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Biomedical subjects

S Rossi

Publications and source records attributed to S Rossi.

At least 307 records · Page 17Linked to original sources

Receptors for epidermal growth factor and steroid hormones in human breast cancer.

Epidermal growth factor (EGF) seems to play an important role in regulating the proliferation of human breast cancer. Fifty-five primary breast tumors and 7 lymph node metastases were simultaneously assayed for the presence of EGF receptors (EGFR), estrogen receptors (ER), and progesterone receptors (PR). Overall, 42% (23/55) of the tumors were EGFR positive. EGFR were more frequently present in ER- and PR-negative than in ER- and PR-positive tumors. In particular, a negative correlation between EGFR and PR (chi 2 = 6.8; p greater than 0.01) was observed. All metastatic tumors were EGFR negative, and in all cases but 1 the levels of EGFR were higher in metastatic than in primary tumors. Our results suggest the presence of a subclass of breast tumors, the growth of which is primarily regulated by EGF or EGF-like substances rather than by steroid hormones. In this group, not amenable to endocrine therapy, EGF receptors should represent a target for therapeutic intervention.

Breast Neoplasms↗

Induction of malignant subcutaneous sarcomas in hamsters by a recombinant DNA containing BK virus early region and the activated human c-Harvey-ras oncogene.

Malignant undifferentiated sarcomas were induced in 11 of 15 (73.3%) newborn Syrian hamsters by s.c. inoculation of a recombinant DNA (pBK/c-rasA) containing BK virus (BKV) early region gene and the activated human c-Harvey-ras(c-Ha-ras) oncogene derived from T24 bladder carcinoma. The two genes inoculated independently as well as a recombinant DNA of BKV early region gene and normal human c-Ha-ras proto-oncogene were not tumorigenic. Tumor-derived cell lines propagated in culture were immortalized and had growth characteristics consistent with a fully transformed phenotype. Tumors and tumor cell lines showed tandem insertions of pBK/c-rasA in high copy number and expressed BKV- and c-Ha-ras-specific transcripts as well as BKV T-antigen and c-Ha-ras protein with a molecular weight of 21,000. We conclude that BKV DNA requires interaction with other oncogenic functions for tumorigenicity. These findings may be relevant to the role of BKV in human neoplasia, where cooperation or synergism between BKV and cellular oncogenes could occur as an aspect of the multifactorial process of carcinogenesis.

Animals↗

Temperature gradients and prebiological evolution.

Thermodiffusive transport of trace elements that play important roles in living organisms, such as molybdenum, nickel, copper, and vanadium, was studied in a nonisothermal biphasic system comprised of a liquid solution and jelly layers. Our intent was to mimic the effects of temperature gradients on prebiological evolution. Conditions were found, similar to those probably existing during development of early eobionts, under which all the elements tested were concentrated within the heated jelly. Nonisothermal matter transport through grossly porous artificial membranes--the process of thermodialysis--was next investigated to assess the behavior of compartmentalized, i.e., membrane bound, eobionts. Particular interest was dedicated to the continuity of nonisothermal transport phenomena in the homogeneous and heterogeneous (membrane) systems and to the ability of compartmentalized eobionts to withstand osmotic swelling by means of thermoosmotic transport. Interestingly enough, under the experimental conditions adopted, sodium/potassium countertransport is also found, suggesting a very early physicochemical origin of the sodium-potassium pump. Surprisingly enough, evidence of teleonomic behavior appears in those very simple analogs of prebiological systems.

Biological Evolution↗

High-dose folinic acid (HDFA) combined with 5-fluorouracil (5-FU) in first line chemotherapy of advanced large bowel cancer.

The therapeutic activity of 5-FU in large bowel cancer is enhanced by increasing the intracellular pool of reduced folates. We treated 45 patients with advanced colon cancer with HDFA and 5-FU for 5 consecutive days. None had been given previous radio- or chemotherapy. All had measurable disease. Not one complete response was observed. Thirteen of the 39 evaluable patients showed partial response. Median duration of response was 9+ months. The probability of 50% survival was 15 months for all evaluable patients. There was no case of severe toxicity and the principal toxic effects were oral mucositis and diarrhea. To date, HDFA + 5-FU is one of the most effective treatments for large bowel cancer.

Adult↗

Cholesteryl octanoate breath test. Preliminary studies on a new noninvasive test of human pancreatic exocrine function.

A new breath test for noninvasive assessment of pancreatic exocrine function in humans was developed. The test is based on the hydrolysis of cholesteryl-[1-14C]octanoate by pancreatic carboxyl ester lipase (cholesterol esterase) with subsequent absorption and hepatic metabolism of the liberated octanoate to 14CO2. The rate at which 14CO2 appears in breath appeared to be proportional to the rate of hydrolysis. The substrate is administered as a gum acacia stabilized emulsion of vegetable oil (18 g) containing cholesteryl octanoate (2 g; 4.4 microCi) dispersed in a 500-ml isotonic meal. Tests were performed in 6 healthy volunteers and 11 patients with pancreatic disease with varying degrees of steatorrhea. In healthy subjects, 14CO2 output was rapid with peak output occurring at 60-90 min in all subjects; cumulative output in 4 h averaged 30%. Duplicate studies indicated that the time-course of 14CO2 recovery was reproducible. The pattern of 14CO2 output in patients with pancreatic disease varied widely. Patients without steatorrhea (fecal fat less than or equal to 7 g/day) or with mild steatorrhea (fecal fat 7-11 g/day) had normal or near normal patterns of 14CO2 output, whereas patients with moderate or severe steatorrhea (fecal fat greater than 11 g/day) expired 14CO2 at a rate one-third to one-tenth that of the healthy volunteers. Addition of pancreatic enzyme supplementation to the test meal increased 14CO2 output in 6 of 6 patients with moderate or severe steatorrhea, suggesting that the activity of pancreatic carboxyl ester lipase was rate limiting in these patients. In an additional study in a healthy volunteer, 14CO2 and 13CO2 were measured simultaneously in breath after ingestion of a test meal containing cholesteryl-[1-13C]octanoate and 14C-octanoate. 14CO2 was expired more rapidly than 13CO2, suggesting that hydrolysis of the substrate may also be rate limiting in healthy volunteers. These studies indicate that severe pancreatic exocrine dysfunction can be detected with a simple breath test in 60-90 min.

Adult↗

[Compounds with anti-gastric secretion and antiulcer activity. V. Derivatives of 3,3,4a,6,7,11b-hexahydro-2H,5H-benzo [1,4]cyclohep[1,2-b][1,4]-oxazine and related products].

A series of hexahydrobenzo[3,4]cyclohept[1,2-b][1,4]oxazines, with different substituents at the benzene and oxazine rings and nitrogen atom, was synthetized. The diastereomers and enantiomers of the unsubstituted compound and the related derivatives hexahydrobenzo[5,6] and exahydrobenzo[6,7]cyclohept[1,2-b][1,4]oxazine, hexahydro[1]benzoxepine and hexahydro[1]benzothiepin[5,4-b][1,4]oxazine, octahydrobenzo[3,4]cyclohept[1,2-b][1,4]diazine were also prepared. Some of these compounds inhibited at low doses gastric secretion in pylorus-ligated rats and antagonized ulcers in pylorus-ligated rats plus acetylsalicylic acid and in cold+restraint-stressed rats. When the most active compounds were tested on cats with Heidenhain pouch, they induced unwanted side effects that ruled out further development of these chemical series.

Animals↗

Ultrasonically guided fine-needle biopsy: a new useful technique in pathological staging of malignant lymphoma.

Ultrasonically guided fine-needle aspiration biopsy of abdominal focal lesions was performed on 15 patients with non-Hodgkin's lymphoma, in 14 cases for pathological staging, in 1 case for differential diagnosis between lymphoma recurrence and other malignancy. The biopsy was performed using a transperitoneal approach, guided by a dynamic scanner. A correct diagnosis was obtained in punctures performed on 14 patients (93%); 12 patients had true positive results and 2 had true negative results. One patient had a false negative result; no false positive diagnoses were found. There were no complications related to the biopsies.

Adult↗

Morphologic changes, mucin secretion, carcinoembryonic antigen (CEA) and peanut lectin reactivity in colonic mucosa of patients at high risk for colorectal cancer.

We studied 393 endoscopic colonic biopsies from 72 patients, classified in different groups after assessment of their risk factors, using: histologic, histochemical and immunohistochemical techniques (CEA-PAP and PNA-Px). In high risk patients (Groups A and B) the most relevant modifications were dysplasia with hyposecretion and hyperplasia with sialomucin secretion (TR-type change); in Group A 31 adenomas and 19 hyperplastic polyps also were found. A premalignant nature of dysplasia and predysplastic significance of TR change were suggested: 1) by finding the same alterations in mucosa of Group E (colectomized patients for carcinoma at after 1 year); 2) by increasing expression of CEA and PNA-Px ligands; 3) by their absence in Group D (normal controls). Hyperplastic polyps were confirmed not to be premalignant lesions, but since they had peculiar characteristics (increased CEA and PNA-Px positivity, association with adenomas) it does not seem justified to regard them as lesions unrelated to colorectal cancer, especially when associated with other risk factors. CEA and PNA-Px reactivity correlated well with the risk evaluation and with morphohistochemical changes in the mucosa; the reactivity significantly increased from normal mucosa to dysplasia.

Adenoma↗

[Unilateral monorchidism and cryptorchism. Clinical and biological findings useful in the differential diagnosis].

Eighteen prepuberal children with only one testis palpable in the scrotum were studied in order to review the clinical and endocrinological data useful for differentiating monorchidism from unilateral cryptorchidism. Compensatory testicular hypertrophy, high LH and FSH response to LH-RH (100 micrograms/1.73 m2) and well preserved Leydig cell function after HCG (5,000 IU/m2) should lead to the diagnosis of monorchidism, either both congenital or secondary to severe atrophy of the unpalpable testis. When these findings are lacking the diagnosis of unilateral cryptorchidism should be considered.

Child↗