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1.
Ann Ig ; 35(5): 560-571, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37057652

RESUMEN

Background: Increasing adherence to influenza vaccination among healthcare workers is a public health priority, stated that actually remains far below than international recommendations. During the 2020/2021 pandemic season, COVID-19 vaccines were not yet available until the end of December 2020, and influenza vaccines were the only one available to protect against seasonal respiratory diseases. The main objective of the present study was to assess knowledge, attitudes and adherence to influenza and other vaccinations recommended by the National Immunization Plan 2017-2021 for healthcare workers. Methods: Enrollment lasted from October and December 2020 at the vaccination unit of the University Hospital of Palermo. Data were collected through an anonymous and self-administered questionnaire, divided into 5 sections and 31 items. Results: Among 734 healthcare professionals that completed the survey, a significantly higher adherence to influenza vaccination was observed among healthcare workers that were more prone to receive COVID-19 vaccination (OR=4.02; 95% CI: 1.63-9.91). Moreover, higher influenza vaccination rates were observed among healthcare professionals that received influenza vaccination during previous 2019/2020 season (OR=15.3; 95% CI: 5.17-45.1) and that were favorable to the possible impact on increasing adherence of influenza mandatory vaccination (OR=4.88; 95% CI: 2.43-9.80). Conclusions: Propensity of healthcare workers to undergo vaccinations recommended in the National Immunization Plan increased during the first pandemic season. At the end of the vaccination season, flu vaccination coverage reached highest rates ever at the University Hospital of Palermo (around 60%), remaining anyway below the recommended minimum value of 75%. During next seasonal flu vaccination campaigns, it becomes essential to promote communication and information strategies to increase flu vaccination among healthcare workers, also focusing on co-administration with the anti-COVID-19 booster/seasonal doses.


Asunto(s)
COVID-19 , Vacunas contra la Influenza , Gripe Humana , Humanos , Gripe Humana/epidemiología , Gripe Humana/prevención & control , Estaciones del Año , Vacunas contra la COVID-19 , Pandemias/prevención & control , Conocimientos, Actitudes y Práctica en Salud , COVID-19/prevención & control , Vacunación , Italia/epidemiología , Hospitales Universitarios , Actitud del Personal de Salud , Personal de Salud
2.
Tech Coloproctol ; 26(12): 963-971, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36104607

RESUMEN

BACKGROUND: Surgical management of obstructed defecation syndrome (ODS) is challenging, with several surgical options showing inconsistent functional results over time. The aim of this study was to evaluate the trend in surgical management of ODS in a 10-year timeframe across Italian referral centers. METHODS: Surgeons from referral centers for the management of pelvic floor disorders and affiliated to the Italian Society of Colorectal Surgery provided data on the yearly volume of procedures for ODS from 2010 to 2019. Six common clinical scenarios of ODS were captured, including details on patient's anal sphincter function and presence of rectocele and/or rectal intussusception. Perineal repair, ventral rectopexy (VRP), transanal repair (internal Delorme), stapled transanal rectal resection (STARR), Contour Transtar, and transvaginal repair were considered in each clinical scenario. RESULTS: Twenty-five centers were included providing data on 2943 surgical patients. Procedure volumes ranged from 10-20 (54%) to 21-50 (46%) per year across centers. The most performed techniques in patients with good sphincter function were transanal repair for isolated rectocele (243/716 [34%]), transanal repair for isolated rectal intussusception (287/677 [42%]) and VRP for combined abnormalities (464/976 [48%]). When considering poor sphincter function, these were perineal repair (112/194 [57.8%]) for isolated rectocele, and VRP for the other two scenarios (60/120 [50%] and 97/260 [37%], respectively). The use of STARR and Contour Transtar decreased over time in patients with impaired sphincter function. CONCLUSIONS: The complexity of ODS treatment is confirmed by the variety of clinical scenarios that can occur and by the changing trend of surgical management over the last 10 years.


Asunto(s)
Cirugía Colorrectal , Intususcepción , Femenino , Humanos , Rectocele/complicaciones , Rectocele/cirugía , Defecación , Intususcepción/complicaciones , Intususcepción/cirugía , Estreñimiento/etiología , Estreñimiento/cirugía , Grapado Quirúrgico/métodos , Resultado del Tratamiento , Síndrome , Recto/cirugía
3.
Infection ; 42(3): 535-8, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24448875

RESUMEN

A survey was performed in May 2013 to assess methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization in healthy children attending 26 municipal daycare centres in Palermo, Italy. Of the 500 children, ten (2 %) tested positive. Eight MRSA isolates were tst1-positive ST22-MRSA-IVa, spa t223; the other two isolates were identified as ST1-IVa and ST398-V, respectively. tst1-positive ST22-MRSA, spa t223 has been previously identified only in the Middle Eastern area.


Asunto(s)
Portador Sano/epidemiología , Portador Sano/microbiología , Staphylococcus aureus Resistente a Meticilina/clasificación , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Tipificación Molecular , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/microbiología , Preescolar , Recolección de Datos , Femenino , Genotipo , Humanos , Masculino , Staphylococcus aureus Resistente a Meticilina/genética , Epidemiología Molecular , Sicilia/epidemiología
4.
Rev Esp Anestesiol Reanim (Engl Ed) ; 70(9): 501-508, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37678449

RESUMEN

INTRODUCTION AND OBJECTIVES: Data on the efficacy of PENG (Pericapsular Nerve Group) block in hip trauma pain are scarce. We hypothesized that PENG block was more effective than infra-inguinal ultrasound-guided FIB (Fascia Iliaca block) for pain control in patients aged 65 years or older presenting in the emergency room (ER) with traumatic proximal femoral fracture. MATERIALS AND METHODS: We conducted an exploratory, double-blind, randomized controlled trial. One anaesthesiologist performed the block and another assessed outcomes. Patients were randomly allocated to the PENG group (20 ml ropivacaine 0.375%) or the infrainguinal FIB group (40 ml ropivacaine 0.2%). Standard hypothesis tests (t test or χ2 test) were performed to analyse baseline characteristics and outcome parameters. The primary end-point of the study was analgesic success, defined as "NRS pain score ≤ 4" 30 min after blockade, with PENG vs to FIB. Secondary outcomes were pain at rest ("pain at rest NRS score ≤ 4" 30 min after blockade), duration of analgesia (time to first request for analgesia), need for rescue medication in case of block failure, and complications during blockade. RESULTS: After obtaining ethical committee approval and written informed consent, 60 patients were included. The primary endpoint was achieved in 16 out of 30 patients (53.3%) in the PENG group and in 15 out of 28 patients (53.6%) in the FIB group. Comparison between groups did not show superiority of the PENG vs FIB (P-value .98). CONCLUSIONS: PENG block does not provide better pain than FIB in proximal femoral fracture in elderly patients treated in the ER.


Asunto(s)
Nervio Femoral , Fracturas Óseas , Anciano , Humanos , Ropivacaína , Analgésicos/uso terapéutico , Dolor , Fémur/diagnóstico por imagen , Fascia , Servicio de Urgencia en Hospital
5.
Nutr Metab Cardiovasc Dis ; 22(7): 605-12, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21333508

RESUMEN

BACKGROUND AND AIMS: To estimate the impact of diabetes and its complications, overall and in different age classes, on the likelihood of hospital admission for specific causes. METHODS AND RESULTS: We carried out a record-linkage analysis of administrative registers including data on 8,940,420 citizens in 21 Local Health Authorities in Italy. Individuals with pharmacologically treated diabetes (≥2 prescriptions of antidiabetic agents during the year 2008) were paired in a 1:1 proportion with those who did not receive such drugs (controls) based on propensity-score matching. Odds Ratios (ORs) of hospitalization for macro and microvascular conditions in individuals with diabetes as compared to controls were estimated. The system identified 498,825 individuals with diabetes pharmacologically treated (prevalence of 5.6%). Prevalence of diabetes in people aged <14 years, 14-39 years, 40-65 years, and ≥65 years was 0.1%, 0.6%, 6.4%, and 18.2%, respectively. Overall, 23.9% of subjects with diabetes and 11.5% of controls had had at least a hospital admission during 12 months for the causes considered. Diabetes increased the likelihood of hospitalization by two to six times for the different causes examined. In absolute terms, diabetes was responsible for an excess of over 12,000 hospital admissions per 100,000 individuals/year. CONCLUSION: Despite the availability of effective treatments to prevent or delay major complications, diabetes still places an enormous burden on both patients and the health care system. Given the continuous rise in diabetes prevalence both in middle-aged and elderly individuals, we can expect an additional, hardly sustainable increase in the demand for health care in the near future.


Asunto(s)
Costo de Enfermedad , Diabetes Mellitus/tratamiento farmacológico , Diabetes Mellitus/epidemiología , Adolescente , Adulto , Anciano , Benzamidas/uso terapéutico , Femenino , Hospitalización , Humanos , Hipoglucemiantes/uso terapéutico , Insulina/uso terapéutico , Italia/epidemiología , Masculino , Metformina/uso terapéutico , Persona de Mediana Edad , Oportunidad Relativa , Prevalencia , Tiazolidinedionas/uso terapéutico , Resultado del Tratamiento , Adulto Joven
6.
Biochim Biophys Acta ; 1802(6): 572-81, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20123124

RESUMEN

We report a novel PPARG germline mutation in a patient affected by colorectal cancer that replaces serine 289 with cysteine in the mature protein (S289C). The mutant has impaired transactivation potential and acts as dominant negative to the wild type receptor. In addition, it no longer restrains cell proliferation both in vitro and in vivo. Interestingly, the S289C mutant poorly activates target genes and interferes with the inflammatory pathway in tumor tissues and proximal normal mucosa. Consistently, only mutation carriers exhibit colonic lesions that can evolve to dysplastic polyps. The proband presented also dyslipidemia, hypertension and overweight, not associated to type 2 diabetes; of note, family members tested positive for the mutation and display only a dyslipidemic profile at variable penetrance with other biochemical parameters in the normal range. Finally, superimposing the mutation to the crystal structure of the ligand binding domain, the new Cys289 becomes so closely positioned to Cys285 to form an S-S bridge. This would reduce the depth of the ligand binding pocket and impede agonist positioning, explaining the biological effects and subcellular distribution of the mutant protein. This is the first PPARG germline mutation associated with dyslipidemia and colonic polyp formation that can progress to full-blown adenocarcinoma.


Asunto(s)
Dislipidemias/genética , Mutación de Línea Germinal , Pólipos Intestinales/genética , PPAR gamma/genética , Adenocarcinoma/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Sustitución de Aminoácidos , Animales , Secuencia de Bases , Sitios de Unión/genética , Células COS , Chlorocebus aethiops , Neoplasias del Colon/genética , Cartilla de ADN/genética , Dislipidemias/metabolismo , Femenino , Humanos , Técnicas In Vitro , Pólipos Intestinales/metabolismo , Pérdida de Heterocigocidad , Masculino , Ratones , Persona de Mediana Edad , Modelos Moleculares , Células 3T3 NIH , PPAR gamma/química , PPAR gamma/metabolismo , Linaje , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transfección , Adulto Joven
7.
Radiol Med ; 116(7): 1124-33, 2011 Oct.
Artículo en Inglés, Italiano | MEDLINE | ID: mdl-21509546

RESUMEN

PURPOSE: This study aimed to evaluate correlations between the position of the tibial tunnel, its alignment with the ligament-screw system, presence of intratunnel fluid, position of the tibial tunnel with respect to the Blumensaat line and clinical knee stability in patients who underwent arthroscopic reconstruction of the anterior cruciate ligament (ACL), by using magnetic resonance (MR) imaging. MATERIALS AND METHODS: Forty-eight patients (40 men, eight women; mean age, 31 years) underwent arthroscopic reconstruction of the ACL using double-strand semitendinosus and gracilis tendons. The new ACL was fixed to the tibial tunnel using Bio-Intrafix (Mitek). All patients underwent MR imaging 12 months after surgery and clinical evaluation at 6 and 12 months using the International Knee Documentation Committee (IKDC) scoring system. MR imaging and clinical features were correlated using the Mann-Whitney U test for continuous variables and Fisher's exact test for categorical variables. RESULTS: Forty-one patients were clinically stable (groups A and B according to the IKDC test) and seven were unstable (group C). Mean values of tibial tunnel position in clinically unstable vs stable patients were, respectively, -3.6 ±3.8 mm vs. -2.8±3.8 mm in relation to the Blumensaat line (p=0.5712) and 77.3°±11.3 vs. 72.5°±5.5 as concerned the angle measured on the coronal view of the new ACL (p=0.3248); fluid was present in the tibial tunnel in 42.9% and 9.8% of cases, respectively (p=0.2104). MR imaging showed misalignment of ligament screw and tibial tunnel in 57.1% of patients in group C and in 12.2% in groups A and B (p=0.017). CONCLUSIONS: Misalignment of the ligament-screw system and the tibial tunnel and the presence of fluid in the tibial tunnel appear to be directly correlated with clinical instability.


Asunto(s)
Reconstrucción del Ligamento Cruzado Anterior , Artroscopía , Traumatismos de la Rodilla/cirugía , Imagen por Resonancia Magnética , Tendones/trasplante , Tibia/cirugía , Adulto , Algoritmos , Ligamento Cruzado Anterior/cirugía , Reconstrucción del Ligamento Cruzado Anterior/métodos , Femenino , Estudios de Seguimiento , Humanos , Articulación de la Rodilla/cirugía , Masculino , Procedimientos de Cirugía Plástica , Estadísticas no Paramétricas , Transferencia Tendinosa , Trasplante Autólogo , Resultado del Tratamiento
8.
Protein Sci ; 6(8): 1682-93, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9260280

RESUMEN

Selective deamidation of proteins and peptides is a reaction of great interest, both because it has a physiological role and because it can cause alteration in the biological activity, local folding, and overall stability of the protein. In order to evaluate the thermodynamic effects of this reaction in proteins, we investigated the temperature-induced denaturation of ribonuclease A derivatives in which asparagine 67 was selectively replaced by an aspartyl residue or an isoaspartyl residue, as a consequence of an in vitro deamidation reaction. Differential scanning calorimetry measurements were performed in the pH range 3.0-6.0, where the unfolding process is reversible, according to the reheating criterion used. It resulted that the monodeamidated forms have a different thermal stability with respect to the parent enzyme. In particular, the replacement of asparagine 67 with an isoaspartyl residue leads to a decrease of 6.3 degrees C of denaturation temperature and 65 kJ mol-1 of denaturation enthalpy at pH 5.0. These results are discussed and correlated to the X-ray three-dimensional structure of this derivative. The analysis leads to the conclusion that the difference in thermal stability between RNase A and (N67isoD)RNase A is due to enthalpic effects arising from the loss of two important hydrogen bonds in the loop containing residue 67, partially counterbalanced by entropic effects. Finally, the influence of cytidine-2'-monophosphate on the stability of the three ribonucleases at pH 5.0 is studied and explained in terms of its binding on the active site of ribonucleases. The analysis makes it possible to estimate the apparent binding constant and binding enthalpy for the three proteins.


Asunto(s)
Amidas/química , Asparagina/química , Ribonucleasa Pancreática/química , Termodinámica , Sitios de Unión , Rastreo Diferencial de Calorimetría , Dicroismo Circular , Citidina Monofosfato/metabolismo , Concentración de Iones de Hidrógeno , Desnaturalización Proteica , Ribonucleasa Pancreática/metabolismo
9.
Am J Cardiol ; 64(16): 991-5, 1989 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-2510489

RESUMEN

Endomyocardial biopsies from 174 patients with dilated cardiomyopathy (DC) were examined. Eight patients with histologically proven myocarditis were excluded from the study. A peculiar pattern of oversized and bizarre nuclei was observed in only some of the remaining patients. Two groups were identified: those with and without this feature (groups A and B, respectively). Myocyte width, nuclear diameter and nuclear/sarcoplasmic ratio were significantly higher in group A. The mean respective values were 36 +/- 5 mu, 14 +/- 3 mu and 0.41 +/- 0.08 for group A versus 20 +/- 8 mu, 7 +/- 2 mu and 0.37 +/- 0.08 for group B. Interstitial fibrosis was similarly present in groups A and B. Endocardial thickness was significantly increased in all patients, with group A showing the highest mean value. The morphologic features showed no correlation with the clinical condition of the patients at time of presentation. HLA typing was performed in 50 consecutive patients, 38 from group A and 12 from group B. DR4 and DR5 antigens were significantly more frequent in DC patients than in a normal population control (400 blood donors), while DR3 was less frequent. Group A was more strongly associated with the DR5 antigen than group B (55.3 vs 25.0%, respectively). It was less strongly associated with the DR4 antigen compared with group B (21.5 vs 41.7%, respectively). No difference was observed between the 2 groups concerning negative association with the DR3 antigen. Endomyocardial biopsies from DC patients reveal marked morphologic changes from patient to patient.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Cardiomiopatía Dilatada/patología , Genes MHC Clase II , Antígenos HLA/análisis , Adolescente , Adulto , Cardiomiopatía Dilatada/genética , Cardiomiopatía Dilatada/inmunología , Endocardio/inmunología , Endocardio/ultraestructura , Femenino , Antígenos HLA-DR/análisis , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo Genético
10.
Am J Cardiol ; 66(12): 973-80, 1990 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-2145740

RESUMEN

Atrial natriuretic peptide (ANP) was immunohistochemically investigated in (1) right ventricular endomyocardial biopsy specimens from 87 apparently healthy donor hearts taken from victims of cerebral accidents; (2) 1 normal heart not suitable for transplantation (HBsAg carrier); (3) right ventricular endomyocardial biopsy specimens from 151 patients with dilated cardiomyopathy (DC); and (4) 57 explanted hearts, 26 with DC and 31 with ischemic heart disease. No ANP immunoreactivity was found in normal ventricles. Failing hearts showed ventricular positivity in 31% of the DC biopsy series, in 61% of the left ventricles, and in 30% of the right ventricles of the explanted heart series. An endoepicardial gradient was observed, because ANP positivity was greater and more extensive in the subendocardial layers. Ultrastructural studies were performed on biopsy specimens from 10 normal hearts and 132 DC biopsy samples. No ANP-storing granules were found in biopsy samples of normal ventricles, whereas ANP granules were seen in 15 of 132 (11.4%) DC cases. In parallel immunoblotting, investigation showed the same 13 kDa band protein in 1 normal atrium as well as in 8 failing atria and ventricles. ANP immunoreactivity was positively correlated with higher New York Heart Association functional classes as well as with higher left ventricular end-diastolic pressure (p less than 0.005), end-diastolic volume (p less than 0.005) and end-diastolic volume index (p less than 0.005). In conclusion, apparently healthy ventricles do not show ANP immunoreactivity, whereas failing ventricles do. ANP expression seems to be independent of the underlying disease, but positively related to the clinical status and the degree of left ventricular impairment and dilatation.


Asunto(s)
Factor Natriurético Atrial/biosíntesis , Cardiomiopatía Dilatada/fisiopatología , Insuficiencia Cardíaca/fisiopatología , Hemodinámica/fisiología , Miocardio/metabolismo , Adulto , Cardiomiopatía Dilatada/metabolismo , Cardiomiopatía Dilatada/patología , Femenino , Insuficiencia Cardíaca/metabolismo , Insuficiencia Cardíaca/patología , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Valores de Referencia
11.
Hum Immunol ; 35(3): 193-9, 1992 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1293083

RESUMEN

Dilated cardiomyopathy (DCM) is an idiopathic heart muscle disorder. The presence of circulating cardiac antibodies and the association with HLA-DR4 are consistent with autoimmune pathogenesis in a subset of patients. Sixty-eight DCM patients and 277 controls were typed for IgG heavy-chain constant region (Gm) and kappa light-chain (Km) allotypes. All patients and 210 of the 277 controls were HLA-DR typed. The Gm (1, 3, 17; 23; 5*, 21, 28) phenotype was overrepresented in DCM compared with controls (25% vs 13%, p = 0.0139, pc = NS, RR = 2.23). The frequency of this phenotype was higher in patients with younger age at onset, shorter symptom duration, and among those who were positive for cardiac as well as for non-organ-specific autoantibodies than in controls. A higher frequency of the Gm (1, +/- 2, 3, 17; +/- 23; 5*, 21, 28) heterozygous phenotypes was also found in DCM compared to controls (40.91% vs 26.89%; p = 0.02, pc = 0.04, RR = 1.88). The finding of Gm heterozygosity in DCM was associated with serum positivity for cardiac antibodies. A higher proportion of DCM patients were positive for both the Gm (1, 3, 17; 23; 5*, 21, 28) phenotype and HLA-DR4 compared to normals (3/68 vs 0/210; p = 0.04, RR = 22.50).(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Cardiomiopatía Dilatada/inmunología , Antígenos HLA/genética , Inmunoglobulinas/genética , Polimorfismo Genético , Adulto , Autoanticuerpos/análisis , Susceptibilidad a Enfermedades , Femenino , Frecuencia de los Genes , Marcadores Genéticos , Humanos , Inmunoglobulina G/genética , Cadenas kappa de Inmunoglobulina/genética , Inmunofenotipificación , Masculino , Persona de Mediana Edad
12.
J Biochem ; 121(3): 568-77, 1997 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9133627

RESUMEN

DSC measurements have been performed on the monomeric form of yeast hexokinase B in the absence and presence of increasing concentrations of D-glucose. The hexokinase, in the absence of D-glucose, at both pH 8.0 and 8.5, shows reproducible calorimetric profiles characterized by the presence of two partially overlapped peaks. These can be ascribed to the presence of two structural domains in the native conformation of the enzyme, that possess different thermal stabilities and are denatured more or less independently. In the presence of saturating and increasing concentrations of D-glucose, the shape of the DSC profiles dramatically changes, since a single well-shaped peak is present. The binding of D-glucose enhances the interaction between the two lobes, as evidenced by the shrinking of the protein in overall dimensions, and gives rise to DSC profiles resembling those of a single domain protein. To deconvolve the DSC curves we considered a denaturation model consisting of two sequential steps with three macroscopic states of the protein and the binding of D-glucose only to the native state. We carried out two-dimensional nonlinear regression of the excess heat capacity surface constructed with the experimental DSC curves. This approach allows the calculation of a unique set of thermodynamic parameters characterizing both the thermal denaturation of hexokinase, and the binding equilibrium between D-glucose and the enzyme. It was found that the association constant is 9,800+/-1,500 M(-1) at pH 8.0. The binding of D-glucose is entropy-driven, since the binding enthalpy is zero. This finding is rationalized by a thermodynamic cycle for the association of two molecules in aqueous solution.


Asunto(s)
Glucosa/química , Hexoquinasa/química , Saccharomyces cerevisiae/enzimología , Rastreo Diferencial de Calorimetría , Calor , Concentración de Iones de Hidrógeno , Desnaturalización Proteica , Termodinámica
13.
J Biochem ; 122(2): 395-401, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9378719

RESUMEN

The existence of cold denaturation is now firmly demonstrated by its direct observation for several globular proteins in aqueous solution. But the physico-chemical explanation of this intriguing phenomenon is still unsatisfactory. In this paper we deepen our understanding of cold denaturation by taking advantage of the theoretical model developed by Ikegami and using thermodynamic data on the transfer to water of liquid N-alkyl amides. The analysis leads to the conclusion that the presence of water is fundamental to determine the existence of cold denaturation due to its strong energetic interaction with the amino acid residues previously buried in the protein's interior.


Asunto(s)
Frío , Desnaturalización Proteica , Termodinámica , Modelos Teóricos , Proteínas/química , Agua
14.
J Biochem ; 120(2): 292-300, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8889813

RESUMEN

The beta-glycosidase isolated from the extreme thermophilic archaeon Sulfolobus solfataricus, grown at 87 degrees C, is a tetrameric protein with a molecular mass of 240 kDa. This enzyme is barely active at 30 degrees C and has optimal activity, over 95 degrees C, at pH 6.5. Its thermal stability was investigated at pH 10.1 and 10.6 by means of functional studies, circular dichroism and differential scanning calorimetry. There was no evidence of thermal activation of the enzyme and the temperature-induced denaturation was irreversible and not well represented by the two-state transition model. A more complex process occurred, involving the dissociation and unfolding of subunits, and subsequent nonspecific association and/or aggregation. Denaturation temperature was around 85 degrees C, depending on protein concentration. The denaturation enthalpy change was between 7,500 and 9,800 kJ.mol-1, depending on the pH. The collapse of the native structure around 85 degrees C was confirmed by circular dichroism measurements and time-dependent activity studies. Finally, preliminary investigations were performed on the recombinant enzyme expressed in Escherichia coli.


Asunto(s)
Glicósido Hidrolasas/química , Sulfolobus/enzimología , Rastreo Diferencial de Calorimetría , Dicroismo Circular , Estabilidad de Enzimas , Escherichia coli/genética , Glicósido Hidrolasas/genética , Glicósido Hidrolasas/metabolismo , Concentración de Iones de Hidrógeno , Estructura Molecular , Peso Molecular , Conformación Proteica , Desnaturalización Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Sulfolobus/genética , Temperatura , Termodinámica
15.
Surgery ; 128(4): 589-96, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11015092

RESUMEN

BACKGROUND: This study compares the immediate postoperative outcomes in patients who undergo laparoscopic and open anterior lumbar spinal fusion and describes the learning curve associated with the performance of this procedure. METHODS: The charts of patients who underwent anterior lumbar spinal fusion between January 1995 and July 1999 were reviewed. Data pertaining to the operation and postoperative course were analyzed and compared. RESULTS: Eighty-nine patients underwent anterior lumbar spinal fusion. Fourteen patients were excluded; a full analysis was performed on the records of the remaining 75 patients. Fifty-five patients underwent an attempted laparoscopic procedure, and 20 patients underwent an open procedure. The conversion rate was 38% (21/55 patients) in the group who underwent the laparoscopic procedure. In the 34 patients whose laparoscopic procedure was completed, there was significantly less blood loss and shorter postoperative ileus, but the operative time was longer, when compared with patients who underwent the open procedure. The laparoscopic procedures performed in 1999 resulted in fewer conversions, less blood loss, and a shorter operating room time, when compared with the laparoscopic procedures in 1998. CONCLUSIONS: Laparoscopic anterior lumbar spinal fusion improves immediate postoperative results when compared with open anterior lumbar spinal fusion.


Asunto(s)
Laparoscopía/métodos , Vértebras Lumbares/cirugía , Fusión Vertebral/métodos , Adulto , Pérdida de Sangre Quirúrgica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias , Resultado del Tratamiento
16.
Biophys Chem ; 82(1): 69-79, 1999 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-17030340

RESUMEN

The present work tries to clarify the molecular origin of the poor solubility of benzene in water. The transfer of benzene from pure liquid phase into water is dissected in two processes: transfer from gas phase to pure liquid benzene; and transfer from gas phase to liquid water. The two solvation processes are analyzed in the temperature range 5-100 degrees C according to Lee's Theory. The solvation Gibbs energy change is determined by the balance between the work of cavity creation in the solvent, and the dispersive interactions of the inserted benzene molecule with the surrounding solvent molecules. The purely structural solvent reorganization upon solute insertion proves to be a compensating process. The analysis shows that the work of cavity creation is larger in water than in benzene, whereas the attractive energetic interactions are stronger in benzene than in water; this scenario is true at any temperature. Therefore, both terms act in the same direction, contrasting the transfer of benzene from pure liquid phase into water and determining its hydrophobicity.

17.
Biophys Chem ; 51(2-3): 193-9; discussion 199-202, 1994 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-7919032

RESUMEN

Determination of hydration parameters for the solute-solvent interactions of model peptide molecules can provide quantitative information on the factors affecting the folding and stability of proteins in aqueous solutions. Standard hydration enthalpies are calculated by combination of the standard sublimation and solution enthalpy data, experimentally determined. The results for some N-acetyl amino acid amides, assumed as model for peptides, are reported and the trend of hydration enthalpies with increasing complexity of the model molecules is discussed on the basis of the group additivity method. Further the direct proportionality between hydration enthalpy and non-polar accessible surface area (ASA) of each amino acid residue is emphasized. Finally it is pointed out that there exists a convergence temperature for the enthalpy associated with the hydration process of these model compounds and its value TH* = 93 +/- 7 degrees C is close to that found for small globular proteins (i.e. TH* = 100 +/- 6 degrees C). This finding can give some insights to clarify the emergence of convergence behaviour in the unfolding process.


Asunto(s)
Aminoácidos/química , Péptidos/química , Fenómenos Químicos , Química Física , Modelos Químicos , Estructura Molecular , Soluciones , Solventes , Termodinámica , Agua/química
18.
J Bone Joint Surg Am ; 75(7): 996-1003, 1993 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8335675

RESUMEN

Six patients were managed with gradual reduction of a deformity of the cervical spine, before operative stabilization, with use of a modified halo cast with adjustable distraction components that allowed the patient to sit and walk while the deformity was being corrected. The distraction components were constructed from the distractors, hinges, and connectors of an Ilizarov apparatus. The diagnoses were atlanto-axial subluxation secondary to rheumatoid arthritis, atlanto-axial rotatory subluxation secondary to juvenile rheumatoid arthritis, post-traumatic atlanto-axial rotatory subluxation, ankylosing spondylitis with an angulated fracture of the seventh cervical vertebra, atlanto-occipital and atlanto-axial subluxation secondary to familial cervical dysplasia, and cervicothoracic kyphosis secondary to laminectomy and radiation for astrocytoma. All of the deformities were corrected initially, but the deformity partially recurred in three patients: in the lower cervical area because of pseudarthrosis in one, and between the occiput and the first cervical vertebra after arthrodesis between the first and second cervical vertebrae in two. Complications included an infection at the site of the halo pin, which led to replacement of the pin (one patient); pressure sores under the body cast (two patients); dislodgment of the halo secondary to a fall, which necessitated reapplication of the halo (one patient); and pneumonia (one patient). Spinal distraction with halo-cast traction is a useful adjunct in the treatment of selected complex cervical and high thoracic deformities. Gradual three-dimensional correction may be obtained in a controlled fashion, while the patient is allowed out of bed to sit and walk.


Asunto(s)
Moldes Quirúrgicos , Vértebras Cervicales/cirugía , Tracción/métodos , Adulto , Anciano , Niño , Preescolar , Fijadores Externos , Femenino , Humanos , Cifosis/cirugía , Masculino , Recurrencia , Escoliosis/cirugía , Enfermedades de la Columna Vertebral/cirugía , Tortícolis/cirugía , Tracción/instrumentación
19.
J Bone Joint Surg Am ; 77(2): 190-6, 1995 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-7844124

RESUMEN

Acute spondylolytic spondylolisthesis was diagnosed after major trauma in five patients. The level of injury was between the third and fourth lumbar vertebrae in one patient and between the fifth lumbar and first sacral vertebrae in four. The initial spondylolisthesis was grade I in four patients and grade III in one. Four of the patients were initially managed non-operatively. The deformity did not progress in a five-year-old boy with grade-I spondylolisthesis who had been managed with immobilization in a body cast. The deformity progressed in two of the adolescents who had been managed non-operatively; the progression was from grade I to grade III in one of these patients and from grade III to grade V (spondyloptosis) in the other, in whom a cauda equina syndrome also developed. The latter patient was subsequently managed with posterior reduction and arthrodesis followed by an anterior arthrodesis, and the neurological deficits resolved. The deformity also progressed, from grade I to grade II over three years, in a fifty-seven-year-old woman who had been managed non-operatively. One patient who had a grade-I deformity was managed with immediate operative stabilization followed by immobilization in a thoracolumbosacral orthosis; the deformity did not progress. Although minor or repetitive trauma is often associated with spondylolysis, high-energy trauma may produce a more severe form of spondylolysis with spondylolisthesis. These deformities are more unstable, with instability similar to that of a fracture-dislocation, and they have a greater propensity to progress than the usual form of spondylolytic spondylolisthesis.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Vértebras Lumbares/lesiones , Fracturas de la Columna Vertebral/complicaciones , Espondilolistesis/complicaciones , Espondilolistesis/terapia , Enfermedad Aguda , Adolescente , Adulto , Reposo en Cama , Cauda Equina/lesiones , Preescolar , Progresión de la Enfermedad , Femenino , Fijación de Fractura/métodos , Humanos , Inmovilización , Fijadores Internos , Vértebras Lumbares/cirugía , Masculino , Persona de Mediana Edad , Síndromes de Compresión Nerviosa/etiología , Síndromes de Compresión Nerviosa/cirugía , Estudios Retrospectivos , Factores de Riesgo , Fusión Vertebral , Espondilolistesis/etiología , Espondilólisis/etiología , Espondilólisis/terapia , Resultado del Tratamiento
20.
Spine (Phila Pa 1976) ; 26(20): 2289-96, 2001 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-11598523

RESUMEN

STUDY DESIGN: Three cases of multiplanar congenital scoliosis corrected by a transpedicular eggshell osteotomy using frameless stereotactic guidance are reported. OBJECTIVE: To show an alternative surgical technique for correcting and fusing complex congenital spinal curves. SUMMARY OF BACKGROUND DATA: Children with congenital scoliosis can have progressive curves causing significant multiplanar deformities. In older children, traditional approaches to spinal corrective surgery including fusion in situ, convex growth arrest, and hemivertebra excision can achieve only limited corrections. METHODS: Three older patients who had congenital scoliosis with significant multiplanar curves underwent one-stage posterior transpedicular eggshell osteotomy. Three-dimensional reconstructive images and frameless stereotactic guidance were used for preoperative selection of osteotomy levels and accurate placement of pedicle screws. After completion of the osteotomy, closure was obtained with extension of the hips. RESULTS: The average coronal correction of the major curve was 28.7 degrees (range, 22-33 degrees ). The average correction of the plumb line or lateral displacement from the center of the trunk was 4.8 cm (range, 3-7.5 cm). A significant kyphotic deformity was corrected 38 degrees, and a pelvic tilt was reduced from 7 to 3 cm. CONCLUSIONS: One-stage posterior reduction eggshell osteotomy can be used to correct a sagittal and/or coronal congenital spinal curve imbalance. Frameless stereotactic guidance for solid pedicle screw fixation was essential to the achievement of rigid spinal stabilization before arthrodesis. Transpedicular eggshell osteotomy is a technique that should be considered for older patients who have congenital scoliosis with multiplanar spinal abnormalities.


Asunto(s)
Osteotomía/métodos , Escoliosis/cirugía , Fusión Vertebral/métodos , Técnicas Estereotáxicas , Adolescente , Niño , Humanos , Imagenología Tridimensional , Cifosis/diagnóstico por imagen , Cifosis/cirugía , Masculino , Radiografía , Escoliosis/congénito , Fusión Vertebral/instrumentación
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