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Biomedical subjects

S Amato

Publications and source records attributed to S Amato.

At least 73 records · Page 4Linked to original sources
PubMed1988

The effect of testicular torsion on the contralateral testis and the value of various types of treatment.

In an attempt to investigate the effect of testicular torsion and various forms of treatment on the contralateral testis, an experimental study on rats was undertaken. The first group comprised control animals. In the second group the left testes were twisted 720 degrees and the right testes were removed 4 weeks later for histopathological examination. In the third group the rats were subjected to a left detorsion procedure 24 h after torsion, while in the fourth group cortisone treatment was added to the above procedure. The fifth group consisted of rats which had undergone left orchiectomy 24 h after torsion and the sixth group had cortisone treatment plus orchiectomy after torsion. Cortisone treatment was started 24 h after testicular torsion and continued for 4 weeks. Histopathological examination of the contralateral testes which were removed 4 weeks later showed that either orchiectomy plus cortisone or detorsion plus cortisone was more successful than other forms of treatment.

Animals↗
PubMed1986

Amphiphilic and hydrophilic forms of choline-O-acetyltransferase in cholinergic nerve endings of the Torpedo.

In the purely cholinergic nerve endings isolated (i.e. synaptosomes) from the electric organ of the fish Torpedo, the enzyme choline acetyltransferase was found to exist not solely in its well-known soluble form but also in a form which is non-ionically bound to the plasma membrane; this activity could not be solubilized in solutions of high ionic strength (0.5 M NaCl). The non-ionic detergent Triton X-114 was used to solubilize synaptosomes isolated from either the electric organ of Torpedo or rat brain. This detergent allows to separate hydrophilic from amphiphilic proteins of cells or subcellular fractions. Twelve per cent of the synaptosomal choline acetyltransferase partitioned as amphiphilic and 80-97% as hydrophilic activity. The percentage of amphiphilic activity present in synaptosomes was significantly higher than that of the form of activity (4.4%) extracted from samples containing only the soluble form of choline acetyltransferase but was significantly lower than the percentage of amphiphilic enzyme present in preparations of synaptosomal plasma membrane (20-22%) which were enriched in the non-ionically membrane-bound form of choline acetyltransferase. These results indicate that the soluble and the non-ionically membrane-bound enzymes differ in their capacity to interact with non-ionic detergents. The preparations of synaptosomal plasma membranes contained significantly higher proportions of detergent-insoluble choline acetyltransferase activity than did the whole synaptosomes; the difference was more striking for the Torpedo than for the rat enzyme. This detergent-insoluble activity was not due to aggregates of the enzyme. Some properties of the hydrophilic and amphiphilic choline acetyltransferase of Torpedo were analyzed. The two forms of the enzyme did not exhibit different affinities for their substrates; they were found to differ with respect to their sensitivity to inhibition by increasing concentrations of the two products of the reaction, acetylcholine and coenzyme A and heat inactivation at 45 degrees C. Most probably the hydrophilic and amphiphilic activities correspond to what was referred to as soluble and non-ionically membrane-bound choline acetyltransferase, respectively. The amphiphilic form may be an integral enzyme of the plasma membrane of cholinergic nerve endings or may be tightly bound to a specific protein in this membrane which may act as a "receptor" for choline acetyltransferase.

Animals↗
PubMed1985

Membrane-bound choline acetyltransferase in Torpedo electric organ: a marker for synaptosomal plasma membranes?

The enzyme choline-O-acetyltransferase catalyses the biosynthesis of acetylcholine from acetyl coenzyme A and choline and is considered as one of the best markers for cholinergic nerve endings. The distribution of this enzymatic activity was analysed during the purification of plasma membranes of purely cholinergic nerve endings isolated from the electric organ of the fish Torpedo marmorata. This tissue, which receives a profuse and purely cholinergic innervation, can be considered as being a "giant" neuromuscular synapse. The isolated nerve endings (synaptosomes) were first osmotically disrupted and their plasma membranes isolated by equilibrium density centrifugation (discontinuous followed by continuous sucrose gradients). Choline acetyltransferase activity was found to exist in three forms: (1) a soluble form (the major one) present in the cytoplasm of the nerve endings, (2) a form which is ionically associated with membranes and which can be solubilized by washing exhaustively the membrane fraction with solutions of high ionic strength (0.5 M NaCl) and (iii) a form which is non-ionically bound to membranes and cannot be solubilized with high salt solution. The soluble and the non-ionically bound activities exhibited very similar affinities for choline (1.34 and 1.64 mM, respectively). The non-ionically membrane-associated form of choline acetyltransferase was found to "copurify" with the cholinergic synaptosomal plasma membranes of Torpedo, its specific activity being increased from 122 (crude fraction) to 475 (purified membrane fraction) nmol/h/mg protein. An enrichment was also observed for another cholinergic marker, the enzyme acetylcholinesterase, but not for the nicotinic receptor to acetylcholine, a marker for postsynaptic membranes. No choline acetyltransferase activity could be detected in preparations of synaptic vesicles that were highly purified from the electric organ. Also, the non-ionically associated form of choline acetyltransferase activity was hardly detectable (2.4 nmol/h/mg protein) in fractions enriched in axonal membranes prepared from the cholinergic electric nerves innervating the electric organ. The partition into soluble and membrane-bound activity was also analysed for choline acetyltransferase present in human placenta, a rich source for the enzyme but a non-innervated tissue. In this case the great majority of the enzyme appeared as soluble activity. Very low levels of non-ionically membrane-bound activity were found to be present in a crude membrane fraction from human placenta (2.8 nmol/h/mg protein).(ABSTRACT TRUNCATED AT 400 WORDS)

Acetylation↗
PubMed1982

Ultrasonography and alpha-fetoprotein determination for antenatal detection of neural tube defects.

We review our experience in the antenatal detection of neural tube defects in a collaborative study between the prenatal diagnostic program of the Section of Medical Genetics and the Ultrasound Laboratory at the West Virginia University. In West Virginia the incidence of neural tube defects is two to three times the national average. The patients were referred to the sonic laboratory for a variety of reasons, even though they had not been classified in the high risk category. Our data confirm the advantage of ultrasonography for screening of the population in the early stages of pregnancy. The study also confirmed the value of serum and amniotic fluid alpha-fetoprotein (AFP) determination in conjunction with ultrasonography, especially when there is a positive family history. The combination of modalities appears to be the best means at present for detection of these severe disorders. Screening the general population in the early stages of pregnancy by means of ultrasonography, a noninvasive technic, can help to review fetal maturity and placental localization, as well as to detect neural tube defects. High risk mothers can then be followed up by further evaluations using serum or amniotic fluid AFP studies.

Amniotic Fluid↗
PubMed1981

[The polycystic kidney and serum alpha-1-antitrypsin deficiency. Observations on 2 family groups].

The purpose of this study was to analyze the relation between association of alpha 1-antitrypsin (AAT) deficiency (an inborn error of metabolism) and familial polycystic disease of the kidney. Emphasis is laid on coexistence of two the pathological fitness in some members of two family tree. Based on the presented findings it seems reasonable to conclude that AAT-deficiency may be correlated to the pathogenesis of polycystic kidney.

Female↗
PubMed1980

Identification of Pseudomonas aeruginosa with the API-20E system.

The API-20E multitest system was found to be capable of identifying Pseudomonas aeruginosa isolates at least to the level of the Pseudomonas fluorescens group within 18 h at 35 degrees C. Additional tests, such as the acetamide reaction, growth at 42 degrees C, and the oxidative (OF) glucose test, assisted in the speciation of P. aeruginosa.

Bacteriological Techniques↗
PubMed1978

Genetic emergencies in pediatrics.

Genetic emergencies like other medical emergencies require immediate intervention to alter the outcome of the condition in the patient and its effect upon the family. The representative conditions of myelomeningocele, Down's syndrome, cleft lip and palate and adrenogenital syndrome serve to illustrate the need for rapid and comprehensive intervention. Recognition that an emergency exists when a child with a birth defect is born and responsive thoughtful action including family counseling can significantly alter the life of the patient and his family.

Adrenal Hyperplasia, Congenital↗
PubMedDate not supplied

Apolipoprotein profile in type II diabetic patients with and without coronary heart disease.

Diabetes mellitus is frequently associated with lipid metabolism abnormalities. In the present study the lipid and apolipoprotein profiles have been compared in type II diabetic subjects with (n = 30) and without (n = 30) coronary heart disease (CHD). All subjects were studied after good metabolic control had been achieved. Significant differences in plasma lipids and apolipoproteins were seen in diabetic patients with CHD in comparison with diabetics without CHD. Patients with CHD presented higher total cholesterol, triglyceride, LDL-cholesterol, apo B, apo CII and apo CIII levels and total cholesterol/HDL-cholesterol and LDL-cholesterol HDL-cholesterol ratios and lower HDL-cholesterol values and apo A1/apo B ratio than the patients without CHD. The same findings were found in females; while male subjects with CHD had significantly increased total cholesterol, LDL-cholesterol and apo B levels and total cholesterol/HDL-cholesterol and LDL-cholesterol/HDL-cholesterol ratios and significantly decreased apo A1/apo B ratio compared with males without CHD. These findings support the concept that the apolipoprotein profile plays a remarkable role as risk factor for CHD in type II diabetes mellitus.

Aged↗
PubMedDate not supplied

Thrombin-antithrombin III complexes in type II diabetes mellitus.

Several studies suggest that diabetes is associated with a hypercoagulable state. Therefore determination of thrombin-antithrombin complex (TAT) could represent a sensitive parameter for specific detection of a latent activation of the clotting system. The present study documents increased plasma TAT in a heterogeneous group of non-insulin-dependent diabetic patients. The finding of increased TAT levels both in diabetic patients with vascular complications and in vascular disease patients without diabetes suggests a relationship between existing vascular disease and the hemostatic mechanism that produces augmented thrombin activity. In acute vascular occlusions the presence of diabetes seems to increase activation of the coagulative system.

Adult↗
PubMedDate not supplied

Cytogenetic analysis using telemedicine consultation: an improved means of providing expert cross-coverage.

PURPOSE: We used telemedicine in providing cross-coverage for a clinical cytogenetics laboratory. A genetic teleconsultation system was used to provide expert cross-coverage for a laboratory in a neighboring metropolitan region for a 6 month period while the usual provider of these services was on military reserve duty. METHODS: The teleconsultation system was a commercially available Perceptive Scientific Instruments (PSI) workstation. Five hundred thirty-nine cytogenetic cases were performed during the study period in the home laboratory in Baltimore, Maryland. RESULTS: Karyotypes and supporting metaphase spreads were transmitted by modem to the covering director, whereas work sheets and reports were faxed. Physical transfer of data was not necessary, and turn-around-time was not increased. CONCLUSION: This ability to employ a remote part time director has significant benefits for the laboratory with an absentee director for short or even extended periods of time. We conclude that the use of telemedicine in clinical cytogenetics proved to be an efficient and a cost effective means of providing genetics services to a region during a time of cross-coverage need.

Chromosome Aberrations↗