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2.
Int J Pediatr Otorhinolaryngol ; 112: 6-9, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30055741

RESUMO

OBJECTIVE: To evaluate the relationship between the severity degree of OSA (apnea/hypopnea index AHI>1) and palatal area and volume, measured by 3D analysis of digital casts in Marfan children. METHODS: Twenty children with a clinical diagnosis of MS were recruited from a tertiary medical center. All the subjects underwent standard nocturnal polygraphy testing. Sixteen Marfan patients (7F,9 M; mean age 8.8yy ±â€¯1.5yy) with AHI>1 were enrolled. Marfan Group (MG) was compared with a control group (CG) of 17 children without Marfan syndrome (9F,8 M; mean age 8.5yy ±â€¯1.7yy) presenting with nose-breathing pattern. For each subject maxillary digital casts were taken and palatal area and volume were measured. Unpaired t-test was used to test significant differences between MG and CG for area and volume measurements. Pearson correlation coefficient (PCC) was used to measure the linear correlation between the degree of OSA (AHI index) and palatal volume and palatal area. RESULTS: 80% of Marfan children presented an AHI>1 and a diagnosis of OSA. MG presented statistically significant lower values of palatal surface area (662.68 mm2; P < 0.0001) and palatal volume (2578.1 mm3; P < 0.0001) with respect to CG (923.0 mm2 and 3756.6 mm3, respectively). Correlation analysis showed that AHI index had no linear correlation with palatal area (r = - 0,07) and with palatal volume (r = - 0,11). CONCLUSION: OSA is highly prevalent in children with Marfan's syndrome (80%). Marfan children present a reduction of palatal area and volume when compared to healthy subjects. OSA in Marfan children is not linear correlated to the palatal morphology and it shows a multifactorial aetiology.


Assuntos
Síndrome de Marfan/complicações , Palato/patologia , Índice de Gravidade de Doença , Apneia Obstrutiva do Sono/etiologia , Estudos de Casos e Controles , Criança , Feminino , Humanos , Masculino , Síndrome de Marfan/patologia , Apneia Obstrutiva do Sono/diagnóstico
3.
Oral Implantol (Rome) ; 10(3): 289-294, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29285332

RESUMO

OBJECTIVE: The purpose of the study was to analyze the association between dento-skeletal malocclusions, ocular motility, and convergence disorders in growing subjects. MATERIALS AND METHODS: 84 subjects (49 males, 35 females) with a mean age of 7.3±1.7 years were enrolled in a screening procedure for celiac disease at the Department of Gastroenterology of the University of Rome "Tor Vergata". Each child underwent an orthodontic, orthoptic, and ophtalmological examination. Pearson's Chi-Square test with Yates' correction and Fisher's exact test were conducted to assess the association between orthoptic defects and malocclusions (p<0.05). RESULTS: Ocular motility disorders were present in 44.9% of males and in 57.1% of females, while convergence defects were present in 10.2% of males and in 2.9% of females. Ocular motility disorders were more frequent in subjects with Angle Class III malocclusion (66.7%) than in subjects with Angle Class II (59.1%) and Class I (45.8%) malocclusion. Convergence defects were equally frequent in Angle Class I and Class II malocclusion (5.1%), while none subject presenting with Angle Class III malocclusion exhibited convergence defects. A statistically significant correlations was found between ocular motility disorders and unilateral cross-bite with midline deviation. CONCLUSION: Ocular motility defects had a significant greater prevalence in subjects presenting with unilateral cross-bite and midline deviation. The importance of role of orthodontic diagnosis among interdisciplinary treatment in growing children should be recognized.

4.
BMC Oral Health ; 17(1): 62, 2017 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-28284207

RESUMO

BACKGROUND: To analyze the prevalence and associations between dental anomalies detectable on panoramic radiographs in a sample of non-orthodontic growing subjects. METHODS: For this cross-sectional study, digital panoramic radiographs of 5005 subjects were initially screened from a single radiographic center in Rome. Inclusion criteria were: subjects who were aged 8-12 years, Caucasian, and had good diagnostic quality radiographs. Syndromic subjects, those with craniofacial malformation, or orthodontic patients were excluded and this led to a sample of 4706 subjects [mean (SD) age = 9.6 (1.2) years, 2366 males and 2340 females]. Sample was subsequently divided into four subgroups (8, 9, 10, and 11-12 year-old groups). Two operators examined panoramic radiographs to observe the presence of common dental anomalies. The prevalence and associations between dental anomalies were also investigated. RESULTS: The overall prevalence of dental anomalies was 20.9%. Approximately, 17.9% showed only one anomaly, 2.7% two anomalies, while only 0.3% had more than two anomalies. The most frequent anomalies were the displacement of maxillary canine (7.5%), hypodontia (7.1%), impacted teeth (3.9%), tooth ankylosis (2.8%), and tooth transposition (1.4%). The lower right second premolar was the most frequent missing teeth; 3.7% had only one tooth agenesis, and 0.08% had six or more missing tooth (Oligodontia). Mesiodens was the most common type of supernumerary tooth (0.66%). Two subjects had taurodontic tooth (0.04%). Tooth transpositions and displacement of maxillary canine were seen in 1.4 and 7.5%, retrospectively (approximately 69 and 58% were in the 8 and 9 year-old groups, retrospectively). Significant associations were detected between the different dental anomalies (P < .05). CONCLUSIONS: The results of our study revealed significant associations among different dental anomalies and provide further evidences to support common etiological factors.


Assuntos
Anormalidades Dentárias/epidemiologia , Anodontia/epidemiologia , Criança , Estudos Transversais , Dente Canino/anormalidades , Cavidade Pulpar/anormalidades , Feminino , Humanos , Itália/epidemiologia , Masculino , Má Oclusão/epidemiologia , Prevalência , Radiografia Panorâmica , Erupção Ectópica de Dente/epidemiologia , Dente Impactado/epidemiologia , Dente Supranumerário/epidemiologia
5.
Eur J Paediatr Dent ; 16(3): 217-20, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26418925

RESUMO

AIM: To analyse the dental effects on digital dental casts in subjects with Class III malocclusion treated with bonded Rapid Maxillary Expansion and Facial Mask (RME/FM). MATERIALS AND METHODS: A study group sample (SG) of 29 subjects (13 females and 16 males) and mean age of 7.4 years (SD 1.2 years) was selected. A bonded RME was placed and activated 1/4 of a turn per day until overcorrection of the transverse width. At the end of expansion, patients were given FMs and treated at least to a positive overjet. The SG was compared with a control group (CG) of 21 prepubertal subjects (9 females; 12 males) presenting with normal occlusion and mean age of 7.9 years (SD 1.6 years). For each subject of the SG and CG initial (pretreatment, T1) and final (post-treatment, T2) digital dental casts were available. Significant in between-group differences were tested with the Student's t-test. RESULTS: The transverse dimension of the upper arch was significantly greater in SG vs. CG (IMAW: +2.6 mm; ICAW: +3.1 mm). Anterior arch length and arch depth were significantly smaller in SG when compared with CG (AAL: -3.2 mm, AD: -3.4 mm) at the end of therapy. CONCLUSION: The orthopaedic treatment with bonded RME/FM produced in subjects treated in the deciduous or early mixed dentition a significant expansion of the maxillary arch and mesialisation of the posterior teeth with a reduction of the arch depth.


Assuntos
Técnica de Fundição Odontológica , Má Oclusão Classe III de Angle/terapia , Máscaras , Técnica de Expansão Palatina , Criança , Feminino , Humanos , Masculino
6.
Int J Biol Macromol ; 63: 225-32, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24291767

RESUMO

Protein aggregation is often associated with conformational and structural changes of secondary structure elements that may lead to exposure of some specific residues. Data obtained in our experimental work indicate that trehalose (1.0M) effectively prevent thermal inactivation and aggregation of lysozyme. In fact, following heat treatment, lysozyme generates insoluble aggregates which are almost completely absent in the samples incubated in the presence of the disaccharide. The experimental approach consists in studying FTIR spectra of intrinsic chromophores and VT-NMR measurements on lysozyme water mixtures in the presence of trehalose. FTIR measurements suggest that in the presence of 1.0 M of trehalose there is a clear decrease in the loss of α-helix structure and in the formation of intermolecularly aggregated structures. Electrospray ionization mass spectrometry (ESI-MS) was employed to characterize protein structural transition, highlighting as trehalose remarkably influenced solvent accessibility to the amide peptide backbone upon heat treatment, consequentially decreasing local protein environment changes. Complementary informations are also obtained by UV-vis spectroscopy measurements, Congo Red binding and activity determinations.


Assuntos
Muramidase/química , Estabilidade Proteica , Estrutura Secundária de Proteína , Trealose/química , Animais , Galinhas , Espectroscopia de Ressonância Magnética , Micrococcus/química , Muramidase/metabolismo , Espectrometria de Massas por Ionização por Electrospray , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Trealose/metabolismo
7.
Appl Biochem Biotechnol ; 172(2): 854-66, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24122710

RESUMO

Ornithine carbamoyltransferase folding/unfolding is a complex and not completely understood process. Our experimental results suggest that ornithine carbamoyltransferase interacts in a completely different way with urea and guanidine hydrochloride. In fact, we noticed that, increasing concentration from 0.0 to 8.0 M of the two additives, the enzyme follows a simple one-step transition mechanism in the presence of guanidine hydrochloride, with two macroscopic states (the native and the denatured one) significantly populated, whereas in the presence of urea a lot of different protein states can be detected and analyzed. Circular dichroism and UV-visible spectroscopy reveal a similar mechanism of perturbation at high temperature, with opening of hydrophobic core and a significant loss in α-helix structure in the presence of guanidine hydrochloride that cannot be found in the presence of urea.


Assuntos
Guanidina/farmacologia , Ornitina Carbamoiltransferase/metabolismo , Dobramento de Proteína/efeitos dos fármacos , Ureia/farmacologia , Animais , Dicroísmo Circular , Eletroforese em Gel de Ágar , Ativação Enzimática/efeitos dos fármacos , Fluorescência , Cinética , Estrutura Secundária de Proteína , Tubarões , Espectrofotometria Ultravioleta , Termodinâmica
8.
Eur J Paediatr Dent ; 14(4): 309-13, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24313584

RESUMO

AIM: The aim of this study was to assess the prevalence of oral habits in an Albanian population of schoolchildren. STUDY DESIGN: A sample of 2617 subjects, aged 7-15, was examined by clinical observation without radiograms. The sample comprised 1257 males and 1360 females, with no history of orthodontic treatment. Aestethical frontal and profile analysis, intraoral and functional analysis were performed. STATISTICS: Gender and age differences were compared by chi-square test. The relationship between malocclusions and oral habits was assessed by t-test and the level of significance was assessed at 0.01. RESULTS: The findings indicated that oral habits were present in 2225 subjects (85.0%), 1103 males (87.7%) and 1121 females (82.4%); the most frequent oral habit was pacifier sucking (30%) and it was mostly present in the 7-11 years group. It was observed a significant correlation between oral habits and dental malocclusions, open bite, altered overjet and maxillary contraction. CONCLUSION The high number of oral habits observed in the studied sample suggest that prevention strategies adopted in other countries could be successfully integrated in the development of an effective national programme in Albania aimed at reducing malocclusion risk factors.


Assuntos
Sucção de Dedo/efeitos adversos , Má Oclusão/etiologia , Respiração Bucal/epidemiologia , Chupetas/efeitos adversos , Hábitos Linguais/efeitos adversos , Adolescente , Albânia/epidemiologia , Distribuição de Qui-Quadrado , Criança , Feminino , Hábitos , Humanos , Lactente , Masculino , Má Oclusão/epidemiologia , Respiração Bucal/complicações , Mordida Aberta/epidemiologia , Mordida Aberta/etiologia , Chupetas/estatística & dados numéricos , Prevalência
9.
J Orofac Orthop ; 74(6): 468-79, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24158584

RESUMO

BACKGROUND AND OBJECTIVE: In this study we assessed the influence of rapid maxillary expansion (RME) on the intraosseous vertical position and inclination of the impacted incisors diagnosed at an early developmental stage on panoramic radiographs and subsequently treated by surgical removal of the obstacle. MATERIALS AND METHODS: Following surgical removal of the obstacles to incisor eruption (T1), a group of 34 subjects (mean age 8 years 11 months ± 11 months) underwent RME, while a group of 28 subjects (mean age 9 years 1 month ± 1 year) was monitored after surgery without further treatment. At T2 (on average 10 months after T1), the prevalence rate of subjects with erupted incisors was recorded. The measurements were taken on the panoramic radiographs at T1 and T2 to assess the vertical position and angulation of delayed unerupted incisors. RESULTS: At T2, impacted incisors erupted in 82.4% of the patients in the RME group versus 39.3% of those in the monitored group (χ(2) =8.45, p<0.001). All the patients treated with RME showed an improvement in the vertical and angular position of the unerupted teeth. Logistic regression revealed RME therapy as the only significant predictive variable (p<0.001) for successful eruption of the delayed incisors at T2. CONCLUSION: RME in early mixed dentition appears to be an effective procedure to increase the prevalence rate of impacted maxillary incisor eruption.


Assuntos
Incisivo/diagnóstico por imagem , Técnica de Expansão Palatina , Radiografia Panorâmica/métodos , Erupção Ectópica de Dente/terapia , Dente Impactado/terapia , Dente Supranumerário/terapia , Criança , Feminino , Humanos , Estudos Longitudinais , Masculino , Ortodontia Interceptora/métodos , Radiografia Dentária/métodos , Erupção Ectópica de Dente/diagnóstico por imagem , Dente Impactado/diagnóstico por imagem , Dente Supranumerário/diagnóstico por imagem , Resultado do Tratamento
11.
Dentomaxillofac Radiol ; 42(2): 71798010, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22996394

RESUMO

OBJECTIVE: This prospective study evaluated the density of the midpalatal and transverse sutures as assessed by low-dose CT before rapid maxillary expansion (T0), at the end of active expansion (T1) and after a retention period of 6 months (T2). METHODS: The study sample comprised 17 pre-pubertal subjects (mean age 11.2 years) with constricted maxillary arches. Total amount of expansion was 7 mm in all subjects. Multislice low-dose CT scans were taken at T0, T1 and T2. On the axial CT scanned images six regions of interest (ROIs) were placed along the midpalatal and transverse sutures and two in maxillary and palatal bony areas. Density was measured in Hounsfield units. Mann-Whitney U test and Friedman analysis of variance with post hoc tests were used (p < 0.05). RESULTS: The three ROIs in the midpalatal suture showed a significant decrease in density from T0 to T1, a significant increase from T1 to T2 and a lack of statistically significant differences from T0 to T2. Both ROIs located in the transverse suture showed a significant decrease in density from T0 to T1, followed by a non-significant increase in density from T1 to T2. CONCLUSIONS: At the end of the active phase of expansion a significant reduction in density along the midpalatal and transverse sutures was observed in all subjects. The sutural density of the midpalatal suture at T2 indicated reorganization of the midpalatal suture while the density along the transverse suture increased without reaching the pre-treatment values, possibly due to different morphology between midpalatal and transverse sutures.


Assuntos
Densidade Óssea/fisiologia , Suturas Cranianas/diagnóstico por imagem , Imageamento Tridimensional/métodos , Maxila/diagnóstico por imagem , Tomografia Computadorizada Multidetectores/métodos , Técnica de Expansão Palatina , Absorciometria de Fóton/métodos , Adolescente , Criança , Arco Dental/diagnóstico por imagem , Feminino , Seguimentos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Má Oclusão/diagnóstico por imagem , Má Oclusão/terapia , Palato/diagnóstico por imagem , Estudos Prospectivos
12.
Eur J Paediatr Dent ; 13(3): 215-8, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22971259

RESUMO

AIM: The aim of this prospective study was to evaluate the effects of rapid maxillary expansion (RME) on the palatal area as assessed by low-dose CT before treatment (T0), at the end of active expansion (T1) and after a retention period of 6 months (T2). MATERIALS AND METHODS: The study sample comprised 17 prepubertal subjects (mean age 11.2 years) with constricted maxillary arches. Total amount of expansion was 7 mm in all subjects. Multi-slice low-dose CT scans were taken at T0, T1, and T2. On axial CT scanned images a circle line corresponding to the palatal area was drawn and the area inside the circle registered at all three observation times. The area was measured in mm². Statistical comparisons were carried out with Friedman test with post-hoc tests (P<0.05). RESULTS: The palatal area showed a significant increase from T0 to T1 and from T0 to T2 as a consequence of the opening of the midpalatal suture after RME. CONCLUSION: Opening the midpalatal suture by using orthopedic forces allowed to extend the area of the maxilla. After a 6-months retention period the palatal area demonstrated a stable increase due to a bone deposition along the midpalatal suture in both the anterior and posterior parts of the maxilla.


Assuntos
Técnica de Expansão Palatina , Palato Duro/anatomia & histologia , Palato Duro/diagnóstico por imagem , Criança , Feminino , Humanos , Masculino , Estudos Prospectivos , Estatísticas não Paramétricas , Tomografia Computadorizada por Raios X
13.
Eur J Paediatr Dent ; 12(1): 17-20, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21434730

RESUMO

AIM: The aim of this study was to analyse skeletal, dental and arch morphology in a group of subjects with dental agenesis and to compare it with a control group. STUDY DESIGN: 2 groups of subjects were selected: an experimental group (84 patients) with tooth agenesis and a control group (84 subjects) without tooth agenesis. MATERIALS AND METHODS: Skeletal, dental, morphological and aesthetic parameters were studied using lateral and posteroanterior cephalograms and dental casts. RESULTS: Transversal and sagittal measurements showed a significant decrease in maxillary size associated with tooth agenesis in the agenesis group. No changes were observed in mandibular size. CONCLUSION: Orthodontists should consider that patients with agenesis present altered craniofacial dimensions.


Assuntos
Anodontia/complicações , Anormalidades Craniofaciais/complicações , Má Oclusão/complicações , Mandíbula/patologia , Maxila/patologia , Desenvolvimento Maxilofacial/fisiologia , Adolescente , Anodontia/patologia , Estudos de Casos e Controles , Cefalometria , Criança , Anormalidades Craniofaciais/patologia , Arco Dental/anatomia & histologia , Feminino , Humanos , Masculino , Má Oclusão/patologia , Modelos Dentários , Odontometria , Valores de Referência
14.
G Chir ; 30(4): 169-72, 2009 Apr.
Artigo em Italiano | MEDLINE | ID: mdl-19419620

RESUMO

Reporting their personal experience, the authors focus on characteristics and causes of recurrence, either after traditional surgery or with tension-free technique. They describe difficulties and advantages in open interventions and laparoscopic ones. Facing a relapse it's convenient to assume an "eclectic" behaviour, thinking both of general and specific single patient anatomo-pathologic features.


Assuntos
Hérnia Inguinal/cirurgia , Seguimentos , Humanos , Laparoscopia , Recidiva , Reoperação , Fatores de Tempo , Resultado do Tratamento
15.
Int J Biol Macromol ; 45(2): 120-8, 2009 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-19409412

RESUMO

In the present article the influence of salts and additives, such as trehalose, NaCl, ornithine, sodium phosphate and ammonium sulphate, on ornithine carbamoyltransferase (OCTase) is investigated in order to study the OCTase stabilization process as a function of solutes and to point out the fundamental role played by an enhancement of hydrophobic interactions. The synergic use of different techniques, such as neutron spectroscopy, UV-vis spectroscopy, activity and thermal measurements, allows to highlight the cosolute capability to avoid thermal inactivation, to induce important changes in secondary and tertiary enzyme structure and to stabilize biological macromolecules.


Assuntos
Ornitina Carbamoiltransferase/química , Ornitina Carbamoiltransferase/metabolismo , Sais/farmacologia , Animais , Cisteína , Elasmobrânquios/anatomia & histologia , Ativação Enzimática/efeitos dos fármacos , Estabilidade Enzimática/efeitos dos fármacos , Cinética , Fígado/enzimologia , Análise Espectral , Temperatura , Termodinâmica , Titulometria
16.
Vet Pathol ; 46(2): 329-33, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19261647

RESUMO

In this study, an acquired pigmentation in Nero Siciliano pigs is reported and evaluated by a multidisciplinary approach to support the hypothesis it is caused by an ingested material. A total of 18 pigs were studied. Fourteen conventionally slaughtered animals showed black discoloration of lymph nodes. The lymph nodes were normal in size and shape but showed diffuse black discoloration of the cortex and medulla. Melanosis of fat was observed in 2 animals and was limited to the back. Histochemical tests performed on tissues enabled identification and differentiation of the pigment. Immunohistochemical staining for macrophage markers showed macrophages containing a variable amount of melanin-like granules. Stains for human melanoma, as well as S-100 protein, did not show any reaction. Histochemical methods for tyrosinase showed colorimetric patterns that confirmed the presence of the enzyme in acorns. The activity was mostly latent. A high tannin content was demonstrated, reaching about 76% of the total phenolic compounds. Our data, and the well-known steps on melanin formation, permit us to hypothesize that swine tyrosinase could act on phenolic substances found in acorns. Tyrosinase activation could take place in genetically predisposed swine after acorns are eaten, and this event could increase the biosynthesis and the anomalous storage of melanin.


Assuntos
Ração Animal , Melanose/induzido quimicamente , Quercus , Doenças dos Suínos/patologia , Animais , Dieta/veterinária , Linfonodos/patologia , Melanose/patologia , Suínos
17.
Physiol Res ; 57(4): 621-629, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-17705675

RESUMO

The effects of gemfibrozil (GFZ), an antihyperlipidemic agent, on the anionic transport of the human red blood cells (RBC) during the oxygenation-deoxygenation cycle were examined. Gemfibrozil clearly plays a role in the modulation of the anionic flux in erythrocytes; in fact it causes a strong increment of anions transport when the RBCs are in the high-oxygenation state (HOS). Such an effect is remarkably reduced in the low-oxygenation state (LOS). With the aim of identifying the dynamics of fibrate action, this effect has been investigated also in human ghost and chicken erythrocytes. These latter, in fact, are known to possess a B3 (anion transporter or Band 3) modified at the cytoplasmic domain (cdb3) which plays a significant role in the metabolic modulation of red blood cells. The results were analyzed taking into account the well-known interactions between fibrates and both conformational states of hemoglobin i.e. the T state (deoxy-conformation) and the R state (oxy-conformation). The effect of gemfibrozil on anionic influx appears to be due to a wide interaction involving a "multimeric" Hb-GFZ-cdb3 macromolecular complex.


Assuntos
Eritrócitos/metabolismo , Genfibrozila/farmacologia , Hipolipemiantes/farmacologia , Consumo de Oxigênio/fisiologia , Sulfatos/sangue , Adulto , Soluções Tampão , Calibragem , Relação Dose-Resposta a Droga , Membrana Eritrocítica , Eritrócitos/efeitos dos fármacos , Hemoglobinas/metabolismo , Humanos , Técnicas In Vitro , Indicadores e Reagentes , Cinética , Pessoa de Meia-Idade , Consumo de Oxigênio/efeitos dos fármacos , Fosfoproteínas Fosfatases/metabolismo , Conformação Proteica , Vanadatos/farmacologia
18.
Physiol Res ; 57(1): 49-54, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-17298204

RESUMO

During vertebrate evolution, structural changes in red blood cells (RBC) and hemoglobin (Hb), have probably resulted in the importance of blood carbon dioxide transport. The chloride/bicarbonate exchange across the RBC membrane, which is an integral part of the blood CO(2) transport process in vertebrates, has been examined on two different species of teleost fish, Euthynnus alletteratus and Thunnus thynnus, at several oxygenation states of erythrocyte HOS (high-oxygenation state, about 90 % of saturation) and LOS (low-oxygenation state, about 15 % of saturation). The results were compared with those observed in human RBC under the same experimental conditions and with the chicken (Gallus gallus) erythrocytes, which have particular modifications at the N-terminus of the band 3 protein (B3). In fish the kinetic measurements have shown a different anion transport in several oxygenation states of erythrocytes, indicating that also at lower levels of vertebrate evolution there exists a modulation of the anionic flow affected by oxygen. The functional correlation of anion transport to changes of parts of the hemoglobin sequence responsible for alterations in the interactions with the cytoplasmic domain of band 3 protein (cdb3) allowed us to suggest a hypothesis about fish physiology. The highest values of kinetic measurements observed in fish have been attributed to the metabolic need of the RBC in response to the removal of CO(2) that in teleosts is also of endogenous origin.


Assuntos
Proteína 1 de Troca de Ânion do Eritrócito/fisiologia , Dióxido de Carbono/sangue , Eritrócitos/metabolismo , Proteínas de Peixes/fisiologia , Transporte de Íons/fisiologia , Atum/metabolismo , Adulto , Animais , Galinhas , Hemoglobinas/química , Hemoglobinas/metabolismo , Humanos , Pessoa de Meia-Idade , Oxigênio/sangue , Especificidade da Espécie
19.
Physiol Res ; 55(6): 675-688, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16497106

RESUMO

Lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) electrophoretic tissue patterns of two different orders of Elasmobranchii: Carchariniformes (Galeus melanostomus and Prionace glauca) and Squaliformes (Etmopterus spinax and Scymnorinus licha) were studied. The number of loci expressed for these enzymes was the same of other elasmobranch species. Differences in tissue distribution were noted in LDH from G. melanostomus due to the presence of an additional heterotetramer in the eye tissue. There were also differences in MDH. In fact, all the tissues of E. spinax and G. melanostomus showed two mitochondrial bands. Major differences were noted in the number of isozymes detected in the four compared elasmobranchs. The highest polymorphism was observed in E. spinax and G. melanostomus, two species that live in changeable environmental conditions. The resistance of isozymes after urea treatment was examined; the resulting patterns showed a quite good resistance of the enzymes, higher for LDH than MDH, also at urea concentration much greater than physiological one. These results indicated that the total isozyme resistance can be considered higher in urea accumulators (such as elasmobranchs) than in the non-accumulators (such as teleosts).


Assuntos
Adaptação Fisiológica , Elasmobrânquios/metabolismo , Proteínas de Peixes/metabolismo , L-Lactato Desidrogenase/metabolismo , Malato Desidrogenase/metabolismo , Ureia/química , Animais , Encéfalo/enzimologia , Eletroforese em Gel de Poliacrilamida , Evolução Molecular , Olho/enzimologia , Proteínas de Peixes/química , Isoenzimas/metabolismo , L-Lactato Desidrogenase/química , Fígado/enzimologia , Malato Desidrogenase/química , Músculos/metabolismo , Miocárdio/enzimologia , Filogenia , Conformação Proteica , Desnaturação Proteica , Ureia/metabolismo
20.
Physiol Res ; 54(4): 395-402, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15588155

RESUMO

The ability of activity modulators of ornithine transcarbamoylase (OCT) from the liver of the thresher shark Alopias vulpinus to stabilize the enzyme against thermal denaturation was investigated in the tri-buffer at pH 7.8, at temperatures ranging from 60 to 70 (o)C, in the presence of polyhydroxylic molecules such as glycerol and sugars. The study indicated that in the presence of 0.5 M sugars and 1.6 M glycerol in the preincubation medium the OCT activity increases. When trehalose is introduced directly in the reaction mixture in a range of concentration of 0.25-0.5 M, the activity is lower than that with maltose, glycerol and buffer alone. Kinetic data for carbamoyl phosphate and ornithine with and without maltose and glycerol are similar, whereas trehalose increases the kinetic values. Arrhenius plots show an increase of activation energy due to trehalose, whereas values obtained with maltose and glycerol are similar to the control.


Assuntos
Carboidratos/farmacologia , Glicerol/farmacologia , Ornitina Carbamoiltransferase/química , Tubarões/metabolismo , Animais , Metabolismo Energético/fisiologia , Ativação Enzimática/fisiologia , Meia-Vida , Temperatura Alta , Concentração de Íons de Hidrogênio , Cinética , Fígado/enzimologia , Maltose/farmacologia , Desnaturação Proteica/fisiologia , Sacarose/farmacologia , Trealose/farmacologia
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