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Biomedical subjects

M Zamboni

Publications and source records attributed to M Zamboni.

102 records · Page 6Linked to original sources
PubMed1980

[Supervision of the postoperative period in biliary shunt operations: validity of sequential hepato-biliary scintiphotography with 99mTc-HIDA].

The Authors' aim was to assess the effectiveness of Sequential Scintiphotography of the Liver with 99mTc-HIDA (SSFH) in the evaluation of post operative jaundice, in operations of biliary derivation (43 observations in 28 patients). SSFH proved to be highly reliable even in comparison with more laborious procedures (such as Transhepatic Cholangiography), and superior to equally simple procedures such as Echo Tomography and Computerised Tomography, evidencing itself as the investigation of choice for the study of this pathology, especially in long-term follow-ups.

Bile Ducts↗
PubMed1979

Evaluation of the scintigraphic technique for detecting bone metastases in 100 breast cancer patients.

In an attempt to evaluate the utility of bone scintigraphy for the diagnosis and follow-up of skeletal metastases, radioisotopic scan (total body) by 99mTc has been performed on 100 patients suffering from breast cancer in various stages. The radiographic control followed the scan on the basis of clinical or scintigraphic suspicion of bone lesions. Twenty-one patients showed metastases by scan, and in all but 2 the radiography was concordantly positive; in 22 subjects scintigraphy and radiology demonstrated non-malignant lesions. Both scan and radiology were used to explore 169 metastatic localizations, with concordant results in 45% of the sites; however, 7% of the sites with discordant results became positive for metastasis by radiology some months after the scan positivity. The false-negative results were more frequent in the radiographic study (27%) than with the scintigraphic scan (21%). The latter technique was unable to detect osteoblastic lesions in particular. The scintigraphic test also gave reliable results in the follow-up procedure, frequently anticipating the radiological modifications of metastatic lesions. In conclusion, bone scan often appears to be more accurate and preocious than the roentgengraphic test in the detection and the follow-up of skeletal metastatic lesions; it suggests the utility of the bone scan as a preliminary test, which allows a more rational use of the radiology.

Bone Neoplasms↗
PubMed1978

Effect of modeccin on the steps of peptide-chain elongation.

Modeccin inhibits polypeptide-chain elongation catalysed by Artemia salina (brine shrimp) ribosomes by inactivating the 60 S ribosomal subunit. Among the individual steps of elongation, peptide-bond formation, catalysed by 60 S peptidyltransferase, is unaffected by the toxin, whereas the binding of EF 2 (elongation factor 2) to ribosomes is strongly inhibited. Modeccin does not affect the poly(U)-dependent non-enzymic binding of either deacylated tRNAPhe or phenylalanyl-tRNA to ribosomes. The inhibitory effect of modeccin on the EF 1 (elongation factor 1)-dependent binding of phenylalanyl-tRNA is discussed, since it is decreased by tRNAPhe, which stimulates the binding reaction. The analysis of the distribution of ribosome-bound radioactivity during protein synthesis shows that modeccin consistently inhibits the radioactivity bound as long-chain peptides, but depending on the experimental conditions, can leave unchanged or even greatly stimulates the radioactivity bound as phenylalanyl-tRNA and/or short-chain peptides. It is concluded that, during the complete elongation cycle, modeccin does not affect the binding of the first aminoacyl-tRNA to ribosomes, but inhibits some step in the subsequent repetitive activity of either EF 1 or EF 2. The results obtained indicate that the mechanism of action of modeccin is very similar to that of ricin and related plant toxins such as abrin and crotin.

Animals↗
PubMedDate not supplied

99mTc-Ca-gluconate renal scintigraphy in patients with chronic renal failure.

From use of 99mTc-Ca-Sn-gluconate in patients with various degrees of renal failure the following conclusions were drawn: 1. a good relationship exists between the parenchymal and vascular patterns in scintigraphy and the functional renal impairment; 2. the morphological definition is good, since in most cases a differential diagnosis can be made between diffuse parenchymal disease and space-occupying lesions even very low glomerular filtration rate values; 3. this technique is supplementary to i.v. pyelography in patients with relatively good glomerular filtration rate values and is a reliable alternative to i.v. pyelography in those with low creatinine clearance values.

Calcium Gluconate↗
PubMedDate not supplied

Rapid steroid taper and neoral monotherapy in liver transplantation in Chile: a step in the right direction?

UNLABELLED: Diabetes, hypercholesterolemia, hypertension, obesity, osteopenia, and increased risk of viral recurrence are among the complications associated with posttransplant steroid use. Steroid withdrawal or rapid taper has been reported to be safe. The aim of this study was to compare the rejection incidence and severity among patients treated with two different steroid taper strategies. METHODS: This retrospective study included all the adult liver transplant recipients since the program's inception from 1993 to January 2002. The minimum follow-up was 1 year. Exclusions included patients receiving an immunosupressive regimen other than mycophenolate mofetil, steroids, and Neoral, or suffering an autoimmune etiology, or displaying patient or graft survival less than 1 year. The incidence and severity of rejection episodes were compared between the two groups of steroid taper protocols: group A received methylprednisolone (1 g) intraoperatively with a slow taper to 10 mg prednisone per day at 1 year. Group B received methylprednisolone (2 g) intraoperatively followed by a rapid reduction with intention to withdraw by month 4, continuing on Neoral monotherapy. Rejection diagnosis was made on histological bases. RESULTS: One-month and 1-year rejection rates were 47% and 53%, respectively, among the rapid taper group with Neoral monotherapy, which was similar to 60% and 64%, respectively, in the slow taper group. Rejection severity was also comparable between the two groups. CONCLUSIONS: Patients treated with a rapid steroid taper protocol followed by Neoral monotherapy or a slow taper protocol showed similar acute rejection incidences and severities. Their survival rates were also comparable. Further study is necessary to evaluate the impact of rapid steroid taper to prevent the complications of steroid use.

Adrenal Cortex Hormones↗
PubMedDate not supplied

[Mycobacterium szulgai infection in a patient with hemophilia and AIDS].

Mycobacterium szulgai is a scotochromogenic species recently recognized as a human pathogen. Twenty-nine cases of disease caused by M. szulgai in humans have been reported. Pulmonary disease indistinguishable from that caused by M. tuberculosis was the commonest type of infection caused by M. szulgai. Olecranon bursitis was reported in 3 cases and disseminated infection was noted in 3 cases occurring in immunocompromised patients without AIDS. The authors report the first case of pulmonary disease caused by M. szulgai in Brazil and the first case in patient with AIDS in the world literature.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

[Value of echography in the measurement of changes in the total and visceral adipose mass].

Various methods to assess lean and fat body masses and abdominal-visceral adipose tissue were compared in 26 obese women on extremely hypocaloric diets. The following anthropometric parameters were measured before and after 15 days of extreme calorie restriction: arm circumference (A), waist circumference (W), hip circumference (H) and thigh circumference (T); W/H, W/T, A/H and A/T ratios; subcutaneous biceps , triceps , subscapular, abdominal and thigh folds; echographic thickness of abdominal muscle-aorta; area of visceral (VAT), total (AT) and subcutaneous adipose tissue measured using computed tomography, lean and fat body masses assessed by impedance measurement. Under standard conditions it was shown that echography, like impedance measurement, was the most useful method for assessing lean and fat body masses in obese subjects, whereas plicometry was not found reliable. On extremely hypocaloric diets, echography is able to assess the variations of lean and fat body masses, whereas impedance measurement overestimated the lean body mass. Localisation indexes of visceral fat based on body circumferences were shown not to be suitable for the evaluation of changes in visceral adipose tissue, at least when these were slight. Echography was also the most useful method to assess slight changes in visceral adipose tissue.

Adipose Tissue↗
PubMedDate not supplied

Interaction of gelonin with zinc.

Gelonin, a plant protein which inactivates eukaryotic ribosomes, binds to zinc chelate Sepharose from which it is eluted with EDTA or histidine. After purification by metal chelate affinity chromatography, gelonin maintains the associated zinc-dependent proteinase activity previously described. In equilibrium dialysis about 4 moles of zinc bind per mole of gelonin with a dissociation constant of 0.96 mM. Ca2+ behaves as a mixed competitive and non-competitive inhibitor of the binding of zinc with Ki = 29 mM.

Calcium↗
PubMedDate not supplied

A metalloproteinase associated with gelonin, a "ribosome inactivating protein".

Gelonin, a single-chain protein which inactivates eukaryotic ribosomes, becomes split into peptides when incubated with SDS. During the chromatographic purification of gelonin on carboxymethylcellulose three overlapping peaks emerge in the gelonin elution region, containing three proteins with small differences in apparent molecular weight (31,500, 30,000 and 29,200). All three proteins are endowed with inhibitory activity on protein synthesis and with proteinase activity, although with different specific activities, and all three give rise to the same peptides upon incubation with SDS, suggesting that they are isoforms of gelonin. The gelonin-associated proteinase acts only on gelonin, while it is inactive on the most common substrates for endoproteinases. The proteolytic activity is not inhibited by inhibitors of serine- or SH-proteinases, while it is completely abolished by chelating agents. Divalent cations restore the proteolytic activity inhibited by EDTA. The stability of the proteinase activity on exposure of gelonin to extreme values of pH or to prolonged incubation has been investigated. The inhibitory activity on protein synthesis and the proteinase activity are differently affected by these treatments.

Animals↗