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Biomedical subjects

M Ramos

Publications and source records attributed to M Ramos.

At least 127 records · Page 7Linked to original sources
PubMed1994

Gas-liquid chromatography of cellular fatty acids for identification of staphylococci.

A commercially available, computer-assisted microbial identification system (MIS) employs gas-liquid chromatographic analyses of bacterial fatty acids. The MIS was used to identify 470 isolates of Staphylococcus species. The accuracy of the MIS was compared with the accuracies of conventional methods. There was a complete agreement between the MIS and conventional methods in the identification of 413 (87.8%) strains. For 36 of 45 misidentified strains, the correct identification was listed by the MIS as a choice but not as the first choice. Twelve strains could not be matched. All strains of Staphylococcus cohnii, S. epidermidis, S. intermedius, S. lugdunensis, S. schleiferi, S. sciuri, S. simulans, and S. xylosus were correctly identified. Two species, S. hominis and S. saprophyticus, accounted for 52.6% (30 of 57) of the misidentifications. Seventy-eight organisms were retested. Identification of 73 organisms remained unchanged, and for five organisms, the second choice became first and vice versa. The overall performance of the MIS is acceptable, and the system can be used as an alternate identification method for staphylococci.

Chromatography, Gas↗
PubMed1994

Diminished virulence of a sar-/agr- mutant of Staphylococcus aureus in the rabbit model of endocarditis.

Microbial pathogenicity in Staphylococcus aureus is a complex process involving a number of virulence genes that are regulated by global regulatory systems including sar and agr. To evaluate the roles of these two loci in virulence, we constructed sar-/agr- mutants of strains RN6390 and RN450 and compared their phenotypic profiles to the corresponding single sar- and agr- mutants and parents. The secretion of all hemolysins was absent in the sar-/agr- mutants while residual beta-hemolysin activity remained in single agr- mutants. The fibronectin binding capacity was significantly diminished in both single sar- mutants and double mutants when compared with parents while the reduction in fibrinogen binding capacity in the double mutants was modest. In the rabbit endocarditis model, there was a significant decrease in both infectivity rates and intravegetation bacterial densities with the double mutant as compared to the parent (RN6390) at 10(3)-10(6) CFU inocula despite comparable levels of early bacteremia among various challenge groups. Notably, fewer bacteria in the double mutant group adhered to valvular vegetations at 30 min after challenge (10(6) CFU) than the parent group. These studies suggest that both the sar and agr loci are involved in initial valvular adherence, intravegetation persistence and multiplication of S. aureus in endocarditis.

Animals↗
PubMed1994

[Inflammatory pseudo tumor of the bladder (in a 6-month-old girl)].

We describe the clinical case of a six-month old female child, who presented an intra-vesical mass as a sequence of urinary tract infection. After surgical resection the histopathological study was consistent with the diagnosis of inflammatory pseudotumor of the bladder.

Cystitis↗
PubMed1994

[S. pneumoniae sternoclavicular arthritis in a patient with HIV infection].

HIV infection is a predisposing factor for pneumococcic infection. While pneumonia is the most frequent location, other locations (articular, meningeal, endocardiac, etc) have been less frequently described. Among the articular infections described in patients with HIV infection, the sternoclavicular affection is extremely rare and it usually develops in association with parenterally drug addiction, being Staphylococcus aureus and Pseudomonas aeruginosa the most frequently germs involved. We describe the first case of sternoclavicular arthritis by Streptococcus pneumoniae in a patient with HIV infection. In our case, the chronic hepatopathy associated to alcohol consumption is a predisposing factor related to the pneumococcic infection. Our case suggests the need to formally investigate the HIV infection in young patients with invasive pneumococcic infection.

Adult↗
PubMed1994

[Sjögren's syndrome].

This paper consists the theorical review and the current concepts of the subject and the second includes the casuistry of the Stomatology Department of the Pulido Valente Hospital. From April 1989 to 1991 (2 years), a study was made on Sjögren Syndrome (Primary and Secondary) of multiple character with the particular co-operation of the Portuguese Institute of Rheumatology. With this paper we wish to point out the importance of the oral evaluation of the study of the plurisystemic diseases as well as to establish criterions of diagnosis for the Portuguese population. Eighty cases of suspected Sjögren's Syndrome have been assessed, 66 of which have been fully. The reason for the consultation was dry mouth, dry eyes and enlargement of parotid glands. The symptoms were isolated or in association with other pathologies after other causes had been excluded. We had to establish the salivary reference values for the Portuguese population in 22 healthy volunteers. The xerostomia was evaluated by the Sialochemistry, Sialography, Cintigraphy and biopsies of the lower lip and of the sublingual gland. The ophthalmologic examination took place in the Ophthalmology Department of Santo António dos Capuchos Hospital by means of Shirmer test, Rosa Bengala and B.U.T. In spite of Sjögren's Syndrome being, up to now, so remotely determined in connection with the treatment, these patients need medical care and Stomatology plays a fundamental role as far as the diagnosis and the therapeutic points of view are concerned. We maintain the notion that the Syndrome is not as infrequent as one would believe and the evaluation of the oral field is important to establish the degree of the disease and its treatment.

Female↗
PubMed1994

Chromosome 17 abnormalities and TP53 mutations in adult soft tissue sarcomas.

This study was designed to determine the frequency of structural genetic abnormalities of chromosome 17 and the incidence of TP53 mutations as they relate to the biological behavior of adult soft tissue sarcomas. We analyzed a group of 73 soft tissue sarcomas of adults that were clinically and pathologically well characterized using molecular genetic techniques and expression studies. We then correlated genotype and phenotype with pathological parameters. Overall, allelic loss of 17p and 17q was identified in 53 and 29% of informative cases, respectively. p53 nuclear overexpression was detected in 34% of the tumors analyzed. We observed an association between 17p deletions and tumor presentation being more frequent in recurrent and metastatic tumors than primary lesion. p53 nuclear overexpression was associated with tumor grade, size, and more frequently detected in metastatic than primary sarcomas. The 11 intragenic mutations characterized included 10 cases of single base substitution and one single base deletion; 8 were of the missense type and 3 were nonsense. It is concluded that 17p deletions and TP53 mutations are common events in adult soft tissue sarcomas and that due to the trends observed with the cohort of patients analyzed they may become prognostic markers for patients affected with these tumors.

Alleles↗
PubMed1994

Identification of main risk factors for tubal infertility.

OBJECTIVE: To determine the relationship between some reproductive variables and infertility caused by tubal obstruction. DESIGN: A retrospective, case-control study. SETTING: A tertiary care university hospital that is a referral center for infertility patients. PARTICIPANTS: Subjects were interviewed between March 1990 and December 1991. Cases were 215 consecutively recruited infertile women with either evidence of tubal obstruction found at laparoscopy or hydrosalpinx diagnosed by hysterosalpingography. Women with a history of surgical sterilization were excluded. Controls, selected in the same hospital, were women in the puerperium who had no history of infertility. Two controls were matched by age at the time of tubal obstruction diagnosis to each case. RESULTS: History of pelvic surgery and use of alcohol were significantly associated with the risk of infertility caused by tubal obstruction. The use of barrier, oral, and medroxyprogesterone acetate (MPA) contraceptives was associated with a protective effect. When only women with secondary infertility were analyzed, history of pelvic surgery and number of lifetime sexual partners were significant risk factors, and the previous use of oral contraceptives was the only protective factor. CONCLUSIONS: History of pelvic surgery was the most important risk factor for tubal infertility. All precautions must be taken to avoid infection and adhesion formation when pelvic surgery is performed. In addition, women can be protected from tubal infertility by using barrier, oral, or MPA contraceptive methods.

Adult↗
PubMed1993

New assay for the rapid determination of plasma holotranscobalamin II levels: preliminary evaluation in cancer patients.

We describe a new and rapid assay for the measurement of plasma B12 bound to transcobalamin II (holotranscobalamin II) using the property of adsorption of the polypeptides of apotranscobalamin II and holotranscobalamin II to the hydrophobic surface of microfine glass particles. Acid-washed microfine glass was used to separate vitamin B12 bound to the glycoproteins transcobalamin I and transcobalamin III (haptocorrin or R binder) from that bound to transcobalamin II. Sephadex gel filtration separation of 57Co-labelled vitamin B12 binders confirmed that > 90% of holotranscobalamin II can be removed from plasma holohaptocorrin by adsorption to microfine glass particles. Since only holotranscobalamin II is capable of delivering vitamin B12 to metabolizing cells, plasma holotranscobalamin II content reflects the availability of B12 to cells. Use of this test in cancer patients undergoing either chemotherapy or radiation therapy revealed evidence of early negative B12 balance that in some instances was induced by the treatment itself.

Adsorption↗
PubMed1993

Measurement of red blood cell-vitamin B12: a study of the correlation between intracellular B12 content and concentrations of plasma holotranscobalamin II.

We have recently reported a new and rapid assay to measure plasma holotranscobalamin II (holo TC II) as a means of exploring vitamin B12 status. In order to further evaluate the significance of plasma holoTC II in determining tissue cobalamin, we have chosen the red blood cell-vitamin B12 (RBC-B12) assay as a measure of tissue vitamin B12 content and studied the relationship between RBC-B12 and plasma holoTC II levels. Plasma holoTC II and RBC-B12 concentrations were concomitantly assayed in 20 hematologically normal controls and cancer patients. In our groups of controls, the mean value of RBC-B12 was determined as 241 +/- 51 pg/ml of packed erythrocytes (PE) with a range varying from 180 to 355 pg/ml PE. Preliminary results obtained in 32 cancer patients revealed lower holoTC II and RBC-B12 levels than the control group and a required threshold value of 70 pg/ml of holoTC II in order to maintain a normal RBC-B12 greater than 180 pg/ml PE.

Erythrocytes↗
PubMed1993

[Effects of postoperative autotransfusion in prosthetic surgery of the hip with the ConstaVac device].

A new device for postoperative autotransfusion (ConstaVac, Stryker) was assessed after total hip replacement in 43 patients, mean age 63 +/- 13 years. Intraoperative blood was administered to 27 patients (63%), autologous blood only in 19, homologous blood only in 6 and both autologous and homologous blood in 2. The blood shed during an average 5-hour postoperative period had an haematocrit of 23 +/- 7% and included only few platelets (72 +/- 83 G.l-1). It did not clot as it contained there was less than 0.1 g.l-1 of fibrinogen and a high concentration of D-dimers. In 30 patients (70%), the amount of blood thus collected exceeded 200 ml. An average of 327 +/- 131 ml were subsequently retransfused to these patients. Postoperative autotransfusion induced a moderate but significant decrease in platelet counts (205 +/- 66 vs. 224 +/- 67 G.l-1, p < 0.02) and fibrinogen concentrations (2.3 +/- 0.7 vs. 2.4 +/- 0.6 g.l-1, p < 0.03), and an increase in circulating D-dimers (p < 0.001). Coagulation tests, free plasma haemoglobin and potassium concentrations were not significantly altered. Since the haematocrit of the blood lost was lower than that of the patients', the haematocrit did not increase significantly. Posttransfusion shivering occurred in two patients (7%). Bacteriological cultures of the lost blood and of venous samples obtained after postoperative autotransfusion remained sterile. Postoperative autotransfusion is a simple technique with few side-effects, which might be safely associated with other methods used to decrease the rate of homologous blood transfusion.

Adult↗
PubMed1993

Proteolysis during storage of UHT milk: differences between whole and skim milk.

Proteolysis during storage of UHT skim and whole milks processed by either direct or indirect systems has been studied. All the proteolysis indices determined (measurement of free amino groups, PAGE of caseins and PAGE and reversed-phase HPLC of the fraction soluble at pH 4.6) revealed greater proteolytic degradation during storage of skim milks compared with that of whole milks subjected to the same UHT treatments. Increased activities of both native milk proteinase and proteinases of bacterial origin were observed in skim UHT milks. The different behaviour of UHT skim and whole milks on storage would have to be taken into account in establishing the process conditions.

Animals↗
PubMed1993

Discovery of an ovine alpha S2-casein variant.

A novel ovine alpha S2-casein variant has been detected using discontinuous polyacrylamide gel electrophoresis at alkaline pH, two dimensional electrophoresis and immunoblotting. It is characterized by a greater negative net charge and a lower isoelectric point compared with the most common ovine alpha S2-casein variant. The phenotypic frequency in the Manchega breed is 5.5%.

Animals↗
PubMed1992

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↗