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Biomedical subjects

C Calvo

Publications and source records attributed to C Calvo.

At least 109 records · Page 6Linked to original sources
PubMed1977

[Renal venous thrombosis in infants of diabetic mothers (author's transl)].

Six cases of renal venous thrombosis in infants of diabetic mothers, out of a series of 61 infants under two months old affected of R.V.T. (9.8%), are reported. The clinical, metabolic and histopathological features of these cases are discussed, as well as the different etiological theories that exist in the literature. An etiopathogenic hypothesis that maintains a similarity with the theory that explains the origin of R.V.T. in classical cases, is suggested. Prophilactic attitudes in order to prevent R.V.T. by a control of diabetes in the pregnant and close control of the newborn in the 10 first days of life, are pointed out.

Female↗
PubMed1977

[Idiopathic hematuria in childhood (author's transl)].

Idiopathic hematuria is a clinical condition of unknown etiology; it is defined as persistent or recurrent, macro or microscopic hematuria in the absence of systemic or local disease and with normal renal function. Six patients who had these criterions were studied. There were all girls. The age of the first episode was between one and four years. There was no other family or personal history of renal disease or deafness. Only two patients had their episodes of macroscopic hematuria within flu-like illness or exercise. All had normal renal function and no proteinuria was found. Serum C'3 and C'4 were normal. Microscopic and immunofluorescence studies were negative. We remark the convenience of a triple criteria clinical, histopathologic and evolutive to select a patient into the "idiopathic hematuria" group. We comment the usefullness of renal biopsy in the investigation of unexplained hematuria.

Biopsy↗
PubMedDate not supplied

[Differentiation of Yersinia enterocolitica 0:3 and 0:9 by precipitation of CaCO3 at 37 degrees C].

Precipitation of CaCO3 by different Yersinia strains on B-4 agar at 25 and 37 degrees C was studied. The 185 Yersinia strains examined produced crystals at 25 degrees C, but only 121 strains produced crystal at 37 degrees C. Strains of serotype 0:9 produced crystals at 37 degrees C, whereas strains of serotype 0:3 failed to do so. The calcium carbonate precipitation test at 37 degrees C should enable a differentiation between the two serotypes incriminated in human pathology in Europe.

Calcium Carbonate↗
PubMedDate not supplied

[Rapid differentiation of the 0:3 and 0:9 serovars of Yersinia enterocolitica by certain bacteriophages].

The sensitivity of some phenotypes of Yersinia to 7 phages isolated from lysogenic strains of Y. frederiksenii, Y. kristensenii and Y. intermedia was investigated. Among the strains involved in human pathology in Europe, Y. enterocolitica serovar O:3 was sensitive to 7 phages tested, while serovar O:9 was sensitive to all but one phage. Strains isolated from the environment, considered as non-pathogenic, were much less susceptible to the 7 phages. Based on these results, a new phage typing system which differentiates Y. enterocolitica O:3 and O:9 from the other Yersinia is proposed.

Bacteriophages↗
PubMedDate not supplied

In vitro susceptibility of Yersinia kristensenii strains to beta-lactam antibiotics.

The beta-lactam antibiotic susceptibility and beta-lactamase activity of 22 Yersinia kristensenii strains were determined in order to compare these properties with those reported for Y. enterocolitica. Carbenicillin, cephaloridine, cefoxitin and cefotaxime were the most active antimicrobial agents tested against Y. kristensenii. All strains were resistant to penicillin G, cephalothin, cephapirin and cephalexin. On the other hand, ampicillin and cefazolin activity could be considerated as intermediate. The influence of incubation temperature was also evaluated. All Y. kristensenii strains were more resistant at 22 degrees C than at 37 degrees C to beta-lactam antibiotics. Susceptibility to cefazolin was not affected by the incubation temperature. All Y. kristensenii strains produce beta-lactamase. The substrate profile of this enzyme is that of a cephalosporinase: its activity was highest on cephalothin, cephapirin, cephaloridine and cefazolin, while hydrolysis of ampicillin and carbenicillin was not detected. beta-Lactamase-resistant cefoxitin and cefotaxime were not hydrolysed. A correlation between beta-lactam antibiotic susceptibility and the hydrolysis rate of these antibiotics by beta-lactamase was observed, except for cephaloridine and cefazolin; these antibiotics were very good beta-lactamase substrates, but their MIC values were low.

Ampicillin↗
PubMedDate not supplied

Percutaneous endoscopic gastrostomy in head and neck cancer patients.

OBJECTIVE: To present our experience with the indications and complications of percutaneous endoscopic gastrostomy (PEG) in head and neck cancer patients. MATERIALS AND METHODS: In a retrospective study of the patients treated, we reviewed the records of 43 patients diagnosed with head and neck cancer at the Otorhinolaryngology Department, in which a PEG was performed by the Unit of Digestive Endoscopy. RESULTS: All cases had squamous cell carcinoma. Larynx was the most frequent primary site, with 21 cases (49%), followed by hypopharynx, 12 patients (28%). Indications for PEG were: dysphagia (53.5%) and pharyngocutaneous fistula (43.5%). The most frequent complication was a local infection. CONCLUSION: PEG is a good choice for long-term enteral feeding in head and neck cancer patients due to its low complication rate and easy handling.

Aged↗
PubMedDate not supplied

Hydatidosis in the province of La Pampa, Argentina, 1998.

Echinococcus granulosus is the agent that causes the classical hydatidosis or cystic echinococcosis. The most spread cycle in South America is the sheep-dog cycle, and offers favorable conditions for the development of the parasite. As the province of La Pampa shows an endemic presence with notification of cases and infected dogs, the present work has the aim of contributing to the study of the distribution and prevalence of the disease in the district of Maracó, La Pampa, Argentina. Dogs of 36 farms that had ovines, were dosed with arecoline hydrobromide at a dose of 3.5 mg/kg. Dogs from 27 (75%) farms resulted positive to Tenia sp. and 3 (8.3%) to E. granulosus. Blood samples were taken to all the people living in all the inquired farm and were processed by the ELISA test for hydatidosis. A retrospective survey on cases of human hydatidosis attended in the Hospital of General Pico, head if the sanitary region, and in two private clinics was performed. Analysis of clinical records indicated 11 cases operated during the period 1996/1997 (annual incidence rate of 6.8 per 100,000 inhabitants). It is of public health interest to fulfill epidemiologic investigations in other districts of the Province of La Pampa with the aim of delimitating the endemic distribution within the province and also organizing surveillance systems on human hydatidosis.

Adult↗
PubMedDate not supplied

[Immunological and inflammatory pathogenesis of asthma: the predominance of ontogenic Th2 and its relation to developing immunological mechanisms during fetal and neonatal stages. Therapeutic implications].

From an immunopathogenic vantage point, asthma appears to be a complex allergic/inflammatory disorder involving mechanism in which the specific immunological response shifts toward Th2 responses instead of Th1 responses. As a consequence of this shift, the cytokines IL-4, IL-5, IL-10, IL-13, TNF-alpha and CSF-GM are produced. The actions of these cytokines explain the phenomena of eosinophilic infiltration and mastocytic degranulation that characterize allergic asthma. The authors propose that the process of deviation toward Th2 responses occurs in the fetal stage and is a result of maternal immunological remodeling processes characteristics of pregnancy. In this period, the mother's mechanisms of immune rejection (mediated by Th1 lymphocytes and their cytokines IFN-gamma and IL-2) are detained or slowed, leading to the predominance of the Th-2 circuit. This predisposes the child to the development of an allergic response to a chance encounter with allergens, viruses and/or bacteria and/or parasites that activate the Th2 circuit. Moreover, deficits in the function of the Th1 circuit explain the sensitivity of the newborn to infections by viruses and other intracellular pathogens. Knowledge of these immunopathogenic mechanisms suggests that the future treatment of asthma and other allergic diseases will be based on the use of immunomodulators capable of stimulating Th1 response, thus achieving a) a god state of resistance to infection, and b) reductions of the production of pro-inflammatory cytokines. The experimental results of IL-12 in human beings with AM3 (an inductor of IFN-gamma and IL-12) support the pathogenic hypothesis proposed and open new ways for the treatment of asthma and other allergic diseases.

Asthma↗
PubMedDate not supplied

[Interaction of the mechanisms of beta 2-microglobulin convection, diffusion, and adsorption in line hemodiafiltration].

The in vivo contribution of diffusion, convection ad adsorption to beta 2-microglobulin (beta 2-m) elimination by hemodiafiltration (HDF) was investigated. 11 patients (8M/3W), with a mean age of 59 +/- 10 years and weighing 62.7 +/- 8.7 kg were studied. A 1.89 m2 polysulphone membrane was used in 180 min postdilution HDF. Samples at blood inlet (bi), blood autlet (bo), dialysate outlet (do) and ultrafiltrate (uf) were taken to determine beta 2-m concentrations at 30 and 150 min. Rates of flow (Q, ml(min) prescribed were: infusion, Qinf = 103.6 +/- 12.3, Quf = 14.6 +/- 4.0 y Qb = 465 +/- 5.0. Effective Qbi was automatically measured by the machine and Qdo = 800 + Quf. The removed beta 2-m mass (M, mg/min) was obtained by multiplying rates of flow (Q, L/min) by beta 2-m concentrations (mg/L) at each sampling point. From mass balance, we calculated the mass of beta 2-m removed (mg/min) by adsorption 0.23 +/- 0.2, by convection 0.7 +/- 0.3 and by diffusion 1.0 +/- 0.4, at 30 min. At 150 min, the beta 2-m mass removed was -0.06 +/- 0.1 by adsorption 0.4 +/- 0.1 by convection and 0.3 +/- 0.1 by diffusion. In HDF, these beta 2-m eliminating mechanisms play a variable role throughout the session. The more significant conclusion is that diffusion of beta 2-m with a synthetic "open" membrane is an important method of removing beta 2-m, comparable to convection over the whole procedure. That result explain the relative efficacy of beta 2-m clearance by HDF convection, and also explain why isolated diffusion is an efficient mechanism for beta 2-m removal by high-flux hemodialysis.

Female↗
PubMedDate not supplied

[Comparison of dialyzers in on-line hemodiafiltration].

UNLABELLED: At present we have a great variety of high-flux dialyzers whose characteristics in vitro seem similar. On-line HDF is a technique which combines diffusion with elevated convection and uses dialysate as replacement fluid. On-line HDF provides the highest clearances for small, medium-sized and large molecules and gives the best performance from the dialyzers. Conscious of this wide choice of dialyzers we evaluated the performance of different dialyzers in renowing small and medium-large molecules. Eleven patients were included in this study, 7 males and 4 females. Every patient received 11 on-line HDF sessions with Fresenius 4008B machine, Qi 100 ml/min or 6 L/h, QB 400 ml/min, QB 800 ml/min, UF 0.5 L/h and Td 60 min. Only the dialyzer was changed: 1.9 m2 cellulose triacetate (Tricea 190G), 2.1 m2 poly methyl methacrylate of PMMA (BK-2.1P), 1.8 m2 polyester-polymer Allol or PEPA (FLX-18GWS), 2.05 m2 acrylonitrile (Filtral 20), 2.1 m2 polyamide (Poliflux 2.1) and 1.8-2.4 m2 polysulfones (HF 80, BS-1.8S, APS-900, Arylane H9, Idemsa 2000, HdF 100). Arterial pressure, venous pressure and transmembrane pressure (TMP) were monitored. Plasma, urea, creatinine, phosphate, uric acid and beta 2m concentrations were measured at the beginning and at the end dialysis from arterial and venous blood lines, and arterial blood line with the slow flow method. Recirculation, dialyzer solutes clearance and solute reduction rates were calculated. No significant differences were found in arterial pressure, venous pressure and recirculation. Small molecule removal was similar except in BK-2.1P and HdF 100 dialyzers which were lower and higher respectively. There were differences in TMP and beta 2m removal among dialyzers employed. Mean TMP, beta 2m clearance and beta 2m reduction ratio were: Tricea 190G (TMP 336 mmHg, beta 2m K 79 ml/min and beta 2m reduction ratio 44.9%), BK-2.1P (TMP 485, beta 2m K 102 and beta 2mRR 48.3%), FLX-18 GWS (TMP 195, beta 2m K 140 and beta 2mRR 54.6%), Filtral 20 (TMP 245, beta 2m K 132 and beta 2mRR 54.1%), Poliflux 2.1 (TMP 209, beta 2m K 158 and beta 2mRR 56.0%), HF 80 (TMP 208, beta 2m K 160 and beta 2mRR 57.4%), BS-1.8S (TMP 186, beta 2m K 179 and beta 2mRR 59.6%), APS-900 (TMP 174, beta 2m K 176 and beta 2mRR 64.8%), Arylane H9 (TMP 206, beta 2m K 171 and beta 2mRR 59.9%), Idemsa 2000 (TMP 203, beta 2m K 169 and beta 2mRR 60.4%), HdF 100 (TMP 152, beta 2m K 186 and beta 2mRR 64.6%). CONCLUSIONS: Of the dialyzers evaluated in on-line HDF, cellulose triacetate and PMMA have a smaller beta 2m removal and their use is limited by an elevated TMP. The polysulfones provide greater beta 2m removal with lower TMP, particularly the APS-900 and HdF 100 dialyzers. The acrylonitrile, PEPA and polyamide are intermediate.

Equipment Design↗
PubMedDate not supplied

[Urinary tract infection in early infancy, study of 15 cases].

Urinary tract infection in the newborn shows peculiar characteristics not found in older children. 15 cases of urinary tract infection in infants aged 7 days to 2 months are presented. There is higher incidence in males (11 m./4 f.). Severe clinical picture diverse and undefined clinical course, incidence of jaundice radiological findings and posterior evolution are specially noted. Early diagnosis and effective management lined in base to evolution and prognosis. Hospital stay varied between 2 and 12 weeks. No deaths were registered.

Age Factors↗
PubMedDate not supplied

[Natural history of urinary tract infection in children].

Urinary tract infection was studied in 61 children whose ages ranged between 6 months and 9 years. History, symptoms, urine cultures and renal function are compared between those with normal radiology and those with pyelonephritis and/or reflux and obstructive lesions. Prognosis was analized in these two groups.

Age Factors↗
PubMedDate not supplied

Treatment of rhinocerebral mucormycosis by combination of endoscopic sinus debridement and amphotericin B.

Rhinocerebral mucormycosis (RCM) is an aggressive fungal infection with a high mortality rate. It frequently develops in patients with uncontrolled diabetes mellitus or immunocompromised patients. RCM typically presents in a rapidly fulminant manner with headache, fever, mucosal necrosis, and ophthalmic symptoms. Although the definitive diagnosis is achieved by histopathological examination, computed tomography (CT) scanning and magnetic resonance (MR) are the best imaging procedures in early diagnosis to assess the extent of the disease.

Amphotericin B↗
PubMedDate not supplied

[Secondary amyloidosis (AA) and renal disease].

Amyloidosis is a disease resulting from extracellular deposition of fibrillar protein in various organs. AA amyloidosis may complicate chronic inflammatory diseases, chronic infections and another chronic diseases. We review 31 patients (13 males and 18 females) with biopsy proven renal or rectal AA amyloidosis, referred to out hospital between january 1999 and november 2002. Renal failure was defined as serum creatinine > or = 1.5 mg/dl. Mean age was 58.4 +/- 15.7 years. The causes of AA amyloidosis were an underlying chronic rheumatologic disease (51.6%), chronic infection (41.9%) and a chronic inflammatory intestinal disorder (6.5%). Renal failure (RF) was detected in 20 patients (61.2%) and proteinuria and hematuria were found in 90.3% and 45.5 respectively. Proteinuria at diagnosis was 5.2 +/- 3.9 g/24 h and mean serum creatinine 3.5 +/- 3.7 mg/dl. Survival of patients without dialysis was 66.8 (51.1% RF, 90.9% non-RF) and 53.4% (38.2 RF, 77.9% non-RF) at 12 and 24 months respectively (p = 0.017). End-stage renal disease developed in 13 patients (41.9%). Ten patients were maintained on hemodialysis and 3 on CAD. Survival in dialysis at 6 and 12 months was 68.3% and 42.7% respectively. Fifteen patients died and the main causes of death were: infections (46.6) haemorrhagic complications (33.3%), cardiovascular events (13.3%) and cachexia (6.6%).

Amyloidosis↗
PubMedDate not supplied

[Metabolic consequences of the nonenzymatic glucosylation of apolipoproteins].

The non enzymatic glucosylation (NEG) of proteins is a complex chemical reaction resulting in the formation of a stable bond between a glucose molecule and a protein aminogroup. In diabetics, hyperglycaemia may induce a large increase of NEG. Although the NEG of apolipoproteins remains moderate because of their short half-life, it may alter some of their properties. The NEG of LDL apo B induces a decrease of their catabolism due to a lowering of their binding to the LDL receptor. Glucosylated LDL can accumulate in macrophages, thereby facilitating the development of foam cells. The LDL NEG may also cause other processes including apo B oxidation and production of anti-LDL antibodies. The HDL NEG which essentially corresponds to that of apo A-I, induces a shortening of their half-life. In vitro, the NEG of apo A-I results in a decrease of its interaction with HDL surface. Finally, the binding of glucosylated HDL3 to HDL receptors is decreased in cultured fibroblasts. Since the level of lipoprotein NEG in vivo is moderate, the question as to whether this process may affect quantitatively the metabolic behaviour of lipoproteins and participate to the development of atheroma in diabetic patients, has not been clearly answered.

Apolipoproteins↗
PubMedDate not supplied

Characterization of the non enzymatic glycation of high density lipoprotein in diabetic patients.

In diabetic patients, hyperglycaemia results in the non enzymatic glycation of many proteins. We studied the glycation of HDL of patients with either type 1 or type 2 diabetes compared with that of control subjects. Although a basal glycation was detectable in HDL of normal individuals, this increased by about 400% in HDL of both groups of diabetic patients. The degree of HDL glycation was positively correlated with blood glucose concentration. All the HDL apoproteins were glycated but the glycation of apo A-I represented about 80% of the total HDL. These data were compared to those obtained in vitro after incubation of normal apo A-I either as free molecular species or as phospholipid/apo A-I complex, in the presence of glucose (0 to 80 mmol/l) at 37 degrees C. The resulting apo A-I glycation was dependent upon both time of incubation and glucose concentration and was largely increased in the presence of phospholipids. These data suggest that the in vivo glycation of HDL apoproteins might depend upon glucose concentration but might also be partly influenced by their lipid environment.

Adult↗