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Biomedical subjects

M Carta

Publications and source records attributed to M Carta.

At least 19 recordsLinked to original sources
PubMed1992

Chemoprevention of rat liver carcinogenesis by S-adenosyl-L-methionine: a long-term study.

Previous work has shown a consistent fall in S-adenosyl-L-methionine (SAM) in the liver of diethylnitrosamine-initiated rats, during the development of preneoplastic lesions, in persistent nodules (PNs), and hepatocellular carcinomas. The injection of SAM into rats causes the reconstitution of the SAM pool, coupled with growth restraint, remodeling, and apoptosis of preneoplastic cells, and inhibits the development of PNs and hepatocellular carcinomas. To evaluate if SAM treatment causes a long-term prevention of preneoplastic and neoplastic liver lesions or merely causes a delay in their development, we evaluated the effect of a relatively short SAM treatment on the development of preneoplastic and neoplastic lesions in a long-term study. Male Wistar rats were subjected to initiation with diethylnitrosamine, followed by selection and then by the administration of phenobarbital for 16 weeks. After selection, the rats were given i.m. injections of a purified SAM preparation (384 mumol/kg/day) for 24 weeks. In SAM-treated rats, a decrease in the incidence of PNs was found 6, 14, and 24-28 months after initiation. At the end of SAM treatment the number of PNs per rat liver, nodule diameter, and labeling and mitotic indices of nodular cells decreased considerably in control rats. Nodule diameter started to increase rapidly again only 8 months after arresting SAM treatment, when complete recovery of DNA synthesis in nodular cells occurred. The majority of nodules present in the liver 6-28 months after initiation belonged to the clear and acidophilic cell types, with lower percentages of mixed cell and basophilic cell types. A decrease in basophilic nodules occurred in SAM-treated rats. Fourteen and 24-28 months after initiation hepatocellular carcinoma incidence was 11 of 12 and 10 of 10 in control rats, respectively, and only 1 of 12 and 3 of 11 in SAM-treated rats. At the 24th-28th month all control rats had tumors identified as 2 poorly differentiated carcinomas, 6 trabecular carcinomas, or 3 adenocarcinomas, while only 2 relatively small trabecular carcinomas and 1 small glandular tumor developed in SAM-treated rats. In 3 of 11 SAM-treated rats, but in none of the control rats, leukemic infiltration of liver occurred 24-28 months after initiation. Leukemic infiltration of the spleen occurred in 5 and 3 control and SAM-treated rats, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1992

Comparison of subcutaneous low-molecular-weight heparin with intravenous standard heparin in proximal deep-vein thrombosis.

In view of the potential of low-molecular-weight heparins (LMWH) to simplify initial therapy and allow outpatient treatment of proximal deep-vein thrombosis, we undertook a randomised comparison of fixed-dose subcutaneous LMWH with adjusted-dose intravenous standard heparin in the initial treatment of this disorder. Our main objectives were to compare the efficacy of these regimens for 6 months of follow-up and to assess the risk of clinically important bleeding. Of 170 consecutive symptomatic patients with venographically proven proximal deep-venous thrombosis, 85 received standard heparin (to achieve an activated partial thromboplastin time of 1.5 to 2.0 times the pretreatment value) and 85 LMWH (adjusted only for body weight) for 10 days. Oral coumarin was started on day 7 and continued for at least 3 months. The frequency of recurrent venous thromboembolism diagnosed objectively did not differ significantly between the standard-heparin and LMWH groups (12 [14%] vs 6 [7%]; difference 7% [95% confidence interval -3% to 15%]; p = 0.13). Clinically important bleeding was infrequent in both groups (3.5% for standard heparin vs 1.1% for LMWH; p greater than 0.2). We conclude that fixed-dose subcutaneous LMWH is at least as effective and safe as intravenous adjusted-dose heparin in the initial treatment of symptomatic proximal-vein thrombosis. Since there is no need for laboratory monitoring with the LMWH regimen, patients with venous thrombosis can be treated at home.

Aged↗
PubMed1991

A new computerized impedance plethysmograph: accuracy in the detection of proximal deep-vein thrombosis in symptomatic outpatients.

Because of the lack of specificity of the clinical diagnosis it is appropriate in patients with clinically suspected deep-vein thrombosis to apply an objective test before starting anticoagulant treatment. Impedance plethysmography is a highly accurate technique for the detection of proximal-vein thrombosis with a reported sensitivity and specificity of 93 and 97%, respectively. In all previous reported evaluations of impedance plethysmography an apparatus which was developed in 1971 was used. A new computerized impedance plethysmography, using a novel device to measure impedance, was blindly compared against venography in 443 consecutive outpatients with clinically suspected deep-vein thrombosis. In the first phase of the study the computerized impedance plethysmography test results of 242 symptomatic patients were used to develop a discriminant line. Subsequently, this discriminant line was validated in the second phase of the study in another 201 symptomatic patients. The combined sensitivity and specificity of these two phases for proximal-vein thrombosis was 91% [95% confidence interval (CI), 86 to 94%] and 94% and (95% CI, 90 to 96%), respectively, which compares favourably with impedance plethysmography. It is concluded that computerized impedance plethysmography is a simple, portable, non-invasive technique with a high accuracy for the detection of proximal vein thrombosis. However, before computerized impedance plethysmography can be used as the only test in the diagnosis of deep-vein thrombosis, the safety of withholding anticoagulant treatment to patients with repeated normal computerized test results should be assessed during long-term follow-up studies.

Adolescent↗
PubMed1991

Failure of computerized impedance plethysmography in the diagnostic management of patients with clinically suspected deep-vein thrombosis.

Before a new diagnostic modality can be introduced in clinical medicine, the validity of both a normal and abnormal test result have to be assessed prospectively in an appropriate patient group. We have evaluated the clinical validity of a new computerized impedance plethysmography (CIP) in the diagnostic management of 381 consecutive patients with clinically suspected venous thrombosis. In patients with serially normal CIP results, the diagnosis of venous thrombosis was refuted and, consequently, they were not treated with anticoagulant therapy and all were followed up for a period of 6 months to estimate the occurrence of symptomatic venous thromboembolism. The study was prematurely terminated by the safety monitoring committee because of an unacceptably high incidence of confirmed venous thromboembolism (10 patients, 3.2%; 95% confidence interval: 1.6% to 6%), including 4 episodes of fatal pulmonary embolism. In a subsequent explanatory study using ultrasonography in 29 other symptomatic patients who had at least 2 repeated normal CIP test results, the failure of CIP to detect proximal vein thrombosis was confirmed in 4 patients (14%). The reasons for this failure are probably related to the use of a modified device to measure impedance in the CIP apparatus, resulting in a lower ability to separate patients without venous thrombosis from those with the disease. We concluded that CIP is insensitive for the detection of proximal vein thrombosis and, therefore, not clinically useful in the diagnostic management of patients with suspected venous thrombosis.

Adolescent↗
PubMed1991

An MMPI evaluation of male sexual dysfunction.

The present study concerned the evaluation of personality traits associated with sexual dysfunctions. The MMPI was used as a psychodiagnostic tool in male subjects (N = 37) with erectile disorder or premature ejaculation. The results tend to support some clinical observations based upon the cognitive-behavioral approach and some neurophysiological data.

Adaptation, Psychological↗
PubMed1991

[Splenic metastases of pulmonary carcinoma. Apropos of a clinical case].

A case of single splenic metastasis from large cell anaplastic carcinoma of the lung is described. The patient first underwent pulmonary lobectomy and then splenectomy. He is still alive 42 months after the first operation and 41 after the second. The case herein described is rather uncommon, due to the rarity of single splenic metastases, and the long survival of the patient. The latter point strongly suggests an aggressive surgical approach to single metastases, even if primary tumor has extremely poor prognosis.

Carcinoma, Non-Small-Cell Lung↗
PubMed1989

[Dermoid cysts of the floor of mouth].

After brief mention of the embryogenesis of oral organs, a case of congenital dermoid cyst of the floor of the mouth treated surgically intraorally is reported. A short discussion on differential diagnosis follows.

Adult↗
PubMed1988

Sino-atrial dissociation: evidence by intracardiac recordings in man and by microelectrode studies on isolated rabbit atrium.

The electrophysiologic mechanisms of sinus dysfunction have recently been determined by direct recordings of the sinus node electrogram. The association of various degrees of abnormalities in the formation of the impulse within the sinus node and of sinoatrial conduction block, represents the pathophysiological substrate of the mechanism of sinus node dysfunction. The purpose of this work is to present clinical and experimental data supporting the concept of sinus node isolation. In our clinical case, the sinus node was probably intact despite aspects of sinus node dysfunction on the surface ECG. Sinus node electrograms were recorded with a sinoatrial conduction time of 100 ms (normal values in our laboratory: 83 ms +/- 38 ms). Atrial mapping demonstrated that the area depolarized by the sinus node involved a 2 cm2 zone surrounding it. This perisinusal activity could not be recorded on the surface ECG. Both exit and entry blocks in the sinus node were demonstrated. Our experimental data showed a total desynchronization between the electrical activity of the sinus node and that of the atrium under hypoxic conditions. Both types of cases demonstrated that an atrial dysrhythmia was coexisting with regular sinus activity. From these data we concluded that a sinus node free from any pathological involvement could be associated with severe symptoms of sinus node dysfunction on the surface ECG.

Animals↗
PubMed1987

Pulmonary artery obstruction due to giant cell arteritis.

Giant cell arteritis is often referred to in the context of polymyalgia rheumatica with temporal artery involvement. There are, however, more malignant forms of presentation of this necrotizing arteritis involving either the great vessels of the aorta or, occasionally, the pulmonary arteries. Our case relates to giant cell arteritis presenting as pulmonary artery obstruction in a patient without polymyalgia rheumatica or extensive aortic or proximal great vessel involvement.

Aged↗
PubMed1984

Stereomorphological arrangement of capillaries in skeletal muscle in normal and stenosed young and adult rats.

The stereomorphological arrangement of skeletal muscle capillaries depends on many factors. Genetic biochemical composition of muscle fibers, age, and training can interfere with the growth of the capillary network. This study is focused on the age effect of chronic reduction of blood flow, as in arterial stenosis, in skeletal muscle network of young rats when compared with adult rats. It has been observed that there is a statistically significant decrease of the length of short capillaries which cross the muscle fibers. In adult rats the opposite occurs.

Age Factors↗