RESUMO
Cancer has been a significant threat to human health and well-being, posing the biggest obstacle in the history of human sickness. The high death rate in cancer patients is primarily due to the complexity of the disease and the wide range of clinical outcomes. Increasing the accuracy of the prediction is equally crucial as predicting the survival rate of cancer patients, which has become a key issue of cancer research. Many models have been suggested at the moment. However, most of them simply use single genetic data or clinical data to construct prediction models for cancer survival. There is a lot of emphasis in present survival studies on determining whether or not a patient will survive five years. The personal issue of how long a lung cancer patient will survive remains unanswered. The proposed technique Naive Bayes and SSA is estimating the overall survival time with lung cancer. Two machine learning challenges are derived from a single customized query. To begin with, determining whether a patient will survive for more than five years is a simple binary question. The second step is to develop a five-year survival model using regression analysis. When asked to forecast how long a lung cancer patient would survive within five years, the mean absolute error (MAE) of this technique's predictions is accurate within a month. Several biomarker genes have been associated with lung cancers. The accuracy, recall, and precision achieved from this algorithm are 98.78%, 98.4%, and 98.6%, respectively.
Assuntos
Heurística , Neoplasias Pulmonares , Humanos , Teorema de Bayes , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Aprendizado de Máquina , AlgoritmosRESUMO
OBJECTIVE: The aim of this study was to review the pattern of ankle fractures sustained by patients brought to the Emergency Department at Ysbyty Gwynedd from The Snowdonia National Park. MATERIALS AND METHODS: The study group included all patients with ankle fractures on the mountain medicine database between March 2004 and December 2006. The presence of talar shift and comminution of the medial malleolus was noted. The pattern of fractures were analysed and compared with the literature. Radiographs were obtained for 20 casualties. RESULTS: 70% of these were injured whilst hill walking. Open fractures represented 12% of injuries. 75% of fractures required operative fixation. Weber B injuries were the commonest followed by Weber C and A. Talar shift was seen in 80% of the cases and 45% showed comminution of the medial malleolus. CONCLUSIONS: In our case series we observed a high proportion of open and unstable ankle fractures, with the majority treated by operative fixation. The high rate of comminution of the medial malleolus has previously not been reported in the literature and has the potential of making operative fixation technically difficult. Encouraging the use of walking poles particularly at the time of descending may help to reduce the incidence of ankle fractures in hill walkers.
Assuntos
Aeronaves , Traumatismos do Tornozelo/epidemiologia , Serviço Hospitalar de Emergência/estatística & dados numéricos , Fraturas Ósseas/epidemiologia , Montanhismo , Adolescente , Adulto , Traumatismos do Tornozelo/cirurgia , Criança , Feminino , Fraturas Ósseas/cirurgia , Fraturas Expostas/epidemiologia , Fraturas Expostas/cirurgia , Humanos , Instabilidade Articular/epidemiologia , Instabilidade Articular/cirurgia , Masculino , Pessoa de Meia-Idade , País de Gales , Adulto JovemRESUMO
The aim of this article is to outline some of the factors practitioners should take into consideration when planning optimal smile aesthetics. The components of the smile that will be discussed include the smile are, incisor/gingival display, smile width, gingival aesthetics, tooth proportionality/symmetry, contacts/connectors/embrasures and the dental midlines.
RESUMO
Participation in sport carries an increased risk of sustaining dental trauma which can be reduced by the use of a mouthguard. Mouthguards work by dissipating the force of impact, thus reducing the force which is transferred to the dentition. There are different types of mouthguard available which vary in design, costs and the level of protection provided. This article aims to review the use of mouthguards in sport, the common barriers to their use and also the different types of mouthguards and their characteristics.
Assuntos
Traumatismos em Atletas/prevenção & controle , Protetores Bucais , Traumatismos Dentários/prevenção & controle , Desenho de Equipamento , HumanosRESUMO
A retrospective cohort study was set up to analyse the prevalence and treatment of obstructive sleep apnoea (OSA) in relation to the severity of the deformity in patients with craniofacial microsomia (CFM). This study included a population of 755 patients with CFM from three craniofacial centres. Medical charts were reviewed for severity of the deformity, types of breathing difficulty, age at which breathing difficulty first presented, treatment for OSA, and treatment outcome. In total, 133 patients (17.6%) were diagnosed with OSA. Patients with Pruzansky IIB/III classification or bilateral craniofacial microsomia were significantly more often diagnosed with OSA than unilaterally affected patients of Pruzansky I/IIA classification. The initial treatment of OSA consisted of adenotonsillectomy, tracheotomy, or non-invasive positive pressure ventilation. Thirty-seven patients received more than one treatment (range 1-3). In this study, the prevalence of OSA in patients with CFM was higher than the prevalence in the healthy population described in the literature. Although several treatment modalities are available for the treatment of OSA in patients with CFM, treatment should be individualized and based on clinical symptoms, the severity of the deformity, and comorbidities.
Assuntos
Síndrome de Goldenhar/complicações , Apneia Obstrutiva do Sono/etiologia , Apneia Obstrutiva do Sono/terapia , Adolescente , Adulto , Boston/epidemiologia , Criança , Pré-Escolar , Terapia Combinada , Feminino , Síndrome de Goldenhar/epidemiologia , Humanos , Lactente , Recém-Nascido , Londres/epidemiologia , Masculino , Países Baixos/epidemiologia , Estudos Retrospectivos , Índice de Gravidade de Doença , Apneia Obstrutiva do Sono/epidemiologia , Resultado do TratamentoRESUMO
BACKGROUND: Procaine activates limbic structures in animals. In humans, acute intravenous administration of procaine yields emotional and psychosensory experiences and temporal lobe fast activity. We studied procaine's acute effects on cerebral blood flow (CBF) in relationship to clinical responses. METHODS: Cerebral blood flow was assessed by positron emission tomography with oxygen-15-labeled water in 32 healthy volunteers. Data were analyzed with statistical parametric mapping and magnetic resonance imaging-directed regions of interest. RESULTS: Procaine increased global CBF and, to a greater extent, anterior paralimbic CBF. Subjects with intense procaine-induced fear compared with those with euphoria had greater increases in left amygdalar CBF. Absolute and normalized left amygdalar CBF changes tended to correlate positively with fear and negatively with euphoria intensity. Procaine-induced visual hallucinations appeared associated with greater global and occipital CBF increases. Absolute occipital CBF increases appeared to correlate positively with visual hallucination intensity. CONCLUSIONS: Procaine increased anterior paralimbic CBF, and different clinical responses appeared to be associated with different patterns of CBF changes.
Assuntos
Circulação Cerebrovascular/efeitos dos fármacos , Emoções/fisiologia , Sistema Límbico/irrigação sanguínea , Procaína/farmacologia , Sensação/fisiologia , Lobo Temporal/irrigação sanguínea , Adolescente , Adulto , Percepção Auditiva/efeitos dos fármacos , Emoções/efeitos dos fármacos , Feminino , Alucinações/induzido quimicamente , Humanos , Sistema Límbico/efeitos dos fármacos , Sistema Límbico/fisiologia , Masculino , Pessoa de Meia-Idade , Transtornos do Humor/etiologia , Sensação/efeitos dos fármacos , Lobo Temporal/efeitos dos fármacos , Lobo Temporal/fisiologia , Percepção Visual/efeitos dos fármacosRESUMO
Hypodontia is a frequently encountered condition within general dental practice. Its successful management involves the interplay of a number of clinicians. The general dental practitioner plays a key role in the management of patients. The aim of this short article is to outline some of the principles of the multidisciplinary management of hypodontia with an emphasis on orthodontic treatment.
Assuntos
Anodontia/terapia , Ortodontia/métodos , Equipe de Assistência ao Paciente , HumanosRESUMO
The total circulating osteocalcin and ratio of inactive (noncarboxylated; GLU) to active (carboxylated; GLA) form of circulating osteocalcin were measured in patients receiving long term warfarin treatment (n = 20), age-matched control patients not receiving warfarin treatment (n = 10), and normal subjects before and after the administration of 30 mg warfarin (n = 7). There was no significant difference in the total osteocalcin concentrations between the control patients and the patients receiving long term warfarin treatment, and it did not significantly change after warfarin ingestion in the normal subjects. The GLU/GLA ratio was significantly increased (P less than 0.002) in the patients receiving long term warfarin treatment compared with that in the control patients. There was a significant increase (P less than 0.01) in the GLU/GLA ratio after warfarin ingestion in the normal subjects. This study demonstrates that osteocalcin carboxylation in humans is a vitamin K-dependent process and that circulating osteocalcin is structurally altered by warfarin administration. This finding has pathophysiological implications for the fetal warfarin embryopathy syndrome, bone disease associated with chronic liver diseases, and possibly for osteoporosis, in which vitamin K deficiency has been implicated.
Assuntos
Ácido 1-Carboxiglutâmico/sangue , Proteínas de Ligação ao Cálcio/sangue , Vitamina K/sangue , Varfarina/farmacologia , Adulto , Idoso , Feminino , Glutamatos/sangue , Ácido Glutâmico , Humanos , Masculino , Pessoa de Meia-Idade , OsteocalcinaRESUMO
Thirty-six patients with primary biliary cirrhosis (PBC) receiving calcium and calciferol supplements (100,000 IU monthly by im injection) were investigated for their calcium, vitamin D, PTH, and osteocalcin status. The corrected plasma calcium concentrations in PBC patients were significantly greater than those in normal subjects. While the mean serum 25-hydroxycholecalciferol and 1,25-dihydroxyvitamin D concentrations in these patients were similar to those in normal subjects, the mean serum PTH concentration was significantly greater, and it was supranormal in 11 patients. Three patients had elevated corrected calcium concentrations; 1 of them had a concomitant increase in ionized calcium and a supranormal PTH level, and another had a high normal PTH. Ionized calcium concentrations were normal in the rest. Serum osteocalcin concentrations were significantly lower in the patients compared with those in normal subjects. These results indicate that PTH concentrations are frequently elevated in PBC patients despite adequate vitamin D supplementation and normal or even supranormal plasma calcium concentrations. Nonsuppression of PTH concentrations and autonomy of PTH secretion suggest that vitamin D deficiency and secondary hyperparathyroidism in such patients probably occur much earlier in the natural history of this disease than is currently realized. Persistent nonsuppressible hypersecretion of PTH probably contributes to the bone disease of primary biliary cirrhosis. The low osteocalcin concentrations probably reflect diminished osteoblastic activity, which may also contribute to osteopenia in these patients.
Assuntos
Proteínas de Ligação ao Cálcio/sangue , Ergocalciferóis/uso terapêutico , Hiperparatireoidismo/etiologia , Cirrose Hepática Biliar/complicações , Adulto , Idoso , Calcifediol/sangue , Calcitriol/sangue , Cálcio/sangue , Cálcio/uso terapêutico , Feminino , Humanos , Hiperparatireoidismo/sangue , Cirrose Hepática Biliar/sangue , Cirrose Hepática Biliar/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Osteocalcina , Hormônio Paratireóideo/sangueRESUMO
The genes for type I interferon (IFN), which include 14 IFN-alpha genes, 1 IFN-beta gene, 1 IFN-omega gene, and a number of IFN-omega pseudogenes, are clustered on human chromosome 9. Among IFN-alpha genes, a number of variants have been reported. Three variants of IFN-alpha 7 (IFN-alpha 7a, IFN-alpha 7b, and IFN-alpha 7c) and IFN-alpha 14 (IFN-alpha 14a, IFN-alpha 14b, and IFN-alpha 14c) and two variants of IFN-alpha 21 (IFN-alpha 21a and IFN-alpha 21b) are identified. The variants differ from each other by base changes in the coding region and can be distinguished by selective restriction enzyme analysis and DNA sequencing. We have used polymerase chain reaction (PCR) with IFN species-specific oligonucleotide primers for amplification of IFN-alpha 7, IFN-alpha 14, and IFN-alpha 21 gene sequences. Genomic DNA obtained from over 28,000 normal healthy individuals were collected in six pools for PCR amplification. To identify the presence of variant sequences, the resulting PCR products of specific IFN-alpha genes were analyzed by restriction endonuclease digestion and DNA sequencing, with a limit of detection of minor components to 1% and 10%, respectively. The results show that only one variant form for each of IFN-alpha 7, IFN-alpha 14, and IFN-alpha 21, namely, IFN-alpha 7a, IFN-alpha 14c, and IFN-alpha 21b, is detectable in the genomic DNA of the population examined. Similar results were obtained from the analysis of a human myeloblastoid cell line, KG-1.
Assuntos
Cromossomos Humanos Par 9 , Variação Genética , Genoma Humano , Interferon-alfa/genética , Código Genético , Humanos , Dados de Sequência Molecular , Mutação , Reação em Cadeia da Polimerase , Mapeamento por Restrição , Análise de Sequência de DNARESUMO
Alpha interferons (IFN-alpha) are a class of cytokines with various activities that are used as therapeutic agents for treatment of cancer and viral and immune disorder diseases. At least 13 IFN-alpha genes and 1 IFN-alpha pseudogene have been identified, which are clustered on human chromosome 9. Among the known IFN-alpha species, a number of allelic variants have been reported. Two variants of IFN-alpha4 (IFN-alpha4a and IFN-alpha4b) are known, which differ from each other by changes in their coding regions at nucleotide positions 220 and 410 and can be distinguished by selective restriction enzyme analysis. We have developed oligonucleotide primers for specific amplification of IFN-alpha4 gene fragments using the polymerase chain reaction (PCR). Genomic DNA obtained from over 28,000 normal healthy individuals and six human cell lines were used in this study. The resulting PCR products were analyzed by restriction endonuclease digestion and DNA sequencing to identify the presence of variant sequences. The results show that the DNA sequences for both variants of IFN-alpha4 are found in the population in nearly equal proportion. Individuals with either homozygous (e.g., alpha4a/alpha4a or alpha4b/alpha4b) or heterozygous (i.e., alpha4a/alpha4b) IFN-alpha4 genes were detected. Among the cell lines, KG-1, EB-3, and HTB-10 cells contain the genes for IFN-alpha4a only, whereas U-937, Namalwa, and Daudi cells contain the genes for both IFN-alpha4a and IFN-alpha4b.
Assuntos
Antineoplásicos , Antivirais , Interferon-alfa/genética , Fragmentação do DNA , Amplificação de Genes , Variação Genética , Humanos , Mapeamento por RestriçãoRESUMO
Three variants of human interferon (IFN)-alpha 8a gene, that is, IFN-alpha 8b, and IFN-alpha 8c, have been reported previously. They differ from each other by changes in their coding region at nucleotide positions 359-360, 372, and 550. Human genomic DNA obtained from over 28,000 healthy blood donors and from 4 human cell lines was used in the polymerase chain reaction (PCR) designed for specific amplification of the IFN-alpha 8 gene fragments. The resulting PCR product was analyzed by (1) restriction endonuclease digestion, (2) DNA sequencing, and (3) allele-specific secondary PCR amplification. Only one sequence for IFN-alpha 8 was identified, and that was for IFN-alpha 8b. The sequences for IFN-alpha 8a and IFN-alpha 8c were not detected after PCR amplification either in the pooled leukocytes obtained from > 28,000 individuals or in cell lines tested. These data suggest that the naturally occurring variant or allele for IFN-alpha 8 in the population is IFN-alpha 8b. IFN-alpha 8a and IFN-alpha 8c variants were consistently below the level of detection of the assays and, if present at all in the population, are very rare.
Assuntos
Variação Genética , Genoma Humano , Interferon-alfa/genética , Alelos , Linhagem Celular , Fragmentação do DNA , Código Genético , Humanos , Reação em Cadeia da Polimerase , Valores de Referência , Mapeamento por RestriçãoRESUMO
Thirteen interferon (IFN)-alpha functional genes have been reported. Among these, a number of genes have allelic members (variants). In the case of IFN-alpha17, five variants, IFN-alpha17a, IFN-alpha17b, IFN-alpha17c, IFN-alpha17d, and IFN-alphaT, are known. The variants differ from each other by base changes in the coding region, leading to differences in amino acid sequences. We have developed oligonucleotide primers for amplification of IFN-alpha17 gene(s) using polymerase chain reaction (PCR). Genomic DNA, obtained from over 28,000 normal healthy individuals and from four cell lines, were used as templates in PCR to amplify the IFN-alpha17 gene sequences. The resulting PCR products were analyzed by restriction endonuclease digestion and DNA sequencing to identify the presence of variant sequences. The results show that a new variant of IFN-alpha17 is abundantly present (approximately 70%) along with another variant, possibly IFN-alpha17c (approximately 30%), in the genomic DNA of the population examined. This new variant, the protein product of which is identical to IFN-alpha17b, differs from the gene for IFN-alpha17b by a point mutation. We have named it IFN-alpha17b', which is the only variant found in U-937, KG-1, and EB-3 cell lines. Namalwa cells have IFN-alpha17b' and, possibly, IFN-alpha17c in equal proportions.
Assuntos
Variação Genética , Interferon-alfa/genética , Alelos , Sequência de Bases , Fragmentação do DNA , Código Genético , Humanos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Mapeamento por RestriçãoRESUMO
Variants of human leukocyte interferon alpha 2 (IFN-alpha 2a, alpha 2b, and alpha 2c) differ from each other by changes in their coding regions at nucleotide positions 137 and 170. As a result of these nucleotide variations, the DNA sequences of the three variants can be distinguished by selective restriction enzyme analysis. Human genomic DNA obtained from over 28,000 normal healthy individuals was used as templates in the polymerase chain reaction (PCR) to amplify the human IFN-alpha 2 gene sequence. The resulting PCR products were analyzed with restriction nucleases to identify the specific IFN-alpha 2 variant sequences present in the genomic DNA of the population examined. The results show that IFN-alpha 2b was detected as the predominant species and IFN-alpha 2c as a very minor species (< 0.1%). The IFN-alpha 2a gene was not detected in this population.
Assuntos
Variação Genética , Genoma Humano , Interferon Tipo I/genética , Leucócitos/fisiologia , Alelos , Sequência de Bases , DNA/genética , Humanos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Valores de Referência , Mapeamento por Restrição , Células Tumorais CultivadasRESUMO
The 90-min-uptake (37 degrees C) of 3H-methotrexate (3H-MTX) by uninduced HL60 cells was inhibited by 2,4-dinitrophenol, iodoacetate, ouabain, p-chloromercuriphenylsulphate and p-chloromercuribenzoate indicating its dependence on intracellular ATP, the Na+ and K+-activated ATPase of the cell membrane and sulphydryl groups on the cell surface. There was a marked reduction in the 90-min-uptake (37 degrees C) of 3H-MTX and 14C-methyltetrahydrofolate (14C-mTHF) when HL60 cells were induced to differentiate into neutrophil myelocytes and metamyelocytes by incubation with DMSO; a smaller reduction was seen when HL60 cells were induced to differentiate into mononuclear phagocytes by incubation with 1 alpha,25-dihydroxyvitamin D3 ([OH]2D3). Although it has been reported that the transport system mediating folate uptake has a higher Km value for mTHF and MTX in normal than in malignant cells, the Km values for these substrates were lower in blood-monocyte-derived macrophages than in uninduced HL60 cells or [OH]2D3-induced-macrophages. Values for the 90-min-uptake (37 degrees C) of 3H-MTX and 14C-mTHF in human blood-monocyte-derived macrophages were higher than the corresponding values in uninduced HL60 cells and [OH]2D3-induced macrophages.
Assuntos
Leucemia Mieloide Aguda/patologia , Macrófagos/metabolismo , Metotrexato/farmacocinética , Tetra-Hidrofolatos/farmacocinética , Transporte Biológico Ativo/efeitos dos fármacos , Calcitriol/farmacologia , Diferenciação Celular/efeitos dos fármacos , Depressão Química , Dimetil Sulfóxido/farmacologia , Humanos , Macrófagos/efeitos dos fármacos , Masculino , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , ATPase Trocadora de Sódio-Potássio/metabolismo , Células Tumorais Cultivadas/efeitos dos fármacos , Células Tumorais Cultivadas/metabolismo , Células Tumorais Cultivadas/patologiaRESUMO
Since histamine has recently been shown to play an important role in the pathogenesis of atherosclerosis in experimental nonketotic diabetes, and since leukocytes and platelets contain most of the histamine in blood, we have determined the levels of histamine in these cells from patients with peripheral vascular disease (PVD), insulin-dependent diabetes mellitus (IDDM) and non-insulin-dependent diabetes mellitus (NIDDM). The leukocyte and platelet histamine concentration in PVDs was significantly greater than that in controls, IDDMs and NIDDMs. Histamine content of leukocytes and platelets from IDDMs and NIDDMs did not differ from that in control subjects. The higher histamine content of leukocytes and platelets in PVD may lead to a greater release of this amine at sites of vascular endothelial damage. Increased histamine release may increase endothelial permeability and contribute to further vascular injury as observed in experimental models of diabetes and hypercholesterolemia.
Assuntos
Plaquetas/metabolismo , Histamina/sangue , Claudicação Intermitente/sangue , Leucócitos/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Permeabilidade Capilar , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 2/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Intraplatelet serotonin (5-HT), beta-thromboglobulin (beta-TG), and histamine content as well as platelet total thromboxane A2 (TXA2) synthesizing capacity were measured in 53 patients with chronic renal disease: nephrotic syndrome (n = 18); end-stage renal failure (ESRF; n = 13); continuous ambulatory peritoneal dialysis (CAPD; n = 9); hemodialysis (HD; n = 13). These indices of platelet function were correlated with plasma total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TG) concentrations. When compared with controls, intraplatelet 5-HT was significantly reduced in all patient groups studied and beta-TG was diminished in all patient groups except CAPD. Total platelet TXA2 synthesizing capacity was increased in ESRF and HD groups. Intraplatelet histamine content was not altered in any of the patient groups studied. There was a significant inverse correlation between intraplatelet 5-HT content on the one hand and plasma TC, LDL-C, and TG on the other. The depletion of intraplatelet 5-HT and beta-TG and the increase in total TXA2 synthesizing capacity are consistent with platelet activation in chronic renal disease. The correlation between these indices of platelet activation and TC, LDL-C, HDL-C, and TG suggests that changes in the concentrations of these lipids may contribute to the activation of platelets in these conditions.
Assuntos
Plaquetas/química , Nefropatias/sangue , Falência Renal Crônica/sangue , Síndrome Nefrótica/sangue , Adolescente , Adulto , Feminino , Histamina/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Diálise Peritoneal , Diálise Renal , Serotonina/sangue , Tromboxano A2/sangue , beta-Tromboglobulina/análiseRESUMO
Plasma histamine concentrations were measured using a commercially available monoclonal antibody radioimmunoassay in 38 patients with nephrotic syndrome, end stage renal failure, those receiving haemodialysis, and those receiving continuous ambulatory peritoneal dialysis to determine whether histamine may mediate damage to glomerular capillaries and arterial endothelium. Plasma histamine concentrations were significantly increased in all four patient groups when compared with those of controls and were the highest in two patients with pruritus. Raised plasma histamine concentrations in such patients are consistent with the hypothesis that histamine may contribute to the damage to glomerular capillaries and to arterial endothelium. These effects may be relevant to the pathogenesis of glomerular disease and atherosclerosis. Histamine may also contribute to the pathogenesis of pruritus in patients with chronic renal failure.
Assuntos
Histamina/sangue , Falência Renal Crônica/sangue , Síndrome Nefrótica/sangue , Adolescente , Adulto , Idoso , Feminino , Humanos , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Síndrome Nefrótica/terapia , Diálise Peritoneal Ambulatorial Contínua , Prurido/sangue , Prurido/complicações , Radioimunoensaio , Diálise Renal , Doenças Vasculares/sangue , Doenças Vasculares/complicaçõesRESUMO
In view of the observations that (1) plasma histamine concentrations are significantly higher in diabetic patients and diabetic rats than those in controls, and (2) tissue concentrations of histamine are elevated in rats with experimental diabetes, we have investigated histamine synthesis, as reflected by histidine decarboxylase (HDC) activity, and histamine catabolism, as reflected by histaminase activity, in various tissues of the diabetic rat. Rats with streptozotocin-induced diabetes mellitus (DM) showed an increase in histamine synthesis in various tissues; this was most marked in the aorta and to a lesser, but significant, extent in the kidneys, lungs, and heart, but not in the brain, stomach, or skin. Tissue content of histamine was significantly increased in all tissues except the stomach and skin. We conclude that tissue histamine synthesis is significantly increased in diabetic animals and that this increase is most marked in the aorta. The elevation in HDC activity in these tissues probably accounts for the increase in tissue and plasma concentrations of histamine in diabetic animals, since there is no change in histamine catabolism. This increase in histamine synthesis and release may contribute to the pathogenesis of endothelial damage in diabetic microangiopathy and macroangiopathy.
Assuntos
Diabetes Mellitus Experimental/metabolismo , Histamina/metabolismo , Animais , Aorta/metabolismo , Encéfalo/metabolismo , Mucosa Gástrica/metabolismo , Histamina/biossíntese , Histidina Descarboxilase/metabolismo , Rim/metabolismo , Pulmão/metabolismo , Masculino , Músculo Liso Vascular/metabolismo , Miocárdio/metabolismo , Especificidade de Órgãos , Ratos , Ratos Endogâmicos , Valores de Referência , Pele/metabolismoRESUMO
Previous work has shown that plasma and tissue concentrations of histamine are elevated in rats with experimental diabetes mellitus and that leucocytes and platelets from patients with peripheral vascular disease have a higher histamine content than those from controls. In the present study, we have measured: (a) plasma histamine concentrations; (b) leucocyte and platelet histidine decarboxylase (the enzyme responsible for the biosynthesis of histamine) in patients with diabetes mellitus (Types I and II) and peripheral vascular disease; and (c) platelet and leucocyte histamine content. Plasma histamine concentration was significantly higher in patients with diabetes and peripheral vascular disease respectively than that in age-matched controls. Leucocyte histidine decarboxylase activity in diabetic and peripheral vascular disease patients was similar to that in controls, while platelets had no histidine decarboxylase activity. The leucocyte and platelet content of histamine were greater in patients with peripheral vascular disease than those in controls, but they were not altered in diabetic patients. There was no correlation between plasma histamine concentration, leucocyte and platelet histamine content, and histidine decarboxylase activity. We conclude that plasma histamine is elevated in diabetics and in patients with peripheral vascular disease and that platelet and leucocyte histamine content is increased in the latter. This increase in platelet and leucocyte histamine content is not due to an increase in histidine decarboxylase activity of these cells. The increase in plasma and cellular histamine content may contribute to the pathogenesis of increased endothelial permeability in diabetes and to the pathogenesis of intimal damage in atherosclerosis.