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Biomedical subjects

A Russo

Publications and source records attributed to A Russo.

At least 523 records · Page 29Linked to original sources
PubMed1988

Nitrilotriacetic acid (NTA) induces aneuploidy in Drosophila and mouse germ-line cells.

The ability of nitrilotriacetic acid (NTA) to induce aneuploidy was studied in the germ line of both Drosophila and the mouse. The Free Inverted X Chromosomes (FIX) genetic system, adopting a brooding scheme, was used to detect induced aneuploidy in Drosophila, and a cytogenetic method based on chromosomal counting in secondary spermatocytes was used in the mouse. In Drosophila a highly significant (P less than 0.001) increase of aneuploidies was produced by NTA (5 x 10(-2) M), which was greater than that produced by colchicine (7.5 x 10(-6) M) and 5-fluorodeoxyuridine (10(-4) M), which were used as positive controls. Brooding effects were observed with NTA, which produced a maximum induction of chromosomal gain in brood I, suggesting a possible stage-specific action during meiosis. The ability of NTA (275 mg/kg body weight) to induce meiotic aneuploidy (hyperhaploidy) also was confirmed in the mouse (P less than 0.001), where all the aneuploidies detected were attributable to treatment of the metaphase I stage.

Acetates↗
PubMed1988

Photodynamic therapy: response of normal canine urethra using a cylindrical fiber.

Normal urethral response to photodynamic therapy (PDT) utilizing a cylindrical fiber was assessed in ten study and two control NIH fox-hounds. The canine urethras were treated 48 hours after intravenous injection of 3 mg/kg dihematoporphyrin ether (Photofrin II). A 1-mm fused silica optical fiber, with the distal 2-3 cm modified for cylindrical light distribution (660-microns diameter), was placed in the pendulous urethra. An argon-pumped dye laser delivered 100 mW of 630-nm light for 7 minutes (42 J) to the treatment area. Urethroscopy using either a 2.5-mm or a 2.8-mm flexible pediatric bronchoscope with video recording capability was performed immediately after PDT (12 animals) and 6 weeks later (nine animals); intravenous urography was performed 3 days and 6 weeks after PDT. There was no evidence of either urethral damage or stricture formation in any animal. Histopathology of the first three study specimens, obtained at 6 weeks, confirmed the absence of any pathology. Flexible instrumentation facilitates post-treatment assessment. This study demonstrates for the first time that, when a cylindrical fiber is used, photodynamic therapy may be applied to the urethra without damage to the normal urethral mucosa. This result has implications for potential treatment of initial or recurrent carcinoma in situ of the urethra using PDT.

Animals↗
PubMed1988

Early and late complications of endoscopic oesophageal varices sclerotherapy.

We report the complications of perendoscopic sclerotherapy observed during treatment of oesophageal varices in 104 patients and 409 sclerotherapy sessions. Complications were related to each individual session and to the aim of the treatment (therapeutic or prophylactic). Major complications occurred in 17.3% of the patients treated: 13 cases of severe bleeding and 5 of oesophageal stricture. Conservative therapy stopped haemorrhage in all but 4 patients, who died of uncontrolled bleeding (3.8%). Three oesophageal strictures recovered spontaneously, while the remaining two required endoscopic dilations. Minor complications occurred after 102/409 sessions (24.9%). Epigastric and/or retrosternal pain developed after 17.6% of the sessions, oesophageal ulcerations after 12.5%, fever after 11.7% and transient dysphagia after 3.7%. Bleeding was observed only in Child's category C patients who underwent therapeutic treatment. The risk of bleeding remained unchanged until complete eradication of varices was achieved. The incidence of minor complications did not correlate with the progression or the aim of the treatment.

Adolescent↗
PubMed1988

Meiotic arrest and aneuploidy induced by vinblastine in mouse oocytes.

Young superovulated female mice were injected i.p. with single doses of vinblastine sulfate just before the onset of the first meiotic division. Secondary oocytes, fixed one by one on a slide, were cytogenetically scored. Evidence of the meiotic arresting activity of vinblastine was produced by the observation of increasing frequencies of M1-arrested oocytes and by the presence of undegenerated chromosome sets of first polar bodies. When the first meiotic division could be undertaken chromosome malsegregation occurred with high frequency, both in terms of aneuploidy and polyploidy. M1-blocked and polyploid oocytes have been interpreted as the consequence of irreversible damage to the spindle induced by vinblastine through its binding on tubulin low-affinity sites; this reaction, in fact, causes microtubule crystallization. According to this mechanism, dose-effect relationships of both phenomena show a threshold at 0.45 mg/kg. On the other hand, the incidence of aneuploid oocytes is correlated with meiotic delay, as detected by the delayed degeneration of polar bodies, and increases linearly with dose. Both phenomena are, therefore, stochastic and can be referred to the binding of the chemical on tubulin high-affinity sites, which is known to cause tubulin depolymerization in a colchicine-like way.

Aneuploidy↗
PubMed1988

Response of normal canine ureter to photodynamic therapy using a cylindrical fiber.

Photodynamic therapy (PDT) was performed utilizing a cylindrical optical fiber to determine feasibility of distal ureteral treatment on 10 study and two control NIH foxhounds. The study animals were administered three mg./kg. dihematoporphyrin ether (Photofrin II) intravenously followed 48 hours later by open cystotomy. One ureter was irradiated with 42 joules of 630 nm. light delivered by a 660 micron diameter optical fiber modified for cylindrical light distribution. Intravenous urography was performed both at three days and six weeks post PDT. Hydroureteronephrosis was revealed in one treated ureter and one untreated ureter. Mild dilatation of the ureter was noted by urography in another treated ureter and in one ureter that did not undergo light irradiation; no distal obstruction was revealed in either case by proximal infusion of saline or by histopathology. Nine of the 10 treated ureters were found to have either no abnormal pathology or only minimal lymphocytic infiltration. In this study, the normal ureter was shown to tolerate photodynamic therapy at energy densities equivalent to those used to effect tumor regression and the feasibility of using a cylindrical optical fiber for treatment of ureteral malignancies was confirmed.

Animals↗
PubMed1988

Glutathione and related enzyme activity in human lung cancer cell lines.

Glutathione levels were measured in 30 human lung cancer lines. Lower levels were detected in cell lines derived from small cell lung cancer specimens compared to non-small cell lines (mean 42 vs. 130 nmol mg-1 protein, P = 0.005). However, no difference were detected between cell lines derived from previously untreated patients, compared to those derived from patients who had received chemotherapy. Non-small cell lines were found to have increased activity of 4 detoxification enzymes compared to small cell lines, although these differences did not reach statistical significance: glutathione transferase activity (69 vs. 36 units, P = 0.137), glutathione reductase (139 vs. 82 units, P = 0.05), gamma-glutamyl transpeptidase (9.39 vs. 3.03 units, P = 0.072) and superoxide dismutase (20 vs. 13.6 units, P = 0.137). As the cell lines exhibit a similar chemosensitivity pattern to that observed in clinical practice, these differences in glutathione and detoxification enzyme levels may prove to be important indicators of intrinsic drug resistance often seen in patients with non-small cell lung cancer.

Carcinoma, Non-Small-Cell Lung↗
PubMed1988

Photodynamic therapy.

Photodynamic therapy (PDT) is an experimental cancer treatment modality that selectively destroys cancer cells by an interaction between absorbed light and a retained photosensitizing agent. This review discusses the basic components of photodynamic activity and examines the clinical applications of photodynamic therapy in cancer treatment. Treatment of superficial and early-stage malignancies is encouraging. Technologic advancement and further elucidation of the fundamental basis of photodynamic action should permit treatment of more advanced malignancies.

Fluorescence↗
PubMed1988

Carcinoma of the lung, stage III. Experience with the new TNM-AJCC classification.

The records of 228 patients who underwent surgery for primary lung cancer in 1970-1986 were reviewed. In 115 cases (94 men, 21 women) the disease was in stage III according to the 1978 classification of the American Joint Committee on Cancer (AJCC). These 115 cases were retrospectively reassessed, using a recently proposed new TNM classification with subdivision of stage III into IIIa, in which the patients may benefit from surgery, and IIIb, in which surgery is not advisable. Stage IIIa disease was present at operation in 87 cases and stage IIIb in 28. Actuarial analysis of survival rates showed that the new subclassification permits identification of those stage III patients who may benefit from surgical therapy.

Actuarial Analysis↗
PubMed1988

Closed versus open technique in the management of labyrinthine fistulae.

A labyrinthine fistula is the most common complication of cholesteatomatous chronic ear disease. Its treatment remains a controversial subject. The present paper reports our approach to the management of this complication. Operations were performed on 1,226 cases of chronic otitis media with cholesteatoma between January 1971 and December 1985. A labyrinthine fistula was detected in 158 cases. We favor intact canal wall tympanoplasty even in the presence of medium or large fistulas: in the latter case, the matrix is not removed but is trimmed to cover only the bony defect and it is left in place. Open procedures with the preservation of the matrix over the fistula are done in an only-hearing ear with fistula, in ears with a wide defect of the posterior canal wall, and in ears with multiple labyrinthine fistulas. The management of the matrix over the fistula and the anatomic and functional results following each type of procedure are presented and discussed.

Cholesteatoma↗
PubMed1988

Chinese hamster pleiotropic multidrug-resistant cells are not radioresistant.

The inherent cellular radiosensitivity of a Chinese hamster ovary pleiotropic cell line that is multidrug resistant (CHRC5) was compared to that of its parental cell line (AuxB1). Radiation survival curve parameters n and D0 were 4.5 and 1.1 Gy, respectively, for the CHRC5 line and 5.0 and 1.2 Gy, respectively, for the parental line. Thus, the inherent radiosensitivity of the two lines was similar even though key intracellular free radical scavenging and detoxifying systems employing glutathione, glutathione transferase, and catalase produced enzyme levels that were 2.0-, 1.9-, and 1.9-fold higher, respectively, in the drug-resistant cell line. Glutathione depletion by buthionine sulfoximine resulted in the same extent of aerobic radiosensitization in both lines (approximately 10%). Incorporation of iododeoxyuridine into cellular DNA sensitized both cell lines to radiation. These studies indicate that pleiotropic drug resistance does not necessarily confer radiation resistance.

Animals↗