Biomedical subjects
D Fontana
Publications and source records attributed to D Fontana.
Conditioned sensitization to the psychomotor stimulant cocaine.
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Monoclonal antibody Ki-67 in the study of the proliferative activity of bladder carcinoma.
We studied the proliferative activity of bladder carcinoma using monoclonal antibody Ki-67, which is able to stain a nuclear antigen exclusively present in cells in the cell cycle, that is with activated deoxyribonucleic acid (DNA). We used this immunohistochemical technique on neoplastic tissue removed by transurethral resection from 101 patients. A significant correlation was observed (p less than 0.003) between cells with activated DNA and histological grading, even though within the context of each grade we observed tumors with a different proliferation index. Furthermore, we studied the location of the activated cells in the context of the tumor. In invasive tumors (stages T1 to T4) cells with activated DNA were always present at the base of implant of the tumor and in the neoplastic tissue that infiltrates the bladder wall. In regard to noninvasive tumors (stage Ta), in 57% of the cases most cells with activated DNA were present in the vegetative portion of the tumor and there were no recurrences at followup, while in 43% of the cases such cells were present also or especially at the base of implant of the tumor, near the lamina propria. In the latter patients we observed a 94% recurrence rate. These results suggest that the immunohistochemical assessment of the proliferative activity of transitional tumors of the bladder, using monoclonal antibody Ki-67, and the evaluation of the location of stained neoplastic cells provide a more reliable estimate of biological aggressiveness than that obtained with histopathological patterns alone.
Conditioned components of cocaine sensitization.
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[Intestinal malrotations in the adult].
The paper reports a case of intestinal malrotation in an adult patient with an anomalous location in the left hypochondrium of the cecum and vermiform appendix. The patient underwent explorative laparotomy for peritonitis due to acute appendicitis. Following a review of the literature, the anomaly was classified in embryological terms as a union defect during the third developmental stage of the umbilical loop. Attention is focused on the importance of an exact knowledge of the embryology of intestinal rotation in order to avoid technical surgical errors. In conclusion, the value of giving the patient precise iconographic documents is stressed in order to inform the surgeon who may have to operate on the patient's abdomen in the future.
[Drugs, impotence and infertility].
The Authors report the results of a study on 87 patients; among them some were drug dependent and others were already drug-free. This study has in object the consequences of some drugs use (psycoanaleptics, psycoleptics, psychodysleptics) in the sexual behavior and male fertility. Abuse of these drugs seems to be able to cause impotence by psychologic and organic factors. As it concerns the drugs effects on male fertility, we have observed O.T.A. during the dependence period, that seems to be reversible after detoxification. Our purpose is to further investigate the andrological aspects of drug dependence.
[Reliability of transrectal echography in the early diagnosis of prostatic carcinoma: our experience].
The Authors observed a group of 20 patients, each of them suffering from prostatic carcinoma clinically localized in only one lobe. All patients were investigated by trans-rectal US tomography, performed with a 5 MHz linear sound, and by prostatic biopsy in both lobes. The Authors evaluate US tomography results in comparison with biopsy executed on the apparently normal lobe and appreciable sensibility, specificity and predictive capability of this method. The Authors believe that trans-rectal US tomography, after having considered sensitivity and specificity values is not to propose as a screening method for early diagnosis of prostatic carcinoma.
[The treatment of priapism].
Priapism, that is a long lasting erection in absence of sexual desire and is sometimes painful, has represented a rare occurrence until few years ago; such occurrence has become much frequent since pharmaco-erection have been used. There are still many doubts about the etiopathogenesis of priapism, that anyway happens because of a long lasting pathological discrepancy between arterious flux to penis corpora cavernosa and venous down flowing. For to establish how and when we must treat priapism, it is very important to know the causes of it, so that we can use the more properly therapy for each case. It's possible to classify the therapies in the following ways: a) extracavernosa, b) located in the corpus cavernosum. These last ones are most used and include the punction and the drainage of the blood of the cavernous body and sometime the "shunt" spongio-cavernosum. The treatment must be effected without loss of time in those rare cases of spontaneous priapism. Indeed, according to our experience, it's not necessary to be extremely supporting for intervention for priapism post pharmaco-erection. In fact the wait of 8-10 hours reduces the number of invasive treatments, without danger for the integrity of cavernous tissue.
[Coagulation and fibrinolytic activity of blood from the corpus cavernosum].
Thrombosis in cavernous bodies during erection-induced blood stasis is a exceptional phenomenon. This observation, induced the Authors to study coagulative and fibrinolytic activities of blood in cavernous bodies during pharmacologically induced erection. The results of the tests performed show that the blood of cavernous bodies has a fibrinolytic activity 3 times higher than peripheral blood (FPLA = 277 +- 83 mm2) and did not decrease when plasma was incubated with anti t-PA. During middle length erections, this activity is not expressed and the absence of thrombi formation seems to be due to a slowing of blood coagulation processes. On the other hand, during long-lasting erections, fibrinolysis is induced resulting in a local consumption like coagulopathy. Fibrinolysis in this district is not related to high t-PA plasma levels.
[Lipoma of the large intestine].
A case of lipoma of the colon with a clinical picture of intestinal occlusion due to colo-colic invagination is reported. The invagination diagnosis was arrived at preoperatively by opaque clysis and echography. Surgical treatment consisted of segmentary resection owing to trouble in the affected ansa.
Factors that influence peak bone mass formation: a study of calcium balance and the inheritance of bone mass in adolescent females.
We suggested that calcium may be an important determinant of peak bone mass. For further elucidation, calcium balances in adolescent females with different calcium intakes (270-1637 mg/d), and a 2-y intervention study of calcium supplementation were performed. Hereditary influences on bone status were also evaluated by comparing subjects' and parents' bone mass. The main determinant of calcium balance was calcium intake; net calcium absorption increased with intake and urinary calcium did not change. Adolescent females retained 200-500 mg Ca/d, suggesting that inadequate calcium intake may translate into inadequate calcium retention and a reduction in peak bone mass. There was a more pronounced increase in bone mass over time in the calcium-supplemented group (1640 mg Ca/d) than in the control group (750 mg Ca/d), but the differences between bone mass measurements were not statistically significant, possibly because of a type II error. By the age of 16 y daughters had accumulated 90-97% of the bone mass of their premenopausal mothers.
[Indications for correction of varicocele].
In this paper are indicated the procedures to correct the varicocele, based on both the experience of the Authors and the data from the literature. In prepubertal subjects only varicoceles of II and III grade should be operated, meanwhile the I grade can be followed up because it can improve spontaneously. In young people, the asymptomatic varicocele diagnosed incidentally, for instance when people are controlled for military duty, should be operated in order to avoid possible dyspermic troubles. Infertile Adults with varicocele should be always surgically treated but which have either contemporary elevated serum FSH values or different untreated infertility causes. The age limits between which a varicocele can be successfully treated, in order to improve the infertility, are not yet precisely identified. Patients over 35 years are unlikely to recover fertility after operation.
Lipoprotein, apolipoprotein, and lipolytic enzyme changes following estrogen administration in postmenopausal women.
To test whether estrogen can modulate the cholesterolemic response to an Occidental diet, six healthy postmenopausal women were studied for 84 days while ingesting a solid food diet of constant composition high in cholesterol content (995 mg/d). In the middle of the study, estrogen (17 alpha-ethinyl estradiol, 1 microgram/kg per day) was administered orally. Ingestion of the diet for the initial 28 days did not alter lipoprotein lipid or apolipoprotein (apo) levels. However, with just 4 days of estrogen use there were significant decreases in apoE (-36%), low density lipoprotein cholesterol (-26%), and postheparin plasma hepatic triglyceride lipase activity (HTGL) (-61%), and an increase in high density lipoprotein (HDL) triglyceride (72%). These changes persisted throughout the estrogen use. The percent change in HTGL with 4 days of estrogen correlated inversely with the percent change in HDL triglyceride (rs = -0.94). After 28 days of estrogen there were also significant increases in HDL cholesterol (21%), HDL2 cholesterol (42%), apoA-I (37%), and apoA-II (9%), and a decrease in apoB (-11%). The level of apoE at this juncture correlated inversely with the level of HDL cholesterol (rs = -0.90), and the levels of HTGL and apoA-I correlated with HDL2 cholesterol (rs = -0.89 and rs = 0.89, respectively). Thus, HTGL may play a role in both the early estrogen-related changes in HDL triglyceride and apoE and the late estrogen-related changes in HDL cholesterol, apoA-I, and apoA-II.
[Total parenteral nutrition in pediatric surgery. Considerations on the calculation of requirements and possibility of using computer-assisted methods].
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Transmembrane signaling in Dictyostelium.
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Results of long term treatment of advanced prostatic cancer with the LHRH analogue buserelin.
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[Use of the monoclonal antibody KI-67 in the study of the proliferative activity of urologic tumors. Preliminary data].
The authors report the preliminary data of a study on the proliferative activity in urologic cancers. They use the monoclonal antibody KI-67 which can find out a nuclear antigen present only in cells in proliferative phase. They describe the methodology and report the results concerning 12 cancers of the kidney, 17 of the bladder, 17 of the prostate and 2 of the testicle. The most interesting results were obtained in the study of bladder cancer where they could pick out, in the context of the cancers with grading G2, a sub-group with proliferative characteristics similar to those of cancers G3 and vice-versa. They also obtained important results in the study of prostate cancer in hormonal therapy, as they could demonstrate the disappearance of the proliferative activity in patients responding clinically to the treatment.
Cell-cell interactions in the development of Dictyostelium.
We have described in D. discoideum a highly organized cell aggregation that is mediated by cAMP. After suitable differentiation induced by starvation, the cells develop the capacity to orient in gradients of cAMP and to secrete cAMP in response to cAMP. This signaling response sets up the cell-cell relay of cAMP waves that transiently orients the cells toward the center. Both the signaling response and the chemotactic response, measured in isolated cells, adapt. The kinetics and properties of adaptation of the two responses are similar and may be due to the same mechanism. The mechanism does not involve protein synthesis, a change in the number or affinity of surface receptors, or the activation of adenylate cyclase. Adaptation of signaling is essential for the oscillatory production of cAMP at the aggregation centers and ensures that the cAMP waves move steadily toward the edge of the aggregation territories. Adaptation of the chemotactic response also ensures that cells do not reorient away from the center in the gradient presented by the trailing edge of the wave. We have demonstrated that both chemotaxis and cAMP signaling are mediated by the same surface receptor. The polypeptide containing the binding site of the receptor has been identified by photoaffinity labeling with [32P]-8-N3-cAMP as a diffuse band of 41,000-45,000 Mr. The receptor and adenylate cyclase copurify on a homogeneous class of vesicles resistant to extraction by nonionic detergents. A GTP-binding protein that is a substrate for cholera toxin-catalyzed ADP ribosylation is found in supernatants and membranes and may be similar to the Gs regulatory protein of adenylate cyclase in higher organisms. The mechanism of activation of the adenylate cyclase and chemotactic machinery is unknown. We have been able to inhibit the activation of the adenylate cyclase selectively and rapidly with agents acting to crosslink cell surface components, which may give a clue to the activation mechanism. The elaborate mechanisms of cell-cell communication occurring in D. discoideum are without precedent in biological literature, although models of oscillatory wave propagation have been proposed to account for pattern formation. Although it is unlikely that extracellular cAMP would be involved, it is not inconceivable that such mechanisms occur during the development of more evolutionarily advanced organisms. The organized communication system in D. discoideum is only apparent when cells are plated uniformly on a flat surface; such organized movements occurring in a three-dimensional structure such as an embryo would be very difficult to discern.