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Biomedical subjects

P Romano

Publications and source records attributed to P Romano.

At least 163 records · Page 9Linked to original sources
PubMed1976

Biosynthesis of sulphur amino acids in Saccharomyces cerevisiae II. Analysis of suplhite-producing strains.

A number of strains of Saccharomyces which produce sulphite by sulphate reduction were examined from an enzymatic and genetic point of view. There are a number of mechanisms that regulate this activity. All of these mechanisms involve the sulphite-reducing activity. In the strains examined, reduced function as a result of mutation in the Sr-locus (affecting H2S-NADP oxidoreductase EC 1.8.1.2), repression of biosynthesis of the enzyme because of a mutation below the specific locus, and inhibition of the enzyme by endogenous factors were found to be responsible. The production of sulphite can also be connected with a complex state of heterozygosity. It is probably this multiplicity of biochemical and genetic mechanisms that accounts for the frequency with which the production of sulphite is observed in wild strains in nature.

Methionine↗
PubMed1976

[Neuroplegia and extracorporeal circulation. Comparison between combinations of droperidol-phenoperidine and chlorprothixene-dextromoramide in cardiac surgery].

After a quick review of the physiopathology of extra-corporeal circulation, the value of the use of neuroplegic drugs in cardiac surgery is recalled by means of pharmacological arguments. The experimental differences existing between the combinations droperidol - phenoperidine and chlorportixene - dextromoramide, on the rate of flow and on the pressure of the perfusion, and on the esophago-rectal thermic gradients during E.C.C. is then demonstrated. Statistic calculation confirmed the superiority of chlorprotixene in the realm of tissue perfusion during E.C.C. under hypothermia.

Adult↗
PubMedDate not supplied

The interaction of haemoglobin, magnesium, organic phosphates and band 3 protein in nucleated and anucleated erythrocytes.

The anion influx was measured in order to study the interaction among organic phosphates, magnesium, haemoglobin and the N-terminal of the cytoplasmic domain of band 3 protein in human, chicken and trout erythrocytes. The rate constant for SO(4)(2-) influx in human and trout erythrocytes increased significantly when it was measured with an increased concentration of intracellular Mg(2+). The SO(4)(2-) influx was also measured in human erythrocyte ghosts in the presence and absence of Mg(2+). The smaller activation provoked by Mg(2+) in ghosts could be caused by the presence of a small quantity of haemoglobin which remained inside. The SO(4)(2-) uptake in chicken erythrocytes in the presence and in absence of Mg(2+) was characterized by very similar rate constants. The results suggest that the small increase in intracellular Mg(2+) in the erythrocytes involves an increase in the formation of Mg(2+)-ATP and Mg(2+)-2,3 BPG complexes reducing the affinity of the organic phosphates for Hb. This new situation may influence the functions of the anion transporter with consequent variations of SO(4)(2-) influx throughout the erythrocyte membrane in human and in trout erythrocytes, whereas in chicken RBCs this function cannot occur and, in fact, no increase in sulphate influx was noticeable. The measurement of Hb/O(2) affinity by the use of alternating fixed and variable concentrations of organic phosphates and Mg(2+), confirms the interactions between these elements and their effect on the mechanism of the affinity. When we measured the sulphate influx in the presence of DIDS we found some differences in the three types of cells.

2,3-Diphosphoglycerate↗
PubMedDate not supplied

Compartmentalization of lysosomal enzymes in cauda epididymis of normal and castrated rats.

The mammalian epididymis is an organ particularly rich in acid hydrolases, consistent with a developed lysosomal apparatus. However, some of these enzymes could also play a role in an extracellular environment, since they are actively secreted by the epithelium. In this study the authors measured the activity of five acid hydrolases distributed between the epithelium, fluid, small vesicles, and spermatozoa of the rat cauda epididymis in adult rats, and compared with that distribution under conditions of deprivation of luminal testosterone and testicular compounds (hemicastration). Lysosomal enzymes are differently compartmentalized in rat cauda epididymis. Most of beta-galactosidase (beta-GAL) and aryl sulfatase (approximately 70%) were found in soluble form within the fluid. Some 60% of N-acetyl-beta-D-glucosaminidase (beta-NAG) and alpha-mannosidase (alpha-MAN) become transiently bound to sperm, and beta-glucuronidase (beta-GLU) was mostly concentrated in the epithelium. After remotion of testis this distribution changed, as the retention of alpha-MAN, beta-GAL, beta-GLU, and beta-NAG by the epididiymal tissue increased. The increase of beta-GLU followed an increase of synthesis of the enzyme. The distribution of enzymes in the epididymis from the contralateral side was similar to that in normal rats. The different roles for each enzyme in the epididymis are discussed.

Acetylglucosaminidase↗
PubMedDate not supplied

Effects of plasma total ammonia content and pH on urea excretion in Nile tilapia.

Nile tilapia (Oreochromis niloticus) were infused with ammonium salts, acid, and base to investigate the effects of changes in arterial plasma total ammonia content (Tamm) and pH (pHa) on plasma urea-nitrogen (urea-N) levels and urea-N excretory fluxes (Jurea-N). The tilapia did not possess a functional hepatic ornithine urea-cycle (no significant carbamyl phosphate synthetase III activity). Infused substances were dissolved in a saline vehicle and injected twice (5 mL kg-1), the first infusion to "prime" the animal and promote a more marked response to the second infusion, given 2.5 h later. The results reported are those of the second infusion. Infusion of 200 mM NH4Cl increased Tamm, reduced pHa, and increased plasma urea-N and Jurea-N. Two hundred mM NH4HCO3 increased Tamm and arterial plasma total CO2 content (TaCO2), reduced pHa, and increased Jurea-N. Fifty mM HCl reduced pHa but had no effects on urea dynamics. Fifty mM NaOH increased pHa, plasma urea-N levels, and Jurea-N. Two hundred mM NaHCO3 increased pHa, TaCO2, plasma urea-N levels, and Jurea-N. Infusion of the saline vehicle was without effect. The results indicate that ammonia loading and plasma alkalosis both stimulate urea excretion in uricolytic fish. The responses to hyperammonemia or alkalosis were not modified when combined with elevated plasma bicarbonate levels.

Alkalosis↗
PubMedDate not supplied

Detection of bronchial abnormalities: comparison of CT and bronchoscopy.

We evaluated the usefulness of CT as compared with both visual and pathologic findings from fiberoptic bronchoscopy (FOB) in detecting bronchial lesions in 100 consecutive patients undergoing both procedures. There was agreement between CT and visual FOB in 83% of cases and CT and pathologic FOB in 68%. In the malignant disease category CT detected bronchial abnormalities in 59% (27 of 46) as compared with 57% (26 of 46) by visual FOB; both agreed in 81% of the cases (37 of 46). On the basis of CT findings alone, we retrospectively divided the cases into those for which we expected FOB to have high diagnostic yield (peribronchial abnormalities, n = 49) and a low diagnostic yield (i.e., no bronchial abnormality, n = 51). For the malignant disease category, selection by CT findings resulted in successful diagnosis by FOB in 69% for the high yield group as compared with 29% for the low yield group. We conclude that CT has excellent correlation with visual and pathologic results of FOB in detecting bronchial abnormalities and that CT, when used as an initial screening test, can enhance the yield by allowing appropriate selection of patients.

Bronchial Diseases↗
PubMedDate not supplied

Regional cerebral blood flow in essential hypertension: data evaluation by a mapping system.

Regional cerebral blood flow was studied by means of the 133Xe inhalation method in 26 untreated and 10 treated patients with essential hypertension. The untreated subjects were divided into newly and previously diagnosed groups to assess the relation between regional cerebral blood flow and the duration of hypertension. The overall flow reduction was more marked in the frontal and temporal regions in the previously diagnosed group, and this was attributed to pathological changes in the district served by the middle cerebral artery. Regional temporal lobe impairment was also noted in the newly diagnosed and treated subjects. A significant correlation was found between regional cerebral blood flow and mean arterial blood pressure.

Aged↗
PubMedDate not supplied

Immunosuppressive acidic protein (IAP) and CA 125 assays in detection of human ovarian cancer: preliminary results.

Serum levels of the immunosuppressive acidic protein (IAP) and CA-125 were measured in 45 patients with ovarian tumors (30 malignant and 15 benign) before surgery. Concentrations of both markers were slightly increased in benign forms but still within the upper limit for controls. The sensitivity of IAP in detecting ovarian cancer was higher than CA-125 (83.4% versus 76.7%). Five false negatives were observed in IAP assay and seven for CA-125. Parallel determination of both markers, however, improved the diagnostic accuracy up to 90.0% of the total malignant cases. Combined measurements of circulating IAP and CA-125 are therefore recommended in the detection of ovarian cancers.

Antigens, Neoplasm↗
PubMedDate not supplied

Measured graduated recession of the superior oblique muscle.

Six patients underwent bilateral superior oblique recession for A-pattern strabismus with overacting superior obliques. The established technique was modified to permit the entire procedure to be carried out through a single nasal fornix incision. The amount of recession was graduated and measured both directly from the point of the original incision anteriorly and indirectly from the nasal of the corner of the superior rectus insertion based on anatomical measurements. A good correlation was found between the amount (measured directly) of recession performed and reduction in the A-pattern. The relationship was linear. By extrapolation the first 8 mm of superior oblique surgery had no effect but thereafter the effect obtained was 2 diopters reduction in A-pattern for every mm of superior oblique surgery. No similar correlation was found for the amount of recession performed measured indirectly. There was no correlation between reduction in superior oblique overaction and the amount of recession performed. This was believed to be due, at least in part, to an inaccurate system of measurement of superior oblique overaction. We now, therefore, measure superior oblique overaction in mm using the corneal light reflexes. There was, however, a good correlation between the amount of preoperative superior oblique overaction and the effect obtained.

Follow-Up Studies↗
PubMedDate not supplied

An ultrastructural study of the Antarctic calanoid Copepod Metridia gerlachei giesbrecht, 1902. Adult female.

Scanning electron microscopy (SEM) techniques can highly contribute to the knowledge of body structures in order to differentiate between different species or between varieties within the same species. This is particularly important in extreme environments, such as in Antarctic waters, where the evolution efforts have promoted the development of endemisms. In this work the external anatomy of Metridia gerlachei (Copepoda, Calanida) adult females, sampled during the Italian Oceanographic Campaign in Antarctica 1987-88, was described by SEM, particularly considering some swimming legs and the genital abdominal joint. The descriptions already reported have been verified and some morphological details have been better emphasized. As concerns the P2, the hook process of the first segment of endopod and a series of spines vaguely indicated, but not defined, in previous descriptions have been clearly evidenced. In the P5 the occurrence of three well separated free segments and the location of a marginal sets have been shown. The ultrastracture of the genital segment showed that a clear areola surrounds the genital field.

Animals↗