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Biomedical subjects

A Cavallo

Publications and source records attributed to A Cavallo.

At least 55 records · Page 3Linked to original sources
PubMed1994

Disappearance curves of tumor markers after radical surgery.

CEA serum levels were sampled from 15 patients with lung carcinoma, 12 patients with colon carcinoma, and 5 patients with gastric carcinoma before and after radical excision of the malignancy. In addition, TPA serum levels were measured in 7 patients with lung carcinoma and CA 19.9 serum levels in 9 patients with colon carcinoma, before and after curative surgery. Irrespective of the primary malignancy, a CEA half-life of approximately 3 days was calculated. The normalization time was related to the preoperative level of the marker, being longer when the preoperative CEA level was > 20 ng/ml. The TPA half-life was slightly longer than 1 day, ranging from less than 1 day to more than 3 days, with a normalization time of about 20 days. The CA 19.9 half-life was slightly longer than 1 day with variations from less than 1 day to about 3 days. Many factors, especially associated inflammatory processes and hepatic clearance imbalances, may influence marker kinetics in the postoperative period. A correct evaluation of the clinical significance of tumor marker half-life after radical surgery will require a larger number of patients as well as careful and prolonged follow-up.

Adenocarcinoma↗
PubMed1994

[Benign fibrous mesothelioma of the pleura].

The authors report 4 cases of patients with benign fibrous mesothelioma of the pleura, an extremely rare pathology (not more than 500 cases reported to date in the literature), and discuss biological behaviour, diagnosis and surgical treatment. Benign fibrous mesothelioma is generally diagnosed by chance during chest x-ray given that it is paucisymptomatic; diagnostic procedures include thoracic CT (which may be supplemented by transthoracic needle biopsy) and bronchoscopy. Treatment is surgical and consists of exeresis of the neoplasia; prognosis is excellent and cases are reported in the literature of 24-year follow-up without recurrence. Lastly, the authors underline the importance of modern immunohistochemical techniques which help the surgeon to formulate a precise diagnosis and to differentiate benign fibrous mesothelioma.

Adult↗
PubMed1994

Successful management of hemorrhage from the pulmonary artery stump after lobectomy for bronchogenic carcinoma.

Pulmonary bleeding from the arterial stump following lung resection is a life-threatening complication requiring immediate surgical correction. Predisposing conditions are almost always represented by bronchopleural fistula and empyema. The operation often represents a major challenge to the thoracic surgeon, because of the choice of the most appropriate surgical access, the optimal technique to control the bleeding, as well as to treat the associated bronchopleural fistula. We present a case of successful treatment of hemorrhage from the pulmonary artery stump associated with BPF and empyema following lobectomy for bronchogenic carcinoma. A standard postero-lateral thoracotomy using the previous incision was used with adequate exposure of the source of bleeding and the bronchopleural fistula.

Aged↗
PubMed1994

[Doppler color-echo and flowmetric evaluations in ovarian tumors in postmenopausal patients].

The use of color Doppler techniques in transvaginal sonography (US) permitted the identification of some typical flowmetric patterns of malignant ovarian cancers, because of such characteristics of neoplastic vessels as no media in the vessel wall, the presence of A-V shunts, and so on. These features reduce vascular impedance, from which low pulsatility index and resistance index values result. Eighty-one patients with ovarian masses were examined: in 19 of them histopathology revealed malignant lesions in different stages. Eighteen of those lesions exhibited suspect transvaginal patterns; in one case only the US patterns suggested a benign lesion, which was a serous cystadenocarcinoma with thin and regular septa. In all the malignant lesions flow could be sampled in six sites at least; the lowest pulsatility index values, obtained by multiple samplings in the same lesion, were considered as the most representative of the histologic features of the lesion. The average of the lowest pulsatility index values in 18 of 19 malignant lesions was 0.75. In one case only (the only false negative in the series) the lowest pulsatility index value was 1.20. Doppler signals were detected in 58 of 62 benign lesions only and the average of the lowest pulsatility index values was 1.80. The only kind of condition with low pulsatility index was the inflammatory disease (all the 6 sampled cases). If we consider a pulsatility index < 1 as the cut-off value for malignant lesions, the sensitivity and the specificity of color Doppler US were 95% and 91%, respectively, in our series. The positive predictive value of the exam was 75% and its negative predictive value was 95%.

Color↗
PubMed1993

[Post-traumatic hernia of the diaphragm].

The paper reports the series of post-traumatic hernias of the diaphragm observed during the period between 1954 and June 1992. This group of 77 patients (59 males and 18 females) were aged between 6 and 75 years old. Both acute and chronic hernias were reported; in 60 cases the diaphragmatic lesion was on the left, in 9 cases on the right, and there were 8 cases of laceration to both hemidiaphragms. The most frequently herniated organ was the stomach, followed by the transverse colon and spleen. With regard to the access route used, the authors draw attention to the fact that during the first twenty years of the series thoracotomies were prevalently used, whereas during the last decade laparotomy has been used in cases of early post-traumatic hernia, thoracotomy in cases of chronic post-traumatic hernia or if there is suspected damage to organs and intrathoracic structures.

Adolescent↗
PubMed1993

The pineal gland in human beings: relevance to pediatrics.

Several facts suggest that the pineal gland must have a significant role in human beings: the presence of melatonin secretion from infancy to old age; a circadian secretory pattern similar to that found in animal species in which this gland has well-defined functions; its responsiveness to light; and the presence of melatonin receptors in the hypothalamus. Despite the importance of the pineal gland and melatonin in the reproductive activity of all nonprimate vertebrate species studied, the relationship of melatonin secretion to the activity of the hypothalamic-pituitary-gonadal axis in human beings remains presumptive. Some data suggest a possible pineal-reproductive connection throughout the human lifespan, but new research approaches are needed for a better definition of this connection during normal development and in disorders of the reproductive axis. In addition, recent studies that have applied strictly defined techniques to unravel the masking effects of various behavioral and environmental factors suggest that the pineal gland and melatonin have a fundamental role in the regulation of the human biologic clock. Melatonin concentrations in blood or urine may become a useful marker of the circadian rhythm in disorders of rhythms. Moreover, administration of melatonin in physiologic or pharmacologic doses may have an important application in suppression of the hypothalamic-pituitary-gonadal axis as a contraceptive, and in therapy for disorders of biologic rhythms. Among the latter, of particular interest to the pediatric population will be the potential application of melatonin treatment in establishing or reestablishing circadian rhythms in infants and children maintained for long periods under artificial light conditions, as encountered in intensive care units, and in the treatment of sleep and other rhythm disorders associated with developmental delay or blindness. Further research and approval by the U.S. Food and Drug Administration will be required before these applications will be available to the practicing pediatrician. The identification of melatonin receptors in the human hypothalamic fetal and adult tissues and the development of potent melatonin agonists and antagonists have paved the way for new research approaches that are needed to further investigate this intriguing, long-forgotten gland in human beings.

Humans↗
PubMed1993

Melatonin and human puberty: current perspectives.

Many studies of melatonin in human puberty are difficult to interpret in light of methodological considerations such as the use of single blood samples collected either during the day or at night; a small number of observations; the failure to include the temporal characteristics of melatonin secretion; the definition of puberty by the use of broad clinical features without use of hormonal markers of puberty; the lack of control for the actual duration and intensity of light exposure during the days preceding the study; and the cross sectional nature of most studies. The few studies that have examined the plasma melatonin rhythm in humans by multiple blood sampling overnight or over 24 hr suggest that normal pubertal development (as well as normal ovarian function) are not linked to alterations in the plasma melatonin profile. There is, however, some evidence to suggest that disorders of the hypothalamic-pituitary-gonadal axis (delayed puberty, precocious puberty, hypothalamic amenorrhea) may be linked to altered plasma melatonin profile, at least in some cases. These findings, taken together with strong evidence for the role of the pineal gland in the reproductive function of other vertebrate species, render unlikely the inference that the pineal gland has no role in the development and function of the human reproductive axis. Thus, one may speculate that a pineal-puberty relation does exist in humans and that the research techniques applied to date have been inadequate to uncover this relation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Melatonin secretion during adrenarche in normal human puberty and in pubertal disorders.

The relation between human melatonin secretion and adrenarche was investigated in 113 subjects ages 5.5-17 years. Melatonin nocturnal profile was determined obtaining hourly blood samples from 2000 to 0800 and DHEA-S was measured in pooled plasma of these samples. In 62 normal subjects, melatonin peak by stages of adrenarche was 152.5 +/- 65.4, 125.9 +/- 59.4, and 115.2 +/- 40.7 pg/ml for stages 1, 2, and 3-5, respectively, and the linear trend components were significant; no significant relation remained after partialling the variance associated with age and pubertal stages. In 41 subjects with disorders of pubertal onset, mean melatonin peak by stages of adrenarche was 149.0 +/- 54.4, 194.0 +/- 34.2, and 129.8 +/- 52.2 pg/ml for stages 1, 2, and 3-5, respectively, and the linear trend components were not significant. In seven prepubertal girls with precocious adrenarche, melatonin peak was not significantly different from values in seven normal prepubertal, preadrenarchal girls. The relation between time of melatonin peak and adrenarche was not significant in any of the diagnostic groups. The linear correlation between melatonin peak and DHEA-S was not significant in either adrenarche stage 1 (r = -0.19, n = 41) or stages 3-5 (r = -0.13, n = 23). The results do not support a role for adrenarche in the pineal-puberty relation in humans.

Adolescent↗
PubMed1992

Plasma melatonin rhythm in normal puberty: interactions of age and pubertal stages.

Studies on the relation between the pineal and human puberty have yielded conflicting results, partly due to methodologic issues, such as failure to consider the characteristic secretory rhythm of melatonin, or exclusion of normal subjects. Melatonin nocturnal rhythm was assessed in 62 normal subjects (ages 5-17 years), in whom hourly blood samples were collected by constant withdrawal from 18.00 to 08.00 h. Melatonin peak and mean integrated nocturnal concentrations were highly correlated (r = 0.90, p less than 0.05) and data are shown for melatonin peak. Tanner criteria were applied for pubertal stages. Mean melatonin peak was 153.6 +/- 72.6 pg/ml for stage 1, 141.0 +/- 26.2 pg/ml for stage 2, and 116.6 +/- 43.6 pg/ml for stages 3-5. There was a significant linear trend for decreasing melatonin peak with puberty. The subjects were also grouped into discrete age groups (5-6.99 years through 15-17 years); a significant linear trend was present for decreasing melatonin peak with age. The correlation between melatonin peak and age for all cases was r = -0.29, p less than 0.05. Analysis of covariance for melatonin peak among the pubertal groups showed no relation of melatonin and puberty when age was covaried. The time of peak was not significantly different among the pubertal groups or the age groups, despite a significant linear trend for later bedtime with age. The duration of the nocturnal surge was not significantly different among the pubertal groups. The data suggest that an overlapping effect of age may mask an interaction between the pineal and normal human puberty.

Adolescent↗
PubMed1992

Relation between nocturnal melatonin profile and hormonal markers of puberty in humans.

We examined the relation between nocturnal melatonin and hormonal markers of puberty in 57 normal children and adolescents and 39 subjects with disorders of pubertal onset. Melatonin was measured in hourly blood samples drawn overnight by constant withdrawal. Basal 08.00 h plasma testosterone, estradiol and LH, and the peak LH response to LHRH administration were determined. There were no significant correlations between testosterone, estradiol, basal LH and peak LH and melatonin peak (r = -0.18, -0.22, -0.02, -0.12, respectively) or melatonin peak time (r = 0.12, -0.01, -0.02, 0.07 respectively). The results were not affected significantly by sex, diagnosis or age. A comparison of subjects grouped by peak LH < 15 U/l (most likely prepubertal; n = 40) and peak LH > 30 U/l (most likely pubertal; n = 34) showed no significant differences in melatonin peak (160.5 +/- 59.3 vs. 146.6 +/- 50.9 pg/ml; t = 1.09; p > 0.05) or melatonin peak time (1.8 +/- 1.7 vs. 2.5 +/- 1.7 h; t = -1.79; p > 0.05). Although a pineal-puberty relation cannot be excluded, the results do not support the hypothesis that melatonin restrains the hypothalamic-pituitary-gonadal axis during childhood.

Adolescent↗
PubMed1991

Thymoma: results of 241 operated cases.

Clinical and histopathological aspects of 241 thymomas were reviewed. One hundred sixty of the patients with thymoma had myasthenia gravis and 15 had other autoimmune diseases; 55% of the thymomas were encapsulated and 45% invasive. Operation was radical resection in 87.5% of the patients, subtotal resection with residual tumor in 8.7%, and simple biopsy in 3.7%. A tumor relapse was observed in 24 patients (10%): 2 (1.5%) of 133 with encapsulated thymomas and 22 (20.4%) of 108 with invasive thymomas; among these patients, a relapse was found in 20.6% of the patients who received radiotherapy postoperatively and in 24.6% who did not. Adverse prognostic factors were clinical stage IVa (multiple pleural nodes), not feasible resection (for technical reasons), inoperable tumor relapse, and association with one of the following autoimmune diseases: pure red cell aplasia, hypogammaglobulinemia, and lupus erythematosus. Conversely, myasthenia gravis is now a curable disease; it contributes to early discovery of associated thymoma, thus allowing a better survival for patients with thymoma who have myasthenia gravis compared with patients with thymoma but without myasthenia gravis (p less than 0.05). Postoperative radiotherapy does not seem necessary after removal of encapsulated thymomas, but it is advisable in case of invasive thymomas, regardless of the extent of the resection.

Adolescent↗
PubMed1991

Interactions of sleep and clonidine on daytime prolactin secretion in humans.

The suppressive roles of adrenergic stimulation and rapid eye movement (REM) sleep on human prolactin (PRL) secretion are controversial. We examined the effects of sleep, clonidine (an alpha 2-adrenergic agonist), and their interaction on PRL secretion. Two groups of normal men (nine each) were studied in two morning sessions. Each group received either placebo or clonidine in both sessions. Subjects remained awake in the first session and in the next session they were asked to sleep for 3 h after the test dose was given. Blood samples were drawn at 30-min intervals and polysomnographic recordings were obtained at each session. PRL concentrations remained at baseline and no clonidine effect was detected while awake. PRL concentrations increased in placebo and clonidine groups during sleep. Despite significant suppression of REM sleep in the clonidine group, no differences were detected between the placebo and clonidine groups in peak PRL or mean PRL concentrations during the study. Also, no significant difference was detected in comparing PRL responses during non-REM sleep in both groups. The results suggest that alpha 2-adrenergic stimulation does not have a significant role in modulating human PRL secretion during sleep.

Adolescent↗