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Biomedical subjects

P Russo

Publications and source records attributed to P Russo.

At least 289 records · Page 16Linked to original sources
PubMed1990

Aberrant cervical thymus in children: three case reports and review of the literature.

Aberrant migration of thymic tissue occurs with ectopic thymus in the mediastinum, base of the skull, tracheal bifurcation, and cervical region. A recent review of the literature showed a total of 76 reported cases of aberrant thymus or thymic cysts in patients who presented with primary neck masses. We report three additional cases of ectopic cervical thymus. All three patients presented with asymptomatic cervical masses, and preoperative diagnosis included branchial cleft cyst, cervical lymphangioma, and cervical teratoma. All patients underwent complete surgical resection of the masses. Aberrant cervical thymus rarely produces symptoms because it does not invade contiguous strictures. Despite its rarity, it should be considered in the differential diagnosis of asymptomatic neck masses in children.

Child↗
PubMed1990

Subcellular localization of rev-gene product in visna virus-infected cells.

The 1.4-kb mRNA of visna lentivirus is expressed early during the lytic infection of sheep choroid plexus cell cultures. It encodes for visna early gene 1 (VEG1) product, since renamed rev gene product (or Rev), based on significant amino acid sequence homologies between this protein and the proteins of simian immunodeficiency virus of macaque and human immunodeficiency virus type 2. In this report, we examined the subcellular localization and time course appearance of the Rev protein in visna virus-infected cells. Immunoprecipitation assays of [35S]methionine-labeled cell lysates with antisera raised against the Rev protein revealed a polypeptide of 19 kDa (p19rev). This protein was predominant early in the viral replication cycle and accumulated preferentially in the cytoplasmic/membrane fraction of infected cells. Indirect immunofluorescence staining of infected cells confirmed the cytoplasmic location of visna Rev protein and could reveal in some stained cells a higher concentration of Rev at the cellular plasma membrane. The regulating protein, still present late in the viral lytic cycle, is packaged into mature viral particles along with the structural gag and env gene products.

Animals↗
PubMed1990

Computer analysis of ENG spectral features from patients with congenital nystagmus.

Power spectral estimation from electromystagmographic recording of eye position is proposed as a simple digital processing method to quantify both the amplitude and the frequency features of eye motion in patients affected by the oculomotor disorder of congenital nystagmus (CN). Different basic wave shapes clinically identified and studied in the literature are shown to have slightly different power spectra, which can be used to characterize the CN disorder from nystagmus waveforms. This treatment, statistical in nature, does not depend strongly on the detailed structure of each recorded wave shape, thus emphasizing that accurate descriptive analysis of all patient's waveforms characteristics adds little to the comprehension of CN. We show that the power spectral estimation also represents a useful tool in modelling both the CN defect and the non-defective oculomotor system, and in assessing the effect of the surgical treatment of CN through the differences in the power spectra before and after surgery.

Electronystagmography↗
PubMed1990

Quantitative measurements of porphyrin pigments in tissues via photoacoustic spectroscopy.

We investigated the possibility of using photoacoustic spectroscopy as an analytical technique for the quantitative measurement of injected porphyrins in tissues. Samples of liver excised from treated (i.e., injected 24 h in advance with 100 mg/kg Photofrin II) mice and control mice were lyophilized and reduced to powder; then, about 16-mg powder samples were compacted to equal volumes inside the photoacoustic cell. Amplitude and phase spectra were measured in the range 280-760 nm. From these data we computed the photoacoustic absorbance spectra; they were suitably normalized in order to account for differences in hemoglobin concentration among the livers of different mice. The absorbance difference spectra (treated minus control) were computed in the region of wavelengths above 450 nm, where porphyrins and hemoglobin exhibit major differences. Finally, by estimating the value of the thermal diffusion length of the powdered sample and those of the extinction coefficients of the most relevant Photofrin II components in the spectral region considered, we were able to evaluate the local drug concentration and determined a value (260 micrograms/g of wet tissue) that is in the range expected for the dose of Photofrin II injected.

Acoustics↗
PubMed1990

Quantitative photoacoustic spectroscopy of cataractous human lenses.

Quantitative photoacoustic spectra of the nuclei of cataractous human lenses with various degrees of colouration and opacification were measured in the spectral range 250-600 nm. The lens nuclei were obtained from 20 cataractous patients through extracapsular cataract extraction. These measurements yield the light loss per unit path length in the nucleus of cataractous lenses.

Acoustics↗
PubMed1990

Neoadjuvant chemotherapy in invasive bladder cancer: the evolving role of surgery.

The role of an operation in patients receiving neoadjuvant chemotherapy for clinically localized but invasive transitional cell carcinoma of the bladder currently is evolving. An operation is essential for case selection and evaluation of local response but it also contributes to bladder preservation and survival. The procedure that is necessary to select for and assess response to chemotherapy may itself alter the actual or proceed to evolution of invasive bladder cancer. Neoadjuvant chemotherapy is a reasonable therapeutic strategy in selected patients but it remains to be seen whether the results will prove to be superior to those achieved with standard endoscopic and open operations.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

Effects of disinfecting solutions on tonometer tips.

We investigated the effects of selected disinfecting solutions on the structural integrity of Goldmann applanation tonometer tips. Hydrogen peroxide, isopropyl alcohol, dilute sodium hypochlorite (household bleach), and glutaraldehyde-phenate (Sporicidin) have been used for disinfecting tonometer tips. However, the effect of these solutions on the tips' structure has not been fully investigated. Haag-Steit tonometer tips were soaked separately for 30 days (723 h) in 5 different solutions and distilled water, approximately 1 working year of routine use (310 days by 14 patients per day). During the soaking period, the tips were regularly removed from solution, examined through a slitlamp, measured with vernier calipers, and photographed to monitor for structural degradation. Alcohol was the only solution that damaged the tips. The other disinfecting solutions appear to be safe for use on the tips after the equivalent of 1 working year of routine use.

1-Propanol↗
PubMed1990

The role of acinar zone 3 hepatocytes in bile formation: influence of bromobenzene treatment on bile formation in the rat.

The role of zone 3 hepatocytes in bile formation was determined when they were selectively destroyed by 3.8 mmol/kg b.w. of bromobenzene injected i.p. for 48 h, as compared to appropriate controls. Bromobenzene treatment resulted in 29 +/- 4.4% hepatic lobule necrosis localized in the zone 3 hepatocytes. Although bile flow and bile salt-independent flow were not affected, this treatment was associated with a significant reduction in bile salt, and phospholipid secretion. The bile salt pool and bile salt synthesis were also significantly decreased. These results suggest that necrosis of zone 3 hepatocytes induced by bromobenzene reduced bile acid synthesis which decreased bile salt pool and affected bile salt and phospholipid secretion rates. However, necrosis of zone 3 hepatocytes did not affect bile flow or the bile salt-independent flow, suggesting that hepatocytes of zones 1 and 2 maintained the normal bile salt-independent flow when zone 3 hepatocytes were damaged.

Animals↗
PubMed1990

Cholic acid and chenodeoxycholic acid transport in the hepatic acinus in rats. Effect of necrosis of zone 3 induced by bromobenzene.

The transport of cholic acid (CA) and chenodeoxycholic acid (CDC) and their influence on bile formation was investigated in rats treated with bromobenzene (BZ), a toxicant which selectively destroys zone 3 of the hepatic acinus. The necrosis equals 27-31% of the acinus cells. The absence of zone 3 in rats reduced the secretory rate maximum of CA and CDC by 18% (NS) and 25% (p less than 0.05), respectively. The maximum bile flow was not different from control during CA infusion but was lower during CDC infusion in BZ-treated animals. Although the bile acid concentration was lower in BZ-treated rats, only values obtained during the basal period and the beginning of the infusion reached the level of statistically significant difference. The bile salt-independent flow (BSIF) was not affected by the absence of zone 3. Our data suggest that zones 1 and 2 of the hepatic acinus can compensate for the secretion of CA and elaboration of BSIF when zone 3 is destroyed. However, necrosis of zone 3 reduces CDC secretion. Thus, the capacity for bile acid transport of the hepatocytes of different zones in the hepatic acinus may differ according to the circulating bile acid.

Animals↗
PubMed1990

Generation and characterization of a low-degree drug-resistant human tumor cell line.

A 2780 human ovarian cancer cells, obtained from an untreated patient, have been exposed to a relatively low, clinically maintainable dose (10 nmol/l) of the anthracycline doxorubicin (DX) to derive a low-degree (5-fold) drug-resistant subline (A2780-DX1). Compared to parental cells, these DX-resistant cells have increased size (+60% of cell volume) and contain a greater number of cytoplasmic vacuoles as determined by electron microscopy. When exposed to several other antiproliferative drugs, A2780-DX1 cells were highly cross-resistant (greater than 10-fold) to epirubicin, mafosfamide and cisplatin and slightly cross-resistant (2- to 3-fold) to navelbine and bleomycin, while they retained the original sensitivity to vinblastine, Ara-C and fluorouracil. Gel electrophoresis of cytoplasmic membrane proteins showed differences between the pattern of parental A2780 sensitive and A2780-DX1 cells as far as low-molecular-weight proteins (less than 45 kD) are concerned, while no clear overexpression of P-glycoprotein (P-170) could be detected. Membrane modifications yielding a decrease of both DX uptake and retention, increased content of intracellular glutathione (+32%) and reduced DNA double-strand breaks seem to be involved in the resulting multidrug-resistant phenotype of A2780-DX1 cells.

Antineoplastic Agents↗
PubMed1990

Frequency distribution of the time interval between quick phase nystagmic eye movements.

We measured the frequency distribution of the time interval between quick phases of nystagmic eye movements in 8 patients with congenital nystagmus. For each patient we recorded a 3- to 4-second long electro-oculographic (EOG) signal, repeating each session 22 times. The period of the nystagmic cycles was computed for each record, by evaluating the peak frequency of the nystagmic oscillations via spectral analysis of the EOGs. This period is a measure of the time interval between quick phases. Its distribution ranged between 100 and 600 ms and peaked at about 240 +/- 50 ms, with a gaussian shape for values less than about 300 ms. Our measurements were considered as providing the distribution of intersaccadic latencies in normal humans.

Adolescent↗
PubMed1990

Epstein-Barr virus polymorphic B-cell lymphoma associated with leukemia and with congenital immunodeficiencies.

Polymorphic B-cell lymphoma seen in four patients with congenital immunodeficiencies and in two patients with leukemia receiving chemotherapy was associated with the Epstein-Barr virus (EBV). The tumors had characteristic histologic features: they were polymorphic consisting of a mixture of lymphoblasts and differentiated cells including plasma cells, and areas of hemorrhagic necrosis were prominent. The tumors were either polyclonal, monoclonal, or multiclonal. Patients with congenital immunodeficiencies who developed these tumors died despite radiotherapy, corticosteroids plus acyclovir, or a combination of intravenous (IV) immunoglobulins and alpha 2 interferon. Patients with leukemia recovered when immunosuppressive drugs were discontinued and leukemia has not recurred over a period of 2 and 4 years, respectively, in the two patients.

Antineoplastic Agents↗
PubMed1990

Fetal lobation. An anatomo-ultrasonographic correlation.

Remnants of the fusion of fetal renunculi have been mistaken for renal scars or tumors. We compared anatomic cuts of 24 cadaveric kidneys with fetal lobation (ages ranged from 16 weeks gestation to 49 years) to identical ultrasonographic sections performed in a water bath and to sonograms of healthy persons of similar ages as the cadavers. Fetal lobation was characterized as follows: there were fine, linear demarcations indenting the renal surface, separating normal lobes, consisting of a central pyramid and surrounding cortex. Separate renunculi seen in early fetal life progressively fuse throughout gestation, leaving interlobar grooves. During the third trimester, the renal surface becomes smoother and the interlobar grooves become invisible. One prominent indentation of the renal surface, the interrenuncular junction, incorporates perirenal fat and invaginates the anterior surface of the upper third of the kidney to the hilum and is the most easily visible remnant of fetal lobation. The sharply defined linear remnants of interlobar grooves should not be mistaken for scars, which are wider, less well defined and always associated with loss of renal cortex.

Adolescent↗
PubMed1990

[Hydrogen peroxide in the aqueous humor and cataract formation in human diabetes].

Hydrogen peroxide in the aqueous humor was measured in cataractous eyes from normal subjects and in cataractous eyes from diabetic subjects. The level of H2O2 in the aqueous humor was significantly higher in diabetes than in the idiopathic forms. It is likely that in the eye, impaired enzymic defenses lead to the accumulation of reactive species of O2, such as H2O2, which induces lipid peroxidation. This mechanism may be involved, as a direct consequence of retinal damage, in the pathogenesis of cataract in diabetes.

Aqueous Humor↗
PubMed1990

8-methoxycaffeine-induced protein-associated DNA breaks in isolated L1210 cell nuclei.

8-methoxycaffeine (8-MOC) is a caffeine derivative more potent than its parental compound in inducing chromosomal aberrations. 8-MOC has been postulated to produce chromosomal aberrations by DNA topoisomerase II inhibition. The effect of 8-MOC on nuclear DNA were studied by alkaline elution experiments and compared with those of Ellipticine and Adriamycin (ADR). Like Ellipticine and ADR, 8-MOC induced single strand breaks (SSBs), double strand breaks (DSBs), and DNA-protein cross-links (DPCs) in a bell-shaped manner with respect to drug concentration. As in the case of ADR and Ellipticine, 8-MOC induced equal SSB and DPC frequencies. These results could suggest that 8-MOC induces DNA breaks by interacting with DNA topoisomerase II or with a similar DNA metabolism enzyme.

Animals↗
PubMed1990

Promoters and inhibitors of calcium urolithiasis in children.

We have evaluated the urinary excretion of promoting (calcium, phosphorus, uric acid, oxalate) and inhibiting (citrate, magnesium, glycosaminoglycans) factors of crystallization in subjects with idiopathic hypercalciuria and calcium urolithiasis and in a control group. The examined children had a free diet and were drug free for the last 2 weeks. They were not affected by malabsorption, D-RTA, urinary tract infection, or urinary tract malformation (factors interfering with urinary excretion of citrate and oxalate). In the patients with calcium urolithiasis, the daily urinary excretion of oxalate was significantly higher (p less than 0.01), and the urinary excretion of citrate was significantly lower (p less than 0.001) than in the subjects with idiopathic hypercalciuria and in the control group. Among the subjects with idiopathic hypercalciuria, those aged 4-9 years had a significantly reduced, though in the normal range, urinary excretion of citrate as compared with those aged 10-15 years (362 +/- 189 and 503 +/- 198 mg/g creatinine/24 h, respectively; p less than 0.01). Our data show that hypocitruria may play an important role in the pathogenesis of urolithiasis in children with idiopathic hypercalciuria. In these cases, the urinary citrate excretion was not inversely related to age, as has been suggested by other authors.

Calcium↗