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Biomedical subjects

A Orlacchio

Publications and source records attributed to A Orlacchio.

At least 109 records · Page 6Linked to original sources
PubMed1990

Optimal branching of human arterial bifurcations.

The area ratio, defined as the combined cross-sectional areas of the daughter branches divided by that of the parent artery, is an important indicator of "expansion" or "narrowing" in an arterial tree. In 120 morphologically normal human arterial bifurcations, angiographically studied, we measured branch artery diameters at and away from the bifurcation point to obtain "beta" and "D" ratios, respectively. These results were compared with optimal curves. Area ratio D values showed better agreement than area ratio beta with theoretical curves; for area ratio D, the positive regression line showed the same trend as expected from theory (y = 1.26 + 0.153x); for area ratio beta, the regression line was negative, showing a trend opposite to theory (y = 0.962 - 0.191x). Area ratio beta showed a significant correlation coefficient (r = 0.194; P less than 0.05) associated with aging, while for area ratio D it was not the same (r = 0.023; P less than 0.05). A significant correlation coefficient was also found between both of the area ratios and total branching angle. The new area ratio D, reflecting the branching geometry nearer to the bifurcation, is more promising than area ratio beta in the evaluation of optimal arterial bifurcation.

Adolescent↗
PubMed1989

beta-N-acetylhexosaminidase isoenzymes during chick embryo development.

1. Two forms (I and II) with acidic pH optima and a neutral form of beta-hexosaminidase has been separated by DEAE-cellulose chromatography and characterized in skin and lung of 7, 9, 11, 14 day chick embryos and 1 day old chicken. 2. Forms I and II are similar to hexosaminidase A and B for their behaviour on DEAE-cellulose chromatography, Concanavalin A-Sepharose column and thermal stability. 3. Neutral form has a neutral pH optimum and higher molecular weight and a more acidic I. P. than forms I and II, a low beta-N-acetylgalactosaminidase activity and it is not bound by a Concanavalin A-Sepharose column and in that resemble hexosaminidase C and/or other neutral hexosaminidases. 4. We have found differences in the percentage of neutral form and in the specific activities of the extracts in the skin in different stages of development. 5. No significant differences were observed in the lung.

Animals↗
PubMed1989

[Magnetic resonance in hepatic lesions. Experience with a 1.5-T magnetic field].

Forty-one patients with histologically proven hepatic lesions (6 cysts, 6 hemangiomas, 8 hepatomas, 19 metastases and 2 negative cases) were studied with Magnetic Resonance (MR) imaging at 1.5 T, and with US and CT. This prospective study was aimed at evaluating: the comparative accuracy of MR, US and CT; the sensitivity and specificity of spin-echo (SE) vs FISP pulse sequences; the efficacy of T1 and T2 relaxation time values in differentiating hemangiomas from hepatomas and metastases. MR diagnostic accuracy was 94.7% vs 89.4% of CT and 84.2% of US. FISP sequences provided 60% sensitivity and 66% specificity. T2 relaxation time values were statistically significant (p less than 0.05) in differentiating hemangiomas (T2 range: 80.9-218.9 ms) from hepatomas (T2 range: 59.4-83.2 ms). The differences in mean T2 values between hemangiomas and metastases (T2 range 54.3-177.3 ms) were not statistically significant (p greater than 0.25).

Carcinoma, Hepatocellular↗
PubMed1989

[Transvaginal echography: initial experiences in oncologic gynecology].

The authors report their initial experience in a selected group of 30 patients with suspected gynecological neoplasms (10 ovarian tumors, 8 recurrences of ovarian tumors, 6 cervical carcinomas, 3 ovarian cysts, 3 fibromyomas) who underwent both transabdominal (US) and transvaginal (TV) sonography. All the scans were retrospectively reviewed. In 18 cases US and TV provided equivalent information as to the organ of origin of the mass, while TV was more useful in 9 cases, and US in 3 cases. The anatomical relationship of the mass to the adjacent organs was better demonstrated by TV in 15 cases, while in 15 cases the information provided by US and TV was equivalent. The two techniques yielded the same results as to the internal architectural details of the mass in 9 cases, while TV was superior in 18 cases and US in 3 cases. TV allowed the early identification of: small amounts of free fluid in the cul-de-sac in 3 cases, compression of the ureter in 1 case, and compression of the uterine vessels in 1 case. These findings had not been demonstrated by US. Our preliminary results indicate that adjuvant TV sonography provides important diagnostic information in gynecological neoplasms in about 39% of patients.

Adult↗
PubMed1989

Beta-N-acetyl-D-glucosaminidase activity in embryonic chick skin and lung tissue and cultured fibroblasts.

During development the content of mesenchymal glycosaminoglycans (GAG) undergoes prominent changes, currently considered to act as regulatory signals in the epithelial-mesenchymal interactions. The factors involved in controlling GAG composition are as yet completely unknown. Lysosomal enzymes play a key role in GAG turnover. A possible mechanism for regulating GAG content could therefore be linked to developmental modulation of lysosomal glycosidases activity. We have examined the activity of the beta-N-acetyl-D-glucosaminidase (EC 3.2.1.30; a lysosomal hydrolase cleaving glycosidic linkage of the non-reducing terminal beta-N-acetyl-D-glucosamine residues) in chick embryo skin and lung (rudiments whose GAG composition has previously been studied) at various embryonic stages. Determinations were carried out on whole organs as well as on primary cultures of fibroblasts obtained from the two rudiments. beta-N-acetyl-D-glucosaminidase activity varied greatly during development, and it was significantly different in embryonic skin and lung tissues at various incubation days. In cultured fibroblasts, the enzymatic activity varied at different incubation days correlating with the in vivo data. Developmental changes of beta-N-acetyl-D-glucosaminidase paralleled mesenchymal GAG pattern both in vivo and in vitro. Our results, therefore, support the possibility that lysosomal enzymes could be involved in the regulation of mesenchymal GAG content during development.

Acetylglucosaminidase↗
PubMed1988

Identification of beta-N-acetylhexosaminidase A in mouse tissues with the fluorigenic substrate 4-methylumbelliferyl-beta-N-acetylglucosamine 6-sulphate.

beta-N-Acetylhexosaminidase from mouse tissue was separated into its constituent isoenzymes on DEAE-cellulose and its activity was monitored with 4-methylumbelliferyl-beta-N-acetylglucosamine and 4-methylumbelliferyl-beta-N-acetylglucosamine 6-sulphate. Forms corresponding to the human isoenzymes A (acidic), B (basic) and an 'intermediate' form were present in mouse liver and spleen, whereas in kidney the B and 'intermediate' forms predominated, with A present only as a minor component. In brain the 'intermediate', A and C activities were detected. Testis had predominantly A activity, whereas epididymis, the tissue with the highest specific activity of beta-N-acetylhexosaminidase, had an abundance of the 'intermediate' form, but was almost entirely lacking in the A form.

Animals↗
PubMed1988

Age related and lectin influenced changes of exoglycosidases activity in cultured chick embryonic skin fibroblasts.

beta-N-acetyl-D-glucosaminidase, beta-N-acetyl-galactosaminidase and a beta-D-galactosidase activity was determined in untreated and lectins (ConA, PNA, SBA and WGA) treated chick embryonic skin fibroblasts at two incubation stages. Activity of all three glycosidases increased between 7 and 14 incubation days. ConA and WGA affected the levels of enzymatic activity; while SBA and PNA were uneffective. We discuss these findings in relation to a possible role of glycosidases in controlling mesenchymal GAG turnover.

Acetylglucosaminidase↗
PubMed1988

The vascular geometry of human arterial bifurcations.

We used angiography to evaluate the branching characteristics of 69 morphologically normal human arterial bifurcations. Each angiographic picture was enlarged photographically and traced on paper. The diameter of the parent vessel (d0), the diameters of the two daughter vessels (d1 and d2-d1 denote the larger vessel), and the angles at which the two branches arise from the parent vessel (teta 1 and teta 2) were measured on each bifurcation. Because theoretically there are optimal values for angles and diameters that render an arterial bifurcation more efficient physiologically, the measured data were compared with predicted values. Branch diameters correlated better with predicted values than did branching angles. Twenty-six per cent of teta 1 and only 7.2% of teta 2 angles were within the optimal range; 68.2% of teta 1 and 79.7% of teta 2 were within 2% of optimal values in terms of physiologic efficiency. On the average, teta 1 angles were smaller than teta 2 angles (17.0 degrees vs. 29.5 degrees). Morphologic and hemodynamic pecularities of vessels and errors in the measuring technique must be considered in analyzing the data obtained. Moreover, branching angle measurements changed slightly with age: teta 1 became larger and teta 2 narrower. In the cardiovascular system branching angles and branch diameters follow, to some degree, the principles predicted by theory. Branching angles diverging considerably from those principles may indicate the presence of vascular disease although a direct connection has not been established.

Adolescent↗
PubMed1987

Intermediate forms of human beta-N-acetylhexosaminidase lack activity towards 4-methylumbelliferyl beta-N-acetylglucosaminide 6-sulphate.

4-Methylumbelliferyl beta-N-acetylglucosaminide 6-sulphate was purified from a mixture containing its unsulphated precursor. The substrate was used to test for the presence of functional alpha-subunits in 'intermediate' forms of human beta-N-acetylhexosaminidase in samples of normal and pregnancy serum and in extracts of placenta and lymphocytes from a patient with common acute lymphoblastic leukaemia. Intermediate forms in these samples had no activity towards 4-methylumbelliferyl beta-N-acetylglucosaminide 6-sulphate, indicating that they lack alpha-subunits.

Chromatography, DEAE-Cellulose↗
PubMed1987

Distinct alpha-L-fucosidase isoenzyme profiles in human leukemic cells.

alpha-L-Fucosidase (EC 3.2.1.51; FUS) activity and isoenzyme characteristics were analyzed in normal lymphocytes, normal (polymorphonuclear leukocytes, PMNs), and myeloid and lymphoid leukemic cells. Chronic lymphocytic leukemia (CLL) lymphocytes had a lower mean specific activity than normal lymphocytes (2.5 vs. 4.0, p less than 0.05). Acute lymphoblastic leukemia (ALL) blasts had a higher mean specific activity compared to normal lymphocytes (9.7 vs. 4.0; p less than 0.001), CLL lymphocytes (9.7 vs. 2.5; p less than 0.001), and acute myeloid leukemic (AML) blasts (9.7 vs. 7.6; p = NS). Normal PMNs had a higher mean specific activity than normal lymphocytes (7.0 vs. 4.0; p less than 0.05) but similar activity when compared to CML cells or AML blasts. Blasts from acute myelomonocytic leukemia (AMMoL) patients had higher activity than normal PMNs (9.0 vs. 7.0; p greater than 0.05). The isoenzyme patterns of normal and leukemic granulocytes and lymphocytes were obtained by automated chromatofocusing on PBE-94 microcolumns with normal and leukemic lymphocyte lysates. With normal and leukemic lymphoid lysates two major isoenzyme components (B and A) were isolated. The isoenzyme patterns of PMN, AML, CML, and AMMoL revealed three major peaks (B, A, I), totally different from those seen in lymphoid cells. The patterns of AML, CML, and PMN appeared to be similar to each other; however, the isoenzyme pattern obtained from AMMoL cells could be distinguished from the others by a prominent I peak. Thus, the FUS isoenzyme profile distinguishes the blasts of AMMoL from AML; and AMMol and AML from ALL.

Humans↗
PubMed1987

[Use of digital subtraction angiography in the study of thoracic outlet syndrome].

Thoracic outlet syndrome (TOS) is characterized by neural and vascular symptoms of the upper extremity, caused by abnormal compression on the brachial plexus, subclavian-axillary artery and/or vein, when the patient makes some movements. Compression can occur on various anatomic levels: interscalene triangle, costoclavicular passage, pectoralis minor tendon. The authors describe the various stress position to point out the place of compression, etiology and the most common methods of study. They refer also their experience about TOS obtained using selective digital subtraction angiography (DSA) of both subclavian arteries in 6 patients. Thanks to DSA, that allows the dilution of contrast medium, it is possible to carry out all the stress maneuvers using a little amount of contrast medium.

Adolescent↗
PubMed1986

beta-N-acetyl-D-glucosaminidase isoenzymes from human amnionic membranes.

Two beta-N-acetylglucosaminidase isoenzymes (A and B) have been identified and purified from amnionic fetal membrane. The final specific activity of A and B isoenzymes increased 225- and 185-fold respectively by a purification scheme, which included a lyophilized extract, chromatofocusing on PBE 94, pH range 5.5 to 4.0, and affinity chromatography on p-aminophenyl-2-acetamido-2-deoxy-1-thio-beta-D-glucopyranoside covalently linked to Sepharose-4B. Different electrophoretic mobility, thermostability and different thiol group modifications of the two isoenzymes were found. Acetate was a more effective competitive inhibitor than were iodoacetamide, N-acetylglucosamine and N-acetylgalactosamine more than glucosamine and galactosamine, confirming a specific 'acetamido receptor site' for both the isoenzymes.

Acetylglucosaminidase↗
PubMed1986

Expression of a particular beta-N-acetylglucosaminidase isoenzyme in human haematopoietic leukemic cell-lines.

N-acetyl-beta-D-glucosaminidase (NAG) activity and isoenzyme profiles were studied in myeloid, histiocytic, B-lymphoid, T-lymphoid and lymphoblastoid continuous cell lines in order to determine if N-acetyl-beta-D-glucosaminidase isoenzyme expression may help to distinguish among various types of leukemic proliferation. Total NAG activity in myeloid, histiocytic, erythroleukemic cell lines were higher than Burkitt's lymphoma derived cell lines (B-lymphoid), T- or lymphoblastoid cell lines. On chromatofocusing by PBE 94 coupled with an automated enzyme assay an intermediate (I) beta-N-acetyl-glucosaminidase form, eluting between forms B and A, was found in all leukemic and in Epstein-Barr virus infected lymphoblastoid cell lines analysed. The different profiles recorded, the expression of the I form and the different I/B ratios may be useful as markers of tumour proliferation.

Acetylglucosaminidase↗
PubMed1986

Alteration of beta-hexosaminidase activity and isoenzymes in human leukemic cells.

beta-Hexosaminidase (EC 3.2.1.20; Hex) activity and isoenzyme characteristics were analyzed in human normal and leukemic leukocytes. Unseparated CLL and CML cells had a specific activity that was lower, whereas ALL and AML blasts had a higher specific activity than normal lymphocytes and granulocytes. CLL B-cells had a lower specific activity compared with that in normal non-T-lymphocytes; CLL T-cells and normal T-cells had similar activity. Isoenzyme separation was performed by chromatofocusing on PBE-94 coupled with an automated enzyme assay. When using a single linear pH elution gradient, normal leukocytes and all leukemia cells contained two forms of isoenzyme (B and A). When a double pH elution gradient was performed, an extra distinct form of Hex (I) was recorded. Hex I was present in small amounts in normal granulocytes and PHA-stimulated normal lymphocytes; isoenzyme I was found in high amounts in all leukemias tested. The activity ratios I/B and I/A, as well as the I isoenzyme profile, may facilitate differentiation between normal and leukemic cells and between lymphoblastic and myeloblastic leukemias.

B-Lymphocytes↗
PubMed1986

[Role and possibility of intravenous digital substraction angiography in problems of renal transplantation].

Intravenous Digital Subtraction Angiography (IVDSA) was used to evaluate 6 renal allograft recipients and 3 potential renal donors. In 4 potential renal donors and in 2 allograft recipients, angiographic data were confirmed by surgery. IVDSA is a safe, accurate, easily performed, outpatient procedure; in our opinion DSA should became the procedure of choice to study vascular anatomy in renal transplant evaluation.

Angiography↗