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Biomedical subjects

M Ramos

Publications and source records attributed to M Ramos.

At least 19 recordsLinked to original sources

Rapid analysis of whey proteins from different animal species by reversed-phase high-performance liquid chromatography.

This paper explores the possibilities of reversed-phase high performance liquid chromatography (RP-HPLC) for analysing whey proteins from the milk of cows and other animal species. An RP-HPLC method is proposed to separate and quantify bovine whey proteins. Using this method, bovine serum albumin, alpha-lactalbumin, beta-lactoglobulin A and beta-lactoglobulin B were separated in less than 7 min. It is demonstrated that irreversible adsorption of bovine whey proteins occurs on unused columns (i.e. those not previously used to separate proteins). Therefore, prior conditioning of the column with whey proteins is required for valid protein quantification. Conditioning can be achieved by eluting a large amount of at least one of the bovine whey proteins through the unused column. The calibration curve (peak area vs. protein concentration) for the main bovine whey proteins was linear. This method also allowed good separation of caprine and ovine whey proteins and separation of some homologous whey proteins of different animal species. Detection of milk mixtures from different animal species was carried out using this method.

Animals

Chondroitinases release acetylcholinesterase from chick skeletal muscle.

Bacterial chondroitinases (both ABC and AC types) release asymmetric and globular forms of AChE from chick skeletal muscle samples. Heparinases, however, including heparitinase I, fail to do so under different incubation conditions. These results do not support the direct implication of the heparin/heparan sulfate family of GAGs in the interaction of the different AChE molecular forms with the muscle ECM. GAGs of the chondroitin/dermatan sulfate group could however be involved, either directly or indirectly, in the attachment of the AChE collagen-like tail to the muscle basal lamina.

Acetylcholinesterase

Solubilization of asymmetric acetylcholinesterase by polyanions.

A number of polyanions, including polysulfates (sulfated glycosaminoglycans (GAGs), dextran and pentosan sulfates, and polyvinylsulfate), polyphosphates (tetrapolyphosphate, polyadenylate) and polycarboxylates (polyaspartate, polyglutamate) solubilize asymmetric acetylcholinesterase (AChE) from chick muscle at low ionic strength, and partially or totally displace AChE tailed forms bound to heparin-agarose columns. The previously reported solubilization of asymmetric AChE by heparin, or the proven affinity of the tailed enzyme forms for this GAG, cannot therefore be taken as direct proof of the involvement of heparin-like heparan sulfate proteoglycans in the anchorage of the collagenous tail of the enzyme to the basal lamina in skeletal muscle.

Acetylcholinesterase

Proteolytic activity of two commercial proteinases from Aspergillus oryzae and Bacillus subtilis on ovine and bovine caseins.

Electrophoretic analysis of the action of two commercial enzymes, Neutrase 0.5 and MKC Fungal Protease, on whole casein and alpha s-, beta- and kappa-caseins from cows' and ewes' milk showed that Neutrase 0.5 chiefly degraded beta-casein, giving rise to peptides soluble at pH 4.6 detectable by PAGE. In contrast, although MKC Fungal Protease caused intense hydrolysis of bovine beta-casein, in ovine casein it resulted in more active degradation of alpha s- than beta-casein. The latter enzyme did not produce peptides soluble at pH 4.6 detectable by PAGE. Both enzymes degraded kappa-casein, yielding a breakdown product that exhibited an electrophoretic mobility similar to that of the breakdown product produced by the action of commercial rennet.

Animals

Gas-liquid chromatographic analysis of cellular fatty acids for identification of gram-negative anaerobic bacilli.

A commercially available, computer-assisted microbial identification system (MIS) employs gas-liquid chromatographic analysis of cellular fatty acids for bacterial identification. MIS was compared with conventional identification systems. Of 225 gram-negative anaerobes tested, MIS identified 72.4% of the strains to the species level, 88.9% to the appropriate group, and 93.3% to the correct genus.

Bacteriological Techniques

Asymmetric acetylcholinesterase is absent from chick retina, but present in choroid, ciliary muscles and iris.

Freshly dissected chick neural retina and pigmented epithelium do not apparently contain asymmetric molecular forms (A-forms) of acetylcholinesterase (AChE). The neighboring choroid, and the ciliary muscles and iris, are however rich in type II A-forms (high salt/EDTA-extractable). Most if not all the asymmetric AChE activity detected in chick 'whole retina' preparations could then be explained in terms of contamination by non-retinal eye tissues.

Acetylcholinesterase

[Utility of myocardial scintigraphy with Tc-99m methoxy-isobutyl-isonitrile in the diagnosis of coronary disease].

We have studied 24 patients (21 males and 3 females) with coronary artery disease. Stress and rest myocardial scintigraphy was performed in all cases with 15-20 mCi of Tc99m methoxy-isobutyl-isonitrile. The examination was done in 2 sessions. Usually the stress scan was obtained and within 2-4 days the rest study was obtained. All patients underwent selective coronary arteriography within a week of the scintigraphy and, in 13 cases, rest radiologic ventriculography was also performed. In 5 patients coronary arteriography and myocardial scintigraphy were normal. In 19 cases the coronary arteriography showed lesions, the myocardial scintigraphy showed ischemia or necrosis in 17 of them and was normal in two. To localize the pathologic vessel the myocardium was divided into 3 segments and segmentary analysis localized the abnormal coronary artery in 51 out of 72 cases. The best availability of the new myocardial agent and the results obtained make it a good tracer for myocardial studies.

Adult

The effects of chondroitinase ABC on the rabbit intervertebral disc. A roentgenographic and histologic study.

A series of intradiscal injections of chondroitinase ABC was performed in 31 young adult rabbits. Roentgenograms were taken immediately postinjection and were repeated at two, three, five, six, seven, or nine days after injection. All had roentgenographic evidence of disc space narrowing at all stages after the injection. Histologic evaluation of safranin-O fast green-stained sections indicated degradation of proteoglycans in the annulus fibrosus of chondroitinase ABC-injected discs. The cells of the chondroitinase ABC-injected discs, the end plates, and the growth-plate areas of adjacent vertebral bodies appeared unaffected.

Animals

[Gammagraphy with 111In-labelled leukocytes in an acute outbreak of inflammatory intestinal disease. Evaluation of the localization, extension and degree of activity].

We have studied 59 patients suspected of presenting an acute bout of inflammatory bowel disease: 23 had Crohn's disease and 36 had ulcerative colitis. All them underwent scintigraphic examination using 111In labelled leukocytes during the first 72 hours after their admittance and in a period no longer than 30 days, they also underwent barium enema and/or endoscopic study. Scintigraphic examination was more sensitive (100%), specific (100%) and accurate (100%) than endoscopy (72%, 100% and 78%) and barium enema (69%, 80% and 71%) in Crohn's disease. In ulcerative colitis, although endoscopy (100%) was slightly more sensitive than scintigraphy (100% and 94% against 78% and 93%). Reliability of barium enema was always lower to that of scintigraphy. In both conditions, scintigraphic examination detected a higher number of affected segments than barium enema did (40/16 in Crohn's disease and 65/31 in ulcerative colitis). Correlation between the index of scintigraphic activity and Harvey's index of clinical and biologic activity was highly significant (p less than 0.001) in both diseases. We conclude that scintigraphic examination using 111In labelled leukocytes is a reliable examination method for evaluation of localization, extension, and degree of activity of inflammatory bowel disease and that it must be a part of the examination protocol.

Acute Disease

[Autonomic function in uremia and diabetes mellitus].

Autonomic function was evaluated in three groups of patients: diabetics, nondiabetic uremics, and uremic nondiabetics. Autonomic function was assessed with a parasympathetic function test (Valsalva maneuver) and two sympathetic function tests (cold and amyl nitrite). The results showed that all groups of patients, as compared with healthy controls, had a dysfunction of the autonomic nervous system (ANS). This ANS involvement, both in the parasympathetic and the sympathetic divisions, was much more severe in those patients with simultaneous uremia and diabetes.

Adult

[Very late recurrence (14 years) of a lymphoblastic leukemia-lymphoma].

We report a two and a half years old girl diagnosed in 1972 of lymphoblastic leukemia-lymphoma with pleural, mediastinal and bone marrow involvement. Clinical remission developed with chemotherapy (induction and maintenance). This situation persisted until June 1986 (14 years after the diagnosis and 11 years after cessation of any therapy), when mediastinal mass, pleural effusion and bilateral renal infiltration developed again, and also peripheral lymphadenopathy; bone marrow involvement is now absent. This case is considered as an exceptionally late relapse. Other possibilities are discussed, while the difficulty to define "cure" in these patients is emphasized.

Antineoplastic Combined Chemotherapy Protocols

Comparative studies on "acid-stable, heat-stable polypeptides" of ovine, caprine and bovine milks.

"Acid-stable, heat-stable polypeptides" (previously called proteose-peptone) of three milk species have been studied. Analysis by polyacrylamide gel electrophoresis revealed that all fractions showed similar patterns. Only bands with the lowest mobilities showed the presence of carbohydrates when stained with Schiff's reagent. These bands had a lower mobility in ewe's and goat's milk than in cow's milk. Gas chromatography/mass spectrometry analysis showed the presence of fucose, mannose, glucose, galactose, glucosamine and galactosamine in the three fractions studied. Acid-stable, heat-stable polypeptides of bovine milk had the lowest carbohydrate content (4 mg/100 mg protein), whereas the highest content was found in ewe's milk (7.30 mg/100 mg protein) mainly as a result of the high galactose, mannose and glucosamine content. The sialic acid content was lower in ewe's and goat's milk (2.68 and 2.98 mg/100 mg protein respectively) than in bovine milk (2.06 mg/100 mg protein).

Animals

Calculation of portal contribution to hepatic blood flow with 99mTc-microcolloids. A noninvasive method to diagnose liver graft rejection.

The portal contribution (PC) to hepatic blood flow was calculated in 13 liver graft patients and 13 normal volunteers. The method is based on the quantification and normalization of the liver and spleen activity after the administration of 7 mCi (259 MBq) of 99mTc microcolloid. Forty examinations were performed in liver grafts and 13 in normal subjects. The PC was significantly higher in normal native liver (64.0 +/- 3.0%) than in functioning grafts (58.8 +/- 3.1%). In acutely rejecting patients, PC was significantly lower (52.4 +/- 2.0%) than in functioning grafts and similar to that observed in cholangitis (53.5 +/- 0.7%). The PC increases again once rejection has resolved (57.3 +/- 2.6%). During hepatitis post-transplant PC values (59.7 +/- 3.4%) were similar to those observed in functioning grafts. Overall, PC values over 55% are very unlikely to be due to rejection.

Adult