for each year delayed 1.01, 95% confidence interval [CI] 0.97-1.06) or age at menopause (odds ratio 1.00, 95% CI 0.98-1.02). CONCLUSION: These findings lend no support to the hypothesis that intrauterine endocrine variables associated with handedness also are related to reproductive variables.

Adolescent↗
PubMed1994

Dentists and AIDS: a survey of knowledge, attitudes, and behavior in Italy.

OBJECTIVES: Italy, together with Spain, is second only to France in the total number of AIDS cases in Europe, with over 16,800 as of March 1993. The purpose of this study was to evaluate knowledge, attitudes, and behavior concerning AIDS and infection control among Italian dentists. METHODS: A questionnaire was mailed to 1,000 dentists randomly selected from the Italian Dental and Maxillo-Facial Association's register of dentists. RESULTS: Of the 715 dentists responding, 70.7 percent of dentists knew all the main risk groups able to transmit the infection and that semen is a biologic fluid potentially contaminated by HIV virus. This knowledge was greater if the number of patients per week was not higher than 55 and if the dentist had had a previous contact with an HIV-seropositive patient. Only a few (21.1%) knew all the oral manifestations of AIDS. Over 65 percent of the dentists indicated that they would treat HIV-seropositive patients (71.9%) or those with AIDS (66.8%). Dentists were more willing to care for an HIV-seropositive patient if they were involved in specialties with high blood contact, if they had a previous contact with an HIV patient, as the average number of patients per week increased, and if they did not consider saliva as a possible route of transmission of HIV. A small percentage of dentists who had the opportunity to treat patients at risk for AIDS (12.1%) or HIV seropositive (9.4%) refused to treat them. Willingness to treat was the most significant predictor of actual treatment of an infected patient. Only 24.4 percent routinely used all barrier techniques (gloves, masks, and protective eyewear). Predictors of routine use of all barrier techniques were specialties with high blood contact, considering saliva a possible route of transmission of HIV infection, average number of patients per week fewer than 40, and number of years of practice. CONCLUSIONS: Educational efforts for improving knowledge and finding and implementing ways to motivate dentists to the correct and routine use of infection control procedures are needed.

AIDS-Related Opportunistic Infections↗
PubMed1994

[Subarachnoid hemorrhage: assessment in the acute phase with angiography, with high-resolution magnetic resonance (angio-MR)].

Previous reports demonstrated that Magnetic Resonance Angiography (MRA) is a reliable means of diagnosing intracerebral aneurysms. However, in these early studies MRA was performed in patients with cerebral aneurysms already proved by intraarterial angiography. Our study was aimed at investigating the clinical feasibility and the diagnostic accuracy of high-resolution MRA in patients with acute subarachnoid hemorrhage. Twenty-five patients (15 women, 10 men) with CT diagnosis of subarachnoid hemorrhage were prospectively examined with high-resolution MRA within 24 hours of bleeding. All patients underwent intraarterial digital subtraction angiography (IA DSA) immediately after MRA examination. MRA studies were performed with a 1.5-T unit. MRA examinations of the cerebral vessels consisted of axial excitation of two 50-mm volume slabs, with 25% overlap, covering the cerebral circulation from the vertebro-basilar junction to the pericallosal artery. Pulse sequence variables were optimized to reduce voxel size (0.62 x 0.62 x 0.78) and to increase spatial resolution (160-mm FOV, 256 x 256 matrix, 0.78-mm slice thickness) while keeping S/N ratio high. The maximum intensity projection (MIP) reconstruction algorithm was used. The examination lasted nearly 20 minutes. Four MRA examinations (16%) were considered inadequate for diagnosis because of motion artifacts. High-resolution MRA detected 20 of 21 aneurysms in 17 patients, with 1 false positive and 1 false negative. Two patients had multiple aneurysms, 2 and 4 respectively, all of them detected by MRA. No cause of subarachnoid hemorrhage was found by IA DSA in 4 patients, while MRA studies were considered negative in 3 patients. Nineteen aneurysms were surgically clipped, while 2 basilar artery aneurysms were occluded by intravascular treatment. MRA and DSA findings were compared with surgical findings. Relative to IA DSA, MRA exhibited 95% sensitivity and 95% specificity. Aneurysm size ranged 2-10 mm: the smallest aneurysm detected by MRA was 2.5 mm. Anatomical and morphological agreement between MRA and IA DSA was excellent, with only slight MRA underestimation of the aneurysm size in 25% of cases and overestimation in 15% of cases. The aneurysm neck was shown by MRA in 60% and by IA DSA in 81% of cases. High-resolution MRA proved to be especially useful in complex anatomical sites where the direction of the aneurysm could be clearly demonstrated through the accurate selection of the appropriate projection angle and the careful examination of direct axial images.(ABSTRACT TRUNCATED AT 400 WORDS)

Acute Disease↗
PubMed1993

Parity and hepatocellular carcinoma. A population-based study in Sweden.

The association between parity and hepatocellular carcinoma (HCC) was studied using a data-base generated by linking 2 Swedish nation-wide registries; the Cancer Registry and the Fertility Registry. Among women born between 1925 and 1960, 133 patients with HCC recorded in the Cancer Registry between 1958 and 1984 were compared with 665 age-matched controls. In this nested case-control study there was no positive association between parity, age at first birth or frequency of twinning on the one hand, and risk of HCC on the other. It appears that the positive association between parity and HCC previously reported is limited to cases of HCC caused by chronic infection with hepatitis B virus; these cases represent only a small fraction of HCC cases in Sweden.

Adult↗
PubMed1993

Parity and cancers of the gall bladder and the extrahepatic bile ducts.

The relation of parity and age at first birth to cancers of the gall bladder and extrahepatic bile ducts in women was studied using a database generated by linking 2 Swedish national registries; the Fertility Registry and the Cancer Registry. Among women born between 1925 and 1960, 257 cases of gall-bladder cancer recorded in the Cancer Registry between 1958 and 1984 were compared with 1,285 controls, age-matched to cases in a 5:1 ratio. In addition, 60 cases of extrahepatic-bile-duct cancer were matched with 300 controls. There was a positive association between number of live births and risk of gall-bladder cancer (p 0.06), but simultaneous consideration of parity and age at first birth revealed a more complex picture. Parity increases the risk for cancer of the gall bladder when the first birth occurs before the age of about 25 years, whereas parity associated with first birth after the age of about 30 years is associated with reduced risk for the disease. Thus, among parous women there is a highly significant inverse association of age at first birth with risk for gall-bladder cancer after adjustment for number of live births. Variable levels of pregnancy estrogens according to maternal age and variable effects of parity on non-pregnancy estrogens by age, may explain the observed pattern. The results on extrahepatic-bile-duct cancer, parity and age at first birth did not indicate the existence of an association in either direction.

Adult↗
PubMed1993

Breast cancer risk in mothers of multiple births.

Data from an international case-control study of breast cancer that was conducted in the 1960s were used to examine whether multiple births affect the risk of breast cancer in the mother. Among 2821 parous breast-cancer patients, 88 had had one or more multiple births, whereas among 8882 controls 247 had had one or more multiple births; the logistic-regression-adjusted odds ratio (OR) was 1.21, the 95% confidence interval (CI), 0.94 to 1.55. The OR was significantly elevated during the 15-year period following the latest multiple birth (1.76; CI, 1.12 to 2.75), but declined toward the null afterwards. A late first pregnancy imparted a substantially higher breast-cancer risk when it was multiple rather than singleton; the OR was 2.34 for a multiple and 1.48 for a singleton first pregnancy when the cutoff point was 30 years, and 4.58 and 1.57, respectively, when the cutoff point was 35 years. Since multiple pregnancies are characterized by higher levels of pregnancy estrogens, the results of this study would be compatible with the hypothesis that these hormones may be responsible for the transient increase in breast-cancer risk following a term pregnancy and, in particular, a multiple term pregnancy. The long-term reduction of breast-cancer risk is probably due to a different mechanism, most likely the terminal differentiation of susceptible mammary-gland cells.

Adult↗
PubMed1991

Cartilage synthesizes the serine protease inhibitor PAI-1: support for the involvement of serine proteases in cartilage remodeling.

The work described here demonstrates the synthesis by human articular cartilage of plasminogen activator inhibitor-1 (PAI-1), a potent inhibitor of the serine protease tissue plasminogen activator (tPA). We also present data demonstrating an increase in PAI-1 messenger ribonucleic acid (mRNA) in chondrocytes exposed to the cytokine interleukin-1 (IL-1). Interestingly, this elevation of steady-state mRNA levels does not appear to result in an increase in synthesis of PAI-1 protein. Northern blot analysis reveals that of the two mRNA species (3.4 kb, 2.4 kb) previously reported for PAI-1, only the larger species (3.4 kb) appears to be synthesized by chondrocytes. Our data demonstrate the IL-1-stimulated production by cartilage of tissue plasminogen activator. We also show evidence for the presence of plasminogen in cartilage. A scheme is presented indicating the probable importance of the serine proteases (tPA and plasminogen) and PAI-1 in cartilage degradation.

Blotting, Northern↗
PubMed1989

[Use of myocardial thallium-201 scintigraphy in the evaluation of infarct area].

In twenty-four patients admitted of the Coronary Care Unit for myocardial infarction, without signs of previous necrosis and uncomplicated course, amplitude of infarct size was estimated by 201-Thallium perfusion scintigraphy. The obtained results were compared with residual ventricular function (i.e. angiographic ejection fraction) and with other methods of fibrotic area evaluation such as electrocardiographic score and CPK and CK-MB dismission curve. Concordance was observed among: scintigraphy and ejection fraction, scintigraphy and electrocardiographic score, scintigraphy and CPK peak.

Adult↗
PubMed1986

Purification and characterization of collagenase activator protein synthesized by articular cartilage.

We have isolated an activator of collagenase from medium conditioned with articular cartilage. The activity is contained in an acidic protein appearing as a doublet band of Mr 57,000 and 56,000 on sodium dodecyl sulfate polyacrylamide gels. Both components of the doublet have identical isoelectric points as demonstrated by gel electrophoresis. Purified synovial collagenase has a high dependence on the presence of this factor for activity. Other known activators of latent proteolytic enzymes such as trypsin and mercurials will stimulate collagenase but only if activator protein is present. The activator protein is itself a latent metalloprotease because in the presence of p-aminophenylmercuric acetate and calcium it will digest casein. The caseinase activity and collagenase activation activity have identical heat inactivation profiles, both being stable to a temperature of 60 degrees C and partially inactivated at 80 degrees C. The synthesis of the activator is localized in the superficial zone of articular cartilage.

Animals↗
PubMed1986

Stimulation of the synthesis of collagenase activator protein in cartilage by a factor present in synovial-conditioned medium.

We have purified a low molecular weight protein from medium conditioned by calf synovium with physical and biological properties similar to the leukocyte cytokine interleukin 1 (IL-1). The factor is active in stimulating the synthesis (three- to fivefold) of collagenase activator protein (CAP) by the surface (1-2 mm) of articular cartilage while CAP synthesis in the deeper zones of articular cartilage is not affected. Recombinant mouse IL-1 and commercially available purified human IL-1 are also capable of stimulating cartilage to synthesize and secrete CAP. The synthesis of other proteins, including collagenase, appeared to be unaffected by either the synovial factors or the human and mouse IL-1.

Animals↗
PubMed1982

[Intravenously disopyramide phosphate administration for treatment of arrhythmias].

Disopyramide phosphate (DF) was administered intravenously to 50 patients during 55 episodes of arrhythmias. The mean dosage employed was 2 +/- 1.4 mg/kg over a period of 3 minutes to 60 minutes (mean 16 +/- 6'), followed by an infusion at a dose of 0.4 mg/kg/hr in 9 cases. Atrial premature beats were suppressed in 3 of 4 treated cases (75%). Conversion to sinus rhythm was achieved in 4 of 5 (80%) cases of paroxysmal supraventricular tachycardia, unresponsive to vagal maneuvers in 7 of 10 cases (70%) of atrial flutter of recent onset (less than 48 hours) and in 13 of 17 (76%) cases of atrial fibrillation (less than one week in duration). In 9 of 11 cases (81%) with frequent, multiform, repetitive ventricular premature beats and in 7 of 8 cases (87%) of ventricular tachycardia, DF completely suppressed the arrhythmia. The drug increased sinus rate, PR and QRS intervals, but the difference was not statistically significant: the QRS of patients with complete bundle branch block and the QTc interval were significantly prolonged. Severe hypotension was observed in 10 patients after DF i.v., in 5 of whom withdrawal of therapy was deemed to be necessary. Nine other patients had anticholinergic side effects. Our study shows that DF administered i.v. can be used successfully in 75% of supraventricular arrhythmias and in 82% of ventricular arrhythmias.

Adult↗