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2.
J Endocrinol Invest ; 46(11): 2343-2352, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37037973

ABSTRACT

PURPOSE: To evaluate the prevalence, risk factors and evolution of diabetes mellitus (DM) after targeted treatment in patients with primary aldosteronism (PA). METHODS: A retrospective multicenter study of PA patients in follow-up at 27 Spanish tertiary hospitals (SPAIN-ALDO Register). RESULTS: Overall, 646 patients with PA were included. At diagnosis, 21.2% (n = 137) had DM and 67% of them had HbA1c levels < 7%. In multivariate analysis, family history of DM (OR 4.00 [1.68-9.53]), the coexistence of dyslipidemia (OR 3.57 [1.51-8.43]) and advanced age (OR 1.04 per year of increase [1.00-1.09]) were identified as independent predictive factors of DM. Diabetic patients were on beta blockers (46.7% (n = 64) vs. 27.5% (n = 140), P < 0.001) and diuretics (51.1% (n = 70) vs. 33.2% (n = 169), p < 0.001) more frequently than non-diabetics. After a median follow-up of 22 months [IQR 7.5-63.0], 6.9% of patients developed DM, with no difference between those undergoing adrenalectomy and those treated medically (HR 1.07 [0.49-2.36], p = 0.866). There was also no significant difference in the evolution of glycemic control between DM patients who underwent surgery and those medically treated (p > 0.05). CONCLUSION: DM affects about one quarter of patients with PA and the risk factors for its development are common to those of the general population. Medical and surgical treatment provides similar benefit in glycemic control in patients with PA and DM.


Subject(s)
Diabetes Mellitus , Hyperaldosteronism , Humans , Prevalence , Spain/epidemiology , Diabetes Mellitus/epidemiology , Diabetes Mellitus/etiology , Risk Factors , Hyperaldosteronism/complications , Hyperaldosteronism/epidemiology , Hyperaldosteronism/therapy , Registries
3.
J Endocrinol Invest ; 46(4): 805-814, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36323983

ABSTRACT

PURPOSE: To compare the intraoperative and surgical outcomes of normotensive pheochromocytomas and sympathetic paragangliomas (PPGLs), hypertensive PPGLs and non-PPGL adrenal lesions. METHODS: This a retrospective multicenter cohort study of patients with PPGLs from 18 tertiary hospitals. A control group of histologically confirmed adrenocortical adenomas (non-PPGL group) was selected to compare intraoperative and surgical outcomes with of the normotensive PPGLs. RESULTS: Two hundred and ninety-six surgeries performed in 289 patients with PPGLs were included. Before surgery, 209 patients were classified as hypertensive PPGLs (70.6%) and 87 as normotensive PPGLs. A higher proportion of normotensive PPGLs than hypertensive PPGLs did not receive alpha presurgical blockade (P = 0.009). When we only considered those patients who received presurgical alpha blockers (200 hypertensive PPGLs and 76 normotensive PPGLs), hypertensive PPGLs had a threefold higher risk of intraoperative hypertensive crisis (OR 3.0 [95% 1.3-7.0]) and of hypotensive episodes (OR 2.9 [95% CI 1.2-6.7]) than normotensive PPGLs. When we compared normotensive PPGLs (n = 76) and non-PPGLs (n = 58), normotensive PPGLs had a fivefold higher risk of intraoperative complications (OR 5.3 [95% CI 1.9-14.9]) and a six times higher risk of postoperative complications (OR 6.1 [95% CI 1.7-21.6]) than non-PPGLs. CONCLUSION: Although the risk of intraoperative hypertensive and hypotensive episodes in normotensive PPGLs is significantly lower than in hypertensive PPGLs, normotensive PPGLs have a greater risk of intraoperative and postoperative complications than non-PPGL adrenal lesions. Therefore, it is recommended to follow the standard of care for presurgical and anesthetic management of PPGLs also in normotensive PPGLs.


Subject(s)
Adrenal Gland Neoplasms , Hypertension , Paraganglioma , Pheochromocytoma , Humans , Pheochromocytoma/surgery , Pheochromocytoma/pathology , Cohort Studies , Paraganglioma/surgery , Paraganglioma/pathology , Hypertension/epidemiology , Adrenal Gland Neoplasms/surgery , Adrenal Gland Neoplasms/pathology , Treatment Outcome
5.
Arch Soc Esp Oftalmol (Engl Ed) ; 95(4): 192-195, 2020 Apr.
Article in English, Spanish | MEDLINE | ID: mdl-32147131

ABSTRACT

A 21-year-old woman seen in this clinic with non-reactive mydriasis in the right eye that contracted with 1% pilocarpine. Cranial angio-CT and 1.5 T magnetic resonance imaging (MRI) did not detect any disease. Given a subsequent limitation of adduction, supraduction, and infarction of the right eye, a 3 T MRI was requested. This showed a lesion of the midbrain at the exit of the 3rd cranial nerve. After improvement, no new episodes were observed until 18 months later, when the patient presented with probable optic neuritis and systemic symptoms. At this time the 1.5 T MRI detected infratentorial and supratentorial demyelinating plaques. A subsequent lumbar puncture and clinic outcome confirmed the diagnosis of relapsing-remitting multiple sclerosis.


Subject(s)
Anisocoria/etiology , Magnetic Resonance Imaging/methods , Multiple Sclerosis, Relapsing-Remitting/complications , Multiple Sclerosis, Relapsing-Remitting/diagnostic imaging , Female , Humans , Young Adult
6.
Arch Soc Esp Oftalmol (Engl Ed) ; 95(3): 146-149, 2020 Mar.
Article in English, Spanish | MEDLINE | ID: mdl-31980323

ABSTRACT

The case concerns a 26-year-old patient with bilateral recurrent optic neuritis episodes in the context of suspected neuromyelitis optica. In the first outbreak, she had greatly impaired visual acuity of the left eye, as well as seeing ganglion cell layer damage in both eyes in the optic coherence tomography, with evidence of a possible extensive lesion in the optic chiasma. Likewise, MRI with contrast showed a great involvement of the left optic nerve that compromises the chiasma increasing the suspicion of a neuromyelitis origin. Althogh the anti-myelin oligodendrocyte glycoprotein (MOG) and anti-AQP4 (aquaporin-4) antibodies were negative at first, bilateral involvement of the ganglion cells suggested an extensive lesion that is more characteristic of seropositive anti-MOG neuromyelitis.


Subject(s)
Myelin-Oligodendrocyte Glycoprotein , Neuromyelitis Optica/diagnostic imaging , Retina/diagnostic imaging , Adult , Female , Humans
7.
Todo hosp ; (223): 35-39, ene.-feb. 2006. Tab
Article in Spanish | IBECS | ID: ibc-75653

ABSTRACT

En este trabajo se busca una definición para el término , acudiendo a las referencias existentes en los ámbitos norteamericano y español. Dichas definiciones sirven para incidir en la asistencia urgente hospitalaria y matizar un estado de la cuestión utilizando como ejemplo un hospital en la isla de Mallorca (AU)


This work seeks to provide a definition for the term “Emergency” referring to the existing references in the North American and Spanish sectors. Such definitions help to have an impact on hospital emergency care and to clarify a state of the question using a Hospital on the island of Mallorca as an example (AU)


Subject(s)
Humans , Male , Female , Adult , Patient Satisfaction/statistics & numerical data , Hospital Statistics , Hospitals, University/statistics & numerical data , Health Care Surveys/statistics & numerical data , Quality of Health Care/statistics & numerical data , /statistics & numerical data
9.
Cuad. gest. prof. aten. prim. (Ed. impr.) ; 10(3): 110-114, jul. 2004. tab
Article in Es | IBECS | ID: ibc-35071

ABSTRACT

Objetivo. Establecer un consenso sobre cómo debe ser el maletín para domicilios (MD) del médico de familia y el maletín de urgencias (MU) del centro de salud. Métodos. Revisión bibliográfica y búsqueda de consenso mediante un panel de expertos compuesto por 9 médicos (farmacólogo clínico, anestesista, intensivista, 6 médicos de familia), realizado en atención primaria de Mallorca. A partir de la revisión bibliográfica se elaboró un listado exhaustivo sobre las características y contenidos del MD y del MU, de acuerdo con la medicación, los instrumentos diagnósticos, el material de curas y los impresos. En el panel de expertos se decidió si cada uno de los elementos era imprescindible, opcional o innecesario para el MD y el MU. Resultados. La revisión identificó 191 elementos. Se consideró que 33 eran imprescindibles para el MD y 72 para el MU. De los 94 principios activos identificados, 17 se consideraron imprescindibles para el MD y 26 para el MU. De los 17 instrumentos diagnósticos, 5 se consideraron imprescindibles para el MD y 9 para el MU. De los 67 materiales de curas, 8 se consideraron imprescindibles para el MD y 31 para el MU. Finalmente, de los 13 impresos, 3 se incluyeron como imprescindibles para el MD y 6 para el MU. Conclusiones. Se cuenta con un consenso sobre el contenido para el MD y para el MU (AU)


Subject(s)
Humans , Primary Health Care , Physicians, Family , Emergency Medical Services , Equipment and Supplies/statistics & numerical data , Home Nursing
10.
Rev Argent Microbiol ; 32(3): 116-22, 2000.
Article in Spanish | MEDLINE | ID: mdl-11008702

ABSTRACT

We analyzed the in vitro infection process by P. brasiliensis and the effect of extracellular factor(s) produced on monolayers of mammalian Vero cell lines. The yeast phase of four strains was studied: B339 (avirulent or slightly virulent), U, (intermediate virulence), 93745 and 63265 (both highly virulent). Strains of intermediate and high virulence had higher adherence at first contact (about 16%). Strain B339 had a slower adherence at first contact (8%) than the others during the same period. The production of extracellular proteases, soluble extracellular factor(s) and extracellular antigen gP43 showed no correlation with the in vitro physiopathogenicity of the analyzed strains. We demonstrate that the Vero model presented in this paper is a suitable system to study infection and virulence in vitro. We are currently assessing its usefulness as a tool for the analysis of the interaction between pathogen, host and antifungal agents.


Subject(s)
Antigens, Fungal , Mycology/methods , Paracoccidioides/physiology , Animals , Chlorocebus aethiops , Culture Media , Fungal Proteins/biosynthesis , Glycoproteins/biosynthesis , Oligosaccharides/biosynthesis , Paracoccidioides/classification , Paracoccidioides/growth & development , Paracoccidioides/pathogenicity , Species Specificity , Vero Cells/microbiology , Virulence
11.
Rev. argent. microbiol ; 32(3): 116-122, jul.-sept. 2000.
Article in Spanish | LILACS | ID: lil-332527

ABSTRACT

We analyzed the in vitro infection process by P. brasiliensis and the effect of extracellular factor(s) produced on monolayers of mammalian Vero cell lines. The yeast phase of four strains was studied: B339 (avirulent or slightly virulent), U, (intermediate virulence), 93745 and 63265 (both highly virulent). Strains of intermediate and high virulence had higher adherence at first contact (about 16). Strain B339 had a slower adherence at first contact (8) than the others during the same period. The production of extracellular proteases, soluble extracellular factor(s) and extracellular antigen gP43 showed no correlation with the in vitro physiopathogenicity of the analyzed strains. We demonstrate that the Vero model presented in this paper is a suitable system to study infection and virulence in vitro. We are currently assessing its usefulness as a tool for the analysis of the interaction between pathogen, host and antifungal agents.


Subject(s)
Animals , Mycology , Paracoccidioides , Vero Cells/microbiology , Chlorocebus aethiops , Culture Media , Species Specificity , Glycoproteins/biosynthesis , Oligosaccharides/biosynthesis , Paracoccidioides , Fungal Proteins/biosynthesis , Virulence
12.
Rev. argent. microbiol ; 32(3): 116-122, jul.-sept. 2000.
Article in Spanish | BINACIS | ID: bin-6726

ABSTRACT

We analyzed the in vitro infection process by P. brasiliensis and the effect of extracellular factor(s) produced on monolayers of mammalian Vero cell lines. The yeast phase of four strains was studied: B339 (avirulent or slightly virulent), U, (intermediate virulence), 93745 and 63265 (both highly virulent). Strains of intermediate and high virulence had higher adherence at first contact (about 16). Strain B339 had a slower adherence at first contact (8) than the others during the same period. The production of extracellular proteases, soluble extracellular factor(s) and extracellular antigen gP43 showed no correlation with the in vitro physiopathogenicity of the analyzed strains. We demonstrate that the Vero model presented in this paper is a suitable system to study infection and virulence in vitro. We are currently assessing its usefulness as a tool for the analysis of the interaction between pathogen, host and antifungal agents.(AU)


Subject(s)
Comparative Study , Animals , Mycology/methods , Paracoccidioides/physiology , Chlorocebus aethiops , Culture Media , Fungal Proteins/biosynthesis , Glycoproteins/biosynthesis , Oligosaccharides/biosynthesis , Paracoccidioides/classification , Paracoccidioides/growth & development , Paracoccidioides/pathogenicity , Species Specificity , Vero Cells/microbiology , Virulence
13.
Medicina (B Aires) ; 60(2): 249-52, 2000.
Article in English | MEDLINE | ID: mdl-10962819

ABSTRACT

We report a case of a nine-year old boy with vomiting, abdominal pain and fever, who underwent surgery with a diagnosis of appendicitis in Mendoza and from whom a Shiga toxin-producing Escherichia coli (STEC) O127:H21 strain was recovered. Forty-eight hours after surgery he presented bilious vomiting and two episodes of intestinal bleeding. Laboratory findings included: hematocrit, 35%; blood urea nitrogen, 0.22 g/L. The urinary output was normal. The following day physical examination showed an alert mildly hydrated child, without fever but with distended and painful abdomen. The patient was again submitted to surgery with a diagnosis of intestinal occlusion. Bleeding and multiple adhesions in jejunum and ileum were found. The patient still had tense and painful abdomen and presented two bowel movements with blood; hematocrit fell to 29% and blood urea nitrogen rose to 0.32 g/L. STEC O127:H21 eae(-)/Stx2/Stx2vh-b(+)/E-Hly(+) was isolated from a stool sample. He was discharged after 10 days of hospitalization and no long-term complications such as HUS or TTP were observed. This is the first report, to our knowledge, on the isolation of E. coli O127:H21, carrying the virulence factors that characterize STEC strains, associated to an enterohemorrhagic colitis case. This serotype was previously characterized as a non-classic enteropathogenic E. coli (EPEC). STEC infections can mimic infectious or noninfectious pathologies. Therefore an important aspect of clinical management is making the diagnosis using different criteria thereby avoiding misdiagnoses which have occasionally led to invasive diagnostic and therapeutic procedures or the inappropriate use of antibiotics.


Subject(s)
Bacterial Toxins/biosynthesis , Escherichia coli Infections/complications , Escherichia coli , Gastrointestinal Hemorrhage/microbiology , Intestinal Obstruction/microbiology , Abdomen/microbiology , Child , Enterocolitis/microbiology , Escherichia coli/isolation & purification , Escherichia coli/pathogenicity , Escherichia coli Infections/diagnosis , Humans , Male , Shiga Toxins
14.
Plant Physiol ; 123(3): 979-86, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10889246

ABSTRACT

1-Aminocyclopropane-1-carboxylic acid synthase (ACS) is one of the key regulatory enzymes involved in the synthesis of the hormone ethylene and is encoded by a multigene family containing at least eight members in tomato (Lycopersicon esculentum). Increased ethylene production accompanies ripening in tomato, and this coincides with a change in the regulation of ethylene synthesis from auto-inhibitory to autostimulatory. The signaling pathways that operate to bring about this transition from so-called system-1 to system-2 ethylene production are unknown, and we have begun to address these by investigating the regulation of ACS expression during ripening. Transcripts corresponding to four ACS genes, LEACS1A, LEACS2, LEACS4, and LEACS6, were detected in tomato fruit, and expression analysis using the ripening inhibitor (rin) mutant in combination with ethylene treatments and the Never-ripe (Nr) mutant has demonstrated that each is regulated in a unique way. A proposed model suggests that system-1 ethylene is regulated by the expression of LEACS1A and LEACS6. In fruit a transition period occurs in which the RIN gene plays a pivotal role leading to increased expression of LEACS1A and induction of LEACS4. System-2 ethylene synthesis is subsequently initiated and maintained by ethylene-dependent induction of LEACS2.


Subject(s)
Amino Acids, Cyclic , Ethylenes/biosynthesis , Gene Expression Regulation, Plant , Lyases/genetics , Plant Growth Regulators/biosynthesis , Solanum lycopersicum/genetics , Amino Acids/metabolism , Blotting, Northern , Chromatography, Gas , Ethylenes/metabolism , Ethylenes/pharmacology , Fruit/genetics , Fruit/metabolism , Fruit/physiology , Lyases/metabolism , Solanum lycopersicum/metabolism , Solanum lycopersicum/physiology , Models, Biological , Plant Growth Regulators/metabolism , RNA, Messenger/analysis
15.
Medicina [B Aires] ; 60(2): 249-52, 2000.
Article in English | BINACIS | ID: bin-39827

ABSTRACT

We report a case of a nine-year old boy with vomiting, abdominal pain and fever, who underwent surgery with a diagnosis of appendicitis in Mendoza and from whom a Shiga toxin-producing Escherichia coli (STEC) O127:H21 strain was recovered. Forty-eight hours after surgery he presented bilious vomiting and two episodes of intestinal bleeding. Laboratory findings included: hematocrit, 35


; blood urea nitrogen, 0.22 g/L. The urinary output was normal. The following day physical examination showed an alert mildly hydrated child, without fever but with distended and painful abdomen. The patient was again submitted to surgery with a diagnosis of intestinal occlusion. Bleeding and multiple adhesions in jejunum and ileum were found. The patient still had tense and painful abdomen and presented two bowel movements with blood; hematocrit fell to 29


and blood urea nitrogen rose to 0.32 g/L. STEC O127:H21 eae(-)/Stx2/Stx2vh-b(+)/E-Hly(+) was isolated from a stool sample. He was discharged after 10 days of hospitalization and no long-term complications such as HUS or TTP were observed. This is the first report, to our knowledge, on the isolation of E. coli O127:H21, carrying the virulence factors that characterize STEC strains, associated to an enterohemorrhagic colitis case. This serotype was previously characterized as a non-classic enteropathogenic E. coli (EPEC). STEC infections can mimic infectious or noninfectious pathologies. Therefore an important aspect of clinical management is making the diagnosis using different criteria thereby avoiding misdiagnoses which have occasionally led to invasive diagnostic and therapeutic procedures or the inappropriate use of antibiotics.

16.
Rev. argent. microbiol ; 32(3): 116-22, 2000 Jul-Sep.
Article in Spanish | BINACIS | ID: bin-39795

ABSTRACT

We analyzed the in vitro infection process by P. brasiliensis and the effect of extracellular factor(s) produced on monolayers of mammalian Vero cell lines. The yeast phase of four strains was studied: B339 (avirulent or slightly virulent), U, (intermediate virulence), 93745 and 63265 (both highly virulent). Strains of intermediate and high virulence had higher adherence at first contact (about 16


). Strain B339 had a slower adherence at first contact (8


) than the others during the same period. The production of extracellular proteases, soluble extracellular factor(s) and extracellular antigen gP43 showed no correlation with the in vitro physiopathogenicity of the analyzed strains. We demonstrate that the Vero model presented in this paper is a suitable system to study infection and virulence in vitro. We are currently assessing its usefulness as a tool for the analysis of the interaction between pathogen, host and antifungal agents.

17.
Medicina (B Aires) ; 58(1): 1-7, 1998.
Article in Spanish | MEDLINE | ID: mdl-9674201

ABSTRACT

Shiga toxin-producing Escherichia coli (STEC) has been associated with pathogenesis of hemolytic uremic syndrome (HUS) worldwide. The aim of the present study was to characterize the HUS cases reported in Mendoza and to determine their association with STEC infection. From July 1994 through June 1996 thirty-six patients with HUS were admitted to Hospital Pediátrico "Dr. HJ Notti" (Mean age 22.8 +/- 14.9 months, 44% females). The children developed HUS following an acute diarrheal illness in 94.4% of the cases. Bloody diarrhea was observed in 83.3% of them. Antimicrobial therapy had been administered to 69.4% of the patients. Most of the patients were well-nourished (88.9%), belong to middle-low socioeconomical condition (91.7%), from urban areas (72.2%) and they were mostly assisted during summer and the beginning of autumn. The acute stage of the disease occurred with presentation of pallor (100%), edema (25%), anuria (38.9%), oliguria (41.7%), hemolytic anemia (97.2%), thrombocytopenia (86.1%) and neurological involvement (41.7%). Twenty-five of them presented the full clinical syndrome. Peritoneal dialysis were performed in 50% and packed blood cell transfusion in 88.9%. The mean days of hospitalization was 15.1 +/- 9.2 [range 1-32]. A 91.7% of the patients recovered renal function, two developed chronic renal failure and one died. Cumulative evidence of STEC infection was found in 19 (86.4%) of 22 HUS patients. STEC O157:H7, biotype C was found in 8 (36.4%). The prevalent Stx type was Stx2 in STEC, free fecal Stx (STMF) and Stx-neutralizing antibodies (a-Stx). In Mendoza, as in the rest of Argentina E. coli O157:H7, biotype C, Stx2 producer is the most frequently detected pathogen in HUS cases.


Subject(s)
Bacterial Toxins , Escherichia coli Infections/complications , Escherichia coli , Hemolytic-Uremic Syndrome/microbiology , Argentina , Child , Child, Preschool , Female , Hemolytic-Uremic Syndrome/drug therapy , Hemolytic-Uremic Syndrome/epidemiology , Humans , Infant , Male , Nutritional Status , Socioeconomic Factors
18.
Rev. argent. microbiol ; 29(4): 167-75, oct.-dic. 1997. tab, graf
Article in English | LILACS | ID: lil-223411

ABSTRACT

El objetivo de este trabajo fue estudiar la cinetica de produccion de los distintos tipos de toxinas Shiga (Stx1; Stx2c) asociadas a Escherichia coli, en cepas de referencia y aisladas de pacientes con Sindrome Uremico Hemolitico (SUH). Las cepas fueron cultivadas en caldo Penassay e incubadas a 37§ con agitacion (200 rpm), tomandose muestras a distintos tiempos (1,5; 3; 9 y 24 horas) para determinar el crecimiento bacteriano y la citotoxicidad libre y asociada a celulas. Para Stx1, a las 3 horas de incubacion, la relacion entre la concentracion intracelular y la extracelular (ic/ec), estuvo comprendida entre 32 y 200 veces. A las 24 horas, ambas concentraciones se igualaron o (ec) resulto 2 veces mayor, dependiendo de la cepa estudiada. Sin embargo, tanto la actividad citotoxica libre como la asociada a celulas presentaron titulos muy bajos. Esto indico una perdida de actividad durante la fase estacionaria que podria deberse al cese de la sintesis de Stx1 o la accion de enzimas proteoliticas. Para Stx2, a las 3 horas (ic) fue igual o 2 veces superior a (ec), a las 34 horas (ec) fue 16 a 32 veces superior a (ic). Para Stx2c, (ec) aumento logaritmicamente con un rendimiento maximo a las 5 horas, permaneciendo luego constante hasta las 24 horas. En ese tiempo (ic) fue dos veces superior a (ec). El estudio de la cinetica de produccion de Stx por cepas de E. coli aisladas de pacientes con SUH demostro que correspondian al tipo Stx2. Estos resultados fueron confirmados por ensayos de citotoxicidad especifica en celulas Vero y por hibridacion con sondas geneticas. El tipo de Stx es considerado uno de los mayores factores de riesgo en la evolucion a SUH en pacientes infectados con E. coli enterohemorragicos. Por lo tanto, la disminucion de la citotoxicidad de Stx1, durante la fase estacionaria de crecimiento, podria explicar la mayor frecuencia de accion entre SUH y cepas de E. coli productoras de Stx2 en distintos paises, incluyendo Argentina


Subject(s)
Cytotoxicity, Immunologic , Cytotoxins/biosynthesis , Enterotoxins/biosynthesis , Escherichia coli , Kinetics , Hemolytic-Uremic Syndrome/immunology
19.
Rev. argent. microbiol ; 29(4): 167-75, oct.-dic. 1997. tab, graf
Article in English | BINACIS | ID: bin-17457

ABSTRACT

El objetivo de este trabajo fue estudiar la cinetica de produccion de los distintos tipos de toxinas Shiga (Stx1; Stx2c) asociadas a Escherichia coli, en cepas de referencia y aisladas de pacientes con Sindrome Uremico Hemolitico (SUH). Las cepas fueron cultivadas en caldo Penassay e incubadas a 37º con agitacion (200 rpm), tomandose muestras a distintos tiempos (1,5; 3; 9 y 24 horas) para determinar el crecimiento bacteriano y la citotoxicidad libre y asociada a celulas. Para Stx1, a las 3 horas de incubacion, la relacion entre la concentracion int


Subject(s)
Cytotoxins/biosynthesis , Escherichia coli , Kinetics , Hemolytic-Uremic Syndrome/immunology , Enterotoxins/biosynthesis , Cytotoxicity, Immunologic
20.
Rev Argent Microbiol ; 29(4): 167-75, 1997.
Article in English | MEDLINE | ID: mdl-9472138

ABSTRACT

We studied the differential kinetic patterns for Shiga toxin (Stx) production (i.e. Stx1, Stx2 and Stx2c) in different reference Escherichia coli strains and in those isolated from hemolytic uremic syndrome (HUS) patients. These results were correlated with those obtained by specific cytotoxic activity assays on Vero cells and hybridization tests with DNA probes for Stx1 and Stx2. Strains cultured in Penassay broth were sampled at 1.5; 3; 5; 9 and 24 hours to determine bacterial growth and its association with cell-bound and free cytotoxicity. Stx1 showed an intracellular/extracellular concentration ratio (ic/ec) between 32 and 200 times after 3 h-growth. At 24 h both Stx1 concentrations were equal or, in some strains, the ec resulted 2-fold higher that the ic. The ic-Stx1 was equal or just 2-fold higher that ec after 3 h-growth. However, at 24 h the released toxin level was 16 to 32 times higher that cell-bound toxin. The ec-Stx2c increased logarithmically, with maximal yields at 5 h, remaining constant up to 24 h. At that time ic-toxin was 2-fold higher than the released one. When the same experiments were performed on strains isolated from HUS patients they showed that the kinetic patterns obtained corresponded to Stx2. These results were confirmed by hybridization assays. In this study we have shown that Stx1 production decreases dramatically during stationary phase while Stx2 is detected at high level at that time. This could explain the higher frequency of association of Stx2-producing E. coli strains and HUS in some countries, including Argentina.


Subject(s)
Bacterial Toxins/biosynthesis , Escherichia coli/metabolism , Animals , Biomarkers , Chlorocebus aethiops , Diarrhea, Infantile/microbiology , Escherichia coli/isolation & purification , Escherichia coli Infections/microbiology , Hemolytic-Uremic Syndrome/microbiology , Humans , Infant , Kinetics , Shiga Toxins , Species Specificity , Vero Cells
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